Search PubMed⌕ Search

Biomedical subjects

Bin Lu

Publications and source records attributed to Bin Lu.

At least 37 records · Page 2Linked to original sources
PubMed2006

Novel colon-specific microspheres with highly dispersed hydroxycamptothecin cores: their preparation, release behavior, and therapeutic efficiency against colonic cancer.

To increase therapeutic efficiency of hydroxycamptothecin (HCPT) against colonic cancer and decrease its side-effects, highly dispersed HCPT was first incorporated in fast release microspheres. HCPT in the microspheres showed a solubility two times larger, and its cumulative release rate for 24 h in simulated colonic juice 140 times higher than that of free HCPT. The microspheres were then coated with a layer of Eudragit S100 by air suspension spray-drying method with a self-designed device to obtain colon-specific microspheres (HCPT-CSMS). The mean particle size of the microspheres was 200 microm before coating and 230 microm after coating. The in vitro cumulative release results for HCPT-CSMS in simulated gastric juice for 2 h, in simulated enteric juice for 4 h, and in simulated colonic juice for 18 h showed that over 60% of total HCPT released in simulated colonic juice in the initial 5 h. Animal tests with per os (po) administration showed that free HCPT was mainly absorbed in stomach and small intestine, while the HCPT in HCPT-CSMS was mainly delivered and absorbed in colon. po administration of HCPT-CSMS to nude mice with colonic cancer showed a cancer inhibition rate of 61.4% compared to 39.8% for free HCPT.

Animals↗
PubMed2006

An evaluation of the International Diabetes Federation definition of metabolic syndrome in Chinese patients older than 30 years and diagnosed with type 2 diabetes mellitus.

The objective of the study was to determine the most accurate metabolic syndrome (MS) definition among the definitions proposed by the International Diabetes Federation (IDF), the Third Report of the National Cholesterol Education Program Expert Panel on Detection, Evaluation, and Treatment of High Blood Cholesterol in Adults (Adult Treatment Panel III [ATPIII]), and the World Health Organization (WHO) and to evaluate the cutoff point of waist circumference using the IDF definition for optimally defining MS in the Chinese population. One thousand thirty-nine Chinese patients older than 30 years and diagnosed with type 2 diabetes mellitus were investigated by randomized cluster sampling in the Shanghai downtown, and 1008 patients were analyzed in this study. Body mass measurements, resting blood pressure, fasting blood measures, and carotid atherosclerotic measurements including common carotid artery intima-media thickness (IMT) and carotid plaque were investigated. The IDF definition was compared with the other 2 definitions, and the carotid atherosclerosis was evaluated among the patients according to these definitions. (1) The MS prevalence was 50.0%, 55.7%, and 70.0% under the IDF, ATPIII, and WHO definitions, respectively. (2) The percentage of all the participants categorized as either having or not having the MS was 69.9% (under the IDF and ATPIII definitions) and 70.2% (under the IDF and WHO definitions). (3) Common carotid artery IMT of patients with MS determined by the IDF definition was thicker than those determined by the WHO and ATPIII definitions, and the percentage of carotid plaque of patients with MS determined by the IDF definition was greater than those determined by the WHO and ATPIII definitions. (4) When the cutoff point of waist circumference in men determined by the IDF definition was modified from 90 to 85 cm, common carotid artery IMT of the emerging male patients with MS was thicker than that of the male patients with MS determined by the original IDF definition. In conclusion, the prevalence of MS was 50.0%, 55.7%, and 70.0% under the IDF, ATPIII, and WHO definitions, respectively. The preferable IDF definition served as a better predictor of cardiovascular disease risk in the Chinese patients diagnosed with type 2 diabetes mellitus compared with the ATPIII and WHO definitions. The modified cutoff point of waist circumference in men under the IDF definition specific for the Chinese population (from 90 to 85 cm) might be more suitable for predicting atherosclerosis.

Aged↗
PubMed2006

Acute drug-induced vascular injury in beagle dogs: pathology and correlating genomic expression.

Acute vascular injury that leads to vascular inflammation is a common finding in the preclinical toxicity testing of drugs in rats and dogs. However, the relevance of this finding for risk to humans is unclear. Concern about the safety of these drugs is heightened by the current lack of noninvasive clinical methods to predict the onset of vascular damage in animals or humans. Determining the relevance of this poorly understood preclinical outcome for humans requires a better understanding of the molecular mechanisms of injury in addition to the development of sensitive and specific leading biomarkers for the clinical diagnosis of acute vascular damage. Most molecular research on this toxicity has been performed in rats, but recent development of canine gene expression microarrays makes transcriptomic studies now possible in the dog. In this study, we investigated the molecular mechanisms of drug-induced vascular injury in dogs using gene arrays. After treating Beagles with toxic doses of CI-947, an adenosine receptor agonist, we profiled gene expression in the coronary arteries and correlated those changes with histopathology at 16 and 24 hours after dosing. The results demonstrated that pathobiological processes such as stimulation of the innate immune response, increased extracellular matrix turnover and oxidative stress were active at times of very early injury.

Acute Disease↗
PubMed2006

Human embryonic stem cell-derived cells rescue visual function in dystrophic RCS rats.

Embryonic stem cells promise to provide a well-characterized and reproducible source of replacement tissue for human clinical studies. An early potential application of this technology is the use of retinal pigment epithelium (RPE) for the treatment of retinal degenerative diseases such as macular degeneration. Here we show the reproducible generation of RPE (67 passageable cultures established from 18 different hES cell lines); batches of RPE derived from NIH-approved hES cells (H9) were tested and shown capable of extensive photoreceptor rescue in an animal model of retinal disease, the Royal College of Surgeons (RCS) rat, in which photoreceptor loss is caused by a defect in the adjacent retinal pigment epithelium. Improvement in visual performance was 100% over untreated controls (spatial acuity was approximately 70% that of normal nondystrophic rats) without evidence of untoward pathology. The use of somatic cell nuclear transfer (SCNT) and/or the creation of banks of reduced complexity human leucocyte antigen (HLA) hES-RPE lines could minimize or eliminate the need for immunosuppressive drugs and/or immunomodulatory protocols.

Animals↗
PubMed2006

Expression and significance of nerve growth factor receptor p75 in rats' cathartic colonic wall.

OBJECTIVE: To investigate the expression of nerve growth factor receptor p75 in a normal and cathartic colon and its significance in the formation of the cathartic colon in rats. METHODS: Sixty Sprague-Dawley rats were equally divided into normal control group, rhubarb group and phenolphthalein group. A model of the cathartic colon was constructed by gastric infusion with rhubarb or phenolphthalein in rats. The first dose of rhubarb and phenolphthalein was both 200 mg/kg/d and was increased by 200 mg/kg/d with each passing day. The last dose of rhubarb and phenolphthalein was 3200 mg/kg/d and 4200 mg/kg/d, respectively. The transit function of colon was measured by the Chinese ink expulsion test; the p75 in colon wall was determined by the immunohistochemical method. RESULTS: The transit speed was much slower in the cathartic colon group than that in the control group. The imprinted Chinese ink length and the ratio of imprinted length/total colon length in the rhubarb-induced cathartic colon was significantly shorter than that of the control group (77.38 +/- 8.42 vs 94.25 +/- 7.07 cm, P < 0.01). Those in the phenolphthalein-induced group (83.38 +/- 9.75 cm) were also significantly shorter than those of the control group but to a lesser degree (P < 0.05). p75 was abundantly expressed in the submucosal nerve plexus and weakly expressed in the myenteric plexus. The expression of p75 was much higher in the rhubarb-induced group. The expression was strongly positive in the submucosal nerve plexus, significantly higher than that in the controls (P < 0.01). In the myenteric plexus, p75 was also highly expressed (P < 0.05). In the case of the phenolphthalein-induced group, the expression of p75 was positive in the submucosal nerve plexus but was positive in the myenteric plexus of three rats only. The remaining rats were negative or weakly positive. This was not significantly different from that of the control group. CONCLUSIONS: The abnormal expression of p75 in cathartic colon probably has some effect on the degeneration or apoptosis of neuronal cells in the enteric nerve plexus, with a subsequent pathological change of the enteric nervous system, and thus leads to abnormalities in colonic dynamics. The kind of lesion is probably associated with long-term use of irritative cathartics.

Animals↗
PubMed2006

Live, attenuated influenza A H5N1 candidate vaccines provide broad cross-protection in mice and ferrets.

BACKGROUND: Recent outbreaks of highly pathogenic influenza A H5N1 viruses in humans and avian species that began in Asia and have spread to other continents underscore an urgent need to develop vaccines that would protect the human population in the event of a pandemic. METHODS AND FINDINGS: Live, attenuated candidate vaccines possessing genes encoding a modified H5 hemagglutinin (HA) and a wild-type (wt) N1 neuraminidase from influenza A H5N1 viruses isolated in Hong Kong and Vietnam in 1997, 2003, and 2004, and remaining gene segments derived from the cold-adapted (ca) influenza A vaccine donor strain, influenza A/Ann Arbor/6/60 ca (H2N2), were generated by reverse genetics. The H5N1 ca vaccine viruses required trypsin for efficient growth in vitro, as predicted by the modification engineered in the gene encoding the HA, and possessed the temperature-sensitive and attenuation phenotypes specified by the internal protein genes of the ca vaccine donor strain. More importantly, the candidate vaccines were immunogenic in mice. Four weeks after receiving a single dose of 10(6) 50% tissue culture infectious doses of intranasally administered vaccines, mice were fully protected from lethality following challenge with homologous and antigenically distinct heterologous wt H5N1 viruses from different genetic sublineages (clades 1, 2, and 3) that were isolated in Asia between 1997 and 2005. Four weeks after receiving two doses of the vaccines, mice and ferrets were fully protected against pulmonary replication of homologous and heterologous wt H5N1 viruses. CONCLUSIONS: The promising findings in these preclinical studies of safety, immunogenicity, and efficacy of the H5N1 ca vaccines against antigenically diverse H5N1 vaccines provide support for their careful evaluation in Phase 1 clinical trials in humans.

Animals↗
PubMed2006

[Study on the differentiation of marrow mesenchymal stem cells of the rats mediated by bone morphogenetic protein 2].

OBJECTIVE: To explore the effect of age and gene therapy on the differentiation of marrow mesenchymal stem cells (MSCs) of the rats. METHODS: MSCs from the young (1-month-old), adult (9-month-old), and the aged (24-month-old) rats were expanded in culture and infected with adenovirus mediated human bone morphogenetic protein 2 gene (Ad-BMP-2). The expression of BMP-2 and osteoblastic markers such as alkaline phosphatase (ALP), collagen I (Col I), bone sialoprotein (BSP) and osteopontin (OPN) were assayed during the process of differentiation. Their abilities to induce ectopic bone formation in nude mice were also tested. RESULTS: There was no significant difference in the expression of BMP-2 among the 3 groups. ALP activity assay and semi-quantitative reverse transcription polymerase chain reaction(RT-PCR) demonstrated that there were no significant differences in the expression of osteoblastic markers ALP, Col- I, OPN and BSP among the 3 groups. Histomorphometric analysis indicated that there were no significant differences in the volume of the newly formed ectopic bones in nude mice among the 3 groups. CONCLUSION: MSCs obtained from the aged rats can restore their osteogenic activity following human BMP-2 gene transduction,therefore provides an alternative to treating the aged bone disease.

Animals↗
PubMed2006

[The expression and role of Fas/FasL in infantile hemangioma].

OBJECTIVE: To investigate the expression of Fas/FasL in infantile hemangiomas and discuss the role of Fas/FasL in the pathologic evolution of infantile hemangioma. METHOD: The EnVision immunohistochemical stain and RT-PCR technique was used to examine the expression of Fas/FasL protein and mRNA in the infantile hemangiomas. RESULTS: (1) In the early and middle proliferating stage, a number of infantile hemangioma cells expressed Fas. In the late proliferating stage, the number of positive cells increased obviously and the expression of Fas mRNA was reaching the strongest level. In the early regressing stage the Fas still existed in some cells and after that the expression decreased quickly. (2) Up to the middle proliferating stage, there were a few of FasL(+) cells foound. In the late proliferating stage, the number of FasL(+) cells increased significantly. From the early regressing stage, the number of FasL(+) cells decreased rapidly and disappeared. CONCLUSION: There may exist significant correlation between the expression of Fas/FasL and the development of the infantile hemangioma cells. The apoptosis of the infantile hemangioma cells mediated by Fas/ FasL may be the major reason of the spontaneous involution of infantile hemangioma.

Apoptosis↗
PubMed2006

[Cause analysis and management of severe dislocated or subluxated intraocular lenses in the capsular bag].

OBJECTIVE: To analyze the causes of severe dislocated and subluxated intraocular lenses (IOL) in capsular bag and the relevancy with abnormal capsular constitution. METHODS: The abnormality of capsular and the position of IOL were retrospectively analyzed by slit lamp and microscope in dilated pupil. Surgeries were performed in all of 31 cases in order to exchange or reposit the dislocated or subluxated lOL. RESULTS: Among 31 cases, there were 20 cases with the dislocated or subluxated IOL in the earlier postoperative period and 11 cases in the later postoperative period. The subluxated IOL in 5 cases (16.1%) were caused by the large rupture of the posterior capsular, and by the rupture of the posterior capsular in 9 cases (29.0%). A upward subluxated IOL developed in one case (3.2%) as the result of small rupture in the equater capsular. The subluxatd IOL in the anterior chamber in two cases (6.5%) was induced by the radial rupture of residual anterior capsular. The size of the IOLs in 2 cases were not matched to the diameter of the capsule bag. The dislocated IOL into the vitreous in 2 cases was caused by the rupture of the superior capsular. The subluxated IOL in 2 cases (6.5%) was caused by the zonal finers rupture due to trauma. The severe disfiguration of the IOL haptic was found in one case. The dislocated IOL in 6 cases (19.4%) was caused by asymmetric capsular shrinkage. A subluxated IOL in one case was resulted from the zonular defects with pseudoexfoliation syndrome. The postoperative corrected visual acuity was 0.5 - 1.0 in 24 eyes, 0.1 - 0.4 in 6 eyes, and 0.05 in one eye. CONCLUSIONS: There are several causes for the dislocated or subluxated IOL. The correction of the IOL position should depend on the cause for the dislocated or subluxated IOL.

Adolescent↗
PubMed2006

[Construction and application of retroviral vector system useful for high-efficiency transfection into human T cells].

AIM: To construct a retroviral vector system with high-efficiency transfection into human T cells and carrying a rapid screening label, and compare it with the traditional retroviral vector system. METHODS: Retroviral vector pCMMP-IRES-GFP was first constructed by inserting the internal ribosome entry site-green fluorescent protein (IRES-GFP) cDNA into retroviral vector pCMMP. The chimeric TCR gene was inserted into pCMMP-IRES-GFP and then co-transfected into packaging cell line 293T with other two assistant vectors pMD. MLVgag. pol and pHDM. G. After 48 h, the culture supernatant was harvested and condensed by centrifugation. Meanwhile, the chimeric TCR gene was inserted into pLXSN and then transfected into packaging cell line PA317. The transfected PA317 cells were obtained by G418 pressure screening. The cells culture supernatant containing viruses was harvested after being cultured for 48 h. The viral titer was determined by NIH3T3 cells infection. The preactivated primary human T lymphocytes were infected by appropriate volume of viral fluid and detected by fluorescent microscopy or flow cytometry after 48 h. RESULTS: A retroviral vector pCMMP-IRES-GFP was constructed successfully. Compared with the traditional vector system, the viral titer was 2.15x10(11) VP/L vs 6.43x10(9) VP/L, and efficiency of transfection into preactivated primary T cells was 50%-60% vs 5%-10%. Furthermore, the infected cells were also detected by fluorescent microscope and could sorted by fluorescent activated cell sorting. CONCLUSION: A retroviral vector system with high transfection efficiency into T lymphocytes and carrying a rapid screening label has been constructed, which establishes the foundation for basic and clinical studies on T lymphocytes.

Animals↗
PubMed2005

Mitoxantrone-loaded BSA nanospheres and chitosan nanospheres for local injection against breast cancer and its lymph node metastases. I: Formulation and in vitro characterization.

Positively charged mitoxantrone (MTO) was absorbed by negatively charged blank bovine serum albumin (BSA) and chitosan (CS) nanospheres to form MTO-BSA-NS and MTO-CS-NS, respectively. In addition to other conditions, values of pH of every step were optimized. On optimized conditions, MTO-BSA-NS of a mean size of 77 nm with an encapsulation yield (EY) of (98.86+/-1.43)% [drug loading rate (DL) (19.82+/-0.29)%] and MTO-CS-NS of a mean size of 75 nm with an EY of (97.57+/-1.00)% [DL (9.78+/-0.10)%] were obtained. After lyophilization and sterilization by (60)Co, the mean size increased about 10% but no significant change was observed in EY and DL. Tests for in vitro release in physiological saline or physiological saline containing 0.5% (w/v) ascorbic acid by a dialysis bag showed sustained release and little burst effect.

Antineoplastic Agents↗
PubMed2005

Mitoxantrone-loaded BSA nanospheres and chitosan nanospheres for local injection against breast cancer and its lymph node metastases. II: Tissue distribution and pharmacodynamics.

Bovine serum albumin (BSA) and chitosan (CS) nanospheres of mitoxantrone (MTO) were comparatively evaluated in terms of tissue distribution, acute toxicity and therapeutic efficiency against breast cancer and its lymph node metastases. After local injection in rats, MTO nanospheres showed a slower elimination rate and a much higher drug concentration in lymph nodes compared with MTO solution, and a lower drug concentration in other tissues. There was no observed acute toxicity to the main tissues of Kunming mice after local injection of MTO-BSA-NS. Mild toxicity to liver and lung was observed for MTO-CS-NS, but, for MTO solution, severe toxicity to liver and lung and much lower number of white blood cells were observed. Human MCF-7 breast cancer in nude mice and animal model of P388 lymph node metastases in Kunming mice were applied to investigate the therapeutic efficiency. The inhibition rate of the nanospheres against breast cancer was much higher than that of MTO solution, and lymph node metastases were efficiently inhibited by the nanospheres, especially MTO-BSA-NS.

Animals↗
PubMed2005

Effects of Helicobacter pylori eradication on atrophic gastritis and intestinal metaplasia: a 3-year follow-up study.

AIM: To investigate the effect of H pylori eradication on atrophic gastritis and intestinal metaplasia (IM). METHODS: Two hundred and fifty-nine patients with atrophic gastritis in the antrum were included in the study, 154 patients were selected for H pylori eradication therapy and the remaining 105 patients served as untreated group. Gastroscopy and biopsies were performed both at the beginning and at the end of a 3-year follow-up study. Gastritis was graded according to the updated Sydney system. RESULTS: One hundred and seventy-nine patients completed the follow-up, 92 of them received H pylori eradication therapy and the remaining 87 H pylori-infected patients were in the untreated group. Chronic gastritis, active gastritis and the grade of atrophy significantly decreased in H pylori eradication group (P<0.01). However, the grade of IM increased in H pylori -infected group (P<0.05). CONCLUSION: H pylori eradication may improve gastric mucosal inflammation, atrophy and prevent the progression of IM.

Adult↗
PubMed2005

Morphological changes in the Royal College of Surgeons rat retina during photoreceptor degeneration and after cell-based therapy.

There are concomitant morphological and functional changes in the inner retina during the course of photoreceptor degeneration in a range of animal models of retina degeneration and in humans with eye disease. One concern that has been raised is that the changes occurring in the inner retina might compromise attempts to rescue or restore visual input by various interventional approaches. It is known that cell-based therapy can preserve significant visual capability for many months. In this study, we examine the overall changes in the Royal College of Surgeons (RCS) rat during degeneration and the effects of cell transplantation by means of immunohistochemistry and confocal microscopy. The degenerative changes are complex, and they progress with age. They involve the neurons with which both rods and cones interconnect--retinal second- and third-order neurons underwent dramatic modification, including sprouting, retraction as photoreceptor loss progressed--as well as Müller glia and secondary vascular changes, which were associated at later times with neuronal migration. The pathological vascular changes led to major disruption of inner retina. After introducing a retinal pigment epithelial cell line to the subretinal space early in the progress of photoreceptor degeneration, most inner retinal changes were held in abeyance for up to at least 10 months of age. Given the concern that has been raised regarding whether inner retinal changes might compromise any graft-related benefit, this is an encouraging finding.

Animals↗
PubMed2005

Nitric oxide negatively regulates Fas CD95-induced apoptosis through inhibition of ubiquitin-proteasome-mediated degradation of FLICE inhibitory protein.

Stimulation of cell surface Fas (CD95) results in recruitment of cytoplasmic proteins and activation of caspase-8, which in turn activates downstream effector caspases leading to programmed cell death. Nitric oxide (NO) plays a key role in the regulation of apoptosis, but its role in Fas-induced cell death and the underlying mechanism are largely unknown. Here we show that stimulation of the Fas receptor by its ligand (FasL) results in rapid generation of NO and concomitant decrease in cellular FLICE inhibitory protein (FLIP) expression without significant effect on Fas and Fas-associated death domain (FADD) adapter protein levels. FLIP down-regulation as well as caspase-8 activation and apoptosis induced by FasL were all inhibited by the NO-liberating agent sodium nitroprusside and dipropylenetriamine NONOate, whereas the NO synthase inhibitor aminoguanidine and NO scavenger 2-(4-carboxyphenyl)-4,4,5,5-tetramethyl-imidazoline-1-oxyl-3-oxide (PTIO) had opposite effects, indicating an anti-apoptotic role of NO in the Fas signaling process. FasL-induced down-regulation of FLIP is mediated by a ubiquitin-proteasome pathway that is negatively regulated by NO. S-nitrosylation of FLIP is an important mechanism rendering FLIP resistant to ubiquitination and proteasomal degradation by FasL. Deletion analysis shows that the caspase-like domain of FLIP is a key target for S-nitrosylation by NO, and mutations of its cysteine 254 and cysteine 259 residues completely inhibit S-nitrosylation, leading to increased ubiquitination and proteasomal degradation of FLIP. These findings indicate a novel pathway for NO regulation of FLIP that provides a key mechanism for apoptosis regulation and a potential new target for intervention in death receptor-associated diseases.

Apoptosis↗
PubMed2005

Re-establishing the regenerative potential of central nervous system axons in postnatal mice.

At a certain point in development, axons in the mammalian central nervous system lose their ability to regenerate after injury. Using the optic nerve model, we show that this growth failure coincides with two developmental events: the loss of Bcl-2 expression by neurons and the maturation of astrocytes. Before postnatal day 4, when astrocytes are immature, overexpression of Bcl-2 alone supported robust and rapid optic nerve regeneration over long distances, leading to innervation of brain targets by day 4 in mice. As astrocytes matured after postnatal day 4, axonal regeneration was inhibited in mice overexpressing Bcl-2. Concurrent induction of Bcl-2 and attenuation of reactive gliosis reversed the failure of CNS axonal re-elongation in postnatal mice and led to rapid axonal regeneration over long distances and reinnervation of the brain targets by a majority of severed optic nerve fibers up to 2 weeks of age. These results suggest that an early postnatal downregulation of Bcl-2 and post-traumatic reactive gliosis are two important elements of axon regenerative failure in the CNS.

Animals↗
PubMed2005

Regulation of Fas (CD95)-induced apoptotic and necrotic cell death by reactive oxygen species in macrophages.

Although reactive oxygen species (ROS) have long been suspected to play a key role in Fas (CD95)-induced cell death, the identity of specific ROS involved in this process and the relationship between apoptotic and necrotic cell death induced by Fas are largely unknown. Using electron spin resonance (ESR) spectroscopy, we showed that activation of Fas receptor by its ligand (FasL) in macrophages resulted in a rapid and transient production of hydrogen peroxide (H2O2) and hydroxyl radicals (*OH). The response was visible as early as 5 min and peaked at approximately 45 min post-treatment. Morphological analysis of total death response (apoptosis vs. necrosis) showed dose and time dependency with apoptosis significantly increased at 6 h after the treatment, while necrosis remained at a baseline level. Only at a 35-fold increase in apoptosis did necrosis become significant. Inhibition of apoptosis by a pan-caspase inhibitor, benzyloxycarbonyl-Val-Ala-Asp-(OMe) fluoromethyl ketone (zVAD-fmk), significantly inhibited cell necrosis, indicating the linkage between the two events. Catalase (H2O2 scavenger) and deferoxamine (*OH scavenger) effectively inhibited the total death response as well as the ESR signals, while superoxide dismutase (SOD) (O2*- scavenger) had minimal effects. These results established the role for H2O2 and *OH as key participants in Fas-induced cell death and indicated apoptosis as a primary mode of cell death preceding necrosis. Because the Fas death pathway is implicated in various inflammatory and immunologic disorders, utilization of antioxidants and apoptosis inhibitors as potential therapeutic agents may be advantageous.

Animals↗