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Biomedical subjects

J Lu

Publications and source records attributed to J Lu.

At least 325 records · Page 18Linked to original sources
PubMed1999

[Studies on tannin and hydrolysate in three species of Chinese Caesalpinia plants].

OBJECTIVE: To get Chinese Caesalpinia plants that can replace the imported Tara to produce tannin and gallic acid. METHOD: Extract tannin with water, condense and hydrolyze the extracts with alkali, the hydrolysates were identified. Furthermore, an enlarged scale experiment was conducted. RESULT: Tannin contents of the plants were 32.2%, 46.6% and 58.5% respectively, the converted ratios of raw material to hydrolysate were 154:1, 11.8:1, 3.09-2.79:1 respectively. CONCLUSION: We got the Tara-replacing plants in Chinese Caesalpinia plants for the first time.

Caesalpinia↗
PubMed1999

[Species and distribution of Chinese medicinal plant Caesalpinia].

OBJECTIVE: To gain a clear idea on the resources of medicinal plant Caesalpinia in China. METHOD: Conducting field investigation and consulting related specimens and data. RESULT: The distribution, growing environment and medicinal parts of 14 species of Caesalpinia have been clarified, and a key for their identification is given. CONCLUSION: A scientific basis for further study of the medicinal plant Caesalpinia in China has been provided.

Caesalpinia↗
PubMed1999

[Investigation on the fruit output and ecological environment of Caesalpinia in China].

OBJECTIVE: To estimate the fruit output of Caesalpinia in China and understand its ecological environment. METHOD: On-the-spot investigation in the producing area. RESULT: The output of 8 species of Caesalpinia was estimated and their ecological environment was described. CONCLUSION: The natural resources of Chinese Caesalpinia, especially C. decapetala and C. minax, are rich, and thus worth exploring and developing.

Caesalpinia↗
PubMed1999

[Comparison of protocatechuic aldehyde in different processed products of Salvia miltiorrhiza].

The contents of Protocatechuic aldehyde in crude and four different processed products of Salvia miltiorrhiza were determined by HPLC. The results showed that, after processing, the contents of Protocatechuic aldehyde decreased in varying degrees. Among them, the processed products fried with wine, vinegar and no materials decreased 17.14%, 20.00% and 42.86% respectively. The carbonized product decreased 60.86%.

Acetic Acid↗
PubMed1999

[Electron microscope observation on effect of kudingcha inspissation tea on small intestine villus in the adiposity rats].

OBJECTIVE: Experimental study on pharmacological action of Guang Dong kudingcha inspissation tea on small intestine villus in the adiposity rats (nutrition obesity). METHODS: By using electron microscope method, check on small intestine villus of 60 experiment rats of just wean and count and analyse and conclude. RESULTS: Under the scan electron imcroscope, the surface configuration on small intestine villus of model group and various kudingcha dosage groups is similar to the blank (P > 0.05), but fenfluramine group appear constriction on top end of small intestine villus. CONCLUSION: Compring with fenfluramine, Guang Dong kudingcha inspissation tea has not effect on configuration of small intestine of adiposity rats (nutrition obesity), but has more strong modulation function on fat tissue lipocyte hypertrophy and quantitative.

Adipocytes↗
PubMed1999

[Study on the inclusion of oridonin-beta-cyclodextrin].

The inclusion compound of Oridonin-beta-cyclodextrin was prepared by the liquid-phase method in aqueous solution. And it was confirmed by thin layer chromatography, differential thermal analysis and specific rotation. The change (A) of ultraviolet spectrum was determined. The composition ratio of inclusion compound between Oridonin and beta-CD was obtained by the continuous variation method.

Calorimetry, Differential Scanning↗
PubMed1999

[Optimization of productivity of Epstein-Barr virus membrane antigen in baculovirus infected insect cells].

OBJECTIVE: To probe factors influencing the expression level of in insect cells. METHODS: Insect cells at different growth phases and in different culture media were infected with recombinant baculovirus carrying EBV-MA gene, where the membrane anchor sequence was deleted. The expression level of EBV-MA was detected by immunodots assay and scanner analysis. RESULTS: Cells at the early exponential phase yielded more expressed recombinant EBV-MA than those at the late exponential and stationary phases. Infected cells supplemented with fresh medium at various phases of growth resulted in improved productivity of EBV-MA. Further experiments revealed that replacing fresh medium prior to infection and supplementing a mixture of glucose and glutamine after infection, the productivity could be improved dramatically. Comparing the productivity of EBV-MA expressed in sf9 cells with that in sf21 cells, no obvious difference was found. CONCLUSION: Consumption of nutrients and accumulation of metabolites in cell culture media were the important factors influencing the productivity of EBV-MA in insect cells.

Animals↗
PubMed1998

[Effects of Trp64Arg mutation in the beta 3-adrenergic receptor gene on body fat, plasma glucose level, lipid profile, insulin secretion and action in Chinese].

OBJECTIVE: To ascertain the association of the Trp64Arg mutation in the beta 3-adrenergic receptor (ADRB3) gene with the total body fat and fat distribution, plasma glucose level, lipid profile, insulin secretion and action in Chinese. METHODS: Genotyping of the Trp64Arg mutation in the ADRB3 gene as well as measurment of clinical variables body mass index(BMI), percent of desirable weight(PDW), area of regional adipose tissue depots, fasting lipid profile, and also, plasma glucose, insulin, C-peptide, free fatty acids levels before and after glucose challenge and blood pressure were performed in 308 Chinese, of whom, 161 were nondiabetics and 147, type 2 diabetic subjects. RESULTS: (1) The frequency of Arg64 allele of ADRB3 gene in Chinese was similar to that in Japanese but slightly higher than that in Caucasians. (2) No association of any of the clinical varaibles with Trp64Arg mutation was observed in nondiabetics. (3) The Trp64Arg mutation in the ADRB3 gene was associated with BMI(P=0.019), PDW(P=0.001) and waist circumference (P=0.045) in type 2 diabetic subjects. In female diabetic subjects, more significant association with BMI(P=0.001), PDW(P=0.001), waist circumference(P=0.023), and also, association with abdominal and femoral subcutaneous fat area(P=0.032 and P=0.023) were observed. The frequencies of Arg64 allele were 21%, 14% and 4% in female diabetics with obesity, over-weight and normal-weight respectively (P=0.026). Logistic regression analysis showed that BMI was the only independent clinical variable related to the Trp64Arg mutation in the ADRB3 gene (P=0.0027). CONCLUSION: The Trp64Arg mutation in ADRB3 gene contributes to the variation of total body fat in Chinese type 2 diabetic subjects.

Adipose Tissue↗
PubMed1998

Differential regulation of androgen and glucocorticoid receptors by retinoblastoma protein.

The androgen receptor (AR) plays a major role in the development and maintenance of male primary and secondary sexual characteristics. The growth promoting effects of androgens are clearly seen in prostate cancer where treatment by androgen ablation usually leads to tumor regression, followed sometime later, by growth of tumor cells that are resistant to endocrine therapy. We have found that the level of pRB in cells controls AR activity. Overexpression of pRB leads to increased transcriptional activity of the AR. This is similar to the previously reported potentiation of glucocorticoid receptor activity by pRB. In contrast, loss of pRB activity inhibits AR but not glucocorticoid receptor activity. This inhibition correlates with the unique ability of the AR to form a protein-protein complex with pRB in vitro. The site of interaction with pRB lies within the N-terminal domain of the AR and co-localizes with the region of the AR that specifies a requirement for pRB. Thus, the AR has a novel requirement for pRB raising the possibility that the growth promoting activity of AR is due to its direct interaction with pRB. Furthermore, loss of pRB activity during progression of prostate cancer may directly result in a decreased response to androgens.

Binding Sites↗
PubMed1998

LIGHT, a novel ligand for lymphotoxin beta receptor and TR2/HVEM induces apoptosis and suppresses in vivo tumor formation via gene transfer.

LIGHT is a new member of tumor necrosis factor (TNF) cytokine family derived from an activated T cell cDNA library. LIGHT mRNA is highly expressed in splenocytes, activated PBL, CD8(+) tumor infiltrating lymphocytes, granulocytes, and monocytes but not in the thymus and the tumor cells examined. Introduction of LIGHT cDNA into MDA-MB-231 human breast carcinoma caused complete tumor suppression in vivo. Histological examination showed marked neutrophil infiltration and necrosis in LIGHT expressing but not in the parental or the Neo-transfected MDA-MB-231 tumors. Interferon gamma (IFNgamma) dramatically enhances LIGHT-mediated apoptosis. LIGHT protein triggers apoptosis of various tumor cells expressing both lymphotoxin beta receptor (LTbetaR) and TR2/HVEM receptors, and its cytotoxicity can be blocked specifically by addition of a LTbetaR-Fc or a TR2/HVEM-Fc fusion protein. However, LIGHT was not cytolytic to the tumor cells that express only the LTbetaR or the TR2/HVEM or hematopoietic cells examined that express only the TR2/HVEM, such as PBL, Jurkat cells, or CD8(+) TIL cells. In contrast, treatment of the activated PBL with LIGHT resulted in release of IFNgamma. Our data suggest that LIGHT triggers distinct biological responses based on the expression patterns of its receptors on the target cells. Thus, LIGHT may play a role in the immune modulation and have a potential value in cancer therapy.

Apoptosis↗
PubMed1998

Cloning and thermostability of TaqI endonuclease isoschizomers from Thermus species SM32 and Thermus filiformis Tok6A1.

Two TaqI endonuclease (hereafter referred to as TaqI) isoschizomer genes, tsp32IR from Thermus species SM32 of Azores and tfiTok6A1I from T. filiformis Tok6A1 of New Zealand, were cloned in Escherichia coli. The overexpressed enzymes were partly purified and their thermostability was determined. In the medium-salt buffer, Tsp32IR, TfiTok6A1I and one previously cloned TaqI isoschizomer (TthHB8I) were more thermostable than TaqI. Tsp32IR remained partly active up to 90 degreesC in the low-salt buffer. Six amino acid residues that are identical in the three high thermostability isoschizomers (Tsp32IR, TfiTok6A1I and TthHB8I) but differ in TaqI might provide added rigidity for thermostabilization. These include four proline residues located in or near loop regions, and one alanine and one arginine located at helix regions in the predicted TaqI endonuclease secondary structure. The possible role of these residues in thermostabilization was evaluated by mutagenizing the TaqI enzyme. Mutants generated at these six positions were less thermostable than wild-type TaqI. The results suggest that the surrounding sequence or structural context might be as important as the mutation itself.

Amino Acid Sequence↗
PubMed1998

Antinociceptive tolerance to the mu-opioid agonist DAMGO is dose-dependently reduced by MK-801 in rats.

Morphine has been used in previous studies that investigate interactions between the spinal cord mu-opioid and N-methyl-D-aspartate (NMDA) receptors in mechanisms of antinociceptive tolerance. Although morphine acts primarily on the mu-receptor, it also activates other subtypes of opioid receptors. In the present study, the selective mu-opioid agonist, D-Ala2-N-Me-Phe4,Gly-ol5-enkephalin (DAMGO), was used to further test the hypothesis. Repeated intrathecal (i.t.) administration of 6 microg DAMGO (twice daily) in rats for 7 days resulted in an approximately 17-fold rightward shift of the cumulative dose-response curve (the tail-flick test) on Day 8 compared to that on Day 1. This rightward shift of the dose-response curve was prevented by the i.t. co-administration with DAMGO of the NMDA receptor antagonist MK-801 (10 = 5 > 2.5 >> 1.25 nmol > saline). Further, a lower dose range of MK-801 (2.5 > 1.25 nmol > 0.625 > 0.313 = saline) was effective to prevent the antinociceptive tolerance to a lower dose (1.5 microg) of DAMGO using the same i.t. administration regimen. Thus, the present results provide further evidence supporting a cellular and intracellular model of opioid tolerance involving interactions between the mu-opioid and the NMDA receptors in the spinal cord.

Analgesics↗
PubMed1998

Anatomic considerations of anterior transarticular screw fixation for atlantoaxial instability.

STUDY DESIGN: Anatomic parameters of C1 and C2 were measured in 30 dried human cervical spines. Anterior transarticular C1-C2 screws were placed in 15 cadaveric spines. OBJECTIVE: To provide anatomic data for anterior transarticular atlantoaxial screw or C1-C2 screw and plate fixation. SUMMARY OF BACKGROUND DATA: A posterior approach to fixation in the atlantoaxial joint has been well described. Damage to the vertebral artery is documented as a rare complication of posterior atlantoaxial transarticular screw fixation. An anterior surgical approach to exposing the upper cervical spine for internal fixation and bone graft recently has been developed. No anatomic information regarding the anterior transarticular atlantoaxial screw or screw and plate fixation between C1 and C2 is available in the literature. METHODS: Direct measurements using digital calipers and a goniometer were taken from 30 pairs of dried human C1 and C2 vertebrae. The anterior transarticular C1-C2 screw insertion point is at the junction of the lateral edge of the C2 vertebral body to 4 mm above the inferior edge of the C2 anterior arch. The parameters related to anterior transarticular atlantoaxial screw fixation or screw and plate fixation between the C1 lateral mass and the C2 vertebral body were measured. Fifteen embalmed cadavers were used for anterior C1-C2 transarticular screw placement. Longer screws (30-40 mm) were used to detect whether the screw tips violated the upper cervical canal or vertebral arteries. RESULTS: In the anterior transarticular atlantoaxial screw placement, lateral angulation of the screw placement relative to sagittal plane ranged from 4.8 +/- 1.8 degrees to 25.3 +/- 2.6 degrees. The posterior angulation of the screw placement relative to the coronal plane ranged from 12.8 +/- 3.1 degrees to 22.6 +/- 3.2 degrees. The length of the medial screw path ranged from 14.7 +/- 1.5 mm to 25.4 +/- 2.8 mm. In the anterior screw and plate fixation, the anteroposterior diameter of the inferior facet articular surface ranged from 16.2 +/- 1.6 mm to 17.1 +/- 1.8 mm. The anteroposterior diameter of the C2 vertebral body ranged from 9.3 +/- 1 mm to 16.2 +/- 1.8 mm. The anterior prevascular retropharyngeal approach appropriately exposed the atlantoaxial joint for anterior transarticular C1-C2 screw placement. No screws violated the vertebral artery and cervical canal. CONCLUSIONS: An anterior transarticular atlantoaxial screw 15-25 mm long can be inserted with a lateral angulation of 5-25 degrees relative to the sagittal plane and a posterior angulation of 10-25 degrees relative to the coronal plane. Additionally, in C1-C2 anterior plate fixation screws 15 mm long could be anchored in the inferior facet of the C1, and screws 9-15 mm long could be anchored in the C2 vertebral body.

Aged↗