Contact tracing/pre-employment screening for pulmonary tuberculosis: should positive Mantoux test necessitates routine chest X-ray?

BACKGROUND: Pulmonary tuberculosis (PTB) remains a scourge in most developing countries. Mantoux skin test and more commonly chest radiography are some of the methods of diagnosing the disease, especially with regard to contact tracing and pre-employment screening. Regular use of radiography has both safety and cost implications. This study aimed at establishing if any justification exists in requesting for chest radiographs in asymptomatic subjects with a positive Mantoux skin test reaction. METHODS: 174 adults comprising PTB contacts and newly employed/admitted university staff/students were recruited into the study. They were 89 males (51.1%) and 85 females (48.9%). All subjects had Mantoux test (using purified protein derivative, PPD). Patients who had positive Mantoux reaction subsequently were subjected to posteroanterior chest radiographic examination. Mantoux test and chest radiographic findings were then correlated with each other. RESULTS: 102 subjects (59.2%) had positive Mantoux reactions, while 27 subjects (31.1%) had abnormal chest radiographs. There was no significant correlation between Mantoux readings and chest radiographic findings (P=0.106). CONCLUSION: It is concluded that other ancillary tests like sputum examination and/or, where available, Interferon and ESAT tests should be carried out before chest radiograph is requested in subjects with positive Mantoux reaction.

Potential hazard of the Neopuff T-piece resuscitator in the absence of flow limitation.

OBJECTIVE: (1) To assess peak inspiratory pressure (PIP), positive end expiratory pressure (PEEP) and maximum pressure relief (P(max)) at different rates of gas flow, when the Neopuff had been set to function at 5 l/min. (2) To assess maximum PIP and PEEP at a flow rate of 10 l/min with a simulated air leak of 50%. DESIGN: 5 Neopuffs were set to a PIP of 20, PEEP of 5 and P(max) of 30 cm H(2)O at a gas flow of 5 l/min. PIP, PEEP and P(max) were recorded at flow rates of 10, 15 l/min and maximum flow. Maximum achievable pressures at 10 l/min gas flow, with a 50% air leak, were measured. RESULTS: At gas flow of 15 l/min, mean PEEP increased to 20 (95% CI 20 to 21), PIP to 28 (95% CI 28 to 29) and the P(max) to 40 cm H(2)O (95% CI 38 to 42). At maximum flow (85 l/min) a PEEP of 71 (95% CI 51 to 91) and PIP of 92 cm H(2)O (95% CI 69 to 115) were generated. At 10 l/min flow, with an air leak of 50%, the maximum PEEP and PIP were 21 (95% CI 19 to 23) and 69 cm H(2)O (95% CI 66 to 71). CONCLUSIONS: The maximum pressure relief valve is overridden by increasing the rate of gas flow and potentially harmful PIP and PEEP can be generated. Even in the presence of a 50% gas leak, more than adequate pressures can be provided at 10 l/min gas flow. We recommend the limitation of gas flow to a rate of 10 l/min as an added safety mechanism for this device.

Phytochemical and microscopic evaluation of cultivated Datura innoxia miller.

Using a sensitive analytical method, the total alkaloid content of Datura innoxia cultivated in Ibadan is reported at different stages of growth. Furthermore, the total hyoscine content of D. inoxia has been shown to peak during the harmattan season and to be at its lowest in the rainy season in Ibadan. The diagnostic microscopic features of this little studied species is also described.

The bony callus.

The bony callus was investigated by staining with the PAS and von Gieson techniques. The callus appeared to be composed of two adjoining but distinct types of bone. The birefringence observed in the periosteum and callus cartilage revealed different sized collagen fibres, each oriented perpendicularly to the long axis of the diaphysis.