Flexible modelling of the dissolution performance of directly compressed tablets.

In this study, a compartmental disintegration and dissolution model is proposed for the prediction and evaluation of the dissolution performance of directly compressed tablets. This dissolution model uses three compartments (Bound, Disintegrated, and Dissolved) to describe the state of each particle of active pharmaceutical ingredient. The disintegration of the tablet is captured by three fitting parameters. Two disintegration parameters, ß0 and ßt,0, describe the initial disintegration rate and the change in disintegration rate, respectively. A third parameter, α, describes the effect of the volume of dissolved drug on the disintegration process. As the tablet disintegrates, particles become available for dissolution. The dissolution rate is determined by the Nernst-Brunner equation, whilst taking into account the hydrodynamic effects within the vessel of a USP II (paddle) apparatus. This model uses the raw material properties of the active pharmaceutical ingredient (solubility, particle size distribution, true density), lending it towards early development activities during which time the amount of drug substance available may be limited. Additionally, the strong correlations between the fitting parameters and the tablet porosity indicate the potential to isolate the manufacturing effects and thus implement the model as part of a real-time release testing strategy for a continuous direct compression line.

Salivary Antioxidants Levels in Patients with Oral Lichen Planus.

Background: Oral lichen planus (OLP) is one of the most common diseases of the oral mucosa, which exact pathogenesis remains unknown. Free radicals and reactive oxygen species could play an important role in the pathogenesis of oral lichen planus. Aims and Objectives: This study aimed to compare the salivary levels of uric acid, superoxide dismutase, glutathione peroxidase, and albumin in the patients with oral lichen planus and healthy subjects. Materials and Methods: Thirty patients with oral lichen planus and 30 healthy subjects, who were matched for age and sex, were enrolled in this case-control study. The salivary concentration of uric acid, superoxide dismutase, glutathione peroxidase, and albumin were examined in these individuals using the spectrophotometry and coulometric technique. The data were analyzed through Mann-Whitney test and T test by SPSS software (ver. 19). Results: Salivary uric acid and albumin levels in patients with oral lichen planus and healthy controls were not statistically different (p > 0.05); however, the concentrations of salivary superoxide dismutase in OLP patients (660.4 ± 266.4 U/g protein) and healthy controls (935.73 ± 561.9 U/g protein) were significantly different (p < 0/05). Also, salivary glutathione peroxidase levels in healthy controls (1049.98 ± 964.56 mU/mL) were remarkably higher than OLP patients (244.12 ± 170.78 mU/mL) (p < 0/001). Conclusion: The salivary superoxide dismutase concentration, as an indicator of antioxidant system, in OLP patients was significantly higher than healthy subjects. The glutathione peroxidase levels in these patients were remarkably lower than healthy controls. It is suggestive that these markers could be effective in pathogenesis of OLP.

Encapsulated insular carcinoma of the thyroid arising in graves' disease: report of a case and review of the literature.

Insular carcinoma represents a rather rare form of thyroid cancer. Total encapsulation and history of hyperthyroidism are even extremely rarer events with only a few cases reported in the literature. This article reports an insular carcinoma of the thyroid in a 51-year-old woman, displaying these features and pulmonary metastasis with no cervical lymph node involvement.

Identification and Characterization of a High Vancomycin-Resistant Staphylococcus aureus Harboring VanA Gene Cluster Isolated from Diabetic Foot Ulcer.

OBJECTIVES: Staphylococcus aureus is a common cause of human infection, and emergence of vancomycin-resistance S. aureus is a great concern for treatment of methicillin-resistant S. aureus,(MRSA) in recent years (MRSA). Here, we report the isolation of high-level VRSA. MATERIALS AND METHODS: S. aureus was isolated from foot ulcer of a diabetic woman in Tehran, Iran. Antibiotic susceptibility was determined according to CLSI guidelines. VanA gene cluster PCR was carried out and PCR amplicon of vanA was sequenced. RESULTS: S. aureus had high-level vancomycin-resistant (MIC 512 ≥ µg/ml). Patient's history revealed that VRSA isolate was acquired through community transmission. Only vanA, vanR and vanS genes were amplified in our isolate. Sequencing revealed that the vanA sequence had high similarity to the vanA sequence of Tn1546. CONCLUSION: Although VRSA infection continues to be rare, isolation of community-acquired VRSA is a significant issue and it needs the efforts of public health authorities.

Obstructive jaundice in Iran: factors affecting early outcome.

BACKGROUND: Understanding any factors which influence the morbidity and mortality in patients with obstructive jaundice in each society will better guide appropriate management and lead to improved survival. This study aimed to assess baseline etiologies, clinical manifestations, diagnostic results, and morbidity and mortality related to obstructive jaundice in Iranian patients. METHODS: The hospital recorded files of 133 patients with the final diagnosis of obstructive jaundice who had been admitted to the Taleqhani Hospital in Tehran between January 2001 and September 2004 were reviewed. RESULTS: The most common etiologies of obstructive jaundices were neoplasia and then common bile duct stone in the two genders. The results of ultrasonography were positive in less than half of the patients. However, the most positive results were related to endoscopic retrograde cholangiopancreatography (ERCP). The in-hospital mortality rate in patients less than 50 years old and elderly patients was 0% and 6.76%, respectively. The in-hospital morbidity rate was 2.25% and 7.51%, respectively in both patients and it was commonly related to infection of ulcer (44.46%), pneumonia (14.75%), myocardial infarction (14.75%), and subdiaphragmatic abscess (11.29%). In patients with a diagnosis of benign obstruction, only one patient died of severe sepsis. In malignant group, preoperative characteristics, such as weight loss (P=0.015) and serum bilirubin concentration more than 16 mg/dl and postoperative complications, such as sepsis (P<0.001), cardiac arrest (P<0.001), and hepatic coma (P<0.001) were main predictors for the in-hospital mortality rate. CONCLUSION: Although the mortality and morbidity of obstructive jaundice in our study are less than those in other studies, the determination of preoperative clinical and laboratory indices and postoperative complications of patients is needed for the control of mortality and morbidity rate.

Allograft en bloc vagino-utero-ovarian avascular transplant versus autograft implantation in rats.

OBJECTIVES: The aim of this study was to compare the results of an allograft en bloc vagino-uteroovarian avascular transplant with those of autograft implantation in rats. MATERIALS AND METHODS: Thirty-four inbred adult virgin female Albino rats (age range, 10 - 12 weeks) were divided into 2 groups: the control group (autograft, n=11) and the study group (en bloc vagino-utero-ovariectomy, n=23). In the study group, the uterus and adnexa and the ovaries of the donor rat were transplanted to the recipient animal. Twenty-five to 30 days after that procedure, all rats were killed, and the samples were assessed histopathologically. No immunosuppressive drugs were used. RESULTS: Ten rats died during the postoperative period. In 16 rats, the transplanted system had survived completely at the conclusion of the study. In each of the study groups, complete survival of the uterus and ovaries was noted in 8 rats (34.8% in the study group and 72.8% in the control group). In all rats except 1, histopathologic examination did not reveal any signs of the classic criteria for tissue rejection reaction. The lack of revascularization, nonspecific signs of inflammation, and the presence of large granular lymphocytes and natural killer cells were reported. CONCLUSIONS: Our data indicated that the outcome of both allograft and homograft avascular en bloc transplant of vagino-utero-ovariectomy in rats was successful, and that immunologic rejection did not seem to have an important role in those procedures.

Treatment of infected pseudoaneurysm in drug abusers: ligation or reconstruction?

BACKGROUND: Recently, there has been an increase in the incidence of major vascular complications such as infected pseudoaneurysm due to intravenous drug use. OBJECTIVE: For better understanding of the existing controversies regarding the optimal surgical management of infected pseudoaneurysm, the present study was conducted. METHODS: Medical charts of 36 consecutive patients who underwent surgery in Taleghani Hospital, Tehran, Iran from 1996 through 2003, were retrospectively analyzed. RESULTS: We studied the hospital records of 33 cases; two patients had bilaterally infected pseudoaneurysms and one underwent an emergency reoperation. The total number of operations was 36. Eleven cases (30.5%) underwent ileofemoral reconstruction and 25 (69.5%) arteries were ligated. All patients presented with infected femoral or brachial pseudoaneurysms due to intravenous drug abuse. Postoperatively, there was no hemorrhage, vascular thrombosis, amputation, or mortality. Three cases (8%) had incisional infections (2 [18%] after reconstruction and 1 [4%] after ligation operation) and 7 patients (19%) had claudication (all after ligation). CONCLUSION: Ligation is the optimal management for infected pseudoaneurysm, because it is easy, cost-effective, and safe. Reconstruction is not recommended, because of an extended infection at the location of pseudoaneurysm and at the artificial graft site.