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Background: Assessment of preload independent left ventricular function with conductance volumetry is traditionally accomplished by inflating a balloon in the inferior caval vein. Our aim was to investigate if a similar change in preload could be achieved by positive pressure ventilation with large tidal volume.Methods: Conductance volumetry generating left ventricular pressure-volume loops was used in seven pentobarbital-anesthetized pigs. Changes in preload recruitable stroke work were studied, comparing the effects of inferior vena cava occlusion (IVCO) or large tidal volume (LTV). Cardiodepression was induced by halothane anesthesia and halothane + phenylephrine, and stimulation by epinephrine infusion.Results: Although the decreasis in left ventricular end diastolic volume was slightly less with LTV (16.5 +/- 1.7 ml, mean +/- SEM) than with IVCO (22.4 +/- 1.7 ml) (P < 0.0001) the PRSW-slopes showed a high degree of correlation (r=0.80, P < 0.0001). Although peak tracheal pressures increased significantly to 27.8 +/- 0.9 mmHg during LTV, esophageal pressures (used as an indicator of pericardial pressure) were unchanged.Conclusions: Positive pressure ventilation with LTV is similar to IVCO in creating transient changes in preload, necessary for assessment of left ventricular systolic function. This observation was valid also during drug-induced cardiac depression and stimulation. The preload recruitable stroke work used for this validation was shown to be a reliable and stable method. [ABSTRACT FROM AUTHOR]

Background: Peripheral arterial blood pressure is not a reliable substitute for proximal aortic pressure. Recognition of this phenomenon is important for correct appreciation of cardiac afterload. Our aim was to evaluate the utility of the radial pulse wave to better understand ventriculo-vascular coupling during anesthesia.Methods: We observed the differences between aortic systolic pressure (AoSAP, tipmanometry) and radial systolic pressure in 15 patients, (including two women) aged 53-78 years, before coronary artery bypass surgery. We studied the induction of anesthesia with fentanyl (20 microg kg-1), moderate volume loading, and thereafter the addition of 70% nitrous oxide. The circulatory effects of mechanical ventilation were studied by doubling the tidal volumes. Pulse wave contours were assessed by calculation of radical and aortic augmentation indices (AI), which measure the second systolic pressure peak.Results: Radial systolic pressure was higher than AoSAP in the control situation (8+/-2 mmHg), and this SAP gradient increased further with fentanyl (12+/-2 mmHg). The gradient persisted throughout the study, but was partially reduced by volume loading and nitrous oxide, respectively. Radial augmentation index was the only parameter remaining in a stepwise multivariate model to explain the variance in the SAP gradient (r2=0.48). Radial augmentation index also correlated with aortic pulse pressure (r2=0.71). Mechanical ventilation had significant and similar effects on pulse wave augmentation both in the aorta and in the radial artery, and did not affect the radial to aortic SAP gradient.Conclusion: These elderly coronary patients had stiff vasculature (high aortic AI) and considerable pulse wave reflection, which was beneficially delayed by fentanyl. Changes in the radial pulse wave augmentation during mechanical ventilation were mainly a result of cyclic changes in the stroke volume, and were seldom associated with an increased systolic pressure gradient from the aorta to the radial artery. [ABSTRACT FROM AUTHOR]

HPV16 is frequently seen in invasive cervical cancer (ICC) and cervical intraepithelial neoplasia (CIN). Its E6 gene has frequent sequence variations. Although some E6 variants have been reported to have different biochemical or biological properties, they do not show geographical identity. Moreover, the definition of 'variant' has been a source of confusion because it has been based on all departures from the 'prototype' once isolated randomly from an ICC case. We amplified the HPV16 E6 gene by PCR from fresh-frozen tissue of 104 cases of ICC and CIN from Russian patients and sequenced it in positive cases. We found that 32 of 55 (58.2%) ICC cases and 18 of 49 (36.7%) CIN cases were HPV 16-positive and we could identify 3 groups of E6 variants: group A was characterized by G at nt 350 where group B had T, and group M was a heterogeneous mixture of unique E6 variants; no significant difference existed in the distribution of the different groups between ICC and CIN; the clinically malignant (as defined by FIGO stage) order between the groups was M > A > B in ICC; in the cases with a single HPV16 E6 sequence, coexisting ICC, CIN and normal epithelium in the same patient shared the E6 variant; and 4 cases of ICC had double/multiple E6 variants. The results did not show any importance of E6 variants for ICC progression in Russian women. The results also indicated that the original HPV16 variant persisted during ICC progression, and that at a low frequency, double infections and/or mutation of variants might occur. [ABSTRACT FROM AUTHOR]

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Background: Cytologic screening and follow-up can reduce the incidence of cervical cancer by detection and removal of precursor lesions. It is unknown, however, whether differences in histopathologic criteria for these precursor lesions affect the benefit of screening. These criteria may be difficult to study, but they are likely to be reflected in reported incidence of in situ cancer in small areas of Sweden.Purpose: Our purpose was to test the hypothesis that the benefit of screening can be predicted by histopathologic criteria as reflected in the reported incidence of cancer in situ.Methods: Incidence data were from the Swedish National Cancer Registry. Regression models showing the relationship between in situ and invasive cancer were formulated and estimated. Each county (total, 24) was a unit of measurement, and adjustment was made for the incidence of invasive cancer before screening.Results: During population-based screening in Sweden, the incidence of cancer in situ varied about fourfold among the 24 counties, which indicates that the criteria used to diagnose cancer in situ differed markedly. No statistically significant (P < .05) associations were found between the incidence of cancer in situ in 1965, 1970, or 1975 and the reduction in invasive cancer 5, 10, or 15 years later. According to the best-fitting model, detection of 100 extra cases of cancer in situ per 100,000 women per year in 1975 resulted in a reduction of 1.0 (95% confidence interval [CI] = -1.6-3.7) cases of invasive cancer 10 years later. The corresponding best model estimate implied a reduction of 4.6 cases (95% CI = 1.5-7.7) in a model restricted to cancer in situ in patients aged 20-50 years (when organized screening took place), invasive cancer in patients aged 30-60 years, and cancer in situ measured in 1970.Conclusions: The absent, or at most weak, association between detection of cancer in situ and subsequent reduction in invasive cancer indicates that relaxed histopathologic criteria for cancer in situ may result in extensive, unnecessary treatment of lesions that would regress spontaneously.Implication: Further studies are urgently needed to enable identification of neoplasms likely to progress to invasive, fatal disease. [ABSTRACT FROM AUTHOR]

Sotalol is the only beta-adrenergic blocking agent, that has been shown to produce delayed repolarization following acute administration. In this study an intravenous injection of 40–100 mg sotalol was given to eight patients with chronic atrial fibrillation. One patient was reverted to sinus rhythm, while the other patients were electro-converted 2 h after the injection. Three patients still in sinus rhythm 24 h later received chronic treatment for at least 12 weeks. They maintained sinus rhythm throughout the study. Identical electrophysiological investigations were performed after the acute injection and after chronic treatment. Following acute administration, sotalol produced a consistent increase in the ventricular repolarization time as measured from refractory periods and monophasic action potential duration, the change being of the magnitude of 13 to 17%. After chronic treatment the three remaining patients still showed an increase in the ventricular repolarization time, but no conclusions can be made from these few observations. However, the study confirms the existence of a class III mode of action at the cellular level following intravenous sotalol injections of40–100 mg in man. [ABSTRACT FROM PUBLISHER]

The hypothesis that the female survival advantage in many cancers is dependent on sexual maturity was tested in a population-based cohort. Complete follow-up through 1986 was achieved in virtually all 6262 individuals in Sweden who were diagnosed from 1960 through 1984 as having a malignant disease before the age of 20 years. Proportional hazards analysis revealed a 22% lower death rate overall in females than in males. The difference was unrelated to age at diagnosis for tumors arising in the nervous system and the hematopoietic system (lymphomas and leukemias) but strongly dependent on age for sarcomas and, notably, for all remaining cancers--mostly epithelial. Males and females had similar hazard rates for epithelial cancers before the age of 11 years. At ages 11 to 19 years, the rates in females were 55% to 65% lower than in males. One conceivable explanation for these findings is that female sex hormones prevent the establishment of distant metastases in certain malignant diseases. [ABSTRACT FROM AUTHOR]