Effect of vitamin D deficiency and replacement on endothelial function in asymptomatic subjects

CONTEXT

Vitamin D receptors are present in many tissues. Hypovitaminosis D is considered to be a risk factor for atherosclerosis.

OBJECTIVE

This study explores the effects of vitamin D replacement on insulin sensitivity, endothelial function, inflammation, oxidative stress, and leptin in vitamin D-deficient subjects.

DESIGN, SETTING, AND PATIENTS

Twenty-three asymptomatic vitamin D-deficient subjects with 25-hydroxyvitamin D [25(OH)D] levels below 25 nmol/liter were compared with a control group that had a mean 25(OH)D level of 75 nmol/liter. The vitamin D-deficient group received 300,000 IU im monthly for 3 months. The following parameters were evaluated before and after treatment: vitamin D metabolites, leptin, endothelial function by brachial artery flow mediated dilatation (FMD), insulin sensitivity index based on oral glucose tolerance test, and lipid peroxidation as measures of thiobarbituric acid reactive substances (TBARS).

RESULTS

FMD measurements were significantly lower in 25(OH)D-deficient subjects than controls (P = 0.001) and improved after replacement therapy (P = 0.002). Posttreatment values of TBARS were significantly lower than pretreatment levels (P < 0.001). A positive correlation between FMD and 25(OH)D (r = 0.45; P = 0.001) and a negative correlation between FMD and TBARS (r = -0.28; P < 0.05) were observed. There was a significant increase in leptin levels after therapy, and the leptin levels were positively correlated with 25(OH)D levels (r = 0.45; P < 0.05).

CONCLUSIONS

This study shows that 25(OH)D deficiency is associated with endothelial dysfunction and increased lipid peroxidation. Replacement of vitamin D has favorable effects on endothelial function. Vitamin D deficiency can be seen as an independent risk factor of atherosclerosis. Hypovitaminosis D-associated endothelial dysfunction may predispose to higher rates of cardiovascular disease in the winter.

Comparative analysis of left ventricular hemodynamics and hypertrophy after aortic valve replacement with homografts or mechanical valves

BACKGROUND AND AIM OF THE STUDY

The study aim was to examine comparatively the effects of prosthetic and homograft valves in the aortic position on ventricular hemodynamics and structure.

METHODS

Hemodynamic evaluations were performed at rest and during exercise in 38 patients who had undergone aortic valve replacement (AVR) with either a homograft (n = 19) or prosthetic valve (19-23 mm; n = 19). Using echocardiographic, electrocardiographic and hematologic methods, the pressure gradient (PG); aortic valve area; diameters of left anterior wall, posterior wall (PW) and interventricular septum (IVS); ejection fraction (EF); left ventricular mass (LVM) and mass index (LVMI); electrocardiographic data of LV hypertrophy; hemoglobin; hematocrit and lactate dehydrogenase (LDH) levels were measured.

RESULTS

LVM and LVMI decreased significantly after surgery in both groups (p<0.001), but the decrease was significantly greater in the homograft group (p<0.05). The IVS and PW diameters in the homograft group decreased significantly postoperatively (p<0.05); the inter-group difference was also significant (p<0.01). In the homograft group there was a significant improvement in EF (p<0.05), and the exercise PG was significantly less. Both groups showed improved LV hypertrophy and correlation between V1S >24 mm criteria and LVMI measurements. Postoperative LDH levels in the homograft group were significantly lower than preoperative levels (p<0.05); the intergroup difference was also significant (p<0.001).

CONCLUSIONS

Our data suggest that homografts, as compared to mechanical prostheses, provide significantly better hemodynamics in the aortic position.

Intramural hydatid cyst of descending aorta complicated by false aneurysm

Hydatid disease is caused by the larval stage of Echinococcus granulosus, and the resultant fluid-filled cysts almost invariably affect the liver. Primary involvement of the aortic wall is very rare. We report a case of hydatid disease presenting as a huge cyst invading the wall of the descending aorta and complicated by a false aneurysm. Diagnostic problems and operative management are reviewed.

An epidemiological survey using the Treatment Priority Index (TPI)

The purpose of this study was to evaluate the prevalence of malocclusion and to assess the need for orthodontic treatment among 6-10 year old Turkish primary school children. The Treatment Priority Index (TPI) was used to record and measure the malocclusions. The findings were that 40.38 per cent of the observed population showed normal occlusion, 21.85 per cent had minor manifestations of malocclusion and treatment need was slight, 25.17 per cent of the subjects showed definite malocclusion, 7.54 per cent had severe malocclusion and 5.06 per cent had a very severe handicap with a mandatory treatment requirement. Orthodontic treatment need increased between 6 and 10 years of age. No statistically significant difference was found between the mean TPI values of male and female subjects.

Preparation of deoxynivalenol (vomitoxin) from field-inoculated corn

A process was developed for production of gram quantities of deoxynivalenol (DON) from corn that had been inoculated in the field with Fusarium graminearum and was estimated to contain 400-500 mg DON/kg. Steps in the purification procedure included extraction with methanol-water (1 + 1), partition from an aqueous solution into ethyl acetate by using a hydrophilic matrix, defatting, Florisil column chromatography, methylene chloride-water partition, semipreparative liquid chromatography (LC), and crystallization from ethyl acetate. The average yield of crystalline DON produced by this method (or with minor variations) was 281 mg/kg.