Carotid baroreflex function ceases during vasovagal syncope

Abstract. Despite the arterial baroreflex control of heart rate and blood pressure, vasovagal syncope is a common cause of loss of consciousness in people exposed to stimuli that reduce the central blood volume, such as head-up tilt. Carotid baroreflex function was evaluated using a rapid pulse train of neck pressure and neck suction in three conscious volunteers who developed a vasovagal episode during head-up tilt. The maximal gain of the carotid-heart rate and carotid-blood pressure baroreflex function curves were identified as measures of carotid baroreceptor responsiveness. When presyncopal symptoms developed, one further baroreflex assessment was obtained before the subjects were returned to the supine position. The bradycardia and hypotension exhibited during pre-syncope and syncope reflected a leftward and downward relocation of both the cardiac and vasomotor stimulusresponse curves. In addition, during the vasovagal syncope, baroreflex control was suppressed as blood pressure remained low during neck pressure stimuli. In conclusion, arterial baroreflex function ceases during vasovagal syncope.     

Felodipine or Hydrochlorothiazide/Triamterene for Treatment of Hypertension in the Elderly: Effects on Blood Pressure, Hypertensive Heart Disease, Metabolic and Hormonal Parameters

Trenkwalder P, Plaschke M, Aulehner R, Lydtin H. Felodipine or Hydrochlorothiazide/Triamterene for Treatment of' Hypertension in the Elderly: Effects on Blood Pressure, Hypertensive Heart Disease, Metabolic and Hormonal Parameters.

The aim of the study was to compare the antihypertensive efficacy of either felodipine or the diuretic combination hydrochlorothiazide/triamterene in a group (n = 65) of elderly (≥70 years) hypertensives (office blood pressure ≥ 60/95 mmHg) with special regard to ambulatory blood pressure monitoring, hypertensive heart disease and metabolic parameters. This was a randomized, double-blind study with a treatment period of 6 months. Reduction of office and 24-hr ambulatory blood pressure was comparable with both treatment regimens; after 6 months, 18 of 29 patients in the felodipine group (62%) and 20 of 27 patients in the diuretic group (74%; p = 0.4) were controlled. While episodes of ischemic type ST-segment depression were significantly reduced in the felodipine group (from 49 to 9 episodes), there was no significant change in the diuretic group (from 24 to 21 episodes). Both regimens decreased left ventricular wall thickness, but the decline in left ventricular muscle mass index was significant only for felodipine. Felodipine did not induce any change in metabolic or hormonal parameters; the diuretic combination significantly increased serum creatinine, uric acid, plasma renin activity, and plasma prorenin. Thus, the antihypertensive efficacy of felodipine and the diuretic combination was comparable in elderly hypertensives; only felodipine, however, improved parameters of hypertensive heart diesease and showed a neutral metabolic and hormonal profile.     

Prolidase Activity in Chronic Wound and Blister Fluids

We investigated prolidase activity in samples derived from wound fluid as well as blister fluid. Prolidase activity was elevated in fluid samples collected from wounds over the levels in sera collected from patients with chronic wounds (P<0.05). Prolidase activity was also present in samples taken from blister diseases. However, prolidase activity in blister fluid was not higher than that in sera collected from patients with blister diseases. Our results indicate that prolidase may play a role in wound healing.     

Twenty-four-hour ambulatory blood pressure profiles in pediatric patients after renal transplantation

Ambulatory blood pressure monitoring was applied in 27 pediatric patients aged 6.3 – 24.3 (median 15.0) years who had been transplanted 1.5 – 8.4 years previously. Daytime values were compared with the mean of 10 concomitant casual blood pressure recordings. At the time of the study, antihypertensive drugs were given to 17 patients. Inulin clearance ranged from 18 to 116 (median 66) ml/min per 1.73 m². Ambulatory blood pressure monitoring confirmed hypertension or normotension determined by casual blood pressure measurements in 63% of patients. The physiological nocturnal dip in blood pressure was attenuated or reversed in 8 of 27 patients. It was reduced in all 3 patients with renal artery stenosis of the graft, in 3 of 4 patients with chronic rejection, in the only patient with recurrent focal segmental glomerulosclerosis, and in 1 of 6 patients with past acute rejection. The dipping was not related to inulin clearance. In conclusion, casual blood pressure measurements do not accurately reflect blood pressure in pediatric patients transplanted more than 1.5 years previously. A reduced nocturnal dip in blood pressure may indicate an underlying renovascular or renoparenchymal pathology. Ambulatory blood pressure monitoring should regularly be applied in patients with renal transplants. Received May 23, 1995; received in revised form June 18, 1996; accepted June 20, 1996     

Nasal septum lesions caused by chromium exposure among chromium electroplating workers

A chromium electroplating worker, suffering from epistaxis during work, was found to have nasal septum perforation. To determine the etiology and prevalence of nasal septum lesions, we conducted a survey of seven chromium electroplating factories and examined 79 workers. Forty workers from three aluminum electroplating factories were also enrolled as the reference group. Subjects were thoroughly examined by an otolaryngologist and each of them provided a blood and urine sample. A questionnaire interview regarding symptoms of the upper respiratory tract, past medical history, life style, and work history was also conducted. Air chromium concentrations were measured by taking area samples for 4–6 hours. Based on field observation and chromium measurements, we divided chromium electroplating into three different exposure zones: workers directly dealing with electroplating tanks (n = 31), other process workers (n = 29), and office workers and drivers (n = 19). Among the 79 chromium electroplating workers, there were 16 cases of nasal septum perforation, and 42 with either scar formation or ulceration; 10 chromium electroplating workers developed skin ulcers after performing chrome plating. No workers from aluminum electroplating factories had any nasal septum or skin abnormalities. There was a consistent trend between the degree of chromium exposure and the signs and symptoms related to the nose, throat, and skin. Immediate improvement of occupational hygiene is warranted.     

Ca antagonist ameliorates glomerular injury via suppression of glomerular hypertrophy in spontaneously hypertensive rats

Summary: A study was conducted to determine whether calcium blockers (CCB) have renoprotective effects, and if so to elucidate the mechanisms of such effects.
A total of 30 uninephrectomized (UNX) spontaneously hypertensive rats (SHR), 5 weeks of age, were divided into three groups. Group 1 was fed a diet containing 0.01% manidipine and 8% NaCl, while groups 2 and 3 were fed diets containing only 8 and 0.5% NaCl, respectively. Feeding of these diets began 7 days after UNX (experimental day 0). Bodyweight, urinary protein /24 h, urinary sodium excretion/24 h, and food intake were measured at certain time intervals.
At time of death (day 9 or 21), estimations of inulin clearance (Cin) and morphological evaluations, determination of glomerular sclerosis index (GSI), tubulointerstitial index (TII) and glomerular volume were performed.
Urinary protein was significantly higher in groups 1 and 2 than in group 3 from day 7 onward, but did not differ between the former two groups. Cin in group 2 was higher than in groups 1 and 3 on day 9, but declined to lower levels than in groups 1 and 3 by day 21. There was no difference in Cin between group 1 and group 3 on day 21. Morphometry (GSI and TII) revealed that renal lesions were more progressive in group 2 than in group 1. Glomeruli in group 2 were markedly larger than those in group 1, but no difference in glomerular volume was noted between groups 1 and 3.
Our findings suggest that CCB prevent progression of renal injury induced by accelerated hypertension in UNX SHR. the mechanisms of prevention may, at least in part, be related to suppression of glomerular hypertrophy. Inhibition of renal injury can be achieved without significant reduction of proteinuria.     

The Effect of Acute and Chronic Exercise on Thyroid Hormones in Obesity

Abstract Thyroid hormones were measured before, during and after acute exercise (60 min) or physical training (3 months) in obese women. Thyroid stimulating hormone concentration increased during acute work and decreased immediately after. No changes were seen during the two following days. An increase was seen after ten days as well as after three months of physical training. Thyroxine concentrations showed no changes. 3,5,3′-Triiodothyronine decreased slightly immediately after acute exercise, and after three months of physical training, 3,3′,5′-triiodothyronine (reverse triiodothyronine) increased slowly during and after acute exercise. A negative correlation was found between changes in fasting insulin and thyroxine and a positive correlation between changes in blood pressure and triiodothyronine after training. Lack of agreement in previous reports is probably due to methodological differences such as methods more or less susceptible to fatty acid interference, and thyroid hormones changing differently during acute work and before and after physical training. The duration of the study may also be of importance, even 3 months possibly being too short for attaining equilibrium in thyroid homeostasis.     

HO-1、HO-1 mRNA在肝硬化病人肝组织中的表达及与门静脉压力的关系

目的　观察HO CO系统在肝硬化病人肝组织中的表达及与门静脉压力的关系 ,以探讨其在肝硬化门脉高压中的作用。方法　随机选取 2 0例正常志愿者及 2 0例肝硬化患者 ,在B超引导下经皮经肝穿刺分别测定门静脉压力、抽取门静脉血和外周血并留取肝组织 ,测定血液中CO浓度 ,用免疫组化和RT PCR方法观察肝组织HO 1及其HO 1mRNA的表达。结果　肝硬化病人下腔静脉及门静脉血中CO浓度、肝组织HO 1、HO 1mRNA的表达及门静脉压力均分别显著高于正常对照组 ,正常对照组的外周血和门静脉血中CO浓度水平接近 ,无明显差异 ;但肝硬化患者的门静脉血CO浓度显著高于外周血CO浓度。结论　门脉血CO浓度、肝组织中HO 1以及HO 1mRNA表达与门静脉压力密切相关     

高渗盐水与甘露醇对颅脑手术患者脑氧代谢的影响

目的 比较3％高渗盐水（HTS）与20％甘露醇对颅脑手术患者脑氧代谢的影响。方法 择期大脑半球胶质瘤切除术患者40例，ASAⅠ级或Ⅱ级，随机分为2组（n=20）：3％HTS组（HTS组）和20％甘露醇组（M组）。采用静吸复合麻醉，呼气末异氟醚浓度为1 MAC、血液动力学稳定15．min后，分别于15 min内静脉输注3％HTS 5．35 ml／kg或20％，甘露醇1 g／kg。L3，4珠网膜下腔置管测脑脊液压力（CSFP），行右颈静脉球穿刺置管、采血，测定颈静脉球氧饱和度。分别于输注前（T0）、输注完即刻（T1）、输注完15min（T2）、30min（T3）、60min（T4）、120min（T5）监测CSFP;于T0、T3-T5时监测平均动脉压，采集颈静脉球部和桡动脉血，进行血气分析，计算动脉-静脉氧含量差（Da-jvO2）、脑氧摄取率（CERO2）。结果 与T0比较，2组CSFP在T2-T5时降低，Da-jvO2和CERO2在T4，5时降低（P〈0．05）;与M组比较，HTS组CSFP在T2时降低（P〈0．05）。结论 3％HTS与20%甘露醇均可有效地降低颅内压，改善颅脑手术患者的脑氧代谢。     

冰点下降法测定血、尿渗透压的临床应用及注意事项

本文应用溶液冰点下降法测定了178例正常血清渗透压。结果为287±13毫渗量/kg水。并对20例尿崩症病人在限水加压素试验过程中测定血清,尿渗透压。尿崩症病人尿渗透压明显低于正常人。注射加压素后,尿渗透压升到正常。在多尿症的鉴别诊断中,此法是一种简便,灵敏的手段。有重要的诊断价值。