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Biomedical subjects

H Levy

Publications and source records attributed to H Levy.

At least 91 records · Page 5Linked to original sources

A preliminary report of the collaborative study of maternal phenylketonuria in the United States and Canada.

The Maternal Phenylketonuria Collaborative Study (MPKUCS), encompassing all the United States and provinces of Canada, is a prospective, longitudinal investigation designed to ascertain the efficacy of phenylalanine-restricted therapy in protecting the fetus from high maternal phenylalanine concentrations in women with hyperphenylalaninaemia. Preliminary findings are reported for 147 pregnancies for whom the recommended therapeutic range of blood phenylalanine was 120-360 mumols/L. Sixty-three pregnancies had complete data for analysis. Dietary control was attempted prior to conception in 10 out of 63 women. Significant negative correlations were noted in length, weight and head circumference and blood phenylalanine concentrations during pregnancy. Average reported phenylalanine levels by trimester for 63 hyperphenylalaninaemic pregnancies resulting in live births revealed that no group requiring treatment achieved levels below 360 mumols/L until the third trimester. Median birth measurement percentiles revealed that all groups studied generally had smaller head size compared with birth length and weight. Those started on diet after the first trimester achieved a head circumference below the 10th percentile. The implication of small head circumference for subsequent intellectual development is unclear at this time. Furthermore, the study must evaluate more offspring of women having optimal preconception and pregnancy restriction of phenylalanine.

Canada↗

MR evaluation of renal space-occupying lesions: diagnostic criteria.

In order to assess the ability of magnetic resonance (MR) imaging to distinguish simple renal cysts from renal tumors, images from 53 patients with 74 lesions were reviewed. MR image characteristics, including signal strength and homogeneity for each lesion, were evaluated and compared with the final diagnoses. There were 53 cysts and 21 tumors. For 56 lesions (76%), MR allowed accurate diagnosis; on T1-weighted images, homogeneous low-intensity lesions were always cysts and inhomogeneous medium- or high-intensity lesions were always tumors. The remaining 18 lesions (24%) could not be distinguished, and T2-weighted images failed to improve differential diagnostic ability. In our experience, MR imaging allows differentiation of renal cysts and tumors less frequently than does computed tomography (CT) or ultrasound (US). MR criteria for simple renal cysts and tumors are offered, with the understanding that modification may be necessary as experience with these lesions increases.

Diagnosis, Differential↗

Klebsiella pneumoniae bacteraemia at an urban general hospital.

Of 47 patients with Klebsiella pneumoniae bacteraemia admitted to the Hillbrow Hospital, Johannesburg during a period of 18 months, 31 were males and 16 were females. Features predisposing to illness were found in 89.4% patients, chronic alcoholism, neoplastic disease and diabetes mellitus being the most common. Twenty-five infections were acquired in hospital and 22 in the community. Most patients (59.6%) had pneumonia. All isolates of K. pneumoniae were resistant to ampicillin (100%); several (42.6%) were resistant to other antibiotics also. The overall mortality rate was 55.3%. A higher mean initial blood pressure and lower concentrations of serum urea and bilirubin were found in survivors. None of the 28 patients, surviving more than 48 h who received combined therapy with an aminoglycoside and a beta-lactam antibiotic (to which the organism was susceptible) died. Among the remaining patients treated with either an appropriate beta-lactam agent alone, an appropriate aminoglycoside alone or ciprofloxacin the combined mortality rate was 83.3% (P = 0.007).

Adolescent↗

Cryptogenic fibrosing alveolitis. A study of an indigenous African population.

Cryptogenic fibrosing alveolitis (CFA) has not been described previously in any large group of indigenous African patients. This was a retrospective study of 46 such patients diagnosed as having CFA during a 73-month period. The clinical spectrum of illness was similar to that of other groups studied worldwide. Cigarette smoking was associated with a poorer outcome and is a potentially preventable cause of deterioration.

Adrenal Cortex Hormones↗

Antimycobacterial antibody levels in pleural fluid as reflection of passive diffusion from serum.

The objective of this study was the prospective evaluation of the relationship between serum and pleural fluid antibody levels to mycobacterial antigens and their role in the diagnosis of tuberculous pleuritis. The setting was a tertiary care medical center. Thirteen patients with tuberculous pleuritis and 53 control subjects with pleural effusion (22 with carcinoma, 17 with cardiac failure, and 14 with empyema or parapneumonic effusion) were studied. The level of IgG was measured by ELISA. The median titers of antibody to both Mycobacterium tuberculosis and M avium were significantly higher in the serum and pleural fluid of the patients with tuberculosis than in the control patients. There was a very close relationship between the levels of M tuberculosis (r = 0.95) and M avium (r = 0.94) antibodies in the serum and pleural fluid. We concluded that the levels of antimycobacterial IgG in pleural fluid, adjusted to constant protein concentration, are very closely related to the serum levels. Therefore, these antibodies in the pleural fluid probably result from passive diffusion from serum and not local production. Measurement of pleural fluid antibody levels will not add diagnostic sensitivity or specificity to that achieved with serodiagnosis.

Antibodies, Bacterial↗

Initial hormonal and metabolic profile in critically ill patients with community-acquired lobar pneumonia.

A prospective study of 18 critically ill patients with community-acquired lobar pneumonia was undertaken at Hillbrow Hospital, Johannesburg, in order to document the initial plasma hormonal and substrate profile as part of the stress response to the infection. The results of these studies, carried out before therapy, were compared with the results in a group of healthy fasting adults. Highly significant (P less than or equal to 0.005) increases in the mean plasma levels of adrenaline, noradrenaline, human growth hormone, cortisol, glucose and free fatty acids were noted in the study group, with a lesser increase in the prolactin concentration (P less than or equal to 0.01). The levels of dopamine, glucagon, insulin and adrenocorticotrophin did not show any significant change. No significant differences were found in the hormonal profile when comparing survivors with non-survivors. The neuro-endocrine hormonal and metabolic responses in pneumonia appear to be similar to those seen in other stress situations and failure of the initial stress response does not appear to contribute to the mortality of critically ill patients with community-acquired lobar pneumonia.

Adult↗

The diagnostic yield of prebronchoscopy sputa and bronchial washings in patients with biopsy-proven pulmonary tuberculosis.

We report on a series of 35 patients with pulmonary tuberculosis diagnosed by flexible fibre-optic bronchoscopy and transbronchial lung biopsy after 3 sputum specimens had been microscopy-negative. This study re-evaluates this invasive procedure. Additional prebronchoscopy specimens of expectorated sputum yielded the diagnosis in 7 of 16 cases (43.8%) on microscopy. Sputum culture results were positive in 12 of 33 (36.4%). Pleural fluid culture was diagnostic in 1 case, and in another miliary tuberculosis was demonstrated on bone marrow trephine biopsy. The availability of these results could therefore have obviated the need for bronchoscopy in 14 of the 35 patients (40%). Bronchial washings were positive for acid-fast bacilli on microscopic examination in 13 of 34 cases (38.2%) and culture-positive in only 18 of 34 (52.9%), and should therefore not be the sole procedure utilised when bronchoscopy is performed. Transbronchial lung biopsy remains a valuable procedure to confirm pulmonary tuberculosis in patients whose sputum is culture-negative for mycobacteria.

Adolescent↗

Endobronchial appearance of tracheobronchial amyloidosis. A case report and suggested classification.

Tracheobronchial amyloidosis with the co-existence of submucosal plaques and tumour-like masses is reported. The subdivision of tracheobronchial amyloidosis into submucosal plaques and tumour-like masses is questioned since there appears to be no difference in their clinical presentation and pathological appearance. It is suggested that lower respiratory tract amyloidosis should be classified into tracheobronchial, nodular parenchymal and diffuse alveolar septal amyloidosis.

Amyloidosis↗

Community-acquired pneumonia of diverse aetiology: prognostic features in patients admitted to an intensive care unit and a "severity of illness" core.

In a retrospective study of 73 patients with community-acquired lobar pneumonia of diverse aetiology admitted to an intensive care unit, an attempt was made to identify those factors among the demographic and clinical features and results of initial laboratory investigations that were predictive of the ultimate outcome. A lower mean white cell count (p = 0.03), platelet count (p = 0.02), total serum protein (p = 0.005) and albumin (p = 0.02) and a higher mean serum creatinine (p = 0.03) and phosphate level (p = 0.02) appeared to be predictive of a poor prognosis. The most significant variable predictive of mortality, was the presence of bacteraemia (p = 0.0005). Severity of illness scoring systems by omitting microbiological data appear to underestimate predicted patient mortality. The mortality rate of critically ill patients with community-acquired lobar pneumonia remains high, despite advances in antimicrobial chemotherapy and intensive care unit facilities, particularly in the presence of certain negative prognostic factors of which the presence of bacteraemia is the most important.

Adult↗

A reevaluation of sputum microscopy and culture in the diagnosis of pulmonary tuberculosis.

This prospective study was undertaken to determine the interpretation of "scanty-positive" acid-fast bacilli on microscopy and to reevaluate simultaneous microscopy and culture of sputum for the accurate diagnosis of pulmonary tuberculosis (PTB). A total of 2,560 specimens were processed from 727 patients. There were 435 positive specimens (17.0 percent), originating from 139 patients, 10 by microscopy only, 176 by culture only, and 249 on both microscopy and culture. Review of the hospital records showed that 107 patients had PTB, 1 had Mycobacterium kansasii colonization, and 31 were thought not to have PTB. Sensitivity and specificity were 53.1 and 99.8 percent for microscopy, 81.5 and 98.4 percent for culture, and 77.6 and 100 percent for microscopy and culture, respectively. Seventy-five microscopy specimens (46 patients) were reported as scanty-positive, of which five (four patients) were deemed false positives, yielding a positive predictive value of 93.3 percent. In those patients with positive sputum microscopy, acid-fast bacilli were detected in one of the first four specimens. Seven isolates (three patients) were mycobacteria other than tubercle (0.27 percent of specimens and 1.6 percent of mycobacteria cultured). Despite the ready availability of laboratory evidence of disease, only 73 percent of cases were diagnosed by ward staff and 36 percent notified by the primary physician. Eleven patients (10.3 percent) died, six of whom had not received diagnoses of PTB before death. Sputum microscopy and culture remains reliable despite Bayesian predictions when applied to a population with a decreasing incidence of tuberculosis.

Bacteriological Techniques↗

Ankylosing spondylitis lung disease and Mycobacterium scrofulaceum.

The development of apical pulmonary fibrosis and bullous disease is a rare but well recognized extra-articular manifestation of ankylosing spondylitis (AS). The fibrobullous disease is usually asymptomatic and diagnosed at an incidental radiological examination. When symptoms do develop, they are usually due to superimposed colonization or infection by bacteria, fungi or mycobacteria. Only six cases of non-tuberculous mycobacterial superinfection in AS have been reported. We report a patient with AS and progressive apical fibrobullous disease in whom Mycobacterium scrofulaceum was repeatedly cultured over a 12-year period.

Adult↗

Enzyme-linked immunosorbent assay for the detection of antibodies against Mycobacterium tuberculosis in bronchial washings and serum.

This prospective study evaluates an enzyme-linked immunosorbent assay (ELISA) for the detection of IgG antibodies against Mycobacterium tuberculosis when applied to serum and bronchial washings (BW) of patients requiring bronchoscopy for definitive diagnosis. The ELISA employed an adsorbed fraction of mycobacterial sonicates as antigen. Of the 57 patients tested, 12 had tuberculosis (TB), 13 had malignant disease, 14 acute pneumonia or chronic destructive pneumonia, 13 had no demonstrable disease, and five had miscellaneous diseases. The mean optical density (OD) at 492 nm for a 1 in 40 dilution of serum of patients with TB was 0.338 +/- 0.218 and for control subjects was 0.162 +/- 0.098 (p = 0.0323). Values for neat BW were 0.317 +/- 0.122 for TB patients and 0.191 +/- 0.140 for control subjects (p = 0.0084). Using stepwise discriminant analysis, the ELISA on serum gave a sensitivity of 70.0 percent and specificity of 86.4 percent and 83.3 percent correct classification. When applied to BW, there was a 72.7 percent sensitivity, a 82.2 percent specificity, and patients were correctly classified in 80.4 percent of cases. It is concluded that the assay is a useful and reliable adjunct to conventional tests for tuberculosis.

Adult↗

The value of bronchial washings and bronchoalveolar lavage in the diagnosis of lymphangitic carcinomatosis.

This study examines the value of bronchoalveolar lavage (BAL) in diagnosing lymphangitic carcinomatosis. A retrospective analysis of fiberoptic bronchoscopic records at a tertiary referral hospital was performed. Twelve patients with neoplastic disease and diffuse pulmonary infiltrates compatible with lymphangitic carcinomatosis who underwent diagnostic fiberoptic bronchoscopy were identified. Bronchoalveolar lavage correctly identified five (100 percent) out of five patients, bronchial washings identified four (57 percent) of seven patients and either procedure identified nine (75 percent) of 12 patients. Bronchial brushings were positive in two (40 percent) of five patients, and transbronchial lung biopsy confirmed the diagnosis in only four (44 percent) of nine patients. Transbronchial lung biopsy was uniquely positive in only one patient. One patient had a significant pulmonary hemorrhage following transbronchial lung biopsy, while no complications of BAL occurred. Two patients had significant coagulopathy, and one patient was severely agitated precluding transbronchial lung biopsy, and all three were positive by BAL. This study suggests that BAL should be performed to confirm the diagnosis of lymphangitic carcinomatosis before proceeding to a biopsy, especially when the risks of pneumothorax and hemorrhage are excessive.

Adult↗

Differentiation of sarcoidosis from tuberculosis using an enzyme-linked immunosorbent assay for the detection of antibodies against Mycobacterium tuberculosis.

This study evaluates the ability of an enzyme-linked immunosorbent assay (ELISA) using adsorbed mycobacterial sonicates as antigen to differentiate between patients with tuberculosis (TB) and patients with sarcoidosis. The study group consisted of 11 patients with active sarcoidosis, seven patients with sputum-positive tuberculosis, and seven normal control subjects. Serum specimens were subjected to ELISA. Serum anti-TB IgG optical density measured at 492 nm (mean +/- SD); pulmonary TB, 0.291 +/- 0.040; normal control subjects, 0.092 +/- 0.011; and sarcoidosis, 0.064 +/- 0.033 (TB vs sarcoid, p less than 10(-6)). This ELISA is a valuable test for the differentiation between sarcoidosis and TB.

Adult↗

Pneumococcal bacteraemia in adults in a low socio-economic urban population.

Between January 1984 and December 1985, 183 adult patients, subsequently shown to have pneumococcal bacteraemia, were admitted. Of these infections, nine were caused by penicillin-resistant strains, and three of these were resistant to other antibiotics. The organisms from 150 patients were serotyped/grouped. The primary site of infection was lung in 90 per cent of patients. Among the patients with pneumonia, those with serovar 3 strains accounted for most intensive care unit admissions, most cases requiring inotropic drugs, and mechanical ventilation and had the highest complication rate and mortality. Findings which predicted the need for intensive care included higher age, elevated concentrations of serum urea, creatinine, and phosphate and lower levels of total serum protein, albumin and calcium. Twenty-four patients died of whom 23 had pneumonia. The case fatality rate among all of the patients admitted to the intensive care unit was 60 per cent and among those not admitted to the unit, 9.2 per cent. Of the patients who died, 41.7 per cent did so within the first five days of admission. The prophylactic use of polyvalent pneumococcal vaccine in industrial workers from low socio-economic groups should be carefully considered.

Adult↗