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Biomedical subjects

P Levy

Publications and source records attributed to P Levy.

At least 127 records · Page 7Linked to original sources
PubMed1988

Biosynthesis of glycosaminoglycans in the human colonic tumor cell line Caco-2: structural changes occurring with the morphological differentiation of the cells.

The human colon cancer cell line Caco-2 cultured in vitro displayed morphological differentiation which was shown to be a growth-related event. We have investigated this phenomenon further in relation to the cell surface glycosaminoglycans produced by growing (5-day, i.e., prior to differentiation) and confluent (9-day, i.e., after morphological and functional differentiation) cultures. Neosynthesized [35S]glycosaminoglycans were purified on DEAE-cellulose; at confluency, they were bound more strongly to the column than the corresponding fractions from the growing cells. Analysis of Kav values of heparan sulfate and chondroitin sulfates from growing and confluent cells indicated an increase in chain length of both glycosaminoglycans in morphologically differentiated cells. Heparan sulfate was the main 35S-labeled glycosaminoglycan of the cell surface of both 5-day and 9-day cultures. Paper chromatography of the unsaturated disaccharides obtained by chondroitinase digestion showed that chondroitin sulfate chains were primarily 6-sulfated in the 2 studied extracts. Heparan sulfate chains were isolated as chondroitinase-resistant material and treated with nitrous acid. Analysis of N- and O-sulfate group-related radioactivity showed an increase in the amount of 35S-label in the form of N-sulfate groups and an increase in the O-35S-sulfation pattern in heparan sulfate from morphologically differentiated cells. Thus, the structural features of both chondroitin sulfates and heparan sulfate were significantly different when the growing cells became morphologically differentiated.

Cell Differentiation↗
PubMed1987

Pseudoaneurysm of the left ventricle.

Pseudoaneurysm of the left ventricle is relatively rare. Five patients aged 50-61 years with this disorder are the subject of this report. In 4, the pseudoaneurysm occurred following myocardial infarction and in one after aortic valve replacement. The symptoms appeared 3 months to 12 years after the primary event. Clinically, all were admitted with congestive heart failure combined with some degree of angina. In four patients the diagnosis was made by ventriculography and in one case by a multiple gated acquisition radionucleide scan (MUGA). All were operated on soon after diagnosis. In two patients direct suture closure of the orifice was carried out, while in the other three a synthetic patch was necessary to close the aperture. Four patients survived operation and are well two to 14 years following surgery. The literature on post infarction pseudoaneurysm is reviewed and analyzed. This study argues for early surgical treatment, affording relatively low postoperative mortality.

Female↗
PubMed1987

[Sleep apnea syndrome combined with an anatomical obstruction of the upper airways].

In patients with sleep apnoea syndrome abnormalities of the upper airways may play a major role in the genesis of apnoea. Three cases are presented which illustrate the part played by hypertrophy of the tonsils in a child and by stenosis of the pharynx in an adult and of the larynx in another adult. All three patients were cured by surgical correction of these abnormalities. The physiopathology of alveolar hypoventilation, present in one of the three patients, is discussed in relation to the effects of pure oxygen inhalation on the patient's ventilation.

Adult↗
PubMed1987

[Transparietal needle biopsy of pulmonary lesions with an image intensification system. Apropos of 82 biopsies].

We report the results of 82 needle biopsies of pulmonary nodules, using a fine screw needle. Owing to the very small diameter of the needle (0.8 mm), very few complications were observed (minor pneumothorax 13%, major pneumothorax 2.5%). The screw needle provided samples adequate for both cytological and histological examination. Forty-eight out of 53 cancers were diagnosed by this method (sensitivity 83%, specificity 100%).

Biopsy, Needle↗
PubMed1987

[Primary alveolar hypoventilation. Clinical aspects and diagnostic problems. Apropos of a case].

Primary alveolar hypoventilation is a rare syndrome of unknown origin, characterized by a dysfunction of the automatic respiratory pattern in spite of normal lungs and in the absence of mechanical ventilatory defects. A reduction of the ventilatory response to CO2 is regularly found, and cardiac failure is common. The differential diagnosis mainly concerns the sleep apnoea syndrome. The usual treatments have little effectiveness.

Blood Gas Analysis↗
PubMed1986

Non-iatrogenic deep vein thrombosis of lower extremities in children.

Non-iatrogenic ileo-femoral vein thrombosis is rarely encountered in childhood. Six children with postphlebitic leg following venous thrombosis are presented. Venous thrombosis occurred following peritonitis, osteomyelitis and scarlet fever. None of the patients had history of trauma or intravenous treatment. Based on world literature and our experience, the main clinical and radiological manifestations of this rare entity are summarised. Early detection and aggressive anti-coagulant therapy of deep vein thrombosis may probably prevent post-thrombotic syndrome--a major disabling condition in children.

Adolescent↗
PubMed1986

Chemical properties of water-soluble porphyrins. 5. Reactions of some manganese (III) porphyrins with the superoxide and other reducing radicals.

Solution properties of three manganese porphyrins, in monomeric form, were investigated. These were the 'picket-fence-like' porphyrin Mn(III)-alpha,alpha,alpha,beta- tetra-ortho(N-methylisonicotinamidophenyl)porphyrin (Mn(III)PFP) and two 'planar unhindered' porphyrins, the Mn(III)TMPyP (tetrakis (4-N-methylpyridyl)porphyrin) and Mn(III)TAP (tetra(4-N,N,N-trimethylanilinium)porphyrin). The porphyrin properties studied were: the absorption spectra in their manganic and manganous forms; acid/base properties of the aquo complexes; the effect of potential axial ligands (up to a concentration of 0.1 mol dm-3) and their one electron reduction potentials. Knowing these properties, the reaction of the Mn(III) porphyrins with the superoxide radical and other reducing radicals were studied using the pulse radiolysis technique. The second-order reaction rate constant of O2- with the Mn(III) porphyrins, which governs the catalytic efficiency of the metalloporphyrins upon the disproportionation of the superoxide radical, was 5.1 X 10(7) to 4.0 X 10(5) dm3 mol-1 s-1, depending on the pH and the nature of the metalloporphyrin. These values are at least one order of magnitude lower than found for Fe(III)TMPyP. One electron reduction of the three Mn(III) porphyrins by eaq-, CO2-, CH2OH and (CH3)2COH had similar second-order rate constants (10(9)-10(10) dm3 mol-1 s-1). That for (CH3)2(CH2)COH was about 10(5) dm3 mol-1 s-1. Reduction in all cases produced the corresponding Mn(II) porphyrin and no intermediate was found. The oxidation reaction of the Mn(II) porphyrins by O2- was approximately two orders of magnitude faster when compared to the reduction of Mn(III) porphyrins with the same radical. Since the reactivities of O2- towards the three manganese (III) compounds follow their reduction potentials, it is suggested that these reactions are governed by an outer-sphere mechanism. This suggestion is corroborated by the finding that water molecules acting as axial ligands, in these aqueous solution systems, are not replaced by another potential ligand when the latter is in the concentration range of 100 mM or less.

Manganese↗
PubMed1986

Time trends in the US racial difference in hypertension.

This paper explores time trends in racial differences in hypertension and in mortality from complications from hypertension in the United States. Mortality data were derived from death certificate data compiled by the National Center for Health Statistics and presented in the 1981 Report of the Working Group on Arteriosclerosis. Prevalence data were obtained from five populations--6,672 people screened in 1960-1962 by the National Health Examination Survey (NHES); 20,749 screened in 1971-1975 by the Health and Nutrition Examination Survey (HANES I); 158,539 screened in 1973-1974 by the Hypertension Detection and Followup Program (HDFP); 1 million persons screened in 1973-1975 by the Community Hypertension Evaluation Clinics (CHEC); and 20,325 screened in 1976-1980 by the second Health and Nutrition Examination Survey (HANES II). Mortality data indicate that the nonwhite/white ratios for mortality from complications of hypertension increased between 1940 and 1967 and decreased between 1968 and 1978. Prevalence data show a corresponding recent decrease in black minus white mean blood pressure. Some of the decrease appears to be due to a greater improvement in hypertension control for blacks than for whites. Time trends in the black/white ratio in prevalence of hypertension were examined with differential treatment effects controlled by inclusion as hypertensive those on drug therapy. The results indicate that in addition to differential changes in therapy, the ratio of black/white prevalence of hypertension may also be decreasing. Additional studies are needed to confirm this finding and to explore time changes in racial patterns of risk factors for hypertension.

Black People↗
PubMed1986

Biliary elimination of cefotiam, an experimental and clinical study.

Five isolated rabbit livers were in vitro perfused over a 3-hour period. After addition of 10 mg of cefotiam to the circulating blood, a biliary peak concentration of 76.2 +/- 14.2 micrograms/ml (mean +/- SEM) was reached between the 90th and 120th min; 3.1 +/- 0.4% of the dose given was excreted in the bile during the 3-hour period. In 10 recently cholecystectomized patients provided with a T-tube drain, 1 g of cefotiam was given intravenously. A biliary peak concentration of 340 +/- 81 micrograms/ml was observed 2 h later. 1.8 +/- 0.7% of the administered dose was recovered in the bile during the 12-hour period. In 5 clinically normal subjects given intravenously 1 g of cefotiam, 0.5 +/- 0.2% of the administered dose was found in the duodenal fluid aspirated over a 4-hour period. Cefotiam concentrations measured in choledochal and gallbladder bile collected simultaneously during operation 1 h after intravenous administration of 1 g of the drug to 10 patients were 502 +/- 102 micrograms/ml and 143 +/- 39 micrograms/ml, respectively; they exceeded significantly the concentration determined in the serum sampled at the same time (17.9 +/- 2.6 micrograms/ml). The biliary parameters of cefotiam were compared with those of 14 other beta-lactam antibiotics previously studied by the same procedure. The results of the present study are consistent with a possible beneficial effect of cefotiam in the treatment of biliary tract infections.

Animals↗
PubMed1986

[Value of computed tomography in the diagnosis of the intrathoracic extension of bronchial cancer].

In 76 patients the diagnosis of the mediastinal extension of a bronchial cancer, assessed by computed tomography (CT), was compared to histological specimens obtained by mediastinoscopy and surgery (58/76). The extension to mediastinal nodes was present in 26 subjects (34.2%) and yet was not recognised 15 times on CT. There were 15 false negatives (FN) and 3 false positives (FP). Sensitivity 43%, specificity 94%, predictive value for positives (VPP) 70%, predictive value for negatives (VPN) 75%. Extension was present in 18 patients. These were recognised 14 times by CT. There were no false positives. (Sensitivity 70%, specificity 100%, VPP 100%, VPN 94%). We conclude That CT is useful for diagnosing direct mediastinal extension and allows the juxta-hilar extension of the cancer to be assessed. CT has no place in the diagnosis of mediastinal gland involvement. Mediastinoscopy (5.2% FN; no FP) is better than TDM for the diagnosis of extension to the mediastinal nodes both for peripheral and central cancers.

Carcinoma, Bronchogenic↗
PubMed1985

Comparison of high-pressure liquid chromatography and microbiological assay for the determination of biliary elimination of ciprofloxacin in humans.

Serum kinetics and biliary, urinary, and fecal elimination of ciprofloxacin, a new quinolone derivative, were studied in 12 recently cholecystectomized patients provided with T-tube drainage during 24 h after oral administration of a single 500-mg dose of this substance. Drug concentrations were measured by both high-pressure liquid chromatography (HPLC) and microbiological assay. The results were comparable for the concentrations in serum (average of peaks, 2.0 +/- 0.2 micrograms/ml by HPLC and 2.3 +/- 0.3 micrograms/ml by the microbiological method) and urine (0 to 6 h, 267 +/- 74 and 241 +/- 58 micrograms/ml, respectively). This was not the case for biliary values, for which the microbiological assay yielded significantly higher concentrations than did HPLC (average of peak concentrations, 21.2 +/- 2.6 and 16.0 +/- 2.5 micrograms/ml, respectively [P less than 0.02]), nor for total 24-h biliary output (2,167 +/- 288 and 1,587 +/- 222 micrograms, respectively [P less than 0.01]). This suggests hepatic biotransformation of ciprofloxacin into microbiologically active metabolites. The apparent broad antibacterial spectrum of ciprofloxacin and its higher biliary levels than simultaneously determined serum concentrations suggest that this derivative is suitable for the treatment of biliary tract infections.

Adult↗
PubMed1985

Local anesthesia in carotid endarterectomy: an alternative method.

Results of carotid endarterectomy (41 operations) carried out under local anesthesia are presented. There were no deaths within 30 days. Three patients had undergone surgery with a temporary internal shunt, following signs of neurological changes (unconsciousness, aphasia, motor changes) during 1-min test cross-clamping. No neurologic deficits were observed, and only two patients (4.8%) experienced postoperative hypertension. These data support the view that simple neurological monitoring of awake patients enables accurate assessment of the need for an internal carotid shunt. Carotid endarterectomy under local anesthesia seems to be a very safe procedure. Use of this technique is especially appropriate for elderly patients with hypertension and ischemic heart disease.

Aged↗
PubMed1984

[Pulmonary arterial pressure in chronic bronchitis with respiratory insufficiency on long-term oxygen therapy. Outcome of 16 patients with review of the literature].

A study was made of pulmonary artery pressure in 16 chronic bronchitics with severe respiratory failure, who were treated with continuous oxygen therapy at home. At the beginning of the study these patients presented with a pure and severe obstructive syndrome with marked hypoxaemia at rest (mean PaO2 = 6.8 kPa), had a suitable interval from a recent exacerbation, in a stable clinical and functional respiratory state. The duration of longterm oxygen therapy was controlled, as the efficacy of the blood gases (PaO2 of O2 greater than or equal to 8 kPa). The pulmonary artery pressure was measured using a microcatheter, at the beginning, and for most of the 18 months breathing ambient air in a stable state. At the end of this time a significant diminution of the FEV1 (VEMS) (a mean of 100 ml, p less than 0.01). This was evidence of the deterioration in the ventilatory state which contrasted with the improvement in the diminution of pulmonary artery hypertension (HTAP) from 3.43 to 2.97 kPa (p less than 0.05) without the deterioration in the other values. The good result above in chronic bronchitics contrasts with a stable or deteriorating pulmonary arterial pressure in a group of emphysematous (n = 6) and bronchiectatic subjects (n = 4) with somewhat similar functional characteristics but in whom the effect was too small to allow for any statistical comparison. Our results are compared with those in the literature much of which applies to only a few patients and for the great part revealed only haemodynamic stability of oxygen therapy. Possible reasons for these discordant findings are discussed.

Blood Pressure↗