Primary prevention of malignant melanoma in the Stockholm Cancer Prevention Programme

The relation between intracoronary thrombus and endothelin-1 (ET-1) was studied. In a canine model, acute myocardial infarction (MI) was induced by coronary occlusive thrombus produced at a mock atheromatous plaque. Blood samples were collected from the aorta (A) and coronary vein (V). Twenty-eight open-chest dogs divided into three groups were studied. Group I (n = 15): acute MI was induced by coronary occlusive thrombus, and thrombolysis was obtained by urokinase two hours after MI. Group II (n = 8): nonocclusive thrombus was produced without inducing MI. Group III (n = 5): coronary artery was ligated for two hours and reperfused by release of ligation. In Group I, ET-1 was significantly increased after MI in A and V, and ET-1 in V was significantly more elevated than in A during thrombolysis, suggesting ET-1 production in the coronary vessels by thrombolysis. In Group II, ET-1 increased slightly during thrombus formation, but there was no difference in A and V. In Group III, ET-1 was elevated significantly after MI without A and V difference. These results indicate that there is no detectable ET-1 production with coronary thrombus formation, whereas coronary ET-1 production is detected during thrombolysis, most probably because resolved thrombus releases a more potent stimulus to ET-1 production.     

Human chromosome 5 sequence primer amplifies Alu polymorphisms on chromosomes 2 and 17

Members of the Alu family of repetitive elements occur frequently in the human genome and are often polymorphic. Techniques involving Alu element mediated polymerase chain reactions (Alu PCR) allow the isolation of region-specific human DNA fragments from mixed DNA sources. Such fragments are a source of region-specific Alu elements useful for the detection of Alu-related polymorphisms. A clone from human chromosome 5, corresponding to locus D5F40S1, was isolated using Alu PCR differential hybridization. Alu elements within this clone were investigated for the presence of potentially polymorphic 3' polyA tails. Primers were devised to amplify the 3' polyA tail of an Alu element present within the clone. One primer, D5F40S1-T, was specific to the DNA flanking the 3' end of the Alu element, and the other primer was homologous to sequences within the element. When these primers were used in PCR reactions, products from chromosomes 2 and 17 (loci D2F40S2 and D17F40S3) were amplified in addition to the expected product from chromosome 5. The most likely explanation for this nonspecific amplification is that the D5F40S1-T primer is located within a low-copy repetitive element that is 3' of the Alu element. This phenomenon presents a potential problem for the identification of region-specific Alu polymorphisms.     

Central adiposity and hemodynamic functioning at rest and during stress in adolescents

OBJECTIVE: To examine the impact of central adiposity upon hemodynamic functioning at rest and during stress in adolescents. DESIGN: Cross-sectional, correlational study. SUBJECTS: 46 White and 49 Black normotensive adolescents with family histories of essential hypertension. MEASUREMENTS: Systolic and diastolic blood pressure (SBP, DBP), cardiac output and total peripheral resistance responses were assessed at rest, during postural change, video game challenge and forehead cold stimulation. Specific lower and higher waist-to-hip ratio (WHR) tertiles were created for each gender and then integrated for analyses. This resulted in a lower WHR tertile of 11 Whites and 21 Blacks and an upper WHR tertile of 15 Whites and 17 Blacks. RESULTS: No differences in age, gender or ethnicity proportions were found between tertile groups (all P > 0.21). The upper WHR group showed greater body weight, waist and hip circumferences, body mass index (BMI), triceps skinfold and body surface area (all P < 0.001). Controlling for peripheral (that is, triceps skinfold) and overall (that is, BMI) adiposity, the upper WHR group exhibited greater SBP (that is, peak response minus mean pre-stressor level) to all three stressors and greater DBP reactivity to postural change and cold pressor (all P < 0.05). CONCLUSION: Central adiposity appears to adversely influence hemodynamic functioning during adolescence. Underlying mechanisms responsible for these associations require exploration.     

Pediatric malignant glioma with tubuloreticular inclusions and MYCN amplification. Report of a case with immunohistochemical, ultrastructural, flow cytometric, karyotypic, and Southern blot analysis

BACKGROUND: The authors described unusual pathologic features in a left frontal lobe malignant glioma in a 31/2-year-old boy. The pathology was similar in the initial excision and two subsequent recurrences at 9 and 11 months and at autopsy, when extensive subarachnoid spread was noted. METHODS: The tumor was studied by conventional histology, immunohistochemistry, flow cytometry, transmission electron microscopy (TEM), immune electron microscopy (IEM), and cytogenetic and Southern blot analysis. RESULTS: The tumor revealed two different histologic patterns. One component showed large cells with eosinophilic cytoplasm, vesicular nuclei with prominent nucleoli, eosinophilic perinuclear inclusions, and immunoreactivity for glial fibrillary acidic protein (GFAP) and vimentin. The other component consisted of undifferentiated cells with hyperchromatic nuclei and scanty cytoplasm. By TEM, the perinuclear aggregates were composed of tubuloreticular inclusions, which were also observed in endothelial cells within the tumor vasculature. By IEM, the intermediate filaments in the tumor cell cytoplasm were decorated with GFAP. Flow cytometric results revealed a marked increase in the S-phase (48%), whereas cytogenetic analysis of short-term cultures showed an abnormal karyotype containing marker chromosomes and double minutes. In the second resection, additional karyotypic abnormalities were noted, including 1p- and several additional markers. The first and second resections showed MYCN amplification by Southern Blot analysis in the 60- to 80-fold range. CONCLUSIONS: This tumor presents unique histologic, ultrastructural, and cytogenetic findings as well as MYCN amplification that is notable for a pediatric malignant glioma. Tubuloreticular inclusions were a prominent feature in this tumor, which again is unique for a glioma.     

Assessing disability after head injury: improved use of the Glasgow Outcome Scale

OBJECTIVE: The objective of this study was to assess somatic and inherited androgen receptor gene mutations in families with only one affected individual. METHODS: Molecular genetic analysis of the androgen receptor gene in DNA derived from blood leukocytes from 30 families with single-strand conformation analysis, direct sequencing, and restriction fragment analysis was performed. RESULTS: In 22 families the mothers and all investigated grandmothers were heterozygous carriers. However, within the sisters and aunts, both heterozygous carriers and noncarriers were present. In eight families a de novo mutation was characterized. In three of these patients indication for somatic mosaicism was found. CONCLUSIONS: De novo mutations occur at a high rate within the androgen receptor gene (8 of 30 = 26.7%); a high proportion (3 of 8) arise after the zygote stage. Thus only direct analysis of the underlying mutation of the androgen receptor gene in the proband and his or her family can provide the basis for genetic counseling.     

Determination of erythema-effective solar radiation in Japan and Germany with a spore monolayer film optimized for the detection of UVB and UVA--results of a field campaign

A centrifugation method was used to investigate the accumulation of 14C-rifampicin by Staphylococcus aureus and Escherichia coli, and to characterize the mechanism of rifampicin transport into S. aureus. For both species, drug accumulation was rapid with the steady-state concentration (SSC) reached within 40 s of drug exposure. Rifampicin accumulation by S. aureus was temperature and pH dependent; the lower the experimental temperature and the lower the experimental pH, the lower was the concentration of rifampicin accumulated. Accumulation was unaffected by the presence of inhibitors of antibiotic efflux, carbonyl cyanide m-chlorophenylhydrazone (CCCP), dinitrophenol (DNP), or reserpine. Exposure to increasing concentrations of rifampicin suggested that the accumulation process was saturable above a rifampicin concentration of 0.2 mg/L. Michaelis-Menten kinetics gave an apparent Km and Vmax for rifampicin, calculated from a Lineweaver-Burk plot, of 0.05 mg/L (0.06 microM) and 3.8 ng rifampicin per second, respectively. However, calculations suggest that these values reflect those for binding of rifampicin to its target, RNA polymerase.     

Quantitation of intrathecal measles virus IgG antibody synthesis rate: subacute sclerosing panencephalitis and multiple sclerosis

A method for quantitating specific anti-viral antibodies in serum and cerebrospinal fluid (CSF) is established using enzyme-linked immunosorbent assay (ELISA). Quantitated antibody levels are used to determine intrathecal specific IgG synthesis rate for the particular antibody. Measles virus was used as a model for validating this quantitative technique: a mutated form of measles virus is a cause of subacute sclerosing panencephalitis (SSPE) and there is a possibility that measles virus is related to the cause of multiple sclerosis (MS). Matched serum and CSF samples were assayed. Concentration of anti-measles IgG was determined and intrathecal measles-specific IgG synthesis rate was calculated. For the SSPE samples, measles-specific IgG synthesis rate was elevated and comprised > 20% of the total intrathecal IgG synthesis rate; these results are consistent with the literature. The ELISA method can be performed routinely, providing a quick, simple, reproducible means of quantitating specific antibody concentrations, with sensitivity greater than 1 nanogram per milliliter. With this method, quantitation of IgG antibodies to any other viral antigen can be reliably and precisely determined.     

Cytoplasmic mRNA for human triosephosphate isomerase is immune to nonsense-mediated decay despite forming polysomes

Nonsense codons between position 14 within the first exon and position 193 within the penultimate exon of the human gene for triosephosphate isomerase reduce mRNA abundance to 25% of normal. The reduction in abundance is due to the decay of newly synthesized mRNA that copurifies with nuclei. TPI mRNA that copurifies with cytoplasm is immune to decay. We show here that immunity is not due to the failure of nonsense-containing mRNA to form polysomes. This finding indicates that cytoplasmic mRNA, in contrast to nucleus-associated mRNA, may have lost one or more factors that are required for nonsense-mediated decay or gained one or more factors that confer immunity to nonsense-mediated decay.