Rendu-Osler-Weber syndrome: what radiologists should know. Literature review and three cases report

Rendu-Osler-Weber syndrome or hereditary hemorrhagic telangiectasia is an autosomal dominant vascular disease involving multiple systems whose main pathological change is the presence of abnormal arteriovenous communications. Most common symptoms include skin and mucosal telangiectasias, epistaxis, gastrointestinal, pulmonary and intracerebral bleeding. The key imaging finding is the presence of visceral arteriovenous malformations. The diagnosis is based on clinical criteria and can be confirmed by molecular biology techniques. Treatment includes measures for management of epistaxis, as well as surgical excision, radiotherapy and embolization of arteriovenous malformations, with emphasis on endovascular treatment. The present pictorial essay includes a report of three typical cases of this entity and a literature review.

Ablação de tumor de canal anal tratado com laser de diodo: seguimento após 17 meses

The Nd:YAG laser is used as the palliative treatment of obstructive and/or hemorrhagic intestinal lesions with an effective but temporary symptomatic relief, with symptoms and signs recurrence after six to eight weeks. This report describes the treatment of a patient bearing a low rectal adenocarcinoma through diode laser ablation and the result after 17 months.

Transoperative refusion: a simple and safe method in emergency surgery

The objective is to reinforce the importance of blood reinfusion as a cheap, safe and simple method, which can be used in small hospitals, especially those in which there is no blood bank. Moreover, even with the use of devices that perform the collection and filtration of blood, more recent studies show that the cost-benefit ratio is much better when autologous transfusion is compared with blood transfusions, even when there is injury to hollow viscera and blood contamination. It is known that the allogeneic blood transfusion carries a number of risks to patients, among them are the coagulation disorders mediated by excess enzymes in the conserved blood, and deficiency in clotting factors, mainly the Factor V, the proacelerin. Another factor would be the risk of contamination with still unknown pathogens or that are not investigated during screening for selection of donors, such as the West Nile Fever and Creutzfeldt-Jacob, better known as "Mad Cow" disease. Comparing both methods, we conclude that blood autotransfusion has numerous advantages over heterologous transfusion, even in large hospitals. We are not against blood transfusions, just do not agree that the patient's own blood is discarded without making sure there will be enough blood in stock to get him out of the hemorrhagic shock.

Necrotizing enteritis associated with Clostridium perfringensType B in chinchillas (Chinchilla lanigera)

Four 3-4 month-old chinchillas (Chinchilla lanigera) from a commercial flock of 395 chinchillas, were found dead with evidence of previous diarrhea and prolapsed rectum. A fifth 8 month-old chinchilla died 8 hours after being found recumbent, apathetic, diarrheic and with a prolapsed rectum. Two chinchillas were necropsied and observed gross lesions consisted of extensive hemorrhagic enteritis, mild pulmonary edema and enlarged and yellow liver; this latter finding was particularly prominent in the chinchilla presenting longer clinical course. Histologically there was necrotizing enteritis associated with abundant bacterial rods aggregates in the intestinal surface epithelium and within the lamina propria. In the lungs there were small amounts of pink proteinaceous material (edema) in the interstitium and marked vacuolar hepatocellullar degeneration (lipidosis) in the liver. Anaerobic cultures from the intestinal contents of one of the affected chinchillas yielded Clostridium perfringens. Genotyping of this C. perfringens isolate was achieved by multiplex polymerase chain reaction (mPCR) as C. perfringenstype B due to detection of alpha, beta and epsilon-toxin genes. These findings suggest C. perfringens type B as an important cause of sudden or acute death in chinchillas.

Contracaecum pelagicum and C. plagiaticium (Nematoda: Anisakidae) infection in Magellanic penguins (Sphenisciformes: Spheniscidae) on the coast of Rio de Janeiro State

The occurrence of infections and the disease induced by Contracaecum plagiaticium and Contracaecum pelagicum in Magellanic penguins, Spheniscus magellanicus Foster. 1781 (Sphenisciformes: Spheniscidae) were reported on the coast of Rio de Janeiro. Parasites of the genus Contracaecum were present in all of the 11 studied animals. Co-infections by Csontracaecum pelagicum and C. plagiaticium were observed in three hosts (27.27%). Gross lesions included hyperemia of the esophagus and/or stomach in six animals (54.54%). One of these animals (9.09%), parasitized by C. plagiaticium, presented a hemorrhagic area in the gastric mucosa. Histopathological findings demonstrated esophagitis with helminthes segments inserted in the epithelium, showing discrete mixed inflammatory infiltrate of heterophils and mononuclear cells. These parasites may be associated with other diseases, implicating in death of the penguins.

A phylogenetic study of canine parvovirus type 2c in midwestern Brazil

Since the late 1970s, canine parvovirus type 2 (CPV-2) has emerged as a causative agent of fatal severe acute hemorrhagic enteritis in dogs. To date, three antigenic types of CPV-2 were described worldwide (CPV-2a/b/c). This study was conducted to determine the variants of CPV-2 circulating in dogs from the Cuiabá Municipality in Midwestern Brazil. Out of 50 fecal samples, collected between 2009 and 2011, 27 tested positive for CPV-2. A 583 bp fragment of the VP2 gene was amplified by PCR, 13 representative samples were analyzed further by DNA sequencing. All strains were characterized as CPV-2c, displayed a low genetic variability although observed several amino acid substitution. These findings indicated that CPV-2c has been circulating in dogs from the Cuiabá Municipality in Midwestern Brazil.

Acute fasciolosis in cattle in southern Brazil

This study describes the epidemiological and pathological aspects of an outbreak of acute fasciolosis in cattle in southern Brazil. Fifteen out of 70 three-year-old pregnant cows lost weight in the 30-40 days prior to calving. Clinical signs included diarrhea, weakness, mild anemia and jaundice. Dark yellow fluid in the abdominal cavity was observed at necropsy. Fibrin and clotted blood were adhered to the pericardium and lung, primarily in the diaphragmatic lobes. The liver was enlarged, and the capsular surface was irregular with clear areas and petechiae. At the cut surface, the liver was irregular, firm and edematous, and several hemorrhagic channels could be observed. Areas of fibrosis through the parenchyma and whitish thrombi occluding the great vessels were also observed. The livers of 10 cows that not died were condemned at slaughter for lesions of fasciolosis similar to those observed at necropsy. Microscopically, the liver showed areas of coagulation necrosis, extensive hemorrhages in the streaks or foci and disruption of the parenchyma with neutrophil and eosinophil infiltration. Fibrosis and bile duct proliferation were also observed. Immature Fasciola hepatica flukes were observed in the parenchyma surrounded by degenerated hepatocytes, neutrophils, eosinophils, and hemorrhages. The outbreak occurred on a farm located in an area endemic for fasciolosis, although the acute form of the disease is not common in cattle in this region. It is likely that the cows were infected by F. hepatica metacercariae released in the late fall or early spring in the rice stubble where the herd was grazing prior to calving. Although mortality due to fasciolosis in cattle is infrequent, outbreaks can occur and treatments that are effective in both the immature and adult forms of the parasite should be administered to prevent economic losses.

Enterohemorrhagic Escherichia coli O157: H7 from healthy dairy cattle in Mid-West Brazil: occurrence and molecular characterization

Enterohemorrhagic Escherichia coli (EHEC) serotype O157:H7 represents the major Shiga toxin-producing E. coli (STEC) strain related to large outbreaks and severe diseases such as hemorrhagic colitis (HC) and the potentially lethal hemolytic uremic syndrome (HUS). The aim of this study was to report the occurrence and molecular characterization of O157:H7 isolates obtained by rectal swab from 52 healthy dairy cattle belonging to 21 farms in Mid-West of Brazil. Detection of 16SrRNA, stx1, stx2, rfbO157, fliCh7, eae, ehxA, saa, cnf1, chuA, yjaA and TSPE4.C2 genes was performed by PCR. The isolates were further characterized by serotyping. Two hundred and sixty E. coli isolates were obtained, of which 126 were characterized as STEC. Two isolates from the same cow were identified as serotype O157:H7. Both isolates presented the stx2, eae, ehxA, saa and cnf1 virulence factor genes and the chuA gene in the phylogenetic classification (virulent group D), suggesting that they were clones. The prevalence of O157:H7 was found to be 1.92% (1/52 animals), demonstrating that healthy dairy cattle from farms in the Mid-West of Brazil are an important reservoir for highly pathogenic E. coli O157:H7.

Neutralizing capacity of a new monovalent anti-Bothrops atrox antivenom: comparison with two commercial antivenoms

Three horse-derived antivenoms were tested for their ability to neutralize lethal, hemorrhagic, edema-forming, defibrinating and myotoxic activities induced by the venom of Bothrops atrox from Antioquia and Chocó (Colombia). The following antivenoms were used: a) polyvalent (crotaline) antivenom produced by Instituto Clodomiro Picado (Costa Rica), b) monovalent antibothropic antivenom produced by Instituto Nacional de Salud-INS (Bogotá), and c) a new monovalent anti-B. atrox antivenom produced with the venom of B. atrox from Antioquia and Chocó. The three antivenoms neutralized all toxic activities tested albeit with different potencies. The new monovalent anti-B. atrox antivenom showed the highest neutralizing ability against edema-forming and defibrinating effects of B. atrox venom (41 ± 2 and 100 ± 32 µl antivenom/mg venom, respectively), suggesting that it should be useful in the treatment of B. atrox envenomation in Antioquia and Chocó

Application of various antioxidants in the treatment of influenza

We determined the effect of the antioxidants superoxide dismutase, desferrioxamine and allopurinol on the survival of male CBA mice infected intranasally with 2-5 LD50 lung influenza virus A/Aichi/2/68. Survival for at least 20 days was observed for 45% of the mice that received 1000 U/day superoxide dismutase prepared from red blood cells on days 5, 6, 7 and 8 after infection, and 75% survival was observed for mice that received the same dose on days 4, 5, 6, 7 and 8. Desferrioxamine, 25 mg/kg per day and 100 mg/kg per day injected subcutaneously, resulted in survival rates of 5 and 0%, respectively, compared to 10% survival observed for saline-injected controls. Allopurinol at doses of 5 to 50 mg/kg per day had no effect on mouse survival. These data demonstrate the efficacy of superoxide dismutase for the protection of mice against hemorrhagic lung edema. The ineffectiveness of allopurinol suggests that the xanthine oxidase system does not play a major role in hemorrhage or lung edema and that caution is necessary when desferrioxamine is administered during an acute inflammatory process accompanied by erythrocyte lysis

Towards understanding the kallikrein-kinin system: insights from measurement of kinin peptides

The kallikrein-kinin system is complex, with several bioactive peptides that are formed in many different compartments. Kinin peptides are implicated in many physiological and pathological processes including the regulation of blood pressure and sodium homeostasis, inflammatory processes, and the cardioprotective effects of preconditioning. We established a methodology for the measurement of individual kinin peptides in order to study the function of the kallikrein-kinin system. The levels of kinin peptides in tissues were higher than in blood, confirming the primary tissue localization of the kallikrein-kinin system. Moreover, the separate measurement of bradykinin and kallidin peptides in man demonstrated the differential regulation of the plasma and tissue kallikrein-kinin systems, respectively. Kinin peptide levels were increased in the heart of rats with myocardial infarction, in tissues of diabetic and spontaneously hypertensive rats, and in urine of patients with interstitial cystitis, suggesting a role for kinin peptides in the pathogenesis of these conditions. By contrast, blood levels of kallidin, but not bradykinin, peptides were suppressed in patients with severe cardiac failure, suggesting that the activity of the tissue kallikrein-kinin system may be suppressed in this condition. Both angiotensin converting enzyme (ACE) and neutral endopeptidase (NEP) inhibitors increased bradykinin peptide levels. ACE and NEP inhibitors had different effects on kinin peptide levels in blood, urine, and tissues, which may be accounted for by the differential contributions of ACE and NEP to kinin peptide metabolism in the multiple compartments in which kinin peptide generation occurs. Measurement of the levels of individual kinin peptides has given important information about the operation of the kallikrein-kinin system and its role in physiology and disease states.

Antithrombotic effect of Lonomia obliqua caterpillar bristle extract on experimental venous thrombosis

The venom of Lonomia obliqua caterpillar may induce a hemorrhagic syndrome in humans, and blood incoagulability by afibrinogenemia when intravenously injected in laboratory animals. The possible antithrombotic and thrombolytic activities of L. obliqua caterpillar bristle extract (LOCBE) were evaluated in this study. The minimal intravenous dose of the extract necessary to induce afibrinogenemia and anticoagulation was 3.0 and 10.0 µg protein/kg body weight for rabbits and rats, respectively. In rabbits, this dose induced total blood incoagulability for at least 10 h and did not reduce the weight of preformed venous thrombi, in contrast to streptokinase (30,000 IU/kg). In rats, pretreatment with 5.0 and 10.0 µg/kg LOCBE prevented the formation of thrombi induced by venous stasis or by injury to the venous endothelium. The dose of 5.0 µg/kg LOCBE did not modify blood coagulation assay parameters but increased bleeding time and decreased plasma factor XIII concentration. When the extract was administered to rats at the dose of 10.0 µg/kg, the blood was totally incoagulable for 6 h. These data show that LOCBE was effective in preventing experimental venous thrombosis in rats, justifying further studies using purified fractions of the extract to clarify the mechanisms of this effect.

Genetic characterization of dengue virus type 3 isolates in the State of Rio de Janeiro, 2001

The genetic characterization of dengue virus type 3 (DEN-3) strains isolated from autochthonous cases in the State of Rio de Janeiro, Brazil, in 2001 is presented. Restriction site-specific (RSS)-PCR performed on 22 strains classified the Brazilian DEN-3 viruses as subtype C, a subtype that contains viruses from Sri Lanka, India, Africa and recent isolates from Central America. Nucleic acid sequencing (positions 278 to 2550) of one DEN-3 strain confirmed the origin of these strains, since genotype III - classified by sequencing - and RSS-PCR subtype C are correlated. This genetic subtype has been associated with hemorrhagic dengue epidemics and the information provided here could be useful to implement appropriate prevention and control measures.

The Shiga toxin 2 B subunit inhibits net fluid absorption in human colon and elicits fluid accumulation in rat colon loops

Shiga toxin (Stx)-producing Escherichia coli (STEC) colonizes the large intestine causing a spectrum of disorders, including watery diarrhea, bloody diarrhea (hemorrhagic colitis), and hemolytic-uremic syndrome. It is estimated that hemolytic-uremic syndrome is the most common cause of acute renal failure in infants in Argentina. Stx is a multimeric toxin composed of one A subunit and five B subunits. In this study we demonstrate that the Stx2 B subunit inhibits the water absorption (Jw) across the human and rat colonic mucosa without altering the electrical parameters measured as transepithelial potential difference and short circuit current. The time-course Jw inhibition by 400 ng/ml purified Stx2 B subunit was similar to that obtained using 12 ng/ml Stx2 holotoxin suggesting that both, A and B subunits of Stx2 contributed to inhibit the Jw. Moreover, non-hemorrhagic fluid accumulation was observed in rat colon loops after 16 h of treatment with 3 and 30 ng/ml Stx2 B subunit. These changes indicate that Stx2 B subunit induces fluid accumulation independently of A subunit activity by altering the usual balance of intestinal absorption and secretion toward net secretion. In conclusion, our results suggest that the Stx2 B subunit, which is non-toxic for Vero cells, may contribute to the watery diarrhea observed in STEC infection. Further studies will be necessary to determine whether the toxicity of Stx2 B subunit may have pathogenic consequences when it is used as a component in an acellular STEC vaccine or as a vector in cancer vaccines.

Laminin concentration in ascites of patients with hepatic cirrhosis and peritoneal carcinomatosis

Laminin levels in ascitic fluid have been proposed as a marker for neoplastic ascites. We compared the concentration of laminin in serum and in ascitic fluid from patients with hepatic cirrhosis and peritoneal carcinomatosis and assessed the diagnostic value of serum laminin levels in differentiating neoplastic from benign ascites. Laminin concentrations were determined by ELISA with antibodies against laminin extracted from the human placenta, in patients with ascites due to peritoneal carcinomatosis (N = 20) and hepatic cirrhosis (N = 33). Patients with infected or hemorrhagic ascites were excluded. The receiver operating characteristic curve was used to determine the sensitivity and specificity of serum laminin for the diagnosis of neoplastic ascites. When compared to the group with cirrhosis, the carcinomatosis group presented significantly higher mean laminin levels in serum (3.3 ± 0.5 vs 2.1 ± 0.4 µg/ml, mean ± SD, P < 0.05) and ascites (2.8 ± 0.5 vs 1.6 ± 0.4 µg/ml, P < 0.05). Although laminin concentration was higher in serum than in ascites, the laminin serum/ascites ratio and serum-ascites gradient did not differ between the studied groups. A significant correlation (r = 0.93, P < 0.0001) was observed between the serum and ascites laminin values. Serum laminin levels >2.25 µg/ml showed 100% sensitivity and 73% specificity for the diagnosis of neoplastic ascites. Serum concentration seems to be the main determinant of laminin levels in ascitic fluid and its values can be used as a diagnostic parameter in the study of neoplastic ascites.