Genetic polymorphism of UDP-glucuronosyltransferase 2B7 (UGT2B7) at amino acid 268: ethnic diversity of alleles and potential clinical significance

UGT2B7 catalyses the glucuronidation of a diverse range of drugs, environmental chemicals and endogenous compounds. Hence, coding region polymorphisms of UGT2B7 are potentially of pharmacological, toxicological and physiological significance. Two variant UGT2B7 cDNAs encoding enzymes with either His or Tyr at residue 268 have been isolated. The variants, referred to as UGT2B7*1 and UGT2B7*2, respectively, arise from a C to T transversion at nucleotide 802 of the UGT2B7 coding region. Analysis of genomic DNA from 91 unrelated Caucasians and 84 unrelated Japanese demonstrated the presence of the variant alleles encoding UGT2B7*1 and UGT2B7*2 in both populations. However, while there was an approximately equal distribution of subjects homozygous for each allele in the Caucasian population, subjects homozygous for the UGT2B7*1 allele were over 10-fold more prevalent than UGT2B7*2 homozygotes in Japanese. The frequencies of the UGT2B7*1 and UGT2B7*2 alleles were 0.511 and 0.489, respectively, in Caucasians, and 0.732 and 0.268, respectively, in Japanese. The 95% confidence intervals for the two alleles did not overlap between Caucasians and Japanese. Rates of microsomal androsterone, menthol and morphine (3-position) glucuronidation were determined for genotyped livers from Caucasian donors. Statistically significant inter-genotypic differences were not apparent for any of the three substrates. Although the UGT2B7 polymorphism characterized here is probably not associated with altered enzyme activity, the results highlight the need to consider ethnic variability in assessing the consequences of UGT polymorphisms.

Association between survival after treatment for breast cancer and glutathione S-transferase P1 Ile105Val polymorphism

A glutathione S-transferase (GST) P1 polymorphism results in an amino acid substitution, Ile105Val; the Val-containing enzyme has reduced activity toward alkylating agents. Cancer patients with the variant enzyme may differ in removal of treatment agents and in outcomes of therapy. We evaluated survival according to GSTP1 genotype among women (n = 240) treated for breast cancer. Women with the low-activity Val/Val genotype had better survival. Compared with Ile/Ile, hazard ratios for overall survival were 0.8 (95% confidence interval, 0.5-1.3) for Ile/Val and 0.3 (95% confidence interval, 0.1-1.0) for Val/Val (P for trend = 0.04). Inherited metabolic variability may influence treatment outcomes.

Mechanism and amelioration of recombinant human interleukin-11 (rhIL-11)-induced anemia in healthy subjects

Recombinant human interleukin-11 (rhIL-11), or Neumega rhIL-11 Growth Factor, is a recombinant cytokine that stimulates megakaryocytopoiesis, increases platelet production, and also has shown anti-inflammatory and immune-modulating activity. Mild, reversible anemia was the most common adverse event observed in clinical studies and was demonstrated to be related to hemodilution. The purpose of this study was to examine the renal mechanisms of the rhIL-11-induced volume retention and devise a possible therapeutic intervention to ameliorate this effect. Eighteen healthy volunteers (9 male and 9 female) on a controlled sodium (180 mEq/day) and potassium (120 mEq/day) diet were randomized to one of six treatment sequences in a three-period crossover design. Each subject received 25 micrograms/kg IL-11 s.c. once daily, 25 micrograms/kg IL-11 s.c. once daily + Maxzide-25 twice daily, or placebo for 7 days in a crossover design. There was a 14-day washout period between treatment periods. Renal clearance parameters indicated that mean sodium excretion was decreased compared to placebo within 8 hours after dosing with rhIL-11, with these results reaching statistical significance 8 to 16 hours postdose (p < 0.01). The cumulative sodium excretion (mEq +/- SD) over the 7-day treatment period for each respective treatment group was the following: rhIL-11 = 833 +/- 154, rhIL-11 + Maxzide-25 twice daily = 1114 +/- 178, and placebo = 982 +/- 193 (p < 0.01). Hemoglobin concentration and hematocrit values, used as indicators of hemodilution, decreased in the rhIL-11-treated group as compared to the baseline and placebo groups (p < 0.01). Concurrent dosing with Maxzide-25 twice daily reduced the rhIL-11-associated hemodilution by about 50%.

Recovery of sensibility after digital neurorrhaphy: a clinical investigation of prognostic factors

A multicenter retrospective review of 172 epineural digital nerve repairs using microsurgical techniques was performed. A total of 71 men and 25 women ranged in age from 5 to 64 years (mean age, 33.3 years). Sharp injuries occurred in 55.6% of patients and mild crush occurred in 44.4%. Isolated nerve injuries occurred in only 24.6% of patients. The majority of digital nerve injuries involved other structures: flexor tendons (33.5%), tendons and fractures (9.0%), and fractures (4.2%). Replantations were performed in 18 digits (21.6%) and revascularizations in 7 digits (7.2%). Injury to repair was less than 1 day in 47.8%, 2 to 7 days in 22.6%, 8 to 30 days in 23.3%, and 31 to 300 days in 6.3%. Follow-up averaged 22.2 months (range, 6-77 months). The authors found a significant correlation between age and recovery of sensibility as measured by Weber's two-point discrimination test (p < 0.001). Patients older than 40 years demonstrated significantly poorer recovery of sensibility than patients younger than 40 years. A trend of better sensibility return was noted in the younger age decades (<40) with declining age; however, the intergroup differences were not significant. There was also a significant correlation between severity of injury and recovery of sensibility (p < 0.001). Sharp injuries (8.2 mm) demonstrated significantly improved recovery of sensibility compared with mild crush (10.8 mm). Fractures (11.1 mm), fractures and tendon involvement (11.4 mm), and replantations (11.8 mm) demonstrated significantly diminished recovery of sensibility compared with isolated nerve injuries (7.9 mm), tendon involvement (8.1 mm), and revascularizations (9.3 mm). There did not appear to be any significant difference in recovery of sensibility according to gender, digit involved, radial or ulnar side of digit, median or ulnar nerve distribution, level of injury (except for the metacarpophalangeal joint and the distal palmar crease where most replantations occurred), or time interval from injury to repair. There was a weak negative correlation between length of follow-up and recovery of sensation.

Sensitivity of repeated interdigital web pinching to detect antinociceptive effects of ibuprofen

AIMS

The aim of the current study was to assess the viability of the interdigital web pinch model as a test for analgesic activity in volunteer-based early phase drug development.

METHODS

Pain thresholds and sensitization to a series of four sessions of interdigital web pinching (12 Newtons force) were measured in 26 male volunteers before and 1 and 3 h after oral dosing with ibuprofen (800 mg) or placebo to ibuprofen. Within each time point, the pain thresholds were measured by calculating the average visual analogue scores (VAS) for the first session of pinching (VAS-1). Sensitization to pinching was assessed by calculating the average changes in these scores for the three subsequent sessions of pinching (VAS-2). Moreover, the difference between the VAS score after the first session of pinching and that obtained at the end of the fourth session of pinching was calculated as a secondary endpoint (VAS-3).

RESULTS

Treatment with ibuprofen had no significant effect on VAS-1 at either 1 or 3 h after dosing. However, the mean values of VAS-2 and VAS-3, were significantly reduced (P < 0.05) following treatment with ibuprofen.

CONCLUSIONS

This model has been able to detect an antinociceptive effect with ibuprofen. However, large numbers of subjects were required in order to demonstrate this effect and this feature would restrict the model's utility in early phase clinical trials where small numbers of subjects are normally employed.

Removal of UroLume endoprosthesis: experience of the North American Study Group for detrusor-sphincter dyssynergia application

PURPOSE

We present the experience of the North American UroLume Multicenter Study Group with removal of the UroLume endoprosthesis.

MATERIALS AND METHODS

A total of 160 neurologically impaired patients were enrolled in the North American UroLume Multicenter Study Group for detrusor external sphincter dyssynergia application. Analysis was performed in 2 groups of patients in which the device was removed during insertion and after implantation, respectively.

RESULTS

Device retrieval was required during insertion in 21 patients (13%) mainly due to misplacement or migration in 17. Extraction was done with minimal complications and in all but 2 cases subsequent UroLume implantation was successful. Of 158 men with the device in place 31 (19.6%) required removal. In 34 procedures 44 devices were removed, mainly due to migration. Time from implantation to removal ranged from 4 days to 66 months (mean 22 months). The UroLume was removed en bloc in 20 cases and in parts or wire by wire in 19. The majority of patients had no or minimal complications after extraction. Only 2 patients had serious temporary complications, including bleeding and urethral injury, with no lasting consequences. No malignancy developed as a result of UroLume insertion.

CONCLUSIONS

While there is a potential for urethral injury and bleeding, UroLume endoprosthesis removal is largely a simple procedure with minimal complications and consequences.

Erosion of a fascial sling into the urethra

When synthetic materials are used for the construction of pubovaginal slings, urethral erosions may occur. This complication has not been reported with fascial slings. We present a case of a 34-year-old woman who underwent a pubovaginal sling procedure using rectus fascia. After 10 weeks of urinary retention, urethroscopy identified an erosion of the sling at the midurethra. Surgical revision restored normal voiding without recurrent stress incontinence. Although urethral erosions have been reported with synthetic suburethral slings, this case suggests that erosions can also occur with fascial slings. Careful positioning and minimal tension on the sling arms may minimize this risk.

Loss of differentiation of 4NQO-induced rat malignant oral keratinocytes correlates with metastatic dissemination and is associated with a reduced cellular response to TGF-beta1 and an altered receptor profile

This study examined the metastatic capacity of clonal populations of 4NQO-induced rat malignant oral keratinocytes following orthotopic transplantation to athymic mice. Polygonal and spindle cells formed well-differentiated squamous cell carcinomas (keratin positive and vimentin negative) and undifferentiated spindle cell tumours (keratin negative and vimentin positive), respectively, in almost 100% of animals at the site of inoculation (floor of mouth). Transplantation of 5x 10(6) cells of either cell type at high cell density resulted in approximately 50% of animals forming pulmonary metastases. By contrast, inoculation of 2x 10(6) differentiated polygonal cells resulted in the formation of significantly fewer pulmonary metastases than the undifferentiated spindle cells. A single well-differentiated clone of polygonal cells and 3 of 4 of the undifferentiated spindle cell lines produced comparable levels of TGF-beta1. One undifferentiated spindle cell line expressed significantly more TGF-beta1 and, following transplantation orthotopically, fewer animals formed pulmonary metastases despite the formation of primary tumours in almost all grafted animals, suggesting that TGF-beta1 can act as a tumour suppressor in this cell type. All cell lines produced comparable amounts of TGF-beta2. The clones of polygonal cells were markedly inhibited and the spindle cells were only partially inhibited by exogenous TGF-beta1. Both cell types expressed high-affinity TGF-beta cell surface receptors; the ratio of type I to type II TGF-beta receptors was 1.0:<3.0 in the spindle cells and 1.0:17.9 in the polygonal clone. The results suggest that differentiated rat malignant oral keratinocytes are less aggressive and have a decreased potential to metastasise than their undifferentiated spindle cell counterparts. This may be attributable, in part, to a change in TGF-beta receptor profile leading to the partial loss of response to exogenous TGF-beta1.

The differential impact of training stress and final examination stress on herpesvirus latency at the United States Military Academy at West Point

In this study, we searched for evidence for reactivation of three latent herpesviruses, Epstein-Barr virus (EBV), herpes simplex virus type-1 (HSV-1), and human herpesvirus 6 (HHV-6), in West Point cadets experiencing two different stressors. Blood samples were obtained from cadets before and after a 6-week training period known as "Cadet Basic Training" (CBT), at a baseline prior to final examinations, and then once again during the week of final examinations. Antibody titers to latent HSV-1, EBV, and HHV-6 were determined as a measure of the steady-state expression of latent virus. EBV virus capsid antigen (VCA) IgG antibody titers were unchanged in blood samples obtained prior to and immediately after CBT. However, EBV antibody titers were significantly higher in the blood sample obtained during examination week than in the baseline period before examination; they were also higher than antibody titers before/after CBT. None of the serum samples were positive for EBV VCA IgM antibodies, indicating that the changes in antibody titers to EBV were not associated with recent EBV infections in the class. No significant changes in antibody titers to HSV-1 or HSV-6 were found over the identical time periods, including examination week. Academic stress but not CBT modulated the steady-state expression of latent EBV, resulting in the reactivation of latent virus. The same stressors, however, did not affect the steady-state expression of latent HSV-1 or HSV-6, at least as measured by changes in antibody titers. The data provide additional evidence of the impact of different psychological stressors on the steady-state expression of latent herpesviruses.

Long-term followup of the North American multicenter UroLume trial for the treatment of external detrusor-sphincter dyssynergia

PURPOSE

We determine the long-term efficacy and safety of the UroLume stent as minimally invasive treatment for external detrusor-sphincter dyssynergia in spinal cord injured men.

MATERIALS AND METHODS

A total of 160 spinal cord injured men with a mean age plus or minus standard deviation of 36.3 +/- 12.1 years (range 16 to 74) were prospectively treated with an endoprosthesis at 15 centers as part of the North American UroLume trial for external detrusor-sphincter dyssynergia. Urodynamic parameters, including voiding pressure, residual urine volume and bladder capacity, were compared before treatment and at 1, 2, 3, 4 and 5 years after treatment.

RESULTS

Mean voiding pressure was 75.1 +/- 28.2 cm. water before treatment in the 160 patients, and 37.4 +/- 23.9 at year 1 in 97, 39.5 +/- 22.2 at year 2 in 84, 42.6 +/- 27.3 at year 3 in 61, 46.3 +/- 33.2 at year 4 in 57 and 44.2 +/- 28.9 cm. at year 5 in 41 after stent insertion (p <0.001). Residual urine volume decreased after stent placement and was maintained throughout the 5-year followup (p <0.001). Mean cystometric capacity remained constant from 269 +/- 155 before insertion to 337 +/- 182 ml. 5 years later (p = 0.17). Hydronephrosis and autonomic dysreflexia improved or stabilized in most patients with functioning stents. Stent explant was necessary in 24 patients (15%), of whom 4 (16.7%) had another stent implanted.

CONCLUSIONS

The UroLume stent demonstrates long-term safety and efficacy for the treatment of external detrusor-sphincter dyssynergia. The outcome was similar in men with and without previous sphincterotomy.

Genetic polymorphisms in catechol-O-methyltransferase, menopausal status, and breast cancer risk

Polymorphic catechol-O-methyltransferase (COMT) catalyzes the O-methylation of estrogen catechols. In a case-control study, we evaluated the association of the low-activity allele (COMT(Met)) with breast cancer risk. Compared to women with COMT(Val/Val), COMT(Met/Met) was associated with an increased risk among premenopausal women [odds ratio (OR), 2.1; confidence interval (CI), 1.4-4.3] but was inversely associated with postmenopausal risk (OR, 0.4; CI, 0.2-0.7). The association of risk with at least one low-activity COMT(Met) allele was strongest among the heaviest premenopausal women (OR, 5.7; CI, 1.1-30.1) and among the leanest postmenopausal women (OR, 0.3; CI, 0.1-0.7), suggesting that COMT, mediated by body mass index, may be playing differential roles in human breast carcinogenesis, dependent upon menopausal status.

Destructible Toys as Enrichment for Captive Chimpanzees

The use of destructible objects or toys as enrichment for nonhuman primates has had promising results in terms of increased use and positive behavioral effect. The purpose of this project was to determine the use and durability of a number of inexpensive, destructible toys provided one at a time or several at once. Nine singly caged chimpanzees were provided with 8 different toys made of plastic, vinyl, or cloth, and the frequency of use of the toys was determined during 15 min trials 2 times per day. A toy was removed when it was destroyed or when it was not contacted during 4 trials. The chimpanzees contacted the toys an average of 11 times per trial, and the use of the individual toys was significantly higher when provided 1 at a time rather than all at once. Use of the toys was fairly stable over time, and the toys remained in the cages an average of 3.2 days. The durability of the toys was related to the type of toy (e.g., more flexible cloth and vinyl toys lasted longer than rigid plastic toys). The destructible toys were used significantly more often than other permanent cage toys or televisions. Toy use was not related to age, level of abnormal behavior, or use of existing permanent toys or television. The implications of the results were related to the management of an environmental enrichment program and indicated that the provision of flexible, inexpensive toys 1 at a time can be an effective method of enrichment for captive chimpanzees.

Symptomatic improvement of premenstrual dysphoric disorder with sertraline treatment. A randomized controlled trial. Sertraline Premenstrual Dysphoric Collaborative Study Group

CONTEXT

Premenstrual dysphoric disorder is an important cause of symptoms and functional impairment in menstruating women.

OBJECTIVE

To evaluate the efficacy of sertraline hydrochloride for treatment of premenstrual dysphoria by measuring changes in symptom expression and functional impairment.

DESIGN

Two screening cycles followed by 1 single-blind placebo cycle and 3 cycles of randomized, double-blind, placebo treatment.

SETTING

Twelve university-affiliated outpatient psychiatry and gynecology clinics.

PATIENTS

Of the 447 women who requested participation, 243 met criteria for premenstrual dysphoric disorder and were randomized; 200 women completed the study.

INTERVENTION

A flexible (50-150 mg) daily dose of sertraline hydrochloride.

MAIN OUTCOME MEASURES

The Daily Record of Severity of Problems, Hamilton Rating Scale for Depression, Clinical Global Impression Scale, and Social Adjustment Scale.

RESULTS

Mean (+/-SD) total daily symptom scores decreased significantly (P<.001) in the sertraline-treated (64+/-22 to 44+/-19) compared with the placebo-treated (62+/-22 to 54+/-24) groups. Significant improvement (P<.05) was found for all clinically derived symptom clusters (depressive, physical, and anger/irritability symptoms). Hamilton Rating Scale for Depression scores decreased by 44% and 29% in the sertraline and placebo groups, respectively (P<.002). End-point global ratings showed much or very much improvement in 62% of the active treatment group and 34% of the placebo treatment group (P<.001). Reported functional impairment was substantial at baseline. Improvement in psychosocial functioning with treatment was similar to what is found in studies of major depression.

CONCLUSIONS

Sertraline was significantly better than placebo for treatment of premenstrual dysphoria as reflected by symptomatic improvement and change in reported functional impairment. Serotonin reuptake inhibitors such as sertraline are useful therapeutic options for women with premenstrual dysphoria.

Oxidative stress in diabetic macrovascular disease: does homocysteine play a role?

BACKGROUND

Non-insulin-dependent diabetes mellitus (NIDDM) and hyperhomocysteinemia are both associated with increased lipid peroxidation (oxidative stress). This may contribute to the accelerated vascular disease associated with these conditions. It is not known whether the coexistence of elevated homocysteine levels will stimulate oxidative stress further than that caused by diabetes alone.

METHODS

Plasma concentrations of thiobarbituric acid reactive substances (TBARS), an index of lipid peroxidation, were measured in patients with NIDDM who had previously had a methionine load test; some of the patients had hyperhomocysteinemia.

RESULTS

Plasma TBARS concentrations were elevated in diabetics with vascular disease. The additional presence of hyperhomocysteinemia was not associated with a further increase in plasma TBARS concentrations.

CONCLUSIONS

Lipid peroxidation is increased in patients with diabetes mellitus and macrovascular disease and is not further elevated by the coexistence of elevated homocysteine levels. It is possible that diabetes maximally stimulates oxidative stress and any further acceleration of vascular disease in patients who have coexistent hyperhomocysteinemia is mediated through mechanisms other than lipid peroxidation.

The mitogenic effect of KGF and the expression of its cell surface receptor on cultured normal and malignant human oral keratinocytes and on contiguous fibroblasts

This study examined the mitogenic response to keratinocyte growth factor (KGF) of normal and tumour-derived human oral keratinocytes in which the degree of cellular differentiation was known and in contiguous fibroblast cultures derived from the malignant epithelial cultures. Keratinocytes, but not fibroblasts, were stimulated by KGF, thereby demonstrating epithelial target cell specificity of the ligand. KGF-induced stimulation of the tumour-derived keratinocytes cultured in the absence of the 3T3 fibroblast support broadly correlated with the degree of cellular differentiation; well-differentiated keratinocytes were stimulated more by KGF than their less differentiated counterparts. Malignant oral keratinocytes expressed KGF cell surface receptors (KD 451-709 pM; receptors/cell 2306-13645), but KGF receptor mRNA did not correlate with either KGF-induced mitogenesis or the degree of epithelial cell differentiation. When the tumour-derived keratinocytes were cultured in the presence of 3T3 fibroblasts, the mitogenic response to KGF was comparable to normal epithelial cells. The results suggest that KGF-mediated growth stimulation may not be significant in providing a selective advantage for the growth of malignant keratinocytes.

Neandertal DNA sequences and the origin of modern humans

DNA was extracted from the Neandertal-type specimen found in 1856 in western Germany. By sequencing clones from short overlapping PCR products, a hitherto unknown mitochondrial (mt) DNA sequence was determined. Multiple controls indicate that this sequence is endogenous to the fossil. Sequence comparisons with human mtDNA sequences, as well as phylogenetic analyses, show that the Neandertal sequence falls outside the variation of modern humans. Furthermore, the age of the common ancestor of the Neandertal and modern human mtDNAs is estimated to be four times greater than that of the common ancestor of human mtDNAs. This suggests that Neandertals went extinct without contributing mtDNA to modern humans.

Differential nitric oxide production by microvascular and macrovascular endothelial cells

Phenotypic heterogeneity among endothelial cell populations may account for important organ-specific behaviors. Experimental evidence suggests that endothelium-derived nitric oxide mediates certain of these unique responses. The purpose of these investigations was to compare rat pulmonary microvascular endothelial cells with pulmonary artery and aortic macrovascular endothelial cells in their ability to generate nitric oxide (NO). Cultures of these microvascular and macrovascular endothelial cells were incubated with interferon-gamma (IFN-gamma), tumor necrosis factor-alpha (TNF-alpha), and Salmonella typhimurium lipopolysaccharide (LPS) alone or in combination, and nitrite production was measured. Single-agent exposure with IFN-gamma (up to 1,000 U/ml), TNF-alpha (up to 60,000 U/ml), or LPS (up to 500 ng/ml) had little effect on nitrite generation. Nitrite production by rat aortic macrovascular endothelial cells (RAEC) was significantly greater than that by the rat lung microvascular endothelial cells (RLMVEC) when stimulated with TNF-alpha + IFN-gamma, LPS + IFN-gamma, or TNF-alpha + LPS. The maximal response by all endothelial cell types (approximately 15-fold increase in RAEC and 8-fold increase in RLMVEC) was observed with LPS + IFN-gamma. The nitrite generation from rat pulmonary artery endothelial cells was intermediate between RAEC and RLMVEC responses when stimulated with IFN-gamma + LPS or TNF-alpha. Similar patterns of heterogeneous inducible nitric oxide synthase mRNA induction occurred when Northern analysis of specimens from the cultured endothelial cell types was done. These data suggest that phenotypic heterogeneity between these endothelial cell populations is substantial and, by inference, that site-specific NO. generation may occur.