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P Mares

Publications and source records attributed to P Mares.

At least 73 records · Page 4Linked to original sources
PubMed2000

Does status epilepticus influence the motor development of immature rats?

PURPOSE: To study the effect of severe status epilepticus (SE) on the motor development of rats. METHODS: SE was induced in 12-day-old rats (P12 group) and 25-day-old rats (P25 group) using the lithium-pilocarpine model. Seizures were interrupted after 2 hours by paraldehyde with an intraperitoneal dose of 0.3 or 0.6 mL/kg, respectively. Starting 3 days after SE, all animals were repeatedly exposed to a battery of motor and behavioral tests, including the bar-holding test, rotarod test, and open field test. RESULTS: In P12 animals, motor impairment occurred 2 months after SE, when significantly worse performance in the rotarod test was found. No difference between controls and experimental rats was found in any other test used. In contrast, P25 animals were significantly poorer in the bar-holding test from postnatal day 34 until adulthood. In open field study, P25 rats were found to be hyperactive during the whole period of testing, whereas P12 animals exhibited an initial period of hypoactivity (in the first test) that was replaced by hyperactivity that lasted until 2 months of age. In the last test performed at the age of 98 days, experimental P12 animals were again less active than age-matched controls. CONCLUSIONS: Animals of both age groups exhibited permanent changes of motor performance; however, both the pattern and the time course of these changes was related to age when SE was elicited.

Age Factors↗
PubMed2000

Anticonvulsant action of topiramate against motor seizures in developing rats.

PURPOSE: To study the anticonvulsant action of topiramate (TPM) in developing rats. METHODS: Motor seizures were elicited by administering pentylenetetrazol (100 mg/kg subcutaneously) in five age groups of Wistar rats (7, 12, 18, 25, and 90 days old). TPM was administered intraperitoneally in doses from 10 to 640 mg/kg 2 hours before pentylenetetrazol. The time course of TPM action was studied in 12- and 25-day-old rats up to 24 hours after the 160-mg/kg dose, and the incidence and pattern of seizures were evaluated. RESULTS: TPM did not influence minimal seizures (clonus of forelimb and head muscles with preserved righting ability). Generalized tonic-clonic seizures, however, were reliably changed at all developmental stages studied. The tonic phase was suppressed so that the majority of animals exhibited generalized clonic seizures (with a loss of righting reflexes). In addition, the incidence of generalized seizures was decreased after the 20-, 40-, and 80-mg/kg doses in the 7-day-old rat pups. The specific suppression of the tonic phase of generalized seizures was observed up to 12 hours in the 12-day-old rat pups. The same result was obtained over 6 hours after TPM administration in the 25-day-old animals, and with longer intervals the incidence of generalized seizures decreased in this age group. CONCLUSIONS: TPM exhibits stable anticonvulsant action against the tonic phase of generalized tonic-clonic seizures throughout development. In addition, it suppresses all phases of generalized seizures in 7-day-old rats. The anticonvulsant action of TPM lasted longer in 25-day-old than in 12-day-old rats. The two actions of TPM might be ascribed to two different mechanisms of action.

Age Factors↗
PubMed2000

[Static and dynamic MRI of the normal and pathological female pelvic floor].

Static and dynamic MRI of the female pelvic floor is a new application of this technology. The capability of MRI to assess cavities and muscles on the same exploration is an important improvement. The authors describe successively: MRI is nowadays a decisive tool in the preoperative work-up of pelvic floor dysfunctions.

Female↗
PubMed1999

Changes in NADPH-diaphorase positivity induced by status epilepticus in allocortical structures of the immature rat brain.

The distribution and time course of changes of nicotinamide adenine dinucleotide phosphate diaphorase (NADPH-d) positivity were studied in immature rats (12 and 25 days old) surviving motor status epilepticus (SE) induced by a high dose of pilocarpine. Motor SE characterized by continuous convulsions was interrupted after 2 h by an injection of clonazepam (0.5 mg/kg or 1 mg/kg in 12- and 25-day-old rats, respectively) in order to reduce mortality. Correlation between electroencephalographic and behavioral seizure activity was confirmed using animals with electrodes implanted bilaterally in the hippocampus and sensorimotor cortex. Brains were examined 2, 6, 13, and 21 days after motor SE using NADPH-diaphorase histochemistry. Two types of changes were found in both age groups: (a) decrease of NADPH-d positivity occurred in both neuropil and cell bodies in piriform, periamygdalar, and entorhinal cortices; and (b) NADPH-d positivity was induced in the cell bodies in the hippocampal fields CA1/2, CA3, and dentate gyrus. These changes were more intense in animals surviving SE at postnatal day 25 than in younger age group, and they peaked 2 days after SE. The changes observed after SE disappeared quickly in 12-day-old rat pups, where only moderate changes could be observed in piriform, periamygdalar, and entorhinal cortices 6 days after SE, whereas the changes in the histochemical positivity persisted in older animals even 21 days after SE.

Aging↗
PubMed1999

The benzodiazepine receptor partial agonist Ro 19-8022 suppresses generalized seizures without impairing motor functions in developing rats.

The action of a partial benzodiazepine receptor agonist Ro 19-8022 [(R)-1-[(10-chloro-4-oxo-3-phenyl-4H-benzo[a]quinolizin-1-yl)carbo nyl] -2-pyrrolidine-methanol] in doses from 0.01 to 150 mg/kg was studied using motor seizures induced by pentylenetetrazol (PTZ) in rats 7, 12, 18, 25 and 90 days old. Generalized tonic-clonic seizures were suppressed in all age groups, the three youngest groups being more sensitive than older animals. The highest dose of Ro 19-8022 did not exhibit anticonvulsant action in the 25-day-old rats. The other types of seizures (minimal clonic) induced by PTZ were suppressed by Ro 19-8022 only in 18-day-old and older rats in which PTZ reliably elicited these types of seizures. The doses of 50, 100 and 150 mg/kg were ineffective against minimal seizures. On the contrary, incidence of minimal seizures was significantly increased by Ro 19-8022 in 7-and 12-day-old rat pups. Motor performance of rat pups was not compromised by Ro 19-8022 (0.5 and 50 mg/kg) in contrast to the full agonist midazolam (1 and/or 2 mg/kg). The duration of anticonvulsant effects studied with a dose of 0.5 mg/kg was longer in 12-day-old than in adult rats. This dose of Ro 19-8022 resulted in a rebound proconvulsant effect 24 and 48 h after the administration in 12-day-old rats only. Ro 19-8022 exhibited an excellent anticonvulsant action especially against generalized tonic-clonic seizures; this action was lost with very high doses. It did not compromise the motor system, but in some tests motivation was probably lost.

Aging↗
PubMed1999

T4 lung tumors with infiltration of the thoracic aorta: is an operation reasonable?

BACKGROUND: Only anecdotal reports about the results of combined resection of T4 lung tumors infiltrating the thoracic aorta exist. METHODS: Seven patients (mean age, 57.5 years; range, 43 to 78 years) underwent a resection of the infiltrated segment of the thoracic aorta together with a left pneumonectomy (n = 6) or left upper lobectomy (n = 1). Five tumors were primary non-small cell lung carcinomas (T4N2 in 3 patients, T4N1 in 2), one was a metastasis of breast cancer, and one was rhabdomyosarcoma. RESULTS: No patient died perioperatively. The 2 patients with rhabdomyosarcoma and metastasis of breast cancer died 2 and 7 months postoperatively. Of the 5 patients with bronchial carcinoma, 3 died after 17, 26, and 27 months as a result of distant metastasis. Two patients are alive after 14 and 50 months without evidence of disease recurrence. One-year, 2-year, and 4-year survival rates for patients with bronchial carcinoma were 100%, 75%, and 25%, respectively. CONCLUSIONS: Combined resection of the lung and thoracic aorta can be performed with low morbidity and mortality when offered to highly selected patients. Adequate local control of tumor can be achieved for N1 and single-level N2 non-small cell lung carcinomas, but not for tumors with other histologies.

Adenocarcinoma↗
PubMed1999

Ventricular thrombus and subarachnoid bleeding during support with ventricular assist devices.

We report the case of a 23-year-old man with acute aortic valve insufficiency caused by endocarditis, who after emergency aortic valve replacement developed biventricular heart failure. The heart failure was treated with temporary assist devices. Subarachnoid bleeding and thrombus obstruction of the left ventricular outflow tract was detected. The postoperative course is presented with special emphasis on management of subarachnoid bleeding and the simultaneous use of anticoagulation necessary for ventricular assist devices.

Adult↗
PubMed1999

Initial experience with two sequential anterolateral thoracotomies for bilateral lung transplantation.

BACKGROUND: Bilateral transsternal thoracotomy (clamshell incision) is the standard approach used for bilateral sequential lung transplantation (BLTX). The morbidity of this large incision can be considerable. Two separate sequential anterolateral thoracotomies represent a less invasive approach. METHODS: The value of this approach was investigated in a prospective series of 13 consecutive patients with the underlying diagnosis of COPD or cystic fibrosis (group A). Results were compared to 8 consecutive patients with similar indications who had undergone BLTX via clamshell incision during the last year prior to this new technique (group B). RESULTS: No intraoperative complications occurred in either group. The difference between the cold ischemic time of the 1st and 2nd transplanted lung was comparable between the 2 groups (81 min+/-17 min in group A vs 79 min+/-14 min in group B, p = 0.783). Postoperative restriction was significantly less in the group operated through 2 separate thoracotomies, as proven by the vital capacity in the first spirometry performed during the 3rd postoperative week (VC group A 55%+/-16% predicted vs 41%+/-11% predicted in group B; p = 0.043). CONCLUSION: The bilateral sequential anterolateral thoracotomy represents a safe and less invasive approach for BLTX in patients with large chest volumes. It minimizes the operative trauma, improves postoperative functional recovery and prevents the potential spread of unilateral complications to the other pleural cavity.

Adult↗
PubMed1999

Behavioural effects of a subconvulsive dose of kainic acid in rats.

Kainic acid can induce a continuum of non-convulsive seizures characterised by epileptic automatisms and convulsive motor seizures depending on the dose. There are scarce data on the behavioural effects of low doses of kainate inducing only non-convulsive seizures. Therefore, we studied spontaneous behaviour of adult male rats using a method of positive habituation based on a detailed analysis of patterns and attention of animals to a stimulus object. Twenty-three animals were individually tested in the experimental arena on two consecutive days. Comparing the data from the first two exposures, a conspicuous habituation in all animals was observed. On experimental day 3, 12 rats received kainate (6 mg/kg intraperitoneally) and the remaining 11 animals received a physiological saline. After 1 h, animals were put into the arena with an object localised in the centre. It was found that both kainate and saline treated animals exhibited a significant increase in the total number of central area visits, and both the total and mean time spent in the vicinity of the object. However, the mean time spent was significantly shorter in kainate treated rats. Furthermore. kainate rats exhibited a significant decrease in rearing as compared with the controls. In addition, an epileptic automatism (wet dog shakes) was observed in seven out of 12 animals given kainate. The comparison of transition matrices between consecutive behavioural categories showed significant differences between the kainate and control groups. Our results demonstrate that a non-convulsive dose of kainate induced changes in the structure of spontaneous behaviour and impaired the processes related to maintenance of attention.

Animals↗
PubMed1999

Transient left ventricular failure following bilateral lung transplantation for pulmonary hypertension.

BACKGROUND: Bilateral lung transplantation is an established therapy for end-stage pulmonary hypertension. Its early postoperative outcome may be biased by various complications resulting in unexpected deterioration of the patient in terms of hemodynamics and blood gases. METHODS: We have reviewed the early postoperative course of patients who underwent bilateral lung transplantation for pulmonary hypertension at our institution and analyzed all available data, especially hemodynamic measurements, echocardiographic documentation and therapeutical strategies, in those cases where cardiac dysfunction was found to be responsible for clinical deterioration. RESULTS: Three out of 20 lung transplant recipients operated for pulmonary hypertension experienced severe respiratory insufficiency accompanied by hemodynamic decompensation during the first days after surgery. Clinical and laboratory findings together with results of echocardiography and pulmonary artery catheterism helped establish the diagnosis of left ventricular failure. This proved to be transitory, but the response to therapy (inotropic drugs, afterload reduction and eventually prostaglandins) was very variable. Adequately treated, this complication did not preclude the outcome of transplantation by itself. CONCLUSION: Left ventricular failure is a possible complication after lung transplantation for pulmonary hypertension. Echocardiography and pulmonary artery catheterism may be useful adjuvant diagnostic tools, beside routine physical examination, chest X-ray, and laboratory analysis. Therapy of this complication must be adapted individually and may be complex.

Adult↗
PubMed1999

Lung volume reduction surgery: preoperative functional predictors for postoperative outcome.

UNLABELLED: Approximately 20% of patients undergoing lung volume reduction surgery (LVRS) exhibit no functional improvement postoperatively. Therefore, we examined whether variables characterizing ventilatory mechanics before LVRS could serve as predictors for outcome. In 32 patients undergoing LVRS, lung function, dyspnea score, and ventilatory mechanics were assessed preoperatively and 3 mo after LVRS. Ventilatory mechanics were characterized by total resistive work of breathing (WOB), mean airway resistance (Rawm), and dynamic intrinsic positive end-expiratory pressure (PEEPi,dyn). Calculations of WOB, Rawm, and PEEPi,dyn were made from measurements of airflow, volume, and esophageal pressure. Preoperative PEEPi,dyn correlated well with the increase in forced expiratory volume percent predicted (r = 0.75; P < 0.0001) and the decrease in dyspnea score (r = -0.74; P < 0.0001) after LVRS. Rawm and WOB showed inferior correlation compared with PEEPi,dyn. The examination of distinct threshold values for WOB, Rawm, and PEEPi,dyn with respect to predicting improvement resulted in a sensitivity of 93% and specificity of 88% for a cutoff point of preoperative PEEPi,dyn > or =5 cm H2O. Preoperative PEEPi,dyn correlated well with improvement in forced expiratory volume and dyspnea score after LVRS. Thus, preoperative assessment of PEEPi,dyn could improve risk to benefit stratification before LVRS. IMPLICATIONS: We examined the preoperative ventilatory mechanics of patients with emphysema undergoing lung volume reduction surgery with respect to their value in predicting outcome. Preoperative intrinsic positive end-expiratory pressure correlated well with the increase in forced expiratory volume in 1 s after surgery. Thus, this variable seems promising for improved patient selection.

Adult↗
PubMed1999

Tissue heat content and distribution during and after cardiopulmonary bypass at 17 degrees C.

UNLABELLED: We measured afterdrop and peripheral tissue temperature distribution in eight patients cooled to approximately 17 degrees C during cardiopulmonary bypass and subsequently rewarmed to 36.5 degrees C. A nasopharyngeal probe evaluated trunk and head temperature and heat content. Peripheral tissue temperature (arm and leg temperature) and heat content were estimated using fourth-order regressions and integration over volume from 30 tissue and skin temperatures. Peripheral tissue temperature decreased to 19.7+/-0.9 degrees C during bypass and subsequently increased to 34.3+/-0.7 degrees C during 104+/-18 min of rewarming. The core-to-peripheral tissue temperature gradient was -5.9+/-0.9 degrees C at the end of cooling and 4.7+/-1.5 degrees C at the end of rewarming. The core-temperature afterdrop was 2.2+/-0.4 degrees C and lasted 89+/-15 min. It was associated with 1.1+/-0.7 degrees C peripheral warming. At the end of cooling, temperatures at the center of the upper and lower thigh were (respectively) 8.0+/-5.2 degrees C and 7.3+/-4.2 degrees C cooler than skin temperature. On completion of rewarming, tissue at the center of the upper and lower thigh were (respectively) 7.0+/-2.2 degrees C and 6.4+/-2.3 degrees C warmer than the skin. When estimated systemic heat loss was included in the calculation, redistribution accounted for 73% of the afterdrop, which is similar to the contribution observed previously in nonsurgical volunteers. IMPLICATIONS: Temperature afterdrop after bypass at 17 degrees C was 2.2+/-0.4 degrees C, with approximately 73% of the decrease in core temperature resulting from core-to-peripheral redistribution of body heat. Cooling and rewarming were associated with large radial tissue temperature gradients in the thigh.

Adult↗
PubMed1999

Cognitive functions after pilocarpine-induced status epilepticus: changes during silent period precede appearance of spontaneous recurrent seizures.

PURPOSE: To study the possible relation between spontaneous recurrent seizures (SRS) and the derangement of cognitive memory. METHODS: Status epilepticus (SE) was induced in adult Long-Evans rats by pilocarpine (320 mg/kg, i.p.) and interrupted after 2 h by clonazepam (CZPs mg/kg, i.p.). In addition to the animals that were given pilocarpine and CZP (group P), two groups received ketamine (100 mg/kg, i.p.): the first group 15 minutes after SE onset (group K15), and the second immediately after the CZP (group K120). Control groups were formed from animals not treated with pilocarpine as well as animals that received pilocarpine but did not develop motor seizures. Spatial cognitive memory was tested in the Morris water maze. RESULTS: Testing was impossible for more than 6 days after SE in group P. Ketamine shortened this period for the two groups that received it. During the silent period, deteriorated cognitive memory progressively improved, but the performance of group P started to worsen before the appearance of SRS. Group K120 only expressed a tendency toward declining performance, whereas group K15 never developed SRS, and the behavior of these animals did not differ from that of the controls after the postseizure period was over. Histologically, massive hippocampal cell loss was seen in group P. Ketamine protected hippocampal cells in a time-dependent manner; group K15 did not exhibit any obvious necrosis in the hippocampus. CONCLUSIONS: There is no close relation between cognitive functions and the appearance of SRS, because ketamine, administered 120 min after the beginning of SE, prevented the derangment of cognitive functions but not the appearance of SRSs.

Animals↗
PubMed1999

GABA uptake blocker NNC-711 exhibits marked anticonvulsant action in two cortical epileptic models in immature rats.

PURPOSE: To study the anticonvulsant action of a gamma-aminobutyric acid (GABA) uptake inhibitor NNC-711 in two models of cortical epileptogenesis in immature rats. METHODS: Twelve-, 18-, and 25-day-old rat pups with implanted electrodes were used in this study. Epileptogenic foci were elicited by a local application of bicuculline methiodide (BMI) on the sensorimotor cortical region by means of an implanted cannula, and cortical epileptic afterdischarges (ADs) were induced by low-frequency stimulation (8 Hz) of the same cortical area. Epileptogenic foci were formed after pretreatment with NNC-711 (1 or 10 mg/kg, i.p.), and epileptic ADs were elicited in the second experimental series. Then NNC-711 was administered in the same doses, and stimulation was repeated. RESULTS: NNC-711 did not block the formation of epileptogenic foci, but it significantly suppressed the spontaneous transition of interictal focal into ictal activity in all age groups. The intensity of movements accompanying stimulation of the sensorimotor cortex was less under the influence of NNC-711 in the 18- and 25-day-old rats. The duration of cortical ADs was shortened in all age groups, but transient abolition of ADs was observed only after the higher dose in the 25-day-old rats. In addition, the intensity of clonic seizures appearing during ADs decreased, and the transition of ADs into another type due to an involvement of limbic structures failed to appear in the 18- and 25-day-old rats. CONCLUSIONS: Primary epileptogenesis in the cerebral cortex was hardly influenced by NNC-711, but the spread of epileptic activity was markedly suppressed. This effect was better expressed in the 18- and 25-day-old animals than in the youngest group.

Animals↗