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Biomedical subjects

A Kocher

Publications and source records attributed to A Kocher.

34 records · Page 2Linked to original sources
PubMed1999

Memantine for prevention of spinal cord injury in a rabbit model.

BACKGROUND: This study was conducted to investigate the effect of memantine, a noncompetitive N-methyl-d-aspartate receptor antagonist, on the neurologic outcome of spinal cord ischemia after aortic occlusion. MATERIALS AND METHODS: New Zealand White rabbits were anesthetized and spinal cord ischemia was induced for 40 minutes by infrarenal aortic occlusion. Animals were randomly allocated to 3 groups. Group 1 (n = 8, control) received no pharmacologic intervention, group 2 (n = 8) received intra-aortic memantine infusion (20 mg/kg) after aortic crossclamping, and group 3 (n = 8) was treated with systemic memantine infusion (20 mg/kg) 45 minutes before aortic occlusion. Neurologic status was scored by the Tarlov system (in which 4 is normal and 0 is paraplegia) at 12, 24, 36, and 48 hours after the operation. Lumbar spinal root stimulation potentials and motor evoked potentials from lower limb muscles were monitored before, during, and after the operation. After the animals were killed, the spinal cords were studied histopathologically. RESULTS: All potentials disappeared shortly after aortic crossclamping. They returned earlier in both memantine-treated groups than in the placebo group. Histologic examination of spinal cords revealed a few abnormal motor neurons in memantine-treated rabbits but found extensive injury in the control group. At 12 hours the median Tarlov scores were 0 in the control group (group 1), 2 in the intra-aortic memantine group (group 2, P =.001 versus control), and 3 in the systemic group (group 3, P =.0002 versus control). At 24 hours median Tarlov scores were 0, 2.5 (P =.0002), and 4 (P =. 0002), respectively. Finally, at both 36 and 48 hours median Tarlov scores were 0, 3 (P =.0006), and 4 (P =.0002), respectively. CONCLUSION: Memantine significantly reduced neurologic injury related to spinal cord ischemia and reperfusion after aortic occlusion.

Animals↗
PubMed1999

Alterations in the number of circulating leucocytes, phenotype of monocyte and cytokine production in patients undergoing cardiothoracic surgery.

Changes in the differential blood cell count, monocyte phenotype and the cytokine plasma levels in a group of seven patients with cardiac surgery/cardiopulmonary bypass (CPB) and nine patients with thoracic surgery/without CPB, both receiving identical opioid-based anaesthetic technique, were assessed. A significant reduction in the number of circulating lymphocytes and monocytes was observed after anaesthesia and surgery. Interestingly, at the end of surgery as well as 1 day post-surgery a marked increase in the number of granulocytes was noted. General anaesthesia and surgery caused a significant reduction of HLA-DR and CD11c/CD18 molecules, starting immediately after induction of anaesthesia, and an increase of CD64 at day 1 after anaesthesia. The use of a CPB was followed by a significant reduction of CD32, CD16, CD54 and HLA-ABC antigens expression at the end of surgery. One day after surgery these parameters returned nearly to baseline values with the exception of CD54. A monocyte subpopulation, characterized by low CD14, high CD16 and HLA-DR expression (CD14+CD16+HLA-DR++) was found in both groups at each time point, and the percentage of this cell subset decreased from baseline to 24 h. The plasma concentrations of IL-6 and IL-10 increased considerably during CPB. No dynamic changes of IL-1 level due to surgery or CPB were found. We conclude that anaesthesia as well as the use of CPB induced profound alterations in the number of circulating leucocytes, and in the phenotype of monocyte and cytokine production.

Aged↗
PubMed1998

Operations on the thoracic aorta and hypothermic circulatory arrest: is aprotinin safe?

INTRODUCTION: The safety of aprotinin, especially when used with profound hypothermic circulatory arrest, is still a matter of intense debate despite its presumed salutary effects on blood loss. Many investigators have reported toxic renal effects of high-dose aprotinin in such patients, but no prospective, randomized study has been conducted. To assess the potential detrimental effect of aprotinin on renal function and its putative reduction of blood loss, 50 patients undergoing thoracic aortic operations with the use of profound hypothermic circulatory arrest were randomly assigned to receive either low-dose aprotinin (1 x 10(6) kallikrein activation units) or placebo. METHODS: The specific renal tubular markers beta-2-microglobulin and beta-N-acetyl-D-glucosaminidase, as well as serum creatinine and blood urea nitrogen, creatinine clearance, sodium excretion, and potassium excretion, were measured to evaluate renal function preoperatively, immediately after the procedure, and 24 hours and 48 hours later. RESULTS: No statistically significant difference was found in any measured renal parameter between the two groups (analysis of variance). Renal dysfunction, defined as an elevation of serum creatinine early postoperatively (> or = 1.5 times the preoperative value), occurred in two patients who received aprotinin and in one patient in the control group. Temporary dialysis (hemodialysis or continuous venovenous hemofiltration) was needed in two patients in the aprotinin group versus one in the control group. Furthermore, patients treated with aprotinin had significantly less total postoperative blood loss (718 +/- 340 ml vs 920 +/- 387 ml, p = 0.04). The aprotinin recipients also had a significantly lower transfusion requirement (p < 0.05). CONCLUSION: This controlled trial of low-dose aprotinin in patients undergoing thoracic aortic operations using profound hypothermic circulatory arrest demonstrated no detectable deleterious effects on renal function; moreover, the use of aprotinin was associated with significantly lower need for transfusion.

Aged↗
PubMed1997

Simultaneous heart and kidney transplantation as treatment for end-stage heart and kidney failure.

BACKGROUND: The aim of the present analysis was to define the role of simultaneous heart and kidney transplantation (HNTX) using organs from the same donor by evaluation of clinical strategy and achieved outcome compared with a reference group of concurrently single heart transplant (HTX) and kidney transplant (NTX) recipients. Compared with other organ combinations (pancreas-kidney, heart-lung), HNTX has been performed infrequently and is reported mainly as case records in the literature. Because of expansion of recipient selection criteria for HTX and NTX, the number of patients requiring simultaneous replacement of both organs is increasing. METHODS: Six HNTX recipients, three of them suffering from long-standing type I diabetes, received transplants between September 1990 and March 1996 and were analyzed in terms of clinical and immunological demographics and outcome. They were compared with 379 HTX and 769 NTX recipients operated upon within this period. RESULTS: Survival for HNTX is 100% with a mean follow-up of 32.7+/-21.1 months. Cold ischemic time of the kidney was significantly shorter for HNTX than for NTX (6.5+/-1.0 hr vs. 22.1+/-6.8 hr, P<0.005). Although HNTX patients received HLA-unmatched grafts, no rejection of the kidney has been observed to date. There was no difference for rejection of the heart in HNTX compared to HTX recipients. CONCLUSIONS: Satisfying results are obtained by HNTX and justify the use of two organs for one recipient. The favorable immunological behavior of the kidney despite use of HLA-unmatched grafts is most probably explained by higher immunosuppression and short cold ischemic time, although a combination effect cannot be excluded.

Adult↗
PubMed1996

The influence of lung volume reduction surgery on ventilatory mechanics in patients suffering from severe chronic obstructive pulmonary disease.

Recently, lung volume reduction [LVR] removal of about 20% of lung volume), has been performed to treat severe emphysema. Little is known, however, about the mechanism and time course of functional improvement, and the reasons that such patients can be tracheally extubated very early. Therefore, we studied changes in ventilatory mechanics in 12 patients after LVR. Measurements of work of breathing (WOB), intrinsic positive end-expiratory pressure (PEEPi), dynamic compliance (Cdyn), and mean airway resistance (Rawm) were performed the day before surgery, early postoperatively, and 1 and 3 mo after surgery. All measurements were performed on tracheally extubated patients, simultaneously assessing esophageal pressure via esophageal balloon catheter and air flow via tightly adjusted mask. Standard spirometry was assessed pre-operatively and 1 and 3 mo postoperatively. The patients presented with forced expiratory volume in 1 s (FEV1), of 670 +/- 50 mL and pathological values of WOB and PEEPi. All patients were successfully tracheally extubated within 5 h postoperatively. Immediately thereafter, a marked and sustained decrease in WOB, PEEPi, and Rawm was noted, as well as an increase in Cdyn. Ventilatory mechanics improved immediately after LVR, probably due to decompression of lung tissue, thereby enabling successful tracheal extubation.

Adult↗
PubMed1995

[Strategies in management of heart transplantation candidates with tachycardic ventricular arrhythmia anamnesis].

We followed up 73 consecutive patients with a history of syncopal ventricular tachyarrhythmias on the waiting list for a heart transplant between 1st March 1992 and 15th September 1994 with the aim of evaluating the impact of implantable cardioverter defibrillator (ICD) on survival. On registration 60 patients were considered fit enough to be ambulant whilst awaiting transplantation. 30 were given ICD therapy (group 1) and 30 were not (group 2). 13 patients required inpatient supervision for ventricular arrhythmias whilst awaiting transplantation, but received no ICD therapy (group 3). The 13 in-patients were in a worse clinical state (NYHA) than the 30 out-patients not given ICD (p < 0.05). With respect to all other clinical and hemodynamic characteristics all groups were comparable. Waiting time for transplantation was also comparable in all groups (n.s., log-rank method). ICD therapy resulted in a significant improvement of survival in these high-risk patients prior to transplantation. Only 1 out of the 30 ICD patients (group 2) and 5 out of the 13 in-patients (group 3) (p < 0.05 log-rank method). During the waiting time group 3 patients were hospitalised longest (p < 0.05), but there was a clear trend that also ICD patients had to be hospitalised to an increased extent (n.s.). Cox multivariate regression analysis of this study population showed that the cardiac index (p = 0.001) and lack of ICD therapy (p = 0.035) were the only independent significant predictors of mortality on the waiting list. ICD therapy had no influence on mortality after transplantation (n.s. log-rank method).

Adult↗