Assessment of the efficacy and safety of low frequency,low intensity magnetic fields in patients after knee endoprosthesis plasty. Part 2: A Clinical Study

The purpose of this clinical study was to assess low frequency, low intensity magnetic fields in the enhancement of the physical rehabilitation of patients after knee endoprosthesis surgery. The study included 62 patients who underwent total knee arthroplasty. Group A consisted of 32 patients who were physically rehabilitated. Group B consisted of 30 patients who were physically rehabilitated and treated additionally with pulsing magnetic fields (5 mT, 30 Hz, 20 min once a day, 5 days weekly). Therapy lasted 3 weeks for both groups. The rehabilitation process was evaluated using a goniometer, tensometer, goniometric pendulum test, Lysholm scale for knee function, and a visual analogue scale (VAS) questionnaire for pain and activity. The changes of measured rates were comparable in both groups. Low frequency and low intensity magnetic fields of examined parameters were not demonstrated to effectively improve the rehabilitation of patients after knee endoprosthesis surgery. Bioelectromagnetics 30:152–158, 2009. © 2008 Wiley‐Liss, Inc.     

The role fo collateral circulation in the course of coronary heart disease: 10-year clinical and angiographic follow-up

The paper presents the results of a 10-year prospective follow-up of 59 patients with coronary heart disease (CHD) concurrent with functional classes II-IV angina pectoris. Coronarography was made in all the patients whose coronary arteries and collateral blood flow were assessed. The experimental group comprised 37 patients with CHD and collateral circulatory insufficiency. The control group included 22 patients with effective collateral circulation. The experimental group showed a worse prognosis than did the control one. Myocardial infarction developed in 54 and 27% of cases, coronary heart disease mortality was 29.7 and 9% in the experimental and control groups, respectively. Effective collateral circulation is a prerequisite of successful surgical myocardial infarction.     

Prostanoids and hemodynamics in man before and during cardiopulmonary bypass

The plasma concentration of 6-keto-PGF1 alpha, the stable degradation product of prostacyclin, was similar in the radial and pulmonary arteries and in the coronary sinus before and after the induction of the anesthesia in patients undergoing coronary artery bypass surgery. After the beginning of the mechanical ventilation and anesthesia the pulmonary vascular resistance decreased although no changes were detected in the plasma levels of 6-keto-PGF1 alpha or TXB2. During the prebypass period after the sternotomy and cannulation of the large vessels the plasma level of 6-keto-PGF1 alpha was increased similarly in the radial and pulmonary arteries and even more in the coronary sinus. During the cardiopulmonary bypass the concentration of 6-keto-PGF1 alpha remained at the increased level as compared to the values before the anesthesia. This indicates that pulmonary circulation is perhaps not the main source of prostacyclin in man. The plasma level of TXB2 was increased during the prebypass period significantly only in the coronary sinus, but during the bypass also in the radial artery. The concentration ratio of 6-keto-PGF1 alpha/TXB2 was increased significantly during the prebypass period in the radial and pulmonary arteries. At the same time the pulmonary vascular resistance was, however, returned to the preanesthesia level and was thus not decreased. The vascular resistance in the systemic circulation was increased during the prebypass period. The plasma level of 6-keto-PGF1 alpha or TXB2 in the radial and pulmonary arteries did not correlate significantly with the total vascular resistance in the systemic and pulmonary circulation, respectively. The vascular resistance in the coronary circulation did not correlate significantly with TXB2 level in the radial artery or coronary sinus. There was, however, a slight positive correlation between the blood flow and the concentration of TXB2 in the coronary sinus (r = 0.76, P less than 0.01). Coronary sinus flow did, however, not correlate with the plasma level of 6-keto-PGF1 alpha in the radial artery or coronary sinus. These results indicate that the detected plasma concentrations of prostacyclin and thromboxane A2 have no significant effects on the total vascular resistance in vivo.     

Hypersensitivity of lung vessels to catecholamines in systemic hypertension.

Among patients with primary systemic hypertension pressure and arteriolar resistance in the pulmonary circulation exceed normal values and are hyper-reactive to sympathetic stimulation. A study was therefore carried out in 16 patients with uncomplicated essential hypertension and nine healthy subjects to compare the pulmonary vascular reactivity to exogenous catecholamines. In the normotensive group the dose response relation to adrenaline (microgram: dyn) was 1 = -4, 2 = -9, 3 = -9, and 4 = -10 and to noradrenaline 2 = +3, 4 = /8, 6 = +4, and 8 = +3. The relations in the hypertensive subjects were 1 = +18, 2 = +42, 3 = +59, and 4 = +77 and 2 = +39, 4 = +54, 6 = +76, and 8 = +100, respectively. Group differences were highly significant. Cardiac output (blood flow through the lungs) was raised by adrenaline and reduced by noradrenaline. In either case the driving pressure across the lungs was significantly augmented in the hypertensive patients but not in the normotensive group. Both catecholamines had a vasoconstrictor effect on the pulmonary circulation as a result of vascular over-reactivity. The opposite changes in resistance between normal and hypertensive subjects produced by adrenaline suggest that a constrictor vascular hypersensitivity occurs in the pulmonary circulation with the development of systemic high blood pressure.     

Retrograde coronary venous perfusion at low pressure

The effectiveness of localized retrograde coronary venous perfusion (RCVP) in preventing or reversing myocardial ischemia after acute ligation of a coronary artery is described. Ten domestic pigs (Group I) underwent aorto left anterior coronary vein grafting with RCVP at systemic pressure. In another set of ten pigs (Group II), the coronary vein was similarly grafted, but the proximal end of the graft was perfused with oxygenated blood by means of an external pump at reduced pressure and flow. In both groups, RCVP successfully reversed the mechanical or electrical effects produced by 2 to 5 minutes of acute arterial ligation. After several hours, Group I animals showed evidence of acute ischemia and developing infarction. Group II animals, however, were maintained for 7 hours or more with regional RCVP and no evidence of ischemia. Retrograde coronary venous perfusion at reduced pressure may be more effective than perfusion at systemic pressure in providing myocardial blood flow.     

关节腔注射联合周林频谱仪治疗对类风湿关节炎合并骨关节炎的体会

目的：探讨关节腔注射联合周林频谱仪对类风湿关节炎合并骨关节炎的疗效及护理体会。方法：将本院90例类风湿关节炎合并骨关节炎患者随机分成3组,所有患者治疗前均进行全身情况评估以及相应的常规护理措施．对照A组30例予以玻璃酸钠20mg关节腔内注射,观察A组30例使用玻璃酸钠关节腔内注射联合周林频谱仪患处照射,平均时间（19±4．5）min,照射距离以皮肤感觉温热为宜。观察B组30例在观察A组治疗方案基础上实施康复训练。三组均以15d为一疗程,疗程结束后比较各组患者临床总有效率、血液流变学变化情况以及不良反应的发生率。结果：（1）治疗后观察组临床症状总有效率较对照组比较具有统计学差异（P〈0．05）,观察组优于对照组,治疗后观察B组临床症状总有效率较观察A组比较具有统计学差异（P〈0．05）,观察B组优于观察A组;（2）治疗后三组血流速度（Vs）、平均血流速度（Vd）、舒张末期血流速度（Vm）均较治疗前升高（P〈0．05）,其中观察组升高幅度较对照组明显（P〈0．05）;观察组中观察B组优于观察A组（P〈0．05）;（3）三组不良反应发生率比较无统计学差异（P〉0．05）。结论：玻璃酸钠关节腔内注射联合周林频谱仪对类风湿关节炎合并骨关节炎疗效肯定,能快速改善患者临床症状,科学良好的康复护理干预是促进疗效的关键。     

Upstream pressure for systemic to pulmonary flow from bronchial circulation in dogs

Systemic to pulmonary flow from bronchial circulation, important in perfusing potentially ischemic regions distal to pulmonary vascular obstructions, depends on driving pressure between an upstream site in intrathoracic systemic arterial network and pulmonary vascular bed. The reported increase of pulmonary infarctions in heart failure may be due to a reduction of this driving pressure. We measured upstream element for driving pressure for systemic to pulmonary flow from bronchial circulation by raising pulmonary venous pressure (Ppv) until the systemic to pulmonary flow from bronchial circulation ceased. We assumed that this was the same as upstream pressure when there was flow. Systemic to pulmonary flow from bronchial circulation was measured in left lower lobes (LLL) of 21 anesthetized open-chest dogs from volume of blood that overflowed from pump-perfused (90-110 ml/min) pulmonary vascular circuit of LLL and was corrected by any changes of LLL fluid volume (wt). Systemic to pulmonary flow from bronchial circulation upstream pressure was linearly related to systemic arterial pressure (slope = 0.24, R = 0.845). Increasing Ppv caused a progressive reduction of systemic to pulmonary flow from bronchial circulation, which stopped when Ppv was 44 +/- 6 cmH2O and pulmonary arterial pressure was 46 +/- 7 cmH2O. A further increase in Ppv reversed systemic to pulmonary flow from bronchial circulation with blood flowing back into the dog. When net systemic to pulmonary flow from bronchial circulation by the overflow and weight change technique was zero a small bidirectional flow (3.7 +/- 2.9 ml.min-1 X 100 g dry lobe wt-1) was detected by dispersion of tagged red blood cells that had been injected.(ABSTRACT TRUNCATED AT 250 WORDS)     

Cardioprotective effects of adenosine transport inhibition during reversible ischaemia in patients with coronary artery disease

BACKGROUND: Adenosine plays a major role in protecting ischaemic myocardium and may potentiate ischaemic preconditioning. Nucleosine transport inhibition may enhance these favourable effects. DESIGN: Randomized, double blind, placebo controlled study, to investigate the haemodynamic and cardioprotective effects of nucleoside transport inhibition during ischaemia in patients with coronary artery disease. PATIENTS AND METHODS: Elective left anterior descending (LAD) coronary angioplasty was used to produce reversible ischaemia in 24 patients with stable angina and a single LAD lesion. They were randomized to receive either the nucleoside transport inhibitor draflazine or placebo. The study medication was infused between the 2nd and 3rd balloon inflation. The primary endpoint was ischaemia-induced wall motion abnormalities as measured by left septal echo amplitude, which was plotted against time to produce an area under the curve. RESULTS: No differences were observed in the systemic haemodynamics or the myocardial collateral circulation of the two groups. The ischaemia-induced regional wall motion abnormalities improved significantly after draflazine, while no difference was observed in the placebo group. This improvement was even more pronounced in patients with low caffeine levels compared with those with high caffeine levels. CONCLUSIONS: Draflazine, in the dose and route used, is associated with a significant improvement in regional myocardial function of the ischaemic area, without affecting systemic or collateral circulation, when compared with placebo. This implies that draflazine has a cardio-protective effect in ischaemic myocardium. High caffeine blood levels reduce these effects.     

补肾活血方剂与曼月乐治疗围绝经期功血的疗效及血清激素水平的改善情况比较

目的:比较补肾活血方剂与曼月乐治疗围绝经期功血的疗效及血清激素水平的改善情况。方法:选择2013年7月至2016年11月我院妇科收治的围绝经期功血患者92例为研究对象,随机分为A组和B组,每组各46例。A组口服补肾活血方剂,B组宫内放置曼月乐,两组均持续治疗3个周期。观察两组的疗效及不良反应发生率,检测两组的血清激素水平及子宫内膜厚度(ET)、血红蛋白(Hb)水平。血清激素指标包括促卵泡生成素(FSH)、黄体生成素(LH)、孕酮(P)及雌二醇(E2)。结果:两组的总有效率比较差异无统计学意义(P0.05)。治疗后,两组的血清FSH、LH、E2、P、ET和Hb水平均较治疗前显著降低(P0.01),且B血清FSH、LH、E2、P和ET水平均显著低于同期的A组(P0.01),两组的Hb水平比较差异无统计学意义(P0.05)。B组(15.22%)的不良反应发生率显著高于A组(0%)(P0.01)。结论:补肾活血方剂与曼月乐对围绝经期功血的疗效相当,但曼月乐对血清激素水平及子宫内膜增厚的改善作用更强,补肾活血方剂的安全性更高。     

Coronary vasodilation caused by intravenous cocaine in the anesthetized beagle

The aim of this study was to determine the effect of intravenous cocaine on the coronary circulation in the dog. Sixteen beagles separated into three groups were administered either cocaine (n = 8) or lidocaine (n = 4) at doses of 0.4, 2.0, and 10.0 mg/kg under conditions of constant coronary blood flow. A third group of beagles (n = 4) was administered cocaine under conditions of natural coronary blood flow. In the first group, the lowest dose of cocaine had no significant effect on coronary perfusion pressure, even though it increased mean systemic arterial pressure by 10% (p less than 0.05). The second two doses decreased coronary perfusion pressure by 13 (p less than 0.05) and 68% (p less than 0.05), respectively. In the second group, the lowest dose of lidocaine did not significantly affect coronary perfusion pressure. However, the second two doses significantly decreased coronary perfusion pressure by 22 (p less than 0.05) and 45% (p less than 0.05), respectively. Under conditions of natural coronary blood flow and coronary perfusion pressure, these same doses of cocaine increased coronary blood flow by 25, 63, and 175%, respectively. All coronary vascular responses occurred 60 s after administration of cocaine or lidocaine. We conclude that cocaine causes rapid, dose-dependent coronary vasodilation in the anesthetized beagle. The coronary vasodilation appears to be related to cocaine's known, local anesthetic properties.     

Bronchial circulation and cyclooxygenase products in acute lung injury

The role of cyclooxygenase products in the response of the bronchial circulation to acute lung injury was examined in 30 dogs. By use of an open-chest preparation the left lower lobe (LLL) pulmonary circulation was isolated, continuously weighed, and perfused in situ. The anastomotic bronchial blood flow [Qbr(s-p)] was measured as the rate of increase in the volume of the LLL-perfusion circuit. Four groups of dogs were studied. In group A, six dogs received cyclooxygenase inhibition (COI) with either indomethacin (2 mg/kg) or ibuprofen (10 mg/kg). In group B (n = 10) lung injury caused by airway instillation of glucose (15 mg) with glucose oxidase (500 micrograms/kg) (G/GO) or LLL pulmonary arterial infusion of alpha-napthyl thiourea (ANTU, 2 mg/kg). Group C (n = 10) received COI, and 30 min later injury was induced as above with either ANTU or G/GO. Group D (n = 4) received COI immediately after anesthesia; then, 30 min after completion of the surgical preparation, injury was induced with ANTU or G/GO. After COI, Qbr(s-p) decreased to 35 +/- 9% of the basal values (P less than 0.05). After administration of ANTU or G/GO, Qbr(s-p) increased irrespective of whether COI was present. 6-Ketoprostaglandin F1 alpha (6-keto-PGF1 alpha) and thromboxane B2 (TxB2) were measured by radioimmunoassay in the LLL pulmonary artery and systemic venous blood, demonstrating an increase in 6-keto-PGF1 alpha due to surgical preparation and confirming complete COI in those animals receiving COI immediately after anesthesia. These findings demonstrate that 1) the bronchial circulation is capable of a sevenfold increase in flow in response to acute lung injury.(ABSTRACT TRUNCATED AT 250 WORDS)     

The differential effects of alpha 2-adrenergic stimulation on the myocardium and coronary vessels in the isolated rat heart

The differential effects of alpha 2-adrenoceptor stimulation on myocardial contractility and coronary circulation were examined in the isolated perfused rat heart. We studied 20 Sprague-Dawley rats of similar age (26-28 weeks) and body weight (500-550 gm). Myocardial contractility (LV +dp/dt and developed pressure, LVP) and coronary flow resistance (CFR) were tested in the isolated isovolumic hearts using Langendorff preparation at a constant perfusion rate (2.5 ml/min/100 g BW) of Krebs-Henseleit bicarbonate solution. Group I (N-7) received B-HT 920 (specific alpha 2-adrenergic agonist, 0.6 to 58 micrograms/min), Group II (N-7) received B-HT 920+Yohimbine (300 nM in the perfusate). Group III (N-6) received vehicle only. Baseline LVP, LV +dP/dt and CFR were not significantly different among the 3 groups. During drug or vehicle administration, LVP and LV +dP/dt remained unchanged in all the groups. Coronary flow resistance increased in a dose-response fashion with a maximum increase of 22.7 +/- 3.6 (SE) mmHg/ml/min/g LV in Group I, and 10.5 +/- 2.0 mmHg/ml/min/g LV in Group II (p less than 0.02). We conclude that in the Sprague-Dawley rat heart, the physiologic effects of alpha 2-adrenoceptors are predominant in the coronary circulation but not in the myocardium itself possibly because of absence of post-synaptic alpha 2-adrenergic receptors in the rat myocardium.     

运动康复训练对冠心病多支病变患者运动耐量及血脂的影响

目的:探讨运动康复训练对冠心病多支病变患者活动耐量及血脂的影响。方法:选取冠心病多支病变患者,所有患者均进行不完全血运重建术,分为运动康复训练组及对照组,运动康复训练组自术后第三日起治疗组进行运动康复训练,对照组对运动量无要求。3月后,测量两组患者血脂水平及6分钟步行试验,比较两组患者步行距离、心绞痛发作次数、运动至心绞痛出现时间、6分钟内累积运动时间及血脂水平。结果:经运动康复训练治疗3月后,治疗组6分钟步行距离、运动至心绞痛出现时间及运动累积时间较对照组均明显增加,发生心绞痛次数较对照组明显减少。运动康复训练组治疗后甘油三酯、总胆固醇及低密度脂蛋白水平较治疗前明显降低,对照组仅总胆固醇有所降低,甘油三酯及低密度脂蛋白水平较治疗前无统计学差异。结论:运动康复训练可减少冠心病多支病变患者心绞痛发作次数,增加患者运动耐量并调节血脂代谢。     

Effect of hyperbaric oxygenation on central hemodynamics and oxygenating function of the lungs in open-heart surgery]

The dynamics of some oxygenating pulmonary function (OPF) indices has been studied in 33 patients with coronary cardiac disease and rheumatic lesions of cardiac valves 4-6 hours after surgery in response to a single hyperbaric oxygenation (HBO) session (1.5 ata, 45 min) in the immediate postoperative period. It is found that in the presence of slight or, on the contrary, pronounced arterial hypoxemia, no significant negative OPF changes were observed. At the same time, a temporary increase in the alveolo-arterial gradient has been found in some patients. The comparison of data on the systemic blood flow with the OPF indices permits suggesting the prevalent role of the membrane component in a PaO2 decrease in patients after using assisted circulation.     

Flow Regulation in Coronary Vascular Tree: A Model Study

Background

Coronary blood flow can always be matched to the metabolic demand of the myocardium due to the regulation of vasoactive segments. Myocardial compressive forces play an important role in determining coronary blood flow but its impact on flow regulation is still unknown. The purpose of this study was to develop a coronary specified flow regulation model, which can integrate myocardial compressive forces and other identified regulation factors, to further investigate the coronary blood flow regulation behavior.

Method

A theoretical coronary flow regulation model including the myogenic, shear-dependent and metabolic responses was developed. Myocardial compressive forces were included in the modified wall tension model. Shear-dependent response was estimated by using the experimental data from coronary circulation. Capillary density and basal oxygen consumption were specified to corresponding to those in coronary circulation. Zero flow pressure was also modeled by using a simplified capillary model.

Result

Pressure-flow relations predicted by the proposed model are consistent with previous experimental data. The predicted diameter changes in small arteries are in good agreement with experiment observations in adenosine infusion and inhibition of NO synthesis conditions. Results demonstrate that the myocardial compressive forces acting on the vessel wall would extend the auto-regulatory range by decreasing the myogenic tone at the given perfusion pressure.

Conclusions

Myocardial compressive forces had great impact on coronary auto-regulation effect. The proposed model was proved to be consistent with experiment observations and can be employed to investigate the coronary blood flow regulation effect in physiological and pathophysiological conditions.     

Assessment of atrial regional and global electromechanical function by tissue velocity echocardiography: a feasibility study on healthy individuals

Background

Myocardial contrast echocardiography and coronary flow velocity pattern with a rapid diastolic deceleration time after percutaneous coronary intervention has been reported to be useful in assessing microvascular damage in patients with acute myocardial infarction.

Aim

To evaluate myocardial contrast echocardiography with harmonic power Doppler imaging, coronary flow velocity reserve and coronary artery flow pattern in predicting functional recovery by using transthoracic echocardiography.

Methods

Thirty patients with anterior acute myocardial infarction underwent myocardial contrast echocardiography at rest and during hyperemia and were quantitatively analyzed by the peak color pixel intensity ratio of the risk area to the control area (PIR). Coronary flow pattern was measured using transthoracic echocardiography in the distal portion of left anterior descending artery within 24 hours after recanalization and we assessed deceleration time of diastolic flow velocity. Coronary flow velocity reserve was calculated two weeks after acute myocardial infarction. Left ventricular end-diastolic volumes and ejection fraction by angiography were computed.

Results

Pts were divided into 2 groups according to the deceleration time of coronary artery flow pattern (Group A; 20 pts with deceleration time ≧ 600 msec, Group B; 10 pts with deceleration time < 600 msec). In acute phase, there were no significant differences in left ventricular end-diastolic volume and ejection fraction (Left ventricular end-diastolic volume 112 ± 33 vs. 146 ± 38 ml, ejection fraction 50 ± 7 vs. 45 ± 9 %; group A vs. B). However, left ventricular end-diastolic volume in Group B was significantly larger than that in Group A (192 ± 39 vs. 114 ± 30 ml, p < 0.01), and ejection fraction in Group B was significantly lower than that in Group A (39 ± 9 vs. 52 ± 7%, p < 0.01) at 6 months. PIR and coronary flow velocity reserve of Group A were higher than Group B (PIR, at rest: 0.668 ± 0.178 vs. 0.248 ± 0.015, p < 0.0001: during hyperemia 0.725 ± 0.194 vs. 0.295 ± 0.107, p < 0.0001; coronary flow velocity reserve, 2.60 ± 0.80 vs. 1.31 ± 0.29, p = 0.0002, respectively).

Conclusion

The preserved microvasculature detecting by myocardial contrast echocardiography and coronary flow velocity reserve is related to functional recovery after acute myocardial infarction.     

Prostanoids and hemodynamics in man before and during cardiopulmonary bypass

The plasma concentration of 6-keto-PGF_1α, the stable degradation product of prostacyclin, was similar in the radial and pulmonary arteries and in the coronary sinus before and after the induction of the anesthesia in patients undergoing coronary artery bypass surgery. After the beginning of the mechanical ventilation and anesthesia the pulmonary vascular resistance decreased although no changes were detected in the plasma levels of 6-keto-PGF_1α or TXB₂. During the prebypass period after the sternotomy and cannulation of the large vessels the plasma level of 6-keto-PGF_1α was increased similarly in the radial and pulmonary arteries and even more in the coronary sinus. During the cardiopulmonary bypass the concentration of 6-keto-PGF_1α remained at the increased level as compared to the values before the anesthesia. This indicates that pulmonary circulation is perhaps not the main source of prostacyclin in man. The plasma level of TXB₂ was increased during the prebypass period significantly only in the coronary sinus, but during the bypass also in the radial artery. The concentration ratio of 6-keto-PGF_1α/TXB₂ was increased significantly during the prebypass period in the radial and pulmonary arteries. At the same time the pulmonary vascular resistance was, however, returned to the preanesthesia level and was thus not decreased. The vascular resistance in the systemic circulation was increased during the prebypass period. The plasma level of 6-keto-PGF_1α or TXB₂ in the radial and pulmonary arteries did not correlate significantly with the total vascular resistance in the systemic and pulmonary circulation, respectively. The vascular resistance in the coronary circulation did not correlate significantly with TXB₂ level in the radial artery or coronary sinus. There was, however, a slight positive correlation between the blood flow and the concentration of TXB₂ in the coronary sinus (r=0.76, P < 0.01). Coronary sinus flow did, however, not correlate with the plasma level of 6-keto-PGF_1α in the radial artery or coronary sinus. These results indicate that the detected plasma concentrations of prostacyclin and thromboxane A₂ have no significant effects on the total vascular resistance in vivo.     

N-Acetylcarnosine, a natural histidine-containing dipeptide, as a potent ophthalmic drug in treatment of human cataracts

A study was designed to document and quantify the changes in lens clarity over 6 and 24 months in 2 groups of 49 volunteers (76 eyes) with an average age of 65.3 +/- 7.0 enrolled at the time of diagnosis of senile cataracts of minimal to advanced opacification.The patients received N-acetylcarnosine, 1% sol (NAC) (26 patients, 41 eyes = Group II), placebo composition (13 patients, 21 eyes) topically (two drops, twice daily) to the conjunctival sac, or were untreated (10 patients, 14 eyes); the placebo and untreated groups were combined into the control (reference) Group I. Patients were evaluated upon entry, at 2-month (Trial 1) and 6-month (Trial 2)-intervals for best corrected visual acuity (b/c VA), by ophthalmoscopy and the original techniques of glare test (for Trial 1), stereocinematographic slit-image and retro-illumination photography with subsequent scanning of the lens. The computerized interactive digital analysis of obtained images displayed the light scattering/absorbing centers of the lens into 2-D and 3-D scales.The intra-reader reproducibility of measuring techniques for cataractous changes was good, with the overall average of correlation coefficients for the image analytical data 0.830 and the glare test readings 0.998. Compared with the baseline examination, over 6 months 41.5% of the eyes treated with NAC presented a significant improvement of the gross transmissivity degree of lenses computed from the images, 90.0% of the eyes showed a gradual improvement in b/c VA to 7-100% and 88.9% of the eyes ranged a 27-100% improvement in glare sensitivity. Topographic studies demonstrated less density and corresponding areas of opacification in posterior subcapsular and cortical morphological regions of the lens consistent with VA up to 0.3. The total study period over 24 months revealed that the beneficial effect of NAC is sustainable. No cases resulted in a worsening of VA and image analytical readings of lenses in the NAC-treated group of patients. In most of the patients drug tolerance was good. Group I of patients demonstrated the variability in the densitometric readings of the lens cloudings, negative advance in glare sensitivity over 6 months and gradual deterioration of VA and gross transmissivity of lenses over 24 months compared with the baseline and 6-month follow-up examinations. Statistical analysis revealed the significant differences over 6 and 24 months in cumulative positive changes of overall characteristics of cataracts in the NAC-treated Group II from the control Group I.The N-acetylated form of natural dipeptide L-carnosine appears to be suitable and physiologically acceptable for nonsurgical treatment for senile cataracts.     

Cardiac and coronary consequences of intracoronary platelet activating factor infusion in the domestic pig

In previous studies we have shown that platelet-activating factor (PAF) is a potent vasoactive substance with deleterious effects on coronary blood flow (CBF) and myocardial performance. The present study further investigates the effects of PAF during its sustained intracoronary infusion in the blood-perfused domestic pig (n = 16). PAF infusion (1-9 nmol/min) produced triphasic changes in CBF (n = 7): an initial brief phase of coronary dilation (14 +/- 2% above baseline), followed by severe reduction in CBF due to increase in coronary vascular resistance and a third phase of escape that was characterized by return of CBF towards baseline in spite of continuing PAF infusion. In 9 remaining pigs PAF infusion had a biphasic response: the first phase of coronary dilation rapidly turned into severe coronary constriction accompanied by severe systemic hypotension and death within a few min. PAF infusion caused a profound rise in systemic arterial and coronary venous thromboxane B2 levels, while 6-keto-PGF1 alpha and leukotriene C4-immunoreactivity levels were not changed. Indomethacin completely blocked the rise in thromboxane level during PAF infusion and abolished the constrictor effect of PAF on the coronary vessels. These data suggest that PAF might play a detrimental role on the coronary circulation and cardiac function, primarily through thromboxane A2 mediated mechanism.     

Cerebral infarction--a general-medical problem]

A knowledge of events accompanying the acute coronary failure may help understanding the acute cerebral blood flow insufficiency leading to brain infarction. Cerebral blood flow should be treated as an integral part of the systemic blood circulation. It is of importance when the disease produces lesions to the vascular wall, and the brain looses its autoregulation functions. In such a situation every extracerebral disorders--even slight--may produce extensive lesions to nervous tissue. Therefore, the treatment of the acute cerebral circulation failure requires proper functioning of all factors which may affect hemodynamics and tissue metabolism. Duration of cerebral flow disorders plays an important role in the avoidance of unfavourable complications such as brain infarction. Therefore, every physician is obliged to undertake any possible actions preventing such complications.