Effect of Multi Drug Resistance Protein 4 (MRP4) Inhibition on the Pharmacokinetics and Pharmacodynamics of Ciprofloxacin in Normal and Rats with LPS-Induced Inflammation

BACKGROUND AND OBJECTIVES

Infection and inflammation are known to cause wide variability in disposition of drugs through modulation of drug transporters. However, the effects of inhibition of multidrug resistance protein 4 (MRP4) on pharmacokinetics and pharmacodynamics are poorly understood in normal and inflamed conditions. We hypothesized that inflammation alters the pharmacokinetic parameters of ciprofloxacin; and Pharmacokinetic/Pharmacodynamic indices, such as ratio of peak plasma concentration to minimum inhibitory concentration (C _max/MIC) and ratio of area under the plasma drug concentration-time curve to minimum inhibitory concentration (AUC/MIC) of ciprofloxacin will be improved with the co-administration of a MRP4 inhibitor, dipyridamole, in inflammatory conditions.

METHODS

In this study, the role of MRP4 on the pharmacokinetic and pharmacodynamic parameters of ciprofloxacin was investigated by the co-administration of dipyridamole in rats with or without lipopolysaccharide (LPS)-induced inflammation. The pharmacokinetic parameters for ciprofloxacin were calculated by non-compartmental approach. MIC of ciprofloxacin was determined using broth microdilution technique.

RESULTS

Induction of inflammation in rats resulted in marked reduction in C _max and AUC; and an increase in the volume of distribution (V _d/F) and clearance (Cl/F) of ciprofloxacin, compared to normal rats. Co-administration of dipyridamole with ciprofloxacin in inflamed rats resulted in a threefold increase in AUC, a twofold decrease in V _d/F and a threefold decrease in Cl/F of ciprofloxacin with significantly prolonged half-life compared to inflamed rats who received ciprofloxacin alone. Co-administration of dipyridamole enhanced AUC/MIC values of ciprofloxacin in both normal and inflamed rats.

CONCLUSIONS

The results suggest that MRP4 inhibition increases the systemic exposure of ciprofloxacin in both normal and inflammatory conditions.

Adsorption mechanism of graphene-like ZnO monolayer towards CO₂ molecules: enhanced CO₂ capture

This work aims to efficiently capture CO2 on two-dimensional (2D) nanostructures for effective cleaning of our atmosphere and purification of exhausts coming from fuel engines. Here, we have performed extensive first principles calculations based on density functional theory (DFT) to investigate the interaction of CO2 on a recently synthesized ZnO monolayer (ZnO-ML) in its pure, defected and functionalized form. A series of rigorous calculations yielded the most preferential binding configurations of the CO2 gas molecule on a ZnO-ML. It is observed that the substitution of one oxygen atom with boron, carbon and nitrogen on the ZnO monolayer resulted into enhanced CO2 adsorption. Our calculations show an enriched adsorption of CO2 on the ZnO-ML when substituting with foreign atoms like B, C and N. The improved adsorption energy of CO2 on ZnO suggests the ZnO-ML could be a promising candidate for future CO2 capture.

Hydrogen storage properties of light metal adatoms (Li, Na) decorated fluorographene monolayer

Owing to its high energy density, the potential of hydrogen (H2) as an energy carrier has been immense, however its storage remains a big obstacle and calls for an efficient storage medium. By means of density functional theory (DFT) in spin polarized generalized gradient approximation (GGA), we have investigated the structural, electronic and hydrogen storage properties of a light alkali metal (Li, Na) functionalized fluorographene monolayer (FG). Metal adatoms bind to the FG with significantly high binding energy, much higher than their cohesive energies, which helps to achieve a uniform distribution of metal adatoms on the monolayer and consequently ensure reversibility. Due to a difference of electronegativities, each metal adatom transfers a substantial amount of its charge to the FG monolayer and attains a partial positive state, which facilitates the adsorption of multiple H2 molecules around the adatoms by electrostatic as well as van der Waals interactions. To get a better description of H2 adsorption energies with metal-doped systems, we have also performed calculations using van der Waals corrections. For both the functionalized systems, the results indicate a reasonably high H2 storage capacity with H2 adsorption energies falling into the range for the practical applications.

Pharmacokinetic interaction of curcumin and glibenclamide in diabetic rats

Aim:

The aim was to assess the pharmacokinetic (PK) interaction of curcumin and glibenclamide (GL) in diabetic rats.

Materials and Methods:

Sprague-Dawley rats induced with diabetes were divided into 2 groups of six rats in each. Group I: GL (6 mg/kg po once daily) treatment in diabetic rats and group 2: Curcumin (50 mg/Kg po once daily) + GL (dose as above) in diabetic rats. Blood samples were collected at pre-determined time intervals for kinetic analysis after the first and last oral dosing of GL for single and multiple dose studies, respectively. Plasma samples were assayed for GL concentration by high-performance liquid chromatography and PK parameters were analyzed.

Results:

The half-life (t_1/2) and mean residence time (MRT) of GL were significantly increased in curcumin pre-treated rats as compared to GL alone in single and multiple dose studies. Similarly, the V_dss was significantly increased in curcumin pre-treated rats in single dose study as compared to GL alone treated group, but no significant difference was observed in multiple dose kinetics.

Conclusion:

The study revealed higher values (t_1/2, MRT and V_dss) of GL in curcumin pre-treated group due to the inhibitory effect of curcumin on intestinal CYP3A4.

Protective effect of Lactobacillus plantarum 21, a probiotic on trinitrobenzenesulfonic acid-induced ulcerative colitis in rats

Inflammatory mediators play a crucial role in ulcerative colitis (UC). The present study was aimed to evaluate the effects of Lactobacillus plantarum 21 (LAB 21) on inflammatory mediators in trinitrobenzenesulfonic acid (TNBS)-induced colitis in rats. The inflammatory response was assessed by changes in colon morphology, histopathology, and measurement of reduced glutathione (GSH), lipid peroxidation (TBARS), nitric oxide (NO), interleukin 1β (IL-1β), tumor necrosis factor α (TNF-α), and interleukin 10 (IL-10) mRNA and protein levels by ELISA. Besides, protein expressions of IL-1β and IL-10 were also evaluated by western blot. Treatment with LAB 21 (1×10(10)CFU/rat/day) and sulfasalazine (500mgkg(-1) body weight) for 14days after induction of colitis, significantly decreased TBARS, NO and increased GSH concentration. The protein and mRNA expressions of IL-1β and TNFα were down-regulated, whereas, protein and mRNA expression of IL-10 was up-regulated in LAB 21-treated rats. Moreover, LAB 21 attenuated the macroscopic colonic damage, histopathological changes induced by TNBS. These results suggest that LAB 21 may be effective in the treatment of UC by immunomodulatory and antioxidant properties.

Turpentine oil induced inflammation decreases absorption and increases distribution of phenacetin without altering its elimination process in rats

Plasma concentrations and pharmacokinetics of phenacetin, a CYP1A2 substrate were determined in normal and experimentally induced inflamed rats by turpentine oil to know the role of inflammation on the pharmacokinetics of phenacetin and formation of its active metabolite (paracetamol) by CYP1A2 in wistar albino rats, weighing about 200-250 g that were randomly divided into two groups consisting six in each group. Rats in group I (control) received phenacetin (150 mg kg(-1), PO) where as group II received phenacetin 12 h after induction of inflammation by turpentine oil (0.4 mL, i.m). Blood samples were collected from retro orbital plexus at pre-determined time intervals prior to and at 0.166, 0.33, 0.67, 1.5, 2, 4, 8 and 12 h post-administration of phenacetin. Plasma was separated and analyzed for phenacetin and its metabolite paracetamol by HPLC assay. Based on plasma concentrations of phenacetin and its metabolite paracetamol, the pharmacokinetic parameters were determined by compartmental methods. C(max) of phenacetin was significantly (p < 0.01) decreased to 19.50 ± 2.74 μg mL(-1) in inflamed conditions compared to 38.13 ± 2.20 μg mL(-1) obtained in normal rats. Except, for significant (p < 0.001) increase in volume of distribution at steady state (V(dss)) from 2.87 ± 0.37 to 8.03 ± 1.26 L kg(-1) and increased the rate of absorption with shorter absorption half-life (t(1/2ka)) for phenacetin in inflammation. None of the pharmacokinetic parameters of either phenacetin or its metabolite paracetamol were affected. It can be concluded that turpentine oil induced inflammation has no role on the activity of CYP1A2 in rats, as the plasma concentrations and pharmacokinetic parameters of paracetamol were found unaltered.

Organ-preserving surgery for penile cancer: description of techniques and surgical outcomes

Study Type--Therapy (case series) Level of Evidence 4. What's known on the subject? and What does the study add? Organ-preserving surgeries for penile cancer have been described to reduce the morbidity associated with traditional operations. Patients derive better functional outcomes from penile-preserving surgery, although local recurrence rates can be higher. Excellent results can be obtained at large-volume centres. With close follow-up, local recurrences can be identified and treated promptly (often with further local excision).

OBJECTIVE

• To describe the outcomes of organ-preserving surgery for penile cancer at a UK tertiary referral centre.

PATIENTS AND METHODS

• Patients at Sunderland Hospital (UK) between 2001 and 2008 who had squamous cell tumours limited to the glans penis underwent penile-preserving surgery including total glansectomy and glanuloplasty, partial glansectomy, glans relining and distal penectomy with glans reconstruction. • Recurrence rates, cosmetic and functional outcomes were recorded.

RESULTS

• In all, 65 patients were identified with a median follow-up of 40 months. Local recurrence was present in four patients (6%) despite 72% having intermediate or poorly differentiated tumours and 30% with T2 disease. • Complications included partial graft loss (1.5%), graft contractures (4.5%) and meatal stenosis (7.5%). • In all, 5% were deemed to have poor cosmetic outcome and 85% described good erections at 1 year after surgery.

CONCLUSION

• Penile-preserving surgery can achieve good penile cancer control with minimal morbidity and reduced psychosexual side-effects.

Pharmacokinetic interaction of garlic and atorvastatin in dyslipidemic rats

Objective:

To assess pharmacokinetic interaction of garlic with atorvastatin in dyslipidemic rats.

Materials and Methods:

Sprague Dawley rats with induced dyslipidemia were divided into five groups of eight rats each. Group 1 was given atorvastatin (10 mg/kg body weight (b.wt) orally), group 2 was given atorvastatin (10 mg/kg b.wt orally)+garlic (1% w/w in feed), group 3 was maintained on atorvastatin (5 mg/kg b.wt orally)+garlic (0.5% w/w in feed), group 4 was maintained on atorvastatin (7.5 mg/kg b.wt orally)+garlic (0.25% w/w in feed), and group 5 was maintained on atorvastatin (2.5 mg/kg b.wt orally)+garlic (0.75% w/w in feed) for 12 weeks. Blood samples were collected at predetermined time intervals for kinetic analysis after the first and last oral dosing of atorvastatin for single and multiple dose studies, respectively. Plasma samples were assayed for atorvastatin concentration by High-Performance Liquid Chromatography (HPLC) and then the concentration-time data were analyzed.

Results:

Maximum observed plasma concentration (C_max), half-life, Area Under Plasma Concentration Time Curve (AUC), and Mean Resident Time (MRT) were significantly (P<0.05) increased during multiple dose kinetic study and elimination rate constant was significantly (P<0.05) decreased in comparison with their respective single-dose values, while there was no significant difference in time to achieve maximum concentration (t_max) in all groups during both phases of the study. The highest values for kinetic parameters were observed in group 2 with correspondingly low activity of Cytochrome P₄₅₀ (CYP₄₅₀).

Conclusion:

The study revealed higher values [C_max, AUC, Area Under The Moment Curve (AUMC), MRT, and half-life] of atorvastatin in garlic-treated groups.

Protective effect of Tribulus terrestris linn on liver and kidney in cadmium intoxicated rats

Administration of cadmium (Cd) significantly increased the peroxidation markers such as malondialdehyde and protein carbonyls along with significant decrease in antioxidant markers such as super oxide dismutase and reduced glutathione in liver and kidney tissues. Cadmium also caused a significant alteration in hepatic and renal functional markers in serum viz. total protein, albumin, alanine transaminase, blood urea nitrogen and creatinine. Prominent pathological changes observed in liver were severe vascular and sinusoidal congestion with diffuse degenerative changes and mononuclear infiltration into peripheral areas, while the kidney showed vascular and glomerular congestion, cloudy swelling of tubular epithelium. Coadministration of ethonolic extract of T. terrestris or vitamin E along with Cd significantly reversed the Cd induced changes along with significant reduction in Cd load.

Protective effect of an aphrodisiac herb Tribulus terrestris Linn on cadmium-induced testicular damage

Aim:

The aim of the present study was to investigate whether Tribulus terrestris Linn (TT) could protect the cadmium (Cd)-induced testicular tissue peroxidation in rats and to explore the underlying mechanism of the same.

Materials and Methods:

In vitro and in vivo studies were conducted to know the protective effect of ethanolic extract of TT (eTT) in Cd toxicity. In in vitro studies, total antioxidant and ferrous metal ion chelating activity of TT was studied. In vivo studies were conducted in rats. A total of 40 Wistar strain adult male rats were divided into four groups. Group 1 served as control, while group 2 to 4 received CdCl₂ (3 mg/kg b. wt. s/c once a week). In addition to Cd, group 3 and 4 rats also received eTT (5 mg/kg b.wt. daily as oral gavage) and α-tocopherol (75 mg/kg daily by oral gavage), respectively. At the end of 6^th week, all the rats were sacrificed and the separated testes were weighted and processed for estimation of tissue peroxidation markers, antioxidant markers, functional markers, and Cd concentration. The testes were also subjected to histopathological screening.

Results:

In in vitro studies, the percentage of metal ion chelating activity of 50 μg/ml of eTT and α-tocopherol were 2.76 and 9.39, respectively, and the antioxidant capacity of eTT was equivalent to 0.063 μg of α-tocopherol/μg of eTT. In in vivo studies, administration of Cd significantly reduced the absolute and relative testicular weight, antioxidant markers such as superoxide dismutase and glutathione, and functional markers such as LDH and ALP, along with significant increase in peroxidation markers such as malondialdehyde and protein carbonyls in testicular tissue. Testes of Cd only-treated group showed histological insults like necrotic changes in seminiferous tubules and interstitium, shrunken tubules with desquamated basal lamina, vacuolization and destruction of sertoli cells, and degenerating Leydig cells. This group also had higher Cd levels in testicular tissue. Co-treatment with eTT and α-tocopherol significantly reduced the Cd burden in the testes along with reversal of the Cd-induced changes.

Conclusions:

eTT exhibited protective effect against Cd-induced testicular damage. The protective effect appears to be mediated through inhibition of testicular tissue peroxidation by antioxidant and metal chelator activity and also, may be indirectly by stimulating the testosterone production from Leydig cells.

Reversal of Cadmium-induced Oxidative Stress in Chicken by Herbal Adaptogens Withania Somnifera and Ocimum Sanctum

The present study was carried out to evaluate the herbal adaptogens Withania somnifera and Ocimum sanctum on cadmium-induced oxidative toxicity in broiler chicken. Cadmium administration at the rate of 100 ppm orally along with feed up to 28 days produced peroxidative damage, as indicated by increase in TBARS, reduction in glutathione (GSH) concentration in liver and kidney, and increase in catalase (CAT) and superoxide dismutase (SOD) of erythrocytes. Herbal adaptogens Withania somnifera roots and Ocimum sanctum leaf powder administration at the rate of 0.1% through feed reversed the antioxidant enzyme of RBC, i.e., CAT and SOD, nonenzymatic antioxidants GSH and lipid peroxidation marker TBARS of liver and kidney. Liver and kidney tissue repair and normal function was assessed by alanine aminotransaminase for liver and creatinine and blood urea nitrogen for kidney. In conclusion, oral administration of Withania somnifera root and Ocimum sanctum leaf powder prevented cadmium-induced peroxidation of tissues.

Evaluation of Wound Healing Potential of Bauhinia purpurea Leaf Extracts in Rats

The present study was carried out to evaluate the effect of methanol and chloroform extracts of Bauhinia purpurea on experimentally induced excision, incision, burn and dead space wound models in Sprague Dawley rats. Formulations of methanol and chloroform extracts of Bauhinia purpurea were prepared in carbopol and simple ointment base at concentrations of 2.5% and 5% and applied to the wounds. In the excision and burn wound models, animals treated with high doses of methanol and chloroform showed significant reduction in time taken for epithelization and wound contraction (50%) compared to control. A significant increase in breaking strength was found in incision wound model with methanol and chloroform extracts compared to their respective bases. In the dead space wound model, methanol and chloroform extract treatment (100 and 500 mg/kg) orally produced a significant increase in the breaking strength, dry tissue weight and hydroxyproline content of the granulation tissue when compared to control. Among the extracts, methanol extract exhibited more activity followed by the chloroform extract. In conclusion, the present study indicated that Bauhinia purpurea leaves exhibited wound healing activity.

Prevention of cadmium bioaccumulation by herbal adaptogens

Objectives:

To evaluate the effect of various herbal adaptogens such as shade-dried powders of Withania somnifera, Ocimum sanctum, Asperagus recemosus, Andrographis paniculata, Asphaltum panjabinum (Shilajith), Gymnema sylvestre, Spirulina platensis, and Panex ginseng on cadmium (Cd)-induced oxidative stress and its accumulation in broiler chicken.

Materials and Methods:

A total of 80 male broiler chicks of day old age were randomly assigned to 10 equal groups. Group 1 birds were fed with basal diet throughout the experiment (1–42 days). Group 2–10 chicks were fed with basal diet containing cadmium at 100 ppm from day 1 to day 28 (4 weeks). From 29^th to 42^nd day (2 weeks), basal diet alone was fed to group 2 chicks which acted as toxic control and group 3–10 birds were fed with feed containing 0.1% powder of W. somnifera, O. sanctum, Aspe. recemosus, An. paniculata, Asph. panjabinum (Shilajith), G. sylvestre, S. platensis, and P. ginseng, respectively. Body weight gain, levels of non-enzymatic antioxidants such as reduced glutathione (GSH), lipid peroxidation markers such as thiobarbituric acid reacting substances (TBARS), liver functional markers such as serum alanine transaminase (ALT), kidney functional markers such as blood urea nitrogen (BUN) and serum creatinine and concentration of cadmium in liver and kidney were investigated.

Results:

Body weight gains were significantly decreased in birds of groups 2–10 compared to group 1 at the end of 4^th week. Supplementation of various medicinal herbs in feed after 4^th week significantly improved the body weight gain compared to that in group 2 chicks. The increase in TBARS and decrease in GSH concentrations of liver and kidney tissues in cadmium intoxicated birds were significantly reversed by the above-said herbs. The liver and kidney functional markers were also restored to normal levels. Highest concentration of cadmium was found accumulated in kidney, followed by liver in birds of group 2. Herbal supplementation in groups 3–10 prevented Cd bioaccumulation which was most evident in liver, followed by kidney.

Conclusions:

Administration of herbal adaptogens at the rate of 0.1% in feed significantly prevented the bioaccumulation of Cd and reversed the Cd-induced oxidative tissue damage.

Protective effect of alpha-tocopheral on biochemical and histological alterations induced by cadmium in rat testes

Cadmium (Cd) is a potential environmental pollutant and causes severe damage to reproductive organs in adults including ovary and testes. Of all antioxidants alpha-tocopheral is considered to be most potent chain breaking antioxidant. Our aim was to study the effect of alpha-tocopheral on biochemical and histological alterations induced by Cd in testes of rats. Group 1 served as control, while groups 2 and 3 received subcutaneous injections of CdCl2 (3 mg/kg b.wt) once a week for four weeks. Group 3 in addition received alpha-tocopheral (75 mg/kg b.wt.) orally, daily for six weeks. Cadmium caused testicular tissue biochemical alterations such as significant increase in MDA, a peroxidation marker, decrease in antioxidant markers viz SOD, CAT and GSH and functional markers viz ALP and LDH. Histological alteration induced by Cd consisted of desquamation of basal lamina, shrunken tubules, generalized germ cell depletion with multinucleated gaint cells, degenerating Leydig cells, vascular congestion, interstitial edema and significant reduction in spermatodynamic count. Alpha-tocopheral significantly reversed all the Cd induced alterations. These results indicate that alpha-tocopheral has a protective effect against Cd indeed biochemical and histological alterations in rat testes.

Evaluation of significant sources influencing the variation of water quality of Kandla creek, Gulf of Katchchh, using PCA

To evaluate the significant sources contributing to water quality parameters, we used principal component analysis (PCA) for the interpretation of a large complex data matrix obtained from the Kandla creek environmental monitoring program. The data set consists of analytical results of a seasonal sampling survey conducted over 2 years at four stations. PCA indicates five principal components to be responsible for the data structure and explains 76% of the total variance of the data set. The study stresses the need to include new parameters in the analysis in order to make the interpretation of principal components more meaningful. The PCA could be applied as a useful tool to eliminate multi-collinearity problems and to remove the indirect effect of parameters.

Axillary silicone lymphadenopathy presenting with a lump and altered sensation in the breast: a case report

Introduction

Silicone lymphadenopathy is a rare but recognised complication of procedures involving the use of silicone. It has a poorly understood mechanism but is thought to occur following the transportation of silicone particles from silicone-containing prostheses to lymph nodes by macrophages.

Case presentation

We report of a case involving a 35-year-old woman who presented to the breast clinic with a breast lump and altered sensation below her left nipple 5 years after bilateral cosmetic breast augmentations. A small lump was detected inferior to the nipple but clinical examination and initial ultrasound investigation showed both implants to be intact. However, mammography and magnetic resonance imaging of both breasts revealed both intracapsular and extracapsular rupture of the left breast prosthesis. The patient went on to develop a flu-like illness and tender lumps in the left axilla and right mastoid regions. An excision biopsy of the left axillary lesion and replacement of the ruptured implant was performed. Subsequent histological analysis showed that the axillary lump was a lymph node containing large amounts of silicone.

Conclusion

The exclusion of malignancy remains the priority when dealing with lumps in the breast or axilla. Silicone lymphadenopathy should however be considered as a differential diagnosis in patients in whom silicone prostheses are present.

Effects of subchronic coexposure to arsenic and endosulfan on the erythrocytes of broiler chickens: a biochemical study

Arsenic is a known global groundwater contaminant. The organochlorine insecticide endosulfan has gained significance as an environmental pollutant due to its widespread use in the control of many food- and non-food-crop-damaging insects. The adverse effects produced by arsenic or endosulfan alone in humans and animals are well documented, but very little is known about the consequences of their coexposure. We evaluated whether their simultaneous exposure can induce oxidative stress and affect antioxidative systems and certain membrane-bound enzymes in erythrocytes of broiler chickens. Day-old chicks were exposed to 3.7 ppm of arsenic via drinking water or 30 ppm of endosulfan-mixed feed or similarly coexposed to these in the same dose levels for 60 days. At term, the impact of their coexposure was assessed by evaluating lipid peroxidation (LPO), activities of superoxide dismutase (SOD), catalase, glutathione peroxidase (GPx), glutathione-S-transferase (GST), different ATPases and acetylcholinesterase (AChE) in erythrocytes, serum glucose, and levels of glutathione (GSH) and glycosylated hemoglobin (GHb) in blood. LPO was increased with all of the treatments. Catalase was decreased with endosulfan and the coexposure, but not with arsenic, whereas GSH was decreased with arsenic and endosulfan, but not with the coexposure. All of the treatments increased SOD and GPx activities. GST activity was increased only in the coexposed birds. None of the treatments affected the activities of total ATPase and Mg2+-ATPase. Na+-K+-ATPase activity was decreased in the endosulfan-treated and the coexposed birds. All three exposures increased erythrocyte AChE activity. Endosulfan increased the serum glucose level and arsenic and endosulfan increased GHb levels, but these were not altered in the coexposed birds. Erythrocyte protein content was insignificantly decreased with these treatments. Overall, the effects of coexposure were not appreciably different from either of the agents, except on AChE, GSH, and glucose. The results do not reflect any specific type of interaction between these agents in chicken erythrocytes, but they do indicate that the coexposure induces a low level of oxidative stress, which is comparable to that induced by arsenic or endosulfan.

Kramers-Kronig-constrained variational dielectric fitting and the reflectance of a thin film on a substrate

A test was made of the ability of Kramers-Kronig-constrained variational dielectric fitting to extract the optical conductivity of a thin film from reflectance data containing structure due to both thin film and substrate. The reflectance of a series of well-characterized thin films of SrRu(x)Mg(1-x)O(3) and SrRu(x)O(3) with a variety of thicknesses (approximately 56-300 nm) and dc resistivities (approximately 250-2200 micro Omega cm) was measured. The low frequency values of the extracted optical conductivities agree with the dc measurements, however, removal of features due to the substrate improves with increasing film thickness.

Simple multiresidue method for monitoring of trimethoprim and sulfonamide residues in buffalo meat by high-performance liquid chromatography

A simple, specific, and rapid analytical method for the determination of trimethoprim (TMP) and three sulfonamide (SA) antimicrobial drug residues in buffalo meat is developed and validated. This method is based on a solid-phase extraction technique followed by high-performance liquid chromatography (HPLC)-photodiode array (PDA) detection. Target compounds were extracted from the meat by acetonitrile and water, cleaned up on a Bond Elute C 18 cartridge column, and separated on a RP-C 18 column during HPLC analysis. Acetonitrile along with water appears to be an excellent extractant as recovery of the analytes at maximum residues levels (MRLs) in spiked sample was in the range of 75-108%, with coefficient of variations (CVs) ranging between 1.34 and 22%. The limit of detection (LOD) and the limit of quantification (LOQ) were 0.031 and 0.062 microg/g, respectively, for all of the compounds. Intra- and interday assay precisions of the method at 0.125 microg/g concentrations for any drug ranged between 3 and 4%. The linearities of the TMP, sulfadimidine (SDM), sulfadoxine (SDO), and sulfamethoxazole (SMX) were 0.9989, 0.9999, 0.9998, and 0.9997, respectively. For robustness, the analytical method was applied to 122 buffalo meat samples obtained from export meat processing plants.

Comparative plasma pharmacokinetics of meloxicam in sheep and goats following intravenous administration

Meloxicam, a novel cyclooxygenase-2 selective nonsteroidal anti-inflammatory drug (NSAID), has been used extensively in humans and recently in some domestic animal species. Although it is an attractive NSAID for use in small ruminants, meloxicam pharmacokinetics have not been investigated in sheep and goats and this information is essential for rational therapeutic use of the drug in these species. In this investigation, comparative pharmacokinetic properties of meloxicam were studied in sheep and goats after a single intravenous dose of 0.5 mg kg(-1) body mass. Blood samples were collected via jugular venepuncture into heparinised tubes at predetermined times after drug administration. Plasma concentrations of meloxicam were determined by reversed-phase high performance liquid chromatography. The plasma concentrations of meloxicam were detectable in sheep and goats up to 72 and 48 h, respectively. The plasma concentration versus time data of meloxicam in both sheep and goats were adequately described by a two-compartment open model. The values obtained for sheep and goats for distribution half-life, volume of distribution at steady state and volume of the central compartment were almost similar in sheep and goats. The elimination half-life (t(1/2beta)), area under the plasma concentration-time curve (AUC), mean residence time (MRT) and total systemic clearance (Cl(B)) in sheep were significantly different from those of goats. The mean+/-S.E. values of t(1/2beta), MRT, AUC and Cl(B) in sheep were 10.85+/-1.21 h, 15.13+/-1.67 h, 31.88+/-2.97 microg h mL(-1) and 0.016+/-0.002 L h(-1) kg(-1), respectively whereas the respective values in goats were 6.73+/-0.58 h, 9.37+/-0.83 h, 19.23+/-2.23 microg h mL(-1) and 0.03+/-0.01 L h(-1) kg(-1). The results indicate that elimination kinetics of meloxicam differ significantly between sheep and goats and the elimination of the drug tends to be faster in goats compared to sheep.

Pharmacokinetics and bioavailability of nimesulide in goats

The pharmacokinetic properties and bioavailability of cyclooxygenase (COX)-2 selective nonsteroidal anti-inflammatory drug nimesulide were investigated in female goats following intravenous (i.v.) and intramuscular (i.m.) administration at a dose of 4 mg/kg BW. Blood samples were collected by jugular venipuncture at predetermined times after drug administration. Plasma concentrations of nimesulide were determined by a validated high-performance liquid chromatography method. Plasma concentration-time data were subjected to compartmental analysis and pharmacokinetic parameters for nimesulide after i.v. and i.m. administration were calculated according to two- and one-compartment open models respectively. Following i.v. administration, a rapid distribution phase was followed by the slower elimination phase. The half-lives during the distribution phase (t1/2alpha) and terminal elimination phase (t1/2beta) were 0.11+/-0.10 and 7.99+/-2.23 h respectively. The steady-state volume of distribution (Vd(ss)), total body clearance (ClB) and mean residence time (MRT) of nimesulide were 0.64+/-0.13 L/kg, 0.06+/-0.02 L/h/kg and 11.72+/-3.42 h respectively. After i.m. administration, maximum plasma concentration (Cmax) of nimesulide was 2.83+/-1.11 microg/mL attained at 3.6+/-0.89 h (tmax). Plasma drug levels were detectable up to 72 h. Following i.m. injection, the t1/2beta and MRT of nimesulide were 1.63 and 1.73 times longer, respectively, than the i.v. administration. The bioavailability of nimesulide was 68.25% after i.m. administration at 4 mg/kg BW. These pharmacokinetic data suggest that nimesulide given intramuscularly may be useful in the treatment of inflammatory disease conditions in goats.

Effects of low-level arsenic exposure on the developmental toxicity of anilofos in rats

In view of the increased use of anilofos for crop protection and ever increasing arsenic levels in drinking water in many countries, the coexistence of arsenic and anilofos in the environment is a reality and simultaneous exposure of humans and animals to these contaminants could be potentially hazardous. The aim of the present study was to examine whether coexposure to arsenic at the groundwater contamination level could alter the embryofetal toxicity of anilofos in rat model. Anilofos (100 mg kg(-1) day(-1)) and sodium arsenite (1 mg arsenic kg(-1) day(-1)) were administered by gavage either individually or in combination to the pregnant rats from day 6 to day 15 of gestation. Arsenic did not produce any significant effects either on maternal or fetal parameters at the given dose. Anilofos alone significantly decreased maternal weight gain, feed and water intakes, gravid uterine weights, number of live fetuses and fetal body weights and increased resorptions. There were increased incidences of gross, skeletal and visceral anomalies in the fetuses of anilofos-treated group. The main skeletal abnormality was increased intercostal space, while the visceral anomaly was an interventricular septal defect. Treatment with the combination of arsenic and anilofos significantly enhanced the fetal changes with much greater magnitude compared with the effects produced by anilofos alone. Anomalies such as midfacial cleft, exencephaly and anophthalmia were seen only in the fetuses of the combination group. The results show that anilofos interferes with embryofetal development and coexposure with arsenic at environmentally realistic concentrations produces additive or synergistic effects on the developmental toxicity of anilofos in rats.

Effects of subchronic malathion exposure on the pharmacokinetic disposition of pefloxacin

Malathion is one of the most extensively used organophosphorus pesticides applied in agriculture, mosquito eradication and in the control of animal ectoparasites and human body lice. The widespread use of malathion has raised concern over its potential to cause untoward health effects in humans, animals and birds. Malathion inhibits cytochrome P450 monooxygenases and has the potential to alter pharmacokinetic profiles of therapeutic agents that are metabolized in the liver. The present study was undertaken to evaluate the impact of subchronic exposure of malathion on the pharmacokinetic disposition of pefloxacin. Chickens were given either normal diet or malathion through food at a concentration of 1000ppm for 28 days. Subsequently, pefloxacin was administered either intravenously or orally (control) to birds fed normal diet and orally to malathion-exposed chickens at a dosage of 10mgkg(-1) body weight. Blood samples were drawn from the brachial vein at predetermined time intervals after drug administration. Plasma was separated and analyzed for pefloxacin by reverse-phase high performance liquid chromatography. The plasma concentration-time data were analyzed by non-compartmental techniques. Following intravenous administration of pefloxacin, elimination half-life (t(1/2β)), area under the plasma concentration-time curve (AUC) and mean residence time (MRT) were 8.2±0.7h, 66±9μghml(-1) and 10.5±1.1h, respectively, and when the drug was administered orally, the respective values of pharmacokinetic parameters were 8.2±0.4h, 31±3.1μghml(-1) and 11.7±0.6h. Malathion exposure significantly increased maximum plasma drug concentration, t(1/2β), AUC and MRT of pefloxacin to 54, 22, 117 and 37% of control, respectively. These findings provide evidence that subchronic malathion exposure markedly influences the elimination kinetics of pefloxacin which may be due to malathion-mediated inhibition of metabolism of pefloxacin.

Pharmacokinetics and tissue residues of pefloxacin and its metabolite norfloxacin in broiler chickens

1. The pharmacokinetics of pefloxacin and its active metabolite norfloxacin were investigated in chickens after a single oral administration of pefloxacin at a dosage of 10 mg/kg. To characterise the residue pattern, another group of chickens was given 10 mg of pefloxacin/kg body once daily for 4 d by oral route; the tissue concentrations of pefloxacin and norfloxacin were determined at 1, 5 and 10 d after the last administration of the drug. 2. The concentrations of pefloxacin and norfloxacin in plasma and tissues were determined by HPLC assay. The limit of detection for pefloxacin and norfloxacin was 0.03 microg/ml in plasma or microg/g in tissue. 3. The plasma concentration-time data for pefloxacin and norfloxacin were characteristic of a one-compartment open model. The elimination half-life, maximum plasma drug concentration, time to reach maximum plasma drug concentration and mean residence time of pefloxacin were 8.74 +/- 1.48 h, 3.78 +/- 0.23 microg/ml, 3.33 +/- 0.21 h and 14.32 +/- 1.94 h, respectively, whereas the respective values of these variables for norfloxacin were 5.66 +/- 0.81 h, 0.80 +/- 0.07 microg/ml, 3.67 +/- 0.21 h and 14.44 +/- 0.97 h. 4. Pefloxacin was metabolised to norfloxacin to the extent of 22%. 5. The concentrations of pefloxacin (microg/g) 24 h after the fourth dose of the drug declined in the following order: liver (3.20 +/- 0.40) > muscle (1.42 +/- 0.18) > kidney (0.69 +/- 0.04) > skin and fat (0.06 +/- 0.02). Norfloxacin was also detectable in all the tissues analysed except muscle. No drug and/or its metabolite was detectable in tissues except skin and fat 5 d after the last administration. The concentrations of pefloxacin and norfloxacin in skin and fat 10 d after the last dose of pefloxacin were 0.04 +/- 0.02 and 0.03 +/- 0.01 microg/g, respectively.

Interactive alterations of arsenic and malathion in the disposition kinetics of pefloxacin

Assessment of deleterious effects produced by concurrent exposure to commonly encountered chemicals is of great concern to find out toxicological consequences arising as a result of their interactions and for a more comprehensive management of chemical-induced untoward effects. The naturally occurring heavy metal arsenic is present in food and water. Malathion is one of the most widely used pesticides in agriculture and public health practices worldwide. Humans, animals, and birds are exposed to these chemicals through environmental processes. Since arsenic and malathion are shown to exert an inhibitory effect on cytochrome P450 activities, their continuous exposure may alter the disposition kinetics of drugs that are predominantly metabolized hepatically. The current study was undertaken to evaluate the impact of subchronic exposure of arsenic, malathion, and their combination on the disposition kinetics of widely used fluoroquinolone antimicrobial pefloxacin in chickens. Broiler chickens were exposed to either arsenic (50 ppm), malathion (500 ppm), or arsenic (50 ppm) plus malathion (500 ppm). Arsenic and malathion were given in drinking water and feed, respectively. Following 28 days of exposure, all birds received a single oral dose of pefloxacin (10 mg/kg) and the plasma concentrations and the disposition kinetic parameters of the drug were determined. In the birds not exposed to arsenic and/or malathion, the elimination half-life (t(1/2beta)), area under the plasma concentration-time curve (AUC), maximum plasma drug concentration (C(max)), mean residence time (MRT), and bioavailability of pefloxacin were 8.46 +/- 0.24 h, 39.06 +/- 1.13 microg.h.ml(-1), 2.69 +/- 0.19 microg.ml(-1), 12.29 +/- 0.48 h, and 60.52 +/- 1.74%, respectively. Exposure to arsenic was associated with a significant increase in C(max) (4.28 +/- 0.45 microg.ml(-1)) and a nonsignificant increase in the values of AUC (48.96 +/- 2.55 microg.h.ml(-1)) and bioavailability (74.55 +/- 3.8 %) of pefloxacin. The values of AUC (51.62 +/- 4.76 microg.h.ml(-1)), t(1/2beta) (12.57 +/- 1.26 h), MRT (19.94 +/- 1.99 h), and bioavailability (78.59 +/- 7.25 %) of pefloxacin were significantly increased in malathion-exposed birds. Concomitant exposure to arsenic and malathion did not affect the disposition kinetic variables of pefloxacin. The study shows that subchronic malathion exposure significantly alters the elimination kinetics of pefloxacin. Following concurrent exposure, arsenic nullifies the malathion-induced changes in disposition kinetics of pefloxacin by possibly diminishing the cytochrome P450-catalyzed bioactivation of malathion.

Residues of fluoroquinolone drugs in the cloacal gland and other tissues of Japanese quail

1. In this study we investigated the residues of fluoroquinolone drugs (ciprofloxacin and pefloxacin) in the cloacal gland (a site of foam synthesis) and other tissues such as breast muscle, testes, brain, kidney and plasma. 2. Fifty-four healthy male Japanese quail were selected at random from a flock, maintained under uniform husbandry conditions and divided into three groups, each of 18 birds. Group I (control) received 1 ml vehicle (normal saline 0.9% (w/v) NaCl) daily for 12 d through the intraperitoneal route. Birds of groups II and III received ciprofloxacin and pefloxacin by the same route at the rate of 10 and 12 mg/kg body weight, respectively, every day for a similar period. 3. Birds from each group were killed, at 1, 5 and 10 d after the cessation of treatment, to collect the cloacal gland together with other tissues that were analysed for residual drugs. 4. Cloacal gland retained the maximum drug residues of ciprofloxacin (60%) and pefloxacin (80%) on d 10 compared with that on d 1 after drug withdrawal. The drug residues were found 60 and 80% in ciprofloxacin and pefloxacin groups, respectively, in the cloacal gland tissue even on d 10 after withdrawal of the treatment. 5. In the ciprofloxacin-treated group, all tissues except cloacal gland contained very small amounts of the drug residues on d 10 after treatment ended. In the pefloxacin group the cloacal gland, breast muscle and kidney retained a fairly high amount of drug even on d 10 after treatment ceased. No residues of pefloxacin were detectable in testes and brain throughout. 6. In conclusion, the cloacal gland in Japanese quail acted as the largest sink for the fluoroquinolone drugs. Ciprofloxacin was more widely distributed in different tissues and persisted for a shorter period than pefloxacin.

Unplanned admissions following ambulatory plastic surgery--a retrospective study

INTRODUCTION

Admission for overnight or longer hospital stay from a day-case unit is an unwelcome event. This audit was designed to identify the incidence of unplanned admissions and also to detect the potential factors for such overstays.

PATIENTS AND METHODS

Details of plastic surgical day-case patients were obtained from the hospital records for a period of 6 months (February 2002 to July 2002).

RESULTS

The total number of unplanned admissions was 28 (3.55%). High rates were recorded in patients above the age of 80 years, male patients and body mass index > 30 kg/m2. Duration of surgery (> 45 min) and waiting time in the day surgery unit (> 2.5 h) had significant correlation with the overstays. Grade of the surgeon was not an important determinant factor. Of procedures which resulted in an unexpected admission, the most frequent were otoplasty (8.4%; n = 71) and fasciectomy for Dupuytren's contracture (14.5%; n = 41). Unexpected admissions were also high following rhinoplasty and nipple reconstruction but the total number of operations performed were not significant (n = 12 in each group). Overall, the cause of the overstays were mostly surgical (71.4%) followed by anaesthetic (28.5%) and social (7.1%).

DISCUSSION

With an overall unplanned admission rate of 3.55%, our unit is close to the national standard of 2-3%, as advocated by The Royal College of Surgeons of England. Postoperative bleeding (60%) was the most important surgical reason for overstays followed by intravenous antibiotics, wound drainage, excessive duration of the procedure and additional, unplanned procedures. Among the anaesthetic factors, postoperative pain was the leading cause (62.5%) followed by nausea, vomiting and adverse anaesthetic reaction.

CONCLUSIONS

The reasons for unplanned admissions are multifactorial and merit appropriate patient selection and proper estimation of the disease process.

In Vitro and In Vivo Evaluation of Guar Gum-Based Matrix Tablets of Rofecoxib for Colonic Drug Delivery

The present study was carried out to develop and evaluate guar gum-based matrix tablets of rofecoxib for their intended use in the chemoprevention of colorectal cancer. Matrix tablets containing 40% (RXL-40), 50% (RXL-50), 60% (RXL-60) or 70% (RXL-70) of guar gum were prepared by wet granulation technique, and were subjected to in vitro drug release studies. Guar gum matrix tablets released only 5 to 12% of rofecoxib in the physiological environment of stomach and small intestine. The matrix tablets RXL-40 disintegrated completely within 10 h in a dissolution medium without rat caecal contents (control study), and hence not studied further. When the dissolution study was continued in simulated colonic fluids (rat caecal content medium), the matrix tablets RXL-50 were acted upon by colonic bacterial enzymes releasing the entire quantity of drug wherein there was no appreciable difference when compared to that released in control study. The matrix tablets RXL-60 released another 88% of rofecoxib whereas matrix tablets RXL-70 released only 57% of rofecoxib in simulated colonic fluids indicating the susceptibility of the guar gum formulations to the rat caecal contents. The guar gum matrix tablets RXL-70 were subjected to in vivo evaluation in human volunteers to find their ability of targeting rofecoxib to colon. The delayed Tmax, prolonged absorption time (ta), decreased Cmax and decreased ka indicated that rofecoxib was not released significantly in stomach and small intestine, but was delivered to colon resulting in a slow absorption of the drug and making it available for local action in human colon.

Spontaneous keloids in siblings

The authors report two rare cases of 'non-syndromic spontaneous keloids' occuring in siblings. This represents another unexplored area in the field of 'keloid challenge', warranting further research and development.

Cutaneous changes in chronic alcoholics

BACKGROUND

Alcohol consumption can have a variety of cutaneous manifestations. Awareness of the cutaneous changes of alcohol abuse can allow early detection and intervention in an attempt to limit the adverse medical consequences. Hence a study was planned to determine the cutaneous changes in chronic alcoholics.

AIMS

To determine the cutaneous changes in chronic alcoholics.

METHODS

All the patients attending alcohol de-addiction camps were examined for cutaneous changes. The results were analyzed using Gausian test and compared with other reports.

RESULTS

Out of 200 alcoholics examined for cutaneous changes, 182 (91%) had cutaneous, nail, hair or oral cavity changes. Nail changes were found in 51 (25.5%) alcoholics, koilonychia being the commonest (16%). Oral changes were present in 107 (53.5%) alcoholics and changes due to nutritional deficiency in 20 (10%). Diseases due to poor hygiene were seen in 55 (27.5%) alcoholics. Tinea versicolor (14%) and seborrheic dermatitis (11.5%) were the commonest cutaneous changes noted.

CONCLUSION

Even though alcohol abuse has a variety of cutaneous manifestations and perhaps aggravates many diseases, there are no specific cutaneous signs of alcoholism. Knowledge of the spectrum of cutaneous manifestations of alcohol abuse can allow its early detection and treatment in an attempt to minimize the medical consequences.

Pattern of skin diseases in an Indian village

Disease pattern in a given population is generally determined by different ecological factors. Thus the objective of our study was to find out the pattern of skin diseases in a given population. Analysis of 3673 patients attending a medical camp at Kumble in Kerala state showed 410(11.16%) patients with dermatological problems. 260(63.41%) of them were males and 150(36.59%) females with a male to female ratio of 1.7:1. Of these patients, 178(43.41%) had cutaneous infections and 234(57.07%) had non-infectious dermatoses. Few patients had more than one dermatoses. Fungal infection was the commonest infection seen (22.92%) and eczemas took an upper hand in non-infectious group (32.19%). Improvement in the standard of living, education of the general public, improvement in the environmental sanitation and good nutritious food may help us to bring down the skin disease in this area.

Pharmacokinetic disposition of subcutaneously administered enrofloxacin in goats

The pharmacokinetic disposition of enrofloxacin was studied in goats after subcutaneous (s.c.) administration at a single dose of 7.5 mg/kg body weight. Blood samples were drawn from a jugular vein into heparinized tubes at predetermined time intervals after administration of the drug and the plasma was separated by centrifugation. The concentrations of enrofloxacin in the plasma were determined by a microbiological assay using Escherichia coli as the test organism. The plasma concentration-time data were analysed by non-compartmental methods. Enrofloxacin was rapidly absorbed, an appreciable concentration of the drug (0.30 +/- 0.13 microg/ml) being present in the plasma by 5 min after s.c. administration. The maximum plasma concentration of enrofloxacin and the time to reach that maximum were 2.91 +/- 0.39 microg/ml and 2.9 +/- 0.51 h. respectively. A detectable concentration of enrofloxacin persisted in the plasma for 12 h. The elimination half-life and mean residence time of enrofloxacin were 2.84 +/- 0.57 and 5.74 +/- 0.28 h, respectively. It is suggested that enrofloxacin given subcutaneously may be useful in the treatment of susceptible bacterial infections in goats.

Leprosy lesion on the prepuce of the male genitalia: a case report

A case of borderline leprosy in type I reaction with cutaneous lesions on the prepuce is reported. The need to examine the genitalia in all male leprosy patients is stressed.

Spectrophotometric determination of serum nitrite and nitrate by copper-cadmium alloy

A macro and micro assay for the spectrophotometric determination of serum nitrite and nitrate was developed. Nitrite/nitrate in biological samples can be estimated in a single step by this method. The principle of the assay is the reduction of nitrate by copper-cadmium alloy, followed by color development with Griess reagent (sulfanilamide and N-naphthylethylenediamine) in acidic medium. This assay is sensitive to 1 microM nitrate and is suitable for different biological fluids, including sera with a high lipid concentration. The copper-cadmium alloy used in the present method is easy to prepare and can completely reduce nitrate to nitrite in an hour. The present method provides a simple, cost-effective assay for the estimation of stable oxidation products of nitric oxide in biological samples.

Pharmacokinetics of pefloxacin in goats after intravenous or oral administration

The plasma concentrations and pharmacokinetics of the fluoroquinolone antimicrobial agent pefloxacin, following the administration of a single intravenous (10 mg/kg) or oral (20 mg/kg) dose, were investigated in healthy female goats. The antimicrobial activity in plasma was measured at predetermined times after drug administration by an agar well diffusion microbiological assay, using Escherichia coli (ATCC 25922) as the test organism. Concentrations of the drug > or = 0.25 microg/ml were maintained in plasma for up to 6 and 10 h after intravenous (i.v.) or oral administration of pefloxacin, respectively. The concentration time data for pefloxacin in plasma after i.v. or oral administration conformed to two- and one-compartment open models, respectively. Plasma pefloxacin concentrations decreased rapidly during the initial phase after i.v. injection, with a distribution half-life (t(1/2alpha)) of 0.10 +/- 0.01 h. The terminal phase had a half-life (t(1/2beta)) of 1.12 +/- 0.21 h. The volume of distribution at steady state (Vdss), mean residence time (MRT) and total systemic clearance (ClB) of pefloxacin were 1.08 +/- 0.09 L/kg, 1.39 +/- 0.23 h and 821 +/- 88 (ml/h)/kg, respectively. Following oral administration of pefloxacin, the maximum concentration in the plasma (Cmax) was 2.22 +/- 0.48 microg/ml and the interval from administration until maximum concentration (tmax) was 2.3 +/- 0.7 h. The absorption half-life (t(1/2ka)) mean absorption time (MAT) and elimination half-life of pefloxacin were 0.82 +/- 0.40, 4.2 +/- 1.0 and 2.91 +/- 0.50 h, respectively. The oral bioavailability of pefloxacin was 42% +/- 5.8%. On the basis of the pharmacokinetic data, a dosage regimen of 20 mg/kg, i.v. at 8 h intervals or orally twice daily, is suggested for treating infections caused by drug-sensitive pathogens in goats.

Effect of tamarind ingestion on fluoride excretion in humans

OBJECTIVE

To evaluate the effect of tamarind (Tamarindus indicus) ingestion on excretion of fluoride in school children.

DESIGN

Randomized, diet-control study.

SUBJECT

Twenty healthy boys were included and 18 of them completed the study.

INTERVENTIONS

Each subject consumed 10 g tamarind daily with lunch for 18 days at the social welfare boys' hostel. The nutrient composition of the daily diet was constant throughout the experimental period.

RESULTS

Tamarind intake led to significant increase (P<0.001) in the excretion of fluoride in 24 h urine (4.8+/-0.22 mg/day) as compared to excretion on control diet (3.5+/-0.22 mg/day). However, excretion of magnesium and zinc decreased significantly (7.11+/-1.48 mg of Mg and 252.88+/-12.84 microg of Zn per day on tamarind diet as compared to 23.39+/-3.68 mg of Mg and 331.78+/-35.31 microg Zn per day on control diet). Excretion of calcium and phosphorous were not significantly different while creatinine excretion decreased with tamarind intake (225.66+/-81 mg creatinine/day with tamarind and 294.5+/-78.76 mg creatinine/day without tamarind).

CONCLUSION

Tamarind intake is likely to help in delaying progression of fluorosis by enhancing urinary excretion of fluoride.

Pharmacokinetics of enrofloxacin and its metabolite ciprofloxacin in goats given enrofloxacin alone and in combination with probenecid

The pharmacokinetics of enrofloxacin and its active metabolite ciprofloxacin were investigated in goats given enrofloxacin alone or in combination with probenecid. Enrofloxacin was administered i.m. at a dosage of 5 mg x kg(-1) alone or in conjunction with probenecid (40 mg x kg(-1), i.v.). Blood samples were drawn from the jugular vein at predetermined time intervals after drug injection. Plasma was separated and analysed simultaneously for enrofloxacin and ciprofloxacin by reverse-phase high performance liquid chromatography. The plasma concentration-time data for both enrofloxacin and ciprofloxacin were best described by a one-compartment open pharmacokinetic model. The elimination half-life (t(1/2beta)), area under the plasma concentration-time curve (AUC), volume of distribution (V(d(area))), mean residence time (MRT) and total systemic clearance (Cl(B)) were 1.39 h, 7.82 microg x h x mL, 1.52 L x kg(-1), 2.37 h and 802.9 mL x h(-1) x kg(-1), respectively. Enrofloxacin was metabolized to ciprofloxacin in goats and the ratio between the AUCs of ciprofloxacin and enrofloxacin was 0.34. The t(1/2beta), AUC and MRT of ciprofloxacin were 1.82 h, 2.55 microg x h x mL and 3.59 h, respectively. Following combined administration of probenecid and enrofloxacin in goats, the sum of concentrations of enrofloxacin and ciprofloxacin levels > or = 0.1 microg x mL(-1) persisted in plasma up to 12 h.Co-administration of probenecid did not affect the t(1/2beta), AUC, V(d (area)) and Cl(B) of enrofloxacin, whereas the values of t(1/2beta) (3.85 h), AUC (6.29 microg x h x mL), MRT (7.34 h) and metabolite ratio (0.86) of ciprofloxacin were significantly increased. The sum of both enrofloxacin and ciprofloxacin levels was > or = 0.1 microg x mL(-1) and was maintained in plasma up to 8 h in goats after i.m. administration of enrofloxacin alone. These data indicate that a 12 h dosing regime may be appropriate for use in goats.

Intraoperative blood glucose levels in neurosurgical patients : an evaluation of two fluid regimens

Based on the evidence that hyperglycaemia aggravates ischaemic cerebral injury, it has been suggested that blood glucose levels be kept within 200 mg/dL during intracranial neurosurgery. Hypoglycaemia, however, can be a serious problem if glucose-containing solutions are avoided during the first four hours, as suggested in some studies. In order to explore the possibility of administering glucose in moderation so that the blood glucose levels are within acceptable limits, but at the same time the risk of hyoglycaemia is eliminated, we compared two intraoperative fluid regimens. Of the 52 neurosurgical patients studied, 32 patients received alternately 500 ml of 5% dextrose in normal saline and Ringer's lactate (DNS/RL Group) and 18 patients received alternately 500 ml of Ringer's lactate and normal saline (RL/NS Group). Blood glucose concentrations were determined at the end of each unit of fluid, until the patient received 4 units of fluid. In the DNS/RL group, blood glucose values peaked with the administration of each unit of DNS and tended to return towards the baseline with the subsequent RL, but remained higher than the previous control value. In the RL/NS group, there was a progressive increase in blood glucose values throughout the study period, but the increase was not statistically significant. The blood glucose levels were significantly different between the two groups after each unit of fluid except at the end of the fourth unit. Two patients in the RL/NS group had hypoglycaemia. In conclusion, the DNS/RL regimen maintains blood glucose levels within acceptable limits while avoiding the risk of hyperglycaemia. Withholding glucose completely, lowers blood glucose levels, but carries a risk of hypoglycaemia in some patients.

Release of iron from ferritin by metabolites of benzene and superoxide radical generating agents

The release of iron from ferritin in the presence of benzene metabolites, viz. phenol (P), catechol (CT), hydroquinone (HQ) and superoxide radical generating compounds, viz. pyrogallol (PL), phloroglucinol (PG), phenylhydrazine (PH) or phenylenediamine (PD) was studied in acetate buffer, pH 5.6. Monitoring the formation of the iron-ferrozine complex quantitated the release of iron from ferritin. The presence of P (125 microM) did not result in the release of iron from ferritin, whereas the same concentration of CT, HQ, PL, PH or PD resulted in the release of significant amounts of iron from ferritin and a marginal amount of iron in the presence of PG, CT, HQ, PL, PH or PD concentration and time-dependent increase in iron release from ferritin were observed although the increase was not linear as a function of time and concentration of the compounds studied. The presence of superoxide dismutase inhibited significantly the release of iron from ferritin by CT, HQ, PL, PH or PD. The iron released from ferritin by CT, HQ, PL, PH or PD enhanced lipid peroxidation in rat brain homogenate and released aldehydic products from bleomycin-dependent degradation of DNA and also caused single strand nicks to pUC18 DNA. These studies indicate that CT and HQ, the two principal polyphenolic metabolites of benzene and PL, PH or PD, the superoxide radical generating compounds were capable of reducing ferric iron from ferritin and also mobilizing and releasing iron from ferritin core. The release of iron from ferritin by these compounds is a result of direct reduction of ferritin iron by electron transfer and also reduction via superoxide radical. The release of iron from ferritin by CT and HQ may have toxicological implications in relation to benzene toxicity. The release of iron by superoxide radical generating agents suggests that oxidative stress may play a role as this could lead to disruption of intracellular iron homeostasis.

Borderline tuberculoid leprosy of the scalp

A case of borderline tuberculoid leprosy involving the hairy scalp is reported. To the best of our knowledge, only two paucibacillary leprosy patients with scalp lesion have been reported, and in only one was the scalp covered with hair.

Cardiovascular Responses to Scalp Infiltration with Different Concentrations of Epinephrine With or Without Lidocaine During Craniotomy

Intraoperative blood pressure changes alter cerebral blood flow in neurosurgical patients with impaired autoregulation. Infiltration of the scalp before craniotomy may cause hemodynamic changes that depend on the composition of the solution used. We investigated cardiovascular responses to infiltration of the scalp with five different combinations of epinephrine and lidocaine in 112 patients: Group A, lidocaine 0.5%; Group B, lidocaine 0.5% with epinephrine 1:200,000; Group C, lidocaine 0.5% with epinephrine 1:100,000; Group D, normal saline with epinephrine 1:200,000; and Group E, normal saline with epinephrine 1:100,000. Episodes of tachycardia occurred more frequently in group E (P = 0.03). Plain lidocaine did not cause any significant change in blood pressure. The incidence of systolic, diastolic, and mean arterial hypertension was significantly increased in group E (P < 0.01). Episodes of diastolic hypertension occurred more frequently in Group D (P < 0.01). A biphasic diastolic and mean arterial hypotension (around Minute 2 and Minutes 9-15) occurred in Groups C and B (P < 0.001). In conclusion, epinephrine 1:100,000 causes significant tachycardia. Epinephrine in concentrations of 1:100,000 and 1:200,000 causes significant hypertension. The combination of lidocaine and epinephrine attenuates the hypertension but results in a biphasic hypotensive response.

Onychocryptosis-phenol burn fiasco

Ingrowing toenails, onychocryptosis, are a common condition that can be treated conservatively or surgically. Conservative treatment often fails necessitating operative intervention. Surgical treatments include wedge resection, Zadik's procedure and nail removal with ablation of the germinal matrix by phenol. The following report describes a 15-year-old male footballer who sustained burns following phenol treatment, resulting in amputation of his left great toe, as well as suggestions to avoid any similar complications.

Pharmacokinetics of enrofloxacin and its metabolite ciprofloxacin after intramuscular administration of enrofloxacin in goats

The pharmacokinetics of enrofloxacin and its active metabolite ciprofloxacin were investigated in goats after a single intramuscular administration of enrofloxacin at 2.5 mg/kg body weight. The plasma concentrations of enrofloxacin and ciprofloxacin were determined simultaneously by a HPLC method. The peak concentrations (Cmax) of enrofloxacin (1.13 microg/ml) and ciprofloxacin (0.24 microg/ml) were observed at 0.8 and 1.2 h, respectively. The elimination half-life (t1/2beta), volume of distribution (Vd(area)), total body clearance (Cl(B)) and mean residence time (MRT) of enrofloxacin were 0.74 h, 1.42 L/kg, 1329 ml/h per kg and 1.54 h, respectively. The t1/2beta, area under the plasma concentration-time curve (AUC) and the MRT of ciprofloxacin were 1.38 h, 0.74 microg h/ml and 2.73 h, respectively. The metabolic conversion of enrofloxacin to ciprofloxacin was appreciable (36%) and the sum of the plasma concentrations of enrofloxacin and ciprofloxacin was maintained at or above 0.1 microg/ml for up to 4 h. Enrofloxacin appears to be useful for the treatment of goat diseases associated with pathogens sensitive to this drug.

A peptide inhibitor of HIV-1 protease using alpha, beta- dehydro residues: a structure based computer model

HIV-1 encodes an aspartic protease, an enzyme crucial to viral maturation and infectivity. It is responsible for the cleavage of various protein precursors into viral proteins. Inhibition of this enzyme prevents the formation of mature, infective viral particles and therefore, it is a potential target for therapeutic intervention following infection. Several drugs that inhibit the action of this enzyme have been discovered. These include peptidomimetic inhibitors such as ABT-538 and saquinavir, and structure based inhibitors such as indinavir and nelfinavir. Several of these have been tested in human clinical trials and have demonstrated significant reduction in viral load. However, most of them have been found to be of limited clinical utility because of their poor pharmacological properties and also because the viral protease becomes rapidly resistant to these drugs on account of mutations in the enzyme. One way to overcome these limitations is to design an inhibitor that interacts mainly with the conserved residues of HIV-1 protease. By a rational drug design approach based on the high resolution X-ray crystal structure of the HIV-1 protease with--MVT 101 (a substrate based inhibitor) and the specific design principles of peptides containing dehydro-Alanine (delta Ala) derived from our earlier studies, we have designed a tetrapeptide with the sequence: NH2-Thr-delta Ala-delta Ala-Gln-COOH. Energy minimization and molecular modelling of the interaction of the designed tetrapeptide with the inhibitor binding site indicate that the inhibitor is in an extended conformation and makes excessive contacts with the viral enzyme at the interface between the protein subunits. The designed inhibitor has 33% of its interaction with the conserved region of HIV-1 protease which is of the same order as that of MVT 101 with the enzyme.

Long-term follow up of multibacillary leprosy patients with high BI treated with WHO/MDT regimen for a fixed duration of two years

Forty-six, newly detected, previously untreated multibacillary (MB) patients with a bacterial index (BI) of > or = 3+ who had received WHO/MDT for 2 years were followed up for a total duration of 424 person-years and a mean duration of 9.26 +/- 2.98 years per patient. The BIs of the patients continued to fall, and all of the patients, except one, reached skin-smear negativity. WHO/MDT was well accepted and well tolerated. Relapse, which was defined as an increase in the BI of 1+ or more with or without clinical evidence of activity, was observed in only one patient, giving a relapse rate of 2.2% or 0.23 per 100 person-years in patients with a BI of > or = 3+ after long-term follow up. This patient was started on a second course of WHO/MDT to which he responded favorably. WHO/MDT for a fixed duration of 2 years for MB patients as recommended by the WHO is vindicated.

Radiosensitization of human breast cancer cells by a novel ErbB family receptor tyrosine kinase inhibitor

PURPOSE

Overexpression of the ErbB family of growth factor receptors is present in a wide variety of human tumors and is correlated with poor prognosis. The purpose of this study was to determine the effects of a novel small molecule ErbB tyrosine kinase inhibitor, CI-1033, in combination with ionizing radiation on breast cancer cell growth and survival.

MATERIALS & METHODS

Growth assays were performed on ErbB-overexpressing human breast cancer cells developed in our laboratory in the presence of 0.1-1.0 microM CI-1033 (Parke Davis). Clonogenic survival assays were performed in the presence of ionizing radiation with or without CI-1033. For some experiments, clonogen numbers, defined as the product of surviving fraction and total number of cells, were calculated at each time point during a course of multifraction radiation.

RESULTS

CI-1033 potently inhibited the growth of ErbB-overexpressing breast cancer cells. A single 48-h exposure of 1 microM CI-1033 resulted in growth inhibition for 7 days, whereas three times weekly administration resulted in sustained growth inhibition. Clonogenic survival was modestly decreased after a 7-day exposure to CI-1033. Exposure to both CI-1033 and radiation (6 Gy) yielded a 23-fold decrease in clonogenic survival compared to radiation alone. In a multifraction experiment, exposure to CI-1033 and three 5-Gy fractions of gamma radiation decreased the total number of clonogens in the population by 65-fold compared to radiation alone.

CONCLUSION

CI-1033 results in potent growth inhibition and modest cytotoxicity of ErbB-overexpressing breast cancer cells, and has synergistic effects when combined with ionizing radiation. These data suggest that CI-1033 may have excellent clinical potential both alone and in combination with radiation therapy.