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Biomedical subjects

A Adam

Publications and source records attributed to A Adam.

At least 199 records · Page 11Linked to original sources
PubMed1990

The use of prostatic stents in patients with urinary retention who are unfit for surgery. An interim report.

Under local anaesthesia, 19 patients (18 with acute and 1 with chronic urinary retention) underwent insertion of an expandable stainless steel tubular "stent" into their prostatic urethra under fluoroscopic control. All were considered to be at major risk from prostatic surgery. The 18 patients with acute retention voided spontaneously following the initial stent procedure, but the patient with chronic retention required a period of suprapubic catheterisation. Following the endoscopic insertion of an additional stent this patient also voided spontaneously. During a follow-up period of 3 to 7 months (mean 4), 4 patients were lost to follow-up. The remaining 15 patients all void spontaneously. Recurrent asymptomatic urinary tract infections were seen in all but 1 patient initially, but none of those who were followed up for over 5 months had evidence of infection. Although the follow-up period is limited, the results to date demonstrate that the insertion of an expandable prostatic stent is a safe and reliable method of treating acute urinary retention in patients unfit for surgery. Further follow-up is required to assess long-term safety and to exclude late complications.

Aged↗
PubMed1990

Kinins and peritoneal exudates induced by carrageenin and zymosan in rats.

1. Kinins were measured by a radioimmunoassay in the inflammatory exudates induced by carrageenin or zymosan in the peritoneal cavity of normal Wistar rats and of kininogen-deficient Brown Norway rats. 2. After administration of carrageenin to normal rats, levels of immunoreactive kinins showed a single peak during the first two hours and then decreased. The presence of kinins preceded and accompanied the exudation of 125I-labelled albumin. Kinins were identified as bradykinin by chromatography. 3. Captopril, an inhibitor of kininase 2, increased the level of kinins and the volume of the exudates after carrageenin treatment. In Brown Norway rats, the volume of the exudates was small and contained little or undetectable amounts of immunoreactive kinins. 4. During zymosan-induced peritonitis, the exudates were devoid of immunoreactive kinins in both species. The volume of the exudates was larger in kininogen-deficient rats than in normal rats. 5. We conclude that in rats, the kinin system is a major factor responsible for the development of the inflammatory reactions induced by carrageenin, but is not involved in the reactions induced by zymosan.

Animals↗
PubMed1990

Thermolabile hexosaminidase (Hex) B: diverse frequencies among Jewish communities and implication for screening of sera for Hex A deficiencies.

Twenty unrelated people with thermolabile beta-hexosaminidase (Hex) B were identified in random samples of 41,561 adult Israeli Jews whose sera were screened for Hex A levels. Eighteen of them originated from contiguous Middle Eastern countries (n = 1,337) and only 2 were Ashkenazi Jews (n = 38,388). None was found among the screened Moroccan Jews (n = 1,524). The commonly used screening test for detection of Tay-Sachs disease (TSD) carriers is the serum Hex heat inactivation method (HIM), which is based on the assumption that Hex A is the only thermolabile component of Hex; However, in the presence of thermolabile Hex B, HIM could lead to false-negative results. Since TSD is very rare among Mideastern Jews while thermolabile Hex B is very rare among Ashkenazi and Moroccan Jews, it is concluded that at present there is almost no risk of such false-negative results. In order to further reduce this risk it is recommended that screening of people of Mideastern or mixed ancestry be done with HIM in leukocytes rather than in serum or with the specific substrate for Hex A in serum.

Chromatography, Ion Exchange↗
PubMed1990

A novel lung slice system with compromised antioxidant defenses.

In order to facilitate the study of oxidative stress in lung tissue, rat lung slices with impaired antioxidant defenses were prepared and used. Incubation of lung slices with the antineoplastic agent 1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU) (100 microM) in an amino acid-rich medium for 45 min produced a near-maximal (approximately 85%), irreversible inhibition of glutathione reductase, accompanied by only a modest (approximately 15%) decrease in pulmonary nonprotein sulfhydryls (NPSH) and no alteration in intracellular ATP, NADP+, and NADPH levels. The amounts of NADP(H), ATP, and NPSH were stable over a 4-hr incubation period following the removal from BCNU. The viability of the system was further evaluated by measuring the rate of evolution of 14CO2 from D-[14C(U)]-glucose. The rates of evolution were almost identical in the compromised system when compared with control slices over a 4-hr time period. By using slices with compromised oxidative defenses, preliminary results have been obtained with paraquat, nitrofurantoin, and 2,3-dimethoxy-1,4-naphthoquinone.

Adenosine Triphosphate↗
PubMed1990

An assessment of the role of redox cycling in mediating the toxicity of paraquat and nitrofurantoin.

The abilities of paraquat, diquat, and nitrofurantoin to undergo cyclic oxidation and reduction with rat microsomal systems have been assessed and compared to that of the potent redox cycler, menadione. Diquat and menadione were found to be potent redox cyclers with comparable abilities to elicit a nonstoichiometric increase in both the consumption of O2 and the oxidation of NADPH, compared to the amounts of substrate added. In contrast, paraquat and nitrofurantoin redox cycled poorly, being an order of magnitude less potent than either diquat or menadione. This was reflected in kinetic studies using lung and liver microsomes, which showed that NADPH-cytochrome P-450 reductase had a lower affinity (Km) for paraquat and nitrofurantoin than for menadione and diquat, although values of Vmax were comparable for all the substrates except nitrofurantoin, which was lower. In order to assess redox cycling of the substrates in an intact lung system, the O2 consumption of rat lung slices was measured in the presence of all four compounds. A small increase in lung slice O2 uptake was observed with paraquat (10(-5) M) in the first 2.5 hr of incubation, possibly because of redox cycling of a high intracellular concentration of paraquat resulting from active accumulation into target cells. This stimulation in O2 uptake was no longer observed when slices were incubated for a longer period or with higher paraquat concentrations (10(-4) M), possibly because of toxic effects in target cells. High concentrations of diquat (10(-5) M) had no effect on O2 consumption of lung slices.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1990

Biliary endoprosthesis dysfunction in patients with malignant hilar tumors: successful treatment by percutaneous replacement of the stent.

Symptoms caused by malignant hilar bile duct tumors are often palliated by the insertion of a percutaneous biliary endoprosthesis. However, these often occlude early and may be difficult to replace. We have reviewed our experience with percutaneous replacement of endoprostheses in 17 patients with 31 episodes of stent dysfunction. The stent was changed successfully in 30 of the 31 attempts. The average durations of initial and subsequent stent patencies were 28 and 20 weeks, respectively. Significant acute complications occurred in three patients, one of whom had a perihepatic abscess and two of whom had septicemia. Two patients died within 30 days of their last stent change. The one patient in whom attempted insertion of a new stent was unsuccessful had to remain on continuous external catheter drainage. The occluded or migrated endoprosthesis was successfully removed either percutaneously (55%) or endoscopically (26%) in 25 of the 31 cases. Successful removal of the stent and reinsertion after blockage or migration is possible in most patients. Our experience suggests that patients with malignant obstruction of the bile duct should not be refused an indwelling endoprosthesis just because of the frequent occurrence of early occlusion of the stent.

Adenoma, Bile Duct↗
PubMed1990

[Integrated pedagogic-therapeutic process in inpatient group therapy work with behaviorally disordered adolescents].

This article describes a group project involving educational-therapeutic work on an inpatient basis with behaviourally disturbed adolescents. It shows how the integration of education and therapy, which is considered so necessary at the inpatient level, is achieved in group therapy and it describes as well the institutional framework within which the group project is carried out, as well as the type of practical experience with behaviourally disturbed adolescents which preceded the development and application of the group therapy work. The initial conditions, aims and the development process of the group therapy which took place over a period of two years are presented and four development phases are identified and explained. The article ends with observations concerning the self-evaluation of the group leaders, the general experience gained in the setting up of educational-therapeutic group work with behaviourally disturbed adolescents and a review of the preliminary results of the group project.

Adolescent↗
PubMed1990

Patterns of serum alkaline phosphatase activity in unilateral hepatic duct obstruction: a clinical and experimental study.

The levels of serum alkaline phosphatase (ALP) were measured in eight patients with bile duct obstruction limited to one lobe of the liver. Although an initial rise of enzyme concentration was documented in every patient, unrelieved biliary obstruction was associated with a gradual return of ALP to normal values. The return to normal levels coincided with the development of atrophy of that part of the liver deprived of its bile drainage. An animal model of experimental selective biliary obstruction supported a causative association between reduction of hepatocyte mass and a decrease in ALP activity. It appears that normal serum ALP levels can be expected with advanced obstructive biliary disease. Suspected lobar or segmental duct obstruction warrants investigation--even if liver function tests are normal.

Adult↗
PubMed1989

Analysis of albuterol in human plasma based on immunoaffinity chromatographic clean-up combined with high-performance liquid chromatography with fluorimetric detection.

A method combining immunoaffinity chromatography with high-performance liquid chromatography was developed for the determination of albuterol in human plasma. The immunoaffinity chromatography, based on the specific interaction of albuterol with the immobilized antibody raised against it, was used as a clean-up step. Albuterol eluted from this immunochemical solid-phase clean-up step was analysed by reversed-phase high-performance liquid chromatography with fluorimetric detection. The performance of the assay was validated on six normal volunteers after a 4-mg oral dose of albuterol, which gave a peak plasma concentration in the range 6.67-15.31 ng/ml at 3-4 h after the dose. Plasma levels (0.79-1.56 ng/ml) of albuterol could be detected up to 24 h after the dose.

Albuterol↗
PubMed1989

Quantification of rat T-kininogen using immunological methods. Application to inflammatory processes.

Antibodies raised in rabbits against rat T-kininogen (alpha 1-cysteine proteinase inhibitor) were used to develop a radioimmunoassay and a nephelometric quantification for T-kininogen. These assays were specific and analytically reliable. We also described a radioimmunoassay for kinin measurement. These immunological methods have been used to study the behaviour of T-kininogen during inflammatory processes and specify the two properties of this kind of kininogen: its inhibitory capacity towards cysteine proteinases and its activity as precursor of T-kinin. Control plasma level of T-kininogen in male rats was lower than that of female rats. The maximum level was observed in plasma, liver, kidney and uterus of female rats during metestrus. After turpentine injection, T-kininogen level increased not only in plasma but also in liver and kidney. In carrageenan-induced peritoneal exudates, we found a large accumulation of T-kininogen and of immunoreactive kinins, these latter being identified by HPLC as bradykinin.

Animals↗