Cardiovascular response to mental stress in normal adolescents with hypertensive parents. Hemodynamics and mental stress in adolescents

The hemodynamic response to mental stress (mental arithmetic) was studied in adolscents with varying risk factors for essential hypertension (EH), One group (genetic) consisted of normotensive well adolescents who had at least one parentnt with EH. Another group (labile) consisted of adolescents with labile hypertension each of whom also had at least one pare with EH. The control population consisted of normotensive adolescents with a negative family history of EH. Subjects with labile hypertension demonstrated a sustained increase in systolic and diastolic pressure and heart rate during stress. This response was significantly different than the control population (P less than THE CONTROL POPULATION (P LESS THAN 0.001). The stress response of the normotensive genetic population was qualitatively similar to the group with labile hypertension and significantly different than the controls in diastolic pressure and heart rate (p less than 0.001, less than 0.02). Post-stress plasma catecholamines were higher in the labile hypertensive and genetic groups than in the control group. These findings demonstrate increased central nervous system mediated adrenergic activity and cardiovascular response in labile hypertension and also in some normotensive subjects with a genetic risk for hypertension.     

Blood pressure increase with impaired glucose tolerance in young adult american blacks

Hypertension and non-insulin-dependent diabetes mellitus are more prevalent in blacks than whites. The convergence of these 2 disorders augments the expression and severity of cardiovascular disease. The purpose of this study was to determine whether alterations in glucose metabolism are related to an increase in blood pressure (BP). This study was conducted on 304 nondiabetic blacks (mean age=32 years). Measurements in all subjects included BP, anthropometric measures, oral glucose tolerance test, insulin clamp to measure insulin sensitivity, and plasma lipids. The sample was stratified according to plasma glucose on oral glucose tolerance test to normal glucose tolerance (NGT), impaired glucose tolerance (IGT), and diabetes mellitus (DM). A 2-way ANOVA was performed to determine differences between the metabolic groups. With the use of American Diabetic Association criteria, 20.4% of the samples were classified as IGT and 5.9% were diabetic. A significant increase in BP existed from NGT to IGT to DM, which was stronger in women than men (systolic blood pressure in women: NGT=122, IGT=127, and DM=140 mm Hg, P<0.001) with a significant linear trend (P<0.001). With the use of body mass index as a covariate, the group difference in BP remained significant (P=0.006). Measures of insulin sensitivity demonstrated significant metabolic group differences (P<0.001) with a linear trend (P<0.001) of decreasing insulin sensitivity from NGT to DM. These results indicate that early alterations in glucose metabolism effects an upward shift in BP. The higher BP in IGT and DM may be due to vascular endothelial cell resistance to insulin action.     

Do we need ‘new’ omega-3 polyunsaturated fatty acids formulations?

The therapeutic value of omega-3 polyunsaturated fatty acids (PUFAs), mainly (but not only) found in fish oils, eicosapentaenoic and docosahexaenoic acids (EPA and DHA, respectively), has been extensively studied in a wide variety of disease conditions, predominantly in cardiovascular disease. However, the significant difference in efficacy observed in various conditions with different dosages seems to be at least partly related to the large discrepancy in quality of the product and to the bioavailability of the omega-3 PUFA. The research of new sources (e.g., from arctic Krill oil) and pharmaceutical forms of omega-3 PUFA (e.g., omega-3 carboxylic acids) is needed in order to detect the one with the best bioavailability and efficacy, and with a parallel reduction in the production costs. There is also the need to understand if long-term PUFA supplementation could increase the efficacy of the already-available evidence–based therapies for cardiovascular disease prevention and for the management of the diseases where the use of PUFA could have a possible improving effect.     

DLA-identical bone marrow grafts after low-dose total body irradiation: effects of high-dose corticosteroids and cyclosporine on engraftment

Previous studies found that marrow allografts from DLA-identical littermates resulted in survival of 60% of recipient dogs after an otherwise lethal dose of 450 cGy of total body irradiation (TBI), either because of successful allografts or autologous recovery after rejection of the allografts. Forty percent of dogs died with marrow aplasia after allograft rejection. The current study asked whether allogeneic engraftment could be enhanced and survival improved by treating allograft recipients with high doses of corticosteroids or with cyclosporine (CSP), administered either before or after transplantation. Five dogs in group 1 received corticosteroids beginning on day -5 and ending on day 32 after transplant. The starting dose was 12.5 mg of prednisone per kilogram orally twice daily. All five dogs rejected their allografts; three died early with marrow aplasia and two showed endogenous marrow recovery. Nine dogs received CSP from day -6 to day -1 before transplantation at a dose of 20 mg/kg/d intravenously administered in divided doses. All nine dogs rejected the marrow allograft; six died with marrow aplasia and three survived with endogenous marrow recovery. Seven dogs received CSP after transplantation at a dose of 30 mg/kg/d orally from day -1 to day 35. All seven had sustained allografts (two mixed chimeras and five complete donor-type chimeras) and became healthy long-term survivors without graft-versus-host disease. These results extend previous observations and confirm that grafts of marrow from DLA-identical littermates improved survival of dogs exposed to low but otherwise lethal doses of TBI. Additional therapy with high-dose corticosteroids administered peritransplantation and posttransplantation or CSP administered before transplantation neither enhanced the rate of allogeneic engraftment nor improved survival; however, CSP administered after transplantation resulted in successful allografts and event-free survival in all cases.     

Platelets express a membrane protein complex immunologically related to the fibroblast fibronectin receptor and distinct from GPIIb/IIIa

We have previously identified and characterized a membrane glycoprotein complex (GP150/135) that functions as fibronectin receptor (FN-R) in fibroblast adhesion. Here we report that an immunologically related protein complex is expressed at the surface of human platelets. Antibodies monospecific for the smaller subunit (GP135) of the fibroblast FN-R in fact specifically stained the platelet surface, as determined by FACS analysis, and reacted with a component of molecular weight (mol wt) 138,000 as shown in western blots of platelet membranes. Moreover, the same antibodies precipitated the 138,000 component together with a 160,000 protein, suggesting that the two molecules are associated in a supramolecular complex. A comparative analysis indicated that this protein complex is distinct from the GPIIb/IIIa complex, known to function as a receptor of wide specificity for fibrinogen, fibronectin, and von Willebrand factor. Differential extraction experiments revealed that the platelet 138,000 component is an integral membrane protein.     

Effect of recombinant canine granulocyte-macrophage colony-stimulating factor on hematopoietic recovery after otherwise lethal total body irradiation

Recombinant canine granulocyte-macrophage colony-stimulating factor (rcGM-CSF) was studied in normal dogs and in dogs receiving otherwise lethal total body irradiation (TBI) without marrow transplant. Five normal dogs receiving 25 micrograms/kg of rcGM-CSF by subcutaneous (SC) injection twice daily (BID) for 14 days showed increases in peripheral blood neutrophil counts of three to five times the baseline. Platelet counts decreased during administration of rcGM-CSF to a mean nadir of 52,800. Ten dogs received 400 cGy TBI at 10 cGy/min from two opposing 60Co sources and no marrow graft. Within 2 hours of TBI, rcGM-CSF was begun at a dose of 50 micrograms/kg SC BID for 5 doses and then continued at 25 micrograms/kg SC BID for 21 days. Only 1 of the 10 dogs receiving rcGM-CSF survived with complete and sustained recovery of hematopoiesis. One of 13 historical control dogs survived after 400 cGy with no hematopoietic growth factor or marrow infusion. Results with rcGM-CSF were compared with previous and concurrent data with G-CSF studied in the same model. Of 10 dogs receiving G-CSF, 8 survived with complete and sustained hematopoietic recovery, a significantly better survival than that seen with rcGM-CSF (P = .006). Neutrophil counts were sustained at higher levels after TBI for the first 18 days in the G-CSF group (P < .016) and the neutrophil nadirs were higher. No differences in neutrophil nadirs were noted between the rcGM-CSF and control groups. Dogs treated with rcGM-CSF experienced a more rapid decline of platelet counts than G-CSF-treated or control dogs over the first 18 days (P < .001). The nadir of the platelet count was higher in the control group than in either the G-CSF or rcGM-CSF group and no significant difference was observed between the G-CSF and rcGM-CSF groups. After otherwise lethal TBI (400 cGy) in dogs, rcGM-CSF was not effective in promoting hematopoietic recovery or improving survival.     

Homozygous transcobalamin II deficiency maintained on oral hydroxocobalamin

A case of transcobalamin II (TCII) deficiency in which a total absence of TCII was demonstrated both functionally and immunologically is reported. Unlike previously described patients, this child has been maintained on oral hydroxocobalamin, 2 mg daily, without any parenteral supplementation for the last five years. At the age of six years her development is normal and her health is good. Plasma cobalamin levels are in the range of 3,000 ng/L and most of this appears to be bound to a molecule, which on gel filtration, elutes with albumin. In an extended family study, a clear separation of heterozygotes from both the propositus and from normal subjects suggests that the underlying defect in this condition is confined to a single gene.     

Obesity and high blood pressure: a clinical phenotype for the insulin resistance syndrome in African Americans

The high prevalence of insulin resistance syndrome in African Americans predisposes this population to higher morbidity and mortality from cardiovascular disease. To test the hypothesis that the combination of obesity and high blood pressure (BP) represents the physical phenotype of insulin resistance syndrome, 337 African-American men and women aged 32+/-4 years were examined and classified into four groups (nonobese-normal BP, nonobese-high BP, obese-normal BP, obese-high BP), according to presence or absence of obesity and high BP. Mean values of glucose, insulin, lipids, urinary albumin excretion, and clamp-derived insulin sensitivity were determined for each group. Prevalence of prediabetes (24.4%), diabetes (19.2%), and insulin resistance syndrome (87.2%) were highest in the obese-high BP group (p<0.001). Mean triglycerides, urinary albumin excretion, fasting glucose, fasting insulin, and insulin resistance were highest in the obese-high BP group (p<0.001). Subjects with both obesity and high BP showed greater expression of lipid and glucose abnormalities, higher urinary albumin excretion, and greater prevalence of prediabetes, undetected type 2 diabetes, and insulin resistance syndrome.     

The use of different measurements and definitions of periodontal disease in the study of the association between periodontal disease and risk of myocardial infarction

BACKGROUND: The role of periodontal disease as an independent risk factor for cardiovascular disease (CVD) has been under debate because of the inconsistency of findings across studies. One of the major issues is the method used to assess or define periodontal disease. The present study assesses if the observed association between periodontal disease and incident myocardial infarction (MI) depends on the measurements and/or criteria used to define periodontal disease. METHODS: A population-based case-control study to evaluate the association between PD and risk of MI was conducted between 1997 and 2001 in Western New York with 537 cases and 800 controls, aged 35 to 69 years. Cases were survivors of incident MI from local hospitals in Erie and Niagara counties. Controls were randomly selected from residents of the same counties. Periodontal disease was assessed using interproximal clinical attachment loss (CAL), probing depth (PD), alveolar crest height (ACH), and number of missing teeth. From these measurements, four different case definitions of periodontal disease were created. RESULTS: Using the continuous forms of periodontal measurements, the odds ratios (ORs) (95% confidence interval) of the association with incident MI were 1.46 (1.26 to 1.69), 2.19 (1.66 to 2.89), 1.30 (1.14 to 1.49), and 1.04 (1.02 to 1.07) for mean CAL, PD, ACH, and number of missing teeth, respectively. Regardless of the case definition of periodontal disease, the estimates of the association with incident MI were statistically significant. CONCLUSIONS: The observed association between periodontal disease and incident MI was consistent across different measurements and/or case definitions of periodontal disease used. The magnitude of the association varies depending on the measurements or the criteria used to define periodontal disease.