Artifactual formylation of the secondary amine of duloxetine hydrochloride by acetonitrile in the presence of titanium dioxide: implications for HPLC method development

Duloxetine hydrochloride, a secondary amine containing pharmaceutical, currently marketed as Cymbalta, is shown to undergo N-formylation as an artifact of sample preparation prior to HPLC analysis for impurities. The reaction was discovered as a result of an investigation into variability in the levels of N-formyl duloxetine observed upon HPLC analysis. The reaction is catalyzed by sonication and/or light in the presence of titanium dioxide and is proposed to occur via a radical-initiated mechanism. The mechanism is supported by controlled sample preparation studies with deuterium-labeled acetonitrile and LC/MS studies that showed incorporation of one deuterium into N-formyl duloxetine. This discovery is broadly relevant because sonication is commonly used to aid dissolution of pharmaceuticals in acetonitrile for HPLC analysis, titanium dioxide is a commonly used excipient, the amount of light found in modern analytical laboratories is sufficient to cause the reaction to occur, and secondary amines are present in the structures of many pharmaceuticals. The artifactual reaction was effectively eliminated by changing the sample solvent to methanol and replacing sonication with shaking to aid sample dissolution.

Lin-c-kit+ BM-derived stem cells repair Infarcted Heart

Myocardial infarction is one of the leading causes of death worldwide. Bone marrow contains different types of stem cells capable of differentiating into cardiomyocytes. Therefore, we hypothesized that bone marrow contains a lin-c-kit+ progenitor cell pool with the ability to home to the infarcted region and improve the cardiac function. BM-derived stem cells (BMSCs) from Green fluorescent protein (GFP) expressing transgenic mice C57BL/6 (n = 6) were isolated by c-kit labeled Microbeads. Lin-c-kit+ BMSCs co-cultured with rat neonatal cardiomyocytes were able to express cardiac marker and form intercellular connections with rat myocytes. Myocardial infarction was produced in the experimental animals C57BL/6 Wild type (n = 10) by permanent ligation of the Left anterior descending (LAD) artery. BMSCs enriched for c-kit were transplanted in the border zone area of the infarction. Cardiac function analyzed by Millar’s Apparatus after 4 weeks of transplantation showed improvement. BMSCs were able to form intercellular connections and new blood vessel formation as determined by Connexin 43 and CD31 respectively. Lin-c-kit⁺ BMSCs were able to align with the host myocardium, participate in angiogenesis and thus improve the cardiac function.

Lin-c-kit(+) BM-derived stem cells repair Infarcted Heart

Myocardial infarction is one of the leading causes of death worldwide. Bone marrow contains different types of stem cells capable of differentiating into cardiomyocytes. Therefore, we hypothesized that bone marrow contains a lin-c-kit+ progenitor cell pool with the ability to home to the infarcted region and improve the cardiac function. BM-derived stem cells (BMSCs) from Green fluorescent protein (GFP) expressing transgenic mice C57BL/6 (n = 6) were isolated by c-kit labeled Microbeads. Lin-c-kit+ BMSCs co-cultured with rat neonatal cardiomyocytes were able to express cardiac marker and form intercellular connections with rat myocytes. Myocardial infarction was produced in the experimental animals C57BL/6 Wild type (n = 10) by permanent ligation of the Left anterior descending (LAD) artery. BMSCs enriched for c-kit were transplanted in the border zone area of the infarction. Cardiac function analyzed by Millar's Apparatus after 4 weeks of transplantation showed improvement. BMSCs were able to form intercellular connections and new blood vessel formation as determined by Connexin 43 and CD31 respectively. Lin-c-kit(+) BMSCs were able to align with the host myocardium, participate in angiogenesis and thus improve the cardiac function.

Use of Hydrogenophaga pseudoflava penetration to quantitatively assess the impact of filtration parameters for 0.2-micrometer-pore-size filters

Filters rated as having a 0.2-microm pore size (0.2-microm-rated filters) are used in laboratory and manufacturing settings for diverse applications of bacterial and particle removal from process fluids, analytical test articles, and gasses. Using Hydrogenophaga pseudoflava, a diminutive bacterium with an unusual geometry (i.e., it is very thin), we evaluated passage through 0.2-microm-rated filters and the impact of filtration process parameters and bacterial challenge density. We show that consistent H. pseudoflava passage occurs through 0.2-microm-rated filters. This is in contrast to an absence of significant passage of nutritionally challenged bacteria that are of similar size (i.e., hydrodynamic diameter) but dissimilar geometry.

Evaluating adherence to medication in children and adolescents with HIV

OBJECTIVE

The study was aimed to evaluate the relationship between pharmacy supply, self-reported treatment adherence and HIV viral load in HIV-infected children.

METHODS

A retrospective (52 weeks) cohort study was conducted through the review of the existing databases. Pharmacy supply was classified as "home delivery" when the medications were delivered home and as "in pharmacy pick-up" when they were picked up at the pharmacy. Adherence was assessed through retrospective (3 days recall) self-report. Fisher's exact model, univariate and multivariate logistic regression analyses were used.

SETTINGS

The study collected data on 140 HIV-infected children (<18 years). Adherence, pharmacy supply information and HIV viral loads were obtained from clinical and research databases.

PATIENTS

The data from 127 HIV-infected children (60 boys and 67 girls; mean age 9.9 years) were collected.

MAIN OUTCOME MEASURES

Complete adherence (100%) was reported in only 24% of patients. With 40% of patients being rarely or never completely adherent, 64% of children achieved undetectable viral loads during the study period.

RESULTS

No association between pharmacy supply and self-reported adherence was found (p = 0.605). Self-reported adherence (p = 0.0328) and age (p = 0.025) were the significant predictors of reaching undetectable viral loads. Adolescents (>13 years) were significantly less likely to reach undetectable viral loads than children under 13 years (odds ratio 0.38; 95% CI 0.16 to 0.89).

CONCLUSION

In our study, pharmacy supply was not associated with self-reported adherence. Most importantly, adherence and age were significant predictors of reaching undetectable viral loads.

15-lipoxygenase-1 in colorectal cancer: a review

OBJECTIVE

Enzymes involved in the oxidative metabolism of n-6 polyunsaturated fatty acids, like lipoxygenase (LOX) and cyclooxygenase (COX), are significant in the pathogenesis of colorectal cancer. Of these enzymes, 15-LOX-1 is expressed in colon. Aim of this article is to describe the role and regulation of 15-LOX-1 in colorectal cancer and highlight its importance in cancer therapeutics.

METHODS

For our electronic literature research in PubMed and MEDLINE, key words related to 15-LOX-1 and colorectal cancer were used to find articles for this review.

RESULTS

From the evidences, we believe that 15-LOX-1 has anti-carcinogenic effects in colorectal cancer, dependent or independent of its metabolites, and is manifested through downstream pathways involving cGMP, PPAR, p53, p21 and NAG-1, increasing apoptosis and decreasing proliferation in cancer cells. Regulation of 15-LOX-1 expression is achieved at transcription level by global histone acetylation and may also be dependent on GATA-6, IL-4 and IL-13. Positive relationship exists between 15-LOX-1 and survival in colorectal cancer.

CONCLUSION

Evidences strongly support that therapeutic modulation of 15-LOX-1 may be a key to the treatment of colorectal cancer. However, it is still undecided whether the up-regulation of 15-LOX-1 alone can be sufficient to treat colorectal cancer and further studies are awaited.

Acute cytomegalovirus hepatitis in immunocompetent host

BACKGROUND

In inmunocompetent hosts, cytomegalovirus (CMV) infection is generally asymptomatic. It may however present as infectious mononucleosis. Serious complications have rarely been reported. We report three cases of acute CMV hepatitis in immunocompetent men for the first time from Bangladesh. All three presented to us with features of acute hepatitis of variable duration preceded by prodrome. Other probable causes of acute hepatitis were ruled out and none had any clinical stigmata of cirrhosis. All the three patients underwent uneventful recovery. Although more common in the immunocompromised, CMV can occasionally produce symptomatic hepatitis in the immunocompetent host. Disease is self limiting, but supportive measures are needed.

Fournier's gangrene: a dreadful disease

BACKGROUND

Although there is much consensus, certain controversies still exist regarding the pathology of Fournier's gangrene. The purpose of this study was to determine the prevalence of the disease in the catchment area of the three teaching hospitals, to identify the systemic predisposing factors and local aetiological factors, and to assess the recommended role of aggressive surgical debridement as a part of treatment.

MATERIALS AND METHODS

This prospective study was conducted in the surgical departments of three tertiary care hospitals of the Khyber Medical University, Peshawar, Pakistan, from 1 January 2002 to 30 June 2007. Detailed history and examination of all patients were carried out to reach the diagnosis of Fournier's gangrene. After initial resuscitation, patients were treated aggressively, including surgical debridement.

RESULTS

Sixty patients were studied in the study period. The male to female ratio was 5:1. The age range was 20-75 years with mean 47+17.4 (SD) years. The socioeconomic status of patients was poor (the average income was less than $50 per week) in 36 (60%) and 24 (40%) were middle class (the average income being $50-100 per week). Thirty-nine patients (65%) presented in the hot humid months of the year. Extent of the disease was scrotum in 18 patients (30%), perineum in 30 (50%) and abdominal wall in 12 (20%). Systemic predisposing factors identified in our study were diabetes mellitus in 20 (33.33%) patients, chronic alcohol abuse in two (3.33%) and long-standing steroid therapy in four (6.67%) while in 34 patients (56.67%) no cause was identified. The local aetiological origin of Fournier's gangrene was urogenital in 14 (23.33%) patients, anorectal in 10 (16.67%) and cutaneous in 8 (13.33%) and no local pathologies could be identified in 28 (46.67%) patients. The mean time interval between first symptom and initial treatment was 2.5 days with a range of 1-7 days. Number of debridement sessions per patient was 2-6 (mean, 3.15). Mean hospital stay was 31+7 (SD) with a range of 10-50 days. Morbidity was 80%. Four patients (6.67%) died. Three of these patients presented to hospital 5-6 days too late.

CONCLUSION

Fournier's gangrene is not an uncommon disease in South Asia. Systemic predisposition such as diabetes mellitus, long-standing steroid therapy, chronic alcoholism and even the hot humid season can contribute to this dreadful disease. Local causes in the form of urogenital, anorectal and cutaneous disorders may trigger this disease in some patients. Early recognition of disease and aggressive surgical debridement are the main treatments.

Phylogenetic analysis of ALAD and MGP genes related to lead toxicity

Experimental studies in our laboratory have established the role of delta-aminolevulinic acid dehydratase (ALAD) and matrix gamma-carboxyglutamic acid (MGP) gene polymorphisms in the etiology of lead toxicity. Polymorphisms in these genes influenced the levels of lead in subjects exposed to this metal. In extension to our studies, we aimed to investigate the possible role of these proteins in evolution by studying the phylogenetic relationship and divergence of ALAD and MGP genes using computational phylogenetic methods. The human ALAD and MGP protein sequences from various species were retrieved from Swiss-Prot database and were compared using Basic Local Alignment Search Tool. Multiple sequence alignment was carried out using ClustalW with defaults, and phylogenetic trees for both the genes were built using neighbor-joining method as in Mega software. Our study indicated that ALAD is a highly conserved protein with the same metal binding site distributed in all the phyla (from archaea to chordates). Phylogenetic analysis of MGP gene revealed that it had an important role in the evolution of endogenous skeleton in contrast to exoskeleton of insects. Occurrence of these genes in evolution with conserved metal binding sites strengthens the role of ALAD and MGP genes in regulating heme biosynthesis and mineralization, respectively, in evolution and helps in better understanding of lead poisoning.

Urethral venous malformation: an unusual cause of recurrent post-coital gross haematuria in association with haematospermia

Three cases of recurrent post-coital haematuria are described. Extensive protracted investigations pinpointed urethral varicosities as the likely cause. All patients were successfully treated with diathermy fulguration.

Phase II trial comparing folinic acid, fluorouracil, and gemcitabine (FFG) and FOLFOX4 regimens with added bevacizumab (B) in metastatic colorectal cancer (mCRC)

e15098

Background: FOLFOX4 is a standard chemotherapy for mCRC. FFG has shown substantial activity in mCRC. This trial compared the safety and efficacy of FFG and FOLFOX4 regimens in patients (pts) with mCRC. B was added to each arm after FDA approval in 2004 as first-line treatment of mCRC. Methods: Pts with mCRC, chemonaïve except for adjuvant treatment, were randomized to two treatment arms: FFG given weekly for 6 weeks of an 8-week cycle; FOLFOX4 had a 2-week cycle. Pts in both groups received B at 5 mg/kg every 2 weeks. Treatment continued until disease progression. Planned enrollment was 150 pts. Primary endpoint was overall response rate (ORR); secondary endpoints included toxicity, overall survival (OS), and time to progression (TTP). Response was assessed by RECIST. Post-hoc analysis of disease control rate (DCR) was added. Results: Forty-two pts (18 pts given B) were randomized to each arm. Thirty-one cycles of FFG and 248 cycles of FOLFOX4 were delivered. FFG produced greater myelosuppression than FOLFOX4. Two cases each of MI and DVT were observed in the FOLFOX4(B) subgroup; one pt had DVT with FFG alone. The incidence of gastrointestinal hemorrhage was low and similar for FFG and FOLFOX4. Peripheral neuropathy was highest in the FOLFOX4(B) subgroup. ORR and DCR were significantly greater for FOLFOX4(B) than for FFG(B). Median TTP and OS were not statistically different for FFG and FOLFOX4 groups. The trial was stopped due to low enrollment; planned statistical power was not achieved. Conclusions: FFG and FOLFOX4 regimens were generally well tolerated, with greater neuropathy in FOLFOX4 and greater myelosuppression in FFG. ORR was greatest in the FOLFOX4(B) subgroup. TTP and OS results comparing FFG and FOLFOX4 groups were inconclusive due to low enrollment. Rapid changes in mCRC “standard of care” during this trial may have constrained pt accrual.

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