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Biomedical subjects

S E Johnson

Publications and source records attributed to S E Johnson.

At least 91 records · Page 5Linked to original sources
PubMed1983

Postprandial release of gastric inhibitory polypeptide (GIP) and pancreatic polypeptide in dogs with pancreatic acinar atrophy. Correction of blunted GIP response by addition of pancreatic enzymes to a meal.

In order to evaluate the enteropancreatic hormone axis in dogs with pancreatic acinar atrophy, we measured the release of gastric inhibitory polypeptide and pancreatic polypeptide in response to a standard meal and a meal containing pancreatic enzymes in affected dogs and controls. Postprandial release of pancreatic polypeptide was normal in dogs with pancreatic atrophy and was not affected by addition of pancreatic enzymes to the food. Gastric inhibitory polypeptide was not released after a standard meal in affected dogs, but this blunted response was corrected by the addition of pancreatic enzymes to the food. Feeding the enzyme alone did not stimulate a gastric inhibitory polypeptide response. These results, in part, support similar observations previously reported in children with exocrine pancreatic insufficiency associated with cystic fibrosis. We conclude that dogs with idiopathic pancreatic acinar atrophy can be used as an animal model for future study of enteropancreatic hormonal abnormalities that occur in human beings with exocrine pancreatic insufficiency.

Animals↗
PubMed1983

Anatomy and physiology of supernumerary cercal afferents in crickets: implications for pattern formation.

The afferent projection of supernumerary sensory neurons was examined in the cricket cercal sensory system. When a right cercus was exchanged for a left cercus the growth of supernumerary cerci was induced. The supernumerary cerci which formed tended to appear medial and/or lateral in a simple left leads to right exchange and were always right handed. Distal to the region where transplant and supernumerary meet, receptors on the supernumerary structure appear in a recognizable pattern typical of control cerci, and individual receptors homologous in position to control receptors could be identified. The supernumerary neurons associated with these identified receptors projected to the same area of neuropil as their homologs and thus uniquely identified neurons by all of the usual criteria were produced by the regeneration process. When the response properties of one postsynaptic neuron were examined it was shown that supernumerary afferents innervated it in a normal manner. The supernumerary neurons provide tests of various hypotheses for the assembly of ordered afferent projections. First, their axon trajectories are often atypical, but the terminal arbors grow into their proper areas in spite of this. Thus axon trajectory can be uncoupled from target area and is therefore unlikely to be a decisive factor in growth of the arbor. Second, supernumerary neurons are born later in development than their control homologs but their aroborizations are completely normal, adding to the existing evidence against a timing mechanism in the assembly of this afferent projection. Third, supernumerary neurons share target regions with their homologs, indicating a lack of competitive interactions. The most economical hypothesis to explain the precise mapping between the cercus and CNS holds that one step in the differentiation of insect sensory neurons is position dependent and that this step determines the choice of a target region within the CNS.

Afferent Pathways↗
PubMed1983

Transplantation of cricket sensory neurons to ectopic locations: arborizations and synaptic connections.

The cerci (abdominal sensory appendages) of crickets were transplanted to a leg stump after amputating the leg. Single identifiable cercal afferents were stained and found to regenerate into the host thoracic ganglia. A given neuron always arborizes in the same area of neuropil of the foreign ganglion and is distinctive in this property from other identified neurons. Taken as a whole, the results show that the afferents from the ectopic cercus are spatially ordered, the destination of a particular afferent within the ganglion being correlated with the location of its sensory cell body on the cercal surface. This is the case for the pro-, meso-, and metathoracic ganglion and the topography of these ectopic projections bears some resemblance to the normal projections found in the terminal ganglion. Thus the insect segmental ganglion seems to possess a set of markers which are interpretable by all afferent neurons, and this organization is repeated in each ganglion. The ectopic afferents make functional synaptic connections with intersegmental interneurons, one of which is described anatomically here. However, the ectopic afferents do not, as had previously been reported, make functional connections with the medial giant or lateral giant interneuron (the normal targets of cercal sensory neurons in the terminal ganglion).

Animals↗
PubMed1982

Legionella jordanis: a new species of Legionella isolated from water and sewage.

Legionella jordanis sp. nov., as found in two cultures, is described. One isolate was from river water in Indiana and the other isolate was from sewage in DeKalb County, Ga. The former is the type strain of the species, and is designated BL-540 (ATCC 33623). L. jordanis had a partial relationship to L. bozemanii by direct fluorescent-antibody tests but was unrelated to L. pneumophila, L. dumoffii, L. micdadei, L. gormanii, or L. longbeachae. Legionella phenotypic characteristics, including large amounts of branched-chain cellular fatty acids, were shown by the isolates. Studies of DNA relatedness showed that the two cultures of L. jordanis were only slightly related to the six previously described species of Legionella but were more than 90% related to each other. Indirect fluorescent-antibody tests with human sera suggested that unrecognized human infections with L. jordanis may be occurring.

DNA, Bacterial↗
PubMed1982

Bentiromide:xylose test in healthy cats.

The N-benzoyl-L-tyrosyl-p-aminobenzoic acid (bentiromide):xylose test for simultaneous evaluation of pancreatic exocrine function and intestinal absorptive function was studied in 8 clinically healthy cats. Plasma p-aminobenzoic acid (PABA) and xylose concentrations were determined before, and at 30, 60, 90, 120, 150, and 180 minutes after, a solution of bentiromide (1 g/100 ml) and D-xylose (10 g/100 ml) was given orally at a dosage of 5 ml/kg of body weight. The peak plasma concentrations for PABA occurred between 60 and 120 minutes, with highest mean value at 90 minutes (7.5 +/- 3.2 micrograms/ml), and for xylose between 30 and 120 minutes, with the highest mean value at 60 minutes (42.6 +/- 17.8 mg/dl). Large SD in plasma PABA and xylose concentrations indicated marked individual variation between healthy cats. It was concluded that (i) large variations between clinically healthy cats may limit the diagnostic usefulness of the bentiromide:xylose test in the cat, and (ii) guidelines for interpretation of plasma PABA and xylose concentrations reported previously for clinically healthy dogs could not be applied to cats because values were lower in cats.

4-Aminobenzoic Acid↗
PubMed1981

Experiments in the development of a continent ileostomy: a simplified technique without a reservoir in dogs.

A continent ileostomy without a reservoir was constructed in five dogs with minimal morbidity and mortality rates. The technique involved constructing a continent valve by retrograde intussusception of 8 cm of the terminal ileum, which was then exteriorized as an end ileostomy. The terminal ileum was emptied every 2 hours in the first week, 4 hours in the second week, 6 hours in the third week, and every 8 hours thereafter. This allowed it to gradually dilate and form its own natural reservoir. The follow-up period was 3 to 7 months. The animals remained fully continent to gas and feces. The reservoir capacity after 2 months was 600 cc. No pressure changes within the reservoir were observed with continuous infusion of saline solution.

Animals↗
PubMed1980

Proctosigmoidoscopic examinations by gastroenterology assistants.

Four gastroenterology assistants learned proctosigmoidoscopy by each performing 200 examinations with a physician. The assistants then examined a total of 7557 patients independently. The quality of their examination was assessed by reexamination of about every 10th patient by a physician. The data from all examinations were processed for computer tabulation and periodically reviewed. The patients accepted the examination by the gastroenterology assistant in all but three instances. The time spent by the patient for proctosigmoidoscopy, including preparation and examination, averaged 47 minutes before the assistant program and was reduced to an average of 34 minutes by the gastroenterology assistants. Ten patients had polyps (all smaller than 0.4 cm in diameter) undetected by the gastroenterology assistant but discovered by the physician. All 31 cancers and all of 371 polyps 0.5 cm or larger were discovered by the assistants. We conclude that a satisfactory proctosigmoidoscopy examination can be performed by a properly trained gastroenterology assistant, that it will conserve the physician's time, and that it reduces the waiting time of patients.

Gastroenterology↗
PubMed1979

Report of a clinical trial of a Canadian preparation of antihemophilic factor.

A clinical trial of a Canadian preparation of antihemophilic factor has been completed. The mean percentage increase in the factor VIII coagulant activity in the plasma was determined to be 2.1 +/- 0.8 per unit per kilogram dose, which compares very favourably with published data. The mean half-life of antihemophilic factor was found to be 14.7 hours. Side effects and reactions to the product were minimal and the product has been rated as clinically effective. No significant differences between lots were noted in the in vivo response or the half-life.

Adolescent↗
PubMed1979

Isolation of the Legionnaires' disease bacterium from environmental samples.

We analyzed 24 environmental samples collected in or near the Indiana Memorial Union, where an epidemic of Legionnaires' disease occurred in early 1978. We conducted fluorescent antibody analyses and culture on F-G and charcoal yeast extract agars of each sample directly; splenic tissue of guinea pigs inoculated with the sample; and yolk sacs from embryonated eggs inoculated with splenic tissue of guinea pigs injected with the sample. Legionnaires' disease (LD) bacterium was isolated from seven of the 24 samples: one water sample from the air-conditioner cooling tower of the Union; three water samples from a stream near the Union; and three mud samples from the same stream. The LD bacterium strains were of three different serotypes. These findings indicate that LD bacteria may be widespread in nature.

Air Conditioning↗
PubMed1976

Laboratory investigation and infection control of cholera in Kingston, Ont.

Vibrio cholerae, biotype El Tor, was isolated in a hospital laboratory in Kingston, Ont. in 1974. Confirmation and complete identification by the Ontario regional and provincial public health laboratories was obtained within 3 days. Institution of well established infection-control and public health measures prevented spread of the infection within the hospital and the community.

Adult↗