Search PubMed⌕ Search

Biomedical subjects

Z Lin

Publications and source records attributed to Z Lin.

At least 271 records · Page 15Linked to original sources
PubMed1996

Typing of verotoxins by DNA colony hybridization with poly- and oligonucleotide probes, a bead-enzyme-linked immunosorbent assay, and polymerase chain reaction.

To identify the type of Verotoxins (VT) produced by Verocytotoxin-producing Escherichia coli (VTEC), a sensitive bead-enzyme-linked immunosorbent assay and polymerase chain reaction with common and specific primers to various VTs (VT1, VT2, VT2vha, VT2vhb, and VT2vp1) were developed. Together with colony hybridization tests with oligo- and polynucleotide probes, these methods were applied to VTEC isolates to type the VT produced. The toxin types of 26 of 37 strains were identified, but the reaction profiles in assays of the remaining 11 strains suggested the existence of new VT2 variants. The application of these identification procedures may be useful as a tool for clinical and epidemiological studies of VTEC infection.

Animals↗
PubMed1996

Advances in time-frequency analysis of biomedical signals.

The frequency content of many biomedical signals can change rapidly with time. Conventional Fourier spectral analysis techniques are insufficient for analyzing the time-varying spectral content of these signals. By mapping a one-dimensional function of time (or frequency), the time-frequency representation can localize the signal energy in both the time and frequency directions. It has been shown that many biomedical signal problems may benefit from time-frequency analysis. The objective of this paper is to review the advances in time-frequency analysis of biomedical signals. Relevant theoretical methodologies and practical considerations are introduced, and five application areas are reviewed: electroencephalography (EEG), electrocardiography, phonocardiography, electrogastrography, and electromyography.

Algorithms↗
PubMed1996

[Experimental study on "three-dimensional" culture of scar-derived fibroblasts].

Based on the monolayer cell culture system, we resuspended the scar-derived fibroblasts in a solution of polymerizing collagen to develop a "three-dimensional" cell culture system. In this system, cells, extracellular matrices and various modulating factors were associated to form an organic entity, in which the fibroblasts express their biologic characteristics similar to that in living body. With the three-dimensional system, we could study not only the morphology, proliferation and metabolism of fibroblasts, but also their cytophysiology, such as the role on connective tissue contraction. We recommend this culture system as a better model in the research of wound healing and scar formation.

Adolescent↗
PubMed1996

[Experimental study on antibacterial activity of subdermal vascular network island skin flap].

A comparison study was carried out on the antibacterial activity between two kinds of pig buttock flaps: the conventional island skin flap and the subdermal vascular network island skin flap which was created by thinning the distal half of a conventional island flap, preserving its subdermal vascular network. Antibacterial activity was evaluated by bacterial counts, phagocytic index and intracellular bacterial killing ratio of leukocytes, skin temperature, laser Doppler, ink perfusion, microangiography and transparent specimen technique. The results indicated that antibacterial activity of the subdermal vascular network island skin flap was much lower than that of the conventional island skin flap. The reduced blood supply and decreased leukocyte function were responsible for the low antibacterial activity after the conventional island flap was thinned.

Animals↗
PubMed1996

[Death due to cold of a 63-year-old male associated with hepatocellular carcinoma--bibliographic consideration on alcohol metabolism of the patients with liver dysfunction].

In the early morning of late December, a 63-year-old man was found dead in front of his apartment house. At medico-legal autopsy, subcutaneous hemorrhages of the occipital region and linear fractures of the occipital bone was observed, but there was no cerebral contusion leading him to death. Many white tumors, ranging from 0.5 to 2.0 cm in diameter, were observed in the liver. On sections of the liver, hepatic parenchyma was found entirely occupied by the tumors, which were histopathologically diagnosed as moderately- or well-differentiated hepatocellular carcinoma. Alcohol concentrations of the mixed intracardiac blood and the urine were determined to be 1.9 and 3.6 mg/ml, respectively. Through the police investigation, it became clarified that the male had been sleeping in front of his apartment house about at 10:30 p.m. on the day before he was found dead. The cause of his death was, therefore, considered due to cold, and the authors gave a bibliographic consideration on blood and urine alcohol concentrations and alcohol metabolism of a patient with liver dysfunction due to hepatocellular carcinoma.

Alcohol Drinking↗
PubMed1996

[Sinus venosus atrial septal defect: report of two cases with successful repair by the Vargas' procedure].

Two cases of sinus venosus atrial septal defect with partial anomalous of right upper pulmonary venous drainage into superior vena cava treated by the Vargas' procedure were reported. These patients were 5 and 6 years old. Post operative courses were uneventful, and results of postoperative hemodynamic and clinical evaluation were encouraging. The Vargas' procedure is useful method for a reconstraction of the anomaly in childhood because of use of the autologus tissues. Though long-term fate of this procedure is still uncertain. Then, we consider that a long-term follow up is necessary.

Cardiac Surgical Procedures↗
PubMed1996

Genotyping of ABO blood group system by PCR and RFLP on mummies discovered at Taklamakan desert in 1912.

ABO genotyping was carried out using polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP) method on the dried remains of nine human mummies which had been discovered at Taklamakan desert in 1912. In all the nine mummies, ABO genotype could be determined as BO type, and ABO phenotype of the eight mummies with hair specimen could be revealed as B type using absorption-elution method. These results mean that ABO phenotype estimated from its genotype by PCR-RFLP was consistent with that by absorption-elution method in all of the eight cases examined. And in the other one child mummy, ABO phenotype could not be examined because of no hair specimen. Although it is impossible to assess the allele frequency of ABO blood group system in the populations having lived in Gao Chang at that time, the present study shows a possibility of ABO genotyping from ancient human remains.

ABO Blood-Group System↗
PubMed1996

[Smooth intramural and kink-resistant polyester vascular prosthesis].

OBJECTIVE: To study the healing effect, neointimal formation and patency rate of smooth intramural and kink-resistant polyester vascular prosthesis. METHODS: Experimental implantations of the smooth intramural and kink-resistant polyester vascular prosthesis of internal diameters of 0.6-1. Ocm were performed in segments of abdominal aorta and thoracic descending aorta. RESULTS: The patency rate was 100% in both abdominal aortic implantations and thoracic descending aortic implantations after postoperative observation for 425 days, while the total patency rate was only 70% in the crimped controls. The thickness of the neointimal linings of both implantation groups was determined, smooth intramural, kink-resistant polyester vascular prostheses were significantly thinner than that using crimped polyester vascular grafts (P < 0.001). CONCLUSION: Our study proves the feasibility of using smooth intramural and kink-resistant polyester vascular prosthesis to substitute small arteries with an internal diameter of 0.6-1. Ocm.

Animals↗
PubMed1996

Crystal structure determination of basic phospholipase A2 from venom of Agkistrodon halys pallas by molecular replacement method.

Basic phospholipase A2 (BPLA2) from the venom of Agkistrodon halys pallas has a strong ability to hemolyze erythrocytes. The asymmetrical unit of P2(1)2(1)2(1) crystal of BPLA2 contains two molecules. Self-rotation function was used to study the orientation relationship of these two molecules. Cross-rotation and translation functions were then used to determine the orientations and positions of the two molecules in the unit cell. The model building and preliminary structure refinement were carried out. The result shows that the two molecules in the asymmetrical unit of orthorhombic crystal are related by a non-crystallographic 2-fold symmetry axis.

Agkistrodon↗
PubMed1995

Sex determination by polymerase chain reaction on mummies discovered at Taklamakan desert in 1912.

Sex determination was performed by the polymerase chain reaction (PCR) on eight adult mummies and one child mummy which were discovered at Taklamakan desert in 1912 and now belong to the Lüshun Museum in China. Archaeologically, these mummies were humans living in the seventh century, that is, more than 1300 years ago. Putative sex determination was performed based on external morphology for six of the eight adults, but it was impossible for the other two adults and one child mummy due to marked destruction on the external morphology. Hair, muscle and skin samples were then collected from each adult mummy, and skin and rib samples from the child mummy. Forty PCR cycles were performed as follows: denaturation at 94 degrees C for 40 s, annealing at 55 degrees C for 30 s and extension at 72 degrees C for 1 min. The primer and PCR reaction mixture were prepared according to the report by Witt and Erickson (M. Witt and R. P. Erikson, A rapid method for detection of Y-chromosomal DNA from dried blood specimens by the polymerase chain reaction. Hum. Genet., 82 (1989) 271-274)). Two different pairs of primer were used. One was X1, X2 (X1: 5'-AATCATCAAATGGAGATTTG-3'; X2: 5'-GTTCAGCTCTGTGAGTGAAA-3') to flanking the 170 bp fragment of the alphoid repeats on the human X chromosome, and the other was Y11, Y22 (Y11: 5'-ATGATAGAAACGGAAATATG-3'; Y22: 5'-AGTAGAATGCAAAGGGCTC-3') to flanking the 130 bp fragment of the alphoid repeats on the human Y chromosome. Extracted DNA solutions from mummy samples was purified using a spin column (T. Yoshii, K. Tamura, T. Taniguchi, K. Akiyama and I. Ishiyama, Water-soluble eumelanin as a PCR-inhibitor and a simple method for its removal. Jpn. J. Legal Med., 47 (1993) 323-329 (in Japanese with English abstract) for removing PCR-inhibitors, and bovine serum albumin (BSA) was employed to inhibit the remaining impurities even after the purification with the column. In six adult cases where the putative sex was determined from external morphology, the sex in five cases was consistent with that by PCR using hair, muscle, and skin samples, but the other one was inconsistent. In two adult cases where sex estimation was externally impossible, the sex was determined to be male because both X-specific and Y-specific bands were clearly detected. The child mummy was definitely male. This study shows that the sex determination was possible by the PCR method even with very ancient human samples > 1300 years old, that spin column was useful for removing impurities in the DNA solution from ancient human samples and that the BSA of optimum concentration suppressed the action of the PCR-inhibitory factors.

Adult↗
PubMed1995

Endogenous synthesis of galactose in normal men and patients with hereditary galactosaemia.

Despite restricted ingestion of lactose, patients with galactose-1-phosphate uridyltransferase deficiency have raised concentrations of galactose metabolites in blood and urine. Endogenous production of galactose may underlie this phenomenon. Using isotopically labelled galactose in a continuous intravenous infusion, we employed the steady-state flux method to calculate endogenous galactose production rate in three normal men and three patients with classic galactosaemia. We found that galactosaemic patients and normal subjects synthesise gram quantities of galactose per day. The rate of synthesis ranged from 0.53-1.05 mg/kg per h. Endogenous production of galactose may be an important factor in the pathogenesis of the complications of the brain and ovary, and could explain the persistent elevation of galactose metabolites in patients despite dietary restriction of galactose.

Adult↗