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Biomedical subjects

D Richards

Publications and source records attributed to D Richards.

At least 19 recordsLinked to original sources
PubMed1997

Perceptions of diabetes among rural Maori elders and spokespersons.

AIMS: To assess knowledge and opinions of diabetes among rural Maori elders and spokespersons. METHODS: Interviews were conducted in rural South Auckland. Subjects were identified through their affiliation with one marae (meeting house), residence near the marae and being recognised locally as either male (kaumatua) or female (kuia) elders or spokespersons. The main researcher was a kuia chosen by and from within the local community. Interviews were conducted with 43/44 (98%) subjects identified. RESULTS: While specific diabetes knowledge was low, diabetes was seen, along with cancer, as one of the two major health issues for Maori. Results need to be understood in the context of the holistic understanding of health by Maori. CONCLUSION: The recognition of diabetes as a major health problem was accompanied by a call for diabetes education in a form that will generate interest and participation by Maori. It is timely for the introduction of marae based diabetes awareness and sustained exercise programmes as part of a diabetes prevention and control strategy among Maori communities where diabetes risk is high.

Aged↗
PubMed1997

The role of intracellular calcium in antimony-induced toxicity in cultured cardiac myocytes.

Trivalent antimony, delivered as potassium antimonyl tartrate (PAT), has been previously shown to induce an oxidative stress and toxicity in cultured neonatal rat cardiac myocytes. The present study investigates the effect of PAT on intracellular free calcium ([Ca2+]i), which has been implicated in the toxicity of agents inducing oxidative stress, and explores its role in PAT toxicity. Exposure to 50 or 200 microM PAT led to progressive elevation in diastolic or resting [Ca2+]i and eventually a complete loss of [Ca2+]i transients that occurred well before cell death as assessed by LDH release. Prior loading of myocytes with the intracellular calcium chelator BAPTA (10 to 40 microM), protected against PAT toxicity in the presence and absence of extracellular calcium, and demonstrated a crucial role for [Ca2+]i in PAT toxicity. Exposure to 200 microM PAT in the absence of extracellular calcium slightly elevated [Ca2+]i, but only to levels comparable to resting [Ca2+]i for cells in 1.8 mM extracellular calcium. This demonstrated that although PAT toxicity was dependent on [Ca2+]i, a large increase above resting levels was not needed, and also that some calcium was mobilized from intracellular stores. However, the caffeine-releasable pool of sarcoplasmic reticulum calcium was increased, not depleted, by exposure to 200 microM PAT. These results demonstrate that PAT disrupts [Ca2+]i handling and support a role for a calcium-dependent event, but do not support the necessity of events in PAT-induced cell death that are mediated by a large elevation in [Ca2+]i.

Analysis of Variance↗
PubMed1997

Immune memory in CD4+ CD45RA+ T cells.

This study addresses the question of whether human peripheral CD4+ CD45RA+ T cells possess antigen-specific immune memory. CD4+ CD45RA+ T cells were isolated by a combination of positive and negative selection. Putative CD4+ CD45RA+ cells expressed CD45RA (98.9%) and contained < 0.1% CD4+ CD45RO+ and < 0.5% CD4+ CD45RA+ CD45RO+ cells. Putative CD45RO+ cells expressed CD45RO (90%) and contained 9% CD45RA+ CD45RO+ and < 0.1% CD4+ CD45RA+ cells. The responder frequency of Dermatophagoides pteronyssinus-stimulated CD4+ CD45RA+ and CD4+ CD45RO+ T cells was determined in two atopic donors and found to be 1:11,314 and 1:8031 for CD4+ CD45RA+ and 1:1463 and 1:1408 for CD4+ CD45RO+ T cells. The responder frequencies of CD4+ CD45RA+ and CD4+ CD45RO+ T cells from two non-atopic, but exposed, donors were 1:78031 and 1:176,903 for CD4+ CD45RA+ and 1:9136 and 1:13,136 for CD4+ CD45RO+ T cells. T cells specific for D. pteronyssinus were cloned at limiting dilution following 10 days of bulk culture with D. pteronyssinus antigen. Sixty-eight clones were obtained from CD4+ CD45RO+ and 24 from CD4+ CD45RA+ T cells. All clones were CD3+ CD4+ CD45RO+ and proliferated in response to D. pteronyssinus antigens. Of 40 clones tested, none responded to Tubercule bacillus purified protein derivative (PPD). No difference was seen in the pattern of interleukin-4 (IL-4) or interferon-gamma (IFN-gamma) producing clones derived from CD4+ CD45RA+ and CD4+ CD45RO+ precursors, although freshly isolated and polyclonally activated CD4+ CD45RA+ T cells produced 20-30-fold lower levels of IL-4 and IFN-gamma than their CD4+ CD45RO+ counterparts. Sixty per cent of the clones used the same pool of V beta genes. These data support the hypothesis that immune memory resides in CD4+ CD45RA+ as well as CD4+ CD45RO+ T cells during the chronic immune response to inhaled antigen.

Allergens↗
PubMed1997

Type of hospital setting and treatment outcome with heroin addicts. Results from a randomised trial.

BACKGROUND: General psychiatrists have recently been encouraged to provide treatment to heroin addicts, including in-patient detoxification. No comparison has previously been made of specialist versus general psychiatric in-patient care. METHOD: During a randomised study of cue exposure, 186 opiate addicts were also randomised to either specialist in-patient (DDU; n = 115) or general psychiatric (GEN; n = 71) wards in the same hospital. RESULTS: From pre-treatment (post-randomisation) onwards, patient outcomes differed across the two in-patient settings. Of the original randomised sample, significantly more DDU than GEN subjects accepted their randomisation (100 v. 77%), were subsequently admitted (60 v. 42%), and completed in-patient detoxification (45 v. 18%). Of patients admitted, more DDU than GEN patients completed detoxification (75 v. 43%). During seven-month follow-up, of those 43 patients who reached the end of treatment, significantly more ex-DDU than ex-GEN subjects were opiate-free. CONCLUSIONS: From pre-treatment onwards, significant differences in process and outcome were found after allocation to treatment on either DDU or GEN. Further randomised studies are required to replicate and explain these findings.

Adult↗
PubMed1997

Growth retardation in fetuses with gastroschisis.

This study was designed to determine the prevalence of intrauterine growth restriction in neonates with gastroschisis and to evaluate the accuracy of the ultrasonographic diagnosis of intrauterine growth restriction. Birth weight and gestational age were determined for 46 infants diagnosed prenatally as having gastroschisis. Biometric data were analysed for the 30 pregnancies in which an examination was conducted within 1 week of delivery. Fetal growth parameters were compared with norms for gestational age. The prevalence of intrauterine growth restriction in the entire study group was 24% with a mean birth weight of 2401 +/- 508 g. Ultrasonographic estimated fetal weight was significantly less than birth weight (mean, 2079 +/- 508 g versus 2331 +/- 512 g, respectively; P < 0.0001). Intrauterine growth restriction was predicted in 43% of infants but was present in only 23%. The percentage difference between measured abdominal circumference and gestational age norm was significantly more than for biparietal diameter and for femur length (P < 0.001). Of the three biometric measures, only the difference between measured abdominal circumference and gestational age norms and the difference between estimated fetal weight and birth weight showed a significant correlation. Both abdominal circumference and femur length correlated with the difference between estimated fetal weight and birth weight. We conclude that the prevalence of intrauterine growth restriction is increased in infants with gastroschisis but is overestimated with prenatal ultrasonography, primarily because of smaller than average abdominal circumference measurements.

Abdominal Muscles↗
PubMed1996

Calcium dynamics in cardiac myocytes as a target of dichloromethane cardiotoxicity.

The purpose of the present study was to determine if cardiac actions of dichloromethane (DCM) in vivo correlate with in vitro alterations of Ca2+ dynamics in cardiac myocytes. Neonatal rat ventricular myocytes were obtained from 2- to 4-day-old rats, and electrically induced fluctuations of cytosolic free Ca2+ concentration ([Ca2+]i) in single cardiomyocytes were investigated using spectrofluorometric analysis of fura-2-[Ca2+]i binding. In cultured myocytes, cumulative exposure to 0.64-40.96 mM DCM resulted in a concentration-dependent and reversible decrease in the magnitude of [Ca2+]i transients with IC10 and IC50 values of 7.98 and 18.82 mM, respectively. Total inhibition of [Ca2+]i transients and cessation of beating were observed at 40.96 mM DCM. Suffusion with DCM for 40 min did not cause morphological alterations of the myocytes. In a urethane-anesthetized rat model, left ventricular pressure was measured by introducing a tip catheter via the carotid artery into the left ventricle, the ECG was recorded by two needle electrodes applied subcutaneously to the chest wall, and arterial pressure was measured via the femoral artery. Oral administration of 3.1-12.4 mmol DCM/kg resulted in DCM blood concentrations between 1.0 and 1.6 mM, accompanied by a dose-dependent decrease in contractile force and heart rate without influencing blood pressure and ECG tracings. Moreover, DCM treatment provided significant protection against arrhythmia development due to CaCl2-infusion. In spite of the slight discrepancy between DCM blood concentrations and in vitro concentrations of DCM for [Ca2+]i transient inhibition, present data are consistent with the view that cardiac effects after DCM exposure are mediated by alterations of Ca2+ dynamics during excitation-contraction coupling.

Anesthesia↗
PubMed1996

Premature senescence of skin fibroblasts from insulin-dependent diabetic patients with kidney disease.

Diabetic glomerulopathy develops in a subset only of patients with insulin-dependent diabetes (IDDM) and early, in its course, is characterized by cell hypertrophy and by excessive extracellular matrix production. These observations suggest that an alteration in the control of cell growth processes may contribute to its pathogenesis and be related to the susceptibility to kidney disease. We therefore investigated whether the development of diabetic nephropathy is associated with abnormalities of cell growth and morphology. Cultured skin fibroblasts from 14 IDDM patients with nephropathy (DN) were compared with those of 10 IDDM patients without nephropathy (D) and of 14 control non-diabetic subjects (C). Cell volume (in arbitrary units) and total protein content (microgram/10, 000 cells) were increased in serially passaged skin fibroblasts of IDDM patients with nephropathy (DN = 809.5 +/- 33.1 and 1.93 +/- 0.38 vs. D = 764.4 +/- 31.5 and 1.5 +/- 0.37, P = 0.005 and P = 0.03, respectively; vs. C = 756.2 +/- 36.3 and 1.5 +/- 0.38, P = 0.0006 and P = 0.03, respectively). These hypertrophic cells had a tendency to a slower duplication rate and exhibited a dissociation of the DNA and cytoplasmic cell-cycles, resulting in a higher proportion of tetraploid cells (DN = 25 +/- 15% vs. D = 6 +/- 4%, P = 0.005; and vs. C = 10 +/- 8%, P = 0.04). The frequency of terminally differentiated post-mitotic fibrocytes, cells specialized for extracellular matrix production, was higher in patients with nephropathy compared to that of patients without nephropathy and normal controls (DN = 34 +/- 14% vs. D = 21 +/- 10%, P = 0.02; and vs. C = 19 +/- 12%, P = 0.008). That early differentiation was a specific feature of cells derived from patients with diabetic nephropathy was confirmed by the study of cell life-span which demonstrated that these cells aged prematurely (log rank test, chi 2 = 10,012; P = 0.0067). We conclude that an acceleration of cell aging is a peculiar feature of diabetic kidney disease and may contribute to its pathological tissue changes.

Adult↗
PubMed1996

Study of the aetiology of wheezing illness at age 16 in two national British birth cohorts.

BACKGROUND: Data from two national British birth cohorts were used to measure the increase in prevalence of wheezing illness at age 16 between 1974 and 1986, and to investigate the role of several potential risk factors in the increase. METHODS: The occurrence of self-reported asthma or wheezy bronchitis within the past year, and the frequency of attacks of wheezing illness at age 16, were compared in 11,262 and 9266 children born in one week of 1958 and 1970, respectively. The effects of several putative risk factors for asthma--including birth weight, maternal age, birth order, breast feeding, maternal smoking in pregnancy, child's personal smoking, and father's social class--on the change in occurrence of wheezing illness at age 16 were assessed by multiple logistic regression. RESULTS: The annual period prevalence of asthma or wheezy bronchitis at age 16 increased from 3.8% in 1974 to 6.5% in 1986 (prevalence ratio (PR) = 1.71, 95% CI 1.52 to 1.93). The proportion of children experiencing attacks more than once a week increased from 0.2% to 0.7% (PR = 3.77, 95% CI 2.28 to 6.23). The prevalence of self-reported eczema and hayfever within the past year doubled between 1974 and 1986, suggesting that the increase in asthma was part of a general increase in the prevalence of atopic disease. However, in the complete dataset, after adjustment for the effects of the risk factors studied, the prevalence odds ratio for asthma or wheezy bronchitis in 1986 compared with 1974 was virtually unchanged from the unadjusted value at 1.77 (95% CI 1.46 to 2.15). CONCLUSION: The prevalence of wheezing illness in British teenagers increased by approximately 70% between 1974 and 1986. This increase appears to have occurred in the context of a general increase in atopic disease and was largely unexplained by changes in the distribution of maternal age, birth order, birth weight, infant feeding, maternal smoking, active smoking by the child, or father's social class.

Adolescent↗
PubMed1996

Correlation of prenatal renal pelvic anteroposterior diameter with outcome in infancy.

PURPOSE: We attempted to correlate prenatal renal pelvic anteroposterior diameter with outcome in infancy. MATERIAL AND METHODS: Between May 1992 and March 1994 we identified 27 cases of fetal hydronephrosis in which renal pelvic anteroposterior diameter was 4 mm. or greater before 33 weeks of gestation and 7 mm. or greater at or after 33 weeks of gestation. RESULTS: Hydronephrosis was bilateral in 18 fetuses and unilateral in 9. Shortly after birth radiological assessment revealed vesicoureteral reflux in 6 neonates, ureteropelvic junction obstruction in 6, extrarenal pelves in 3 and persistent nonobstructive hydronephrosis in 4. Radiological evaluation was normal in 8 newborns. CONCLUSIONS: When these screening criteria for hydronephrosis are met prenatally a complete radiological assessment should be done following birth.

Analysis of Variance↗
PubMed1996

Medical students in general practice: how do patients feel?

BACKGROUND: The General Medical Council has recommended that medical students should gain more experience in general practice. AIM: The study set out to determine patients' reactions to the presence of medical students in general practice consultations. METHOD: Patients attending a random sample of general practice surgeries completed a questionnaire following consultation with and without a medical student present in six general practices in the Oxford area. RESULTS: The questionnaires were completed by 278 patients. Only eight (3%) of all respondents had negative responses to the presence of a medical student. Of those completing questionnaires following a teaching consultation, 107 (56%) felt positively about the presence of students, compared with 36 (41%) who had attended a nonteaching surgery. Only three patients (1%) felt the quality of the consultation to be impaired by the presence of a student, while 48 patients (17%) felt there to be some improvement. The majority felt that the sex of the student was unimportant, but significantly more female than male patients (17% versus 5%) felt that it made a difference. CONCLUSION: Only a small proportion of patients object to the presence of a medical student in general practice consultations. A significant minority said that the presence of a student improves the consultation.

Attitude to Health↗
PubMed1995

Evidence based dentistry.

We live in an age of information, innovation and change. Clinical decision making based on good quality evidence should lead to more effective and efficient treatments. Each practitioner has a role in assessing this information. This paper outlines this role, together with the advantages and problems of introducing an evidence based approach to dentistry.

Clinical Competence↗