Conservación de cepas bacterianas por congelación sobre discos de celulosa

The conservation of bacterial strains adscribed to different genus and species, by freezing at -300ºC using disc paper of cellulose have been studied. It has also tested wether this technique can be utilized for maintenance of rnicroorganisms with structural and physiologic differences. The results show how the freezing of bacterial cultures on cellulose disc paper, keep the bacterial viability in good conditions. This technique is a good way of mainteneance of bacterial strains. It is significative that for recuperation of non halophiles strains, no enrichment medium is required.Se estudia la conservación de cepas bacterianas pertenecientes a diferentes géneros y especies, por congelación a 300C utilizando como soporte discos de papel de celulosa. Asímismo se compruebe si esta técnica puede ser utilizada para la conservación de bacterias estructural y fisiologicamente diferentes entre sí o si por el contrario no es aconsejable para determinados tipos bacterianos. Los resultados obtenidos, muestran que la congelación de suspensiones bacterianas sobre discos de celulosa, mantiene la viabilidad en condiciones suficientemente satisfactorias para considerar que esta técnica es un procedimiento eficaz de conservación de cepas bacterianas. Debe resaltarse el hecho de que la recuperación de las cepas no halófilas, tanto de Colección como de muestras clínicas, no requiere, en la mayoría de los casos de medios de enriquecimiento

Conservación de cepas bacterianas por congelación sobre discos de celulosa

Se estudia la conservación de cepas bacterianas pertenecientes a diferentes géneros y especies, por congelación a 300C utilizando como soporte discos de papel de celulosa. Asímismo se compruebe si esta técnica puede ser utilizada para la conservación de bacterias estructural y fisiologicamente diferentes entre sí o si por el contrario no es aconsejable para determinados tipos bacterianos. Los resultados obtenidos, muestran que la congelación de suspensiones bacterianas sobre discos de celulosa, mantiene la viabilidad en condiciones suficientemente satisfactorias para considerar que esta técnica es un procedimiento eficaz de conservación de cepas bacterianas. Debe resaltarse el hecho de que la recuperación de las cepas no halófilas, tanto de Colección como de muestras clínicas, no requiere, en la mayoría de los casos de medios de enriquecimiento.The conservation of bacterial strains adscribed to different genus and species, by freezing at - 300C using disc paper of cellulose have been studied. It has also tested wether this technique can be utilized for maintenance of rnicroorganisms with structural and physiologic differences. The results show how the freezing of bacterial cultures on cellulose disc pa per, keep the bacterial viability in good conditions. This technique is a good way of mainteneance of bacterial strains. It is significative that for recuperation of non halophiles strains, no enrichment medium is required

Adherencia bacteriana a linfocitos humanos y murinos

We have studied the capacity for a selective adherence to different human and murine lymphoid subpopulation of bacterial strains belonging to different genera and species. The strains of the genus Bacillus normally have a great capacity to bind to the murine lumphoid surfaces. Other strains with interesting adherence properties are Staphylococcus epidermidis, S. aurcus, Yersinia enterocolitica and Sporosarcina halophila. In the assay of adherence to human lumphocytes only Y. enterocolitica and S. halophila show binding capacity although in any one of cases in selective way.Hemos estudiado la capacidad de adherencia selectiva a distintas subpoblaciones linfocitarias humanas y murinas de diferentes cepas bacterianas pertenecientes a distintos géneros y especies. Las cepas pertenecientes al género Bacillus tienen, en general gran capacidad de unión a la superficie linfocitaria murina. Otras especies que presentan interesantes propiedades de adherencia son: Staphylococcus epidermidis, S. aurcus, Yersinia enterocolitica y Sporosarcina halophila. En el ensayo de adherencia a linfocitos humanos solo Y. enterocolitica y S. halophila se unen a ellos, aunque en ninguno de los casos de forma selectiva

Optimization of Amino Acid Sequence of Fmoc-Dipeptides for Interaction with Lipid Membranes

Fmoc-dipeptides appear as highly relevant building blocks in smart hydrogels and nanovehicles for biological applications. The interactions of the Fmocdipeptides with the cell membrane determine the efficiency of the nanomaterials based on the Fmoc-dipeptides’ internalization of nanovehicles for drug delivery. Here, we aim to understand the interplay of the interactions between the Fmoc-dipeptides and a phospholipid surface as a function of the amino acid sequence. The DMPA (1,2-dimyristoyl-snglycero- 3-phosphate) phospholipid in Langmuir monolayers was used as a model cell surface. A set of seven derivatives of Fmoc-dipeptides with a broad range of hydrophobicity were included. Mixed monolayers composed of DMPA/Fmoc-dipeptides in an equimolar ratio were built and characterized in situ at the air/water interface. Surface pressure−molecular area isotherms (π−A), Brewster angle microscopy (BAM), and UV−vis reflection spectroscopy (ΔR) were combined to provide a holistic picture of the interactions of the Fmoc-dipeptide with the phospholipid molecules. An increase in the hydrophobicity led to enhanced interaction of the Fmoc-dipeptide and DMPA molecules. The compression of the mixed monolayer could displace a significant fraction of the Fmoc-dipeptide from the monolayer. High hydrophobicity promoted self-assembly of the Fmoc-dipeptides over interaction with the phospholipid surface. The interplay of these two phenomena was analyzed as a function of the amino acid sequence of the Fmoc-dipeptides. The toxicity effect of Fmoc-FF could be observed and detailed at the molecular level. This study suggests that the adjustment of the hydrophobicity of the Fmoc-dipeptides within a defined range might optimize their efficiency for interaction with the lipid membranes. A semiquantitative guide for the chemical design of Fmoc-dipeptides for biological applications is proposed herein

Time-related efficacy of liver cell isografts in fulminant hepatic failure

We and others have reported that dispersed liver cells transplanted into the spleen parenchyma of syngeneic rats remained functional and viable for a long time. This report describes our results with hepatocellular transplantation as a therapeutic method in a model of fulminant hepatic failure (FHF) in the rat. 60 male Sprague-Dawley rats weighing 200-250 g were used. The FHF was reached through an Eck's fistula with 2/3 hepatectomy at the same time. This model produced lethal hepatic failure in a highly reproducible manner. Liver cells were isolated by the collagenase method. 40 X 10(6) hepatocytes suspended in Hanks' balanced salt solution were transplanted into the spleen parenchyma 24 hr before (group 1), at the same time as (group 2), and 24 hr after (group 3) FHF was achieved. Additional sham-operated animals (groups 4 and 5) and a control group (group 6) were used. The hepatocellular transplantation markedly increased the survival of the animals with induced FHF to 80% (group 1) and 60% (group 2)--but not in group 3 (20%),--compared with 10% in the control group. This study shows that dispersed liver cells transplanted into the spleen can provide sufficient support to allow animals with lethal hepatic failure to survive and recover. Nevertheless the efficacy of transplantation is a time-related phenomenon with the FHF induction

Unravelling the 2D self-assembly of Fmoc-dipeptides at fluid interfaces

Dipeptides self-assemble into supramolecular structures showing plenty of applications in the nanotechnology and biomedical fields. A set of Fmoc-dipeptides with different aminoacid sequences has been synthesized and their self-assembly at fluid interfaces has been assessed. The relevant molecular parameters for achieving an efficient 2D self-assembly process have been established. The selfassembled nanostructures of Fmoc-dipeptides displayed significant chirality and retained the chemical functionality of the aminoacids. The impact of the sequence on the final supramolecular structure has been evaluated in detail using in situ characterization techniques at air/water interfaces. This study provides a general route for the 2D self-assembly of Fmoc-dipeptides

Advances of hyaluronic acid in stem cell therapy and tissue engineering, including current clinical trials

yaluronic acid (HA), as one of the main components of the extracellular matrix (ECM), plays a significant role in a multitude of biological processes involving cell migration, proliferation, differentiation, wound healing and inflammation. Thanks to its excellent biocompatibility, biodegradability and hygroscopic properties, HA has been used in its natural form for joint lubrication and ocular treatment. The chemical structure of HA can be easily modified by direct reaction with its carboxyl and hydroxyl groups. Recently, HA derivatives have been synthesised with the aim of developing HA-based materials with increased mechanical strength, improved cell interactions and reduced biodegradation and studied for regenerative medicine purposes, including cell therapy and tissue engineering. In this context, the present manuscript reviews HA applications from a basic point of view – including chemical modifications and cellular biology aspects related to clinical translation – and future perspectives of using biofabrication technologies for regenerative medicine. A detailed description of current clinical trials, testing advanced therapies based on combination of stem cells and HA formulations, is included. The final goal was to offer an integral portrait and a deeper comprehension of the current applications of HA from bench to bedside

Cirugía derivativa más radioterapia intraoperatoria y externa en el carcinoma de páncreas localizado e irresecable

Presentamos una serie de 25 casos de carcinomas de páncreas localmente avanzados e irresecables, sin metástasis a distancia, tratados con cirugía derivativa, radioterapia intraoperatoria e irradiación externa: 18 tumores de cabeza (16 con ictericia obstructiva) y 7 de cuerpo. Se realizó derivación biliar en 18 y gastroyeyunostomía en 19. La mortalidad operatoria fue nula, con una morbilidad del 16%. A largo plazo se produjeron 3 hemorragias digestivas, 2 ictericias obstructivas, una colangitis y una obstrucción intestinal. Se obtuvo un 72% de control local de la enfermedad y todos los fallecidos por progresión tumoral desarrollaron metástasis hepáticas y/o peritoneales. Presentaban dolor pancreático 22 pacientes y 20 experimentaron remisión del mismo en una a 2 semanas. La analgesia fue definitiva en 12 y reapareció el dolor tardíamente en ocho. La supervivencia media fue de 9 meses (rango 4-24). La revisión de la literatura pone de manifiesto la indicación de la radioterapia externa tanto en el carcinoma de páncreas irresecable y no metastásico como en los resecados. La asociación de radioterapia intraoperatoria tiene, así mismo, un papel importante en cuanto a supervivencia, paliación del dolor y de la progresión local. El 5-fluorouracilo asociado al tratamiento radioterápico prolonga significativamente la supervivencia con una morbilidad razonable

Involvement of leptin in the association between percentage of body fat and cardiovascular risk factors

OBJECTIVES: Recent epidemiologic studies have shown that obesity is associated with elevated blood concentrations of prothrombotic-proinflammatory factors and markers of endothelial dysfunction such as fibrinogen, C-reactive protein (CRP), von Willebrand factor (vWF), and homocysteine. We have assessed whether these markers are associated with percentage of body fat (BF), insulin sensitivity as well as with leptin concentrations. DESIGN AND METHODS: Twenty-five men aged 49.6 +/- 12.7 yr (mean +/- SD) underwent whole-body air displacement plethysmography (Bod-Pod(R)) for estimating BF. Blood analyses for leptin and several other metabolic and cardiovascular markers were carried out. RESULTS: Obese subjects had higher levels as compared to controls of BF (37.5 +/- 5.1 vs. 26.0 +/- 6.6, p < 0.01), fibrinogen (3.30 +/- 0.43 vs. 2.67 +/- 0.11, p < 0.01), vWF (136.4 +/- 50.4% vs. 81.6 +/- 12.6%, p < 0.05), and leptin (17.6 +/- 8.7 vs. 6.2 +/- 3.3, p < 0.01), lower concentrations of HDL-cholesterol (1.09 +/- 0.20 vs. 1.51 +/- 0.10, p < 0.001) and lower QUICKI (1/[log(Ins(0)) + log(Glu(0))]) (0.31 +/- 0.03 vs. 0.34 +/- 0.02, p < 0.05). No significant changes were observed in CRP (5.7 +/- 3.4 vs. 3.8 +/- 1.6, p = 0.327) and homocysteine (9.4 +/- 4.2 vs. 8.3 +/- 0.9, p = 0.749). A positive correlation was observed between BF and fibrinogen (r = 0.67, p = 0.0003). Plasma leptin concentrations were correlated with fibrinogen (r = 0.71, p = 0.0001) and CRP (r = 0.43, p = 0.044). After adjustment for BF leptin emerged as a significant predictor of fibrinogen (beta = 0.47, p = 0.023; R(2) = 0.59, p < 0.001). QUICKI was positively correlated with HDL-cholesterol (r = 0.59, p = 0.010) and negatively with fibrinogen (r = -0.53, p = 0.025), CRP (r = -0.52, p = 0.028) and vWF (r = -0.56, p = 0.013). CONCLUSIONS: Increased BF and impaired insulin sensitivity are associated with increased concentrations of cardiovascular risk factors. Leptin seems to be involved in this elevation and emerges as a predictor of circulating fibrinogen concentrations

Cáncer de esófago (I): Valoración epidemiológica, clínica y diagnóstica según el tipo histológico

From 1975 to 1991, sixty-eight patients were treated with surgery for esophageal cancer at the Clinica Universitaria de Navarra. This study involves an analysis of epidemiologic and predisposing risk factors in relation with the histologic type of tumor: epidermoid carcinoma vs. adenocarcinoma. The difference in mean age of males (60,5 yrs.) as compared with that of females (48,7 yrs.) was statistically significant (p < 0,05). Likewise, the mean age of patients with epidermoid carcinoma (57,8 yrs.) was significant lower (p < 0,01) as compared with that of those with adenocarcinoma (66,3 yrs.). Smoking and alcoholism were common in the group of patients with epidermoid carcinoma, while Barrett's esophagus and hiatal hernia were frequently seen in patients with adenocarcinoma. Dysphagia was the most frequent symptom both at the start of disease (75%) and with the diagnosis established (96,7%). There was no significant difference in the symptomatology of patients with one type of tumor or the other. The efficacy of ancillary diagnostic procedures such as barium swallow, esophagoscopy, computerized tomography and biopsy were likewise assessed. The most frequent site of tumor was at the middle third, with majority of patients being at clinical stage 1-2 of disease at the time of diagnosi