bluuebunny/crossref_metadata_2025 huggingface dataset:
Palliative care for older people – exploring the views of doctors and nurses from different fields in Germany
Authors: Brueckner Torben , Schumacher Martin , Schneider Nils
Published: June 2009

Background

Providing appropriate palliative care for older people is a major task for health care systems worldwide, and up to now it has also been one of the most neglected. Focusing on the German health care system, we sought to explore the attitudes of health professionals regarding their understanding of palliative care for older patients and its implementation.

Methods

In a qualitative study design, focus groups were established consisting of general practitioners, geriatricians, palliative care physicians, palliative care nurses and general nurses (a total of 29 participants). The group discussions were recorded, transcribed, coded and analysed using the methodological approach of Qualitative Description.

Results

Deficiencies in teamwork and conflicting role definitions between doctors and nurses and between family practitioners and medical specialists were found to be central problems affecting the provision of appropriate palliative care for older people. It was emphasized that there are great advantages to family doctors playing a leading role, as they usually have the longest contacts to the patients. However, the professional qualifications of family doctors were to some extent criticized. The general practitioners for their part criticized the increasing specialization on the field of palliative care. All groups complained that the German compensation system gives insufficient consideration to the time-consuming care of older patients, and about excessive bureaucracy.

Conclusion

General practitioners are the central health professionals in the delivery of palliative care for older people. They should however be encouraged to involve specialized services such as palliative care teams where necessary. With the German health care reform of 2007, a legal framework has been created that allows for this. As far as its realization is concerned, it must be ensured that the spotlight remains on the needs of the patients and not on policy conflicts and rivalries between health care professionals. Older people might particularly benefit if "talking" medicine and time-consuming care were properly catered for, financially and organizationally, in the health care system.
Hospital-associated methicillin-resistant Staphylococcus aureus (HA-MRSA) in Italy
Authors: Campanile Floriana , Bongiorno Dafne , Borbone Sonia , Stefani Stefania
Published: June 2009

The aim of our study was to trace the dynamic changes of hospital-associated methicillin-resistant Staphylococcus aureus (HA-MRSA) lineages in Italy, comparing the genotypic backgrounds of contemporary isolates over a period of 17 years, with those of a sample of early MRSA strains from 1980.

In total, 301 non-repetitive MRSA clinical isolates, recovered from 19 Italian hospitals between 1990 and 2007 were selected and analyzed for their antibiotic resistance, typed by PFGE and SCCmec, grouped into clonal-types and further characterized using Multi Locus Sequence Typing (MLST). A sample of fifteen early MRSA strains from 1980 was also used for comparison.

The most interesting feature was the recent increase of ST228-MRSA-I (formerly the Italian clone; PFGE E) over the period 2000–2007 (57%), when compared to the period 1990–1999 (29%), and its stability to date, associated with a decrease of the highly epidemic ST247-MRSA-IA (formerly the Iberian clone; PFGE A), (23% from 1990 to 1999, 6% from 2000 to 2007). ST1-MRSA-I (1 out of 2 strains carrying ccr A2B2), ST8-MRSA-I (4 strains), ST15-MRSA-I (1 out of 4 carrying ccr A2B2) and ST30-MRSA-I (2 out of 5 carrying no ccr AB-types and ccr C) were the predominant earliest STs among the MRSA strains in 1980.

A temporal shift in the susceptibility levels to glycopeptides was observed: strains with vancomycin MIC of ≥ 2 mg/L increased from 19.4% to 35.5%.

In conclusion, we describe the alternation of MRSA clones that occurred in hospitals from 1990 to 2007 and the increase of the glycopeptide MIC levels, reflecting a worldwide trend. We document the detection of ST1, ST8, ST15 and ST30 in the 1980 isolates; we hypothesize their possible latency and their appearance as the current CA-MRSA clones.
Effects of cIAP-1, cIAP-2 and XIAP triple knockdown on prostate cancer cell susceptibility to apoptosis, cell survival and proliferation
Authors: Gill Catherine , Dowling Catherine , O'Neill Amanda J , Watson R William G
Published: June 2009

Background

Manipulating apoptotic resistance represents an important strategy for the treatment of hormone refractory prostate cancer. We hypothesised that the Inhibitor of Apoptosis (IAP) Proteins may be mediating this resistance and knockdown of cIAP-1, cIAP-2 and XIAP would increase sensitivity to apoptosis.

Methods

cIAP-1, cIAP-2 and XIAP where knocked down either individually or in combination using siRNA in androgen independent prostate cancer PC-3 cells as confirmed by real-time PCR and western blotting. Cells were then treated with TRAIL, Etoposide, or Tunicamycin, and apoptosis assessed by PI DNA staining. Apoptosis was confirmed with Annexin V labelling and measurement of PARP cleavage, and was inhibited using the pan-caspase inhibitor, zVAD.fmk. Clonogenic assays and assessment of ID-1 expression by western blotting were used to measure recovery and proliferation.

Results

PC-3 are resistant to TRAIL induced apoptosis and have elevated expression of cIAP-1, cIAP-2 and XIAP. Combined knockdown sensitised PC-3 to TRAIL induced apoptosis, but not to Etoposide or Tunicmycin, with corresponding increases in caspase activity and PARP cleavage which was inhibited by ZVAD.fmk. Triple knock down decreased proliferation which was confirmed by decreased ID-1 expression.

Conclusion

Simultaneous knock down of the IAPs not only sensitised the PC-3 to TRAIL but also inhibited their proliferation rates and clonogenic survival. The inability to alter sensitivity to other triggers of apoptosis suggests that this effect is specific for death receptor pathways and knock down might facilitate immune-surveillance mechanisms to counter cancer progression and, in combination with therapeutic approaches using TRAIL, could represent an important treatment strategy.
Chronic crude garlic-feeding modified adult male rat testicular markers: mechanisms of action
Authors: Hammami Imen , Amara Souheila , Benahmed Mohamed , El May Michèle V , Mauduit Claire
Published: June 2009

Background

Garlic or Allium sativum (As) shows therapeutic effects such as reduction of blood pressure or hypercholesterolemia but side-effects on reproductive functions remain poorly investigated. Because of garlic's chemical complexity, the processing methods and yield in preparations differ in efficacy and safety. In this context, we clarify the mechanisms of action of crushed crude garlic on testicular markers.

Methods

During one month of treatment, 24 male rats were fed 5%, 10% and 15% crude garlic.

Results

We showed that crude garlic-feeding induced apoptosis in testicular germ cells (spermatocytes and spermatids). This cell death process was characterized by increased levels of active CASP3 but not CASP6. Expression of the caspase inhibitors BIRC3 and BIRC2 was increased at all doses of As while expression of XIAP and BIRC5 was unchanged. Moreover, expression of the IAP inhibitor DIABLO was increased at doses 10% and 15% of As. The germ cell death process induced by As might be related to a decrease in testosterone production because of the reduced expression of steroidogenic enzymes (Star, Cyp11a, Hsd3b5 and Hsd17b). Evaluation of Sertoli markers showed that TUBB3 and GSTA2 expression was unchanged. In contrast, AMH, RHOX5 and CDKN1B expression was decreased while GATA4 expression was increased.

Conclusion

In summary, we showed that feeding with crude garlic inhibited Leydig steroidogenic enzyme expression and Sertoli cell markers. These alterations might induce apoptosis in testicular germ cells.
Inference of gene pathways using mixture Bayesian networks
Authors: Ko Younhee , Zhai ChengXiang , Rodriguez-Zas Sandra
Published: June 2009

Background

Inference of gene networks typically relies on measurements across a wide range of conditions or treatments. Although one network structure is predicted, the relationship between genes could vary across conditions. A comprehensive approach to infer general and condition-dependent gene networks was evaluated. This approach integrated Bayesian network and Gaussian mixture models to describe continuous microarray gene expression measurements, and three gene networks were predicted.

Results

The first reconstructions of a circadian rhythm pathway in honey bees and an adherens junction pathway in mouse embryos were obtained. In addition, general and condition-specific gene relationships, some unexpected, were detected in these two pathways and in a yeast cell-cycle pathway. The mixture Bayesian network approach identified all (honey bee circadian rhythm and mouse adherens junction pathways) or the vast majority (yeast cell-cycle pathway) of the gene relationships reported in empirical studies. Findings across the three pathways and data sets indicate that the mixture Bayesian network approach is well-suited to infer gene pathways based on microarray data. Furthermore, the interpretation of model estimates provided a broader understanding of the relationships between genes. The mixture models offered a comprehensive description of the relationships among genes in complex biological processes or across a wide range of conditions. The mixture parameter estimates and corresponding odds that the gene network inferred for a sample pertained to each mixture component allowed the uncovering of both general and condition-dependent gene relationships and patterns of expression.

Conclusion

This study demonstrated the two main benefits of learning gene pathways using mixture Bayesian networks. First, the identification of the optimal number of mixture components supported by the data offered a robust approach to infer gene relationships and estimate gene expression profiles. Second, the classification of conditions and observations into groups that support particular mixture components helped to uncover both gene relationships that are unique or common across conditions. Results from the application of mixture Bayesian networks substantially augmented the understanding of gene networks and demonstrated the added-value of this methodology to infer gene networks.
IGF-I and IGFBP-3 and the risk of lung cancer: A meta-analysis based on nested case-control studies
Authors: Chen Bo , Liu Shan , Xu Wei , Wang Xueli , Zhao Weihong , Wu Jianqing
Published: June 2009

Background

Lung cancer is the leading cause of death from cancer worldwide. Conventional studies mainly think that insulin-like growth factor-I (IGF-I) and IGF-binding protein-3 (IGFBP-3) may promote and inhibit tumor growth, respectively. However, there are many different results about their function in some recent epidemiological studies. To evaluate the relationship between circulating serum levels of IGF-I, IGFBP-3 and lung cancer, a systematic review and meta-analysis of the published data was performed.

Methods

Literatures searched on PubMed and Embase databases were enrolled in the Meta-analysis. The Meta-analysis of all eligible studies was applied with Stata 10.0 software, and the pooled odds ratio(OR) and weighted mean difference (WMD) value were obtained. The Q test, Egger's test and Begg's funnel plot were used to evaluate the heterogeneity and publication bias between the studies.

Results

There are no statistically significant heterogeneity and publication bias between the studies. For IGF- I, the pooled OR and WMD were 0.87(95%CI: 0.60~1.13,) and -3.04(95%CI: -7.10~1.02, P = 0.14), respectively. For IGFBP-3, the pooled OR and WMD were 0.68(95%CI: 0.48~0.88,) and -112.28(95%CI: -165.88~-58.68, P < 0.0001), respectively.

Conclusion

The association between circulating IGF- I levels and the risk of lung cancer were not statistically significant; IGFBP-3, acts as a tumor suppressor and has a inverse correlation with the risk of lung cancer.
Factors associated with septic shock and mortality in generalized peritonitis: comparison between community-acquired and postoperative peritonitis
Authors: Riché Florence C , Dray Xavier , Laisné Marie-Josèphe , Matéo Joaquim , Raskine Laurent , Sanson-Le Pors Marie-José , Payen Didier , Valleur Patrice , Cholley Bernard P
Published: June 2009

Introduction

The risk factors associated with poor outcome in generalized peritonitis are still debated. Our aim was to analyze clinical and bacteriological factors associated with the occurrence of shock and mortality in patients with secondary generalized peritonitis.

Methods

This was a prospective observational study involving 180 consecutive patients with secondary generalized peritonitis (community-acquired and postoperative) at a single center. We recorded peri-operative occurrence of septic shock and 30-day survival rate and analyzed their associations with patients characteristics (age, gender, SAPS II, liver cirrhosis, cancer, origin of peritonitis), and microbiological/mycological data (peritoneal fluid, blood cultures).

Results

Frequency of septic shock was 41% and overall mortality rate was 19% in our cohort. Patients with septic shock had a mortality rate of 35%, versus 8% for patients without shock. Septic shock occurrence and mortality rate were not different between community-acquired and postoperative peritonitis. Age over 65, two or more microorganisms, or anaerobes in peritoneal fluid culture were independent risk factors of shock. In the subgroup of peritonitis with septic shock, biliary origin was independently associated with increased mortality. In addition, intraperitoneal yeasts and Enterococci were associated with septic shock in community-acquired peritonitis. Yeasts in the peritoneal fluid of postoperative peritonitis were also an independent risk factor of death in patients with septic shock.

Conclusions

Unlike previous studies, we observed no difference in incidence of shock and prognosis between community-acquired and postoperative peritonitis. Our findings support the deleterious role of Enterococcus species and yeasts in peritoneal fluid, reinforcing the need for prospective trials evaluating systematic treatment against these microorganisms in patients with secondary peritonitis.
Insulin-Stimulated Translocation of Glucose Transporter (GLUT) 12 Parallels That of GLUT4 in Normal Muscle
Authors: Stuart Charles A. , Howell Mary E. A. , Zhang Yi , Yin Deling
Published: June 2009

Context: GLUT4 is the predominant glucose transporter isoform expressed in fat and muscle. In GLUT4 null mice, insulin-stimulated glucose uptake into muscle was diminished but not eliminated, suggesting that another insulin-sensitive system was present.

Objective: This study was intended to determine whether insulin caused GLUT12 translocation in muscle.

Design: Six normal volunteers had muscle biopsies before and after euglycemic insulin infusions.

Setting: Infusions and biopsies were performed in an outpatient clinic.

Participants: Subjects were nonobese, young adults with no family history of diabetes.

Main Outcome Measures: GLUT12, GLUT4, and GLUT1 proteins were quantified in muscle biopsy fractions. Cultured myoblasts were used to determine whether GLUT12 translocation was phosphatidyl inositol-3 kinase (PI3-K)-dependent.

Intervention. Insulin was infused at 40 mU/m2 · min for 3 h.

Results: In human muscle, insulin caused a shift of a portion of GLUT12 from intracellular low-density microsomes to the plasma membrane (PM) fraction (17% in PM at baseline, 38% in PM after insulin). Insulin increased GLUT4 in PM from 13 to 42%. GLUT1 was predominantly in the PM fractions at baseline and did not change significantly after insulin. L6 myoblasts in culture also expressed and translocated GLUT12 in response to insulin, but inhibiting PI3-K prevented the translocation of GLUT12 and GLUT4.

Conclusions: Insulin causes GLUT12 to translocate from an intracellular location to the plasma membrane in normal human skeletal muscle. Translocation of GLUT12 in cultured myoblasts was dependent on activation of PI3-K. GLUT12 may have evolutionarily preceded GLUT4 and now provides redundancy to the dominant GLUT4 system in muscle.

Insulin induces sequestered GLUT12 to move to the muscle cell surface.
Aging Attenuates the Pituitary Response to Gonadotropin-Releasing Hormone
Authors: Shaw Natalie D. , Srouji Serene S. , Histed Stephanie N. , McCurnin Kristin E. , Hall Janet E.
Published: June 2009

Context: Complex changes in GnRH secretion occur with aging in women, but little is known about the effect of aging on the pituitary per se.

Objective: The aim of the study was to determine whether pituitary responsiveness to GnRH is attenuated with aging.

Design and Setting: A GnRH antagonist and graded doses of GnRH were used to isolate pituitary responsiveness in Clinical Research Center studies at an academic medical center.

Subjects: Subjects were healthy postmenopausal women (PMW) aged 48–57 yr (n = 10) or 70–77 yr (n= 9).

Interventions: A suppressive dose of the NAL-GLU GnRH antagonist (150 μg/kg sc) was administered and was followed by GnRH doses of 25, 75, 250, or 750 ng/kg iv every 4 h.

Results: The LH response to GnRH was attenuated with aging (P = 0.05) with an interaction between age and dose (P = 0.01) such that the LH amplitude was less in older PMW at the higher doses (250 ng/kg, 50 ± 9 vs. 29 ± 4.9 IU/liter, for young and old PMW, respectively, P = 0.02; and 750 ng/kg, 97.7 ± 11 vs. 70.2 ± 9.3 IU/liter, P = 0.002), but not the lower doses of GnRH. The FSH response to GnRH was also attenuated with aging in PMW (P = 0.005).

Conclusions: In studies that isolated the pituitary from endogenous GnRH stimulation, aging attenuated the LH and FSH responses to exogenous GnRH in PMW. These studies indicate that the pituitary plays a role in the decline in gonadotropin levels with aging, further supporting the potential contribution of age-associated changes in both hypothalamic and pituitary function to reproductive senescence.

Studies using a hypothalamic clamp to isolate the pituitary from endogenous GnRH input in postmenopausal women demonstrate that the LH and FSH responses to GnRH are diminished with aging.
Improving glyburide solubility and dissolution by complexation with hydroxybutenyl-β-cyclodextrin
Authors: Klein Sandra , Wempe Michael F , Zoeller Thomas , Buchanan Norma L , Lambert Juanelle L , Ramsey Michael G , Edgar Kevin J , Buchanan Charles M
Published: June 2009

Objectives

Glyburide, an important drug for type 2 diabetes, has extremely poor aqueous solubility and resulting low bioavailability. This study describes the ability of hydroxybutenyl-β-cyclodextrin (HBenBCD) to form complexes with glyburide, with enhanced solubility and dissolution rate in vitro.

Method

Glyburide and glyburide-HBenBCD were evaluated in various test media known to simulate human gastrointestinal conditions in the fasted and fed states, respectively.

Key findings

At ∼14 wt% drug load, in the presence of HBenBCD, an almost 400-fold increase in glyburide aqueous solubility was observed. In the presence of HBenBCD, glyburide solubility was also significantly improved in all physiologically relevant test media. Subsequent dissolution experiments confirmed the solubility study results; the dissolution rate and total amount of drug released were significantly increased.

Conclusions

Complexation with HBenBCD may be an effective way to increase the bioavailability of glyburide.
The role of molecular physicochemical properties and apolipoproteins in association of drugs with triglyceride-rich lipoproteins: in-silico prediction of uptake by chylomicrons
Authors: Gershkovich Pavel , Fanous Joseph , Qadri Bashir , Yacovan Avihai , Amselem Shimon , Hoffman Amnon
Published: June 2009

Objectives

The uptake of drugs by chylomicrons is a key element in both intestinal lymphatic transport and postprandial alterations in the disposition profile of lipophilic drugs. The aim of this article was to elucidate the factors that affect this phenomenon.

Methods

The degree of association of 22 model lipophilic molecules with rat chylomicrons was assessed and correlated in silico with calculated physicochemical properties. The in-silico model was then validated using an external set of molecules. The uptake by chylomicrons was also compared to the association with a marketed artificial emulsion.

Key findings

The most important physicochemical property that affects the affinity to chylomicrons was found to be LogD7.4; however, a multiparameter model was required to describe properly the uptake process. The in-silico model (R2Y = 0.91, R2X = 0.91 and Q2 = 0.82) that was created using a combination of eight molecular descriptors enabled successful prediction of the affinity of the external set of molecules to chylomicrons. The association with the artificial emulsion was statistically different from the uptake by chylomicrons for four (out of nine) molecules.

Conclusions

The association of drugs with chylomicrons is a complex process, which involves the lipophilic core as well as surface apoproteins. The in-silico model based on multiple physicochemical properties of the drugs is able to predict successfully the degree of association with chylomicrons.
Concentration-dependent plasma protein binding of the novel dipeptidyl peptidase 4 inhibitor BI 1356 due to saturable binding to its target in plasma of mice, rats and humans
Authors: Fuchs Holger , Tillement Jean-Paul , Urien Saik , Greischel Andreas , Roth Willy
Published: June 2009

Objectives

The purpose of this study was to characterise the plasma protein binding of BI 1356.

Methods

BI 1356 (proposed trade name ONDERO) is a novel dipeptidyl peptidase 4 (DPP-4) inhibitor, which is under clinical development for the treatment of type 2 diabetes. DPP-4 is expressed in various tissues but soluble DPP-4 is also present in plasma. Therefore, binding to soluble DPP-4 may influence the pharmacokinetics of BI 1356. Plasma protein binding of BI 1356 was determined in vitro for wild type mice and rats and the results compared with those for DPP-4 knockout mice and DPP-4 deficient Fischer rats. In addition, protein binding of BI 1356 was examined in plasma from healthy human volunteers and renal excretion of the compound in the DPP-4 knockout mice was compared with that occurring in wild type mice.

Key findings

The results showed that BI 1356 exhibited a prominent concentration-dependent plasma protein binding due to a saturable high affinity binding to the DPP-4 target in plasma. Differences in renal excretion of BI 1356 between DPP-4 knockout mice and wild type mice suggested that saturable binding of BI 1356 to DPP-4 in the body also influenced elimination.

Conclusions

High affinity, but readily saturable binding of BI 1356 to its target DPP-4 accounted primarily for the concentration-dependent plasma protein binding at therapeutic plasma concentrations of BI 1356.
Human phenylalanine monooxygenase and thioether metabolism
Authors: Boonyapiwat Boontarika , Panaretou Barry , Forbes Ben , Mitchell Stephen C , Steventon Glyn B
Published: June 2009

Objectives

The substrate specificity of wild-type human phenylalanine monooxygenase (wt-hPAH) has been investigated with respect to the mucoactive drug, S-carboxymethyl-L-cysteine and its thioether metabolites. The ability of wt-hPAH to metabolise other S-substituted cysteines was also examined.

Methods

Direct assays of PAH activity were by HPLC with fluorescence detection; indirect assays involved following disappearance of the cofactor by UV spectroscopy.

Key findings

wt-hPAH catalysed the S-oxygenation of S-carboxymethyl-L-cysteine, its decarboxylated metabolite, S-methyl-L-cysteine, and both their corresponding N-acetylated forms. However, thiodiglycolic acid was not a substrate. The enzyme profiles for both phenylalanine and S-carboxymethyl-L-cysteine showed allosteric kinetics at low substrate concentrations, with Hill constants of 2.0 and 1.9, respectively, for the substrate-activated wt-hPAH. At higher concentrations, both compounds followed Michaelis–Menten kinetics, with non-competitive substrate inhibition profiles. The thioether compounds, S-ethyl-L-cysteine, S-propyl-L-cysteine and S-butyl-L-cysteine were all found to be substrates for phenylalanine monooxygenase.

Conclusions

Phenylalanine monooxygenase may play a wider role outside intermediary metabolism in the biotransformation of dietary-derived substituted cysteines and other exogenous thioether compounds.
Andrographolide inhibits growth of acute promyelocytic leukaemia cells by inducing retinoic acid receptor-independent cell differentiation and apoptosis
Authors: Manikam Shiamala T , Stanslas Johnson
Published: June 2009

Objectives

The growth inhibiting potential of andrographolide was evaluated in three acute promyelocytic leukaemia cell line models (HL-60, NB4 and all-trans retinoic acid (ATRA)-resistant NB4-R2).

Methods

In elucidating the mechanisms of growth inhibition, a special emphasis was placed on assessing the induction of differentiation and apoptosis by andrographolide in the primary acute promyelocytic leukaemia NB4 cells.

Key findings

The compound was 2- and 3-fold more active in inhibiting the growth of HL-60 and NB4-R2 cells compared with NB4 cells, respectively. At IC50 (concentration at which growth of 50% of the cells (compared with medium only treated control cells) is inhibited; 4.5 μM) the compound exhibited strong cell-differentiating activity in NB4 cells, similar to ATRA (IC50 1.5 μM). In the presence of a pure retinoic acid receptor antagonist AGN193109, the growth inhibition of NB4 cells by ATRA was reversed, whereas the activity of andrographolide was not affected. This clearly suggested that andrographolide's cell differentiating activity to induce growth inhibition of NB4 cells most likely occurred via a retinoic acid receptor-independent pathway. At higher concentration (2 × IC50), andrographolide was an efficient inducer of apoptosis in NB4 cells.

Conclusions

Taken together, these results suggest andrographolide and its derivatives, apparently with a novel cell differentiating mechanism and with ability to induce apoptosis, might be beneficial in the treatment of primary and ATRA-resistant acute promyelocytic leukaemia.
Increased sensitivity to diltiazem hypotensive effect in an experimental model of high-renin hypertension
Authors: Bertera Facundo M , Mayer Marcos A , Opezzo Javier A W , Taira Carlos A , Höcht Christian
Published: June 2009

Objectives

The aim of this work was to evaluate the pharmacokinetic–pharmacodynamic properties of diltiazem in an experimental model of high-renin hypertension, such as the aortic coarctated (ACo) rat, to further characterize the responsiveness of this model to calcium channel blockers.

Methods

A ‘shunt’ microdialysis probe was inserted in a carotid artery of anaesthetized ACo and control sham-operated (SO) rats for simultaneous determination of diltiazem plasma concentrations and their effects on mean arterial pressure and heart rate after the intravenous application of 3 and 6 mg/kg of the drug. Correlation between plasma levels and cardiovascular effects was established by fitting the data to a modified Emax model.

Key findings

Volume of distribution was greater in ACo than in SO rats. Diltiazem plasma clearance (Cl) was significantly greater in ACo rats than in normotensive SO rats after administration of diltiazem (6 mg/kg). Moreover, Cl increased with dose in ACo but not in SO rats. No differences were observed in the maximal bradycardic effect comparing both experimental groups, and sensitivity (S0) to diltiazem chronotropic effect was similar comparing SO and ACo rats. Differences were not found in the maximal response of the hypotensive effect comparing SO and ACo rats, but the S0 to diltiazem hypotensive effect was greater in ACo rats than in SO rats.

Conclusions

ACo induced profound changes in diltiazem pharmacokinetic behaviour. In addition, our results suggested an increased sensitivity to diltiazem blood pressure lowering effect in experimental renovascular hypertension with high-renin levels.
Triclisia sacleuxii(Pierre) Diels (Menispermaceae), a potential source of acetylcholinesterase inhibitors
Authors: Murebwayire Sengabo , Ingkaninan Kornkanok , Changwijit Kanokwan , Frédérich Michel , Duez Pierre
Published: June 2009

Objectives

To search for compounds possibly useful for the treatment of Alzheimer's disease.

Methods

Alkaloid fractions from the roots, stems and leaves of Triclisia sacleuxii (Menispermaceae) and pure bisbenzylisoquinoline alkaloids isolated from the roots (phaeanthine, N-methylapateline, 1,2-dehydroapateline and gasabiimine) were assessed for acetylcholin-esterase inhibitory activity.

Key findings

All extracts and compounds tested inhibited acetylcholinesterase to varying degrees; the leaf tertiary alkaloid fractions and the root quaternary alkaloid fractions exhibited the strongest inhibitory potential (90% at 0.1 mg/ml). The leaf tertiary alkaloid fraction was selected for further analysis (the quaternary alkaloids, which are too polar for absorption and brain distribution, were presumed to be clinically uninteresting). TLC bioautography using Ellman's reagent allowed the detection of acetylcholinesterase inhibitors and the isolation of the major active constituent, which was identified as lindoldhamine, a one-bridged bisbenzylisoquinoline alkaloid. Lindoldhamine displayed high acetylcholinesterase inhibitory activity with a 50% inhibition concentration in the micromolar range.

Conclusions

All T. sacleuxii alkaloid fractions tested exhibited anti-acetylcholinesterase activity; isolated bisbenzylisoquinoline alkaloids showed weak-to-high inhibition depending on their structural features. Structure modification could provide interesting derivatives with enhanced anti-acetylcholinesterase activity.
Effect of natsudaidain isolated fromCitrusplants on TNF-α and cyclooxygenase-2 expression in RBL-2H3 cells
Authors: Matsui Takuya , Ito Chihiro , Itoigawa Masataka , Okada Tadashi , Furukawa Hiroshi
Published: June 2009

Objectives

Flavonoids inhibit the activity of chemical mediators released from mast cells. Our aim was to investigate the effects of natsudaidain, a polymethoxyflavone isolated from Citrus plants, on mast cells.

Methods

We investigated the inhibitory effects of natsudaidain, which is a polymethoxy-flavone isolated from Citrus plants, on histamine release, tumour necrosis factor-α production and cyclooxygenase-2 expression in Ca ionophore-stimulated rat basophilic leukemia cells (A23187-stimulated RBL-2H3 cells) by spectrofluorometric, ELISA and immunoblotting methods.

Key findings

The percent of histamine release from A23187-stimulated RBL-2H3 cells pretreated with natsudaidain at 5, 25 and 50 μM was not changed as compared with non-treated A23187-stimulated cells. At 100 and 200 μM, natsudaidain pretreatment resulted in slightly reduced histamine release (% histamine release, 89.8 ± 3.5% and 71.5 ± 5.6% at 100 and 200 μM). Thus, natsudaidain hardly affects histamine release from RBL-2H3 cells, except at high concentrations. On the other hand, natsudaidain dose-dependently inhibited tumour necrosis factor-α protein and mRNA levels in A23187-stimulated RBL-2H3 cells; a concentration of 6.8 μM was required for a 50% reduction. In addition, all concentrations of this compound that we tested also inhibited cyclooxygenase-2 protein expression. The mRNA levels of cyclooxygenase-2 in A23187-stimulated RBL-2H3 cells treated with natsudaidain were also markedly decreased. The phosphorylated-p38 MAPK protein levels in A23187-stimulated RBL-2H3 cells treated with natsudaidain were lower than in the non-treated cells.

Conclusions

These findings suggest that natsudaidain inhibits tumour necrosis factor-α and cyclooxygenase-2 production by suppressing p38 MAPK phosphorylation but not p65 NFKB phosphorylation, and that natsudaidain might alleviate inflammatory diseases.
Inhibitory effect of quercetin on rat trachea contractility in vitro
Authors: Capasso Raffaele , Aviello Gabriella , Romano Barbara , Atorino Giuseppina , Pagano Ester , Borrelli Francesca
Published: June 2009

Objectives

The effect of quercetin, a naturally occurring flavonoid traditionally used to treat airway diseases such as bronchial asthma, on the contractile response elicited by electrical field stimulation or carbachol in rat isolated trachea was investigated.

Methods

Isolated tracheal tissue was subjected to contractions by an electrical field stimulation of 5 Hz for 30 s, 400 mA, and the responses in the presence of cumulative concentrations of quercetin (10−6−3 × 10−4 M) were observed. The effect of quercetin was also evaluated after administration of phentolamine plus propranolol (to block α- and β-adrenergic receptors), NG-nitro-L-arginine methyl ester (to block nitric oxide synthesis), capsaicin (to desensitise sensory C fibres), α-chymotrypsin (a proteolytic enzyme that rapidly degrades vasoactive intestinal peptide), SR140333 and SR48968 (tackykinin NK1 and NK2 receptor antagonists, respectively).

Key findings

Quercetin produced a concentration-dependent inhibition of contractions induced by both carbachol and electrical field stimulation. However, quercetin was more active in inhibiting the contractions produced by electrical field stimulation than those induced by carbachol, suggesting a presynaptic site of action (in addition to a postsynaptic effect, as revealed by the inhibitory action of quercetin on carbachol-induced contractions). The inhibitory effect of quercetin on contractions induced by electrical field stimulation was unaffected by phentolamine plus propranolol, SR 140333 and SR 48968, capsaicin treatment or by the proteolytic enzyme α-chymotrypsin. In contrast, the nitric oxide synthase inhibitor NG-nitro-L-arginine methyl ester significantly reduced the inhibitory effect of quercetin on contractions induced by electrical field stimulation.

Conclusions

Quercetin inhibits rat tracheal contractility through a presynaptic (involving nitric oxide) and a postsynaptic site of action.
Fish skin as a model membrane: structure and characteristics
Authors: Konrádsdóttir Fífa , Loftsson Thorsteinn , Sigfússon Sigurdur Dadi
Published: June 2009

Objectives

Synthetic and cell-based membranes are frequently used during drug formulation development for the assessment of drug availability. However, most of the currently used membranes do not mimic mucosal membranes well, especially the aqueous mucous layer of the membranes. In this study we evaluated catfish (Anarichas lupus L) skin as a model membrane.

Method

Permeation of hydrocortisone, lidocaine hydrochloride, benzocaine, diethyl-stilbestrol, naproxen, picric acid and sodium nitrate through skin from a freshly caught catfish was determined in Franz diffusion cells.

Key findings

Both lipophilic and hydrophilic molecules permeate through catfish skin via hydrated channels or aqueous pores. No correlation was observed between the octanol/water partition coefficient of the permeating molecules and their permeability coefficient through the skin. Permeation through catfish skin was found to be diffusion controlled.

Conclusions

The results suggest that permeation through the fish skin proceeds via a diffusion-controlled process, a process that is similar to drug permeation through the aqueous mucous layer of a mucosal membrane. In addition, the fish skin, with its collagen matrix structure, appears to possess similar properties to the eye sclera.
Pharmacokinetic comparison of puerarin after oral administration of Jiawei-Xiaoyao-San to healthy volunteers and patients with functional dyspepsia: influence of disease state
Authors: Qin Feng , Huang Xi , Zhang Hong-Min , Ren Ping
Published: June 2009

Objectives

An investigation has been designed and conducted to compare the pharmaco-kinetics of puerarin after oral administration of Jiawei-Xiaoyao-San to healthy volunteers and to patients with functional dyspepsia.

Methods

Quantification of puerarin in serum was achieved using a simple and rapid HPLC method for pharmacokinetic study.

Key findings

After oral administration of decoctions of Jiawei-Xiaoyao-San to healthy volunteers and patients with functional dyspepsia, puerarin was absorbed and reached a maximum concentration of 56.47 ± 15.60 and 29.40 ± 8.89 ng/ml at 51.00 ± 8.22 and 50.00 ± 12.25 min, respectively. Compared with the value of AUC0–360 (5.55 ± 1.47 μg/ml min) in healthy volunteers, a smaller value of AUC0–360 (3.35 ± 1.17 μg/ml min) was observed in patients with functional dyspepsia.

Conclusions

There were statistically significant differences in the pharmacokinetic parameters of puerarin including the values for Cmax, AUC0–360, Cl/F and MRT0–360 between healthy volunteers and patients with functional dyspepsia. The pharmacokinetic parameters showed that functional dyspepsia reduced the absorption of puerarin after oral administration of Jiawei-Xiaoyao-San.
Stability of oleuropein in the human proximal gut
Authors: Markopoulos Constantinos , Vertzoni Maria , Agalias Apostolos , Magiatis Prokopios , Reppas Christos
Published: June 2009

Objectives

We aimed to assess the intralumenal stability of oleuropein in human gastric and small intestinal contents. We additionally aimed to assess the stability characteristics of oleuropein in media simulating the intralumenal conditions.

Methods

The intralumenal stability of oleuropein was assessed in aspirates from the stomach and the upper small intestine of healthy volunteers collected under both fasted and fed state conditions and in media simulating the intralumenal environment.

Key findings

Oleuropein degraded in aspirates collected in the fasted state. When the initial concentration was about 50 μg/ml (close to expected intragastric concentration after single dose of commercially available products of oleuropein) the mean zero-order half-life of oleuropein in aspirates collected from the fasted small intestine was estimated to be 3.14 ± 0.08 h at 37°C (i.e. after oral administration in the fasted state, a substantial fraction of oleuropein degrades before reaching the intestinal mucosa). In contrast, oleuropein was stable in aspirates collected from the fed stomach; in small intestinal contents aspirated in the fed state the estimated zero-order degradation half-life was at least 12 h.

Conclusions

These data suggest that oleuropein should not have substantial intralumenal stability problems when administered in the fed state. Data collected in media simulating the intragastric and intraintestinal environment suggest that pH affects the stability of oleuropein only at low pH values (of about 2). At higher pHs degradation characteristics are at least partly affected by the presence of other scavengers of reactive oxygen species in the medium.
Metabolism of captopril carboxyl ester derivatives for percutaneous absorption
Authors: Gullick Darren R , Ingram Matthew J , Pugh W John , Cox Paul A , Gard Paul , Smart John D , Moss Gary P
Published: June 2009

Objectives

To determine the metabolism of captopril n-carboxyl derivatives and how this may impact on their use as transdermal prodrugs. The pharmacological activity of the ester derivatives was also characterised in order to compare the angiotensin converting enzyme inhibitory potency of the derivatives compared with the parent drug, captopril.

Methods

The metabolism rates of the ester derivatives were determined in vitro (using porcine liver esterase and porcine ear skin) and in silico (using molecular modelling to investigate the potential to predict metabolism).

Key findings

Relatively slow pseudo first-order metabolism of the prodrugs was observed, with the ethyl ester displaying the highest rate of metabolism. A strong relationship was established between in-vitro methods, while in-silico methods support the use of in-vitro methods and highlight the potential of in-silico techniques to predict metabolism. All the prodrugs behaved as angiotensin converting enzyme inhibitors, with the methyl ester displaying optimum inhibition.

Conclusions

In-vitro porcine liver esterase metabolism rates inform in-vitro skin rates well, and in-silico interaction energies relate well to both. Thus, in-silico methods may be developed that include interaction energies to predict metabolism rates.
Pectin/Kollicoat SR30D isolated films for colonic delivery [I]: a comparison of normal and colitis-induced models to assess the efficiency of microbially triggered drug delivery
Authors: Wei He , Li-Fang Fan , Yong-Zhen Chang , Bai Xiang , Qing Du , Min Bai , Feng Wang , Min Qing , De-Ying Cao
Published: June 2009

Objectives

The purpose of the study was to evaluate digestion of pectin/Kollicoat SR30D free films for colonic delivery in vitro and in vivo.

Methods

Free films containing different ratios of pectin to Kollicoat SR30D were prepared by casting/solvent evaporation method. An in-vitro comparison of swelling, degradation and permeability of the free films was carried out in simulated colon fluids containing caecal contents from normal rats with colitis induced by 2,4,6-trinitrobenzene sulfonic acid (TNBS) or oxazolone. A comparative in-vivo evaluation of degradation was also conducted in normal and colitis-induced model rats.

Key findings

The pectin within the mixed films was susceptible to rat colonic bacterial enzymes. The extent of digestion correlated with the amount of pectin present within the film. In vitro, the swelling index, drug permeability and extent of film digestion in simulated colon fluids with caecal contents obtained from normal rats were higher than from TNBS- or oxazolone-induced model rats, whereas in-vivo degradation was similar in the three groups of rats. The pectin/Kollicoat SR30D free films were completely degraded in the colitis-induced rats.

Conclusions

Pectic/Kollicoat SR30D films may be useful as coatings to target delivery of drugs to the colon.
Coumarins permeability in Caco-2 cell model
Authors: Galkin Anna , Fallarero Adyary , Vuorela Pia M
Published: June 2009

Objectives

The presence of coumarins in human diet, their multiple pharma***ćological properties and occurrence in various herbal remedies represent significant reasons to explore their membrane permeability, as a first event contributing to coumarins oral bioavailability. Thus, we evaluated the permeability and cytotoxicity of 18 coumarins, with different substitution patterns involving OH, OCH3 and CH3 groups.

Methods

A modified Caco-2 permeability model was used, in which the permeability test is performed with a robotic workstation and cells are grown on 96-well plates for 7 days.

Key findings

All studied coumarins were highly permeable, with calculated Papp values that varied within 4.1 times 10−5 to 2.1 times 10−4 in apical to basolateral studies and within 1.8 times 10−5 to 7.0 times 10−5 in basolateral to apical studies. The efflux ratio remained in all cases below 1. It was demonstrated that the type and position of substituents contributed more to the permeability than the number of substituents.

Conclusions

The results allowed us to predict that these coumarins are well absorbed in the gut lumen and efflux is not limiting the absorption. Five coumarins had an influence on the mitochondrial function of Caco-2 cells (1 < 80%, 4 > 120%), according to the WST-1 cytotoxicity test, but this does not seem to affect the permeability of the compounds.
Oxidative stress, nitric oxide and prostaglandin E2 levels in the gastrointestinal tract of aging rats
Authors: Mármol Frederic , Sánchez Juan , López Diego , Martínez Nuria , Mitjavila Maria Teresa , Puig-Parellada Pere
Published: June 2009

Objectives

To evaluate the presence of oxidative stress and alterations in the levels of two cytoprotective agents, prostaglandin E2 and nitric oxide, in the gastrointestinal tract of aging rats.

Methods

The production of superoxide anion, lipid peroxides, levels of superoxide dismutase and catalase, and production of prostaglandin E2 and nitric oxide in the stomach and duodenum of rats were determined at 1.5, 3, 12, 18 and 24 months of age.

Key findings

Oxidative stress was present in the stomach of the old rats (24 months), whereas prostaglandin E2 and nitric oxide production remained stable at 18 and 24 months. In the duodenum, no oxidative stress was observed at 24 months, but at 18 months, an increase in superoxide anion levels was detected. Prostaglandin E2 remained constant in the aged rats but nitric oxide decreased significantly at 24 months.

Conclusions

The absence of macroscopic gastric injury throughout the gastrointestinal tract indicates that the oxidative stress in the stomach and the significant decrease of nitric oxide in the duodenum in the old rats are not sufficient to disrupt the mucosal defence network. The results support the notion that the disruption of the mucosal network is essentially regulated by the cytoprotective agents prostaglandin E2 and nitric oxide, and that injury appears only when both substances are concurrently reduced.
Animal studies supporting the inhibition of mast cell activation byEriobotrya japonicaseed extract
Authors: Onogawa Masahide , Sun Guangchen , Takuma Daisuke , Hamada Atsuhide , Yokota Junko , Yoshioka Saburo , Kusunose Masahiko , Miyamura Mitsuhiko , Kyotani Shojiro , Nishioka Yutaka
Published: June 2009

Objectives

The potent antioxidant activity of Eriobotrya japonica seed extract (ESE) and its usefulness in the prevention and treatment of various disorders has been reported previously. Its antioxidant activity associated with β-sitosterol and polyphenols contained in the extract was also validated. In this study, anti-allergic activity of Eriobotrya japonica seed extract was investigated.

Methods

The inhibition of histamine release-mediated type 1 allergy by Eriobotrya japonica seed extract was used as an index.

Key findings

The administration of this extract inhibited histamine release from rat mast cells, suggesting its usefulness in allergic disease treatment. In an experiment using a guineapig allergic rhinitis model, this extract reduced the frequency of sneezing and nose-scratching.

Conclusions

These results suggest that Eriobotrya japonica seed extract may contribute to the relief of allergic disease-related symptoms.
Nonprimed and DYRK1A-primed GSK3β-phosphorylation sites on MAP1B regulate microtubule dynamics in growing axons
Authors: Scales Timothy M. E. , Lin Shen , Kraus Michaela , Goold Robert G. , Gordon-Weeks Phillip R.
Published: June 2009

MAP1B is a developmentally regulated microtubule-associated phosphoprotein that regulates microtubule dynamics in growing axons and growth cones. We used mass spectrometry to map 28 phosphorylation sites on MAP1B, and selected for further study a putative primed GSK3β site and compared it with two nonprimed GSK3β sites that we had previously characterised. We raised a panel of phosphospecific antibodies to these sites on MAP1B and used it to assess the distribution of phosphorylated MAP1B in the developing nervous system. This showed that the nonprimed sites are restricted to growing axons, whereas the primed sites are also expressed in the neuronal cell body. To identify kinases phosphorylating MAP1B, we added kinase inhibitors to cultured embryonic cortical neurons and monitored MAP1B phosphorylation with our panel of phosphospecific antibodies. These experiments identified dual-specificity tyrosine-phosphorylation-regulated kinase (DYRK1A) as the kinase that primes sites of GSK3β phosphorylation in MAP1B, and we confirmed this by knocking down DYRK1A in cultured embryonic cortical neurons by using shRNA. DYRK1A knockdown compromised neuritogenesis and was associated with alterations in microtubule stability. These experiments demonstrate that MAP1B has DYRK1A-primed and nonprimed GSK3β sites that are involved in the regulation of microtubule stability in growing axons.