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At least 649 records · Page 36Linked to original sources
PubMed1982

Respiratory resistance from 1 to 46 ATA measured with the interrupter technique.

Measurements of respiratory resistance by an interrupter technique were made in six subjects during a Navy saturation dive to 457 m. Repeated measurements were made at five depths with complete pulmonary function testing after the dive. Increase in resistance was about linear with gas density (rho). Three smokers exhibited a significantly steeper slope of the respiratory resistance versus rho relationship than three nonsmokers. The disparity in resistance among the divers became considerable only at great pressure. Likewise, the predictions of two contradictory fluid dynamic theories agreed fairly well with our data and with each other over the densities explored and disagreed greatly with our data only at higher pressures.

Adult↗
PubMed2002

The impact of single-dose diethylcarbamazine treatment of bancroftian filariasis in a low-endemicity setting in Egypt.

This study was designed to evaluate the effect of a single dose of diethylcarbamazine (DEC, 6 mg/kg) on Wuchereria bancrofti infections in a low-endemicity setting in Egypt (microfilaremia, or MF, 3.7%, median MF 34/mL). Subjects with MF or filarial antigenemia were treated and restudied 1 year later. Treatment with DEC dramatically reduced blood MF counts, with clearance in 69% of subjects. Treatment also reduced filarial antigen levels, but low clearance rates suggest that some adult worms survived treatment in most patients. Mass treatment was administered in one village; 27 months later, MF prevalence had decreased 84% (from 4.9% to 0.8%). These results show that single-dose DEC treatment can have a major effect on MF prevalence rates and levels in low-endemicity settings. Although the World Health Organization advocates repeated multidrug regimens for filariasis elimination, mass treatment with DEC alone may be sufficient to interrupt transmission in areas with low infection intensities and prevalence rates.

Adolescent↗
PubMed2002

[A patient with pulmonary endometriosis].

A 30-year-old woman consulted for recent repeated episodes of hemoptysis occurring at the onset of the menses a few months after interruption of estrogen-progesterone treatment. This patient's only surgical history involved uterine curetage. She was a smoker and had cumulated 10 pack-years. Physical examination and chest x-rays were normal. Bronchial endoscopy and cytological examination of the bronchial aspiration were normal. Thoracic CT demonstrated an alveolar image in the right lower lobe. A second CT performed later after resolution of the episode of hemoptysis was normal. Laparoscopy was performed and visualized an endometrial nodule in the pelvis which was removed. The patient's clinical signs disappeared after treatment with triptoreline. Bronchopulmonary endometriosis is an uncommon condition. The main manifestations are catamenial hemoptysis during the first days of the menses. Chest pain is exceptional. Diagnosis may result from an incidental discovery. A traumatic intervention on the uterus is often found in the patient's history. The most commonly proposed pathogenic mechanism involves hematogenic migration following a uterine procedure. Imaging does not disclose specific signs and bronchial endoscopy is often normal but may demonstrate a tracheal or bronchial plaque of endometriosis, or exceptionally endometrial tissue in the endoscopy biopsies. LH-RH agonists remain the current treatment.

Adult↗
PubMed1988

Effect of nasogastric feedings on arterial oxygen tension in patients with symptomatic chronic obstructive pulmonary disease.

Meal-induced hypoxemia may occur in asymptomatic patients with chronic obstructive pulmonary disease (COPD). The need to address the nutritional requirements in symptomatic COPD patients has recently been reported. Accordingly, we studied the effect of nasogastric feedings on arterial oxygen tension in patients receiving nasogastric feedings. Eleven patients studied had heterogeneous symptomatic COPD with various requirements for either bronchodilators, oxygen, or ventilator support. Samples for arterial blood gas (ABG) determinations were drawn (first ABG value) at the time of interrupting continuous feedings (75 ml/hr) or just before a small bolus feeding (75 ml). A repeat ABG sample (second ABG value) was drawn 30 minutes later. There was a small but statistically significant difference between the first and second arterial oxygen tension values. This difference, however, was not clinically significant. Our preliminary results suggest that symptomatic COPD patients experience hypoxemia with nasogastric feedings.

Aged↗
PubMed1985

Modulation of striatal enkephalinergic neurons by antipsychotic drugs.

In this paper we review the detailed mechanisms underlying the modulation of enkephalinergic neurons by dopaminergic neurons in rat striatum. Several lines of evidence, which showed that striatal levels of [Met5]enkephalin (ME) increase after the nigrostriatal dopaminergic pathway was interrupted by hemitransection or direct administration of 6-hydroxydopamine to the substantia nigra, or after repeated injections of either reserpine or haloperidol, suggest that dopamine (DA) plays an important role in regulating the metabolism of ME-containing neurons in the striatum. The increase in ME content after repeated injections of haloperidol was found in areas heavily innervated by DA neurons such as striatum or nucleus accumbens but not in hypothalamus, brain stem, and hippocampus. Further studies suggest that striatal cholinergic interneurons may partially mediate the action of haloperidol on enkephalinergic neurons. Several studies have been carried out to determine whether the elevation of striatal ME content after haloperidol treatment was caused by an increase in the synthesis or by a decrease in the utilization of ME. The rate of decline of striatal ME content in haloperidol-treated rats was steeper than that of controls after intraventricular injection of cycloheximide, which indicated that haloperidol accelerates the turnover of ME. This hypothesis was confirmed by our recent findings that the level of mRNA coding for preproenkephalin A, determined by cell-free translation and blot hybridization with cDNA clones, is increased after repeated injections of haloperidol.

Animals↗
PubMed1982

[The vascularization of the anterior portion of the medial rectus muscle after a Cupper's thread operation].

Development of vascularization of the anterior part of the medial rectus muscle after Cüppers' thread operation was studied by injected barium sulphate into the ophthalmic artery of 8 corpses. Properly distributed and normally tightened myoscleral sutures, as with surgical operations for strabismus, do not hinder circulation of the contrast medium, whereas markedly tightened sutures interrupt its circulation. These experimental results as well as clinical and pathological findings following 18 repeat surgical operations, clearly show that Cüppers' thread operation is not hazardous when a very strict operative technique is respected.

Cadaver↗
PubMed1994

[Propofol in emergency care--areas of application and initial experiences].

So far propofol has only been used in clinical settings for sedation and induction of anaesthesia. This study describes several indications in preclinical and emergency events. All users were anaesthetists, so that experience of administration and dosage was extremely helpful. Since the drug met the expected criteria it is now regularly used for the sedation of ventilated patients during transport. The most important indications for preclinical induction of anesthesia with propofol are patients with isolated head injury and patients with respiratory insufficiency due to status asthmaticus resistant to therapy. After repeated unsuccessful attempts at therapeutic intervention with benzodiazepines and other antiepileptics we were able to interrupt status epilepticus in 11 patients by means of propofol, thereby preventing the patient from being intubated as a consequence of iatrogenic respiratory failure. However, emergency doctors must always be aware of the severe cardiocirculatory side effects of the drug, and must, hence, ensure that hypovolaemia or cardiac failure is excluded or corrected prior to propofol administration.

Adult↗
PubMed2004

Rapid and accurate characterisation of short tandem repeats by MALDI-TOF analysis of endonuclease cleaved RNA transcripts.

We describe the application of matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry (MALDI-TOF MS) for the characterisation of short tandem repeat (STR) sequences by the analysis of endonuclease cleaved RNA transcripts. Several simple bovine STR loci as well as interrupted and compound microsatellites were chosen as model loci to evaluate the capabilities of MALDI-TOF MS for STR analysis. In short, the described approach consists of a PCR amplification of the investigated STR sequence, which then is transcribed into RNA and cleaved by G-specific RNase T1. Base-specific cleavage of the transcript results in high informative fragment patterns from both the repetitive core sequence and the flanking region. Since sequence specificity from endonuclease cleavage is combined with the accuracy of MALDI-TOF measurements, this technique allows for fast and reliable determination of simple repeat lengths as well as for further characterisation of STR allele sequences, which is of high interest especially in more complex STR loci.

Dinucleotide Repeats↗
PubMed1984

A linear DNA plasmid from Streptomyces rochei with an inverted terminal repetition of 614 base pairs.

The terminal structure of a linear plasmid pSLA2 , which was isolated from Streptomyces rochei , was analysed. The 5' ends of pSLA2 DNA were blocked by the association of a protein probably covalently bonded with the DNA. This block is removed by alkali treatment and blunt ends with 5'-phosphate and 3'-hydroxy termini were released. The two terminal fragments of pSLA2 were cloned and the nucleotide sequence was determined. An inverted terminal repetition of 614 bp was found along with the presence of further interrupted homologous sequences beyond this area up to 800 bp. These are the first inverted terminal repeat sequences found in microbial linear plasmids.

Base Composition↗
PubMed1992

A new example of physical linkage between Tn1 and Tn21: the antibiotic multiple-resistance region of plasmid pCFF04 encoding extended-spectrum beta-lactamase TEM-3.

The genetic environment of plasmid-borne blaTEM mutant genes, encoding nine distinct TEM-type extended-spectrum beta-lactamases, was studied in transconjugants from clinical isolates of enterobacteria. Colony hybridization with probes specific for tnpA and tnpR of Tn3, tnpA and tnpI of Tn21, aacA4, and IS15, and restriction endonuclease analysis of plasmid DNA indicated that the structural genes for the enzymes were always associated with intact or deleted variants of the Tn3 family. Four of the nine blaTEM variants, which account for 62% of 222 isolates in a molecular epidemiological study, were associated with replicons indistinguishable from the epidemic Inc7-M plasmid pCFF04 that carries the blaTEM-3 gene. This suggests that mutant genes were selected from the same prototype plasmid carrying penicillinase genes blaTEM-1 or -2. A 6.6 kb DNA fragment of pCFF04 containing blaTEM-3 was characterized by amplification mapping and sequencing. The results obtained indicated that blaTEM-3 was present on a copy of Tn1 interrupted at the start codon of the transposase by a DNA sequence reminiscent of the inverted repeats of class II transposons. This partial Tn1 copy was in turn, inserted into the transposase gene of a Tn21-like transposon containing an integron expressing an aacA4 gene. The presence of an integron can account for the various assortments of aminoglycoside resistance genes found associated with blaTEM-3.

Amino Acid Sequence↗
PubMed2001

Mechanical determinants of graft kinking.

Vascular grafts can be twisted inadvertently during implantation. If twisted excessively, they may kink and obstruct flow. In this study, in vitro experiments were performed to identify the mechanical factors that determine graft kinking. These included graft material, graft length, graft diameter, graft wall thickness, perfusion pressure, and flow rate. Six-millimeter-diameter saphenous veins were obtained from humans at autopsy. Six-millimeter standard-wall and 6-mm thin-wall polytetrafluoroethylene (PTFE) grafts also were obtained. Both fixed-length and stretchable PTFE grafts were examined. Grafts 15, 30, 50, and 70 cm in length were evaluated. Finally, PTFE grafts 4, 6, 8, 10, 12, and 14 mm in diameter were studied to determine the effect of diameter. The vessels were mounted horizontally in vitro and were perfused with saline at 50, 100, or 150 mmHg pressure at low (49 mL/min), medium (105 mL/min), and high (239 mL/min) flow rates. Each graft was twisted 90 degrees, then subjected to perfusion for 15 sec. Pressure and flow were interrupted, and an additional 90 degrees twist was imposed for another 15 sec. This sequence was repeated until a visible kink developed. We conclude from our results that, when constructing a bypass, particular care should be taken with vein, short grafts, thin-wall grafts, and large-diameter grafts, as these are especially susceptible to kinking.

Biomechanical Phenomena↗
PubMed1989

Subchronic (13-week) inhalation toxicity study of formaldehyde in male rats: 8-hour intermittent versus 8-hour continuous exposures.

Male Wistar rats were exposed for 13 weeks, 5 days a week to 0 (controls), 1 or 2 ppm formaldehyde continuously (8 h a day), or to 2 or 4 ppm formaldehyde interruptedly (eight 30-min exposure periods separated by 30-min non-exposure periods a day). Histopathological changes were only found in the nose of animals (interruptedly) exposed to 4 ppm formaldehyde and comprised an increased degree and incidence of disarrangement and squamous metaplasia accompanied by basal cell hyperplasia and occasionally by keratinization of the respiratory epithelium. Two ppm formaldehyde was the non-toxic effect level. Cell proliferation studies demonstrated a slightly higher cell turnover of the nasal respiratory epithelium exposed (interruptedly) to 4 ppm formaldehyde than in controls. It was concluded that under the conditions of repeated exposure to marginally cytotoxic concentrations during a period of 13 weeks the exposure concentration rather than the total 'dose' (= concentration x exposure time) determined the severity of the cytotoxic effects of formaldehyde on the nasal epithelium.

Administration, Inhalation↗
PubMed1995

Characterization of Aphidius ervi (Hymenoptera, Braconidae) ribosomal genes and identification of site-specific insertion elements belonging to the non-LTR retrotransposon family.

We performed a molecular analysis of the Aphidius ervi ribosomal gene structure. This insect belongs to a set of closely related Aphidiinae species of the genus Aphidius Nees, of relevant interest in biological control. We constructed A. ervi genomic libraries, cloned and characterized several rDNA repeating units and sequenced different regions of the rDNA cistrons. We have found that insertion sequences interrupt the A. ervi 28S rDNA genes: the sequences of the two 5' and 3' insertion-28S junctions show that the elements are present at the position where R1 elements have been found in various insect species. In addition, the insertion of the element produces a duplication of the 14 nt target region. The sequence analysis indicates that the A. ervi elements belong to the R1 retrotransposon family with a highly conserved reverse transcriptase domain.

Amino Acid Sequence↗
PubMed2000

Somatic polyploidization and cellular proliferation drive body size evolution in nematodes.

Most of the hypodermis of a rhabditid nematode such as Caenorhabditis elegans is a single syncytium. The size of this syncytium (as measured by body size) has evolved repeatedly in the rhabditid nematodes. Two cellular mechanisms are important in the evolution of body size: changes in the numbers of cells that fuse with the syncytium, and the extent of its acellular growth. Thus nematodes differ from mammals and other invertebrates in which body size evolution is caused by changes in cell number alone. The evolution of acellular syncytial growth in nematodes is also associated with changes in the ploidy of hypodermal nuclei. These nuclei are polyploid as a consequence of iterative rounds of endoreduplication, and this endocycle has evolved repeatedly. The association between acellular growth and endoreduplication is also seen in C. elegans mutations that interrupt transforming growth factor-beta signaling and that result in dwarfism and deficiencies in hypodermal ploidy. The transforming growth factor-beta pathway is a candidate for being involved in nematode body size evolution.

Animals↗
PubMed1999

CD8+ cell-derived anti-human immunodeficiency virus inhibitory factor.

CD8+ cells in human immunodeficiency virus (HIV)-infected individuals develop the ability to control HIV replication not only by destruction of the infected cells but also by controlling the virus in a noncytotoxic fashion that leaves the infected cell functionally intact. The CD8+ noncytotoxic response is mediated by a novel soluble factor known as CD8+ cell antiviral factor (CAF). CAF suppresses HIV replication in the infected cell at the level of viral transcription by interrupting the ability of Tat or host cellular factors to interact with the HIV long terminal repeats. Unlike some strain-specific anti-HIV cytokines, CAF is active against many different virus isolates, including HIV strains that are nonsyncytium- and syncytium-inducing. Of importance, the ability of CD8+ cells to produce CAF and suppress HIV replication plays a critical role in preventing disease progression following HIV infection.

CD8-Positive T-Lymphocytes↗
PubMed1995

Collapse and repair of replication forks in Escherichia coli.

Single-strand interruptions in a template DNA are likely to cause collapse of replication forks. We propose a model for the repair of collapsed replication forks in Escherichia coli by the RecBCD recombinational pathway. The model gives reasons for the preferential orientation of Chi sites in the E. coli chromosome and accounts for the hyper-rec phenotype of the strains with increased numbers of single-strand interruptions in their DNA. On the basis of the model we offer schemes for various repeat-mediated recombinational events and discuss a mechanism for quasi-conservative DNA replication explaining the recombinational repair-associated mutagenesis.

Chromosomes, Bacterial↗
PubMed1991

Self-injury concept formation: nursing diagnosis development.

Self-inflicted injury, an increasingly common phenomenon in psychiatric settings, often is seen in borderline clients who scratch or burn themselves repeatedly. Their dysfunctional behavioral patterns present special challenges to the psychiatric/mental health nurse who seeks to interrupt such destructive means of coping. Aside from the difficult task of assisting these individuals to deal with their feelings in a constructive way, the psychiatric nurse often struggles with difficult countertransference feelings. The authors review a historical perspective of self-injury behaviors, define the phenomenon through the procedure of concept analysis, propose the creation of a new nursing diagnosis, and outline interventions appropriate for these clients.

Humans↗
PubMed1979

Dynamic mechanisms determine functional residual capacity in mice, Mus musculus.

Awake mice (22.6--32.6 g) were anesthetized intravenously during head-out body plethysmography. One minute after pentobarbital sodium anesthesia, tidal volume had fallen from 0.28 +/- 0.04 to 0.14 +/- 0.02 ml and frequency from 181 +/- 20 to 142 +/- 8. Functional residual capacity (FRC) decreased by 0.10 +/- 0.02 ml. Expiratory flow-volume curves were linear, highly repeatable, and submaximal over substantial portions of expiration in awake and anesthetized mice; and expiration was interrupted at substantial flows that abruptly fell to and crossed zero as inspiration interrupted relaxed expiration. FRC is maintained at a higher level in awake mice due to a higher tidal volume and frequency coupled with expiratory braking (persistent inspiratory muscle activity or increased glottal resistance). In anesthetized mice, the absence of braking, coupled with reductions in tidal volume and frequency and a prolonged expiratory period, leads to FRCs that approach relaxation volume (Vr). An equation in derived to express the difference between FRC and Vr in terms of the portion of tidal volume expired without braking, the slope of the linear portion of the expiratory flow-volume curve expressed as V/V, the time fraction of one respiratory cycle spent in unbraked expiration, and respiratory frequency.

Anesthesia↗