Biomedical subjects

R Blanchard

Publications and source records attributed to R Blanchard.

At least 19 recordsLinked to original sources

PubMed2000

Turbo STIR magnetic resonance imaging as a whole-body screening tool for metastases in patients with breast carcinoma: preliminary clinical experience.

This study was undertaken to assess the utility of whole-body turbo short tau inversion recovery (STIR) magnetic resonance imaging (MRI) to detect metastases to liver, brain, and bone as a single examination in women with breast cancer. Seventeen patients with biopsy-proven breast cancer and suspected metastatic disease attending over a 12-month period referred for both conventional imaging and whole-body MRI were included in the study. Three patients were found to be free of metastases at both conventional and MR imaging. Appendicular or axial skeletal metastases were identified in 11 of 17 patients, with correlation between findings at whole-body MRI and scintigraphy in 15 of the 17 patients. Five patients had evidence of hepatic metastases on whole-body MRI, of which metastases were identified in only three patients at CT despite contrast enhancement. Four patients had brain abnormalities (metastases in three patients, meningioma in one patient) detected on both whole-body and dedicated brain MRI. Preliminary clinical experience suggests that turbo STIR whole-body MRI may represent a convenient and cost-effective method of total body screening for metastases in patients with breast carcinoma.

Adult↗

PubMed2000

Fraternal birth order and sexual orientation in pedophiles.

Whether homosexual pedophiles have more older brothers (a higher fraternal birth order) than do heterosexual pedophiles was investigated. Subjects were 260 sex offenders (against children age 14 or younger) and 260 matched volunteer controls. The subject's relative attraction to male and female children was assessed by phallometric testing in one analysis, and by his offense history in another. Both methods showed that fraternal birth order correlates with homosexuality in pedophiles, just as it does in men attracted to physically mature partners. Results suggest that fraternal birth order (or the underlying variable it represents) may prove the first identified universal factor in homosexual development. Results also argue against a previous explanation of the high prevalence of homosexuality in pedophiles (25% in this study), namely, that the factors that determine sexual preference in pedophiles are different from those that determine sexual preference in men attracted to adults. An alternative explanation in terms of canalization of development is suggested.

Adolescent↗

PubMed2000

Birth order in a contemporary sample of gay men.

The birth order of a contemporary North American sample of 97 gay men was quantified using Slater's Index. For the 84 probands with at least one sibling, the results showed a late mean birth order compared with the expected value of .50. Additional birth order indices derived from Slater's Index suggested that the mean later birth order was accounted for more strongly by the proband's number of older brothers than by his number of older sisters. The present findings constitute a replication of a series of recent studies and add to the growing body of evidence that birth order is a reliable correlate of sexual orientation in males.

Adult↗

PubMed2000

The discriminative validity of a phallometric test for pedophilic interests among adolescent sex offenders against children.

The authors examined the responses of adolescent sex offenders against children on a phallometric test of pedophilic interests. Participants were 40 adolescent sex offenders against children, 75 young adult sex offenders against children, and 39 young adult comparison participants. The responses of adolescents with female victims resembled those of comparison participants; adolescents with any male victims had larger relative responses to child stimuli than comparison participants. Young adult offenders, regardless of victim sex, had larger relative responses to child stimuli than comparison participants. Using a cut score of 0 (indicating equal or greater arousal to children than to adults), sensitivity was 42% for adolescents with any male victims, and specificity was 92% for the comparison participants. Results suggest phallometric testing can identify pedophilic interests among these adolescent sex offenders.

Adolescent↗

PubMed2000

Sexual orientation and handedness in men and women: a meta-analysis.

Recent findings suggest that sexual orientation has an early neurodevelopmental basis. Handedness, a behavioral marker of early neurodevelopment, has been associated with sexual orientation in some studies but not in others. The authors conducted a meta-analysis of 20 studies that compared the rates of non-right-handedness in 6,987 homosexual (6,182 men and 805 women) and 16,423 heterosexual (14,808 men and 1,615 women) participants. Homosexual participants had 39% greater odds of being non-right-handed. The corresponding values for homosexual men (20 contrasts) and women (9 contrasts) were 34% and 91%, respectively. The results support the notion that sexual orientation in some men and women has an early neurodevelopmental basis, but the factors responsible for the handedness-sexual orientation association require elucidation. The authors discuss 3 possibilities: cerebral laterality and prenatal exposure to sex hormones, maternal immunological reactions to the fetus, and developmental instability.

Brain↗

PubMed1999

Differential fetal and maternal contributions to the cytokine milieu in a murine model of infection-induced preterm birth.

OBJECTIVE: The aim of the study was to determine the relative productions by maternal and fetal tissues of proinflammatory and anti-inflammatory cytokines in a murine model of infection-induced preterm delivery. STUDY DESIGN: The right uterine horns of CD-1 female mice at 14.5 days of a 19- to 20-day gestation were inoculated with either sterile media or live Escherichia coli. The concentrations of cytokines within uteri, placentas, membranes, and fetal lower body segments were determined by enzyme-linked immunosorbent assay at various times after inoculation. RESULTS: All infected tissues showed large, time-dependent increases in interleukin 1alpha, interleukin 1beta, and interleukin 6. These increases were maximal 13 hours after infection and were highest in uteri (15-60 times levels in uninfected tissues). Increases in tumor necrosis factor alpha and interleukin 1 receptor antagonist were much smaller (3 to 5 times) and were confined to the uterus. Although the uterus contained the greatest concentrations of interleukin 1alpha, interleukin 1beta, interleukin 6, and tumor necrosis factor alpha, fetal bodies and placentas contained the highest levels of interleukin 1 receptor antagonist. CONCLUSIONS: Time-dependent increases in maternal and fetal cytokines occurred after acute bacterial infection in this murine model. The fetus and placenta may be the most significant sources of the anti-inflammatory cytokine interleukin 1 receptor antagonist during pregnancy, whereas the uterus appears to be a more important source of interleukin 1, interleukin 6, and tumor necrosis factor alpha. Interleukin 1 receptor antagonist levels within uteri were insufficiently high to effectively inhibit interleukin 1 activity during infection.

Animals↗

PubMed1999

Mouse laparoscopy.

STUDY OBJECTIVE: To develop a technique for performing laparoscopy in the mouse. DESIGN: Controlled animal study (Canadian Task Force classification II-1). SETTING: University research laboratory. SUBJECTS: Twenty-eight CD-1 pregnant mice. INTERVENTION: Eight mice underwent anesthesia only and 20 had anesthesia plus laparoscopy at 5.5 and at 10.5 days' gestation (implantation occurs on day 4.5 and delivery on days 19-20). MEASUREMENTS AND MAIN RESULTS: Four mice in the laparoscopy group died early in the series, three due to hemorrhage and one due to anesthetic overdose. Among survivors, there were no differences between operated and control groups in number of pups delivered at term (8.7 +/- 5.1 and 8.9 +/- 3.8, respectively), frequency of pregnancy failure (18.8% and 12.5%), and presence of intraabdominal adhesions on autopsy after delivery (12. 5% and 12.5%). Intraabdominal contents could be manipulated to visualize both uterine horns in their entirety. The number of gestations could be counted accurately as early as 1 day after implantation. CONCLUSION: Given the fact that laparoscopy is not accompanied by the immunosuppression characteristic of laparotomy, this technique could prove useful for investigations requiring intraabdominal manipulations in mice when preservation of immune function is critical. The technique can be performed safely and repeatedly after an initial learning period. (J Am Assoc Gynecol Laparosc 6(2):173-177, 1999)

Animals↗

PubMed1999

A comparison of volume and circumference phallometry: response magnitude and method agreement.

Penile circumference and penile volume phallometry are laboratory methods of assessing sexual arousal. Volume phallometry is reportedly more sensitive to responses, but comparative studies have been inconclusive and beset with methodological problems. In this study, 42 self-professed heterosexual volunteers were assessed with both methods simultaneously, employing a standard test for erotic partner preference. Pearson correlations between test outcome profiles were very high (r > .80) for subjects whose circumferential increase was > 2.5 mm [10% of a full erection (FE)]. However, among lower responders the agreement dropped precipitously (mean r = -.15). Moreover, as a group higher responders differentiated adult and pubescent age female stimuli from each other and all other categories with either method, but lower responders made this differentiation only with the volume method. We conclude that (l) at high levels of response both methods are equally good, (2) at low levels of response volumetric phallometry is a more accurate measure of arousal, and (3) 10% FE, or a 2.5-mm circumference increase, should be the minimum response criterion for the circumferential measure.

Adult↗

PubMed1999

Pedophiles: mental retardation, maternal age, and sexual orientation.

Intellectual functioning, parental age, and sexual orientation in 991 male sexual offenders were investigated. Sources of data included semistructured interviews, clinical charts, phallometric tests, and self-administered questionnaires. The results suggest two main conclusions: (i) Among pedophiles in general, erotic preference moves away from adult women along two dimensions: age and sex. The extent of this movement is greater, along both dimensions, for pedophiles with lower levels of intellectual functioning. (ii) High maternal age (or some factor it represents) increases the likelihood of exclusive sexual interest in boys. Intellectual deficiency (or some factor it represents) decreases the likelihood of exclusive sexual interest in girls. These two factors summate, so that a pedophile with both factors is more likely to be sexually interested in boys than a pedophile with only one.

Adult↗

PubMed1998

Discrepant cytogenetic and fluorescence in situ hybridization results in a 26-year-old male with early T-cell acute lymphocytic leukemia.

Analyzable G-banded metaphases were normal in bone marrow from a 26-year-old male having 80% blasts. Fluorescence in situ hybridization (FISH) using the centromeric probe, D7Z1, revealed 85% of interphase cells with one signal for chromosome 7. Chromosome painting revealed a chromosome 7 rearrangement in a few metaphases that were otherwise unanalyzable. A repeat bone marrow confirmed 3 of 20 metaphases, by G-banding, to have multiple rearrangements and aneuploidy, including a large derivative chromosome involving a complex rearrangement of chromosomes 5, 7, and 9; that is, der(5)t(5;9)(q31;q13)ins(5;7)(p15;q?31q?34), with loss of most of chromosome 7 (7 pter-->7q?31); one normal 7 was present. Immunophenotyping characterized the patient's condition as an early T-cell acute lymphocytic leukemia (ALL), with a population of cells suggesting biphenotypic leukemia. He attained a complete clinical remission with chemotherapy. Six months after the initial presentation he received an allogeneic bone marrow transplant. Three months later a CNS relapse was followed by a bone marrow relapse. At this time, eight months after transplant, repeat study of his bone marrow revealed the majority of metaphases had structural and numerical chromosome abnormalities similar to the small clone in the earlier study, including der(5)t(5;9)ins(5;7), but with two normal 7s. FISH showed two 7-centromere signals in interphase. The patient expired one month later.

Adult↗

PubMed1998

Birth order in girls with gender identity disorder.

This study examined the birth order of girls with gender identity disorder (N = 22). Each proband was matched to 3-7 clinical control girls for age at assessment and number of siblings (the mode number of controls per proband was 7) (total N = 147). The number of older brothers, older sisters, younger brothers, and younger sisters was recorded. Slater's birth order index showed that the probands were significantly more likely to be early born than were the controls. A modified Slater's index also compared the birth order of the probands and the controls only to their brothers (when they had one or more) and only to their sisters (when they had one or more). Compared to the controls, the probands were born early compared to their sisters, but not to their brothers. These findings are the inverse of two previous studies of boys with gender identity disorder, who were later born relative to clinical control boys, an effect that appeared to be accounted for primarily by being born later relative to older brothers, but not to older sisters.

Adolescent↗

PubMed1998

The relation of birth order to sexual orientation in men and women.

Homosexual men have a higher mean birth order than do heterosexual men, primarily because they have a greater number of older brothers. The purpose of this study was to determine whether the same difference occurs in homosexual vs heterosexual women. The probands were 964 homosexual and heterosexual, male and female volunteers, from whom birth order data were collected with self-administered questionnaires. The homosexual men had more older brothers than the heterosexual men, but they did not have more older sisters, younger brothers, or younger sisters. The homosexual women did not differ from the heterosexual women with regard to any class of sibling. These results are consistent with the hypothesis that the high birth order of homosexual men reflects the progressive immunization of certain mothers to H-Y antigen by succeeding male fetuses, and the increasing effects of H-Y antibodies on sexual differentiation of the brain in succeeding male fetuses.

Adult↗

PubMed1998

Birth order in homosexual versus heterosexual sex offenders against children, pubescents, and adults.

Homosexual men erotically attracted to physically mature partners typically have more older brothers than comparable heterosexual men. We investigated whether late fraternal birth positions also occur in homosexuals attracted to children or pubescents. Probands were 710 sex offenders from Gebhard et al.'s (1965) study of sexual offending. Homosexual offenders against adults and pubescents had later fraternal birth positions than heterosexual offenders against adults and pubescents, respectively; there was no difference between the homosexual and heterosexual offenders against children. Results provide some evidence that homosexuality in men attracted to immature males is etiologically related to homosexuality in men attracted to mature males.

Adolescent↗

PubMed1998

Birth order and male homosexuality: extension of Slater's index.

Homosexual men tend to be later-born children. Slater's index, the ratio of older sibs to all sibs, is consistently higher for male homosexuals than for comparable heterosexuals. According to some explanations of this tendency, homosexual men are later born with respect to their brothers and later born with respect to their sisters only secondarily and less strongly. We show that if sisters have no direct bearing on a brother's sexual orientation and brothers do, then [formula: see text] On the other hand, if sisters have the same bearing on a brother's sexual orientation as male sibs do, then [formula: see text] These ratios are calculated and compared in nine samples of homosexual men and nine corresponding samples of control heterosexuals. The first equation holds for homosexual men, and the second equation holds for heterosexual men. The late birth order of homosexual men is sex specific. What matters is a boy's birth order relative to his brothers only. This effect may have its origins in an immune reaction or in behavioral contagion.

Analysis of Variance↗

PubMed1997

H-Y antigen and homosexuality in men.

In men, sexual orientation correlates with the number of older brothers, each additional older brother increasing the odds of homosexuality by approximately 33%. It is hypothesized that this fraternal birth order effect reflects the progressive immunization of some mothers to Y-linked minor histocompatibility antigens (H-Y antigen) by each succeeding male fetus, and the concomitantly increasing effects of H-Y antibodies on the sexual differentiation of the brain in each succeeding male fetus. This hypothesis is consistent with a variety of evidence, including the apparent irrelevance of older sisters to the sexual orientation of later-born males, the probable involvement of H-Y antigen in the development of sex-typical traits, and the detrimental effects of immunization of female mice to H-Y antigen on the reproductive performance of subsequent male offspring.

Animals↗

PubMed1997

The relation of closed birth intervals to the sex of the preceding child and the sexual orientation of the succeeding child.

The study investigated whether homosexual men are, on average, born a shorter time after their next-older siblings than are heterosexual men. Because of mixed evidence that birth intervals are longer after a male child, the sex of the next-older sibling was included as a control variable. The probands were 220 heterosexual and 183 homosexual men with at least one older sibling examined in Southern Ontario in 1994-95. These completed a self-administered, anonymous questionnaire concerning their family background and other biodemographic information. The results showed that birth interval was negatively correlated with sibship size, positively correlated with maternal age, and uncorrelated with paternal age. They also confirmed that birth intervals are longer after a male than after a female child. The mean birth intervals preceding heterosexual and homosexual males, however, were virtually identical, indicating that the association of short birth intervals with decreased sex hormone levels in cord blood is unrelated to the development of sexual orientation.

Adolescent↗

PubMed1997

Additive effects of older brothers and homosexual brothers in the prediction of marriage and cohabitation.

Research has shown that male homosexuality tends to cluster in families and that homosexual males have, on average, a greater number of older brothers than do heterosexual males. This study investigated whether the former, between-families effect and the latter, within-families effect are additive. The subjects were 717 full siblings over age 40 reported by 343 heterosexual and homosexual male probands examined in Southern Ontario in 1994-1995. The sibling's history of legal marriage or cohabitation in a heterosexual relationship was taken as a proxy variable for sexual orientation. There were no significant findings for the female siblings. As expected, the never-married male siblings were more likely to come from the sibships of the homosexual probands, and they had a greater average number of older brothers. A bootstrapped logistic regression analysis showed that an additive model best explained the male siblings' data. The results suggest that the familial aggregation of male homosexuality cannot be explained by the birth order effect and that older brothers and family membership reflect separate influences on sexual orientation or sexual orientation-correlated behavior.

Adult↗

PubMed1997

Pedophilia, sexual orientation, and birth order.

This study extended research on birth order and erotic preferences by examining birth order in a sample of pedophiles. Charts of 338 pedophiles, assessed from 1980-1994 in the Behavioural Sexology Department of the Clarke Institute of Psychiatry in Toronto, were reviewed for family-demographic information. In total, 170 (57 heterosexual pedophiles, 68 homosexual pedophiles, and 45 bisexual pedophiles) of these men had sufficient sibling information to be included in the analyses. The results indicated that homosexual-bisexual pedophiles had a later birth order than heterosexual pedophiles and that this effect was primarily the result of the homosexual-bisexual group being born later among their brothers. The results extend previous findings that homosexual men, regardless of sample composition, have a later birth order than comparable groups of heterosexual men. The results also challenge some existing theories on the nature and origins of pedophilia.

Adolescent↗