Preferential growth of haploid plant cells in vitro.
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Biomedical subjects
Publications and source records attributed to N Gupta.
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Clinical trials for binary therapies, like boron neutron capture therapy (BNCT), pose a number of unique problems and challenges in design, performance, and interpretation of results. In neutron beam development, different groups use different optimization parameters, resulting in beams being considerably different from each other. The design, development, testing, execution of patient pharmacokinetics and the evaluation of results from these studies differ widely. Finally, the clinical trials involving patient treatments vary in many aspects such as their dose escalation strategies, treatment planning methodologies, and the reporting of data. The implications of these differences in the data accrued from these trials are discussed. The BNCT community needs to standardize each aspect of the design, implementation, and reporting of clinical trials so that the data can be used meaningfully.
It is a universally known fact that maternal well-being is related to neonatal health. This case-control study aims to assess the pattern and strength of association of neonatal morbidity and mortality (in first 7 days of life) in relation to the presence of obstetric & medical risk factors in the mother (indicating maternal ill-health). In 250 cases (at-risk pregnancies), 75 (30%) developed neonatal illnesses while 17 (6.8%) perinatal deaths occurred in first seven days. In the same number of controls (uncomplicated pregnancies) there were only two perinatal deaths and lesser number of newborns (45/250, 16.4%) developed neonatal diseases in the first 7 days. Perinatal deaths, (still births and early neonatal deaths), (OR = 9.05; AR = 88.2%) and neonatal illnesses (OR = 2.2 and AR = 45) were strongly associated with presence of maternal risk factors. This study supports the fact that 'at risk' pregnancies have highly significant chances of developing early (first 7 days) neonatal morbidity (p < 0.001) and mortality (p < 0.001). Still births also occurred significantly more (p < 0.005) in number among 'at risk' (cases) than normal term pregnancies (controls).
PURPOSE: There has been recent interest in the use of brachytherapy for the possible prevention of restenosis after angioplasty. However, this field is unfamiliar to most interventional cardiologists. This article is meant to serve as an introduction to the principles of brachytherapy especially as it applies to intravascular brachytherapy. Because the intended audience is the interventional cardiologist, the details of physics, radiobiology, and radiation jargon has been kept at a minimum. METHODS: The main advantages of brachytherapy are that it can irradiate small volumes and conform to the target volume while sparing the surrounding normal tissues from the deleterious effects of irradiation. Various gamma- or beta-emitting radioisotopes can deliver the brachytherapy dose. In general, the beta emitters have fewer radiation exposure hazards, but the limited penetration of beta emitters can be a problem if deeper tissues need to be irradiated. Gamma sources can irradiate deeper but suffer from greater radiation exposure hazards. It should be remembered that the biological effects of radiation depend on a number of parameters, including the radiation modality, dose, dose rate, fractionation, treatment duration, dose prescription point, and the volume irradiated. The use of low energy isotopes, beta emitters, and remote-controlled afterloading has reduced the radiation exposure to the medical caregivers. CONCLUSION: Intravascular brachytherapy is currently considered to be experimental. Those wishing to start a new intravascular brachytherapy program should comply with the required federal and state regulatory guidelines issued by the Nuclear Regulatory Commission, Food and Drug Administration, and their individual Institutional Review Board.
The effect of head phantom size on the 10B and 1H[n,gamma]2H dose distributions for a broad epithermal neutron radiation field generated by an accelerator-based epithermal neutron source for boron neutron capture therapy (BNCT) have been studied. Also two techniques for calculating the absorbed gamma dose from a measured gamma-ray source distribution are compared: a Monte Carlo technique, which is well accepted in the BNCT community, and a Point Kernel technique. The count-rate distribution in the central plane of three rectangular parallelopiped head water phantoms irradiated with an epithermal neutron field was measured with a boron trifluoride (BF3) detector. This epithermal neutron field was produced at the Ohio State University Van de Graaff Accelerator Facility. The 10B absorbed dose and the gamma-ray source have the same distribution in the head phantom as the BF3 count-rate distribution. The absorbed gamma dose from the measured source distribution was calculated using MCNP, a Monte Carlo code, and QAD-CGGP, a Point Kernel code. The most pronounced effect of phantom size on 10B absorbed dose was on the dose rate at the depth of maximum dose, dmax. An increase in dose rate at dmax was observed with a decrease in phantom size, the dose rate in the smallest phantom being larger by a factor of 1.4 than the dose rate in the largest phantom. Also, dmax for the phantoms shifted deeper with a decrease in phantom dimensions. The shift between the largest and the smallest phantoms was 6 mm. Finally, the smaller phantoms had lower entrance 10B dose as a percent of the dose at dmax, or better skin sparing. Our calculations for the gamma dose show that a Point Kernel technique can be used to calculate the dose distribution as accurately as a Monte Carlo technique, in much shorter computation times.
Ultrasonography and magnetic resonance imaging performed upon a male fetus at 32 and 36 weeks gestation, respectively, revealed a large suprasellar mass. A male newborn, delivered at 37 weeks, required ventilatory assistance at birth and subsequently developed myoclonic seizures, hypertension, and bradycardia. The intracranial mass was felt to be inoperable and the patient expired shortly after support was withdrawn. Autopsy results were consistent with a congenital craniopharyngioma. We discuss the differential diagnosis for this mass lesion based on prenatal imaging as well as distinguishing features on imaging studies that may aid in the prenatal diagnosis and treatment of this benign tumor.
In vitro study with chicken bursal organ culture was attempted to assess the pathogenicity of locally isolated infectious bursal disease virus (IBDV) initially isolated from the bursa of naturally infected birds. In bursal organ culture, lymphoblastic transformation was noticed as early as 24 hr postinoculation and reached maximum at 72 hr postinoculation. The other microscopic changes were increased number of macrophages and formation of plasma cells. The IBDV antigen was detected 24 hr onward by coagglutination test with antibody coated Staphylococcus aureus strain Cowan I. On the basis of lesion score, the three isolates of IBDV (A, B, and C) were graded as virulent (B isolate) and moderately virulent (A and C isolates). A similar pattern of pathogenicity was also observed in the in vivo pathogenicity studies in chicken based on bursa: body weight ratio and histopathologic lesion score. The bursal organ culture thus provides a useful experimental model to differentiate the IBDV isolates on the basis of their virulence.
A case of undifferentiated giant cell type bronchogenic carcinoma in an old man is reported. Following bronchoscopy, the patient expectorated tumour mass tissue in his sputum and was relieved of breathlessness to a great extent.
An experimental study was undertaken to observe effects of fluoride ingestion on lung tissue. The study was conducted on 15 albino rabbits of either sex and experimental fluorosis was induced by daily oral administration of sodium fluoride (NaF) solution. Rabbits were divided into three groups according to the quantity of fluoride ingestion: Group A: rabbits fed with 10 mg/kg/day NaF, Group B: 20 mg/kg/day NaF; and Group C: controls. After six months, the rabbits were sacrificed and their lung tissue was submitted for histopathological examination and fluoride content estimation. On gross examination, pale areas on the surface and dark brown congested areas on cut-section of lungs were seen in rabbits of groups A and B. Histopathological changes of alveolar haemorrhage, congestion, edema fluid, necrosis of alveolar epithelium, distortion of alveolar architecture and desquamation of epithelium of respiratory tract with damage to tracheal cartilage were observed in these groups. These changes were more marked in group B rabbits. Fluoride content of lung tissue homogenate was significantly higher in groups A and B (mean 1.206 ppm and 1.978 ppm respectively) as compared to control (0.1585 ppm). It was concluded that prolonged fluoride ingestion damages pulmonary tissues of rabbits. To the best of our knowledge, effect of chronic fluoride ingestion on lungs has not been reported in the literature, therefore, we had undertaken this study to analyse the effect of chronic fluoride ingestion on lungs.
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To examine the prognostic significance of total cholesterol levels at baseline in subjects with stable coronary heart disease, 605 patients with stable coronary heart disease were enrolled; 45 of these did not meet inclusion criteria, 41 were lost to follow-up and 40 opted for coronary bypass surgery. Data of the remaining 479 (389 males, 90 females) were analysed. There were 102 males in group I (cholesterol < 200 mg/dL), 187 in group II (cholesterol 200-239 mg/dL), and 100 in group III (cholesterol > or = 240 mg/dL) and 49 females in group I and 41 in group II. The groups were evenly matched for age and numbers with stable angina or survivors of myocardial infarction. Proportion of smokers, hypertensives, diabetics or obese was also similar (p > 0.05). Mean follow-up in years in men was 6.82 +/- 3.15 in group I, 6.37 +/- 3.11 in group II and 6.81 +/- 2.84 in group III while in women it was 6.95 +/- 2.84 in group I and 7.03 +/- 2.58 years in group II and was not different in various groups (p > 0.05). The overall cardiovascular mortality in various groups in men was 20.6 percent in group I, 28.9 percent in group II and 23.0 percent in group III and in women it was 14.3 percent in group I and 22.0 percent in group II. The crude mortality rate was 2.51 percent per year in males and 1.77 percent per year in females. Actuarial survival at end of seven years in males was 0.76 +/- 0.05 in group I, 0.67 +/- 0.04 in group II, and 0.67 +/- 0.05 in group III and in females it was 0.85 +/- 0.05 in group I and 0.73 +/- 0.09 in group II. The cumulative hazard rates per 1000 person- year follow-up in group I, II and III in males were, at age less than 50 years: 5.4 +/- 5, 19.8 +/- 7, 17.4 +/- 8; at 50-59 years: 23.8 +/- 11, 38.5 +/- 9, 39.8 +/- 13; and at 60 years and over: 76.9 +/- 20, 112.6 +/- 20, 108.2 +/- 28, respectively (p < 0.001 on comparison of group I with groups II and III). In females the trends were not significant. Total cholesterol levels at baseline predict long-term cardiovascular mortality in men with stable coronary heart disease.
Ninety seven patients (63 males, mean age 31.8 years, SD 2.3) with various forms of tuberculosis were studied. All of them were HIV negative. Thirty normal control subjects (16 males, mean age 36.4 years, SD 1.8) were also studied. Fifty-eight of the 97 patients (59.8%) were malnourished (BMI < 18 kg/m2). The mean basal serum cortisol was lower in the TB group (n = 91) (351 nmol/1; SD 150) as compared to the normal control group (n = 8) (402 nmol/1; SD 93) but this difference did not attain statistical significance. Following administration of synthetic ACTH (cosyntropin), the 30 and 60 minutes mean serum cortisol values in the TB group were significantly lower as compared to the normal control group (p < 0.05). Forty five of the 91 patients (49.5%) who underwent the ACTH stimulation test had compromised adrenal reserve. Fourteen of the 86 patients (16.3%) in whom adrenal morphology was studied revealed adrenal gland enlargement on abdominal CT scan. ACTH stimulation was done in 12 of these 14 patients and eight of them had compromised adrenal reserve. Repeat ACTH stimulation done six months to one year after treatment in 13 patients revealed significantly increased 30 minutes (p < 0.05) and 60 minutes (p < 0.05) serum cortisol values. While nine of these 13 patients were negative responders before treatment, only three of them had evidence of compromised adrenal reserve after one year of antituberculosis treatment, (p < 0.05). Serum cortisol values in patients with drug-sensitive and drug-resistant tuberculosis did not differ significantly. Patients with drug-resistant tuberculosis had a higher prevalence of adrenal gland enlargement (7 of the 30) as compared to those with drug-sensitive tuberculosis (7 of the 56) (p = NS). Subclinical adrenal insufficiency is prevalent in a significant number of patients with both drug-sensitive and drug-resistant tuberculosis, and in some of these it is associated with adrenal gland enlargement. The compromised adrenal reserve and enlargement seem to reverse with therapy.