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Biomedical subjects

A M Elliott

Publications and source records attributed to A M Elliott.

At least 55 records · Page 3Linked to original sources
PubMed1995

Failure of drug penetration and acquisition of drug resistance in chronic tuberculous empyema.

We describe a patient with drug-resistant chronic tuberculous empyema in whom substantial differences between achievable pleural fluid and serum drug concentrations were displayed. The ratio of maximum concentration in pleural fluid to serum was especially low for rifampin (4%) but was also low for streptomycin (34%) and ofloxacin (48%). Subtherapeutic drug concentrations in the pleural fluid may have contributed to acquisition of drug resistance in this case.

Aged↗
PubMed1995

The impact of human immunodeficiency virus on response to treatment and recurrence rate in patients treated for tuberculosis: two-year follow-up of a cohort in Lusaka, Zambia.

To examine the effect of HIV on response to treatment and recurrence rate in patients with tuberculosis (TB), we have followed 239 previously untreated, adult, TB patients in a prospective cohort study in Lusaka, Zambia. One hundred and seventy-four (73%) were HIV-1 antibody positive. Patients with sputum smear positive, miliary, or meningeal TB were prescribed 2 months daily streptomycin, thiacetazone, isoniazid, rifampicin, pyrazinamide followed by 6 months thiacetazone and isoniazid; others, 2 months streptomycin, thiacetazone and isoniazid followed by 10 months thiacetazone and isoniazid. Thirty-five per cent of HIV-positive (HIV+ve) and 9% of HIV-negative (HIV-ve) patients were known to have died before the scheduled end of treatment. Surviving HIV+ve patients showed weight gain and improvement in symptoms and laboratory and radiological findings similar to HIV-ve patients. The risk of cutaneous drug reaction was 17% (95% CI: 12-25%) in HIV+ve, and 4% (1-13%) in HIV-ve patients. Severe rashes were attributed to thiacetazone. Recurrence of active TB was examined among 64 HIV+ve and 37 HIV-ve patients who successfully completed treatment, with mean follow-up after the end of treatment of 13.5 and 16.8 months, respectively. The rate of recurrence was 22/100 person years (pyr) for HIV+ve patients and 6/100 pyr for HIV-ve patients, giving a recurrence rate ratio of 4.0 (95% CI 1.2-13.8, P = 0.03).

AIDS-Related Opportunistic Infections↗
PubMed1993

Negative sputum smear results in HIV-positive patients with pulmonary tuberculosis in Lusaka, Zambia.

During recruitment to a prospective study of tuberculosis patients in Lusaka, Zambia, 109 had pulmonary disease proven by sputum culture for Mycobacterium tuberculosis, of whom 72 were HIV-1 antibody-positive and 37 were HIV-negative. Among these culture-proven cases, 43% of the HIV-positive patients had a negative sputum smear, compared with 24% of the HIV-negative cases. There was a strong trend towards lower grade or negative sputum smear in the HIV-positive group (P = 0.003). HIV-positive cases also had lower colony counts on culture and colonies took longer to appear. The findings imply that cases of HIV-associated pulmonary tuberculosis may frequently be missed and emphasise the need for new diagnostic methods.

AIDS-Related Opportunistic Infections↗
PubMed1993

The impact of HIV on infectiousness of pulmonary tuberculosis: a community study in Zambia.

OBJECTIVE: To examine the impact of HIV on infectiousness of pulmonary tuberculosis (TB). DESIGN: A cross-sectional tuberculin survey carried out among household contacts of HIV-1-positive and negative patients with bacteriologically confirmed pulmonary TB. Contacts were also examined for active TB. SETTING: Index cases were recruited from patients attending the University Teaching Hospital in Lusaka, Zambia and household contacts were examined during visits to their homes within Lusaka. PATIENTS, PARTICIPANTS: A total of 207 contacts of 43 HIV-positive patients, and 141 contacts of 28 HIV-negative patients with pulmonary TB were examined. MAIN OUTCOME MEASURES: Proportion of contacts of HIV-positive and negative index cases with a positive tuberculin response (diameter of induration > or = 5 mm to a dose of 2 tuberculin units). RESULTS: Fifty-two per cent of contacts of HIV-positive pulmonary TB patients had a positive tuberculin response compared with 71% of contacts of HIV-negative patients (odds ratio, 0.43; 95% CI, 0.26-0.72; P < 0.001). This difference persisted after allowing for between-household variations in the tuberculin response. Tuberculin response in the contact was related to age of contact, intimacy with the index case and crowding in the household. However, the effect of HIV status of the index case was not confounded by these variables. Tuberculin response in the contact was also related to the number of bacilli seen in the sputum smear of the index case which partially explained the effect of HIV status of the index case. Active TB was diagnosed in 4% of contacts of HIV-positive and 3% of contacts of HIV-negative cases, respectively (P = 0.8). CONCLUSIONS: HIV-positive patients with pulmonary TB may be less infectious than their HIV-negative counterparts and this may partly be explained by lower bacillary load in the sputum.

Adolescent↗
PubMed1993

The value of wide-needle aspiration in the diagnosis of tuberculous lymphadenitis in Africa.

OBJECTIVES: To evaluate wide-needle (19-gauge) aspiration in the diagnosis of tuberculous lymphadenitis. SETTING: Department of Surgery, University Teaching Hospital, Lusaka, Zambia. PATIENTS: Three hundred and four patients presenting to one surgeon for diagnostic surgical biopsy of a peripheral lymph node during 1989-1990. DESIGN: Prospective study in which wide-needle aspiration routinely preceded open surgical biopsy. MAIN OUTCOME MEASURES: Histology and mycobacterial culture of the surgically biopsied lymph node; HIV-1 serology; successful aspiration of material, naked-eye appearance of aspirate, presence of acid-fast bacilli and/or microscopic caseation in the aspirate. RESULTS: One hundred and eighty-eight out of 304 (61.8%) patients had histologically and/or culture-proven tuberculous lymphadenitis, of whom 155 out of 183 (84.7%) tested HIV-1-seropositive. Material was successfully aspirated from 180 out of 188 (95.7%) of patients with proven tuberculous lymphadenitis. Macroscopic caseation, diagnosable on naked-eye examination alone of the aspirate, was present in 49 out of 120 (40.8%) consecutive aspirates from tuberculous nodes. Acid-fast bacilli and/or microscopic caseation were seen in 116 out of 155 (74.8%) aspirates from tuberculous nodes for which smears stained both by Ziehl-Nielsen and haematoxylin & eosin were available. CONCLUSIONS: It is recommended that all patients with suspected tuberculous lymphadenitis in Africa, undergo wide-needle aspiration before surgical biopsy or empirical treatment.

Adolescent↗
PubMed1993

Immunoglobulin G subclass responses to mycobacterial lipoarabinomannan in HIV-infected and non-infected patients with tuberculosis.

Immunoglobulin G subclass responses to lipoarabinomannan (LAM) of Mycobacterium tuberculosis were determined by ELISA in both HIV-1 antibody positive (n = 31) and negative (n = 43) patients with tuberculosis (TB). Responses were also studied in a group of healthy controls (n = 16) and HIV-1 antibody positive (n = 60) individuals without TB. IgG2 antibodies were the predominant subclass, being present in 25 of 43 non-HIV-infected TB patients (58%) and in 11 of 31 HIV-infected TB patients (35%). However, HIV+ TB patients also showed IgG4 (n = 16; 52%), and IgG1 (n = 4, 13%) responses to LAM, whereas these subclasses were absent in sera from HIV-TB patients. Individuals in both non-tuberculous control groups showed no antibody responses to LAM. The influence of HIV infection on B cell responses to LAM, and possible mechanisms for antibody-mediated regulation of immunity to TB, are explored.

Adolescent↗
PubMed1993

The impact of human immunodeficiency virus on presentation and diagnosis of tuberculosis in a cohort study in Zambia.

Two hundred and forty-nine patients with tuberculosis were recruited to a cohort study to investigate the interaction between tuberculosis and HIV in Lusaka, Zambia; findings at presentation are presented here. One hundred and eighty-two (73%; 95% confidence interval 67-79%) of the cases were HIV-1 antibody positive. The diagnosis of tuberculosis was confirmed by microscopy for acid-alcohol fast bacilli, culture of Mycobacterium tuberculosis, or histology in 74% of all cases. HIV negative and positive cases differed in site of disease: among HIV negative patients 72% had pulmonary disease alone, 16% extrapulmonary disease alone and 12% had both, whereas among HIV positive patients 40% had pulmonary disease alone, 34% extrapulmonary disease alone and 26% both (P < 0.001). HIV negative and positive cases were compared with regard to outcome of diagnostic procedures: 55% of HIV negative cases could be diagnosed at enrollment by sputum smear, but only 35% of HIV positive cases (P < 0.01). Among pulmonary cases confirmed by sputum culture, 76% of HIV negative patients had a positive sputum smear, compared with 57% of HIV positive patients (P = 0.09). Pleural and pericardial disease were difficult to confirm, but culture of pleural fluid was positive in 12/46 HIV positive patients, compared with 0/11 HIV negative patients. Lymph node disease was readily confirmed by biopsy. The tuberculin test was positive in only 30/110 (27%) of HIV positive cases, but in 21/38 (55%) of HIV negative cases (P < 0.01). Mycobacterium tuberculosis was cultured in 57% of HIV negative cases and 54% of HIV positive cases; no atypical mycobacteria were isolated. Initial resistance to isoniazid was present in isolates from 5% of cases with a positive culture.

Adolescent↗
PubMed1992

Effect of coolant flow on the performance of round sapphire tips in a saline field.

Round sapphire and silica tips have been studied as surgical probes for focusing Nd:YAG laser radiation during various surgical indications. Since most of these data have been obtained with silica tips from Surgical Laser Technology, there are limited data on the physical performance of round sapphire tips. An investigation of round sapphire tip performance during tissue ablation was undertaken. Nd:YAG laser power was delivered in repetitive 2-sec exposures to a round sapphire tip placed on fresh skinned chicken breast. Total exposures of 1,000 J were performed at different saline perfusion rates. The tip's performance in terms of tissue perforation rate, blanched tissue area, tissue heating rate, and forward transmission was measured. Best tip performance occurred at the lowest cooling rates and was independent of the tip's forward transmission value. No physical deterioration of the tip's optical surface was observed. Round sapphire tip performance in a saline field is primarily determined by the tip's temperature.

Aluminum Oxide↗
PubMed1992

An approach to the management of tuberculosis in HIV endemic areas.

The epidemic of HIV-associated tuberculosis is having a severe impact on tuberculosis control in sub-Saharan Africa, as well as the United States of America, and is expected to spread. Where facilities are limited, the association between HIV and sputum-smear negative tuberculosis hampers diagnosis; trials of anti-tuberculous therapy are indicated in some cases. Standard treatment regimens are effective, but thiacetazone should be avoided because of its association with severe, cutaneous adverse reactions. Treatment may have to be prolonged in HIV positive cases. Measures to maximize compliance with therapy are paramount. These include the use of the shortest possible regimens, of recognized potency, and emphasis on ensuring that the regimen is understood by and readily accessible to the patient.

HIV Infections↗
PubMed1990

Impact of HIV on tuberculosis in Zambia: a cross sectional study.

OBJECTIVE: To examine the contribution of HIV infection to the apparently increasing incidence of tuberculosis in central Africa. DESIGN: Cross sectional study. SETTING: Outpatient clinic in teaching hospital, Lusaka, Zambia. PATIENTS: 346 Adult patients with tuberculosis. RESULTS: Overall, 206 patients (60%; 95% confidence interval 54% to 65%) were positive for HIV: in one or both assays used. The peaks for both tuberculosis and HIV infection were among men aged 25-34 years and women aged 14-24 years. Of patients with confirmed pulmonary tuberculosis, 73/149 (49%; 41% to 57%) were positive for HIV; 67/83 (81%; 70% to 89%) patients with pleural disease and 16/19 (84%; 60% to 97%) patients with pericardial disease were positive. HIV positive patients with positive sputum culture were less likely to have had a positive sputum smear, and their chest x ray films less often showed classic upper zone disease or cavitation. Of 72 patients who fulfilled clinical criteria for AIDS, 17 were negative for HIV. CONCLUSIONS: The high prevalence of HIV in patients with tuberculosis suggests that an epidemic of reactivating tuberculosis is arising in those who are infected with HIV. The redirection of public health priorities towards tuberculosis would focus on a major treatable and preventable complication of the AIDS epidemic.

Adolescent↗
PubMed1985

Cefotaxime aminoglycoside interactions.

Minimum inhibitory concentrations and minimum bactericidal concentrations were determined for cefotaxime, gentamicin, tobramycin and amikacin and for the combination of cefotaxime and each of the aminoglycosides in vitro against 200 strains of Enterobacteriaceae. 91% were susceptible to cefotaxime, 93.5% were susceptible to gentamicin, 89.5% were susceptible to amikacin and 68% were susceptible to tobramycin. There were 95 strains which could be evaluated for synergistic killing by the antimicrobial combinations. Synergism was shown against 78% of strains by cefotaxime and amikacin, against 71% by cefotaxime and tobramycin and against 64% by cefotaxime and gentamicin. In 19 of 22 instances where a bacterial strain was resistant to both cefotaxime and the aminoglycoside, synergistic killing with clinically achievable levels of both antimicrobial agents was demonstrated. There was no significant decrease in concentration of any of the three aminoglycosides after incubation with cefotaxime at 37 degrees C for 0, 4 or 24 h.

Aminoglycosides↗
PubMed1984

Elevated serum D-arabinitol levels in patients with sarcoidosis.

D-Arabinitol has been found in the serum of patients with candidiasis in an incidence varying from 38 to 82%. While screening serum by gas chromatography for the presence of this sugar, we observed elevated concentrations in several patients with sarcoidosis. In an attempt to determine the significance of this chance observation, we tested serum from additional patients with sarcoidosis along with serum from patients with other clinical conditions known to be associated with elevated D-arabinitol levels. Of 53 patients with sarcoidosis, 27 (51%) had elevated concentrations of this compound. Only one of these patients had decreased renal function (creatinine, 2.5 mg/dl). We were unable to correlate elevated values with extent of the disease. Although the significance of this finding is not clear, it may represent a clue to the pathogenesis of sarcoidosis.

Adolescent↗
PubMed1983

Interaction of cefotaxime and aminoglycosides against enterococci in vitro.

The antibacterial activities of cefotaxime, gentamicin, tobramycin, and amikacin as well as the combinations of cefotaxime and aminoglycosides were tested against 50 strains of enterococci. Synergy studies were performed by the time-kill method, and with this technique the combination of cefotaxime plus gentamicin appeared to be more active than the combination of cefotaxime plus tobramycin or cefotaxime plus amikacin. Results of this in vitro study suggest cefotaxime and gentamicin may provide some activity against enterococci, although not sufficient to substitute for proven therapy such as penicillin-ampicillin and gentamicin.

Amikacin↗
PubMed1982

Ceftriaxone: in vitro studies and clinical evaluation.

The in vitro activity of ceftriaxone against 437 clinical isolates of gram-negative bacilli was determined. Ceftriaxone was found to have high in vitro activity against Enterobacteriaceae, with the exception of Enterobacter cloacae. Ceftriaxone was only minimally active against Pseudomonas aeruginosa and Acinetobacter calcoaceticus. We evaluated the clinical efficacy and toxicity of ceftriaxone in 55 adult patients. Bacterial infection was confirmed by the isolation of etiological bacteria in 30 patients. Infectious disorders treated included 10 pneumonias, 13 urinary tract infections, and 7 soft tissue or bone infections. Pathogens identified were 25 isolates of gram-negative bacilli, 5 isolates of Staphylococcus aureus, 5 isolates of pneumococci, and 4 isolates of other streptococci. The overall efficacy of ceftriaxone was excellent. The clinical cure rate was 93%, and the bacteriological cure rate was 93%. A total of 30 adverse reactions were noted in 22 of 55 patients receiving ceftriaxone, but only one necessitated discontinuation of treatment. Adverse effects frequently noted were elevated hepatic enzymes (16%), thrombocytosis (16%), and eosinophilia (8%). Ceftriaxone is an effective and well-tolerated antimicrobial agent that appears promising for the treatment of serious gram-negative bacillary infections.

Adolescent↗