Simulation of thermal sanitization of air with heat recovery as applied to airborne pathogen deactivation.

The technique of air sterilization by thermal effect was revisited in this work. The impact of incorporating a high efficiency heat recovery exchanger to a sterilizing cell was especially assessed. A mathematical model was developed to study the dynamics and the steady state of the sterilizer. Computer simulation and reported data of thermal inactivation of pathogens permitted obtaining results for a proof-of-concept. The simulation results confirmed that the incorporation of a heat recovery exchanger permits saving more than 90% of the energy needed to heat the air to the temperature necessary for sterilization, i.e., sterilization without heat recovery consumes 10-20 times the energy of the same sterilization device with heat recovery. Sanitization temperature is the main process variable for sanitization, a fact related to the activated nature of the thermal inactivation of viruses and bacteria. Heat recovery efficiency was a strong function of the heat transfer parameters but also rather insensitive to the cell temperature. The heat transfer area determined the maximum capacity of the sterilizer (maximum air flowrate) given the restrictions of minimum sanitization efficiency and maximum power consumption. The proposed thermal sterilization device has important advantages of robustness and simplicity over other commercial sterilization devices, needing practically no maintenance and eliminating a big variety of microorganisms to any desired degree. For most pathogens, the inactivation can be total. This result is not affected by the uncertainties in thermal inactivation data, due to the Arrhenius-like dependence of inactivation. Temperature can be adjusted to achieve any removal degree.

3D-printing-assisted fabrication of chitosan scaffolds from different sources and cross-linkers for dental tissue engineering.

The aim of the present study was to fabricate and characterise chitosan scaffolds from animal and fungal sources, with or without gelatine as a co-polymer, and cross-linked to 3-glycidyloxyproply trimethoxysilane (GPTMS) or genipin for application in dental root tissue engineering. Chitosan-based scaffolds were prepared by the emulsion freeze-drying technique. Scanning electron microscopy (SEM) and nano-focus computed tomography (nano-CT) were used to characterise scaffold microstructure. Chemical composition and cross-linking were evaluated by Fourier transform infrared-attenuated total reflectance spectroscopy. Compression tests were performed to evaluate scaffold mechanical properties. Scaffold degradation was evaluated by gravimetric method and SEM. Scaffold bioactivity immersed in simulated body fluid was evaluated by SEM, with associated electron dispersive X-ray spectroscopy, and apatite formation was examined by X-ray diffraction. Finally, human dental pulp stem cells (hDPSCs) viability was evaluated. The fabrication method used was successful in producing scaffolds with organised porosity. Chitosan source (animal vs. fungal), co-polymerisation with gelatine and cross-linking using GPTMS or genipin had a significant effect on scaffold properties and hDPSCs response. Chitosan-genipin (CS-GEN) scaffolds had the largest pore diameter, while the chitosan-gelatine-GPTMS (CS-GEL-GPTMS) scaffolds had the smallest. Animal chitosan-gelatine co-polymerisation increased scaffold compressive strength, while fungal chitosan scaffolds (fCS-GEL-GPTMS) had the fastest degradation rate, losing 80 % of their weight by day 21. Gelatine co-polymerisation and GPTMS cross-linking enhanced chitosan scaffolds bioactivity through the formation of an apatite layer as well as improved hDPSCs attachment and viability. Tailored chitosan scaffolds with tuned properties and favourable hDPSCs response can be obtained for regenerative dentistry applications.

Blood-Brain Barrier in a Haemophilus influenzae Type a In Vitro Infection: Role of Adenosine Receptors A2A and A2B.

The blood-brain barrier (BBB) is mainly made up of tightly connected microvascular endothelial cells (BMECs), surrounded by pericytes (BMPCs) which regulate BBB tightness by providing soluble factors that control endothelial proliferation. Haemophilus influenzae type a (Hia) is able to reach the BBB, crossing it, thus causing meningitis. In this study, by using an in vitro model of BBB, performed with human BMECs and human BMPCs in co-culture, we demonstrated that, after Hia infection, the number of hBMPCs decreased whereas the number of hBMECs increased in comparison with non-infected cells. SEM and TEM images showed that Hia was able to enter hBMECs and reduce TEER and VE-cadherin expression. When the cells were infected in presence of SCH58261 and PSB603 but not DPCPX, an increase in TEER values was observed thus demonstrating that A2A and A2B adenosine receptors play a key role in BBB dysfunction. These results were confirmed by the use of adenosine receptor agonists CGS21680, CCPA, and NECA. In infected co-cultures cAMP and VEGF increased and TEER reduction was counter-balanced by VEGF-R1 or VEGF-R2 antibodies. Moreover, the phosphorylated CREB and Rho-A significantly increased in infected hBMECs and hBMPCs and the presence of SCH58261 and PSB603 significantly abrogated the phosphorylation. In conclusion, this study demonstrated that the infection stimulated A2A and A2B adenosine receptors in hBMECs and hBMPCs thus inducing the pericytes to release large amounts of VEGF. The latter could be responsible for both, pericyte detachment and endothelial cell proliferation, thus provoking BBB impairment.

Intestinal obstruction secondary to endometriosis: a rare case of synchronous bowel localization.

Although endometriosis is a common disease in women of childbearing age, intestinal endometriosis is unusual and may cause clinically significant complications. We report a 35-year-old woman with endometriosis involving the ileocaecal junction and rectum who presented with intestinal obstruction. She was operated with a preoperative diagnosis of malignancy. The diagnosis of endometriosis was made only after histological examination of the resected specimen. Intestinal endometriosis has a diverse clinical spectrum, with nonspecific features in many patients. In female patients who have unexplained digestive complaints, endometriosis should also be considered in the differential diagnosis.

Clastogenicity and aneuploidy in newborn and adult mice exposed to 50 Hz magnetic fields.

PURPOSE: To detect possible clastogenic and aneugenic properties of a 50 Hz, 650 muT magnetic field. MATERIALS AND METHODS: The micronucleus test with CREST (Calcinosis, Raynaud's phenomenon, Esophageal dismotility, Sclerodactility, Telangectasia) antibody staining was performed on liver and peripheral blood sampled from newborn mice exposed to an ELF (Extremely Low Frequency) magnetic field during the whole intra-uterine life (21 days), and on bone marrow and peripheral blood sampled from adult mice exposed to the same magnetic field for the same period. RESULTS: Data obtained in newborn mice show a significant increase in micronuclei frequencies. In absolute terms, most of the induced micronuclei were CREST-negative (i.e., formed by a chromosome fragment). However, in relative terms, ELF exposure caused a two-fold increase in CREST-negative micronuclei and a four-fold increase in CREST-positive micronuclei (i.e., formed by a whole chromosome). No significant effect was recorded on exposed adults. CONCLUSIONS: These findings suggest the need for investigation of aneugenic properties of ELF magnetic fields in order to establish a possible relationship to carcinogenesis.

PARKSERVICE: Home support and walking aid for people with Parkinson's disease.

PARKSERVICE is a telemedical application currently being validated in the EU. The objectives are to provide a combination of home clinical and social support for people with Parkinson's disease with a revolutionary walking aid that uses "visual cues" to enable improved mobility. Early results are presented and the outlook of home telemedicine and visual cueing for people with PD is discussed.

Role of early ultrasound in detecting inflammatory intestinal disorders and identifying their anatomical location within the bowel.

BACKGROUND: Although bowel ultrasound is a widely accepted diagnostic tool in bowel diseases, its value as the primary imaging procedure in patients with symptoms/signs suggestive of inflammatory bowel disorders is still unclear. AIM: To investigate the accuracy of bowel ultrasound compared with barium X-ray studies, computed tomography, endoscopy and bowel surgery in the initial assessment of inflammatory bowel disorders. METHODS: Four hundred and eighty-seven patients hospitalized consecutively for symptoms or signs suggestive of a bowel disorder between December 1999 and March 2002 were initially enrolled in the study. All patients underwent bowel ultrasound as the first imaging procedure within 36 h of admission; radiographic evaluations, endoscopy and/or surgery were then performed as appropriate and the results of these investigations were used as the gold standard. RESULTS: Three hundred and thirty-six patients had pathological findings of the bowel detectable at ultrasound as the final diagnosis. The main organic disorders found were Crohn's disease (56%), ulcerative/indeterminate colitis (30%), bowel tumours (5%), appendicitis/diverticulitis (2%) and other inflammatory conditions (8%). The overall sensitivity and specificity of bowel ultrasound were 85% and 95%, respectively, whereas the positive and negative predictive values were 98% and 75%, respectively. Comparisons of ultrasound with X-ray or endoscopic results by disease localization showed that the diagnostic performance of ultrasound was higher for inflammatory conditions of the ileum and sigmoid/descending colon (sensitivity of 92% and 87%, respectively), whereas abnormalities localized in the rectum, duodenum and proximal jejunum were often missed by ultrasound. CONCLUSIONS: In expert hands, bowel ultrasound is highly predictive of inflammatory disease localized in the ileum or colon, and may well be used as the primary imaging method when Crohn's disease or ulcerative colitis is suspected on a clinical basis.

Small bowel stenosis in Crohn's disease: clinical, biochemical and ultrasonographic evaluation of histological features.

AIM: To establish whether intestinal ultrasound, clinical or biochemical indices of activity can assess histological features of ileal stenosis in Crohn's disease. METHODS: In 43 patients undergoing surgery for a single ileal stenosis, clinical and biochemical parameters, as well as intestinal ultrasound, were assessed prior to surgery. The echo pattern of thickened bowel segments at the site of stenosis was classified as hypoechoic, stratified or mixed (segments with/without stratification). During surgery, stenoses were identified, resected and then histologically examined using standardized criteria. RESULTS: Clinical and biochemical indices of activity showed an overall weak positive correlation with histological inflammatory parameters and a negative correlation with fibrosis. The intestinal ultrasound echo pattern at the stenosis site was stratified in 25 patients, hypoechoic in 14 and mixed in four. Stenoses characterized by a stratified echo pattern showed a significantly higher degree of fibrosis, those characterized by hypoechoic echo pattern showed a higher degree of inflammation, while stenoses with a mixed echo pattern showed high degrees of both fibrosis and inflammation. CONCLUSION: Ultrasound and, to a lesser degree, clinical and laboratory indices discriminate between inflammatory and fibrotic ileal stenoses complicating Crohn's disease, thus allowing appropriate medical and/or surgical treatment to be defined.

Sexual dimorphism of GABAA receptor levels in subcortical brain regions of a woodland rodent (Apodemus sylvaticus).

This is the first report of quantitative autoradiography results showing sex differences of GABAA receptor levels in brain regions of a wild rodent (wood mouse, Apodemus sylvaticus) living in its natural habitat. The labeling of this GABAergic site with its specific high affinity radioligand [3H] muscimol provided a heterogeneous and dimorphic binding pattern in some of the neural centers. In the female, higher (> or = 50 < or = 65%) to moderately higher (< 50%) binding levels than in the male, even after correction of the specific binding values using the calculated quenching coefficients, were observed in the substantia nigra pars reticulata and ventral lateral thalamic nucleus, brain centers that are relays of motor circuits. In the male, on the other hand, a higher level was only obtained in the caudateputamen. Relays of the stria terminalis-hypothalamic-central gray pathway such as the bed nucleus of the stria terminalis, the pontine central gray and the ventromedial hypothalamic nucleus, were among the other female brain areas with an extremely higher (> 65%) to higher and moderately higher binding activity than in the male. From the saturation analyses, it appeared that the binding differences were mainly due to Bmax variations, although closer examinations revealed that changes in the KD might have also accounted for [3H] muscimol binding differences, as shown by the high KD and Bmax values in the bed nucleus of the stria terminalis, the substantia nigra pars reticulata and the pontine central gray of the female wood mouse. These findings suggest that the dimorphic binding activity of GABAA receptors in the above brain regions might be involved in neuronal circuitry mechanisms related to sex-specific social behaviors in rodents living in their natural environmental conditions.

Environmental impact of the Chernobyl accident: mutagenesis in bank voles from Sweden.

An investigation was carried out in Sweden aimed at studying the possible genetic effects of the Chernobyl fallout on wild small mammals. The bank voles (Clethrionomys glareolus Schreb.) were obtained from three differently contaminated areas in Sweden and, for control, in an area with negligible contamination by fallout. Radionuclide determinations to assess the content of 137Cs and mutagenicity tests (bone marrow micronucleus test and sperm abnormality assay) were performed. The results obtained showed a positive correlation between the increase of micronucleated polychromatic erythrocytes (MPCE/1000 PCE) and both 137Cs content in muscle and in soil contamination. The estimated doses absorbed by the animals were far lower than those required for the same effect in laboratory experiments. An explanation of this discrepancy between dose and measured biological effect is not available, yet similar results have been repeatedly reported after the Chernobyl accident and should be a matter for further discussion. An increased frequency of micronucleated cells might occur at minimal dose gradients, and the micronucleus test appears to be a valid tool to show such effects.

Long-term results and multivariate analysis of prognostic factors in 138 consecutive patients operated on for Crohn's disease using "bowel-sparing" techniques.

BACKGROUND: Conservative surgery has become accepted as a useful option for the surgical treatment of complicated Crohn's disease (CD). METHODS: One hundred thirty-eight consecutive patients treated with strictureplasty or miniresections for complicated CD have been observed prospectively. The possible influence of a number of variables on the risk of recurrence was investigated using the Cox proportional hazard model, and a time-to-event analysis was made using the Kaplan-Meier function. RESULTS: There was no perioperative mortality; the morbidity rate was 5.7%. A close correlation was found between the risk of recurrence and the time between diagnosis and first surgery. The overall 5-year recurrence rate was 24%, being 36% in the patients requiring surgery within 1 year of diagnosis and 14% in those operated on more than 1 year after diagnosis. CONCLUSIONS: Risk factor analysis highlighted a group of patients at high risk of surgical recurrence. Given that our results are similar to those reported in other series, we consider strictureplasty and miniresections safe and effective procedures for the treatment of complicated CD.

Description of new "bowel-sparing" techniques for long strictures of Crohn's disease.

In the period of January 1993 to December 1995 we operated on 55 patients with various complications of Crohn's disease. In properly selected cases, obstructive complications of Crohn's disease can be treated effectively by strictureplasty. Long strictures, even if a narrow lumen is still present, are commonly managed by resection, as classic strictureplasties cannot be done; also Finney strictureplasty seems inadequate, as it creates a blind loop that favors bacterial overgrowth and fecal stasis. Three original "sparing bowel" surgical approaches are proposed as possible alternative in the treatment of long stricture in Crohn's disease. We perform side-to-side ileoileal plasty whenever we are faced with severe narrowing of a long segment of small bowel (>10 cm); side-to-side ileocolic plasty whenever very severe disease with narrowing of ileocaecal valve is present; and ileocaecal plasty when terminal ileitis involves the very distal end of the small bowel, but sparing or only minimally affecting the ileocaecal valve. The above-mentioned procedures are described in detail and the clinical outcomes related to the first 8-patient series of our institution are presented.

Oxidative stress, vitamin A and vitamin E behaviour in patients submitted to conservative surgery for complicated Crohn's disease.

AIMS: To assess whether plasma peroxidation and plasma levels of antioxidant compounds are correlated with clinical and biochemical activity in complicated Crohn's disease patients, and to evaluate whether the relief of obstructive complication by conservative surgery has any effect on the oxidative stress. PATIENTS AND METHODS: From May 1998 to May 2000, 20 Crohn's disease patients were studied. Basal peroxidative state (basal thiobarbituric acid reactive substances), peroxidative state after stimulation with copper sulfate (stimulated thiobarbituric acid reactive substances], lag time of plasma peroxidation susceptibility, plasma levels of vitamin E and A, C reactive protein, erythrocyte sedimentation rate and Crohn's disease activity index, were determined, before surgery, then 2 months and 1 year after surgery. A group of 134 healthy volunteers were used as controls. All patients were treated by conservative surgical procedures (i.e., strictureplasty and/or minimal resections). Student t test for paired and unpaired data and Spearman R correlation coefficient were calculated. RESULTS: Peroxidative plasma levels, as well as inflammatory indices, are significantly reduced 2 months and 1 year after surgery (p < 0.005), but basal levels of peroxidation and antioxidant scavengers seem to be disregulated in Crohn's disease patients compared to those in controls (p < 0.005). A correlation was found between basal thiobarbituric acid reactive substances, lag-time and erythrocyte sedimentation rate (R:0.51; p < 0.05. R:0.56; p < 0.05) and C reactive protein (R:0. 6; p < 0.005. R:0. 65; p < 0.005). CONCLUSIONS: An imbalance between pro- and antioxidant mechanisms, due to chronic gut inflammation, is present in complicated Crohn's disease, and an excess of lipid peroxidation is probably an important pathogenetic factor Conservative surgery can reduce the oxidative stress avoiding repeated or extended resections that could lead to intestinal malabsorption and short bowel syndrome.

Small mammals as biological indicators of radioactive contamination of the environment.

An investigation was carried out in Sweden aimed at studying the contamination of small mammals (orders Rodentia and Insectivora) following the Chernobyl accident. The animals were captured in three differently contaminated areas in Sweden and, for control, in an area with negligible fallout. The results obtained show that the activity in the captured animals was correlated with surface deposition. The differences between the species investigated and the influence of feeding habits on the contamination levels are discussed.

Genetic damage in urban mice exposed to traffic pollution.

Wild rodents (Mus domesticus) were collected in three areas in Rome exposed to different traffic flows to ascertain a possible correlation between genetic damage and heavy metal concentration. The concentration of lead, cadmium and zinc were determined in liver, kidney and bones and two mutagenicity tests (micronucleus test and sperm abnormality assay) were employed. The results obtained showed that the contents of lead and cadmium were higher in animals collected in areas with high traffic flows than in those from control areas. A statistically significant increase of the frequency of micronucleated erythrocytes and of abnormal sperm cells was also obtained in animals collected in sites with high traffic flows. The investigation confirmed the suitability of using wild rodents as bioindicators of environmental pollution and as key-organisms in programs of pollution monitoring and environmental conservation.

137Cs determination and mutagenicity tests in wild Mus musculus domesticus before and after the Chernobyl accident.

Wild rodents were collected alive in a suburban area to the north of Rome before, during, 6 months and 1 year after the Chernobyl accident. Radionuclide determinations to assess their content of (137)Cs and mutagenicity tests (bone-marrow micronucleus test and sperm abnormalities assay) were performed on the captured animals. The results obtained for the species Mus musculus domesticus (which was the rodent captured in highest numbers), compared with the results obtained before the fallout, showed an increase of both micronucleated polychromatic erythrocytes (MPCEs/1000 PCEs) and (137)Cs content during and after the fallout.

Genotoxic damage in free-living Algerian mouse (Mus spretus) after the Coto Doñana ecological disaster.

The Doñana National Park (Spain), one of the most important wildlife sites in the West of Europe, was affected (25 April 1998) by the spill of acidic waste rich in toxic metals (mainly zinc, lead, copper, etc.), arsenic and aromatic amines from the Aznalcollar mine accident. Micronuclei test with May Grunwald-Giemsa and with CREST-antikinetocore staining using DAPI as counter-staining were performed on peripheral blood erythrocytes from Algerian mice to evaluate genotoxic damage. Animals were collected in four locations each differently affected by the disaster. Higher frequencies of micronuclei and CREST-positive micronuclei were observed in the sites, which were reached by toxic sludge and contaminated water in comparison with those located within the park. The results obtained applying the two methods indicate that DAPI staining is more sensitive in detecting micronuclei. Genotoxic biomonitoring should be further carried out in the area to control the mutagenetic level in natural populations.

Carcinoma of the head of the pancreas: review of 67 cases and comparison with 27 additional periampullary carcinomas.

BACKGROUND/AIMS: Carcinoma of the head of the pancreas is reported with increasing incidence. The classical Whipple procedure, modified by Traverso and Longmire, is a major surgical undertaking and there is question on its indication in the case of lesions which, although technically resectable, are not susceptible to cure. PATIENTS AND METHODS: We review 67 cases of carcinoma of the head of the pancreas comparing the results of radical vs. palliative surgery. The results were then compared with 27 additional cases of periampullary carcinomas. RESULTS: Long term survival was obviously higher after resection, due to the more advanced tumor stage in the palliation group. However, perioperative mortality, supposedly high in extensive resective surgery, was 8.7% (vs 11.9% in the palliation group). CONCLUSIONS: At present, extensive resective surgery carries unacceptable incidence of perioperative mortality. Therefore we suggest that indication for resection should be widened, as it may offer better chances of cure in resectable periampullary carcinomas and, even in non curable cases, it offers better quality of life and the advantages of tumor debulking.

Third segment cholangio-jejunostomy in the treatment of unresectable klatskin tumors.

BACKGROUND/AIMS: Cholangiocarcinoma of the hepatic hilum is a seldom curable lesion when detected and several methods of palliation have been suggested. Bismuth has proposed an intrahepatic cholangiojejunostomy on the third segment of the liver, which in his experience obtains effective biliary drainage with better quality of life compared with other forms of palliation. PATIENTS AND MATERIALS: We have used this technique in nine cases. We evaluate results, mortality and morbidity, in comparison with other authors' reported series. RESULTS: In the early postoperative period one patient died, two patients suffered from immediate postoperative complications, and jaundice resolved completely in six patients. Long term survival was influenced by the underlying disease. CONCLUSION: Our findings support Bismuth preference for this technique of surgical palliation for non resectable tumors of the biliary tract.

Surgical treatment of pancreatic tumors invading the spleno-mesenteric-portal vessels. An Italian Multicenter Survey.

BACKGROUND/AIMS: The authors are interested in determining the diagnostic and surgical approach followed in different Italian institutions in the treatment of adenocarcinoma of the head of the pancreas, whenever the spleno-mesenteric-portal confluence is invaded. METHODOLOGY: A 10-item questionnaire was sent to 21 Italian Centers of Surgical Oncology and a total of 1185 patients treated with pancreaticoduodenectomy were collected from 15 centers. Among them, 164 spleno-mesenteric-portal vein (SMPV) resections were performed. RESULTS: In all collaborative centers, the diagnostic work-up is comparable with what is reported in the literature. An accurate pre- and intra-operative staging and a differential diagnosis between inflammatory and neoplastic involvement of the vessel walls is universally considered essential for its surgical and oncological implications. If vessel involvement is ruled out, 7 centers proceed to pancreasectomy anyway. Direct end-to-end vein reconstruction is used as the primary procedure, but interposition of PTFE and autologous vein grafting may be used. An overall 4.8% post-operative complications only have been reported. Mean perioperative mortality reported is 3.8% (0-11.5%) and morbidity is 22.8% (4.7-57%). Survival rate is 10 months overall. The mean actuarial 5-year survival is 12%. CONCLUSIONS: The attitude of the collaborative centers in cases of SMPV involvement varies, with a slight majority favoring a conservative behavior. Surgical resection extended to the vessels is still uncommon, even in centers mostly experienced in surgery of the pancreas. We believe that vascular resections can be safely performed in both of the different conditions: localized tumors locally invading the vessels and neoplasms with massive invasion of the peripancreatic structures. We share with others the opinion that, in experienced centers, extensive resections should have a role for palliation of carcinoma of the pancreas whenever they offer a better quality of life, although life expectancy may not be positively influenced.