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At least 865 records · Page 48Linked to original sources
PubMed1992

Evidence for inserted sequences in the head region of nonmuscle myosin specific to the nervous system. Cloning of the cDNA encoding the myosin heavy chain-B isoform of vertebrate nonmuscle myosin.

The complete amino acid sequence of a vertebrate nonmuscle myosin heavy chain-B isoform (MHC-B, 1976 amino acids, 229 kDa) has been deduced by using cDNA clones from chicken brain libraries. The chicken nonmuscle MHC-B shows overall similarity in primary structure to other MHCs in the areas contributing to the ATP-binding site and actin-binding site. Similar to other nonsarcomeric MHC IIs, there is a short uncoiled tail sequence at the carboxyl terminus of the molecule. It is in the uncoiled tail sequence that the greatest number of differences in amino acids sequence between MHC-A and B were found, which allowed generation of isoform-specific antibodies. These antibodies were used to determine the relative content of MHC-A and MHC-B in various tissues. During the cloning of the cDNA encoding chicken brain MHC-B, we found a 63-nucleotide insertion encoding 21 amino acids located in the head region of the MHC near to the actin-binding site and a 30 nucleotide insertion encoding 10 amino acids near to the ATP-binding site. Analysis using S-1 nuclease showed that both inserts are expressed in a tissue-dependent manner; mRNA containing the inserts is present in tissues of the nervous system, but is absent from other non-muscle cells, which contain the noninserted isoform of MHC-B. Similar inserts were found in corresponding positions in human cerebellar mRNA. Antibodies raised against a peptide synthesized based on the 21 amino acid insert found in chickens recognize a MHC isoform in the same tissues that are enriched for the mRNA. These insertions appear to be a mechanism for generating additional MHC-B isoforms specific to the nervous system.

Amino Acid Sequence↗
PubMed1992

Requirement for three membrane-spanning alpha-helices in the post-translational insertion of a thylakoid membrane protein.

The insertion of a protein into a lipid bilayer usually involves a short signal sequence and can occur either during or after translation. A light-harvesting chlorophyll a/b-binding protein (LHCP) is synthesized in the cytoplasm of plant cells as a precursor and is post-translationally imported into chloroplasts where it subsequently inserts into the thylakoid membrane. Only mature LHCP is required for insertion into the thylakoid. To define which sequences of the mature protein are necessary and sufficient for thylakoid integration, fusion and deletion proteins and proteins with internal rearrangements were synthesized and incubated with isolated thylakoids and stroma. No evidence is found for the existence of a short signal sequence within LHCP, and, with the exception of the amino terminus and a short lumenal loop, the entire mature protein with consecutively ordered alpha-helices is required for insertion into thylakoid membranes. The addition of positive charges into stromal but not lumenal segments permits the insertion of mutant LHCPs into isolated thylakoids. Replacement of the LHCP transit peptide with the transit peptide from plastocyanin has no effect on LHCP insertion and does not restore insertion of the lumenal charge addition mutants.

Base Sequence↗
PubMed2005

[Linear insertion of the atrioventricular valves without defect].

On a first anatomical series of 52 hearts of trisomic 21 fetuses, published in June 2002, we described a new minor cardiac anomaly, belonging to the atrioventricular septal defect, with a linear insertion of the atrioventricular valves without defect. We want to confirm these data, on a larger series of 213 new hearts of trisomic 21 fetuses by adding a complementary section to the standard examination; 100% of controls have shown a normal insertion with an offsetting of the atrioventricular valves. On 113 out of these 213 hearts of trisomic 21 fetuses, with a so called "normal" heart at the standard examination showing no defect, the complementary section has shown that only 37.2% of these hearts have a normal insertion, whereas 62.83% show a linear insertion, without offsetting and without any septal defect. This linear insertion has been observed in all the different types of atrioventricular septal defect as a good hallmark for trisomy 21; but, since then, they have always been described associated with a septal defect, atrial or ventricular. Our hypothesis is that the linear insertion of the atrioventricular valves without defect is the minor form of the atrioventricular septal defect spectrum, taking place between the prior described partial types of atrioventricular septal defect, in which there is always a defect (ostium primum type atrial septal defect or inflow type ventricular septal defect), and the real normal heart. A precise description of the level of the complementary section and of the anatomic peculiarities of the linear insertion of the atrioventricular valves without defect would help its screening in fetal ultrasonography.

Autopsy↗
PubMed2005

Marginal microleakage around class V cavities restored with glass ceramic inserts of different coefficients of thermal expansion.

OBJECTIVE: Evaluate microleakage around Class V resin restorations restored with glass ceramic inserts of different coefficients of thermal expansion. METHODOLOGY: Sixty non-carious extracted human premolars (patient age range 12-20 years) were randomly assigned to three groups. Standard Class V preparations were cut in the buccal surface using customized Cerana burs, size 3. Glass ceramic inserts from two manufacturers (Cerana and Beta-Quartz) were used to restore the cavities, and were luted with a hybrid, high-viscous composite (Tetric Ceram) and a bonding agent (Excite). A control group, without inserts, was bulk-filled with a hybrid, high-viscous composite (Tetric Ceram). In accordance with American Dental Association (ADA) guidelines, half the preparation was in enamel and half in dentine/cementum, and had a mesio-distal width of 3 mm, an occluso-gingival height of 3 mm, and a depth of 2 mm. All margins had butt joints. The teeth were thermocycled 4000 times between water baths held at 5 degrees C and 55 degrees C, and the specimens prepared and examined for microleakage using 2.0% Procion Red dye, buffered at pH 7 as a marker. RESULTS: Microleakage was significantly less around cavities restored with Cerana glass ceramic inserts than around cavities restored with Beta Quartz glass ceramic inserts or the control cavities at both the occlusal and gingival margins, p = 0.003 and p = 0.014, respectively. Comparisons of both occlusal and gingival margins within both test groups and the control group showed there was significantly less microleakage at the enamel-resin interface than at the dentine-resin interface (p < 0.05 in all cases). CONCLUSION: The results strongly suggest that restorations restored with Cerana glass ceramic inserts, which have a coefficient of therml expansion approximating that of enamel, result in a decrease in marginal microleakage compared to Beta Quartz glass ceramic inserts and Tetric Ceram resin-based composite material.

Acrylic Resins↗
PubMed2005

Laryngeal mask airway insertion with remifentanil.

INTRODUCTION: We conducted a study to find out the best conditions for LMA insertion with two different doses of remifentanil added to propofol and propofol administered alone. METHODS: Following hospital clinical research ethics committee approval, 60 ASA I-II patients were included in the randomized double-blind study. Following premedication, patients received i.v. 0.25 microg kg(-1) remifentanil (Group R1), 0.50 microg kg(-1) remifentanil (Group R2) or normal saline (Group P) in 60 sec. Then following 20 mg lidocaine, propofol 2 mg kg(-1) were administered in R1 and R2 groups and 2.5 mg kg(-1) in P group. Ease of insertion of LMA and airway quality at first attempt was assessed. Number of attempts of LMA insertion, apnea time, additional propofol requirement and hemodynamic changes were recorded. RESULTS: There were no significant differences in demographic data among the patients. Apnea time (mean +/- SEM) was significantly shorter in P group (34.09 +/- 5.5 sec) compared to R1 (82.5 +/- 12.7 sec) and R2 (87.2 +/- 6.6 sec) groups (p = 0.01 and p = 0.001). Ease of LMA insertion was assessed as grade 1 in 100% of patients in R2 group while 65% in R1 and 30% in P groups. Undesirable responses following LMA insertion were observed in 54% of patients in P group. CONCLUSION: Propofol given 2.5 mg kg(-1) alone is not a good agent for LMA insertion. Remifentanil used in both doses combined with propofol provides good and excellent conditions for insertion of LMA with minimal hemodynamic disturbances.

Adjuvants, Anesthesia↗
PubMedDate not supplied

Peripherally inserted central catheters. Guidewire versus nonguidewire use: a comparative study.

To date, no research articles have been published that explore the practice of using guidewires for placement of peripherally inserted central catheters. The literature contains speculations regarding the pros and cons of guidewire use. However, no studies to date have compared patient outcomes when peripherally inserted central catheter lines are inserted with and without guidewires. To examine the use of guidewires for peripherally inserted central lines, a comparative study was conducted at two acute care facilities, one using guidewires for insertion and one inserting peripherally inserted central catheter lines without guidewires. 109 catheters were studied between January 1, 1990 and January 1, 1991. The primary focus of this study was to examine whether guidewire use places patients at higher risk for catheter-related complications, particularly phlebitis. No significant differences in phlebitis rates between the two study sites were found. Other catheter-related and noncatheter-related complications were similar between the two facilities. The results of this study do not support the belief that guidewire use increases complication rates.

Adolescent↗
PubMed2005

[Anesthetic management of tracheobronchial stent insertion in patients who underwent laser resection, balloon dilatation and tracheostomy in advance].

BACKGROUND: We report successful management of tracheobronchial stent insertion under general anesthesia. METHODS: In thirty-two cases, tracheobronchial stent insertion was performed under general anesthesia. The technique for airway management was chosen depending on the type of stent or the constriction level of the airway portion. We employed tracheostomy in order to avoid repeated intubations during the insertion of Dumon or Dynamic stent. In case of severe airway stenosis, laser resection or balloon dilatation was performed before stent insertion. RESULTS: We had 32 successful cases in 36 trials. Four trials failed due to insufficient expansion in one, mismatches of stent angle in one and pneumomediastinum in one. There was no exacerbation of respiratory condition in failed cases. There was no case who needed percutaneous cardiopulmonary support system. CONCLUSIONS: We managed tracheobronchial stent insertion under general anesthesia. Both the airway expansion by laser resection or balloon dilatation before stent insertion and also the insertion of Dumon or Dynamic stent through a tracheostomy were helpful strategies. These techniques facilitated more definitive airway maintenance and stable anesthetic management.

Airway Obstruction↗
PubMed2005

Subcutaneous microdialysis for children - safe biochemical tissue monitoring based on a minimal traumatizing no touch insertion technique.

BACKGROUND: Microdialysis (MD) enables analysis of extracellular metabolites without performing blood tests. Changes in the concentration of various metabolites can be monitored frequently on almost every type of human tissue. Microdialysis of subcutaneous tissue (sc MD) is of particular significance in the case of pediatric patients because diurnal profiles can be generated without repeated blood sampling. There are only a few scientific articles that describe the application of sc MD on neonates, infants, or children. So far, side effects have not been investigated comprehensively. This prospective study scrutinizes side effects of sc MD in pediatric patients, focusing on a Minimal Traumatizing Insertion Technique of the MD catheter. PATIENTS AND METHODS: 42 pediatric patients within four age categories participated in the study which involved bedside monitoring using sc MD, including 5 extremely low birth weight (ELBW) infants with a body weight <1000g. A total of 48 sc MD catheters were inserted. Selection criteria were risk of hypoglycaemia (n = 29), elevated lactate levels (n = 16), or aminoacidopathies (n = 3). Duration of sc MD ranged from 1 to 16 days. We used a Minimal Traumatizing Insertion Technique to safely insert the MD catheter into the subcutaneous tissue, characterized by blunt dissection of the tissue and by the use of a plastic cannula guidance to avoid desterilisation of the catheter. Complications and side effects related to sc MD were documented in standardized forms. RESULTS: The MD probe was easily placed even in the scanty adipose tissue of ELBW infants. During insertion of sc MD catheters accidental venous puncture occurred to 8%, and minor bleeding to 27%. Even with local anaesthesia insertion was painful for 40%. During the course of sc MD complications were rare: disturbance of perfusion flow 4%, catheter dislocation 4%, local bleeding 4%. No signs of systemic or local infection were observed, there were no cases of local incompatibility. All catheters were withdrawn completely without leaving a scar. Repeated measurements allowed the generation of diurnal metabolic profiles. In some cases (respiratory chain complex I deficiency, PDH-deficiency) significant therapeutical effects on the patients' metabolism were demonstrated. CONCLUSIONS: The present study proves long-term sc MD to be suitable and safe for biochemical tissue monitoring. Using our insertion technique, it can be applied to children of all ages without causing discomfort or severe side effects. As it permits frequent sampling it allows evaluating and optimizing therapy and means a substantial progress for pediatric observation.

Adolescent↗
PubMed2006

Detection of inadvertent airway intubation during gastric tube insertion: Capnography versus a colorimetric carbon dioxide detector.

BACKGROUND: In the medical intensive care unit at the University of Virginia Health System, capnography is used to detect end-tidal carbon dioxide to protect patients from inadvertent airway cannulation during placement of gastric tubes. OBJECTIVES: To compare the method in which capnography is used with a method in which a colorimetric carbon dioxide detector is used and to determine what variables affect accurate placement of gastric tubes. METHODS: A prospective convenience sample of 195 gastric tube insertions was studied in 130 adult patients in a medical intensive care unit. Standard insertions of gastric tubes (done with capnography) were simultaneously monitored by using a disposable colorimetric device, with a color change indicating the presence of carbon dioxide. RESULTS: Insertion variables included tube type (60% Salem sump tubes, 40% soft-bore feeding tubes), route of insertion (71% oral, 29% nasal), mechanical ventilation (81%), and decreased mental status (72%). Carbon dioxide was successfully detected with the colorimetric indicator (within seconds) in all insertions in which carbon dioxide was detected by capnography. When carbon dioxide was detected (27% of insertions), the tubes were withdrawn and reinserted. Carbon dioxide detection during tube placement was significantly associated with nasal insertions (P = .03) and spontaneously breathing/nonintubated status (P = .01) but not with mental status or tube type. CONCLUSIONS: A colorimetric device is as accurate as capnography for detecting carbon dioxide during placement of gastric tubes.

Adult↗
PubMed2005

[Improvement of package insert CYP information for prescription drugs marketed in Japan].

In clinical practice, one drug is frequently used in combination with one or more other drugs, rather than as a sole regimen, and therefore healthcare providers need to carefully consider drug interactions. As mechanisms of drug interactions, metabolic enzymes of drugs are seen as one of the most likely interactive sites, where a majority of drugs are metabolized by cytochrome P450 (CYP). For this reason, providing appropriate information on CYP in package inserts is of grave importance. In fact, the package insert is the primary tool for supplying information on drugs to healthcare providers. The present study was designed to determine how many package inserts of prescription drugs marketed in Japan were providing CYP information. We searched the April 2003 version of "Drugs in Japan DB," which listed 2,022 prescription drugs, and found that only 239 package inserts (11.8%) mentioned CYP information and that only 194 (9.6%) specified CYP isozymes. To assess the improvement of package inserts, we searched "Drugs in Japan DB" from the January 2000 version to the April 2003 version. We found that CYP information had increased year by year (eg, 7.8-11.8% annually). For newly approved drugs, an analysis of the relationship between approval year and CYP information in package inserts (April 2003 version) revealed that recently approved drugs had more CYP information (eg, 45.5-51.3% of drugs in 1999-2002, compared to 6.8-26.1% in 1991-1996). A search for regulatory review documents for new drugs approved from 1999 to 2002 suggested that this recent improvement could be related to the increased number of studies identifying CYP isozymes involved in the metabolism or interaction with other drugs. Another reason for the recent improvement may be the fact that the guideline for package inserts for prescription drugs was revised in 1997, and the guidelines for drug interaction and pharmacokinetic studies were published between 1997 and 1999.

Cytochrome P-450 Enzyme System↗
PubMed1992

Insertional mutagenesis of Bordetella pertussis adenylate cyclase.

We developed an improved method of linker insertion mutagenesis for introducing 2 or 16 codons into the Bordetella pertussis cyaA gene which encodes a calmodulin-dependent adenylate cyclase. A recombinant kanamycin resistance cassette, containing oligonucleotide linkers, was cloned in plasmids which carried a truncated cyaA gene, fused at its 3' end to the 5' end of the Escherichia coli lacZ gene, specifying the alpha-peptide. This construction permitted a double selection for in-frame insertions by using screening for kanamycin resistance and for lactose-positive phenotype, resulting from alpha-complementation. We showed that most of the two-amino acid insertions within the N-terminal moiety of the catalytic domain of adenylate cyclase abolished enzymatic activity and/or altered the stability of the protein. All two-amino acid insertions within the C-terminal part of adenylate cyclase resulted in fully stable and active enzymes. These results confirm the modular structure of the catalytic domain of adenylate cyclase, previously proposed on the basis of proteolytic studies. Two-amino acid insertions between residues 247-248 and 335-336 were shown to affect the calmodulin responsiveness of adenylate cyclase, suggesting that the corresponding region in the enzyme is involved in the binding of calmodulin or in the process of calmodulin activation. In addition, we have identified within the primary structure of adenylate cyclase several permissive sites which tolerate 16-amino acid insertions without interfering with the catalytic activity or calmodulin binding. By inserting foreign antigenic determinants into these permissive sites the resulting recombinant adenylate cyclase toxin could be used to deliver specific epitopes into antigen-presenting cells.

Adenylyl Cyclases↗
PubMed1990

Anterior tibial tendon insertion: an anatomical study.

Anatomical variations of the anterior tibial tendon insertion were studied by dissection in 44 normal feet of 22 embalmed adult cadavers. Three types of insertion were found. The most common insertion (56.8%) was a division of the tendon into two slips, equal in width, the one slip being inserted into the first cuneiform and the other slip into the base of the first metatarsal. The next most common (27.3%) was a division of the tendon into a large slip, inserted into the first cuneiform, and a small slip, inserted into the base of the first metatarsal. The third type, and least common tendon insertion (15.9%), was by a single slip into the first cuneiform only. Knowledge of these anatomical variations will assist surgeon in performing anterior tibial tendon transposition for recurrent congenital clubfoot.

Adult↗
PubMed1989

Ubiquitin is involved in the in vitro insertion of monoamine oxidase B into mitochondrial outer membranes.

Monoamine oxidase B that has been synthesized by a reticulocyte lysate charged with bovine liver RNA will insert in a proteinase K-resistant form into isolated outer membranes from rat liver mitochondria. It appears that ubiquitin, a 76-amino acid polypeptide which is enzymatically conjugated to proteins, may be involved in the insertion process. Depletion of endogenous ubiquitin from the reticulocyte lysate with purified antibodies against this polypeptide inhibits the insertion of monoamine oxidase B, and this inhibition is relieved if ubiquitin is restored. On the other hand, a mutant form of ubiquitin which is unable to conjugate with proteins will not support insertion. Conjugation with ubiquitin is an ATP-dependent process. Not only does enzymatic depletion of ATP from the lysate prevent the insertion of monoamine oxidase, but ubiquitin will not restore insertion unless ATP is also present. These data indicate that the formation of a ubiquitin conjugate is involved in the insertion of newly synthesized monoamine oxidase B into the outer membranes.

Adenosine Triphosphate↗
PubMed1986

Pseudomonas exotoxin A. Membrane binding, insertion, and traversal.

Using vesicle targets composed of phosphatidylcholine and cholesterol (1:1 molar ratio), we found that Pseudomonas aeruginosa exotoxin A (PTx) binding and insertion are not only dependent on pH (Zalman, L.S., and Wisnieski, B.J. (1985) Infect. Immun. 50, 630-635) but also on ionic strength, reaching a maximum in pH 4 buffer that contains 150-200 mM NaCl. Insertion was monitored by photolabeling with an intramembranous probe. Higher levels of binding and insertion were attained with vesicles that contained 2.5 mol% dicetylphosphate than with neutral vesicles. Positively charged vesicles (2.7 mol% stearylamine) were the least effective targets. At pH 7.4, all binding levels were depressed. While PTx binding increased with increasing temperature, the relative proportion of the vesicle-associated toxin that was photolabeled decreased. The most likely explanation for the decrease is that the bilayer translocation rates increased with increasing temperature, and hence fewer PTx molecules were accessible at the time of photolabeling. At 37 degrees C, binding and insertion both plateaued within 10 min of lowering the pH to 4. After 10 min, the amount of bound toxin decreased slightly with time but there was a dramatic decrease in photolabeling, indicating that inserted PTx had begun to cross the bilayer. This was verified by the finding that when PTx was incubated with vesicles that contained trypsin, cleavage occurred only in those samples in which the pH was shifted down to pH 4. Entry is triggered by an acid-induced conformational change that promotes productive binding and insertion. After insertion, the kinetics of membrane traversal appear to be regulated by the physical properties of the bilayer.

ADP Ribose Transferases↗
PubMed1973

Smallpox vaccination immunity in relation to number of insertions.

The influence of the number of insertions of vaccine on smallpox vaccination immunity has been the subject of considerable controversy. In this study the problem was investigated in children of comparable age, sex, and smallpox vaccination history. The incidence of post-vaccinal fever and the antibody response of subjects given single and double insertions were compared. While single insertions caused fewer febrile reactions than double insertions, the difference was not significant. Successful vaccination invariably elicited a marked neutralizing antibody response. However, subjects who received two insertions developed significantly higher antibody titres than subjects with a single insertion. In the revaccinated group the difference in titre was still demonstrable 16 months after vaccination. It is concluded that the number of insertions may play a role in the duration of vaccination immunity.

Antibody Formation↗
PubMedDate not supplied

[Physical mapping of Streptomyces coelicolor A3(2) actinophages. VII. Formation of deletions in the region of phi C43 insertion sequence].

The correlation between the plaque morphology and the presence of the insertion sequence at the phage genomes have been found for different variants of phi C43, obtained by spontaneous induction of strain S. lividans 803. Phages carrying complete insertion have Tum phenotype and they are represented in 4% of induced lysate. Phages carrying the part of insertion have Tu phenotype, their portion in induced lysate is about 26%. Phages without insertion have Stu phenotype and they are the majority of the lysate (70%). All variants phi C43, except wild-type phage, have lost the fragment of phage genome. Phage phi C43ins1, carrying the complete insertion give rise spontaneously at the frequency 10(-2) to deletion derivatives. Heteroduplex experiments show that in the deletion derivatives phi C43ins1 also in the Stu and Tu variants phi C43 one of the termini of the deletions is located within the insertion or at its end. Considerable portion of deletion variants in induced lysate phi C43 also the formation of deletion derivatives phi C43ins1 with high frequency strongly suggest that insertion sequence generates deletions similar to IS of Tn elements.

Bacteriophages↗
PubMed1984

Evidence for direct insertion of fragments A and B of diphtheria toxin into model membranes.

The entry of diphtheria toxin into model membranes was studied using a membrane-restricted photoprobe to monitor insertion. The results provided direct evidence that the A and B domains of diphtheria toxin can both insert into such membranes. Optimal binding was achieved with negatively charged liposomes at pH 3.6. Under these conditions, the A and B domains of nicked as well as unnicked toxin inserted. At 0 degrees C, only fragment B inserted although toxin was still optimally bound. At neutral pH, there was little binding of toxin, and fragment B inserted preferentially. Brief exposure of the toxin to pH 3.6 followed by adjustment of the pH to 7 and subsequent incubation of the toxin with vesicles at neutral pH greatly facilitated toxin binding as well as insertion of both A and B domains, indicating also that a pH gradient was not required for these processes. Data obtained from the tryptic fragmentation patterns and circular dichroism spectra indicated that exposure to acidic pH had induced a conformational change in the toxin which may have exposed hydrophobic regions. A similar conformational change may occur in vivo after acidification of cytoplasmic vesicles into which toxin is delivered by receptor-mediated endocytosis. This could facilitate insertion of toxin into the vesicle membranes and subsequent translocation of fragment A to the cytosol, where it causes inhibition of protein synthesis.

Circular Dichroism↗
PubMed1984

Insertion of Hickman catheters. A comparison of cutdown and percutaneous techniques.

The insertion of Hickman catheters is useful in providing long-term vascular access in patients with a variety of conditions. Recently, enthusiasm has developed for the percutaneous insertion of the catheter because of the speed and ease of insertion. The insertion of 82 Hickman catheters in adults was reviewed. Thirty (94%) of 32 patients had a catheter placed successfully using a cutdown technique with success in 75 per cent of patients with the initial cutdown. Catheter placement was successful in 48 (96%) of the 50 patients with the percutaneous technique. The average operating time was 77 min for the cutdown technique compared with 33 min with percutaneous insertion. The overall complication rate was 18 per cent using the cutdown technique and 16 per cent for the percutaneous technique. The percutaneous technique for inserting Hickman catheters results in a much shorter operating time with minimal morbidity. As with any subclavian puncture, however, there is the risk of significant complications. The cutdown technique should be considered in patients with coagulopathy and when difficulty performing a percutaneous insertion is anticipated.

Adolescent↗