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Biomedical subjects

N Abdala

Publications and source records attributed to N Abdala.

13 recordsLinked to original sources

Can HIV-1-contaminated syringes be disinfected? Implications for transmission among injection drug users.

Bleaching of syringes has been advocated to prevent HIV-1 transmission among injection drug users (IDUs). Bleach is frequently distributed by needle exchange, outreach, and educational programs targeting IDUs. We applied a sensitive HIV-1 microculture assay to determine the effectiveness of bleach in disinfecting syringes contaminated with HIV-1. This study demonstrates that in a laboratory environment designed to replicate injection behaviors, undiluted bleach is highly effective in reducing the viability of HIV-1 even after minimal contact time. However, it did not reduce the HIV-1 recovery to zero. Furthermore, three washes with water were nearly as effective as a single rinse with undiluted bleach in reducing the likelihood that contaminated syringes harbored viable HIV-1. Given the reality that IDUs share syringes and may not have access to a new, sterile syringe for each injection, the results suggest that they should be encouraged through harm reduction interventions to clean their syringes, preferably with undiluted bleach.

Disinfectants↗

Use of ethylene vinyl alcohol copolymer for tubal sterilization by selective catheterization in rabbits.

PURPOSE: To assess the efficacy of ethylene vinyl alcohol copolymer (Uryx) in nonsurgically occluding the fallopian tube and achieving tubal sterilization in the rabbit model. MATERIALS AND METHODS: Ten mature virgin female New England rabbits underwent transvaginal selective bilateral fallopian tube cannulation with use of a coaxial catheter system under general anesthesia. Selective salpingography was performed bilaterally to assess patency of the fallopian tubes. Ethylene vinyl alcohol copolymer was injected unilaterally through a microcatheter to completely fill the middle portion of the tube. Three to seven days after injection, each animal was bred. Conception was determined by ultrasonography (US) 7-19 days after effective breeding. If pregnant, the rabbit was killed. Otherwise, it was permitted to rebreed until pregnancy was achieved. Histologic specimens of the fallopian tubes were prepared and analyzed. RESULTS: Patency of the fallopian tubes was demonstrated bilaterally in all animals by the free spillage of contrast material into the peritoneum. The delivery of ethylene vinyl alcohol copolymer into the fallopian tubes was successful in all animals but one, in which most of the plug almost immediately extruded into the uterus. Pregnancy was detected by US in the untreated fallopian tube in the nine rabbits that were receptive to breeding. No pregnancies were detected in the injected side. Histologic analysis demonstrated variable degrees of occlusion, fibrosis, and inflammation, with the majority of specimens demonstrating mild to moderate inflammation and moderate to marked fibrosis. CONCLUSION: Ethylene vinyl alcohol copolymer can reliably be placed nonsurgically via the transvaginal approach into the fallopian tubes with use of a coaxial catheter system. Ethylene vinyl alcohol copolymer appears to result in less fibrosis than previously investigated agents and demonstrates a 100% early sterilization rate in the rabbit model.

Animals↗

[Multiple gliomas. Illustrative cases of 4 different presentations].

Multiple gliomas are uncommon and may be classified according to: a) the time of presentation in early (at diagnosis) or late (during treatment); b) the characteristics of computed tomography or magnetic resonance imaging (CT/MRI) in multifocal (with evidence of spread) and multicentric (without evidence of spread). From 212 patients with histopathologic diagnosis of glioma evaluated from March/90 to September/99, 15 (7%) had multiple lesions. We describe 4 patients: early multicentric, late multicentric, early multifocal and late multifocal, with emphasis on characteristics of CT/MRI and possible differential diagnosis. The differential diagnosis of multiple lesions in the central nervous system includes mainly infectious/inflammatory diseases and metastasis, however multiple gliomas should always be considered, even in patients with known systemic cancer, as described by others. Considering that CT/MRI features are not definite, the diagnosis should always be confirmed by histopathologic examination.

Adult↗

Survival of HIV-1 in syringes: effects of temperature during storage.

In a previous paper we demonstrated that HIV-1 survival in syringes was strongly associated with the volume of blood remaining and with the duration of storage at room temperature. The current study was performed to determine the effects of storage temperature upon the survival of HIV-1 inside syringes. At 4 degrees C, 50% of all syringes contained viable HIV-1 at 42 days of storage, the longest storage duration tested. At room temperature (20 degrees C), the last day that syringes with 2 microL of infected blood were positive was Day 21, and viable HIV-1 was recovered from 8% of syringes. The last day on which syringes with 20 microL were positive was Day 42, and viable HIV-1 was recovered from 8% of syringes. Above room temperature (27, 32, and 37 degrees C), the likelihood of encountering syringes with viable HIV-1 when periods of storage exceeded 1 week decreased to less than 1%. The temperatures at which drug injectors are likely to store their used syringes will vary according to climate, season, and circumstances faced by the injector. The survival of HIV-1 in contaminated syringes varied over a range of temperatures, and this may be a factor influencing the syringe-borne transmission of HIV-1.

Acquired Immunodeficiency Syndrome↗

Viability of HIV-1 in syringes: implications for interventions among injection drug users.

We have determined that the duration of survival of HIV-1 in syringes typically used by injectors of illicit drugs can exceed 6 weeks. The percentage of syringes with viable virus varied with the volume of blood remaining in the syringes and the temperature at which syringes were stored. These experiments underscore the need for needle exchange programs and other HIV prevention interventions that promote the availability of clean syringes and the removal of potentially infectious ones from circulation.

Acquired Immunodeficiency Syndrome↗

HIV-1 transmission in injection paraphernalia: heating drug solutions may inactivate HIV-1.

In response to recent concerns about risk of HIV-1 transmission from drug injection paraphernalia such as cookers, ethnographic methods were used to develop a descriptive typology of the paraphernalia and practices used to prepare and inject illegal drugs. Observational data were then applied in laboratory studies in which a quantitative HIV-1 microculture assay was used to measure the recovery of infectious HIV-1 in cookers. HIV-1 survival inside cookers was a function of the temperature achieved during preparation of drug solutions; HIV-1 was inactivated once temperature exceeded, on average, 65 degrees C. Although different types of cookers, volumes, and heat sources affected survival times, heating cookers 15 seconds or longer reduced viable HIV-1 below detectable levels.

Cooking↗

Survival of HIV-1 in syringes.

We performed a study to determine the duration of survival of HIV-1 in syringes typically used by injectors of illicit drugs (IDUs). We describe the effectiveness of a microculture assay in detecting viable virus in volumes of blood typical of those commonly found inside used syringes. Using this assay and modeling the worse-case situation for syringe sharing, we have recovered viable, proliferating HIV-1 from syringes that have been maintained at room temperature for periods in excess of 4 weeks. The percentage of syringes with viable virus varied with the volume of residual blood and the titer of HIV-1 in the blood. These experiments provide a scientific basis for needle exchange schemes, harm reduction, and other interventions among IDUs that support the nonsharing and removal of used syringes from circulation.

Acquired Immunodeficiency Syndrome↗

[Magnetic resonance in HTL-I associated myelopathy. Leukoencephalopathy and spinal cord atrophy].

Cerebral white matter lesions and spinal cord atrophy have been frequently reported in patients with HTLV-I associated myelopathy (HAM). The exact frequency and the clinical relevance of these findings still remain to be elucidated. Twenty-nine patients with HAM were studied by magnetic resonance imaging of the brain and spine. Cerebral white matter lesions equal or over 3 mm in diameter were considered abnormal. The spinal cord size was evaluated using an index we have called "spinal cord index". The radiological findings were correlated to the clinical features of the myelopathy. Cerebral white matter lesions occurred in 52% of the patients, and spinal cord atrophy in 74%. There was no significant correlation between these abnormalities and the clinical features studied. These findings suggest that the resonance imaging is a useful method for detection of cerebral and spinal cord abnormalities in HAM patients. The absence of correlation between cerebral white matter lesions and either patient age or risk factors for cardiovascular disease suggests a possible association between the leukoencephalopathy and the infection.

Adult↗

[Orbital phlebography evaluation in 8 cases of Tolosa-Hunt syndrome].

Tolosa-Hunt syndrome (THS), or painful ophthalmoplegia is associated to a non-specific granulomatosis of unknown etiology, that involves the superior orbital fissure and its nervous and vascular structures. The clinical picture that responds to steroid therapy, is variable and is always associated with pain. Inflammatory conditions, tumors and aneurysms can produce similar symptoms. Computed tomography, cerebral angiography and orbital phlebography are the imaging methods of choice for making the diagnosis. We revised the results of these radiological examinations of eight patients seen at the Hospital São Paulo from 1989 to 1991, with the diagnosis of THS according to Hunt and Hannerz criteria. The analysis of orbital phlebographic changes based upon Hannerz et al. systematization showed non-specific features, but those were able to help the diagnosis.

Adult↗

[Computed tomography in methanol intoxication].

We had the opportunity to follow a methanol intoxication case with CT scans, at the 1st and 6th day after admission. Symmetrical putaminal and white matter lesions were seen on the last CT examination, and occurred with the worsening of neurological manifestations, despite the appropriated treatment. The CT demonstration of brains lesions disclosed the toxic effect of the methanol and could be a guideline to the neurological prognosis.

Acidosis, Respiratory↗

Measles and measles vaccination in isolated Amerindian tribes. II. The 1978/79 Xingu epidemic.

Vaccine induced measles antibody titers in the Upper Xingu Indians remained at satisfactory levels without evidence of decline over a period of six years without re-exposure. However, in another area, a vaccination program which used a reduced dose of vaccine was only 63% effective. When measles virus was introduced to the latter area a protracted epidemic ensued with 23% of the population becoming ill and six deaths. The deaths occurred exclusively under 13 months or over 40 years of age.

Adolescent↗