d-Amphetamine enhances memory performance in rats with damage to the fimbria

Rats were preoperatively trained on a 5-unit linear maze and were then subjected to fimbria lesions. The animals were then retested on the same task with one group of rats with fimbria lesions and a control group being injected daily with 0.5 mg/kg d-amphetamine sulfate prior to testing. Lesions significantly impaired postoperative performance of the task, while amphetamine facilitated performance in fimbria lesioned rats. Due to an optimal learning of the task, performance of control animals was not significantly facilitated. These results raise several important issues including the mechanisms of functional recovery after brain lesions and the role of the hippocampal formation in learning and memory.

Effects of unilateral cerebral ischemia on the hippocampal theta depth profile in the ether-anesthetized Mongolian gerbil

In gerbils (Meriones unguiculatus) unilateral cerebral ischemia of 5 to 15 min resulted in selective destruction of the ipsilateral hippocampal CA1 stratum pyramidale. It also produced an obvious amplitude reduction in both superficial and deep theta rhythms recorded from damaged hippocampal formation. The presence of normal theta in the left normoxic hemisphere showed that the septohippocampal projections, integrity of which is essential for theta appearance, were spared by ischemia. These data have implications in relation to the two generators hypothesis of theta.

Short-term memory, exploration and locomotor activity in aged rats

Behavioral profiles of young (3-6 months) and aged (24-27 months) rats were compared in three respects: (1) short-term memory, (2) exploration and (3) locomotor activity. Compared to young rats, aged rats were impaired in the 8-arm radial maze acquisition, but not in the delayed reinforced alternation acquisition. They had lower scores of spontaneous alternation, of exploration of a novel object and of a novel environment. Their exploratory activity was lower in a simple environment but similar in a complex environment. Their spontaneous locomotor activity was lower during the dark part of the cycle (8 p.m.-8 a.m.) but not different during the light part of the cycle (8 a.m.-8 p.m.). These results suggest that with respect to short-term memory and exploration, differences between aged and young rats may be influenced by a "complexity" factor and may be secondary to differences in motivation and reactions to novelty.

Effects of selective lesions of fimbria-fornix on learning set in the rat

The effects of selective partial lesions of the Fimbria-Fornix (FiFx) on reversal and place learning sets were investigated in rats by using a T-maze and a semi-circular multiple discrimination apparatus. Lesions restricted to the Fimbria (Fi) produced a significant deficit in reversal and place learning set, whereas lesions to the Fornix (Fx) only disturbed the learning set based on a reversal procedure. Combined Fi + Fx lesions resulted in impairment in the retention of spatial discrimination tested in the two mazes. Ventral Hippocampal Commissure (vhc) had no significant effect on reversal learning set. These results confirm previous data that the hippocampal formation is involved in learning transfer, and suggest that the Fi and the Fx may play a role in learning set. Our data also confirm previous demonstrations of the ability of rats to rapidly acquire place learning set.

[Colitis cystica profunda--contribution to the differential diagnosis of rectum cancer]

A case report is given including endoscopic and morphological findings of a 19 year old female patient with colitis cystica profunda. Diagnosis could only be established by histological examination of material which had been taken from deep layers of the rectum wall. Lesions were so close to the anal region, that no surgical resection was done, because this would had impaired continence. A review of the literature is given in addition to the case report.

Depth of information in photoelectron microscopy

The depth of information is defined as the distance below the surface of a specimen from which information is contributed at a specific resolution. A simplified model of photoemission is used to explore the relationship between electron escape depths and depth of information in photoelectron microscopy (PEM or photoemission electron microscopy). The depth of information is equal to the escape depth when the escape depth is small relative to the instrument resolution. When the escape depth is large compared to the instrument resolution or when information is carried for example by reflected light, the image consists of well resolved surface detail at the instrument resolution and dimmer, more diffuse, images of detail below the surface. Thus the same sample can exhibit different depths of information depending on the image details of interest. Other mechanisms of transmitting information to the surface, for example induced topography, are discussed, and experimental examples are given.

[Endoscopic and histological alterations of the gastric mucosa in patients with chronic renal insufficiency (author's transl)]

Biopsies of mucosa from all regions of the stomach were obtained with endoscopic guidance from two groups of people. One group consisted of 80 patients who suffered from chronic renal insufficiency in various stages and had not yet been dialysed. The other group consisted of 80 healthy individuals. Both groups had the same age distribution. Histological examinations of the biopsies did not reveal significant differences between the two groups. The same was true for macroscopic examinations of stomach and duodenum. Changes indicating a so called "uremic gastritis" were not observed.

[The exocrine pancreatic function in chronic renal insufficiency (author's transl)]

46 patients, who suffered from chronic renal insufficiency (serum creatinine: 1,4-14,9 mg%) and had not yet been dialysed, were given a secretin-pancreozymin-test. Statistical evaluation of the results and comparison with a healthy reference group showed amylase secretion, total secretory volume and bicarbonate secretion to be significantly reduced in patients with serum creatinine levels above 4,0 mg%. No signs of secondary hyperparathyroidism (laboratory data, osseous changes) were observed. Blood base excess and increased serum creatinine levels were significantly related. Together with influences of low protein diet metabolic acidosis going along with chronic renal insufficiency is consequently considered to be the pathogenic factor responsible for alterations in the exocrine function of the pancreas and for the occurrence of chronic pancreatitis.

[The significance of the cytochemical adenosine triphosphatase reaction for the diagnosis of benign monoclonal gammopathy (author's transl)]

In 26 cases with benign monoclonal gammopathy the cytochemical activity of the adenosintriphosphatase (ATPase) in the plasmocytes of bone marrow smears was studied. 15 cases showed a decreased and 11 patients showed normal proportions of ATPase positive cells, indicating that the impairment of ATP-ase is non-specific for the diagnosis of multiple myeloma.