Spectrophotometric determination of lansoprazole in pharmaceuticals using bromate-bromide mixture based on redox and complexation reactions

Two sensitive spectrophotometric methods are described for the determination of lansoprazole (LPZ) in bulk drug and in capsule formulation. The methods are based on the oxidation of lansoprazole by insitu generated bromine followed by determination of unreacted bromine by two different reaction schemes. In one procedure (method A), the residual bromine is treated with excess of iron (II), and the resulting iron (III) is complexed with thiocyanate and measured at 470 nm. The second approach (method B) involves treating the unreacted bromine with a measured excess of iron (II) and remaining iron (II) is complexed with orthophenanthroline at a raised pH, and measured at 510 nm. In both methods, the amount of bromine reacted corresponds to the amount of LPZ. The experimental conditions were optimized. In method A, the absorbance is found to decrease linearly with the concentration of LPZ (r = -0.9986) where as in the method B a linear increase in absorbance occurs (r = 0.9986) The systems obey Beer's law for 0.5-4.0 and 0.5-6.0 µg mL-1 for method A and method B, respectively. The calculated molar absorptivity values are 3.97µ10(4) and 3.07µ10(4) L mol-1cm-1 for method A and method B, respectively, and the corresponding Sandell sensitivity values are 0.0039 and 0.0013 µg cm-2. The limit of detection (LOD) and quantification (LOQ) are also reported for both methods. Intra-day and inter-day precision, and accuracy of the methods were established as per the current ICH guidelines. The methods were successfully applied to the determination of LPZ in capsules and the results tallied well with the label claim and the results were statistically compared with those of a reference method by applying the Student's t-test and F-test. No interference was observed from the concomitant substances normally added to capsules. The accuracy and validity of the methods were further ascertained by performing recovery experiments via standard-addition method.

Adsorption of hidrogen peroxide on the surface of silica - titania mixed oxide obtained by the sol-gel processing method

This work describes the sol-gel mixed oxide SiO2/TiO2 property, ST, as prepared, and submitted to heat treatment a 773 K, STC. SEM and EDS images show, within magnification used, a uniform distribution of the TiO2 particles in SiO2/TiO2 matrix. Both, ST and STC adsorb hydrogen peroxide on the surface and through EPR and UV-Vis diffuse reflectance spectra, it was possible to conclude that the species on the surface is the peroxide molecule attached to the Lewis acid site of titanium particle surface, alphaTi(H2O2)+. As the material is very porous, presumably the hydrogen peroxide molecule is confined in the matrix pores on the surface, a reason why the adsorbed species presents an exceptional long lived stability.

Temperature effect in potassium and nitrate ions in soil transport

When doing researches on solute dynamics in porous medium, the knowledge of medium characteristics and percolating liquids, as well as of external factors is very important. An important external factor is temperature and, in this sense, our purpose was determining potassium and nitrate transport parameters for different values of temperature, in miscible displacement experiments. Evaluated parameters were retardation factor (R), diffusion/dispersion coefficient (D) and dispersivity, at ambient temperature (25 up to 28 ºC), 40 ºC and 50 ºC. Salts used were potassium nitrate and potassium chlorate, prepared in a solution made up of 5 ppm nitrate and 2.000 ppm potassium, with Red-Yellow Latosol porous medium. Temperature exhibited a positive influence upon porous medium solution and upon dispersion coefficient.

Effective diffusivity and convective mass transfer coefficient during the drying of bananas

In this article, a methodology is used for the simultaneous determination of the effective diffusivity and the convective mass transfer coefficient in porous solids, which can be considered as an infinite cylinder during drying. Two models are used for optimization and drying simulation: model 1 (constant volume and diffusivity, with equilibrium boundary condition), and model 2 (constant volume and diffusivity with convective boundary condition). Optimization algorithms based on the inverse method were coupled to the analytical solutions, and these solutions can be adjusted to experimental data of the drying kinetics. An application of optimization methodology was made to describe the drying kinetics of whole bananas, using experimental data available in the literature. The statistical indicators enable to affirm that the solution of diffusion equation with convective boundary condition generates results superior than those with the equilibrium boundary condition.

Pseudocisto pancreático com envolvimento esplênico: relato de caso

The authors present a case report of a pancreatic pseudocyst with an unusual spleen involvement. The aspects of this rare complication are discussed, as well as the probable etiologic factors. The outcome was satisfactory and the surgical treatment consisted of the resection of its thick capsule, since the local anatomic conditions would not permit a splenectomy with distal pancreatectomy, considered to be the ideal surgery.

Localization of metastasis within the sentinel lymph node biopsies: a predictor of additional axillary spread of breast cancer?

PURPOSE: To explore the relationship between morphological characteristics and histologic localization of metastasis within sentinel lymph nodes (SLN) and axillary spread in women with breast cancer. METHODS: We selected 119 patients with positive SLN submitted to complete axillary lymph node dissection from July 2002 to March 2007. We retrieved the age of patients and the primary tumor size. In the primary tumor, we evaluated histologic and nuclear grade, and peritumoral vascular invasion (PVI). In SLNs we evaluated the size of metastasis, their localization in the lymph node, number of foci, number of involved lymph nodes, and extranodal extension. RESULTS: Fifty-one (42.8%) patients had confirmed additional metastasis in non-sentinel lymph nodes (NLSN). High histologic grade, PVI, intraparenchymatous metastasis, extranodal neoplastic extension and size of metastasis were associated with positive NLSN. SLN metastasis affecting the capsule were associated to low risk incidence of additional metastasis. After multivariate analysis, PVI and metastasis size in the SLN remained as the most important risk factors for additional metastasis. CONCLUSIONS:The risk of additional involvement of NSLN is higher in patients with PVI and it increases progressively according the histologic localization in the lymph node, from capsule, where the afferent lymphatic channel arrives, to the opposite side of capsule promoting the extranodal extension. Size of metastasis greater than 6.0 mm presents higher risk of additional lymph node metastasis.

Pathogenicity of Rhodococcus equi in mice, isolated from environment, human and horse clinical samples

Rhodococcus equi is a facultative intracellular pathogen associated with bronchopneumonia, mesenteric lymphadenitis and enterocolitis in foals. Although R. equi is likely to be found in every horse-breeding farm, the clinical disease is unrecognized in most of them. Capsule components, equi factor, micolic acid and some products encoded by the large 85-90Kb plasmid were described as virulence factors. However, the pathogenesis of R. equi infections and the sensibility of foals are not completely understood. The aim of this study was evaluate the virulence of R. equi isolated from human, horses and environment for mices. Nine strains carrying the 85-90Kb plasmid isolated from foal clinical specimens, one from immunodeficient human patient and six plasmidless strains (four isolated from feces, one from pasture and one from immunodeficient human patient) were inoculated in cyclophosphamide immunossuppressed mice. The pathological changes and viability of R. equi cells in the liver of mice was verified after the 3rd, 6th an 10th day after inoculation for horse and environmental isolates and for R. equi isolates from human patients on the 1st, 3rd and 6th day. During the necropsy procedures, infiltrate of macrophages and pyogranulomatous lesions were detected after the sixth pos-inoculation day in the liver and spleen. In horse isolates, only plasmid positive strains were virulent, but in human isolates both strains (plasmid positive e plasmid negative) were virulent. Both groups of the immunossupressed mice inoculated with R. equi isolated from environment showed pathological changes. All R. equi strains were unable to kill non imunossuppressed mice.

Acetabular deepening in the treatment of severe canine hip dysplasia

A technique to restore acetabular anatomy by deepening the acetabular cavity and reconstructing the femoral head ligament and the joint capsule was tested on nine large breed dogs with severe hip dysplasia and acute subdislocation or dislocation. The technique consisted of two phases. First, all dogs were submitted to bilateral pectinotomy. In a second surgical intervention on the same dogs the acetabulum was approached and deepened, and the femoral head ligament and the joint capsule were reconstructed. In general, within 30 days of the surgery dogs could stand on the operated member to walk. Except for two dogs, all the others recovered pelvic member locomotive ability within 60-90 days after surgery. It is concluded that acetabuloplasty is a good alternative for treatment of severe canine hip dysplasia.

Focal symmetrical encephalomalacia in sheep

Focal symmetrical encephalomalacia (FSE) is the most prominent lesion seen in the chronic form of enterotoxemia by Clostridium perfringens type D. This paper reports FSE in sheep in Brazil. Six deaths occurred within a seven days period in a flock of 70, four to 30-month-old Santa Inês sheep in the state of Paraíba in the Brazilian semiarid. The flock was grazing a paddock of irrigated sprouting Cynodon dactylon (Tifton grass), and supplemented, ad libitum, with a concentrate of soybean, corn and wheat. Nervous signs included blindness and recumbence. A 19 month-old sheep was examined clinically and necropsied after a clinical course of three days. Gross lesions were herniation of the cerebellar vermis and multifocal, bilateral, symmetric brownish areas in the internal capsule, thalamus and cerebellar peduncles. Histologic lesions were multifocal, bilateral malacia with some neutrophils, swelling of blood vessels endothelium, perivascular edema, and hemorrhages. The flock was vaccinated, before the outbreak, with only one dose of Clostridium perfringens type D vaccine. Two factors are suggested to be important for the occurrence of the disease: insufficient immunity due to the incorrect vaccination; and high nutritional levels by the supplementation with highly fermentable carbohydrates.

Serology, polymerase chain reaction and histopathology for leptospirosis in samples collected at slaughter from dairy cows of Parnaiba region, state of Piauí, Brazil

The presence of anti leptospiral agglutinins (microscopic agglutination test - MAT) and DNA of leptospires was investigated in the kidney and urine (Polymerase Chain Reaction - PCR) in samples collected at the time of slaughter of cattle originating from the dairy basin of Parnaíba, Piauí, Brazil, as also the lesions in kidney, lung, liver, uterus, ovary and placenta (histopathology and immunohistochemistry). In the MAT, Hardjo was the predominant serovar with the highest number of reagent animals for the strain Hardjobovis/Sponselee. Anti-leptospiral antigens were scored in epithelial cells, interstitial vascular endothelium, endothelium of glomerular capillaries and Bowman's capsule of 20 positive animals. Inflammatory cells were more common in the kidney. PCR was positive in urine and kidney tissue

Serogroups and virulence genes of Escherichia coli isolated from psittacine birds

Escherichia coli isolates from 24 sick psittacine birds were serogrouped and investigated for the presence of genes encoding the following virulence factors: attaching and effacing (eae), enteropathogenic E. coli EAF plasmid (EAF), pili associated with pyelonephritis (pap), S fimbriae (sfa), afimbrial adhesin (afa), capsule K1 (neu), curli (crl, csgA), temperature-sensitive hemagglutinin (tsh), enteroaggregative heat-stable enterotoxin-1 (astA), heat-stable enterotoxin -1 heat labile (LT) and heat stable (STa and STb) enterotoxins, Shiga-like toxins (stx1 and stx2), cytotoxic necrotizing factor 1 (cnf1), haemolysin (hly), aerobactin production (iuc) and serum resistance (iss). The results showed that the isolates belonged to 12 serogroups: O7; O15; O21; O23; O54; O64; O76; O84; O88; O128; O152 and O166. The virulence genes found were: crl in all isolates, pap in 10 isolates, iss in seven isolates, csgA in five isolates, iuc and tsh in three isolates and eae in two isolates. The combination of virulence genes revealed 11 different genotypic patterns. All strains were negative for genes encoding for EAF, EAEC, K1, sfa, afa, hly, cnf, LT, STa, STb, stx1 and stx2. Our findings showed that some E. coli isolated from psittacine birds present the same virulence factors as avian pathogenic E. coli (APEC), uropathogenic E. coli (UPEC) and Enteropathogenic E. coli (EPEC) pathotypes.

Clinical and pathological aspects of chronic Senecio spp. poisoning in sheep

This paper describes an outbreak of chronic Senecio spp. poisoning in grazing sheep in Rio Grande do Sul, Brazil, causing the death of 10 out of 860 adult sheep. Eight sick ewes were euthanized and necropsied. Cattle from this farm were also affected. Clinical signs included progressive weight loss, apathy and photosensitization. Four out of seven tested sheep had increased gamma-glutamyl transferase serum activity and two of them presented serum elevation of alkaline phosphatase. At necropsy, three out of eight ewes presented slightly irregular toughened livers with multifocal nodules, two out of eight ewes had a whitish liver with thickened fibrotic Glisson's capsule partially adhered to the diaphragm, and three out of eight ewes had smooth and grossly normal livers. Necropsy findings attributed to liver failure included hydropericardium (7/8), ascites (5/8), icterus (2/8), hydrothorax (1/8), and edema of mesentery (1/8). The main hepatic histological findings that allowed the establishment of the diagnosis were megalocytosis, proliferation of bile ducts and fibrosis. Spongy degeneration was observed in the brains of all eight necropsied sheep and was more severe at the cerebellar peduncles, mesencephalon, thalamus, and pons. These are suggested as the portions of election to investigate microscopic lesions of hepatic encephalopathy in sheep with chronic seneciosis. The diagnosis of Senecio spp. poisoning was based on epidemiology, clinical signs, laboratory data, necropsy and histological findings.

Ultrastructure of the intercellular protuberances in leaves of Paepalanthus superbus Ruhl. (Eriocaulaceae)

Mature leaves of Paepalanthus superbus exhibit intercellular protuberances between the inner periclinal walls of the epidermal and the parenchyma cells surface, as well as on the surface of the parenchyma mesophyll cells. These structures are mostly prominent around the parenchyma cells, forming a gel capsule-like structure. Histochemical tests with ruthenium red indicate the pectic nature of the intercellular deposits, with scattered lipidic inclusions as revealed by sudan IV and sudan black B. Ultrastructural analyses show a fibrillar matrix with scattered fimbriate and tubular structures, and a distinct margin delimited by a dense membrane-like structure. Our results suggest that the protuberances are derived from secretory activity, and are formed after the development of the intercellular spaces. For P. superbus this structure may represent an important cell wall specialisation, related with the adhesion and transport mechanisms between cells.

Morphology and anatomy of the fruit and seed in development of Chorisia speciosa A. St.-Hil. - Bombacaceae

The structure of the fruit and seed in development of Chorisia speciosa are described with the main purpose of clarifying the origin and nature of the hairs that cover the seeds and aiding future taxonomical and ecological studies of the group. The fruit is an ellipsoid loculicide capsule and presents the exocarp formed by 7-10 cells layers, with very thick walls and evident simple pits. A great number of mucilage secretory cavities and ramified vascular bundles, accompanied by fibers, occur in the parenchymatic mesocarp. The endocarp derives from the ventral epidermis of the ovary wall, whose cells undergo a gradual elongation, become lignified, and constitute the trichomes which cover the mature seeds. The fruit aperture occurs by means of a suture evident in the ovarian wall in the middle region of the carpel leaf. Anatropous and bitegmic ovules, provided by a hypostase, give rise to campilotropous and bitegmic seeds. The testa is uniseriate, the exotegmen is completely formed by macrosclereids, and mucilage secretory cavities occur in the mesotegmen. The endotegmen, which is differentiated in the endothelium, is crushed in the mature seed. The plicate embryo, which occupies practically the entire seminal cavity, is found between endosperm layers, both being rich in lipids.

Lung tissue mechanics in the early stages of induced paracoccidioidomycosis in rats

Pulmonary dysfunction represents the most important cause of death in patients with paracoccidioidomycosis (PBM). In order to investigate the functional changes of the lungs in the early stages of PBM, a model of benign disease was developed by intratracheal challenge of 12-week old isogenic Wistar rats with 1 x 106 yeast forms of Paracoccidioides brasiliensis. Animals were studied 30 and 60 days after infection, when fully developed granulomas were demonstrable in the lungs. Measurements of airway resistance, lung elastance and tissue hysteresis were made during sinusoidal deformations (100 breaths/min, tidal volume = 2 ml) with direct measurement of alveolar pressure using the alveolar capsule technique. Infection caused a significant increase in hysteresis (infected: 1.69, N = 13; control: 1.13, N = 12, P = 0.024, ANOVA), with no alterations in airway resistance or lung elastance. Histopathological analysis revealed the presence of fully developed granulomas located in the axial compartment of the lung interstitial space. These results suggest that alterations of tissue mechanics represent an early event in experimental PBM