58 results on '"Barnhart JL"'
Search Results
2. Development and preliminary pharmacologic evaluation of a zwitterionic oral cholecystographic agent
- Author
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Barnhart Jl, Schulze Pe, Milos Sovak, Ranganathan R, Ulrich Speck, and Siefert Hm
- Subjects
Male ,Chemistry ,Iodobenzenes ,Contrast Media ,General Medicine ,Pharmacology ,Cholecystography ,Rats ,Bile flow ,Biliary excretion ,Mice ,Dogs ,Animals ,Bile ,Radiology, Nuclear Medicine and imaging ,ED50 - Abstract
A new zwitterionic iodinated molecule, 2-[3-(N-ethyl-2-hydroxyethyl) amino-acetamido-2, 4, 6-triiodobenzyl]-butyric acid (RCK-136) was synthesized, and its potential as an oral cholecystopaque was tested. In rats, 15 minutes following intravenous injection, RCK-136 reached maximum biliary concentration; 84% of the dose was excreted into bile. Biliary excretion of RCK-136 elicited a strong choleresis (44 ml of bile flow per mmol compound). Intravenous LD50 in rats averaged 390 mgI/kg. ED50 in rats, intradiencephalic, averaged 1.98 mgI/kg. The average densities of cholecystograms produced in three dogs with iosumetic acid and/or RCK-136 were comparable.
- Published
- 1981
3. Effect of theophylline of hepatic excretory function
- Author
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Barnhart, JL, primary and Combes, B, additional
- Published
- 1974
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- View/download PDF
4. Biliary excretion of dye in dogs infused with BSP or its glutathione conjugate
- Author
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Barnhart, JL, primary and Combes, B, additional
- Published
- 1976
- Full Text
- View/download PDF
5. Factors determining clearance of bilirubin in perfused rat liver
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Barnhart, JL, primary and Clarenburg, R, additional
- Published
- 1973
- Full Text
- View/download PDF
6. Interaction of serum albumin and bilirubin at low concentrations
- Author
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Clarenburg, R, primary and Barnhart, JL, additional
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- 1973
- Full Text
- View/download PDF
7. A feasibility study on quantitating myocardial perfusion with Albunex, an ultrasonic contrast agent.
- Author
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Wilson B, Shung KK, Hete B, Levene H, and Barnhart JL
- Subjects
- Animals, Dogs, Feasibility Studies, Injections, Intravenous, Albumins administration & dosage, Contrast Media, Coronary Circulation, Echocardiography
- Abstract
Quantitating regional myocardial perfusion has been the much sought-after but still elusive goal of many intensive investigations over the years. Videodensitometry of the variation of myocardial echogenicity in two-dimensional (2-D) echocardiograms as a function of time in conjunction with the injection of a bolus of an ultrasound contrast agent has been used clinically as a tool for a direct assessment of regional myocardial perfusion, despite that the precise relationship between tissue echogenicity observed on an image and the echoes detected by the ultrasonic probe is unknown. A study was undertaken to determine whether ultrasonic backscatter calculated from unprocessed radio frequency (RF) echoes returned from myocardium could be used to quantitate regional myocardium perfusion. A real-time ultrasonic scanner has been modified and interfaced to a microcomputer to acquire RF data at a rate up to 10 frames per second. Preliminary experimental data were obtained from four open-chest dogs following intracoronary injection of a bolus of Albunex and two dogs following intravenous injection with this modified scanner. On one hand, these results indicate that the integrated backscatter measured from the region of myocardium perfused by the coronary artery where Albunex is injected and selected for monitoring initially increases, reaches a peak, and then decreases as the contrast agent is washed out and that the magnitude of the peak is approximately linearly proportional to the volume concentration of Albunex microspheres injected, clearly demonstrating the feasibility of this approach for quantitating region myocardial perfusion. On the other hand, intravenous injections did not result in any appreciable change in myocardial backscatter in the left ventricle although a response could be observed in the left ventricular blood pool.
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- 1993
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8. Impact of HIV infection on mortality and accuracy of AIDS reporting on death certificates.
- Author
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Hessol NA, Buchbinder SP, Colbert D, Scheer S, Underwood R, Barnhart JL, O'Malley PM, Doll LS, and Lifson AR
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- Abstracting and Indexing standards, Adult, Aged, Community Health Centers, Follow-Up Studies, Humans, Life Tables, Male, Middle Aged, Population Surveillance, Registries, San Francisco epidemiology, Acquired Immunodeficiency Syndrome mortality, Bisexuality statistics & numerical data, Cause of Death, Death Certificates, HIV Infections mortality, HIV-1, Homosexuality statistics & numerical data
- Abstract
To assess the impact of HIV infection on mortality and the accuracy of AIDS reporting on death certificates, we analyzed data from 6704 homosexual and bisexual men in the San Francisco City Clinic cohort. Identification of AIDS cases and deaths in the cohort was determined through multiple sources, including the national AIDS surveillance registry and the National Death Index. Through 1990, 1518 deaths had been reported in the cohort and 1292 death certificates obtained. Of the 1292 death certificates, 1162 were for known AIDS cases, but 9% of the AIDS cases did not have HIV infection or AIDS noted on the death certificate. Only 0.7% of the decedents had AIDS listed as a cause of death and had not been reported to AIDS surveillance. AIDS and HIV infection was the leading cause of death in the cohort, with the highest proportionate mortality ratio (85%) and standardized mortality ratio (153 in 1987), and the largest number of years of potential life lost (32,008 years). The devastating impact of HIV infection on mortality is increasing and will require continued efforts to prevent and treat HIV infection.
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- 1992
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9. Hepatic transport of magnetic resonance imaging contrast agents. Ferrioxamine B derivatives.
- Author
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White DL, Eason RG, Alkire AL, Price DC, Hoener BA, Milco LA, Keen RE, and Barnhart JL
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- Animals, Biological Transport, Chromatography, High Pressure Liquid, Contrast Media analysis, Deferoxamine analysis, Ferric Compounds analysis, Iron Chelating Agents analysis, Contrast Media pharmacokinetics, Deferoxamine pharmacokinetics, Ferric Compounds pharmacokinetics, Iron Chelating Agents pharmacokinetics, Liver metabolism, Magnetic Resonance Imaging
- Published
- 1991
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10. Immunologic reactions of human recipients to repeated exposures to Albunex microspheres.
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Barnhart JL, Harada M, Lyle LR, and Saravis CA
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- Albumins administration & dosage, Albumins analysis, Antibodies blood, Drug Evaluation, Enzyme-Linked Immunosorbent Assay methods, Humans, Male, Microspheres, Skin Tests, Time Factors, Albumins immunology, Contrast Media administration & dosage, Contrast Media analysis
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- 1991
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11. Course of HIV-I infection in a cohort of homosexual and bisexual men: an 11 year follow up study.
- Author
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Rutherford GW, Lifson AR, Hessol NA, Darrow WW, O'Malley PM, Buchbinder SP, Barnhart JL, Bodecker TW, Cannon L, and Doll LS
- Subjects
- Follow-Up Studies, HIV Seropositivity, Humans, Male, Risk Factors, San Francisco epidemiology, Time Factors, Acquired Immunodeficiency Syndrome epidemiology, Bisexuality, HIV-1, Homosexuality
- Abstract
OBJECTIVE--To characterise the natural history of sexually transmitted HIV-I infection in homosexual and bisexual men. DESIGN--Cohort study. SETTING--San Francisco municipal sexually transmitted disease clinic. PATIENTS--Cohort included 6705 homosexual and bisexual men originally recruited from 1978 to 1980 for studies of sexually transmitted hepatitis B. This analysis is of 489 cohort members who were either HIV-I seropositive on entry into the cohort (n = 312) or seroconverted during the study period and had less than or equal to 24 months between the dates of their last seronegative and first seropositive specimens (n = 177). A subset of 442 of these men was examined in 1988 or 1989 or had been reported to have developed AIDS. MAIN OUTCOME MEASURES--Development of clinical signs and symptoms of HIV-I infection, including AIDS, AIDS related complex, asymptomatic generalised lymphadenopathy, and no signs or symptoms of infection. MEASUREMENTS AND MAIN RESULTS--Of the 422 men examined in 1988 or 1989 or reported as having AIDS, 341 had been infected from 1977 to 1980; 49% (167) of these men had died of AIDS, 10% (34) were alive with AIDS, 19% (65) had AIDS related complex, 3% (10) had asymptomatic generalised lymphadenopathy, and 19% (34) had no clinical signs or symptoms of HIV-I infection. Cumulative risk of AIDS by duration of HIV-I infection was analysed for all 489 men by the Kaplan-Meier method. Of these 489 men, 226 (46%) had been diagnosed as having AIDS. We estimated that 13% of cohort members will have developed AIDS within five years of seroconversion, 51% within 10 years, and 54% within 11.1 years. CONCLUSION--Our analysis confirming the importance of duration of infection to clinical state and the high risk of AIDS after infection underscores the importance of continuing efforts both to prevent transmission of HIV-I and to develop further treatments to slow or stall the progression of HIV-I infection to AIDS.
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- 1990
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12. Kaposi's sarcoma in a cohort of homosexual and bisexual men. Epidemiology and analysis for cofactors.
- Author
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Lifson AR, Darrow WW, Hessol NA, O'Malley PM, Barnhart JL, Jaffe HW, and Rutherford GW
- Subjects
- Acquired Immunodeficiency Syndrome complications, Acquired Immunodeficiency Syndrome diagnosis, Adult, Cohort Studies, Humans, Male, Reaction Time, San Francisco epidemiology, Sarcoma, Kaposi complications, Time Factors, Acquired Immunodeficiency Syndrome epidemiology, Bisexuality, Homosexuality, Sarcoma, Kaposi epidemiology
- Abstract
Acquired immunodeficiency syndrome (AIDS) surveillance data for both the United States and San Francisco indicate that Kaposi's sarcoma is more common in homosexual and bisexual men with AIDS than in other adults with AIDS, and that the proportion of newly diagnosed AIDS cases presenting with Kaposi's sarcoma has been significantly declining over time. The changing epidemiology of Kaposi's sarcoma was analyzed in a well-characterized cohort of homosexual and bisexual men; laboratory and interview data from a sample of these men were evaluated for determinants of and cofactors associated with Kaposi's sarcoma. Among 1,341 men with AIDS, the proportion presenting with Kaposi's sarcoma declined from 79% in 1981 to 25% in 1989. Compared with other men with AIDS, men with Kaposi's sarcoma had a shorter interval from human immunodeficiency virus (HIV) seroconversion to AIDS diagnosis (median, 77 vs. 86 months). Men with and without Kaposi's sarcoma did not significantly differ with respect to number of sexual partners, history of certain sexually transmitted or enteric diseases, use of certain recreational drugs (including nitrite inhalants), or participation in certain specific sexual practices. The decline in Kaposi's sarcoma may at least partly be due to a shorter latency period from infection to disease. Although cofactors for the development of Kaposi's sarcoma may exist, many previously hypothesized agents were not supported by this analysis.
- Published
- 1990
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13. Relationship between AIDS latency period and AIDS survival time in homosexual and bisexual men.
- Author
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Hessol NA, Byers RH, Lifson AR, O'Malley PM, Cannon L, Barnhart JL, Harrison JS, and Rutherford GW
- Subjects
- Acquired Immunodeficiency Syndrome complications, Acquired Immunodeficiency Syndrome epidemiology, Adolescent, Adult, Bisexuality, Cohort Studies, HIV Antibodies blood, Homosexuality, Humans, Male, Middle Aged, Proportional Hazards Models, Survival Analysis, Acquired Immunodeficiency Syndrome mortality, HIV Seropositivity epidemiology
- Abstract
We identified 277 homosexual and bisexual men diagnosed with acquired immune deficiency syndrome (AIDS) whose estimated human immunodeficiency virus (HIV) seroconversion dates, ranging from 1977-85, could be well approximated. These men were from a cohort of 6,705 homosexual and bisexual men originally recruited for studies of sexually transmitted hepatitis B in San Francisco in 1978-80. We compared the time from HIV seroconversion to the initial disease diagnostic of AIDS (AIDS latency period) with the time from first AIDS diagnosis to death (AIDS survival time) and found no significant overall correlation between latency period and survival time. Both Kaplan-Meier and Cox proportional hazard stepwise analyses found the initial AIDS diagnosis to be significantly associated with latency period, with individuals first diagnosed with Kaposi's sarcoma (KS) having a shorter latency but longer survival than those first diagnosed with Pneumocystis carinii pneumonia (PCP) or other AIDS diagnoses. Individuals with KS tended to be diagnosed earlier in the epidemic compared to those with PCP and other non-KS diagnoses. The AIDS survival time was significantly associated with the initial AIDS diagnosis but not with the estimated year of seroconversion, the year of first AIDS diagnosis, age at seroconversion, or racial/ethnic group. The information presented here on the relationship between the AIDS latency period and survival times suggests a model for the pathogenesis of HIV infection in which there is continual deterioration of the immune system. The wider use of antiviral and prophylactic therapies both preceding and following a diagnosis of AIDS may change this model as both latency and survival times are improved.
- Published
- 1990
14. Impact of AIDS on mortality in San Francisco, 1979-1986.
- Author
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Saunders LD, Rutherford GW, Lemp GF, and Barnhart JL
- Subjects
- Adult, Age Factors, Female, Humans, Male, Middle Aged, Racial Groups, Retrospective Studies, San Francisco epidemiology, Sex Factors, Acquired Immunodeficiency Syndrome mortality
- Abstract
We used death certificate data for San Francisco residents from 1979 to 1986 to calculate the number of deaths and years of potential life lost before age 65 (YPLL) for leading causes of death. Acquired immune deficiency syndrome (AIDS)-related deaths were defined as including cytomegalovirus infection (ICD-9 078.5); cryptococcal infection (ICD-9 117.5); Pneumocystis carinii pneumonia (ICD-9 136.3); other malignant neoplasms of the skin, site unspecified (ICD-9 173.9); deficiency of cell-mediated immunity (ICD-9 279.1); and unspecified immunity deficiency (ICD-9 279.3). These deaths increased from 5 (0.1% of all deaths) in 1979 to 534 (6.6%) in 1986. Of the 1,225 deaths caused by AIDS-related diseases during this period, 1,032 (84%) occurred in men aged 20-49 years. AIDS-related deaths increased between 1979 and 1986 from 0 to 44 (25% of all deaths), 0 to 257 (44%), and 0 to 150 (35%) in men aged 20-29 years, 30-39 years, and 40-49 years, respectively. In 1986, AIDS-related diseases were the third leading cause of deaths and the leading cause of YPLL among male San Francisco residents.
- Published
- 1990
15. The potential of iosulamide meglumine as a contrast material for intravenous cholangiography: an experimental study in dogs.
- Author
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Berk RN, Barnhart JL, Nazareno G, and Witt BL
- Subjects
- Animals, Diatrizoate Meglumine administration & dosage, Dogs, Injections, Intravenous, Iodipamide administration & dosage, Iodipamide metabolism, Cholangiography methods, Contrast Media administration & dosage, Diatrizoate analogs & derivatives, Diatrizoate Meglumine analogs & derivatives
- Abstract
Because of relatively low acute toxicity, iosulamide meglumine has been recommended as an improved contrast material for intravenous cholangiography. It has been postulated that high doses of the compound could be given safely with the expectation of achieving greater biliary excretion and improved opacification of the biliary tree. Experiments performed in dogs show that higher rates of infusion of iosulamide result in greater urinary elimination without additional biliary excretion. Consequently, iosulamide is unlikely to have any special advantage as a contrast agent.
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- 1981
- Full Text
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16. Isolation, hepatic distribution, and intestinal absorption of the glucuronide metabolite of iopanoic acid.
- Author
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Barnhart JL, Berk RN, Janes JO, and Witt BL
- Subjects
- Animals, Bile metabolism, Cytosol metabolism, Glucuronates administration & dosage, Glucuronates isolation & purification, Infusions, Parenteral, Intestinal Absorption, Iopanoic Acid administration & dosage, Kinetics, Liver ultrastructure, Rats, Taurocholic Acid administration & dosage, Taurocholic Acid metabolism, Glucuronates metabolism, Iopanoic Acid metabolism, Liver metabolism
- Published
- 1980
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17. The enhancement of iopanoate excretion by taurocholate.
- Author
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Berk RN, Barnhart JL, and Goldberger LE
- Subjects
- Animals, Bile metabolism, Dogs, Gallbladder Diseases diagnostic imaging, Gallbladder Diseases metabolism, Infusions, Parenteral, Kinetics, Liver Diseases diagnostic imaging, Liver Diseases metabolism, Radiography, Taurocholic Acid administration & dosage, Iopanoic Acid metabolism, Taurocholic Acid metabolism
- Published
- 1980
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18. Bile flow and electrolyte composition of bile associated with maximum bilirubin excretion in sheep.
- Author
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Barnhart JL and Upson DW
- Subjects
- Animals, Bile metabolism, Bile Acids and Salts metabolism, Bilirubin administration & dosage, Female, Infusions, Parenteral, Potassium metabolism, Rheology, Sodium metabolism, Taurocholic Acid pharmacology, Bile physiology, Bilirubin metabolism, Sheep physiology
- Abstract
Changes in the composition of bile accompanying the maximum biliary excretion (Emax) of bilirubin were investigated in sheep. Sheep fitted with chronic 'T-tubes' in the common bile duct were infused with taurocholate and bilirubin at various rates. Bile collected during both pre- and post-bilirubin steady-state periods was analyzed for the biliary concentration of electrolytes, bile salts, and bilirubin. Bilirubin Emax was 24.6 mumol/min while bile salt excretion during this period was 103 mumol/min. At Emax bilirubin entry into bile reached a concentration of 16.1 mumol/mL, increased the biliary concentration of sodium, did not change osmolarity of bile, and did not increase bile flow. The data suggest that bilirubin either interacts with mixed micelles in bile or forms molecular aggregates.
- Published
- 1979
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19. Choleresis associated with metabolism and biliary excretion of diethyl maleate in the rat and dog.
- Author
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Barnhart JL and Combes B
- Subjects
- Animals, Bile analysis, Bile metabolism, Bile Acids and Salts analysis, Dogs, Male, Maleates metabolism, Rats, Bile drug effects, Liver drug effects, Maleates pharmacology
- Abstract
Diethyl maleate (DEM) induces a choleresis in the rat and dog that appears to be canalicular in origin (bile flow and erythritol clearance increase equally) and occurs in the absence of an increase in bile salt excretion. Increased bile flow is probably accounted for by the osmotic activity of DEM compounds excreted into bile. These compounds represent the glutathione conjugate of DEM (DEM-GSH) and its subsequent metabolic products. Conjugation of DEM largely accounts for the depletion of hepatic GSH.
- Published
- 1978
20. The biliary and urinary excretion of iopanoic acid: pharmacokinetics, influence of bile salts, and choleretic effect. An experimental study in bile-fistula dogs.
- Author
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Berk RN, Loeb PM, Cobo-Frenkel A, and Barnhart JL
- Subjects
- Animals, Biliary Fistula metabolism, Dogs, Erythritol metabolism, Kinetics, Bile metabolism, Bile Acids and Salts pharmacology, Iopanoic Acid metabolism
- Abstract
The biliary and urinary excretion and the choleretic effect of iopanoic acid (Telepaque) were studied in nonanesthetized bile-fistula dogs using a stepwise increase of infusion rates of iopanoic acid and a constant infusion of sodium taurocholate at a rate of either 0.5 or 2.0 mumoles/min./kg. The maximum rate of bile excretion (0.671 mumoles/min./kg) when taurocholate was infused at the lower rate nearly doubled (1.325 mumoles/min./kg) when given at the higher rate. Maximum biliary concentrations of iopanoic acid at both rates of taurocholate infusion (70-77 mumoles/ml) were almost double the maximum concentration previously determined for iodipamide (Cholografin) (42 mumoles/ml).
- Published
- 1976
- Full Text
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21. Determinants of the rate of intestinal absorption of oral cholecystographic contrast agents in the dog jejunum.
- Author
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Janes JO, Dietschy JM, Berk RN, Loeb PM, and Barnhart JL
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- Animals, Dogs, Electrochemistry, Iodobenzenes metabolism, Iopanoic Acid metabolism, Ipodate metabolism, Permeability, Solubility, Tyropanoate metabolism, Cholecystography, Contrast Media metabolism, Intestinal Absorption, Jejunum metabolism
- Abstract
Successful opacification of the gallbladder during oral cholecystography depends on adequate absorption of the contrast agent from the intestine. The present studies were undertaken to define the specific characteristics of the intestinal mucosa and the properties of the various contrast agents which determine their rates of intestinal absorption. The polarity of the compounds was established by determining the ratios of their distribution between bulk solvents (benzene and water). In addition, the maximum aqueous solubility of each compound was determined. Using in vivo cannulated segments of dog jejunum, apparent passive permeability coefficients were measured. From these data, the apparent maximal rate of intestinal absorption was calculated. The six cholecystopaques studied differed markedly in polarity as judged by their varying ratios of distribution between benzene and water. The permeability coefficients varied inversely with the polarity of the compounds. However, the incremental changes in the coefficients were considerably less than the corresponding changes observed in the partition ratios. The rates of absorption of the more polar contrast agents (tyropanoate, iopronic acid, and iocetamic acid) were greater than the less polar compounds (iopanoic acid, sodium ipodate, and calcium ipodate) under the conditions in which the resistance of the unstirred water layer is not rate limiting and where bile acid micelles are not present.
- Published
- 1979
22. Influence of Mn(II) on NMR relaxation times of biological fluids.
- Author
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Barnhart JL, Berk RN, and Andre M
- Subjects
- Animals, Bile analysis, Dogs, Gallbladder, Humans, Liver, Magnetic Resonance Spectroscopy methods, Plasma analysis, Serum Albumin analysis, Body Fluids analysis
- Abstract
The extent that various concentrations of the paramagnetic metal ion manganese [Mn(II)] affect nuclear magnetic resonance (NMR) relaxation times was studied in vitro. Serial dilutions of Mn(II) were prepared in distilled water, 4% human serum albumin, dog plasma, dog gallbladder bile, and dog hepatic bile. T1 and T2 of each were measured at 10.7 M Hz using magnetization recovery and spin-echo radiofrequency sequences, respectively. The results show that relaxation rates (1/T1 and 1/T2) increase in a linear manner with increasing concentration of Mn(II) in all of the solutions tested. Mn(II) dissolved in dog gallbladder and hepatic bile, dog plasma, and 4% human serum albumin reduced relaxation times to a greater extent than Mn(II) in water. T1 times were reduced to a greater extent than T2 values. Thus, in T1 weighted magnetic resonance images, the NMR signal used to produce images would be more sensitive to the presence of Mn(II) in these biological fluids than in water. Furthermore, the magnitude of this in vivo effect of Mn(II) on NMR relaxation parameters depends not only on the concentration of this paramagnetic ion, but also on the constituents comprising the biological fluids (intra- and extracellular water, bile, plasma) and the nature of the chemical molecular interactions between these constituents and Mn(II).
- Published
- 1985
23. The biliary and urinary excretion and the choleretic effect of ioglycamide in dogs.
- Author
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Loeb PM, Berk RN, Cobo-Frenkel A, and Barnhart JL
- Subjects
- Animals, Dogs, Iodipamide metabolism, Triiodobenzoic Acids metabolism, Cholagogues and Choleretics, Cholangiography, Contrast Media, Iodobenzoates, Ioglycamic Acid metabolism
- Abstract
The biliary and urinary excretion and the choleretic effect of ioglycamide were studied in unanesthetized bile fistula dogs using stepwise increasing infusion rates to obtain multiple steady states. The results are compared with data from previously reported experiments in the same animals using iodoxamate and iodipamide. The rate of biliary excretion and the choleretic effect of ioglycamide are similar to those of iodipamide and iodoxamate. Like iodipamide and iodoxamate, the relation between infusion rate or plasma concentration and biliary excretion or concentration of ioglycamide are hyperbolic and can be fitted to saturation kinetics. Quantitatively, the excretion of ioglycamide and iodipamide are virtually identical. However, for any equimolar infusion rate or plasma concentration, more iodoxamate than ioglycamide is excreted in the bile. Despite the greater biliary excretion of iodoxamate, the maximum biliary concentration of ioglycamide, iodipamide, and iodoxamate is the same at low basal bile flow because the choleretic effects of the three compounds are equal. The data suggest that, theoretically, with any equimolar dose ioglycamide will be identical to iodipamide as a contrast material for intravenous cholangiography, but that iodoxamate may be superior to ioglycamide because more iodoxamate is excreted in the bile. This advantage of iodoxamate might become apparent clinically in patients with high basal bile flow or if smaller doses of the contrast material are used. However, at the presently recommended doses of the two compounds, it is unlikely that the use of ioglycamide for intravenous cholangiography will be any different than iodoxamate.
- Published
- 1976
- Full Text
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24. Biliary excretion of infused conjugated sulfobromophthalein in sheep heterozygote for the transport defect present in mutant Corriedale sheep.
- Author
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Barnhart JL, Gronwall RR, and Combes B
- Subjects
- Animals, Heterozygote, Male, Metabolism, Inborn Errors genetics, Metabolism, Inborn Errors metabolism, Mutation, Sheep genetics, Sheep Diseases metabolism, Biliary Tract metabolism, Metabolism, Inborn Errors veterinary, Sheep Diseases genetics, Sulfobromophthalein metabolism
- Abstract
Biliary excretion of dye was measured in 2 clinically normal and 2 heterozygote Corriedale sheep (the mutant Corriedale is characterized by depressed biliary transport of conjugated sulfobromophthalein (SBP) compounds) during infusion of the preformed glutathione conjugate of SBP. Maximal rates of excretion of conjugated SBP compounds in bile were comparable in heterozygote Corriedale and clinically normal sheep. These 2 heterozygote sheep do not express the biliary transport defect observed in mutant Corriedale sheep during SBP-glutathione infusion.
- Published
- 1983
25. Biliary excretion of sulfobromophthalein compounds in normal and mutant Corriedale sheep. Evidence for a disproportionate transport defect for conjugated sulfobromophthalein.
- Author
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Barnhart JL, Gronwall RR, and Combes B
- Subjects
- Animals, Bile Canaliculi metabolism, Biological Transport, Female, Glutathione metabolism, Kidney metabolism, Sheep genetics, Bile metabolism, Mutation, Sheep metabolism, Sulfobromophthalein metabolism
- Abstract
Biliary excretion of dye was evaluated in three normal and one mutant Corriedale sheep (characterized by depressed biliary transport of many organic anions) during infusion of unconjugated sulfobromophthalein (BSP) and its preformed glutathione conjugate (BSP-GSH). Maximal dye excretion rates in bile in normal sheep were higher when BSP-GSH rather than BSP was administered. In confirmation of earlier studies, dye excretion in bile was markedly depressed in the mutant animal. However, movement of unconjugated BSP from liver cells into bile remained relatively intact whereas transport of conjugated BSP compounds was virtually absent. Preservation of unconjugated dye entry into bile suggests the presence of a transport mechanism for unconjugated BSP which is preserved in mutant sheep and is distinct from that involved in BSP-GSH excretory transport. Renal clearance of conjugated BSP compounds was greater than of unconjugated BSP and clearance values were comparable in the normal and mutant sheep. Thus, no excretory defect comparable to that present in liver was identifiable in the kidney.
- Published
- 1981
- Full Text
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26. The epidemiology of AIDS-related Kaposi's sarcoma in San Francisco.
- Author
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Rutherford GW, Schwarcz SK, Lemp GF, Barnhart JL, Rauch KJ, Warner WL, Piland TH, and Werdegar D
- Subjects
- Humans, San Francisco, Sarcoma, Kaposi complications, Acquired Immunodeficiency Syndrome complications, Sarcoma, Kaposi epidemiology
- Published
- 1989
- Full Text
- View/download PDF
27. Characterization of SC2644-induced choleresis in the dog. Evidence for canalicular bicarbonate secretion.
- Author
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Barnhart JL and Combes B
- Subjects
- Animals, Benzoates pharmacology, Biliary Tract drug effects, Dogs, Electrolytes metabolism, Erythritol metabolism, Female, Male, Mannitol metabolism, Taurocholic Acid pharmacology, Bicarbonates metabolism, Biliary Tract metabolism, Cholagogues and Choleretics pharmacology, Propionates pharmacology
- Abstract
The biliary clearances of [14C]erythritol (Cery) and [3H]mannitol (Cmann) were measured simultaneously in dogs, first during choleresis induced by varying doses of sodium taurocholate and then by SC2644. Cery increased equally with the increases in bile flow induced by both compounds. Mannitol entry into bile, however, was partially restricted; deltaCmann/deltabile flow averaged 0.66 and 0.68 for taurocholate- and SC2644-induced flows, respectively. These findings suggest a common canalicular site of origin of the increased bile flow. Electrolyte composition was quite different in the increments, however. The bicarbonate concentration in the SC2644-induced increment of bile (65.8 microEq/ml) was three times higher than that associated with bile stimulated by taurocholate. SC2644- and taurocholate-induced biles were virtually isosmotic. These results in concert with other observations suggest a canalicular mechanism for bicarbonate entry into the biliary tree. Stimulation by SC2644 of ductal chloride bicarbonate exchange cannot be excluded, however.
- Published
- 1978
28. Biliary excretion of three cholecystographic contrast agents in dogs: iocetamic acid, iopronic acid and iosumetic acid.
- Author
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Barnhart JL, Berk RN, and Czuleger PC
- Subjects
- Animals, Bile Acids and Salts metabolism, Chromatography, High Pressure Liquid, Computers, Dogs, Iodobenzenes urine, Kinetics, Bile metabolism, Cholecystography, Contrast Media metabolism, Iodobenzenes metabolism
- Published
- 1979
- Full Text
- View/download PDF
29. Biodistribution of GdCl3 and Gd-DTPA and their influence on proton magnetic relaxation in rat tissues.
- Author
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Barnhart JL, Kuhnert N, Bakan DA, and Berk RN
- Subjects
- Animals, Gadolinium DTPA, Rats, Tissue Distribution, Contrast Media, Gadolinium metabolism, Magnetic Resonance Spectroscopy, Organometallic Compounds metabolism, Pentetic Acid metabolism
- Abstract
The biodistribution and relative molar effectiveness of the ionic (GdCl3) and chelated (Gd-DTPA) forms of gadolinium (Gd) to enhance proton relaxation rates in rat kidney, liver and spleen were evaluated. Rats were given intravenous injections of either GdCl3 (100 mumol/kg) or Gd-DTPA (178 mumol/kg). Gd-DTPA was primarily contained in the vascular compartment and was quickly accumulated in the kidney after injection with a relaxivity of 4.3 sec-1 (mumol/g kidney)-1. It was eliminated quickly from the body with only 2% of the injected dose remaining after 120 min. After GdCl3 injection, Gd was found primarily in liver and spleen. It accumulated continuously reaching 72% of the injected does in these two tissues after 120 min. Despite this continuous increase in tissue Gd concentration, the relaxation rates showed saturation in liver and spleen. The results suggest that after GdCl3 was injected it distributed either in a protein bound form that was effective at causing relaxation or in a colloid form that was not effective. The biodistribution of GdCl3 was such that it was determined by the phagocytic action of the recticuloendothelial system on a colloid. The biodistribution and tissue relaxivity of Gd-DTPA suggest it will be a useful vascular MRI contrast agent. However, the usefulness of GdCl3 as an MRI contrast agent is limited not only by its acute toxicity but also by its saturable effect on tissue relaxation rates. Consequently, GdCl3 has only a modest influence on tissue relaxivity.
- Published
- 1987
- Full Text
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30. The epidemiology of AIDS in Asian and Pacific Islander populations in San Francisco.
- Author
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Woo JM, Rutherford GW, Payne SF, Barnhart JL, and Lemp GF
- Subjects
- Acquired Immunodeficiency Syndrome transmission, Asia ethnology, Epidemiologic Methods, Ethnicity, Female, Homosexuality, Humans, Male, Pacific Islands ethnology, San Francisco, Substance-Related Disorders, Acquired Immunodeficiency Syndrome epidemiology
- Abstract
To evaluate the epidemiology of HIV infection in Asian and Pacific Islander populations in San Francisco, we compared cases of AIDS reported in Asians and Pacific Islanders with those reported in other racial and ethnic groups. The incidence of AIDS in Asians and Pacific Islanders was significantly lower than in Whites, Blacks, Latinos and American Indians and Alaska natives. AIDS cases among Asians and Pacific Islanders have increased 177% since 1985 compared with 54% in other racial and ethnic groups, with the greatest increase in homosexual and bisexual men and transfusion recipients. Among Asian and Pacific Islander ethnic groups, the incidence of AIDS was 168 cases per 100,000 in Polynesians, 141 per 100,000 in Japanese, 92 per 100,000 in 100 Filipinos, 72 per 100,000 in southeast Asians, and 21 per 100,000 in Chinese. We conclude that AIDS cases are disproportionately increasing in Asians and Pacific Islanders in San Francisco.
- Published
- 1988
- Full Text
- View/download PDF
31. Uptake of iopanoic acid by isolated rat hepatocytes in primary culture.
- Author
-
Barnhart JL, Witt BL, Hardison WG, and Berk RN
- Subjects
- Animals, Biological Transport drug effects, Cells, Cultured, Iodine Radioisotopes, Kinetics, Rats, Serum Albumin pharmacology, Iopanoic Acid metabolism, Liver metabolism
- Abstract
Uptake of iopanoic acid (IOP) was studied in 3-day primary cultures of rat hepatocytes isolated by the collagenase perfusion method. 125I activity of cells after incubation with 125I-IOP (1.0-100 microM) was used as a measure of uptake. At each IOP concentration uptake was linear for the first 45 s. The initial uptake velocity was directly proportional to IOP concentration and was nonsaturable up to 100 microM. The calculated uptake rate constant was 0.67 nmol . mg prot-1 . min-1 . microM-1. Uptake was only slightly reduced when the incubation was performed at 4 degrees C and was independent of sodium concentration. Albumin in the medium reduced IOP uptake. Uptake, however, was always greater than that predicted from the unbound IOP concentration alone. The data indicate that the hepatocyte uptake of IOP occurs by both a passive process and a saturable process. The saturable uptake component depends on an albumin-IOP-hepatocyte interaction. The influence of albumin on uptake occurs possibly by an undefined specific cell surface phenomenon of albumin that promotes uptake of IOP or by enhancement of the diffusibility of IOP across the unstirred layer.
- Published
- 1983
- Full Text
- View/download PDF
32. Erythritol and mannitol clearances with taurocholate and secretin-induced cholereses.
- Author
-
Barnhart JL and Combes B
- Subjects
- Animals, Bile drug effects, Dogs, Female, Male, Metabolic Clearance Rate drug effects, Stimulation, Chemical, Bile metabolism, Erythritol metabolism, Mannitol metabolism, Secretin pharmacology, Taurocholic Acid pharmacology
- Abstract
The biliary clearances of [14C]erythritol (Cery) and [3H]mannitol (Cmann) were measured simultaneously in dogs during cholereses induced by sodium taurocholate and by secretin. Cery increased equally with the increase in bile flow induced by taurocholate, whereas mannitol entry into bile was partially restricted; deltaCery/deltabile flow averaged 0.96; deltaCmann/deltaCery averaged 0.81. Values for erythritol clearance exceeded bile flow by a constant volume over a wide range of bile flows, a result that suggests distal reabsorption of a fixed amount of fluid, independent of canalicular bile production. During secretin-induced choleresis both Cery and Cmann accompanied 30-40% of the increase in bile flow, and the ratio of Cmann/Cery was 1.02. Thus the secretin-responsive region is permeable to both erythritol and mannitol. This affects the extent to which measured erythritol clearance accurately reflects canalicular bile formation; Cery may underestimate or overestimate canalicular bile flow. The electrolyte composition of bile remained relatively constant over a broad range of bile flows although the characteristics of taurocholate- and secretin-induced biles differed from each other. Taurocholate-stimulated bile was virtually isotonic. Secretin-induced bile had a high total concentration of electrolyte (mean concentration 367 meq/liter) rich in chloride and bicarbonate and was hypertonic.
- Published
- 1978
- Full Text
- View/download PDF
33. Dependence of the biliary excretion of iopanoic acid on bile salts.
- Author
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Loeb PM, Barnhart JL, and Berk RN
- Subjects
- Animals, Biliary Fistula metabolism, Chemical Phenomena, Chemistry, Dogs, Enterohepatic Circulation, Iopanoic Acid blood, Iopanoic Acid urine, Mathematics, Taurocholic Acid metabolism, Bile metabolism, Bile Acids and Salts metabolism, Iopanoic Acid metabolism
- Published
- 1978
34. Does glucagon enhance opacification of the bile ducts during intravenous cholangiography? An experimental study in dogs.
- Author
-
Berk RN, Barnhart JL, Nazareno GD, Brourman ND, and Flamm L
- Subjects
- Animals, Bile Acids and Salts metabolism, Dogs, Iodipamide, Cholangiography, Glucagon pharmacology
- Abstract
To determine the rational for the ability of glucagon to enhance opacification of the bile ducts during intravenous cholangiography, which has been claimed in recent clinical reports, experiments were performed in dogs which had had Thomas cannulas inserted. A constant step-wise infusion of iodipamide was administered with or without a bolus injection and constant infusion of glucagon. At every infusion rate of iodipamide the biliary concentration of the contrast agent was less when glucagon was administered. Glucagon caused a choleresis, but had no effect on the rate of excretion of iodipamide. It is concluded that the theory that glucagon is of value to improve opacification of the bile ducts during intravenous cholangiography is unlikely to be confirmed by further clinical trials.
- Published
- 1982
- Full Text
- View/download PDF
35. Development and preliminary pharmacologic evaluation of a zwitterionic oral cholecystographic agent.
- Author
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Sovak M, Barnhart JL, Ranganathan R, Schulze PE, Siefert HM, and Speck U
- Subjects
- Animals, Bile metabolism, Contrast Media toxicity, Dogs, Male, Mice, Rats, Cholecystography, Contrast Media metabolism, Iodobenzenes metabolism
- Abstract
A new zwitterionic iodinated molecule, 2-[3-(N-ethyl-2-hydroxyethyl) amino-acetamido-2, 4, 6-triiodobenzyl]-butyric acid (RCK-136) was synthesized, and its potential as an oral cholecystopaque was tested. In rats, 15 minutes following intravenous injection, RCK-136 reached maximum biliary concentration; 84% of the dose was excreted into bile. Biliary excretion of RCK-136 elicited a strong choleresis (44 ml of bile flow per mmol compound). Intravenous LD50 in rats averaged 390 mgI/kg. ED50 in rats, intradiencephalic, averaged 1.98 mgI/kg. The average densities of cholecystograms produced in three dogs with iosumetic acid and/or RCK-136 were comparable.
- Published
- 1981
- Full Text
- View/download PDF
36. Incidence of salmonellosis in patients with AIDS.
- Author
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Celum CL, Chaisson RE, Rutherford GW, Barnhart JL, and Echenberg DF
- Subjects
- Adolescent, Adult, Humans, Male, Middle Aged, Opportunistic Infections complications, Salmonella Infections complications, San Francisco, Sepsis complications, Sepsis epidemiology, Time Factors, Acquired Immunodeficiency Syndrome complications, Opportunistic Infections epidemiology, Salmonella Infections epidemiology
- Published
- 1987
- Full Text
- View/download PDF
37. Characteristics common to choleretic increments of bile induced by theophylline, glucagon and SQ-20009 in the dog.
- Author
-
Barnhart JL and Combes B
- Subjects
- Animals, Bile Acids and Salts metabolism, Dogs, Electrolytes metabolism, Erythritol metabolism, Liver drug effects, Metabolic Clearance Rate, Secretory Rate drug effects, Stimulation, Chemical, Bile metabolism, Cyclic AMP pharmacology, Etazolate pharmacology, Glucagon pharmacology, Liver metabolism, Nicotinic Acids pharmacology, Theophylline pharmacology
- Abstract
Theophylline, glucagon, and SQ-20009 induce a choleresis in the dog characterized by a proportionate increase in erythritol clearance and bile flow, no increase in bile salt excretion, and by an isosmotic solution of similar electrolyte composition. The increment in bile appears to originate at the canaliculus in response to increased cyclic-AMP.
- Published
- 1975
- Full Text
- View/download PDF
38. Iopanoate glucuronide: procedure for its iolation and purification and pharmacokinetics of its biliary excretion.
- Author
-
Barnhart JL, Parkhill BJ Jr, Cobo-Frenkel A, Berk RN, and Loeb PM
- Subjects
- Animals, Glucuronates metabolism, Iopanoic Acid isolation & purification, Liver metabolism, Male, Methods, Rats, Time Factors, Bile metabolism, Iopanoic Acid metabolism
- Published
- 1978
- Full Text
- View/download PDF
39. The biliary and urinary excretion of sodium tyropanoate and sodium ipodate in dogs: pharmacokinetics, influence of bile salts and choleretic effects with comparison to iopanoic acid.
- Author
-
Berk RN, Loeb PM, Cobo-Frenkel A, and Barnhart JL
- Subjects
- Animals, Bile metabolism, Cholagogues and Choleretics, Dogs, Taurocholic Acid pharmacology, Cholecystography, Contrast Media, Iodobenzenes metabolism, Iopanoic Acid metabolism, Ipodate metabolism, Tyropanoate metabolism
- Abstract
The biliary and urinary excretion of sodium tyropanoate (Bilopaque) and sodium ipodate (Oragrafin) were studied in unanesthetized bile-fistula dogs using stepwise, increasing, intravenous infusions of the contrast materials. A constant intravenous infusion of sodium taurocholate was administered at the rate of either 0.5 or 2.0 mu moles per min per kg throughout each experiment. The biliary excretion of sodium tyropanoate or sodium ipodate was not effected by the rate of sodium taurocholate infusion. The maximum rate of biliary excretion of sodium ipodate was significantly greater than that of sodium tyropanoate with the low taurocholate infusion, but there was no significant difference between the two with the high taurocholate infusion. With the low taurocholate infusion the maximum biliary excretion rate of sodium tyropanoate (0.956 mu moles per min per kg) and sodium ipodate (1.472 mu moles per min per kg) were significantly greater than the maximum biliary excretion of iopanoic acid (Telepaque) (0.671 mu moles per min per kg). With the high taurocholate infusion the maximum biliary excretion rates of the three contrast agents were not statistically different. Both sodium tyropanoate and sodium ipodate produced an increase in canalicular bile flow (8-11 ml per millimole). These data suggest that in clinical cholecystography sodium tyropanoate and sodium ipodate are not excreted in bile more rapidly than iopanoic acid, except when the rate of biliary excretion of bile salts is low; that is, except in patients who are fasting or those who are on a fat-free diet.
- Published
- 1977
- Full Text
- View/download PDF
40. Iotroxamide--a new intravenous cholangiographic agent. Comparison with iodipamide and the effect of bile salts.
- Author
-
Loeb PM, Barnhart JL, and Berk RN
- Subjects
- Animals, Bile metabolism, Bile Acids and Salts pharmacology, Biliary Fistula metabolism, Cholagogues and Choleretics metabolism, Dogs, Ioglycamic Acid metabolism, Kinetics, Models, Biological, Taurocholic Acid pharmacology, Triiodobenzoic Acids metabolism, Bile Acids and Salts metabolism, Cholangiography, Iodipamide analogs & derivatives, Iodipamide metabolism
- Abstract
The maximum biliary excretion rate of iotroxamide was found to be significantly greater than that of iodipamide in bile-fistula dogs. High bile salt excretion rates had no effect on the rate of biliary excretion of either compound, but the choleresis associated with greater bile salt excretion reduced the biliary concentration of both agents. Both are potent choleretics, stimulating about 23.5 ml of bile per mmole of contrast agent excreted in bile. This obligatory coupling of the contrast agents with water as they are excreted in bile imposes a limit on the maximum concentration that can be achieved in bile. Since iotroxamide is excreted more rapidly in bile than iodipamide for any equimolar plasma concentration, it may be a superior contrast agent for intravenous cholangiography.
- Published
- 1977
- Full Text
- View/download PDF
41. Effects of individual taurine-conjugated bile acids on biliary lipid secretion and sucrose clearance in the unanesthetized dog.
- Author
-
Gilmore IT, Barnhart JL, Hofmann AF, and Erlinger S
- Subjects
- Animals, Bile drug effects, Dogs, Kinetics, Taurine pharmacology, Bile metabolism, Bile Acids and Salts pharmacology, Cholesterol pharmacology, Phospholipids metabolism, Sucrose metabolism
- Abstract
The effect of three taurine-conjugated bile acids on bile flow, induced biliary secretion of phospholipids and cholesterol, and the hepatobiliary clearance from plasma of sucrose and erythritol (two uncharged, nonmetabolizable permeability probe molecules) was assessed in the unanesthetized bile fistula dog under steady-state conditions. Synthetically prepared chenodeoxycholyltaurine, cholytaurine, or urological rate for randomized 90-min periods, and four 10-min samples of bile were taken at the end of each period. Induced bile flow (per mumoles of bile acid) was calculated to be about one-third higher with ursodeoxycholyltaurine than with the other bile acids. Induced phospholipid secretion was identical for all bile acids, but cholesterol secretion differed: the two dihydroxy taurine conjugates induced considerably more cholesterol per molecule bile acid or phospholipid than colyltaurine. Further, ursodeoxycholyltaurine induced significantly more cholesterol secretion than chenodeoxycholyltaurine. Erythritol clearances were identical for all bile acids, and sucrose clearance, although slightly higher for chenodeoxycholyltaurine than ursodeoxycholyltaurine, was similar for all three conjugated bile acids. The results indicate that, for these two 3,7-dihydroxy bile acids, the orientation of the 7-hydroxyl group on the steroid nucleus has a marked influence on cholesterol secretion into bile and bile flow but not on the apparent permeability of the hepatobiliary tree.
- Published
- 1982
- Full Text
- View/download PDF
42. Changes in bile flow and composition induced by radiographic contrast materials.
- Author
-
Barnhart JL, Berk RN, and Combes B
- Subjects
- Animals, Bile drug effects, Bile Acids and Salts metabolism, Bile Canaliculi drug effects, Bile Canaliculi metabolism, Dogs, Liver drug effects, Triiodobenzoic Acids pharmacology, Bile metabolism, Contrast Media pharmacology, Liver metabolism
- Abstract
The hepatic excretion of radiographic contrast materials has a major impact on the composition and volume of bile. One obvious effect is the presence of the contrast agent in bile at a concentration that is determined by the rate of hepatic excretion, the rate of basal bile flow, and the rate of bile flow induced by the biliary excretion of the contrast agent. The magnitude of the choleretic response associated with the biliary transfer of contrast materials varies over a wide range. Iopanoic acid does not increase bile flow, whole RCK-136, an experimental contrast material that is similar to iopanoic acid chemically (both are triiodophenyl alkanoates), is a potent choleretic, generating 44 microliter of bile for each mumol excreted into bile. In distinction, the contrast materials in another chemical class, the dimers of triiodobenzoic acid, increase bile flow, but over a narrow range (20-25 microliter/mumol). The changes in bile flow and composition accompanying the administration of iodoxamate, one of the compounds of the dimer type, were compared to the choleresis induced by taurocholate. The additional bile flow was canalicular in origin in both instances, but the electrolyte composition of the bile was different. Bicarbonate concentration in the iodoxamate-induced increment of bile was nearly twice the concentration of bicarbonate in bile stimulated by taurocholate (52.3 and 25.3 mEq/1, respectively). This suggests a canalicular mechanism for iodoxamate-stimulated bicarbonate entry into the bile. The characteristics of bile induced by iodoxamate were also compared to bile associated with a variety of other choleretic agents, including diethyl maleate, DBcAMP, SC2644, and secretin. Only SC2644 stimulated canalicular bile flow with a high bicarbonate concentration similar to iodoxamate.
- Published
- 1980
- Full Text
- View/download PDF
43. Determination of parameters effecting proton relaxation of hepatic and gallbladder biles in dogs.
- Author
-
Bakan DA and Barnhart JL
- Subjects
- Animals, Bile physiology, Bile Acids and Salts analysis, Dogs, Gallbladder drug effects, Mucins pharmacology, Osmolar Concentration, Serum Albumin pharmacology, Sincalide pharmacology, Taurocholic Acid pharmacology, Viscosity, Bile metabolism, Gallbladder metabolism, Liver metabolism, Magnetic Resonance Imaging
- Abstract
The parameters which are important in causing changes in the T1 and T2 proton magnetic relaxation times of dogs bile were investigated. Three factors were found to be important in causing relaxation in bile: (i) total bile salt concentration; (ii) total protein concentration, and (iii) viscosity. The T1 and T2 values of hepatic and gallbladder biles were found to be independent of specific gravity, osmolarity and electrolyte concentrations. In vitro experiments were conducted with taurocholic acid, bovine serum albumin and porcine stomach mucin to examine the effects of intermolecular interactions on proton relaxation. Relative to each of the molecules alone, various combinations of the bile salt and proteins exhibit relaxation rates of 20 to 60% below theoretically expected values. This influence of in vitro molecular interactions on T1 and T2 is also likely to occur in hepatic and gallbladder biles in vivo. Thus, the effects of complex intermolecular interactions associated with the gallbladder microenvironment complicate but likely will not preclude direct assessment of physiologic data with magnetic resonance imaging.
- Published
- 1988
- Full Text
- View/download PDF
44. Saturation kinetics and choleretic effects of iodoxamate and iodipamide.
- Author
-
Berk RN, Loeb PM, Cobo-Frenkel A, and Barnhart JL
- Subjects
- Animals, Bile metabolism, Cholangiography, Dogs, Erythritol metabolism, Iodipamide blood, Iodipamide urine, Kinetics, Triiodobenzoic Acids blood, Triiodobenzoic Acids urine, Cholagogues and Choleretics, Iodipamide metabolism, Iodobenzoates metabolism, Triiodobenzoic Acids metabolism
- Abstract
The biliary excretion and choleretic effects of iodoxamate (Cholevue) and iodipamide (Cholografin) were compared in unanesthetized dogs with biliary fistulas in order to assess the potential of the two contrast agents for use in intravenous cholangiography. For any equimolar infusion rate, more iodoxamate was secreted in the bile than iodipamide was the same. At the constant basal bile flow maintained in these studies, there was no difference in the maximum biliary concentration of the two compounds. With the presently recommended doses, it is unlikely that iodoxamate will offer a striking improvement over iodipamide for intravenous cholangiography in patients with normal liver function.
- Published
- 1976
- Full Text
- View/download PDF
45. Uptake of iopanoic acid and its glucuronide conjugate by rat hepatocytes in primary culture.
- Author
-
Barnhart JL and Witt BL
- Subjects
- Adsorption, Animals, Cells, Cultured, Liver drug effects, Rats, Taurocholic Acid pharmacology, Iopanoic Acid analogs & derivatives, Iopanoic Acid metabolism, Liver metabolism
- Abstract
Uptake of iopanoic acid (IOP) and iopanoate glucuronide (IOP-G) was studied in 3-day primary cultures of rat hepatocytes isolated by the collagenase perfusion method. 125I activity of cells after incubation with 125I-IOP (10-100 microM) and 125I-IOP-G (10-100 microM) was used as a measure of uptake. At each concentration, uptake was linear for the first 45 sec. In the absence of albumin, the initial uptake velocity was directly proportional to the concentration or IOP or IOP-G and was nonsaturable up to 100 microM. The calculated uptake rate constants for IOP and for IOP-G were 0.059 and 0.048 nmole/(mg protein X min X microM), respectively. IOP uptake was not inhibited by sodium taurocholate nor by the contrast agents iodipamide, ipodate, and iopronic acid. The data indicate that the enhancement of IOP excretion by bile salts noted in vivo does not occur at the uptake step and that the hepatic uptake of both IOP and IOP-G in the absence of albumin is limited by diffusion.
- Published
- 1983
- Full Text
- View/download PDF
46. Biliary excretion of lopanoic acid in Gunn rats.
- Author
-
Barnhart JL, Witt BL, and Berk RN
- Subjects
- Animals, Bilirubin metabolism, Male, Rats, Rats, Gunn, Rats, Inbred Strains, Bile metabolism, Glucuronosyltransferase deficiency, Iopanoic Acid metabolism, Liver metabolism
- Published
- 1982
- Full Text
- View/download PDF
47. Influence of paramagnetic ions and pH on proton NMR relaxation of biologic fluids.
- Author
-
Barnhart JL and Berk RN
- Subjects
- Animals, Chlorides metabolism, Dogs, Humans, Hydrogen-Ion Concentration, Osmolar Concentration, Plasma metabolism, Protons, Serum Albumin metabolism, Water metabolism, Body Fluids metabolism, Image Enhancement, Magnetic Resonance Spectroscopy, Metals metabolism
- Abstract
The extent to which various concentrations of the paramagnetic metal ions [gadolinium (III), manganese (II), chromium (III), iron (III), nickel (II), copper (II), and cobalt (II)] affect proton magnetic relaxation times of distilled water, 4% human serum albumin (HSA), and dog plasma was studied in vitro. The pH of water and HSA varied from 4 to 8. Nuclear magnetic resonance relaxation parameters, T1 and T2, were measured at 10.7 MHz using inversion recovery and spin-echo radiofrequency sequences, respectively. The presence of Mn(II), Gd(III) and Cr(III) in water significantly reduced T1, while Fe(III), Ni(II), Cu(II) and Co(II) had only a minimal effect. In 4% HSA and dog plasma Mn(II) and Cu(II) had the greatest effect on T1. At neutral pH, Gd(III) and Cr(III) had little effect on T1, while Mn(II) induced a large shortening of T1. All of the metal ions changed T2 less than T1. These differences in proton relaxation enhancement caused by the various ions in the three solutions studied are due to variations in the effective magnetic moment, the degree of binding of the ions to protein, and the chemical form of the ion associated with changes in pH. Thus, it is impossible to predict the effect of metal ions on proton relaxation in vivo based solely on in vitro studies, because of the complexity of various biologic fluids in vivo.
- Published
- 1986
- Full Text
- View/download PDF
48. Iodipamide hepatotoxicity in the rat.
- Author
-
Burk RF and Barnhart JL
- Subjects
- Age Factors, Alanine Transaminase blood, Animals, Body Weight, Chemical and Drug Induced Liver Injury pathology, Dose-Response Relationship, Drug, Fasting, Iodipamide administration & dosage, Kidney drug effects, Liver drug effects, Liver pathology, Male, Methylcholanthrene administration & dosage, Necrosis, Phenobarbital administration & dosage, Premedication, Rats, Selenium deficiency, Chemical and Drug Induced Liver Injury etiology, Iodipamide toxicity
- Abstract
Iodipamide meglumine (Cholografin) has been implicated in several cases of liver injury in patients. The present study was designed to assess the hepatotoxic potential of this drug in rats. Iodipamide administered intraperitoneally or intravenously caused a characteristic type of necrosis which began in the midzonal area and spread to the centrilobular region. Only rats weighing 400 g or more developed necrosis when the dose administered was 2 mmol/kg. Rats weighing 200 g failed to develop liver necrosis even when given 3 mmol/kg. Selenium deficiency and pretreatment with 3-methylcholanthrene protected against liver necrosis due to iodipamide. Phenobarbital pretreatment provided little or no protection. Kidney tubular necrosis was also observed but occurred in young rats and in selenium-deficient rats which developed no liver necrosis. These results indicate that iodipamide is a hepatotoxin in rats. There are a number of factors, age being the most striking, that modify its hepatotoxicity.
- Published
- 1979
49. Use of hospitals by patients with AIDS in San Francisco.
- Author
-
Chen RT, Rutherford GW, Payne SF, Barnhart JL, Lemp GF, and Baskett LH
- Subjects
- Humans, Length of Stay, San Francisco, Acquired Immunodeficiency Syndrome therapy, Hospitals statistics & numerical data
- Published
- 1988
50. Apparent volume of the biliary tree in the dog.
- Author
-
Barnhart JL and Combes B
- Subjects
- Animals, Bile physiology, Dogs, Female, Liver anatomy & histology, Male, Organ Size, Taurocholic Acid, Time Factors, Biliary Tract anatomy & histology
- Abstract
The apparent volume of the biliary tree (ABV) in the dog was determined by measuring the mean biliary transit time of injected [14C]taurocholate ([14C]TC). After bolus injection of [14C]TC, entry of bile salt into the lumen of the biliary tree is signaled by an increase in bile flow. The volume of bile collected at the common duct from onset of choleresis until maximal concentration of 14C radioactivity is reached in bile minus the calculated quantity of bile that contains radioactivity and the cannula volume yields a value for the volume of the biliary tree present just prior to injection of [14C]TC. The mean value for ABV in 19 dogs was 2.49 +/- 0.65 microL/g liver (mean +/- SD).
- Published
- 1979
- Full Text
- View/download PDF
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