Increase in the influenza vaccination rates in Portugal: comparing 2020-2021 to the last 10 years

Background

Annual influenza vaccine uptake is recommended by the Portuguese General-Directorate of Health to certain priority groups. In 2020, amidst the COVID-19 pandemic, some exceptional measures were adopted to operationalize the Portuguese influenza vaccination campaign, like the extension and phasing of the vaccination period. No major changes were introduced in the vaccination of healthcare workers. In Baixo Tâmega health cluster (Portugal), it was perceived that these workers' vaccine uptake had markedly increased in 2020-2021. This study aims to compare their influenza vaccination coverage rates in 2020-2021 to the last 10 seasons.

Methods

A cross-sectional study of the vaccine uptake among the health workers of Baixo Tâmega health cluster was developed. A descriptive analysis was carried out, calculating annual influenza vaccination coverage rates from 2010-2011 to 2020-2021, in doctors, nurses and other health workers. Inferential analysis was performed through chi-squared tests in IBM SPSS Statistics 27.0.1.0., considering significant p-values<0.05.

Results

The difference between health workers 2020-2021's influenza coverage rate and the last season's average rates was 22.81%. Before 2020-2021, average vaccination coverage rates were 51.60% (standard deviation 7.34%, 44.26-58.94%), 60.44% (standard deviation 4.12%, 56.32-64.56%) and 51.20% (standard deviation 7.66%, 43.54-58.86%), in doctors, nurses and other health workers, respectively. In 2020-2021, vaccination rates significantly increased to 79.34%, 79.52% and 74.24% in doctors, nurses and others, respectively (p < 0.001).

Conclusions

Influenza vaccination uptake increased in 2020-2021 among health workers. Further studies should be developed to evaluate this tendency on a larger scale and to better understand its associated factors, which could have been unstructured awareness-raising campaigns, perception of protection against COVID-19 or avoidance of COVID-19-like symptoms and coinfection.

Key messages

Influenza vaccination coverage rates increased in 2020-2021 among the healthcare workers of a Portuguese health cluster. The COVID-19 pandemic may have contributed to the increase in the influenza vaccination coverage rates.

Mucosal immune responses in Senegalese sole (Solea senegalensis) juveniles after Tenacibaculum maritimum challenge: A comparative study between ocular and blind sides

Most pathogens start the process of infection at the mucosal surfaces and therefore the mucosal immune response plays an essential role in the course of the infection. Due to the Senegalese sole (Solea senegalensis Kaup) condition of flatfish, the present comparative study aimed to analyse several immune-related enzymes as well as the bactericidal activity in the skin mucus from ocular and blind sides. For this purpose, Senegalese sole juveniles were bath challenged with a sub-lethal dose of Tenacibaculum maritimum for 24 h and sampled at 1, 2 and 3 weeks. The haematological profile and immune-related parameters were also measured in plasma in order to evaluate the systemic immune response after T. maritimum challenge. Results from this study showed that most parameters tested increased in skin mucus of bath challenged fish compared to unchallenged ones. In contrast, the sub-lethal dose tested did not influence the haematological profile including peripheral numbers the different leucocyte types. No variations were observed in plasma lysozyme, peroxidase, protease and haemolytic complement activities between unchallenged and bath challenged fish. This study suggests that the studied innate immune-related molecules are constitutively present in both skin mucus sides but at different levels. Interestingly, the levels of most parameters measured were higher on the ocular side than on the blind side, possibly due to the higher exposure to invasion by waterborne microorganisms on this side. Therefore, the present study brings some insights regarding local immune responses after bacterial challenge in skin mucus from the ocular and blind sides in one of the most valuable flatfish species in southern Europe.

Clinical ultrasound in the management of polytraumatized patients in the daily practice of the anesthesiologist

Ultrasound has an important role in the diagnosis and prognosis of polytrauma patients. We describe a case of a 52-year-old man with hemodynamic instability and multiple injuries. Abdominal ultrasound evaluation was positive for hemoperitoneum, so an exploratory laparotomy was performed. During the intraoperative period, lung ultrasound was used to exclude traumatic lung injury. In the right lung, lung ultrasound suggested the presence of pneumothorax, and in the left a subpleural consolidation. Subsequently, a computed tomography was performed, confirming the sonographic findings. On the fourth admission day, he underwent surgical correction of a left hip fracture. A type 2 quadratus lumborum block (ultrasound-guided) was performed before surgical incision. The procedure was uneventful. The patient remained hemodynamically stable, without indirect signs of pain. This case shows that ultrasound-guided examination plays a crucial role in the management of polytrauma patients. It was a fundamental diagnostic tool in the initial evaluation, and was also used during surgery.

Mucosal and systemic immune responses in Senegalese sole (Solea senegalensis Kaup) bath challenged with Tenacibaculum maritimum: A time-course study

Tenacibaculosis, caused by Tenacibaculum maritimum, continues to inflict substantial losses among cultured marine species, particularly in the Senegalese sole. However, the immune mechanisms in fish involved in fighting against this disease are still poorly understood. Thus, the present study aimed to investigate the skin mucus's terminal carbohydrate composition, several immune-related enzymes (i.e. lysozyme, peroxidase, proteases and antiproteases), the haemolytic activity of complement and the bactericidal activity in the skin mucus and plasma of the Senegalese sole in a time-course study following a bath challenge with T. maritimum. The haematological profile and the kinetics of cell migration post-infection were also considered. The bath challenge induced slight variations in the terminal carbohydrate composition of Senegalese sole skin mucus. In general, results from this study showed a delay in the mucosal immune response compared to that found at the systemic level (i.e. blood and plasma). For instance, a significant increase in the skin mucus's lysozyme, complement, protease and antiprotease activities were observed at the end of the experiment (14 d post-challenge). Interestingly, the higher activity of these enzymes could be related to the skin mucus's bactericidal capacity and haemolytic complement activity, suggesting that these enzymes play an important role in the defence against Gram-negative bacteria. The haematological profile revealed a significant increase in circulating neutrophils in challenged fish after 48 and 72 h, which was positively correlated to the increments observed in peroxidase and lysozyme activities, respectively, in the plasma of challenged fish at the same time. Although the route of entry and the survival strategy of T. maritimum are still not fully elucidated, results from the present study will contribute to this endeavour through the study of the mucosal immune responses of fish against this particular pathogen.

Dental pulp stem cells and Bonelike® for bone regeneration in ovine model

Development of synthetic bone substitutes has arisen as a major research interest in the need to find an alternative to autologous bone grafts. Using an ovine model, the present pre-clinical study presents a synthetic bone graft (Bonelike^®) in combination with a cellular system as an alternative for the regeneration of non-critical defects. The association of biomaterials and cell-based therapies is a promising strategy for bone tissue engineering. Mesenchymal stem cells (MSCs) from human dental pulp have demonstrated both in vitro and in vivo to interact with diverse biomaterial systems and promote mineral deposition, aiming at the reconstruction of osseous defects. Moreover, these cells can be found and isolated from many species. Non-critical bone defects were treated with Bonelike^® with or without MSCs obtained from the human dental pulp. Results showed that Bonelike^® and MSCs treated defects showed improved bone regeneration compared with the defects treated with Bonelike^® alone. Also, it was observed that the biomaterial matrix was reabsorbed and gradually replaced by new bone during the healing process. We therefore propose this combination as an efficient binomial strategy that promotes bone growth and vascularization in non-critical bone defects.

Annual assessment of the sea urchin (Paracentrotus lividus) humoral innate immune status: Tales from the north Portuguese coast

Innate immune status of the sea urchin Paracentrotus lividus population from two different rocky shore beaches in the northern Portuguese coast was evaluated for a period of one year. Although some ecological studies regarding the effect of toxics on the immune parameters of the sea urchin were made in Portuguese waters, there is a current lack of knowledge concerning their immune status all over the year. In perspective of a changing ecosystem in these waters due to global warming and colonization of new species, it is important to assess the status of the major species living in the area. In this way, immune parameters such as total protein content, nitric oxide concentration, haemolytic activity, protease activity, lysozyme concentration and bactericidal activity were evaluated in the perivisceral coelomic fluid, and were correlated with the gonadal index of the population and water parameters. Also, the spawning period can upset some immune status parameters, and others such as haemolytic activity and bactericidal activity against Vibrio anguillarum, showed a clear correlation with the gonad maturation status. The knowledge of the basal immune status of the species could serve as ecological indicator of some stress agent or contaminant into the field; also, coelomic fluid is suggested as good quality marker to assess the immune status of sea urchins.

Local immune response of two mucosal surfaces of the European seabass, Dicentrarchus labrax, fed tryptophan- or methionine-supplemented diets

Immune responses relies on an adequate provision of multiple nutrients that sustain the synthesis of key effector molecules. These needs are depicted in the already reported increase of circulating free amino acids in fish under stressful conditions. Since aquaculture and the inherent fish welfare are an emergent call, the immunomodulatory effects of amino acids on gut- and skin-associated lymphoid tissues of the European seabass (Dicentrarchus labrax) were studied under unstressed conditions and after an inflammatory insult. To achieve this goal, fish were distributed in duplicate tanks (fifteen fish per tank) and were fed for 14 days with methionine or tryptophan-supplemented diets at 2× dietary requirement level (MET and TRP, respectively) or a control diet meeting the amino acids requirement levels (CTRL). Afterwards, samples of skin and posterior gut were collected from 6 fish per dietary treatment for the assessment of the immune status while the remaining animals were intraperitoneally-injected with inactivated Photobacterium damselae subsp. piscicida and subsequently sampled either 4 or 24 h post-injection. The immune status of both mucosal surfaces was poorly affected, although a tryptophan effect was denoted after bacterial inoculation, with several immune-related genes up-regulated in the gut at 4 h post-injection, which seems to suggest a neuroendocrine-immune systems interaction. In contrast, skin mucosal immunity was inhibited by tryptophan dietary supplementation. Regarding methionine, results were often statistically non-significant, though increasing trends were denoted in a few parameters. Overall, dietary methionine did not significantly affect neither gut nor skin immunity, whereas tryptophan supplementation seems to induce modulatory mechanisms that might be tissue-specific.

Tenacibaculosis induction in the Senegalese sole (Solea senegalensis) and studies of Tenacibaculum maritimum survival against host mucus and plasma

Tenacibaculum maritimum, the aetiological agent for marine tenacibaculosis, is one of the most significant pathogens that threaten Senegalese sole, Solea senegalensis (Kaup), aquaculture. Because no immersion challenge with T. maritimum has been reported previously for this flatfish species, this study aimed to optimize bacterial yields as well as to establish a challenge model for tenacibaculosis induction. Several approaches were performed to optimize bacterial culture conditions, including treatment with non-ionic surfactants, detergents, cellulase hydrolysis and strong shaking. A prolonged bath challenge was performed for 24 h under two different temperatures, 16 and 23 °C. Moreover, mucus and plasma bactericidal activities against T. maritimum were also assessed. Culturing bacteria with strong shaking and continuous shaking provided suitable culture conditions to obtain higher bacterial yields without aggregation and fluctuation, contrary to most other treatments that showed a huge amount of bacterial aggregates. A prolonged bath method for 24 h, without skin or gill scarification, was considered suitable for disease induction with high mortality rates. Moreover, data regarding mucus and plasma bactericidal activities suggested that there is a lack of host innate immune response against T. maritimum or that this particular pathogen presents evading strategies against Senegalese sole.

In vivo Performance of Biodegradable Calcium Phosphate Glass Ceramics using the Rabbit Model: Histological and SEM Observation

Two MK5 (45CaO-45P2O5-5MgO-5K2O, in mol%) and MT13 (45CaO-37P2O5-5MgO-13TiO2, in mol%) glasses are prepared in the meta- and pyrophosphate regions and crystallized to obtain MK5B and MT13B, respectively. MK5B was obtained by controlled crystallization, and MT13B by powder sintering. As a result of these heat treatment processes, the crystalline phases precipitated in the glassy matrix are KCa(PO3)3, β-Ca(PO3)2, β-Ca2P2O7and Ca4P6O19phases for MK5B and CaTi4(PO4)6, TiP2O7, α- and β-Ca2P2O7phases for MT13B. To assess the in vivo biological behavior of these glass ceramics, a mixed granulometry in the range 250-355 μm and 355-425 μm with a ratio of 1/1 was implanted for 2, 4, and 12 weeks in the tibiae of Japanese white rabbits. The results showed that the in vivo behavior was strongly affected by their solubility. All implanted materials, MK5B and MT13B, and β-tricalcium phosphate (β-TCP) as control material, showed signs of degradation in vivo. However, the levels of degradation were quite different throughout the implantation periods. The highest degradation was observed for MK5B glass ceramic and the lowest for MT13B with β-TCP in-between. All implanted materials allow for new bone formation in the bone defect area. At the longest implantation period (12 weeks), the MT13B and β-TCP materials were almost completely surrounded by new bone tissue, whereas MK5B showed some unfilled spaces. This behavior is discussed in terms of the high degradation observed in previous studies.

Applicability and feasibility of systematic review for performing evidence-based risk assessment in food and feed safety

Food and feed safety risk assessment uses multi-parameter models to evaluate the likelihood of adverse events associated with exposure to hazards in human health, plant health, animal health, animal welfare, and the environment. Systematic review and meta-analysis are established methods for answering questions in health care, and can be implemented to minimize biases in food and feed safety risk assessment. However, no methodological frameworks exist for refining risk assessment multi-parameter models into questions suitable for systematic review, and use of meta-analysis to estimate all parameters required by a risk model may not be always feasible. This paper describes novel approaches for determining question suitability and for prioritizing questions for systematic review in this area. Risk assessment questions that aim to estimate a parameter are likely to be suitable for systematic review. Such questions can be structured by their "key elements" [e.g., for intervention questions, the population(s), intervention(s), comparator(s), and outcome(s)]. Prioritization of questions to be addressed by systematic review relies on the likely impact and related uncertainty of individual parameters in the risk model. This approach to planning and prioritizing systematic review seems to have useful implications for producing evidence-based food and feed safety risk assessment.

How to Assess Data Availability, Accessibility and Format for Risk Analysis?

Risk assessments are mostly carried out based on available data, which do not reflect all data theoretically required by experts to answer them. This study aimed at developing a methodology to assess data availability, accessibility and format, based on a scoring system and focusing on two diseases: Venezuelan equine encephalomyelitis (VEE), still exotic to Europe, and alveolar echinococcosis, caused by Echinococcus multilocularis (EM), endemic in several Member States (MSs). After reviewing 36 opinions of the EFSA-AHAW Panel on risk assessment of animal health questions, a generic list of needed data was elaborated. The methodology consisted, first, in implementing a direct and an indirect survey to collect the data needed for both case studies: the direct survey consisted in a questionnaire sent to contact points of three European MSs (Belgium, France and the Netherlands), and the organization of a workshop gathering experts on both diseases. The indirect survey, focusing on the three MSs involved in the direct survey plus Spain, relied on web searches. Secondly, a scoring system with reference to data availability, accessibility and format was elaborated, to, finally, compare both diseases and data between MSs. The accessibility of data was generally related to their availability. Web searches resulted in more data available for VEE compared to EM, despite its current exotic status in the European Union. Hypertext markup language and portable document files were the main formats of available data. Data availability, accessibility and format should be improved for research scientists/assessors. The format of data plays a key role in the feasibility and rapidness of data management and analysis, through a prompt compilation, combination and aggregation in working databases. Harmonization of data collection process is encouraged, according to standardized procedures, to provide useful and reliable data, both at the national and the international levels for both animal and human health; it would allow assessing data gaps through comparative studies. The present methodology is a good way of assessing the relevance of data for risk assessment, as it allows integrating the uncertainty linked to the quality of data used. Such an approach could be described as transparent and traceable and should be performed systematically.

A new sheep model with automatized analysis of biomaterial-induced bone tissue regeneration

Presently, several bone graft substitutes are being developed or already available for clinical use. However, the limited number of clinical and in vivo trials for direct comparison between these products may complicate this choice. One of the main reasons for this scarcity it is the use of models that do not readily allow the direct comparison of multiple bone graft substitutes, due especially to the small number of implantation sites. Although sheep cancellous bone models are now well established for these purposes, the limited availability of cancellous bone makes it difficult to find multiple comparable sites within a same animal. These limitations can be overcome by the monocortical model here proposed as it consists in 5-6 holes (5 mm Ø), in the femoral diaphysis, with similar bone structure, overlying soft tissue and loading pattern for all defects. Associated to this model, it is also described a fast histomorphometric analysis method using a computer image segmentation test (Threshold method) to assess bone regeneration parameters. The information compiled through the experimental use of 45 sheep in several studies allowed determining that this ovine model has the potential to demonstrate differences in bone-forming performance between various scaffolds. Additionally, the described histomorphometric method is fast, accurate and reproducible.

Morphology effect of bioglass-reinforced hydroxyapatite (Bonelike(®) ) on osteoregeneration

In the last decades, the well-known disadvantages of autografts and allografts have driven to the development of synthetic bone grafts for bone regeneration. Bonelike(®) , a glass-reinforced hydroxyapatite (HA) composite was developed and registered for bone grafting. This biomaterial is composed by a modified HA matrix, with α- and β-tricalcium phosphate secondary phases. Aiming to improve the biological characteristics of Bonelike(®) , new spherical pelleted granules, of different shape and size, were developed with controlled micro and macrostructure. In the present study, it was compared the physicochemical properties and in vivo performance of different Bonelike(®) granule presentations-Bonelike(®) polygonal (500-1000 µm size) and Bonelike spherical (250-500 µm; 500-1000 µm size). For the in vivo study, Bonelike(®) was implanted on sheep femurs, with various implantation times (30 days, 60 days, 120 days, and 180 days). X-ray diffraction analysis revealed that the phase composition of different granules presentations was similar. Bonelike(®) spherical 500-1000 µm was the most porous material (global porosity and intraporosity) and Bonelike(®) polygonal 500-1000 µm the less porous. Considering the in vivo study, both polygonal and spherical granules presented osteoconductive proprieties. The spherical granules showed several advantages, including easier medical application through syringe and improved osteointegration, osteoconduction, and degradation, by the presence of larger pores, controlled micro- and macrosctructure and suitable particle format that adapts to bone growth. Bonelike(®) spherical 500-1000 µm showed improved new bone invasion throughout the material's structure and Bonelike(®) spherical 250-500 µm appeared to induce faster bone regeneration, presenting less unfilled areas and less lacunae in the histological analysis.

The frequency and distribution of canine leishmaniosis diagnosed by veterinary practitioners in Europe

This study aimed to evaluate the frequency and spatial distribution of canine leishmaniosis (CanL) in France, Greece, Italy, Portugal and Spain. An online questionnaire investigated the location and frequency of CanL cases diagnosed by veterinary practitioners. Further data from the practice management systems of veterinary clinics in France were provided by a financial benchmarking company in relation to all treatment and test invoice data from participating practices. The geographical and temporal web interest in leishmaniosis was explored using Google Trends. Veterinary practitioners from France, Greece, Italy, Portugal and Spain completed 1231 questionnaires. The percentage of practice-attending dogs with a veterinary diagnosis of CanL ranged from 0.71% in France to 7.80% in Greece. However, due to regional differences in response rates, particularly in France, the mean regional estimates may better reflect the disease burden. Benchmarking data relating to approximately 180,000 dogs estimated that 0.05% of dogs attending veterinary clinics were treated for CanL or euthanased with suspected CanL in France. The regional frequency of Google web queries for leishmaniosis generally reflected the spatial patterns of disease identified from the other data sources. In conclusion, CanL was a relatively common diagnosis in veterinary clinics in many regions of the countries studied. Knowledge of CanL in endemic areas can direct the use of preventative measures and help estimate the likelihood of infection in dogs visiting or inhabiting these countries.

Cellular and humoral immune responses of Senegalese sole, Solea senegalensis (Kaup), following challenge with two Photobacterium damselae subsp. piscicida strains from different geographical origins

The present study aimed to investigate leucocyte responses to inflammation as well as some innate immune parameters of Senegalese sole, Solea senegalensis, following challenge with two strains of Photobacterium damselae subsp. piscicida belonging to the European and Japanese clones described for this bacterium. Pathogenicity assays were performed to assess the virulence of each Photobacterium damselae subsp. piscicida strain for sole. Subsequently, fish were intraperitoneally injected with phosphate-buffered saline (control) or two concentrations (2 × 10² and 2 × 10⁶ CFU mL⁻¹) of each bacterial strain and sampled after 6 and 24 h. Results showed that the European isolate induces a higher degree of response than the Japanese strain. While blood neutrophilia and monocytosis correlated well with the increase in neutrophil and macrophage numbers in the peritoneal cavity, fish infected with the European isolate presented higher peritoneal cell numbers than fish challenged with the Japanese strain. In addition, alternative complement pathway activity and respiratory burst of head kidney leucocytes increased significantly in fish infected with the European isolate. The enhanced innate immune response displayed by Senegalese sole challenged with the European isolate is probably due to the higher degree of virulence presented by this Photobacterium damselae subsp. piscicida strain.

Q fever in humans and farm animals in four European countries, 1982 to 2010

Q fever is a disease of humans, caused by Coxiella burnetii, and a large range of animals can be infected. This paper presents a review of the epidemiology of Q fever in humans and farm animals between 1982 and 2010, using case studies from four European countries (Bulgaria, France, Germany and the Netherlands). The Netherlands had a large outbreak between 2007 and 2010, and the other countries a history of Q fever and Q fever research. Within all four countries, the serological prevalence of C. burnetii infection and reported incidence of Q fever varies broadly in both farm animals and humans. Proximity to farm animals and contact with infected animals or their birth products have been identified as the most important risk factors for human disease. Intrinsic farm factors, such as production systems and management, influence the number of outbreaks in an area. A number of disease control options have been used in these four countries, including measures to increase diagnostic accuracy and general awareness, and actions to reduce spillover (of infection from farm animals to humans) and human exposure. This study highlights gaps in knowledge, and future research needs.

Q fever in humans and farm animals in four European countries, 1982 to 2010

Q fever is a disease of humans, caused by Coxiella burnetii, and a large range of animals can be infected. This paper presents a review of the epidemiology of Q fever in humans and farm animals between 1982 and 2010, using case studies from four European countries (Bulgaria, France, Germany and the Netherlands). The Netherlands had a large outbreak between 2007 and 2010, and the other countries a history of Q fever and Q fever research. Within all four countries, the serological prevalence of C. burnetii infection and reported incidence of Q fever varies broadly in both farm animals and humans. Proximity to farm animals and contact with infected animals or their birth products have been identified as the most important risk factors for human disease. Intrinsic farm factors, such as production systems and management, influence the number of outbreaks in an area. A number of disease control options have been used in these four countries, including measures to increase diagnostic accuracy and general awareness, and actions to reduce spill-over (of infection from farm animals to humans) and human exposure. This study highlights gaps in knowledge, and future research needs.

Characterization and preliminary in vivo evaluation of a novel modified hydroxyapatite produced by extrusion and spheronization techniques

A glass-reinforced hydroxyapatite (HA) composite, recently registered as Bonelike®, was developed for bone grafting. This biomaterial is composed of a modified HA matrix with α- and β-tricalcium phosphate secondary phases and ionic species that mimic the chemical composition of human bone. Several in vitro and in vivo studies have confirmed the benefits of these properties. However, these studies were all executed with Bonelike® polygonal granules obtained by crushing. In this study, Bonelike® pellets were produced through a patented process, which required the use of techniques such as extrusion and spheronization. The final product presented a homogeneous size, a 55.1% global porosity and a spherical shape. This spherical shape permitted a better adaptation to the implantation site and improved injectability. Additionally, it also may contribute to formation of macropores as pellets packaging leaves open spaces. After implantation of Bonelike® polygonal granules and Bonelike® pellets in monocortical defects in sheep for 8 and 12 weeks, light microscopy and scanning electron microscopy showed extensive osteointegration simultaneously with bone regeneration for both presentations. Histomorphometric analysis did not reveal statistically significant differences between defects treated with Bonelike® polygonal granules and Bonelike® pellets, which suggests similar in vivo performances.

Epizootic heamorragic disease

Epizootic haemorrhagic disease (EHD) is an infectious non-contagious viral disease transmitted by insects of the genus Culicoides which affects wild and domestic ruminants. The causative agent, the epizootic haemorrhagic disease virus (EHDV), belongs to the family Reoviridae, genus Orbivirus and shares many morphological and structural characteristics with the other members of the genus such as bluetongue, African horse sickness and equine encephalosis viruses. In recent years EHD outbreaks have been reported in countries bordering the European Union. They caused disease in cattle and severe repercussion on the livestock industry of the affected countries. In the light of recent European bluetongue epizootic these events pose an increasing threat to the European Union. This review includes the most recent information regarding the virus and the disease as well as tools for its diagnosis and control. It is our conviction that more attention should be drawn to both EHDV and the disease itself in order to fulfil all these gaps and not to be unprepared in case future possible incursions.

Mathematical model for describing cerebral oxygen desaturation in patients undergoing deep hypothermic circulatory arrest

BACKGROUND

Surgical treatment for aortic arch disease requiring periods of circulatory arrest is associated with a spectrum of neurological sequelae. Cerebral oximetry can non-invasively monitor patients for cerebral ischaemia even during periods of circulatory arrest. We hypothesized that cerebral desaturation during circulatory arrest could be described by a mathematical relationship that is time-dependent.

METHODS

Cerebral desaturation curves obtained from 36 patients undergoing aortic surgery with deep hypothermic circulatory arrest (DHCA) were used to create a non-linear mixed model. The model assumes that the rate of oxygen decline is greatest at the beginning before steadily transitioning to a constant. Leave-one-out cross-validation and jackknife methods were used to evaluate the validity of the predictive model.

RESULTS

The average rate of cerebral desaturation during DHCA can be described as: Sct(o(2))[t]=81.4-(11.53+0.37 x t) (1-0.88 x exp (-0.17 x t)). Higher starting Sct(o(2)) values and taller patient height were also associated with a greater decline rate of Sct(o(2)). Additionally, a predictive model was derived after the functional form of a x log (b+c x delta), where delta is the degree of Sct(o(2)) decline after 15 min of DHCA. The model enables the estimation of a maximal acceptable arrest time before reaching an ischaemic threshold. Validation tests showed that, for the majority, the prediction error is no more than +/-3 min.

CONCLUSIONS

We were able to create two mathematical models, which can accurately describe the rate of cerebral desaturation during circulatory arrest at 12-15 degrees C as a function of time and predict the length of arrest time until a threshold value is reached.

Bone ingrowth in macroporous Bonelike for orthopaedic applications

The aim of this study was to evaluate the biological behaviour of porous scaffold structures of Bonelike which is suitable for either direct clinical use or tissue engineering applications. Porous cylindrical specimens 8x10mm were implanted in the lateral aspect of the tibia of 13 patients (mean age 54 years), during osteotomy surgery for the treatment of medial compartment osteoarthritis of the knee. Implanted cylinders were retrieved at the same time as the removal of the blade plates at 3, 6, 9 and 12 months. Scanning electron microscopy and histological evaluations were performed to observe the biological responses of human bone tissue to porous Bonelike. The penetration depth was determined for all implantation periods, and after 6 months it was already possible to see new bone in the centre of the implanted cylinders, which gives 100% of penetration depth for all implantations periods except for 3 months when bone could only be seen in the peripherical region. Regarding the percentage of the area covered by new bone calculated from two-dimensional histological sections, values of 53+/-15, 76+/-12 and 88+/-9% were achieved for 6, 9 and 12 months, respectively. Due to its structural features porous Bonelike permitted effective vascularization and bone ingrowth, and therefore was fully osteointegrated as shown in the histological surveys. A slow biomaterial degradation with implantation time is envisaged since the material has displayed surface degradation. Bonelike scaffolds show potential for complete ingrowth of osseous tissue and restoration of vascularization throughout the defected site.

[Leishmania infantum/HIV co-infection: cutaneous lesions following treatment of visceral leishmaniasis]

BACKGROUND

The Mediterranean basin is an endemic region of leishmaniasis caused by Leishmania infantum. With the advent of human immunodeficiency virus (HIV) infection, the number of cases of visceral leishmaniasis has dramatically increased in this area over the last years, mainly in adults. Moreover, the presence of cutaneous lesions infested with Leishmania has been frequently reported in these patients.

CASE-REPORT

A 35-year-old Portuguese woman, a former intravenous drug user HIV1-positive since 1997, developed visceral leishmaniasis in 2000, with several relapses in 2001 and 2002, treated successively with pentavalent antimonial salts (Glucantime), liposomal amphotericin B and Glucantime associated with itraconazole. Several weeks after therapy for the second relapse of visceral leishmaniasis, physical examination revealed asymptomatic erythematous papules on the face that later spread to the trunk and upper limbs. Histopathologic studies of a skin biopsy revealed a granulomatous infiltrate in the dermis with the presence of Leishmania amastigotes. After culture, the parasite was identified as L. infantum MON-1. In spite of improvement of the patient's visceral leishmaniasis with the above-mentioned treatment, the cutaneous lesions became increasingly numerous and infiltrated. After 2 months of therapy with intravenous pentamidine (4 mg/kg/3 times a week) and oral dapsone (100 mg b.i.d), the cutaneous lesions disappeared completely. Prevention with dapsone was successfully maintained for 6 months. Several weeks after discontinuation of treatment, further lesions appeared. The patient improved again on reintroduction of dapsone.

DISCUSSION

This case confirmed the existence of a clinical form similar to post-kala-azar dermal leishmaniasis in a patient co-infected with L. infantum MON-1/HIV. The cutaneous lesions were resistant to classical antileishmanial drugs but disappeared on treatment with dapsone.

Histological and scanning electron microscopy analyses of bone/implant interface using the novel Bonelike synthetic bone graft

Synthetic bone grafts provide an alternative to autografts and allografts. Bonelike is a patented synthetic bone graft that mimics the mineral composition of bone. The aim of the present work was to assess the biological behavior of Bonelike graft in humans, before using the material in orthopedic applications of bone regeneration, for example, in opening wedge high tibial osteotomies for medial knee osteoarthritis. Bonelike granules were implanted in cortical bone of 11 patients undergoing osteotomies, and new bone formation, osteoconductive properties, and resorption characteristics of the granules were analyzed. The granules ranged from 500 to 1000 microm and were implanted in the lateral aspect of the tibia. The patients' mean age was 59 years (range 48 to 70 years); there were eight women and three men, all suffering from medial compartment osteoarthritis of the knee. At surgery, a 1 x 1 x 1-cm cortical defect was created 3 cm distal to the entry point of the screws, in line with the long axis of tibia. The implanted Bonelike graft sample was extracted for analysis during removal of the metallic prosthesis after implantation times of 6, 9, and 12 months. Radiological follow-up, scanning electron microscopy, histological analysis, and histomorphometric measurements were conducted on the retrieved samples to assess bone regeneration in the defect area. Osteoconductive capacity was demonstrated by extensive mature bone formation around the implanted granules and high levels of percentage bone-to-graft contact (from 67-84%). Bonelike acted as an excellent bioactive scaffold, allowing the migration, proliferation, and differentiation of bone cells on its surface, and therefore regeneration of the defects was achieved in a rapid, controlled manner. Our results suggest that Bonelike graft is an excellent candidate for orthopedic applications where rapid new bone formation is a fundamental requirement.

Malaria parasites can develop stable resistance to artemisinin but lack mutations in candidate genes atp6 (encoding the sarcoplasmic and endoplasmic reticulum Ca2+ ATPase), tctp, mdr1, and cg10

Resistance of Plasmodium falciparum to drugs such as chloroquine and sulfadoxine-pyrimethamine is a major problem in malaria control. Artemisinin (ART) derivatives, particularly in combination with other drugs, are thus increasingly used to treat malaria, reducing the probability that parasites resistant to the components will emerge. Although stable resistance to artemisinin has yet to be reported from laboratory or field studies, its emergence would be disastrous because of the lack of alternative treatments. Here, we report for the first time, to our knowledge, genetically stable and transmissible ART and artesunate (ATN)-resistant malaria parasites. Each of two lines of the rodent malaria parasite Plosmodium chabaudi chabaudi, grown in the presence of increasing concentrations of ART or ATN, showed 15-fold and 6-fold increased resistance to ART and ATN, respectively. Resistance remained stable after cloning, freeze-thawing, after passage in the absence of drug, and transmission through mosquitoes. The nucleotide sequences of the possible genetic modulators of ART resistance (mdr1, cg10, tctp, and atp6) of sensitive and resistant parasites were compared. No mutations in these genes were identified. In addition we investigated whether changes in the copy number of these genes could account for resistance but found that resistant parasites retained the same number of copies as their sensitive progenitors. We believe that this is the first report of a malaria parasite with genetically stable and transmissible resistance to artemisinin or its derivatives.

Side effects in sea bass (Dicentrarchus labrax L.) due to intraperitoneal vaccination against vibriosis and pasteurellosis

Sea bass (Dicentrarchus labrax L.) were injected intraperitoneally with monovalent (Photobacterium damselae subsp. piscicida or Vibrio anguillarum) and divalent (Ph. damselae subsp. piscicida and V. anguillarum) vaccine formulations, with or without adjuvants (mineral oil, liposome or alginate), to evaluate the short and long-term pathological effects. Eight animals from each group were sampled one, two, four and 11 months after intraperitoneal injection. The acute peritoneal response and the progression to a chronic status were evaluated by analysing peritoneal leucocytes collected during the first days post-injection. To evaluate the chronic response, the late peritoneal leucocyte response was analysed and the peritoneal cavity was examined and the intra-abdominal lesion level scored based on a pre-defined scale. Correlation between leucocyte exudative response, tissue inflammatory response and the development of granuloma were sought. The acute leucocyte response was characterized by an early (24-48 h) mobilization of neutrophils and macrophages, with phagocyte numbers dependent on the formulation, but no significant variations were observed in lymphocytes/small cells and EGCs. Later on, a steady increase occurred in lymphocytes/small cells and EGCs and a high concentration in neutrophils and macrophages was maintained up to 30-60 days in groups i.p. injected with oil adjuvanted formulations with antigen. All the lesions observed were moderate, indicating that in sea bass, the pathological effects due to intraperitoneally injected vaccines are less severe than in other fish species. The divalent oil adjuvanted vaccine induced the most severe side effects, with macroscopic granulomas consistently present up to 11 months.

Normal-law quantile phase filters for mode conversion in single-mode fibers applied to wavelength blockers

We propose the definition of a new family of complex-amplitude filters. These filters are optimal for mode conversion in single-mode fibers and give rise to a large variety of spatial designs. Among them, we focus on a few that are easy to manufacture and implement, in particular, in an array shape, and present some technical advantages such as tolerance to positioning. In the second part, we discuss their implementations by using various technologies and the effect of some technical constraints on filter shape and phase distribution. Finally, we illustrate their uses in the case of a dynamic wavelength blocker within the frame of wavelength-division-multiplexing network systems.

[Pregnancy and breastfeeding. Side effects of drugs used in the treatment of thyroid diseases, on the fetus and the newborn]

The authors allude to the composed anti-thyroid drugs, blocking drugs, iodides, radioactive iodine, lithium carbonate and tyrosine side effects. The most common are composed anti-thyroid drugs and tyrosine. Anti-thyroid drugs risks are related to the tresspassing of the placenta barrier which can induce in goitre and hypothyroidism. Thyroid hormones are also very important for the fetus neural development during the first quarter when they cross the placenta.

Pyoderma gangrenosum or leukaemia cutis?

We report a case of atypical bullous pyoderma gangrenosum associated with acute myeloid leukaemia in which we found atypical myeloid cells within the skin lesion. Although there have been many reported cases of leukaemia-associated pyoderma gangrenosum, the finding of myeloblasts in the skin has rarely been described.

Cutaneous infection due to Scedosporium apiospermum in an immunosuppressed patient

Scedosporium apiospermum, the anamorphic form of Pseudallescheria boydii, is a filamentous fungus with low inherent virulence. Increasing numbers of cases of this infection have been reported probably related to the rising number of immunosuppressed persons. Apart from mycetoma, cutaneous and subcutaneous infection is rarely encountered in clinical practice. We describe a case of cutaneous infection caused by Scedosporium apiospermum in a subject with rheumatoid arthritis and diabetes mellitus who was submitted to long-term therapy with cyclosporin and corticosteroids. Histopathologic examination of a skin biopsy showed a granulomatous infiltrate with hyaline septate hyphae. Culture of two skin biopsies taken at two different observations of the woman, 3 weeks apart, allowed isolation of Scedosporium apiospermum. Therapy with itraconazole, 400 mg/day, for 3 months was effective in curing the infection.

Psychoneuroendocrine characteristics of common obesity clinical subtypes

OBJECTIVE

To relate psychological profiles, cerebral asymmetry and the hypothalamus-pituitary-adrenal axis (HPA) reactivity to clinical characteristics of common obesity.

METHODS

Sixty consecutive adult female overweight and obese patients attending the outpatient endocrine department were included in this study. Clinical evaluation specifically selected a priori the following indexes: obesity age of onset, parenthood obesity, carbohydrate craving, binge eating with purging, obesity degree (defined by the body mass index (BMI)--weight (kg)/height (m(2))), body fat distribution (defined by the abdominal--thigh ratio (A/T)) and initial weight loss after medical treatment. Psychological evaluation was performed with the Minnesota Multiphasic Personality Inventory (MMPI). In the last 30 patients, the Edinburgh Inventory of Manual Preference (EIMP) and the corticotrophin-releasing hormone (CRH) test were also performed.

RESULTS

Clinical characteristics defined a priori were independent variables as evaluated by contingency table analysis. Factorial analysis of variance (ANOVA) revealed a significantly different MMPI profile, according to parental obesity, with post-hoc significantly higher scores on the hypochondriasis (Hs), paranoia (Pa), psychasthenia (Pt) and schizophrenia (Sc) scales in patients with obese parents. Obese patients presented significantly higher dichotomized manual preference indexes in relation to overweight patients. Parental obesity, binge eating behaviour with purging, body fat distribution and the dichotomized manual preference index were independent significant factors for the ACTH response in the CRH test, together explaining 41% of the response variability. Age of onset of obesity and the dichotomized manual preference index were independent and significant factors for the cortisol response, together explaining 37% of its variability. A non-normal distribution was found for the ACTH response: high- and low-responders presented significantly different MMPI profiles, with high-responders presenting higher scores on all clinical scales except masculinity/femininity (Mf).

CONCLUSION

Overweight/obese subjects with parental obesity present a distinctive personality profile and a higher ACTH response in the CRH test. Cerebral asymmetry may be a relevant factor for obesity development and is associated with the HPA reactivity. HPA reactivity is a sensitive index integrating clinical, psychological and neural asymmetric factors. International Journal of Obesity (2001) 25, 24-32