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Biomedical subjects

S Davies

Publications and source records attributed to S Davies.

At least 235 records · Page 13Linked to original sources
PubMed1994

Ataque de nervios and panic disorder.

OBJECTIVE: Ataque de nervios ("attack of nerves") is an illness category used frequently by Hispanic individuals to describe one or more particular symptom complexes. A review of the literature on ataque suggested some overlap with panic disorder. This study investigated the overlap with panic disorder as well as other DSM-III-R axis I disorders. METHOD: Hispanic subjects seeking treatment at an anxiety disorders clinic (N = 156) were assessed with a specially designed questionnaire for self-report of ataque de nervios and panic symptoms and with structured or semistructured psychiatric interviews for axis I disorders. RESULTS: Seventy percent of the subjects reported at least one ataque de nervios; 80% of these were female, whereas 57% of the group without these attacks were female. There were no differences in DSM-III-R diagnoses between the groups with and without ataque de nervios. Ataque was frequently associated with one or more anxiety and affective disorders, including panic disorder, generalized anxiety disorder, recurrent major depression, and anxiety not otherwise specified. Of the 45 subjects with both ataque de nervios and primary panic disorder, 80% appeared to have labeled panic disorder as ataque. Ataque de nervios was associated with panic symptoms even in subjects without panic disorder, but the self-reporting of ataque conveyed additional clinical information about the subjects with panic disorder. Ataque de nervios was similar in frequency and symptoms among subjects of Dominican and Puerto Rican origin. CONCLUSIONS: Ataque de nervios overlaps with panic disorder but is a more inclusive construct. Further study of its interrelation with axis I disorders is needed.

Adult↗
PubMed1994

An immunomagnetic separation method using superparamagnetic (MACS) beads for large-scale purification of human mammary luminal and myoepithelial cells.

A comparison has been made between different immunomagnetic techniques for separating normal human mammary epithelial cells based on the exclusive expression of EMA (epithelial membrane antigen) by luminal cells and CALLA (CD10) by myoepithelial cells. When cells labelled with antibodies to these antigens were incubated with Dynabeads, they rosetted myoepithelial but not luminal cells. However, both luminal and myoepithelial cells could be positively separated using the MACS system. Purity was established by analyzing the expression of CALLA and EMA using flow cytometry, and of cell-type specific cytokeratins using indirect immunofluorescence. Dynabead-separated myoepithelial cell populations were of high purity (> 98%) but the beads could not be removed from the cells. Luminal cell populations separated by the MACS method were also highly purified (> 95%), as were myoepithelial cell populations (> 90%). Using this immunomagnetic separation method, up to 10(7) cells of each type could be obtained from individual preparations.

Adolescent↗
PubMed1994

Bone marrow transplantation for chronic myelogenous leukemia: clinical outcomes.

Marrow transplant is potentially curative therapy for CML. Allogeneic sibling-donor marrow transplant may be the therapy of choice for younger patients early in the course of disease. Early transplant is an important influence on disease-free survival and relapse after related-donor transplant therapy, although additional patient characteristics influencing outcome can be identified and may have cumulative adverse effects. The 5-year disease-free survival of patients transplanted within one year of diagnosis and without signs of advanced disease is greater than 65%. Significant problems remain, however, including early mortality (primarily from infection, pneumonia, and pneumonitis) and relapse of CML following transplant, including late relapse occurring more than 5 years posttransplant. For patients without a matched, related donor, unrelated-donor marrow transplant may be a treatment option and can result in successful outcome for patients with CML. Relapse following unrelated-donor marrow transplant is rare. However, the use of an unrelated donor is associated with significant toxicity, including early mortality, engraftment failure, and ongoing morbidity and mortality associated with acute and chronic graft-versus-host disease. For patients who lack an available matched-related or -unrelated donor, autologous marrow transplant has been developed as an alternative approach to therapy. Long-term survival following autologous marrow transplant is possible and may even approach the survival for allogeneic related-donor recipients, although cure of disease is not achieved.

Actuarial Analysis↗
PubMed1994

Red cell magnesium and glutathione peroxidase in infertile women--effects of oral supplementation with magnesium and selenium.

Six women with a history of unexplained infertility or early miscarriage and who had failed to normalize their red cell magnesium (RBC-Mg) levels after four months of oral magnesium supplementation (600 mg/day) were investigated for red cell glutathione peroxidase activity (RBC-GSH-Px) and were compared with six age-matched women with a history of unexplained infertility or miscarriage who did normalize their RBC-Mg levels on magnesium supplementation. The six non-normalizers had significantly lower (P < 0.0001) RBC-GSH-Px levels than the six normalizers. After a further two months of 200 micrograms daily oral selenium as selenomethionine and oral magnesium supplements, all six women normalized their RBC-Mg (P < 0.0001) and RBC-GSH-Px (P < 0.0001) levels. All 12 previously infertile women have produced normal healthy babies all conceiving within eight months of normalizing their RBC-Mg levels. The possible relevance of these findings to the medical treatment of infertility is discussed.

Abortion, Spontaneous↗
PubMed1993

Prognostic factors and long-term survival in endometrial adenocarcinoma with cervical involvement.

The clinical, surgical, and histopathologic data from 202 patients with endometrial adenocarcinoma with cervical involvement are presented. One hundred fifty-one (75%) had histopathologically confirmed cervical involvement at the time of their definitive surgery, while in 51 (25%) no cervical involvement was conclusively identified. The 5-year actuarial survival for patients with true surgical stage II endometrial carcinoma (N = 24) was 76%. Extrauterine disease was documented in 32% (27/84) of patients in which the primary treatment modality was surgical. The 5-year actuarial survival was 65% for all patients with clinical surgical stage II disease. There appeared to be a survival advantage for patients treated by radical surgery as compared with more conventional treatments, especially in patients with numerous high-risk factors. The subgroup of patients (N = 53) having tumor grossly involving the cervix had a 5-year survival of 48%. In this subgroup of patients, radical hysterectomy offered improved 5-year survival over more traditional forms of treatment, particularly compared with simple hysterectomy or combined treatment with radiation and surgery. Multivariate analysis positively correlated myometrial invasion, grade, uterine serosal involvement, lower uterine segment involvement, adnexal metastasis, pelvic metastasis, aortic node metastasis, and peritoneal cytology, with disease-free survival. Clinical and surgical findings correlated poorly; therefore, primary surgical evaluation is recommended when possible.

Adenocarcinoma↗
PubMed1993

Induction of cytochrome P-450-dependent enzyme activities in cultured rat liver slices.

Precision-cut liver slices were prepared from male Sprague-Dawley rats with a Krumdieck tissue slicer and cultured in RPMI 1640 medium for up to 72 hr. After 48 hr, cytochrome P-450 content in the slices declined to 36% of levels present in freshly cut rat liver slices. The addition of either beta-naphthoflavone (BNF) or Aroclor 1254 (ARO) partially prevented the loss of cytochrome P-450. Culture of liver slices with phenobarbitone (PB), BNF and ARO resulted in the induction of 7-ethoxycoumarin O-deethylase, 7-benzoxyresorufin O-debenzylase and 7-ethoxyresorufin O-deethylase activities. Generally, the induction of mixed-function oxidase enzymes was greater in 72- than in 48-hr cultured slices, and at the concentrations examined ARO produced a greater stimulation of enzyme activities than did either PB or BNF. These results demonstrate that rat liver slices may be maintained in culture for up to 72 hr, and that they respond in a similar manner to rat primary hepatocyte cultures to some inducers of xenobiotic metabolism. Precision-cut liver slices may therefore be a useful alternative in vitro system to hepatocyte cultures for screening compounds for effects on mixed-function oxidases and for assessing species differences in response.

Animals↗
PubMed1993

Measurement of DNA damage by electrons with energies between 25 and 4000 eV.

All ionizing radiations deposit energy stochastically along their tracks. The resulting distribution of energies deposited in a small target such as the DNA helix leads to a corresponding spectrum in the severity of damage produced. So far, most information about the probable spectra of DNA lesion complexity has come from Monte Carlo studies which endeavour to model the relationship between the energy deposited in DNA and the damage induced. The aim of this paper is to establish methods of determining this relationship by irradiating pBR322 plasmid DNA using low energy electrons with energies comparable with the minimum energy thought to produce critical damage. The technique of agarose gel electrophoresis has been used to ascertain the fraction of DNA single- and double-strand breaks induced by monoenergetic electrons with energies as low as 25 eV. Our data show that the threshold electron energy for induction of single-strand breaks is < 25 eV, and for double-strand breaks between 25 and 50 eV.

DNA↗
PubMed1993

Morphine-6-glucuronide disposition in renal impairment.

Twelve patients with chronic renal failure (dialysis-dependent) and six with good renal function after renal transplantation received i.v. morphine-6-glucuronide (M6G) 30 micrograms kg-1 as part of a standardized anaesthetic technique for minor surgery. Continuous peritoneal dialysis was commenced 6 h after M6G administration in six of the dialysis-dependent patients. Serum was sampled for up to 12 h and analysed for morphine and M6G by high pressure liquid chromatography. Morphine was not detected. Mean (SD) derived pharmacokinetic variables for the three groups (transplant, renally impaired non-dialysed and renally impaired dialysed, respectively) were: elimination half-life 2.14 (0.69) h, 27.10 (15.8) h, 17.33 (4.6) h; clearance 96.0 (34.9) ml min-1, 10.57 (5.57) ml min-1, 14.3 (6.2) ml min-1; volume of distribution 0.19 (0.03) litre kg-1, 0.25 (0.06) litre kg-1, 0.27 (0.06) litre kg-1. The elimination half-life was shorter (P < 0.01) and the clearance greater (P < 0.01) for the transplanted group compared with the dialysed and non-dialysed groups. Peritoneal dialysis for the second 6 h after drug administration had little effect on M6G disposition as assessed by comparison with data obtained from the non-dialysed group.

Adolescent↗
PubMed1993

A clinical audit of cotside blood glucose measurement in the detection of neonatal hypoglycaemia.

An evaluation of the use of cotside blood glucose measurement by BM Reflolux was undertaken as part of a unit audit programme. During the study period, 383 paired samples were obtained for both cotside and laboratory analysis. There were 328 results from the cotside which were less than 4 mmol/L. Cotside measurements consistently underestimated laboratory measurements but the differences were not related to age, gestation, weight or haematocrit. The difference between cotside measurements and laboratory results was greater at lower blood glucose values. Confidence and prediction intervals of blood glucose values from cotside measurement suggest that this technique is not reliable for the diagnosis of hypoglycaemia in the newborn. Indiscriminate and uncontrolled use of cotside glucose monitoring should not be relied upon for clinical management.

Blood Glucose↗
PubMed1993

You in Mind: a preventive mental health television series.

This study of BBC Television's 'You in Mind' series provides preliminary evidence for the benefits of a mass media approach to preventive mental health. The series was seen by a large national audience who appraised it positively. It had a greater impact in the area of understanding problems as opposed to seeing what to do about them, and a greater impact on the viewer's perceptions of the problems of people the viewers knew, as opposed to the problems of the viewers themselves. Measures of intentions to change behaviour, even when corrected for over-reporting, suggest that a significant minority of the audience had changed or intended to change their behaviour as a result of the series. However, no specific pre-post changes in coping or help-seeking were found. These findings are discussed in terms of the potential and limitations of the mass media for mental health promotion.

Adolescent↗
PubMed1993

Effect of treatment with pyrazine and some derivatives on cytochrome P450 and some enzyme activities in rat liver.

1. The effect of pyrazine and three pyrazine derivatives, namely (methylthio) methylpyrazine (MTMP), 5, 6, 7, 8-tetrahydroquinoxaline (CHP) and 5-methyl-6, 7-dihydro-5'-cyclopentapyrazine (CPP), on hepatic peroxisomal and microsomal enzyme activities have been studied in male Sprague-Dawley rats. MTMP (0.25-2 mmol/kg per day) and the other compounds (1 mmol/kg/day) were administered by i.p. injections for 3 days. 2. None of the test compounds appeared to be peroxisome proliferators as there was no marked effect on hepatic palmitoyl-CoA oxidation, and neither pyrazine nor MTMP induced microsomal lauric acid 12-hydroxylase. 3. In contrast, all four compounds induced hepatic microsomal cytochrome P450-dependent enzyme activities. MTMP induced the metabolism of several mixed-function oxidase substrates including, 7-pentoxyresorufin, 7-benzoxyresorufin, benzphetamine, 4-nitrophenol and aniline, whereas pyrazine induced the metabolism of fewer substrates but including 4-nitrophenol and aniline. 4. By Western immunoblotting MTMP was found to increase levels of CYP2B1 and CYP3A isoenzymes, whereas pyrazine increased CYP2E1. 5. Thus, while pyrazine appears to be mainly a CYP2E inducer, MTMP is a mixed inducer of cytochrome P450 isoenzymes in the CYP2B, CYP3A and CYP2E subfamilies. CPP is probably a CYP2E inducer in rat liver, whereas CHP appears to be a mixed inducer of cytochrome P450 isoenzymes in the CYP2B, CYP3A and CYP2E subfamilies.

Animals↗
PubMed1993

Evidence for induction of DNA double-strand breaks at paired radical sites.

Isolated plasmid pBR322 DNA was irradiated in the gas explosion apparatus in the presence of 10 mmol dm-3 GSH. By varying the time of the oxygen shot relative to the 5-ns pulse of electrons, the chemical repair kinetics of the oxygen-dependent free-radical precursors of DNA single- and double-strand breaks (SSBs and DSBs) can be determined. The first-order repair rate of the SSB precursors was 1370 s-1 in comparison to 2900 s-1 for DSB precursors. Under these conditions the oxygen enhancement ratio for SSBs was 3.0 in comparison to 7.5 for DSBs. This twofold difference in chemical repair rate may be interpreted on the basis of the free-radical precursor of a DSB consisting of two radicals, one on either strand of the DNA. With the chemical repair of one or other of these radicals by hydrogen atom donation from GSH, a DSB is not produced. This process will occur at twice the rate of the chemical repair of an SSB precursor consisting of a single radical. These data are consistent with the concept that DSBs are formed at the sites of clustered energy depositions with the production of a paired radical.

DNA↗
PubMed1993

An investigation into the role of post-natal health clinics in oral health education.

This project investigated the oral health information that was given to parents by health visitors at post-natal clinics. This issue was examined by conducting an investigation in one health district in the United Kingdom and, within that, three socially diverse locations. A questionnaire to evaluate parental oral health knowledge and awareness, as well as the personal characteristics of each respondent was developed, tested and administered to 92 respondents. This questionnaire was analysed and compared with previous studies in the same field. Few parents reported receiving oral health information from health visitors. In general, levels of knowledge reported by this sample were better than those reported for the national sample used for the 1983 child dental health survey (Todd and Dodd, 1985). However, fewer of this sample reported receiving oral health education compared to the national sample respondents. A major gap in their knowledge related to fluoride levels in water and fluoride supplements. As found in other studies this sample was also confused about the role of diet in dental caries. Recommendations are made for further improvement in the delivery and reception of oral health education in the post-natal period.

England↗