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Biomedical subjects

K Imamura

Publications and source records attributed to K Imamura.

At least 109 records · Page 6Linked to original sources

Correlation between pancreatic endocrine and exocrine function and characteristics of pancreatic endocrine function in patients with diabetes mellitus owing to chronic pancreatitis.

CONCLUSION: Pancreatic endocrine capacities are remarkably disturbed in patients with pancreatic diabetes owing to calcific pancreatitis as opposed to those owing to noncalcific pancreatitis. Insulin secretion in calcific pancreatitis resembled that in insulin-dependent diabetes mellitus (IDDM), whereas insulin secretion in noncalcific pancreatitis resembled that in non-IDDM (NIDDM). The involvements of acinar cell and ductal cell function closely correlate with endocrine function (insulin and glucagon secretions) in chronic pancreatitis (pancreatic diabetes). BACKGROUND: We sought to clarify the differences of pancreatic endocrine function between pancreatic diabetes and primary diabetes, and to verify the correlations between pancreatic exocrine and endocrine dysfunction in patients with chronic pancreatitis. METHODS: Urinary C-peptide (CPR) excretion and fasting plasma glucagon levels in patients with pancreatic diabetes owing to calcific pancreatitis (19 cases) and owing to noncalcific pancreatitis (14 cases) were studied in comparison with those in patients with insulin-dependent diabetes mellitus (IDDM, 23 cases), noninsulin-dependent diabetes (NIDDM, 18 cases), and in healthy controls (11 cases). In addition, pancreatic exocrine function was investigated in patients with chronic pancreatitis (calcific and noncalcific) and in healthy controls. The correlation between pancreatic exocrine and endocrine function was studied. RESULTS: The urinary CPR excretion in controls was 94.9 +/- 20.5 micrograms/d. The urinary CPR excretion in calcific pancreatitis was 12.8 +/- 7.4 micrograms/d and it resembled that in IDDM (9.4 +/- 5.8 micrograms/d). The urinary CPR excretion in noncalcific pancreatitis was 41.5 +/- 30.1 micrograms/d, being similar to that in NIDDM (49.3 +/- 21.0 micrograms/d). The plasma glucagon level in calcific pancreatitis was 64.1 +/- 15.9 rho g/mL, which was significantly lower than the values in IDDM (111.2 +/- 50.2 rho g/mL) and NIDDM (96.7 +/- 21.9 rho g/mL). The plasma glucagon level in calcific and noncalcific pancreratitis (88.4 +/- 29.6 rho g/mL) were significantly lower than that in controls (129.8 +/- 21.6 rho g/mL). The residual capacities of acinar cells and ductal cells were strongly correlated with urinary CPR excretion and plasma glucagon concentration.

Adult↗

Identification and immunohistochemical localization of macrophage migration inhibitory factor in human kidney.

Macrophage migration inhibitory factor (MIF) was the first lymphokine identified in activated T-lymphocytes. MIF can induce proinflammatory cytokines, such as interleukin-1 and tumor necrosis factor-alpha. In this study, we identified MIF expression in a tissue specimen of a normal portion of a nephrectomized human kidney by reverse transcription-polymerase chain reaction (RT-PCR) and Western blot analysis. Furthermore, immunohistochemical study using an anti-human MIF polyclonal antibody demonstrated that MIF was mostly present in the renal tubule epithelial cells and, to a lesser extent, in Bowman's capsular epithelial cells. We also carried out immunohistochemistry on cultured human renal proximal tubule epithelial cells, which showed that MIF was present in the cytoplasm of the epithelial cells. These results suggest the possibility that MIF takes part in the mechanism of inflammation and immunological events in the human kidney.

Blotting, Western↗

Effect of hypotaurine on in vitro fertilization and production of term offspring from in vitro-fertilized ova of the Japanese field vole, Microtus montebelli.

The present study was proposed to establish new in vitro fertilization (IVF)-embryo transfer techniques for wild mammals. We demonstrated that IVF of the Japanese field vole, Microtus montebelli, is improved by hypotaurine, and that IVF vole embryos can develop to normal offspring after transfer to recipient females. The rate of IVF was significantly increased when 0.1 or 1 mM of hypotaurine was added during sperm preincubation and fertilization (p < 0.05). Preincubation of spermatozoa with 1 mM hypotaurine prior to oocyte insemination did not have a significant effect on fertilization rate (p < 0.01). At 96 h after insemination, most cultured embryos developed to the 2-cell stage (68-83%), but development to blastocysts was very low (0-3%) for all treatments. Although 43 living offspring were produced after transfer of IVF pronuclear embryos to recipients, the delivery rate of recipients was very low (21%). The litter size of pseudopregnant recipients that produced a litter was 4-11, and the rate of in vivo development of transferred embryos in the pregnant recipients was 41%. These results suggest that hypotaurine affects IVF rather than sperm preincubation and that IVF embryos can develop to normal offspring.

Animals↗

[Peripheral lymphocyte subset of patients with pancreatic diabetes mellitus--about a decreased ratio of T-LGL and ability of host defense].

Patients with diabetes mellitus (DM) often suffer from various and severe infection. Patients with pancreatic DM have malnutrition due to chronic pancreatitis. Therefore it is believed that patients with pancreatic DM have a lower ability of host defence to infectious diseases than normal subjects. We examined the primpheral lymphocyte subsets (T cell, B cell, NK cell, CD3+ 56+ T) of eighteen patients (males, age = 52.8 +/- 12.7 years old, mean +/- SD) with pancreatic DM by two color flow-cytometry to evaluate the lymphocyte function. Ratios of T cell (T%, 66.9 +/- 9.3%, mean +/- SD). B cell (B%, 13.1 +/- 5.8%) and NK cell (Nk%, 19.3 +/- 8.7%) to total peripheral lymphocytes of patients with pancreatic DM were not significantly different from those (T% = 66.4 +/- 7.8%, B% = 13.5 +/- 6.7%, NK% = 19.9 +/- 9.1%) of thirteen normal subjects (males, age = 51.2 +/- 13.1). CD3+56+ T cell % (4.1 +/- 1.9%) of patients with pancreatic DM was lower than that (6.0 +/- 3.0%) of normal subjects (p < 0.05). CD3+56+ T cells have cytotoxic activity and it is likely that this activity is similar to that of NK cells. These results suggested that a decrease in peripheral CD3+56+ T cell % is a factor showing a weak host defense mechanism to infectious diseases in patients with pancreatic DM.

Adult↗

Rectovesical fistula: a possible cause of postnatal lethality in F1 Dh/+ male mice between DDD female and DH (Dh/+) male.

To reveal a major cause of postnatal lethality in F1 Dh/+ male mice from DDD x DH (Dh/+) mating, the current study was performed. Dh/+ males with retarded growth appeared within a few days after birth. The unusual junction between the rectum and the urinary bladder (rectovesical fistula) was found in nine of 22 Dh/+ male mice, and the bladder contained unusual substances derived from the intestines. When the fistula was recognized, the urine was always gelatinous, and the anus was imperforate in eight cases, suggesting that an affected individual would have trouble in urination and evacuation. From these observations we conclude that the rectovesical fistula is a major cause of postnatal death in the F1 Dh/+ male.

Animals↗

Skeletal malformations caused by the Dh (Dominant hemimelia) gene in mice.

Morphological characterization of the skeletal malformations caused by the Dh gene was carried out. Skeletal preparations from newborn mice of Dh/Dh, Dh/+ and +/+ genotypes, and adult Dh/+ mice were examined. The Dh gene induced skeletal deformities at the axial regions from the thorax to the tail. Attachment of the ribs to the sternum was sometimes irregular, and normal segmentation of the sternum was also disrupted. Abnormal fusion of the ventral part of the rib was observed in some cases. Lumbar vertebrae were fewer in number and abnormal in shape. Although it was rare, a curled tail was also observed due to distortion of the caudal vertebrae.

Abnormalities, Multiple↗

High lethality of F1 (Dh/+) male mice from the cross between DDD female and DH (Dh/+) male.

The present study demonstrates the incidence of high lethality of F1 (Dh/+) male mice, the offspring of DDD females and inbred DH (Dh/+) males. Among the newborn pups, the numbers of F1 (Dh/+) males are comparable to those of mice having other genotypes (+/+ male, Dh/+ female and +/+ female), but many F1 (Dh/+) males died before weaning. On the other hand, among the F1 mice from the cross between DH (Dh/+) females and DDD males, there are no biased numbers of Dh genotype pups. These results suggest the existence of defects in the interaction between the male derived Dh gene and the genetic traits of the DDD female.

Abnormalities, Multiple↗

Isolation of a germline-transmissible embryonic stem (ES) cell line from C3H/He mice.

We have isolated three embryonic stem (ES) cell lines from C3H/He mice using mouse STO cells as a feeder layer. One ES cell line (H-1) was male, and two (H-2 and H-3) were female, as determined by polymerase chain reaction, in situ hybridization, and karyotype analyses. All were immunocytochemically reactive with a C3H strain-specific antibody. Injection of cells from the female ES H-3 line into C57BL/6 blastocysts yielded four chimeras with slight coat color chimerism. All chimeras were male, and as expected, no germline-transmission was observed. By contrast, when male ES H-1 cells were injected into the perivitelline space of 8-cell C57BL/6 embryos, one male mouse with overt coat color chimerism was recovered, and it produced ES H-1-derived offspring exclusively. This germline-transmissible C3H/He cell line represents a novel addition to those ES lines currently employed for gene manipulation studies of development.

Animals↗

[Reproductive and developmental toxicity study of a new antineoplastic agent, S-1 (I)--Fertility study in rats by oral administration].

S-1 is a newly developed antineoplastic agent consisting of the mixture of tegafur (FT), 5-chloro-2, 4-dihydroxypyridine (CDHP), and potassium oxonate (Oxo) in a molar ratio of 1:0.4:1. As part of a reproductive and developmental toxicity study of S-1, a fertility study was carried out in Sprague-Dawley rats. Twenty-four male rats were administered S-1 orally starting at 64 days before mating and 24 female rats were administered S-1 orally from 15 days before mating to day 7 of pregnancy at doses of 0, 1, 4, or 7 mg/kg/day (as a dose of FT) in order to investigate the effect of S-1 on the reproductive ability and development of embryos and fetuses. There were no dose-related changes in clinical signs. Body weight gains and food consumption were decreased and were associated with the decreased weights of thymus, testis and epididymis in male rats receiving S-1 at the 7 mg/kg/day group. In females, the only organ affected was the kidney at 7 mg/kg/day. There were no dose-related changes in copulation, fertility, pre-implantation loss and implantation. Decreases in live fetal body weight and retardation of fetal ossification were observed in the 7 mg/kg/day group. There were no dose-related changes in post-implantation loss, and no fetal malformations were observed. The results suggest that the non-observed effects dose level of S-1 for general toxicity in male and female rats in 4 mg/kg/day, for reproductive toxicity in adults is more than 7 mg/kg/day, and for developmental toxicity in utero is 4 mg/kg/day.

Abnormalities, Drug-Induced↗

A pylorus-retaining pancreatic head-duodenectomy for cancers of the duodenal papilla and the lower bile duct.

With the development of diagnostic technology, the surgical methods of cancer therapy have been expanded, and operations have been performed using a procedure corresponding to the stage of cancer to improve the postoperative QOL. A 79-year-old man with cancer of the duodenal papilla and obstructive jaundice, and a 63-year-old woman with cholangiocarcinoma in the lower region complicated by cholangitis caused by Candida underwent resections of the pancreatic head and duodenum, and pancreaticogastrostomies retaining the pylorus. Satisfactory results were obtained in both cases. The merits of the procedure were that there were few complaints, sufficient food could be ingested and the QCL was maintained. The benefits of pancreaticogastrostomy are that the anastomosis procedure is simple, the gastric wall is thicker than the jejunum and blood flow is plentiful. The dorsal gastric wall is located close to the pancreatic cut-end, therefore tension is not created, and the pancreatic enzymes are not activated because the anastomosis site does not contact the intestinal fluid. These characteristics should decrease the rate of anastomosis failure which can be a fetal complication. A safer operation is desirable, particularly for elderly patients or patients who have complications.

Aged↗

Appropriateness of total hip replacement in the United Kingdom.

The paper discusses the use of consensus models in determining the application of Total Hip Replacement surgery. The paper notes the wide national and international variation in use of this procedure but considers it in the broader context of reaching consensus on other surgical interventions.

Decision Making↗

[Chemotherapy for recurrent ovarian cancer].

The standard treatment for ovarian cancer is cytoreductive surgery followed by platinum-based combination chemotherapy. Although high response rates of this treatment are reported, 40-60% of patients achieving a complete response may relapse. Therefore, second-line chemotherapy is required. Second-line chemotherapy of patients with recurrent ovarian cancer should be based on their sensitivity to first-line chemotherapy and the platina-free interval. Patients who respond to the platina-based chemotherapy still may be sensitive to further platina-based chemotherapy. Patients who do not respond to the platina-based chemotherapy or who have relapses shortly after first-line chemotherapy should be considered clinically resistant to further platina-based chemotherapy. For such patients the chemotherapy regimen should be changed. These regimens include paclitaxel and hexamethylmelamine. The effect of intraperitoneal chemotherapy may depend on the size of the largest residual tumor nodule and the patient's sensitivity to previous chemotherapy.

Adenocarcinoma, Clear Cell↗

Angiotensin II type 1a receptor-deficient mice with hypotension and hyperreninemia.

Angiotensin (AT) II, the bioactive octapeptide in the renin-angiotensin system that plays a key role in cardiovascular homeostasis, exerts its multiple effects through the different types of AT receptors, AT1a, AT1b, and AT2. Previously, we showed chronic hypotension in angiotensinogen (the precursor of AT)-deficient mice and a dramatic increase in renin mRNA levels in its kidney, but it remains unclear which types of AT receptors regulate the blood pressure and renin gene expression. In order to elucidate the physiological roles of AT1a receptor, we generated mutant mice with a targeted replacement of the AT1a receptor loci by the lacZ gene. In the heterozygous mutant mice, the strong lacZ staining was found in the glomerulus and juxtaglomerular apparatus of the renal cortex, which coincided with that of the signals detected by in situ hybridization. Chronic hypotension was observed in the heterozygous and homozygous mutant mice, with 10 and 22 mm Hg lower systolic blood pressure, respectively, than that of wild-type littermates. Both levels of renin mRNA in the kidney and plasma renin activity were markedly increased only in the homozygous mutant mice. These results demonstrated that an AT1a-mediated signal transduction pathway is, at least in part, involved in the regulation of blood pressure and renin gene expression.

Angiotensin II↗