HIV-associated immune dysfunction and delayed pubertal development in a cohort of young hemophiliacs. Hemophilia Growth and Development Study

As part of the Hemophilia Growth and Development Study (HGDS), we investigated the relationship between HIV-associated immune dysfunction and delayed pubertal development in a cohort of 333 boys and adolescents with moderate or severe hemophilia who were between the ages of 6 and 19 years at study entry in 1989. Sixty-two percent of the cohort was infected with HIV in the late 1970s and early 1980s through exposure to contaminated clotting factor concentrates. The cohort was observed during follow-up at 6-month intervals; measurements taken at each follow-up visit included Tanner stage and CD4+ cell count. This analysis of data from the first 4 years of follow-up revealed statistically significant delays in pubertal development associated with increasing levels of immune dysfunction. Our results emphasize the importance of following pubertal development in HIV-infected adolescent boys since delays in maturation may reflect underlying disease progression.

Primary prevention of childhood lead exposure: A randomized trial of dust control

BACKGROUND

Dust control is recommended as one of the primary strategies to prevent or control children's exposure to residential lead hazards, but the effect of dust control on children's blood lead levels is poorly understood.

OBJECTIVE

To determine the effectiveness of dust control in preventing children's exposure to lead, as measured by blood lead levels, during their peak age of susceptibility.

DESIGN

A randomized, controlled trial.

SETTING

Rochester, NY.

PARTICIPANTS

A total of 275 urban children were randomized at 6 months of age, of whom 246 (90%) were available for the 24-month-old follow-up visit.

INTERVENTIONS

Children and their families were randomly assigned to an intervention group (n = 140), which received cleaning equipment and up to eight visits by a dust control advisor, or a control group (n = 135).

OUTCOME MEASURES

Geometric mean blood lead levels and prevalence of elevated blood lead levels (ie, >10 microg/dL, 15 microg/dL, and 20 microg/dL).

RESULTS

At baseline, children's geometric mean blood lead levels were 2.9 microg/dL (95% confidence interval [CI] = 2.7, 3.1); there were no significant differences in characteristics or lead exposure by group assignment, with the exception of water lead levels. For children in the intervention group, the mean number of visits by a dust control advisor during the 18-month study period was 6.2; 51 (36%) had 4 to 7 visits, and 69 (49%) had 8 visits. At 24 months of age, the geometric mean blood lead was 7.3 microg/dL (95% CI = 6.6, 8.2) for the intervention group and 7.8 microg/dL (95% CI = 6.9, 8. 7) for the control group. The percentage of children with a 24-month blood lead >/=10 microg/dL, >/=15 microg/dL, and >/=20 microg/dL was 31% versus 36%, 12% versus 14%, and 5% versus 7% in the intervention and control groups, respectively.

CONCLUSIONS

We conclude that dust control, as performed by families and in the absence of lead hazard controls to reduce ongoing contamination from lead-based paint, is not effective in the primary prevention of childhood lead exposure.

X-chromosome inactivation patterns do not implicate asymmetric splitting of the inner cell mass in the aetiology of twin-twin transfusion syndrome

The aetiology of twin-twin transfusion syndrome (TTTS) is unclear. We investigated the hypothesis that monochorionic (MC) pregnancies with TTTS are associated with differences in the timing and symmetry of twinning compared to MC twin pregnancies without TTTS. DNA was extracted from the umbilical cord vessels of 26 female MC twins, 14 with and 12 without TTTS on serial antenatal ultrasound. X-inactivation patterns were determined by DNA digestion with Hhal and Hpall followed by polymerase chain reaction for a polymorphic trinucleotide repeat in the androgen receptor gene. Products were quantified by densitometry and results compared to those in peripheral blood samples of adult female controls. The median degree of non-random inactivation was similar in MC twins with TTTS, in MC twins without TTTS, and in adult controls. The percentage of individuals with skewed (> or =30/70%) inactivation patterns was no different in MC twins with TTTS compared to those without TTTS, and was similar to adult controls using either enzyme technique. In conclusion we found no difference in the degree or frequency of non-random X-inactivation patterns in TTTS. X-inactivation patterns do not appear to be a useful tool for studying the symmetry of inner cell mass splitting in monochorionic twins.

Volatilization of chemicals from drinking water to indoor air: the role of residential washing machines

Previous research has indicated that residential washing machines are potential sources of pollution due to the associated use of chemicals found in consumer products, for example, ethanol in laundry detergent and chlorine in bleach. Washing machines may also emit hazardous air pollutants found in contaminated drinking water. To better understand the extent and impact of chemical emissions from tap water, 26 experiments were completed using a residential washing machine and a cocktail of chemical tracers representing a wide range of physicochemical properties. Variable operating conditions for these experiments included water temperature, amount of clothes present in the machine, water volume, and level of washwater agitation. Chemical stripping efficiencies and mass transfer coefficients were determined during each cycle (fill, wash, and rinse) of a normal washing machine event. Headspace ventilation rates were determined using an isobutylene tracer gas. Mass transfer rates were significantly influenced by operating parameters as exhibited by a wide range of chemical stripping efficiencies. Stripping efficiencies ranged from 0.74 to 36% for acetone, 8.2 to 99% for toluene, 10 to 99% for ethylbenzene, and 6.9 to 100% for cyclohexane.

Detection of fetal messenger ribonucleic acid in maternal blood to determine fetal RhD status as a strategy for noninvasive prenatal diagnosis

OBJECTIVES

Our purpose was to test the hypothesis that reverse transcriptase-polymerase chain reaction for fetal messenger ribonucleic acid in maternal blood is more sensitive than polymerase chain reaction from genomic deoxyribonucleic acid in prenatal determination of fetal RhD blood type.

STUDY DESIGN

Fetal nucleated erythrocytes in peripheral blood from 35 RhD-negative women were enriched by triple-density gradient centrifugation, anti-CD71 magnetic sorted, and deoxyribonucleic acid and ribonucleic acid extracted. Sensitivities of reverse transcriptase-polymerase chain reaction and polymerase chain reaction were compared to predict definitive fetal RhD blood type determined in fetal tissues.

RESULTS

Reverse transcriptase-polymerase chain reaction was significantly more accurate (P = .03) than genomic-polymerase chain reaction in predicting fetal RhD blood type, both overall (28 of 35 vs 22 of 35) and when the fetus was RhD-positive (12 of 19 vs 6 of 19).

CONCLUSIONS

Reverse transcriptase-polymerase chain reaction is more sensitive than genomic-polymerase chain reaction in detection of fetal RhD sequences in maternal blood.

'Epiphyseal dysgenesis' in Laurence-Moon-Biedl-Bardet syndrome

Ten patients with Laurence-Moon-Biedl-Bardet syndrome were investigated. They all belonged to one large family within which several intermarriages had taken place. We found that, apart from the already described abnormalities, these patients suffered from dysgenesis of the following epiphyses: vertebrae, proximal femur, proximal tibia, capitellum, tarsal navicular, and the distal epiphysis of the first metatarsal. The degree of polydactyly, a prominent feature of this syndrome, varied from patient to patient, ranging from a wide fifth metatarsal or metacarpal to a complete sixth digit. As in other epiphyseal dysgenesis, a pseudoepiphysis of the distal first metacarpal was present. One patient (the eldest) was tetraparetic due to severe spinal stenosis.

Ketoacidosis occurring in newly diagnosed and established diabetic children

A 6-y retrospective case note review was performed to determine the causes of ketoacidosis. 135 patients and 463 diabetic years were involved. Fifty-two ketoacidosis episodes occurred: 19 episodes in new patients and 33 episodes in 19 patients with established diabetes. 27% of newly diagnosed patients presented in ketoacidosis. They were similar in terms of age, sex and proportion living in single parent families to those presenting without ketoacidosis. The 33 ketoacidosis episodes occurring in established patients included 12 episodes in 3 children who were transferred to our care because of uncontrolled diabetes. Insulin omission was the cause of ketoacidosis in 9/19 (47%) patients, and was suspected in a further 5/19 (26%). Family and school problems were common and 14/19 patients came from single parent families. Established patients aged > or = 11 y were predominantly female (10F, 2M), whereas patients aged < or = 10 y were predominantly male (6M, 1F). 7 patients with multiple ketoacidosis episodes were all > or = 11 y and 6 were female. Families with > or = 2 diabetic children appeared vulnerable, 4 cases coming from 3/7 such families.

Methodological approaches to assessing risk perceptions associated with food-related hazards

The psychometric approach developed by Slovic and his co-workers has been effectively used to assess risk perceptions associated with different food-related hazards. However, further examination (using questionnaire data and partial correlation techniques) has indicated that technological hazards are highly differentiated from lifestyle hazards, in terms of both hazard control and knowledge about the hazard. Optimistic bias was also seen to vary between hazards. Further research has focused on a particular hazard, genetic engineering. Risk perceptions associated with genetic engineering are underpinned by ethical concern and questions relating to perceived need for the technology, as well as perceptions of risk or harm. However, increasing the specificity of hazard stimuli was found to alter the factor structure of underlying risk perceptions. The utility of preference mapping procedures in determining individual differences in trust in risk regulators is also discussed.

Overview of the Second International Workshop to define swine cluster of differentiation (CD) antigens

The aim of the Second International Swine Cluster of Differentiation (CD) Workshop, supported by the Veterinary Immunology Committee (VIC) of the International Union of Immunological Societies (IUIS), was to standardize the assignment of monoclonal antibodies (mAb) reactive with porcine leukocyte differentiation antigens and to define new antibody clusters. At the summary meeting of the workshop in July, 1995, revisions in the existing nomenclature for Swine CD were approved, so that the rules are now in accord with those for human and ruminant CD. Swine CD numbers will now be given to clusters of mAb to swine orthologues of human CD molecules when homology is proven by (1) suitable tissue distribution and lymphoid cell subset expression, (2) appropriate molecular mass of the antigen recognized by the mAbs, and (3) reactivity of mAbs with the cloned swine gene products, or cross-reactivity of the mAb on the human gene products. In some cases, this reactivity would not be fully proven, mainly due to the lack of cloned gene products; for these CD antigens, the respective clusters will be assigned by the prefix 'w' which will lead to 'wCD' antigens. As a result of the Second International Swine CD Workshop the assignment of 16 mAb to existing CD groups (CD2a, CD4a, CD5a, wCD6, wCD8, CD14, CD18a, wCD21, wCD25) was confirmed, and 2 mAb to existing swine workshop clusters (SWC). More importantly, for the work on the porcine immune system, was the definition of 5 new swine CD antigens, namely CD3 (recognized by 6 new mAb and 3 epitopes), CD16 (1 new mAb), wCD29 (2 mAb), CD45RA (3 mAb) and CD45RC (1 new mAb). Finally, the demarcation of two new SWC molecules in swine, SWC8 (2 mAb) and SWC9 (2 mAb) was confirmed.

Cross-reactivity of human leucocyte differentiation antigen monoclonal antibodies on porcine cells

Thirty-six subpanels of monoclonal antibodies (mAbs) supplied to the Fifth International Workshop on Human Leucocyte Differentiation Antigens were assayed on porcine peripheral blood leucocytes for cross-reactivity. Sixty-two of the 752 mAbs-stained porcine cells. These mAbs identified 30 different CD groups and will be valuable reagents in the field of porcine immunology.

Purification and characterization of bovine dendritic cells from peripheral blood

Optimal activation of T lymphocytes depends on TCR interaction with peptide/MHC complexes in conjunction with costimulatory signals, which are delivered by specialized cells called antigen-presenting-cells (APC). The population of APC is heterogeneous and includes dendritic cells, B cells and macrophages. The family of dendritic cells (DC) is widely distributed in tissues and plays a major role in the induction of primary T-dependent immune responses. The aim of this paper was to isolate and characterize dendritic cells from cattle. Two methods are described that have been used to isolate dendritic cells from bovine peripheral blood. One method involves sequential depletion of other cells, adherence and isolation of low buoyant density cells on Metrizamide column. The second involves enrichment of cells displaying receptors for plasma fibronectin, followed by adherence and separation on Metrizamide. Both preparations were characterized morphologically by flow cytometry and functionally. Both procedures produced enriched populations that did not express molecules typical of T cells (CD3, CD4, CD8, WC1), B cells (sIg, CD21) and monocytes (CD14, Fc gamma 2R). Procedure 2 yielded cells with a typical veiled DC morphology that were highly effective at stimulating allogeneic T cells. Procedure 1 yielded cells that did not have the veiled morphology and were less effective in the MLR which may represent a more immature stage.

The elaboration likelihood model and communication about food risks

Factors such as hazard type and source credibility have been identified as important in the establishment of effective strategies for risk communication. The elaboration likelihood model was adapted to investigate the potential impact of hazard type, information source, and persuasive content of information on individual engagement in elaborative, or thoughtful, cognitions about risk messages. One hundred sixty respondents were allocated to one of eight experimental groups, and the effects of source credibility, persuasive content of information and hazard type were systematically varied. The impact of the different factors on beliefs about the information and elaborative processing examined. Low credibility was particularly important in reducing risk perceptions, although persuasive content and hazard type were also influential in determining whether elaborative processing occurred.

Renal structural-functional relationships in early diabetes mellitus

To define the earliest renal morphological changes in patients with type I diabetes, we studied renal function and morphometric analysis of renal biopsies in 59 patients with diabetes for 5-12 years and normal blood pressure, normal creatinine clearance (CCr), and negative dipstick urinary protein. Arteriolar hyalinization and intimal fibrous thickening were noted in 43%. Glomerular basement membrane thickness and fractional mesangial volume were increased in 51% and 56%, respectively. The pre-pubertal and post-pubertal years of diabetes were associated with similar degrees of renal structural changes, but during the pre-pubertal years normal urinary albumin excretion (UAE) was seen. Principal factor analysis of morphometric structural parameters yielded four clusters of variables: "glomerular size" correlated with patient age, CCr, and UAE; "peripheral capillary decrease" correlated with glycosylated hemoglobin, diastolic blood pressure, glomerular filtration rate, and UAE; "mesangial increase" correlated with UAE; and "interstitial scarring" correlated with diastolic blood pressure. This study provides unique documentation of renal structural abnormalities which precede clinically evident renal functional abnormalities and documents that these early structural abnormalities are present in the pre-pubertal years of diabetes as well as postpuberty, and are associated with each other in constellations that correspond to postulated mechanisms in diabetic nephropathy.

Educational programme for staff implementing a new renal replacement therapy

Haemofiltration is increasingly being considered as an alternative choice of treatment to conventional Haemodialysis for patients with Acute and Chronic Renal Failure. A leading company in renal replacement therapy offered the renal unit the challenge of being one of the first units in the United Kingdom to trial a new on-line Haemofiltration machine.

Economic and ethical considerations in managed care

The growth of managed care has had a significant impact on the way hospitals provide medical services, the relationships between hospitals and physicians, and the relationships between providers and patients. This impact arises primarily from the economic constraints that managed care places on the provider. As hospital employees or contractors, and as consumers of health care services, clinical engineering personnel need to understand the effects of managed care on the hospital and the physician. Beyond general information, this knowledge can play a useful role in understanding the impact of managed care on the acquisition and use of medical technology, and the increasing role that clinical engineering can play in guiding investment in, use and maintenance of hospital medical equipment. Ironically, this potential for increased value occurs at a time when clinical engineering services and departments themselves are under increased scrutiny for their more measurable costs and value.

Enhanced therapeutic effect of amsalog (CI-921) in combination with cisplatin in vitro and in vivo

CI-921, the 5-methyl-4-carboxamide analog of amsacrine, in combination with cisplatin produced a 6-fold better cell kill in vitro than expected based on additive effects. The combination of CI-921 and cisplatin was subsequently evaluated in three in vivo model systems: intraperitoneally (TP) and intravenously (IV) implanted P388 leukemia, and advanced stage subcutaneously (SC) implanted LC-12 squamous cell carcinoma. All drug treatments were administered IP on an intermittent treatment schedule which was optimal for both agents. Combination therapy was superior to therapy with the best single agent alone, CI-921, in all three model systems. Against IP implanted P388 leukemia, combination therapy produced greater than 8 logs of net tumor cell kill with 60-day survivors (cures). This level of activity was 50-fold greater (1.7 log) than that obtained with CI-921 alone. An IV implant of P388 leukemia was used in a confirmatory study to provide a more rigorous evaluation against disseminated disease. Combination therapy against IV implanted P388 leukemia produced greater than 7.7 logs of net tumor cell kill, which was 630-fold greater (2.8 logs) than that obtained with CI-921 therapy alone. Against advanced stage LC-12 (200-1000 mg tumors at initial treatment), combination therapy improved tumor cell kill by 0.6 log (4-fold) over that obtained with CI-921 therapy alone and also produced greater numbers of 120-day survivors than did single agent therapy with CI-921. The combination of carboplatin and CI-921 was also evaluated against IV implanted P388 leukemia to determine if the enhanced therapeutic effect of CI-921 and cisplatin could be extended to include CI-921 and carboplatin. Combination therapy with CI-921 and carboplatin increased net log tumor cell kill by 0.8 and 1.5 log in two separate tests (6- and 32-fold, respectively) over that obtained with CI-921 therapy alone. The data indicate that combination therapy with CI-921 and platinum containing anticancer agents may have clinical application.