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Biomedical subjects

K Maeda

Publications and source records attributed to K Maeda.

At least 1,009 records · Page 56Linked to original sources

Fulminant hepatic failure during perinatal period in a pregnant woman with Wilson's disease.

Wilson's disease associated with hepatic failure is not common and the underlying mechanism triggering the event is not known at present. We treated a 28-year-old Japanese woman with Wilson's disease who developed hepatic failure associated with hemolytic crisis just after delivery. She was diagnosed as having Wilson's disease at 12 years of age, at which time she started taking D-penicillamine. She had previously delivered two children without difficulty. When she found out she was pregnant this time, she stopped taking D-penicillamine in contrast to taking it faithfully during her first two pregnancies. On the day of delivery of her full-term baby, jaundice developed accompanied with severe hemolytic crisis. Plasma exchanges and blood transfusion were performed and D-penicillamine administration was started again. She gradually recovered and apparently was following a good clinical course. However, on day 30 the second hemolytic crisis occurred and subsequent liver failure led her to death on day 50. At autopsy her liver was cirrhotic and showed massive necrosis. Prophylactic oral administration of D-penicillamine and careful observation are therefore recommended to prevent hemolytic crisis during the perinatal period.

Adult↗

Extracellular and cell-associated localizations of plasminogen activators and plasminogen activator inhibitor-1 in cultured endothelium.

The extracellular localizations of urokinase-type plasminogen activator (uPA), tissue-type plasminogen activator (tPA), and plasminogen activator inhibitor-1 (PAI-1) were examined in cultured bovine capillary endothelial cells (BCEs) by an immunofluorescence method using BCEs treated with or without saponin and focal contact preparations. The specific immunofluorescence of cell surface uPA showed a patchy or strand-like distribution and was colocalized with vinculin strands indicating that uPA secreted from BCEs was mainly deposited at the cell surface of focal contacts. BCEs at a subconfluent density showed a higher intensity of specific immunofluorescence for uPA than when they were at a confluent density. tPA was observed over the dorsal surface of cultured BCEs and accentuated at their margins, suggesting that tPA was diffusely distributed on the luminal surface of BCEs in vivo. PAI-1 was distributed in the extracellular matrix under cultured BCEs. These findings suggest that uPA and PAI-1 are located under BCEs participating in the regulation of proteolytic activities provoked by plasminogen-PAs-plasmin system in vivo. The localization of tPA appears to be consistent with its function, which is to maintain the fluidity of the blood and to initiate thrombolysis in vivo.

Actins↗

Effects of intracerebroventricular administration of opiate receptor antagonists on the suppressed pulsatile LH release during acute fasting in ovariectomized estradiol-treated rats.

The involvement of specific opiate receptors in the suppression of LH release during acute fasting in ovariectomized estradiol-treated rats was examined by intracerebroventricular (i.c.v.) administration of opiate receptor antagonists that exert a specificity directed mainly, although not absolutely, towards the delta-, kappa- or mu-opiate receptors. Fasting for 48 h significantly decreased mean plasma LH levels in estradiol-treated animals by increasing sensitivity to the negative feedback effect of estradiol. Injecting i.c.v. the mu-opiate receptor antagonist naloxone (10 or 100 nmol in 2 microliters of saline) blocked the inhibitory effect of fasting on pulsatile LH release and reinstated LH pulses. On the other hand, i.c.v. administration of the same dosages of a delta-opiate receptor antagonist ICI 174,864 or a kappa-opiate receptor antagonist WIN 44441-3 did not have any effect. These results suggest that the increased sensitivity of the LH-releasing mechanism to the negative feedback effect of estradiol during fasting involves the endogenous opioids mainly through the selective activation of the mu-opiate receptors.

Animals↗

A multifocal schwannoma of the masseteric nerve causing hemicrania.

A case is reported of schwannoma of the right masseteric nerve, invading the pterygopalatine fossa and the parapharyngeal space through the mandibular notch in a 61-year-old woman. The tumor in this case was composed of four various-sized interconnected nodules, simulating a string of beads. The tumor was the cause of the patient's chronic hemicrania, as confirmed by the relief from and disappearance of head pain after surgical removal of the tumor. The most important aspects of this case are the anatomic site of the schwannoma and its uncommon clinicopathologic manifestations; this tumor originated from the masseteric nerve and is the first case reported to straddle the mandibular notch.

Cranial Nerve Neoplasms↗

FUT-175 as a potent inhibitor of C5/C3 convertase activity for production of C5a and C3a.

We examined the inhibitory effect of FUT-175 on the C3/C5 convertase activity of the cobra venom factor-derived enzyme CVF,Bb by measuring C5b6-mediated reactive lysis of unsensitized guinea pig erythrocytes and by measuring directly the released fragments C3-des-Arg and C5a-des-Arg. In this study, we showed that the concentration of 4.5 X 10(-6) M of FUT-175 caused 50% inhibition of C5 convertase activity of CVF,Bb in reactive hemolysis assays, and that 4.0 X 10(-6) M FUT-175 caused 50% inhibition of the production of C3a and C5a generated by the C3/C5 convertase activity of CVF,Bb.

Animals↗

A histochemical study of bone remodeling during experimental apical periodontitis in rats.

An apical periodontitis experimental model was produced by means of opening the pulp chamber of the mandibular first molar in Wistar strain rats. In particular, the behavior of bone tissue in the vicinity of the root apex was investigated histochemically, ultrastructurally, and quantitatively. In addition, in order to demonstrate the effects of prostaglandin on the formation process of apical periodontitis, we examined the effects of indomethacin on bone remodeling during experimental apical periodontitis. These experiments suggested that prostaglandin may stimulate osteoclastic bone resorption and that the relationship between bone resorption and formation in apical periodontitis is a coupling phenomenon.

Acid Phosphatase↗

Autosomal dominant crystalline dystrophy.

A black woman was identified with a tapetoretinal degeneration with sparkling intraretinal crystals, retinal pigment epithelial and choroidal atrophy, night blindness, color vision abnormalities, and paracentral scotomas. This constellation of findings is most consistent with the diagnosis of Bietti's crystalline dystrophy. Eight other family members were identified with intraretinal crystals similar to those seen in the proband but in varying degrees of progression. Transmission electron microscopy of circulating lymphocytes in several patients demonstrated crystals and granular osmophilic material of unknown composition contained within abnormal lysosomes. These crystals are similar in appearance and location to those seen in cholesterol ester storage disease. This family demonstrates an autosomal dominant inheritance pattern, as well as other differences from classic Bietti's crystalline dystrophy. The authors, therefore, suggest that this new entity be named autosomal dominant crystalline dystrophy.

Adult↗

Kabuki make-up syndrome (Niikawa-Kuroki syndrome) with cleft lip and palate.

Kabuki make-up syndrome (Niikawa-Kuroki syndrome), recognized in Japan in 1981, is characterized by mental and growth retardation with specific craniofacial malformation such as lower palpebral eversion and depressed nasal tip. In this paper we describe a case associated with cleft lip and palate. Attention should be paid by maxillofacial surgeons to this syndrome, since 41% of the cases have been associated with cleft lip and palate (Niikawa et al., 1988; Tonoki and Niikawa, 1988).

Cleft Lip↗

Oral sorbent suppresses accumulation of albumin-bound indoxyl sulphate in serum of haemodialysis patients.

Serum indoxyl sulphate, which is markedly accumulated in haemodialysis patients, cannot be removed efficiently by haemodialysis due to its albumin-binding property. To determine whether an oral adsorbent (AST-120) can decrease its serum concentration, AST-120 was administered to haemodialysis patients. The patients given AST-120 showed significantly reduced serum concentration of indoxyl sulphate as compared to control haemodialysis patients, even though the serum concentrations of urea nitrogen and creatinine did not decrease significantly in the patients treated with AST-120. The haemodialysis patients with generalised pruritus showed an amelioration of itching after administration of AST-120. These results showed that AST-120 was effective in reducing the serum concentration of albumin-bound indoxyl sulphate in haemodialysis patients by adsorption of indole, a precursor of indoxyl sulphate, in the intestines, and that it relieved itching in haemodialysis patients with generalised pruritus.

Administration, Oral↗

The modified buccal musculomucosal flap method for cleft palate surgery.

We have reported previously on a palatoplasty method, called the T-shaped musculomucosal buccal flap method, for the primary repair of a cleft palate. This method has been used on more than 90 patients, and satisfactory outcomes have resulted in terms of maxillar development, the prevention of fistulation, and verbal functions. However, 14.3 percent of these patients exhibited a velopharyngeal incompetence that showed no potential improvement through training. In the majority of these patients, the entire raw surface of the oral cavity side could not be covered with a buccal musculomucosal flap, and as a result, postoperative contraction of the soft palate occurred. Thus a new surgical method has proven effective in which both buccal musculomucosal flaps are used as an oral lining, the nasal mucosa having been extended by Z-plasty. We have performed 25 operations using this new method and have observed no postoperative contractions of the soft palate, notwithstanding two cases (8.0 percent) of postoperative fistulation.

Articulation Disorders↗

Production and characterization of tumor infiltrating lymphocyte clones derived from B16-F10 murine melanoma.

The adoptive transfer of tumor infiltrating lymphocytes (TIL) in conjunction with recombinant interleukin-2 (rIL-2) for the treatment of advanced cancer has recently been under intense investigation. Despite extensive research, the precise surface phenotype of TIL remains to be fully defined. To elucidate this unsolved problem, we established 11 TIL clones derived from rIL-2 expanded TIL obtained from B16-F10 murine melanoma tumors. These clones could be divided phenotypically into four groups: CD8 (+) T-cell clones, natural killer (NK)-cell clones, NK-like CD8 (+) T-cell clones, and double negative T-cell clones. Functionally, CD8 (+) T-cell clones demonstrated specific cytotoxic activity against B16-F10 melanoma cells, whereas NK-cell clones and double negative T-cell clones demonstrated only non-specific cytotoxic activity against NK-sensitive YAC-1 cells. NK-like CD8 (+) T-cell clones showed dual cytotoxic activity. Clones T1 [a CD8 (+) T-cell clone] and T2 [an NK-like CD8 (+) T-cell clone] which had cytotoxic activity against B16-F10 melanoma cells, demonstrated a proliferative response against immunoblotted B16-F10 melanoma antigens, whereas clones T7 (an NK-cell clone) and T10 (a double negative T-cell clone), which had no cytotoxic activity against B16-F10 cells, demonstrated no proliferative response against them. Winn assays revealed that only the CD8 (+) T-cell clone (T1) had an antitumor effect in vivo, whereas the double negative T-cell clone (T10) and NK-like CD8 (+) T-cell clone (T2) stimulated tumor growth in vivo. Adoptive immunotherapy using tumor-specific, highly cytotoxic TIL clones may represent a useful future immunotherapeutic option for the treatment of human tumors.

Adenocarcinoma↗

Interleukin-2-inducible killer activity and its regulation by blood monocytes from autologous lymphocytes of lung cancer patients.

The ability of blood lymphocytes of newly diagnosed lung cancer patients to respond to interleukin 2 (IL-2) to become IL-2-activated killer (LAK) cells and its regulation by autologous monocytes were examined. LAK activity was measured by 51Cr release assay. The abilities of lymphocytes among blood mononuclear cells (MNC) of subjects of different ages without malignancies to generate LAK activity against NK-cell resistant Daudi cells and lung adenocarcinoma (PC-9) cells were very similar. The LAK activity of blood MNC of lung cancer patients was also nearly the same as that of blood MNC of control subjects. There was no significant difference in IL-2-inducible LAK activity between MNC of patients with small cell lung cancer (SCLC) and those of patients with non-SCLC. Monocytes and lymphocytes were separated from blood MNC on a one-step Percoll gradient. Monocytes of lung cancer patients were found to augment in vitro induction of LAK activity by IL-2 of autologous blood lymphocytes. In contrast, endotoxin-stimulated monocytes suppressed LAK induction of autologous lymphocytes of cancer patients. These findings suggest that administration of IL-2 and LAK cells induced in vitro may be of benefit in the treatment of lung cancer.

Aged↗

The effect of intracerebroventricular administration of somatostatin on prolactin and TSH release in rats.

We investigated the effect of intracerebroventricular (icv) administration of somatostatin (SRIF) on prolactin (PRL) and thyroid-stimulating hormone (TSH) release in freely moving rats chronically cannulated with an atrial catheter. The plasma PRL levels were significantly elevated following the icv administration of 0.5 microgram SRIF. No further increase in PRL following the icv administration of SRIF were found in the rats in the course of repeated intravenous of injection of 5.0 mg/kg sulpiride, a specific D2 receptor antagonist. On the other hand, the injection of 5.0 micrograms SRIF resulted in no significant change in the plasma TSH levels. These results suggest that the effect of SRIF on PRL release was exerted through brain D2 receptors.

Animals↗

Acute tubulointerstitial nephritis in two siblings and concomitant uveitis in one.

Two sisters with acute tubulointerstitial nephritis (ATIN) are reported. The elder sister had concomitant uveitis which recurred twice. The younger sister became ill five years after the onset in the elder. Both patients had identical HLA haplotypes and also suffered from mild chronic sialoadenitis. A renal biopsy specimen of the elder sister showed not only marked interstitial infiltration of immunoglobulin-containing mononuclear cells but also immunecomplex-related glomerulonephritis. The younger sister had immune complexes in the serum. These findings suggest that glomerulonephritis and uveitis may be secondary phenomena of ATIN with participation of circulating immune complexes. Once the uveal involvement has occurred, uveitis may undergo relapses without any renal manifestations.

Acute Disease↗

Solitary metastatic ovarian carcinoma of the spleen: a case report.

Carcinomatous metastatic involvement of the spleen usually indicates a widespread malignant disease. Solitary metastatic lesions in the spleen are exceedingly rare. The literature contains fewer than 16 cases. In this paper we report a case of a solitary metastatic lesion of the spleen arising from a serous cystadenocarcinoma of the ovary 5 years after the initial operation. A splenectomy was performed followed by smooth postoperative course.

Aclarubicin↗

Effects of chronic exposure ultraviolet-A including 2% ultraviolet-B on free radical reduction systems in hairless mice.

Chronic ultraviolet (UV) irradiation is known to cause a variety of changes in the skin, including wrinkles, pigmented spots and carcinogenesis. To explore time dependent changes in several parameters with chronic UV irradiation, we examined the molecular changes in connective tissue, intracellular defence enzymes and free radical antioxidant substances in hairless mice skin caused by chronic exposure to UV-A including 2% UV-B. Connective tissue changes were estimated using hydroxyproline and isodesmosine assays as a measure of collagen and elastin concentrations, respectively. After 6 weeks irradiation, the insoluble collagen and elastin were both substantially elevated, as were the activities of glutathione peroxidase (GSH-Px) and superoxide dismutase (SOD). Continued UV irradiation resulted in a steady decline in SOD and lipid soluble antioxidants, while the GSH-Px remained elevated, suggesting that SOD and lipid soluble antioxidants in the skin may be involved in protecting it from UV damage and deteriorate with chronic irradiation.

Aging↗