Screening for carbon monoxide in children

OBJECTIVE

Carbon monoxide (CO), a colorless, odorless gas, accounts for the majority of fatal poisonings in the United States. To date, few screening studies that evaluate pediatric exposure are available. The objectives of this study were to determine the value of a CO breath analyzer for detecting pediatric CO exposure and to identify potential CO sources.

DESIGN

Prospective screening study.

SETTING

Emergency department of an urban children's hospital.

PATIENTS

A convenience random sample of 470 noncritically ill children, aged five to 20 years, who presented to a pediatric emergency department and could blow into a CO breath analyzer.

INTERVENTION

After informed consent and demographic and clinical variables were ascertained, eligible patients blew into a CO breath analyzer. Those with breath CO levels > or = 9 ppm underwent confirmatory cooximetric analysis of capillary blood. Sources of CO exposure were determined by history and a home-site evaluation by the local gas company. Patients with carboxyhemoglobin (COHb) levels of more than 5% were given normobaric 100% oxygen until their COHb levels were less than 5%.

RESULTS

1.9% (9/470) of patients had elevated breath CO levels and COHb levels by cooximetry. Putative sources of CO exposure were active cigarette smoking for five patients and a faulty furnace in the home for one patient. On the basis of the history, we believe environmental tobacco smoke or automobile exhaust or both contributed to the elevated COHb levels in the other three patients. There was a good correlation between COHb by cooximetry and breath analysis (concordance correlation = 0.739) CONCLUSION: Breath analysis for CO is a convenient tool to estimate exposure and identify older children at risk.

Outpatient continuous intravenous interleukin-2 or subcutaneous, polyethylene glycol-modified interleukin-2 in human immunodeficiency virus-infected patients: a randomized, controlled, multicenter study. Australian IL-2 Study Group

The safety and activity of outpatient-based continuous intravenous interleukin-2 (CIV IL-2) or a slow-release, polyethylene glycol (PEG)-modified IL-2 were studied in human immunodeficiency virus (HIV)-infected persons with CD4 cell counts between 200 and 500/mm3. One hundred fifteen patients were randomized to antiretroviral therapy plus cyclical CIV IL-2 (n = 27), subcutaneous PEG IL-2 (n = 58), or no IL-2 (n = 30). Toxicity withdrawal rates were low (4% for CIV IL-2 and 7% for PEG IL-2). There were median CD4 cell count increases of 359 and 44 cells/mm3 and a decline of 46 cells/mm3 in the 3 groups, respectively, over 1 year (P < .0001 for each intergroup comparison). CD4 cell count increases were greatest in those with lower HIV RNA load. Delayed-type hypersensitivity scores increased and HLA-DR expression on CD8 cells decreased significantly with IL-2 therapy. HIV RNA levels were unaffected. IL-2 therapy may expand the existing immune repertoire but not immediately reconstitute lost immune function.

Chronic multisymptom illness affecting Air Force veterans of the Gulf War

CONTEXT

Gulf War (GW) veterans report nonspecific symptoms significantly more often than their nondeployed peers. However, no specific disorder has been identified, and the etiologic basis and clinical significance of their symptoms remain unclear.

OBJECTIVES

To organize symptoms reported by US Air Force GW veterans into a case definition, to characterize clinical features, and to evaluate risk factors.

DESIGN

Cross-sectional population survey of individual characteristics and symptoms and clinical evaluation (including a structured interview, the Medical Outcomes Study Short Form 36, psychiatric screening, physical examination, clinical laboratory tests, and serologic assays for antibodies against viruses, rickettsia, parasites, and bacteria) conducted in 1995.

PARTICIPANTS AND SETTING

The cross-sectional questionnaire survey included 3723 currently active volunteers, irrespective of health status or GW participation, from 4 air force populations. The cross-sectional clinical evaluation included 158 GW veterans from one unit, irrespective of health status.

MAIN OUTCOME MEASURES

Symptom-based case definition; case prevalence rate for GW veterans and nondeployed personnel; clinical and laboratory findings among veterans who met the case definition.

RESULTS

We defined a case as having 1 or more chronic symptoms from at least 2 of 3 categories (fatigue, mood-cognition, and musculoskeletal). The prevalence of mild-to-moderate and severe cases was 39% and 6%, respectively, among 1155 GW veterans compared with 14% and 0.7% among 2520 nondeployed personnel. Illness was not associated with time or place of deployment or with duties during the war. Fifty-nine clinically evaluated GW veterans (37%) were noncases, 86 (54%) mild-to-moderate cases, and 13 (8%) severe cases. Although no physical examination, laboratory, or serologic findings identified cases, veterans who met the case definition had significantly diminished functioning and well-being.

CONCLUSIONS

Among currently active members of 4 Air Force populations, a chronic multisymptom condition was significantly associated with deployment to the GW. The condition was not associated with specific GW exposures and also affected nondeployed personnel.

Genomewide search for dehydrated hereditary stomatocytosis (hereditary xerocytosis): mapping of locus to chromosome 16 (16q23-qter)

Dehydrated hereditary stomatocytosis, also known as "hereditary xerocytosis," is caused by a red blood cell-membrane defect characterized by stomatocytic morphology, increased mean corpuscular hemoglobin concentration, decreased osmotic fragility, increased permeability to the univalent cations Na+ and K+, and an increased proportion of phosphatidylcholine in the membrane. The clinical presentation is heterogeneous, ranging from mild to moderate hemolytic anemia associated with scleral icterus, splenomegaly, and choletithiasis. Iron overload may develop later in life. The disease is transmitted as an autosomal dominant trait. We recruited a large three-generation Irish family affected with DHS and comprising 23 members, of whom 14 were affected and 9 were healthy. Two additional, small families also were included in the study. The DNA samples from the family members were used in a genomewide search to identify, by linkage analysis, the DHS locus. After the exclusion of a portion of the human genome, we obtained conclusive evidence for linkage of DHS to microsatellite markers on the long arm of chromosome 16 (16q23-q24). A maximum two-point LOD score of 6.62 at recombination fraction .00 was obtained with marker D16S520. There are no recombination events defining the telomeric limit of the region, which therefore is quite large. No candidate genes map to this area.

Effects of hydrotherapy on pressure ulcer healing

Pressure ulcers are a prevalent and potentially serious medical problem encountered in both the medical and rehabilitation settings. Because the progress of rehabilitation is often interrupted by the presence of pressure ulcers, the efficient care of these wounds is of great interest to the rehabilitation team. Patients in two acute care facilities with Stage III or IV pressure ulcers were identified and consented to participate in the study contained herein. All wounds were mechanically debrided of necrotic tissue, and then the patients were randomly assigned to the conservative treatment group (A; n = 18) or the conservative treatment plus whirlpool group (B; n = 24). Conservative treatment included measures to maximize pressure relief and wound care with wet-to-wet dressings using normal saline. The dressings were changed twice daily and when they became soiled. Whirlpool was administered for 20 min per day in Group B patients. Only those patients whose ulcers were followed-up for 2 or more wk were included in the study. Ulcers were then measured by a physician who was blinded as to the treatment groups. Ulcer dimension changes over time were compared between groups. The results indicate that the conservative treatment plus whirlpool group improved at a significantly faster rate than did the conservative treatment only group (P < 0.05).

The new variant form of Creutzfeldt-Jakob disease

A new phenotype of Creutzfeldt-Jakob disease termed new variant Creutzfeldt-Jakob disease (nvCJD) was first described in March 1996. This differs from other forms of CJD in terms of its epidemiology, clinical features and neuropathology. To date 24 cases of this new form of CJD have been described, 23 within the UK. This article describes nvCJD discussing clinical and epidemiological features and discusses possible links with the bovine spongiform encephalopathy epidemic in cattle in the UK.

Influence of polymorphism Q3405E and mutation A3371V in the apolipoprotein B gene on LDL receptor binding

Familial defective apolipoprotein B (FDB) is due to mutations in the apolipoprotein B (apo B) gene at codon 3500 or 3531 that affect low density lipoprotein (LDL) receptor binding. From sequence analysis the putative receptor binding site was believed originally to be upstream from this at residues 3147-3157 and 3357-3367. Using denaturing gradient gel electrophoresis, mutations were sought in codons 3350-3466. This includes the important positively charged residues 3357-3367. DNA from 928 hyperlipidaemic individuals was studied and two hitherto unknown DNA changes were discovered, one of which resulted in an altered amino acid in the apo B. A known polymorphism Q3405E was also detected at a carrier frequency of 1.4%. Using growth of U937 cells as a measure of binding affinity of LDL to its receptor the newly discovered mutant A3371V permitted the same growth as LDL from normolipidaemic individuals of the U937 cells, however, the LDL from Q3405E individuals permitted only 77% of the normal growth (P=0.009).

Cloning of a complementary DNA encoding an Ambystoma mexicanum metallothionein, AmMT, and expression of the gene during early development

We have used a polymerase chain reaction strategy to isolate a metallothionein (MT) cDNA from the amphibian Ambystoma mexicanum (axolotl). This cDNA is 875-bp long and encodes a 60 amino acid protein, AmMT, typical for family 1 MTs. It contains 20 cysteine (Cys) residues that can be aligned with those of other vertebrate MTs. The overall structure of the protein is unique among vertebrates in having only two amino acid residues before the first Cys at the amino-terminal end. Northern analyses showed that AmMT is expressed throughout embryogenesis, giving rise to three mRNA species of 650, 750, and 1,600 nucleotides (nt). The 750 and 1,600 nt transcripts appear to result from differential use of polyadenylation signals, whereas the 650 nt RNA could arise from deadenylation of the 750-nt transcript. Both the 750- and 1,600-nt RNAs were presented in embryos before the mid-blastula transition (MBT). After the MBT, the 750-nt RNA was replaced by the 650-nt RNA which was gradually degraded to undetectable levels in post-neurulation embryos. Levels of the 1,600-nt transcript increased at gastrulation and reach a maximum in Stage 30 embryos. In adult animals, levels of the 750-nt RNA were high in liver and testes, and very low in lung, gut, skin, and oviducts, whereas levels of the 1,600-nt transcript were similar and moderately elevated in all tissues examined. In contrast, in Xenopus laevis, Northern analysis did not detect XIMT-A mRNA in embryos before late neurulation (Stage 24). XIMT-A mRNA levels then increased sharply in Stage 36 hatched embryos at levels similar to those found in adult livers. These results show that AmMT presents a unique expression pattern among metazoans being transcribed as two transcripts differing in the length of their 3' untranslated regions, the levels of which vary during embryogenesis and in adult tissues.

Expect the worse or hope for the best? Prenatal diagnosis of geleophysic dysplasia

Geleophysic dysplasia is a rare, autosomal recessive disorder which causes disproportionate short stature associated with severe physical handicaps, but is compatible with survival into adulthood. We present a case, a first-born child, where genetic counselling difficulties arose following ultrasound recognition of short-limbed dwarfism in association with polyhydramnios and an initial incorrect prenatal diagnosis of lethal chondrodysplasia. After birth of the surviving affected infant, the parents had great difficulty accepting that there had been a prenatal misdiagnosis and they were greatly disappointed by our inability to predict the postnatal survival of an infant to whom no hope of life had previously been given. The correct diagnosis was not made until the proband was nearly 1 year old, and the true prognosis then became clearer. This experience underlines the relative ease of prenatal recognition of skeletal growth abnormalities compared with the considerable difficulties experienced in reaching a precise diagnosis. Thus, following prenatal diagnosis of unspecified chondrodysplasia when parents seek definite information about the prognosis, the temptation to be either overpessimistic or overoptimistic should be avoided.

Investigation of interferometric noise in fiber-optic gas sensors with use of wavelength modulation spectroscopy

We report on interferometric noise limitation of fiber-optic gas sensors with highly coherent lasers and wavelength modulation spectroscopy. Interference between signal wave and reflected waves causes signal fluctuation in the output, which limits the performance of the sensing system. Sensor resolution limited by interferometric noise is calculated for a fiber-optic gas sensor with the Q(6) absorption line of methane gas at approximately 1650 nm. The results are useful for system designers of this particular type of gas sensor.

Limitation of absorption-based fiber optic gas sensors by coherent reflections

We report the noise limitation of fiber optic gas sensors with highly coherent laser sources. Interference between signal and reflected waves causes signal fluctuation in the output; this limits the performance of the sensing system. Sensor resolutions limited by coherent reflections are calculated and compared with experimental results.

Changes in empowerment: effects of participation in a lay health promotion program

The Camp Health Aide Program is a lay health promotion program for migrant and seasonal farmworkers. The program increases access to health care while facilitating leadership development and empowerment of individual farmworkers through training and experience as lay health promoters (camp health aides [CHAs]). This article describes a study which documents impacts on the CHAs of working as lay health promoters in terms of changes in personal empowerment. The authors developed a working definition of personal empowerment and interviewed 27 CHAs at three program sites (Arizona, New Jersey, and Florida) at three different times. CHAs are grouped in five descriptive categories reflecting varying degrees of change in empowerment over this period. Of the total group of 27 CHAs, 24 exhibited some increase in personal empowerment during the study period. These changes are described in detail, and implications are discussed.

Specialisation in nursing: implications in Australia

Specialisation in professional nursing practice requires the collaborative development of appropriate processes, systems and pathways. Orderly development ensures that the unique knowledge, skills and attributes of specialist nurses are revealed, thereby empowering nurses and adding depth and breadth to specialist nursing knowledge and clinical practice.

HIV antibodies: further questions and a plea for clarification

The existence of specific antibody/protein reactions is the crucial assumption underlying proof of HIV isolation, proof of HIV infection and the causative role of HIV in AIDS. However, since 1. antibodies which react with the 'HIV' proteins arise following allogenic stimuli in non-HIV-infected animals and humans, as well as in mice and humans with autoimmune disorders; antibodies to antigens from both mycobacteria and yeasts cross-react with HIV env and gag proteins; 2. individuals belonging to the AIDS risk groups are subjected to allogenic stimuli and have high levels of autoimmune antibodies, while the vast majority of patients in the AIDS risk groups are infected with either or both mycobacteria or yeasts; the evidence for the existence of HIV and its putative role in AIDS must be reappraised.