Transapical balloon dilation of cor triatriatum sinister in a cat.

A hybrid surgical approach was utilized to address cor triatriatum sinister in a 10-month-old castrated male domestic shorthair cat. Prior to surgery, open-mouth breathing occurred with exertion. The procedure was guided by transesophageal echocardiography and fluoroscopy. A minithoracotomy was performed, and the left atrial membrane was accessed via an introducer placed through the left ventricular apex. Sequential balloon dilations were performed, and the mean transmembrane gradient under anesthesia was reduced from 16 mmHg to 2.23 mmHg. Four months after surgery, the transmembrane mean gradient remained lower than prior to intervention. The cat tolerated surgery well and remains free of clinical signs nine months after surgery.

Opportunistic bacterial infections in breeding colonies of the NSG mouse strain.

Spontaneous morbidity primarily affecting female breeders in 3 independent breeding colonies of NSG (NOD.Cg-Prkdc(scid) I12rg(tm1Wjl) /SzJ) mice prompted an investigation to uncover the cause of disease. Necropsies were performed on 264 (157 female and 107 male) spontaneously sick, experimentally unmanipulated NSG mice. In sum, 42 mice (15.9%) had acute or chronic renal inflammatory lesions, of which 12 had concurrent histologic evidence of an ascending urinary tract infection. From 94 kidneys cultured for bacterial organisms, 23 (24.5%) grew Enterococcus sp and 19 (20.2%) grew Klebsiella oxytoca. Female mice were twice more likely than males to present with nephritis. These findings indicate that bacterial nephritis is a major contributor to morbidity in the NSG strain.

Seroprevalence, correlates, and characteristics of undetected coeliac disease in England.

OBJECTIVE: To examine the seroprevalence, correlates, and characteristics of undetected coeliac disease in a large adult population sample in Cambridge, UK. METHODS: The Cambridge General Practice Health Study invited individuals from 12 general practices, aged 45-76 years, to attend for a health survey that included a bone density measurement, between 1990 and 1995. A total of 7550 participants' serum samples were tested for antiendomysial antibody (EMA). Seroprevalence of undetected coeliac disease was based on EMA positivity. Differences between EMA positive and negative participants of various physiological correlates and reported characteristics were estimated by multivariate logistic and linear regression and adjusted for age, sex, social class, and smoking behaviour. RESULTS: The seroprevalence of undetected coeliac disease in this general population sample aged 45-76 was 1.2% (95% confidence interval (CI) 0.9-1.4). EMA positive participants (n=87) were on average slightly lighter by 2.2 kg (p=0.08), were more likely to have reported their general health as being "good or excellent" (odds ratio (OR) 1.76 (95% CI 0.90-3.46)), and were less likely to report being a current smoker (OR for current versus never 0.36 (95% CI 0.14-0.90)) than EMA negative participants. EMA positivity was associated with an 8% reduction in mean serum cholesterol (0.5 mmol/l; p<0.01) and reductions in mean haemoglobin (0.3 g/dl; p<0.01), total protein (1.0 g/l; p<0.05), and corrected serum calcium (0.02 mmol/l; p<0.05). There was an increased risk of osteoporosis in EMA positive participants (OR 3.1 (95% CI 1.3-7.2)) and of mild anaemia (OR 4.6 (95% CI 2.5-8.2)) compared with EMA negative participants. CONCLUSIONS: Undetected coeliac disease is likely to affect approximately 1% of the population of England aged 45-76 years, a value similar to several other countries. Those affected report "better health" but they do have an increased risk of osteoporosis and mild anaemia. In contrast, they have a favourable cardiovascular risk profile that may afford protection from ischaemic heart disease and stroke.

Impacts of experimentally applied mountain biking and hiking on vegetation and soil of a deciduous forest.

Many recent trail degradation problems have been attributed to mountain biking because of its alleged capacity to do more damage than other activities, particularly hiking. This study compared the effects of experimentally applied mountain biking and hiking on the understory vegetation and soil of a deciduous forest. Five different intensities of biking and hiking (i.e., 0, 25, 75, 200 and 500 passes) were applied to 4-m-long x 1-m-wide lanes in Boyne Valley Provincial Park, Ontario, Canada. Measurements of plant stem density, species richness, and soil exposure were made before treatment, two weeks after treatment, and again one year after treatment. Biking and hiking generally had similar effects on vegetation and soil. Two weeks after treatment, stem density and species richness were reduced by up to 100% of pretreatment values. In addition, the amount of soil exposed increased by up to 54%. One year later, these treatment effects were no longer detectable. These results indicate that at a similar intensity of activity, the short-term impacts of mountain biking and hiking may not differ greatly in the undisturbed area of a deciduous forest habitat. The immediate impacts of both activities can be severe but rapid recovery should be expected when the activities are not allowed to continue. Implications of these results for trail recreation are discussed.

Modelling the germination of Stellaria media using the concept of hydrothermal time.

The germination characteristics of Stellaria media (common chickweed) were investigated over a range of constant temperatures and degrees of moisture stress in order to assess the suitability of hydrothermal time as a basis for modelling germination under field conditions. Maximum percentage germination occurred over a much narrower temperature range around the optimum temperature than previously seen for cultivated crop seed. The entire final percentage germination response to temperature in water was well described by two probit curves, and this model was extended to describe the data at all water potentials at a temperature close to the optimum. The implications of the reduction in germination at nonoptimal temperatures are discussed with respect to the interpretation of germination progress curves and conditional dormancy. After adjusting for maximum percentage germination, a hydrothermal time model was found to fit the data set well within the conditions normally encountered in horticultural seedbeds. This separation of the final percentage germination presents a flexible modelling approach that allows for the different levels of dormancy typically expressed within weed populations. By contrast with many previously reported species, S. media had a synchronous germination rate within the population at any given temperature/water potential combination. This synchronous germination of at least a proportion of the population over a wide range of temperature and water potentials might have ecological significance for the opportunistic germination behaviour of this weed species.

Effects of glutamine supplementation of an amino acid-based purified diet on intestinal mucosal integrity in cats with methotrexate-induced enteritis.

OBJECTIVE: To determine effects of glutamine-supplemented and glutamine-free amino acid-based purified diets, compared with a dry expanded diet, on intestinal structure and function in a model that used cats with methotrexate-induced enteritis. ANIMALS: 18 adult specific-pathogen-free cats. PROCEDURE: 12 cats were given intragastric feedings of an amino acid-based purified diet supplemented with glutamine (7% [wt:wt]) or an isonitrogenous amount of glycine and alanine; 6 cats consumed a dry expanded diet. After 21 days, cats received methotrexate (MTX; 11 mg/kg of body weight, IV). Intestinal permeability testing was performed immediately before and 66 hours after MTX administration. Celiotomy was performed 72 hours after MTX administration for aseptic removal of mesenteric lymph nodes, collection of full-thickness intestinal biopsy specimens, determination of intestinal cellular proliferation, and collection of aortic and portal venous blood samples for determination of arteriovenous amino acid concentrations across the intestine. RESULTS: Administration of MTX was associated with severe enterotoxicosis manifested as diarrhea (8/12 cats), vomiting (12/12), and positive results for bacterial culture of mesenteric lymph nodes (12/12) in cats receiving the purified diets, independent of glutamine supplementation. Diet did not affect villus tip length and villus surface area in the small intestine or cellular proliferation. Administration of MTX was associated with significantly increased intestinal permeability, which was not attenuated by glutamine supplementation. CONCLUSIONS: Feeding of a glutamine-supplemented amino acid-based purified diet was unable to preserve intestinal function in cats with MTX-induced enteritis. CLINICAL RELEVANCE: Intestinal morphologic alterations correlate poorly with intestinal function as measured by means of bacterial translocation and intestinal permeability.

Self-reported tooth loss and bone mineral density in older men and women.

It has been reported that postmenopausal women with osteoporosis have a higher than expected number of dentures and fewer teeth than women without osteoporosis. The relationship between self-reported tooth loss and bone mineral density (BMD) at the hip and spine in 608 men and 874 women, aged 65-76 years, was examined in a cross-sectional study. BMD was measured using dual X-ray absorptiometry. Twenty-four per cent of men and 27% of women had no natural teeth. There was a consistent decrease in BMD with increasing numbers of teeth lost in men. This relationship was independent of age, body mass index and smoking habit (trochanter r = -0.14, p < 0.0005; Ward's triangle r = -0.1, p < 0.005; and lumbar spine r = -0.07, p < 0.05) with between 5% and 9% difference in mean BMD at various sites between men who had all their teeth and men who had no teeth. There was no significant association between self-reported tooth loss and BMD in women. Tooth loss is associated with lower BMD in men; this relationship is less consistent in women.

Choledocholithiasis in Chinese immigrants with cholelithiasis.

During the period from January 1987 to December 1989, admissions for biliary tract disease at the New York Infirmary--Beekman Downtown Hospital were split almost evenly between Chinese immigrants from southeast Asia and all other ethnic groups (Caucasian, Hispanic, black, et cetera). However, the incidence of choledocholithiasis in patients undergoing cholecystectomy for cholelithiasis was much higher in the Chinese immigrant population, 37.2 versus 11.8 per cent, a highly significant difference (p = 0.001). In addition, we often found the disease to be of greater severity in Chinese patients. They were more likely to have large numbers of stones in the duct and more likely to have significant ductal enlargement. This increased risk was essentially constant regardless of age. Because of this threefold risk of choledocholithiasis when operating on a Chinese immigrant from southeast Asia for cholelithiasis, intraoperative cholangiography is mandatory, even in those without other indications for common bile duct exploration.

Prevalence, mortality and control of hypertensive disease in Australia.

Hypertensive diseases have long been recognized as a major medical problem in Australia, but until the 1950s measures for controlling hypertension were limited and of doubtful effectiveness. Great efforts were made to identify and deal with such remediable primary causes as unilateral renal disease, endocrine disorders of the adrenal cortex and medulla and coarctation of the aorta, but the yield was small and there was little to offer the great majority of patients who were suffering from essential hypertension, including its malignant form. Long holidays, especially sea cruises, sedation and venesection were widely prescribed but with little confidence and even less benefit.

Pleiotropic aspartate taxis and serine taxis mutants of Escherichia coli.

Mutants that at one time were thought to be specifically defective in taxis toward aspartate and related amino acids (tar mutants) or specifically defective in taxis toward serine and related amino acids (tar mutants) are now shown to be pleiotropic in their defects. The tar mutants also lack taxis toward maltose and away from Co2+ and Ni2+. The tsr mutants are altered in their response to a variety of repellents. Double mutants (tar tsr) fail in nearly all chemotactic responses. The tar and tsr mutants provide evidence for two complementary, converging pathways of information flow: certain chemoreceptors feed information into the tar pathway and others into the tsr pathway. The tar and tsr products have been shown to be two different sets of methylated proteins.