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Biomedical subjects

Yan Jin

Publications and source records attributed to Yan Jin.

At least 109 records · Page 6Linked to original sources
PubMed2004

[Induction of transforming growth factor-beta 1 and dentin non-collagen proteins on tissue engineering pulp].

OBJECTIVE: To study the influence of transforming growth factor-beta 1 (TGF-beta 1), dentin non-collagen proteins (dNCPs) and their complex on tissue engineering pulp system. METHODS: Collagen I and dentin powder were used to construct the system of pulp cells in 3-dimensional culture, dentin powder was added in the gel. The tissue engineering pulp were divided TGF-beta 1 group, dNCPs group, TGF-beta 1/dNCPs group and control group. After 3, 6 and 14 days, the appearance and the differentiation of pulp cells were observed by HE staining and immunohistochemical staining respectively. RESULTS: Collagen I could form netted collagen gel construction. Growing condition of pulp cells in gel was similar to that of pulp cells in vivo. After the TGF-beta 1 and dNCPs were added, the pulp cells had some characteristics of odontoblasts and had unilateral cell process after culture 6 days. Pulp cells arranged with parallel columnar and form dentin-pulp-like complex after 14 days. Immunohistochemical staining showed dentin salivary protein (DSP) began to express in some cells. The number of positive cell was most in the TGF-beta 1 group. No positive cells were detected in the control group. CONCLUSION: The transforming growth factor-beta 1 and non-collagen proteins can stimulate the pulp cells to transform into odontoblasts to some extent, which promote the formation of tissue engineering pulp.

Animals↗
PubMed2004

[Induced differentiation of ectomesenchymal stem cells of human embryo facial process into osteoblast in vitro].

OBJECTIVE: To investigate the possibility of ectomesenchymal stem cell of human embryo facial process in differentiating into osteoblasts. METHODS: Ectomesenchymal stem cells of human embryo facial process were isolated and cultured in mineralized promoting solution containing 10 mmol/L beta-glycerophosphate, 100 microg/ml ascorbic acid and 10 nmol/L dexamethasone supplemented with 15% FBS. The morphological change was observed by phase contrast microscopy. The characteristics of cells was identified by immunohistochemistry assay. Alkaline phosphatase activity was tested and the form of mineralized nodules was tested with Von Kossa staining. The expression of osteocalcin was identified by RT-PCR. RESULTS: There were significant changes in the shape of the cells after 3 days cultured in mineralized promoting solution. The cells became larger and the shape changed from fibroblast-like to multilateral. The result for anti-collogen type I staining was positive. The alkaline phosphatase activity increased. Mineralized nodules were formed after cultured 25 days by Von Kossa staining. RT-PCR assay showed induced cells expressed osteocalcin. CONCLUSION: Ectomesenchymal stem cells of human embryo facial process can be induced to differentiate into osteoblasts by mineralized promoting solution.

Cell Differentiation↗
PubMed2004

[Recombinant human bone morphogenetic protein-2 transform NIH3T3 fibroblast to osteo-like cells].

OBJECTIVE: To examine the effect of recombinant human bone morphogenetic protein-2 (rhBMP-2) on NIH3T3 cells. METHODS: The NIH3T3 cells were cultured in DMEM with 50 microg/L rhBMP-2. The proliferation ability, alkaline phosphatase (ALP) activity and osteocalcin (OC) quantity of NIH3T3 cells were investigated. RESULTS: The cells showed decreased proliferation ability but enhanced ALP activity and OC quantity. CONCLUSION: 50 microg/L rhBMP-2 can transform NIH3T3 fibroblasts to osteo-like cells.

Alkaline Phosphatase↗
PubMed2004

[Construction of a tissue engineering skin containing capillary-like network].

OBJECTIVE: To construct a tissue engineering skin containing capillary-like network by employing tissue engineering method. METHODS: The numan umbilical vein endothelial cells(HUVECs) were isolated from a new-born umbilical cord. The keratinocytes and dermal fibroblasts were isolated from a new-born foreskin biopsy. After the collagen gel was prepared, the fibroblasts and the vascular endothelial cells were added in a ratio of 1 to 1 to construct a skin substitute containing capillary-like network. The skin substitute was observed by HE staining and immuno histochemical staining (VIII factor). The reconstructed skin containing capillary-like network was used to repair the nude mice skin defects in the experimental group. The tissue engineering skin containing no vascular endothelial cells was used in control group. RESULTS: Capillary-like network could be observed in the dermal layer of the tissue engineering skin, and the nude mice skin defects were repaired by the skin substitutes in the experimental group. In control group, no capillary-like network was found. CONCLUSION: The tissue engineering skin containing capillary-like network is successfully constructed in vitro and can be used to repair the full-thickness skin defects.

Animals↗
PubMed2004

[Comparison studies on epidermis cell culture efficiency between big graft method and small strip method].

OBJECTIVE: To compare the efficiency of epidermis cell culture between big graft method and small strip method. METHODS: The big graft method was to cut the skin tissue reticularly from dermis layer while the epidermis were not cut off. After it was digested fully in trypsin, the epidermis was separated from skin and was used to culture epidermal cells. The small strip method was routine. The time to cut the skin and to separate the epidermis was recorded, and the number and quality of cells were compared between two methods. RESULTS: It took 8-10 minutes to cut an area of 5 cm2 skin into small strips and 1-2 minutes into big grafts. It took 10-15 minutes to separate the epidermis from the same area skin by small strip method and 2 minutes by big graft method. The cells showed better vigor and its number was more by big grafts than by small strips. The chance of fibroblast contamination was reduced obviously. CONCLUSION: The big graft method is simpler than the small strip method and can culture more epidermis cells with less chance of fibroblast contamination.

Animals↗
PubMed2004

[The positive effect of transforming growth factor beta on ectomesenchymal stem cells of embryonic facial processes differentiating to smooth muscle cells].

OBJECTIVE: To investigate the effect of transforming growth factor beta (TGF-beta) on ectomesenchymal stem cells differentiating to smooth muscle cells. METHODS: 60 pmol/L TGF-beta was added to the ectomesenchymal stem cells of embryonic facial processes. Immunohistochemistry assay and image analysis were used to value the expression extent of a smooth muscle actin (alpha-SMA) and quantitative RT-PCR was used to value the quantity of alpha-SMA. RESULTS: 2 days later, about 95% cells in TGF-beta group and 65% cells in control group without differentiation inhibitor expressed alpha-SMA. Expression of alpha-SMA in TGF-beta group was stronger than that of control group after one and two days. Quantitative RT-PCR showed the quantity of alpha-SMA mRNA in treated group cells was more than that of in control group. CONCLUSION: Quantity of alpha-SMA in TGF-beta group is more than that of spontaneous differentiation group. TGF-beta has positive effect on ectomesenchymal stem cells differentiating to smooth muscle cells.

Actins↗
PubMed2004

The effect of age upon care and outcomes in patients hospitalized for congestive heart failure in Alberta, Canada.

We describe the age-specific outcomes for patients hospitalized with newly diagnosed congestive heart failure using administrative hospital abstracts from Alberta, Canada, from April 1, 1994, to March 31, 2000. Seniors (aged 65 years and older) constituted about 85 per cent of the 16,162 patients. Both co-morbidity and severity of illness tended to increase with age. The use of special care unit admissions, coronary artery diagnostic services (cardiac catheterization), and revascularization procedures (percutaneous transluminal coronary angioplasty/stenting, coronary artery bypass surgery) peaked in the 50-to 64-year age group and decreased with increasing age. Specialist/sub-specialist care, prescriptions of beta blockers and angiotensin-converting enzyme inhibitors / angiotensin receptor blockers decreased with age in seniors. Adjusted in-hospital, 1-year mortality and crude, age-specific 5-year mortality were significantly greater in those 75 years and older. Outcomes and process of care in patients with newly diagnosed congestive heart failure were not uniformly distributed with age. The elderly had greater mortality but received less therapy.

Adult↗
PubMed2003

Binding of AP-2 and ETS-domain family members is associated with enhancer activity in the hypersensitive site III region of the human growth hormone/chorionic somatomammotropin locus.

The human GH gene family is specifically expressed in somatotrophs of the anterior pituitary and placental syncytiotrophoblast. Two nuclease-hypersensitive sites, HS III and HS V, are associated with a region of chromatin located 28 and 30 kb upstream of the pituitary GH gene transcription initiation site (+1) in both pituitary and placenta nuclei. A role for this region in pituitary GH gene expression has been reported, but the potential relevance to placental gene expression has not been determined. Deletion analysis of a 5.2-kb region (nucleotides - 27,568/-32,746) containing HS III to V-related sequences localized significant enhancer activity to a 574-bp HS III fragment (nucleotides -27,676/-28,249) in multiple transfected cell lines. Four nuclease-protected regions [footprints (FP) 1-4] were identified in the 574-bp fragment. FP2 and FP3 were detected with placenta cell nuclear protein, whereas FP1 and FP4 were observed with placental and nonplacental cell nuclear extract. Disruption of FP1 had no effect on heterologous promoter activity in transfected pituitary and placental cells, whereas loss of FP2 and FP3 resulted in modest increases in placental cells, reflecting the presence of repressor activity associated with these regions in vitro. In contrast, disruption of the FP4 region by mutation or deletion significantly reduced enhancer activity. As a result, 30-fold enhancer activity was localized to a 41-bp region in transfected placental tumor cells. Binding of candidate proteins, activator protein (AP)-2 (FP3) and Elk-1 (FP4), was confirmed using competition assays with specific oligonucleotides and antibodies. Moreover, these factors were associated with the hyperacetylated HS III region in human pituitary [activator protein 2 (AP-2) and Elk-1] and term placenta (AP-2) chromatin. These data implicate AP-2 and ETS-domain family members in the regulation of the GH/CS locus and raise the possibility that different complexes form in the HS III region in placenta and pituitary cells.

Acetylation↗
PubMed2003

Induction of cell death of gastric cancer cells by a modified compound of the annonaceous acetogenin family.

Annonaceous acetogenins are a family of natural products with antitumor activities. The polyether mimic AA005 has been synthesized. The cytotoxic mechanism of AA005 was investigated. It was found that AA005 can induce the cell death of gastric tumor cells. Most AA005-induced cell death is due to necrosis but partial and p53-independent apoptosis is also detected. An expanded study with gastric tumor cells and a cell-free system indicates that AA005 affects NADH:ubiquinone oxidoreductase (complex I; NADH=nicotinamide adenine dinucleotide, reduced form) in the mitochondrial electron transport system. These results show for the first time that the polyether mimic AA005 acts on the same biological target as the natural annonaceous acetogenins.

Annonaceae↗
PubMed2003

Colloid-facilitated Cs transport through water-saturated Hanford sediment and Ottawa sand.

In this study, a series of saturated column experiments were conducted to investigate effects of colloids on Cs transport in two types of porous media (Hanford sediment characteristic of 2:1 clay minerals and silica Ottawa sand). The colloids used were obtained by reacting Hanford sediment with simulated tank waste solutions. Because of the highly nonlinear nature of Cs sorption found in batch experiments, we used two different concentrations of Cs (7.5 x 10(-5) M and 1.4 x 10(-8) M) for the transport experiments. The presence of colloids facilitated the transport of Cs through both Hanford sediment and Ottawa sand via association of Cs with mobile colloidal particles. Due to the nonlinearity of the Cs sorption, the colloid-facilitated Cs transportwas more pronounced atthe low Cs concentration (1.4 x 10(-8) M) than at the high concentration (7.5 x 10(-5) M) when expressed relative to the inflow Cs concentration. In the absence of colloids, no Cs moved through the 10-cm long columns during the experiment within about 20 pore volumes, exceptfor the high Cs concentration in the Ottawa sand where a complete Cs breakthrough was obtained. Also, it was found that colloid-associated Cs could be partially stripped off from colloids during the transport. The stripping effect was controlled by both Cs concentration and sorption capacity of the transport matrix.

Cesium↗
PubMed2003

Beta-blockers and angiotensin-converting enzyme inhibitors/receptor blockers prescriptions after hospital discharge for heart failure are associated with decreased mortality in Alberta, Canada.

OBJECTIVES: We sought to evaluate the common utilization of beta-blockers and angiotensin-converting enzyme (ACE) inhibitors or receptor blockers (RBs) in congestive heart failure (CHF). BACKGROUND: We assessed the association between prescriptions of beta-blockers and ACE inhibitors or RBs within three months after hospitalization and mortality for newly diagnosed CHF in Alberta, Canada seniors (age 65 years and older). METHODS: Administrative hospital discharge abstracts and drug data during October 1, 1994, to December 31, 1999, were analyzed. RESULTS: There were 11854 hospitalizations for newly diagnosed CHF. The use of beta-blockers within three months after hospitalization increased from 7.3% in 1994-1995 to 20.9% in 1999-2000. The use of ACE inhibitor or RBs within three months after hospitalization increased from 31.0% in 1994-1995 to 44.3% in 1999-2000. Adjusted one-year mortality was lower in seniors with prescriptions for beta-blockers (18.2%; 95% confidence interval [CI] 14.2 to 22.2), ACE inhibitors/RBs (22.3%; 95% CI 20.9 to 23.7), or both (16.6%; 95% CI 13.3 to 20.0), compared with those with no prescriptions (29.9%; 95% CI 28.8 to 31.0). Absolute adjusted risk reduction comparing no prescription with prescription of both beta-blockers or ACE inhibitors/RBs was 13.3% for a relative adjusted risk reduction of 44%. CONCLUSIONS: This study of incident CHF hospitalizations among seniors demonstrates an association between decreased mortality and the use of beta-blockers, ACE inhibitors/RBs, or combination of both. The effectiveness of beta-blockers and ACE inhibitors/RBs for CHF should be more broadly tested in clinical trials that recruit older patients and those with diastolic dysfunction.

Adrenergic beta-Antagonists↗
PubMed2003

Factors associated with death among adults <55 years of age hospitalized for community-acquired pneumonia.

An administrative database was used to study death occurring among adults aged 18-55 years who were hospitalized during the period from 1 April 1994 through 31 March 1999 for treatment of community-acquired pneumonia. In-hospital case-fatality rates for the first 10 days of hospitalization and overall were 2.1% and 3.2%, respectively, for 11,684 patient hospitalizations. Patient factors (age, sex, and comorbidity) were the most important associations with death. Aspiration provided the largest explanation of variance in deaths occurring during the first 10 days of hospitalization (odds ratio, 5.0; 95% confidence interval, 3.7-6.8). Busy hospitals (higher occupancy and higher number of daily admissions) were not associated with higher case-fatality rates. Bigger hospitals (metropolitan hospitals) had higher case-fatality rates, but this was more likely related to greater comorbidity and severity of pneumonia. Death due to community-acquired pneumonia among young and middle-aged adults is infrequent and is more related to the severity of pneumonia and to such risk factors as aspiration than to the manner in which the provision of care is organized.

Adolescent↗
PubMed2003

Virus retention and transport through Al-oxide coated sand columns: effects of ionic strength and composition.

Knowledge of the factors that influence the fate and transport of viruses in porous media is very important for accurately determining groundwater vulnerability and for developing protective regulations. In this study, six saturated sand column experiments were performed to examine the effects of a positively charged Al-oxide, which was coated on sand particles, on the retention and transport of viruses (phiX174 and MS-2) in background solutions of different ionic strength and composition. We found that the Al-oxide coating on sand significantly removed viruses during their transport in a phosphate buffered saline (PBS) solution. Mass balance calculations showed that 34% of the input MS-2 was inactivated/irreversibly sorbed on the surface of Al-oxide coated sand whereas 100% of phiX174 was recovered. Results from this study also indicated that higher ionic strength facilitated the transport of both phiX174 and MS-2 through the Al-oxide coated sand. This was attributed to the effect of ion shielding, which at higher ionic strength decreased the electrostatic attraction between the viral particles and the sand surface and consequently decreased virus sorption. Strong effect of the ionic strength indicates that an outer-sphere complexation mechanism was responsible for the virus sorption on the Al-oxide coated sand. Ion composition of the background solutions was also found to be a significant factor in influencing virus retention and transport. Virus transport was enhanced in the presence of phosphate (HPO(4)(2-)) as compared to bicarbonate (HCO(3)(-)), and the effect of HPO(4)(2-) was more significant on MS-2 than on phiX174. The presence of bivalent cations (Ca(2+) and Mg(2+)) increased virus transport because the cations partially screened the negative charges on the viruses therefore decreased the electrostatic attraction between the positively charged sand surface and the negatively charged viruses. Mass recovery data indicated that bivalent cations gave rise to a certain degree of inactivation/irreversibly sorption of phiX174 on the surface of Al-oxide coated sand. On the contrary, the bivalent cations appeared to have protected MS-2 from inactivation/irreversibly sorption. This study provides some insights into the mechanisms responsible for virus retention and transport in porous media.

Aluminum Oxide↗
PubMed2003

Rural and urban outcomes after hospitalization for congestive heart failure in Alberta, Canada.

OBJECTIVES: We compare the hospitalization rate, duration, cost, and mortality for newly diagnosed congestive heart failure in patients admitted to rural and metropolitan hospitals in one Canadian province. METHODS: Administrative data for Alberta, Canada, from April 1, 1994, to March 31, 2000. RESULTS: Hospitalizations (16,162) for newly diagnosed congestive heart failure constituted 50% of all hospitalizations for congestive heart failure. Hospitals were distributed as follows: rural with less than 200 cases (21% of hospitalizations), rural with 204 to 646 cases (21% of hospitalizations), regional (13% of hospitalizations), metropolitan with angiography capability (24% of hospitalizations), and metropolitan without angiography capability (21% of hospitalizations). The hospitalization rate per 1000 population was lower for residents of metropolitan regions (1.01; 95% confidence interval [CI] 0.97 to 1.05) compared with residents of rural (1.70; 95% CI 1.65 to 1.75) and regional (1.95; 95% CI 1.90 to 2.00) health regions. Patient comorbidity and severity scores were lower in rural hospitals. Special care unit admissions and cardiac catheterizations were more frequent in patients admitted to metropolitan hospitals. After adjustment, the length of stay and mortality were similar amongst all hospital types. Adjusted hospital total costs were about 23% (900 Canadian dollars) greater in metropolitan hospitals with angiography capability compared to rural hospitals. CONCLUSION: Hospital admission rates for newly diagnosed congestive heart failure were lower for metropolitan residents compared to non-metropolitan residents. Cost per admission was greatest in metropolitan hospitals with angiography capability compared to other hospital types.

Adult↗
PubMed2003

The effects of community-acquired pneumonia during pregnancy ending with a live birth.

OBJECTIVE: The incidence and outcomes for community-acquired pneumonia during a pregnancy ending with a live birth in the province of Alberta, Canada, were analyzed. STUDY DESIGN: Hospital abstracts and vital statistics data between April 1, 1994, to March 31, 1999, were used. RESULTS: The incidence of hospitalization for community-acquired pneumonia was 1.51 (95% CI 1.35-1.67) per 1000 pregnancies in mothers 18 years and older compared with 1.47 (95% CI 1.42-1.51) per 1000 women (18 to 49 years) in the general population. The relative risk of staying longer at hospital for pneumonia was 0.44 during pregnancy compared with nonpregnant mothers with pneumonia. The relative risk of staying longer at hospital during delivery was 1.88, higher in those with a past hospitalization for community-acquired pneumonia. The relative risk of a small-for-gestational-age newborn infant was 1.86 for those with a past hospitalization for community-acquired pneumonia compared with those without a past hospitalization. CONCLUSION: Community-acquired pneumonia during most pregnancies ending with a live birth appears to be well tolerated by mothers and newborn infants.

Adult↗