Response properties of FM-FM combination-sensitive neurons in the auditory cortex of the mustached bat

For echolocation, the mustached bat, Pteronotus parnellii rubiginosus, emits orientation sounds (pulses) and listens to echoes. Each pulse is made up of 8 components, of which 4 are constant frequencies (Cf 1.4) and 4 are frequency-modulated (FM 1-4). Target-range information, conveyed by the time delay of the echo FM from the pulse FM, is processed in this species by specialized neurons in a part of the auditory cortex known as the FM-FM area. These cortical neurons are responsive to pulse-echo pairs at specific echo delays. The essential components in the sound pair include the pulse FM1 followed by an echo FMn (n = 2, 3 or 4). Downward sweeping FM1-FMn sounds that are similar to those the animal naturally hears during echolocation are the most effective in evoking facilitative responses. Most FM-FM neurons, however, still exhibit facilitative responses to stimulus pairs consisting of upward sweeping FM sounds and/or pure tones at frequencies found in FM sweeps. The magnitude of facilitation is altered by changes in echo rather than pulse amplitude. Neurons characterized by shorter best delays (or echoes from closer targets) do not require larger best echo amplitudes for facilitation.

Immunological response of regional lymph nodes after tumor cryosurgery: experimental study in rats

Seven days after inoculation of metastasizing rat mammary tumor No. 1 into the thigh of 5-week-old female Sprague-Dawley rats, the tumor was treated cryosurgically by two-cycle freezing and by contact methods at -170 degrees C. Weights of the thymus and the spleen, histological findings of the lumbar lymph nodes, phytohemagglutinin (PHA)-induced blastogenesis of lymphocytes obtained from the lumbar lymph nodes and peripheral blood, and resistance rate to tumor rechallenge were examined 1, 3, 6, 10, and 17 week(s) after cryosurgery, with the following results: Thymus weight gradually decreased by 3 weeks after cryosurgery, while spleen weight increased by 1 week, recovering the preoperative level at 6 weeks. Paracortical hyperplasia of the lumbar lymph nodes markedly increased in 1 week and sinus histiocytosis increased after 3 weeks, both remaining at high values until 10 weeks, while germinal center hyperplasia showed a high value at 3 weeks and thereafter decreased gradually. PHA-induced blastogenesis of the lumbar lymph nodes significantly increased 1 week after cryosurgery and remained at its high value until 10 weeks. PHA-induced blastogenesis of peripheral lymphocytes showed the lowest value at 3 weeks and then significantly increased at 6 weeks. Resistance rate to rechallenge showed the lowest value at 3 weeks, reaching the highest level 10 weeks after cryosurgery. From the above results, it was suggested that anti-tumor immunity (resistance to tumor rechallenge) induced by cryosurgery was at the lowest level at 3 weeks after cryosurgery, and gradually increased starting at 6 weeks.(ABSTRACT TRUNCATED AT 250 WORDS)

[Immunological response of regional lymph nodes after cryosurgery in rats]

At 7 days after MRMT-1 inoculation at the thigh of 5 week-old female SD rats, the tumor was treated cryosurgically by 2 cycle freezing, contact method at -170 degrees C. Weights of thymus and the spleen, histological findings of lumbar lymph nodes, PHA-induced blastogenesis of lymphocytes obtained from lumbar lymph nodes or peripheral blood, and resistance rate to tumor re-challenge were examined at 1, 3, 6, 10 and 17 week(s) after cryosurgery. Following results were obtained. (1) Weight of the thymus gradually decreased by 3 weeks after cryosurgery, while that of the spleen increased by 1 week, recovering the preoperative level at 7 weeks. (2) Paracortical hyperplasia of lumbar lymph nodes markedly increased at 1 week and sinus histiocytosis increased after 3 weeks, both keeping their high values till 10 weeks, while germinal center hyperplasia showed a high value at 2 weeks, thereafter decreasing gradually. (3) PHA-induced blastogenesis of lumbar lymph nodes significantly increased at 1 week, keeping its high value till 10 weeks. (4) PHA-induced blastogenesis of peripheral lymphocytes showed the lowest value at 3 weeks, then significantly increasing at 6 weeks. (5) Resistance rate to re-challenge showed the lowest value at 3 week, reading the highest level at 10 weeks after cryosurgery. From the above results, it was suggested that anti-tumor immunity induced by cryosurgery was at the lowest level at 3 weeks, and gradually increased starting at 6 weeks. Augmentation of helper T cell and cytotoxic T cell functions at the regional lymph nodes was also suggested to occur from 1 week to 10 weeks after cryosurgery.

[Cytotoxicity of interleukin 2-induced lymphocytes and effects of serum immunosuppressive factors]

IL2-induced lymphocytes (IIL) obtained from normal subjects were examined as to a possibility for induction of tumor-specific killer cells. Moreover, effects of serum on their cytotoxic activity were observed. The IIL which were pre-sensitized with mitomycin C-treated MKN-28 (IILM), showed a markedly increased cytotoxic activity against MKN-28. The IIL which were either pre-cultured with PHA or not, showed augmentation of cytotoxic activity against various human cancer cell lines, although their cytotoxic activity against MKN-28 was lower than that of IILM. The cytotoxic activity of IILM was suppressed by addition to the medium of non-specific immunosuppressive factors (IAP, ferritin, alpha-fetoprotein) or of various sera obtained from gastric cancer patients, in whom histological diagnosis was tub1, por or sig, but the suppression to the IILM activity was significantly milder than that to the activity of peripheral lymphocytes. The degree of suppression by tub1 serum was significantly higher than that by the serum from por or sig. When tub1 serum was added to the medium during pre-sensitization, the cytotoxic activity of IILM against MKN-28 was reduced significantly. However, addition of por or sig serum showed no significant reduction in cytotoxic activity of IILM.

Hormonal effects and the control of gluconeogenesis from sorbitol, xylitol and glycerol in perfused chicken liver

Addition of sorbitol or xylitol to perfused chicken liver caused a biphasic increase in the rate of glucose production. The second increase correlated with a decrease in the lactate to pyruvate ratio. Increased glucose production in response to the addition of glycerol was not biphasic. Aminooxyacetate inhibited both the inherent second increase in glucose production and stimulatory effects of alanine and pyruvate. The stimulatory effects of norepinephrine and glucagon on gluconeogenesis from sorbitol decreased in the presence of methylene blue. Only the stimulatory effect of norepinephrine was inhibited by aminooxyacetate.

[Clinical study on serum immunosuppressive factors in gastric cancer patients--with special reference to preoperative IAP values and the influence of surgical stress]

Serum IAP values were measured preoperatively in 83 gastric cancer patients. The levels were significantly higher in cases of total, stage III and IV, n (+) and non-curative resection than in normal subjects, stage I, n (-) and curative resection. There was a significant correlation between IAP on the one hand, and IgG FcR (+) T cell, alpha 2-globulin and CEA on the other. OK-432 was serially administered pre- and postoperatively (A) and only postoperatively (B). IAP was examined at one, two and four weeks postoperatively, and the findings were compared. It was increased markedly at one week and was slightly reduced at two and four weeks. These changes in IAP showed no significant differences between groups A and B.

Chromophores in the extraretinal photoreceptor (pineal organ) of teleosts

We have demonstrated, using a highly sensitive high performance liquid chromatography technique, that the pineal organ (epiphysis cerebri) of the rainbow trout contains both 11-cis-retinal and 11-cis-3-dehydroretinal. These compounds were assumed to be the chromophores of pineal photopigments, because they were isomerized to all-trans forms by light-adaptation. The quantity of chromophores in the dark-adapted pineal organ was extremely low (9.2-29.1 pmol/pineal), corresponding to approximately 1/300-1/1000 of that of the retina.

Genotoxicity of ptaquiloside, a bracken carcinogen, in the hepatocyte primary culture/DNA-repair test

The genotoxicity of ptaquiloside (PT), recently isolated from bracken fern and shown to be carcinogenic, was examined by means of the hepatocyte primary culture/DNA-repair test. PT elicited clear unscheduled DNA synthesis with a dose-response effect. The result indicates that PT is a genotoxic carcinogen.

Alteration of histamine, serotonin and primary prostaglandin in case of diarrhea induced by endotoxin and gastrointestinal absorption of drug

Effects of endotoxin on the motility, the permeability of mesenteric blood vessel and endogenous substances (electrolyte (Na, K), histamine, serotonin and primary prostaglandin) in the small intestine of mice were investigated. Diarrhea was induced by intraperitoneal injection of Salmonella typhosa endotoxin in mice. It is suggested that the diarrheal action of endotoxin is due to the acceleration of intestinal motility and/or the facilitation of mesenteric blood vessel permeability. On the other hand, from the observation of blood concentration of acetaminophen and sulfisoxazole, inhibition of drug absorption was suggested in cases of diarrhea induced by endotoxin. This inhibition of gastrointestinal absorption is due to the delay of the gastric emptying rate, the increase of intestinal transit time of drug in the absorption site and the acceleration of mesenteric blood vessel permeability. Then it is conceivable that these actions may be mediated by biogenic amines (serotonin and histamine) and primary prostaglandins.

Reproduction of acute bracken poisoning in a calf with ptaquiloside, a bracken constituent

Acute bracken fern toxicity in a calf was reproduced with ptaquiloside, a norsesquiterpene glucoside, isolated from the boiling water extract of bracken fern. Ptaquiloside was dissolved in 500 ml of saline and administered by drench at increasing dosages for six days out of every seven for the following periods: 400 mg/day for 24 days, 800 mg/day for 14 days and 1600 mg/day for four days. Neutrophilic granulocytes began to decrease markedly around 50 days after the start of the experiment, and granulocytopenia continued for a further 35 days until the autopsy, despite the discontinuance of ptaquiloside administration. Thrombocytes showed a relatively slow depression and reached 1 X 10(5)/mm3 at the lowest level. The calf was autopsied 86 days after the start of administration of ptaquiloside. Sternal bone marrow was found to be mostly replaced with fat marrow and only small foci of erythropoietic cells and a small number of megakaryocytes remained.

Carcinogenicity in rats of ptaquiloside isolated from bracken

The nature of the carcinogen present in bracken fern has not yet been elucidated. Very recently, we succeeded in isolating ptaquiloside, a novel norsesquiterpene glucoside of the illudane type, from bracken. Ptaquiloside was shown to be a carcinogenic principle of bracken fern. It induces mammary cancer and multiple ileal tumors in high incidences when given orally to female Sprague-Dawley rats.

[The metabolic changes and nutritional management following radical surgery of esophageal cancer and total gastrectomy]

The metabolic changes after major surgery such as esophagectomy and total gastrectomy are remarkable. Postoperative levels of plasma catecholamines and glucagon were significantly higher in major surgery than those in the other operations (distal gastrectomy, cholecystectomy, mastectomy, etc). As the consequence of these hormonal changes, resting metabolic expenditure (RME) increased up to 30-40% above the predicted basal metabolic expenditure and blood glucose elevated to a high level. The relationships between RME, N-balance and energy intake after major surgery indicated that the intake of non-protein energy expenditure equal to RME was necessary in order to maintain N-balance. For the administration of enough energy after major surgery, TPN solution composed of glucose 180-240g, fructose 90-100g, xylitol 30-40g and amino acids 68-91g (the approximate weight ratio of G, F and X is 4: 2: 1) was developed since 1975 and in some cases, lipid solution was added as non-protein energy source. This solution was infused immediately after operation and no metabolic complications (hyper glycemia, acidosis, etc) were observed. This nutritional therapy has maintained the nutritional state of postoperative patients and improved our operative results. There are, however, many problems in the nutritional managements of the patients with severe complications and after the discharge of hospital. In the future, special nutritional therapy for these cases should be progressed.

Comparison of actual survivorship after treatment with survivorship predicted by actual tumor-volume doubling time from tumor diameter at first observation

The predicted survival time of 56 patients with lung cancer was calculated using Geddes ' nomogram for tumor diameter and tumor doubling time. The predicted survival time correlated favorably with the actual survival time. For many patients with resection the actual survival time far exceeded the predicted survival time; thus, the latter may be very useful as a control for the evaluation of all therapies of lung cancer.

Hyperplastic nodules of the liver induced in rats fed bracken diet

Hyperplastic nodules (HN) of the liver were induced in Charles River Sprague-Dawley rats (CD rats) and ACI rats fed a diet containing 30% bracken for 260 and 180 days, respectively. HN were also induced in high incidence in CD rats fed a diet containing the carcinogenic fractions of bracken extract.

Effect of an intracellular calcium antagonist (TMB-8) on carbamylcholine-induced amylase release from dispersed rat pancreatic acini

During 10-min incubation with increasing concentrations of carbamylcholine (carbachol), amylase release from dispersed rat pancreatic acini increased, became maximal at 2 X 10(-6)M and then decreased. In the concentration range of 10(-7)M to 10(-4)M, 8-(N,N-diethylamino)-octyl 3,4,5-trimethoxybenzoate hydrochloride (TMB-8) caused a dose-dependent inhibition of amylase release induced by a submaximal concentration of carbachol. No inhibitory effect was observed on basal and secretin-stimulated amylase release. TMB-8 showed a significantly greater ability of blocking the action of carbachol than verapamil and diltiazem. TMB-8 could reverse the submaximal stimulation of amylase release caused by supramaximal concentrations of carbachol to a maximal stimulation, while verapamil and diltiazem could not. These results confirm the hypothesis that mobilization of intracellular calcium is the primary step in the action of carbachol on pancreatin acinar cells and contributes to the submaximal secretory response of acinar cells induced by high concentrations of carbachol.

Actions of picrotoxinin and related compounds on the frog spinal cord: the role of a hydroxyl-group at the 6-position in antagonizing the actions of amino acids and presynaptic inhibition

The frog spinal cord has been used to test the effects of naturally occurring picrotoxane compounds (picrotoxinin, picrotin, tutin and coriamyrtin) and semisynthetic ones (6-acetylpicrotoxinin and anhydropicrotin) on the electrical activities of dorsal and ventral roots and on amino acid-induced depolarizations of primary afferent terminals. Picrotoxinin, tutin and coriamyrtin (10(-5)-3 X 10(-5)M), which have a free hydroxyl group at the 6-position, caused a gradual depolarization in both ventral and dorsal roots. The depolarizations were accompanied by a reduction in the size of the dorsal root potential (DR-DRP), dorsal root reflex (DR-DRR) and ventral root potential (DR-VRP) and by an augmentation of the first spike potential and polysynaptic components in the ventral root reflex (DR-VRR). 6-Acetylpicrotoxinin (10(-5)-3 X 10(-5)M) caused a slight hyperpolarization in both roots, and this hyperpolarization was accompanied by the augmentation of DR-DRP, DR-VRP and DR-VRR. The DR-DRR was reduced or abolished by the compound. Picrotoxinin, tutin and coriamyrtin reduced gamma-aminobutyric acid (GABA)-, beta-alanine- and taurine-induced depolarizations of primary afferent terminals. 6-Acetylpicrotoxinin showed almost the same degree of inhibition of beta-alanine and taurine as did picrotoxinin, but the GABA- antagonizing action of the compound was significantly weaker than was that of picrotoxinin. Picrotoxinin, tutin, coriamyrtin and 6-acetylpicrotoxinin all blocked presynaptic inhibition of the first spike potential caused by antidromic conditioning stimulation. 6 The present results suggest that the hydroxyl group at the 6-position of picrotoxane compounds are important for antagonism of the effects of GABA, but not of beta-alanine and taurine and for the blocking action of the presynaptic inhibition in the frog spinal cord.