Collagen adhesin protein and necrotic enteritis B-like toxin as biomarkers for early diagnosis of necrotic enteritis in commercial broiler chickens

Mouse monoclonal antibodies (mAbs) reactive with Clostridium perfringens collagen adhesin protein (CNA) and necrotic enteritis B-like toxin (NetB) were developed. The best capture/detection mAb pairs for CNA and NetB were selected based on their affinity and specificity to develop sandwich enzyme-linked immunosorbent assays (ELISAs) to detect CNA and NetB proteins, respectively, in jejunal digesta samples from commercial broiler farms in the United States. Prior to the analysis of samples from commercial broiler flocks, the specificity and sensitivity of the CNA and NetB ELISAs were validated using sera, jejunal digesta, and fecal samples from chickens coinfected with Eimeria maxima and CNA+/NetB+C. perfringens in an animal model of necrotic enteritis (NE). Subsequently, a total of 251 field samples were collected from 74 commercial poultry farms. Among these, 18 samples were from 6 broiler farms that used certified organics (CO), and 155 samples were from 42 farms with nonantibiotics (NA). In jejunal digesta samples, CNA levels ranged from 0.02 to 0.59 ng/mL and NetB levels ranged from 0.09 to 1.91 ng/mL. CNA and NetB levels showed a positive correlation with each other (Pearson correlation coefficient r = 0.772, P < 0.001). CNA and NetB levels in jejunal digesta were significantly decreased in CO farms compared with those from NA farms (P < 0.001). In conclusion, these new C. perfringens antigen-specific sandwich ELISAs offer a sensitive and specific means to detect C. perfringens CNA and NetB proteins as biomarkers of early NE occurrence in field samples from commercial broiler chickens.

Characterizing ruminal acidosis risk: A multiherd, multicountry study

A multicenter observational study was conducted on early lactation Holstein cows (n = 261) from 32 herds from 3 regions (Australia, AU; California, CA; and Canada, CAN) to characterize their risk of acidosis into 3 groups (high, medium, or low) using a discriminant analysis model previously developed. Diets ranged from pasture supplemented with concentrates to total mixed ration (nonfiber carbohydrates = 17 to 47 and neutral detergent fiber = 27 to 58% of dry matter). Rumen fluid samples were collected <3 h after feeding and analyzed for pH, and ammonia, d- and l-lactate, and volatile fatty acid (VFA) concentrations. Eigenvectors were produced using cluster and discriminant analysis from a combination of rumen pH, and ammonia, d-lactate, and individual VFA concentrations and were used to calculate the probability of the risk of ruminal acidosis based on proximity to the centroid of 3 clusters. Bacterial 16S ribosomal DNA sequence data were analyzed to characterize bacteria. Individual cow milk volume, fat, protein, and somatic cell count values were obtained from the closest herd test to the rumen sampling date (median = 1 d before rumen sampling). Mixed model analyses were performed on the markers of rumen fermentation, production characteristics, and the probability of acidosis. A total of 26.1% of the cows were classified as high risk for acidosis, 26.8% as medium risk, and 47.1% as low risk. Acidosis risk differed among regions with AU (37.2%) and CA (39.2%) having similar prevalence of high-risk cows and CAN only 5.2%. The high-risk group had rumen phyla, fermentation, and production characteristics consistent with a model of acidosis that reflected a rapid rate of carbohydrate fermentation. Namely, acetate to propionate ratio (1.98 ± 0.11), concentrations of valerate (2.93 ± 0.14 mM), milk fat to protein ratio (1.11 ± 0.047), and a positive association with abundance of phylum Firmicutes. The medium-risk group contains cows that may be inappetant or that had not eaten recently or were in recovery from acidosis. The low-risk group may represent cattle that are well fed with a stable rumen and a slower rumen fermentation of carbohydrates. The high risk for acidosis group had lower diversity of bacteria than the other groups, whereas CAN had a greater diversity than AU and CA. Rumen fermentation profile, abundance of ruminal bacterial phyla, and production characteristics of early lactation dairy cattle from 3 regions were successfully categorized in 3 different acidosis risk states, with characteristics differing between acidosis risk groups. The prevalence of acidosis risk also differed between regions.

Associations among the genome, rumen metabolome, ruminal bacteria, and milk production in early-lactation Holsteins

A multicenter observational study to evaluate genome-wide association was conducted in early-lactation Holstein cows (n = 293) from 36 herds in Canada, the USA, and Australia. Phenotypic observations included rumen metabolome, acidosis risk, ruminal bacterial taxa, and milk composition and yield measures. Diets ranged from pasture supplemented with concentrates to total mixed rations (nonfiber carbohydrates = 17 to 47, and neutral detergent fiber = 27 to 58% of dry matter). Rumen samples were collected <3 h after feeding and analyzed for pH, ammonia, d- and l-lactate, volatile fatty acid (VFA) concentrations, and abundance of bacterial phyla and families. Eigenvectors were produced using cluster and discriminant analyses from a combination of pH and ammonia, d-lactate, and VFA concentrations, and were used to estimate the probability of the risk of ruminal acidosis based on proximity to the centroid of 3 clusters, termed high (24.0% of cows), medium (24.2%), and low risk (51.8%) for acidosis. DNA of sufficient quality was successfully extracted from whole blood (218 cows) or hair (65 cows) collected simultaneously with the rumen samples and sequenced using the Geneseek Genomic Profiler Bovine 150K Illumina SNPchip. Genome-wide association used an additive model and linear regression with principal component analysis (PCA) population stratification and a Bonferroni correction for multiple comparisons. Population structure was visualized using PCA plots. Single genomic markers were associated with milk protein percent and the center logged ratio abundance of the phyla Chloroflexi, SR1, and Spirochaetes, and tended to be associated with milk fat yield, rumen acetate, butyrate, and isovalerate concentrations and with the probability of being in the low-risk acidosis group. More than one genomic marker was associated or tended to be associated with rumen isobutyrate and caproate concentrations, and the center log ratio of the phyla Bacteroidetes and Firmicutes and center log ratio of the families Prevotellaceae, BS11, S24-7, Acidaminococcaceae, Carnobacteriaceae, Lactobacillaceae, Leuconostocaceae, and Streptococcaceae. The provisional NTN4 gene, involved in several functions, had pleiotropy with 10 bacterial families, the phyla Bacteroidetes and Firmicutes, and butyrate. The ATP2CA1 gene, involved in the ATPase secretory pathway for Ca²⁺ transport, overlapped for the families Prevotellaceae, S24-7, and Streptococcaceae, the phylum Bacteroidetes, and isobutyrate. No genomic markers were associated with milk yield, fat percentage, protein yield, total solids, energy-corrected milk, somatic cell count, rumen pH, ammonia, propionate, valerate, total VFA, and d-, l-, or total lactate concentrations, or probability of being in the high- or medium-risk acidosis groups. Genome-wide associations with the rumen metabolome, microbial taxa, and milk composition were present across a wide geographical and management range of herds, suggesting the existence of markers for the rumen environment but not for acidosis susceptibility. The variation in pathogenesis of ruminal acidosis in the small population of cattle in the high risk for acidosis group and the dynamic nature of the rumen as cows cycle through a bout of acidosis may have precluded the identification of markers for acidosis susceptibility. Despite a limited sample size, this study provides evidence of interactions between the mammalian genome, the rumen metabolome, ruminal bacteria, and milk protein percentage.

The effects of dietary Bacillus subtilis supplementation, as an alternative to antibiotics, on growth performance, intestinal immunity, and epithelial barrier integrity in broiler chickens infected with Eimeria maxima

The objective of this study was to investigate the effects of dietary Bacillus subtilis supplementation on growth performance, jejunal lesion scores, oocyst shedding, and cytokine and tight junction protein expression in broiler chickens infected with Eimeria maxima. A total of 196 male day-old Ross 708 broilers were given a nonexperimental diet until 14 D of age. Then, all chickens were randomly assigned to one of seven dietary treatments: 2 basal diets (CON and NC); CON + virginiamycin (AB1); CON + bacitracin methylene disalicylate (BMD; AB2); CON + B. subtilis 1781 (PB1); CON + B. subtilis 747 (PB2); or CON + B. subtilis 1781 + 747 (PB3). At day 21, all chickens except those in the CON group were orally inoculated with E. maxima oocysts. At 7 D after E. maxima infection, the body weight gains of chickens fed PB2 and PB3 increased (P = 0.032) as much as those in chickens fed AB2. The body weight gain and feed efficiency of chickens fed PB2 were significantly increased (P < 0.001), and PB2 chickens showed (P = 0.005) the lowest lesion scores after E. maxima infection. Chickens fed PB2 showed (P < 0.05) lower mRNA expression of IL-1β in infected chicken groups. Chickens in the AB1, AB2, PB1, PB2, and PB3 groups showed (P < 0.05) greater mRNA expression of junctional adhesion molecule 2 in jejunal tissue, whereas occludin expression increased (P < 0.05) in the jejunal tissue of chickens fed AB2 or PB2. Dietary B. subtilis supplementation significantly improved the growth performance of young chickens to a level comparable with that induced by virginiamycin or BMD without E. maxima infection. After infection with E. maxima, dietary virginiamycin and BMD significantly enhanced the epithelial barrier integrity, and the dietary B. subtilis 747 showed significantly enhanced growth performance, intestinal immunity, and epithelial barrier integrity. Together our results indicated that certain strains of B. subtilis provide beneficial effects on the growth of young broiler chickens and have the potential to replace antibiotic growth promoters.

Bacteria and fungi in day-old turkeys vary among companies, collection periods, and breeder flocks

Microbial colonization of the intestinal tract of commercial poultry is highly variable, likely due to the fact that poults and chicks are hatched and raised without exposure to adult birds and their microbiota. In industrial poultry production, it is hypothesized that most of the microbiota is obtained through horizontal transmission from the environment and very little by maternal transmission. The initial gut microbiota will therefore differ between flocks and companies based on environmental conditions at the hatchery. Day-old poults were collected from the hatchery of 2 companies at 3 different time points to monitor the initial colonizing microbiota by sequencing amplicons of marker genes for bacteria, lactic acid bacteria (LAB), fungi, and archaea. Bacterial colonizers were distinct by company (pseudo-F 38.7, P ≤ 0.05) with the predominant bacteria at Company A being clostridia, specifically Clostridium celatum group, C. paraputrificum, and C. tertium. Predominant bacteria at Company B were Enterobacteriaceae, belonging to 2 different groups, one that included Escherichia; Shigella and Salmonella and the other Klebsiella; Enterobacter; and others. The predominant LAB at both companies were Enterococcus faecalis and E. gallinarum, confirmed by sequencing the 16S ribosomal RNA (rRNA) gene of colonies picked from lactobacilli agar plate counts. The predominant fungi were Aspergillus niger and Saccharomyces cerevisiae, with Candida sake or Alterneria sp. in some samples of Company A. Archaeal sequences were detected only in a single poult from Company B. The initial gastrointestinal colonizers of poults vary across company and time, signifying a strong environmental effect on microbiota acquisition. There was an indication of maternal effects in certain breeder flocks from Company B. Further work is necessary to determine how this variability affects microbiota succession and impacts growth and production of the birds.

Breast Cancer Diagnosis under the Age of Forty Years

The authors report on a multicentric consecutive series of 382 cases of primary breast cancer detected before the age of 40 years. Physical examination (PE) was always performed, whereas other diagnostic tests were performed in selected cases, namely mammography (M) in 334, fine needle aspiration cytology (CYT) in 188 and thermography (TH) in 123 cases. Single tests showed a high rate of false-negative/benign cases (PE, 0.23; M, 0.26; CYT, 0.37 and TH, 0.50), especially when the T1 subgroup was considered (PE, 0.34; M, 0.38; CYT, 0.42 and TH, 0.78). The poor results recorded for TH make its current diagnostic use highly questionable. The policy of extensive biopsy of all « dubious » benign lesions on PE allowed for the detection of 41 of 382 cancers and reduced the PE false-negative/benign rate to 0.12 for the total or 0.15 for T1 cancers, although about 80 unnecessary biopsies for each cancer detected were performed in this way. The association of PE to one or more tests resulted in even lower false-negative rates (0.06 for the total, 0.10 for T1 cancers). The authors criticize the aggressive policy of extensive biopsy recommendation based only on a dubious report on PE alone and stress the opportunity of the routine association of M and CYT to PE, since this combination seems to achieve a higher breast cancer detection rate even in this age group.

SorCS2 is required for BDNF-dependent plasticity in the hippocampus

SorCS2 is a member of the Vps10p-domain receptor gene family receptors with critical roles in the control of neuronal viability and function. Several genetic studies have suggested SORCS2 to confer risk of bipolar disorder, schizophrenia and attention deficit-hyperactivity disorder. Here we report that hippocampal N-methyl-d-aspartate receptor-dependent synaptic plasticity is eliminated in SorCS2-deficient mice. This defect was traced to the ability of SorCS2 to form complexes with the neurotrophin receptor p75NTR, required for pro-brain-derived neurotrophic factor (BDNF) to induce long-term depression, and with the BDNF receptor tyrosine kinase TrkB to elicit long-term potentiation. Although the interaction with p75NTR was static, SorCS2 bound to TrkB in an activity-dependent manner to facilitate its translocation to postsynaptic densities for synaptic tagging and maintenance of synaptic potentiation. Neurons lacking SorCS2 failed to respond to BDNF by TrkB autophosphorylation, and activation of downstream signaling cascades, impacting neurite outgrowth and spine formation. Accordingly, Sorcs2-/- mice displayed impaired formation of long-term memory, increased risk taking and stimulus seeking behavior, enhanced susceptibility to stress and impaired prepulse inhibition. Our results identify SorCS2 as an indispensable coreceptor for p75NTR and TrkB in hippocampal neurons and suggest SORCS2 as the link between proBDNF/BDNF signaling and mental disorders.

The use of clinical audit during a successful medical engagement in Afghanistan

OBJECTIVES

To describe a successful medical engagement during counter-insurgency operations in Afghanistan, and to demonstrate that a full audit cycle can be used in this environment to support improvements to local healthcare delivery.

METHODS

In the district of Nad-e-Ali, Helmand Province, Afghanistan, the management of children under five years of age (under-5s) who presented with diarrhoea to a Ministry of Public Health (MoPH) Basic Health Centre was audited. Staff then attended a training course on the Integrated Management of Childhood Illnesses (IMCI) in Kandahar. After further medical engagement to reinforce this training, the audit was repeated.

RESULTS

A lack of knowledge of the Afghan government's MoPH guidelines during the initial audit resulted in 90% of under-5s with acute diarrhoea being given unnecessary antibiotics and none receiving zinc as recommended. Following the training course and on-going engagement, there was a 67% reduction in the number of under-5s prescribed antibiotics and a 74% increase in the number who received zinc.

CONCLUSIONS

Opportunities for successful medical engagement during operations are limited but this example demonstrates that in conjunction with host nation facilities, sustainable improvements in healthcare are possible. Secondly, it shows that use of the audit cycle can provide objective evidence that may help encourage local staff to improve their standards of patient care.

Red blood cell transfusion volume and mortality among patients receiving extracorporeal membrane oxygenation

Background:

Red blood cell (RBC) transfusion is used in the critically ill with low hemoglobin concentrations to optimize oxygen utilization and delivery imbalance. Data suggest that RBC transfusion is also independently associated with significant morbidity. We seek to characterize RBC transfusion volumes among patients receiving extracorporeal membrane oxygenation (ECMO) support and test the hypothesis that red blood cell transfusion volume is an independent risk factor for mortality.

Methods:

Records of all patients receiving ECMO support from 2001 through 2010 at a university-affiliated children’s hospital were retrospectively reviewed.

Results:

Among 484 ECMO runs reviewed, indications for ECMO were classified as cardiac (40%), non-cardiac (42%) or institution of ECMO during cardiopulmonary resuscitation (CPR) (18%). Median duration of ECMO support was 4.6 days, with overall survival to hospital discharge significantly higher among non-cardiac patients (60%) relative to patients supported for cardiac (37%) or external CPR (ECPR) indications (34%, p<0.001). Median RBC transfusion volumes with respect to ECMO indication were significantly greater among cardiac (105 mL/kg/day ECMO) and ECPR patients (66 mL/kg/day ECMO) relative to patients supported for non-cardiac indications (20 mL/kg/day ECMO, p<0.001). Among patients supported with ECMO for non-cardiac indications alone (n=203), independent of covariates, including weight, venoarterial mode of ECMO support, presence of congenital diaphragmatic hernia and complications, including hemorrhage, neurologic injury, and renal insufficiency, each RBC transfusion volume of 10 mL/kg/day ECMO was associated with a 24% increase in the odds of in-hospital mortality (OR 1.024, 95% CI 1.004-1.046, p=0.018).

Conclusions:

Greater red blood cell transfusion volumes among patients supported with ECMO for non-cardiac indications are independently associated with an increase in odds of mortality. A prospective investigation of restrictive RBC transfusion practices while receiving ECMO may be warranted in this population.

DIET AND TISSUE GROWTH : I. THE REGENERATION OF LIVER TISSUE ON VARIOUS ADEQUATE DIETS

1. The toxicity of chloroform varies according to the diets used in these experiments in the following order of decreasing susceptibility of the animals: high fat > standard > high carbohydrate > high protein diets. 2. On the high fat and high carbohydrate diets there may be a more or less marked proliferation of the endothelium and the connective tissue stroma in the necrotic area producing in some instances scars resembling the picture of an early cirrhosis. 3. On the diets studied, standard, high carbohydrate, high protein, and high fat, the most active and rapid repair is observed on the standard balanced diet. On the high fat diet the reparative process is definitely delayed in comparison with the others. There are only slight differences between the high carbohydrate and high protein diets which suggest but do not conclusively show a more rapid repair with the latter diet.

DIET AND TISSUE GROWTH : IV. THE RATE OF COMPENSATORY RENAL ENLARGEMENT AFTER UNILATERAL NEPHRECTOMY IN THE WHITE RAT

The rate of compensatory enlargement of the remaining kidney after unilateral nephrectomy has been studied in adult rats fed diets containing various concentrations of protein. A curve of enlargement on "standard" food (18 per cent casein) shows a rapid initial increase with subsequent slower rise to the 120th day. There is no significant difference between the value at 120 days (44 per cent) and that at 150 days (48 per cent). A similar series with diets containing increasing concentrations of protein but with a constant time interval (21 days) after nephrectomy shows an increase in the degree of enlargement directly proportional to the protein content of the food. The values vary from 24 per cent with the 18 per cent casein ration to 77 per cent with the 90 per cent casein diet. A third series shows the enlargement on "high protein" food (85 per cent casein). The values vary from 49 per cent at 3 days to 121 per cent at 150 days. There is no significant difference between the value at 120 days (123 per cent) and that at 150 days (121 per cent). Determinations of total solids on the experimental kidneys show that the recorded enlargement involves mainly an actual tissue increase.

DIET AND TISSUE GROWTH : V. THE EFFECT OF DIETARY PROTEIN ON THE REMAINING KIDNEY OF ADULT WHITE RATS FOLLOWING A UNILATERAL NEPHRECTOMY

The effects of the ingestion of diets containing different concentrations of protein on the remaining kidney in adult white rats after a unilateral nephrectomy has been studied. In the animals on the high protein diet (85 per cent casein), actual glomerular and tubular lesions were observed in the kidneys of animals maintained for 90, 120 and 150 days after nephrectomy. In the animals on the standard ration, 18 per cent casein, no significant renal lesions were observed within the experimental period. Spontaneous focal lesions in the kidneys of rats maintained on Sherman's diets "A" and "B" were inconspicuous at the age of 350 days but became progressively more frequent and were commonly observed after 500 days. The animals on the high protein and standard rations were all under 350 days old at the completion of the experiment. It is suggested that the age factor is of importance in that young animals may have greater powers of adaptation in withstanding the injurious effect of high protein rations. The animals on the high protein ration excreted definitely larger quantities of protein in the urine, and showed a higher incidence of casts in periods roughly corresponding to those in which anatomic lesions were observed than did the rats on the standard diet.

DIET AND TISSUE GROWTH : II. THE REGENERATION OF LIVER TISSUE DURING NUTRITION ON INADEQUATE DIETS AND FASTING

The relative toxicity of chloroform given subcutaneously to rats fed on two diets deficient in respect to their nitrogenous components, the sole sources of protein in which were, respectively, gliadin and gelatin and to rats without food, is as follows: gelatin diet > fasting > gliadin diet. The rate of regeneration of liver cells after chloroform poisoning in rats fed a diet in which gliadin is the only protein is about as rapid as that in animals fed a diet containing casein as the source of nitrogen. The rate of regeneration on a food containing its nitrogen as gelatin and also during fasting is definitely slower than that in animals fed the gliadin food. The results of these experiments indicate that the requirement for the essential amino acids for growth of individual organs of the body is less than that for correlated growth of the whole body.

Improved methods and standards for telomerase detection: quantitative histopathology using antibody staining

Evaluation of telomerase as an early detection biomarker for cancer has been hindered by a lack of reliable methods and standards for in situ histochemical measurement. Improved histochemical methods for measuring telomerase could expedite the acceptance of telomerase as a biomarker for use in diagnostic and clinical applications. The lack of a crystal structure for telomerase coupled with high variability in the antibodies available for immunohistochemical analysis has led to confusion in the literature regarding the binding specificity of these antibodies. We have developed an automated fluorescence microscopy protocol to assess the specificity of three fluorescently labeled telomerase antibodies and to quantify telomerase in cultured human tumor cells and in human fibroblast cells as a control. Significant differences in staining intensity and distribution were observed. Fluorescence measurements in these cell lines were compared to telomerase measured by the telomerase repeat amplification protocol, reverse transcription-polymerase chain reaction, and flow cytometry. This combination of measurements ensured a more complete quantitation of telomerase levels in each of the cell lines and could also be used as a model for validation of other biomarkers for clinical use.

Meta-analysis of benzene exposure and non-Hodgkin lymphoma: biases could mask an important association

OBJECTIVES

Benzene is a widely recognised cause of leukaemia but its association with non-Hodgkin's lymphoma (NHL) is less well established. The goal of this project is to review the current published literature on this association.

METHODS

We performed a meta-analysis of cohort and case-control studies of benzene exposure and NHL and a meta-analysis of NHL and refinery work, a potential source of benzene exposure.

RESULTS

In 22 studies of benzene exposure, the summary relative risk for NHL was 1.22 (95% CI 1.02 to 1.47; one-sided p value = 0.01). When studies that likely included unexposed subjects in the "exposed" group were excluded, the summary relative risk increased to 1.49 (95% CI 1.12 to 1.97, n = 13), and when studies based solely on self-reported work history were excluded, the relative risk rose to 2.12 (95% CI 1.11 to 4.02, n = 6). In refinery workers, the summary relative risk for NHL in all 21 studies was 1.21 (95% CI 1.00 to 1.46; p = 0.02). When adjusted for the healthy worker effect, this relative risk estimate increased to 1.42 (95% CI 1.19 to 1.69).

CONCLUSIONS

The finding of elevated relative risks in studies of both benzene exposure and refinery work provides further evidence that benzene exposure causes NHL. In addition, the finding of increased relative risks after removing studies that included unexposed or lesser exposed workers in "exposed" cohorts, and increased relative risk estimates after adjusting for the healthy worker effect, suggest that effects of benzene on NHL might be missed in occupational studies if these biases are not accounted for.

Development of Nested Polymerase Chain Reaction Detection of Mycosphaerella spp. and Its Application to the Study of Leaf Disease in Eucalyptus Plantations

ABSTRACT Mycosphaerella leaf disease (MLD) is a serious disease of two of the major eucalypt species grown in temperate regions worldwide, Eucalyptus globulus and E. nitens. More than 30 species of Mycosphaerella have been reported on eucalypts worldwide. Accurate, rapid, and early discrimination of Mycosphaerella spp. causing crown damage to E. globulus and E. nitens will assist the development of sustainable management strategies. This study describes the development, and incorporation in a nested polymerase chain reaction (PCR) approach, of specific primers for the detection and identification of Mycosphaerella spp. commonly reported from leaf lesions of E. globulus and E. nitens in Australia. Primer design was assisted by sequence alignment and phylogenetic analysis of 165 nonredundant sequences from the nuclear ribosomal DNA internal transcribed spacer regions of Mycosphaerella and related species. Phylo-genetic analysis revealed very high sequence similarity for two taxon groups, Mycosphaerella grandis and M. parva, and M. vespa, M. ambi phylla, and M. molleriana, and primers were designed to differentiate each of the two groups. Three other species, M. cryptica, M. nubilosa, and M. tasmaniensis, were distinct and distinguished by species-specific primers. In double-blind trials, the detection test accurately and rapidly identified Mycosphaerella spp. in cultures and discriminated against other pathogens that co-occur in or on Eucalyptus leaves, thereby verifying its reliability. The detection test has an internal amplification control in the first-round PCR with fungal-specific primers to raise confidence in test results, particularly to highlight negative results due to PCR inhibition. When applied to DNA extracted from leaf or stem samples either as multiple or single lesions, it detected and identified up to five Mycosphaerella spp. or taxon groups in both positively identified and in young (putative) MLD lesions. The samples were 20 mm(2) or larger in surface area and were collected while undertaking disease rating assessments in an experimental investigation of Eucalyptus plantations and regrowth forest. Using nested PCR detection, Mycosphaerella spp. were positively identified in 2 days, 1 to 5 months earlier than by classical methods, demonstrating the potential application of this detection test to the early discrimination of MLD components in ecological, epidemiological, and genetic investigations.

Pregnancy outcomes, infant mortality, and arsenic in drinking water in West Bengal, India

Between 2001 and 2003, the authors studied pregnancy outcomes and infant mortality among 202 married women in West Bengal, India. Reproductive histories were ascertained using structured interviews. Arsenic exposure during each pregnancy, including all water sources used, was assessed; this involved measurements from 409 wells. Odds ratios for spontaneous abortion, stillbirth, neonatal mortality, and infant mortality were estimated with logistic regression based on the method of generalized estimating equations. Exposure to high concentrations of arsenic (> or =200 microg/liter) during pregnancy was associated with a sixfold increased risk of stillbirth after adjustment for potential confounders (odds ratio (OR) = 6.07, 95% confidence interval (CI): 1.54, 24.0; p = 0.01). Arsenic-related skin lesions were found in 12 women who had a substantially increased risk of stillbirth (OR = 13.1, 95% CI: 3.17, 54.0; p = 0.002). The odds ratio for neonatal death was 2.81 (95% CI: 0.73, 10.8). No association was found between arsenic exposure and spontaneous abortion (OR = 1.01, 95% CI: 0.38, 2.70) or overall infant mortality (OR = 1.33, 95% CI: 0.43, 4.04). This study adds to the limited evidence that exposure to high concentrations of arsenic during pregnancy increases the risk of stillbirth. However, there was no indication of the increased rates of spontaneous abortion and overall infant mortality that have been reported in some studies.

Precision and accuracy of pest and pathogen damage assessment in young eucalypt plantations

Fungal pathogens, browsing mammals, birds, insects, nutrient deficiencies, drought, frost and waterlogging are all damaging agents to plantation species. The subsequent loss in leaf tissue or reduced photosynthetic potential can reduce growth and potentially lead to tree death. The Crown Damage Index (CDI) was developed in Australia to quantify damage in young eucalypt plantations. The accuracy and precision of assessing damage at a tree level were determined to ensure the reliability, objectivity and repeatability of the CDI method. Nine assessors, with varying levels of experience, estimated damage on three plots of fifty trees each, to obtain an understanding of the subjectivity of assessing damage caused by insects (e.g. Chrysophtharta spp.) and fungal pathogens (e.g. Mycosphaerella spp.) on Eucalyptus globulus. Damage levels were measured by destructive sampling to enable direct comparisons between estimates and damage levels to be made. The most experienced assessors provided the most repeatable estimates and were generally the most accurate. The incidence of foliar necrosis was the least subjective measure while defoliation was the most subjective and the least accurate of the indices measured. All assessors, regardless of experience, were able to predict the Crown Damage Index (a combined index of all damage classes) to within 12% of measured damage levels.

Cross-calibration of GE/Lunar pencil and fan-beam dual energy densitometers--bone mineral density and body composition studies

OBJECTIVE

In vitro and in vivo comparisons of bone mineral density (BMD) and body composition between GE/Lunar pencil (DPXL) and fan-beam (PRODIGY) absorptiometers.

DESIGN

Comparison of BMD, bone mineral content (BMC) and area of lumbar spine (L2-L4), femoral neck and total body. Total body composition compartments tissue (TBTissue), fat (TBF), lean tissue (TBLean) and %TBF were also compared.

SETTING

Centre for Bone and Body Composition Research, University of Leeds. PHANTOMS/SUBJECTS: A range of spine phantoms, a variable composition phantom (VCP) and total body phantom. A total of 72 subjects were included for the in vivo study.

RESULTS

In vitro: A small significant underestimation of BMD by the Prodigy compared to the DPXL ranging from 0.7 to 2% (p<0.05-0.001) for the spine phantoms. The Prodigy underestimated the VCP %Fat. Although the Prodigy underestimated phantom TBBMD by 1.1+/-1.0%, TBBMC and area were reduced by 8.2+/-1.4 and 7.3+/-1.0%, respectively. The Prodigy overestimated TBTissue 1508 g (2.2%), TBLean 588 g (1.2%), TBF 919 g (4.8%) and %TBF (0.8%). In vivo: BMD cross-calibration was only required in the femoral neck, DPXL(BMD)=0.08+0.906*PRODIGY(BMD). The Prodigy had higher estimates for TBTissue 1360 g (2.3%), TBLean 840 g (2.0%), TBF 519 g (3.4%), TBBMC 32.8 g (1.3%) and %TBF (0.3%). Cross-calibration equations were required for TBTissue(DPXL)=-1158+0.997*TBTissue(PRODIGY) and TBBMC(DPXL)= 89.7+0.949*TBBMC(PRODIGY).

CONCLUSIONS

Small differences between the two absorptiometers for both BMD and body composition can be made compatible by use of cross-calibration equations and factors. The discrepancy in body composition compartments requires further research.

Gravitational influences upon the maintenance requirements of rabbits

The gravitational component of the feed requirement for the maintenance of body mass has been reported previously for chickens. Similar measurements are reported here for chronically accelerated Polish rabbits, which have mature body masses around 2 kg, approximately the same as for the single-comb white Leghorn chickens used in the earlier experiments. The gravitational influences upon the maintenance requirement and upon body composition were found to be essentially similar for rabbits and chickens, indicating a general phenomenon for small homoiotherms. The principal response in both groups is a greater feed maintenance requirement which increases linearly with the applied acceleration field. The nature of this response is similar to that which follows lesioning of the lateral hypothalamus in rats, though no causal connection between the two phenomena is necessarily implied by these present studies. In monkeys a qualitatively different response of increased body fat is observed.

Metabolic responses of monkeys to increased gravitational fields

A depletion of body fat has been reported by several investigators for various species of homoiotherms exposed to chronic acceleration. Generally the effect is proportional to field strength, and over the size range examined (0.25-5 kg) it becomes more severe in larger animals. There is some evidence that this may be the result of increased secretion of a pituitary hormone, the fat mobilizing substance (FMS). An exception to the defatting effect of chronic acceleration was observed in mature pig-tailed monkeys (Macaca nemestrina)--although they exhibited other changes generally found in homoiotherms exposed to hyperdynamic environments. It is considered that this unusual primate response to chronic acceleration may result from a different geometry of the central nervous system, and its effect upon gravity load distribution in the lower part of the brain.

Effects of chronic acceleration in animals

Chronic acceleration describes the exposure of animals to increased acceleration fields of sufficient intensity and duration to induce physiological adaptation. By comparing the degree of changes observed in several fields with the acceleration intensity, it is possible to derive an estimate of the biological effect of gravity. For technical reasons, such studies are limited to artificial fields produced by protracted centrifugation. Observations by various investigators indicate a fairly general response to chronic acceleration. Over the size range presented by these species (0.04-5 kg), there appears to be a direct relationship between body mass and the degree of the acceleration-induced effect (tolerable field intensity, growth repression, inhibition of fat (correction of far) deposition, etc.). However, different response patterns may obtain in homeotherms that differ significantly from this body size range.

Physiological changes associated with long-term increases in acceleration

The long-term retention of organisms in increased acceleration fields is an experimental approach towards understanding the biological consequences of earth gravity. Such treatment, called chronic acceleration, simulates a change in gravity and requires exposed organisms to adapt physiologically to the new environment. Information from chronic acceleration supplements that from space physiology in understanding gravitational physiology. Many of the responses in long-term exposure to increased acceleration are those which would be anticipated from the imposed symmetrical loading. For example, increased requirements for posture and locomotion induce appropriate changes in musculo-skeletal organs. Displacement of body fluids and increased hydrostatic pressures lead to greater blood volumes and increased tissue hydration. However, there are also specific acceleration effects which cannot be so directly interpreted. Among these are decreases of mature body size and of depot fat, which are proportional in degree to field strength. The role of chronic acceleration research in the development of gravitational biology and its relationship to earth-orbital experiments are considered. The applicability of chronic acceleration studies with human subjects towards planning of deep space exploration is also discussed.

The roles of body mass and gravity in determining the energy requirements of homoiotherms

Studies by Kleiber and by Brody in the 1930's established the 3/4 power of body weight as the unit for comparison of metabolic phenomena in homoiotherms. Later Kleiber conceived of the energy requirement as a composite function, with a thermoregulatory component, proportional to heat loss, and an antigravity component that is directly proportional to body weight. Maintenance feed requirements have been measured with groups of small animals chronically exposed to several acceleration fields. Analysis of the results leads to an arithmetic relationship between the maintenance requirement and acceleration field strength: Fg = Fo+k g Where: F is the maintenance feed requirement (Fg in field of g strength, and Fo where g=0); and, g is the ambient acceleration field strength. When the equations are compared for groups of different body size, Fo tends to vary between the 0.4 and 0.5 power of body mass--and k tends to be the same, irrespective of body mass (BM). These findings tend to confirm the Kleiber concept of a composite nature of homoiotherm maintenance requirements.

Influence of the ambient acceleration field upon acute acceleration tolerance in chickens

It has been demonstrated both in the Russian and in the American space programs that there is a progressive deconditioning of the circulatory system with exposure to weightlessness. Astronauts and cosmonauts returned to Earth have a significantly reduced orthostatic tolerance which will persist for a few days. We have measured the acceleration tolerance of domestic fowl, acutely exposed to a 6 g+z field, as the time over which a normal heart rate can be maintained. This period of circulatory accommodation ends abruptly with a marked bradycardia, which with continued treatment is terminal. For animals which have been previously chronically accelerated (e.g., physiologically adapted to a 2.5 g field) the acute acceleration tolerance is greatly increased. It appears that the influence of the ambient acceleration field in conditioning the responsiveness of the circulatory system is a general phenomenon.

Gravitational effects on body composition in birds

Gallinaceous birds, presenting a wide range of body size, were adapted physiologically to hyperdynamic environments, provided by chronic centrifugation. Chemical composition was measured directly on prepared carcasses, which were anatomically comparable, and more amenable to analysis than the intact body. Body mass and body fat decreased arithmetically with increasing field strength and also with increasing body mass. Water content of lean tissue increased in hyperdynamic environments, but irrespectively of body size.

Radiation protection issues of treating hyperthyroidism with 131 I in patients on haemodialysis

We report on the cases of two patients referred for 131I treatment of hyperthyroidism who were dependent on haemodialysis. Following 131I administration, all disposable lines and filters from dialysis were collected and measured for 131I radioactivity. The amount of 131I retained by the filters at the end of each successive dialysis session was found to decay with effective half-lives of 6.6+/-0.2 and 6.3+/-0.2 days. Dose rate measurements at 1m from the patients were recorded to find the effective half-life of the radioiodine clearance, which were found to be 6.9 and 7.1 days. From measured dose rates taken at 30 cm, the radiation hazard to ward staff involved in patient management was shown to be negligible.

Tissue densities in developing avian embryos

Changes in the weight:mass ratio provide the physical basis for the biological responses of terrestrial organisms to alteration in the ambient acceleration field. Where organisms such as aquatic animals occupy dense media, changes in the gravitational environment produce compensating changes in the weight:mass ratios of organism and medium, such that little net load is imposed upon the organism. This relationship also applies to organs of terrestrial animals. Changes in the ambient acceleration field produce compensatory changes in surrounding tissues so that the organ may not develop a significant net load. This relationship has been investigated in the case of the vertebrate brain. However, density gradients within the organ/organism will produce a local gravitational loading, which may lead to biological responses. In fact, a significant density gradient would be an essential character for a gravity receptor. Prenatal development, both in mammals and birds, occurs characteristically in a buoyant condition. In both cases a volume of amniotic fluid develops and surrounds the embryo while it is still of microscopic size. This situation prevails until the latest stages of prenatal development. In mammals the amniotic fluid is lost immediately prior to parturition through rupture of the sac. In chick embryos the amniotic fluid is ingested, beginning on the 13th day with the process being completed by the 18th day of development, just prior to the pre-hatch reorientation of the embryo. Consequently, a net load upon the embryo/fetus is not considered to be a major factor in gravitational experiments of prenatal development. Prenatal development includes marked changes in chemical composition as well as changes in size. This is readily apparent from extensive and detailed examination of the chemical growth for the chick embryo. These chemical materials vary in density, as well as in distribution among the tissues of the developing organism. Consequently, the existence of density gradients, and changes in them may be anticipated during prenatal development.

Muscularity as a function of species, sex and age in small mammals

The size of individual skeletal muscles in mammals is well known to change with the degree of mechanical loading imposed on the muscle. Less clear has been the effect of changes in loading of the whole organism on size of the total skeletal musculature. Pitts and coworkers have provided valuable insights by dissection and weighing of the skeletal musculature of animals subjected to various chronic centrifugation, exercise and dietary regimens, and their recent findings are reported at this meeting. However, questions remain. Independently, our laboratory several years ago embarked on a systematic definition of body composition and energy metabolism changes as a function of sex and age in 5 species of small laboratory mammals, the mouse, hamster, rat, guinea pig and rabbit. Six animals of each sex were examined in 8 age cohorts ranging from 1 to 24 months for each of the 5 species.

A comparison of physical and sexual abuse: histories of sexual and non-sexual offenders with intellectual disability

OBJECTIVES

To review patterns of physical and sexual abuse in cohorts of sexual offenders and nonsexual offenders with intellectual disability.

METHOD

Forty-six sexual offenders were compared with 48 male nonsexual offenders in relation to their experiences of sexual and physical abuse in childhood. Comprehensive assessments were taken over a period of at least one year, and were conducted independently by a range of professionals.

RESULTS

Thirty-eight percent of the sexual offenders and 12.7% of the nonsexual offenders had experienced sexual abuse, while 13% of the sexual offenders and 33% of the nonsexual offenders had experienced physical abuse.

CONCLUSIONS

Sexual abuse seems a significant variable in the history of sexual offenders, while physical abuse seems a significant variable in the history of nonsexual offenders. The results support the view that the "cycle of abuse" is neither inevitable nor an adequate explanation of future offending.

A novel sodium-hydrogen exchanger isoform-1 inhibitor, zoniporide, reduces ischemic myocardial injury in vitro and in vivo

The cardioprotective efficacy of zoniporide (CP-597,396), a novel, potent, and selective inhibitor of the sodium-hydrogen exchanger isoform 1 (NHE-1), was evaluated both in vitro and in vivo using rabbit models of myocardial ischemia-reperfusion injury. In these models, myocardial injury was elicited with 30 min of regional ischemia and 120 min of reperfusion. Zoniporide elicited a concentration-dependent reduction in infarct size (EC(50) of 0.25 nM) in the isolated heart (Langendorff) and reduced infarct size by 83% (50 nM). This compound was 2.5- to 20-fold more potent than either eniporide or cariporide (EC(50) of 0.69 and 5.11 nM, respectively), and reduced infarct size to a greater extent than eniporide (58% reduction in infarct size). In open-chest, anesthetized rabbits, zoniporide also elicited a dose-dependent reduction in infarct size (ED(50) of 0.45 mg/kg/h) and inhibited NHE-1-mediated platelet swelling (maximum inhibition 93%). Furthermore, zoniporide did not cause any in vivo hemodynamic (mean arterial pressure, heart rate, rate pressure product) changes. Zoniporide represents a novel class of potent NHE-1 inhibitors with potential utility for providing clinical cardioprotection.

Arsenic in drinking water and the prevalence of respiratory effects in West Bengal, India

BACKGROUND

A large population in West Bengal, India has been exposed to naturally occurring inorganic arsenic through their drinking water. A cross-sectional survey involving 7683 participants of all ages was conducted in an arsenic-affected region between April 1995 and March 1996. The main focus of the study was skin keratoses and pigmentation alterations, two characteristic signs of ingested inorganic arsenic. Strong exposure-response gradients were found for these skin lesions. The study also collected limited information concerning respiratory system signs and symptoms, which we report here because increasing evidence suggests that arsenic ingestion also causes pulmonary effects.

METHODS

Participants were clinically examined and interviewed, and the arsenic content in their current primary drinking water source was measured. There were few smokers and analyses were confined to non-smokers (N = 6864 participants).

RESULTS

Among both males and females, the prevalence of cough, shortness of breath, and chest sounds (crepitations and/or rhonchi) in the lungs rose with increasing arsenic concentrations in drinking water. These respiratory effects were most pronounced in individuals with high arsenic water concentrations who also had skin lesions. Prevalence odds ratio (POR) estimates were markedly increased for participants with arsenic-induced skin lesions who also had high levels of arsenic in their current drinking water source (> or = 500 microg/l) compared with individuals who had normal skin and were exposed to low levels of arsenic (<50 microg/l). In participants with skin lesions, the age-adjusted POR estimates for cough were 7.8 for females (95% CI : 3.1-19.5) and 5.0 for males (95% CI : 2.6-9.9); for chest sounds POR for females was 9.6 (95% CI : 4.0-22.9) and for males 6.9 (95% CI : 3.1-15.0). The POR for shortness of breath in females was 23.2 (95% CI : 5.8-92.8) and in males 3.7 (95% CI : 1.3-10.6).

CONCLUSION

These results add to evidence that long-term ingestion of inorganic arsenic can cause respiratory effects.

Lung cancer and arsenic concentrations in drinking water in Chile

Cities in northern Chile had arsenic concentrations of 860 microg/liter in drinking water in the period 1958-1970. Concentrations have since been reduced to 40 microg/liter. We investigated the relation between lung cancer and arsenic in drinking water in northern Chile in a case-control study involving patients diagnosed with lung cancer between 1994 and 1996 and frequency-matched hospital controls. The study identified 152 lung cancer cases and 419 controls. Participants were interviewed regarding drinking water sources, cigarette smoking, and other variables. Logistic regression analysis revealed a clear trend in lung cancer odds ratios and 95% confidence intervals (CIs) with increasing concentration of arsenic in drinking water, as follows: 1, 1.6 (95% CI = 0.5-5.3), 3.9 (95% CI = 1.2-12.3), 5.2 (95% CI = 2.3-11.7), and 8.9 (95% CI = 4.0-19.6), for arsenic concentrations ranging from less than 10 microg/liter to a 65-year average concentration of 200-400 microg/liter. There was evidence of synergy between cigarette smoking and ingestion of arsenic in drinking water; the odds ratio for lung cancer was 32.0 (95% CI = 7.2-198.0) among smokers exposed to more than 200 microg/liter of arsenic in drinking water (lifetime average) compared with nonsmokers exposed to less than 50 microg/liter. This study provides strong evidence that ingestion of inorganic arsenic is associated with human lung cancer.

Aldose reductase inhibition alone or combined with an adenosine A(3) agonist reduces ischemic myocardial injury

This study investigated whether aldose reductase (AR) inhibition with zopolrestat, either alone or in combination with an adenosine A(3)-receptor agonist (CB-MECA), reduced myocardial ischemic injury in rabbit hearts subjected to 30 min of regional ischemia and 120 min of reperfusion. Zopolrestat reduced infarct size by up to 61%, both in vitro (2 nM to 1 microM; EC(50) = 24 nM) and in vivo (50 mg/kg). Zopolrestat reduced myocardial sorbitol concentration (index of AR activity) by >50% (control, 15.0 +/- 2.2 nmol/g; 200 nM zopolrestat, 6.7 +/- 1.3 nmol/g). A modestly cardioprotective concentration of CB-MECA (0.2 nM) allowed a 50-fold reduction in zopolrestat concentration while providing a similar reduction in infarct size (infarct area/area at risk: control, 62 +/- 2%; 1 microM zopolrestat, 24 +/- 5%; 20 nM zopolrestat plus 0.2 nM CB-MECA, 20 +/- 4%). In conclusion, AR inhibition is cardioprotective both in vitro and in vivo. Furthermore, combining zopolrestat with an A(3) agonist allows a reduction in the zopolrestat concentration while maintaining an equivalent degree of cardioprotection.

The effect of pelvic ileal reservoir volume and antiperistaltic reflux on emptying efficiency

PURPOSE

The emptying efficiency of four different designs of pelvic ileal reservoir was compared using two different techniques of measurement.

METHOD

Thirty-four patients were studied one year after restorative proctocolectomy. In each the ileal reservoir was filled with methyl cellulose paste labeled with 51chromium-chromate and technetium Tc 99m-diethylenetriamine pentaacetic acid. Percentage evacuation was calculated from 1) the difference in 51chromium activity between the recovered effluent and the total paste administered and 2) gamma camera measurements of technetium Tc 99m-diethylenetriamine pentaacetic acid activity within the ileal reservoir before and after evacuation.

RESULTS

Median evacuation using the 51chromium method was 84, 90, 70, and 75 percent for the W40, W30, J40, and J30 reservoirs respectively. The results were not significantly different from those obtained using the gamma camera: 83, 87, 67, and 71 percent (P = not significant). Patients with either type of W reservoir evacuate isotope-labeled paste more efficiently than patients with J40 reservoirs (P < 0.05 and P < 0.001, respectively) but not J30 reservoirs (P = not significant). However, if the actual volume of paste evacuated during a visit to the lavatory is measured, it is greatest for J40 reservoirs (median, 300 ml compared with 258 ml for W40, 289 ml for W30, and 268 ml for J30; P = not significant).

CONCLUSIONS

Gamma camera measurement of ileal reservoir emptying is as accurate as our previous standard technique and provides a qualitative record of pouch evacuation, which may reveal reasons for inefficient emptying. The gamma camera images reveal that the difference in emptying percentage between W and J pouches is because of reflux of paste into the afferent ileum occurring more frequently in J pouches than in W pouches. The effect of this phenomenon on emptying is more than compensated for by the increase in reservoir capacity created by the reflux.

Osteoporosis and osteopenia in adults and adolescents with cystic fibrosis: prevalence and associated factors

BACKGROUND

Patients with cystic fibrosis (CF) have many risk factors for reduced bone mineral density (BMD). The aim of this study was to determine the prevalence of osteoporosis and osteopenia in a large cross section of patients and to identify risk factors.

METHODS

All patients attending the regional centre were invited to participate in the study. Bone mineral density was measured at the lumbar spine, femoral neck, and for total body with a Lunar DPX-L densitometer. Multiple indices of disease severity were investigated, and liver and thyroid function, blood calcium, phosphate, 25-OH vitamin D, follicle stimulating and luteinising hormone, oestradiol, and testosterone levels were measured. Patients completed a four day prospective dietary diary. Exercise was assessed by a seven day activity recall questionnaire. Sexual development and treatment histories were obtained. The relationship between all these variables and BMD measurements was analysed.

RESULTS

Sixty six percent of 114 patients assessed had osteopenia or osteoporosis. The Shwachman-Kulczycki (SK) clinical score (higher score = less severe disease) correlated significantly with BMD at the lumbar spine and femoral neck, and with total body BMD (p<0.001). There was a predicted increase of 0.0032 g/cm(2) in lumbar spine BMD for every unit increase in the SK score. Oral steroid use was significantly associated with reduced BMD at the lumbar spine (p = 0.017) and femoral neck (p = 0.027).

CONCLUSIONS

Osteopenia and osteoporosis are common findings in a heterogeneous population of adults with CF. Patients at most risk are those with severe disease and those who have used corticosteroids.

Arsenic-induced skin lesions among Atacameño people in Northern Chile despite good nutrition and centuries of exposure

It has been suggested that the indigenous Atacameño people in Northern Chile might be protected from the health effects of arsenic in drinking water because of many centuries of exposure. Here we report on the first intensive investigation of arsenic-induced skin lesions in this population. We selected 11 families (44 participants) from the village of Chiu Chiu, which is supplied with water containing between 750 and 800 microg/L inorganic arsenic. For comparison, 8 families (31 participants) were also selected from a village where the water contains approximately 10 microg/L inorganic arsenic. After being transported to the nearest city for blind assessment, participants were examined by four physicians with experience in studying arsenic-induced lesions. Four of the six men from the exposed village, who had been drinking the contaminated water for more than 20 years, were diagnosed with skin lesions due to arsenic, but none of the women had definite lesions. A 13-year-old girl had definite skin pigmentation changes due to arsenic, and a 19-year-old boy had both pigmentation changes and keratoses on the palms of his hands and the soles of his feet. Family interviews identified a wide range of fruits and vegetables consumed daily by the affected participants, as well as the weekly intake of red meat and chicken. However, the prevalence of skin lesions among men and children in the small population studied was similar to that reported with corresponding arsenic drinking water concentrations in both Taiwan and West Bengal, India--populations in which extensive malnutrition has been thought to increase susceptibility.

Diet and bladder cancer: a meta-analysis of six dietary variables

In 1996, more than 300,000 new cases of bladder cancer were diagnosed worldwide. Besides tobacco smoking, occupation, and other factors, diet may play a role in causation of this illness. The authors performed a meta-analytical review of epidemiologic studies linking six dietary factors to bladder cancer. These factors include retinol, beta-carotene, fruits, vegetables, meat, and fat. Increased risks of bladder cancer were associated with diets low in fruit intake (relative risk (RR) = 1.40, 95% confidence interval (CI): 1.08, 1.83), and slightly increased risks were associated with diets low in vegetable intake (RR = 1.16, 95% CI: 1.01, 1.34). Elevated risks were identified for diets high in fat intake (RR = 1.37, 95% CI: 1.16, 1.62) but not for diets high in meat intake (RR = 1.08, 95% CI: 0.82, 1.42). No increased risks were found for diets low in retinol (RR = 1.01, 95% CI: 0.83, 1.23) or beta-carotene (RR = 1.10, 95% CI: 0.93, 1.30) intake. These results suggest that a diet high in fruits and vegetables and low in fat intake may help prevent bladder cancer, but the individual dietary constituents that reduce the risks remain unknown.