Steroids affect many tissues, including the brain. In the zebra finch, the estrogenic steroid est... more Steroids affect many tissues, including the brain. In the zebra finch, the estrogenic steroid estradiol (E2) is especially effective at promoting growth of the neural circuit specialized for song. In this species, only the males sing and they have a much larger and more interconnected song circuit than females. Thus, it was surprising that the gene for 17beta-hydroxysteroid dehydrogenase type 4 (HSD17B4), an enzyme that converts E2 to a less potent estrogen, had been mapped to the Z sex chromosome. As a consequence, it was likely that HSD17B4 was differentially expressed in males (ZZ) and females (ZW) because dosage compensation of Z chromosome genes is incomplete in birds. If a higher abundance of HSD17B4 mRNA in males than females was translated into functional enzyme in the brain, then contrary to expectation, males could produce less E2 in their brains than females. Here, we used molecular and biochemical techniques to confirm the HSD17B4 Z chromosome location in the zebra finch...
... POST NATAL LECITHOTROPH: A NEW AGE CLASS IN THE ONTOGENY OF REPTILESVALENTINE A. LANCE1, AND ... more ... POST NATAL LECITHOTROPH: A NEW AGE CLASS IN THE ONTOGENY OF REPTILESVALENTINE A. LANCE1, AND DAVID J. MORAFKA2 'Center for Reproduction of Endangered Species, PO. ... The decision to ger-minate or hatch is a bet with high stakes". ...
Neonatal reptiles are here defined as an age class of young eureptilian amniotes (excluding birds... more Neonatal reptiles are here defined as an age class of young eureptilian amniotes (excluding birds) that express attributes most influenced by the pre-paritive development environ- ment (oviduct, egg, and egg nest) and by the demands of parition and first dispersal. Neonatal character states are typically transformed, reduced, or eliminated during the first 10% of their pre- reproductive development. Traditionally, neonates have not been distinguished from juvenile rep- tiles. As a result the neonatology of reptiles has rarely been addressed in past literature. Recent studies reveal a complex array of developmental scenarios involving character state transformations, heterochrony, unique character states in morphology, behavior, physiology, nutrition, dispersion and health. Unique morphological features (such as egg teeth) and limited skeletal ossification charac- terize many neonates. Distinguishing behaviors include "reversal" movements, utilization of bright color patterns, and startling movements with both serving as anti-predation mechanisms. Prolonged association with protective parents, group migration, unique agonistic behavior, and tendencies to- ward rapid dispersion characterize the neonates of individual species. Neonatal physiological attri- butes include: a special availability to inoculation by symbiont fermenting anaerobes in herbivores, rapid conforming responses to their external environments in thermal and hydric exchanges, and in the case of some turtles, extraordinary capacities for supercooling (8.9 C). Post-paritive lecithotrophy (nutrition from residual yolk) sustain both the overwintering of nestlings and the dispersion of non- feeding young for as long as several months. Resistance to infections (such as mycoplasmas) from their maternal parents, combine with nutritive reserves of residual yolk and a common tendency for rapid dispersion to make neonates attractive candidates for augmentation and translocation programs. Coupled with the practical advantages of maintaining and manipulating small animals in a laboratory environment, these qualities distinguish neonates as particularly useful models for ex- perimentally evaluating the relative apportionment of reproductive resources into greater numbers of offspring or into improved quality/survivorship of individual offspring.
Industrial effluents, when discharged into rivers, may cause deleterious effects on fish and othe... more Industrial effluents, when discharged into rivers, may cause deleterious effects on fish and other aquatic oganisms. In ~e~al: the Narayani River has been receiving efluents from several industries including the Bhrikuti Pulp and Paper Mills. Thus, the main objective of this study was to determine impact of industrial pollution on fish fauna and to estimate the level of the heavy metal content in the tissues in fish from the above river Fish samples were collected from three sites, viz. Site-1 near Devghat, Site-2 at Gaindakot in the mixing zone, and Site-3 nearTriveni, in two seasons, rainy and summer. Fish were separated by species and analyzed for heavy metal content using atomic absorption spectrophotometry. The results of fish collections from three sites showed that the number of fish species was less in the polluted area i.e. at Site-2, located near the factory outlet. Chemical analysis of the tissues of fish showed that heavy metals were present in the order of Zn>Cu>C...
Advances in Experimental Medicine and Biology, 1985
Although somatostatin itself has numerous inhibitory activities which individually are of no litt... more Although somatostatin itself has numerous inhibitory activities which individually are of no little therapeutic interest, there are also several types of physiological effects where it might be of even greater basic and medical value to block activity instead. Perhaps principal among these would be an ability to block the inhibitory effects of somatostatin on growth hormone (GH) release. Antibody experiments (1) have clearly shown that basal GH levels are elevated when somatostatin is neutralized. There is also an unwanted negative participation of somatostatin when GH levels are stimulated with the GH-releasing factor, GRF. In fact, one group has actually been able to demonstrate that GRF(1–44) stimulates somatostatin release from hypothalamic cells in culture (2). It should also be mentioned that both GH (3) and somatostatin (4) can alter somatostatin levels. Somatomedin C has also been implicated in the negative feedback regulation of GH, at least partially by stimulating release of somatostatin (5). Given the successes which have been achieved in the development of very potent competitive antagonists of other peptides, notably in our own experience with LH-RH, there appears to be no reason to neglect the development of a somatostatin antagonist any longer.
Steroids affect many tissues, including the brain. In the zebra finch, the estrogenic steroid est... more Steroids affect many tissues, including the brain. In the zebra finch, the estrogenic steroid estradiol (E2) is especially effective at promoting growth of the neural circuit specialized for song. In this species, only the males sing and they have a much larger and more interconnected song circuit than females. Thus, it was surprising that the gene for 17beta-hydroxysteroid dehydrogenase type 4 (HSD17B4), an enzyme that converts E2 to a less potent estrogen, had been mapped to the Z sex chromosome. As a consequence, it was likely that HSD17B4 was differentially expressed in males (ZZ) and females (ZW) because dosage compensation of Z chromosome genes is incomplete in birds. If a higher abundance of HSD17B4 mRNA in males than females was translated into functional enzyme in the brain, then contrary to expectation, males could produce less E2 in their brains than females. Here, we used molecular and biochemical techniques to confirm the HSD17B4 Z chromosome location in the zebra finch...
... POST NATAL LECITHOTROPH: A NEW AGE CLASS IN THE ONTOGENY OF REPTILESVALENTINE A. LANCE1, AND ... more ... POST NATAL LECITHOTROPH: A NEW AGE CLASS IN THE ONTOGENY OF REPTILESVALENTINE A. LANCE1, AND DAVID J. MORAFKA2 'Center for Reproduction of Endangered Species, PO. ... The decision to ger-minate or hatch is a bet with high stakes". ...
Neonatal reptiles are here defined as an age class of young eureptilian amniotes (excluding birds... more Neonatal reptiles are here defined as an age class of young eureptilian amniotes (excluding birds) that express attributes most influenced by the pre-paritive development environ- ment (oviduct, egg, and egg nest) and by the demands of parition and first dispersal. Neonatal character states are typically transformed, reduced, or eliminated during the first 10% of their pre- reproductive development. Traditionally, neonates have not been distinguished from juvenile rep- tiles. As a result the neonatology of reptiles has rarely been addressed in past literature. Recent studies reveal a complex array of developmental scenarios involving character state transformations, heterochrony, unique character states in morphology, behavior, physiology, nutrition, dispersion and health. Unique morphological features (such as egg teeth) and limited skeletal ossification charac- terize many neonates. Distinguishing behaviors include "reversal" movements, utilization of bright color patterns, and startling movements with both serving as anti-predation mechanisms. Prolonged association with protective parents, group migration, unique agonistic behavior, and tendencies to- ward rapid dispersion characterize the neonates of individual species. Neonatal physiological attri- butes include: a special availability to inoculation by symbiont fermenting anaerobes in herbivores, rapid conforming responses to their external environments in thermal and hydric exchanges, and in the case of some turtles, extraordinary capacities for supercooling (8.9 C). Post-paritive lecithotrophy (nutrition from residual yolk) sustain both the overwintering of nestlings and the dispersion of non- feeding young for as long as several months. Resistance to infections (such as mycoplasmas) from their maternal parents, combine with nutritive reserves of residual yolk and a common tendency for rapid dispersion to make neonates attractive candidates for augmentation and translocation programs. Coupled with the practical advantages of maintaining and manipulating small animals in a laboratory environment, these qualities distinguish neonates as particularly useful models for ex- perimentally evaluating the relative apportionment of reproductive resources into greater numbers of offspring or into improved quality/survivorship of individual offspring.
Industrial effluents, when discharged into rivers, may cause deleterious effects on fish and othe... more Industrial effluents, when discharged into rivers, may cause deleterious effects on fish and other aquatic oganisms. In ~e~al: the Narayani River has been receiving efluents from several industries including the Bhrikuti Pulp and Paper Mills. Thus, the main objective of this study was to determine impact of industrial pollution on fish fauna and to estimate the level of the heavy metal content in the tissues in fish from the above river Fish samples were collected from three sites, viz. Site-1 near Devghat, Site-2 at Gaindakot in the mixing zone, and Site-3 nearTriveni, in two seasons, rainy and summer. Fish were separated by species and analyzed for heavy metal content using atomic absorption spectrophotometry. The results of fish collections from three sites showed that the number of fish species was less in the polluted area i.e. at Site-2, located near the factory outlet. Chemical analysis of the tissues of fish showed that heavy metals were present in the order of Zn>Cu>C...
Advances in Experimental Medicine and Biology, 1985
Although somatostatin itself has numerous inhibitory activities which individually are of no litt... more Although somatostatin itself has numerous inhibitory activities which individually are of no little therapeutic interest, there are also several types of physiological effects where it might be of even greater basic and medical value to block activity instead. Perhaps principal among these would be an ability to block the inhibitory effects of somatostatin on growth hormone (GH) release. Antibody experiments (1) have clearly shown that basal GH levels are elevated when somatostatin is neutralized. There is also an unwanted negative participation of somatostatin when GH levels are stimulated with the GH-releasing factor, GRF. In fact, one group has actually been able to demonstrate that GRF(1–44) stimulates somatostatin release from hypothalamic cells in culture (2). It should also be mentioned that both GH (3) and somatostatin (4) can alter somatostatin levels. Somatomedin C has also been implicated in the negative feedback regulation of GH, at least partially by stimulating release of somatostatin (5). Given the successes which have been achieved in the development of very potent competitive antagonists of other peptides, notably in our own experience with LH-RH, there appears to be no reason to neglect the development of a somatostatin antagonist any longer.
Uploads
Papers