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Biomedical subjects

J Sparling

Publications and source records attributed to J Sparling.

9 recordsLinked to original sources
PubMed1997

Penile erections: shape, angle, and length.

A U.S. Census-matched sample of 1,484 men between 20 and 69 years old from archived data of the Kinsey Institute and current questionnaire plus documentary photo data from a new sample of 81 men between 21 and 67 years old were analyzed to generate a description of penile erections that might act as a useful information base for therapists and others. Estimates derived from Kinsey data on erections were found to provide a credible foundation of fact, with the current questionnaire and photo analysis implying the need for moderate increases in the Kinsey figures in three areas: (a) more n-curved (downward curved) erections, about 15% of the total; (b) more erection angles in the lower ranges, with at least one fourth below horizontal; and (c) a greater proportion of shorter erections, with lengths in the 4.5-5.75 in. range, representing about 40% of the total.

Adult↗
PubMed1995

Interruption in the medical interaction.

OBJECTIVES: To describe patterns of interruption in the physician-patient interaction; specifically, to determine who interrupts, to determine if a shift in control occurs as a result of interruption, and to characterize the information gained when patients interrupt physicians. DESIGN: Observational. SETTING: Community-based primary care practices in North Carolina. SUBJECTS: Internists and family physicians in private practice in North Carolina (six men and two women) and their patients (13 men and 27 women). INTERVENTIONS: None. MAIN OUTCOME MEASURE: The obtainment of control of the interaction, at least momentarily, as a result of interruption. RESULTS: Analysis of 40 audiotaped interactions revealed 833 interruptions (mean +/- SD, 20.8 +/- 12.2 per interaction): Patients initiated 55% of all interruptions. Physicians and patients each gained control of the conversation after 50% of interruptions. Patients gained control after 74% of patient-initiated interruptions, and physicians gained control after 79% of physician-initiated interruptions. Patients were more likely to gain control by interrupting late in the interaction, and 75% of patient-initiated interruptions resulted in new information (solicited and unsolicited) being contributed to the interaction. CONCLUSION: Interruption by patients can be an informative event.

Adult↗
PubMed1985

Effects of structure on binding to the 2,3,7,8-TCDD receptor protein and AHH induction--halogenated biphenyls.

The quantitative structure-activity relationships (QSARs) for polychlorinated biphenyl (PCB) congeners have been determined by comparing the EC50 values for three in vitro test systems, namely, aryl hydrocarbon hydroxylase (AHH) and ethoxyresorufin O-deethylase (EROD) induction in rat hepatoma H-4-II-E cells and competitive binding avidities to the rat cytosolic receptor protein (using 2,3,7,8-tetrachlorodibenzo-p-dioxin as a radioligand). For several PCB congeners that are in vivo inducers of rat hepatic microsomal AHH, there was a linear correlation between the -log EC50 values for receptor and the -log EC50 values for AHH (or EROD) induction; moreover, a comparable linear relationship was observed between the -log EC50 values for AHH and EROD induction. Previous in vivo studies have shown that the most active PCB congeners 3,3',4,4'-tetra-, 3,4,4',5-tetra-, 3,3',4,4',5-penta-, and 3,3',4,4',5,5'-hexachlorobiphenyl, cause many of the biologic and toxic effects reported for the highly toxic halogenated aryl hydrocarbon, 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). Moreover, the monoortho-substituted homologs of the four coplanar PCBs also elicit comparable in vivo biologic and toxic responses. It was evident from the QSARs for PCBs that there was an excellent correspondence between the in vivo and in vitro potencies of the individual PCB congeners. The effects of substituents on both receptor binding and AHH/EROD induction was determined for a series of 4'-substituted (X)-2,3,4,5-tetrachlorobiphenyls (where X = H, Cl, Br, I, OH, OCH3, NO2, COCH3, F, CF3, CH3, C2H5, i-C3H7, n-C4H9 and t-C4H9). Not unexpectedly, there was a linear relationship between the -log EC50 values for AHH and EROD induction, and these results confirm that both enzymatic oxidations are catalyzed by the same cytochrome P-450 isozyme(s). The effects of substituent structure on receptor binding for 12 substituents was subjected to multiple regression analysis which correlates the relative binding affinities of the compounds with the physical chemical characteristics of the substituents. The analysis gave the following equation: log (1/EC50) = 1.53 sigma + 1.47 pi + 1.09 HB + 4.08 for n = 12, s = 0.18, r = 0.978; where n is the number of substituents, s is the standard deviation, r is the correlation coefficient, and sigma = electronegativity, pi = hydrophobicity (log P) and HB = hydrogen bonding capacity for the substituent groups.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1980

Bromo and chlorobiphenyl metabolism: gas chromatography mass spectrometric identification of urinary metabolites and the effects of structure on their rates of excretion.

The identification of the hydroxylated rat urinary metabolites of the 2-, 3- and 4-chlorobiphenyls and 2-, 3- and 4-bromobiphenyls has been determined by gas chromatographic mass spectrometric analysis of their corresponding methyl ether derivatives. The electron impact fragmentation patterns of the bromotheoxybiphenyls and chloromethoxybiphenyls were used to assign the position of the methyoxyl group (ortho, meta or para to the biphenyl bond); the mass spectra of the corresponding [2H5]halobiphenyls confirmed the sites of the hydroxylation by distinguishing between the halophenyl and phenyl rings. The results illustrated that ring hydroxylation occurs predominantly at the para positions of the biphenyl nucleus and at sites which are ortho and para to the halogen substituents. 4,4'-Dimethoxyhalobiphenyls are major urinary metabolites of the 2- and 3-halobiphenyls and the rapid formation of these metabolites is illustrated in a time course study which monitors the urinary metabolites formed after the separate coadministration of the isomeric chlorobiphenyl and bromobiphenyl substrates to rats.

Animals↗
PubMed1980

The effects of ortho chloro substituents on the retention of PCB isomers in rat, rabbit, Japanese quail, guinea pig and trout.

A mixture of 2,2',4,4',6,6'-,2,2',4,4',5',6-,2,2',4,4',5,5'-,2',3,4,4',5,5'- and 3,3',4,4',5,5'-hexachlorobiphenyls (HCBP) was administered by gastric lavage to rats, guinea pigs, rabbits, Japanese quail and trout, and the concentrations in the fat or whole carcass were determined after 29 days. The total HCBP levels in rat, rabbit and guinea pig fatty tissue were 8.27, 6.84 and 4.74 ppm, respectively: whereas 3.02 and 2.15 ppm of the HCBPs were detected in the trout and Japanese quail carcasses. The extent of ortho chloro substitution markedly affected the levels of the individual HCBP isomers retained in the test animals; the rabbit and guinea pig preferentially retained the HCBPs with 0,1 and 2 ortho chloro substituents, the Japanese quail retained only the 3,3',4,4',5,5'-HCBP isomer, whereas no striking preferences in HCBP isomer retention in the rat and trout were observed. The marked differences in the retention of HCBP isomers with 0, 1, 2, 3 and 4 ortho chloro substitution by different animal species should be considered in chronic toxicity studies since the most toxic polychlorinated biphenyls have minimal (1 or 0) ortho chloro substituents.

Adipose Tissue↗