Volumetric and dosimetric impact of MRI in delineation of gross tumor volume of non-spinal vertebral metastases treated with stereotactic ablative radiation therapy.

PURPOSE: To investigate the Gross Tumor Volumes (GTV) and its dosimetric impact of magnetic resonance imaging (MRI) assisted contouring for non-spinal metastasis treated with stereotactic ablative body radiotherapy (SABR). MATERIAL AND METHODS: Five observer contours on CT (GTVCT) and CT+MR (GTVCT+MR) were evaluated against expert team contours (GTVEC) for 14 selected cases. Dice Similarity Index (DSC) and Geographical Miss Index (GMI) quantify observer variation. We also analyze the maximum dose (Dmax) and dose received by 0.35cc (D0.35cc) of the spinal cord (SC) for GTVCT and GTVCT+MR, where optimization parameters and priorities were unchanged. Percent rank function is also evaluated for SC doses. RESULTS: The mean DSC and GMI scores for the CT-only dataset are 0.6974 and 0.2851 and for CT+MR dataset is 0.7764 and 0.1907 respectively. Statistically, significant results were found for mean GTV volumes between GTVEC versus GTVCT and GTVCT versus GTVCT+MR (P<0.001). Dosimetric analysis of Dmax and D0.35cc exceeded 84.2% and 88.5% of times its respective threshold doses for CT-only dataset, whereas for the CT+MR dataset, it exceeded only by 18% and 15.7% times. 'Percent rank' function analysis for SC doses also indicates the same. CONCLUSION: This study supports MRI fusion for GTV and OAR delineation for non-spinal metastasis. Our study showed that the dosimetric analysis is vital for observer variation studies and the addition of the MR data set is significant to improve the confidence of Stereotactic treatments.

Smear layer and debris removal using manual Ni-Ti files compared with rotary Protaper Ni- Ti files - An In-Vitro SEM study.

BACKGROUND: Predictable successful endodontic therapy depends on correct diagnosis, effective cleaning, shaping and disinfection of the root canals and adequate obturation. Irrigation serves as a flush to remove debris, tissue solvent and lubricant from the canal irregularities; however these irregularities can restrict the complete debridement of root canal by mechanical instrumentation.Various types of hand and rotary instruments are used for the preparation of the root canal system to obtain debris free canals. The purpose of this study was to evaluate the amount of smear layer and debris removal on canal walls following the using of manual Nickel-Titanium (NiTi) files compared with rotary ProTaperNiTi files using a Scanning Electron Microscope in two individual groups. MATERIALS & METHODS: A comparative study consisting of 50 subjects randomized into two groups - 25 subjects in Group A (manual) and 25 subjects in Group B (rotary) was undertaken to investigate and compare the effects of smear layer and debris between manual and rotary NiTi instruments. Chi square test was used to find the significance of smear layer and debris removal in the coronal, middle and apical between Group A and Group B. RESULTS: Both systems of Rotary ProTaperNiTi and manual NiTi files used in the present study, did not create completely clean root canals. Manual NiTi files produced significantly less smear layer and debris compared to Rotary ProTaperNiTi instruments. Rotary instruments were less time consuming when compared to manual instruments. Instrument separation was not found to be significant with both the groups. CONCLUSIONS: Both systems of Rotary ProTaperNiTi and manual NiTi files used did not produce completely clean root canals. Manual NiTi files produced significantly less smear layer and debris compared to Rotary protaper instruments. How to cite the article: Reddy JM, Latha P, Gowda B, Manvikar V, Vijayalaxmi DB, Ponangi KC. Smear layer and debris removal using manual Ni-Ti files compared with rotary Protaper Ni-Ti files - An In-Vitro SEM study. J Int Oral Health 2014;6(1):89-94.

Municipal solid waste generation in Kathmandu, Nepal.

Waste stream characteristics must be understood to tackle waste management problems in Kathmandu Metropolitan City (KMC), Nepal. Three-stage stratified cluster sampling was used to evaluate solid waste data collected from 336 households in KMC. This information was combined with data collected regarding waste from restaurants, hotels, schools and streets. The study found that 497.3 g capita(-1) day(-1) of solid waste was generated from households and 48.5, 113.3 and 26.1 kg facility(-1) day(-1) of waste was generated from restaurants, hotels and schools, respectively. Street litter measured 69.3 metric tons day(-1). The average municipal solid waste generation rate was 523.8 metric tons day(-1) or 0.66 kg capita(-1) day(-1) as compared to the 320 metric tons day(-1) reported by the city. The coefficient of correlation between the number of people and the amount of waste produced was 0.94. Key household waste constituents included 71% organic wastes, 12% plastics, 7.5% paper and paper products, 5% dirt and construction debris and 1% hazardous wastes. Although the waste composition varied depending on the source, the composition analysis of waste from restaurants, hotels, schools and streets showed a high percentage of organic wastes. These numbers suggest a greater potential for recovery of organic wastes via composting and there is an opportunity for recycling. Because there is no previous inquiry of this scale in reporting comprehensive municipal solid waste generation in Nepal, this study can be treated as a baseline for other Nepalese municipalities.

Solubilization of mu-opioid receptors enriched from bovine brain membranes.

Solubilization is the most critical step in the purification of opioid receptors as these proteins are highly sensitive to detergents and get inactivated even with very mild detergents. Membranes enriched with micro-opioid receptors from bovine corpus striatum were solubilized by various methods to obtain the active soluble receptor suitable for affinity purification. Solubilization by digitonin resulted in marginal yields. CHAPS in presence of NaCl could extract active receptor into the solution. The detergent and NaCl were removed by either polyethylene glycol precipitation or by desalting on Sephadex G50. The polyethylene glycol precipitation resulted in the formation of liposomes into which the receptor protein was incorporated. Liposome formation was not observed in desalting method and the recovery of the receptor was partial.

Spinal extradural abscess following local steroid injection.

A case of spinal extradural abscess following local steroid injection for back ache, in a 26 years old male is described. The abscess presented as a swelling externally. MRI localised the lesion to L2-S1 segments. Mechanism of such an infection has been discussed.

Properties of a highly purified antifertility factor from human seminal plasma.

A high molecular weight antifertility factor (AF-1) was obtained in a high degree of purity from human seminal plasma by ultracentrifugation, CM-cellulose and concanavalin A chromatography, and Sepharose 6B gel filtration. A final purification step involving preparative disc electrophoresis was occasionally required. AF-1 showed a dose-dependent inhibition of the in vitro fertilizing ability of capacitated mouse spermatozoa, causing 50% inhibition of fertilization at approximately 27.5 micrograms/10(6) spermatozoa. Removal of the follicle cell layer of the oocyte did not decrease the antifertility effect of AF-1 but inhibition of fertilization was no longer observed after dispersal of the zona pellucida. The effect of AF-1 was on the spermatozoa and not on the oocytes. These results show that AF-1 treatment prevents capacitated spermatozoa from penetrating the zona pellucida and possibly the follicle cell layer. The mechanism by which AF-1 does so is not known because AF-1 did not prevent the in vitro acrosome reaction of guinea pig spermatozoa, nor did it inhibit the activity of human acrosin or bovine testicular hyaluronidase. The antifertility activity of AF-1 is reversed after recapacitation of the AF-1 treated spermatozoa and it can be assumed that AF-1 is either dissipated or loses activity during the transport of the spermatozoa through the female genital tract when capacitation takes place. AF-1 is heat labile. The properties of AF-1 are the same as those found previously for the pellet obtained by high-speed centrifugation of human seminal plasma, indicating that this is the primary, nonparticulate, high molecular weight factor with antifertility activity in human semen.

Inhibition of mouse sperm capacitation by ethanol.

Ethanol reduced the in vitro fertilizing capacity of mouse spermatozoa in a dose-dependent manner, at concentrations commonly observed after ethanol ingestion by man and experimental animals (100-400 mg%). At these ethanol levels, sperm motility and the integrity and fertilizing capacity of the oocyte were not affected, nor was parthenogenic cleavage induced. Data indicated that ethanol prevents the capacitation of the spermatozoa. Its inhibitory effect could be reversed by incubation of the alcohol-treated spermatozoa in alcohol-free capacitation medium. At similar concentrations, t-butanol had no effect on fertilization, suggesting that inhibition by ethanol is mediated by a mechanism other than a "solvent" effect. Although the alcohol dehydrogenase inhibitor, pyrazole, prevented the inhibition of fertilization by ethanol, acetaldehyde (the product of ethanol oxidation) was without effect. These data indicate that the inhibition of capacitation by ethanol is mediated via its metabolism by spermatozoa but not by the immediate product of ethanol oxidation.

A high molecular weight antifertility factor from human seminal plasma.

The presence of a high molecular weight antifertility factor in human seminal plasma was established. The factor can be precipitated by centrifugation at 104 000 g. Its activity is maximal when the protein concentration reaches 150 micrograms/10(5) spermatozoa using the mouse in-vitro fertilization assay as the test system. The factor is heat labile but its activity is not affected by dialysis. It prevents the penetration of the spermatozoa through the layers surrounding the egg but has no effect on the fusion of the spermatozoa with the vitelline membrane. The factor is only partly removed from spermatozoa by washing but is completely dispersed when the spermatozoa are incubated in capacitation medium. The pellet that is precipitated from the seminal plasma does not contain any particles or vesicles. However, it is significantly contaminated with low molecular weight material. This material includes the acrosin inhibitor which is present in large enough quantities to hinder fertilization. Washing the pellet twice with H2O removes these low molecular weight compounds, as indicated by the absence of the acrosin inhibitor, but has no effect on the antifertility properties of the pellet. Therefore, before further study or purification of the factor, it is essential that the pellet is washed such low molecular weight material. The washed pellet consists of at least 7 components as judged by disc gel electrophoresis.

Enzymic determination of fructose in seminal plasma by initial rate analysis.

We describe a spectrophotometric assay for fructose in seminal plasma. The method is based on reduction of fructose by a commercially available preparation of sorbitol dehydrogenase (EC 1.1.1.14), with the concomitant oxidation of NADH. The initial rate of NADH oxidation, which is proportional to the fructose content of seminal plasma, can be measured either with a recording spectrophotometer or by conventional two-point kinetic assay. The method was as accurate, precise, and sensitive as, and more specific and rapid than, currently used colorimetric (resorcinol) methods for fructose determination. Values (mmol/L) for fructose in seminal plasma from several species are: man, 9 +/- 2 (SD); cynamolgus monkey (Macaca fasicicularis)., 108 +/- 19; bull, 30 +/- 1; and rabbit, 13 +/- 4. These values agree with previously published results. We believe the method is appropriate for both research and clinical use.