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J Alt

Publications and source records attributed to J Alt.

At least 19 recordsLinked to original sources
PubMed2004

Interleukin-1beta stimulates growth hormone-releasing hormone receptor mRNA expression in the rat hypothalamus in vitro and in vivo.

Changes in growth hormone-releasing hormone (GHRH), GHRH-receptor (R), somatostatin and interleukin (IL)-1beta mRNA levels were determined in fetal rat hypothalamic cultures after administration of IL-1beta (1, 10, 100 ng/ml, 2 h incubation), and in adult rat hypothalamus 5 h after intracerebroventricular injection of IL-1beta (2.5 and 25 ng). IL-1beta stimulated GHRH-R mRNA expression both in vitro (10 and 100 ng/ml) and in vivo (2.5 and 25 ng). Somatostatin mRNA was significantly stimulated and GHRH mRNA slightly reduced in vitro, while these mRNA species were not altered in vivo in response to IL-1beta. IL-1beta stimulated its own expression both in vitro (10 and 100 ng/ml) and in vivo (25 ng). IL-1beta-induced mRNA responses occurred 2 h after treatment in vitro (incubation times, 30 min to 6 h). IL-1beta also elicited slight GHRH releases in vitro. Up-regulation of hypothalamic GHRH-R by IL-1beta may explain previous findings suggesting that IL-1beta stimulates GHRH activity.

Animals↗
PubMed2001

Influence of photoperiod on N-acetyltransferase activity and melatonin in the fiddler crab Uca pugilator.

Melatonin and N-acetyltransferase (NAT) activity were measured in the eyestalks of fiddler crabs acclimated to various photoperiods: constant light, a L:D 12:12 h photoperiod, or constant dark. Following acclimation, eyestalks were collected every 3 h over a 24-h period; they were assayed for melatonin with a radioimmunoassay and for NAT activity with a radioenzymatic assay. In constant light, melatonin levels increased at 1300 h, from 142 to 431 pg x mg(-1) eyestalk; NAT activity increased concurrently, from 97 to 203 pmol x h(-1) x mg(-1) eyestalk, and both remained elevated until 0400 h. In the L:D 12:12 h photoperiod, melatonin levels increased at 1300 h from 28 to 230 pg x mg(-1) eyestalk, and though NAT activity increased significantly, from 80 to 122 pmol x h(-1) x mg(-1) eyestalk, an even greater increase occurred at 0400 h, when melatonin levels were low. In constant dark, melatonin levels increased at 1600 h, from 22 to 196 pg x mg(-1) eyestalk, with a concurrent increase in NAT activity from 93 to 140 pmol x mg(-1) x h(-1) eyestalk. However, the second peak in melatonin (111 pg x mg(-1)), occurring at 0400 h, was out of phase with the second peak of NAT activity (113 pmol x mg(-1) x h(-1) eyestalk) which occurred at 0700 h. NAT may be a rate-limiting step in melatonin synthesis in fiddler crabs under some conditions (constant light and the 1300 h peak in constant dark); however, NAT activity correlates poorly with melatonin levels in a L:D 12:12 h photoperiod and in constant dark relative to the 0400 h melatonin peak.

Animals↗
PubMed2001

[Value of endoanal sonography in the assessment of faecal incontinence].

PURPOSE: The aim of this study was to assess the value of endoanal ultrasound (EUS) in comparison to anal manometry and operative findings in patients suffering from faecal incontinence. Patient history, localisation of sphincter defects and therapeutic modalities were analysed. METHODS: Over a 3-years period, 92 patients with faecal incontinence were investigated by endoanal ultrasound. Results were compared with anal manometry in 81 cases. RESULTS: At EUS, 27 patients (29 %) showed no sphincter defect, 18 (20 %) had an isolated internal sphincter defect, 13 (14 %) an isolated defect of the external sphincter and 34 (37 %) presented with a combined internal/external sphincter defect. Manometry correlated in 30 % with endoanal ultrasound. Compared with surgery, endoanal ultrasound was correct in 100 % and manometry in only 54 %. An obstetric trauma was most frequently related to faecal incontinence. CONCLUSION: Endoanal ultrasound is a very sensitive method for localizing anal sphincter defects and is mandatory in the assessment of patients with faecal incontinence.

Adult↗
PubMed1995

HIV test counselling at a tertiary hospital.

A questionnaire was distributed to 64 of the 78 interns working at a teaching hospital in Cape Town in August 1992 to examine their attitudes and practice in respect of HIV test counselling. The questionnaire was completed by 61 interns. Thirteen per cent of those who responded counselled all patients, 49% counselled some patients and 38% counselled no patients. Thirty-four per cent stated that they felt that pre-test counselling was always necessary and 57% that post-test counselling was always necessary. The most frequently stated reasons for not counselling patients were language barriers, time constraints, feelings of incompetence on the part of the intern and the fact that the patient was too ill. It is recommended that standard counselling procedures be established in each ward and formal under- and postgraduate counselling training for medical students and interns be instituted.

Adult↗
PubMed1986

Spinach plastid genes coding for initiation factor IF-1, ribosomal protein S11 and RNA polymerase alpha-subunit.

The nucleotide sequence of 2.5 kbp from the cloned SalI fragments 8 and 11 of spinach plastid DNA has been determined. This region was found to encode three open reading frames for hydrophilic polypeptides of 77, 138, and 335 amino acids. Using the computer search algorithm of Lipman and Pearson (Science 227, 1435, 1985), these genes were identified as coding for homologues of E. coli initiation factor IF-1 (inFA), 30S ribosomal protein S11 (rps11), and the alpha-subunit of DNA-dependent RNA polymerase (rpoA). The spinach plastid gene organization is inFA - 381 bp spacer - rps11 - 72 bp spacer - rpoA. The genes are transcribed in vivo and appear to encode functional proteins. These findings imply that plastid chromosomes code for components of the organelle transcription apparatus.

Amino Acid Sequence↗
PubMed1983

Genes and transcripts for the polypeptides of the cytochrome b6/f complex from spinach thylakoid membranes.

Cytochrome b6/f complex was prepared from washed thylakoid membranes by a procedure involving detergent treatment and centrifugation in sucrose gradients. The complex is composed of at least four polypeptide species, cytochrome f which occurs in two variant forms (mol. wt. 34/33 kd), cytochrome b6 (23 kd), the high-potential Rieske iron-sulfur protein (19 kd) and a fourth subunit (17 kd) of unknown function. Transcripts for the cytochromes f, b6 and subunit 4 were found in plastid RNA, those for the Rieske iron-sulfur protein in cytosolic poly(A) RNA. Transcripts for cytochrome b6 and subunit 4 are translated in rabbit reticulocyte lysates into products of correct length. The Rieske iron-sulfur protein and the cytochrome f apoprotein appear to be made as precursors with excess sequences of 7 and 4 kd, respectively. Cytochrome f, cytochrome b6 and subunit 4 are encoded by uninterrupted plastid genes that are located in the large single-copy region of the circular DNA molecule. Each of these genes is present once per chromosome. Their location and direction of transcription have been determined by hybrid-selection mapping and by cell-free transcription/translation of various recombinant DNAs. The genes for cytochrome b6 and for subunit 4 lie near each other, but do not overlap. They are transcribed into a single message. The gene for cytochrome f maps 15 kbp away from this cluster, close to the 3' end of the gene for the large subunit of ribulosebisphosphate carboxylase/oxygenase, and is transcribed into a separate 4 kb long RNA. All these genes have the same polarities with respect to each other.

Journal Article↗
PubMed1983

Localization of the genes for the two chlorophyll a-conjugated polypeptides (mol. wt. 51 and 44 kd) of the photosystem II reaction center on the spinach plastid chromosome.

A core particle of the water-oxidizing photosystem II reaction center has been prepared from stacked spinach thylakoid membranes by a procedure involving extraction with the non-ionic detergent dodecyl-beta-D-maltoside and centrifugation in sucrose gradients. The protein-pigment complex consists of at least four polypeptide species: two components with mol. wts. of 51 and 44 kd which are conjugated with chlorophyll a and beta-carotene, the herbicide-binding protein of mol. wt. 32 kd and cytochrome b 559 (11 kd). The genes for the 51-and 44-kd polypeptides have been located on the circular 150-kbp spinach plastid chromosome. They were identified by hybrid-selection mapping, in vitro transcription-translation of recombinant DNAs and specific antisera which were used to characterize the translation products. The plastid chromosome carries one uninterrupted copy for each of these genes in its large single-copy region. The gene for the 51-kd protein (which probably bears the P(680) reaction center chlorophyll a) is located in close proximity to the gene for cytochrome b6, and some 70 kbp away from the gene for the ;32-kd' herbicide-binding protein of the reducing side of photosystem II. The gene for the 44-kd protein is situated halfway between these two genes adjacent to the gene for the P(700) chlorophyll a apoprotein of the photosystem I reaction center. Both photosystem II genes are transcribed into discrete RNA species in the same direction but from the opposite strand as the gene for the ;32-kd' protein.

Journal Article↗
PubMed1982

We bit the bullet.

Explore the source record for details and available documents.

Nursing Service, Hospital↗
PubMed1975

Characterization of an inducible amidase from Pseudomonas acidovorans AE1.

The main molecular and catalytic properties of an acetanilide-hydrolyzing enzyme from Pseudomonas acidovorans AE 1, purified to a homogeneous state, were investigated. The molecular weight was 57 500 as determined by gel filtration and 55 300 as computed from the amino acid composition. By polyacrylamide gel electrophoresis in dodecylsulfate a polypeptide chain weight of 56 700 was obtained. Based on the reaction of the highly purufied enzyme with diethyl-4-nitrophenyl phosphate an equivalent weight of approximately 59 100 was found. From these results it was concluded that the enzyme consists of a single polypeptide chain and contains one active site per molecule. The enzyme hydrolyzed esters as well as certain aromatic amides. It also catalysed the transfer of acetyl groups to phenetidine yielding phenacetin. The activities towards aliphatic esters were much smaller. The enzyme was stable at pH values ranging from 7 to 9 and its pH-optimum was about 10. It was strongly inhibited by organophosphorous compounds, like diethyl-4-nitrophenyl phosphate or diisopropylphosphorofluoridate, as well as by physostigmine sulfate and -SH-blocking reagents, like HgCl-2 or 4-chloromercuribenzoic acid. o-Nitrophenol caused a competitive inhibition and phenetidine an uncompetitive inhibition.

Acetanilides↗
PubMed1975

Isolation of an inducible amidase from Pseudomonas acidovorans AE1.

A bacterial strain, AEI, which hydrolysed acetanilide, was isolated from soil and identified as Pseudomonas acidovorans. Numerous amides, esters and enzyme inhibitors were tested as amidase inducers. Phenacetin was chosen as inducer for the large scale cultivation of these organisms because it was less toxic to the bacteria than acetanilide. The induction increased the enzymic activity 250-fold. In comparison, the type culture strain of P. acidovorans, ATTCCI5668, had no amidase activity which could be induced by phenacetin. Optimal growth conditions were established with respect to the concentration of carbon source and inducer so that about 10% of the extractable bacterial protein consisted of the amidase. The organisms were lysed with lysozyme in the presence of EDTA and the enzyme was isolated mainly by column chromatography procedures. A preparation form 60 g (wet wt) bacteria yielded about 100 mg highly purified amidase with a specific activity of 137 mugmol substrate hydrolysed/min/mg protien. In addition to acetanilide, the purified enzyme hydrolysed several other amides and esters. As standard substrate, p-nitroacetanilide was chosen.

Acetamides↗