Biomedical subjects

Z Ma

Publications and source records attributed to Z Ma.

At least 127 records · Page 7Linked to original sources

PubMed1999

Phylogenetic analysis of Ureaplasma urealyticum--support for the establishment of a new species, Ureaplasma parvum.

In this study, the phylogenetic relationships between the two biovars and 14 serovars of Ureaplasma urealyticum were studied using the sequences of four different genes or genetic regions, namely: 16S rRNA genes; 16S-23S rRNA gene spacer regions; urease gene subunits ureA, ureB, partial ureC and adjoining regions upstream of ureA, ureA-ureB spacer and ureB-ureC spacer; the 5'-ends of the multiple-banded antigen (MBA) genes. U. urealyticum genotypes, based on all four genomic sequences, could be clearly separated into two clusters corresponding with currently recognized biovars 1 and 2. Sequences were generally conserved within each biovar. However, there was heterogeneity within the 5'-end regions of the MBA genes of the four serovars of biovar 1; the sequence of serovar 3 was identical with the previously published sequence and differed by only three bases from that of serovar 14; but there were significant differences between the sequences of serovars 3 and 14 and those of serovars 1 and 6. Based on the phylogenetic analysis, support is given to previous recommendations that the two biovars of U. urealyticum be classified as distinct species, namely U. parvum and U. urealyticum for biovars 1 and 2, respectively. In the future, the relationship between the new species and clinical manifestations of ureaplasma infections should be studied.

5' Untranslated Regions↗

PubMed1999

Immunoglobulin concentrations and antigen-specific antibody levels in cervicovaginal lavages of rhesus macaques are influenced by the stage of the menstrual cycle.

The levels of antigen-specific antibodies (Abs) and immunoglobulins in the cervical mucus of women vary with the menstrual cycle; the highest levels occur during menses, and the lowest occur during the periovulatory period. The rhesus macaque is a widely used animal model of female genital tract immunity. We sought to determine whether rhesus macaques have a cyclical pattern of changing cervicovaginal Ab and immunoglobulin levels that is similar to that of the human female. This study examined the relationship of the stages of the menstrual cycle to genital mucosal and systemic immunoglobulin concentrations and Ab levels in rhesus macaques. In all seven rhesus macaques studied, the immunoglobulins G and A and some antibodies in cervicovaginal lavages varied with the stages of the menstrual cycle, and in many cases this variation reached the level of statistical significance. In a pattern similar to that of women, the highest levels of Abs and immunoglobulins occurred during menses, and the lowest levels occurred around the time of ovulation. However, the Ab and immunoglobulin levels in serum and rectal lavages did not change with the menstrual cycle stage. The results of this study are consistent with the hypothesis that the ovarian hormones that drive the menstrual cycle influence genital tract immunity in female primates.

Animals↗

PubMed1999

Cloning of a full length cDNA encoding canine Interleukin-4.

Primer designed on the basis of the conserved transcription start point (tsp) region of human and bovine gene transcripts, encoding the Interleukin-4 (IL-4), and subsequently the gene specific primer and an adaptor primer pair, was successfully used, to generate the full-length complementary DNA (cDNA) sequence coding for canine IL-4 (cIL-4), from pokeweed mitogen stimulated canine peripheral blood lymphocytes. The full-length cIL-4 contains an open reading frame of 399 nucleotides (nt), with a 5' ends of 66 base pairs (bp) and 3' ends of 125 bp. The nucleotide sequence contains six possible Asn-X-Thr or Asn-X-Ser linked glycosylation sites. Five sequence motifs of TATT or ATTTA, responsible for the regulation of gene expression, are found in the 3' untranslated region.

Amino Acid Sequence↗

PubMed1999

Man-made mineral fibers induce apoptosis of human peripheral blood mononuclear cells similarly to chrysotile B.

The aim of this study was to investigate whether man-made mineral fibers (MMMF) induce apoptosis of human peripheral blood mononuclear cells (PBMC), as we recently demonstrated for chrysotile B. In vitro cultivation of PBMC with various MMMF as well as chrysotile B clearly produced apoptotic cells. The alteration of the expression for apoptosis related genes at the mRNA level during in vitro cultures of PBMC with various MMMF revealed upregulation of Flice and Apaf-1 genes and down regulation of TNF receptor 1 and Bid genes. These results indicate that MMMF induce apoptosis of PBMC in a similar manner to chrysotile B. However, the process may be mediated not only by the Fas-related apoptotic pathway but also a mitochondrial pathway. Thus, one should be aware that respiratory and immunological abnormalities may occur in workers who are exposed to MMMFs.

Adult↗

PubMed1999

[Study of morphologic effects of 4 Chinese herbs by bone histomorphometry in ovariectomized rats].

OBJECTIVE: To study the therapeutic effects of Chinese herbs Drynaria, Cynomorium, Epimedium and Chain Fern on osteoporotic ovariectomized (OVX) rat models. METHODS: 54 Wistar female rats at the age of 3 months were randomly divided into 2 groups: control groups and experimental group. The control group included: normal groups (N), shamed oprations group(S) and ovariectomized group (OVX) (10 in each group); The experimental group: group A (Drynaria), group B (Cynomorium), group C (Epimedium) and group D (Chain Fern) (6 in each group). Each of the experimental groups was fed separately with the 4 Chinese herbs (0.25 g/100 g B.W/day) respectively by mouth every day for 2 months. Double tetracycline labels were carried out on these animals before the sacrifice. Their left tibia was reserved for the preparation of bone specimen and was studied by bone histomorphometry. RESULTS: The percentage of trabecular volume in total bone volume (TV/TBV) decreased significantly in OVX rats as compared with shame group (P < 0.01). However, after treatment with Drynaria or Epimedium, TV/TBV increased significantly as compared with that before treatment (P < 0.05). The surface area of tetracycline label in Drynaria group lowered and osteoid percentage increased in Epimedium group. CONCLUSIONS: The 4 Chinese herbs have some therapeutic effects on osteoporotic rat models. Drynaria and Epimedium appeared to work better.

Animals↗

PubMed1999

Surgical treatment of hepatocellular carcinoma and related basic research with special reference to recurrence and metastasis.

OBJECTIVE: To summarize the progress of surgical treatment of hepatocellular carcinoma (HCC) and related basic research at the Liver Cancer Institute of Shanghai Medical University in the recent years, with special reference to recurrence and metastasis. METHODS: Published and unpublished update clinical and experimental data in the above-mentioned areas are summarized. RESULTS: Surgical resection has played an important role in improving prognosis of HCC, the 5-year survival were 63.4% for small HCC resection (n = 806), 39.6% for large HCC resection (n = 1061), 64.7% for cytoreduction (using hepatic artery cannulation and ligation) and sequential resection of initially unresectable HCC (n = 93), 56.0% for cytoreduction using transcatheter arterial chemoembolization (TACE) and followed by resection (n = 65), and 22.4% for hepatic resection with removal of tumor thrombi in portal vein (n = 103). Unfortunately, the 5-year recurrent rate after curative resection of HCC was up to 61.5%, which was mainly a result of intrahepatic "metastasis" and multicentric origin of HCC. Clinically, re-resection of subclinical recurrence yielded 56% of 5-year survival (n = 202); prevention of recurrence by transcatheter arterial chemoembolization (TACE) + Interferon, or LAK/IL-2 therapy have decreased 3-year recurrent rate from 33% to 11%-18%. In experimental aspect, metastatic human HCC model in nude mice (LCI-D20) and HCC cell line with metastatic potential (MHCC97) have been established; studies on HCC invasiveness in the molecular level revealed similar results that reported in other solid cancers, and small HCC showed slightly better biological characteristics as compared with large HCC; microvessel density (MVD) that reflecting angiogenesis adversely correlated with 5-year survival of small HCC; experimental interventions using antisense H-ras, bispecific antibody, BB94, as well as anti-angiogenic agents (TNP470, suramin, CAI, heparin, antisense VEGF, etc.) have been demonstrated to inhibit tumor growth and lung metastasis in nude mice model. CONCLUSIONS: Recurrence and metastasis are the major obstacle to further improve prognosis of HCC, studies should be conducted both in clinical and experimental aspects, "HCC invasiveness" will be the major target to be studied, particularly in the molecular level, and anti-angiogenesis will be one of the important approach.

Angiogenesis Inhibitors↗

PubMed1999

[Effect of cefodizime on cellular immunity in patients with lung cancer].

OBJECTIVE: To study the enhancing effect of cefodizime on cellular immunity of patients with lung cancer. METHODS: The parameters of cellular immunity in blood and pulmonary alveoli were investigated in 45 patients with lung cancer complicated with lower respiratory tract infection (LRTI) and 10 non-cancer patients with LRTI. Nitroblue tetrazolium (NBT) reaction of polymorphonuclear neutrophils (PMN), the percentage of natural killer (NK) cells, and that of CD4+ cells, ratio of CD4+/CD8+ in peripheral blood, OD value of alveolar macrophages phagocyting neutral red, and IL-1 beta (ng/L) in broncho-alveolar lavage flind (BALF) were determined. RESULTS: The parameters examined in cancer patients with LRTI were significantly improved after cefodizime treatment, approaching to those seen in non-cancer patients with LRTI. The therapeutic results were better in patients treated with cifodizime than in patients treated with ceftriaxonum. CONCLUSION: Cefodizime is a better choice of antibiotic for the treatment of lung cancer complicated with lower respiratory tract infection. Its enhancing effect on systemic and local immune functions plays a role.

Adult↗

PubMed1999

[Preoperative arterial infusion chemotherapy of colorectal carcinoma pathological and clinical effects].

OBJECTIVE: To investigate the pathological and clinical effects of preoperative selective intra-arterial infusion chemotherapy on colorectal carcinoma. METHODS: 30 patients with colorectal carcinoma underwent selective regional arterial angiography by Seldinger's method followed by intra-arterial infusion chemotherapy. RESULTS: changes of karyopyknosis, karyorrhexis, coagulation and necrosis of cytoplasm in cancer cells around vascular vessels were found in all cases. Interstitial edema, invasion of inflammatory cells, fibroelastosis around cancer cells, proliferous intima, thrombus and inflammation of vessels were also found at the same sites. CONCLUSIONS: Histological changes are significant after preoperative selective intra-arterial infusion chemotherapy for colorectal carcinoma. This therapy can relieve symptoms.

Adult↗

PubMed1999

[The relation between cord compression rate and the outcome of surgical treatment].

OBJECTIVE: To study the relation of compressive spinal cord changes in morphology with postoperative results. METHODS: 114 cases of operative patients were divided in to three groups: ossification of posterior longitudinal ligament (OPLL), cervical spondylotic myelopathy (CSM), and cervical intervertebral disc herination. The spinal cord plane and to the compressive ratio in the most heavily pressed position were measured according to the JOA record. RESULTS: The compressive ratio and the plane were not corelated with clinical history. The spinal cord plane was positively corelated with the recovery rate. CONCLUSIONS: The preoperative spinal cord plane in OPLL and CSM is mostly corelated with the recovery rate.

Aged↗

PubMed1999

[Allograft-prosthesis combination in limb salvage surgery].

OBJECTIVE: To study allograft-prosthesis combination in limb salvage and the rational of composite prosthesis. METHODS: Of 16 patients with bone tumors age from 19 to 60 years, 6 women 12 men, osteosarcoma was found in 4 patients, chondrosarcoma in 2, malignant giant cell tumor in 3, fibrosarcoma in 3, and other malignant bone tumor in 4. Allograft-prosthesis combination in included allograft proximal femurs with total hip arthroplasty (3 patients), allografts bipolar femoral head replacement (8), allografts with total knee arthroplasty prosthetic replacements (7). All patients received adjuvant therapy for tumor control. RESULTS: The length of follow-up ranged from 18 months to 5 years during which time 1 patients died, 3 survived as tumor-carriers, and 12 were disease free. All patients obtained better functional result in their extremities and had good quality of life. CONCLUSIONS: Both prosthetic replacement and allograft advantages, the use of large bone allografts with metallic prosthesis for the treatment of bone tumors near or involving joints can be applied with good results in selected patients having limb salvage surgery.

Adult↗

PubMed1999

[Expression and regulation of p16 in osteosarcoma].

OBJECTIVE: To study the expression and regulation of p16 and related factors in osteosarcoma. METHODS: The levels of p16 protein and related factors were explored by Western blot analysis in 12 cases of osteosarcoma tissues and in cells of different phases of osteosarcoma cell line OS732. The status of p16 protein in osteosarcoma cells was revealed by immunofluorescence analysis. RESULTS: p16 protein was detected in 10 of 12 osteosarcoma tissues. pRb was found in all of the specimens, but 8 of them were hyperphosphorylated. p16 protein was the least in G1 phase. Localized in cytoplasm during G1 phase, p16 protein gathered around nuclear envelope in S phase and entered the nucleus in G2 phase. CONCLUSIONS: The expression rate of p16 protein was 83.3% in osteosarcoma tissues. The expression of p16 protein was unable to inhibit the phosphorylation of pRb in most osteosarcomas; p16 protein was extremely low in G1 phase, presumably it was sufficient to inhibit the phosphorylation of pRb, causing abnormal proliferation of the cells.

Adolescent↗

PubMed1999

[Computer-aided 3-D reconstruction and measurement of optic canal and intracanalicular structures].

OBJECTIVE: To reconstruct the human optic canal and its inner structures, and to provide knowledge of this region in detail for optic nerve decompression and further understanding on the pathologic mechanisms of indirect optic nerve injury. METHODS: 6 optic canals and its inner structures were reconstructed by using a computer-aided 3-dimensional (3-D) reconstruction system. Quantitative measurement for the canal wall thickness, bony canal transverse area, optic nerve transverse area, dual sheath transverse area, subarachnoid space transverse area, and subarachnoid space volume were done by means of the computer morphometric analysis system. The detailed spatial relations among intracanalicular structures were also carefully identified on the 3-D models. RESULTS: The thinnest portion of the canal was the middle part of the medial wall (0.45 +/- 0.35)mm, and the narrowest space was in the middle part of the optic canal [the transverse area was (18.21 +/- 2.50) mm(2)]. The volume of subarachnoid space which can be considered the compensatory space for distention incurred by the hemorrhage, optic nerve edema, or hematoma was (21.16 +/- 4.31) mm(3). At the cranial opening, the middle part and orbital opening, its transverse area was (4.45 +/- 1.12) mm(2), (2.68 +/- 1.32) mm(2), (1.23 +/- 0.83) mm(2), respectively. CONCLUSIONS: In the middle part, the restraining of the bony canal on injured nerve may be the most powerful. Since the compensatory space was limited, even a tiny amount of blood or swelling of the nerve may cause optic compression. Because the compensatory space for distention gradually decreases from cranial end to orbital end, the middle part and the anterior part of the optic canal and dural sheath are critical in optic nerve decompression.

Humans↗

PubMed1999

[A pathological study on indirect optic nerve injury in rabbit eyes].

OBJECTIVE: To study the pathological changes after indirect optic nerve injury. METHODS: Animal models (72 rabbits, 144 eyes) for intracanalicular optic nerve injury was developed by keeping the optic canal intact. The pathological changes of optic nerve were observed under light microscope and transmission electron microscope and the number of myelinated axons was enumerated by computer-aided image analyzer. The data were analyzed by using variance of SAS software. RESULTS: The model contributed much valuable information regarding nerve edema, loss of myelin, myelin regeneration and changes of axons. The edematous area in the optic nerve injury was reduced (P < 0.01) by treating with prednisone. The counted number of myelinated fibers showed more in the group treated by prednisone than that in the group without treatment. CONCLUSIONS: Significant changes of optic nerve after indirect injury are edema, demyelination and the change of axon amount. The effects of prednisone on reducing these pathological changes are demonstrated in this study.

Animals↗

PubMed1999

[Preservation of hearing and facial nerve function after Gamma knife therapy for acoustic neurinomas].

Thirty-five patients with acoustic neurinomas were treated by Gamma knife from Sept. 1995 to Oct. 1997. Neuroimaging studies performed in 21 patients with more than 12 months showed that tumor size decreased in 9(43%) cases, unchanged in 11(51%) cases, and increased in 1(15%) case. The tumor growth control and regression rates were 95% and 43%, respectively. Some hearing was preserved in four patients (36%) who had hearing prior to Gamma knife treatment. There was new transient facial weakness in five patients(23%), and there was new trigeminal neuropathy after treatment in one patient (4.8%). These findings indicate that Gamma knife therapy is a safe and effective management for acoustic neurinomas, especially in preventing facial function and hearing.

Adolescent↗

PubMed1999

[Changes of neurobehavioral functions in workers exposed to manganese].

The aim of this study was to assess the neurotoxic effects associated with the level of airborne manganese in the work place. A cumulative exposure index(CEI) was calculated for each subject. The neurobehavioral test battery, in terms of choosing reaction time, finger tapping, digit symbol, stylus in hole, Benton visual retention and Santa Ana dexterity was applied in the study. The manganese exposed workers had slower motor and response speed, poorer visuomotor coordination and steadiness. There was a dose-response relationship tendency between the cumulative exposure index and the behavioral function. Hence the neurobehavioral test may be a sensitive method in detecting early changes in motor and cognitive function among manganese-exposed workers. The study also demonstrates that the cumulative exposure of manganese about 1 mg/m3 per year may induce subclinical signs of intoxication.

Adult↗

PubMed1999

[Production and identification of anti-paraoxon monoclonal antibodies].

Paraoxon (E600) was conjugated to bovine serum albumin(BSA) or tachypleus tridentatus hemocyanin (TTH) by diazotization. Two hybridoma cell lines secreting monoclonal antibodies(McAb) against paraoxon have been established by fusing mouse myeloma cells and splenocytes from Balb/c mice immunized with E600-BSA. The chromosomes of the hybridoma cell 2B10 were analyzed. The immunoglobulin of the McAb was classified. The affinity and specificity of this antibody were determined. The hybridoma cells have fairly reserved the antibody-producing capacity after continuously growing or stored in liquid nitrogen for 10 weeks.

Animals↗

PubMed1999

[Analysis of 2-acrylamido-2-methyl propane sulfonic acid by thin layer chromatography].

A method for the analysis of 2-acrylamido-2-methyl propane sulfonic acid(AMPS) by TLC is described. The plate was Silica GF254. We selected benzene/methanol as developing agent from several developing systems and fixed the best ratio: V(benzene):V(methanol) = 2:1. The experiment indicated that the Rf value of AMPS was 0.36 while that of AM(acrylamide), the main impurity in crude AMPS sample, was 0.64. The minimum detectable limit of AMPS was 5 micrograms and the developing time was about 25 minutes. Compared with ether/methanol and chloroform/methanol, benzene/methanol system has the advantages of more easily controlling its ratio, better repeatability and much rapid developing rate. This method may be helpful in the control of AMPS in quality.

Acrylamides↗

PubMed1999

[Purification and partial characterization of antagonistic proteins from Bacillus subtilis B034].

Bacillus subtilis B034, an antagonistic bacteria isolated from the phyllosphere of rice, strongly inhibits the growth of Xanthomonas oryzae pv. oryzae which causes the rice bacterial blight. Crude extract was obtained by precipitation of the cell-free culture of B034 with 70% saturated (NH4)2SO4. The suspension of the precipitate strongly inhibits Xanthomonas oryzae pv. o-ryzae, and it is thermostable, resistant to trypsin, partial sensitive to proteinase K, pronase E and chloroform. Its active pH range is wide, from 4.0 to more than 12.0, relative more stable in high pH. Two antagonistic peaks were obtained from the crude extract of B034 after Phenyl-Sepharose CL-4B, DEAE-Sephacel and FPLC Superdex 75 HR 10/30 column chromatography. One of these two peaks, named P2, was showed only single band with 50.3 kD and pI6.25 in SDS-PAGE and PAGE-IEF, respectively. The N-terminal partial sequence of protein P2 was analyzed.

Amino Acid Sequence↗