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Biomedical subjects

Y Kondo

Publications and source records attributed to Y Kondo.

At least 163 records · Page 9Linked to original sources
PubMed2000

An integrated rat genome map based on genetic and cytogenetic data.

In this study we combined three major rat genome maps, by adding 66 markers to the Kyoto Laboratory Animal Science map (KLAS map), and constructed an integrated map. The resultant integrated map consists of 5,682 redundant markers, spanning a genetic length of 2,028 cM. Eighty genetic markers were anchored to the cytogenetic map, fixing all the genetic maps in the physically correct orientation. This map encapsulates the progress in rat mapping studies in past years and offers useful information for QTL analysis. The map figures are available at http:/(/)www.anim.med.kyoto-u.ac.jp/.

Animals↗
PubMed2000

The vasocontractive action of norepinephrine and serotonin in deep arterioles of rat cerebral gray matter.

To examine the direct effects of norepinephrine (NE) and serotonin (5-HT) on the contractility of arterioles in the gray matter of the rat cerebrum, we micro-perfused arterioles in vitro and observed the changes in luminal diameter under the stop-flow condition with constant intraluminal pressure. While the average diameter of the lumen of arterioles was 39.9 +/- 9.7 microm (n=7) in Hepes-buffered saline, the average in 10(-7) M NE in the extraluminal solution changed into smaller in saline by 21.1 +/- 5.4% (n=7). The contractile effect of NE shows a dose-dependent curve between the 10(-7) and 10(-5) M. The contractile response to 10(-6) M NE was significantly reduced by yohinbin, an alpha2 blocker. 10(-6) M NE applied to the lumen also caused contraction of arterioles by 12.4 +/- 5.3% in diameter (n=5). 5-HT at 10(-7) M in the extraluminal solution caused contraction of arterioles by 10.9 +/- 4.4% in diameter (n=7). 5-HT in the extraluminal solution caused contraction of arterioles in a dose dependent manner between 10(-10) and 10(-6) M. The contractile effect of 5-HT at 10(-6) M was strongly reduced by 10(-6) M ketanserin, a 5-HT2 receptor antagonist. 5-HT applied to the lumen had no effect at all (n=6), however NE applied to the lumen caused contraction. These results strongly suggest that 5-HT plays a significant role in arteriolar contractility only from the cerebrospinal fluid (CSF) side, while NE is an important regulator of arteriolar contractility from both the CSF and blood circulation sides.

Adrenergic alpha-Antagonists↗
PubMed2000

Increased osteocyte apoptosis during the development of femoral head osteonecrosis in spontaneously hypertensive rats.

We investigated the presence of osteocyte apoptosis in the necrotic trabeculae of the femoral head of spontaneously hypertensive rat (SHR) using the in situ nick end labeling (TUNEL) method and transmission electron microscopy. The occurrence of osteonecrosis and ossification disturbance was significantly higher in SHR compared with Wistar Kyoto (WKY) rats, and Wistar (WT) rats used as control animals (P < 0.01). A high population of TUNEL positive osteocytes was detected mainly in 10- and 15-week-old SHRs. Sectioned examination of the femoral head of SHRs and WKY rats by electron microscopy revealed apoptotic cell appearances such as aggregation of chromatin particles and lipid formation. In contrast, a positive reaction was significantly lower in osteocytes in the femoral heads of WT rats (P < 0.01). Our results indicate that apoptosis forms an important component of the global pathologic process affecting the femoral head of SHR, which leads to osteonecrosis in this region.

Animals↗
PubMed2000

Accelerative effect of olive oil on adrenal corticosterone secretion in rats loaded with single or repetitive immersion-restraint stress.

The present study was performed to clarify the effects of dietary oils on physiological and metabolic changes induced by a stress, using one-time or repetitive water-immersion of restrained rats (single or repetitive stress) as an experimental stress load. In rats fed any test diets containing 20%) of the mixture of tripalmitin, tristearin, and corn oil (PSC), olive oil (OLI). safflower oil (SAF), and linseed oil (LIS) with repetitive stress loading, body weight gains and food intakes were generally reduced. The weights of the thymus and spleen also declined, but the adrenal weights were enhanced. Particularly, the increase in the adrenal weight of rats given the OLI diet was greater than of rats supplied with other diets. When the rats were loaded with the single or repetitive stress, the concentrations of urea, lipid peroxide, and corticosterone in the plasma were increased in rats fed any of dietary oils. The rise of plasma corticosterone level was especially great in rats fed the OLI diet. The concentrations of total cholesterol (T-CHOL) and triglyceride (TG) in the plasma and liver generally tended to be higher in rats fed the OLI diet than in rats given the other diets with and without stress exposure. Plasma corticosterone concentration was correlated to the adrenal weight (r=0.87, p<0.05). This study showed that OLI especially enhanced the adrenal weight in rats exposed to the repetitive stress and further raised the increased secretion of adrenal corticosterone in rats loaded with the single or repetitive stress compared with the other oils. The mechanism explaining these actions of OLI was inferred to be related to the levels of T-CHOL and TG in the plasma and liver generally enhanced by stress.

Adrenal Cortex↗
PubMed2000

Intraductal papillary tumors of the major salivary glands: case reports of benign and malignant variants.

Intraductal papilloma is an extremely rare benign salivary gland tumor that occurs most commonly in the minor salivary glands. To our knowledge, a malignant counterpart of intraductal papilloma has not been described previously. We report one case each of benign and malignant intraductal papillary tumors. The benign tumor occurred in the sublingual gland and was a typical example of intraductal papilloma, with the exception that we found no previously published reports of this type of tumor in this location. The other patient had a left parotid gland tumor that was architecturally similar to the intraductal papilloma, with the addition of cytologic atypia, intraductal extension, microinvasion, and lymph node metastases. This tumor was diagnosed as intraductal papillary adenocarcinoma with an invasive component. Both patients were alive and well without evidence of recurrence 2 years and 6 months (case 1) and 6 years (case 2) after surgery. Immunohistochemical examination revealed that the tumor cells resembled duct luminal cells in both cases. The 2 tumors had different immunoreactivities for carcinoembryonic antigen, p53, and Ki-67. The malignant counterpart of intraductal papilloma should be considered in the differential diagnosis of salivary gland tumors with a predominantly papillary structure, even though this tumor is extremely rare.

Adenocarcinoma, Papillary↗
PubMed2000

"Amphiphilic" Cleavage of gamma-Stannyl Ketones with ATPH/RLi: Application to Enone Fragmentation by the Conjugate Addition - Cleavage Sequence.

The use of a combined Lewis acid/base system consisting of aluminum tris(2,6-diphenylphenoxide) (ATPH) and MeLi has allowed the electrophilically activated nucleophilic ("amphiphilic") cleavage of C(alpha)-C(beta) bonds in gamma-stannyl ketones. Through combination with the conjugate addition of alpha-stannyl carbanion to enone, this approach constitutes a novel two-step conjugate addition - cleavage sequence that leads to functionalized ketones (see reaction).

Journal Article↗
PubMed2000

Suppression of a high-affinity transport system for manganese in cadmium-resistant metallothionein-null cells.

Cadmium is a hazardous heavy metal existing ubiquitously in the environment, but the mechanism of cadmium transport into mammalian cells has been poorly understood. Recently, we have established a cadmium-resistant cell line (Cd-rB5) from immortalized metallothionein-null mouse cells, and found that Cd-rB5 cells exhibited a marked decrease in cadmium uptake. To investigate the mechanism of altered uptake of cadmium in Cd-rB5 cells, incorporation of various metals was determined simultaneously using a multitracer technique. Cd-rB5 cells exhibited a marked decrease in manganese incorporation as well as that of cadmium. However, the reduced uptake of manganese was observed only at low concentrations, suggesting that a high-affinity component of the Mn(2+) transport system was suppressed in Cd-rB5 cells. Competition experiments and kinetic analyses revealed that low concentrations of Cd(2+) and Mn(2+) share the same high-affinity pathway for their entry into cells. The mutual competition of Cd(2+) and Mn(2+) uptake was also observed in HeLa, PC12, and Caco-2 cells. The highest uptake of Cd(2+) and Mn(2+) by parental cells occurred at neutral pH, suggesting that this pathway is different from a divalent metal transporter 1 that can transport various divalent metals including Cd(2+) and Mn(2+) under acidic conditions. These results suggest that a high-affinity Mn(2+) transport system is used for mammalian cellular cadmium uptake, and that the suppression of this pathway caused a marked decrease in cadmium accumulation in cadmium-resistant metallothionein-null cells.

Animals↗
PubMed2000

Enhancement of angiogenesis, tumor growth, and metastasis by transfection of vascular endothelial growth factor into LoVo human colon cancer cell line.

The expression of vascular endothelial growth factor (VEGF), a highly potent angiogenic molecule, is thought to be correlated with the development of colon cancer; however, direct evidence for a role of VEGF in metastasis is lacking. This study was designed to more directly establish the role of VEGF in the growth and metastasis of human colon cancer using a genetically engineered cancer cell line. A stable VEGF gene-transfected human colon cancer cell line, LoVo, was made by genetic manipulation using eukaryotic expression constructs designed to express the complete VEGF121 cDNA in the sense orientation. Transfected clones were screened for VEGF121 mRNA expression by Northern blot analysis and for VEGF121 protein expression by Western blot analysis. Consequently, we obtained S17 cells that expressed a high level of both VEGF mRNA and VEGF protein. A vector-transfected clone (V7 cell) was used as a control. The experiment with the dorsal air sac method revealed that S17 cells elicited a stronger directional out-growth of capillaries than V7 cells. S17 cells formed faster-growing tumors than did V7 cells when xenografted s.c. into nude mice, although there was no significant difference in their in vitro proliferation. Tumors derived from S17 cells had more vascularity, as assessed by counting capillary vessels after staining with factor VIII, than did tumors derived from V7 cells (P < 0.05). With regard to the metastatic potential, S17 cells exhibited a higher capacity for both hepatic metastasis after the splenic portal inoculation and peritoneal dissemination after i.p. injection than did V7 cells. However, S17 cells showed no apparent metastasis, despite their rapid growth after orthotopic implantation. In conclusion, the present study showed clearly that VEGF plays an important role in cancer growth due to stimulation of angiogenesis by accelerating cell growth after reaching the target organs.

Animals↗
PubMed2000

Use of cultured tubular cells isolated from human urine for investigation of renal transporter.

AIM: To facilitate the understanding of the transporter function of human renal tubular cells, we have developed a simple method using primary cultured proximal tubule (PT) cells isolated from voided urine. METHODS: PT cells grown to confluence on glass coverslips could be identified by parallel arrays of spindle cells and hemicyst formation. Brush-border gamma-glutamyl transpeptidase (gammaGTP) activity was histochemically identified. Apical membrane Na+/H+ exchanger (NHE) activity was measured by monitoring changes in intracellular pH (pHi) after an acid load in a single cell level using the pH-sensitive dye 2'7'-bis-(2-carboxyethyl)-5.6'carboxyfluorescein (BCECF). RESULTS: Amiloride and 5-(N-ethyl-N-isopropyl) amiloride (EIPA) inhibited the NHE activity with half-maximal inhibition values (IC50) of 15.3 and 4.0 microM, respectively. NHE-3 mRNA was detected by the RT-PCR technique in clonally proliferated PT cells. CONCLUSION: These results suggest that cultured PT cells isolated from human urine express amiloride-resistant NHE-3 activity on the apical membranes, which can be compared to functional properties of PT in vivo. Our experimental strategy offers a useful experimental approach to investigating human renal tubular transport function in vitro.

Adult↗
PubMed2000

Mouse macrophage metalloelastase gene transfer into a murine melanoma suppresses primary tumor growth by halting angiogenesis.

Mouse macrophage metalloelastase (MME) has been associated with the generation of angiostatin, an internal fragment of plasminogen, which inhibits angiogenesis. To clarify whether tumor cells that consistently generate MME can suppress angiogenesis and, therefore, inhibit the growth of primary tumors in vivo, we transfected a cDNA coding for MME into murine B16-BL6 melanoma cells that grow rapidly and are MME deficient. The generation of active MME in MME-transfected clones was confirmed by immunoprecipitation followed by in vitro cleavage of plasminogen. Subcutaneous implantation of these stable clones in C57BL/6 mice inhibited primary tumor growth by an average of 73% (P = 0.00002), which directly correlated with a significant reduction of blood vessel formation (approximately 76%) in such tumors. Microangiography revealed massive angiogenesis in control tumors (mock and vector); however, in MME-transfected primary tumors it demonstrated a decreased and disrupted vascular network. Western blot analysis using a specific anti-mouse angiostatin antibody demonstrated a strong 38-kDa immunoreactive band in MME-transfected tumors and in the serum of mice bearing those tumor cells. These results show that placing MME gene directly into B16-BL6 melanoma cells is an effective approach to suppress primary tumor growth in vivo because it halts angiogenesis. Our data provide a feasible and promising strategy for gene therapy of cancer by targeting tumor vasculature.

Angiostatins↗
PubMed2000

[Delayed posttraumatic high flow priapism: a case report].

A 21-year-old male complained of persisting erection. A urethral balloon catheter had been for 3 weeks after indwelt urethral injury by a skateboard, and he was hospitalized because of penile erection persisting after removing the catheter. High flow priapism was suspected by intracavernous blood gas study and color Doppler ultrasound study. Selective internal pudendal arteriography revealed a leakage of contrast medium at the base of penis. He was treated with selective embolization of bilateral internal genital arteries using gelatin sponges and achieved detumescence. Normal potency was evident 3 months later by examining nocturnal penile tumescence.

Adult↗
PubMed2000

[A case of tuberculous epididymitis which was difficult to distinguish from a testicular tumor].

A 70-year-old man complaining of painless right scrotal swelling was referred to our hospital. He had a past history of left nephrectomy for renal tuberculosis at the age of 28. Power Doppler ultrasonography revealed a hypoechoic and hypovascular tumor with septa in the scrotum. We suspected a right testicular tumor and therefore, performed a right high inguinal orchiectomy. On macroscopic findings, the fluid of the tumor was yellowish and mucinous and the ipsilateral testis was remarkably atrophic. The pathological diagnosis was tuberculous epididymitis with central necrosis. In recent years, tuberculous epididymitis is rare, and this case was considered to be the first report of power Doppler ultrasonographic findings in tuberculous epididymitis.

Aged↗
PubMed2000

[Non-Hodgkin's lymphoma in two married couples].

Couple 1: A 74-year-old woman was diagnosed as having diffuse large B-cell lymphoma (DLBL) by left axillary lymph node biopsy. About 6 months later, DLBL was also diagnosed in her 79-year-old husband by right submandibular lymph node biopsy. Although the wife achieved partial remission with chemotherapy, she died due to disease progression. The husband's disease was chemotherapy-resistant, and he died of renal failure. Couple 2: An 86-year-old man was diagnosed as having DLBL by left axillary lymph node biopsy. About 4 years later, DLBL was also diagnosed in his 86-year-old wife by left axillary lymph node biopsy. Both the husband and the wife received chemotherapy. The husband is currently alive in complete remission, and although the wife achieved partial remission, she died due to disease progression. In both of these couples, it was considered unlikely that Epstein-Barr virus or human T-cell lymphotropic virus type I was related to the development of non-Hodgkin's lymphoma, and no environmental factors were confirmed to be involved. It is postulated that other unknown factors or agents may be associated with the development of lymphoma in married couples.

Aged↗
PubMed2000

Mitogenic action of lysophosphatidic acid in proximal tubular epithelial cells obtained from voided human urine.

Focal tubular cell multiplication at sites on an injured nephron is a critical event in the recovery phase following acute tubular necrosis. During this process, numerous viable tubular cells exfoliate and are shed into the urine. Lysophosphatidic acid (LPA) is generated in the plasma membrane of injured cells and acts as an intercellular mediator of various biological processes, including inflammation, proliferation and repair. In the present study, exfoliated proximal tubule (PT) cells were isolated from human urine and the mitogenic effects of LPA were investigated as a model of repair and proliferation following renal injury. LPA stimulated a 23. 5% increase in DNA synthesis, a 29.4% increase in cell number and an 86.6% decrease in cAMP content. All of these responses were pertussis toxin sensitive, indicating the involvement of G(i)-type G-proteins in LPA signalling. Conversely, the LPA-induced DNA synthesis and the decrease in intracellular cAMP content were insensitive to wortmannin, an inhibitor of phosphatidylinositol 3-kinase (PI3K), suggesting a mitogenic response via PI3K-independent mechanisms. Furthermore, we detected specific mRNA transcripts for the recently cloned human LPA-receptors, endothelial differentiation gene (Edg)-2 and Edg-4 (Edg-2>>Edg-4) by reverse transcription-PCR in PT cells. Our data suggest that LPA may behave as a local growth factor in PT cells following tubular injury.

Cell Division↗
PubMed2000

[Successful TS-1 therapy in a patient with non-resectable gastric cancer and renal dysfunction].

A 73-year-old woman presented to our hospital with epigastric pain and swelling of the left upper limb. Enlarged lymph nodes with adhesion were palpable in the left cervical region and supraclavicular fossa. Tests were performed with the thought that the left upper limb swelling was secondary to venous compression by the enlarged lymph nodes. Gastroscopy detected a torose lesion on the anterior wall at the gastric angle and biopsy revealed that it was moderately differentiated adenocarcinoma. MRI showed metastasis to the sixth cervical vertebra and the first thoracic vertebra. Based on these findings, she was diagnosed as having progressive gastric cancer with metastasis to Virchow's lymph node and the cervical and thoracic vertebrae. Because it was considered impossible to perform radical gastrectomy, chemotherapy was given. Since renal dysfunction was suggested by a serum Cr of 1.5 mg/ml and a Ccr of 26.2 ml/min, TS-1 was administered at a lower dose (50 mg/day for 4 weeks) than usual, followed by 2 weeks off therapy to complete 1 course. During TS-1 therapy, the plasma 5-FU concentration at 4 h was 129.5 ng/ml, indicating that an effective plasma level of the drug was achieved. TS-1 therapy was considered effective because it reduced the diameter of the primary tumor and the lymph node metastasis, with only mild adverse reactions including myelosuppression.

Adenocarcinoma↗
PubMed2000

[A case of pseudo-Bartter's syndrome with marked nephrocarcinosis].

A 38-year-old woman was admitted to our hospital on October 21, 1996 for evaluation of thirst, bilateral backache and a feeling of abdominal fullness. She had hypokalemia, normotension, hyperreninemia, hyperaldostronism and hyperplasia of the juxtaglomerular apparatus on renal biopsy. Ultrasonography, intravenous pyelography and computed tomography showed marked bilateral renal calcification. Considering her history of persistent soft stool caused by chronic laxative abuse for 15 to 16 years and past diuretic abuse for several years since 1986, we diagnosed her as pseudo-Bartter's syndrome with nephrocarcinosis. The value of urinary Ca excretion was in the normal range, and acidification disturbance in NH4Cl loading test was revealed. In addition, she had taken analgesics for 2 to 3 years and interstitial nephritis on renal biopsy was seen. It is thus suggested that the cause of nephrocarcinosis in this case was the reduction of Ca solubility in the tubular cavity induced by incomplete renal tubular acidosis associated with analgesic nephropathy or interstitial nephritis caused by hypokalemia.

Acidosis, Renal Tubular↗