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Biomedical subjects

M Jones

Publications and source records attributed to M Jones.

At least 577 records · Page 32Linked to original sources
PubMed1992

Changing patterns of malaria in south-east Scotland: implications for practitioner awareness and prophylactic advice.

The medical records of all 229 patients with malaria admitted to the Edinburgh City Hospital between 1969 and 1988 were studied retrospectively. A total of 137 were from Africa, 44 from the Indian subcontinent, 19 from the Far East, 18 from New Guinea, 5 from the Middle East and 3 from South America. The number of yearly admissions rose markedly after 1983, mainly due to an increase in Plasmodium falciparum cases. Ninety-four cases (15 with severe parasitaemia) mainly from Kenya and Nigeria were due to P. falciparum infection and 99 to P. vivax. There were no deaths. A seasonal distribution of onset of fever in patients with P. vivax infections originating from the Indian subcontinent showed that most patients presented during the summer. Prophylaxis had generally been irregular or non-existent but many compliant patients may have been receiving an inadequate dose of chloroquine on a mg/kg body weight basis. General practitioners are likely to see at least one case of malaria every 4 years. They are encouraged to seek advice from a specialist unit whenever necessary whether before or after their patient travels abroad. Travellers, in particular to Kenya and Nigeria, and Asian immigrants to the UK returning on holiday to their country of origin should be strongly advised to take regular prophylaxis including on return to the UK.

Adolescent↗
PubMed1992

Contamination of flexible fiberoptic bronchoscopes with Mycobacterium chelonae linked to an automated bronchoscope disinfection machine.

Between December 5, 1989, and September 25, 1990, Mycobacterium chelonae was isolated from endoscopic or bronchial washings in 14 patients on a single clinical service. A phenotypically unique strain of M. chelonae subspecies abscessus that was highly resistant to cefoxitin (MIC greater than 256 micrograms/ml) and different from 13 control isolates of M. chelonae recovered elsewhere in the hospital was identified in all these patients and the rinse water from the bronchoscope disinfecting machine. None of the outbreak patients had evidence of invasive M. chelonae disease. Aggressive infection control measures on the disinfecting machine, including use of sterile water in the wash and rinse cycles, increasing the 2% alkaline glutaraldehyde exposure time, frequent replacement of the glutaraldehyde, and disinfection of the machine, failed to eradicate the M. chelonae, presumably because of the presence of a biofilm inside the machine. Rinsing the scopes with 70% alcohol after automated disinfection eliminated the outbreak strain. This study demonstrates that automated bronchoscope disinfecting machines may become heavily contaminated with mycobacteria that resist usual disinfection, resulting in a source of bronchoscope contamination.

Bronchoscopes↗
PubMed1992

Endotoxin enhancement of lymphocyte adherence to cultured sheep lung microvascular endothelial cells.

The most common predisposing factor for development of the adult respiratory distress syndrome is gram-negative sepsis. Our previous studies have shown that a single infusion of Escherichia coli endotoxin into sheep causes early sequestration of lymphocytes in the lungs' microcirculation. In this report, we examined the effects of endotoxin on sheep lymphocyte adherence to sheep pulmonary microvascular endothelial cells in vitro. Endothelial cells were exposed to endotoxin, and subsequent adherence of 51Cr-labeled lymphocytes was measured in a monolayer adhesion assay. Endotoxin enhanced adherence of lymphocytes isolated from blood and caudal mediastinal node (CMN) lymph in a time- and dose-dependent manner. Adherence of CMN lymphocytes increased from a control value of 13.6 +/- 1.6% to 29.9 +/- 3.1% after 4 h of treatment with 1 microgram/ml endotoxin. Both B and T lymphocytes contributed to the increased adherence. Pretreatment of the endothelial cells with cycloheximide revealed that the endotoxin-enhanced adherence was partially dependent upon protein synthesis. Morphologic studies revealed that enhanced adherence was accompanied by a 5-fold increase in migration of lymphocytes between endothelial cells. In contrast to human umbilical vein endothelial cells, antibodies to the known lymphocyte adherence molecules, lymphocyte function-associated antigen (LFA-1), CD-44, and the lymphocyte homing receptor (LECAM-1), were ineffective in blocking adherence to the sheep pulmonary endothelial cells. We conclude that the acute sequestration of lymphocytes in the pulmonary microcirculation of sheep after endotoxin administration is due to increased adhesive properties of the endothelial cells. Our data suggest that this adherence is mediated by as yet undescribed mechanisms that may be unique to pulmonary microvascular endothelium.

Animals↗
PubMed1992

How much do junior staff influence patient throughput in a surgical unit?

A study was undertaken of inpatient throughput in a surgical department on a 'split site' District General Hospital. The study compared the individual contribution of equally qualified and experienced surgical registrars working at both sites. The results show that one registrar was associated with a statistically significant higher patient throughput, which appeared to be the result of a more expeditious approach to patient management. There was no evidence of an accompanying reduction in the quality of care delivered. The additional throughput amounted to approximately 300 extra patients in two years, and made a substantial contribution to the surgical workload in the District.

Bed Occupancy↗
PubMed1992

High-resolution mapping of the X-linked hypohidrotic ectodermal dysplasia (EDA) locus.

The X-linked hypohidrotic ectodermal dysplasia (EDA) locus has been previously localized to the subchromosomal region Xq11-q21.1. We have extended our previous linkage studies and analyzed linkage between the EDA locus and 10 marker loci, including five new loci, in 41 families. Four of the marker loci showed no recombination with the EDA locus, and six other loci were also linked to the EDA locus with recombination fractions of .009-.075. Multipoint analyses gave support to the placement of the PGK1P1 locus proximal to the EDA locus and the DXS453 and PGK1 loci distal to EDA. Further ordering of the loci could be inferred from a human/rodent somatic cell hybrid derived from an affected female with EDA and an X;9 translocation and from studies of an affected male with EDA and a submicroscopic deletion. Three of the proximal marker loci, which showed no recombination with the EDA locus, when used in combination, were informative in 92% of females. The closely linked flanking polymorphic loci DXS339 and DXS453 had heterozygosities of 72% and 76%, respectively, and when used jointly, they were doubly informative in 52% of females. The human DXS732 locus was defined by a conserved mouse probe pcos169E/4 (DXCrc169 locus) that cosegregates with the mouse tabby (Ta) locus, a potential homologue to the EDA locus. The absence of recombination between EDA and the DXS732 locus lends support to the hypothesis that the DXCrc169 locus in the mouse and the DXS732 locus in humans may contain candidate sequences for the Ta and EDA genes, respectively.

Base Sequence↗
PubMed1992

Effects of amino acid dialysate on appetite in CAPD patients.

The use of amino acid (AA) dialysate in CAPD patients may have theoretical disadvantages, since protein ingestion is known to suppress food intake in humans disproportionately to its energy value. Therefore we measured subjective appetite and food intake of CAPD patients in a cross-over study of 16 subjects (age 22-75 years, BMI 19-31, > 3 months on CAPD, non-diabetic and not protein malnourished). They received, in random order, either 4 weeks of dextrose only (their usual treatment), or one AA (1%) exchange replacing the first dextrose exchange each day. Subjective measurements of food intake (3 day food record) and quantitative measurements of lunch time food intake were obtained during a morning dextrose exchange after 28 days of each regimen. Except for a reduction in feelings of fullness during the AA treatment, there were no effects on feelings of hunger/satiety, food appeal, lunch-time food intake, or on 3-day food intake. We conclude that the use of a daily AA (1%) dialysate for 4 weeks does not affect subjective appetite or food intake of CAPD patients. There may even be a beneficial effect as the feeling of fullness decreased with the AA treatment.

Adult↗
PubMed1992

Comparison of modulation transfer function and through focus response with monofocal and bifocal IOLs.

We analyzed modulation transfer function (MTF) and through focus response (TFR) of the TRUE VISTA bifocal IOL and monofocal IOLs and compared the experimental and clinical data. MTF and TFR were measured at different pupil sizes (2, 3, 4 mm), base powers (14, 21, 27 D), add powers (2, 3, 4 D), and distance zone diameters (1.25, 1.5, 1.75 mm). Standards were established to correlate MTF and contrast sensitivity, as well as TFR and the defocus curve measured clinically. MTF of TRUE VISTA decreased with increasing pupil size and base power. A near add of 4 D showed the best MTF at distant and near focus. MTF of TRUE VISTA at near focus was lower than at distant focus and MTF at distant focus was lower than MTF of monofocal IOLs. TFR and the defocus curve correlated closely. MTF and contrast sensitivity of TRUE VISTA at far and near focus also correlated closely. MTF and contrast sensitivity of monofocal IOLs and TRUE VISTA at distant focus did not correlate. MTF was considerably better with monofocal IOLs while contrast sensitivity was slightly better only at low contrast. However, MTF of monofocal IOLs was much higher than MTF of a normal eye while MTF of TRUE VISTA at distant focus was only slightly lower than the MTF of a normal eye. Using MTF of a normal eye as a threshold, our results demonstrated a close correlation between experimental and clinical findings. MTF and TFR may therefore reliably predict the performance of bifocal IOLs.

Contrast Sensitivity↗
PubMed1992

A monocyte/macrophage antigen recognized by the four antibodies GHI/61, Ber-MAC3, Ki-M8 and SM4.

A new monoclonal antibody, GHI/61, which labels the majority of monocytes and tissue macrophages is described. This antibody recognizes an intracellular antigen of 130,000 MW (reduced) and 110,000 MW (unreduced). Using biochemical, flow cytometry and immunocytochemical studies antibody GHI/61 was shown to recognize the same antigen as the previously described antibodies Ber-MAC3, Ki-M8 and SM4. On the basis of the results obtained, antibodies GHI/61, SM4, Ber-MAC3 and Ki-M8 should form a new CD group at the next Leucocyte Typing Workshop. Since the antigen recognized by the antibody GHI/61 is relatively easy to purify, the sequencing and the isolation of the gene encoding this protein should be possible.

Antibodies, Monoclonal↗
PubMed1992

Balanced translocation (14;20) in a mentally handicapped child with cystinuria.

A mentally handicapped 3 year old child with cystinuria is presented. Routine chromosomal analysis showed an apparently balanced de novo translocation in the child with breakpoints 14q22 and 20p13. Family studies suggested that the child is a type I/type II compound heterozygote for cystinuria. This translocation may indicate a possible locus for the gene for cystinuria.

Child, Preschool↗
PubMed1991

Twenty five years of case finding and audit in a socially deprived community.

OBJECTIVE: To evaluate audit and case finding (whole population care) in a community over 25 years. DESIGN: Contemporary screening for and audits of care of chronic disease and risk factors; retrospective review of computerised practice records; and comparisons of mortality and social indices with neighbouring communities. SETTING: One general practice in Glyncorrwg, West Glamorgan. SUBJECTS: 1800 people registered with the practice in 1987 and 558 people who died from 1964 to 1987, whose records had been retained. MAIN OUTCOME MEASURES: Detection of high blood pressure, smoking, airways obstruction, obesity, diabetes, and alcohol problems in adults aged 20-79; prevalence of smoking in this population and in hypertensive and diabetic groups; age standardised mortality ratios in relation to indices of social deprivation. RESULTS: In the population aged 20-79 (1207 patients) 249 (21%) had peak expiratory flow rate less than 50% of expected value or which improved by 15% or more with an inhaled beta agonist, 207 (17%) had body mass index at or over 30 kg/m2, 118 (10%) had untreated mean arterial pressures greater than 159/104 mm Hg (three readings), 80 (7%) (65 (16%) men, 15 (4%) women) had recognised alcohol problems, and 35 (3%) had diabetes. The proportion of men aged 20-64 who said they smoked fell from 61% (290/476) in 1968-70 to 36% (162/456) in 1985 whereas that of women who smoked was unchanged (43%, 187/436 v 42%, 190/448 respectively). In 116 screened hypertensive patients group mean blood pressure fell from 186/110 mm Hg before treatment to 146/84 mm Hg at 1987 audit, as did the proportion of smokers (56% v 20%), but body mass index and total cholesterol concentration showed no significant change. In 34 diabetic patients mean blood pressure and the proportion of smokers fell (171/93 mm Hg v 155/81 mm Hg; 44% v 12%). The age standardised mortality ratio in 1981-6 was lower than in a neighbouring village without a developed case finding programme (actual to expected deaths less than 65 = 21 to 22 in Glyncorrwg, 48 to 30 in control village). CONCLUSIONS: Whole population care through organised case finding and audit is feasible but only with a labour intensive approach combining accessibility, flexibility, and continuity, as well as a planned and structured approach, which requires substantial expansion of staff numbers and assiduous recording. It may reduce risks for at least some high risk groups. Despite their shortcomings the available data are consistent with the hypothesis that whole population care helps reduce mortality. Incentives in the new contract, which encourage the uncritical development of structured process, may diminish health outputs.

Adult↗
PubMed1991

Phorbol esters down-regulate transcription and translation of the CD4 gene.

This study investigated the effects of PMA on biosynthesis and transcription of the CD4 molecule and gene in order to define mechanisms resulting in reduced cell surface expression of the CD4 molecule after treatment with PMA. Cells treated with PMA showed reduced biosynthesis of the CD4 molecule but not of class I HLA molecules. Furthermore, PMA treatment resulted in reduced steady-state levels of CD4 mRNA and inhibition of the relative rate of transcription of the CD4 gene. Cells expressing transfected CD4 cDNA gene products modulated in response to PMA, however, re-expressed CD4 earlier than cells expressing the product of the wild-type CD4 gene. These data suggest that the cell surface expression of the CD4 molecule is probably down-regulated at the level of the protein, as well as the gene, and that inhibition of transcription may affect the kinetics of CD4 expression. These observations provide further insight into the mechanisms by which HIV affects expression of CD4.

Actins↗
PubMed1991

Common mechanisms of retinal regeneration in the larval frog and embryonic chick.

Amphibians and embryonic chicks possess the ability to regenerate retinal neurons by the transdifferentiation of pigment epithelium into neuronal progenitors. Recent studies have begun to identify the molecular factors involved in this process. Laminin (a component of the extracellular matrix) has been shown to be important in the process of retinal regeneration in the larval frog both in vitro and in vivo and basic fibroblast growth factor (bFGF) stimulates the same process in chicks in vivo. To determine the mechanisms by which these factors induce retinal regeneration we studied their effects on cultured chick pigment epithelium cells. bFGF was added to enzymically dissociated chick embryo pigment epithelial cells plated at several different densities on various substrates including laminin. We found that bFGF stimulated proliferation but although the cells lost pigmentation and demonstrated distinct morphological changes, no definitive transdifferentiation could be demonstrated using several neuron-specific antibodies as markers. When the pigment epithelium was cultured as aggregates on a shaker device which prevented flattening and spreading on the substrate a large number of retinal progenitor cells were generated from the pigment epithelium treated with bFGF. The ability of chick pigment epithelium to undergo transdifferentiation thus appears to be dependent on the physical configuration of the cells.

Animals↗