Potential degradation products (DPs), even in small concentrations, can cause changes in pharmacological and toxicological properties of a drug with a significant impact on product quality and safety. Thus, their stability and understanding of possible degradation mechanisms have a significant importance. Although liquid chromatography is the conventional technique used for forced degradation studies with excellent accuracy and reproducibility, the main disadvantages of the technique are being expensive and time-consuming.
View Article and Find Full Text PDFThe presented study describes the development of reversed-phase liquid chromatography method using a core-shell particle column with a pentafluorophenyl stationary phase for the dissociation constant (pKa) determination of the tetracycline group antibiotics (tetracycline, oxytetracycline, chlortetracycline) and their epimers (4-epitetracycline, 4-epioxytetracycline, 4-epichlortetracycline). The pH values were measured in the acetonitrile (ACN)-water binary mixtures, used as mobile phases, instead of in water and take into account the effect of the activity coefficients. Thermodynamic acid dissociation constant (pKa1) values of studied antibiotics and their epimers were calculated using retention factor (k) at different mobile phase pH values in studied binary mixtures with ACN percentages of 20, 25, 30 and 35% (v/v).
View Article and Find Full Text PDFAm J Dermatopathol
October 2017
Terra firma-forme dermatosis (TFFD) is a clinical condition characterized by brown-gray, velvety, pigmented patches or plaques, resembling dirt on the skin. Nevoid acanthosis nigricans (NAN) is a rare and recently described form of acanthosis nigricans occurring during childhood or early adulthood. Herein we describe a patient with TFFD, initially misdiagnosed as NAN.
View Article and Find Full Text PDFNodular cystic fat necrosis (NCFN) is characterized by mobile subcutaneous nodules composed of necrotic adipocytes encapsulated by fibrous tissue. The classical presentation of NCFN is solitary or multiple, up to 40, discrete nodules scattered usually on the extremities or trunk. Here, the authors present an elderly woman who developed an unusual and striking clinical picture of NCFN, two months after a fall.
View Article and Find Full Text PDFSirolimus is a mammalian target of the rapamycin, a protein kinase, which is responsible for inhibition of T cell and B cell proliferation. Sirolimus has side effects on lugs, and may cause cryptogenic organizing pneumonia, diffuse alveolar hemorrhage, lymphocytic pneumonitis, hypersensitivity pneumonitis, desquamative interstitial pneumonia, and pulmonary alveolar proteinosis. Diagnosis is based on the combination of clinical, radiological, histological, and pathological investigation.
View Article and Find Full Text PDFAlthough diverticular disease of the colon is common, the occurrence of rectal diverticula is extremely rare with only sporadic reports in the literature since 1911. Symptomatic rectal diverticula are seen even less frequently, and surgical intervention is needed for only complicated cases. Here we report the case of a 63-year-old woman presenting with rectal diverticulitis mimicking rectal carcinoma with intestinal obstruction.
View Article and Find Full Text PDFBackground: Familial Mediterranean Fever (FMF), also inherited with autosomal recessive trait, is characterized by recurrent episodes of fever, arthritis, and serositis. Congenital Byler Syndrome (Progressive Familial Intrahepatic Cholestasis) inherited with autosomal recessive trait and characterized by defective secretion of bile acids. FMF associated Amyloid A deposition occurs in many tissues and organs, but amyloid goiter is a rare entity that leads to enlargement and dysfunction of the thyroid.
View Article and Find Full Text PDFObjective: Many epidemiological studies have shown that human papillomavirus related infections play a major role in cervical preinvasive and invasive lesions. ASCUS (atypical cells of undetermined significance) observed in about 4-5% of all cervical cytology specimens. We searched for the presence of HPV with immunohistochemical methods in the biopsy material of patients diagnosed with ASCUS using cytology.
View Article and Find Full Text PDFIn this work, thermodynamic acidity constants (pssKa) of methicillin, oxacillin, nafcillin, cloxacilin, dicloxacillin were determined with reverse phase liquid chromatographic method (RPLC) by taking into account the effect of the activity coefficients in hydro-organic water-acetonitrile binary mixtures. From these values, thermodynamic aqueous acidity constants of these drugs were calculated by different approaches. The linear relationships established between retention factors of the species and the polarity parameter of the mobile phase (ET(N)) was proved to predict accurately retention in LC as a function of the acetonitrile content (38%, 40% and 42%, v/v).
View Article and Find Full Text PDFIntrauterine devices (IUD) are frequently used as a family planning procedure in developing countries because they are easy to administer and governmental policies support their use in many countries. It is recommended that IUDs be removed or replaced after 10 years, but longer use is common, especially in developing countries. In some cases, rare infections such as pelvic inflammatory diseases, pelvic tuberculosis, or abdominopelvic actinomycosis related to IUD can develop.
View Article and Find Full Text PDFAim: The purpose of this study was to determine the possible protective effects of captopril treatment against apoptosis in the brain induced by burn injury.
Material And Methods: Under ether anaesthesia, Wistar albino rats (200-250 g) were exposed to a 900C (burn) or 250C (sham) water bath for 10 s. The ACE group was treated with i.
This study aimed to compare the efficacy of topical dimethyl sulfoxide (DMSO), intralesional and systemic carnitine as monotherapy and in combination against ulceration in rats induced by intradermal doxorubicin extravasation. Sixty-nine 3-month-old male Wistar albino rats, weighing between 200-225 g, were used in this study. Rats were applied monotherapy or a combination of topical DMSO, intraperitoneal or intralesional carnitine.
View Article and Find Full Text PDFVertebral column is a common site for bony metastases in patients with systemic malignancy. Patients with metastatic spinal tumors usually present with pain. Some tumors are asymptomatic and can be detected during screening examinations.
View Article and Find Full Text PDFPurpose: This study was carried out to determine the ocular pharmacokinetics, efficacy and potential endothelial toxicity of moxifloxacin (MF) after a single intracameral bolus injection of 500 µg/0.1 ml in a rabbit model.
Materials And Methods: Forty-eight eyes of 24 New Zealand White Rabbits were separated into six groups, each including four rabbits.
Objective: To investigate the role of endogenous neuronal nitric oxide synthase (nNOS) on brain injury after burn and the effects of the captopril.
Methods: Wistar albino rats (200-250 g) were exposed on the dorsal surface to 90°C (burn) or 25°C (sham) water for 10 s. The ACE group was treated with intraperitoneal 10 mg/kg captopril immediately after burn and this treatment was repeated twice daily.
In this work, dissociation constants values of seven beta lactam antibiotics in water and acetonitrile-water mixtures using spectrophotometric and reversed phase liquid chromatography methods were determined. The dissociation constant values of these compounds were calculated by NLREG and STAR programs. Aqueous pK(a) values of beta lactam antibiotics were calculated with extrapolation by means of the Yasuda-Shedlovsky and mole fraction equations.
View Article and Find Full Text PDFRenal cell carcinoma (RCC) metastases to the pancreas are reported to be rare. Isolated multiple pancreatic metastases are even rarer. We report a 68-year-old asymptomatic male patient who presented with multiple metastatic nodular lesions in the pancreas demonstrated by computerized tomography 3.
View Article and Find Full Text PDFIntroduction. Reports of epithelial ovarian carcinomas metastatic to the pancreas are very rare. We herein present a metastasis of high grade papillary serous ovarian cancer to mid portion of pancreas.
View Article and Find Full Text PDFAn optimization methodology is introduced for investigating the retention behavior and the separation factor of metformin, gliclazide (I.S.) and glibenclamide.
View Article and Find Full Text PDFObjective: Parathyroid adenomas are the most common cause of primary hyperparathyroidism. Biological studies have shown that parathyroid adenomas are monoclonal proliferations. Up to date, five cell types have been identified in normal parathyroid tissues; chief cells, vacuolated chief cells, dark chief cells, oxyphil cells and transitional oxyphil cells.
View Article and Find Full Text PDFIndian J Pathol Microbiol
August 2011
Background: Columnar cell lesions (CCLs) with or without atypia frequently coexist with invasive or in situ breast carcinomas. In this study, 39 mastectomy specimens containing CCLs coexisting with invasive carcinomas were retrospectively analyzed for cellular characteristics and structural pattern of CCL neighboring the tumor.
Materials And Methods: The expression of estrogen receptor (ER), progesterone receptor (PR), and p53 antibodies in CCL and coexisting invasive tumors, type of invasive tumor, histopathologic grade, and presence of atypia in CCL have been studied.
In the present study, the combined effect of mobile phase polarity and pH on retention behavior of some ARA-IIs (irbesartan, losartan, valsartan and telmisartan) is investigated. The linear relationships established between retention factors of the species and the polarity parameter of the mobile phase has proved to predict accurately retention in LC as a function of the acetonitrile content (50%, 55%, 60%, v/v). The suggested model uses the pH value in the acetonitrile-water mixture as mobile phase instead of pH value in water and takes into account the effect of activity coefficients.
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