Electromyographic study on the sternocleidomastoid and pectoralis major muscles during respiratory activity in humans

Introduction: This study aimed to evaluate the simultaneous and maximum activities ofthe sternocleidomastoid (SCM) and pectoralis major (PM) muscles, to determine how the two types of breathing patterns (normal and forced) can affect these activities , and to verify which of these muscles could be used to establish an evaluation protocol for patients undergoing mechanical ventilation. Methods: Eleven healthy men, aged 18 to 25 years, participated in this study. The individuals remained in supine position using a respiratory belt to monitor both inspiratory and expiratory phase during shifts in the rib cage, performing three repetitions for the normal and forced respiratory movements, while keeping the breathing rhythm with a standard metronome. Electromyographic signals were captured using bipolar surface electrodes placed on the lower third of the SCM muscle and on the lower PM muscle fibers. Electromyographic signals were analyzed and the root mean square (RMS) values were calculated for a complete respiratory cycle. The EMG values were analyzed using the Bonferroni test for multiple comparisons. The homogeneity of variances was verified using the logarithmic transformation (LOG). The level of statistical significance was set at 5% (SPSS 19.0). Results: The values showed that there are signiicant differences between the EMG values of the SCM muscle during normal and forced respiration and the EMG values of the ECM and PM muscles during forced respiration. Conclusion: These results showed that the SCM muscle can be an indicator for the development of parameters to be used in the analysis of patients with respiratory failure.

Discharge in less than 30 hours after an open radical retropubic prostatectomy. A prospective study

e16156

Background: Radical Retropubic Prostatectomy (RRP) is one of the most frequent surgery performed by urologists and it has been accompanied by an improvement in surgical results such as duration of hospitalization. In this study we prospectively analyzed the viability of an early discharge from hospital after an open RRP. Methods: There were 37 consecutive RRP performed by the same surgeon from March 1st to August 30th of 2007. All of the patients were informed about the possibility of discharge from hospital in less than 30 hours after the surgery. The procedures were performed using a modified Walsh technique under combined anesthesia (general anesthesia and epidural anesthesia p analgesia with morphine) through midline incision initiated approximately 5,0 centimeters below of umbilicus. Obturatory lymphadenectomy was performed in only three patients and Exclusion criteria included patients with an Body Mass Index above 30, patients who refused to participate in the study and those with prior indication to go to the intensive care unit postoperatively. Respiratory and motor physiotherapy were initiated soon after return from the surgical block. Criteria to discharge from hospital included: good acceptance of oral diet, no need for parenteral analgesics; urinary volume > 75 ml/hour; no Foley catheter obstruction; absence of gross hematuria; urine drainage < 150 ml/24 hours. Results: 32 patients (86%) had discharged from hospital in less than 30 hours after the surgery: there were 25 patients (68%) discharged in the first 24 hours after surgery and 07 patients discharged between 24 and 30 hours after surgery. There wasn't any readmission in a period of 15 days after discharge from hospital. There were only three complications (8%)on days 07, 10 and 13 and 01 patient need to wash an obstructed Foley catheter with blood clot at postoperative day four. Conclusions: By means of simple criteria it is possible to early discharge patients after an open RRP in selected patients and it may represent a significant reduction in costs.

No significant financial relationships to disclose.

Biomarkers and obesity in surgically treated patients with prostate cancer

14536

Background: Obesity is associated with poor outcomes in prostate cancer (PC). We explored if biomarkers for proliferation and estrogen signaling relate to obesity and surgical outcomes in PC patients (pts) treated by radical prostatectomy (RP). Methods: Pts with RP at a single institution between 1993 and 2002 were reviewed (1156 pts). The analysis subset included pts with full preoperative staging and anthropometric variables (541 pts). Clinical variables examined included: age, PSA, pre-operative hemoglobin (Hgb), ethnicity, and body mass index (BMI). Surgical outcomes included: estimated blood loss (EBL), Gleason score ≥ 7 (GS >7), extra-capsular extension (ECE), positive margins (MR+), and pathologic stage (pT2 vs. pT3/T4). Biomarkers examined in a convenience subset (n = 61) included proliferation index (Ki67% in cancer cells) and ERα positivity (nuclei staining ≥5% in cancer or peri-tumoral stromal cells). Obesity was defined as BMI ≥ 30 kg/m2. A step-wise logistic regression analysis was used to determine odds ratio (OR) in relation to obesity. Results: Mean ± standard deviation for pre-operative data included: age 62.7 ± 7.5 yrs; PSA 8.4 ± 6.8 ng/dl; Hgb 13.6 ± 1.8 g/dl; and BMI 26.5 ± 3.8 kg/m2. Pt reported ethnicities included: white (432 pts), Black/African-American (69 pts), Asian/Pacific Islander (20 pts), Hispanic (16 pts). BMI correlated highly with race (Kruskal-Wallis p = 0.002) and weakly with EBL (Spearman 0.11, p = 0.009) and Hgb (Spearman 0.15, p = 0.002). No correlation was observed between obesity and Gleason score. Regression models showed obesity was independently associated with ECE (OR 2.5, 95% CI 1.2–5.3) and pT3/T4 (OR 1.9, 95% CI 1.0–3.3). Biomarker analysis showed Ki67% correlated with GS >7, (Spearman 0.25, p = 0.048), but not BMI. No ERα positivity was noted in cancer cells. Stromal ERα positivity was noted in 21/30=70% of non-obese and 15/31=48% of obese pts (Fisher’s exact test p = 0.12). Conclusion: We confirm the association between obesity, ethnicity, and poor surgical outcomes. Biomarker analysis shows that obesity has no effect on proliferation index or tumor grade. However, we observe a trend towards down-regulation of stromal ERα expression in obese patients.

No significant financial relationships to disclose.

Effective inhibition of human cytomegalovirus gene expression and replication by a ribozyme derived from the catalytic RNA subunit of RNase P from Escherichia coli

A sequence-specific ribozyme (M1GS RNA) derived from the catalytic RNA subunit of RNase P from Escherichia coli was used to target the overlapping exon 3 region of the mRNAs encoding the major transcription regulatory proteins IE1 and IE2 of human cytomegalovirus. A reduction of more than 80% in the expression levels of IE1 and IE2 and a reduction of about 150-fold in viral growth were observed in human cells that stably expressed the ribozyme. In contrast, a reduction of less than 10% in the IE1/IE2 expression and viral growth was observed in cells that either did not express the ribozyme or produced a "disabled" ribozyme that carried mutations that abolished its catalytic activity. Examination of the expression of several other viral early and late genes in the cells that expressed the M1GS ribozyme further revealed an overall reduction of at least 80% in their expression. These results are consistent with the notion that the antiviral effects in these cells are due to the fact that the ribozyme specifically inhibits the expression of IE1 and IE2 and, consequently, abolishes the expression of viral early and late genes as well as viral growth. Our study is the first, to our knowledge, to use M1GS ribozyme for inhibiting human cytomegalovirus replication and demonstrates the utility of this ribozyme for antiviral applications.

RNase P ribozymes selected in vitro to cleave a viral mRNA effectively inhibit its expression in cell culture

An in vitro selection procedure was used to select RNase P ribozyme variants that efficiently cleaved the sequence of the mRNA encoding thymidine kinase of herpes simplex virus 1. Of the 45 selected variants sequenced, 25 ribozymes carried a common mutation at nucleotides 224 and 225 of RNase P catalytic RNA from Escherichia coli (G(224)G(225) --> AA). These selected ribozymes exhibited at least 10 times higher cleavage efficiency (k(cat)/K(m)) than that derived from the wild type ribozyme. Our results suggest that the mutated A(224)A(225) are in close proximity to the substrate and enhance substrate binding of the ribozyme. When these ribozyme variants were expressed in herpes simplex virus 1-infected cells, the levels of thymidine kinase mRNA and protein were reduced by 95-99%. Our study provides the first direct evidence that RNase P ribozyme variants isolated by the selection procedure can be used for the construction of gene-targeting ribozymes that are highly effective in tissue culture. These results demonstrate the potential for using RNase P ribozymes as gene-targeting agents against any mRNA sequences, and using the selection procedure as a general approach for the engineering of RNase P ribozymes.