Biomedical subjects

A Jeanjacquot

Publications and source records attributed to A Jeanjacquot.

5 recordsLinked to original sources

PubMed1999

Optimization of the kinetics of cooling of kidneys: a pig model.

We determined the kinetics of cooling in multiple organ procurement for the kidney in a pig model. A biometric analysis by regression enables us to define the factors which influence the rate of temperature decrease: weight of the donor, average rate of perfusion and difference of temperature between the rectal temperature and the temperature of the perfusion solution at initiation of cooling. The description of the temperature as a function of time follows an exponential model of the type T(t) = T0. e(dt) where d is the rate of decrease. The rate of decrease varies according to the above factors. The cellular viability ratio (CVR), was correlated to the rate of cooling. The mean CVR was 91% (SD 4.95) when the rate of cooling was more than 1 degrees C/min. This was compared to 75% (SD 11.17) when the rate was less than 1 degrees C/min (p = 0.023). Our experience leads us to believe that the average cooling rate is frequently too low (<1 degrees C/min). This model can be used to predict and control the kinetics of cooling and may help to define the best way of cooling for future xenotransplantation.

Animals↗

PubMed1996

Kinetics of cellular viability in warm versus cold ischemia conditions of kidney preservation. A biometric study.

We have determined the kinetics of the cellular viability ratio (CVR), defined as the number of living cells over the total cell count, in pig kidneys using propidium iodide and fluorescein diacetate staining, as a function of time and preservation conditions. The kidneys were preserved in warm or cold ischemia in order to mimic the conditions of transplantation from non-heart-beating donors or multiple removal with optimal preservation of the graft, respectively. To determine the CVR, the cells were obtained by a fine-needle aspiration biopsy, which minimizes the damage to the graft. A biometric analysis by regression enabled the determination of the time dependence for warm ischemia (CVR(t) = 80.0 x e(-0.733-t)(+2.7/-0.36)) and for cold ischemia (CVR(t) = 80.0 x e(-0.022-t)(+1.57/-0.64)) with a confidence interval of 95%. These master curves allow us to predict, under the described conditions, the CVR after a given ischemia time. The half-life of the cells can be deduced from the time-dependent CVR(t), and is 0.64 hr (38 min) for warm ischemia and 21.4 hr for cold ischemia. Further, the CVR for a given kidney can be used to assess its condition at removal: if the CVR is below 48% at 2 hr after removal, one can conclude that the organ has suffered a period of warm ischemia.

Animals↗

PubMed1990

Experimental porcine orthotopic liver transplantation: a training protocol for transplantation in humans.

The authors suggest that, prior to human liver transplantations, exhaustive training be undertaken on an animal model in order to acquire the expertise required for this delicate procedure. The pig has considerable anatomic similarities to man, as well as a comparable physiological and hemodynamic sensitivity, and has been used as a model by our experimental team to perfect our clinical liver transplantation technique. In particular, a surgical model representing the adult donor/child recipient situation has been developed. Anesthesia, extracorporeal bypass procedure and the full surgical protocol are described. This operative protocol was elaborated to mimic as closely as possible the clinical situation. Our model also allowed us to undertake several relevant physiological and pharmacological studies during the transplantation procedure.

Animals↗

PubMed1987

A new abdominal drain for overflowing lavage in instances of severe pancreatitis with persistent peritoneal contamination.

Eight patients with severe acute necrotizing pancreatitis had a new removable drainage device applied which allowed for massive lavage drainage with water tightness and easy repeated abdominal and retroperitoneal revisions. The lavage clears the enzymes and the toxic products that continuously soil the abdomen and affect all other systems. Simultaneously, it acts as a peritoneal dialysis. There were no complications and the 50 per cent survival rate at three months compares favorably with that of corresponding instances in another study (p less than 0.02).

Abdomen↗

PubMed1984

Arthropump with peristaltic effect and pulsatile flow.

This paper describes a pump of novel design, with peristaltic effect and pulsatile flow. Special features are the facility for occlusive or non-occlusive pumping, and the absence of moving parts in the flow section. A compressible drive medium allows 'individual' transport of big particles in the pumped fluid. Pumping of a relatively high proportion of solids in liquid is possible. This pump is suitable for handling living structures in cell and tissue separating systems. Pumping of fluids with increased viscosity and abrasives in liquid is also feasible.

Biomedical Engineering↗