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At least 91 records · Page 5Linked to original sources
PubMed1989

Somatic reversion of P transposable element insertion mutations in the singed locus of Drosophila melanogaster requiring specific P insertions and a trans- acting factor.

Destabilization in somatic cells of P-element insertions in the X-linked singed gene of Drosophila melanogaster has been studied. We have shown that some but not all unstable P-element insertions in singed can form mosaics. The cause of this variation is not clear from studies of the restriction maps of the mutations tested. The transposable element movements occur early in development and require, in addition to an appropriate P-element insertion in singed, a trans-acting maternal effect component. Movements appear to occur preferentially in attached-X stocks. However, the maternal effect component maps to the central region of chromosome 2.

Animals↗
PubMed2002

A nurse led peripherally inserted central catheter line insertion service is effective with radiological support.

AIM: Peripherally inserted central catheters (PICC) are increasingly used as a route of chemotherapy administration. Our aims were to assess a collaborative approach to PICC placement, with radiological support for a nurse led line insertion service in a minority of cases, and to determine whether PICC provided a safe and reliable method of chemotherapy administration. MATERIALS AND METHODS: Prospective data on 100 consecutive patients undergoing PICC placement for chemotherapy were collected. Lines were inserted by ward based nurses or under ultrasound guidance by radiologists. End points were successful completion of treatment or patient death. RESULTS: One hundred and forty-four lines were placed for 118 courses of chemotherapy. 107 (74%) were placed by nurses and 37 (26%) by radiologists. Ninety-five percent of patients completed therapy with either one or two lines. Seventy percent of lines were removed on achieving the primary end points. In two additional patients PICC could not be placed radiologically. Twelve patients were unable to complete treatment with PICC alone, nine of these required an alternative administration route. The catheter related sepsis rate was 4.9%. CONCLUSION: The majority of PICC can be successfully placed by trained nurses, reserving image guidance only for more difficult cases. PICC have an acceptable complication profile, and decrease the need for tunnelled central lines.

Catheterization, Central Venous↗
PubMed1972

Structure of inserted bacteriophage Mu-1 DNA and physical mapping of bacterial genes by Mu-1 DNA insertion.

It is shown, by electron microscope observation of the structures of heteroduplexes, that Mu-1 DNA inserted into the bacterial episomes Flac and F(8)[1] is collinear with, rather than a circulation permutation of, the DNA of the mature Mu-1 bacteriophage. Observation of the position of the inserted Mu defines a point within the gene that has been inactivated (the lacI gene for Flac and a transfer gene in F(8)[1] in these particular instances). These examples illustrate a new, general method for physical gene mapping. The episome with Mu DNA inserted into F(8)[1] [i.e., F(8)[1](Mu)], although derived from a single colony, is heterogeneous in that a self-renatured sample shows a nonhomology loop of length 3.0 kb. This nonhomology loop, which has previously been observed in mature Mu-1 DNA, is due to an inversion.

Chromosome Mapping↗
PubMed2002

Topography of helices 5-7 in membrane-inserted diphtheria toxin T domain: identification and insertion boundaries of two hydrophobic sequences that do not form a stable transmembrane hairpin.

The T domain of diphtheria toxin undergoes a low pH-induced conformational change that allows it to penetrate cell membranes. T domain hydrophobic helices 8 and 9 can adopt two conformations, one close to the membrane surface (P state) and a second in which they apparently form a transmembrane hairpin (TM state). We have now studied T domain helices 5-7, a second cluster of hydrophobic helices, using Cys-scanning mutagenesis. After fluorescently labeling a series of Cys residues, penetration into a non-polar environment, accessibility to externally added antibodies, and relative depth in the bilayer were monitored. It was found that helices 5-7 insert shallowly in the P state and deeply in the TM state. Thus, the conformational changes in helices 5-7 are both similar and somehow linked to those in helices 8 and 9. The boundaries of deeply inserting sequences were also identified. One deeply inserted segment was found to span residues 270 to 290, which overlaps helix 5, and a second spanned residues 300 to 320, which includes most of helix 6 and all of helix 7. This indicates that helices 6 and 7 form a continuous hydrophobic segment despite their separation by a Pro-containing kink. Additionally, it is found that in the TM state some residues in the hydrophilic loop between helices 5 and 6 become more highly exposed than they are in the P state. Their exposure to external solution in the TM state indicates that helices 5-7 do not form a stable transmembrane hairpin. However, helix 5 and/or helices 6 plus 7 could form transmembrane structures that are in equilibrium with non-transmembrane states, or be kinetically prevented from forming a transmembrane structure. How helices 5-7 might influence the mechanism by which the T domain aids translocation of the diphtheria toxin A chain across membranes is discussed.

Amino Acid Sequence↗
PubMedDate not supplied

Local anesthesia prior to the insertion of peripherally inserted central catheters.

Using a randomized, controlled study, the investigators evaluated and compared the effects of local anesthesia versus no anesthesia on pain associated with peripherally inserted central catheter (PICC) insertion. A sample of 42 subjects was selected and divided into three groups. Group 1 received EMLA cream. Group 2 received buffered lidocaine. Group 3 (the control group) did not receive a local anesthetic. The short form of the McGill Pain Questionnaire was used to measure pain quality and intensity. A numerical Visual Analogue Scale accompanied the questionnaire and measured overall pain intensity. Results showed that buffered lidocaine was statistically superior to EMLA cream or no anesthetic in relieving pain associated with PICC insertion.

Adult↗
PubMed1987

The release of insoluble antibiotics from collagen ocular inserts in vitro and their insertion into the conjunctival sac of cattle.

The release rate of procaine penicillin, erythromycin and erythromycin estolate from soluble and insoluble collagen films was investigated in vitro to develop an ocular insert for the treatment of infectious bovine keratoconjunctivitis. The release rate and duration of release varied according to the selection of antibiotic and vehicle. The combination of erythromycin estolate and soluble collagen produced the most sustained drug-delivery system. However, due to the inappropriate physical properties of collagen and poor retention of ocular inserts, it was considered that the development of an antibiotic-impregnated collagen ocular insert requires further investigation.

Animals↗
PubMed1989

Specificity of insertion of IS91, an insertion sequence present in alpha-haemolysin plasmids of Escherichia coli.

We have determined the DNA sequences of eight different insertions of IS91 in a specifically engineered recipient plasmid of known DNA sequence (pSU300). The sequences at the termini of IS91 are 5'-CGAGTAGG...CCTATCGAT. IS91 inserts specifically 5' to either one of the tetranucleotides 5'-GAAC or 5'-CAAG, and always in the same relative orientation with respect to the sequence of the target. Except in one special case, no duplications of the recipient DNA were produced at the site of insertion.

Bacterial Proteins↗
PubMed1995

Characterization and distribution of two insertion sequences, IS1191 and iso-IS981, in Streptococcus thermophilus: does intergeneric transfer of insertion sequences occur in lactic acid bacteria co-cultures?

A chromosomal repeated sequence from Streptococcus thermophilus was identified as a new insertion sequence (IS), IS1191. This is the first IS element characterized in this species. This 1313 bp element has 28 bp imperfect terminal inverted repeats and is flanked by short direct repeats of 8 bp. The single large open reading frame of IS1191 encodes a 391-amino-acid protein which displays homologies with transposases encodes by IS1201 from Lactobacillus helveticus (44.5% amino-acid sequence identity) and by the other ISs of the IS256 family. One of the copies of IS1191 is inserted into a truncated iso-IS981 element. The nucleotide sequences of two truncated iso-IS981s from S. thermophilus and the sequence of IS981 element from Lactococcus lactis share more than 99% identity. The distribution of these insertion sequences in L. lactis and S. thermophilus strains suggests that intergeneric transfers occur during cocultures used in the manufacture of cheese.

Bacteria↗
PubMedDate not supplied

In vitro pullout strength of screws inserted in adult equine third metacarpal bone after overdrilling a 4.5-mm threaded insertion hole.

OBJECTIVE: To determine and compare the in vitro pullout strength of 5.5-mm cortical versus 6.5-mm cancellous bone screws inserted in the diaphysis and metaphysis of adult equine third metacarpal (MCIII) bones, in threaded 4.5-mm cortical bone screw insertion holes that were then overdrilled with a 4.5-mm drill bit to provide information relevant to the selection of a replacement screw if a 4.5-mm cortical screw is stripped. STUDY DESIGN: In vitro pullout tests of 5.5-mm cortical and 6.5-mm cancellous screws in equine MCIII bones. SAMPLE POPULATION: Two independent cadaver studies each consisting of 14 adult equine MCIII bones. METHODS: Two 4.5-mm cortical screws were placed either in the middiaphysis (study 1) or distal metaphysis (study 2) of MCIII bones. The holes were then overdrilled with a 4.5-mm drill bit and had either a 5.5-mm cortical or a 6.5-mm cancellous screw inserted; screw pullout tests were performed at a rate of 0.04 mm/second until screw or bone failure occurred. RESULTS: In diaphyseal bone, the screws failed in all tests. Tensile breaking strength for 5.5-mm cortical screws (997.5 +/- 49.3 kg) and 6.5-mm cancellous screws (931.6 +/- 19.5 kg) was not significantly different. In metaphyseal bone, the bone failed in all tests. The holding power for 6.5-mm cancellous screws (39.1 +/- 4.9 kg/mm) was significantly greater than 5.5-mm cortical screws (23.5 +/- 3.5 kg/mm) in the metaphysis. There was no difference in the tensile breaking strength of screws in the diaphysis between proximal and distal screw holes; however, the holding power was significantly greater in the distal, compared with the proximal, metaphyseal holes. CONCLUSIONS: Although tensile breaking strength was not different between 5.5-mm cortical and 6.5-mm cancellous screws in middiaphyseal cortical bone, holding power of 6.5-mm cancellous screws was greater than 5.5-mm cortical screws in metaphyseal bone of adult horses. CLINICAL RELEVANCE: If a 4.5-mm cortical bone screw strips in MCIII diaphyseal bone of adult horses, either a 5.5-mm cortical or 6.5-mm cancellous screw, however, would have equivalent pullout strengths. A 6.5-mm cancellous screw, however, would provide greater holding power than a 5.5-mm cortical screw in metaphyseal bone.

Animals↗
PubMed1999

IS1630 of Mycoplasma fermentans, a novel IS30-type insertion element that targets and duplicates inverted repeats of variable length and sequence during insertion.

A new insertion sequence (IS) of Mycoplasma fermentans is described. This element, designated IS1630, is 1,377 bp long and has 27-bp inverted repeats at the termini. A single open reading frame (ORF), predicted to encode a basic protein of either 366 or 387 amino acids (depending on the start codon utilized), occupies most of this compact element. The predicted translation product of this ORF has homology to transposases of the IS30 family of IS elements and is most closely related (27% identical amino acid residues) to the product of the prototype of the group, IS30. Multiple copies of IS1630 are present in the genomes of at least two M. fermentans strains. Characterization and comparison of nine copies of the element revealed that IS1630 exhibits unusual target site specificity and, upon insertion, duplicates target sequences in a manner unlike that of any other IS element. IS1630 was shown to have the striking ability to target and duplicate inverted repeats of variable length and sequence during transposition. IS30-type elements typically generate 2- or 3-bp target site duplications, whereas those created by IS1630 vary between 19 and 26 bp. With the exception of two recently reported IS4-type elements which have the ability to generate variable large duplications (B. B. Plikaytis, J. T. Crawford, and T. M. Shinnick, J. Bacteriol. 180:1037-1043, 1998; E. M. Vilei, J. Nicolet, and J. Frey, J. Bacteriol. 181:1319-1323, 1999), such large direct repeats had not been observed for other IS elements. Interestingly, the IS1630-generated duplications are all symmetrical inverted repeat sequences that are apparently derived from rho-independent transcription terminators of neighboring genes. Although the consensus target site for IS30 is almost palindromic, individual target sites possess considerably less inverted symmetry. In contrast, IS1630 appears to exhibit an increased stringency for inverted repeat recognition, since the majority of target sites had no mismatches in the inverted repeat sequences. In the course of this study, an additional copy of the previously identified insertion sequence ISMi1 was cloned. Analysis of the sequence of this element revealed that the transposase encoded by this element is more than 200 amino acid residues longer and is more closely related to the products of other IS3 family members than had previously been recognized. A potential site for programmed translational frameshifting in ISMi1 was also identified.

Amino Acid Sequence↗
PubMed1982

Prescription drugs; revocation of final guideline patient package inserts and withdrawal of draft guideline patient package inserts--Food and Drug Administration. Notice.

The Food and Drug Administration (FDA) is revoking the final guideline patient package inserts for 5 classes of drugs and is withdrawing the draft guideline patient package inserts for 5 other classes of drugs. Elsewhere in this issue of the Federal Register, the agency is revoking the regulations that established general requirements for the preparation and distribution of patient package inserts for prescription drug products. Those regulations had established a pilot program that would have been applied to 10 classes of drugs for 3 years. This notice revokes the draft and final guidelines which described how manufactures might comply with the regulations with respect to affected classes of drug.

Drug Labeling↗
PubMedDate not supplied

Clinical factors associated with the development of phlebitis after insertion of a peripherally inserted central catheter.

A descriptive comparison study was conducted to determine if there were any coagulation, immune, nutritional, or insertion-related differences between 64 adult hospitalized clients who experienced phlebitis after insertion of a peripherally inserted central catheter (PICC) compared with a matched group of 64 adult hospitalized clients who did not develop phlebitis. Factors that significantly decreased the development of phlebitis in this study included smaller catheter gauge, placement in the basilic vein, tip location in the superior vena cava, no manipulation or movement at the exit site, and higher platelet levels.

Adult↗
PubMed1991

[Function of the InsA gene in the IS1 element of the Tn9' transposon: influence of oligonucleotide inserts in the InsA gene on formation of simple insertions and plasmid cointegrates].

To elucidate the role of the insA reading frame in transposition of the IS1 element of the Tn9' transposon, the derivatives of plasmids pUC19::Tn9' and pUC19::IS1 have been obtained using oligonucleotide inserts of the length equal or exceeding 9 bp and equal to 10 bp. The ability of mutant variants of the Tn9' transposon and the IS1 element to form simple insertions and plasmid cointegrates was studied. To this end, experiments were performed on mobilization of the derivatives of pUC19 containing mutant variants of the IS1 element and Tn9' as well as of the plasmids pUC19::Tn9' by the conjugative plasmid pRP3.1. According to the data obtained, mutations (inserts) in the insA gene have no influence on the frequency of transposition of the IS1 element and Tn9' from the plasmid pUC19 to pRP3.1. At the same time, the frequency of transposition events of mutant variants of Tn9' from the plasmid pRP3.1 to pBR322 is more than 10 times lower in comparison with the wild type transposon. The data obtained are in accordance with the assumption that the insA gene is not essential for transposition. A hypothesis is put forward explaining the role of the insA gene product in the process of bringing together short inverted repeats of the IS1, which are the sites for the transposase to be recognized at first stages of transposition.

DNA Transposable Elements↗
PubMed1991

Insertion of diphtheria toxin B-fragment into the plasma membrane at low pH. Characterization and topology of inserted regions.

When the enzymatically active A-fragment of diphtheria toxin is translocated to the cytosol, the B-fragment inserts into the membrane in such a way that a 25-kDa polypeptide becomes shielded from proteases added to the external medium. We have attempted to determine the boundaries of this polypeptide within the toxin B-fragment as well as the topology of the B-fragment in the membrane. Chemical cleavage of the 25-kDa polypeptide with hydroxylamine and o-iodosobenzoic acid yielded fragments of sizes indicating that the 25-kDa polypeptide starts at residue approximately 300 and extends to the COOH-terminal end. Experiments where the toxin was labeled with [35S]cysteine at distinct positions of the B-fragment supported this conclusion. Treatment of cells with inserted B-fragment with L-1-tosyl-amido-2-phenylethyl chloromethyl ketone-treated trypsin and with V8 protease from Staphylococcus aureus yielded protected 27- and 30-kDa fragments in addition to 25 kDa, indicating that the region 240-264 is also at the outside. The topology of the inserted B-fragment is discussed.

Amino Acid Sequence↗
PubMed1987

'Bowing' forces with IUD inserters in vitro: relevance to difficult IUD insertions.

The inserter tubes of the more modern copper bearing IUDs are flexible enough to give ('bow') when there is obstruction to the device. The MLCu 250, Copper 7 and Nova T inserters will bow considerably when forces of 1-3 N are exerted and the device obstructed up to 0.75 cm from its proximal end. This suggests that these devices are unlikely to cause cervical damage where their passage into the uterine cavity is impeded by cervical factors, provided the insertion attempt is discontinued when bowing of more than 2 cm off-centre is reached. However this does not apply to obstructions past the internal cervical os. In research circumstances great care should be used as it rapidly becomes possible to exert enough force to produce damage to the uterine muscle.

Equipment Failure↗
PubMed1984

[Velamentous insertion--epidemiology and clinical aspects of the pathological insertion of the umbilical cord].

Among 9460 birth an incidence of 1.6% of velamentous insertion of the umbilical cord is recorded and the clinical relevance of this anomaly is examined. Apart from statistical confirmation of well-known connections between membranous insertion of the umbilical cord on the one hand, and malformations, multiple pregnancies and bleeding sub partu on the other hand, the present investigation is mainly concerned with premature births and/or placental insufficiency in the case of velamentous insertion of the umbilical cord, which is associated with "late premature births" in the 35th, 36th and 37th week of pregnancy as characteristic finding.

Adult↗
PubMed1994

[The study of insertion sequence on IS2. I. Polarity and inserted direction of IS2].

By using flj B, flj A selecting system, we investigated the effects of the insertion of IS2 into certain genes and found that IS2 could be inserted into the gene from either the left side or the right side resulting in the loss of its activity and inhibition of the next gene's expression within the same transcription. The polarities were different when IS2 was inserted from the left side or the right side. The results from the artificial testing system were the same as those obtained from the natural state.

Bacterial Proteins↗
PubMed1993

Activation of both Wnt-1 and Fgf-3 by insertion of mouse mammary tumor virus downstream in the reverse orientation: a reappraisal of the enhancer insertion model.

In retrovirus-induced tumors, proviral DNA is commonly found next to or within a cellular proto-oncogene such that transcription of the gene is influenced by the viral promoter or enhancer. Extensive surveys of naturally occurring tumors reveal that proviruses integrated on the 3' side of the gene are usually in the same transcriptional orientation, suggesting a model in which the bidirectional viral enhancer acts primarily on the closest promoters. Here we describe a virally induced mammary tumor that appears to contradict these ideas since the Wnt-1/int-1 and Fgf-3/int-2 proto-oncogenes have both been activated by mouse mammary tumor virus (MMTV) DNA integrated 3' of the gene in the opposite transcriptional orientation. However, by cloning the relevant DNAs, we show that these are not simple proviral insertions. In the Wnt-1 locus, there is an additional LTR immediately adjacent to the 3' end of the MMTV provirus, while in Fgf-3, the provirus has sustained a deletion that removes the 5' LTR, gag, and most of pol. These structural alterations can be reconciled with the enhancer insertion model by postulating that the viral enhancer can only function if it is not transcribed.

Animals↗