Ingestion of false hellebore plants can cross-react with a digoxin clinical chemistry assay.

INTRODUCTION: We report a case of digoxin-like toxicity because of ingestion of foraged plants. This patient presented with nausea, vomiting, bradycardia, and hypotension after ingesting Veratrum viride (false hellebore). The patient's serum specimen demonstrated a positive digoxin level (0.38 ng/mL) measured by a clinical tubidimetric immunoassay. We hypothesize that steroidal alkaloid compounds contained in V. viride cross-react with the Multigent Digoxin immunoassay reagent antibodies. RESULTS: Plant extracts from V. viride demonstrated cross-reactivity to Multigent reagent antibodies but did not bind therapeutic DigiFab antibodies. Gas chromatography/mass spectrometry analyses identified several steroidal alkaloid compounds present in the V. viride extracts: jervine, ribigirvine, solanidine, and veratraman. CONCLUSIONS: This study indicates that compounds extracted from V. viride can cross-react with a clinical Digoxin immunoassay. Yet these extracts did not bind DigiFab antibody fragments used for therapeutic intervention. Providers should not unnecessarily administer DigiFab fragments as an antidote in symptomatic V. viride toxic patients.

The evaluation and management of acute poisoning emergencies.

Emergency physicians will regularly be called upon to care for poisoned patients. The purpose of this article is to review the general approach to the poisoned patient. Specific signs and symptoms will be identified that may clue the clinician into a specific toxin class as a diagnosis. Necessary testing in poisonings will be highlighted. This article will also introduce the basics of gastrointestinal decontamination and antidotes against select poisons.

Evolutionary breakpoints on human chromosome 21.

Segments of the long arm of human chromosome 21 are conserved, centromere to telomere, in mouse chromosomes 16, 17, and 10. There have been 28 genes identified in human chromosome 21 between TMPRSS2, whose orthologue is the most distal gene mapped to mouse chromosome 16, and PDXK, whose orthologue is the most proximal gene mapped to mouse chromosome 10. Only 6 of these 28 genes have been mapped in mouse, and all are located on chromosome 17. To better define the chromosome 17 segment and the 16 to 17 transition, we used a combination of mouse radiation hybrid panel mapping and physical mapping by mouse: human genomic sequence comparison. We have determined the mouse chromosomal location of an additional 12 genes, predicted the location of 7 more,and defined the endpoints of the mouse chromosome 17 region. The mouse chromosome 16/chromosome 17 evolutionary breakpoint is between human genes ZNF295 and UMODL1, showing there are seven genes in the chromosome 16 segment distal to Tmprss2. The chromosome 17/chromosome 10 breakpoint seems to have involved a duplication of the gene PDXK, which on chromosome 21 lies immediately distal to the KIAA0179 gene. These data suggest that there may be as few as 21 functional genes in the mouse chromosome 17 segment. This information is important for defining existing and constructing more complete mouse models of Down syndrome.

Ts65Dn -- localization of the translocation breakpoint and trisomic gene content in a mouse model for Down syndrome.

Fluorescent in situ hybridization (FISH) -- using mouse chromosome paints, probes for the mouse major centromeric satellite DNA, and probes for genes on chromosomes (Chr) 16 and 17 -- was employed to locate the breakpoint in a translocation used to produce a mouse model for Down syndrome. The Ts65Dn trisomy is derived from the reciprocal translocation T(16;17)65Dn. The Ts65Dn mouse carries a marker chromosome containing the distal segment of Chr 16, a region that shows linkage conservation with human Chr 21, and the proximal end of Chr 17. This chromosome confers trisomy for most of the genes in the Chr 16 segment and Ts65Dn mice show many of the phenotypic features characteristic of Down syndrome. We used FISH on metaphase chromosomes from translocation T65Dn/+ heterozygotes and Ts65Dn mice to show that the Chr 17 breakpoint is distal to the heterochromatin of Chr 17, that the Ts65Dn marker chromosome contains a small portion of Chr 17 euchromatin, that the Chr 16 breakpoint lies between the Ncam2 and Gabpa/App genes, and that the Ts65Dn chromosome contains >80% of the human Chr 21 homologs. The significance of this finding is discussed in terms of the utility of this mouse model.

The impact of ethanol and Marinol/marijuana usage on HIV+/AIDS patients undergoing azidothymidine, azidothymidine/dideoxycytidine, or dideoxyinosine therapy.

Therapeutic observations suggest that azidothymidine (AZT)-resistant HIV+/AIDS patients are frequently offered AZT/dideoxycytidine (DDC) or dideoxyinosine (DDI) therapy. The latter therapies have been associated with the development of acute pancreatitis. During the initial portion of this study, when patients reported limiting ethanol consumption, an increase in CD4+, a decrease in amylase, and a decrease in lipase was observed in patients on DDI monotherapy. Marinol/marijuana usage was associated with depressed CD4+ counts and elevated amylase levels within the DDI subgroup. The purpose of this study was to follow these patients over 1 year and compare clinical indicators of pancreatitis and HIV progression. After 1 year, the remaining 56 patients were reexamined in the follow-up portion for clinical indicators of HIV disease progression and pancreatoxic/hepatotoxic effects. Those in the AZT group, who remained on this therapy throughout the year, had significantly increased amylase values from 55.3 to 69.3 IU/liter (p < 0.05). In the AZT/DDC group, those who remained on combination therapy throughout the year, 4 of the 5 clinical indicators of disease progression changed. Amylase, ALT, and AST all increased significantly from 55.2 to 77.8 IU/liter (p < 0.01), from 38.0 to 92.3 IU/liter (p < 0.05), and from 55.2 to 97.0 IU/liter (p < 0.05), respectively. Lipase levels decreased significantly (106.0 to 74.6 IU/liter, p < 0.05). The most remarkable changes occurred in the AZT/DDC group (who reduced ethanol consumption), wherein clinical indicators of pancreatitis and liver dysfunction declined, including amylase (65.0 to 20.0 IU/liter, p < 0.05), ALT (350.0 to 100.0 IU/liter, p < 0.01), and AST (240.0 to 95.0 IU/liter, p < 0.01). No significant changes were noted in the DDI or AZT groups. Marinol/marijuana use was associated with declining health status in both the AZT and AZT/DDC groups. In contrast, all clinical indicators of pancreatitis improved in the DDI patients who utilized Marinol/marijuana, including amylase (-34%), lipase (-30.8%), ALT (-21.4%), and AST (-20.1%). This paired follow-up study suggests that HIV+/AIDS patients on antiretroviral therapies should restrict their ethanol consumption. In HIV+/AIDS patients with the lowest CD4+ counts (those on DDI monotherapy), utilization of Marinol/marijuana does not seem to have a deleterious impact.

Managing the child infected with HIV.

Care of the HIV-infected/exposed infant and child is both routine and challenging. Routine well child care and immunizations are an important part of maintaining and monitoring health status. Challenges arise in the management of acute illnesses and the numerous crises that are experienced by the family caring for that child. Therapy guidelines now provide a logical way in which to initiate antiretroviral treatment and PCP prophylaxis. In HIV-infected children with early disease, common pathogens initially predominate, and only in advanced immune suppression does care become complicated enough to require expert consultation. With increasing numbers of HIV-infected women, perinatally acquired infections in infants will become more common. Early testing and identification will increasingly be important as a way to impact on the significant morbidity and mortality seen in infants less than 6 months old. A caring, compassionate, and comprehensive approach to the care of HIV-infected infants and children results in increased survival and lengthening of disease-free time. Providing this vitally needed care is both satisfying and stimulating.

HIV-1 DNA in fibroblast cultures infected with urine from HIV-seropositive cytomegalovirus (CMV) excretors.

Interactions between HIV-1 and CMV may be important in the pathogenesis of AIDS. We have studied whether active CMV infection alters the cell tropism of HIV-1 in dually-infected individuals. Urines from HIV-seropositive individuals excreting CMV were compared to urines from CMV non-excretors. Sixty-six urines from HIV-seropositive individuals were tested. Infectious HIV-1 was not detected in any of the concentrated urines tested. The urines were filtered, concentrated, DNase-treated and cultured on HIV-1 non-permissive human forestin fibroblasts. HIV-1 DNA was detected by PCR with pol gene primers in 5 of 39 MRHF cell cultures inoculated with CMV culture positive urine (p = 0.037). HIV-1 DNA was not detected by PCR in uninfected fibroblasts, in fibroblasts inoculated with CMV uninfected urine from 27 HIV-seropositive patients or in fibroblasts cultured with 9 CMV culture positive urines from 16 HIV-seronegative renal transplant recipients. Supernatant fluid from an HIV-1 PCR-positive culture was passaged onto another fibroblast monolayer, and these cells were negative for HIV-1 DNA. Direct inoculation of fibroblasts with HIV-1 did not yield evidence of infection by PCR. CMV infection may facilitate HIV-1 DNA entry into ordinarily non-permissive cells.

Applying cooperative learning in health education practice.

Cooperative learning encompasses both a teaching philosophy and instructional methods that encourage students to work together to maximize learning. This article examines the rationale for incorporating cooperative learning in health education, reviews cooperative learning basics, and provides an example of cooperative learning technique in health education.

Interactions between HIV-1 and cytomegalovirus in human osteosarcoma cells carrying both viruses.

Cytomegalovirus (CMV) and the human immunodeficiency virus type 1 (HIV-1) may interact in the pathogenesis of AIDS. We compared CMV replication in human osteosarcoma (HOS) cells to that in HOS cells genetically engineered to contain an envelope-deficient HIV-1 proviral construct (designated HOS-HXG). Following acute CMV infection of each cell line, HOS-HXG cells contained higher numbers of intranuclear CMV nucleocapsids than did HOS cells. Infectious CMV could be persistently detected in culture supernatant fluids of the CMV-infected HOS-HXG cells, whereas CMV was lost over several weeks from HOS cells infected with CMV in parallel. HIV-1 CMV pseudotypes were not detected in supernatant fluids from CMV-infected HOS-HXG cells. On day 119 after CMV infection, these cultures were superinfected with HIV-1. These dually infected HOS-HXG cells produced infectious HIV-1 and exhibited markedly enhanced CMV replication compared to parental CMV-infected HOS-HXG cells. Two different HIV-1 tat gene function antagonists, Ro24-7429 and chemically modified antibodies to the Tat protein, did not inhibit the replication of CMV in either acute or persistent infections of HOS-HXG cells at concentrations that inhibited HIV-1 replication.

Use of evolutionary limitations of HIV-1 multidrug resistance to optimize therapy.

Wild-type reverse transcriptase has evolved for the survival of human immunodeficiency virus type 1 (HIV-1) by natural selection. In contrast, therapy relying on inhibitors of reverse transcriptase by nucleosides like zidovudine (AZT) or dideoxyinosine (ddI), and by non-nucleosides like pyridinones or nevirapine, may exert different selection pressures on this enzyme. Therefore the acquisition of resistance to reverse transcriptase inhibitors by selection of mutations in the pol gene may require compromises in enzyme function that affect viral replication. As single mutations are unlikely to confer broad resistance when combinations of reverse transcriptase inhibitors are used, multiple mutations may occur that result in further compromises. Certain drug combinations may prevent the co-existence of adequate reverse transcription function and multi-drug resistance (MDR). Unlike bacterial or eukaryotic drug resistance, retroviral drug resistance is conferred only by mutations in its own genome and is limited by genome size. Combining drugs directed against the same essential viral protein may thus prevent HIV-1 MDR, whereas the conventional approach of targeting different HIV-1 proteins for combination therapy may not, because genomes with resistance mutations in different HIV-1 genes might recombine to develop MDR. Here we show that several mutations in the HIV-1 reverse transcriptase gene that confer resistance to inhibitors of this enzyme can attenuate viral replication. We tested whether combinations of mutations giving rise to single-agent resistance might further compromise or even abolish viral replication, and if multidrug-resistant viruses could be constructed. Certain combinations of mutations conferring resistance to AZT, ddI and pyridinone are incompatible with viral replication. These results indicate that evolutionary limitations exist to restrict development of MDR. Furthermore, a therapeutic strategy exploiting these limitations by using selected multidrug regimens directed against the same target may prevent development of MDR. This approach, which we call convergent combination therapy, eliminated HIV-1 replication and virus breakthrough in vitro, and may be applicable to other viral targets. Moreover, elimination of reverse transcription by convergent combination therapy may also limit MDR.

Comparison of spot-blot and microtitre plate methods for the detection of HIV-1 PCR products.

We have compared spot-blot methodology with a recently developed rapid microtitre plate assay for the specific detection of HIV-1 PCR products. We have studied blood specimens isolated from HIV-1 infected individuals (48 asymptomatic and 56 symptomatic patients). Mononuclear cells were isolated, lysed and processed for PCR. Both PCR product detection methods were carried out in parallel on all amplified samples. HIV-1 sequences were detected by spot-blot or microtitre plate hybridization in samples taken from 42/48 asymptomatic and 53/56 symptomatic subjects. Concordant results between the two detection methods were observed for 90 samples, with 81 positive and nine negative assays. On repeat evaluation of the 14 discordant samples, nine showed concordant positive results, near the limit of detection of the assay. Serial dilutions of ACH-2 cells were amplified, and the PCR products were detected using the microtitre plate assay, yielding semi-quantitative results. The sensitivity of this simple, rapid assay compares with that of more laborious DNA detection systems. This may become a useful tool in HIV-1 research and in the clinical care of seropositive individuals.

Eosinophils as host cells for HIV-1.

Transient expression of HIV-1 p24 antigen was observed in eosinophils acutely infected with the HTLV-IIIB strain of HIV-1. PCR analysis of eosinophils isolated from 18 seropositive individuals showed HIV-1 sequences to be present in 2 subjects. These data suggest that eosinophils may act as host cells for HIV-1.

HIV risk continuum.

PIP: Education is essential in the prevention of HIV infection transmission and in subduing misconceptions and prejudice toward AIDS. Children should have access to reliable information regarding this disease. The HIV Risk Continuum is proposed as an effective method for teaching children about HIV infection and appraising students AIDS/HIV knowledge. It is designed to assist children in identifying credible information concerning HIV risk, in differentiating accurate information from rumors, in decreasing irrational fears, and improving communication abilities. Materials required for this proposal include 5" x 7" cards displaying age-appropriate terms, 8" x 24" posterboard labeled :HIV RISK CONTINUUM", 2 individual 8 1/2" x 11" posterboard labeled "HIGH RISK" and "NO RISK", making tape, and an open wall space. Students are taught terms which may be either high or low risk for HIV transmission. By using method, it is hoped that children can identify and avoid behavior or activities which are at high risk for AIDS.^ieng

Detection of HIV-1 DNA in crude cell lysates of peripheral blood mononuclear cells by the polymerase chain reaction and nonradioactive oligonucleotide probes.

The aim of this study was to detect HIV-1 proviral DNA in lysates of peripheral blood mononuclear cells (PBMCs) by the polymerase chain reaction (PCR) and hybridization with a nonradioactive probe. PBMCs were lysed in 1% Triton X-100. PCR was then carried out using primers complementary to a conserved region of the HIV-1 pol gene. Bracket and nested amplification protocols were used. Products were identified by dot-blot hybridization or agarose gel electrophoresis and Southern hybridization, using an alkaline phosphatase-linked oligonucleotide probe specific for amplified sequences. Colorimetric and chemiluminescent substrates were used. HIV-1 DNA was detected in PBMCs of 57/59 HIV-1-seropositive individuals, 8 of which were positive only following the use of nested primers. Of 12 seropositive samples that were negative by other HIV-1 diagnostic tests (PBMC coculture and serum p24 antigen detection), 11 were positive by PCR. PCR using PBMC lysates is a very sensitive method of detecting HIV-1 proviral sequences. The use of nested primers appears to increase the sensitivity of the procedure.

Absence of infectious HIV-1 in the urine of seropositive viremic subjects.

Urine and peripheral blood samples from 48 human immunodeficiency virus type 1 (HIV-1) seropositive individuals (38 adults and 10 children) were evaluated for the presence of HIV-1 by cocultivation and for HIV-1 p24 antigen by ELISA. None of the urine samples contained replication-competent HIV-1; 41 (85%) of 48 simultaneously obtained peripheral blood mononuclear cell samples contained replication-competent HIV-1. None of 26 urine samples available for analysis contained HIV-1 p24 antigen as determined by ELISA; 12 (34%) of 35 simultaneously obtained peripheral blood samples had detectable serum HIV-1 p24 antigen. Two of the individuals studied had HIV nephropathy, three had pyuria, and five had microscopic hematuria. Culture sensitivity was maximal when mycostatin (and not amphotericin B) was used as an antifungal agent. Our findings indicate that urine from HIV-1-seropositive individuals is unlikely to contain infectious HIV-1. This would imply that the risk of transmission of HIV-1 by urine is low to nonexistent.

The Miami Heart Institute information system.

The Miami Heart Institute automation project, conceived as a comprehensive unified hospital information system, has been in continuous development since 1969. As of February 1978, the system supports medical services and laboratories as well as teaching, financial, administrative, and research applications through approximately 100 remote terminals. It is controlled by a single operating system serving interrelated data bases and is available to its users practically 24 hours a day, 7 days a week. The information system transfers data to and from dedicated mini- and microcomputer systems and incorporates digital and analog instrumentation interfaces that include physiologic signal-processing capabilities. Acceptance by user departments ranges from good to excellent, whereas acceptance by the private attending staff at large has been only fair. This report represents a general overview of several major subsystems and discusses advantages and shortcomings of the project.