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Biomedical subjects

J E Wells

Publications and source records attributed to J E Wells.

At least 37 records · Page 2Linked to original sources
PubMed1997

Spinal injuries in New Zealand rugby and rugby league--a twenty year survey.

AIMS: To establish trends in frequency of serious spinal cord injuries in rugby and rugby league over a 20 year period and to elucidate patterns of injury from retrospective analysis of cases admitted to New Zealand's two spinal injuries units. METHODS: A detailed survey of unit records with follow-up of selected patients; statistical analysis of data. RESULTS: During the 20 years 1976 to 1995, 119 rugby and 22 rugby league players (total 141) were admitted to New Zealand's two spinal injuries units suffering serious spinal injuries and 47 of these became permanently confined to wheelchairs. There was a steady increase in frequency throughout the period studied. Of the injuries 83% occurred in forwards and 17% in backs. In rugby it was the scrum which produced most injuries, and in rugby league it was the tackle. The early season month of April produced most spinal injuries. In the eighteen months since intense compulsory educational programmes on safety were introduced by the New Zealand Rugby Union there have been no serious spinal cord injuries from rugby scrums. CONCLUSION: Contrary to widespread belief, there has not been a decrease in spinal cord injuries in rugby following rule changes in the mid 1980s. The information produced by this retrospective study has been an effective educational platform to make rugby and rugby league safer.

Adult↗
PubMed1997

The cross-national epidemiology of panic disorder.

BACKGROUND: Epidemiological data on panic disorder from community studies from 10 countries around the world are presented to determine the consistency of findings across diverse cultures. METHOD: Data from independently conducted community surveys from 10 countries (the United States, Canada, Puerto Rico, France, West Germany, Italy, Lebanon, Taiwan, Korea, and New Zealand), using the Diagnostic Interview Schedule and DSM-III criteria and including over 40,000 subjects, were analyzed with appropriate standardization for age and sex differences among subjects from different countries. RESULTS: The lifetime prevalence rates for panic disorder ranged from 1.4 per 100 in Edmonton, Alberta, to 2.9 per 100 in Florence, Italy, with the exception of that in Taiwan, 0.4 per 100, where rates for most psychiatric disorders are low. Mean age at first onset was usually in early to middle adulthood. The rates were higher in female than male subjects in all countries. Panic disorder was associated with an increased risk of agoraphobia and major depression in all countries. CONCLUSIONS: Panic disorder is relatively consistent, with a few exceptions, in rates and patterns across different countries. It is unclear why the rates of panic and other psychiatric disorders are lower in Taiwan.

Adolescent↗
PubMed1997

A Prevotella ruminicola B(1)4 operon encoding extracellular polysaccharide hydrolases.

When Escherichia coli XL1-Blue MRA (P2) was infected with lambda DNA containing Prevotella ruminicola B(1)4 chromosomal DNA, only a few plaques produced beta-1,4-endoglucanase activity, and all of these had mannanase activity. Positive phage contained a 17-kb SacI DNA fragment that gave six bands after EcoRI digestion. The EcoRI fragments were ligated into pBluescript and sequenced. The order of the fragments was verified by PCR and by restriction mapping. The DNA sequence contained 6 open reading frames (ORFs). The 4th and 5th ORFs encoded two related beta-1,4-endoglucanases. E. coli clones carrying ORF5 and ORF6 had beta-1,4-endoglucanase and mannanase activities, while a clone carrying only ORF6 hydrolyzed mannan but not carboxymethylcellulose. The 6th ORF had three regions of homology to mannanase A from Pseudomonas fluorescens. Based on these results, ORF6 encoded the mannanase gene. The 3rd ORF had 10 regions of homology with cellulose-binding protein A from Clostridium cellulovorans. The 1st and 2nd ORFs had no significant homology to genes or amino acid sequences in GeneBank or SwissProt. All of the ORFs except 1 encoded a potential signal peptide sequence. The upstream region of ORF1 contained four direct repeats and four inverted repeat elements, but no apparent sigma70 sequence-like promoter was present. The segment of DNA containing the 6 ORFs was preceded and followed by potential transcription termination signals suggesting a single transcriptional unit.

Amino Acid Sequence↗
PubMed1997

The ability of 2-deoxyglucose to promote the lysis of Streptococcus bovis JB1 via a mechanism involving cell wall stability.

The non-metabolizable glucose analog, 2-deoxyglucose (2-DG), decreased the growth rate and optical density of Streptococcus bovis JB1 20%, but it had an even greater effect on stationary phase cultures. Control cultures receiving only glucose (2 mg/ml) lysed very slowly (<5% decline in optical density in 48 h), but cultures that had been grown with glucose and 2-DG (2 mg/ml each) lysed much faster (>85% decline in optical density in 48 h). Cultures that were treated with inhibitors that decreased intracellular ATP (sodium fluoride, nigericin, and valinomycin or tetrachlorosalicylanilide) or membrane potential (sodium fluoride, nigericin, and valinomycin, tetrachlorosalicylanilide, or phenylmethylsulfonyl fluoride) did not promote lysis. 2-DG had its greatest effect when it was added at inoculation. If 2-DG was added at later times, less lysis was observed, and cells that were given 2-DG just prior to stationary phase were unaffected. Cells that were grown with glucose and 2-DG were more susceptible to cell wall-degrading enzymes (lysozyme and mutanolysin) than cells that had been grown only with glucose, but sublethal doses of penicillin during growth did not promote lysis after the cells had reached stationary phase. The idea that 2-DG might be affecting autolytic activity was supported by the observation that cultures washed and resuspended in fresh medium with or without 2-DG lysed at a slower rate than cultures that were not centrifuged or were resuspended in the culture supernatant.

Adenosine Triphosphate↗
PubMed1997

Vesicoureteric reflux in the newborn: relationship to fetal renal pelvic diameter.

There has been a low yield of primary vesicoureteric reflux (VUR) from screening the fetal urinary tract during obstetric sonography. We sought to determine whether changing the cut-off level of fetal renal pelvic diameter from 10 mm to 4 mm would improve the yield of VUR. In a prospective community-based study, a fetal renal pelvic diameter of 4 mm or more on a transverse view of the fetal renal hilum at obstetric sonography after 16 weeks' gestation was found in 426 fetuses from 9,800 consecutive pregnancies. After birth, renal sonography was performed on 386 of the 426 babies. Of the 386 babies, 264 (187 boys) had a voiding cystourethrogram (VCUG) at a mean age of 9 weeks. Primary VUR was detected in 33 (16 boys) of the 264 infants (13%), and secondary VUR in another 5 (2%). Only 5 of the 33 (15%) babies with primary VUR would have been detected if a cut-off point of 10 mm for fetal renal pelvic diameter had been used. The prevalence of reflux was similar at each cut-off level of antenatal renal pelvic diameter from 4 to 10 mm. Neither calyceal nor ureteric dilatation was helpful in differentiating those with from those without VUR. The postnatal renal sonogram did not distinguish whether reflux was present or not. More infants with primary VUR, particularly girls, were found by changing the cut-off point for fetal renal pelvic diameter from 10 mm to 4 mm, and performing a VCUG on all such infants even if the postnatal renal sonogram was normal. Of the 33 infants with primary VUR, 9 (27%, 5 boys) had an abnormal dimercaptosuccinic acid scan. Our findings support the screening of the obstetric population for a fetal renal pelvic diameter of 4 mm or more, and then investigating the infants for VUR after birth.

Female↗
PubMed1997

OKT3 for the treatment of steroid-resistant acute renal allograft rejection.

OKT3 (Orthoclone) was first used in this unit on February 25, 1987. Up until March 31, 1996, 153 patients had a total of 163 transplants. Fifty of these patients who received 53 transplants (28 male, mean age 37.5 years, 48 cadaveric donors), were treated with OKT3 for steroid-resistant acute rejection. Forty-nine graft biopsies were undertaken and 47 showed acute rejection. In the other 4 episodes a clear-cut clinical and laboratory diagnosis of severe rejection was made. OKT3 (5 mg i.v.) was started at a median of 19 days following transplantation and was successful in reversing 43 of 51 (84%) episodes of steroid-resistant acute rejection. Of those treated, the patient and graft survival at 1 year was 86 and 69%, at 3 years 82 and 64% and at 5 years 79 and 61%, respectively. Adverse effects were common. Four patients died from sepsis within the first 3 months after transplantation. OKT3 was effective in reversing 84% of steroid-resistant acute rejection episodes.

Adolescent↗
PubMed1997

Breast cancer screening: the effect of self selection for screening on comparisons of randomised controlled trials.

In randomised controlled trials of breast cancer screening women are randomly allocated to an intervention group that is offered screening, or a control group that receives the usual medical care. Not all women in the intervention group accept screening; the women who do so may differ from other women in their underlying risk of breast cancer. This self selection for screening can result in either women at high risk or at low risk being overrepresented in the screened group. When comparisons between trials are made it is important to take self selection for screening into account, as a trial with self selection of women at high risk has the potential to have greater efficacy than a trial with self selection of women at low risk. A method of adjusting for self selection when comparing randomised controlled trials of breast cancer screening is described.

Breast Neoplasms↗
PubMed1996

Family history of depression in clinic and community samples.

Because most published family studies of depression ascertained subjects from treatment settings, the reported familial aggregation of depression could be an artifact if a family history of depression increased the likelihood of seeking treatment. To investigate this possibility, we compared the family history of depression in three groups of probands aged 18-44; 54 women randomly selected from the community with depression in the prior year, 41 women who entered a clinical trial for depression and 37 women randomly selected from the community who had not been depressed in the prior year. The presence of depression in the parents and siblings of the probands was assessed by the family history method and quantified via family history scores which took the age, gender and number of relatives into account. Depressed probands ascertained from clinical sources had markedly higher family history scores of depression than other two groups (P < 0.00005 in each instance). In the absence of direct interviews with relatives, we cannot exclude the impact of differential reporting. A family history of depression might be associated with an increased probability of treatment or the differential reporting of family history. It is thus possible that the familial aggregation of depression observed in probands from treatment settings is an artifact.

Adolescent↗
PubMed1996

The effect of socioeconomic status on bone density in a male Caucasian population.

We have examined the effect of socioeconomic status (SES) on bone density (BMD) in 201 males, aged 20-60 years. Males of lower SES (groups 4-6 vs. 1-3) from the total sample had significantly higher BMD (p < 0.05) at L2-4 and femoral neck. The difference was small but was not explained by differences in age, weight, calcium intake, family history, activity, or smoking. 45% of SES 4-6 males were involved in manual labor compared with 11% of those in SES 1-3, however, this also did not appear to account for the difference.

Adult↗
PubMed1996

The effect of growth and starvation on the lysis of the ruminal cellulolytic bacterium Fibrobacter succinogenes.

Growing cultures of Fibrobacter succinogenes assimilated more ammonia than could be accounted for by cellular protein, RNA, or DNA and released large amounts of nonammonia nitrogen. The difference between net and true growth was most dramatic at low dilution rates, but mathematical derivations indicated that the lysis rate was a growth rate-independent function. The lysis rate was sevenfold greater than the true maintenance rate (0.07 h-1 versus 0.01 h-1). Because slowly growing cells had as much proton motive force and ATP as fast-growing cells, lysis was not a starvation response per se. Stationary-phase cells had a lysis rate that was 10-fold less than that of growing cells. Rapidly growing cells were not susceptible to phenylmethylsulfonyl fluoride, but phenylmethylsulfonyl fluoride increased the lysis rate of the cultures when they reached the stationary phase. This latter result indicated that autolysins of stationary-phase cells were being inactivated by a serine proteinase. When growing cells were treated with the glycolytic inhibitor iodoacetate, the proteinase-dependent transition to the stationary phase was circumvented, and the rate of lysis could be increased by as much as 50-fold.

Ammonia↗
PubMed1996

Impulsivity in disordered eating, affective disorder and substance use disorder.

BACKGROUND: Failure to control impulsive behaviour has been postulated as an underlying mechanism common to substance use disorder, sociopathy and to a substantial subgroup of women with bulimia nervosa. METHOD: Three hundred and one women recruited to a general population study were selected either at random or because they had lifetime substance use disorder, affective disorder or symptoms of bulimia. A subsequent interview determined the existence of problems with impulsivity. Behaviour that is an integral part of a DSM-III axis 1 disorder was excluded from the impulsivity measure. RESULTS: Similar rates of impulsivity were found in all three of these types of disorder, and this was little different from the rate found in the women selected randomly from the general population. However, among those with comorbid disorder there was more impulsivity, and the more comorbid disorders found, the higher the proportion with problems of impulsivity. CONCLUSIONS: Because those in treatment facilities are more likely to have other comorbid disorders (Berkson's bias), findings derived from observations of women with bulimia who are in treatment may be compromised by selection bias and may have limited applicability to those with the disorder who are not in treatment.

Adolescent↗
PubMed1996

Why do many ruminal bacteria die and lyse so quickly?

Studies using 15N have indicated that as much as 50% of the microbial mass turns over before N passes to the lower gut, and this N recycling significantly decreases the availability of microbial protein. Protozoa digest bacteria and smaller protozoa, but bacterial protein can turn over even if protozoa are not present. Fibrobacter succinogenes cultures lyse even when they are growing, and the lysis rate is independent of growth rate. When extracellular sugar is depleted, F. succinogenes secretes an extracellular proteinase that inactivates the autolysins. This method of autolytic regulation decreases the turnover of stationary cells. Bacteriophage and anaeroplasma can cause lysogeny, but, as yet, there is little proof that these processes are important determinants of bacterial turnover in vivo. Dietary manipulations (e.g., salt feeding and particle size reduction) that increase liquid and solid dilution rates can increase bacterial flow by decreasing bacterial residence time and turnover. Some dead ruminal bacteria are able to maintain their cellular integrity, and the ratio of dead to live cells in ruminal fluid may be as great as 10:1. Bacterial survival appears to be at least partially explained by the method of sugar transport. When bacteria rely solely on mechanisms of ion-coupled sugar symport, an energized membrane is necessary for the reinitiation of growth. If group translocation (phosphotransferase system) is the mechanisms of transport, uptake can be driven by phosphoenolpyruvate, and an energized membrane and the storage of intracellular reserve materials are not an absolute criteria for survival. In some cases, N deprivation accelerates death. When Prevotella ruminicola was limited for N under conditions of excess energy, methylglyoxal production caused a rapid decrease in viability. The impact of bacterial death in the rumen is not clear-cut. If the rate of fermentation is zero-order with respect to cell concentration (substrate-limited), cell death would have little impact on digestion.

Animals↗
PubMed1995

Telephone support for pregnant women: outcome in late pregnancy.

AIM: The aim of the study was to test the psychosocial benefits of a telephone support program for pregnant women. METHOD: Randomised controlled trial. The study sample were women recruited from an antenatal clinic and general practice surgeries who were less than 20 weeks gestation and either single or in a relationship where the partner was unemployed. Women in the intervention group received weekly telephone calls throughout their pregnancy. All women were interviewed initially and at 34 weeks gestation. There were 66 women in the control group and 65 women in the intervention group. RESULTS: The intervention and control groups did not differ significantly on the psychosocial measures at baseline. Comparisons at 34 weeks were made by analysis of covariance using the baseline scores. The intervention group at 34 weeks had lower stress scores than the control group (means 16.5 vs 18.4, p = 0.02), lower trait anxiety (means 35.2 vs 39.4, p = 0.04) and less depressed mood (means 6.6 vs 8.1, p = 0.02). Self esteem was higher for the intervention group (means 34.9 vs 32.5, p = 0.008). The intervention failed to alter smoking but the intervention women did report more use of community resources (p = 0.02) and were less likely to skip meals (p = 0.03). CONCLUSION: A low cost health promotion program of telephone support during pregnancy can significantly improve a woman's psychosocial status during pregnancy.

Adult↗
PubMed1995

Adverse parenting and other childhood experience as risk factors for depression in women aged 18-44 years.

65 women who had experienced a recent major depressive disorder, and 81 women who had never been depressed, were recruited from a community probability sample. The two groups of women were compared with regard to a number of childhood experiences, including parenting style, which was assessed with the Parental Bonding Instrument (PBI). When all the childhood factors were considered simultaneously in a logistic regression analysis, only low maternal care was significantly associated with recent depressive episodes. Low maternal care increased the risk of recent major depression approximately 4-fold and the estimate of the population attributable risk was 35%. These findings give further weight to the contention that adverse parenting in childhood, particularly a maternal parenting style typified by low care, is a significant risk factor for adult depression.

Adolescent↗
PubMed1995

The effect of carbohydrates on the expression of the Prevotella ruminicola 1,4-beta-D-endoglucanase.

The beta-1,4-endoglucanase of the ruminal bacterium, Prevotella ruminicola B14, hydrolysed carboxymethylcellulose and barley glucan but not xylan or mannan. Endoglucanase activity was present in 88- and 82-kDa proteins, and there was at least a 20-fold variation in endoglucanase activity when P. ruminicola B14 was grown on different sugars. The highest activities were observed with mannose, cellobiose or xylose and little activity was observed with sucrose, arabinose or rhamnose, P. ruminicola B14 also had significant xylanase and mannanase activities, but these activities were present in proteins that had lower molecular masses than the endoglucanase and these proteins did not cross-react with antibody made against the endoglucanase. Mannanase activity has a similar pattern of expression to the endoglucanase, while the xylanase was not induced or repressed by the same sugars or combinations of sugars. The xylanase activity was greatest when xylan was the energy source for growth, but xylose was a very poor inducer of xylanase activity.

Animals↗
PubMed1995

The acute effects of oral ethanol on the hypothalamic-pituitary-adrenal axis in normal human subjects.

OBJECTIVE: To evaluate the acute effects of oral ethanol on the hypothalamic-pituitary-adrenal axis in normal human subjects and, in particular, to examine the effect of background alcohol intake and gastrointestinal side-effects on this response. DESIGN: Plasma ethanol, cortisol, ACTH, corticotrophin-releasing hormone (CRH) and AVP were measured half-hourly for 4 hours following 1.1 ml/kg of 95% ethanol or placebo in a cross-over study. At least one week elapsed between each procedure. SUBJECTS: Twelve healthy non-alcoholic volunteers with a wide range of background alcohol intakes. MEASUREMENTS: Peptide hormones were measured by radioimmunoassay, cortisol by ELISA and blood ethanol by headspace gas chromatography. Results are expressed as mean +/- SEM. RESULTS: Blood ethanol levels peaked at one hour post ethanol ingestion. Three subjects developed significant gastrointestinal (GI) side-effects, with two vomiting and one experiencing moderate to severe nausea. There was no difference between peak blood ethanol levels in the groups with and without GI side-effects (34.5 +/- 2.4 mmol/l vs 34.3 +/- 1.7 mmol/l respectively). ACTH and cortisol rose in those subjects who experienced GI side-effects (P < 0.0001 for each). The remaining subjects had a tendency for ACTH and cortisol to be higher on the placebo day. The group with GI side-effects following ethanol administration had a significant rise in AVP (P < 0.02) that was synchronous with ACTH and cortisol. No consistent alcohol related changes were seen in peripheral CRH levels, although there was a significant increase over time on both active and placebo days (P < 0.0001). In the group with no GI side-effects, AVP did not significantly fall in the first half hour following ethanol, while a significant fall did occur following placebo (P < 0.05). Plasma renin activity was, however, increased by ethanol (P < 0.05). The background alcohol intake of the group with GI side-effects was significantly lower than the group without (18 +/- 7 vs 235 +/- 51 g/week, P < 0.05), but no hormonal response was seen in two subjects with a relatively low alcohol intake (< 100 g/week) who did not experience GI side-effects. CONCLUSION: Intoxicating levels of ethanol per se do not result in activation of the hypothalamic-pituitary-adrenal axis in humans. However, gastrointestinal side-effects induced by the ethanol do result in such activation, which appears to be mediated by AVP as the dominant ACTH secretagogue. One of the factors which influences the blood ethanol level at which GI side-effects occur appears to be background alcohol intake.

Adrenocorticotropic Hormone↗