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Biomedical subjects

M Kanda

Publications and source records attributed to M Kanda.

At least 73 records · Page 4Linked to original sources
PubMed1998

Nodal T-cell lymphoma in an HTLV-I-endemic area: proviral HTLV-I DNA, histological classification and clinical evaluation.

Adult T-cell leukaemia/lymphoma (ATLL) is a human malignancy associated with human T-cell leukaemia virus type I (HTLV-I). The histology usually indicates a pleomorphic type, but is not consistent. To clarify the relationship between the histological classification and prognosis in ATLL, and to confirm the significance of clonal HTLV-I integration, we reclassified 572 cases with nodal T-cell lymphoma in which the T-cell phenotype and/or genotype was confirmed. In all cases the clonal integration of HTLV-I proviral DNA in the lymph nodes was examined by Southern blot analysis. In addition, anti-ATL antigen (ATLA) determination in the serum or PCR analysis of HTLV-I pX amplification in lymph nodes was also performed. 66/313 (21%) cases with ATLA had no evidence of clonal HTLV-I integration. 572 cases were classified into three groups: (A) cases with clonal integration (247 cases), (B) cases with ATLA without clonal integration of HTLV-I proviral DNA (66 cases), (C) cases without ATLA (259 cases). Histologically, groups B and C frequently demonstrated large cell type and angioimmunoblastic lymphadenopathy with dysproteinaemia (AILD) type; however, group A tended to show a pleomorphic type. Clinically, group A showed a poorer prognosis than groups B and C. In conclusion, group A cases were defined as ATLL (HTLV-I-associated T-cell lymphoma), whereas group B was classified as T-cell lymphoma, which had coincidently occurred in HTLV-I infected carriers. The simplified classification of REAL indicated clinical outcome: the prognosis of ATLL was poor, the unspecified type was intermediate, whereas the other types of lymphoblastic, AILD and anaplastic large cell type were all relatively favourable.

Blotting, Southern↗
PubMed1998

Perforin and Fas pathways of cytotoxic T-cells in histiocytic necrotizing lymphadenitis.

AIMS: Cell death can be divided into necrosis and apoptosis. In histiocytic necrotizing lymphadenitis (HNL), apoptosis is the main form of cell death. Two molecular mechanisms of T-cell-mediated cytotoxicity, one perforin-based and the other Fas-based, have been demonstrated, and both systems induce apoptosis of the target cells. This study was designed to investigate the Fas and perforin pathways in HNL. METHODS AND RESULTS: Twelve cases of HNL were analysed using immunohistochemical staining. The Fas and/or FasL-positive cells, including lymphocytes and histiocytes, were frequently encountered in the necrotizing lesions, however, they were rare in the nonpathological regions. The perforin and/or granzyme-positive cells were also confined in the necrotizing lesions. In double staining, CD8-positive lymphocytes occasionally expressed Fas and/or FasL, and histiocytes also expressed FasL and/or Fas. However, CD4-positive lymphocytes rarely expressed FasL and/or Fas. In a flow cytometric analysis, most of the cytotoxic T-cells, which were recognized by cytolytic granules of TIA-1 and considered to be CD8-positive lymphocytes, expressed FasL and Fas. The perforin-positive lymphocytes also expressed FasL and Fas. CONCLUSION: In our previous study, the apoptotic cells were T-cells, especially CD8-positive cells rather than CD4-positive cells. Based on these findings, in Fas and perforin pathways, the CD8-positive cells were considered to be effector and target cells, while histiocytes could possibly be enhancers. As a result, both pathways seemed to induce an abundance of apoptosis and thus induce necrotizing lesions.

Adolescent↗
PubMed1998

Protective Effects of Iganidipine on Morphological and Functional Changes of Arteries in Hypertensive Dahl Rats.

BACKGROUND: This study was performed to examine the protective effects of iganidipine, a new water-soluble calcium antagonist, on the morphological and functional changes of arteries in Dahl salt-sensitive (Dahl-S) rats. METHODS AND RESULTS: Vehicle and iganidipine were administered orally to Dahl-S rats fed a high-salt diet (HSD) for 8 weeks. Aorta, superior mesenteric arteries (SMA), and peripheral mesenteric arteries (PMA) were examined light-microscopically or electon-microscopically. Relaxant responses of isolated aorta and SMA were recorded isometrically. In rats fed HSD, blood pressure was markedly increased. Light microscopy showed intimal and medial hypertrophy, periarteritis, and narrowed arterial lumen in the PMA. Transmission and scanning electron microscopy or light microscopy showed medical thickness in the aorta and SMA and hypertrophy of endothelial cells and dilatation of the subendothelial space only in the aorta. In the SMA, both endothelium-dependent relaxation (EDR) and endothelium-independent relaxations (EIR) were reduced to a similar extent. In the aorta, the EDR was more markedly attenuated than the EIR. Iganidipine at 3 mg/kg/day showed a 24-h sustained hypotensive effect and completely prevented the morphological and functional changes in both arteries. Iganidipine at 1 mg/kg/day, which lowered blood pressure only for several hours, decreased the injuries in PMA and aortic endothelium and moderately restored the EDR in the aorta. Iganidipine at 0.3 mg/kg/day had no effects. CONCLUSIONS: In Dahl-S rats fed an HSD, iganidipine completely prevented all the changes at a sustained-hypotensive dose and prevented the injuries of PMA and aortic endothelium and the reduction of EDR in the aorta at a nonsustained hypotensive dose. Nonhemodynamic effects of iganidipine may be partly involved in its protective effects against arterial injuries.

Journal Article↗
PubMed1998

Development of in vitro fertilized feline embryos in a modified Earle's balanced salt solution: influence of protein supplements and culture dishes on fertilization success and blastocyst formation.

The effects of protein supplements and culture dish type on in vitro fertilization (IVF) and embryo development in culture were examined in the domestic cat. In Experiment I, follicular oocytes were fertilized and cultured in either 1) modified Earle's balanced salt solution, designated MK-1, supplemented with one of the following: 10% human serum (HS), 10% FCS or 0.4% BSA, or 2) Medium 199 (M-199) supplemented with 10% FCS. Fertilization rates were lower (P < 0.01) in MK-1 + BSA (74.4%), MK-1 + FCS (56.1%), and M-199 + FCS (51.4%) than in MK-1 + HS (94.7%). A greater (P < 0.01) percentage of blastocysts was obtained in MK-1 + HS (50.0%) than in other treatment groups (range, 4.3-17.2%). In Experiment II, the effect of dish type (tissue culture dish, TCD, versus suspension culture dish, SCD) on embryo development was evaluated in MK-1 supplemented with either HS or BSA. Significantly higher proportions of IVF-derived embryos developed to blastocysts at 120 and 144 hr post-insemination, respectively, when cultured in HS/SCD (47.2 and 71.7%) than in BSA/SCD (11.4 and 27.3%) or BSA/TCD (10.4 and 25.0%). At 120 hr post-insemination, there was a lower (P < 0.01) percentage of blastocysts in HS/TCD (22.2%) than in HS/SCD. In Experiment III, six embryos per cat were transferred to the uterine horns of 17 recipients at 144 hr after hCG treatment. Five of 7 recipients which received late morulae cultured in MK-1 + BSA (SCD) for 120 hr became pregnant (71.4%). Eight of 10 recipients which received early blastocysts cultured in MK-1 + HS (SCD) for 120 hr became pregnant (80.0%). We conclude that MK-1 containing HS is highly beneficial for overcoming the in vitro developmental block of IVF-derived feline embryos and increasing the success rate of IVF/ET.

Animals↗
PubMed1998

Intravascular large cell lymphoma associated with hypoalbuminemia.

We report here a 71-yr-old Japanese woman who presented with severe anasarca and hypoalbuminemia. She had a postmortem diagnosis of intravascular large B-cell lymphoma, which is a rare type of lymphoma characterized by an intravascular proliferation of lymphoma cells. Severe generalized edema was thought to be attributed to vascular and/or lymphatic obstruction due to proliferation of lymphoma cells within the lumina and/or an increase in catabolism induced by tumor proliferation.

Aged↗
PubMed1997

Positive evidence that anti-Toxoplasma gondii IgA antibody exists in the intestinal tract of infected cats and exerts protective activity against the infection.

The presence of anti-Toxoplasma gondii IgA antibody in the feces and intestinal tract of cats infected with this parasite was demonstrated using an immunoblotting assay. Cats (n = 5) were inoculated orally with T. gondii cysts and supernatants of feces and washings of the intestinal tract were assayed for secretory IgA specific for the parasite. The secretory IgA detected recognized tachyzoite antigens of m.w. 24, 34, 38 and 43 kDa and one sporozoite antigen of m.w. 24 kDa. No reactivity was shown against bradyzoites or enteroepithelial stage parasites. Tachyzoites preincubated with washings of the intestinal tract of infected cats showed decreased activity in penetration of feline fibroblast cells, as compared to tachyzoites preincubated with similar washings derived from non-infected cats. The addition of either anti-cat IgA or anti-cat IgG to the washings had no effect on the inhibitory activity which reduced the parasite's cell-penetration activity. However, the addition of both anti-cat IgA and anti-cat IgG to the washings diminished the inhibitory activity. These results suggest that anti-T. gondii antibodies of both classes, secretory IgA and IgG, exist in the intestinal tract of infected cats and these may be capable of preventing infection.

Animals↗
PubMed1997

Arginase of Bacillus brevis Nagano: purification, properties, and implication in gramicidin S biosynthesis.

An arginase [EC 3.5.3.1] was purified to homogeneous state from a gramicidin S-producing Bacillus brevis Nagano. The enzyme has a molecular weight of about 180,000 on gel filtration. The subunit molecular weight is 32,000 by sodium dodecyl sulfate polyacrylamide gel electrophoresis, indicating that the enzyme is hexameric. The optimum pH is found near 10.0. Mn2+ is essential for its activity and Fe2+, Co2+, Ni2+, and Mg2+ cannot replace Mn2+. The enzyme is highly specific for L-arginine with a K(m) value of 12.8 mM for L-arginine, which is similar to that of liver-type arginase in ureotelic animals. B. brevis arginase is apparently induced by the addition of L-arginine to the glutamate medium. The increased formation of L-ornithine, a constituent amino acid of gramicidin S, by arginase may be involved in the accelerated production of gramicidin S by B. brevis in the presence of L-arginine in the growth medium.

Arginase↗
PubMed1997

Functional localization of pain perception in the human brain studied by PET.

To elucidate the functional localization and somatotopic organization of pain perception in the human cerebral cortex, we studied the regional cerebral blood flow using positron emission tomography during selective painful stimulation in six normal subjects. Response to a painful stimulus was elicited using a special CO2 laser, which selectively activates nociceptive receptors, to the hand and foot. Multiple brain areas, including bilateral secondary somatosensory cortices (SII) and insula, and the frontal lobe and thalamus contralateral to the stimulus side, were found to be involved in the response to painful stimulation. While our data indicate that the bilateral SII play an important role in pain perception, they also indicate that there is no pain-related somatotopic organization in the human SII or insula.

Adult↗
PubMed1997

Isolation of coccidian enteroepithelial stages of Toxoplasma gondii from the intestinal mucosa of cats by Percoll density-gradient centrifugation.

A method for isolation of enteroepithelial stages of Toxoplasma gondii from the intestinal mucosa of experimentally infected cats was developed using Percoll density-gradient centrifugation. Gamonts and merozoites were obtained essentially free of host-cell debris. A recovery rate of nearly 30% of the parasites in the original preparations was obtained by this method. Merozoites were separated from gamonts by filtration through a 3-micron polycarbonate filter.

Animals↗
PubMed1997

Nasal T/NK cell lymphomas commonly express perforin and Fas ligand: important mediators of tissue damage.

AIMS: Two molecular mechanisms of T/natural killer (NK) cell-mediated cytotoxicity, one perforin based and the other Fas based, have been demonstrated, and both systems induce cytotoxicity in the target cells. The Fas-based mechanism involves the transducing molecule Fas and its ligand (FasL). In addition, perforin and/or FasL are also expressed in the cytotoxic T/NK cells. This study was thus designed to investigate the Fas and perforin pathways of the cytotoxic T/NK lymphoma cells in the nasal cavity. METHODS AND RESULTS: Eight patients with nasal lymphoma were analysed using immunohistochemical staining methods. Two cases were CD3+ CD56+ (T/NK cell) type, and six were CD3- CD56+ (NK cell) type. All cases showed Epstein-Barr virus genomes by in-situ hybridization. In addition, all cases showed the expression of TIA-1 (GMP-17), which is a marker of cytotoxic T and NK cells. FasL was expressed in the majority of the lymphoma cells and some histiocytes, while Fas was found in lymphoma cells and many non-neoplastic cells. In addition, the expression of perforin was detected in almost all lymphoma cells. In the double stainings, lymphoma cells expressed both FasL and perforin. Based on these findings, both the perforin- and Fas-based pathway of the cytotoxic T/NK lymphoma cells are thus considered to play an important role in the clinical features. CONCLUSIONS: Tissue damage is a common morphological feature in nasal T/NK cell lymphoma. The above findings therefore support the theory that tissue damage is due to both the cytotoxicity of T/NK lymphoma cells as well as to angiocentricity.

Adult↗
PubMed1997

[Tachykinin receptor subtypes involved in endothelium-dependent and -independent responses in rabbit intrapulmonary arteries].

In the present study, it was demonstrated that SP, neurokinin A (NKA), neurokinin B (NKB), SP methyl ester (SPME), [Ala5, beta-Ala8]-alpha-neurokinin fragment 4-10 (AANF) at 10(-8) M all caused contraction in non-contracted endothelium-intact arteries. SP- and SPME-induced contraction were reduced by removal of endothelium. All the peptides with the exception of AANF induced transient relaxation in the precontracted arteries. The relaxation were attenuated by removal of endothelium. The potency orders for endothelium-dependent contraction (EDC), -dependent relaxation (EDR) and -independent contraction (EIC) were SP > SPME >> NKA [symbol: see text] NKB [symbol: see text] AANF, SP > SPME > NKA > NKB >> AANF and NKA > AANF > NKB >> SP [symbol: see text] SPME, respectively. SP-induced EDC and EDR were attenuated by an NK1 antagonist but not by an NK2 antagonist. The SP-induced EIC was reduced by an NK2 antagonist. SP-induced EDC was attenuated by aspirin, OKY-046, and S-1452. The EDR was attenuated by L-NAME and methylene blue. The EDC induced by SPME was non-competitively attenuated by CP-99994, an NK1 antagonist. EDR was competitively inhibited by CP-99994. In conclusion, SP and related peptides caused EDC via NK1 receptors and TXA2 production, EDR via NK1 receptors and NO release and EIC via NK2 receptors in rabbit intrapulmonary arteries.

Animals↗
PubMed1997

Effects of ONO-2235, an aldose reductase inhibitor, on muscarinic receptors and contractile response of the urinary bladder in rats with streptozotocin-induced diabetes.

This study was conducted to evaluate effects of the aldose reductase inhibitor ONO-2235 on the contractile response to acetylcholine of the urinary bladder dome of streptozotocin-induced diabetes mellitus (DM) rats and simultaneously observe the changes in the function and number of muscarinic receptors and the sorbitol content of the bladder. The contractile response to acetylcholine increased 51% in the DM rat bladder dome compared to the normal rats; however, this was attenuated to a 10% increase by administration of 100 mg/kg ONO-2235 for 2 weeks. Treatment with ONO-2235 significantly decreased the specific [3H]quinuclidinyl benzilate binding in DM rats. However there was no significant dose-dependency among the ONO-2235-treated groups. The sorbitol levels of the sciatic nerve and the bladder were higher in the DM rats compared to the control rats; ONO-2235 decreased the level, although it did not completely reverse them to the control level. These results suggest that an aldose reductase inhibitor attenuates the increase of the muscarinic receptor number and normalizes the enhanced contractile response to acetylcholine caused by hyperglycemia and diuresis, probably through suppression of the polyol-pathway in the DM rat bladder dome.

Acetylcholine↗
PubMed1997

[Cleidocranial dysplasia: a case report].

A 3-month-old female infant who presented with patent sagittal suture and loss of weight is described. Physical examination revealed a large sagittal and metopic suture showing delayed closure, a high-arched palate, saddle nose, hypertelorism and nonpalpable edges of the bilateral clavicles. The clavicles also showed undue mobility. Radiological investigations of the cranial skeletal abnormalities revealed enlargement of the sagittal and metopic sutures, and the anterior and posterior fontanelles. A chest radiograph showed a small, bell-shaped thoracic rib cage with partial aplasia of both clavicles. On the basis of the clinical findings, cleidocranial dysplasia was diagnosed. Cleidocranial dysplasia is an uncommon generalized skeletal disorder which, as its name implies, shows striking involvement of the cranial vault and clavicles. The clinical features reflect a generalized defect of both membranous and endochondral bone formation. It is characterized by delayed ossification of the skull, aplastic or hypoplastic clavicles, delayed deciduous dentition, and hereditary characteristics. The amount of calvarial growth is generally small, and the shape remains nearly unaltered. In all cases, calvarial bone thickness increases with age, but in the midline, the fontanelle area, which is shown to be defective at the first examination, remains open in all cases. The midfrontal area is poorly developed and exhibits a groove in many patients. It is inherited as an autosomal dominant trait, with wide variability of expression but a high degree of penetrance. Cytogenetic abnormalities involving chromosome 6p21 have been reported with a cleidocranial dysplasia phenotype. Although psychosocial disorders associated with the abnormal facial and body features may occur, patients have a good overall prognosis and life expectancy. Skull deformity, and delayed closure of the fontanelles and cranial sutures are the most important problems for neurosurgeons. The postero-lateral fontanelle closes before adulthood, whereas the opening in the midfrontal sutural area may persist. Many children with cleidocranial dysplasia whom we have encountered have persisting fontanelles and patent sutures, but this does not seem to predispose them to an abnormal calvarial growth pattern, at least in the age groups investigated. Congenital midface retrusion in the presence of relative or absolute mandibular prognathism is also a major deformity. Care is supportive, including attention to neurosurgical, orthopedic, pediatric and dental problems.

Cleidocranial Dysplasia↗
PubMed1996

Toxoplasma gondii: experimental infection in cats vaccinated with 60Co-irradiated tachyzoites.

The effects of 60Co-irradiation on the viability and immunogenicity of RH and Beverley strains of Toxoplasma gondii was examined. While 60Co-irradiated tachyzoites retained invasive activity in mouse embryonal cells and sustained antigenicity in mouse peritoneal macrophages, the parasites did not develop in host cells. Vaccination of mice with 60Co-irradiated tachyzoites of either RH or Beverley strains induced resistance to challenge with a highly virulent strain (RH strain). Vaccination of kittens with 60Co-irradiated tachyzoites of the Beverley strain partially prevented oocyst shedding when challenged with cysts (bradyzoites) from the Beverley strain. But kittens vaccinated with 60Co-irradiated or fixed tachyzoites of the RH strain shed oocysts when challenged with cysts (bradyzoites) from the Beverley strain. These results suggest that the development of protective immunity in feline toxoplasmosis seems to be strain and/or stage-specific.

Animals↗
PubMed1996

Retrotransposons of rice involved in mutations induced by tissue culture.

Five retrotransposon families of rice (Tos1-Tos5) have been reported previously. Here we report 15 new retrotransposon families of rice (Tos6-Tos20). In contrast to yeast and Drosophila retrotransposons, all of the rice retrotransposons examined appear inactive (or almost inactive) under normal growth conditions. Three of the rice retrotransposons (Tos10, Tos17, and Tos19) are activated under tissue culture conditions. The most active one, Tos17, was studied in detail. The copy number of Tos17 increased with prolonged culture period. In all of the plants regenerated from tissue cultures, including transgenic plants, 5 to 30 transposed Tos17 copies were detected. The transcript of Tos17 was only detected under tissue culture conditions, indicating that the transposition of Tos17 is mainly regulated at the transcriptional level. To examine the target-site specificity of Tos17 transposition, sequences flanking transposed Tos17 copies were analyzed. At least four out of eight target sites examined are coding regions. Other target sites may also be in genes because two out of four were transcribed. The regenerated plants with Tos17-insertions in the phytochrome A gene and the S-receptor kinase-related gene were identified. These results indicate that activation of Tos17 is an important cause of tissue culture-induced mutations. Tissue culture-induced activation of Tos17 may be a useful tool for insertional mutagenesis and functional analysis of genes.

Amino Acid Sequence↗
PubMed1996

Pain-related and cognitive components of somatosensory evoked potentials following CO2 laser stimulation in man.

We recorded cortical potentials evoked by painful CO2 laser stimulation (pain SEP) employing an oddball paradigm in an effort to demonstrate event-related potentials (ERP) associated with pain. In 12 healthy subjects, frequent (standard) pain stimuli (probability 0.8) were delivered to one side of the dorsum of the left hand while rare (target) pain stimuli (probability 0.2) were delivered to the other side of the same hand. Subjects were instructed to perform either a mental count or button press in response to the target stimuli. Two early components (N2 and P2) of the pain SEP demonstrated a Cz maximal distribution, and showed no difference in latency, amplitude or scalp topography between the oddball conditions or between response tasks. In addition, another positive component (P3) following the P2 was recorded maximally at Pz only in response to the target stimuli with a peak latency of 593 msec for the count task and 560 msec for the button press task. Its scalp topography was the same as that for electric and auditory P3. The longer latency of pain P3 can be explained not only by its slower impulse conduction but also by the effects of task difficulty in the oddball paradigm employing the pain stimulus compared with electric and auditory stimulus paradigms. It is concluded that the P3 for the pain modality is mainly related to a cognitive process and corresponds to the P3 of electric and auditory evoked responses, whereas both N2 and P2 are mainly pain-related components.

Adult↗
PubMed1996

Pain-related somatosensory evoked potentials can quantitatively evaluate hypalgesia in Wallenberg's syndrome.

In 6 patients with Wallenberg's syndrome who showed a dissociated loss of pain sense, we recorded pain-related somatosensory evoked potentials following CO2 laser stimulation of the hand dorsum (pain SEPs). Two components, N2 and P2, were recorded by stimulation of the unaffected hand, whereas on the affected side they were absent or decreased in proportion to the severity of hypalgesia which was evaluated by both needle test and CO2 laser stimulation. Latency of either component, if appeared, was longer in the affected hand stimulation than that in the unaffected one. In contrast, N20 of the conventional electrically-stimulated SEPs (electric SEPs) showed no difference between the two sides. It is concluded that, unlike other electrophysiological methods, pain SEPs following CO2 laser stimulation can quantitatively evaluate functional impairment of the spinothalamic tract in Wallenberg's syndrome.

Adult↗