Noble PRST-1 Ca prostate adenocarcinoma study on noble rats: preliminary study on new androgen sensitive tumor

The Nb rat prostatic adenocarcinoma model has served as an animal model for testing various chemotherapeutic agents. Herein this preliminary report, the tumor Nb PRST-1 Ca was evaluated in 25 animals with testosterone, dihydrotestosterone, orchiectomized and control treatments. Tumor growth curves were determined and show a significant difference on day 13 (T-test) between the control group and treatment groups. Metastases were found in the lungs of all animals and a remarkable rounding of the liver was noted in the androgen treatment groups.     

A new species of <Emphasis Type="Italic">Petasiger</Emphasis> (Digenea,Echinostomatidae) parasitizing <Emphasis Type="Italic">Podiceps major</Emphasis> and <Emphasis Type="Italic">Rollandia rolland</Emphasis> (Aves,Podicipedidae) from Buenos Aires Province,Argentina

Petasiger argentinensis sp. nov. is described from material found in the intestine of the Great Grebe, Podiceps major (Boddaert) and the White-tufted Grebe, Rollandia rolland Quoy et Gaimard (Podicipediformes, Podicipedidae), from Argentina. The new species is characterized by the head collar armed with 19 spines and by the testes arranged in tandem. These characters are shared with only two Neotropical species of the genus, P. novemdecim Lutz, 1928 and P. combesi Zamparo, Overstreet et Brooks, 2005. Petasiger novemdecim differs from the new species in having a larger body, longer collar spines, larger eggs, a cirrus-sac of similar size to the ventral sucker and almost entirely anterior to it, and vitelline fields confluent ventrally posterior to the ventral sucker. P. combesi differs from the new species in most metrical characters, the shape of the body (antero-posteriorly elongate) and the location of the genital pore (dextral) and the excretory pore (dorsal). This is the first record of a member of the genus Petasiger parasitizing birds from Argentina.     

Conservation of behavioural topography to dopamine D1-like receptor agonists in mutant mice lacking the D1A receptor implicates a D1-like receptor not coupled to adenylyl cyclase.

Though D1-like dopamine receptors [D1A/B] are defined in terms of linkage to the stimulation of adenylyl cyclase, with D1A assumed to be the functionally prepotent subtype, evidence suggests the existence of another, novel D1-like receptor without such coupling. To investigate these issues we challenged mutant mice having targeted gene deletion of the D1A receptor with selective agonists and used an ethologically-based assessment technique to resolve resultant behavioural topography. D1-like-dependent behaviour was substantially conserved in D1A-null mice relative to wild-types following challenge with each of two selective D1-like agents: A 68930 (0.068-2.0 mg/kg s.c.) which exhibits full efficacy to stimulate adenylyl cyclase, and SKF 83959 (0.016-2.0 mg/kg s.c.) which fails to stimulate adenylyl cyclase, and indeed inhibits the stimulation of adenylyl cyclase induced by dopamine. Furthermore, responsivity to the selective D2-like agonist RU 24213 (0.1-12.5 mg/kg s.c.) was conserved in D1A-null mice, indicating the integrity of D1-like:D2-like interactions at the level of behaviour. These data are consistent with behavioural primacy of a D1-like receptor other than D1A [or D1B] that is coupled to a transduction system other than/additional to adenylyl cyclase.     

Epistasis between a set of variations located in the TAAR6 and HSP-70 genes toward schizophrenia and response to antipsychotic treatment

Suggestive associations have been reported between trace amines and heat shock proteins, and a disrupted pathophysiology that enhances the risk of psychosis and that modifies responses to antipsychotic treatments. Our group previously reported genetic studies on TAAR6 and HSP-70 separately in patients with schizophrenia. In the current study, we investigated possible epistasis between the same set of variations in a sample of 281 patients diagnosed with schizophrenia and 288 healthy controls. We applied the generalized multifactor dimensionality reduction (MDR) method and controlled covariates significantly associated with both diagnosis and treatment efficacy. To the best of our knowledge, epistasis between the present set of variations in schizophrenia has not been tested before. We found significant associations with both the risk of disease and response to treatment. However, the insufficiently balanced accuracy of the applied tests suggests that, despite significantly different genetic variations between cases and controls, these factors have a poor predictive value. Explanations for these findings and possible future directions are also discussed.     

Colon carcinoma associated with ureterosigmoidostomy

A patient developing a colonic adenoma 38 years following ureterosigmoidostomy is presented. The mechanisms of neoplastic transformation associated with ureterosigmoidostomy is now better understood. This knowledge is being applied to develop modifications both of the surgical technique and the management of patients with this form of urinary diversion, and is a subject of discussion.     

Oxytocin potently enhances novelty-induced grooming behavior in the rat

Intracerebroventricular (i.c.v.) injection of oxytocin was followed by an enhancement of novelty-induced grooming in male and female rats. This effect was dose-dependent, in a dose range of 0.1-10 micrograms. Grooming activity of rats injected i.c.v. with 10 micrograms of oxytocin was 9-fold higher than that of saline-injected controls. The analysis of behavioral element composition revealed an increased occurrence of genital grooming in oxytocin-injected rats. A time-course study revealed a sustained increase in grooming activity of oxytocin-treated rats during 45 min of behavioral testing. Intraperitoneal (i.p.) injection of the dopamine antagonist, haloperidol, totally suppressed oxytocin-enhanced grooming. Furthermore, i.p. injection of the opiate receptor antagonist, naloxone, was followed by an attenuation but not a suppression of grooming enhanced by i.c.v. administration of oxytocin. In addition, a small but significant increase in grooming activity was observed after subcutaneous injection of oxytocin. These results suggest that oxytocin-enhanced grooming behavior involves central mechanisms, e.g. dopamine and opioid transmission in the brain.     

Desenkephalin-gamma-endorphin restores the impaired sensitivity of hypophysectomized rats to small doses of apomorphine

Hypophysectomized male rats, tested 7 days after removal of the pituitary, showed a reduced sensitivity to small doses of apomorphine. In these rats, subcutaneous (s.c.) treatment with apomorphine (25, 100 or 250 micrograms/kg) did not elicit any reduction in locomotor activity measured 5 min after injection in contrast to that observed in sham-operated control rats. The enhancement of locomotor activity and stereotyped behavior, 20 min after the s.c. administration of apomorphine, was similar in hypophysectomized rats and in control animals. Prolactin does not seem to be implicated in this altered sensitivity, since hyperprolactinaemia induced by pituitary homografts under the kidney capsule did not change the response to apomorphine in hypophysectomized rats. Chronic treatment with desenkephalin-gamma-endorphin (DE gamma E), a beta-endorphin fragment with neuroleptic-like properties, administered s.c. twice a day for 7 days at the dose of 10 micrograms/rat, restored the sensitivity to small doses of apomorphine in the hypophysectomized rats. The data suggest that removal of the pituitary leads to impaired sensitivity of presumably presynaptically located dopamine receptors mediating the effects of small doses of apomorphine without altering the sensitivity of postsynaptically located dopamine receptors that mediate the hypermotility and stereotypy induced by apomorphine. This impaired sensitivity to low doses of apomorphine could be restored by DE gamma E but not by prolactin, supporting the conclusions from previous experiments that DE gamma E and prolactin may selectively interfere with pre- and postsynaptic dopamine receptors respectively.     

Depression and Alzheimer's disease: Neurobiological links and common pharmacological targets

Depression is one of the most prevalent and life-threatening forms of mental illnesses, whereas Alzheimer's disease is a neurodegenerative disorder that affects more than 37 million people worldwide. Recent evidence suggests a strong relationship between depression and Alzheimer's disease. A lifetime history of major depression has been considered as a risk factor for later development of Alzheimer's disease. The presence of depressive symptoms can affect the conversion of mild cognitive impairment into Alzheimer's disease. Neuritic plaques and neurofibrillary tangles, the two major hallmarks of Alzheimer's disease brain, are more pronounced in the brains of Alzheimer's disease patients with comorbid depression as compared with Alzheimer's disease patients without depression. On the other hand, neurodegenerative phenomena have been observed in different brain regions of patients with a history of depression. Recent evidence suggests that molecular mechanisms and cascades that underlie the pathogenesis of major depression, such as chronic inflammation and hyperactivation of hypothalamic-pituitary-adrenal (HPA) axis, are also involved in the pathogenesis of Alzheimer's disease. In particular, a specific impairment in the signaling of some neurotrophins such as transforming-growth-factor β1 (TGF-β1) and brain-derived neurotrophic factor (BDNF) has been observed both in depression and Alzheimer's disease. In the present review we will examine the evidence on the common molecular pathways between depression and Alzheimer's disease and we will discuss these pathways as new pharmacological targets for the treatment of both major depression and Alzheimer's disease.     

A new species of <Emphasis Type="Italic">Centrorhynchus</Emphasis> (Acanthocephala,Centrorhynchidae) endoparasite of <Emphasis Type="Italic">Guira guira</Emphasis> (Aves,Cuculidae) from Argentina

Centrorhynchus guira n. sp. is described from the guira cuckoo, Guira guira (Gmelin) (Cuculiformes: Cuculidae), from Argentina. This new species is characterized by the proboscis armament with 32 longitudinal rows (29 with 18 hooks per row and 3 with 19 hooks per row) and by the following hook pattern per row: 8–9 true hooks, 4 transitional hooks with lateral alate processes, and 6 spiniform hooks. The presence of transitional hooks is shared with five other Neotropical species in the genus: C. polymorphus, C. albidus, C. microcephalus, C. kuntzi and C. crotophagicola. Among these species, C. guira n. sp. most closely resembles C. kuntzi in having transitional hooks with lateral alate processes, however differs in the number of hooks per row and spiniform hooks. This is the first record of the genus Centrorhynchus parasitizing Argentinean birds. A key to the species of the Neotropical Centrorhynchus Lühe 1911 is presented.     

The fibrinolytic system in experimental prostate tumor

Hypofibrinogenemia and disseminated intravascular coagulation are common events in patients with metastatic prostate carcinoma. This study tests the hypothesis that prostate tumor growth and metastasis is associated with sustained activation of fibrinolysis secondary to increased release of plasminogen activator. We implanted an androgen-insensitive prostate tumor into an inbred strain of rats and serially measured plasminogen, plasminogen activator, plasmin and fibrinogen. Control groups included animals without tumor and a group implanted with transitional cell bladder carcinoma, a locally infiltrating tumor not usually associated with hemostatic complications. Our results showed a significant and steady rise in plasma plasminogen activator, plasmin and fibrinogen levels in animals implanted with prostate cancer. This, however, is not specific for prostate tumor. Similar, perhaps more profound changes were noted in animals implanted with the transitional cell carcinoma.