Citations

Abstract Children with calcium-deficiency rickets may have increased vitamin D requirements and respond differently to vitamin D2 and vitamin D3. Our objective was to compare the metabolism of vitamins D2 and D3 in rachitic and control children. We administered an oral single dose of vitamin D2 or D3 of 1.25 mg to 49 Nigerian children—28 with active rickets and 21 healthy controls. The primary outcome measure was the incremental change in vitamin D metabolites. Baseline serum 25-hydroxyvitamin D [25(OH)D] concentrations ranged from 7 to 24 and 15 to 34 ng/mL in rachitic and control children, respectively (p < .001), whereas baseline 1,25-dihydroxyvitamin D [1,25(OH)2D] values (mean ± SD) were 224 ± 72 and 121 ± 34 pg/mL, respectively (p < .001), and baseline 24,25-dihydroxyvitamin D [24,25(OH)2D] values were 1.13 ± 0.59 and 4.03 ± 1.33 ng/mL, respectively (p < .001). The peak increment in 25(OH)D was on day 3 and was similar with vitamins D2 and D3 in children with rickets (29 ± 17 and 25 ± 11 ng/mL, respectively) and in control children (33 ± 13 and 31 ± 16 ng/mL, respectively). 1,25(OH)2D rose significantly (p < .001) and similarly (p = .18) on day 3 by 166 ± 80 and 209 ± 83 pg/mL after vitamin D2 and D3 administration, respectively, in children with rickets. By contrast, control children had no significant increase in 1,25(OH)2D (19 ± 28 and 16 ± 38 pg/mL after vitamin D2 and D3 administration, respectively). We conclude that in the short term, vitamins D2 and D3 similarly increase serum 25(OH)D concentrations in rachitic and healthy children. A marked increase in 1,25(OH)2D in response to vitamin D distinguishes children with putative dietary calcium-deficiency rickets from healthy children, consistent with increased vitamin D requirements in children with calcium-deficiency rickets. © 2010 American Society for Bone and Mineral Research

Object Obesity as a consequence of management of pediatric craniopharyngioma is a well-described phenomenon related to the degree of hypothalamic involvement. However, weight change and obesity have not been analyzed in adult patients. Therefore, the purpose of this study was 1) to evaluate the pattern of postoperative weight gain related to preoperative body mass index (BMI), 2) determine if postoperative weight gain is an issue in adult patients, and 3) develop an objective MR imaging grading system to predict risk of postoperative weight gain and obesity in adults treated for craniopharyngioma. Methods The authors retrospectively screened 296 patients with known craniopharyngioma for the following inclusion criteria: pathologically confirmed craniopharyngioma, index surgery at the authors' institution, and operative weight and height recorded with at least 3 months of follow-up including body weight measurement. Patients aged 18 years or younger were excluded, yielding 28 cases for analysis. Cases of craniopharyngiomas were compared with age- and sex-matched controls (pituitary adenoma patients) to evaluate the pattern and significance of perioperative weight changes. Results Mean age was 46 ± 17 years at surgery, and 64% of the patients were male. Complete resection was achieved in 71% of cases. There was no correlation of preoperative BMI and postoperative weight gain testing in a linear model. Sixty-one percent and 46% of patients had postoperative weight gains greater than 4 and 9%, respectively. Comparing craniopharyngioma patients (cases) to age- and sex-matched controls, the preoperative BMIs were similar (p = 0.93) between cases (mean 28.9 [95% CI 30.9–26.9]) and controls (mean 29.3 [95% CI 31.9–26.7]). However, there was a trend to a greater mean postoperative weight change (percentage) in cases (10.1%) than in controls (5.6%) (p = 0.24). Hypothalamic T2 signal change and irregular contrast enhancement correlated and predicted higher-grade hypothalamic involvement. Furthermore, they can be used to objectively grade hypothalamic involvement as the authors propose. Progressive hypothalamic involvement correlated with larger postoperative weight gains (p = 0.022); however, hypothalamic involvement did not correlate with preoperative BMI (p = 0.5). Conclusions Postoperative weight gain in adult patients undergoing surgery for craniopharyngioma is a significant problem and correlates with hypothalamic involvement, as it does in pediatric patients. Finally, objective MR imaging criteria can be used to predict risk of postoperative weight gain and aid in grading of hypothalamic involvement.

AbstractBackground: Aging is associated with a decline in incremental LH pulse amplitude, which could be due to decreased GnRH secretion or impaired GnRH action.Hypothesis: Inconsistent published studies of GnRH action in older men may be due to disparate sex-steroid milieus.Facility: This study was conducted at a clinical translational-research unit.Subjects: We studied 16 healthy men (8 young men and 8 older men).Methods: An overnight transdermal testosterone (T) clamp was implemented before randomly ordered injections of 0, 2.5, 10, 25, 250, and 750 ng GnRH on separate days (96 study sessions).Outcomes: LH responses were quantified by variable-waveform deconvolution analysis.Results: The T clamp maintained age-invariant mean concentrations of total, bioavailable, and free T, SHBG, LH, FSH, and prolactin. By two-way analysis of covariance, GnRH dose (P < 0.001) but not age (0.15 ≤ P ≤ 0.83) determined mean, peak, incremental, and pulsatile LH responses. Statistical power (median) was 95, 98, 90, and 99% to detect a 30% or greater age contrast at P ≤ 0.05 in mean, peak, incremental, and pulsatile LH responses, and greater than 99% to detect a 30% or greater age contrast in bioavailable or total T concentrations. Higher GnRH doses (P < 0.001) abbreviated LH secretory bursts in both age groups.Conclusion: In the face of eugonadal concentrations of total, bioavailable, and free T, young and older men exhibit remarkably similar LH responses to a 300-fold dose range of exogenous GnRH. Accordingly, previously reported disparate effects of age on GnRH action may reflect in part age-discrepant sex-steroid milieus.

Patients coinfected with hepatitis C virus (HCV) and HIV undergoing liver transplantation (LT) are at risk of early, aggressive HCV recurrence. This study investigates the use of frequent protocol-driven biopsies to identify HCV recurrence post LT in coinfected patients. Five consecutive HIV/HCV-coinfected patients underwent LT. Liver biopsies were obtained post LT at 1 hour; days 7, 120, and 365; then annually; and as clinically indicated. Stage 2 (Ishak) or higher fibrosis occurred in 4 of the 5 patients by 60, 120, 270, and 365 days. Two patients died of HCV recurrence and liver failure at 6 and 35 months post LT. Three patients survived more than 4 years after LT, 2 having sustained virologic responses to anti-HCV treatment. Another has histologic recurrence not responding to treatment. Hepatitis C virus recurrence can be rapid and aggressive after LT in HIV-coinfected patients. Serial biopsies identify recurrence early, allowing for prompt initiation of treatment.

Background: Cisplatin is primarily used for treatment of ovarian and testicular cancer. Oxaliplatin is the only effective treatment for metastatic colorectal cancer. Both are known to cause dose related, cumulative toxic effects on the peripheral nervous system and thirty to forty percent of cancer patients receiving these agents experience painful peripheral neuropathy. The mechanisms underlying painful platinum-induced neuropathy remain poorly understood. Previous studies have demonstrated important roles for TRPV1, TRPM8, and TRPA1 in inflammation and nerve injury induced pain. Results: In this study, using real-time, reverse transcriptase, polymerase chain reaction (RT-PCR), we analyzed the expression of TRPV1, TRPM8, and TRPA1 induced by cisplatin or oxaliplatin in vitro and in vivo. For in vitro studies, cultured E15 rat dorsal root ganglion (DRG) neurons were treated for up to 48 hours with cisplatin or oxaliplatin. For in vivo studies, trigeminal ganglia (TG) were isolated from mice treated with platinum drugs for three weeks. We show that cisplatin and oxaliplatin-treated DRG neurons had significantly increased in TRPV1, TRPA1, and TRPM8 mRNA expression. TG neurons from cisplatin treated mice had significant increases in TRPV1 and TRPA1 mRNA expression while oxaliplatin strongly induced only TRPA1. Furthermore, compared to the cisplatin-treated wild-type mice, cisplatin-treated TRPV1-null mice developed mechanical allodynia but did not exhibit enhancement of noxious heat- evoked pain responses. Immunohistochemistry studies showed that cisplatin-treated mice had no change in the proportion of the TRPV1 immunopositive TG neurons. Conclusion: These results indicate that TRPV1 and TRPA1 could contribute to the development of thermal hyperalgesia and mechanical allodynia following cisplatin-induced painful neuropathy but that TRPV1 has a crucial role in cisplatin-induced thermal hyperalgesia in vivo.

Abstract Aromatase inhibitors play a prominent role in the management of postmenopausal women with endocrine-sensitive breast cancer, but there is large variability in both efficacy and tolerability. The purpose of our study was to define interindividual variation in anastrozole metabolism and pharmacodynamics among patients treated with the approved daily dose of 1 mg in a standard practice setting as adjuvant therapy for resected early breast cancer. This study was performed in 191 women in whom pretreatment and during anastrozole plasma concentrations of estrone (E1), estradiol (E2), estrone conjugates, androstenedione, and testosterone were determined and correlated with plasma concentrations of anastrozole and anastrozole metabolites. There were large interindividual variations in plasma anastrozole and anastrozole metabolite concentrations, as well as pretreatment and postdrug plasma E1, E2, and E1 conjugate and estrogen precursor (androstenedione and testosterone) concentrations. E1 and E2 concentrations were below the lower limit of quantitation (LLQ) in most patients after anastrozole therapy (83% for both), but those with detectable concentrations had a broad range (1.58–45.2 and 0.635–97.0 pg/mL, respectively). E1 conjugates after anastrozole therapy were above the LLQ in most patients (93%), with wide interpatient variability (3.50–2,990 pg/mL). Two patients seemed to extensively metabolize anastrozole and failed to display substantial decreases in estrogens. Acknowledging the potential factor of variable compliance, our results showed large interindividual variation in anastrozole metabolism and its effect on circulating estrogens in postmenopausal patients. These findings may have implications with regard to efficacy and adverse events and may indicate the need to “individualize” therapy with this drug. Cancer Res; 70(8); 3278–86. ©2010 AACR.

Abstract Inflammatory bowel disease is characterized by chronic inflammation which predisposes to colorectal cancer. The mechanisms by which inflammation promotes tumorigenesis are not fully known. We aimed to investigate the links between colonic inflammation and tumorigenesis via epigenetic gene silencing. Colon cancer specimens were assessed for the expression of DNA methyltransferase-1 (DNMT-1) using immunohistochemistry. Colorectal carcinoma cell lines were assessed for DNMT1 expression, methylcytosine content, promoter methylation, gene expression, and tumorigenesis in response to interleukin (IL)-6. DNMT1 was expressed at higher levels in both the peritumoral stroma and tumor in inflammatory bowel disease–associated cancers compared with sporadic colon cancers. IL-6 treatment of colon cancer cells resulted in an increase in DNMT1 expression, independent of de novo gene expression. IL-6 increased the methylation of promoter regions of genes associated with tumor suppression, adhesion, and apoptosis resistance. Expression of a subset of these genes was downregulated by IL-6, an effect that was prevented by preincubation with 5-azadeoxycytidine, a DNMT1 inhibitor. Anchorage-independent growth and migration of colon cancer cells was also increased by IL-6 in a 5-azadeoxycytidine–sensitive manner. Our results indicate that DNMT-mediated gene silencing may play a role in inflammation-associated colon tumorigenesis. Mol Cancer Res; 8(4); 471–81. ©2010 AACR.