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Biomedical subjects

M Iwata

Publications and source records attributed to M Iwata.

At least 217 records · Page 12Linked to original sources
PubMed1997

Marinesco-Sjögren syndrome associated with acute myeloblastic leukemia.

Marinesco-Sjögren syndrome is a rare autosomal recessive disorder characterized by cerebellar atrophy, ataxia, cataracts, short stature and varying degrees of mental retardation. A high incidence of malignant disease associated with this syndrome has not so far been reported. We report the case of a 6-year-old girl affected with Marinesco-Sjögren syndrome, who developed acute myeloblastic leukemia (AML, M2), and whose karyotype was 46,XX,t(8;21),(q22;q22) in bone marrow blasts. This is the first report of Marinesco-Sjögren syndrome associated with malignant disorders.

Brain↗
PubMed1997

A study of bronchus-associated lymphoid tissue in a rat model of chronic pulmonary infection with Pseudomonas aeruginosa.

The immunologic pathogenesis of conditions characterized by chronic pulmonary infections, such as diffuse panbronchiolitis and those associated with cystic fibrosis, had not been fully clarified. Organized lymphoid tissue along the airway has been termed bronchus-associated lymphoid tissue (BALT), and hyperplasia of BALT is frequently observed in chronic pulmonary infections in humans. To investigate the role of BALT, we intratracheally inoculated rats with Pseudomonas aeruginosa (PA) enmeshed in agar beads according to the method of Cash et al., thereby establishing a chronic pulmonary infection model. Histopathological examination of tissue from this rat model revealed the accumulation of lymphocytes and foamy cells around bronchioles. This finding corresponds to chronic bronchiolitis in humans. Hyperplasia of BALT was also observed. Immunohistochemical examination demonstrated that Ia+ cells, helper T cells, surface IgM-positive (sIgM+) cells and sIgA+ cells had gradually increased in BALT and the walls of peripheral airways during the period from day 4 to 7. The anti-PA IgA antibody titer in bronchoalveolar lavage fluid (BALF) was also elevated during this period. After day 21, non-helper T cells became predominant in tissue sections, and the numbers of various immunoglobulin-positive cells as well as the anti-PA IgA antibody titer in BALF were reduced. Histological examination revealed that the inflammatory findings had also diminished. The time course of changes in the various immune cells in BALT and the walls of peripheral airways, paralleled the reductions in anti-PA IgA antibody titers in BALF. Our findings suggest that hyperplastic BALT may be one source of the Ig producing cells which play an important role in the local immune response characteristic of chronic pulmonary infections.

Animals↗
PubMed1997

[Prophylactic effect of black tea extract as gargle against influenza].

We examined whether gargling with black tea prevents influenza infection. Tests were carried out during a five month period (October 1992 to March 1993). The control group that followed their normal daily routine, whereas the test group that gargled with 0.5 w/v% black tea extract twice daily (at 8 a.m. and 5 p.m.). Influenza viruses were isolated from influenza patients and an antigen analysis was carried out. As a result, two strains of influenza A viruses (H3N2) and ten strains of B virus were detected. An HI test was done using paired sera of the control group and the test group. The HI titers raised a four fold or greater in 48.8% (61/125) in the control group and 35.1% (35/134) in the test group. There was a significant difference (p < 0.05) between the control and test groups. These results indicate that black tea extract is effective as a prophylactic agent against influenza infection.

Humans↗
PubMed1997

In vitro and in vivo antibacterial activities of CS-834, a novel oral carbapenem.

CS-834 is a novel oral carbapenem antibiotic. This compound is an ester-type prodrug of the active metabolite R-95867. The antibacterial activity of R-95867 was tested against 1,323 clinical isolates of 35 species and was compared with those of oral cephems, i.e., cefteram, cefpodoxime, cefdinir, and cefditoren, and that of a parenteral carbapenem, imipenem. R-95867 exhibited a broad spectrum of activity covering both gram-positive and -negative aerobes and anaerobes. Its activity was superior to those of the other compounds tested against most of the bacterial species tested. R-95867 showed potent antibacterial activity against clinically significant pathogens: methicillin-susceptible Staphylococcus aureus including ofloxacin-resistant strains, Streptococcus pneumoniae including penicillin-resistant strains, Clostridium perfringens, Neisseria spp., Moraxella catarrhalis, most members of the family Enterobacteriaceae, and Haemophilus influenzae (MIC at which 90% of strains are inhibited, < or =0.006 to 0.78 microg/ml). R-95867 was quite stable to hydrolysis by most of the beta-lactamases tested except the metallo-beta-lactamases from Stenotrophomonas maltophilia and Bacteroides fragilis. R-95867 showed potent bactericidal activity against S. aureus and Escherichia coli. Penicillin-binding proteins 1 and 4 of S. aureus and 1Bs, 2, 3, and 4 of E. coli had high affinities for R-95867. The in vivo efficacy of CS-834 was evaluated in murine systemic infections caused by 16 strains of gram-positive and -negative pathogens. The efficacy of CS-834 was in many cases superior to those of cefteram pivoxil, cefpodoxime proxetil, cefdinir, and cefditoren pivoxil, especially against infections caused by S. aureus, penicillin-resistant S. pneumoniae, E. coli, Citrobacter freundii, and Proteus vulgaris. Among the drugs tested, CS-834 showed the highest efficacy against experimental pneumonia in mice caused by penicillin-resistant S. pneumoniae.

Administration, Oral↗
PubMed1997

Responses of monkeys with pollinosis to two major allergens of Japanese cedar pollen.

We examined the responses of two Japanese monkeys with pollinosis to two major allergens (Cry j 1 and Cry j 2) of Japanese cedar pollen. The two monkeys (A and B) had specific IgE antibodies to the allergens and showed a strong positive reaction to both of them in the intradermal test. In the histamine release test with peripheral blood mononuclear cells (PBMC), monkey A showed a typical pattern similar to that seen in human patients, while monkey B released a low level of histamine. The proliferative response of PBMC to both allergens in monkey A was weak, but was typical in monkey B. From clinical as well as immunological points of view, these monkeys may be a suitable animal model for Japanese cedar pollinosis in humans.

Allergens↗
PubMed1997

[Trial for transdermal administration of sulfonylureas].

Sulfonylureas are widely used as oral hypoglycemic drugs in the treatment of non insulin dependent diabetes mellitus (NIDDM). Since sulfonylureas are usually taken for a long period, the compliance of the patients is very important. Therefore, for the improvement of the compliance of the patients, the development of a transdermal dosage form of sulfonylureas was attempted in this study. Glibenclamide (GLI) or chlorpropamide (CHL) was chosen as a principal agent and ointments were prepared by mixing 5% of GLI or CHL with a FAPG ointment base. Penetration and shearing stresses of the ointments were determined as physical characteristics of the ointments. There was no obvious difference of characteristics between the GLI ointment, or the CHL ointment and the FAPG ointment base. In drug release tests, the CHL ointment showed better release of the drug than the GLI ointment. In both ointments, comparatively rapid release of drug was observed in the initial 1 h, and continuous slow release was observed thereafter. When the ointments were applied on the back of male Wistar rats and the plasma glucose level was measured, both CHL and GLI ointments gave lower blood glucose levels than the control (FAPG base). At the all measuring points, the GLI ointment brought about significantly lower blood glucose levels than the control (p < 0.01). Thus, it was demonstrated that sulfonylureas were absorbed through the skin and lowered the blood glucose levels. The results suggest the possibility of transdermal administration of sulfonylureas for the treatment of NIDDM.

Animals↗
PubMed1997

[Sustained release double-layered progesterone suppository for luteal support therapy].

A sustained release suppository containing progesterone with a double-layered structure was prepared for the treatment of the luteal phase defect. Hydroxypropylcellulose-H (HPC) and Carbopol-934P (CP) were used as bases of the inner layer and Witepsol W35 was used as a base of the outer layer. The strength of the inner layer (stick) decreased with the increase of the rate of content of HPC component. The strength of the stick which was prepared from a mixture of HPC and CP in a ratio of 1:1, was inverse by proportional to the rate of the addition of crystalline cellulose (CC) and the amount of released drug was proportional to the rate of the addition of CC. The area under the drug release curve of the stick containing 60% of CC in the base was about 12 times of the stick containing no CC (control stick). Furthermore, the mean release time of the stick containing 60% of CC became about a half of the control stick. It was suggested that the drug release of progesterone from the stick could be controlled by changing the rate of the addition of CC. Two types of suppository which containing progesterone in both phases (suppository A) and in the stick alone (suppository B) were prepared. Both suppositories showed a sustained release property and suppository B had a lag time of two hours. When the suppositories were administered in to the vagina of rabbits, they showed a sustained release property and a rapid rise in the serum concentration was more suppressed than an ordinary Witepsol suppository. One hour after the administration of the two layered suppository, some parts of the suppository was identified macroscopically to be remained in the vagina. The usefulness of the double-layered suppository as a hospital preparation should be suggested after the attainment of the optimization of the formulation.

Acrylic Resins↗
PubMed1997

An adult case of Cockayne syndrome without sclerotic angiopathy.

We report an autopsy case of Cockayne syndrome (CS). A 40-year-old Japanese woman was admitted to our hospital for cachexia. She had displayed the striking features of CS, including dwarfism, mental retardation, neural deafness, ataxia, intracranial calcifications, and progeria since her childhood. Endocrinological examinations suggested normal pituitary function and a disorder of the hypothalamus or the cerebrum. She died of acute pneumonia at the age of 42. Autopsy findings showed typical abnormalities in the central nervous system compatible with CS; however, no atherosclerotic change was observed in the systemic arteries.

Adult↗
PubMed1997

Inorganic fluoride. Divergent effects on human proximal tubular cell viability.

Fluoride (F) is a widely distributed nephrotoxin with exposure potentially resulting from environmental pollution and from fluorinated anesthetic use (eg, isoflurane). This study sought to characterize some of the subcellular determinants of fluoride cytotoxicity and to determine whether subtoxic F exposure affects tubular cell vulnerability to superimposed ATP depletion and nephrotoxic attack. Human proximal tubular cells (HK-2) were cultured with differing amounts of NaF (0 to 20 mmol/L, overlapping with clinically relevant intrarenal/urinary levels after fluorinated anesthetic use). After completing 24-hour exposures, cell injury was determined (vital dye uptake). Fluoride effects on cell deacylation ([3]H-C20:4 release) and PLA2 activity were also assessed. To determine whether subtoxic F exposure alters tubular cell susceptibility to superimposed injury, cells were exposed to subtoxic NaF doses for 0 to 24 hours and then challenged with simulated ischemia (ATP depletion plus Ca2+ overload) or a clinically relevant nephrotoxic insult (myoglobin exposure). NaF induced dose-dependent cytotoxicity (up to approximately 90% vital dye uptake and increased [3H]C20:4 release). Extracellular Ca2+ chelation (EGTA) and PLA2 inhibitor therapy (aristolochic acid, dibucaine, or mepacrine) each conferred significant protective effects. When subtoxic NaF doses were applied, partial cytosolic PLA2 depletion rapidly developed (approximately 85% within 3 hours, determined on cell extracts). These partially PLA2-depleted cells were markedly resistant to ATP depletion/Ca2+ ionophore injury and to myoglobin-induced attack (approximately 50% decrease in cell death). We conclude that 1) F induces dose-dependent cytotoxicity in cultured human proximal tubular cells, 2) this occurs, in part, via Ca(2+)- and PLA2-dependent mechanism(s), 3) partial cytosolic PLA2 depletion subsequently results, and 4) subtoxic fluoride exposure can acutely increase cell resistance to further attack. Reductions in cytosolic PLA2 activity could potentially contribute to this result.

Adenosine Triphosphate↗
PubMed1997

[Accuracy of three-step diagnosis in discriminating subtypes of acute ischemic stroke].

The aim of this study is to evaluate the accuracy of three-step diagnosis in discriminating subtypes of acute ischemic stroke. A total of 120 consecutive patients with first-ever ischemic stroke, admitted to one general hospital, were prospectively studied. In the first step (within 24 hours of clinical onset), the first diagnosis was made according to clinical symptoms and signs, and patients were subdivided into four groups according to the classification of Oxfordshire Community Stroke Project: lacunar infarcts (LACI), total anterior circulation infarcts (TACI), partial anterior circulation infarcts (PACI), and posterior circulation infarcts (POCI). In the second step (24 hours to 72 hours from the onset), neuroimaging diagnosis was performed by CT and/or MRI. Four lesion sites were classified: 1) small subcortical infarction < or = 1.5 cm in diameter in the perforating artery territory (SSI), 2) supratentorial cortical or striatocapsular infarction (CI), 3) low-flow infarction (LFI) which includes centrum semiovale infarct and internal junctional infarct, and 4) posterior circulation infarction other than SSI (PI). In the third step, etiological diagnosis was made by examination including trans-thoracic echocardiography and MRA (3-D, PC). In accordance with the TOAST Study, the presumed stroke mechanism was categorized as either small-vessel occlusion (lacune), cardioembolism (CE), large-artery atherosclerosis (LAA), or others. The majority of patients with TACI, PACI or POCI showed the corresponding lesions on CT or MRI, while only 69% of LACI patients demonstrated SSI. Seventy-five percent of patients with TACI were categorized as CE in the third diagnosis, while the etiology of the patients with PACI was either CE or LAA in equal numbers. Only 60% of LACI patients were classified as lacune and 21% of them as LAA. Patients with LACI but classified as LAA usually had atypical clinical symptoms (e.g. monoparesis) and lesions other than SSI. The positive predictive value (PPV) of lacune in the combination of LACI and SSI was 0.75. Eighty-two percent of patients with CE had atrial fibrillation (af), which was the most frequent cardioembolic source. When patients with TACI or PACI had af, the PPV of CE was 0.93, but when they did not, the PPV of LAA was only 0.68. The etiology of POCI was variable. In conclusion, the agreement of the three-step diagnosis is considerable, but more rigorous clinical examination is needed for some clinical groups (POCI and LACI) and the etiological diagnosis of LAA.

Adult↗
PubMed1997

[Clinicopathological features of interstitial pneumonia associated with amyopathic dermatomyositis].

We studied clinicopathological characteristics of interstitial pneumonia associated with amyopathic dermatomyositis. The subjects comprised two men and three women, and their mean age was 58.2 years. All subjects had cruptions specific for dermatomyositis, but had no signs of myositis. They all presented with acutely or subacutely developed coughing and dyspnea. Results of tests for anti-Jo-1 antibody were negative in all cases. Chest X-ray films showed infiltrations or streaky shadows, or both in the middle and lower lung fields. Analysis of bronchoalveolar lavage fluid revealed abnormally high percentages of lymphocytes and neutrophils. In one patients a specimen obtained by open lung biopsy showed homogeneous cell infiltrations in alveolar septa and regional alveolar damage. That patient was successfully treated with cyclosporin and corticosteroids in early phase of the disease. The other four patients received immunosuppressive agents after respiratory failure developed. All four died despite having received high-dose corticosteroid and immunosuppressive therapy. Examination of autopsy specimens showed diffuse alveolar damage.

Acute Disease↗
PubMed1997

[A case of basilar artery occlusion associated with one-and-a-half syndrome, paralytic pontine exotropia and WEBINO-syndrome].

We report a 79-year-old woman with basilar artery occlusion. She had a sudden onset of tetraplegia and disturbed consciousness, and within four days from the onset she showed a varied, fluctuating eye symptoms. On admission, she showed ocular bobbing, skew deviation with the right eye lower-positioned, upward gaze palsy, one-and-a-half syndrome, and paralytic pontine exotropia (PPE). On the third day after the onset, she showed wall-eyed bilateral internuclear ophthalmoplegia (WEBINO) syndrome, and on the fourth day, she showed one-and-a-half syndrome again. Her right-gaze palsy improved repeatedly, and on the 19th day from the onset, only right MLF syndrome remained. Her eye symptoms fluctuated probably according to the distal migration of emboli, there by the responsible lesion and the mechanism of these eye symptoms are considered to be closely inter-correlated. On the fourth day after onset, the magnetic resonance imaging revealed cerebral infarctions in bilateral middle pons, the left paramedian lower pons, and the right paramedian midbrain, and a hemorrhagic infarction in the right inferior cerebellar hemisphere. We believe that that the eye symptoms of this patient were caused by lesions in the paramedian midbrain or pons.

Aged↗
PubMed1997

[Non-uremic neuropathy in hemodialysis patients].

We have reviewed 20 clinical records of hemodialysis patients with neuropathy admitted to the Department of Neurology during 1978 april through 1995 march. The clinical diagnosis was made based on clinical findings, neurophysiological examinations, and histopathological findings of sural nerve and peroneal muscle biopsies. Four out of twenty hemodialysis patients with neuropathy were non-uremic neuropathy. The diagnosis of neuropathy of four patients were chronic inflammatory demyelinating polyneuropathy, neuropathy with graft versus host disease, Guillain-Barré syndrome, and subacute combined degeneration of the spinal cord. All patients improved after the treatment. It is important to consider the possibility of association of non-uremic neuropathy in hemodialysis patients.

Adult↗
PubMed1997

[Three cases of thymic hyperplasia associated with hyperthyroidism].

We encountered three cases of thymic hyperplasia associated with hyperthyroidism. Case 1 was in a 35-year-old woman; a chest CT scan showed an anterior mediastinal mass and right-sided pleural effusion, which suggested the presence of a thymoma Case 2 was in a 21-year-old man who complained of palpebral ptosis and also had myasthenia gravis (Osserman type I). Case 3 was in a 47-year-old woman; a chest CT scan showed thymic hyperplasia and mediastinal lymphadenopathy. In all cases, anti-thyroid medication was given first, because of the associations with hyperthyroidism. Moreover, in cases 1 and 2 no tumor was found, and only hyperplasia was detected in the thymus, although both patients underwent extended thymectomy. Furthermore, surgery was not effective against the hyperthyroidism (anti-thyroid medication could not be withdrawn or reduced). In cases 2 and 3, thymic hyperplasia, as seen on chest CT scans, resolved as thyroid function was normalized by anti-thyroid medication. The pretracheal lymphadenopathy seen in case 3 also resolved. Thymic hyperplasia may have been a result, not a cause, of hyperthyroidism. When we encounter patients with thymic masses and hyperthyroidism, we should give anti-thyroid medication and observe the thymus for some time before resorting to surgery.

Adult↗