bluuebunny/crossref_metadata_2025 huggingface dataset:
Oral peptide delivery: in-vitro evaluation of thiolated alginate/poly(acrylic acid) microparticles
Authors: Greimel Alexander , Werle Martin , Bernkop-Schnürch Andreas
Published: September 2007

The purpose of this study was to develop an oral thiomer-based microparticulate delivery system for insulin by ionic gelation. The microparticulate matrix consisted of either poly(acrylic acid)-cysteine (PAA-Cys) and alginate-cysteine (Alg-Cys) or the corresponding unmodified polymers (PAA, Alg). Two different viscosities of alginates were provided for the study, low and medium. Three different types of microparticles were prepared via ionic gelation with calcium (Alg, AlgPAA and AlgPAA-Cys) and their different properties evaluated in-vitro (particle size and shape, drug loading and release profile, swelling and stability). The mean particle size of all formulations ranged from 400 to 600 μm, revealing the lowest for thiolated microparticles. SEM micrographs showed different morphological profiles for the three different types of microparticles. Encapsulation efficiency of insulin increased within the following rank order: Alg (15%) < AlgPAA (40%) < AlgPAA-Cys (65%). Alginate and AlgPAA microparticles displayed a burst release after 30 min, whereas the thiolated particles achieved a controlled release of insulin over 3 h. The swelling ratio was pH dependent: in simulated intestinal fluid microparticles exhibited a much higher water uptake compared with simulated gastric fluid. Due to the formation of intraparticulate disulfide bonds during the preparation process, thiolated particles revealed a higher stability. It was also observed that the viscosity of the two alginates used had no influence on the properties of the particles. According to these results AlgPAA-Cys microparticles obtained by ionic gelation and stabilized via disulfide bonds might be an alternative tool for the oral administration of therapeutic peptides.
Dermal delivery of selected hydrophilic drugs from elastic liposomes: effect of phospholipid formulation and surfactants
Authors: Ita Kevin B , Du Preez Jan , du Plessis Jeanetta , Lane Majella E , Hadgraft Jonathan
Published: September 2007

The effect of phospholipid formulation and choice of surfactant on skin permeation of selected hydrophilic drugs from elastic liposomes across human epidermal membrane has been studied. Sodium cholate and various concentrations of phosphatidylcholine were used for the preparation of liposomes namely hydrogenated phosphatidylcholine 90% (Phospholipon 90H), phosphatidylcholine 95% (Phospholipon 90G), phosphatidylcholine 78.6% (Phospholipon 80), and phosphatidylcholine 50% (Phosal PG). To investigate the effect of the surfactant, liposomes were prepared from 95% phosphatidylcholine (Phospholipon 90G) and various surfactants (sodium cholate, sodium deoxycholate, Span 20 (sorbitan monolaurate), Span 40 (sorbitan monopalmitate), Span 60 (sorbitan stearate) and Span 80 (sorbitan monooleate)). The vesicles were prepared by the conventional rotary evaporation technique. The film was hydrated with phosphate-buffered saline (10 mL) containing 9, 2 and 2.5 mg mL−1 of methotrexate, idoxuridine and aciclovir, respectively. All formulations contained 7% ethanol. Homogenously-sized liposomes were produced following extrusion through 100-nm polycarbonate filters using Lipex Extruder. Particle size was characterized by transmission electron microscopy. Vertical Franz diffusion cells were used for the study of drug delivery through human epidermal membrane. For the three drugs, the highest transcutaneous fluxes were from elastic liposomes containing 95% phosphatidylcholine. In general, a higher flux value was obtained for liposomes containing sodium cholate compared with sodium deoxycholate. For the liposomes containing sorbitan monoesters, there was no clearly defined trend between alkyl chain length and flux values. Overall, transcutaneous fluxes of liposomal preparations of hydrophilic drugs were comparable with those from saturated aqueous solutions (P > 0.05).
Anti-angiogenic, anti-inflammatory and anti-nociceptive activity of 4-hydroxybenzyl alcohol
Authors: Lim Eun-Ju , Jung Hyun-Joo , Park Eun-Hee , Kang Hyun-Jung
Published: September 2007

4-Hydroxybenzyl alcohol (HBA), one of the well-known phenolic compounds in diverse plants, displayed a significant inhibition in the chick chorioallantoic membrane (CAM) angiogenesis assay. HBA was shown to contain an anti-inflammatory activity in carrageenan-induced air pouch model in rats and acetic acid-induced permeability model in mice. Anti-nociceptive activity of HBA was also assessed using the acetic acid-induced writhing test in mice. HBA was able to suppress production of nitric oxide (NO) and expression of inducible nitric oxide synthase (iNOS) in lipopolysaccharide (LPS)-activated RAW264.7 macrophages. In the macrophages, the level of reactive oxygen species (ROS) was diminished by HBA. Taken together, HBA possesses anti-angiogenic, anti-inflammatory and anti-nociceptive activity possibly via its down-regulating activity on NO production, which may be partly responsible for the pharmacological efficacy of several folkloric medicines.
Effect of tetracycline on pancreas and liver function of adult male albino rats
Authors: Asha K K , Sankar T V , Nair P G Viswanathan
Published: September 2007

The effect of tetracycline, at two doses of 50 and 200 mg kg−1 daily, was studied on pancreatic and liver tissue function for 14 and 21 days in adult male albino rats. For pancreatic function the parameters studied were content of amylase and lipase in pancreas, serum amylase and lipase, serum glucose and faecal fat excretion. For liver function, liver specific enzymes in serum, namely alanine amino transaminase, aspartate amino transaminase and lactate dehydrogenase were estimated. In addition, total lipid, antiperoxidative enzymes and lipid peroxidation were measured in pancreas and liver. The content of amylase and lipase in pancreas showed a small but significant decrease in the rats given 50 mg kg−1 for 21 days and the decrease was much more significant in those receiving the 200 mg kg−1 dose. In pancreas free radical levels show a significant increase and reduced glutathione shows a substantial decrease at the 50 mg kg−1 level and a significant change in these parameters was observed at the 200 mg kg−1 dose. Antioxidant enzymes, superoxide dismutase, glutathione peroxidase, glutathione reductase and catalase, showed a small but significant decrease in the pancreas of the rats treated with 50 mg kg−1 tetracycline. A significant decrease in the antioxidant enzymes level was observed at the 200 mg kg−1 dose. In the liver, free radical levels and reduced glutathione were within the normal range at the 50 mg kg−1 level and significant changes were observed at 200 mg kg−1. The antioxidant status was unaffected in liver after treatment with tetracycline at the 50 mg kg−1 level and a significant decrease was observed at the higher dose. Our results reveal the safe nature of tetracycline with respect to the liver at the lower dose tested, whereas, both the higher and lower doses seem to have detrimental effect on the pancreas as revealed by the rise in free radical levels and decrease in the antioxidant enzyme levels.
Inhibitory mechanisms of gabapentin, an antiseizure drug, on platelet aggregation
Authors: Pan Chi-Feng , Shen Ming-Yi , Hsiao George , Chou Duen-Suey , Sheu Joen-Rong , Pan Chi-Feng , Wu Chih-Jen
Published: September 2007

Gabapentin (Neurontin) is an analogue of gamma-aminobutyric acid (GABA) that is effective against partial seizures. Gabapentin has been reported to modulate serotonin release from platelets, but the effects of gabapentin on platelet activation have not been explored. In this study, gabapentin concentration-dependently (60–240 μm) inhibited platelet aggregation in washed platelets stimulated by collagen (1 μg mL−1), ADP (20 μm) and arachidonic acid (60 μm). Gabapentin (120 and 240 μm) also concentration-dependently inhibited collagen (1 μg mL−1)-induced phospho-inositide breakdown, intracellular Ca2+ mobilization, thromboxane A2 formation, and p38 MAPK phosphorylation in human platelets. In conclusion, the most important findings of this study suggest that gabapentin inhibits platelet aggregation, at least in part, through the phospholipase C-inositol 1,4,5-trisphosphate-thromboxane A2-Ca2+ pathway. Thus, it is possible that gabapentin treatment, alone or in combination with other antiplatelet drugs, may induce or potentiate inhibition of platelet aggregation, which may affect haemostasis in-vivo.
Fructus Ligustrum lucidi inhibits inflammatory mediator release through inhibition of nuclear factor-κB in mouse peritoneal macrophages
Authors: An Hyo-Jin , Jeong Hyun-Ja , Um Jae-Young , Kim Hyung-Min , Park Yun-Jum , Park Rae-Kil , Kim Eun-Cheol , Na Ho-Jeong , Shin Tae-Yong , An Hyo-Jin , Hong Seung-Heon
Published: September 2007

Fructus Ligustrum lucidi (FLL) is a widely used herbal medicine for the treatment of a variety of pathologies. We have investigated the anti-inflammatory mechanism of FLL in mouse peritoneal macrophages. FLL exerted an anti-inflammatory action through inhibition of lipopolysaccharide (LPS)-induced tumour necrosis factor (TNF)-α production in mouse peritoneal macrophages. The maximal inhibition rate of TNF-α production by FLL (0.5 mg mL−1) was 60.88 + 0.30%. In the inflammatory process, nitric oxide (NO) and prostaglandin E2 (PGE2) increased in peritoneal macrophages. FLL decreased the protein level of NO and PGE2 in LPS-stimulated mouse peritoneal macrophages. In addition, FLL inhibited nuclear factor-κB activation and IκB-α degradation by the decrease in IκB-α phosphorylation. Our study suggested that FLL reduced inflammation via an important molecular mechanism, which might explain its beneficial effect in the regulation of inflammatory reactions.
Pomegranate peel extract prevents liver fibrosis in biliary-obstructed rats
Authors: Toklu Hale Z , Sehirli Ozer , Sener Goksel , Dumlu Melek U , Ercan Feriha , Gedik Nursal , Gökmen Vural
Published: September 2007

Punica granatum L. (pomegranate) is a widely used plant that has high nutritional value. The aim of this study was to assess the effect of chronic administration of pomegranate peel extract (PPE) on liver fibrosis induced by bile duct ligation (BDL) in rats. PPE (50 mg kg−1) or saline was administered orally for 28 days. Serum aspartate aminotransferase (AST), alanine aminotransferase (ALT) and lactate dehydrogenase (LDH) levels were determined to assess liver function and tissue damage. Proinflammatory cytokines (tumor necrosis factor-alpha and interleukin 1 beta) in the serum and anti-oxidant capacity (AOC) were measured in plasma samples. Samples of liver tissue were taken for measurement of hepatic malondialdehyde (MDA) and glutathione (GSH) levels, myeloperoxidase (MPO) activity and collagen content. Production of reactive oxidants was monitored by chemilumi-nescence assay. Serum AST, ALT, LDH and cytokines were elevated in the BDL group compared with the control group; this increase was significantly decreased by PPE treatment. Plasma AOC and hepatic GSH levels were significantly depressed by BDL but were increased back to control levels in the PPE-treated BDL group. Increases in tissue MDA levels and MPO activity due to BDL were reduced back to control levels by PPE treatment. Similarly, increased hepatic collagen content in the BDL rats was reduced to the level of the control group with PPE treatment. Thus, chronic PPE administration alleviated the BDL-induced oxidative injury of the liver and improved the hepatic structure and function. It therefore seems likely that PPE, with its antioxidant and antifibrotic properties, may be of potential therapeutic value in protecting the liver from fibrosis and oxidative injury due to biliary obstruction.
Using Clinical Classification Trees to Identify Individuals at Risk of STDs During Pregnancy
Authors: Kershaw Trace S. , Lewis Jessica , Westdahl Claire , Wang Yun F. , Rising Sharon Schindler , Massey Zohar , Ickovics Jeannette
Published: September 2007

CONTEXT:  Few studies have used classification tree analysis to produce empirically driven decision tools that identify subgroups of women at risk of STDs during pregnancy. Such tools can guide care, treatment and prevention efforts in clinical settings.

METHODS:  A sample of 647 women aged 14–25 attending two urban obstetrics and gynecology clinics in 2001–2004 were surveyed in their second and third trimesters. Baseline predictors at the individual, dyad, and family and community levels were used to develop a classification tree that differentiated subgroups of women by STD incidence at 35 weeks’ gestation. Logistic regression analyses were conducted to assess whether the classification tree groups or commonly used risk factors better predicted STD incidence.

RESULTS:  Nineteen percent of women had an incident STD during pregnancy. Classification tree analysis identified three subgroups with a high STD incidence (33–61%), one with a moderate incidence (16%) and three with a low incidence (6–11%). Women in subgroups with high STD incidence included those not living with the partner with whom they conceived and those who had a moderate or a high level of depression, a history of STDs and a low level of social support. A logistic regression model using groups defined by the classification tree analysis had better predictive ability than one using common demographic and sexual risk predictors.

CONCLUSION:  This classification tree identified risk factors not captured by traditional risk screenings, and could be used to guide STD treatment, care and prevention within the prenatal care setting.
Characteristics Associated with Emergency Contraception Use by Family Planning Patients: A Prospective Cohort Study
Authors: Whittaker Paul G. , Berger Matthew , Armstrong Kay A. , Felice Toni L. , Adams Janet
Published: September 2007

CONTEXT:  Little is known about how written family planning clinic policy regarding emergency contraception, as well as personal characteristics, behaviors and attitudes, may influence a woman to use emergency contraception.

METHODS:  Between June 2001 and July 2002, women attending publicly funded family planning clinics in Pennsylvania were enrolled in an 18‐month longitudinal study. Half attended clinics with a policy of offering emergency contraception in advance; the remainder had only emergent access to the drug. After providing baseline data, women completed monthly automated phone surveys about recent sexual activity, contraceptive use and attitudes toward pregnancy. Characteristics associated with recent use of emergency contraception were examined using multivariate logistic regression.

RESULTS:  Responses to 3,700 phone surveys from 729 women showed that 25% of those who attended clinics offering advance access used emergency contraception at least once during the study, compared with 8% who attended emergent access clinics. Women attending advance access clinics had significantly elevated odds of having used emergency contraception in the past month (odds ratio, 2.6). Other characteristics positively associated with the likelihood of recent emergency contraception use were familiarity with the drug, having a new sex partner and having unprotected sex at least once (2.0 each); negative feelings toward pregnancy (1.4); and using condoms as one’s main contraceptive method (1.8).

CONCLUSIONS:  In addition to discussing and offering advance emergency contraception, providers should further explore specific behaviors and attitudes associated with emergency contraception use.
Studies of Association of Variants Near the HHEX, CDKN2A/B, and IGF2BP2 Genes With Type 2 Diabetes and Impaired Insulin Release in 10,705 Danish Subjects
Authors: Grarup Niels , Rose Chrisian S. , Andersson Ehm A. , Andersen Gitte , Nielsen Arne L. , Albrechtsen Anders , Clausen Jesper O. , Rasmussen Signe S. , Jørgensen Torben , Sandbæk Annelli , Lauritzen Torsten , Schmitz Ole , Hansen Torben , Pedersen Oluf
Published: September 2007

OBJECTIVE— In the present study, we aimed to validate the type 2 diabetes susceptibility alleles identified in six recent genome-wide association studies in the HHEX/KIF11/IDE (rs1111875), CDKN2A/B (rs10811661), and IGF2BP2 (rs4402960) loci, as well as the intergenic rs9300039 variant. Furthermore, we aimed to characterize quantitative metabolic risk phenotypes of the four variants.

RESEARCH DESIGN AND METHODS— The variants were genotyped in the population-based Inter99 cohort (n = 5,970), the ADDITION Study (n = 1,626), a population-based sample of young healthy subjects (n = 377), and in additional type 2 diabetic case (n = 2,111) and glucose-tolerant (n = 521) subjects. The case-control studies involved a total of 4,089 type 2 diabetic patients and 5,043 glucose-tolerant control subjects.

RESULTS— We validated association of variants near HHEX/KIF11/IDE, CDKN2A/B, and IGF2BP2 with type 2 diabetes. Interestingly, in middle-aged people, the rs1111875 C-allele of HHEX/KIF11/IDE strongly associated with lower acute insulin response during an oral glucose tolerance test (P = 6 × 10−7). In addition, decreased insulin release following intravenous tolbutamide injection was observed in young healthy subjects (P = 0.02). Also, a reduced insulin release was observed for the CDKN2A/B rs10811661 T-allele after both oral and intravenous glucose challenges (P = 0.001 and P = 0.009, respectively).

CONCLUSIONS— We validate that variants in the proximity of the HHEX/KIF11/IDE, CDKN2A/B, and IFG2BP2 loci associate with type 2 diabetes. Importantly, variations within the HHEX/KIF11/IDE and CDKN2A/B loci confer impaired glucose- and tolbutamide-induced insulin release in middle-aged and young healthy subjects, suggesting a role for these variants in the pathogenesis of pancreatic β-cell dysfunction.
Early Management of Gunshot Injuries to the Face in Civilian Practice
Authors: Glapa Miriam , Kourie Jeffrey F. , Doll Dietrich , Degiannis Elias
Published: September 2007

Background

Gunshot injuries to the face in civilian practice are rarely reported. Potential complications in the Emergency Department can have catastrophic consequences, and inappropriate operative management of the facial soft and skeletal tissues are related to outcome.

Methods

A structured diagnostic and management approach is used in our Trauma Unit to deal with gunshot wounds to the face. A retrospective study of 55 patients who sustained gunshot injury to the face was conducted over a 6½‐year period. Demographic details, mechanism of injury, and mode of presentation and management were recorded. Mortality and morbidity data were collated.

Results

There were 51 male and 4 female patients. All injuries were caused by low‐velocity gunshots, except for one that was a shotgun injury. Overall, 28 of the 55 patients (50%) underwent orotracheal intubation on scene or in the resuscitation room, and 2 had cricothyroidotomy. In addition to the maxillofacial trauma, associated injuries were common. Forty patients underwent operation for maxillofacial trauma, 34 on the day of admission and the remaining 6 within 5 days of injury. Multiple operations over a 2‐week period were necessary for 18 of the 40 patients. Complications directly related to the gunshot injury to the face were very limited. Mortality was related to associated injuries.

Conclusions

Gunshot injury to the face in civilian violence is a “benign” condition as long as the Patient’s airway is kept patent and hemorrhage is controlled. Early operative intervention for repair of the soft and skeletal facial structures leads to satisfactory results. Mortality directly related to the facial trauma is uncommon.
Predictors of Cancer Worry in Unaffected Women from High Risk Breast Cancer Families: Risk Perception is not the Primary Issue
Authors: Price Melanie Anne , Butow Phyllis Noami , Lo Sing Kai , Wilson Judy ,   Kathleen Cuningham Consortium for Research into Familial Breast Cancer (kConFab) Psychosocial Group
Published: September 2007

Some women at increased familial risk of breast cancer experience elevated levels of cancer‐specific worry, which can possibly act as a barrier to screening, and may be a significant factor in decisions regarding risk‐reducing surgery. The aim of this study was to comprehensively examine predictors of cancer‐specific worry in high risk women and to test a model which proposes that perceived breast cancer risk mediates the impact of other factors on worry. 1,437 unaffected women from high risk breast cancer families completed questionnaires and interviews. Path analysis was used to test the model of potential predictors of cancer worry, including familial, personal and psychological variables, mediated via perceived cancer risk. Levels of cancer‐specific worry were generally low despite an average perceived risk of 50.3%. The goodness‐of‐fit of the proposed model was poor, explaining only 9% of the variance for perceived risk and 10% of the variance for cancer specific worry. An alternative model of a direct relationship between all of the predictor variables and cancer worry, explained 24% of the variation in cancer worry. General anxiety, perceived risk, the stressful impact of recent cancer related events, a relative risk greater than 10, being closer in age to the youngest breast cancer diagnosis in family, and knowledge of personal mutation status, all independently contributed to cancer worry. Addressing general affective responses, experiences of recent cancer related events, in addition to education about personal risk, should be considered in counselling women with elevated cancer worry. Risk perception appears to act independently of other factors in its formulation and impact on cancer worry. Further research on the way in which women come to perceive their risk is indicated.
The Use of Fast Methodologies (Kits) in Evaluating Deep‐Frying Oils
Authors: Osawa Cibele Cristina , Gonçalves Lireny Aparecida Guaraldo , Ragazzi Sidnei
Published: September 2007

Fried foods are frequently served by fast food establishments but the evaluation of the oil used is quite laborious, expensive, and requires a well‐structured laboratory with sophisticated equipment. Moreover, p‐anisidine, used as the reagent in the traditional test for monitoring the alkenal concentration of frying oils, is carcinogenic. The DiaMed F.A.T.S. kits for the determination of alkenal (AlkalSafe™ STD) and malonaldehyde (AldelSafe™ STD), equivalent to the p‐anisidine and TBA tests, respectively, are safe, fast and accurate, using compact equipment and generating fewer residues than the official methods. The results obtained using these kits were compared with those obtained using the official methods for determining alkenal (AOCS Cd 18b‐90) and malonaldehyde (AOCS Cd 19b‐90), in 20 samples collected from an institutional restaurant. Based on the least squares regression analysis, the AlkalSafe kit results were highly correlated with the p‐anisidine values (r = 0.74), but there was a lack of correlation between the results of the AldeSafe™ kit and the TBA test. Both kits were significantly more sensitive than the official methods, as revealed by the results of the Tukey test. Although the TBA values for the samples investigated were minimal, suggesting the inadequacy of the test for monitoring frying oils, the greater sensitivity of the kit makes it a relatively feasible option.
An improved protocol that induces human embryonic stem cells to differentiate into neural cells in vitro
Authors: Zhou Jun‐Mei , Chu Jian‐Xin , Chen Xue‐Jin
Published: September 2007

Human embryonic stem (ES) cells have the capacity for self‐renewal and are able to differentiate into any cell type. However, obtaining high‐efficient neural differentiation from human ES cells remains a challenge. This study describes an improved 4‐stage protocol to induce a human ES cell line derived from a Chinese population to differentiate into neural cells. At the first stage, embryonic bodies (EBs) were formed in a chemically‐defined neural inducing medium rather than in traditional serum or serum‐replacement medium. At the second stage, rosette‐like structures were formed. At the third stage, the rosette‐like structures were manually selected rather than enzymatically digested to form floating neurospheres. At the fourth stage, the neurospheres were further differentiated into neurons. The results show that, at the second stage, the rate of the formation of rosette‐like structures from EBs induced by noggin was 88 ± 6.32%, higher than that of retinoic acid 55 ± 5.27%. Immunocytochemistry staining was used to confirm the neural identity of the cells. These results show a major improvement in obtaining efficient neural differentiation of human ES cells.
Nitric oxide induced oxidative changes in erythrocyte membrane components
Authors: Brzeszczynska Joanna , Gwozdzinski Krzysztof
Published: September 2007

The effects of NO in its environment may vary considerably depending on various factors. This study shows oxidative mechanism of cellular membrane alterations, which is not associated with triggering of ONOOH generation but is induced by pure NO. Our investigation examined the influence of low concentration of NO (0.1; 0.2 mmol/l) on the qualitative changes of structure and dynamics of erythrocyte membrane. NO causes a statistically significant increase in membrane fluidity on different depths of lipid bilayer that is correlated with increase of lipids peroxidation. Statistically significant changes in the conformational state of cytoskeleton proteins were also detected. NO can be considered as a molecule responsible for determining rheological properties of erythrocytes membrane. Therefore, we propose that NO acts as pro‐oxidant molecule at concentrations for which membrane appeared to be the first target before it entered the cytosol.
Translocation of annexin B1 in response to the stimulation of PMA and ionomycin in cervical cancer cells
Authors: Huang Jing‐Jing , Yan Hong‐Li , Gao Yuan‐jian , Sun Shu‐Han , He Yan , Ding Fei‐Xiang , Mei Qian , Xue Geng
Published: September 2007

Annexin B1 is a novel member of the annexin superfamily which was isolated from a Cysticercus cellulosae cDNA library. To investigate the physiological roles of annexin B1, we firstly performed immunohistochemical analysis on frozen Cysticercus cellulosae sections and found that annexin B1 was present not only in the tegument of the bladder wall, but also in the host‐derived inflammatory layer; In addition, ELISA analysis revealed that annexin B1 could be detected in the cystic fluid of Cysticercus cellulosae and the sera of pigs with cysticercosis. These findings indicated that annexin B1 might be a secretary protein. We further constructed a pEGFP—annexin B1 plasmid and transfected it into SiHa cells. We found that GFP—annexin B1 was stimulated to translocate to the plasma membrane by phorbol 12‐myristate 13‐acetate (PMA). By contrast, it was induced to distribute at the plasma and nuclear membranes by treatment with calcium ionophore ionomycin. PMA increased annexin B1 membrane binding, which might facilitate exocytosis. Moreover, translocation of the protein to the plasma and nuclear membranes after stimulated by ionomycin, was predicted to be related to an additional function.
Dihydrorhodamine 123 is superior to 2,7‐dichlorodihydrofluorescein diacetate and dihydrorhodamine 6G in detecting intracellular hydrogen peroxide in tumor cells
Authors: Qin Yong , Lu Min , Gong Xingguo
Published: September 2007

Dihydrorhodamine 123 (DHR 123), 2,7‐dichlorodihydrofluorescein diacetate (DCFH‐DA), and dihydrorhodamine 6G (DHR 6G) were evaluated as probes for detecting cellular hydrogen peroxide levels in SPC‐A‐1 lung adenocarcinoma cells. Imaging techniques and fluorescence‐activated cell scan were used in the study of the probe responses. Obvious green fluorescence was established after a 25‐min exposure. After staining with MitoTracker Orange CM‐H2TMRos (a probe for mitochondria) and the abovementioned probes simultaneously, only the DHR 123 and DHR 6G groups exhibited legible green fluorescence in the mitochondrial regions. Furthermore, the DHR 6G group exhibited weaker fluorescence intensity. When 100 μM H2O2 was added to SPC‐A‐1 cells loaded with these probes, the intracellular fluorescence increased rapidly and significantly. Our results suggest that DHR 123 is superior for the instantaneous detection of cellular hydrogen peroxide in SPC‐A‐1 cells.
Mitochondrial localization of non‐histone protein HMGB1 during human endothelial cell–Toxoplasma gondii infection
Authors: Stumbo Ana Carolina , Cortez Erika , Rodrigues Carlos Alberto , Henriques Maria das Graças M.O. , Porto Luís Cristóvão , Barbosa Helene S. , Carvalho Laís
Published: September 2007

Toxoplasma gondii is an obligate intracellular pathogen, replicating only within a specialized membrane‐bounded cytoplasmic vacuole, the parasitophorous vacuole (PV), which interacts with host cell mitochondria. High mobility group box 1 (HMGB1), a known nuclear transcription factor, also may be involved in pathological conditions, whose function is to signal tissue damage. Using confocal microscopy, we have investigated the localization of HMGB1 and the mitochondria performance during interaction between human umbilical vein endothelial cells (HUVEC) and Toxoplasma. Immunofluorescence showed HMGB1 localization in HUVEC tubular mitochondria stained with Mito Tracker (MT). At 2 h post‐infection, MT labeled spherical structures scattered throughout the cytoplasm and HMGB1 were still present. After 24 h of infection, long and tubular structures were localized around PVs and were double labeled by MT and HMGB1, suggesting a structural reorganization of the mitochondria over a long period of infection. For the first time, these results show there is HMGB1 in HUVEC mitochondria and that this protein could be playing a part in mitochondrial DNA events which are important for fission and fusion processes reported here during HUVEC‐T. gondii infection.
Extensive mutagenesis experiments corroborate a structural model for the DNA deaminase domain of APOBEC3G
Authors: Chen Kuan-Ming , Martemyanova Natalia , Lu Yongjian , Shindo Keisuke , Matsuo Hiroshi , Harris Reuben S.
Published: September 2007

APOBEC3G is a single‐strand DNA cytosine deaminase capable of blocking retrovirus and retrotransposon replication. APOBEC3G has two conserved zinc‐coordinating motifs but only one is required for catalysis. Here, deletion analyses revealed that the minimal catalytic domain consists of residues 198‐384. Size exclusion assays indicated that this protein is monomeric. Many (31/69) alanine substitution derivatives of APOBEC3G198‐384 retained significant to full levels of activity. These data corroborated an APOBEC2‐based structural model for the catalytic domain of APOBEC3G indicating that most non‐essential residues are solvent accessible and most essential residues cluster within the protein core.
Hypoxic‐ischemic injury in neonatal brain: involvement of a novel neuronal molecule in neuronal cell death and potential target for neuroprotection
Authors: Hossain Mir Ahamed
Published: September 2007

Perinatal hypoxia‐ischemia (HI) is the most common cause of various neurological disabilities in children with high societal cost. Hypoxic‐ischemic brain damage is an evolving process and ample evidence suggests distinct difference between the immature and mature brain in the pathology and consequences of brain injury. Therefore, it is of utmost importance to better understand the mechanisms underlying the hypoxic‐ischemic injury in neonatal brain to devise effective therapeutic strategies. Nonetheless, the mechanism(s) involved in this pathology in the developing brain remain inadequately understood. Effective neuroprotective strategies will include either inhibition of the death effector pathways or induction of their regulatory and survival promoting cellular proteins. Neuronal pentraxins (NPs) define a family of novel proteins “long pentraxins” that are exclusively expressed in the central neurons, and are homologous to the C‐reactive and acute‐phase proteins in the immune system. NPs have been shown to be involved in the excitatory synaptic remodeling. We found that the neuronal protein ‘neuronal pentraxin 1′ (NP1) is induced in neonatal rat brain following HI, and NP1 induction preceded the time of actual tissue loss in brain. In demonstrating this we also found that NP1 gene silencing is neuroprotective against hypoxia‐induced neuronal death. This is the first evidence for a pathophysiological function of NP1 in central neurons. Our results suggest that NP1 is part of a death program triggered by HI. Most importantly, our findings of specific interactions of NP1 with the excitatory glutamate receptors AMPA GluR1 subunit and their co‐localization suggest a role for this novel neuronal protein NP1 in the excitotoxic cascade. Blockade of AMPA‐induced neuronal death following inhibition of NP1 expression further implicates a regulatory interaction between NP1 and AMPA glutamate receptors. Subsequent experiments using NP1 loss‐of‐function strategies, we have demonstrated specific requirements of NP1 induction in HI‐induced neuronal death. Together our findings clearly identify a novel role for NP1 in the coupling between HI and cerebral cell death. Thus, NP1 could be a new molecular target in the central neurons for preventing hypoxic‐ischemic neuronal death in developing brain. These very novel results could lead to more effective neuroprotective strategies against hypoxic‐ischemic brain injury in neonates.
Air Pollution: Impact on Maternal and Perinatal Health
Authors: Hackley Barbara , Feinstein Abigail , Dixon Jane
Published: September 2007

While air pollution levels have fallen in recent years, air quality in the United States is still poor and adversely affects the health of millions of persons. Because of physiologic changes in pregnancy, pregnant women and their fetuses are among the most vulnerable. This paper reviews the current state of our air quality, the impact that exposure to air pollution has on general health and the health of a pregnancy, and offers suggestions on how to minimize exposures.
Herbal and Other Complementary Medicine Use by Texas Midwives
Authors: Bayles Bryan P.
Published: September 2007

This cross‐sectional survey sought to document complementary and alternative medicine (CAM) use by Texas midwives, as well as to determine whether licensed direct‐entry midwives (LMs) and certified nurse‐midwives (CNMs) differed significantly in their patterns of use. All respondents (n = 69) indicated that they used, recommended, or referred their clients for at least one CAM therapy during the preceding year. Ninety percent (90%) of respondents used, recommended, or referred their clients for an herbal remedy (not including homeopathic tinctures). Herbal therapies were among the top three modalities recommended for 7 of 12 (58%) clinical indications. Herbs were the most salient CAM therapy used for cervical ripening (83%), followed closely by use for nausea, vomiting, and hyperemesis (80%), and labor induction (77%). Herbal therapies also constituted 50% or more of the CAM therapies used for the following indications: anemia/iron supplementation (70%), perineal healing (66%), and anxiety/stress/fatigue (50%). LM respondents used, recommended, or referred their clients for a greater number of herbal therapies compared to CNMs. While several of the CAM modalities used or recommended by Texas midwives show potential for clinical benefit, few have been studied sufficiently to determine their efficacy or safety during pregnancy.
Influence of added mass on anomalous high rise velocity of light particles in cellular flow field: A note on the paper by Maxey (1987)
Authors: Marchioli Cristian , Fantoni Marco , Soldati Alfredo
Published: September 2007

In this Brief Communication, we examine in detail the motion of light particles—or dense gas bubbles—rising under gravity in a cellular flow. We follow the methodology of Maxey [Phys. Fluids 30, 1915 (1987)], and we examine a range of parameters not fully discussed in the past, corresponding to particles lighter and yet more inertial than the surrounding fluid if the added mass effect is considered. We observe a nonmonotonic behavior of the particle rise velocity, which exhibits a maximum for density of the particles only slightly smaller than the density of the fluid. The maximum value of the average rise velocity corresponding to the “optimum” density is several times (more than 40) higher than those obtained for small density changes around the optimum. The occurrence of this maximum is due to the combined effects of particle inertia and fluid added mass, which segregate the rising particles into specific, fast pathlines where the local fluid velocity adds to the particle gravitational velocity. A plot covering particle rise velocity for this range—not covered by the analysis of Maxey—is provided.
Surface acoustic wave depth profiling of a functionally graded material
Authors: Goossens Jozefien , Leclaire Philippe , Xu Xiaodong , Glorieux Christ , Martinez Loic , Sola Antonella , Siligardi Cristina , Cannillo Valeria , Van der Donck Tom , Celis Jean-Pierre
Published: September 2007

The potential and limitations of Rayleigh wave spectroscopy to characterize the elastic depth profile of heterogeneous functional gradient materials are investigated by comparing simulations of the surface acoustic wave dispersion curves of different profile-spectrum pairs. This inverse problem is shown to be quite ill posed. The method is then applied to extract information on the depth structure of a glass-ceramic (alumina) functionally graded material from experimental data. The surface acoustic wave analysis suggests the presence of a uniform coating region consisting of a mixture of Al2O3 and glass, with a sharp transition between the coating and the substrate. This is confirmed by scanning electron microscope with energy dispersive x-ray analysis.
Size-quantized oscillations of the electron mobility limited by the optical and confined acoustic phonons in the nanoscale heterostructures
Authors: Pokatilov E. P. , Nika D. L. , Askerov A. S. , Balandin A. A.
Published: September 2007

The authors theoretically investigated the electron mobility in the nanometer thickness AlN∕GaN∕AlN heterostructures limited by the polar optical and confined acoustic phonons. The proposed model accurately takes into account dispersion of the optical and acoustic phonons in such heterostructures as well as inelasticity of the electron scattering on both optical and acoustic phonons. It has been shown that the intersubband electronic transitions play an important role in limiting the electron mobility when the energy separation between one of the size-quantized excited electron subbands and the Fermi energy becomes comparable to the optical or confined acoustic phonon energy. The latter results in the nonmonotonic oscillatory dependence of the electron mobility on the thickness of the GaN conduction channel layer. The predicted effect is observable at room temperature and over a wide range of carrier densities. The described mechanism can be used for fine tuning the confined electron and phonon states in the nanoscale heterostructures made of different material systems in order to achieve performance enhancement of the nanoscale electronic devices.
Effect of acceptor (Mg) concentration on the electrical resistance at room and high (200°C) temperatures of acceptor (Mg)-doped BaTiO3 ceramics
Authors: Yoon Seok-Hyun , Hong Min-Hee , Hong Jeong-Oh , Kim Young-Tae , Hur Kang-Heon
Published: September 2007

The behaviors of the electrical resistance at room and high (200°C) temperatures of acceptor (Mg)-doped BaTiO3 ceramics with the increase of acceptor concentration were investigated. A series of coarse-grained specimens with different acceptor concentrations that were sintered at various oxygen partial pressures was prepared. The critical acceptor concentrations, beyond which the room temperature resistance increases abruptly, were experimentally evaluated and they were found to increase with a decrease in oxygen partial pressure during sintering. Each defect and electron concentrations at sintering and room temperature as a function of acceptor concentration were theoretically calculated. The results calculated could explain the experimentally observed behavior of the resistance versus acceptor concentration. The high (200°C) temperature resistances under high electric field showed resistance degradation critically depending on acceptor concentration in the very small concentration range below ∼0.1mol%, which occurred easily with the increase of acceptor concentration. It was explained that such behavior was caused by the variation of potential barrier of grain boundaries for the migration of oxygen vacancies as a function of acceptor concentration.
Poloidal beta and internal inductance measurement on HT-7 superconducting tokamak
Authors: Shen B. , Sun Y. W. , Wan B. N. , Qian J. P.
Published: September 2007

Poloidal beta βθ and internal inductance li measurements are very important for tokamak operation. Much more plasma parameters can be inferred from the two parameters, such as the plasma energy confinement time, the plasma toroidal current profile, and magnetohydrodynamics instability. Using diamagnetic and compensation loop, combining with poloidal magnetic probe array signals, poloidal beta βθ and internal inductance li are measured. In this article, the measurement system and arithmetic are introduced. Different experimental results are given in different plasma discharges on HT-7 superconducting tokamak.
Imaging three-dimensional light propagation through periodic nanohole arrays using scanning aperture microscopy
Authors: Chowdhury Mustafa H. , Catchmark Jeffrey M. , Lakowicz Joseph R.
Published: September 2007

The authors introduce a technique for three-dimensional (3D) imaging of the light transmitted through periodic nanoapertures using a scanning probe to perform optical sectioning microscopy. For a 4×4 nanohole array, the transmitted light displays intensity modulations along the propagation axis, with the maximum intensity occurring at 450μm above the surface. The propagating fields show low divergence, suggesting a beaming effect induced by the array. At distances within 25μm from the surface, they observe subwavelength confinement of light propagating from the individual nanoholes. Hence, this technique can potentially be used to map the 3D distribution of propagating light, with high spatial resolution.
Large low field magnetoresistance in ultrathin nanocrystalline magnetite Fe3O4 films at room temperature
Authors: Lu Z. L. , Xu M. X. , Zou W. Q. , Wang S. , Liu X. C. , Lin Y. B. , Xu J. P. , Lu Z. H. , Wang J. F. , Lv L. Y. , Zhang F. M. , Du Y. W.
Published: September 2007

Ultrathin (15nm) Fe3O4 nanocrystalline films with (111) spinel texture have been prepared by rapid annealing of amorphous ion oxide films. Large low field magnetoresistance (LFMR), with the values of about −6.3% at 300K and −10% at 200K under a field of 0.5T, has been observed in the films. The LFMR is mainly attributed to the boundary tunneling of high spin-polarized electrons in Fe3O4 grains of the films and nearly follows a simple relationship between MR and polarization for intergranular tunneling. The fabricating method here seems to be a good approach to prepare high quality Fe3O4 nanocrystalline films with a large LFMR at room temperature.
A novel non-overlapping bi-clustering algorithm for network generation using living cell array data
Authors: Yang E. , Foteinou P.T. , King K.R. , Yarmush M.L. , Androulakis I.P.
Published: September 2007

Motivation: The living cell array quantifies the contribution of activated transcription factors upon the expression levels of their target genes. The direct manipulation of the regulatory mechanisms offers enormous possibilities for deciphering the machinery that activates and controls gene expression. We propose a novel bi-clustering algorithm for generating non-overlapping clusters of reporter genes and conditions and demonstrate how this information can be interpreted in order to assist in the construction of transcription factor interaction networks.

Contact:  Yannis@rci.rutgers.edu
N-Myristoylation Regulates the SnRK1 Pathway inArabidopsis
Authors: Pierre Michèle , Traverso José A. , Boisson Bertrand , Domenichini Séverine , Bouchez David , Giglione Carmela , Meinnel Thierry
Published: September 2007

Cotranslational and posttranslational modifications are increasingly recognized as important in the regulation of numerous essential cellular functions. N-myristoylation is a lipid modification ensuring the proper function and intracellular trafficking of proteins involved in many signaling pathways. Arabidopsis thaliana, like human, has two tightly regulated N-myristoyltransferase (NMT) genes, NMT1 and NMT2. Characterization of knockout mutants showed that NMT1 was strictly required for plant viability, whereas NMT2 accelerated flowering. NMT1 impairment induced extremely severe defects in the shoot apical meristem during embryonic development, causing growth arrest after germination. A transgenic plant line with an inducible NMT1 gene demonstrated that NMT1 expression had further effects at later stages. NMT2 did not compensate for NMT1 in the nmt1-1 mutant, but NMT2 overexpression resulted in shoot and root meristem abnormalities. Various data from complementation experiments in the nmt1-1 background, using either yeast or human NMTs, demonstrated a functional link between the developmental arrest of nmt1-1 mutants and the myristoylation state of an extremely small set of protein targets. We show here that protein N-myristoylation is systematically associated with shoot meristem development and that SnRK1 (for SNF1-related kinase) is one of its essential primary targets.
Healthcare libraries in Saudi Arabia: analysis and recommendations
Authors: Khudair Ahmad , Bawden David
Published: September 2007

Purpose

The paper aims to gain a detailed understanding of the current health library/information environment in Saudi Arabia, to identify problems, issues, and areas for improvement, to make recommendations for improvement, and to instantiate these in models and prototypes.

Design/methodology/approach

A mixed method empirical approach is used in 11 health libraries, including literature survey, institutional profiling, questionnaire, interviews, non‐participant observation, and examination of documents. A model for supporting change management in Saudi health libraries is proposed, and a prototype for a Saudi Health Information Network is developed.

Findings

The healthcare libraries are well‐used, and appreciated by their users, and the staff are generally satisfied with their work. Problems and issues are identified: use of information communication technologies and digital resources; lack of proactive information services; education, training and continuing professional development for health library work; limited strategic planning and policy for these services. Recommendations are made for improvements.

Research limitations/implications

The empirical research is limited to health sciences libraries in Riyadh, the capital of Saudi Arabia. The prototype health information network has not been evaluated by users.

Practical implications

Recommendations are made to enable the government of Saudi Arabia and its various agencies to support improvements in the existing health sciences libraries and information provision.

Originality/value

This is a detailed study of the health library environment in Saudi Arabia, illustrating factors typical of the situation in many other countries. The paper outlines a novel organisational change model and prototype national health information network.