Familial and metabolic factors related to blood pressure in Pima Indian children

High blood pressure, abnormal glucose tolerance, and obesity are frequently associated with each other, but the mechanism of these associations is poorly understood. Studying them in children may help in understanding the pathogenesis of hypertension. Blood pressure, height, weight, and plasma glucose and serum insulin concentrations during a 75-g oral glucose tolerance test were measured in 1,698 Pima Indian children aged 6-17 years who participated in an ongoing epidemiologic study. Weight relative to height was used as an index of obesity. The parents of many of the children were also examined. Fasting and 2-hour glucose and insulin concentrations, adjusted for age, sex, and relative weight, were positively related to systolic blood pressure but not to diastolic blood pressure. Relative weight, 2-hour glucose, and fasting insulin concentrations were independently and significantly associated with systolic blood pressure in a stepwise regression analysis that included age and sex. After parental hypertension was taken into account, maternal but not paternal non-insulin-dependent diabetes mellitus, controlled for the child's relative weight and glucose and insulin concentrations, was significantly associated with higher blood pressure in children. The stronger association with maternal diabetes suggests a greater sharing of environmental factors between mother and child than between father and child, but familial similarities in obesity and glucose and insulin concentrations, the diabetic intrauterine milieu, and shared environmental factors probably all contribute to this association.     

Effect of grain boundary structure on sensitization and corrosion of stainless steel

This paper reports on the influence of misorientation angle and structure of a grain boundary on the sensitization and grain boundary corrosion of austenitic and ferritic stainless steels. To establish grain boundary atomic structure, orientation information of the adjacent grains, obtained with the electron backscattering (EBS) technique, was combined with the SEM image of the surface to obtain the orientation of the grain boundary. Modeling of the grain boundary structure was based on ideal crystallography and the coincident site lattice concept. The results support the concepts (1) of a threshold misorientation angle whose value is a function of the aging time and temperature, below which boundaries are of sufficiently low energy that sensitization does not occur, and (2) of a major role of grain boundary structure in explaining the wide variation in sensitization that occurs in grain boundaries of misorientation angle greater than the threshold value. It was also found that the grain boundary corrosion mechanism is not simply the dissolution of chromium depleted alloy since the observed groove widths were 10 to 100 times larger than the Cr-profile widths.     

1.8-THz bandwidth, zero-frequency error, tunable optical combgenerator for DWDM applications

We report on the experimental realization of a simple optical comb generator, based on phase modulation within an amplified fiber loop, which offers exact referencing to an arbitrary supplied reference frequency and tunable comb-line spacing. At a reference wavelength of 1529 nm up to 103 comb lines within a 40-dB power envelope were generated with spacings adjustable from 1 to 25 GHz, limited only by the bandwidth of the phase modulator     

A new model system for lipid interactions in stratum corneum vesicles: effects of lipid composition, calcium, and pH

We prepared large unilamellar vesicles (LUVs) with three different stratum corneum lipid compositions: constant amounts of ceramides (55 wt %) and fatty acids (15%) with varying amounts of cholesterol sulfate (0-15%) and cholesterol (15-30%). One of the compositions served as a model for normal stratum corneum, while the second one served as a model for recessive X-linked ichthyosis stratum corneum. The third composition consisted of no cholesterol sulfate. Intervesicle lipid interactions in these LUVs were monitored by fluorescence methods for content leakage, and contents mixing at pH 9, in the absence and presence of Ca2+, and at pH 6. Since the content leakage and contents mixing assays were originally developed for phospholipid vesicles, we characterized the probe binding and the probe quenching properties for stratum corneum LUV systems, and modified the assays slightly accordingly. The time-dependent fluorescence intensity changes in the probe-containing LUVs at pH 9 and 6 and in response to the addition of calcium were monitored. Our results demonstrated that all three types of LUVs were relatively stable at pH 9. Addition of Ca2+ or decreasing the pH to 6 activated intervesicle lipid mixing followed by vesicle fusion and lysis. We found that the LUVs with no cholesterol sulfate and 30% cholesterol exhibited a more extensive Ca2+- or low-pH-activated intervesicle lipid interaction than LUVs with either 5% cholesterol sulfate and 25% cholesterol or 15% cholesterol sulfate and 15% cholesterol. These results suggest that fusogenic agents such as Ca2+ and H+ act to neutralize the fatty acids in the lipid bilayer of stratum corneum vesicles. The inclusion of 5-15% cholesterol sulfate helps to prevent the collapse of fused vesicles into other structures.     

Effects of prenatal cocaine exposure on embryonic expression of sonic hedgehog

PURPOSE: To estimate the impact of visual impairment in older Australians on the use of community support services. METHODS: In the Blue Mountains Eye Study, 3654 people aged 49 or older were examined- 82.4% of eligible residents in an area west of Sydney, Australia. Presenting and best-corrected visual acuities were measured using a LogMAR chart. Subjects were categorized as having visual impairment if their better eye read 40 or fewer letters (20/40 or worse). Interview data included marital and other socioeconomic status measures, living status (alone or with spouse or other person), use of community support services, reliance on regular help from nonspouse family members or friends, and perceived ability to go out alone. RESULTS: After adjusting for age, gender, education, living status, walking disability, and health-related factors, for each one-line (five-letter) decrease in best-corrected visual acuity, there was a corresponding increase in reliance on community support services (odds ratio [OR], 1.17; 95% confidence interval, [CI] 1.07-1.28) or combined community and family support (OR 1.22; 95% CI, 1.12-1.32). Visually impaired persons were three times as likely to use regular support services provided by the municipality (OR 3.1; 95% CI, 1.8-5.1). A similar increased reliance on regular help from community, nonspouse family members, or friends was found. Visually impaired persons were also much more likely to state that they thought they were unable to go out alone (OR 6.2; 95% CI, 2.6-14.3). The findings were similar when presenting visual acuity was used to define visual impairment or after subjects with walking disabilities were excluded. Visual impairment seemed to have a greater effect on use of community support services in women than in men. CONCLUSIONS: After adjustment was made for confounding factors, visual impairment was found to affect significantly and negatively the independence of elderly people, particularly older women. Presenting visual acuity closely approximated best-corrected visual acuity in its impact on the use of community support services.     

Intracerebral hemorrhage after carotid endarterectomy: incidence, contribution to neurologic morbidity, and predictive factors

PURPOSE: With a diminishing rate of cardiac and neurologic events after carotid endarterectomy, intracerebral hemorrhage is gaining increasing importance as a cause of perioperative morbidity and mortality. To date, information has been largely anecdotal, and there has been no comparison with a control group of patients. METHODS: The records of all patients experiencing symptomatic intracerebral hemorrhage after carotid endarterectomy were reviewed and compared with data from 50 randomly selected patients who did not experience intracranial bleeding. Univariate analyses were performed, using the Fisher exact test for dichotomous data and the Student t test for continuous data. RESULTS: During a 6-year period, symptomatic intracranial hemorrhage developed in 11 (0.75%) of 1471 patients undergoing carotid endarterectomy, accounting for 35% of the 31 total perioperative neurologic events. Hemorrhage occurred a median of 3 days postoperatively (range, 0 to 18 days). Signs and symptoms included hypertension in all 11 patients, headache in 7 conscious patients (64%), and bradycardia in 6 patients (55%). Massive hemorrhage with herniation and death occurred in 4 patients (36%). Moderate hemorrhage developed in 5 patients (45%); 3 of these patients had partial recovery, and 2 had complete recovery. Petechial hemorrhage occurred in the remaining 2 patients (18%), 1 with partial and 1 with complete recovery. In comparison with the control group, there were no differences in respect to sex, indication for operation, smoking or diabetic history, and antiplatelet therapy or perioperative heparin management. Patients with intracranial hemorrhage were, however, younger, more frequently hypertensive, had a higher degree of ipsilateral and contralateral carotid stenosis, and had a higher rate of contralateral carotid occlusion. CONCLUSION: Intracranial hemorrhage occurs with notable frequency after carotid endarterectomy and accounts for a significant proportion of neurologic morbidity and mortality. Younger patients, hypertensive patients, and patients with severe cerebrovascular occlusive disease appear to be at greatest risk for the complication.