No abstract

The protein leptin, a pleiotropic hormone regulates appetite and energy balance of the body and plays important roles in controlling linear growth, pubertal development, cardiovascular function, and immunity. Recent findings in the understanding of the structure, functional roles, and clinical significance of conditions with increased and decreased leptin secretion are summarized. Balance between leptin and other hormones is significantly regulated by nutritional status. This balance influences many organ systems, including the brain, liver, and skeletal muscle, to mediate the essential adaptation process. The aim of this review is to summarize the possible physiological functions of leptin and its signaling pathways during childhood and adolescence including control of food intake, energy regulation, growth and puberty, and immunity. Moreover, its secretion and possible roles in the adaptation process during different disease states (obesity, malnutrition, eating disorders, delayed puberty, congenital heart diseases and hepatic disorders) are discussed. The clinical manifestations and the successful management of patients with genetic leptin deficiency and the application of leptin therapy in other diseases including lipodystrophy, states with severe insulin resistance, and diabetes mellitus are discussed.

Balloon dilation of the pulmonary valve was performed in 54 patients with tetralogy of Fallot with severe cyanosis, high haematocrit and severe valvar pulmonary stenosis. Clinical, echocardiographic, angiographic, and haemodynamic data were analyzed before and after the procedure. After balloon dilation, the systemic oxygen saturation increased from a mean value of 66% to 85%. The mean value of the haematocrit before dilation was 55 + 13, and decreased to 47 after dilation (p < 0.002) in 2 months follow-up. Balloon dilation increased the size of the pulmonary valvar orifice from a mean value of 9 + 5 mm to 11.5 + 2 mm (p < 0.005). The mean Z score of the pulmonary valves, which was -3 + 1.3 before dilation, increased to -1.1 + 1.1 immediately after the procedure (p < 0.05). The size of the right and left pulmonary arteries increased after dilation from 9 mm to 10 mm, and from 8.7 + 2.4 mm to 9.8 + 2.3 mm, respectively (p < 0.05). The comparable mean Z scores increased from -2.8 + 1.9 SD to -1.8 + 1.4 SD, and from -2.4 + 1.9 SD to -1.5 + 1.6 SD for the right and left branches, respectively (p < 0.05). In patients with stenosis at the bifurcation of the pulmonary trunk and hypoplasia of the left artery, successful dilation of the pulmonary valve lead to an increase of flow and improvement in size of the hypoplastic segment. In conclusion, initial balloon dilation of the pulmonary valve in tetralogy of Fallot resulted in increase of the Z score for the pulmonary valve and improved antegrade pulmonary blood flow, inducing growth of the pulmonary arteries and ameliorating the anatomic and physiologic preoperative condition.

Rheumatic fever is still one of the major public health problems in Egypt and the developing countries. It is characterized by a high tendency to recur following streptococcal infections. The use of long acting penicillin for prophylaxis against strep infections was a good achievement in this field, yet, recurrences have been reported in patients following monthly prophylactic programs. Clinical experience in Alexandria have shown for a long time that giving penicillin every 2 weeks is followed by less recurrences of rheumatic fever. Recently, reports came showing that effective penicillin levels are not maintained except for 2 to 3 weeks after the injection. In the present study, we compared two regimens of prophylaxis with 190 patients in the 2-weekly regimen, and 170 patients in the 4-weekly regimen being followed up for 2 consecutive years. Two hundred and sixty nine streptococcal infections occurred during this period. Although the streptococcal infection rate was equal in both groups, the rheumatic fever recurrence rate and the RF attack rate were significantly higher in the group of patients on the 4-weekly schedule. The results of this study have shown the superiority of the 2-weekly schedule in the adequate control of RF recurrences. We suggest that this schedule should be implemented for secondary prophylaxis of rheumatic fever in Egypt and other areas with severe RF.

The clinical disappearance of the murmur of rheumatic mitral regurgitation after period of time has been documented by many researchers. However no studies have related the disappearance of the murmur with the functional or anatomical state of the mitral valve. This study was done to elucidate the mitral valve status using doppler and color coded echocardiography among those children who have lost their apical pansystolic murmur on auscultation following a documented attack of rheumatic fever. The study sample consisted of 51 patients including 31 patients in whom the murmur has disappeared (group I), and 20 patients with persistent isolated mitral regurgitation (group II). Patients of group I had significantly lower grades of murmur intensity, lower incidence of cardiomegaly, and had no heart failure in the initial attack. They were more compliant with prophylaxis and had less recurrences than patients of group II. The murmur disappeared in patients of group I from 1/2 to 14 years after the initial attack. Echocardiography revealed that such patients had a normal mitral valve apparatus, and a normal heart size and function. Only 5 patients of this group had a significant regurgitant jet demonstrated by colour doppler. We concluded that recovery of the mitral valve and return of cardiac functions to normal is possible in patients who had mitral regurgitation following rheumatic fever. Some of them may still have an inaudible mild regurgitation. Patients who have lost their murmur may be allowed to exercise freely, yet penicillin prophylaxis should not be discontinued.