Quantitative sensory testing in children with sickle cell disease: additional insights and future possibilities.

Quantitative sensory testing (QST) is used in a variety of pain disorders to characterize pain and predict prognosis and response to specific therapies. In this study, we aimed to confirm results in the literature documenting altered QST thresholds in sickle cell disease (SCD) and assess the test-retest reliability of results over time. Fifty-seven SCD and 60 control subjects aged 8-20 years underwent heat and cold detection and pain threshold testing using a Medoc TSAII. Participants were tested at baseline and 3 months; SCD subjects were additionally tested at 6 months. An important facet of our study was the development and use of a novel QST modelling approach, allowing us to model all data together across modalities. We have not demonstrated significant differences in thermal thresholds between subjects with SCD and controls. Thermal thresholds were consistent over a 3- to 6-month period. Subjects on whom hydroxycarbamide (HC) was initiated shortly before or after baseline testing (new HC users) exhibited progressive decreases in thermal sensitivity from baseline to 6 months, suggesting that thermal testing may be sensitive to effective therapy to prevent vasoocclusive pain. These findings inform the use of QST as an endpoint in the evaluation of preventative pain therapies

Cryptorchidism in the orl rat is associated with muscle patterning defects in the fetal gubernaculum and altered hormonal signaling

Cryptorchidism, or undescended testis, is a common male genital anomaly of unclear etiology. Hormonal stimulation of the developing fetal gubernaculum by testicular androgens and insulin-like 3 (INSL3) is required for testicular descent. In studies of the orl fetal rat, one of several reported strains with inherited cryptorchidism, we studied hormone levels, gene expression in intact and hormone-stimulated gubernaculum, and imaging of the developing cremaster muscle facilitated by a tissue clearing protocol to further characterize development of the orl gubernaculum. Abnormal localization of the inverted gubernaculum was visible soon after birth. In the orl fetus, testicular testosterone, gubernacular androgen-responsive transcript levels, and muscle-specific gene expression were reduced. However, the in vitro transcriptional response of the orl gubernaculum to androgen was largely comparable to wild type (wt). In contrast, increases in serum INSL3, gubernacular INSL3-responsive transcript levels, expression of the INSL3 receptor, Rxfp2, and the response of the orl gubernaculum to INSL3 in vitro all suggest enhanced activation of INSL3/RXFP2 signaling in the orl rat. However, DNA sequence analysis did not identify functional variants in orl Insl3. Finally, combined analysis of the present and previous studies of the orl transcriptome confirmed altered expression of muscle and cellular motility genes, and whole mount imaging revealed aberrant muscle pattern formation in the orl fetal gubernaculum. The nature and prevalence of developmental muscle defects in the orl gubernaculum are consistent with the cryptorchid phenotype in this strain. These data suggest impaired androgen and enhanced INSL3 signaling in the orl fetus accompanied by defective cremaster muscle development

The orl Rat with Inherited Cryptorchidism Has Increased Susceptibility to the Testicular Effects of In Utero Dibutyl Phthalate Exposure

Phenotype results from interactions between genetics and environment, but for most environmental chemical exposures, such interactions are theoretical. The phenotypic response of the testis to in utero dibutyl phthalate (DBP) exposure was compared between two strains of Long-Evans (LE) rats, the orl substrain with inherited cryptorchidism and an outbred (wt) strain. orl and wt LE rats were exposed daily between gestational day (GD) 12 and GD21 to DBP dose levels ranging from 50 to 200 mg/kg by oral gavage and sensitive phthalate testicular end points examined at either GD19, GD21, or postnatal day (PND) 21. At 50 mg/kg DBP, GD19 expression of Cyp17a1, Insl3, and Scarb1 was significantly reduced in orl but not wt testis. At GD21, statistically significant differential strain effects (orl more sensitive than wt) were observed for testicular expression of Scarb1 at 50 and 200 mg/kg DBP and Star at 200 mg/kg DBP. Similarly, DBP exposure disproportionately increased GD21 seminiferous cord diameters and numbers of multinucleated germ cells in the orl strain. At PND21, body weight–corrected testis weights were lowered significantly by DBP exposure at all dose levels in the orl strain but not in wt rats. While the frequency of undescended testes after 200 mg/kg DBP exposure in the orl strain appeared increased, these data were not statistically significant. These results demonstrated enhanced sensitivity of the orl rat to phthalate exposure as compared to its parent strain, a potentially important model of the effects of gene-environment interaction on development of male reproductive malformations

Insulin-Like 3 Exposure of the Fetal Rat Gubernaculum Modulates Expression of Genes Involved in Neural Pathways1

Insulin-like 3 (INSL3) signaling directs fetal gubernacular development and testis descent, but the actions of INSL3 in the gubernaculum are poorly understood. Using microarray gene expression profiling of fetal male rat gubernaculum explants exposed to 10 or 100 nM INSL3, significant changes in expression were identified for approximately 900 genes. Several of the genes showing the largest inductions regulate neuronal development or activity, including Pnoc (34-fold), Nptx2 (9-fold), Nfasc (4-fold), Gfra3 (3-fold), Unc5d (3-fold), and Crlf1 (3-fold). Bioinformatics analysis revealed BMP and WNT signaling pathways and several gene ontologies related to neurogenesis were altered by INSL3. Promoter response elements significantly enriched in the INSL3-regulated gene list included consensus sequences for MYB, REL, ATF2, and TEF transcription factors. Comparing in vivo gene expression profiles of male and female rat fetal gubernaculum showed expression of the Bmp, Wnt, and neurodevelopmental genes induced by INSL3 was higher in males. Using quantitative RT-PCR, the microarray data were confirmed, and the induction of Bmp3, Chrdl2, Crlf1, Nptx2, Pnoc, Wnt4, and Wnt5a mRNA levels were examined over a range of INSL3 concentrations (0.1–100 nM) in male and female gubernaculum. In both sexes, an increasing gene expression response was observed between 0.1 and 10 nM INSL3. These data suggest that INSL3 signaling in the fetal gubernaculum induces morphogenetic programs, including BMP and WNT signaling, and support other rodent data suggesting a role for these pathways in development of the gubernaculum

An assessment of the clinical skills of fourth-year students at four New England medical schools.

This paper describes a collaborative effort among five New England medical schools to assess important clinical skills of fourth-year medical students graduating in the class of 1988; results are presented from the four schools that provided sufficient data. Faculty from each school developed 36 patient cases representing a variety of common ambulatory-care problems. Over the course of a day, each student, on average, interacted with 16 different standardized patients, who were nonphysicians trained to accurately and consistently portray a patient in a simulated clinical setting. The students obtained focused histories, performed relevant physical examinations, and provided the patients with education and counseling. At each school, the performance of a small number of the students fell below standards set by the faculty. These deficiencies were not detected with the evaluation strategies currently being used. Although the use of standardized patients should not substitute for the process of faculty observing students as they interact with real patients, it appears that standardized patients can provide faculty with important information, not readily available from other sources, about students\u27 performances of essential clinical activities and the levels of their clinical skills