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Biomedical subjects

B Myers

Publications and source records attributed to B Myers.

At least 37 records · Page 2Linked to original sources
PubMed2000

Natural killer-cell lymphocytosis and strongyloides infection.

We report a case of strongyloides infection in a 72-year-old man presenting with acute angio-oedema and urticaria. He was also found to have natural killer cell (NK) large granular lymphocytosis (LGL). We discuss the possible relationship between the strongyloides infection and the NK-LGL lymphocytosis.

Aged↗
PubMed1999

Multicenter clinical trial of recombinant human insulin-like growth factor I in patients with acute renal failure.

BACKGROUND: Patients with acute renal failure (ARF) have high morbidity and mortality rates, particularly if they have serious comorbid conditions. Several studies indicate that in rats with ARF caused by ischemia or certain nephrotoxins, insulin-like growth factor-I (IGF-I) enhances the recovery of renal function and suppresses protein catabolism. METHODS: Our objective was to determine whether injections of recombinant human IGF-I (rhIGF-I) would enhance the recovery of renal function and is safe in patients with ARF. The study was designed as a randomized, double-blind, placebo-controlled trial in intensive care units in 20 teaching hospitals. Seventy-two patients with ARF were randomized to receive rhIGF-I (35 patients) or placebo (37 patients). The most common causes of ARF in the rhIGF-I and placebo groups were, respectively, sepsis (37 and 35% of patients) and hypotension or hemodynamic shock (42 and 27% of patients). At baseline, the mean (+/- SD) APACHE II scores in the rhIGF-I and placebo-treated groups were 24 +/- 5 and 25 +/- 8, respectively. In the rhIGF-I and placebo groups, the mean (median) urine volume and urinary iothalamate clearances (glomerular filtration rate) were 1116 +/- 1037 (887) and 1402 +/- 1183 (1430) ml/24 hr and 6.4 +/- 5.9 (4.3) and 8.7 +/- 7.2 (4.4) ml/min and did not differ between the two groups. Patients were injected subcutaneously every 12 hours with rhIGF-I, 100 microgram/kg desirable body weight, or placebo for up to 14 days. Injections were started within six days of the onset of ARF. The primary end-point was a change in glomerular filtration rate from baseline. Other end points included changes from baseline in urine volume, creatinine clearance and serum urea, creatinine, albumin and transferrin, frequency of hemodialysis or ultrafiltration, and mortality rate. RESULTS: During the treatment period, which averaged 10.7 +/- 4.1 and 10.6 +/- 4.5 days in the rhIGF-I and placebo groups, there were no differences in the changes from baseline values of the glomerular filtration rate, creatinine clearance, daily urine volume, or serum urea nitrogen, creatinine, albumin or transferrin. In patients who did not receive renal replacement therapy, there was also no significant difference in serum creatinine and urea between the two groups. Twenty patients in the rhIGF-I group and 17 placebo-treated patients underwent dialysis or ultrafiltration. Twelve rhIGF-I-treated patients and 12 placebo-treated patients died during the 28 days after the onset of treatment. CONCLUSIONS: rhIGF-I does not accelerate the recovery of renal function in ARF patients with substantial comorbidity.

Acute Kidney Injury↗
PubMed1999

An investigation of male-mediated F1 effects in mice treated acutely and sub-chronically with urethane.

In order to investigate the alleged potential of paternally administered urethane to cause foetal abnormalities and heritable tumours, male CD-1 mice were treated with urethane, either acutely by intraperitoneal injection at doses of 1.25 and 1.75 g/kg bodyweight (bwt) or sub-chronically in the drinking water at 1.25 for 10 weeks, and 3.75 mg/ml for 9 weeks or vehicle for the control groups. They were mated to untreated females 1 week later. Uterine contents of half the pregnant females were examined just before full term, while the remaining females were allowed to deliver their litters. The resulting F1 offspring were observed for approximately 18 months and 12 months for acute and sub-chronic exposures respectively and subjected to necropsy examination. Some of the mice treated acutely with 1.75 g/kg bwt exhibited partial infertility but none of those treated with 1.25 g/kg bwt had an adverse effect on their reproductive ability. There was no genetic effect of acute urethane treatment on male germ cells as indicated by dominant lethality. After birth, there was an increase (P < 0.05) in post-implantation deaths possibly due to perinatal mortality. There was an increased incidence and earlier onset of liver tumours induced in F1 male offspring from F0 males treated with 1.75 g/kg bwt, (20.7% vs. 10.1%, P = 0.026) but not in the female offspring. F1 males from both treatment groups had mean bodyweights significantly higher than controls (P < 0.01). Some males from each dose group of the acute study were examined using the restriction site mutation assay involving analysis of exon sequences. No mutations were identified in testes, liver or spleen of DNA isolated from the urethane-treated animals. No reproductive or genetic effects were seen with sub-chronic treatment at either 1.25 or 3.75 mg/ml urethane nor was there any predisposition of F1 animals to tumours although observation times were shorter.

Abnormalities, Drug-Induced↗
PubMed1998

Renal blood flow: measurement in vivo with rapid spiral MR imaging.

PURPOSE: To assess the ability of three cine phase-contrast magnetic resonance (MR) imaging techniques to measure normal human renal blood flow (RBF) in vivo. MATERIALS AND METHODS: Eighteen healthy volunteers were studied with three cine phase-contrast MR imaging techniques: breath-hold, segmented k-space, two-dimensional, Fourier transform technique (ie, time-resolved imaging with automatic data segmentation, or TRIADS); a breath-hold rapid spiral acquisition; and a non-breath-hold rapid spiral acquisition that allowed resolution of both cardiac and respiratory cycles. In each case, total arterial RBF and blood flow per unit of renal volume were calculated. For each subject, RBF was measured with a standard technique of p-aminohippuric acid (PAH)-clearance hematocrit on the same day as the MR imaging examination was performed. RESULTS: The range of agreement (2 standard deviations, or 95% confidence interval) between RBF measurements obtained with the PAH-clearance hematocrit technique and the various cine phase-contrast techniques varied from +/- 17.6% to +/- 26.5%. The best agreement was obtained with non-breath-hold rapid spiral data, by using data from the end-expiratory phase of respiration. CONCLUSION: Findings with cine phase-contrast MR imaging employing rapid spiral acquisition are in good agreement with measurements made with PAH-clearance hematocrit and give the promise of clinical measurements of RBF.

Adult↗
PubMed1997

Comparison of two computational formulas for a WAIS-R seven subtest short form.

Several validity studies for a seven subtest WAIS-R short form have been conducted with patients from different populations as participants. All of these studies demonstrated high correlations between the short form IQ estimates and the actual VIQs, PIQs, and FSIQs (i.e., .90 to .98). In general, there also were small mean differences in the short form versus actual IQs across samples. There currently are two computational formulas for the seven subtest short form. The original weighted formula and a revised proration formula. This study investigated the accuracy of the two short form computational formulas in samples of patients with brain impairment. It was found that the two formulas produced nearly identical results from both statistical and clinical perspectives. Given that the formulas produce nearly identical results and the majority of published studies with this short form have used the weighted formula, we recommend that future investigators use the original weighted formula to maintain clinical and scientific consistency.

Algorithms↗
PubMed1997

Parvovirus-induced pancytopenia in a child with acquired haemolytic anaemia.

A 14-year-old boy, with acquired haemolytic anaemia secondary to paravalvular leak from a prosthetic aortic valve, presented with severe pancytopenia. Subsequent investigation showed serological evidence of recent parvovirus B19 infection. The patient required transfusion and subsequently improved rapidly, with maintenance of pre-infective haemoglobin levels. To our knowledge this is the first reported case in which infection with parvovirus has caused pancytopenia in an acquired chronic mechanical haemolytic anaemia.

Adolescent↗
PubMed1996

The indirect association of lactation with subsequent perimenopausal body weight.

OBJECTIVE: We aimed to estimate the relationship of prior breastfeeding to perimenopausal body mass index (BMI) (kg/m2). While most long-term studies of women's body weight after reproductive experience have found a negative relationship between lactation and body weight, most short-term studies found either no impact of lactation on body weight, or decelerated postpartum weight loss among breastfeeding women. DESIGN: We performed a retrospective cohort study. SETTING: The study was done in The Netherlands between 1987 and 1990. SUBJECTS: The 1067 singleton females who were born around the time of the Dutch famine (1 August 1944 through 15 April 1946) at The University of Amsterdam Teaching Hospital were all traced and accounted for. This analysis refers to the 671 who were interviewed and for whom all data elements were available. ANALYSIS: We related parity and number of children breastfed at least 1 week to BMI at age 45 and at the time of marriage, both calculated from respondents: recall of weight and height, by linear multiple regression analysis, adjusting for potentially confounding variables. RESULTS: Among parous women, each additional live birth was associated with a BMI increase of 0.69 kg/m2 (CI = 0.24 to 1.13, P = 0.003), and for each additional child breastfed, the BMI was lower by 0.41 kg m2 (CI = -0.77 to -0.04, P = 0.03) at age 45. However, BMI before any reproductive experience was 0.39 kg/m2 greater (CI = 0.08 to 0.71, P = 0.01) with each additional subsequent birth, and for each additional infant breastfed, 0.34 kg/m2 lower (CI = - 0.60 to - 0.09, P = 0.008). CONCLUSIONS: The negative relationship of prior breastfeeding to perimenopausal weight was probably not causally related to breastfeeding, since the relationship was present before any reproductive experience. The results could also arisen in part because of biased recall of weight; however, the relationship of parity to perimenopausal BMI was far less attenuated by adjusting for prior BMI than was the association with breastfeeding, lending support to an indirect association of breast- feeding with later BMI.

Bias↗
PubMed1995

Hepatitis C virus infection in multi-transfused children with haematological malignancy.

Transmission of hepatitis C virus (HCV) is an important hazard of blood transfusion and may result in chronic liver disease. 98 children from Nottingham and Sheffield with haematological malignancies were studied to determine the prevalence of HCV infection by enzyme immunoassay and RT/PCR techniques. The children had been exposed to up to 184 donors through red cell and platelet transfusion, the majority prior to routine testing for HCV infection in blood donors. Only one sample showed evidence of HCV infection being both ELISA and RT/PCR positive. None of the samples taken since donor screening were positive. This provides reassurance as to the low rate of HCV acquisition in multi-transfused patients in this part of the U.K. compared to other parts of the world.

Adolescent↗
PubMed1994

The application of the restriction site mutation assay to the study of the induction of mutations in the tissues of rodents.

The restriction site mutation (RSM) assay has been developed as a methodology for the study of base changes induced in restriction enzyme recognition sequences. In principle, the RSM methodology may be used to the study mutation induction in any organ, of any species, for which DNA sequence information is available. This paper describes the analysis of the induction of base sequence changes in restriction enzyme recognition sites present in the p53 and alpha-haemoglobin genes of male mice exposed to 1-ethyl-1-nitrosourea. Our results demonstrate the induction of G-->A transitions and G-->T transversions in a number of restriction enzyme recognition sites (BamH1, Pst1, Ban1, Msp1, Alu1) in DNA extracted from a number of different tissues from animals harvested 2-7 days after exposure. The data presented indicates that the RSM methodology has considerable potential for development for the study of induced base changes in the endogenous genes of a variety of species.

Animals↗
PubMed1993

Neuropsychologic effects of lithium discontinuation.

This study investigated the effects of blind lithium discontinuation and resumption on measures of cognition, creativity, and fine motor performance in 46 lithium-maintained euthymic outpatients. Scores on memory measures, tests of tapping speed, and associative productivity all improved significantly during the time off of lithium. In an effort to further explain these results, analyses were undertaken with six possible intervening variables: age, sex, lithium concentration in plasma, thyroid function, duration of lithium maintenance, and depressive symptoms. Significant group and interactive effects are reported and discussed. A multiple regression analysis suggested that lithium has a greater neuropsychologic effect in younger, less-depressed patients having higher lithium concentrations in plasma.

Adult↗