Vertical transmission of bovine spongiform encephalopathy prions evaluated in a transgenic mouse model

In this work we show evidence of mother-to-offspring transmission in a transgenic mouse line expressing bovine PrP (boTg) experimentally infected by intracerebral administration of bovine spongiform encephalopathy (BSE) prions. PrP(res) was detected in brains of newborns from infected mothers only when mating was allowed near to the clinical stage of disease, when brain PrP(res) deposition could be detected by Western blot analysis. Attempts to detect infectivity in milk after intracerebral inoculation in boTg mice were unsuccessful, suggesting the involvement of other tissues as carriers of prion dissemination. The results shown here prove the ability of BSE prions to spread centrifugally from the central nervous system to peripheral tissues and to offspring in a mouse model. Also, these results may complement previous epidemiological data supporting the occurrence of vertical BSE transmission in cattle.

Different behavior toward bovine spongiform encephalopathy infection of bovine prion protein transgenic mice with one extra repeat octapeptide insert mutation

In humans, insert mutations within the repetitive octapeptide region of the prion protein gene (Prnp) are often associated with familial spongiform encephalopathies. In this study, transgenic mice expressing bovine PrP (boTg mice) bearing an additional octapeptide insertion to the wild type (seven octapeptide repeats instead of six) showed an altered course of bovine spongiform encephalopathy (BSE) infection, reflected as reduced incubation times when compared with boTg mice expressing similar levels of the wild-type six-octapeptide protein. In both boTg mouse lines (bo6ORTg and bo7ORTg), incubation times were affected drastically depending on transgene expression levels and the inoculum used. In accordance with the lack of an interspecies barrier to BSE infection, we detected the typical signs of CNS spongiform degeneration by histopathological analysis and the presence of the bovine prion PrP(res) by Western blot or immunohistochemical analyses. When 7OR-PrP(res) was propagated in bo7ORTg mice, a similar earlier onset of clinical signs was observed compared with bo6ORTg mice. Proteins PrP(C) and PrP(res) containing seven octapeptides (7OR-PrP(C) and 7OR-PrP(res)) showed similar protease sensitivity and insolubility in nondenaturing detergents to homologous 6OR-PrP(C) and 6OR-PrP(res). In addition, bo7ORTg mice showed a higher sensitivity than bo6ORTg mice for detecting prion infection in specimens previously diagnosed as negative by conventional biochemical techniques. In the absence of clinical signs of disease, 7OR-PrP(res) could be detected as early as 120 d after inoculation by immunohistochemical and Western blot analyses. These findings may help us improve the current mouse bioassays and understand the role of the octapeptide repeat region in susceptibility to disease.

Precise quantitation of steroid 5alpha lambda pi eta alpha-reductase type 1 mRNA levels by RT-PCR in female rat liver

The liver is a multifunctional organ capable of steroid hormone catabolism. The steroid metabolizing enzyme activities have been identified in the liver and it has been demonstrated that neonatal testicular androgens irreversibly program several hepatic enzyme activities in the rat including 5alpha-reductase (5alpha-R). In this paper we have applied a quantitative RT-PCR method coupled to laser-induced fluorescence capillary electrophoresis (LIF-CE) to measure the mRNA levels of 5alpha-R type 1 isozyme (5alpha-R1) in the liver of female intact and ovariectomized rats. Both groups were treated with testosterone (T) to study the possible regulation of 5alpha-R1 by androgens in females and to allow comparison with our previous findings in the liver of male rats. Our results demonstrate that the 5alpha-R1 mRNA isozyme is higher in the liver of female rats than in males and that the regulation of 5alpha-R1 mRNA by T is different in the liver of female than in male rats. Finally, our results could point to hepatic 5alpha-Reductase participation in the female not only in the catabolism of steroids with delta4,5 double bond, but also in other physiological functions such as the production of 3alpha,5alpha-reduced metabolites of progesterone and deoxycorticosterone (DOC), potent allosteric modulators of GABA(A) receptors.

Alcohol intoxication increases allopregnanolone levels in male adolescent humans

RATIONALE

Teenage drinking is a cause of growing concern in industrialized countries, where almost 35% of alcohol drinkers are under 16 years old. Increased anxiety, irritability and depression among adolescents may induce them to seek the anxiolytic and rewarding properties of alcohol. Allopregnanolone is rewarding in rodents, and therefore may contribute to the effects of alcohol.

OBJECTIVE

In this paper, we studied the effects of acute alcohol intoxication on the plasma levels of allopregnanolone in male adolescents.

METHODS

Blood samples were drawn from male adolescents who arrived at the Emergency Department of the Hospital. Two groups were studied: one study group was formed by adolescents who arrived with evident behavioral symptoms of acute alcohol intoxication (AAI) and the other by those arriving for mild trauma (contusions, sprains) after no consumption of alcohol (Controls).

RESULTS

Our results demonstrate that AAI significantly increases serum allopregnanolone levels in male adolescents.

CONCLUSIONS

Because alcohol and allopregnanolone positively modulate gamma-aminobutyric acid type A (GABAA) receptors, allopregnanolone may play a major role in the anxiolytic and rewarding effects of alcohol, either directly or by influencing the sensitivity of GABAA receptors to alcohol.

[Involvement of the immunological system in the pathogenesis of transmissible spongiform encephalopathies]

OBJECTIVE

We review the current knowledge relative to the role of different immune system components and their contribution the spread of prions throughout the infected organism.

DEVELOPMENT

During the last years research made on transmissible spongiform encephalopathies conducted to the assumption that changes in the structure of a determined protein (prion protein, PrP) may become self-propagative. The generally assumed finding of an abnormally folded protein as the causative agent, able to propagate in hosts different from it was originated, is changing our views of transmissible diseases. The concept of infection resulting from pathogen propagation within a susceptible host has been steadily linked to the ability of nucleic acids to replicate their own coded information. In the prionosis, term comprising all known prion disorders, the information seems to be coded within the own protein conformation. This phenomena, once again, challenges the well-established principles of molecular biology.

CONCLUSIONS

Propagation of prions uses strategies not previously recognized, and depends upon prion conformation and/or specific host restrictions. Thus, certain sheep and goat prion strains (scrapie) or human (variant of Creutzfeldt-Jakob disease) invade the brain after an initial interaction with the immune system of affected individuals. The involvement of the lymphoreticular system or, at least, certain host's immune competence seems to be a prerequisite for neuro-invasion after a natural infection or peripheral inoculation. On the other hand, proper identification of immune cell types involved may open the possibility for post exposure prophylaxis.

Differential regulation of steroid 5alpha-reductase isozymes expression by androgens in the adult rat brain

The enzyme 5alpha-reductase (5alpha-R) is present in many mammalian tissues, including the brain. The physiological importance of 5alpha-R in the brain derives from its capability to convert testosterone (T) to a more potent androgen, dihydrotestosterone (DHT), and to convert progesterone and deoxycorticosterone (DOC) to their respective 5alpha-reduced derivatives, precursors of allopregnanolone and tetrahydroDOC, potent allosteric modulators of the gamma-aminobutyric acid receptor (GABA(A)-R). 5alpha-R occurs as two isoforms, 5alpha-R type 1 (5alpha-R1) and 5alpha-R type 2 (5alpha-R2). We studied the effects of T and DHT on the mRNA levels of both 5alpha-R isozymes in the prefrontal cortex of the adult rat, using an accurate and precise method that combines the high specificity of one-step quantitative RT-PCR with the sensitivity of capillary electrophoresis. Our results demonstrate that both isozymes of 5alpha-R are expressed in the cerebral cortex of adult rats. The gene expression of 5alpha-R type 2 is under the positive control of T and DHT. The gene that codes for 5alpha-R type 1 is not constitutive, because its expression is negatively regulated by T and DHT. These results open up a new research line that may lead to a better understanding of the role of 5alpha-R isozymes in the physiology of the central nervous system.

DHEA, PREG and their sulphate derivatives on plasma and brain after CRH and ACTH administration

The term neurosteroids applies to steroids that are synthesized in the nervous system, either de novo from cholesterol or from steroid hormone precursors. RIA was used to determine plasma and brain levels of the neurosteroids pregnenolone (PREG), dehydroepiandrosterone (DHEA), and their sulfate derivatives (PREG-S and DHEA-S) in male and female rats after administration of two typical stress hormones: corticotropin-releasing hormone (CRH) and adrenocorticotropin hormone (ACTH). In all cases, the parameters measured were detectable in plasma and brain. PREG, PREG-S, and DHEA increased significantly in plasma and brain after CRH and ACTH administration in males and females. Because neurosteroids play an important role in mammalian physiology, including that of humans, stress situations may alter the physiological functions regulated by these neurosteroids.

Alcohol intoxication increases allopregnanolone levels in female adolescent humans

Teenage drinking is a cause of growing concern in industrialized countries, where almost 35% of alcohol drinkers are under 16 years old. Increased anxiety, irritability, and depression among adolescents may induce them to seek the anxiolytic and rewarding properties of alcohol. We studied the effects of acute alcohol intoxication (AAI) on the plasma levels of progesterone and allopregnanolone in female adolescents. Blood samples were drawn from female adolescents who arrived at the emergency department. One study group was formed by those who arrived with evident behavioral symptoms of AAI and the other by those arriving for mild trauma (contusions, sprains) after no consumption of alcohol (controls). Our results demonstrate that AAI significantly increases serum progesterone and allopregnanolone levels in both follicular and luteal phases of the ovarian cycle. Since alcohol and allopregnanolone positively modulate gamma-aminobutyric acid type A (GABA(A)) receptors, allopregnanolone may play a major role in the anxiolytic and rewarding effects of alcohol, either directly or by influencing the sensitivity of GABA(A)-receptors to alcohol.

Early detection of PrPres in BSE-infected bovine PrP transgenic mice

Transgenic mouse lines expressing different levels of the bovine prion protein gene (boPrP(C)) were generated. Upon infection with BSE prions, all transgenic lines tested exhibited characteristics of the bovine disease. Typical CNS spongiform degeneration was observed by histopathology and presence of PrP(res) could be detected both by Western blot and immunohistochemistry (IHC) assays, confirming for this model the absence of an interspecies barrier to BSE infection. Differences in incubation times post-inoculation depend upon the expression level of boPrP(C) and the amount of prions in the inoculum. In the absence of clinical signs, pathognomonic markers of disease could be detected as early as 150 or 196 days post-inoculation by IHC and Western blot analysis, respectively. This result indicates that prion infectivity in experimental mouse bioassays can be measured earlier by assessing immunologically the presence of PrP(res) in brains from inoculated animals. Although these transgenic mice were also susceptible to sheep scrapie prion infection, the extent of incubation times was considerably longer and PrP(res) was detected in only 70 % of inoculated mice. Interestingly, transgenic mice-propagated sheep scrapie prions displayed distinct biochemical properties when compared to both the original sheep scrapie and transgenic mouse-propagated BSE inoculum.

The Antimicrobial Properties of Different Strains of Lactobacillus spp. Isolated from Kefir

The characteristics of 58 strains of Lactobacillus spp. isolated from kefir were studied. These strains were tested for adherence to human enterocyte-like Caco-2 cells, resistance to acidic pH and bile acid, antimicrobial activities against enteropathogenic bacteria and inhibition of Salmonella typhimurium attachment to Caco-2 cells. The best probiotic properties were observed in L. acidophilus CYC 10051 and L. kefiranofaciens CYC 10058. L. kefiranofaciens CYC 10058 produced an exopolysaccharide, which revealed that it was closely related to kefiran, a polysaccharide with antitumoral properties. This is the first in vitro study about the antimicrobial characteristics of the Lactobacillus population of kefir.

Magnetic relaxation of interacting co clusters: crossover from two- to three-dimensional lattices

The influence that dipole-dipole interactions exert on the dynamics of the magnetization of nanometer-sized Co clusters has been studied by means of ac and dc susceptibility experiments. These clusters grow in a quasiordered layered structure, where all relevant parameters can be tailored and measured independently. Our data show without ambiguity that the magnetic relaxation becomes slower as the degree of interaction increases. The effective activation energy increases linearly with the number of nearest neighbor clusters, evolving from the value for a 2D layer to the fully 3D behavior, which is nearly reached for five layers. The experimental results agree quantitatively with the predictions of a simple model.

ALS and PDC of Guam: forty-year follow-up

BACKGROUND

It was noticed in the mid-1950s that the incidence of ALS and parkinsonism--dementia complex (PDC) were much higher on Guam than anywhere else in the world. In 1958, a registry of patients and controls was established to ascertain the familial and genetic aspects of these diseases. Patients and individually matched controls and their relatives were registered from 1958 to 1963. The registry was updated and analyzed in 1998 through 1999.

OBJECTIVE

To ascertain whether first-degree relatives of patients had a higher risk for developing ALS or PDC than relatives of controls.

METHODS

During the period of 1958 to 1963, 126 new patients and 126 individually matched controls and their respective first-degree relatives and spouses were evaluated neurologically and registered. Forty years later, the number of new cases among the patient and control relatives were compared to an expected number of new cases based on the age- and sex-specific incidence of ALS and PDC in the population at large.

RESULTS

From 1958 to 1999, there were 102 new ALS or PDC cases among relatives of patients and 33 among relatives of controls. These values were compared with the derived expected values. There were more observed than expected new cases among patients' relatives, and less observed cases than expected among the controls' relatives.

CONCLUSIONS

Relatives of patients with ALS or PDC have significantly higher risks for developing the disease than the Guamanian population, whereas relatives of controls have significantly lower risks.

Effects of acute alcohol intoxication on pituitary-gonadal axis hormones, pituitary-adrenal axis hormones, beta-endorphin and prolactin in human adults of both sexes

- The effects of acute alcohol intoxication (AAI) on the pituitary-gonadal axis hormones, and the possible contribution of pituitary-adrenal axis hormones, beta-endorphin and prolactin to alcohol-induced dysfunction of pituitary-gonadal axis hormones were studied in adult men and women. Blood samples were drawn from adults of both sexes who arrived at the emergency department with evident behavioural symptoms of drunkenness (AAI) or from adult volunteers with nil consumption of alcohol (controls). Our results demonstrated that AAI produces a high increase in plasma prolactin, corticotropin (adrenocorticotropic hormone, ACTH), and cortisol in adults of both sexes, a decrease in luteinizing hormone levels only in men, an increase in dehydroepiandrosterone-sulphate (DHEAS) and a contradictory behaviour of testosterone according to gender, with increased plasma testosterone in women and a decrease in men. ACTH and prolactin correlated positively with cortisol, DHEAS and testosterone in women, which suggests that prolactin and ACTH could contribute to stimulated adrenal androgen production. In contrast, the decrease in testosterone and increase in beta-endorphin in men suggests that AAI could have an inhibitory effect on testicular testosterone, perhaps mediated by beta-endorphin. Our results suggest that the effect of alcohol on pituitary-gonadal axis hormones in humans could depend on the gender and degree of sexual maturity of the individual.

A rapid method for 90Sr determination in the presence of 137Cs in environmental samples

A rapid method for the determination of 90Sr in the presence of 137Cs using the Cherenkov radiation technique is described. The contribution of 137Cs to gross Cherenkov radiation (90Y + 137Cs) was examined for 137Cs /90Sr ratios ranging from 0.09 to 2.50 for 137Cs activities ranging from 2 to 1,211 Bq. Results from direct Cherenkov radiation measurement and results after radiochemical separation of 90Y from 90Sr for samples containing both 90Sr and 137Cs were compared. Errors below 5% were obtained for 137Cs /90Sr ratios lower than 1, when no separation was performed, independently of the activity level. However, errors between 10% and 35% were obtained for 137Cs/90Sr ratios higher than 1. In order to determine 90Sr activity in the presence of 137Cs using the Cherenkov technique, a multiple linear regression analysis model was established to correct the data for 137Cs content. The mathematical correction proposed was validated using 66 artificially contaminated lettuce samples in a laboratory experiment by taking into account the activity levels of 137Cs and 90Sr and the radionuclide ratios. Comparison of mathematically corrected radionuclide ratios with the results obtained without correction shows that, for radionuclide ratios higher than 1, error values for measuring 90Sr activity using the mathematical model were much smaller than when no radiochemical separation was performed. On the other hand, for ratios lower than 1, error values when measuring 90Sr activity with radiochemical separation were smaller than when mathematical correction was performed. In spite of this, the mathematical correction is an appropriate way of reducing the time needed to determine radiostrontium using the Cherenkov radiation technique. The method proposed could be a powerful tool for environmental research whenever the contents of 90Sr and 137Cs have to be determined.

The importance of genetic services for the theory of health: a basis for an integrating view of health

The first part of this article shows that our effective means to know and modify directly the human genetic make-up generates singular and difficult situations for the application of fundamental medical categories. Specifically, we demonstrate that in dealing with these situations, some predominant views on health, such as descriptivism or that which reduces the state of health to not having present disabilities, cannot provide adequate answers either from the point of view of medical science or in terms of our ordinary intuitions. The second part of the article examines the reasons for the failure of these views to tackle the mentioned situations, proposes solutions to urgent problems and, finally, offers some foundations for an alternative theoretical development, id est, for a theory of health able to satisfactorily integrate our genetic dimension.

First field trial of a transmissible recombinant vaccine against myxomatosis and rabbit hemorrhagic disease

As a novel approach for immunisation of wild rabbits, we have recently developed a transmissible vaccine against myxomatosis and rabbit hemorrhagic disease (RHD) based on a recombinant myxoma virus (MV) expressing the RHDV capsid protein [J. Virol. 74 (2000) 1114]. The efficacy and safety of the vaccine have been extensively evaluated under laboratory conditions. In this study, we report the first limited field trial of the candidate vaccine that was undertaken in an island of 34 Has containing a population of around 300 rabbits. Following administration by the subcutaneous route to 76 rabbits, the vaccine induced specific antibody responses against both myxomatosis and RHDV in all the inoculated rabbits. Furthermore, the recombinant virus exhibited a limited horizontal transmission capacity, promoting seroconversion of around 50% of the uninoculated rabbit population. No evidence of undesirable effects due to the recombinant virus field release was detected.

High prevalence of low HDL cholesterol concentrations and mixed hyperlipidemia in a Mexican nationwide survey

The prevalence of lipid abnormalities revealed in a survey done in 417 Mexican cities is described. Information was obtained on 15,607 subjects, aged 20 to 69 years. In this report, only samples obtained after a 9- to 12-h fast were included (2,256 cases: 953 men and 1,303 women). The population is representative of Mexican urban adults. Mean lipid concentrations were: cholesterol, 4.80 mmol/l; triglycerides, 2.39 mmol/l; HDL cholesterol, 1.00 mmol/l; and LDL cholesterol, 3.06 mmol/l. The most prevalent abnormality was HDL cholesterol below 0.9 mmol/l (46.2% for men and 28.7% for women). Hypertriglyceridemia (>2.26 mmol/l) was the second most prevalent abnormality (24.3%). Severe hypertriglyceridemia (>11.2 mmol/l) was observed in 0.42% of the population. Increased LDL cholesterol (> or =4.21 mmol/l) was observed in 11.2% of the sample. Half of the hypertriglyceridemic subjects had a mixed dyslipidemia or low HDL cholesterol. More than 50% of the low HDL cholesterol cases were not related to hypertriglyceridemia. Insulin resistance was found in 59% of them. In conclusion, the prevalence of hypoalphalipoproteinemia and other forms of dyslipidemia in Mexican adults is very high and it is among the highest previously reported worldwide.

Effects of CRH and ACTH administration on plasma and brain neurosteroid levels

The 3alpha-hydroxy ring A-reduced metabolite of progesterone, 3alpha-hydroxy-5alpha-pregnan-20-one (allopregnanolone) is among the most potent known ligands of the gamma aminobutyric acid (GABA) receptor, designated GABA-A, in the central nervous system. We determined by RIA serum levels of progesterone (PROG), 5-alpha-dihidroprogesterone (DHP) and allopregnanolone in male and female rats after corticotropin releasing hormone (CRH) and adrenocorticotropin hormone (ACTH) administration. Allopregnanolone was undetectable in plasma and brain of control males but detectable in plasma and brain of males injected with CRH and ACTH and of control and similarly treated females. Allopregnanolone increased in the plasma and brain after CRH and ACTH administration in all cases. The data demonstrate that the administration of CRH plus ACTH results in a rapid increase of the neuroactive steroid allopregnanolone in the brain of males and females to levels known to modulate GABA-A receptor function. Thus, stress could regulate neurosteroid biosynthesis via the hormones ACTH and CRH.

Crystalline dihydrotestosterone implants in the lateral septum of male rats. A positive effect on LH and FSH

Previous investigations in our laboratory have shown that testosterone implanted into the lateral septum in male rats increases LH and FSH secretion. However, it was unclear whether the effect of testosterone was direct via androgen receptor, or indirect via the estrogen receptor after conversion by aromatization to estradiol. To answer this question, we implanted either testosterone or the non-aromatizable androgen 5 alpha-dihydrotestosterone (DHT), into the lateral septum of adult male rats and measured plasma levels of LH and FSH by radioimmunoassay 2 days after implantation. Both testosterone and DHT significantly increased the plasma LH and FSH concentrations. Mean concentration of LH in control animals was 0.21 +/- 0.06 ng/ml, a figure that increased to 0.7 +/- 0.12 and 0.55 +/- 0.1 ng/ml after DHT or testosterone implantation respectively. Mean concentration of FSH in control animals was 1.5 +/- 0.3 ng/ml; this figure increased to 3 +/- 0.3 and 2.9 +/- 0.3 ng/ml after DHT or testosterone implantation. Neither plasma DHT (64.0 +/- 5.6 vs. 52 +/- 5 ng/100ml) nor plasma testosterone levels (4.1 +/- 0.38 vs. 3.3 +/- 0.18 ng/ml) were significantly affected by the implants. We conclude that androgens independently of conversion to estrogen acting in the lateral septum facilitates the release of LH and FSH.

Evidence of different actions of testosterone, estradiol, FSH, and LH on the growth axis

To study the possible role of sexual hormones, Testosterone (T), Estradiol (E2), follicle-stimulating hormone (FSH), and luteinizing hormone (LH) on the growth axis, we examined the correlations between the sex, growth hormone (GH), insulin-like growth factor-1 (IGF-1), insulin-like growth factor binding protein 3 (IGFBP3), FSH, LH, T and E2, in growth retarded children ranging in age from 7 to 13 yr. All hormones were measured by Radioimmunoassay (RIA) in a pool of aliquots of samples obtained every 20 min over 12 h (overnight) in each child. Multivariate statistical analysis was performed. We have found: a) Thai only FSH concentrations were significantly higher in girls than in boys; b) A positive correlation between T-IGF-1; T-IGFBP3; FSH-LH; FSH-IGF-1; FSH-IGFBP3, LH-IGF-1, LH-IGFBP3 the sex-FSH; and the sex-IGFBP3 c) A high positive correlation between plasmatic E2 and IGF-1/IGFBP3 ratio (an index of free, active IGF-1). We concluded that the sex, FSH, LH, T and E2 influence the growth axis. The sex through IGFBP3; LH, FSH, and T through IGF1 and IGFBP3; E2 through the IGF-1/IGFBP3 ratio, an index of active IGF-1.

Effects of acute alcohol intoxication on growth axis in human adolescents of both sexes

We previously reported the deleterious effects of acute alcohol intoxication (AAI) on pituitary-gonadal and pituitary-adrenal axes hormones in human adolescents. In the present paper we studied the effects of AAI on the growth axis hormones, and the possible contribution of the insulin-glucose axis to the alcohol-induced dysfunction of the growth axis in human adolescents. Blood samples were drawn from adolescents that arrived at the emergency department with evident behavioural symptoms of drunkenness (AAI) or with nil consumption of alcohol (controls [C]). AAI produced in the adolescents of both sexes in our series: a decrease in growth hormone (GH) levels, without significant alteration of either insulin-like growth factor-I (IGF-I) or insulin-like growth factor binding protein-3 (IGFBP3); an increase in plasma glucose and a decrease in insulin in the female adolescents but not in the males. Males and females undergo a significant period of bone growth during adolescence. Growth axis hormones play an important role in the pubertal spurt. Thus, ethanol consumption during adolescence could have long-lasting deleterious effects on this aspect of development. In industrialised countries, around 35% of alcohol drinkers are under 16 years old, therefore the result of this study should be made known to adolescents and the appropriate authorities.

Safety evaluation of a recombinant myxoma-RHDV virus inducing horizontal transmissible protection against myxomatosis and rabbit haemorrhagic disease

We have recently developed a transmissible vaccine to immunize rabbits against myxomatosis and rabbit haemorrhagic disease based on a recombinant myxoma virus (MV) expressing the rabbit haemorrhagic disease virus (RHDV) capsid protein [Bárcena et al. Horizontal transmissible protection against myxomatosis and rabbit haemorragic disease using a recombinant myxoma virus. J. Virol. 2000;74:1114-23]. Administration of the recombinant virus protects rabbits against lethal RHDV and MV challenges. Furthermore, the recombinant virus is capable of horizontal spreading promoting protection of contact animals, thus providing the opportunity to immunize wild rabbit populations. However, potential risks must be extensively evaluated before considering its field use. In this study several safety issues concerning the proposed vaccine have been evaluated under laboratory conditions. Results indicated that vaccine administration is safe even at a 100-fold overdose. No undesirable effects were detected upon administration to immunosuppressed or pregnant rabbits. The recombinant virus maintained its attenuated phenotype after 10 passages in vivo.

Effects of acute alcohol intoxication on pituitary-gonadal axis hormones, pituitary-adrenal axis hormones, beta-endorphin and prolactin in human adolescents of both sexes

Teenage drinking continues to be a major problem in industrialized countries, where almost 35% of alcohol drinkers are under 16 years old. In the present paper we studied the effects of acute alcohol intoxication (AAI) on the pituitary-gonadal (PG) axis hormones, and the possible contribution of pituitary-adrenal (PA) axis hormones, beta-endorphin (BEND), and prolactin (PRL) to the alcohol-induced dysfunction of PG axis hormones. Blood samples were drawn from adolescents that arrived at the emergency department with evident behavioral symptoms of drunkenness (AAI) or with nil consumption of alcohol (controls [C]). Our results demonstrated that AAI produces in adolescents a high increase in plasma PRL, ACTH, and cortisol (F), and a contradictory behavior of testosterone (T) according to gender: plasma T was increased in females and decreased in males. ACTH and PRL correlated positively with F, dehydroepiandrosterone-sulphate (DHEAS) and T in females, which suggests that PRL and ACTH could synergistically stimulate adrenal androgen production. In contrast, the decrease in T and increase in BEND in males suggests that AAI could have an inhibitory effect on testicular T, perhaps mediated by BEND. The hormones studied are involved in the development of secondary sexual characteristics and the growth axis during adolescence. The deleterious effects of alcohol abuse should be made known to adolescents and the appropriate authorities.