The FLARE score, circulating neutrophils, and association with COVID-19 outcomes in patients with solid tumors

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Background: Inflammation and neutrophils play a central role in severe Covid-19 disease. In previous data, we showed that the FLARE score, combining both tumor and Covid-19-induced proinflammatory status (proinflam-status), predicts early mortality in cancer patients (pts) with Covid-19 infection. We aimed to assess the impact of this score in a larger cohort and characterize the immunophenotype (IF) of circulating neutrophils. Methods: Multicenter retrospective cohort (RC) of pts with cancer and Covid-19 infection across 14 international centers. Circulating inflammatory markers were collected at two timepoints: baseline (-15 to -45d before Covid-19 diagnosis) and Covid-19 diagnosis. Tumor-induced proinflam-status was defined by high dNLR (neutrophils/(leucocytes-neutrophils)>3) at baseline. Covid-19-induced proinflam-status was defined by +100% increase of dNLR between both timepoints. We built the FLARE score combining both Tumor and Infection-induced inflammation: T+/I+ (poor), if both proinflam-status; T+/I- (T-only), if inflammation only due to tumor; T-/I+ (I-only), if inflammation only due to Covid; T-/I- (favorable), if no proinflam-status. The IF of circulating neutrophils by flow cytometry was determined in a unicenter prospective cohort (PC) of pts with cancer during Covid-19 infection and in healthy volunteers (HV). Primary endpoint was 30-day mortality. Results: 524 pts were enrolled in the RC with a median follow-up of 84d (95%CI 78-90). Median age was 69 (range 35-98), 52% were male and 78% had baseline PS <1.Thoracic cancers were the most common (26%). 70% had active disease, 51% advanced stage and 57% were under systemic therapy. dNLR was high in 25% at baseline vs 55% at Covid-19 diagnosis. The median dNLR increase between both timepoints was +70% (IQR: 0-349%); 42% had +100% increase of dNLR. Pts distribution and mortality across FLARE groups is resumed in the Table. Overall mortality rate was 26%. In multivariate analysis, including gender, stage and PS, the FLARE poor group was independently associated with 30-day mortality [OR 5.27; 1.37-20.3]. 44 pts were enrolled in the PC. Median circulating neutrophils were higher in pts with cancer (n=10, 56.7% [IQR: 39-78.4%]) vs HV (n=6, 35.8% [IQR: 25.6-21%]), and particularly higher in pts with cancer and severe Covid-19 infection (n=7, 88.6% [IQR: 80.9-94%] (p=0.003). A more comprehensive characterization of the IF of circulating neutrophils, including Lox1/CD62/CD64, will be presented at ASCO. Conclusions: The FLARE score, combining tumor and Covid-19-induced proinflam-status, can identify the population at higher risk for mortality. A better characterization of circulating neutrophils may help improve the prediction of Covid-19 outcomes in pts with cancer. [Table: see text]

Effectiveness of immunosuppression minimisation, conversion or withdrawal strategies in paediatric solid organ and haematopoietic stem cell transplantation: a protocol of a systematic review and meta-analysis

INTRODUCTION

Paediatric transplantation is the only curative therapeutic procedure for several end-stage rare diseases affecting different organs and body systems, causing altogether great impact in European children's health and quality of life. Transplanted children shift their primary disease to a chronic condition of immunosuppression to avoid rejection. Longer life expectancy in children poses a greater risk of prolonged and severe side effects related to long-term immunosuppressive (IS) disabilities and secondary cancer susceptibility. The goal remains to find the best combination of IS agents that optimises allograft survival by preventing acute rejection while limiting drug toxicities. This systematic review will aim to determine the optimal IS strategy within the so-called minimisation, conversion or withdrawal strategies.

METHODS AND ANALYSIS

We will search the following databases with no language restrictions: Cochrane Central Register of Controlled Trials in the Cochrane Library, OvidSP Medline and Epub Ahead of Print, In-Process & Other Non-Indexed Citations and Daily; OvidSP Embase Classic+Embase; Ebsco CINAHL Plus, complete database; WHO International Clinical Trials Registry Platform search portal. We will include controlled and uncontrolled clinical trials along with any prospective or retrospective study that includes a universal cohort (all participants from a centre/region/city over a certain period). Cases series and cross-sectional studies are excluded. Two review authors will independently assess the trial eligibility, risk of bias and extract appropriate data points. The outcomes included in this review are: patient survival, acute graft rejection, chronic graft rejection, diabetes, graft function, graft loss, chronic graft versus host disease, acute graft versus host disease, surgical complications, infusion complications, post-transplant lymphoproliferative disease, liver function, renal function, cognition, depression, health-related quality of life, hospitalisation, high blood pressure, low blood pressure, cancer-other, cancer-skin, cardiovascular disease, bacterial infection, Epstein-Barr infection, cytomegalovirus infection, other viral infections and growth.

Tuberculosis peritoneal y pleural en un paciente inmunocompetente con dolor abdominal crónico

La tuberculosis es un grave problema de salud pública más acentuado en los países en desarrollo. De las manifestaciones extrapulmonares las que comprometen la cavidad abdominal están dentro de las menos frecuentes y se asocian con factores de predisposición específica. Se requiere un alto nivel de sospecha diagnóstica en el abordaje inicial de esta enfermedad. Presentamos el caso de un adulto masculino sin condiciones de predisposición quien consultó por un cuadro de dolor abdominal crónico y los estudios complementarios manifestaron una tuberculosis peritoneal con compromiso pleural sin síntomas respiratorios.

Presumptive BSE cases with an aberrant prion protein phenotype in Switzerland, 2011: Lack of prion disease in experimentally inoculated cattle and bovine prion protein transgenic mice

Bovine spongiform encephalopathy (BSE) is caused by different prion strains that are discriminated by the molecular characteristics of the pathological prion protein. In 2011, Switzerland reported two presumptive cases of BSE in cattle with a prion protein phenotype different from previously described strains, and it was unclear whether these findings were related to a transmissible disease and have implications on animal and public health. In this study, brain tissues of these cases were inoculated into transgenic mice expressing the bovine prion protein (BoPrP-Tg110) and into cattle. Clinical and pathological investigations as well as molecular testing did not provide evidence for the presence of BSE in the Swiss cases after two passages in BoPrP-Tg110 mice and a challenge period of 3.5 years in cattle. This lack of disease transmission suggests that the Swiss 2011 cases were not affected by a prion disease and were unrelated to the feed-born BSE epidemic.

Detection of Leishmania spp. in Bats from an Area of Brazil Endemic for Visceral Leishmaniasis

The multihost parasites Leishmania spp. infect a broad range of wild mammalian species including bats. Several species of bats have adapted to a variety of food resources and shelters in urban areas. This study aimed to detect Leishmania spp. DNA in bats present in forest fragments located in metropolitan areas endemic for leishmaniasis in Campo Grande, Mato Grosso do Sul (MS), Brazil. Blood samples were obtained from 80 individuals, including eight species of Phyllostomidae and one species of Vespertilionidae. Thirty of the 80 bats were positive for Leishmania spp. using conventional PCR, all belonging to the family Phyllostomidae. Eighteen samples tested by real-time PCR (qPCR) using specific primers for the kDNA of Leishmania infantum were positive. To the best of our knowledge, this is the first report detecting Leishmania spp. in Platyrrhinus incarum in addition to being the first reported detection of L. infantum in the bat species Phyllostomus discolor, Platyrrhinus lineatus, Artibeus planirostris and Artibeus lituratus. Our results show that bats can host Leishmania spp. in areas endemic for leishmaniasis, which must be taken into account in disease control operations by public health authorities.

Lack of Association Between Elevated Urinary Levels of Interleukin-10 and Interferon Gamma With the Presence of Inflammation in Kidney Transplant Recipients

INTRODUCTION

A lot of evidence has demonstrated the importance of different cytokines in acute renal rejection. Previous studies have examined the presence or absence of interleukin (IL)-10 in related immunopathologic rejection grafts as well as other interleukins. Studies in human transplantation show elevated levels of IL-10 and gamma interferon (INF-γ) in inflammation and rejection.

OBJECTIVE

The objective of this study was to demonstrate the lack of association of elevated urinary levels of IL-10 and IFN in the presence of active inflammation.

METHODS

An observational, descriptive, cross-sectional study conducted in transplant recipients at 12 months of follow-up after renal transplantation. In those who were held biopsy after renal transplantation at one year follow-up, or allograft dysfunction, we also measured IL-10 and INF-γ in the urine. The following were considered as variables: age, body mass index (BMI), gender, transplant type, creatinine, chronic kidney disease epidemiology collaboration equation, (CKD-EPI), modification of diet in renal disease study equation (MDRD), Banff classification, and levels of IL-10 and INF-γ. Statistical analysis was performed calculating a sample size of 25 patients, with an alpha bias of 0.05%, yielding measures of central tendency and determining no association between levels of IL-10 and INF-γ with the presence of rejection using SPSS 21.0 program.

RESULTS

A total of 50 patients, 34 (68%) males, 16 (32%) females, with an average 31.7 ± 9.9 years, weight of 64.91 ± 13.84 kg, size 1.60 ± 0.10 m and 24.97 ± 4.07 BMI were included,39 (78%) living donor and 11 (22%) cadaveric. Twenty-six (52%) showed inflammation in the biopsy and 24 (48%) showed none. Mean creatinine was 1.81 ± 1.5, and the estimated glomerular filtration rate (eGFR) was 55.27 ± 22.46, 65.76 ± 26.7. (MDRD and CKD-EPI, respectively). No statistical difference was found in the levels of IL-10 and IFN-γ using analysis of variance. (ANOVA; P = .467 and P = .063, respectively) Based on Banff, the inflammation on biopsy score was 2.78 ± 2.84. There was statistical significance (P < .05) with respect to the Cr and eGFR by different equations. There were no significant interactions between cytokine levels and more than 1 factor. (as indicated by P < .2).

DISCUSSION AND CONCLUSIONS

No significant differences were observed in the level of interleukins in patients with and without inflammation, denoting an adequate immunosuppression in most of these patients. Determination of inflammatory cytokines in urine could be used as a determinant of a good immunosuppression status, rather than as an early marker of rejection.

Actin polymerisation after FCγR stimulation of human fibroblasts is BCL10 independent

B-cell lymphoma 10 (BCL10) is not essential for actin polymerisation after FcγR stimulation in human fibroblasts.

Dysfunction of the PI3K-Akt-GSK-3 pathway is a common feature in cell culture and in vivo models of prion disease

AIMS

Transmissible spongiform encephalopathies, also called prion diseases, are characterized by the cerebral accumulation of misfolded prion protein (PrP(SC) ) and subsequent neurodegeneration. However, despite considerable research effort, the molecular mechanisms underlying prion-induced neurodegeneration are poorly understood. Here, we explore the hypothesis that prions induce dysfunction of the PI3K/Akt/GSK-3 signalling pathway.

METHODS

We employed two parallel approaches. Using cell cultures derived from mouse primary neurones and from a human neuronal cell line, we identified common elements that were modified by the neurotoxic fragment of PrP(106-126) . These studies were then complemented by comparative analyses in a mouse model of prion infection.

RESULTS

The presence of a polymerized fragment of the prion protein (PrP(106-126) ) or of a prion strain altered PI3K-mediated signalling, as evidenced by Akt inhibition and GSK-3 activation. PI3K activation by the addition of insulin or the expression of a constitutively active Akt mutant restored normal levels of Akt and GSK-3 activity. These changes were correlated with a reduction in caspase activity and an increase in neuronal survival. Moreover, we found that activation of caspase 3, Erk and GSK-3 are common features of PrP(106-126) -mediated neurotoxicity in cellular systems and prion infection in the mouse cerebellum, while activation of caspase 12 and JNK was observed in cellular models.

CONCLUSIONS

Our findings in cell culture and in vivo models of prion disease demonstrate marked alterations to the PI3K/Akt/GSK-3 pathway and suggest that two additional pathways contribute to PrP-induced neurotoxicity as responsible of JNK and caspase 12 activation.

Inherited BCL10 deficiency impairs hematopoietic and nonhematopoietic immunity

Heterotrimers composed of B cell CLL/lymphoma 10 (BCL10), mucosa-associated lymphoid tissue lymphoma translocation protein 1 (MALT1), and caspase recruitment domain-containing (CARD) family adaptors play a role in NF-κB activation and have been shown to be involved in both the innate and the adaptive arms of immunity in murine models. Moreover, individuals with inherited defects of MALT1, CARD9, and CARD11 present with immunological and clinical phenotypes. Here, we characterized a case of autosomal-recessive, complete BCL10 deficiency in a child with a broad immunodeficiency, including defects of both hematopoietic and nonhematopoietic immunity. The patient died at 3 years of age and was homozygous for a loss-of-expression, loss-of-function BCL10 mutation. The effect of BCL10 deficiency was dependent on the signaling pathway, and, for some pathways, the cell type affected. Despite the noted similarities to BCL10 deficiency in mice, including a deficient adaptive immune response, human BCL10 deficiency in this patient resulted in a number of specific features within cell populations. Treatment of the patient's myeloid cells with a variety of pathogen-associated molecular pattern molecules (PAMPs) elicited a normal response; however, NF-κB-mediated fibroblast functions were dramatically impaired. The results of this study indicate that inherited BCL10 deficiency should be considered in patients with combined immunodeficiency with B cell, T cell, and fibroblast defects.

Mapping of neurotrophins and their receptors in the adult mouse brain and their role in the pathogenesis of a transgenic murine model of bovine spongiform encephalopathy

Neurotrophins are a family of growth factors that act on neuronal cells. The neurotrophins include nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF) and neurotrophin (NT)-3, -4 and -5. The action of neurotrophins depends on two transmembrane-receptor signalling systems: (1) the tropomyosin-related kinase (Trk) family of tyrosine kinase receptors (Trk A, Trk B and Trk C) and (2) the p75 neurotrophin receptor (p75(NTR)). The interaction between neurotrophic factors and their receptors may be involved in the mechanisms that regulate the differential susceptibility of neuronal populations in neurodegenerative diseases. The aim of the present study was to evaluate the role of neurotrophins in the pathogenesis of bovine spongiform encephalopathy (BSE) using a transgenic mouse overexpressing bovine prnp (BoTg 110). Histochemistry for Lycopersicum esculentum agglutinin, haematoxylin and eosin staining and immunohistochemistry for the abnormal isoform of the prion protein (PrP(d)), glial fibrillary acidic protein (GFAP), NGF, BDNF, NT-3 and the receptors Trk A, Trk B, Trk C and p75(NTR) was performed. The lesions and the immunolabelling patterns were assessed semiquantitatively in different areas of the brain. No significant differences in the immunolabelling of neurotrophins and their receptors were observed between BSE-inoculated and control animals, except for p75(NTR), which showed increased expression correlating with the distribution of lesions, PrP(d) deposition and gliosis in the BSE-inoculated mice.

Genome wide association studies for diabetes: perspective on results and challenges

Recent results of genome wide association study (GWAS) for diabetes genes, while reaching impressive technical milestones and implicating new findings for research, have been uniformly disappointing in terms of immediate clinical utility. The relative risk associated with any of the newly reported genetic loci, or even considering all of them together, is far less than simply that which can be obtained by taking a history and a physical exam. For type 2 diabetes (T2D), GWAS have implicated novel pathways, supported previously known associations, and highlighted the importance of the beta cell and insulin secretion. Monogenic forms of diabetes, on the other hand, continue to yield interesting insights into genes controlling human beta cell function but most cases of monogenic diabetes are simply not diagnosed. Here, we briefly review recent results related to type 1, type 2 and maturity onset diabetes of youth (MODY) diabetes and suggest that future studies emphasizing quantitative traits are likely to yield even more insights.

Steroid 5α-reductase in adult rat brain after neonatal dihydrotestosterone administration

Testosterone (T) is known to play an important masculinizing role in the developing brain of rat, including the regulation of 5α-reductase (5α-R) isozymes. However, the effects of dihydrotesterone (DHT), a more potent androgen than T, have not been elucidated. In this study, DHT was administered from day 5 through day 20 of postnatal life (period of postnatal sexual differentiation of the central nervous system) at doses of: 12 mg/kg/d on days 5, 6, 7, 8, 19, and 20; 15 mg/kg/d on days 9, 10, 11, 12, 16, 17, and 18; and 18 mg/kg/d on days 13, 14, and 15. In adulthood, quantitative RT-PCR was used to measure mRNA levels of 5α-R1 and 5α-R2 isozymes in the prefrontal cortex (PFC) of male and female rats with varied androgenic status. Under our study conditions, neonatal DHT administration influenced on adult PFC 5α-R isozymes levels and their regulation pattern by androgens, and this pattern was the inverse of that reported in adult neonatally T-treated rats.

Late stage cathepsin C, CXCL13 and Ki-67 overexpression correlate with regional neuropathology in a BSE transgenic murine model

A DNA microarray-based gene expression analysis study was performed with bovine spongiform encephalopathy (BSE) transgenic mice. Several genes were found to be overexpressed including the lysosomal enzyme cathepsin C, the chemokine CXCL13 and a number of genes related to cellular proliferation. The brains from terminal stage, BSE inoculated, 'bovinized', transgenic mice were subjected to immunohistochemistry with antibodies against these two proteins and Ki-67, a cell proliferation marker, to assess the biological relevance of the gene expression changes. Differential expression of cathepsin C and CXCL13 proteins and increased expression of Ki-67 was observed. These changes were localized to areas of deposition of PrP(res) and spongiform change and to areas showing an astroglial and microglial response. These findings suggest that these proteins are involved in the mechanisms leading to the establishment of transmissible spongiform encephalopathy.

Lipid profiles and oxidative stress parameters in male and female hemodialysis patients

To study atherogenesis markers in patients with stage 5D chronic kidney disease (CKD-5D) on hemodialysis to determine which parameters are modified and whether their behavior differ between male and female patients of similar age. Total cholesterol, triglycerides, glucose, total proteins, HDL-cholesterol, LDL-cholesterol, oxidative modification of low-density lipoprotein-cholesterol, autoantibodies against oxidized low-density lipoproteins-cholesterol, homocysteine (Hcy), folate, and vitamin B12 were measured in male and female controls and CKD-5D patients on hemodialysis for >6 months. The CKD-5D patients had significantly lower cholesterol, LDL-c and ox-LDL levels and significantly higher ox-LDL-AB and Hcy levels versus their respective controls. The reduction in ox-LDL in CKD patients does not imply a lower risk of atherosclerosis. In fact, the risk may be higher due to a greater capture of ox-LDL by macrophage scavenger receptors, which are increased in these patients. Elevated Hcy levels may also be a risk factor for atherosclerosis in male and female CKD-5D patients.

Elastic constants and dimensions of imprinted polymeric nanolines determined from Brillouin light scattering

Elastic constants and cross-sectional dimensions of imprinted nanolines of poly(methyl methacrylate) (PMMA) on silicon substrates are determined nondestructively from finite-element inversion analysis of dispersion curves of hypersonic acoustic modes of these nanolines measured with Brillouin light scattering. The results for the cross-sectional dimensions, under the simplifying assumption of vertical sides and a semicircular top, are found to be consistent with dimensions determined from critical-dimension small-angle x-ray scattering measurements. The elastic constants C(11) and C(44) are found to be, respectively, 11.6% and 3.1% lower than their corresponding values for bulk PMMA. This result is consistent with the dimensional dependence of the quasi-static Young's modulus determined from buckling measurements on PMMA films with lower molecular weights. This study provides the first evidence of size-dependent effects on hypersonic elastic properties of polymers.

Post-surgical enterococcal meningitis: Clinical and epidemiological study of 20 cases

Enterococcal post-surgical meningitis is an uncommon disease. 20 episodes of nosocomial post-surgical enterococcal meningitis diagnosed between 1994 and 2003 were retrospectively studied. During the period of study 20 cases of post-surgical enterococcal meningitis (60% female, mean age 55+/-18 y, range 16-78 y) were reviewed. The mean time between admission at the hospital and surgery was 26 (SD = 15) d (range 7-61 d). The most frequent underlying diseases were: intracerebral haemorrhage (55%), brain neoplasms (25%), head trauma (15%) and hydrocephalus (5%). 11 patients had previously received antibiotic treatment. The isolates identified were Enterococcus faecalis (n = 18) (90%), E. faecium (1) and E. durans (1). 11 patients had polymicrobial infections. The treatment most frequently used was vancomycin alone or with other antibiotics (11). In 5 patients intrathecal vancomycin (20 mg/d) was also added. The mortality rate was not different in intrathecally treated patients. Cerebrospinal fluid (CSF) devices were removed in 8 patients. Four patients died due to the infection. Mortality was significantly associated with lack of removal of the CSF devices (p = 0.04). Enterococcal spp. are a cause of nosocomial meningitis associated with neurosurgical procedures and the presence of neurological devices.

Detection and survival of prion agents in aquatic environments

Environmental contamination is considered a potential mechanism of transmission of prion diseases. Sheep scrapie and cervid chronic wasting diseases (CWD) epizootics are thought to be maintained by natural horizontal transmission through the environment. Here, we describe a method for the detection of prion proteins (PrPres) in aquatic environments. The procedure is based on a glycine buffer-mediated extraction, sonication, and an ultracentrifugation step. The detection limit of the method was estimated to be over 5-10 microg of infected tissue. In order to determine the inactivation of these agents, we spiked infected brain tissue in urban sewage, seawater and a buffered solution (final concentrations of 0.1-0.2% brain in matrix), and studied the decay of BSE- and scrapie-associated PrPres over time (up to 265 days). Densitometric data from Western blots were plotted in logarithmic scale against time. Reduction of PrPres titer in sewage was quantified in one logarithm after 13.5 days for BSE, 27.9 days for mouse-passaged scrapie and 32.6 days for sheep scrapie. In the buffered solution, a logarithm of BSE-associated PrPres also disappeared earlier than that of scrapie (113.9 and 214.3 days, respectively). By means of the covariance analysis, these differences in the inactivation patterns were shown to be statistically significant. According to the data, prions may be stable for extended periods of time in buffered solutions like PBS, but would show limited survival in aquatic environmental matrices.

Effects of swim stress on mRNA and protein levels of steroid 5α-reductase isozymes in prefrontal cortex of adult male rats

The metabolite of progesterone, allopregnanolone, is among the most potent known ligands of the gamma-aminobutyric acid receptor complex (GABA(A)-R) in the central nervous system. This neuroactive steroid is markedly increased in an animal model of acute stress. Allopregnanolone is synthesized from progesterone by steroidogenic enzymes 5alpha-reductase (5alpha-R) and 3alpha-hydroxysteroid dehydrogenase (3alpha-HSD), with the former being the rate-limiting enzyme in this reaction sequence. In this paper, a quantitative RT-PCR method coupled to laser-induced fluorescence capillary electrophoresis (LIF-CE) and Western blot were used to measure both mRNA and protein levels of 5alpha-R type 1 (5alpha-R1) and 5alpha-R type 2 (5alpha-R2) isozymes in prefrontal cortex of male rats after acute swim stress situations. Our results demonstrate that both 5alpha-R isozymes are significantly higher in prefrontal cortex of male rats after acute swim stress in comparison with control rats. These data may open up a new research line that could improve our understanding of the role of 5alpha-R isozymes in processes that accompany stress situations.

Discrimination of sheep susceptible and resistant to transmissible spongiform encephalopathies by an haplotype specific monoclonal antibody

In the present report, the selective detection of sheep PrP haplotypes by monoclonal antibody 2A11 is described. It is showed that the substitution of glutamine by arginine but not by histidine at ovine PrP position 171 abolishes completely the recognition of either PrP(c) or PrP(d) by mAb 2A11, in such a way that the application of this antibody allows the unambiguous discrimination of R(171) homozygotes. On the basis of the high resistance to classical scrapie and bovine spongiform encephalophaty (BSE) infection associated to the R(171) PrP haplotype, animals bearing the ARR allele are currently selected within the scrapie national plan initiated in Great Britain. A 2A11-based immuno enzymatic test have been developed and evaluated using a panel of plasma and sera from sheep of different PrP genotypes and breeds. The test allows the efficient discrimination of R(171) homozygotes, R(171) heterozygotes and non-R(171) carriers, therefore offering a rapid, cheap and easy to use alternative method to select sheep for their resistance to scrapie.

Histoplasmosis infection in Spanish travelers to Latin America

The aim of the study presented here was to assess the incidence of histoplasma infection in a cohort of 342 individuals in Spain who had traveled to Latin America for the first time. The histoplasmin skin test was positive in 20% of the travelers, and Central America posed a higher risk for infection than South America (p=0.013). Sleeping outdoors (p=0.031) and the duration of travel (p=0.016) were also identified as significant risk factors. Serological testing demonstrated poor overall sensitivity for detecting infection in the travelers, but for the symptomatic acute cases the results were improved. Histoplasmosis must be considered in patients presenting with fever (odds ratio=3.51 [1.52-8.12]) or cough (odds ratio=4.24 [1.32-13.58]) after visiting Latin America. The results of this study have public health implications and indicate the risks of acquiring histoplasmosis should be included in pre-travel counseling.

Effects of testosterone on brain mRNA levels of steroid 5alpha-reductase isozymes in early postnatal life of rat

The enzyme 5alpha-reductase (5alpha-R) (EC 1.3.99.5) exists as two isoforms, 5alpha-R type 1 (5alpha-R1) and 5alpha-R type 2 (5alpha-R2), and both are present in the brain. 5alpha-R1 has been proposed as a constitutive enzyme that essentially plays a catabolic and neuron protective role whereas 5alpha-R2 has been associated with sexually dimorphic functions of the male. In this work, we studied the effects of testosterone (T), the masculinizing hormone of the central nervous system (CNS), on mRNA levels of both 5alpha-R isoforms in the prefrontal cortex of male and female rats during the postnatal sexual differentiation of the CNS in the rat, using one-step quantitative RT-PCR coupled with laser-induced fluorescence capillary electrophoresis (LIF-CE). We found an increase in 5alpha-R2 mRNA levels in both male and female rats after T treatment, while 5alpha-R1 mRNA levels were decreased in the same experimental conditions. Our results clearly indicated that T regulates the expression of both 5alpha-R1 and 5alpha-R2 genes in an opposite manner and independently of the sex. This could point to a crucial role of T in the sexual dimorphism for both 5alpha-R isozymes in the neonatal brain. These results open up a new research line that could improve understanding of the role of 5alpha-R isozymes in the physiology of the CNS.

Steroid 5alpha-reductase isozymes in the adult female rat brain: central role of dihydrotestosterone

The enzyme 5alpha-reductase (5alpha-R) (EC 1.3.99.5) exists as two isoforms, 5alpha-R type 1 (5alpha-R1) and 5alpha-R type 2 (5alpha-R2). 5alpha-R1 has been associated with catabolic functions whereas 5alpha-R2 has been associated with sexually dimorphic functions of the male. We recently demonstrated that both 5alpha-R isozymes are present in the central nervous system (CNS) of the adult male rat and are regulated in an opposing way by androgens. This finding raises the question as to whether both isozymes play a role in the sexual dimorphism of the CNS, besides other functions. To test this hypothesis, it is essential to study the regulation of both isozymes by androgens in the female. In this work, we studied the effects of testosterone (T) and dihydrotestosterone (DHT) on mRNA levels of both 5alpha-R isoforms in the prefrontal cortex of the adult female rat by one-step quantitative RT-PCR coupled with laser-induced fluorescence capillary electrophoresis. Our results demonstrate for the first time that 5alpha-R2 mRNA is slightly regulated by T and DHT in females. Surprisingly, 5alpha-R1 mRNA is not regulated by T in the intact female, whereas it is very positively regulated by DHT, a more potent androgen than T. These data indicate the great sexual dimorphism in the CNS with respect to both 5alpha-R isozymes, and suggest a crucial role of DHT in the sexual dimorphism of the CNS in the female. These results open up a new research line that may lead to a better understanding of the physiology of the CNS.

Genetic tools, Kuhnean theoretical shift and the geneticization process

The growing use of genetic tests in medical practice has a strong influence on some widespread notions of health and unhealth. Two consequences of this phenomenon are: (i) important changes in the meaning of these current notions and, therefore, (ii) the arrival of a new taxonomy or rearrangement for the so-called "health-concepts". This paper attempts to demonstrate that both facts fuel a theoretical change that might be considered a model of scientific Kuhnean change in a fundamental aspect. On the other hand, this theoretical shift process offers the basis for approaching a present-day controversy, i.e. whether Western society is going through a period of geneticization or not, from a new perspective.

Transgenic mice expressing bovine PrP with a four extra repeat octapeptide insert mutation show a spontaneous, non-transmissible, neurodegenerative disease and an expedited course of BSE infection

Transgenic (Tg) mice carrying four extra octapeptide repeats (OR) in the bovine PrP gene (10OR instead of 6) have been generated. In these mice, neuropathological changes were observed depending upon the level of transgene expression. These changes primarily involved a slowly advancing neurological disorder, characterized clinically by ataxia, and neuropathologically, by vacuolization in different brain areas, gliosis, and loss of cerebellar granule cells. Accumulation of insoluble bovine 10OR-PrP (bo10OR-PrP) was observed depending on the level of expression but no infectivity was found associated with this insoluble form. We also compared the behavior of bo6OR-PrP and bo10OR-PrP Tg mouse lines in response to BSE infection. BSE-inoculated bo10ORTg mice showed an altered course of BSE infection, reflected by reduced incubation times when compared to bo6ORTg mice expressing similar levels of the wild type 6OR-PrP. In BSE-inoculated mice, it was possible to detect PrP(res) in 100% of the animals. While insoluble bo10OR-PrP from non-inoculated bo10ORTg mice was non-infectious, brain homogenates from BSE-inoculated bo10ORTg mice were highly infectious in all the Tg mouse lines tested. This Tg mouse model constitutes a new way of understanding the pathobiology of bovine transmissible spongiform encephalopathy. Its potential applications include the assessment of new therapies against prion diseases.

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.