The effects of age and gender on sleep EEG power spectral density in the middle years of life (ages 20-60 years old)

The effects of age and gender on sleep EEG power spectral density were assessed in a group of 100 subjects aged 20 to 60 years. We propose a new statistical strategy (mixed-model using fixed-knot regression splines) to analyze quantitative EEG measures. The effect of gender varied according to frequency, but no interactions emerged between age and gender, suggesting that the aging process does not differentially influence men and women. Women had higher power density than men in delta, theta, low alpha, and high spindle frequency range. The effect of age varied according to frequency and across the night. The decrease in power with age was not restricted to slow-wave activity, but also included theta and sigma activity. With increasing age, the attenuation over the night in power density between 1.25 and 8.00 Hz diminished, and the rise in power between 12.25 and 14.00 Hz across the night decreased. Increasing age was associated with higher power in the beta range. These results suggest that increasing age may be related to an attenuation of homeostatic sleep pressure and to an increase in cortical activation during sleep.     

Cytokeratin expression in normal human thymus at different ages

Subsets of thymic epithellal cells were examined Immuno-histochemically to determine whether or not their pheno-types change during thymic growth and at early involution in terms of cytokeratin (CK) expression. Five monoclonal antibodies specific for CK4, CK8, CK13, CK18 and CK19 were used and applied for 16 neonatal, three Infantile and one adult thymus speeimen, which had been obtained at autopsy, that were normal macroscopically and microscopicaily. CK4, CK8, CK13, CK18 and CK19 were expressed simultaneously in the cortex, medulla and subcapsular area with the exception of CK4, which showed expression on the adult thymus. Light and electron microscopy showed that CK8 and CK19 expression was overlapped. Thus, It was thought that CK8 and CK19 formed complexes in the cytoplasm of thymic epithelial cells. The Immunoreactivity to CK4, CK13 and CK18 were attenuated or disappeared In the subcapsular area during the early involution stage. Interestingly, two patterns of CK18 expression were observed in the neonatal and Infantile thymus tissues, which Indicated that the thymic microenvironment was changeable even under normal conditions.     

Wiedemann‐Rautenstrauch (neonatal progeroid) syndrome: New case with normal telomere length in skin fibroblasts

Wiedemann‐Rautenstrauch (neonatal progeroid) syndrome is an autosomal recessive condition with characteristic appearance of premature aging present at birth (aged face, natal teeth, and wrinkled skin). Other features of the syndrome are generalized lipoatrophy with specific fat accumulation in the lateral suprabuttock region, hypotrichosis, macrocephaly (pseudohydrocephalus), and mental retardation. We report on a new case that demonstrates all typical features of the syndrome. The girl is now 16 years and 10 months old and has had follow‐up from birth. We measured terminal restriction fragment (TRF) length to evaluate whether the patient's premature aging process is accompanied by shortening of telomere length in her cultured fibroblasts. Mean TRF of 13.5 kb found in our patient's fibroblasts is not shortened as compared to that of normal fibroblasts. Our results differ from those observed in Hutchinson‐Gilford progeria. © 2001 Wiley‐Liss, Inc.     

COMT Gene Polymorphism Is Associated with Declarative Memory in Adulthood and Old Age

Variation in memory performance is to a large extent explained by genes. In the prefrontal cortex, the catechol O-methyltransferase (COMT) gene is essential in the metabolic degradation of dopamine, a neurotransmitter implicated in cognitive functions. The present study examined the effect of a polymorphism in the COMT gene on individual differences and changes in memory in adulthood and old age. Tests assessing episodic and semantic memory were administered to 286 men (initially aged 35-85 years) from a random sample of the population (i.e., the Betula prospective cohort study) at two occasions followed over a 5-year period. Carriers of the Met/Met genotype (with low enzyme activity) performed better on episodic and semantic memory, as compared to carriers of the Val allele (with higher enzyme activity). Division of episodic memory into its recall and recognition components showed that the difference was specific to episodic recall, not recognition tasks; an effect that was observed across three age groups (middle-age, young-old, and old-old adults) and over a 5-year period. The COMT gene is a plausible candidate gene for memory functioning in adulthood and old age.     

Nuclear bodies in rat hepatocytes: Dynamics of appearance and formation during aging and functional loads

Department of Pathomorphology, A. V. Vishnevskii Institute of Surgery, Academy of Medical Sciences of the USSR, Moscow. (Presented by Academician of the Academy of Medical Sciences of the USSR D. S. Sarkisov). Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 113, No. 2, pp. 203–208, February, 1992.     

Morphometric and immunohistochemical characterization of the intimal layer throughout the arterial system of elderly humans

The purpose of the present study was to obtain insight into the natural development of adaptive intimal thickening and atherosclerosis in the arterial tree of human species. The morphometry and composition of the intimal layer were studied in the arterial system of elderly individuals. Post mortem, a total of 703 arterial segments were dissected from 24 subjects (age 81.9 ± 9.9 years). From each subject, segments were dissected from 31 different arteries. Area stenosis [(plaque area/vessel area) × 100%] was determined in each segment. By (immuno)histochemistry, lipid content and the presence of inflammatory cells (macrophages) were assessed in the coronary, common carotid, brachial, radial and internal iliac arteries. Adaptive intimal thickening or advanced atherosclerosis was observed in all studied artery types. Area stenosis was highest in the coronary arteries (median, 30%) and lowest in the arteries supplying the brain (median, ≤ 7%). Plaques hiding a lipid‐rich core and plaques with macrophage infiltration were observed in all five selected artery types. In summary, the present observation demonstrates that intimal thickening is a systemic process involving most artery types. Within elderly humans, features of advanced atherosclerotic disease, a lipid‐rich core and macrophages, can be observed in the intimal layer of artery types that are recognised for their relation with clinical syndroms as well as artery types that remain clinically silent.     

Cellular basis for the age-associated increase in autoimmune reactions

The mechanisms that lead to the increased expression of autoantibodies with age are poorly understood. We have studied the number, size, and density of spleen and peritoneal cells from young and old BALB/c and C57BL/6 mice as well as the frequency of clonal precursors for antibodies to mouse erythrocytes, thyroglobulin, and IgG in these lymphoid preparations. Old mice have a 6-fold increase in the number of resident peritoneal cells and a 2-fold increase in the absolute number of Ly1-bearing B cells in this population. Furthermore, old mice have twice as many large, low density splenic B cells as young mice. The frequencies of B cell clonal precursors for anti-BrMRBC and anti-thyroglobulin antibody-forming cells in old mice were 3-10 times greater than in young mice. In the same cultures, however, no increase in the frequencies of B cell clonal precursors for anti-IgG or anti-DNA antibody forming cells was detected in old compared to young mice. These findings and other data suggest that there are at least two families of B cell autoantibody precursors, one including anti-BrMRBC and anti-thyroglobulin autoantibodies, the other including anti-IgG and anti-DNA antibodies. Studies of the differential regulation of these two families of autoantibody precursors might contribute to a greater understanding of autoimmune phenomena in age and disease.     

Primary respiratory syncytial virus infection in mice

A mouse model of respiratory syncytial virus (RSV) infection is described. A high-titered, large-volume inoculum results in replication of RSV to a high titer in lungs of BALB/c mice. Mice older than 15 weeks of age are more susceptible to RSV infection. Titers up to 10(6.9) plaque-forming units (pfu)/gram lung can be attained in 32-week-old mice. Older mice experience a clinical illness manifested by ruffled fur, reduced activity, and weight loss. Lung histology of older mice infected with RSV shows bronchiolitis and increased number of lymphocytes and macrophages in alveolar spaces compared with that of mice less than 8 weeks old. This model will serve as the basis for investigating immunodeterminants of recovery and protection from RSV infection.     

Skeletal manifestations in Fryns syndrome

We report on a female baby with Fryns syndrome who died soon after birth. The patient had short limbs, coarse face, hypoplastic lungs, diaphragmatic hernia, and acral hypoplasia. Literature review disclosed varying degrees of skeletal manifestations in Fryns syndrome; short limbs may be a component of Fryns syndrome. © 1995 Wiley-Liss, Inc.     

猪升主动脉几何形态与显微结构的增龄性变化

目的:探讨猪升主动脉几何形态与显微结构成分在增龄过程中的变化规律,为猪→人异种心脏移植吻合血管提供必要的形态学基础。方法:应用组织学和计算机图像分析方法,对42例1～7月龄猪升主动脉进行计量形态学研究。结果:猪升主动脉的管径、壁厚、管腔面积、管壁面积与月龄间呈高度直线正相关关系(r分别为0.98、0.98、0.99、0.99,各P值均<0.001),它们分别以1.54mm月、0.15mm/月、28.26mm~2/月和12.28mm~2/月的速率增加。管壁中胶原纤维含量随之增加(P<0.05);弹性纤维含量以2、3月龄最高,而后维持在相对恒定水平,平滑肌的含量在增龄过程中未见明显变化(P>0.05)。结论:与人类相似,猪升主动脉几何形态、显微结构成分含量与年龄密切相关。