Residence time distribution measurements in a pilot-scale poison tank using radiotracer technique.

Various types of systems are used to control the reactivity and shutting down of a nuclear reactor during emergency and routine shutdown operations. Injection of boron solution (borated water) into the core of a reactor is one of the commonly used methods during emergency operation. A pilot-scale poison tank was designed and fabricated to simulate injection of boron poison into the core of a reactor along with coolant water. In order to design a full-scale poison tank, it was desired to characterize flow of liquid from the tank. Residence time distribution (RTD) measurement and analysis was adopted to characterize the flow dynamics. Radiotracer technique was applied to measure RTD of aqueous phase in the tank using Bromine-82 as a radiotracer. RTD measurements were carried out with two different modes of operation of the tank and at different flow rates. In Mode-1, the radiotracer was instantaneously injected at the inlet and monitored at the outlet, whereas in Mode-2, the tank was filled with radiotracer and its concentration was measured at the outlet. From the measured RTD curves, mean residence times (MRTs), dead volume and fraction of liquid pumped in with time were determined. The treated RTD curves were modeled using suitable mathematical models. An axial dispersion model with high degree of backmixing was found suitable to describe flow when operated in Mode-1, whereas a tanks-in-series model with backmixing was found suitable to describe flow of the poison in the tank when operated in Mode-2. The results were utilized to scale-up and design a full-scale poison tank for a nuclear reactor.

Detection of orbicularis oris muscle defects in first degree relatives of cleft lip children using ultrasound.

OBJECTIVE: The severity of cleft lip (CL) varies considerably from complete bilateral CL and palate at one end of the spectrum to a minimal CL at the other. In some cases of microform clefting, there may be no visible manifestation of the defect on the lip surface (i.e., the defect is occult) and no residual functional deficit. This study used high resolution ultrasonography to detect subclinical anomalies of orbicularis oris muscle (OOM) in first degree relatives of CL +- cleft palate children and compared it with controls. MATERIALS AND METHODS: Thirty relatives of 25 children with non-syndromic CL or CL+ CP were identified for the study. Thirty subjects having negative family history of CL/P in three generations and absence of any minimal cleft features were taken as controls. Ultrasound scans of OOM of all the controls and relatives were taken. Statistical analysis was performed using standard χ2 tests with Yates correction. RESULTS: Defects were seen in 13.3% of relatives and no defects were seen in controls, this was not statistically significant. CONCLUSION: The data support the hypothesis that subclinical CL cases with subepithelial OOM defects do exist and Orbicularis oris discontinuities represent the mildest form of CL.

Analysis of 32 common susceptibility genetic variants and their combined effect in predicting risk of Type 2 diabetes and related traits in Indians.

AIMS: Recent genome-wide association studies have identified several Type 2 diabetes-related loci. We investigated the effect of susceptibility genetic variants, individually, together and in combination with conventional risk factors, on Type 2 diabetes and diabetes-related traits in Indians. METHODS: We genotyped 33 variants in 1808 Indian patients and 1549 control subjects and performed association analyses with Type 2 diabetes and related traits using an additive model for individual variant and for genetic risk score based on 32 polymorphisms. The discriminatory value of genetic risk over conventional risk factors was analysed using receiver-operating characteristics curve analysis. RESULTS: The allelic odds ratio ranged from 1.01 (95% CI 0.85-1.19) to 1.66 (95% CI 1.32-2.01) for single-variant analyses. Although, only 16 variants had significant odds ratios, the direction of association for others was similar to earlier reports. The odds ratio for Type 2 diabetes at each genetic risk score point was 1.11 (95% CI 1.09-1.14; P = 5.6 × 10(-17)) and individuals with extremes of genetic risk score (≥ 29.0 and ≤ 17.0) had a 7.5-fold difference in risk of Type 2 diabetes. The discrimination rate between control subjects and patients improved marginally on addition of genetic risk score to conventional risk factors (area under curve = 0.959 and 0.963, respectively; P = 0.001). Of all the quantitative traits analysed, MC4R variants showed strong association with BMI (P = 4.1 × 10(-4)), fat mass per cent (P = 2.4 × 10(-4)) and other obesity-related traits, including waist circumference and hip circumference (P = 2.0 × 10(-3) for both), as well as insulin resistance (P =0.02). CONCLUSIONS: We replicated the association of well-established common variants with Type 2 diabetes in Indians and observed a similar association as reported in Western populations. Combined analysis of 32 variants aids identification of subgroups at increased risk of Type 2 diabetes, but adds only a minor advantage over conventional risk factors.

Efficacy and tolerability of cefditoren pivoxil in uncomplicated skin and skin structure infections in Indian patients.

BACKGROUND: Uncomplicated skin and skin structure infections (uSSSI) are commonly encountered community-acquired infections and are typically confined to the superficial layers of the skin. Hence, they seldom lead to the destruction of skin structures. AIMS: To evaluate the efficacy and tolerability of cefditoren pivoxil in uSSSI in Indian patients. METHODS: One hundred and seventy-eight patients diagnosed with uncomplicated SSSI were enrolled in this randomized, comparative, multicentric study. Patients received either cefditoren pivoxil or cefdinir for ten days. Efficacy was assessed both clinically and microbiologically. Safety evaluation consisted of reporting of type, frequency, severity, and causal relationship of adverse events. RESULTS: One hundred and fifty-one patients completed the study. Clinical and bacteriological efficacy of cefditoren pivoxil was comparable to that of cefdinir in the treatment of uSSSI. One hundred and five patients were eligible for per protocol (PP) analysis of bacteriological outcome and clinical efficacy. Clinical cure or improvement was achieved in 98.00% patients treated with cefditoren pivoxil and 98.18% patients treated with cefdinir. In the modified Intent to Treat (mITT) patient population, clinical cure or improvement was recorded in 97.33% patients treated with cefditoren pivoxil and 96.20% patients treated with cefdinir. Microbiological eradication (or presumed eradication) was recorded in 88.00% patients treated with cefditoren pivoxil and 94.55% patients treated with cefdinir. The above differences in the outcome rates between the two drugs were not statistically significant. Six adverse events (AEs) (two in cefditoren group and four in cefdinir group) were reported in this study. CONCLUSION: Cefditoren pivoxil 200 mg b.i.d. was effective and well tolerated in the treatment of uSSSI.

Rhinosporidiosis: a study that resolves etiologic controversies.

We have been able to isolate the cyanobacterium Microcystis aeruginosa from water samples of ponds and river where patients of rhinosporidiosis were bathing. It is likely that this cyanobacterium is the causative agents of this disease. The bluish-green cells of M. aeruginosa also have a colorless small cell stage called nanocyte which has been detected in clear waters of all the pond and river samples studied. Both large cells and nanocytes of M. aeruginosa could be recognized inside the round bodies of rhinosporidiosis by light and electron microscopy. Further work on culturing this organism from excised samples and evaluation for drug therapy are in progress. It is hoped that, if therapy becomes available, no surgery would be required for this disease. It is suggested that the waters from ponds and lakes, as well as municipal and recreational waters, be checked for the nanocyte stage of M. aeruginosa. Etiological controversies of rhinosporidiosis have been reasonably solved. The new findings justify a change in the name "rhinosporidiosis" that had been associated with the fungus Rhinosporidium Seeberi.

Colonic hyperproliferation induced in rats and mice by nutritional-stress diets containing four components of a human Western-style diet (series 2).

In a previous study colonic hyperplasia and hyperproliferation were induced in mice and rats by a nutritional-stress diet, based on the AIN-76A semisynthetic diet modified to contain four suggested high-risk components of the human Western-style diet: increased fat and phosphate and decreased calcium and vitamin D contents. In this study the effect of raising calcium alone to near the median level (0.22 mg/kcal) and to a high level (1.3 mg/kcal), comparable to adult human dietary intake, was tested in mice and rats while retaining the three other high-risk components. With median calcium intake the nutritional-stress diet induced hyperproliferation of epithelial cells in colonic crypts, with increased numbers of proliferating cells in crypt columns in sigmoid colon of mice (P less than 0.001) and rats (P = 0.02) and in the ascending colon of mice (P = 0.01). With high calcium intake, hyperproliferation was reduced almost to control amounts in the presence of unchanged fat, phosphate, and vitamin D.

Colonic hyperplasia and hyperproliferation induced by a nutritional stress diet with four components of Western-style diet.

We studied the effects of specific nutritional modifications on colonic epithelial cell proliferation in mice and rats. The nutritional stress diet developed for this study was based on the AIN (American Institute of Nutrition)-76A semisynthetic diet, modified to contain four suggested risk factors of the human Western-style diet: increased fat and phosphate and decreased calcium and vitamin D content. We fed diets to mice and rats for 12 weeks beginning at 3 weeks of age. Hyperplasia developed in both sigmoid and ascending colon of mice and rats with lengthening of colonic crypts. Hyperproliferation developed in the sigmoid colon of mice and rats, and in the ascending colon of rats, with increased [3H]thymidine-labeling of epithelial cells. Thus, in colonic mucosa, the nutritional stress diet, which included risk factors of a Western-style diet, induced changes that occur in carcinogen-induced rodent models and in humans who are at increased risk for colonic neoplasia.

Role of Catecholamines in Promotion of Flowering in a Short-Day Duckweed, Lemna paucicostata 6746.

l-Epinephrine, l-norepinephrine, and l-isoproterenol substantially promote flowering under a photoperiodic regime of 8 hours light and 16 hours darkness in Lemna paucicostata 6746 when grown on the modified Bonner-Devirian medium devoid of ethylenediaminetetraacetic acid. If catecholamines are provided to plants at 10(-4) molar level prior to transferring them to the short-day regime, they not only induce more floral primordia but also significantly improve flower development and sustain the flowers for a longer period. Propranolol (10(-4) molar), a beta-adrenergic blocking agent, partially suppresses flowering and the inhibition of flowering is relieved by catecholamines.

Plant regeneration from tissue cultures initiated from immature inflorescences of a grass,Echinochloa colonum (L.) link.

Organised structures develop on a white and compact callus initiated from small segments of immature inflorescences ofEchinochloa colonum cultured on Murashige and Skoog's (MS) medium supplemented with 5.0 mg/l 2,4-dichlorophenoxyacetic acid (2,4-D) and 10% coconut milk. These develop into plantlets upon subculture onto MS medium containing 0 or 0.2 mg/l 2,4-D. Twelve out of 17 plantlets regenerated grew well on transfer to soil and eleven plants produced seeds.