Myostatin expression in ventricular myocardium in a rat model of volume-overload heart failure

BACKGROUND

Mechanical stress increases myocardial myostatin expression. However, the expression of myostatin in chronic heart failure resulting from volume-overload and after treatment with beta-blockers is little known. The authors hypothesize that myostatin plays a role in the failing myocardium because of volume-overload.

MATERIALS AND METHODS

Aorto-caval shunt was created over a 4-week period in adult Sprague-Dawley rats to induce volume-overload heart failure.

RESULTS

Heart weight and body weight ratio significantly increased after shunting. The left ventricular end-diastolic dimension also significantly increased. Treatment with carvedilol in the shunt group reversed the increase in heart weight and ventricular dimension to the baseline values. Myocardial and skeletal myostatin proteins were up-regulated in the shunt group. The mRNA of myocardial myostatin also increased in the shunt group. Treatment with carvedilol reversed both protein and mRNA of myocardial myostatin to the baseline values. Treatment with N-acetylcysteine and doxazosin partially decreased myostatin mRNA and protein expression as compared with the shunt group. Carvedilol normalized the increased immunohistochemical labelling of myocardial myostatin in the shunt group.

CONCLUSION

Myocardial myostatin mRNA and protein expression were up-regulated in the rat model of volume-overload heart failure. Treatment with carvedilol is associated with a limitation of increased myostatin expression in the failing ventricular myocardium.

Long-term efficiency and stability of wetlands for treating wastewater of a lead/zinc mine and the concurrent ecosystem development

A constructed wetland system in Guangdong Province, South of China has been used for treating Pb/Zn mine discharge since 1985. The performance in the purification of the mine discharge and the concurrent ecosystem development within the system during the period of 1985-2000 has been studied. The untreated wastewater contained rather high concentrations of cadmium (Cd) (0.05 mg L(-1)), lead (Pb) (11.5 mg L(-1)), and zinc (Zn) (14.5 mg L(-1)), which greatly exceed the upper limits for industrial wastewater discharge in China. The constructed wetland system effectively removed Cd by 94.00%, Pb by 99.04%, Zn by 97.30%, and total suspended solids (TSS) by 98.95% from the mine discharge over a long period (over 16 years) leading to significant improvement in water quality; it was also found that there were no significantly annual or monthly variations in pH values, As, Cd, Hg, Pb, and Zn concentrations in water collected from the outlet of the wetland. Moreover, diversity and abundance of living organisms, including protozoan, higher plants, terrestrial animals, and birds, increased gradually. The 16-year monitoring results showed a reciprocal relationship, at a certain extent, between restoration of the wetland ecosystem, in other words, the maturity of the wetland, and the long-term efficiency and stability on purifying heavy metal-contaminated wastewater.

TIMP-2 upregulates RECK expression via dephosphorylation of paxillin tyrosine residues 31 and 118

We previously demonstrated that TIMP-2 increases the association of Crk with C3G and via subsequent activation of Rap1 enhances the expression of RECK, a membrane-anchored MMP inhibitor. In the present study, we investigate the mechanism of how the TIMP-2 signal is transduced from the alpha3beta1 integrin receptor to the Crk-C3G-Rap1 molecular complex. TIMP-2 treatment of human microvascular endothelial cells (hMVECs) increased the phosphorylation levels of Src at Tyr-527, the negative regulatory site, through enhanced association of Src with Csk. This results in the reduction of Src kinase activity and dephosphorylation of paxillin at Tyr-31/118, the target sites for Src kinase phosphorylation and also the binding sites for the downstream effector Crk. Such TIMP-2 effects accompany the disassembly of paxillin-Crk-DOCK180 molecular complex and, in turn, Rac1 inactivation. On the contrary, levels of paxillin-Crk-C3G complex formation are not reduced, rather slightly increased, which is consistent with our previous finding. Therefore, TIMP-2-mediated inhibition of Src kinase activity leads to the signaling switch from Rac1 to Rap1, thereby leading to enhanced RECK expression.

A phase II study of capecitabine plus oxaliplatin (XELOX) as first-line therapy for patients with advanced gastric cancer

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Background: The combination chemotherapy of capecitabine and cisplatin showed considerable activity and good feasibility in patients with advanced gastric cancer. Oxaliplatin has a more favorable toxicity profile compared to cisplatin. The purpose of the study is to evaluate the efficacy and toxicity of capecitabine plus oxaliplatin combination chemotherapy in previously untreated patients with advanced gastric carcinoma. Methods: Patients received intravenous oxaliplatin 130 mg/m2 over 2 hours on day 1 plus oral capecitabine 1000 mg/m2 twice daily on days 1–14, every 3 weeks. Treatment was continued until progression of disease or intolerable toxicities with a maximum of 8 cycles. All the measurability and response evaluations were reviewed and confirmed by one investigator. Results: Total 54 patients were enrolled (37 men, 17 women). The median age was 57 years (range 29–70). Among these 54 patients, fifty-two patients were evaluable. A total 311 cycles of chemotherapy were delivered. The overall response rate was 63% (95% CI, 50–76%), with complete response in 2 patient and partial responses in 32 patients. After a median follow-up of 13 months, median progression-free survival was 5.8 months (95% CI, 4.4–7.2 months); median overall survival was 11.9 months (95% CI, 8.8–15.1 months). The treatment was generally well tolerated. The most common haematological adverse event was anaemia (70% of patients). Grade 3- 4 neutropenia was observed in 4 patients and neutropenic fever was experienced in only 1 patient. Four patients had G3 thrombocytopenia, which was accompanied by G3 gastrointestinal bleeding. The most common non-haematological toxicities were neuropathy (70%), vomiting (50%), diarrohea (33%), and hand-foot syndrome (39%). But, G3–4 toxicities were rare. There was one treatment related death which was associated with grade IV neutropenic sepsis. Conclusion: XELOX was active and well tolerated as a first-line therapy for advanced gastric carcinoma.

No significant financial relationships to disclose.

Using an integrated infection control strategy during outbreak control to minimize nosocomial infection of severe acute respiratory syndrome among healthcare workers

Healthcare workers (HCWs) are at risk of acquiring severe acute respiratory syndrome (SARS) while caring for SARS patients. Personal protective equipment and negative pressure isolation rooms (NPIRs) have not been completely successful in protecting HCWs. We introduced an innovative, integrated infection control strategy involving triaging patients using barriers, zones of risk, and extensive installation of alcohol dispensers for glove-on hand rubbing. This integrated infection control approach was implemented at a SARS designated hospital (‘study hospital’) where NPIRs were not available. The number of HCWs who contracted SARS in the study hospital was compared with the number of HCWs who contracted SARS in 86 Taiwan hospitals that did not use the integrated infection control strategy. Two HCWs contracted SARS in the study hospital (0.03 cases/bed) compared with 93 HCWs in the other hospitals (0.13 cases/bed) during the same three-week period. Our strategy appeared to be effective in reducing the incidence of HCWs contracting SARS. The advantages included rapid implementation without NPIRs, flexibility to transfer patients, and re-inforcement for HCWs to comply with infection control procedures, especially handwashing. The efficacy and low cost are major advantages, especially in countries with large populations at risk and fewer economic resources.

Outcomes of febrile children presumed to be immunocompetent who present with leukopenia or neutropenia to an ambulatory setting

To determine significant medical outcomes in febrile children presenting to an ambulatory setting with neutropenia and/or leukopenia.

METHODS

Retrospective medical record review conducted on febrile patients who had a blood culture drawn, with white blood cell counts less than 5,000/mm3 and/or an absolute neutrophil count less than 1000/mm3. Ninety-one patients were identified; 5 with positive blood culture results, 13 with significant non-oncologic disease, and 3 patients with leukemia who had involvement of 2 or more cell lines.

CONCLUSIONS

In the majority of patients, clinical judgment, physical findings, and review of all cell lines of the complete blood cell count identified those with significant disease.

A histochemical and pathological study on the interrelationship between TCDD-induced AhR expression, AhR activation, and hepatotoxicity in mice

The objective of this study was to establish a correlation and interrelationship between aryl hydrocarbon receptor (AhR) and hepatotoxicity induced by TCDD. Young male ICR mice were exposed to TCDD via dermal exposure at doses of 0, 2.5, 25, and 125 ng TCDD twice weekly for 20 wk. Histopathological examination revealed a classic pattern and dose-dependent pathological changes in sinusoidal dilatations, hepatocellular swelling and degeneration, fatty infiltration, and hepatocellular necrosis. Immunochemical staining for AhR also demonstrated that the AhR-positive hepatocytes were centrilobular in location, especially with those cells cuffing the central vein. With exposures to TCDD, the number of AhR-positive cells increased with dose. Furthermore, we also demonstrated all the hepatocytes that exhibited pathological changes (e.g., fatty infiltration or necrosis) were AhR-positive. Depletion in AhR (AhR removal after activation) in many centrilobular hepatocytes, with disappearance of the AhR positive cuffing, was observed in the high TCDD exposed animals. AhR activation was also evident by the increase in CYP 1A2 expression in many centrilobular hepatocytes, especially those exposed to high doses of TCDD. Studies in the past, with experiments performed separately, could only suggest the association of AhR expression and hepatocellular toxicity. By examining the AhR expression, AhR activation (CYP 1A2 expression upregulation), and hepatocellular pathology together, it was possible to correlate these factors in the same animal and even in the same cells. Our finding provided direct evidence on the interaction and causal relationship between AhR activation and hepatic toxicity.

Use of Medicaid prescription data for syndromic surveillance--New York

INTRODUCTION

This study explored the utility and value of Medicaid prescription data for statewide syndromic surveillance.

METHODS

Daily Medicaid claims forms are transmitted to the New York State Syndromic Surveillance Project as summary counts by ZIP Code, age category, sex, and 18 medication groups. The CUSUM statistic is used to analyze the data daily at the county level with a 7-10-day moving average baseline. The system was evaluated following an outbreak of pertussis in a small institutional setting in a rural county by comparing the county's CUSUM signals for prescriptions for macrolide antibiotics with the onset of the outbreak.

RESULTS

A case of pertussis was suspected on July 21, 2004, and was reported to the New York State Department of Health on July 22. Treatment and prophylaxis were initiated on July 22. CUSUM analysis flagged a county-wide increase in macrolide antibiotics on the day of treatment/prophylaxis for the first case and contacts in the outbreak. The following week, approximately 300 contacts received prophylaxis (not all of whom were Medicaid clients), resulting in CUSUM signals during the week (July 28 and 29).

CONCLUSION

Medicaid prescription data are routinely collected and readily available for syndromic surveillance. This data source has shown potential value as an indicator of disease activity, as in this case study, in an area where a high concentration of Medicaid recipients reside. However, for the surveillance system to be considered a useful early warning system, additional study is required to determine the best methods for selecting from the automatically generated CUSUM signals those that might be important for public health.

Genetic risk identifies multiple myeloma patients who do not benefit from autologous stem cell transplantation

Genetic aberrations have emerged as major prognostic factors for patients with multiple myeloma (MM). We evaluated 126 MM patients for t(4;14) or t(11;14), 13q or p53 deletions and correlated the number of genetic aberrations with patient's clinical outcome following undergoing autologous stem cell transplantation. We demonstrate the significance of genetic-based risk classification that clearly segregate patients into low (no genetic abnormalities or only t(11;14)), intermediate (any one of the genetic abnormalities other than t(11;14)) and high-risk groups (any two or more of the genetic abnormalities other than t(11;14)). High-risk patients do not benefit from stem cell transplant and should be offered alternative therapies.

Preconsultation use of analgesics on adults presenting to the emergency department with acute appendicitis

OBJECTIVE

279 cases of appendicitis were reviewed and compared for the difference between those patients who received pain medication before consulting a surgeon and those who were not treated with analgesics.

METHODS

All patients aged 15 years and older who underwent appendicectomy for appendicitis between 1 July 2001 and 30 June 2002 were divided into group 1 (those who received preconsultaion use of analgesics) and group 2 (those who were not treated with analgesics). The following measures were compared: age, sex, symptom duration, initial vital signs, white blood cell counts, frequency of imaging studies, time to operative intervention, and operative findings. Continuous and categorical variables were analysed using t and chi(2) tests, respectively.

RESULTS

A total of 279 patients were included for analysis. Patient details (age, sex, symptom duration) of the two study groups were similar. There was no statistically significant difference between group 1 and group 2 with respect to vital signs (systolic blood pressure, pulse rate, respiratory rate, body temperature), white blood cell counts, and frequency of imaging studies (ultrasound, computed tomography). There was no significant difference in the rate of perforated appendicitis between the two study groups although a shorter median time to operative intervention has been found in the group who received analegesia.

CONCLUSION

The preconsultation use of analgesics in ED patients with a final diagnosis of appendicitis is not associated with a longer delay to operative intervention and is not associated with an increased rate of perforated appendicitis.