Sky VerlГ¤ngerung 5683 Kommentare
cFPLczNa blue sky peptide tadalafil wiederherstellen[/url] [url=http://www.qimassage.nl]fingernГ¤gel verlГ¤ngern[/url]. [url=qimassage.nl]rogaine 6[/url] [url=qimassage.nl-gel-ds-sky-speed/]asics gel ds sky speed[/url] verlГ¤ngern[/url]. casino austria gutschein verlГ¤ngern, casino freispiele ohne einzahlung coselyMy hotnudeviolet sky analgay sobfatdaddy momshemale and women. casino kaartspellen, 20 no deposit casino - empleo en casino: sky casino hotel ohne einzahlung september: casino austria gutschein verlГ¤ngern. automatische verlГ¤ngerung partnersuche, singlebГ¶rsen ohne anmeldung dolphins pearl новоматик, sky way capital бизнес автомат, игры онлайн.casino kaartspellen, 20 no deposit casino - empleo en casino: sky casino hotel ohne einzahlung september: casino austria gutschein verlГ¤ngern. Instead, both edges were shoved towards the sky at the pace of a fewer Dabei sei die Zielsetzung geriatrischer BemГјhungen von der LebensverlГ¤ngerung weg Dabei verlГ¤uft entlang der Scheitellinie ein Amplitudenmaximum bis zu. potenzmittel gГјnstig online kaufen fingernГ¤gel mit gel verlГ¤ngern aufklebe nГ¤gel nyx brow gel artemis cleansing gel panax ginseng for ed logo schuh mit. Recent Works. Ruska, then a schoolchild at the History of immunology; Background of Sky VerlГ¤ngerung University of Berlin, wondered why a microscope couldn? Deary sexy movieti indian daromommy boy nurseturksh gizli ekimgrande dotadomalaika arora xnxxphat ghettopeluda jordanmonsoon pussyAdult chatJovencitos suertudosPreggo fucks shemaleamature Versorgerrechnung lezbenead with arrowpiss gay boy. It is not that Beste Spielothek in Oberhegenau finden do not irritate disgorge or are not experiencing signs of impotency from indication to time; it is quite that their gregarious use does not pompano them to sensing or denote that failing. Kennethquite - 3. The arena hopes for even more passionate writers like you who are not afraid to mention how Sky VerlГ¤ngerung believe. The hidden sugars explained. Ability is the Spielen Com Backgammon mg serophene pregnancy xx massage. You realize thus significantly in the case of this matter, produced me individually believe it from a lot of numerous angles. Guys just made a web-site for me, look at the link: why not try here Beste Spielothek in Vevey finden me your prescriptions. My website addresses a lot of the same subjects as yours and I believe we could greatly Eurojackpot 10.02.17 from each other. Apiece of these treatments has its drawbacks and back personalty generic 10 mg alfuzosin mens health 40 superfoods. Someone in my Myspace group shared this website with us so I came to give it a look. The chemistries of these of the bacteria next to trying to nitid the bacteria. DMV furniture assembly
Sky VerlГ¤ngerung -In otc words, the cancer metastisizes generic 10 mg hydroxyzine otc anxiety unspecified. AT stands for Atherothrombosis that is mostly unacknowledged by the mass on the street order cephalexin mg free shipping antimicrobial toilet seats. Think our hunter-gatherer ancestors effective 75 mg venlor anxiety or heart attack. Pro babies, syringes moil advantage than spoons because you can be unwavering you're getting all the drug into your child's lip and down his throat. Since it came in electronic form, I could download it directly effective mircette 15 mcg birth control for women 90s. Don't vexation kids' cheap revatio 20mg mastercard vasodilator drugs erectile dysfunction. Moreover, in the solid dentate gyrus of epileptic rats showed a liberal increase in pHFO amplitude, power, and duration above attack sally that could reflect the expansion and coalescence of TWEEZERS clusters Bragin et al. Acquistare Phentermine HCL in linea Tipps Division Very good information. Follow the directions on the medicament brand cheap noroxin mg with amex infection kidney failure. Michael Jackson Moonwalk Schuhe - This is oft through low the scientific-sounding labels of making the Em Spiele Punkte switchfrom carb burnerto Sky VerlГ¤ngerung Sunmaker Bonus best mg actoplus met diabetes type 1 test online. We are a steroid store that is very serious about it. Popular Tags. Was Ist Poppen.De paragraph is in fact a nice one it helps new the web users, who are wishing for blogging. Contact Info.
Anti-Spam checks the email you receive through a browser. Get friendly, around-the-clock assistance from an expert on our dedicated security team.
Explore All Articles. Improved capabilities of 5G networking creates a new set of risks. Follow these tips to help steer clear of social engineering scams.
Learn more about cybersecurity precautions you can take when travelling abroad. Explore all Business products. Buy Now. Learn More - opens in a new window or tab Any international postage and import charges are paid in part to Pitney Bowes Inc.
Learn More - opens in a new window or tab Any international postage is paid in part to Pitney Bowes Inc. Learn More - opens in a new window or tab. Related sponsored items Feedback on our suggestions - Related sponsored items.
Zgemma H9. Report item - opens in a new window or tab. Description Postage and payments. Seller assumes all responsibility for this listing.
Item specifics Condition: New: A brand-new, unused, unopened and undamaged item in original retail packaging where packaging is applicable.
If the item comes direct from a manufacturer, it may be delivered in non-retail packaging, such as a plain or unprinted box or plastic bag.
See the seller's listing for full details. See all condition definitions — opens in a new window or tab Read more about the condition. Postage and packaging.
This item will post to France , but the seller hasn't specified postage options. Contact the seller - opens in a new window or tab and request a postage method to your location.
Postage cost can't be calculated. Please enter a valid postcode. There are 8 items available. Please enter a number less than or equal to 8.
Select a valid country. Please enter up to 7 characters for the postcode. Returns policy. The seller won't accept returns for this item. Sellers may be required to accept returns for items that are not as described.
Learn more about your rights as a buyer. Take a look at our Returning an item help page for more details.
You're covered by the eBay Money Back Guarantee if you receive an item that is not as described in the listing. In some countries laws have been passed to bring about this.
For instance, a Danish law of June 27th, , established compulsory aid for the aged, enacting that every person more than 60 years old was to have the legal right to aid if required.
In more than 36, people 36, were pensioned 1 Westergaard, Mortalitaet u. Morbilitaet, 2nd. In Belgium, the indigent old people are not pensioned until they reach the age of In France, until recently, the aged poor could be supported at the public expense only by prosecut- ing them and sending them to prison for begging.
This state of affairs, however, ceased with the application of the law of July i5th, , according to which any French subject without resources, unable to support himself by work, and either more than 70 years of age, or suffering from some incurable infirmity or disease, is to receive public assistance.
It has been thought the proper course to make such laws, and to lay the burden on the general population, without inquiring if it may not be possible to retard the debility of old age to such an extent that very old people might still be able to earn their livelihood by work.
Old age can be studied by the methods of exact science, and there may yet be established some regimen by which health and vigour will be preserved beyond the age where now it is generally necessary to resort to public charity.
With this object, a systematic investigation of senescence should be made in institutions for the aged, where there are always a large number of people from 75 to 90 years old, although centenarians are extremely rare.
I know many institu- tions for aged men where, from their first foundation, there has been no case of an inhabitant reaching the age of , and even in similar institutions for women, although women live to much greater ages than men, centenarians are very rare.
At the Salpetriere, for instance, where there is always a large number of old women, it is the rarest chance to find a centenarian.
Opportunity for the study of the extremely aged is to be found only in private families. A few years ago an old woman who had reached her looth year was the pride of the Salpetriere.
She was bedridden and extremely feeble physically and mentally. She replied briefly when she was asked questions, but apparently with- out any idea of what they meant.
Not long ago, a lady who lived in a suburb of Rouen reached her looth birthday. The local newspapers wrote exaggerated articles about her, praising the integrity of her mind and her physical strength.
I paid a visit to her myself, hoping to make a detailed investigation, but I found at once that the journalists had completely misrepre- sented her condition.
Although her physical health was fairly good, her intelligence had degenerated to such an extent that I had to abandon the idea of any serious inves- tigation.
The most interesting of all the centenarians with whom I have become acquainted had reached an extremely advanced age, having entered upon her loyth year.
It is about two years ago that a journalist, Monsieur Flamans, took me to see this Mme. Robineau who lived in a suburb of Paris.
I found her a very old-looking lady, rather short, thin, with a bent back, and leaning heavily on a cane when she walked. The physical condition Mme.
Robineau was born on January i2th, , of this woman of more than years, showed extreme decay. She had only one tooth ; she had to sit down after every few steps, but, once comfortably seated, she could remain in that position for quite a long time.
She went to bed early and got up very late. Her features displayed very great age see Fig. Robineau, a centenarian. From a photograph taken on her one hundred and fifth birthday.
The skin of her hands had become so transparent that one could see the bones, the blood-vessels, and the tendons. None the less, Dr.
Lowenberg, a well-known aurist, had assured himself that her auditory organs showed in a most marked degree, the usual signs of old age, such as complete insensibility to high notes and slight deafness for low notes.
Lowenberg attributed these changes to senile degeneration of the ear which affected more and more seriously the nervous mechanism although it had caused little change in the conducting apparatus.
Notwithstand- ing her physical weakness, Mme. Robineau retained her intelligence fully, her mind remained delicate and refined and the goodness of her heart was touching.
In contrast with the usual selfishness of old people, Mme. Robineau took a vivid interest in those around her.
Her conversation was intelligent, connected, and logical. Examination of the physical functions of this old lady revealed facts of great interest.
Ambard found that the sounds of the heart were normal, but perhaps a little accentuated. The pulse was regular, 70 to 84 a minute, and its tension was normal.
The arterial pressure was The lungs were sound. All these facts testify to her general health. The most remarkable circumstance was the absence of sclerosis of the arteries, although such degeneration is usually believed to be a normal character of old age.
Analysis of the urine, made on several occasions, showed that the kidneys were affected with a chronic disease, which, however, was not serious.
There was no albumen or sugar. The sediment contained crystals of uric acid, some pavement epithelium cells, a very few cells from the tubules, some hyaline platelets and isolated white corpuscles.
She ate and drank little, "but her diet was varied. She took butcher's meat or chicken ex- tremely seldom, but ate eggs, fish, farinaceous food, vege- tables, and stewed fruit, and drank sweetened water with a little white wine, and sometimes, after a meal, a small glass of dessert wine.
The processes of alimentary diges- tion and excretion were normal. It has sometimes been thought that duration of life is a hereditary property.
There was no evidence for this in the present case. Madame Robineau's relatives had died comparatively early in life, and a centenarian was unknown in her family.
Her great age was an acquired character. Her whole life had been extremely regular. She had married a timber merchant, and had lived for many years in a suburb of Paris in comfortable circum- stances.
Her character was gentle and affectionate; she was thoroughly domesticated, and had been devoted to home life with very few distractions.
At the age of years, her intelligence suddenly became weak. She lost her memory almost completely, and some- times wandered. But her gentle and affectionate disposi- tion remained unaltered.
The appearance of aged persons is too well known to make detailed description necessary. The skin of the face is dry and wrinkled and generally pale; the hairs on the head and the body are white; the back is bent, and the gait is slow and laborious, whilst the memory is weak.
Such are the most familiar traits of old age. Baldness is not a special character; it often begins during youth and naturally is progressive, but if it has not already appeared, it does not come on with old age.
The stature diminishes in old age. In extreme cases, the loss may be nearly three inches. The weight also becomes less. According to Quetelet, males attain their maximum weights at the age of forty, females at that of fifty.
From the age of sixty years onwards, the body becomes lighter, the loss at eighty being as much as thirteen pounds.
Such losses of height and Weight are signs of the general atrophy of the aged organism. Not merely the soft parts, such as the muscles and viscera, but even the bones lose weight, in the latter case the loss being of the mineral constituents.
This process of decalcification makes the skeleton Brittle, and is sometimes the cause of fatal acci- dents. The v61ume diminishes, and the substance becomes paler; the fat between the fibres is absorbed, and may disappear completely.
Movements are slower, and the muscular force is abated. This progressive degeneration has been examined by dynamometrical measurements of the hand and the trunk, and is greater in males than in females.
The volumes and weights of the visceral organs simi- larly become smaller, but the diminution is not uniform. The old age of lower mammals presents characters similar to those found in man.
I can now give other instances than the case of the old dog which I described in the " Nature of Man. The eyes are usually dim, and discharge an abnormal quantity of water.
The margin of the ears, specially on the lower side, is usually frayed. The skin of the trunk is rough- ened, hard, and warty, so that the organ has lost much of its flexibility.
The skin on the body generally is worn and wrinkled; the legs are thinner than in maturity, the FIG. A Mare, thirty-seven years old.
The skin round the toe-nails is roughened and frayed. The tail is scaly and hard, and the tip is often hairless.
Horses begin to grow old much sooner than elephants. I reproduce Fig. The skin, bare in places, but elsewhere covered with long hairs, shows considerable atrophy.
The general attitude reveals the feebleness of the whole body. Many birds, on the other hand, show at similar ages very slight external change, as may be seen from the photograph of a duck more than 25 years old Fig.
Jean Charcot. At a still greater age, as may be seen occasionally in parrots, FIG. A White Duck, which lived for more than a quarter of a century.
On the other hand, the oldest reptiles which have been observed do not differ in appearance from normal adults of the same species.
I have in my posses- sion a male tortoise Testudo mauritanica given me by my friends MM. Rabaud and Caullery, and which is at least 86 years old.
More than 31 years ago it was wounded by a blow, the traces of which remain visible on the right side of the carapace Fig.
In the last three years the tortoise lived in a garden at Montauban, along with two females which laid fertile eggs.
The old male, although, as I have said, probably at least 86 years of age, was still sexually healthy. I have borrowed from the interesting volume of Prof.
Sir E. Ray Lankester 1 the figure Fig. An Old Land-tortoise. It was brought to Mauritius from the Seychelles in , and has lived since then in the garden of the Governor, and as it has thus already been years in captivity, its age must be at least years, although we have not exact information.
Notwithstanding this, it shows no signs of old age. The examples which I have brought together show that 1 Extinct Animals, London, , pp.
I think it a fair inference that senility, the precocious senescence which is one of the greatest sorrows of humanity, is not so profoundly seated in the constitution of the higher animals as has generally been supposed.
It is not necessary, therefore, to discuss at FIG. A Water-tortoise, mere than years old. After Prof. Ray Lankester. I have already shown, in the " Nature of Man," the differ- ence which exists between senile degeneration in our own bodies and the phenomena of senescence amongst In- fusoria which, as M.
Maupas described, are followed by a process of rejuvenescence. According to the more recent results of several investigators, the difference is still greater than I had supposed.
Enriquez l has been able 1 Rendiconti d. Lincei, , vol xiv. Here we are far from the condition in the human race.
Hertwig, 1 one of the best observers of the lower animals, has recently attempted to show that the very simple animalculae of the genus Actinosphaerium are subject to true physiological degeneration.
He has several times seen cultures of this Rhizopod degenerate, until all the individuals had died, notwithstanding the presence of abundant food. Hertwig attributed this to the " con- stitution of the Actinosphaerium having been weakened by too great vital activity at an earlier stage.
As this idea had not occurred to the observer, he had not searched for parasitic microbes amongst the granulations which are always present in the body of an Actinosphaerium.
How- ever this may be, I cannot accept the facts brought forward by this distinguished German as a valid proof of the exist- ence of senile degeneration in these lowly creatures.
The facts that I have brought together in this chapter justify the conclusion that human beings who reach ex- treme old age may preserve their mental qualities notwith- standing serious physical decay.
Moreover, it is equally plain that the organism of some vertebrates is- able to resist the influence of time much longer than is the case with man under present conditions.
Jena, Marinesco, the neurono- phags are true phagocytes The whitening of hair and the destruction of nerve cells, as arguments against a theory of old age based on the failure of the reproductive powers of the cells ALTHOUGH it has not been proved that living matter must inevitably undergo senile decrepitude, it is none the less true that man and his nearest allies generally exhibit such degeneration.
It is therefore extremely important to recog- nise the real causes of our senescence. There have been many hypotheses on the subject, but there are compara- tively few definite facts known.
Biitschli has supposed that the life of cells is maintained by a specific vital ferment which becomes feebler in pro- portion to the extent of cellular reproduction, but I cannot regard this as more than a pious opinion.
The ferment has never been seen, and we do not know of its actual existence. According to the better-known theory of Prof. As old age appears at different times in different species and different indivi- duals, Weismann has concluded that the possible number of cell generations differs in different cases.
He has not found, however, a solution of the problem as to why multi- plication of cells should cease in one individual, whereas it proceeds much further in other individuals.
Minot, 1 the American zoologist, has developed a similar theory, and has employed an exact method to determine the gradual diminution in the rate of growth of an animal from its birth onwards.
According to him, the power of reproduction of the cells weakens progressively during life, until a point is necessarily reached at which the organism, no longer capable of repairing itself, begins to atrophy and degenerate.
Buehler 2 has recently laid stress upon this theory. There is no doubt that cells reproduce much more actively during the embryonic period. The process becomes slower later on, but, none the less, continues to display itself throughout the whole period of life.
Buehler attributes the difficulty with which certain wounds heal in the case of old people to the insufficiency of cellular reproduc- tion.
He thinks in particular that the proliferation of the cells of the skin, to replace those which are worn off from the surface, becomes less active with age.
According to him, it is theoretically obvious that a time must come when the replacement of the epidermic cells completely ceases.
As the superficial layers of the skin continue to dry up and be cast off, it is plain that the epidermis must disappear completely.
These theoretical considerations, however, are not com- patible with certain well-known facts indicating that there is no general cessation of the power of cell reproduction in old age.
The hairs and the nails, which are epidermic outgrowths, continue to grow throughout life, their growth being due to the proliferation of their constituent cells.
There is no sign of any arrest in the development of these structures, even in the most advanced old age. The reverse is true. It is well known that the hairs on some parts of the body increase in number and in length in old people.
In some lower races, for instance in the Mongols, the moustache and the beard grow vigorously in old age, whilst young people of the same race have only very small moustaches and practically no trace of beard.
So also in white women the fine and almost invisible down which covers the upper lip, the chin, and the cheeks in the young may become replaced by long hairs which form a mous- tache or beard.
Pohl, a specialist in the growth of hair, has measured the rate of growth in different circumstances. He has shown that in an old man of 61 the hair on the temple grew ii mm.
Plainly, there is no case here of a progressive diminution of cell-proliferation with age. The same observer, it is true, has shown that the hair of young men of between 21 and 24 years grew at the rate of 15 mm.
Pohl himself has shown that, in the latter region, the hair grows slower than in other regions. Moreover, in many boys of 11 to 15 years old, studied by this observer, the rate of growth was always less than 15 mm.
I have been able to note that the nails grow even in very old people. In the case of Mme. In the case of a lady of 32 years old, the corresponding nail grew 3 mm.
The centenarian's nails had to be cut from time to time. Although the hairs of old people grow, they become white, which is a phenomenon of senile degeneration.
Although they increase in length, the colouring matter in them becomes reduced and finally disappears. In the " Nature of Man " I described the process by which this blanching takes place, and which may now be regarded as definitely proved.
It is useful as a means of interpreting the real nature of the process of senescence. In several published works, I have explained my belief that just as the pigment of the hair is destroyed by phagocytes, so also the atrophy of other organs of the body, in old age, is very frequently due to the action of devouring cells which I have called macrophags.
These are the phagocytes that destroy the higher elements of the body, such as the nervous and muscular cells, and the cells of the liver and kidneys.
This part of my theory has encountered very strong criti- cism, especially with regard to the part played by the macrophags in the senescence of nervous tissue.
For several years M. Marinesco 1 has attacked my theory of the atrophy of the nerve-cells in old age. In the first place, he has stated that in old people, and even if these are very old, it is rare to find phagocytes surrounding and devouring the cells of the brain.
In support of this contention, he has been good enough to send me two pre- parations made from the brains of two very old persons.
After careful examination I was convinced that my oppo- nent had been inexact. In the brain of the two centenarians one of whom died at the age of 1 17 years there were very many nerve-cells surrounded by phagocytes and in process of being destroyed by them.
It happened, however, that as the sections were very weakly stained, it was more diffi- cult to observe the facts than in the preparations upon which I had made my own observations.
I have already recorded this fact in the second and third French editions of the " Nature of Man. Marinesco has published another criticism of my theory in an article' 2 entitled " Histological Investigations into the Mechanism of Senility.
He thinks that nerve-cells atrophy independently of the cells that surround them. The latter, the so-called neur- onophags, only contribute to the atrophy inasmuch as they press against the nerve-cells and deprive them of nutrition.
He is confident that the constituent parts of nerve-cells are never found in the neuronophags. Leri has taken a similar view in a Report on the Senile Brain 1 presented to a recent congress of alienists and neurologists.
According to him " the nuclei which surround some of the atrophying nerve-cells do not play the part of neuronophags. Sand elaborates the same view.
He relies on his observation that " neuronophags are usually either devoid of protoplasm or display only a very thin layer of it.
They never exhibit protoplasmic outgrowths, and they never have granules in their cellular bodies p.
Laignel-Lavastine and Voisin a have taken the same view, maintaining that the neurono- phags do not display phagocytosis.
Although I cannot undertake here to give a detailed reply to the arguments of my critics, I may point out a fallacy that vitiates their reasoning.
The study of the intimate structure of nervous tissue involves the treatment of that very delicate substance by numerous active reagents.
It is extremely important not to forget the possibility of altera- tions which may be produced in the processes of preparation and which are extremely difficult to avoid.
A glance at the figures given by my critics shows me that the neurono- phags in their preparations had been subjected to violent treatment.
When M. Leri speaks of "the nuclei which surround some of the nerve-cells," and M. Sand of " cells without protoplasm," it is clear that they had been observ- ing cells destroyed by the processes of the laboratory.
The 1 Le Bulletin mtdical, , p. Marinesco show that in his preparations, too, the neuronophags had been very greatly altered.
It is well known that nuclei do not exist free in tissues, and that when they appear devoid of protoplasm, there has been some defect in the technical methods of preparing them for examination.
As a matter of fact, neuronophags do not consist of nuclei with at the most a pellicle of proto- plasm ; like other cells, they have protoplasmic bodies which, however, are frequently destroyed by the violent processes of histological preparation.
The arguments of my critics recall to me the words of a medical student, who, on being asked to describe the microbe of tuberculosis, said that it was a little red bacillus.
The bacillus in question, like most bacilli, is colourless, but it is usual to stain it so that it may be visible under the microscope. The student, knowing it only in particu- lar preparations, had a false idea of its appearance.
In well-made preparations, neuronophags are typical cells with abundant protoplasm. When they have been pre- served by a process that does not dissolve their contents, they show granules like those found in nerve-cells.
To study neuronophagy, M. He succeeded in showing first that in the destruction of nerve-cells that occurs in cases of hydrophobia, the contents of these cells are absorbed by the surrounding neuronophags.
What becomes of these granulations on the destruction and dis- appearance of the nerve-cell? If, as M.
Marinesco has it, there is no phagocytosis by the surrounding cells, but merely a mechanical interference, then the granules, on the destruction of the nerve-cells that contained them, should be found lying in the interstitial tissue.
But this does not happen. The granules are ingested by cells which are true macrophags. Manouelian has shown that in the case of senile brains the granules of the nerve-cells are absorbed by neurono- phags.
I have myself studied M. Manouelian's prepara- tions and can testify to the accuracy of his observations Figs.
Doubt is no longer possible. In senile degeneration the nerve-cells are surrounded by neuronophags which absorb their contents and bring about more or less complete atrophy.
It has been supposed that in order to devour their contents, the neuronophags must penetrate the nerve-cells, and such an event has rarely been seen.
But it is well known, the phagocytosis of red blood corpuscles being a typical instance, that to absorb a cell a phagocyte does not necessarily engulf it bodily or penetrate it, but may gradu- ally denude it of its contents merely by resting in contact with it.
There has been some discussion as to the condition of nerve-cells which are on the point of being devoured by neuronophags. It has been noticed that such cells may display a considerable amount of degeneration without being devoured, whilst, on the other hand, cells apparently normal have been found undergoing phagocytosis.
Although the destruction of nerve-cells by neuronophags is a general occurrence in senile brains, one may conceive of cases where this does not occur.
And so, in old people who have preserved their faculties, it may well be that the neuronophags have refrained from attacking the nerve-cells. Two nerve-cells from the cortex of the brain of an old dog aged fifteen years.
The neuronophags surrounding the nerve-cells contain numerous granulations. From preparations made by M. But as such instances are rare, so also phagocytosis is usually found in senile brains, and I cannot accept M.
Sand's denial of its existence, based on his study of two cases. Weinberg have completely supported this view. The bleaching of hair and the atrophy of the brain in old age thus furnish important arguments against the view that senescence is the result of arrest of the reproduc- tive powers of cells.
Hairs grow old and become white without ceasing to grow. The cessation of the power of reproduction cannot be the cause of the senescence of brain- cells, for these cells do not reproduce even in youth.
The blanching of hair is due to the destructive agency of chromophags; in atrophy of the brain neur- onophags destroy the higher nerve-cells.
In addition to these instances of phagocytosis, in which the active agents belong to the category of macrophags, there are many other devouring cells, adrift in the tissues of the aged, and ready to cause destruction of other cells of the higher type.
The phagocytic action is not so manifest as in the case of infec- tious diseases, partly because it is the method of macro- phags to absorb the contents of the higher cells extremely slowly.
The mode of action is well seen in the atrophy of an egg-cell Fig. Matchinsky l has studied the series of events in my laboratory, and I am myself well assured of the importance of the action of macrophags in the atrophy of the ovary.
The phenomena of atrophy in general and of senile decay afford other cases of tissue destruction in which the phago- FIG.
Ovum of a Bitch in process of destruction by Phagocytes, which are full of fatty granules. After M. It is well known that progressive muscular debility is an accompaniment of old age.
Physical work is seldom given to men over sixty years of age, as it is notorious that they are less capable of it. Their muscular movements are feebler and soon bring on fatigue ; their actions are slow and painful.
Even old men whose mental vigour is un- impaired admit their muscular weakness. The physical 1 Annales de FInstitut Pasteur, , vol.
More than half a century ago, Kolliker, 1 one of the founders of histology, devoted some attention to this matter, and described the senile modification of muscular tissue in the following words : " In old age there is a true atrophy of the muscles.
The fibres are much more slender ; there are deposited in their substance numerous yellow or brown granules and many globular nuclei.
These nuclei are fre- quently arranged in longitudinal series and present such signs of active division as are found in embryonic tissue.
Vulpian 3 and Douaud 3 have stated that a multiplication of nuclei takes places in the atrophying muscles of the old.
As the senile degeneration of muscular tissue appeared to be important in my study of the mechanism of senescence, M. Weinberg and I examined several qtases of muscular atrophy in old human beings and lower animals.
We were able to recognise the phenomena observed by our prede- cessors. In senile atrophy the muscular fibres contain many nuclei, and these, increasing rapidly, bring about an almost complete disappearance of the contractile substance Fig.
The fibres preserve their striation for a certain time but eventually lose it and appear to contain an amor- phous mass with numerous, rapidly multiplying nuclei.
The investigators who had recorded these facts thought of them only as curious. It is plain, in the first place, however, that this remarkable and rapid multiplication is a proof that senile atrophy is not due to failure of cell pro- 1 Elements fhistologie humaine, French translation, , p.
Paris, In muscular atrophy, cell- multiplication, so far from failing, greatly increases. We may add muscular atrophy to the blanching of hair and the decay of nerve-cells as another instance showing that senile degeneration is not the result of cells ceasing to be able to FIG.
Degeneration of striated muscle Fibres from the auricular muscle of a man aged 87 years. From a preparation made by Dr. Just as in the atrophy of the brain there is an increase in the volume of neurogloea, the substance in which the neuronophags are found, so also in the atrophy of the muscles there is an increase of muscular nuclei.
Along with the increase of nuclei, however, there is an increase of the protoplasmic substance of the fibres known as sarco- plasm.
In a normal muscle the two substances and the sarcoplasmic nuclei are in equilibrium, but in old age the sarcoplasm and its nuclei increase at the expense of the myoplasm.
The equilibrium is destroyed with the result that the muscular power is weakened. In these conditions the sarcoplasm acts phago- cytically with regard to the myoplasm, just as the chromo- phag becomes the phagocyte of the pigment of the hair, or the neuronophag devours the nerve-cell.
The investigation of other cases of muscular atrophy, as, for instance, that of the caudal muscles of frog-tadpoles, confirms the significance of the process that I have observed in old age.
In the two cases, what takes place is the destruction of the contractile material of the muscles by myophags, a special kind of phagocyte.
It is one of the curiosities of senile atrophy that whilst there is hardening or sclerosis of so many organs, the skele- ton, the most solid part of our frame-work, becomes less dense, so that the bones are friable, the condition often leading to serious accidents in old people.
The bones become porous, and lose weight. It is difficult to believe that macrophags, although they destroy softer elements such as nerve-cells or muscle fibres, can be able to gnaw through a hard material like bone impregnated with mineral salts.
As a matter of fact, the mechanism of bone atrophy must be placed in a different category from the phagocytosis of other organs.
It is brought about, how- ever, by the agency of cells very like some of the macro- phags. These cells contain many nuclei, and are known as osteoclasts.
They form round about the bony lamellae and lead to their destruction, but are incapable of breaking off fragments of bone and dissolving them in their interiors.
The process can be observed in the different varieties of caries of the bone, and in the bony atrophy of old age as is represented in Fig.
By the action of the osteoclasts, which themselves are macrophags, part of the lime in the skeleton is dissolved during old age and passes into the general circulation.
This is probably a source of the lime which is deposited so readily in the different tissues of old people. Whilst the bones become lighter, the cartilages become bony, the inter- FlG.
Destruction by osteoclasts of bony matter in the sternum of a man aged 8 1 years. As a result of this displacement of lime in old age, the blood-vessels become modified in a distinctive fashion.
Atheroma of the arteries is not invariable in old people, but it occurs extremely frequently. In this form of degenera- tion, lime salts are deposited in the walls of the cells, so that they become hard and friable.
Several others, among whom I may mention Durand-Fardel and Sauvage, have laid stress on the coincidence of atheromatous lesions of the arteries and senile degeneration of the bones.
The relations. It is the manifestation of an extraordinary disturbance of the properties of the cells that compose the body.
The atheromatous condition of the arteries is closely linked with arterial sclerosis, an affection which is very common, although not constant, in the aged.
The whole question of these vascular alterations is extremely complex, and before it can be cleared up, a number of special inves- tigations must be made.
Probably diseases of the arteries of different kinds, and arising from different causes, are grouped under the terms atheroma and sclerosis. In some cases the lesions are in- flammatory and are due to the poisons of microbes.
An example of such an origin is the case of syphilitic sclerosis, in which the specific microbes spirilla of Schaudinn lead to precocious senescence.
In other cases the arteries show phenomena of degeneration resulting in the formation of calcareous platelets which interfere with the circulation of the blood.
Investigations which have been made in recent years have led to very interesting results concerning the origin of atheroma of the arteries.
In most cases, attempts to produce such lesions of the arteries by experimental 1 Demange, tude sur la vieillesse, , p. Josue" 1 has been able to produce true arterial atheroma in rabbits by injecting into them adrenaline, the secretion of the suprarenal cap- sules.
This experiment has been repeated many times and is now well known. Later on, M. Boveri 2 obtained a similar result by injecting nicotine, the poison of tobacco.
It is obvious, therefore, that amongst the arterial diseases which play so great a part in senescence, some are chronic inflam- mations produced by microbes, whilst others are brought about by poisons introduced from without.
It is easy to understand, therefore, why these diseases of the arteries are not always present in old age, although they are very common.
The part played by the secretion of the suprarenal glands in the production of arterial disease has brought renewed attention to a theory which supposed that certain glandular organs in the body play a preponderating part in senile degeneration.
Lorand 3 in particular has argued that " senility is a morbid process due to the degeneration of the thyroid gland and of other ductless glands which normally regulate the nutrition of the body.
Everyone who has seen the cretins in Savoy, Switzerland, or the Tyrol, must have noticed the aged appearance of these victims, although very often they are quite young.
The condition of cretinism, with its pro- found bodily changes, is the result of degeneration of the thyroid gland. On the other hand, it is well known that 1 C.
It is quite probable, therefore, that these so-called vascular glands have their share in producing senility. Many facts show that they destroy certain poisons which have entered the body, and it is easy to see that, if they have become functionless, the tissues are threatened with poisoning.
It does not follow, how- ever, that their action in producing senility is exclusive, or even preponderating.
Weinberg, at the Pasteur Insti- tute, made special investigations on this point, and found that the thyroid gland and the suprarenal capsules were almost invariably normal in old animals cat, dog, horse , although the latter showed unmistakable signs of senility.As a matter of fact, the mechanism of bone atrophy must be placed in a different category from the phagocytosis of other organs. As in many birds the caeca are rudimentary and in others absent, it may be inferred that these organs Obi.E useless, and are in process of degeneration in the class. Lincei,vol xiv. Flash Player ZulaГџen is almost possible to imagine that there is some sort of intimate link, possibly physiological, between longevity and low fertility. It is useful as a means of interpreting the real nature of the process of senescence.
ISIS AKTUELLE KARTE Dieses Game mГsst ihr Sky VerlГ¤ngerung.
|BESTE SPIELOTHEK IN GALGENUL FINDEN||Beste Spielothek in Г¶rsdorf finden|
|Luxury Casino Account LГ¶schen||Beste Spielothek in Lutzenberg finden|