El folículo piloso: una importante fuente celular en ingeniería tisular / Hair follicle: an important cellular source in tissue engineering

El folículo piloso-sebáceo o unidad folículo-sebácea-apócrina es un órgano microscópico complejo funcional y estructuralmente. Consta de un segmento superior, estable y un segmento inferior, que se regenera en cada ciclo piloso. El folículo piloso contiene una gran diversidad de tipos celulares, entre los que se encuentran células madre. De hecho, supone el nicho más importante de células madre en la piel, con la ventaja añadida de su fácil accesibilidad. Estas células madre se localizan en una prominencia a nivel de la inserción del músculo erector del pelo, llamada "bulge" (promontorio). Son las encargadas de regenerar el folículo en cada ciclo y también intervienen en la reconstitución de las glándulas sebáceas y de la epidermis interfolicular, en caso de lesión epidérmica. El conocimiento de la estructura del folículo piloso, está haciendo posible cada vez más el empleo de los distintos tipos celulares, especialmente, las células madre, en la ingeniería tisular de la piel. Asimismo, estudios recientes han diferenciado las células madres foliculares a diferentes estirpes, como por ejemplo: células nerviosas, hematopoyéticas y vasculares. Además, se ha estudiado la construcción de folículos pilosos, con resultados satisfactorios en ratones, aunque no del todo superponibles a humanos, en los que se precisan más investigaciones. La posibilidad de generar folículos pilosos humanos, supondría una revolución en el amplio campo de las alopecias. El objetivo de esta revisión es describir la estructura anatómica e histológica del folículo piloso, enfatizando en la importancia del mismo como nicho de células madre y su potencial utilidad en el campo de la ingeniería tisular, para la construcción de diversos tipos de tejidos.(AU)

The hair follicle is a microscopic organ, functionally and structurally complex. It can be divided into two distinct segments, the upper portion, stable and the lower portion, that undergoes regeneration every hair cycle. The hair follicle contains a variety of cells types, including stem cells. It fact, it is the most important niche of stem cells in the skin, with the added advantage of its easy accessibility. These stem cells are located in a prominence at the level of the insertion of the arrector pili muscle, called bulge. They are responsible of hair follicle regeneration each hair cycle, and also can form sebaceous glands and help in repopulation of the interfollicular epidermis after injury. The knowledge of hair follicle structure is making possible the use of different types of cells, especially stem cells, in skin tissue engineering. Furthermore, recent studies have differentiated follicle stem cells into different strains, for example: nervous, hematopoietic and vascular cells. Moreover, other late studies have focused on the hair follicle construction, with satisfactory results in mice, but not completely transferable to humans, which further research is needed. The possibility of human hair follicle regeneration would suppose a revolution in the broad world of alopecia. The aim of this review is to describe the anatomical and histological structure of the hair follicle, emphasizing the importance as stem cell niche, and its potential usefulness in the field of tissue engineering for the construction of various types of tissues.(AU)

El folículo piloso: una importante fuente celular en ingeniería tisular / Hair follicle: an important cellular source in tissue engineering

El folículo piloso-sebáceo o unidad folículo-sebácea-apócrina es un órgano microscópico complejo funcional y estructuralmente. Consta de un segmento superior, estable y un segmento inferior, que se regenera en cada ciclo piloso. El folículo piloso contiene una gran diversidad de tipos celulares, entre los que se encuentran células madre. De hecho, supone el nicho más importante de células madre en la piel, con la ventaja añadida de su fácil accesibilidad. Estas células madre se localizan en una prominencia a nivel de la inserción del músculo erector del pelo, llamada "bulge" (promontorio). Son las encargadas de regenerar el folículo en cada ciclo y también intervienen en la reconstitución de las glándulas sebáceas y de la epidermis interfolicular, en caso de lesión epidérmica. El conocimiento de la estructura del folículo piloso, está haciendo posible cada vez más el empleo de los distintos tipos celulares, especialmente, las células madre, en la ingeniería tisular de la piel. Asimismo, estudios recientes han diferenciado las células madres foliculares a diferentes estirpes, como por ejemplo: células nerviosas, hematopoyéticas y vasculares. Además, se ha estudiado la construcción de folículos pilosos, con resultados satisfactorios en ratones, aunque no del todo superponibles a humanos, en los que se precisan más investigaciones. La posibilidad de generar folículos pilosos humanos, supondría una revolución en el amplio campo de las alopecias. El objetivo de esta revisión es describir la estructura anatómica e histológica del folículo piloso, enfatizando en la importancia del mismo como nicho de células madre y su potencial utilidad en el campo de la ingeniería tisular, para la construcción de diversos tipos de tejidos.

The hair follicle is a microscopic organ, functionally and structurally complex. It can be divided into two distinct segments, the upper portion, stable and the lower portion, that undergoes regeneration every hair cycle. The hair follicle contains a variety of cells types, including stem cells. It fact, it is the most important niche of stem cells in the skin, with the added advantage of its easy accessibility. These stem cells are located in a prominence at the level of the insertion of the arrector pili muscle, called bulge. They are responsible of hair follicle regeneration each hair cycle, and also can form sebaceous glands and help in repopulation of the interfollicular epidermis after injury. The knowledge of hair follicle structure is making possible the use of different types of cells, especially stem cells, in skin tissue engineering. Furthermore, recent studies have differentiated follicle stem cells into different strains, for example: nervous, hematopoietic and vascular cells. Moreover, other late studies have focused on the hair follicle construction, with satisfactory results in mice, but not completely transferable to humans, which further research is needed. The possibility of human hair follicle regeneration would suppose a revolution in the broad world of alopecia. The aim of this review is to describe the anatomical and histological structure of the hair follicle, emphasizing the importance as stem cell niche, and its potential usefulness in the field of tissue engineering for the construction of various types of tissues.

Latitudinal and altitudinal growth patterns of brown trout Salmo trutta at different spatial scales.

Spatial variation in growth of stream-dwelling brown trout Salmo trutta was explored in 13 populations using a long-term study (1993-2004) in the Bay of Biscay drainage, northern Spain. The high variability in fork length (L(F)) of S. trutta in the study area was similar to the body-size range found in the entire European distribution of the species. Mean L(F) at age varied: 0+ years, 57.4-100.7 mm; 1+ years, 111.6-176.0 mm; 2+ years, 155.6-248.4 mm and 3+ years, 194.3-290.9 mm. Average L(F) at age was higher in main courses and lower reaches compared with small tributaries and upper reaches. Annual specific growth rates (G(L)) were: 0+ to 1+ years, 0.634-0.825 mm mm(-1) year(-1); 1+ to 2+ years, 0.243-0.342 mm mm(-1) year(-1); 2+ to 3+ years, 0.166-0.222 mm mm(-1) year(-1), showing a great homogeneity. Regression models showed that water temperature and altitude were the major determinants of L(F) at age variability within the study area. A broader spatial analysis using available data from stream-dwelling S. trutta populations throughout Europe indicated a negative relationship between latitude and L(F) of individuals and a negative interaction between latitude and altitude. These findings support previous evidence of the pervasive role of water temperature on the L(F) of this species. Altitude appeared as the overall factor that includes the local variation of other variables, such as water temperature or food availability. At a larger scale, latitude was the factor that encompassed these environmental gradients and explained the differences in L(F) of S. trutta. In summary, L(F) at age in stream-dwelling S. trutta decreases with latitude in Europe, the converse of Bergmann's rule.

Microsatellite markers for the drought-resistant earthworm Hormogaster elisae.

We developed and characterized 10 highly polymorphic microsatellite loci from a simple sequence repeat-enriched genomic DNA library of the earthworm Hormogaster elisae. Characterization of these loci using 26 individuals revealed eight to 25 alleles per locus and high levels of heterozygosity. These loci will be used for paternity analysis and population genetic studies.

Incidencia de la diabetes mellitus tipo 1 en la población de 0-14 años de edad, de la provincia de Jaén (1995-2000) / No disponible

Antecedentes. Los estudios de incidencia de diabetes tipo 1 son prioritarios para establecer tendencias y diferencias geográficas que ayuden a clarificar los factores ambientales que pueden intervenir. Y a un mejor conocimiento de la enfermedad. Objetivo. Conocer la incidencia de diabetes tipo 1, en la población de 0-14 años de edad, de la provincia de Jaén, durante el periodo 1995-2000. Pacientes y métodos. Diseño observacional, longitudinal y retropectivo. Los criterios de definición de casos fueron: criterios diagnósticos (normas del “NDDG” y “ADA”, edad de 0-14 años, y residencia de Jaén de forma habitual. La fuente de identificación fueron las historias clínicas de la red hospitalaria provincial. La población de rieso se estableció según datos y estimaciones censales. Se calculó la densidad de incidencia por años yla incidencia media para los seis años de estudio. Resultados. La incidencia media observada en Jaén es de 15.24 casos/105 niños-año; apreciándose, desde el año 1996 a 2000 una ligerísima tendencia a la disminución de las incidencias anuales (20,2 casos /105 niños a 12,1 casos/105). Se observó un ligero predominio de incidencia entre los varones, muy marcado en el grupo de 0-4 años de edad, donde el cociente de incidencias varón: mujer alcanza una cifra de cuatro. El grupo de edad de 5-9 años es el de mayor incidencia de diabetes, siendo llamativa la baja incidencia observada en niñas de 0-4 años de edad. Conclusiones. La incidencia de diabetes tipo 1 en Jaén en menor de la esperada y se observa una relativa estabilidad o ligero descenso en el peiodo de 1996-2000 (AU)

Introduction. The studies about incidence of diabetes mellitus type 1 (DM-1) are very important in order to establish geographical differences and to clarify the role of environment factors in the pathogenesis of the illness. Objedtive. Knowing the incidence of DM_1 in children younger than 14 years old in Jaén from 1995-2000. Patients and methods. We notice a slight tendency for annual incidence to go dow (from 20,2 cases/105 children to 12,1 cases/105). There was a slightly greater incidence in males than in females, specially in children 0 to 4 years of age. The highest incidence was observed among children 5 to 9 years of age and the lowest one in children diagnosed within the first year of live. Conclusions. The incidence of DM_1 in Jaén is lower than we expected and there is an very slight tendency to lower form 1996 to 2000 (AU)

Treatment of multidrug-resistant Acinetobacter baumannii ventilator-associated pneumonia (VAP) with intravenous colistin: a comparison with imipenem-susceptible VAP.

We prospectively evaluated the efficacy and toxicity of intravenously administered colistin in 35 episodes of ventilator-associated pneumonia (VAP) due to multidrug-resistant Acinetobacter baumannii. Microbiological diagnosis was performed with use of quantitative culture. In 21 patients, the episodes were caused by a strain susceptible exclusively to colistin (the CO group) and were all treated with this antimicrobial intravenously. In 14 patients, the episodes were caused by strains that remained susceptible to imipenem and were treated with imipenem-cilastatin (the IM group). Acute Physiology and Chronic Health Evaluation II scores at the time of admission and Sequential Organ Failure Assessment scores at time of diagnosis were similar in both groups. VAP was considered clinically cured in 57% of cases in both groups. In-hospital mortality rates were 61.9% in the CO group and 64.2% in the IM group, and the VAP-related mortality rates were 38% and 35.7%, respectively. Four patients in the CO group and 6 in the IM group developed renal failure. Neurophysiological evaluation was performed during 12 episodes in the CO group, but it revealed no signs of neuromuscular blockade. Intravenous colistin appears to be a safe and effective alternative to imipenem for the management of VAP due to carbapenem-resistant strains of A. baumannii.

Effects of three intravenous lipid emulsions on the survival and mononuclear phagocyte function of septic rats.

The immunosuppressive effects of intravenous lipid emulsions are a matter of great concern and debate. In a rat model of gram-negative bacteremia, we assessed whether the use of three intravenous lipid emulsions with different triacylglycerol compositions could influence mortality, bacterial clearance, and prostaglandin E(2) (PGE(2)) levels and compared these groups with groups of orally fed rats and rats that received a small amount of calories in form of glucose without enteral feeding (starvation). RATS WERE ASSIGNED TO ONE OF FIVE GROUPS: group 1 (control, n = 15) received rodent chow ad libitum and saline infusion; group 2 (starvation group, n = 12) had no access to chow and received an infusion of 5% glucose; group 3 (n = 17) received total parenteral nutrition (TPN) with long-chain triacylglycerols; group 4 (n = 12) received TPN with medium- and long-chain triacylglycerols; and group 5 (n = 15) received TPN with its emulsion based on olive oil. Animals received isonitrogenous and isocaloric TPN. After 2 d of TPN, a dose of 10(8) colony-forming units of Escherichia coli was introduced via the venous catheter; 2 d later the animals were killed. Blood, spleen, liver, and lungs were cultured. Circulating levels of PGE(2) were measured. Bacterial growth in the liver and lungs were significantly higher in groups 3 and 4 than in group 1, with no differences among the other groups. Rates of bacteremia were significantly higher in groups 3 and 4 than in group 1, with no differences among the other groups. Plasma levels of PGE(2) did not differ, and mortality was unaffected. Bacterial clearance clearly was preserved in orally fed, control rats when compared with rats on TPN with long-chain triacylglycerols or medium- plus long-chain triacylglycerols. However, the use of a lipid emulsion enriched intravenously with oleic acid was a valid way of reducing this disturbance, although plasma levels of PGE(2) and survival were not modified.

Clinical and metabolic effects of two lipid emulsions on the parenteral nutrition of septic patients.

OBJECTIVE: We compared the metabolic and clinical effects of two lipid emulsions, long-chain triacylglycerols (LCT) and a mixture of medium- and long-chain triacylglycerols (MCT/LCT), in septic patients. METHODS: Both groups received total parenteral nutrition (TPN) with a solution enriched with branched-chain amino acids (BCAA). Seventy-two septic patients received TPN with MCT/LCT (group 1) or LCT (group 2). Before starting TPN (basal) and 10 d after (final), various parameters were evaluated. RESULTS: Twenty-six subjects in each group completed the study. Both groups showed an increase in cholestasis enzymes, with no significant changes in lipid parameters. The rise of retinol-binding protein and the recovery of nitrogen balance were significantly greater in group 1. A multivariate analysis of nutritional markers and catabolic parameters showed a better evolution in group 1 (P = 0.002). The MCT/LCT group exhibited a significant increase of insulin levels. Overall mortality and length of stay in the intensive care unit were not affected by the lipid emulsion. CONCLUSIONS: In septic patients who received TPN with a solution enriched with BCAAs, the use of an emulsion containing MCT provided them with a greater recovery of their nutrition status than the traditional LCT formula, without influencing the outcome.

Evolution of the mitochondrial control region in Palaearctic brown trout (Salmo trutta) populations: the biogeographical role of the Iberian Peninsula.

In order to extend present knowledge of brown trout phylogeography in the Palaearctic, we analysed the complete mitochondrial D-loop sequence (1025-1027 bp) of all mitochondrial haplotypes of Salmo trutta found in the Iberian Peninsula and one North African haplotype. Sequence variation in the mitochondrial control region serves to identify four major haplotype groups within the Iberian Peninsula, i.e. Atlantic, Duero, Mediterranean and Andalusian. Including the Iberian haplotypes, the five main European groups previously established were increased to six: (i) an Atlantic group including two different clusters, South European and North Atlantic; (ii) a group representing an endemism restricted to the Duero basin in the Iberian Peninsula; (iii) an Adriatic-Andalusian group found in two vicariant areas including Adriatic-Ionian populations in the Mediterranean and the Andalusian basins of the southern Iberian Peninsula; (iv) a Mediterranean group with a distribution range that extends from the southwestern basins of the Iberian Peninsula to the Ionian basins of the Greek Peninsula; (v) a Danube group of wide distribution in the Black, Aral and Caspian basins; and (vi) a group comprising the S. t. marmoratus subspecies confined to the Adriatic Sea. The Iberian Peninsula appears to have acted as a physical boundary between haplotypes corresponding to Atlantic- and Mediterranean-draining rivers. Owing to its geographical position, this area has played a major role in present Palaearctic species distribution, as illustrated by its haplotype diversity.

Critical illness polyneuropathy: risk factors and clinical consequences. A cohort study in septic patients.

OBJECTIVE: To determine risk factors and clinical consequences of critical illness polyneuropathy (CIP) evaluated by the impact on duration of mechanical ventilation, length of stay and mortality. DESIGN: Inception cohort study. SETTING: Intensive care unit of a tertiary hospital. PATIENTS: Septic patients with multiple organ dysfunction syndrome requiring mechanical ventilation and without previous history of polyneuropathy. INTERVENTIONS: Patients underwent two scheduled electrophysiologic studies (EPS): on the 10th and 21st days after the onset of mechanical ventilation. RESULTS: Eighty-two patients were enrolled, although nine of them were not analyzed. Forty-six of the 73 patients presented CIP on the first EPS and 4 other subjects were diagnosed with CIP on the second evaluation. The APACHE II scores of patients with and without CIP were similar on admission and on the day of the first EPS. However, days of mechanical ventilation [32.3 (21.1) versus 18.5 (5.8); p=0.002], length of ICU and hospital stay in patients discharged alive from the ICU as well as in-hospital mortality were greater in patients with CIP (42/50, 84% versus 13/23, 56.5%; p=0.01). After multivariate analysis, independent risk factors were hyperosmolality [odds ratio (OR) 4.8; 95% confidence intervals (95% CI) 1.05-24.38; p=0.046], parenteral nutrition (OR 5.11; 95% CI 1.14-22.88; p=0.02), use of neuromuscular blocking agents (OR 16.32; 95% CI 1.34-199; p=0.0008) and neurologic failure (GCS below 10) (OR 24.02; 95% CI 3.68-156.7; p<0.001), while patients with renal replacement therapy had a lower risk for CIP development (OR 0.02; 95% CI 0.05-0.15; p<0.001). By multivariate analysis, CIP (OR 7.11; 95% CI 1.54-32.75; p<0.007), age over 60 years (OR 9.07; 95% CI 2.02-40.68; p<0.002) and the worst renal SOFA (OR 2.18; 95% CI 1.27-3.74; p<0.002) were independent predictors of in-hospital mortality. CONCLUSIONS: CIP is associated with increased duration of mechanical ventilation and in-hospital mortality. Hyperosmolality, parenteral nutrition, non-depolarizing neuromuscular blockers and neurologic failure can favor CIP development.

Risk factors for Acinetobacter baumannii nosocomial bacteremia in critically ill patients: a cohort study.

Nosocomial bacteremia caused by Acinetobacter baumannii (AB) is of increasing concern in critically ill patients, and the risk factors for this infection are not well established. An inception cohort study in a 40-bed medical and surgical intensive care unit (ICU) at a single institution was conducted during a 2-year period to determine the risk factors for AB nosocomial bacteremia. Risk factors related to the underlying diseases, the clinical picture at admission, and those acquired during the stay in the ICU were recorded upon admission and daily throughout the ICU stay. We defined an "invasive procedures index" as the number of invasive procedures performed every day during the ICU stay before the onset of AB bacteremia divided by the number of days in the ICU before the onset of AB bacteremia. Risk factors that were independently associated with AB bacteremia were immunosuppression, unscheduled admission to the hospital, respiratory failure at ICU admission, previous antimicrobial therapy, previous sepsis in the ICU, and the invasive procedures index.

Mitochondrial haplotype variation and phylogeography of Iberian brown trout populations.

The biogeographical distribution of brown trout mitochondrial DNA haplotypes throughout the Iberian Peninsula was established by polymerase chain reaction-restriction fragment polymorphism analysis. The study of 507 specimens from 58 localities representing eight widely separated Atlantic-slope (north and west Iberian coasts) and six Mediterranean drainage systems served to identify five main groups of mitochondrial haplotypes: (i) haplotypes corresponding to non-native, hatchery-reared brown trout that were widely distributed but also found in wild populations of northern Spain (Cantabrian slope); (ii) a widespread Atlantic haplotype group; (iii) a haplotype restricted to the Duero Basin; (iv) a haplotype shown by southern Iberian populations; and (v) a Mediterranean haplotype. The Iberian distribution of these haplotypes reflects both the current fishery management policy of introducing non-native brown trout, and Messinian palaeobiogeography. Our findings complement and extend previous allozyme studies on Iberian brown trout and improve present knowledge of glacial refugia and postglacial movement of brown trout lineages.

Occupational rhinitis and asthma caused by inhalation of Balfourodendron riedelianum (Pau Marfim) wood dust.

The case of a 30-year-old wood-worker, with rhinitis and asthma induced by exposure to the dust of Pau Marfim wood (Balfourodendron riedelianum) is reported. Hypersensitivity to this wood was confirmed by positive skin test, bronchial challenge test and RAST. The bronchial response was inhibited by sodium cromoglycate. Unexposed persons did not exhibit reactivity to this wood in any of the tests. When electrophoretic analysis of proteins in polyacrylamide gel was applied to a crude (phosphate-buffered) extract, an homogeneous distribution of low MW material was detected, with no clearly defined bands, suggesting the presence of filamentous type proteins. To the best of the author's knowledge, this is the first reported case of occupational rhinitis and asthma due to Pau Marfim wood dust. A type I (IgE-mediated) hypersensitivity mechanism was demonstrated but the non-glomerular nature of the proteins precluded further identification of the antigens involved.

Passive transfer of contact sensitivity to colophony as a complication of an allogenic bone-marrow transplant.

A 29-year-old woman developed allergic contact dermatitis from colophony 1 year after an allogenic bone-marrow transplant for refractory anaemia. The donor had a previous history of contact dermatitis from colophony, with a positive patch test. Although we cannot absolutely exclude active sensitization, it seems highly improbable because host immunity is severely restricted by the chemoradiotherapy used to prepare marrow graft recipients. The clinical data therefore suggest that sensitivity to colophony was passively acquired through marrow transplantation.

Normal pregnancy and delivery after cerebral metastases of choriocarcinoma: Case report.

Normal pregnancy and delivery after chemotherapy and radiation of cerebral metastases in a case of choriocarcinoma is presented. The need of surgical approach to these lesions as proposed by Stilp and his group is questioned.