Search PubMed⌕ Search

Biomedical subjects

B Allen

Publications and source records attributed to B Allen.

At least 127 records · Page 7Linked to original sources
PubMed1984

Variations in concentrating function of the gallbladder in the conscious monkey.

Hepatic bile is concentrated in the gallbladder by absorption of water and electrolytes. The rate of water absorption can be influenced in vitro and in vivo by gastrointestinal hormones and neurogenic transmitters. Recent studies have demonstrated that besides its absorbing activity, the gallbladder has the ability to secrete fluid into its lumen. In the present experiments, we studied the rate of net water absorption in the gallbladders of pig-tailed monkeys sitting in restraining chairs. Bile from the common bile duct and the gallbladder was led out through cannulas to a stream splitter, samples were obtained, and bile was returned to the duodenum. By measuring outflow from the gallbladder and the concentration of bile acids in hepatic bile and bile that had passed through the gallbladder, net water absorption from the gallbladder bile could be calculated. The results demonstrate that during daytime fasting there was a net absorption corresponding to 30% of the fasting gallbladder volume per hour, and after feeding there was a net secretion of fluid into the gallbladder lumen. Compared with the awake fasting state, net water absorption from the gallbladder decreased at night while the animal was fasting and asleep. Physiologically, secretion of fluid after a meal could help to empty the gallbladder, and changes in net water absorption by the gallbladder could influence the kinetics of the enterohepatic circulation of bile acids.

Absorption↗
PubMed1983

A field trial, of preshipment vaccination, with intranasal infectious bovine rhinotracheitis-parainfluenza-3 vaccines.

A total of 849 calves, 278 controls, 335 vaccinated intranasally with IBR-PI3/TS and 236 vaccinated intranasally with IBR-PI3/PTC were studied in a field trial of preimmunization. All calves were vaccinated in Saskatchewan at least three weeks prior to shipment to feedlots. Four hundred and twenty six calves were not sold within eight weeks of vaccination; however, seven of these died within four weeks of vaccination. Treatment rates varied from 1.0% to 5.2%. There was no significant effect of vaccination on treatment rates. Similarly, there was no significant effect of vaccination in the 74 calves sold to feedlots in Saskatchewan. Three hundred and forty nine calves were sold to feedlots in Ontario. Two of these died from fibrinous pneumonia. Treatment rates varied from 1.7% to 33.3% in different feedlots, but there was no significant effect of vaccination on treatment rates. Therefore, preimmunization is unlikely to significantly reduce the overall treatment rate in calves entering feedlots.

Animals↗
PubMed1982

Sequential 2-acetylaminofluorene--phenobarbital exposure induces a cytosolic aldehyde dehydrogenase during rat hepatocarcinogenesis.

A significant change in hepatic aldehyde dehydrogenase activity has been observed in normal Sprague-Dawley rat liver during the promotion phase of hepatocarcinogenesis induced by brief feeding of 2-acetylaminofluorene (2-AAF) followed by tumor promotion using dietary phenobarbital (PB) exposure. Animals receiving only 2-AAF or PB do not possess this new aldehyde dehydrogenase activity. The phenotype is characterized by the appearance of a new cytosolic isozyme kinetically, electrophoretically and immunochemically distinct from the normal liver aldehyde dehydrogenase isozymes and from aldehyde dehydrogenases inducible in 2-AAF-induced hepatomas. The new isozyme is NAD-dependent, disulfiram-sensitive and cross-reacts with antiserum to a normal liver aldehyde dehydrogenase inducible in several lines of rats by PB. However, the population of animals used in this study has been shown previously to be non-responsive to aldehyde dehydrogenase induction by dietary PB. Since no animals receiving only PB express this new isozyme, the carcinogen must play a significant role in its induction. Moreover, that not all animals receiving carcinogen and promoter possess the phenotype suggests this carcinogen/promoter interaction has a genetic basis.

2-Acetylaminofluorene↗
PubMed1981

Ultrastructural analysis of medial brain stem afferents to the superficial dorsal horn.

Axonal projections of medial brain stem areas rich in serotonin-containing neurons were identified in layers I and II of cat medullary dorsal horn using EM autoradiography. Following [3H]amino acid injections into the brain stem, labeled axonal endings were found throughout layers I and II but were most numerous in layer I. Three different morphological types of endings could be distinguished. Each type resembled serotonergic axonal endings identified in previous experiments. The labeled endings formed both symmetrical and asymmetrical synapses on dendritic shafts and spines and occasionally on a neuronal soma suggesting that the major site of action of the descending serotonergic afferents is on the neurons in layers I and II.

Afferent Pathways↗
PubMed1981

Sludge is calcium bilirubinate associated with bile stasis.

Biliary sludge is a frequent finding on abdominal sonography. It is most often found after prolonged stasis of gallbladder bile associated with other illness or mechanical obstruction of the common duct, and seldom indicates primary gallbladder disease. In most cases, sludge is a suspension of pigment precipitates in bile, and is at least in part calcium bilirubinate. Sludge may disappear with the return of normal gallbladder contractility. The ease with which this precipitate forms during stasis of gallbladder bile suggests a role for this process in the pathogenesis of cholelithiasis.

Bile↗
PubMed1981

Management of recurrent and residual common duct stones.

When operating on patients with postcholecystectomy choledocholithiasis, a drainage procedure should be performed for the following indications: (1) multiple stones in the duct, (2) history of choledocholithotomy, (3) marked dilatation of the duct, (4) inability to remove all stones, and (5) presence of a ductal stricture. Patients with none of these are adequately treated by choledocholithotomy alone. Because endoscopic sphincterotomy has been shown to be safe and effective, however, it is currently our preferred method of treatment for the average patient with this condition.

Adult↗
PubMed1981

Ultrastructure of descending serotoninergic axonal endings in layers I and II of the dorsal horn.

Serotoninergic axonal endings in layers I and II of the medullary and spinal dorsal horn of the cat were ultrastructurally characterized following uptake of [3H]serotonin. The two most common types were dome-shaped endings which could be distinguished by the size and shape of their agranular synaptic vesicles. The two types of endings were found throughout layers I and II, but were most numerous in layer I. The labeled endings formed both symmetrical and asymmetrical synapses on dendritic shafts and spines, and occasionally a symmetrical synapse on a neuronal soma. Using the technique of anterograde transport of [3H]amino acid, two morphologically identical types of endings were demonstrated as originating from neurons in the caudal raphe nuclei and adjacent reticular formation.

Afferent Pathways↗
PubMed1980

In vitro investigation of the origin of echoes with biliary sludge.

To investigate the origin of echoes from "biliary sludge," concentrated bile and bile from 5 patients with ultrasound findings of biliary sludge were examined in a tissue-equivalent phantom before and after filtration through progressively smaller pore sizes. Filtration converted echogenic bile to echo-free bile. Examination of the filtration residue by light microscopy established that the source of echoes in biliary sludge was particles, predominantly pigment granules, with lesser amounts of cholesterol crystals. Partial chemical characterization by determination of vulnerability to different solvents verified that the sludge was mainly calcium bilirubinate.

Bile↗
PubMed1977

Evaluation of radiation therapy for bone metastases: pain relief and quality of life.

The records of 158 patients irradiated for bone metastases were reviewed to evaluate the effectiveness of pain relief and to judge the effect of treatment on overall quality of life. Within 3 months 73% of the sites treated had pain relief, with 55%-65% having sustained relief up to 1 year or death. Of patients surviving more than 3 months, 63% maintained a satisfactory quality of life and were able to take care of most personal needs. The median survival of all patients was 1 year from initial treatment for bone metastasis. Radiation dose and the primary tumor site do not seem to be significant prognostic factors for initial pain relief or quality of life.

Bone Neoplasms↗