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Biomedical subjects

Z Wei

Publications and source records attributed to Z Wei.

105 records · Page 6Linked to original sources
PubMed1993

Postischemic deterioration of sarcoplasmic reticulum: warm versus cold blood cardioplegia.

Impaired cardiac sarcoplasmic reticulum (SR) function, as evidenced by reduced SR Ca2+ uptake rate and decreased SR Ca(2+)-adenosine triphosphatase activity, has been found in postischemic "stunned" myocardium and in hearts subjected to hypothermic arrest. In this study, we compared the effects of retrograde continuous coronary sinus warm blood cardioplegia (WBC) and retrograde intermittent cold blood cardioplegia (CBC) on cardiac SR function and postischemic ventricular functional recovery in pig hearts. Twelve in situ isolated pig hearts supported by cardiopulmonary bypass were subjected to 120 minutes of cardioplegic arrest with either WBC (37 degrees C) or CBC (6 degrees to 10 degrees C), followed by 60 minutes of 37 degrees C reperfusion. Left ventricular global contractile function and coronary blood flow were measured before arrest and during reperfusion. Cardiac SR was isolated from left ventricular biopsy specimens, and 45Ca2+ uptake by SR and SR Ca(2+)-adenosine triphosphatase activity were determined. The recovery of left ventricular global contractile function as indicated by the maximum of the first derivative of left ventricular pressure was significantly improved in the WBC group compared with that of the CBC group (70% versus 46%; p < 0.05). The SR Ca(2+)-adenosine triphosphatase activity was better preserved after 60 minutes reperfusion in WBC compared with CBC (0.31 +/- 0.02 versus 0.20 +/- 0.03 microM Pi/min/mg protein, p < 0.05), and the recovery of SR Ca2+ uptake was significantly improved by WBC compared with CBC (1.15 +/- 0.12 versus 0.83 +/- 0.04 microM Ca2+/min/mg protein; p < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1993

Oligonucleotide-poly-L-ornithine conjugates: binding to complementary DNA and RNA.

On the basis of the reported enhanced antisense activity of polylysine-oligonucleotide conjugates, a synthetic 12-mer oligodeoxyribonucleotide has been coupled at its 5' terminus to a series of positively charged (delta-ornithine)n cysteine peptides. Binding between the nucleic acid-peptide conjugate and its complementary DNA target sequence was detected by the impact of complexation on the melting temperature (Tm). It was found that the Tm for the nucleic acid-peptide gradually increased with increasing net charge on the conjugated peptide. Site-directed cleavage with RNase H demonstrates that the peptide-modified oligomer also hybridizes with its RNA target sequence. Increased affinity for target mRNA with net charge was shown by a cell-free translation arrest assay.

Base Sequence↗
PubMed1993

Interleukin-1 alpha preconditioning reduces myocardial ischemia reperfusion injury.

BACKGROUND: Interleukin-1 (IL-1) has been shown to induce superoxide dismutase (SOD) activity and to express heat shock protein (HSP). Since the reperfusion of ischemic heart is associated with the reduction of antioxidative enzymes including SOD and expression of HSP, it was hypothesized that IL-1 could be beneficial against ischemic reperfusion injury. METHODS AND RESULTS: Rats were injected with recombinant IL-1 alpha (30 micrograms/kg IP); after 48 hours, they were anesthetized and hearts were removed, isolated, and perfused by the Langendorff technique. Myocardial functions were studied by measuring left ventricular developed pressure (LVDP) and its maximum first derivative (LV dP/dt), and cellular injury was studied by estimating creatine kinase (CK) release. Induction of the expression of HSP27 mRNA and HSP27 protein was examined by Western blot analysis and Northern blot analysis, respectively. Antioxidant enzymes were assayed by enzymatic analysis. Our results indicated reduction of ischemic reperfusion injury by IL-1 alpha, as evidenced by better recovery in postischemic ventricular functions (LVDP [mm Hg]: control, 63 +/- 14; IL-1, 102 +/- 11; P < .05), increased coronary flow (mL/min) (control, 2.93 +/- 0.58; IL-1, 5.17 +/- 0.43; P < .03), and reduced creatine kinase release (IU/L) (control, 110 +/- 5.78; IL-1, 81.76 +/- 7.71; P < .01). IL-1 alpha induced the expression of HSP27 mRNA within 2 hours as examined by Northern blot analysis and the expression of HSP27 after 48 hours. In addition, hearts pretreated with IL-1 alpha for 48 hours and then subjected to 30-minute ischemia and 60-minute reperfusion enhanced the activities (nmol/min/mg protein) of Cu/Zn SOD (control, 1.55 +/- 0.22; IL-1 alpha, 2.92 +/- 0.04; P < .004), Mn-SOD (control, 4.54 +/- 0.19; IL-1 alpha, 6.33 +/- 0.09, P < .001), catalase (control, 15.53 +/- 0.37; IL-1 alpha, 21.67 +/- 0.72; P < .002), glutathione peroxidase (control, 17.49 +/- 0.35; IL-1 alpha, 25.87 +/- 0.58; P < .001), and glucose-6-phosphate dehydrogenase (control, 22.71 +/- 0.44; IL-1 alpha, 29.53 +/- 0.48; P < .001). CONCLUSIONS: The results of this study indicate that low doses of IL-1 alpha can be used as a therapeutic agent to precondition a heart from ischemia reperfusion injury.

Animals↗
PubMed1992

Design of peptide-acridine mimics of ribonuclease activity.

A series of peptide-acridine conjugates was designed and synthesized, based on three features of the proposed catalytic mechanism of RNase A: 2'-proton abstraction by His-12, proton donation to the leaving 5'-oxygen by His-119, and stabilization of the pentacoordinated phosphorous transition state by Lys-41. The substrate binding capability of RNase A was mimicked by the intercalator, acridine. Lysine served as a linker between acridine and the catalytic tripeptide. Cleavage of target RNA was monitored by agarose gel electrophoresis and by gel-permeation chromatography. The carboxyl-amidated conjugates HGHK(Acr)-NH2, HPHK(Acr)-NH2, and GGHK(Acr)-NH2 (where Acr indicates 2-methyl-9-acridinemethylene) all had similar hydrolytic activity. The catalytic mechanism most likely involved only the abstraction of the 2'-proton and stabilization of the transition state. These RNase mimics utilized rRNA and single-stranded RNA but not double-stranded RNA and tRNA as substrates.

Acridines↗
PubMed1992

Diadenosine tetraphosphate binding protein from human HeLa cells: purification and characterization.

The ubiquitous dinucleotide P1,P4-di(adenosine-5') tetraphosphate (Ap4A) has been proposed to be involved in DNA replication and cell proliferation, DNA repair, platelet aggregation, and vascular tonus. A protein binding specifically to Ap4A is associated with a multiprotein form of DNA polymerase alpha (pol alpha 2) in HeLa cells. The Ap4A binding protein from HeLa cells has been purified to homogeneity starting from pol alpha 2 complex. The Ap4A binding protein is hydrophobic and is resolved from the pol alpha 2 complex by hydrophobic interaction chromatography on butyl-Sepharose and subsequently purified to homogeneity by chromatography on Mono-Q and Superose-12 FPLC columns. The Ap4A binding activity elutes as a single symmetrical peak upon gel filtration with a molecular mass of 200 kDa. Upon polyacrylamide gel electrophoresis under nondenaturing conditions, the purified protein migrates as a single protein of 200 kDa. Upon electrophoresis under denaturing conditions, the binding activity is resolved into two polypeptides of 45 and 22 kDa, designated as A1 and A2, respectively. A1 and A2 can be cross-linked using the homobifunctional cross-linking agent disuccinimidyl suberate. The cross-linked protein migrates as a single protein of 210 kDa on polyacrylamide gels under denaturing conditions, suggesting that these two polypeptides are subunits of a single protein. The purified protein binds Ap4A efficiently, and by Scatchard analysis, we have determined a dissociation constant of 0.25 microM, indicating high affinity of Ap4A binding protein to its ligand. ATP is not required for the binding activity. The nonionic detergent Triton X-100 is necessary for stabilizing the purified protein. Amino acid composition analysis indicates that A1 and A2 are distinct.

Amino Acids↗
PubMed1992

[Preliminary observation of imaging of facial temperature along meridians].

Visualization of meridians has been carried out by means of infrared thermography and radionuclide scintigraphy, but real success was hardly achieved on some special regions including facial channels. In this paper, we would represent some imagings of thermal line along channels by means of infrared thermography. Distribution of the facial temperature in 139 cases of healthy volunteers and 305 cases of patients with facial paralysis was observed with model AGA-782 infrared thermovision and TC-800 computer. In all cases of patients and 15 cases of healthy persons, acupuncture test was conducted. Special program, DISCO3.1 was used to process the thermographic data and the results were as follows: 1. Facial thermal line along channel was presented in 95 out of 444 cases. High temperature line along bladder channel appeared in 34 cases of them; 2. In 26 out of 95 cases, the thermal line appeared after acupuncture, which could improve the imaging of the line; 3. The range of the temperature was within 1.3 degrees C, in some cases only 0.2-0.3 degrees C, with +/- 0.5-1.0 degrees C difference to surrounding temperature; the width of the line was 1-1.5 cm in most cases; 4. The line could appear stably, in some cases, last for several days, weeks or months; 5. Certain relationship between the appearing of the line and facial paralysis was found. As mentioned above, the thermal characteristics of meridians in face could be visualized by means of infrared thermography, the special imaging of facial temperature along bladder meridian was easily found, related to facial troubles and promoted by acupuncture.

Acupuncture Therapy↗
PubMed1991

Clinical observations on acupuncture treatment of peripheral facial paralysis aided by infra-red thermography--a preliminary report.

We have carried out clinical observations on 34 patients with peripheral facial paralysis treated by acupuncture therapy prescribed according to selection of treatment regimen on the basis of facial thermogram and temperature. A comparison was made with a control group of 97 patients who received conventional acupuncture therapy only. It was found that 1) The cure rate in the group of selecting acupoints by thermogram (hereinafter referred to as the thermography--aided treatment group) was 67.65%, with a marked improvement rate of 26.40%; while the cure rate of the conventional acupuncture treatment group (hereinafter called the conventional treatment group) was 46.39%, the marked improvement rate being 29.90%, indicating a significant difference in therapeutic efficacy between the two groups (P less than 0.02). 2) The average duration of acupuncture therapy for the thermography aided treatment group was 6.02 weeks, whereas that for the conventional treatment group, 24 weeks. There was also a significant difference between the two groups (P less than 0.01). And 3) During the entire therapeutic course, 25.2 sessions of treatment were given on the average in the thermography--aided treatment group, and 78.8 sessions in the conventional treatment group, showing a very significant difference (P less than 0.001). The present thermography--aided method exhibits advantages over the conventional one in enhancing the cure rate and shortening the duration of treatment, which is worthy to be popularized in clinical practice. And it is also of certain significance in standardization and scientification of acupuncture therapy.

Acupuncture Points↗
PubMed1991

[The thermographic observation of the relationship between the retention of acupuncture needles and the effect of nose temperatures].

This is an observation of the relationship between the retention of acupuncture needles and its effect on nose temperature in seventy-four patients with facial nerve paralysis. The patients were divided into five groups according to the period of retention of needles: no retention, retention for ten, twenty, thirty and fourty minutes. Every group consisted twenty cases. The results showed that (a) the nose temperature lowered after acupuncture immediately; (b) then it rose and reached to the maximum at twenty minutes after acupuncture, then lowered again; (c) for the group of no retention and retention for ten and twenty minutes, the temperature rose again during thirty to fourty minutes after acupuncture, for the group of retention for thirty or fourty minutes, however, without these phenomena; (d) the general tendency was that the change of temperature was bigger but lasting for shorter period in the groups of retention for longer time than that in the groups of retention for shorter time. These results verified that some theories in ancient books about the retention of acupuncture needles are scientific.

Acupuncture Therapy↗
PubMed1990

[The comparison of changes of the facial temperature after acupuncturing point of hand and foot-yangming meridians by the thermography].

With thermographic technique, We observed changes of the facial temperature after acupuncturing Hegu (L14) and Zusanli (S36) in 65 patients (103 cases in all) with facial nerve paralysis. The observation showed that the average of Hegu group was higher than that of Zusanli group. The result explained that the effect of acupuncture at points of hand-yangming meridian was bigger than that of foot-yangming meridian on the facial temperature.

Acupuncture Points↗
PubMed1990

Research on the acupuncture principles and meridian phenomena by means of infrared thermography.

In this study, the observation on acupuncture manner, the specificity of acupoints, maintaining needle and "MiuCi" needling, manual and electrical acupuncture, the thermal characteristics of meridians etc. were carried out in order to apply the thermography in the research of principles of acupuncture and meridian phenomena thus create a way to approach to the mechanism of acupuncture effect. Results showed a good prospect for this technique being widely used in the investigation of acupuncture and meridians and its practical significance. It's also identified that the thermography with the advantages of straight-forward, objective and simple fitted to be used in the research of acupuncture and meridians.

Acupuncture Points↗
PubMedDate not supplied

Synthesis of oligoarginine-oligonucleotide conjugates and oligoarginine-bridged oligonucleotide pairs.

Conjugates consisting of oligoarginine peptides linked to oligodeoxynucleotides have been synthesized, including a new type of conjugate, in which a pair of oligonucleotides is bridged by a cationic peptide. Two different 9-mer oligonucleotides were conjugated to the terminal cysteine residues of the peptide series H-Cys-(Arg)n-Cys-NH2 (n = 3, 5, 7). Different thiol protecting groups were utilized on the amino- and carboxy-terminal cysteine residues of the peptide to allow selective attachment to the 3'- or 5'-terminus of each specific oligonucleotide. The conjugates containing oligoarginine peptides were purified by anion-exchange chromatography, and their structures were confirmed by polyacrylamide gel electrophoresis and amino acid analysis.

Amino Acid Sequence↗