Search PubMed⌕ Search

Biomedical subjects

K Walsh

Publications and source records attributed to K Walsh.

At least 235 records · Page 13Linked to original sources
PubMed1992

Spectrum and frequency of pediatric illness presenting to a general community hospital emergency department.

Knowledge of the range of pediatric illness presenting to a general emergency department (ED) is needed to optimize the quality of care delivered there. It was hypothesized that the pediatric population treated at a general ED exhibited a broad range of medical complaints, while differing significantly from children seen in a pediatric ED. General ED records from 1 week each season were reviewed, and patient age, chief complaint, diagnosis, time of arrival, season, and disposition were recorded. Data on 874 patients were analyzed and compared with pediatric ED data. General ED patient age affected chief complaint, diagnosis, and admission rate (9.5% less than or equal to 1 year admitted vs 2.6% greater than 1 year, P less than .001). General ED patients were older (7.9 vs 6.0 years, P less than .001) and admitted less frequently (3.8% vs 11%, P less than .001). Admission rates varied by arrival time only at the general ED, where minor trauma was more common (41% vs 22%, P less than .001). It is concluded that a wide range of pediatric illness is treated in a general ED, supporting the decision to have pediatric emergency physicians on staff, and that significant differences exist in the spectrum and frequency of pediatric illness seen in a general ED and pediatric ED.

Adolescent↗
PubMed1991

Rabbit muscle creatine kinase: genomic cloning, sequencing, and analysis of upstream sequences important for expression in myocytes.

Muscle creatine kinase (MCK) is a major enzyme of cellular energy metabolism that is expressed upon differentiation of myoblasts into myotubes. Previously we cloned and sequenced the entire rabbit enzyme cDNA which was used as a probe in these studies to obtain a genomic clone from a rabbit library. The transcription start site was identified by primer extension analysis and over 800 bp of 5' flanking DNA was sequenced. Comparison of this sequence with the published sequences from the upstream regions of the mouse MCK gene and the human MCK gene showed two conserved regions and a large intervening block of non-conserved sequence. The conserved regions are separated by about 800 bp in the mouse and by about 400 bp in the human, but are much closer (200 bp) in the rabbit. The upstream conserved region of the mouse gene encompasses a region possessing the properties of an enhancer and containing two MyoD binding sites; the downstream element is adjacent to the start of transcription. A set of of overlapping deletions of the 5' upstream DNA was fused to the CAT gene and transfected into mouse C2 myocytes, chick primary myocytes, and chick primary liver cells. Constructs which contained both conserved 5' regions were strongly expressed in C2 and chick myocytes, but were not expressed (above background) in primary liver cells. Surprisingly, while the upstream enhancer element was required for strong expression in C2 myocytes, it was less important for expression in chick myocytes. This suggests that there are important muscle-specific transcriptional signals in the proximal promoter region of mammalian MCK genes.

Animals↗
PubMed1991

Aortico-left ventricular tunnel: long-term outcome after surgical repair.

Over a 14 year period, four children (three male, one female) underwent surgical correction of an aortico-left ventricular tunnel. All presented in infancy (age range 5 days to 9 months). The presenting feature was a systolic and diastolic murmur in all, one of whom developed heart failure within 2 weeks of presentation. In the first two patients, the echocardiographic findings were inconclusive and the diagnosis was confirmed at cardiac catheterization (at 10 and 23 months of age, respectively); the other two were diagnosed echocardiographically by two-dimensional and Doppler color flow imaging. All four patients underwent surgery by patch closure of the aortic end of the tunnel (three patients) or direct suture closure (one patient) and there were no deaths. The mean age at operation was 11 months. During a mean follow-up period of 71 months (range 2 to 157), three patients have clinical and echocardiographic evidence of trivial aortic valve regurgitation, which was noted in the immediate postoperative period in one and at early (less than 6 months) follow-up study in the other two. All are symptom-free, are taking no medications and are growing and developing normally. Aortico-left ventricular tunnel can be accurately diagnosed by echocardiography. In patients presenting in infancy, echocardiography also provides the necessary morphologic information to enable surgical correction without angiography. Early operation is associated with an excellent outcome, whereas repair at a later age is associated with a high incidence of residual aortic regurgitation requiring further surgery.

Aorta↗
PubMed1991

Cerebral arteriovenous malformations in the neonate: clinical presentation, diagnosis and outcome.

We reviewed the diagnostic features and clinical outcome of 7 consecutive neonates who were diagnosed to have cerebral arteriovenous malformations. All presented with cardiac failure, and a cranial bruit was heard in 6/7 patients. There was electrocardiographic evidence of myocardial ischemia in 6 patients. The diagnosis was established at cardiac catheterization, or by cardiac and cranial ultrasound. Three patients died of heart failure before definitive treatment. Despite early intervention, three of the remaining four patients died either during or immediately after embolization or ligation of the fistula. A cerebral arteriovenous malformation is a rare cause of neonatal heart failure. Despite prompt recognition and aggressive treatment, the outlook for symptomatic neonates is poor.

Angiography↗
PubMed1991

Aortopulmonary window with aortic origin of the right pulmonary artery.

Cross-sectional Doppler echocardiographic diagnosis of an aortopulmonary window with type B interrupted aortic arch, and anomalous origin of the right pulmonary artery from the ascending aorta was made in a 15-day-old neonate. This is the first known reported case of surgical repair for this rare association based on prospective echocardiographic diagnosis alone.

Abnormalities, Multiple↗
PubMed1991

Appendicular skeletal status and hip fracture in the elderly: 14-year prospective data.

Fourteen-year follow-up of 535 elderly people included in a British survey in 1973 revealed 23 incident hip fractures. The relationship between appendicular bone mass, assessed in the initial survey by metacarpal morphometry, and fracture risk was analyzed. There was an increased risk of hip fracture with declining metacarpal cortical index at baseline. The risk increase, however, was not statistically significant. It remained similar after adjustment was made for the reported prevalence of falls. These prospective data suggest that osteoporosis may contribute less to the risk of hip fracture in the very elderly than in younger individuals.

Age Factors↗
PubMed1991

Results of balloon pulmonary valvuloplasty as a palliative procedure in tetralogy of Fallot.

Balloon pulmonary valvuloplasty was attempted in 67 patients with tetralogy of Fallot at a median age of 5 months (range 0.03 to 52 months) for relief of cyanosis. In three patients, the valve could not be crossed and an aortopulmonary shunt was performed. In 35 patients, follow-up angiography was performed 3 to 30 months (average 12) after valvuloplasty. In 24 of these 35 patients (group A), the stenosis had been adequately palliated by valvuloplasty; the other 11 patients (group B) had required an aortopulmonary shunt 1 month (range 0 to 3 months) after valvuloplasty. The two groups were similar (p greater than 0.1) with respect to age at valvuloplasty, pulmonary anulus diameter, ratio of pulmonary artery to descending aorta diameter before valvuloplasty and interval to follow-up angiography. In contrast to patients in group B, patients in group A had a significant immediate improvement in systemic arterial oxygen saturation (p less than 0.01) and a significant increase in pulmonary anulus diameter at follow-up angiography (p less than 0.001). The growth of the branch pulmonary arteries was similar (p greater than 0.1) in the two groups. Among 42 patients who have had surgical correction, a transannular patch for right ventricular outflow tract reconstruction was used in 27 (64%); there was no difference between groups A and B with respect to its use. Eight patients died (three after repair) and death could not be directly attributed to valvuloplasty in any. Balloon valvuloplasty promotes growth of the pulmonary valve anulus and pulmonary arteries and is a useful alternative to an aortopulmonary shunt in patients with small pulmonary arteries or associated complex intracardiac defects.

Angiocardiography↗
PubMed1991

Mapping point mutations in the Drosophila rosy locus using denaturing gradient gel blots.

Mutations within the rosy locus of Drosophila were mapped using blots of genomic DNA fragments separated on denaturing gradient gels. DNA sequence differences between otherwise identical small rosy DNA fragments were detected among the mutants as mobility shifts on the blots. Mutations were mapped to within a few hundred base pairs of rosy sequence in 100 of 130 mutants tested--a 77% detection rate. The sequence changes in 43 rosy mutations are presented; all but six of these were single base changes. Thirty-four of 36 sequenced mutations induced by the alkylating agents N-ethyl-N-nitrosourea and ethyl methanesulfonate were transitions. All of the mutations mapped in the rosy transcription unit. Twenty-three of the 43 sequenced mutations change the predicted rosy gene polypeptide sequence; the remainder would interrupt protein translation (17), or disrupt mRNA processing (3).

Animals↗
PubMed1991

Reproducibility of histories of low-back pain obtained by self-administered questionnaire.

To test the repeatability of information about low-back pain elicited by self-administered questionnaire, histories obtained from 225 men and women were compared at an interval of 12 months. There was good agreement on whether subjects had ever suffered low-back pain (k = 0.82) and on whether the pain had ever led to consultation with a general practitioner (k = 0.76) or absence from work (k = 0.76). Information about the speed of onset of symptoms as well as histories of associated sciatica and disability for everyday activities were less reproducible. Epidemiologic studies based on such data must be interpreted with appropriate caution.

Adult↗
PubMed1991

Buoyant density studies of several mecillinam-resistant and division mutants of Escherichia coli.

The buoyant density of wild-type Escherichia coli cells has previously been reported not to vary with growth rate and cell size or age. In the present report we confirm these findings, using Percoll gradients, and analyze the recently described lov mutant, which was selected for its resistance to mecillinam and has been suggested to be affected in the coordination between mass growth and envelope synthesis. The average buoyant density of lov mutant cells was significantly lower than that of wild-type cells. Similarly, the buoyant density of wild-type cells decreased in the presence of mecillinam. The density of the lov mutant, like that of the wild type, was invariant over a 2.8-fold range in growth rate. In this range, however, the average cell volume was also constant. Analysis of buoyant density as a function of cell volume in individual cultures revealed that smaller (newborn) lov mutant cells had higher density than larger (old) cells; however, the density of the small cells never approached that of the wild-type cells, whose density was independent of cell size (age). A pattern similar to that of lov mutant cells was observed in cells carrying the mecillinam-resistant mutations pbpA(Ts) and rodA(Ts) and the division mutation ftsI(Ts) at nonpermissive temperatures as well as in wild-type cells treated with mecillinam, but not in mecillinam-resistant crp or cya mutants.

Amdinocillin↗
PubMed1991

Natural and synthetic DNA elements with the CArG motif differ in expression and protein-binding properties.

DNA elements with the CC(A/T)6GG, or CArG, motif occur in promoters that are under different regulatory controls. CArG elements from the skeletal actin, c-fos, and myogenin genes were tested for their abilities to confer tissue-specific expression on reporter genes when the individual elements were situated immediately upstream from a TATA element. The c-fos CArG element, also referred to as the serum response element (SRE), conferred basal, constitutive expression on the test promoter. The CArG motif from the myogenin gene was inactive. The skeletal actin CArG motif functioned as a muscle regulatory element (MRE) in that basal expression was detected only in muscle cultures. Muscle-specific expression from the 28-bp MRE and the 2.3-kb skeletal actin promoter was trans repressed by the Fos and Jun proteins. The expression and factor-binding properties of a series of synthetic CArG elements were analyzed. Muscle-specific expression was conferred by perfect 28-bp palindromes on the left and right halves of the skeletal actin MRE. Chimeric elements of the skeletal actin MRE and the c-fos SRE differed in their expression properties. Muscle-specific expression was observed when the left half of the MRE was fused to the right half of the SRE. Constitutive expression was conferred by a chimera with the right half of the MRE fused to the left half of the SRE and by chimeras which exchanged the central CC(A/T)6GG sequences. At least three distinct proteins specifically bound to these CArG elements. The natural and synthetic CArG elements differed in their affinities for these proteins; however, muscle-specific expression could not be attributed to differences in the binding of a single protein. Furthermore, the MRE did not bind MyoD or the myogenin-E12 heterodimer, indicating that muscle-specific expression from this element does not involve a direct interaction with these helix-loop-helix proteins. These data demonstrate that the conserved CArG motifs form the core of a family of functionally different DNA regulatory elements that may contribute to the tissue-specific expression properties of their cognate promoters.

Actins↗
PubMed1991

Identification of single-stranded-DNA-binding proteins that interact with muscle gene elements.

A sequence-specific DNA-binding protein from skeletal-muscle extracts that binds to probes of three muscle gene DNA elements is identified. This protein, referred to as muscle factor 3, forms the predominant nucleoprotein complex with the MCAT gene sequence motif in an electrophoretic mobility shift assay. This protein also binds to the skeletal actin muscle regulatory element, which contains the conserved CArG motif, and to a creatine kinase enhancer probe, which contains the E-box motif, a MyoD-binding site. Muscle factor 3 has a potent sequence-specific, single-stranded-DNA-binding activity. The specificity of this interaction was demonstrated by sequence-specific competition and by mutations that diminished or eliminated detectable complex formation. MyoD, a myogenic determination factor that is distinct from muscle factor 3, also bound to single-stranded-DNA probes in a sequence-specific manner, but other transcription factors did not. Multiple copies of the MCAT motif activated the expression of a heterologous promoter, and a mutation that eliminated expression was correlated with diminished factor binding. Muscle factor 3 and MyoD may be members of a class of DNA-binding proteins that modulate gene expression by their abilities to recognize DNA with unusual secondary structure in addition to specific sequence.

Animals↗
PubMed1991

The myosin light chain enhancer and the skeletal actin promoter share a binding site for factors involved in muscle-specific gene expression.

The myosin light chain (MLC) 1/3 enhancer (MLC enhancer), identified at the 3' end of the skeletal MLC1/3 locus, contains a sequence motif that is homologous to a protein-binding site of the skeletal muscle alpha-actin promoter. Gel shift, competition, and footprint assays demonstrated that a CArG motif in the MLC enhancer binds the proteins MAPF1 and MAPF2, previously identified as factors interacting with the muscle regulatory element of the skeletal alpha-actin promoter. Transient transfection assays with constructs containing the chloramphenicol acetyltransferase reporter gene demonstrated that a 115-bp subfragment of the MLC enhancer is able to exert promoter activity when provided with a silent nonmuscle TATA box. A point mutation at the MAPF1/2-binding site interferes with factor binding and abolishes the promoter activity of the 115-bp fragment. The observation that an oligonucleotide encompassing the MAPF1/2 site of the MLC enhancer alone cannot serve as a promoter element suggests that additional factor-binding sites are necessary for this function. The finding that MAPF1 and MAPF2 recognize similar sequence motifs in two muscle genes, simultaneously activated during muscle differentiation, implies that these factors may have a role in coordinating the activation of contractile protein gene expression during myogenesis.

Actins↗
PubMed1991

Aortic-ventricular tunnel in a neonate: diagnosis and management based on cross sectional and colour Doppler ultrasonography.

A five day old symptom free neonate was referred for assessment of a to and fro murmur associated with large volume pulses. Cross sectional echocardiography and colour flow mapping confirmed the diagnosis of an aortic-ventricular tunnel with forward flow into the aorta and regurgitant flow into the ventricle through both the tunnel and the dilated aortic valve ring. Surgical correction by patch closure of the aortic end of the tunnel was successfully undertaken two weeks later without any additional investigations. Postoperative echocardiography and colour flow imaging showed no aortic regurgitation and normal left ventricular dimensions and function.

Aorta↗
PubMed1991

Interaction of height and mechanical loading of the spine in the development of low-back pain.

The relation of low-back pain to height and physical activity was examined among 2667 British men and women aged 20-59 years and selected from the general population. Information about occupational activities, height, and lifetime history of low-back pain was obtained from a postal questionnaire. The lifetime prevalence of low-back pain was 58.3%. After allowance for other occupational activities, the onset of low-back pain was strongly associated with heavy lifting at work (men: relative risk (RR) 2.0, 95% confidence interval (95% CI) 1.4-2.8; women: RR 2.2, 95% CI 1.3-3.5). For the men there was also an association with digging (RR 1.6, 95% CI 1.1-2.3). Risk of low-back pain increased with height among the men but not among the women. The risks associated with heavy lifting and digging were greater for the short than for the tall men. Thus the data provide no justification for excluding tall men from heavy manual tasks, despite their greater susceptibility to back problems.

Adult↗
PubMed1991

Ambulatory care.

Explore the source record for details and available documents.

Ambulatory Care↗