Histiocytic sarcomas in flat-coated retrievers: a summary of 37 cases (November 1998-March 2005)

Thirty-seven cases of histiocytic-like sarcomas (HLSs) in flat-coated retriever dogs were evaluated retrospectively. This tumour accounted for 36% of the malignant tumours seen in this breed during the study period. The median age at presentation was 8.2 years. Thirty-four dogs presented with a swelling or mass in a muscle group or surrounding a joint. The remaining three presented for rib (1), cutaneous (1) or primary splenic origin (1). A high rate of metastasis to local lymph nodes (45%), thorax (20%) and abdominal organs (20% confirmed) was seen. Overall metastastic rate by the time of death was 70%. The median survival for all dogs was 123 days. The most significant prognostic indicator was presence of distant metastasis at the time of diagnosis with median survival of 68 or 200 days, with or without metastasis, respectively. Chemotherapy and radiation therapy significantly improved survival. Dogs given chemotherapy survived a median of 185 versus 34 days for dogs that were not (P = 0.0008). Dogs treated with radiation survived a median of 182 versus 60 days for those that were not (P = 0.0282). Dogs receiving only palliative therapy survived a median of 17 versus 167 days in dogs receiving any kind of radiation, chemotherapy, surgery or combinations. A set protocol of radiation and CCNU (RTCCNU) induced minimal toxicity and provided a median survival of 208 versus 68 days for all other dogs. While this tumour carries a poor long-term prognosis in flat-coated retrievers, it is reasonable to treat these dogs for palliation of signs and extension of life.

Fisher-Lewis kidney transplantation model as a tool for investigation of transplantation-induced cardiomyopathy

BACKGROUND

Cardiovascular disease is a major cause of death after kidney transplantation; thus, cardiovascular protection is a major concern in transplant recipients. Data about cardiac characteristics from animal models after kidney transplantation are lacking. Therefore, we investigated cardiac structure and function in a model of chronic allograft injury.

METHODS

Kidneys from Fisher 344 rats were orthotopically transplanted into Lewis rats. Eight recipient rats were treated with placebo or an angiotensin II type-1 receptor blocker (AT1RB; candesartan cilexitil, 5 mg/kg/d) for 24 weeks posttransplantation, and 8 untreated matched Lewis rats were used as healthy controls. Echocardiography was performed at 24 weeks posttransplantation to measure ejection fraction, fractional shortening, and left ventricular mass, in triplicate. Proteinuria at 24 hours was determined, and after harvesting, the heart weight-body weight ratio (HW/BW) was measured.

RESULTS

At 24 weeks posttransplantation, renal transplant-recipient rats demonstrated a significantly decreased ejection fraction (mean [SD], 58.9% [3.2%] vs 70.7% [2.1%]) and fractional shortening (29.8% [2.0%] vs 38.3% [2.0%]) and increased HW/BW and left ventricular mass (7.7 [0.2] cm(3) vs 6.7 [0.2] cm(3)) compared with healthy control rats. The HW/BW and left ventricular mass were significantly ameliorated by AT1RB compared with placebo-treated transplant-recipient rats (6.8 [0.2] cm(3) vs 7.7 [0.2] cm(3)). In addition, decreased proteinuria was evident after AT1RB.

CONCLUSION

The Fisher-Lewis rat kidney transplantation model resulted in cardiac hypertrophy and decreased cardiac function. AT1RB normalized cardiac hypertrophy without improving function. These findings demonstrate that the Fisher-Lewis rat renal transplantation model can be used to investigate transplantation-induced cardiomyopathy.

Caries prevalence in 2-year-old children in the city of Zurich

OBJECTIVES

To establish caries prevalence in 2-year-olds in the city of Zurich; and to investigate the relationship between caries prevalence and dietary habits, and oral hygiene practices in native children and children with immigrant background.

METHOD

1,000 randomly selected 2-year-olds were invited to participate in a clinical examination, at which parents were interviewed about the child's oral hygiene and dietary habits. Caries diagnosis was based on visual inspection of all tooth surfaces and included both initial (d1) and cavitated (d2) lesions. Univariate and multivariate logistic regressions for two subgroups of children (children of Swiss and foreign-born mothers) were performed in order to assess the association between predictor variables and caries.

RESULTS

771 children were examined (participation rate 78%; mean age 2.4 years (age range 2.06-2.90 years)). Although the majority (94%) was born in Switzerland, 61% of children had immigrant backgrounds (mother not born in Switzerland). Cavitated teeth (d2mft) were observed in 12.6% of children (95% CI: 10.4-15.1%). Caries including initial lesions (dl2mft) affected 25.3% of children (95% CI: 22.4-28.5%). There were 34 (4.4%) children with severe caries (all maxillary incisors cavitated). For children with caries, the mean d2mft was 4.3 (+/- 2.8). Children with foreign-born mothers (mothers not born in Switzerland) exhibited a significantly higher caries prevalence than those with Swiss-born mothers (17.4% versus 5.0% with d2mft > 0).

CONCLUSIONS

Children with foreign-born mothers exhibited significantly higher caries prevalence rates than those with Swiss-born mothers. Poor oral hygiene and night-time bottle use were identified as risk indicators for caries in all children. Further risk indicators identified in children of foreign-born mothers were a preference for sugar-containing non-milk drinks, no pacifier use, child's age and male gender.

Scanning mass spectrometer for quantitative reaction studies on catalytically active microstructures

We describe an apparatus for spatially resolving scanning mass spectrometry which is able to measure the gas composition above catalytically active microstructures or arrays of these microstructures with a lateral resolution of better than 100 mum under reaction conditions and which allows us to quantitatively determine reaction rates on individual microstructures. Measurements of the three-dimensional gas composition at different vertical distances and separations between active structures allow the evaluation of gas phase mass transport effects. The system is based on a piezoelectrically driven positioning substage for controlled lateral and vertical positioning of the sample under a rigidly mounted capillary probe connecting to a mass spectrometer. Measurements can be performed at pressures in the range of <10(-2)-10 mbars and temperatures between room temperature and 450 degrees C. The performance of the setup is demonstrated using the CO oxidation reaction on Pt microstructures on Si with sizes between 100 and 300 mum and distances in the same order of magnitude, evaluating CO(2) formation and CO consumption above the microstructures. The rapidly decaying lateral resolution with increasing distance between sample and probe underlines the effects of (lateral) gas transport in the room between sample and probe. The reaction rates and apparent activation energy obtained from such measurements agree with previous data on extended surfaces, demonstrating the feasibility of determining absolute reaction rates on individual microstructures.

Interrelation of peri-operative morbidity and ASA class assignment in patients undergoing gynaecological surgery

OBJECTIVE

The aim of this study was to estimate intra- and post-operative risk using the American Society of Anaesthesiologists (ASA) classification which is an important predictor of an intervention and of the entire operating programme.

STUDY DESIGN

In this retrospective study, 4435 consecutive patients undergoing elective and emergency surgery at the Gynaecological Clinic of the University Hospital of Zurich were included. The ASA classification for pre-operative risk assessment was determined by an anaesthesiologist after a thorough physical examination. We observed several pre-, intra- and post-operative parameters, such as age, body-mass-index, duration of anaesthesia, duration of surgery, blood loss, duration of post-operative stay, complicated post-operative course, morbidity and mortality. The investigation of different risk factors was achieved by a multiple linear regression model for log-transformed duration of hospitalisation.

RESULTS

Age and obesity were responsible for a higher ASA classification. ASA grade correlates with the duration of anaesthesia and the duration of the surgery itself. There was a significant difference in blood loss between ASA grades I (113+/-195 ml) and III (222+/-470 ml) and between classes II (176+/-432 ml) and III. The duration of post-operative hospitalisation could also be correlated with ASA class. ASA class I=1.7+/-3.0 days, ASA class II=3.6+/-4.3 days, ASA class III=6.8+/-8.2 days, and ASA class IV=6.2+/-3.9 days. The mean post-operative in-hospital stay was 2.5+/-4.0 days without complications, and 8.7+/-6.7 days with post-operative complications. Multiple linear regression model showed that not only the ASA classification contained an important information for the duration of hospitalisation. Parameters such as age, class of diagnosis, post-operative complications, etc. also have an influence on the duration of hospitalisation.

CONCLUSION

This study shows that the ASA classification can be used as a good and early available predictor for the planning of an intervention in gynaecological surgery. The ASA classification helps the surgeon to assess the peri-operative risk profile of which important information can be derived for the planning of the operation programme.

Comparative quantitative assessment of GnRH- and LH-receptor mRNA expression in the urinary tract of sexually intact and spayed female dogs

Ovariectomy interrupts the regulatory loop in the hypothalamus-pituitary-gonad axis, leading to a several-fold increase in gonadotropin levels. This rise in hormonal secretion may play a causal role in ovariectomy-related urinary incontinence. The purpose of this study was to examine the effect of ovariectomy in bitches on the expression of GnRH- and LH-receptors in the lower urinary tract, and assess the relationship between receptor expression and plasma gonadotropin concentrations. Plasma gonadotropins were measured in 37 client-owned bitches. Biopsies were harvested from the mid-ventral bladder wall in all dogs, and from nine further locations within the lower urinary tract in 17 of the 37 animals. Messenger RNA of the LH and GnRH receptors was quantified using RT-PCR with the TaqMan Universal PCR Master Mix. Gonadotropins were measured with a canine-specific FSH-immunoradiometric assay and LH-radioimmunoassay. The hierarchical mixed ANOVA model using MINITAB, Mann-Whitney U-test, unpaired means comparison and linear regressions using StatView were applied for statistical analyses. Messenger RNA for both receptors was detected in all biopsy samples. Age was negatively correlated to mRNA expression of the LH and the GnRH receptors. A relationship between the mRNA values and the plasma gonadotropin concentrations was not established. Evaluation of results within each of the biopsy locations revealed greater LH-receptor expression in the proximal second quarter of the urethra in spayed bitches than in intact bitches (P=0.0481). Increased mRNA expression of LH receptors in this location could possibly play a role in the decrease in closing pressure of the urethra following ovariectomy.

Angiotensin type 1 and type 2 receptor blockade in chronic allograft nephropathy

Angiotensin-II (Ang-II) type 1 (AT(1)) receptor blockers may delay the progression of chronic allograft nephropathy (CAN). However, neither the optimal time for initiating AT(1) receptor blockade in order to delay CAN potentially nor the role of Ang-II type 2 (AT(2)) receptors under AT(1) receptor blockade is known. Both AT receptors can regulate p53 expression and apoptosis. We investigated what time of initiation with AT(1) blockers most effectively delayed CAN as well as the role of the AT(2) receptor, and how angiotensin receptor blockade affected apoptosis and its regulating factors in this context in a rat model. Kidneys of Fisher (F344) rats were transplanted into Lewis rats. Animals were treated with AT(1) (candesartan) and/or AT(2) (PD123319) receptor antagonists, a calcium channel blocker, or vehicle (treatment periods: day -7 before to week 24 after transplantation (long term), week 12 to week 24 (late), day -7 to day +5 (early)) and observed the animals for 24 weeks. Reduction of proteinuria, grade of CAN, and number of apoptotic cells was most pronounced in animals receiving long-term AT(1) receptor blockade. A combined AT(1)/AT(2) blocker treatment reduced CAN similarly to AT(1) blocker treatment alone. The number of apoptotic cells and the level of p53 mRNA were significantly lower in long-term AT(1) blocker-treated animals. In summary, AT(1) receptor blockade delayed the progression of CAN, particularly in animals treated long term. Reduction of apoptosis could be related to these beneficial effects. The AT(2) receptor does not appear to play an important role in CAN.