Histopathological Findings in the Viscera of Malformed Neotropical Viperids.

Congenital malformations (CMs) or developmental abnormalities are pathological processes defined as morphological defects that originate during embryonic stages. A wide variety of CMs is observed in reptiles, most of which are incompatible with normal life. Characterization of CMs and their pathogenesis are of great importance for the conservation of reptiles, including neotropical viperids (NVs). External CMs are often reported in these species, but little is known about concomitant microscopical findings in the viscera of malformed individuals. In order to partially fill in this gap in knowledge, we aimed to investigate and characterize histopathological findings in the viscera of malformed NVs, jararacas (Bothrops jararaca) and South American rattlesnakes (Crotalus durissus), correlating these findings with features of external CMs. From 78 malformed snakes analysed, 100% (19/19) of rattlesnakes and 98.3% (58/59) of jararacas had histopathological changes in the viscera. Liver and/or kidney fatty degeneration was the most common finding in malformed and control animals. Renal glomerulocystic and tubular disease was significantly correlated with brachygnathia (P < 0.05) in jararacas. These results add to the body of knowledge of snake pathology and demonstrate some associations between external CMs and visceral histopathological findings, some of which could have implications for individual survival.

Histopathological findings in the viscera of malformed neotropical viperids

Congenital malformations (CMs) or developmental abnormalities are pathological processes defined as morphological defects that originate during embryonic stages. A wide variety of CMs is observed in reptiles, most of which are incompatible with normal life. Characterization of CMs and their pathogenesis are of great importance for the conservation of reptiles, including neotropical viperids (NVs). External CMs are often reported in these species, but little is known about concomitant microscopical findings in the viscera of malformed individuals. In order to partially fill in this gap in knowledge, we aimed to investigate and characterize histopathological findings in the viscera of malformed NVs, jararacas (Bothrops jararaca) and South American rattlesnakes (Crotalus durissus), correlating these findings with features of external CMs. From 78 malformed snakes analysed, 100% (19/19) of rattlesnakes and 98.3% (58/59) of jararacas had histopathological changes in the viscera. Liver and/or kidney fatty degeneration was the most common finding in malformed and control animals. Renal glomerulocystic and tubular disease was significantly correlated with brachygnathia (P < 0.05) in jararacas. These results add to the body of knowledge of snake pathology and demonstrate some associations between external CMs and visceral histopathological findings, some of which could have implications for individual survival.

Histopathological findings in the viscera of malformed neotropical viperids

Congenital malformations (CMs) or developmental abnormalities are pathological processes defined as morphological defects that originate during embryonic stages. A wide variety of CMs is observed in reptiles, most of which are incompatible with normal life. Characterization of CMs and their pathogenesis are of great importance for the conservation of reptiles, including neotropical viperids (NVs). External CMs are often reported in these species, but little is known about concomitant microscopical findings in the viscera of malformed individuals. In order to partially fill in this gap in knowledge, we aimed to investigate and characterize histopathological findings in the viscera of malformed NVs, jararacas (Bothrops jararaca) and South American rattlesnakes (Crotalus durissus), correlating these findings with features of external CMs. From 78 malformed snakes analysed, 100% (19/19) of rattlesnakes and 98.3% (58/59) of jararacas had histopathological changes in the viscera. Liver and/or kidney fatty degeneration was the most common finding in malformed and control animals. Renal glomerulocystic and tubular disease was significantly correlated with brachygnathia (P < 0.05) in jararacas. These results add to the body of knowledge of snake pathology and demonstrate some associations between external CMs and visceral histopathological findings, some of which could have implications for individual survival.

Benign Peripheral Nerve Sheath Tumor in a Wild Toco Toucan ( Ramphastos toco )

Peripheral nerve sheath tumors are a heterogeneous group of neoplasms that comprise neurofibromas, schwannomas, neurilemmomas, and perineuromas. In animals, peripheral nerve sheath neoplasms are most commonly diagnosed in dogs and cattle, followed by horses, goats, and cats, but their occurrence is uncommon in birds. An adult, free-living, male toco (common) toucan (Ramphastos toco) was admitted to the zoo animal clinic with weight loss, dehydration, and presence of a soft nodule adhered to the medial portion of the left pectoral muscle. Clinical, cytologic, and computed tomography scan results were indicative of a neoplasm. The toucan died during surgical resection of the mass. Necropsy, histopathologic, and immunohistochemical findings confirmed the diagnosis of benign peripheral nerve sheath tumor. To our knowledge, benign peripheral nerve sheath tumor has not previously been reported in a toucan or any other species in the order Piciformes.

Antimicrobial and biofilm inhibiting diketopiperazines.

Diketopiperazines are the smallest cyclic peptides known. 90% of Gram-negative bacteria produce diketopiperazines and they have also been isolated from Gram-positive bacteria, fungi and higher organisms. Biosynthesis of cyclodipeptides can be achieved by dedicated nonribosomal peptide synthetases or by a novel type of synthetases named cyclopeptide synthases. Since the first report in 1924 a large number of bioactive diketopiperazines was discovered spanning activities as antitumor, antiviral, antifungal, antibacterial, antiprion, antihyperglycemic or glycosidase inhibitor agents. As infections are of increasing concern for human health and resistances against existing antibiotics are growing this review focuses on the antimicrobial activities of diketopiperazines. The antibiotic bicyclomycin is a diketopiperazine and structure activity studies revealed the unique nature of this compound which was finally developed for clinical applications. The antimicrobial activities of a number of other diketopiperazines along with structure activity relationships are discussed. Here a special focus is on the activity-toxicity problem of many compounds setting tight limitations to their application as drugs. Not only these classical antimicrobial activities but also proposed action in modulating bacterial communication as a new target to control biofilms will be evaluated. Pathogens organized in biofilms are difficult to eradicate because of the increase of their tolerance for antibiotics for several orders. Diketopiperazines were reported to modulate LuxR-mediated quorum-sensing systems of bacteria, and they are considered to influence cell-cell signaling offering alternative ways of biofilm control by interfering with microbial communication. Concluding the review we will finally discuss the potential of diketopiperazines in the clinic to erase biofilm infections.

Total pancreatectomy: porcine model for inducing diabetes - anatomical assessment and surgical aspects.

BACKGROUND: The swine is an essential model for carrying out preclinical research and for teaching complex surgical procedures. There is a lack of experimental models describing anatomical and surgical aspects of total pancreatectomy in the pig. MATERIALS AND METHODS: The experiments were performed on 10 white male swine weighing 27-33 kg. The animals were premedicated with midazolam (0.4 mg/kg, i.m.) and ketamine (4 mg/kg, i.m.). Anesthesia was induced with propofol (1-2 mg/kg, i.v.) and was maintained with propofol and fentanyl (0.3 mg and 0.1 µg/kg/min, respectively, i.v.). The surgical period ranged from 44 to 77 min. The pancreas anatomy, and the main arterial, venous and pancreatic duct anatomy were assessed. RESULTS: The pancreas anatomy was composed of 3 lobes, the 'splenic', 'duodenal' and 'connecting' lobe which is attached to the anterior portion of the portal vein. The splenic artery and the junction of the splenic vein and portal vein were divided. The left gastric artery was dissected and separated from its origin at the splenic artery. The head of the pancreas is disposed in a C shape. The pancreas was dissected and liberated from the right portion of the portal vein and the infrahepatic vena cava. The pancreas was separated from the duodenum preserving the pancreaticoduodenal artery, then we performed the total pancreatectomy preserving the duodenum, common bile duct and spleen. CONCLUSION: Total pancreatectomy with duodenum, bile duct and spleen preservation in the pig is feasible and an important instrument for research purposes and teaching surgical technique.

Nucleocytoplasmic shuttling of heterodimeric splicing factor U2AF.

The U2 small nuclear ribonucleoprotein auxiliary factor (U2AF) is a heterodimeric splicing factor composed of 65-kDa (U2AF(65)) and 35-kDa (U2AF(35)) subunits. The large subunit of U2AF recognizes the intronic polypyrimidine tract, a sequence located adjacent to the 3' splice site that serves as an important signal for both constitutive and regulated pre-mRNA splicing. The small subunit U2AF(35) interacts with the 3' splice site dinucleotide AG and is essential for regulated splicing. Like several other proteins involved in constitutive and regulated splicing, both U2AF(65) and U2AF(35) contain an arginine/serine-rich (RS) domain. In the present study we determined the role of RS domains in the subcellular localization of U2AF. Both U2AF(65) and U2AF(35) are shown to shuttle continuously between the nucleus and the cytoplasm by a mechanism that involves carrier receptors and is independent from binding to mRNA. The RS domain on either U2AF(65) or U2AF(35) acts as a nuclear localization signal and is sufficient to target a heterologous protein to the nuclear speckles. Furthermore, the results suggest that the presence of an RS domain in either U2AF subunit is sufficient to trigger the nucleocytoplasmic import of the heterodimeric complex. Shuttling of U2AF between nucleus and cytoplasm possibly represents a means to control the availability of this factor to initiate spliceosome assembly and therefore contribute to regulate splicing.

Electrophysiological effects of Ageratum conyzoides L. on the guinea-pig heart.

An extract obtained from the leaves of Ageratum conyzoides L. changed the electrocardiogram, atrial impulse velocity, and coronary vessels resistance on isolated guinea-pig heart. Electrocardiographic alterations were: (a) PR interval increased from 80 +/- 1.4 ms to 105 +/- 14 ms (p < 0.01); (b) QT interval decreased from 170 +/- 2 ms to 154 +/- 7 ms (p < 0.01); (c) heart rate decreased from 170 +/- 17 bpm to 152 +/- 21 bpm (p < 0.01);(d) atrial impulse velocity decreased from 51 +/- 2 cm/s to 45 +/- 3 cm/s (p < 0.01);(e) the time spent for the impulse to be conducted from the atrium to the His bundle increased from 73 +/- 13 ms to 100 +/- 24 ms (p < 0.01). These effects disappeared after a washout.

ACGT and vicilin core sequences in a promoter domain required for seed-specific expression of a 2S storage protein gene are recognized by the opaque-2 regulatory protein.

The expression of Brazil nut storage albumin genes is highly regulated during seed development. Several sequences in the promoter of one of these genes show homologies with the target sites of the maize O2 bZIP regulatory protein. We therefore asked whether the O2 protein would recognize these promoter sequences. We show that the O2 protein binds to three different sequences (F1, F2 and F3). F1 and F3 are hybrid C/G and A/G boxes, respectively, that are homologous to the O2-binding site of a maize alpha-zein gene. F2 is a new O2-binding sequence related to the O2 target sites of the Coix alpha-coxin, the maize b-32 genes and the AP-1 pseudopalindrome. Molecular modelling showed that an Asn and a Ser in the 02 DNA binding domain make different base-specific contacts with each operator. 5' Promoter deletions of the be2S1 gene showed that the domain containing the O2 target sites F1 and F2 is required for detectable reporter gene expression in transgenic tobacco seeds. Moreover, the homologous coix O2 protein was shown to in situ transactivate the promoter region encompassing the three O2-binding sites F1, F2 and F3. Thus, these sites may be in vivo regulatory sequences mediating activation by bZIP regulatory proteins.

Colostral mononuclear phagocytes are able to kill enteropathogenic Escherichia coli opsonized with colostral IgA.

Enteropathogenic Escherichia coli (EPEC) is the main aetiological agent of acute diarrhoea among low socioeconomic level infants in developing countries. Breast-feeding provides infant protection against acute gastrointestinal and respiratory infections; however, little is known about the protective role of colostral phagocytes in the gut of newborn infants. In the present investigation we studied the ability of human colostral MN phagocytes to kill EPEC as well as the interactions between these cells and colostral and serum opsonins. The authors observed that the microbicidal activity of colostrum MN phagocytes was dependent on previous EPEC opsonization with colostral supernatant or blood serum. A defatted colostrum supernatant pool presented opsonic activity for EPEC killing at levels equivalent to those of normal serum. IgA-depleted colostrum supernatant showed significantly lower opsonic activity, whereas purified IgA from the same colostrum pool was a potent opsonin which induced EPEC killing at levels equivalent to those of untreated colostrum. Colostral MN phagocytes are able to release superoxide anion when incubated with both EPEC opsonized with untreated colostrum and purified IgA. Purified IgA was also able to restore opsonic activity of IgA-depleted colostrum. A colostrum pool without C3 and IgG induced EPEC killing by colostral MN phagocytes at rates equivalent to those of untreated colostrum supernatant. Addition of an IgM MoAb (My43) anti-human Fc alpha receptor resulted in a significant inhibition of EPEC killing when bacteria were opsonized with purified IgA, suggesting an interaction between IgA and Fc alpha R. With respect to serum opsonins, we observed that IgG plus complement component C3 were necessary to induce EPEC killing by the colostrum MN phagocytes. Colostral phagocyte killing of enteropathogenic bacteria may represent an additional mechanism of breast-feeding protein against intestinal infections during the first week of life.

An open trial of ceftazidime in the treatment of complicated urinary tract infections.

In an open prospective trial, twenty-two patients (twenty-one males and one female) with complicated urinary tract infections were treated with 2 g of ceftazidime every 12 hours (nineteen patients were treated intramuscularly and three intravenously for 7 or 10 days). The weight, age and underlying disorders of the urinary tract are indicated for each patient, as well as infecting pathogens and corresponding MICs. Clinical cure, as defined by complete resolution of symptoms and signs was obtained in all the patients. The over all bacteriological clearance rate was 93.3%. Four out of five Pseudomonas aeruginosa infections were cleared. There were no adverse events during ceftazidime treatment except for slight pain around the site of intramuscular injection. No changes in laboratory parameters attributable to ceftazidime therapy were noted. Ceftazidime is a safe and effective drug in the treatment of complicated urinary tract infections.

[Orbito-rhino-cerebral phycomycosis (mucormycosis): report of a case]. / Ficomicose (mucormicose) órbito-rino-cerebral: registro de um caso.

The case of a 15 year old white man, diabetic in cetoacidosis, with a orbit-rhino-cerebral phycomycosis is reported. The illness had an acute onset and the treatment was iniciated early with Amphotericin-B and unilateral osteotomy of maxillary and ethmoidal sinus. With this treatment the patient did well with residuals of ophtalmoplegia and amaurosis on the right. Interesting investigation aspects are the occluded internal carotid on the same side of the affected orbit and the CAT-SCAN finding of moderated ventricular dilatation (two months after hospital admission). Mycology, pathophysiology, histopathology, clinical aspects, diagnosis and therapy are discussed, comparing the findings of this case with avaliable literature. An increased number of survivors can be expected with earlier recognition and more aggressive therapy. Treatment of the underlying debilitating disease, Amphotericin-B and surgical debridement of necrotic tissue, are frequently necessary such as observed in the case reported. The favorable results obtained with the proposed managment are stressed.

Two components of the cardiac action potential. I. Voltage-time course and the effect of acetylcholine on atrial and nodal cells of the rabbit heart.

Transmembrane potentials recorded from the rabbit heart in vitro were displayed as voltage against time (V, t display), and dV/dt against voltage (V, V or phase-plane display). Acetylcholine was applied to the recording site by means of a hydraulic system. Results showed that (a) differences in time course of action potential upstroke can be explained in terms of the relative magnitude of fast and slow phases of depolarization; (b) acetylcholine is capable of depressing the slow phase of depolarization as well as the plateau of the action potential; and (c) action potentials from nodal (SA and AV) cells seem to lack the initial fast phase. These results were construed to support a two-component hypothesis for cardiac electrogenesis. The hypothesis states that cardiac action potentials are composed of two distinct and physiologically separable "components" which result from discrete mechanisms. An initial fast component is a sodium spike similar to that of squid nerve. The slow component, which accounts for both a slow depolarization during phase 0 and the plateau, probably is dependent on the properties of a slow inward current having a positive equilibrium potential, coupled to a decrease in the resting potassium conductance. According to the hypothesis, SA and AV nodal action potentials are due entirely or almost entirely to the slow component and can therefore be expected to exhibit unique electrophysiological and pharmacological properties.