Biomedical subjects

J E Wells

Publications and source records attributed to J E Wells.

At least 55 records · Page 3Linked to original sources

PubMed1995

Adoption as a risk factor for mental disorders.

Although adoption has been viewed as a risk factor for mental disorders in children and adolescents, few studies have investigated this association in adults. To address this question, we analyzed data from a random community sample of adults where the presence of adoption in the first year of life was systematically noted and where the presence of lifetime mental disorders was determined by structured interview. In comparison to individuals raised by both biological parents, adoption was strongly associated with a history of childhood conduct disorder, antisocial personality and drug abuse or dependence. Adoption may thus be a risk factor for these mental disorders.

Adolescent↗

PubMed1995

Cellodextrin efflux by the cellulolytic ruminal bacterium Fibrobacter succinogenes and its potential role in the growth of nonadherent bacteria.

When glucose or cellobiose was provided as an energy source for Fibrobacter succinogenes, there was a transient accumulation (as much as 0.4 mM hexose equivalent) of cellobiose or cellotriose, respectively, in the growth medium. Nongrowing cell suspensions converted cellobiose to cellotriose and longer-chain cellodextrins, and in this case the total cellodextrin concentration was as much as 20 mM (hexose equivalent). Because cell extracts of glucose- or cellobiose-grown cells cleaved cellobioise and cellotriose by phosphate-dependent reactions and glucose 1-phosphate was an end product, it appeared that cellodextrins were being produced by a reversible phosphorylase reaction. This conclusion was supported by the observation that the ratio of cellodextrins to cellodextrins with one greater hexose [n/(n + 1)] was approximately 4, a value similar to the equilibrium constant (Keq) of cellobiose phosphorylase (J. K. Alexander, J. Bacteriol. 81:903-910, 1961). When F. succinogenes was grown in a cellobiose-limited chemostat, cellobiose and cellotriose could both be detected, and the ratio of cellotriose to cellobiose was approximately 1 to 4. On the basis of these results, cellodextrin production is an equilibrium (mass action) function and not just an artifact of energy-rich cultural conditions. Cellodextrins could not be detected in low-dilution-rate, cellulose-limited continuous cultures, but these cultures had a large number of nonadherent cells. Because the nonadherent cells had a large reserve of polysaccharide and were observed at all stages of cell division, it appeared that they were utilizing cellodextrins as an energy source for growth.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1995

The cellular location of Prevotella ruminicola beta-1,4-D-endoglucanase and its occurrence in other strains of ruminal bacteria.

Prevotella ruminicola B(1)4, TC1-1, TF1-3, and TS1-5 all produced immunologically cross-reacting 88- and 82-kDa carboxymethyl cellulases (CMCases). P. ruminicola 23, 118B, 20-63, and 20-78 had much lower CMCase activities, and Western blots (immunoblots) showed no cross-reaction with the B(1)4 CMCase antiserum. Fibrobacter succinogenes S85 and Selenomonas ruminantium HD4 and D produced CMCase, but these enzymes were smaller and did not cross-react with the B(1)4 CMCase antiserum. The B(1)4 CMCase antiserum inhibited the B(1)4, TC1-1, TF1-3, and TS1-5 CMCase activities and agglutinated these cells, but it had no effect on the other strains or species. On the basis of these results, the B(1)4 CMCase is a strain-specific enzyme that is located on the outside surface of the cells. P. ruminicola B(1)4 cultures, grown on sucrose, did not have significant CMCase activity, but these cells could bind purified 88- and 82-kDa CMCase but not 40.5-kDa CMCase. Because the 40.5-kDa CMCase is a fully active, truncated form of the CMCase, it appears that the N-terminal domain of the 88-kDa B(1)4 CMCase anchors the CMCase to the cells. Cells grown on cellobiose produced at least 10-fold more CMCase than the sucrose-grown cells, and the cellobiose-grown cells could only bind 15% as much CMCase as sucrose-grown cells. Virtually all of the CMCase activity of exponentially growing cultures was cell associated, but CMCase activity was eventually detected in the culture supernatant. On the basis of the observation that the 88-kDa CMCase was gradually converted to the 82-kDa CMCase when cultures reached the stationary phase without a change in specific activity, it appears that the 82-kDa protein is probably a proteolytic degradation product of the 88-kDa CMCase.

Animals↗

PubMed1995

Detection of obstructive uropathy in the fetus: predictive value of sonographic measurements of renal pelvic diameter at various gestational ages.

OBJECTIVE: The goal of our study was to analyze the fetal renal pelvic diameters measured sonographically at several gestational intervals in live-born neonates subsequently found to have either obstructive uropathy or normal kidneys. This information will improve the efficacy of sonography in the diagnosis of obstructive uropathy. SUBJECTS AND METHODS: From an ongoing prospective study assessing the significance of fetal renal pelvic diameters of 4 mm or more at obstetric sonography, the findings in 29 obstructed kidneys in 24 babies were compared with the findings in 380 kidneys from 233 infants who had no obstruction. Twenty-three infants had unilateral obstruction of the ureteropelvic junction, two had unilateral renal obstruction at the ureterovesical junction, one had posterior urethral valves and in addition had both kidneys obstructed because of obstruction at the ureterovesical junction, one kidney was obstructed because of megaloureter, and one kidney was obstructed because of obstruction in a duplex collecting system. Obstruction was identified on nephrostograms, excretory urograms, or radionuclide renograms. The sonographic findings were compared at three gestational age ranges: 16-23 weeks' gestation, 24-30 weeks' gestation, and 31-40 weeks' gestation. The progression of pelvic dilatation in both groups (12 obstructed and 86 unobstructed) was analyzed for the subset of kidneys examined in all three time periods. RESULTS: At 16-23 weeks' gestation, the difference in mean pelvic diameter between obstructed and unobstructed kidneys was not statistically significant, but the difference between obstructed and unobstructed groups at 24-30 weeks' and 31-40 weeks' gestation was significant (p < .001). Renal pelvic diameter showed a much greater rise in diameter through pregnancy in the obstructed group than in the unobstructed group (p < .0003). The sensitivity of the cutoff point of 4-mm renal pelvic diameter for detecting obstruction was 76% before 23 weeks' gestation, including kidneys with a marked decrease in function postnatally; the sensitivity of a 10-mm cutoff point at 16-23 weeks' gestation was 12%. The likelihood that a fetus had renal obstruction increased with increasing diameter of the fetal renal pelvis in all three time periods. CONCLUSION: Kidneys with significant obstruction postnatally may have no dilatation of the renal pelvis before 23 weeks' gestation. Most obstructed kidneys had pelvic diameters of less than 10 mm before 23 weeks' gestation. During pregnancy, renal pelvic diameter increases at a greater rate in kidneys that later are shown to be obstructed than in those that are not obstructed.

Female↗

PubMed1995

Disruptions in childhood parental care as risk factors for major depression in adult women.

OBJECTIVE: The aim of this study was to examine the influence of different types of disruptions in childhood parental care before the age of 15 years as risk factors for major depression in women aged 18 to 44 years. The types of disruptions studied were parental death, parental separation or divorce, other types of loss (i.e. adoption, foster-care, etc.), and prolonged separation from both parents. Potential confounding factors were also examined. METHOD: The data were obtained from a community probability sample. Caseness was determined by the use of the Diagnostic Interview Schedule (DIS) and both the current (one month) and lifetime prevalence periods were considered. Logistic regression was used to model the influence of each factor, singly and adjusted for the influence of other factors, on the risk for major depression. RESULTS: It was found that in this population 17% had experienced some type of parental loss (parental death 4%, separations/divorce 10% and other types of loss 3%) and 11% had experienced prolonged separation from both parents. Parental loss was significantly associated with lifetime depression, but this effect was no longer significant when adjusted for other factors. However, prolonged separation from both parents was associated with an increased risk of current and lifetime depressive episodes of approximately three to fourfold, even when the risk was adjusted for other factors. CONCLUSIONS: The results of this study suggest that prolonged separation from both parents has a stronger association with current or lifetime depression in women than do parental death, separation/divorce and other types of loss. Prolonged separation may be a marker for other risk factors and may not be a risk factor on its own.

Adolescent↗

PubMed1994

Long term follow up of patients with IgA nephropathy.

AIM: To assess the long term outcome of patients with IgA nephropathy. METHOD: The outcome of 151 patients (120 male; mean age 32.5, median age 29.6, SD 15.4 years; 146 Caucasian) with biopsy-proven IgA nephropathy. The patients were enrolled between 30 April 1973 and 21 August 1992. RESULTS: Ninety-five (63%) of the patients presented with microscopic haematuria, with or without proteinuria and/or renal insufficiency. At presentation renal insufficiency was present in 34% and hypertension in 48% of patients. During a mean follow up period of 63.3 months (range 0-233 months) 12 patients have reached end stage renal failure, five have died of a nonrenal cause and 25 were lost to follow up. The actuarial renal survival rate was 92.6% at five years and 91.1% at both 10 and 15 years. A significantly poorer renal survival rate was seen in those patients with a plasma creatinine > or = 0.12 mmol/L, hypertension, a serum albumin of < 35 g/L, or a 24 hour urinary albumin excretion > or = 1.0 g at presentation, and this became apparent within the first few years of follow up. CONCLUSIONS: The long term outcome of IgA nephropathy is better than previously reported. Those patients with a poor prognosis can be identified with considerable certainty at presentation.

Actuarial Analysis↗

PubMed1994

Perceived barriers to care in St. Louis (USA) and Christchurch (NZ): reasons for not seeking professional help for psychological distress.

This paper examines perceived barriers to mental health care reported in two very similar community surveys in two cities that are not only on opposite sides of the world but that differ substantially in their health care systems, their size, and their mix of ethnic groups, namely, St. Louis in the United States and Christchurch in New Zealand. Respondents were asked about mental health care ever received, any failure to seek care when required, and symptoms of 14 psychiatric disorders according to DSM-III. The frequency with which respondents reported not seeking care and the popularity of specific reasons for not seeking care were almost identical in the two sites. A common reason offered for not seeking care was doubt about the need for professional help; this appeared to be particularly common for people with alcohol disorder. Respondents who said that they had failed to seek care when needed gave reasons that were mainly attitudinal, such as believing they should be strong enough to cope without professional help. Structural characteristics of services such as cost, times open, and travel distance were given less often. Sociodemographic factors had small or negligible effect on care seeking.

Adaptation, Psychological↗

PubMed1994

Bulimia comorbidity in the general population and in the clinic.

This study compares rates of comorbidity of lifetime psychiatric disorder in a clinical sample of women with bulimia, with general population base rates, and with rates of comorbidity among bulimic women in the general population. Eighty-four per cent of the clinical sample of bulimic women had a lifetime affective disorder, and 44% a lifetime alcohol or drug disorder. These rates of disorder were significantly higher than the base rates in the general population. Bulimic women in the general population also had more affective and substance-use disorders than the general population base rates, but the rates of these disorders were lower than found in the clinical sample. In the general population, quite similar rates of other disorders including generalized anxiety, panic, phobia and obsessive-compulsive disorder, are found among those with bulimia, substance-use disorder and depression. Furthermore, among those with depression and substance-use disorder in the general population, rates of eating disorder are comparable. Rather than suggesting a specific relationship between bulimia and either depression or substance-use disorder, the data from this study suggest that the presence of any disorder is associated with a non-specific increase in the likelihood of other psychiatric disorder.

Adolescent↗

PubMed1994

Lithium associated thyrotoxicosis: a report of 14 cases, with statistical analysis of incidence.

OBJECTIVE: Lithium is known to cause goitre and hypothyroidism, and has been associated less commonly with hyperthyroidism. We report a series of 14 patients with lithium associated thyrotoxicosis (LiAT), and have used epidemiological data to assess the association between long-term lithium treatment and the development of thyrotoxicosis. DESIGN: Information for this retrospective study was obtained from records of patients attending the thyroid clinic between 1973 and 1991. Statistical analysis of the association between long-term lithium treatment and incidence of thyrotoxicosis was made using local thyrotoxicosis incidence figures and lithium prescription data. MEASUREMENTS: Investigations included 99mTc pertechnetate thyroid scans, and blood analyses to measure serum T4, serum T3, free T4 index, and thyroid microsomal and thyroglobulin antibody titres. RESULTS: During the 18-year period there were 14 patients with LiAT. This number of cases of thyrotoxicosis occurring in patients on lithium was more than three times greater than that predicted from local thyrotoxicosis incidence rates (P < 0.05). Scintiscans were obtained for 13 patients: 8 had toxic diffuse goitre, 2 toxic multinodular goitre, 1 toxic uninodular goitre, and 2 had a lack of visualization consistent with 'painless thyroiditis'. Nine patients received a course of carbimazole and 6 of these remain in remission. Six patients have received 131I therapy. Eight patients have become hypothyroid at follow-up (5 post 131I, 1 following a course of carbimazole, and the 2 with 'painless thyroiditis'). CONCLUSIONS: Statistical analysis has shown that long-term lithium therapy is associated with an increased risk of thyrotoxicosis. LiAT is a heterogeneous condition with differing underlying thyroid pathologies and the mechanisms remain uncertain. The management of LiAT should initially be with antithyroid medication, and 131I therapy should be given only to patients who do not obtain long-term remission.

Adolescent↗

PubMed1994

Ability of Acidaminococcus fermentans to oxidize trans-aconitate and decrease the accumulation of tricarballylate, a toxic end product of ruminal fermentation.

Mixed ruminal bacteria convert trans-aconitate to tricarballylate, a tricarboxylic acid which chelates blood divalent cations and decreases their availability (J. B. Russell and P. J. Van Soest, Appl. Environ. Microbiol. 47:155-159, 1984). Decreases in blood magnesium in turn cause a potentially fatal disease known as grass tetany. trans-Aconitate was stoichiometrically reduced to tricarballylate by Selenomonas ruminantium, a common ruminal bacterium in grass-fed ruminants (J. B. Russell, Appl. Environ. Microbiol. 49:120-126, 1985). When mixed ruminal bacteria were enriched with trans-aconitate, a trans-aconitate-oxidizing bacterium was also isolated (G. M. Cook, F. A. Rainey, G. Chen, E. Stackebrandt, and J. B. Russell, Int. J. Syst. Bacteriol. 44:576-578, 1994). The trans-aconitate-oxidizing bacterium was identified as Acidaminococcus fermentans, and it converted trans-aconitate to acetate, a nontoxic end product of ruminal fermentation. When S. ruminantium and A. fermentans were cocultured with trans-aconitate and glucose, tricarballylate never accumulated and all the trans-aconitate was converted to acetate. Continuous-culture studies (dilution rate, 0.1 h-1) likewise indicated that A. fermentans could outcompete S. ruminantium for trans-aconitate. When mixed ruminal bacteria were incubated in vitro with 10 mM trans-aconitate for 24 h, 45% of the trans-aconitate was converted to tricarballylate. Tricarballylate production decreased 50% if even small amounts of A. fermentans were added to the incubation mixes (0.01 mg of protein per mg of mixed bacterial protein). When A. fermentans (2 g of bacterial protein) was added directly to the rumen, the subsequent conversion of trans-aconitate to tricarballylate decreased 50%, but this effect did not persist for more than 18 h.(ABSTRACT TRUNCATED AT 250 WORDS)

Aconitic Acid↗

PubMed1993

Lead exposure during recreational use of small bore rifle ranges.

AIMS: Following detection of symptomatic lead toxicity in two users of an indoor small bore rifle range, we studied users of several similar facilities to determine if significant recreational lead exposure occurred. METHOD: Red cell lead levels were measured at the end of a six month (winter) indoor shooting season and prior to commencement of shooting in the following year. Lead levels in air and dust sampled at one range were also measured. RESULTS: REd cell lead levels were elevated at the end of season (mean 2.64 mumol/L) and lower (mean 1.60 mumol/L) in the preseason samples. The average red cell lead level of the male shooters was 2.4 times normal and is comparable to the levels found in many occupationally exposed groups. Maximum air lead levels were 210 micrograms/m3, more than 2 times the Department of Labour OSH workplace exposure standard TWA of 100 micrograms/m3. Analysis of dust samples showed that dust at this range contained 24% to 36% lead. CONCLUSION: Although the mean time spent shooting was only 70 minutes per week the blood lead levels are similar to those previously reported for full time instructors at pistol ranges. This data confirms that lead exposure in recreational users of indoor small bore rifle ranges is a significant problem.

Adolescent↗

PubMed1993

Variation in the risk of peptic ulcer complications with nonsteroidal antiinflammatory drug therapy.

OBJECTIVE: To assess the risk of perforation or hemorrhage of peptic ulcer on treatment with nonsteroidal antiinflammatory drugs (NSAIDs), both as a class and as individual agents. METHODS: A case-control study of medication histories in 494 patients and 972 matched control subjects. RESULTS: The increase in risk (odds ratio) with NSAID therapy was 5.1 times the risk in controls. The odds ratio for piroxicam was 6.3 (95% confidence interval [CI] 3.3-12.0), as compared with 2.9 for diclofenac, ketoprofen, and sulindac combined (95% CI 2.0-4.2). The effect of other risk factors was also considered, and the adjusted odds ratios were 4.1 for all NSAIDs, 6.4 (95% CI 2.8-15.0) for piroxicam, and 3.3 (95% CI 2.0-5.5) for diclofenac, ketoprofen, and sulindac combined. CONCLUSION: The estimate of overall risk of peptic ulcer complications with NSAIDs is similar to that found in other studies. There appear to be differences in risk between agents.

Adult↗

PubMed1993

Historical assessment of risk factors in screening for osteopenia in a normal Caucasian population.

BACKGROUND: Bone mineral density (BMD) can predict fracture, however, the common use of historical risk factors to predict low BMD is unproven. AIMS: To identify significant historical risk factors for osteopenia. To establish predicting equations for BMD and test their ability to identify those who should be referred for BMD scanning. METHODS: Three hundred and twenty female and 131 male volunteers underwent questionnaire assessment of risk factors and BMD by dual photon absorptiometer at hip and spine. Significant risk factors (P < 0.05) were used to construct a linear regression model to predict BMD. This was cross validated on a second sample of 107 females and 131 males selected from the electoral roll analysing the ability to detect those subjects with BMD in the lower third of the age matched normal range. RESULTS: In women lower BMD at the spine was associated with increased age, decreased weight, smoking, and delayed menarche. Lower femoral BMD was associated with increased age, decreased weight, family history, inactivity, and smoking. In men lower BMD at the lumbar spine was associated with lower weight, and inactivity. Lower BMD at the femur was associated with increased age, decreased weight, family history, and low calcium intake. When cross validated on the second sample, the models produced sensitivity of 86-89% and sensitivity of 25-46%. Referring those with these risk factors could save 10-23% on scanning. Measuring BMD at the site in question remains the only accurate way of assessing an individual's risk of osteopenia.

Adult↗

PubMed1993

Hemorheology and fistula function in home hemodialysis patients following erythropoietin treatment: a prospective placebo-controlled study.

The beneficial effect of correcting anemia in end stage renal failure using recombinant human erythropoietin (rHuEPO) is sometimes complicated by thrombosis of the arteriovenous fistula. This placebo-controlled study investigated the relationship between hemorheological changes caused by rHuEPO and alterations in fistula function and heparin requirements in home hemodialysis patients. Erythropoietin induced a rise in high shear rate blood viscosity, a determinant of blood flow in large vessels. Doppler assessment of brachial artery blood flows, tests of fistula function and heparin requirements were similar in the two patient groups. These findings indicate that rHuEPO treatment of renal anemia resulted in the expected rise in red blood cell mass and blood viscosity although these changes did not cause problems with arteriovenous access or alter fistula function in the short term.

Adult↗

PubMed1992

The premenstrual syndrome: amelioration of symptoms after hysterectomy.

What is the role of the uterus in the aetiology of the premenstrual syndrome (PMS)? Twelve women kept a daily symptom record before and after hysterectomy. Psychological and physical symptom patterns were analysed by Fourier analysis and the response to hysterectomy by maximum likelihood ANOVA. Hysterectomy was associated with a 66% reduction in mean premenstrual tension (PMT) severity for both psychological and physical symptoms (p less than 0.005). The milder symptoms appeared unrelated to post-operative changes in health or ovarian function. Seven women experienced mood-related PMT in every pre-hysterectomy cycle; the persistence of unfailing mood-related PMT in one of these women after hysterectomy suggests that her symptoms were hormonally controlled and the loss of regular PMT in the other six women suggests that a uterine factor, or psychological factors associated with the menstrual cycle were implicated. We conclude that a uterus is not essential for the expression of PMT, but that its removal often results in the amelioration of symptoms.

Adult↗

PubMed1992

The effect of celiprolol on glomerular filtration rate and renal blood flow in patients with chronic renal impairment and healthy volunteers.

A double-blind, placebo controlled study investigated the effects of celiprolol, 200 mg daily for 7 days, on glomerular filtration rate (GFR) and estimated renal blood flow (ERBF) in eight healthy volunteers and eight patients with chronic renal insufficiency. In healthy volunteers the mean difference in GFR was 4.8 ml min-1 (95% CI -8.2 to 17.7 ml min-1) and the mean difference in ERBF was 49.8 ml min-1 (95% CI -47.5 to 147 ml min-1) after celiprolol. In patients with chronic renal insufficiency the mean difference in GFR was -2.1 ml min-1 (95% CI -64.6 to 65.8 ml min-1). The study had sufficient power to detect a 15% change in GFR for normals and 10% for patients, and for ERBF, changes of 14% and 23% were detectable. Celiprolol at a dose of 200 mg daily for 7 days can be used in patients with chronic renal insufficiency without adversely affecting GFR or ERBF.

Adolescent↗

PubMed1992

Long-term effects of intrafamilial sexual abuse in childhood.

This study reports results from follow-up interviews with 301 women aged 18-44 years who were first identified 2 years earlier in a cross-sectional study of 1498 adults in the general population of the city of Christchurch, New Zealand. The prevalence of intrafamilial sexual abuse was 13%. This incestuous sexual abuse in childhood was associated with an increase in many adult mental symptoms, particularly symptoms of depression, bulimia and generalized anxiety. In this community study the consequences associated with sexual abuse within the family appear to be widespread and not very specific, and show as additional comorbidity rather than as increased severity within a disorder. These results do not support the strong direct causal effects postulated in some theories derived from clinical studies.

Adolescent↗

PubMed1992

Lidocaine for the prevention of pain due to injection of propofol.

Propofol has a high incidence of pain with injection, particularly into small veins. We sought to determine whether concomitant administration of lidocaine could prevent this pain. In a randomized double-blind trial, 368 women were allocated to one of four groups to receive 19 mL of propofol mixed with either 1 mL of 0.9% saline, 1 mL of 0.5% (5 mg) lidocaine, 1 mL of 1% (10 mg) lidocaine, or 1 mL of 2% (20 mg) lidocaine. The pain of injection was scored as none, mild, moderate, or severe. There was a significant reduction in the overall incidence of pain from 73% with saline to 32% with 20 mg lidocaine. A highly significant negative dose-response relationship between the dose of lidocaine and the severity of pain was demonstrable, both at induction of anesthesia and as recalled in the recovery room (P less than 0.001 for both). Lidocaine (20 mg IV) will significantly reduce the incidence and severity of pain with propofol injection, but about 6% of patients will still suffer unpleasant pain if the dorsum of the hand is used.

Adult↗