An in vivo culture system for human embryos using an encapsulation technology: a pilot study

BACKGROUND

Animal studies have demonstrated better embryo development in vivo than in vitro. This pilot study tested the feasibility of using a novel in utero culture system (IUCS) to obtain normal human fertilization and embryo development.

METHODS

The IUCS device comprised a perforated silicone hollow tube. The study included 13 patients (<36 years) undergoing a first intracytoplasmic sperm injection (ICSI) treatment and 167 metaphase II oocytes in three groups. In Group 1, 1-2 h after ICSI, sibling oocytes were assigned to IUCS or conventional in vitro culture. The device was retrieved on Day 1, and all zygotes were cultured in vitro till Day 5. In Group 2, fertilized oocytes were assigned on Day 1, embryos retrieved on Day 3 and all embryos cultured till Day 5. In Group 3, after Day 0 assignment, embryos were retrieved on Day 3 for blastomere biopsy and fluorescence in situ hybridization (FISH) and cultured until Day 5. The highest quality blastocysts were transferred on Day 5.

RESULTS

Fertilization and embryo development were comparable in the in vitro and IUCS arms, with a tendency towards better embryo quality in the IUCS. FISH analysis in Group 3 revealed more normal embryos using the IUCS (P = 0.049). Three clinical pregnancies and live births were obtained: two from the IUCS arm and one from the in vitro arm.

CONCLUSIONS

Our pilot study shows that this new IUCS appears to be feasible and safe, supporting normal fertilization, embryo development and normal chromosomal segregation. Furthermore, live births are possible after the transient presence of a silicone device in the uterus. Clinicaltrials.gov: NCT00480103.

Effects of human chorionic gonadotropin on trophoblast invasion

Recent studies have shown that different populations of trophoblastic cells of first-trimester human placenta express human chorionic gonadotropin/luteinizing hormone (hCG/LH) receptors. Among these trophoblastic cells, extravillous cytotrophoblasts (CTBs) not only express hCG/LH receptors but also present an invasive phenotype. CTB invasion is instrumental in blastocyst implantation and later in placentation and is tightly regulated in both time and space. This article describes some of the regulators of CTB invasion and summarizes and discusses the potential autocrine/paracrine role of hCG in trophoblast invasion.

HIV seroconversion during pregnancy and risk for mother-to-infant transmission

Pregnant women infected with HIV-1 were enrolled in a prospective mother-to-infant transmission study from 1992 through 1994 in Bangkok. In participating hospitals, voluntary HIV testing was routinely offered at the beginning of antenatal care and again in the middle of the third trimester of pregnancy. Women who seroconverted to HIV during pregnancy were compared with women who had tested positive on their first antenatal test. Maternal HIV RNA levels were determined during pregnancy, at delivery, and postpartum using RNA polymerase chain reaction (PCR), and infection status in infants was determined by DNA PCR. No infants were breast-fed, but prophylactic antiretroviral therapy was not yet used in Thailand to prevent transmission from mother to infant. Among enrolled women, 16 who seroconverted during pregnancy and 279 who were HIV-1-seropositive at their first antenatal test gave birth. Median plasma RNA levels at delivery were similar for the two groups (17,505 and 20,845 copies/ml, respectively; p =.8). Two (13.3%) of 15 infants born to women who seroconverted and 66 (24.8%) of 266 infants born to previously HIV-seropositive women were infected with HIV (p =.5). There was no increased risk for mother-to-infant HIV transmission and no significant difference in viral load at delivery between HIV-infected women who seroconverted to HIV during pregnancy and those who were HIV-seropositive when first tested.

Safety of late in utero exposure to zidovudine in infants born to human immunodeficiency virus-infected mothers: Bangkok. Bangkok Collaborative Perinatal HIV Transmission Study Group

BACKGROUND

Short-course zidovudine (ZDV) given in the late antenatal period can reduce mother-infant human immunodeficiency virus (HIV) transmission by one half. Because this intervention is being implemented in developing countries, evidence of its safety is needed.

METHODS

In a randomized, double-blinded, placebo-controlled trial in Bangkok, HIV-infected pregnant women received either ZDV (300 mg twice daily from 36 weeks' gestation until labor, then every 3 hours until delivery) or an identical placebo regimen. Infants were evaluated at birth and at 1, 2, 4, 6, 9, 12, 15, and 18 months of age. Growth, clinical events, and hematologic and immunologic measurements were compared between treatment groups.

RESULTS

Of the 395 children born (196 in ZDV group and 199 in placebo group), 330 were uninfected, 55 were infected, and 10 had indeterminate infection status. Overall, 319 children (81%) completed 18 months of follow-up, and 14 (4%) died before 18 months of age. Among uninfected children, the mean hematocrit was lower in the ZDV group at birth (49.1% vs 51.5%) but not at later ages; mean weight, height, head circumference, and CD4(+) and CD8(+) T lymphocyte counts were similar in both groups at all ages. Five uninfected children in the ZDV group but only one in the placebo group had a febrile convulsion. No other signs suggestive of mitochondrial dysfunction and no tumors were observed. Among infected children, an estimated 62% in the ZDV group and 77% in the placebo group survived free of Centers for Disease Control and Prevention class C disease during the 18-month follow-up.

CONCLUSIONS

No significant adverse events were associated with short-course ZDV during 18 months of follow-up in this population.

Simultaneous bilateral tubal pregnancy after intracytoplasmic sperm injection treated by conservative medical treatment. Interest of sonographic follow-up

We describe a case of early bilateral tubal pregnancy diagnosed by transvaginal ultrasonography after intracytoplasmic sperm injection (ICSI) and embryo transfer (ET). A follow-up by transvaginal sonography was done with a systematic second scan (5 days) after the first diagnosis of left tubal ectopic pregnancy in case of assisted conception procedure. This follow-up sonographic strategy permitted us to perform a conservative treatment for this case of spontaneous bilateral tubal pregnancy by two consecutive (left then right) in-situ methotrexate injections under vaginal ultrasonographic guidance without any complications.

Choriocarcinoma-like human chorionic gonadotrophin (HCG) and HCG bioactivity during the first trimester of pregnancy

The objective of this study was to evaluate the distribution of choriocarcinoma-like human chorionic gonadotrophin (HCG) isoforms during first trimester pregnancy and their relationship with in-vitro HCG bioactivity. This was done by means of a retrospective analysis of patients' sera with first trimester normal intrauterine and abnormal (ectopic) pregnancies. Serum samples were obtained from 38 women with an amenorrhoea of <10 weeks. From these, 19 had a normal intrauterine pregnancy (IUP) and 19 an ectopic pregnancy (EP). Total immunoreactive HCG (HCGi), free beta-HCGi and oestradiol were measured by enzyme immunoassays and bioactive HCG by the mouse Leydig cell bioassay. The alterations in HCG isoform content were measured by the combination of two immunometric assays, B152 for choriocarcinoma-like HCG and B109 for intact HCG detection and expressed as the B152/B109 ratio. Choriocarcinoma-like HCG isoforms ratio measured by B152 and B109 assays was significantly higher in the low subgroups of free beta-HCGi and gestational age (P = 0.0111 and 0.0036 respectively). Whereas bioactive to immunoreactive HCG ratios (b/i ratio) were significantly higher when free beta-HCGi concentrations were low (P = 0.0010), no correlation was found between the variation of bioactivity (b/i ratio) and the proportion of choriocarcinoma-like HCG isoforms (B159/B108). It is concluded that in first trimester pregnancies (i) the modulation of HCG in-vitro bioactivity is not related to the variation of choriocarcinoma-like HCG isoforms secretion and (ii) the amount of choriocarcinoma-like HCG isoforms secreted by the early trophoblast is predominant and may be the result of an early developmental regulation of glycosylation enzyme.

Expression of pro-EPIL peptides encoded by the insulin-like 4 (INSL4) gene in chromosomally abnormal pregnancies

The recent development of a specific immunoassay based on monoclonal antibodies directed to chain C and chain A of early placenta insulin-like peptide (EPIL) encoded by the INSL4 gene, has made it possible to demonstrate pro-EPIL peptide expression during normal pregnancy. In the present study, we report on the expression of pro-EPIL peptides in chromosomally abnormal pregnancies, namely trisomy 21 and 18. EPIL peptide levels were measured in amniotic fluid (AF) and maternal serum (MS) from pregnancies with trisomy 21 (n=16) or 18 (n=14) and compared to levels detected in AF and MS from 33 chromosomally normal pregnancies between 12 and 32 weeks of gestation. Pro-EPIL peptide levels were significantly higher in amniotic fluids from T21 than in AF from chromosomally normal pregnancies (mean pro-EPIL levels +/- SEM, 449+/-129.2 ng/mL vs 137+/-29.6 ng/mL, P = 0.0195), whereas there was only a trend towards an increase in pro-EPIL peptide levels in maternal serum. In a limited matched gestational age range (15 to 17 weeks), it was confirmed that pro-EPIL peptide levels were significantly higher in AF from T21 pregnancies (644.0+/-155.9 ng/mL, n = 11) than in AF from normal pregnancies (177.8+/-39.0 ng/mL, n = 12; P < 0.0001). Interestingly, the expression patterns of pro-EPIL peptides, human chorionic gonadotropin (hCG) and its free subunits were parallel in T21 pregnancies as recently observed in normal pregnancies. These results are in line with previous observations suggesting that the biosynthesis of both hCG and EPIL follows common regulation pathways.

Evaluating a new strategy for prophylaxis to prevent Pneumocystis carinii pneumonia in HIV-exposed infants in Thailand. Bangkok Collaborative Perinatal HIV Transmission Study Group

OBJECTIVE

To evaluate a strategy for prophylaxis against Pneumocystis carinii pneumonia (PCP) for infants in Thailand.

METHODS

HIV-infected women were offered trimethoprim-sulfamethoxazole for PCP prophylaxis for their children at 1-2 months of age. When the children reached 6 months of age, investigators simulated a decision to continue or stop prophylaxis on the basis of clinical criteria, and compared their decisions with results of polymerase chain reaction (PCR) testing for HIV. We calculated the proportions of children who received and completed prophylaxis, and compared the rates of pneumonia and death from pneumonia with rates from an earlier prospective cohort.

RESULTS

Of 395 eligible infants, 383 (97%) started prophylaxis. By 6 months of age, 10 (2.6%) were lost to follow-up, three (0.8%) were non-adherent, seven (2%) had stopped because of adverse events, four (1%) had died, and 359 (94%) still received prophylaxis. At 6 months of age, 30 (70%) of 43 HIV-infected children and 16 (5%) of 316 uninfected children met the clinical criteria to continue prophylaxis. The incidence of pneumonia at 1 to 6 months of age was 22% (15/68) in the earlier cohort, and 13% (6/46) in the recent cohort [relative risk (RR) 0.6, 95% confidence interval (CI) 0.3-1.4; P= 0.22]; mortality rates were 9% and 4%, respectively (RR 0.5; 95% CI 0.1-2.3; P = 0.47).

CONCLUSION

This PCP prophylaxis strategy appeared to be acceptable and safe, may have reduced morbidity and mortality from pneumonia, and should be considered in developing countries where early laboratory diagnosis of perinatal HIV infection is unavailable.

Determinants of depression and HIV-related worry among HIV-positive women who have recently given birth, Bangkok, Thailand

HIV-infected pregnant women have been the focus of considerable research related to biomedical issues of mother-to-child transmission worldwide. However, there have been few reports on the psychological well-being of new mothers with HIV, either in developed or developing countries. As part of a perinatal HIV transmission and family impact study in Bangkok, predictors of psychological scales were evaluated from interview data (N = 129) collected 18-24 months postpartum. Standardised questionnaires were used to assess depressive symptoms and HIV-related worry. Depressive symptomatology and HIV-related worry were common amongst these women. Multivariate logistic regression analysis identified several factors that predicted these psychological outcomes. High depression scores were associated with women who were no longer in a relationship with their partner (odds ratio (OR) 5.72, confidence interval (CI) 2.18-14.97) and who used venting coping strategies (OR 2.15, CI 1.44-3.21). Higher levels of HIV-related worry were associated with women whose babies were HIV-infected (OR 3.51, CI 1.28-10.69), who had not disclosed their HIV status to others (OR 3.05, CI 1.29-7.24) and who reported that their HIV-infection was something about which their family would be ashamed (OR 3.44, CI 1.34-9.77). Based on the current findings, intervention strategies we propose are psychological interventions which address disclosure issues, feelings of shame and coping strategies as well as financial assistance for single mothers. Interventions that require few resources such as group counselling or support merit special consideration.

Willingness of injection drug users to participate in an HIV vaccine efficacy trial in Bangkok, Thailand

We assessed willingness to participate in an HIV recombinant gp120 bivalent subtypes B/E candidate vaccine efficacy trial among 193 injection drug users (IDUs) attending drug treatment clinics in Bangkok, Thailand. IDUs previously enrolled in a prospective cohort study were invited to group sessions describing a potential trial, then completed questionnaires assessing comprehension and willingness to participate. A week later, they completed a follow-up questionnaire that again assessed comprehension and willingness to participate, as well as barriers to and positive motives for participation, with whom (if anyone) they talked about the information, and whether others thought participation was a good, bad, or neutral idea. At baseline, 51% were definitely willing to participate, and at follow-up 54%; only 3% were not willing to participate at either time. Comprehension was high at baseline and improved at follow-up. Participants who viewed altruism, regular HIV tests, and family support for participation as important were more willing to volunteer. Frequency of incarceration and concerns about the length of the trial, possible vaccine-induced accelerated disease progression, and lack of family support were negatively associated with willingness. Overall, IDUs comprehended the information needed to make a fully informed decision about participating in an rgp120 vaccine efficacy trial and expressed a high level of willingness to participate in such a trial.

Pro-EPIL forms are present in amniotic fluid and maternal serum during normal pregnancy

Recent observations based on immunohistochemistry and RT-PCR demonstrate that early placenta insulin-like peptide (EPIL), encoded by the INSL4 gene, is present in the placenta during gestation. In the present study, we report on the development of a specific immunoassay, entirely based on two monoclonal anti-peptide antibodies (mAbs), and its use for the detection of pro-EPIL forms in biological fluids during pregnancy. One mAb directed against the C-connecting peptide was used to capture pro-EPIL forms and their binding was revealed by a radiolabeled anti-A chain mAb as the indicator. A composite synthetic peptide, encompassing the C- and A-domains, was utilized as the standard. Under these experimental conditions, the assay displays a sensitivity limit of 2 ng/mL. Pro-EPIL molecular forms were detected in both amniotic fluid and maternal serum of pregnant women. At 12 to 16 weeks of pregnancy, the pro-EPIL level was higher in amniotic fluid (246 +/- 50.8 ng/mL) than in maternal serum (5 +/- 2.0 ng/mL). As gestation advanced, so the concentration of pro-EPIL forms decreased in amniotic fluid while its level increased in maternal serum. Interestingly, in amniotic fluid, the pattern of pro-EPIL concentration during pregnancy is very similar to that observed for human chorionic gonadotropin (hCG) and its free subunits. The pattern of serum pro-EPIL concentration is similar to that of the free alpha-subunit. Together with our previous immunohistochemical observations, these results indicate that pro-EPIL is preferentially secreted by cytotrophoblasts in amniotic fluid and that the biosynthesis of hCG subunits and EPIL may be regulated by common pathways. Overall, our observations strongly suggest that EPIL may play a critical physiological role during embryonic and foetal development.

Modulation of human chorionic gonadotrophin bioactivity during the first trimester of pregnancy

The objective of this study was to evaluate the bioactivity of human chorionic gonadotrophin (HCG) during first trimester pregnancy. This was done by means of a retrospective analysis of sera from patients with first trimester normal intrauterine and ectopic pregnancies. Serum samples were obtained from 38 women with amenorrhoea of <10 weeks. From these, 19 had a normal intrauterine pregnancy (IUP) and 19 an ectopic pregnancy (EP). Cases were allocated to either low serum immunoreactive HCG (HCGi), intermediate HCGi or high HCGi concentrations (HCGi <5000 mUI/ml, between 5000 and 40,000 mIU/ml and >40,000 mIU/ml respectively). HCGi and oestradiol were measured by enzyme immunoassays and bioactive HCG by the mouse Leydig cell bioassay. All results were analysed by analysis of variance and unpaired Student's t-test. There was a significant difference between bioactive to immunoreactive HCG ratios (b/i ratio) between the subgroups of low, intermediate and high HCGi concentrations. Lower b/i ratios were found when HCGi concentrations were high (HCG b/i mean +/- SEM: high subgroup, 0.33 +/- 0.07 versus low subgroup: 1.50 +/- 0.12; P < 0.0001). Furthermore, the b/i ratios were inversely correlated with oestradiol (P < 0.0001) and HCGi (P < 0.0001) concentrations but not with gestational age. There was no difference in the b/i ratios when comparing IUP with EP. It is concluded that, in first trimester pregnancies, there is a likely modulation of HCG bioactivity which is inversely correlated with HCGi and oestradiol concentration. The underlying mechanisms and their physiological relevance remain to be elucidated.

Response to JE vaccine among HIV-infected children, Bangkok, Thailand

Since 1990, Japanese encephalitis (JE) vaccine has been part of EPI in northern Thailand, where there is a high prevalence of JE and HIV infection. To evaluate the immunogenicity and safety of JE vaccine among HIV-infected children, we conducted a retrospective study of HIV-infected and uninfected children who received 2 doses of JE vaccine at 12 months of age. Pre- and post-immunization plasma specimens were tested by plaque reduction neutralization for antibody levels to JE and dengue(1-4) viruses; titers of > or =10 were considered positive. Excluding 5 children with preimmunization antibodies, 5 of 14 (36%) HIV-infected children and 18 of 27 (67%) uninfected children had positive JE antibody titers after immunization [odds ratio (OR) 0.3, p=0.06]; 31% absolute difference [95% confidence interval (CI) 0-61.7%). The geometric mean titer of HIV-infected children with positive titers was lower than that of control children (15.1 vs, 23.8; p=0.17). No significant vaccine-associated adverse events were noted. We conclude that primary antibody response to JE vaccine was low among HIV-infected children and was approximately half of that seen among uninfected children. In endemic areas, HIV-infected children are likely to be at risk of acquiring JE despite routine immunization with 2 doses.

HIV prevalence, risk, and partner serodiscordance among pregnant women in Bangkok. Bangkok Collaborative Perinatal HIV Transmission Study Group

CONTEXT

Most prior studies of the human immunodeficiency virus (HIV) epidemic in Thailand have focused on commercial sex encounters; however, because the epidemic increasingly concerns stable heterosexual relationships, determining risk factors for this form of transmission is warranted.

OBJECTIVES

To determine temporal trends in HIV prevalence, risk factors for HIV seropositivity, and rates of partner serodiscordance for pregnant women in Bangkok, Thailand.

DESIGN

Retrospective review of hospital antenatal clinic HIV test results from 1991 through 1996. Baseline demographic and behavioral risk factors for HIV were assessed for subjects enrolled from November 1992 through March 1994.

SETTING

Two Bangkok hospitals with routine antenatal clinic HIV counseling and testing.

PARTICIPANTS

The HIV-positive pregnant women enrolled in a perinatal HIV transmission study and their partners and HIV-negative pregnant controls.

RESULTS

From 1991 through 1996, antenatal clinic HIV seroprevalence increased from 1.0% to 2.3%. On multivariate analysis of data from 342 HIV-positive and 344 HIV-negative pregnant women, more than 1 lifetime sex partner, history of a sexually transmitted disease, and a high-risk sex partner were the most important factors for seropositivity (all P<.001). Twenty-six percent of partners of HIV-positive women were HIV negative. Women reporting more than 1 lifetime sex partner were more likely to have an HIV-negative partner than women reporting only 1 (45% vs 8%; relative risk, 5.5; 95% confidence interval, 3.2-9.5; P<.001); women reporting no high-risk behaviors were less likely to have an HIV-negative partner (10% vs 44%; relative risk, 0.2; 95% confidence interval, 0.1-0.4; P<.001).

CONCLUSIONS

Prevalence of HIV in pregnant women has increased steadily in Bangkok from 1991 through 1996. Sex with current partners was the only identified risk exposure for about half (52%) of the HIV-positive women. Although few HIV-positive pregnant women reported high-risk behaviors, more than 1 lifetime partner and a partner with high-risk behavior were strong risk factors for seropositivity. Together with the unexpected finding that one fourth of partners of seropositive pregnant women were seronegative, these data emphasize that women in the general population are at risk for HIV because of the risk behavior of both current and previous partners.

The apparent late half-life of human chorionic gonadotropin (hCG) after surgical treatment for ectopic pregnancy. A new approach to diagnose persistent trophoblastic activity

OBJECTIVE

The disappearance kinetic of human chorionic gonadotropin (hCG) follows a biexponential decay with a rapid initial fall followed later by a slow disappearance. This kinetic is characterised by two half-lives: an early and a late. The objective of this study was to determine if and which half-life could be used clinically to detect persistent trophoblast after conservative surgery in patients with ectopic pregnancy.

DESIGN

Retrospective analysis of patients having undergone salpingostomy by laparoscopy for an ectopic tubal pregnancy between January 1990 and October 1993.

SETTING

Gynaecology Department of an University Hospital.

PATIENTS

104 women with diagnosed tubal ectopic pregnancy were treated by salpingostomy performed under laparoscopy. In seven cases, persistent trophoblast was diagnosed on the basis of plateauing or increasing peripheral hCG values.

MAIN RESULTS

From the individual disappearance curves of hCG we calculated the early half-life (early T0.5, from samples obtained between 0 and 48 h postsurgery) and the late half-life (late T0.5, from samples obtained between 2 and 7 days postsurgery). Late T0.5 but not early T0.5 were significantly (P<0.0001 and P=0.416 respectively) longer in women (n =7) in whom a persistent trophoblast was diagnosed. Early T0.5 was dependant on the preoperative value of hCG, whereas late T0.5 was independent. We propose to use late T0.5 as a parameter to follow ectopic pregnancies after treatment.

Identification of pro-EPIL and EPIL peptides translated from insulin-like 4 (INSL4) mRNA in human placenta

Recently, a new member of the insulin gene superfamily termed insulin-like 4 (INSL4) was identified in the human placenta and uterus. The present study investigated whether placenta translates INSL4 mRNA into a putative peptide named early placenta insulin-like (EPIL). Among antibodies elicited against the C chain of pro-EPIL, one antibody (AB7381) was specifically directed against the C chain 59-88 portion, and among those elicited against the A and B chains of EPIL, one antibody (Ab1661) was directed against the A chain 115-139 and the B chain 23-52 portions. Immunohistochemistry based on antibody 7381 to pro-EPIL and antibody 1661 to EPIL demonstrated that the cytotrophoblast from early placenta preferentially expresses the pro-EPIL peptide, whereas the EPIL peptide is expressed by both the cytotrophoblast and the syncytiotrophoblast. At term, the pro-EPIL peptide was detected in villous cytotrophoblast cells, whereas the EPIL peptide was not detected. Moreover, in vitro experiments performed on term placenta showed that the steady state levels of INLS-4 mRNA in the cytotrophoblast are 10 times (one log unit) lower than in the differentiated villous syncytiotrophoblast cells. Taken together, these findings reveal that expression of EPIL peptides in the villous cytotrophoblast is different from that displayed by the syncytiotrophoblast. Finally, these data are the first demonstration that INSL4 mRNA are translated into pro-EPIL and EPIL peptides.

Optical properties of deep ice at the South Pole: absorption

We discuss recent measurements of the wavelength-dependent absorption coefficients in deep South Pole ice. The method uses transit-time distributions of pulses from a variable-frequency laser sent between emitters and receivers embedded in the ice. At depths of 800-1000 m scattering is dominated by residual air bubbles, whereas absorption occurs both in ice itself and in insoluble impurities. The absorption coefficient increases approximately exponentially with wavelength in the measured interval 410-610 nm. At the shortest wavelength our value is approximately a factor 20 below previous values obtained for laboratory ice and lake ice; with increasing wavelength the discrepancy with previous measurements decreases. At ~415 to ~500 nm the experimental uncertainties are small enough for us to resolve an extrinsic contribution to absorption in ice: submicrometer dust particles contribute by an amount that increases with depth and corresponds well with the expected increase seen near the Last Glacial Maximum in Vostok and Dome C ice cores. The laser pulse method allows remote mapping of gross structure in dust concentration as a function of depth in glacial ice.

Implantable cardioverter defibrillator clinic casualties: inadvertent reprogramming during routine implantable cardioverter defibrillator follow-up

On one occasion during a busy ICD follow-up clinic, the preceding patient's parameters for rate, PDF, and delay were inadvertently programmed into the subsequent patient's generator using the CPI Programmer Model 2035. This occurred after capacitor reformation, without pressing the "Program" button. The source of this reprogramming error was failure to clear the programmer memory of the previous patient's data, usually achieved by turning the programmer off between patients (or selecting "New Patient" from the menu). At our next ICD follow-up clinic, we purposely did not turn off the programmer between two sets of patients. On both occasions the above finding was repeated and confirmed. These observations indicate the potential for serious reprogramming errors that can occur simply by not clearing the programmer's memory between clinic patients.

PEAPS-Q: a questionnaire to measure the psychosocial effects of having an abnormal pap smear. Psychosocial Effects of Abnormal Pap Smears Questionnaire

We have developed the Psychosocial Effects of Abnormal Pap Smears Questionnaire (PEAPS-Q) which measures distress experienced by women undergoing follow-up investigation after an abnormal Pap smear result. A thorough literature review and qualitative research resulted in the development of a questionnaire which was tested on 350 women attending a Family Planning New South Wales (FPNSW) clinic. This sample included women at different stages of management after detection of a cervical abnormality: 93 first colposcopy clients and 257 follow-up colposcopy clients. Factor analysis identified four dimensions of distress: experience of medical procedures, beliefs/feelings about cervical abnormality and changes in perception of oneself, worry about infectivity and effect on sexual relationships. Repeatability of the PEAPS-Q was indicated by intra-class correlations of 0.88 overall and at least 0.60 for each scale. Internal consistency was shown by Cronbach's alpha of 0.84 overall and at least 0.72 for each scale. Validity was demonstrated by the correlation of scale scores with the 12-item General Health Questionnaire (GHQ) score of 0.32 (95% CI 0.22-0.41). The PEAPS-Q is a valid, reliable and multidimensional instrument for quantifying distress experienced by women with abnormal Pap smears.

A prospective cohort study investigating psychosocial predictors of attendance at a mobile breast screening service

This study aimed to examine whether knowledge, attitudes and concerns predicted attendance at the mobile Breast X-Ray Programme in Sydney. A cohort study design was used, whereby women were surveyed prior to the implementation of the program, and two years later records were checked to determine whether they had attended for screening. Telephone interviews were sought with randomly selected women aged 45 to 70 years living in the central Sydney area (the screening van's catchment area). A total of 285 women was surveyed (response rate: 50 per cent). Of these, 86 (30 per cent) subsequently attended at the mobile van and 199 did not. Attendance did not appear to be related to any of the following factors: knowledge; attitudes; prior experience; perceived susceptibility and morbid concern in relation to breast cancer; the amount of information about screening mammography to which a woman had been exposed. The results are interpreted in light of methodological considerations plus findings from our other research.

Efficient study designs to assess the accuracy of screening tests

Evaluating a screening test often requires estimation of test sensitivity and specificity with appropriately narrow confidence intervals and at least cost. If the major cost is the reference ("gold") standard, savings arise from reducing the large number of test negatives that are verified by the reference standard. On the basis of the formulae of Begg and Greenes (Biometrics 1983;39:207-15), the authors determine the optimal sampling strategy for test positives and test negatives to minimize the total sample size that needs to be verified for a given confidence interval width for sensitivity. Unless sensitivity is very high, verifying more test positives and fewer test negatives than would occur with equal sampling fractions is appropriate. For example, if the sensitivity is 0.7 and the specificity is 0.99, the optimal sampling strategy is for 6.2% of those verified to be test positives, compared with 1.7% in the case of equal sampling fractions. At a disease prevalence of 0.01, the 3.3-fold increase in test positives results in a saving of about 15% in the test negatives and 11% in the total verified sample size. Overall, savings are about 50% for a sensitivity of 0.3, but are negligible when sensitivity is greater than 0.8. Optimal sampling strategies for sensitivity do not materially alter confidence intervals for specificity. Figures are presented from which readers can easily obtain the optimal sampling strategy given an estimate of specificity, approximated by the proportion of screenees who are test negative, and the range of likely sensitivity.

Women's perceptions of screening mammography

A random sample of women in Sydney were interviewed by telephone to determine their knowledge about and attitudes to mammography. A response rate of 56 per cent (628 women) was obtained. While the majority of women had had some experience with breast cancer, knowledge about which age groups were most at risk and treatment alternatives was limited. Only about half of the sample had heard about screening mammography before the survey. However, when a simple explanation was given, 79 per cent expressed a favourable attitude toward it. Only 22 per cent of women thought of themselves as being personally susceptible to breast cancer; the proportion was lower in women over 60 than in those in their 40s. Morbid concern about breast cancer was rare. About a quarter of the sample expressed concern about mammographically induced exposure to radiation. Attitudes and perceptions of personal susceptibility were not associated with knowledge about risks of breast cancer. However, having a favourable attitude and a lack of concern about radiation were associated with previously having heard about screening mammography. Women speaking a language other than English at home and from households where the main income earner was in an unskilled occupation were least likely to have heard of screening mammography. Suggestions for data-based recruitment strategies are discussed.

Encouraging attendance at screening mammography: knowledge, attitudes and intentions of general practitioners

We surveyed a random sample of 200 general practitioners from the Sydney metropolitan area about their attitudes to and knowledge of screening mammography. General practitioners' knowledge about some aspects of screening mammography was found to be limited; only 25% of the sample knew that the risk of breast cancer increases with age and only 30% of the sample knew that the evidence for a reduction in mortality as a result of mammographic screening is weakest for women of less than 50 years of age. Ninety-five per cent of general practitioners were of the opinion that breast self-examination and clinical examination were important for asymptomatic women of more than 45 years of age compared with the 75% of respondents who viewed mammography in the same way. Scores on a scale that was constructed to measure attitudes to mammographic screening showed that 20% of general practitioners had a "very favourable" attitude, and that a further 67% of general practitioners had a "favourable" attitude. No general practitioners had a "very unfavourable" attitude. Eighty-four per cent of general practitioners indicated that they would recommend that their patients attend a free screening-mammography service. Willingness to recommend mammographic screening was predicted by a general practitioner's attitude score. The strongest component of this prediction was a belief that the benefits of screening mammography outweighed the radiation risks. General practitioners need to be supplied with correct information about target groups for screening, so that women in the appropriate age-groups are encouraged to attend screening programmes.

Predictors of surgical wound infection in Australia: a national study

In July 1984, the first national Australian Nosocomial Prevalence Survey collected data on 12,742 surgical patients from 265 hospitals. This sample represented 59% of public and private hospitals with 50 or more acute-care beds in Australia. The infection control officers at each hospital provided data on patients in a random sample of beds. The over-all surgical wound infection rate was 4.6%. The surgical wound infection rate was twice (5.4%) as high in public than in private (2.8%) hospitals. The infection rates were greater in larger hospitals in both the public and private sector. However, after adjusting for the other predictor factors that are noted below the infection rate did not show any particular pattern for the size of hospital. Clean surgery had a higher (4.8%) infection rate than did clean-contaminated surgery (2.9%). The infection rate for contaminated surgery was 15.0%. Men were found to have nearly twice (6.5%) the infection rate of women (3.4%). Infection rates were lowest in the 15-to-34 years' age-group and highest in those of over 55 years of age. These trends remained even after adjusting for the other risk factors for infection. The cost of surgical wound infections for all hospitals during the year of 1984 was estimated at approximately $60 million. We suggest that a concerted effort should be made to attempt to reduce the infection rate for clean surgery to 1% or less.

Chylomicrons and chylomicron remnants in coronary artery disease: a case-control study

Epidemiologic studies of coronary artery disease have largely overlooked the role of triglyceride-rich lipoproteins circulating in the post-prandial state. We have conducted a case-control study in males which examined fasting plasma lipoproteins and lipoproteins circulating 4 h after ingestion of a test meal containing fat and cholesterol. The cases were 82 subjects with coronary artery disease confirmed by angiography, while there were two control groups: one group of 38 'hospital controls' free of significant coronary disease by angiography, and a second group of 61 'workforce controls' free of coronary disease on historical grounds. Mean plasma and LDL cholesterol levels were significantly higher and HDL cholesterol levels were significantly lower in cases than in controls. The apo-B48/apo-B100 ratio in lipoproteins Sf greater than 60 obtained 4 h post-prandially, a relative measure of chylomicron and remnant presence, was significantly higher in cases than in controls. After pooling of all data, the prevalence of coronary artery disease was found to increase progressively with the concentration of plasma cholesterol and triglycerides, total cholesterol/HDL cholesterol ratio and the apo-B48/apo-B100 ratio in Sf greater than 60, the relative risk being highest for total cholesterol/HDL cholesterol ratio. After controlling for the confounding effects of age and other lipid factors via multiple logistic regression, apo-B48/apo-B100 ratio was still a significant predictor of coronary artery disease presence (z = 1.97, P less than 0.05) in a 'dose-response' fashion. The risk of coronary artery disease in the top quartile of apo-B48/apo-B100 distribution was 2.2-fold greater than that for the bottom quartile, after adjustment for the effects of other risk factors.(ABSTRACT TRUNCATED AT 250 WORDS)