Newly developed method for the determination of sitagliptin phosphate using rubeanic acid as a precipitating agent via the use of ISNAG continues flow fluorimeter

A new, a simple, sensitive and fast developed method for the estimation of sitagliptin phosphate in pure and pharmaceutical drugs (tablet). This method based on the reaction between sitagliptin phosphate and rubeanic acid to form reddish-black ppt, using ISNAG-Fluorimeter analyzer via the measure of diverged light at 90° from radiation source which is used a range of high intensity ultraviolet 184.9 nm & 253.7 nm by low-pressure mercury lamp while detector cell can detect at 410-1150 nm. The resultant of diverged light by an interaction between incident photons and precipitated particles giving rise to a longer wavelength that the detector can detected. Chemical and physical parameters were studied and optimized. The calibration graph was linear in the range of (0.03-13 ) mmol.L−1 , with correlation coefficient ( r )= 0.9881 ,linearity percentage r2%= 97.64 , L.O.D = 0.7848µg/sample and RSD lower than 0.6 % for (3&7 ) mmol.L−1 ( eight replicates) concentration of sitagliptin phosphate. This method was successfully applied for the determination of sitagliptin phosphate in two different companies of pharmaceutical drugs. A comparison was made between the newly developed method analysis with the classical method (UV-spectrophotometer by measuring of absorbance ) using standard addition method via the use of t-test, it was noticed that there was no significant difference between two methods at %95 confidence level.

Hemolytic Crisis in a Dog with Copper-Associated Chronic Hepatitis

Background: Copper is an essential micronutrient for the body to function properly. However, although it is a vital element, an excess of copper in the body is extremely toxic. Copper toxicity has been reported mainly in sheep. In dogs, clinicopathological signs of toxicity are characterized by chronic liver failure. This means that the hemolytic crisis so common in sheep is a condition rarely associated with toxicity in dogs, so there are very few descriptions of this condition in the veterinary literature. The purpose of this report is to describe a case of hemolytic crisis in a dog with copper-associated chronic hepatitis.Case: A medium-sized 6-year-old bitch was brought to the Veterinary Hospital of the Federal University of Santa Maria, with clinical presentation of apathy, anorexia and red urine. A physical examination revealed mildly jaundiced mucosa and dark brown urine. A urinalysis indicated the presence of protein, bilirubin and occult blood. The blood count revealed hypochromic macrocytic anemia, leukocytosis due to left shift neutrophilia and thrombocytopenia. Serum biochemistry showed elevated levels of alanine aminotransferase and alkaline phosphatase. The animal was given a blood transfusion due to the severity of her anemia, but her clinical condition worsened and she died, whereupon her body was sent for necropsy. This necropsy revealed conspicuous signs of jaundice, splenomegaly and altered liver and kidney color. The liver was brownish, with its natural surface firm and slightly irregular. The kidneys were diffusely blackened. The urine was dark brown. Fragments of different organs were collected, fixed in 10% buffered formalin solution, routinely processed for histopathology and stained with hematoxylin and eosin. A histological dissection of the liver showed the hepatic lobes dissected by fibrosis, forming islands of hepatocytes and numerous lymphocytes and plasmocytes. Brown granular pigment was observed in periportal hepatocytes. Perls Prussian blue and rubeanic acid staining techniques were performed to characterize this pigment. Most of the pigment reacted strongly to rubeanic acid and but not to Perls’ Prussian blue, thus characterizing it as copper. Random hepatic necrosis was visible. The kidneys contained hemoglobin and necrotic epithelial cells obstructing the renal tubules. Based on the clinical and anatomopathological aspects, a diagnosis of hemolytic crisis due to copper-associated chronic hepatitis was established.Discussion: The most accepted mechanism to explain the occurrence of hemolysis is that copper long stored in hepatocytes is massively released into the bloodstream due to some stressful condition. When too much copper circulates in the bloodstream it inhibits enzymes that act on the energy metabolism of red blood cells, thereby lowering the synthesis of energy and nucleotides needed for glutathione activity, and causing hemoglobin to transform into methemoglobin. In the case reported here, copper toxicosis presumably originated from the animal’s diet since, according to the literature, the periportal distribution of copper revealed during histology suggests that the event resulted from excessive copper intake or was secondary to previous cholestatic liver injury. This paper describes a case of hemolytic crisis in a dog with copper-associated chronic hepatitis and, emphasizes the importance of including copper toxicity as a differential diagnosis for dogs presenting hemolytic crisis, in order to assist veterinarians in managing their patients.

Effects of Light Activated In-office Bleaching on Permeability, Microhardness, and Mineral Content of Enamel

SUMMARY The aim of this study was to evaluate the permeability (PE), microhardness (KHN), and mineral change in enamel after LED/laser activated in-office bleaching. For PE, the coronal portion of premolars (n=51) was subjected to bleaching with 35% hydrogen peroxide (Whiteness HP Maxx, FGM Dental Products, Joinville, SC, Brazil). The samples were stained via the histochemical method, which involves a copper sulphate solution and rubeanic acid. The penetration of dye into the enamel was measured. The KHN of enamel was assessed before treatment, immediately after the bleaching treatment, and again after one week. The calcium and phosphorus content were analyzed with a scanning electron microscope with energy-dispersive X-ray (JSM 6360LV, Jeol Ltd, Tokyo, Japan). The data set from each test was subjected to appropriate parametric statistical analysis (α=0.05). No significant differences were observed for PE in NLA and LA compared to the control group (p=0.98), as well as for calcium (p=0.16) and phosphorus (p=0.80) content. Significant reduction of KHN after bleaching occurred for both groups (p<0.001). After immersion in artificial saliva, the KHN of the enamel for all groups was similar to that seen before bleaching. Light activation during in-office bleaching does not produce significant changes in the enamel compared to a non–light-activated technique.

Dentin permeability of the apical third in different groups of teeth

This ex vivo study evaluated dentin permeability of the root canal in the apical third of different human groups of teeth. Eighty teeth were used, 8 from each dental group: maxillary and mandibular central incisors, lateral incisors and canines, maxillary first premolars (buccal and palatal roots), mandibular first premolars, and maxillary and mandibular second premolars, totalizing 88 roots that were distributed in 11 groups. The root canals were instrumented, irrigated with 1% NaOCl and 15% EDTA. Roots were immersed in 10% copper sulfate for 30 min and then in 1% rubeanic acid alcohol solution for the same period; this chemical reaction reveals dentin permeability by the formation of copper rubeanate, which is a dark-colored compound. Semi-serial 100-µm-thick cross-sections were obtained from the apical third of the roots. Five sections of each apical third were washed, dehydrated, cleared and mounted on glass slides for examination under optical microscopy. The percentage of copper ion infiltration and the amount of tubular dentin were quantified by morphometric analysis. The penetration of copper ions in the apical third ranged from 4.60 to 16.66%. The mandibular central and lateral incisors presented the highest dentin permeability (16.66%), while the maxillary canines and mandibular second and first premolars presented the lowest dentin permeability (4.60%, 4.80% and 5.71%, respectively; p<0.001). The other teeth presented intermediate permeability. In conclusion, dye penetration into dentin tubules at the apical region is strongly dependent on the group of teeth evaluated.