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Biomedical subjects

Z Ren

Publications and source records attributed to Z Ren.

At least 73 records · Page 4Linked to original sources
PubMed1997

Characteristic of facial muscle and efferent nerve on physiology and anatomy.

OBJECTIVE: To study the specialty of orbicularis oculi muscles, nerves and oris muscles, nerves and mechanism of difference of facial muscular injury in facial paralysis deeply. METHODS: The conductive velocity of the efferent nerves of orbicularis oculi and oris muscles of the health human beings and guinea pigs is measured with electromyogram (EMG) apparatus. RESULTS: The conductive velocity of orbicularis oculi nerve is quicker and oris muscles are controlled by facial nerves on both sides. Measuring the threshold of Strength-Duration (S-D) curves of the motor point of orbicularis oculi and oris muscles shows the threshold of the former is lower. Measuring the diameter of orbicularis oculi and oris nerve fibers on the guinea pigs and rabbits shows the diameter of orbicularis oculi nerve fiber is bigger. The area of secondary synapse space of orbicularis oculi motor end plate is larger than that of oris under scanning electron microscope. CONCLUSIONS: Orbicularis oculi muscles, orbicularis oculi nerves and oris muscles, oris nerves all have their own characteristic on physiology and anatomy. It elucidated the mechanism that orbicularis oculi muscle is easy to be injured.

Action Potentials↗
PubMed1997

[Physical analysis on living tissues' thermal injury process].

In the light of solid mechanics as well as thermal physics, the physical factors causing thermal injury are correlated and a new thermomechanical model is established to quantitatively describe the injury process in living tissues under heat striking. The three-stage mode of thermal injury to living tissue is interpreted. The paper reflects our preliminary effort to further study this clinical phenomenon in point of micro mechanics and thermal science. It is of significance in revealing the mechanisms of subcutaneous bubble formation, development as well as tissue's thermal mechanical disruption.

Biophysical Phenomena↗
PubMed1997

[Preparation of no-sugar huazhen granules].

This article introduces the preperation, especially its technologies of spraying, drying and making grain of no-sugar Huazhen Granules (composed of Flos lonicerae, Radix Bupleuri, etc.). Ideal grain can be obtained, the capacity of taking can be reduced greatly.

Desiccation↗
PubMed1997

[Establishment of semi-nested polymerase chain reaction for detecting Coxsackie B virus RNA and the application in clinical diagnosis of viral myocarditis].

The aim of this study was to determine the applicability of the polymerase chain reaction (PCR) technique for the detection of CBV RNA and for routine diagnostic use in clinics. To this end, three oligomeric regions of great homology among the CBVs were selected from the conserved 5'-noncoding region of the CBV genome, and were designated as a set of primers and probe. Semi-nested CBV PCR assay was established. The sensitivity of the method is at 0.1 TCID50 in diluted virus stocks, and this method doesn't react with other related viruses. After the optimum reaction system was determined, the technique was then used in clinical samples. In patients with myocarditis, 62 of 111 serum samples were positive by PCR. The CSF samples from patients with meningitis were also tested, and the positive result was found in 7 out of 20 (35%) specimens. Using the same 111 samples, the PCR technique was compared with the ELISA. The detection rates of the two methods for CBV were 56% and 45%, respectively, with a coincident rate of 77%.

Enterovirus B, Human↗
PubMed1997

Success against lymphatic filariasis.

A campaign against lymphatic filariasis began in China's Shandong Province during 1956. Epidemiological surveillance since 1984 indicates that the transmission of infection has been interrupted. The factors accounting for this are discussed and the continuing challenges presented by the disease are outlined.

Animals↗
PubMed1997

[The relationship between histologic grading of malignancy and regional lymph node metastasis in squamous cell carcinoma of larynx].

Forty cases of squamous cell carcinoma of larynx have been studied by using five factors scale in order to investigate the relation between histologic grading of malignancy and regional lymph node metastasis. The results show that high degree malignancy tumor (which gets more than ten points) and diffusly invased tumor have a significantly higher proportion of regional lymph node metastasis than others. There was no relation between histologic grading of malignancy and T categories. It indicated that histologic grading of malignancy may be a good help in predicting patient evolution.

Carcinoma, Squamous Cell↗
PubMed1996

Photolysis of the carbon monoxide complex of myoglobin: nanosecond time-resolved crystallography.

The biological activity of macromolecules is accompanied by rapid structural changes. The photosensitivity of the carbon monoxide complex of myoglobin was used at the European Synchrotron Radiation Facility to obtain pulsed, Laue x-ray diffraction data with nanosecond time resolution during the process of heme and protein relaxation after carbon monoxide photodissociation and during rebinding. These time-resolved experiments reveal the structures of myoglobin photoproducts, provide a structural foundation to spectroscopic results and molecular dynamics calculations, and demonstrate that time-resolved macromolecular crystallography can elucidate the structural bases of biochemical mechanisms on the nanosecond time scale.

Carbon Monoxide↗
PubMed1996

A technique for identifying the total space or temperature dependent thermal parameters (TITP) of biological materials in vivo.

A new algorithm for simultaneously identifying the space or temperature dependent conductivity K, blood perfusion rate Wb, metabolic rate qm, and thermal diffusibility alpha in Pennes' equation is postulated. The obtained over determined equations are solved by way of Householder's transformation. The validity of the method is tested through an example.

Algorithms↗
PubMed1996

Cloning of a DNA fragment encoding a heme-repressible hemoglobin-binding outer membrane protein from Haemophilus influenzae.

Haemophilus influenzae is able to use hemoglobin as a sole source of heme, and heme-repressible hemoglobin binding to the cell surface has been demonstrated. Using an affinity purification methodology, a hemoglobin-binding protein of approximately 120 kDa was isolated from H. influenzae type b strain HI689 grown in heme-restricted but not in heme-replete conditions. The isolated protein was subjected to N-terminal amino acid sequencing, and the derived amino acid sequence was used to design corresponding oligonucleotides. The oligonucleotides were used to probe a Southern blot of EcoRI-digested HI689 genomic DNA. A hybridizing band of approximately 4.2 kb was successfully cloned into pUC19. Using a 1.9-kb internal BglII fragment of the 4.2-kb clone as a probe, hybridization was seen in both typeable and nontypeable H. influenzae but not in other bacterial species tested. Following partial nucleotide sequencing of the 4.2-kb insert, a putative open reading frame was subcloned into an expression vector. The host Escherichia coli strain in which the cloned fragment was expressed bound biotinylated human hemoglobin, whereas binding of hemoglobin was not detected in E. coli with the vector alone. In conclusion, we hypothesize that the DNA fragment encoding an approximately 120-kDa heme-repressible hemoglobin-binding protein mediates one step in the acquisition of hemoglobin by H. influenzae in vivo.

Amino Acid Sequence↗
PubMed1996

[A study of the variation of the (AT)xTy motif-530bp 5' to the beta-globin gene in the Chinese population].

The repeated purine-pyrimidine motif (AT)xTy at the region -530bp 5' to the beta-globin gene is regarded as the binding site for BP1, a transcriptionally repressive nuclear protein. In present study, the rearrangement patterns of the -530 motif in the Chinese population, including 43 patients with various hemoglobinopathies and part of their relatives (34), as well as 20 hematologically normal individuals, were investigated with the method of ds-DNA cycle sequencing. The results showed that the -530 motif in Chinese people had three major variation types-(AT)8T5, (AT)7T7 and (AT)9T5. Besides, a novel rearrangement type, (AT)10T3, was found in a hematologically normal family. Furthermore, the analysis of haplotype between the beta-globin structural loci and the -530 motif rearrangement indicated that linkage disequilibrium existed between three mutant beta-globin genes (i.e., IVS-II-654(C-->T), CD41-42(-4bp) and HbE), and three -530 motif rearrangement types (i.e., (AT)8T5, (AT)7T7 and (AT)9T5)7 respectively.

Asian People↗
PubMed1996

[A study on transmission of bancroftian filariasis in Tancheng county, South Shandong province].

A longitudinal study was conducted to explore transmission dynamics and epidemic trend of bancroftian filariasis in Huayuan Village, Shengli Township, Tancheng County, Shandong Province, a previous highly endemic area of it, from 1984, the fifth year after its preliminary eradication, to 1993, without any control measures being taken. Results showed proportions of residents with microfilaremia decreased to 0.12% in 1993 from 0.56% before the study. Eight of the nine microfilaria carriers before the study became negative spontaneously. Six new microfilaria carriers were detected during the study period, but five of them converted negative in three or four years. Negative conversion rate of blood IgG4 in microfilaremia cases was 88.89% by the end of the study. Natural infection rate in mosquitoes dropped year by year, with 0.21%, 0.19% and 0.06% for 1984, 1985 and 1986, respectively, and no filarial larvae was found in them in 1993 and natural transmission potential dropped from 3.47 to zero. It suggested the threshold for transmission of filariasis was not reached and the transmission was close to the end, with the rates of mosquito biting of 24.1-52.5 and 13.5-21.0 times per person, per night, for those using or non-using mosquito net, respectively.

Animals↗
PubMed1996

[The structure and type of neuroglia in human eye lamina cribrosa].

OBJECTIVE: To investigate the morpho-structure of neuroglia in the lamina cribrosa of human eyes, its cell type, physiological characteristics and role in the pathological process of optic nerve damage. METHODS: Histochemical and immunocytochemical staining, and transmission electron microscopic techniques were uses. RESULTS: The neuroglial tissue is distributed in the interspaces between the laminar sheets, on the internal wall of scleral canal and in optic nerve fiber bundles. Its cell is of fibrillary neuroglial astrocyte type. CONCLUSION: The fibrillary neuroglial astrocytes constitute a spatial net-work like architecture within the lamina cribrosa, provide mechanical support for optic nerve fibers as their main function and have higher resistance to pressure insults than optic nerve fibers.

Astrocytes↗