[In memoriam. Academician Zdenĕk Servít].
Explore the source record for details and available documents.
Bibliographies as Topic↗
Biomedical subjects
P Mares
Publications and source records attributed to P Mares.
[Frequency of complications and particular methods of terminating pregnancies in a 2-year study of naturally terminated pregnancies in the Gottwald District].
Explore the source record for details and available documents.
Abortion, Induced↗
Convulsant action of diphenylhydantoin overdose in young rats.
Acute toxicity of diphenylhydantoin (DPH) was studied in 241 male albino rats aged 7, 12, 18, 25 and 90 days. Single intraperitoneal dose of DPH (from 200 to 1000 mg/kg) induced only ataxia and loss of righting reflex in 25-day-old and adult rats. In rats aged 18 days or less ataxia of hindlimbs was also marked. In all these age groups generalized convulsions appeared; they were formed by wild running followed by a clonic phase. The dose of DPH necessary for elicitation of seizures was lowest in 7-day-old rats (75 mg/kg) and increased with age up to 200 mg/kg in 18-day-old rats. The 1000 mg/kg dose was lethal for 25- and 12-day-old rats, but not for 7-day-old ones. The uneven development of excitatory and inhibitory action of DPH is suggested.
Animals↗
Effect of prolonged hypobaric hypoxia during postnatal development on myelination of the corpus callosum in rats.
Infant rats, together with the female, were exposed to a simulated altitude of 7,000 m every day from birth to the age of 17 days, excepting the 6th, 7th, 13th and 14th day. Animals were studied on the 18th day, 20 hours after the last exposure to hypoxia. Rats aged 12, 15 and 18 days acted as the controls. The number of myelinated axones of the corpus callosum rose from the 12th to the 18th day; the number in animals exposed to hypoxia did not differ significantly from the number in the 15-day-old controls. Axonal section area likewise increased from the 12th to the 18th day and again the value in animals exposed to hypoxia was no different from section area in 15-day-old animals. The number of myelin lamellae rose from the 12th to the 18th day, but in animals exposed to hypoxia it did not differ significantly from the value found in 12-day-old animals. The thickness of the myelin layer increased from the 12th to the 18th day; in the experimental animals it was the same as in the 12-day-old controls. The myelin lamellae likewise became thicker, between the 12th and the 15th day; in animals exposed to hypoxia this parameter was the same as the value in 12-day-old rats. In the electrophysiological part of the study, the development of the interhemispheric response was analysed. In animals exposed to hypoxia, the individual waves of the IHR had the same shape and latent periods as in 15-day-old animals. The results demonstrate that hypoxia has a profound effect on morphological and functional maturation of the corpus callosum in infant rats.
Aging↗
[Abortion in relation to reproductive behavior and the outcome of the subsequent pregnancy].
Explore the source record for details and available documents.
Abortion, Induced↗
Influence of clonazepam on electrocorticographic changes induced by metrazol in rats during ontogenesis.
The action of clonazepam (CZP) pretreatment on metrazol-induced ECoG phenomena was studied in Wistar albino rats. ECoG was recorded in acute experiments in male rats 7, 12, 18, 25 and 90 days old (N = 162). CZP (0.1 or 0.02 mg/kg) was injected i.p. 10 min prior to the start of repetitive administration of metrazol (PTZ, 20 mg/kg i.p. every 5 min). Latencies of the first signs of PTZ action, of the rhythmic metrazol activity, of the first ictal activity and of the generalized seizure were measured. CZP exhibited a dose-related effect against ECoG signs elicited by PTZ. A statistically significant increase in latencies was observed with the dose of 0.1 mg/kg in 18 day old and older animals. The 0.1 mg/kg dose of CZP also completely blocked generalized ictal activity in 7 day old rats. In adult animals, CZP pretreatment led to the appearance of partial seizures, a phenomenon never seen in controls. The development of CZP effects corresponds to the maturation of benzodiazepine binding sites.
Aging↗
Rhythmic metrazol activity and cortical spreading depression.
The incidence of segments of rhythmic metrazol activity (RMA) in cortical leads and in the thalamus and hippocampus was studied in acute experiments on nine male albino laboratory rats. First of all we studied activity after administering metrazol in an i.p. dose of 50 mg/kg, without any further treatment, and then, after a control recording, we induced cortical spreading depression and observed its effect on the incidence and synchronization of RMA in the individual leads. We came to the conclusion that the thalamus is incapable of isolated production of RMA. The cortex is able to produce RMA without participation by the studied structures of the specific thalamus and hippocampus; RMA probably originates in the cortex itself. Generalization is impaired, but not eliminated, by a cortical block. The hippocampus independently produces another type of rhythmic activity.
Animals↗
Influence of ethosuximide and dipropylacetate on metrazol-induced electrocorticographic changes during ontogenesis in rats.
Influence of ethosuximide (ESI, 125 mg/kg i.p.) and dipropylacetate (DPA, 300 mg/kg i.p.) pretreatment on electrocorticographic changes induced by pentamethylenetetrazole (PTZ, 20 mg/kg dose every 5 min) was studied in rats aged 7, 12, 18 and 90 days. PTZ alone induced isolated spikes and/or sharp waves as the first sign of its action in all age groups except in adult animals where rhythmic theta activity was elicited. The antiepileptic effect of DPA was observed in 12- and 18-day-old rats, ESI specifically inhibited rhythmic activity in adult rats. ECoG seizures induced by high doses of PTZ were inhibited by DPA in all age groups, ESI tended to be effective in adult rats only. DPA did not change the pattern of ECoG seizures, whereas ESI led to replacement of the spike-and-wave rhythm by serrated waves in adult animals. The low ability of immature brain to generalize ictal activity was further diminished by ESI.
Animals↗
Influence of propranolol on rhythmic electrocorticographic activity induced by metrazol in rats.
Influence of propranolol (5 mg/kg i.p.) on rhythmic metrazol activity (RMA) was studied in 11 male albino rats with chronically implanted cortical as well as subcortical (thalamic ventrobasal complex and dorsal hippocampus) electrodes. Metrazol was injected subcutaneously at a low dose of 30 mg/kg. Another group of five rats was used to study the action of propranolol on spontaneously appearing episodes of rhythmic spikes as well as on vigilance. The incidence of both rhythmic metrazol activity and episodes was significantly increased by propranolol. The latency to the first burst of rhythmic metrazol activity and to the maximum of its incidence was significantly shortened by propranolol. Propranolol also increased the incidence of relaxed wakefulness and delayed the appearance of slow wave sleep. The facilitation of RMA and spontaneous episodes could not be explained only by the increased amount of relaxed wakefulness, i.e. the vigilance level necessary for these two phenomena, because these changes did not coincide in time. In two animals, the combination of propranolol and metrazol led to the appearance of ictal activity which was sometimes accompanied by partial clonic convulsions. This phenomenon was never seen after metrazol alone (30 mg/kg s.c.) in control recordings. Propranolol was found to potentiate the possible models of human absences--spontaneous episodes, RMA and minimal clonic seizures.
Animals↗
[Stimulation of ovulation by pure FSH for in vitro fertilization. Study of the route of administration].
Pulsatile injection of FSH to stimulate ovulation for in vitro fertilization was undertaken in order to compare the intramuscular route with the pulsatile subcutaneous route in two groups of 6 patients each selected at random. The patients were selected in such a way as to reduce as far as possible the parameters that would make it difficult to interpret the results. Both from the point of view of the numbers of patients who responded to stimulation of ovulation as well as the numbers of pregnancies that were obtained, the intramuscular route seems to be preferable.
Adult↗
Changes in the activity of rat cortical and hippocampal neurones after the iontophoretic administration of beta-endorphin, glutamate and GABA.
The effect of microiontophoretically administered beta-endorphin on the activity of 62 cortical and hippocampal neurones was studied in acute experiments on 14 rats. The effectiveness of beta-endorphin was first of all verified in the isolated guinea pig ileum, the mouse was deferens and in a study if its analgetic and catatonic effect in rats. Beta-endorphin only mildly depressed the spontaneous activity of cortical neurones, but markedly inhibited the activity stimulated by the microiontophoretic administration of glutamate. In the hippocampus, beta-endorphin stimulated the activity of all the studied neurones when only low ejection currents were used and activation persisted for 1-4 min after terminating administration. With higher ejection currents, the discharge frequency rose enormously and not even GABA blocked this effect. The excitatory effect of beta-endorphin on the hippocampal neurones may possibly be the basis of the epileptogenic action of this substance.
Action Potentials↗
Influence of valproate and carbamazepine on symmetrical cortical penicillin foci in the rat.
Two epileptogenic foci were formed in homotopic areas of sensorimotor cortices of both hemispheres by application of penicillin. Both valproate (200 and/or 400 mg/kg i.p.) and carbamazepine (50 and/or 100 mg/kg i.p.) did not significantly alter the synchronization of interictal focal discharges. The incidence of ictal phases was suppressed by both drugs in a dose-dependent manner--higher doses (valproate--400 mg/kg; carbamazepine--100 mg/kg i.p.) fully blocked the seizures. Both drugs did not suppress the projection of focal discharges into the opposite hemisphere but were efficacious against secondary generalization.
Animals↗
Epileptic after-discharges induced by hippocampal stimulation in rats.
Among the experimental models of epileptic seizures there is a lack of an adequate model of partial seizures with complex symptomatology. This is due to the fact that the disturbance of consciousness is the main symptom of this type of human seizures, whereas motor signs appear only as epileptic automatisms. Therefore, experimental epileptology focuses its attention on electrophysiological phenomena connected with these fits. The commonly used model is an after-discharge (AD), induced by electrical stimulation of the hippocampus. Its electrographic pattern resembles phenomena recorded by means of deep electrodes in human temporal seizures (Kreindler 1965).
Animals↗
[Enzymatic determination of urinary estrogens. A 5-year experience in a hospital milieu].
The enzymatic method for urinary estrogens determination from Nicolas et al. has become a useful tool for the management of infertility problems. It can be used for: investigation of ovarian by establishing the urinary estrogens profile during menstrual cycle, useful to: understand anomalies of the spontaneous cycle, explain some therapeutic failures during IVF attempts or artificial inseminations (AID or AIC); prediction of failures during IVF attempts during spontaneous cycles, and monitoring ovarian response during stimulated cycles in order to determine the trigger with hCG; monitoring ovulation during induction of ovulation in anovulatory patients stimulated with various drugs (clomiphene citrate, pure FSH combination of FSH and LH, GnRH ou analogs...) under various conditions of prescription and administration (oral, IM, intermittent pulsatile administration with portable pump with or without hypophyseal down regulation). This technique allows also exploration of androgens after changing main androgens (delta 4 A, T, DHEA, DHEA S) into estrogens through the action of placental aromatase, as well as appreciation of aromatase activity of some tissues in the presence of androgenic substrates. This paper gives the conclusions after 5 years of practice with this method and summaries different works published by the biologists who developed the method and by the clinicians who used its results.
Adolescent↗
[Tubal sterility: fertilization in vitro or microsurgery].
In this review paper the respective places of microsurgery and in vitro fertilization in the treatment of tubal infertility are evaluated. The best and current results of the two methods are compared and their future is considered. Most of the indications for microsurgery remain, while some (e.g. poor prognosis salpingostomy, repeated tuboplasty, tubal transplantation) require discussion and new ones are appearing. The advent of in vitro fertilization has introduced some technical changes in surgery of the ovaries and surrounding tissues and has given rise to new techniques. It has also modified the initial investigations in infertile women and the use of pre-operative and second-look laparoscopy. It has exerted little influence on microsurgeons specialized in problems of reproduction but has obliged their teams to be reorganized on a multidisciplinary basis in order to cope with new techniques.
Fallopian Tube Diseases↗
Correlation between electrocorticographic and motor phenomena induced by pentamethylenetetrazol during ontogenesis in rats.
Motor and electrocorticographic (ECoG) phenomena induced by pentamethylenetetrazol (PTZ) were directly compared in adult as well as in young rats (age groups of 7, 12, and 18 days). The technique for implantation of cortical electrodes was elaborated in young rats. Myoclonic jerks were elicited by PTZ in all age groups studied. In adult animals they were accompanied by isolated spikes and/or spike-and-wave complexes, whereas in 7-day-old rats there was a poor correlation between ECoG abnormalities and myoclonic jerks. With increasing age an improved correlation between ECoG abnormalities and behavioral changes were noted. After further injections of PTZ, rats had generalized tonic-clonic motor seizures. Ictal ECoG activity usually started in one cortical region in 7-day-old rats and became progressively generalized whereas in older rats generalized electrical discharges accompanied the motor seizures from onset. The clonic phase of motor seizures was not always accompanied by specific ECoG changes in young rats. At all ages the correlation between ECoG activity and individual phases of the generalized tonic-clonic seizures was poor.
Animals↗
Effect of anticonvulsant drugs on thalamo-cortical and hippocampo-cortical self-sustained after-discharges in the rat.
The action of four antiepileptic drugs was studied in acute experiments in 98 rats. Two types of cortical self-sustained afterdischarges ( SSADs ) induced by rhythmic electrical stimulation of subcortical structures were used as models. SSAD formed by the spike-and-wave rhythm (most frequently induced by stimulation of thalamic somatosensory relay nucleus) was almost completely blocked by dipropylacetate (valproate, 400 mg/kg i.p.) and significantly shortened by ethosuximide (125 mg/kg i.p.). Diphenylhydantoin (60 mg/kg i.p.) tended to prolong this type of SSAD whereas carbamazepine did not influence it. SSAD formed by serrated waves (induced usually by stimulation of the dorsal hippocampus) was augmented by ethosuximide, uninfluenced by dipropylacetate and diphenylhydantoin, and significantly shortened by carbamazepine. The pharmacological profile of the two types of SSADs is in agreement with our hypothesis that the spike-and-wave type of SSAD represents a model of primary generalized seizures of the absence type whereas hippocampo -cortical SSAD could be used as a model of partial seizures with complex symptomatology.
Animals↗
Chromatographic analysis of blood lipids. Comparison between gas chromatography and thin-layer chromatography with flame ionization detection.
Intact human blood plasma lipids of different composition were analyzed by gas chromatography and thin-layer chromatography with flame ionization detection. The reproducibility of the results obtained by gas and thin-layer chromatography was compared. The main advantages and disadvantages of both methods for lipid analysis are discussed. Generally, the variability of the results measured by thin-layer chromatography in series and from day to day was greater than that obtained by gas chromatography.
Chromatography, Gas↗