Search PubMed⌕ Search

Biomedical subjects

M J Bennett

Publications and source records attributed to M J Bennett.

At least 199 records · Page 11Linked to original sources
PubMed1990

Analysis of abnormal urinary metabolites in the newborn period in medium-chain acyl-CoA dehydrogenase deficiency.

In order to determine which are useful early diagnostic markers for medium-chain acyl-CoA dehydrogenase (MCAD) deficiency, we have analysed urine from an asymptomatic neonate. Profiling of urinary organic acids followed by peak confirmation by electron impact mass spectrometry revealed a high suberate/adipate ratio (greater than 1.0) and the presence of n-hexanoylglycine (HG). Acylcarnitine analysis by fast atom bombardment mass spectrometry (FAB-MS) was inconclusive, but FAB-MS/MS (tandem mass spectrometry) revealed diagnostic amounts of octanoylcarnitine and hexanoylcarnitine. Quantitative analysis of acylglycines by stable isotope dilution and chemical ionization mass spectrometry revealed a 30-fold increase in HG and increased suberylglycine, but no increase in 3-phenylpropionylglycine.

Acyl-CoA Dehydrogenase↗
PubMed1990

Decreased erythrocyte and platelet phospholipids and fatty acids in juvenile neuronal ceroid-lipofuscinosis (Batten disease).

Total cellular and phospholipid fatty acids were analyzed in erythrocytes and platelets from six patients with juvenile neuronal ceroid-lipofuscinosis (Spielmeyer-Vogt, Batten disease, JNCL). The results were compared to those of age-matched controls. The amounts of total fatty acid and the phospholipid classes, phosphatidylcholine (PC), phosphatidylethanolamine (PE), and phosphatidylserine (PS) were significantly decreased in patients when related to cellular protein. The reductions in total fatty acids were 27% in erythrocytes and 50% in platelets. Erythrocyte PC reduction was 36%, PE was 44% and PS 27%. There were no major qualitative differences in the phospholipid fatty acids, suggesting that the fatty acid composition of the reduced phospholipid was normal, and that there is a generalized phospholipid deficiency in these cells in JNCL. This was not related to nutritional status. The pathogenesis of Batten disease may be related to abnormal membrane function resulting from this marked phospholipid deficiency.

Adolescent↗
PubMed1990

Mucocele of the cystic duct remnant in eight liver transplant recipients: findings at cholangiography, CT, and US.

The case histories and radiologic studies of eight liver transplant recipients who developed a mucocele of the allograft cystic duct remnant were retrospectively evaluated. All patients had clinical and/or laboratory evidence of biliary obstruction or cholangitis from 2 weeks to 3.3 years following transplantation. Cholangiographic, ultrasound (US), and computed tomography (CT) images were available for review in eight, five, and four patients, respectively. Cholangiograms demonstrated an extrinsic mass compressing the common hepatic duct in seven of eight patients. US and CT showed fairly well- to well-defined round fluid collections adjacent to the common hepatic duct in three and two patients, respectively. The findings of this study suggest that the detection at cholangiography of an extrinsic mass compressing the common hepatic duct appears to be specific for a mucocele of the allograft cystic duct remnant. CT and US images may offer confirmatory evidence.

Adolescent↗
PubMed1990

A71378: a CCK agonist with high potency and selectivity for CCK-A receptors.

Receptors for the brain and gut peptide cholecystokinin (CCK) have been classified into two classes, CCK-A and CCK-B. To date, peptide analogues with selectivity for the CCK-B receptors have been identified, and selective antagonists for CCK-A and CCK-B receptors have been reported as well; until now, there have been no reports of highly selective CCK-A agonists. Herein we describe the properties of A71378 [desamino-Try(SO3H)-Nle-Gly-Trp-Nle-(N-methyl)Asp-Phe-NH2], a highly selective CCK-A receptor ligand. Characterization of A71378 was carried out in the guinea pig pancreas, cortex, gastric gland, and ileum, as well as in NCI-H345 cells. The IC50 values of A71378 for the pancreatic CCK-A, cortical CCK-B, and gastrin receptor were 0.4 nM, 300 nM, and 1,200 nM, respectively. A71378 proved to be a potent agonist in eliciting pancreatic amylase secretion (EC50 = 0.16 nM) and ileal muscle contraction (EC50 = 3.7 nM). In contrast, A71378 was relatively weak (EC50 = 600 nM) in mobilizing intracellular calcium from NCI-H345 cells, which express CCK-B/gastrin receptors. The high potency and selectivity of A71378 for the CCK-A over CCK-B and gastrin receptors is unprecedented among CCK peptides. Studies on CCK-7 analogues indicate that N-methylation of the Asp residue is responsible for the observed selectivity for CCK-A receptors. This discovery of a selective CCK-A agonist should prove valuable for studies aimed at understanding the physiological roles of CCK-A receptors in the brain and periphery.

Amino Acid Sequence↗
PubMed1990

Stigmatization: experiences of persons with acquired immune deficiency syndrome.

The purpose of this study was to understand the meaning that being stigmatized has for persons with Acquired Immune Deficiency Syndrome (AIDS). The research question for this investigation was, What is the perception of stigmatization as experienced by persons with AIDS? Phenomenology provided both the theoretical framework and the method for this study. The sample consisted of 10 homosexual men contacted through a New Orleans hospice, home health nurses, the investigator's own personal contacts, and referrals from men who were in the project. Participants were asked open-ended questions pertaining to changes in their relationships with others since diagnosis, changes in self-esteem, and examples of prejudice and discrimination. Interviews were audiotaped, transcribed verbatim, and analyzed using a qualitative approach. The phenomenon of stigmatization emerged as experiences of rejection and protection in social interactions.

Acquired Immunodeficiency Syndrome↗
PubMed1990

Medium-chain acyl-CoA dehydrogenase deficiency: a useful diagnosis five years after death.

We report a family in whom a fatal case of medium-chain acyl-CoA dehydrogenase (MCAD; EC 1.3.99.3) deficiency was diagnosed by enzymatic analysis of heart tissue that had been stored for five years. Three healthy siblings underwent subsequent investigation with the 3-phenylpropionic acid loading test. All siblings had been asymptomatic; however, one (age 2.5 years) excreted large amounts of 3-phenylpropionylglycine in response to the load and exhibited an organic aciduria consistent with the diagnosis of MCAD deficiency. The other two siblings did not demonstrate 3-phenylpropionylglycinuria after the loading test. This case underlines the importance of considering family history and using appropriate diagnostic tests in the recognition of hereditary metabolic disorders.

Acyl-CoA Dehydrogenase↗
PubMed1989

Primary hyperoxaluria (L-glyceric aciduria) in the cat: a newly recognised inherited disease.

The clinical features of a newly recognised inherited disease, primary hyperoxaluria in the cat, are reported. Affected cats developed acute renal failure between five and nine months old owing to the deposition of oxalate crystals in the tubules of the kidney. In addition to the signs attributable to kidney failure the affected animals became profoundly weak; there was evidence of denervation atrophy in skeletal muscle, and accumulations of neurofilaments were found in the proximal axons of the ventral horn cells and dorsal root ganglion cells of the spinal cord. Examination of urine from affected cats revealed L-glyceric aciduria and intermittent hyperoxaluria suggesting that the disease is a feline analogue of the human disorder, primary hyperoxaluria type 2. This supposition was confirmed by liver enzyme studies.

Acute Kidney Injury↗
PubMed1989

The catalytic function in psychotherapy.

Managed mental health care requires that psychotherapists translate their theories to fit consumer-driven systems. Core concepts such as motivation, resistance, and psychopathology can be understood operationally, as they relate to the relative flexibility and adaptability of the patient challenged by ordinary life events. When psychotherapy is viewed as inherently a change-facilitating process, subjugated to and oriented toward such events, the therapist's function is catalytic rather than analytic. The objective of therapy is to reinforce motives and mitigate obstacles to necessary change, through timely, focused interventions. A model is presented and case examples are used to illustrate how such an objective may be reached.

Adaptation, Psychological↗
PubMed1988

Acylcoenzyme A dehydrogenase deficiency in heart tissue from infants who died unexpectedly with fatty change in the liver.

Heart muscle from infants who died unexpectedly and who showed fatty changes in the liver at necropsy was analysed for long chain and medium chain acylcoenzyme A dehydrogenase activities by using the natural electron acceptor. In two of the seven cases investigated a deficiency in acylcoenzyme A dehydrogenase activity was found. In one case the deficiency was in medium chain acylcoenzyme A dehydrogenase activity and in the other long chain acylcoenzyme A dehydrogenase activity. These findings emphasise the importance of investigating fatty acid oxidation in infants who have died unexpectedly.

Acyl-CoA Dehydrogenase↗
PubMed1988

Therapeutic modification of membrane lipid abnormalities in juvenile neuronal ceroid-lipofuscinosis (Batten disease).

Five patients with juvenile neuronal ceroid-lipofuscinosis, who were shown to have absent or reduced serum prebetalipoprotein and a deficiency of polyunsaturated fatty acids in erythrocyte membrane lipids, were treated for a period of one year with supplements of fish oil extract (rich in omega-3 fatty acids) and encouraged to increase dietary intake of corn oil lipid (rich in omega-6 fatty acids) in an attempt to promote incorporation of these fatty acids into membranes. After one year there was a significant increase in omega-3 fatty acids (P less than 0.05) and in the total polyunsaturated fatty acids (P less than 0.02) in erythrocyte membranes but no change in the incorporation of omega-6 fatty acids. The patients were assessed clinically, psychometrically and neurophysiologically before and after the supplementation. No significant changes were noted after one year of treatment.

Adolescent↗
PubMed1988

The oxidation of octanoic acid by cultured amniotic fluid cells: the effect of cell type and passage number.

We have measured the rate of oxidation of [1(-14)C]octanoate in cultured amniotic fluid (AF) cells at various passages and in AF cell lines with different clonal morphology. It is possible that both the passage number and the cell type may influence the outcome of prenatal diagnosis of fatty acid oxidation defects using this technique. We found that there was no significant difference between the three major AF cell types (epithelial, large epithelial, and fibroblast) when analysed at identical passage number but there was a significant reduction in octanoate oxidation in all cell types with increasing passage. For reliable prenatal diagnosis, cell lines of similar low passage number should be used.

Acyl-CoA Dehydrogenase↗
PubMed1988

Molybdenum co-factor deficiency: an easily missed inborn error of metabolism.

A female patient is described with combined deficiency of sulphite, zanthine and aldehyde oxidase. She presented at the age of four weeks with intractable seizures. Initially the diagnosis was suspected because of a very low serum urate level (23 mumol/1-1). This condition can be easily missed and it is proposed that measurement of serum urate be included in the metabolic assessment of neonates with unexplained seizures and developmental delay.

Aldehyde Oxidase↗