Downregulation of ATM Gene and Protein Expression in Canine Mammary Tumors.

The ataxia telangiectasia mutated (ATM) gene encodes a protein associated with DNA damage repair and maintenance of genomic integrity. In women, ATM transcript and protein downregulation have been reported in sporadic breast carcinomas, and the absence of ATM protein expression has been associated with poor prognosis. The aim of this study was to evaluate ATM gene and protein expression in canine mammary tumors and their association with clinical outcome. ATM gene and protein expression was evaluated by reverse transcription-quantitative polymerase chain reaction and immunohistochemistry, respectively, in normal mammary gland samples (n = 10), benign mammary tumors (n = 11), nonmetastatic mammary carcinomas (n = 19), and metastatic mammary carcinomas (n = 11). Lower ATM transcript levels were detected in benign mammary tumors and carcinomas compared with normal mammary glands (P = .011). Similarly, lower ATM protein expression was observed in benign tumors (P = .0003), nonmetastatic mammary carcinomas (P < .0001), and the primary sites of metastatic carcinomas (P < .0001) compared with normal mammary glands. No significant differences in ATM gene or protein levels were detected among benign tumors and nonmetastatic and metastatic mammary carcinomas (P > .05). The levels of ATM gene or protein expression were not significantly associated with clinical and pathological features or with survival. Similar to human breast cancer, the data in this study suggest that ATM gene and protein downregulation is involved in canine mammary gland tumorigenesis.

The role of the immunological background of mice in the genetic variability of Schistosoma mansoni as detected by random amplification of polymorphic DNA.

Schistosomiasis is a parasitic disease caused by flatworms of the genus Schistosoma. Among the Schistosoma species known to infect humans, S. mansoni is the most frequent cause of intestinal schistosomiasis in sub-Saharan Africa and South America: the World Health Organization estimates that about 200,000 deaths per year result from schistosomiasis in sub-Saharan Africa alone. The Schistosoma life cycle requires two different hosts: a snail as intermediate host and a mammal as definitive host. People become infected when they come into contact with water contaminated with free-living larvae (e.g. when swimming, fishing, washing). Although S. mansoni has mechanisms for escaping the host immune system, only a minority of infecting larvae develop into adults, suggesting that strain selection occurs at the host level. To test this hypothesis, we compared the Belo Horizonte (BH) strain of S. mansoni recovered from definitive hosts with different immunological backgrounds using random amplification of polymorphic DNA-polymerase chain reaction (RAPD-PCR). Schistosoma mansoni DNA profiles of worms obtained from wild-type (CD1 and C57BL/6J) and mutant (Jα18- / - and TGFßRIIdn) mice were analysed. Four primers produced polymorphic profiles, which can therefore potentially be used as reference biomarkers. All male worms were genetically distinct from females isolated from the same host, with female worms showing more specific fragments than males. Of the four host-derived schistosome populations, female and male adults recovered from TGFßRIIdn mice showed RAPD-PCR profiles that were most similar to each other. Altogether, these data indicate that host immunological backgrounds can influence the genetic diversity of parasite populations.

Diagnosis of schistosomiasis by reagent strip test for detection of circulating cathodic antigen.

A newly developed reagent strip assay for the diagnosis of schistosomiasis based on parasite antigen detection in urine of infected individuals was evaluated. The test uses the principle of lateral flow through a nitrocellulose strip of the sample mixed with a colloidal carbon conjugate of a monoclonal antibody specific for Schistosoma circulating cathodic antigen (CCA). The strip assay to diagnose a group of highly infected schoolchildren in Mwanza, Tanzania, demonstrated a high sensitivity and association with the intensity of infection as measured both by egg counts, and by circulating anodic antigen and CCA levels determined by enzyme-linked immunosorbent assay. A specificity of ca. 90% was shown in a group of schistosome-negative schoolchildren from Tarime, Tanzania, an area where schistosomiasis is not endemic. The test is easy to perform and requires no technical equipment or special training. The stability of the strips and the conjugate in the dry format lasts for at least 3 months at ambient temperature in sealed packages, making it suitable for transport and use in areas where schistosomiasis is endemic. This assay can easily be developed to an end-user format.

[The determination of susceptibility to measles, rubella, mumps and chickenpox in students of health-related areas]. / Determinação da susceptibilidade ao sarampo, rubéola, papeira e varicela nos estudantes das áreas ligadas à saúde.

We present an epidemiological and serological study in 286 health care students. We found susceptibility for measles in 11.7% individuals (95% confidence interval (95% CI): 8.0-15%), for rubella: 6.7% (95% CI: 3.8-9.6%) for mumps: 12.7% (95% CI: 8.0-16.6%) and for varicella 8.5% (95% CI: 5.3-11.7%). Compared to a similar study, performed in 1992 in a population of health care workers, we found an increasing susceptibility to these diseases except for mumps, that had decreased. Among those who received one dose of measles vaccine we found 12.1% non immune. We found an high level of immunity (97.1%) for those who received rubella vaccination. We could not draw any conclusions for mumps because only seven had been vaccinated.

New pathway of heparan sulphate degradation. Iduronate sulphatase and N-sulphoglucosamine 6-sulphatase act on the polymer chain prior to depolymerisation by a N-sulpho-glucosaminidase and glycuronidases in the mollusc Tagelus gibbus.

It has previously been shown that in the mollusc Anomalocardia brasiliana the desulphation of chondroitin sulphate precedes its depolymerisation by beta-glucuronidase and beta-N-acetylgalactosaminidase (Sousa Jr. et al. J. Biol. Chem. 1990;265:20150-20155). This led us to investigate whether in molluscs, sulphatases also act on heparan sulphate before its depolymerisation by glycosidases. Radioactively labelled [35S]heparan sulphate was extensively degraded by enzyme extracts prepared from the mollusc Tagelus gibbus. Several enzymes acting in concert degrade the compound to inorganic sulphate, glucosamine N-sulphate, N-acetylglucosamine-6 sulphate and other oligosaccharide products. These results indicate the presence of iduronate sulphatase, N-sulphoglucosamine 6-sulphatase alpha-N-sulphoglucosaminidase, beta-glucuronidase and alpha-L-iduronidase. The di- and mono-saccharide composition of the oligosaccharides were analysed with the aid of heparitinase II from Flavobacterium heparinum. These analyses led to the characterisation of two sulphatases that act on the polymer chain removing sulphates from the C-2 position of iduronic acid residues and the C-6 position of the glucosamine moieties, respectively. The different enzymes were partially fractionated by ion exchange chromatography and molecular sieving. These results led to the proposition of a new pathway of degradation of heparan sulphate where sulphatases act directly on the polymer chain which is then depolymerised by several glycosidases.

Sequencing of heparan sulfate proteoglycans: identification of variable and constant oligosaccharide regions in eight heparan sulfate proteoglycans of different origins.

The sequence of the disaccharide units of eight heparan sulfate proteoglycans of different origins is described. All heparan sulfates contain 5 variable regions made of oligosaccharide blocks of disaccharides, namely, GlcUA(1-4)GlcNAc, GlcUA(1-4)GlcNS, IdoUA (1-4) GlcNS,6S,IdoUA-GlcNAc,6S, and IdoUA,2S(1-4)GlcNS,6S, besides two constant regions made of an internal tetrasaccharide (IdoUA-GlcNAc-IdoUA-GlcNS) and monosaccharides (GlcNS, and GlcNS,6S) at the non-reducing terminal. The N-acetylated region of the heparan sulfates is linked to the serine of the protein core through a trisaccharide of Xyl-Gal-Gal. Heparan sulfates differ from one another in terms of the number of disaccharides that compose each block.

Sequencing of heparan sulfate proteoglycans: identification of variable and constant oligosaccharide regions in eight heparan sulfate proteoglycans of different origins

The sequence of the disacharide units of eight heparan sulfate proteoglycans of different origins is described. All heparan sulfates contain 5 variable regions made of oligosaccharide blocks of disaccharides, namely GlcUA(1-4) GlcNAc, GlcUA(1-4)GlcNS, IdoUA (104)GlcNS) and monosaccharides (GlcNS, and GlcNS,65) at the non-reducing terminal. The N-acetylated region of the heparan sulfates is linked to the serine of the protein core through a trisaccharide of Xyl-Gal-Gal. Heparan sulfates differ from one another in terms of the number of disaccharides that compose each block

Structure of heparan sulfate from the fresh water mollusc Anomantidae sp: sequencing of its disaccharide units.

1. The disaccharide sequences of a heparan sulfate isolated from Anomantidae sp. was determined with the aid of heparitinase I, heparitinase II from Flavobacterium heparinum, mollusc beta-glucuronidase and alpha-N-acetylglucosaminidase besides nitrous acid degradation and chemical analyses. 2. Like the mammalian heparan sulfates the mollusc heparan sulfate is composed of different oligosaccharide blocks of N-acetylated disaccharides, N-sulfated disaccharides and N,6-sulfated disaccharides and has in its nonreducing end the monosaccharide glucosamine 2,6-disulfate. 3. The oligosaccharides produced by heparitinase I degradation contain at their reducing ends a N-acetylated, 6-sulfated disaccharide. 4. These and other results lead to the conclusion that the general structure of the heparan sulfate is maintained through evolution.

Reversal of the increase in apomorphine-induced stereotypy and aggression in REM sleep deprived rats by dopamine agonist pretreatments.

REM sleep deprivation (REMSD) induces augmented responses to dopaminergic agonists. Prolonged administration of neuroleptics induces a similar state, probably by the production of supersensitivity of dopaminergic receptors. Such a supersensitive state could be induced by REMSD as a result of impairment of dopamine neurotransmission. In order to test this hypothesis, bromocriptine, nomifensine, amphetamine, L-dopa, imipramine and electroconvulsive shock (ECS) were administered to rats during REMSD, and aggressive and stereotyped behaviors were measured. Amphetamine and L-dopa pretreatment attenuated the increases in apomorphine-induced stereotypy and aggression in REMSD rats, but ECS selectively reduced apomorphine-induced aggression. The other drugs tested were ineffective on both behavioral tests. Such a selective action may reflect different effects of ECS on different dopaminergic systems such as those involved with stereotypy and aggression. The results suggest that REMSD induces an increase in dopaminergic sensitivity which may be reversed by pretreatment with some dopaminergic agonists.

Pharmacology of lemongrass (Cymbopogon citratus Stapf). II. Effects of daily two month administration in male and female rats and in offspring exposed "in utero".

An infusion (abafado) prepared from leaves of lemongrass (Cymbopogon citratus Stapf) administered orally to adult rats for 2 months, in doses up to 20 times larger than the estimated corresponding human dosage, did not induce any effect which could be taken as evidence of toxicity. An absence of effects was also noted in male and female rats and in their offspring when the abafado was administered prior to mating or during pregnancy. These data strongly suggest that lemongrass, as used in Brazilian folk medicine, has no toxic properties.

Isolation and structural studies of heparan sulfates and chondroitin sulfates from three species of molluscs.

The isolation and some structural features of heparan sulfates and chondroitin sulfates from three species of molluscs (Pomacea sp., Tagelus gibbus, and Anomalocardia brasiliana) are reported. It is shown that heparan sulfates with structural similarities to the ones found in mammals are present in the three molluscs analyzed. All the heparan sulfates were degraded by heparitinases I and II to four distinct unsaturated disaccharides with the same properties as the ones present in heparan sulfates of mammalian origin. This suggests that these four disaccharide units are maintained through the evolution. Furthermore, the proportion of these units varied in the heparan sulfates according to the species of origin. The chondroitin sulfates, on the other hand, exhibit different structural features according to the species of origin. For instance, by the action of chondroitinase AC, 4- and nonsulfated disaccharides are produced from Pomacea chondroitin, whereas 4- and 6-sulfated disaccharides are formed from Tagelus and Anomalocardia. The possible role of these compounds in cell recognition and/or adhesiveness is discussed in view of the present findings.