Relationship between growth arrest and autophagy in midgut programmed cell death in Drosophila.

Autophagy has been implicated in both cell survival and programmed cell death (PCD), and this may explain the apparently complex role of this catabolic process in tumourigenesis. Our previous studies have shown that caspases have little influence on Drosophila larval midgut PCD, whereas inhibition of autophagy severely delays midgut removal. To assess upstream signals that regulate autophagy and larval midgut degradation, we have examined the requirement of growth signalling pathways. Inhibition of the class I phosphoinositide-3-kinase (PI3K) pathway prevents midgut growth, whereas ectopic PI3K and Ras signalling results in larger cells with decreased autophagy and delayed midgut degradation. Furthermore, premature induction of autophagy is sufficient to induce early midgut degradation. These data indicate that autophagy and the growth regulatory pathways have an important relationship during midgut PCD. Despite the roles of autophagy in both survival and death, our findings suggest that autophagy induction occurs in response to similar signals in both scenarios.

Analysis of trends in water quality: constructed wetlands in metropolitan Taipei.

Meandering through the most densely populated metropolitan areas of Taipei, Taiwan, the Danshui River and its tributaries have undergone the construction of 14 wetlands since 2004, as a means to improve water quality. This study was conducted to examine the functional capabilities associated with treating non-point source pollution through these riparian wetlands. Trend analysis was used to differentiate dissolved oxygen, biochemical oxygen demand, suspended solids, ammonia, and Escherichia coli, among 13 sampling sites using both functions of a Mann-Kendall test and a seasonal Mann-Kendall test. The results show that water quality in Taipei metropolitan rivers has been improving since increasing the number of constructed wetlands and connecting households to the public sewage system. The concentration of pollutants such as those influencing biochemical oxygen demand have gradually declined in drought seasons because riparian wetlands contribute a base flow to dilute riverine pollutants. This paper indicates that the creation of treatment systems influences dissolved oxygen conditions at the municipal scale, suggesting that constructed wetlands could stabilize water quality during extreme hydrological events and improve water quality particularly in times of drought.

Effects of valproic acid on organic acid metabolism in children: a metabolic profiling study.

Young children are at increased risk for valproic acid (VPA) hepatotoxicity. Urinary organic acid profiles, as a surrogate of mitochondrial function, were obtained in children 1.9 to 17.3 years of age (n = 52) who were undergoing treatment with VPA for seizure disorders. Age-matched patients receiving treatment with carbamazepine (CBZ; n = 50) and healthy children not undergoing treatment (n = 22) served as controls. Age-related changes in organic acid profiles were observed in all three groups. Although the untreated and CBZ control groups were indistinguishable from each other with respect to the principal-component analysis (PCA) score plots of the subjects, a distinct boundary was apparent between the VPA and each of the control groups. Interindividual variability was observed in the VPA-induced alterations in endogenous pathways corresponding to branched-chain amino acid metabolism and oxidative stress. The data suggest that more detailed metabolomic analysis may provide novel insights into biological mechanisms and predictive biomarkers for children at highest risk for serious toxicity.

CYP1B1 expression in rat testis and Leydig cells is not inducible by aryl hydrocarbon receptor agonists.

1. Cytochrome P450 1B1 (CYP1B1) is highly expressed in testis, but there is conflicting information regarding the inducibility of testicular CYP1B1 by aryl hydrocarbon receptor (AhR) agonists. 2. To assess AhR-mediated regulation, testicular CYP1B1 expression was measured following treatment of adult rats with 3-methylcholanthrene and various dosages of benzo[a]pyrene and 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). The effect of TCDD on CYP1B1 expression in R2C rat Leydig and MA-10 mouse Leydig cells in culture was also determined. 3. Immunoblot analysis showed that treatment with benzo[a]pyrene at dosages up to 200 mg/kg/day and 3-methylcholanthrene at 25 mg/kg/day did not induce testicular CYP1B1 expression. Treatment with TCDD at dosages of 1, 5 or 100 microg/kg had no effect, but testicular CYP1B1 protein levels were increased by approximately 50% at dosages of 10 and 50 microg/kg. 4. CYP1B1 mRNA levels in MA-10 and CYP1B1 protein levels in R2C cells were not induced by exposure to TCDD (10-1000 nM). 5. Overall, the results indicate that rodent testicular CYP1B1 is not inducible by AhR agonists.

Wear-pattern analysis in retrieved tibial inserts of mobile-bearing and fixed-bearing total knee prostheses.

Components from 73 failed knee replacements (TKRs) consisting of rotating-platform, mobile-bearing and fixed-bearing implants were examined to assess the patterns of wear. The patterns were divided into low-grade (burnishing, abrasion and cold flow) and high-grade (scratching, pitting/metal embedding and delamination) to assess the severity of the wear of polyethylene. The rotating-platform group had a higher incidence of low-grade wear on the upper surface compared with the fixed-bearing group. By contrast, high-grade wear comprising scratching, pitting and third-body embedding was seen on the lower surface. Linear regression analysis showed a significant correlation of the wear scores between the upper and lower surfaces of the tibial insert (R(2) = 0.29, p = 0.04) for the rotating-platform group, but no significant correlation was found for the fixed-bearing counterpart. This suggests that high-grade wear patterns on the upper surface are reduced with the rotating-platform design. However, the incidence of burnishing, pitting/third-body embedding and scratching wear patterns on the lower surface was higher compared with that in the fixed-bearing knee.

Long-term results of Taiwan Pediatric Oncology Group studies 1997 and 2002 for childhood acute lymphoblastic leukemia.

The long-term outcome of 1390 children with acute lymphoblastic leukemia (ALL), treated in two successive clinical trials (Taiwan Pediatric Oncology Group (TPOG)-ALL-97 and TPOG-ALL-2002) between 1997 and 2007, is reported. The event-free survival improved significantly (P=0.0004) over this period, 69.3+/-1.9% in 1997-2001 to 77.4+/-1.7% in 2002-2007. A randomized trial in TPOG-97 testing L-asparaginase versus epidoxorubicin in combination with vincristine and prednisolone for remission induction in standard-risk (SR; low-risk) patients yielded similar outcomes. Another randomized trial, in TPOG-2002, showed that for SR patients, two reinduction courses did not improve long-term outcome over one course. Decreasing use of prophylactic cranial irradiation in the period 1997-2008 was not associated with increased rates of CNS relapse, prompting complete omission of prophylactic cranial irradiation from TPOG protocols, beginning in 2009. Decreased use of etoposide and cranial irradiation likely contributed to the low incidence of second cancers. High-risk B-lineage ALL, T-cell, CD10 negativity, t(9;22), infant, and higher leukocyte count were consistently adverse factors, whereas hyperdiploidy >50 was a consistently favorable factor. Higher leukocyte count and t(9;22) retained prognostic significance in both TPOG-97 and TPOG-2002 by multivariate analysis. Although long-term outcome in TPOG clinical trials is comparable with results being reported worldwide, the persistent strength of certain prognostic variables and the lower frequencies of favorable outcome predictors, such as ETV6-RUNX1 and hyperdiploidy >50, in Taiwanese children warrant renewed effort to cure a higher proportion of patients while preserving their quality of life.

Improved treatment results for childhood acute myeloid leukemia in Taiwan.

To improve treatment results for children with de novo acute myeloid leukemia (AML), we introduced a novel protocol, Taiwan Pediatric Oncology Group-AML-97A, for AML other than acute promyelocytic leukemia (APL), for which modified conventional protocols were used. From January 1, 1997, to December 31, 2002, 141 children younger than 17 years old with de novo AML were enrolled. In total, 117 patients with non-APL AML were treated with induction therapy of idarubicin and cytarabine (Ara-C), postremission therapy with high-dose Ara-C - containing regimens for four monthly courses, and moderate-dose therapy with idarubicin and Ara-C for four monthly courses. The first 19 patients with APL were treated with all-trans retinoic acid, idarubicin and Ara-C, with the remaining five patients receiving all-trans retinoic acid and idarubicin, followed by maintenance therapy for 2 years. Stem cell transplantation was performed in 29 patients in first remission with a similar outcome as chemotherapy alone. The remission rate in the AML-97A study was 90%, the 5-year survival 51 +/- 5.3% (s.e.) and the 5-year event-free survival 50 +/- 4.8%; for APL, these were 100%, 86 +/- 7.0, and 75 +/- 9.8%. For the whole group, the 5-year survival was 57 +/- 4.7% and the 5-year event-free survival 54 +/- 4.4%. The AML-97A regimen was well tolerated.

Fault tolerant control of multivariable processes using auto-tuning PID controller.

Fault tolerant control of dynamic processes is investigated in this paper using an auto-tuning PID controller. A fault tolerant control scheme is proposed composing an auto-tuning PID controller based on an adaptive neural network model. The model is trained online using the extended Kalman filter (EKF) algorithm to learn system post-fault dynamics. Based on this model, the PID controller adjusts its parameters to compensate the effects of the faults, so that the control performance is recovered from degradation. The auto-tuning algorithm for the PID controller is derived with the Lyapunov method and therefore, the model predicted tracking error is guaranteed to converge asymptotically. The method is applied to a simulated two-input two-output continuous stirred tank reactor (CSTR) with various faults, which demonstrate the applicability of the developed scheme to industrial processes.

Role of individual human cytochrome P450 enzymes in the in vitro metabolism of hydromorphone.

1. The aim was to identify the individual human cytochrome P450 (CYP) enzymes responsible for the in vitro N-demethylation of hydromorphone and to determine the potential effect of the inhibition of this metabolic pathway on the formation of other hydromorphone metabolites. 2. Hydromorphone was metabolized to norhydromorphone (apparent Km = 206 - 822 microM, Vmax = 104 - 834 pmol min(-1) mg(-1) protein) and dihydroisomorphine (apparent Km = 62 - 557 microM, Vmax = 17 - 122 pmol min(-1) mg(-1) protein) by human liver microsomes. 5. In pooled human liver microsomes, troleandomycin, ketoconazole and sulfaphenazole reduced norhydromorphone formation by an average of 45, 50 and 25%, respectively, whereas furafylline, quinidine and omeprazole had no effect. In an individual liver microsome sample with a high CYP3A protein content, troleandomycin and ketoconazole inhibited norhydromorphone formation by 80%. 5. The reduction in norhydromorphone formation by troleandomycin and ketoconazole was accompanied by a stimulation in dihydroisomorphine production. Recombinant CYP3A4, CYP3A5, CYP2C9 and CYP2D6, but not CYP1A2, catalysed norhydromorphone formation, whereas none of these enzymes was active in dihydroisomorphine formation. 6. In summary, CYP3A and, to a lesser extent, CYP2C9 catalysed hydromorphone N-demethylation in human liver microsomes. The inhibition of norhydromorphone formation by troleandomycin and ketoconazole resulted in a stimulation of microsomal dihydroisomorphine formation.

Influence of CYP2C9 genotypes on the formation of a hepatotoxic metabolite of valproic acid in human liver microsomes.

The present study investigated the effect of cytochrome P450 2C9 (CYP2C9) genetic polymorphism on the biotransformation of valproic acid (VPA) to its hepatotoxic metabolite, 4-ene-VPA, and compared that to the formation of the inactive 4-OH-VPA and 5-OH-VPA. cDNA-expressed CYP2C9(*)2 and CYP2C9(*)3 variants were less efficient than the CYP2C9(*)1 wild type in catalyzing the formation of these metabolites, as assessed by the ratio of Vmax and apparent Km (in vitro intrinsic clearance). The reduced efficiency by CYP2C9(*)2 was due to a reduced Vmax, whereas, in the case of CYP2C9(*)3, it was the result of increased apparent Km. The formation rates of 4-ene-VPA, 4-OH-VPA, and 5-OH-VPA in human liver microsomes were reduced by 29, 28, and 31%, respectively, in samples with one mutated CYP2C9 allele, and by 61, 73, and 58%, respectively, in samples with two mutated CYP2C9 alleles. Overall, the homozygote and heterozygote CYP2C9(*)2 and CYP2C9(*)3 genotypes may compromise hepatic VPA biotransformation.

Pharmacogenetics: the therapeutic drug monitoring of the future?

Genetic variability in drug response occurs as a result of molecular alterations at the level of drug-metabolising enzymes, drug targets/receptors, and drug transport proteins. In this paper, we discuss the possibility that therapeutic drug monitoring (TDM) in the future will involve not the mere measurement and interpretation of drug concentrations but will include both traditional TDM and pharmacogenetics-oriented TDM. In contrast to traditional TDM, which cannot be performed until after a drug is administered to the patient. pharmacogenetics-oriented TDM can be conducted even before treatment begins. Other advantages of genotyping over traditional TDM include, but are not limited to, the following: (i) it does not require the assumption of steady-state conditions (or patient compliance) for the interpretation of results; (ii) it can often be performed less invasively (with saliva, hair root or buccal swab samples); (iii) it can provide predictive value for multiple drugs [e.g. a number of cytochrome P450 (CYP) 2D6, CYP2C 19 or CYP2C9 substrates] rather than a single drug; (iv) it provides mechanistic, instead of merely descriptive, information; and (v) it is constant over an individual's lifetime (and not influenced by concurrent drug administration, alteration in hormonal levels or disease states). Pharmacogenetic information can be applied a priori for initial dose stratification and identification of cases where certain drugs are simply not effective. However, traditional TDM will still be required for all of the reasons that we use it now. In current clinical practice, pharmacogenetic testing is performed for only a few drugs (e.g. mercaptopurine, thioguanine, azathioprine, trastuzumab and tacrine) and in a limited number of teaching hospitals and specialist academic centres. We propose that other drugs (e.g. warfarin, phenytoin, codeine, oral hypoglycaemics, tricyclic antidepressants, aminoglycosides, digoxin, cyclosporin, cyclophosphamide, ifosfamide, theophylline and clozapine) are potential candidates for pharmacogenetics-oriented TDM. However, prospective studies of phaymacogenetics-oriented TDM must be performed to determine its efficacy and cost effectiveness in optimising therapeutic effects while minimising toxicity. In the future, in addition to targeting a patient's drug concentrations within a therapeutic range, pharmacists are likely to be making dosage recommendations for individual drugs on the basis of the individual patient's genotype. As we enter the era of personalised drug therapy, we will be able to identify not only the best drug to be administered to a particular patient, but also the most effective and safest dosage from the outset of therapy.

Differential inhibition and inactivation of human CYP1 enzymes by trans-resveratrol: evidence for mechanism-based inactivation of CYP1A2.

trans-Resveratrol (3,5,4'-trihydroxy-trans-stilbene) has been reported to confer chemoprotection against 7,12-dimethylbenz[a]anthracene (DMBA)-induced carcinogenicity in a murine model. A potential mechanism for this effect by trans-resveratrol is inhibition of DMBA-bioactivating cytochrome P450 (CYP) enzymes such as CYP1B1, CYP1A1, and CYP1A2. In the present study, we examined in detail the in vitro inhibitory effects of trans-resveratrol on these three human CYP enzymes. trans-Resveratrol decreased 7-ethoxyresorufin O-dealkylation activity catalyzed by human recombinant CYP1B1, CYP1A1, and CYP1A2 in a concentration-dependent manner and by a mixed type of inhibition. This direct inhibition was enzyme-selective, as judged by the differences in the apparent K(i) values (0.8 +/- 0.1 microM, 1.2 +/- 0.1 microM, and 15.5 +/- 1.1 microM for CYP1B1, CYP1A1, and CYP1A2, respectively). Preincubating recombinant CYP1A2 or human liver microsomes with trans-resveratrol and NADPH prior to the initiation of substrate oxidation resulted in a time- and concentration-dependent decrease in catalytic activity. The inactivation of liver microsomal CYP1A2 by trans-resveratrol required NADPH, was not reversible by dialysis, and was not affected by the trapping agents glutathione, N-acetylcysteine, catalase, or superoxide dismutase, but was attenuated by a CYP1A2 substrate, imipramine. Analysis of a panel of individual human liver microsomes showed intersample differences in the response to the in vitro inactivation by trans-resveratrol. In contrast to CYP1A2, CYP1B1 was not subject to inactivation by this compound and the reduction in CYP1A1 activity was time- but not concentration-dependent. In summary, trans-resveratrol differentially inhibited human CYP1 enzymes and this occurred by two distinct mechanisms: direct inhibition (mainly CYP1B1 and CYP1A1) and mechanism-based inactivation (CYP1A2).

Influence of dietary zinc deficiency during development on hepatic CYP2C11, CYP2C12, CYP3A2, CYP3A9, and CYP3A18 expression in postpubertal male rats.

The present study investigated the effect of dietary zinc deficiency during the developmental period on hepatic cytochrome P450 (CYP) expression in postpubertal male rats. Twenty-one-day-old weanling male Wistar rats were randomly assigned to one of the following dietary groups: zinc-adequate (31 mg zinc/kg diet); marginal zinc-deficient (3 mg zinc/kg diet); severe zinc-deficient (1 mg zinc/kg diet); or pair-fed control for either the marginal or severe zinc-deficient group. All rats were killed at 63 days of age. Compared with the corresponding pair-fed controls, marginal zinc deficiency decreased CYP2C11-mediated testosterone 2alpha- and 16alpha-hydroxylase activities by 43 and 42%, respectively, whereas severe zinc deficiency reduced each of these activities by approximately 60%. The decrease in CYP2C11 activity was accompanied by a reduction in CYP2C11 protein and mRNA levels, as assessed by immunoblot and reverse transcription-polymerase chain reaction (RT-PCR) assays, respectively. Additional RT-PCR analysis indicated that severe zinc deficiency decreased CYP3A2 and CYP3A18 mRNA levels by 49 and 43%, respectively, whereas it increased CYP2C12 (253%) and CYP3A9 (238%) mRNA expression. Plasma testosterone concentration was decreased by 67% in the marginal zinc-deficient group when compared with the corresponding pair-fed control group. By comparison, it was below the limit of quantification (0.2 ng/mL) in the severe zinc-deficient rats. Overall, these results indicate that dietary zinc deficiency during the developmental period feminized the hepatic gene expression of the sexually dimorphic CYP2C11, CYP3A2, CYP3A18, CYP2C12, and CYP3A9 in postpubertal male rats.

Effect of exogenous growth hormone on somatic growth, gonadal development, and hepatic CYP2C11 and CYP2C12 expression in prepubertal intact male rats.

The influence of exogenous growth hormone (GH) on pubertal maturation, as assessed by growth, age of preputial separation, testicular development, and hepatic expression of sexually dimorphic cytochrome P450 (CYP) enzymes, was investigated. Treatment of 22-day old prepubertal intact male rats with twice daily subcutaneous (s.c.) injections of rat recombinant GH (0.12 microg/g body weight) for 12 or 21 days did not affect body weight, skeletal growth, or testicular weight. By comparison, GH suppressed hepatic CYP2C1 enzyme activity, protein, and mRNA levels but induced CYP2C12 expression. GH suppressed CYP2C11 expression by approximately 60% in prepubertal rats as compared with 30% in adult rats, whereas it increased CYP2C12 levels to 80% of the normal female levels but had no effect in adult male rats. Twice daily intravenous injections of GH suppressed CYP2C11 only. Increasing the s.c. dose of GH 30-fold produced little or no additional change in CYP2C11 or CYP2C12 expression, whereas it modestly in creased body weight and skeletal growth and reduced testicular weight. Overall, the present study provides the first demonstration that prepubertal administration (22-33 days of age) of GH at a pharmacologically relevant dose (0.12 microg/g twice daily) suppressed hepatic expression of CYP2C11 in 34-day-old intact male rats, suggesting that in this age group the liver is intrinsically responsive to transcription factors involved in the regulation of GH-dependent, sex-specific CYP gene expression. A higher dose (3.6 microg/g) of GH administered during the prepubertal period was required to elicit a modest effect on somatic growth and gonadal development.

A quantitative analysis of purinoceptor expression in human fetal and adult bladders.

PURPOSE: In adults there is evidence that adenosine triphosphate acting at P2X receptors functions as a co-transmitter at vesical smooth muscle. The contractile mechanisms of human fetal bladder have been studied to a limited extent and it remains undetermined whether P2X receptors contribute. We compared the expression of the 7 known P2X receptors in fetal and adult human bladders using a quantitative polymerase chain reaction (PCR) based method. MATERIALS AND METHODS: Real-time quantitative reverse transcriptase-PCR provides a system for the detection and analysis of RNA. Four complete cadaver fetal bladders were obtained at 16 weeks to full-term gestation and divided into a total of 12 segments. Adult bladder samples were obtained from 4 patients requiring bladder biopsy. Total RNA was extracted from each sample and 10 ng. were used for individual PCR reactions. An ABI 7700 machine (PE Applied Biosystems, California) determined expression levels of the 7 P2X genes in total RNA. RESULTS: In adult bladders P2X1 was by far the predominant purinergic receptor at the messenger RNA level. The remaining purinergic receptors were consistently present in the order P2X1 >> P2X4 > P2X7 >> P2X5 > P2X2 >> P2X3 = P2X6 = 0. In fetal bladders the expression of P2X1 transcripts was much lower than in adult bladders, and P2X4 and P2X7 were also present. The rank order of the P2X transcript level was P2X1 = P2X4 > P2X7 >> P2X5 >> P2X2 >> P2X3 = P2X6 = 0. With increasing gestation the P2X receptor transcript level (expression) shifted from the dome to the body of the bladder. CONCLUSIONS: P2X1 is the predominant purinoceptor subtype in adult human bladders, consistent with pharmacological evidence. The fetal expression of all P2X receptor transcripts is much lower than in adults, suggesting that purinergic transmission is of less importance. However, there are also several marked developmental changes in purinoceptor expression in the bladder, in that P2X4 is expressed in developing bladders at relatively high levels. There is also a marked developmental change in the regional distribution of purinoceptors. These changes are likely to reflect the changing role of purinergic transmission in the control of bladder motility during fetal maturation.

A quantitative analysis of purinoceptor expression in the bladders of patients with symptomatic outlet obstruction.

OBJECTIVE: To compare the expression of the seven known P2X receptors in human bladder from male patients with detrusor instability caused by symptomatic bladder outlet obstruction with that from control bladders, using a quantitative reverse transcription-polymerase chain reaction (RT-PCR) method. PATIENTS AND METHODS: Real-time quantitative RT-PCR provides a system for detecting and analysing RNA. Bladder biopsies were obtained from nine patients undergoing prostate surgery and control biopsies were obtained from eight age-matched men undergoing routine bladder endoscopy studies, and who were asymptomatic. Total RNA was extracted from each sample and 10 ng of this used for individual PCR reactions. The expression levels of the seven P2X genes in the total RNA were then determined. RESULTS: In the control bladder, P2X1 was by far the predominant purinergic receptor at the RNA level, the remainder consistently present in the order P2X1 >> P2X4 > P2X2 > P2X7 > P2X5 >> P2X3 = P2X6 = 0. Calponin, a smooth muscle-specific protein, was used as a marker for smooth muscle content. In bladder from symptomatic patients, the P2X1/calponin ratio was greater than that in controls (P = 0.016). There appeared to be no difference in P2X2, but P2X4, P2X5, and P2X7 were all greater in the symptomatic bladder than in the controls, although these differences were not significant. CONCLUSION: P2X1 is the predominant purinoceptor subtype in the human male bladder, consistent with pharmacological evidence. The amount of P2X1 receptor per smooth muscle cell is greater in the obstructed than in control bladder, suggesting an increase in purinergic function in the unstable bladder arising from bladder outlet obstruction.

Effect of trans-resveratrol on 7-benzyloxy-4-trifluoromethylcoumarin O-dealkylation catalyzed by human recombinant CYP3A4 and CYP3A5.

Red wine concentrate has been reported to inhibit the catalytic activity of human recombinant cytochrome P450 (CYP) 3A4. Wine contains many polyphenolic compounds, including trans-resveratrol, which is also available commercially as a nutraceutical product. In the present study, we examined the in vitro effect of trans-resveratrol on human CYP3A catalytic activity by employing recombinant CYP3A4 and CYP3A5 as model enzymes and 7-benzyloxy-4-trifluoromethylcoumarin (BFC) as a CYP3A substrate. Trans-resveratrol inhibited BFC O-dealkylation catalyzed by CYP3A4 and CYP3A5 in a concentration-dependent manner. In each case, the inhibition was noncompetitive, as determined by Lineweaver-Burk and Dixon plots of the enzyme kinetic data. The apparent Ki values (mean +/- SEM) for the inhibition by trans-resveratrol of BFC O-dealkylation catalyzed by CYP3A4 and CYP3A5 were 10.2+/-1.1 microM and 14.7+/-0.3 microM, respectively. Preincubation of trans-resveratrol with NADPH and CYP3A4 or CYP3A5 for 10 or 15 min prior to initiation of substrate oxidation did not enhance the inhibitory effect, suggesting that this compound was not a mechanism-based inactivator of CYP3A4 or CYP3A5 when BFC was used as the substrate. Overall, our study provides the first demonstration that trans-resveratrol inhibits, in vitro, a substrate oxidation reaction catalyzed by human recombinant CYP3A4 and CYP3A5.

Thanatophoric dysplasia type I.

Thanatophoric dysplasia is a sporadic, nearly always lethal congenital skeletal dysplasia. It is characterized by shortening of the limbs, a severely small thorax, macrocephaly, and platyspondyly. There are two major subtypes: a short, curved femur characterizes type I, and a straighter femur with cloverleaf skull characterizes type II. Recently, mutations in the fibroblast growth factor receptor 3 (FGFR-3) gene have been identified in both subtypes, which suggest that thanatophoric dysplasia is a genetically homogenous skeletal disorder. Most affected neonates die of respiratory failure, due to narrow thorax with pulmonary hypoplasia. Antenatal sonographic diagnosis is feasible in the second trimester of pregnancy, but differentiating thanatophoric dysplasia from non-lethal skeletal disorders is very important. At the present time, however, prenatal genetic screening seems unpractical.

Prediction of bone fracture by bone mineral density in Taiwanese.

BACKGROUND AND PURPOSE: This study evaluated whether lumbar spine bone mineral density (BMDL) and the rate of change of BMDL could predict the risk of bone fracture in Taiwanese. METHODS: In 1989, a baseline survey was carried out in Lin-Kou Township. BMDL was measured using dual photon absorptiometry in 404 healthy volunteers. In 1994/95, a second survey was conducted to reexamine the BMDL and fracture history as well as the risk factors associated with fracture in these subjects. Fractures were classified according to the causes of the injury as severe or mild trauma. RESULTS: Of the 404 original examinees, 381 (79%) participated in the second survey. Twenty-six subjects had experienced a total of 32 fracture incidents during their lifetime and 10 subjects had experienced fracture during the observation period. After adjusting for the effect of body mass index, gender, and age, each standard deviation of decrease in BMDL was found to be associated with a significant 2.38-fold increase in the risk of mild trauma fracture, and a BMDL below the fracture threshold was associated with a 3.93-fold increase of fracture risk. Higher BMDL change rates were found in subjects with a history of fracture. CONCLUSION: This study indicates the importance of maintaining the BMDL above the fracture threshold (1 g/cm2). The strategy for fracture prevention should be directed at prevention of age-related bone loss.

Trans-resveratrol modulates the catalytic activity and mRNA expression of the procarcinogen-activating human cytochrome P450 1B1.

The present study was performed to determine if trans-resveratrol (3,5,4'-trihydroxy-trans-stilbene) modulates the catalytic activity and gene expression of cytochrome P450 1B1 (CYP1B1). In vitro, trans-resveratrol decreased human recombinant CYP1B1-catalyzed 7-ethoxyresorufin O-dealkylation activity, with an IC50 value of 1.4 +/- 0.2 microM (mean +/- SEM). Enzyme kinetic analysis indicated that trans-resveratrol inhibited CYP1B1 enzyme activity by a mixed-type inhibition and the apparent Ki was 0.75 +/- 0.06 microM. To determine if trans-resveratrol modulates constitutive CYP1B1 gene expression, cultured MCF-7 human breast carcinoma cells were treated with trans-resveratrol. As indicated by RT-PCR analysis, treatment of MCF-7 cells with 10 microM trans-resveratrol decreased relative CYP1B1 mRNA levels after 5 h, but not after 1.5 or 3 h, of exposure. trans-Resveratrol treatment at 5, 7.5, 10, or 20 microM for 5 h produced a concentration-dependent decrease in CYP1B1 mRNA levels. The extent of suppression was approximately 50% at 20 microM concentration. The suppressive effect was not a consequence of a toxic response to the compound as assessed by a cell proliferation assay. Overall, our novel finding that trans-resveratrol inhibits the catalytic activity and suppresses the constitutive gene expression of CYP1B1 leads to the possibility that this nutraceutical confers protection against toxicity and carcinogenicity induced by compounds that undergo CYP1B1-catalyzed bioactivation.