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Biomedical subjects

J P Richard

Publications and source records attributed to J P Richard.

At least 19 recordsLinked to original sources
PubMed1992

[The intravascular transfer of glycine during percutaneous kidney surgery].

Transurethral prostatic resection using a 1.5% glycine solution causes a well known clinical and metabolic syndrome called TURP-syndrome. Recent development of percutaneous renal surgery is responsible of several similar accidents. In a prospective study of 150 patients (mean age: 35 +/- 10) subjected to a percutaneous nephrolithotomy, the natremia and the amino acid content of the plasma were measured preoperatively and immediately postoperatively by chromatography. The study shows that there is a post-nephrolithotomy syndrome in two per cent. This syndrome contains a hemodilution with hyponatremia and reabsorption of irrigation fluid. Glycolemia, serinemia and threoninemia increase significantly. These modifications have a good correlation between them except for the natremia. Variability of results in this study and in the literature is explained by difficulty and duration of surgery, volume of glycol used, increasing intrarenal pressures and sudden opening of vessels peroperatively. The gravity of post-nephrolithotomy syndrome requires to change the irrigate solute and use normal saline solution when it is possible.

Adolescent↗
PubMed1991

Kinetic parameters for the elimination reaction catalyzed by triosephosphate isomerase and an estimation of the reaction's physiological significance.

Kinetic parameters for triosephosphate isomerase catalysis of the elimination reaction of an equilibrium mixture of dihydroxyacetone phosphate (DHAP) and D-glyceraldehyde-3-phosphate (DGAP) to form methylglyoxal and phosphate ion are reported for the enzyme from rabbit muscle. Pseudo-first-order rate constants for the disappearance of substrate (kelim) were determined for reactions at [Enzyme] much greater than [Substrate]. The second-order rate constant kEnz = 10.1 M-1 s-1 was determined from a plot of kelim against enzyme concentration. The kinetic parameters, determined from a steady-state kinetic analysis at [Substrate] much greater than [Enzyme], are kcat = 0.011 s-1, Km = 0.76 mM, and kcat/Km = 14 M-1 s-1. The estimated rate-constant ratio for partitioning of the enzyme-bound intermediate between protonation at carbon 2 and elimination, 1,000,000, is much larger than the ratio of 6.5 determined for the reaction of the enediolate phosphate in a loose complex with quinuclidinonium cation, a small buffer catalyst. There is a 10(5)-10(8)-fold decrease in the rate constant for the elimination reaction of the enediolate phosphate when this species binds to triosephosphate isomerase. The kinetic parameters for the elimination reaction catalyzed by the native triosephosphate isomerase and for the reaction catalyzed by a mutant form of the enzyme, which is missing a segment that forms hydrogen bonds with the phosphate group of substrate [Pompliano, D. L., Peyman, A., & Knowles, J. R. (1990) Biochemistry 29, 3186-3194] are similar.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1986

[Interaction between electrocautery and a pacemaker].

Following a new case of inhibition of a sentinel pacemaker by the cutting current of an electrocoagulator during endoscopic urologic surgery, the mechanism of this complication is recalled. The non-selectivity of the pacemaker detector circuit is responsible for interpreting the electrical disturbances due to the electrocoagulator as cardiac activity. The problems seen with other types of stimulators are discussed, especially programmable stimulation where the use of a magnet can lead to variations in the stimulator frequency. The stimulating wire can also be responsible for accidents, such as myocardial burns, and rhythm disturbances. The safety rules for the use of the electrocoagulator in patients with a non programmable sentinel pacemaker.

Aged↗
PubMed1979

Chiral [18O]phosphorothioates. The stereochemical course of thiophosphoryl group transfer catalyzed by nucleoside phosphotransferase.

Nucleoside phosphotransferase from barley seedlings was used to catalyze the equilibration of adenosine-5'-[18O]phosphorothioate having the S configuration at phosphorus with [adenine-8-14C]adenosine to produce [adenine-8-14C]adenosine-5'-[18O]phosphorothioate and adenosine. The configuration of the chiral phosphorus in adenosine-5'-[18O]phosphorothioate which was used as the donor substrate was then compared with that of the [adenine-8-14C]adenosine-5'-[18O]phosphorothioate isolated from the reaction mixture. They were found to be the same, showing that the reaction proceeds with 99.7% retention of configuration of the [18O]phosphorothioate. This is interpreted to be indicative of the involvement of a thiophosphoryl-enzyme intermediate in the nucleoside phosphotransferase reaction. The synthesis of adenosine-5'-[18O]phosphorothioate having the R and S configurations at the phosphorus atoms is described.

Adenosine Monophosphate↗
PubMed1978

[Calcifying and non-calcifying chronic pancreatitis. A statistical study (author's transl)].

A statistical study aimed at the determination of any possible differences between calcifying and non-calcifying chronic pancreatitis. It would seem that whilst there are differences from a histopathological and biological standpoint, these differences disappear completely as far as postoperative course is concerned. Curiously enough, the long term prognosis was the same regardless of the type of pancreatitis.

Chronic Disease↗
PubMed1978

[Analytical study and processing of information from a primary intervention report].

Analytical study of treatment of information from a primary intervention by the S.A.M.U. were brought about with the aim of performing a "statistical" study of enumeration of the various possibilities, using three "standard" programmes. After exploitation of the statistical data, the card index is stocked on conventional magnetic tape and verified by different parameters permitting its identification. In addition, the concatenation of different card indices is easy to obtain, which makes it possible to carry out research into all existing file cards regardless of the month or year.

Electronic Data Processing↗
PubMed1978

[Study and identification of adulteration of citrus fruit juices].

UNLABELLED: Various types of adulterations. Definition and method of determination. Case of fraud by standardization. Definition and problems. Specific problems of these types of frauds. Qualitative definition. 1. Automatic methods of classification: --ascending hierarchical classification; --analysis of correspondances; --analysis of "composantes principales". 2. RESULTS: Classification of juices according to the main types of fraud (watering, sugaring, acidification, comminuted intensification). 3. Towards a quantitative solution. Conclusion. Interest of the method, possibilities and limits, further possible uses.

Beverages↗
PubMed1975

[The setting up of a computer system for records of first entries at the emergency medical assistance service in Montpellier].

The setting up of a computing device to exploit the files of first transports at the MONTPELLIER SAMU was started essentially in order to constitute a document both accurate and of easy access, able to memorize the physical and mental behaviour of a patient in a transient state. The results thus obtained include: 1 -- An analytical study with a part devoted to general data such as the number of injured people or of patients, the number of calls from various sources, the means of intervention etc. and a more specific part dealing with type of accident the determination of the traumatic impacts, the first therapy etc.; 2 -- A synthetical study that constitutes the second phase of the dealing with information thanks to the drawing up of graphs indicating the number of calls per accident according to the time, the age, the number of serious cases etc.

Computers↗
PubMedDate not supplied

[Direct approach for bypass of the distal deep femoral artery. The supra mediocrural route].

The medio-femoral route permits a simple, direct approach to the distal part of the profunda femoris artery outside Scarpas triangle, i.e. below the first perforating artery. The quadriceps femoris and sartorius muscles are separated. This segment may reach the lower part of the popliteal artery through various collaterals supplying the muscle and nerve arteries and, hence, the leg. In selected cases with severe ischemia and absent femoral pulse, a by-pass operation carried out at this level permitted one to obtain a satisfactory arterial blood supply to the leg and foot. Used in only three patients, with a follow-up of several months, we cannot yet draw final conclusions, but the quality of the early results is evidence for the interest of the method.

Aged↗