PubMed Health⌕ Search

Biomedical subjects

M Yu

Publications and source records attributed to M Yu.

At least 379 records · Page 21Linked to original sources
PubMed1992

The inhibitory effect of furosemide on the contractile response of equine trachealis to cholinergic nerve stimulation.

The effects of furosemide on the responses of equine trachealis muscle with and without epithelium to electrical field stimulation (EFS) and exogenous acetylcholine (ACh) were investigated in organ baths. Tissues were pretreated with guanethidine and the parameters used for EFS were those previously demonstrated to activate postganglionic cholinergic neurons. In tissues with intact epithelium, furosemide (100 microM) shifted the frequency-response curve to the right. In the preparations without epithelium, furosemide did not affect the response to EFS. Neither in epithelium-on nor in epithelium-off tissues was the ACh dose-response curve affected by the administration of furosemide. We conclude that furosemide (100 microM) decreases the equine tracheal smooth muscle responses to EFS through inhibition of cholinergic neurotransmission, and that this effect is dependent on epithelium.

Acetylcholine↗
PubMed1992

[Observation on 63 cases of facial paralysis treated with acupuncture].

Sixty-Three cases with facial paralysis were treated mainly by acupuncture combining with point injection. The main points selected were Yangbai (GB14), Wai Jingming (BL1), Sibai (ST2), Yingxiang (LI20), Dicang (ST4), Jiache (ST6), Quanliao (ST18) and Qianzheng. The points were used alternatively. Auxiliary points: for type of deficiency of both qi and blood, Zusanli (ST36), and Sanyinjiao (SP6) were added: for type of disharmony between Ying and Wei, Fengchi (GB20) and Hegu (LI4) were added; for type of stagnancy of qi and blood, Weiguan (TE5) and Taichong (LR3) were added; for type of wind-heat stagnating collaterals, Yifeng (TH17) and Yanglingquan (GB34) were added. 10 out of 60 cases, which showed no remarkable effectiveness after two courses, injection of vitamin B1 and vitamin B12 to facial points combined with Hegu (LI4) point on opposite side was performed. Therapeutic results: 31 cases (49.2%) were cured, 15 cases (23.8%) markedly effective, 16 cases (25.4%) effective and 1 case (1.6%) ineffective.

Acupuncture Points↗
PubMed1992

Quantitative evaluation of flicker ERG waveforms in low vision patients.

Flicker electroretinograms (FERGs) of 30Hz were recorded for 46 eyes (23 cases) of low vision, including 38 eyes with retinal diseases and 8 eyes with optic neuropathy, and for 39 normal eyes (33 cases). The recorded wave forms were analysed by two methods: (1) to measure the peak to peak amplitude and pseudophase directly, and (2) to measure the amplitude and phase of fundamental response component (30Hz) by discrete Fourier transform (DFT). The abnormality ratios between these two methods were compared in low vision patients. All the eyes with optic neuropathy showed normal flicker ERG, the abnormality ratios of directly measured amplitude and the amplitude by DFT were 60.9% in 28 eyes and 71.7% in 33 eyes with retinal diseases respectively, the difference being no statistically significant (P > 0.05), while the abnormality ratios of directly measured pseudo-phase and the phase by DFT were 60.9% in 28 eyes and 82.6% in 38 eyes with retinal diseases respectively, the difference being statistically significant (P < 0.05). These results suggest that FERGs are an objective way to test the retinal function, and DFT for flicker ERGs are more useful in quantitative evaluation of the retinal function.

Adolescent↗
PubMed1992

[Modification and expression of insecticidal protein structural gene of Bacillus thuringiensis var. aizawai 7-29].

The regulative region (181bp) and the fifth toxic active domain (217bp) were removed from the insecticidal protein gene of Bacillus thuringiensis var. aizawai 7-29. After the synthesis of the adaptor (15bp) that contains initiation codon (ATG) and the PCR synthesis of the fifth toxic active domain (229bp) that contains stop codon (TAA), were inserted into on 5' truncated and 3' truncated of the coding fod N-terminal peptid's DNA fragment, that to become a modified structural gene. The modified structural gene can be play initiatic translation-function and stop translation-function during translation of insecticidal protein. The insecticidal protein was determined by western blotting, showed the expression of modified structural gene in Escherichia coli JM 103. The bioassay of insecticidal proteins showed the 3' truncated and 5' truncated of insecticidal gene was higher toxic active than the 3' truncated of insecticidal gene in Escherichia coli JM 103.

Bacillus thuringiensis↗
PubMed1992

[Changes in LAK cell activity in chronic viral hepatitis and treatment with autologous LAK cell transfusion].

We investigated the activity of LAK cells in 10 patients with chronic persistent hepatitis, 20 patients with chronic active hepatitis, 21 patients with post-hepatitic cirrhosis and 21 normal persons. The values were 36.87 +/- 7.44, 30.38 +/- 5.36, 28.84 +/- 4.95 and 44.50 +/- 4.75 respectively (P < 0.05). The LAK cell activity in patients with chronic hepatitis was lower than that of normal persons, especially in those with chronic active hepatitis and post-hepatitic cirrhosis. The causes of lower LAK cell activity in patients with chronic hepatitis were less expression of IL2 receptors on precursors of LAK cells and existing serum LAK cell inhibition factors. We further studied 9 patients with chronic hepatitis B treated with autologous LAK cell transfusions. Factors favoring a more effective result were female sex, ALT elevation after treatment, activity of LAK cells > 10%, and inhibition factor of LAK effector cells existing in serum of patients, with inhibition rate < 50%. These factors might be used as the indications in selecting cases for treatment and predicting the effect of the treatment. As the number of cases observed was rather small, further investigation is needed.

Adolescent↗
PubMed1991

Comparison of the autoSCAN-W/A rapid bacterial identification system and the Vitek AutoMicrobic system for identification of gram-negative bacilli.

The autoSCAN-W/A (W/A; Baxter MicroScan, West Sacramento, Calif.) with the new fluorometric Rapid Neg Combo 1 (RNC) panel is a fully automated fluorometric system for identification of both enteric and nonenteric gram-negative bacilli within 2 h. We compared the W/A with the Vitek AutoMicrobic System (Vitek AMS; Vitek Systems, Inc., Hazelwood, Mo.) for identification of 383 clinical isolates of gram-negative bacilli. The API 20E (Analytab Products, Plainview, N.Y.) and conventional biochemical testing were used as the reference systems. The W/A correctly identified 336 isolates (87.7%) to the species level and classified an additional 29 isolates (7.6%) as correct with low probability (overall identification = 95.3%); the Vitek AMS correctly identified 355 isolates (92.7%) to the species level and classified an additional 8 isolates (2.1%) as correct with low probability (overall identification = 94.8%). A common set of 134 isolates of gram-negative bacilli was tested in both participating laboratories as a means of assessing interlaboratory agreement with both the W/A and the Vitek AMS. The overall agreements between the two laboratories were 86% with the W/A and 92% with the Vitek AMS. The W/A performed comparably to the Vitek AMS for identification of most gram-negative bacilli, actually exceeding the Vitek AMS for identification of nonenteric bacilli. Rapid time to identification and a high level of automation make the W/A an attractive system for clinical microbiology laboratories.

Bacteriological Techniques↗
PubMed1991

A domain of the hepadnavirus capsid protein is specifically required for DNA maturation and virus assembly.

Mutations introduced into the capsid gene of duck hepatitis B virus (DHBV) were tested for their effects on viral DNA synthesis and assembly of enveloped viruses. Four classes of mutant phenotypes were observed among a series of deletions of covering the 3' end of the capsid open reading frame. Class I mutant capsids were able to support normal single-stranded and relaxed circular viral DNA synthesis; class II mutant capsids supported normal single-stranded DNA synthesis but not relaxed circular DNA synthesis; class III mutant capsids resembled class II capsids, but viral DNA synthesis was inhibited 5- to 10-fold; and class IV capsids were severely restricted in their ability to support viral DNA synthesis. Class I capsids were assembled into enveloped virions, but class II, III, and IV capsids were not. Viral DNA synthesized inside class II capsids was normal with respect to minus-strand DNA initiation, plus-strand DNA initiation, and circularization of the DNA, but plus strands failed to be elongated to mature 3-kb DNA. The results suggest that a function of the capsid protein specifically required for viral DNA maturation is also required for assembly of nucleocapsids into envelopes. Thus, class II mutants appear to be defective in the appearance of the "packaging signal" for virus assembly (J. Summers and W. Mason, Cell 29:403-415, 1982).

Amino Acid Sequence↗
PubMed1991

[Construction of phage vector for Bacillus subtilis].

Recombinant phages phi 105S35 and phi 105S36, derived from phage phi 105DI:1t, remain the ability to infect and be lysogenized in the host cell. In the their genome there is a 1 kb inset fragment which occurs between the DNA fragments D and E resulted from SmaI degested DNA of phi 105DI:1t. But the orientation of this insert fragment is opposite in two recombinant phages, respectively. The cat gene on this fragment makes the host cell resistant to chloramphenaical. The unique BamHI and XbaI sites which were introduced into the genome of the recombinant phages provide inserting sites of foreign DNA fragment. DNA from these two recombinant phages can transfect protoplast of Bacillus subtilis at high frequency. Therefore, phi 105S35 and phi 105S36 are suitable as phage vectors in the molecular cloning of Bacillus subtilis.

Bacillus subtilis↗
PubMed1991

[Immunopathological study of synovium of rheumatoid arthritis].

46 patients with different rheumatic disorders were subjected to arthroscopic examination and the biopsied synovia were studied immunopathologically. Immunoglobulins, complements and fibrinogen deposition were detected by direct immunofluorescence, and rheumatoid factor (RF) deposition was detected by peroxidase-labelled denatured human IgG. Postoperative diagnosis of these cases were as follows: rheumatoid arthritis (RA) 21; seronegative spondylarthropathy 4; reactive arthritis 2; unidentified synovitis 4; osteoarthritis 8; and nonsynovitis conditions 5. It was shown that the positive rates of deposition of IgG, IgM, complement C3, C1q and C4, and RF in RA were 95.2%, 52.4%, 38.1%, 28.6%, 9.5% and 42.9%, respectively. Deposition was negative in all other rheumatic diseases. The positive fibrinogen deposition rate in RA was 42.9%; it was weakly positive in other disorders as well. The results indicate that the pathogenesis of RA is related to humoral immunity, and immunopathological study of the synovium has very important diagnostic significance in RA. On the other hand, deposition of fibrinogen lacks specificity for any rheumatic disease. The deposition of RF IgG, IgM and complement C3, C1q and C4 in the synovium of RA patients does not correlate well with clinical disease activity. The deposition of RF in the synovium also does not show paired correlation with blood IgM RF determination. This difference may be explained by the fact that the synovial RF examined in the present study may include all isotypes of RF and that hidden-RF in the blood may give a negative result. The synovium is the site of production of RF, but the degree of pathological change of the synovium of different joints in a single patient may not be uniform. The results of humoral immunity studies of the RA synovium may be influenced by the site selected for synovial biopsy.

Adolescent↗
PubMed1991

[Pigmentary glaucoma and capsular glaucoma--a clinical and histopathological report].

In this paper, 7 cases (13 eyes) of pigmentary glaucoma and 9 cases (12 eyes) of capsular glaucoma were reported. Pigmentary dispersion in pigmentary glaucoma, pseudo-exfoliation material deposition in capsular glaucoma were the classical characteristics in the anterior segment of the eye, but pigmentary scatter was another clinical feature of capsular glaucoma. The histopathological studies of the trabeculectomy specimens by the light and transmission electron microscopy demonstrated that pigment granules or/and pseudo-exfoliation materials played an important role in obstructing the outflow tract of aqueous humor. In addition, we also discuss the diagnosis and differential diagnosis of both types of glaucoma.

Adult↗
PubMed1991

[Clinical significance of determination of urinary albumin, beta 2 microglobulin and Tamm-Horsfall protein in diabetics].

Twenty-four hour urinary albumin (Alb) beta 2 microglobulin (beta 2m) and Tamm-Horsfall protein (THP) were measured by radioimmunoassay in 69 diabetics and 23 normal controls. The excretion of urinary Alb, beta 2m and THP in the patients with diabetic nephropathy was found to be different from that of normal controls. The abnormality of excretion of Alb, beta 2m and THP is particularly evident in the patients with clinical diabetic nephropathy. These results indicate that the renal lesions of diabetes mellitus exist not only in the glomeruli but also in the proximal and/or distal tubules. There was a significantly positive correlation between THP excretion and creatinine clearance (less than 127 ml/min/1.73m2). The findings suggest that the excretion of urinary THP is a valuable index for evaluating the damages of nephrons. It is believed that determination of urinary Alb, beta 2m and THP in diabetics is beneficial to early detection of the sites and degree of the renal lesions.

Adult↗
PubMed1991

Changes in lymphocyte subpopulations as a result of cardiopulmonary bypass. The effect of blood transfusion.

Cardiopulmonary bypass is associated with postoperative humoral and cellular immune changes. Postoperative decrease in T helper (CD4), T suppressor (CD8), and B lymphocyte counts; decrease or reversal of the CD4/CD8 ratio; and poor in vitro response to mitogens have also been observed. Similar changes in lymphocyte number and function have also been noted in patients receiving transfusions. To determine whether observed changes after cardiopulmonary bypass are related to the bypass itself or to associated blood transfusions, we conducted a study of lymphocyte subsets in transfused and nontransfused patients. A flow cytometric analysis of seven lymphocyte subpopulations was conducted in 18 patients undergoing bypass, eight of whom did not receive a transfusion. The transfused group comprised recipients of both homologous (n = 8) and autologous (n = 2) blood. Total lymphocytes and lymphocytes with markers for CD3 (pan-T cells), CD4, and CD8 decreased significantly postoperatively independent of transfusion. B lymphocytes decreased postoperatively in both the autologous transfusion and no transfusion groups. However, this trend was not seen in patients receiving homologous blood, and three of these patients had evidence of T cell activation, suggestive of an immune response to homologous transfusion. Bypass produces significant changes in selected lymphocyte subsets. Furthermore, simultaneous homologous blood transfusion may specifically elicit an immune response in some patients undergoing cardiopulmonary bypass.

Adult↗
PubMed1991

Proteins isolated from regenerating sciatic nerves of rats form aggregates following posttranslational amino acid modification.

Soluble proteins of regenerating sciatic nerves of rats can be posttranslationally, covalently modified by a variety of radioactive amino acids. The present study shows that once modified by a mixture of 15 amino acids, many of those proteins form aggregates that are unable to pass through a 0.45-micron filter and pellet following 20,000g centrifugation (suggesting a size of greater than 2 x 10(6) Da). Aggregation of proteins also occurs following modification by Arg or Lys alone, but does not occur following protein modification in nonregenerating nerves or in brain. Aggregates are not disrupted by treatment with 100 mM beta mercaptoethanol or by exposure to 1.0 M NaCl, but aggregates are solubilized by treatment with urea and by boiling in 1.5% SDS. Amino acid analysis of proteins modified by a mixture of [3H]amino acids shows a similar proportion of posttranslationally incorporated Ser, Pro, Val, Ala, Leu, Phe, Lys, and Arg in the soluble and pelletable fractions. Two-dimensional PAGE profiles of soluble and pelletable modified proteins show that the modified proteins in both fractions are in similar pI and molecular weight ranges, except that the soluble modified proteins include a high-molecular-weight component that is absent in the pelleted modified proteins. Kinetic studies show that while half-maximal levels of protein modification occur within 30 seconds of incubation, the appearance of the pelletable modified protein fraction is delayed significantly. These results indicate that amino acid modification of soluble proteins in regenerating sciatic nerves of rats results in physical changes in those proteins so that they form high-molecular-weight aggregates.(ABSTRACT TRUNCATED AT 250 WORDS)

Amino Acids↗
PubMed1990

Amino acid modification of proteins in regenerating sciatic nerves of rats.

Recent experiments have shown that Arg, Lys, and Leu can be incorporated posttranslationally into proteins of regenerating sciatic nerves of rats. The present experiments investigate a mixture of 15 radioactive amino acids to determine if additional amino acids can be conjugated posttranslationally to proteins of regenerating nerves. Proteins of regenerating sciatic nerves of rats were able to incorporate Arg, Lys, Leu, Pro, Val, Ala, Phe, and Ser in relatively large amounts and Asp, Glu, Thr, Gly, Ile, His, and Tyr in relatively low or undetectable amounts, in the most advanced portion of the regenerating nerves. Two-dimensional SDS PAGE showed incorporation of the amino acid mixture into distinct radioactive peaks with molecular weights in the 80-90 kD, 53-66 kD, 22-46 kD, and 17 kD ranges with isoelectric points between 5.0 and 7.9. Most of the amino acids were incorporated into proteins in all of the molecular weight ranges. But Ser was incorporated in highest amounts in the 17 kD range, and Val was most abundant in the 22-46 kD range. In some cases results indicated that single proteins were modified by several amino acids. While we do not yet know which amino acids modify specific nerve proteins or the function of the modifications in nerve regeneration, these studies demonstrate the participation of some but not all amino acids in posttranslational modification reactions and the selective modification of specific groups of nerve proteins by these amino acids.

Amino Acids↗
PubMed1990

Loss of heterozygosity in mammalian cell mutagenesis: molecular analysis of spontaneous mutations at the aprt locus in CHO cells.

Loss of heterozygosity at previously heterozygous loci may occur by one of several possible mechanisms and account for a large fraction of all mutations occurring at such loci. In order to investigate loss of heterozygosity events, we have chosen the aprt locus of Chinese hamster ovary (CHO) cells as our model since it is readily available in either heterozygous or hemizygous form. Cloning and sequencing of the two heterozygous aprt alleles from the CHO derivative D423 identified a single polymorphic site, which does not create a restriction fragment length polymorphism. In order to evaluate the loss of heterozygosity events at this locus, we devised a method that creates an artificial restriction fragment length polymorphism in one of these two alleles as a direct consequence of enzymatic amplification. Restriction enzyme digestion of the amplified sequences can then conveniently identify the genotype of the DNA sample. This same methodology also provides for the selective cloning of only one allele of a heterozygous pair into a plasmid vector for subsequent DNA sequence analysis, and can be easily adapted to other situations requiring the analysis of single base changes at a particular position within known sequences. Using this technique, we have determined that 16/37 (43%) spontaneous APRT- mutants had undergone a loss of heterozygosity event.

Adenine Phosphoribosyltransferase↗
PubMed1990

Dermal nerve sheath myxoma.

A case of dermal nerve sheath myxoma on the left palm of 26-year-old Japanese man is presented. We examined this tumor by light and electron microscopies. On light microscopic examination, this tumor was characterized by a multilobulated myxoid tumor composed of stellate cells in an abundant mucous matrix. This histological feature resembled previously reported cases of dermal nerve sheath myxoma. On electron microscopic examination, the findings of these tumor cells were similar to those of the perineurial cells. These microscopical examinations have provided evidence for an origin from perineurial cells rather than Schwann cells.

Adult↗
PubMed1990

Clinical application of microcomputer to visual function examination.

Microcomputer technique is put into use in ophthalmological clinical visual function examination. In visual EOG, ENG, visual tracking, contrast sensitivity and VEP examination, objectifying and standardization of experiment and data analysis are achieved by computer technique. In addition, a lot of manpower and time is saved, test results are obtained faster and more accurately. The basic rational of computerization in clinical visual function examination is presented.

Adult↗