An experimental study of the mouse skin behaviour: Damage and inelastic aspects

Samples of male and female mice skin were tested under monotonic and cyclic loading to mechanically characterize the tissue for large deformations. Cyclic tests have shown a typical Mullins effect widely known for elastomers and other soft tissues. No statistical difference was found in the maximum stretch of the sample after the fifth loading cycle for male (1.26 +/- 0.035) and female (1.18 +/- 0.083). However, larger dispersion was obtained for the maximum stress for both genders, 0.61 +/- 0.16 MPa for male and 0.78 +/- 0.32 MPa for female. Results show the presence of inelastic strain and stress softening in the skin at large deformations. They also have shown how stress softening and residual strain change with the magnitude of the applied load. Good correlation was observed between the residual strain and the maximum strain previously attained by the sample during loading for all samples. However, the correlation was different between genders.

A genetic fusion GDNF-C fragment of tetanus toxin prolongs survival in a symptomatic mouse ALS model

PURPOSE

Amyotrophic Lateral Sclerosis (ALS) is a paralyzing disorder that kills individuals within three to five years of onset without any possibility for effective treatment. One proposed therapy has been the use of neurotrophic factors to inhibit the apoptosis of motorneurones. At the present, one way to deliver neurotrophic factors after intramuscular injection to the motor neurones is through the use of adenoviral vectors. An alternative strategy is the use of the atoxic C fragment of tetanus toxin (TTC) as a neurotrophic factor carrier for motorneurones.

METHODS

We have produced the recombinant protein fusion Glial Derived Neurotrophic Factor and C fragment of tetanus toxin (GDNF-TTC) and we have tested its antiapoptotic activity in degeneration culture cells and in the symptomatic SOD;{G93A} transgenic animal model for ALS.

RESULTS

We demonstrated that GDNF-TTC induces the neuronal survival Akt kinase pathway in mouse cortical culture neurons and~maintains its antiapoptotic neuronal activity in Neuro2A cells. Moreover, we have found that genetic fusion is able to increase survival by 9 days and improves life quality in symptomatic ALS animal models.

CONCLUSION

These results suggest that recombinant GDNF-TTC fusion protein intramuscular injections provide a potential therapy for ALS treatment.

Endoscopic-assisted osteotomies for the treatment of craniosynostosis

INTRODUCTION

The development of multidisciplinar units for Craniofacial Surgery has led to better postoperative results and a considerable decrease in morbidity in the treatment of complex craniofacial patients.

MATERIALS AND METHODS

Standard correction of craniosynostosis involves calvarial remodeling, often considerable blood losses that need to be replaced and lengthy hospital stay. The use of minimally invasive techniques for the correction of some of these malformations are widespread and allows the surgeon to minimize the incidence of complications by means of a decreased surgical time, blood salvage, and shortening of postoperative hospitalization in comparison to conventional craniofacial techniques.

DISCUSSION AND CONCLUSION

Simple and milder craniosynostosis are best approached by endoscopy-assisted osteotomies and render the best results. Extended procedures other than simple suturectomies have been described for more severe patients. Different osteotomies resembling standard fronto-orbital have been developed for the correction, and the use of postoperative cranial orthesis may improve the final cosmetic appearance. Thus, endoscopic-assisted procedures differ from the simple strategy of single suture resection that rendered insufficient results in the past, and different approaches can be tailored to solve these cases in patients in the setting of a case-to-case bases.

[Positional plagiocephaly. Diagnosis and treatment]

INTRODUCTION

Positional plagiocephaly is nowadays the most frequent consultation at pediatric neurosurgical departments in Spain and western countries. Another important issue is the confusion existing in literature regarding terminology, physiopathology, differential diagnosis with true synostosis and, of course, proper recommendations for treatment.

OBJECTIVES

To clarify all these concepts and present a protocol that was recently asked by the Health Administration of the Community of Madrid.

PROTOCOL

Pretends to achieve coordination among paediatricians and neurosurgeons, as much as to offer precise information about data concerning this entity for parents, paediatricians and neurosurgeons.

MATERIAL AND METHODS

Previous consensus is reached about some data. Children are classified in three categories of deformation (mild; moderate; severe), according to measurements on digital photography. Diagnosis and treatment follows two phases: Paediatric phase (up to 5 months of age) and Neurosurgical phase (from 5 months on). Children would be referred to neurosurgical consultation only after being treated with postural changes and physiotherapy by the age of 5 months. Reasons are explained in the protocol that defines also functions and responsibilities for each speciality.

CONCLUSION

Treatment proposed here is staged, starting with postural changes and physiotherapy, followed by orthotic cranial devices and finally surgical treatment.

Risk assessment applied to Spain's prevention strategy against highly pathogenic avian influenza virus H5N1

Notifiable avian influenza (NAI) had never been reported in Spain, until July 2006 when a dead Great Crested Grebe (Podiceps cristatus) was found positive to the highly pathogenic H5N1 subtype as part of the active wild bird surveillance plan. The current program of the Spanish Ministry of Agriculture, Fisheries, and Food (MAPA)'s strategic preventive plan against NAI is divided in the following parts: identification of risk areas and risk wild bird species, increased biosecurity measures, early detection of infection with surveillance intensification and development of rapid diagnostic tests, and other policies, which include continuing education and training to ensure early detection of the disease. In 2003 an active surveillance plan was introduced for domestic fowl; the plan was extended to wild birds in 2004. A total of 18,780 samples in poultry and 3687 samples in wild birds had been analyzed through December 2005 to detect the presence and spread of avian influenza subtypes H5 and H7. In the present work we suggest some contributions to be implemented in MAPA's action plan: 1) the identification of risks because of migratory birds, within the risk assessment of the introduction of NAI virus in Spain and 2) an interactive digital simulator of the disease developed for continuing education and training.

Isolation and development of haematopoietic progenitor cells from peripheral blood of adult and newborn pigs

Pluripotent stem cells (PSCs), already described in human beings, are fibroblast-like cells that exhibit a CD34 marker specific for haematopoietic stem cells. In this work we have demonstrated the presence of PSCs in the peripheral blood of pigs, a species frequently used in transplantation studies as an animal model for human diseases. Differentiation into haematopoietic colonies (granulomacrophagic colonies, erythroid colonies and mixed colonies) has been carried out with the peripheral blood of adult and newborn pigs, using solely human commercial media. Peripheral blood mononuclear cells (PBMNCs) were cultured in semisolid methylcellulose based media enriched with recombinant human cytokines, achieving granulomacrophagic-colony forming unit (GM-CFU) and mixed-colony forming unit (Mix-CFU) growth with erythroblastic lineage proliferation in the presence of erythropoietin (Epo). In all the samples CFU growth was associated with the presence of recombinant human cytokine. No evidence of proliferation in control plates without cytokines was found. From liquid medium culture, a population of macrophages and CD34+ fibroblast like cells were retrieved 21 days after sowing. These findings allow us to think about the direct application of this simple and standardised method in several work fields such as the study of pharmacological effects of many drugs over the haematopoietic line and in the study of new strategies in cellular therapy for some human diseases.

Study and culture of haematopoietic progenitor cells from peripheral blood in rats, hamsters and mice

The aim of this work was to isolate and cultivate a subpopulation of pluripotent stem cells present in peripheral blood of different animal species, frequently used in laboratory studies (mice, rats and hamsters). Pluripotent stem cells (PSCs), already described in human beings, are fibroblast-like cells that exhibit a CD34 marker, specific for haematopoietic stem cells. Commonly used human commercial media were investigated for culturing animal PSCs. These findings suggest that this simple and standardized methodology may be applicable in several fields such as the study of the pharmacological effects of drugs on the haematopoietic line and the study of new strategies in cellular therapy for some human diseases.

Use of nonlinear mixed effect modeling for the intestinal absorption data: Application to ritonavir in the rat

The aim of this study is to investigate in situ the mechanisms involved in the gastrointestinal absorption of ritonavir in the rat, as an animal model for preclinical studies of anti-HIV agents in vivo. Four ritonavir solutions (40, 27, 13 and 7 microM) in the presence of 1% dimethylsulfoxide (DMSO) were perfused in the small intestine of anaesthetised rats. Effects of DMSO on the intestinal permeability were investigated using solutions containing antipyrine 1.33 mM and ritonavir 7 microM with and without 1% of DMSO. Antipyrine and ritonavir transport was not modified in the presence of 1% of DMSO. The population pharmacokinetic parameters of the ritonavir intestinal transport were obtained by means of nonlinear mixed effect modelling approach according to a nonlinear absorption and nonlinear secretion. The absorption and secretion kinetic parameters for ritonavir were: Vm=47.6 microM/h; Km=8.77 microM; Vms=3.66 microM/h and Kms=0 microM. The interindividual variability found to ritonavir Vm 13.1%, and the residual variability was 8.98%. The Kms value support the saturation of the carrier at the range of concentrations of ritonavir assayed. The interindividual variability value of the Vm could explain, at least in part, the variability in absorption rate constants observed.

Conservation of purified protein derivative RT-23 tuberculin

OBJECTIVE

Recommendations that purified protein derivative (PPD) RT-23 tuberculin should not be kept and used more than 24 to 48 hours after opening are rarely complied with. The aim of this study was to determine whether using PPD RT-23 tuberculin from vials that had been open for a longer time could affect results of tuberculin tests and whether the solution could become contaminated.

METHODS

A prospective cross-sectional study was carried out. Two tuberculin tests were simultaneously administered, one in each forearm, to adult contacts of patients with active tuberculosis, one test using a recently opened vial of tuberculin (control) and the other using tuberculin that had been opened a week before (first phase) or a month before (second phase) (study tuberculin). Leftover tuberculin from several of the vials was cultured.

RESULTS

For the 127 patients in the first group (tuberculin opened 1 week), the mean (SD) diameter of the induration was 6.2 (6.9) mm for the study tuberculin and 6.3 (6.9) mm for the control (P=.3). For the 83 patients in the second group (tuberculin opened 1 month), the mean diameter of the induration was 5.5 (7.3) mm for the study tuberculin and 5.7 (7.3) mm for the control (P=.5). There were no differences between the number of positive tests found. None of the cultured tuberculins produced bacterial growth.

CONCLUSIONS

PPD RT-23 tuberculin does not appear to lose potency or sterility when vials have been opened for a week or a month.

Gliomas del tronco encefálico

Brainstem gliomas have been increasingly understood in the last two decades and they are nowadays regarded as an heterogeneous group of tumors with tendency towards the pediatric age, where they account for 10-20% of brain neoplasms. Besides the well known diffuse tumor, several subtypes, with a different biological behaviour, amenable to surgical resection and better prognosis, have been identified, giving rise to many classifications and terms. In the other way, attention has been recently paid to adult brainstem gliomas in contrast to pediatric tumors. Based on a review of the literature, we describe the different subtypes of brainstem gliomas, with particular interest on therapeutic approaches and differences between pediatric and adult tumors, employing iconography from our series.

Fronto-orbital remodeling without orbito-naso-frontal bandeau

INTRODUCTION

Fronto-orbital bilateral advance is the procedure of choice for the treatment of craniosynostosis affecting most of the anterior area of the skull and orbitomalar regions. The aim of the technique is to achieve a supra-orbital bilateral bar and a frontal bone. We have introduced a modification in order to simplify the technique.

PATIENTS AND METHODS

From November 1998 to January 2002, 18 patients with craniosynostosis have been surgically treated using our technique. The mean age when the treatment was performed was 6.93 months (range 3 to 22 months). Brain computed tomography (CT) scans and three-dimensional (3-D) reconstruction of CT scans were performed before and after treatment.

SURGICAL TECHNIQUE

A bifrontal craniotomy was performed taking the osteotomy up to the supraorbital rim. A new frontal bone was obtained from another region of the cranium creating new orbital edges. The osteosynthesis was conducted using absorbable materials.

RESULTS

The follow-up of the patients ranged from 3 months to 3 years. All patients were studied using CT scans and 3-D reconstruction of CT after treatment, which demonstrated the persistence of the fronto-orbital advance. No secondary complications related to the new technique were found in any of the patients.

CONCLUSIONS

The frontal-orbital advance obtained was stable. The technique was simplified by not creating a supraorbital bar and by reducing the bone fixation points. The manipulation of both frontal lobes and orbital globes was negligible. The aesthetic results were excellent.

[Congenital brain tumors: nine cases and review of the literature]

OBJECTIVE

To review congenital brain tumors patients younger than 2 months diagnosed in our Department.

PATIENTS AND METHODS

Nine congenital brain tumors were diagnosed between 1983 and 2001 among a consecutive serie of 484 paediatric cerebral tumors (patients less than 15 years). Clinical and radiological findings and prognostic factors are analyzed.

RESULTS

There were two teratomas, two glioblastomas, one xanthogranuloma affecting cavernous sinus, one supratentorial PNET and one medulloblastoma and one oligodendroglioma. In one case histological diagnosis was not possible. In four cases antenatal diagnosis was done by means of ultrasonography and MRI. Seven patients were operated on, with one intraoperative exitus. Five patients died due to tumoral progression in the first two months after surgery. Another case was considered not amenable for surgical resection, and thus was not operated. He died in the fifth day of life. Three patients are alive 14, 36 and 72 months after surgery, one with severe psicomotor delay, another one with normal mental status but dependent on seizures medication and the last one with mild mental delay. In the last case of our serie intrauterine death happened by 33(rd )week and histological diagnosis was not possible.

CONCLUSIONS

Prognosis for congenital brain tumors depends on the operative morbidity and tumor histology. However final prognosis in these patients is still discouraging, despite early surgery and operative and anaesthetic improvements.

Intraventricular cavernoma in pediatric age

INTRODUCTION

Cavernomas rarely occur in the ventricular system. Only 10 pediatric cases out of 46 well-documented cases have been published.

CASE REPORT

We report the case of an 11-year-old girl operated on for a voluminous cavernoma at the ventricular trigone which was diagnosed after absence seizures.

CONCLUSION

Interestingly, the case we report showed a hypointense rim on T2-weighted magnetic resonance images which has not been a common finding in the cases previously reported.

Surgical treatment of trigonocephalies and associated hypoteleorbitism

Premature closure of metopic suture is a relatively uncommon form of craniosyostosis with an estimated incidence of 0,3 per 1000 live births, comprising about 7% of surgical craniosynostosis referred to craniofacial centers. A broad phenotypical spectrum spreads from minor metopic ridges to severe trigonocephaly with pterional indentation supraorbital bar retrusion, temporal and parietal compensating bossings and hypotelorism. Most of the cases arise spontaneously although autosomal dominant inheritance has been described and association with cromosomal abnormalities and different syndromes has been widely reported. Surgical correction has been attempted with good cosmetic results using several variations of the standard frontoorbitary advance. However there is still a number of questions to be solved in relation to this entity, mainly on its pathogenesis, but also on its development, natural history and treatment. Direct surgical approach to associated hypotelorism is a matter of argument when considering the reestablishment of normal interorbitary distances. We have conducted a retrospective analysis of our serie consisting of twenty-eight cases of trigonocephalies. Surgical correction of hypotelorism was attempted in eleven cases while the resting seven children remained "not treated". The objective was to review the functional outcome and cosmetic results comparing the different techniques applied to the frontal bone and to observe evolution of the hypoteleorbitism after the treatment with or without osteotomies and grafting of the nasoethmoidal area.

Poly(A) site choice during mRNA 3'-end formation in the Schizosaccharomyces pombe wos2 gene

In the fission yeast Schizosaccharomyces pombe, the wos2 gene encodes p23, a highly conserved protein which functions as a co-chaperone for the heat shock protein Hsp90. This p23 protein binds to Hsp90, but its activities and regulatory mechanisms are still unclear. Northern analysis has shown that the wos2 gene produces three transcripts of about 1.1, 0.9 and 0.8 kb, which are expressed differentially depending on the growth temperature. The largest and the smallest transcripts were most abundant at 25 degrees C, whereas the 0.9-kb transcript predominated at 37 degrees C. A time-course analysis indicated that this 0.9-kb species rapidly increased in abundance after a shift from 25 degrees C to 37 degrees C, reaching a maximum after 15 min. A shift back to 25 degrees C resulted in a decline in the amount of this transcript, albeit at a slower rate. Expression analysis of wos2:ura4 and nmt1:wos2 constructs showed that the 3' untranslated region of wos2 alone directs the formation of these multiple, discrete wos2 mRNAs. Sequence analysis of cDNAs derived from these mRNAs showed that the use of different polyadenylation sites results in the production of the three differently sized wos2 transcripts. In the case of the 0.9- and 0.8-kb mRNA species, these sites lie in a predicted hairpin loop in the mRNA, suggesting that polyadenylation signals in wos2 transcripts may be mediated by RNA secondary structure. The possibility that differential thermal stability of these hairpin structures could influence polyadenylation site choice during formation of the 3'-ends of the mRNAs is discussed.

[Endoscopic treatment of suprasellar arachnoid cysts]

Arachnoid cysts account for only 1% of all intracranial space-occupying lesions. In adults suprasellar cysts represent 9% of all the arachnoid cysts while in pediatric population this percentage reaches 15%. In spite of being a problem relatively common in daily neurosurgical practice there are still a number of questions to be solved concerning pathogenesis and evolution, natural history and treatment. Located in the suprasellar cistern and closely related to the ventricular system, suprasellar arachnoid cysts conform a perfect indication for endoscopic treatment. The development and spreading of neuroendoscopic techniques have surpassed the standard microsurgical approaches as an elective treatment. However there is still controversy on the management of associated hydrocephalus, need for cystoperitoneal shunt after endoscopic fenestration or the superiority of ventriculocystocisternostomy over simple ventriculocystostomy. The authors present a serie of seven consecutive patients with "de novo" diagnosis of suprasellar arachnoid cyst. In every case the treatment consisted in endoscopic fenestration and removal of the cyst membranes, with or without associated ventriculostomy of the IIIrd ventricle. Preoperative symptoms improved in all the patients and five out of seven remain shunt free. One patient maintains a cystoperitoneal shunt and another one, previously shunted, remains shunt dependent. The clinical presentation and postoperative evolution are commented with discussion on the alternative therapeutic options from the endoscopic point of view.

Evaluation of the application of pig slurry to an experimental crop using agronomic and ecotoxicological approaches

The agronomic and ecotoxicological effects of the application of pig (Sus scrofa) slurry during a maize (Zea mays L.) crop cycle under conditions of forced irrigation were evaluated. The 0.2-ha experimental area, of typical xerofluvent soil and of known vulnerability to nitrate (NO3-) contamination, was divided into 12 plots and provided with water measurement instruments (TDR-probes, vertical tensiometers, and ceramic candles). Samples of soil, water, soil organisms, and the crop were subjected to analytical, agronomic, and biological test procedures. The following fertilizer treatments were applied to triplicate plots: urea (U;170 kg N ha(-1)), and an optimized (P1; 162 kg N ha(-1)) and triple (P3; 486 kg N ha(-1)) dose of pig slurry. Unfertilized plots (P0) served as controls. Calculation was made of seasonal drainage and leached NO3- and sodium losses during the experimental period. Conductivity, heavy metal concentration, hardness, pH, and redox potential were determined in soil solutions. The ecotoxicological evaluation of the soil solution and matrix was based on ecotoxicity bioassays and the quantification of organic and inorganic compounds [phenols, indols, polychlorinated biphenyls (PCBs)]. The results suggest that the P3 treatment is highly contaminating due to the leaching of nitrates and increased soil salinity. Despite the fact that a Folsomia candida reproduction test indicated chronic ecotoxicological effects on the soil in plots treated with P1 and P3, the absence of organic compounds suggests that these effects may be attributable to contaminants not considered in this study.

Spanish intercomparisons for individual monitoring

The Spanish Nuclear Safety Council (CSN) carries out an intercomparison programme for individual monitoring every 5 years. The objective is to acquire valuable information on the performance of the dosimetry systems of the participating Spanish approved dosimetry services and to assess precision and accuracy as quality indicators of overall dosimetry performance. CSN has carried out two intercomparison programmes, the last one in 1995, in which 18 approved dosimetry services participated. The dosemeters were exposed to photon fields (137Cs gamma rays and two X ray beams of different qualities), at two standard laboratories in Spain. The irradiations were done for evaluating personal dose equivalent, Hp(10), using the ICRU 47 phantom. Presently, CSN is carrying out a new intercomparison, which will be finished in 2001. Twenty-three dosimetry services will participate; 22 from Spain and one from Cuba. The irradiations will be done in reference photon radiation fields.

Ecotoxicological evaluation of pig slurry

Swine sewage could be source of nutrients and pollutants. This work estimates the environmental risk in nine samples from different farm treatment systems based on the evaluation of their effects in Daphnia magna acute test, and on the assessment of Cu, Zn and ammonia as main contributors. NH3 and Cu were responsible for LC50 results (1-5% of dilution). Organic compounds were quantified through several extraction methods (SPMDs, SPE and solvent extraction). A more exhaustive extraction was performed in an additional sample, which showed indole and phenol recoveries much higher than the previous ones. This method also includes PCBs (430 ppb) and fatty acids (approximately =150 ppm) quantification.

[Neurocutaneous melanosis]

Neurocutaneous melanosis (NCM) is a rare congenital syndrome characterized by large or multiple congenital melanocytic nevi and excessive proliferation of melanotic cells in the leptomeninges. We report the case of a girl with a giant hairy nevus and numerous small nevi since birth. Within the first 2 years of life she developed clinical features of increased intracranial pressure and West s syndrome. At 2 years of age she presented a right facial palsy and myelopathy. Brain and spinal magnetic resonance imaging demonstrated meningeal infiltration. Diagnosis of NCM was established by a detailed cytologic analyses of the cerebrospinal fluid that revealed melanocytic cells. She received palliative treatment. The girl died 2 months after. Patients with large or multiple congenital melanocytic nevi should be carefully followed up with clinical examination and neuroimaging to detect NCM. At present there is no curative treatment. The association of NCM and West s syndrome has not been previously described.