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Biomedical subjects

D Morgan

Publications and source records attributed to D Morgan.

At least 145 records · Page 8Linked to original sources
PubMed1996

Development of minimally differentiated acute myeloblastic leukemia with novel isochromosome 18p and antecedent aplastic anemia.

We describe a case of acute myeloblastic leukemia with a novel isochromosome 18, i(18)(p10), preceded by aplastic anemia for six months. The patient is a cotton grower chronically exposed to pesticides. The significance of this chromosomal abnormality is unknown. The possible relationship to the preceding history of aplastic anemia and occupational pesticide exposure is speculated on. The possible mechanism of the association of acute leukemia and aplastic anemia is discussed.

Agricultural Workers' Diseases↗
PubMed1996

Salmonella virchow PT 26 infection in England and Wales: a case control study investigating an increase in cases during 1994.

An increase in the number of human isolates of Salmonella virchow phage type (PT) 26 in England and Wales during 1994 was investigated. A national case control study was conducted which included 88 cases and 182 controls. The cases were mostly young adults (median age 26) and 13 (15%) were admitted to hospital. Acquisition of S. virchow PT 26 was associated with the consumption of any chicken (OR 2.5, CI 1.1-5.8), of chicken curry from restaurants and take aways (OR 2.9, CI 1.4-6.1), and of some other diverse types of pre-prepared chicken (OR 3.8, CI 1.9-7.6). Halal chicken was associated (P = 0.006) with illness in a subset. There were negative associations with contact with animals (OR 0.47, CI 0.23-0.95) and with the consumption of chicken cooked whole (OR 0.37, CI 0.21-0.66). The increase in S. virchow PT 26 may be due to changing epizoology and may be an indicator of what will become the dominant salmonella strain in poultry in future years. The increasing incidence of S. virchow PT 26 is of particular concern because of its association with more invasive disease in humans.

Adolescent↗
PubMed1996

X-linked anhidrotic (hypohidrotic) ectodermal dysplasia is caused by mutation in a novel transmembrane protein.

Ectodermal dysplasias comprise over 150 syndromes of unknown pathogenesis. X-linked anhidrotic ectodermal dysplasia (EDA) is characterized by abnormal hair, teeth and sweat glands. We now describe the positional cloning of the gene mutated in EDA. Two exons, separated by a 200-kilobase intron, encode a predicted 135-residue transmembrane protein. The gene is disrupted in six patients with X;autosome translocations or submicroscopic deletions; nine patients had point mutations. The gene is expressed in keratinocytes, hair follicles, and sweat glands, and in other adult and fetal tissues. The predicted EDA protein may belong to a novel class with a role in epithelial-mesenchymal signalling.

Adult↗
PubMed1996

Perception of emotion from dynamic point-light displays represented in dance.

It is well known that biological motion, as produced by point-light displays on a human body, gives a good representation of the represented body-eg its gender and the nature of the task which it is engaged in. The question is whether it is possible to judge the emotional state of a human body from motion information alone. An ability to make this kind of judgment may imply that people are able to perceive emotion from patterns of movement without having to compute the detailed shape first. Subjects were shown brief video clips of two trained dancers (one male, one female). The dancers were aiming to convey the following emotions: fear, anger, grief, joy, surprise, and disgust. The video clips portrayed fully lit scenes and point-light scenes, with thirteen small points of light attached to the body of each dancer. Half the stimuli were presented the right way up, while half were inverted. The subjects' task was to judge which emotion was being portrayed. Full-body clips gave good recognition of emotionality (88% correct), but the results for upright biological-motion displays were also significantly above chance (63% correct). Inversion of the display reduced biological-motion (but not full-body) performance to close to chance but still significantly above chance. A space-time analysis of the motion of the points of light was carried out, and was related to the discriminability of the different emotions. Biological-motion displays, which convey no information while static, are able to give a rich description of the subject matter, including the ability to judge emotional state. This ability is disrupted when the image is inverted.

Analysis of Variance↗
PubMed1996

High cellular concentration of peripheral blood progenitor cells during cryopreservation adversely affects CFU-GM but not hematopoietic recovery.

The effects of bone marrow (BM) and peripheral blood progenitor (PBPC) concentration during cryopreservation on subsequent hematopoietic engraftment following high-dose chemotherapy were studied in 24 patients. Seventeen BM harvests and 71 PBPC collections were performed between July 1991 and June 1994. The PBPC were frozen at significantly higher cellular concentrations than the BM (medians of 243 x 10(6)/ml versus 73 x 10(6)/ml respectively, p = 0.0003). The recovery of committed progenitor cell colonies (CFU-GM) was significantly lower from PBPC frozen at concentrations above the median, compared with 116% from those frozen at concentrations below the median (p = 0.0467). This phenomenon was not seen in BM, which was generally frozen at a threefold lower concentrations. Despite the lower recovery of CFU-GM when PBPC were frozen at a higher concentration, the patients receiving these grafts achieved good hematopoietic recovery. The higher number of PBPC probably compensated for the loss, and the patients still received a substantial number of clonogenic hematopoietic precursors.

Adolescent↗
PubMed1996

Acute hemodynamic and neurohoromonal effects of furosemide in critically ill pediatrics patients.

OBJECTIVES: To study the acute hemodynamic effects of furosemide in critically ill pediatrics patients, the temporal relationship between hemodynamic changes and changes in neuroendocrine axis, and the temporal relationship between hemodynamic changes and urine output. DESIGN: Prospective study. SETTING: Pediatric intensive care unit in a tertiary care university center. PATIENTS: Fourteen critically ill pediatric patients who clinically required diuretic therapy. INTERVENTIONS: Before and after furosemide administration, hemodynamic and neurohormonal measurements were taken. MEASUREMENTS AND MAIN RESULTS: Hemodynamic and neurohormonal responses to acute diuretic therapy were measured in 14 pediatric patients treated with furosemide (1 mg/kg/dose). Cardiac index deteriorated by 10 mins after drug administration (-9.4+/-3.9%, p<.05) and was associated with an increase in systemic vascular resistance (17.1+/-4.8%, p<.05). There was a subsequent increase in cardiac index (20+/-4.9%, p<.05) at 30 mins, with a decrease in systemic vascular resistance (-11.5+/-5.2%, p<.05). These hemodynamic changes were associated with marked increases in renin and norepinephrine concentrations and an increase in urinary prostaglandin release. The hemodynamic and neurohormonal effects had their onset before maximum diuresis. CONCLUSION: Intravenous furosemide administration in acutely ill pediatric patients results in an acute but transient deterioration in cardiac function that appears to parallel the neuroendocrine changes rather than the acute diuresis.

Adolescent↗
PubMed1996

Respect for autonomy: is it always paramount?

Following the argument proposed by Tschudin in 1986 that many nurses do not have the skills for ethical decision-making, this article identifies and discusses one ethical problem from practice. The problem concerns an extremely obese patient who refuses to be moved by a hoist. The nurse acquiesce to the patient's wishes and she is moved manually by four members of staff. The issues identified for discussion are: the paramountcy of the principle of respect for the patient's autonomy; the rights and obligations of the nurses; and the justification for influencing patient choice. The approach used by the ward nurses is analysed and the value of using an ethical decision-making model is considered.

Aged↗
PubMed1995

Radiation dose-response of human tumors.

PURPOSE: The dose of radiation that locally controls human tumors treated electively or for gross disease is rarely well defined. These doses can be useful in understanding the dose requirements of novel therapies featuring inhomogeneous dosimetry and in an adjuvant setting. The goal of this study was to compute the dose of radiation that locally controls 50% (TCD50) of tumors in human subjects. METHODS AND MATERIALS: Logit regression was used with data collected from single institutions or from combinations of local control data accumulated from several institutions treating the same disease. RESULTS: 90 dose response curves were calculated; 62 of macroscopic tumor therapy, 28 of elective therapy with surgery for primary control. The mean and median TCD50 for gross disease were 50.0 and 51.9 Gy, respectively. The mean and median TCD50 for microscopic disease control were 39.3 and 37.9 Gy, respectively. At the TCD50, an additional dose of 1 Gy controlled an additional 2.5% (median) additional patients with macroscopic disease and 4.2% (median) additional patients with microscopic disease. For both macro- and microscopic disease, an increase of 1% of dose at the TCD50 increased control rates approximately 1% (median) or 2-3% (mean). A predominance of dose response curves had shallow slopes accounting for the discrepancy between mean and median values. CONCLUSION: Doses to control microscopic disease are approximately 12 Gy less than that required to control macroscopic disease, and are about 79% of the dose required to control macroscopic disease. The percentage increase in cures expected for a 1% increase in dose is similar for macroscopic microscopic disease, with a median value of approximately 1%/% and a mean of approximately 2.7%/%.

Dose-Response Relationship, Radiation↗
PubMed1995

Waterborne cryptosporidiosis associated with a borehole supply.

From 1 April to 31 May 1993, 64 cases of cryptosporidiosis were diagnosed within one district health authority. Forty were classified as primary cases, 35 of whom were clustered in an area supplied by a discrete public water supply that supplied the majority of homes in a large town. Most of the water in this supply is abstracted from boreholes and some is filtered before distribution. Households that received mains water from this supply were 15 times more likely to be affected than households nearby that received water from other sources. A case control study demonstrated a dose response relationship between consumption of water obtained from the town supply and risk of illness. Very low concentrations of cryptosporidial oocysts were detected in the water supply on four occasions several weeks after the outbreak. Environmental investigation failed to reveal a likely mechanism for contamination of the water supply.

Adolescent↗
PubMed1995

Role of ornithine decarboxylase in epidermal tumorigenesis.

Ornithine decarboxylase (ODC) plays a key role in the biosynthesis of polyamines, which are necessary for cell growth and differentiation. ODC expression is very tightly controlled in all normal cells; however, regulation of its expression is altered in many tumor cells resulting in much higher basal levels of ODC in tumors. To investigate the potential role of ODC overexpression in epidermal tumorigenesis, we constructed a replication-defective retroviral vector to overexpress a truncated ODC protein in epidermal cells. Stable viral infection of mouse epidermal cells dramatically increases not only the basal ODC activity but also the basal putrescine and spermidine levels. In all infected epidermal cells with high polyamine levels, DNA synthesis is increased as measured by [3H]thymidine incorporation into DNA as well as increased bromodeoxyuridine staining in the nuclei of ODC-infected epidermal cells. ODC viral infection of nontumorigenic BK-1 epidermal cells and primary cultures of mouse keratinocytes and fibroblasts from newborn mouse skin yields no tumors when injected s.c. into athymic nude mice or when transplanted as skin grafts onto nude mice. Epidermal cell lines SP-1 and 308 (which possess an activated rasHa gene) are not tumorigenic when injected s.c. into nude mice. However, following infection with the ODC virus, they form tumors filled with keratin and papilloma-like projections of hyperplastic epidermal cells displaying dysplasia and many mitotic figures. These data indicate that ODC overexpression by itself is not sufficient to induce tumors in normal cells but that increased expression of ODC enhances tumor development in initiated premalignant epidermal cells.

9,10-Dimethyl-1,2-benzanthracene↗
PubMed1995

Discriminative stimulus effects of the 5HT1A agonist 8-OH-DPAT: attenuation by mu but not by kappa opioids.

The ability of mu and kappa opioids to alter the discriminative-stimulus and rate-decreasing effects of the 5-HT1A receptor agonist 8-OH-DPAT was examined in rats trained to discriminate either a low (0.1 mg/kg) or a high (0.3 mg/kg) dose of 8-OH-DPAT from water using a two-lever food-reinforced drug discrimination procedure. The mu opioids, morphine and fentanyl, and the kappa opioids, U50,488 and bremazocine, failed to substitute for the 8-OH-DPAT stimulus, even when tested up to doses that substantially reduced rates of responding. During antagonism tests, selected doses of the mu opioids, morphine and fentanyl, administered at various pretreatment times, attenuated the stimulus effects of both training doses of 8-OH-DPAT. Moreover, morphine (135-min pretreat) and fentanyl (15-min pretreat) produced rightward shifts in the 8-OH-DPAT dose-effect curve that were partially surmountable and naltrexone-reversible. In contrast to the effects of the mu opioids, the kappa opioids, U50,488 and bremazocine, failed to alter the stimulus effects of the training dose of 8-OH-DPAT, regardless of dose or pretreatment time. The rate-decreasing effects of 8-OH-DPAT were not altered substantially by either the mu or kappa opioids examined. The present study demonstrates that the stimulus effects, but not the rate-decreasing effects, of 5-HT1A receptor agonists can be modulated by mu opioids, whereas neither of these effects are changed by kappa opioids.

3,4-Dichloro-N-methyl-N-(2-(1-pyrrolidinyl)-cycloh↗
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↗