Genetic differentiation between two species of the medicinal leech,<Emphasis Type="Italic"> Hirudo medicinalis</Emphasis> and the neglected<Emphasis Type="Italic"> H. verbana</Emphasis>, based on random-amplified polymorphic DNA

The medicinal leech is one of the few parasitic invertebrates widely used in medicine and as a scientific model object. Because of a dramatic decline in its natural populations, it is subject to considerable conservation effort. Despite all attention, there is confusion regarding the taxonomic status of different morphological forms. The prevailing view is that all varieties of medicinal leech in Europe represent the same species, Hirudo medicinalis. However, the present study based on RAPD molecular markers demonstrates that a second European taxon, H. verbana, forms a distinct species. Phenetic clustering and principal coordinate analysis of eight populations revealed the same basic structure, reflecting taxonomic rather than geographic subdivision. Variation between species explained 60% of the total molecular variance (_CT=0.60, P<0.001). Both taxa displayed a significant number of specific RAPD markers. Conversely, no specific fragment supporting the geographic association of both taxa was found. Since the stronghold of commercially exploited medicinal leech populations in southeastern Europe and Turkey belongs to H. verbana, most medicinal and scientific applications probably use this species, not H. medicinalis. Appropriate taxonomic correction of international conservation conventions and legislation is essential.     

Heat shock proteins (HSPs) 27, 72 and 73 in normal and pre-ulcerative mucosa of the gastric pars oesophagea in swine

Heat shock proteins (HSPs), known to play a key role in cellular homeostasis, may also play a role in the defensive mechanisms of gastric mucosa. By means of appropriate immunohistochemical and immunobiochemical techniques, the expression of HSP27, HSP72 and HSP73 within the epithelium of normal and pre-ulcerative (hyperkeratinized) mucosa of the pars oesophagea of abattoir pigs was assessed. In normal mucosa, HSP72 and HSP73 expression was mainly limited to the basal epithelial cell layer, whereas HSP27 expression was consistently detected within the superficial epithelial cell layers. In hyperkeratinized mucosa, HSP72 and HSP73 immunoreactivity appeared to be more widespread, becoming very intense within epithelial cells affected by hydropic degeneration. Hyperkeratinized mucosa also showed HSP27 immunoreactivity, which was particularly intense in epithelial areas affected by hydropic degeneration. Western blot analysis confirmed HSP27, HSP72 and HSP73 expression in normal and in pre-ulcerative mucosa of the pars oesophagea. Semi-quantitative analysis showed that for all three HSPs the immunoreactivity was more intense in pre-ulcerative mucosa than in normal mucosa. The different expression patterns observed may have functional significance; further studies are needed, however, to define the role of HSPs in swine oesophagogastric lesions, the aetiology and pathogenesis of which are largely unknown.     

Myoid hamartomas of the breast: report of 3 cases and review of the literature

Hamartomas were first described by Albrecht in 1904, who defined them as tumor-like malformations in which there was abnormal blending of the normal components of an organ. The myoid hamartoma is a rare benign lesion of the breast and has an uncertain origin, possibly in the walls of the blood vessels, muscularis mammillae of the areolae, and mainly in myoepithelium. We report 3 cases of myoid hamartomas of the breast, with the clinical, radiologic, and histopathological findings, and review the literature. The 3 lesions showed normal breast ducts and lobules, entrapped by a muscular stroma and some foci of mature adipose tissue. The muscular origin of part of the stroma was confirmed by strong reactiveness with smooth-muscle actin.     

Somatic mosaicism for a MECP2 mutation associated with classic Rett syndrome in a boy

Rett syndrome is a severe neurodevelopmental disorder that arises from mutations in the X-linked MECP2 gene. It is almost exclusively seen in girls due to the predominant occurrence of the mutations on the paternal X-chromosome, and also the early postnatal lethal effect of the disease causing mutations in hemizygous boys. We identified a boy with features of classic Rett syndrome who is mosaic for the truncating MECP2 mutation R270X. Chromosome analysis showed normal karyotype. These results indicate that a MECP2 mutation associated with Rett syndrome in females could lead to a similar phenotype in males as a result of somatic mosaicism.     

Effects of L-carnitine on neutrophil functions in aged rats

Several age-related alterations occur at the cellular level in the immune system leading to a decrease in the immune response. The present study was designed to determine the effect of L-carnitine on impaired neutrophil functions of aged rats. For this reason, superoxide anion radical production, chemotaxis and phagocytic activity were studied in the neutrophils obtained from the peripheral blood of young and old rats. We orally gavaged L-carnitine (50 mg/kg b.w. per day) or control vehicle into young (2 months) and aged (24 months) rats for 30 consecutive days. The neutrophils of aged rats exhibited an increase in superoxide anion production and decline in phagocytosis and chemotaxis when compared with that in young rat neutrophils. Superoxide anion production in aged rats was significantly decreased by L-carnitine treatment which was accompanied with a significant enhancement of chemotactic and phagocytic activity being restored to control levels. These findings demonstrated that L-carnitine is capable of restoring the age-related changes of neutrophil functions.     

Genetic diversity among clinical isolates of Candida glabrata analyzed by randomly amplified polymorphic DNA and multilocus enzyme electrophoresis analyses

The genetic diversity of 47 clinical and reference strains of Candida glabrata from several geographical origins and diverse clinical disorders, with different antifungal susceptibilities, as well as their genetic relationships were studied through multilocus enzyme electrophoresis (MLEE) and randomly amplified polymorphic DNA (RAPD) techniques. The genetic diversity estimated for 11 MLEE loci measured as average heterozygosity (h) was 0.055. A high level of genetic relatedness among isolates was established by cluster analysis. Forty-nine RAPD markers were analyzed, and the average genetic diversity among isolates, estimated by Shannon's index (Ho), was 0.372. The PhiST values estimated through an analysis of molecular variance to assess genetic differentiation among isolates revealed no genetic differentiation among them. Our results revealed very low genetic diversity among isolates, a lack of differentiation, and no association with their geographic origin and the clinical characteristics.     

Seasonal malaria transmission and variation of anopheline density in two distinct endemic areas in Brazilian Amazonia

Studies on seasonal anopheline fauna variation were performed in two distinct settlements in the State of Rond?nia, Brazil: one at the Madeira River banks (Portuchuelo) with stable native Amazonian population; the other at an inland lumber-extracting farm (Urupá) in dry land, in which adults are mostly migrants. During a 6-yr period (1994-2000), 8,638 adult anophelines were collected: 2,684 in Urupá and 5,954 in Portuchuelo. Anopheles darlingi represented >95% of total mosquitoes caught. Dissection of 4,424 A. darlingi females yielded a very low sporozoite infection index below 0.1%. Oocysts were found in both localities in approximately 0.1% of dissected mosquitoes. Determination of the hour biting rates disclosed seasonal variations in both localities. However, in Portuchuelo, mosquito density peaked at the acme of the rainy season, whereas at Urupá it peaked in the dry season. The increase in mosquito density and incidence of malaria cases were coincident. The high mosquito densities observed in the riverine settlement of Portochuelo sector B, which permits evaluation in > 10,000 mosquitoes' bites/person/year, could explain, in spite of the low mosquito's infection index, the previously described development of natural immunity in the local population that is not observed in the dry land agroindustrial settlement of Urupá.     

Cardiac troponins following repeated administration of an iron chelator--salicylaldehyde isonicotinoyl hydrazone (SIH)--in rabbits

Both cardiac troponin T (cTnT) and cardiac troponin I (cTnI) are considered to be reliable biomarkers with sufficient sensitivity and specificity for cardiac injury in the majority of laboratory animals. The aim of our study was to compare the diagnostic performance of cTnT and cTnI in three groups of rabbits: 1) control (saline 1 ml/kg i.v.); 2) Salicylaldehyde Isonicotinoyl Hydrazone--SIH (50 mg/kg, once weekly, i.p.; partially dissolved in 10% Cremophor solution); 3) 10% Cremophor solution in water (2 ml/kg i.v.). The drugs were given once a week, 10 administrations. The concentration of cTnT was measured using Elecsys Troponin T STAT Immunoassay (Roche). The concentration of cTnI was measured using AxSYM Troponin I (Abbott). The linear regression model was applied to see if there is a dependence between cTnT and cTnI. The coefficient of determination was not acceptable in all groups. The highest value of R2 was found in the control group (R2 = 0.424). We may conclude that in rabbits meaningful dependence between cTnT and cTnI was not found. According to our long-term experiences cTnT seems to be more suitable cardiomarker in rabbits in comparison with cTnI where the data are characterized by the large scatter.     

Random coil dimensions of poly(1-hexadecene)

The characteristic ratios of three samples of poly(1-hexadecene) with different tacticities were evaluated from intrinsic viscosity and molecular weight data obtained with a size exclusion chromatograph with dual (concentration plus viscosity) detector. No significant differences were found for the characteristic ratio in the studied range of tacticities. Theoretical calculations for the unperturbed dimensions were also performed for these samples by using the rotational isomeric state model, and compared with the experimental results.     

Multivariate Base Rates of Low Scores on Tests of Learning and Memory among Spanish-Speaking Children

ABSTRACT

To determine the prevalence of low scores on two neuropsychological tests commonly used to evaluate learning and memory in children. 6,030 healthy children from 10 countries in Latin America and Spain were administered Rey–Osterrieth Complex Figure (ROCF) and the Test de Aprendizaje y Memoria Verbal–Infantil (TAMV-I). Results showed that low scores are common when multiple neuropsychological outcomes (tests and/or scores) are evaluated in healthy individuals. Clinicians should consider the higher probability of low scores in a given individual when evaluating learning and memory using various sets of scores to reduce false-positive diagnoses of cognitive deficits in pediatric populations.