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Biomedical subjects

M Maeda

Publications and source records attributed to M Maeda.

At least 721 records · Page 40Linked to original sources
PubMed1993

Antitumor activity of a new series of platinum complexes: trans(+/-)-1,2-cyclohexanediammineplatinum(II) conjugated to acid polysaccharides.

Complexes with trans(+/-)-1,2-cyclohexanediammineplatinum(II) conjugated to acid polysaccharides were synthesized and their antitumor activities were tested in female CDF1 mice with intraperitoneal leukemia L1210 cells. Platinum was released from the polymers under physiological conditions, with half-lives from 3.3 to 19.3 h. A hyaluronic acid-supported complex was the most effective against the tumors (all six mice survived for 60 days). The group given a chondroitin polysulfate-supported complex had five survivors, the chondroitin sulfate A group also had five, the chondroitin sulfate C group had three and the heparan sulfate group had two. Part of the antitumor activity was due to increased efficacy of the polymers. The bioavailability of these complexes is high. Therefore, acid polysaccharides should be a good system for delivering antitumor platinum complexes.

Animals↗
PubMed1993

Enhanced antitumor effect of recombinant human tumor necrosis factor in combination with recombinant human granulocyte colony-stimulating factor in BALB/c mice.

The synergistic antitumor effect of tumor necrosis factor (TNF) and granulocyte colony-stimulating factor (G-CSF) was investigated. G-CSF was administered subcutaneously to BALB/c mice inoculated with Meth-A cells at a dose of 2.5 micrograms/day for 5 consecutive days. When TNF (1 x 10(3) U) was administered intravenously to mice which had been pretreated with G-CSF, tumor growth showed a 74.1% inhibition 17 days after the tumor cell inoculation, compared to that of untreated mice. In this experiment, G-CSF significantly (P < 0.025) enhanced the antitumor effect of TNF. The in vitro cytotoxicity of TNF (10 U/ml) towards Meth-A cells was increased about 5.2-fold in the presence of neutrophils (E/T = 50) as compared to the cytotoxicity obtained with TNF alone. A combination of TNF and G-CSF (50 ng/ml) in the presence of neutrophils, resulted in a 2.1 times greater cytotoxicity against Meth-A cells as compared to that obtained without G-CSF. Significant augmenting effects of G-CSF on superoxide (O2-) production by TNF-stimulated neutrophils were observed. These observation suggest that the neutrophil plays an important role in the antitumor action of TNF on Meth-A cells, and that the antitumor effect of TNF is enhanced by combination with G-CSF.

Animals↗
PubMed1993

Prevalence of Raynaud's phenomenon and specific clinical signs related to progressive systemic sclerosis in the general population of Japan.

BACKGROUND: In order to evaluate the prevalence rates of Raynaud's phenomenon (RP) and specific clinical signs related to progressive systemic sclerosis (PSS) in the general population of Japan, inquiries were made concerning RP in the hands and dermatologic examinations were also conducted. METHODS: One thousand and sixty-three subjects (332 men and 731 women) over 30 years of age who underwent inhabitants' health examinations in 1990 were considered for this study. RESULTS: The prevalence of RP was 3.0% in men and 3.4% in women. In 8 men and 17 women with RP who received the blood tests, the positive rates of antinuclear antibody (ANA) were 12.5% and 35.3% in men and women, respectively. The prevalence rates of all five specific clinical signs related to PSS, sclerodactyly, pitting scars of the fingers, brown pigmentation of the body, shortened frenulum of the tongue, and flexion contracture of fingers, were under 2% in men and 3% in women. In women with RP the prevalence rates of sclerodactyly, pitting scars of the fingertips, brown pigmentation of the body, and shortened frenulum of the tongue were 16.0, 4.0, 4.0, and 16.0%, respectively. These values were significantly higher than those of persons without RP. CONCLUSIONS: Because some persons with primary RP may become typical cases of PSS within several years, a followup study, particularly for women who have positive titers of ANA with RP, should be carried out to find out whether the persons suffer from PSS or not.

Adult↗
PubMed1993

Malignant nerve sheath tumor with rhabdomyoblastic differentiation arising from the acoustic nerve.

A case of a malignant nerve sheath tumor with rhabdomyoblastic differentiation arising from the acoustic nerve in a 38 year old man is reported. At autopsy, the tumor was found to be extensively involved in the right cerebellopontine angle of the brain stem. Histologically, the tumor was composed mainly of spindle-shaped tumor cells proliferating in hypercellular fascicles scattered with pleomorphic cells. The tumor cells were characterized by high mitotic activity and invasive growth. Occasional tumor cells had eosinophilic cytoplasm, which in a few cases was cross-striated. Cytoplasmic interdigitations and a thick basal lamina were confirmed ultrastructurally. Immunohistochemical analysis revealed that some tumor cells were positive for myoglobin and desmin, but weakly positive or negative for S-100 protein. The patient did not have von Recklinghausen's disease.

Adult↗
PubMed1993

A study of prognosis in 52 cases with juvenile rheumatoid arthritis.

The prognosis in 52 patients with juvenile rheumatoid arthritis (JRA) was studied. There were 35 cases of systemic onset, 12 of polyarticular onset and 5 of pauciarticular onset. Thirteen systemic cases developed a polycyclic course with chronic polyarthritis. Many monocyclic JRA in systemic cases subsided within 1 year. There were no instances of polyarticular cases or pauciarticular cases that shifted to other type. However, there were many cases with a long active polyarticular JRA and with remission at an early stage in the pauciarticular type. The stage and class were I or II in 90% of cases with a good prognosis for the joints, but there were some serious cases. Transient carditis or iritis which developed at an early stage subsided later. The intractable systemic cases had drug-induced complications. The cases with steroid-induced complications tended to be chronic. One death in a systemic case was caused by hepatic failure.

Adolescent↗
PubMed1993

An analysis of the relationship between high-pass resolution perimetry and neuroretinal rim area in normal-tension glaucoma.

We evaluated the reproducibility of measurements of the visual function index, 'functional channels', of high-pass resolution perimetry and the correlation between functional channels and topographic changes of the optic nerve head, particularly on the neuroretinal rim area. The median coefficient of variation for the six intra-individual measurements of functional channels with high-pass resolution perimetry was 9.5%. In 26 eyes of 18 normal-tension glaucoma patients, functional channels showed statistically significant correlation with the neuroretinal rim area (rim area) of the optic disc measured by a Rodenstock Optic Nerve Head Analyzer. These results suggested that functional channels of high-pass resolution perimetry may be a useful new parameter for evaluating visual function of glaucoma patients.

Adult↗
PubMed1993

Incomplete interlobar fissures: bronchovascular analysis with CT.

Thin-section computed tomographic scans of both lungs in 154 patients, including seven cadavers, with lung cancer (n = 37), diffuse (n = 32) or inflammatory (n = 30) lung disease, other proved or suspected disease (n = 23), or healthy lungs (n = 32) were analyzed to determine the frequency of incomplete interlobar fissure (IIF). An IIF was defined as a discontinuous linear shadow that remained in contact with the chest wall. An IIF was found in 128 of 154 right lungs (83.1%) and 77 of 154 left lungs (50.0%). Some bronchovascular structures crossed or passed through two contiguous lobes in the fused area. The most common bronchovascular structure associated with an IIF was a pulmonary vein; this association was found in 87 right lungs (56.5%) and 20 left lungs (13.0%). An IIF was traversed by a pulmonary artery in only seven right lungs and 13 left lungs or by a bronchus in only three lungs. It is concluded that recognition of an IIF might improve understanding of the spread of pulmonary disease.

Bronchi↗
PubMed1993

Acute stroke in cats: comparison of dynamic susceptibility-contrast MR imaging with T2- and diffusion-weighted MR imaging.

PURPOSE: To evaluate the hemodynamics of acute stroke in cats by means of dynamic susceptibility-contrast magnetic resonance (MR) imaging compared with standard T2- and diffusion-weighted MR imaging. MATERIALS AND METHODS: Unilateral permanent occlusion of the middle cerebral artery was performed in 18 cats. MR imaging was performed with each method 2 hours (n = 2), 6 hours (n = 10), and 24 hours (n = 11) after occlusion. RESULTS: At every time point, dynamic MR images clearly showed ischemic regions of steady-state signal hyperintensity and areas of less dynamic decrease in signal intensity that corresponded closely to those seen on diffusion-weighted MR images. T2-weighted MR images did not reveal regions of high signal intensity 2 hours after occlusion. The measurements of relative blood volume obtained with the dynamic method were significantly lower in steady-state hyperintense ischemic areas of the affected side than those in the contralateral normal areas at 6 and 24 hours (P < .001). CONCLUSION: This dynamic method can advance the time of detection of early ischemia in comparison with T2-weighted MR imaging and provides functional information about hemodynamics not provided by other methods of MR imaging.

Acute Disease↗
PubMed1993

Tumor vascularity in the brain: evaluation with dynamic susceptibility-contrast MR imaging.

PURPOSE: To evaluate the efficacy of dynamic susceptibility-contrast magnetic resonance (MR) imaging for diagnosis of intraaxial brain tumors. MATERIALS AND METHODS: Ten patients with such tumors (two hemangioblastomas, five low-grade astrocytomas, and three glioblastomas) underwent examination at 1.5 T. After bolus injection of 0.15 mmol/kg gadopentetate dimeglumine, gradient-echo MR images were obtained every 3.6 seconds for 90 seconds. Region-of-interest analyses were performed in all tumors. RESULTS: The greatest loss in signal intensity during the first pass of the contrast agent was seen in hemangioblastomas; low-grade astrocytomas had the least loss. The differences in integration of change in the T2* relaxation rate were significant among the three types of tumor (hemangioblastomas vs low-grade astrocytomas, P < .001; hemangioblastomas vs glioblastomas, P < .005; and glioblastomas vs low-grade astrocytomas, P < .02) and indicated differences in vascularity. CONCLUSION: Dynamic susceptibility-contrast MR imaging can provide useful hemodynamic information about intraaxial brain tumors that is not provided by standard MR imaging and therefore contributes to the differential diagnosis.

Adolescent↗
PubMed1993

Pitting scars in progressive systemic sclerosis.

The digital pitting scar is a common clinical feature in patients with progressive systemic sclerosis (PSS). Its pathogenesis is unclear, but it may result in small ulcerations. The clinical and histological features of these lesions are poorly understood. Eighty-seven patients with PSS were examined at least once per year. Pitting scars were defined as pinhole-sized digital concave depressions with hyperkeratosis. They were seen in 34 cases (39%) and were located not only on the tips of the fingers, but also on the sides, especially on the radial border of the index and middle finger and the ulnar side of the thumb, where they had a linear arrangement. Additional pitting scars were noticed on the dorsal surface of the proximal interphalangeal and metacarpophalangeal joints. Pitting was closely associated with several signs of PSS, e.g. Raynaud's phenomenon, skin thickening or articular involvement (e.g. stiffness, swelling, pain). There was no relationship between the number of pitting scars and the duration of PSS. Biopsy samples were taken of the lesions on the lateral sides of fingers in 3 patients. Histologically, there was a plug-like hyperkeratosis with parakeratosis, homogenized collagen fibers and slight perivascular mononuclear cell infiltration. Calcification and altered collagen fibers were observed in the deep dermis. Although pitting scars of the fingertips may be different from those of the lateral sides of the fingers, both histologically and pathogenetically, they were similar clinically. The scar locations on the fingertips and finger joints (proximal interphalangeal and metacarpophalangeal) suggest that exogenous trauma, vibration injury and/or cold exposure may play a role in their pathogenesis.

Adult↗
PubMed1993

Parasympathetic cerebrovasodilator center of the facial nerve.

Functional studies have yet to be undertaken to establish which brain region subserves the parasympathetic regulation of the cerebral circulation. Using 31 anesthetized rats with precluded cervical sympathetic trunks, we therefore attempted to perform chemical stimulation of the greater petrosal nerve (GPN) cell group, which is a subgroup of the superior salivatory nucleus and sends off axons largely to the parasympathetic pterygopalatine ganglion via the GPN component of the facial nerve. The cerebrocortical blood flow was monitored with a laser-Doppler flowmeter. Unilateral stimulation of the GPN cell group by microinjection of L-glutamate reduced the ipsilateral cerebrocortical vascular resistance, maximally by 16.4 +/- 4.1% (mean +/- SD, n = 61). The response was not mediated by the classic muscarinic receptors of the cerebral vessel wall. However, pharmacological blockade of the peripheral parasympathetic ganglia and acute and chronic bilateral removal of the parasympathetic postganglionic fibers originating in the pterygopalatine ganglion abolished the response. The present data thus provide functional evidence that the GPN cell group may constitute a parasympathetic cerebrovasodilator center.

Animals↗
PubMed1993

Immunohistochemical studies on small intestinal mucosa in Kawasaki disease.

To investigate the etiology of Kawasaki disease (KD), the cell surface phenotypes of mononuclear cells and enterocytes in the jejunal mucosa of KD were investigated in a case-control study. Sixteen Japanese patients with KD were enrolled in the study. As disease controls, jejunal tissues from 10 patients with diarrhea due to cow's milk protein intolerance were used. The numbers of cells stained by an immunofluorescent technique were counted and analyzed statistically by t test. Both HLA-DR+CD3+ and DR+CD4+ cells were significantly increased in the lamina propria of KD patients in the acute phase compared with numbers in controls and patients with cow's milk protein intolerance (p < or = 0.01). CD8+ cells were significantly reduced in both the epithelium and the lamina propria of KD patients in the acute phase in comparison with numbers in both controls (p < or = 0.05) and patients with cow's milk protein intolerance (p < or = 0.01). HLA-DR+ cells were significantly increased in both the enterocytes and the lamina propria of KD patients in the acute phase compared with numbers in controls (p < or = 0.01). These cell patterns returned to normal in the convalescent phase of KD. Differences between these cell patterns in KD patients with and without diarrhea were not significant, although these immunohistochemical features tended to be more marked in patients with diarrhea than in those who lacked diarrhea. These results are consistent with what one would expect to find if a delayed-type hypersensitivity reaction had occurred in the small intestinal mucosa of KD patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Antigens, CD↗
PubMed1993

A differentiation-related molecule on the cell surface of human granulosa cells.

We raised a monoclonal antibody (OG-1) specifically reactive to human ovarian granulosa cells. Indirect immunofluorescence staining of freshly isolated granulosa cells from preovulatory follicles showed the OG-1 antigen on the cell surface of granulosa cells. The antigen was purified from granulosa cells by immunoaffinity chromatography. Under reducing or nonreducing conditions, the sodium dodecyl sulfate-polyacrylamide gel electrophoresis profile of the purified antigen showed two specific protein bands, corresponding to mol wt of 125 and 145 kilodaltons. Immunohistologically, the OG-1 antigen on granulosa cells of primary follicles seemed to increase during follicular development. After ovulation, the antigen was detected on granulosa cells during corpus luteum formation. The antigen expression began to decrease on corpus luteum days 10-12 and disappeared on corpus luteum days 13-14. Luteal cells of pregnancy did not express the OG-1 antigen. Granulosa cells in atretic follicles expressed the OG-1 antigen. On the contrary, thecal or small luteal cells did not express it throughout the menstrual cycle. These results indicate that OG-1 antigen is a differentiation-related surface antigen of human granulosa cells.

Adult↗
PubMed1993

Apparent genetic difference between hypothyroid patients with blocking-type thyrotropin receptor antibody and those without, as shown by restriction fragment length polymorphism analyses of HLA-DP loci.

HLA types in Japanese patients with primary hypothyroidism were analyzed to see whether those with blocking-type TSH receptor antibody (TSH-R BAb M) differed genetically from those with idiopathic myxedema (IM). HLA typings of -A, -B, -C, -DR, and -DQ (73 antigens) were performed serologically, and those of -D and -DP (29 antigens) were analyzed by the restriction fragment length polymorphism method. Thirty patients were studied with TSH-R BAb M, and 28 with IM. The data were analyzed and compared with our previous results from 88 Graves' patients, 46 Hashimoto patients, and 186 control subjects. Overall, 192 patients with 4 autoimmune thyroid disorders showed a decrease in -Aw19 and an increase in -DQw4 (corrected P < 0.05) and significant associations of -Aw33, -Bw46, -Cw3, -DRw8, -DR9, and -DQw3. In TSH-R BAb M patients, increases in -B35, -Bw60, and -Dw8 and decreases in -DR4 and -DPw2 were seen, whereas IM patients showed increased -DPw2, -Bw61, and -Dw23. In comparisons between TSH-R BAb M and IM, the difference in -DPw2 was highly significant. HLA-B35 differed significantly in these 2 types of hypothyroidism. In conclusion, TSH-R BAb M patients have decreased frequency of -DPw2 and are genetically similar to Graves' disease, whereas IM patients are characterized by high frequency of -DPw2 and are genetically similar to Hashimoto's thyroiditis.

Adult↗
PubMed1993

Pathophysiology of brain swelling after acute experimental brain compression and decompression.

Global ischemia was created by controlled expansion of an epidural balloon for 25 minutes in Group A (six cats) and for 5 minutes in Group B (six cats). The alterations of intracranial pressure, arteriovenous oxygen content difference, cerebral metabolic rate of oxygen, cerebral blood flow, and electroencephalogram were observed until brain death or 24 hours' survival with normal intracranial pressure. The animals were then killed for brain histological examination. In four other cats, a 2% solution of Evans blue dye (4 mg/kg) was injected intravenously--immediately after deflation--resulting in 25 minutes of global ischemia. Two other cats received 5 minutes of global ischemia. The cats were killed 1 hour later. Abrupt swelling occurred in Group A, and no swelling was found in Group B. A transient absolute hyperemia was found immediately after deflation in both groups. The cerebral blood flow and cerebral metabolic rate of oxygen decreased markedly with low arteriovenous oxygen content difference and flat electroencephalogram in Group A, compared with gradual recovery of cerebral blood flow and cerebral metabolic rate of oxygen with high arteriovenous oxygen content difference and reappearance of electroencephalogram activity in Group B. The extravasation of Evans blue was observed on the compressed cerebral hemisphere, thalamus, hypothalamus, and brain stem in swelling animals and only on the compressed hemisphere in nonswelling animals. Histologically, the damage and congestive dilation of capillary, degeneration, and necrosis of neuronal and glial cell were found prominently on the hypothalamus and brain stem in the swelling group.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1993

Amino acids and peptides. XIX. Preparation of enkephalin-poly(ethylene glycol) hybrid and evaluation of its analgesic activity.

The poly(ethylene glycol) hybrid of Leu-enkephalin (Tyr-Gly-Gly-Phe-Leu) was prepared and its analgesic activity was examined. Poly(ethylene glycol) #4000 was converted to amino-poly(ethylene glycol) and coupled with the N alpha-protected pentapeptide, followed by trifluoroacetic acid treatment to give the hybrid. The hybrid was soluble in water or various organic solvents. The analgesic activity of Leu-enkephalin was markedly potentiated by hybrid formation with poly(ethylene glycol).

Amino Acid Sequence↗
PubMed1993

New fluorinated dopamine D2 ligands with benzofuran skeleton. The synthesis and in vitro evaluation.

New fluorinated ligands with N-[(1-ethyl-2-pyrrolidinyl)methyl]-2,3-dihydrobenzofuran-7-carboxamide skeleton, which are useful as a prototype to develop 18F labelled in vivo radiotracer for positron emission tomography (PET), were synthesized, and their binding affinities for the dopamine D2 receptors were investigated. Fluorine atom was introduced at C-4 of the pyrrolidine ring (10) or at ethyl substituent at C-5 of the dihydrobenzofuran moiety (20). The in vitro IC50 values of these ligands for the dopamine D2 receptors which were determined by their ability to inhibit the binding of [3H]spiperone binding in rat striatal membrane were 17 and 36 nM, respectively. Thus, the fluorinated compounds 10 and 20 may be possible candidates for further in vivo investigation.

Animals↗