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Biomedical subjects

A Denys

Publications and source records attributed to A Denys.

At least 73 records · Page 4Linked to original sources
PubMed1997

[Congenital cystic dilatation of the common bile duct. Radio-anatomical correlations in 14 patients].

OBJECTIVES: The aim of this study was to compare imaging and pathological results of congenital cystic enlargement of the biliary tract to determine the best preoperative management strategy. PATIENTS AND METHODS: Radiological findings of 14 cases treated by surgery were reviewed. Radiological examinations were reviewed: ultrasound (n = 20), computed tomography (n = 13), endoscopic ultrasound (n = 8), endoscopic retrograde cholangiopancreatography (n = 10), percutaneous transhepatic cholangiography (n = 3), peroperative cholangiography (n = 11). Imaging and surgical or pathological correlations were obtained with regard to topographical type using Todani's classification, pancreatobiliary junction, and associated diseases, especially biliary malignancies (cystic wall and gallbladder). RESULTS: Cystic enlargement of the biliary tract was type Ia in 2 patients, type Ib in 1, type Ic in 4, type IVa in 5, and type IVb in 2. The radio-pathological correlation was excellent for the topographical type, and quite good for intrahepatic extension. An abnormal pancreatobiliary junction was identified in 5 cases, and visualized before surgery in I case. This junction was not opacified pre- or pre-operatively in 7 cases. Gallbladder stones were present in 2 cases, choledocal stones, in 2 cases, and intrahepatic stones in one cases, always seen on ultrasound. Malignant degeneration was present in the cyst in one case in the pathological specimen, but was not visualized by imaging procedures or peroperatively; one intrahepatic degeneration was visualized on CT and histologically proven in the surgical specimen. CONCLUSION: Ultrasound and CT allow positive diagnosis of cystic enlargement of the biliary tract, and diagnosis of intrahepatic cyst and associated diseases. The bifurcation extension and the study of pancreatobiliary junction require peroperative or retrograde cholangiography.

Adolescent↗
PubMed1997

[Comparison of scanners and porto-scanners, both in helical mode, for the study of hepatic metastases. Prospective study in 12 patients].

PURPOSE: The aim of this study was to compare helical CTAP and helical CT-scan in the preoperative assessment of liver metastases. METHODS: A prospective unicentric study in 12 patients was performed with helical CTAP and helical CT-scan. All patients underwent partial hepatectomy with intraoperative palpation and sonography within 19 days (mean: 9 days). RESULTS: Examination of resected liver specimens found 38 metastases, from colorectal cancer in 36 cases. The sensitivity was 92.1% for helical CTAP and 79% for helical CT-scan. This sensitivity was 85% for helical CTAP and 60% for helical CT-scan for nodules 1 cm or less in diameter (P = 0.08). CONCLUSION: In the preoperative screening of liver metastases, helical CT-scan should be performed as the first choice examination. When hepatic lesions seem to be curable by resection based on helical dynamic CT-scan results, helical CTAP should be performed to increase the sensitivity of detection of lesions 1 cm or less in diameter.

Adult↗
PubMed1997

[Imaging of atypical cysts of the liver. Study of 26 surgically treated cases].

OBJECTIVES: Differential diagnosis between a benign cystic hepatic lesion, biliary cyst, and a potentially malignant lesion or biliary cystadenoma, is difficult. The aim of this study was to evaluate imaging features of atypical cystic liver lesions and the role of imaging techniques in determining a specific diagnosis. METHODS: Twenty-six patients with atypical cystic hepatic lesions were included in this study. All patients underwent surgery and pathological diagnosis was atypical hepatic cyst (n = 18), biliary cystadenoma (n = 4), hydatic cyst (n = 3), and ciliated hepatic foregut cyst (n = 1). We systematically reviewed US (n = 24), CT (n = 24), and MRI (n = 8) examinations. RESULTS: Septum were seen in both cystadenomas (US: n = 4, CT: n = 1) and hepatic cysts (US: n = 11, CT: n = 6). No mural nodules were seen. A thin wall was noted in both hepatic cysts (n = 2) and cystadenomas (n = 3). The intrahepatic biliary tract was dilated in 3 patients with hepatic cysts, 1 patient with cystadenoma, and 2 patients with hydatic cysts. Calcifications were noted in 1 patient with hepatic cyst, 3 patients with hydatic cysts, and in the case of ciliated hepatic foregut cyst. We found an associated typical hepatic cyst in 77% of cases (14/18) with atypical hepatic cysts; this was never found in other atypical cystic lesions (P < 0.01). CONCLUSION: In this series, no imaging features provided a differential diagnosis of atypical hepatic cysts and cystadenomas. The presence of associated typical hepatic cysts is helpful in suggesting the diagnosis of hepatic cyst.

Adult↗
PubMed1997

[Theoretical basis for the antibiotic therapy of the upper part of the respiratory system].

The paper presents the views on the etiology of infections in the respiratory system. Beside the so called "old pathogens" such as Streptococcus pneumoniae, Haenophilus influenzae, Moraxella catarrhalis, "atypic" microorganisms are becoming more and more important, i.e. Mycoplasma pneumoniae, Legionella pneumophila, Chlamydia pneumoniae. Mixed flora with aerobic and anaerobic bacteria is observed in chronic infections. Viral infections facilitate bacterial infections. Antibiotic used first should be active against the "old" and "new" pathogens. Future prospects are set on macrolides such as clarythromycin.

Anti-Bacterial Agents↗
PubMed1997

[Practical implications of bacterial resistance to antibiotics. Attempts to fight it].

Generation of strains resistant to antibiotics, its genetic mechanisms and the role of incompetent administration of these drugs are presented in the paper. The resistance is characterised mainly by the generation of extracellular enzymes which cause the breakdown of beta-lactam ring Pathogenic bacteria which cause changes in the respiratory system are discussed. The use of beta-lactam antibiotics with beta-lactam inhibitors is a way to prevent generation of resistant strains, the combination of amoxycillin and clavulanic acid is of particular importance.

Amoxicillin↗
PubMed1996

Cyclophilin B mediates cyclosporin A incorporation in human blood T-lymphocytes through the specific binding of complexed drug to the cell surface.

Cyclophilin B (CyPB) is a cyclosporin A (CsA)-binding protein located within intracellular vesicles and released in biological fluids. We recently reported the specific binding of this protein to T-cell surface receptor which is internalized even in the presence of CsA. These results suggest that CyPB might target the drug to lymphocytes and consequently modify its activity. To verify this hypothesis, we have first investigated the binding capacity and internalization of the CsA-CyPB complex in human peripheral blood T-lymphocytes and secondly compared the inhibitory effect of both free and CyPB-complexed CsA on the CD3-induced activation and proliferation of T-cells. Here, we present evidence that both the CsA-CyPB complex and free CyPB bind to the T-lymphocyte surface, with similar values of Kd and number of sites. At 37 degrees C, the complex is internalized but, in contrast to the protein, the drug is accumulated within the cell. Moreover, CyPB receptors are internalized together with the ligand and rapidly recycled to the cell surface. Finally, we demonstrate that CyPB-complexed CsA remains as efficient as uncomplexed CsA and that CyPB enhances the immunosuppressive activity of the drug. Taken together, our results support the hypothesis that surface CyPB receptors may be related to the selective and variable action of CsA, through specific binding and targeting of the CyPB-CsA complex to peripheral blood T-lymphocytes.

Amino Acid Isomerases↗
PubMed1996

Involvement of the N-terminal part of cyclophilin B in the interaction with specific Jurkat T-cell binding sites.

Cyclophilin B (CyPB) is secreted in biological fluids such as blood or milk and binds to a specific receptor present on the human lymphoblastic cell line Jurkat and on human peripheral blood lymphocytes. This study was intended to specify the areas of CyPB that are involved in the interaction with the receptor. A synthetic peptide corresponding to the first 24 N-terminal amino acid residues of CyPB was shown to specifically recognize the receptor. Moreover, modification of Arg18 of CyPB by p-hydroxyphenlglyoxal led to a dramatic loss of affinity for the receptor. However, when this residue was replaced by an alanine residue using site-directed mutagenesis, no modification of the binding properties was found, suggesting that Arg18 is not directly involved but is sufficiently close to the interaction site to interfere with the binding when modified. Competitive binding experiments using a chimaeric protein made up of the 24 N-terminal amino acid residues of CyPB fused to the cyclophilin A core sequence confirmed the involvement of this region of CyPB in receptor binding.

Amino Acid Isomerases↗
PubMed1996

Does the Ukrain preparation protect mice against lethal doses of bacteria?

Ukrain, a semi-synthetic preparation obtained from Chelidonium majus L, is used in the treatment of cancer diseases. It has been observed to exert a protective influence in mice infected by influenza viruses. Recently, the influence of the preparation on the survival of mice infected by lethal doses of E. coli and S. aureus has been estimated. This preparation was administered to Balb/c mice subcutaneously in doses of 0.04, 0.4 and 4.0 mg/kg of body weight. Ukrain was given every second day during 20 days, or a short-term before-and-after method at 48, 24 and 2 h before the infection and or 2, 24 and 48 h after the infection of mice. The mice were infected intraperitoneally with E. coli or S. aureus in doses equivalent to 2LD50. Increased survival of mice, depending on the dose of the preparation and the kind of infecting bacterium was observed. The highest survival (50%) occurred in mice infected with E. coli and receiving the amount of the preparation corresponding to 0.4 mg/kg. The lowest survival was observed in mice infected by S. aureus and receiving the preparation in the amount of 4.0 mg/kg. Higher protective effectiveness of the Ukrain preparation was observed in mice when the preparation had been administered during 20 days as compared to the short-term before-and-after regime.

Alkaloids↗
PubMed1996

Estimation of direct influence of Ukrain preparation on influenza viruses and the bacteria E. coli and S. aureus.

Ukrain is a semisynthetic drug with immunomodulatory properties derived from Chelidonium majus L. alkaloids and thiophosphoric acid. It acts selectively in a lytic way on cancer cells. Its protective properties have been shown in mice infected by influenza viruses. In this paper, the studies made on the estimation of the direct activity of Ukrain preparation on viruses and bacteria E. coli and S. aureus are described. Viruses of different haemagglutination titres were incubated with different concentrations of the preparation during period of 1, 2 and 24 h. Afterwards the samples were collected and used for the infection of the allantoic cavity obtained from 10-day-old hen embryos. A second method was based on the introduction of the Ukrain preparation into the allantoic cavity of embryos before infection with influenza viruses and after the infection of embryos. In both the described methods, the embryos were incubated within 48 hours. Then the presence of influenza viruses in allantoic fluid was estimated using a haemagglutination reaction with 30% hen blood cells. The influence of the preparation on hen embryo was also studied. In order to estimate the antibacterial activity the following procedure was used. To the preparation diluted with the growth medium from 500 micrograms/ml to 1 microgram/ml a definite amount of the bacteria S. aureus or E. coli was added, and after 24 and 48 h of incubation at 37 degrees C the results were read off. In the second method, the bacteria were added to 1, 10, 100 and 500 micrograms of the preparation in 1.0 ml of 0.85% NaCl, and after 1, 2 and 24 of incubation at room temperature the samples were collected and inoculated on solid Mueller-Hinton medium. The presence of bacterial growth or medium turbidity after 24 and 48 h of incubation was taken as a positive result. Our studies have revealed that the above mentioned preparation does not exert any negative influence on hen embryos that could make it difficult to estimate replication of influenza viruses. This preparation did not show any direct influence on the inactivation of influenza viruses and the bacteria E. coli and S. aureus.

Alkaloids↗
PubMed1996

[Selected immune response parameters in respiratory tract infections in mice--effect of combined treatment with tienamycin and coparvax].

The combined model of viral/bacterial infections has been used in the study. Tienamycin and Coparvax have been administered to infected mice. During the time of 3, 6, 9 and 14 days the hemagglutination inhibition reactions, migration inhibition of leukocytes, phagocytic activity and killing effect of the peritoneal exudate granulocytes have been made. The analysis of migration inhibition of leukocytes gave a statistically characteristic answer after using antigen of anatoxin compared to influenza antigen. In the group of animals which were treated with tienamycin and Coparvax a higher percentage of migration inhibition was observed than in the other group are substantial in the reaction of phagocytosis. Generally, a more beneficial influence of the combined treatment with tienamycin and coparvax has been observed.

Adjuvants, Immunologic↗
PubMed1996

[Microbiological evaluation of ciprofloxacin efficacy for treatment of urinary tract infections].

An attempt has been undertaken to evaluate the aetiology of urinary tract infections in a large group of patients and to determine the resistance to ciprofloxacin during therapy, and the efficacy of the drug in treating of urinary tract infections. 52 patients with urinary tract infections were treated with ciprofloxacin. Ciprobay by BAYER was used in coated 500 mg tablets twice a day and intravenous solutions in 200 mg dosages every 12 hours for 10-14 days depending on the clinical condition. Microbiological tests were made according to general methods. Sensitivity evaluation to ciprofloxacin was done using E-tests by AB Biodisk and dilution tests. The most common a etiology of urinary tract infections were Gram-negative Enterobacteriaceae rods, mainly E. coli. Ciprofloxacin gave the best results against Enterobacteriaceae rods (100% eradications). In other infections, effective therapy was possible after determining of the sensitivity in vitro. S. haemolyticus bacteria tended significantly towards resistance to ciprofloxacin during therapy.

Anti-Infective Agents↗
PubMed1995

Circulatory alterations induced by intra-arterial injection of iodized oil and emulsions of iodized oil and doxorubicin: experimental study.

PURPOSE: To evaluate circulatory alterations induced by intra-arterial injection of iodized oil and emulsions of iodized oil with an anticancer drug. MATERIALS AND METHODS: The viscosities and stability were evaluated in arterial flow of iodized oil and the emulsions. Doppler ultrasound was used to quantify the embolic effect in the arteries of rabbits. The behavior of doxorubicin and iodized oil in the rat cremaster muscle was studied with videomicroscopy. RESULTS: The emulsions did not break up after injection, and the size of discontinuous-phase droplets did not change. The embolic effect did not correlate with viscosity. The thinnest water-in-oil emulsion had the lowest embolic effect and induced homogeneous distribution of iodized oil droplets in the arterial tree. CONCLUSION: Changes in the formulation of emulsions obtained with the same proportions of drug and iodized oil change the distribution of iodized oil in the arterial tree, the location at which the drug is released, and the embolic effect.

Abdominal Muscles↗
PubMed1995

Short- and long-term hemodynamic effects of transjugular intrahepatic portosystemic shunts: a Doppler/manometric correlative study.

OBJECTIVE: The purposes of this study were to evaluate the effect of a well-functioning transjugular intrahepatic portosystemic shunt (TIPS) on the splanchnic and intrahepatic circulation, to determine if sonographic measurements can predict shunt dysfunction before clinical manifestations of portal hypertension occur, and to compare Doppler sonographic findings with portocaval gradient measurements before and after shunt revision. SUBJECTS AND METHODS: Forty-four patients with cirrhosis (n = 43) and myelofibrosis (n = 1) who underwent successful TIPS insertion were included in this prospective study. Indications for TIPS placement were: refractory ascites (24 patients), bleeding esophageal varices (17 patients), portal hypertensive gastropathy (two patients), and bleeding colonic varices (one patient). The portal vein and the inferior vena cava were catheterized; and the portocaval gradient was recorded before TIPS placement, at 2 and 12 months after TIPS placement, and when clinical or Doppler findings suggested shunt dysfunction. Doppler studies were done within 1 week before TIPS placement, within 2 days after TIPS placement, every 2-3 months thereafter, and before and after a TIPS revision. The Doppler studies included flow volume measurements in the portal vein and in the stent, as well as determination of the direction of flow in the segmental branches of the portal vein, in the splanchnic veins, and in portosystemic collaterals. Changes in Doppler findings and in catheter pressure measurements were compared using Spearman's rank correlation test. Significance was set at the .05 level. RESULTS: A marked decrease (-51%) in portocaval gradient was observed after TIPS placement. At Doppler sonography, portal vein velocity and diameter were both higher after TIPS placement, resulting in a marked increase in portal venous flow (170%). Mean flow velocity in the shunt was 55.8 +/- 3.6 cm/sec, and flow volumes in the shunt and in the main portal vein were 1596 ml/min and 1731 ml/min, respectively (p = nonsignificant). Dysfunction of the stent occurred in 27% of the patients. Changes in stent blood flow volume were closely related to changes in the portocaval gradient (r = -0.67, p < .001). Reduction of blood flow volume in the stent or change of direction of flow in intrahepatic portal veins or in collateral veins signaled shunt dysfunction (84% sensitivity, 89% specificity). CONCLUSION: Marked hemodynamic changes in the portal venous system occur soon after a TIPS procedure. Monitoring of shunt function with periodic Doppler sonography, including calculation of shunt blood flow, is useful in detecting shunt dysfunction before clinical signs occur.

Adult↗
PubMed1995

Focal sparing of liver parenchyma in steatosis: role of the gallbladder and its vessels.

The purpose of this study was to determine the prevalence and localization of focal areas of sparing in a population of patients with fatty infiltration (steatosis) of the liver. We also sought to determine if the blood supply of the gallbladder has an effect on fatty infiltration of the liver adjacent to it. We studied 290 patients with sonographic signs of fatty infiltration of the liver with gray scale sonography. In 58 of the patients, the gallbladder had been removed previously. A zone of focal sparing was found in 67% of patients with liver steatosis (78% in patients with an intact gallbladder versus 33% in patients with previous cholecystectomy). In patients with an intact gallbladder, segments 4 and 5 were spared most often. These segments were rarely spared in patients with previous cholecystectomy. Other sites of focal sparing were observed with the same frequency in the two groups. We conclude that focal sparing occurs frequently in patients with liver steatosis, especially in segments 4 and 5. When the gallbladder is absent, areas of focal sparing are less frequent, and they rarely involve segments 4 and 5. This suggests that the blood supply of the gallbladder plays a role in the distribution of the fat in the adjacent liver. Focal sparing might serve as an additional sign in the diagnosis of steatosis of the liver, especially in patients with an intact gallbladder.

Adolescent↗
PubMed1994

Characterization of surface binding sites for cyclophilin B on a human tumor T-cell line.

Cyclophilin B (CyPB) is a cyclosporin-binding protein, known to be located mainly within the endoplasmic reticulum vesicles. Its previous characterization in human milk implies that the protein may be released from the secretory pathway and recovered in biological fluids. In an attempt to understand the role of the extracellular CyPB, we have investigated the binding capacity of the protein to cells derived from human T- and B-lymphocytes. We present here evidence that CyPB binds to T-lymphocytes and that the binding to the Jurkat T-cell surface is specific, saturable, and reversible. The dissociation constant Kd was 12 nM, and the number of binding sites was estimated to 35,000/cell. We report that the surface-bound CyPB was internalized at 37 degrees C and subsequently degraded in the cell. We also show that the immunosuppressive drug cyclosporin A does not inhibit the surface binding of CyPB, and does not interfere with internalization of the protein. These results support the hypothesis that the selective action of the immunosuppressive drug results in part from its interaction with the extracellular form of CyPB.

Amino Acid Isomerases↗