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Biomedical subjects

C Wright

Publications and source records attributed to C Wright.

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

Levels of PCDDs, PCDFs and non-ortho PCBs in dietary supplement fish oil obtained in Spain.

Levels of PCDDs, PCDFs and non-ortho PCBs are reported for fish oils available in Spain which are consumed by the population as a dietary supplement. Trace enrichment methodology based on the use of modified silica and activated carbon chromatography was combined with on-column extraction (FMS 100) to separate PCDDs, PCDFs and PCBs from lipid material. The extracts were further cleaned up on disposable Florisil columns and analysed by HRGC/HRMS (PCDD/F and non-ortho PCB fractions). Mean levels found in the samples were 10.50 ppt for total PCDDs and 9.95 ppt for total PCDFs. Calculated PCDD/F I-TEQ values were found to be 2.11 ppt on a lipid weight basis. Total mean levels found for co-planar PCBs (#77, 126 and 169) were 18.26 ppt and the calculated I-TEQ value was 0.31 ppt on a lipid weight basis.

Benzofurans↗
PubMed1996

Concentrations of polychlorinated dibenzo-p-dioxins and dibenzofurans in human placental and fetal tissues from the U.S. and in placentas from Yu-Cheng exposed mothers.

We report the concentrations of polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) found in human placentas and fetal tissue from the U.S. and in placentas from Yu-Cheng mothers. In placental material from sources in the U.S. we found concentrations, expressed as dioxin toxic equivalence (TEQ) values and on a lipid basis, between 8.4 and 17.6 ng/kg. In a pooled sample of fetal tissue (8-14 week) the concentration, 5.3 ng/kg, was somewhat smaller. In placental material from Taiwanese Yu-Cheng subjects much higher concentrations were found, in the range 610 to 9010 TEQ ng/kg, again on a lipid basis.

Benzofurans↗
PubMed1996

PCDDS and PCDFS in milk from farms in Derbyshire, U.K.

As part of a programme to establish the background levels of PCDD/Fs in milk in the U.K., samples of cows' milk were collected from farms in Derbyshire in 1990 and 1991. The concentrations of PCDD/Fs in the samples from two farms in the Bolsover area of Derbyshire were found to be significantly elevated compared with the normal range for PCDD/Fs in milk in the U.K. Details of the findings and the actions taken as a result are given. The concentrations of PCDD/Fs in milk from those farms previously supplying milk for human consumption are now below the Maximum Tolerable Concentration of 17.5 ng TEQ/kg fat.

Animals↗
PubMed1996

Levels of selected ortho and non-ortho polychlorinated biphenyls in UK retail milk.

Nineteen pooled samples of retail cow's milk were analysed for ortho (PCBs 28, 52, 101, 118, 138, 153 and 180) and non-ortho (PCBs 77, 126 and 169) polychlorinated biphenyls. Concentrations of individual congeners in whole milk were in the ranges 2 to 95 ng/kg for ortho substituted PCBs (51 to 2440 ng/kg fat) and 0.05 to 0.6 ng/kg for non-ortho substituted PCBs (1.3 to 15.4 ng/kg fat). These values provide a preliminary estimate of background contamination levels for polychlorinated biphenyls in UK milk. Results expressed in TEQs, using the recently proposed WHO/IPCS TEFs, averaged 0.06 ng TEQ/kg whole milk.

Animals↗
PubMed1996

Assessment of preoperative accelerated radiotherapy and chemotherapy in stage IIIA (N2) non-small-cell lung cancer.

Forty patients with N2 non-small-cell lung cancer (stage IIIA), as determined by mediastinoscopy, were entered into a preoperative neoadjuvant study of chemotherapy (platinum, 5-fluorouracil, vinblastine) and accelerated radiotherapy (150 cGy twice per day for 7 days) for two cycles. Surgical resection was then performed and followed up with an additional cycle of chemotherapy and radiotherapy. All patients completed preoperative therapy. A major clinical response was seen in 87% of patients. Thirty-five patients underwent resection (one preoperative death, one refused operation, one had deterioration of pulmonary function, and two had pleural metastases). Operative mortality rate was 5.7% (2/35). Sixty percent of patients had no complications. Major complications included pulmonary emboli (three), pneumonia (two), and myocardial infarction (one). Down-staging was seen in 46% of patients, with two patients (5.7%) having no evidence of tumor in the specimen, five patients having sterilization of all lymph nodes, and nine patients having sterilization of mediastinal nodes but positive N1 nodes. Median survival of 40 patients was 28 months, with a projected 5-year survival of 43%. Patients with downstaged disease had statistically significant improved survival compared with patients whose disease was not downstaged.

Antineoplastic Agents↗
PubMed1996

C-erbB-2 in bladder cancer: molecular biology, correlation with epidermal growth factor receptors and prognostic value.

PURPOSE: To study the c-erbB-2 oncogene in primary transitional cell bladder cancer. MATERIALS AND METHODS: Ninety-five patients with known clinical follow-up and epidermal growth factor receptor (EGFr) status were studied for expression of c-erbB-2 by immunostaining. Possible mechanisms underlying increased staining for c-erbB-2 protein were investigated by analyzing DNA and RNA encoding c-erbB-2. RESULTS: Strong positive staining for c-erbB-2 was detected in 20 (21%) tumors, with weaker staining in a further 13 (14%). There was no correlation between increased staining for c-erbB-2 and tumor stage, grade, or EGFr status. There was a low rate of amplification of the c-erbB-2 gene (1 of 24) on Southern blotting with a higher rate of elevated c-erbB-2 mRNA (4 of 44) with dot blot hybridization. For pT1 tumors, the rate of recurrence was higher for those tumors which were positive for c-erbB-2. CONCLUSIONS: c-erbB-2 oncoprotein is expressed by a significant proportion of transitional cell tumors of the bladder. In this study, the prognostic significance of c-erbB-2 expression appears limited.

Blotting, Southern↗
PubMed1996

The serum immune response of young lambs to a primary infection with Nematodirus battus.

Young lambs (6-8 weeks of age) were infected with 50000 infective stage larvae of the trichostrongyle nematode Nematodirus battus. Initial mean adult worm burdens of 23884 +/- 1678 (S.E.M.) at day 14 post-infection (p.i.) were reduced significantly (P < 0.01) to a mean burden of 5383 +/- 1397 by day 21 p.i. Blood samples were taken and serum analysed using ELISA and Western blotting techniques for IgG antibodies specific for N. battus. Pre-infection serum from young naive animals showed IgG recognition of adult and larval N. battus whole worm homogenate. Recognition of adult antigens became reduced during the first 14 days after infection, followed by a subsequent increase beginning between days 14 and 18 p.i. and peaking at day 28 p.i. IgM recognition of N. battus antigens showed a single response peak, starting between days 14 and 18 p.i., without the pre-infection elevated titre as observed with IgG. These results show that young lambs can mount a significant serum response to a primary infection with N. battus during rejection of adult worms and that lambs receive from their dams IgG antibodies that are capable of recognizing adult and larval N. battus during the first few weeks of life.

Animals↗
PubMed1996

Fetal pathology in intrauterine death due to parvovirus B19 infection.

OBJECTIVES: To study the pathological features of fetuses dying because of parvovirus B19 infection, with particular reference to the presence of hydrops; to assess the usefulness of immunochemistry as a screening method for the detection of parvovirus infection at post-mortem examination. DESIGN: Review of clinical, sonographic, serological and pathological data; immunohistochemical staining of post-mortem tissue. SAMPLE: Cases of intrauterine fetal death occurring during the 18-month period January 1993 to June 1994 inclusive, referred for post-mortem examination to the Pathology Department, Royal Victoria Infirmary, Newcastle upon Tyne. RESULTS: Eleven cases of fetal death due to parvovirus infection were identified. Seven fetuses were less than 18-week size. Three fetuses showed conspicuous hydropic change. One of the 11 cases was detected for the first time by retrospective immunochemical screening. Of cases originating from the Newcastle district, parvovirus infection was responsible for about 10% of all non-malformed fetal deaths occurring between 10 and 24 weeks of gestation referred for pathological examination. CONCLUSIONS: During the period of study, parvovirus infection was a relatively common cause of mid-trimester fetal death. Many fetuses dying because of this infection are not noticeably hydropic, and the possibility of parvovirus infection should be considered in any case of intrauterine fetal death. Immunochemistry can be used to confirm the histopathological diagnosis, and may be of particular help where there is advanced autolysis; immunohistochemical screening may detect occasional cases not initially identified by examination of routinely stained tissue sections.

Autopsy↗
PubMed1996

Height and weight achievement in cleft lip and palate.

Growth was studied in 83 children with cleft lip and/or palate aged 0-4 years attending a specialist regional centre. Information was collected by a personal interview, postal questionnaire, and record review. The group as a whole grew relatively poorly in early infancy but subsequently recovered, attaining both expected weight and height by last follow up at age 25.5 months (range 3 to 47). However, the group proved heterogeneous, with children with isolated clefts of the secondary palate showing the most abnormal growth. Children with underlying syndromes were significantly more likely to be short at follow up, while type or severity of cleft was not significantly related to follow up height. Therefore, while cleft palate was associated with significant growth faltering in early infancy, rapid recovery took place following surgical repair and appears to have resulted in no residual growth deficit.

Body Height↗
PubMed1996

Early continuous ST segment monitoring in unstable angina: prognostic value additional to the clinical characteristics and the admission electrocardiogram.

BACKGROUND AND OBJECTIVE: In unstable angina, clinical characteristics, resting electrocardiography, and early continuous ST segment monitoring have been individually reported to identify subgroups at increased risk of adverse outcome. It is not known, however, whether continuous ST monitoring provides additional prognostic information in such a setting. DESIGN: Observational study of 212 patients with unstable angina without evidence of acute myocardial infarction admitted to district general hospitals, who had participated in a randomised study comparing heparin and aspirin treatment versus aspirin alone. METHODS: Clinical variables and a 12 lead electrocardiogram (ECG) were recorded at admission, and treatment was standardised to include aspirin, atenolol, diltiazem, and intravenous glyceryl trinitrate, in addition to intravenous heparin (randomised treatment). Continuous ST segment monitoring was performed for 48 h and all inhospital adverse events were recorded. RESULTS: The admission ECG was normal in 61 patients (29%), showed ST depression in 59 (28%) (17 > or = 0.1 mV), and T wave changes in a further 69 (33%). The remaining 23 had Q waves (18), right bundle branch block (four), or ST elevation (one). During 8963 h of continuous ST segment monitoring (mean 42.3 h/patient), 132 episodes of transient myocardial ischaemia (104 silent) were recorded in 32 patients (15%). Forty patients (19%) had an adverse event (cardiac deaths (n = 3), non-fatal myocardial infarction (n = 6) and, emergency revascularisation (n = 31)). Both admission ECG ST depression (P = 0.02), and transient ischaemia (P < 0.001) predicted an increased risk of non-fatal myocardial infarction or death, while no patients with a normal ECG died or had a myocardial infarction. Adverse outcome was predicted by admission ECG ST depression (regardless of severity) (odds ratio (OR) 3.41) (P < 0.001), and maintenance beta blocker treatment (OR 2.95) (P < 0.01). A normal ECG predicted a favourable outcome (OR 0.38) (P = 0.04), while T wave or other ECG changes were not predictive of outcome. Transient ischaemia was the strongest predictor of adverse prognosis (OR 4.61) (P < 0.001), retaining independent predictive value in multivariate analysis (OR 2.94) (P = 0.03), as did maintenance beta blocker treatment (OR 2.85) (P = 0.01) and admission ECG ST depression, which showed a trend towards independent predictive value (OR 2.11) (P = 0.076). CONCLUSIONS: Patients with unstable angina and a normal admission ECG have a good prognosis, while ST segment depression predicts an adverse outcome. Transient myocardial ischaemia detected by continuous ST segment monitoring in such patients receiving optimal medical treatment provides prognostic information additional to that gleaned from the clinical characteristics or the admission ECG.

Adrenergic beta-Antagonists↗
PubMed1996

Women with chest pain: is exercise testing worthwhile?

OBJECTIVE: To determine the diagnostic value of the exercise tolerance test (ETT) in women presenting with chest pain. DESIGN: Prospective study of all women presenting to a centre with chest pain between 1987 and 1993 who were assessed by an ETT and coronary angiography. SETTING: The outpatient clinic of one consultant cardiologist in a tertiary referral centre. PATIENTS: All women referred to this outpatient clinic with chest pain were screened. For inclusion, patients had to perform ETT and undergo coronary angiography. Of the 347 referred during this period, 142 were excluded because they were unable to perform ETT or because of Q waves or other abnormalities on their resting electrocardiogram. RESULTS: Overall the sensitivity of the ETT was 68% and the specificity was 61%, with a positive predictive value of 0.61 and a negative predictive value of 0.68. There were 42 false positive and 31 false negative ETT results (36% of the study group). The predictive value of a negative test was higher in younger women (< 52 years) than in the older group (> or = 52 years) (P = 0.004), but the positive predictive value in the two groups was not significantly different. The predictive value of a negative test was also higher in those with two or fewer risk factors than in those with three or more risk factors (P = 0.001). The negative predictive value for those women above 52 years with three or more risk factors (24% of the study group) was only 0.25. Lack of chest pain during ETT was associated with a higher negative predictive value in the younger group than in the older women (P = 0.006). CONCLUSIONS: In women with chest pain use of the ETT was a misleading predictor of the presence or absence of coronary disease in 36% of these patients. In particular, a negative test in older women with three or more risk factors had a very low predictive value. The inclusion of risk factors and division by age can, however, be used to identify a population at intermediate risk for coronary artery disease in whom the ETT result has the highest diagnostic utility.

Adult↗
PubMed1996

Natural variability of transient myocardial ischaemia during daily life: an obstacle when assessing efficacy of anti-ischaemic agents?

OBJECTIVE: To assess the degree of variability of transient myocardial ischaemia during daily life in patients with coronary artery disease, which could confound the interpretation of trials of the therapeutic effects of anti-ischaemic agents. DESIGN: Prospective method evaluation. SETTING: Tertiary referral centre, outpatient clinic. PATIENTS: Patients with stable angina, confirmed coronary artery disease, and a positive treadmill exercise test for ischaemia. Patients were not preselected on the basis of prior documented transient ischaemia during ambulatory ST segment monitoring. INTERVENTIONS: A simulated drug-study with 4 monitoring phases in 16 subjects. To minimise variability in ischaemic activity, patients underwent weekly 48 hour ambulatory ST segment monitoring outside hospital off all prophylactic therapy on the same weekdays for 4 weeks. MAIN OUTCOME MEASURE: Variability in the frequency and duration of transient myocardial ischaemia. RESULTS: There was marked variability in both ischaemic activity and mean duration of ischaemia in patients with confirmed ischaemia, the greatest degree of variability being between patients and from day to day within weeks within patients, with a further contribution to variability being noted between fortnights within patients. CONCLUSIONS: Despite assessment off all therapy and an adequate period of monitoring (48 hours) with small intervals between monitoring periods (5 days), marked variability in ischaemic activity was noted, and regression towards the mean was clearly shown. Ambulatory ST segment monitoring outside hospital is not a reliable method for assessing the therapeutic effects of anti-ischaemic agents.

Activities of Daily Living↗
PubMed1996

Housing accommodation preferences of people with psychiatric disabilities.

OBJECTIVE: The study sought to identify the types of housing preferred by people with psychiatric disabilities seeking accommodations through a community mental health service in Sydney, Australia. METHODS: Housing options available in the mental health service's catchment area were identified, and the extent of demands on residents' behavior that was associated with each option was assessed using an established measure. Clients examined descriptions of each housing option and rank-ordered the options based on their preferences. Clients' current levels of functioning and symptoms were also assessed. RESULTS: Clients most preferred environments that ensured living alone in settings of low behavioral demand. Living in one's own home was the most preferred option, followed by living in government-subsidized housing, For-profit boarding houses were preferred over psychiatric group homes, and homelessness, long-term hospitalization, and crisis accommodations were least preferred. Shelter, privacy, food, and safety were highly valued housing attributes. Demographic characteristics, level of functioning, and severity of psychiatric symptoms did not predict accommodation preferences. CONCLUSION: Consumers' resistance to psychiatric group housing with high levels of behavioral demand is unrelated to consumer characteristics and should be considered in planning suitable accommodations for persons with psychiatric disabilities.

Activities of Daily Living↗
PubMed1996

Transverse sternothoracotomy.

Transverse sternothoracotomy (the clamshell incision) has been resurrected from the early days of cardiac surgery and is now used for double lung transplantation, bilateral pulmonary tumors, and selected mediastinal tumors. Bulky mediastinal tumors that project into the pleural space are exposed well with this incision.

Humans↗
PubMed1995

Design and production of a target-specific monoclonal antibody to parvovirus B19 capsid proteins.

Native parvovirus B19 was used as antigen to produce a mouse monoclonal antibody, R92F6, which reacted with B19 VP1 and VP2, neutralised the virus in bone marrow culture, and labelled infected cells in paraffin-embedded tissues from cases of B19-related fetal hydrops. The B19 epitope recognised by R92F6 (amino acids 328-344 from the amino terminal region of B19 VP2) appears to be highly conserved, since these tissue specimens were obtained over a 13 year period from widely spaced locations in the UK. This epitope was synthesised as a peptide (S7b) which was used as antigen to produce a mouse monoclonal antibody, 3H8, which specifically reacted with the B19 capsid proteins VP1 and VP2 in immunofluorescence and immunoblot assays. 3H8 was also capable of labelling formalin-fixed, paraffin-embedded, B19-infected fetal tissue and was shown to be of the same isotype as R92F6 (IgG1). Highly conserved epitopes derived from conserved amino acid sequences are valuable in the diagnosis of infectious disease. If these can be recognised and accurately synthesised, the production of specific mouse monoclonal antibodies may be possible for many human pathogens. Considering the vast amount of sequence data available in the literature, this approach seems to be both feasible and of wide potential.

Animals↗
PubMed1995

O2-sensitive K+ currents in carotid body chemoreceptor cells from normoxic and chronically hypoxic rats and their roles in hypoxic chemotransduction.

Carotid body-mediated ventilatory increases in response to acute hypoxia are attenuated in animals reared in an hypoxic environment. Normally, O2-sensitive K+ channels in neurosecretory type I carotid body cells are intimately involved in excitation of the intact organ by hypoxia. We have therefore studied K+ channels and their sensitivity to acute hypoxia (PO2 12-20 mmHg) in type I cells isolated from neonatal rats born and reared in normoxic and hypoxic environments. When compared with cells from normoxic rats, K+ current density in cells from hypoxic rats was significantly reduced, whereas Ca2+ current density was unaffected. Charybdotoxin (20 nM) inhibited K+ currents in cells from normoxic rats by approximately 25% but was without significant effect in cells from hypoxic rats. However, hypoxia caused similar, reversible inhibitions of K+ currents in cells from the two groups. Resting membrane potentials (measured at 37 degrees C using the perforated-patch technique) were similar in normoxic and hypoxic rats. However, although acute hypoxia depolarized type I cells of normoxic rats, it was without effect on membrane potential in type I cells from hypoxic animals. Charybdotoxin (20 nM) also depolarized cells from normoxic rats. Our results suggest that type I cells from chronically hypoxic rats, like normoxic rats, possess O2-sensing mechanisms. However, they lack charybdotoxin-sensitive K+ channels that contribute to resting membrane potential in normoxically reared rats, and this appears to prevent them from depolarizing (and hence triggering Ca2+ influx and neurosecretion) during acute hypoxia.

Animals↗
PubMed1995

A case of paternal uniparental disomy for chromosome 11.

We report a case of paternal uniparental disomy for chromosome 11 that presented as severe intrauterine growth retardation. Autopsy following intrauterine death also revealed aberrant intestinal rotation and hypospadias. Chromosome analysis of direct preparations from placental biopsy showed an abnormal 47,XY,+11 karyotype. Analysis of long-term cultures from the placenta revealed 46,XY/47,XY,+11 mosaicism. Fluorescence in situ hybridization (FISH) studies on interphase nuclei confirmed trisomy 11 in multiple placental sites but detected only disomic cells in fetal skin. Investigation using microsatellite polymorphisms demonstrated paternal isodisomy at loci D11S909, D11S956, and D11S488, and paternal heterodisomy at locus D11S928.

Adult↗