Gender ratio trends over time in multiple sclerosis patients from Argentina

Several studies in multiple sclerosis (MS) suggest a trend of increasing disease frequency in women during the last decades. A direct comparison of gender ratio trends among MS populations from Argentina remains to be carried out. The objective of the study was to compare gender ratio trends, over a 50-year span in MS populations from Argentina.

METHODS

multicenter study that included patients from 14 MS Centers of Argentina. Patients with definite MS with birth years ranging from 1940 to 1989 were included. Gender ratios were calculated by five decades based on year of birth and were adjusted for the F/M born-alive ratio derived from the Argentinean national registry of births. The F/M ratios were calculated using a multivariate logistic regression per five decades by the year of birth approach. Analyses were performed using Stata 10.1.

RESULTS

1069 patients were included. Gender ratios showed a significant increase from the first to the last decade in the whole MS sample (from 1.8 to 2.7; p value for trend=0.023). The Gender ratio did not show differences considering MS subtype.

CONCLUSION

our study showed a modest increase of the F/M ratio (from 1.8 to 2.7) over time among patients affected by MS in Argentina.

Seasonal composition, abundance and biomass of the subestuarine fish assemblage in Solís Chico (Río de la Plata estuary, Uruguay)

Abstract The large estuaries can present long narrow branches called subestuaries or tidal creeks. These types of subsystems are distributed along the Uruguayan coast of the Río de la Plata estuary and are very important as nursery and refuge areas for fish. For the first time, the seasonal composition and abundance of the fish community of the Solís Chico subestuary was studied by using beach and gill nets. Fourteen species, mainly euryhaline (86%) presented a significant representation of juvenile stages. The fish community was dominated by Odontesthes argentinensis, Platanichthys platana, Mugil liza, Brevoortia aurea, Micropogonias furnieri and Paralichthys orbignyanus, similar to adjacent subestuaries. While Micropogonias furnieri and B. aurea were the most abundant species, some other species were rarely caught. A seasonal variation of the fish assemblage abundance was detected, with higher values in autumn showing a positive correlation with temperature. Species that complete their life cycle in the Río de la Plata estuary, some of which are relevant to fisheries (64% of the analyzed species) were captured in the Solís Chico subestuary. The importance of this environment as a transitional system for some estuarine fish species is advised.

Disease onset in familial and sporadic multiple sclerosis in Argentina

The present study was carried out to assess if there is an anticipation of age at onset in younger generations of familial multiple sclerosis (FMS) vs. sporadic MS (SMS) in Argentina.

METHODS

multicenter study that included patients from 14 MS Centers of Argentina. Patients were considered as FMS if they had in their family at least one relative of first or second degree diagnosed with MS; otherwise, patients were considered to have SMS. We compared the age at onset between familial and sporadic cases as well as the age at onset between relatives from different generations in FMS vs. SMS.

RESULTS

1333 patients were included, 97 of them were FMS (7.3%). A lower age at onset in the younger generations of FMS cases was found compared with older generations of FMS as well as. SMS cases (24.1±3.7 years vs. 30.3±5.7 years, and 32.4±9.4 respectively; p<0.001). No differences were observed between older generations of FMS vs. SMS cases (p=0.12).

CONCLUSION

we observed an anticipation of age at onset of MS in younger generations of patients with FMS vs. older generations of FMS and SMS.

Cadmium chronotoxicity at pituitary level: effects on plasma ACTH, GH, and TSH daily pattern

Cadmium is an endocrine disruptor that has been shown to induce chronotoxic effects. The present study was designed to evaluate the possible cadmium effects on the daily secretory pattern of adrenocorticotropin hormone (ACTH), growth hormone (GH), and thyroid-stimulating hormone (TSH) in adult male Sprague-Dawley rats. For this purpose, animals were treated with cadmium at two different doses [25 and 50 mg/l cadmium chloride (CdCl(2))] in the drinking water for 30 days. Control age-matched rats received cadmium-free water. After the treatment, rats were killed at six different time intervals throughout a 24-h cycle. Cadmium exposure modified the 24-h pattern of plasma ACTH and GH levels, as the peak of ACTH content between 12:00 and 16:00 h in controls appeared at 12:00 h in the group treated with the lowest dose used, while it appeared between 16:00 and 20:00 h in rats exposed to 50 mg/l CdCl(2). In addition, the peak of GH content found at 04:00 h in controls moved to 16:00 h in rats exposed to 25 mg/l CdCl(2), and the highest dose used abolished 24-h changes of GH secretion. The metal treatment did not modify ACTH secretory pattern. Exposure to cadmium also increased ACTH and TSH medium levels around the clock with both doses used. These results suggest that cadmium modifies ACTH and TSH medium levels around the clock, as well as disrupted ACTH and GH secretory pattern, thus confirming the metal chronotoxicity at pituitary level.

Cadmium effects on 24h changes in glutamate, aspartate, glutamine, GABA and taurine content of rat striatum

This work evaluates the possible changes in 24 h variations of striatal aspartate, glutamate, glutamine, gamma-aminobutyric acid (GABA) and taurine content after oral cadmium treatment. Male rats were submitted to cadmium exposure at two doses (25 and 50 mg/L of cadmium chloride (CdCl(2))) in the drinking water for 30 days. Control rats received cadmium-free water. After the treatment, rats were killed at six different time intervals throughout a 24 h cycle. Differential effects of cadmium on 24 h amino acid fluctuations were observed. Metal exposure modified the daily pattern of the amino acids concentration found in control animals, except for GABA and taurine with the lowest dose used. Exposure to 25 mg/L of CdCl(2) decreased mean content of aspartate, as well as GABA concentration. These results suggest that cadmium exposure affects 24 h changes of the studied amino acids concentration in the striatum, and those changes may be related to alterations in striatal function.

Cadmium chloride exposure modifies amino acid daily pattern in the mediobasal hypothalamus in adult male rat

The present study was conducted to investigate the possible effects of cadmium exposure on the daily pattern of aspartate, glutamate, glutamine, gamma-aminobutyric acid (GABA) and taurine levels in the mediobasal hypothalamus of adult male rats. For this purpose, animals were treated with cadmium at two different exposure doses (25 and 50 mg l(-1) of cadmium chloride, CdCl(2)) in the drinking water for 30 days. Control age-matched rats received CdCl(2)-free water. After the treatment, rats were killed at six different time intervals throughout a 24 h cycle. CdCl(2) exposure modified the amino acid daily pattern, as it decreased aspartate, glutamate, GABA and taurine levels at 12:00 h with both exposure doses employed. In addition, the treatment with 25 mg l(-1) of CdCl(2) induced the appearance of minimal values at 16:00 h and maximal values between 04:00 and 08:00 h for glutamate, and a peak of glutamine content at 20:00 h. The heavy metal also decreased GABA medium levels around the clock in the mediobasal hypothalamus. However, CdCl(2) did not alter the metabolic correlation between glutamate, aspartate, glutamine and GABA observed in control animals. These results suggest that CdCl(2) induced several alterations in aspartate, glutamate, glutamine, GABA and taurine daily pattern in the mediobasal hypothalamus and those changes may be related to alterations in hypothalamic function.

Relationship between blood concentrations of heavy metals and cytogenetic and endocrine parameters among subjects involved in cleaning coastal areas affected by the 'Prestige' tanker oil spill

The sinking of the 'Prestige' oil tanker in front of the Galician coast (NW of Spain) in November 2002 offered a unique opportunity to analyze intermediate cytogenetic and endocrine effects among people exposed to the complex mixture of substances that oil constitutes, including several toxic heavy metals. In this work we evaluated the relationship between exposure to heavy metals (blood concentrations of aluminium, cadmium, nickel, lead and zinc) and genotoxic parameters (sister chromatid exchanges, micronucleus test and comet assay) or endocrine parameters (plasmatic concentrations of prolactin and cortisol) in subjects exposed to 'Prestige' oil during cleaning tasks developed after the spillage. Concentrations of lead were significantly related to the comet assay even after adjusting by age, sex and smoking. Cortisol concentrations were significantly influenced by aluminium, nickel (both, inversely) and cadmium (positively). Women had clearly higher concentrations of prolactin and cortisol, even when adjusting by age, smoking, cadmium, aluminium or nickel. Plasmatic cortisol was jointly influenced by gender, smoking and aluminium or nickel (all p<0.05). In women there was a strong relationship between concentrations of cadmium and prolactin (beta=0.37, p=0.031). When the effects of cadmium, aluminium and nickel on cortisol were simultaneously assessed, only the latter two metals remained statistically significant. Among parameters analysed, cortisol appeared to be the most sensitive to the effects of metal exposure. Plasma levels of cortisol deserve further evaluation as a potentially relevant biomarker to assess the effects of exposure to heavy metals.

Toxic effects of methoxychlor in rat striatum: modifications in several neurotransmitters

Neurotoxic effects of methoxychlor (MTX) are poorly understood at present. This study was undertaken to evaluate the possible effects of MTX in norepinephrine, dopamine and amino acid contents and serotonin turnover in rat striatum. For this purpose, adult male Sprague-Dawley rats were administered 25 mg/kg/day of MTX in sesame oil or vehicle only for 30 days. The neurotransmitters of interest were measured in the striatum by HPLC. MTX decreased norepinephrine and 5-hydroxyindole acetic acid (5-HIAA) content and serotonin turnover (measured as 5-HIAA/serotonin ratio), and increased glutamate and GABA concentrations. However, the content of serotonin, aspartate, glutamine and taurine was not modified by MTX exposure. These data suggest that MTX exposure inhibits norepinephrine synthesis and serotonin metabolism. The inhibitory effect on norepinephrine could be explained, at least in part, by the increase of both GABA and glutamate contents. Further studies are needed to understand the effects of MTX on serotonin. Also a disruptive effect of MTX on the metabolisms of glutamate, aspartate, glutamine and GABA emerges.

Effects of in utero and lactational exposure to endosulfan in prefrontal cortex of male rats

The possible neurotoxic effects of the organochlorine pesticide endosulfan have been evaluated on male offspring rats exposed in utero and during lactation. Dams were treated with 0.61mg or 6.12mg endosulfan/(kgday) from the gestation beginning until the weaning. Male offspring rats were sacrificed at post-natal days (PND) 15, 30 and 60, and possible alterations in the content and metabolism of biogenic amines and amino acids were determined in prefrontal cortex using high-performance liquid chromatography (HPLC). Globally, endosulfan induced an increase in amino acid content in prefrontal cortex at PND 15 and PND 30. However, the levels of GABA at PND 15 and those of glutamine at PND 30 were not modified. At PND 60, a significant reduction in the content of GABA and taurine was observed, while the concentration of glutamate, aspartate and glutamine remained constant. Endosulfan did not modify norepinephrine and dopamine content, but serotonin concentration was increased at PND 30 and PND 60 and serotoninergic and dopaminergic metabolism was also modified. These results suggest that pre- and post-natal exposure to endosulfan affects biogenic amines and amino acids in prefrontal cortex, and those variations could be related to several alterations in the functions in which the prefrontal cortex is involved.

Plasma membrane Ca2+ pump in rat brain. Patterns of alternative splices seen by isoform-specific antibodies

The expression at the protein level of plasma membrane calcium pump (PMCA) isoforms in rat brain was detected by new antibodies that distinguished the four gene products and their alternatively spliced variants. All four gene products were distributed throughout hippocampus, cortex, and cerebellum, but the alternate splices showed more distinct distribution patterns. The b splice of isoform 1 was not detectable in any of the brain regions, which makes it unlikely that this isoform performs an essential housekeeping role as is frequently proposed. The b splices of isoforms 3 and 4, although expressed in all three regions, showed evidence of proteolysis, which removed a portion of the carboxyl terminus. In contrast, isoform 2b retained its full length, indicating that PMCA2b is more resistant to proteolysis than the other b forms. Whereas substantial amounts of isoforms 1a, 2a, and 3a were expressed in all regions, 4a was found only in frontal cortex. The distinct patterns of expression of the PMCA isoforms in brain suggest that some of them play a special role in intracellular Ca regulation.

Cellular and segmental distribution of Ca2(+)-pump epitopes in rat intestine

We used a monoclonal antibody (5F10) specific for the human erythrocyte plasma membrane Ca(++)-pump to demonstrate the presence and distribution of Ca(++)-pump epitopes in rat intestine. In paraffin embedded tissue sections, antibody 5F10 binds to epitopes in the basolateral membranes of absorptive cells in rat duodenum and portions of jejunum but not ileum. Western blot analysis of intestinal mucosal proteins with antibody 5F10 shows binding of antibody to major bands of Mr approximately 135,000 and Mr approximately 72,000, and to lesser bands of Mr approximately 125,000 and Mr approximately 27,000. This pattern was seen in mucosal homogenates of rat duodenal and jejunal cells and to a lesser extent in ileal cells. The Mr approximately 135,000 band corresponds to the molecular weight of Ca(++)-pumps in other tissues. The other bands correspond in size to known proteolytic fragments of the Ca(++)-pump. Slot-blot analysis of nitrocellulose immobilized mucosal homogenates shows binding of 5F10 to be greatest in duodenum and least in ileum. Ca(++)-transport studies by the everted gut sac technique show a correlation between vitamin D induction of active Ca(++)-transport and the segmental distribution of Ca(++)-pump epitopes.

Plasma membrane calcium pump and 28-kDa calcium binding protein in cells of rat kidney distal tubules

In an effort to extend our studies on Ca2+ pumps to animal models, we developed a new monoclonal antibody (5F10) prepared against the human erythrocyte Ca2+-Mg2+-adenosinetriphosphatase (ATPase) that recognizes a protein of approximately 140 kDa in rat kidney homogenates. Enzyme-linked immunosorbent assays show that monoclonal antibody 5F10 binds purified Ca2+-Mg2+-ATPase and rat kidney membrane extracts in a concentration-dependent manner. In paraffin-embedded tissue sections, antibody 5F10 binds to an epitope in the basolateral membranes of rat kidney distal convoluted tubule principal cells. The antibody does not bind to intercalated cells. The latter cells were characterized by the presence of large amounts of carbonic anhydrase C. Polyclonal antibodies directed against chick intestinal 28-kDa vitamin D-dependent calcium binding protein (28-kDa CaBP) also bind epitopes in distal convoluted tubule cells, connecting tubules, and portions of collecting duct but not intercalated cells. Western blot and 45Ca blot analysis of renal cytosolic proteins showed that the polyclonal 28-kDa CaBP-directed antibody detects a protein which also binds calcium. Western blot analysis with monoclonal antibody 5F10 shows binding to both the authentic purified erythrocyte Ca2+ pump (approximately 138 kDa) and to tryptic fragments of this pump. Antibody JA3, previously used for staining of human kidney tubules, reacts with a different set of tryptic fragments, showing that the two antibodies are directed against different regions or conformational determinants on the pump molecule. We show that Ca2+-Mg2+-ATPase and 28-kDa CaBP are present in the principal cells of the distal convoluted tubule of the rat and are absent in intercalated cells.(ABSTRACT TRUNCATED AT 250 WORDS)

Calcium pump epitopes in placental trophoblast basal plasma membranes

The syncytiotrophoblast represents the primary cellular barrier between maternal and fetal circulations in the placenta. Large amounts of Ca2+ are transported across this barrier by mechanisms that are not clearly understood. To further understand this phenomenon, we examined rat and human placenta by immunohistochemical and protein blotting techniques with a monoclonal antibody raised against the human erythrocyte plasma membrane Ca2+ pump. Immunohistochemistry with this antibody showed specific staining in the human placenta of the basal (fetal facing) surface of the syncytiotrophoblast. In the rat placenta, immunohistochemistry also showed specific staining of the innermost (fetal facing) layer of the trophoblast and the basal surface of the endoderm of the intraplacental yolk sac. In Western blots of placental homogenates and membranes, the monoclonal antibody bound to a 140,000-mol wt band, characteristic of Ca2+ pumps in other tissues. Western blots of isolated basal membranes showed more intense staining than isolated microvillous membranes, confirming the results of the immunohistochemistry. In addition, Ca2+ transport in basal membrane vesicles from human placenta was inhibited by polyclonal antibodies prepared against the erythrocyte Ca2+ pump. We conclude that basal (fetal facing) layers of human and rat placentas contain a high-affinity Ca2+ pump situated to transport Ca2+ from the maternal to the fetal circulation.