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Biomedical subjects

M Sha

Publications and source records attributed to M Sha.

At least 19 recordsLinked to original sources
PubMed2001

Causes of airway obstruction during cuffed oropharyngeal airway use.

This study investigated the cause for needing airway maneuvers to maintain a patent airway during the use of cuffed oropharyngeal airway (COPA). Twenty adult patients (29.4+/-6.8 years-old, ASA 1-2) scheduled for minor gynecological surgery who required brief manipulations of the airway despite COPA use following the manufacture's guidelines, were enrolled in this study. To obtain airway patency, 15 patients required only the head-tilt maneuver. In eight of the 15 patients, the laryngeal inlet was opened partially (n=4) or completely (n=4). Despite lifting the epiglottis, the laryngeal inlet was incomplete at the level of pharyngeal view. The patency of the laryngeal inlet was decided by the extent of the distance between the posterior pharyngeal wall and the lateral glossoepiglottic fold, which was made by hyoid bone. In the other seven patients, the head-tilt maneuver elevated the epiglottis and completely opened the laryngeal inlet. Five patients required both the jaw-thrust and head-tilt maneuver. Of these patients lifting the epiglottis was incomplete in three and the laryngeal inlet was partially collapsed in one even after the airway manipulations. The airways in these three patients, however, became patent after manipulations despite the persisting partial obstruction.

Adult↗
PubMed2001

The 100-kda U5 snRNP protein (hPrp28p) contacts the 5' splice site through its ATPase site.

To identify splicing factors in proximity of the 5' splice site (5'SS), we followed a crosslinking profile of site-specifically modified, photoreactive RNA substrates. Upon U4/U5/U6 snRNP addition, the 5'SS RNA crosslinks in an ATP-dependent manner to U6 snRNA, an unidentified protein p27, and the 100-kDa U5 snRNP protein, a human ortholog of an ATPase/RNA helicase yPrp28p. The 5'SS:hPrp28p crosslink maps to the highly conserved TAT motif in proximity of the ATP-binding site in hPrp28p. We propose that hPrp28p acts as a helicase to unwind the 5'SS:U1 snRNA duplex, and at the same time as a 5'SS translocase, which, upon NTP-dependent conformational change, positions the 5'SS for pairing with U6 snRNA within the spliceosome. This repositioning of the 5'SS takes place regardless of whether the 5'SS is originally duplexed with U1 snRNA.

Adenosine Triphosphatases↗
PubMed2001

Cardiac arrest associated with use of an argon beam coagulator during laparoscopic cholecystectomy.

We describe a cardiac arrest during use of an argon beam coagulation (ABC) system in an 82-yr-old woman having laparoscopic cholecystectomy under general and epidural anaesthesia. Intra-abdominal pressure (IAP) was controlled to less than 12 mm Hg during a carbon dioxide gas pneumoperitoneum and at first the operation was uneventful. When the ABC system (gas flow 6 litre min(-1)) was used to control local bleeding in the liver bed abdominal pressure increased rapidly to over 20 mm Hg and, 1 min later, the end-tidal carbon dioxide decreased to zero, followed by bradycardia and cardiac arrest. At once, an emergency laparotomy was performed and resuscitation begun. A mill-wheel murmur was heard on auscultation, leading to suspicion of argon gas embolism. Fortunately, recovery was completed with no neurological deficit. Anaesthesiologists should consider showed that argon gas embolism can occur with the ABC system during laparoscopic surgery.

Aged↗
PubMed2001

[Pulmonary complications following laparoscopic cholecystectomy in patients with abnormal spirometry].

The purpose of this study was to determine the incidence of postoperative pulmonary complications (PPC) and the value of preoperative spirometry to predict PPC after laparoscopic cholecystectomy. Sixty-four of 1372 patients (8%) showed abnormal spirometry data. One out of 1372 patients developed aspiration pneumonia. The patient had high risk factors for serious PPC such as ASA physical status 4.84 y/o, longer anesthesia duration (230 min), multiple brain infarction and low albuminemia. Thirty to 39% of patients with abnormal spirometry showed less severe PPC such as atelectasis, lung collapse and pleural effusion, and incidence was the similar with normal lung function patients. Postoperative blood gas analysis showed a slight increase in arterial carbon dioxide tension during oxygen therapy. However, none of the patients with abnormal spirometry and less severe PPC developed manifest PPC (pneumonia, respiratory failure). Less severe PPC disappeared within second to third postoperative days. We conclude that laparoscopic intervention significantly reduced the incidence of severe PPC and the preoperative spirometry was not recommended in patients with no pulmonary symptoms.

Aged↗
PubMed2001

[Resolution of overlapping chromatographic peaks by radial basis function neural network].

A new algorithm-resolution of overlapping chromatographic peaks by radial basis function neural network(RBFNN) is presented. A two-phase genetic algorithm(GA) which has robustness and random globe optimization is used to train RBFNN so that it has the ability on the resolution of overlapping chromatographic peaks. The two-phase genetic algorithm involves two procedures: training structure and optimizing parameter. The first procedure uses GA to train the architectures of RBFNN, the second procedure uses gradient descent to train the center(tR) and the width(sigma) of RBFNN. The alternate use of these two procedures makes the network having the ability to learn structure, therefore makes itself adaptable to resolution of the chromatographic peaks with unknown number of components. The method proposed here needs no artificial interference, not only has it robustness and globalism, but also the ability of accurate resolution to completely overlapped chromatographic peaks. The simulation experiments show that this method is more accurate than other methods.

Algorithms↗
PubMed2000

The protooncogene TCL1 is an Akt kinase coactivator.

Human T cell prolymphocytic leukemia can result from chromosomal translocations involving 14q32.1 or Xq28 regions. The regions encode a family of protooncogenes (TCL1, MTCP1, and TCL1b) of unknown function. In yeast two-hybrid screening, we found that TCL1 interacts with Akt. All TCL1 isoforms bind to the Akt pleckstrin homology domain. Both in vitro and in vivo TCL1 increases Akt kinase activity and as a consequence enhances substrate phosphorylation. In vivo, TCL1 stabilizes the mitochondrial transmembrane potential and enhances cell proliferation and survival. In vivo, TCL1 forms trimers, which associate with Akt. TCL1 facilitates the oligomerization and activation of Akt. Our data show that TCL1 is a novel Akt kinase coactivator, which promotes Akt-induced cell survival and proliferation.

Animals↗
PubMed2000

[A nationwide survey of anesthesia for laparoscopic and thoracoscopic surgeries].

This is the report the first nationwide survey of anesthetic management for laparoscopic and thoracoscopic surgeries. We mailed a questionnaire to anesthetists of 133 hospitals in Japan and 74 completed questionnaires were returned. The number of intra-abdominal and thoracic surgical procedures has been increasing. General anesthesia was used in all cases for endoscopic surgery. The double lumen tube was selected in 79% of patients with pneumothorax for the endobronchial intubation. Patients for the laparoscopic cholecystectomy (LC) were given various types of anesthetics. Thirty-two percent of patients who underwent LC was anesthetized with inhalation anesthetics combined with epidural anesthesia for the early ambulance and postoperative pain control. The maximum length of time for LC surgery was 12.5 hr. Complications related to laparoscopic surgery included bile duct injuries in 72 patients, postoperative bleeding in 32 patients, vascular injuries in 29 patients, pneumothorax in 26 patients, bronchial intubation in 17 patients, gas embolism in 11 patients, bowel injuries in 9 patients and postoperative ileus in 7 patients. Administering anesthesia for endoscopic procedures requires precise knowledge of the surgical procedures, physiologic changes and complications of the pneumoperitoneum, and one lung ventilation.

Anesthesia↗
PubMed1999

Competitive lipase-catalyzed ester hydrolysis and ammoniolysis in organic solvents; equilibrium model of a solid-liquid-vapor system.

Enzymatic ester hydrolysis and ammoniolysis were performed as competitive reactions in methyl isobutyl ketone without a separate aqueous phase. The reaction system contained solid ammonium bicarbonate, which dissolved as water, ammonia, and carbon dioxide. During the reaction an organic liquid phase, a vapor phase, and at least one solid phase are present. The overall equilibrium composition of this multiphase system is a complex function of the reaction equilibria and several phase equilibria. To gain a quantitative understanding of this system a mathematical model was developed and evaluated. The model is based on the mass balances for a closed batch system and straightforward relations for the reaction equilibria and the solubility equilibria of ammonium bicarbonate, the fatty acid ammonium salt, water, ammonia, and carbon dioxide. For butyl butyrate as a model ester and Candida antarctica lipase B as the biocatalyst this equilibrium model describes the experiments satisfactorily. The model predicts that high equilibrium yields of butyric acid can be achieved only in the absence of ammoniolysis or in the presence of a separate water phase. However, high yields of butyramide should be possible if the water concentration is fixed at a low level and a more suited source of ammonia is applied.

Ammonia↗
PubMed1999

[Perioperative pulmonary embolism: a nationwide survey in Japan].

Pulmonary embolism is a leading cause of death and morbidity in the perioperative period. To obtain a contemporary overview of the epidemiology of acute pulmonary embolism, a questionnaire was mailed to anesthesia department chair-persons at 179 hospitals in Japan. The 158 cases were reported from the 88 hospitals. The cause of embolism was thromboembolism 127, gas 13, fat 9, amniotic fluid 4 and tumor 3. The mortality rate for patients with thromboembolism was high (29%). Dyspnea was the most frequent symptom (60%) and hypotension was the most frequent clinical sign (54%). The signs which suggested massive pulmonary embolism, such as hypotension, cyanosis (53%), syncope (39%) and cardiac arrest (29%) were frequently seen. Most of the pulmonary embolisms occurred during the operation and within 7 days after the operation. The high risk factors associated with thromboembolism were age, malignancy, obesity and the type of surgery performed. Treatment performed included anticoagulation 81%, catecholamine infusion 66%, thrombolysis 14%, surgical embolectomy 8% and extra-corporeal circulation 4%. This study indicates that the perioperative pulmonary embolism is still associated with high mortality and requires an immediate diagnosis and intensive therapy.

Adolescent↗
PubMed1999

[Determination of columbianetin, columbianetin acetate and osthol in Angelica pubescens Maxim. f. biserrata Shan et Yuan by HPLC].

OBJECTIVE: To develop a method for the determination of columbianetin, columbianetin acetate and osthol in Angelica pubescens f. biserrata METHOD: HPLC method, ODS column (6.0 mm x 150 mm) with a mobile phase of methanol-acetonitrile-0.025 mol.L-1 phosphoric acid (32:20:48), and wave length detection at 320 nm. RESULT AND CONCLUSION: The method can be used for the quality control of raw medicinal materials.

Angelica↗
PubMed1999

[Determination of gallic acid in garden burnet by HPLC].

OBJECTIVE: To establish a HPLC method for the determination of gallic acid in garden burnet. METHOD: The sample was extracted with methanol under ultrasonic management for 25 min. Chromatographic conditions: Shimadzu LC-6A with SPD-6AV detector at 270 nm and auto injector SIL-6A, methanol-0.025 mol/L phosphoric acid(15:85) as the mobile phase. Shin-pack CLC-ODS column(6.0 mm x 15 mm). RESULT: Gallic acid in garden burnet was baseline separated and determined. The average content was 0.22%, recovery rate 97.4% and relative standard deviation 1.3%. CONCLUSION: Simple, rapid and accurate, the method provides new indexes for quality control of Garden Burnet.

Chromatography, High Pressure Liquid↗
PubMed1998

Probing of the spliceosome with site-specifically derivatized 5' splice site RNA oligonucleotides.

We have developed a site-specific chemical modification technique to incorporate a photoreactive azidophenacyl (APA) group at designated internal positions along the RNA phosphodiester backbone. Using this technique, we have analyzed interactions of the 5' splice site (5'SS) RNA within the spliceosome. Several crosslinked products can be detected within complex B using the derivatized 5'SS RNAs, including U6 snRNA, hPrp8p, and 114-, 90-, 70-, 54-, and 27-kDa proteins. The 5'SS RNAs derivatized at intron positions +4 to +8 crosslink to U6 snRNA, confirming the previously reported pairing interaction between these sequences. hPrp8p and p70 are crosslinked to the 5'SS RNA when the APA is placed within the 5' exon. Finally, a set of unidentified proteins, including p114, p54, and p27, is detected with the 5'SS RNA derivatized at intron positions +4 to +8. Introduction of the bulky APA group near the 5'SS junction (positions -2 to +3) strongly interferes with complex B formation and thus no APA crosslinks are observed at these positions. Together with our earlier observation that hPrp8p crosslinks to the GU dinucleotide at the 5' end of the intron, these results suggest that the inhibitory effect of APA results from steric hindrance of the hPrp8p:5'SS interaction. Unexpectedly, thio-modifications within the region of the 5'SS RNA that is involved in base pairing to U6 snRNA strongly stimulate complex B formation.

Allosteric Site↗
PubMed1998

Preoperative nocturnal desaturations as a risk factor for late postoperative nocturnal desaturations.

Severe postoperative hypoxaemia during sleep may increase the risk of postoperative cardiovascular complications. We hypothesized that the severity of hypoxic episodes after surgery are related to the presence of preoperative sleep-disordered breathing (SDB). We tested this hypothesis in a multicentre study designed to elucidate the major risk factors for development of postoperative nocturnal desaturations. We performed overnight oximetry before operation and for one night between the second and fourth day after operation in 80 patients undergoing major surgery. We calculated oximetry variables such as oxygen desaturation index (ODI), defined as the number of oxygen desaturations exceeding 4% below baseline, percentage time spent at SpO2 < 90% (CT90, %) and lowest SpO2 value. After operation, although the change in ODI was not significant (P = 0.34), deterioration in CT90 and lowest SpO2 values were significant (P = 0.036 and P = 0.007, respectively). Multivariate analysis of possible risk factors for postoperative desaturations revealed that preoperative hypoxaemia and apnoea witnessed by others were highly correlated with postoperative hypoxaemia.

Adult↗
PubMed1998

[Determination of hyperin in Sanguisorba Officinalis L. by high performance liquid chromatography].

An HPLC method for the determination of hyperin in Sanguisorba officinalis L. was investigated. 0.5 g of dried powdered crude drug was weighed accurately in a 50 mL volumetric flask added with 40 mL methanol, supersonicated for 30 min and then made up to volume with methanol. The sample solution was separated on a Shim-pack ODS column(6.0 mm i.d. x 150 mm, 5 microns) with methanol-0.025 mol/L phosphoric acid (adjusted to pH 3.0 by using triethylamine)(50:50) as the mobile phase and detected at UV-370 nm. Calibration curve of hyperin was obtained for the concentration range of 0.046-0.2 microgram. The corresponding regression equation was Y = 154 x 10(4) X-0.28 x 10(4), r = 0.9998. The recovery was 98.7% and relative standard deviation was 1.9%. The results showed that this method is simple, specific and accurate.

Analgesics↗
PubMed1997

Baculovirus-mediated expression and characterization of the full-length murine DNA methyltransferase.

The original cDNA sequence reported for the murine DNA methyltransferase (MTase) was not full length. Recently, additional cDNA sequences have been reported that lie upstream of the original and contain an extended open reading frame with three additional ATGs in frame with the coding region [Tucker et al . (1996) Proc. Natl. Acad. Sci. USA , 93, 12920-12925; Yoder et al . (1996) J. Biol. Chem . 271, 31092-31097]. Genomic DNA upstream of this ATG contains two more ATGs in frame and no obvious splice site. We have constructed, and expressed in baculovirus, MTase clones that begin at each of these four ATGs and examined their properties. Constructs beginning with any of the first three ATGs as their initiator methionines give a predominant DNA MTase band of approximately 185 kDa on SDS-PAGE corresponding to translational initiation at the third ATG. The fourth ATG construct gives a much smaller protein band of 173 kDa. The 185 kDa protein was purified by HPLC, characterized by mass spectrometry and has a measured molecular mass of 184 +/- 0.5 kDa. All of these MTases were functional in vitro and steady state kinetic analysis showed that the recombinant proteins exhibit similar kinetic properties irrespective of their length. The homogeneous recombinant enzyme from the fourth ATG construct shows a 2.5-fold preference for a hemi-methylated DNA substrate as compared to an unmethylated substrate, whereas the 185 kDa protein is equally active on both substrates. The kinetic properties of the recombinant enzyme are similar to those reported for the native MTase derived from murine erythroleukemia cells. The new clones are capable of yielding large quantities of intact MTases for further structural and functional studies.

Amino Acid Sequence↗
PubMed1997

Molecular analysis of a novel winged helix protein, WIN. Expression pattern, DNA binding property, and alternative splicing within the DNA binding domain.

We have cloned a novel winged helix factor, WIN, from the rat insulinoma cell line, INS-1. Northern blot analysis demonstrated that WIN is highly expressed in a variety of insulinoma cell lines and rat embryonic pancreas and liver. In adults, WIN expression was detected in thymus, testis, lung, and several intestinal regions. We determined the DNA sequences bound in vitro by baculovirus-expressed WIN protein in a polymerase chain reaction-based selection procedure. WIN was found to bind with high affinity to the selected sequence 5'-AGATTGAGTA-3', which is similar to the recently identified HNF-6 binding sequence 5'-DHWATTGAYTWWD-3' (where W = A or T, Y = T or C, H is not G, and D is not C). We have isolated human WIN cDNAs by library screening and 5'-rapid amplification of cDNA ends. Sequence analysis indicates that the carboxyl terminus of human WIN has been previously isolated as a putative phosphorylation substrate, MPM2-reactive phosphoprotein 2 (MPP2); WIN may be regulated by phosphorylation. Alignment of the rat and human WIN cDNAs and their comparison with mouse genomic sequence revealed that the WIN DNA binding domain is encoded by four exons, two of which (exons 4 and 6) are alternatively spliced to generate at least three classes of mRNA transcripts. These transcripts were shown by RNase protection assay to be differentially expressed in different tissues. Alternative splicing within the winged helix DNA binding domain might result in modulation of DNA binding specificity.

Alternative Splicing↗
PubMed1997

RNA aptamers that specifically bind to a K Ras-derived farnesylated peptide.

RNA aptamers were selected against an affinity column containing a farnesylated peptide modeled after the carboxyl terminus of K ras, the major oncogenic form of this small G protein family. After 10-rounds of selection, 25% of the RNA applied to the column could be specifically eluted. Sequence analysis of the binding RNA aptamers revealed two consensus sequences--GGGUGGG and GGGAGG. Quantitative fluorescence binding studies on two of the high-affinity aptamers, showed a binding affinities of 139 nM and 0.93 microM, respectively for the farnesylated peptide. Binding to the nonfarnesylated peptide was at least 10-fold weaker, showing that the aptamers can recognize the hydrophobic farnesyl moiety. High affinity aptamers could be useful in specifically interfering with oncogenic ras function in particular, and G proteins in general.

Base Sequence↗