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Biomedical subjects

W J Dodds

Publications and source records attributed to W J Dodds.

At least 235 records · Page 13Linked to original sources
PubMed1981

Effect of histamine on motor function of opossum sphincter of Oddi.

In this study, we evaluated the effect of histamine on phasic contractile activity in the opossum sphincter of Oddi (SO). SO manometry was done in 35 animals, using an infused catheter system with minimal compliance. In anesthetized animals, phasic SO contractions occurred at a frequency of 7.3 +/- 0.3 (SE) contractions/min with an amplitude of 83 +/- 4 mmHg. Intravenous histamine (5-80 micrograms/kg) invariably inhibited the frequency and amplitude of SO phasic contractions. At larger doses, the SO contractions were abolished for several minutes. The SO inhibitory effect of histamine was duplicated by the selective H1-agonist, 2-pyridylethylamine, and abolished by H1-blockade with pyrilamine or neural blockade with tetrodotoxin. After tetrodotoxin, histamine and 2-pyridylethylamine caused an increased frequency and amplitude of SO contractions. This excitatory effect was blocked by pyrilamine. The histamine effects on SO phasic contractions were not altered by metiamide, atropine, phentolamine, propranolol, hexamethonium, or a large dose of nicotine. We conclude that 1) histamine depresses phasic SO contractions in the opossum; 2) histamine's depressant SO effect is mediated by H1 stimulation of noncholinergic, nonadrenergic SO inhibitory nerves, overriding an H1 stimulatory effect on SO smooth muscle; and 3) histamine has no H2-mediated effect on the opossum SO.

Ampulla of Vater↗
PubMed1981

Noncaseating granulomas of the pancreas. Probable sarcoidosis.

The patient presented with evidence of common bile duct obstruction and at surgery had narrowing of the distal common bile duct secondary to noncaseating granulomas of the pancreas, most probably sarcoidosis. Although pancreatic sarcoid is rare, this entity should be included in the differential diagnosis of pancreatic disease.

Cholestasis, Intrahepatic↗
PubMed1980

Rectal balloon catheters and the barium enema examination.

Inflation of a rectal balloon during the barium enema examination has the potential for obscuring rectal lesions or causing rectal injury. The purpose of this communication is to emphasize a rationale for the radiologist that minimizes the use of rectal balloons and reduces the risk of rectal injury when inflation of a rectal balloon is necessary.

Barium Sulfate↗
PubMed1980

A bleeding disease (von Willebrand's disease) in a Chesapeake Bay Retriever.

A bleeding disease similar to von Willebrand's disease in man was diagnosed in a 6-month-old Chesapeake Bay Retriever with recurrent, protracted gingival hemorrhage that responded rapidly to fresh, whole blood transfusions. The dog had a prolonged bleeding time and low plasma factor VIII coagulant activity (18%). The plasma had no detectable factor VIII-related antigen or von Willebrand factor, as measured by ristocetin-cofactor and polybrene-cofactor activities. The dam of the dog had a plasma factor VIII-related antigen concentration (32%) well below the normal range. The antigen in the sire's plasma was at the low end of the normal range, as was the polybrene-cofactor of both the sire and the dam. These data suggested an inherited basis for von Willebrand's disease in this dog.

Animals↗
PubMed1980

Mechanisms of gastroesophageal reflux in children.

We studied the lower esophageal sphincter in 29 children with known or suspected gastroesophageal reflux using a sleeve sensor and micro pH electrode. Mean lower esophageal sphincter pressure for a ten-minute monitoring period was 19 +/- 13 mm Hg; however, considerable temporal variation occurred in each child. Gastroesophageal reflex was infrequently associated with a low basal sphincter pressure (< 5 mm Hg) but usually associated with an increase in intra-abdominal pressure or with transient inappropriate relaxation of the lower esophageal sphincter.

Child, Preschool↗
PubMed1980

Sandifer syndrome: an unappreciated clinical entity.

Five cases of Sandifer syndrome are reported, and the authors suggest that frequently the diagnosis may be overlooked, especially when the patient has a milder or incomplete form of the syndrome. None of the children had hiatal hernia, so this is not an essential requirement for the syndrome. The findings in these five cases suggest that the abnormal posturing associated with this syndrome may be the result of extreme sensitivity of the esophagus to refluxed gastric acid.

Female↗
PubMed1980

The value of digital rectal examination before barium enema.

The authors recommend that the radiologist perform a digital examination of the rectum before barium enema. Rectal examination may disclose unsuspected lesions, facilitate tube insertion, indicate inadequate preparation of the colon, and aid in the decision of whether a rectal balloon is to be used.

Barium Sulfate↗
PubMed1980

Effect of cholecystokinin-octapeptide on opossum lower esophageal sphincter.

We evaluated the action of cholecystokini-octapeptide (CCK-OP) on lower esophageal sphincter (LES) pressure in the opossum. LES pressure was recorded by an infused sleeve device that straddled the sphincter, whereas intraluminal esophageal pressure and gastric pressure were recorded via conventional manometric catheters. Progressive intravenous pulse doses of CCK-OP caused 1) graded increases in LES pressure, 2) circular and longitudinal smooth muscle contraction in esophageal body, and 3) mild increases in intragastric pressure. Pressor effect of CCK-OP on the LES was weakly antagonized by tetrodotoxin (TTX), but not by atropine, phentolamine, or pyrilamine. TTX antagonism of CCK-OP appeared to be nonspecific because TTX also partially antagonized LES contractions induced by pentagastrin, substance P, and bethanechol. We conclude that CCK-OP at doses that cause LES relaxation in other species induces LES contraction in the opossum. This pressor effect appears to be elicited by a direct action of the hormone on LES smooth muscle.

Animals↗
PubMed1980

Mechanism of gastroesophageal reflux in recumbent asymptomatic human subjects.

We investigated the mechanism of gastroesophageal reflux (GER) in 10 health volunteer subjects. Continuous recordings of intraluminal esophageal pH and pressure were obtained on two consecutive nights from 6:00 p.m. to 6:30 a.m. in each subject. During each study, the subject remained recumbent, except to eat a standardized meal after 1 h of basal recording. A manometric assembly with seven recording lumens monitored: (a) lower esophageal sphincter (LES) pressure via a sleeve device 6.5 cm in length, (b) esophageal-body motor activity, (c) swallowing activity in the pharynx, and (d) gastric pressure. An electrode 5 cm above the LES recorded esophageal pH. Sleep was monitored by electroencephalogram. All subjects showed wide variations of basal LES pressure. GER was not related to low steady-state basal LES pressure, but rather occurred during transient 5-30 s episodes of inappropriate complete LES relaxation. The inappropriate LES relaxations were usually either spontaneous or immediately followed appropriate sphincter relaxation induced by swallowing. The majority of GER episodes occurred within the first 3 h after eating. During the night LES relaxation and GER occurred only during transient arousals from sleep or when the subjects were fully awake, but not during stable sleep. After GER the esophagus was generally cleared of refluxed acid by primary peristalsis and less frequently by secondary peristalsis. Nonperistaltic contractions were less effective than peristalsis for clearing acid from the esophagus. We conclude that in asymptomatic recumbent subjects GER is related to transient inappropriate LES relaxations rather than to low steady-state basal LES pressure and also, that primary perstalsis is the major mechanism that clears the esophagus of refluxed material.

Adult↗
PubMed1980

Criteria for selecting the animal to meet the research need.

Prior to designing any study which utilizes animals, a number of criteria should be considered. One should decide whether alternatives to intact animal usage (tissue culture systems or mathematical models) will provide acceptable results. Perhaps there is a naturally-occurring animal model which resembles the condition to be studied. Careful consideration should then be made to select the correct animal species, the genotypic, microbial status and numbers of such animals needed. Once the study has been completed, these animal-related factors should be considered when interpreting the data.

Animals↗
PubMed1980

Disseminated intravascular coagulation in experimentally induced feline infectious peritonitis.

Disseminated intravascular coagulation was induced in kittens by intraperitoneal inoculation of feline infectious peritonitis virus (FIPV). Kittens seronegative to FIPV survived significantly (P less than 0.05) longer than those seropositive to FIPV. Pyrexia, anemia, icterus, hyperbilirubinemia, and elevated concentrations of liver-specific enzymes were detected in the inoculated cats. Lesions induced included disseminated fibrinonecrotic and pyogranulomatous inflammation, hepatic necrosis, and widespread phlebitis and thrombosis. Localization of FIP viral antigen and immunoglobulin G was demonstrated in foci of heptic necrosis by immunofluorescence miroscopy. Lymphopenia, thrombocytopenia, hyperfibrinogenemia, and increased quantities of fibrin-fibrinogen degradation products were present in cats after the onset of clinical illness. Depression of factor VII, VIII, IX, X, XI, and XII plasma activities and prolongation of prothrombin and partial thromboplastin times also developed in infected cats. The accelerated onset of clinical disease and mortality in seropositive kittens vs seronegative kittens and the association of virus and antibody in multiple foci of hepatic necrosis suggest an immune-mediated component is involved in the pathogenesis of this disease.

Animals↗
PubMed1980

Measurement of canine von Willebrand factor using ristocetin and Polybrene. Diagnosis of canine von Willebrand's disease.

Dogs with VWD provide useful models for the study of the factor VIII complex. However, the study of canine VIIIR:WF has been hampered by the lack of a routine plasma assay for canine RCF, an activity that is usually used as a measure of VIIIR:WF. This study shows that canine plasma can be assayed for RCF with a macroscopic tilt-tube method using formalin-fixed human platelets, ristocetin, and extra canine albumin (5.0 mg/ml) to prevent plasma precipitation. An assay was also developed for canine plasma PBCF, an activity that is closely related to RCF. In 45 normal canine plasmas, VIII:C was not correlated with RCF, PBCF, or VIIIR:AG. However, RCF, PBCF, and VIIIR:AG were well correlated with each other. In 26 canine VWD plasmas, VIII:C was frequently normal, whereas VIIIR:AG, RCF, and PBCF were almost always deficient. The patterns of VIIIR:AG, RCF, and PBCF deficiencies in the canine VWD plasmas suggested that some canine breeds have a "classic" form of VWD whereas other breeds have "variant" forms of disease.

Animals↗
PubMed1980

Intraluminal pressure recording from the human sphincter of Oddi.

In this study we recorded intraluminal pressure from the human sphincter of Oddi during ERCP examination and determined the effect of enteric hormones on sphincter of Oddi motor function. Studies were obtained in 26 patients who had no demonstrable evidence of pancreaticobiliary disease. After cannulation of the common bile duct (CBD) or pancreatic duct (PD), pressure measurements were made across the sphincter of Oddi (SO) during 1-2 mm incremental withdrawals of the catheter pausing 1 min or longer at each station. The findings showed an SO segment, 4-6 mm in length, that had basal, steady-state pressure about 4 mm Hg higher than CBD or PD pressure. Pronounced phasic contractions were superimposed on the basal SO pressure. These phasic contractions measured 101 +/- 50 SE mm Hg in amplitude and 4.3 +/- 1.5 sec in duration. They had a frequency of 4.1 +/- 0.9/min. Corresponding phasic contractions were not observed in the CBD, PD, or duodenum. Intravenous pulse doses of cholecystokinin octapeptide and glucagon depressed SO motor activity, whereas pentagastrin increased SO pressure. Secretin caused a mixed response of excitation followed by inhibition. We conclude that the human sphincter of Oddi demonstrates unique phasic contractions that are altered by enteric hormones given intravenously. These phasic SO contractions may have an important role in regulating biliary and pancreatic duct employing.

Adult↗