Certification of caffeine reference material purity by ultraviolet/visible spectrophotometry and high-performance liquid chromatography with diode-array detection as two independent analytical methods

Caffeine reference material certified for purity is produced worldwide, but no research work on the details of the certification process has been published in the literature. In this paper, we report the scientific details of the preparation and certification of pure caffeine reference materials. Caffeine was prepared by extraction from roasted and ground coffee by dichloromethane after heating in deionized water mixed with magnesium oxide. The extract was purified, dried, and bottled in dark glass vials. Stratified random selection was applied to select a number of vials for homogeneity and stability studies, which revealed that the prepared reference material is homogeneous and sufficiently stable. Quantification of caffeine purity % was carried out using a calibrated UV/visible spectrophotometer and a calibrated high-performance liquid chromatography with diode-array detection method. The results obtained from both methods were combined to drive the certified value and its associated uncertainty. The certified value of the reference material purity was found to be 99.86% and its associated uncertainty was ±0.65%, which makes the candidate reference material a very useful calibrant in food and drug chemical analysis.     

Inflammatory pseudotumor of the nasopharynx with spread along the trigeminal nerve

Inflammatory pseudotumor of the nasopharynx is a rare diagnosis that is often misinterpreted as carcinoma or lymphoma. It has been referred to as a tumefactive fibroinflammatory lesion, idiopathic pseudotumor, and fibrosing inflammatory pseudotumor. We present a rare case of a 40-year-old African American female from Kenya with inflammatory pseudotumor of the nasopharynx with perineural spread of disease along the trigeminal nerve to discuss the diagnosis and treatment of such an uncommon entity.     

Factor VII deficiency detected in pregnancy: a case report.

Factor VII deficiency is a rare hereditary coagulation disorder with an incidence estimated at 1 in 500,000 individuals. In this report, we describe the 13th case in pregnancy. The diagnosis of severe factor VII deficiency (factor VII level <5%) was established at 10 weeks' gestation after initial laboratory testing showed a markedly prolonged prothrombin time and a normal activated partial thromboplastin time. There was a history of two preterm deliveries, but there was no evidence of previous bleeding manifestations. Antenatal progress of the index pregnancy was unremarkable. Prophylactic treatment with fresh frozen plasma was started at the onset of labor and the patient had a vaginal delivery of a live girl at 36 weeks' gestation. There was no postpartum hemorrhage and mother and newborn were discharged in good condition. The patient's postpartum level of factor VII remained undetectable. Two aspects are outlined: the absence of any significant increase in factor VII clotting activity during this pregnancy and the need to give replacement therapy at labor in patients with severe factor VII deficiency to decrease the risk of postpartum hemorrhage.     

Cerebral oligodendrogliomas in children: an analysis of 15 cases

The cases of 15 children operated on for cerebral pure oligodendroglioma were studied. Two groups of children were distinguished. Group 1 children presented with epilepsy (7 cases); their tumor was histologically benign in all cases. These children are all alive after a median follow-up of 72 months; however, 2 of them presented with a local recurrence, which was operated on, and are actually disease-free. Group 2 children presented with intracranial hypertension (8 cases); the tumor was anaplastic in 7 cases. Despite postoperative radiotherapy and chemotherapy 6 children died; their median survival time was 17 months. The present series shows the existence of a clear correlation between clinical presentation, histological grading and survival in childhood cerebral oligodendrogliomas.     

Predicting proteinuria in hypertensive pregnancies with urinary protein-creatinine or calcium-creatinine ratio.

OBJECTIVE: Evaluate the value of random urinary protein-creatinine (PrCr) and calcium-creatinine (CaCr) ratios to predict 24-h proteinuria in hypertensive pregnancies. STUDY DESIGN: Spot urine samples were collected before routine 24-h urine collections from consecutive pregnant women with hypertension (n=83). Reliability of spot urinary PrCr and CaCr to detect significant proteinuria (>or=300 mg/day) using 24-h urine protein as 'gold-standard' was assessed by receiver-operating characteristic (ROC) curve. RESULTS: Fifty-one patients (61.4%) had significant proteinuria (45 pre-eclampsia, 5 superimposed pre-eclampsia, 1 renal hypertension). Area under ROC curve to predict proteinuria was 0.82 (95% confidence interval (CI) 0.73 to 0.92, P<0.001) for PrCr and 0.55 (95% CI 0.43 to 0.68, P=0.2) for CaCr. A cutoff value of >0.19 for PrCr best predicted significant proteinuria with sensitivity, specificity, positive and negative predictive values and likelihood ratios (positive and negative), respectively, of 80.4, 68.8, 80.4, 68.8%, 2.57 and 3.51. CONCLUSION: Spot urinary PrCr predicts total urinary protein excretion in hypertensive pregnancies.     

Appendectomy under local anaesthesia following conscious pain mapping with microlaparoscopy

The appendix is an under-appreciated source of chronic pelvic pain. Laparoscopic evaluation of the appendix is limited without intra- operative patient feedback on the presence and absence of pain. New techniques using local anaesthesia with conscious sedation have enabled us to perform operative laparoscopic surgery while the patient is awake. We report the first two cases of microlaparoscopic appendectomies performed under local anaesthesia with conscious sedation following diagnosis obtained during conscious pain mapping.      

Determinants of the length of episiotomy or spontaneous posterior perineal lacerations during vaginal birth

The objective of this study was to measure the length of episiotomy or spontaneous posterior perineal laceration and their relationship to perineal measurements and obstetric variables. The length of the perineum and genital hiatus and vertical length of episiotomy or posterior perineal tears were measured in 114 consecutive parturients with spontaneous singleton term deliveries. Seventy-four (65%) women underwent episiotomy while 40 (35%) sustained spontaneous posterior tears. Perineal or genital hiatus length was significantly correlated to episiotomy (r=0.34, p=0.003) or laceration (r=0.37, p=0.02) length, respectively. This association was significant (p=0.001) in a generalized linear model with duration of second stage of labor (p=0.005), degree of tear (p=0), and parity (p=0). Perineal length was significantly related to maternal age (p=0.036) and weight (p=0.037) and hiatal length (p=0). Short perineum and genital hiatus, long second stage of labor, and low parity are associated with longer posterior perineal injury.     

Sensitive colorimetric determination of copper (II) ions in some chemicals and multivitamins.

A sensitive and selective colorimetric method has been devised for the micro-determination of copper (II) ions in pure form, some chemicals and multivitamin preparations. The method depends on the formation of stable blue complexes in ammonia medium peaking at 615 nm between copper (II) ions, oxalyldihydrazide and one of the following aldehydes: 4-nitrobenzaldehyde, 2-nitrocinnamaldehyde and formaldehyde with minimum detection limits 0.1, 0.16 and 1.1 ppm, respectively. Several metal ions do not interfere. The optimum reaction conditions were studied and the results obtained were favorably comparable to the diethyldithiocarbamate method.