质疑Frank—Starling心脏定律

心脏收缩释放的能量（作功）是心肌纤维长度（心室舒张末期容积，EDV）的函数，即Frank—Star一1ing（FS）心脏作功定律，被誉为心脏生理学中的“经典”理论。对此，笔者从各种不同角度进行了探讨：首先分析了Frank伸展离体心肌和Starling及其同事使用心肺制备做的实验与动物生理实际的差异，以及人们在实验中观测到的增加心肌前负荷引起收缩力增强的现象（FS现象），认为：①在正常生理条件下的动物体内，来自心脏以外的、如同心肺制备中那样人工控制心室充盈压力升高、引起EDV增加的那种血液的重力动力是不存在的。②另一方面，人为地增加前负荷，那是改变了心肌收缩时的外环境条件。③由此而激发出的FS现象，是心脏适应其外环境条件变化所作出的反应。④此种心肌收缩力增强的反应，需通过心肌细胞内部与收缩过程发生有关的心肌兴奋一收缩和化学一力学偶联等一系列生化机制（不恒定因素）方能得以实现。⑤根据他们实验中观测到的FS现象，在逻辑上不能得出前负荷这一心肌收缩时的外环境条件变化调控其作功的推论。换言之，所有的在实验中被激发出来的FS现象，都不足以成为支持FS心脏定律的证据。然后，引用国内外公认的计算心脏每搏射血作功（w）的生物物理学公式“w=P×（EDV—ESV）”，证明了w和EDV之间没有函数关系。根据心脏作功的医用物理学和生物数学的基本原理，笔者认为Frank—Starling心脏定律表达的不是心脏作功的规律。     

鱼腥草治疗上呼吸道感染的疗效观察

目的探讨鱼腥草治疗上呼吸道感染所致发热病人的疗效。方法将确诊的病例随机分为2组,治疗组和对照组各30例。治疗组给予鱼腥草、青霉素钠静滴,对照组用病毒唑、青霉素钠静滴。结果治疗组退热时间多在2d以内,对照组多在2d后。治疗组症状消失时间多在5d以内,对照组多在5d以后。差异有统计学意义。结论用鱼腥草和青霉素静滴可缩短发热时间,且症状消失快。     

The relationship between the Stiles–Crawford effect of the first kind (SCE-I) and myopia

The Stiles-Crawford effect of the first kind (SCE-I) was measured on both emmetropic and myopic subjects at six different retinal locations. The results revealed a number of significant discrepancies in receptor alignment between the groups of different refractive errors. In myopic subjects, the receptors in the nasal retina (i.e. between the fovea and the optic nerve head) were found to be aligned nasally towards the optic nerve head, whereas the receptors in the temporal retina were aligned towards the centre of the exit pupil. In emmetropic subjects, the receptors across the retina were finely tuned towards the centre of the exit pupil. The magnitude of the receptor displacement in myopic subjects was found to be directly associated with the length of the eyeball.     

Blood lymphocyte subsets in ATG-treated and allografted rats

Abstract. A single dose of rabbit antithymocyte globulin (ATG) was given as the sole immunosuppressive therapy in a model of strong MHC barrier rat heart allotransplantation. PVG/c hearts transplanted to Wistar/Kyoto (WKy) rats resulted in long-term surviving (LTS) grafts and cell-mediated lympholysis (CML) unresponsiveness in 50% of the animals. The effects of ATG treatment on the peripheral blood lymphocyte subsets were studied by flow cytometry. The absolute T-lymphocyte levels decreased to less than 5% and were normalized after 2 weeks. CD8-positive cells were normalized within 1 week, whereas CD4-and CD5-positive cells remained low. Rats with LTS grafts had low levels of all T-lymphocyte markers, especially the CD4-and CD5-positive cells. Rats rejecting their grafts showed an eightfold increase in levels of CD8-and CD5-positive lymphocytes and a twofold increase in levels of CD4-expressing lymphocytes. It is concluded that ATG treatment causes the immediate elimination of large lymphoid populations as well as long-lasting immunomodulation detectable in peripheral blood.     

Chemosensitivity of neurons in the dorsal motor nucleus of the vagus that responded to portal infusion of hypertonic saline in rats

Neural responses in the dorsal motor nucleus of the vagus (DMV) to topical administrations of sodium and portal infusions of hypertonic saline were investigated electrophysiologically by using multibarrel electrodes in anesthetized rats. Of 102 neurons that showed antidromic response to electrical stimulation of the ventral gastric vagus or the accessory celiac vagus, 51 neurons increased and 13 neurons decreased their discharge rates in response to the electrophoretic administration of sodium. The other 38 neurons did not respond to this stimulation. The portal infusion of hypertonic saline elicited neural responses of some DMV neurons whose axons are involved into either the ventral gastric or the accessory celiac vagus. Further, effects of the topical administration and the portal infusion of hypertonic saline were examined on 33 neurons. Typical response was characterized by an increase in discharge rate responding to both of the portal infusion and the topical administration. In conclusion, the DMV neurons receiving the afferent inputs from hepatoportal osmoreceptors may have an enteroceptor function detecting the change in osmotic pressure of their environment.     

Effect of cyclosporin therapy in controlling the rejection of ileal versus jejunal allografts*

Abstract. Experimental evidence suggests that jejunal allografts are rejected as rapidly as are ileal grafts, despite their lesser content of lymphoid tissue as an immunologic stimulus. However, it may be possible to postpone the rejection of jejunal grafts more readily than that of ileal grafts by means of immunosuppressive therapy with cyclosporin (CyA). To test this, we used the rat model (BN-LEW) of orthotopic small-bowel transplantation. The proximal third of the small-bowel with one-third of the mesenteric lymph nodes (n= 20), or the distal ileal third with all of the mesenteric lymph nodes (n= 22), or the entire small-bowel (n= 23) was interposed after resection of an equivalent type and length of recipient bowel. CyA (15 mg/kg) was given to all of these rats for 5 days. Three additional control groups were not given CyA. The difference in graft/recipient survival among the groups receiving CyA and among those not on CyA therapy was not statistically significant. Antidonor hemagglutinin titers, the mixed lymphocyte culture (MLC) assay, and histologic examination of the allograft failed to show a mitigated rejection reaction for the recipients of jejunal grafts. The data show that short-term treatment with CyA prolongs graft survival. Equal doses of CyA, however, did not lead to prolonged survival of jejunal grafts or alter the course of rejection in comparison with that for ileal or whole-bowel transplants.     

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.     

The importance of vaginal mucosal folds at the urethral external meatus

We report on the vaginal mucosal folds (VMF) at the urethral external meatus. Resection of the VMF reduces the dispersed micturition and other urinary symptoms. EDITORIAL COMMENT: The investigators describe the presence of a vaginal mucosal fold (VMF) just dorsal to the urethral meatus and its relationship to voiding abnormalities. VMF were found on physical examination in 8.9% of the clinic population, all of whom complained of dispersed micturition, and 79% also experienced other voiding abnormalities. The complaint of dispersed micturition was successfully treated with excision of the VMF, and the other associated symptoms were improved. This structure should be routinely looked for on physical examination, especially in patients with voiding symptoms. Only further investigation of this newly described entity at other centers around the world will determine the incidence of the anatomic finding and the prevalence of associated voiding disturbances across different populations.     

Binding units (BU) and the area under binding isotherms (AUI) new indices of effector-target conjugation

New methods for simplified quantitation of effector-target conjugation have been developed. The binding unit (BU) is defined as the number of target cells required to bind a specified percentage of effector cells. The number of binding units is determined from binding isotherms in which effector conjugate frequencies are measured by holding constant the number of effector cells and by varying the number of target cells. Alternately, a binding unit can be defined as the number of effector cells required to bind a specified percentage of target cells. In this case, BU is computed from binding isotherms in which target conjugate frequencies are measured at different values of effector cells by holding constant the number of target cells. Also, the area under the curve (AUI) of these isotherms is another index that can be used as an overall measure of the binding capacity in an effector-target system. The experimental values of BU and AUI determined from effector and target isotherms agree well with theoretical predictions based on our previously developed binding model (J. Immunol. Methods (1992) 155, 133–147). The relationship between BU and AUI, and procedures to determine these parameters are shown. The value of these indices to express effector-target conjugation quantitatively has been confirmed by determining the values of BU and AUI for the NK-K562 effector-target system.