New ventilation design criteria for energy sustainability and indoor air quality in a post Covid-19 scenario.

The Covid-19 outbreak raised great attention to the importance of indoor air quality in buildings. Even if the Covid-19 epidemic is nearing an end, all stakeholders agree that increasing outside air flow rates is beneficial for decreasing the likelihood of contagion, lowering the risk of future pandemics, and enhancing the general safety of the interior environment. Indeed, diverse concerns raised about whether the ventilation standards in place are still adequate. In this context, this research intends to assess the suitability of current ventilation standards in addressing the current pandemic scenario and to offer novel criteria and guidelines for the design and operation of HVAC systems, as well as useful guidance for the creation of future ventilation standards in a post-Covid-19 scenario. To that end, a comprehensive analysis of the ANSI/ASHRAE 62.1 is carried out, with an emphasis on its effectiveness in reducing the risk of infection. Furthermore, the efficacy of various ventilation strategies in reducing the likelihood of contagion has been investigated. Finally, because building ventilation is inextricably linked to energy consumption, the energy and economic implications of the proposed enhancements have been assessed. To carry out the described analysis, a novel method was developed that combines Building Energy Modelling (BEM) and virus contagion risk assessment. The analyses conducted produced interesting insights and criteria for ventilation system design and operation, as well as recommendations for the development of future standards.

Pathological implications of Th1/Th2 cytokine genetic variants in Behçet's disease: Data from a pilot study in a Sicilian population.

Cytokines act as pleiotropic polypeptides able to regulate inflammatory/immune responses and to provide important signals in physiological and pathological processes. Several cytokines (Th1, Th2, and Th17) seem to be involved in the pathophysiology of Behçet's disease, a chronic immune-mediated disease characterized by oral and genital lesions and ocular inflammation. Its individual susceptibility seems to be modulated by genetic variants in genes codifying these cytokines. Th1 and Th17 seem to be involved in the disease's active phases, and Th2 seems to affect the development or severity of the disease; however, contrasting data are reported. In this study, some genetic variants of the Th1/Th2 cytokine genes were investigated in Sicilian patients and age- and gender-matched controls. Three very significant associations with Behçet's disease were detected, and combined genotypes associated with increased disease risk were identified. Results obtained point to the key role of Th1/Th2 cytokine genetic variants in disease susceptibility.

Quantitative shape analysis of chemoresistant colon cancer cells: correlation between morphotype and phenotype.

Morphological, qualitative observations allow pathologists to correlate the shape the cells acquire with the progressive, underlying neoplastic transformation they are experienced. Cell morphology, indeed, roughly scales with malignancy. A quantitative parameter for characterizing complex irregular structures is the Normalized Bending Energy (NBE). NBE provides a global feature for shape characterization correspondent to the amount of energy needed to transform the specific shape under analysis into its lowest energy state. We hypothesized that a chemotherapy resistant cancer cell line would experience a significant change in its shape, and that such a modification might be quantified by means of NBE parameterization. We checked out the usefulness of a mathematical algorithm to distinguish wild and 5-fluorouracil (5-FU)-resistant colon cancer HCT-8 cells (HCT-8FUres). NBE values, as well as cellular and molecular parameters, were recorded in both cell populations. Results demonstrated that acquisition of drug resistance is accompanied by statistically significant morphological changes in cell membrane, as well as in biological parameters. Namely, NBE increased progressively meanwhile cells become more resistant to increasing 5-FU concentrations. These data indicate how tight the relationships between morphology and phenotype is, and they support the idea to follow a cell transition toward a drug-resistant phenotype by means of morphological monitoring.

Concentrations of cytokines IL-6 and IL-10 in plasma of burn patients: their relationship to sepsis and outcome.

Burn injury induces a suppression of the Th1 response, which is associated with an increased susceptibility to conditions of infection, morbidity, and mortality. It is well established that cytokines modulate the pathogenesis of burn injury. In this study, plasma levels of interleukin-6 (IL-6) and interleukin-10 (IL-10) were determined in burn patients and correlated with the severity of sepsis. Sixty adult burn patients (total body surface area burned, 8-80%) were included in the study, of whom 34 developed sepsis and 14 died. The nonseptic group consisted of 26 patients. Thirty-one healthy blood donors served as controls. Patients were not treated with antibiotics until sepsis occurred. Plasma samples were collected immediately post-burn and after several days, and cytokine concentrations were determined by ELISA. Within three days, all the patients presented high levels of circulating IL-6, which were significantly higher in septic patients than in nonseptic patients (349 ± 278 vs 63 ± 56 pg/ml, p < 0.001).IL-10 levels were higher in septic patients than in nonseptic patients at all times in our study. The value of 60 pg/ml shows a sensitivity of 92% and a specificity of 93% in the differentiation of survivor from nonsurvivor septic patients. In this study the high value of circulating IL-10 on day 3 suggests that cytokine may discriminate between nonsurvivor septic and survivor septic patients.

Evaluation of an accident and emergency teleconsultation service for north-east Scotland.

We evaluated an accident and emergency teleconsultation service provided to 14 community hospitals in north-east Scotland. Each community hospital was equipped with a videoconferencing system and a document camera to allow transmission of radiographs. The network used 384 kbit/s ISDN connections. A total of 1392 teleconsultations were recorded during a 12-month study period. Seventy-seven per cent of patients (n = 1072) were managed locally and 23% (n = 320) were transferred to Aberdeen. The majority (95%) of teleconsultations were conducted on weekdays, and 90% of these occurred between the hours of 09:00 and 16:00. The mean delay in contacting a doctor was 9 min and the mean consultation time was 10 min. The majority of patients were suffering from fractures or suspected fractures of the limbs. Radiograph transmission was used in 75% of all teleconsultations. A high degree of satisfaction was recorded by all users of the service.

Minor injuries telemedicine.

A minor injuries telemedicine network in Grampian connects 14 accident and emergency departments in community hospitals to a teaching hospital department. In a six-month study, 407 new telemedicine consultations met the inclusion criteria. Rates of transfer for treatment to the base hospital were used as an outcome measure. Fourteen out of a total of 19 members of medical staff gave telemedical advice. They were mainly middle-grade accident and emergency doctors. Transfer rates were 16-48% (median 29%) across staff. The rates did not seem to be affected by the base doctor's seniority, but were a reflection of that doctor's experience of and confidence in using videoconferencing equipment for clinical purposes. Transfer rates decreased as experience increased. Training for doctors undertaking the provision of specialist advice should include the clinical practicalities of making remote diagnoses.

An evaluation of a telemedicine fracture review clinic.

Telemedicine is being widely used in the treatment of patients with minor injuries in north-east Scotland. A telemedicine fracture review clinic has been developed. During a one-month study period there were a total of 67 review appointments and 88 new patients. Fifty individual patients were reviewed and 10 were seen on more than one occasion. The mean number of reviews for all patients was 2.3. Thirty-six patients had initially been seen by telemedicine, six of whom (17%) had to come to Aberdeen for part of their treatment. Fourteen patients reviewed by telemedicine had initially been seen in person. All patients were safely managed and normal guidelines were followed. There is scope for significant expansion of this service, since 131 patients were seen in a fracture clinic in Aberdeen who lived close to a minor injury unit with telemedicine and X-ray facilities. The majority of these patients were likely to have had injuries suitable to be followed up using telemedicine.

A role for tele-education in the centralization of accident and emergency services.

We evaluated the use of tele-education to provide an induction programme for accident and emergency senior house officers (SHOs) in three remote locations, and compared their performance with that of SHOs receiving the same induction programme in the conventional manner. Both groups of doctors performed similarly in a pre-course multiple-choice question (MCQ) paper, and showed comparable improvement following the induction programme lectures. Sound quality and levels of interactivity were identified as areas for improvement in the tele-education programme. Tele-education might allow doctors based in peripheral units similar access to high-quality teaching to that enjoyed by those in larger hospitals. Further experience and evaluation are required to optimize this method of education delivery.

Community coronary units: strategies to promote pre-hospital thrombolysis.

Early diagnosis and the early delivery of pre-hospital thrombolysis in cases of acute myocardial infarction (AMI) have been shown to decrease mortality. Despite strong evidence of its benefits, pre-hospital thrombolysis rates are still worryingly low. The challenge is to empower community practitioners to deliver thrombolysis. In the Grampian region there is a network of community hospitals which have been equipped with both videoconferencing and remote telemetry equipment. This allows realtime consultation with the local accident and emergency department and coronary care unit. Early trials of the system show that clinical information can be viewed in realtime, with transfer of a 12-lead electrocardiogram at 60 s intervals. This will give general practitioners unprecedented access to specialist advice. Our aim is to use a combination of teaching and decision support technology to ensure that all patients with AMI have the opportunity to access timely and appropriate prehospital thrombolysis.

Air sea rescue, telemedicine style.

Historically, requests from shipping in UK coastal waters for emergency medical advice have been handled on an ad hoc basis by various accident and emergency departments on behalf of the Coastguard. A formal contract to provide this service has recently been established with the Aberdeen Royal Infirmary in Scotland and the Royal Alexandra Hospital in Portsmouth, England. A pre-contract audit showed that the involvement of medical professionals in the evacuation decision improved the quality of triage and intervention. The medical staff at both hospitals received training in giving medical advice and the level of medical knowledge that could reasonably be expected of ships crews. Providing advice to commercial airlines developed from the maritime service. In association with a private company, staff at the Aberdeen Royal Infirmary have developed procedures to support cabin crew and medical professionals on board (initial figures suggest that a medical professional is present on about 45% of flights). At present, although there are insufficient data to draw any firm conclusions, it appears that up to two-thirds of diversions could be avoided using this service.

Can paediatric radiographs be accurately interpreted using an inter-hospital telemedicine system?

Children make up a significant proportion of attendances at accident and emergency departments but there is little published information about the use of telemedicine for viewing paediatric radiographs in the emergency setting. The radiographs and case-notes of 30 children were randomly selected from attendances at an accident and emergency department and were then transmitted over a telemedicine link equipped with a document camera. The doctor recorded the diagnosis and proposed management, along with the confidence in diagnosis and satisfaction with the image. This process was repeated using hardcopy radiographs and a standard viewing box. Five accident and emergency specialists took part in the study; there were in total 300 radiograph viewings. There was one missed fracture out of 75 positive radiographs viewed by telemedicine compared with no missed fractures on direct inspection of the film. Thirteen radiographs viewed over the telemedicine link were thought to be positive or suspicious of injury when the formal report was of no bony injury. The sensitivity of fracture diagnosis using telemedicine was 98.6% compared with 100% on direct inspection of the film, and specificities were 82.6% and 86.6%, respectively. Our study suggests that telemedicine can be used to aid diagnosis and make management decisions in children with minor trauma.

Effect of low frequency, low amplitude magnetic fields on the permeability of cationic liposomes entrapping carbonic anhydrase: II. No evidence for surface enzyme involvement.

Observations recently reported by our group indicate that combined 7 Hz sinusoidal (B(acpeak) = 50 mu T) and parallel static (B(dc) = 50 mu T) magnetic fields can induce a significant increase in diffusion rate of substrate across carbonic anhydrase (CA)-loaded liposomes (DPPC:Chol:SA). A direct involvement of charges of stearylamine (SA) on the lipid membrane surface was also demonstrated. Kinetic studies showed that CA was mainly entrapped in liposomes at 5:3:2 molar ratio, although a small amount (17%) of enzyme was also located on the external surface of these cationic liposomes. In this paper we report steady state kinetic studies on this latter CA after ELF-EMFs exposure. No difference in the apparent K(m) between exposed and sham samples was observed. On the contrary the apparent V(max) was increased by approximately a factor of 2 after field exposure. In spite of the proteolytic digestion of this external CA, a significant increase of enzymatic activity, as a function of increase in the diffusion rate of substrate across the lipid bilayer, was observed in the exposed samples. Based on these results, a conformational change induced by the field on the CA located on the external surface of 5:3:2 liposomes is excluded as an explanation for our previous observations, supporting the primary role of bilayer SA in the interaction with ELF. A model of ELF interaction, based on the Larmor precession theory, explaining the physical phenomenon induced on the dipole of SA has been developed.

[Leishmaniasis in the Porto Ferreira district]. / A leishmaniose no Município de Porto Ferreira.

Since 1981, the incidence of leishmaniasis is increasing in the district of Porto Ferreira, due to favorable environmental conditions for phlebotomini breeding. The data were collected from the Epidemiological Investigation Card and also through interviews with local inhabitants cases. Until the first semester of 1993, forty cases had been recorded and they basically occurred in an area we called critical. The epidemiological features of the disease in the country are different from those listed in literature by the observation that women working at home were more affected, which characterizes an autoctone, domiciliar and urban transmission. The sequence of assistance of patients has also been evaluated, identifying some questions concerning the time elapsed from the first symptoms to the specific treatment. Actions of epidemic-sanitary control were proposed in order to conter the incidence the disease in the district.

Evaluation of tilting disc valves after fatigue life testing: preliminary results within a comparison program.

A fatigue life test, by accelerating the beat rate, simulates several years of virtual life of a prosthetic heart valve in a short period of time. The correlation between the in vivo life of a valve and in vitro testing expectations is as yet not well established, but reproducible test conditions yield precious information about wear and failure. The paper reports a qualitative analysis of mechanical valve wear as part of a comparison program designed to investigate the significance of fatigue testing with the ultimate aim of defining standard guidelines for these type of tests. Two tilting disc valves (29 mm) were subjected to 16 years of fatigue life simulated by means of a Rowan Ash fatigue tester (accelerated rate of 1,200 bpm). Fatigue-induced effects on valve disc and ring surfaces were observed under a monitor microscope to identify wear sites and patterns. A high speed cinematographic system was used to investigate the mechanisms responsible for the wear (wear modes). Valve closure was inspected at a 6,000 frame/s rate. Because of disc rotation during the tilting movement, the points of contact between disc and ring are distributed all around the disc edge but focally on the ring. On both sides of the disc, the surfaces present ring-like concentric grooves. After 16 years of fatigue life the valves showed neither severe wear nor alteration of their fluidodynamic behavior in the pulsatile flow test.

Approaching comparability and results of pulsatile flow in vitro testing of prosthetic heart valves.

The testing of prosthetic heart valves under pulsatile conditions is still a subject for debate among researchers and competent standardization bodies. The laboratory of Biomedical Engineering, of the Istituto Superiore di Sanità in Rome, has reproduced the current inter-laboratory situation with several test apparatuses, focusing on the definition of significant measurement parameters and procedures to obtain reasonably comparable data. The laboratory is also equipped with a Laser Doppler Anemometer (LDA) and a High-Speed Cinematographic system (HSC). A 29 mm tilting disc valve model, was mounted in the aortic position. Under tightly controlled system conditions the analyses performed on two pulse duplicators (PDs) may be deemed consistent for the valve model tested. Useful results, on the same valve specimen, are reported concerning velocity profiles and turbulent shear stress values (TSS). Furthermore valve motion on the Sheffield PD was monitored during the closing phase, and related cinematic data reported. The applied methodologies can provide relevant data to support surgeon decision making.

Matching between theoretical and experimental data for ELF ion transport effects.

In recent years, several studies have been focused on the problem of nonthermal interaction between extremely low-frequency (ELF) electromagnetic fields and cell environment at membrane level. In the paper, to analyse the dynamic effects of weak static and harmonic fields on charged particles, some new considerations have been developed, based on the Lorentz model. The authors have reached a suitable formulation so that the data processing has led expressly to the evaluation of ionic-velocity components against magnetic-field amplitudes and frequencies, as well as a viscosity parameter. Even through a direct and rough comparison, the results of the authors' investigation have demonstrated an interesting agreement with some experimental data relative to ionic fluxes through cell membranes. Indeed, by means of an algorithm based on the techniques of the inversion theory, the author's have found definite values of the viscosity parameter for which the expected resonant behaviours (amplitude and frequency windows) fit existing experiments well. It seems worthy of interest that such viscosity values fall within a consistent, narrow range of low amplitude.

In vitro evaluation of prosthetic heart valves: towards comparable testing.

The Laboratory of Biomedical Engineering (of the National Health Institute, technical body of the Italian Health Service) performs in vitro testing of prosthetic heart valves for mechanical characteristics of materials, fatigue life, and fluidodynamic performance. Testing of materials is directed towards the physicomechanical characterization of the structural components of the valves, e.g. elasticity and resistance to stress of biological tissues and stents. Long-term fatigue life tests are conducted by means of systems which make valves beat at more than 1200 cycles/min. These tests are preceded and followed by geometrical characterization and by steady flow testing in order to obtain information about stenosis and leakage. Special attention is devoted to pulsatile flow testing which is performed on two pulse duplicators: the Dynatek system and the system developed by the University of Sheffield. The same valve was tested with these systems according to their different possible set-ups within the general requirements established by ISO-DIS 5840. This paper presents significant measurements, taking into account their dependence on the systems adopted. Results show (a) the difficulties in comparing test results because of different operating conditions, and (b) the systems' sensitivity with regards to some parameters which affect measurements under comparable set-up conditions (FDA Interlaboratory Comparison Testing Protocol).

Prosthetic heart valve evaluation in vitro: critical aspects of data comparability.

The technology of heart valve substitution has considerably improved in the last few years, but its reliability after implantation is still not good enough, hence the need to study new valve design and improve quality testing. Different pulse duplicators are used for heart valve testing, but the results depend very much on the system adopted and the measurement protocol. Tests on two pulse duplicators currently used at the Biomedical Engineering Laboratory at the Istituto Superiore di Sanità, Rome, are reported here. The most significant parameters for valve evaluation were measured following each system's own protocol. Attention was focused on vascular load tuning when setting up the system and on the relationship between drive unit flow waveform and valve regurgitation and energy loss measurements. Standardization criteria must be defined in order to ensure the reliable comparability of in vitro testing results.

Effects of culture media on murine hybridomas: definition of optimal conditions for hybridoma viability, cellular proliferation, and antibody production.

Different cell culture media were compared for their ability to support and promote the growth of stable hybridoma cell lines derived from three commonly used parental murine myelomas. Supplemented Dulbecco's modified Eagle's media (DMEM) and RPMI 1640 media were studied. The DMEM-based media were found to support greater numbers of cells for longer time periods than were the RPMI 1640-based media. Aminopterin supplemented medium was shown to be significantly less effective in supporting hybridoma reproduction and viability than medium without aminopterin. Antibody levels were directly related to cell concentration and viability regardless of the medium used for the hybridoma culture. An optimally formulated DMEM-based medium is suggested as the medium of choice for hybridoma propagation and maintenance.

A voice-entry data management system: application in monoclonal antibody research.

A computerized system for the management of hybridoma cell growth data using voice input is described. The system permits the storage, retrieval, and analysis of data for hybridoma cells secreting monoclonal antibodies. It consists of a local system residing on a professional computer interfaced to a mainframe processing system. The local system uses voice-input to facilitate data entry while data flagged for retention is stored on the mainframe. The system permits the investigator to monitor thousands of candidate cell lines until selection for specific antibody production is completed. All record-keeping aspects of hybridoma cell culture from establishment through freezing and storage of selected cell lines can be accomplished by personnel without computer expertise.