Interactions between TGF-beta1 and TGF-beta3 and their role in medial edge epithelium cell death and palatal fusion in vitro

In recent decades, studies have shown that both TGF-beta(1) and TGF-beta(3) play an important role in the induction of medial edge epithelium (MEE) cell death and palatal fusion. Many of these experiments involved the addition or blockage of one of these growth factors in wild-type (WT) mouse palate cultures, where both TGF-beta(1) and TGF-beta(3) are present. Few studies have addressed the existence of interactions between TGF-beta(1) and TGF-beta(3), which could modify their individual roles in MEE cell death during palatal fusion. We carried out several experiments to test this possibility, and to investigate how this could influence TGF-beta(1) and TGF-beta(3) actions on MEE cell death and palatal shelf fusion. We double-immunolabelled developing mouse palates with anti-TGF-beta(1) or anti-TGF-beta(3) antibodies and TUNEL, added rhTGF-beta(1) or rhTGF-beta(3) or blocked the TGF-beta(1) and TGF-beta(3) action at different concentrations to WT or Tgf-beta(3) null mutant palate cultures, performed in situ hybridizations with Tgf-beta(1) or Tgf-beta(3) riboprobes, and measured the presence of TUNEL-positive midline epithelial seam (MES) cells and MES disappearance (palatal shelf fusion) in the different in vitro conditions. By combining all these experiments, we demonstrate great interaction between TGF-beta(1) and TGF-beta(3) in the developing palate and confirm that TGF-beta(3) has a more active role in MES cell death than TGF-beta(1), although both are major inductors of MES disappearance. Finally, the co-localization of TGF-beta(1), but not TGF-beta(3), with TUNEL in the MES allows us to suggest a possible role for TGF-beta(1) in MES apoptotic clearance.

Alteration of medial-edge epithelium cell adhesion in two Tgf-beta3 null mouse strains

Although palatal shelf adhesion is a crucial event during palate development, little work has been carried out to determine which molecules are responsible for this process. Furthermore, whether altered palatal shelf adhesion causes the cleft palate presented by Tgf-β₃ null mutant mice has not yet been clarified. Here, we study the presence/distribution of some extracellular matrix and cell adhesion molecules at the time of the contact of palatal shelves in both wild-type and Tgf-β₃ null mutant palates of two strains of mice (C57/BL/6J (C57), and MF1) that develop cleft palates of different severity. We have performed immunohistochemistry with antibodies against collagens IV and IX, laminin, fibronectin, the α₅- and β₁-integrins, and ICAM-1; in situ hybridization with a Nectin-1 riboprobe; and palatal shelf cultures treated or untreated with TGF-β₃ or neutralizing antibodies against fibronectin or the α₅-integrin. Our results show the location of these molecules in the wild-type mouse medial edge epithelium (MEE) of both strains at the time of the contact of palatal shelves; the heavier (C57) and milder (MF1) alteration of their presence in the Tgf-β₃ null mutants; the importance of TGF-β₃ to restore their normal pattern of expression; and the crucial role of fibronectin and the α₅-integrin in palatal shelf adhesion. We thus provide insight into the molecular bases of this important process and the cleft palate presented by Tgf-β₃ null mutant mice.

Spanish validation of the HIV dementia scale in women

HIV infection is increasing in minority groups, particularly in African American and Hispanic women. Although the incidence of HIV dementia has decreased since the advent of highly active antiretroviral treatment, prevalence of neurocognitive complications has increased as patients are now living longer. This study's purpose was to determine the psychometric properties of the Spanish-language HIV Dementia Scale (HDS) in a group of HIV-infected women. We recruited 96 women: 60 HIV-seropositive and 36 HIV-seronegative. Modification of the HDS into a Spanish-language version consisted of translating the instructions, substituting four words in Spanish (gato, media, azul, piña), increasing 1 second in the psychomotor speed because the Spanish alphabet has more letters than the English alphabet, and not offering clues for memory recall. Cognitive impairment (CI) was defined according to the modified American Academy of Neurology HIV-dementia criteria including an asymptomatic CI group. Statistical analysis consisted of analysis of variance to determine group differences and receiver operator characteristics (ROC) to determine the optimal cutoff point for the screening of CI. HDS-Spanish total score and subscores for psychomotor speed and memory recall showed significant differences between HIV-seronegative and women with HIV-dementia (p < 0.001) and between HIV-seropositive women with normal cognition and those with HIV-dementia (p < 0.001). The optimal cutoff point of 13 or less had performance characteristics of 87% sensitivity and 46% specificity for HIV-associated CI (50.0% positive predictive value, 85.0% negative predictive value). The HDS-Spanish translation offers a useful screening tool with value for the identification of Hispanic women at risk of developing HIV-associated symptomatic neurocognitive disturbances.

Differential distribution of antibodies to different viruses in young animals in the free-ranging rhesus macaques of Cayo Santiago

BACKGROUND

The breeding colony of free-ranging rhesus macaques was established in 1938 in Cayo Santiago (CS) with animals collected in northern India. The seroprevalence to cercopithecine herpesvirus type 1 (B virus) and simian retroviruses has been studied previously.

RESULTS

This is the first report on the seropositivity to different viruses using samples collected shortly after removing animals (n = 245) from CS. All samples were negative for measles, simian immunodeficiency virus and simian type D retroviruses. The overall prevalence of antibodies was around 50% for simian T-lymphotropic virus I (STLV-I). For B virus, the prevalence was 38%.

CONCLUSIONS

Data obtained showed marked differences in the antibody distribution to B virus and STLV-I within the free-ranging colony of rhesus macaques. Implication of these data for the Specific Pathogen Free program at the Caribbean Primate Research Center are also discussed.

Stress-induced germ cell apoptosis by a p53 independent pathway in Caenorhabditis elegans

In Caenorhabditis elegans, several distinct apoptosis pathways have been characterized in the germline. The physiological pathway is though to eliminate excess germ cells during oogenesis to maintain gonad homeostasis and it is activated by unknown mechanisms. The DNA damage-induced germ cell apoptosis occurs in response to genotoxic agents and involves the proteins EGL-1 and CED-13, and the DNA damage response protein p53. Germ cell apoptosis can also be induced in response to pathogen infection through an EGL-1 dependent pathway. To gain insight into the mechanism and functions of germ cell apoptosis, we investigated whether and how other forms of stress induce this cell death. We found that oxidative, osmotic, heat shock and starvation stresses induce germ cell apoptosis through a p53 and EGL-1 independent pathway. We also learned that the MAPK kinases MEK-1 and SEK-1, and the p53 antagonist protein ABL-1, are essential for stress-induced germ cell apoptosis. We conclude that in C. elegans responses to various stresses that do not involve genotoxicity include an increase in germ cell apoptosis through the physiological pathway.

Attitudes toward animal research among psychology students in Spain

Animal research plays a central role in psychology, and its use, prevalence and quality depends on the attitudes of students who enter psychology in Spain. Attitudes among psychology students about the use of laboratory animals are not known, so the aim of this work was to analyze the attitudes of Spanish psychology students toward animal research. An attitude questionnaire of 15 items was given to 661 undergraduate students of the School of Psychology at the University of Málaga, Spain. Several results were found: (a) 65.7% of the respondents strongly agreed or agreed with animal research. General support for animal research was significantly higher by men than by women. (b) Support for animal research was higher for senior students, suggesting that the psychology curriculum or self-selection to remain in the program might influence students' attitudes. (c) Attitudes toward animal research were similar among students independent of the type of animal being used for research in biological or psychological studies. (d) 58% considered that laboratory animals never or almost never are inappropriately handled. (c) 55.6% indicated that research in psychology on animals could be generalized to humans. Overall, these results suggest that among Spanish psychology students animals research is considered important for the advancement of the science. Likewise, a majority of students displayed positive attitudes toward animal research.

Amarisolide monohydrate, a 2-(beta-glucosyl)neoclerodane

The absolute configuration of the neoclerodane glycoside amarisolide, presented here as the monohydrate, C26H36O9*H2O, has been determined by association with the known configuration of the glucose moiety. Its structure was established as 2beta-(O-beta-D-glucopyranosyl)neocleroda-3,13(16),14-trien-15,16-epoxy-18,19-olide. Extensive hydrogen bonding among the hydroxyl groups of the sugar moiety forms layers which are interconnected by water molecules.

MDMA ("ecstasy") exhibits an anxiogenic-like activity in social encounters between male mice

Recent studies have suggested that 3,4-methylenedioxymethamphetamine (MDMA; "ecstasy"), a synthetic amphetamine derivative, might exhibit an anxiogenic-like activity in rodents. In this work, we examined the effects of MDMA (1, 8 and 15 mg kg(-1), i.p.) on social encounters between male mice using an ethopharmacological approach. Likewise, we compared the behavioural profile of MDMA with that induced by FG 7142 (15 mg kg(-1), i.p.), an anxiogenic benzodiazepine receptor ligand. Individually housed mice were exposed to anosmic standard opponents 30 min after drug administration, and the encounters were videotaped and evaluated using an ethologically based analysis. MDMA (8 and 15 mg kg(-1)) produced a behavioural pattern characterized by a marked decrease of aggression (threat and attack) as well as social investigation, body care and digging behaviours, without affecting immobility. Moreover, avoidance/flee and defence/submission behaviours were significantly increased by the drug. A very similar behavioural profile was observed in FG 7142-treated animals. Overall, these findings might indicate that MDMA has anxiogenic-like properties in male mice.

Pathogenesis of Histoplasma capsulatum

Histoplasma capsulatum is well adapted to be infectious and pathogenic for humans. As a soil fungus with no known requirement for interacting with a mammalian host as part of an obligate lifecycle, its plethora of strategies for successful pathogenesis is particularly remarkable. These features include the dimorphic mold-yeast transition, entry into host macrophages, subcellular localization, intracellular survival and proliferation during active infection, and persistence during clinically inapparent infection with the capacity for reactivation. To thrive within the harsh environment of a professionally phagocytic and antimicrobial host cell, H. capsulatum displays mechanisms for modulating its microenvironmental pH level, resisting host reactive oxygen and nitrogen intermediates and degradative enzymes, and withstanding nutrient starvation conditions, including acquisition of iron and calcium and biosynthesis of nucleic acid precursors. Attention has been focused on identifying virulence-associated phenotypic traits and genes that are differentially expressed under relevant conditions, such as yeast morphotype-specific genes and genes that are up-regulated during infection. These studies, together with the increasing ability to perform molecular genetic manipulations in this fungus, may yield novel antifungal drug or vaccine targets as well as elucidating pathogenic mechanisms.

An RNA polymerase II complex containing capping enzymes and viral oncoproteins

The aim of this work was to identify proteins from Adenovirus 2-infected HeLa cell extracts that interact with the carboxyl-terminal domain of the largest subunit of RNA polymerase II. First, a mammalian RNA polymerase II complex was isolated from Adenovirus 2-infected HeLa cell extracts by affinity chromatography against the carboxyl-terminal domain of the largest subunit of RNA polymerase II, followed by chromatography on a Mono S fast protein liquid chromatographic column. Second, the isolated complex was further characterized by Western blot analysis, the formation of a GMP-protein complex, and transcriptional activity. The isolated complex contains general transcription factors, chromatin-remodeling factors, histone acetyltransferases, Srbs, capping enzymes, and E1A viral oncoproteins. The RNA polymerase II complex is active in transcription when supplemented with recombinant transcription factor IIB.

Effects of 3,4-methylenedioxy-methamphetamine (MDMA) on anxiety in mice tested in the light-dark box

1. The effects of acute administration of 3,4-methylenedioxymethamphetamine (MDMA; "ecstasy") on anxiety tested in the light/dark box were examined in albino male mice of the OF.1 strain. 2. Animals were evaluated in the light/dark test 30 min after injection of MDMA (1, 8, and 15 mg/kg, i.p) or saline. The following parameters were recorded (for 5 min); (a) number of exploratory rearings in the light and dark sections; (b) number of transitions between the lit and dark areas; (c) time spent in the light and dark areas; (d) latency of the initial movement from the light to the dark area, and (e) locomotor activity in light area. 3. MDMA (8 and 15 mg/kg) produced a significant reduction in exploratory activity (rearings and transitions), without decreasing motility, in comparison with saline-treated mice. However, time spent in lit/dark compartments was not significantly affected by the drug, which could be a consequence of the anti-exploratory properties of MDMA. 4. Overall, the behavioral profile found in the light/dark test indicates an anxiogenic-like activity of MDMA in mice. It is suggested, however, that animal models of anxiety which emphasize a social interaction could be more sensitive to the effects of this substance.

Effects of N6-cyclohexyl adenosine (CHA) on isolation-induced aggression in male mice

Several studies have suggested adenosine receptor involvement in the modulation of aggressive behavior; however, the influence of adenosine A1 agonists on aggression is scarcely known. In this study, we examined the effect of N6-cyclohexyl adenosine (CHA; 0.025-0.4 i.p.), a selective adenosine A1 receptor agonist, on agonistic behavior elicited by isolation in male mice. Individually housed mice were exposed to anosmic standard opponents 60 min after drug administration, and the encounters were videotaped and evaluated using an ethologically based analysis. CHA exhibited an ethopharmacological profile characterized by a selective decrease of offensive behaviors (threat and attack) at the intermediate dose (0.1 mg/kg), without impairment of motor activity. In contrast, the antiaggressive action of the highest doses used (0.2 and 0.4 mg/kg) was accompanied by a marked increase of immobility. It is concluded that the behavioral effects observed in this study could be related to an adenosine modulatory action on other neurotransmitter systems (dopamine/serotonin).

Polystachynes A-E, five cis-neo-clerodane diterpenoids from Salvia polystachya

From the aerial parts of Salvia polystachya five new neo-clerodane diterpenoids, polystachynes A-E, have been isolated. The structures were established by spectroscopic methods, including the X-ray analysis of polystachynes C and D. The known clerodanes salvifaricin, linearolactone and dehydrokerlin were also isolated.

Behavioral profile of quinpirole in agonistic encounters between male mice

Most neuroleptic drugs that act as dopaminergic D2 receptor antagonists are effective antiaggressive agents. Although the action of D2 antagonists on aggression has been extensively documented, little is known about the influence of D2 agonists. This study was designed to examine the effect of quinpirole (0.2, 0.4 and 0.8 mg/kg i.p.), a potent agonist at D2 receptors,on agonistic behavior elicited by isolation in male mice. Individually housed mice were exposed to anosmic standard opponents 30 min after drug administration and encounters were videotaped and evaluated using an ethologically based analysis. Quinpirole exhibited an ethopharmacological profile characterized by a selective decrease in offensive behaviors (threat and attack) at low doses (0.2 mg/kg) without affecting motility or exploratory behaviors. This action could be related to the activation of presynaptic D2 receptors. In contrast, at higher doses (0.8 mg/kg), this drug produced a behavioral pattern defined by a significant increase in defense/submission and avoidance/fleeing as well as a reduction in digging and social investigation behaviors suggesting that it could also show anxiogenic-like properties.

Crystal structure of triosephosphate isomerase from Trypanosoma cruzi in hexane

To gain insight into the mechanisms of enzyme catalysis in organic solvents, the x-ray structure of some monomeric enzymes in organic solvents was determined. However, it remained to be explored whether the structure of oligomeric proteins is also amenable to such analysis. The field acquired new perspectives when it was proposed that the x-ray structure of enzymes in nonaqueous media could reveal binding sites for organic solvents that in principle could represent the starting point for drug design. Here, a crystal of the dimeric enzyme triosephosphate isomerase from the pathogenic parasite Trypanosoma cruzi was soaked and diffracted in hexane and its structure solved at 2-A resolution. Its overall structure and the dimer interface were not altered by hexane. However, there were differences in the orientation of the side chains of several amino acids, including that of the catalytic Glu-168 in one of the monomers. No hexane molecules were detected in the active site or in the dimer interface. However, three hexane molecules were identified on the surface of the protein at sites, which in the native crystal did not have water molecules. The number of water molecules in the hexane structure was higher than in the native crystal. Two hexanes localized at <4 A from residues that form the dimer interface; they were in close proximity to a site that has been considered a potential target for drug design.

Transcriptional functions of a new mammalian TATA-binding protein-related factor

A mammalian protein highly homologous to TATA-binding protein (TBP) has been identified and cloned. The recombinant mammalian TBP-related factor binds to the TATA box of the Ad-MLP and forms stable complexes with TFIIB on the promoter DNA. The mammalian TBP-related factor is able to substitute for TBP in supporting transcription by RNA polymerase II in an in vitro reconstituted system.

Derivatization of the interface cysteine of triosephosphate isomerase from Trypanosoma brucei and Trypanosoma cruzi as probe of the interrelationship between the catalytic sites and the dimer interface

In the interface of homodimeric triosephosphate isomerase from Trypanosoma brucei (TbTIM) and Trypanosoma cruzi (TcTIM), one cysteine of each monomer forms part of the intersubunit contacts. The relatively slow derivatization of these cysteines by sulfhydryl reagents induces progressive structural alterations and abolition of catalysis [Garza-Ramos et al. (1998) Eur. J. Biochem. 253, 684-691]. Derivatization of the interface cysteine by 5, 5-dithiobis(2-nitrobenzoate) (DTNB) and methylmethane thiosulfonate (MMTS) was used to probe if events at the catalytic site are transmitted to the dimer interface. It was found that enzymes in the active catalytic state are significantly less sensitive to the thiol reagents than in the resting state. Maximal protection against derivatization of the interface cysteine by thiol reagents was obtained at near-saturating substrate concentrations. Continuous recording of derivatization by DTNB showed that catalysis hinders the reaction of sulfhydryl reagents with the interface cysteine. Therefore, in addition to intrinsic structural barriers, catalysis imposes additional impediments to the action of thiol reagents on the interface cysteine. In TcTIM, the substrate analogue phosphoglycolate protected strongly against DTNB action, and to a lesser extent against MMTS action; in TbTIM, phosphoglycolate protected against the effect of DTNB, but not against the action of MMTS. This indicates that barriers of different magnitude to the reaction of thiol reagents with the interface cysteine are induced by the events at the catalytic site. Studies with a Cys14Ser mutant of TbTIM confirmed that all the described effects of sulfhydryl reagents on the trypanosomal enzymes are a consequence of derivatization of the interface cysteine.