Search PubMed⌕ Search

Biomedical subjects

T Gilat

Publications and source records attributed to T Gilat.

At least 127 records · Page 7Linked to original sources

Contribution of vesicular and micellar carriers to cholesterol transport in human bile.

A nonmicellar, bile salt-independent mode of cholesterol transport in human bile involving phospholipid vesicles was recently reported by our group. In the present study, we have investigated the relative contribution of the phospholipid vesicles and mixed bile salt-phospholipid micelles to cholesterol transport in human hepatic and gallbladder biles. The vesicles (ca 800 A diameter) were demonstrated by quasi-elastic light scattering (QELS) in fresh bile and after chromatography. Gel filtration under conditions that preserved micellar integrity demonstrated that biliary cholesterol was associated with both vesicles and micelles. At low bile salt concentration, the vesicular phase was predominant and most of the cholesterol was transported by it. With increasing bile salt concentrations, a progressive solubilization of the vesicles occurred with a concomitant increase in the amount of cholesterol transported by micelles. The vesicular carrier may be of particular biological significance for cholesterol solubilization in supersaturated biles.

Bile↗

A non-micellar mode of cholesterol transport in human bile.

Quasi-elastic light scattering (QELS) was used to measure particle size in fresh human hepatic bile of 14 subjects. Particles with an approximate diameter of 700 A were found in all biles. The particles were almost unchanged after the bile salt concentration was reduced to 0.06 mM by dilution or dialysis against 150 mM NaCl. During dialysis bile salts were removed, while cholesterol and phospholipids remained in solution apparently in the large particles-vesicles. These experiments suggest the presence of a novel, bile salt-independent, mode of cholesterol transport in saturated human bile.

Bile↗

Should we worry about animal growth promoters?

Estrogens and compounds with estrogenic activity have been used for many years as animal growth promoters and to synchronize estrus in cows. The resorcylic acid lactones (RALS), which include zearalenone, are being used increasingly for these purposes. These estrogenic mycotoxins, now produced commercially, have teratogenic, mutagenic, and carcinogenic properties. There is some evidence that their residues could remain in certain organs at the time the animal products come to market, and this may be of medical significance.

Animal Husbandry↗

An increased familial frequency of gallstones.

Despite the very high prevalence of gallstone disease, studies of familial factors are very few, and asymptomatic family members were not studied. We studied, in a prospective manner, the frequency of gallstones in 171 first-degree relatives of patients with proven gallstones compared with 200 matched controls. All subjects were studied by oral cholecystography, and their height, weight, blood glucose, cholesterol, and other parameters were measured. Gallstones were found in 20.5% of the family group and in 9.0% of the control group. Gallstones were found in 22.8% of the female and 16.7% of the male family members as opposed to 10.3% of the female and 8.0% of the male controls. All these differences were statistically significant. Known risk factors, such as Ashkenazi community group, higher age, and overweight, were more frequent in the control group, as were blood glucose and cholesterol. These findings strengthen the validity of the twofold higher frequency of gallstones found in the family group and are likely to be due to genetic factors. A formal genetic family study of gallstone disease is now indicated, using the ultrasonic method.

Adult↗

The causes of hypoxemia in elderly patients during endoscopy.

Changes in arterial gas tensions were determined in 114 patients undergoing elective gastrointestinal endoscopic examinations with standard or pediatric gastroscopes or colonoscopes. All patients were premedicated intravenously with 0.5 mg of atropine and 10 mg of diazepam. In addition, two thirds received a narcotic, either 50 mg of meperidine or 0.05 mg of the short acting drug fentanyl. The choice of instrument or premedication was usually sequential. There was significant depression of the arterial oxygen tension (Pao2), of 17.4%, immediately following premedication that included a narcotic but not with diazepam alone. Significant reduction of the Pao2 persisted during upper endoscopy if a standard gastroscope was used and meperidine or fentanyl was included in the premedication. If a narrow diameter gastroscope was employed, only meperidine was associated with persistent depression of the Pao2. To minimize hypoxia in elderly patients during upper endoscopy, no narcotic or only a short acting one should be included in their premedication, and a narrow diameter instrument should be used for the examination.

Aged↗

Radionuclide confirmation of the therapeutic value of isosorbide dinitrate in relieving the dysphagia in achalasia.

In fifteen patients with achalasia, we measured lower esophageal sphincter pressures before and after 5 mg of sublingual isosorbide dinitrate. The mean pressure fell significantly, from 36.5 to 18.4 mm Hg (P less than 0.01). The effectiveness of this therapy was confirmed by gamma camera measurement of the esophageal emptying time of a radionuclide test meal which was significantly less after the medication (P less 0.05). The emptying time was invariably longer than 10 minutes before therapy, and in 12 of the 15 patients decreased after therapy to 1-8 minutes, corresponding to the clinical response to the drug therapy. The noninvasive radionuclide technique provides a simple way of assessing the results of drug therapy in achalasia.

Adolescent↗

99mTc-HIDA cholescintigraphy in Dubin-Johnson and Rotor syndromes.

99mTc-HIDA cholescintigraphy was performed in 6 patients with Dubin-Johnson syndrome and 1 patient with Rotor syndrome. In the patients with Dubin-Johnson syndrome, the cholescintigrams had a characteristic pattern of delayed visualization or nonvisualization of the gallbladder and bile ducts in the presence of intense, homogeneous, and prolonged visualization of the liver. In the patient with Rotor syndrome, the hepatobiliary system was not visualized at all. It is concluded that 99mTc-HIDA cholescintigraphy may be helpful in the diagnosis of Dubin-Johnson syndrome and Rotor syndrome and in the differential diagnosis between these two conditions.

Diagnosis, Differential↗

Dynamic, diagnostic, and pharmacological radionuclide studies of the esophagus in achalasia.

The esophagus was evaluated in 15 patients with achalasia by continuous gamma camera imaging following ingestion of a semi-solid meal labeled with 99mTc. The images were displayed and recorded on a simple computerized data processing/display system. Subsequent ciné mode images of esophageal emptying demonstrated abnormalities of the body of the esophagus not reflected by the manometric examination. Computer-generated time-activity curves representing specific regions of interest were better than manometry in evaluating the results of myotomy, dilatation, and drug therapy. Isosorbide dinitrate significantly improved esophageal emptying.

Adolescent↗

Isosorbide dinitrate and nifedipine treatment of achalasia: a clinical, manometric and radionuclide evaluation.

The effects of sublingual isosorbide dinitrate (5 mg) and nifedipine (20 mg) were compared in 15 patients with achalasia. The parameters examined included the manometric measurement of the lower esophageal sphincter pressure, the radionuclide assessment of esophageal emptying and the clinical response. The mean basal lower esophageal sphincter pressure fell significantly after both drugs (p less than 0.01), with a maximum fall of 63.5% 10 min after receiving isosorbide dinitrate, but by only 46.7% 30 min after nifedipine. The esophageal radionuclide test meal retention was significantly less (p less than 0.01) only after receiving isosorbide dinitrate. The drug improved initial esophageal emptying by its effect on the lower esophageal sphincter and by relieving the test meal hold-up noted to occur at the junction of the upper and midesophagus. Eight patients cleared their test meal within 10 min after isosorbide dinitrate administration while only two did so after nifedipine. Subjectively, 13 patients had their dysphagia relieved by isosorbide dinitrate and 8 by nifedipine. However, this relief was not confirmed in 4 patients by the radionuclide study and they, as well as the other 3 patients who did not respond to therapy, were referred to pneumatic dilatation. Side effects were more prominent after nitrates. Three of the patients are currently receiving nifedipine and 5 patients received isosorbide dinitrate therapy for 8-14 mo. The radionuclide test meal is currently the best way of objectively evaluating drug therapy in patients with achalasia. Isosorbide dinitrate is more effective than nifedipine in relieving their symptoms.

Adolescent↗

Impairment of bromosulfophthalein clearance by bile salt administration in normal volunteers and patients with Dubin-Johnson syndrome.

Sodium dehydrocholate administration significantly impaired bromosulfophthalein (BSP) clearance in six normal volunteers, despite its choleretic effect. In order to determine whether the impairment is at the stage of excretion of BSP from the liver cell into the bile, patients with Dubin-Johnson syndrome were studied. In all six Dubin-Johnson patients, sodium dehydrocholate administration significantly decreased BSP clearance. Since serum bile acid levels are normal in Dubin-Johnson patients, presumably due to a final secretory pathway into the bile distinct from that of BSP and other organic anions, the interaction between BSP and bile acids cannot take place at the stage of excretion into the bile. Based on a previous study and our results, the interaction between BSP and bile salts seems to occur at the site of transport within the liver cell. This mechanism of inhibition may be responsible for the increased serum BSP retention during chemotherapy.

Adult↗

Serum zinc and taste acuity in Tel-Aviv patients with inflammatory bowel disease.

Serum zinc levels and taste acuity were determined in patients with Crohn's disease, those with ulcerative colitis, and normal controls. All serum zinc values were within the normal range but significantly lower in the Crohn's disease patients as compared with controls. The taste threshold for salt was significantly impaired in patients with inflammatory bowel disease. These findings were less than expected and may be explained by the relatively high zinc intake normal for the Tel-Aviv population and relate indirectly to the high intake of refined carbohydrate that occurs in Crohn's disease patients.

Adolescent↗