Electrophysiologic effects of halothane and quinidine on canine Purkinje fibers: evidence for a synergistic interaction

The authors studied possible interactions between halothane and quinidine on the action potentials of canine Purkinje fibers superfused with Tyrode's solution. Using standard microelectrode techniques and a physiologic pacing rate (2 Hz), halothane in concentrations from 0.5% to 2% decreased the action potential duration to 50% repolarization (ADP50). Total ADP (APD100), in contrast, increased after 1% and 2% halothane. Resting membrane potential (RMP) and action potential amplitude (APamp) increased after 0.5% halothane, but returned to control with higher halothane levels. Conduction time (CT) increased at each halothane level. Pacing at faster (3 Hz) or slower (1 Hz) rates did not markedly alter the effects of halothane. Quinidine 1 X 10(-5)M decreased the phase O upstroke (Vmax) and prolonged APD100 and CT. When halothane was added, RMP and APamp decreased, Vmax decreased further, and APD100 and CT were markedly prolonged. This resulted in conduction block or inexcitability, especially at faster pacing rates (3 Hz). Synergistic interactions between halothane and quinidine were found on RMP, APamp, APD100, and CT. Effects on Vmax, APD50, and action potential duration to 90% repolarization (APD90) were additive. It is concluded that quinidine and halothane act synergistically to decrease action potential amplitude, lower RMP, and prolong conduction. Severe depression of conduction often progressed to conduction block or inexcitability when halothane, 2%, was administered during superfusion with therapeutic concentrations of quinidine.     

Does the end-to-end venous anastomosis offer a functional advantage over the end-to-side venous anastomosis in high-output arteriovenous grafts?

This study explores the hemodynamics, mechanics, and biologic response of end-to-end versus end-to-side venous anastomoses in a canine arteriovenous graft model. Femoral polytetrafluoroethylene grafts were implanted bilaterally in a paired fashion (n = 22). Detailed local hemodynamic measurements were made by use of color Doppler ultrasound imaging at 1, 4, 8, and 12 weeks after implant. Measurements included volumetric flow rate and Doppler-derived spectral window (percent window) as a measure of turbulence. Amplitude and velocity of vessel wall movement were also measured. Volume of perivascular tissue vibration quantitated kinetic energy transfer through the vessel wall. Volumetric flow rate (end to end, 1013 +/- 70 ml/min; end to side, 1015 +/- 72 ml/min), percent window (end to end, 6.6% +/- 0.6%, end to side, 5.6% +/- 0.4%) and volume of perivascular tissue vibration (end to end, 19.6 +/- 1.2 ml, end to side, 16.3 +/- 1.8 ml) were statistically equivalent in the two graft types (end to end vs end to side p greater than 0.05). Both graft types developed venous intimal-medial thickening of a similar magnitude: end to end, 0.35 +/- 0.05 mm, end to side, 0.43 +/- 0.09 mm, normal vein 0.070 +/- 0.004 mm (analysis of variance [ANOVA] p less than 0.001, p less than 0.01 for end to end or end to side vs control, end to end vs end to side p greater than 0.05 by Student-Newman-Keuls test). The best correlations with venous intimal-medial thickening were obtained from inverse percent window (r = 0.84, p less than 0.001) and volume of perivascular tissue vibration (r = 0.68, p less than 0.001). In the end to end configuration the relative amplitude of venous wall movement decreased, and the relative velocity of wall motion increased over time. We conclude that in the circumstances of this high flow arteriovenous graft model the end-to-end venous anastomosis does not significantly differ from the end-to-side venous anastomosis in terms of flow stability, turbulence, or kinetic energy transfer. The magnitude of the hyperplastic response is statistically equivalent for the two anastomotic types, but the pattern is somewhat different, possibly providing evidence for differences in stress distribution. Differences in the relative amplitude and velocity of vessel wall movement suggest that anastomotic geometry may affect the way in which kinetic energy is dissipated at the graft/vessel interface.     

Motivation and Maternal Presence during Induction of Anesthesia

Background: The authors developed a measure to determine whether maternal motivation to be present during induction (Motivation for Parental Presence during Induction of Anesthesia [MPPIA]) is related to children's anxiety during the induction process.

Methods: Mothers and children (aged 2-12 yr) undergoing outpatient, elective surgery and general anesthesia were enrolled in this study (n = 289 dyads). Items to assess motivation for parental presence during induction were selected by experts in anesthesiology, psychology, and child development; mothers completed the resulting 14-item measure as well as assessments of anxiety and coping style. Children's anxiety and compliance was assessed during induction of anesthesia. Factor analysis was performed, and maternal motivation was then examined against children's anxiety during induction of anesthesia.

Results: Factor analysis resulted in four scales with a total variance of 72.3%: MPPIA-Desire, MPPIA-Hesitancy, MPPIA-Anxiety, and MPPIA-Preparation. Analysis supported the reliability (0.89-0.94) and validity of the MPPIA. The authors found that mothers with high MPPIA-Desire and low MPPIA-Hesitancy had children with significantly higher anxiety (P < 0.0001) during induction of anesthesia, as compared with mothers with low MPPIA-Desire and MPPIA-Hesitancy. The authors also found that highly motivated mothers reported significantly higher levels of anxiety (P = 0.007).     

Differential immunoreactivity of her-2/neu oncoprotein in prostatic tissues.

To investigate HER-2/neu oncoprotein immunoreactivity, monoclonal antibody TA1 immunohistochemical examination of flash-frozen radical prostatectomy specimens was performed (n = 35). All prostatic specimens contained benign prostatic hyperplasia (BPH) and/or prostatic intraepithelial neoplasia (PIN), as well as prostatic carcinoma (CaP). HER-2/neu oncoprotein immunoreactivity in BPH tissues was not significantly different than that for the PIN basal cell layer (P = 0.10) or for the PIN luminal cells (P = 0.17). There was significantly more HER-2/neu oncoprotein immunoreactivity in BPH than in areas of CaP (P < 0.001). There was no significant difference in the amount of immunoreactivity present in PIN basal cells when compared to the PIN luminal cells (P = 0.49). Both the PIN basal cells and luminal cells stained for the HER-2/neu oncoprotein to a higher degree than cells in the CaP areas (P < 0.001 in both cases). HER-2/neu oncoprotein immunoreactivity is present at a significantly higher degree in BPH and PIN than in malignant prostatic epithelium.     

Comparison of salivary calmodulin binding proteins in Sjögren''s syndrome and healthy individuals

Background: Reduction in salivary secretion is the hallmark of Sjögren's syndrome (SS). Calmodulin (CaM) and calmodulin binding proteins (CaMBPs) play a key role in the secretory process of saliva. Recent studies have suggested that SS‐B, an autoantibody associated with SS, is a CaMBP. This finding suggests that CaMBP may contribute to the loss of saliva in SS. To better understand the role(s) of these proteins in SS, the purpose of this study was to compare salivary CaMBPs in Sjögren's patients and controls. Methods: Saliva samples were collected from 20 patients and 20 age‐, race‐, and gender‐matched controls. CaM overlay was used to identify CaMBPs in saliva of patients and controls. Results: Higher number of salivary CaMBPs was observed among patients than controls. Conclusions: The increased number of salivary CaMBPs in SS may suggest a potential role for these proteins in the pathogenesis of the disease.     

Sex differences in spatial ability in children

There is considerable evidence that sex differences in spatial ability exist in adults, with males outperforming females at every age after puberty. It is difficult, however, to find sex differences in children younger than 13. This is due in part to the lack of adequate measures of spatial ability for use with children. We report the use of spatial tests for children that are similar to those that have shown large sex differences in adults and may be measuring ability comparable to adult spatial ability. Four tests of mental rotation and spatial visualization were given to two samples of children. The first sample consisted of 81 children (39 males and 42 females) aged 9 to 12 years. The second sample consisted of 42 children (21 males and 21 females) aged 9 to 13 years. Sex differences of .4–.6 standard deviations were found on three tests in both samples. These results indicate that sex differences in spatial ability can be found in preadolescents if appropriate tests are used. Measurement of these abilities in children facilitates the investigation of possible biological and sociocultural contributors to the sex differences in spatial ability.This study was supported by National Institutes of Health Grant HD19644 and NIH Biomedical Research Support Grant S07 RR05366-24.     

A 3 year retrospective review of intrauterine insemination, using cryopreserved donor spermatozoa and cycle monitoring by urinary or serum luteinizing hormone measurements

Insemination with donor spermatozoa is an integral part of infertility treatment. For the last 3 years in our unit, intrauterine insemination with donor spermatozoa (IUID) has been used in preference to vaginal insemination. In this retrospective study, patients were offered an initial course of five single intrauterine inseminations with cryopreserved donor spermatozoa and treatment was then reviewed. A total of 389 patients received 1465 inseminations. In all, 1119 cycles were monitored using luteinizing hormone serum analyses and 346 cycles using the urine home test kits. The clinical pregnancy rate per insemination for the cycles monitored by the serum assay was 18.0% (202/1119) compared with the urine cycles (13.7%, 46/346) (P <05). The pregnancy loss rate was not significantly different (14.4%, 29/202 and 21.7%, 10/46) (serum and urine cycles respectively). The viable clinical pregnancy rate was significantly higher (P <03) for the serum cycles than for the cycles using the urinary monitoring (15.5%, 173/1119 and 10.4%, 36/346 respectively). The cycles monitored by serum assay had a significantly higher cumulative viable clinical pregnancy rate (P <0001) of 70.2% after nine inseminations compared with the urine monitored cycles of 54.8%. The majority of patients opted for the serum cycles, with a minority self-selecting the urine cycles mainly for travelling convenience. The explanation for the significant differences between the viable clinical pregnancy rates per insemination and the cumulative viable clinical pregnancy rates may be due to the sensitivity of the urine home test kit or the patients' interpretation of the result.      

脾内血管的应用解剖学研究盐酸喹那普利治疗原发性高血压的临床应用观察

目的　探讨盐酸喹那普利 (QuinaprilHydrochloride)治疗轻、中度原发性高血压的有效性和安全性。方法　全国 6家医院参加的一项多中心、随机、双盲、平行组间对照研究。结果　 113例原发性高血压病人治疗 8周后 ,总有效率达 85 84% ,统计学有显著性差异。盐酸喹那普利副反应较轻 ,对肾脏、肝脏、造血系统和心脏未见有害作用。结论　盐酸喹那普利是一种安全、疗效好、副反应小的治疗轻、中度原发性高血压的有效药物。