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Biomedical subjects

C Smith

Publications and source records attributed to C Smith.

At least 703 records · Page 39Linked to original sources
PubMed1991

Bronchogenic cyst: a case report emphasizing the role of magnetic resonance imaging.

The article describes a patient with a right paratracheal bronchogenic cyst in whom the preoperative diagnosis was unclear. The fluid component of the cyst was not readily apparent by CT or T1-weighted MR images. Very intense signal on T2-weighted MR images suggested a cystic lesion. Inhomogeneities evident on MR but not CT images provided further soft tissue characterization. These soft tissue elements correlated with a macroscopic ring of hyaline cartilage in the resected specimen. The usefulness of MRI for the differential diagnosis of mediastinal tumors is discussed.

Adult↗
PubMed1991

Morphological development and fate of the mouse mesonephros.

A study has been made of the development of mesonephric tubules in the mouse to investigate the possible transdifferentiation of tubule epithelial cell to gonadal somatic cells and/or adrenal cortical cells. Immunohistochemical localisation of laminin was carried out to study the development of basal laminae. Cells at the ventral aspect of mesonephric tubules did not show an epithelial phenotype during the period of somatic cell population of the gonadal blastema; a basal lamina appeared ventrally only after this period. Therefore, it is not necessary to postulate transdifferentiation of these cells.

Adrenal Cortex↗
PubMed1991

Nonpharmacologic interventions for pain management.

Managing pain is a complex and inexact science. Acute and chronic pain physically and psychologically affects and disables an overwhelming number of people. Nonpharmacologic interventions for pain management have been reviewed. These methods can be used independently or in combination with other nonpharmacologic or pharmacologic methods of pain control. The goals of nonpharmacologic interventions for pain management include the reduction of pain, minimal adverse effects, and allowing patients to become active participants in their own care. Nurses are called on many times to comfort patients in pain. It is through their expertise and intervention that the goals of pain management succeed.

Acupuncture Therapy↗
PubMed1991

Electroconvulsive therapy revisited.

Electroconvulsive therapy (ECT) remains an extremely valuable tool in the treatment of certain psychiatric disorders. Despite the sensationalism of the past decade, ECT is the treatment of choice in severe depression that is unresponsive to other therapies or in patients who are overtly suicidal. In addition, ECT is particularly valuable in the elderly population, who are at risk for serious complications from the side effects associated with drug therapy. This report describes a case of recurrent depression in which ECT was successfully used.

Aged↗
PubMed1990

Human recombinant GM-CSF in allogeneic bone-marrow transplantation for leukaemia: double-blind, placebo-controlled trial.

In a randomised, double-blind trial 20 patients with leukaemia received human recombinant granulocyte macrophage colony-stimulating factor (GM-CSF) and 20 received placebo, for 14 days after allogeneic, matched sibling, bone-marrow transplantation. The neutrophil count recovered to 0.5 x 10(9)/l 3 days earlier in the GM-CSF group than in the placebo group (not significant), and the median neutrophil count at 14 days was significantly higher in the GM-CSF group (1.90 vs 0.46 x 10(9)/l). The lymphocyte count was significantly higher in the GM-CSF than in the placebo group between days 10 and 15 after transplantation, but this difference was not associated with a higher incidence of graft-versus-host disease. There was no evidence that GM-CSF was associated with a greater incidence of leukaemic relapse. The GM-CSF group had lower haemoglobin concentrations and platelet counts and higher plasma urea, creatinine, and bilirubin than the placebo group. The duration of hospital stay was the same for both patient groups. Further studies are now indicated to assess the overall effect of GM-CSF on outcome after allogeneic bone-marrow transplantation.

Adolescent↗
PubMed1990

Characterization and primary sequence of a human hepatic microsomal estriol UDPglucuronosyltransferase.

A human liver microsomal UDP glucuronosyltransferase (UDPGT) that demonstrates reactivity with estriol (pI 7.4 UDPGT) has been purified to homogeneity and characterized further. No activity toward morphine, 4-hydroxybiphenyl, bilirubin, or tripelennamine was observed. The estriol UDPGT shows immunoreactivity with antibodies raised against rat hepatic microsomal 3 alpha- and 17 beta-hydroxysteroid UDPGTs but not with antibodies raised against rat hepatic microsomal p-nitrophenol UDPGT. The NH2-terminal sequence of the purified protein was determined and found to correspond to an identical sequence in the deduced amino acid sequence of a cDNA obtained from a human liver library in lambda gt11 (HLUG4). Sequence analysis revealed that HLUG4 is 2094 bp in length and encodes a protein of 523 amino acids which has a 16 amino acid leader sequence, followed by an untranslated 3' region of 525 bp. Three potential N-glycosylation sites were identified in the predicted sequence. The deduced amino acid sequence of estriol UDPGT showed 82% identity with the deduced amino acid sequence of another human hepatic cDNA (HLUG25), which has been expressed as a UDPGT capable of 6 alpha-hydroxyglucuronidation of hyodeoxycholic acid, strongly suggesting that these proteins are members of the same gene subfamily.

Amino Acid Sequence↗
PubMed1990

Wound-induced phenylalanine ammonia-lyase in potato (Solanum tuberosum) tuber discs. Significance of glycosylation and immunolocalization of enzyme subunits.

1. Excised discs of potato (Solanum tuberosum) tuber were incubated with [3H]fucose and extracts were prepared and incubated with an antibody to phenylalanine ammonia-lyase. Analysis of the resulting immunoprecipitated proteins by SDS/PAGE showed [3H]mannose- and [3H]fucose-labelled bands with Mr values corresponding to those of phenylalanine ammonia-lyase subunits. 2. When potato discs were incubated with [3H]sugars in the presence of tunicamycin, an inhibitor of N-linked protein glycosylation, incorporation of radioactivity from [3H]mannose into the immunoprecipitated enzyme subunits was virtually eliminated, whereas that from [3H]fucose was only marginally inhibited. 3. Tunicamycin reduced the level of extractable phenylalanine ammonia-lyase activity induced in excised potato tuber discs. Kinetic analysis revealed that the Vmax value of the enzyme in crude extracts from tunicamycin-treated tissue was reduced, whereas the apparent Km values were unaffected. 4. Immunoprecipitation of the enzyme labelled in vivo with [35S]methionine showed that tunicamycin did not inhibit the synthesis of the enzyme protein per se, nor did it increase the degradation of the enzyme protein. 5. Immunoprecipitation of the enzyme labelled in vitro with [14C]nitromethane showed that tunicamycin did not affect the introduction of the dehydroalanine residue into the active site. 6. These results are consistent with the following hypothesis: tunicamycin inhibits the N-linked glycosylation of phenylalanine ammonia-lyase which, in turn, results in imperfect folding of the enzyme protein. The orientation of the active site is changed in such a way that the affinity of the enzyme for its substrate is unaffected, whereas the catalytic activity of the enzyme is reduced. 7. Both optical- and electron-microscopic immunolocalization studies with antibody to phenylalanine ammonia-lyase showed increased deposition of silver granules in cells in sections of potato discs in which induction of the enzyme was allowed to occur compared with cells from newly wounded tissue. The enzyme was located in the cytoplasm, and was possibly membrane-associated.

Ammonia-Lyases↗
PubMed1990

Methaemoglobinaemia due to accidental sodium nitrite poisoning. Report of 10 cases.

Nitrates and nitrites are widely used in the food and chemical industry. Poisoning with these agents may be potentially life-threatening as a result of the production of methaemoglobin. A group of 10 patients suffering from moderate to severe methaemoglobinaemia after accidental intoxication with a sodium nitrite salt is described. One patient died but the other 9 recovered rapidly. The low mortality rate was attributed to prompt diagnosis and institution of appropriate therapy with methylene blue and ascorbic acid.

Adult↗
PubMed1990

Oxidative activation of the thiophene ring by hepatic enzymes. Hydroxylation and formation of electrophilic metabolites during metabolism of tienilic acid and its isomer by rat liver microsomes.

Tienilic acid (TA) is metabolized by liver microsomes from phenobarbital-treated rats in the presence of NADPH with the major formation of 5-hydroxytienilic acid (5-OHTA) which is derived from the regioselective hydroxylation of the thiophene ring of TA. During this in vitro metabolism of TA, reactive electrophilic intermediates which bind irreversibly to microsomal proteins are formed. 5-Hydroxylation of TA and activation of TA to reactive metabolites which covalently bind to proteins both required intact microsomes, NADPH and O2 and are inhibited by metyrapone and SKF 525A, indicating that they are dependent on monooxygenases using cytochromes P-450. Microsomal oxidation of an isomer of tienilic acid (TAI) bearing the aroyl substituent on position 3 (instead of 2) of the thiophene ring also leads to reactive intermediates able to bind covalently to microsomal proteins. Covalent binding of TAI, as that of TA, depends on cytochrome P-450-dependent monooxygenases and is almost completely inhibited in the presence of sulfur containing nucleophiles such as glutathione, cysteine or cyteamine. These results show that 5-OHTA, which has been reported as the major metabolite of TA in vivo in humans, is formed by liver microsomes by a cytochrome P-450-dependent reaction. They also show that two thiophene derivatives, TA and TAI, bind to microsomal proteins after in vitro metabolic activation, TAI giving a much higher level of covalent binding than TA (about 5-fold higher) and a much higher covalent binding: stable metabolites ratio (4 instead of 0.5).

Animals↗
PubMed1990

24-homologated 1,25-dihydroxyvitamin D3 compounds: separation of calcium and cell differentiation activities.

A series of 24-homologated 1,25-dihydroxyvitamin D3 compounds have been chemically synthesized and studied with regard to their activity in inducing differentiation of human promyelocyte HL-60 cells to monocytes and in calcium mobilizing activity in vitamin D deficient rats. Homologation of 1,25-dihydroxyvitamin D3 or its delta 22 analogue by one or two carbons increases by 10-fold and three-carbon homologation reduces by half the activity in causing differentiation of HL-60. On the other hand, homologation causes a substantial decrease in in vivo calcium mobilization activity. The addition of each carbon at the 24-position decreases binding to the HL-60 receptor or rat intestinal receptor by 5-10-fold so that binding affinity of the trihomo compound for the receptors is 130 times less that of 1,25-dihydroxyvitamin D3. Thus, binding affinity for the receptor cannot account for the preferential activity of the 24-homologated compounds in inducing cell differentiation.

Animals↗
PubMed1990

Intracerebroventricular bethanechol for Alzheimer's disease. Variable dose-related responses.

Five male patients participated in a pilot open-label study of dose-related aspects of response to intracerebroventricular bethanechol in Alzheimer's disease. No patient had remission of symptoms, but three patients improved symptomatically and on tests of memory. Improvement was evident over a restricted range of doses for each subject, and symptoms were worse at doses below and above the optimal range. There was little overlap in the range of doses producing improvement among these three. Two patients had no consistent improvement in memory, and agitation, depression, paranoia, and seizures developed during treatment. Qualitative differences and variability in dosages producing responses complicate the identification of true drug response in the treatment of Alzheimer's disease.

Alzheimer Disease↗
PubMed1990

DNA sequencing in HydroLink matrices: extension of reading ability to greater than 600 nucleotides.

All the systems for optimizing DNA sequencing published so far have introduced modifications regarding: (i) linearization of band migration via ionic strength gradients or wedge-shaped gels; (ii) automatization of band reading via introduction of fluorescent probes; (iii) direct blotting analysis; (iv) pulsed electric fields and (v) discontinuous buffer systems. In all these systems, DNA sequence reading with an accuracy of ca. 98% rarely exceeds a length of 350 bases. We have chosen, in order to increase the reading ability of a single gel, to manipulate the characteristics of the gel matrix. The Seq-HydroLink gel formation here reported allows optimal reading, from a single gel run, of at least 600 bases. In order to guarantee this reading ability in a single run, the upper and lower ends of the ladder are time-resolved, i.e. the same sample is applied to the gel matrix at three different time intervals. The present system represents an increase of at least 30% in reading ability as compared with any type of polyacrylamide gel formulation so far reported.

Bacteriophages↗
PubMed1990

Comparison of assays for prostatic and total acid phosphatase.

Total and tartrate inhibited acid phosphatase was determined on the Technicon Chem 1 and evaluated against a Cobas-Bio centrifugal analysis procedure and an immunochemical method. Precision and reference range studies were performed for the Chem 1 acid phosphatase procedure and correlation was established with the other methods. The Chem 1 method for measuring total and prostatic acid phosphatase is a sensitive method with good correlation to the centrifugal analysis and the immunochemical method. The assay is fully automated and requires no manual off-line sample preparation.

Acid Phosphatase↗
PubMed1990

Characteristics of the memory loss of a patient with Wernicke-Korsakoff's syndrome without alcoholism.

The memory loss in alcoholic Wernicke-Korsakoff syndrome has been well characterized. However, it has been suggested that some of the neuropsychological defects seen in these patients are due to frontal lobe dysfunction resulting from chronic alcohol abuse. The present report details the nature and extent of the amnesia in a Wernicke-Korsakoff patient who did not have a history of alcoholism. In spite of her normal performance on measures of frontal lobe function, this patient showed many characteristics similar to those seen in alcoholic Wernicke-Korsakoff syndrome including a graded loss of remote memories and abnormal semantic information processing. Thus, the extent of the "core" features of this amnesic syndrome may be greater than was previously thought.

Alcohol Amnestic Disorder↗