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Biomedical subjects

Q Yang

Publications and source records attributed to Q Yang.

At least 451 records · Page 25Linked to original sources
PubMed1994

[Significance of anamnesis and clinical findings for diagnosis of acute appendicitis. Acute Abdominal Pain Study Group].

UNLABELLED: Acute appendicitis raises considerable diagnostic difficulties. This is proven by rates of negative appendectomies that sometimes extent 30%. In order to find reasons for this we tested 211 patients findings for diagnostic relevance. METHOD: Within the European Community--Acute Abdominal Pain Survey, a study to support diagnosis in acute abdominal pain, 1254 patients were seen in the six participating German hospitals. 16.8% had appendicitis. History data and physical findings were tested for positive and negative predictive value (PPV/NPV), sensitivity and specificity (SEN/SPE). RESULTS: We had 15% negative appendectomies and 16% perforated appendicies. Only few of the parameters tested show a PPW significantly higher than the prior probability of appendicitis: (PPV/NPV/SEN/SPE in %) rebound tenderness 39/63/91/80, tenderness in the right lower quadrant 36/82/95/70, pain right lower quadrant at presentation 34/77/94/70, onset of pain right lower quadrant 29/49/88/75, rigidity 28/9/84/95, guarding 26/43/87/76. All other parameters had a lower PPV. The combination of three parameters leads to maximal PPV of 85%. CONCLUSION: Very few symptoms are helpful in diagnosing appendicitis: the pain related symptoms (spontaneous pain, tenderness and rebound tenderness, guarding) and the history of the pain hint at an appendicitis. A structured and complete medical history and physical examination focussing on these few symptoms, a systematic combination of these and possibly ultrasonography will improve diagnostic accuracy.

Abdomen, Acute↗
PubMed1994

[A comparative study on anti-ulcer action of unprepared and calcined oyster shell].

On experimental gastric ulcer models induced by 0.6mol/L HCl, ethyl alcohol or ligation of the pylorus, the preventive effects of unprepared oyster shell, calcined oyster shell 1(900 degrees C, 1h), calcined oyster shell 2(350 degrees C, 8h) were compared in Wistar rats. Results showed that antagonistic effects of calcined oyster shell 1 to the drug pathogenesis of peptic ulcer and the incidence of peptic ulcer after ligation of the pylorus were markedly greater.

Animals↗
PubMed1994

[A longitudinal study on maternal-fetal transfer of antibody against poliomyelitis].

A study on antibody distribution and titer against poliovirus in 67 mothers and their 60-day-old new-born babies was carried out in Shi-yan, Hubei Province. The positive rates and the geometric mean titers of antibodies against Types I-II poliovirus in mothers were 98.58%, 1:32.67; 95.5%, 1:30.07; 92.5%, 1:14.58, respectively. In their 60-day-old babies, the antibody positive rates and geometric mean titers fell obviously: they were 34.3%, 1:2.45; 34.3%, 1:2.22; and 14.9%, 1:1.34, respectively. The authors suggest to immune those neonates (OPV zero), or to immune those mothers beginning from 28 weeks of pregnancy in order to raise the antibody titer and protect their babies during the early days.

Antibodies, Viral↗
PubMed1994

[The supplementary effect of consulting vaccination in expanded program on immunization (EPI)].

This study was carried out in 420 of children aged 12-24 months in two counties of Gansu Province, China. The result showed that general consulting rate was 30.24% in county or township hospital. The average consulting time was 2.14. A formula was designed K = R x C (1-V) for detecting the effect of consulting vaccination in EPI. The maximum supplementary coefficients of initial immunization of outpatient children for the vaccines were as follows: BCG 0.3024, TOPV-3 0.0953, DPT-3 0.0929, MV 0.0643. And once immunization were BCG 0.3024, TOPV 0.2643, DPT 0.2381, MV 0.0643. The study also explores the supplementary effect of consulting vaccination in different vaccination times and immunization coverages.

Child, Preschool↗
PubMed1994

[Pharmacological studies of nin jion pei pa koa].

The results showed that King To Nin Jiom Pei Pa Koa had significant cough relieving and sputum removing effects. It also had an evident effect on relieving asthma in vivo and in vitro. In four acute or sub-acute inflammatory models, the anti-inflammatory effect was marked.

Animals↗
PubMed1994

[Blood gas and acid-base equilibrium in normal pregnancy and pregnancy with fetal distress by vaginal delivery or cesarean section].

Blood gas and acid-base assessment of maternal dorsalis pedis artery and umbilical artery and vein was carried out immediately after delivery in 46 cases of normal term pregnancy and 41 cases of pregnancy with fetal distress (FD). Blood gas and acid-base equilibrium differences between vaginal delivery and cesarean section were studied. The results showed a low BE value (< -3mmol/L) in maternal artery of both groups, and that the other parameters were all within normal range, not being different between the normal pregnancy and FD group. Blood gas assaying of umbilical veins of the 2 groups also showed no difference. In comparison with the normal pregnant group, the FD group yielded significantly decreased values of pH, PO2 and O2Sat in umbilical artery but significantly increased PCO2 (P < 0.05). Women of both groups delivered vaginally had milder metabolic acidosis and slighter hypoxia than those delivered by cesarean section. Marked fetal acidosis and low Apgar score were more commonly seen in the FD group. These indicated that to delay labor to near term and to perform cesarean section for relieving fetal distress is advisable.

Acid-Base Imbalance↗
PubMed1993

Effects of pH on the activity of the human red cell glucose transporter Glut 1: transport retention chromatography of D-glucose and L-glucose on immobilized Glut 1 liposomes.

The facilitative glucose transporter Glut 1 from human red cells was reconstituted into liposomes that were size-fractionated and immobilized in an octyl sulfide-Sephacryl S-1000 column. D-[14C]Glucose was eluted later than L-[3H]glucose from the Glut 1 liposome column (by delta V microliters), apparently because the D-glucose was transported through the liposomes. The corresponding difference with protein-free liposomes was delta V0. The Glut 1 transport retention chromatographic effect, delta VG = delta V - delta V0, 40-50 microliters at pH 7, was nearly constant at pH 6-10 (400 mM NaCl, 23 degrees C, internal liposome volume approximately 240 microliters) but decreased steeply below pH 5 to become zero at pH 3.6. The decrease corresponded to a pKa of approximately 4.4 and was partly reversible above pH 4.7. Similarly, glucose exchange by non-immobilized freeze-thawed proteoliposomes with Glut 1 slowed down drastically as the pH was lowered from pH 5.5 to 4; and octyl glucoside-solubilized Glut 1 lost half its activity in 15 min at pH 4.5 (low ionic strength, 2 degrees C) as shown by glucose exchange determinations at pH 7.2 The results suggest that Glut 1 is inactivated at low pH upon protonation of carboxylate groups of pKa approximately 4.4-4.8. It seems likely that carboxylate groups form hydrogen bonds to transported D-glucose.

Carrier Proteins↗
PubMed1993

Trypsin display on the surface of bacteriophage.

The gene III and VIII-encoded coat proteins (pIII and pVIII) from bacteriophage M13 have been fused to the C terminus of the serine protease, trypsin (Tsn). The genes encoding the fusions were then inserted directly into M13mp18 to create vectors which expressed both the Tsn-coat protein hybrids and the wild-type (wt) coat proteins. Immunoblot analysis confirmed that the bacteriophage express Tsn on their surface. Isolated fusion phage possess kinetic parameters which approximate those of the wt enzyme. An endogenous Escherichia coli protease inhibitor, ecotin, copurifies with the Tsn phage. Immobilized ecotin can be used to selectively bind bacteriophage which express Tsn::pIII fusion proteins.

Animals↗
PubMed1993

Cloning and expression of PTP-PEST. A novel, human, nontransmembrane protein tyrosine phosphatase.

The polymerase chain reaction was used to amplify protein tyrosine phosphatase (PTPase)-related cDNA from a template of total RNA isolated from human skeletal muscle. A novel PTPase, which we term PTP-PEST, was detected by this method. The polymerase chain reaction fragment was used to screen two different HeLa cell libraries to obtain full length cDNA clones. The cDNA predicts a protein of 510 amino acids, approximately 60 kDa, that does not contain an obvious signal sequence or transmembrane segment suggesting it is a nonreceptor type enzyme. The PTPase domain is located in the N-terminal portion of the molecule and displays approximately 35% identity to other members of this family of enzymes. The C-terminal segment is rich in Pro, Glu, Asp, Ser, and Thr residues, possessing features of PEST motifs which have previously been identified in proteins with very short intracellular half-lives. The protein was expressed in Escherichia coli as a fusion product with glutathione S-transferase. Intrinsic activity was demonstrated in vitro against a variety of phosphotyrosine-containing substrates including BIRK, the autophosphorylated cytoplasmic kinase domain of the insulin receptor beta subunit. It did not dephosphorylate phosphoseryl-phosphorylase a. PTP-PEST mRNA is broadly distributed in a variety of cell lines. Stimulation of human rhabdomyosarcoma A204 cells, a transformed muscle line, with insulin led to an approximately 4-fold induction of PTP-PEST mRNA within 36 h.

Adult↗
PubMed1993

Etofibrate increases binding of low and high density lipoprotein to human platelets of patients with type II hyperlipoproteinemia.

Previous work suggested an influence of etofibrate, a diester of nicotinic acid and clofibric acid, on lipoprotein receptors. Besides its beneficial effects on plasma lipoprotein levels of decrease in total cholesterol, LDL-cholesterol and triglycerides and increase in HDL-cholesterol, etofibrate was shown to inhibit platelet function. In order to further evaluate platelet-lipoprotein interactions, the effects of etofibrate on plasma lipids and lipoproteins on the specific binding of normal [111In]LDL and [111In]HDL onto platelets as well as its effect on platelet function were evaluated in 8 patients affected by Type II hyperlipoproteinemia (HLP). In all patients binding was saturable and indicated high affinity binding sites capable of binding 927 +/- 233 ng protein of [111In]LDL/10(9) platelets (Kd 12 +/- 3 micrograms protein/ml) and 1496 +/- 435 ng protein of [111In]HDL/10(9) platelets (Kd 14 +/- 3 micrograms protein/ml). The capacity of native LDL (HDL) to displace bound [111In]LDL ([111In]HDL) by half (IC50) amounted to 22 +/- 9 micrograms protein/ml (26 +/- 8 micrograms protein/ml). Following a 6-week treatment period with etofibrate (500 mg twice daily), decrease in plasma total cholesterol, LDL-cholesterol and apolipoprotein (apo) B and increase in HDL-cholesterol and apo AI was correlated to a significant (P < 0.01) increase in LDL- as well as HDL-receptor binding. The platelet binding capacity increased to 1085 +/- 212 ng protein/10(9) platelets (Kd 8 +/- 3 micrograms protein/ml) for [111In]LDL and to 1867 +/- 266 ng protein/10(9) platelets for [111In]HDL (Kd 11 +/- 3 micrograms protein/ml). Platelet function studies demonstrated significantly (P < 0.01) reduced platelet aggregation in response to ADP and thromboxane formation after 6 weeks of etofibrate therapy. These findings in patients with HPL Type II indicate in vivo upregulation of specific [111In]LDL as well as [111In]HDL binding sites on human platelets associated with reduced platelet activation following etofibrate therapy.

Adult↗
PubMed1993

Acetylsalicylic acid (ASA) protects the prostaglandin-cAMP-system of human hypernephroma cells against irradiation-induced alterations.

There is abundant evidence that inhibitors of prostaglandin (PG) biosynthesis might increase the radioresponse of certain tumour cells. This study investigated specific PG binding sites, eicosanoid production as well as intracellular cAMP levels in cultured human hypernephroma cells derived from 11 patients upon nephrectomy. Scatchard analyses of the binding data revealed specific PGE1-, PGE2- as well as PGI2-binding sites (PGE1: Bmax = 755 +/- 206 fmol mg-1 protein, Kd = 3.7 +/- 2.7 nM PGE2: Bmax = 494 +/- 221 fmol mg-1 protein, Kd = 4.2 +/- 2.5 nM; PGI2: Bmax = 693 +/- 164 fmol mg-1 protein, Kd = 6.0 +/- 4.5 nM). Significant (P < 0.01) increase in PG binding sites expressed on human hypernephroma cells (PGE1: Bmax = 1084 +/- 303 fmol mg-1 protein, Kd = 2.8 +/- 1.3 nM; PGE2: Bmax = 663 +/- 309 fmol mg-1 protein, Kd = 2.2 +/- 1.5 nM; PGI2: Bmax = 1021 +/- 391 fmol/protein, Kd = 4.2 +/- 3.6 nM) and inhibition of PG biosynthesis (TXB2: -82.5%, PGE2: -87.5%. PGD2: -80.6%, PGF2: -81.3%) were found after acetylsalicylic acid (ASA)-treatment (0.5 mg 10(-6) cells for 24 h). Following irradiation (60Co, 1.0 Gy/min-1 over 10(min), PG binding sites (PGE1: Bmax = 266 +/- 153 fmol mg-1 protein, Kd = 5.0 +/- 5.0 nM; PGE2: Bmax = 148 +/- 66 fmol mg-1 protein, Kd = 4.7 +/- 3.6 nM; PGI2: Bmax = 325 +/- 194 fmol mg-1 protein, Kd = 6.8 +/- 7.1 nM) were significantly (P < 0.01) diminished. However, irradiation had no significant effect on PG binding sites in ASA-pretreated cells (PGE1: Bmax = 699 +/- 240 fmol mg-1 protein, Kd = 3.5 +/- 1.8 nM; iloprost: Bmax = 766 +/- 452 fmol mg-1 protein, Kd = 3.2 +/- 2.2 nM). Although there was no significant difference in the basal values for cAMP between control and ASA-treated group cells, the PG-induced cAMP-production was less pronounced in the control group. Taken together, the findings suggest that ASA may modify the radioresponse of cultured human hypernephroma cells by preventing the decrease of PG binding sites induced by irradiation.

Alprostadil↗
PubMed1993

Analysis of the terminal repeat binding abilities of mutant adeno-associated virus replication proteins.

The adeno-associated virus (AAV) Rep78 and Rep68 proteins play essential roles in viral DNA replication, trans activation of viral gene expression, and suppression of oncogene-mediated cellular transformation. By using an extensive set of linker insertion and deletion mutations in the replication gene, we mapped the regions of the Rep78 protein that mediate binding to the AAV origin of replication in vitro. Deletions that removed amino acid codons 25 to 62, 88 to 113, 125 to 256, and 346 to 400 abolished binding. Alterations in several other regions of the protein affected the binding affinity of the mutant proteins. All of the mutant proteins that support AAV DNA replication or p40 trans activation bound to the terminal repeat sequence, thus verifying the importance of binding for these functions. Several mutant rep genes that failed to suppress oncogene-mediated cellular transformation produced proteins that were capable of binding to the AAV terminal repeat sequences.

DNA Mutational Analysis↗
PubMed1993

Co-activation of sternocleidomastoid muscles during maximum clenching.

In an attempt to determine the degree of co-activation present in selected cervical muscles during clenching, we instructed 12 male subjects to produce four brief maximum voluntary contraction (MVC) efforts (clenching) in a position of maximum intercuspation. Surface EMG activity was recorded bilaterally from the masseter and sternocleidomastoid (SCM) muscles. The contraction level for the SCM during clenching was reported as a percentage of the SCM's maximum activity achieved during maximum neck flexion against resistance. All EMG signals for the masseter and SCM were converted to a true RMS voltage signal and digitized at a 100-Hz sampling rate. Mean peak EMG voltage levels were determined for the activity recorded during each brief MVC task. All subjects demonstrated co-activation of the SCM during strong abrupt clenching efforts. The mean levels (+/- S.D.) of SCM activity were 11.8 +/- 9.6% (right) and 14.2 +/- 9.4% (left) of the MVC capacity. Fifty percent of masseter activity was required to achieve 5% activity of the SCM bilaterally, and there was a progressive development of the SCM co-activation which paralleled the masseter activation.

Adult↗
PubMed1993

Sternocleidomastoid muscle inhibition induced by trigeminal stimulation.

Among numerous reports of anatomical and functional coupling between the trigeminal and cervical systems is the demonstration that the sternocleidomastoid (SCM) muscles may become activated along with the masseter muscles during forceful abrupt biting maneuvers. Whether the co-activated SCM is also inhibited by stimuli that produce masseter inhibition is not known. This study evaluated the SCM for the presence of inhibition during mechanically-elicited (chin or forehead tap) and electrically-elicited (anterior maxillary gingiva stimulation) inhibition of the masseter muscle in ten healthy men. Surface EMG data were recorded bilaterally from the masseter and SCM muscles. The data for each muscle were converted to ratios of the pre-stimulus maximum voluntary contraction activity for each subject and averaged across subjects. Means of these percentages were determined at several defined pre- and post-stimulus intervals. The results indicate that masseter inhibition was clearly elicited by the electrical and both forms of mechanical stimulation. SCM co-inhibition could be evoked by electrical and chin tap stimulation but not by forehead tap. The responses to these stimuli varied among subjects, from trial to trial, and within subjects depending on the experimental condition. The fact that it was possible for this co-inhibition to be evoked is presented as further indication of the functional coupling of the trigeminal and cervical systems.

Adult↗
PubMed1993

[Studies on ras P21 expression and mutation at 12th codon of C-Ha-ras oncogene in squamous cell carcinoma of the larynx].

Monoclonal antibody directed against the ras oncogene product P21 was used to evaluate P21 expression in 42 cases of tumors of the larynx. The results showed that there was a higher level of ras P21 expression in squamous cell carcinoma of the larynx (LSCC) than in papilloma of the larynx (LP) and the normal tissues adjacent to LSCC, P < 0.05. We had also detected G-->T mutation at codon 12 of Ha-ras oncogenes in LSCC using polymerase chain reaction (PCR). PCR products were hybridized with mutation-specific oligonucleotide probes. Thirty per cent (6/20) LSCC cases harbored this mutation. But G-->T mutation was absent in 3 LP and 5 normal tissues adjacent to LSCC. A relationship may exist between the presence of G-->T mutation and Jakobsson's malignant grading result. All of 6 LSCC cases containing G-->T mutation were in high malignant grading group, P < 0.05. This study implicates that overexpression of ras P21 and presence of Ha-ras G-->T mutation may be one of the molecular mechanisms of maintenance of malignancy and progression of LSCC.

Base Sequence↗