Antimicrobial and antispasmodic activity of leaf extract and fractions of Stachytarpheta cayennensis

ObjectiveTo investigate the antimicrobial activity of the methanol leaf extract (ME), n-hexane fraction (HF), ethylacetate fraction (EF) and methanol fraction (MF), of Stachytarpheta cayennensis C. Rich (verbenaceae) as well as to ascertain the antispasmodic effects of the ME and the various fractions (HF, EF and MF) on acetylcholine (Ach) and histamine (H) induced contractions on isolated guinea pig ileum.MethodsThe in vitro agar well diffusion method was used for the antimicrobial studies while the isolated tissue method was employed for the antispasmodic test. Organisms used were all clinical isolates of Bacillus subtilis, Staphylococcus aureus, Pseudomonas aeruginosa, Salmonella paratyphi, Candida albicans and Aspergillus niger.ResultsThe extract and fractions exhibited dose dependent inhibition against all the bacteria tested and also exhibited insignificant antifungal activity against Candida albicans and Aspergillus niger. The minimum inhibitory concentration (MIC) of the extract and fractions (mg/mL) on Bacillus subtilis, Staphylococcus aureus, Pseudomonas aeruginosa and Salmonella paratyphi respectively were ME 5.62, 14.12, 22.38, 2.11; EF 1.25, 6.30, 9.40, 9.40 and MF 3.98, 8.81, 39.80, 21.13. The n-hexane fraction exhibited MIC of 1.07 mg/mL against only Bacillus subtilis. The extract and fractions exhibited significant (P< 0.05) dose dependent attenuation of contractions induced by acetylcholine and histamine on isolated guinea pig ileum. Concentrations of the extract and fractions (μg/mL) which evoked 50% inhibition of maximal response exhibited by Ach were ME 0.64, HF 0.16, EF 0.08 and MF 0.15, while that of histamine included ME 5.12, HF 0.16, EF 0.04 and MF 0.64. Preliminary phytochemical studies on the extract and fractions indicated the presence of carbohydrates, alkaloids, saponins, flavonoids, steroids and terpenoids.ConclusionsThe extract and fractions of Stachytarpheta cayennensis possessed both antibacterial and antispasmodic effects confirming the claimed use in folkloric medicine for wound healing and gastrointestinal ulceration.     

Risk of high‐level viraemia in HIV‐infected patients on successful antiretroviral treatment for more than 6 months

Objectives

According to the Swiss Federal Commission for HIV/AIDS, HIV‐infected patients on successful antiretroviral treatment have a negligible risk of transmitting HIV sexually. We estimated the risk that patients considered to have an undetectable viral load (VL) are actually viraemic.

Methods

A Danish, population‐based nationwide cohort study of HIV‐infected patients with VL <51 HIV‐1 RNA copies/mL for more than 6 months was carried out for the study period 2000–2008. The observation time was calculated from 6 months after the first VL <51 copies/mL to the last measurement of VL or the first VL >50 copies/mL. The time at risk of transmitting HIV sexually was calculated as 50% of the time from the last VL <51 copies/mL to the subsequent VL if it was >1000 copies/mL. The outcome was the time at risk of transmitting HIV sexually divided by the observation time.

Results

We identified 2680 study subjects contributing 9347.7 years of observation time and 56.4 years of risk of transmitting HIV (VL>1000 copies/mL). In 0.6% [95% confidence interval (CI) 0.5–0.8%] of the overall observation time the patients had VL >1000 copies/mL. In the first 6 months this risk was substantially higher (7.9%; 95% CI 4.5–11.0%), but thereafter decreased and was almost negligible after 5 years (0.03%; 95% CI 0.0–0.2%). The risk was higher in injecting drug users, but otherwise did not differ between subgroups of patients.

Conclusion

The risk of viraemia and therefore the risk of transmitting HIV sexually are high in the first 12 months of successful antiretroviral treatment, but thereafter are low.     

Anomalous coronary arteries originating in the contralateral sinus of Valsalva: registry of thirteen Spanish hospitals (RACES)

The registry contains information collected during 2003 from thirteen Spanish hospitals on the incidence, clinical presentation, initial course, diagnostic imaging, and treatment of anomalous coronary arteries originating in the contralateral coronary sinus. In a total of 23,300 coronary angiograms, 98 anomalous coronary arteries were detected (incidence 0.4%): 46 circumflex coronary arteries (47%), 25 right coronary arteries (25.5%), 10 left main coronary arteries (10.2%), three left anterior descending arteries (3.1%), six single coronary arteries (6.1%), and eight other anomalies (8.2%). The most frequent indication for angiography was angina (43.9%). The initial course of the anomalous coronary artery was not identified in 40.8% of cases. In two patients (2%), diagnostic imaging was used to identify the initial course. Associated atherosclerotic disease was present in 51% of patients. In addition, 18.4% had associated valvular disease, with the aortic valve being affected most often (15.2%). Some 16.3% of patients underwent treatment for the coronary anomaly. The incidence was similar to that observed in other published series, with anomalies in the circumflex coronary artery being diagnosed most frequently. Diagnostic imaging was underused.     

Frequency measurements in real-time US equipment: variations from expected values

The frequency responses of nine real-time mechanical probes and two pulsed Doppler probes from four manufacturers were measured. The reflected frequency was measured in a clinical environment by evaluating the pulser, transducer assembly, and receiver as a system. Two independent systems were used for these measurements: a spectrum analyzer and a data acquisition system that computed the fast Fourier transform of the reflected waveform. Results showed that probe frequency (calibrated by the manufacturer in the transmit mode with a hydrophone) was as much as 30% higher than that found by means of frequency measurement procedures with the probe attached to the ultrasound system and evaluated in the receive mode. Such large discrepancies indicate that if acceptance testing of the frequency spectrum is not performed at a clinical facility, prolonged clinical evaluation of new equipment should be arranged.     

Air-borne disease

Respiratory protection is a factor which worries nursing professionals who take care of patients susceptible of transmitting microorganisms through the air more as every day passes. This type of protection covers the use of surgical or hygienic masks against the transmission of infection by airborne drops to the use of highly effective masks or respirators against the transmission of airborne diseases such as tuberculosis or SARS, a recently discovered disease. The adequate choice of this protective device and its correct use are fundamental in order to have an effective protection for exposed personnel. The authors summarize the main protective respiratory devices used by health workers, their characteristics and degree of effectiveness, as well as the circumstances under which each device is indicated for use.