Cranial distraction osteogenesis in sheep using a totally implantable hydraulic mechanism: early results.

Conventional distraction osteogenesis has been performed by using either percutaneous pins attached to a thread and screw mechanism, or a thread and screw mechanism that is implanted but still requires turning by a percutaneous instrument or device. In these situations there is always the risk of infection passing to the bone via the percutaneous connection. We have developed a totally implantable hydraulic mechanism, which is activated in much the same way as injection into the port of a tissue expander. Preliminary in vitro testing has suggested that our mechanism can produce sufficient force at appropriate rates of distraction to have a promising role in distraction osteogenesis. We examined the effect of osseous distraction on the cranial vault. Expansion of the cranial vault by distraction osteogenesis is not widespread in clinical practice, in part because of the risk of infective complications of the extra-dural space. We were, therefore, presented with an ideal opportunity both to test the new distraction device and to examine the effect of distraction osteogenesis on the cranial vault. A sheep animal model was used in a pilot study to test the plausibility and examine the physiology of cranial-vault distraction osteogenesis using a totally implantable hydraulic device. Two sheep had a device implanted in the temporal fossa so as to push the craniotomised cranial cap upwards. Distraction was performed for 13 days beginning 1 week after craniotomy. After 9 weeks of consolidation, 5.5 mm and 7.4 mm of new woven bone of normal cranial thickness were demonstrated.

Comparison of nitroglycerin lingual spray and sublingual tablet on time of onset and duration of brachial artery vasodilation in normal subjects.

This study compared the rapidity of onset, the magnitude, and the duration of action of 2 short-acting nitroglycerin preparations using high-resolution brachial ultrasound. Both sublingual tablet and lingual spray formulations caused maximal vasodilation at 3 minutes; however, the spray provided faster (at 2 minutes), greater, and more prolonged (15 minutes) vasodilation than the tablet.

Metabolic factors clustering, lipoprotein cholesterol, apolipoprotein B, lipoprotein (a) and apolipoprotein E phenotypes in premature coronary artery disease in French Canadians.

Plasma lipoprotein cholesterol abnormalities, diabetes, hypertension and smoking have all been identified as independent predictors of cardiovascular events. Clustering of multiple risk factors suggests a common metabolic link among high blood pressure, insulin resistance, plasma lipoprotein abnormalities and obesity. New guidelines for the management of dyslipidemias target patients with established coronary artery disease (CAD), and high risk patients with multiple risk factors and severe genetic lipoprotein disorders, such as familial hypercholesterolemia. To determine the prevalence of lipoprotein, apolipoprotein and metabolic disorders in premature CAD, 243 men and 61 women with premature CAD (occurring before age 60 years) and 203 age- and sex-matched controls (152 men, 61 women) were studied. After correcting for beta-blocker use (40% of men and 54% of women), hypertension and diabetes were seen more frequently in CAD patients than in controls. In men and women, cholesterol, triglycerides, low density lipoprotein (LDL) cholesterol, apolipoprotein B and lipoprotein (a) were significantly higher, and high density lipoprotein (HDL) cholesterol was lower, in CAD patients than in controls. By stratifying patients according to LDL cholesterol: HDL cholesterol ratio (5 or less, or greater than 5) and by triglyceride levels (less than 2.3 mmol/L, or 2.3 mmol/L or greater), significantly more men and women with CAD were found to have an elevated LDL cholesterol:HDL cholesterol ratio and elevated triglycerides (13.8% versus 1.9%, men and women combined, CAD versus controls, P < 0.0001). A metabolic factor index was devised, assigning a score of 1 each for presence of hypertension, lipoprotein abnormalities, diabetes or fasting blood glucose above 7.0 mmol/L, and a body mass index of 27 or greater. The prevalence of a metabolic factor index of 3 or more was 29.2% in CAD men versus 6.7% in controls (P < 0.0001) and 38.3% in CAD women versus 11.7% in controls (P < 0.01). Familial hypercholesterolemia was seen in fewer than 5% of patients with premature CAD and type III dyslipoproteinemia in one of 343 CAD patients. The distribution of apolipoprotein E phenotypes was the same in CAD patients and controls. Multivariate analysis revealed that in men, HDL cholesterol, lipoprotein (a) levels and smoking were the best predictors of risk. In men, plasma levels of LDL cholesterol, triglycerides or body mass index did not enter the model at the P < 0.05 level. In women, low HDL cholesterol, lipoprotein (a), the presence of diabetes, smoking and apolipoprotein B levels were all predictors of risk (P < 0.05). However, the clustering of risk factors may be the best predictor of risk. In this selected population, HDL and lipoprotein (a) are the best metabolic markers of premature CAD; metabolic factor clustering is common in patients with premature CAD.

Cardiovascular risk factors and lipoprotein profile in French Canadians with premature CAD: impact of the National Cholesterol Education Program II.

BACKGROUND: Coronary artery disease (CAD) is the major cause of death in Canadian adults. Regional differences in the prevalence of CAD in Canada are due, in part, to differences in cardiovascular risk factor distribution. Two hundred and forty-nine patients of predominantly French Canadian descent (greater than 90%), aged less than 60 years (202 men and 47 women) with angiographically documented CAD were examined in a cardiology secondary prevention clinic and their cardiovascular risk factors and lipoprotein cholesterol levels were determined. OBJECTIVES: To determine the prevalence of cardiovascular risk factors in a group of French Canadian subjects compared with subjects screened for the Quebec Heart Health Survey and to determine the impact of the National Cholesterol Education Program II (NCEP II) on screening and treatment of these patients. METHODS: Observation study of free-living subjects with CAD, compared with a reference group. RESULTS: Mean ages were 48.6 +/- 6.8 and 50.6 +/- 6.4 years for men and women, respectively. On average, the patients were on a diet containing approximately 31% of calories as fat, with 9.7% as saturated fats at the time of blood sampling. The mean number of risk factors was the same in men and women (3.5 +/- 1.2 for men versus 3.2 +/- 1.3 for women; P not significant) but their prevalence differed between sexes. Family history of CAD was seen in 78.5% of men versus 77.3% of women (P not significant), smoking (defined as more than 10 cigarettes per day in the year preceding the clinical evaluation) in 45.7% of men versus 41.9% of women (P not significant), a history of smoking in 75.5% of men versus 69.8% of women (P not significant) and diabetes in 14.7% of men and 25% of women (P not significant). There was less hypertension in men (31.4% versus 52.3%, P = 0.015) and fewer men had a low density lipoprotein cholesterol of 3.4 mmol/L or greater (66.8% in men versus 83% in women, P < 0.05). Men, however, had a higher prevalence of reduced high density lipoprotein cholesterol (less than 0.9 mmol/L, 57.4% in men versus 31.9% in women, P < 0.01). Only approximately 5% of premature CAD patients had familial hypercholesterolemia. Compared with a reference group from the Quebec Heart Health Survey, men and women with CAD had a higher prevalence of cardiovascular risk factors. With a cut-off point for total cholesterol of 5.2 mmol/L, 26.2% of men and 17% of women had 'normal' cholesterol levels; of these, 67.9% of men and 25% of women had high density lipoprotein less than 0.9 mmol/L. CONCLUSIONS: French Canadian men and women with CAD have a high prevalence of all cardiovascular risk factors. The patients are representative of the Montreal urban area and findings of the present study may not apply to the Quebec population with respect to the prevalence of risk factors. Under the treatment recommendations of NCEP II, 66.8% of men and 83% of women are candidates for drug therapy of dyslipoproteinemia aimed at reducing low density lipoprotein cholesterol levels. According to these data, cardiovascular risk stratification must be based on a complete lipoprotein profile or misclassification, especially in men, may occur.