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Biomedical subjects

K Imamura

Publications and source records attributed to K Imamura.

At least 127 records · Page 7Linked to original sources
PubMed1995

Compound heterozygous mutations affecting both hepatic and erythrocyte isozymes of pyruvate kinase.

Novel erythrocyte pyruvate kinase gene defects were found in a patient without a family history of consanguinity. The polymerase chain reaction products of the R-type pyruvate kinase cDNA from the propositus contained two point mutations of Ser80 (TCC)-->Pro (CCC) and Arg490 (CGG)-->Trp (TGG). Allele-specific polymerase chain reaction of the genomic DNA revealed that this patient was a compound heterozygote. The mobilities of the patient's L- and R-type pyruvate kinase by thin-layer polyacrylamide gel electrophoresis were abnormal. The results are consistent with the fact that these mutations are within exons common to the hepatic and erythrocyte isozymes.

Adult↗
PubMed1995

Incomplete development of the spleen and the deformity in the chimeras between asplenic mutant (Dominant hemimelia) and normal mice.

The semidominant gene Dh (Dominant hemimelia) induces skeletal and visceral abnormalities of various degrees and failure of the spleen in mice. The homozygous individual (Dh/Dh) seems to be lethal. The present experiment was designed to investigate the ability Dh cells to form a spleen and the genesis of the hind limb malformations by Dh/Dh and Dh/+ cells in chimeric mice. The Dh/Dh and Dh/+ embryos were produced in the F2 progeny of a cross between inbred strains of Dh/+ and DDD mice. They were aggregated with C3H/He or C57BL/6 embryos to make chimeras. Identification of Dh/Dh or Dh/+ embryos was carried out by Pep-3, and chimerism was analyzed by Gpi-1. Of 25 chimeras carrying the Dh gene, four mice formed a small spleen, two mice had a vestigial spleen, and the others no spleen. The tissues of the incompletely developed spleens were normal histologically and Dh cells were involved in the tissues of the spleen. In the chimeric mice, hindlimb malformation by the Dh gene was reduced in severity and the lethality of the homozygote (Dh/Dh) was rescued.

Animals↗
PubMed1995

Functional liver imaging with asialoglycoprotein receptors and serum hyaluronate in a patient with amyloidosis.

A 47-year-old man with primary amyloidosis was admitted with abdominal pain. A new radionuclide liver imaging technique using Technetium-99m diethylenetriamine-pentaacetic acid-galactosyl human serum albumin, was performed and the serum hyaluronate concentration was measured. Although ordinary laboratory tests revealed only slight abnormalities, the uptake of the radiolabelled ligand for hepatocyte asialo-glycoprotein receptors was decreased, and marked hepatomegaly was revealed. Furthermore, the serum hyaluronate level was elevated. Histological examination of a hepatic needle biopsy specimen revealed a marked deposition of amyloid in the hepatic perisinusoidal spaces. These results indicate that this new radionuclide liver imaging technique (using Technetium-99m diethylenetriamine-pentaacetic acid-galactosyl human serum albumin) and the measurement of serum hyaluronate may be useful supplementary tools for identifying amyloid deposition in the hepatic perisinusoidal spaces in patients with amyloidosis.

Amyloidosis↗
PubMed1995

No negative feedback regulation between plasma CCK levels and luminal tryptic activities in patients with pancreatic insufficiency.

The study was conducted on five healthy subjects and six patients with calcifying pancreatitis (CP) and steatorrhea. Following overnight fasting, one tube each was placed in the stomach and the upper of the small intestine, respectively. Through the gastric tube, a test meal that included 30 g of fat (total calories, 625 kcal, 500 mL) was infused over a span of 30 min. Every 30 min (up to 150 min), fluid samples in the upper small intestine were collected and chilled, and the amylase, trypsin, and lipase levels were determined. In addition, in the case of the CP patients, a high-potency pancreatin preparation was infused into the stomach together with the test meal. In order to determine the plasma CCK level, blood sample were collected before test meal infusion and at 10, 20, 30, 45, 60, 90, 120, and 150 min subsequent to infusion. The plasma CCK was extracted using a Sep-Pak C-18 cartridge and analyzed with radioimmunoassay using an OAL-656 antibody. The result was converted to the CCK-8 level and expressed in pg/mL. The enzyme activities in the upper small intestine of the CP patients after test meal administration amounted to 22.8 (amylase), 10.8 (trypsin), and 16.9% (lipase) compared with the corresponding figures for the normal subjects. Following administration of a high-potency pancreatin in patients with CP, enzyme activities in the upper small intestine increased to 132.2 (amylase), 38.7 (trypsin), and 45.3% (lipase) compared with levels in the normal subjects. However, the healthy subjects and the CP patients, both with and without treatment with supplementary exogenous enzymes, all exhibited similar profiles in the plasma CCK response to stimuli. Based on these findings, we concluded that a negative feedback mechanism does not exist between the tryptic activity of the upper small intestine and the CCK secretory response in patients with chronic pancreatitis.

Adult↗
PubMed1995

Changes in carnitine metabolism with ketone body production in obese glucose-intolerant patients.

To elucidate the relationship between carnitine metabolism and plasma ketone body concentrations in moderately obese patients with mild glucose intolerance, the ketone body and carnitine levels in the basal state were determined in 72 obese patients: 20 with normal glucose tolerance (NGT), 29 with impaired glucose tolerance (IGT), and 23 with non-insulin-dependent diabetes mellitus (NIDDM) having a fasting plasma glucose (FPG) level of less than 200 mg/dl. Total ketone body (TKB) levels significantly (P < 0.05) increased in the order of NGT, IGT, NIDDM, while the FPG and free fatty acid (FFA) concentrations were significantly (P < 0.05) higher in the NIDDM group than in the other two groups. In contrast, the insulin, glucagon and glycerol levels were comparable in the three groups. The plasma short-chain acylcarnitine (SCAC) concentration and the acylcarnitine/free carnitine (AC/FC) ratio were similar in the IGT and NIDDM groups, and significantly (P < 0.05) greater than those in the NGT group. The AC/FC ratio correlated significantly with the FPG and FFA, but not with the TKB. These results suggest that the combination of IGT with simple obesity may trigger the acceleration of hepatic ketogenesis in conjunction with an elevated SCAC and an increased AC/FC ratio. In addition, the data also imply that, in patients with mild NIDDM, factors other than the carnitines may play a greater role in enhancing ketonemia.

Acylation↗
PubMed1995

Bruceanols G and H cytotoxic quassinoids from Brucea antidysenterica.

Two new quassinoids, bruceanols G [1] and H [4], were isolated from Brucea antidysenterica, and their structures were elucidated by spectral evidence and chemical transformation. Bruceanol G exhibited significant cytotoxicity against the COLO-205 and KB neoplastic cell lines with ED50 values of 0.44 and 0.55 microM, respectively.

Animals↗
PubMed1995

Serum fatty acid composition in normal Japanese and its relationship with dietary fish and vegetable oil contents and blood lipid levels.

A survey was conducted on 110 normal Japanese adults (55 men and 55 women) to determine their caloric intake, dietary fat content and its origin (animal, plant, or marine). In addition, their blood lipid levels and fatty acid compositions were examined. Men in their 30s-50s consumed 2,600-2,800 calories and 60 g of fats, while women in the same age range consumed 2,000-2,200 calories and 52-58 g of fats. In both sexes, caloric, fat, and cholesterol intakes were lower for those in their 60s but protein and crude fiber consumption remained generally unchanged. When the dietary fats were classified according to origin, men and women in their 30s were found to consume less oil of marine origin. This appeared to be the result of a western style diet for Japanese adults in their 30s. Compared with men, women exhibited lower blood lipid levels. As age increased, the total cholesterol level of the blood rose in women. Thus the blood lipid level was generally equal in the two groups in their 60s. There was a positive correlation between the blood eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) levels and dietary consumption of fish oil. The marine/plant lipid ratio was positively correlated with the blood EPA/arachidonic acid ratio. Therefore, it was believed that the origin of the dietary fats consumed is a factor in determining the blood fatty acid profile. The linoleic acid (18:2), arachidonic acid (20:4), and 18:2 + 20:4 contents were negatively correlated to the total cholesterol level in the blood but positively correlated to the HDL-cholesterol level. Polyunsaturated fatty acids (18:2 + 20:4 + 20:5 + 22:6) were negatively correlated with the blood triglyceride level. From the findings presented above, we concluded that dietary fats not derived from animal sources should be classified into fish and vegetable oils to evaluate their dietary significance. We also noted that Japanese in their 30s consume less fish oil, indicating the western trend in their dietary lipid consumption.

Adult↗
PubMed1995

Production of term offspring by in vitro fertilization using old mouse spermatozoa.

We successfully produced offspring of old male BDF1 mice using in vitro fertilization. Although 7 old male mice (33 months of age) were infertile and revealed frequent degeneration in the seminiferous epithelia, 4 of them had spermatozoa in the caudae epididymides. The IVF rate of their sperm with eggs from young ICR mice was very high (82.0%). The production rate of offspring was also satisfactory (61.6%). The present study indicates that the IVF method is useful for producing offspring of aged male mice.

Aging↗
PubMed1995

In vitro fertilization and embryo development of Japanese field voles (Microtus montebelli).

Optimal conditions for in vitro fertilization of Japanese field voles (Microtus montebelli) were analysed. The medium used was a modified Krebs-Ringer bicarbonate devised for in vitro fertilization in rats. Ovulated eggs and epididymal spermatozoa were co-incubated in vitro at 37 degrees C under 5% CO2 in air for 6 h, and the eggs were fixed with 2.5% (w/v) glutaraldehyde, stained with 0.25% (v/v) acetolacmoid and examined for evidence of fertilization at the pronuclear stage. Although the fertilization rate with spermatozoa preincubated at 1-2 x 10(8) cells ml-1 for 2 h was very low (1-13%), it was significantly increased (43-51%, P < 0.05) when spermatozoa were preincubated at a lower concentration (1-2 x 10(7) cells ml-1). Furthermore, the fertilization rate was significantly higher with 1 mmol hypotaurine l-1 (74.0%) than without hypotaurine (44.4%, P < 0.05). Fertilization rates of spermatozoa preincubated at 1-2 x 10(7) cells ml-1 for 0.5 or 2 h were similar (69.0% and 73.6%), but a longer preincubation (10 h) resulted in a significantly lower fertilization rate (56.8%, P < 0.01). Vole spermatozoa preincubated for 2 h penetrated the zona pellucida 2 h after insemination, and the sperm heads became decondensed 3 h after insemination. At 6 h after insemination, male and female pronuclei were found in most penetrated eggs. When the eggs were left in the fertilization medium without washing and cultured for 96 h after insemination, they developed to two-cell (82.6%), four-cell (60.9%), eight-cell (23.2%) and morula/blastocyst (8.7%) stages in modified Krebs-Ringer bicarbonate supplemented with 1 mmol hypotaurine l-1.

Animals↗
PubMed1995

[An analysis on fat digestion in the upper small intestine after intragastric infusion of a test meal in patients with exocrine pancreatic insufficiency].

To clarify the mechanism of the fat maldigestion in 9 patients with exocrine pancreatic insufficiency, lipase activities, pH, and micellar lipids in the upper small intestinal contents were studied. The upper small intestinal pH was slightly less in patients with exocrine pancreatic insufficiency than in healthy controls. Lipase activities and micellar lipids were significantly reduced in patients with exocrine pancreatic insufficiency compared with in healthy controls. There was a significant correlation between serum cholesterol and micellar cholesterol concentrations. The results suggest that there is maldigestive state in the digestion-absorption process in patients with exocrine pancreatic insufficiency due to insufficiency of lipase secretion and that insufficiency of lipase secretion disturbs hydrolysis of triglyceride and prevents micelle formation and leads to reduced uptake of cholesterol into micellar phase and it is reflected in serum cholesterol.

Adult↗
PubMed1995

[The medial epicondyle of the humerus, an anatomical study].

A large variation in the shape of the medial epicondyle is encountered. This study was performed to investigate any role of the shape of medial humeral epicondyle in the etiology of osteoarthritis in the elbow, which can lead to cubital tunnel syndrome. A total of 71 humerus from 36 cadaveric specimens (mean age 75, ranging from 52 to 93) were used to study the morphological characterization of the medial humeral epicondyle. The specimens were divided into four types according to the index of medial epicondylar breadth and medial epicondylar length. A correlation was found between the angle of inclination of the sulcus nervi ulnaris and osteophyte formation in the medial epicondyle. This finding suggested that Type 2 (wider type) and 3 (longer type) might each contribute to the onset of osteoarthritis, resulting in cubital tunnel syndrome. However, we found some cases of Type 1 (wider and longer type) with a large angle and only minor osteophyte formation, suggesting that a large inclination angle of the sulcus nervi ulnaris alone was not an independent factor in osteophyte formation. Moreover from our results of measuring the distance between the tip of the medial epicondyle and the medial edge of the anterior medial collateral ligament origin, we concluded that medial epicondylectomy (King's method) without damaging this ligament should be performed at a point approximately 20% of the overall width of the medial epicondyle from the tip of the medial epicondyle.

Aged↗
PubMed1995

[31P-MR spectroscopy of bone and soft tissue lesions].

We studied 24 patients with bone and soft tissue lesions using 31P-MR spectroscopy (MRS). On image selected in vivo spectroscopy (ISIS) localized spectra, spectroscopic parameters were calculated: PME/noise ratio, gamma NTP/noise ratio, PME/gamma NTP and total metabolite signals (TMS). PME/noise, PME/gamma NTP and TMS were higher in malignant lesions than in benign ones. We set the criterion for malignancy as follows: PME/noise > 2.0 and gamma NTP/noise > 2.0 and PME/gamma NTP > 1.0. The accuracy of this criterion was 0.91 for malignant lesions and 1.0 for benign lesions. In six malignant tumors, MR spectra were obtained before and after chemotherapy. They were compared with the degree of tissue degeneration evaluated on pathological specimens. TMS after chemotherapy were markedly reduced in 3 cases. TMS seemed to reflect the degeneration of tumors. It could be said that MRS is a useful tool in differentiating from benign tumor lesions malignant bone or soft tissue lesions and in monitoring the effect of chemotherapy.

Adolescent↗
PubMed1994

Brain activation study by use of positron emission tomography in unanesthetized monkeys.

A system for the measurement of brain activity in conscious monkeys by positron emission tomography (PET) was established in the present study. The signal/noise ratio was maximal around 40 s for data acquisition in the PET scan with 15O-labeled water. When the monkey was stimulated by vibration and subtraction images of the data sets from regional cerebral blood flow (rCBF) changes in paired stimulation and control were superimposed on magnetic resonance images obtained from the same specimens, a somatotopic map corresponding to the sites stimulated was clearly demonstrated. Visual stimulation with a photic stimulator activated the corresponding regions of the primary visual cortex. Comparison of the activated sites and extents under the conscious state with those under anesthesia assured that the study is controllable; there was little unpredictable activation due to unlimited subject movement or to psychological effects.

Animals↗
PubMed1994

Tumor-derived components were responsible for suppression of ornithine decarboxylase activity in the rat wounded skin.

To elucidate the principal cause of delayed wound healing in a tumor-bearing host, the effect of Yoshida sarcoma-derived components on dermal wound healing was investigated in rats with the aid of ornithine decarboxylase (ODC) activity and in vivo bromodeoxyuridine (BrdU) labeling index. The ODC activity in the wounded skin decreased 3 and 7 days after intraperitoneal inoculation of Yoshida sarcoma cells (378.0 +/- 37.3 on Day 3, 280.0 +/- 140.0 on Day 7 vs. 809.3 +/- 109.5 pmol/mg protein/hour on Day 0). When administered 24 hours before and immediately after wounding, the crude nuclear component of the tumor cells significantly decreased the ODC activity in the wounded skin as compared with the control (185.9 +/- 159.8 vs. 534.0 +/- 59.1), but the non-nuclear component was not effective. When nuclear extracts of Yoshida sarcoma cells were intraperitoneally administered immediately after wounding, the 0.15 M or 0.35 M NaCl extract significantly suppressed ODC activity in the wounded skin (233.5 +/- 14.5 and 352.3 +/- 63.2 pmol/mg protein/hour, respectively) in comparison to the control (445.9 +/- 73.6). The BrdU labeling index of epidermal basal cells adjacent to the edge of the wound decreased up to 52% of the control by injection of the 0.15 M extract. It seems that tumor-derived nuclear components may be responsible for delayed wound healing which is commonly observed in cancer cachexia.

Animals↗
PubMed1994

Dietary analysis of Japanese patients with chronic pancreatitis in stable conditions.

In order to examine the malnutritional condition of outpatients with pancreatitis, a dietary investigation was conducted in Japanese patients with chronic pancreatitis (n = 38) and healthy subjects (n = 35) of the same age for 3-7 consecutive days, and the characteristics of their food intake were examined. The patients with pancreatitis took in less calories, fat, carbohydrate, and protein than the healthy subjects, by 900 kcal, 20 g, 150 g, and 20 g, respectively. On the other hand, the fat energy ratio in the patients was 20%, similar to that in the healthy subjects. Also, when the fat intake was classified according to origin, i.e., animal, marine, or plant, the proportions for animal (g) and plant (g) were low, while marine fat accounted for a significantly higher percentage than in the healthy subjects. The intake of cholesterol and Ca in the patients was significantly smaller than that in the healthy subjects, but no significant difference was observed in the intake per body weight of proteins and Ca. It seems, possible that the low calorie, low protein, low fat, and low carbohydrate intake may be factors in the malnutritional condition of the patients with chronic pancreatitis. Analysis of covariance and principal component analysis showed that the body weight of the patients was closely correlated with decreases of caloric intake and intake of carbohydrate. The above results revealed that low body weight in patients with chronic pancreatitis was closely related to the decrease of calorie and carbohydrate intake, in addition to maldigestion and malabsorption of nutrients.

Adult↗
PubMed1994

Clinical course and long-term prognosis of Crohn's disease in Japan.

The long-term outcome of Crohn's disease was reviewed in 74 patients who had a history of more than 10 years (range 10.8-27.3) since disease onset. The observation period was between 4.3 and 18.5 years, the mean and SD being 10.6 +/- 3.1 years. The means and SD of age at onset and final observation were 21 +/- 7 and 37 +/- 8 years, respectively. Fifty-eight of the 74 patients had not undergone bowel resection at the time of diagnosis; of these 58, 31 (53.4%) had an operation for the disease during the follow-up period. Thus, of the 74 patients, 47 (63.5%) (these 31, plus the 16 who had undergone bowel resection at the time of diagnosis) had an operation at least once during a follow-up period of 10 years or more. The cumulative operation rates 5, 10, and 15 years after onset in the 74 and 58 patients above were 18.9%, 6.9%, and 40.8%, and 34.8%, 49.1%, and 46.0%, respectively. The corresponding figures 5 and 10 years after diagnosis in all 74 patients and the 58 patients were 32.3% and 28.6% and 47.3% and 46.3%, respectively. There were no significant differences in the incidence of operation rate in relation to anatomical involvement. Cumulative reoperation rates 1, 3, 5, and 10 years after the first operation in the 31 patients who were operated on during the follow-up period were 3.4%, 6.9%, 25.5%, and 51.7%, respectively. Three patients died, the causes of death in one being directly related to Crohn's disease.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1994

Intestinal and extraintestinal complications of Crohn's disease: predictors and cumulative probability of complications.

Of 238 patients with Crohn's disease seen at our clinics from April 1973 to August 1988, 203 patients were selected for this study, since they fulfilled the following criteria: they had been followed up for more than 6 months as outpatients or had been treated as inpatients for more than 1 month. They were studied to elucidate: (a) the different types and incidence of various complications, (b) the factors related to complications present at the time of diagnosis, (c) predictors of new complications arising after diagnosis, and (d) the cumulative incidence of complications occurring during the course of the disease from the times of onset and diagnosis. Of the intestinal complications, perianal fistula was most common (33%), followed by strictures with dilatations of the proximal bowel (21%), and internal fistula (14%). Of the extraintestinal complications, menstrual disturbance was the most common (18% of the female patients), followed by arthritis (10%), and aphthous stomatitis (10%). As for the factors influencing complications present at the time of diagnosis, the pattern of bowel involvement was significantly correlated with the presence of intestinal stricture, while the erythrocyte sedimentation rate was significantly correlated with the presence of perianal fistula. A significant predictor of new complications arising after diagnosis was the general well-being of patients at the time of diagnosis. Patients who, at diagnosis, already have complications such as stricture, abdominal abscess, internal or external fistula, massive hemorrhage, and free perforation or anal lesions are more likely to develop new complications in addition to those present at diagnosis, compared with patients without any complications at diagnosis (P = 0.055).

Adult↗