Clinical utility of PCR assay of a target Sequence on the the 31 - kilodalton brucella antigen DNA in human brucellosis

Human brucellosis poses a significant public health problem in many developing countries and requires fast and accurate diagnosis. The diagnosis of brucellosis is frequently difficult to establish, not only because clinically, the disease may mimic other infectious and non infectious disease, but also because the established diagnostic methods are not always successful. In order to overcome some of the limitations of the conventional microbiological techniques in the diagnosis of human brucellosis, a PCR-Enzyme Linked Immunosorbent Assay [PCR-ELISA] with genus-specific primers was developed for the amplification of a 223-bp sequence of a gene encoding for the synthesis of a 31-KDa immunogenic membrane protein specific for the Brucella genus [BCSP31], with a detection limit of 10 f g bacterial DNA [2 bacterial cells] for the rapid diagnosis of human brucellosis. In this study, we collected peripheral blood samples from 80 patients with active brucellosis diagnosed on the basis compatible clinical picture with positive blood culture and/or positive serology; and also from control subjects composed of 25 volunteer blood donors, 14 patients with febrile illness due to factors other than Brucella etiology, and 11 asymptomatic occupationally exposed persons. The diagnostic yield of PCR-ELISA assay in human Brucellosis was evaluated by comparing its results in the patient and control groups with those of the conventional microbiological techniques such as serology, using the Standard Tube Brucella Agglutination Test [SAT], and blood cultures for Brucella using the semiautomatic Bactec 9240 system. Out of the 80 patients with active brucellosis, 37 [46.25%] were blood culture positive for Brucella, and 78 [97.5%] were serology positive. All of these 80 cases were PCR-ELISA was 100% followed by 97.5% of serology and 46.25% of blood culture. Five cases among the patient group showed focal [localized] manifestations, three of them presented with chest manifestations or disease and two with osteoarthyitis, diagnosis of these cases was established on the basis of clinical and serological critia and confirmed by PCR-ELISA assay. All of the 50 control blood samples were blood culture negative. While, 2 samples from the occupationally exposed group showed high titer specific brucella antibodies >/-160. PCR-ELISA was able to detect 3 positive cases in the control group, all of them were also from the occupationally exposed asymptomatic group. Thus, the specificity of blood culture was 100% followed by 96% of serology and 94% of PCR-ELISA. The corrected specificity of the PCR-ELISA and serology after exclusion of the occupationally exposed asymptomatic group was 100%. We concluded that PCR assay is far more sensitive than the conventiomal techniques and this, coupled with its speed and reduction in risk to laboratory workers, makes this technique a very useful practical tool for the laboratory diagnosis of human brucellosis

Renin-angiotensin II -aldosterone axis disturbances in patients with chronic obstructive pulmonary disease

To study the possible disturbances of renin-angiotensin II Aldosterone system [RAAS] in chronic obstructive pulmonary disease [COPD] patients, this work was conducted. It included 45 COPD and 10 healthy control volunteers. Both plasma renin activity [PRA] and plasma aldosterone [PA] were measured in patients and controls by radioimmunoassay [RIA] and the results were plotted against clinical and functional data as well as serum and urinary electrolytes. In COPD patients, PRA and PA levels [means +/- SD were 4.4 +/- 1.16 ng/ml/h and 132 +/- 44pg/ml us 1.2 +/- 0.26 ng/ml/h. and 65 +/- 3pg/ml respectively, were significantly higher than those of controls, and positively correlated with each other. There was no effect of sex, body weight or age on the RAAS, while a significant positive correlation between smoking and PRA was found. Greater RAAS stimulation was observed in the presence of peripheral edema and with advancement of hypercapnia, hypoxemia and airway obstruction. Inability to excrete sodium, in urine was the most prominent electrolyte disturbance in advanced COPD. Mechanical ventilation was associated with further stimulation of RAAS. In conclusion, RAAS is frequently stimulated in COPD patients especially in advanced stages of the disease, leading to a state of secondary hyperaldosteronism of the hyperreninemic type that may contribute to sodium retention and edema formation. Hypercapnia and, to lesser degree, hypoxemia may be the most accused predisposing factors for RAAS stimulation

Effects of occupational exposure to lead on neurological and neurophsyiological functions among printing workers

This study was designed to evaluate the neurological and the neurohysiological effects of chronic lead exposure. A group of printing workers exposed to inhalation, ingestion and skin absorption of lead, consisting of 47 subjects, as well as a control group from the non-exposed administrative subjects were included. This study was designed to evaluate the neurological and the neurophysiological effects of chromic lead exposure. A group of printing workers exposed to inhalation, ingestion and skin absorption of lead, consisting of 47 subjects, as well as a control group from the nonexposed administrative subjects were included. All subjects were submitted to assessment of exposure profile, general and neurological history and examination, blood lead concentration, blood picture, and a selected battery of neurophysiological investigations. Among exposed workers compared to controls, we detected a significantly higher prevalence 9% headache, fatigability, muscle weakness, numbness and tingling sensations and significantly higher blood lead levels and lower hemoglobin levels. The electro physiological studies showed significant motor and sensory slowing of nerve conduction velocities [NCVs], lowering of amplitudes, and prolongation of distal latencies both median and ulnar nerves of the exposed workers versus control subjects. Abnormalities of electromyograpnhy [EMG] in the form of neurogenic polyphasic waves during ' minimal muscle contraction and spontaneous activities were recorded in 91.7% and 16.7% respectively among exposed workers