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Biomedical subjects

H Moore

Publications and source records attributed to H Moore.

At least 73 records · Page 4Linked to original sources

T-cell growth factor production by adult, but not childhood. Acute lymphoblastic leukaemic cells.

The production of T-cell growth factor (TCGF) by acute lymphoblastic leukaemia (ALL) cells was determined in seven children and in three adults. A significant production of TCGF by adult, but not childhood, ALL cells was observed. The adult ALL cells were classified as "non-T-non-B" by surface marker analysis. It is suggested that TCGF production may not be confined to the cells of T-lineage.

Acute Disease↗

Development of a filter paper blood spot radioimmunoassay for thyroid stimulating hormone suitable for a regional neonatal screening unit.

The radioimmunoassay described measures TSH in dried whole blood spots collected from neonates onto filter paper Guthrie cards. Microgranular cellulose is added to the precipitating reagent at the critical separation stage of the assay to overcome imprecision caused by the presence of the filter paper sample disc in the tube. The method was developed for a regional neonatal screening unit and has been found to be very reliable during ten months' routine use. It was required to be as precise, sensitive, accurate, rapid, simple, and inexpensive as possible and suitable for use with automatic diluting equipment in order to process large numbers of samples. Other methods were examined for their suitability and found not to fulfil one or more of the above criteria.

Congenital Hypothyroidism↗

Childhood T-cell acute lymphoblastic leukaemia expressing "Ia-like" antigen:" a case report.

A 4-year-old girl presenting with vomiting, abdominal pain, and renal failure was found to have gross hepatosplenomegaly, a renal mass, and bilateral pleural effusions. A diagnosis of acute lymphoblastic leukaemia (ALL) was suggested by a peripheral white cell count (WCC) of 119,000 x 10(6)mm3, 57% blasts, 22% lymphocytes, and confirmed by bone marrow examination. Lymphocyte surface marker studies at diagnosis enabled classification as a T-ALL, with a significant proportion of the T cells also bearing receptors for the third component of complement (C3). Seventy-two percent of the peripheral blood mononuclear cells reacted with anti-Ia monoclonal antibody (FMC44), and a smaller proportion (25%) carried receptors for the Fc portion of IgG. The T-classification of this ALL was verified at central nervous system (CNS) relapse and at a subsequent nodal relapse. Double-marker studies on cells from the infiltrated lymph node prepared in suspension confirmed the presence of Ia-positive T cells. The Ia marker is usually a useful discriminant between T and non-T cells in normal and ALL cell populations. The case described here highlights the need for a panel of markers to be used in classification of childhood ALL and supports the suggestion that there is a distinct subtype of Ia-positive T-ALL.

Antigens, Surface↗

Suppressor cell activity in a proliferative disorder of T lymphocytes.

We report details of the immunological profile of a patient with the candidiasis endocrinopathy syndrome who has developed T-type chronic lymphocytic leukaemia. The patient is anergic to a panel of delayed hypersensitivity skin tests, and has poor in vitro mitogenic responses, but B cell function in vivo is not impaired. Subsequent functional studies have revealed that cells from the patient have a significant suppressive effect in coculture (P less than 0.05) on the responses of healthy donor lymphocytes (NR) to the mitogen phytohaemagglutinin (PHA). A degree of selectivity for the suppressive effect is suggested by the lack of similar effects on coculture responses to the mitogens concanavalin A (Con A) and pokeweed mitogen (PWM). Mitomycin C treatment of the patient's cells reduced their suppressive activity but significant suppression was still observed in the majority of PHA cocultures. The suppressor activity required the presence of the patient's cells in cocultures, as no suppression was observed when the patient's serum or cell culture supernatant were included instead of the patient's cells in NR cultures.

Adult↗

Influence of patient characteristics on peritoneal clearances.

Few studies have explored how patient characteristics may influence clearances. We sought to determine if patient age, sex, size, renal disease, blood pressure, hematocrit, serum total proteins and albumin affected peritoneal clearances, drainage volumes or dialysate protein concentration. We found inulin clearances to be related to surface area and total serum proteins. Creatinine clearance was related to age, serum albumin and hematocrit. Sex, blood pressure or type of renal disease did not influence peritoneal clearances.

Adolescent↗

Toward modeling age-related changes of attentional abilities in rats: simple and choice reaction time tasks and vigilance.

Fischer-344 rats aged 4, 12, or 18 months were trained in a simple or choice reaction time task (SRTT; CRTT). Animals were required to detect a brief (50 ms), rarely, and unpredictably occurring signal that was presented either at the central panel light (SRTT) or above one of the two levers (CRTT). Animals reported detection by pressing either lever (SRTT) or the cued lever (CRTT) within 3 s. False alarm rates were obtained from a nonsignal 3-s bin. In comparison to younger animals, 18-month-old animals showed a reduced signal detectability, and this effect did not interact with practice. These results suggest that age affected vigilance and practice did not attenuate this effect. The benzodiazepine receptor agonist chlordiazepoxide (at subsedative doses; 1, 3, and 5 mg/kg) and the beta-carboline ZK 93 426 (1, 3, and 5 mg/kg) failed to affect signal detectability. Scopolamine HBr and MBr impaired detectability and responsivity to a similar extent. However, scopolamine MBr, unlike the tertiary compound, failed to affect response accuracy in the CRTT. It is speculated that the failure of chlordiazepoxide to affect performance was related to low processing demands of both tasks. Although these behavioral models show good face validity, they do not allow determination of the major components of attentional processes (perceptual sensitivity, response criterion, processing capacity). Animal behavioral paradigms that allow determination of such components are required for the investigation of the neuronal basis of age-related changes in attentional abilities.

Aging↗

Potassium, but not atropine-stimulated cortical acetylcholine efflux, is reduced in aged rats.

Using in vivo microdialysis, cortical acetylcholine (ACh) efflux was measured in freely moving Brown Norway/Fischer 344 F1 rats, aged 4 or 22 months. The effects of local, intracortical perfusion of atropine (1.0 or 100.0 microM) via the dialysis probe were compared to local K+ (100.0 mM) stimulation in the presence of elevated extracellular Ca2+ (2.5 mM). Basal cortical ACh efflux in aged rats was similar to that of young animals. Administration of atropine (1.0 or 100.0 microM) via the cortical dialysis probe substantially increased cortical ACh efflux, but did not differentially stimulate ACh efflux in young and aged rats. In contrast, ACh efflux stimulated locally with K+ and Ca2+ was significantly reduced in aged rats relative to young adults. The implications of the dissociable effects of K(+)-depolarization and muscarinic blockade for local regulation of cortical ACh efflux in aged animals are discussed.

Acetylcholine↗

Experimental models to investigate the pathology of antisperm antibodies: approaches and problems.

Antisperm antibodies (ASA) can interfere with sperm function and fertilization. But we still know relatively little about the specific mechanisms that elicit an auto-immune response and we have a poor appreciation of the profile of ASA that lead to antibody-mediated infertility in the male. This brief review explores some of the experimental models, the current approaches and the problems associated with investigations of ASA.

Animals↗

Lean body mass estimation by creatinine kinetics, bioimpedance, and dual energy x-ray absorptiometry in patients on continuous ambulatory peritoneal dialysis.

Lean body mass (LBM), which is fat free body mass, can be used as an index of nutritional status. We evaluated three techniques for LBM estimation, including dual energy x-ray absorptiometry (DEXA), creatinine kinetics (CrKin), and bioimpedance (BI) in 10 patients on continuous ambulatory peritoneal dialysis (CAPD). Two different formulae were applied for BI LBM estimation, Segal (S) and Deurenberg (D). Mean values (+/- SEM) of LBM estimated were 48.2 +/- 3.6, 46.12 +/- 2.87, 43.32 +/- 3.87, and 41.27 +/- 4.26 by DEXA, BI-S, BI-D, and CrKin, respectively. LBM by CrKin was significantly lower than that by DEXA and BI-S values. There was no statistically significant difference between DEXA and BI-S values. Statistically significant correlations were found between LBM values by all methods. Particularly strong correlations were found between DEXA versus BI-S (r = 0.976) and BI-S versus BI-D (r = 0.98). Because clinical assessment of hydration status is inaccurate, and both BI and DEXA measure excess extracellular water in LBM, falling muscle mass may be missed by these techniques. The CrKin technique for estimating LBM at normal body fluid volumes (dry weight) may be a better index of nutritional status in patients on CAPD because this may truly reflect the dry LBM and changes in muscle mass. Both DEXA and BI include excess body water in LBM and may mask malnutrition in the presence of subclinical or clinical overhydration, which is common in patients on peritoneal dialysis.

Absorptiometry, Photon↗

Longitudinal evaluation of a renal Kt/V(urea) of 2.0 as a threshold for initiation of dialysis.

We (Perit Dial Int 17:426 and 497, 1997) and the Dialysis Outcomes Quality Initiative guidelines (Am J Kidney Dis 30:S69, 1997) have reported evidence that protein intake often is < 0.8 g/kg standard weight when renal weekly urea clearance (L) normalized to total body water (V, L) is less than 2.0, and that initiation of dialysis should be considered if nutritional status is decreasing. We have prospectively followed renal urea (C(urea)) and creatinine clearances (C(cr)) in 20 patients with chronic renal failure. Nine patients received dietary counseling, but we have previously shown this has minimal effects on protein intakes (Perit Dial Int 17:497, 1997). In 16 patients (group 1), glomerular filtration rate (GFR) estimated as (C(urea) + C(cr))/2 decreased from 14.6 +/- 1.5 (mean +/- SEM) to 9.8 +/- 0.9 (ml/min/1.73 m2 BSA) over a mean interval of 10.3 +/- 1.6 months; in the other 4 patients (group 2), mean GFR did not decrease and was initially 17.6 +/- 3.8 and 21.7 +/- 2.2 after 8.5 +/- 2.3 months. In group 1, Kt/V went from 2.5 +/- 0.3 to 1.7 +/- 0.2; in group 2, Kt/V went from 3.1 +/- 1.0 to 3.7 +/- 0.6. In group 1, protein intake as assessed from the normalized equivalent of protein nitrogen appearance calculated from urea nitrogen and protein losses in urine (nPNA; g/kg standard weight) went from 1.0 +/- 0.1 to 0.8 +/- 0.1. In group 2, mean nPNAs were 1.1 +/- 0.3 and 1.1 +/- 0.1. In all measurements with Kt/V less than 2.0 (n = 18), 10 (56%) were with nPNA less than 0.8. In all measurements of Kt/V > or = 2.0 (n = 22), only 3 (13.6%) were with an nPNA of less than 0.8. These percentage values were different (p < 0.0001) by chi-squared analysis. Changes in nPNA correlated directly (but insignificantly, probably because of a small n) with C(cr), GFR, and Kt/V. These prospective results provide additional evidence that protein intakes decrease to dangerously low levels (without intense dietary monitoring) in most patients when renal weekly Kt/V decreases to below 2.0, which is similar to findings in patients on continuous ambulatory peritoneal dialysis.

Adult↗