Complete duodenal necrosis associated with non-traumatic duodenal hematoma requiring emergent pancreatico-duodenectomy.

INTRODUCTION: Duodenal necrosis is a rare complication of acute pancreatitis but can occur given the shared blood supply to the head of the pancreas and the duodenum. PRESENTATION OF CASE: A 55-year-old male presented with acute-on-chronic pancreatitis and a duodenal hematoma. The hematoma expanded to occlude the biliary tree and, shortly after, the duodenum necrosed and perforated. The patient required an emergent pancreaticoduodenectomy performed in two stages. DISCUSSION: Surgical management is complex and a difficult challenge for a general surgeon. Many advocate for wide drainage to create a controlled fistula using a malecot through the wall defect/separate duodenotomy/a retrograde jejunostomy tube. This case represents an extreme variation on this issue which was best managed by definitive resection given the extent of the necrosis. CONCLUSION: This case report demonstrates that duodenal hematoma and necrosis should be recognized as part of the spectrum of consequences of acute pancreatitis. General surgeons should have a surgical approach to this complication whether that be diversion or definitive resection.

An Update on the Effect of Clinical Mastitis on the Welfare of Dairy Cows and Potential Therapies.

Despite the widespread implementation of mastitis control programs, mastitis is the most common and one of the costliest diseases in the dairy industry, with broad-ranging impacts and consequences. Recent technological advances have allowed researchers to assess the effects of mastitis on animal behavior and welfare, and the efficacy of mastitis treatments. Several nonsteroidal anti-inflammatory drugs are available as supportive therapies for clinical mastitis. This article focuses on recent advances in the assessment, therapy, and effects of mastitis on cow behavior and welfare.

Early Rescue from Acute Severe Clostridium Difficile: A Novel Treatment Strategy.

BACKGROUND: Severe Clostridium difficile infections (CDI) can lead to significant impediments to effective treatment. We developed a novel treatment protocol utilizing bedside gastrointestinal lavage (GIL) for the management of patients with severe, complicated CDI. We describe the development and early outcomes of non-operative bedside GIL in hospitalized patients with severe, complicated CDI following the Idea, Development, Exploration, Assessment, Long Term Study (IDEAL) framework at the Idea stage. We compared our results with those of a cohort of patients managed with colectomy. METHODS: We conducted a retrospective cohort study of hospitalized patients with severe, complicated CDI who failed conventional medical therapy and were referred for surgical consultation at two academic tertiary-care hospitals between January 2009 and January 2015. After surgical assessment, the attending surgeon decided to proceed either with bedside GIL or directly to colectomy. Bedside GIL involved nasojejunal tube insertion followed by flushing with 8 L of polyethylene glycol 3350/electrolyte solution over 48 h. Both patient groups received standard medical treatment with vancomycin 500 mg q 6 h enterally and metronidazole 500 mg intravenously three times daily for 14 d. The main outcomes of interest were the incidence of colectomy, complications, and mortality rate. RESULTS: Nineteen and seventeen patients underwent GIL and direct colectomy, respectively. There were no significant differences between the groups in terms of demographics, American Society of Anesthesiologists class, disease severity, need for intensive care unit admission, mechanical ventilation, vasopressor use, serum lactate concentration, or proportion presenting with hypotension, acute kidney injury, or a white blood cell count >16,000/mcL or <4,000/mcL (p > 0.1). The in-hospital mortality rate was 26% (5/19) and 41% (7/17) for the GIL and colectomy groups, respectively (p = 0.35). Only one patient in the GIL group failed the protocol, requiring colectomy. There were no significant differences in complications in the two groups. CONCLUSIONS: Bedside GIL appeared to be safe for the treatment of patients with severe, complicated CDI who had failed conventional medical therapy. It did not appear to increase the risk of morbidity or death compared with the traditional strategy of proceeding directly to colectomy.

Gastric outlet obstruction by a lost gallstone: Case report and literature review.

INTRODUCTION: Spilled gallstones from a laparoscopic cholecystectomy can be a source of significant morbidity, most commonly causing abscesses and fistulae. Preventative measures for loss, careful removal during the initial surgery, and good documentation of any concern for remaining intraperitoneal stones needs to be performed with the initial surgery. CASE REPORT: An 80-year-old male with a history of complicated biliary disease resulting in a cholecystectomy presented to general surgery clinic with increasing symptoms of gastric outlet obstruction. CT imaging was concerning for a malignant process despite negative biopsies. A distal gastrectomy and Billroth II reconstruction was performed and final pathology showed dense inflammation with a single calcified stone incarcerated within the gastric wall of the inflamed pylorus and no malignancy. DISCUSSION: Stones lost during laparoscopic cholecystectomy are not innocuous and preventative measures for loss, careful removal during the initial surgery, and good documentation of any concern for remaining intraperitoneal stones. CONCLUSION: This is the first case of gastric outlet obstruction caused by an intramural obstruction of the pylorus from a spilled gallstone during a laparoscopic cholecystectomy and subsequent inflammation. This is an etiology that must be considered in new cases of gastric outlet obstruction and can mimic malignancy.

Preclinical Evidence That 5-HT1B Receptor Agonists Show Promise as Medications for Psychostimulant Use Disorders.

Background: 5-HT1B receptor agonists enhance cocaine intake during daily self-administration sessions but decrease cocaine intake when tested after prolonged abstinence. We examined if 5-HT1B receptor agonists produce similar abstinence-dependent effects on methamphetamine intake. Methods: Male rats were trained to self-administer methamphetamine (0.1 mg/kg, i.v.) on low (fixed ratio 5 and variable ratio 5) and high (progressive ratio) effort schedules of reinforcement until intake was stable. Rats were then tested for the effects of the selective 5-HT1B receptor agonist, CP 94,253 (5.6 or 10 mg/kg), or the less selective but clinically available 5-HT1B/1D receptor agonist, zolmitriptan (10 mg/kg), on methamphetamine self-administration both before and after a 21-day forced abstinence period during which the rats remained in their home cages. Results: The inverted U-shaped, methamphetamine dose-response function for intake on the fixed ratio 5 schedule was shifted downward by CP 94,253 both before and after abstinence. The CP 94,253-induced decrease in methamphetamine intake was replicated in rats tested on a variable ratio 5 schedule, and the 5-HT1B receptor antagonist SB 224,289 (10 mg/kg) reversed this effect. CP 94,253 also attenuated methamphetamine intake on a progressive ratio schedule both pre- and postabstinence. Similarly, zolmitriptan attenuated methamphetamine intake on a variable ratio 5 schedule both pre- and postabstinence, and the latter effect was sustained after each of 2 more treatments given every 2 to 3 days prior to daily sessions. Conclusions: Unlike the abstinence-dependent effect of 5-HT1B receptor agonists on cocaine intake reported previously, both CP 94,253 and zolmitriptan decreased methamphetamine intake regardless of abstinence. These findings suggest that 5-HT1B receptor agonists may have clinical efficacy for psychostimulant use disorders.

Effects of tulathromycin on incidence of various diseases and growth of young heifers.

OBJECTIVE: To determine the effects of administration of 1 dose of tulathromycin on the incidence of various diseases and growth, identify risk factors for slow growth, and determine the association of Mycoplasma bovis status with the incidence of otitis media in calves. DESIGN: Randomized controlled trial and cross-sectional study. ANIMALS: 788 dairy heifer calves (median age, 3 days). PROCEDURES: Calves received tulathromycin or a saline (0.9% NaCl) solution control treatment once. Calves were observed daily for 8 weeks by farm staff to detect diseases. Nasal swab specimens were collected from some calves for Mycoplasma spp culture. RESULTS: Tulathromycin-treated calves had significantly lower odds of developing otitis media (OR, 0.41; 95% confidence interval, 0.58 to 0.82) versus control calves. Control calves had significantly higher odds of developing diarrhea (OR, 1.8; 95% confidence interval, 1.2 to 2.6) versus tulathromycin-treated calves. Control calves and those with failure of passive transfer, fever, lameness, respiratory tract disease, or diarrhea had significantly lower average daily gain versus other calves. Seventeen of the 66 (26%) calves that underwent repeated testing had positive Mycoplasma spp culture results, but positive results were not associated with otitis media. One of 42 calves with otitis media tested for Mycoplasma spp had positive results, and 1 of 43 age-matched calves without otitis media had positive results. CONCLUSIONS AND CLINICAL RELEVANCE: Tulathromycin-treated calves in this study had a lower incidence of diarrhea and otitis media versus control calves. Various diseases had negative effects on average daily gain. Mycoplasma bovis status was not associated with otitis media in calves.

Associations of herd- and cow-level factors, cow lying behavior, and risk of elevated somatic cell count in free-stall housed lactating dairy cows.

Recent evidence suggests that the risk of intramammary infection in dairy cows is related to lying patterns. The objectives of this study were to quantify the standing and lying behavior of dairy cows milked 3×/d, determine the cow- and herd-level factors associated with these behaviors, and relate these findings to the risk of an elevated somatic cell count (SCC). Five commercial free-stall dairy herds in Eastern Ontario, milking 3×/d, were enrolled in a longitudinal study. Forty Holstein-Friesian cows/herd were randomly selected as focal animals based on days in milk (<200 d) and SCC (<100,000 cells/mL). Farms were followed for 4, 5-week periods. Individual-cow SCC was recorded at the beginning of each period and end of the final period. Elevated SCC (eSCC) was used as an indicator of subclinical mastitis. A new incident eSCC was defined as an individual cow that started the period with a SCC <100,000 cells/mL but whose next SCC exceeded 200,000 cells/mL. Lying behavior was recorded 5d after each milk sampling using data loggers. For these 5d, individual milking times and feeding times were also recorded. On d1 of each recording period 2 trained observers scored focal cows for hygiene and lameness. Throughout the course of the study, cows averaged 11.2h/d of lying time, split into 8.6 lying bouts/d that were on average 84.6 min in length. Later lactation cows had longer daily lying times that were split into fewer lying bouts of longer duration than cows earlier in lactation. Lame cows had longer daily lying times and lying bout durations than non-lame cows. Cows with greater milk yield had lower lying times than lower producing cows. Average post-milking standing time across the study herds was 103 min. Manipulation of feed (feed delivery or push-up) by the stockperson, in the hour before milking or shortly thereafter, resulted in the longest post-milking standing times. Over the study period, 48 new eSCC were detected, resulting in a mean herd incidence rate of 0.91 eSCC/cow-year at risk for all study herds. A non-linear relationship between post-milking standing time and eSCC incidence was found; compared to those cows that lie down <90 min after milking, cows that lie down for the first time >90 min after milking had a lower risk of acquiring a new eSCC. The risk of experiencing an eSCC was also increased in multiparous cows, and in those cows with a higher SCC at the beginning of the study. These results indicate that management practices that promote post-milking standing time, such as the manipulation of feed delivery around milking times, should be encouraged to reduce the risk of cows experiencing new eSCC.

Assessment and management of pain in dairy cows with clinical mastitis.

It is clear that clinical mastitis has severe detrimental effects on the animal and negative economic impacts for dairy producers. However, pain associated with clinical mastitis, generally, is not measured and not treated. Attention to behavioral and physiologic indicators should be used to monitor animal health. New technologies may allow dairy producers to identify clinical mastitis in its very early stages, or even before clinical changes occur. Furthermore, automated measures of activity, such as step counts and lying time, show promise as predictors of clinical problems. These new technologies, in addition to other automated measures, have the potential for improving the screening methods for preclinical mastitis and accurately predicting the onset of a clinical mastitis event. With this opportunity for very early detection of infection, there is a potential for early intervention with NSAID therapy, which may allow for maximum efficacy from its use. Despite which specific NSAID is used, it is clear that the benefits on temperature, rumen function, SCC, milk production, behavior, and pain sensitivity in animals during mastitis indicate that this therapy has a role throughout the dairy industry. As the health and well-being of dairy cattle continue to be scrutinized by consumer groups, it is essential that the alleviation of any perceived pain or discomfort associated with clinical mastitis should be addressed.

The script concordance test as a measure of clinical reasoning: a national validation study.

INTRODUCTION: The script concordance test (SCT) is an innovative tool for clinical reasoning assessment. It has previously been shown to be a reliable and valid measure of clinical reasoning among general surgical residents. PURPOSE: To determine if the SCT maintained its validity and reliability when administered on a national level. METHODS: The test was administered to 202 residents (51 R1, 45 R2, 45 R3, 28 R4, and 33 R5) in 9 general surgery programs across Canada. RESULTS: The optimized version of the test had a reliability (Cronbach alpha) of .85. Scores increased progressively from R1 (64.5 ± 7.6) to R2 (69.5 ± 5.8) to R3 (69.9 ± 6.7) to R4 (72.0 ± 6.2) with a dip in the R5s (68.3 ± 8.6). The test was able to differentiate junior (R1+ R2 = 66.8 ± 7.2) from senior residents (R3 + R4 + R5 = 70.0 ± 7.3, P = .001) across all the programs. CONCLUSIONS: The SCT maintained its reliability and validity as a measure of intraoperative clinical reasoning among general surgical residents when administered across multiple centers. We believe that the SCT can be developed to measure clinical reasoning in high-stakes national examinations.

Stat3 mediates expression of autotaxin in breast cancer.

We determined that signal transducer and activator of transcription 3 (Stat3) is tyrosine phosphorylated in 37% of primary breast tumors and 63% of paired metastatic axillary lymph nodes. Examination of the distribution of tyrosine phosphorylated (pStat3) in primary tumors revealed heterogenous expression within the tumor with the highest levels found in cells on the edge of tumors with relatively lower levels in the central portion of tumors. In order to determine Stat3 target genes that may be involved in migration and metastasis, we identified those genes that were differentially expressed in primary breast cancer samples as a function of pStat3 levels. In addition to known Stat3 transcriptional targets (Twist, Snail, Tenascin-C and IL-8), we identified ENPP2 as a novel Stat3 regulated gene, which encodes autotaxin (ATX), a secreted lysophospholipase which mediates mammary tumorigenesis and cancer cell migration. A positive correlation between nuclear pStat3 and ATX was determined by immunohistochemical analysis of primary breast cancer samples and matched axillary lymph nodes and in several breast cancer derived cell lines. Inhibition of pStat3 or reducing Stat3 expression led to a decrease in ATX levels and cell migration. An association between Stat3 and the ATX promoter, which contains a number of putative Stat3 binding sites, was determined by chromatin immunoprecipitation. These observations suggest that activated Stat3 may regulate the migration of breast cancer cells through the regulation of ATX.

Differential interleukin-6/Stat3 signaling as a function of cellular context mediates Ras-induced transformation.

INTRODUCTION: Tyrosine phosphorylated signal transducer and activator of transcription 3 (pStat3) is present in numerous cancers and is required for mediating tumorigenesis. Autocrine and paracrine interleukin (IL)-6 signaling is the principal mechanism by which Stat3 is persistently phosphorylated in epithelial tumors including breast, lung, colon and gastric cancer. The Ras oncogene mediates cellular transformation without evidence of pStat3 in cultured cells. Recently, however non-tyrosine phosphorylated Stat3 was shown to have a transcriptional activating function, a role in mitochondrial function and to mediate cell migration.. Here we examined the role of Stat3 in Ras mediated transformation. METHODS: Ha-rasV12 transformed mammary epithelial cells (MCF10A) cells were transduced with a Stat3shRNA, IL-6shRNA and/or treated with inhibitors of Janus kinases (JAKs) to examine the role of the IL-6 signaling pathway in Ras mediated invasion and tumorigenesis. RESULTS: Cellular migration, invasion, anchorage independent growth and tumorigenesis were largely abrogated in the Stat3-reduced cells compared to control cells. Analysis of MCF10A-Ras tumors revealed high levels of pStat3 and interleukin-6. Tumors derived from transgenic MMTV-K-Ras mice were also found to express pStat3 and IL-6. MCF10A-Ras cells, when grown in a three-dimensional Matrigel culture system revealed the appearance of the junctional protein E-Cadherin as a consequence of reducing Stat3 levels or inhibiting Stat3 activity. Decreasing IL-6 levels in the MCF10A-Ras cells abrogated tumorigenesis and reduced cell migration. By isolating Ras-expressing primary tumors and serially passaging these cells in two-dimensional culture led to a decrease in IL-6 and pStat3 levels with the reappearance of E-Cadherin. CONCLUSIONS: The cellular and environmental context can lead to differential IL-6/pStat3 signaling and a dependency on this cytokine and transcription factor for migration, invasion and tumorigenesis.

Safety of a progesterone-releasing intravaginal device as assessed from vaginal mucosal integrity and indicators of systemic inflammation in postpartum dairy cows.

A clinical trial was conducted to investigate the animal safety of a progesterone-releasing intravaginal device (PRID). Anestrus cows at a mean of 63 +/- 3.5 d in milk were randomly assigned to an ovulation-synchronization protocol that included placement of either a PRID or a placebo intravaginal device (PID) or no such treatment. At enrolment and at device removal 7 d later, blood samples were collected. The outcomes of interest included the vaginal reaction to the device, the vaginal mucosal integrity, and the results of bacterial culture of swabs of the vaginal mucosa. In addition, the leukocyte and haptoglobin responses were measured. Although only 5% of the PRID-treated animals compared with 19% of the PID-treated animals had a copious purulent vaginal discharge at the time of device removal, there was no significant difference in the proportions; furthermore, there was no evidence of vaginal mucosal damage associated with either device. The total blood leukocyte count was significantly lower in both the PRID-treated cows and the PID-treated cows after device removal compared with the start of treatment (P < 0.05) and compared with no treatment (P < 0.001); there was no difference in leukocyte response between the 2 device-treated groups. The decrease in leukocyte count was attributed to a significant reduction in the numbers of circulating neutrophils and lymphocytes, a pattern consistent with the luteal phase of the bovine estrus cycle. There was no significant difference in the circulating haptoglobin concentration between the 3 groups of cows. Culture revealed commensal bacterial growth in the vagina of all the cows.

Association between management practices and within-herd prevalence of Cryptosporidium parvum shedding on dairy farms in southern Ontario.

To identify management practices associated with an increased within-herd prevalence of Cryptosporidium parvum shedding on dairy farms in southern Ontario, fecal samples were taken from 1089 calves aged 7-28 days, from 119 herds. Information on management practices was obtained by administering a questionnaire compiled using a modified Delphi technique. Data were analyzed using univariable and multivariable negative binomial regression. Overall, 30% of the calves in the study were shedding C. parvum oocysts, with at least one positive calf detected in 77% of herds. Within-herd prevalence ranged from 0 to 80%. Predictors significantly associated with an increased prevalence of shedding in multivariable modelling were the use of calf scour prophylaxis in cows (risk ratio [RR] 1.70, P<0.01) and calves (RR 1.38, P=0.02) and the feeding of milk replacer in the first week of life (RR 1.40, P=0.02). In contrast, the presence of concrete flooring in calf housing areas (RR 0.59, P<0.01) and the use of soap or detergent when washing calf feeding utensils (RR 0.61, P<0.01) appeared to be protective.

Mutations in the EGFR kinase domain mediate STAT3 activation via IL-6 production in human lung adenocarcinomas.

Persistently activated or tyrosine-phosphorylated STAT3 (pSTAT3) is found in 50% of lung adenocarcinomas. pSTAT3 is found in primary adenocarcinomas and cell lines harboring somatic-activating mutations in the tyrosine kinase domain of EGFR. Treatment of cell lines with either an EGFR inhibitor or an src kinase inhibitor had no effect on pSTAT3 levels, whereas a pan-JAK inhibitor (P6) blocked activation of STAT3 and inhibited tumorigenesis. Cell lines expressing these persistently activated mutant EGFRs also produced high IL-6 levels, and blockade of the IL-6/gp130/JAK pathway led to a decrease in pSTAT3 levels. In addition, reduction of IL-6 levels by RNA interference led to a decrease in tumorigenesis. Introduction of persistently activated EGFR into immortalized breast epithelial cells led to tumorigenesis, IL-6 expression, and STAT3 activation, all of which could be inhibited with P6 or gp130 blockade. Furthermore, inhibition of EGFR activity in multiple cell lines partially blocked transcription of IL-6 and concurrently decreased production and release of IL-6. Finally, immunohistochemical analysis revealed a positive correlation between pSTAT3 and IL-6 positivity in primary lung adenocarcinomas. Therefore, mutant EGFR could activate the gp130/JAK/STAT3 pathway by means of IL-6 upregulation in primary human lung adenocarcinomas, making this pathway a potential target for cancer treatment.

Calf-level risk factors for neonatal diarrhea and shedding of Cryptosporidium parvum in Ontario dairy calves.

This work was conducted to investigate calf-level factors that influence the risk of neonatal diarrhea and shedding of Cryptosporidium parvum oocysts in calves, on dairy farms in Ontario with histories of calf diarrhea or cryptosporidiosis. Fecal samples were collected weekly for 4 weeks from each of 1045 calves under 30 days of age on 11 dairy farms in south-western Ontario during the summer of 2003 and the winter of 2004. A questionnaire designed to gather information on calf-level management factors was administered on farm for each calf in the study. Samples were examined for C. parvum oocysts by microscopy, and a subset of specimens was also tested for enterotoxigenic Escherichia coli, Salmonella, bovine rotavirus and bovine coronavirus. The consistency of each sample was scored and recorded at the time of collection in order to assess the presence or absence of diarrhea. In addition, a blood sample was taken from each calf upon enrollment in the study, for assessment of maternal antibody transfer and for polymerase chain reaction testing for persistent bovine viral diarrhea virus infection. Using the GLLAMM function in Stata 9.0, multilevel regression techniques were employed to investigate associations between management practices and the risk of C. parvum shedding or diarrhea. C. parvum oocysts were detected in the feces of 78% of the 919 calves from which all four fecal samples had been collected. Furthermore, 73% of the 846 calves for which all four fecal consistency scores had been recorded were diarrheic at the time of collection of at least one sample. Significant predictors of the calf-level risk of C. parvum shedding included the use of calf diarrhea prophylaxis in pregnant cows, and the type of maternity facilities in which the calves were born. Factors associated with an increased risk of diarrhea were leaving the calf with the dam for more than an hour after birth, and the birth of a calf in the summer as opposed to winter. Calves shedding C. parvum oocysts had 5.3 (95% CI 4.4, 6.4) times the odds of diarrhea than non-shedding calves, controlling for other factors included in the final multivariable model. Furthermore, infected calves shedding more than 2.2 x 10(5) oocysts per gram of feces were more likely to scour than infected calves shedding lower numbers of oocysts (OR= 6.1, 95% CI 4.8, 7.8). The odds of diarrhea in calves shedding oocysts that had been allowed to remain with their dams for more than an hour were higher than the odds of diarrhea in shedding calves that had been separated from their dams within an hour after birth.

Stat3 is tyrosine-phosphorylated through the interleukin-6/glycoprotein 130/Janus kinase pathway in breast cancer.

INTRODUCTION: Signal transducer and activator of transcription 3 (Stat3) is constitutively tyrosine-phosphorylated in approximately 50% of primary breast carcinomas. A number of different mechanisms responsible for Stat3 activation, including abnormal activation of receptor tyrosine kinases, Src, and Janus kinases (Jaks), have been implicated in breast cancer. METHODS: We examined six breast cancer-derived cell lines expressing high or low levels of tyrosine-phosphorylated Stat3 (pStat3) as well as primary breast cancer specimens. RESULTS: Inhibition of Src or EGFR (epidermal growth factor receptor) tyrosine kinases had no effect on pStat3 levels, whereas pan-Jak inhibitor P6 resulted in complete abrogation of Stat3 phosphorylation and inhibition of growth. Jaks are required for cytokine signaling, and the glycoprotein 130 (gp130) receptor-associated Jaks are known mediators of Stat3 phosphorylation. Blockade of the gp130 receptor or sequestration of the interleukin-6 (IL-6) ligand led to a decrease of pStat3 levels. Conditioned media from those cell lines expressing high levels of pStat3 contained IL-6 and were capable of stimulating Stat3 phosphorylation. We examined IL-6 levels in primary breast tumors and found a positive correlation between pStat3 and IL-6 expression. CONCLUSION: In summary, a principal mechanism of Stat3 activation in breast cancer is through the IL-6/gp130/Jak pathway.

Constitutively activated Stat3 induces tumorigenesis and enhances cell motility of prostate epithelial cells through integrin beta 6.

The persistent activation of signal transducer and activator of transcription 3 (Stat3) is a common feature of prostate cancer. However, little is known about the Stat3 targets that may mediate prostate tumorigenesis. The introduction of an activating mutant form of Stat3 (Stat3-C) into immortalized prostate epithelial cells resulted in tumorigenesis. Stat3-C-expressing cells had decreased E-cadherin levels, increased numbers of lamellipodia and stress fibers, and enhanced migratory capacities compared to vector control-expressing cells, with a concomitant increase in the expression of integrin beta6 and its ligand, fibronectin (FN). Exogenously added FN increased cellular migration, with a concomitant loss of E-cadherin expression. The blockade of integrin alphavbeta6 in Stat3-C-expressing cells inhibited migration, increased E-cadherin levels, and reduced colony formation in soft agar. These results demonstrate the sufficiency of constitutively activated Stat3 in mediating prostate tumorigenesis and identify novel Stat3 targets that are involved in promoting cell migration and transformation.

Cyclin D1 is transcriptionally regulated by and required for transformation by activated signal transducer and activator of transcription 3.

Signal transducers and activators of transcription 3 (STAT3) is a transcription factor that is aberrantly activated in many cancer cells. Constitutively activated STAT3 is oncogenic, presumably as a consequence of the genes that it differentially regulates. Activated STAT3 correlated with elevated cyclin D1 protein in primary breast tumors and breast cancer-derived cell lines. Cyclin D1 mRNA levels were increased in primary rat-, mouse-, and human-derived cell lines expressing either the oncogenic variant of STAT3 (STAT3-C) or vSrc, which constitutively phosphorylates STAT3. Mutagenesis of STAT3 binding sites within the cyclin D1 promoter and chromatin immunoprecipitation studies showed an association between STAT3 and the transcriptional regulation of the human cyclin D1 gene. Introduction of STAT3-C and vSrc into immortalized cyclin D1(-/-) and cyclin D1(-/+) fibroblasts led to anchorage-independent growth of only cyclin D1(-/+) cells. Furthermore, knockdown of cyclin D1 in breast carcinoma cells led to a reduction in anchorage-independent growth. Phosphorylation of the retinoblastoma (Rb) protein [a target of the cyclin D1/cyclin-dependent kinase 4/6 (cdk4/6) holoenzyme] was delayed in the cyclin D1(-/-) cells relative to cyclin D1(-/+) cells. The E7 oncogene, whose activity includes degradation of Rb and dissociation of Rb from E2F, did not confer anchorage-independent growth to the cyclin D1(-/-) cells but, in conjunction with vSrc, resulted in robust growth in soft agar. These results suggest both a cdk-dependent and cdk-independent role for cyclin D1 in modulating transformation by different oncogenes.

Multiattribute evaluation of two simple tests for the detection of Cryptosporidium parvum in calf faeces.

There is a need for simple and inexpensive diagnostic and screening tests for the detection of Cryptosporidium parvum infection in calves. A sucrose wet mount test and a lateral immunochromatography test were evaluated for epidemiological sensitivity and specificity, cost per test, simplicity, test time and ease of batching. Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) of the Cryptosporidium oocyst wall protein (COWP) gene locus, with gel electrophoresis, was used as a gold standard. Cohen's kappa statistic of agreement (kappa) between the Ontario Veterinary College (OVC) sucrose wet mount test and COWP PCR-RFLP was 0.82, and the sensitivity and specificity of the OVC sucrose wet mount test were 88.6% and 93.8%, respectively. The sensitivity and specificity of the lateral immunochromatography test were 78.3% and 93.3%, respectively, and agreement between this test and PCR-RFLP was good (kappa=0.73). There was substantial agreement between the OVC sucrose wet mount test and the lateral immunochromatography test (kappa=0.84). Both tests were inexpensive and easy to use; however, the lateral immunochromatography test was faster and simpler to perform than the sucrose wet mount test, and was generally more user-friendly. These tests provide practitioners and researchers with cheap, quick and accurate methods of detecting C. parvum infection in young calves.