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Biomedical subjects

X Ma

Publications and source records attributed to X Ma.

At least 91 records · Page 5Linked to original sources
PubMed2001

Morphological differentiation of nerve fibers: central, peripheral, myelinated and unmyelinated.

We have developed a new technique for the morphological differentiation of various nerve fibers which is especially suitable for the morphometric study of nerve fibers of the human nervous system with the help of an image-analyzer. The knowledge from findings by this technique, which is based on several study methods, may be of importance in promoting further neuromorphologic studies and in properly understanding various aspects of neurological symptomatology and the aging process of the nervous system including nerve fibers.

Adult↗
PubMed2001

Morphometric analysis of the human tibial nerve and the ageing process.

We analysed numbers and sizes of the human tibial nerve branch innervating the soleus muscle. The material was taken from 13 cadavers aged from 67 to 98 years. A linear regression analysis disclosed a significant age-related decrease in the mean number per unit area and the mean transverse area of axons. Such decreases with age may indicate atrophy and loss of motoneurons. Our results could help in understanding the correlation between morphology and function during the ageing process.

Aged↗
PubMed2001

Development of the human gracilis nucleus: a morphometric evaluation.

The development of the human gracilis nucleus was studied on serial sections of the brain of 9 fetuses and neonates at 18-40 weeks of gestation, a two-month-old infant and a 63-year-old adult using a microscope with a drawing tube and an image-analyzing computer system. A morphometric evaluation revealed that the human gracilis nucleus, whose neurons were distinguished from glia from 18 weeks of gestation onward, showed a gradual development in terms of the columnar volume, neuronal size and number, and revealed two kinds of phenomenon: a normal process which occur in the development of the fetus, viz. natural cell death (also called apoptosis), and a phenomenon due to yet unknown causes regarding a discrepancy between the number of neurons and the neuropil index.

Apoptosis↗
PubMed2001

Immunohistochemical study of hepatic oval cells in human chronic viral hepatitis.

AIM: To detect immunohistochemically the presence of oval cells in chronic viral hepatitis with antibody against c-kit. METHODS: We detected oval cells in paraffin embedded liver sections of 3 normal controls and 26 liver samples from patients with chronic viral hepatitis, using immunohistochemistry with antibodies against c-kit, piclass glutathione S-transferase (pi-GST) and cytokeratins 19 (CK19). RESULTS: Oval cells were not observed in normal livers. In chronic viral hepatitis, hepatic oval cells were located predominantly in the periportal region and fibrosis septa,characterized by an ovoid nucleus, small size,and scant cytoplasm. Antibody against stem cell factor receptor, c-kit, had higher sensitivity and specificity than pi-GST and CK19. About 50%-70% of c-kit positive oval cells were stained positively for either pi-GST or CK19. CONCLUSION: Oval cells are frequently detected in human livers with chronic viral hepatitis, suggesting that oval cell proliferation is associated with the liver regeneration in this condition.

Adult↗
PubMed2001

Relationship between autoimmune hepatitis and HLA-DR4 and DRbeta allelic sequences in the third hypervariable region in Chinese.

AIM: To analyze the association of HLA-DRB1 with autoimmune hepatitis (AIH) in patients from China. METHODS: In 32 patients and 48 healthy controls, polymerase chain reaction amplification with sequence-specific primers (PCR-SSP) was performed to examine the association of certain alleles or polymorphic sequences of HLA-DRB1 with AIH. RESULTS: HLA-DRB1 typing by PCR-SSP showed that DR4 had a significantly increased frequency among patients with AIH versus healthy control (46.9% versus 20.8%; relative risk = 3.35, P=0.014). In subtypes of DR4, there was a trend of increase in the gene frequency of DRB1 0405 in patients with AIH versus healthy controls (21.9% vs 6.3%, P=0.04, but P(c) =0.08). In addition, a significant increase was found in the alleles frequency encoding QRRAA from the third hyperpolymorphic region of DR4 in the patients with AIH (86.7% of DR4 positive patients vs 40.0% in DR4 positive controls, P=0.016, P(c)=0.028, RR=9.75). CONCLUSION: AIH in Chinese is associated with HLA-DR4. There is a relationship between QRRAA sequence within the third hyperpolymorphic region of the DRB allele and AIH in Chinese.

Alleles↗
PubMed2001

[Cases-Control association study and transmission disequilibrium test of T102C polymorphism in 5HT2A and Tourette syndrome].

OBJECTIVE: To investigate whether T102C polymorphism in 5HT2A (serotonin receptor 2A) is associated with Tourette syndrome. METHODS: Both case-control association analysis and Transmission Disequilibrium Test(TDT), in addition to polymerase chain reaction and RFLP technique were used in 157 trios with Tourette syndrome (TS) and 120 controls. A semi-structured "Schedule for Tourette and other behavioral syndrome" was used in family history-collecting. Both the criteria of "Diagnostic and Statistical Manual of Mental Disorders"(DSM-IV) and that of Tourette syndrome association (TSA) were used in the diagnosis of Tourette syndrome and related disorders. RESULTS: The association between T102C polymorphism in 5HT2A and Tourette syndrome comorbided with obsessive compulsive disorder (OCD) was found by genotype-wise analysis (chi(2)=8.38,P=0.004) and allele-wise analysis (chi(2)=4.84,P=0.028), which was further confirmed by TDT analysis (chi(2)=5.12,P=0.02). No evidence of association or transmission disequilibrium between 102T/C polymorphism in 5HT2A and this disease in pure TS and total TS sample was found. CONCLUSION: 102T/C polymorphism in 5HT2A is exclusively associated with Tourette syndrome comorbided with DSM-IV OCD, which may constitute an independent subtype of Tourette syndrome.

Adolescent↗
PubMed2001

[Studies on neonatal screening, clinical and gene analysis for tetrahydrobiopterin deficiency in Southern Chinese].

OBJECTIVE: To find out the incidence of tetrahydrobiopterin deficiency(BH4D) among patients with hyperphenylalaninemia in Southern Chinese and evaluate the clinical outcome and gene mutations of tetrahydrobiopterin deficient patients. METHODS: Analyses of urinary neopterin(N) and biopterin(B) were done in 87 patients with hyperphenylalaninemia by high-performance liquid chromatography. The patients with BH4 deficiency and their parents were asked to undergo the gene mutation analysis and the patients were treated and followed up. RESULTS: Eleven cases of which the urinary N/B ratio was higher than 38 and B% lower than 5% were diagnosed as BH4 deficiency caused by 6-pyruvoyl-tetrahydropterin synthase(PTPS) deficiency. The incidence of BH4 deficiency among patients with hyperphenylalaninemia is 12% in Southern Chinese. PTPS gene mutations (P87S, N52S, D96N and G144R) were detected from 5 PTPS deficient families. The G144R mutation is a new mutation. The five PTPS-deficient patients were treated with synthetic BH4, neurotransmitter precursors L-dopa and 5-hydroxytryptophan. They had satisfactory physical and mental development after treatment, and 4 of them scored their IQ 70-80. CONCLUSION: The screening for BH4 deficiency should be carried out in all patients with hyperphenylalaninemia in order to minimize the misdiagnoses.

Biopterins↗
PubMed2001

[Herbal compound 861 inhibits NF-kappa B binding activity of hepatic stellate cells in vitro].

OBJECTIVE: To investigate the effect of Cpd 861 on nuclear factor-kappa B (NF-kappa B) binding activity of hepatic stellate cells (HSC) in vitro. METHODS: The study was carried out on the culture of hepatic stellate cell line, 5mg/ml of Cpd 861 was added and incubated for 48 hours. NF-kappa B binding activity was evaluated by electrophoretic mobility shift assays. IL-6 and sICAM-1 levels in the cultured supernatant were detected by ELISA. Cell apoptosis was detected by flow cytometry and TUNEL. RESULTS: Cpd 861 suppressed the binding activity of NF-kappa B in HSCs compared with the control group. Moreover, IL-6 and sICAM-1 levels in the cultured supernatant were decreased (P<0.05) and apoptosis rate of HSCs was increased after Cpd 861 incubation (P<0.01). CONCLUSIONS: The inhibitory effect on NF-kappa B binding activity might be part of the cellular mechanism of Cpd 861 to treat liver fibrosis.

Animals↗
PubMed2001

Whole genome amplification increases the efficiency and validity of buccal cell genotyping in pediatric populations.

The collection of buccal cells provides a noninvasive method for obtaining DNA for genetic studies. Here we report the results on buccal cell genotyping from our ongoing study of childhood leukemia in Northern California. We have collected buccal samples from children ranging in age from 4 months to 15 years using an interviewer- or nurse-administered protocol using a cytology brush. Initial results of the genotyping, including the glutathione S-transferase mu, glutathione S-transferase theta, NAD(P)H:quinone oxidoreductase, and methylenetetrahydrofolate reductase polymorphisms, were disappointing because many specimens contained little DNA, failed repeated attempts at PCR amplification, and produced unreliable results. Here we evaluate a solution to the problem that involves whole genome amplification using the improved primer extension preamplification methodology. Sixty cases of pediatric acute leukemia were studied; five PCR-based genotypes were attempted using buccal cell DNA and whole genome amplified (WGA) buccal DNA. Results were compared with genotyping results using DNA isolated from peripheral whole blood or bone marrow for each child. The standard buccal protocol failed to yield successful PCR reactions in 30-57% of specimens, whereas WGA-buccal was markedly more efficient (2-5% failed PCR). A success rate of 100% was achieved with one repeat test of the failed WGA-PCR reactions. Misclassification of genotype was common for the glutathione S-transferase theta marker using the standard buccal procedure. The WGA-buccal protocol, however, produced genotyping results fully concordant with the referent blood or bone marrow DNA results for all five loci. DNA yields were increased by WGA to allow for approximately 900 PCR reactions/brush. WGA is very useful for improving the efficiency and validity of PCR-based genotyping in pediatric populations.

Adolescent↗
PubMed2001

Focal arterial transgene expression after local gene delivery.

BACKGROUND: Gene therapy for the treatment of vascular disease is limited by a low transfection efficiency and/or undesired biological responses. OBJECTIVE: To determine the transfection efficiency of delivering a liposome/DNA complex into balloon-injured rabbit arteries systematically or using a local delivery catheter. METHODS: The cationic liposomes N-[1-(2,3-dioleoyloxy) propyl]-N,N,N-trimethylammonium methyl-sulphate and dioleoyl-phosphatidylethanolamine were mixed 1:1 (wt/wt) and combined with the plasmid pCMV-AP containing the human placental alkaline phosphatase (AP) reporter gene. Before initiating the in vivo experiments, the optimal ratio of liposome to DNA complex and the persistence of transgene expression were determined in cultured vascular smooth muscle cells (SMC). In vivo, a Dispatch catheter was used for local delivery of the liposome/DNA complex into rabbit iliac arteries that had been balloon injured five days previously. The contralateral iliac or renal artery was also balloon injured, and liposomes with normal saline were delivered as a negative control. For the systemic delivery group, the liposome/DNA complex was delivered through an ear vein. RESULTS: AP expression in transfected SMC persisted for 28 days in vitro, although the percentage of transfected cells declined with time (eg, at 24 h it was 27.3%+/-2.9%, at 28 days it was 0.4%+/-0.1%). SMC proliferation in vitro enhanced the transfection efficiency 12-fold. In vivo, local delivery resulted in low levels of transfection in arteries harvested one day postdelivery; however, six of seven arteries harvested three days postdelivery had multiple regions of focal transgene expression involving all three arterial layers. For the systemic delivery group, two of nine arteries expressed the transgene. No transgene expression was found in uninjured arteries in either the local or systemic delivery groups. However, with both local and systemic delivery, balloon-injured arteries that received liposomes and saline showed low levels of AP expression in either the neointima, media or adventitia, presumably due to systemic recirculation of the liposome/AP construct. CONCLUSIONS: Liposome-mediated gene transfection can be successfully performed to all vessel layers in vivo by using a local delivery catheter, and may provide a therapeutic opportunity for modulating atherosclerosis and restenosis. Unwanted transfection at a distance may occur with catheter-based local delivery and requires further refinement.

Analysis of Variance↗
PubMed2001

No mutations of SAP/SH2D1A/DSHP and perforin genes in patients with Epstein-Barr virus-associated hemophagocytic syndrome in Japan.

Recently, mutations of two genes, SAP/SH2D1A/DSHP and perforin genes, have been identified in two fatal inherited lymphoproliferative diseases, X-linked lymphoproliferative disease and familial hemophagocytic lymphohistiocytosis, respectively. Epstein-Barr virus (EBV)-associated hemophagocytic syndrome, a fulminant non-inherited T-cell lymphoproliferative disease, is relatively common in Japan and is extremely difficult to distinguish from X-linked lymphoproliferative disease and familial hemophagocytic lymphohistiocytosis, especially in sporadic cases, because of similarities in clinical and laboratory features. Mutation analysis was carried out of samples obtained from 14 patients with EBV-associated hemophagocytic syndrome by sequencing the genomic SAP/SH2D1A/DSHP and perforin genes. However, a specific mutation was not identified in either of the genes, suggesting that mutations of the SAP/SH2D1A/DSHP and perforin genes are not responsible for the pathogenesis of EBV-associated hemophagocytic syndrome in Japan.

Adolescent↗
PubMed2001

[Super heavy oil produced water treatment by surface flow constructed wetland].

This paper adopts a new economic technology of treating super heavy oil produced water using surface flow reed wetland system. The field test was conducted at the average filtration rate of 3.33 cm/d. The average influent concentrations per year of COD, Oil, BOD5, TN were 459.16 mg/L, 27.65 mg/L, 33.52 mg/L, 13.74 mg/L, and the average effluent concentrations per year of above indices were 77.21 mg/L, 1.42 mg/L, 3.90 mg/L, 1.60 mg/L, respectively. Its respective removal ratios of COD, Oil, BOD5, TN and pH were 83.18%, 94.86%, 88.37%, 88.36%, 7.87-7.77. Analyses showed that super heavy oil produced water had no obvious effect on soil and almost no effect on growth volume and quality of reeds. Results indicated that the surface flow reed wetland could provide an efficient economical, stable new means of treating super heavy oil produced water.

Fuel Oils↗
PubMed2001

[Expression of neural cell adhesion molecule in murine livers with experimental autoimmune hepatitis].

OBJECTIVE: To investigate the expression of neural cell adhesion molecule (NCAM) in murine livers with experimental autoimmune hepatitis (EAH) and its relationship with histological grades. METHODS: To induce the EAH model, the syngeneic S-100 antigen emulsified in complete Freud's adjuvant was injected intraperitoneally to C57Bl/6 at day 1 and day 7. The mice were sacrificed at day 7, 14, and 21 after the first immunization. The expression of NCAM was observed using histoimmunochemistry and RT-PCR. RESULTS: The expression of NCAM increased gradually with aggravation of lymphocyte infiltration and hepatocyte injury. The administration of prednisolone decreased the histological grade, and inhibited the expression of NCAM. There was a correlation between the expression of NCAM and histological grade (r=0.71, P<0.01). CONCLUSIONS: NCAM provides a traffic signal for infiltration of lymphocytes in the liver, hence induces the injury of hepatocytes.

Animals↗
PubMed2001

Vitamin D receptor gene polymorphism and bone mineral density in patients with type 2 diabetes mellitus.

OBJECTIVE: To explore the relationship between vitamin D receptor (VDR) gene polymorphisms and bone mineral density (BMD) in patients with type 2 diabetes mellitus (DM) and to better understand the pathogenesis of osteoporosis. METHODS: Ninety seven patients with type 2 DM were recruited for this study. BMD was measured by single photon absorptiometry at the lower one third of the nondominant radius and ulna. Polymorphisms of the VDR gene were analyzed by DNA amplification with polymerase chain reaction (PCR) and endonuclease digestion with Bsm I. RESULTS: The respective frequencies of VDR genotypes were BB 18.6%, Bb 27.8% and bb 53.6%. The Z scores of the three groups were -1.57 +/- -0.60, -1.45 +/- -0.67 and -1.41 +/- -0.81, respectively. Although the BMD of the Bb genotype DM patients was higher than that of BB genotype DM patients and lower than that of bb genotype DM patients, there were no significant differences. CONCLUSION: These findings suggest a small influence of VDR gene polymorphism on the BMD of patients with type 2 DM. Further study on the value of VDR genotypes in the pathogenesis of osteoporosis in diabetes mellitus is still needed.

Adult↗
PubMed2001

Effect of Salvia miltiorrhiza Bunge injection on anticardiolipin antibody production induced by beta2 glycoprotein.

AIM: To explore the therapeutic effect and the mechanism of Chinese herbs on antiphospholipid syndrome (APS) by observing the effect of Salvia miltiorrhiza Bunge injectio (SmBI) on anticardiolipin antibody (aCL) induced by beta2 glycoprotein I (beta2-GP I). METHODS: Sixty female mice randomly fell into 6 groups: group A, B, C, D was injected through abdominal cavity with different dosage of SmBI daily; after 14 d, group A, B, C, E was immunized with 150 microg of purified human beta2-GP I in complete Freund's adjuvant subcutaneously; group F as control. The titre of aCL were detected by enzyme linked immunosorbent assay; subsets of T cell were grouped by streptavidin-biotin complex technique; and the activity of IL-2 was measured by MTT chromatometry. RESULTS: (1) Compared with group E, the absorbance (A) of aCL in group A, B, and C was decreased (P < 0.05 or P < 0.01). By linear correlation, the dosage is negatively correlated with the A values of aCL in 1, 2, and 3 weeks (P < 0.01). (2) Compared with group E, TH/TS ratio was reduced in group A, B, and C (P < 0.05 or P < 0.01); there is no significant differences between group D and F (P>0.05). By linear correlation, the dosage is negatively correlated with TH/TS ratio (P < 0.01). (3) Compared with E, the activity of IL-2 in group B and C decreased significantly (P < 0.01). By linear correlation, there is negative correlation between dosage and IL-2 activity (P < 0.01). There is no significant difference between D and F (P > 0.05). (4) There is positive correlation between TH/TS ratio and IL-2 activity in different dilutions (P<0.01). CONCLUSION: The mechanism of suppressive effect of SmBI on aCL induced by beta2-GP I may be realized by resuming the elevated TH/TS ratio and IL-2 activity. The state that SmBI have no effect on normal mice indicates that SmBI has selective immunoregulative functive.

Adjuvants, Immunologic↗
PubMed2001

[An off site petroleum-contaminated soil bioremediation technology: soil compositing in windrow].

With off-site bioremediation technology, a soil contaminated by crude oil from Liaohe Oil Field was treated on a 20 x 10 m prepared bed. 8 composting windrow units were set, each measured 8 m in length, 2 m in width, and 0.35 m in height. The results showed that when the pollutant petroleum hydrocarbon(TPH) was within the range of 4.16-7.72 g.100 g-1 soil, the total degradation rate of TPH reached 45.19%-56.74% after 53 days operation, which indicated that a technological basis would be provided for the bioremediation of oil-contaminated soil.

Biodegradation, Environmental↗