DDAVP enhances platelet adherence and platelet aggregate growth on human artery subendothelium

The effect of intravenous 1-deamino (8-D-arginine)vasopressin (DDAVP) administration on platelet interaction with human artery subendothelium was investigated with flowing blood from five normal individuals and 12 patients with von Willebrand's disease (vWD). Three of the patients were diagnosed as vWD subtype I, four as subtype IIa, and five as subtype IIb. DDAVP administration to normals enhanced platelet adherence, in parallel with increasing plasma levels of factor VIII- related antigen ( FVIIIR :Ag) and ristocetin cofactor activity ( FVIIIR :RCF). Platelet aggregate formation was transiently increased within 90 minutes. Platelet adherence in patient blood before DDAVP infusion was subnormal. In patients with subtype I, administration of DDAVP normalized the bleeding time, enhanced the platelet adherence, and transiently improved the platelet aggregate formation. The platelet adherence was more corrected than would have been expected on the basis of the FVIIIR :Ag and FVIIIR :RCF levels. In patients with subtype IIa, infusion of DDAVP increased the FVIIIR :Ag levels approximately threefold, without affecting the FVIIIR :RCF levels, and in only two of four patients was a transiently enhanced platelet adherence with a corresponding shortening of the bleeding time observed. In patients with subtype IIb, administration of DDAVP increased the FVIIIR :Ag levels about threefold and the FVIIIR :RCF levels five to tenfold, but decreased the platelet adherence significantly. The bleeding time values were not normalized. A close association between the bleeding time values and corresponding platelet adherence values before and after DDAVP infusion was observed. Normalization of the bleeding time was paralleled with normalization of platelet adherence. We conclude that DDAVP improves the primary hemostasis by causing enhanced FVIII- vWF-mediated platelet adherence. DDAVP has little or no effect on the bleeding time in patients with subtype IIa and subtype IIb, because the platelet adherence is not normalized.     

Evaluation of the biliary tract: The value of performing magnetic resonance cholangiopancreatography in conjunction with a 3‐D spoiled gradient‐echo gadolinium enhanced dynamic sequence

The 3‐D gradient‐echo (GRE) sequence allows thinner sections and better resolution of biliary obstruction. When the presence of biliary obstruction is identified using magnetic resonance cholangiopancreatography, the addition of the 3‐D GRE sequence may be helpful for diagnosing biliary obstruction. By showing the changes in the bile duct wall, within the duct lumen and around the bile duct, this technique can be helpful for distinguishing benign from malignant stricture as well as a stone from an enhancing intraluminal mass.     

Hypoxia stimulates osteopontin expression and proliferation of cultured vascular smooth muscle cells: potentiation by high glucose

We examined the effect of hypoxia on proliferation and osteopontin (OPN) expression in cultured rat aortic vascular smooth muscle (VSM) cells. In addition, we determined whether hypoxia-induced increases in OPN and cell proliferation are altered under hyperglycemic conditions. Quiescent cultures of VSM cells were exposed to hypoxia (3% O(2)) or normoxia (18% O(2)) in a serum-free medium, and cell proliferation as well as the expression of OPN was assessed. Cells exposed to hypoxia for 24 h exhibited a significant increase in [(3)H]thymidine incorporation followed by a significant increase in cell number at 48 h in comparison with respective normoxic controls. Exposure to hypoxia produced significant increases in OPN protein and mRNA expression at 2 h followed by a gradual decline at 6 and 12 h, with subsequent significant increases at 24 h. Neutralizing antibodies to either OPN or its receptor beta3 integrin but not neutralizing antibodies to beta5 integrin prevented the hypoxia-induced increase in [(3)H]thymidine incorporation. Inhibitors of protein kinase C (PKC) and p38 mitogen-activated protein (MAP) kinase also reduced the hypoxia-induced stimulation of proliferation and OPN synthesis. Exposure to high-glucose (HG) (25 mmol/l) medium under normoxic conditions also resulted in significant increases in OPN protein and mRNA levels as well as the proliferation of VSM cells. Under hypoxic conditions, HG further stimulated OPN synthesis and cell proliferation in an additive fashion. In conclusion, hypoxia-induced proliferation of cultured VSM cells is mediated by the stimulation of OPN synthesis involving PKC and p38 MAP kinase. In addition, hypoxia also enhances the effect of HG conditions on both OPN and proliferation of cultured VSM cells, which may have important implications in the development of diabetic atherosclerosis associated with arterial wall hypoxia.     

Retrospective validation of a surveillance system for unexplained illness and death: New Haven County, Connecticut

OBJECTIVES: This study investigated retrospective validation of a prospective surveillance system for unexplained illness and death due to possibly infectious causes. METHODS: A computerized search of hospital discharge data identified patients with potential unexplained illness and death due to possibly infectious causes. Medical records for such patients were reviewed for satisfaction of study criteria. Cases identified retrospectively were combined with prospectively identified cases to form a reference population against which sensitivity could be measured. RESULTS: Retrospective validation was 41% sensitive, whereas prospective surveillance was 73% sensitive. The annual incidence of unexplained illness and death due to possibly infectious causes during 1995 and 1996 in the study county was conservatively estimated to range from 2.7 to 6.2 per 100,000 residents aged 1 to 49 years. CONCLUSIONS: Active prospective surveillance for unexplained illness and death due to possibly infectious causes is more sensitive than retrospective surveillance conducted through a published list of indicator codes. However, retrospective surveillance can be a feasible and much less labor-intensive alternative to active prospective surveillance when the latter is not possible or desired.     

Modified grey line split with anterior lamellar repositioning for treatment of cicatricial lid entropion

To determine the success rate of surgery of modified grey line split with anterior lamellar repositioning in patients with cicatricial lid entropion and to determine the risk factors of failure of the procedure, 40 patients (84 lids) with either lid involvement caused by cicatricial lid entropion of different etiologies were enrolled in this study. All the lids were operated on using the technique of modified grey line split and anterior lamellar repositioning. The success of the procedure was assessed by restoration of anatomical and physiological functioning of the lid without any residual symptom to the patient. Patients were examined initially at weekly intervals for 1 month and subsequently followed up at 2, 3, and 12 months following surgery. Among the various causes for cicatricial lid entropion, infectious etiology (72/84 lids) was found to be the most common one. A success rate of modified grey line split with anterior lamellar repositioning was 88.09% (74/84 lids). The underlying etiology of cicatricial lid entropion was the sole predictor of failure of surgery. Those with the etiology of infection had more than 6 times the odds of surgery failure (OR: 6.73; 95% CI: 2.79-16.73) as compared to a patient without infectious etiology. The role of other factors such as the age of the patient, degree of entropion, previous entropion surgery, the lid (upper or lower) involved, irregular lid margin, and defective lid closure were statistically insignificant. The underlying etiology of cicatricial lid entropion is the only risk factor that significantly influences the outcome of surgery with this technique. Otherwise, this procedure gives good results with fewer complications in patients with cicatricial lid entropion.     

Prevalence of peripheral arterial disease by ankle-brachial index and its correlation with carotid intimal thickness and coronary risk factors in Nepalese population over the age of forty years.

Objectives: Noninvasive measures of subclinical atherosclerosis such as the ankle brachial index (ABI) and common carotid artery intima-media thickness (CCA IMT) could improve risk prediction and provide more focused primary prevention strategies. This report describes the prevalence of subclinical atherosclerotic vascular disease in a Nepalese population over the age of forty years as measured by ABI and CCA IMT and their association with established cardiovascular risk factors. Materials and methods: Ultrasonic evaluation of ABI and CCA IMT was done in 195 individuals of age 40 years and above who had presented to an outpatient department. Patients with established diagnosis of coronary artery disease or symptomatic for peripheral arterial disease were excluded from the study. Results: The prevalence of atherosclerotic disease as measured by ABI was 18.5% and there was a statistically significant correlation between ABI and CCA IMT and other established cardiovascular risk factors such as smoking, diabetes mellitus and hypertension. Conclusions: We recommend that ABI as measured by sphygmomanometer be incorporated into routine cardiovascular screening and when found to be abnormal further confirmed by Doppler assessment of ABI and CCA IMT as surrogate markers of atherosclerotic vascular disease.