Improved power control during microwave heating in biological applications.

The heating performance of prototype variable power control units attached to two domestic microwave ovens, 500 W and 700 W, was investigated. The units employed the phase control method where rated voltage was obtained by switching AC supply at a particular angular position on the sinusoidal voltage. In order to create experimental conditions employed in a previous study, Sydney tap water (50 mL) was heated at a 10% power level in the 500 W oven. Water boiled at 10 min in both experiments. However, the precision and control of the heating was greatly improved with addition of the control unit. A disinfecting solution (50 mL) and a tissue fixative (10 mL) were included for experiments with the 700 W oven. A power level of only 1% was sufficient to maintain the temperature of the fixative at low temperatures (30-40 degrees C) where many biological reactions occur. The present results indicate that microwave heating power can be controlled by the variable power control method. This will make temperature control possible through the provision of an electronic feedback loop which links a thermocouple with the power control unit.     

Music therapy: an intervention to reduce anxiety in the myocardial infarction patient.

The purpose of this study was to examine the effects of relaxing music on elevated state anxiety in patients with a confirmed medical diagnosis of acute myocardial infarction. In addition, the relationship between trait anxiety and state anxiety was analyzed. A purposive sample of 40 myocardial infarction patients was randomly assigned to an experimental or control group. Statistically significant reduction in heart rate, respiratory rate, and state anxiety scores were found in the group that listened to relaxing music. A statistically significant positive correlation was found between trait anxiety scores and baseline state anxiety scores. Statistically significant negative correlations were found between trait anxiety scores and the degree of change in posttreatment state anxiety scores when examined as a net change, as well as a percent change. Results suggested that music therapy may be an effective intervention to reduce state anxiety levels in the acute myocardial infarction patient.     

Cluster headache: phospholipid metabolism in polymorphonuclear cells

Our group has previously reported significant changes in the incorporation of precursors into glycerophospholipids, particularly phosphatidylserine, in polymorphonuclear cells obtained from the peripheral blood of cluster headache patients, when compared with controls. The potential of these results led to further work using both the previous methodology and a modified isolation technique to obtain polymorphonuclear cells in as pure a state as possible. Neither the new results obtained using the original technique, nor the results with high purity polymorphonuclear cells from controls and cluster headache patients, confirm the marked changes in precursor uptake into glycerophospholipids originally reported.     

Identifying incident cases of parkinsonism among veterans using a tertiary medical center.

To better understand the impact of incident Parkinson's disease (PD) on the Veteran's Health Administration (VHA) and to develop methods applicable to future epidemiological research, we performed a medical record review study at a tertiary referral VHA medical center. Searching the local data base, we identified 782 veterans with diagnostic codes for PD or secondary parkinsonism (SP) between 1998 and 2000. Based on structured medical record review, a movement disorders specialist confirmed diagnoses for incident parkinsonism cases. Among the 782, 191 incident parkinsonism cases were identified (100 PD, 75 SP, and 16 Parkinson's Plus). Incident PD cases were older at diagnosis (74.5 vs. 70.4 yr; P < 0.05) and more likely to be white (81% vs. 62; P < 0.07) than incident SP cases. Diagnostic codes were insufficient to distinguish between incident PD and SP (positive predictive value, 57% and 39%, respectively), and VHA sources failed to identify 21% of confirmed deaths among the incident PD cohort by November 2004. Although the large number of incident cases identified suggests PD is an important cause of disability among elderly VHA users, observed limitations of VHA sources for identifying incident PD cases and determining their vital status should be considered when designing future studies.     

Angioid streaks associated with abetalipoproteinemia

Angioid streaks were observed in a 31-year-old man with abetalipoproteinemia. Angioid streaks have now been described in hereditary spherocytosis, beta thalassemia, alpha thalassemia, sickle cell anemia, and acanthocytosis secondary to abetalipoproteinemia and hypobetalipoproteinemia. The nature of the association of angioid streaks and structural defects of hemoglobin and the red blood cell is not understood.     

Risk indicators for third molar caries and periodontal disease in senior adults.

PURPOSE: This study was designed to identify risk indicators for the prevalence at enrollment and incidence over 36 months of periodontal pathology and coronal caries experience affecting third molars in a community-based study of people over 65 years of age. SUBJECTS AND METHODS: Data from a subsample of 810 dentate subjects from the Piedmont 65+ Study were available for analyses. All visible teeth were examined. Periodontal probing measures were taken at 2 sites, mesiobuccal and buccal/facial. Clinical data on caries experience were collected by visual-tactile examination. At enrollment, 340 subjects had at least 1 visible third molar; all were examined for caries experience. Periodontal probing measures were available for 277 of these same subjects. The significance of the possible risk indicators for periodontal pathology and caries affecting third molars was determined by chi(2) tests. Statistical significance was set at .05. Logistic multivariable models were used to derive odds ratios and 95% confidence intervals. RESULTS: African-American subjects were more likely to have visible third molars (P < .01). Caucasian subjects were more likely to have third molar coronal caries experience (P < .01), as were subjects with greater than a high school education and those with a dental visit within 3 years (both P < .01). However, African American subjects were more likely to have periodontal pathology, CALs >/= 3 mm on third molars (P < .01), as were those who used tobacco (P < .01). None of the other risk indicators we studied were associated with progression of periodontal pathology or coronal caries experience on visible third molars. CONCLUSION: In this population study of senior adults, Caucasians and African Americans appear to have different levels of risk for caries experience and periodontal pathology affecting retained third molars.     

In situ saphenous vein bypass grafts: angiographic evaluation and interventional repair of complications

In situ saphenous vein grafts are being used with increasing frequency for bypass procedures involving the femoral and popliteal arteries. Complications of these procedures include anastomotic stenoses and persistent arteriovenous fistulae that may result in failure of the graft. Balloon angioplasty and embolotherapy with detachable balloons were employed successfully in three or four recent cases of patients with complications from in situ grafts. Tailored angiography is essential for evaluating in situ grafts, and interventional techniques are extremely useful for managing complications.     

Suppression of the vitro humoral immune response of mouse splenocytes by benzo(a)pyrene metabolites and inhibition of benzo(a)pyrene-induced immunosuppression by alpha-naphthoflavone

Several investigators have demonstrated that the humoral immune response of mice and splenocyte cultures was suppressed with benzo(a)pyrene [B(a)P] exposure. The mechanism of the B(a)P immunosuppression, however, has not been established. Since reactive metabolites of B(a)P, rather than the parent compound, have been shown to mediate the carcinogenic effects of B(a)P, it was hypothesized that the immunosuppression produced by B(a)P may also be mediated by its reactive metabolites. The objective of this investigation was to examine the role of B(a)P metabolism in the B(a)P-induced suppression of the in vitro humoral immune response. This was addressed by first determining if various B(a)P metabolites are capable of inhibiting the generation of antibody-forming cells (AFC) of splenocyte cultures. Addition of B(a)P or B(a)P-7,8-diol (2 X 10(-5) M) to splenocyte cultures produced a similar dose-dependent suppression of the in vitro T-dependent AFC response to sheep red blood cells. In contrast, decreases in the AFC response and cell viability of cultures exposed to the 4,5-diol or 9,10-diol were only observed at 2 X 10(-5) M. Exposure of cultures to 3-hydroxy-B(a)P resulted in a significant decrease in the AFC response at 2 X 10(-6) and 2 X 10(-5) M. Slight decreases in the AFC response were observed with the addition of B(a)P-4,5-epoxide or B(a)P-6,12-dione at 2 X 10(-6) M, whereas a dramatic decrease in the AFC response, as well as a 45% decrease in cell viability, was obtained at 2 X 10(-5) M. The second objective was to examine the effects of the cytochrome P-450 inhibitor, alpha-naphthoflavone (ANF), on the B(a)P- and B(a)P-7,8-diol-induced suppression of the in vitro AFC response. Exposure of splenocyte cultures to 2 X 10(-5) M ANF did not affect the AFC response. Coincubation of splenocytes with ANF was observed to attenuate the suppressive effects of B(a)P and B(a)P-7,8-diol. This concentration of ANF was observed to inhibit the metabolism of [3H]B(a)P by splenocyte cultures to water soluble metabolites. Moreover, B(a)P metabolism by splenic microsomal preparations of untreated mice was inhibited by ANF. These findings suggest that the B(a)P-induced suppression of the in vitro AFC response is mediated by B(a)P metabolites generated by cytochrome P-450 present within splenocytes.