Morphologic characteristics of sacra associated with assimilation of the last lumbar vertebra.

BACKGROUND: The impact of lumbosacral transitional states on biomechanics of load transmission between the spine and the legs has been sporadically reported. The aims of the study were to identify morphostructural alterations of sacra associated with assimilation of the last lumbar vertebra and to analyse them in the light of their biomechanical impact. MATERIALS AND METHODS: Linear dimensions of sacrum, its body and base and articular surfaces were measured in 31 normal and 41 transitory sacra. Nineteen sacra presented articular and 22 osseous fusion of the last lumbar vertebra. Measured parameters were compared between normal sacra and the two variations of transitory sacra. RESULTS: Sacra with articular fusion of the last lumbar vertebra showed more pronounced concavity of the sacral curvature and wider than long sacral bodies. The first sacral segment was modified, broaden, ventrally wider and elevated. Almost the whole segment bore at its sides auricular surfaces. Very small portion of the segment was non-articular with less pronounced wedging. Sacra with osseous fusion of the last lumbar vertebra showed similar concavity of the sacral curvature as normal sacra, but longer than wide sacral bodies. The ventral sloping half of the newly formed first segment bore auricular surfaces. The non-articular part was enlarged with pronounced wedging. CONCLUSIONS: The term "sacralisation" includes both types of transitory sacra with mutually different morphostructural characteristics in contrast to the normal sacra. Analysis of these morphologic variations may help in understanding the different biomechanical properties and patterns of load transmission.

Anatomy of coronary sinus ostium.

BACKGROUND: The coronary sinus is the main cardiac vein and it has become a clinically important structure especially through its role in providing access for different cardiac procedures. MATERIALS AND METHODS: The study was carried out on 100 randomly selected adult human cadaver hearts fixed in 10% formalin. The transverse and craniocaudal diameters of the coronary sinus ostium (CSO) were directly measured. The presence of the Thebesian valve was noted and the anatomical details of the valve were documented in each case in terms of the shape and extent of coverage of the CSO. RESULTS: Considerable variations in the diameter of the CSO were observed. The mean craniocaudal diameter of the CSO was 8.1 ± 1.51 mm, and the mean transverse diameter was 7.67 ± 1.72 mm. Heart specimens without Thebesian valve tended to have larger ostia. The mean craniocaudal diameter and the mean transverse diameter of the CSO were statistically larger in the specimens without Thebesian valves (p = 0.000 and p = 0.001, respectively). CONCLUSIONS: The Thebesian valves were observed in 86 hearts, and a wide variety of their morphology was seen. The majority of the Thebesian valves were semilunar in shape (74.42%). The extent to which the valve covered the ostium was variable, including remnant valves that covered < 15% of the CSO (35%), and valves that were large and covered at least 75% of the CSO (22.09%). In 3 specimens the valve completely occluded the ostium.

Effect of the calcium channel blockers nifedipine and diltiazem on pentylenetetrazole kindling-provoked amnesia in rats.

A large body of research supports the view that memory disturbance is an integral part of epilepsy. Deficit in various behaviour tasks has been found in rats subjected to experimental epilepsy-pentylenetetrazole (PTZ) kindling. In the present study we examined the effect of post-training administered calcium channel blockers nifedipine (10 and 40 mg/kg) and diltiazem (10 and 30 mg/kg) on amnesia induced by PTZ kindling in shuttle-box- and step-down-trained rats. Retention in nifedipine- or diltiazem-treated kindled animals was significantly improved compared to the kindled controls. The mechanisms of action of calcium antagonists studied is considered. Taken together with the data about calcium channel blocker anticonvulsive activity, the results of this study further suggest that nifedipine and diltiazem might be useful in the treatment of cognitive disorders in epileptic patients.

The GABA-B antagonist CGP 36742 prevent PTZ-kindling-provoked amnesia in rats.

Deficit in active and inhibitory avoidance behaviour has been found in pentylenetetrazole (PTZ)-kindled rats. This supports the view that memory deficit is an integral part of epilepsy. In the present study we examined the effect of the GABA B antagonist CGP 36742 on memory deficit induced by PTZ-kindling in shuttle-box- and step-down-trained rats. The retention in CGP 36742-treated animals was significantly improved compared to the kindled controls. The mechanisms of action of CGP 36742 is considered. The favourable effect of the GABA B antagonist in cases of amnesia provoked by PTZ-kindling might be of interest in clinical practice.

Effects of flunarizine and nitrendipine on electroconvulsive shock- and clonidine-induced amnesia.

This study was designed to examine the calcium channel blockers flunarizine and nitrendipine for their ability to prevent electroconvulsive shock (ECS)- or clonidine-induced deterioration of the inhibitory avoidance performance (step-down) in rats. Flunarizine (10 mg/kg) and nitrendipine (40 mg/kg) were found to prevent the ECS- or clonidine-provoked amnesia after oral administration for 12 days. The mechanisms of action of the two drugs are considered. The results of this study further suggest that calcium antagonists might be useful in the treatment of cognitive disorders.

Effects of verapamil on electroconvulsive shock- and clonidine-induced amnesia.

The effect of the Ca2+ blocker verapamil on amnesia induced by electroconvulsive shock (ECS) or by the alpha-adrenoceptor agonist clonidine was studied in male Wistar rats trained in passive avoidance task ("step down"). Clonidine (0.1 mg/kg, i.p.) and ECS induced a pronounced amnesia, significantly reducing the percentage of rats that had acquired the task upon retention tests, given 3 h, 24 h and 7 days after training. Verapamil (10 mg/kg) administered orally for 12 days (5 days before and 7 days after training) completely abolished the ECS- or clonidine-induced amnesia. These data suggest that calcium channel blocker verapamil has a protective effect against experimentally provoked memory deficit and might be useful for the treatment of cognitive disorders.

Piracetam and fipexide prevent PTZ-kindling-provoked amnesia in rats.

Deficit in active and inhibitory avoidance behaviour has been pentylenetetrazole (PTZ)-kindled rats. This supports the view that memory deficit is an integral part of epilepsy. In the present study we examined the effect of the nootropic drugs piracetam and fipexide on memory deficit induced by PTZ-kindling in shuttle-box- and step-down-trained rats. The retention in piracetam- and fipexide-treated animals was significantly improved compared to the kindled controls. The mechanisms of action of the two drugs are considered. The favourable of nootropic drugs in cases of amnesia provoked by PTZ-kindling might be of interest in clinical practice.

Pentylenetetrazole kindling impairs long-term memory in rats.

The effect of pentylenetetrazole (PTZ) kindling on learning and retention in active (shuttle-box) and passive (step-down) avoidance was studied in rats. PTZ kindling did not impair learning and significantly disturbed long-term memory estimated from retention tests, i.e. PTZ kindling induced a retrograde amnesia in the active and passive avoidance situations. The present results support the view that memory deficit is an integral part of epilepsy.

The 5-HT2 receptor antagonist ketanserine prevents electroconvulsive shock- and clonidine-induced amnesia.

The 5-HT2-selective antagonist ketanserine was examined for its ability to prevent electroconvulsive shock (ECS)- or clonidine-induced performance deficit in the passive avoidance situation (step-down) in rats. The posttrain intraperitoneal injection of ketanserine at doses of 3 and 10 mg/kg prevented the ECS- or clonidine-provoked amnesia upon retention tests given 3 h, 24 h, and 7 days after training. The present data favor the view that the selective modification of 5-HT2 receptors after training can prevent the performance deficit in step-down-trained rats and suggest a role of the 5-HTergic neurotransmitter system in memory. The results of this study further suggest that 5-HTergic receptor antagonists might be useful in treatment of cognitive disorders.

Adafenoxate abolishes the amnesia induced by neonatal 6-hydroxydopamine treatment in rats.

The effect of neonatal 6-hydroxydopamine (6-OHDA) treatment on learning and memory and on the levels of biogenic monoamines in some brain structures, as well as the influence of the nootropic drug adafenoxate on 6-OHDA effect was studied in shuttle box and step down trained rats. In mature rats injected with 6-OHDA postnatal, learning and retention were impaired and the noradrenaline (NA) level in the frontal cortex and hippocampus was decreased. Adafenoxate abolished the amnestic effect of 6-OHDA and restored the NA level to normal in the above-mentioned brain structures. This finding suggests the important role of the noradrenergic neurotransmitter system in 6-OHDA-induced amnesia and the favorable effect of adafenoxate on learning and memory impaired by 6-OHDA.

Impairment of learning and memory in shuttle box-trained rats neonatally injected with 6-hydroxydopamine. Effects of nootropic drugs.

The effect of neonatal 6-hydroxydopamine (6-OHDA) treatment on learning and retention and on the level of biogenic monoamines in some brain structures as well as the influence of the nootropic drugs--piracetam, aniracetam, meclofenoxate and fipexide on the 6-OHDA-induced effect was studied. Two- way active avoidance (shuttle box) was used. The levels of noradrenaline (NA), dopamine (DA) and serotonin (5-HT) in the frontal cortex, striatum, hypothalamus, hippocampus and pons were measured. In mature rats, injected with 6-OHDA (100 mg/kg s.c.) in the first 3 postnatal days learning and retention were impaired and the NA level in the frontal cortex and hippocampus was decreased. Piracetam (600 mg/kg), aniracetam (50 mg/kg), meclofenoxate (100 mg/kg) and fipexide (10 mg/kg) administered orally 5 days before and 5 days during training, abolished the amnestic effect of 6-OHDA and restored to control values the NA level in the frontal cortex and hippocampus. This finding suggests the important role of the noradrenergic neurotransmitter system in the 6-OHDA-induced amnesia, as well as in the favorable effect of the nootropic drugs tested on 6-OHDA-impaired memory processes.

[The effect of microinjections of bombesin into the amygdala on the slow-wave frequency of the gastroduodenal smooth muscles and on the migrating myoelectric complex]. / Vliianie mikroin''ektsii bombezina v mindalinu na chastotu medlennykh voln gladkikh myshts gastroduodenal'noi zony i migriruiushchii mioélektricheskii kompleks.

In dogs with electrodes implanted in the smooth muscle wall of the stomach and duodenum, microinjection of bombesin (5 micrograms) during the 2nd phase of the migrating myoelectric complex decreased frequency of slow waves in the stomach, leaving unaltered the frequency of slow waves in the duodenum. Bombesin caused a short-term inhibition of the gastric and intestinal spike activity followed by its increase, the active period of the migrating myoelectric complex being prolonged.

[The effect of pancreatic resection with occlusion of the pancreatic remnant on the morphology of the gastrointestinal system]. / Vliianieto na pankreatichnata rezektsiia s okluziia na pankreasniia ostatuk vurkhu morfologiiata na gastrointestinalnata sistema.

Modern scientific problems are discussed on some still moot aspects of resection surgery of the pancreas from viewpoint of the postoperative divergencies in all other organs of the gastrointestinal system. Experiments were carried out on dogs. Proximal (right) resection of the pancreas was applied and the endocrine function of the remaining part of the organ was eliminated by occlusion of the pancreatic canal. Histomorphologic studies were carried out on different organs of the gastrointestinal system, 4, 5 and 11 months after the pancreas resection. Serious abnormalities and interrelations were found between the glandular apparatus of the gastrointestinal organs and the pancreas resection. Histomorphological proof of the changes are adduced.

[Effect of bombesin on the frequency of slow potentials of the smooth muscles of the gastrointestinal tract and migrating myoelectric complex]. / Vliianie bombezina na chastotu medlennykh potentialov gladkikh myshts zheudochno-kishechnogo trakta i migriruiushchii mioélektricheskii kompleks.

In dogs with electrodes implanted in the smooth muscle wall of the stomach, small intestine and colon, i.v. administration of bombesin (50, 100, 200 and 300 ng/kg) during the 2nd phase of the migrating myoelectric complex (MMC) increased the dose-dependent frequency of slow potential in the small intestine and stomach leaving unchanged the frequency of slow potentials in the colon. Single doses of 50 or 200 ng/kg bombesin during the 2nd phase of the MMC caused a short-term inhibition of the gastric and intestinal spike activity followed by its increase, the active period of the MMC being prolonged.

[Relations between the electric activity of the pyloric sphincter and activities of the stomach and duodenum]. / Zavisimost' élektricheskoi aktivnosti piloricheskogo sfinktera ot aktivnosti zheludka i dvenadtsatiperstnoi kishki.

Indwelled electrodes led electrical activity from the stomach, pyloric sphincter and duodenum in hunger, after feeding or administration of carbachol and morphine as well as after transthoracic vagotomy. In intact resting animals the pyloric sphincter develops slow potentials in the rhythm of stomach antral portion and sometimes in the rhythm of duodenum. Acceleration of the slow potentials rhythm occurring after transthoracic vagotomy in the stomach antral portion, develops in the pyloric sphincter as well. Spike activity of the antral portion spreads over to the sphincter depending on amplitude, frequency and duration of the burst of spikes. Migrating myoelectrical complex develops successively in the stomach antral portion and in the pyloric sphincter. During increased activity of the duodenum (after carbachol or morphine) the bursts of spikes in the rhythm of the duodenum slow waves can occur simultaneously in the pyloric sphincter, too.