Biomedical subjects

T Kasai

Publications and source records attributed to T Kasai.

At least 163 records · Page 9Linked to original sources

PubMed1996

CK-independent increases in pancreatic secretion induced by dietary protein in chronic BPJ-diverted rats.

Previously, we demonstrated that, in rats with chronic bile-pancreatic juice (BPJ) diversion, pancreatic enzyme secretion was increased after feeding animals a 25% casein fat-free diet. We determined whether cholecystokinin (CCK) or the cholinergic pathway is associated with the response of pancreatic secretion after protein ingestion in the diverted rats, using a potent CCK antagonist, MK-329 or FK-480, and a cholinergic blocker, atropine. Secretion rates of chymotrypsin and trypsin in the fasting state were very high 7 days after a BPJ diversion, and the hypersecretion of the proteases was markedly reduced with an injection of MK-329, FK-480, or atropine and was further reduced by combined injection of FK-480 and atropine. The lowered secretion of the proteases in CCK-antagonized rats was increased after oral feeding of a protein diet and after a duodenal instillation of some protein sources, especially hydrolysate of guanidinated casein (HGC). The CCK-independent increases by HGC instillation are completely depressed by atropine. In rats treated with only atropine, the lowered secretion tended to be increased by a duodenal instillation of HGC. Increases in secretion after an administration of the protein source in CCK-antagonized rats were not affected by bestatin, an inhibitor of brush-border peptidases. We conclude that the stimulatory effects of dietary protein on the pancreatic enzyme secretion partially do not depend on CCK in chronic BPJ-diverted rats and that the CCK-independent increase is atropine sensitive.

Animals↗

PubMed1996

Inhibitory effect of dietary wheat bran on formation of aberrant crypt foci in rat colon induced by a single injection of 1,2-dimethylhydrazine.

The frequency of appearance of aberrant crypt foci (ACF) in the distal colon was significantly lower in rats fed a high fiber (20% wheat bran) diet than in those fed a fiber-free one at 4 weeks after a single injection of 1,2-dimethylhydrazine (DMH, 20 mg/kg), although crypt/ACF was high in the former relative to the latter. This result suggests that dietary wheat bran effectively serves as a regulator of ACF frequency at early stages after DMH injection.

1,2-Dimethylhydrazine↗

PubMed1996

Impaired pancreatic acinar sensitivity to cholecystokinin but not to carbachol in rats with chronic bile pancreatic juice diversion.

Changes in the sensitivity and responsiveness to CCK and cholinergic stimuli were examined in isolated pancreatic acini prepared from 7-day BPJ-diverted rats. The sensitivity to CCK was lower in BPJ-diverted rats than in the control rats, but the sensitivity to the cholinergic agonist, carbachol, was not changed. These results suggest that the contribution of the cholinergic pathway to pancreatic enhancement by feeding dietary protein can be increased after chronic BPJ diversion.

Animals↗

PubMed1996

Polymerization degree of oligomethionine to determine its bioavailability when added to a low-protein diets.

Oligo-L-methionine ethylester (OMOEt) prepared by the papain-catalyzed oligomerization of L-methionine ethylester (MetOEt) is a mixture of pentamer to dodecamer and has nearly the same supplementary effect as free methionine (Met) for the growth of rats when added to a low casein diet, but its supplementary effect to a low-soy protein isolate (SPI) diet is not consistent and depends on the degree of polymerization. Rats were fed for 2 wk with an 8% casein or 10% SPI diet supplemented with 0.3% L-Met, each chemically synthesized MetnOEt with a polymerization degree (n) of 6, 7, 8, or 9, or with OMOEt prepared by papain-catalyzed polymerization of MetOEt. Met6OEt, Met7OEt, and Met8OEt had nearly the same supplementary effect on the growth of rats, as did free Met, both with the 8% casein and 10% SPI diets. The supplementary effect of Met9OEt was not significantly lower than that of Met when added to the 8% casein diet, but was significantly lower when added to the 10% SPI diet. The digestibility of Met9OEt supplemented to the 8% casein and 10% SPI diets was 50.5% and 35.6%, respectively. It appears likely that there is a gap in the bioavailability of oligomethionine between the octamer and nonamer when added to a low-protein diet, probably due to the rigidity of the structure increasing with the polymerization degree by alpha-helix formation. Although the differences in absorption rate of Met from OMOEt for a short time after feeding has been related to the different effects of supplemented OMOEt, the absorption rate of OMOEt for 30 min after feeding was not considered to be the main cause of the differential effects of OMOEt in this experiment.

Animals↗

PubMed1996

An increase in cortical excitability with no change in spinal excitability during motor imagery.

During motor imagery, to estimate changes in excitability of flexor carpi radialis muscle motoneurons of the spinal and cortical levels, electrical stimuli for recording H-reflex and transcranial magnetic stimulation (TMS) for recording motor evoked potentials (MEPs) were used. In the absence of movement or detectable EMG activity during motor imagery, there was an increase in cortical excitability with no change in spinal excitability.

Adult↗

PubMed1996

Cyclo (LL-dimethionine) is not utilized by rats as a methionine source.

A low casein diet supplemented with 0.2-0.3% L-methionine promotes growth in rats, although it causes liver fat accumulation. Oligo-L-methionine on the other hand, prepared by papain-catalyzed oligomerization of L-methionine ethylester, stimulates growth in rats without causing liver fat accumulation, when added to a 8% casein diet. Oligo-L-methionine is a mixture of oligomers, with a oligomerization degree of 5 to 12, and is hydrolyzed very slowly by pancreatic juice and everted gut rings of rats. A methionine derivative, cyclo (LL-dimethionine), was examined in this study as it is hydrolyzed and/or absorbed very slowly from the intestinal tract and it was expected to be utilized as a methionine source without causing liver fat accumulation, when added to a low casein diet. It consists of two methionine residues linked together by two cis-peptide bonds and, therefore, is expected to be hydrolyzed and/or absorbed very slowly from intestinal tract. However, although cyclo (LL-dimethionine) was absorbed slowly from the intestinal tract, it was not utilized by rats as a methionine source, when added to 8% casein.

Animals↗

PubMed1996

Administration of anti-asialo GM1 serum increases aberrant crypt foci induced by 1,2-dimethylhydrazine in the large bowel of rats.

We investigated the influence of the administration of anti-asialo GM1 antibody on aberrant crypt foci (ACF) formation induced by a single injection of 1,2-dimethylhydrazine (DMH). At four weeks after the injection of DMH (20 mg/kg body weight), the number of ACF and aberrant crypts were counted. Most ACF appeared in the distal large bowel, accounting for approximately 60% of the total ACF in both groups. Rats administered anti-asialo GM1 had significantly more ACF in the distal colon, the rectum and the total large bowel as compared to control rats. A similar tendency was observed for the number of aberrant crypts. The increased number of ACF resulting from the administration of anti-asialo GM1 was not accompanied by the enlargement of ACF size in every part of the colon. This study demonstrated that the administration of anti-asialo GM1 at the initiation stage leads to an increase in ACF as well as aberrant crypts in the distal colon, rectum and total large bowel probably via the suppression of natural killer cells.

1,2-Dimethylhydrazine↗

PubMed1996

Nitrite/nitrate (NOx) and sFas antigen levels in patients with multiple organ failure.

We assessed the plasma levels of nitrite/nitrate (NOx) and soluble Fas antigen (sFas) in patients with multiple organ failure (MOF). The NOx levels showed high levels in MOF patients with sepsis and without infection. A significant difference was not seen between the MOF patients complicated by sepsis and uncomplicated by infection, although the NOx levels in the former group tended to be higher. There was a significant correlation between NOx levels and sFas levels in MOF patients. Both sFas and NOx levels were high during MOF, and rapidly decreased when MOF was relieved. These findings suggest that sFas and NOx contribute to the development of MOF.

Humans↗

PubMed1996

Changes in adhesion molecule levels in sepsis.

We measured the levels of soluble intercellular adhesion molecule-1 (sICAM-1), CD11a, CD11b, CD18, endotoxin, and various inflammatory cytokines to clarify the relationship between adhesive molecules and cytokines in sepsis. We studied 21 patients with sepsis (sepsis group) and 13 patients with trauma not complicated by infection (trauma group). The mean sICAM-1 level was significantly higher in the sepsis group than in the trauma group. No significant difference was observed in the CD11a, CD11b, and CD18 levels between the two groups. The sICAM-1 levels significantly correlated with the levels of endotoxin, tumor necrosis factor alpha (TNF-alpha), and IL-8, but CD11a, CD11b, and CD18 levels did not correlate with endotoxin or cytokine levels. These findings suggest that ICAM-1 production is induced by endotoxins and cytokines produced in excess by inflammatory reactions and that endotoxins and cytokines are involved in qualitative, but not quantitative changes in LFA-1 (CD11a/CD18) and Mac-1 (CD11b/CD18).

Adult↗

PubMed1996

[The study of the relationship between serum eosinophil cationic protein and bronchial responsiveness in the patients with bronchial asthma].

Eosinophil cationic protein (ECP) has been expected as an index of eosinophilic inflammation in bronchial asthma. However, there are many questions about the clinical meaning of the serum ECP, yet. To examine that problem, we measured serum ECP levels in healthy subjects and the asthmatics patients, with and without attack. We also studied the relationship between bronchial responsiveness and serum ECP levels in the asthmatics patients without attack. Patients taking any steroids (including inhaled steroid), anti-allergic agents or cigarettes were excluded. The highest levels of ECP were found in serum sampled from the patients with asthma attack. The levels of the patients without attack were lower, and the levels of the healthy subjects were the lowest of all. To study the relationship between serum ECP and bronchial responsiveness in the asthmatics patients, who had not an asthma attack for at least one week, serum was sampled and simultaneously bronchial responsiveness (Dmin) was measured by Astograph. The serum ECP levels correlated negatively with Dmin, a threshold-type index of bronchial responsiveness (r = -0.569, p < 0.01). These data indicate that between attacks of bronchial asthma, bronchial responsiveness is related to the levels of serum ECP, and that during attacks the level of serum ECP increases further. They also suggest that abnormally high levels of serum ECP are associated with a preattack state in patients with bronchial asthma.

Adolescent↗

PubMed1996

Plasma levels of interleukin-1 receptor antagonist (IL-1ra) and severity of illness in patients with burns.

The present study was conducted to determine whether a plasma interleukin-1 receptor antagonist (IL-1ra) would reflect the severity of burn injury and to examine the relation between IL-1ra and the cytokines. We studied 24 burn patients in whom the total burn surface area (TBSA) accounted for at least 20% of the body surface, and in whom serial blood samples could be obtained beginning immediately after the burn injury. Plasma levels of IL-1ra were determined by enzyme-linked immunosorbent assay (ELISA). Plasma levels of tumor necrosis factor-alpha (TNF-alpha), IL-6, and IL-8 were also determined by ELISA. Endotoxin was measured by an endotoxin-specific synthetic substrate method. There was a significant correlation between the plasma levels of IL-1ra and TBSA during the first week following burn injury. The IL-1ra level was the highest immediately after the burn injury. The level decreased markedly thereafter, and again rose when infection occurred. The IL-1ra level was extraordinarily elevated in patients who developed concomitant sepsis, septic shock or the septic multiple organ dysfunction syndrome. The IL-1ra level on admission and the maximum IL-1ra level during the observation period were significantly higher in the patients who eventually died than in the survivors. There was a significant correlation between the level of IL-1ra and that of TNF-alpha, IL-6 or IL-8 during the observation period. No correlation was found between IL-1ra and endotoxin. The plasma IL-1ra level was closely correlated with the severity of inflammation and the clinical status of the burn patients, regardless of the infection. Results suggest that IL-1ra can serve as an index of the systemic inflammatory response syndrome (SIRS).

Adult↗

PubMed1996

Lack of response to dietary protein in pancreatic secretion by chronic deprivation of jejunal chyme in rats.

BACKGROUND: Exocrine pancreatic secretion is regulated by luminal factors, bile-pancreatic juice (BPJ), and food chyme. The effects of 10 days' chronic deprivation of luminal chyme on the stimulation of exocrine pancreatic secretion by dietary protein were examined in rats with or without BPJ in the jejunum. METHODS: The jejunum was deprived of ingested food by preparing a whole-jejunum blind loop. The BPJ was diverted by a common bile-pancreatic duct catheter and was returned to the upper jejunum (with BPJ) or ileum (without BPJ). RESULTS AND CONCLUSION: In rats with the ingested food and BPJ in the jejunum (control), secretion rates in terms of volume, protein, amylase, and trypsin increased more than twofold from the rates in the fasting state after a jejunal injection of peptic hydrolysate of casein. In contrast, the secretions were not increased by the protein injection in the rats deprived of jejunal chyme with or without BPJ in the jejunum. Even in the chyme-deprived group the protein and trypsin secretion of the fasting state was significantly higher in BPJ-diverted rats than in rats with BPJ. These results showed that chronic deprivation of the jejunal chyme impaired responses of the exocrine pancreas to dietary protein but not the hypersecretions of the pancreas by BPJ diversion.

Amylases↗

PubMed1996

Functional modification of vascular endothelial cells by cytokines during septic shock.

The function of vascular endothelial cells is to adjust blood vessel tonus, which contributes to maintaining homeostasis within blood vessels. However, inflammatory cytokines are produced in response to invasion by stimulating vascular endothelial cells and sometimes lead to shock or multiple organ failure. In the present study, we assessed cytokines in sepsis and septic shock, and various factors that are said to have a damaging effect on vascular endothelium. Endotoxin was measured by endotoxin-specific methods. Tumor necrosis factor-alpha (TNF-alpha), interleukin 6 (IL-6), and interleukin 8 (IL-8) were measured by enzyme-linked immunosorbent assay (ELISA). Endothelin-I was measured by radioimmunoassay (RIA). Nitric oxide was measured as metabolites of nitrite and nitrate oxides (NOx) by a method based on the Griess method. Thromboxane B2 (TXB2) and 6-keto-prostaglandin F1 alpha (PGF 1 alpha) were both measured by RIA. All of the factors except endotoxin were significantly higher in the septic shock group than in the non-shock group and significantly higher in the non-survivor group than in the survivor group. Significant correlations were also found between endothelin-1 and NOx and between TXB2 and PG1 alpha. Significant correlations were also found between TNF-alpha and IL-6, endothelin-1, NOx and TXB2, but no significant correlations were detected between any of them and endotoxin. In serious diseases such as septic shock, the vascular endothelial constricting factors, endothelin and TXB2, and the blood vessel relaxing factors NOx and PGF1 alpha increase almost simultaneously. This suggests that the body's regulating mechanisms are disrupted in these serious conditions. The results of this study also suggest that inflammatory cytokines may be involved in stimulating the production of these factors.

Adult↗

PubMed1995

Evidence for soleus H-reflex depression induced by ballistic head rotation.

In this study, we described a sequence of changes of the electromyographic (EMG) and depression of the soleus (Sol) H-reflex that precede and follow the onset of ballistic head rotation in freely standing human subjects. During head rotation, a sequence of EMG changes occurred simultaneously in Sol and in biceps femoris muscle (BF). Specifically, changes to Sol EMG included deactivations (EMG silent period) and H-reflex depression coincident with BF excitation. Thus, in the case of ballistic head movement, control commands for anticipatory postural adjustment appear to excite BF and inhibit Sol in a similar way to that previously described for the onset of arm movement.

Adult↗

PubMed1995

Heat-inducible expression system for a foreign gene in cultured tobacco cells using the HSP18.2 promoter of Arabidopsis thaliana.

A system for the controlled expression of a foreign gene in cultured tobacco cells (Nicotiana tabacum, BY2) by temperature shift was constructed. A 925-base-pair (bp) DNA fragment containing the 5'-flanking region of a low-molecular-mass heat-shock protein gene (HSP18.2) of Arabidopsis thaliana was inserted upstream of the beta-glucuronidase reporter gene (GUS). The resulting HSP18.2-GUS construct was introduced into BY2 cells by electroporation or Agrobacterium-mediated transformation. Transient expression of the HSP18.2 promoter in protoplasts was very low regardless of the heat shock. Although expression of the HSP18.2-GUS chimeric gene in the stable transformants of BY2 was hardly detected in culture at 25 degrees C, the expression increased rapidly on the transcriptional level when the incubation temperature was shifted to 35-37 degrees C. The optimal temperature for heat-shock induction was 37 degrees C. After a 2-h incubation at 37 degrees C, GUS activity was about 1000-fold greater than that before heat shock. The amount of GUS mRNA was maximum 2 h after heat shock, and then decreased gradually.

Agrobacterium tumefaciens↗

PubMed1995

Splenic metastasis from lung cancer.

Splenic metastasis from lung cancer is a rare clinical event, most often diagnosed at the time of autopsy. We report 2 cases of splenic metastasis with a primary lung cancer. The first case was a 76-year-old man presenting with a recurrent solitary splenic metastasis 14 months after surgical removal of a squamous cell carcinoma of the lung. The second patient was a 72-year-old woman who had a poorly differentiated carcinoma of the lung and multiple abdominal metastasis. We also investigated 267 autopsy cases of lung cancer from 1975 to 1992. Histologically, there were 73 cases of squamous cell carcinoma, 123 adenocarcinoma, 29 large cell carcinoma, 36 small cell carcinoma, and 7 other miscellaneous tumours. The number of splenic metastasis from lung cancer in these cases was 15 (5.6%). Splenic metastasis from a primary cancer of the left lung was more frequent than that from the right lung. Nine of 15 splenic metastases were smaller than 1 cm in size. Splenic metastasis was associated with liver and pancreas metastasis. All 15 autopsy cases with splenic metastasis from lung cancer had other abdominal organ metastasis. Our analysis indicates that a solitary splenic metastasis is rare. Selection of a suitable therapeutic approach is important.

Aged↗

PubMed1995

Plasma concentrations of type II phospholipase A2, cytokines and eicosanoids in patients with burns.

The plasma concentrations of type II phospholipase A2 (type II PLA2) and eicosanoids, such as leukotriene B4 (LTB4), 6-keto-prostaglandin F1 alpha (6-keto-PGF1 alpha), and thromboxane B2 (TXB2), were determined by radioimmunoassay in 23 patients with burns covering at least 20 per cent of their body surface. Cytokines such as tumour necrosis factor-alpha (TNF-alpha), interleukin 6 (IL-6) and interleukin 8 (IL-8) were determined by enzyme-immunosorbent assay. There was no increase in type II PLA2 concentration in the early stage of burns, but an increase in type II PLA2 concentration was triggered by infection (P < 0.0001). The level of type II PLA2 was significantly higher in the non-surviving group than in the surviving group (P = 0.0006), suggesting that it reflects the severity of the disease. There was a significant correlation between the maximum level of type II PLA2 and TNF-alpha (r = 0.6346, P = 0.0011). There was a significant correlation between the maximum level of type II PLA2 and the accompanying plasma concentrations of LTB4, 6-keto-PGF1 alpha, and TXB2 throughout the observation period (r = 0.4814, P = 0.0200; r = 0.5943, P = 0.0028; r = 0.4368, P = 0.0372 respectively). Plasma levels of LTB4, and TXB2 were significantly higher in the burn patients who died than in those who survived (P = 0.0493; P = 0.0493 respectively).

Adult↗

PubMed1995

Induction of pancreatic growth and proteases by feeding a high amino acid diet does not depend on cholecystokinin in rats.

We examined differences in pancreatic growth, enzyme content and enzyme concentration between rats fed diets containing normal (2.49 g nitrogen/kg diet) or high (7.46 g nitrogen/kg diet) levels of an amino acid mixture and those in rats fed diets containing normal and high levels of casein for 11 d. Rats fed these diets were injected with a potent cholecystokinin antagonist, MK-329 (2.5 mg/kg body wt.d) or with vehicle only. Pancreatic contents (units in pancreas per 100 g body wt) of protein, trypsinogen and chymotrypsinogen were greater in rats fed a high amino acid diet compared with those in rats fed a normal amino acid diet. Proportionate increases in protein and the serine proteases in pancreata of the high amino acid group relative to those of the normal amino acid group were comparable to those of the high casein group relative to the normal casein group. The pancreatic protease concentrations (units/g pancreas) of rats fed the high casein diet and treated with MK-329 were lower than in rats fed high casein but not treated with MK-329. This difference was not observed in rats fed the high amino acid diet. These results demonstrate that pancreatic growth and proteases are induced by dietary amino acids in rats, and the stimulatory effects of amino acids on exocrine pancreas do not depend on cholecystokinin.

Amino Acids↗