Randomised controlled trial of aspirin and aspirin plus heparin in pregnant women with recurrent miscarriage associated with phospholipid antibodies (or antiphospholipid antibodies)

OBJECTIVE

To determine whether treatment with low dose aspirin and heparin leads to a higher rate of live births than that achieved with low dose aspirin alone in women with a history of recurrent miscarriage associated with phospholipid antibodies (or antiphospholipid antibodies), lupus anticoagulant, and cardiolipin antibodies (or anticardiolipin antibodies).

DESIGN

Randomised controlled trial.

SETTING

Specialist clinic for recurrent miscarriages.

SUBJECTS

90 women (median age 33 (range 22-43)) with a history of recurrent miscarriage (median number 4 (range 3-15)) and persistently positive results for phospholipid antibodies.

INTERVENTION

Either low dose aspirin (75 mg daily) or low dose aspirin and 5000 U of unfractionated heparin subcutaneously 12 hourly. All women started treatment with low dose aspirin when they had a positive urine pregnancy test. Women were randomly allocated an intervention when fetal heart activity was seen on ultrasonography. Treatment was stopped at the time of miscarriage or at 34 weeks' gestation.

MAIN OUTCOME MEASURES

Rate of live births with the two treatments.

RESULTS

There was no significant difference in the two groups in age or the number and gestation of previous miscarriages. The rate of live births with low dose aspirin and heparin was 71% (32/45 pregnancies) and 42% (19/45 pregnancies) with low dose aspirin alone (odds ratio 3.37 (95% confidence interval 1.40 to 8.10)). More than 90% of miscarriages occurred in the first trimester. There was no difference in outcome between the two treatments in pregnancies that advanced beyond 13 weeks' gestation. Twelve of the 51 successful pregnancies (24%) were delivered before 37 weeks' gestation. Women randomly allocated aspirin and heparin had a median decrease in lumbar spine bone density of 5.4% (range -8.6% to 1.7%).

CONCLUSION

Treatment with aspirin and heparin leads to a significantly higher rate of live births in women with a history of recurrent miscarriage associated with phospholipid antibodies than that achieved with aspirin alone.

A meta-analysis on the influence of inflammatory bowel disease on pregnancy

BACKGROUND

Inflammatory bowel disease (IBD) has a typical onset during the peak reproductive years. Evidence of the risk of adverse pregnancy outcomes in IBD is important for the management of pregnancy to assist in its management.

AIM

To provide a clear assessment of risk of adverse outcomes during pregnancy in women with IBD.

DESIGN

The Medline literature was searched to identify studies reporting outcomes of pregnancy in patients with IBD. Random-effect meta-analysis was used to compare outcomes between women with IBD and normal controls.

PATIENTS AND SETTING

A total of 3907 patients with IBD (Crohn's disease 1952 (63%), ulcerative colitis 1113 (36%)) and 320 531 controls were reported in 12 studies that satisfied the inclusion criteria.

RESULTS

For women with IBD, there was a 1.87-fold increase in incidence of prematurity (<37 weeks gestation; 95% CI 1.52 to 2.31; p<0.001) compared with controls. The incidence of low birth weight (<2500 g) was over twice that of normal controls (95% CI 1.38 to 3.19; p<0.001). Women with IBD were 1.5 times more likely to undergo caesarean section (95% CI 1.26 to 1.79; p<0.001), and the risk of congenital abnormalities was found to be 2.37-fold increased (95% CI 1.47 to 3.82; p<0.001).

CONCLUSION

The study has shown a higher incidence of adverse pregnancy outcomes in patients with IBD. Further studies are required to clarify which women are at higher risk, as this was not determined in the present study. This has an effect on the management of patients with IBD during pregnancy, who should be treated as a potentially high-risk group.

Epidemiology and the medical causes of miscarriage

Human reproduction is extraordinarily wasteful. The reasons for this have taxed all of the contributors to this book. As we move into the 21st century it is sobering to reflect on the fact that we have failed to harness the power of the evolving revolution in molecular medical biology to answer the fundamental question: why is the fate of a fertilized egg so hazardous and so unsuccessful? The following account summarizes our limited knowledge of the epidemiology of miscarriage and then moves on to consider some of the medical causes of miscarriage. The contribution of genetic abnormalities to the problem of pregnancy wastage is discussed elsewhere in this volume.

Future pregnancy outcome in unexplained recurrent first trimester miscarriage

The future pregnancy outcome of 201 consecutive women, median age 34 years (range 22-43), with a history of unexplained recurrent first trimester miscarriage (median 3; range 3-13), was studied. All women and their partners had normal peripheral blood karyotypes; none had antiphospholipid antibodies and none hypersecreted luteinizing hormone (LH). No pharmacological treatment was prescribed and early pregnancy supportive care was encouraged. Women aged < or = 30 years had a subsequent miscarriage rate of 25% (14/57) which rose to 52% (13/25) in women aged > or = 40 years (P = 0.02). After three consecutive miscarriages, the risk of miscarriage of the next pregnancy was 29% (34/119) but increased to 53% (9/17) after six or more previous losses (P = 0.04). A past history of a livebirth did not influence the outcome of the next pregnancy. Supportive care in early pregnancy conferred a significant beneficial effect on pregnancy outcome. Of 160 women who attended the early pregnancy clinic, 42 (26%) miscarried in the next pregnancy compared with 21 out of 41 (51%) who did not attend the clinic (P = 0.002). After thorough investigation, women with unexplained recurrent first trimester miscarriage have an excellent pregnancy outcome without pharmacological intervention if offered supportive care alone in the setting of a dedicated miscarriage clinic.

An informative protocol for the investigation of recurrent miscarriage: preliminary experience of 500 consecutive cases

A total of 500 consecutive women (mean age 32.9 years; SD 5 years) presenting with a history of recurrent miscarriages (median 4; range 3-17) were investigated for the presence of antiphospholipid antibodies (APA), polycystic ovaries (PCO), hypersecretion of luteinizing hormone (LH) and chromosome abnormalities in order to detect an underlying cause of their pregnancy losses. All women had details of their previous reproductive history, investigations and treatment documented: 76% of the women had experienced only early pregnancy losses (miscarriage < 13 weeks gestation); 32% had a history of subfertility; and significant parental chromosome rearrangements were present in 3.6% of couples. An ultrasound diagnosis of PCO was made in 56% of women, 58% of whom were demonstrated to hypersecrete LH, based on early morning urinary LH analysis. Circulating APA were found in 14% of women. An underlying cause of recurrent miscarriage--genetic, endocrine or autoimmune--was found in > 50% of couples. Women in the latter two groups are being recruited to randomized treatment trials which are discussed.

Botulinum toxin for achalasia: long-term outcome and predictors of response

BACKGROUND & AIMS

Botulinum toxin injection into the lower esophageal sphincter of patients with achalasia results in effective short-term relief of symptoms. The aims of this study were to examine the long-term outcome of these patients and to determine the predictors of response to this therapy.

METHODS

Thirty-one patients with achalasia treated with botulinum toxin were followed up prospectively for a median duration of 890 days.

RESULTS

Twenty-eight patients improved initially, but only 20 patients had sustained improvement beyond 3 months; the latter patients were classified as responders. The response rate was greater in patients older than 50 years of age (82% vs. 43% in younger patients; P = 0.03) and in patients with vigorous achalasia (100% vs. 52% with classic achalasia; P = 0.03). Duration of illness, previous dilation, and baseline radiological characteristics did not influence outcome. Nineteen responders eventually had relapse after a median duration of 468 days (range, 153 - 840 days). Fifteen of these patients received a second injection with satisfactory results obtained in the majority of patients.

CONCLUSIONS

Botulinum toxin is an effective treatment for achalasia in about two thirds of patients, with a duration of response averaging 1.3 years. Age and type of achalasia seem to be important predictors of response.

A bifunctional gene product involved in two phases of the yeast cell cycle

The cell cycle in Saccharomyces cerevisiae is divided into two distinct phases. Unbudded, mononucleate cells in the G1 phase can react to relevant environmental changes by mating, sporulating, or by entering stationary phase. DNA synthesis and bud initiation occur almost simultaneously and mark 'commitment' to the completion of mitosis. Temperature-sensitive mutations at the cdc28 locus are known to cause arrest in the G1 phase of the cell cycle at the restrictive temperature. Here we show that the cdc28 gene product is also active in post-G1 cell cycle functions, and that a different property of the gene product may be required for each phase of the cycle in which it acts.

Polycystic ovaries and recurrent miscarriage--a reappraisal

The prevalence of polycystic ovaries (PCO) was established amongst 2199 consecutive women (median age 33 years; range 19-46) with a history of recurrent miscarriage (median 3; 3-14). A diagnosis of PCO was made if the ovarian volume was enlarged (>9 ml), there were >/=10 cysts of 2-8 mm in diameter in one plane and there was increased density of the stroma. In a cohort study, the prospective pregnancy outcome of 486 of the women scanned who were antiphospholipid antibody negative and who received no pharmacological treatment during their next pregnancy was studied. The prevalence of PCO was 40.7% (895/2199). The livebirth rate was similar amongst women with PCO (60.9%; 142/233) compared to that amongst women with normal ovarian morphology (58.5%; 148/253; not significant). Neither an elevated serum luteinizing hormone concentration (>10 IU/l) nor an elevated serum testosterone concentration (>3 nmol/l) was associated with an increased miscarriage rate. Polycystic ovarian morphology is not predictive of pregnancy loss amongst ovulatory women with recurrent miscarriage conceiving spontaneously. The search for a specific endocrine abnormality that can divide women with PCO into those with a good and those with a poorer prognosis for a future successful pregnancy continues.

Pregnancy complications in women with recurrent miscarriage associated with antiphospholipid antibodies treated with low dose aspirin and heparin

OBJECTIVE

To study the obstetric course of women with a history of recurrent miscarriage associated with antiphospholipid antibodies, lupus anticoagulant and anticardiolipin antibodies, treated with low dose aspirin and low dose heparin.

DESIGN

Prospective observational study.

SETTING

University based tertiary referral clinic.

POPULATION

One hundred and fifty pregnant women with a history of recurrent miscarriage associated with persistently positive tests for antiphospholipid antibodies.

METHODS

Lupus anticoagulant was detected using the dilute Russell's viper venom time together with a platelet neutralisation procedure. IgG and IgM anticardiolipin antibodies were detected using a standardised enzyme linked immunosorbent assay. An IgG anticardiolipin level > or = 5 per litre units and an IgM anticardiolipin level > or = 3 per litre units was considered positive. Aspirin (75 mg daily) was commenced at the time of a positive pregnancy test and heparin (5000 units subcutaneously 12 hourly, or enoxaparin 20 mg daily) was started when fetal heart activity was demonstrated on ultrasound. Treatment was stopped at the time of miscarriage or at 34 weeks of gestation.

RESULTS

One hundred and seven pregnancies (71%) resulted in a live birth. Forty-one pregnancies (27%) miscarried, the majority in the first trimester. One woman had a stillbirth, and one a premature baby who died in the neonatal period. One pregnancy was terminated for a fetal anomaly. Gestational hypertension complicated 17% (18/108) of ongoing pregnancies and antepartum haemorrhage 7% (8/108). Twenty-six babies (24%) were delivered before 37 weeks of gestation. Fifty women (46%) were delivered by caesarean section. The median birthweight of all live born infants was 3069 g (range 531-4300); however 15% (16/108) of the infants were small for gestational age.

CONCLUSION

Combination treatment with aspirin and heparin leads to a high live birth rate among women with recurrent miscarriage and antiphospholipid antibodies. However, successful pregnancies are prone to a high risk of complications during all trimesters. Close antenatal surveillance and planned delivery of these pregnancies in a unit with specialist obstetric and neonatal intensive care facilities are indicated.

Defective endovascular trophoblast invasion in primary antiphospholipid antibody syndrome-associated early pregnancy failure

BACKGROUND

Primary antiphospholipid antibody syndrome (PAPS) is an established cause of recurrent pregnancy loss, traditionally presumed to be due to 'intraplacental thromboses'. This study examines products of conception (POC) from early pregnancy failures to investigate the mechanism of pregnancy loss.

METHODS

POC from patients attending a recurrent miscarriage clinic and from terminations of pregnancy for non-medical reasons were examined histologically with particular regard to the presence or absence of vascular or intervillous thromboses and decidual endovascular trophoblast invasion.

RESULTS

There were 31 PAPS-positive, 50 PAPS-negative, 34 aneuploid and 20 control cases at 6-14 weeks gestation. Villous morphology and frequency of intervillous thrombosis were not different among groups. Normal intradecidual endovascular trophoblast invasion was identified significantly less frequently in PAPS+ cases (24%), compared with controls (75%), aneuploid (53%), or PAPS- cases (61%; Z = -3.0, P < 0.01). In all cases there was apparently normal interstitial extravillous trophoblast invasion.

CONCLUSIONS

Defective decidual endovascular trophoblast invasion, rather than excessive intervillous thrombosis, is the most frequent histological abnormality in PAPS+ associated early pregnancy loss. Furthermore, endovascular trophoblast invasion is not significantly reduced in the majority of fetal aneuploidy-associated pregnancy failures.

Regulatory circuit for responses of nitrogen catabolic gene expression to the GLN3 and DAL80 proteins and nitrogen catabolite repression in Saccharomyces cerevisiae

We demonstrate that expression of the UGA1, CAN1, GAP1, PUT1, PUT2, PUT4, and DAL4 genes is sensitive to nitrogen catabolite repression. The expression of all these genes, with the exception of UGA1 and PUT2, also required a functional GLN3 protein. In addition, GLN3 protein was required for expression of the DAL1, DAL2, DAL7, GDH1, and GDH2 genes. The UGA1, CAN1, GAP1, and DAL4 genes markedly increased their expression when the DAL80 locus, encoding a negative regulatory element, was disrupted. Expression of the GDH1, PUT1, PUT2, and PUT4 genes also responded to DAL80 disruption, but much more modestly. Expression of GLN1 and GDH2 exhibited parallel responses to the provision of asparagine and glutamine as nitrogen sources but did not follow the regulatory responses noted above for the nitrogen catabolic genes such as DAL5. Steady-state mRNA levels of both genes did not significantly decrease when glutamine was provided as nitrogen source but were lowered by the provision of asparagine. They also did not respond to disruption of DAL80.

Gat1p, a GATA family protein whose production is sensitive to nitrogen catabolite repression, participates in transcriptional activation of nitrogen-catabolic genes in Saccharomyces cerevisiae

Saccharomyces cerevisiae cells selectively use nitrogen sources in their environment. Nitrogen catabolite repression (NCR) is the basis of this selectivity. Until recently NCR was thought to be accomplished exclusively through the negative regulation of Gln3p function by Ure2p. The demonstration that NCR-sensitive expression of multiple nitrogen-catabolic genes occurs in a gln3 delta ure2 delta dal80::hisG triple mutant indicated that the prevailing view of the nitrogen regulatory circuit was in need of revision; additional components clearly existed. Here we demonstrate that another positive regulator, designated Gat1p, participates in the transcription of NCR-sensitive genes and is able to weakly activate transcription when tethered upstream of a reporter gene devoid of upstream activation sequence elements. Expression of GAT1 is shown to be NCR sensitive, partially Gln3p dependent, and Dal80p regulated. In agreement with this pattern of regulation, we also demonstrate the existence of Gln3p and Dal80p binding sites upstream of GAT1.

Childhood cutaneous tuberculosis: a study over 25 years from northern India

AIMS

We undertook this study to analyse the pattern of childhood cutaneous tuberculosis prevailing in northern India over the past 25 years and to highlight differences from and similarities to adult tuberculosis.

MATERIALS AND METHODS

Clinical records of children with cutaneous tuberculosis who attended the Nehru Hospital attached to the Postgraduate Institute of Medical Education and Research, Chandigarh, India, between January 1975 to December 1999 were analysed.

RESULTS

Four hundred and two patients with cutaneous tuberculosis were examined during the 25-year period of observation. These patients formed 0.1% of the total dermatology outpatients. Seventy-five (18.7%) of these 402 cases were children (</= 16 years). There were 32 (42.7%) boys and 43 (57.3%) girls with a boy : girl ratio of 0.74 : 1. The majority of the children, 41 (54.7%) were in the 10-14 years age group. There was no significant boy or girl preponderance in any group other than in scrofuloderma (SFD), where girls significantly outnumbered boys at all ages. Of the various patterns of cutaneous tuberculosis seen, 40 (53.3%) had SFD, 30 (40.0%) had lupus vulgaris (LV), 3 (4.0%) had tuberculosis verrucosa cutis (TVC), 1 (1.3%) child each had tuberculids and tubercular gumma. No child had a tubercular chancre or acute miliary cutaneous tuberculosis. The neck was the commonest site afflicted with SFD and the face was the commonest site affected with LV. No child had generalized lymphadenopathy. Eighteen (60.0%) of the 30 children with LV had regional lymphadenopathy of which 15 (83.3%) had localized disease and 3 (16.7%) had disseminated disease. Of the 16 children with systemic organ involvement, 12 (75.0%) had regional lymphadenopathy. Of the 62 children in whom the data regarding vaccination status was available, 31 (50.0%) had been vaccinated and 31 (50.0%) had not. Among the vaccinated group no child had disseminated disease. Three (9.7%) children in the nonvaccinated group had disseminated disease. Information regarding Mantoux reactivity was available in 71 (94.7%) children, 61 (86.0%) with localized disease and 10 (14.1%) with disseminated disease. Of the 61 children with localized disease, 56 (91.8%) were Mantoux positive and of the 10 children with disseminated disease, only 5 (50.0%) were Mantoux positive (> 10 mm). Histopathologic reports were available for evaluation in all 75 children. Out of 30 cases of LV, 24 (80%) showed classical tuberculous histology. In contrast, out of 40 cases with SFD, only 19 (47.5%) showed classical histology. Classical tuberculous histology was noted in all 3 (100%) cases of TVC and 1 (100%) case each with tuberculids and gumma. Tubercle bacilli could be demonstrated in 4/30 (13.3%) cases with LV and 9/40 (22.5%) cases with SFD. Systemic involvement was seen in 16 (21.3%) children, of whom 3 (18.8%) had LV and 13 (81.3%) SFD. The lungs were the most common organs involved in 8 (50.0%) children followed by bone(s) in 4 (25.0%), abdomen in 2 (12.5%), and both lung and bone in 1 (6.3%) child. In contrast to adults, girls outnumbered boys in the childhood series; SFD was a common form of presentation in contrast to LV and TVC, tuberculous gumma and tuberculids were noted less often. In both children and adults, Mantoux reactivity did not correlate with the extent of the disease; patients with disseminated disease were found to be less often vaccinated with BCG and regional lymphadenopathy was noted more often in patients with disseminated disease.

CONCLUSIONS

In the whole spectrum of cutaneous tuberculosis, there is a proportion of patients with dissemination (systemic involvement) who are of great epidemiological significance as they require a change in the standard therapeutic regimens recommended for cutaneous tuberculosis.

Development of serine protease inhibitors displaying a multicentered short (<2.3 A) hydrogen bond binding mode: inhibitors of urokinase-type plasminogen activator and factor Xa

Novel scaffolds that bind to serine proteases through a unique network of short hydrogen bonds to the catalytic Ser195 have been developed. The resulting potent serine protease inhibitors were designed from lead molecule 2-(2-hydroxyphenyl)1H-benzoimidazole-5-carboxamidine, 6b, which is known to display several modes of binding. For instance, 6b can recruit zinc and bind in a manner similar to that reported by bis(5-amidino-2-benzimidazolyl)methane (BABIM) (Nature 1998, 391, 608-612).(1) Alternatively, 6b can bind in the absence of zinc through a multicentered network of short (<2.3 A) hydrogen bonds. The lead structure was optimized in the zinc-independent binding mode toward a panel of six human serine proteases to yield optimized inhibitors such as 2-(3-bromo-2-hydroxy-5-methylphenyl)-1H-indole-5-carboxamidine, 22a, and 2-(2-hydroxybiphenyl-3-yl)-1H-indole-5-carboxamidine, 22f. Structure-activity relationships determined that, apart from the amidine function, an indole or benzimidazole and an ortho substituted phenol group were also essential components for optimal potency. The affinities (K(i)) of 22a and 22f, for example, bearing these groups ranged from 8 to 600 nM toward a panel of six human serine proteases. High-resolution crystal structures revealed that the binding mode of these molecules in several of the enzymes was identical to that of 6b and involved short (<2.3 A) hydrogen bonds among the inhibitor hydroxyl oxygen, Ser195, and a water molecule trapped in the oxyanion hole. In summation, novel and potent trypsin-like serine protease inhibitors possessing a unique mode of binding have been discovered.

Cross regulation of four GATA factors that control nitrogen catabolic gene expression in Saccharomyces cerevisiae

Nitrogen catabolic gene expression in Saccharomyces cerevisiae has been reported to be regulated by three GATA family proteins, the positive regulators Gln3p and Gat1p/Nil1p and the negative regulator Dal80p/Uga43p. We show here that a fourth member of the yeast GATA family, the Dal80p homolog Deh1p, also negatively regulates expression of some, but not all, nitrogen catabolic genes, i.e., GAP1, DAL80, and UGA4 expression increases in a deh1 delta mutant. Consistent with Deh1p regulation of these genes is the observation that Deh1p forms specific DNA-protein complexes with GATAA-containing UGA4 and GAP1 promoter fragments in electrophoretic mobility shift assays. Deh1p function is demonstrable, however, only when a repressive nitrogen source such as glutamine is present; deh1 delta mutants exhibit no detectable phenotype with a poor nitrogen source such as proline. Our experiments also demonstrate that GATA factor gene expression is highly regulated by the GATA factors themselves in an interdependent manner. DAL80 expression is Gln3p and Gat1p dependent and Dal80p regulated. Moreover, Gln3p and Dal80p bind to DAL80 promoter fragments. In turn, GAT1 expression is Gln3p dependent and Dal80p regulated but is not autogenously regulated like DAL80. DEH1 expression is largely Gln3p independent, modestly Gat1p dependent, and most highly regulated by Dal80p. Paradoxically, the high-level DEH1 expression observed in a dal80::hisG disruption mutant is highly sensitive to nitrogen catabolite repression.

Factor V Leiden and acquired activated protein C resistance among 1000 women with recurrent miscarriage

Activated protein C (APC) resistance, both in its congenital form, due to the factor V Leiden mutation, and in its acquired form, are important risk factors for systemic venous thrombosis. In view of the suspected thrombotic aetiology of some cases of recurrent miscarriage, the prevalence of APC resistance was determined among 1111 consecutive Caucasian women with a history of either recurrent early miscarriage (three or more consecutive pregnancy losses at <12 weeks gestation; n = 904) or a history of at least one late miscarriage (>12 weeks gestation; n = 207). A control group of 150 parous Caucasian women with no previous history of adverse pregnancy outcome was also studied. Acquired APC resistance was significantly more common among both women with recurrent early miscarriage (8.8%: 80/904; P = 0.02) and those with late miscarriage (8.7%: 18/207; P = 0.04) compared with controls (3.3%: 5/150). In contrast, the frequency of the factor V Leiden allele was similar among (i) women with recurrent early miscarriage (3.3%:60/1808; 58 heterozygotes and one homozygote), (ii) those with late miscarriage (3.9%:16/414; 14 heterozygotes and one homozygote) and (iii) the control group (4.0%:12/300; 12 heterozygotes). Acquired but not congenital APC resistance (due to the factor V Leiden mutation) is associated with both early and late miscarriage.

Does suppressing luteinising hormone secretion reduce the miscarriage rate? Results of a randomised controlled trial

OBJECTIVE

To determine whether prepregnancy pituitary suppression of luteinising hormone secretion with a luteinising hormone releasing hormone analogue improves the outcome of pregnancy in ovulatory women with a history of recurrent miscarriage, polycystic ovaries, and hypersecretion of luteinising hormone.

DESIGN

Randomised controlled trial.

SETTING

Specialist recurrent miscarriage clinic.

SUBJECTS

106 women with a history of three or more consecutive first trimester miscarriages, polycystic ovaries, and hypersecretion of luteinising hormone.

INTERVENTIONS

Women were randomised before conception to receive pituitary suppression with a luteinising hormone releasing hormone analogue followed by low dose ovulation induction and luteal phase progesterone (group 1) or were allowed to ovulate spontaneously and then given luteal phase progesterone alone or luteal phase placebo alone (group 2). No drugs were prescribed in pregnancy.

MAIN OUTCOME MEASURES

Conception and live birth rates over six cycles.

RESULTS

Conception rates in the pituitary suppression and luteal phase support groups were 80% (40/50 women) and 82% (46/56) respectively (NS). Live birth rates were 65% (26/40) and 76% (35/46) respectively (NS). In the luteal phase support group there was no difference in the outcome of pregnancy between women given progesterone and those given placebo pessaries. Live birth rates from an intention to treat analysis were 52% (26/50 pregnancies) in the group given pituitary suppression and 63% (35/56) in the controls (NS).

CONCLUSIONS

Prepregnancy suppression of high luteinising hormone concentrations in ovulatory women with recurrent miscarriage and hypersecretion of luteinising hormone does not improve the outcome of pregnancy. The outcome of pregnancy without pituitary suppression is excellent.

Association of bacterial vaginosis with a history of second trimester miscarriage

The aim of this study was to determine whether bacterial vaginosis (BV) is associated with a history of recurrent pregnancy loss. A total of 500 consecutive patients attending the Recurrent Miscarriage Clinic were screened for the presence of BV. In women who had had at least one late miscarriage BV was found twice as commonly (27/130; 21%) as in women who had had only early losses (31/370; 8%) (P < 0.001). The difference was even larger (26 versus 8%) if women who had had term pregnancies were excluded. Moreover, BV was found three times more commonly in Afro-Caribbean women [17 (29%) of 58] than in Caucasian women [36 (9%) of 379] and, in both groups of women, BV was diagnosed at least twice as frequently in those with a history of at least one late miscarriage than in those who had experienced first trimester pregnancy losses only (P < 0. 001). The condition occurred twice as often among smokers than non-smokers and, in both groups, it was at least twice as common in women with a history of at least one late miscarriage as in those who had had early pregnancy losses only (P < 0.001). However, the relationship between BV and smoking was independent of ethnic origin. Women who douched with chloroxylenol were mostly Afro-Caribbean and had BV more than twice as often as women who did not douche.

Second-trimester pregnancy loss is associated with activated C resistance

We have investigated whether activated protein C resistance (APCR) is associated with second-trimester miscarriage. The prevalence of APCR was significantly higher amongst women with a history of second-trimester miscarriage (10/50; 20%) compared with either women with a history of first-trimester miscarriages only (4/70; 5.7%) or a control group of parous women with no previous history of pregnancy losses (3/70; 4.3%) (P < 0.02). These results suggest that APCR may be an important mechanism of second-trimester pregnancy loss, possibly related to the increase in intravascular coagulation that occurs during pregnancy.

Prospective pregnancy outcome in untreated recurrent miscarriers with thyroid autoantibodies

The purpose of this study was to determine the prevalence of thyroid antibodies in women with recurrent miscarriage and to observe whether their presence was predictive of future pregnancy outcome. A total of 870 consecutive, non-pregnant women with a history of three or more pregnancy losses and normal parental karyotypes were investigated for the presence of thyroglobulin antibodies (TgAb) and for thyroid microsomal antibodies (TmAb). Thyroid antibodies were found in 162 (19%) women. TgAb only were found in eight women (5%); TmAb only in 98 (60%) and both TgAb and TmAb were found in 56 (35%). Thirteen women had a history of thyroid disease and a further 15 women were found to have abnormal thyroid function. All 28 were excluded from the pregnancy outcome study. Among the remaining 134 thyroid antibody positive women, 36 women were not tested and normal thyroid stimulating hormone results were obtained for 98. In the group proven euthyroid, 14 of 24 untreated pregnancies resulted in live births (58%). Among the 710 thyroid antibody negative women, 47 of 81 untreated pregnancies resulted in live births (58%). The future risk of pregnancy loss in women with unexplained recurrent miscarriage is not affected by their thyroid antibody status.

The GLN3 gene product is required for transcriptional activation of allantoin system gene expression in Saccharomyces cerevisiae

We show that mutation at the GLN3 locus results in decreased steady-state levels of DAL7, DUR1,2, CAR1, and URA3 mRNAs derived from cultures grown in the presence of inducer. Basal levels of these RNA species, however, were not significantly affected by a gln3 mutation. The GLN3 product appears to affect gene expression in two ways. The pleiotropic requirement of GLN3 for induced gene expression probably derives from the need of the GLN3 product for inducer uptake into the cell and its loss in gln3 mutants. We also demonstrate that transcriptional activation, mediated by the DAL5 and DAL7 upstream activation sequences, requires a functional GLN3 gene product. This observation identified transcriptional activation as the most likely point of GLN3 participation in the expression of allantoin system genes.

Transcriptional regulation of the DAL5 gene in Saccharomyces cerevisiae

We demonstrate that the DAL5 gene, encoding a necessary component of the allantoate transport system, is constitutively expressed in Saccharomyces cerevisiae. Its relatively high basal level of expression did not increase further upon addition of allantoin pathway intermediates. However, steady-state DAL5 mRNA levels dropped precipitously when a repressive nitrogen source was provided. These control characteristics of DAL5 expression make this gene a good model with which to unravel the mechanism of nitrogen catabolite repression. Its particular advantage relative to other potentially useful genes derives from its lack of control by induction and hence the complicating effects of inducer exclusion.

Synaptic disinhibition during maintenance of long-term potentiation in the CA1 hippocampal subfield

Long-term potentiation (LTP) in the CA1 region of the hippocampus is widely believed to occur through a strengthening of efficacy of excitatory synapses between afferent fibers and pyramidal cells. An alternative mechanism of LTP, reduction of efficacy of synaptic inhibition, was examined in the present report. The present study demonstrates that the maintenance of LTP in the CA1 hippocampal subfield of guinea pigs is accompanied by impairment of type A gamma-aminobutyric acid (GABA) receptor function, particularly at apical dendritic sites of CA1 pyramidal cells. Enhanced excitability of GABAergic interneurons during LTP represents a strengthening of inhibitory efficacy. The net effect of opposite modifications of synaptic inhibition during LTP of CA1 pyramidal cells is an overall impairment of the strength of GABAergic inhibition, and disinhibition could contribute importantly to CA1 pyramidal cell LTP.