Biomedical subjects

Y Gu

Publications and source records attributed to Y Gu.

At least 271 records · Page 15Linked to original sources

PubMed1996

Influence of salbutamol and isoproterenol on the production of TNF and reactive oxygen species by bovine alveolar macrophages and calcitriol differentiated HL-60 cells.

The influence of the beta-adrenergic agonists Salbutamol and Isoproterenol on the release of reactive oxygen species and Tumor Necrosis Factor (TNF) was tested with bovine alveolar macrophages and HL-60 cells differentiated to macrophages by calcitriol. The production of reactive oxygen species was analyzed by a microplate assay using dichlorofluorescein-diacetate. It could be shown that this method almost exclusively measures superoxide anions. TNF was determined by a bioassay with WEHI cells. The superoxide anion production was stimulated by Zymosan, the TNF release by LPS. By incubation with 5 x 10(-6) and 5 x 10(-7) M Salbutamol or 5 x 10(-7) and 5 x 10(-8) M Isoproterenol prior to the stimulation, the production of superoxide anions as well as of TNF was inhibited to a significant degree. The inhibitory effects of the adrenergic agonists were completely or at least partially inhibited by the respective antagonists, ICI 118.551 and Propranolol, respectively.

Albuterol↗

PubMed1996

Advanced maternal age and the risk of Down syndrome characterized by the meiotic stage of chromosomal error: a population-based study.

The identification of DNA polymorphisms makes it possible to classify trisomy 21 according to the parental origin and stage (meiosis I [MI], meiosis II [MII], or postzygotic mitotic) of the chromosomal error. Studying the effect of parental age on these subgroups could shed light on parental exposures and their timing. From 1989 through 1993, 170 infants with trisomy 21 and 267 randomly selected control infants were ascertained in a population-based, case-control study in metropolitan Atlanta. Blood samples for genetic studies were obtained from case infants and their parents. Using logistic regression, we independently examined the association between maternal and paternal age and subgroups of trisomy 21 defined by parental origin and meiotic stage. The distribution of trisomy 21 by origin was 86% maternal (75% MI and 25% MII), 9% paternal (50% MI and 50% MII), and 5% mitotic. Compared with women <25 years of age, women > or = 40 years old had an odds ratio of 5.2 (95% confidence interval, 1.0-27.4) for maternal MI (MMI) errors and 51.4 (95% confidence interval, 2.3-999.0) for maternal MII (MMII) errors. Birth-prevalence rates for women > or = 40 years old were 4.2/1000 births for MMI errors and 1.9/1000 for MMII errors. These results support an association between advanced maternal age and both MMI and MMII errors. The association with MI does not pinpoint the timing of the error; however, the association with MII implies that there is at least one maternal-age related mechanism acting around the time of conception.

Adult↗

PubMed1996

Morphological observations of vas deferens occlusion by the percutaneous injection of medical polyurethane.

Histological observations of 20 occluded vas segments obstructed by the standard procedure of medical polyurethane-vas occlusion in 10 volunteers requesting vasectomy and of 20 vas segments with plugs removed from 10 vas-occluded men requesting vas reversal were carried out in order to elucidate the mechanism of vas occlusion by medical polyurethane (MPU). Twenty vas deferens in vasectomy group were ruptured, only a small amount of MPU elastomer remained within the vas lumen, most having leaked through to encircle the ruptured vas. Histomorphology of the removed vas segments from 10 vas-occluded men, who had undergone MPU-vas occlusion 4 years earlier, showed diffuse proliferation of connective tissue, fibrosis, or hyalinization of fibroplastic tissue and local infiltration of lymphocytes and macrophages. The vas lumen both proximal and distal to the plugs was completely blocked. Sperm granuloma, foreign body granuloma, proliferation of nerve fibers and local infiltration of lymphocytes were found in four vas-occluded men with painful nodules. These results suggest that the contraceptive mechanism of MPU-vas occlusion could be the result of secondary obstruction due to tissue proliferation by MPU irritation after the rupture of the vas deferens.

China↗

PubMed1996

[Combination treatment of late nasopharyngeal carcinoma: an analysis of short-term therapeutic results in 200 cases].

Patients with late nasopharyngeal carcinoma (NPC) were divided into 4 groups, 50 each, treated with different protocols. Group A: radiotherapy plus systemic interlenkin 2 (IL-2), Group B: chemotherapy plus radiotherapy, Group C: chemotherapy plus radiation and IL-2, Group D: radiotherapy alone. Changes in the primary tumor and neck lymph nodes were monitored at 0, 3 and 6 months after treatment. In group A, the primary tumor regression rates (TRR) were 88%, 90% and 92%, and the lymph nodes regression rates (LNR) were 82%, 86% and 88%, respectively. In group B, the TRR were 86%, 88% and 90%, and the LNR were 80%, 84% and 86%, respectively. In group C, the TRR were 88%, 90% and 92%, and the LNR were 82%, 86% and 88%, respectively. In group D, the TRR were 78% 80% and 82%, and the LNR were 76%, 78% and 80%, respectively. The 1-year survival rates in these 4 groups of patients were 92%, 90%, 94% and 82%, respectively. Thus, the therapeutic results are significantly better in the combination treatment groups than those in the group receiving radiotherapy alone. In addition, IL-2 was effective to significantly reduce the occurrence of systemic side effects of radiotherapy and radiotherapy plus chemotherapy.

Adult↗

PubMed1996

[Analysis of population attributable risk of breast cancer in urban and mining districts inhabitants].

In order to study the risk factors associated with female breast cancer, two 1:2 matched case-control studies were conducted from 1986 to 1993 in five cities in Hubei province and from 1991 to 1994 in Pingdingshan coal mining districts in Henan province. The results of multivariate conditional logistic regression analysis showed that history of breast diseases, number of births, age of first birth were major risk factors for breast cancer in urban inhabitants. Their adjusted attributable risks (PARs) were 0.3917, 0.3564, 0.1414 respectively. The combined population attributable risks (PAR) for the three factors was 0.7419. History of breast disease, number of births, menstrual disorder, family history of breast cancer were major risk factors in the Mining districts. Their PARs were 0.1487, 0.4781, 0.1282, 0.0791 respectively. PAR for four factors was 0.6952.

Breast Neoplasms↗

PubMed1996

Research into analgesia by inhaling analgesic.

This article deals with analgesia by inhaling analgesic. According to Chinese medical theories, TCM analgesics were chosen from the literature and folk prescriptions screened and proved by analgesic tests on animals. A reasonable prescription was made up and the drug inhaled. Its analgesic effect was superior to that of dolantin injection (3 mg/kg body weight, intraperitoneal injection). Clinical trials showed its analgesic effect in 3-10 minutes and it lasted for more than 2 hours in over 70% of the cases for a total effective rate of 94.6%. The drug is absorbed quickly and acts directly on the nerve center. Its use is not addictive.

Administration, Inhalation↗

PubMed1996

Human endometrial interleukin-6 (IL-6): in vivo messenger ribonucleic acid expression, in vitro protein production, and stimulation thereof by IL-1 beta.

OBJECTIVE: To investigate human endometrial interleukin-6 (IL-6) expression and effects thereon by IL-1 beta. DESIGN: Prospective. SETTING: Academic medical center. PATIENT(S): Endometrial biopsy specimens from normal volunteers (n = 20) at four specific menstrual stages were used for in vivo study. Endometrial specimens for in vitro study were obtained from patients (n = 19) undergoing gynecologic surgery. INTERVENTION(S): Time and dose-response treatment of endometria with IL-1 beta in tissue culture. MAIN OUTCOME MEASURE(S): In vivo IL-6 messenger RNA expression by Northern analysis and in vitro endometrial IL-6 protein production by assay of the conditioned media. RESULT(S): Midsecretory and late secretory phase endometria expressed more IL-6 messenger RNA than late proliferative phase endometria in vivo. Similarly in vitro, in pg/mg endometrium per hour secretory endometria IL-6 protein production, 25.7 +/- 7.1 (mean +/- SEM), exceeded that of proliferative endometria, 4.7 +/- 1.0. With IL-1 beta treatment, secretory endometria IL-6 protein production exceeded that of proliferative endometria. Interleukin-1 beta stimulated endometrial IL-6 protein production in time- and dose-dependent manners. CONCLUSION(S): Human endometrial IL-6 expression varies with the menstrual cycle, occurs more highly in secretory endometria, and in vitro is stimulated by interleukin-1 beta. Human endometrial IL-6 may therefore mediate some actions of IL-1 beta involving the endometrium and trophoblast.

Adolescent↗

PubMed1996

Presence of free radicals in pigment gallstone in vivo.

OBJECTIVE: To clarify whether free radical, which may play a role in pigment gallstone formation, is present in pigment gallstones in vivo. MATERIALS AND METHODS: Free radical signal of gallstones from 18 patients was detected by electron paramagnetic resonance spectroscopy at 77K under anaerobic condition and in air (control). As soon as the anaerobic determination was finished, the fresh anaerobic sample was exposed to air and stored in a freezer at -20 degrees C. RESULTS: Free radical signal (g = 2.0038) was detected in fresh anaerobic samples containing more than 2% bilirubin compound, and the signal intensity correlated linearly with the content of calcium bilirubinate (r = +0.95, P < 0.0005). During the storage at -20 degrees C and exposure to air, the signal intensity of each anaerobic sample and its control increased gradually, eventually reaching the same stable level. Fe(III) signal intensity was enhanced synchronously and related linearly with free radical signal (r = +0.99, P < 0.0005). CONCLUSIONS: Free radical exists originally in pigment gallstones in vivo, and it may play an important role in pigment gallstone formation. The free radical signal carried by gallstones may be strengthened by the action of oxygen in air on bilirubin. The transition metal ions probably take part in the formation of bilirubin free radical.

Bilirubin↗

PubMed1996

Functional motor innervation of brachial plexus roots. An intraoperative electrophysiological study.

OBJECTIVE: To study the functional motor innervation of C5-T1 nerve roots of the brachial plexus electrophysiologically. PATIENTS AND METHODS: The electrophysiological properties of normal brachial plexus roots and their functional motor innervation were examined in 15 patients with brachial plexus injuries, while the contralateral healthy side C7 root transfer was operated on. Different nerve roots of the brachial plexus were stimulated and maximum amplitudes were recorded in the following 12 muscles: deltoid, biceps, infraspinatus, brachiaradialis, flexor carpi radialis, triceps, extensor digitorum communis, latissimus dorsi, flexor digitorum profundus, abductor brevis, abductor digiti minimi and flexor carpi ulnaris. RESULTS: Functional motor innervation of brachial plexus roots showed the following results: a. C5 mainly forms the axillary nerve to innervate deltoid muscle; b. C6 mainly constructs the musculocutaneous nerve to innervate biceps muscle; c. C7 mainly forms the radial nerve to innervate triceps muscle; d. C8 mainly forms the median nerve to innervate the flexor digitorum muscle; e. T1 mainly forms the ulnar nerve to innervate the intrinsic muscles of the hand. CONCLUSIONS: The brachial plexus is functionally divided into three groups: C5, 6 innervate shoulder and elbow; C8T1 innervate the hand; and C7 innervates shoulder, elbow, wrist and hand. Theoretically, any division of the nerve root alone may not cause damage to limb function.

Adolescent↗

PubMed1996

[Functional motor innervation of brachial plexus roots: an intraoperative electrophysiological study].

The electrophysiological properties of normal brachial plexus and functional motor innervation during the operation of contralateral healthy side C7 transfer were studied different roots of brachial plexus were stimulated and maximum amplitudes were recorded. The results showed functional motor innervation of brachial plexus roots are (1)C5 mainly forms the axillary nerve which innervates deltoid muscle; (2)C5 constructs most of the musculocutaneous nerve fibers which innervate biceps muscle; (3)main component of the radial nerve comes from C7, which innervates triceps muscle; (4)Medial nerve mainly comes from C8, which innervates flexor digitorum muscle; (5)T1 forms most of the ulnar nerve which innervates intrinsic muscle. Based on the relationship between brachial plexus roots and their functional distribution, the particular aspects of functional innervation of C7 as well as the possibility of utilization of other cervical roots were discussed.

Adolescent↗

PubMed1996

[The MRI of cervical lymph node metastasis with malignant tumor of the head and neck].

A prospective diagnostic study on cervical lymph node metastasis from malignant tumor of the head and neck using MRI was performed for 62 cases in order to assess the potential or limitation of MRI for demontrating the pathological cervical lymph node. The double blind method was used in the study. The result reveals MRI has obvious higher sensitivity (85.7%), higher specificity (94.8%) and higher accuracy (89.6%) than palpation. Besides changes in size and shape of the lymph nodes, the intensity of MRI inside lymph nodes was altered showing, mixed hypo-iso-intensity in T1WI and hyper intensity in T2WI. Thus, MRI will probably play an important role as a staging modality in the detection of malignant lymph nodes metastasis.

Adult↗

PubMed1996

[Different proteins in NRCF (nerve regeneration conditioned fluid) from the proximal and distal nerve stump].

80 SD rats were randomly divided into four groups of 20 each; electrostimulation of myeloneure (Group N); electrostimulation of the denervated muscle (Group M); Group C1; and Goup C2. The left lateral sciatic nerve of rats was exercised 2mm in length, and the distal nerve stump of the goup C2 and M and proximal nerve stamp of the Group C1 and N were each sulured into the silcon chamber with the opposile end ligated so that a 10mm was left between the stump and the blind end of chamber. At 3rd, 7th, 14th, 21th and 28th day after nerve transection and tube implantation, the fluid in the silicon tube was aspirated. The samples of fluid were spun and 4 microliters aliguots were taken from the super ratant. Then subjected to the aliquots were taken by phase system and assayed by Gel scan system. The results showed that the Group C2 and M had highly increase in the protein amount. Than that of group C1 and N in the range of 6-10 KD molecular weight. In 29-47 KD molecular weight range, the variety of protein molecular weight in aliguots of the Group N had and obvious increase compared with the group C1. In 16-29 KD, the protein amount in the Group M was more than that in the Group C2.

Animals↗

PubMed1995

Domains with transcriptional regulatory activity within the ALL1 and AF4 proteins involved in acute leukemia.

The ALLI gene, located at chromosome band 11q23, is involved in acute leukemia through a series of chromosome translocations and fusion to a variety of genes, most frequently to A4 and AF9. The fused genes encode chimeric proteins proteins. Because the Drosophila homologue of ALL1, trithorax, is a positive regulator of homeotic genes and acts at the level of transcription, it is conceivable that alterations in ALL1 transcriptional activity may underlie its action in malignant transformation. To begin studying this, we examined the All1, AF4, AF9, and AF17 proteins for the presence of potential transcriptional regulatory domains. This was done by fusing regions of the proteins to the yeast GAL4 DNA binding domain and assaying their effect on transcription of a reporter gene. A domain of 55 residues positioned at amino acids 2829-2883 of ALL1 was identified as a very strong activator. Further analysis of this domain by in vitro mutagenesis pointed to a core of hydrophobic and acidic residues as critical for the activity. An ALL1 domain that repressed transcription of the reporter gene coincided with the sequence homologous to a segment of DNA methyltransferase. An AF4 polypeptide containing residues 480-560 showed strong activation potential. The C-terminal segment of AF9 spanning amino acids 478-568 transactivated transcription of the reporter gene in HeLa but not in NIH 3T3 cells. These results suggest that ALL1, AF4, and probably AF9 interact with the transcriptional machinery of the cell.

Acute Disease↗

PubMed1995

Early Homo and associated artefacts from Asia.

The site of Longgupo Cave was discovered in 1984 and excavated in 1985-1988 by the Institute of Vertebrate Paleontology and Paleoanthropology (Beijing) and the Chongqing National Museum (Sichuan Province). Important finds include very archaic hominid dental fragments, Gigantopithecus teeth and primitive stone tools. Palaeomagnetic analysis and the presence of Ailuropoda microta (pygmy giant panda) suggested that the hominid-bearing levels dated to the earliest Pleistocene. In 1992, joint Chinese-American-Canadian geochronological research corroborated the age using electron spin resonance (ESR) analysis. We report here that the hominid dentition and stone tools from Longgupo Cave are comparable in age and morphology with early representives of the genus Homo (H. habilis and H. ergaster) and the Oldowan technology in East Africa. The Longgupo dentition is demonstrably more primitive than that seen in Asian Homo erectus. Longgupo's diverse and well preserved Plio-Pleistocene fauna of 116 species provide a sensitive contextual base for interpreting the early arrival of the genus Homo in Asia.

Africa, Eastern↗

PubMed1995

Chromosome localization of human genes for clathrin adaptor polypeptides AP2 beta and AP50 and the clathrin-binding protein, VCP.

Clathrin-coated vesicles, involved in endocytosis and Golgi processing, have a surface lattice containing clathrin triskelia and stoichiometric amounts of additional components termed "assembly proteins," or APs. The AP form at the plasma membrane, AP2, is composed of two large subunits of 100-115 kDa, denoted AP2 alpha and AP2 beta, a medium chain of 50 kDa, designated AP50, and a small chain. We have determined human chromosomal locations of genes for a large AP2 beta (CLAPB1) and a medium (CLAPM1) AP subunit and of a novel clathrin-binding protein, VCP, that binds clathrin simultaneously with APs. Chromosomal in situ hybridization of a human genomic clone demonstrated that the CLAPM1 gene mapped to chromosome region 3q28. The gene for the CLAPB1 large subunit was mapped to 17q11.2-q12 by PCR amplification of an AP2 beta fragment from a panel of rodent-human hybrid DNAs. To map the human VCP sequence, a human-specific probe was made by RT-PCR of human mRNA using oligonucleotide primers from conserved regions of the porcine sequence. The amplified human fragment served as probe on Southern blots of hybrid DNAs to determine that the human VCP locus maps to chromosome region 9pter-q34.

Adaptor Protein Complex 2↗

PubMed1995

Cleavage of poly(ADP-ribose) polymerase by interleukin-1 beta converting enzyme and its homologs TX and Nedd-2.

The proteolytic cleavage of poly(ADP-ribose) polymerase (PARP) is an early biochemical event, which occurs during apoptosis. A recent study suggested that PARP cleavage can be mediated by a novel cytosolic protease (prICE) that resembles interleukin-1 beta converting enzyme (ICE), but cannot be mediated by ICE itself (Lazebnik, Y.A., Kaufmann, S.H., Desnoyers, S., Poirier, G.G., and Earnshaw, W.C. (1994) Nature 371, 346-347). We have used a COS cell co-transfection assay to investigate if ICE or any known ICE-like protease is active in PARP cleavage within the cell. Here we report that co-expression of human PARP with human ICE, or the ICE homologs TX and Nedd-2, resulted in a cleavage of PARP identical to that observed in apoptotic cells. Experiments with purified recombinant human ICE indicated that PARP polypeptide can be specifically cleaved in vitro by ICE in a time- and enzyme concentration-dependent manner. PARP cleavage, however, requires a 50-100-fold higher ICE concentration than does processing of the interleukin-1 beta precursor at an equivalent substrate concentration. The abilities of ICE, TX, and Nedd-2, when expressed at high intracellular concentrations, to cleave PARP are consistent with their induction of apoptosis in transfected cells.

Amino Acid Sequence↗

PubMed1995

A novel human protease similar to the interleukin-1 beta converting enzyme induces apoptosis in transfected cells.

We have identified a novel cDNA encoding a protein (named TX) with > 50% overall sequence identity with the interleukin-1 beta converting enzyme (ICE) and approximately 30% sequence identity with the ICE homologs NEDD-2/ICH-1L and CED-3. A computer homology model of TX was constructed based on the X-ray coordinates of the ICE crystal recently published. This model suggests that TX is a cysteine protease, with the P1 aspartic acid substrate specificity retained. Transfection experiments demonstrate that TX is a protease which is able to cleave itself and the p30 ICE precursor, but not to generate mature IL-1 beta from pro-IL-1 beta. In addition, this protein induces apoptosis in transfected COS cells. TX therefore delineates a new member of the growing Ice/ced-3 gene family coding for proteases with cytokine processing activity or involved in programmed cell death.

Amino Acid Sequence↗

PubMed1995

Interleukin-1 beta converting enzyme requires oligomerization for activity of processed forms in vivo.

Interleukin-1 beta converting enzyme (ICE) is composed of 10' (p10) and 20 kDa (p20) subunits, which are derived from a common 45 kDa precursor. Recent crystallographic studies have shown that ICE exists as a tetramer (p20/p10)2 in the crystal lattice. We provide evidence that the p10 and p20 subunits of ICE associate as oligomers in transfected COS cells. Using intragenic complementation, we show that the activity of a p10/p10 interface mutant defective in autoprocessing can be restored by co-expression with active site ICE mutants. Different active site mutants can also complement each other by oligomerization to form active ICE. These studies indicate that ICE precursor polypeptides may associate in different quaternary structures and that oligomerization is required for autoprocessing. Furthermore, integenic complementation of active site mutants of ICE and an ICE homolog restores autoprocessing activity, suggesting that hetero-oligomerization occurs between ICE homologs.

Amino Acid Sequence↗