Oxygen consumption, ammonia excretion and protein use in response to thermal changes in juvenile Atlantic salmon Salmo salar.

Experiments were designed to examine the effects of various temperature challenges on oxygen consumption and ammonia excretion rates and protein utilization in juvenile Atlantic salmon Salmo salar. Fish acclimated to 15 degrees C were acutely and abruptly exposed to either 20 or 25 degrees C for a period of 3 h. To simulate a more environmentally relevant temperature challenge, a third group of fish was exposed to a gradual increase in temperature from 15 to 20 degrees C over a period of 3 h (c. 1.7 degrees C h(-1)). Oxygen consumption and ammonia excretion rates were monitored before, during and after the temperature shift. From the ammonia excretion and oxygen consumption rates, protein utilization rates were calculated. Acute temperature changes (15-20 degrees C or 15-25 degrees C) caused large and immediate increases in the oxygen consumption rates. When the temperature was gradually changed (i.e. 1.7 degrees C h(-1)), however, the rates of oxygen consumption and ammonia excretion were only marginally altered. When fish were exposed to warmer temperatures (i.e. 15-20 degrees C or 15-25 degrees C) protein use generally remained at pre-exposure (15 degrees C) levels. A rapid transfer back to 15 degrees C (20-15 degrees C or 25-15 degrees C) generally increased protein use in S. salar. These results indicate that both the magnitude and the rate of temperature change are important in describing the physiological response in juvenile salmonids.

Percutaneous screw fixation versus conservative treatment for fractures of the waist of the scaphoid: a prospective randomised study.

We randomly allocated 60 consecutive patients with fractures of the waist of the scaphoid to percutaneous fixation with a cannulated Acutrak screw or immobilisation in a cast. The range of movement, the grip and pinch strength, the modified Green/O'Brien functional score, return to work and sports, and radiological evidence of union were evaluated at each follow-up visit. Patients were followed sequentially for one year. Those undergoing percutaneous screw fixation showed a quicker time to union (9.2 weeks vs 13.9 weeks, p < 0.001) than those treated with a cast. There was a trend towards a higher rate of nonunion in the non-operative group, although this was not statistically significant. Patients treated by operation had a more rapid return of function and to sport and full work compared with those managed conservatively. There was a very low complication rate. We recommend that all active patients should be offered percutaneous stabilisation for fractures of the waist of the scaphoid.

Genotypic variation in Pneumocystis jirovecii isolates in Britain.

BACKGROUND: Pneumocystis jirovecii is the cause of Pneumocystis pneumonia (PCP) in immunosuppressed humans. Asymptomatic colonisation with P jirovecii may occur in patients with minor immunosuppression or chronic lung disease. The aim of this study was to describe the molecular epidemiology of P jirovecii in Britain over a period of 12.5 years. METHODS: Between January 1989 and July 2001 161 samples of P jirovecii were obtained from patients with PCP (n = 119), patients colonised by P jirovecii (n = 35), and from air spora (n = 6). Genotyping of samples was performed at the mitochondrial large subunit rRNA (mt LSU rRNA). RESULTS: Genotype 1 (38%) was the most frequently identified genotype: genotypes 2 (26.6%), 3 (20.3%), and 4 (5%) were less common. Mixed infection (more than one genotype) was identified in 10% of samples. While genotype 1 was the most frequently detected type in both patients with PCP and those colonised by P jirovecii (38% and 42%, respectively), these groups differed in the relatively lower rate of detection of genotype 4 (2% v 17%) and the higher detection of mixed infection in those with PCP (13% v 3%). Detection of specific genotypes of P jirovecii was associated with the patient's place of residence (p = 0.02). There was no association between specific genotypes and severity of PCP as measured by arterial oxygen tension (p = 0.3). CONCLUSIONS: The evidence of clustering of specific genotypes with patient's postcode of residence is consistent with the hypothesis of person to person transmission of P jirovecii via the airborne route. The lack of association between specific mt LSU rRNA genotypes and severity of PCP suggests that this locus is not implicated in the virulence of the organism.

Use of community genetic screening to prevent HFE-associated hereditary haemochromatosis.

HFE-associated hereditary haemochromatosis is a recessive, iron-overload disorder that affects about one in 200 north Europeans and that can be easily prevented. However, genetic screening for this disease is controversial, and so we assessed whether such screening was suitable for communities. Cheek-brush screening for the Cys282Tyr HFE mutation was offered to individuals in the workplace. Outcomes were assessed by questionnaires before and after testing. 11,307 individuals were screened. We recorded no increase in anxiety in individuals who were homozygous for the Cys282Tyr mutation or non-homozygous. Self-reported tiredness before testing was significantly higher in homozygous participants than in non-homozygous participants (chi2 test, p=0.029). Of the 47 homozygous individuals identified, 46 have taken steps to treat or prevent iron accumulation. Population genetic screening for HFE-associated hereditary haemochromatosis can be practicable and acceptable.

Coercion in the treatment of anorexia nervosa: clinical, ethical and legal implications.

Because of its high mortality and treatment resistence, clinicians sometimes invoke the law in aid of retaining their most acutely ill-patients in treatment or re-feeding programs. Depending on the jurisdiction, various laws, including mental health and adult guardianship laws, have been invoked to achieve this objective (Carney, Tait, Saunders, Touyz & Beumont, 2003). Until recently, little was known about the therapeutic impact of coercion on patients (Saunders, 2001, Carney & Saunders 2003), or the relative advantages of different avenues of coercion (Carney, Saunders, Tait, Touyz & Ingvarson 2004). Most obscure of all, however, has been our understanding of the factors influencing clinical decisions within specialist anorexia treatment units regarding which in-patients will be selected for coerced treatment. This paper reports legal and ethical implications of findings from analysis of data gathered from a major Australian specialist anorexia treatment facility over nearly 5 years.

Implementation of HaemScreen, a workplace-based genetic screening program for hemochromatosis.

There is debate as to whether community genetic screening for the mutation(s) causing hereditary hemochromatosis (HH) should be implemented, due to issues including disease penetrance, health economic outcomes, and concerns about community acceptance. Hemochromatosis is a common preventable iron overload disease, due in over 90% of cases to C282Y homozygosity in the HFE gene. We are, therefore, piloting C282Y screening to assess understanding of genetic information and screening acceptability in the workplace setting. In this program, HaemScreen, education was by oral or video presentation in a group setting. C282Y status was assessed by polymerase chain reaction (PCR) and melt-curve analysis on DNA obtained by cheek-brush sampling. Of eligible participants, 5.8% (1.5-15.8%) attended information and screening sessions, of whom 97.7% (5571 individuals) chose to be tested. Twenty-two C282Y (1 : 253) homozygotes were identified and offered clinical follow-up. There were 638 heterozygotes (1 : 8.7). The determinants for participation have been analyzed in terms of the principles outlined in the Health Belief Model. Widespread screening for HH is readily accepted in a workplace setting, and a one-to-many education program is effective. The level of participation varies greatly and the advertizing and session logistics should be adapted to the specific features of each workplace.

Expression and complexity of the PRT1 multigene family of Pneumocystis carinii.

Pneumocystis carinii has a multigene family, PRT1, that encodes proteins with homology to KEX2-like proteases. PRT1 genes cluster with MSG genes near the telomeres and, like MSG, PRT1 proteins seem to be surface-expressed. The clustering of PRT1 and MSG genes suggested that expression of the two multigene families might be coordinated. Studying gene expression in P. carinii has been hampered by the lack of a culture system, and by lack of clonality in P. carinii populations in naturally infected rats, the host of this fungus. Heterogeneity can be reduced, however, by low-dose intratracheal inoculation, which can produce P. carinii populations dominated by organisms derived from a single progenitor. To study PRT1 expression, nude rats were inoculated with approximately 10 P. carinii each. The clonality of the P. carinii populations from inoculated rats was assessed by analysis of the UCS locus, a site in the genome that is known to be very heterogeneous in naturally infected rats, but nearly homogeneous in rats infected by low-dose intratracheal inoculation. Each of the populations had the same MSG gene at the UCS locus in at least 80 % of the organisms. To investigate PRT1 gene expression, RNA was amplified using primers that amplify numerous PRT1 genes. Seventy-four cloned cDNAs were sequenced, including at least 12 clones from each population of P. carinii. Many differently expressed PRT1 sequences were identified in each population, and a total of 45 different sequences were detected. However, the same PRT1 sequence was present in 15 of 74 plasmids and was found in 3 of the 5 P. carinii populations, suggesting that some PRT1 genes may be either more commonly expressed or expressed at a higher level. These data show that many members of the PRT1 gene family can be expressed in populations of P. carinii derived from few progenitors and suggest that the regulation of this family is different from that governing expression of the MSG gene family.

Asymptomatic carriage of Pneumocystis jiroveci in subjects undergoing bronchoscopy: a prospective study.

BACKGROUND: The opportunistic fungus Pneumocystis jiroveci is a common cause of respiratory infection in immunocompromised patients. By contrast, pneumocystis pneumonia (PCP) occurs only rarely in immunocompetent individuals. Asymptomatic colonisation with P jiroveci has recently been described in patients who are either minimally immunosuppressed or who have underlying lung disorders such as bronchiectasis. We sought to determine the prevalence of asymptomatic colonisation by P jiroveci in a cohort of adult patients undergoing diagnostic bronchoscopy. METHODS: A prospective observational cohort study was performed in patients who required bronchoscopy and bronchoalveolar lavage (BAL) as part of their routine clinical assessment. All the samples underwent standard microbiological analysis and a Grocott methenamine silver stain was performed where clinically indicated to detect the presence of P jiroveci. Polymerase chain reaction for detection of P jiroveci specific DNA was also performed. RESULTS: Ninety three consecutive BAL fluid samples were analysed, 17 (18%) of which contained P jiroveci DNA. Of the potential predictors examined, only glucocorticoid use was significantly associated with detectable P jiroveci DNA. Eighteen patients were receiving oral glucocorticoids (equivalent to >20 mg/day prednisolone) at the time of bronchoscopy, of whom eight (44%) had detectable P jiroveci DNA. In contrast, P jiroveci was detected in only nine of 75 patients (12%) who were not receiving glucocorticoids (difference between proportions 32%, 95% CI 8 to 57; p=0.004, two tailed Fisher's exact test). CONCLUSIONS: P jiroveci colonisation, as determined by detection of P jiroveci DNA in BAL fluid, is common in HIV negative patients with primary respiratory disorders undergoing bronchoscopy and BAL. The higher prevalence in patients receiving corticosteroids suggests that oral glucocorticoid therapy is an independent risk factor for colonisation. In contrast, underlying lung cancer or COPD did not appear to be risk factors.

Prevalence of gastrointestinal diseases in two British national birth cohorts.

BACKGROUND: Few studies have investigated the prevalence of multiple gastrointestinal diseases in the general British population. AIM: To examine the prevalence of Crohn's disease (CD), ulcerative colitis (UC), irritable bowel syndrome (IBS), gall stones (GS), and peptic ulcer disease (PUD). SUBJECTS: The 1970 British Cohort Study (BCS70) and the National Child Development Study (NCDS) are two one week national birth cohorts born in 1970 and 1958, respectively. All cohort members living in Great Britain were interviewed in 1999/2000. METHODS: The prevalence rates of the five diseases were calculated, and associations with sex and childhood social class were investigated using logistic regression. RESULTS: At age 30 years, the prevalence rates per 10,000 (95% confidence interval (CI)) in the 1970 and 1958 cohorts, respectively, were: CD 38 (26-49), 21 (13-30); UC 30 (20-41), 27 (18-37); IBS 826 (775-877), 290 (267-330); GS 88 (71-106), 78 (62-94); and PUD 244 (214-273), 229 (201-256). There was a significantly higher proportion with CD (p=0.023) and IBS (p=0.000) in the 1970 cohort compared with the 1958 cohort at age 30 years. Comparing the cohorts in the 1999/2000 sweep, UC, GS, and PUD were significantly (p=0.001, p=0.000, p=0.000) more common in the 1958 cohort. There was a statistically significant trend for a higher risk of GS with lower social class in both cohorts combined (p=0.027). CONCLUSION: The study indicates an increasing temporal trend in the prevalence of CD and suggests a period effect in IBS, possibly due to adult life exposures or variation in recognition and diagnosis of IBS.

Pneumocystis carinii pneumonia with pleurisy, platypnoea and orthodeoxia.

We present a patient who collapsed with chest pain and dyspnoea on a transatlantic flight. She was found to have Pneumocystis carinii pneumonia (PCP) and human immunodeficiency virus infection. Platypnoea and orthodeoxia, which have not been previously reported in association with PCP, were major features of her illness. The PCP predominantly affected her lung bases and it is likely that gravity increased intrapulmonary blood flow through poorly ventilated lung bases with failure of pulmonary vasoconstriction to increase upper zone perfusion, exacerbating desaturation on sitting up. The partial DNA sequence of the infecting P carinii was identical to previously described isolates.

Siblings and the risk of inflammatory bowel disease.

BACKGROUND: Environmental exposures in early life have been implicated in the aetiology of inflammatory bowel disease (IBD). Siblings are used as proxy markers to characterize patterns of exposure relevant to the risk of IBD. METHODS: Some 15,823 patients with ulcerative colitis and 12,668 with Crohn disease from the Swedish In-patient Register were compared with 79,546 and 63,035 controls, respectively, in a case-control study. Multiple logistic regression was used to investigate associations with older and younger siblings, and adjustment was made for sex, year of birth, mother's age, region and, additionally, father's social class. RESULTS: Older siblings are associated with a graded increased risk for ulcerative colitis (P for trend <0.001) and an adjusted odds ratio of 1.15 (95% CI 1.07-1.24) for three or more older siblings. Younger siblings are associated with a graded decreased risk for Crohn disease (P for trend <0.001) with an adjusted odds ratio of 0.83 (0.76-0.90) for three or more younger siblings. The greatest protective association with Crohn disease was seen for younger siblings born within 2 years of the subject. Older maternal age is independently associated with a decreased risk of Crohn disease, with P for trend <0.001. Additional adjustment for social class did not substantially alter the results. CONCLUSIONS: Having siblings is associated with the risk and phenotype of developing IBD, possibly through their influence on patterns of antigenic exposure in early life. The association of maternal age with Crohn disease may reflect age-related changes in maternal immune profile.

Redislocation of the shoulder during the first six weeks after a primary anterior dislocation: risk factors and results of treatment.

BACKGROUND: After an anterior dislocation, shoulder instability may occur with disruption of the soft-tissue or osseous restraints, leading to early redislocation. The aim of the present study was to clarify the risk factors for this complication within the first six weeks after a first-time anterior traumatic dislocation and to assess the outcome of treatment with immediate operative stabilization. METHODS: A three-year, prospective, observational cohort study of 538 consecutive patients with a first-time anterior dislocation of the shoulder was carried out. Reassessment of shoulder function was performed at a dedicated shoulder clinic, and suspected early redislocations were assessed with additional radiographs. All medically fit patients with a confirmed acute redislocation were treated with repeat closed reduction under anesthesia. Patients with unstable reductions were treated operatively. Functional and radiographic assessment of outcome was carried out during the first year after dislocation. RESULTS: Seventeen (3.2%) of the 538 patients sustained an early redislocation within the first week after the original dislocation. Patients at increased risk of early redislocation included those who sustained the original dislocation as the result of a high-energy injury (relative risk = 13.7), those who had a neurological deficit (relative risk = 2.0), those in whom a large rotator cuff tear occurred in conjunction with the dislocation (relative risk = 29.8), those in whom the original dislocation was associated with a fracture of the glenoid rim (relative risk = 7.0), and those who had a fracture of both the glenoid rim and the greater tuberosity (relative risk = 33.5). Following operative reconstruction, the outcome at one year after the injury was favorable in terms of function, general health, and radiographic findings. None of the patients had a redislocation or symptoms of instability at one year. CONCLUSION: All patients who have substantial pain, a visible shoulder deformity, or restriction of movement at one week after reduction of a first-time dislocation should be evaluated with repeat radiographs to exclude a redislocation. Patients in whom this complication develops usually have either (1) severe disruption of the soft-tissue envelope due to a large rotator cuff tear or (2) disruption of the normal osseous restraints to dislocation due to either an isolated fracture of the glenoid rim or fractures of both the glenoid rim and the greater tuberosity. Early operative stabilization is justified for patients in whom the dislocation is associated with these coexisting conditions and who have evidence of gross instability.

Absence of mutations associated with sulfa resistance in Pneumocystis carinii dihydropteroate synthase gene from non-human primates.

The dihydropteroate synthase (DHPS) gene from Pneumocystis carinii isolated from non-human primates was amplified using a polymerase chain reaction (PCR) and sequenced to analyse point mutations associated with sulfa resistance. P. carinii DHPS gene amplification was obtained from eight lung samples from five New World primate species and one Old World primate species. None of the animals had been exposed to sulfa drugs and only the wild-type P. carinii DHPS sequence at codons 55 and 57 was observed. These data support the hypothesis that high rates of DHPS mutants in P. carinii f. sp. hominis have arisen with increased use of sulfa drugs for P. carinii pneumonia prophylaxis.

Small intestinal enteropathy with epithelial IgG and complement deposition in children with regressive autism.

We have reported lymphocytic colitis in children with regressive autism, with epithelial damage prominent. We now compare duodenal biopsies in 25 children with regressive autism to 11 with coeliac disease, five with cerebral palsy and mental retardation and 18 histologically normal controls. Immunohistochemistry was performed for lymphocyte and epithelial lineage and functional markers. We determined the density of intraepithelial and lamina propria lymphocyte populations, and studied mucosal immunoglobulin and complement C1q localisation. Standard histopathology showed increased enterocyte and Paneth cell numbers in the autistic children. Immunohistochemistry demonstrated increased lymphocyte infiltration in both epithelium and lamina propria with upregulated crypt cell proliferation, compared to normal and cerebral palsy controls. Intraepithelial lymphocytes and lamina propria plasma cells were lower than in coeliac disease, but lamina propria T cell populations were higher and crypt proliferation similar. Most strikingly, IgG deposition was seen on the basolateral epithelial surface in 23/25 autistic children, co-localising with complement C1q. This was not seen in the other conditions. These findings demonstrate a novel form of enteropathy in autistic children, in which increases in mucosal lymphocyte density and crypt cell proliferation occur with epithelial IgG deposition. The features are suggestive of an autoimmune lesion.

Review article: the concept of entero-colonic encephalopathy, autism and opioid receptor ligands.

There is growing awareness that primary gastrointestinal pathology may play an important role in the inception and clinical expression of some childhood developmental disorders, including autism. In addition to frequent gastrointestinal symptoms, children with autism often manifest complex biochemical and immunological abnormalities. The gut-brain axis is central to certain encephalopathies of extra-cranial origin, hepatic encephalopathy being the best characterized. Commonalities in the clinical characteristics of hepatic encephalopathy and a form of autism associated with developmental regression in an apparently previously normal child, accompanied by immune-mediated gastrointestinal pathology, have led to the proposal that there may be analogous mechanisms of toxic encephalopathy in patients with liver failure and some children with autism. Aberrations in opioid biochemistry are common to these two conditions, and there is evidence that opioid peptides may mediate certain aspects of the respective syndromes. The generation of plausible and testable hypotheses in this area may help to identify new treatment options in encephalopathies of extra-cranial origin. Therapeutic targets for this autistic phenotype may include: modification of diet and entero-colonic microbial milieu in order to reduce toxin substrates, improve nutritional status and modify mucosal immunity; anti-inflammatory/immunomodulatory therapy; and specific treatment of dysmotility, focusing, for example, on the pharmacology of local opioid activity in the gut.

Potential viral pathogenic mechanism for new variant inflammatory bowel disease.

AIMS: A new form of inflammatory bowel disease (ileocolonic lymphonodular hyperplasia) has been described in a cohort of children with developmental disorder. This study investigates the presence of persistent measles virus in the intestinal tissue of these patients (new variant inflammatory bowel disease) and a series of controls by molecular analysis. METHODS: Formalin fixed, paraffin wax embedded and fresh frozen biopsies from the terminal ileum were examined from affected children and histological normal controls. The measles virus Fusion (F) and Haemagglutinin (H) genes were detected by TaqMan reverse transcription polymerase chain reaction (RT-PCR) and the Nucleocapsid (N) gene by RT in situ PCR. Localisation of the mRNA signal was performed using a specific follicular dendritic cell antibody. RESULTS: Seventy five of 91 patients with a histologically confirmed diagnosis of ileal lymphonodular hyperplasia and enterocolitis were positive for measles virus in their intestinal tissue compared with five of 70 control patients. Measles virus was identified within the follicular dendritic cells and some lymphocytes in foci of reactive follicular hyperplasia. The copy number of measles virus ranged from one to 300,00 copies/ng total RNA. CONCLUSIONS: The data confirm an association between the presence of measles virus and gut pathology in children with developmental disorder.

Pertussis infection in childhood and subsequent type 1 diabetes mellitus.

AIMS: Pertussis has been implicated but not proven as a risk for Type 1 diabetes mellitus (DM). Previous studies have investigated paediatric, but not adult-onset Type 1 DM. We investigated association of pertussis exposures and Type 1 DM with follow-up into adulthood. METHODS: Longitudinal analysis of 16 820 members (100 with Type 1 DM) of two nationally representative British birth cohorts (the 1970 British Cohort Study (BCS70) and the National Child Development Study (NCDS)) followed from birth to ages 30 years (BCS70) and 42 years (NCDS). Cox regression analysis with age of onset for Type 1 DM as the dependent variable investigated relationships with pertussis infection and immunization, modelled as time-dependent co-variates. Simultaneous adjustment was made for Wild measles, mumps and chickenpox infections; tetanus and smallpox immunizations; sex, parental social class and cohort. The potential confounding factors were modelled as fixed co-variates. RESULTS: Cox regression analysis produced adjusted odds ratios (ORs) (with 95% confidence intervals (CIs)) of 2.21 (1.35-3.59) and 0.73 (0.49-1.05) for Type 1 DM (with onset at any age) associated with pertussis infections and immunization (trend over number of vaccinations), respectively. Adjusted ORs from Cox regression for Type 1 DM with onset after age 10 years are 2.59 (1.56-4.30) for pertussis infection and 0.63 (0.42-0.94) for pertussis immunization. None of the other infections or immunizations are notably associated with Type 1 DM. CONCLUSIONS: Some pertussis infections may be a risk for Type 1 DM and immunization may confer protection. Further research should consider delayed Type 1 DM following pertussis exposures.