Cholestatic pregnancy is associated with reduced placental 11ßHSD2 expression.

INTRODUCTION: Intrahepatic Cholestasis of Pregnancy (ICP) is associated with an increased risk of fetal morbidity and mortality and is characterised by elevated bile acids in the maternal and fetal compartments. Bile acids have been shown to attenuate renal 11ßHSD2 expression and, given the protective role of placental 11ßHSD2 in preventing fetal exposure to excessive maternal cortisol, we aimed to establish whether raised serum bile acids in ICP influence placental 11ßHSD2 expression. METHODS: Placental tissue from human and murine cholestatic pregnancy was evaluated for changes in 11ßHSD2 mRNA expression compared to uncomplicated pregnancy using quantitative PCR. Parallel in vitro studies were performed using BeWo choriocarcinoma cells to assess the effect of different bile acid species on 11ßHSD2 gene expression and whether concurrent UDCA administration can reverse any bile acid induced changes. RESULTS: Placental 11ßHSD2 mRNA expression was reduced in human and murine cholestatic pregnancy. In BeWo cells, treatment with the primary bile acid CDCA resulted in reduced 11ßHSD2 gene expression, while treatment with other primary bile acids had no significant effect. Furthermore, the tertiary bile acid UDCA, used in the treatment of ICP did not significantly affect 11ßHSD2 mRNA levels either alone, or when co-administered with CDCA. DISCUSSION: Under cholestatic conditions placental 11ßHSD2 mRNA is reduced. Studies in BeWo choriocarcinoma cells demonstrated that CDCA is likely to be the specific bile acid that mediates this effect. UDCA, the main bile acid used to treat cholestasis, did not reduce placental 11ßHSD2 expression, further supporting its use in the management of ICP.

Metabolite screening of aromatic amine hair dyes using in vitro hepatic models.

Aromatic amines and heterocyclic amines are widely used ingredients in permanent hair dyes. However, little has been published on their potential for oxidation via hepatic cytochrome P450s. Therefore, the authors screened nine such compounds for their potential to undergo oxidative metabolism in human liver microsomes. Toluene-2,5-diamine (TDA), p-aminophenol, m-aminophenol, p-methylaminophenol, N,N'-bis(2-hydroxyethyl)-p-phenylenediamine, and 1-hydroxyethyl-4,5-diaminopyrazole showed no evidence of oxidative metabolism. Oxidized metabolites of 4-amino-2-hydroxytoluene (AHT), 2-methyl-5- hydroxyethylaminophenol (MHEAP), and phenyl methyl pyrazolone (PMP) were detected, but there was no evidence of beta-nicotinamide adenine dinucleotide phosphate (NADPH)-dependent covalent binding to microsomal protein, suggesting that these are not reactive metabolites. Metabolism of AHT, MHEAP, PMP, and TDA was further studied in human hepatocytes. All these compounds underwent conjugation, but no oxidative metabolites were found. The results suggest that none of the hair dye ingredients tested showed evidence of hepatic metabolism to potentially biologically reactive oxidized metabolites.

The effect of obesity and position on heart rate in pregnancy.

OBJECTIVE: To determine the prevalence of resting sinus tachycardia among pregnant women during routine third-trimester antenatal visits, and to determine the relationship between body mass index (BMI) and heart rate. METHODS: In this cross-sectional study, pregnant women at 32-40 weeks' gestation were evaluated at routine antenatal visits between September 1996 and August 1997. Patients with medical disorders were excluded. Height, weight and pulse in both the sitting and the left lateral recumbent position were obtained. BMI was based on current weight, and those with a BMI of > or = 30 kg/m2 were classified as obese. Sinus tachycardia was defined as a heart rate of > or = 100 beats/min. RESULTS: The prevalence of tachycardia was 39% (n = 93) when seated, and 29% on the left side. The corresponding rates of sinus tachycardia when seated for obese (n = 31) and non-obese (n = 62) pregnant women were 58% and 29% (relative risk 2.0, 95% confidence interval 1.2, 3.3). However, the rates of tachycardia on the left side were not significantly different: 32% for obese and 27% for non-obese (relative risk 1.2, 95% confidence interval 0.6, 2.3). CONCLUSION: Resting tachycardia during routine antenatal visits may be more common than was previously recognized, and the majority of obese pregnant women are tachycardic when seated. When obese women are tachycardic in the seated position their heart rate should be reassessed after 5 min in the left lateral recumbent position.

Drugs in pregnancy. Respiratory disease.

Respiratory illnesses are the commonest cause of patient visits to physicians. Although the common cold, sinusitis and bronchitis may be lacking in drama, they account for a substantial amount of morbidity among women of reproductive age and are frequently encountered by physicians caring for pregnant women. Present knowledge about the management of these common conditions and the safety of the medications often used to treat them are reviewed in this chapter. Asthma and community-acquired pneumonia are more serious respiratory illnesses that are also often encountered in pregnancy. Present evidence suggests that community-acquired pneumonia is best treated empirically, with additional investigation usually necessary only if there is a failure of initial treatment. The recognition of asthma as an inflammatory condition has led to a very specific approach to its management that can readily and safely be applied to the pregnant woman. Treatment of HIV and tuberculosis should not be withheld during pregnancy because of the life-threatening nature of these infections and the importance of preventing vertical transmission.

Pharmacokinetic and pharmacodynamic evaluation of the glycinamide ribonucleotide formyltransferase inhibitor AG2034.

Glycinamide ribonucleotide formyltransferase (GARFT) is a component of the de novo purine synthesis pathway. AG2034 is a specific inhibitor of GARFT that was designed based on the GARFT crystal structure. In conjunction with Phase I studies at four clinical centers in the United States and United Kingdom, AG2034 pharmacology was evaluated in 54 patients receiving 1-11 mg/m2 AG2034 as a 2-5 min injection. Blood samples were obtained just prior to and 5, 15, 30, and 45 min, and 1, 1.5, 2, 4, 6, 8, 12, 24, 48, 72, and 96 h after bolus injection during course 1. Limited sampling was also performed on course 3. Plasma AG2034 was measured using a sensitive and reproducible ELISA assay. AG2034 demonstrated a trimodal elimination pattern over 24 h, with median half-life (t(1/2))alpha = 8.7 min, t(1/2)beta = 72.6 min, and t(1/2)gamma = 364.2 min. AG2034 systemic clearance ranged from 9.4-144.5 ml/min/m2, and volume of distribution was 1.2-7.6 liters/m2. Course 1 AG2034 area under the concentration versus time curve (AUC) had a linear relationship with dose (r(s) = 0.86). Accumulation of AG2034 was evident, because course 3 AUC was higher than course 1 in 23 of 23 evaluable patients, but was not associated with an increase in erythrocyte AG2034. AG2034 systemic exposure had an impact on toxicity, because course 1 and course 3 AG2034 AUCs were significantly higher for patients with grade III/IV toxicity than patients with less than grade II toxicity (P < 0.001 and P = 0.001 for course 1 and course 3, respectively). This study demonstrates rapid systemic clearance of AG2034 and suggests pharmacokinetic approaches that may minimize patient toxicity and aid the development of this interesting class of anticancer agents.

Cloning and initial characterization of the human DPYD gene promoter.

Dihydropyrimidine dehydrogenase (DPD) is the rate-limiting enzyme in the degradation of pyrimidine bases and pyrimidine-based antimetabolites. Reduced DPD activity is associated with toxicity to 5-fluorouracil (5FU) therapy in cancer patients and with neurological abnormalities in paediatric patients. Although variant DPYD alleles have been identified in DPD-deficient patients, they do not adequately explain polymorphic DPD activity or associated clinical phenotypes in vivo. DPD may be transcriptionally regulated as mRNA levels correlate with activity and are differentially regulated in human tissues. A 1.85 kb 5' flanking region of the human DPYD gene was cloned and has transcriptional activity in cultured cells. Analysis of this 5' flanking region in rhesus and cynomolgus monkeys demonstrated conservation (>96%) between humans and primates. Putative binding sites for ubiquitous and cell-specific factors were identified. A polymorphism that disrupts a putative gamma-interferon response element was identified in a cancer patient with reduced DPD activity and severe 5FU toxicity. Further insight into regulation of DPD expression may identify new avenues for the treatment of clinical problems associated with DPD deficiency.

Teaching internal medicine residents about medical problems in pregnancy.

When they became aware that many of their internal medicine residents were not being routinely exposed to a representative range of medical illnesses in pregnancy, the authors set out to develop and implement a brief practical curriculum on the medical problems of pregnancy. They began with a retrospective chart review of 562 consultations with pregnant women and used their findings to develop nine 15-minute lectures that covered a majority of the concepts essential to the care of the medically compromised pregnant woman. Topics included hypertension in pregnancy, the febrile pregnant woman, and renal disease in pregnancy. The authors also created a learner handout, a teaching script, teaching cases, and a bibliography for each lecture. Residents have responded well to the curriculum, and their mean pre- and posttext scores have shown that the lectures improved their knowledge of obstetric medicine. This brief-lecture format may be adapted to other special topics in residency training and readily integrated into already-crowded training schedules.

Should women with human immunodeficiency virus be delivered by cesarean?

Vertical transmission of human immunodeficiency virus (HIV) accounts for most new pediatric cases in the United States. With the routine use of zidovudine in the antepartum, intrapartum, and postnatal periods, transmission of HIV from mother to infant has decreased significantly during the past 5 years. Most transmission occurs during labor and delivery, so the effect of mode of delivery recently has been investigated. Several studies support cesarean to further reduce infection in newborns. However, those studies are limited by lack of data on concomitant effects of viral load and effects of combined antiretroviral therapy. There also might be increased operative morbidity in this population. Therefore, we suggest caution in establishing cesarean as a standard for delivery of HIV-infected women.

The frequency and distribution of thiopurine methyltransferase alleles in Caucasian and Asian populations.

Thiopurine methyltransferase metabolizes 6-mercaptopurine, thioguanine and azathioprine, thereby regulating cytotoxicity and clinical response to these thiopurine drugs. In healthy Caucasian populations, 89-94% of individuals have high thiopurine methyltransferase activity, 6-11% intermediate and 0.3% low, resulting from genetic polymorphism. Four variant thiopurine methyltransferase alleles were detected in over 80% of individuals with low or intermediate thiopurine methyltransferase activity. The wild-type allele is defined as TPMT*1 and the mutant alleles are TPMT*2 (G238C), TPMT*3A (G460A and A719G), TPMT*3B (G460A) and TPMT*3B (A719G). The frequency of these alleles in different ethnic groups is not well defined. In this study, DNA from 199 British Caucasian, 99 British South West Asian and 192 Chinese individuals was analysed for the presence of these variant alleles using polymerase chain reaction-restriction fragment length polymorphism and allele-specific polymerase chain reaction based assays. The frequency of individuals with a variant thiopurine methyltransferase genotype was: Caucasians 10.1% (20/199), South West Asians 2.0% (2/99) and Chinese 4.7% (9/192). Two TPMT*2 heterozygotes were identified in the Caucasian population, but this allele was not found in the two Asian populations. TPMT*3A was the only mutant allele found in the South West Asians (two heterozygotes). This was also the most common mutant allele in the Caucasians (16 heterozygotes and one homozygote) but was not found in the Chinese. All mutant alleles identified in the Chinese population were TPMT*3C (nine heterozygotes). This allele was found at a low frequency in the Caucasians (one heterozygote). This suggests that A719G is the oldest mutation, with G460A being acquired later to form the TPMT*3A allele in the Caucasian and South West Asian populations. TPMT*2 appears to be a more recent allele, which has only been detected in Caucasians to date. These ethnic differences may be important in the clinical use of thiopurine drugs.

Thiopurine methyltransferase alleles in British and Ghanaian populations.

Thiopurine methyltransferase (TPMT) catalyses the S-methylation of thiopurine drugs such as 6-mercapto-purine, 6-thioguanine and azathioprine. TPMT activity is inherited as an autosomal co-dominant trait, and several mutations in the TPMT gene have been identified which correlate with a low activity phenotype. Although ethnic differences in TPMT activity have been described, population frequency analysis of TPMT alleles has not been well defined in different ethnic groups. The frequency of four allelic variants of the TPMT gene, TPMT*2, TPMT*3A, TPMT*3B and TPMT*3C were compared in British Caucasian (n = 199) and Ghanaian (n = 217) populations using PCR-RFLP and allele-specific PCR-based assays. TPMT*3C was found in 14.8% of Ghanaians (31 heterozygotes, one homozygote). The TPMT*2, TPMT*3A and TPMT*3B alleles were not detected in any of the Ghanaian samples analysed. In contrast, 10.1% of British subjects had variant alleles, consisting of TPMT*2 (n = 2), TPMT*3A (n = 17) and TPMT*3C (n = 1) alleles. The frequencies of mutant alleles in this study were 5.3 and 7.6% in British Caucasians and Ghanaians, respectively. Among Ghanaian tribes, Ewe subjects had a lower frequency of mutant alleles (5.9%) than Ga (13.2%) or Fanti (11.6%), although this did not reach statistical significance. This study provides the first analysis of TPMT mutant allele frequency in an African population and indicates that, unlike Caucasians, TPMT*3C is the most common allele in African subjects.

Ethnic differences in thiopurine methyltransferase pharmacogenetics: evidence for allele specificity in Caucasian and Kenyan individuals.

Thiopurine methyltransferase (TPMT) degrades 6-mercaptopurine, azathioprine and 6-thioguanine which are commonly used in the treatment of autoimmune diseases, leukaemia and organ transplantation. TPMT activity is polymorphic as a result of gene mutations. Heterozygous individuals have an increased risk of haematological toxicity after thiopurine medication, while homozygous mutant individuals suffer life threatening complications. Previous population studies have identified ethnic variations in both phenotype and genotype, but limited information is available within African populations. This study determined the frequency of common TPMT variant alleles in 101 Kenyan individuals and 199 Caucasians. The frequency of mutant alleles was similar between the Caucasian (10.1%) and Kenyan (10.9%) populations. However, all mutant alleles in the Kenyan population were TPMT*3C compared with 4.8% in Caucasians. In contrast TPMT*3A was the most common mutant allele in the Caucasian individuals. This study confirms ethnic differences in the predominant mutant TPMT allele and the findings will be useful for the development of polymerase chain reaction-based strategies to prevent toxicity with thiopurine medications.

Thiopurine methyltransferase genotype predicts therapy-limiting severe toxicity from azathioprine.

BACKGROUND: Substantial hematologic toxicity limits the use of azathioprine. OBJECTIVE: To evaluate 1) polymorphic inactivation of azathioprine by thiopurine methyltransferase and 2) clinical toxicity. DESIGN: Prospective cohort study. SETTING: Two rheumatology units. PATIENTS: 67 patients for whom azathioprine was prescribed as second-line therapy for rheumatic disease. MEASUREMENTS: Polymerase chain reaction-based assays were used to detect mutations in thiopurine methyltransferase. The primary end point was discontinuation of azathioprine therapy because of toxicity. RESULTS: Six of 67 patients (9%) were heterozygous for mutant thiopurine methyltransferase alleles. Five of the 6 patients discontinued therapy within 1 month of starting treatment because of low leukocyte counts. The sixth patient did not adhere to treatment. Patients with wild-type thiopurine methyltransferase alleles received therapy longer than did patients with mutant alleles (median duration of therapy, 39 weeks [range, 6 to 180 weeks] and 2 weeks [range, 2 to 4 weeks], respectively; P = 0.018). CONCLUSION: Analysis of thiopurine methyltransferase genotype is a quick way to identify patients at risk for acute toxicity from azathioprine.

Medical problems during pregnancy.

Dramatic physiologic changes are part of normal human pregnancy. The physiologic alterations of pregnancy have the potential to affect chronic diseases, to unmask subclinical conditions, or to alter the presentation and course of newly acquired illnesses. An update in selected topics of obstetric medicine follows, focusing on clinical entities in which there have been significant advances in diagnosis or management. Additionally, reviews of selected medical disorders, such as HIV infection and asthma, that are rising in incidence in women of reproductive age are included.

Alveolar-arterial oxygen gradient in acute pulmonary embolism in pregnancy.

OBJECTIVE: Our goal was to determine the prevalence of normal alveolar-arterial gradients in pregnant patients with documented pulmonary embolism. STUDY DESIGN: A retrospective chart review was performed on all pregnant women with pulmonary embolism at two large obstetric centers between 1990 and 1995. Alveolar-arterial gradients were calculated from room air arterial blood gas values and compared with values from patients who had been established as normal. RESULTS: Ten of 17 patients with pulmonary embolism identified had alveolar-arterial gradients that were normal. CONCLUSIONS: In our study 58% of pregnant women with documented pulmonary embolism had a normal alveolar-arterial gradient. This markedly differs from the published data in nonpregnant patients, in which the incidence of normal alveolar-arterial gradients in pulmonary embolism has ranged from 1.9% to 20%. This suggests that the alveolar-arterial gradient should not be used to determine the likelihood of pulmonary embolism in pregnant women because this could lead to the withholding of appropriate treatment for this life-threatening condition.

Diabetes insipidus in pregnancy: a treatable cause of oligohydramnios.

BACKGROUND: Diabetes insipidus, which presents with polyuria, polydipsia, and profound electrolyte abnormalities, occurs rarely in pregnancy. We report a patient with severe oligohydramnios that resolved after treatment of diabetes insipidus. CASE: A 14-year-old girl was admitted at 33 weeks' gestation with cramping and vaginal spotting. A sonogram indicated oligohydramnios and an amniotic fluid index (AFI) of 2.6, with normal fetal kidneys and bladder. On hospital day 2, the AFI was 0.0. Recorded fluid was 8 L in and 13.6 L out. Serum sodium was 153 mEq/L. Diabetes insipidus was diagnosed and treated with intranasal desmopressin acetate. The oligohydramnios resolved rapidly, and the patient delivered a healthy 2700-g male infant at 38 weeks. CONCLUSION: Although rare, diabetes insipidus may present initially in pregnancy and should be considered in patients with oligohydramnios. Simple diagnosis with determination of 24-hour urine volume and serum electrolytes can identify this potentially reversible cause of oligohydramnios and poor obstetric outcome.

Continuing medical education in marital and family therapy: a survey of South Australian psychiatrists.

OBJECTIVE: South Australian psychiatrists were surveyed to determine their impressions of the usefulness of marital and family therapy (MFT) in the management of serious psychiatric conditions and to ascertain their previous experience with Continuing Medical Education (CME) about family therapy. It was expected that psychiatrists' preferences regarding CME would be related to their clinical experience of the usefulness of MFT. METHOD: One hundred and twenty psychiatrists returned a questionnaire about their training, clinical and research interests, with ratings of the usefulness of MFT and CME preferences. This represented 65% of those eligible for the CME programme. RESULTS: Thirteen percent of the respondents found MFT to be extremely useful and a further 47% found it moderately useful in their current practice. There was evidence of a possible training effect: respondents who had previous CME rated MFT as more useful, especially for mood disorders. Furthermore, the treatment of mood disorders seemed to have a particular relevance in family psychiatry, making a statistically unique contribution to ratings of MFT usefulness in the respondents' total practice. Sixty-nine percent of the respondents requested further CME in family therapy. This represented 45% of all South Australian psychiatrists. Respondents who rated MFT as more useful in practice were significantly more likely to be interested in CME. CONCLUSIONS: There seems to be sufficient interest and clinical experience among psychiatrists for MFT to be included in CME courses. It is recommended that further training focus on major mental disorders, especially mood disorders and schizophrenia.