Role of genetic changes in the progression of cardiovascular diseases.

This review aims to investigate the role of genetic changes in the development of cardiovascular diseases [CVD]. Oxidation of Low density Lipoprotein (LDL) and mutations in LDL receptors gene are a trigger for numerous of atherogenic events. Also, endothelial nitric oxide synthase (eNOS) plays an important role in vasodilatation of blood vessels through synthesis of nitric oxide. Three single base pair changes, 786T/C, 922A/G, and 1468T/A, have been identified in the promoter region of the eNOS gene and are associated with coronary spasm. Moreover, two distinct variable nucleotide tandem repeats (VNTRs) in introns 4 and 13 have been detected. The presence of a minimum of 38 CA repeats in intron 13 has been associated with an independent 2.2-fold increase in the risk of coronary artery disease [CAD]. Plasma glutathione peroxidase (GPx-3) maintains the vascular bioavailability of nitric oxide (NO), through depletion of reactive oxygen species. Mutation(s) or polymorphism(s) in the plasma GPx-3 gene promoter may predispose to a thrombotic disorder, and constitute a genetic risk factor for thrombotic cerebrovascular disease. Hyperhomocysteinemia is another independent risk factor for atherosclerosis and arterial thrombosis. Severe hyperhomocysteinemia could be caused by cystathionine-ß-synthase enzyme deficiency but it could be due to homozygosity of a common 677C/T point mutation in the coding region of the methylenetetrahydrofolate reductase (MTHFR) gene as a 3-fold increase in risk of CAD is associated with the MTHFR 677TT genotype. A second common variant in MTHFR 1298A/C is associated with decreased enzyme activity in vitro and in vivo, especially when occurring simultaneously with the 677 C/T polymorphism. Elevated fibrinogen, an essential component of the coagulation system, has been most consistently associated with arterial thrombotic disorders. Several polymorphisms (148C/T, 455G/A, and -854G/A) have been identified in the genes encoding the 3 pairs of fibrinogen polypeptide chains. The -455G/A, and -854G/A substitutions are the most physiologically relevant mutations. In addition the -455A allele has been associated with the progression of atheroma, and also with a 2.5-fold increase in risk of multiple lacunar infarcts in a cohort of elderly patients with stroke. It is concluded that genetic changes in the previously mentioned genes could play a significant role in the initiation and progression of CVD. This review provides useful information for both physicians and medical students whom are interested in human genetics which is related to cardiovascular diseases.

Chest trauma in children: A local experience.

BACKGROUND: Chest trauma in childhood is relatively uncommon in clinical practice, and has been the subject of few reports in the literature. This study was undertaken to examine our experience in dealing with chest trauma in children. PATIENTS AND METHODS: This was a retrospective study of 74 children who sustained chest trauma, and were referred to King Fahad Hospital in Medina over a two-year period. The age, cause of injury, severity of injury, associated extrathoracic injuries, treatment and outcome were analyzed. RESULTS: The median age of the patients was nine years. Fifty-nine of them (80%) sustained blunt trauma, and 15 (20%) were victims of penetrating injuries. Road traffic accident was the cause of chest trauma in 62% of the children, gun shot wounds were seen in five, and stab wounds in 10 children. Head injury was the most common injury associated with thoracic trauma, and was seen in 14 patients (19%), and associated intraabdominal injuries were seen in nine patients. Chest x-ray of the blunt trauma patients revealed fractured ribs in 24 children, pneumothorax in six, hemothorax in four, hemopneumothorax in three, and pulmonary contusions in 22 patients. Fifty-one percent of children were managed conservatively, 37% required tube thoracostomy, 8% were mechanically ventilated, and 4% underwent thoracotomy. CONCLUSION: The prevalence of chest trauma in children due to road traffic accidents is high in Saudi Arabia. Head injury is thought to be the most common associated extrathoracic injuries, however, most of these patients can be managed conservatively.

Prevalence of bicuspid aortic valve and mitral valve prolapse in a healthy Saudi population and the clinical implications of their association.

In this study, 103 Saudi males and 172 Saudi females were referred for medical check-up for employment purposes and/or as undergraduate students. Clinical evaluation of all participants included full cardiovascular examination, with the following investigations being performed: ECG, chest x-ray, and cross-sectional echocardiography. Bicuspid aortic valve was detected in three males and in four females, for a total percentage of 2.5%. Isolated mitral valve prolapse was detected in seven males (6.7%) and six females (3.5%). Association with mitral valve prolapse was reported in five males and seven females, with a total percentage of 4.3%. This association seems to have important etiological, medical and surgical implications.

Spontaneous bacterial peritonitis and culture negative neutrocytic ascites in patients with non-alcoholic liver cirrhosis.

Medical records of 18 patients with spontaneous bacterial peritonitis (SBP) and 19 patients with culture negative neutrocytic ascites (CNNA) were reviewed. The diagnosis of SBP was based on a positive ascitic fluid culture, a polymorphonuclear cell count (PMN) greater than 250 cells/mm3 and the absence of an intra-abdominal source of infection. The diagnosis of CNNA was based on a PMN count greater than 250 cells/mm3, a negative ascitic fluid culture, the absence of an intra-abdominal source of infection and no antibiotic treatment in the preceding 30 days. All patients in both groups had liver cirrhosis, which was mainly (62.2%) due to HBV infection. A single strain, mostly 'a Gram-negative' bacillus, was recovered from the ascitic fluid culture in the vast majority of patients (83%) with SBP. There were no significant differences between the clinical data of both groups. However, the CNNA group had a significantly better Pugh score (P value = 0.01) with a mean score of 9.42 +/- 2.24, compared to the SBP group (10.94 +/- 2.88). The only significant difference in the laboratory data was that the total bilirubin was higher in the SBP group (P < 0.01). Hospital mortality was significantly higher in the SBP patients compared to those with CNNA, 50 and 16%, respectively (P < 0.03). Recurrent ascitic fluid infection occurred in one of five patients who initially presented. In contrast no recurrence was documented in 12 patients with CNNA. Spontaneous bacterial peritonitis is a serious complication of liver cirrhosis with significantly higher mortality than CNNA. A single organism, usually enteric, is the most common causative agent.