Accuracy of a pre-trained sentiment analysis (SA) classification model on tweets related to emergency response and early recovery assessment: the case of 2019 Albanian earthquake

Traditionally, earthquake impact assessments have been made via fieldwork by non-governmental organisations (NGO's) sponsored data collection; however, this approach is time-consuming, expensive and often limited. Recently, social media (SM) has become a valuable tool for quickly collecting large amounts of first-hand data after a disaster and shows great potential for decision-making. Nevertheless, extracting meaningful information from SM is an ongoing area of research. This paper tests the accuracy of the pre-trained sentiment analysis (SA) model developed by the no-code machine learning platform MonkeyLearn using the text data related to the emergency response and early recovery phase of the three major earthquakes that struck Albania on the 26th November 2019. These events caused 51 deaths, 3000 injuries and extensive damage. We obtained 695 tweets with the hashtags: #Albania #AlbanianEarthquake, and #albanianearthquake from the 26th November 2019 to the 3rd February 2020. We used these data to test the accuracy of the pre-trained SA classification model developed by MonkeyLearn to identify polarity in text data. This test explores the feasibility to automate the classification process to extract meaningful information from text data from SM in real-time in the future. We tested the no-code machine learning platform's performance using a confusion matrix. We obtained an overall accuracy (ACC) of 63% and a misclassification rate of 37%. We conclude that the ACC of the unsupervised classification is sufficient for a preliminary assessment, but further research is needed to determine if the accuracy is improved by customising the training model of the machine learning platform.

The Role of Fibrinolysis in the Pathogenesis of the Haemorrhagic Syndrome Produced by Virulent Isolates of African Swine Fever Virus

The activity of several proteins involved in fibrinolysis and the morphological changes in the blood vessel walls of pigs infected with highly virulent (Malawi’83) and moderately virulent (Dominican Republic ‘78-DR’78) ASF virus isolates were determined. Pigs infected with the Malawi’83 virus developed an increased fibrinolytic activity due to high plasma levels of tissue-plasminogen activator (t-PA) of 71.3 ± 22.8 IU/ml (mean ± SD), which correlated well with an increased activation of interstitial capillary endothelial cells and high levels of 1150 ± 73.6 nM of fibrin monomer in the circulation. Animals infected with DR’78 virus, in contrast, showed an inhibition of fibrinolysis in the late stages of disease with almost a 5-fold increase of plasminogen activator inhibitor (PAI) activity of 196.0 AU/ml. These results suggest that activation of the fibrinolytic system in pigs infected with the Malawi’83 virus is probably due to increased formation and deposition of fibrin in the circulation, contributing to an increased bleeding tendency and higher mortality. On the contrary, animals infected with DR’78 virus developed an inhibition of fibrinolysis and thus a reduction in bleeding.

Spatial Division Multiplexed Microwave Signal processing by selective grating inscription in homogeneous multicore fibers

The use of Spatial Division Multiplexing for Microwave Photonics signal processing is proposed and experimentally demonstrated, for the first time to our knowledge, based on the selective inscription of Bragg gratings in homogeneous multicore fibers. The fabricated devices behave as sampled true time delay elements for radiofrequency signals offering a wide range of operation possibilities within the same optical fiber. The key to processing flexibility comes from the implementation of novel multi-cavity configurations by inscribing a variety of different fiber Bragg gratings along the different cores of a 7-core fiber. This entails the development of the first fabrication method to inscribe high-quality gratings characterized by arbitrary frequency spectra and located in arbitrary longitudinal positions along the individual cores of a multicore fiber. Our work opens the way towards the development of unique compact fiber-based solutions that enable the implementation of a wide variety of 2D (spatial and wavelength diversity) signal processing functionalities that will be key in future fiber-wireless communications scenarios. We envisage that Microwave Photonics systems and networks will benefit from this technology in terms of compactness, operation versatility and performance stability.

Sudden Death Associated with Clostridium sordellii in Captive Lions (Panthera leo)

In the spring of 2003, a series of sudden deaths in a group of adult lions ( Panthera leo) with a previous history of depression, inanition, and lethargy, was investigated. Five animals died within 24 to 36 hours after onset of signs of disease. Serologic screening for viral disease detection was negative, evidence of parasites was not detected, and results of a complete blood count and serum biochemical analysis were within reference intervals in all lions. The most relevant lesions observed were multiple areas of necrosis and hemorrhage in the intestinal outer muscular layer, and cellulitis with an intense bloody edema in the mesenteric and the pericardial fat tissue. On the basis of the fulminant course of the disease, the gross and histologic findings, and the isolation and identification of Clostridium sordellii, a diagnosis of infectious myositis and cellulitis associated with acute clostridiosis was made. To the authors' knowledge, this is the first report of sudden death associated with C. sordellii in felines.

MWP phase shifters integrated in PbS-SU8 waveguides

We present new kind of microwave phase shifters (MPS) based on dispersion of PbS colloidal quantum dots (QDs) in commercially available photoresist SU8 after a ligand exchange process. Ridge PbS-SU8 waveguides are implemented by integration of the nanocomposite in a silicon platform. When these waveguides are pumped at wavelengths below the band-gap of the PbS QDs, a phase shift in an optically conveyed (at 1550 nm) microwave signal is produced. The strong light confinement produced in the ridge waveguides allows an improvement of the phase shift as compared to the case of planar structures. Moreover, a novel ridge bilayer waveguide composed by a PbS-SU8 nanocomposite and a SU8 passive layer is proposed to decrease the propagation losses of the pump beam and in consequence to improve the microwave phase shift up to 36.5° at 25 GHz. Experimental results are reproduced by a theoretical model based on the slow light effect produced in a semiconductor waveguide due to the coherent population oscillations. The resulting device shows potential benefits respect to the current MPS technologies since it allows a fast tunability of the phase shift and a high level of integration due to its small size.

How frequent is varicella-associated pneumonia in children?

Varicella is a frequent though mild infection in children, but it can cause important morbidity in adults. The most frequent complication in adults is varicella pneumonia. However, lower airway complications associated to varicella have been scarcely studied in children. We retrospectively reviewed the clinical records of the children hospitalized for varicella-associated pneumonia in the three public hospitals on the Island of Mallorca. We discovered that 17/213 (8%) children hospitalized for varicella were diagnosed of pneumonia. The rate of hospitalization for varicella complication due to pneumonia was 4.3 cases per 10,000 varicella infections. Only one patient was diagnosed of varicella pneumonia, which accounts for 0.3 cases per 10,000 varicella infections. Nine of 17 (53%) cases were classified as bacterial pneumonia. Statistical differences (p < 0.05) in the median time from rash (5.9 vs. 2.4 days) and fever (4.1 vs. 2.2 days) to admission were observed between bacterial and viral pneumonia. However, outcome differences measured by the median length of stay, need for oxygen, and admission to the intensive care unit were not observed. Varicella pneumonia is a very rare complication of varicella in children. Most of the lower airway infections in the course of varicella are associated to other co-infections.

[Acute obstructive renal failure secondary to retroperitoneal mass]

The acute renal failure is a grave pathology, of rapid establishment and relatively frequent in the hospital environment. We can describe three etiological groupS, which are responsible for it, amongst which are emphasized the pre-renal reasons. The obstructive pathology, of minor incidence, increases with the age. It is described the case of a 67-yr-old patient who was admitted in the Nephrology Service because of abrupt decline of the renal function. Among the initial symptoms, he presented arterial hypertension (190/90) and preserved diuresis. Blood analysis: urea 199 mg/dl, creatinine 7.7 mg/dl, without proteinuria. Sonography reported a bilateral ureteral hydronephrosis with simple cyst of possible ischemic origin. In view of the absence of previous biochemical data of renal failure, we considered possible reasons which start with an acute pattern. In initial evaluation, pre-renal etiology was not seen (high blood pressure, right cardiac systole function). The absence of prostatic syndrome and sonography discovery did not justify a diagnosis of urinary tract obstruction. Finally, abdominal-pelvic scan showed a periaortic retroperitoneal mass which included both ureters and appeared to trigger the obstruction. Combined efforts were pursued with the Urology Service, which implanted a bilateral "double J" catheter and later operated surgically on the patient, carrying out an alternating ureterolysis of both ureters. The biopsy manifested a retroperitoneal fibrosis, and the renogram showed a residual renal function of 20% in the right kidney and 80% in the left kidney. Due to the failure of the previous measures and as a last therapeutic recourse when one year had passed from the diagnosis, a continuous regimen with tamoxifen (anti-estrogen drug) in dose of 20 mg/dl each 12 hours was started, which began a progressive remission in the size of the observed mass by scan (CT) and magnetic resonance (MR). The treatment was completed during 12 months and in this time, the levels of blood urea nitrogen and creatinine were reduced gradually too. Finally, at the end of the treatment, the magnetic resonance demonstrate the complete disappearance of the fibrosis.

Reovirus infection in psittacine birds (Psittacus erithacus): morphologic and immunohistochemical study

In this paper we report on an outbreak of reovirus, herpesvirus (Pacheco disease), and/or mycosis infection (Aspergillus spp. and Zygomyces spp.) affecting a batch of young African grey parrots (Psittacus erithacus), with 80% morbidity and 30% mortality. Study material was taken from five birds (four dead and one euthanatized) with a range of clinical symptoms (depression, diarrhea, respiratory symptoms). Diagnosis was confirmed by immunohistochemical detection of avian reovirus, electron microscopy, and virus isolation. Viral antigen of reovirus was detected mainly in large mononuclear cells in the bursa of Fabricius and the spleen, pancreas epithelial cells, and circulating cells; lymphoid organs displayed the largest number of immunopositive cells and severe lymphocyte depletion. Bacteriologic study was negative. Reovirus infection was common in all birds studied, whereas Pacheco disease and mycosis were found in only some, suggesting that reovirus could be the initial cause triggering the outbreak and facilitating infection by other agents and their swift spread through the batch.

Hepatitis associated with herpes viral infection in the tortoise (Testudo horsfieldii)

Herpesvirus infection in tortoises is largely characterized by the development of respiratory clinical signs. Usually lesions develop in the respiratory, oral pharyngeal, intestinal tract and are accompanied by cutaneous and ocular lesions. In chelonids affected by herpesvirus, systemic-type lesions in organs such as the liver and spleen are commonly observed. In this paper we describe a case of multifocal necrotic hepatitis associated with herpesviruses in an adult female land tortoise of the species Testudo horsfieldii. This article is the first description of a viral hepatitis in Testudo spp. with lesions compatible with herpesvirus infection, with no clinical signs or lesions in the respiratory system, oral cavity or other organs.

Filamentous intranuclear inclusion bodies in psittacine birds. A structural and ultrastructural study

This paper concerns a disease affecting a group of African grey parrots, which involves intranuclear inclusion bodies composed of filamentous material. The disease was characterized by either sudden death or death within 2-3 days from onset of non-specific symptoms. At necropsy, gross lesions included enlarged liver, mild hepatic congestion and focal necrosis. Samples from five birds were fixed in 10% formol and routinely processed for light and electron microscopy. In four birds, numerous hepatocytes displayed an enlarged nucleus, with peripheral margination of chromatin; the nucleus was partially or wholly filled by a basophilic inclusion body. In the remaining bird, inclusion bodies were acidophilic and completely filled the nucleus; nuclear enlargement was less evident than in the other birds. At ultrastructural examination, and in both types of IIB, nuclei contained looped filaments but no evidence of viral structures. However, virion-like structures were observed in the cytoplasm of some hepatocytes.

Two cases of feline visceral and cutaneous leishmaniosis in Spain

This paper describes clinical signs and lesions in two cases of leishmaniosis--one visceral and one cutaneous in the cat (Felis catus domesticus). The diagnosis was achieved by a combination of serology, light and electron microscopic studies. The vague nature of the clinical signs observed in both cases was particularly striking, and clinical features were similar to many other diseases commonly found in cats. Therefore, the use of various investigations to detect leishmaniosis (serum chemistry, serology and histopathology) is highly recommended in cases where clinical signs do not respond to conventional treatment.

Myocarditis associated with Theileria spp. in calves

Two 3-week-old Limousin x Retinta calves from extensive farms in the south of Spain died suddenly. Microscopic examination of the spleen and lymph nodes revealed an intense lymphoid proliferation; the germinal centres were prominent and were surrounded by areas of haemorrhage. Parasitic forms, similar to Koch's bodies, were observed in only a small number of lymphoid cells and macrophages. In the myocardium a severe myocarditis was found. Inflammatory cells were in close contact with damaged myocytes, sometimes surrounding fragments of cells. In some areas the vessels had intraluminal deposits of fibrin. The endothelial damage and thrombosis may have contributed to the damage observed in the myocytes, together with the cytotoxic mechanism associated with the presence of an intense inflammatory infiltrate. The active multiplication of parasites may be due to the age of the animals and their breed, since they are not an autochthonous breed and present low resistance to infection.

Thrombocytopenia associated with apoptotic megakaryocytes in a viral haemorrhagic syndrome induced by a moderately virulent strain of African swine fever virus

A viral haemorrhagic syndrome was induced in 14 pigs by inoculation with an African swine fever (ASF) virus strain of moderate virulence, to determine changes in megakaryocyte (MK) numbers and morphology and thus to assess the role of these cells in the thrombocytopenia characteristic of subacute ASF. The strain tested induced changes in the proportion of different types of MK (typical nucleated MKs, apoptotic MKs and immature MKs); it also caused subcellular lesions over the first 7 days post-inoculation (dpi). At 7 dpi, severe thrombocytopenia was observed. There was a statistically significant increase in apoptotic MK numbers. The MKs showed three stages in the course of the disease: a compensatory stage, represented by cytoplasmic projections, a hypermaturity stage, represented by apoptotic MKs, and a regenerative stage, represented by clusters of immature MKs. These changes, especially the presence of numerous apoptotic MKs, may explain the early and transitory thrombocytopenia detected in subacute ASF. The large number of apoptotic MKs observed may be associated with the accelerated maturation of these cells, resulting from the action of cytokines, or peripheral platelet consumption, or both.

Integrated use of Landsat TM and SPOT panchromatic imagery for landslide mapping: case histories from southeast Spain

This paper demonstrates some of the ways in which digital space imagery can be used for landslide mapping. Landslides ranging in size from a few metres to several hundred metres across have been studied at a test site in semi-arid terrain in Almeria Province, SE Spain. The study illustrates the capabilities and limitations imposed by spatial and spectral resolution in Landsat Thematic Mapper (TM) and SPOT panchromatic space imagery. The results demonstrate the scales at which, landsliding which can be studied, using SPOT P and Landsat TM imagery.

Spectral and textural features of landslides were enhanced digitally. Textural discrimination was improved by linear contrast stretching combined with edge enhancement by adding back the results of Laplacian filtering. Spectral features of landslides, including soil moisture dependent vegetation and rock debris types, are well-displayed in supervised RGB colour composites and band ratio images.

A data integration technique, the Brovey Transformation, was used to produce colour composites combining textural and spectral features from SPOT Pan and Landsat TM imagery. Landslides with a minimum width of 250 metres can be identified in space images. Interpretation of results revealed the presence of several previously unrecorded landslides.

Daedalus 1268, Airborne Thematic Mapper (ATM) digital imagery has been used to demonstrate the value of improved spatial and spectral resolution imagery for landslide mapping on the scale of the Spanish test sites. The results illustrate the future system requirements for more detailed landslide mapping and demonstrate the improvements of scale which will occur when space imagery with pixel sizes of five metres becomes more readily available.

Abnormal antler growth associated with testicular hypogonadism in red deer

A wild 5-yr-old red deer (Cervus elaphus) was eulled from a privately owned herd because of deformed antlers, retained velvet and bilateral symmetrical testicular hypogonadism. The clinical and pathological changes seen in this deer were most consistent with congenital hypoplasia, but testicular atrophy was an alternative possibility for the etiology of their condition.

Canine cutaneous protothecosis: an immunohistochemical analysis of the inflammatory cellular infiltrate

In this immunohistochemical study, the distribution of the cellular inflammatory infiltrate associated with cutaneous canine protothecosis (Prototheca wickerhamii) was evaluated by consecutive biopsies taken before, during and after treatment. Antibodies specific to canine immunoglobulins (IgG, IgM, IgA), human CD3 antigen (pan T-lymphocyte marker) and human myeloid/ histiocyte antigen (macrophage/neutrophil marker) were used. Before treatment, cellular infiltrate was very scanty in the inflamed areas, but it increased during the treatment, whereas the number of protothecal organisms decreased. Statistical analysis revealed an inverse relation between the number of protothecal organisms and the number of infiltrating macrophage/neutrophils (P < 0.004), T lymphocytes (P < 0.001), and cells containing immunoglobulin G (P < 0.001), M (P < 0.001) and A (P < 0.001) at different stages of the disease. These findings suggest either that protothecal organisms inhibit the migration or proliferation of cellular inflammatory infiltrate or that only dead protothecal organisms induce an effective local immune response.

Focal mesangial-sclerosing glomerulonephritis and acute-spontaneous infectious canine hepatitis: structural, immunohistochemical and subcellular studies

The glomerular alterations observed in a dog with acute spontaneous infectious canine hepatitis (ICH) are described. Histologic changes of the glomeruli were enlargement of the mesangium with presence of intranuclear inclusion bodies and without proliferation of mesangial cells. Electron microscopy revealed adenovirus replication sites in glomerular mesangial cells and in endothelial cells of glomerular capillaries, as well as a focal mesangial-sclerosing glomerulonephritis associated with electron dense deposits which were closely related with extracellular ICH viral particles and immunohistochemically reactive for immunoglobulin (Ig) G, IgA, IgM and C3c complement components.

Effects of fluoxetine hydrochloride and fluvoxamine maleate on different preparations of isolated guinea pig and rat organ tissues

1. Fluoxetine and fluvoxamine reinforced the response to norepinephrine of isolated rat vas deferens incubated in Krebs-Henseleit solution. 2. This reinforcement disappeared when cocaine, 17 beta-estradiol, and propranolol were added to the incubation medium. 3. Fluoxetine and fluvoxamine did not have antimuscarinic effect, but they did have antihistaminic effect, and at high concentrations they inhibited the contraction induced by potassium ion on the isolated rat uterus preparation (IC50 3.99 x 10(-6) and 1.82 x 10(-5) M, respectively).

Ultrastructural findings in natural canine hepatozoonosis

The ultrastructure of several stages of Hepatozoon canis found in dogs with clinically and histologically diagnosed infections was determined using transmission electron microscopy. Merozoites, macro- and microschizonts and gamonts were found in spleen, liver, kidneys and lungs. Macro- and micromeronts were characterized by their size and by the presence of intracytoplasmic amylopectin granules. Gamonts, which provide the basis for clinical diagnosis of the disease, were observed within mononuclear cells (monocytes/macrophages); they were butterfly-shaped and exhibited varying electron densities. On the basis of the microscopic observations reported here, it is clear that the life cycle of H. canis is a complex one.

African swine fever virus infection of bone marrow: lesions and pathogenesis

The effects of African swine fever (ASF) virus infection on bone marrow hematopoiesis and microenvironment were determined by studying the sequential development of ultrastructural lesions of bone marrow and blood cell changes. Eight pigs (two pigs/infected group) were inoculated by intramuscular route with 10(5) 50% hemadsorbing doses (HAD50) of the Malawi'83 ASF virus isolate. Two uninfected pigs were used as controls. Ultrastructural changes developed by day 3 postinoculation (PI), persisted through day 7 PI, and were characterized by activation of macrophages. From day 5 PI, viral replication was observed in monocytes/macrophages, reticular cells, immature neutrophils, and promonocytes. Also viral replication was detected in megakaryocytes, endothelial cells, and pericytes at day 7 PI. Vascular alterations consisted of activation of sinusoidal endothelial cells, intravascular coagulation, and fibrin strands interspersed among microenvironment and hematopoietic cells. No significant changes were observed in total white blood cells counts, percentage of monocytes, and platelet counts; however, severe lymphopenia and neutrophilia were detected from day 3 PI. Results of this experiment indicate that there is increased hematopoiesis in bone marrow during acute ASF, coinciding with macrophage activation. Neither vascular changes nor viral replication in different bone marrow cell populations gave rise to impaired bone marrow function. Increased hematopoiesis would exert a positive influence by preventing the early onset of thrombocytopenia and would exert a negative influence by stimulating the spread of the virus via neutrophils. Increased hematopoiesis would be unable to compensate for the lymphopenia.

Subcellular changes in the tonsils of pigs infected with acute African swine fever virus

A study of the pathogenesis of acute African swine fever (ASF) was carried out in pigs inoculated with a highly virulent strain of ASF virus to determine the sequential development of the subcellular changes in a particular lymphoepithelial organ, the tonsil. The apoptosis of the lymphocytes and the inhibition of lymphocyte proliferation were the main changes that occurred in the tonsillar lymphoid structures. This may explain the early lymphopenia observed in acute ASF. Moreover, vascular changes, consisting of increased vascular permeability, activation of endothelial cells and loss of these cells, might have been the cause of the characteristic haemorrhages found in the lymphoid organs during this disease. Virus replication has been observed in the epithelial cells, fibroblasts and reticular cell beginning on day 5 post-infection. The activation of the endothelial cells, apoptosis of lymphocytes, decreased lymphocyte mitosis and virus replication in non-mononuclear phagocyte system (MPS) cells all occurred after an intense proliferation and activation of the tonsillar macrophages and coincide with virus replication, which occurs in the macrophages 5 days post infection.

Subcellular changes in platelets in acute and subacute African swine fever

The morphological changes in platelets in acute and subacute African swine fever (ASF) and their relationship to pathogenesis were studied. Eight pigs were inoculated with a highly virulent strain of African swine fever (Malawi '83) and 14 with a moderately virulent strain (Dominican Republic '78) for ultrastructural study of platelets, monocyte/macrophages and vascular structures in the liver, spleen, lymph node, bone marrow, lung and kidney. Both viruses produced activation and degranulation of platelets from day 3 after inoculation onwards, coinciding with activation of the mononuclear phagocyte system and virus replication in monocyte/macrophages. Platelet aggregation and viscous metamorphosis of platelets were observed at 5 and 7 days after inoculation with the highly virulent strain, coinciding with endothelial alterations, but platelet aggregation was less prevalent and there was no sign of viscous metamorphosis in animals inoculated with the moderately virulent strain. Virions within platelets were observed at the final stage of acute ASF and at 5-7 days after inoculation in subacute ASF. This suggests that platelets assist in disseminating ASF virus within the body, especially in subacute infections.

Effect of several antidepressant drugs on isolated rat vas deferens in vitro

Imipramine-N-oxide, quinupramine, clomipramine, doxepin, maprotiline, amineptine, amoxapine, mianserin, minaprine, nomifensine, viloxacine, trazodone and lofepramine effects were studied on rat vas deferens responses to noradrenaline. Tissues were prepared in Krebs-Henseleit solution with and without adding cocaine. 17 beta-estradiol and propranolol for blocking neuronal and extraneuronal noradrenaline reuptake. In normal Krebs-Henseleit solution imipramine-N-oxide, nomifensine, viloxacine and lofepramine increased noradrenaline responses, while clomipramine, trazodone and doxepin behaved as competitive antagonists. When adding cocaine, 17 beta-estradiol and propranolol to the solution there was antagonism but no increase in responses.

Structural and ultrastructural study of glomerular changes in African swine fever

The pathological effect of haemorrhagic fever viruses on the kidney have not been clearly documented. This study reports glomerular lesions in African swine fever. In the acute form of the disease there was an acute diffuse proliferative glomerulonephritis, which was believed to be related to virus replication in circulating monocytes and glomerular mesangial cells, and to the presence of abundant circulating cell debris resulting from viral replication at other sites. In the subacute form, the proliferative mesangial glomerulonephritis observed may have been associated with systemic immune-mediated phenomena, and with subendothelial and mesangial deposits of immunoglobulins and complement components.

The lesional changes and pathogenesis in the kidney in African swine fever

African swine fever is a viral haemorrhagic disease of pigs which has been used as a model for the study of viral haemorrhagic diseases in man. The acute course of the disease is characterized by acute proliferative glomerulonephritis, with viral replication in mesangial cells and occasional focal necrosis of the renal tubular system; hyperplasia of the collecting ducts is associated with evident virus replication. Haemorrhages have been attributed to endothelial dysfunction, aggravated by virus replication in endothelial cells in the final stages of the disease. The renal interstitium displays intense oedema and an infiltrate largely composed of macrophages. Virus replication has also been observed in fibroblasts and in the smooth-muscle cells of arterioles and venules. In subacute-chronic forms of the disease, various types of glomerulonephritis are observed, ranging from mesangial proliferative glomerulonephritis to focal and segmental hyalinosis associated with immune-mediated phenomena. No striking changes are reported in the renal tubular system. Interstitial haemorrhages are associated with diapedesis due to immunologically mediated events. The interstitium has also been found to contain a lymphohistiocytic infiltrate with abundant plasma cells. No evidence has been reported of viral replication in any cell population.

[Ostertagiasis in bulls used for bullfights]

In this paper, an outbreak of ostertagiosis in fighting-bull calves is described. Of 95 calves, 12 were affected and 10 died. Grossly, the abomasal mucosa was aedematous and showed multiple whitish tiny nodules. Differential diagnoses at a macroscopic level included parasitization by E. gilruthi. However, histologically the presence of Ostertagia spp. larvae in the lumen of the gastric glands was confirmed. The inflammatory reaction observed in the abomasal mucosa, together with the clinical picture, correspond to type-II ostertagiosis, with metaplasia, hyperplasia, dilatation, and parasitic forms in the gastric glands.

Electron microscopic evidence for infection of splenic dendritic cells by adenovirus in psittacine birds

The spleens of four psittacine birds suffering from natural type II avian adenoviral infection were studied by histopathological, immunohistochemical and ultrastructural techniques to determine the target cells of this virus in the spleen. Typical adenoviral replication sites were found in lymphocytes and dendritic cells.

A pathological study of the perisinusoidal unit of the liver in acute African swine fever

African swine fever is an acute haemorrhagic disease of pigs which may serve as a model for the study of the pathogenesis of other viral haemorrhagic fevers. This paper describes an ultrastructural study of the sequence of lesions produced in the perisinusoidal functional unit of the liver of pigs inoculated with the Malawi '83 strain of African swine fever virus, which is classified as haemadsorbing and highly virulent. Virus replication was observed in Kupffer cells and monocytes from three days after inoculation, in hepatocytes and fat-storing cells at five and seven days after inoculation, and in sinusoidal endothelial cells at seven days after inoculation. Further observations included intravascular coagulation, which peaked at five days after inoculation, and fibroblast and myofibroblast transformation of fat-storing cells at seven days after inoculation. These results suggest that activated cells of the mononuclear phagocyte system may play a major role in this sequence of lesions and the possible role of the cytokines that may be released by these cells is discussed.

Experimental African swine fever: apoptosis of lymphocytes and virus replication in other cells

In order to determine the cause of cellular death of lymphocytes in pigs with acute African swine fever and the relationships between African swine fever virus (ASFV) and interstitial cells, ten pigs were inoculated with a highly virulent strain of ASFV (Malawi '83) and samples taken for ultrastructural study of hepatic and renal interstitial tissues. We demonstrated death by apoptosis of lymphocytes and virus replication in fibroblasts, smooth muscle cells and endothelial cells in the interstitial tissues of pigs inoculated with ASFV. From day 5 onwards, apoptotic lymphocyte and intense virus replication in hepatic interstitial macrophages and fibroblasts were observed. By day 7, apoptotic lymphocytes and virus replication in macrophages, interstitial capillary endothelial cells and fibroblasts in the kidney were observed. Virus replication was also seen in smooth muscle cells of hepatic and renal arterioles and venules. Our results suggest that mononuclear phagocyte system (MPS) cell activation, and the resulting release of cytokines, could induce apoptosis of lymphocytes and virus replication in non-MPS cells.

Pathological changes in the renal interstitial capillaries of pigs inoculated with two different strains of African swine fever virus

African swine fever is a viral disease of pigs characterized predominantly by haemorrhagic lesions. This paper reports the lesions observed in the renal interstitial capillaries of pigs inoculated with African swine fever virus strains of differing virulence: the Malawi'83 strain (haemadsorbent and highly virulent) and the Dominican Republic'78 strain (haemadsorbent and moderately virulent). In pigs infected with the Malawi'83 strain, petechial haemorrhages and microhaemorrhages were observed 5 days after inoculation and lesions were evident in the renal capillaries. Signs of phagocyte activation were noticeable in endothelial cells, with enlarged fenestrations and even loss of endothelium, leaving the basement membrane of the vessels exposed. Platelet plugs and microthrombi were also observed in these vessels. At 7 days after inoculation these lesions had intensified, and were accompanied by virus replication in the endothelial cells. In pigs infected with the Dominican Republic'78 strain, haemorrhages were more abundant and more extensive, and although no endothelial cell lesions were observed, there was intense vasodilation with diapedesis of erythrocytes.

Ultrastructural study of the renal tubular system in acute experimental African swine fever: virus replication in glomerular mesangial cells and in the collecting ducts

Despite the considerable attention given to kidney lesions in African swine fever (ASF), a number of questions remain to be answered. Structural and ultrastructural examination showed that a highly virulent isolate of ASF virus (Malawi 83) replicated in glomerular mesangial cells and renal collecting duct epithelial cells, with hyperplasia of the latter in infected pigs. Replication in mesangial cells may be due to their contact with the bloodstream, as well as to their phagocytic capacity and high metabolism rate. Virus replication in macrophages and endothelial cells of interstitial capillaries, and the necrosis of these infected cells gave rise to a large number of free virus in interstitial tissue. This, together with the lesser thickness of the basal membrane of collecting ducts in comparison to the rest of the tubular system, probably facilitates ASFV infection of tubular epithelial cells. Virus replication in these cells may account for the presence of virus in the urine of pigs with acute ASF where haematuria is not observed.

The role of fibrinolysis in the pathogenesis of the haemorrhagic syndrome produced by virulent isolates of African swine fever virus

The activity of several proteins involved in fibrinolysis and the morphological changes in the blood vessel walls of pigs infected with highly virulent (Malawi'83) and moderately virulent (Dominican Republic '78-DR'78) ASF virus isolates were determined. Pigs infected with the Malawi'83 virus developed an increased fibrinolytic activity due to high plasma levels of tissue-plasminogen activator (t-PA) of 71.3 +/- 22.8 IU/ml (mean +/- SD), which correlated well with an increased activation of interstitial capillary endothelial cells and high levels of 1150 +/- 73.6 nM of fibrin monomer in the circulation. Animals infected with DR'78 virus, in contrast, showed an inhibition of fibrinolysis in the late stages of disease with almost a 5-fold increase of plasminogen activator inhibitor (PAI) activity of 196.0 AU/ml. These results suggest that activation of the fibrinolytic system in pigs infected with the Malawi'83 virus is probably due to increased formation and deposition of fibrin in the circulation, contributing to an increased bleeding tendency and higher mortality. On the contrary, animals infected with DR'78 virus developed an inhibition of fibrinolysis and thus a reduction in bleeding.

[Differential clinical characteristics among pediatric patients with gastroenteritis caused by rotavirus and adenovirus]

BACKGROUND

The differential clinical and epidemiological characteristics of pediatric patients (< 14 years) with gastroenteritis caused by rotavirus or adenovirus were studied.

MATERIAL AND PATIENTS

A retrospective study was performed in patients with viral gastroenteritis diagnosed from January 1990 to December 1992. The detection of viral particles was carried out by the agglutination system with latex particles sensitized with antibodies versus rotavirus and adenovirus. Clinical and epidemiological characteristics of the patients were collected reviewing the medical records and emergency charts.

RESULTS

Two hundred eighty-nine patients corresponding to 240 cases of infection by rotavirus (83.1%) and 48 (16.9%) by adenovirus, were analyzed. Diarrhea by rotavirus predominated in the winter months (59.7% of the cases from December to March). Nonetheless, those caused by adenovirus were seen throughout the year with a stable incidence being observed. Statistically significant differences were seen in both groups (p < 0.001) with rotavirus infection having a greater tendency to admission and greater incidence of vomiting, fever (> 39 degrees C) and underlying disease. The presence of leukocytosis was different in the adenovirus group as were the greater length of duration of diarrhea prior to attending the Emergency Department (5.2 days) and the total length of stay (11.2 days). No other associated enteropathogenic organisms were detected in 86.3% of the infections by rotavirus and in the 89.8% of those caused by adenovirus. In regard to age group distribution prevalence of diarrhea by rotavirus was observed during the first 3 months of life (76.6%) while adenovirus group it went up to 24 months of age with similar percentages.

CONCLUSIONS

Diarrhea by rotavirus is mainly presented in the winter, with vomiting and its shorter in length and the symptoms less prolonged than diarrhea caused by adenovirus. Rotavirus diarrhea generally affect patients admitted with some underlying disease. Nonetheless, microbiologic diagnosis is required to establish the definitive etiology of both clinical processes.

Hemorrhagic enteritis by adenovirus-like particles in turkeys: a possible pathogenic mechanism

This paper describes an outbreak of hemorrhagic enteritis due to adenovirus in turkeys in Spain. Diagnosis of the disease was confirmed by histopathological examination and the observation of adenovirus in spleen mononuclear cells and intestinal infiltrate. Evidence was also found of intravascular coagulation, which may give rise to the bleeding considered characteristic of this disease.

[Clinical and microbiologic characteristics of 282 pediatric patients with mesophilic Aeromonas isolated from feces]

BACKGROUND

The aim of the study was to assess the microbiological characteristics and the clinical aspects of pediatric patients (age < 14 years) with infectious diarrhea due to one of the species included among the mesophilic Aeromonas group (AMs) from January 1989 to December 1991.

METHODS

The samples (stools) were processed following the routine methodology recommended. For isolation of AMs the XDCA medium was used and identification of species was performed by gas production tests from glucose and esculin hydrolysis. Clinical and epidemiologic features were recorded by means of a retrospective analysis of the clinical histories.

RESULTS

In 30.3% of the 7,653 stool-cultures studied, an enteropathogenic microorganism identified as S. enterica (I) was isolated in 979 (12.8%), 536 cases to Campylobacter sp. (7.0%) infection, 58 to Shigella sp. (0.7%), 56 to Y. enterocolitica (0.7%, 221 to rotavirus (2.8%) and 49 to adenovirus (0.6%) The presence of AMs was detected in 282 patients (3.7%), representing 12% of the all positive stool-cultures. The species isolated were A. caviae (54.9%), A. sobria (21.9%) and A. hydrophila (23.1%). In 56% of the cases the AMs were isolated as the single pathogen. Thirty-nine point seven percent of the isolations were performed in patients aged less than 12 months (17% with less than 3 months). The A. caviae species was found to be predominant among the breast-fed babies (51.7%). Seventy percent of the children of 0-3 months presented A. caviae as unique pathogen. A total of 84.3% of the children infected with A. caviae, had been or were being fed with artificial lactation. AMs predominated in the late summer-early fall months (August-October) reading the maximum rate of isolations in these months (35.3 cases/month).

CONCLUSIONS

Infections gastroenteritis due to mesophilic Aeromonas in the authors' geographic area appears to affect males mainly, and presents as an acute self-limited diarrhea, community-acquired. The predominance of A. caviae during the lactation period and in the first three months of life are data which should be further considered and confirmed.

[Hypothalamo-hypophyseo-gonadal axis in individuals with chronic renal insufficiency subjected to hemodialysis]

The role of pituitary and sexual hormones in 21 patients with chronic renal failure (CRF) and related impotence and loss of libido who were being treated by hemodialysis and in 15 normal male controls has been studied. In both groups the serum levels of FSH, LH and TSH, PRL before and after injection of both LHRH and TRH were measured as well as the basal levels of Testosterone (T) and Estradiol (E2). The results show similar values for testosterone in both groups and statistically significant higher basal values for FSH, LH, TSH and PRL and lower basal values for E2 in CRF patients.