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Biomedical subjects

Z Lin

Publications and source records attributed to Z Lin.

At least 19 recordsLinked to original sources

[Isolation of verocytotoxin-producing Escherichia coli from cattle and pets].

During a three-year period (1987 & 1990), a comprehensive attempt was made to isolate verocytotoxin-producing Escherichia coli (VTEC) from 96 bovine, 89 porcine, 67 canine and 18 feline cases suffering from gastroenteritis. VTEC were isolated from 11 cows and 1 cat. Bead-ELISA and oligonucteotide probes were used to type the verotoxins (VT) and it was found that the VTEC strains from cows produced not only the currently recognized VT1, VT2 and VT2vh but also produced two new VT's tentatively designated as VTx and VTy. The strain from the cat produced VTy. Serotyping of the strains revealed that some animal strains belonged to similar serotypes as those isolated from human patients with hemorrhagic colitis and hemolytic uremic syndrome. Cattle, especially cows, and domestic pets apparently are reservoirs of VTEC and probable sources of infection in our country as has been previously documented in Canada and USA.

Animals

[Isolation of vero-cytotoxin-producing Escherichia coli from cattle and serotyping and toxin-typing of the isolated strains].

Two hundred and sixty-six piglets with diarrhea (from 4 farms), 73 healthy pregnant pig (from 2 farms), 27 calves with diarrhea (from 9 farms) and 47 healthy milk cows (from 1 farm) were examined for Vero-cytotoxin-producing Escherichia coli (VTEC), and 52, 11, 15 and 67 strains of VTEC were isolated from 17 piglets, 11 pregnant pigs, 6 calves and 23 milk cows, respectively. All VTEC strains from the piglets produced only VT2vp, while the strains from the healthy pigs did not produce VT2vp, but did VT1 and/or VT2. Most VTEC strains from calves and cows produced VT2vhb and some produced VT2 and VT1. Serotyping of the isolated strains showed that many strains from the piglets belonged either O139:H1, O141:H4 or O141:HUT, but the strains from the pigs were either R-form or O-untypable. Many strains from the calves and cows were serotyped into O116 or O113, but there were several R-form and O-untypable. From these results, it is suggested that VTEC strains, especially from the pregnant pigs, calves with diarrhea and healthy milk cows, which produced the same type of Verotoxins to that produced by human isolates, may become sources of human infections.

Animals

Application of hemoglobin analysis by CO-oximeter to medico-legal practice with special reference to diagnosis of asphyxia.

Hemoglobin analysis by CO-oximeter is more easily and rapidly available method than other spectrophotometric or GC methods. In the present study, the possibility of diagnosis of asphyxia by CO-oximeter was examined experimentally using rabbits. When measured value of oxyhemoglobin (O2Hb) was lower than about 20% and that of deoxyhemoglobin (HHb) was, on the other hand, higher than about 80%, being accompanied by low measured values of both methemoglobin (MetHb) and CO-hemoglobin (COHb) (< 5%), asphyxia should be firstly considered as the cause of death. To the corpses found at the scene of fire, three chief factors causing death such as burns, suffocation due to oxygen deficiency and intoxication by poisonous gases may have occurred simultaneously, and through measuring the values of O2Hb, COHb, MetHb and HHb, the main lethal factor could be selected out among these three factors above and the cause of death could be examined much more closely. Because of easy and rapid analysis, it could be considered that CO-oximeter was useful for forensic practices and police activities.

Animals

[A preliminary approach of the malocclusion of second permanent molar].

We examined 2183 cases of orodental malocclusion in our clinic. 420 cases of deep-overjet of second permanent molar were found. In this paper we discussed the sex and age of the patients, distribution of tooth position, ratio, degree of overjet, causes of malocclusion, malocclusion condition, endangerment, prevention and treatment.

Activator Appliances

[Chemical studies on immunologically active polysaccharides of Ganoderma lucidum(Leyss. ex Fr.) Karst].

BN3B, the polysaccharide component of the fruit of Ganoderma lucidum, has been shown to have immune activity. From BN3B four homogeneous polysaccharides were separated and purified. Chemical studies on the main components BN3B1 and BN3B3 indicated that BM3B1 contained only glucose and should be a glucan containing beta-(1----6) and (1----3)glycoside bonds and that BN3B3 was an arabinogalactan containing beta-(1----6) and (1----3)glycoside bonds.

Adjuvants, Immunologic

[An autopsy case of fatal nicotine poisoning].

A fatal case of nicotine poisoning is reported in which a 44-year-old female committed suicide in a short time by taking orally the eluate from tobacco. External examination showed no abnormal findings except for markedly dark red-purple postmortem lividity, and internal examination demonstrated no pathological changes but the signs of sudden death. Through the toxicological investigation by GC and GC-MS, however, nicotine was detected in the solution which she had taken orally and in the blood, urine and the contents of the stomach and small intestine. The nicotine concentrations of the blood, urine and contents of stomach and small intestine were 6.3 micrograms/ml, 1.5 micrograms/ml, 30 micrograms/ml and 71 micrograms/g respectively, and enough to be lethal.

Adult

Transcatheter ablation of the accessory pathway in 2 patients with life-threatening tachyarrhythmias.

Successful transcatheter ablation of an accessory pathway in 2 patients with life-threatening tachyarrhythmias is reported. In both cases, electrophysiological evaluation documented the posterior septal location of the anomalous atrioventricular connection. Radiofrequency current energy was delivered just below the coronary sinus orifice, and resulted in disappearance of preexcitation. During the follow-up, both patients remained free from tachyarrhythmias on no medication, and serial electrocardiographic recordings confirmed the persistent absence of preexcitation. It is concluded that ablation of accessory pathways can be accomplished easily and without risk by means of the radiofrequency catheter technique. This therapeutic modality requires a short hospitalization and can be recommended as the first option in patients with the Wolff-Parkinson-White syndrome.

Adult

Hepoxilin A3 induces heat shock protein (HSP72) expression in human neutrophils.

In this paper we show that hepoxilin A3 induces the expression of heat shock protein expression in human neutrophils at a concentration of 100 nM using Western blotting techniques employing the use of a commercial monoclonal antibody to HSP72. No regiospecificity was observed as the 8S enantiomer of HxA3 was as active as the 8R enantiomer of HxA3. Comparison of the effects of HxA3 with 12S-HETE and PGA1 indicated that HxA3 was as effective as 12S-HETE although PGA1 was essentially inactive at the same concentration used for these 12-lipoxygenase products.

12-Hydroxy-5,8,10,14-eicosatetraenoic Acid

cAMP and cAMP-dependent protein kinase regulate the human heat shock protein 70 gene promoter activity.

The theme of this study is an evaluation of the involvement of cAMP and cAMP-dependent protein kinase (PKA) in the regulation of the human heat shock protein (hsp) 70 gene promoter. Expression of a highly specific protein inhibitor of PKA (pRSVPKI) inhibited the basal as well as heat- and cadmium-induced expression of the cotransfected pHBCAT, a human hsp 70 promoter-driven reporter gene; this inhibition was dependent on the amount of pRSVPKI used. The effect of an expression vector of the RI regulatory subunit of PKA, pMTREV, was similar to that of pRSVPKI; pMTREV inhibited both the basal as well as the heat-induced expression of pHBCAT. The specificity of effects of these expression vectors was demonstrated by the lack of effect of a mutant PKI gene and by the unaffected expression of a reference gene (pRSV beta gal) under these conditions. Analysis of the effects of dibutyryl cAMP (1 mM), forskolin (10 microM), and 8-Br-cAMP (1 mM) on the transient expression of pHBCAT showed that these cAMP-elevating agents stimulated the hsp 70 promoter activity, whereas cAMP (1 mM) was without effect. Chloramphenicol acetyltransferase gene constructs with truncated or mutated hsp 70 promoter were used to define the cis-acting DNA element(s) that confer this cAMP stimulation; the heat induced (42 degrees C) expression was used as a control. Mutation of the adenovirus transcription factor element (pLSN-40/-26) greatly reduced the basal level of expression; forskolin had little or no effect on this adenovirus transcription factor-minus promoter, although the promoter activity was very heat inducible. The absence of a functional heat shock consensus element (HSE) in the construct pLSPNWT rendered the promoter heat insensitive; this construct was forskolin responsive although the magnitude of this stimulation was reduced when compared with that of a control construct with HSE. These results were corroborated by studies using consensus sequence of ATF (ATFE) and HSE as competitors to titrate our cellular factors that may interact with these elements. We showed that cotransfection with ATFE and HSE depressed the basal (37 degrees C) expression of pHBCAT by 25 and 60%, respectively. The heat-induced expression of pHBCAT was not significantly affected by the cotransfection of ATFE and was reduced by 60% when HSE was cotransfected. ATFE and HSE reduced the forskolin-induced pHBCAT expression by 70 and 40%, respectively. The implications of these findings as they relate to the action of cAMP and cAMP-dependent protein kinase in the control of heat shock gene expression are discussed.

8-Bromo Cyclic Adenosine Monophosphate

A new typing method for the avian infectious bronchitis virus using polymerase chain reaction and restriction enzyme fragment length polymorphism.

Two primers with the length of 22 bases each and 400 bases apart on the spike protein gene of avian infectious bronchitis virus (IBV) were prepared. Using these primers, the genome RNA from twelve strains of the various serotypes were reverse-transcribed to cDNA and amplified by polymerase chain reaction (PCR). With all strains, 400 base DNA was amplified, indicating that there were no apparent insertions or deletions in this region. However, the amplified DNA showed different cleavage patterns by the restriction enzymes. These 12 strains were classified into 5 groups. The strain typing based on a comparison of the cleavage patterns was consistent with the previous serological typing. This study thus provides a simple and rapid method for typing of IBV.

Animals

[Analysis of outer membrane proteins from eight strains of Campylobacter in SDS-PAGE].

The outer membrane proteins (OMPs) from 8 strains of Campylobacter, including 5 reference strains and 3 local strains, were isolated and examined by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). The results showed that the population distributions of molecular weight of OMPs from different species and sources were alike based on the Rank Sum Test analysis. The number of bands of major OMP was around 2-3, the molecular weight of which varied from 33-68 kd. Moreover, three C. jejuni local strains isolated from patients in China showed common characteristics of OMPs to the reference strains. It is suggested that the OMPs of Campylobacter are of a conservative and stable structure.

Bacterial Outer Membrane Proteins

[Detection of Plasmodium falciparum infection in humans by (Dig)-DNA probe].

In this study, we used Digoxigenin, (Dig)-11-dUTP, in the Genius kit purchased from Boehringer Mannheim to label the Plasmodium falciparum (P.f.) DNA fragment by random primed labelling method. The P. falciparum DNA fragment was isolated from the recombinant clone pPF14 by enzyme digestion and agarose electrophoresis. This probe is designated pPF14-F-Dig. Purified P.f. DNA and blood samples from malaria patients in Hainan Province of China were detected by the probe in dot-blot hybridization. Thirty-eight patients with falciparum malaria, three with falciparum malaria and vivax malaria and four with vivax malaria were detected with the pPF14-F-Dig probe. The results showed that the pPF14-F-Dig probe could detect at least 40 pg of P.f. DNA and a parasitemia of 0.005 percent. Out of 38 detected P.f. patients' blood samples, 33 hybridized positively with this probe. The positivity rate was 86.8%. Twenty-one normal blood samples all showed negative. In addition, 2 of 3 samples with P.f. and P.v. were positive. Three of 4 samples with P.v. were negative and one was doubtful. The preliminary result of this study indicates that the pPF14-F-Dig probe could detect the patients of falciparum malaria with good sensitivity and specificity, and that this probe can be used to detect the patients with P. falciparum in Hainan Province.

Animals

Comparison of the effectiveness between anterior capsulotomy with Nd:YAG laser and with bent needle in patients with congenital cataract.

The effectiveness of capsulotomy with Nd:YAG laser and with bent needle were compared in 50 patients (66 eyes) with congenital cataract. There were 24 patients (32 eyes) in the laser group and 26 patients (34 eyes) in the needle group. There were not significant differences in sex, age, pre-operative visual acuity and intraocular pressure, and classification of cataract between the two groups. The results show that patients in the laser group have better post-operative visual acuity. The reason is YAG laser capsulotomy lessens the entering of anterior chamber by instruments. The stress on the periphery retina is reduced. The lens cortex is more readily aspirated. In turn, post-operative complications are avoided.

Adolescent

[Outpatient intraocular lens implantation].

The extracapsular cataract extraction with posterior chamber intraocular lens implantation (ECCE with PC IOL) was performed on 113 cases (120 eyes) with senile cataract. Half a year after the surgery, uncorrected visual acuity of 0.5 or better was achieved in 65.83%; corrected visual acuity of 0.5 or better in 93.33%, 1.0 or better in 82.50%. The intraoperative complications included vitreous prolapse, residual corte, iridodialysis and Descemet's membrane stripping. The postoperative complications were opaque posterior capsule, iris synechiea, IOL dislocation. The post-operative visual acuity and complications of the outpatient surgery was not significantly different compared to inpatient ECCE with PC IOL. The results showed that outpatient cataract surgery is safe. The advantage and disadvantage of outpatient IOL implantation were discussed, and some measures to popularize this operation for outpatient were recommended.

Aged

Age-dependent decrease in the heat-inducible DNA sequence-specific binding activity in human diploid fibroblasts.

In order to gain a better understanding of the molecular mechanism of the attenuated heat shock response in aging diploid fibroblasts (Liu, A. Y.-C., Lin, Z., Choi, H.-S., Sorhage, F., and Li, B. (1989) J. Biol. Chem. 264, 12037-12045), we examined the regulation of a heat-inducible, heat shock element (HSE) sequence-specific binding protein in IMR-90 diploid fibroblasts. Using gel retardation assay, we showed that the HSE binding activity in extracts of IMR-90 cells was very dependent on heat shock of the cells; that the induction was transient with a maximal increase observed at 1 h of heat shock. Significantly, the level of this heat-inducible HSE-binding activity was age-dependent, being high in young cells and low in old cells. By Scatchard analysis, we determined that this difference in HSE binding in young and old cells was not due to a change in the affinity of the binding, rather the level of the heat-inducible HSE-binding activity was different. The equilibrium dissociation constants (Kd) were estimated to be 30, 25, and 31 pM for cells with population-doubling levels of 22, 35, and 45, respectively; the corresponding Bmax values were 0.087, 0.042, and 0.0059 pmol of 32P-HSE bound per mg of whole cell extract protein. The decreased 32P-HSE-binding activity in the old cells was not a reflection of global alteration of many transcription factors; assay of the DNA binding activity of activating transcription factor showed little difference as a function of age. Experiments of mixing extracts from young and old cells provided evidence of a dominant inhibitor of the HSE-binding activity in old cells. Probing of protein blots with 32P-HSE showed that the subunit molecular weight of the HSE-binding protein was 83,000 in both young and old cells. The pattern of regulation of this HSE-binding protein upon heat shock and cell aging as well as the identity, in DNA sequence specificity and subunit molecular weight, of this protein with that of the human heat shock gene transcription factor suggest that the HSE-binding protein is involved in the transcriptional activation of hsp genes in IMR-90 cells. We concluded that there was an age-associated decrease in the heat shock gene transcription factor DNA-binding activity and that this could account for the attenuated heat shock gene expression in aging diploid cells.

Base Sequence

[Lymphatic distribution and ultrastructures of human larynx].

Thirteen adult human larynges were studied by indirect lymphangiography to observe laryngeal lymphatic distributions. Results were as follows: (1) The laryngeal lymphatic system was composed of lymph capillaries and larger lymph vessels. (2) Laryngeal lymphatics had common ultrastructural characteristics of lymphatics elsewhere. (3) Based on lymphatic anatomies, the larynx might be divided into four regions: supraglottic, right and left glottic, and subglottic regions. (4) A single layer of lymphatic network in the anterior commissure region had been found.

Humans

Treatment of 910 cases of atrophic gastritis with wei you decoction.

In treatment of 910 cases of chronic atrophic gastritis with Wei You Decoction, the overall effective rate was 96.9%. The disease was considered as due to deficiency of vital energy with stagnation of cold, and therefore treatment was to invigorate blood circulation. The Wei You Decoction had functions of replenishing vital energy, warming the middle burner, invigorating blood circulation, and resolving stasis, thus reversing the morbid process in the gastric mucosa. It was nontoxic, and the side-effects were minimal. The therapeutic effect was prompt and persistent. No malignant change was observed after taking the drug.

Adult