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Biomedical subjects

R Paul

Publications and source records attributed to R Paul.

At least 163 records · Page 9Linked to original sources
PubMed1991

Additional mapping of mouse chromosome 2 genes.

The purpose of this work was to elucidate the genetic fine structure of the central portion of mouse chromosome (Chr) 2. Seven Chr 2 congenic mouse strains [B10.PA(L)-pa we un at, B10.PA(L)-pa Aw, B10.PA(L)-we un at, B10.PA(J)-pa a, B10.FS-we Aw, B10.C-we Aw, and B10.YBR-a] were produced. Breeding studies were carried out using strains B10.PA(L)-pa we un at and B10.LP-H-13b to accurately determine the recombination frequencies between marker genes pa and we (1.9% +/- 0.3), we and un (8.8% +/- 0.5), and un and at (4.5% +/- 0.4) of strain B10.PA(L)-pa we un at. These strains and other Chr 2 congenic strains were typed for immunologically defined loci using monoclonal antibody (mAb) C23 reactive with the gene product of B2mb T-lymphocyte clone C1 reactive with the gene product of H-3a and H-3c, and lymphocyte clone H1.8 reactive with the gene product of Hd-1a. B2m and H-3 typing located a recombinational event separating [pa B2m H-3] from we (the order of bracketed genes is not known). Hd-1 typing indicated that Hd-1 maps distal to [H-42, H-44] and proximal to un. The gene order [pa, B2m, H-3], we, [H-42, H-45], Hd-1, un, H-13, at, with H-44 mapping centromeric to Hd-1, is indicated by the data.

Animals↗
PubMed1991

The "whisker sign" as an indicator of ochronosis in skeletal scintigraphy.

A patient with alkaptonuria and ochronotic arthrosis was imaged twice with technetium-99m dicarboxypropane diphosphonate (99mTc-DPD)--once during a bout of arthritic knee pain and once when symptom-free. There was a marked accumulation of radioactivity in the large joints. During the episode of arthritis the knee joints had a higher uptake than when the patient was without symptoms. The intervertebral discs showed a high uptake which extended laterally from the axial vertebral column; the finding gave an impression of whiskers, and this "whisker sign" may be characteristic of ochronosis.

Alkaptonuria↗
PubMed1991

Determination of 2-fluoro-2-deoxy-D-glucose uptake and ATP level for evaluating drug effects in neoplastic cells.

The glucose analogue 2-fluoro-2-deoxy-D-glucose (FDG) was used to study chemosensitivity of two human ovarian cancer cell lines and of murine L1210 cells. Cell viability was determined by measuring intracellular adenosine triphosphate (ATP) with a bioluminescence method, which has been shown to correlate closely with trypan blue, stem cell, and [3H]TdR assays. All three cell lines were sensitive to cytostatic drugs, which exerted a parallel decrease in the intracellular FDG and ATP levels. The two measures correlated positively (r = 0.66, P less than 0.001), indicating that FDG uptake is closely linked with ATP production. Relatively low hexokinase (HK)-to-glucose 6-phosphatase (HK/G6-Pase) ratios were measured, which suggests that the metabolic trapping of FDG 6-phosphate within the cytosol is incomplete. Apparently, these cell lines may not depend exclusively on glycolysis for their energy requirement. We conclude that cell killing caused by cytostatic drugs is associated with a decreased ATP content and FDG uptake. This indicates that not only ATP but also FDG may be used to study drug effects in vitro.

Adenosine Triphosphate↗
PubMed1991

Radiation effects on uptake of 99Tcm-hexamethylpropylen amine oxime (HMPAO) in head and neck tumours.

Twenty patients with malignant head and neck tumours were imaged with 99Tcm-labelled hexamethylpropylene amine oxime (HMPAO), a radiopharmaceutical generally used for blood flow studies. Before radiotherapy (RT), 93% of the tumours could be detected with single photon emission computed tomography (SPECT) and 45% with planar imaging. Whole tumour-to-background 99TcmHMPAO uptake ratios ranged from 3.6 to 1.0 (mean 1.7 +/- 0.6) in untreated tumours. There was a good correlation between tumour volume and uptake (r = 0.69, P = 0.002). Sixteen patients were reimaged during or shortly after radical RT. 99TcmHMPAO uptake was significantly lower after treatment (mean uptake ratio 1.2 +/- 0.3, P less than 0.001). However, RT associated changes in 99TcmHMPAO uptake were in agreement with the clinical response in only 63% of the studies. This study indicates that 99TcmHMPAO SPECT imaging can be used for pretherapeutic localisation of head and neck tumours. Although most tumours show a decrease in uptake after irradiation the poor association with tumour regression does not allow for reliable assessment of treatment response.

Adult↗
PubMed1991

Communication and socialization skills at ages 2 and 3 in "late-talking" young children.

Twenty-one apparently normal children between 18 and 34 months of age with slow expressive language acquisition were compared to a group of normally speaking children matched for age, SES, and sex ratio, on the Vineland Adaptive Behavior Scales (Sparrow, Balla, & Cicchetti, 1984). The late talkers (LTs) scored significantly lower not only in expressive communication, but also in receptive communication and socialization. A follow-up study of the same subjects, seen at age 3, showed nearly half the 3-year-olds with a history of LT remained delayed in expressive communication and socialization, while one third remained behind in receptive language. The data suggest that social skills are particularly vulnerable to disruption in children with late expressive language development, even after communication skills have moved into the normal range. They suggest, further, that receptive deficits do not seem, in themselves, to increase the risk of continued language delay. Clinical implications of these findings are discussed.

Child Language↗
PubMed1991

Maternal linguistic input to toddlers with slow expressive language development.

Maternal speech styles to children between 20 and 34 months of age who were slow to acquire expressive language were compared to those of mothers with normally speaking toddlers. Aspects of the mothers' speech examined included use of various sentence types (declaratives, negative, questions, etc.); the mother's lexical contingency with regard to the child's utterance; mother's use of pragmatic functions such as requests, comments, and conversational devices; and the mother's use of topic management. Results revealed that mothers of toddlers with slow language development are different from mothers of normal speakers only in their frequency of use of lexical contingency devices, specifically, expansion and extension. However, the proportion of expansions and extensions relative to the number of child utterances is not different, indicating that when late talkers give their mothers something to expand, the mothers do so, but that the late talkers do not give their mothers as much speech to work with as do the normal toddlers. Implications of these findings for parent training are discussed.

Child, Preschool↗
PubMed1991

[99Tcm]MAG3 gamma camera nephrography in epidemic nephritis.

There is a lack of systematic nephrographic studies on epidemic nephritis (EN). We studied 10 patients with EN using [99Tcm]MAG3 gamma camera nephrography and followed up 9 of them 22-68 days later when they had clinically recovered. Variables for renal clearance of [99Tcm]MAG3 and the retention of radioactivity in the kidneys and blood were calculated. In all patients renal function was impaired acutely. There was marked reconstitution of renal function in the control studies. [99Tcm]MAG3 clearance was inversely related to serum creatinine. On visual inspection the nephrograms showed no focal changes. Nephrography was more sensitive than sonography at identifying renal impairment. [99Tcm]MAG3 nephrography is a sensitive method for identifying renal involvement and reconstitution of renal function in EN. It may be a valuable adjunct to the diagnostic arsenal, especially in nonendemic areas where EN occurs only sporadically and where there may be diagnostic uncertainty in patients presenting acutely with EN.

Disease Outbreaks↗
PubMed1991

The Sfpi-1 proviral integration site of Friend erythroleukemia encodes the ets-related transcription factor Pu.1.

Previous studies identified a common site (Sfpi-1) for proviral integration in immortalized Friend erythroleukemias. cDNAs corresponding to a 1.5-kb Sfpi-1 mRNA were isolated and sequenced. These were larger than an independently isolated Sfpi-1 cDNA described by researchers from another laboratory, and they contained common differences from that sequence, including in the coding region four extra nucleotides that altered the reading frame. The properly translated protein is identical to Pu.1, a transcription activation factor that is related to the ets oncogene family. Genetic methods were used to map Sfpi-1 with respect to other loci on mouse chromosome 2. Our results suggest that Pu.1 blocks erythroblast differentiation and thereby causes immortalization.

Amino Acid Sequence↗
PubMed1991

Plasma membrane receptors for ecotropic murine retroviruses require a limiting accessory factor.

A retroviral vector was used to express various amounts of the receptor (ecoR) for ecotropic host range murine retroviruses on naturally barren hamster, mink, and human cells. These cells and murine cells were then incubated for 2 h with dilutions of a helper-free ecotropic retrovirus that encodes human growth hormone, and the number of infected cells was later determined by growth hormone-specific immunofluorescence. For all cells under the conditions of these studies, virus adsorption was the limiting step of infection and the cellular capacities for infection were unsaturated either at cell surfaces or at intracellular sites. Thus, infections occurred at low multiplicities of infection per cell and were directly proportional to virus and cell concentrations, and only a small percentage (ca. 5%) of the infectious virions became adsorbed from the medium during the 2-h incubations. Although increasing the adsorption by raising virus or cell concentrations results in more infections in the cultures, increasing adsorption by raising the number of ecoR above a low threshold had no effect on infections. Thus, cells with a low number of ecoR were infected as efficiently as highly adsorbing cells that contained many times more ecoR. To reconcile these results, we conclude that only a small, set number of cell surface ecoR can be functional for infection and that all excess ecoR can only bind virus into an unsalvageable pool. Therefore, retroviral receptors on single cells are functionally diverse. Our results suggest that activity of ecoR in infection requires a limiting second cellular component.

3T3 Cells↗
PubMed1991

A health situation analysis in Trinidad and Tobago, 1990. The local health systems approach.

This HSA exercise confirmed known patterns of health and disease in Trinidad and Tobago but produced valuable new information on health status, particularly as it relates to the different local health administrative areas. This was perhaps the most valuable aspect of the analysis. We cannot overemphasize the need for disaggregated data as summary statistics often mask the true state of affairs. This report has focussed on the health status of the population and emphasized again the dominant role of chronic non-communicable diseases and accidents as causes of death. Among males, aged 15-44 years, AIDS was the third leading cause of death in 1987, and can be expected to become even more important as a cause of death over the next few years. Other and equally important information on the status of the health information system and the health services situation was also produced and will be discussed elsewhere.

Accidents↗
PubMed1991

[Lead exposure of workers in various areas of a battery production establishment].

The aim of the investigation was the examination of the significance of exposure test results with respect to lead exposure of workers, which are exposed to temporal strongly varying levels of exposure. The clinical parameters delta-aminolaevolinic acid (DALS), lead concentration in blood (BPb) and erythrocyteprotoporphyrin (EPP) were examined. For the medical praxis the EPP is best suited for the estimation of the individual exposure risk over longer periods of time under mentioned conditions of exposure.

Adult↗
PubMed1990

Preparation of triazolo[1,5-c]pyrimidines as potential antiasthma agents.

With the use of the human basophil histamine release assay, 5-aryl-2-amino[1,2,4]triazolo[1,5-c]pyrimidines were found to be active as mediator release inhibitors. These compounds were prepared by reacting arylamidines with sodium ethyl formylacetate or with ethyl propiolate to give pyrimidinones. Treatment with phosphorus oxychloride gave a chloropyrimidine, which was converted to a hydrazinopyrimidine with hydrazine. Cyclization, using cyanogen bromide, gave the triazolo[1,5-c]pyrimidines, after a Dimroth rearrangement. Following a structure-activity evaluation, the 5-[3-(trifluoromethyl)phenyl]-2-amino (8-10), 5-(3-bromophenyl)-2-amino (8-13), 5-[3-(difluoromethoxy)-phenyl]-2-amino (8-11), and 5-(4-pyridinyl)-2-amino (6-7) compounds were found to have the best activity. They were chosen for further pharmacological and toxicological study.

Animals↗
PubMed1990

Skeletal scintigraphy in coeliac disease.

A patient with undiagnosed, long-standing coeliac disease had multiple hot spots on skeletal scintigraphy, similar to those observed in malignant disease metastatic to the skeleton. A gluten-free diet corrected the pathological laboratory values, and a repeat skeletal scintigram 15 months after the first one was normal. It is important to identify the secondary hyperparathyroidism of coeliac disease as a cause of multiple hot spots in skeletal scintigraphy--the finding resembles malignancy, but is due to a benign, curable condition.

Adult↗
PubMed1990

Plesiomonas shigelloides bacteremia in a healthy girl with mild gastroenteritis.

A previously healthy 15-year-old girl fell ill with febrile gastroenteritis; Plesiomonas shigelloides was isolated from the blood 6 h after she had received one tablet of trimethoprim-sulfadiazine on the third day of symptoms. She recovered uneventfully. P. shigelloides may be isolated from the blood in immunocompetent patients with mild, uncomplicated gastroenteritis.

Adolescent↗