Effect of Di-(2-ethylhexyl) Phthalate on Rat Liver Injured by Chronic Carbon Tetrachloride Treatment

Abstract The effect of Di-(2-ethylhexyl) phthalate (DEHP), a widely used plasticizer, was studied using histopathological and biochemical parameters on rat liver injured by carbon tetrachloride (CCl₄). The mild centrilobular necrosis observed with CCl₄ (7.7 mmol/kg subcutaneously and biweekly up to 38 days) and mild congestion and bile duct proliferation produced by DEHP (2.5 mmol/kg intraperitoneally daily for ten days after the day 28 of experiment) were modified into extensive necrosis of the parenchymal cells when the animals received both chemicals. Groups of hepatocytes mostly at the periphery of the lobules also showed coagulative necrosis and some central and portal veins were completely occluded. Alterations in the activity of serum and liver enzymes of the animals receiving both chemicals were not significantly different from those treated with CCL alone, except in case of glucose-6-phosphatase (G-6-Pase) and SGPT. The characteristic decrease of G-6-Pase and increase of SGPT was less marked. Although the exact mechanism of the chemical interaction between CCl₄ and DEHP is not known, the results indicate their combined toxic potentiality.     

Long-term followup of patients after redo bladder neck reconstruction for bladder exstrophy complex

PURPOSE: The aim of this study was to determine whether redo bladder neck reconstruction is effective in achieving continence after a failed bladder neck reconstruction procedure. MATERIALS AND METHODS: We retrospectively reviewed the hospital records of patients with bladder exstrophy who had undergone redo bladder neck reconstruction. There were 30 patients in the study, including 20 boys and 10 girls. Mean patient age at redo bladder neck reconstruction was 9.3 years (range 3.2 to 15.5). The patients were divided into 3 groups on the basis of the preoperative pattern of incontinence--incomplete wetters, complete wetters and those on continuous suprapubic drainage. Of the patients 15 already had undergone bladder augmentation, 12 had undergone a Mitrofanoff procedure and 12 had been treated with bulking agents injected in the bladder neck in an attempt to achieve continence. Four patients had undergone more than 1 bladder neck procedure. The patients were investigated with a combination of noninvasive urodynamics, cystoscopy, cystogram and ultrasound. All patients underwent Mitchell's modification of Young-Dees-Leadbetter bladder neck reconstruction. Additional procedures performed included augmentation cystoplasty and Mitrofanoff formation. RESULTS: Mean followup was 6.9 years (range 1.2 to 15.5). Postoperatively 28 patients were using clean intermittent catheterization to empty the bladder (5 per urethra, 23 via Mitrofanoff). Two patients remained on continuous suprapubic catheter drainage. A total of 18 patients (60%) were dry postoperatively (80% of girls and 50% of boys). Among dry patients only 3 were performing clean intermittent catheterization per urethra and 15 via a Mitrofanoff channel. No patient was able to void per urethra without the need for clean intermittent catheterization. The 2 patients on continuous suprapubic catheter drainage continued to remain so. At night only 50% of the patients were dry (5 on free drainage, 4 on clean intermittent catheterization, 6 not on any drainage). Those patients who did not respond satisfactorily to redo bladder neck reconstruction underwent subsequent additional procedures, which included injection of bulking agents (3 patients), insertion of an artificial urinary sphincter (1), Mitrofanoff formation (2) and bladder augmentation plus Mitrofanoff channel (1). Postoperative complications included difficulty with clean intermittent catheterization (8 patients), perivesical leak (1), recurrent epididymo-orchitis (1), upper urinary tract dilatation (2) and incisional hernia (1). Bladder neck closure was being considered in 5 patients. CONCLUSIONS: In our experience redo bladder neck reconstruction cannot achieve continence with volitional voiding per urethra. Although redo bladder neck reconstruction can render a significant number of patients dry, it is only effective if performed in conjunction with augmentation. Failure of the initial bladder neck reconstruction may be a reflection of a bladder that is of inadequate capacity and/or compliance. Therefore, bladder augmentation should be considered in all patients requiring redo bladder neck reconstruction. Bladder neck closure may be a better alternative to redo bladder neck reconstruction.     

Profile of Kangari cancer: a prospective study

Kangari, an earthenware brazier containing burning charcoal, is used for personal warming during the winter months by most of the people in Kashmir valley. Kangari is usually held close to the lower abdomen or in between the legs while squatting on the ground. The use of kangari is associated with development of skin cancer at the sites of prolonged exposure. In the present study 43 patients with Kangari cancer were analyzed prospectively with the objective of understanding their clinico-pathological profile and the response to various treatment modalities. Variables such as age, gender, grade, site of lesion etc., were evaluated for their prognostic significance.     

Eukaryotic arylamine N-acetyltransferase. Investigation of substrate specificity by high-throughput screening

Arylamine N-acetyltransferases (NAT; EC 2.3.1.5) catalyse the transfer of acetyl groups from acetylCoA to xenobiotics, including drugs and carcinogens. The enzyme is found extensively in both eukaryotes and prokaryotes, yet the endogenous roles of NATs are still unclear. In order to study the properties of eukaryotic NATs, high-throughput substrate and inhibitor screens have been developed using pure soluble recombinant Syrian hamster NAT2 (shNAT2) protein. The assay can be used with a wide range of compounds and was used to determine substrate specificity of shNAT2. We describe the expression and characterisation of shNAT2 and also purified recombinant human NAT1 and NAT2, including the use of the assay to explore the substrate specificities of each of the enzymes. Hamster NAT2 has similar substrate specificity to human NAT1, acetylating para-aminobenzoate but not arylhydrazine and hydralazine compounds. The overlapping but distinct substrate-specific activity profiles of human NAT1 and NAT2 were clearly observed from the screen. Naturally occurring compounds were tested as substrates or inhibitors of shNAT2 and succinylCoA was found to be a potent inhibitor of shNAT2.     

Morbidly adherent placenta: can we limit the aftermath?

Morbidly adherent placenta is a grave complication of pregnancy referring to a pathological adherence of placenta to uterine wall with a reported incidence of 1:2500 deliveries. Women with previous two caesarean sections and placenta previa are at greater risk and also those with previous damage to uterine wall. This commentary discusses the pathophysiology, diagnosis and management of the condition in local perspective.     

Gallbladder intestinal metaplasia in Pakistani patients with gallstones

The gallbladder specimens of patients who underwent cholecystectomy for symptomatic gallstones between 2003 and 2005 were evaluated for the presence of Intestinal Metaplasia. (IM) and its risk factors. IM was positive in 39% of 293 patients tested, and in the comparative analysis of 114 metaplasia positive versus 179 negative patients, a high risk was found in patients who were 60 years or older [adjusted odds ratio (aOR) = 3.0, 95% confidence interval (CI): 1.5, 6.2]. Other factors with aOR greater than 1 were moderate to excessive use of chilies (1.8) and ethnic origin of North India (1.7). Screening method has yet to be devised for early detection of gallbladder cancer by identifying metaplastic lesions early in life. We believe that large geographic variation and lifestyle environmental factors associated with the development of gallbladder metaplasia and cancer mortality are concealed in our study that needs to be further explored.     

Natriuretic peptides as therapy in cardiac ischaemia/reperfusion

Natriuretic peptides elicit vasodilation, increased sodium excretion and concomitant diuresis, and counteract the RAAS. In the heart itself, natriuretic peptides may also act anti-inflammatory and antifibrotic. This has led to the pursuit of natriuretic peptides and chemically modified peptides as adjunctive therapy in myocardial ischaemia. However, natriuretic peptide infusion may also influence the endogenous natriuretic peptide response and lipid accumulation. We hypothesised that a) natriuretic peptide infusion (BNP and CD-NP) is cardiomyocyte protective, b) affects the endogenous response, and c) facilitate cardiac lipid accumulation. We examined these effects in a minimally invasive porcine model of regional cardiac ischaemia and reperfusion. The studies were supplemented by a 48-hour porcine model of ischemia and reperfusion as well as an in vitro study of BNP administered in a HL-1 cell model of "ischaemia/reperfusion". Infarct size was determined by TTC staining, plasma troponin T release, and total RNA integrity in cardiac tissue samples. The endogenous response was assessed by a processing-independent proANP immunoassay and mRNA quantitation. Lipids in plasma and myocardial tissue were determined by TLC. The studies show that natriuretic peptides decrease cardiomyocyte damage, possibly partly through indirect mechanisms. Furthermore, BNP infusion completely inverts the endogenous response, whereas CD-NP infusion does not. Finally, both natriuretic peptides increase plasma free fatty acids, which is associated with an increased cardiac lipid accumulation in non-ischaemic myocardium. In conclusion, the studies suggest that natriuretic peptides are beneficial in terms of reduced cardiac injury. In addition, the endogenous natriuretic peptide response is inverted. The results advocate for pursuing natriuretic peptide treatment in ischaemia/reperfusion damage. However, the metabolic consequences in a cardiac tissue challenged by ischaemia should be pursued before testing the peptides in patients.