Does the cerebellar sequential theory explain spoken language impairments? A literature review.

During the past decades, converging evidence from clinical, neuroimaging and neuroanatomical studies has demonstrated the key role of the cerebellum in the processing of non-motor aspects of language. Although more is known about the way in which the cerebellum participates in the mechanisms involved in written language, there is ambiguous information on its role in other aspects of language, such as in non-motor aspects of spoken language. Thus, to contribute additional insight into this important issue, in the present work, we review several original scientific papers focusing on the most frequent non-motor spoken language impairments evidenced in patients affected by cerebellar pathology, namely, verbal working memory, grammar processing and verbal fluency impairments. Starting from the collected data, we provide a common interpretation of the spoken language disorders in cerebellar patients, suggesting that sequential processing could be the main mechanism by which the cerebellum participates in these abilities. Indeed, according to the cerebellar sequential theory, spoken language impairments could be due to altered cerebellar function to supervise, synchronize and coordinate the activity of different functional modules, affecting the correct optimization of linguistic processing.

Functional Changes of Mentalizing Network in SCA2 Patients: Novel Insights into Understanding the Social Cerebellum.

In recent years, increasing evidence of the cerebellar role in social cognition has emerged. The cerebellum has been shown to modulate cortical activity of social brain regions serving as a regulator of function-specific mentalizing and mirroring processes. In particular, a mentalizing area in the posterior cerebellum, specifically Crus II, is preferentially recruited for more complex and abstract forms of social processing, together with mentalizing cerebral areas including the dorsal medial prefrontal cortex (dmPFC), the temporo-parietal junction (TPJ), and the precuneus. In the present study, the network-based statistics approach was used to assess functional connectivity (FC) differences within this mentalizing cerebello-cerebral network associated with a specific cerebellar damage. To this aim, patients affected by spinocerebellar ataxia type 2 (SCA2), a neurodegenerative disease specifically affecting regions of the cerebellar cortex, and age-matched healthy subjects have been enrolled. The dmPFC, left and right TPJ, the precuneus, and the cerebellar Crus II were used as regions of interest to construct the mentalizing network to be analyzed and evaluate pairwise functional relations between them. When compared with controls, SCA2 patients showed altered internodal connectivity between dmPFC, left (L-) and right (R-) TPJ, and right posterior cerebellar Crus II.The present results indicate that FC changes affect a function-specific mentalizing network in patients affected by cerebellar damage. In particular, they allow to better clarify functional alteration mechanisms driven by the cerebellar damage associated with SCA2 suggesting that selective cortico-cerebellar functional disconnections may underlie patients' social impairment in domain-specific complex and abstract forms of social functioning.

Osteomielitis aguda y crónica: 10 años de estudio en pacientes pediátricos: Hospital de Niños J.M. de Los Ríos Caracas Venezuela / Acute and chronic osteomyelitis: 10 years of study in pediatric patients: Hospital de Niños

La osteomielitis constituye un proceso inflamatorio común del hueso. Existen factores que influyen en la incidencia y etiología tales como: estado inmunologógico, edad, sexo, traumatismo locales o enfermedades de base. A pesar de su relativa baja frecuencia es una de las principales causas infecciosas de hospitalización prolongada. Describir las características de pacientes con diagnóstico de osteomielitis egresados del Hospital de Niños J.M. de Los Ríos (HJMR) y establacer prevalencia según egresos hospitalarios. Estudio retrospectivo mediante revisión de historias médicas, descriptivo en menores de 18 años con diagnóstico de osteomielitis del Hospital de Niños "J.M. de Los Ríos", período diciembre 1998 - diciembre 2008. Análisis estadístico: medidas tendencias central y Chi cuadrado. Se revisaron 72 historias, 65,3% (47/72) masculino y 34,7% (25/72) femenino. Prevalencia de 0,14 por cada 100 egresados. Según edad 8,33% (6/72) lactantes menores 5,56% (4/72) lactantes mayores, 29% (20/72) preescolares, 29% (20/72) escolares y 27,8% (20/72) adolescentes. Promedio días hospitalización fue 42,5 ± 20,75. El 27,8% (20/72) presentaba alguna patología de base. Sitios afectados 37,5% (27/72) fémur, 23% (17/72) tibia, 6,9% (5/72) calcáneo, 6,94% (5/72) cadera y otros lugares 25% (18/72). En 45,83% (33/72) se realizó limpieza quirúrgica, en promedio a los 26,% días del ingreso (DE ± 33). el 62,5% (45/72) fueron ostemielitis agudas y 37,5% (27/72) crónica. El aislamiento micronbiológicos se logró con mayor frecuencia en el grupo de pacientes con osteomielitis crónica (P < 0,05). Un 11,11% (8/72) presentó algún tipo de secuela y 12,5% (9/72) infección nosocomial. La osteomielitis en niños tiene una prevalencia relativamente baja, pero genera hospitalizaciones prolongadas con importantes complicaciones médicas y quirúrgicas.

Osteomyelitis represents a common inflammatory process of the bone. Immnologic status, age , sex, traumatic lesions and co morbidities influence the etiology and comorbidities influence the etiology and incidence of the disease. It is one of the most important infectious causing prolonged hospitalizations. Describe the characteristics of children with osteomyelitis from J.M. de Los Ríos Children`s Hospital and calculate its prevalence. Retrospective and descriptive study through medical charts revision, including patients less than 18 years old with osteomyelitis as discharged diagnostic at Children Hospital J.M. de Los Ríos between December 1998 - December 2008. Seventy two chart were revised, 65.3% (47/72) male and 34.7% (25/72) female. The prevalence by 100 dischages by age was 8.3% (6/72) infants, 5.6% (4/72) children, 29% (20/72) pre-school children, 29% (20/72) scholer children, and 27.8% (20/72) adolescents. The average hospitalization time was 42.63 ± 20.75. Twenty of 77 children (27.8%) presented with some co morbidities. The affected bones were: 37.5% (27/72) femur, 23% (17/72) tepid bone, 6.9% (5/72) calcaneus, 6.9% (5/72) hip and others 25% (18/72). In 45.8% (33/72) the resolution was surgery, with an average of 26.5 days of hospitak stay (DE ± 24.33); 62.5% (45/72) were acute osteomyelitis, and 37.5% (27/72) chronic. The microbiologic diagnostic was more frequent in the group of chronic (p < 0.05). Sequel were present in 11% (8/72), and nosocomial infection in 12.5% (9/72). Osteomyelitis children has a relative small prevalence, but it generates prolonged hospitalizations with important complications.

Profilaxis universal para citomegalovirus en pacientes pediátricos con trasplante renal / Universal prophylaxis for cytomegalovirus in pediatric renal transplant patients

Citomegalovirus (CMV) es el agente infeccioso más importante entre los receptores de trasplante renal. La infección ocurre entre el segundo y sexto mes después del trasplante. Dada la implicación del CMV en la evolución del trasplante renal es necesario el uso racional de tratamiento antivirales. En nuestro medio la realización de antigenemia para CMV resulta costosa y no disponible en instituciones públicas, por lo que se administra profilaxis a todos los pacientes trasplantados. Describir evolución clínica de pacientes pediátricos con trasplante renal quienes recibieron profilaxis universal para citomegalovirus. Estudio descriptivo, retrospectivo, en pacientes trasplantados relanes del Hospital de Niños J.M. de Los Ríos, período enero 2008 julio 2009 quienes recibieron profilaxis universal para CMV. Se describe la evolución de dichos pacientes en los primeros 6 meses postrasplante, evaluando signos/síntomas que sugirieren enfermedad por CMV. Se realizó comparación estadística entre dos grupos de pacientes según seropositividad para CMV, determinando medidas de tendencias central , prueba Chi cuadrado. Se estuadiaron 20 pacientes, 18 (90%) sexo femenino y 2 (10%) masculino. Edad `promedio 12,9 años (DE±3,2). Patología base: 10 com glomerulopatía (50%) y 10 (50%) malformación sistema urinario. De total, 14 (70%) tenían IgG positiva para CMV; donantes 19 (95%). En 6 (30%) receptor negativo, donante seropositivo (R-/D+). Uno de los individuos (5%) evolucionó tórpidamente, el resto 19 (95%) no presentó síntomas, alteraciones hematológicas y/o de química sanguínea compatible con enfermedad por CMV. En el grupo R-/D+ el porcentaje de rechazo fue 50% (3/6) y en el grupo R±/D± 42,9% (3/14), sin diferencia estadísticamente significativas. La mayoría de los pacientes se mantuvieron sin manifestaciones compatibles con enfermedad por CMV al recibir profilaxis universal.

Cytomegalovirus (CMV) is the most important infection agent in renal transplant recipients. Infection occurs between the second and the sixth month posttransplant. Because of the importance of the CMV in the course of renal transplant, it is neccesary the rational use of antiviral treatments. In our hospitals, the practice of antigenemia for CMV is of high cost and it cannot be performed in public institutions, and the regular practice is to provide universal prophylaxis to transplant patients. To describe clinical cource of pediatrics patients with renal transplant who received iniversal prophylaxis for CMV. Descriptive and retrospective study, including kidney transplanted patients admitted in the Children Hospital J.M. de Los Ríos, from January 2008 to July 2009, who received universal prophylaxis for CMV. Description of patients outcome during the first six months after transplantation, evaluating signs and symptoms of probable CMV. Comparisons between two groups of patients taking into account the seropositivity for CMV. Meassurement of central tendency, Chi square. Twenty patients were included, 18 (90%) women, and 2 (10%) men. Mean age 12.9 years (DE ± 3.2). Co morbidities were glomerulopathy 50% (10) and malformations of the urinary tract 50%. Of the total, 70% (14) were positive for IgG CMV; 95% of donors (19). In 6 (30%) the receptor was negative, and the donor positive (R-/ D+). One of the patients presented a tropid outcome, while the others (95%) were clinically well with no laboratory abnormalities. In the group R-/D+ the percentage of kidney rejection was 50% (3/6) and in the group R+/D+42,9%(3/14), without statistical significant difference. Most of the patients did not have clinical signs of CMV sickness while receiving universal prophylaxis.

Chemoprotective effect of Spirulina (Arthrospira) against cyclophosphamide-induced mutagenicity in mice.

The aim of this study was to investigate the antimutagenic effects of Spirulina (SP) on male and female mice by the dominant lethal test using cyclophosphamide (CP) as a mutagen. Animals of both sex were given SP orally at 0, 200, 400 or 800 mg/kg body weight (b.w.) for 2 weeks prior to starting the CP treatment. CP was i.p. injected daily for 5 days at 40 mg/kg b.w. For the male-dominant lethal test, each male was caged with untreated females per week for 3 weeks. For the female-dominant lethal test the above doses and schedule treatments were used and treated females were caged for one week with untreated males (1-2). On days 13-15 after breeding was |started all the females were evaluated for incidence of pregnancy, total corpora lutea, total implants and pre- and post-implant losses. In the male-dominant lethal test, the CP induced pre- and post-implant losses in untreated females were inhibited at all SP doses. In the female-dominant lethal test only post-implantation losses were prevented at the same doses. Semen examination of a separate group of mice showed that SP improved its quality. Our results illustrate protective effects of SP in relation to CP-induced genetic damage to germ cells.

Infecciones asociadas a catéteres vasculares de larga permanencia en pacientes pediátricos con cáncer / Infections associated to vascular catheters of long permanency in patient pediatric with cancer

La disponibilidad de catéteres intravasculares permanentes para manejo de pacientes pediátricos con cáncer facilita el tratamiento quimioterápico y disminuye la morbilidad; sin embargo, las infecciones asociadas constituyen una causa importante de bacteremia nosocomial. Conocer la incidencia de infecciones asociadas a catéteres vasculares de larga permanencia en pacientes pediátricos oncológicos. Estudio descriptivo, petrospectivo y transversal mediante el cual se determinó la frecuencia de infecciones asociadas a catéteres en pacientes pediátricos con cáncer hospitalizados en el Servicio de Oncología del Hospital "J.M de Los Ríos", evaluados por infectología, entre enero de 2000 y diciembre de 2004. Se determinó la relación entre tipo de catéter (con o sin reservorio) y factores como frecuencia de infección, nivel socioeconómico, tiempo entre implantación e infección, tipo de infección, microorganismos involucrados y permanencia hospitalaria. Se implantaron 24 catéteres en 16 pacientes: 5 con reservorio y 19 sin reservorio. Se presentó un episodio de infección (candidemia) en los pacientes con catéteres con reservorio, mientras que hubo 11 infecciones en los otros (7 bacteriemias, 1 candidemia, 2 infecciones en sitio de implantación y 1 infección combinada), aislándose principalmente bacterias gramnegativas y Candida sp.). Todos presentaron fiebre. Las infecciones ocurrieron en 12/16 pacientes con condiciones socioeconómicas menos favorables. El lapso entre implantación e infección fue variable. Las infecciones asociadas a catéteres vasculares son menos frecuentes en aquellos con reservorio. La bacteremia fue el tipo de infección más reportada. Los microorganismos gramnegativos fueron los más involucrados. El 50 por ciento de los pacientes estuvo hospitalizado menos de 33 días.

Antioxidant capacity in seminal plasma of transfusion-dependent beta-thalassemic patients.

BACKGROUND: Homozygous beta-thalassemia is a haemolytic disorder with a high potential for oxidative damage, due to the high circulating iron levels. Enzymatic and non enzymatic antioxidant capacities, as well as lipoperoxide content, were investigated in seminal plasma of these patients to evaluate a possible oxidative stress. METHODS: Semen samples from 10 transfusion-dependent beta-thalassemic patients and 18 control subjects were examined. The assessment of the seminal antioxidant capacity included spectrophotometrical assays for determination of superoxide dismutase and catalase activity and of the total antioxidant status value. Furthermore, malondialdehyde level was detected as marker of lipoperoxidation. RESULTS: All the beta-thalassemic patients showed high serum ferritin levels, progressive sperm motility below 50 %, and normal sperm count (median: 43 x 10 (6) sperm/ml). Increased superoxide dismutase ( p < 0.01) and catalase ( p < 0.001) activities, but unaltered total antioxidant status values, were detected in the patients' seminal plasma. Furthermore, augmented malondialdehyde levels ( p < 0.001) were measured in the patients. CONCLUSIONS: Seminal antioxidant pattern of iron overloaded beta-thalassemic patients indicated the hyperactivation of the enzymatic free-radical scavengers which could be explained as a compensatory mechanism to possible high levels of reactive oxygen species. Furthermore, the increase of seminal lipoperoxidation suggested an oxidative stress in semen of these patients and it could have contributed to the impairment of sperm motility.

Immunolocalization of estrogen receptor beta in the epididymis of mature and immature pigs.

A growing body of evidence suggests a role of estrogens in the male reproduction via their specific estrogen receptors (ERalpha/ERbeta). Estrogen receptor distribution along the genital tract tissues has been described in different species, but it is unknown in the pig. Therefore, the aim of the present study was to localize ERbeta in the epididymis of mature and immature pigs (aged 2 and 18 months, respectively). Immunohistochemistry was carried out on paraffin-embedded tissues using a mouse anti-human monoclonal IgG against ERbeta as the primary antibody, and a goat anti-mouse biotinylated IgG as the secondary antibody. Avidin-biotin-peroxidase complex was then applied followed by diaminobenzidine. In immature pigs, the epithelial cells from the caput, corpus and cauda epididymis showed no or very weak immunoreactivity for ERbeta, whereas they were all strongly immmunoreactive in mature pigs. A various intensity of immunostaining from weak to strong in the smooth muscle cells as well as in the connective tissue cells were detected in the epididymis of both, young and adult pigs. This is the first report on the cellular localization of ERbeta protein in porcine epidydimis. The present study demonstrated that (1) irrespectively of the epididymal region, the epithelial cells of caput, corpus and cauda epididymis of mature pigs revealed a strong immunoreactivity for ERbeta, and (2) ERbeta expression in the epididymal epithelium is regulated by puberty. Finally, although the biological activity of ERbeta has not yet been established, the results of the present study suggest its involvement in estrogen modulation of pig epididymal function.

Prostasomes as zinc ligands in human seminal plasma.

Prostasomes are small vesicles, containing zinc, secreted by prostate in human seminal plasma and showing a physiological role on sperm properties. In this study, the possible correspondence between prostasomes and a prostatic high molecular weight protein complex, recently indicated as zinc ligand, has been investigated. Isolated prostasomes, examined by scanning electron microscopy, were dialysed to evaluate their zinc binding capacity. Furthermore, seminal plasma Sephadex G-75 elution was carried out before and after prostasome removal. Prostasome preparations, containing typical vesicles of 50-500 nm, showed a positive correlation between their zinc and protein levels. They were able to take up zinc against gradient. Furthermore, the seminal zinc amount, bound to the high molecular weight proteins, was strongly reduced in the free-prostasome sample with respect to the total seminal plasma. This study suggested the correspondence between the prostasomes and a high-sized zinc ligand complex of prostatic origin. Therefore, it demonstrated, for the first time, the zinc binding capacity of prostasomes, a new property which could be related to their biological functions.

Impaired seminal antioxidant capacity in human semen with hyperviscosity or oligoasthenozoospermia.

Antioxidant capacity of seminal plasma was evaluated in 120 semen samples subdivided into asthenozoospermic and oligoasthenozoospermic specimens with normal consistency and into asthenozoospermic and oligoasthenozoospermic specimens with hyperviscosity. Semen samples (n = 25) from normozoospermic donors were used as a control group. Scavenger antioxidant capacity of reactive oxygen species was evaluated by superoxide dismutase and catalase activity measurements, whereas the chain-breaking antioxidant efficiency was detected by total antioxidant status assessment. In semen with normal viscosity, unaltered enzymatic and nonenzymatic antioxidant capacity was revealed in the asthenozoospermic specimens, whereas low superoxide dismutase activity was detected in oligoasthenozoospermic samples. On the contrary, impairment of both the scavenger and chain-breaking antioxidative systems was revealed in asthenozoospermic and oligoasthenozoospermic hyperviscous ejaculates, regardless of sperm count. Catalase activity and total antioxidant status values were also reduced in the 2 subgroups of hyperviscous ejaculates compared with their respective matched controls, whereas similar superoxide dismutase activities were detected in oligoasthenozoospermic samples with normal and high consistencies. These results suggest that asthenozoospermia could be related to an antioxidant deficiency only in combined ejaculate pathologies, and that a severe impairment of the low and high molecular weight seminal antioxidative capacities could be associated with semen hyperviscosity.

Prostatic origin of a zinc binding high molecular weight protein complex in human seminal plasma.

The profile of the zinc ligand high molecular weight proteins was investigated in the seminal plasma of 55 normozoospermic subjects by size exclusion high performance liquid chromatography (HPLC). The proteins were recovered from Sephadex G-75 gel filtration of seminal plasma in three zinc-containing fractions which were then submitted to HPLC analysis. The results were, that in all the samples, the protein profiles showed two peaks with apparent molecular weight of approximately 660 and approximately 250 kDa. Dialysis experiments revealed that both approximately 660 and approximately 250 kDa proteins were able to uptake zinc against gradient indicating their zinc binding capacity. The HPLC analysis of the whole seminal plasma evidenced only the approximately 660 kDa protein complex as a single well quantifying peak, furthermore a positive correlation between its peak area and the seminal zinc values (P < 0.001) was observed. This suggested a prostatic origin of the approximately 660 kDa protein complex which was then confirmed by the seminal plasma HPLC analysis of a subject with agenesis of the Wolffian ducts. Finally the study demonstrated the presence of two zinc binding proteins, approximately 660 and approximately 250 kDa respectively, in human seminal plasma and the prostatic origin of the approximately 660 kDa.

Unaltered protein pattern/genital tract secretion marker levels in seminal plasma of highly viscous human ejaculates.

SDS-PAGE (12.5%) analysis and neutral alpha-glucosidase, fructose, and zinc level assessment were carried out in seminal plasma of 20 patients with highly viscous ejaculates and of 20 control subjects, with the aim to investigate the relations between high consistency of semen and epididymal, vesicular, and prostatic secretions. Very low sperm motility was observed in all the patients' ejaculates, both normo- and oligozoospermics. Protein patterns obtained in control and highly viscous semina showed similar protein bands, in the range of 10-100 kD. Furthermore, unaltered seminal neutral alpha-glucosidase, zinc, and fructose level were measured in the same specimens. These results indicated no impairment of epididymal, vesicular, and prostatic function in patients with hyperviscous semina, while their normal electrophoretic seminal protein profile suggested unaltered genital fluid interactions during the semen coagulation-liquefaction process.

Low seminal zinc bound to high molecular weight proteins in asthenozoospermic patients: evidence of increased sperm zinc content in oligoasthenozoospermic patients.

Total seminal zinc concentration, seminal zinc fraction bound to high molecular weight proteins (HMW-Zn%) and zinc content in spermatozoa were assayed in the ejaculates of 90 asthenozoospermic patients subdivided into two study groups: normoasthenozoospermics (group I: n = 50) and oligoasthenozoospermics (group II: n = 40). The zinc concentrations of patients were compared with those of a control group of donors showing normal semen parameters. All samples were also investigated for their sperm membrane functional integrity by the hypo-osmotic swelling test (HOS). The results showed normal total zinc concentrations but very low HMW-Zn% values (P < 0.001) in seminal plasma of the two groups of asthenozoospermic patients compared to the controls. Furthermore higher zinc amounts (P < 0.001) were measured in spermatozoa of oligoasthenozoospermic patients compared to group I and to the control group. Oligoasthenozoospermics also displayed a lower HOS score (P < 0.001) compared to the other two groups. These data suggest that the increased unbound seminal zinc could contribute to the decrease of sperm motility in normoasthenozoospermic and oligoasthenozoospermic patients. A further impairment in sperm motility could occur in the oligoasthenozoospermic patients where the increase of seminal free zinc was followed by a major zinc uptake by spermatozoa. The higher intrasperm zinc content in these patients could be a reflection of their low sperm membrane functionality.

Epididymal and sex accessory gland secretions in transfusion-dependent beta-thalassemic patients: evidence of an impaired prostatic function.

Neutral alpha-glucosidase levels as epididymal marker, fructose levels as vesicular marker, zinc, citric acid and prostate specific antigen levels as prostatic markers were measured in the seminal plasma of eight transfusion-dependent beta-thalassemic patients in order to study epididymal and sex accessory gland secretions (eighteen subjects served as controls). FSH and LH as well as total and free testosterone were detected displaying unaltered serum values. Ejaculate of patients showed normal sperm count and low sperm motility, in the meantime seminal plasma exhibited unaltered both neutral alpha-glucosidase and fructose values but low levels of zinc, citric acid and prostate specific antigen were noticed as well. These data suggest an impaired prostatic secretion in the thalassemic patients studied. A local iron toxicity on the prostatic tissue could be supported by the decrease of its specific markers observed only in the subgroup of patients with high ferritin serum levels.

Effects of short-term high-dose testosterone propionate administration on medium molecular-weight proteins of human seminal plasma.

Effects of short-term high-dose testosterone propionate treatment on medium molecular-weight proteins (lactoferrin, albumin, prostatic acid phosphatase, prostate specific antigen) and on zinc and fructose levels were investigated in the seminal plasma of seven normal volunteers. A significant reduction in levels of prostatic-acid phosphatase, zinc and, to a lesser degree, prostate-specific antigen, lactoferrin and fructose was observed on the 14th day of androgen treatment, concomitantly with the maximal increase in free androgen-circulating levels. The data obtained suggest that testosterone administration may induce a reduction in the sex accessory-gland secretion. Indeed, this effect tends to disappear with withdrawal of hormone treatment. Therefore, the authors suggest a close follow-up of prostatic and vesicular function during the long-term high-dose testosterone intake, used frequently as anabolic treatment by athletes and body builders.

Adnexal gland secretion markers in unexplained asthenozoospermia.

Prostatic acid phosphatase, prostate-specific antigen, and zinc as markers of prostate, and fructose as marker of seminal vesicles were investigated in the seminal plasma of 35 idiopathic asthenozoospermic and 20 normal subjects to evaluate their relationship with sperm motility. Total seminal plasma levels of the three prostatic markers and, to a lesser extent, total fructose levels were lower in asthenozoospermic patients, and in all the pooled subjects, the same levels were directly correlated with the motility of ejaculated spermatozoa. When the levels of the biochemical markers were expressed as concentrations in seminal plasma, only prostatic acid phosphatase levels remained lower in asthenozoospermic patients and they maintained a direct correlation with sperm motility in all the pooled subjects. The PAP/Zn/Fr (representing the ratio between PAP concentration and free Zn available for spermatozoan uptake) was lower in asthenozoospermic patients and it was also directly related to sperm motility in all the pooled subjects. These data suggest that altered sperm motility is associated with a probable impairment of sex accessory gland function in subjects with idiopathic asthenozoospermia, while prostatic acid phosphatase seems mainly related to sperm motility.

Determinación de zinc y cobre en leche materna en una muestra de población de Caracas / Determination of zinc and copper in maternal milk in a sample from Caracas population

La importancia de los oligoelementos en el período perinatal ha sido extensamente estudiada en la última década. En la actualidad los datos son muy distintos, lo cual probablemente sea debido a diferencias de orden geográfico, racial, nutricional, etc. De allí la importancia de conocer los valores de cada zona para ir determinando mejor los factores que pueden contribuir a esas diferencias. Se estudiaron 72 gestantes del Hospital Miguel Pérez Carreño de Caracas que tuvieron su parto entre abril y diciembre de 1989. Se les realizó una ficha personal y se tomaron muestras de leche materna, los días 3,7 y 21 del postparto. Se determinaron concentraciones de zinc (Zn) y de cobre (Cu) por el método de espectrofotometría atómica con un espectrofotómetro VARIAN modelo AA-875. La población materna estudiada resultó una muestra homogénea correspondiente a los estratos III-IV-V de Graffar modificado por Méndez. El valor promedio de la concentración de Zn en la leche materna en el 3er. día fue de 650,00 ñ 240,31 ug/dl y la de Cu fue de 57,28 ñ 27,97 ug/dl. El valor promedio de la concentración de Zn en leche materna en el 7mo.día fue de 346,91 ñ 90,14 ug/dl y la de Cu fue de 53,61 ñ 16,15 ug/dl. El valor promedio de la concentración de Zn en leche materna del día 21 fue de 255,35 ñ 90,32 ug/dl y la del Cu fue de 52,24 ñ10,55 ug/dl. Los resultados de este trabajo son la proyección de una muestra normal de embarazadas y recién nacidos, provenientes de una población de estrato socieconoómico medio bajo de la ciudad de Caracas, que goza de un salario fijo y de los beneficios del Seguro Social y que presentó un comportamiento homogéneo, sin déficit de Zn y Cu, lo que pudiera representar los valores normales para utilizarlos como referencia, al estudiar sujetos con características similares a la estudiada

Two brothers with a variant of hereditary sensory neuropathy.

We report two brothers with the clinical symptoms and neuropathological findings of hereditary sensory and autonomic neuropathy (HSAN) type IV but with normal sweating function and absence of recurrent fever. We propose that our patients may have a lower degree of expression of the genetic defect underlying HSAN type IV or that they represent a separate genetic entity.

Molecular basis of an adult form of beta-hexosaminidase B deficiency with motor neuron disease.

A patient (KL) with progressive motor neuron disease associated with partial Hex A (alpha beta) and no Hex B (beta beta) activity, synthesized beta-chains which only associated with alpha-chains. To identify the molecular basis of this inability of beta-chains to self associate, RNA from cultured fibroblasts was reverse transcribed, the cDNA encoding the beta-chain amplified by polymerase chain reaction, subcloned, and sequenced to reveal two types of single missense mutation. The first mutation, (Type I) 619A----G, was paternally inherited and converted a 207IIe----Val in a highly conserved region believed to be associated with catalytic activity and activator protein binding. Biochemical evidence for impaired activator protein binding was obtained by purifying Hex A from KL urine and demonstrating a greater than 50% reduction of in vitro GM2 hydrolysis compared to normal urinary Hex A. In other cDNA species (Type II), a maternally inherited 1367A----C mutation converted 456Tyr----Ser in another highly conserved region of the beta-chain and we propose that this mutation leads to the inability of the beta-chains to self associate and thus reach maturity. These same cDNA species contained a second 362A----G mutation which converted 121Lys----Arg, but is apparently a polymorphism since it also occurs in some normal subjects. We propose that the patient is a compound heterozygote in which a combination of no self-association of the mutant beta-chains and impaired activator protein binding to alpha-beta (mutant) (Hex A) required for GM2 hydrolysis result in total beta-Hex B deficiency and slow accumulation of GM2 ganglioside, primarily in motor neurons.