Search

Abstract Background Vaginal lactobacilli protect the female genital tract by producing lactic acid, bacteriocins, hydrogen peroxide or a local immune response. In bacterial vaginosis, normal lactobacilli are replaced by an anaerobic flora and this may increase susceptibility to Neisseria gonorrhoeae, a facultative anaerobe. Bacterial interference between vaginal lactobacilli and N. gonorrhoeae has not been studied in liquid medium under anaerobic conditions. By co-cultivating N. gonorrhoeae in the presence of lactobacilli we sought to identify the relative contributions of acidification and hydrogen peroxide production to any growth inhibition of N. gonorrhoeae. Methods Three strains of N. gonorrhoeae distinguishable by auxotyping were grown in the presence of high concentrations (107-108 cfu/mL) of three vaginal lactobacilli (L. crispatus, L. gasseri and L. jensenii) in an anerobic liquid medium with and without 2-(N-morpholino)-ethanesulfonic (MES) buffer. Fusobacterium nucleatum was used as an indicator of anaerobiosis. Bacterial counts were performed at 15, 20 and 25 h; at 25 h pH and hydrogen peroxide concentrations were measured. Results Growth of F. nucleatum to >108 cfu/mL at 25 h confirmed anaerobiosis. All bacteria grew in the anaerobic liquid medium and the addition of MES buffer had negligible effect on growth. L. crispatus and L. gasseri produced significant acidification and a corresponding reduction in growth of N. gonorrhoeae. This inhibition was abrogated by the addition of MES. L. jensenii produced less acidification and did not inhibit N. gonorrhoeae. Hydrogen peroxide was not detected in any experiment. Conclusions During anaerobic growth, inhibition of N. gonorrhoeae by the vaginal lactobacilli tested was primarily due to acidification and abrogated by the presence of a buffer. There was no evidence of a specific mechanism of inhibition other than acid production under these conditions and, in particular, hydrogen peroxide was not produced. The acidification potential of vaginal lactobacilli under anaerobic conditions may be their most important characteristic conferring protection against N. gonorrhoeae infection.

Acute pulmonary embolism is a substantial cause of morbidity and death. Although the American College of Chest Physicians Evidence-Based Clinical Practice Guidelines recommend surgical pulmonary embolectomy in patients with acute pulmonary embolism associated with hypotension, there are few reports of 30-day mortality rates. We performed a retrospective review of acute pulmonary embolectomy procedures performed in 96 consecutive patients who had severe, globally hypokinetic right ventricular dysfunction as determined by transthoracic echocardiography. Data on patients who were treated from January 2003 through December 2011 were derived from health system databases of the New York State Cardiac Surgery Reporting System and the Society of Thoracic Surgeons. The data represent procedures performed at 3 tertiary care facilities within a large health system operating in the New York City metropolitan area. The overall 30-day mortality rate was 4.2%. Most patients (68 [73.9%]) were discharged home or to rehabilitation facilities (23 [25%]). Hemodynamically stable patients with severe, globally hypokinetic right ventricular dysfunction had a 30-day mortality rate of 1.4%, with a postoperative mean length of stay of 9.1 days. Comparable findings for hemodynamically unstable patients were 12.5% and 13.4 days, respectively. Acute pulmonary embolectomy can be a viable procedure for patients with severe, globally hypokinetic right ventricular dysfunction, with or without hemodynamic compromise; however, caution is warranted. Our outcomes might be dependent upon institutional capability, experience, surgical ability, and careful patient selection.

Lung volume reduction surgery (LVRS) is being evaluated in the treatment of emphysema. The proposed mechanisms of improvement are increased elastic recoil of the lung and improved mechanical efficiency of the muscles of respiration. We report a unique patient with emphysema who developed a giant bulla 3 years subsequent to LVRS. The patient underwent extensive evaluation, including measurements of lung mechanics. Bullectomy was performed, but it was unsuccessful. Although the mechanisms behind the development of giant bullous disease remain speculative, heterogeneous improvement in elastic recoil following LVRS may be one of the responsible mechanisms.

Objective: To determine the nature of strokes complicating cardiac surgery., Design: A medical record review was undertaken of all patients who underwent cardiac surgery (either coronary bypass, valvular surgery, or both) between January 1990 and July 1995. Univariate and multivariate analyses were done using odds ratios (ORs) and logistic regression., Results: A total of 2211 patients underwent cardiac surgery. A total of 44 patients (2%) had postoperative strokes. They were compared with 104 surgical controls. Univariate analysis revealed that the patients with stroke were significantly older and had significantly higher rates of transient ischemic attack, congestive heart failure, and peripheral vascular disease by history. A multivariate logistic regression revealed the significant variables associated with stroke were congestive heart failure (OR, 6.8) and transient ischemic attack (OR, 1.2). Analyses of surgical variables revealed that bypass pump time of more than 120 minutes (OR, 1.40) was the only significant predictor. The majority of strokes (61%) had occurred by postoperative day 2, but 39% occurred between postoperative days 3 to 9. Hemispheric syndromes occurred in 70%, brain stem and cerebellar syndromes in 14%, and lacunar syndromes in 16%. Computed tomographic scans revealed that 29 patients had new infarcts, of which 20 (69%) were territorial, 5 (17%) were small deep, and 4 (14%) were border zone. Hemorrhagic infarction was found in 2 cases (5%). One patient (2.5%) had a cardiorespiratory arrest while undergoing computed tomography. Discharge disposition was good in 88% of patients with stroke (12% with poor outcomes) vs 97% of controls with good outcomes (3% with poor outcomes) (P = .04)., Conclusions: Strokes may be delayed following cardiac surgery perhaps because of ongoing risk of embolism or a hypercoagulable state. A surprisingly high proportion of patients have lacunar syndromes or small-deep infarcts shown on computed tomography. Early computed tomographic imaging may be useful to exclude hemorrhage if anticoagulation is considered, but is not without risk in these potentially unstable patients. Greater understanding of risk factors for stroke, timing, and subtypes may ultimately allow identification of patients at particularly high risk for perioperative stroke.

Purpose: The classic model for the effects of NaHCO3 on myocardial function predicts transient myocardial depression after an intravenous bolus of sodium bicarbonate in association with myocardial acidosis., Methods: Five anesthetized, paralyzed, and ventilated dogs underwent midline sternotomy. Myocardial global function was assessed by cardiac output, left ventricular (LV) dp/dt, LV end-systolic, and LV end-diastolic pressures. Regional myocardial function assessed by measuring the LV regional end-systolic, LV end-diastolic lengths, and LAD coronary blood flow. Coronary sinus, intramyocardial and arterial pH were measured as was free serum Ca++. Animals were made acidemia by infusion of 0.3 N HCl and then given a bolus of sodium bicarbonate. This produced transient depression followed by recovery of myocardial function., Results: During the depression phase there was no significant decrease in interstitial pH or an increase in A-VCO2 difference as predicted by the current model. However, there was a significant decrease in the serum free Ca++ that coincided with myocardial depression., Conclusion: We could not confirm the predictions of the classic model and hypothesize that myocardial depression may be caused by decreased availability of free Ca++ of decreased Ca++ flux rather than intracellular acidosis.

Background: The level of the DNA repair protein O6-methylguanine-DNA methyltransferase is an important determinant of the response of tumor cells in culture to alkylating nitrosoureas. In these cells, the abundance of messenger RNA (mRNA) is directly correlated with repair activity., Purpose: Our purpose was to compare transferase mRNA levels with the repair activity in primary human tumors., Methods: Human transferase mRNA was measured in tissue samples from brain tumors, normal lung, lung tumors, ovarian tumors, and normal human liver by use of an RNA protection assay with an antisense probe prepared from the cloned gene., Results: Normal and tumor tissue samples from the same patient had similar transferase activity levels, but transferase expression varied widely among tissue samples from different patients. Brain and lung samples, on average, had transferase mRNA levels closer to those in liver samples than their transferase activity levels. In two cases, tissue samples which were transferase deficient by the activity assays were found to lack transferase mRNA., Conclusions: Deficiencies in transferase activity are due to reduced or absent mRNA transcription or processing. In brain and lung, there may be post-transcriptional control of mRNA expression. The wide interindividual variation in transferase expression is also seen at the transcription level., Implications: These are among the first measures of transferase mRNA expression in primary human tissue. More samples should be examined to extend these observations.

The resistance of human tumor strains in culture to cell killing by alkylating nitrosoureas is correlated with their levels of the DNA repair activity O6-methylguanine-DNA methyltransferase. Strains with the Mer- phenotype have no activity and are extremely sensitive. However, the relationship between the sensitivity of human tumors in vivo and transferase levels is not known, and even the existence of Mer- human tumors in vivo has been questioned. In this study 73 human tumor and normal tissue samples from brain, lung, and ovary were assayed for transferase levels and methylpurine glycosylase activity. For each organ, transferase levels varied over 100-fold, and Mer- tumors were detected in each group. There was no correlation between transferase and glycosylase levels, indicating that the absence of transferase in some tumor samples was not an artifact due to necrosis or inactivation of enzymes in the extract.