Evaluation of enzyme-linked immunosorbent assay [ELISA] in serodiagnosis of pulmonary tuberculosis

A total of 45 patients with pulmonary tuberculosis and 45 healthy individuals were subjected to chest examination, radiography and ELISA tests for IgA and IgG antibodies. Sputum smear and culture were performed for all tuberculous patients. Evaluated against clinical and radiological diagnosis, ELISA's specificity exceeded 90% in detecting specific IgA and IgG antibodies. The parallel application of ELISA and microscopic examination of sputum yielded 80% sensitivity compared with clinical and radiological examination and 100% sensitivity compared with culture. ELISA alone can be used in ruling out pulmonary tuberculosis but not in diagnosing the disease. However, coupled with microscopic examination, it can be used instead of culture to provide positive diagnosis within 24 hours

Respiratory muscle dysfunction in schistosomal cor pulmonale: physiological histopathological and immunohistochemical studies

The study was conducted on 18 patients with schistosomal cor pulmonale with mean pulmonary artery pressure of 52.6 +/- 21.2 mm Hg, pulmonary vascular resistance of 8.1 +/- 4.7 unit and cardiac index of 3.03 +/- 0.37 L/min/m2. This work aimed to evaluate respiratory and diaphragmatic muscle strength and its impact on breathing pattern alteration. Histopathological and immunohistochemical studies were also performed on ten patients with evident reduced respiratory muscle strength to assess the structural changes and to identify the possible etiological mechanism for respiratory muscle dysfunction. Schistosomal cor pulmonale patients demonstrated reduction in respiratory muscle strength with mean values of 68.6 +/- 9.1% pred and 70.1 +/- 10.2% pred for maximal inspiratory and expiratory pressures respectively. On the other hand, transdiaphragmatic pressure during both normal and maximal effort showed mean values within the normal range [34.7 +/- 6.2 and 181.2 +/- 43.7cm H2O respectively]. Yet; diaphragmatic endurance index in the term of tension time index was found to be [0.09 +/- 0.05] reflecting reduction in diaphragmatic endurance. Breathing pattern demonstrated significant [P<0.01] increment in minute ventilation [VE: 13.5 +/- 1.6 L/min] respiratory frequency [F: 25.2 +/- 2.7] and mean inspiratory flow [V[t] /T[i]; 570.5 +/- 95.8]; whereas; inspiratory duty cycle was significantly [P<0.01] reduced [T[i]T[tot]: 0.4 +/- 0.03] in comparison to control. PE[max] and PI[max] showed significant [P<0.05] negative correlation with V[T] /T[i] [r=-0.69,r =-0.88] and significant [P<0.05] positive correlation with T[i]T[tot] [r = 0.78 and r = 6.85] suggesting that respiratory muscle dysfunction does contribute to breathing pattern alterations. Histopathological study revealed myopathic changes in the form of increased variation in fiber diameter, degenerative changes with increased eosinophilic staining in 6 cases, fiber splitting and fragmentation in 7 cases and endomysial fatty changes in 5 patients Immunohistochemical study using anti-IgG and IgM antibodies revealed positive cytoplasmic staining for IgG in all cases and for IgM in 6 cases while none of the control showed positive stiaining. These previously unreported data document that patients with schistosomal cor pulmonale suffer from respiratory muscle affection at both physiological and histopathological levels. Immunohistochemical findings suggest immunopathogenetic mechanism for their deranged function. Greater attention should be paid for respiratory muscle while evaluating the respiratory functional state of patients with schistosomal cor pulmonale

Breathing pattern, respiratory center activity respiratory muscle function in schistosomal cor pulmonale: Relation to pulmonary hemodynamics

Breathing pattern, respiratory activity and respiratory muscle function were studied in 25 patients with schistosomal cor pulmonale, with mean pulmonary artery pressure [MPAP] of 47.4 +/- 21.2 mmHg, cardiac index 3.2 +/- 0.5 L/min/m2 and pulmonary vascular resistance [PVR] 7.4 +/- 4.4 units. The pattern of breathing showed near normal tidal volume, increased respiratory frequency, minute ventilation, mean inspiratory flow and decreased inspiratory duty cycle. Respiratory center activity, as measured by the mouth occlusion pressure P 0.1, was increased and demonstrated significant positive correlation with the mean pulmonary artery pressure. Data of the present study also revealed that schistosomal cor pulmonale patients have respiratory muscle weakness as evidenced by a reduction in the maximal inspiratory and expiratory pressure, while diaphragmatic function was found to be preserved. The respiratory muscle strength [PI max and PE max] revealed strong negative correlation with MPAP and PVR. Inclusion schistosomal cor pulmonary patients exhibit disturbed breathing pattern and respiratory muscle performance. The study of these parameters should be included in evaluating ventilatory function in such patients, since it reflects changes in pulmonary hemodynamics

Evaluation of angiotensin converting enzyme activity and hemodynamic effects of angiotensin converting enzyme inhibitor in bilharzial cor pulmonale

Serum angiotensin converting enzyme [ACE] activity as well as systemic and pulmonary hemodynamic parameters were evaluated in 15 patients with bilharzial cor pulmonale through right sided cardiac catheter before and 60 minutes after oral administration of 50 mg of angiotensin converting enzyme inhibitor [ACEI] captopril. Following long term treatment with ACEI at a daily dose of 50 mg for 3 weeks, the same parameters were re-evaluated. Angiotensin enzyme activity was found to be significantly high [P <0.01] relative to control before initial dose treatment and demonstrated significant reduction [P <0.01] in activity following ACEI treatment. This reduction in activity coincided with the improvement in hemodynamics. Following 60 minutes of ACEI administration, significant reduction [P <0.01] in mean pulmonary artery pressure [MPAP], pulmonary capillary wedge pressure PCWD [P <0.01], pulmonary vascular resistance PVR [P <0.01] and right ventricular stroke work index RVSWI [P <0.01] were noted. Significant decreases in mean systemic blood pressure SBP [P <0.01], systemic vascular resistance SVR [P <0.01] and left ventricular stroke work index LVSWI [P <0.01] were also recorded. Cardiac index CI showed insignificant change. Hemodynamic effects of long term treatment of ACEI at daily dose of 50 mg revealed less but still significant changes similar to the acute hemodynamic effects. These results suggested that ACE plays a role in pulmonary hypertension in patients with bilharzial cor pulmonale and hence ACEI may be beneficial in reducing its severity

Respiratory muscle performance in chronic obstructive lung diseases and interstitial lung fibrosis

Respiratory muscle performance and breathing pattern were studied in 10 patients with chronic obstructive pulmonary disease [COPD] and 12 patients with interstitial pulmonary fibrosis [IPF]. Data of the present study revealed that patients with COPD had respiratory muscle weakness and diminished endurance as evidenced by decrease in maximal expiratory pressures [PE max=42% pred., PI max.=53% pred.] and the critical value of the tension time index of the diaphragm [TIdi=0.12]. The pattern of breathing in COPD showed an increase in tidal volume [TV=617 ml], respiratory frequency [F=22/m], minute ventilation [VE=12.8 L/m], and the mean inspiratory flow [VT/Ti=606 ml/sec], while there was a decrease in the inspiratory duty cycle [Ti/Ttot=0.37]. Patients with IPF had also respiratory muscle weakness as manifested by decreased PE max [49% pred.] and PI max [68% pred.], while endurance was not much affected [TIdi=0.1]. Breathing pattern in IPF showed decrease in TV [478 ml], and increase in F [36/m], VE [16 L/m], and VT/Ti [669 ml/sec], while Ti/Ttot was within normal [0.42]. It was concluded that respiratory muscle dysfunction and abnormal breathing pattern are important features in COPD and IPF and therefore should be included in the clinical and physiological evaluation of these patients

Peripheral neurological changes in chronic obstructive pulmonary diseases: Clinical and electrophysiological studies

Twenty five patients with COPD with mean age of 55.4 +/- 8.7 years have been investigated with pulmonary function tests [PFT], arterial blood gases [ABG], serum electrolytes [Na, K, Ca++], neurological examination and electrophysiological studies. Symptoms of neuropathy were present in 36% of the patients, while clinical signs were found only in 20%. Orthodromic distal sensory latency was prolonged in 44% of cases with lowering of amplitude of the evoked sensory action potential. Abnormalities of the sensory nerve conduction were the most common and affecting mainly the sural nerve. Motor conduction velocity was abnormal in 16% of cases. Sixteen percent of COPD patients exhibited impairment of both sensory and motor functions. Abnormal electromyographic [EMG] findings were detected in 11 cases [44%]. The EMG changes were abnormal resting potential, incomplete interference pattern and polyphase motor unit. These denoted the existence of both myelinopathic and axonopathic changes. Comparative study of COPD patients with neurological impairment [group I] versus COPD patients without such defect [group II] regarding PFT, ABG and serum electrolytes revealed insignificant difference in PFT and serum electrolytes between both groups. However, patients of group I were more hypoxemic and hypercapnic than group II patients and the difference in PaO2 and PaCO2 were statistically significant [P <0.01]. It was concluded that peripheral neuropathy is not uncommon finding in COPD and it seems possible that severe derangement in ABG in form of hypoxemia and hypercapnia are responsible for the encountered neurological abnormalities