Comparison of Classical and Green RPLC Methods in the Determination of pKa Values of Some Piperazine Group Antihistamines.

In this study, protonation constant values and liquid chromatographic behaviors of hydrophobic cyclizine, chlorcyclizine, hydroxyzine, cinnarizine, cetirizine, meclizine, and buclizine in some water-organic solvent binary mixtures were examined for the first time using classical and green reverse phase liquid chromatography methods. In the isocratic study, the relationship of the retention time and mobile phase pH in water-organic solvent binary mixtures containing acetonitrile (45, 50, 55, 60, 65%, v/v), methanol (60, 65, 70, 75%, v/v) and ethanol (45, 50, 55, 56, 59, 60, 62, 65%, v/v) were determined at 37 °C. In the study, XBridge C18 and Gemini NX C18 columns suitable for the chemical properties of basic compounds were used. The obtained liquid chromatographic data were analyzed using the linear solvation energy relationship methodology and the SOLVER program. The aqueous protonation constant values of the investigated compounds were calculated using the linear relationship between the protonation constant data calculated in studied binary mixtures and some macroscopic constant values of the solvents used. The greenness of methods developed using three different solvents was evaluated with the Analytical Greenness Metric Approach, the Green Analytical Procedures Index, and the Green Solvent Selection Tool approaches.

Development of liquid chromatographic and UV-visible spectrophotometric methods for determination of pKa values of folic acid antimetabolites.

In this study, the values of ionization/protonation constants (pKa) of pemetrexed and raltitrexed, which are folic acid antimetabolites, were determined by reversed-phase liquid chromatography (RPLC) and UV-visible spectrophotometric methods at 25 °C. The pKass values were evaluated by retention time (tR) in binary acetonitrile-water mixtures with acetonitrile (ACN) contents of 13%, 15%, 17% and 20% (v/v) for the RPLC method and 13%, 15% and 17% (v/v) for the spectrophotometric method. The aqueous pKa values (pKaww) of the studied compounds were calculated from the pKass value using the macroscopic parameters (mole fraction and dielectric constant), which play an important role in solvent properties. In addition, the degree of ionization of pemetrexed and raltitrexed was calculated using the pKaww values.

Monitoring forced degradation of drugs using silica coated AgNPs with surface-enhanced Raman scattering.

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. As a powerful technique, surface-enhanced Raman scattering (SERS) can be an alternative with its high sensitivity, easy sample preparation and low cost. In this study, the degradation of both tofacitinib (TOF), a Janus kinase inhibitor, and methotrexate (MTX), an inhibitor of tetrahydrofolate dehydrogenase, are studied using SERS under hydrolytic, oxidative and thermal conditions using mesoporous silica coated silver nanoparticles (Si@AgNPs) as SERS substrates. The study demonstrated that the degradation of the tested drugs using Si@AgNPs as SERS substrates could be monitored through the spectral changes on SERS spectra of drugs under several degradation conditions.

Chromatographic Determination of Thermodynamic Acid Dissociation Constants of Tetracycline Antibiotics and Their Epimers.

The 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). Experimental data were analyzed by using an Origin 7.0 program to fit experimental data to the nonlinear expression derived. From calculated pKa1 values, the aqueous pKa values of studied compounds were calculated by different approaches and these values were compared.

Effect of temperature on the retention of Janus kinase 3 inhibitor in different mobile phase compositions using reversed-phase liquid chromatography.

In this study, the thermodynamic dissociation constant (pKa) values of tofacitinib in acetonitrile-water binary mixtures with of 25%, 30%, 35% and 45% (v/v) have been determined at 25-45 °C range of temperatures with reversed-phase liquid chromatography (RPLC). The chromatographic determination was achieved on a Kinetex Core-Shell EVO C18-Phenomenex (150 mm x 4.6 mm, 5 µm) analytical column. For each case pKa values and retention factors of tofacitinib by taking into account the effect of the activity coefficients in hydro-organic water-acetonitrile binary mixtures have been evaluated and which obtain by SOLVER algorithm of spreadsheet program Excel to fit experimental data to the nonlinear expression derived. From these values, the thermodynamic aqueous pKa value of the drug was calculated by different approaches. Thermodynamic parameters standard Gibbs free energy (ΔG°), standard enthalpy (ΔH°) and standard entropy (ΔS°) derived from dissociation constant measurements at six different temperatures were calculated by from linearity plots of IogKa against 1/T (van't Hoff plot).

Terra Firma-Forme Dermatosis Misdiagnosed as Nevoid Acanthosis Nigricans.

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. The patient had developed hyperkeratotic and hyperpigmented plaques on and around the umbilicus during pregnancy. Though regular in bathing practices, she could not clear away the lesions and concerned marks for inesthetic appearance. Histopathological findings were compatible with NAN, and she was prescribed 10% urea lotion. On a dramatic healing after 3 weeks, a diagnosis of TFFD is considered and confirmed by the lesions getting wiped away by vigorous rubbing with alcohol pads. We discuss the key points of differentiating TFFD from NAN, and underline the importance of alcohol test for accurate diagnosis.

Sirolimus-Induced Diffuse Alveolar Hemorrhage: A Case Report.

Sirolimus 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. We report a case of diffuse alveolar hemorrhage in a 33-year-old, female renal transplant recipient. After discontinuation of sirolimus, radiological images and clinical condition of the patient got better. We also planned steroid therapy for 6 months by tapering the dosage slowly. After steroid therapy, full recovery of pulmonary functions achieved, and the patient is observed in our outpatient clinic with lack of any pulmonary symptoms.

An Extraordinary Manifestation of Nodular Cystic Fat Necrosis.

Nodular 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. The patient had a large indurated plaque and subcutaneous nodule with superposing necrotic ulcers. During debridement of the ulcers, nearly 100 small nodules popped up freely along with a brownish discharge. Deep in the ulcer, the authors discovered a dislocated nail that belongs to an old hip prosthesis. Histopathological findings of the nodules were compatible with NCFN.

Rectal diverticulitis mimicking rectal carcinoma with intestinal obstruction: case report.

Although 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.

Amyloid goiter due to familial mediterranean Fever in a patient with byler syndrome: a case report.

BACKGROUND: 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. CASE REPORT: We present a rare case of 24 year old male patient who had liver and kidney transplantation due to Byler Syndrome and secondary amyloidosis related to FMF, diagnosed as rapidly growing large amyloid goiter. Deposits of extracellular amyloid and dense adipose metaplasia diagnostic for amyloid goiter are determined upon histopathological examination of thyroidectomy material. CONCLUSION: When goiter was detected in cases with history of systemic amyloidosis and rapidly growing goitre, amyloid goiter should be remembered at first. This case is unique since two autosomal genetic disorders are together in the same patient and important as it emphasizes the consequences of consanguineous marriage, early diagnosis and treatment compliance of FMF and the awareness of amyloid goiter in patients followed by primary care physicians and healthcare professionals.

Detection of HPV positivity by immunohistochemistry in colposcopic cervical biopsies with a cytological diagnosis of ASCUS.

OBJECTIVE: 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. MATERIAL AND METHOD: The colposcopic biopsy or Loop Electro Excisional Procedure (LEEP) material of 115 patients with a diagnosis of ASCUS were evaluated. HPV (type 6,11,16,18,31,33,42,51,52,56 and 58) immunohistochemistry was applied to all materials. The relationship between the biopsy results and HPV positivity was investigated. RESULTS: Cervical intraepithelial neoplasia (CIN) I was found in 34.8%, CIN II in 13% and CIN III in 9.6% of the patients and cervicitis was present in 42.6% of the patients. HPV immunohistochemistry was positive in 11 cases (9.6%) and no staining was seen in 104 cases (90.4%). No positive staining was seen in the chronic cervicitis cases. The rate of positive staining was 15% (6/34) in the CIN I diagnosed group, 20% (3/12) in the CIN II diagnosed group and 18.2% (2/9) in the CIN III diagnosed group. CONCLUSION: HPV positivity was found to be lower compared to the literature both in total and in cases diagnosed by biopsy. No staining occurred in any patient with cervicitis. In conclusion, we believe that immunohistochemical examination is not an appropriate method for the determination of HPV.

Estimation of thermodynamic acidity constants of some penicillinase-resistant penicillins.

In 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).

Determination of chromatographic dissociation constants of some carbapenem group antibiotics and quantification of these compounds in human urine.

The dissociation constant values (s (s) pKa ) of some carbapenem group drugs (ertapenem, meropenem, doripenem) in different percentages of methanol-water binary mixtures (18, 20 and 22%, v/v) were determined from the mobile phase pH dependence of their retention factor. Evaluation of these data was performed using the NLREG program. From calculated pKa values, the aqueous pKa values of these subtances were calculated by different approaches. Moreover, the correlation established between retention factor and the pH of the water-methanol mobile phase was used to determine the optimum separation conditions. In order to validate the optimized conditions, these drugs were studied in human urine. The chromatographic separation was realized using a Gemini NX C18 column (250 × 4.6 mm i.d., 5 µm particles) and UV detector set at 220 and 295 nm.

Thrombocytosis and small bowel perforation: unusual presentation of abdominopelvic actinomycosis.

Intrauterine 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. Pelvic actinomycosis is a rare disease and is often diagnosed incidentally during surgery. In recent years, there has been an increase in actinomycotic infections mostly due to long-term usage of IUD and forgotten intravaginal pessaries. It usually develops as an ascending infection. It is usually associated with non-specific symptoms such as lower abdominal pain, menstrual disturbances, fever, and vaginal discharge. The disease is sometimes asymptomatic. The rate of accurate preoperative diagnosis for pelvic actinomycosis is less than 10%, and symptoms and imaging studies sometimes mimic pelvic malignancy. This report details a case with abdominopelvic actinomycosis associated with an IUD presenting with highly elevated thromboctye count and small bowel perforation with abscess formation.

The effect of captopril on brain apoptosis after burn injury in rats.

AIM: 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.p. 10 mg/kg captopril immediately after burn injury and this treatment was repeated twice daily. At the end of the 24 hours, brain samples were taken. Apoptotic brain cells marked by terminal deoxynucleotidyl transferase-mediated d-UTPnick end labeling (TUNEL) were evaluated in the cerebellum and midbrain of rats. RESULTS: Apoptotic cells in the cerebellum were significantly decreased after captopril treatment and found to be lower when compared to the burn group (p < 0.001). In the midbrain of rats, the numbers of TUNEL-positive cells and apoptotic bodies were significantly increased in the burn group when compared to the control group (p < 0.001). The burn-induced changes were reduced in the captopril-treated burn group (p < 0.01). CONCLUSION: Captopril has beneficial effects in burn injury and should be assessed as a therapeutic agent in the management of this condition.

Lack of relationships between FGF19 staining pattern, lymph node metastasis and locally invasive characteristics of the tumor in colorectal cancers.

INTRODUCTION: Colorectal cancers are in the top of the cancer-related causes of death in the world and lymph node metastasis is accepted as the primary prognostic factor. In this study, correlations of FGF19 staining pattern with local invasion and lymph node metastasis in a series of colorectal cancers were investigated. METHODS: This studyincluded 81 colorectal cancer patients who underwent surgery in our hospital with no evidence of preoperative radiological distant metastasis. Routine pathological examination of the resection material was performed in order to identify vascular, perineural and serosal infiltration, regional lymph node metastasis and the degree of differentiation. Tumor tissue samples were stained with an immunohistochemistry method for FGF 19 evaluation and the staining pattern was statistically compared with the above mentioned characteristics of the tumors. RESULTS: The patient population consisted of 47 females and 34 males with a median age of 70 years. In 40 patients regional lymph nodes were positive and 51%, 32% and 38% had serosal, perineural and vascular invasion. While 64 cases were moderately-differentiated, 11 cases were well-differentiated and 6 poorly- differentiated, there was no association with FGF 19 staining, including intensity. CONCLUSION: No evidence of significant statistically correlation was found between FGF 19 staining pattern and serosal, perineural, vascular invasion, lymph node involvement and degree of differentiation.

Carnitine or dimethyl sulfoxide, or both, for the treatment of anthracycline extravasation in rats.

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. Control groups received saline or no drug. The necrotic area was measured and extravasated neutrophil leukocytes were counted in healthy tissue adjacent to necrotic areas. Monotherapy with topical and systemic carnitine did not significantly reduce the size of necrotic areas. However, topical DMSO had reduced necrotic areas and inflammatory cells significantly and the addition of systemic carnitine to topical DMSO had increased the efficacy. DMSO is an effective, safe, and easy-to-apply treatment for doxorubicin-induced extravasation. Further clinical studies are needed to evaluate the use of carnitine in combination with DMSO.

Ocular pharmacokinetics, safety and efficacy of intracameral moxifloxacin 0.5% solution in a rabbit model.

PURPOSE: 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. 0.1 ml of 0.5% intracameral moxifloxacin (500 µg) injection was injected to the right eyes and 0.1 ml of balanced salt solution to the left eyes (control). Aqueous humor (AH) and vitreous samples were collected at the 0.5th, 1st, 3rd, 6th, 12th and 24th hours from both eyes of group 1, 2, 3, 4, 5 and 6, respectively. MF concentrations were determined by high performance liquid chromatography. These were compared with the minimum inhibitory concentrations (MIC) and mutant prevention concentrations (MPC) for frequent endophthalmitis pathogens. Electron and light microscopical evaluation of the corneas were performed. RESULTS: Moxifloxacin reaches higher concentration than the MIC of all common endophthalmitis pathogens in the AH and exceeds the mutant prevention concentration levels for Streptococcus pneumonia, Streptococcus viridans, flouroquinolone susceptible Coagulase-negative staphylococcus and flouroquinolone susceptible Staphylococcus aureus for 6 h. The half-life of moxifloxacin in the AH was 2.2 h. Electron and light microscopic evaluation revealed no noticeable sign of toxicity. CONCLUSIONS: Peroperative intracameral moxifloxacin injection for endophthalmitis prophylaxis is a safe and effective method in uncomplicated phacoemulsification surgery.

Solitary spinous process metastasis: a case report.

Vertebral 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. Magnetic resonance imaging (MRI) of the vertebral column with the panel of available imagining methods and the clinical findings should be used for the diagnosis of spinal metastasis. A 45-year-old man was admitted with low back pain. With a history of rectum surgery and radiotherapy, he was on chemotherapy for rectum adenocarcinoma. F18 sodium fluoride positron emission tomography scan which was performed three weeks ago showed no abnormalities other than the primary surgical site. Magnetic resonance imaging of the lumbar vertebrae spine revealed a lesion on the tip of L4 spinous process. Excisional biopsy of L4 spinous process was performed. Histologic examination revealed mucinous adenocarcinoma. He had no low back pain at two-months follow-up. We could not find any solitary spinous process metastasis reported in English literature. Patients with nonspecific spinal pain with a previous cancer history should be carefully evaluated for a spinal metastasis. Even a solitary spinous process lesion may turn out to be the initial manifestation of a spinal metastasis.

nNOS expression in the brain of rats after burn and the effect of the ACE inhibitor captopril.

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. At the end of the 24 h brain samples were taken. nNOS was studied in brain areas by immunohistochemistry. RESULTS: There was no difference between the cerebellar and hypothalamic areas the nNOS expression of all groups. nNOS expression increased in the frontal cortex, striatum and midbrain in the burn group compared to the control group. In the frontal cortex, nNOS expression significantly decreased after ACE inhibitor treatment (p<0.05). The striatal nNOS of the ACE group significantly increased when compared to the control group (p=0.001). In the midbrain of the animals, nNOS decreased in the ACE group. Hippocampal nNOS expression did not change after burn and significantly increased after ACE inhibitor therapy (p<0.05). CONCLUSIONS: Our data showed that the pathophysiological events following burn appear to be related to an acute inflammatory reaction which is associated with nNOS in the frontal cortex, striatum and midbrain, and captopril treatment abrogates the nNOS response in the frontal cortex and midbrain.