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Biomedical subjects

C Hayward

Publications and source records attributed to C Hayward.

At least 109 records · Page 6Linked to original sources
PubMed1989

Characterization of porin and ompR mutants of a virulent strain of Salmonella typhimurium: ompR mutants are attenuated in vivo.

The ompC, ompD, and ompF genes encode the three major porins of Salmonella typhimurium. ompR encodes a positive regulator required for the expression of ompC and ompF. Transposon-generated mutations in ompC, ompD, ompF, and ompR were introduced into the S. typhimurium mouse virulent strain SL1344 by P22-mediated transduction. Following preliminary characterization in vitro, the strains were used to challenge BALB/c mice by using the oral or intravenous route. Strains harboring ompC or ompF mutations were as virulent as SL1344 after oral challenge. Strains harboring ompD mutations had a slight reduction in virulence. In contrast, ompR mutants failed to kill BALB/c mice after oral challenge and the intravenous 50% lethal dose was reduced by approximately 10(5). The ompR mutants persisted in murine tissues for several weeks following oral or intravenous challenge. Furthermore, mice orally immunized with these ompR mutant strains were well protected against challenge with virulent SL1344.

Administration, Oral↗
PubMed1989

Noninvasive determination of age-related changes in the human arterial pulse.

Arterial pressure waves were recorded noninvasively from the carotid, radial, femoral, or all three of these arteries of 1,005 normal subjects, aged 2-91 years, using a new transcutaneous tonometer containing a high fidelity Millar micromanometer. Waves were ensemble-averaged into age-decade groups. Characteristic changes were noted with increasing age. In all sites, pulse amplitude increased with advancing age (carotid, 91.3%; radial 67.5%; femoral, 50.1% from first to eighth decade), diastolic decay steepened, and diastolic waves became less prominent. In the carotid pulse, there was, in youth, a second peak on the downstroke of the waves in late systole. After the third decade, this second peak rose with age to merge with and dominate the initial rise. In the radial pulse, a late systolic wave was also apparent, but this occurred later; with age, this second peak rose but not above the initial rise in early systole, even at the eighth decade. In the femoral artery, there was a single systolic wave at all ages. Aging changes in the arterial pulse are explicable on the basis of both an increase in arterial stiffness with increased pulse-wave velocity and progressively earlier wave reflection. These two factors may be separated and effects of the latter measured from pressure wave-contour analysis using an "augmentation index," determined by a computer algorithm developed from invasive pressure and flow data. Changes in peak pressure in the central (carotid) artery show increasing cardiac afterload with increasing age in a normal population; this can account for the cardiac hypertrophy that occurs with advancing age (even as other organs atrophy) and the predisposition to cardiac failure in the elderly. Identification of mechanisms responsible offers a new approach to reduction of left ventricular afterload.

Aging↗
PubMed1989

Plasma lipid levels in patients with panic disorder or agoraphobia.

Plasma lipids were measured in 102 subjects with panic disorder or agoraphobia. In women, but not men, a significantly higher than expected number of subjects had cholesterol values that exceeded the 75th percentile of national reference values for their sex and age.

Adult↗
PubMed1989

Panic attacks in young adolescents.

The lifetime prevalence of interview-determined four-symptom panic attacks in 95 ninth graders was 11.6%. Those with panic attacks were significantly more depressed, were significantly more likely to have separated or divorced parents, and tended to be more likely to have tried cigarette smoking.

Adolescent↗
PubMed1988

The sonographic features and implications of fetal pleural effusions.

Pleural fluid was detected by ultrasound in three fetuses as an anechoic area surrounding the echogenic fetal lung. In one fetus the underlying lung was small, immobile and of abnormal contour; death occurred in the neonatal period and the lung was found to be hypoplastic. In two other fetuses the lungs appeared sonographically normal, being mobile with normal contours. Both survived, one following spontaneous intra-uterine resolution of the effusion and the other after early neonatal intervention prompted by the antenatal diagnosis. Sonography can detect pleural fluid in utero and may permit differentiation between normal underlying lung and pulmonary hypoplasia. We recommend serial scanning to detect early adverse effects of pleural effusion upon the fetus and to plan management changes.

Adult↗
PubMed1988

A comparison between area and volume measurements of the mastoid air spaces in normal temporal bones.

In a study of 26 normal cadaveric temporal bones, a significant correlation was found between the area of the mastoid air spaces assessed from a conventional lateral radiograph and the mastoid volume as determined using high resolution computed tomography. The relationship, which was found to be linear, is of the form V = 0.82 A + 0.13. The correlation coefficient is 0.95 with a residual standard deviation about the regression of 1.14 cm3. It is apparent, therefore, that an accurate assessment of the mastoid air space volume can be obtained by means of a simple and routinely requested investigation, i.e. the 35 degree lateral oblique radiograph.

Humans↗
PubMed1988

Clinical outcome of fetal uropathy.

Thirty seven infants (27 boys and 10 girls) whose uropathy had been diagnosed antenatally were reviewed at a mean age of 24.4 months. Antenatal ultrasonography was found to be an accurate detector of renal disease, as uropathy was subsequently confirmed in 33 of the 37 infants (89%). A smaller proportion of patients required operations than in other series reported. Shortly after birth the kidney undergoes physiological adjustments and investigation may be carried out too soon. It should be delayed, especially if the infant is well. The timing of postnatal ultrasonography is important and the advice of a paediatric urologist should be sought before investigations are carried out.

Female↗
PubMed1988

Expression pattern of two related cystic fibrosis-associated calcium-binding proteins in normal and abnormal tissues.

This paper reports further study of the identity and function of a protein shown to be elevated in serum from cystic fibrosis (CF) patients and clinically normal heterozygotes. Monoclonal antibodies, specifically recognizing the tentatively named cystic fibrosis antigen (CFAg), were produced. Immunoaffinity purification of CFAg from several sources revealed two components: 11 x 10(3) and 14 x 10(3) Mr protein. cDNA clones corresponding to each protein have been isolated. Data-base comparisons of the deduced amino acid sequences suggest that both genes encode related but distinct calcium-binding proteins. We propose the name calgranulin A and B, for the 11 x 10(3) and 14 x 10(3) Mr components, respectively. It is clear from the assignment of the calgranulin genes to chromosome 1 that neither is the product of the mutant CF gene, which maps to chromosome 7. We have used the monoclonal antibodies to study the tissue distribution of the two proteins in a wide-ranging immunohistological survey. Where possible the pattern of expression was confirmed by RNA blot analysis. Strong calgranulin expression in granulocytes was confirmed. In addition to myeloid cells, a restricted subset of normal stratified squamous epithelia were found to be calgranulin-positive. These included tongue, oesophagus and buccal cells, the last of which has been shown to have altered calmodulin activity in CF patients. Using indirect alkaline phosphatase staining, tissue sections of lung, pancreas and skin (normally considered sites where the CF defect is expressed) were not calgranulin-positive. However, by indirect immunofluorescence, nasal polyp sections showed weak patchy calgranulin expression in some epithelial cells, and stronger, higher frequency expression when such cells were briefly cultured.(ABSTRACT TRUNCATED AT 250 WORDS)

Antibodies, Monoclonal↗
PubMed1988

Immunoglobulin levels in maternal and neonatal sera from normal and abnormal pregnancies.

IgG, IgM and albumin levels in sera from neonates with open neural tube defects (NTD), other congenital malformations, and matched controls were measured, as were levels in sera from their mothers. Neonates with NTD had significantly lower serum IgG levels than 22 control neonatal sera. On the other hand, the mothers of these neonates with NTD had elevated serum IgG levels resulting in a striking imbalance in the mother/neonate IgG ratio. In contrast to IgG, IgM levels in maternal and neonatal sera from the NTD group were within normal values. The maternal albumin levels were however significantly increased reflecting hemoconcentration. In sera from 3 neonates born with other congenital malformations (hydrocephaly, caudal appendage and sacral tumor) the only significant changes were higher IgM levels and lower mother/neonate IgM ratios. These results are discussed in the context of materno-fetal immune responses, placental transfer of plasma proteins and the possible involvement of immunoglobulins in fetal malformation.

Congenital Abnormalities↗
PubMed1988

Functional and space programming.

In this article, the author expands the earlier stated case for functional and space programming based on objective evidence of user needs. It provides an in-depth examination of the logic and processes of programming as a continuum which precedes, then parallels, architectural design.

Documentation↗
PubMed1987

Treadmill exercise test and ambulatory measures in panic attacks.

Treadmill exercise test performance and ambulatory heart rate and activity patterns of 40 patients with panic attacks were compared with 20 age-matched controls (control group 1) and 20 nonexercising controls (control group 2). All patients underwent a symptom-limited exercise stress test. Panic attack patients and control group 1 wore an ambulatory heart rate/activity monitor for up to 3 days. Panic patients had a significantly higher heart rate at 4 and 6 METS than either control group. The max METS were 11.2 +/- 2.3, 13.5 +/- 2.3 and 11.2 +/- 1.8 for the panic attack patients and control groups 1 and 2, respectively. One panic patient had ischemia on the treadmill at 12 METS. Panic patients had a significantly higher standing heart rate than controls. Furthermore, 11 of 39 panic patients had tachycardia on standing compared with 3 of 40 controls. Panic attack patients had higher wake and sleep heart rates than control group 1, but the differences were not significant. These results are consistent with autonomic dysfunction in panic patients but may also be due to differences in physical conditioning. The treadmill can be useful for reassuring patients and for identifying the rare patient with ischemia on exercise.

Adult↗
PubMed1987

Serum concentrations of a granulocyte-derived calcium-binding protein in cystic fibrosis patients and heterozygotes.

Serum samples from cystic fibrosis homozygotes and heterozygotes contain elevated levels of a protein, known as cystic fibrosis antigen, which is synthesized primarily in granulocytes. We have produced monoclonal antibodies against cystic fibrosis antigen and developed a sensitive two-site immunoassay. Antigen levels were evaluated in serum samples from 50 cystic fibrosis homozygotes, 34 heterozygotes, 60 healthy controls and 25 disease controls. Simultaneous measurement was made of another granulocyte-derived serum protein, lactoferrin, and also of the acute-phase reactant, C-Reactive Protein. Attempts to use the concentrations of cystic fibrosis antigen in serum to distinguish cystic fibrosis patients from heterozygotes were unsuccessful, even when these concentrations were expressed as a ratio with lactoferrin or with C-Reactive Protein. However, examination of the ratio of cystic fibrosis antigen to lactoferrin in serum samples from cystic fibrosis heterozygotes suggests that there is some specific association between this antigen and the cystic fibrosis gene.

Antibodies, Monoclonal↗
PubMed1987

Inter-sterno-costo-clavicular ossification.

The clinical and radiological features of four patients with inter-sterno-costo-clavicular ossification are described. The process was associated with established seronegative spondyloarthropathy in three cases of whom four had long standing psoriasis, the other having ankylosing spondylitis. In the fourth case no associated arthropathy was present. A review of the literature is presented.

Adult↗
PubMed1987

The influence of temporal bone anatomical variation upon the caloric stimulus.

This study involved a comparison of temperature changes occurring in isolated cadaveric temporal bones as a result of caloric stimulation, with information gained from radiological examination of the bones by means of high resolution computed tomographic scanning. This was performed in order to investigate the complex nature of heat transfer within the temporal bone and the influence which anatomical variations may have upon the accuracy of evaluation of vestibular function by means of the caloric test. No significant correlation could be found between the maximum temperature change occurring across the lateral semicircular canal and any of the parameters obtained from radiological assessment except for the diameter of the internal auditory meatus. It was deduced that an intra-subject difference in the diameters of the internal auditory meatus of 0.5 mm would introduce an absolute error in the evaluation of percentage canal paresis of 10%. Since normal intra-subject differences in internal meatus diameter can exceed 0.5 mm, this finding was considered to be highly significant.

Caloric Tests↗
PubMed1986

Immunocytochemical localization of cytochrome P-450 in hepatic and extra-hepatic tissues of the rat with a monoclonal antibody against cytochrome P-450 c.

The cellular distribution of cytochrome P-450 has been studied in the liver and a number of extrahepatic tissues in the rat by immunocytochemistry, using an antibody raised against cytochrome P-450 form c. Immunoreactive cytochrome P-450, most probably form c, was found in the proximal tubules of the kidney, in the Clara cells of the lung, and in the olfactory epithelium and Bowman's glands of the olfactory tissue, in addition to its location in the liver. Immunoreactive cytochrome P-450 was not found in the small intestine, the testes or the adrenal gland, although these organs are known to contain isoenzymes of cytochrome P-450. The use of antibody titration enabled the effects of phenobarbitone, beta-naphthoflavone and clofibrate on the content and distribution of immunoreactive cytochrome P-450 to be studied in both the liver and in the other organs discussed. Phenobarbitone induces epitope-specific cytochrome P-450 in the centrilobular cells of the liver but has no effect in any of the other tissues studied. Clofibrate is without effect on the levels of immunoreactive cytochrome P-450 in any of the tissues studied. In contrast, beta-naphthoflavone induces immunoreactive cytochrome P-450 in the periportal region of the liver, and also in the Clara cells of the lung, in the enterocytes of the small intestine and in the proximal tubules of the kidney. Of all of the tissues studied, in which immunoreactive cytochrome P-450 could be detected, only the olfactory epithelium failed to undergo enzyme induction following treatment with beta-naphthoflavone.

Adrenal Glands↗
PubMed1986

Multicentre trial of ethamsylate for prevention of periventricular haemorrhage in very low birthweight infants.

The effectiveness of ethamsylate in the prevention of periventricular haemorrhage (PVH) in very low birthweight infants was evaluated by means of a multicentre, placebo-controlled, double-blind trial. In 330 infants without evidence of PVH on initial cranial ultrasound examination there was little difference between ethamsylate and placebo groups with respect to subependymal haemorrhage, but intraventricular and parenchymal haemorrhages developed in 30/162 infants (18.5%) in the treated group, compared with 50/168 (29.8%) in the control group (p less than 0.02). The incidence of intraventricular and parenchymal haemorrhage in survivors was 20/137 (14.6%) in the ethamsylate group and 37/146 (25.3%) in the controls (p less than 0.05). In 30 infants with evidence of PVH on the initial scan, ethamsylate treatment seemed to limit parenchymal extension. Analysis of the total cohort of 360 infants showed that the proportion of infants in whom an increase of two or more grades of severity of PVH was recorded during the trial was lower in the treated than in the placebo group (p less than 0.01). No adverse effects were attributed to ethamsylate therapy. The reported incidence of patent ductus arterious was lower in the treated than in the placebo group (p less than 0.02). Mortality was similar in the two groups.

Benzenesulfonates↗