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Biomedical subjects

S Smith

Publications and source records attributed to S Smith.

At least 577 records · Page 32Linked to original sources
PubMed1993

Pediatric trauma patients in an 'adult' trauma center.

The injury patterns, age distribution, and outcome of pediatric patients (age < 15 years) treated in an "adult" trauma center is incompletely defined. A total of 1115 pediatric trauma patients (9.6% total trauma admissions) treated over a 6-year period in a level I suburban trauma center without a pediatric trauma service or a pediatric surgeon were reviewed for age distribution; injury mechanism, injury pattern, and injury severity; surgical procedures; disposition; and mortality. All charts were subject to internal and external peer review, including five site surveys. Resuscitation, surgery, critical care, and stepdown management were provided by a trauma team led by in-house attending trauma surgeons (mean PGY = 20). Of the patients 22% were preschool (age 0-4 years), and 34% were adolescent (age 12-14 years); the mechanism was blunt (96%), with motor vehicular crash being the most frequent; the mean ISS was 11.1, with 39% of ISSs > 9; significant injuries (AIS score > or = 3) of the head and extremities were dominant; 3.9% of patients underwent laparotomy, primarily for injuries to the bowel, spleen, and liver. There was only one laparotomy in the 0-4 year age group. The mean length of stay of patients was 6.2 days, with 38% requiring time in the ICU. Of the patients, 90% were discharged home; the treated trauma patient mortality rate was 25 of 988, or 2.5%; 92% of these died of nonsurvivable head injuries. No deaths were judged preventable. There was no significant difference of noncompliance for the pediatric patients when compared with the adult population in five trauma audit filters.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1993

One-hour exposure to moderate illuminance (500 lux) shifts the human melatonin rhythm.

Salivary melatonin levels were measured in 12 healthy volunteers in order to determine whether a moderate light intensity, which suppresses the nocturnal rise of melatonin, was able to shift the melatonin rhythm. The samples were collected at 1-hr intervals under lighting of < 100 lux (experiment 1) or < 10 lux (experiment 2). The control melatonin profiles were determined during the first night. In the second night the subjects were exposed to light of 500 lux for 60 min during the rising phase of melatonin synthesis. The third series of samples was collected during the third night. The mean decrease of melatonin levels by the exposure to light was 56% of the prelight concentrations. The melatonin onset times were delayed significantly (about 30 min) the night after the exposure to light. The melatonin offset times tended to be delayed in experiment 2. The shifts of the melatonin offset correlated positively with the amount of the melatonin suppression. The results suggest that a relatively small and short lasting light-induced interruption of melatonin synthesis may affect the melatonin rhythm in humans.

Adult↗
PubMed1993

Immunocytochemical and lectin histochemical study of neuronal lesions in autonomic ganglia of horses with grass sickness.

Equine grass sickness (EGS) is a primary dysautonomia characterised pathologically by lesions in autonomic ganglia, enteric plexi and specific nuclei in the CNS. Immunocytochemistry and lectin histochemistry of the autonomic ganglia were used to determine whether abnormalities can be detected in specific proteins or cellular organelles. EGS ganglia contained a mixture of morphologically normal and abnormal neurons, the former appearing identical to cells from control animals. Affected cells showed marked disturbances in neurofilament (NF) proteins and beta-tubulin, major components of the cytoskeleton; in most neurons immunoreactivity was reduced or absent while the distribution was altered in the remainder. Staining for neuron-specific enolase, a pan-neuronal marker, was severely reduced or absent, as was reactivity for the catecholaminergic enzyme tyrosine hydroxylase. However, affected neurons showed a marked increase in dopamine-beta-hydroxylase (D beta H), another enzyme associated with noradrenaline synthesis. Wheat germ agglutinin and Griffonia simplicifolia B4 lectin histochemistry was used to label membranes of the Golgi apparatus, which stained as discrete curvilinear perinuclear profiles. All affected neurons showed abnormalities with either complete loss of reaction or amorphous centrally located lectin staining. The results indicate perturbation in a wide variety of cytoplasmic and cytoskeletal proteins. In the majority of instances there is a decrease in stainable protein; the increase in D beta H may indicate a failure to be transported down the axon with resultant accumulation in the perikaryon. Loss of a recognisable Golgi structure appears to be an early event in the neuropathology of EGS.

Animals↗
PubMed1993

Effect of type III group B streptococcal capsular polysaccharide on invasion of respiratory epithelial cells.

Group B streptococcal (GBS) capsular polysaccharide is an important virulence factor, and its role in invasion of cultured respiratory epithelial cells was investigated. A type III GBS clinical isolate, COH1, and asialo and unencapsulated isogenic transposon capsule mutants of it were compared in an in vitro invasion assay. The results demonstrated that capsule attenuated the invasion process. Invasion was not affected when the A549 epithelial cells were preincubated with purified type III GBS capsular polysaccharide. Polyclonal type III GBS capsule antibody inhibited invasion by COH1 but did not affect invasion by the capsule mutants. Serotypes Ia, Ib, Ia/c, II, and III all invaded respiratory epithelial cells but demonstrated some strain variation in magnitude of invasion. These observations led us to conclude that type III capsular polysaccharide was not essential for invasion of respiratory epithelial cells by GBS and that bacterial factors other than capsule were responsible for respiratory epithelial cell invasion.

Bacterial Toxins↗
PubMed1993

Mechanisms of action of Pseudomonas aeruginosa pyocyanin on human ciliary beat in vitro.

Pyocyanin is a blue redox active pigment produced by Pseudomonas aeruginosa. It is present at concentrations of up to 10(-4) M in sputa from patients with cystic fibrosis and bronchiectasis who are heavily colonized with this organism. Pyocyanin, at physiologically relevant concentrations, slows human nasal ciliary beat frequency (CBF) in vitro and leads to disruption of the epithelium. Pyocyanin-induced slowing of CBF after 2 h was associated with a significant fall in intracellular cyclic AMP (cAMP) (90%) and ATP (66%) and was reversible after the pyocyanin was removed by washing. These effects were not mediated through interaction with neutrophils. The pyocyanin-induced fall in CBF was not affected by EGTA [ethylene glycol-bis(beta-aminoethyl ether)-N,N,N',N'-tetraacetic acid], pyrazinamide, 8-phenyltheophylline, indomethacin, or antioxidants, including catalase (500 U/ml), superoxide dismutase, and N-acetylcysteine. Ciliary slowing was, however, prevented (> 70%) by isobutylmethylxanthine and forskolin, both of which increase intracellular cAMP, and also by the cAMP analog, dibutyryl cAMP. There was also a concomitant protection against the fall in both cAMP and ATP. These agents also delayed the onset of epithelial disruption associated with pyocyanin treatment. In contrast, treatment with the iron chelator desferrioxamine prevented epithelial disruption, although it had no effect on pyocyanin-induced slowing of CBF. It appears that ciliary slowing can be dissociated from epithelial disruption and that the effects of pyocyanin on CBF are associated with a fall in both intracellular cAMP and ATP.

Adenosine Triphosphate↗
PubMed1993

Use of polymerase chain reaction for diagnosis of picornavirus infection in subjects with and without respiratory symptoms.

Rhinoviruses and enteroviruses are the major members of the picornavirus genus that cause human disease. We compared the polymerase chain reaction and viral culture for the identification of picornaviruses in nasal aspirates from children during episodes of respiratory symptoms and when asymptomatic and from asymptomatic adults. One hundred eight children, aged 9 to 11 years, completed a year-long study. Within 24 to 48 h of a report of respiratory symptoms, a nasal aspirate was taken in the home. Nasal aspirates were also taken from 65 of the children and from 33 normal adults when they had been free of respiratory symptoms for at least 2 weeks. Picornaviruses were isolated by culture for three passages in Ohio HeLa cells in rolling tubes at 33 degrees C and pH 7.0. For the polymerase chain reaction, duplicate 50-microliters samples were amplified with conserved primers from the 5' noncoding region. Picornaviruses generated approximately 380-bp bands in agarose gel electrophoresis; the specificity of these bands was confirmed by filter hybridization with a conserved internal probe. Picornaviruses were isolated by culture in 47 (46 rhinoviruses) of 292 symptomatic episodes (16%), whereas the polymerase chain reaction identified picornavirus genomic material in 146 episodes (50%), including all but one of the culture-positive episodes. As for asymptomatic samples, eight (12%) children and two (4%) adults were positive by the polymerase chain reaction, whereas only one child's specimen was positive by culture. This polymerase chain reaction assay represents a clear advance in the identification of picornavirus infection, with a detection rate threefold greater than the virus culture method.

Adult↗
PubMed1993

Use of recombinant human parvovirus B19 antigens in serological assays.

AIMS--To compare the sensitivity, specificity, and practicality of recombinant proteins in serological tests for the detection of human parvovirus B19 IgG and IgM. METHODS--Indirect enzyme linked immunosorbent assays using B19 structural proteins expressed in Escherichia coli were developed for the detection of B19 specific IgG and IgM (rELISA-G and rELISA-M). Cells infected with baculovirus expressing B19 structural proteins were also used in an indirect immunofluorescence assay for IgG and IgM antibodies (IFA-G and IFA-M). Antibody capture radioimmunoassays for IgG and IgM (GACRIA and MACRIA) were used as comparative assays. RESULTS--Twenty nine pools of intravenous immunoglobulin were clearly positive for B19 IgG by rELISA-G and contained low IgG titres by GACRIA. From 113 samples tested by all methods, sensitivities of 92% (77/84) and 97% (68/70) were obtained for ELISA and immunofluorescence, respectively, when compared with GACRIA. One hundred and sixteen samples from patients presenting with rash or arthralgia were compared by MACRIA, rELISA-M, and IFA-M. Sensitivities of both recombinant tests were more than 95%. Despite pretreatment to remove IgG or rheumatoid factor, false positive results were a problem in the rELISA-M but were not seen with the IFA-M. CONCLUSIONS--The limited supply of native antigen has severely restricted the wide application of serology for parvovirus B19. The use of recombinant antigens permitted the introduction of local screening tests which had many advantages, including quicker results and relief of the burden on the Reference Laboratory. The use of rELISA-M for sensitivity and IFA-M for specificity and confirmation proved a useful and practical combination for diagnosis of recent infection with B19, and rELISA-G allowed the immune response to be determined in selected populations.

Adolescent↗
PubMed1993

The influence of terfenadine and pseudo-ephedrine alone and in combination on allergen-induced rhinitis.

Nasal biopsies to naturally occurring allergic rhinitis demonstrate ultrastructural evidence of mast cell degranulation. Consistent with this, H1 antihistamines are clinically efficacious in this disorder. The nasal symptoms of itch, sneeze and discharge are, however, more susceptible to this mode of therapy than is nasal blockage. As nasal blockage is vascular, the combination of an H1 antihistamine and a decongestant has a logical rationale. To investigate the efficacy of such a combination, the influence of pretreatment with terfenadine, 60 mg, pseudo-ephedrine, 120 mg, Seldane-d (a registered trademark of Marion Merrell Dow)--a combination of pseudo-ephedrine, 120 mg, and terfenadine, 60 mg,--and matched placebo was objectively investigated on the nasal response to allergen in grass-pollen-sensitive seasonal rhinitic subjects (7 males, 7 females, age 19-56 years) in a double-blind, placebo-controlled, 4-period cross-over study. Seldane-D was significantly better than placebo in all efficacy measurements: nasal itch (p < 0.02), sneezing (p < 0.01), discharge (p < 0.01) and blockage (p < 0.003). The terfenadine component of Seldane-D contributed predominantly to the reduction in itch, sneeze and discharge (p < 0.01) while the pseudo-ephedrine component primarily contributed to the nasal airway effects (p < 0.04). These results indicate that the combination of terfenadine and pseudo-ephedrine as a single oral medication is complementary.

Adult↗
PubMed1993

The role of transesophageal echocardiography in identifying anomalous coronary arteries.

BACKGROUND: The study objective was to evaluate the role of transesophageal echocardiography in identifying the origin of anomalous coronary arteries and confirming their course in relation to the great vessels. The diagnosis of coronary anomalies is made by angiography. The anomalous left main artery with a course between the pulmonary artery and the aorta has been associated with myocardial infarction and sudden death. The course of these anomalous coronary arteries is difficult to demonstrate by angiography alone. METHODS AND RESULTS: Nine patients with angiographically confirmed anomalous coronary arteries were studied by transesophageal echocardiography with color flow Doppler. The abnormal origin of the anomalous coronary arteries was confirmed by transesophageal echocardiography in all nine patients. In four patients, the left main coronary artery originated from the right sinus of Valsalva. In all of these patients, transesophageal echocardiography demonstrated the course of the anomalous left main coronary artery between the aorta and pulmonary artery better than angiography. Other anomalies that were visualized included two patients with origin of the right coronary arteries from the left aortic sinus, one patient with origin of the left anterior descending from the right sinus, one patient with origin of circumflex from the right sinus, and one patient with origin of the left main coronary artery from the pulmonary artery. CONCLUSIONS: Transesophageal echocardiography is a useful noninvasive test for diagnosing anomalous origin of the coronary arteries. Furthermore, it is a valuable adjunct to angiography in demonstrating the abnormal course of the left main coronary artery interposed between the aorta and the pulmonary artery, a potentially life-threatening entity.

Aged↗
PubMed1993

The changing role of CHCs (community health councils).

Peter Dunham and Sally Smith have experienced at first hand the changing role of community health councils and the opportunities that exist for collaborative working arrangements. Here, they define the progress that can be made in a relatively short period of time when empathy and trust exists between a CHC and its local health authority.

Community-Institutional Relations↗
PubMed1993

RNA synthesis in porcine blastomere nuclei introduced into in vitro matured ooplasm.

The objective was to investigate the RNA synthesis in porcine blastomere nuclei upon transplantation into in vitro matured enucleated oocytes. Nuclei from 2- to 8-cell porcine embryos were introduced into the ooplasm of in vitro matured and enucleated porcine oocytes by electrofusion, and the resultant reconstructed embryos were cultured in vitro. Before fusion or at different intervals after this event embryos were incubated with [3H]-uridine, fixed, and histologically processed for autoradiography in order to detect RNA synthesis. About two thirds of the embryos were considered to depict normal development. All blastomeres displayed pronounced RNA synthesis before fusion, at 3 and 9 h after fusion the synthesis decreased or ceased, and at 24-49 h some embryos resumed synthesis at the 1- to 2-cell stage.

Animals↗
PubMed1993

High throughput DNA sequencing using an automated electrophoresis analysis system and a novel sequence assembly program.

The combination of high-resolution scanning, image-databasing technology and sequence assembly software makes it possible to assemble contiguous overlapping sequences of DNA in a fraction of the time required by manual methods. This paper describes and evaluates an assembly program that rapidly generates contigs from scanned images and provides a unique ability to verify disagreements between overlapping strands or fragments of complementary DNA sequences on-screen, further increasing sequencing throughput.

Base Sequence↗
PubMed1993

Mitosis and protein synthesis 4 turnover of short- and long-lived proteins during the cell cycle of synchronized L-132 and HeLa S-3 cells.

Turnover rates of short- and long-lived proteins throughout the cell cycle were measured in two established mammalian cell lines, L-132 and HeLa S-3, using both selection and induction synchronization. Short-lived, newly synthesized proteins turned over at the same rate during all stages of the cell cycle when this rate was expressed as a percentage of total labelling of proteins present at the start of the chase. Since fewer proteins were made in M-phase, the absolute turnover rate was probably reduced to a small degree during division itself, indicating a close co-ordination between synthesis and degradation. In contrast, long-lived proteins showed a considerable reduction in their rate of turnover specifically during M-phase. One possible explanation for the reduced degradation of long-lived protein is the suppression of lysosomal activity during division, with no apparent effect on the turnover of short-lived proteins which is due to a non-lysosomal system.

Cell Cycle↗