Biomedical subjects

A Goolam Mahomed

Publications and source records attributed to A Goolam Mahomed.

7 recordsLinked to original sources

PubMed2001

Prognostic factors in severe community-acquired pneumonia in patients without co-morbid illness.

OBJECTIVES: We wished to determine the prognostic factors and the impact of initial empirical antibiotic therapy on the outcome of severe community-acquired pneumonia in patients without underlying co-morbid illness. METHODOLOGY: This is a retrospective record review of consecutive patients with severe community-acquired pneumonia who were divided into those with and without underlying co-morbid illness. RESULTS: There were 182 patients including 112 primary (no co-morbid illness) and 70 secondary (underlying co-morbid illness) pneumonias. The overall mortality was 41.8% and there were no differences in APACHE II score or mortality when comparing cases with primary (37.5%) and secondary infections (48.6%). The mortality was significantly higher in patients with negative microbiology. Univariate analysis identified a number of parameters and various antibiotic regimens, which appeared to be associated with a significantly poorer outcome. On multivariate analysis multilobar pulmonary consolidation, need for mechanical ventilation, inotropes and dialysis were documented to be independent predictors of mortality. Only in their absence could different antibiotic regimens be shown to have an apparent impact on outcome and further analysis suggested that the reason for these differences related predominantly to differences in the severity of the infection. CONCLUSIONS: Markers of disease severity appear to be the most important predictors of outcome in patients with severe community-acquired pneumonia.

APACHE↗

PubMed1999

The presence and sequence of endotracheal tube colonization in patients undergoing mechanical ventilation.

Endotracheal tube colonization in patients undergoing mechanical ventilation was investigated. In the first part of this prospective study, the airway access tube was examined for the presence of secretions, airway obstruction and bacterial colonization, in cases undergoing extubation or tube change. In the second part of the study, the sequence of oropharyngeal, gastric, respiratory tract and endotracheal tube colonization was investigated by sequential swabbing at each site twice daily for 5 days in consecutive noninfected patients. In the first part, it was noted that all airway access tubes of cases undergoing extubation had secretions lining the interior of the distal third of the tube which were shown on scanning electron microscopy to be a biofilm. Gram-negative micro-organisms were isolated from these secretions in all but three cases. In the second part, it was noted that the sequence of colonization in patients undergoing mechanical ventilation was the oropharynx (36 h), the stomach (3660 h), the lower respiratory tract (60-84 h), and thereafter the endotracheal tube (60-96 h). Nosocomial pneumonia occurred in 13 patients and in eight cases identical organisms were noted in lower respiratory tract secretions and in secretions lining the interior of the endotracheal tube. The endotracheal tube of patients undergoing mechanical ventilation becomes colonized rapidly with micro-organisms commonly associated with nosocomial pneumonia, and which may represent a persistent source of organisms causing such infections.

Adult↗

PubMed1998

Effect of rolipram and dibutyryl cyclic AMP on resequestration of cytosolic calcium in FMLP-activated human neutrophils.

1. We have investigated the effects of the selective phosphodiesterase (PDE) type 4 inhibitor, rolipram (0.01-1 microM) on cytosolic Ca2+ fluxes in FMLP-activated human neutrophils, as well as on superoxide production by, and release of elastase from, these cells. 2. Cytosolic Ca2+ fluxes were measured by use of fura-2 spectrofluorimetry in combination with a radiometric procedure that enables distinction between net efflux and influx of the cation. Superoxide production and elastase release were measured by lucigenin-enhanced chemiluminescence and a colorimetric procedure, respectively. 3. Pretreatment of neutrophils with rolipram did not affect the FMLP-activated release of Ca2+ from intracellular stores, but was associated with dose-related acceleration of the rate of decline in fura-2 fluorescence and with decreased efflux, as well as store-operated influx of 45Ca2+, indicative of enhancement of resequestration of the cation by the endo-membrane Ca2+-ATPase. 4. Inhibition of superoxide production and elastase release was observed at concentrations of rolipram which accelerated the clearance of Ca2+ from the cytosol of FMLP-activated neutrophils. 5. These effects of rolipram on FMLP-activated Ca2+ fluxes, superoxide generation and elastase release were mimicked by pretreatment of neutrophils with dibutyryl cyclic AMP (0.5-4 mM), while theophylline (10-150 microM), a non-specific PDE inhibitor, as well as the beta2-agonist, salbutamol, were less effective. 6. We conclude that rolipram deactivates FMLP-stimulated human neutrophils by enhancement of cyclic AMP-dependent resequestration of cytosolic Ca2+.

Adrenergic beta-Agonists↗

PubMed1997

Calcium efflux and influx in f-met-leu-phe (fMLP)-activated human neutrophils are chronologically distinct events.

The kinetics of efflux of calcium mobilized from intracellular stores following activation of human neutrophils with the synthetic chemotactic tripeptide, fMLP (1 microM), as well as that of the subsequent store-operated influx of this cation, has been measured by radiometric procedures using 45Ca. These procedures enabled distinction between net efflux and influx of 45Ca. Preincubation of neutrophils in medium containing 45Ca as the sole source of Ca2+, followed by activation with fMLP, resulted in a rapid efflux of the cation, which coincided with its release from intracellular stores. Efflux terminated at approximately 30 s after addition of fMLP to neutrophils and resulted in the loss of 42 +/- 3% (P < 0.005) of cell-associated 45Ca. Net influx of 45Ca, which was insensitive to the voltage-dependent Ca2+ channel blockading agent, verapamil (20 microM), could only be detected at 30-60 s after the addition of fMLP to neutrophils, and proceeded for about 5 min, resulting in intracellular concentrations of Ca2+ which were 27 +/- 3% (P<0.05) higher than preactivation levels. These results demonstrate that the efflux of cytoplasmic Ca2+ mobilized from intracellular stores during activation of neutrophils by fMLP, and the subsequent influx of extracellular Ca2+ to replete these stores, are chronologically distinct events in fMLP-activated neutrophils.

Calcium↗

PubMed1996

Cryptococcosis: an unusual cause of endobronchial obstruction.

We report the case of a 43 year old male patient, with normal immune function, who presented with right middle and lower lobe collapse. At bronchoscopy, a white lobulated lesion was seen, completely obstructing the origin of bronchus intermedius. Bronchial washings and biopsy of the lesion demonstrated cryptococcal organisms. The patient responded clinically and radiologically to amphotericin B and flucytosine; however, repeat bronchoscopy revealed only partial resolution of the endobronchial lesion.

Adult↗

PubMed1993

Factors associated with airway colonisation and invasion due to Klebsiella spp.

The clinical significance of a heavy growth of Klebsiella spp. in sputum was studied in 54 patients. All but 3 patients had significant factors potentially associated with respiratory tract colonisation or invasion. Risk factors identified for colonisation of the airway and for invasive disease were similar. Patients with community-acquired Klebsiella infections were more likely to have underlying chronic respiratory diseases. Prior antibiotic use was a risk factor for nosocomial infections which occurred more commonly with antibiotic-resistant organisms. The most common diagnoses were airway colonisation, acute community-acquired chest infections, and nosocomial chest infections. Primary acute community-acquired pneumonia was uncommon. The sensitivity and specificity of the sputum Gram stain (in the setting of positive sputum cultures) in suggesting the presence of invasive disease due to Klebsiella spp. were 42% and 69% respectively.

Adolescent↗

PubMed1992

Does primary Streptococcus viridans pneumonia exist?

In 4 adult black patients admitted to an urban general hospital with community-acquired pneumonia, Streptococcus viridans alone was isolated from blood culture (first subculture), in the absence of any other positive microbiological finding. Sputum examination by Gram staining and culture in 3 cases was reported as negative. Echocardiography was performed in 3 cases and was normal, without evidence of endocarditis. The clinical course of illness in the 4 patients is described. The chest radiograph showed a segmental or subsegmental consolidation in all cases; this appeared 'mass-like' in 2 patients. Viridans streptococci may be a more important, if still uncommon, cause of community-acquired pneumonia than previously suspected. The organism should be considered as a possible cause of chest infection, particularly in patients with appropriately positive blood cultures and no other positive microbiological finding.

Adult↗