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Biomedical subjects

J Deutsch

Publications and source records attributed to J Deutsch.

At least 19 recordsLinked to original sources
PubMed1992

Electron-impact and chemical ionization detection of nicotine and cotinine by gas chromatography-mass spectrometry in rat plasma and brain.

Nicotine and its metabolite, cotinine, were measured in rat plasma and brain by gas chromatography-mass spectrometry. Both agents were extracted from plasma and brain, separated on a capillary column, and quantified by single-ion monitoring. The major fragment ions of nicotine and cotinine at m/z 84 and m/z 98, respectively, were monitored by electron-impact ionization detection and the protonated molecular ions at m/z 163 and m/z 177, respectively, were monitored by chemical ionization detection. Both compounds were quantified using deuterium-labeled nicotine and cotinine, respectively, as internal standards.

Animals↗
PubMed1992

Red cell aplasia responsive to immunoglobulin therapy as initial manifestation of human immunodeficiency virus infection.

A patient who presented with pure red cell aplasia as the initial manifestation of human immunodeficiency infection is described. The patient had no signs of other autoimmune processes or immunologic or histologic evidence of parvovirus B19 infection, although we detected parvovirus B19 DNA in his serum. This patient had a complete, although temporary, response to a single course of immunoglobulin therapy and is currently responding to a second treatment.

Adult↗
PubMed1992

Removal of scleral explant elements: a 10-year retrospective study.

There are several studies in the American literature on the incidence and causes of retinal redetachment following removal of explants. This is, to our knowledge, the first such study from Britain and differs in its findings from the American experience. The reason for removal of explants, the time of removal after initial detachment surgery and the consequences of removal were reviewed for the 10-year period from 1980 to 1990. During this period 1898 retinal detachment operations were performed at this centre, with an explant removal rate of 3.2% (61 eyes). Extrusion of the element was the cause in 74%. Of these 8% subsequently suffered a redetachment. In two eyes no retinal break was identified at initial surgery. Both of these suffered a redetachment following removal of the explant. Contrary to previous reports, redetachment was not related to short periods of explant or to infection of the explant. This study suggests that explant removal is a safe procedure. However, there is a significant risk of redetachment after explant removal if no breaks are identified at the time of initial surgery.

Adolescent↗
PubMed1992

Myxoma mix-up. A case report.

We present a 63-year-old lady who had atrial myxoma. The diagnostic difficulties distinguishing this from giant cell arteritis are highlighted. In particular, both conditions caused choroidal and retinal infarcts, anterior ischaemic optic neuropathy, with raised acute phase reactants. The authors stress the importance of continued ophthalmoscopy as the fundal changes become more apparent.

Diagnosis, Differential↗
PubMed1991

Eyelid leishmaniasis in a patient with neurogenic ptosis.

A patient with chronic progressive external ophthalmoplegia contracted cutaneous leishmaniasis of the upper eyelid. Infection of this site is rare because eyelid movements usually prevent the sandfly vector from biting the skin there. It is postulated that the relative immobility of the upper eyelid in this patient was a major predisposing factor for the infection.

Antimony Sodium Gluconate↗
PubMed1991

Identification of 11,13-dihydroxy-14-octadecaenoic acid as a circulating Na+/K(+)-ATPase inhibitor.

Two digitalis-like compounds (DLC) were purified to homogeneity from bovine plasma. The purification procedure consisted of organic extractions and batch chromatography followed by three subsequent separations using reverse-phase high-performance liquid chromatography. The presence of a DLC in the different fractions was monitored by their ability to inhibit (a) [3H]ouabain binding to rat brain synaptosomes, and (b) microsomal Na+/K(+)-ATPase activity. Using mass spectrometry and nuclear magnetic resonance spectroscopy the structure of one of the DLCs was identified as 11,13-dihydroxy-14-octadecaenoic acid. It is suggested that this new hydroxy, unsaturated, fatty acid derivative may regulate Na+/K(+)-ATPase activity under some physiological and pathological conditions.

Animals↗
PubMed1990

Electron-impact ionization detection of scopolamine by gas chromatography-mass spectrometry in rat plasma and brain.

Scopolamine, a muscarinic receptor antagonist, was measured in rat plasma and brain using gas chromatography-mass spectrometry with electron-impact ionization detection. Extracted scopolamine was either directly derivatized or first hydrolyzed to scopine, then derivatized with heptafluorobutyric anhydride, separated on a capillary column and quantified by mass fragmentography. Electron-impact ionization produced a common fragment peak at m/z 138 that was monitored along with trideuterated scopolamine, an internal standard (m/z 141). The method can be used to measure scopolamine concentrations of 2 ng/ml in rat plasma and 20 ng/g in rat brain.

Animals↗
PubMed1990

Brain and plasma pharmacokinetics and anticancer activities of cyclophosphamide and phosphoramide mustard in the rat.

By a sensitive and quantitative fluorometric assay, brain and plasma time-dependent concentration profiles were generated for phosphoramide mustard (PM) and active alkylating metabolites derived from cyclophosphamide (CPA) administration to rats. Whereas PM rapidly disappeared from plasma, with a monophasic half-life of 15.1 min, equimolar administration of CPA generated active metabolites in plasma that disappeared monoexponentially, with a composite half-life of 63 min. As a consequence, the time-dependent concentration integral of active alkylating metabolites derived from CPA administration, calculated between 5 min and infinity, was 3-fold that of PM. Pharmacokinetic parameters were calculated for each compound. The brain/plasma concentration-integral ratios of PM and active alkylating metabolites derived from CPA were 0.18 and 0.20, respectively. The cerebrovascular permeability-surface area product of PM was 7.5 x 10(-5) s-1, which is similar to that of other water-soluble anticancer agents that are restricted from entering the brain. The activities of a range of daily doses of PM and CPA were assessed against subcutaneous and intracerebral implants of Walker 256 carcinosarcoma tumor in rats. Inhibition of subcutaneous tumor growth by 50% was caused by CPA and PM doses of 6.6 and 12.0 mg/kg (daily for 5 consecutive days, starting 36 h after tumor implantation), respectively. However, administration of daily doses of up to 40 mg/kg did not significantly increase the survival of animals with intracerebral tumor implants. These studies indicate that active metabolites of CPA are restricted from entering the brain and that only subtherapeutic concentrations are achieved in brain tissue after systemic administration of CPA or PM.

Animals↗
PubMed1990

Photorefraction: two methods and their clinical applications.

Photorefraction is an increasingly used research screening tool and numerous studies have demonstrated the simple and effective techniques available. This article describes the eccentric (off axis) and isotropic methods in detail, including the costs and difficulties involved. It is likely that photorefractive screening will become more widespread in its use as a screening tool in detecting the early factors responsible and associated with delayed visual maturation in the very young and that hospital departments of medical illustration may have to become conversant with the use of this new tool.

Amblyopia↗
PubMed1989

Larval fat body-specific gene expression in D. melanogaster.

The Pl gene, together with the LSP-1 alpha, -1 beta, and -1 gamma, LSP-2, and P6 genes, is expressed exclusively in the larval fat body of D. melanogaster during the third instar. In vivo mapping of the cis-acting regulatory sequences of the P1 gene was carried out using hybrid constructs with three different reporter genes and a combination of transient and germline transformation assays. This revealed that regulatory elements involved in the setting up of the temporal and spatial specificities of transcription of the P1 gene are located in a short DNA region immediately upstream of the mRNA transcription start. This region includes an element that behaves as a fat-body transcriptional enhancer and element(s) required for ecdysone inducibility of transcription of the P1 gene.

Animals↗
PubMed1989

A trial of RIT-4237 rotavirus vaccine in 1-month-old infants.

In a double blind placebo-controlled study rotavirus vaccine RIT 4237 was offered to young infants after the fourth week of life. The vaccine was very well tolerated. Fifty-seven out of 100 vaccine recipients and 10 out of 103 placebo recipients developed rotavirus-IgM-antibodies during the 1 month follow-up period. During a 6 month follow-up, stool samples from 2 out of 12 vaccinees and from 5 out of 12 placebo recipients contained rotavirus.

Antibody Formation↗
PubMed1989

Sperm antibodies in vasectomized men and their effects on fertilization.

Sera (vbs, n = 25) and seminal plasma (vsp, n = 21) from vasectomized men (n = 25) were analyzed for cross-reaction with lithium diiodosalicylate (LIS)-solubilized human sperm extract, protamine, and fertilization antigen (FA-1) with an enzyme-linked immunosorbent assay (ELISA). Among the vbs tested, 44% reacted with human sperm extract, 28% reacted with protamine, and 44% reacted with FA-1 for at least one class of antibodies (IgG, IgA, or IgM). In contrast to the sera, the seminal plasma showed minimal reactions. Neither the vbs nor vsp were found to contain immune complexes, indicating that the antibodies were present in free form. Vasectomized sera that reacted with FA-1 showed a significant (p less than 0.0001) inhibition of human sperm penetration of zona-free hamster ova. The immunoabsorption of FA-1-positive sera with purified FA-1 significantly increased the penetration rates. Affinity-purified human immunoglobulins reactive with FA-1 and not those reactive with protamine reduced sperm penetration rates. Thus, antibodies in vbs reactive with FA-1 are relevant to infertility, causing an inhibition of fertilization. These data will have clinical relevance for diagnosis and treatment of infertility after successful vasovasostomy.

Adult↗
PubMed1989

Studies on covalent binding of (-)trans-7,8-dihydroxy-7,8-dihydrobenzo[a]pyrene metabolites to cytochromes P-450 LM2 and LM4 and NADPH-cytochrome P-450 reductase.

1. Metabolism of 14C-labelled benzo[a]pyrene (-)trans-7,8-dihydrodiol to protein- and DNA-binding products in a reconstituted enzyme system proceeds 5 to 10 times faster with rabbit cytochrome P-450 LM4 than with LM2. 2. Either cytochrome converts the substrate to ethyl acetate- and water-soluble metabolites, identified by h.p.l.c. Water-soluble metabolites comprise 78% of the total products with cytochrome P-450 LM2, but only 50% of those formed by LM4. The relative proportion of the two types of metabolites is differentially affected by certain modifiers such as 7,8-benzoflavone. 3. Half of the radioactivity in the aqueous phase of reaction mixtures containing cytochrome P-450 LM4 represents (-)trans-7,8-diol metabolites in complex primarily with NADPH and phosphate. The remaining water-soluble products are bound covalently to proteins in the reconstituted system. 4. Polyacrylamide gel electrophoresis, autoradiography, and measurement of the radioactivity in individual bands indicate that a larger fraction of metabolites is bound to cytochrome P-450 LM4 than to NADPH-cytochrome P-450 reductase, and only marginal binding to cytochrome P-450 LM2 is seen. Metabolite binding to added DNA is likewise substantially greater in magnitude when cytochrome P-450 LM4, as opposed to LM2, catalyses (-)trans-7,8-diol oxygenation. Thus, the degree of metabolite binding to monoxygenase proteins and to DNA correlates well with the catalytic activity of cytochrome P-450 LM4 and LM2 towards (-)trans-7,8-diol. 5. DNA causes a dramatic enhancement in the activity of cytochrome P-450 LM4 with (-)trans-7,8-diol, indicating that the cytochrome and/or the reductase may be functionally impaired by metabolites of this substrate. Such an effect may alter the balance between detoxication and activation of the carcinogenic benzo[a]pyrene.

Animals↗
PubMed1988

Investigation of field desorption mass spectral behaviour of prostaglandins for their determination in biological fluids.

Field desorption (FD) mass spectrometry was applied to the determination of prostaglandin E2 (PGE2) in urine. Studies on synthetic compounds showed that methyl esters are stable under FD mass spectrometric conditions. The ester of PGE2 gives rise to protonated molecular ions and fragments due to the elimination of water and the side chains C8H14O and C8H12O2. This behaviour enabled its determination in the nanogram per millilitre range.

Dinoprostone↗
PubMed1988

Detection of specific beta-globin mutations in Kurdish Jews with beta-thalassemia.

Patients with beta-thalassemia, of Kurdish extraction, were screened for the presence of two mutations, in the TATA box and in codon 44, previously discovered in this ethnic isolate. Of the 56 chromosomes analyzed, 13 were found to carry the TATA box mutation and 17 the codon 44 mutation. The result of this work provides a basis for a more efficient prenatal diagnosis program for this community.

Adolescent↗
PubMed1987

[Value of cholescintigraphy in the differential diagnosis of direct hyperbilirubinemia in infancy].

Cholescintigraphy using 99mTc-diethyl-, 99mTc-diisopropyl-, 99mTc-iodo-diethyl- and 99mTc-bro-motrimethyl-IDA was performed in 22 newborns and infants with direct hyperbilirubinaemia. Retrospective evaluation of 99mTc-diethyl- and 99mTc-diisopropyl-IDA (n = 18) showed an efficiency of 66% in the differentiation between extrahepatic biliary atresia and neonatal intrahepatic diseases if the hepatocyte-clearance index and transit time were taken into consideration; the sensitivity of detecting extrahepatic biliary atresia was 100%. Cholestyramine treatment (n = 9) did not increase the efficiency of the test. Efficiency was markedly reduced when the serum direct bilirubin level was above 5.5 mg/dl (94 mumol/l). The gall bladder was not visualized in 13 out of 18 examinations. The prospective and retrospective analysis of 99mTc-iodo-diethyl- and 99mTc-bromo-trimethyl-IDA revealed intrahepatic disease in all 6 infants with serum values up to 12.6 mg/dl (216 mumol/l) direct bilirubin; the gall bladder was not visualized in 4 out of 7 examinations.

Biliary Atresia↗
PubMed1987

[Liver diseases in children and their relatives with homozygous and heterozygous alpha 1-antitrypsin deficiency].

Over a 6-year period 26 infants and children with homozygous (2 Z and 6 ZZ) or heterozygous alpha 1-antitrypsin deficiency (12 MZ, 6 MS) were observed prospectively and their families investigated. 7 of 8 homozygous patients had neonatal hepatitis, whereby 3 of these showed maximum transferase activities during the 5th to 9th months of life. At the age of 7 years 2 of these patients were clinically normal, but only one patient had normal transferases. One patient had cirrhosis with portal hypertension at the age of 16 years 6 months; her nephew showed hypersplenism. Family studies revealed a further 5 relatives of phenotype Z, 16 of phenotype MZ, 3 of phenotype SZ and 1 of phenotype MS; 6 of these had slightly elevated serum transferase activities. 6 patients of phenotype MZ and 2 patients of phenotype MS had neonatal hepatitis but generally with a much better prognosis than in homozygous patients. The other heterozygous patients (6 MZ and 4 MS) had a variety of additional factors determining the disease and the prognosis. Family studies showed a further 7 family members of phenotype MZ, and 2 of phenotype MS; 2 of these had slightly elevated transferase activities, 3 parents had hereditary hyperbilirubinaemia.

Adolescent↗