Delayed memory dysfunction by transient hypoxia, and its prevention with forskolin

Rats exposed to 40 min hypoxia 3 h before a one-trial learning passive avoidance task showed impaired memory retention 24 h later. this model was used to assess the ability of forskolin to restore the delayed memory dysfunction. Significant amelioration of memory retention was observed when forskolin (500 micrograms/kg, i.p.) was injected just after hypoxia. Forskolin is suggested to enhance cerebral blood flow and to facilitate memory function through the action of increased cyclic adenosine monophosphate (cAMP).

Effect of vanadate on cartilage-matrix proteoglycan synthesis in rabbit costal chondrocyte cultures

The effect of vanadate on proteoglycan synthesis by cultured rabbit costal chondrocytes was examined. Rabbit chondrocytes were seeded at low densities and grown to confluency in medium supplemented with 10% fetal bovine serum, and then the serum concentration was reduced to 0.3%. At the low serum concentration, chondrocytes adopted a fibroblastic morphology. Addition of 4 microM vanadate to the culture medium induced a morphologic differentiation of the fibroblastic cells to spherical chondrocytes, and increased by two- to threefold incorporation of [35S]sulfate and [3H]glucosamine into large, chondroitin sulfate proteoglycans. The stimulation of incorporation of labeled precursors reflected real increases in proteoglycan synthesis, in that chemical analyses showed increases in the accumulation of macromolecules containing hexuronic acid and hexosamine in vanadate-maintained cultures. However, vanadate had only a marginal effect on [35S]sulfate incorporation into small proteoglycans and [3H]glucosamine incorporation into hyaluronic acid and chondroitinase AC-resistant material. These results provide evidence that vanadate selectively stimulates the synthesis of proteoglycans characteristically found in cartilage by rabbit costal chondrocyte cultures.

Use of 4-bromomethyl-7-methoxycoumarin for derivatization of pyrimidine compounds in serum analysed by high-performance liquid chromatography with fluorimetric detection

Derivatization of the pyrimidine nucleobases and nucleosides with 4-bromomethyl-7-methoxycoumarin was studied with the aim of developing a sensitive and selective column liquid chromatographic method for these substances in serum. The labeling reactions and the nature of derivatives are discussed, together with the chromatographic properties of these derivatives. The derivatives are stable for at least several weeks. Typical detection limits are 50 pg for inosine, 150 pg for uridine, 50 pg for uracil, 50 pg for thymine and 100 pg for fluorodeoxyuridine, respectively. Within-day coefficients of variation averaged 5.0% for the stored-frozen serum pools; the mean day-to-day value was 5.2%. Thirty samples could be processed per working day.

Cold-labile hemolysin produced by limited proteolysis of theta-toxin from Clostridium perfringens

A nicked toxin whose hemolytic activity is temperature dependent was obtained by limited proteolysis of theta-toxin (Mr 54,000) with subtilisin. The nicked toxin (C theta) is a complex of two fragments: the N-terminal fragment (Mr 15,000) with basic isoelectric point and the C-terminal fragment (Mr 39,000) with the single cysteinyl residue of the toxin whose reduced form is essential for the hemolytic activity. C theta hemolyzes erythrocytes only at temperatures above 25 degrees C, whereas the native toxin hemolyzes them even at 10 degrees C. At temperatures below 25 degrees C, C theta does not hemolyze them although it does bind to membrane cholesterol and although no distinct difference was observed between the secondary structure of C theta and that of native toxin. It was found that C theta binds to the cells only in a reversible manner at low temperature, while the native one binds irreversibly to the cells within 10 min, which explains the cold lability of C theta on hemolysis. The structural basis of the cold lability was discussed through comparison of C theta with another nicked derivative of theta-toxin that was also obtained.

Ultrastructural correlation of specular microscopy in retinoblastoma

A patient with monocular retinoblastoma was examined with the wide-field specular microscope before undergoing enucleation. An unusual image on the corneal endothelium consisted of irregular oval dark structures within which bright reflections formed a lacy network. Light and electron microscopy confirmed these structures to be clusters of retinoblastoma cells adherent to the endothelium. These findings suggest that the specular microscope may aid in the diagnosis of intraocular tumors.

Pathway of the blink reflex in the brainstem of the cat: interneurons between the trigeminal nuclei and the facial nucleus

Blink reflex responses evoked by electrical stimulation of the supraorbital nerve were examined using cats and the pathway of the blink reflex in the brainstem was elucidated. Both early response (ER) and late response (LR) were mediated by the main sensory trigeminal nucleus and the spinal trigeminal nucleus. However, a lesion of the main sensory trigeminal nucleus had less effect on the blink reflex than a lesion of the spinal trigeminal nucleus. The ER was mediated not only by the shorter disynaptic pathway of 3 neurons through the trigeminal nerve, the trigeminal nuclei and the facial nucleus but also by a polysynaptic pathway of 4 neurons. The interneurons were located between the trigeminal nuclei and the facial nucleus. Some of these interneurons participated in the production of both ER and LR. The area of the brainstem responsible for ER and LR of the blink reflex was the reticular formation from the rostral part of the medulla to the pons except the medial area around the median sulcus. The LR interneurons were distributed more widely than the ER interneurons.

Neurogenic pulmonary edema associated with ruptured intracranial aneurysm: case report

A case of ruptured distal anterior cerebral artery aneurysm associated with neurogenic pulmonary edema is presented. It is suggested that this association should not be accepted as a "taboo" for radical intervention followed by a proper management of ventilation with positive end-expiratory pressure to maintain the anesthetic condition. Cardiorespiratory control is essential in cases of pulmonary edema with ruptured aneurysm. Decompression and evacuation of blood clot surrounding the hypothalamus could subdue the hyperadrenosympathetic discharge that may cause neurogenic pulmonary edema.

Rabbit thymus gangliosides: species- and organ-specific distribution, age-dependence and their cell biological significance

Gangliosides of thymuses from rabbit, mouse, rat, calf, and man were analyzed. The ganglioside compositions of the thymuses showed species specificities, and the compositions of the species other than the rabbit were found to be markedly different from that of the rabbit, which contained characteristically substantial amounts of IV3NeuGc-nLc4Cer and VI3NeuGc-nLc6Cer (Iwamori, M. & Nagai, Y. (1981) Biochim. Biophys. Acta 665, 214-220). The inter-species differences in the thymus ganglioside compositions were not remarkable in the 8 mouse and 2 rabbit strains examined. Rabbit thymocytes, but not those of mouse and rat, were lysed with human Hanganutziu-Deicher serum in the presence of guinea pig complement, reflecting the high content of gangliosides containing N-glycolylneuraminic acid in rabbit thymus. As to age-dependent changes of gangliosides in rabbit thymus and spleen, the concentrations gradually decreased with age, while the molar ratio of total gangliosides to total phospholipids was constant in the spleen throughout life and in the thymus at 3, 4, and 6 weeks of age. It was noted that old (180 weeks of age) rabbit thymus, which is occupied largely by fat tissue, still contained a significant amount of neolactoseries gangliosides.

Fluorescence determination of 5-fluorouracil and 1-(tetrahydro-2-furanyl)-5-fluorouracil in blood serum by high-performance liquid chromatography

Fluorescence derivatization of 5-fluorouracil (5-FU) and 1-(tetrahydro-2-furanyl)-5-fluorouracil (ftorafur, FT) with 4-bromomethyl-7-methoxycoumarin using 18-crown-6 as a catalyst is studied with aim of developing a sensitive and selective liquid chromatographic method. 5-FU and FT form virtually substituted derivatives which possess maxima in their fluorescence emission spectra near 400 nm. These derivatives are separated by thin-layer chromatography and high-performance liquid chromatography to confirm the completion of reaction. For the determination of 5-FU and FT in serum, the reversed-phase high-performance liquid chromatographic separation of the derivatives is studied with a C13 column. This chromatography is of importance for the accurate determination of 5-FU and FT, which are, respectively, an important antitumour agent for the treatment of solid tumours in clinical medicine and a masked form of 5-FU generated in vivo.

[Evaluation of radiotherapy combined with surgery for esophageal carcinoma]

The role of adjuvant radiotherapy combined with surgery for esophageal carcinoma was discussed. To improve the surgical results, pre- and/or postoperative irradiation (total doses was 5000 rads) were performed. The patients with esophageal carcinoma were divided into two groups by random selection. Eight patients of group A underwent pre- and postoperative radiotherapy and 11 patients of group B underwent postoperative radiotherapy alone. Dose of preoperative irradiation was 3000 rads in each patients of group A. Adjuvant chemotherapy of FT-207 (600mg/day) was also administered in all of these patients for long postoperative duration over 3 months. The incidence rate of the most neighbouring regional lymph nodes metastasis in group A showed high values as compared to that in group B. But the metastatic rate of other regional lymph nodes showed no significant difference between group A and group B. In comparison of prognosis between group A and group B, the patients of group A were survived well compared with the patients of group B, and postoperative distant metastasis was recognized frequently in the patients of group B. From these results, the treatment results were better in the group of pre- and postoperative irradiation than in the group of postoperative irradiation.

Moyamoya disease associated with craniopharyngioma

A case of coexisting moyamoya disease and craniopharyngioma in an 8-year-old boy is reported. The patient had been suffering from recurrence of transient right hemiparesis with headache and vomiting during the three years before admission. After the diagnosis of both moyamoya disease and craniopharyngioma, evacuation of the cystic fluid of the craniopharyngioma, encephalomyosynangiosis , and internal irradiation through an Ommaya drainage system were carried out. The symptoms gradually improved after these procedures. The relation of moyamoya disease to craniopharyngioma is discussed. We consider that internal irradiation is one of the best means of treatment for a cystic craniopharyngioma associated with moyamoya disease.

Parallel but separate release of catecholamines and acetylcholinesterase from stimulated adrenal chromaffin cells in culture

A pharmacological study was made of the effects of veratridine and lasalocid on the release of catecholamines, acetylcholinesterase (AChE) and dopamine-beta-hydroxylase (DBH) from cultures of isolated bovine adrenal chromaffin cells. Exposure of the cultures to veratridine resulted in concomitant release of catecholamines and AChE into the external medium in a dose-dependent and Ca2+-dependent manner. A Ca2+ ionophore, lasalocid, also produced a dose-dependent and parallel release of both catecholamines and AChE. The release of the two components was accompanied by release of DBH. The present results provide pharmacological evidence for a parallel release of catecholamines, AChE, and DBH from cultured adrenal chromaffin cells, and the stoichiometry of the release evoked by different secretagogues suggests that AChE and catecholamines are released from different cellular compartments.

Thrombin-induced platelet reactions: effect of substrates and inhibitors on binding of thrombin and serotonin release

Binding of 125I-thrombin to platelets and subsequent serotonin release were confirmed. The binding of unaltered thrombin to platelets was also measured by a new technique using a chromogenic substrate (S-2238). As compared to 125I-thrombin, this method gave similar constants for binding to the high affinity binding site, but lower for binding to the low affinity binding site. Furthermore, the results suggest that the platelets have two classes of independent binding sites. Substrates and inhibitors of thrombin inhibited thrombin induced serotonin release, suggesting that the release reaction depends on the proteolytic activity of thrombin. The serotonin release was more inhibited than the binding of thrombin, suggesting that the platelet binding site and the active site of thrombin are located in different parts of the thrombin molecule.

Reactivated response of blink reflex in the cat

Three reflex responses in the orbicularis oculi muscles were observed by electrical stimulation of the trigeminal nerve in lightly anesthetized or conscious cats. The third response, following the first and second responses, was concluded as being a "reactivated response" of the blink reflex as it was set up by the trigeminal afferent input evoked by the palpebral movement of the preceding blink. The reasons for this were as follows: 1) the third response disappeared on administration of muscle relaxants and 2) was enhanced by touching the palpebral hair; 3) the palpebral movement activated the afferent discharges of the trigeminal exteroceptors which were strong enough to yield the reflex responses and 4) the latency of the first reflex response by the palpebral movement corresponded to the time lag between the preceding large reflex response and the third response; 5) the third response was hardly suppressed at all until the first response disappeared over a period of maximum reflex suppression following the conditioned stimulation of the trigeminal nerve.

Cranial chondromyxoid fibroma. Case report

A case of chondromyxoid fibroma of the frontal bone in a 15-year-old girl is presented. This is a benign tumor, but should be excised widely enough to include a rim of normal bone, otherwise it may recur or even undergo malignant transformation.

An easy quantitative cytotoxicity assay using a Coulter Counter

A rapid and reproducible cytotoxicity assay using an electronic particle counter, such as a Coulter Counter, is described. With anti-BAtheta antiserum and mouse thymocytes as target cells, comparable, but more objective results than those by the ordinary dye exclusion method were obtained in a short time. The procedure is very simple: Cells in a plastic multi-well plate are first exposed to antibody and complement or other cytolytic conditions and then Pronase E is added to each well to digest dead cells completely. Then the nuclei of remaining viable cells are liberated from the cytoplasm and cell debris by solubilization with Zap-Oglobin and counted in the counter. Under these conditions, contaminating erythrocytes do not cause interference, because they are completely solubilized with Zap-Oglobin. This technique should be useful for measurements on numerous samples, such as in monitoring chromatograms of cytotoxic activity and titrating antibody and complement.

Hip abnormalities in cerebral palsy: radiological study

A total of 237 hips of children with cerebral palsy were examined annually for three years. The severely involved spastic children and those who had never stood were more susceptible to hip abnormality. Apparent coxa valga (whose phenotype consists more of anteversion and less of true coxa valga) is closely related to the hip abnormality.