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Biomedical subjects

A H Reed

Publications and source records attributed to A H Reed.

18 recordsLinked to original sources
PubMed1995

Proliferative responses of T cells from the skin and nerve lesions of leprosy patients.

In the current study we compared the mitogenic responses of T cells from skin and nerve biopsies of leprosy patients with those of peripheral blood mononuclear cells (PBMC). Lymphocytes from these sources were cultured at < or = 100 cells/well in the presence of PHA, irradiated autologous feeder cells, and IL-2, and proliferation was assessed after 6 to 12 days. Whereas PBMC were capable of vigorous responses, the growth of cells from skin and nerve was markedly reduced. The diminished response was independent of the clinical status of leprosy patients and was also observed in skin-infiltrating lymphocytes from patients suffering from other disorders. Analysis of proliferative responses at 1 cell/well suggested both a reduction in precursor frequency and a decrease in mean burst size. Analysis of lymphokine production suggested that cultured cells from skin lesions had reduced IL-w and IL-4 production relative to PBMC generated under similar conditions. Equal numbers of CD3+ cells were present in each source, but lesion cells were enriched in CD45RA- "memory" T cells, as well as CD3+CD28+ T cells. However, these alterations in subpopulation distribution could not account for the substantial differences in proliferative potential. We conclude that significant differences exist in the activation potential of cells from different tissue sources.

CD28 Antigens↗
PubMed1994

Cellulose sponge punch for controlled mitomycin application.

We describe a new punch for cellulose sponges that helps to standardize the application of mitomycin during glaucoma filtration surgery. The punch was used to create 40 cellulose application disks. The height, diameter, and weight were measured in both wet and dry states. The disk dimensions and weights were reproducible, with a coefficient of variation less than 5 for all categories. The punch has been very useful in our clinical practice and research.

Animals↗
PubMed1994

Factors affecting articular cartilage thickness in osteoarthritis and aging.

OBJECTIVE: To test the hypothesis that both aging and osteoarthritis (OA) contribute to the variance of human articular cartilage thickness of the knee and whether these contributions occur predominantly at weight bearing cartilage sites. METHODS: Thin, sagittal magnetic resonance images (MRI) of both knees were examined in 52 patients with idiopathic OA of the knee of short duration (87%: < or = 4 years) and 40 reference subjects of comparable age and sex distribution. Articular cartilage thickness was measured at the weight bearing and nonweight bearing femoral condylar, tibial plateau, and posterior patellar sites. Multiple regression analyses were performed to examine the influence of OA, age, sex, obesity (body mass index), and bone size on cartilage thickness. RESULTS: Age accounted for a significant linear decrease (p < 0.001) in both lateral and medial weight bearing femoral cartilage thickness of both knees, but failed to account for any significant variance in thickness at other cartilage sites. OA accounted for a significant decrease (p < 0.02) in the thickness of the femoral articular cartilage in the medial and lateral right knee compartments and in the lateral left knee compartment, but not in the medial left knee compartment. Significant cartilage thinning could be detected by MRI in patients with OA, even when the joint space was normal radiographically. CONCLUSION: The asymmetric decrease in the left knee may reflect the effect of mechanical factors. Our data show that articular cartilage thickness decreases at the femoral weight bearing sites both with age and as a consequence of OA and that these contributions can be distinguished from one another.

Adult↗
PubMed1988

Localizing genes that defer senescence in Drosophila melanogaster.

Selection for age-specific reproduction has produced replicate stocks in which life span exceeds that in short-lived controls by about 30 per cent, in unpaired individuals. Crosses between a selected long-lived (L) stock, short-lived (S) stock and a strain with balancer chromosomes were used to create all possible combinations of their chromosomes. The longest and shortest-lived genotypes are found to be (LSL) and (SLS), with other combinations distributed between them approximately according to their first and third chromosomes. Longevity appears to be under polygenic control with contributing elements on all chromosomes. The third chromosome is by far the most influential, accounting for 66 to 72 per cent of the observed variation in females. The first chromosome is less effective. Epistatic interactions are more important in males than females, but are significant only in measurements of single individuals. Some controlling elements for longevity appear to differ in males and females. Crosses of selected stocks with known P and M-cytotype strains show no effect on either sterility or longevity.

Aging↗
PubMed1985

Influence of antecedent lymphoid surgery on the odds of acquiring rheumatoid arthritis.

The occurrence of rheumatoid arthritis (RA) and the extent of antecedent lymphoid surgeries was examined using case control study methods. Two hundred sixty-four patients with definite or classic RA were considered and 283 patients with rheumatic diseases presumably of nonimmunologic origin were used as controls. The odds for developing RA were found to be significantly higher for patients with multiple lymphoid surgeries (tonsillectomy and adenoidectomy or tonsillectomy and adenoidectomy plus appendectomy) and exhibited a gradient, increasing with more extensive surgery. Significant rank correlations were found in patients with RA between the age at tonsillectomy and the rheumatoid factor (RF) titer. An earlier tonsillectomy correlated with lower titers of RF. A significant decrease of serum RF titer was also seen in patients with RA subjected to tonsillectomy, adenoidectomy and appendectomy. We conclude that antecedent removal of lymphoid tissue from the tonsils, adenoids and appendix constitutes a risk factor predisposing to RA. Moreover, this risk seems related to the quantity of lymphoid tissue removed.

Adenoidectomy↗
PubMed1984

Aggressiveness of SJL/J lymphomas correlates with absence of H-2Ds antigens.

SJL/J lymphomas emerged as H-2Ds-negative variants upon transplantation of their respective H-2Ds-positive spontaneous tumors. Of nine spontaneous SJL/J lymphomas examined, only two contained detectable numbers of H-2Ds-negative tumor cells. Of seven successfully transplanted tumors, however, four emerged as predominantly H-2Ds-negative tumors by their second transplantation. Long term SJL/J lymphoma lines, RCS 5 and SJL/SJL, were also found to be H-2Ds-negative. The expression of H-2Ks and I-As were maintained on all tumor lines examined. H-2Ds-negative tumor cells were consistent stimulators of syngeneic lymphoproliferation, whereas tumors maintaining H-2Ds expression varied in their stimulatory capacity. Transplantation times required to achieve morbidity in syngeneic mice correlated with tumor cell expression of H-2Ds. Tumors maintaining H-2Ds expression were less aggressive and required 57 to 150 days to produce morbidity compared with highly aggressive H-2Ds-negative tumors that required only 7 to 10 days at one-quarter of the cell dose (10(7) cells). Growth curve analysis based on spleen weights (corrected for body weight) indicated that three types of SJL/J lymphomas could be identified based on their expression of H-2Ds and ability to stimulate syngeneic lymphoproliferation: 1) indolent, nonstimulatory H-2Ds-positive tumors; 2) indolent, stimulatory H-2Ds-positive tumors; and 3) highly aggressive, stimulatory H-2Ds-negative tumors.

Animals↗
PubMed1980

Survival of mice receiving melanoma transplants is promoted by hydroquinone.

In BALB/c female mice with melanoma transplants, the incidence of "takes" is decreased and survival is increased by hydroquinone, a melanocytolytic agent. The mechanism of drug action is suggested by via DNA. The significant and high degree of positive response to hydroquinone treatment in vivo is encouraging for the clinical management of melanoma with melanocytolytic agents.

Animals↗
PubMed1976

Sample stability: a suggested definition and method of determination.

We propose defining the stability of any chemical constituent of stored samples in terms that are quantitatively related to the precision of the measurement by which it is determined. We suggest that a constituent may be considered stable, for a stated period and under exactly defined conditions, when the average change in its measured value is less than a chosen number, K, of standard deviations of the data obtained by the measuring method over the concentration range in question. Based on this definition a technique utilizing a graphical truncated normal sequential test is presented as the appropriate experimental and statistical design for measuring stability. The statistical basis for the proposal is presented.

Chemistry, Clinical↗