Non-cytotoxic dimedone derivatives: structure, antiradical and UV protective studies.

Dimedone derivatives (L1-L4) with methyl substitution at the ortho, para and meta positions were synthesized and their anti-radical, photoreactive and photostability activities were evaluated. All compounds are characterized by spectroscopic techniques and by single crystal X ray diffraction. UV exposure experiments on pBR322 showed inhibition of plasmid DNA fragmentation by UV radiation in a dose dependent manner. Radical scavenging assays and ESR spectra indicate that these compounds possess antiradical activities and do not photodegrade to form other side products as confirmed by chromatographic analysis. They are non-cytotoxic towards human keratinocyte HaCaT cell line indicates their potentiality in sunscreens.

Practicality of production of ³²P by direct neutron activation for its utilization in bone pain palliation as Na3[³²P]PO4.

Large-scale production of ³²P for its clinical use in palliative care of painful bone metastasis in the form of Na3[³²P]PO4 (³²P-sodium orthophosphate) has been practiced for six decades. The classical route of production of ³²P by (n,p) reaction on high purity elemental sulfur yields no-carrier-added (NCA) ³²P. Since high specific activity ³²P is not essential for the formulation of Na3[³²P]PO4 for bone pain palliation, an alternate route of production of ³²P by direct neutron capture using elemental phosphorus target [(31)P(n,γ)³²P] was envisaged and its suitability for use in bone pain palliation was evaluated. Toward this, irradiation of elemental red phosphorus target was carried out at a neutron flux of 8×10¹³ n/cm².s for 60 days and this yielded ³²P with a specific activity of 230±15 MBq/mg (6.2±0.4 mCi/mg) having >99.9% radionuclidic purity. About 370-555 MBq (10-15 mCi) doses of Na3[³²P]PO4 were formulated in sterile saline (pH 7.4) using the ³²P produced. The radiochemical purity of the formulation was found to be ~99% with respect to PO4³â». The formulation exhibited good in vitro stability in saline and in human serum. Biodistribution studies carried out in normal Wistar rats revealed comparable pharmacokinetic properties of the formulation prepared using (n,γ) produced ³²P with that of NCA ³²P produced by (n,p) route. Besides having the advantages of simplicity in radiochemical processing and minimum radioactive waste generation, use of the proposed production route in place of the traditional ³²S(n,p)³²P route would result in better utilization of irradiation volume of research reactors.

Assessment of performance of UV sterilizer for room air bacteria.

Paper presents a technique for performance of UV sterilizer for room air bacteria. Patterns of decay of room air bacteria concentration during sterilization and build-up there after as a function of time is studied. Decay process seems to follow exponential pattern. Half-lives during decay are estimated. For single sterilizer unit with a dose of 16 W the decay half-life is around 8.6 min. For the dose of 32 W (2 sterilizers), half-life is estimated to be 6.18 min. The removal rates of room air bacteria due to sterilizer are compared with the natural decay of aerosols at steady state. The importance of decay half-life in the assessment has been stated. The bacteria concentration buildup process after putting off the sterilizers seems to be sigmoidal in nature. The buildup half-life is estimated to be around 53 min for present experimental conditions.

Database requirements for epidemiological estimates of radiation risks in continuously exposed populations.

Using the revised risk coefficients recommended by the 1990 report of the International Commission of Radiological Protection (ICRP), computations have been made on the minimum databases required for detecting radiogenic cancer excesses from epidemiological surveys of populations exposed to low level radiations. The computations have been made separately for Indian and Western populations using their representative demographic data. The western database requirements are generally found to be about half the Indian requirement. For the exposures in high background radiation areas at the rate of say 5 mSv/y, the minimum required database is 121,500 person years, in the Indian case. Similarly, for Indian occupational workers exposed at the rate of say, 10 mSv/y, it is required to observe 30,000 persons for the first 40 years or 3600 persons over their entire lifetime for obtaining statistically significant results.

Histomorophological studies of the female reproductive system of Platynotus punctatipennis (Coleoptera: Tenebrionidae).

The internal reproductive apparatus of female Platynotus punctatipennis is composed of the paired ovaries, paired lateral oviducts, common oviduct, spermatheca associated with its accessory gland, and a bursa copulatrix. The accessory (colleterial) glands are absent. The ovary is made up of a large number of telotrophic ovarioles which are covered by a double-layered peritoneal sheath. The terminal filament is separated from the germarium by the basement membrane of the latter and consists of a syncytial core surrounded by the peritoneal sheath. Nutritive cords are absent. The pedicel shows highly eosinophilic and PAS-positive secretion of obscure origin. The spermatheca reveals a number of interesting features. It is composed of a pair of sperm-storing tubules, enclosed in a very thin muscle layer. A winecup-like structure, provided with a thick coat of circular muscles, connects the spermathecal gland with thespermathecal duct. Four types of intimal linings occur in the spermatheca and its associated structures. The wine-cup-like connection and four types of intima are entirely new features observed. Histology of the various parts of the reproductive apparatus is described.

Ocular manifestations of leprosy

This study covers 654 patients of leprosy who were predominatly of non-lepromatous type. Detailed examination of eyes has been done and ocular manifestations noted. Ocular manifestations with a bearing on status of treatment, extent of disease and duration of disease have been studied. The salient changes include sluggish corneal reflex, loss of eyebrows, madarosis and nodules on eyebrows. Patients suffering for 4 years and more manifested damage to iris, cornea and lens. the article stresses the importance of routine examinations of eyes (including slit lamp examination) at the beginning of therapy and periodical check-up thereafter. It also emphasizes that the non lepromatous patients also exhibit eye changes to a sizeable degree, through not to the same extent as lepromatous variety.