Evaluation of prognostic risk models for postoperative pulmonary complications in adult patients undergoing major abdominal surgery: a systematic review and international external validation cohort study

BACKGROUND

Stratifying risk of postoperative pulmonary complications after major abdominal surgery allows clinicians to modify risk through targeted interventions and enhanced monitoring. In this study, we aimed to identify and validate prognostic models against a new consensus definition of postoperative pulmonary complications.

METHODS

We did a systematic review and international external validation cohort study. The systematic review was done in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We searched MEDLINE and Embase on March 1, 2020, for articles published in English that reported on risk prediction models for postoperative pulmonary complications following abdominal surgery. External validation of existing models was done within a prospective international cohort study of adult patients (≥18 years) undergoing major abdominal surgery. Data were collected between Jan 1, 2019, and April 30, 2019, in the UK, Ireland, and Australia. Discriminative ability and prognostic accuracy summary statistics were compared between models for the 30-day postoperative pulmonary complication rate as defined by the Standardised Endpoints in Perioperative Medicine Core Outcome Measures in Perioperative and Anaesthetic Care (StEP-COMPAC). Model performance was compared using the area under the receiver operating characteristic curve (AUROCC).

FINDINGS

In total, we identified 2903 records from our literature search; of which, 2514 (86·6%) unique records were screened, 121 (4·8%) of 2514 full texts were assessed for eligibility, and 29 unique prognostic models were identified. Nine (31·0%) of 29 models had score development reported only, 19 (65·5%) had undergone internal validation, and only four (13·8%) had been externally validated. Data to validate six eligible models were collected in the international external validation cohort study. Data from 11 591 patients were available, with an overall postoperative pulmonary complication rate of 7·8% (n=903). None of the six models showed good discrimination (defined as AUROCC ≥0·70) for identifying postoperative pulmonary complications, with the Assess Respiratory Risk in Surgical Patients in Catalonia score showing the best discrimination (AUROCC 0·700 [95% CI 0·683-0·717]).

INTERPRETATION

In the pre-COVID-19 pandemic data, variability in the risk of pulmonary complications (StEP-COMPAC definition) following major abdominal surgery was poorly described by existing prognostication tools. To improve surgical safety during the COVID-19 pandemic recovery and beyond, novel risk stratification tools are required.

FUNDING

British Journal of Surgery Society.

Perioperative intravenous contrast administration and the incidence of acute kidney injury after major gastrointestinal surgery: prospective, multicentre cohort study

BACKGROUND

This study aimed to determine the impact of preoperative exposure to intravenous contrast for CT and the risk of developing postoperative acute kidney injury (AKI) in patients undergoing major gastrointestinal surgery.

METHODS

This prospective, multicentre cohort study included adults undergoing gastrointestinal resection, stoma reversal or liver resection. Both elective and emergency procedures were included. Preoperative exposure to intravenous contrast was defined as exposure to contrast administered for the purposes of CT up to 7 days before surgery. The primary endpoint was the rate of AKI within 7 days. Propensity score-matched models were adjusted for patient, disease and operative variables. In a sensitivity analysis, a propensity score-matched model explored the association between preoperative exposure to contrast and AKI in the first 48 h after surgery.

RESULTS

A total of 5378 patients were included across 173 centres. Overall, 1249 patients (23·2 per cent) received intravenous contrast. The overall rate of AKI within 7 days of surgery was 13·4 per cent (718 of 5378). In the propensity score-matched model, preoperative exposure to contrast was not associated with AKI within 7 days (odds ratio (OR) 0·95, 95 per cent c.i. 0·73 to 1·21; P = 0·669). The sensitivity analysis showed no association between preoperative contrast administration and AKI within 48 h after operation (OR 1·09, 0·84 to 1·41; P = 0·498).

CONCLUSION

There was no association between preoperative intravenous contrast administered for CT up to 7 days before surgery and postoperative AKI. Risk of contrast-induced nephropathy should not be used as a reason to avoid contrast-enhanced CT.

Safety assessment of the biotechnologically produced human-identical milk oligosaccharide 3-Fucosyllactose (3-FL)

3-Fucosyllactose (3-FL), a highly abundant complex carbohydrate in human breast milk, functions as a prebiotic promoting early microbial colonization of the gut, increasing pathogen resistance and modulating immune responses. To investigate potential health benefits, 3-FL was produced by fermentation using a genetically modified E. coli K12 strain. The safety assessment of 3-FL included acute oral toxicity, in vitro and in vivo assessment of genetic toxicity, and a subchronic rodent feeding study. 3-FL was not acutely toxic at 5000 mg/kg bw, and there was no evidence of genetic toxicity in the bacterial reverse mutation test and chromosomal aberration assay. There was a repeatable statistically-significant trend in the 4-h S9-activated test conditions in the in vitro micronucleus assay; the confirmatory in vivo mouse micronucleus study was negative at all doses. Dietary subchronic exposure of rats to 3-FL (5% and 10%) did not produce any statistical or biologically-relevant differences in growth, food intake or efficiency, clinical observations, or clinical or anatomic pathology changes at average daily intakes of 5.98 and 7.27 g/kg bw/day for males and females, respectively. The weight of evidence from these studies support the safe use of 3-FL produced using biotechnology as a nutritional ingredient in foods.

Development of a low-maintenance measurement approach to continuously estimate methane emissions: A case study

The chemical breakdown of organic matter in landfills represents a significant source of methane gas (CH₄). Current estimates suggest that landfills are responsible for between 3% and 19% of global anthropogenic emissions. The net CH₄ emissions resulting from biogeochemical processes and their modulation by microbes in landfills are poorly constrained by imprecise knowledge of environmental constraints. The uncertainty in absolute CH₄ emissions from landfills is therefore considerable. This study investigates a new method to estimate the temporal variability of CH₄ emissions using meteorological and CH₄ concentration measurements downwind of a landfill site in Suffolk, UK from July to September 2014, taking advantage of the statistics that such a measurement approach offers versus shorter-term, but more complex and instantaneously accurate, flux snapshots. Methane emissions were calculated from CH₄ concentrations measured 700m from the perimeter of the landfill with observed concentrations ranging from background to 46.4ppm. Using an atmospheric dispersion model, we estimate a mean emission flux of 709μgm^-2s^-1 over this period, with a maximum value of 6.21mgm^-2s^-1, reflecting the wide natural variability in biogeochemical and other environmental controls on net site emission. The emissions calculated suggest that meteorological conditions have an influence on the magnitude of CH₄ emissions. We also investigate the factors responsible for the large variability observed in the estimated CH₄ emissions, and suggest that the largest component arises from uncertainty in the spatial distribution of CH₄ emissions within the landfill area. The results determined using the low-maintenance approach discussed in this paper suggest that a network of cheaper, less precise CH₄ sensors could be used to measure a continuous CH₄ emission time series from a landfill site, something that is not practical using far-field approaches such as tracer release methods. Even though there are limitations to the approach described here, this easy, low-maintenance, low-cost method could be used by landfill operators to estimate time-averaged CH₄ emissions and their impact downwind by simultaneously monitoring plume advection and CH₄ concentrations.

Constraints on oceanic methane emissions west of Svalbard from atmospheric in situ measurements and Lagrangian transport modeling

Methane stored in seabed reservoirs such as methane hydrates can reach the atmosphere in the form of bubbles or dissolved in water. Hydrates could destabilize with rising temperature further increasing greenhouse gas emissions in a warming climate. To assess the impact of oceanic emissions from the area west of Svalbard, where methane hydrates are abundant, we used measurements collected with a research aircraft (Facility for Airborne Atmospheric Measurements) and a ship (Helmer Hansen) during the Summer 2014 and for Zeppelin Observatory for the full year. We present a model-supported analysis of the atmospheric CH₄ mixing ratios measured by the different platforms. To address uncertainty about where CH₄ emissions actually occur, we explored three scenarios: areas with known seeps, a hydrate stability model, and an ocean depth criterion. We then used a budget analysis and a Lagrangian particle dispersion model to compare measurements taken upwind and downwind of the potential CH₄ emission areas. We found small differences between the CH₄ mixing ratios measured upwind and downwind of the potential emission areas during the campaign. By taking into account measurement and sampling uncertainties and by determining the sensitivity of the measured mixing ratios to potential oceanic emissions, we provide upper limits for the CH₄ fluxes. The CH₄ flux during the campaign was small, with an upper limit of 2.5 nmol m^-2 s^-1 in the stability model scenario. The Zeppelin Observatory data for 2014 suggest CH₄ fluxes from the Svalbard continental platform below 0.2 Tg yr^-1. All estimates are in the lower range of values previously reported.

Inhalation Two-Generation Reproductive Toxicity Study of Methyl Isobutyl Ketone in Rats

To evaluate whether methyl isobutyl ketone (MIBK) affects reproductive performance, a two-generation reproduction study was conducted. MIBK was administered to 30 Sprague-Dawley rats/sex/group via whole-body inhalation at concentrations of 0, 500, 1000, or 2000 ppm, 6 h daily, for 70 days prior to mating. F0 and F1 females were exposed from mating through gestation day 20 and from postnatal day 5; F2 litters were maintained through post-natal day 21. No treatment-related mortality of adult animals occurred. There was a dose-related increase in adult animals with no or a decreased response to a sound stimulus at 1000 and 2000 ppm; however, no adverse clinical signs occurred 1 h after exposure, suggesting this was a transient sedative effect. Clinical signs of central nervous system (CNS) depression in the pups were observed and one F1 pup died after initial exposure to 2000 ppm on postnatal day 22; subsequently exposure was delayed until postnatal day 28. Decreased body weight gain and slight decreased food consumption were observed during the first 2 weeks of exposure in both generations at 2000 ppm. There were no adverse effects on male and female reproductive function or landmarks of sexual maturation. Increased F0 and F1 liver weights with associated centrilobular hypertrophy occurred in rats at 2000 ppm, indicative of an adaptive response. Increased male kidney weights at all exposure concentrations, associated with hyaline droplets, were indicative of male rat-specific nephropathy. Other than acute sedative effects, the no-observed-adverse-effect level (NOAEL) for parental systemic effects (excluding male rat kidney) was 1000 ppm, based on transient decreased body weight and food consumption; for reproductive effects, 2000 ppm, the highest concentration tested; and for neonatal toxicity, 1000 ppm (based on acute CNS depressive effects).

Biochemical and molecular characteristics of patients with organic acidaemias and urea cycle disorders identified through newborn screening

BACKGROUND

In recent years it has become clear that newborn screening (NBS) programmes using tandem mass spectrometry identify "patients" with "classical" inborn errors of metabolism who are asymptomatic. This observation raises issues regarding medicalization of "non-diseases," potentially unnecessary treatment and unnecessary anxiety to parents.

AIMS

This study aims to identify possible markers that may assist in predicting the need for treatment of infants with "classical" organic acidaemias (OA) and urea cycle disorders (UCD) diagnosed through NBS.

METHODS

Medical records of all patients with classical OA and UCD detected through the Victorian NBS programme from February 2002 to January 2014, or diagnosed clinically between 1990 and January 2002 were retrospectively reviewed.

RESULTS

Neonatal presentation did not always predict the need for on-going strict treatment. Blood concentrations of amino acids and acyl-carnitines and the changes thereof in follow-up samples correlated with severity in citrullinaemia-I, possibly isovaleric acidaemia but not in argininosuccinic aciduria or propionic acidaemia. Some specific mutations correlate with "attenuated" citrullinaemia-I. Gender may affect clinical outcome in propionic acidaemia.

CONCLUSIONS

Changes in blood concentration of certain metabolites (amino acids, acyl-carnitines) in the first weeks of life may be predictive of the need for treatment in some disorders but not in others. Mutation analysis may be predictive in some disorders but whether or not this should be considered as second-tier testing in NBS should be discussed separately.

Beta-ureidopropionase deficiency presenting with congenital anomalies of the urogenital and colorectal systems

Beta-ureidopropionase deficiency (McKusick 606673) is an autosomal recessive condition caused by mutations in the UPB1 gene. To date, five patients have been reported, including one putative case detected through newborn screening. Clinical presentation includes neurological and developmental problems. Here, we report another case of beta-ureidopropionase deficiency who presented with congenital anomalies of the urogenital and colorectal systems and with normal neurodevelopmental milestones. Analysis of a urine sample, because of the suspicion of renal stones on ultrasound, showed strongly elevated levels of the characteristic metabolites, N-carbamyl-beta-amino acids. Subsequent analysis of UPB1 identified a novel mutation 209 G>C (R70P) in exon 2 and a previously reported splice receptor mutation IVS1-2A>G. Expression studies of the R70P mutant enzyme showed that the mutant enzyme did not possess any residual activity. Long-term follow-up is required to determine the clinical significance of the beta-ureidopropionase deficiency in our patient.

Direct restorative materials use in Australia in 2002

BACKGROUND

This study aimed to determine the reasons for dentists' choice of materials, in particular amalgam and resin composite, in Australia.

METHOD

A questionnaire was developed to elicit this information. The names and addresses of 1000 dentists in Australia were selected at random. The questionnaire was mailed to these dentists with an explanatory letter and reply-paid envelope.

RESULTS

A total of 560 replies were received. Regarding choice of material, 99 per cent of respondents cited clinical indication as an influencing factor, although patients' aesthetic demands (99 per cent of respondents), patients' wish (96 per cent), patients' financial situation (82 per cent), and lecturers' suggestions (72 per cent) were also reported to influence respondents' choice of materials. Twelve per cent of respondents used composite 'always', 29 per cent 'often', 32 per cent 'sometimes', 23 per cent 'seldom' and 4 per cent 'never' in extensive load-bearing cavities in molar teeth. For composite restorations in posterior teeth, 84 per cent 'always', 'often' or 'sometimes' used the total etch technique, 84 per cent used a thick glass-ionomer layer and 36 per cent never used rubber dam. Fifty-nine per cent of respondents reported a decreased use of amalgam over the previous five years. Sixty-eight per cent of respondents agreed with the statement 'discontinuation of amalgam restricts a dentist's ability to adequately treat patients'. Seventy-five per cent considered that the growth in the use of composites increased the total cost of oral health care.

CONCLUSIONS

Of the respondents from Australia 73 per cent place large composite restorations in molar teeth and their choice of material is influenced greatly by clinical indications, and patients' aesthetic demands.

Quality of Life in Patients Treated with First-Line Antiretroviral Therapy Containing Nevirapine And/Or Efavirenz

Objective

To assess whether differences in safety profiles between nevirapine (NVP) and efavirenz (EFV), as observed in the 2NN study, translated into differences in ‘health related quality of life’ (HRQoL).

Design

A sub-study of the 2NN study, with antiretro-viral-naive patients randomly allocated to NVP (once or twice daily), EFV or NVP+EFV, in addition to stavudine and lamivudine.

Methods

Comparing differences in changes of HRQoL over 48 weeks as measured with the Medical Outcomes Study HIV Health Survey (MOS-HIV) questionnaire, using analysis of variance.

Results

The 2NN study enrolled 1216 patients. No validated questionnaires were available for 244 patients, and 55 patients had no HRQoL data at all, leaving 917 patients eligible for this sub-study. A total of 471 (51%) had HRQoL measurements both at baseline and week 48. The majority (69%) of patients without HRQoL measurements did, however, complete the study. The change in the physical health score (PHS) was 3.9 for NVP, 3.4 for EFV and 2.4 for NVP+EFV ( P=0.712). For the mental health score (MHS) these values were 6.1, 7.0 and 3.9, respectively ( P=0.098). A baseline plasma HIV-1 RNA concentration (pVL) ≥100 000 copies/ml and a decline in pVL (per log10) were independently associated with an increase of PHS. An increase of MHS was only associated with pVL decline. Patients experiencing an adverse event during follow-up had a comparable change in PHS but a significantly smaller change in MHS, compared with those without an adverse event.

Conclusions

First-line ART containing NVP and/or EFV leads to an improvement in HRQoL. The gain in HRQoL was similar for NVP and EFV, but slightly lower for the combination of these drugs.

3-Hydroxyglutarate excretion is increased in ketotic patients: implications for glutaryl-CoA dehydrogenase deficiency testing

Three patients with ketosis had increased excretion of 3-hydroxyglutarate (21.8-37.9 micromol/mmol creatinine; controls 2.3 +/- 1.6), an indicator of glutaryl-CoA dehydrogenase deficiency (GDHD), which normalized when the patients were nonketotic. Clinical assessment of all three patients and enzyme studies in one patient were not consistent with GDHD. These findings were compared with those of other ketotic patients, who showed statistically significant increases in 3-hydroxyglutarate excretion (9.4 +/- 5.0 micromol/mmol creatinine; p < 0.01), and with those of a child with confirmed GDHD when she was both ketotic and nonketotic. Secondary increase in 3-hydroxyglutarate excretion during ketosis is a potential confounder in the diagnosis of GDHD.

Successful treatment of chronic anal fissure with diltiazem gel

OBJECTIVE: Diltiazem is a calcium channel blocker that has shown potential to heal chronic anal fissures. We have prospectively evaluated the treatment of patients with anal fissure with diltiazem gel (SLA Pharma, UK). PATIENTS AND METHODS: All patients with chronic anal fissure from September 1999 to May 2000 were treated topically with 8 mg 2% diltiazem hydrochloride gel (equivalent to 2 cm of gel supplied by SLA Pharma) three times daily. The 23 patients (12 female), median age 45 (range 22-80) years had a 2-36 month (median 6 months) history of fissure. These were associated with a sentinel tag in 9 (39%) patients. RESULTS: The fissure healed in 11 (48%) of 23 patients, including 6 (75%) of 8 patients who previously failed to heal with GTN ointment. There were no recurrences at 3 months and no adverse effects. Of the 12 patients who did not respond to diltiazem, 4 have undergone sphincterotomy. CONCLUSION: Diltiazem gel has a healing rate similar to that observed with GTN ointment but there were no adverse effects, the recurrence rate was lower, and diltiazem was effective in 75% of patients previously treated unsuccessfully with GTN ointment.

Molybdopterin synthase mutations in a mild case of molybdenum cofactor deficiency

Molybdenum cofactor deficiency is a rare inborn error of metabolism with generally severe symptoms, most often including neonatal seizures and severe developmental delay. We describe a patient with an unusually mild form of the disease. Two mutations in MOCS2A (molybdenum cofactor synthesis enzyme 2A) were identified: a single base change, 16C > T, that predicts a Q6X substitution on one allele and a 19G > T transversion that predicts a valine to phenylalanine substitution, V7F, on the second. It is postulated that the milder clinical symptoms result from a low level of residual molybdopterin synthase activity derived from the 19G > T allele.

Pharmacokinetics of saquinavir-SGC in HIV-infected pregnant women

PURPOSE

To evaluate saquinavir (SQV) pharmacokinetics, tolerance, and safety in 10 HIV-infected pregnant women between 14-32 weeks gestation.

METHOD

This was a phase I, prospective, area-under-the-curve (AUC) targeted study. Antepartum treatment consisted of SQV 1200 mg tid, lamivudine 150 mg bid, and zidovudine 200 mg tid. The SQV targeted exposure was an 8-hour AUC (AUC(8)) of 3000 ng. h/mL; the study was to be halted if the first 4 participants did not achieve this AUC(8). Cord blood and plasma samples were collected in neonates at birth.

RESULTS

Four women completed the SQV pharmacokinetic assessments. Exposure in all 4 patients was below the target AUC(8). Median (range) AUC(8) and trough (C8H) were 1672 (738-2614) ng. h/mL and 60 (<15-332) ng/mL, respectively. Oral clearance (CL/F) was 9.3 (5.1-16.6) L/h/kg and C(max) was 599 (177-953) ng/mL. Cord and neonate plasma concentrations were mostly undetectable; 1 of 5 infants was HIV-infected at 24 weeks.

CONCLUSION

These data suggest highly variable SQV pharmacokinetics in pregnant women, and exposure at 1200 mg tid may not be adequate for longer term therapy; both the AUC(8) and C8H were considerably below average. Because ritonavir has been shown to significantly increase SQV concentrations, this combination should be further explored in this population.

Barriers to the use of dental services by individuals from minority ethnic communities living in the United Kingdom: findings from focus groups

OBJECTIVE

To describe the barriers identified by individuals from minority ethnic communities resident in the United Kingdom to their use of dental services.

METHOD

Focus group discussions were held with individuals from minority ethnic groups. Data were analysed using the technique of content analysis on the basis of categories defined by the researchers.

FINDINGS

Barriers to regular attendance identified by participants included: language, a mistrust of dentists, cost, anxiety, cultural misunderstandings, concern about standards of hygiene. The type of barrier identified differed between ethnic groups, though mistrust of dentists was common to all groups.

CONCLUSIONS

The findings confirm previous research identifying barriers to the use of dental services. However, for the first time in the United Kingdom, it has been suggested that the nature of the perceived barriers varies across ethnic groups. These findings have implications for attempts to increase use of dental services among individuals from minority ethnic communities.

Expression of AhR and ARNT mRNA in cultured human endometrial explants exposed to TCDD

Endometriosis is a debilitating disease found in 10-15% of reproductive-age women and is characterized by the presence of endometrial tissue outside of the uterus. The present study characterizes the expression of AhR and ARNT mRNA in a human endometrial explant culture model in the absence and presence of TCDD exposure. In a parallel, companion study using this model, TCDD exposure was shown to induce CYP1A1 mRNA, CYP1B1 mRNA, EROD (7-ethoxyresorufin-O-deethylase) activity, and CYP1B1 protein in human endometrial explants. Explants were prepared from specimens obtained at laparoscopy or laparotomy from women undergoing surgery for tubal ligation, endometriosis, or pelvic pain unrelated to endometriosis. These specimens were a subset of the specimens used in the parallel study. The explants were cultured in medium containing 10 nM estradiol (E(2)) or 1 nM estradiol plus 500 nM progesterone (E(2) + P(4)) with or without TCDD (first 24 h). After culture, AhR and ARNT mRNA expression were quantified by RT-PCR. TCDD treatment significantly increased the expression of AhR mRNA, but not ARNT mRNA. The expression of both genes was similar for all individual explants and the ratio of AhR:ARNT mRNA expression across all samples was 1.7 to 1.8. Constitutive AhR mRNA expression was donor age dependent (increasing with age), while ARNT mRNA expression was donor age and tissue phase dependent (increased in older and proliferative phase specimens). Similar to results in the parallel study on expression of CYP1A1 mRNA, CYP1B1 mRNA, EROD activity, and CYP1B1 protein, the presence of endometriosis did not affect the expression of AhR or ARNT mRNA, either constitutively or following TCDD exposure. However, the detection of disease-specific change was limited by small sample size and variability in tissue cycle phase. The human endometrial explant culture model will be useful for future studies of the effects of dioxin-like compounds on human endometrium in relationship to cycle phase, hormonal exposure, and donor age.

Reasons for failure of glyceryl trinitrate treatment of chronic fissure-in-ano: a multivariate analysis

PURPOSE

Although glyceryl trinitrate ointment has become the first-line treatment for chronic anal fissure, healing rates are lower than after lateral internal sphincterotomy. The purpose of this study was to identify which factors are associated with treatment failure of glyceryl trinitrate ointment.

METHODS

All patients who presented with chronic anal fissure from March 1997 to November 1998 were treated with 0.2 percent glyceryl trinitrate ointment. They were prospectively evaluated until healing or lateral internal sphincterotomy occurred, and long-term follow-up was obtained by standardized telephone questionnaire. A Cox model multivariate analysis was used with seven variables to determine significant factors related to healing.

RESULTS

Sixty-four patients (42 men and 22 women; mean age, 37.5 years) with chronic fissure-in-ano were treated with 0.2 percent glyceryl trinitrate ointment. Sentinel piles were observed in 19 patients (29.7 percent). Twenty-six patients (40.6 percent) were healed initially, but 12 (46.2 percent) experienced recurrence. Mean follow-up time was 15.6 (+/-5.5) months. Twenty-nine patients (45.3 percent) had known risk factors for anal fissure, including constipation (n = 21; 32.8 percent), recent childbirth (n = 6; 9.3 percent), colonoscopy (n = 1; 1.6 percent), and anoreceptive intercourse (n = 1; 1.6 percent). Fissures were significantly less likely to heal initially (P < 0.05), more likely to recur (P < 0.05), and more likely to remain unhealed in the long term (P < 0.05) in the presence of a sentinel pile. Fissures with a history of more than six months were less likely to heal initially (P < 0.05).

CONCLUSION

The presence of a sentinel pile adversely affects the outcome of treatment of chronic anal fissures with glyceryl trinitrate ointment, and a long history of the fissure reduces the rate of initial healing. Reasons for these findings are discussed.

A double-blind randomized placebo-controlled trial of oral indoramin to treat chronic anal fissure

BACKGROUND

Indoramin is an alpha1-adrenoceptor antagonist and has been shown to reduce anal resting pressure. Its therapeutic potential has not been explored. The aim of this study was to determine the outcome of treatment with oral indoramin on patients with chronic anal fissure in the setting of a double-blind randomized placebo-controlled trial.

METHODS

Twenty-three patients with chronic anal fissure were computer randomized to receive a 6-week course of oral indoramin (20 mg) or placebo in identical capsules, twice daily and with bulk-forming laxatives. Pain was assessed by a visual analogue scale from 0 to 10. Anal resting pressure, heart rate and blood pressure were recorded. Patients were reviewed 1 h after taking the capsule and at 2, 6 and 12 weeks thereafter.

RESULTS

Fourteen patients were randomized to indoramin and 9 to placebo. Maximum anal resting pressure was reduced from a mean of 96.4 cm H2O (+/- 32) to 67.6 cm H2O (+/- 26), 1 h after indoramin (P=0.02) and there was no significant change after placebo. There were no significant changes in heart rate or blood pressure. Pain was reduced in the placebo group from a score of 4.9 to 2.0 after 6 weeks (P < 0.01) but not in the indoramin group. After 6 weeks, healing had occurred in one (7%) patient in the indoramin group and in 2 (22%) in the placebo group (P > 0.1). After 3 months, the chronic anal fissure in the indoramin group had recurred. The trial was terminated early because of poor healing rates.

CONCLUSION

An oral dose of indoramin (20 mg) administered twice daily reduced anal resting pressure by 30% compared with pretreatment levels but was ineffective in healing chronic anal fissures.

Oophorectomy in primary colorectal cancer

Colorectal cancer is a common cancer affecting women which may metastasize to the ovaries. We present five cases of ovarian metastases requiring surgery and review the debate regarding oophorectomy at the primary resection for colorectal cancer. Although prophylactic oophorectomy has not been proven to affect survival, further surgery for symptomatic ovarian metastases may be avoided and the increased risk of developing primary ovarian cancer is abolished.

Diagnosis of primary HIV-1 infection. Los Angeles County Primary HIV Infection Recruitment Network

BACKGROUND

The optimal approach for diagnosing primary HIV-1 infection has not been defined.

OBJECTIVE

To determine the usefulness of symptoms and virologic tests for diagnosing primary HIV-1 infection.

DESIGN

Prospective cohort study.

SETTING

A teaching hospital in Los Angeles and a university research center in San Diego, California.

PATIENTS

436 patients who had symptoms consistent with primary HIV infection.

MEASUREMENTS

Clinical information and levels of HIV antibody, HIV RNA, and p24 antigen.

RESULTS

Primary infection was diagnosed in 54 patients (12.4%). The sensitivity and specificity of the p24 antigen assay were 88.7% (95% CI, 77.0% to 95.7%) and 100% (CI, 99.3% to 100%), respectively. For the HIV RNA assay, sensitivity was 100% and specificity was 97.4% (CI, 94.9% to 98.9%). Fever, myalgia, rash, night sweats, and arthralgia occurred more frequently in patients with primary infection (P < 0.05).

CONCLUSIONS

No sign or symptom allows targeted screening for primary infection. Although assays for HIV RNA are more sensitive than those for p24 antigen in diagnosing primary infection, they are more expensive and are more likely to yield false-positive results.

Self-assessed oral health status of ethnic minority residents of South London

OBJECTIVE

To determine the self-assessed oral health status of individuals from minority ethnic communities living in South London.

METHOD

A sample of 1,057 individuals from minority ethnic communities (as defined by Office of Censuses and Surveys categories) resident in South London were asked to complete measures of their oral and facial symptoms, the impact of their oral health on their daily functioning and of their satisfaction with the appearance of their teeth and gums.

MEASURES

Self-assessed oral health status was determined by means of two short scales addressing oral symptoms and the impact of oral health on activities of daily living. Satisfaction with the appearance of the teeth and gums was also assessed.

FINDINGS

No significant differences were found between minority ethnic communities in the number of symptoms reported, in the level of impact which such symptoms cause, or in their dissatisfaction with the appearance of their teeth and gums. Reporting of symptoms and impact were mildly though significantly correlated with dissatisfaction.

CONCLUSIONS

There appears to be little difference between ethnic communities in their reporting of oral and facial symptoms, though these groups report higher levels of dissatisfaction with the appearance of their teeth and gums. Social and demographic factors play an important role in determining perceptions of oral health. The findings should be interpreted with caution given the difficulty of sampling minority ethnic communities and the subsequent limited representativeness of the sample.

Adrenocorticotropin (ACTH) and corticosterone secretion by perifused pituitary and adrenal glands from rodents exposed to 2,3,7, 8-tetrachlorodibenzo-p-dioxin (TCDD)

Although in utero maternal stress has been shown to have lasting effects on rodent offspring, fetal effects of chemically-induced alterations of the maternal hypothalamic-pituitary-adrenal axis (HPA) have not been well studied. This study examined the effects of in vivo 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) exposure on pituitary-adrenal function in the male rat, pregnant female rat and pregnant female mouse. The secretion of adrenocorticotropin (ACTH) and corticosterone (CORT) in pituitary and adrenal glands, respectively, was assessed in ex vivo perifusion cultures. Male and pregnant female (gestation day 8) Sprague-Dawley rats were gavaged once with 10 microgram/kg TCDD, pregnant female mice once with 24 microgram/kg TCDD, and euthanized 10 days later. Hemi-pituitary (rat) or whole anterior pituitaries (mice) and right adrenal glands from the same animal were quartered, perifused under baseline and stimulated conditions. In both males and pregnant females, TCDD did not affect corticotropin releasing hormone (CRH)-stimulated ACTH secretion. Neither total pituitary ACTH nor plasma ACTH was altered in either sex or species by TCDD treatment. ACTH-stimulated CORT secretion was not affected by TCDD in either sex or species, and adrenal tissue and plasma CORT levels were unchanged in males and pregnant females by TCDD. However, the plasma ACTH:CORT ratio was decreased about 46% in male rats treated with TCDD. Plasma CORT levels were 23-fold higher and plasma ACTH levels were 1.5-fold higher in pregnant females than in male rats. In male versus female rats, adrenal CORT and anterior pituitary ACTH tissue levels were about 7.5- and 1.75-fold higher and ACTH, respectively. Female mouse adrenal tissue CORT was about 4-fold greater than female rat. The reduced plasma ACTH:CORT ratio in the male rat suggests that TCDD disturbs HPA function. Exposure of male rat to a 5-fold higher dose in earlier studies clearly demonstrated effects of TCDD on male rat HPA. The present study identified substantial HPA performance differences between male and pregnant female rats. The failure to detect a response to TCDD in pregnant female rat and mouse could be a function of both TCDD dose and the high level of secretion of both ACTH and CORT in pregnant animals. For the rat or mouse, a single exposure to TCDD during pregnancy does not appear sufficient to induce maternally-mediated developmental, reproductive and behavioral toxicity via the HPA axis.

Human immunodeficiency virus (HIV) type 1 antibodies in perinatal HIV-1 infection: association with human HIV-1 transmission, infection, and disease progression. For the Women and Infants Transmission Study

Anti -human immunodeficiency virus (HIV) type 1 antibodies in 242 pregnant women and 238 infants were measured at birth and at 1, 2, 4, and 6 months after birth, to estimate their association with perinatal transmission and infant disease progression. Maternal anti-p24 (P=.01) and anti-gp120 (P=.04) antibodies were inversely associated with vertical transmission rates, independent of maternal percentage of CD4 cells, hard drug use, duration of ruptured membranes, serum albumin levels, serum vitamin A levels, and quantitative HIV-1 peripheral mononuclear blood cell culture, but not with maternal plasma immune complex dissociated p24 or HIV-1 RNA copy number, both of which were highly correlated with antibodies. From ages 1-2 months, anti-gp120, -gp41, -p31, and -p66 decayed to a greater extent in infected than in uninfected infants. Infected infants produced anti-p24 antibody by age 2 months, anti-p17 by 4 months, and anti-p41 and anti-gp120 by 6 months. As early as birth, infants with rapid disease progression had lower levels of anti-p24 than did infants whose disease did not rapidly progress, but not independently of HIV-1 RNA levels.

Alpha-1 adrenoceptor blockade: potential new treatment for anal fissures

PURPOSE

Patients with chronic anal fissures are known to have high resting anal pressures that return to normal after successful surgical treatment. Internal anal sphincter activity is increased by sympathetic excitatory innervation via alpha adrenoceptors. The objective of this study was to determine the effect of alpha-1 adrenoceptor blockade on anal sphincter pressure in patients with and without chronic anal fissures.

METHODS

The effect on the anal canal pressure profile of a single oral 20 mg dose of indoramin, an alpha-1 adrenoceptor antagonist, on seven patients with chronic anal fissure and six healthy patients without a fissure was investigated.

RESULTS

Indoramin reduced anal resting pressures in those with anal fissure by a mean of 35.8 percent, from 106.9 +/- 22.15 cm H2O to 68.6 +/- 20.35 cm H2O, and in those without anal fissure by a mean of 39.9 percent, from 84.17 +/- 27.46 cm H2O to 52.17 +/- 24.78 cm H2O, after one hour. This pressure reduction persisted at three hours, and its magnitude is comparable to that obtained after internal sphincterotomy. The pressure reduction occurred over the whole length of the anal canal.

CONCLUSION

It is proposed that alpha-1 adrenoceptor antagonists could be a suitable treatment for chronic anal fissure and other painful conditions where reduction in anal pressure is warranted.

Dental caries and treatment experience of adults from minority ethnic communities living in the South Thames Region, UK

OBJECTIVE

To describe the dental caries and treatment experience of groups of adults from minority ethnic communities living in the South Thames Region of England.

DESIGN

Cross-sectional clinical study.

SETTINGS

Community, religious and educational centres for adults from minority ethnic communities.

PARTICIPANTS

Snowball sample of 928 adults from 44 ethnic groups including: Black Caribbean (141), Black African (134); Pakistani (123); Indian (190); Bangladeshi (78); Chinese/Vietnamese (143) and 119 from other groups.

RESULTS

More participants were dentate or had 18 or more sound and untreated teeth than adults living in the same area (Todd and Lader, 1991). Duration of residence in the United Kingdom predicted caries or treatment experience in the sample as a whole and in Chinese/Vietnamese people. Increased DMFT was predicted by age and by history of visiting a UK dentist in the sample as a whole and in the Black African group.

CONCLUSIONS

Effect of duration of UK residence on presence and extent of caries suggests that oral health may be better among adults from these ethnic minority groups than among the general population. However, the differences can also be attributed to sampling bias and old comparison data. Better sampling strategies are required for research of this type.

HIV-1 genotypic zidovudine drug resistance and the risk of maternal--infant transmission in the women and infants transmission study. The Women and Infants Transmission Study Group

OBJECTIVES

Although the treatment of pregnant women and their infants with zidovudine (ZDV) has been remarkably effective in preventing the perinatal transmission of human HIV-1, many potentially preventable infections still occur. To examine whether the risk of perinatal infection is increased among women who carry ZDV-resistant HIV-1, the role of genotypic ZDV resistance in perinatal transmission was evaluated.

METHODS

The reverse transcriptase (RT) region of clinical isolates from culture supernatants of 142 HIV-1-infected women enrolled in the Women and Infants Transmission Study (WITS), who had been treated with ZDV during pregnancy was sequenced. Results from genotypic sequencing were linked to demographic, laboratory, and obstetrical databases, and the magnitude of association of having consensus drug-resistant HIV-1 RT mutations with transmission was estimated.

RESULTS

Twenty-five per cent (34/142) of maternal isolates had at least one ZDV-associated resistance mutation. A lower CD4 cell percentage and count (P= 0.0001) and higher plasma HIV-1 RNA (P=0.006) were associated with having any ZDV resistance mutation at delivery. Having any RT resistance mutation [odds ratio (OR): 5.16; 95% confidence interval (CI): 1.40, 18.97; P=0 0.01], duration of ruptured membranes [OR: 1.13 (1.02, 1.26) per 4 h duration; P= 0.02], and total lymphocyte count [OR: 1.06 (1.01, 1.10) per 50 cells higher level; P=0.009] were independently associated with transmission in multivariate analysis.

CONCLUSION

Maternal ZDV resistant virus was predictive of transmission, independent of viral load, in these mothers with moderately advanced HIV-1 disease, many of whom had been treated with ZDV before pregnancy.

Nucleoside analogs plus ritonavir in stable antiretroviral therapy-experienced HIV-infected children: a randomized controlled trial. Pediatric AIDS Clinical Trials Group 338 Study Team

CONTEXT

Although protease inhibitors are used routinely in adults with human immunodeficiency virus (HIV) infection, the role of these drugs in the treatment of clinically stable HIV-infected children is not clear.

OBJECTIVE

To evaluate the safety, tolerance, and virologic response produced by a change in antiretroviral therapy in HIV-infected children who were clinically and immunologically stable while receiving previous therapy.

DESIGN

The Pediatric AIDS Clinical Trials Group 338, a multicenter, phase 2, randomized, open-label controlled trial conducted from February 6 to April 30, 1997 (patient entry period); patients were followed up for 48 weeks.

SETTING

Pediatric HIV research clinics in the United States and Puerto Rico.

PATIENTS

Two hundred ninety-seven antiretroviral-experienced, protease inhibitor-naive, clinically stable HIV-infected children aged 2 to 17 years.

INTERVENTIONS

Children were randomized to receive zidovudine, 160 mg/m2 3 times per day, plus lamivudine, 4 mg/kg 2 times per day (n = 100); the same regimen plus ritonavir, 350 mg/m2 2 times per day (n = 100); or ritonavir, 350 mg/m2 2 times per day, and stavudine, 4 mg/kg 2 times per day (n = 97).

MAIN OUTCOME MEASURE

Plasma HIV-1 RNA levels at study weeks 12 and 48, compared among the 3 treatment groups.

RESULTS

At study week 12, 12% of patients in the zidovudine-lamivudine group had undetectable plasma HIV RNA levels (<400 copies/mL) compared with 52% and 54% of patients in the 2- and 3-drug ritonavir-containing groups, respectively (P<.001). Through study week 48, 70% of children continued receiving their ritonavir-containing regimen. At study week 48, 42% of children receiving ritonavir plus 2 nucleosides compared with 27% of those receiving ritonavir and a single nucleoside had undetectable HIV RNA levels (P = .04); however, similar proportions in each group continuing initial therapy had HIV RNA levels of less than 10000 copies/mL (58% vs 48%, respectively; P = .19).

CONCLUSIONS

In our study, change in antiretroviral therapy to a ritonavir-containing regimen was associated with superior virologic response at study week 12 compared with change to a dual nucleoside analog regimen. More children receiving ritonavir in combination with 2 compared with 1 nucleoside analog had undetectable HIV RNA levels at study week 48.

Alterations in cardiac and pulmonary function in pediatric rapid human immunodeficiency virus type 1 disease progressors. Pediatric Pulmonary and Cardiovascular Complications of Vertically Transmitted Human Immunodeficiency Virus Study Group

OBJECTIVE

Infants with human immunodeficiency virus type 1 (HIV-1) can be divided into rapid progressors (RPs) and non-rapid progressors (non-RPs) based on symptoms and immunologic status, but detailed information about cardiac and pulmonary function in RP and non-RP children needs to be adequately described.

METHODOLOGY

Cardiac, pulmonary, and immunologic data and HIV-1 RNA burden were periodically measured in 3 groups: group I, 205 vertically infected children enrolled from 1990 to 1994 and followed through 1996; group II, a prospectively studied cohort enrolled at birth that included 93 infected (group IIa); and 463 noninfected infants (group IIb).

RESULTS

Mean respiratory rates were generally higher in group IIa RP than non-RP children throughout the period of follow-up, achieving statistical signifance at 1 month, 12 months, 24 months, 30 months, and 48 months of follow-up. Non-RP and group IIb (HIV-uninfected children) had similar mean respiratory rates from birth to 5 years of age. Significant differences in mean respiratory rates were found between group I RP and non-RP at 7 age intervals over the first 6 years of life. Mean respiratory rates were higher in RP than in non-RP at <1 year, 2.0 years, 2.5 years, 3.0 years, 3. 5 years, 4.0 years, and 6.0 years of age. Mean heart rates in group IIa RP, non-RP, and group IIb differed at every age. Rapid progressors had higher mean heart rates than non-RP at all ages through 24 months. Mean heart rates at 30 months through 60 months of age were similar for RP and non-RP children. Non-RP children had higher mean heart rates than did group IIb at 8 months, 24 months, 36 months, 42 months, 48 months, 54 months, and 60 months of age. In group I, RP had higher mean heart rates than non-RP at 2.0 years, 2.5 years, 3.0 years, and 4.0 years of age. After 4 years of age, the non-RP and RP had similar mean heart rates. Mean fractional shortening differed between the 3 group II subsets (RP, non-RP, and IIb) at 4, 8, 12, 16, and 20 months of age. Although mean fractional shortening was lower in RP than in non-RP in group II at all time points between 1 and 20 months, the mean fractional shortening was significantly lower in RP only at 8 months when restricting the statistical comparisons to the 2 HIV-infected groups (RP and non-RP). Mean fractional shortening increased in the first 8 months of life followed by a gradual decline through 5 years of age among group IIb children. No significant differences among the 3 groups in mean fractional shortening were detected after 20 months of age. In group I, differences between RP and non-RP in mean fractional shortening were detected at 1.5, 2.0, 2.5, and 3.0 years of age. After 3 years of age, group means for fractional shortening in RP and non-RP did not differ. Because of the limited data from the first months of the group I patients, it could not be determined whether this group experienced the gradual early rise in mean fractional shortening seen in the group II infants. In group IIa, RP had more clinical (eg, oxygen saturation <96%) and chest radiographic abnormalities (eg, cardiomegaly) at 18 months of life. RP also had significantly higher 5-year cumulative mortality than non-RP, higher HIV-1 viral burdens than non-RP, and lower CD8(+) T-cell counts.

CONCLUSIONS

Rapid disease progression in HIV-1- infected infants is associated with significant alterations in heart and lung function: increased respiratory rate, increased heart rate, and decreased fractional shortening. The same children exhibited the anticipated significantly increased 5-year cumulative mortality, increased serum HIV-1 RNA load, and decreased CD8(+) (cytotoxic) T-cell counts. Measurements of cardiopulmonary function in HIV-1-infected children seem to be useful in the total assessment of HIV-1 disease progression.

Maternal and infant factors predicting disease progression in human immunodeficiency virus type 1-infected infants. Women and Infants Transmission Study Group

BACKGROUND

Infants with perinatally acquired human immunodeficiency virus type 1 (HIV-1) infection have widely variable courses. Previous studies showed that a number of maternal and infant factors, when analyzed separately, are associated with infant HIV-1 disease progression. In this study, clincal, virologic, and immunologic characteristics in the mothers and infants were examined together to determine the predictors of disease progression by 18 months of age and the associations with rapid progression during the first 6 months of life.

METHODS

One hundred twenty-two HIV-1-infected women whose infants were HIV-1 infected were identified from the Women and Infants Transmission Study (WITS) cohort. WITS is a longitudinal natural history study of perinatal HIV-1 infection carried out in 6 sites in the continental United States and in Puerto Rico. The women were enrolled during pregnancy and their infants were enrolled at the time of delivery and followed prospectively by a standardized protocol. Virologic and immunologic studies were performed in laboratories certified by National Institutes of Health-sponsored quality assurance programs. Maternal factors in pregnancy were used as potential predictors of infant disease progression (progression to Centers for Disease Control and Prevention [CDC] Clinical Class C disease or death by 18 months of age) or as correlates of progression at <6 months of age. Infant factors defined during the first 6 months of life were used as potential predictors of progression during 6 to 18 months of age and as correlates of progression at <6 months of age.

RESULTS

Progression by 18 months of age occurred in 32% of infants and by 6 months of age in 15%. Maternal characteristics that, by univariate analysis, were significant predictors of infant disease progression by 18 months of age were elevated viral load, depressed CD4(+)%, and depressed vitamin A. CD8(+)%, CD8(+) activation markers, zidovudine (ZDV) use, hard drug use, and gestational age at delivery were not. When examined in a combined multivariate analysis of maternal characteristics, only vitamin A concentration independently predicted infant progression. Infant characteristics during the first 6 months of life that, by univariate analysis, were associated with disease progression included elevated mean viral load at 1 to 6 months of age, depressed CD4(+)%, CDC Clinical Disease Category B, and growth delay. Early HIV-1 culture positivity (<48 hours), CD8(+)%, CD8(+) activation markers, and ZDV use during the first month of life did not predict progression. Multivariate analysis of infant characteristics showed that the only independent predictors were progression to CDC Category B by 6 months of age (odds ratio [OR], 5.80) and mean viral load from 1 to 6 months of age (OR, 1.99). The final combined maternal and infant analysis included the significant maternal and infant characteristics in a multivariate analysis. It showed that factors independently predicting infant progression by 18 months of age were progression to CDC Category B by 6 months of age (OR, 5.80) and elevated mean HIV-1 RNA copy number at 1 to 6 months of age (OR, 1.99). The characteristics associated with rapid progression to CDC Category C disease or death by 6 months of age were also examined. The only maternal characteristic associated with progression by 6 months in multivariate analysis was low maternal CD4(+)%. The infant characteristics associated with progression by 6 months of age in multivariate analysis were depressed mean CD4(+)% from birth through 2 months and the presence of lymphadenopathy, hepatomegaly, or splenomegaly by 3 months. Infant ZDV use was not assocciated with rapid progression.

CONCLUSION

The strongest predictors of progression by 18 months are the presence of moderate clinical symptoms and elevated RNA copy number in the infants in the first 6 months of life. In contrast, progression by 6 months is associated with maternal and infant immun

Evaluation of human immunodeficiency virus (HIV) type 1 load, CD4 T cell level, and clinical class as time-fixed and time-varying markers of disease progression in HIV-1-infected children

Human immunodeficiency virus (HIV) type 1 RNA load, CD4 T cell level, and Centers for Disease Control and Prevention (CDC) clinical class history were measured as potential correlates of a CDC class C diagnosis or death in 165 HIV-1-infected children followed from birth. These covariates were assessed at fixed "landmark" ages from 6 to 24 months and were also assessed as time-varying values. Virus load was associated with progression in all analyses, even after adjusting for immunologic and clinical status. This confirms its importance for monitoring pediatric disease progression. CD4 T cell level was associated with disease progression in time-varying but not in adjusted landmark analysis, suggesting that CD4 cells reflects immediate risk more than long-term risk. The distinction between clinical class B and lower classes is prognostic during the first 18 months of life; class C versus classes N/A/B becomes more important as the patient ages. Virologic, immunologic, and clinical status all provide information regarding disease progression risk.

Reduced antiretroviral drug susceptibility among patients with primary HIV infection

CONTEXT

The transmission of drug-resistant human immunodeficiency virus (HIV) has been documented, but the prevalence of such transmission is unknown.

OBJECTIVE

To assess the spectrum and frequency of antiretroviral susceptibility among subjects with primary HIV infection.

DESIGN, SETTING, AND PATIENTS

Retrospective analysis of 141 subjects identified from clinical research centers in 5 major metropolitan areas, enrolled from 1989 to 1998, with HIV seroconversion within the preceding 12 months and no more than 7 days' prior antiretroviral (ARV) therapy.

MAIN OUTCOME MEASURES

Phenotypic and genotypic ARV susceptibility of HIV from plasma samples.

RESULTS

The transmission of drug-resistant HIV as assessed by a greater than 10-fold reduction in ARV susceptibility to 1 or more drugs was observed in 3 (2%) of 141 subjects, including to a nonnucleoside reverse transcriptase inhibitor in 1 patient and to a nucleoside reverse transcriptase inhibitor and a protease inhibitor in 2 patients. Population-based sequence analysis of these 3 samples identified multidrug-resistance mutations in reverse transcriptase (M184V, T215Y, K219K/R) and protease (L101/V, K20R, M361, M46I, G48V, L63P, A71T, V771, V82T, 184V, L90M) in the 2 latter patient samples, along with numerous polymorphisms. A reduction in susceptibility of greater than 2.5- to 10-fold to 1 or more drugs was observed in viral isolates from 36 patients (26%). Sequence analysis of these 36 samples identified well-characterized drug resistance mutation in reverse transcriptase and protease in only 1 of these patients.

CONCLUSIONS

Reductions in drug susceptibility of more than 10-fold were rare among this cohort of recently HIV-infected subjects and were distributed among each of the 3 major classes of ARV drugs tested. Reductions in susceptibility of more than 2.5- to 10-fold to certain ARV drugs of unknown clinical significance were highly prevalent among newly infected patients. Resistance testing may be warranted to monitor the frequency of drug resistance over time and to assess the potential for geographic variability.

Maternal levels of plasma human immunodeficiency virus type 1 RNA and the risk of perinatal transmission. Women and Infants Transmission Study Group

BACKGROUND

The importance of plasma levels of human immunodeficiency virus type 1 (HIV-1) RNA in pregnant women in relation to the other factors known to influence the risk of transmission of infection to their infants is incompletely defined. We studied the relation of maternal plasma HIV-1 RNA levels to the risk of perinatal transmission and the timing of transmission.

METHODS

We measured plasma HIV-1 RNA serially in 552 women with HIV-1 infection who had singleton pregnancies. The status of infection in their infants was assessed by culture of blood and further classified as early (if a culture of blood obtained within the first two days of life was positive) or late (if a culture of blood obtained in the first seven days of life was negative but subsequent cultures were positive). The rates of transmission at various levels of maternal plasma HIV-1 RNA were analyzed by tests for trend, with adjustment for covariates by stratification and logistic regression.

RESULTS

Increasing geometric mean levels of plasma HIV-1 RNA were associated with increasing rates of transmission: the rate was 0 percent among women with less than 1000 copies per milliliter (0 of 57), 16.6 percent among women with 1000 to 10,000 copies per milliliter (32 of 193), 21.3 percent among women with 10,001 to 50,000 copies per milliliter (39 of 183), 30.9 percent among women with 50,001 to 100,000 copies per milliliter (17 of 55), and 40.6 percent among women with more than 100,000 copies per milliliter (26 of 64) (P<0.001). The treatment status of one woman was unknown. The highest rate of transmission was among women whose plasma HIV-1 RNA levels exceeded 100,000 copies per milliliter and who had not received zidovudine (19 of 30 women, 63.3 percent). Neither higher HIV-1 RNA levels early in pregnancy nor higher levels late in pregnancy were associated with the timing of infection in the infants.

CONCLUSIONS

In pregnant women with HIV-1 infection the level of plasma HIV-1 RNA predicts the risk but not the timing of transmission of HIV-1 to their infants.

Vitamin A deficiency and other nutritional indices during pregnancy in human immunodeficiency virus infection: prevalence, clinical correlates, and outcome. Women and Infants Transmission Study Group

Vitamin A levels in plasma and other nutritional indices were measured during pregnancy for 449 women enrolled in a multicenter cohort study of mother-to-infant transmission of human immunodeficiency virus type 1 (HIV-1). During the third trimester, 29.6% of the women had low (20 to <30 microg/dL) and 11.1% had very low (<20 microg/dL) vitamin A levels. Vitamin A and body mass index, serum albumin levels, and hemoglobin levels were weakly correlated. After adjustment for other covariates, women with low and very low vitamin A levels before the third trimester were more likely to deliver infants with low birth weight (<2500 g) than were those with higher levels (odds ratio [OR], 4.58; 95% confidence interval [CI], 1.57-13.4; and OR, 6.99; 95% CI, 1.09-45.0, respectively). However, there was no statistically significant association between vitamin A level and mother-to-infant transmission of HIV-1. Anemia and low body mass index before the third trimester were associated with an increased risk of transmission in univariate analyses but not in multivariate analyses.

Cytomegalovirus infection and HIV-1 disease progression in infants born to HIV-1-infected women. Pediatric Pulmonary and Cardiovascular Complications of Vertically Transmitted HIV Infection Study Group

BACKGROUND AND METHODS

Cytomegalovirus (CMV) has been implicated as a cofactor in the progression of human immunodeficiency virus type 1 (HIV-1) disease. We assessed 440 infants (75 of whom were HIV-1-infected and 365 of whom were not) who had known CMV status and were born to HIV-1-infected women and who were followed prospectively. HIV-1 disease progression was defined as the presence of class C symptoms (according to the criteria of the Centers for Disease Control and Prevention [CDC]) or CD4 counts of less than 750 cells per cubic millimeter by 1 year of age and less than 500 cells per cubic millimeter by 18 months of age.

RESULTS

At birth the frequency of CMV infection was similar in the HIV-1-infected and HIV-1-uninfected infants (4.3 percent and 4.5 percent, respectively), but the HIV-1-infected infants had a higher rate of CMV infection at six months of age (39.9 percent vs. 15.3 percent, P=0.001) and continued to have a higher rate of CMV infection through four years of age (P=0.04). By 18 months of age, the infants with both infections had higher rates of HIV-1 disease progression (70.0 percent vs. 30.4 percent, P=0.001), CDC class C symptoms or death (52.5 percent vs. 21.7 percent, P=0.008), and impaired brain growth or progressive motor deficits (35.6 percent vs. 8.7 percent, P=0.005) than infants infected only with HIV-1. In a Cox regression analysis, CMV infection was associated with an increased risk of HIV-1 disease progression (relative risk, 2.59; 95 percent confidence interval, 1.13 to 5.95). Among children infected with HIV-1 alone, but not among those infected with both viruses, children with rapid progression of HIV-1 disease had higher mean levels of HIV-1 RNA than those with slower or no progression of disease.

CONCLUSIONS

HIV-1-infected infants who acquire CMV infection in the first 18 months of life have a significantly higher rate of disease progression and central nervous system disease than those infected with HIV-1 alone.

Natural history of primary Epstein-Barr virus infection in children of mothers infected with human immunodeficiency virus type 1

The natural history of Epstein-Barr virus (EBV) infection in 556 infants born to 517 human immunodeficiency virus (HIV) type 1-infected mothers was studied in a prospective, multicenter, cohort study. HIV-1-infected children had a cumulative EBV infection rate similar to HIV-1-uninfected children at age 3 years (77.8% vs. 84. 9%) but had more frequent oropharyngeal EBV shedding (50.4% vs. 28. 2%; P<.001). The probability of shedding decreased with longer time from EBV seroconversion and was similar to that of HIV-1-uninfected children 3 years after seroconversion. HIV-1-infected children identified as rapid progressors shed EBV more frequently than nonrapid progressors (69.4% vs.41.0%; P=.01). HIV-1-infected children with EBV infection had higher mean CD8 cell counts. EBV infection did not have an independent effect on mean CD4 cell counts, percent CD4, IgG levels, HIV-1 RNA levels, lymphadenopathy, hepatomegaly, or splenomegaly. Early EBV infection is common in children born to HIV-1-infected mothers. Children with rapidly progressive HIV-1 disease have more frequent EBV shedding.

Adverse reproductive outcomes in the transgenic Ah receptor-deficient mouse

The aryl hydrocarbon receptor (AHR) is a transcriptional regulatory protein that binds to upstream DNA response elements of target genes. Activation of the AHR by binding of ligands such as polyhalogenated dioxins, furans, and PCBs is associated with a wide range of adverse biological outcomes, including cancer, immune deficiencies, embryo/fetotoxicity, and reproductive toxicity. Investigations of the diverse biological responses mediated by the AHR led to production of a transgenic mouse in which the gene coding for the AhR was inactivated. AHR-deficient mice were fertile and at maturity exhibited immune system impairment and hepatic fibrosis. Our laboratory received several of these homozygous knockout (-/-) mice and mated them with wild-type (+/+) C57BL/6N mice to generate large numbers of heterozygotes (+/-). The -/- males were then mated with a total of 45 heterozygous +/- females. Offspring of these matings were genotyped and mated in all genotypic combinations. Although male and female -/- adults were fertile, the -/- females had difficulty maintaining conceptuses during pregnancy, surviving pregnancy and lactation, and rearing pups to weaning. Only 46% of the 39 pregnant -/- females successfully raised pups to weaning. The -/- pups showed poor survival during lactation (average death rate per litter was 16%) and after weaning (26.5% of the 230 weaned -/- pups died within 2 weeks). Only 39% of the implantations in uteri of -/- dams resulted in offspring surviving to Postnatal Day 45. Across all litters the sex ratios and genotypic frequencies were comparable to expected values. Reproductive success was adversely affected in Ahr-null females and conceptuses. Additional study is needed to reveal the etiology of these effects.

Obstetric and newborn outcomes in a cohort of HIV-infected pregnant women: a report of the women and infants transmission study

OBJECTIVE

To determine obstetric and neonatal outcomes in a cohort of HIV-infected pregnant women and to assess whether HIV-related immunosuppression increases the risk of adverse outcomes of pregnancy.

METHODS

Between 1989 and 1994, interview, physical examination, laboratory, and medical record data were prospectively collected from HIV-infected pregnant women and on their newborns. Factors associated with adverse pregnancy outcome and HIV disease status were correlated with pregnancy outcome using logistic regression analysis.

RESULTS

634 women delivered after 24 weeks of gestation. Preterm birth, low birth weight, and small-for-gestational-age neonates occurred in 20.5%, 18.9%, and 24.0% of pregnancies, respectively. Factors associated with low birth weight were CD4 percentage <14%, history of adverse pregnancy outcome, pediatric HIV infection, bleeding during pregnancy, and Trichomonas infection. Preterm birth was associated with CD4 percentage <14%, a history of adverse pregnancy outcome, and bleeding during pregnancy. Being small for gestational age was associated with maternal hard drug use during pregnancy, Trichomonas infection, history of adverse pregnancy outcome, and hypertension.

CONCLUSIONS

Adverse pregnancy outcomes are common for HIV-infected women and are associated with low maternal CD4 percentage and pediatric HIV infection. Preterm birth, low birth weight, and small-for-gestational-age ranking, however, are also associated with previously recognized sociodemographic and obstetric factors that are not unique to HIV infection.

Development of a morphologically-based scoring system for postimplantation New Zealand White rabbit embryos

Rodent whole-embryo culture (WEC) systems are well-established, as are several corresponding morphological scoring systems. Recently, WEC techniques for rabbits have been developed, creating the need for a morphological evaluation system in this species. Consequently, we developed a gestational-age-based quantitative morphology evaluation system for rabbit embryos. Detailed descriptions of 21 embryonic structures, as collected from gestational day (gd) 9-13 rabbit embryos, formed the basis for this evaluation system. These descriptions were then developed into specific criteria for assigning numerical scores to quantify the degree of development of each embryonic structure. The overall morphologic score was calculated as the average of the individual structure scores. To make the system as informative as possible, the numerical scale of the scoring system was gestationally age-based (i.e., range of potential scores was 9.0-13.0). The scoring system was then applied in the evaluation of New Zealand White (NZW) rabbit embryos explanted on gd 9 and cultured for 48 hr. Embryos grown in vitro developed normally, but at a slightly slower rate in vitro than in vivo, as evidenced by the lower morphology score (10.4 in vitro, 11.0 in vivo) and measures of growth (somite number, total protein, and head length). This work firmly establishes the normal archetype of embryonic development in the gd 9-13 NZW rabbit and provides an important tool for the advancement of mechanistic studies of rabbit embryos developing both in vivo and in vitro.