Chick gonadogenesis following early surgical bursectomy

Left ovaries of bursectomized chick embryos were examined on the 17th day of incubation in comparison to normal and sham-operated controls, by histological and histochemical observations. The results show that in bursectomized embryos the cortex appears irregulary developed, with a significant decrease in the mean thickness and in the percentage of the secondary sex cords in the total cortical area. Furthermore, the germinal epithelium appears thicker and the subcortical medulla and the tunica albuginea more compact. The greater activity of the enzyme ⁵–3-hydroxysteroid dehydrogenase ( ⁵3HSD) found in ovaries of bursectomized embryos (histochemical method) could be related to an endocrine dismetabolism affecting the cortical development. On the basis of these results and those of other authors, some hypotheses are advanced. In particular, an action of the bursal factor on GTH receptors could be the factor responsible of the enhanced steroidogenic activity altering the hormonal environment.     

Prognostic significance of the evolution of left ventricular ejection fraction in patients with acute myocardial infarction not treated with thrombolytic therapy

Several controlled trials on the thrombolytic treatment of acutemyocardial infarction (AMI) have failed to demonstrate thatthrombolysis has a simultaneous positive effect on left ventricularfunction and survival. One explanation may be that spontaneouschanges in left ventricular function occurred during the progressionof AMI in control patients. The aim of this study was to evaluatethe spontaneous evolution of left ventricular ejection fraction(LVEF) and its prognostic influence on early (1 month) and late(1 year) mortality in patients with AMI. We studied 216 patientsadmitted to our CCU within 24 h of the onset of symptoms. LVEFwas determined by radionuclide ventriculography on admission(RNV1) and at the end of the necrotic phase (RNV2). Fourteenpatients died before RNV2. On the basis of LVEF values at RNV1,the remaining 202 patients were divided into two groups: thosewith a normal LVEF (55%), and those with an abnormal LVEF (<55%). Among patients with a normal LVEF at RNV1 (64 patients) a significantincrease (>12%) in LVEF at RNV2 was observed in 12.5%, asignificant decrease (>12%) in 12.5% and no change at allin 75%. All of these patients survived, regardless of the evolutionof LVEF. In patients with an abnormal LVEF at RNV1 (138) a significantincrease (>5%) in LVEF at RNV2 was observed in 72.5%, a significantdecrease (>5%) in 6.5% and no change at all in 21%. In patientswith a LVEF increase, both early and late mortality were significantlylower than in patients with a LVEF decrease: (early mortality4% vs 55.5%, P<0.001; late mortality 6% vs 66.6%, P<0.001)respectively. In patients without any LVEF change, mortalitywas significantly lower than in patients with a LVEF decrease:(early mortality 10% vs 55.5%, P = 0.01; late mortality 14%vs 66.6%, P=0.004) respectively. In conclusion, our data demonstrate that a significant increasein LVEF occurs in most patients with an early depression ofleft ventricular function. This behaviour is associated witha low early and late mortality in comparison with the patientswith a LVEF decrease and is independent of thrombolytic treatment.When the early measurement of LVEF is normal the prognosis isnot influenced by LVEF evolution. These findings must be keptin mind when LVEF is used as a prognostic index and as an end-pointfor the evaluation of the effects of thrombolytic therapy.     

5-Hydroxytryptamine-induced increase in left ventricular dP/dtmax does not suggest the presence of ventricular 5-HT4 receptors in the pig

Summary Although 5-hydroxytryptamine (5-HT) increases porcine atrial force and rate via 5-HT₄ receptors, its effect on left ventricular contractility is not known. Therefore, using the maximum rate of rise of left ventricular pressure (LVdP/dt_max) as an index of cardiac contractility, we have attempted to analyze the possible role of ventricular 5-HT₄ receptors in the anaesthetized pig. The full agonists at 5-HT₄ receptors, 5-HT and 5-methoxytryptamine (each 3, 10 and 30 g · kg^–1), and the -adrenoceptor agonist, isoprenaline (0.01, 0.03 and 0.1 g · kg^–1), increased heart rate, LVdP/dt_max and cardiac output. For a given degree of tachycardia, the increase in LVdP/dt_max by isoprenaline was substantially more than that observed with either 5-HT or 5-methoxytryptamine. The 5-HT₄ receptor partial agonist, renzapride (3, 10, 30, 100 and 300 g · kg^–1), also increased heart rate and LVdP/dt_max dose-dependently. When the heart was paced at 150 beats · min^–1, increases in LVdP/dt_max as well as cardiac output (except with the highest doses) by 5-HT, 5-methoxytryptamine and isoprenaline were clearly attenuated. However, the magnitude of attenuation of LVdP/dt_max responses by cardiac pacing was more marked in the case of 5-HT and 5-methoxytryptamine than with isoprenaline.The effects of renzapride (300 g · kg^–1) and tropisetron (0.3 and 3 mg · kg^–1) on increases in heart rate and LVdP/dt_max by 5-HT, 5-methoxytryptamine and isoprenaline were also studied. In the absence of atrial pacing, both renzapride and tropisetron (3 mg · kg^–1) effectively antagonized the responses to 5-HT and 5-methoxytryptamine; except for some decrease in the LVdP/dt_max response by tropisetron, the effect of isoprenaline remained essentially unchanged after the antagonists. During atrial pacing, renzapride significantly antagonized the responses to the first two doses of 5-HT, but the responses to the highest 5-HT dose and to 5-methoxytryptamine remained unaffected. Though, particularly after its higher dose, tropisetron reduced the responses to 5-HT and 5-methoxytryptamine, isoprenaline responses were also affected.The above results show that a significant part of the increase in LVdP/dt_max by 5-HT receptor agonists in the anaesthetized pig is a consequence of tachycardia elicited by these compounds via 5-HT₄ receptors. Since the increase in LVdP/dt_max, compared to tachycardia, was much less with 5-HT and 5-methoxytryptamine than with isoprenaline, and since the antagonism by renzapride and tropisetron against 5-HT and 5-methoxytryptamine during atrial pacing was relatively weaker and/or unspecific, it appears unlikely that the increase in LVdP/dt_max, during atria] pacing is mediated by ventricular 5-HT₄ receptors. This view is substantiated by our recent in vitro experiments where 5-HT (0.01 to 100 mol/l) failed to significantly increase contractions of porcine left ventricular trabeculae.Correspondence to P. R. Saxena at the above address     

Changes in patterns of left ventricular hypertrophy after aortic valve replacement for aortic stenosis and regurgitation with St. Jude Medical cardiac valves

In this study, we analyzed the extent and pattern of regression of left ventricular (LV) hypertrophy after aortic valve replacement in patients with aortic stenosis (AS) and compared the results with those of another group of patients with aortic regurgitation (AR). Seventy patients who underwent isolated aortic valve replacement were divided into 2 groups. Group 1 was comprised of 29 patients who underwent aortic valve replacement for aortic stenosis, and Group 2 of 41 patients who underwent aortic valve replacement for aortic regurgitation. A third group of 10 healthy subjects served as a healthy control group. Echocardiographic studies were done before the operation and 5 years postoperatively. At follow-up, a significant reduction in the left ventricular mass was found in both groups, but it remained significantly greater than in the healthy control group. The ratio of LV wall thickness to radius (th/r) in Group 1 decreased significantly, and at follow-up it was within the normal value. In Group 2, the th/r ratio increased, and at follow-up it was within the normal value. After aortic valve replacement, the wall thickness remained significantly greater than normal for patients with AS, and the chamber radius remained significantly greater than normal for patients with AR. For these reasons, LV hypertrophy still existed in both groups at postoperative follow-up. The actuarial survival rate was 85.3% at 16 years for Group 1 and 83.4% at 18 years for Group 2. There was no significant difference in the long-term survival rates between the 2 groups. Actuarial freedom from valve-related events was 91.9% at 16 years for Group 1 and 82% at 18 years for Group 2. There was no significant difference in the valve-related event free curves between groups. After 5 years of follow-up, th/r reached normal for both groups, indicating remodeling of the LV geometry after aortic valve replacement.     

Design and test of a vascular access device

Transarterial left ventricular assist devices (LVADs), such as the Hemopump, IABP, and PUCA-pump, are meant to be introduced into the body via the femoral or axillary artery without major surgery. For certain applications, introduction is performed directly into the aorta via an open thorax procedure. A prototype of a vascular access device has been realized that allows direct access into the aorta as an alternative for the common surgical graft anastomosis suturing technique. The device consists of a metal tube acting as a circular knife to cut a hole in the aortic wall, a screw to store the removed part of the aortic wall, and a plastic tube that is introduced through the hole and tightly connected to the aortic wall. The device could be placed without aortic clamping. The device has been tested on a slaughterhouse porcine aorta. A low-pressurized aorta appeared to be the worst case; thus, two animal experiments in the low-pressurized pulmonary artery were performed. No leakage occurred for pressures between 40 and 300 mm Hg.     

左半肝切除在肝门部胆管癌手术治疗中的应用

目的探讨左半肝切除在肝门部胆管癌治疗中的可行性。方法回顾分析12例该手术方法的应用及治疗效果。结果Ⅰ型、Ⅱ型、Ⅲ型(ⅢA、ⅢB)肝门胆管癌均可通过左半肝切除，右肝管(Ⅰ级或Ⅱ级)、空肠Roue-Y吻合来达到根治的目的。本组切除率为52％。结论左半肝切除治疗肝门部胆管癌，简化了手术程序，减小了手术的创伤，提高了手术的切除率。     

Assessment of adolescent varicocele

Varicocele is the most important male factor responsible for decreased fertility potential in married couples. From March through June 1994, 2,470 school boys aged 10–20 years were examined to establish the incidence of consecutive grades of varicocele and to develop a protocol for diagnosis and treatment of adolescents with varicocele. Grade 1 varicocele was found in 18%, grade 2 in 12%, and grade 3 in 5% of the population examined. An original protocol of ultrasonographic (US) examination (previously verified by angioscintigraphy) was introduced to assess boys with clinically diagnosed varicocele. The volume of each testis, testicular volume decrease (TVD), pampiniform vein diameter (PVD), and basal (BBF) and maximum blood flow (MBF) velocities were measured in 625 boys. In 74 cases a semen analysis was performed. The statistical analysis revealed that the presence of venous reflux and PVD correlated with the grade of varicocele. Decreases in testicular volume were highly dependent on the grade of varicocele, PVD, and BBF and MBF velocities. Analysis of the relationship between spermatic (boys over 17 years) and US findings revealed that the quality of spermatogenesis can be predicted by US examination in adolescents with varicocele. The authors recommend multiparametric US examination as a reliable, objective, and repeatable technique for establishing criteria for operative treatment in boys under 18 years of age with varicocele as well as for postoperative evaluation.     

Left Ventricular Anomalous Muscle Band and Electrocardiographic Repolarization Changes

A child with considerable electrocardiographic (ECG) repolarization abnormalities is reported in whom, after clinical and hemodynamic evaluation, only a large muscular false tendon within the left ventricular cavity was found. The genesis of the ECG changes in such cases is discussed, and the differential diagnosis from apical hypertrophic cardiomyopathy is analyzed.     

Double Outlet Right Ventricle with Intact Atrial Septum and Restrictive Ventricular Septal Defect: An Analysis of Two Cases

Two cases of double outlet right ventricle with restrictive ventricular septal defect are described. This is an uncommon presentation that causes left ventricular dysfunction because of left ventricular outflow tract obstruction. The presence of an intact atrial septum leads to severe pulmonary hypertension, which tends to aggravate the right ventricular output. In the presence of a normal left ventricle, the authors suggest the possibility of enlargement of the ventricular septal defect in order to perform a biventricular repair. The association of a supramitral valve ring in both cases, and the isolation of the left subclavian artery and an aortopulmonary fenestration in one of these cases, are also discussed. In addition we explore factors that cause restrictive ventricular septal defects as well as the mechanisms that may lead to spontaneous closure of ventricular septal defect in a double outlet right ventricle.     

肺切除并扩大性左心房部分切除治疗局部晚期肺癌疗效分析

目的探讨扩大性外科手术治疗左心房和心包内肺静脉受侵犯的局部晚期肺癌的效果。方法1998年6月至2004年11月对7例局部晚期肺癌患者施行肺切除合并左心房部分切除术,左上肺叶切除3例,同时行肺动脉和支气管袖状成形术2例,左全肺切除1例,右全肺切除2例,右中、下肺叶切除1例,全组均在非体外循环下行部分左心房切除术。结果本组无手术死亡,随访中,2例分别于术后38,26个月死亡,其余5例健在。中位生存期18.4个月。结论非体外循环下扩大性肺切除合并左心房部分切除治疗左心房及心包内肺静脉受侵犯的局部晚期肺癌,提高了患者的生活质量,延长了生存期。