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Biomedical subjects

A Richardson

Publications and source records attributed to A Richardson.

At least 271 records · Page 15Linked to original sources
PubMed1988

The age-related decline in interleukin-3 expression in mice.

Spleen lymphocytes form 5- to 37-month-old C57BL/6J mice were stimulated by concanavalin A (con A) in vitro, and the interleukin-3 (IL-3) expression was assessed by measuring the IL-3 activity in culture supernatants and the cytoplasmic IL-3 mRNA levels. The activity and mRNA level of IL-3 was maximum at 20 hr after culturing in the presence of con A. The IL-3 activity in the culture supernatants and the IL-3 mRNA level in lymphocytes declined 70% to 80% between 5 and 37 months of age. Northern blot analysis revealed no change in the size of IL-3 mRNA between young and old mice. When the expression of IL-3 and interleukin-2 (IL-2) by con A-stimulated lymphocytes was compared, both interleukins showed a similar declined with age.

Aging↗
PubMed1988

HLA product expression and lymphocyte subpopulations in jejunum biopsies of children with idiopathic protracted diarrhoea and enterocyte autoantibodies.

Mature enterocytes from normal human small intestine express HLA Class II molecules, whereas the immature enterocytes of the crypts are devoid of these products. By the use of the Avidin/Biotin immunofluorescence technique, we examined HLA Class I and II expression on cryostat sections of jejunum biopsies from 10 children with idiopathic protracted diarrhoea (IPD) and circulating enterocyte autoantibodies (Ec-Abs). The results were compared with those obtained on gut specimens from nine children with protracted diarrhoea but no evidence of circulating Ec-Abs and from one child affected by gluten-sensitive enteropathy. HLA Class I expression was similar in control and pathological specimens but jejunum biopsies from children with IPD and high titres of Ec-Abs (greater than or equal to 1:64) showed 'inappropriate' Class II molecule expression in the crypt epithelial cells. This was in contrast with normal or only mildly increased Class II reactivity in the mature villi enterocytes. Conversely, jejunum biopsies from children with IPD but with low levels of Ec-Abs (less than or equal to 1:4) possessed a moderate but distinct decrease of Class II expression in mature enterocytes with a decreased number of CD3 and CD8 intraepithelial lymphocytes. It is speculated that quantitative and qualitative variations of HLA product expression in the gut epithelium of children with IPD could reflect the severity of the autoimmune process underlying the clinical picture and point to heterogeneities within the autoimmune enteropathy syndrome.

Antibodies, Monoclonal↗
PubMed1988

Modulation of age-related changes in serum 1,25-dihydroxyvitamin D and parathyroid hormone by dietary restriction of Fischer 344 rats.

The purpose of this study was to determine the effect of food restriction on age-related changes in serum 1,25-dihydroxyvitamin D and PTH, two important regulators of Ca metabolism. Starting at 6 wk, male F344 rats were fed a purified diet either ad libitum (non-restricted) or 60% of ad libitum (restricted). Rats from each group were killed at 5, 13, 22 and 28 mo of age. Dietary restriction increased the median lifespan from 24 to 31 mo. It delayed the rapid decrease in serum 1,25-dihydroxyvitamin D from 1.5-5.0 mo in the non-restricted group to 5-13 mo in the restricted group. It also completely suppressed the marked rise in serum PTH which occurred at 22 and 28 mo in the non-restricted group. Dietary restriction had these effects even though both groups of animals consumed the same amount of Ca per gram body weight. Diet had no effect on serum Ca and P, except at 28 mo. These effects of dietary restriction on serum 1,25-dihydroxyvitamin D and PTH may result in altered Ca metabolism in dietary restricted F344 rats.

Aging↗
PubMed1988

One-step iodine starch method for direct visualization of sweating.

Despite recent progress in eccrine sweat gland physiology, simple, safe and reliable methods of visualizing local and generalized sweating are not available for clinicians and physiologists. We developed a simple one-step method for visualizing sweating that requires only soluble starch previously treated with iodine. When the powder is sprayed on the skin, sweat droplets are visualized as discrete dark purple dots. Since visualized dots are easily wiped off without staining the skin, sweating patterns can be obtained consecutively on the same skin site. The method is far superior to the classical Minor's method and is useful for clinical diagnosis of disorders of sweating and for visualization of the total body sweating for physiological studies. Two simple devices for spraying powder also have been presented.

Female↗
PubMed1988

Lethal osteogenesis imperfecta associated with 46,XY,inv(7)(p13q22) karyotype.

An infant who died of complications of osteogenesis imperfecta (OI) at 22 days of age had a 46,XY,inv(7)(p13q22) karyotype. His mother carried the same inversion. One breakpoint of the inversion was within the region of the gene for alpha 2(I) procollagen. The product of this gene is a component of type I collagen, the principal collagen synthesised by osteoblasts. Karyotypic abnormalities involving type I collagen gene sites have not previously been reported in association with OI.

Chromosome Aberrations↗
PubMed1988

Influence of exercise on the immune function of rats of various ages.

The purpose of this study was to determine whether exercise could prevent the age-related decline in mitogenesis, which has been well documented in rats, mice, and humans. At 1, 6, 12, and 18 mo of age, male Fischer F344 rats were subjected daily to swimming exercise for 6 mo. At the end of the 6-mo training period, spleen lymphocytes were isolated from the exercised rats and from age-matched sedentary controls. The induction of lymphocyte proliferation was measured with the mitogens concanavalin A (ConA) and lipopolysaccharide (LPS). In addition, the ability of the lymphocytes to produce interleukin 2 (IL 2) in response to ConA induction was measured. ConA- and LPS-induced proliferation decreased 41-63% between 7 and 25 mo of age in both exercised and sedentary control rats. ConA-induced IL 2 production decreased 42 and 62% between 7 and 25 mo of age for exercised and sedentary control rats, respectively. Although the age-related decline in mitogen-induced proliferation and IL 2 production was smaller in exercised rats, this was due to a lower level of mitogenesis and IL 2 production in lymphocytes from young exercised rats. Exercise resulted in a significant decrease (23-32%) in mitogen-induced lymphocyte proliferation and IL-2 production in 7-mo-old exercised rats compared with 7-mo-old sedentary rats. However, in the 18- and 24-mo-old rats, mitogen-induced lymphocyte proliferation and IL 2 production was not significantly different between exercised and sedentary control rats.

Aging↗
PubMed1987

Double-blind comparison of captopril alone against frusemide plus amiloride in mild heart failure.

Captopril alone as therapy for mild heart failure was compared with a combination of frusemide and amiloride in a double-blind randomised crossover trial in 14 patients who had previously been treated with diuretics. Although 10 patients remained stable on captopril alone, 4 patients deteriorated, with the development of pulmonary oedema of breathlessness. All 4 patients had had pulmonary oedema previously, unlike the patients who remained stable. Angiotensin converting enzyme inhibition alone is not sufficient treatment for patients with mild heart failure and a history of overt pulmonary oedema.

Amiloride↗
PubMed1987

Effect of age and dietary restriction on the expression of alpha 2u-globulin.

The effect of aging on the expression of alpha 2u-globulin was studied in liver tissue from 6-30-month-old male Fischer F344 rats. The synthesis of alpha 2u-globulin by suspensions of isolated hepatocytes decreased 90% between 6 and 22 months of age. The levels of alpha 2u-globulin mRNA and the transcription of alpha 2u-globulin genes by isolated liver nuclei decreased 80-85% between 5 and 24 months of age. Because alpha 2u-globulin has been suggested to be a "senescence marker protein," the expression of alpha 2u-globulin was measured in rats fed a diet restricted in calories. This dietary restriction procedure has been shown to increase significantly the longevity of rodents. The expression of alpha 2u-globulin was compared in liver tissue from 18-month-old rats fed ad libitum and a restricted diet (40% restriction of total calories). The synthesis, mRNA levels, and transcription of alpha 2u-globulin were 1.8-3-fold higher for liver tissue from restricted rats compared to liver tissue from rats fed ad libitum. Therefore, dietary restriction alters the age-related change in the expression of alpha 2u-globulin. Our results demonstrate that the changes in alpha 2u-globulin expression that arise during aging or dietary restriction are regulated at the level of transcription.

Aging↗
PubMed1987

Aging and lymphocyte cytoskeleton: age-related decline in the state of actin polymerization in T lymphocytes from Fischer F344 rats.

T cell functions are known to decline with age, but the underlying cause of the decline is unclear. Because of the importance of cytoskeletal elements in cellular functions, we examined the content and the state of polymerization of actin in lymphocytes from Fischer F344 rats of four different ages (6, 14, 23, and 31 mo). The cellular actin content was determined by a DNAase I inhibition assay. Our results indicate that the total actin content of spleen lymphocytes did not change significantly with age; however, polymeric actin content, particularly in T cells, decreased with age, which might be a result of the shift from the polymeric actin pool to the monomeric pool. Similar changes also occurred in B cells but to a lesser extent. We conclude that the state of polymerization of lymphocytes changed drastically with age, and that this might be an important factor in the age-related decline in the cellular functions of lymphocytes.

Actins↗
PubMed1987

Age-dependent changes of the mesenteric lymph node of Fischer F344 rats: morphological and histometric analysis.

Changes in mesenteric lymph nodes from Fischer F344 rats ranging from 5 to 37 months were studied by histological and histometric techniques. The most drastic histological changes were observed between 12 and 37 months of age. These changes include: loss of cellularity in the cortex; decrease in the number of germinal centers; distension of the medullary sinuses; decrease in the ratio of cortical area to medullary area; and infiltration of fibroblastic cells in the cortex and the medulla. Our results indicate a general structural disorganization in the mesenteric lymph node with increasing age. Such structural disturbance might be an important extrinsic factor for the decline in lymphocyte functions.

Aging↗
PubMed1987

Politics and policies on self-help: notes on the international scene.

This paper identifies and describes a few key milestones in the development of policies on self-help at an international level. At its core lies a paradox. Self-help groups are essentially a very local activity; they are generated by individuals coming together to help themselves and each other in their own local communities. They neither need nor are derived from international (or even national) policies for their development. Yet in the last few years, growing attention has been given, at international as well as national level, to the formulation of policies on self-help. It seems appropriate to take a look at what these are and in what ways they have had any local impact, if not directly, on groups, then indirectly, by affecting the climate in which they operate. The policies of two international bodies, both operating in Europe, are considered here. These are the European Community and the World Health Organization, including both its headquarters and the Regional Office for Europe. First, it is useful to set the context, to explore what is meant by a policy on self-help and to introduce some political considerations.

Europe↗
PubMed1987

Dietary restriction retards age-related decrease in cell population of rat corneal endothelium.

The surface areas of corneal endothelial cells from 12- and 18-month-old male Fischer 344 rats fed ad libitum or a calorie-restricted diet were compared. The rats fed the restricted diet in both age groups showed a statistically significant reduction in the mean cell area of the corneal endothelium. The data indicate that dietary restriction retarded the age-related endothelial cell loss and the subsequent enlargement that takes place to compensate for cell loss. This is the first report to suggest that dietary restriction retards age-related cell loss.

Aging↗
PubMed1987

A survey of lay and professional interest in self-care.

This article describes a survey of the extent of interest among medical professionals and representatives and members of patient organizations in expanding the use of self-care by people with chronic complaints. Patient organizations are essentially ;interest' groups, generally centred around a particular handicap or disease. From interviews with representatives from 52 patient organizations and with a random sample of 20 general practitioners, 21 specialists, 20 community nurses and 20 members of patient organizations, considerable interest was found in extending the practice of self-care. There was, however, some uncertainty about how to do this effectively. This study is part of a wider programme of research on the area between conventional health care and self-care.

Attitude of Health Personnel↗
PubMed1986

Protracted diarrhoea of infancy: evidence in support of an autoimmune variant.

Circulating autoantibodies to enterocytes were detected by indirect immunofluorescence in 14 out of 25 patients with idiopathic protracted diarrhoea of infancy. Similar specificities were not found in 50 control children with nongastroenterological disorders. The immunofluorescence pattern was more accentuated on the apical border of mature enterocytes. Enterocyte autoantibodies were mainly of IgG class (13/14), but 11 sera were positive for IgM and IgA classes, and five out of 14 positive sera also had the ability to fix complement. Absorption of sera positive for autoantibodies with an IgA coupled immunoabsorbent did not modify the intensity of the staining, indicating that these antibodies were not directed against secretory IgA. High titres and the complement fixing ability of enterocyte autoantibodies indicated a poorer prognosis despite the use of immunosuppressive drugs. Organ specific and non-organ specific autoimmune diseases or corresponding autoantibodies or both were often found in children with enterocyte autoantibodies and their family. These data show the existence of an autoimmune variant of protracted diarrhoea of infancy, despite the rare occurrence of autoimmune diseases in childhood.

Adolescent↗
PubMed1986

The effect of aging on the expression of interleukin 2 messenger ribonucleic acid.

It is well documented that the production of interleukin 2 (IL-2) by lymphocytes declines with increasing age. Using a cDNA probe to IL-2, the effect of age on the expression of IL-2 mRNA was studied on concanavalin A-stimulated lymphocytes. The induction of IL-2 mRNA by concanavalin A was maximum after 20 hr of incubation. Northern blots demonstrated that the cDNA probe to IL-2 hybridized to an 11 S to 12 S RNA species. No age-related change in the size of the IL-2 mRNA was observed. In addition, there was no evidence of an age-related change in IL-2 mRNA degradation or the post-transcriptional processing of IL-2 mRNA. The induction of IL-2 mRNA decreased 85% between 5 and 29 months and paralleled the decline in IL-2 production and lymphocyte proliferation. Therefore, the age-related decline in the ability of lymphocyte population to produce IL-2 arises from a decrease in the ability of the lymphocytes to genetically express IL-2 mRNA.

Aging↗
PubMed1986

Genetic expression of complement factors and alpha 1-acid glycoprotein by liver tissue during senescence.

The effect of age on several messenger RNAs coding for non-specific immune factors were determined in liver RNA isolated from 6-, 12-, 24-, 29- and 37-month-old male Fischer Rats. The levels of complement factors C3 and C4, complement protein factor B, and alpha 1-acid glycoprotein were determined by dot blot hybridization using cDNA probes. All four mRNAs increased slightly between 6 and 29 months of age. Only the mRNAs coding for complement factors C3 and C4 decreased significantly after 29 months of age. In addition, Northern blot analysis of the RNA preparations showed that the size of the four mRNA species did not change with increasing age. There was no evidence for age-related changes in the post-transcriptional processing or degradation of the mRNA species coding for complement factors C3 and C4, complement protein factor B, and alpha 1-acid glycoprotein.

Age Factors↗