Rescinding evidence-based care and practices during the initial COVID-19 outbreak in the United States: a qualitative study of the experiences of lactation support providers

Background

The COVID-19 pandemic disrupted healthcare systems and services including along the childbearing continuum. The aim of this study was to explore the experiences and perceptions of professional lactation support providers who cared for breastfeeding families during the early months of the pandemic (March 2020 - August 2020) in the United States.

Design/methods

We conducted a qualitative survey among active lactation support providers in the United States. Eligible participants spoke English, were Certified Lactation Counselors who maintained an active certification and who provided lactation care and services prior to and after the onset of the COVID-19 pandemic. Participants were recruited via email from the national database of Certified Lactation Counselors obtained from the national certification body. All ten Health and Human Service regions of the United States were included. Demographic data was collected on each respondent. Qualitative survey responses were analyzed thematically following the framework method.

Findings

Six-hundred and seventy-four (674) Certified Lactation Counselors responded to the survey from June to July of 2022. Their responses fell within the overarching theme of rescinding evidence-based care and practices that had been in place prior to the pandemic. Affected care practices included the insertion of limits on access to care and insinuating stigma and bias based on COVID-19 status. Irregular appointment schedules and staffing shortages also affected care. Participants reported that separation of the mother and their infant became the norm. Decisions made by management seemed to be grounded in fear and uncertainty, rather than on the evidence-based principles that had been in place prior to the pandemic.

Conclusion

A lack of coordination, consistency and support, along with fear of the unknown, troubled lactation support providers and impacted their ability to provide evidence-based care and to maintain access to care for all families. The findings of the survey and analysis underscore the importance of adequately preparing for future public health crises by determining how evidence-based care and practices can be preserved in emergent situations.

Skin-to-skin contact after birth: developing a research and practice guideline

AIM

Skin-to-skin contact immediately after birth is recognized as an evidence-based best practice and an acknowledged contributor to improved short- and long-term health outcomes including decreased infant mortality. However, implementation and definition of skin-to-skin contact is inconsistent in both practice and research studies. This project utilized the World Health Organization guideline process to clarify best practice and improve the consistency of application.

METHODS

The rigorous guideline development process combines a systematic review with acumen and judgement of experts with a wide range of credentials and experience.

RESULTS

The developed guideline received "strong recommendation" from the Expert Panel. The result concluded that there was a high level of confidence in the evidence and that the practice is not resource intensive. Research gaps were identified and areas for continued work delineated.

CONCLUSION

The World Health Organization guideline development process reached the conclusion immediate, continuous, uninterrupted skin-to-skin contact should be the standard of care for all mothers and all babies (from 1000 grams with experienced staff if assistance is needed), after all modes of birth. Delaying non-essential routine care in favor of uninterrupted skin-to-skin contact after birth has been shown to be safe and allows for progression of newborns through their instinctive behaviors.

Abstract OT2-1-01: A personalized approach to understanding the development of radiation-induced fatigue

Background

Fatigue, a common complication of radiation therapy, can impact patients’ quality of life and ability to engage in their cancer treatments. The pathogenesis of radiation-induced fatigue is unclear. This lack of clear understanding has hindered the development of treatment strategies to overcome this morbidity. The purpose of our exploratory, non-randomized, prospective study is to investigate the factors associated with development of radiation-induced fatigue in women with early breast cancer. Our study is based on the hypotheses that adjuvant radiation therapy given to women with breast cancer for local disease control causes tissue damage by apoptosis and inflammation. This leads to increased levels of inflammatory cytokines and biomarkers of apoptosis. This inflammatory cascade differentially induces fatigue in patients depending on their baseline psychological profile.

Trial design

Existing patient flow in the radiation oncology division will be utilized to screen eligible subjects. All subjects will assessed at five different time points, beginning immediately before radiation therapy through 1 year after completion of therapy. Detailed clinical evaluation of skin toxicity (RTOG acute toxicity criteria) and laboratory parameters assessing anemia, cardiac and hepatic toxicity will be performed. Comprehensive psychological assessment will be done using questionnaires for fatigue, distress, depression, sleep, quality of life and pain. Buccal mucosa swabs will be obtained for genetic analysis in future studies.

Selection criteria

Inclusion: Women with breast cancer undergoing radiation therapy for breast conservation

Exclusion: Prior non-breast malignancy with active treatment (radiation or chemotherapy) within 1 year of enrolment on the study

Specific aims

1. To measure the severity of radiation-induced tissue damage

2. To measure circulating markers of apoptosis (caspase 3 p17) and inflammation

3. To establish a baseline psychological profile for each subject prior to start of radiation and determine temporal changes during the course of radiation therapy.

4. To determine the correlation between goals 1, 2 and 3.

5. To propose interventions for reducing radiation-induced fatigue which will be evaluated in a future study.

Statistical methods

The association between fatigue and severity of tissue toxicity (Yes vs. No) will be assessed using chi-square tests (eg, row mean score test). ANOVA will be used to compare mean visual analogue scales (VAS) and psychological questionnaire scores across the levels of the tissue toxicity scale. Mean log cytokine levels will be compared across levels of the dermatitis scale using ANOVA. The association between cytokines and fatigue will be assessed using correlation (eg, VAS) and two-group t-tests (eg, Yes vs. No) depending on which fatigue outcome is used. Two statistical models will be used to assess fatigue and its relationship to dermatitis, cytokine level, and their interactive effects using logistic regression (for dichotomous) and OLS regression (for VAS) approaches.

Present accrual: 0; Study initiation planned for July 1, 2013

Target accrual : 100.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr OT2-1-01.

Cyclooxygenase expression and platelet function in healthy dogs receiving low-dose aspirin

BACKGROUND

Low-dose aspirin is used to prevent thromboembolic complications in dogs, but some animals are nonresponsive to the antiplatelet effects of aspirin ("aspirin resistance").

HYPOTHESIS/OBJECTIVES

That low-dose aspirin would inhibit platelet function, decrease thromboxane synthesis, and alter platelet cyclooxygenase (COX) expression.

ANIMALS

Twenty-four healthy dogs.

METHODS

A repeated measures study. Platelet function (PFA-100 closure time, collagen/epinephrine), platelet COX-1 and COX-2 expression, and urine 11-dehydro-thromboxane B(2) (11-dTXB(2)) were evaluated before and during aspirin administration (1 mg/kg Q24 hours PO, 10 days). Based on prolongation of closure times after aspirin administration, dogs were divided into categories according to aspirin responsiveness: responders, nonresponders, and inconsistent responders.

RESULTS

Low-dose aspirin increased closure times significantly (62% by Day 10, P < .001), with an equal distribution among aspirin responsiveness categories, 8 dogs per group. Platelet COX-1 mean fluorescent intensity (MFI) increased significantly during treatment, 13% on Day 3 (range, -29.7-136.1%) (P = .047) and 72% on Day 10 (range, -0.37-210%) (P < .001). Platelet COX-2 MFI increased significantly by 34% (range, -29.2-270%) on Day 3 (P = .003) and 74% (range, -19.7-226%) on Day 10 (P < .001). Urinary 11-dTXB(2) concentrations significantly (P = .005, P < .001) decreased at both time points. There was no difference between aspirin responsiveness and either platelet COX expression or thromboxane production.

CONCLUSIONS AND CLINICAL IMPORTANCE

Low-dose aspirin consistently inhibits platelet function in approximately one-third of healthy dogs, despite decreased thromboxane synthesis and increased platelet COX expression in most dogs. COX isoform expression before treatment did not predict aspirin resistance.

Double blind placebo control trial of large neutral amino acids in treatment of PKU: effect on blood phenylalanine

Large neutral amino acids (LNAA) have been used on a limited number of patients with phenylketonuria (PKU) with the purpose of decreasing the influx of phenylalanine (Phe) to the brain. In an open-label study using LNAA, a surprising decline of blood Phe concentration was found in patients with PKU in metabolic treatment centres in Russia, the Ukraine, and the United States. To validate the data obtained from this trial, a short-term double-blind placebo control study was done using LNAA in patients with PKU, with the participation of three additional metabolic centres--Milan, Padua and Rio de Janeiro. The results of the short trial showed significant lowering of blood Phe concentration by an average of 39% from baseline. The data from the double-blind placebo control are encouraging, establishing proof of principle of the role of orally administered LNAA in lowering blood Phe concentrations in patients with PKU. Long-term studies will be needed to validate the acceptability, efficacy and safety of such treatment.

Large neutral amino acids in the treatment of phenylketonuria (PKU)

Large neutral amino acids (LNAAs) have been used on a limited number of patients with phenylketonuria (PKU) with the purpose of decreasing the influx of phenylalanine (Phe) to the brain. In earlier studies on mice with PKU (ENU(2)/ENU(2)), LNAAs were given and a surprising decline in blood Phe concentrations was observed. The formula used in the mouse experiment (PreKUnil) lacked lysine. Therefore, a new formulation of LNAAs (NeoPhe) was developed, introducing changes in the concentration of some amino acids and adding lysine, so that such a mixture could be used in humans. The new formula was found to be effective in reducing blood Phe concentration in mice by about 50% of the elevated levels. Patients with PKU were given LNAAs and blood Phe concentrations were determined in an open-label study. Three centers--in Russia, the Ukraine and the USA--took part in the study. NeoPhe was given at 0.5 g/kg per day in three divided doses to eight subjects with PKU and at 1.0 g/kg per day to three patients, for one week. The NeoPhe resulted in decrease of elevated blood Phe by 50% in both groups. The preliminary data from this study are encouraging and a double blind placebo-controlled trial will be required to show long-term efficacy and tolerance of LNAAs in the treatment of PKU.

Hepatitis C seroprevalence among newly incarcerated inmates in the Texas correctional system

The seroprevalence of hepatitis C (HCV) infection was examined among a sample of incoming inmates in the Texas Department of Criminal Justice (TDCJ) prison system. Rates were compared across demographic factors and three types of prison facilities: substance abuse felony punishment units (SAFPs), state jails and prisons. The study sample consisted of 3712 incoming inmates incarcerated for any duration, dating from 1 November 1998 to 31 May 1999. Among males, inmates entering SAFPs and state jails had comparable HCV infection rates (29.7 and 27.0%, respectively) to those entering prisons (27.3%). Among females, inmates entering prisons had a higher rate of infection (48.6%) than those entering state jails (35.1%) or SAFPs (38.3%). For both genders, blacks exhibited a lower overall infection rate than whites and Hispanics, and HCV seroprevalence increased in a stepwise fashion with age. All subgroups of TDCJ inmates, including those held in alternative correctional facilities, exhibited HCV infection rates that were comparable with previous reports of inmate populations, but dramatically higher than general community samples. Given that most inmates held in alternative facilities will return to the general community in a short period of time, understanding the HCV infection rates in these subgroups holds particular public health relevance.

Anti-depressant prescribing patterns for prison inmates with depressive disorders

BACKGROUND

Although prison inmates are reported to exhibit elevated rates of depressive disorders, little is known about anti-depressant prescribing patterns in correctional institutions.

METHODS

The study population consisted of 5305 Texas Department of Criminal Justice (TDCJ) inmates who were diagnosed with one of three depressive disorders: major depression, dysthymia, and bipolar disorder (excluding those with manic episodes only). Information on medical conditions, sociodemographic factors, and pharmacotherapy was obtained from an institution-wide medical information system.

RESULTS

In 1998, 78.2% of all inmates diagnosed with depressive disorders were treated with antidepressant medication. Of these, 47.3% were treated exclusively with tricyclic anti-depressants (TCA); 30.9% were treated with selective serotonin re-uptake inhibitors (SSRI); and 21.8% were not treated with any form of anti-depressant medication. Prescribing patterns varied substantially according to a number of sociodemographic factors under study.

LIMITATIONS

Because the present study relied on retrospective, clinical data, the investigators had limited ability to assess: specific symptomatology for each diagnosed depressive condition under study; socio-economic status, pre-incarceration access to health care; and the overall reliability and validity of the data.

CONCLUSION

The proportion of prison inmates with depressive disorders who receive appropriate medication management is substantially higher than that reported among similarly diagnosed nonincarcerated samples. It will be important, however, for future investigators to examine the sources of sociodemographic variation in treatment patterns found in the present study.

Usefulness of genetic susceptibility and biomarkers for evaluation of environmental health risk

Recent attention is focused on understanding the genetic basis for individual susceptibility to the development of chronic disease. An emphasis is concentrated on establishing an association between inheritance of polymorphic chemical metabolizing genes and development of environmental cancer (e.g., lung cancer among cigarette smokers). The early reports of such associations have been very encouraging. However, some reported positive associations were not substantiated in subsequent studies using larger sample sizes and different ethnic populations. In this review, some confounding factors that contribute to the discrepancies are presented (e.g., ethnic-dependent distribution of variant gene alleles, differential expression of metabolizing genes, and inadequate study design). It is possible that the precision of the association can be improved if the mentioned investigations are complemented with concurrent studies of biological activities/effects. The usefulness of integrating metabolic susceptibility with biomarker measurement for understanding the development of lung cancers is presented. The importance of using adequate sample size and experimental design is emphasized. Development of a reliable approach for prediction of environmental disease not only will provide fundamental information regarding the genetic basis of human disease but will be useful for reducing disease burden in the population and for advancing patient care. Environ. Mol. Mutagen. 37:215-225, 2001. &copy 2001 Wiley-Liss, Inc.

Highly active antiretroviral therapy improves survival of HIV-infected hemodialysis patients

Human immunodeficiency virus (HIV)-infected hemodialysis (HD) patients have a very high morbidity and mortality. Reports from the last few years have suggested that highly active antiretroviral therapy (HAART) has remarkably improved the survival of HIV-infected patients. To determine whether the beneficial effects of HAART have also extended to HIV-infected HD patients, we retrospectively evaluated the survival of all HIV-infected patients who underwent chronic maintenance HD between 1992 and 1999 at our institution. Twenty-two HIV-infected patients were started on chronic maintenance HD at our institute during this period. The mean age of the patients was 36 +/- 9 (SD) years (range, 21 to 58 years). Seven patients were treated with only one or two antiretroviral drugs (patients 1 and 5 were administered two antiretroviral drugs), and the remaining 15 patients were treated with HAART (three antiretroviral drugs or more). Fifty-seven percent (4 of 7 patients) of the patients on suboptimal therapy died after a mean time on HD therapy of 13 +/- 10 months compared with only 20% (3 of 15 patients) of those on HAART after a mean period on HD therapy of 28 +/- 17 months. Plasma viral load was significantly less in patients on HAART compared with patients on suboptimal therapy (3.35 +/- 0.92 versus 4.63 +/- 1.3 log(10) copies/mL; P = 0.03). Patients with diagnoses other then HIV-associated nephropathy and those on HAART had statistically longer survival times (P = 0.02 and P = 0.04, respectively). We conclude that HAART is successful in suppressing viral load in HIV-infected HD patients, and the survival of HIV-infected HD patients on HAART is better than that of patients on suboptimal antiretroviral therapy.

Telemedicine screening of glaucoma

OBJECTIVES

Glaucoma is a major cause of blindness. More than 80,000 Americans suffer permanent vision loss from the disease. Widespread screening is fundamental in limiting the incidence of glaucoma-associated blindness. This pilot study explored the use of stereo digital images taken at a primary care center for telemedicine review by an off-site specialist as a means of screening for glaucoma.

MATERIALS AND METHODS

Thirty-two diabetic patients were screened at a family medicine clinic. None had previously been diagnosed with glaucoma. A senior optometry student took stereoscopic digital and 35-mm optic disc photographs with a nonmydriatic retinal camera. The digital images were forwarded to a remote ophthalmologist for review. The conventional color stereo slide pairs of the same eyes were subsequently reviewed for comparison. Agreement on signs of glaucomatous disc changes between the two imaging systems was analyzed.

RESULTS

Twenty-six of 32 eyes' digital and 35-mm photographs were analyzed. Six of 32 eyes (18.8%) could not be compared due to lack of matching 35-mm slides or digital images. Out of 26 eyes, lamina cribosa visibility was undeterminable in 8 eyes' digital images and 3 other eyes' 35-mm slides. Agreement among digital images and 35-mm slides of the remaining eyes was: 100%-vertical elongation, barring of vessels, bayoneting of vessels, and drance hemorrhage; 96.2%-focus notching of rim and rim pallor; 93.3%-lamina cribosa visability; 92. 3%-overpass cupping; 88.5%-focal enlargement; 84.6%-parapapillary halo; 80%-nerve fiber visibility; 65.4%-parapapillary atrophy. Parapapillary halo (p = 0.046) and nerve fiber layer visibility (p = 0.18) were detected on some 35-mm slides but not seen on matching digital views.

CONCLUSION

Evaluations of cup-to-disc ratio (C/D) using both methods were in general agreement. However, some digital images were noted as too dark for assessing fine glaucomatous disc changes. Stereo digital images taken with a nonmydriatic camera by nonophthalmic photographers is a promising alternative for glaucoma screening in primary care settings. Telemedicine offers efficient communications with off-site glaucoma specialists. A larger study population is necessary to determine the overall effectiveness of using stereo digital imagery and teleophthalmology for glaucoma screening.

Comparison of once- and twice-daily dosing of fluticasone propionate 200 micrograms per day administered by diskus device in patients with asthma treated with or without inhaled corticosteroids

BACKGROUND

There are limited published data regarding the efficacy of once- versus twice-daily administration of flutica-sone propionate.

OBJECTIVE

Our purpose was to evaluate the effectiveness of fluticasone propionate powder 200 microg/d administered as a once- or twice-daily dosage regimen in patients who were currently being treated with bronchodilators only (BD patients) and in patients who required inhaled corticosteroids for maintenance treatment of asthma (ICS patients).

METHODS

Five hundred seventy patients were randomly assigned to receive one of the following inhaled treatments through the Diskus device (Glaxo Wellcome, Research Triangle Park, NC) for 12 weeks: fluticasone propionate 100 microg twice daily (FP100BID) or 200 microg once daily (FP200QD) or placebo.

RESULTS

BD patients treated with FP100BID, FP200QD, and placebo had mean increases in FEV(1) from baseline to end point of 0. 49 L, 0.37 L, and 0.21 L, respectively (P <.001, FP100BID vs placebo; P =.05, FP200QD vs placebo). ICS patients treated with FP100BID and FP200QD had mean increases in FEV(1) of 0.27 L and 0.11 L, respectively, compared with a decrease in FEV(1) of -0.08 L with placebo (P <.001, FP100BID vs placebo; P =.023, FP200QD vs placebo). BD patients treated with FP100BID and FP200QD had mean increases in morning peak expiratory flow from baseline to end point of 31 L/min and 27 L/min, respectively, compared with a 1 L/min increase in patients treated with placebo. ICS patients treated with FP100BID had a mean increase in morning peak expiratory flow (from baseline to end point) of 18 L/min compared with mean decreases of -3 L/min and -12 L/min in the FP200QD and placebo groups, respectively. More patients were withdrawn from placebo (26% and 48%, in BD and ICS patients, respectively) than from fluticasone propionate (7%-9% [BID-QD] and 18%-32% [BID-QD], in BD and ICS patients, respectively) because of failure to meet predetermined asthma stability criteria.

CONCLUSION

The efficacies of FP100BID and FP200QD were comparable with regard to improvement in pulmonary function and asthma stability in BD patients. In ICS patients, asthma control was maintained with FP200QD, whereas FP100BID provided greater improvements in pulmonary function and asthma stability.

Prevalence of HIV-associated nephropathy in autopsies of HIV-infected patients

Previous studies have reported that approximately 10% of the patients with human immunodeficiency virus (HIV) infection develop HIV-associated nephropathy (HIVAN). However, over the last decade, morbidity and mortality as a result of HIV-1 infection has remarkably decreased with the availability of potent new antiretroviral drugs. We therefore determined the prevalence of HIVAN from autopsy data of HIV-infected patients in more recent years (1992 to 1997). Autopsy reports of 389 patients were reviewed. In reports suggestive of possible HIVAN, slides of renal tissue were retrieved and reviewed again to ensure appropriate classification. The criteria for the diagnosis of HIVAN were focal segmental glomerulosclerosis with collapse of the glomerular tuft in some glomeruli, extensive tubular ectasia, and significant tubulointerstitial disease. Of 389 autopsy reports, 54% of the patients were black, 35% were white, and 11% were Hispanic. Thirty-three percent of the patients had a history of intravenous drug abuse. The mean CD4 count of the patients was 54 +/- 91/microL (mean +/- SD). In 27 cases, typical features of HIVAN were found based on the criteria used, accounting for an overall HIVAN prevalence of 6.9% (27 of 389 autopsies). Because the overwhelming majority of these patients were black (93%), the prevalence in blacks was 12% (25 of 209 autopsies). We conclude that although mortality and morbidity from HIV infection is decreasing, HIVAN remains an important complication of HIV infection in blacks, even in recent years.

Immunologic predictors of HIV-related survival among Texas prison inmates

Research indicates that being incarcerated adversely affects overall health status. Because HIV-infection is a growing problem among the U.S. prison population, understanding how incarceration affects HIV-related survival holds particular clinical and public health relevance. Moreover, while the prognostic roles of CD4 and CD8 lymphocyte count have been well documented in noninstitutionalized populations, little is known about how these factors operate to predict survival among prison populations. The present study examined immunologic determinants of HIV-related survival in a cohort of 752 Texas Department of Criminal Justice (TDCJ) inmates who were treated for HIV/AIDS between 1993 and 1996 at a large south-western medical center. Survival analysis using proportional hazards modeling showed that: (1) the prognostic role of CD4 count among inmates was similar to previous findings among non-incarcerated populations; (2) the prognostic role of CD8 count was slightly weaker than that previously reported for non-incarcerated populations; and (3) inmates who exhibited high levels of both CD4 and CD8 count had a survival advantage over those who had a high score on only one of the two factors.

Sub-Tenon's injection for local anesthesia in posterior segment surgery

OBJECTIVE

To determine whether the sub-Tenon's parabulbar approach for local anesthesia is a safe and effective choice for posterior segment surgery.

DESIGN

Prospective, noncomparative case series.

PARTICIPANTS

Two hundred seventy-six consecutive patients underwent posterior segment surgery at the University of Texas Medical Branch.

INTERVENTION

Two hundred patients received sub-Tenon's parabulbar anesthesia containing an 11 -ml mixture of 5-ml 2% lidocaine (Xylocaine), 5-ml 0.5% bupivacaine (Marcaine), and 1 ml of 150 hyaluronidase (Wydase) units as primary anesthesia. The method did not involve a separate transcutaneous lid nerve or subconjunctival injection.

MAIN OUTCOME MEASURES

The proportion of cases receiving supplementation (significant intravenous anesthesia, intraoperative local anesthesia, or both) was estimated. Its relationship to duration of surgery and surgical procedures deemed painful was assessed. Surgery lasting 3 hours or more was considered a long duration. Both scleral buckle and cryotherapy were considered painful procedures. The proportion of cases receiving additional local anesthesia preoperatively was also evaluated. Complications associated with sub-Tenon's parabulbar injection were monitored.

RESULTS

There were 101 instances of patients receiving additional anesthesia. Nineteen received additional preoperative sub-Tenon's anesthesia, 12 received intraoperative local anesthesia supplementation, and 70 received intravenous medication. Of these 70, 19 required what the authors defined as a significant amount of intravenous medication, three of whom also received intraoperative local anesthesia supplementation. Consequently, 28 of 200 patients (14%; 95% confidence interval: 9.5, 19.6) received supplementation (significant intravenous anesthesia, intraoperative local anesthesia, or both). The proportion of cases receiving supplementation was directly related to duration of surgery. Patients involved in longer cases (51.7% vs. 7.6%; P < 0.001) and those involved in more painful procedures (48.2% vs. 8.7%; P < 0.001) were more likely to receive supplementation. Adjusting for surgery duration, a greater proportion of patients undergoing painful procedures required supplementation (31.3% vs. 0.5% for surgery < 3 hours, P = 0.003; 72.7% vs. 38.9% for surgery > or = 3 hours, P = 0.13). No associated ocular or systemic complications were observed.

CONCLUSIONS

The results of this large study demonstrate that a single injection of sub-Tenon's anesthesia is relatively safe and effective for achieving local anesthesia during vitrectomies, with or without other intraocular procedures, lasting less than 3 hours. Other types of posterior segment surgery may require supplementation if they are more painful procedures, such as scleral buckle or cryotherapy, or last longer than 3 hours.

Immunological predictors of HIV-related survival

While the prognostic role of CD4 lymphocyte count is well established, little is known about how other immunological factors are associated with HIV-related survivorship. CD8 lymphocyte count is reported to inhibit growth of HIV in vitro and to deter the development of cytomeglovirus infections. Scarce information exists, however, on its association with HIV-related survivorship. The objective of the present study therefore was to assess whether survival estimation could be improved by including CD8 lymphocyte count as a prognostic factor. The study sample consisted of 904 adult HIV-infected patients who were treated between 1992 and 1997 at a large southwestern academic medical centre in the US. Survival analysis using proportional hazards modelling showed that baseline CD4 lymphocyte was highly and positively predictive of HIV-related survival. By contrast, baseline CD8 count was not predictive of survival in the study cohort. While the interaction between CD4 and CD8 was not statistically significant in the present study sample, decomposition of this effect indicates that these factors may operate synergistically to predict survival. In conclusion, these findings suggest that clinicians may improve their prognostic accuracy by relying on both CD4 and CD8 lymphocyte counts rather than relying exclusively on CD4 counts.

Salmeterol powder compared with albuterol aerosol as maintenance therapy for asthma in adolescent and adult patients

Two multicenter, randomized, double-masked, placebo-controlled studies involving 451 adolescent and adult patients with mild-to-moderate asthma compared the efficacy and safety of salmeterol powder 50 micrograms twice daily with albuterol 180 micrograms four times daily or placebo (with albuterol as needed) for 12 weeks. Patients had forced expiratory volume in 1 second (FEV1) of 50% to 80%. Throughout the 12-week treatment period, the mean change from baseline in percentage of predicted FEV1 was significantly greater with salmeterol than with placebo; mean area under the curve for FEV1 was significantly greater with salmeterol than with albuterol or placebo. Significant improvements in morning and evening peak expiratory flow, percentage of nights without awakening, and asthma symptoms were observed with salmeterol. Salmeterol was well tolerated, and no clinically significant changes in electrocardiographic activity were observed.

Abnormal DNA repair activities in lymphocytes of workers exposed to 1,3-butadiene

Exposure to high concentrations of butadiene has been shown to cause cancer among exposed workers. We have conducted a biomarker study to elucidate whether current butadiene exposure conditions are hazardous to workers. Twenty-four workers exposed consistently to butadiene were matched with 19 co-workers who had much less contact with butadiene and who served as our controls. In the standard cytogenetic assay, there was no difference in chromosome aberration frequencies between the exposed and control groups. In the challenge assay, the exposed group shows a consistent, but non-significant, increase in chromosome aberrations indicating some abnormality in DNA repair response. The observed dicentric frequency in the challenge assay (indicative of abnormal repair of damaged chromosomes) is significantly correlated with a butadiene metabolite, 1,2-dihydroxy-4-(N-acetylcysteinyl)butane, in urine (r = 0.52; p = 0.04). Furthermore, cigarette smokers had consistently abnormal repair response compared with non-smokers for both the control and exposed groups. A small subset of the studied workers were evaluated for toxicant-induced DNA repair deficiency using an independent cat-host cell reactivation (CAT-HCR) assay. When cigarette smokers and non-smokers were combined in our analysis, we observed that the exposed group (n = 9) had a significant reduction of DNA repair activities (p = 0.009) compared with the control group (n = 6). Cigarette smoking contributed significantly to the effect as exposed smokers (n = 4) had a significant reduction in DNA repair activities (p = 0.04) compared with exposed non-smokers. The results from the two independently conducted assays support each other and confirm the previously reported abnormal DNA repair response in another group of butadiene workers. In conclusion, our data indicates that exposure to environmental toxicants, such as butadiene, can cause DNA repair defects. Therefore, the current butadiene exposure conditions are still hazardous to workers. However, our data indicates that butadiene is not a potent genotoxic agent. Furthermore, the butadiene-induced effect is significantly enhanced by the cigarette smoking habit.

A hyaluronic acid membrane delivery system for cultured keratinocytes: clinical "take" rates in the porcine kerato-dermal model

The clinical take rates of cultured keratinocyte autografts are poor on a full-thickness wound unless a dermal bed is provided. Even under these circumstances two important problems are the time delay in growing autografts and the fragility of the grafts. A laser-perforated hyaluronic acid membrane delivery system allows grafting at early confluence without requiring dispase digestion to release grafts from their culture dishes. We designed this study to investigate the influence of this membrane on clinical take rates in an established porcine kerato-dermal grafting model. The study demonstrated a significant reduction in take as a result of halving the keratinocyte seeding density onto the membrane. The take rates, however, of grafts grown on the membrane at half or full conventional seeding density and transplanted to a dermal wound bed were comparable, if not better, than those of keratinocyte sheet grafts.

Exposure to organic solvents and hypertensive disorders of pregnancy

The present investigation compares the frequency of adverse pregnancy complications and outcomes in 90 women who worked with various organic solvents during pregnancy and in 180 unexposed matched (2:1) subjects. Solvent-exposed women were approximately four times more likely to develop preeclampsia, a disorder of pregnancy characterized by hypertension, edema, and proteinuria (unconditional adjusted RR = 3.9, 95% CI = 2.5, 5.4). That hypertension alone, without edema or proteinuria, was also more likely to be reported in solvent-exposed women (unconditional adjusted RR = 3.0, 95% CI = 0.9, 9.9) lent additional support to the association of solvent exposure and hypertensive disorders of pregnancy. Because preeclampsia is thought to be associated primarily with glomerular lesions, our findings, although in need of replication with a larger sample size, may be biologically plausible given the growing literature associating solvent exposure with renal disease. Solvent-exposed women were more likely to have cardiovascular complications and to deliver by cesarean section; however, given the specific type of complications and reason for cesarean, it is unlikely that these findings were directly related to solvent exposure. Other pregnancy complications such as threatened abortion and vaginal bleeding, and poor neonatal growth and maturity, were not more common in the exposed group.