Investigating the role of the experimental protocol in phenylhydrazine-induced anemia on mice recovery.

Production of red blood cells involves growth-factor mediated regulation of erythroid progenitor apoptosis and self-renewal. During severe anemia, characterized by a strong fall of the hematocrit followed by a recovery phase, these controls allow a fast recovery of the hematocrit and survival of the organism. Using a mathematical model of stress erythropoiesis and an ad hoc numerical method, we investigate the respective roles of anemia-inducing phenylhydrazine injections and physiological regulation on the organism's recovery. By explicitly modeling the experimental protocol, we show that it mostly characterizes the fall of the hematocrit following the anemia and its severeness, while physiological process regulation mainly controls the recovery. We confront our model and our conclusions to similar experiments inducing anemia and show the model's ability to reproduce several protocols of phenylhydrazine-induced anemia. In particular, we establish a link between phenylhydrazine effect and the severeness of the anemia.

Hiperplasia estromal pseudoangiomatosa de la mama (HEPA): estudio clínico, radiológico y patológico de 4 casos / Pseudoangiomatous stromal hyperplasia of the breast: a clinical, radiologic and pathological study of 4 cases

Generalmente afecta a mujeres en edad reproductiva, aunque se ha descrito en pacientes entre 12 y 75 años. Suele presentarse como un hallazgo incidental en el estudio histológico tras cirugía por patología benigna o maligna, aunque ocasionalmente su presentación clínica es como una tumoración mamaria indolora, simulando un fibroadenoma. La biopsia percutánea ecoguiada permite detectar la naturaleza de la lesión y descartar patología maligna, como el angiosarcoma de bajo grado. La hiperplasia estromal pseudoangiomatosa (HEPA) es una lesión mamaria poco frecuente, de carácter benigno. Se caracteriza por un sobrecrecimiento benigno de tejido conectivo fibroso que produce numerosos espacios que semejan estructuras vasculares. Se describe una serie de cuatro casos con diferente presentación clínica. Los dos primeros se manifestaron como una tumoración mamaria palpable, única e indolora, el tercero fue un hallazgo histopatológico en la pieza quirúrgica de una cuadrantectomía, realizada como tratamiento de un carcinoma intraductal mamario y el cuarto caso fue en un varón diagnosticado de ginecomastia unilateral (AU)

Pseudoangiomatous stromal hyperplasia (PASH) is a rare benign breast lesion, characterized by a benign overgrowth of fibrous connective tissue of the breast, which produces numerous spaces resembling vascular structures. This entity most commonly affects premenopausal women but cases have been described at all ages ranging from 12 to 75 years. PASH is usually an incidental histological finding after surgery for benign or malignant tumors but may also present as a mass or painless nodule mimicking fibroadenoma. Ultrasound-guided percutaneous biopsy allows the type of lesion to be determined and malignancies, such as low grade angiosarcoma, to be excluded. We report four new cases of PASH with distinct clinical presentations. The first two cases presented as a single painless breast mass, the third as anincidental finding in the surgical specimen from a quadrantectomy performed for an intraductal breast carcinoma, and the fourth case occurred in a man with unilateral gynecomastia (AU)

[Study of neurovascular contact in essential hemifacial spasm: an example of CISS sequence and magnetic resonance angiography]. / Estudio por resonancia magnética del contacto neurovascular en el espasmo hemifacial esencial: empleo de secuencia CISS y angiografía por resonancia magnética.

BACKGROUND AND PURPOSE: The purpose of this article is to assess the validity of the magnetic resonance imaging (MRI) CISS 3D sequence associated with 3D time of flight (TOF) angiographic sequence in order to detect neurovascular contact (NVC) between the facial nerve and neighbouring arteries in patients with essential hemifacial spasm (HFS) and to determine the relationship between HFS symptoms and NVC and NVC image features (type, number and site). MATERIALS AND METHODS: We prospectively enrolled 120 cerebellopontine angle (CPA) MRI studies, 44 cases with HFS symptoms and 76 which were asymptomatic (controls), using axial T2-weighted (CISS) and axial 3D TOF series with associated Maximal intensity (MIP) reconstructions. Prior TOF angiographic studies were available for 56 cases without associated CISS images and the results obtained from that study were compared with the results of the current study. RESULTS: The diagnostic values obtained significantly favoured the protocol used in this study, which demonstrated a sensitivity of 77.27% and a specificity of 75%. There was a statistically significant relationship between the presence of NVC and HFS symptoms (p<0.0001). Only one statistically significant relationship was found between facial nerve displacement (in type of NVC) and HFS symptoms (p=0.019). CONCLUSIONS: The proposed MRI protocol is sensitive and valid for detecting NVC in patients with HFS. The results of our study support a relationship between NVC and HFS symptoms. It is not a simple relationship, however. It may be influenced by other factors, such as displacement of the facial nerve due to NVC.

Estudio por resonancia magnética del contacto neurovascular en el espasmo hemifacial esencial: empleo de secuencia CISS y angiografía por resonancia magnética / Study of neurovascular contact in essential hemifacial spasm: an example of CISS sequence and magnetic resonance angiography

Objetivos: Evaluar la validez de la secuencia CISS 3D de resonancia magnética (RM) en relación con secuencias angiográficas TOF 3D para la detección del contacto neurovascular (CNV) entre el nervio facial y las arterias vecinas en pacientes con espasmo hemifacial esencial (EHE) y determinar la asociación entre la presencia de síntomas de EHE y el CNV y las características de imagen del CNV (tipo, número y localización).Material y métodos: Se han estudiado prospectivamente 120 ángulos pontocerebelosos (APC), 44 con clínica de EHE y 76 asintomáticos (controles), mediante el empleo de una serie axial potenciada en T2 (CISS) y una serie axial con técnica angiográfica TOF 3D con reconstrucciones MIP; 56 de estos APC tenían un estudio angiográfico TOF previo y se compararon sus resultados con los del estudio actual.Resultados: Los valores diagnósticos obtenidos fueron significativos a favor del protocolo del presente trabajo que mostró una sensibilidad del 77,27% y una especificidad del 75%. Se demostró una asociación estadísticamente significativa entre la presencia de CNV y la clínica de EHE (p<0,0001). Entre las características del CNV estudiadas, únicamente se halló una asociación estadísticamente significativa entre el desplazamiento del nervio facial (dentro de tipo de CNV) y la clínica de EHE (p=0,019). Conclusiones: El protocolo de RM propuesto es sensible y válido para detectar CNV en pacientes con EHE. Los resultados de nuestro estudio apoyan la asociación entre el CNV y la clínica de EHE, si bien no se trata de una asociación simple, sino que puede estar influida por otros factores, como el desplazamiento del nervio facial producido por el CNV (AU)

Background and purpose: The purpose of this article is to assess the validity of the magnetic resonance imaging (MRI) CISS 3D sequence associated with 3D time of flight (TOF) angiographic sequence in order to detect neurovascular contact (NVC) between the facial nerve and neighbouring arteries in patients with essential hemifacial spasm (HFS) and to determine the relationship between HFS symptoms and NVC and NVC image features (type, number and site).Materials and methods: We prospectively enrolled 120 cerebellopontine angle (CPA) MRI studies, 44 cases with HFS symptoms and 76 which were asymptomatic (controls), using axial T2-weighted (CISS) and axial 3D TOF series with associated Maximal intensity (MIP) reconstructions. Prior TOF angiographic studies were available for 56 cases without associated CISS images and the results obtained from that study were compared with the results of the current study. Results: The diagnostic values obtained significantly favoured the protocol used in this study, which demonstrated a sensitivity of 77.27% and a specificity of 75%. There was a statistically significant relationship between the presence of NVC and HFS symptoms (p<0,0001). Only one statistically significant relationship was found between facial nerve displacement (in type of NVC) and HFS symptoms (p=0.019).Conclusions: The proposed MRI protocol is sensitive and valid for detecting NVC in patients with HFS. The results of our study support a relationship between NVC and HFS symptoms. It is not a simple relationship, however. It may be influenced by other factors, such as displacement of the facial nerve due to NVC (AU)

The first non-LTR retrotransposon characterised in the cephalochordate amphioxus, BfCR1, shows similarities to CR1-like elements.

BfCR1 is the first non-long terminal repeat retrotransposon to be characterised in the amphioxus genome. Sequence alignment of the predicted translation product reveals that BfCR1 belongs to the CR1-like retroposon class, a family widely distributed in vertebrate and invertebrate lineages. Structural analysis shows conservation of the specific motifs of the ORF2-CR1 elements: the N-terminal endonuclease, the reverse transcriptase and the C-terminal domains. The BfCR1 element possesses an atypical 3' terminus consisting of the tandem repeat (AAG)6. We gathered evidence supporting the mobility of this element and report an estimated 15 copies of BfCR1, mostly truncated, per haploid genome, a remarkably low number when compared to that of vertebrates. Phylogenetic analysis, including the amphioxus element, seems to indicate that (i) CR1-like retroposons cluster in a monophyletic group and (ii) the CR1-like family was already present in the chordate ancestor. Our data provide further support for the horizontal transmission of CR1-like elements during early vertebrate evolution.

Numerical integration of autonomous and non-autonomous non-linear size-structured population models.

We present an efficiency study for autonomous and non-autonomous non-linear size-structured population models. The study considers three numerical methods: a characteristics scheme, the Lax-Wendroff method and the box method, which are completely described in the paper. Five test problems are considered with diverse degree of complexity: non-trivial equilibrium, periodic solutions and diverse growth functions. The study of the efficiency takes into account the properties of the numerical schemes (such as the stability) and uses a multiple regression analysis to determine the constants of the leading terms of the corresponding global errors. We show how the tables of errors and cpu-times can be used to explain the meaning of the efficiency results. In addition, we present the convergence analysis of the box method.

Characterization of alternatively spliced products and tissue-specific isoforms of USP28 and USP25.

BACKGROUND: The ubiquitin-dependent protein degradation pathway is essential for the proteolysis of intracellular proteins and peptides. Deubiquitinating enzymes constitute a complex protein family involved in a multitude of cellular processes. The ubiquitin-specific proteases (UBP) are a group of enzymes whose predicted function is to reverse the ubiquitinating reaction by removing ubiquitin from a large variety of substrates. We have lately reported the characterization of human USP25, a specific-ubiquitin protease gene at 21q11.2, with a specific pattern of expression in murine fetal brains and adult testis. RESULTS: Database homology searches at the DNA and protein levels and cDNA library screenings led to the identification of a new UBP member in the human genome, named USP28, at 11q23. This novel gene showed preferential expression in heart and muscle. Moreover, cDNA, expressed sequence tag and RT-PCR analyses provided evidence for alternatively spliced products and tissue-specific isoforms. Concerning function, USP25 overexpression in Down syndrome fetal brains was shown by real-time PCR. CONCLUSIONS: On the basis of the genomic and protein sequence as well as the functional data, USP28 and USP25 establish a new subfamily of deubiquitinating enzymes. Both genes have alternatively spliced exons that could generate protein isoforms with distinct tissue-specific activity. The overexpression of USP25 in Down syndrome fetal brains supports the gene-dosage effects suggested for other UBP members related to aneuploidy syndromes.

Numerical schemes for size-structured population equations.

We formulate schemes for the numerical solution of size-dependent population models. Such schemes discretize size by means of a natural grid, which introduces a discrete dynamics. The schemes are analysed and optimal rates of convergence are derived. Some numerical experiments are also reported to demonstrate the predicted accuracy of the schemes.

USP25, a novel gene encoding a deubiquitinating enzyme, is located in the gene-poor region 21q11.2.

We have identified a new gene, USP25, spanning over 150 kb at 21q11. 2, one of the lowest gene-density regions of the human genome. USP25 is made up of 25 exons and encodes a 1087-aa protein. Database comparisons reveal high homology with members of the ubiquitin protease family (UBP). Basal expression was observed in all human tissues tested, and two main transcripts were identified. The homologous murine gene has also been characterized. In situ hybridization in mouse embryonic brains showed a clear correlation of expression with proliferative neuroepithelial cells and postmitotic neurons. Moreover, high expression was observed in adult mouse testis. UBPs belong to a complex family of deubiquitinating enzymes that specifically cleave ubiquitin conjugates on a great variety of substrates. These enzymes have an essential role in protein degradation via the 26S proteasome and thus regulate many cellular pathways. An increase in USP25 gene dosage in Down syndrome patients could seriously disturb the balance between ubiquitinated and deubiquitinated substrates.

Effect of dried solids of nejayote on broiler growth.

The purpose of the present study was to test the suitability of the solids of nejayote (a waste product from the tortilla industry) in diets for broilers. The nejayote was obtained from two different tortilla-making factories and the solids were obtained by centrifuge then dried in a hot-air drier. Diets were formulated to be isocaloric and isonitrogenous according to the NRC dietary requirements (1994). Nejayote solids were supplemented at 2, 4, and 6% of the diet. Results show that the content of protein and calcium in the dried solids of nejayote were 5 and 13%, respectively. The performance of broilers fed diets supplemented with dried nejayote did not differ from that of those fed the control diet. Therefore, it is concluded that nejayote solids are suitable for broiler feed and do not affect growth performance. Utilization of nejayote solids at higher levels is a possibility provided that no adverse effects on body weight, feed utilization, and feed:gain ratios are observed.

Effect of n-3 polyunsaturated fatty acids on the lipidic profile of healthy Mexican volunteers.

OBJECTIVE: The effect of n-3 polyunsaturated fatty acids on the serum lipid profile in a Mexican population was evaluated. MATERIAL AND METHODS: Three g of salmon oil was the daily intake during four weeks. Total cholesterol, triglycerides, low density lipoproteins, high density lipoproteins and erythrocyte fatty acid composition were analyzed. RESULTS: The hypertriglyceridemic group showed a statistically significant (p < 0.05) reduction of triglycerides and significant (p < 0.01) elevation of high density lipoproteins. The hypercholesterolemic group reduced significantly the levels of cholesterol and triglycerides; high density lipoproteins were augmented by 11.6%. CONCLUSIONS: The hypolipidemic effect of n-3 polyunsaturated fatty acids was manifest in the Mexican volunteers under the conditions here evaluated.

Polyunsaturated fatty acid deficiencies: effects on hepatic plasma membrane fatty acid composition and enzyme activity.

Research on dietary polyunsaturated fatty acids (PUFA), on the activity of 5'nucleotidase and adenylate cyclase are largely contradictory due, mostly, to the absence of adequate control group. In this study; four different diets have been evaluated on the 5'nucleotidase and adenylate cyclase activities in rat liver plasma membranes. Wistar rats were given a semisynthetic diet in which lipids were supplied by 5% of either peanut oil (n-3 PUFA deficient diet), cod liver oil (n-6 PUFA deficient diet) partially hydrogenated palm oil (total PUFA deficient diet) and a mixture of peanut and rapeseed oil (control group). Liver plasma membranes were separated by using a Percoll gradient in a Beckman JA 20 centrifuge. 5'nucleotidase and adenylate cyclase activities were measured in a liquid scintilation detector by following the degradation of 3HAMP (adenosine monophosphate) and production of 3HcAMP (cyclic adenosine monophosphate) respectively. Animals fed the total PUFA deficient diet exhibited significant lower body weight and lower liver weight than did the control group. Low cholesterol concentrations were observed in animals deficient either in n-3 or total PUFA in relation to the control group. All dietary deficiencies studies provoked reduced phospholipid levels. Phosphatidylcholine and phosphatidylethanolamine were not modified whatever the deficiency studied. Phospholipids fatty acid composition was significantly modified by the diets studied. The specific activity of 5'nucleotidase in hepatic plasma membrane was independent of dietary PUFA. The catalytic unit of adenylate cyclase complex in totally deficient animals was augmented. The unit of the enzyme stimulated by the guanydyl imidodiphosphate (GppNHp) in n-3 PUFA deficient animals was augmented and reduced in animals receiving the n-6 PUFA deficient diet. In conclusion, our results show that each dietary PUFA deficiency modifies differently the proportions of phospholipid classes and their fatty acid composition. The mechanisms responsible for these modification remain to be elucidated. However, the phospholipid fatty acid changes did not influence the 5'nucleotidase activity except in the case of extreme excess which concerns more toxicology than nutritional modifications. Finally, the catalytic unit (Forskoline + GDP beta s) of adenylate cyclase complex and the regulatory unit (GppNHp) may be sensitive to alterations in PUFA composition.

[Prevention of cholera transmission: rapid evaluation of the quality of municipal water in Trujillo, Peru]. / Prevención de la transmisión del cólera: evaluación rápida de la calidad del agua municipal en Trujillo, Perú.

Unboiled, unchlorinated drinking water is known to have been associated with epidemic transmission of cholera in Trujillo, Peru, in February 1991. In September of that same year, chlorination of the main water supply system was begun. Water quality in Trujillo at the central level is monitored at dams and principal distribution points, but the effects of this surveillance on the quality of the water distributed are not known. In order to evaluate water quality in the residential areas of Trujillo, water samples were collected in February 1993 from 30 systematically selected houses. The chlorine levels in the samples were measured, and cultures for coliform bacteria were done. The free chlorine concentration varied from 0 to 1.5 mg/L (median = 0.4 mg/L). No free chlorine was detected in 5 samples (17%), and in 14 (47%) the concentrations were less than 0.4 mg/L. Coliforms were found in 16 samples (53%), but none were fecal coliforms. These results demonstrate the wide variability in chlorine concentrations in the municipal water that is distributed to dwellings. This variability, together with the need to store drinking water in the house because of shortages, supports the recommendation of the Ministry of Health that residents should treat drinking water in their homes. The simple sampling framework employed in this study provided a rapid evaluation of the quality of municipal water supplied to consumers. Similar studies could be carried out easily in other metropolitan areas where water quality is suspect, in order to rapidly obtain essential information on water quality at the level of the consumer.

Complicación pulmonar por tratamiento con droga anticoagulante: presentación de un caso; revisión bibliográfica / Intrapulmonary hemorrhagic complication with anticoagulant treatment: report of a case; bibliographic review

Se presentan los resultados bacteriológicos obtenidos en examen de 759 catéteres colocados a 500 pacientes quirúrgicos con el fin de administrar nutrición parenteral. Se encontró que a pesar de que 318 pacientes tenían un foco séptico, sólo en 10 (1,3%) se puede explicar la sepsis como punto de partida del cateter. Con técnica de colocación y cuidados rigurosos de asepsia, se puede obtener la incidencia baja de sepsis por cateter