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Biomedical subjects

B Robinson

Publications and source records attributed to B Robinson.

At least 145 records · Page 8Linked to original sources
PubMed1986

Lacticacidaemia due to pyruvate dehydrogenase deficiency, with evidence of protein polymorphism in the alpha-subunit of the enzyme.

In three infants with neonatal lacticacidaemia, a deficiency in the E1 (pyruvate dehydrogenase) component of the pyruvate dehydrogenase complex was demonstrated in skin fibroblast cultures. Residual activities of the pyruvate dehydrogenase complex in the activated state were 1.6%, 3.9% and 18.8% of control values, respectively. Immunoprecipitation of extracts of cultures skin fibroblasts grown on 35S-methionine with anti-pyruvate dehydrogenase complex antibody revealed an abnormality in the E1 alpha-component of these three patients when visualised after sodium dodecyl sulphate/polyacrylamide gel electrophoresis. This component appeared to have a slightly lower molecular weight than did this protein from control cell strains. Cell strains from other patients with a deficiency of the pyruvate dehydrogenase complex did not exhibit this defect. Three patients also showed dysmorphism and developmental abnormalities of the central nervous system.

Animals↗
PubMed1986

Sequential nonstress testing with use of each fetus as its own control.

The sequential nonstress tests of 126 high-risk fetuses were assessed for baseline fetal heart rate, acceleration frequency, amplitude, and duration and the observance of fetal heart rate decelerations. In 108 fetuses (563 tests) with normal perinatal outcomes, no significant trends in these parameters were found. In 18 fetuses (104 tests) with perinatal compromise, 16 had significantly declining acceleration frequencies, 15 had decreasing acceleration duration, four had rising mean baseline rates, and seven, in their last test before delivery, had repetitive late or severe variable decelerations. The last tests of 11 of these 18 fetuses met institutional criteria for reactivity. When the nonstress tests of compromised fetuses were viewed sequentially, acceleration frequency declined by an average of 59% and acceleration duration by an average of 40%. Sequential assessment of the nonstress test, when compared with the use of standard reactivity criteria, improved test sensitivity from 39% to 89% and negative predictive value from 91% to 98%. We conclude that sequential nonstress test assessment in individual fetuses may improve the diagnostic value of this modality and lead to earlier recognition of fetal compromise.

Female↗
PubMed1986

Morbidity of cranial relapse in small cell lung cancer and the impact of radiation therapy.

Thirty-nine of 225 patients with small cell lung cancer developed brain metastases after the initiation of chemotherapy. Treatment with high-dose dexamethasone in all 39 patients and cranial irradiation in 32 patients resulted in a complete neurological recovery in only eight of 39 patients (20%). Twenty-one of 39 patients (53%) failed to derive lasting benefit from their palliative treatment. Thirteen of 24 patients with limited disease with cranial relapse had no clinical evidence of other distant metastases prior to death and in these patients the CNS disease was an important cause of morbidity. On the basis of this study, it appears that palliative treatment of overt cranial metastases is relatively unsuccessful and that patients with limited disease represent a group with much to gain from effective prophylactic cranial irradiation.

Actuarial Analysis↗
PubMed1986

Mixed tumor of the mediastinum.

A 36-year-old asymptomatic man was found to have a large middle mediastinal mass on a chest x-ray film. At surgery the tumor was located adjacent to the carina and beneath the aortic arch. It measured 7.0 X 5.0 X 4.0 cm and was well circumscribed and soft, with mucoid areas. The histologic features were those of a benign pleomorphic adenoma of salivary gland origin. This is, to our knowledge, the first reported case of primary pleomorphic adenoma of the mediastinum. We propose an origin from the ectopic salivary gland tissue. We also describe an additional patient in whom ectopic benign salivary gland tissue was found within mediastinal lymph nodes to support our hypothesis.

Adenoma, Pleomorphic↗
PubMed1986

Influence of hypoxia and an acidic environment on the metabolism and viability of cultured cells: potential implications for cell death in tumors.

Hypoxia and an acidic environment are known to occur in regions of solid tumors and might be involved in the causation of necrosis. The viability and energy metabolism of cells in tissue culture were therefore investigated under hypoxic and/or acidic conditions. Acute exposure of Chinese hamster ovary (CHO) cells or human bladder cancer MGH-U1 cells to hypoxia plus low pH (6.5 to 6.0) was cytotoxic in a time- and pH-dependent manner; surviving fraction was reduced to approximately 10(-4) following a 6-h exposure to hypoxia at pH 6.0. There was no effect on viability when aerobic CHO cells were exposed for 6 h at pH 6.0, or when either cell line was rendered hypoxic for 6 h at pH 7.0; MGH-U1 cells showed slight sensitivity to acidic pH in air. Decrease in viability of CHO cells incubated under acid conditions was observed over the range of oxygen concentrations from 0.2 to 0.05%, similar to the range which causes change in cellular sensitivity to radiation. Glucose consumption and lactate production by both cell lines were inhibited at low pH under both aerobic and hypoxic conditions. Cellular adenosine triphosphate (ATP) levels and the energy charge [(ATP + 1/2 adenosine diphosphate)/(adenosine monophosphate + adenosine diphosphate + ATP)] of CHO cells were reduced by about 85 and 25%, respectively, after a 6-h exposure to hypoxia at pH 6.0 but were not influenced by hypoxia or acid pH alone. Inhibition of glycolysis by incubation of CHO cells under hypoxic conditions in the absence of glucose (at pH 7.0) led to a larger fall in cellular ATP and energy charge, but cell survival fell to only approximately 10(-2) at 6 h. These results demonstrate that hypoxia and an acid environment interact to cause marked toxicity. A decrease in energy charge of the cells may contribute to loss of viability, but additional mechanisms appear to be involved.

Adenosine Triphosphate↗
PubMed1985

Partial pyruvate decarboxylase deficiency with profound lactic acidosis and hyperammonemia: responses to dichloroacetate and benzoate.

We describe the successful use of sodium benzoate in a neonate with hyperammonemia associated with congenital lactic acidosis caused by a partial deficiency of the E1 component of pyruvate dehydrogenase (PDH); of note, this biochemical disturbance has not been previously described in PDH deficiency. The pyruvate dehydrogenase complex in skin fibroblasts had 48% of normal activity with a deficiency of the E1 component. The infant presented with rapid onset of a severe metabolic lactic acidosis, hyperventilation, hyperammonemia, and coma. At 30 hours of age continuous peritoneal dialysis was started; however, plasma NH3 concentrations remained in the 300-400 micrograms/dl range over the next 12 hours. Sodium benzoate, 250 mg/kg, was infused intravenously with a decrease in plasma ammonia of 25 micrograms/dl/hr. Hippurate was documented in the urine and peritoneal fluid after benzoate therapy. At 10.5 months of age, 50 mg/kg dichloroacetate was administered orally under fasting conditions, which resulted in a 56 and 62% reduction in the serum lactate and pyruvate levels, respectively; after 2 weeks on dichloroacetate his fasting levels were significantly decreased. Fibroblast PDH activity responded similarly to this drug. In our patient sodium benzoate was rapidly effective in producing a decline in plasma ammonia that was associated with clinical improvement. We feel that its use in organic acidemias deserves further evaluation and, furthermore, that any child with suspected PDH deficiency requires a clinical trial of dichloroacetate.

Acidosis↗
PubMed1985

The U.S. Transuranium Registry report on the 241Am content of a whole body. Part II: Estimate of the initial systematic burden.

The estimated systemic burden of 0.3 muCi 241Am, made by the resident health physicist, has been compared to postmortem measurements using in-vivo counting equipment and radiochemical analysis of the donor's body. The health physicist's estimate was based on in-vivo measurements and urine excretion data obtained while the donor was still working, and it was logically assumed that the intake occurred about 1954 as a result of inhalation of Am-contaminated air. Based on additional data obtained by postmortem analysis, it seems more reasonable to assume for the purpose of scientific study and evaluation that the intake occurred in 1953, primarily as the result of a contaminated wound. Evaluations of the systemic burden using that assumption and three models indicate that the amount initially deposited could have been in the range of 0.2-1.1 muCi 241Am.

Accidents, Occupational↗
PubMed1985

External (combination) rhinoplasty approach for trans-sphenoidal adenectomy.

The external (combination) rhinoplasty approach and the sublabial approach to trans-sphenoidal adenomectomy have been used at this institution for seven years. A summary of experience with the external (combination) rhinoplasty technique in 10 patients is reported; and a comparison is made between this approach and the sublabial approach in 12 patients. Advantages unique to this approach are: the distance to the sphenoid sinus is decreased allowing greater ease of instrumentation, the Hardy speculum may be opened widely to increase exposure, uniquely this allows synchronous cosmetic or reconstructive septorhinoplasty, and this technique is also invaluable for revision surgery--especially when septal cartilage has been removed by a previous sublabial approach. Disadvantages of this technique are the external incision across the columella, which leaves an imperceptible scar of no clinical significance, and postoperative nasal tip edema, which resolves with time.

Adenoma↗
PubMed1984

Chemotherapy and irradiation in childhood Hodgkin's disease.

Eighty children aged less than 16 years with newly diagnosed Hodgkin's disease were treated between 1974 and 1982. Complete remission occurred in 95%, with actuarial five year overall survival of 94%, and relapse free survival of 82%: median follow up was 4.8 years. Sixty one children were staged clinically while 19 had staging laparotomies before treatment. Most received combined modality treatment with Ch1VPP chemotherapy (chlorambucil, vinblastine, procarbazine, and prednisolone) followed by irradiation of initial bulk disease. Nodular sclerosis predominated in both sexes, accounting for 60% of the total. Girls with stage IV disease, nodal sclerosis histology, and bulky mediastinal masses had a relatively poor prognosis. Ten children have relapsed, and three prolonged (6 to 7 years) second remissions have been observed. Four died of disease, and one from infection. Clinical staging, avoiding splenectomy, reduced the risk of serious infections. Our current policy is to treat stage IA disease with local irradiation and all other stages with chemotherapy, adding irradiation for bulky mediastinal disease.

Adolescent↗
PubMed1984

Intrasellar schwannoma: case report.

An unusual case of an intrasellar schwannoma radiographically simulating a pituitary tumor is reported. The literature on unusual intracranial locations of schwannomas and their possible origin is discussed.

Adult↗
PubMed1984

Helping hospitalized elderly: discharge planning and informal support.

The extent to which informal support systems substitute or provide linkages to formal support systems has been a source of controversy in many studies. Even the extent to which the formal system of discharge planing in acute care hospitals links patients to formal care systems afterwards in unclear and suggests that existing models are ideal and theoretical rather than established empirically. The Posthospital Support Study examined hospital-based discharge planing and services received in the two month period after hospitalization for 170 patients with either heart conditions, or hip problems which required operations. Discharge planners were found to provide for services which were third-party reimbursable. Although planners adhered verbally to a wholistic model of assessing patient need and used an interdisciplinary planning structure, in actual planning they adhered to a narrow medical model while assuming an underlying social model of services from informal supports. The main informal caregivers varied in the extend to which formal as well as other informal providers supplemented their care, with caregiving spouses carrying most of the burden alone. Patients were most likely to assess themselves as either needing services they were already receiving, or those which they or their caregivers had to arrange for themselves.

Aftercare↗
PubMed1984

Possible lithium-induced extrapyramidal effects in Alzheimer's disease.

Extrapyramidal symptomatology has previously been reported in patients on long-term lithium maintenance. This report emphasizes that, in the presence of organic mental disorder, even brief treatment with lithium may induce severe extrapyramidal signs. Furthermore, toxicity to lithium may occur even though serum lithium levels are at therapeutic levels. Following termination of lithium, symptoms subsided quickly in one patient (five days), but more slowly in the other (16 days). Possible pathophysiology of this phenomenon is discussed.

Alzheimer Disease↗
PubMed1983

Glucose transport and metabolism in cultured human skin fibroblasts.

Human skin fibroblast cultures, seeded at 10(5) cells/5 cm plate and allowed to grow to confluence at approx. 10(6) cells/5 cm plate, utilized a glycolytic mode of metabolism where the ratio of glucose utilized to lactate produced wa 0.62 +/- 0.05 (Zielke, R.H., Ozand, P.T., Tyldon, J.I., Sevdalian, D.A. and Cornblath, M. (1976) Proc. Natl. Acad. Sci. U.S.A. 73, 4110-4114) (mean +/- S.E.). When the glucose in the medium was exhausted, the lactate produced during the highly glycolytic phase was then reutilized. In monolayer cultures that had been washed with phosphate-buffered saline, rates of glucose utilization were measured at 0.25 and 2 mM glucose by monitoring the appearance of 3H2O from [5-3H]glucose. Rate of utilization for each concentration of glucose decreased markedly as the cultures became more confluent. This decrease also correlated with a reduced ability to transport glucose as measured by 2-deoxy-[3H]glucose uptake in washed monolayer cultures. In washed confluent culture of fibroblasts, glucose utilization was markedly decreased by the presence of pyruvate and lactate but not by glutamine. The respiratory inhibitors, rotenone and antimycin, did not increase the rate of glucose utilization except when added in combination with pyruvate. We conclude that cultured skin fibroblasts possess a highly glycolytic mode of metabolism but that this mode can become more oxidative in the presence of sufficient quantities of pyruvate and lactate.

Biological Transport↗