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B Ross

Publications and source records attributed to B Ross.

At least 19 recordsLinked to original sources
PubMed1992

Randomised controlled trial of cost-effectiveness of lithotripsy and open cholecystectomy as treatments for gallbladder stones.

Inpatient extracorporeal shockwave lithotripsy for treatment of gallbladder stones has not previously been compared with open cholecystectomy in terms of cost-effectiveness. In a randomised controlled trial, 163 patients, stratified by gallstone bulk (over 4 cm3 or not), were randomised to lithotripsy or cholecystectomy (38 large-bulk and 27 small-bulk cholecystectomy; 37 large-bulk and 61 small-bulk lithotripsy) and followed up for 1 year. Both treatments gave significant health gains in terms of a reduction in episodes of biliary pain, improved perceived health status, and symptom relief, but few differences between treatments were found. There was some evidence that biliary-pain episodes were less severe after cholecystectomy. Cholecystectomy patients also had greater improvements in mean health gain for three related symptoms: vomiting, feeling sick, and fatty-food upset. However, there were no differences between groups in perceived health status. Among lithotripsy patients, health gain was not related to stone clearance. Lithotripsy was more expensive than cholecystectomy, principally because of the costs of the inpatient stay and adjuvant bile-salt therapy. Conventional lithotripsy appears at least as cost-effective as cholecystectomy for patients with small-bulk stones but less cost-effective for those with large-bulk stones. To some extent treatment choice can be guided by patient preference.

Adult↗
PubMed1992

Amyl nitrite: use as a smooth muscle relaxant in difficult preterm cesarean section.

Amyl nitrite is a smooth muscle relaxant that has been used clinically to facilitate uterine relaxation in difficult deliveries. In this retrospective study, we evaluate the safety of amyl nitrite use during preterm cesarean deliveries, and we assess possible advantageous effects on surgical incision choice. Women who received amyl nitrite cesarean section were compared to a control group matched for gestational age, fetal presentation, and mode of delivery who did not receive amyl nitrite. There were no statistical differences between the groups in the independent variables (maternal age, parity, medical or obstetric history, type of anesthesia, anesthesia or obstetric attending physician, antepartum hematocrit, or neonatal weight). Outcome (dependent) variables (estimated blood loss, Apgar scores, postpartum hematocrit, cord gases, or postpartum complications) were assessed, and there were no significant differences between the groups. Low transverse cesarean section was performed more frequently in the amyl nitrite group (58 of 64) than in the comparison group (48 of 64) (p less than 0.03). Considering the 128 women with and without amyl nitrite together, the decrease in hematocrit observed postpartum was greater after classic section (7%) than after low transverse section (4%) (p less than 0.002). We conclude that the use of amyl nitrite during preterm cesarean section poses no threat to mother or fetus and may facilitate delivery by allowing the performance of a low transverse rather than a classic cesarean section without maternal or neonatal complications.

Amyl Nitrite↗
PubMed1992

Opposite sensitivity to the antiproliferative action of interferon-alpha and granulocyte-macrophage colony-stimulating factor in monoblastic U937 cells.

Three variants of the human monoblastic cell line U937 with different degrees of sensitivity to the antiproliferative action of interferon-alpha (IFN-alpha were examined for phenotypic differences. The highly IFN-sensitive variant U937-V expressed twice as many IFN-alpha binding sites as both its IFN-alpha-resistant derivative U937-VR and the cell line U937 exhibiting a 20-fold reduction in IFN-alpha sensitivity as compared to U937-V cells. All three variants were IFN-reactive with regard to induction of 2',5'-oligoadenylate (2-5A) synthetase activity and were similarly sensitive to the growth-inhibiting action of IFN-gamma and tumor necrosis factor. Responsiveness to the antiproliferative effect of granulocyte-macrophage colony-stimulating factor (GM-CSF), however, was confined to cell lines U937 and U937-VR. Although expressing a comparable number of GM-CSF receptors, the highly IFN-sensitive variant U937-V was refractory to GM-CSF. Flow cytometry revealed a marked difference in the expression of the antigen CD11b which was detectable on 85% of cells of the U937-V line but only on approximately 25% of cells derived from the U937 and U937-VR lines. Results thus demonstrate opposite sensitivity of U937 cells to the growth-inhibiting action of IFN-alpha and GM-CSF, apparently dependent on the state of U937 differentiation as determined by expression of the CD11b antigen.

2',5'-Oligoadenylate Synthetase↗
PubMed1992

Depression and support systems in male army HIV+ patients.

Psychiatric interviews were conducted with 55 male Army HIV+ patients. These soldiers were diagnosed in an early stage of HIV, and were not clinically demented. Sixty-four percent were given diagnoses of a depressive disorder by a psychiatrist, while 42% self-reported depression. Fifty-five percent had a history of suicidal thoughts since their diagnosis of HIV, but only one soldier was actively suicidal. Half said that they followed a more healthy lifestyle since their diagnoses. Factors associated with a high rate of depression included being divorced, of Hispanic origin, having other medical problems, or a history of mental illness. Not telling friends and family, or feeling a lack of support from them or the military, was also significantly correlated with depression.

Adult↗
PubMed1992

Primary carcinoma of the gallbladder: a 10-year experience.

New developments in the management of gallstone disease, and particularly percutaneous and extracorporeal treatments that leave the mucosa intact, have renewed interest in the relationship between cholelithiasis and carcinoma. These treatments are both available in our hospital and to examine this question we studied the patients presenting between 1980 and 1990 with gallbladder cancer. The study comprised 21 patients with histologically proven carcinoma. The M:F ratio was 1:4 with a mean age of 76 years. Gallstones were present in 18 patients (85.7%). Ten patients remain alive today and in the 11 who died the median survival was 4 months. A preoperative diagnosis was made by ultrasound in only two patients. The lack of a preoperative diagnosis in the majority of patients is clearly a cause for concern and while our figures, like other series, do not establish a causal relationship with gallbladder carcinoma, it is vital to be diligent in the follow-up of high-risk patients (stones greater than 3 cm) with intact gallbladder mucosa after the treatment of stone disease.

Aged↗
PubMed1991

Acute ototoxicity of trialkyltins in the guinea pig.

Two trialkyltin compounds, trimethyltin chloride (TMT) and triethyltin bromide (TET) were evaluated for their acute effects on cochlear function in pigmented guinea pigs. Compound action potential (CAP) thresholds and 1 microV RMS cochlear microphonic (CM) isopotential curves were generated for 25 subjects following ip injection of TMT (2 mg/kg), TET (12 or 24 mg/kg) or inert vehicle (0.9% saline or 15% ethanol). The CAP is generated by the release of neurotransmitters from the inner hair cells and the subsequent depolarization of spiral ganglion cells. However, the sensitivity of the CAP is influenced by other cochlear structures including the outer hair cells which are thought to influence sensitivity of the inner hair cells. By contrast, CM reflects electromechanical function of the outer hair cells. CAP function was severely disrupted by organotin exposure while CM was unaffected by these agents. TMT administration impaired CAP thresholds at all frequencies within 30 min of administration. Thresholds deteriorated slightly more between 30 and 60 min. TET also reduced the sensitivity of the CAP to all frequencies. At the lower dose moderate impairments of function were observed at 30 min which became more noticeable at 60 min. Following 24 mg/kg TET injection, CAP sensitivity was markedly impaired even at 30 min. The CM isopotential values were not significantly altered 30 min or 60 min after either TMT or TET treatment at any of the 11 frequencies tested. These data document far more rapid toxic effects of TMT and TET than have been seen in most intact neuronal systems. They indicate that both organotins initially disrupt the functional integrity of either inner hair cells or spiral ganglion cells within the cochlea such that depolarization occurs only following a significant increase in stimulus intensity.

Action Potentials↗
PubMed1991

Evidence that gonadal hormone levels in amniotic fluid are decreased in males born to alcohol users in humans.

Biochemical evaluation of amniotic fluid content is often used to monitor fetal secretory and excretory functions. It is known that alcohol freely passes through the placenta and enters the fetal tissues. The study was designed to investigate whether alcohol use during pregnancy affects amniotic fluid steroid and peptide hormone levels. Five alcohol users who drank between 40 and 45 drinks per month and consumed approximately 1 oz. of alcohol per day from beer drinking participated in the study. Thirteen controls with no history of alcohol use including essential and non-essential drugs were selected for the study. The final selection of participants was made among those who delivered male offsprings. Amniotic fluid was aspirated between 16 and 20 weeks of gestation by amniocentesis and an aliquot was used to assay steroid hormones (4-androstenedione [-4-AD], testosterone [T], estradiol [E2], dehydroepiandrosterone sulfate [DHEA-S]), and peptide hormones (FSH and LH). Birth weights, placental weights and gestation age were recorded at birth. The results showed that -4-AD, T and E2 levels were significantly decreased (P less than 0.01) in alcohol users; DHEA-S, FSH and LH levels were unaffected. Birth weights were significantly decreased (P less than 0.05) in alcohol users, the placental weights and gestation age were not affected. We conclude that alcohol passes through the placenta and affects fetal testes, capacity to synthesize steroids and the effect appears to be direct and not via the hypothalamic-hypophyseal axis.

Adult↗
PubMed1991

Efficacy of feedback training in long-standing facial nerve paresis.

An efficacious treatment has not been available to patients with aberrant regeneration of the facial nerve as a result of Bell's palsy or after acoustic neuroma excision. This prospective controlled trial examines the efficacy of electromyographic feedback versus mirror feedback as treatment strategies for patients suffering from long-standing (18 months minimum) facial nerve paresis. Twenty-five patients were randomly assigned to electromyography with mirror feedback or mirror feedback alone. Seven rural patients who did not undergo treatment served as controls. At 0, 6, and 12 months, facial motor function was objectively quantified by linear measurement of facial movement, visual assessment of voluntary movement, and electrical measurement of facial nerve response to maximal stimulation. Statistically significant improvements were noted in both electromyography and mirror-feedback groups with respect to symmetry of voluntary movement (P less than .03) and linear measurement of facial expression (P less than .01). The positive results of this controlled trial demonstrate that feedback training in combination with a structured home rehabilitation program is a clinically efficacious treatment for patients with facial nerve paresis.

Adult↗
PubMed1991

Renal corticomedullary metabolite gradients during graded arterial occlusion: a localized 31P magnetic resonance spectroscopy study.

In order to investigate the role of the outer medulla in acute ischemic renal failure (Epstein FH, Balaban RS, Ross BD: Redox state of cytochrome aa3 in isolated perfused rat kidney. Am J Physiol 1982;243: F356-F363), the distribution of ATP in the in vivo porcine kidney and its relationship to Na transport and to ischemia was examined by using localized 31P magnetic resonance spectroscopy. Renal cortex (ATP) was higher than medulla. Reduction in Na transport produced by partial renal arterial occlusion ("hypofiltration"), resulted in a 13% increase in the ATP/Pi ratio of the whole kidney (from 2.61 +/- 0.26 to 2.96 +/- 0.27; P less than 0.03). This increase was accounted for by a statistically significant increase in (ATP) in the cortex, with medulla contributing to an insignificant extent. Further occlusion of the renal artery to reduce GFR to zero ("hypoperfusion") resulted in a 70% fall in ATP/Pi ratio. (ATP) was reduced most in the cortex, but pH fell equally in cortex and medulla. After release of arterial occlusion, cortical ATP recovered less completely than medulla ATP. Intracellular pH and Pi were restored in both cortex and medulla. It was concluded that cortex and medulla contribute equally to the pattern of disordered energy metabolism in acute renal failure. Sparing of ATP during hypofiltration may reflect the reduced energy requirements of active Na transport.

Adenosine Triphosphate↗
PubMed1991

Pharmacokinetics of percutaneous estradiol: a crossover study using a gel and a transdermal system in comparison with oral micronized estradiol.

The pharmacokinetics of three transdermal estradiol (E2) replacement regimens were studied following establishment of steady-state dynamics. Oestrogel 3.0 mg, Oestrogel 1.5 mg, and Estraderm transdermal delivery system 4 mg (0.05 mg/day) were administered for 14 days each to 15 postmenopausal volunteers, with a 14-day washout period between each regimen. The percutaneous E2 pharmacokinetics were compared with an oral micronized E2 preparation. Venous samples were obtained at 0, 1, 2, 4, 8, 12, and 24 hours on 3 sequential days 11 days after initial application of the Oestrogel and the transdermal delivery system, and at the same times after oral E2 ingestion. All three percutaneous regimens provided nearly constant serum E2 and estrone (E1) levels throughout their use. The mean serum E2 levels were 102.9 +/- 39.9, 68.1 +/- 27.4, and 41.1 +/- 13.5 pg/mL for Oestrogel 3.0 mg, Oestrogel 1.5 mg, and Estraderm, respectively. Oral E2 resulted in a mean serum E2 level of 114.0 +/- 65.2 pg/mL with marked peak and nadir values. The E1/E2 ratio was comparable with all three percutaneous regimens (1.08-1.33) and was significantly lower than that found with oral Estrace (5.05).

Administration, Cutaneous↗
PubMed1990

Lithotripsy.

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Humans↗
PubMed1990

Lymphocyte metabolism and cytotoxic activity monitored with 31P magnetic resonance spectroscopy.

Continuous metabolic monitoring of human lymphocytes and a tumor cell line was achieved by means of nuclear magnetic resonance (NMR) applied to cells suspended in alginate gels. Human peripheral blood lymphocytes cultured in vitro were examined with 31P magnetic resonance spectroscopy (MRS) before and after activation with phytohemagglutinin and interleukin-2 (IL-2). Following the addition of these biological response modifiers, increases in [ATP], phosphomonoesters (PME), and phosphodiesters occurred. These appear to be markers of lymphocyte stimulation. Lymphocyte pH was unchanged. A target tumor cell line (K562) showed 31P NMR spectra that differed significantly from that of lymphocytes. When lymphocytes were mixed with tumor cells (to induce tumor cell death), and monitored by 31P MRS, levels of inorganic phosphate (Pi) increased, [PME] levels fell, and release of H+ was inhibited. 31P MRS may therefore provide a noninvasive assay of lymphocyte-mediated tumor cell killing that will have application in monitoring treatment in patients undergoing this type of therapy.

Adenosine Triphosphate↗
PubMed1978

Effect of a lipid load on blood and urinary carnitine in man.

Blood and urine carnitine contents have been determined in patients before and after a lipid load and in patients on haemodialysis. Oral and intravenous lipid administration significantly depressed blood carnitine content and after 500 ml intravenous Intralipid urinary carnitine excretion fell by 43%. Blood carnitine was reduced by 50% by haemodialysis and returned to the pre-dialysis value within 20 h in 5 out of 8 patients. It is concluded that the blood carnitine level is normally controlled over a narrow range. The fall in blood carnitine concentration and urine excretion which follows a lipid load indicate a limiting role for carnitine in lipid utilization in man, and suggest that carnitine supplements could be of value during parenteral nutrition with fats.

Administration, Oral↗