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D V Naik

Publications and source records attributed to D V Naik.

At least 19 recordsLinked to original sources
PubMed1989

Indoor ozone exposures.

Indoor and outdoor ozone concentrations were measured from late May through October at three office buildings with very different ventilation rates. The indoor values closely tracked the outdoor values, and, depending on the ventilation rate, were 20 to 80 percent of those outdoors. The indoor/outdoor data are adequately described with a mass balance model. The model can also be coupled with reported air exchange rates to estimate indoor/outdoor ratios for other structures. The results from this and previous studies indicate that indoor concentrations are frequently a significant fraction of outdoor values. These observations, and the fact that most people spend greater than 90 percent of their time indoors, indicate that indoor ozone exposure (concentration X time) is greater than outdoor exposure for many people. Relatively inexpensive strategies exist to reduce indoor ozone levels, and these could be implemented to reduce the public's total ozone exposure.

Air Pollution↗
PubMed1977

In vitro adsorption of doxorubicin hydrochloride on insoluble calcium phosphate.

The adsorption of doxorubicin hydrochloride, a potent antitumor agent, on solid tribasic calcium phosphate was studied in vitro. A Langmuir adsorption isotherm at pH 7.4 and the maximum adsorption capacity of tribasic calcium phosphate were established. Tribasic calcium phosphate was chosen as a model for solid bone samples, which are stained with doxorubicin in patients who have received long-term doxorubicin therapy.

Adsorption↗
PubMed1976

Immuno-histochemical localization of LH-RH during different phases of estrus cycle of rat, with reference to the preoptic and arcuate neurons, and the ependymal cells.

Immunohistochemical localization of luteinizing hormone-releasing hormone (LH-RH), during different phases of the estrus cycle, in the preoptic, suprachiasmatic and arcuate nuclei, and in the OVLT of rats, with special emphasis on the ependymal cells, was studied by light, fluorescent and electron microscopy, by using rabbit anti serum to synthetic LH-RH. The LH-RH neurons in the above mentioned areas, were very active during late diestrus and early proestrus phases. Specialized ependymal cells bordering the 3rd ventricle also showed varied LH-RH positive reaction during different phases of the estrus cycle. Immunofluorescent studies showed cyclic variations in the LH-RH material in the CSF of the preoptic and infundibular recesses, as well as in the 3rd ventricle near OVLT, in that, it was maximum during late diestrus and early proestrus phases. Immediately after this, the LH-RH late proestrus was reached. We have also observed that during the proestrus phase, as the LH-RH material started declining in the CSF, it had started building up in the specialized ependyma. Estrus, metaestrus and early diestrus phases showed very weak immunofluorescent LH-RH material in the lumen of the infundibular recess and in the specialized ependyma. Our immuno-electron microscopic observations showed pleomorphic LH-RH granules in the specialized ependyma during late kiestrus and proestrus phases. All these observations lead us to believe that LH-RH is not synthesized in the ependymal cells,but is phagocytosed from the CSF of the 3rd ventricle by the specialized ependyma, which transports it to the ME portal system. In males, the fluorescent LH-RH material did not show any noticeable changes. With the present and previous work,it is concluded that the neurons in differentnuclei synthesize LH-RH and transport it to the ME portal system,primarily through the nerve fibers and secondarily by the ventricular route. It is also suggested that the ependymal transport of LH-RH to the ME portal system is cyclic and thus controls the gonadotropin secretion.

Animals↗
PubMed1975

Electronic spectra and electronic structures of some antimicrobials derived from proflavine.

The shifts in the absorption and fluorescence spectra of 3-aminoacridine, proflavine, acridine orange, and acridine yellow were employed to show that the singly charged cations, the predominant species at biological pH, exist in the ground state in the amino form. In the lowest excited singlet state, however, the monocations of the diaminoacridines have the imino structure, a conclusion supported by the relative ground- and excited-state pKa values of the reactions of the monocation with H-+. The ground-state amino structure has its positive charge concentrated at the heterocyclic nitrogen atom, a fact that is of primary importance in determining the geometry of binding to DNA.

Acridines↗
PubMed1975

Binding of cupric ions to bovine serum albumin.

The binding of cupric ions to bovine serum albumin was investigated by using a cupric-ion-specific electrode. When using a modified form of the Scatchard equation, it was determined that there are at least two classes of binding sites on bovine serum albumin for cupric ions. One class has three binding sites of relatively strong affinity, with an average binding constant of 3.0 times 10(6). The other class has about 16 binding sites of relatively weak affinity, with an average binding constant of 2.0 times 10(4).

Animals↗
PubMed1975

Fluorometric determination of drug-protein association constants: binding of pamaquine by bovine serum albumin.

The binding of pamaquine to bovine serum albumin is accompanied by the enhancement of the fluorescence efficiency of the former but without shifting its fluorescence energy. This phenomenon was used to evaluate the stoichiometry and strength of the binding. The results indicate that three singly protonated pamaquine molecules are bound by each bovine serum albumine molecule. The individual binding constants were calculated by using the Bjerrum technique. The average values of the three constants were K1 = 6.4 X 10(7), K2 = 3.1 X 10(6), and K3 = 1.9 X 10(5), indicating that, compared to anionic drugs and fluorescent probes, pamaquine is very strongly bound by the protein.

Aminoquinolines↗
PubMed1975

Immunoreactive LH-RH neurons in the hypothalamus identified by light and fluorescent microscopy.

The sites of luteinizing hormone-releasing hormone (LH-RH) neurons and their axonal pathways in the hypothalmi of rats and mice were studied by the immunoglobulin-peroxidase bridge technique and b) the immunofluorescent isothiocyanate technique, using rabbit antiserum to synthetic LH-RH. Both of these techniques give similar results concerning LH-RH localization both in rats and mice. The immunoreactive LH-RH positive neurons are about 18-26 mu in diameter, mostly angular, pyriform or spindle shaped and very rarely oval or round. Most of these neurons are generally scattered in the hypothalamus. In the preoptic and medial preshiasmatic areas, ventromedial, arcuate nuclei and ventrolateral-premammillary body, the neurons are numerous and mostly in groups of 3-6. In other areas of the hypothalamus surrounding the suprachiasmatic area, supraoptic area, paraventricular nuclei and the anterior hypothalamic area, the LH-RH neurons are few and scattered. Very few neurons occur in the median eminence or in the infundibular stem. Major projections of LH-RH neurons apparently originate from preoptic, prechiasmatic and surrounding suprachiasmatic area, and from the anterior hypothalamic area. The fibres run in the fabrillar zone, descend in the external infundibular zone, and finally terminate for the most part around the capillaries of the primary portal plexus of the hypophysis. Other major groups of fibres apparently originate from the arcuate and ventromedial neurons. These fibres bend above the fibrous zone for some distance, ultimately descending in the zona palisadica and zona granulosa of the median eminence, towards the capillaries. The fibers of the ventrolateral-premammillary neurons are seen on the floor of the premammillary recess of 3rd ventricle and apparently terminate close to the capillaries in the infundibular region. Most of the LH-RH nerve fibres terminate near the primary portal plexus of the hypophysis, while some terminate in the pars tuberalis and a few seem to terminate in the 3rd ventricle. The LH-RH antiserum is ineffective after absorption with the antigen, so the staining reaction appears to be specific for LH-RH.

Animals↗
PubMed1975

Immuno-electron microscopic localization of luteinizing hormone-releasing hormone in the arcuate nuclei and median eminence of the rat.

Luteinizing hormone-releasing hormone (LH-RH) was localized in neurons of the arcuate nucleus and median eminence, and in many of the nerve fibres of the median eminence of the rat, by using antisera to synthetic LH-RH with the immunoglobulin-peroxidase technique or by using a soluble peroxidase-antiperoxidase complex at the electron microsc opic level. Many of the arcuate neurons and some of the median eminence neurons contained numerous densely stained granules elsewhere in the cytoplasm. Similar granules, positive for LH-RH, were observed in many nerve profiles around the capillaries of the primary portal plexus of zona palisadica and zona granulosa of the medain eminence, and such profiles may represent the release sites of LH-RH into the portal vessels. About 20% of the nerve profiles around the primary portal plexus were LH-RH positive and the rest of the nerve profiles were negative. The negative profiles may belong to other hypophysiotropic hormones and/or to catecholaminergic fibers. Some nerve endings at the ventricular surface of the ependymal cells, in contact with the ventricular fluid, were also LH-RH positive. These nerve endings probably release their secretion into the cerebrospinal fluid. There was no staining of the mitochondria, the nuclei or the axonal membranes. Stain of varying intensity was seen in the secretory granules, and within and around the cisternae of the Golgi complex. The stained granules in the cisternae wer pleomorphic. From these observations it was concluded that the LH-RH is packaged or condensed into granules in the Golgi cisternae.

Animals↗
PubMed1975

An improved technique for transauricular hypophysectomy and auto transplant of isolated pieces of pars intermedia tissue in the evacuated pituitary capsule of the rat.

An improved technique for transauricular hypophysectomy in rats, weighing 120-300 g, is described. This method can be used for transplantation studies, which is demonstrated by transplanting pars intermedia tissue into the evacuated pituitary capsule. Our technique has been carried out, successfully, in various laboratories. The success, however, depends upon the skill and care of the investigator.

Animals↗