Clonal diversity and zoonotic potential of MDR Escherichia coli isolated from poultry at different age intervals

1. A pool of 480 E. coli isolates of poultry (broilers and ducks) representing different time intervals (0, 10, 20 and 30 days) was selected for ribotyping and used to determine polymorphism of 16-23S ribosomal RNA intergenic space. All the isolates were multidrug-resistant (MDR).2. Out of these, 10 isolates were tested for MultiLocus Sequence Typing (MLST) among which novel allelic combinations and therefore new sequence types were identified in seven isolates.3. This work showed the changes in E. coli strains structure at farm level and individual bird level in host species raised on organised farms with similar parental lineage and environmental housing. The statistical results showed that the structure of variation is very different by farm, supporting a strong effect of location, which confirms the temporal clustering.4. There were significant differences between E. coli strains in chickens and ducks, indicating host specificity of the E. coli strains.5. Some of the pathogenic E. coli strains found using MLST belonged to ST735, ST2796 and a pandemic clone ST752 of ST10 clonal complex. The results strongly suggested the clonal expansion and establishment of specific MDR clones that have zoonotic relevance.

676 Paediatric Circumcisions- Compliance with RCS Standards

Introduction

Variation in regional paediatric circumcision rates suggested some circumcisions were being performed unnecessarily. In 2016, the Royal College of Surgeons (RCS) released a clinical commissioning guide on foreskin conditions to standardise the indications for circumcision. We retrospectively audited the foreskin procedure practice at our urology department and its adherence to RCS clinical commissioning guidance.

Method

We assessed electronic health records for all paediatric patients (<17 years) having undergone a foreskin procedure from 1st Jan 2018 to 1st Jan 2019. Records were assessed for referral source, trial of medical treatment (steroid cream), indication, operative management carried out, daycase or inpatient cases, and histological analysis.

Results

198 patients (mean age 8.7, range 2-16) underwent foreskin procedures in the set time frame. 98.9% were referred from GP surgery, and the remainder directly from A&E. 29.8% had documented trials of steroid creams prior to surgery. 51.5% of procedures were performed for ‘non-retractile foreskin’ and 11.6% for pathological phimosis. 87.4% of patients underwent circumcision and 11.1% had freeing of adhesions. All of procedures were performed as day-case. Histology was sent for 17.3% of circumcisions, with non-specific inflammation being the most common finding (46.7%), followed by lichen sclerosus (40%).

Conclusions

In our series large number of foreskin procedures were carried out over a 12-month period with a minority for the only absolute indication of pathological phimosis We have introduced stringent guidelines in the department since this audit, which will prevent circumcision in children who may otherwise avoid surgery.

Exploration of Nanoethosomal Transgel of Naproxen Sodium for the Treatment of Arthritis

BACKGROUND

The present work aimed to develop an ethosomal gel of naproxen sodium for the amelioration of rheumatoid arthritis.

OBJECTIVE

In the present work, we have explored the potential of ethosomes to deliver naproxen into deeper skin strata. Further, the anti-inflammatory efficacy of naproxen ethosomal formulation was assessed using the carrageenan-induced rat paw edema model.

METHODS

Naproxen sodium nanoethosomes were prepared using different proportions of lipoid S100 (50mg-200mg), ethanol (20-50%) and water, and were further characterized on the basis of vesicle morphology, entrapment efficiency, zeta potential, in-vitro drug release and ex-vivo permeation studies.

RESULTS

The optimized ethosomal formulation was found to have 129 ± 0.01 nm particle size, 0.295 Polydispersity Index (PDI), -3.29 mV zeta potential, 88% entrapment efficiency and 96.573% drug release in 24 hours. TEM and SEM analysis of the optimized formulation showed slightly smooth spherical structures. The Confocal laser scanning microscopy showed that ethosomes could easily infiltrate into deeper dermal layers (upto 104.9μm) whereas the hydroalcoholic solution of the drug could penetrate up to 74.9μm. Further, the optimized ethosomal formulation was incorporated into 1% carbopol 934 gel base and optimized wherein the transdermal flux was found to be approximately 10 times more than the hydroethanolic solution. Also, the in-vivo pharmacodynamic study of the optimized ethosomal gel exhibited a higher percentage inhibition of swelling paw edema than marketed diclofenac gel.

CONCLUSION

The ethosomal gel was successfully developed and has shown the potential to be a good option for the replacement of conventional therapies of rheumatoid arthritis.

Phylogeny and comparative modeling of phytochelatin synthase from Chlorella sp. as an efficient bioagent for detoxification of heavy metals

Phytochelatins (PCs) found extensively in algae and plants are important for detoxification of heavy metals from soil and wastewater, and their synthesis is mediated by an enzyme phytochelatin synthase (PCS). In this study, a phylogram was generated to study evolutionary relationships of PCS from various organisms. It was revealed that PCS from green algae and plants are orthologs as both have evolved from a common ancestor. PCS from cyanobacteria appeared in two different clades showing that they have followed different lineages during evolution. Structural modeling was also carried out by building a 3D model of PCS from Chlorella variabilis using software Modeller v9.16. The predicted structure will be helpful for protein engineering strategies and to understand its interactions with other proteins. The biological biosorption capacity of Chlorella vulgaris (a green alga) was determined to remove Cd, Cu and Pb from industrial effluents. The biosorption of three heavy metals from industrial waste water was investigated under various conditions like pH, biomass concentration, contact time and temperature. Bio-removal of heavy metals was carried out by exposing culture of C. vulgaris to water samples of different heavy metal concentrations. The decrease in Cd, Cu and Pb quantities after 1 to 7 days of incubation period were 83%, 84% and 82.5%, respectively. In view of this, Chlorella spp. could be used on a large scale to detoxify heavy metals and clean up contaminated environments.

An insight into nutritional profile of selected Pleurotus species

The global demand for good quality food indicates that consumers are more concerned about a particular diet associated with good health and lower risk for certain ailments. Mushrooms are widely used as healthy nutritious food. In the present study, the nutritional composition of four different Pleurotus sp. was determined. Prior to extraction, all the selected mushrooms were subjected for proximate composition analysis. The protein, fat, ash, total carbohydrate, fiber and energy contents were in the range of (16.07- 25.15%), (0.64-2.02%), (2.1-9.14%), (65.66-82.47%), (6.21-54.12%) and (342.20-394.30Kcal/100g), respectively. The spectrophotometric analysis showed that the concentration of protein was in the range of 45.78-33.47 mg/g in all Pleurotus sp. High performance liquid chromatographic analysis of sugars showed six different mono and disaccharides in all the selected mushrooms. The fatty acid profile by gas chromatography-mass spectrometry revealed that the main fatty acids in selected mushrooms were present in the order linoliec acid> oleic acid> palmitic acid. The results suggested that all the Pleurotus sp. could be considered as a rich source of nutrients.

Effect of rhubarb (Rheum emodi) in primary dysmenorrhoea: a single-blind randomized controlled trial

BACKGROUND

The aim of this study was to investigate and evaluate the efficacy of Rheum emodi in the management of primary dysmenorrhoea.

METHODS

A randomized, single-blind, standard controlled trial compared efficacy of R. emodi against mefenamic acid on diagnosed subjects of primary dysmenorrhoea for three consecutive cycles. Experimental group (n=30) received capsules of R. emodi powder two times a day, two days before the expected date of menstruation, and continued first three days of menstruation, while control group (n=15) participants received mefenamic acid capsules three times a day on the same protocol. The primary outcome measures were reduced in severity and duration of pain, assessed by visual analogue scale (VAS) and verbal multidimensional scoring system (VMSS), and secondary outcome measures were overall improvement of dysmenorrhoea and improved in quality of life (QOL). Statistical analysis was done by repeated measures analysis of variance and Chi-square/Fisher Exact test.

RESULTS

The menstrual pain was significantly decreased in both groups after three-cycle intervention. Significant changes were observed in VAS (p<0.001) and VMSS (p<0.001) in the experimental group. There is a significant (p<0.001) reduction in duration of pain in both the groups. Associated symptoms and QOL were markedly improved after treatment (p<0.001).

CONCLUSIONS

It has been clear from the above result that R. emodi is an effective herb in alleviating symptoms of primary dysmenorrhoea. It can serve as an alternative treatment without any apparent side effects. These results deserve further investigations.

Efficacy of flexible ureteroscopy and laser lithotripsy for lower pole renal calculi

Objective:

Our aim was to determine whether flexible ureterorenoscopy and laser lithotripsy is efficacious and safe in treating lower pole renal calculi.

Materials and methods:

Patient, procedure and stone data of patients who underwent flexible ureterorenoscopy and laser lithotripsy at our referral centre were collected prospectively between November 2005 and November 2011 and entered into a designated database. In all, 242 procedures were performed in 198 patients.

Results:

The mean age was 51.2 years. The mean calculi size was 10.51 mm (range 4–27 mm). Thirty seven patients had more than one stone in the lower pole. An access sheath was used in 19 patients (9.6%), 171 (86.4%) had a ureteric stent inserted after the procedure, and 165 patients had a single procedure. Re-operation rate was 16.7%. Stone-free rates after one procedure were 89%, 80% and 41%, respectively, for calculi measuring 4–10 mm ( n=107), 11–20 mm ( n=76) and > 20 mm ( n=15). The overall stone-free rate was 83%, 91% and 95% after one, two and three procedures, respectively.

Conclusion:

Flexible ureterorenoscopy and laser lithotripsy is a safe and effective minimally invasive treatment option for patients with 4–20 mm lower pole calculi. Staged procedures, however, become necessary as the size of the stone increases greater than 20 mm, and this should be mentioned when counselling patients for their primary procedure.

Evaluation of the pressure leak test in increasing the lifespan of flexible ureteroscopes

INTRODUCTION

Flexible ureteroscopes are expensive and delicate instruments that are integral in the offering of a minimally invasive technique of diagnosis and treatment of urolithiasis. Published literature has identified the importance of early damage recognition in preventing frequent use of the scope that would lead to further damage and high repair and replacement costs. Our study was designed to examine the outcome of the pressure leak test on the condition of flexible ureteroscopes after every use and analysing the damage and costs of maintenance.

PATIENTS AND METHODS

A prospective study was designed with two treatment groups. Group 1, 95 consecutive procedures (n = 95) of flexible ureterorenoscopy and laser fragmentation of renal calculi were performed with ACMI DUR 8, (a scope with no in-built leak test facility). This was compared against group 2, where 98 procedures of laser fragmentation of renal calculi (n = 98) were performed using Storz Flex X(2) Ureteroscopes (with a in-built leak test facility). All scopes in Group 2 were tested for pressure leak after every procedure and the outcome of the tests recorded.

RESULTS

Both groups were comparable for grade of surgeon; stone location, size & number; access sheath usage and duration of lasering. In Group 1, there were seven scope damages resulting in repairs/replacement amounting to costs $46264.40 (7.1% damage). In Group 2, three scopes revealed a positive pressure leak test, implying damage with repair costs of $9952.80 (3.1% damage) (p < 0.05). Significant cost savings and reduction in downtime were made in Group 2.

CONCLUSIONS

Pressure leak testing following flexible ureterorenoscopy helped to significantly control costs of maintenance and repair. Newer scopes should have a leak testing mechanism as it prevents further detrimental damage to the scope, build-up of repair costs are avoided and there is an increase in the longevity of these delicate instruments.

Cytoarchitecture, areas, and neuron numbers of the Etruscan shrew cortex

The Etruscan shrew, Suncus etruscus, is one of the smallest mammals. Etruscan shrews can recognize prey shape with amazing speed and accuracy, based on whisker-mediated tactile cues. Because of its small size, quantitative analysis of the Etruscan shrew cortex is more tractable than in other animals. To quantitatively assess the anatomy of the Etruscan shrew's brain, we sectioned brains and applied Nissl staining and NeuN (neuronal nuclei) antibody staining. On the basis of these stains, we estimated the number of neurons of 10 cortical hemispheres by using Stereoinvestigator and Neurolucida (MBF Bioscience) software. On average, the neuron number per hemisphere was found to be ~1 million. We also measured cortical surface area and found an average of 11.1 mm² (n = 7) and an average volume of 5.3 mm³ (n = 10) per hemisphere. We identified 13 cortical regions by cytoarchitectonic boundaries in coronal, sagittal, and tangential sections processed for Nissl substance, myelin, cytochrome oxidase, ionic zinc, neurofilaments, and vesicular glutamate transporter 2 (VGluT2). The Etruscan shrew is a highly tactile animal with a large somatosensory cortex, which contains a barrel field, but the barrels are much less clearly defined than in rodents. The anatomically derived cortical partitioning scheme roughly corresponds to physiologically derived maps of neocortical sensory areas.

Towards excimer-laser-based stereolithography: a rapid process to fabricate rigid biodegradable photopolymer scaffolds

We demonstrate high-resolution photocross-linking of biodegradable poly(propylene fumarate) (PPF) and diethyl fumarate (DEF) using UV excimer laser photocuring at 308 nm. The curing depth can be tuned in a micrometre range by adjusting the total energy dose (total fluence). Young's moduli of the scaffolds are found to be a few gigapascal, high enough to support bone formation. The results presented here demonstrate that the proposed technique is an excellent tool for the fabrication of stiff and biocompatible structures on a micrometre scale with defined patterns of high resolution in all three spatial dimensions. Using UV laser photocuring at 308 nm will significantly improve the speed of rapid prototyping of biocompatible and biodegradable polymer scaffolds and enables its production in a few seconds, providing high lateral and horizontal resolution. This short timescale is indeed a tremendous asset that will enable a more efficient translation of technology to clinical applications. Preliminary cell tests proved that PPF : DEF scaffolds produced by excimer laser photocuring are biocompatible and, therefore, are promising candidates to be applied in tissue engineering and regenerative medicine.

Tactile experience shapes prey-capture behavior in Etruscan shrews

A crucial role of tactile experience for the maturation of neural response properties in the somatosensory system is well established, but little is known about the role of tactile experience in the development of tactile behaviors. Here we study how tactile experience affects prey capture behavior in Etruscan shrews, Suncus etruscus. Prey capture in adult shrews is a high-speed behavior that relies on precise attacks guided by tactile Gestalt cues. We studied the role of tactile experience by three different approaches. First, we analyzed the hunting skills of young shrews' right after weaning. We found that prey capture in young animals in most, but not all, aspects is similar to that of adults. Second, we performed whisker trimming for 3–4 weeks after birth. Such deprivation resulted in a lasting disruption of prey capture even after whisker re-growth: attacks lacked precise targeting and had a lower success rate. Third, we presented adult shrews with an entirely novel prey species, the giant cockroach. The shape of this roach is very different from the shrew's normal (cricket) prey and the thorax—the preferred point of attack in crickets—is protected by a heavy cuticle. Initially shrews attacked giant roaches the same way they attack crickets and targeted the thoracic region. With progressive experience, however, shrews adopted a new attack strategy targeting legs and underside of the roaches while avoiding other body parts. Speed and efficiency of attacks improved. These data suggest that tactile experience shapes prey capture behavior.

The neurobiology of Etruscan shrew active touch

The Etruscan shrew, Suncus etruscus, is not only the smallest terrestrial mammal, but also one of the fastest and most tactile hunters described to date. The shrew's skeletal muscle consists entirely of fast-twitch types and lacks slow fibres. Etruscan shrews detect, overwhelm, and kill insect prey in large numbers in darkness. The cricket prey is exquisitely mechanosensitive and fast-moving, and is as big as the shrew itself. Experiments with prey replica show that shape cues are both necessary and sufficient for evoking attacks. Shrew attacks are whisker guided by motion- and size-invariant Gestalt-like prey representations. Shrews often attack their prey prior to any signs of evasive manoeuvres. Shrews whisk at frequencies of approximately 14 Hz and can react with latencies as short as 25-30 ms to prey movement. The speed of attacks suggests that shrews identify and classify prey with a single touch. Large parts of the shrew's brain respond to vibrissal touch, which is represented in at least four cortical areas comprising collectively about a third of the cortical volume. Etruscan shrews can enter a torpid state and reduce their body temperature; we observed that cortical response latencies become two to three times longer when body temperature drops from 36°C to 24°C, suggesting that endothermy contributes to the animal's high-speed sensorimotor performance. We argue that small size, high-speed behaviour and extreme dependence on touch are not coincidental, but reflect an evolutionary strategy, in which the metabolic costs of small body size are outweighed by the advantages of being a short-range high-speed touch and kill predator.

Cortical organization in the Etruscan shrew (Suncus etruscus)

Cortical organization in the Etruscan shrew is of comparative interest because of its small size and because the Etruscan shrew is an amazing tactile hunter. Here we investigated cortical organization in Etruscan shrews by electrophysiological mapping. We developed an anesthesia protocol for this very small mammal in which we combined massive application of local anesthesia, very slow induction of general anesthesia, and passive cooling. Under this anesthesia regime, we characterized auditory, visual, and somatosensory cortical responses. We found that large parts of shrew cortex respond to such stimuli. Of the responsive sites, a small fraction (∼14%) responded to visual stimuli in a caudally located region. Another small fraction of sites (∼11%) responded to auditory stimuli in a centrally located region. The majority of sites (∼75%) responded to tactile stimuli. We identified two topographically organized somatosensory areas with small receptive fields referred to as putative primary somatosensory cortex and putative secondary somatosensory cortex. In a posterior-lateral region that partially overlaps with piriform cortex, we observed large somatosensory receptive fields and often polysensory responses. In an anterior-lateral region that partially overlaps with piriform cortex, we observed large unimodal somatosensory receptive fields. Our findings demonstrate a remarkable degree of tactile specialization in Etruscan shrew cortex.

Tubular ectasia of the rete testis: a diagnostic dilemma

Tubular ectasia of the rete testis is a pathologically benign process with complex and varied aetiology. It must be differentiated from neoplastic disease of the testis clinically with patient age, mode of presentation, tumour marker status and the characteristic ultrasound and Doppler study findings. Awareness and diagnosis of this clinical entity can prevent unnecessary surgical intervention in these patients.

Tactile guidance of prey capture in Etruscan shrews

Whereas visuomotor behaviors and visual object recognition have been studied in detail, we know relatively little about tactile object representations. We investigate a new model system for the tactile guidance of behavior, namely prey (cricket) capture by one of the smallest mammals, the Etruscan shrew, Suncus etruscus. Because of their high metabolic rate and nocturnal lifestyle, Etruscan shrews are forced to detect, overwhelm, and kill prey in large numbers in darkness. Crickets are exquisitely mechanosensitive, fast-moving prey, almost as big as the shrew itself. Shrews succeed in hunting by lateralized, precise, and fast attacks. Removal experiments demonstrate that both macrovibrissae and microvibrissae are required for prey capture, with the macrovibrissae being involved in attack targeting. Experiments with artificial prey replica show that tactile shape cues are both necessary and sufficient for evoking attacks. Prey representations are motion- and size-invariant. Shrews distinguish and memorize prey features. Corrective maneuvers and cricket shape manipulation experiments indicate that shrew behavior is guided by Gestalt-like prey descriptions. Thus, tactile object recognition in Etruscan shrews shares characteristics of human visual object recognition, but it proceeds faster and occurs in a 20,000-times-smaller brain.

Compatibility of osmolytes with Gibbs energy of stabilization of proteins

This study led to the conclusion that naturally occurring osmolytes which are known to protect proteins against denaturing stresses, do not perturb the Gibbs energy of stabilization of proteins at 25 degrees C (DeltaG(D) degrees ) which has been shown to control the in vivo rate of degradative protein turnover (Pace et al., Acta Biol. Med. Germ 40 (1981) 1385-1392). This conclusion has been reached from our studies of heat-induced denaturation of lysozyme, ribonuclease A, cytochrome c and myoglobin in the presence of different concentrations of osmolytes, namely, glycine, proline, sarcosine and glycine-betaine. At a fixed concentration of osmolyte a heat-induced denaturation curve measured by following changes in the molar absorption coefficient of the protein, was analyzed for T(m), the midpoint of the denaturation and DeltaH(m), the enthalpy change of denaturation at T(m). Values of DeltaG(D) degrees were determined with Gibbs-Helmoltz equation using known values of T(m), DeltaH(m) and DeltaC(p), the constant-pressure heat capacity change. It has been observed that T(m) increases with the osmolyte concentration, whereas DeltaG(D) degrees remains unaffected in the presence of the osmolyte. This observation on DeltaG(D) degrees in the presence of osmolytes has been considered in the physiological context.

Spontaneous hemobilia in a hemophiliac treated by factor VIII replacement and nasobiliary drainage

We report a case of spontaneous hemobilia in a hemophilia patient presenting with classical Sandblom's triad of symptoms. Endoscopic retrograde cholangiography was helpful in establishing the diagnosis. Hemobilia subsided with factor VIII replacement and endoscopic nasobiliary drainage. Endoscopic nasobiliary drainage resulted in lysis of the clots in the biliary tree and relief of obstructive jaundice.

Role of non-compatible osmolytes in the stabilization of proteins during heat stress

This study is a systematic attempt to understand the roles of non-compatible osmolytes, i.e. solutes that have inhibitory effects on enzymes, in the stabilization of proteins against denaturing stress. Thermal denaturation of RNase A, holo-alpha-lactalbumin, apo-alpha-lactalbumin, lysozyme and metmyoglobin in the absence and presence of various concentrations of free basic amino acids was studied by observing changes in the absorption coefficients of these proteins. It has been observed that arginine and histidine destabilize all proteins in terms of the midpoint of the transition curve and Gibbs energy change on denaturation. Study of the heat-induced denaturation of the proteins in the presence of various concentrations of arginine at different pH values demonstrated that arginine binds to the denatured molecules. In contrast with the effect of arginine and histidine on protein stability, it was observed that the effect of lysine on proteins stability is unpredictable, i.e. it may have a stabilizing effect, no effect or a destabilizing effect on proteins during denaturing stress. The results of this study are considered from an evolutionary perspective.

Sublethal effects of hexavalent chromium on the body growth rate and liver function enzymes of phenobarbitone-pretreated and promethazine-pretreated rabbits

Hepatotoxic effects of chromium have been studied on the liver function enzymes of male New Zealand white rabbits, Oryctolagus cuniculus, with and without pretreatment with phenobarbitone (PB) and promethazine (PM). The total body weight was decreased under all experimental conditions. After PB administration (5 mg/kg body wt/day for 5 days), the serum glutamate oxaloacetate transaminase (GOT), glutamate pyruvate transaminase (GPT), lactate dehydrogenase (LDH), and isocitrate dehydrogenase (ICDH) activities decreased 21%, 65%, 25%, and 37%, respectively, whereas the alkaline phosphatase (AP) activity increased 70%. After PM treatment (5 mg/kg body wt/day for 5 days) the serum GPT was inhibited 73%, whereas LDH activity was increased 37%. The hepatic GPT and AP activities decreased after PB (52% and 31%, respectively), and PM (48% and 44%, respectively) treatments, whereas the activities of LDH and ICDH increased (after PB: 817% and 109%, respectively, and after PM: 136% and 44%, respectively). Potassium dichromate, administered at a dose of 8 mg/kg body wt/day for 5 days, decreased serum GOT (44%), GPT (61%), LDH (63%), and AP (44%) activities. The hepatic GOT, GPT and AP activities were likewise decreased (86%, 51%, and 46%, respectively), whereas hepatic LDH and ICDH activities increased 667% and 193%, respectively. When administered to PB-pretreated animals, the serum GOT and AP activities were decreased (50% and 68%), whereas ICDH was increased (29%). The hepatic GOT, LDH, and ICDH activities increased 79%, 221%, and 130%, respectively. In the PM-pretreated animals, the chromium treatment inhibited the activities of serum GOT (48%), GPT (44%), and LDH (43%). The hepatic GPT, LDH, and ICDH activities increased 90%, 133%, and 52%, respectively.

Effect of hexavalent chromium on drug-metabolizing enzymes in male domesticated rabbits

We studied the effect of chromium on the drug-metabolizing enzymes (DME) in male New Zealand white rabbits, Oryctolagus cuniculus, with and without pretreatment with phenobarbitone (PB) and promethazine (PM). The activities of cytochrome P-450 (183%), aniline hydroxylase (ANH, 265%), acetanilide hydroxylase (ACH, 160%), benzphetamine demethylase (BD, 112%), aminopyrine demethylase (AD, 97%), N,N,-dimethyl aniline demethylase (DAD, 72%), and cytochrome-c-reductase (100%) were increased after PB treatment. The activities of cytochrome b5 and N,N,-dimethyl aniline N-oxide (DAO) were, however, decreased 79% and 47%, respectively. Most of the DME remained unaffected after PM treatment except for the increase in ANH (55%), ACH (56%), and BD (16%). Potassium dichromate administered to rabbits at a dose of 8 mg/kg body weight/day for 5 days resulted in an increase in the activities of ANH (108%), BD (76%), AD (25%), and DAD (49%), while that of cytochrome b5 and DAO were inhibited 81 and 77%, respectively. There was no effect on the activities of cytochrome P-450, ACH, and cytochrome-c-reductase. Chromium, administered to PB-pretreated animals decreased the activities of ANH (41%), ACH (35%), BD (34%), AD (30%), DAD (51%), cytochrome-c-reductase (72%), and DAO (62%). Other enzymes remained unaffected. When administered to PM-pretreated animals, the activities of ANH, BD, AD, and DAD increased 34, 69, 24 and 54%, respectively, whereas activities of cytochrome b5 and DAO were decreased 96 and 68%, respectively. All other DME remained unaffected.

An assessment of cadmium toxicity on cytochrome P-450 and flavin monooxygenase-mediated metabolic pathways of dimethylaniline in male rabbits

Cadmium is an environmental pollutant and its effect on the in vitro metabolism of N,N-dimethylaniline (DMA) using male rabbits was investigated. Activities of cytochrome P-450 and FMO-dependent monooxygenases were studied using hepatic microsomes. Following CdCl2 (i.p.) administration (6 mg/kg/day for 6 days), both DMA-N-oxidation and DMA-N-demethylation decreased by 86%. The effects of CdCl2 on the phenobarbitone (PB)-induced form of P-450 were also studied. Intraperitoneal pretreatment of rabbits with PB (5 mg/kg/day for 5 days) increased N-demethylation by 82%, while N-oxidation decreased by 49%. Both reactions decreased significantly on additional treatment with CdCl2. Promethazine (5 mg/kg/day for 5 days) did not produce any change in the activities of either enzyme. The enzymes remained unaffected by CdCl2 treatment in promethazine-pretreated animals thus confirming its role as a hepatoprotective agent.

Effect of dimethoate on hepatic cytochrome P-450 and glutathione S-transferase activity in pigeon and rat

Effect of acute exposure (24 hr) to different oral doses of dimethoate on hepatic microsomal cytochrome P-450 (Cyt. P-450) content and cytosolic glutathione S-transferase (GST) activity were determined in pigeon and rat to ascertain difference in the metabolic response as a measure of species selective toxicity. Dimethoate at five different doses caused a statistically significant decrease in Cyt. P-450 content both in pigeon and rat. However, reduction in GST activity was significant at three doses in pigeon and at high dose in rat. Thus, a different quantum of hepatic Cyt. P-450 decrease and a differed response of GST activity against dimethoate exposure in pigeon and rat may be one of the possible causes for relatively higher toxicity of dimethoate in birds.

Acute toxicity and anti acetylcholinesterase potential of some biphenyl derivatives to non target species

Five newly synthesised biphenyl derivatives were evaluated for their acute contact toxicity (LC50) against rice weevil and honey bee and anti acetylcholinesterase potential (I50) against honey bee, fish, pigeon and rat. Amongst, O,O-dimethyl-O, p-Nitro-biphenyl phosphate was most potent against rice weevil, whereas p-(4-Nitrophenyl) phenyl-N-methyl carbamate against honey bee. Based on I50 values the biphenyl derivatives of phosphoric acid esters were more potent anti acetylcholinesterase (AChE) agents against rat and fish brain AChE while derivative of carbamic esters towards pigeon brain AChE. The anti AChE potency of both groups appear to be of the same order towards bee head AChE.