Biomedical subjects

J Lu

Publications and source records attributed to J Lu.

At least 307 records · Page 17Linked to original sources

PubMed1999

Cartilage and synovium of the peroneocuboid joint: an anatomic and histological study.

The surface area, thickness, and composition of the articular cartilage of the peroneocuboid articulation and the location of the synovium were investigated in 15 cadaver foot specimens. The articulations of the medial side of the peroneus longus tendon and lateral side of the cuboid were covered with fibrous and hyaline cartilages, respectively. On the lateral tuberosity of the cuboid, there is a facet that has 79.37+/-20.24 mm2 articular cartilage area with an oval shape to conform to that of the articular surface of the peroneus longus tendon (articular cartilage area, 67.35+/-28.53 mm2) with which it articulates. The mean thickness of the articular cartilage of the peroneus longus tendon and cuboid was 0.34+/-0.08 and 0.52+/-0.07 mm, respectively. The peroneocuboid joint has its own joint capsule. The synovial cavity does not communicate with the sheath of the peroneus longus tendon. Synovial membranes were attached to the margins of the articular surfaces of the cuboid immediately peripheral to the cartilage region.

Adult↗

PubMed1999

Radiographic evaluation of the calcaneocuboid joint: a cadaver study.

Eighteen cadaver feet were used for radiographic evaluation of the calcaneocuboid joint. The articular surface of the cuboid on all specimens was painted with a radiopaque material. Fractures and 1-mm step-off of the fractures were simulated in six specimens. The articular surface line and joint space could be visualized maximally on an oblique radiograph without overlapping structures. The oblique view is good for assessing the extent of the minor fracture-displacement, which is normally obscured by overlapping projections in dorsoplantar and lateral radiographs. If there is any doubt on the routine radiographs or any injury involving the calcaneocuboid joint, an oblique view of the foot should be performed. The early diagnosis and treatment of calcaneocuboid joint injuries may minimize development of posttraumatic degenerative arthritis.

Cadaver↗

PubMed1999

Mammary cancer promotion and MAPK activation associated with consumption of a corn oil-based high-fat diet.

Our earlier work has shown a selective promotional effect on the genesis of mammary carcinomas bearing a wild-type, but not mutant, Ha-ras codon 12 in a 1-methyl-1-nitrosourea (MNU)-induced carcinogenesis model by high-fat diets (Nutr Cancer 23, 283-290, 1995). To test the hypothesis that activation of the mitogen-activated protein kinase (MAPK) pathway is associated with this promotional effect, we compared the in vivo MAPK phosphorylation state of carcinomas from rats consuming a low-fat (5% corn oil, modified AIN-93G) with that from rats consuming a high-fat (25% corn oil) diet. Specifically, 21-day-old female Sprague-Dawley rats were given an intraperitoneal injection of MNU and one week later were randomized to the two diets for six weeks. The number of mammary carcinomas per rat was 68% greater in the high-fat group, and Ha-ras mutation was rare in this short-term model. The levels of the phosphorylated MAPK2 (active) and of proliferating cell nuclear antigen (PCNA) were significantly higher in carcinomas from the high-fat group, and the two parameters were substantially correlated (r2 = 0.43, p < 0.01). The expression level of c-Raf was fourfold higher in the high-fat group but was only modestly associated with MAPK activation (r2 = 0.35, p < 0.05). The levels of the total MAPK1 and MAPK2, guanosine triphosphatase-activating protein, Ha-Ras, and MAPK kinase did not change. These results suggest that an upregulation of c-Raf expression by high fat may in part account for the in vivo MAPK activation, which in turn may enhance cell proliferation and mammary carcinogenesis.

Animals↗

PubMed1999

A role for serum response factor in coronary smooth muscle differentiation from proepicardial cells.

Coronary artery smooth muscle (SM) cells originate from proepicardial cells that migrate over the surface of the heart, undergo epithelial to mesenchymal transformation and invade the subepicardial and cardiac matrix. Prior to contact with the heart, proepicardial cells exhibit no expression of smooth muscle markers including SMalphaactin, SM22alpha, calponin, SMgammaactin or SM-myosin heavy chain detectable by RT-PCR or by immunostaining. To identify factors required for coronary smooth muscle differentiation, we excised proepicardial cells from Hamburger-Hamilton stage-17 quail embryos and examined them ex vivo. Proepicardial cells initially formed an epithelial colony that was uniformly positive for cytokeratin, an epicardial marker. Transcripts for flk-1, Nkx 2.5, GATA4 or smooth muscle markers were undetectable, indicating an absence of endothelial, myocardial or preformed smooth muscle cells. By 24 hours, cytokeratin-positive cells became SMalphaactin-positive. Moreover, serum response factor, undetectable in freshly isolated proepicardial cells, became strongly expressed in virtually all epicardial cells. By 72 hours, a subset of epicardial cells exhibited a rearrangement of cytoskeletal actin, focal adhesion formation and acquisition of a motile phenotype. Coordinately with mesenchymal transformation, calponin, SM22alpha and SMgammaactin became expressed. By 5-10 days, SM-myosin heavy chain mRNA was found, by which time nearly all cells had become mesenchymal. RT-PCR showed that large increases in serum response factor expression coincide with smooth muscle differentiation in vitro. Two different dominant-negative serum response factor constructs prevented the appearance of calponin-, SM22alpha- and SMgammaactin-positive cells. By contrast, dominant-negative serum response factor did not block mesenchymal transformation nor significantly reduce the number of cytokeratin-positive cells. These results indicate that the stepwise differentiation of coronary smooth muscle cells from proepicardial cells requires transcriptionally active serum response factor.

Animals↗

PubMed1999

Induction of NADPH diaphorase/nitric oxide synthase in the spinal cord motor neurons of rats following a single and multiple non-penetrative blasts.

The present study has demonstrated the induction of nicotinamide adenine dinucleotide phosphate-diaphorase (NADPH-d) reactivity and nitric oxide synthase-like immunoreactivity (NOS-LI) in the ventral horn motoneurons of the spinal cord in rats subjected to a single or multiple underground, or a single surface blast. Both enzyme activities were first detected in some motoneurons in laminae VIII and IX of Rexed, 3 hours after the blast. Some NADPH-d and NOS-LI positive neurons were also distributed in laminae VI and VII. The number and intensity of the labelled cells appeared to increase progressively, peaking at 2-3 days after the blast but were drastically reduced thereafter, so that at 7 days after the blast only a few positive neurons were observed. In rats killed at 2 weeks and in longer surviving intervals, i.e. up to 1 month, NADPH-d/NOS reactivity in the ventral horn motor neurons had diminished. The functional significance of the transient expression of neuronal NADPH-d/NOS after the blasts remains uncertain, although from a speculative point of view, the induction of these enzymes probably would reflect an increased production of nitric oxide (NO). In view of the lack of atrophic changes in most, if not all, of motor neurons, it is suggested that the increased levels of NO production after the blast injury may be involved in a neuroprotective function.

Animals↗

PubMed1999

The vertebral artery: surgical anatomy.

Anterior cervical decompressive surgery is widely performed for spondylosis, herniated intervertebral disk, tumor, infection, and trauma in the subaxial cervical spine region. Laceration of the vertebral artery is the most challenging of surgical dilemmas during anterior cervical spine surgery, as gaining control of the massive hemorrhage from a ruptured vertebral artery is difficult and could possibly result in an uncertain neurologic morbidity. As such, the understanding the surgical anatomy of the vertebral artery is essential to prevent iatrogenic injuries.

Cervical Vertebrae↗

PubMed1999

A high-density integrated genetic linkage and radiation hybrid map of the laboratory rat.

The laboratory rat (Rattus norvegicus) is a key animal model for biomedical research. However, the genetic infrastructure required for connecting phenotype and genotype in the rat is currently incomplete. Here, we report the construction and integration of two genomic maps: a dense genetic linkage map of the rat and the first radiation hybrid (RH) map of the rat. The genetic map was constructed in two F2 intercrosses (SHRSP x BN and FHH x ACI), containing a total of 4736 simple sequence length polymorphism (SSLP) markers. Allele sizes for 4328 of the genetic markers were characterized in 48 of the most commonly used inbred strains. The RH map is a lod >/= 3 framework map, including 983 SSLPs, thereby allowing integration with markers on various genetic maps and with markers mapped on the RH panel. Together, the maps provide an integrated reference to >3000 genes and ESTs and >8500 genetic markers (5211 of our SSLPs and >3500 SSLPs developed by other groups). [Bihoreau et al. (1997); James and Tanigami, RHdb (http:www.ebi.ac.uk/RHdb/index.html); Wilder (http://www.nih.gov/niams/scientific/ratgbase); Serikawa et al. (1992); RATMAP server (http://ratmap.gen.gu.se)] RH maps (v. 2.0) have been posted on our web sites at http://goliath.ifrc.mcw.edu/LGR/index.html or http://curatools.curagen.com/ratmap. Both web sites provide an RH mapping server where investigators can localize their own RH vectors relative to this map. The raw data have been deposited in the RHdb database. Taken together, these maps provide the basic tools for rat genomics. The RH map provides the means to rapidly localize genetic markers, genes, and ESTs within the rat genome. These maps provide the basic tools for rat genomics. They will facilitate studies of multifactorial disease and functional genomics, allow construction of physical maps, and provide a scaffold for both directed and large-scale sequencing efforts and comparative genomics in this important experimental organism.

Alleles↗

PubMed1999

A parallel study on the effects in treatment of impotence by tonifying the kidney with and that without improving blood circulation.

141 cases of functional impotence of the kidney-deficiency type were treated by tonifying the kidney. On them, 103 cases at the same time were treated by improving blood circulation and the other 38 cases by the former only. As a result the total effective rate and the markedly effective rate in the former were 84.46% and 46.60% respectively; but in the latter, 60.55% and 13.15%. A significant difference was found in Ridit analysis (P < 0.05), indicating that method of tonifying the kidney with improving blood circulation is much better than by simply tonifying the kidney alone.

Adult↗

PubMed1999

[Measurement of serum tumor necrosis factor-alpha and interleukin-8 in children with low respiratory tract infection (LRTI) caused by Mycoplasma pneumonia].

OBJECTIVE: To investigate the immunopathological mechanism of LRTI caused by Mycoplasma pneumonia. METHODS: Serum tumor necrosis factor-alpha (TNF-alpha) and interleukin-8 (IL-8) from 30 patients with LRTI caused by Mycoplasma pneumonia, were measured with sequence saturated solution competitive radioimmunoassay and sandwich ELISA. RESULTS: The level of serum TNF-alpha and IL-8 of patients suffering from LRTI caused by Mycoplasma pneumonia were magnificantly higher than that of healthy children. Meanwhile, a positive relationship between serum TNF-alpha and IL-8 was noticed. CONCLUSION: TNF-alpha plays an important role in LRTI caused by Mycoplasma pneumonia, and serves the key factor to the elevation of IL-8.

Adolescent↗

PubMed1999

The impact of codon 54 variation in intestinal fatty acid binding protein gene on the pathogenesis of diabetes mellitus in Chinese.

OBJECTIVE: To investigate whether or not the intestinal fatty acid binding protein gene (FABP2)-Ala54Thr variation is related to non-insulin dependent diabetes mellitus (NIDDM), obesity, dyslipidemia and glucose stimulated insulin secretion (GSIS) in Chinese. METHODS: The FABP2-Ala54Thr variation was detected by PCR/Hhal digestion in 231 Chinese subjects (116 with normal glucose tolerance (NGT), 54 with impaired glucose tolerance (IGT) and 61 with NIDDM). Plasma glucose, insulin and C-peptide levels before and after 75 g glucose load as well as fasting lipid profile were determined. RESULTS: (1) The Ala54 and Thr54 allele frequencies in Chinese were 0.71 and 0.29 respectively; (2) The FABP2-Ala54Thr variation was neither associated with fasting and post-challenged plasma glucose levels nor with NIDDM; (3) This variation was neither associated with fasting lipid profile nor with obesity; (4) The IGT subjects with genotype Thr54(+) (Thr54 homozygotes and heterozygotes) had lower fasting, 2-hour and total C-peptide levels and smaller AUC representing lesser C-peptide secretion after glucose challenge than those with genotype Thr54(-) (Ala54 homozygotes) (P = 0.04, 0.03, 0.01 and 0.01 respectively). The serum insulin levels changed in the same tendency. CONCLUSIONS: The glucose stimulated insulin secretion (GSIS) reserve of islet beta-cells is more limited in subjects with FABP2-Thr54(+) genotype than in those with FABP2-Thr54(-) genotype. It suggests that FABP2-codon 54 variation might contribute to the insufficient insulin secretion in the development of NIDDM in Chinese.

Alanine↗

PubMed1999

[The mechanism of tumor necrosis factor-alpha (TNF-alpha) induced insulin resistance by variation in promoter region of TNF-alpha gene].

OBJECTIVE: To investigate the relationship between the G to A variant at the--308 bp of the promoter region of tumor necrosis factor-alpha gene (TNF-alpha-P) and the body adiposity, the insulin secretion and action, and the glucose and lipid levels in Chinese population. METHOD: 359 Chinese were genotyped for the TNF-alpha-P by using PCR/Nco I digestion. Fasting blood lipid profile and the levels of plasma glucose (PG), insulin (INS), c-peptide (CP) and the free fatty acids (FFA) at 0, 1/2, 1, 2 and 3 hours after glucose challenge were measured. RESULTS: Genotype frequencies of TNF-alpha-P were not associated with diabetes and obesity. The genotype frequency of the G/A heterozygotes was significantly increased in non-diabetic subgroups with less decreased levels of 2 h-FFA and AUC-FFA after glucose challenge (Fisher exact P = 0.002 and 0.041 respectively). The FFA levels in non-diabetics with G/A heterozygotes were higher than those with G/G homozygotes, especially in the comparisons of the 2 h and 3 h FFA levels after glucose challenge (P = 0.029 and 0.030 respectively). Similar tendency was also observed in diabetics. CONCLUSION: Circulation FFA level reflects the degree of lipolysis in adipose tissue. The difference in the degree of lipolysis led by the variant of the promoter region of TNF-alpha may be one of the mechanisms for the variation in the degree of insulin resistance in general population.

Adult↗

PubMed1999

Relationship between bone mineral density and polymorphism of the estrogen receptor gene in healthy postmenopausal women in China.

OBJECTIVE: To investigate the possible relationship between bone mineral density and polymorphism of the estrogen receptor (ER) gene in Shanghai healthy postmenopausal women. METHODS: 250 unrelated healthy postmenopausal women were selected for bone mineral density (BMD) determination by Dual energy X-ray absorptiometry (DEXA) and polymorphism of estrogen receptor gene analyses by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). RESULTS: Pvu II polymorphisms of ER gene was associated with low Troch BMD (P = 0.0153) while there was no significant relationship between Xba I polymorphism of ER gene and BMD at any of skeletal sites included in the present study, and the combination of Pvu II and Xba I polymorphisms of ER gene was significantly associated with both low Lumbar 2-4 (P = 0.0369) and Troch (P = 0.0384) BMD. Multiple stepwise regression analysis also indicated that two combined polymorphisms were correlated significantly with Lumbar 2-4 BMD (P = 0.0254) while this correlation was not revealed at any other skeletal sites. CONCLUSION: There is significant relationship between the polymorphism of ER gene and both Lumbar 2-4 BMD and Troch BMD. It is significant to explore the pathogenesis of osteoporosis and to prevent the development of osteoprosis by use of molecular genetics.

Absorptiometry, Photon↗

PubMed1999

[The relationship between hypoxic pulmonary hypertension and changes of HO-1 and its mRNA].

OBJECTIVE: To study the relationship of HO-1 and HPH. METHODS: The expression of HO-1 and HO-1 mRNA were observed in pulmonary vessles of rats using the technique of immunohistochemistry and hybridization in situ. The average value of integral light density of HO-1 in three different diameters of arteries was detected by means of the image analysor and considered as the relative content in pulmonary arteries. RESULTS: Hypoxia induced the expression of HO-1 and HO-1 mRNA and the relative content of HO-1 was significantly increased in pulmonary arteries corresponding with the period of hypoxia. CONCLUSIONS: In the condition of HPH, relative content of HO-1 increase obviously. It suggests that HO-1 plays certain role in development of HPH. The change of HO-1 mRNA expression is the basis of molecular change of HO-1.

Animals↗

PubMed1999

[Thyroid squamous-cell carcinoma showing thymus-like element (CASTLE): a report of eight cases].

OBJECTIVE: To report 8 cases of squamous-cell carcinoma showing thymus-like element (CASTLE) of the thyroid. METHODS: Clinical data and pathological sections were retrospectively reviewed. RESULTS: CASTLE of the thyroid differed from ordinary squamous-cell carcinoma (SCC) in that it not only presented typical squamous pattern of differentiation, but also admixed with thymic architecture, such as Hassall's corpuscles, lymphoepithelial-like structure and mature lymphocyte infiltration in the stroma. CASTLE of the thyroid and much better prognosis than that of the ordinary SCC of the thyroid with a median survival time of 10.5 year. Histogenesis of CASTLE was discussed. CONCLUSION: Thyroid CASTLE is of rare occurrence. It should be distinguished from SCC of thyroid in order to treat such patients adequately.

Adult↗

PubMed1999

[Preventive effect of radix Astragali on insulin resistance caused by tumor necrosis factor-alpha].

OBJECTIVE: To investigate the preventive effect of Radix Astragali (RA) on insulin resistance caused by tumor necrosis factor-alpha (TNF-alpha). METHODS: Normal rats were pretreated with RA or distilled water by intragastric infusion for one week. Glucose-insulin tolerance test was conducted in the rats 4 h after low dose TNF-alpha injection by caudal vein to estimate the change in insulin sensitivity. Meanwhile, the plasma glucagon, ACTH, blood lipid, and glycogen, triglyceride in tissue were also observed. RESULTS: Exogenous TNF-alpha could induce hyperinsulinemia in normal rats. K value in glucose-insulin tolerance test decreased, serum ACTH, glucagon, blood lipid increased, glycogen content in liver and red quadriceps muscles decreased, the liver triglyceride level increased in the TNF-alpha treated rats. RA could improve all the above-mentioned changes significantly except the blood lipid and triglyceride depots in liver. CONCLUSION: RA has obvious preventive effect on insulin resistance caused by TNF-alpha, it may be due to its action in decreasing insulin antagonistic hormones and increasing glycogen synthesis in tissue.

Animals↗

PubMed1999

[Association of Gln223Arg variant in leptin receptor gene with metabolic abnormalities and hypertension in type II diabetes mellitus in Shanghai "Han" population].

OBJECTIVE: To investigate the association of Gln223Arg variant in leptin receptor gene with metabolic abnormalities and hypertension in type II diabetes mellitus. METHODS: The genotypes of Gln223Arg variant in leptin receptor gene were determined by polymerase chain reaction-restriction fragment length polymorphisms (PCR-RFLP) assay in 359 unrelated subjects of Shanghai "Han" population (including 193 subjects with normal glucose tolerance and 166 type II diabetic patients). The clinical data were also analyzed. The parameters for regional adipose tissue distribution were measured by magnetic resonance imaging (MRI). RESULTS: Significant difference of genotype frequency of Gln223Arg variant in leptin receptor gene was observed between hypertensive and normotensive type II diabetic male patients (P = 0.008). "A" allele was associated with increased systolic blood pressure (P = 0.0026) and diastolic blood pressure (P = 0.0084) in type II diabetic male patients. Logistic regression analysis showed that this gene variant was an independent risk factor of type II diabetic male patients accompanied with hypertension (P = 0.0031), and it was associated with elevation of systolic blood pressure (P = 0.0054). The odds ratio of hypertension in type II diabetic male patients with "A" allele was 2.825 (95% CI 1.418, 5.627). CONCLUSION: Gln223Arg variant in leptin receptor gene is associated with hypertension in type II diabetic male patients, especially with elevation of systolic blood pressure.

Adult↗

PubMed1999

[The study on mechanical properties of laser welds of titanium in dentistry].

OBJECTIVE: To explore the mechanical properties of laser welds of titanium under different conditions. METHODS: Home-made Nd: YAG laser welding apparatus was used to weld TA2 and Ti-6Al-4V under different laser energy. Instron universal testing machine was adopted to measure the tensile load, 0.2% yield load and absolute elongation. The fractured surface was observed under SEM, Vickers microhardness values at welding area were measured and the mechanical properties after immersion in artificial saliva were detected. RESULTS: The mechanical strength of laser welds were related with material, voltage and the combination of them. At 700V-750V, there was no significant difference between tensile load of TA2 laser welds and that of the original material. For Ti-6Al-4V, At 750V. The mechanical strength of laser welds before and after immersion in artificial saliva made no statistic difference. CONCLUSION: It is suggested that the heat-affected zone of laser welding might be small and the corrosion resistance in artificial saliva might be high. The mechanical strength of titanium laser weld might meet the clinical demands at 19-20J/P.

Corrosion↗

PubMed1999

[Development of air microbe sampler with micropore filter membrane].

Dual head air microbe sampler with a large flow capacity of 100 liters per minute was manufactured. The sampler possesses simple structures, light weight, convenient operation and higher sampling efficiency, equal to 77%-96% of the grade six Anderson sampler. Sampling time is a main factor affecting sampling efficiency. This device is suitable for the determination of degree of biological clean air in clean environment and the detection of the pathogenic microbes in ward and public places and also microbes in ordinary environment.

Air Microbiology↗