[Anterior capsulotomy with the YAG laser: technics and advantages].
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Cataract Extraction↗
Biomedical subjects
W Wetzel
Publications and source records attributed to W Wetzel.
[Posterior chamber lens implantation in glaucoma].
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Aged↗
Effect of the memory-improving substance methylglucamine orotate on paradoxical sleep in rats.
The effects of methylglucamine orotate (MGO) were studied on polygraphic sleep recordings in rats for 8 h per day between 8 a.m. and 4 p.m. MGO (225 mg/kg) was injected intraperitoneally immediately prior to the onset of recording. In the acute experiment, the effect of MGO was compared to pre- and post-drug control days. In the chronic experiment, a sequence of 5 control days, 10 days of MGO treatment, and a further 8 control days was tested. Both acute and chronic administration of MGO resulted in increased paradoxical sleep (PS) latency and a small, but significant, decrease in PS during the first 4 h after injection. This effect seems to be specific to PS, as no effects of MGO on waking or total sleep were found. With chronic administration, no PS rebound occurred within the 8-h recording time during the 8-day post-treatment control period. How the RNA precursor can decrease PS and whether this effect may play a role in the memory-improving action of the substance is discussed in terms of an interrelationship between macromolecular synthesis, sleep, and memory, respectively.
Animals↗
Memory retention in old rats: improvement by orotic acid.
The effect of methylglucamine orotate (MGO) on learning and memory was investigated in 24-month-old rats using brightness discrimination in a Y-chamber and active avoidance in a shuttle box. In both learning procedures, an improvement of memory retention following 5-day MGO treatment (225 mg/kg per day) was observed. The retention of untreated old animals was significantly lower compared to 8-week-old rats. MGO treatment resulted in a significant improvement of retention in old rats, which nearly compensated for their memory deficit.
Aging↗
Odontogenic keratocyst: diagnosis and treatment.
The odontogenic keratocyst is a keratinizing squamous epithelium-lined cyst that occurs in the mandible and maxilla. In 5% to 10% of patients the keratocysts may be a manifestation of the basal cell nevus syndrome. The recurrence rate after surgical therapy for odontogenic keratocysts varies from 10% to 63%.
Adult↗
Malignant granular cell tumor of the tongue.
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Diagnosis, Differential↗
Differences in Y-maze retention of rats: selection according to open field activity.
Adult male Wistar rats of a heterogeneous outbred population were selected according to their open field ambulation and classified into two groups: animals showing the most activity during the first 2 min (A, fast habituation), or after the first 2 min (B, delayed habituation) of a 10 min observation period. One week later these rats were tested for foot-shock motivated brightness discrimination learning and retention in a Y-maze. It was found that group A rats exhibited higher %-savings than group B rats, whereas their learning performance was not different. Thus, our results show that rats differing in their Y-maze retention ability can be selected on the basis of certain open field measures.
Animals↗
Acquisition and retention in different learning tasks in old rats.
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Aging↗
Effect of substance P on the retention of a brightness discrimination task in rats.
The effect of substance P (SP) on acquisition and retention of a footshock-motivated brightness discrimination was investigated in rats, 250 micrograms SP/kg were injected intraperitoneally either 30 min before or immediately after the training session. Acquisition of the brightness discrimination was not affected by SP administered 30 min before training. However, both the pre-training and post-training injections of SP resulted in a significant improvement of retention tested 24 h after training. The effect of SP on memory consolidation is discussed.
Animals↗
Effect of methylglucamine orotate on intracranial self-stimulation.
The effect of the memory improving substance methylglucamine orotate (MGO) on intracranial self-stimulation was investigated in rats. Self-stimulation (0.2 mn square pulses; 100 Hz frequency; 400 mn chain; 100-300 micro A current) was performed using electrodes in the lateral hypothalamus. MGO was administered intraperitoneally in doses of 112.5 mg/kg and 225 mg/kg or intraventricularly in a dose of 225 micrograms per rat. In chronic experiments, daily intraperitoneal injections of 225 mg/kg MGO were given during 10 days. The results show that intracranial self-stimulation is scarcely influenced by a single injection of retention improving MGO doses, but increased significantly by repeated MGO application.
Animals↗
[Behavioral investigations following cholinergic deafferentiation of the hippocampus by septal lesions in rats (author's transl)].
Acquisition and retention of a visual discrimination task as well as changes in the exploratory activity and emotional state of the animals were investigated in rats with different lesions in the telencephalic septal area. The cholinergic deafferentiation of the hippocampal formation due to the lesion was determined by quantitative histochemical estimations of the loss in acetylcholine esterase activity in the various subfields of the hippocampus and the results were correlated to the behavioral experiments. Total bilateral septal lesion resulted mainly in an impairment of the acquisition processes of the discrimination task combined with an enhancement of the retention index. Slight tendencies for attenuated activity in the exploratory and emotional behavior were also present in this group. Assymmetric septal lesions leaving one lateral septal nucleus undamaged caused higher activities in the exploratory and emotional behavior. Some enhancement of the retention index was found, too. The degree of cholinergic innervation of the hippocampus was partially involved in the behavioral effects.
Acetylcholinesterase↗
Improvement of shuttle-box avoidance by combinations of orotic acid and central stimulants.
The effect of orotic acid and central stimulants on retention of shuttle-box avoidance was investigated in rats. Orotic acid (100 mg/kg) was injected 30 min before training; caffeine (20mg/kg), strychnine (1 mg/kg), or methylphenidate (10 mg/kg) were injected immediately after training. When given alone, these drugs improved avoidance retention when tested 24 h after training. However, improvement of retention was much more evident when orotic acid was given in combination with a stimulant. The data are discussed in relation to the role of macromolecule synthesis and arousal in memory formation.
Animals↗
Effect of L-fucose on brain protein metabolism and retention of a learned behavior in rats.
The intraperitoneal or intraventricular application of L-fucose (100 mg/kg or 75 microgram, respectively) prior to training in shuttle box avoidance as well as in shock-motivated brightness discrimination in rats significantly improved the retention of learned behavior 24 hr later. The application of D-fucose was without influence on retention. In naive animals, intraventricularly applied L-fucose (75-200 microgram) caused an increase in the rate of protein synthesis in the hippocampus, resulting in a significant increase in total proteins of this brain structure, mainly attributed to the Tris-insoluble protein fractions. The results are discussed in terms of an activation of glycoprotein formation by increasing supply with L-fucose.
Animals↗
Effect of serotonin on Y-maze retention and hippocampal protein synthesis in rats.
The effect of serotonin (5-HT) on consolidation of a brightness discrimination reaction was investigated in rats. Five microgram 5-HT, injected intrahippocampally immediately after training, impaired retention of the brightness discrimination tested 24 hr later. In biochemical experiments, leucine incorporation into hippocampal proteins in vivo was 32% inhibited by 5 microgram 5-HT. Leucine incorporation into proteins of hippocampal slices in vitro was decreased by 5 x 10(-5)M 5-HT. The results seem to support Essman's assumption that inhibition of brain protein synthesis by 5-HT may be responsible for the memory impairment. But also some other possibilities for a mechanism of 5-HT amnesia must be discussed.
Animals↗
The persistence of the effect of methylglucamine orotate on the retention of a learned behavior in the rat.
The effects of methylglucamine orotate (MGO) on the retention of a brightness discrimination in rats was investigated after different intervals between treatment and acquisition, 225 mg MGO/kg were injected intraperitoneally each day over a period of 10 days. Control animals received a NaCl-solution. After drug-free intervals of 5 days or 12 days respectively, MGO-treated rats showed significantly better retention of the learned reaction than controls, whereas their training performance was not influenced. Possible interpretations of the long-lasting persistence of the orotate effect are discussed.
Animals↗
Postnatal orotate treatment: effects on learning and memory in adult rats.
During the postnatal period, male Wistar rats were treated with orotate, either from the 6th to 15th, 16th to 25th, or 26th to 35th day of life. Learning and memory were tested in adulthood. Rats that received orotate from the 6th to 15th day showed a better retention of a learned brightness discrimination (Y-maze) than controls. An active avoidance (pole jumping) was learned more quickly by the rats orotate-treated from the 6th to 15th day than by controls. The spontaneous locomotor activity of previously orotate-treated rats was the same as in controls. Body weight measurements revealed no differences between orotate rats and control rats. The results suggest that memory retention in adulthood can be improved by postnatal orotate treatment.
Animals↗
Memory impairment in adult rats after postnatal undernutrition.
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Animals↗
Myxoid liposarcoma. An ultrastructural study of two cases.
Two cases in which myxoid liposarcomas were examined by use of light and electron microscopy are presented. The relationship of this tumor to the development of normal adipose tissue is discussed. Most of the ultrastructural features were identical to those of developing white adipose tissue. Features not typical of developing white adipose tissue, such as congeries of 60-Angstrom filaments and large masses of glycogen, are also illustrated and discussed.
Adult↗