Effects of tocolytic treatment with ritodrine on cardiovascular autonomic regulation

Objective To study the acute effects of tocolytic treatment with intravenous ritodrine on cardiovascular autonomic regulation.
Design Validated methods to assess cardiovascular autonomic nervous function—heart rate and blood pressure variability and vagal cardiac baroreflex sensitivity—were measured before and during ritodrine infusion.
Setting Turku University Central Hospital, Turku, Finland.
Sample Twelve pregnant women admitted to hospital for threatened preterm labour.
Methods Electrocardiogram and continuous noninvasive finger blood pressure signals were recorded in each woman, resting in a supine position. Autoregressive spectrum analysis was used to quantify short term heart rate and blood pressure variability. Vagal cardiac baroreflex sensitivity was measured as the bradycardia response to an intravenous bolus injection of phenylephrine.
Main outcome measures Vagal cardiac baroreflex sensitivity and spectrum analysis indices of short term heart rate and blood pressure variability.
Results Ritodrine significantly decreased vagal cardiac baroreflex sensitivity as well as total (0.00–0.40 Hz), low frequency (0.04–0.15 Hz) and high frequency (0.15–4.40 Hz) power bands of the heart rate variability spectrum. Ritodrine significantly increased mean heart rate and the low frequency power band of the systolic blood pressure Variability spectrum.
Conclusions In pregnant women with threatened preterm labour intravenous administration of ritodrine decreases vagal cardiac baroreflex sensitivity and vagal modulation of heart rate, and increases sympathetically mediated blood pressure variability. Decreased baroreflex sensitivity and heart rate variability are known to be associated with a poor prognosis in some patient groups, so the effects of ritodrine tocolysis may be unfavourable in women with impaired circulatory homeostasis.     

Efficacy and systemic side-effects of topical 0.5% timolol aqueous solution and 0.1% timolol hydrogel

PURPOSE: The objective of this randomized, double-blind, controlled crossover trial was to compare 0.1% timolol hydrogel formulation eyedrops with 0.5% timolol aqueous solution in terms of systemic effects, hypotensive efficacy and pharmacodynamics. METHODS: Twenty-four healthy subjects underwent careful ocular, cardiovascular and pulmonary function evaluation before and after 2 weeks of topical treatment with 0.1% timolol hydrogel or 0.5% aqueous timolol maleate. Intraocular pressure (IOP), heart rate, blood pressure, forced expiratory volume and plasma levels of timolol were measured. RESULTS: There was a statistically significant difference in the systemic absorption of timolol between these two ophthalmic timolol solutions. The peak concentration and mean area under the plasma drug concentration-time curve (AUC) were about 10-fold higher after 0.5% timolol aqueous solution. The mean peak heart rate during exercise was reduced by 19 bpm (SD 6.4 bpm) after 0.5% timolol aqueous solution and by only 4.6 bpm (SD 3.8 bpm) after 0.1% timolol hydrogel (p < 0.0001). There was no difference between the two formulations in efficacy in reducing IOP. No differences between treatments were found in respect of pulmonary function. CONCLUSIONS: The lower timolol concentration in the hydrogel vehicle and its better bioavailability resulted in reduced systemic absorption and side-effects without loss of efficacy.     

Effects of exercise training on cardiovagal and sympathetic responses to Valsalva's maneuver

PURPOSE: We tested the hypothesis that a strictly-controlled program of aerobic conditioning would increase vagal and decrease sympathetic responses to Valsalva straining. METHODS: Eleven young men performed a maximal aerobic capacity test, controlled frequency breathing (0.25 Hz), and three Valsalva maneuvers before and after 4 wk of exercise training on a cycle ergometer (30 min at > or = 70% max heart rate, 3 sessions. week-1). During controlled breathing and Valsalva straining, we recorded the electrocardiogram, noninvasive beat-by-beat arterial pressure, and peroneal nerve muscle sympathetic traffic at the popliteal fossa (pre- and postexercise sympathetic recordings were obtainable in 7 of 11 subjects). Vagal-cardiac tone was estimated from R-R interval standard deviations during controlled frequency breathing. Cardiovagal baroreflex sensitivity was derived from increases of R-R intervals as functions of increases in systolic pressures with linear regression analysis during phase IV pressure increases, and sympathetic sensitivity was derived from the quotient of total muscle sympathetic nerve activity and diastolic pressure changes during phase II pressure reductions. RESULTS: Exercise training increased VO2 max (3.38 +/- 0.10 pre-, and 3.64 +/- 0.11 L. min-1 postexercise; mean +/- SE; P = 0.04), R-R interval standard deviations (75 +/- 0.12 pre- and 94 +/- 0.14 ms postexercise; mean +/- SE; P = 0.03), and cardiovagal baroreflex sensitivity (15.0 +/- 1.1 pre-, and 25.0 ms. mm Hg-1 +/- 4.0 postexercise; mean +/- SE; P = 0.03). Exercise training did not change baseline sympathetic traffic (P = 0.31) or sympathetic nerve responses to diastolic pressure reductions (P = 0.12). CONCLUSIONS: Exercise training affects vagal and sympathetic mechanisms differently: cardiovagal baroreflex sensitivity is increased, but sympathetic responses to arterial pressure decreases are unchanged.     

Development of jaundice in Korean neonates after Cesarean section

The aim of the project was to determine the physiologic mechanisms of later- and higher-peak transitional plasma bilirubin levels in Korean infants. Blood carboxyhemoglobin, corrected for inhaled CO (COHbc), as an index of bilirubin production, and plasma total bilirubin levels in 40 healthy term Korean infants delivered by Cesarean section were measured throughout the first week of life. The COHbc levels were significantly higher in the Korean neonates than in previously studied Caucasian neonates. Moreover, COHbc levels decreased by 28% during the first 7 days of life from 0.85 ± 0.20 to 0.61 ± 0.34% (P < 0.025). This pattern parallels a 15% decrease in total hemoglobin from 181 ± 23 to 154 ± 53g/L (P < 0.05). In contrast, plasma bilirubin concentrations more than doubled from 80 ± 32 to 172 ± 48 μmol/L (4.7 ± 1.8 to 10.0 ± 2.8 mg/dL; P < 0.001), remaining unchanged between days 4 and 7. Both increased production and decreased elimination of bilirubin contribute to physiologic jaundice in Korean infants.     

Clinical features of nine males with molecularly defined deletions of the Y chromosome long arm.

Deletions of the long arm of the Y chromosome have previously been associated with azoospermia and short stature. We report the results of a detailed clinical and molecular study of nine males with partial deletions of Yq. Special emphasis was laid on congenital anomalies and dysmorphic features. Some of the patients have developmental problems or distinct facial features, namely a small chin and mouth, a high arched or cleft palate, downward slanting palpebral fissures, high nasal bridge, and dysmorphic ears. As far as we know, similar facial dysmorphism has not been previously described in association with del(Yq). These features are not, however, simply correlated to the size of the deletion. In none of these patients could evidence of aberrant Xq-Yq interchange be found.     

中国香港与西方儿童分泌性中耳炎发病率的比较

目的 调查中国香港儿童分泌性中耳炎发病率,并且进一步与西方的研究结果做比较。方法 1995-1998年,在中国香港特别行政区随机抽取小学、幼稚园(4-5岁)及幼儿园(2-3岁),对6872名2-7岁儿童进行检查,在校内接受由耳鼻咽喉科专家施行的耳镜检查及由听力学家执行的鼓室导抗测试。为了与西方研究结果作出标准化的比较,根据他们所采用的诊断标准重新计算。结果 在划分为2-3岁、4-5岁及6-7岁的研究对象中,若以耳镜临床诊断作标准,本研究分泌性中耳炎发病率为5.2％-21.6％;若以鼓室导抗图作诊断标准,发病率为7.3％-30.7％。同一组数据,发病率计算结果是会因为采用不同的鼓室导抗图诊断定义而有偏差,但无论是用哪种方法,结果都与西方同龄研究的发病率差异无显著性,而且发病率随年龄增加而下降。结论 香港2-3岁、4-5岁,及6-7岁中国儿童的分泌性中耳炎发病率与西方文献报告没有显著性差异。     

梓醇对3T3-L1脂肪细胞糖脂代谢的影响及其机制研究

目的 观察梓醇对3T3-L1脂肪细胞糖脂代谢及过氧化物酶体增长因子活化受体(PPAR-γ)蛋白表达的影响。方法 采用3T3-L1前脂肪细胞诱导分化为成熟脂肪细胞,以葡萄糖氧化酶法检测细胞的葡萄糖消耗,以油红O染色法检测梓醇、罗格列酮对前脂肪细胞分化的影响,以Western Blot法检测各组PPAR-γ蛋白的表达。结果 与空白对照组比较,梓醇组、罗格列酮组3T3-L1脂肪细胞的葡萄糖消耗量均明显增高(P < 0.01),梓醇组与罗格列酮组比较差异无统计学意义(P ＞ 0.05);罗格列酮组OD值及PPAR-γ蛋白的表达较空白对照组明显升高(P < 0.05);梓醇组OD值及PPAR-γ蛋白的表达较空白对照组明显降低(P < 0.05)。结论 梓醇在抑制PPAR-γ蛋白表达的同时能够促进葡萄糖的消耗,初步表明其具有体外调节脂肪细胞糖脂代谢的作用。     

Effect of a ''centralized intensive education system'' for clean intermittent self-catheterization in patients with voiding dysfunction who start catheterization for the first time

BACKGROUND: This study evaluated the effects of a 'centralized intensive education system' (CIES) in terms of acquiring a proper clean intermittent self-catheterization (CISC) technique by patients with voiding dysfunction. METHODS: Between March 2002 and March 2003, we prospectively and consecutively enrolled 132 hospitalized patients who learnt and started CISC for the first time due to voiding dysfunction. Patients were enrolled either of two groups (the CIES group vs the 'individualized ward education system'[IWES] group) at the time of the urologic consultation for voiding dysfunction. Out of 132 patients who enrolled in the study, 112 (45 males and 67 females, mean age 57.3 with a range of 18-81) were included in the primary analyses. The questionnaire was applied immediately before discharge. RESULTS: There were similar patient demographics and clinical parameters for the CIES (n = 62) and the IWES groups (n = 50). Of 10 items including the methodology of CISC, six items discriminated significantly in favor of the CIES (P < 0.05). The patient satisfaction with CISC education was significantly different for the two groups in terms of response to the questionnaire. The CIES group was found to be more satisfied with the education received than the IWES group (P < 0.05). Moreover, the number of trials to gain confidence to perform CISC in CIES group was significantly fewer than that of IWES group (P < 0.001). CONCLUSION: Our results demonstrate that CIES might be a superior training program for the patients with voiding dysfunction to acquire a proper CISC technique to the conventional IWES.