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Biomedical subjects

C Bell

Publications and source records attributed to C Bell.

At least 127 records · Page 7Linked to original sources
PubMed1994

Views of dental patients about the education and practice of dentists.

The opinions of 253 adult U.K. dental patients were sought as to the scope of dental education. Most appreciated this was a university education and that it exceeded 3 yr. Nearly one half believed that apprenticeship was involved and one quarter believed that postgraduate experience in hospital was mandatory. Few acknowledged the wide breadth of training and a majority would consult a physician rather than a dentist regarding problems such as oral ulceration.

Adolescent↗
PubMed1994

Rhodopsin mutations in a Scottish retinitis pigmentosa population, including a novel splice site mutation in intron four.

Retinitis pigmentosa (RP) is the name given to a group of disorders, both clinically and genetically heterogeneous, that primarily affect the photoreceptor function of the eye. Mutations in the genes encoding for rhodopsin, RDS-peripherin, or the beta subunit of the cGMP phosphodiesterase enzyme can be responsible for the phenotype. In this study the rhodopsin gene has been screened for mutations in a panel of RP individuals and five different sequence changes have been detected to date in three dominantly inherited and two unclassified families. One of these, a base substitution in the 3'UTR, has not yet been confirmed as disease specific, while three missense substitutions have previously been reported and are likely to be responsible for the phenotype. The fifth change, a base substitution at the intron 4 acceptor splice site, represents a novel mutation and is assumed to be the causative mutation.

Base Sequence↗
PubMed1994

The immunolocalization of basic fibroblast growth factor in the mouse uterus during the initial stages of embryo implantation.

Mammalian embryo implantation involves a series of complex interactions between maternal and embryonic cells. Uterine polypeptide growth factors may play critical roles in these cell interactions. Basic fibroblast growth factor (basic FGF) is a member of a family of growth factors. This growth factor may be potentially important for the process of embryo implantation because it (a) is stored within the extracellular matrix and is thus easily available during embryo invasion, (b) is a potent modulator of cell proliferation and differentiation and (c) stimulates angiogenesis. The immunolocalization of basic FGF in the uterus during the peri-implantation period of pregnancy is presented in this study. Uterine tissue samples were obtained on days 6-9 of pregnancy with day 1 of pregnancy being the day of a vaginal copulatory plug. Uterine samples were fixed in Bouin's fluid for no longer than 18 h. Following fixation and paraffin embedding, sections were exposed to primary antisera made in rabbits against either (a) human recombinant basic FGF or (b) 1-24 synthetic fragment of bovine basic FGF. The primary antibody was followed by biotinylated goat anti-rabbit IgG and a biotin-avidin-peroxidase complex. There were no differences in the immunolocalization of basic FGF using either source of primary antibody. Our results demonstrated both temporal and spatial changes in the localization of immunoreactive basic FGF within the implantation chamber during days 6-9 of pregnancy. Inter-implantation sites resembled the non-pregnant uterus with basic FGF present in extracellular matrices including basal laminae. On day 6 of pregnancy, decidual cells within the primary decidual zone lacked both intracellular and pericellular basic FGF while non-decidualized uterine stroma resembled inter-implantation sites. By days 7-8 of pregnancy, the secondary decidual zone had formed and was characterized by the distinct pericellular localization of basic FGF around individual decidual cells. By day 9 of pregnancy, the mesometrial region was forming and contained cords of decidual cells and a labyrinth of maternal blood vessels. The decidual cells contained diffuse intracellular basic FGF. Trophoblast cells were devoid of basic FGF at all times examined. These results indicate that basic FGF is present within the implantation chamber on days 6-9 of pregnancy and may be involved in the decidual cell response, trophoblast cell invasion and angiogenesis.

Animals↗
PubMed1994

"Medicine on wheels": an opportunity for outreach and housestaff education.

Ambulatory-care teaching programs have been traditionally based in hospital settings. As many patients, in particular the homeless and underinsured, have never reached these settings, we describe a nontraditional outreach health-care program for medical residents. This multidisciplinary program places medical residents on a mobile van to deliver care to a population in New Haven where 18.2% of its families are below the poverty level and have limited or no access to health care at the teaching hospital. On-site urgent care is given along with HIV, pregnancy testing, and blood pressure screening. Health-care follow-up, dental care, alcohol detoxification, and drug counseling are scheduled. A total of 764 adult patients were seen between November 1991 and June 1993 by PGY2 residents on ambulatory rotations. One hundred forty-one patients consented to respond to a questionnaire. Thirty-seven (26%) were homeless with a mean length of homelessness of 15 months. Forty-one percent had been victimized within one year and 33% currently used illicit drugs. The benefits of this unique ambulatory teaching program for medical residents are described.

Adolescent↗
PubMed1993

Effects of percutaneous transluminal coronary angioplasty balloon compliance on angiographic and clinical outcomes.

The effect of balloon compliance on the safety and outcome of percutaneous transluminal coronary angioplasty (PTCA) is controversial. It has been proposed that PTCA balloons constructed from compliant polymers contribute to an increased risk of angiographic coronary dissection and potentially to adverse clinical results. To determine the effect of balloon material compliance on PTCA outcome, 1,076 PTCA procedures using balloons differing in compliance characteristics (polyethylene teraphthalate [noncompliant], polyethylene [intermediately compliant] or polyolefincopolymer [compliant]) were retrospectively analyzed. Baseline clinical, angiographic and procedural variables were similar among the 3 balloon material groups. In the noncompliant, intermediately compliant and compliant groups, the occurrence rates of intimal tears (10, 14 and 10%, respectively; p = NS for all comparisons) and coronary dissection (7, 9 and 8%, respectively; all p = NS) were also equivalent. The rates of acute occlusion, myocardial infarction, emergency bypass surgery and death were low and similar, and likewise unaffected by balloon material. The results provide evidence that the occurrence of adverse outcomes after PTCA is unrelated to balloon material compliance and support the clinical safety of balloons constructed of compliant or noncompliant polymers when used for appropriate coronary interventions.

Angioplasty, Balloon, Coronary↗
PubMed1993

Clinical value of determination of urokinase-type plasminogen activator antigen in plasma for detection of colorectal cancer: comparison with circulating tumor-associated antigens CA 19-9 and carcinoembryonic antigen.

We determined urokinase-type plasminogen activator antigen (u-PA), gastrointestinal cancer-associated antigen (CA 19-9), and carcinoembryonic antigen (CEA) in the plasma of patients with colorectal cancer at the time of clinical tumor detection and in a group of patients with Crohn's disease and analyzed the specificity of these tumor markers. u-PA, CA 19-9, and CEA were indicative for colorectal cancer in 75.5%, 51.5%, and 51.5% of tumor patients, respectively, with a specificity of 79.3%, 94%, and 97.5%. Sensitivity increased when two or all three markers were determined in identical blood samples, whereby a combination of u-PA and CEA exhibited the highest sensitivity value (90.9%) as compared to the combinations of u-PA and CA 19-9 or CA 19-9 and CEA. The use of all 3 markers did not lead to further increased sensitivity. False negative results were obtained in 3 of 32 cancer patients (9.1%, using one of 3 markers as indicative for malignant disease). These results indicate the benefit of multiparametric tumor marker analyses including u-PA antigen for the diagnosis of colorectal cancer.

Adult↗
PubMed1993

The effect of enterohemorrhagic Escherichia coli O157:H7 on intestinal structure and solute transport in rabbits.

BACKGROUND: The effect of enterohemorrhagic Escherichia coli O157:H7 infection on intestinal morphology and solute transport was examined. METHODS: New Zealand white rabbits, aged 10 days, were infected with E. coli strain EDL933 (O157:H7 containing the 60-megadalton plasmid-encoding adhesion factors VT1 and VT2) and compared with controls. Small and large intestinal histology and solute transport were studied 5 days after inoculation. Ion transport in the distal colon was also examined in animals infected with different strains encoding a combination of pathogenic factors. RESULTS: Infection with EDL933 induced diarrhea and mucosal disease in the colon, inhibited colonic Na+ absorption, and stimulated of Cl- secretion, but had no impact on the small intestine. Infection with strains A7785-C3A (O157:H7, plasmid-, VT1+, VT2+) and 85-170 (O157:H7, plasmid+, VT-) induced similar transport changes to EDL933. C600/1 (E. coli K-12, plasmid+, VT1+) decreased Na+ and Cl- absorption only. CONCLUSIONS: Abnormalities of colonic structure and ion transport could account for diarrhea production, but pathogenic factors other than the 60-megadalton plasmid-encoding adhesion factor and verotoxins appear to be involved in enterohemorrhagic E. coli infection.

Animals↗
PubMed1993

Morphometric and neurochemical changes in rat superior cervical ganglion during growth and adulthood.

We have previously found in rat superior cervical ganglion that there is a fall in neuron numbers and in cellular neuropeptide Y (NPY) immunoreactivity over the first year of life. In this study, we have used computerized image analysis to quantitate changes in neuron size, numbers and immunoreactivity for neuron-specific enolase (NSE), tyrosine hydroxylase (TH) and NPY in this ganglion between 1 and 85 weeks of age. Neuronal cytoplasmic area increased between 1 and 11 weeks and then remained stable until after 67 weeks, when there was a further increase in size of both NPY-positive and NPY-negative cells. Numbers of NPY-positive cells, but not those of NPY-negative cells, fell between 11 and 30 weeks. Both populations were stable after this time. Neuronal levels of NSE and TH remained constant, but levels of NPY fell between 58 and 67 weeks. These results indicate that changes in adult neuronal size, numbers and neurochemistry are independent phenomena. The increase in cell size and the fall in NPY after 58 weeks correspond to the time of withdrawal of some preganglionic inputs and may be responses to this event. By contrast, the decrease in NPY-positive cell numbers occurs some months before this time.

Aging↗
PubMed1993

Distribution and origin of aminergic neurones in dog small intestine.

In dog ileum, axons containing immunoreactivity for tyrosine hydroxylase (TH) and for DOPA decarboxylase (DDC) invest the neurones of the enteric ganglia and are present around arterioles, in the deep plexus of the circular muscle and in the laminar propria of the mucosal villi. Immunoreactivity for serotonin (5-HT) was present in mucosal enterochromaffin cells and in varicose axons investing cells of the submucous plexus, but not in axons in myenteric plexus, circular muscle or mucosa. No enteric neuronal cell bodies were immunoreactive for DDC or for 5-HT. Two weeks after extrinsic denervation of the ileum, all TH staining was absent. By contrast, the pattern of DDC staining was unchanged, except around blood vessels. We conclude that motility of dog ileum is likely to be regulated by sympathetic noradrenergic inputs and by intrinsic serotonergic and 'amine-handling' neurones. Dopaminergic innervation of dog ileum appears to be restricted to a sparse vasomotor supply.

Animals↗
PubMed1993

Predictors of postoperative respiratory complications in premature infants after inguinal herniorrhaphy.

There is a significant incidence of inguinal hernia in premature infants and the optimal timing of repair is controversial. A high rate of postoperative respiratory complications has been reported in this group. In this study, the records of 47 premature infants (mean gestational age, 30.3 weeks) who underwent herniorrhaphy while still in the neonatal intensive care unit were reviewed in an effort to define those conditions that are independent risk factors for complications. Forty-three percent of infants had complications, including postoperative assisted ventilation (34%), episodes of apnea and/or bradycardia (23%), emesis and cyanosis with first feeding (6%), and requirement for postoperative reintubation (4%). Although low gestational age and postconceptual age at operation, low birth weight for gestational age, and preoperative ventilatory assistance were significantly associated with postoperative complications, only a history of respiratory distress syndrome/bronchopulmonary dysplasia (odds ratio 2.3), a history of patent ductus arteriosus (odds ratio 2.5), and low absolute weight at operation (odds ratio 3.5 for 1,000-g decrease) were independent risk factors for postoperative complication. Despite previous reports citing postconceptual age as the factor having the greatest impact on postoperative complications, these results indicate that a history of respiratory dysfunction and size at operation may be more important predictors of postoperative respiratory dysfunction in preterm infants.

Age Factors↗
PubMed1993

Age-related changes in tyrosine hydroxylase and choline acetyltransferase in sympathetic ganglia of a rat strain with reduced sympathetic neuron numbers.

In Wistar rats, a subpopulation of sympathetic ganglionic neurons dies during ageing, but in the GH strain, these same neurons die during the period of perinatal maturation. We have compared tyrosine hydroxylase (TH) and choline acetyltransferase (ChAT) in superior cervical ganglia of GH and control rats at different ages. Ganglionic TH rose to near adult levels between postnatal weeks 1 and 2. No significant differences in TH values were seen between GH and control ganglia at any age, indicating that reduced neuron numbers are compensated for by increased cellular activity. Ganglionic ChAT rose initially in parallel with TH and then more slowly over postnatal weeks 3-4, reaching adult levels that were about 20% lower in GH than in normal ganglia. During ageing, TH remained constant but ChAT continued to rise slowly in GH ganglia, whereas ChAT in normal ganglia fell by about 10%. Both the strain difference in ChAT during development and the fall in ChAT during ageing in normal animals parallel the differences in ganglion cell numbers seen under these circumstances.

Aging↗