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Biomedical subjects

J Maeda

Publications and source records attributed to J Maeda.

At least 37 records · Page 2Linked to original sources
PubMed1998

Direct transfer of bovine embryos frozen-thawed in the presence of propylene glycol or ethylene glycol under on-farm conditions in an integrated embryo transfer program.

An integrated bovine embryo transfer program was conducted in collaboration with 11 Japanese prefectural livestock experiment stations. The program was conducted to evaluate the practicability of the direct transfer method for bovine embryos frozen-thawed in the presence of propylene glycol (PG) or ethylene glycol (EG) under on-farm conditions. Embryos at the compacted morula to expanded blastocyst stages were collected from superovulated donors on Day 7 or 8 after estrus and equilibrated in 1.6 M PG or 1.8 M EG in Dulbecco's phosphate-buffered saline (DPBS) supplemented with 20% heat-inactivated calf serum. Embryos were then loaded individually into a 0.25-ml straw and placed directly into a cooling chamber of a programmable freezer precooled to -7 degrees C. After 2 min, the straw was seeded, maintained at -7 degrees C for 8 min more, and then cooled to -30 degrees C either at 0.3 degree C/min or 0.5 degree C/min before being plunged into liquid nitrogen. Embryos at the same stages were also frozen in the presence of 1.4 M glycerol (GLY) by a conventional method, which served as a control. The frozen embryos were thawed by allowing the straws to stand in air for 5 to 10 sec and then immersing them in a 30 degrees C water bath. Embryos frozen-thawed in the presence of PG or EG were nonsurgically transferred into the uterine horn without diluting the cryoprotectant. Embryos frozen-thawed in the presence of GLY were nonsurgically transferred after removing GLY either by the stepwise method (GLY-I) or by in situ dilution with 0.3 M sucrose solution (GLY-II). A total of 1,273 (PG: 400, EG: 418, GLY-I: 177, GLY-II; 278) frozen-thawed embryos was transferred into recipients, yielding 545 pregnancies (overall: 42.8%, PG: 36.0%, EG; 44.7%, GLY-I; 48.6%, GLY-II; 46.0%). The pregnancy rate with PG was significantly lower than that with EG or GLY-II (P < 0.05). The pregnancy rate was affected by the type of cryoprotectant, the region where the embryo transfer program was carried out, the developmental stage of the embryos, the parity of the recipients, and corpus luteum (CL) quality of the recipients. There were no differences in rates of abortion and stillbirth among the 3 cryoprotectants. The present study demonstrates that EG can be effectively used as a cryoprotectant for freezing and direct transfer of bovine embryos, and that the direct transfer method is applicable under on-farm conditions.

Animals↗
PubMed1998

Endurance exercise training increases peripheral vascular response in human fingers.

The purpose of this study was to clarify whether peripheral vascular response to alteration of transmural pressure is changed by endurance exercise training. The healthy male subjects (training group; n = 6) performed endurance exercise training that consisted of cycle ergometer exercise 5 d.week-1 and 30 min.d-1 for a period of 8 weeks. Changes in the peripheral vascular response to alteration of transmural pressure in the human finger were measured by a differential digital photoplethysmogram (DeltaDPG) and blood pressure during passive movement of the arm to different vertical hand positions relative to heart level. Following 8 weeks of endurance training, percent changes in DeltaDPG from heart level in the training group increased significantly (mean +/- SD, -48.1 +/- 7. 3 to -58.7 +/- 9.3% at the lowered position, 46.1 +/- 13.4 to 84.6 +/- 8.8% at the elevated position, p<0.05). Similarly, the arterial compliance index, which was calculated from DeltaDPG-P wave amplitude and arterial pulse pressure, also significantly changed in the training group over the 8 weeks (5.6 +/- 1.3 to 2.7 +/- 1.6 mV. V-1.s-1.mmHg-1 at the lowered position, 30.0 +/- 12.4 to 54.4 +/- 18. 9 mV.V-1.s-1.mmHg-1 at the elevated position ). Maximal oxygen uptake (V.O2 max) was significantly increased in the training group. On the other hand, the control group (n = 6) showed no significant changes in all parameters for 8 weeks. Therefore these results suggest that endurance exercise training induces an increase in peripheral vascular response to alteration of transmural pressure in the human finger.

Adult↗
PubMed1997

Differential effects of mu-, delta- and kappa-opioid receptor agonists on the discriminative stimulus properties of cocaine in rats.

The effects of selective mu-, delta- and kappa-opioid receptor agonists on the discriminative stimulus properties of cocaine were examined in rats trained to discriminate between cocaine (10 mg/kg) and saline. Cocaine produced a dose-related increase in cocaine-appropriate responses in all of the rats. In generalization tests, neither morphine (mu-opioid receptor agonist) nor N-methyl-N-7-(1-pyrrolidinyl)-1-oxaspiro[4,5]dec-8-11-4-benzofu ranacetamide (U50,488H: kappa-opioid receptor agonist) generalized to the discriminative stimulus properties of cocaine. On the other hand, the newly synthesized non-peptide selective delta-opioid receptor agonist 2-methyl-4a alpha-(3-hydroxyphenyl)-1,2,3,4,4a,5,12,12a alpha-octahydro-quinolino(2,3,3,-g)isoquinoline (TAN-67) partially generalized (56.7% cocaine-appropriate responses) to the discriminative stimulus properties of cocaine. Intracerebroventricular (i.c.v.) administration of [D-Ala2]deltorphin II (peptide delta 2-opioid receptor agonist) completely generalized, while neither [D-Ala2,MePhe4,Gly-ol5]enkephalin (DAMGO: mu-opioid receptor agonist) nor [D-Pen2,D-Pen5]enkephalin (DPDPE; delta 1-opioid receptor agonist) generalized to the discriminative stimulus properties of cocaine. These results suggest that the discriminative stimulus properties of cocaine may be partially mediated by delta-opioid (especially delta 2-opioid) receptors. In combination tests, pretreatment with morphine (3.0 mg/kg) and TAN-67 (3.0 and 10 mg/kg) significantly potentiated the discriminative stimulus properties cocaine. In contrast, pretreatment with U50,488H (2.0 and 4.0 mg/kg) scarcely shifted the discriminative stimulus properties of cocaine. Furthermore, the potentiating effect of 3.0 mg/kg morphine on the discriminative stimulus properties of cocaine was attenuated by 2.0 mg/kg U50,488H. In contrast, the potentiating effect of 10 mg/kg TAN-67 on the discriminative stimulus properties of cocaine was not reversed by either 2.0 or 4.0 mg/kg U50,488H. These results suggest that mu-, delta- and kappa-opioid receptor agonists modulate the discriminative stimulus properties of cocaine through different mechanisms, perhaps through different effects on the dopaminergic system.

3,4-Dichloro-N-methyl-N-(2-(1-pyrrolidinyl)-cycloh↗
PubMed1997

Mesoderm induction by BMP-4 and -7 heterodimers.

Bone morphogenetic proteins (BMPs) are peptide growth factors belonging to the TGF-beta superfamily. A large number of these ligands, including BMP-2, -4 and -7 is expressed during early embryogenesis in the vertebrate embryo. In this study, we demonstrate that BMP-7 has ventralizing activity both in ectodermal explants as well as in whole embryos. As it was the case for BMP-2 and BMP-4, BMP-7 is a very poor inducer when provided as a homodimer protein. Because of this weak mesoderm inducing activity, it has been suggested that mesoderm induction by BMPs might represent an artifact of overexpression. We provide evidence demonstrating that unlike the homodimers of BMP-4 or BMP-7, the purified recombinant heterodimer of Xenopus BMP-4 and BMP-7 (BMP-4/7) has a potent mesoderm inducing activity at physiological concentrations. These results provide the first evidence for an embryonic function of BMP-4/7 heterodimers in the vertebrate embryo.

Animals↗
PubMed1997

Effect of glutamine on acute lung injury in rats with endotoxemia.

We administered endotoxin to rats to produce an acute lung injury model, and assessed the effect on respiratory function when glutamine was added to the solution for total parenteral nutrition. Rats given total parenteral nutrition with glutamine as 33% of the amino acid content were compared with rats given no glutamine. Endotoxin (500 microg/kg) was administered intravenously after 72 h of total parenteral nutrition. The survival rate and the nitrogen balance were significantly improved (P < 0.05) at 48 h after endotoxin administration as a result of glutamine treatment. In addition, the arterial oxygen partial pressure was significantly increased (P < 0.01) and the wet: dry lung weight ratio was decreased (P < 0.05) by glutamine. These results suggested that glutamine improved endotoxin-induced acute lung injury in rats.

Journal Article↗
PubMed1997

Efficacy of amino acid infusion for improving protein metabolism after surgery: a prospective randomized study in patients undergoing subtotal gastrectomy.

BACKGROUND: Appropriate regimens of peripheral parenteral nutrition (PPN) have been proposed for the improvement of protein metabolism after surgery. When evaluating the efficacy of administered nutrients, it is vital to consider the severity of surgical stresses to avoid confounding effects of the trauma on the postoperative metabolism. This study was designed to evaluate protein-sparing regimens through PPN in patients who had undergone subtotal gastrectomy. STUDY DESIGN: Patients hospitalized at our institutes for gastric cancer were randomly divided into the following five groups and received PPN for 7 days after surgery: 1. G group (n = 9), 200 g glucose (per day); 2. AG group (n = 10), 54 g amino acids + 150 g glucose; 3. AGG group (n = 9), AG + 110 g glucose; 4. AGF group (n = 10), AG + 40 g fat; and 5. AGL group (n = 7), 58 g amino acids + 60 g glycerol. Biochemical studies were done before and after surgery. RESULTS: In comparison to G group patients, AG group patients showed less negative cumulative nitrogen balances. No significant differences in cumulative nitrogen balances were observed between AGG, AGF, and AGL groups. Restoration of the reduced serum rapid turnover protein occurred earlier in the AGL group than in either the AGG or the AGF groups. Hyperglycemia, glucosuria, and hyperinsulinemia were prominent in the AGG group, and less prominent in the AGL group. Marked ketosis together with an increase in serum-free fatty acid levels was found in the AGL group. CONCLUSIONS: These results suggest that in patients who have undergone major elective surgery, infusion of amino acid solutions is advantageous for improving protein metabolism after surgery, and nonprotein energy source and intake are not essential when combined with amino acid solutions for improving nitrogen balance after surgery.

Adult↗
PubMed1996

Mecamylamine-precipitated nicotine-withdrawal aversion in rats.

The present study examined a rapid and convenient model for evaluating nicotine dependence using the conditioned place preference paradigm. Rats were chronically infused subcutaneously with 9 mg/kg per day nicotine using an osmotic minipump. After nicotine infusion for 7 days, the nicotinic receptor antagonist mecamylamine produced a place aversion in nicotine-dependent rats, but not in acute nicotine-treated rats or sham-operated rats. These results suggest that the mecamylamine-precipitated withdrawal aversion in rats chronically treated with nicotine may result from physical dependence on nicotine, and may be useful for studying the physical dependence on nicotine.

Analysis of Variance↗
PubMed1996

Leiomyoma of the lesser omentum: report of a case.

The case of a 67-year-old Japanese woman with leiomyoma arising from the lesser omentum is reported herein. Although the patient had no abdominal symptoms, findings of a routine abdominal ultrasound examination suggested a mass between the stomach and the lateral segment of the liver. Subsequent magnetic resonance imaging (MRI) demonstrated a 6-cm well-encapsulated tumor in the lesser omentum, and this was confirmed intraoperatively. Resection of the tumor was performed without any other procedure and the histological diagnosis was confirmed as leiomyoma. The patient has been well for the 6 months since her operation. To our knowledge, this is the first report in the English literature of leiomyoma arising from the lesser omentum.

Aged↗
PubMed1996

Effects of immunoglobulin and gamma-interferon on the production of tumour necrosis factor-alpha and interleukin-1 beta by peripheral blood monocytes in the acute phase of Kawasaki disease.

In order to study the in vitro effects of intact immunoglobulin (Ig) and gamma-interferon (INF-gamma) in patients with Kawasaki disease, the production of tumour necrosis factor-alpha (TNF-alpha) and interleukin-1 beta (IL-1 beta) was measured in peripheral blood monocytes (PBM) both before and after intravenous immunoglobulin (IVIG) therapy. Spontaneous production of TNF-alpha and IL-1 beta both before and after IVIG therapy was significantly higher than in healthy controls. Intact Ig enhanced in vitro the production of TNF-alpha and IL-1 beta both before and after IVIG therapy approximately 3-4 times as compared to the spontaneous production. INF-gamma did not affect the production of the two cytokines. Ig enhanced IL-1 beta mRNA expression in PBM of KD by 3-8 times more than that of spontaneous production.

Acute Disease↗
PubMed1996

Floating gallbladder associated with histologically distinct double cancers.

A case of unusually hypermobile floating gallbladder in a 79-year-old woman with histologically distinct double cancers of the gallbladder is described. The patient presented with an abdominal cystic mass, which was palpable with easy mobility from the right lower quadrant practically to the left upper quadrant. Exploratory laparotomy was performed and the cystic mass was found to be a floating gallbladder. The cystic duct was elongated and obstructed, and had a long mesentery. After the operation, latent double cancers of the gallbladder were discovered on histopathological examination. The obstruction of the cystic duct was due to chronic inflammation and had resulted in hydrops of the gallbladder. This was suspected to have played an important role in the carcinogenesis. We believe that this is the first report of a floating gallbladder associated with double gallbladder cancers.

Adenocarcinoma↗
PubMed1996

Distribution of endogenous and exogenous carnitine in rats with sepsis and acute liver failure.

The distribution of carnitine was investigated in male Wistar rats with sepsis or acute liver failure. Sepsis was produced by cecal ligation and puncture, while acute liver failure was induced by intraperitoneal injection of carbon tetrachloride. Then 14C-carnitine or L-carnitine was injected intravenously. In healthy control rats and rats with sepsis, both 14C-radioactivity and carnitine were increased in the liver and kidneys. When the carnitine fractions were investigated, it was found that free carnitine and short-chain acylcarnitine were increased. In the rats with acute liver failure, 14C-radioactivity decreased in the liver, but carnitine increased, with free carnitine and short-chain acylcarnitine levels rising. These findings suggested that exogenous free carnitine accumulated directly in the organs with carnitine deficiency in rats with sepsis and acute liver failure. In addition, there was differential regulation of the fractions of both exogenous and endogenous carnitine (free carnitine, short-chain acylcarnitine, and long-chain acylcarnitine). Furthermore, the distribution of exogenous carnitine differed between sepsis and acute liver failure.

Journal Article↗
PubMed1996

In vitro development of bovine embryos in conditioned media from bovine granulosa cells and vero cells cultured in exogenous protein- and amino acid-free chemically defined human tubal fluid medium.

We have investigated the effect of protein- and amino acid-free simple human tubal fluid (HTF) medium conditioned with bovine granulosa cells (BGC) or Vero cells on the development of early bovine embryos to the blastocyst stage. Serum-containing medium (SCM) and serum-free medium (CM) conditioned by BGC (BGC-SCM, BGC-CM) and by Vero cells (VC-SCM, VC-CM) were prepared. Early embryos (1-cell stage and 5- to 8-cell stage) were obtained by in vitro maturation and fertilization of oocytes from slaughtered cows. Embryos were randomly divided into 7 culture groups as follows: culture with BGC-SCM, BGC-CM, VC-SCM, or VC-CM; coculture with BGC or Vero cells; or culture with fresh HTF medium without serum. The proportion of 5- to 8-cell embryos developing to the blastocyst stage in BGC-CM (16%) and VC-CM (12%) was significantly lower (p < 0.05) than in BGC-SCM (41%) and in VC-SCM (29%) and after coculture with BGC (48%) and Vero cells (30%). Similarly, the percentages of 1-cell embryos developing to blastocyst in BGC-CM and VC-CM were significantly lower than in BGC-SCM and VC-SCM and after coculture. Cell numbers per blastocyst developed from 5- to 8-cell embryos in BGC-CM (96.8 cells) and in VC-CM (94.0 cells) were somewhat lower than those in BGC-SCM (128.5 cells) and VC-SCM (117.1 cells) and after coculture with BGC (124.2 cells) and Vero cells (115.3 cells). These results suggest that BGC and Vero cells cultured in a protein- and amino acid-free simple HTF medium synthesize and secrete factor(s) promoting blastocyst formation in vitro. Physiochemical analysis indicated that the embryotrophic substances in BGC-CM were distributed in two molecular size ranges, one between 10 kDa and 30 kDa and another greater than 30 kDa.

Amino Acids↗
PubMed1996

Spontaneous perforated pyometra presenting as pneumoperitoneum.

BACKGROUND: Spontaneous perforated pyometra presenting as pneumoperitoneum is extremely rare. CASE REPORT: An 80-year-old Japanese female with spontaneous perforating pyometra presenting as pneumoperitoneum is reported. The patient came to our institute with severe abdominal pain. Routine abdominal examination showed muscular defense, and plain chest roentgenograms revealed infradiaphragmatic free gas. Subsequent computed tomography also demonstrated pneumoperitoneum. Laparotomy was performed on the basis of a tentative diagnosis of perforation of the gastrointestinal tract but revealed a perforated pyometra. A simple hysterectomy was performed. The histological diagnosis of the surgical specimen was acute endometritis without neoplasm. The present report is the third case of spontaneous perforated pyometra with pneumoperitoneum to date. CONCLUSION: Although uterine disease presenting as pneumoperitoneum is rare in elderly patients with an acute abdomen, the possibility of a perforated pyometra should be considered in the differential diagnosis.

Aged↗
PubMed1995

The D3-receptor agonist (+/-)-7-hydroxy-N,N-di-n-propyl-2-aminotetralin (7-OH-DPAT) attenuates morphine-induced hyperlocomotion in mice.

The effects of the D3-agonist (+/-)-7-hydroxy-N,N-di-n-propyl-2-aminotetralin (7-OH-DPAT) on morphine-induced hyperlocomotion were investigated in mice. 7-OH-DPAT (0.01-0.3 mg/kg s.c.) alone did not produce a significant locomotor activity in mice. Treatment with low doses of 7-OH-DPAT (0.1 and 0.3 mg/kg s.c.) attenuated morphine (10 and 20 mg/kg s.c.)-induced hyperlocomotion. The significant morphine-induced increase in dopamine (DA) metabolite levels, 3,4-dihydroxyphenylacetic acid and homovanillic acid in the limbic forebrain (nucleus accumbens and olfactory tubercle) was suppressed by 7-OH-DPAT. These results suggest that activation of the D3-receptor in the mesolimbic dopamine system may attenuate the expression of morphine-induced hyperlocomotion.

Animals↗
PubMed1995

Elevated serum hepatocyte growth factor/scatter factor levels in inflammatory lung disease.

Hepatocyte growth factor/scatter factor (HGF/SF) plays an important role in tissue repair in liver and renal damage. The clinical significance of this growth factor in these diseases has also been reported. The lung is one of the major sources of HGF/SF; because of this, we investigated serum HGF/SF levels in 26 patients with inflammatory lung disease (15 with interstitial pneumonitis [IP], 11 with bacterial pneumonia [BP]) by enzyme-linked immunosorbent assay. As controls, we measured HGF/SF in the serum of 13 stable outpatients with chronic respiratory failure. All patients had no significant liver or renal dysfunction. Serum HGF/SF levels were significantly elevated in patients with IP (1.16 +/- 0.22 ng/ml) or BP (0.96 +/- 0.27 ng/ml) compared with those in the control subjects (0.29 +/- 0.03 ng/ml, both p < 0.01). Serum HGF/SF levels in 14 healthy subjects were also studied, and the results (0.30 +/- 0.02 ng/ml) were not remarkably different from those of the control subjects. There were no significant correlations between serum HGF/SF levels and C-reactive protein and lactate dehydrogenase. Serum HGF/SF levels in the surviving patients rapidly decreased with treatment, but they did not change in the patients who ultimately died. Our results demonstrate the clinical significance of serum HGF/SF level as a useful indicator of prognosis in inflammatory lung disease.

Adolescent↗
PubMed1995

Beneficial effects of enteral fat administration on liver dysfunction, liver lipid accumulation, and protein metabolism in septic rats.

The purpose of this study was to examine the effect of different amounts of fat in enteral diets on liver function, liver lipid accumulation, and protein metabolism in septic rats. Sepsis was induced in Wistar rats by cecal ligation and puncture. The rats were divided into four groups and were fed enterally 0% (FO, n = 7), 10% (F10, n = 7), 20% (F20, n = 8), or 30% (F30, n = 9) of total calories as fat. The liquid diet consisted of medium-chain and long-chain triglyceride mixtures as the fat sources, casein oligopeptide, and dextrin (100 kcal/100 ml). Intraduodenum feeding was ended on the 6th day. Serum glutamic oxaloacetic transaminase and glutamic pyruvic transaminase activities, indices of liver dysfunction, were highest in the FO group, and triglycerides accumulated in the livers of that group, possibly because of the large proportion of carbohydrate in the diet. Value of nitrogen balance was highest in the F 10 group, and serum total protein and albumin concentration were higher in the F10 and F20 groups than in the FO and F30 groups. The liver protein content in the F10 and F20 groups was higher than in the FO and F30 groups. Serum triglyceride in the F30 group was about 2 times higher than in the F10 and F20 groups. These results indicate that enteral fat administration in septic rats as 30% of total calories reduced liver dysfunction and liver triglyceride accumulation, but might have been excessive for optimal protein metabolism. Therefore, the preferable amount may range from 10% to 20% of total calories.

Alanine Transaminase↗
PubMed1994

Increased capillary density due to atrophy of ischaemic soleus muscle of the rat.

This investigation was undertaken to determine whether a severe limitation of blood supply by external iliac artery ligation can change the number and density of capillaries in rat soleus muscle. The external iliac artery in one hindlimb was ligated for 2, 7 or 28 days, and the other, sham-operated, hindlimb was used as a control. Muscle blood flow in the ischaemic soleus muscle at 2, 7 and 28 days after external iliac artery ligation was significantly decreased compared with the control. The muscle fibre area and the ratio of the fibre area to body mass in the ischaemic soleus muscle at 28 days after the external iliac artery ligation were significantly reduced in the ischaemic soleus muscle, but no change in the number of capillaries per fibre was observed. Capillary density per millimetres squared at 28 days and the ratios of the number of capillaries around type I fibres to the fibre area at 7 and 28 days were significantly increased in the ischaemic soleus muscle (P < 0.05). These results suggested that long-term severe limitation of blood flow in the soleus muscle by ligation of the external iliac artery could have induced the increase in capillary density, as a result of atrophy of muscle fibres rather than capillary growth.

Animals↗