Effects of five earthworm species on some physico-chemical properties of soil.

An incubation experiment was conducted to study the changes that occur in organic carbon content, phosphorous and potassium availability and other soil properties with ingestion of soil mixed with rubber leaf litter and cow dung by five earthworm species viz. Pontoscolex corethrurus, Drawida assamensis, Drawida papillifer papillifer, Eutyphoeus comillahnus and Metaphire houlleti of rubber plantation in Tripura (India). Due to earthworm activity organic C (1.56-1.63%) and available P (14.71-27.60 mg 100 g-1) and K (43.50-49.0 mg 100 g-1) content of the soil increased significantly (p<0.05) in most of the earthworm species studied. M. houlleti and D. papillifer papillifer had the highest P (27.60 mg 100 g-1) and K (49.0 mg 100 g-1) mobilization capacity, respectively. Earthworms, irrespective of the species, increased the pH (7.05-7.17) and electrical conductivity (663-1383 µS cm-1) of the soil significantly (p<0.05).

A study to determine the pharmacokinetics of gatifloxacin following a single oral dose.

Gatifloxacin is a broad spectrum fluoroquinolone that offers enhanced Gram-positive activity and anaerobic coverage to other fluoroquinolones. The pharmacokinetic parameters (Cmax, AUCo-t, tmax) of this drug have been evaluated to compare the single dose (400mg) bioavailability of gatifloxacin with the reference formulation. High performance liquid chromatography (HPLC) coupled with U-V detector set at 290 nm has been used to determine plasma concentration of 12 human volunteers as per DCGI (Drug Controller General of India) guidelines. The method has been validated over a linear range of 0.25 to 8 microg/ml from plasma. The minimum quantifiable concentration has been set at 0.25 microg/ml (% CV < 10%). The pharmacokinetic parameters are: Cmax = 4.366 +/- 0.44 microg/ml at tmax = 1.83 +/- 0.44 hour, AUCO0-t = 25.26 +/- 2.91 microg hour/ml, AUCo-inf = 33.68 +/- 4.31 microg hour/ml, Kel = 0.094 +/- 0.024/hour and t1/2 = 8.0 +/- 1.92 hour.

Bioequivalence study of rabeprazole sodium on healthy human volunteers.

The newly developed proton pump inhibitor rabeprazole sodium is expected to have beneficial effects in the treatment of peptic ulcer. The pharmacokinetic parameters (C(max), AUC(o-t), t(max)) of this drug have been evaluated to compare the single dose (20 mg) bioavailability of rabeprazole sodium with the standard reference. High performance liquid chromatography (HPLC) coupled with UV detector set at 280 nm has been used to determine plasma concentration of 12 human volunteers as per Drugs Controller General of India (DCGI) guidelines. The method has been validated over a linear range of 20-480 ng/ml from plasma. The minimum quantifiable concentration was set at 10 ng/ml [co-efficient of variance (CV) < 10%]. By comparing AUC(o-t) the relative bioavailability of test preparation has been found to be 100.88% of that of reference preparation.

High performance liquid chromatographic determination of cox-2 inhibitor rofecoxib in human plasma.

A convenient, sensitive and simple method for the determination of rofecoxib in human plasma is presented. The analytical technique is based on reversed phase high performance liquid chromatography coupled with UV detector (Knauer, Germany) set at 272 nm. The retention time of rofecoxib after recovery from plasma, was 8.9 minutes. The method has been validated over a linear range of 50-450 ng/ml from plasma. After validation the method was used to study the pharmacokinetic profile of rofecoxib in 6 healthy volunteers as per DCGI guidelines after administration of a single oral dose (50 mg). The extraction efficiency from plasma varied from 93.95-99.58%. The minimum quantifiable concentration was set at 50 ng/ml (% CV < 10%). The pharmacokinetic parameters were Cmax = 318.58 +/- 30.65 ng/ml at tmax = 2.66 +/- 0.25 hours, AUC0-t = 4007.88 +/- 438.32 ng hour/ml, AUC0-yen = 5454.66 +/- 822.29 ng hour/ml, Kel = 0.0433 +/- 0.0067/hour, and t1/2 = 16.36 +/- 2.89 hours.

Some prospective observations on recent outbreak of typhoid fever in West Bengal.

The present study was designed to study the clinical behaviour of a recent epidemic of typhoid fever in West Bengal. Of 46 cases studied, 67% (31) had chloramphenicol resistant typhoid fever. The chloramphenicol-resistant cases were comparatively severe in nature with higher complication and mortality rates. Salmonella typhi resistant to chloramphenicol were also resistant to ampicillin, cloxaxillin and cotrimoxazole. Strains of Salmonella typhi sensitive to chloramphenicol retained their sensitivity to these other antimicrobials.