Impact analysis of primary and secondary research in radiology journals

INTRODUCTION

Primary and secondary studies are considered the two major research categories. In this study, we examined the scientific and social media impact of primary and secondary publication types in papers published radiological journals during 2010-2020.

MATERIALS AND METHODS

PubMed publication type tags were used to filter original articles and systematic review and meta-analysis (SR/MA) articles. Clarivate Web of Science was utilized to obtain a list of all radiology journals from the category "Radiology, Nuclear Medicine and Imaging" in Science Citation Index Expanded (SCIE). Automated approach was developed for programmatic extraction of bibliometric and Altmetric yearly citations of each included article using Dimensions API and Altmetric API with Python. Statistical analysis was performed to compare the citation rates between primary and secondary research articles.

RESULTS

A total of 96,684 published articles from 2010 to 2020 were identified and their meta-data collected. The mean 2-year citation count following publication year was 5.8 for primary research and 10.2 for SR/MA articles (p < 0.001). Between 2010 and 2020, the mean number of citations per SR/MA article was 51.3 compared to 30.5 per primary research article (p < 0.001). Mean Altmetric score was 8.2 in SR/MA compared to 3.7 for primary research articles (p < 0.001).

CONCLUSION

Secondary research studies have been increasing in impact in both academia and social media compared to primary research. Our results highlight the importance and impact of systematic reviews and meta-analysis articles as a scientifically influential study type in radiology.

The Effect of the COVID-19 Pandemic on Academic Research Gender Disparities in Radiology

RATIONALE AND OBJECTIVES

Gender disparities have long existed in radiology. The COVID-19 pandemic disrupted research activities worldwide and have impacted gender disparities across medical specialties. This study investigates the effect of the COVID-19 pandemic on gender disparities in radiology academic authorship.

MATERIALS AND METHODS

A retrospective observational study was conducted using data from 110 843 global and 23 977 US radiology articles. The gender of authors was determined using an automated gender inference tool. Descriptive statistics were applied to explore authorship changes overall globally, in the US as well as across countries and states.

RESULTS

Female first-authorship increased globally from 16.9% to 17.6% (p < 0.001), and in the US, from 19.0% to 19.6% (p = 0.19) in the peri-COVID period. The combined female percentage increased from 19.7% to 20.0% globally (p = 0.021), and from 20.2% to 21.1% in the US (p = 0.006). Country-level analysis revealed significant increases in female authorship in Colombia, Denmark, Egypt, France, India, and Japan, while New Zealand demonstrated a decrease in female authorship. In the US, Florida, Indiana, Louisiana, Massachusetts, and Ohio experienced increases in female authorship, whereas South Carolina demonstrated a decrease in female authorship.

CONCLUSION

In contrast with other medical fields, the study demonstrates that radiology experienced a slight increase in female authorship in radiology research globally and in the US during the COVID period. While the pandemic may have influenced these findings, further research is needed to establish regional causal relationships and identify best practices for promoting gender equity in radiology research.

Effects of pharmacogenetics on pharmacokinetics and toxicity of doxorubicin in Egyptian breast cancer patients

This study investigates the impact of single nucleotide polymorphisms in genes (SLC22A16 and CBR1) involved in the pharmacokinetics and toxicity of doxorubicin (DOX) in Egyptian female patients with breast cancer.Patients administered DOX (60 mg/m2) for 4 cycles every 3 weeks. The peak DOX plasma concentration was measured using a validated chromatographic method. The genotyping for the selected SNPs, SLC22A16 T > C (rs714368), and CBR1 C > T (rs20572), was performed by RT-PCR. Patients were monitored for hematological and cardiac toxicities.The variant carriers of CBR1 C > T (rs20572) exhibited significantly higher DOX concentration, but no significant association to DOX-induced hematological toxicity. On the other hand, SLC22A16 T > C (rs714368) had no significant influence on DOX plasma concentration, but was significantly correlated with lower risk of neutropenia (OR 0.31, 95% CI 0.12-0.75, p = 0.01) and leukopoenia (OR 0.18, 95% CI 0.07-0.5, p = 0.001). DOX-related cardiotoxicity was correlated with the cumulative dose of DOX (R = 0.238, p = 0.017), but not with any of the two examined SNPs.Genetic polymorphisms in SLC22A16 and CBR1 may explain the inter-individual variations in DOX pharmacokinetics and toxicity. Using pharmacogenetic testing is important to customise drug therapy for cancer patients treated with anthracyclines.

Metabolic syndrome: imaging features and clinical outcomes

Metabolic syndrome, which affects around a quarter of adults worldwide, is a group of metabolic abnormalities characterized mainly by insulin resistance and central adiposity. It is strongly correlated with cardiovascular and all-cause mortality. Early identification of the changes induced by metabolic syndrome in target organs and timely intervention (eg, weight reduction) can decrease morbidity and mortality. Imaging can monitor the main components of metabolic syndrome and identify early the development and progression of its sequelae in various organs. In this review, we discuss the imaging features across different modalities that can be used to evaluate changes due to metabolic syndrome, including fatty deposition in different organs, arterial stiffening, liver fibrosis, and cardiac dysfunction. Radiologists can play a vital role in recognizing and following these target organ injuries, which in turn can motivate lifestyle modification and therapeutic intervention.

Longitudinal Monitoring of Quantitative Imaging Kinetics of Primary Tumor and Nodal Volumes Using the MR-Linac Device in Head and Neck Cancer Patients

PURPOSE/OBJECTIVE(S)

We aim to characterize the serial quantitative apparent diffusion coefficient (ADC) changes of the target disease volume using diffusion-weighted imaging (DWI) acquired weekly during radiation therapy (RT) on a 1.5T MR-Linac and correlate these changes with tumor response and oncologic outcomes for head and neck squamous cell carcinoma (HNSCC) patients.

MATERIALS/METHODS

Thirty patients with pathologically confirmed HNSCC and received curative-intent RT at the University of Texas MD Anderson Cancer Center, were included in this prospective study. Baseline and weekly MRIs (weeks 1-6) were obtained, and various ADC parameters (mean, 5th, 10th, 20th, 30th, 40th, 50th, 60th, 70th, 80th, 90th and 95th percentile) were extracted from the target regions of interest (ROIs). Pre-RT and weekly ADC parameters were correlated with response during RT, loco-regional control, and the development of relapse using the Mann-Whitney U test. The Wilcoxon signed-rank test was used to compare the weekly ADC versus baseline values. Weekly volumetric changes (Δvolume) for each ROI were correlated with ΔADC using Spearman's Rho test. Recursive partitioning analysis (RPA) was performed to identify the optimal ΔADC threshold associated with different oncologic outcomes.

RESULTS

There was an overall significant rise in all ADC parameters during different time points of RT compared to baseline values for both GTV-P & GTV-N. The increased ADC values for GTV-P were statistically significant only for primary tumors achieving CR during RT. RPA identified GTV-P ΔADC 5th percentile >13% at the 3rd week of RT as the most significant parameter associated with CR for GTV-P during RT (p <0.001). Baseline ADC parameters didn't significantly correlate with response to RT or other oncologic outcomes. There was a significant decrease in residual volume of both GTV-P & GTV-N throughout the course of RT. Additionally, a significant negative correlation between mean ΔADC and Δvolume for GTV-P at the 3rd and 4th week of RT was detected (r = -0.39, p = 0.044 & r = -0.45, p = 0.019, respectively).

CONCLUSION

Assessment of ADC kinetics at regular intervals throughout RT is potentially able to predict the response to RT and oncologic outcome. Further studies with larger cohorts and multi-institutional data are needed for validation of our results.

Long-term outcomes of flow diversion for unruptured intracranial aneurysms: a systematic review and meta-analysis

BACKGROUND

Flow diverters have been widely used in clinical practice for more than a decade. However, most outcome data are limited to 1 year timepoints. This study aims to offer meta-analysis data on long-term (>1 year) safety and effectiveness results for patients with aneurysms treated with flow diverters.

METHODS

PubMed, Web of Science, Embase, and SCOPUS were searched up to February 24, 2022 using the AutoLit platform. We included primary studies assessing the long-term outcomes for flow diverter devices to manage unruptured internal carotid artery aneurysms with a follow-up period of >1 year. The meta-analysis was carried out using Comprehensive Meta-Analysis software (CMA).

RESULTS

Eleven studies were included in the meta-analysis. The pooled occlusion rates after flow diversion treatment for unruptured intracranial brain aneurysms were 77%, 87.4%, 84.5%, 89.4%, 96% for 1 year, 1-2 years, 2 years, 3 years, and 5 years follow-up, respectively. The in-stent stenosis rate was 4.8% and the retreatment rate for the long-term follow-up period was 5%. No delayed rupture of the aneurysm was reported, and there was one case of delayed ischemic stroke. The sensitivity analysis of the prospective studies showed a complete occlusion rate of 83.5% and 85.2% for 1 and 3 years of follow-up, respectively.

CONCLUSION

Flow diverters are safe and effective in short- and long-term follow-up and rarely cause serious delayed side effects.

Deep-learning CT reconstruction in clinical scans of the abdomen: a systematic review and meta-analysis

OBJECTIVE

To perform a systematic literature review and meta-analysis of the two most common commercially available deep-learning algorithms for CT.

METHODS

We used PubMed, Scopus, Embase, and Web of Science to conduct systematic searches for studies assessing the most common commercially available deep-learning CT reconstruction algorithms: True Fidelity (TF) and Advanced intelligent Clear-IQ Engine (AiCE) in the abdomen of human participants since only these two algorithms currently have adequate published data for robust systematic analysis.

RESULTS

Forty-four articles fulfilled inclusion criteria. 32 studies evaluated TF and 12 studies assessed AiCE. DLR algorithms produced images with significantly less noise (22-57.3% less than IR) but preserved a desirable noise texture with increased contrast-to-noise ratios and improved lesion detectability on conventional CT. These improvements with DLR were similarly noted in dual-energy CT which was only assessed for a single vendor. Reported radiation reduction potential was 35.1-78.5%. Nine studies assessed observer performance with the two dedicated liver lesion studies being performed on the same vendor reconstruction (TF). These two studies indicate preserved low contrast liver lesion detection (> 5 mm) at CTDIvol 6.8 mGy (BMI 23.5 kg/m2) to 12.2 mGy (BMI 29 kg/m2). If smaller lesion detection and improved lesion characterization is needed, a CTDIvol of 13.6-34.9 mGy is needed in a normal weight to obese population. Mild signal loss and blurring have been reported at high DLR reconstruction strengths.

CONCLUSION

Deep learning reconstructions significantly improve image quality in CT of the abdomen. Assessment of other dose levels and clinical indications is needed. Careful choice of radiation dose levels is necessary, particularly for small liver lesion assessment.

Perirenal lymphatics: anatomy, pathophysiology, and imaging spectrum of diseases

Despite being rarely discussed, perinephric lymphatics are involved in many pathological and benign processes. The lymphatic system in the kidneys has a harmonious dynamic with ureteral and venous outflow, which can result in pathology when this dynamic is disturbed. Although limited by the small size of lymphatics, multiple established and emerging imaging techniques are available to visualize perinephric lymphatics. Manifestations of perirenal pathology may be in the form of dilation of perirenal lymphatics, as with peripelvic cysts and lymphangiectasia. Lymphatic collections may also occur, either congenital or as a sequela of renal surgery or transplantation. The perirenal lymphatics are also intimately involved in lymphoproliferative disorders, such as lymphoma as well as the malignant spread of disease. Although these pathologic entities often have overlapping imaging features, some have distinguishing characteristics that can suggest the diagnosis when paired with the clinical history.

Adrenal Neoplasms: Lessons from Adrenal Multidisciplinary Tumor Boards

The radiologic diagnosis of adrenal disease can be challenging in settings of atypical presentations, mimics of benign and malignant adrenal masses, and rare adrenal anomalies. Misdiagnosis may lead to suboptimal management and adverse outcomes. Adrenal adenoma is the most common benign adrenal tumor that arises from the cortex, whereas adrenocortical carcinoma (ACC) is a rare malignant tumor of the cortex. Adrenal cyst and myelolipoma are other benign adrenal lesions and are characterized by their fluid and fat content, respectively. Pheochromocytoma is a rare neuroendocrine tumor of the adrenal medulla. Metastases to the adrenal glands are the most common malignant adrenal tumors. While many of these masses have classic imaging appearances, considerable overlap exists between benign and malignant lesions and can pose a diagnostic challenge. Atypical adrenal adenomas include those that are lipid poor; contain macroscopic fat, hemorrhage, and/or iron; are heterogeneous and/or large; and demonstrate growth. Heterogeneous adrenal adenomas may mimic ACC, metastasis, or pheochromocytoma, particularly when they are 4 cm or larger, whereas smaller versions of ACC, metastasis, and pheochromocytoma and those with washout greater than 60% may mimic adenoma. Because of its nonenhanced CT attenuation of less than or equal to 10 HU, a lipid-rich adrenal adenoma may be mimicked by a benign adrenal cyst, or it may be mimicked by a tumor with central cystic and/or necrotic change such as ACC, pheochromocytoma, or metastasis. Rare adrenal tumors such as hemangioma, ganglioneuroma, and oncocytoma also may mimic adrenal adenoma, ACC, metastasis, and pheochromocytoma. The authors describe cases of adrenal neoplasms that they have encountered in clinical practice and presented to adrenal multidisciplinary tumor boards. Key lessons to aid in diagnosis and further guide appropriate management are provided. © RSNA, 2023 Online supplemental material is available for this article. Quiz questions for this article are available through the Online Learning Center.

Operator assessment versus core laboratory adjudication of recanalization following endovascular treatment of acute ischemic stroke: a systematic review and meta-analysis

BACKGROUND

Successful recanalization after endovascular thrombectomy serves as the primary endpoint in clinical trials and is a crucial predictor of long-term outcomes. Radiographic outcomes for various interventions have been shown to vary based on the type of interpreter, including the site interventionalist compared with an independent reader.

OBJECTIVE

To compare angiographic outcomes in stroke thrombectomy procedures based on the type of reader.

METHODS

A systematic literature search was conducted in Medline, EMBASE, Scopus, and Web-of-Science through February 2022. We included primary studies that reported core laboratory-read and operator angiographic outcomes after mechanical thrombectomy for ischemic stroke. Furthermore, study-defined successful recanalization data were collected.

RESULTS

Eight studies were included with 4797 patients, 51.2% of whom were male. Four thousand, four hundred and thirty-one patients had core readings, and 4211 had operator readings. Study-defined successful recanalization was significantly higher for operator (84%, 3543/4211) examinations than for core laboratory-read (78.4%, 3476/4431) examinations (p<0.001; OR=1.462, 95% CI 1.175 to 1.819). The modified Thrombolysis in Cerebral Infarction (mTICI) scale score of ≥2 b was higher for operator (85%, 3341/3929) examinations than for core laboratory-read (78.6%, 3107/3952) examinations (p<0.001; OR=1.349, 95% CI 1.071 to 1.701). mTICI 3 was significantly higher for operator (54.6%, 1000/1832) examinations than for core laboratory-read (39.9%, 731/1832) examinations (p<0.001; OR=1.823, 95% CI 1.598 to 2.081).

CONCLUSION

Operator angiographic reads are statistically significantly higher than core laboratory-read readings following stroke thrombectomy, especially for complete recanalization. These differences should be considered when interpreting reports of angiographic outcomes after thrombectomy.

Family structure and substance use in 6,178 American Indian youth: a cross-sectional study

OBJECTIVE

Adolescents from single-parent families are at significantly higher risk of substance use compared to those from mother-father families. More than half of American Indian (AI) children live in single-parent families, the second highest percentage among all groups. Given the paucity of research pertaining to the role of family structure and substance use in the AI population, we sought to examine this relationship.

MATERIALS AND METHODS

Data from this study were obtained from the Substance Use Among American Indian Youth: Epidemiology and Etiology, [US], 2015-2020 study. Response variables of interest included age at first substance use, number of substances used, ever-use of substance, and substance use type (i.e., alcohol, cigarette, marijuana, etc.).

RESULTS

Living in a father-only or mother-only setting showed a similar pattern of drug use. There was a significant increase in the risk of cigarette, alcohol and marijuana use. For cigarettes, the odds ratio was (OR = 2.60, 95% CI 1.80-3.75) in father-only setting compared to (OR = 1.42, 95% CI 1.13-1.78) for mother only setting. Alcohol use showed (OR = 1.72, 95% CI 1.19-2.50 and OR = 1.40, 95% CI 1.12-1.74) for father-only and mother-only respectively and marijuana use showed (OR = 1.59, 95% CI 1.10-2.30 and OR = 1.54, 95% CI -1.24-1.92) for father-only and mother-only respectively.

CONCLUSIONS

Disturbed family structure is associated with increased risk of substance use among AI youth. This indicates the importance and need for policy and community level interventions to reduce youth substance exposure.

Mean Changes in Estimated Glomerular Filtration Rate in Patients Undergoing Percutaneous Nephrolithotomy Having Renal Stone Disease

Background

Urinary stone disease is associated with renal impairment because of obstruction and infection. Comorbidities include hypertension, dyslipidemia, diabetes, and impaired renal function. Furthermore, as recurrences are common in urolithiasis, such patients undergo many treatments throughout their life. Percutaneous nephrolithotomy (PCNL) is an effective treatment for renal stones with a diameter greater than 2 cm. The primary objective of this study was to observe the mean changes in estimated glomerular filtration rate (GFR) in patients undergoing PCNL having renal stone disease.

Methodology

This cross-sectional study was conducted for six months between June and November 2020 at a tertiary care hospital in Karachi, Pakistan. All male and female patients aged between 15 and 70 years who were diagnosed with renal stones using X-ray of the kidney, ureter, and bladder or using ultrasound of the abdomen and planned for PCNL were selected. Patients with any duration of kidney stone disease were included. Statistical Package for Social Sciences version 20.0 (IBM Corp., Armonk, NY, USA) was used to statistically analyze the data.

Results

The mean age of the patients was 41.11 ± 14.30 (17-70) years. A total of 61 (38.1%) patients were female and 99 (61.9%) were male. Mean preoperative GFR was 91.22 ± 5.88 mL/min which decreased to 83.64 ± 5.70 mL/min at 48 hours post-PCNL. GFR significantly decreased after surgery (p = 0.0001).

Conclusions

During early postoperative days, GFR was decreased in patients undergoing PCNL. Factors that may impair renal function should be avoided during the first few days after undergoing PCNL. Further large-scale studies are needed to investigate these changes in GFR in post-PCNL patients.

The Pattern of Dyslipidemia in Chronic Liver Disease Patients

Introduction Patients with chronic liver disease are expected to report derangements in serum lipid profiles. Lipid profile monitoring is not a part of the routine management of these patients in our hospital. Few recent studies show how lipid profile varies with the severity of disease and should be considered in the management planning of such patients. The objective of this study was to determine the pattern of dyslipidemia in chronic liver disease patients. Materials and methods A cross-sectional study was conducted involving 171 patients of all genders aged between 18 years and 60 years presenting with chronic liver disease with disease severity graded on Child-Pugh class as A, B, and C. Lipid profile was acquired in all these patients and was compared across various subgroups. Individual serum lipid parameters were graded as normal, high, or very high. Each patient was required to provide written informed consent. Statistical Package for Social Sciences (SPSS) version 21.0 (IBM Corp. Armonk, NY) was used to analyze data statistically, taking a p-value of ≤0.05 as significant. Results The mean age of patients was 51.2±7.3 years. The male to female ratio came out to be 1.5:1, with 103 (60.2%) male and 68 (39.8%) female patients included in the study. The disease was classified as Child-Pugh A in 20 (11.7%) patients, Child-Pugh B in 67 (39.2%) patients, and Child-Pugh C in 84 (49.1%) patients. Forty-four (25.7%) patients were hypertensive while 62 (36.3%) were diabetic. The mean body mass index (BMI) of these patients was 25.9±2.4 kg/m2. Mean serum values among Child-Pugh A, Child-Pugh B, and Child-Pugh C of low-density lipoproteins (LDL) (113.15±14.08 vs. 95.58±14.25 vs. 53.46±5.90 mg/dl; p-value 0.001), high-density lipoproteins (HDL) (50.60±3.19 vs. 40.70±2.95 vs. 35.40±3.88 mg/dl; p-value 0.001), total cholesterol (174.20±17.33 vs. 164.00±17.82 vs. 128.64±24.73 mg/dl; p-value 0.001), and triglycerides (127.15±8.98 vs. 100.84±27.12 vs. 93.36±25.56 mg/dl; p-value 0.001) decreased significantly with increasing severity of disease. Nineteen (11.1%) patients had hyperlipidemia (serum values of two or more parameters above normal) while 152 (88.9%) patients had normal lipid profile. When stratified, no statistically significant difference was found in the frequency of hyperlipidemia across various subgroups based on the patient's gender, age, duration, and severity of the disease, BMI, or diabetic and hypertensive status. Conclusions A substantial proportion of patients with chronic liver disease had hyperlipidemia which varied with the severity of disease on Child-Pugh classification. Routine monitoring of the lipid profile of such patients is necessary for timely identification and management of dyslipidemia to improve the outcome of such patients. It also suggests an important role of lipid profile in the risk stratification and treatment of chronic liver disease patients and warrants further studies in this regard.

The Outcomes of Extracorporeal Shock Wave Lithotripsy for High-Density Renal Stone on Non-Contrast Computed Tomography

Introduction Urinary lithiasis is usually managed by extracorporeal shock wave lithotripsy (ESWL). Patients are examined using non-contrast computed tomography (NCCT) in order to evaluate the feasibility of ESWL, according to where the stone is located and how big is its size. The objective of this study is to determine the outcomes of ESWL in patients having high-density renal stone, evaluated using NCCT. Materials and methods A descriptive case series study was conducted in the Department of Urology, Sindh Institute of Urology & Transplantation, Karachi for six months. Patients of either gender aged between 25-50 years, who presented with solitary renal and ureteric calculi of 0.5-2 cm in diameter and high-density renal stones [>750 hounsfield units (HU)] were enrolled. ESWL was performed and a satisfactory outcome was defined as complete stone clearance in less than or equal to three ESWL sessions. Statistical Package for Social Sciences (SPSS) (IBM Corp., Armonk, NY) was used to analyze frequencies and percentages of the number of ESWL sessions, complete renal stone clearances, and satisfactory outcomes at the end of 12 weeks. A p-value of <0.05 was considered significant. Results The mean age of the patient was reported to be 34.08 ± 9.53 years. 51.6% male preponderance was noticed. Renal and ureteric stones were found in 69.7% and 30.3% of patients, respectively. 21.3% of patients showed stone clearance after two ESWL sessions, 27% of patients after three ESWL sessions, and 51.6% of patients after four ESWL sessions. Stone clearance was found in 58.2% of patients and a satisfactory outcome was found in 42.6% of patients. Conclusions Our results signify a satisfactory outcome of extracorporeal shock wave lithotripsy for high-density renal stone on non-contrast computed tomography. Further studies on a larger scale are needed to validate these results.

Chromatographic Separation of the Novel Hypoglycemic Drug Mitiglinide in its Bulk Powder and Pharmaceutical Formulation: Forced Degradation and Validated Stability-Indicating HPTLC/Densitometry and HPLC/UV Methods

BACKGROUND

Mitiglinide (MTG) is one of meglitinides group which are used for treatment of type two diabetes mellitus.

OBJECTIVE

Mitiglinide (MTG) is a novel oral hypoglycemic drug. The present work adopts two stability-indicating chromatographic methods for determination of MTG after being exposed to forced degradation using 4 M methanolic HCl for 12 h.

METHODS

The first method is HPTLC/densitometry using methanol:chloroform:acetic acid (5:2.5:0.3 by volume) as the eluting system and silica gel 60 GF254 as the stationary phase; the separated bands were then scanned at 220 nm. The second method is HPLC/UV in which acetonitrile:methanol:0.05 M potassium dihydrogen orthophosphate (pH 3.5) (40:25:35 by volume) was used as the mobile phase and a Zorbax SB-C8 (250 × 4.6 mm, 5 µm) column as a stationary phase, at a flow rate of 1 mL/min and UV detection at 220 nm.

RESULTS

As a result of acid hydrolysis, two degradants were obtained. The first one was benzyl succinic acid to which this study was performed. The second one lacked configuration and was unreadable using UV spectrometry. Linearity was in the range of 8-48 µg/band MTG for HPTLC and 10-80 µg MTG for HPLC. LOD and LOQ values were 1.85 and 5.62 µg/band for the HPTLC method and 2.14 and 6.49 µg/mL for the HPLC method, respectively. The Recovery % was 100.03 ± 1.464 and 99.61 ± 1.44 using the HPTLC and HPLC methods, respectively. The relative standard deviations (RSD, %) for intra- and inter-day assays were 1.111 and 1.430 for the HPTLC method, respectively, and those for the HPLC method were 1.377 and 0.866, respectively. The RSD, %, for robustness testing was 1.162 (saturation time of mobile phase) and 1.592 (change in ratio of methanol content) for the HPTLC method and 1.377 (mobile phase composition), 1.713 (detector wavelength) and 1.770 (mobile phase flow rate) for the HPLC method.

CONCLUSIONS

The adopted methods were successfully applied for the determination of MTG in its pure form, in presence of its acid degradant and in its tablet dosage form.

HIGHLIGHTS

Statistical comparison between the results obtained from the developed methods and those obtained by the reported HPLC method showed no significance difference.

Simultaneous Determination of Phenylephrine Hydrochloride, Guaifenesin, and Chlorpheniramine Maleate in Cough Syrup by Gradient Liquid Chromatography

A simple and reliable high-performance liquid chromatographic method was developed for the simultaneous determination of mixture of phenylephrine hydrochloride (PHENYL), guaifenesin (GUAIF), and chlorpheniramine maleate (CHLO) either in pure form or in the presence of methylparaben and propylparaben in a commercial cough syrup dosage form. Separation was achieved on a C8 column using 0.005 M heptane sulfonic acid sodium salt (pH 3.4 0.1) and acetonitrile as a mobile phase by gradient elution at different flow rates, and detection was done spectrophotometrically at 210 nm. A linear relationship in the range of 30180, 1201800, and 1060 g/mL was obtained for PHENYL, GUAIF, and CHLO, respectively. The results were statistically analyzed and compared with those obtained by applying the British Pharmacopoeia (2002) method and showed that the proposed method is precise, accurate, and can be easily applied for the determination of the drugs under investigation in pure form and in cough syrup formulations.

Stability-Indicating Methods for Determination of Pyritinol Dihydrochloride in the Presence of Its Precursor and Degradation Product by Derivative Spectrophotometry

A first-derivative spectrophotometric (1D) method and a derivative-ratio zero-crossing spectrophotometric (1DD) method were used to determine pyritinol dihydrochloride (I) in the presence of its precursor (II) and its degradation product (III) with 0.1N hydrochloric acid as a solvet. Linear relationships were obtained in the ranges of 6–22 μg/mL for the (1D) method and 6–20 μg/mL for the (1DD) method. By applying the proposed methods, it was possible to determine pyritinol dihydrochloride in its pure powdered form with an accuracy of 100.36 ± 1.497% (n = 9) for the (1D) method and an accuracy of 99.92 ± 1.172% (n = 8) for the (1DD) method. Laboratory-prepared mixtures containing different ratios of (I), (II), and (III) were analyzed, and the proposed methods were valid for concentrations of ≤10% (II) and ≤50% (III). The proposed methods were validated and found to be suitable as stability-indicating assay methods for pyritinol in pharmaceutical formulations.

Selective Determination of Human Growth Hormone (Somatropin) in the Presence of Its Chemical Degradation Products

A rapid and sensitive HPLC method was developed and validated for selective determination of the human growth hormone (hGH) somatropin in the presence of its deamidated and oxidized degradation products. Reversed-phase chromatography with an acetonitrile and ammonium bicarbonate mobile phase in gradient elution mode was used. A short run time of 15 min allowed rapid and cost-effective analysis, with an average retention time of 7.4 min for native hGH, 6.2 min for its deamidated form, and 4.3 and 6 min for its oxidized variants. The method was validated for selectivity, linearity, and intra- and interday variations according to International Conference on Harmonization guidelines. The proposed method was successfully applied for rapid evaluation of the quantity of hGH during downstream processing, formulation, and storage.

Selective Determination of Human Growth Hormone (Somatropin) in the Presence of Its Chemical Degradation Products

A rapid and sensitive HPLC method was developedand validated for selective determination of thehuman growth hormone (hGH) somatropin in thepresence of its deamidated and oxidized degradationproducts. Reversed-phase chromatographywith an acetonitrile and ammonium bicarbonatemobile phase in gradient elution mode was used.A short run time of 15 min allowed rapid andcost-effective analysis, with an average retentiontime of 7.4 min for native hGH, 6.2 min for itsdeamidated form, and 4.3 and 6 min for its oxidizedvariants. The method was validated for selectivity,linearity, and intra- and interday variations accordingto International Conference on Harmonizationguidelines. The proposed method was successfullyapplied for rapid evaluation of the quantity ofhGH during downstream processing, formulation,and storage.

Robust Assessment of Molecular Size Distribution of Meningococcal AC Vaccine

The molecular size of meningococcal polysaccharides is an important physicochemical parameter that is related to immunogenicity and efficacy. A simple method for size-exclusion chromatography was developed, optimized, and applied for safe and rapid fractionation of meningococcal polysaccharide AC vaccine. Pooling of the fractions collected from size-exclusion chromatography was investigated and evaluated, rather than analyzing each fraction separately, for determining the percentages of meningococcal polysaccharide A and C that were eluted before the distribution coefficient of 0.5. Pooling is preferred rather than analyzing each fraction individually, as it is easily handled, faster, simpler, less expensive, more accurate, safe, and applicable. The developed method was validated and successfully applied for the determination of meningococcal polysaccharide vaccine serotype A and C in quality-control and commercial samples.

Stability Indicating Determination of Human Growth Hormone by Novel SE-LC Method

A selective, rapid size-exclusion chromatographic method was developed and validated for the separation of the human growth hormone (hGH) somatropin from its high-molecular-weight aggregates. Separation was achieved using a nontoxic mobile phase compared with the official method of the European Pharmacopoeia that uses 2-propanol in a mobile phase. The developed method used a YMC-Pack Diol (YMC Karasuma, Kyoto, Japan; 300 × 8.0 mm, 5 μm) analytical column. The mobile phase was formed with a pH 7phosphate buffer that was pumped at a flow rate of 1 mL/min with UV detection at 214 nm. The overall run time was 20 min and the average retention times were found to be 10.21 min for the monomer peak, 9.52 min for the dimer peak, and 9.14 min for the higher aggregate. This method was validated in terms of selectivity, linearity, and intra- and interday variations according to the International Conference on Harmonization guidelines. The developed method was applied as a rapid tool for evaluating the stability of stressed samples of hGH subjected to different temperature, agitation, and repeated freeze-thaw cycles. The developed method was successfully applied for the assessment of the quality and quantity of hGH during downstream processing, formulation, and storage.

Monitoring of the degradation kinetics of diatrizoate sodium to its cytotoxic degradant using a stability-indicating high-performance liquid chromatographic method

The X-ray diagnostic agent sodium diatrizoate (DTA) was studied for chemical degradation. The 3,5-diamino derivative was found to be the alkaline and acidic degradation product. The 3,5-diamino degradate is also the synthetic precursor of DTA and it is proved to have cytotoxic and mutagenic effects. A sensitive, selective and precise high-performance liquid chromatographic stability-indicating method for the determination of DTA in the presence of its acidic degradation product and in pharmaceutical formulation was developed and validated. Owing to the high toxicity of the degradation product, the kinetics of the acidic degradation process was monitored by the developed RP-HPLC method. The reaction was found to follow pseudo-first order kinetics. The kinetic parameters such as rate constant (K) and half-life (t_½ ) were calculated under different temperatures and acid concentrations; activation energy was estimated from the Arrhenius plot. The developed RP-HPLC method depends on isocratic elution of a mobile phase composed of methanol-water (25:75 v/v; pH adjusted with phosphoric acid), and UV detection at 238 nm. The method showed good linearity over a concentration range of 2-100 μg/mL with mean percentage recovery of 100.04 ± 1.07. The selectivity of the proposed method was tested using laboratory-prepared mixtures. The proposed method has been successfully applied to the analysis of DTA in pharmaceutical dosage forms without interference from other dosage form additives and the results were statistically compared with the official USP method. Validation of the proposed method was performed according to International Conference on Harmonization guidelines.

Phospholipidomic identification of potential serum biomarkers in dengue fever, hepatitis B and hepatitis C using liquid chromatography-electrospray ionization-tandem mass spectrometry

The serum phospholipid (PL) profiles of healthy volunteers (HE) and patients with recently diagnosed dengue fever (DF), hepatitis B (HBV), and hepatitis C (HCV) were investigated using liquid chromatography-ion trap-mass spectrometry (LC-IT-MS) and liquid chromatography-triple quad-mass spectrometry (LC-TQ-MS). Major PLs, including lyso-phosphatidylcholins (LPCs), phosphatidylcholins (PCs), phosphatidylinositols (PIs), phosphatidylethanolamines (PEs) and phosphatidylserines (PSs), were characterized in human serum using LC-IT-MS. Thirty-five PLs were quantified using seven non-endogenous odd-carbon PL standards. An MS search protocol for the identification of PLs is described. The analytical method was optimized to achieve maximum recovery and detection. PLs were detected with minimal ionization suppression. The PLs species were characterized on the basis of (i) MS(2) peaks due to polar head, (ii) precursor ion or neutral loss scans, (iii) identification of fatty acid, (iv) identification of sn-1 and sn-2 fatty acid. The quantitation data were subjected to principal component analysis (PCA), and a significant difference was observed between the PL profiles of the investigated diseases and those of HE subjects. The significance of the changes in each lipid among the four groups was statistically assessed using one-way analysis of variance (ANOVA) followed by Bonferroni post hoc multiple comparison. The serum profiles of 28 PLs were determined to be significantly different and enabled the discrimination between HE individuals and the studied patients. Potentially dysregulated PLs were considered as differentiating biomarkers to diagnose DF, HBV, and HCV.

Optimization of photocatalytic degradation of meloxicam using titanium dioxide nanoparticles: application to pharmaceutical wastewater analysis, treatment, and cleaning validation

Meloxicam is a commonly prescribed nonsteroidal anti-inflammatory drug with analgesic and fever-reducing effects. In this study, photocatalytic degradation of meloxicam in the presence of TiO2 nanoparticles (TiO2NP) was optimized and applied for pharmaceutical wastewater treatment. A validated stability-indicating orthogonal testing protocol (reversed-phase (RP)-HPLC and capillary zone electrophoresis) was developed and validated for monitoring of meloxicam concentration in the presence of its photodegradation products. Fractional factorial design was employed in order to investigate the effects of pH, irradiation time, UV light intensity, TiO2NP loading, and initial meloxicam concentration on the efficiency of the process. The light intensity was found as the most significant parameter followed by irradiation time and concentration, respectively. The most influencing interactions were noted between irradiation time-concentration and irradiation time-light intensity. The kinetics of meloxicam degradation was investigated at the optimum set of experimental conditions. The protocol was successfully applied for treatment of incurred water samples collected during various cleaning validation cycles. A percentage degradation of 77.34 ± 0.02 % was achieved upon irradiation of samples containing 64.57 ± 0.09 μg/mL with UV light (1012 μW/cm(2), 8 h) in the presence of 0.4 mg/mL TiO2NP at pH 9.0 ± 0.05. Treatment of wastewaters collected during the cleaning validation of each product separately rather than the combined waste should result in a significant improvement in the economics of pharmaceutical wastewater treatment. This could be attributed to the relatively small waste volumes and the ability to tailor the experimental conditions to achieve maximum efficiency.

A comparative study between three stability indicating spectrophotometric methods for the determination of diatrizoate sodium in presence of its cytotoxic degradation product based on two-wavelength selection

Three sensitive, selective, and precise stability indicating spectrophotometric methods for the determination of the X-ray contrast agent, diatrizoate sodium (DTA) in the presence of its acidic degradation product (highly cytotoxic 3,5-diamino metabolite) and in pharmaceutical formulation, were developed and validated. The first method is ratio difference, the second one is the bivariate method, and the third one is the dual wavelength method. The calibration curves for the three proposed methods are linear over a concentration range of 2-24 μg/mL. The selectivity of the proposed methods was tested using laboratory prepared mixtures. The proposed methods have been successfully applied to the analysis of DTA in pharmaceutical dosage forms without interference from other dosage form additives. The results were statistically compared with the official US pharmacopeial method. No significant difference for either accuracy or precision was observed.

Stability indicating spectrophotometric and spectrodensitometric methods for the determination of diatrizoate sodium in presence of its degradation product

Three sensitive, selective, and precise stability indicating methods for the determination of the X-ray contrast agent, diatrizoate sodium (DTA), in the presence of its acidic degradation product (highly cytotoxic 3,5 diamino metabolite) and in pharmaceutical formulation were developed and validated. The first method is a first derivative (D1) spectrophotometric one, which allows the determination of DTA in the presence of its degradate at 231.2 nm (corresponding to zero crossing of the degradate) over a concentration range of 2-24 μg/mL with mean percentage recovery 99.95±0.97%. The second method is the first derivative of the ratio spectra (DD1) by measuring the peak amplitude at 227 nm over the same concentration range as D1 spectrophotometric method, with mean percentage recovery 99.99±1.15%. The third method is a TLC-densitometric one, where DTA was separated from its degradate on silica gel plates using chloroform:methanol:ammonium hydroxide (20:10:2 by volume) as a developing system. This method depends on quantitative densitometric evaluation of thin layer chromatogram of DTA at 238 nm over a concentration range of 4-20 μg/spot, with mean percentage recovery 99.88±0.89%. The selectivity of the proposed methods was tested using laboratory-prepared mixtures. The proposed methods have been successfully applied to the analysis of DTA in pharmaceutical dosage forms without interference from other dosage form additives. The results were statistically compared with the official US pharmacopeial method. No significant difference for either accuracy or precision was observed.

A comparative study of novel spectrophotometric resolution techniques applied for pharmaceutical mixtures with partially or severely overlapped spectra

Simultaneous determination of mixtures of lidocaine hydrochloride (LH), flucortolone pivalate (FCP), in presence of chlorquinaldol (CQ) without prior separation steps was applied using either successive or progressive resolution techniques. According to the concentration of CQ the extent of overlapping changed so it can be eliminated from the mixture to get the binary mixture of LH and FCP using ratio subtraction method for partially overlapped spectra or constant value via amplitude difference followed by ratio subtraction or constant center followed by spectrum subtraction spectrum subtraction for severely overlapped spectra. Successive ratio subtraction was coupled with extended ratio subtraction, constant multiplication, derivative subtraction coupled constant multiplication, and spectrum subtraction can be applied for the analysis of partially overlapped spectra. On the other hand severely overlapped spectra can be analyzed by constant center and the novel methods namely differential dual wavelength (D(1) DWL) for CQ, ratio difference and differential derivative ratio (D(1) DR) for FCP, while LH was determined by applying constant value via amplitude difference followed by successive ratio subtraction, and successive derivative subtraction. The spectra of the cited drugs can be resolved and their concentrations are determined progressively from the same ratio spectrum using amplitude modulation method. The specificity of the developed methods was investigated by analyzing laboratory prepared mixtures and were successfully applied for the analysis of pharmaceutical formulations containing the cited drugs with no interference from additives. The proposed methods were validated according to the ICH guidelines. The obtained results were statistically compared with those of the official or reported methods; using student t-test, F-test, and one way ANOVA, showing no significant difference with respect to accuracy and precision.

Assessment of natural and artificial radioactivity levels and radiation hazards and their relation to heavy metals in the industrial area of Port Said city, Egypt

A detailed gamma ray spectrometry survey was carried out to make an action in environmental impact assessment of urbanization and industrialization on Port Said city, Egypt. The concentrations of the measured radioelements U-238, Th-232 in ppm, and K-40 %, in addition to the total counts of three selected randomly dumping sites (A, B, and C) were mapped. The concentration maps represent a base line for the radioactivity in the study area in order to detect any future radioactive contamination. These concentrations are ranging between 0.2 and 21 ppm for U-238 and 0.01 to 13.4 ppm for Th-232 as well as 0.15 to 3.8 % for K-40, whereas the total count values range from 8.7 to 123.6 uR. Moreover, the dose rate was mapped using the same spectrometer and survey parameters in order to assess the radiological effect of these radioelements. The dose rate values range from 0.12 to 1.61 mSv/year. Eighteen soil samples were collected from the sites with high radioelement concentrations and dose rates to determine the activity concentrations of Ra-226, Th-232, and K-40 using HPGe spectrometer. The activity concentrations of Ra-226, Th-232, and K-40 in the measured samples range from 18.03 to 398.66 Bq kg(-1), 5.28 to 75.7 Bq kg(-1), and 3,237.88 to 583.12 Bq kg(-1), respectively. In addition to analyze heavy metal for two high reading samples (a 1 and a 10) which give concentrations of Cd and Zn elements (a 1 40 ppm and a 10 42 ppm) and (a 1 0.90 ppm and a 10 0.97 ppm), respectively, that are in the range of phosphate fertilizer products that suggested a dumped man-made waste in site A. All indicate that the measured values for the soil samples in the two sites of three falls within the world ranges of soil in areas with normal levels of radioactivity, while site A shows a potential radiological risk for human beings, and it is important to carry out dose assessment program with a specifically detailed monitoring program periodically.

Gallic acid magnetic nanoparticles for photocatalytic degradation of meloxicam: synthesis, characterization and application to pharmaceutical wastewater treatment

Gallic acid magnetic nanoparticles for photocatalytic degradation of meloxicam in pharmaceutical wastewater.

Comparative study between univariate spectrophotometry and multivariate calibration as analytical tools for simultaneous quantitation of Moexipril and Hydrochlorothiazide

Three simple, accurate, reproducible, and selective methods have been developed and subsequently validated for the simultaneous determination of Moexipril (MOX) and Hydrochlorothiazide (HCTZ) in pharmaceutical dosage form. The first method is the new extended ratio subtraction method (EXRSM) coupled to ratio subtraction method (RSM) for determination of both drugs in commercial dosage form. The second and third methods are multivariate calibration which include Principal Component Regression (PCR) and Partial Least Squares (PLSs). A detailed validation of the methods was performed following the ICH guidelines and the standard curves were found to be linear in the range of 10-60 and 2-30 for MOX and HCTZ in EXRSM method, respectively, with well accepted mean correlation coefficient for each analyte. The intra-day and inter-day precision and accuracy results were well within the acceptable limits.

Comparative study between univariate spectrophotometry and multivariate calibration as analytical tools for quantitation of Benazepril alone and in combination with Amlodipine

Four simple, accurate, reproducible, and selective methods have been developed and subsequently validated for the determination of Benazepril (BENZ) alone and in combination with Amlodipine (AML) in pharmaceutical dosage form. The first method is pH induced difference spectrophotometry, where BENZ can be measured in presence of AML as it showed maximum absorption at 237nm and 241nm in 0.1N HCl and 0.1N NaOH, respectively, while AML has no wavelength shift in both solvents. The second method is the new Extended Ratio Subtraction Method (EXRSM) coupled to Ratio Subtraction Method (RSM) for determination of both drugs in commercial dosage form. The third and fourth methods are multivariate calibration which include Principal Component Regression (PCR) and Partial Least Squares (PLSs). A detailed validation of the methods was performed following the ICH guidelines and the standard curves were found to be linear in the range of 2-30μg/mL for BENZ in difference and extended ratio subtraction spectrophotometric method, and 5-30 for AML in EXRSM method, with well accepted mean correlation coefficient for each analyte. The intra-day and inter-day precision and accuracy results were well within the acceptable limits.

CD14(+) HLA-DR low/(-) monocytes as indicator of disease aggressiveness in B-cell non-Hodgkin lymphoma

INTRODUCTION

This study aimed to assess the correlation between the percentage of CD14(+) HLA-DR(low/-) immunosuppressive monocytes, plasma arginase 1 level, and disease aggressiveness in patients with B-cell non-Hodgkin lymphoma.

METHODS

Forty-two patients with B-cell non-Hodgkin lymphoma and 20 healthy volunteers were enrolled in this study. Peripheral blood CD14+ HLA-DR(low/-) monocytes were detected by Flow cytometry, and their correlation with disease relapse and refractoriness was analyzed.

RESULTS

The percent of CD14(+) HLA-DR(low/-) monocytes was significantly higher in the lymphoma patients than in the healthy controls (control, 9.3 ± 4%; lymphoma, 35.8 ± 20.2%; P < 0.0001), higher in stage III& IV than stage II (stage II, 26.48 ± 17%, n = 26; stage III & IV, 50.8 ± 15.4%, n = 16; P < 0.0001), more in diffuse large cell lymphoma than other pathology types and in relapsed/refractory patients than in patients who achieved remission during follow-up (relapsed/refractory, n = 18, 45.7 ± 16.7%; remission, n = 16, 21.4 ± 16.2%; P < 0.0001). The arginase I level correlated with increased percent of CD14(+) HLA-DR(low/-) monocytes (P < 0.0001).

CONCLUSION

Increased CD14(+) monocytes with loss of HLA expression were seen in patients with higher stage disease, more aggressive pathology, and in relapse or refractoriness to treatment. Identifying therapeutic strategies to overcome the suppressive properties of these monocytes could be of value.

Successive spectrophotometric resolution as a novel technique for the analysis of ternary mixtures of pharmaceuticals

A novel spectrophotometric technique was developed for the simultaneous determination of ternary mixtures, without prior separation steps. This technique was called successive spectrophotometric resolution technique. The technique was based on either the successive ratio subtraction or successive derivative subtraction. The mathematical explanation of the procedure was illustrated. In order to evaluate the applicability of the methods a model data as well as an experimental data were tested. The results from experimental data related to the simultaneous spectrophotometric determination of lidocaine hydrochloride (LH), calcium dobesilate (CD) and dexamethasone acetate (DA); in the presence of hydroquinone (HQ), the degradation product of calcium dobesilate were discussed. The proposed drugs were determined at their maxima 202 nm, 305 nm, 239 nm and 225 nm for LH, CD, DA and HQ respectively; by successive ratio subtraction coupled with constant multiplication method to obtain the zero order absorption spectra, while by applying successive derivative subtraction they were determined at their first derivative spectra at 210 nm for LH, 320 nm or P(292-320) for CD, 256 nm or P(225-252) for DA and P(220-233) for HQ respectively. The calibration curves were linear over the concentration range of 2-20 μg/mL for both LH and DA, 6-50 μg/mL for CD, and 3-40 μg/mL for HQ. The proposed methods were checked using laboratory-prepared mixtures and were successfully applied for the analysis of pharmaceutical formulation containing the cited drugs with no interference from other dosage form additives. The proposed methods were validated according to the ICH guidelines. The obtained results were statistically compared with those of the official BP methods for LH, DA, and CD, and with the official USP method for HQ; using student t-test, F-test, and one way ANOVA, showing no significant difference with respect to accuracy and precision.

Separation and determination of clopidogrel and its impurities by capillary electrophoresis

Clopidogrel bisulphate, an anti-platelet drug, has been separated from its impurities, namely impurity A, B and C by capillary zone electrophoresis (CZE) using uncoated fused-silica capillary (50.0 microm internal diameter, 31.2cm total length). Four factors affected the separation: buffer concentration, pH of the buffer, concentration of the chiral selector and the applied voltage. Optimization and robustness studies were performed with the aid of reduced central composite experimental design. The buffer used was triethylamine-phosphoric acid and the chosen chiral selector was sulphated beta-cyclodextrin (SCD). The best separation was achieved by using 10mM buffer, pH 2.3, containing 5% (mass/volume (m/v)) SCD. Reversed polarity mode was used with an applied voltage of -12kV and the capillary temperature was maintained at 20 degrees C. The method was validated for quantitative determination of the drug. It offered a limit of detection (LOD) of 0.13 microg/ml, a limit of quantitation (LOQ) of 0.4 microg/ml, and a linearity range of 0.4-300 microg/ml. Commercial bulk samples were analyzed using the developed method.

Simultaneous determination of phenylephrine hydrochloride, guaifenesin, and chlorpheniramine maleate in cough syrup by gradient liquid chromatography

A simple and reliable high-performance liquid chromatographic method was developed for the simultaneous determination of mixture of phenylephrine hydrochloride (PHENYL), guaifenesin (GUAIF), and chlorpheniramine maleate (CHLO) either in pure form or in the presence of methylparaben and propylparaben in a commercial cough syrup dosage form. Separation was achieved on a C8 column using 0.005 M heptane sulfonic acid sodium salt (pH 3.4 +/- 0.1) and acetonitrile as a mobile phase by gradient elution at different flow rates, and detection was done spectrophotometrically at 210 nm. A linear relationship in the range of 30-180, 120-1800, and 10-60 microg/mL was obtained for PHENYL, GUAIF, and CHLO, respectively. The results were statistically analyzed and compared with those obtained by applying the British Pharmacopoeia (2002) method and showed that the proposed method is precise, accurate, and can be easily applied for the determination of the drugs under investigation in pure form and in cough syrup formulations.

Validated stability-indicating methods for determination of cilostazol in the presence of its degradation products according to the ICH guidelines

Sensitive and selective stability-indicating assay methods (SIAMs) are suggested for the determination of cilostazol (CIL) in the presence of its acid, alkaline and oxidative degradation products. Developing SIAMs is necessary to carry out any stability study. Stress testing of CIL was performed according to the International Conference on Harmonization (ICH) guidelines in order to validate the stability-indicating power of the analytical procedures. Stress testing showed that CIL underwent acid, alkaline and oxidative degradation; on the other hand, it showed stability towards photo- and thermal degradation. Two chromatographic SIAMs were developed, namely HPLC and HPTLC methods. The concentration range and the mean percentage recovery were 1.0-31.0 microg/ml and 99.96+/-0.46 and 0.6-14.0 microg/spot and 99.88+/-1.10 for HPLC and HPTLC methods, respectively. In addition, derivative spectrophotometric methods were developed in order to determine CIL in the presence of its acid degradation product; these were performed by using the third derivative spectra (3D) and the first derivative of the ratio spectra (1DD) methods. The linearity range and the mean percentage recovery were 2.0-34.0 microg/ml and 100.27+/-1.20 for the (3D) method, while they were 2.0-30.0 microg/ml and 99.94+/-1.18 for the (1DD) method. Also, two chemometric-assisted spectrophotometric methods, based on using partial least squares (PLS) and concentration residual augmented classical least squares method (CRACLS), for the determination of CIL were developed. Both methods were applied on zero order spectra of the mixtures of CIL and its acid degradation product, the mean percentage recovery was 100.03+/-1.09 and 99.91+/-1.27 for PLS and CRACLS, respectively. All methods were validated according to the International Conference on Harmonization (ICH) guidelines and applied on bulk powder and pharmaceutical formulations.

Stability-indicating spectrophotometric and spectrofluorimetric methods for determination of alfuzosin hydrochloride in the presence of its degradation products

Validated stability-indicating spectrophotometric and spectrofluorimetric assays (SIAMs) were developed for the determination of alfuzosin hydrochloride (ALF) in the presence of its oxidative, acid, and alkaline degradation products. Three spectrophotometric methods were suggested for the determination of ALF in the presence of its oxidative degradation product; these included the use of zero order (0D), first order (1D), and third order (3D) spectra. The absorbance was measured at 330.8 nm for (0D) method, while the amplitude of first derivative (1D) method and that of third derivative (3D) method were measured at 354.0 and 241.2 nm, respectively. The linearity ranges were 1.0-40.0 microg/ml for (0D) and (1D) methods, and 1.0-10.0 microg/ml for (3D) method. Two spectrofluorimetric methods were developed, one for determination of ALF in the presence of its oxidative degradation product and the other for its determination in the presence of its acid or alkaline degradation products. The first method was based on measuring the native fluorescence of ALF in deionized water using lamda(excitation) 325.0 nm and lamda(emission) 390.0 nm. The linearity range was 50.0-750.0 ng/ml. This method was also used to determine ALF in human plasma with the aid of a suggested solid phase extraction method. The second method was used for determination of ALF via its acid degradation product. The method was based on the reaction of fluorescamine with the primary aliphatic amine group produced on the degradation product moiety. The reaction product was determined spectrofluorimetrically using lamda(excitation) 380.0 nm and lamda(emission) 465.0 nm. The linearity range was 100.0-900.0 ng/ml. All methods were validated according to the International Conference on Harmonization (ICH) guidelines, and applied to bulk powder and pharmaceutical formulations.

Determination of Tetraconazole and Diniconazole Fungicide Residues in Tomatoes and Green Beans by Capillary Gas Chromatography

A sensitive gas chromatographic method using an electron-capture detector (ECD) has been developed for the determination of tetraconazole and diniconazole fungicide residues in tomatoes and green beans. The developed method consists of extraction with methanol, partition with methylene chloride, and column chromatographic clean-up, followed by capillary gas chromatographic determination. The recoveries of both fungicides were greater than 90% for both plant samples. The limits of determination of the method were 0.001 ppm for both fungicides. The method was applied to determine residues and the rate of disappearance of tetraconazole and diniconazole from tomatoes and green beans [open field treatment, 50 cc of Domark 10% EC (emulsifiable concentrate), and 35 cc of Sumi-eight 5% EC; both for 100 l of water]. The fungicides incorporated into the plants decreased rapidly with a half-life around 3 days for diniconazole and from 4.5 to 6.5 days for tetraconazole. No residues could be detected in the plants during the period of study of 21 days after field application. Hence, the plants could be used safely after that period of time.

Colorectal cancer in a population with endemic Schistosoma mansoni: is this an at-risk population?

PURPOSE

Chronic infection with schistosomiasis has been clearly associated with the development of bladder cancer, and infestation is associated with a high incidence of colorectal cancer in endemic populations. Despite this association, the potential role of alterations in tumor suppressor genes colorectal cancers has never been evaluated in an endemically infected population. The aim of this paper was to compare histopathologic and genetic changes in schistosomal colitis-associated colorectal cancer (SCC) with colorectal cancer in a group of patients from the same population not affected by the disease (NDCC).

MATERIALS AND METHODS

Sixty patients were included in this study: SCC-40, NDCC-20. Data collected included age, sex, clinical presentation, presence of synchronous tumors, histopathology, and clinical stage. p53, DCC (deleted in colorectal cancer gene), and mismatch repair genes (MLH1 and MSH2) were studied using immunohistochemical staining.

RESULTS

Patients with SCC were significantly younger than the NDCC group (34.52+/-11.22 years vs 50.73+/-12.75 years, p=0.02). Mucinous adenocarcinoma occurred significantly more frequently in SCC (35 vs 10%, p=0.02). SCC tumors were more frequently stage III or IV, and significantly more synchronous tumors were present in the affected group (SCC-8/40 vs NDCC-1/20, p=0.05). p53 staining was far more frequent in SCC (SCC-32/40 vs NDCC-8/20, p=0.006). DCC expression was similar in two groups. There were only four cases, three in SCC and one in NDCC, that showed microsatellite instability.

CONCLUSION

The data suggest that schistosomal colitis is more commonly associated with earlier onset of multicentric colorectal cancer, high percentage of mucinous adenocarcinoma, and presents at an advanced stage. The identification of a higher incidence of altered p53 expression in the SCC group raises the possibility of an association between schistosomiasis and alterations in p53 activation as an inciting event in colorectal cancer development.

Utilization of 4-chloro-7-nitro-2,1,3-benzoxadiazole (NBD-Cl) for kinetic spectrophotometric assay of befunolol hydrochloride in its pharmaceutical formulation

A simple, accurate, precise, and sensitive kinetic spectrophotometric method for determination of befunolol hydrochloride is described. The method is based on the formation of a colored product with 4-chloro-7-nitro-2,1,3-benzoxadiazole (NBD-Cl) in methanol at 70 degrees C for 45 min. The red-colored product was measured at 523 nm. The optimization of various experimental conditions is described; Beer's law was obeyed in the range 15.25 x 10(-6) to 122.04 x 10(-6) M. The results obtained showed good recoveries (100.1 +/- 0.80%). Application of the proposed method to a pharmaceutical formulation was successfully achieved. The determination of befunolol hydrochloride by fixed time, fixed concentration, and rate constant methods was feasible with the calibration equation obtained. However, the fixed time method proved to be more applicable.

Stability-indicating methods for determination of pyritinol dihydrochloride in the presence of its precursor and degradation product by derivative spectrophotometry

A first-derivative spectrophotometric (1D) method and a derivative-ratio zero-crossing spectrophotometric (1DD) method were used to determine pyritinol dihydrochloride (I) in the presence of its precursor (II) and its degradation product (III) with 0.1N hydrochloric acid as a solvent. Linear relationships were obtained in the ranges of 6-22 microg/mL for the (1D) method and 6-20 microg/mL for the (1DD) method. By applying the proposed methods, it was possible to determine pyritinol dihydrochloride in its pure powdered form with an accuracy of 100.36 +/- 1.497% (n = 9) for the (1D) method and an accuracy of 99.92 +/- 1.172% (n = 8) for the (1DD) method. Laboratory-prepared mixtures containing different ratios of (I), (II), and (III) were analyzed, and the proposed methods were valid for concentrations of < or = 10% (II) and < or = 50% (III). The proposed methods were validated and found to be suitable as stability-indicating assay methods for pyritinol in pharmaceutical formulations.

Derivative spectrophotometric and fluorimetric methods for determination of rofecoxib in tablets and in human plasma in presence of its photo-degradation product

Rofecoxib (I) has been determined in the presence of its photo-degradation product (II) using first derivative spectrophotometry ((1)D) and first derivative of the ratio spectra ((1)DD) by measuring the amplitude at 316.3 and 284 nm for (1)D and (1)DD, respectively. (I) can be determined in the presence of up to 70% and 80% of (II) by the (1)D and (1)DD, respectively. The linearity range of both the methods was the same (5.8-26.2 microg ml(-1)) with mean percentage recovery of 100.08 +/- 0.84 and 100.06 +/- 1.06 for (1)D and (1)DD, respectively. (1)D method was used to study kinetics of (I) photo-degradation that was found to follow a first-order reaction. The t(1/2) was 20.2 min while K (reaction rate constant) was 0.0336 mol min(-1). Both methods were applied to the analysis of (I) in bulk powder and in pharmaceutical formulations. Also a spectrofluorimetric method is described to determine (I) at very low concentrations (25-540 ng ml(-1)) where (I) is converted to its photo-degradate (II), which possesses a native fluorescence that could be measured. The proposed method was applied for the analysis of tablets containing rofecoxib as well as to rofecoxib-spiked human plasma.

Concentrations of salinomycin in eggs and tissues of laying chickens fed medicated feed for 14 days followed by withdrawal for 3 days

Laying chickens were fed medicated feed containing various concentrations of sodium salinomycin (SAL) for 14 days followed by a 3 day withdrawal period. Eggs, collected during treatment and withdrawal, tissues and ovarian yolk of birds slaughtered after 0, 1, and 3 days' withdrawal were extracted and analysed by high performance liquid chromatography (HPLC). Tissues, ovarian yolk and freeze-dried egg albumen and yolk were extracted with acetone, followed by partitioning with petroleum ether and HPLC analysis. Albumen was extracted with methanol and analysed without further clean-up. Salinomycin was detected at 520 nm after post-column reaction with vanillin at 95 degrees C. Recoveries of fortified salinomycin from freeze-dried eggs (albumen and yolk) and tissue, premix and feed were nearly quantitative (> 90%), except liver which was < 85%. The detection limit was estimated to be 5 ng g-1, with the practical quantifiable limit being about 10 ng g-1. Highest SAL concentrations were in the more fatty components such as egg yolk, ovarian yolk and subcutaneous fat. SAL residues in other tissues were generally low and followed the order liver, kidney, thigh and breast muscles. SAL residues were dependent on the SAL concentration in feed and declined rapidly during withdrawal.