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Biomedical subjects

V Susić

Publications and source records attributed to V Susić.

At least 19 recordsLinked to original sources
PubMed2006

Valproate and delta-sleep peptide display high efficacy against metaphit-induced audiogenic seizure in rats.

The effects of valproate (VPA) and delta sleep-inducing peptide (DSIP) on metaphit-induced generalized, audiogenic seizure in adult rat males were compared. The animals were i.p. injected with: (1) Saline; (2) metaphit (mp, 10 mg kg(-1)); 3. metaphit (10 mg kg(-1)) and 8 h later with DSIP (0.1, 0.2, 0.4 or 1.0 mg kg(-1)), 4. metaphit (10 mg kg(-1)) and 8 h later with VPA (50, 75 or 100 mg kg(-1)); 5. DSIP alone (1.0 mg kg(-1)) and 6. VPA, alone (100 mg kg(-1)). The rats were exposed to sound stimulation at hourly intervals and the behavior and EEG were analyzed. The EEG signals in metaphit rats appeared as a sleep-like pattern and spike-wave complexes with increased power spectra. Valproate and DSIP reduced the incidence of seizure and prolonged duration of latency in a dose-dependent manner. ED50 of valproate in the 1st hour after administration was 63.19 mg kg(-1) and that of DSIP 3.19 mg kg(-1) four hours after injection. This suggests that VPA, reached a peak of action immediately after the application, while DSIP had a prolonged action, mildly reducing, but not abolishing metaphit seizure. None of the applied VPA and DSIP doses eliminated the metaphit-provoked EEG signs of epileptiform activity.

Animals↗
PubMed2001

Bovine haematological values during fattening with possible implications for muscle growth.

Haemoglobin concentration (Hb), haematocrit (PCV) and mean corpuscular haemoglobin concentration (MCHC) were determined as indicators of oxygen-carrying capacity in 25 Simmental bulls during intensive fattening. Their possible relations to muscle growth were also investigated. The animals were the progeny of two sires. Blood samples were taken at 6, 9, 12 and 15 months of age. After slaughter, the right thoracic rib cut (7-9) was dissected into the longissimus dorsi muscle (LD), other muscles (OM) and total muscles (TM) (LD+OM). There was a significant increase in the mean PCV and Hb values during fattening. The PCV and Hb values were significantly correlated with the tissue share of OM or TM only at 12 and 15 months of age. LD muscle share was not significantly correlated with any of the parameters at any fattening time. It would appear from these results that muscle growth proceeds in two phases. The first is until the age of 12 months and the other from then to maturity.

Animals↗
PubMed2000

N-Methyl-D-aspartic acid- and metaphit-induced audiogenic seizures in rat model of seizures.

The effects of NMDA (N-methyl-D-aspartic acid) on metaphit (1-[1(3-isothiocyanatophenyl)-cyclohexyl]piperidine)-induced audiogenic seizures in adult male Wistar albino rats were studied with the aim of developing a suitable animal model of seizures. The animals were divided into four experimental groups: 1, saline control; 2, metaphit-injected; 3, metaphit + NMDA administered and 4, NMDA-treated. Upon the treatment, the rats were exposed to sound stimulation (100 +/- 3 dB, for 60 s) at hourly intervals and the incidence and severity (running, clonus and tonus) of seizures were analysed. In group 3, only the animals which did not exhibit any metaphit-induced audiogenic seizures over 8 h were given a subconvulsive NMDA dose after the eighth audiogenic testing. For EEG recordings, three gold-plated screws were implanted into the rat skull. In most animals, metaphit led to EEG abnormalities and elicited epileptiform activity recorded as spikes, polyspikes and spike-wave complexes. Maximum incidence and severity of metaphit-induced convulsions occurred 8 h after injection (incidence 9/12), abating gradually until disappearing 30 h later. NMDA alone provoked no seizure response but the initial signs characterized by isolated spike activity evolving into sporadic slow-wave complexes, thus representing a proconvulsive brain state, were observed. This compound led to stereotyped behaviour seen as asymmetric posture, loss of righting reflex and tonic hind limb extension lasting for 60-90 min. It also potentiated metaphit-induced audiogenic seizures. Potentiation of metaphit-related audiogenic seizures by NMDA was recorded in three out of 17 rats that had never displayed seizures in eight previous testings, with a maximum incidence of eight out of 17 animals, 13-14 h after metaphit administration and seizures lasted for 10 h.

Animals↗
PubMed1999

Inhibition of metaphit-induced audiogenic seizures by APV in rats.

The influence of APV ((+/-)-2-amino-5-phosphonovaleric acid) on EEG activity and behavior was studied on a model of epilepsy induced by intraperitoneal administration of metaphit (1-(1-(3-isothiocyanatophenyl)-cyclohexyl)-piperidine). Male Wistar rats received an injection of metaphit (10 mg/kg) and were subjected to intense audio stimulation (100+/-3 dB, 60 s) at hourly intervals during the experiment. The seizures were classified according to a four point scale ranging from 0 (no seizure) to 3 (tonic convulsions). In our report we studied the time course which revealed the maximum incidence and severity of seizures 7-12 h after the injection (10 out of 12 rats, with severity of 2.25+/-0.32). APV (0.05, 0.1, 0.2 and 0.3 micromol) was injected intracerebroventricularly at the time of fully developed convulsions. APV inhibited seizures in a dose-dependent manner. The minimum dose, which completely blocked seizures in all animals, was 0.3 micromol, while ED50 were 0.11, 0.10 and 0.07 micromol against running, clonus and tonus, respectively. In contrast to behavioral inhibition of convulsions, metaphit-provoked epileptiform activity was not abolished by APV, and represented a prerequisite for the reappearance of behavioral seizures. It is suggested that APV is rather an anticonvulsant than an antiepileptic agent in this model of epilepsy.

2-Amino-5-phosphonovalerate↗
PubMed1996

Possibility of blocking n. ischiadicus within foramen ischiadicum majus in sheep.

The blocking of the ischiadic nerve within foramen ischiadicus majus of 8 sheep was performed with 6-12 ml 2% xylocain from three different places: 1. From the middle of a line joining the top of processus spinosus of the 1st sacral vertebra and the peak of trochanter major. The needle pierces vertically through the skin, gluteal fascia and m. gluteus medius till foramen ischiadicum majus. 2. Along the most prominent part of crista iliaca on the gluteal surface of ala ossis ilium along the medial side of well expressed linea glutea. The needle pierces by an angle of 45 degrees through the skin, gluteal fascia and m. gluteus medius till the nerve itself. When the nerve is touched the animal makes a jerk. 3. Along the caudal part of tuber sacrale with the needle orientated caudo-ventro-laterally through the skin, gluteal fascia and m. gluteus medius toward foramen ischiadicum majus. The most appropriate approach for blocking is along crista glutea on the gluteal surface of ala assis ilii. In this approach the success is complete. The symptoms of the blocking appear immediately after the application. The complete akinesia of the limb appears 15 minutes after the application of 6 ml, and 5-10 minutes after being applied 12 ml of 2% xylocain. The blocking symptoms disappear within 90-100 or 120-140 minutes. Beside the blocking of n. ischiadicus, a simultaneous blocking of n. gluteus cranialis, n. caudalis and n. cutaneus femoris caudalis as well was performed within foramen ischiadicus majus.

Anesthetics, Local↗
PubMed1996

[Survey about the motivation for the study of veterinary medicine in Croatia].

The aim of this work was to find out the factors which determine the motivation of students for the veterinary school. The sociologically relevant circumstances, specific for Croatia--as a post-socialistic country--which might influence the motivation of students are presented in the work. The results showed that 89,4% students chose this study by themselves, 62.3% did not have any known veterinarian as a paragon, 44% were familiar with the contents of the veterinary profession. 97,8% are aware of the poor financial condition of the veterinarians, and the majority is aware of the bad reputation of this profession in Croatia. It was concluded that under these circumstances the candidates for the veterinary profession are motivated through direct affection to the profession and the love to animals.

Animals↗
PubMed1993

Potentiation of metaphit-induced audiogenic seizures by REM sleep deprivation in rats.

The possibility that REM sleep deprivation (REMD) induced increased susceptibility of rats to the convulsive effects of metaphit was investigated. Metaphit-induced audiogenic seizures were studied in three groups of animals: 1) caged controls; 2) large platform animals; and 3) small platform, REMD animals. After 48 h of confinement to their environments the rats from all three groups were injected with metaphit (10 mg kg-1, IP) and the procedures continued for the next 24 h. Immediately after removal from platforms and at 3-h intervals thereafter all rats were individually subjected to intense sound stimulation. Convulsive responses were recorded and analyzed with respect to incidence, intensity, and duration. The REMD rats were found to be more sensitive to the convulsive effects of metaphit compared to nondeprived rats. This was manifested in significantly shorter latencies to seizures, and significantly higher incidence, severity, and duration of seizures, especially of the most severe seizure component-tonic extensor convulsion. Inducing rats to convulse while they were being REM sleep deprived eliminated the REM sleep rebound observed in REMD rats that did not convulse. The occurrence of spontaneous EEG seizures during the undisturbed recovery period reduced REM sleep rebound. The results demonstrate a reciprocal relation between seizure behavior and REM sleep.

Acoustic Stimulation↗
PubMed1989

Reduced rapid eye movement sleep latency in patients with Parkinson's disease.

Rapid eye movement (REM) sleep latency (time from sleep onset to the first REM episode) was measured in 39 patients with idiopathic Parkinson's disease. Reduced REM sleep latency (less than or equal to 65.0 min) was found in a high proportion of patients (69%). Since reduced REM sleep latency may be a trait-like abnormality relatively specific to primary depression, we evaluated this parameter in two groups of parkinsonian patients: depressed (16 patients) and non-depressed (23 patients). Its incidence was significantly higher in depressed patients with Parkinson's disease.

Aged↗
PubMed1989

"Recovery" function of sleep: effects of purified human interleukin-1 on the sleep and febrile response of cats.

From cats prepared for chronic pollygraphic recording of sleep patterns, records were obtained for 8 hr, after (1) intracerebroventricular (i.c.v.) injection of artificial cerebrospinal fluid (aCSF), day 1; (2) i.c.v. injection of interleukin-1 (Il-1), day 2; and (3) injection of aCSF, day 3. Three doses of Il-1 were tested. The dose of 40 nmol totally inhibited sleep, whereas the dose of 10 nmol slightly prolonged sleep. The dose of 20 nmol of Il-1 elicited sleep and a body temperature increase. Total sleep (TS) time was significantly increased, due mainly to the significant increase in non-REM (NREM) sleep as compared to control day 1. REM sleep was also increased, but this increase did not reach statistical significance. Wakefulness (W) was significantly reduced. At this time cats were febrile. On day 3, a further significant increase in TS occurred. NREM was significantly increased compared with day 1, whereas the increase in REM sleep was significant compared to both day 1 and day 2. At this time body temperature was normal. The increase in REM sleep on days 2 and 3 resulted entirely from the significant increase in the number of REM periods. The results show that Il-1 at a dose of 20 nmol has sleep-promoting effects on NREM and REM sleep concomitant with pyrogenic effects. These two responses differed in their time courses and were not correlated (correlation coefficients were all nonsignificant).

Animals↗
PubMed1987

The effects of delta-sleep-inducing peptide (DSIP) on wakefulness and sleep patterns in the cat.

The effect of a single injection of synthetic delta-sleep-inducing peptide (DSIP, 7 nmol/kg) into the lateral ventricle of 10 cats was investigated by monitoring the sleep-wake cycle during an 8 h period. A significant decrease in sleep latency and a significant increase in total sleep and in total slow wave sleep (SWS) was found following DSIP administration. The increase in sleep resulted exclusively from a significant increase in deep slow wave sleep (S2), while light slow wave sleep (S1) was significantly decreased. Neither the total amount of REM sleep, nor hourly values of REM sleep were affected by DSIP application. Additional measures of REM sleep, like REM sleep latency, mean episode number and mean episode length were not different from those found in control conditions. DSIP was immediately effective since the amount of S2 increased to more than 50% in the first postinjection hour and the difference from the control value was highly significant. The increase in S2 was maintained over 7 h, and disappeared by the eighth hour. The increase in S2 was caused by a prolongation of S2 episodes and not by their more frequent occurrence. The results obtained suggest a sleep-facilitating property of DSIP.

Animals↗
PubMed1987

The effect of subcutaneous administration of delta sleep-inducing peptide (DSIP) on some parameters of sleep in the cat.

Delta sleep inducing peptide (DSIP) significantly increases deep-slow-wave sleep (DSWS) of cats after subcutaneous (SC) injection. Cats (n = 8) were SC injected with DSIP (120 nmol.kg-1) prior to polygraphic recording of EEG combined with electro-oculography, EOG) and electromyography (EMG) for 8 hours. DSIP was found to significantly increase slow-waves (delta sleep) in the sleep EEG. There was a tendency to reduced waking time and a prolongation of slow wave sleep time, and a shortening of sleep onset and REM sleep latencies but the differences from control (Ringer injection) were not statistically significant. There was no change in the amount of REM sleep. These findings support the belief that DSIP can increase sleep wave activity when administered by peripheral route.

Animals↗
PubMed1986

Sleep patterns in the Mongolian gerbil, Meriones unguiculatus.

Sleep patterns were studied in Mongolian gerbils and normative values were derived from 48 hour recordings, during a 24-hr light-dark cycle (LD 12:12). Behavioral and electrographic observations confirmed the existence of well defined sleep states: slow-wave sleep (SWS) and paradoxical sleep (PS). During the light period, sleep occupied slightly more than half of the 12 hour period, 57.13 +/- 0.002% out of which 49.64 +/- 0.007% was occupied by SWS and 8.07 +/- 0.007% by PS. There were 23 +/- 0.01 episodes of PS with a mean duration of 2.32 +/- 0.01 min. During the dark period, sleep occupied slightly less than half of the recording time (51.75 +/- 0.01%). They spent 41.62 +/- 0.006% in SWS and 10.12 +/- 0.02% in PS. The number of PS episodes was 32 +/- 0 with a mean duration of 2.28 +/- 0.01 min. Sleep cycle duration was 7.80 +/- 3.76 min. The ratio day/night sleep was 1.17 +/- 0.002 min. We found that the gerbil in captivity, unlike most rodents that are nocturnal, is a crepuscular animal, being more active at the transitions between light and dark.

Animals↗
PubMed1985

Effects of delta sleep inducing peptide on sleep cycle of cats deprived of paradoxical sleep.

The effect of synthetic delta sleep inducing peptide (DSIP) on sleep was investigated in cat. DSIP (7 nmol/kg was administered intracerebroventricularly to cats deprived of paradoxical sleep (PS) for 72 h and immediately after termination of PS deprivation an injection of either Ringer or DSIP solution was given. Eight h of recovery sleep was then recorded. DSIP failed to affect the duration of slow-wave sleep, PS and total sleep time. There was, however, significant decrease of wakefulness and light slow-wave sleep (S1) while deep slow-wave sleep (S2) was significantly increased. There was also no change in the latency to the first episode of S2 sleep and PS. Thus, we conclude that DSIP altered the relative amounts of S1 and S2 sleep, causing more S2 (delta) sleep at the time when pressure for sleep was at its highest due to prior sleep deprivation.

Animals↗
PubMed1981

Effects of repeated administrations of dihydroergotoxine (Redergine) on the sleep-wakefulness cycle in the cat.

Investigations with dihydroergotoxine methane sulfonate (DHET, the active substance of Redergine) indicate that DHET acts on the sleep-wakefulness cycle of the cat by increasing wakefulness and slow-wave sleep and decreasing rapid eye movement sleep. DHET was administered intraperitoneally at a dose of 1.0 mg/kg for 5 successive days. The effects were fairly stable, although with a tendency to diminish with time. Such alterations in the sleep-wakefulness cycle are discussed as possible indices of the beneficial effects seen in elderly patients treated with DHET.

Animals↗
PubMed1981

Effects of dihydroergotoxine methane sulphonate (Redergine) on sleep in cats deprived of paradoxical sleep.

Dihydroergotoxine methane sulphonate (DHET 1.0 mg/kg i.p.) was administered to cats deprived of paradoxical sleep (PS) for 72 h and 23 h of recovery sleep were recorded. During the first 12 h of recovery sleep slow-wave sleep (SWS) was significantly increased. There were no significant changes in the amounts of wakefulness (W), PS and several sleep indices. Analysis of the entire 23 h of recording period revealed no significant changes in any of the parameters studied. The results suggest that DHET has SWS enhancing property in the condition where "pressure" for PS was increased.

Animals↗
PubMed1980

Effects of restricted sleep with different exercise loads upon subsequent sleep.

Seven male cats were adapted to different schedules of restricted sleep. The cat was permitted to go to sleep either 2, 4 or 8 hours per day with the balance to 24-h periode spent in wakefulness enforced by means of a treadmill. Two experiments were run and the same cats served in both runs. The experiments and schedules were separated by at least two weeks during which time cats were maintained under ordinary laboratory conditions. Our experiment used treadmill speed of 2.6 m/min which was easily tolerated and effective in eliminating sleep. Another experiment used treadmill speed of 4.6 m/min which produced more physical exercise. As available sleep time become progressively shorter, REM sleep increased while SWS decreased. If restriction in sleep time was associated with more physical exercise then the composition of the subsequent sleep was different : SWS increased while REM sleep decreased. The functional significance of these opposite effects are presumably different. The immediate SWS response to the prior muscular exercise is suggestive of its recovery function.

Animals↗
PubMed1980

Sleep-waking cycle and behaviour after diethyldithiocarbamate in the rat.

Young adult Louis rats were implanted for chronic sleep recording to test the effect of diethyldithiocarbamate (DDC) on sleep. Recordings of EEG and EMG were done continuously for 12 h during the 12 consecutive days. There were 2 days of baseline recording, 3 days of recording with a single daily injection of placebo, 3 days of recording with a single daily injection of DDC (500 mg/kg i.p.), and 3 days of DDC withdrawal recording with placebo injection. Placebo injections did not change the proportion of time spent in different behavioural states. With daily injection of DDC there was an increase in wakefulness, no change in slow-wave sleep and elimination or drastic reduction in paradoxical sleep (PS). There was no PS rebound during the DDC withdrawal days. These results suggest that the reduction of PS produced by DDC and the absence of PS rebound may be due to a lowering in norepinephrine in the brain. In other experiments rats were injected with DDC (500 mg/kg i.p.) daily for 3 days and whole brains were analysed chemically. Norepinephrine was significantly decreased, while 5-hydroxytryptamine, 5-hydroxyindolacetic acid, dopamine and homovanilic acid were unchanged. Seizure activity appeared during relaxed wakefulness in all rats treated with DDC. Taken together it seems that lowering of brain NE is responsible for the appearance of seizure activity and also, for PS reduction. PS reduction might, per se, produce seizure activity.

Animals↗