Comparative evaluation of antibacterial efficacy different bioactive smart composites: An in vitro study

BACKGROUND

Composites are the widely used restorative materials, and over the year, newer restorative composites have been introduced to eliminate the drawbacks of previous ones. The recent advance in restorative dentistry is bioactive restorative materials. However, bacterial plaque formation on these restorations is the primary reason for secondary caries.

AIMS AND OBJECTIVES

The purpose of this study was to do the comparative evaluation of bioactive restorative composites (Beautifil Flow Plus, Activa BioACTIVE, and Filtek Z250 XT as control) for their antibacterial efficacy under in vitro conditions.

MATERIALS AND METHOD

Thirty material blocks were used for this evaluation. Antibacterial efficacy was checked against Streptococcus mutans and observed under confocal laser scanning microscopy.

RESULTS

The results showed that Activa BioACTIVE shows maximum number of dead bacteria on the material surface compared to other groups.

CONCLUSION

It can be concluded as it has maximum antibacterial efficacy among tested materials.

Impact of GSTM1, GSTT1 and GSTP1 gene polymorphism and risk of ARV-associated hepatotoxicity in HIV-infected individuals and its modulation

Glutathione S-transferase (GST) family is involved in a two-stage detoxification process of a wide range of environmental toxins, carcinogen and antiretroviral (ARV) therapy (ART) drugs. The aim of this study is to describe the impact of genetic polymorphisms of GSTM1, GSTT1 and GSTP1-313A/G in the risk of ARV-associated hepatotoxicity in HIV-infected individuals and its modulation in hepatotoxic patients. We enrolled a total of 34 patients with hepatotoxicity, 131 HIV-infected individuals without hepatotoxicity under non-nucleoside reverse transcriptase inhibitor containing ART and 153 unrelated healthy individuals. With a case-control design, polymorphisms of GSTM1, GSTT1 and GSTP1-313A/G gene were genotyped by PCR and restriction enzyme-length polymorphism. Genotypes of GSTT1 null were significantly higher in HIV-infected individuals as compared with healthy controls (P=0.01, odds ratio (OR)=1.54). HIV-infected individuals with GSTM1-null genotype showed higher risk (P=0.09, OR=1.37) for hepatotoxicity, but risk was not significant. On evaluating gene-gene interaction models, GSTM1 null and GSTT1 null showed significant association with the risk of hepatotoxicity in HIV-infected individuals (P=0.004, OR=2.67) owing to synergistic effect of these genes. Individuals with GSTT1-null and GSTM1-null genotypes showed higher risk of hepatotoxicity with advanced stage of (CD4<200) of HIV infection (P=0.18, OR=1.39; P=0.63, OR=1.13). In case-only analysis, GSTT1-null genotype among alcohol users showed elevated risk of hepatotoxicity in HIV-infected individuals (P=0.12, OR=1.36, 95% confidence interval (CI): 0.94-1.97) as compared with GSTT1 genotypes. The carriers GSTM1-null+GSTT1-null genotype among nevirapine user showed prominent risk of hepatotoxicity in HIV-infected individuals (P=0.12, OR=4.21, 95% CI: 0.60-29.54). Hence, we can conclude that GSTT1-null and GSTM1-null genotypes alone and in combination may predict the acquisition of hepatotoxicity.

Use of continuous positive airway pressure during spinal anaesthesia in a patient with severe chronic obstructive pulmonary disease

We report the case of a patient with severe chronic obstructive pulmonary disease who underwent local resection of a carcinoma of the rectum under spinal anaesthesia. Although the patient was keen to avoid general anaesthesia and to have the operation under a spinal anaesthetic, pre-operative assessment showed that he could not lie flat. As the surgical procedure required the patient to be in the lithotomy position, ideally with a head-down tilt, it was hoped that continuous positive airway pressure with a facemask during spinal anaesthesia might help him to tolerate the position comfortably. Continuous positive airway pressure at 7.5 cmH(2)O was successfully used to facilitate breathing during surgery under spinal anaesthesia. A combination of regional anaesthesia and continuous positive airway pressure via a facemask is easy to use and may be a useful option in the management of these challenging patients.

Peroxynitrite activates mitogen-activated protein kinase (MAPK) via a MEK-independent pathway: a role for protein kinase C

In this study we show that phosphorylation of extracellular signal-regulated kinase (ERK1/2; also known as p44/42MAPK) following peroxynitrite (ONOO(-)) exposure occurs via a MAPK kinase (MEK)-independent but PKC-dependent pathway in rat-1 fibroblasts. ONOO(-)-mediated ERK1/2 phosphorylation was not blocked by MEK inhibitors PD98059 and U0126. Furthermore, no increase in MEK phosphorylation was detected upon ONOO(-) treatment. Staurosporine was used to investigate whether protein kinase C (PKC) is involved. This was confirmed by down-regulation of PKC by phorbol-12,13-dibutyrate, which resulted in significant reduction of ERK1/2 phosphorylation by ONOO(-), implying that activation of ERK by ONOO(-) depends on activation of PKC. Indeed, PKCalpha and epsilon were activated upon ONOO(-) exposure. When cells were treated with ONOO(-) in a calcium-free buffer, no activation of PKCalpha was detected. Concomitantly, a reduction of ERK1/2 phosphorylation was observed suggesting that calcium was required for translocation of PKCalpha and ERK phosphorylation by ONOO(-). Indeed, ONOO(-) exposure resulted in increased cytosolic calcium, which depended on the presence of extracellular calcium. Finally, data using Gö6976, an inhibitor of calcium-dependent PKC activation, implied that ONOO(-)-mediated ERK1/2 phosphorylation depends on activation of a calcium-dependent PKC.

Endoureterotomy for congenital primary obstructive megaureter: preliminary report

BACKGROUND AND PURPOSE

Congenital obstructive megaureter (COMU) may be unilateral or bilateral and may present in later years of life. If the obstruction is not relieved in good time, deleterious effects on the proximal ureter and kidney are well known. Stones may complicate the situation further. So far, the only treatment that has been available is to disconnect the ureter proximal to the site of obstruction, remove any stone, and reimplant the ureter into the bladder after any necessary tailoring. After noticing the encouraging results of endopyelotomy for congenital ureteropelvic junction obstruction, we decided to use the same principle for the management of COMU, as similar functional pathology is present in both situations.

PATIENTS AND METHODS

Our technique was applied in six ureters in five adult patients. After cystoscopic evaluation of the bladder and ureteral orifice, a guidewire was advanced up the ureter, and the lower ureter was dilated. A ureteroscope or other suitable endoscopic instrument was passed, and the obstructed segment of the ureter was incised at the 6 o'clock position with pure cutting current. All of the layers of the ureter were incised in the long axis through the entire obstructive segment, so as to expose the periureteral areolar tissue. If necessary, a similar cut was made at the 12 o'clock position. Utmost care was taken not to incise the bladder mucosa. A double-J stent was inserted for 3 weeks.

RESULTS

Follow-up for 1 to 4 years showed free drainage of urine into the bladder, with marked reduction in proximal stasis and freedom from recurrent infection and pain.

CONCLUSION

Although our series is small and follow- up is relatively short, it appears that endoureterotomy is a safe and effective treatment for COMU.

Biological control of fusarial wilt of pigeon pea by Bacillus brevis

A virulent strain of pigeon pea wilt pathogen was isolated from wilted pigeon pea plants and was identified as Fusarium oxysporum f. sp. udum. Many bacterial cultures showing antagonism to the pathogen were isolated from various ecological niches. When tested under pot and field conditions, development of fusarial wilt symptoms was prevented in pigeon pea seeds treated with one such antagonist, Bacillus brevis. A formulation of B. brevis with vermiculite as a carrier had a shelf life of at least 6 months. Bacillus brevis produced an extracellular antagonistic substance which induced swelling of the pathogen's hyphal tips, and cells were bulbous and swollen with shrunken and granulated cytoplasm. The antagonistic substance also inhibited germination of conidia, and was fungicidal to the vegetative mycelia of the pathogen. Comparison of the properties of our antagonistic substance with that of known antibiotics produced by B. brevis suggests that our antagonistic substance is a novel compound. The observations reported here indicate that this strain of B. brevis may have potential as a biocontrol agent against fusarial wilt in pigeon pea.

Insulin resistance syndrome in 8-year-old Indian children: small at birth, big at 8 years, or both?

We have studied 477 8-year-old Indian children to define the relationship between birth weight and cardiovascular risk factors, including insulin resistance syndrome (IRS) variables and plasma total and LDL cholesterol concentrations. All risk factors were strongly related to current weight. After adjustment for current weight, age, and sex, lower birth weight was associated with higher systolic blood pressure (P = 0.008), fasting plasma insulin and 32-33 split proinsulin concentrations (P = 0.08 and 0.02), glucose and insulin concentrations 30 min postglucose (P = 0.06 and 0.04), subscapular/triceps skinfold ratio (P = 0.003), and plasma total and LDL cholesterol concentrations (P = 0.002 and 0.001). Lower birth weight was associated with increased calculated insulin resistance (homeostasis model assessment [HOMA], P = 0.03), but was not related to the HOMA index of beta-cell function. The highest levels of IRS variables and total and LDL cholesterol were in children of low birth weight but high fat mass at 8 years. Taller height at 8 years predicted higher fasting plasma insulin concentrations, insulin resistance, and plasma total and LDL cholesterol concentrations. The most insulin-resistant children were those who had short parents but had themselves grown tall. Although the implications of our findings in relation to height are unclear, interventions to improve fetal growth and to control obesity in childhood are likely to be important factors in the prevention of cardiovascular disease and IRS in India.

Pediatric percutaneous nephrolithotomy: assessing impact of technical innovations on safety and efficacy

OBJECTIVES

To assess the safety and efficacy of percutaneous nephrolithotomy (PCNL) in the pediatric age group and the impact of certain technical modification on the ultimate outcome.

PATIENTS AND METHODS

We studied 45 renal units in 40 patients under 15 years of age who underwent PCNL at our institute. The average age was 9.2 years (range 11 months-15 years). There were 5 bilateral, 11 multiple, and 9 staghorn calculi. The average calculus size was 2.04 (0.9-4.5) cm. The PCNL was done with an ultrasound-guided peripheral puncture, a planned staged approach in some cases, and minimal tract dilatation with the use of a pediatric nephroscope and a specially designed slender probe for pneumatic intracorporeal lithotripsy.

RESULTS

Complete stone clearance was achieved in 41 of the 45 renal units, giving an overall clearance rate of 91%. Minor pyrexia (<100 degrees F/<2 days) was seen in 10 patients, whereas serious pyrexia was seen in 5. One patient had a prolonged leak from the nephrostomy site, which responded to double-J stenting, and one patient had a pelvic perforation with hyponatremia, which responded to conservative treatment. The average fall in hemoglobin was 1.6 g/dL, but none of the patients required blood transfusion.

CONCLUSION

We believe that our alterations in the standard technique of PCNL with the use of pediatric instruments can make it a safe and effective option in the modern management of pediatric urolithiasis.

Rhabdoid tumour of kidney. A case report

A case of rhabdoid tumour of kidney, a rare but more aggressive tumour of early childhood, is reported. The important histological, histogenetic and prognostic differences between rhabdoid and Wilm's tumour are discussed.