Biomedical subjects
Publications and source records attributed to Y Peled.
Since symptoms of benign and malignant conditions in the vulvar area are frequently similar, early diagnosis and treatment are mandatory. A rare case of a bizarre leiomyoma in the area of Bartholin's gland, which presented as a Bartholin's abscess, is described and discussed.
With the demonstration of pronucleating and antinucleating proteins, the role of biliary proteins became of considerable research interest. Anionic polypeptide fraction is the third most abundant biliary protein; it is found in association with biliary lipids, has antinucleating properties for calcium and is found in gallstones. Its levels in various human biles have not been studied as of this writing. In this investigation the concentration of anionic polypeptide fraction in gallbladder bile was measured in 16 subjects without gallstones, 19 subjects with cholesterol stones and 15 subjects with pigment stones in Tel Aviv. Anionic polypeptide fraction concentrations in bile (mean +/- S.D.) were 0.76 +/- 0.09 gm/L in controls and 0.81 +/- 0.25 gm/L (which was not significant) in patients with cholesterol gallstones. They were significantly higher 1.03 +/- 0.23 (p < 0.05) in patients with pigment gallstones. The anionic polypeptide fraction/phospholipid ratio and the anionic polypeptide fraction/total lipid ratio were significantly higher in patients with pigment gallstones (p < 0.005 and 0.05, respectively). The anionic polypeptide fraction lipid ratios were insignificantly elevated in biles of patients with cholesterol stones compared with the ratios in biles of controls. Only the anionic polypeptide fraction/phospholipid ratio was significantly higher in biles of patients with pigment stones compared with those with cholesterol gallstones. The values were similar although higher in a small group of gallstone patients from Marseilles. The role of anionic polypeptide fraction in the pathogenesis of gallstones, particularly pigment gallstones, requires further study.
Familial congenital pyloric atresia is a rare malformation of the fetal gastrointestinal tract. It usually manifests as maternal polyhydramnios and enlarged fetal stomach on ultrasound scan. Sonographic prenatal diagnosis and management of a pregnancy complicated by familial congenital pyloric atresia are presented.
The exact pathophysiological mechanism of halitosis is not clear, and in many patients the etiology is an enigma. We followed three couples in which one member or both had halitosis. All the subjects had evidence of Helicobacter pylori infection. All received a treatment course of colloidal bismuth subcitrate four times a day and 250 mg metronidazole three times a day. There was impressive improvement in their symptoms, the halitosis disappearing along with eradication of the organism. We call the attention of physicians to the possible connection between halitosis, H. pylori infection, and familial occurrence. Further studies to confirm this surprising association are in order.
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Nucleating factors are thought to be responsible for the more rapid nucleation of gallbladder bile from patients with gallstones as compared to controls. Biliary proteins and, in particular, mucus and non-mucus glycoproteins are the focus of current research. Non-protein nucleating factors were not extensively investigated. In this study we studied the role of free fatty acids (FFA) as possible nucleating factors. Palmitic, oleic and linoleic acid were added to model biles in increasing concentrations from 0 to 20 mu mol/ml. The nucleation time of model biles decreased to 45%-60% of the initial following the addition of 0.5 to 1 mu mol/ml of each of the three fatty acids. Only a small further decrease in the nucleation time was noted with higher concentrations of up to 20 mu mol/ml. The pronucleating effect of FFA added to whole model bile was also examined in the isolated vesicular and non-vesicular fractions. The decrease in the nucleation time at each concentration of the three fatty acids was in the following order of magnitude: whole bile greater than vesicular phase greater than non-vesicular phase. The addition of each of the three fatty acids resulted in a partial solubilization of vesicles, with transfer of their lipid contents to the non-vesicular fraction. The effect was more marked with oleic acid and least marked with linoleic acid. The vesicular cholesterol to phospholipid ratio did not change following the addition of exogenous free fatty acids. Studies with labeled FFA showed that they migrated with the non-vesicular fraction on gel chromatography.(ABSTRACT TRUNCATED AT 250 WORDS)
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The D-xylose absorption test has been used during the last four decades for evaluation of malabsorption in the small intestine. However, some disagreement still exists about the recommended method of performing this test: the 1-hr blood test, the 5-hr urine test, or both. We evaluated the test by performing 125 combined blood and urine tests in 111 patients. Normal xylose absorption was recorded in both blood and urine in 71 tests (group A, 56.8%). Abnormal test results in both blood and urine were recorded in 29 patients (group B, 23.2%). Only one patient had a pathological blood value and normal xylose excretion in the urine. Twenty-four patients (group D, 19.2%) had normal 1-hr blood xylose (greater than 25 mg/100 ml) with abnormal 5-hr urine xylose (less than 4.5 g/5 hr). Fat and/or bile salt malabsorption were documented in 21 patients (87.5%) of this group using stool fat analysis and the [14C]cholylglycine breath test. These data suggest that in adults the 5-hr urine collection more accurately reflects intestinal absorption in comparison with the 1-hr blood value.
Ofloxacin can cause retarded ossification and arthropathy in young animals, but there is no published information about its teratogenicity in humans. A 36-year-old woman was treated with ofloxacin 200 mg bid for 6 days during the 19th week of gestation. Ultrasound follow-up of the measurements and structure of the fetal long bones revealed no abnormalities. The neonate's physical examination and X-rays of the chest and long bones were normal. Although no teratogenic or toxic effects were observed in this patient, the use of ofloxacin in human pregnancy should only be a clinical consideration until sufficient evidence regarding its safety in the human fetus has been published.
Complete solubilization of phosphatidylcholine and cholesterol by bile salts in the form of stable mixed micelles requires that the effective ratio of bile salt/lipids in the mixed micelles (Re = ([bile salt] - critical micellar concentration)/([phosphatidylcholine] + [cholesterol]) will exceed a critical value. This equilibrium solubilizing ratio is an increasing function of the cholesterol/phosphatidylcholine ratio. In contrast, the concentration of sodium cholate required for solubilization of vesicles made of phosphatidylcholine and cholesterol does not increase by increasing the cholesterol/phosphatidylcholine ratio. Consequently, the latter solubilization procedure yields metastable mixed micelles whenever the cholate concentration is higher than that required for vesicle solubilization but lower than that needed for establishing a micellar equilibrium. These metastable mixed micelles undergo partial revesiculation to form cholesterol-rich vesicles that subsequently aggregate. Cholesterol crystallization appears to occur through its reorganization within these aggregated vesicles. The overall rate of the above series of processes increases sharply with the total lipid concentration and with the cholesterol/phosphatidylcholine ratio. The dependence of the rate on the effective ratio of bile salts/lipids is very complex: at any given ratio of cholesterol/phosphatidylcholine within the range of 0.3 to 0.5, increasing the cholesterol/phosphatidylcholine ratio requires higher cholate concentrations for the formation of stable mixed micelles (higher equilibrium solubilizing ratio). On the other hand, the metastable mixed micellar larsystems are long-lived whenever the effective ratio of cholate/lipids is lower than a critical value.(ABSTRACT TRUNCATED AT 250 WORDS)
Biliary cholesterol nucleates primarily from phospholipid vesicles. In this study, we investigated the mode of nucleation of micellar cholesterol. Ten biles (four human and six model) were examined. The vesicular and micellar fractions of each bile were separated by gel chromatography. The whole biles and their isolated carriers were incubated at 37 degrees C until nucleation time. In whole human biles, the proportion of total cholesterol in vesicles rose throughout the incubation (from zero time to nucleation time) from 15.5 +/- 8.6% to 28.0 +/- 12.5%, and in model biles from 46.8 +/- 22.4% to 75.5 +/- 8.2%. The vesicular isolated fraction remained unchanged throughout incubation. In isolated micelles devoid of vesicles at zero time, new vesicles formed during incubation, carrying increasing proportions of cholesterol. At nucleation time, these vesicles contained 11.0% of originally micellar cholesterol in human biles, and 41.2% in model biles. The new vesicles formed in whole bile and in the micellar fraction were chromatographically and chemically similar to the vesicles originally present in bile. These data suggest that micellar cholesterol nucleates via the neoformation of phospholipid vesicles, which seem to be the final common pathway for cholesterol nucleation in bile.
In searching for a screening test to identify a population at high risk for large bowel cancer, methane production was measured in 45 patients with colorectal carcinoma compared with 67 individuals who served as a control group. There was no significant difference in methane production between the colorectal cancer patients and the control group (37.8 and 25.4% respectively). Within the colorectal cancer group 54% of the males were methane producers compared with 19% of the females (P = 0.03). There were no differences according to disease stage. In view of these results, we see little value in using expired air methane concentration as a screening test for large bowel cancer.
Phospholipid peroxidation markedly reduces the stability of mixed micellar systems composed of cholate, phosphatidylcholine and supersaturating levels of cholesterol. This suggests that lipid peroxidation is likely to play a significant role in the precipitation of cholesterol from gallbladder bile, thus in the pathogenesis of cholesterol gallstones. This conclusion is supported by studies of the nucleation time of cholesterol in gallbladder biles, which was significantly reduced by exposure to a stream of oxygen. This effect of phospholipid peroxidation on cholesterol solubility may occur in other biological fluids as well. In view of the increased lipid peroxidation in the elderly, it may explain the effect of age on the frequency of various diseases related to cholesterol precipitation.
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The maximal equilibrium solubility of cholesterol in mixtures of phosphatidylcholine (PC)1 and bile salts depends on the cholesterol/PC ratio (Rc) and on the effective ratio (Re) between nonmonomeric bile salts and the sum (CT) of PC and cholesterol concentrations (Carey and Small, 1978; Lichtenberg et al., 1984). By contrast, the concentration of bile salts required for solubilization of liposomes made of PC and cholesterol does not depend on Rc (Lichtenberg et al., 1984 and 1988). Thus, for Rc greater than 0.4, solubilization of the PC-cholesterol liposomes yields PC-cholesterol-bile salts mixed micellar systems which are supersaturated with cholesterol. In these metastable systems, the mixed micelles spontaneously undergo partial revesiculation followed by crystallization of cholesterol. The rate of the latter processes depends upon Rc, Re, and CT. For any given Rc and Re, the rate of revesiculation increases dramatically with increasing the lipid concentration CT, reflecting the involvement of many mixed micelles in the formation of each vesicle. The rate also increases, for any given CT and Re, upon increasing the cholesterol to PC ratio, Rc, probably due to the increasing degree of supersaturation. Increasing the cholate to lipid effective ratio, Re, by elevation of cholate concentration at constant Rc and CT has a complex effect on the rate of the revesiculation process. As expected, cholate concentration higher than that required for complete solubilization at equilibrium yields stable mixed micellar systems which do not undergo revesiculation, but for lower cholate concentrations decreasing the degree of supersaturation (by increasing [cholate]) results in faster revesiculation. We interpret these results in terms of the structure of the mixed micelles; micelles with two or more PC molecules per one molecule of cholesterol are relatively stable but increasing the bile salt concentration may cause dissociation of such 1:2 cholesterol:PC complexes, hence reducing the stability of the mixed micellar dispersions. The instability of PC-cholesterol-cholate mixed systems with intermediary range of cholate to lipids ratio may be significant to gallbladder stone formation as: (a) biliary bile contains PC-cholesterol vesicles which may be, at least partially, solubilized by bile salts during the process of bile concentration in the gallbladder, resulting in mixtures similar to our model systems; and (b) the bile composition of cholesterol gallstone patients is within an intermediary range of bile salts to lipids ratio.
Breath methane was studied in 394 subjects. Among 152 controls, 50.0% produced methane--42.1% of males and 57.9% of females. One hundred sixteen patients with gastrointestinal diseases were studied. Among 32 with Crohn's disease, only 2 (6.1%) produced methane, as well as 16 of 51 ulcerative colitis patients (31.4%) and 11 of 32 patients with the irritable bowel syndrome (34.4%). Breath methane is thus unusual in Crohn's disease. After bowel cleansing for colonoscopy or surgery, 15 of 18 methane producers became nonproducers, whereas after antibiotic treatment, 24 of 30 producers sustained their methane-producing status. After gentamycin and cephazolin therapy, methane production was abolished in three of eight patients. Slight spontaneous variations in methane production were also noticed with two of 23 control subjects, becoming nonproducers on restudy after 10-25 months. Thus gastrointestinal diseases, bowel cleansing and, to a much lesser degree, antibiotic therapy, affect methane production.
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Bromsulfophthalein (BSP) clearance and aminopyrine breath tests were performed in 13 patients with Gilbert's syndrome (GS) and six healthy volunteers. The BSP clearance was significantly lower in the GS patients (1.28 +/- 0.37 dl/min) than in the healthy volunteers (1.98 +/- 0.45 dl/min). The difference in clearance was not due to a significant difference in volume of distribution. The 13 patients with Gilbert's syndrome could be divided into three groups according to their BSP disappearance curves: in 7 the curves were normal; another 3 patients the disappearance rate of BSP was normal at the beginning, but became abnormally low later on; and in the last 3 patients, an abnormal BSP disappearance rate was observed during the whole experiment. Kinetic analysis of these BSP disappearance curves indicated increased regurgitation of BSP from the liver to the blood in the second group and defective hepatic BSP uptake in the third group. The aminopyrine breath test also demonstrated heterogeneity among the GS patients. There was no correlation between the impaired BSP clearance and the aminopyrine breath test.