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Biomedical subjects

D Morgan

Publications and source records attributed to D Morgan.

At least 55 records · Page 3Linked to original sources
PubMed1995

An outbreak of Campylobacter jejuni enteritis associated with failed milk pasteurisation.

This paper describes an outbreak of gastrointestinal illness affecting at least 110 people, of whom 41 had microbiological confirmation of Campylobacter jejuni infection. The outbreak of infection was found to have been associated with consumption of inadequately pasteurised milk from a local dairy. The problem of enforcement of food and safety regulations when milk from dairies fails the phosphatase test is discussed. The prevalence of seroconversion to campylobacter in the community is estimated from a sample of cases and controls involved in this outbreak.

Animals↗
PubMed1995

Successful engraftment using allogeneic peripheral blood progenitor cells in a patient with primary bone marrow graft failure.

G-CSF-mobilized peripheral blood progenitor cells (PBPC) were utilized in a patient who failed to engraft after an unmanipulated HLA-matched allogeneic bone marrow transplant. Marrow engraftment occurred after repeated conditioning with high-dose cyclophosphamide and PBPC infusion. Severe graft-versus-host disease (GVHD) developed shortly after marrow engraftment. The role of PBPC in allogeneic transplant, the associated potential risk of GVHD, and the necessity of reconditioning before stem cell reinfusion are discussed.

Adult↗
PubMed1995

Vibrio cholerae O139 Bengal infections among tourists to Southeast Asia: an intercontinental foodborne outbreak.

To determine the source and extent of an outbreak of Vibrio cholerae O139 Bengal infections among 630 cruise ship passengers to Southeast Asia, a retrospective cohort study was done. Questionnaires were sent to all passengers from the United States, Canada, and the United Kingdom, and serum samples were requested from all passengers reporting diarrhea. A case was defined as diarrheal illness with onset between 8 and 28 February 1994 and a cholera antitoxic antibody titer > or = 800. Six passengers, including 1 with bacteremia, met the case definition. Illness was associated with eating yellow rice at a buffet restaurant in Bangkok on 10 February (relative risk undefined, P = .005). This international outbreak demonstrates foodborne transmission of Vibrio cholerae O139 Bengal, an emerging cause of epidemic cholera in Asia, to tourists from Western countries. Physicians should suspect infection with either V. cholerae O1 or O139 in any patient with severe watery diarrhea after travel to the developing world.

Aged↗
PubMed1995

Noninvasive pulse wave analysis for the early detection of vascular disease.

A noninvasive technique has been developed and validated for calculating capacitive and oscillatory systemic arterial compliance with the use of pulse wave analysis and a modified Windkessel model. Application of the technique to subjects with hypertension, postmenopausal women with symptomatic coronary artery disease, and appropriate control subjects has confirmed a reduction of oscillatory compliance in the disease states and an increase in capacitive and oscillatory compliances in response to vasodilator drugs. This method should be useful in screening subjects for early evidence of vascular disease and in monitoring the response to therapy.

Blood Pressure↗
PubMed1995

Medical confidentiality in the Armed Forces.

The doctor/patient relationship is unique. The doctor's surgery/clinic can be likened to the confessional and the duty of confidence to a patient does not end with the patient's death. It is ongoing. It is accepted that in the Armed Forces, a Commanding Officer can request disclosure of all relevant medical information by his medical officer. The medical officer in this case would need to be guided not only by military law but also by guidelines laid down by the General Medical Council (the GMC 'blue book'). Each case needs to be considered on its own merit. The Medical Defence Union is available to discuss individual cases with its members. (An MDU booklet 'Confidentiality' is available free to members. Application may be made to the Medical Defence Union, 3 Devonshire Place, London W1N 2EA.)

Confidentiality↗
PubMed1994

A case control study of infection with an epidemic strain of multiresistant Salmonella typhimurium DT104 in England and Wales.

Laboratory reports of a multiresistant strain of Salmonella typhimurium definitive type (DT) 104 rose in 1993; this led the Public Health Laboratory Service to investigate cases and identify possible risk factors for infection. Information derived from questionnaires, and details of previous isolations of S. typhimurium DT104 from food and animals, were used to design an unmatched case control study. Eighty-three cases whose isolations were of the same plasmid profile type (the 'epidemic strain') and 235 controls were included in the analysis. Illness was independently associated with the consumption of several food items and contact with animals, particularly ill farm animals. The number of isolations of this organism continues to rise, and control measures may include reducing infection in animals used for food, reducing the risk of contamination at all stages of the food chain, and raising awareness of measures to prevent food poisoning among food handlers and the general public.

Adolescent↗
PubMed1994

Surveillance of HTLV infection in England and Wales: 1986-1992.

The epidemiology of infection with human T cell leukaemia/lymphoma virus (HTLV) types I and II in England and Wales between 1986 and 1992 has been studied. Two sources of data have been reviewed: reports of cases of infection received by the PHLS Communicable Disease Surveillance Centre, and information about people infected with HTLV-I and II provided on laboratory request forms sent to the Virus Reference Division of the PHLS Central Public Health Laboratory. Most patients were of Caribbean origin. The age and sex distribution of people with disease associated with HTLV-I and II in England and Wales resembles that previously recorded in the Caribbean. The data suggest that the prevalence of disease associated with HTLV infection is low in England and Wales, but case ascertainment may be incomplete.

Adult↗
PubMed1994

Local recurrence after simple mastectomy.

A retrospective study was carried out to determine the clinical significance of local recurrence after simple mastectomy and node biopsy for primary operable breast cancer, without postoperative irradiation or systemic adjuvant therapy. Local recurrence was defined as a histologically proven lesion in or deep to the mastectomy skin flaps. A total of 966 patients with a median follow-up of 7 years were reviewed. Of these, 223 (23 per cent) developed local recurrence but half the tumours were small single lesions; 70 women had multiple discrete lesions and 21 diffuse carcinomatous dermal infiltration. Local recurrence showed significant associations with tumour grade, nodal status and the presence of lymphovascular invasion in the primary tumour. A predictive index containing these three variables was constructed. Adjuvant irradiation of the flaps is recommended for patients with high scores; such women would otherwise have a 39 per cent chance of developing local recurrence by 5 years. Different types of local recurrence have different chances of responding to local therapy: 13 per cent of single local recurrences, 32 per cent of multiple spot recurrences and 70 per cent of the diffuse type failed to respond to local therapy. Local recurrence predicts reduced patient survival.

Aged↗
PubMed1994

An outbreak of Campylobacter infection associated with the consumption of unpasteurised milk at a large festival in England.

Seventy-two laboratory confirmed cases of Campylobacter infection were identified in people who attended a large festival in England. A case-control study was undertaken to identify the vehicle of infection. Potential risk factors included the water supply to the site, and food, bottled spring water and unpasteurised milk sold at the event. Only the consumption of unpasteurised milk showed a statistical association with having a Campylobacter infection, strongly suggesting that this was the vehicle of infection.

Adolescent↗
PubMed1994

The role of home-made ice cream as a vehicle of Salmonella enteritidis phage type 4 infection from fresh shell eggs.

A family outbreak of Salmonella enteritidis PT4 infection is described in which home-made ice cream was identified as the vehicle of infection. The ice cream contained approximately 10(5) S. enteritidis PT4 organisms per gm and was probably contaminated by an infected shell egg containing between 10(5)-10(8) organisms. The continued relevance of the Chief Medical Officer's warning on the use of raw shell eggs is highlighted. Home-made ice cream using the same recipe as ice cream that had been incriminated as the cause of the family outbreak of S. enteritidis PT4 infection was used to study the growth of the organism that might have occurred in the 3-4 h it took to prepare the product. When the inoculum was in the stationary phase, as it would be from shell or other cross contamination, there was a lag phase of 3 h before growth occurred at room temperature. Even when actively multiplying organisms were introduced, as may be found in an infected egg, there was less than 3 log(10) increase in the salmonella count in 4 h at room temperature. It was, therefore, given the high S. enteritidis count, unlikely that the ice cream was cross-contaminated. By contrast, raspberry sorbet at pH 3.73 proved to be lethal to a large inoculum of S. enteritidis and may be a relatively safe raw egg containing product.

Animals↗
PubMed1994

Daily variation in step length of trained male runners.

The purpose of this study was to quantify daily intra-individual variability in mean step length, a basic descriptor for the running pattern. Following 60 minutes of treadmill accommodation, nine trained male subjects (X age = 34.2 yrs +/- 7.2, X VO2max = 57.0 +/- 4.8 ml.kg-1.min-1) performed daily (Mon-Fri) 6-minute treadmill runs at three submaximal speeds (2.68, 3.13 and 3.58 m.s-1) over a 4-week period. To minimize extraneous influences, subjects refrained from road racing and completed the 20 running sessions (5 d.wk-1.4 weeks for each speed) at the same time of day and in the same footwear. Treadmill velocity was calibrated for each 6-minute running bout and step length was determined during the last 2 minutes of each run. Results indicated that mean step length and coefficient of variation values were 0.984 m and 2.50% at 2.68 m.s-1, 1.124 m and 2.22% at 3.13 m.s-1, and 1.254 m and 2.26% at 3.58 m.s-1. Reliability analyses indicated that the percentage of variation accounted for in step length across all speeds was high and improved very little as test number increased (range = 96% for two days vs 99% for five days). Taken together, these findings suggest that when testing conditions are controlled, within-subject variability in step length measures obtained at multiple submaximal running speeds is small in trained subjects and that criterion step length values can be obtained by averaging duplicate measurements.

Adult↗
PubMed1994

Effect of step length optimization on the aerobic demand of running.

To assess whether distance runners displaying uneconomical freely chosen step lengths (FCSL) could be trained to shift FCSL toward a more optimal setting, six males and three females who exhibited uneconomical FCSL [mean optimal step length (OSL) = -9.81% of leg length from FCSL; mean change in oxygen uptake (VO2) (FCSL - OSL) = 1.46 ml.kg-1.min-1] comprised an experimental group that completed 15 treadmill sessions (30 min/day, 5 days/wk, 3 wk) of OSL training at individually determined running velocities (2.87-3.74 m/s). Training sessions featured alternating 5-min periods of combined audio and visual feedback matching OSL and no feedback. A control group of three subjects with uneconomical FCSL (2 males, 1 female) performed 3 wk of treadmill running without feedback. The extent of step length optimization was evaluated by comparing pre- and posttraining differences between FCSL and OSL and between pre- and posttraining VO2. Compared with the control group, the experimental group demonstrated a significantly (P < or = 0.05) greater relative shift in FCSL toward OSL and a marked reduction in FCSL VO2. Taken together, these results suggest that short-term audiovisual feedback training can be effective in optimizing step length and producing a decrease in aerobic demand among distance runners exhibiting uneconomical FCSL.

Adult↗
PubMed1994

Up-regulation of the connexin43+ gap junction network in haemopoietic tissue before the growth of stem cells.

The early developmental stages of haemopoiesis are thought to be regulated by paracrine growth factors and by the haemopoietic environment. Are gap junctions involved here? Gap junctions are structures in cell membranes allowing the direct transfer of ions and small molecules between adjacent cells and are known to be involved in development. We have found that although connexin43 gap junctions are rare (0.00016 +/- 0.0002/microns2 tissue) in normal adult mouse marrow their expression is 80-fold higher (0.0292 +/- 0.0147/microns2) in neonatal marrow. One difference between neonatal and adult haemopoietic tissue is that in the latter more haemopoietic cells are dividing. To test if more gap junctions were due to increased division we altered adult blood-formation by mobilizing or destroying end cells--granulocytes and red cells--or by forcing stem cells to divide by making them regenerate an ablated blood-forming system. Mobilizing end cells had no effect on the number or distribution of gap junctions in marrow but forced stem cell division caused a 100-fold increase in gap junction expression and did so before any recognizable haemopoietic cells formed. There were greater than normal numbers of gap junctions in radio-protected adult mouse marrow. The cells coupled by gap junctions are TE-7+ mesodermally derived fibroblasts, STRO-1+ stromal cells, and CD45+ and CD34+ haemopoietic cells. We propose that there is a latent network of Cx43+ gap junctions in normal quiescent marrow. In response to events that call for active division of stem cells this network is amplified and coupled to haemopoietic stem cells, perhaps enabling them to divide.

Animals↗
PubMed1994

Restoration of differentiation and suppression of tumorigenicity in somatic cell hybrids of human squamous carcinoma cells and keratinocytes.

Somatic cell hybrid cell lines derived from the fusion of human squamous carcinoma cells (FaDu-Hyg) with human keratinocytes were used to examine the relationships between cell differentiation and tumorigenicity. Treatment of the parental keratinocytes or the two hybrid cell lines with the combination of calcium and fetal bovine serum increased the expression of the envelope precursor, involucrin, 4- to 8-fold, whereas it remained unchanged in FaDu-Hyg cells. Similarly, calcium- and serum-treated keratinocytes and the two hybrid cell lines displayed a 7- to 13-fold increase of the activity of membrane-associated type I transglutaminase, whereas transglutaminase activity in FaDu-Hyg cells did not change appreciably. FaDu-Hyg cells were tumorigenic in vivo, but tumorigenicity was suppressed in both hybrid cell lines. Analysis of additional tumor cell lines indicated that the expression of transglutaminase I and involucrin are under separate genetic control and that loss of transglutaminase activity can result either from a lack of protein or from a defect in the activation step. Thus, keratinization of squamous epithelial cells appears to be controlled by several different recessive genes, which cosegregate with but are probably only partly identical with the genes that suppress tumor formation in vivo.

Animals↗