ISSN:0304-324X    

DOI:10.1159/000212312

出版商:S. Karger AG    

年代:1979

数据来源: Karger

摘要:

Form birefringence curves and linear dichroic properties of aging rat tendons are different from those of adult controls. The steepness of the form birefringence curves and the increased retardations found in aging tendons are ascribed to an increase in collagen aggregation accompanied by loss of tissue water. Based on increase of retardations due to intrinsic birefringence, a rise in crystallinity levels is suggested for the collagen bundles of aging tendons. The inversion of the dichroism signs and the change in the d∣∣ (collagen fibers oriented parallel) and d1 (collagen fibers oriented perpendicular) spectral absorption profiles, mainly at the absorption peaks for sections stained with toluidine blue solutions at pH 4.0 and 5.0, indicate modifications at the acid glycosaminoglycan molecular orientation level with advancing

ISSN:0304-324X    

DOI:10.1159/000212314

出版商:S. Karger AG    

年代:1979

数据来源: Karger

摘要:

The endogenous oxygen uptake and the uptake with added substrate of whole-brain and mid-brain homogenates were significantly lower in older lizards as compared to younger. Both whole brain and mid-brain showed responses to cold stress for different lengths of time but the decline in oxygen uptake was more pronounced in the younger age-group. Respiratory rate and response to cold stress were more marked in the mid-brain than in the whole brain. Basing on earlier reports on mammals and on the present findings, it is suggested that the decline in physiological adaptation in older animals may be a general feature in vertebrates.

ISSN:0304-324X    

DOI:10.1159/000212315

出版商:S. Karger AG    

年代:1979

数据来源: Karger

摘要:

The influence of maturation and senescence on the mechanical strength of bone was studied in rats by measuring the breaking load of the femur shaft and calculating the breaking strength. Strength of cartilage was studied by determining the ultimate load of femoral epiphyseal plate. A sharp increase of all mechanical parameters was found between the age of 1 and 4 months which was attributed to a maturation process. The maximum was achieved at 1 year followed by a decrease in all parameters. This was considered to reflect the aging or senescence process. The following biochemical parameters were determined in the same specimens: collagen and its soluble fractions, glycosaminoglycans, the fractions thereof, and elastin. The content of insoluble collagen was very closely correlated to the strength data, thus demonstrating an increase between 1 and 4 months, a plateau up to 1 year and a decrease at 2 years. During the maturation process, the glycosaminoglycans, especially the chondroitin sulfates, fell considerably. But also during the aging period, a further decrease was noted. The elastin content fell only slightly during the whole life span. The excellent correlation between strength parameters and content of insoluble collagen as found previously in skin could thus be confirmed. Strength of bone is apparently not dependent on the content of glycosaminoglycans and elastin. This indicates the major role of insoluble collagen for the mechanical properties of connective and supporting tissue. The studies presented here show that in rat bone the senescence process can be separated from the maturation process.

ISSN:0304-324X    

DOI:10.1159/000212316

出版商:S. Karger AG    

年代:1979

数据来源: Karger

摘要:

The vascular system of 30 old asymptomatic patients (average age 62.5 years) was studied by reflection plethysmography. The plethysmogram (PTG) was recorded from the forefinger of the left hand at rest, during two postural tests (+ 45° arm-up and –45° arm-down), after physical work, and during the infusion of nitroglycerin and the β-agonist metaproterenol. 50% of the subjects presented a normal PTG under basal conditions. However, pathological PTGs were recorded after the various tests: 23.3% with the arm-up test, 6.6% with the arm-down test, 52% with the effort test, 31% with the nitroglycerin test and 73.9% with the metaproterenol test. Clearly, the effort and metaproterenol tests are pathological in the majority of cases, both tests inducing physiologically vasodilation and increase in the peripheral pulse. The arm-down test, which usually induces vasoconstriction, is almost always normal. Since the percentage of pathological responses to the nitroglycerin test is significantly smaller than that to the effort and metaproterenol tests, it is concluded that the vascular changes induced by aging are primarily functional, at least in asymptomatic subjects. Aging more negatively influences the vasodilating than the vasoconstricting abi

ISSN:0304-324X    

DOI:10.1159/000212317

出版商:S. Karger AG    

年代:1979

数据来源: Karger

摘要:

A quantitative survey was carried out on the subcutaneous and abdominal adipose tissue of two inbred strains of mouse; STR/ORT is a strain in which the knee joints of the males have a very high incidence of osteoarthrosis, whereas the incidence of the disease in the females is much lower; the CBA/ORT mice represent a normal laboratory strain which rarely suffers from osteoarthrosis. In terms of the weight of readily removable subcutaneous and abdominal adipose tissue, the male STR/ORT mice were slightly leaner than the male CBA/ORT mice, the female STR/ORT mice were obese when compared with their CBA/ORT counterparts. Thus, in these mice, there was no positive correlation between obesity and osteoarthrosis. This evidence confirms previous mouse studies and is contrary to the commonly held view that in humans obesity predisposes to osteoarthrosis.

ISSN:0304-324X    

DOI:10.1159/000212318

出版商:S. Karger AG    

年代:1979

数据来源: Karger

摘要:

The prevalence and causes of anemia in the elderly have been studied in 142 individuals aged 60-99 in a small rural community in which a high prevalence of nutritional anemia in pregnancy and childhood has been previously shown. The mean hemoglobin levels of elderly patients were significantly lower than those of the control groups of younger individuals and the prevalence of anemia increased with age. However, the reduction of hemoglobin was slight and in only 2% of the subjects studied has an anemia of less than 10 g/dl been found. The mild reduction of hemoglobin in the elderly population was paralleled by a slight, but significant reduction in serum iron, red cell folates and serum vitamin B12, and a slight increase in TIBC. Therapeutic trial with folic acid failed to improve hemoglobin levels but iron therapy resulted in an increase of at least 1 g/dl in about half of the patients with less than 13 g initial hemoglobin. In the rest of the patients who failed to respond to either folate or iron therapy, anemia was most probably the consequence of underlying chronic disorders where inflammation and renal insufficiency might have been the mechanism responsible for reduced hemoglobin levels. The relatively low prevalence and the mildness of nutritional anemia in the elderly, as opposed to the high prevalence and the severity of anemia in children and pregnant women in the same community, seems to support the contention that increased demand, rather than limited supply is the main factor responsible for the development of nutritional anemia.

ISSN:0304-324X    

DOI:10.1159/000212319

出版商:S. Karger AG    

年代:1979

数据来源: Karger

摘要:

In order to study changes in the pharmacokinetics of salicylates in old people, we used two groups of inpatients without hepatic or renal impairment: the first comprised 15 patients more than 65 years old, mean age 77 years; the second, 7 patients of mean age 21 years. Each patient was given 1 g of acetylsalicylic acid orally in the morning while fasting. Blood samples were subsequently taken after 30, 60 and 90 min and 2, 3, 4, 6, 8, 10, and 24 h. Fluorimetric assay results were analyzed kinetically with a mathematical model corresponding to a single diffusion compartment model. The results showed only a slight increase in the absorption half-time in old subjects, and a marked increase in elimination half-time (3.71 and 2.38 h in old and young subjects, respectively; t = 2.33: p < 0.5) and in the volume of distribution (5.51 and 3.83 liters respectively; t = 3.20: p < 0.1). On the other hand, bioavailability varied little, as did metabolic clearance. This study confirms that intestinal absorption of this drug is not much impaired in old people, while hepatic and/or renal elimination functions are changed. This finding agrees with results found for aminopyrine, antipyrine, and digoxin.

ISSN:0304-324X    

DOI:10.1159/000212320

出版商:S. Karger AG    

年代:1979

数据来源: Karger

ISSN:0304-324X    

DOI:10.1159/000212321

出版商:S. Karger AG    

年代:1979

数据来源: Karger

ISSN:0304-324X    

DOI:10.1159/000212322

出版商:S. Karger AG    

年代:1979

数据来源: Karger