Development and evaluation of NucliSens basic kit NASBA for diagnosis of parainfluenza virus infection with 'end-point' and 'real-time' detection

New methods for the detection of human parainfluenza viruses (HPIVs) were developed. These were based on nucleic acid sequence-based amplification (NASBA) and utilised the NucliSens Basic Kit. Primers and probes were selected from the haemagglutinin neuraminidase (HN) gene of HPIV1, HPIV2 and HPIV3, and from the phosphoprotein (P) of HPIV4a and -4b. Synthetic RNA, titrated control virus stocks and respiratory specimens (n=44) were utilised to evaluate performance of the assays. Detection of NASBA products was by probe hybridisation and electrochemiluminescence (ECL) ('end-point' detection) or using molecular beacons ('real-time' detection). The assays using ECL detection proved to be both sensitive and specific. Typically, less than or equal to 100 RNA copies or one TCID(50) input was detectable with no cross-reaction between the specific HPIV assays and other respiratory viruses. Results for clinical samples were concordant with those obtained by 'conventional' procedures by classical viral diagnostic methods. 'Real-time' detection utilised probes specific for either HPIV1 or HPIV3 with similar performance characteristics to the assays with 'end-point' detection. The feasibility of multiplexing targets together was confirmed using a combined HPIV1 and HPIV3 assay with good results for ECL and molecular beacon detection on control material and clinical samples.     

Left ventricular outflow tract obstruction associated with chronic ventricular assist device support

Favorable long-term patient outcome after insertion of a left ventricular assist device (LVAD) as a bridge to recovery or destination therapy for the treatment of end-stage cardiomyopathy is adversely affected by pathophysiologic changes affecting the heart. Alterations in the native aortic valve apparatus, specifically aortic valve cusp fusion, is an example of such a phenomenon and may especially affect patients in cases of bridge to recovery, a rare but reported event. A retrospective review of the last 33 LVAD placements at our institution was conducted, including reviews of operative reports and pathologic examinations of the native hearts. Seven hearts were found to have varying degrees of aortic valve cusp fusion after chronic LVAD support (63-1, 339 days). Five of these patients had native aortic valves, and two had bioprosthetic valves. The left ventricular outflow tracts in two patients were surgically occluded at the time of LVAD insertion. Aortic valve cusp fusion occurs in roughly 25% of patients on chronic LVAD support. This phenomenon may prove to be clinically significant by creating a potential source of emboli and infection. In addition, in the case of myocardial recovery, left ventricular outflow tract obstruction could limit parallel flow and produce suprasystemic ventricular pressures that in turn would elevate left ventricular end diastolic pressures. The latter may contribute to further myocardial injury, ultimately limiting the ability of an otherwise recovered heart to be weaned from LVAD support.     

A mathematical simulation of the AIDS patient and extracorporeal detoxification

A simple numerical simulation of AIDS patient detoxification by a hypothetical extracorporeal device for the removal of viruses, infected white cells, and syncytia has been designed. The mathematical model accounts for healthy blood white cells attacking and destroying the viruses, while at the same time the viruses attack and infect certain white cells. The infected white cells serve as a site for viral growth; eventually the cells lyse, releasing a large number of viruses into the blood stream. The healthy white cells and infected white cells combine to form syncytia, where the virus multiplies, and finally the syncytium ruptures releasing all the virus. This model can be used to predict concentrations over a specified period for the patient. This is a mathematical model to be used as a research and design tool only.     

Markers in HIV associated tuberculosis in Kenya

Tuberculosis is one of the most frequent opportunistic infections in HIV-infected patients in developing countries. In some instances, manifestations of pulmonary tuberculosis precede all other HIV related signs and symptoms because of the high virulence of M. tuberculosis. In order to characterise the interaction between these two pathogens, clinical and immunological parameters in pulmonary tuberculosis patients with and without HIV infection were compared. Amongst newly diagnosed pulmonary tuberculosis patients the association of some of these changes with the clinical outcome were evaluated. Of these, 44% were co-infected with HIV. Pulmonary tuberculosis patients with HIV-1 presented more frequently with lymphadenopathy and diarrhoea than those without HIV-1. Peripheral blood CD4+ counts were significantly lower in patients with pulmonary tuberculosis with HIV-1 than those with pulmonary tuberculosis alone, P= 0.0292. Low CD4+ lymphocyte counts, lymphadenopathy and BCG scar absence could serve as indicators of HIV-1 infection in pulmonary tuberculosis (PTB) patients.     

Measuring homelessness and residential stability: The residential time‐line follow‐back inventory

Reliable and valid longitudinal residential histories are needed to assess interventions to reduce homelessness and increase community tenure. This study examined the test‐retest reliability, sensitivity to change, and concurrent validity of the Residential Time‐Line Follow‐Back (TLFB) Inventory, a method used to record residential histories in the Collaborative Program to Prevent Homelessness (n = 1,381). The Residential TLFB Inventory yielded temporally stable aggregate measures of duration in residential categories, and it revealed significant differences in change over time when contrasting study groups. A comparison of agency and participant data at one site.     

Stability of a mobile electron linear accelerator system for intraoperative radiation therapy

The flexibility of mobile electron accelerators, which are designed to be transported to an operating room and plugged into a normal 3-phase outlet, make them ideal for use in intraoperative radiation therapy. However, their transportability may cause trepidation among potential users, who may question the stability of such an accelerator over a period of use. In order to address this issue, we have studied the short-term stability of the Mobetron system over 20 daily quality assurance trials. Variations in output generally varied within +/-2% for the four energies produced by the unit (4, 6, 9, and 12 MeV) and changes in energy produced an equivalent shift of less than 1 mm on the depth-dose curve. Hours of inactivity, with the Mobetron powered on for use either throughout the day or overnight, led to variations in output of about 1%. Finally, we have tested the long-term stability of the absolute dose output of the Mobetron, which showed a change of about 1% per year.     

Health seeking behavior by families of children suspected to have malaria in Kabale: Uganda

Background

Malaria is common among communities of Kabale district, and many young children die of the illness. Despite a good distribution of health facilities, able to handle malaria patients, families and individuals tend to depend on self-treatment, or private clinics where drugs used may be of doubtful quality. This study reports on health seeking behaviour by families with children suspected to have malaria.

Methodology

A community-based, cross-sectional survey among 209 rural peasant families living in 12 villages, chosen from the 5 most malaria-affected sub-counties was done. Using a questionnaire, respondents'' reactions to the disease and what decisions they took were recorded. Reasons for choices such as drugs used, location of treatment and malaria control methods were recorded.

Results

Ninety seven percent lived within easy reach of a public health facility. Over 2/3 knew how malaria was transmitted and how it presented. They believed it was best treated at public heath facilities using western type of medicine. Fifty percent of the children, who attended public health units, were treated within 24 of illness. Thirty eight percent of the caretakers knew how to correctly use chloroquine. The caretakers relied on fever, vomiting and refusal to feed as the main symptoms for their diagnosis of malaria. Only 31% of the families sought treatment from government health facilities.Fifty three percent of the families sought treatment from drug shops/vendors. Unfortunately only 38% of the families knew the correct regimen of chloroquine, 4.3% for sulpha-doxine pyrimethamine and 0.5% for quinine. One quarter could afford malaria treatment, and one out of five missed treatment because of poverty. Concerning prevention, 90% stated at least one method but only 21.2% used them.

Conclusions

Despite reasonable knowledge for diagnosis of malaria, awareness of correct treatment is limited. Paradoxically government health units appear to play a minor role in the treatment of malaria.     

Identification of tumor suppressor loci on the long arm of chromosome 15 in primary small cell lung cancer

Small cell lung cancer (SCLC) frequently shows a loss of heterozygosity (LOH) on chromosome 15q. In order to define the commonly affected region on chromosome 15q, we tested 23 primary SCLCs by microsatellite analysis. By analyzing 43 polymorphic microsatellite markers located on chromosome 15q, we found that 14 (60.8%) of 23 tumors exhibited a LOH in at least one of the tested microsatellite markers. Two (14.3%) of the 14 tumors were found to have more than a 50% LOH on chromosome 15q. LOH was observed in five commonly deleted regions on 15q. Of those regions, LOH from D15S1012 to D15S1016 was the most frequent (47.8%). LOH was also observed in more than 20-30% of tumors at four other regions, from D15S1031 to D15S1007, from D15S643 to D15S980, from D15S979 to D15S202, and from D15S652 to D15S642. Four of the 23 tumors exhibited shifted bands in at least one of the tested microsatellite markers. Shifted bands occurred in 3.2% (29 of 914) of the loci tested. Our data suggests the presence of at least five tumor suppressor loci on chromosome 15q in SCLC, and further that these may play an important role in SCLC tumorigenesis.