Exceptional points and non-Hermitian degeneracy of resonances in a two-channel model

We study the mixing and degeneracy of two unbound energy eigenstates (resonances) in a two coupled channel model of scattering and reactions. We derive the necessary and sufficient conditions for existence of an exceptional point in the extended spectrum of bound and resonance energy eigenvalues in this model and show that these are not the same as in the single channel case. When these conditions are satisfied, in the complex energy plane, the two simple resonance poles of the scattering matrix merge into one double pole at the exceptional point. In parameter space, the surface of the eigenenergies has a branch point of square root type and branch cuts in its real and imaginary parts that start at the exceptional point and extend in opposite directions. The rich phenomenology of crossings and anticrossings of energies and widths of the doublet of unbound states, as well as the changes of identity of the poles of the scattering matrix observed when one control parameter is varied while the other is kept constant, is fully explained in terms of sections of the eigenenergy surfaces.

Effect of temperature on pupa development and sexual maturity of laboratory Anastrepha obliqua adults

The effect of four temperatures (18, 20, 25 and 30°C) on pupa development and sexual maturity of Anastrepha obliqua adults was investigated under laboratory conditions. The results showed that the duration of the pupal stage decreased with an increase in temperature (29, 25, 13 and 12 days, respectively), and maintaining the pupae at 18°C and 20°C results in a low percentage of pupation, pupa weight loss and lesser flying ability. However, it significantly favored sexual behavior, a higher proportion of sexual calls and matings. While enhanced pupa development was observed at a temperature of 30°C, adults had low sexual efficiency, as well as a lower proportion of calls and matings. Gas chromatography-mass spectrometry (GC-MS) analysis of male volatiles showed that the amount of (Z,E)-α-farnesene did not vary among males from pupae reared at different temperatures; however, less (E,E)-α-farnesene was emitted by males obtain from pupa reared at 30°C. Male flies kept at 30°C during their larval stage had more (Z)-3-nonenol and, also, an unknown compound was detected. The fecundity of the females was higher at low temperatures. Regarding fertility, no significant differences were found between temperatures. The optimal temperature on pupa development was 25°C when males displayed ideal attributes for rearing purposes.

Newly Discovered Natural Hosts of Tomato chlorosis virus in Costa Rica

Tomato chlorosis virus (ToCV) is an emerging whitefly-transmitted crinivirus (2). In Costa Rica in 2007, ToCV was detected in field-grown and greenhouse tomato (Solanum lycopersicum L.) plants causing symptoms of severe yellowing and foliar chlorosis (1). To identify alternative hosts that may serve as virus reservoirs, 78 samples were collected from multiple species of common weeds growing adjacent to tomato nurseries in the Cartago Province, where ToCV was previously identified, during the autumn of 2008 and summer of 2009. The weeds were collected on the basis of the presence of whiteflies and/or symptoms of interveinal chlorosis, but not all samples were symptomatic for infection by ToCV. Total RNA was extracted from leaf tissue with TRI Reagent (Molecular Research Inc., Cincinnati, OH). Reverse transcription (RT)-PCR reactions were performed with the Qtaq One-Step qRT-PCR SYBR Kit (Clontech Laboratories, Mountain View, CA) and primers specific for the ToCV HSP70h gene (3). A 123-bp DNA fragment was amplified in five weeds, which were identified taxonomically as Ruta chalepensis (Rutaceae), Phytolacca icosandra (Phytolacaceae), Plantago major (Plantaginaceae), a Brassica sp. (Brassicaceae) (two samples), and a single plant of Cucurbita moschata (Cucurbitaceae) growing next to those weeds. The amplified DNA fragments were sequenced and BLAST analysis showed 100% nucleotide sequence identity with the HSP70h gene of the Florida ToCV isolate (GenBank Accession No. AY903448). To confirm the presence of ToCV in these six weed samples, conventional RT-PCR reactions were performed using primers specific for the ToCV CPm and p22 genes as described previously (1). Nucleotide sequence analysis of the amplified DNA fragments verified their identity as ToCV, with 100% sequence identity to the CPm of the ToCV isolate of Florida (Accession No. AY903448) and the p22 gene of the Cartago, Costa Rican isolate (Accession No. FJ809714). Although the number of samples analyzed is not sufficient to allow a determination of the role of weed reservoirs in ToCV epidemics in Costa Rican tomato crops, this report on the wider natural host range of ToCV in Costa Rica may lead to a better understanding of the epidemiology of this virus and be useful in the development of disease management strategies. To our knowledge this is the first report of these weeds as natural hosts of ToCV. References: (1) R. M. Castro et al. Plant Dis. 93:970, 2009. (2) M. I. Font et al. Plant Dis. 88:82, 2004. (3) W. M. Wintermantel et al. Phytopathology 98:1340, 2008.

Review: Freeze Concentration Technology Applied to Dairy Products

Freeze concentration is a process of concentrating liquid products by freezing the water content and subsequently removing the so-formed ice crystals from the food system. In dairy processing, this technology offers the advantage of minimizing the heat abuse of sensitive milk components, such as proteins and flavors. It thus provides an opportunity for producing dairy ingredients with enhanced functional and organoleptic qualities. By freeze concentration, skim milk has been concentrated up to 40 wt% total solids (TS) and whole milk up to 44 wt% TS. Lactose and lipids are more concentrated in the ice fraction than in the concentrated fraction. Proteins (casein and whey protein) decrease the ice growth rate and the high viscosity is a limiting factor for the freeze concentration of both skim milk and whole milk. In this study, the most important studies relating to the suspension, block and layer freeze concentration of milk are summarized, analyzing results and indicating how freeze concentration process efficiency of dairy products can be improved.

[Treatment of distal ureteral stricture by laparoscopic ureterovesical reimplantation]

INTRODUCTION

to analyse the results achieved to treat iliac or pelvic ureteric stricture using laparoscopic reimplantation of the ureter in a psoic bladder.

MATERIAL AND METHOD

in a four-year period, we performed laparoscopic ureteral reimplantation in a psoic bladder in 6 patients (right/left 1:1; male/female 1:2; mean age 59.2 years, range 47-87). In 4 cases the lesion was iatrogenic and in 2 cases idiopathic. Ureteral resection with bladder cuff and cystorraphy followed by ipsilateral lymph node dissection was performed in idiopathic cases or those with history of previous urothelial tumour (4 cases in total) before ureteral reimplantation. Bladder was extensively mobilized and fixed to minor psoas tendon before performing ureteroneocystostomy. Mixed intra and extravesical technique with submucosal tunnel (Politano) was used in a case and in the remaining 5 cases extravesical technique with submucosal tunnel (Goodwin) was used. Mean follow-up was 26 months (range 18-34).

RESULTS

there was no need to convert to open surgery. Time of surgery was 230 minutes in the case treated with Politano ureteroneocystostomy and 120 (range 75-150) in those treated purely extravesically. The mean hospital stay was 3.2 days (range 2-5). There were no intra or postoperative complications. Histologic assessment always revealed ureteral fibrosis and in 2 cases accompanying granulomatous inflammation and dysplasia. No patient suffered re-stricture or impairment in renal function during follow-up.

CONCLUSIONS

laparoscopic ureteral reimplantation is an effective and safe minimally invasive technique to treat benign distal stricture of the ureter. Simplicity of extravesical reimplantation has an advantage over its intravesical counterpart.

Presence in the media of the topic "donation and transplantation of organs and tissues" during the 2005 to 2007 period in Venezuela as a strategy to improve its perception in Venezuelan society

INTRODUCTION

Media are main allies to encourage donation and transplantation. We sought to quantify the presence in the media of the topic "Donation and transplantation (D/Tx)" during the period 2005 to 2007 and to determine the relationship between the volume of information issued by the media and indexes related to the topic.

METHODS

We conducted a systematic recording of the news on the topic of D/Tx in print, radio, and television during 2005 to 2007.

RESULTS

There was an increased presence in the media by 100% in 2005 and 2006, and by 200% in 2007. The presence in print media was greater than radio (249 +/- 31.5 vs 131 +/- 5.49; P = .05) or television (249 +/- 31.5 vs 92 +/- 7.12; P = .01). We observed a positive correlation between the total number of contacts versus the number of registered volunteer donors (R(2) = 0.9713) and number of contacts versus total number of transplants from cadaveric donors (CTX; R(2) = 0905). The index CTX per million population increased by 30% (2006 vs 2005) and 100% (2007 vs 2005). The percent of family refusals fell from 41% in 2005 to 34% in 2006 and to 31% in 2007. The rate of donors per million population grew steadily from 1.8 in 2005 to 2.3 in 2006, and to 3.6 in 2007.

CONCLUSION

The sustained increase in D/Tx briefing as a strategy of Sistema de Procura de Organos y Tejidos has helped to foster a positive perception that is reflected in the increased rate of donation and transplantation in Venezuela.

Compative study of bladder versus enteric drainage in pancreas transplantation

INTRODUCTION

There is some controversy concerning the choice of best technique for drainage of exocrine secretions in pancreas transplantation. We compared patients with bladder drainage (BD) versus those with enteric drainage (ED).

PATIENTS AND METHODS

From March 1995 to September 2008, 118 patients (68 men and 50 women) of overall mean age of 37.8 +/- 7.8 years underwent pancreas transplantation. There were 109 simultaneous pancreas-kidney, and 9 pancreas after kidney procedures. Recipients were divided in a BD (n = 66 patients) and an ED group (n = 52).

RESULTS

Donor characteristics were similar in both groups. Thirty-two patients (48.5%) of the BD group versus none in the ED group experienced urinary tract infections (UTI; P < .001), and 16 patients (24.2%) BD versus 15 (29.4%) ED developed intraabdominal infections (P = NS). The overall rate of relaparotomies was 33.9% (n = 40): 34.8% (n = 23) in the BD versus 32.7% (n = 17) in the ED group (P = NS). Thirty patients (25.4%) lost their pancreas grafts: 21 (31.8%) in the BD group versus 9 (17.3%) in the ED group (P = .055). The acute rejection rates were 12.7%; namely, 15.2% in the BD versus 9.8% in the ED (P = NS). Three-year patient and graft survivals were equivalent in both groups: 96.1% and 65.3% in the BD versus 89.0% and 74.0% in the ED group, respectively (P = NS).

CONCLUSIONS

ED is a good alternative to BD for drainage of pancreatic graft exocrine secretions because both techniques have the same patient and graft survival, but BD is associated with a significantly higher rate of UTI and urologic complications.

Recovery of proteins from wastewater of tannery beamhouse operations: influence on the main pollution parameters

The recovery of proteins from effluents of beamhouse operations in a hair-pulping process of hides is proposed. Precipitation with sulphuric acid at the isoelectric pH was chosen for protein recovery. The precipitates were characterized in order to study their potential uses. Apart from the protein nitrogen, the precipitate also contained a considerable content of fats resulting from the co-precipitation of natural fat of the hide in the wastewaters. The precipitation of the protein fraction resulted in a reduction of 80-85% of COD, whereas the protein content decreased 68-78%. This diminution of the contamination load led to a notable reduction of the tax on wastewater. The content of protein material in the precipitate varied from 15 to 44%. As expected, the protein in the precipitate did not result from the collagen decomposition of the hide but from soluble proteins such as albumin and globulin and remains of keratin. The precipitates obtained met the maximum limits of heavy metals according to legislation on organic fertilizers. The potential uses of the protein fraction recovered from tannery wastewaters are currently being investigated.

Review. Freeze Concentration in the Fruit Juices Industry

In conventional processes, such as evaporation, higher levels of concentration can be reached compared with freeze concentration or membrane techniques. However, the advantage of the freeze concentration technique is based on the quality of the product obtained due to the low temperatures used in the process, which makes it a very suitable technology for the processing of fruit juices. There are two basic methods for concentrating solutions by freezing: suspension and film freeze concentration. Suspension freeze concentration systems (FCS) already have operating equipment in the food industry, while film FCSs, also called layer crystallization, is still at an experimental stage. This review summarizes the most important studies relating to the suspension and film freeze concentration in fruit juices and sugar solutions, illustrating the different possibilities that freeze concentration has in the fruit juices industry; it also presents trends and suggests improvements for the future development of this technology. It is noted that most recent publications refer to the film FCS. The technology used to design, build and maintain layer crystallization equipment is simple and it can be available to any operator in the food industry, layer systems will be used in the future if their results can be improved in terms of ice purity and degree of fluid concentration.

Bacterial community dynamics during bioremediation of diesel oil-contaminated Antarctic soil

The effect of nutrient and inocula amendment in a bioremediation field trial using a nutrient-poor Antarctic soil chronically contaminated with hydrocarbons was tested. The analysis of the effects that the treatments caused in bacterial numbers and hydrocarbon removal was combined with the elucidation of the changes occurring on the bacterial community, by 16S rDNA-based terminal restriction fragment length polymorphism (T-RFLP) typing, and the detection of some of the genes involved in the catabolism of hydrocarbons. All treatments caused a significant increase in the number of bacteria able to grow on hydrocarbons and a significant decrease in the soil hydrocarbon content, as compared to the control. However, there were no significant differences between treatments. Comparison of the soil T-RFLP profiles indicated that there were changes in the structure and composition of bacterial communities during the bioremediation trial, although the communities in treated plots were highly similar irrespective of the treatment applied, and they had a similar temporal dynamics. These results showed that nutrient addition was the main factor contributing to the outcome of the bioremediation experiment. This was supported by the lack of evidence of the establishment of inoculated consortia in soils, since their characteristic electrophoretic peaks were only detectable in soil profiles at the beginning of the experiment. Genetic potential for naphthalene degradation, evidenced by detection of nahAc gene, was observed in all soil plots including the control. In treated plots, an increase in the detection of catechol degradation genes (nahH and catA) and in a key gene of denitrification (nosZ) was observed as well. These results indicate that treatments favored the degradation of aromatic hydrocarbons and probably stimulated denitrification, at least transiently. This mesocosm study shows that recovery of chronically contaminated Antarctic soils can be successfully accelerated using biostimulation with nutrients, and that this causes a change in the indigenous bacterial communities and in the genetic potential for hydrocarbon degradation.

Streptococcosis on a red tilapia, Oreochromis sp., farm: a case study

A commercial red tilapia farm was diagnosed with Streptococcus agalactiae infection using histopathology, microbiology and immunohistochemistry. One hundred fish were randomly taken from different weight/age groups including broodstock, market fish (larger than 150 g), on-growing fish between 20 and 150 g, juveniles and larvae. Fish were clinically examined, anaesthetised and necropsied. Samples were taken from brain, liver, spleen, eyes and kidney for microbiology. All organs were processed for histopathology and an indirect immunoperoxidase test (IIP). Organs from wild fish and birds found in close proximity to the farm were also sampled for microbiology and IIP. The prevalence of lesions or infection found by IIP, histopathology and microbiology was 16%, 29% and 7% respectively. Clinical disease, lesions or infection were not seen in larvae or juveniles. By contrast, infection and disease were found in fish larger than 20 g, suggesting that the condition was linked to the intensive culture conditions of broodstock, on-growing and market fish. S. agalactiae was not found in wild fish, or in birds, by microbiology and IIP.

5-Lipoxygenase pathway gene polymorphisms: lack of association with asthma in a Spanish population

BACKGROUND

Cysteinyl-leukotrienes are mediators of inflammatory responses in bronchial asthma. We studied the genes encoding the enzymes involved in their synthesis to identify risk factors for asthma. The promoter polymorphisms LTC4S -444 A/C, ALOX5 -176/-147, and ALOX5AP -169/-146 have been reported to be associated with bronchial asthma.

METHODS

We analyzed the effects of LTC4S -444 A/C, ALOX5 -176/-147, and ALOX5AP -169/-146 on asthma susceptibility by means of a case-control study with 193 ethnically matched, unrelated individuals. Participants were classified as severe asthmatics, nonsevere asthmatics, and nonasthmatics, using a combination of 2 techniques: polymerase chain reaction-restricted fragment length polymorphism and multiplex capillary electrophoresis.

RESULTS

No association was found between these polymorphisms and asthma, neither individually nor in combination.

CONCLUSION

Although the studied polymorphisms have been previously reported to constitute risk factors for the disease, we found no association between LTC4S -444 A/C, ALOX5 -176/-147, and ALOX5AP -169/-146 polymorphisms and bronchial asthma.

[Genetic diagnosis of autosomal dominant polycystic kidney disease using multiplex-PCR]

BACKGROUND

Autosomal Dominant Polycystic Kidney Disease (ADPKD) is the most common life-threatening hereditary disease. Molecular analysis with highly polymorphic short tandem repeats, located in the vicinity of the two genes responsible for the disease (PKD1 and PKD2), is used to confirm diagnosis and give genetic counseling to members of affected families.

METHODS

We have developed a new assay to genotype five PKD1 and four PKD2 markers, based on two multiplex PCR reactions, and capillary electrophoresis analysis. A total of 110 subjects, belonging to 14 affected families, were genotyped to confirm the concordance with the singleplex method used previously.

RESULTS

The amplicons ranged from 95 to 154 bp in length, and complete STR profiles were obtained from 1-5 ng DNA. The specificity of the multiplex PCR system was 88,5% (95%CI= 75,9-95,2), and the sensitivity, 87,9 (95%CI= 76,1-94,6).

CONCLUSIONS

This is a useful strategy that, together with automated computer-based allele detection, allows reliable, simple, faster, and cheaper genetic analysis than the previous singleplex method.

[Impact in our environment of a gastroschisis therapeutic management protocol]

INTRODUCTION

Continuous exposure to amniotic in fetus with gastroschisis, leads to inflammation and edema of intestinal loops, hindering intestinal return to abdomen and making staged repair necessary in many cases. Furthermore, intestinal loops are hipoperistaltic, which leads to oral toleration difficulties, large periods of parenteral nutrition and an increase of hospital stay. The objective of this study is to evaluate the results in our environment, of a new multidisciplinary management protocol in patients with a prenatal diagnosis of gastroschisis.

PATIENTS AND METHODS

Between January 2003 and May 2006, six cases of prenatal diagnosis of gastroschisis were included in the protocol. This consisted in a weekly ultrasound monitorization of the gestants which showed prenatal diagnosis of gastroschisis and elective delivery by caesarean section on the 39th week and if early signs of intestinal suffering appear (bowel diameter > 17 mm or wall thickening > 3 mm), in order to prevent harm to intestinal loops and its consequences in the neonatal period. After birth, bowel reduction through the defect was performed under general anaesthesia in the operating room. Gestational age at delivery, bowel appearance, associated anomalies, incidence of sepsis and intestinal obstruction in the postoperative period, PN and hospital stay are analyzed in a prospective descriptive study.

RESULTS

Mean gestational age at delivery was 36,3 weeks (range 35-38). In all the cases, except one, bowel loops presented a nearly normal appearance, without signs of chronic inflammation. As associated anomalies we found two cases of intraabdominal testis and one of hypertrophic pyloric stenosis. No evidence of intestinal atresia in any case. Mean time of PN was 28 days. Two patients developed sepsis with good outcome with intravenous antibiotics treatment. No cases of intestinal obstruction in the immediate or late postoperative period were observed. Mean time of hospital stay was 38,8 days, with mean stay in neonatal care unit of 4 days.

CONCLUSIONS

. Weekly ultrasound monitorization assessment in cases of prenatally-diagnosed gastroschisis allows early detection of bowel suffering signs, before chronic inflammatory damage of the herniated intestinal loops. The application of this prenatal gastroschisis management protocol permits normal gestation without having to anticipate delivery in practically all cases, minimizing consequences of prematurity.

[Endoscopic treatment of recurrent tracheoesophageal fistula]

Repermeabilization of the tracheoesophageal fistula (RTE) is one of the major complications of the esophageal atresia with tracheal fistula. We present the long term results of our technique based on broncoscopic treatment with fibrin glue and diathermia.

MATERIAL AND METHODS

A retrospective study of 10 children with RTE treated from 1993 to 2006, their ages ranging from 14 days-old to 4 years-old; there were 4 patients from other hospitals. One of the patients involved had a superior congenital fistula that had not been noticed during open surgery. Broncoscopic procedure was performed using rigid instrumentation. The fistula was sealed with fibrin glue; the last seven patients in the series received previous diathermia with an uretheral catheter. Clinical and radiological follow up took place in all children. Endoscopic evaluation was performed in 6 of them. Follow-up time vary from 1 to 13 years and the number of sessions was limited to 3 per patient.

RESULTS

Closure of the fistula was confirmed in 9 cases (90%) who required a whole number of 15 sessions (Mean: 1.5). The group who received diathermia needed 9 sessions (Mean: 1.2). There were no major complications.

DISCUSSION

Surgery reparation of RTE is often related to serious complications. Therefore, many groups have tried to develop several broncoscopic techniques using different materials. Scientific reviews have not pointed out a definitive option since they involve isolated patients with no long term evolution. Taking this report into account we believe that the application of diathermia and fibrin glue ought to be considered the first choice treatment for the RTE.

[Laparoscopic Kasai portoenterostom: present and future of biliary atresia treatment]

INTRODUCTION

Kasai's operation has proved its value in surgical treatment of biliary atresia (BA). Its laparoscopic approach is a new challenge for pediatric surgeons, with all the potential advantages of minimally invasive surgery. The aim of the present study has been to report our experience in laparoscopic management of five patients with biliary atresia.

PATIENTS AND METHODS

The average of age of five patients with biliary atresia, three boys and two girls was 58 days (range 40-64). Pre and postoperative management included antibiotic prophylaxis and choleretic treatment. Laparoscopic procedure was accomplished using one umbilical 10-mm trocar and two additional 5-mm trocars. We carried out the same technique in all the patients except in one of them with a total situs inversus and who compelled us to modify the original procedure.

RESULTS

All five patients underwent a laparoscopic procedure, conversion was not necessary. The mean surgical time was 3 hours and 40 minutes (range: 5:30 y 3:10). There were not intra operative complications and all of them had a satisfactory recovery, except for the patient with situs inversus, who suffered a small bowel volvulus 9 days after the operation, leading us to perform an extensive bowel resection. All the patients, except this one, showed signs of adequate bile flow, with disappearance of clinical cholestasis. Biochemistry test became normal.

CONCLUSIONS

Besides the certain advantages compared with conventional surgical procedures (lower surgical damage, diminished post-operative recovery), laparoscopic management of BA, allows a better exposure of the porta hepatis without hepatic mobilization so it shows similar or better preliminary results than conventional techniques. The advantages of laparoscopic portoenterostomy are yet to be proved whenever liver transplantation is indicated.

Extracellular proteases from the Antarctic marine pseudoalteromonas sp. P96-47 strain

The extracellular protease-production capacity of 33 bacterial isolates taken from marine biotopes in King George Island, Antarctica, was evaluated in liquid cultures. The P96-47 isolate was selected due to its high production capacity and was identified as Pseudoalteromonas sp. The optimal growth temperature was 20 degrees C and the optimal for protease production was 15 degrees C. Proteases were purified from culture supernatants, developing a multiple-band profile in zymograms. They were classified as neutral metalloproteases and worked optimally at 45 degrees C with an Eact of 47 kJ/mol. Their stability was higher at neutral pH, retaining more than 80% of activity at pH 6-10 after 3 h incubation at 4 degrees C. After 90 min incubation at 40 and 50 degrees C, the percentages of residual activities were 78% and 44%. These results contribute to the basic knowledge of Antarctic marine proteases and also help evaluate the probable industrial applications of P96-47 proteases.

Pancreas preservation with the University of Wisconsin versus Celsior solutions

INTRODUCTION

The use of Celsior solution for organ preservation has not been thoroughly studied in pancreas transplantation. The aim of this study was to compare University of Wisconsin and Celsior solutions for preservation of pancreas grafts.

PATIENTS AND METHODS

From March 1995 to December 2005, 72 patients with type 1 diabetes underwent pancreas transplantation. There were 42 men and 30 women, with a mean age at transplantation of 38.1 +/- 7.5 years (range: 27 to 55 years), and a mean duration of diabetes of 22.5 +/- 6.6 years. Recipients were classified into two groups according to the preservation solution: (A) Celsior (n = 28, 38.9%) and (B) Wisconsin (n = 44, 61.1%).

RESULTS

The donor and recipient characteristics were similar in both groups. There were five cases of venous thrombosis in the Wisconsin group and two in the Celsior group (P = NS). The venous drainage technique in the former group was portocaval in 19 patients and portoiliac in 25; in the Celsior group, portocaval in 23 patients and portoiliac in five (P = .001). Enteric drainage was used in 19 patients from the Celsior group and 17 patients from the Wisconsin group (P = .01). Actuarial 2-year graft survival was 74.6% in the Wisconsin group and 77.4% in the Celsior group (P = NS).

CONCLUSIONS

No differences were observed in venous thrombosis between the two groups. The lower rate of venous thrombosis with the portocaval technique was related to the type of venous drainage rather than the type of preservation solution. Celsior solution may be considered as good as Wisconsin solution for pancreas transplantation.

Tonic and phasic differential GABAergic inhibition of synaptic actions of joint afferents in the cat

The aim of this study was to examine the functional organization of the spinal neuronal networks activated by myelinated afferent fibers in the posterior articular nerve (PAN) of the anesthetized cat. Particular attention was given to the tonic and phasic GABAa inhibitory modulation of these networks. Changes in the synaptic effectiveness of the joint afferents were inferred from changes in the intraspinal focal potentials produced by electrical stimulation of the PAN. We found that conditioning stimulation of cutaneous nerves (sural, superficial peroneus and saphenous) and of the nucleus raphe magnus often inhibited, in a differential manner, the early and late components of the intraspinal focal potentials produced by stimulation of low and high threshold myelinated PAN afferents, respectively. The degree of the inhibition depended on the strength of both the conditioning and test stimuli and on the segmental level of recording. Conditioning stimulation of group I muscle afferents was less effective, but marked depression of the early and late focal potentials was produced by stimuli exceeding 5 xT. The i.v. injection of 1-2.5 mg/kg of picrotoxin, a GABAa blocker, had relatively minor effects on the early components of the PAN focal potentials, but was able to induce a significant increase of the late components. It also reduced the inhibitory effects of cutaneous and joint nerve conditioning on PAN focal responses. Conditioning autogenetic stimulation with high-frequency trains depressed the PAN focal potentials. The late components of the PAN responses remained depressed several minutes after discontinuing the conditioning train, even after picrotoxin administration. The present observations indicate that the neuronal networks activated by the low threshold PAN afferents show a relatively small post-activation depression and appear to be subjected to a minor tonic inhibitory GABAa control. In contrast, the pathways activated by stimulation of high threshold myelinated afferents have a strong post-activation depression and are subjected to a significant tonic GABAergic modulation. These contrasting features, together with the phasic differential GABAergic inhibition of the responses produced by stimulation of the different populations of joint afferents, may contribute to the preservation of the original information on joint position transmitted by large diameter joint afferents, in contrast with the tonic presynaptic inhibition exerted on the fine myelinated joint afferents, which may be involved in the adjustment of compensatory reactions to inflammation.

[Choledocal cyst: analysis of 29 cases and review or the literature]

The aim of the present study has been to systematize the clinical presentation of the entity named choledochal cyst, in relation with its probable etiopathology and the intraoperative findings as well as its evolution after surgery, based on the revision of the literature and of our experience in 29 cases.

MATERIAL AND METHODS

29 cases of cystic dilatation of the biliar duct extra and/or intrahepatic are analyzed. In 4 cases the diagnosis was prenatal and two were excluded of the study after it has been confirmed they suffered biliary atresia type I. In the left 27 cases, 19 variables are analyzed retrospectively, like age, sex, weight, symptoms, ultrasonographic images, etc. Subsequently, intra-operative cholangiographic findings were correlated with the clinic presentation and the evolution of the patients after surgery.

RESULTS

Of the 27 cases analyzed 16 (59,25%) were cystic dilatations from which 14 had a neonatal or early clinic presentation (before 2 years), however the fusiform dilatations were presented later on. From the analyzed symptoms, in relation with the age only the pain and the jaundice showed significant differences, being the pain most frequent in later presentation ande the jaundice in the early form. The two cases of type 3 of Todani or choledochocele were of later presentation. An anomaly in the bilionpacreatric junction was detected in 15 patients; the majority had a later presentation, associated to pancreatitis in 4 cases. Primary cyst excision and biliary Roux-en-Y reconstruction was the treatment of election in the majority of cases. In 3 cases we used the appendix to replace the choledocus, but all three cases were reconverted two years later because of permanent elevation of ALT and GGT.

CONCLUSIONS

In favour of the literature and of our experience nowadays it would be possible to systematize this malformation and make a division in two groups, depending on the cholangiographic findings and clinical presentation: 1. Cystic dilatations with a clinical neonatal presentation or beneath 2 years. 2. Fusiform dilatations with a later clinical predominance and associated frequently to pancreatitis and anomalous pancreatobiliary junction. Choledochocele is an entity that must be considered not only for its etiology but for its clinical presentation and treatment. Primary cyst excision and biliary Roux-en-Y reconstruction is the treatment of election. Regular long-term review of these patients is mandatory in the surveillance of sub-clinic cholangitis and the risk of possible long-term malignance of this entity.

The impact of the summer 2003 heat wave in Iberia: how should we measure it?

We present a new approach to improve the reliability of quantifying the impact of a heat wave on mortality rates. We show, for the recent European summer 2003 heat wave, that the use of absolute maximum temperature values, or number of days above a given threshold, can be misleading. Here, we have assessed the impact of the heat wave on Iberian mortality by applying a four step procedure: (1) calculating, for each observatory, the local maximum temperature (T (max)) distributions, (2) calculating the corresponding 95th percentile values (T (threshold)), (3) locally defining extremely hot days (EHD) as those days on which the local threshold of the 95th percentile of the series is exceeded, and (4) calculating the total degrees-days (DD) of exceedance, by calculating the difference T (max)-T (threshold) and summing these values for all days above T (threshold). We show that the relationship between summer mortality rates and the DD index is non-linear and can be described by a logarithmic function, with a correlation coefficient of 0.78, which explains 60.6% of the mortality variance (F value of 24.64, significant at P<0.0001). Using maximum temperatures, no significant relationship is found with mortality, whereas the EHD frequency shows a significant association with mortality, albeit weaker than that obtained with DD.

Rapamycin at Six Years Can Exhibit Normal Renal Function Without Proteinuria or Neoplasia After Renal Transplantation. A Single-Center Experience

Currently, long-term experience with Rapamune (RAPA) after renal transplantation is scarce. We present our experience with RAPA in patients who were included in clinical trials. Between 1996 and 1999, 27 renal transplant patients received RAPA alone or in combination with cyclosporine (CyA). We study 15 of them (9 males, 6 females; mean age 36 years) who are currently functioning with a mean follow-up of 6 years (range, 5.2-8 years). The presence of delayed graft function was 40% and acute rejection 26.6%, all of them controlled with steroids. Notably, no patients experienced an acute rejection episode after the first year. Among 15 patients, 12 received steroids, RAPA and CyA; and 3 received steroids, RAPA, azathioprine (AZA) or mycophenolate mofetil (MMF) for immunosuppression. At the end of follow-up, the situation was the opposite: 12 patients received steroids (2.5-5 mg/d) and RAPA associated with or without AZA/MMF, and 3 were maintained with steroids, RAPA and CyA. Renal function was excellent in the entire group: mean SCr 1.1 mg/dL (range, 0.7-1.8) with mean RAPA blood levels (HPLC) of 11 ng/dL (range 8-16). Hyperlipidemia was universal with all patients (100%) receiving statins maintaining acceptable levels of cholesterol (mean 209 +/- 28 mg/dL) and tryglycerides (mean 154 +/- 76 mg/dL). Arterial hypertension present in 12 of 15 (80%) patients was controlled with a mean of 1.5 drugs. Notably, no patient presented with proteinuria, neoplasia, posttransplant diabetes, or cardiovascular events. In conclusion, these single-center results suggest that Rapamune may be useful in the long-run after renal transplantation. The presence of normal renal function and the absence of proteinuria and neoplasia in these renal transplant patients may have important clinical implications.

Ten Years of Treatment With Tacrolimus Is Related to an Excellent Renal Function, Allowing Monotherapy in a Large Proportion of Cases: Unicentric Results of the Tacrolimus Versus Cyclosporine A European Multicentric Study in Kidney Transplant Patients

Tacrolimus (Tac) is the most frequently used base inmunosuppressant for transplantation in Spain and the United States. However, long-term data on its use in renal transplant patients are lacking. The aim of this study was to analyze the 10-year outcome of patients from our institution treated with Tac or cyclosporine (CsA) who were included in the European Multicenter Study of kidney transplantation (1993 to 1994). This trial compared the efficacy and safety of steroids + Tac + azathioprine versus steroids + CsA + azathioprine at 1 year, showing a significantly lower acute rejection rate in Tac patients, with no differences in graft or patient survival. In our long-term analysis, we included patients with a functioning graft after the first year: 15 patients on Tac and 11 on CsA. In the "intent-to-treat" (ITT) analysis, patient survival was 14/15 (93%) versus 9/11 (82%) and death noncensored graft survival was 10/15 (67%) versus 8/11 (73%) in Tac and CsA, respectively. Analyzing patients "into treatment" (TT), death/noncensored graft survival was 11/16 (69%) versus 6/9 (67%), respectively. Serum creatinine tended to be lower in Tac group (ITT 1.26 +/- 0.42 vs 1.63 +/- 1.16 mg/dL, P = NS; TT 1.23 +/- 0.4 vs 1.86 +/- 1.28 mg/dL, P = NS). However, in the TT analysis, Tac patients exhibited a significantly better creatinine clearance (89.3 +/- 40 vs 46.8 +/- 21 mL/min, P = .037) and lower systolic blood pressure (125 +/- 5 vs 140 +/- 12 mm Hg, P = .007) at 10 years. No other significant differences were observed in blood pressure, lipid profile, or glucose metabolism. Outstandingly, Tac monotherapy was the most frequently used regimen after 10 years: ITT 6/9 (67%) versus 1/8 (12.5%), P = .05, TT 7/10 (70%) versus 0/6 (0%), P = .011. Patients under Tac monotherapy exhibited an excellent graft function (serum creatinine 1.08 +/- 0.14 mg/dL) and negative proteinuria, with Tac trough levels of 7.9 +/- 1.3 ng/mL. In summary, our results suggest that Tac-based immunosuppression provides an excellent kidney function 10 years after transplantation and allows monotherapy in a high percentage of kidney transplant patients.

Energy eigenvalue surfaces close to a degeneracy of unbound states: crossings and anticrossings of energies and widths

The rich phenomenology of crossings and anticrossings of energies and widths, as well as the sudden change in shape of the S(E)-matrix pole trajectories, observed in an isolated doublet of resonances when one control parameter is varied, is fully explained in terms of sections of the energy eigenvalue surfaces in parameter space close to a degeneracy point.

Note. In Vitro Viability of Bifidobacterium Strains Isolated from Commercial Dairy Products Exposed to Human Gastrointestinal Conditions

Levels of bifidobacteria contained in commercial fermented milks in Spain were determined by fluorescent techniques. The transit tolerance of probiotic bifidobacteria strains to human gastrointestinal tract (GIT) was assessed in vitro. The number of bifidobacteria in commercial fermented milks declared to contain bifidobacteria varied from 104 to 107 bacteria/m L. Viable cell counts estimated by plating onto selective media were lower than direct counts. Bifidobacteriumstrains analysed showed different survival behaviour. Viable bacteria counts decreased considerably following exposure to gastric juice. As only intrinsic acid resistant cells survive their passage through the human intestine, the selection of acid tolerant strains is necessary for the elaboration of probiotic products. Viability of dairy bifidobacteria is affected by gastrointestinal juices but the majority of tested strains survived well at gastrointestinal conditions. The reason for this may be the low number of viable bifidobacteria contained in commercial dairy products. Adaptation and survival at low pH is likely to determine the efficacy of Bifidobacterium strains both as dairy starters and probiotic microorganisms. This study confirmed the usefulness of fluorescent techniques for a rapid and accurate evaluation of bacterial viability in probiotic products.

[Spinal cord and vertebral column injuries in children]

AIMS

Analysis of main factors of spinal cord and vertebral column injuries in our environment.

METHODS

We reviewed the data collected from the patients (n = 2640) admitted to our hospital because of trauma and included in our Registry from January 1995 to April 2002. Among this group, 86 patients (3.3%) had spinal cord and vertebral column injuries and were included in the study.

RESULTS

Group gender distribution was 45 males and 41 females. In our group, 71 patients suffered vertebral fractures, 3 of them with spinal cord injuries (4.2%), 13 patients with vertebral subluxation, 11 of them between C1-C2, and 2 patients with spinal cord injury without radiographic abnormality. Only 71 patients, 4.9% of the total of the patients who were admitted with any type of fracture (n=1457), suffered vertebral fractures. These patients suffered 130 vertebral fractures, 35 of them (49.3%) suffered multiple fractures. Thoracic vertebrae were the most frequently affected (n=82, 63%). The most frequent localization was T4 toT8 (n=50, 38.5% and T11 to L2 (n=41, 31.5%). Age ranged between 12 and 15 years (n=35, 49.3%), with only 5 patients under 6 years. 90.9% of the patients with lumbar fractures were older than 8 years and 76.9% of the patients with cervical fractures were over 8 years. Motor vehicle accident was the most common cause in our series (n=20, 23.3%). 81% of these patients did not use safety belt. Ten children with cervical injuries were seen by medical staff at the prehospital stage, and only 4 of them arrived to Hospital with cervical collar. There were thirty five patients with thoracic or lumbar injuries but only 27 of them were transferred to our Institution by ambulance. Surgery was required in 2 patients, both of them with unstable fractures. Mean hospital stay was 17,1 days (range 2-37 days).

CONCLUSIONS

Group gender distribution is similar between males and females and the incidence in our series is higher than other series of the literature. Thoracic injuries are the most frequent. It is necessary to improve prehospital management of these patients and to increase the use of safety belt. Spine injury incidence increased with age.

[Evidence-based medicine in Spanish pediatric surgery reports]

INTRODUCTION

Pediatric surgical literature is characterized by a high prevalence of observational studies and a paucity of randomized controlled trial, comparing mainly medical therapies.

AIMS

To asses scientific evidence level produced by spanish pediatric surgeons.

MATERIAL AND METHODS

Articles reported in Cirugía Pediátrica, surgical reports in Anales Españoles de Pediatría, and reports from spanish authors published in the Journal of Pediatric Surgery, Pediatric Surgery International and European Journal of Pediatric Surgery, from 1997 to 2002. Internal validity was assessed through the critial guides from Sackett, and evidence level was classified through the Oxford Centre for Evidence Based Medicine classification.

RESULTS

94.5% on therapy reports, 61.5% on diagnosis, 83.3% on prognosis and 52.2% on risk factors or etiology, were classified as level 4 (descriptive studies). Only four randomized controlled trials were found, all of them comparing medical therapies (analgesia, antibiotics and surgical stress control).

CONCLUSIONS

Our results are similar to those offered by previous reviews, showing up a low level of scientific evidence in most articles. Diffusion of guides on reporting descriptive studies may improve the evidence level of our reports.

Safety Assessment of the Conversion From Mycophenolate Mofetil to Enteric-Coated Mycophenolate Sodium in Stable Renal Transplant Recipients

The immunosuppressant mycophenolate mofetil (MMF; CellCept) has greatly improved transplant recipients' clinical outcomes, but its efficacy may be limited by dose adjustments due to adverse events (AEs). An enteric-coated formulation of mycophenolate sodium (EC-MPS; myfortic), designed to improve gastrointestinal tolerability is now available. This Latin-American, prospective, multicenter, open-label, 6-month trial assessed the safety and tolerability of converting renal transplant recipients from MMF to EC-MPS. In total, 237 renal transplant recipients (stable > or = 3 months' posttransplant) receiving MMF (< or =1000 mg b.i.d.) were enrolled. Adults (n = 218) were converted to EC-MPS 720 mg b.i.d. (equimolar to MMF 1000 mg b.i.d.) even if they were initially receiving <1000 mg MMF b.i.d. (ie, 47 adults received a higher than equimolar dose of EC-MPS). Children (n = 19) were converted to EC-MPS 450 or 432 mg/m2 b.i.d. Patients also received cyclosporine microemulsion (Neoral) and corticosteroids. There were three acute rejections and no graft failures. The incidence of AEs was 59.9% (in those receiving a higher than equimolar EC-MPS dose it was 57.4%). In all, 22% of patients had gastrointestinal AEs, 37% had infections, and 4.8% had hematological AEs. Only 24 patients (10%) had an AE-related dose reduction. Seven of these patients had received higher than equimolar doses of EC-MPS. Patients can be safely converted from different doses of MMF to a standard dose of EC-MPS. The requirement for EC-MPS dose reduction to manage AEs was relatively low. Use of EC-MPS is a valid alternative for renal transplant recipients receiving maintenance MMF treatment.

Paediatric trauma in Spain: a report from the HUGM Trauma Registry

OBJECTIVES

To analyse the characteristics of the infant population suffering trauma in our setting. To evaluate the importance of the different aetiological mechanisms. To study the pre- and intra-hospital management of these children. To describe the relative significance of the different lesions. To establish the magnitude of paediatric trauma as a social problem in terms of morbidity and mortality.

MATERIAL AND METHODS

From January 1995 to April 2002, a total of 2633 children admitted to our Centre (Hospital Universitario Gregorio Maranon) after suffering some type of injury were included in our Trauma Register. 108 variables have been analysed, including the identification of the patient, type, site and mechanism of the accident, pre-hospital care, transport, complete evaluation on admission, indices of injury severity, diagnostic tests, lesions, treatments performed and morbidity and mortality.

RESULTS

The accidents were more frequent in boys than in girls (68.5 % versus 31.5 %). The predominant age group was the 12 - 15 year old group (36.8 %). There was a higher frequency of accidents in the street (37.2 %) than at home (19.4 %) or at school (13.8 %). The most frequent mechanism was a fall (35.6 %), followed by road traffic accidents (23.7 %). On admission, 14.7 % of the children had a Paediatric Trauma Score (P.T.S.) < or = 8 (n = 388). 3.8 % were considered severe multiple trauma patients, presenting an Injury Severity Score (I.S.S.) > or = 15 (n = 101). 4.2 % of the children required intensive care. The most frequent lesions were those of the locomotor system (58.1 %) and head injuries (34.9 %). Some type of surgical or orthopaedic procedure was performed under general anaesthesia in 1522 patients (57.8 %). The mean length of stay was 4.4 days (range 1 - 214 days). Sequelae of some form were detected in 36.4 % of the patients over 3 years of age. The total mortality was 0.5 % (n = 13), being 12.8 % in the group of patients with an I.S.S. > or = 15.

CONCLUSIONS

Analysis of the data in our Registry has helped us to define the characteristics of the paediatric trauma population in our setting, to monitor the management of trauma in the different care levels and to develop prevention programmes. It has also enabled us to compare the results with those of other centres in terms of morbidity and mortality with the aim of identifying and correcting any possible deficiencies in the care system.

Anaphylaxis caused by cauliflower

BACKGROUND

Cauliflower is a vegetable belonging to the family Cruciferae, genus Brassica, var. Botrytis.

METHODS

We report the case of a 70 year-old man who suffered an acute episode consisting of oropharyngeal itching, facial and hand swelling, dyspnea and severe bronchospasm within a few minutes after eating vegetable paella containing cauliflower, green beans, red and green pepper. Due to the severity of the reaction he needed treatment in the emergency room.

RESULTS

Skin prick tests with common aeroallergens were positive to Cupressus, Platanus and grass pollen. A strong skin prick test response was obtained with cauliflower and peach lipid transfer protein. Skin prick test with rice, green beans and pepper were negative. Specific IgE determinations were positive to cabbage and cauliflower, and negative to mustard.

CONCLUSIONS

The clinical history and the results of the allergologic work-up point out to this patient having experienced an IgE-mediated anaphylactic reaction to cauliflower. To the best of our knowledge, this is the first case report of anaphylaxis due to cauliflower.

[Use of oral anticholinergic therapy in children under 1 years of age with high risk bladder]

THE AIM

To assess the effectiveness and safety of the treatment with oral anticholinergic agents (Oxybutin clorure) in patients under 1 year old, and who aree carriers of high risk bladder secondary to neurological illness as well as no neurological one.

MATERIAL AND METHODS

Since 1989, we have indicated treatment with anticholinergic agents to 16 patients: 9 patients had neurogenic bladder secondary to: myelomeningocele (n=7) and sacrocoxigeal teratoma (n=2). Others 7 patients had non neurogenic bladder secondary to: posterior urethral valvulas (n=1), valvula-like syndrome (n=4), post-surgery of neonatal giant bladder diverticulum (n=1) and Prune-Belly syndrome (n=1). The urodinamic study was performed during the first six months of life, being "high risk bladder" defined according to the parameters of compliance vesical and pressure of leak at point (PER). Five of the patients showed neonatal cronic renal failure (CRF), who were treated by cutaneus temporary derivation. All patients at treatment with anticholinergic agents at a 0.2 mg/kg/day dose was established; other early adjunctive treatment prior to the closure of the urinary derivation in children with CRF(n=5); or as a part of the conservative treatment (n=3), alone or associate to intermittent bladder catheterization (IBC) (n=8). During the treatment with anticholinergic agents, the cardiac frequency was controlled by EKG registration in 6 patients, being the rest of the children clinicaly controled (skin colour, mouth dryness, cardiac frequency and intestinal function).

RESULTS

In all the cases, the minimum duration of the treatment was one year, until the functional stabilization of the urinary tract. It is to underline the absence of secondary complications which would have caused the suspension or the reduction of the treatment at long term. Conventional studies of urologicals image and urodinamic studies, showed the stabilization of the urinary tract and also the preservation of kidney function and not only was demonstrated in those patients with oral anticholinergic agent as their unique treatment, but also in those patients who had previously been derivated. The previous vesical stabilization allowed the optimum result of subsequent corrective surgeries in five patients (ureteroneocystostomy and vesiscotomy clousure. In cases with previous derivation, the treatment with oral anticholinergic agents made easier vesicostomic clousure in the forth quarter of the first year old wih the maintenance of the vesical stability.

CONCLUSIONS

The use of oral anticholinergic agents at a dose of 0.2 mg/kg/day, has resulted to be safe as well as effective in the treatment of high risk bladder in infancy those with less than one year of life. In those patients with serious dysplasia by reflux, it contributes to the preservation of kidney function, it makes easier the early desderivation and it also stabilizes in a functional way the bladder as a previous step to subsequent reconstructive surgeries.

Electronic, thermal and mechanical properties of carbon nanotubes

A review of the electronic, thermal and mechanical properties of nanotubes is presented, with particular reference to properties that differ from those of the bulk counterparts and to potential applications that might result from the special structure and properties of nanotubes. Both experimental and theoretical aspects of these topics are reviewed.