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Biomedical subjects

K Hamada

Publications and source records attributed to K Hamada.

At least 361 records · Page 20Linked to original sources
PubMed1992

Comparing the anticonvulsive effects of dapsone on amygdala-kindled seizures and hippocampal-kindled seizures in rats.

Dapsone, an antileprosy drug, was administered to rats with amygdala (AM)-kindled seizures or hippocampal (HIPP)-kindled seizures to elucidate its anticonvulsive efficacy. Adult male Wistar rats were subjected to kindling stimulations 2 weeks after electrode-implantation. The subjects were tested once a day for 7 successive days after inducing three generalized (stage 5) seizures to study the effects of dapsone. Dapsone had an inhibitory effect on stage 5 seizures at 12.50 mg/kg in the AM-kindled rats and at 6.25 mg/kg and 9.375 mg/kg in the HIPP-kindled rats. Thus, there was a distinct difference in the effective dose for generalized seizures between the AM-kindled rats and the HIPP-kindled rats. The inhibitory action of dapsone on stage 5 seizures may be due mainly to the elevation of the afterdischarge-triggering threshold at the stimulation site of the AM or HIPP. Such inhibitory action appears prominently at serum concentrations of about 13 micrograms/ml in AM-kindled rats and about 6 micrograms/ml in HIPP-kindled rats. The level of 6 micrograms/ml almost equals the therapeutic serum concentration of dapsone used in the treatment of leprosy.

Amygdala↗
PubMed1992

[Long-term chemotherapy using erythromycin (EM) for chronic lower airway infection: effectiveness of clarithromycin in EM ineffective cases--the fourth report].

The effectiveness of long-term chemotherapy using Erythromycin (EM) for chronic lower airway infection has been practically proved. However, there still exist some ineffective cases, or cases in which the clinical effect was scarcely seen. In the present study was administered Clarithromycin (CAM) to such cases and found that CAM was effective in alleviating symptoms in some of them. The results were presented along with clinical findings and other basic studies. The subjects were 4 cases in which EM was either ineffective or low in its clinical effect. The subjects consisted of 1 case of DPB and 3 cases of bronchiectasis. EM was clinically ineffective in 2 cases and slightly effective in the two others. The pathogen was Pseudomonas aeruginosa in all cases. The dosage of EM was 200-1200 mg/day. The period of administration ranged from 2 years to 6 years 9 months. CAM was given orally after meals at a dose of either 200 or 400 mg/day. Chemotherapy had continued for 3-8 months at the time of final observation (Feb. 1992). Clinical effectiveness was evaluated on the basis of sputum volume and PaO2 examination, as well as evaluation by the patients themselves. As a result, in all 4 cases, reduction in sputum volume and improvement of PaO2 were observed. All subjects evaluated CAM therapy as being more effective than EM therapy. Moreover, it was found that CAM inhibited both the elastase and leucocidin produced in one of the ineffective cases by P. aeruginosa, whereas EM didnt.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

[The 5th report on long-term chemotherapy using erythromycin (EM) for chronic lower airway infection--cases followed over 7 years].

Clinical studies were made over 7 years on 9 cases to whom long-term chemotherapy with EM was administered for chronic airway infection. 1) Clinical effectiveness: Highly effective in 8 cases; Improvement in QOL was observed in 8 cases. Bacteriological effect: In 7 cases, pathogenic bacteria disappeared. 2) No side effects were observed. 3) Changes in PaO2 levels with the passage of time: In most cases, PaO2 reached a plateau within 1 year. Although in some cases, there was subsequent elevation. 4) The frequency of catching cold over the 7 years period was low with an average of 1.2 times/year per subject. In only 2 cases were subject hospitalized due to acute exacerbation triggered by a cold. 5) Mucociliary transport improved in 7 out of 8 cases examined. However, only 4 of these recovered normal transport. The effect of EM in the other cases in which clinical improvement was not demonstrated was deemed slightly effective. On the basis of the above findings, it was suggested that long-term chemotherapy using EM was clinically efficacious. This is based on the fact that its efficacy, including amelioration of QOL appeared within one year of the initiation of therapy, and continued without decline for over 7 years.

Administration, Oral↗
PubMed1992

[A clinical study of respiratory tract infection due to Staphylococcus aureus detected by transtracheal aspiration].

A clinical study of 24 patients with respiratory tract infection due to S. aureus detected by transtracheal aspiration (TTA) was conducted, and the following results were obtained. 1) The detection frequency of S. aureus was relatively low (4.6%). 2) Pneumonia was the principal clinical manifestation. 3) Approximately one half of the patients had previously received antimicrobials. 4) Multiple organisms were frequently detected, particularly in cases of hospital-acquired infection. H. influenzae was the most frequently simultaneously detected organism. 5) On sputum examination, approximately 20 ml of purulent sputum was found in most cases, and S. aureus was detected in sputum specimens from 20 of the patients. 6) The largest number of cases was found in 1987. Onset was most common from autumn to spring. 7) Undernutrition was the most frequently associated host factor. As indicated by the above findings, the clinical expression of S. aureus infection is variable, and it is important that it be diagnosed accurately.

Adult↗
PubMed1992

[The long-term chemotherapy with erythromycin (EM) in chronic lower respiratory tract infections--third report: clinical study of cases administered EM over 3 years].

An investigation was made of the use of EM therapy which began in 1986 or earlier in 31 cases with chronic lower respiratory tract infections. 1) Of the 20 cases in which EM (Erythromycin stearate) administration (600-1200 mg/day) was continued for 3 years or more and its usefulness could be evaluated, treatment with this agent was judged markedly effective in three, effective in 14, somewhat effective in two, and ineffective in one. This amounted to an effectiveness rate (effective or better) of 85%. 2) Improved QOL was observed in 15 of the 20 cases. 3) In the Pseudomonas infected cases, a discrepancy was seen between the effectiveness rate of 87.5% and the disappearance rate of the organism (12.5%), while in the Haemophilus cases no such discrepancy was found (75%). 4) EM administration was stopped in 11 cases because of side effects in two (stomatitis, gastrointestinal disorder) death in five, desire of the patient in three, and transfer to another hospital in one. The cause of death cases had no connection with administration of EM. 5) In the three patients who stopped EM on their own, the agent was again administered because of exacerbation of symptoms, although this readministration proved ineffective in two of the cases. The above results suggest that long term EM therapy is useful and that its continued administration is important.

Adult↗
PubMed1992

[Three cases of lower respiratory tract infection worsened after rhinovirus infection].

We experienced three cases of lower respiratory tract infections worsened after Rhinovirus infection. Case 1: A 42-year-old male with diffuse panbronchiolitis was admitted to our hospital with the complaint of dyspnea on November 21, 1988. Rhinovirus was isolated from nasal washing and P. aeruginosa was cultured from transtracheal aspiration (TTA). Case 2: A 67-year-old male, whose underlying disease was pulmonary asbestosis, was admitted to our hospital complaining of pyrexia on June 12, 1990. Rhinovirus was isolated from TTA and H. influenzae and others were cultured from TTA. Case 3: A 64-year-old male with pulmonary emphysema was admitted to our hospital with a complaint of dyspnea on August 11, 1989. On December 17, 1989 the patient developed rhinorrhea and complained of purulent sputum, pyrexia and dyspnea after five days. Rhinovirus was isolated from nasal washing and TTA and S. nonhaemolyticus and others were cultured from TTA. As indicated in this report, it is interesting to study the relationship between viral infection of the upper respiratory tract and bacterial infection of the lower respiratory tract.

Adult↗
PubMed1992

A new retrovirus packaging cell for gene transfer constructed from amplified long terminal repeat-free chimeric proviral genes.

The retroviral gene transfer system is a powerful tool for somatic gene therapy. A retroviral stock with a high viral titer and lacking replication-competent virus (RCV) is desirable for this type of gene transfer. To fulfill these requirements, we made a new packaging cell line, designated ampli-GPE. To reduce the homology between proviral DNA in the packaging cell and retroviral vector, the gag-pol and env genes of Moloney murine leukemia virus were separated onto two different plasmids, pGP-KV and pENV-KV, respectively, in which the 5' long terminal repeat and the 3' long terminal repeat had been replaced by the mouse metallothionein I promoter or the human beta-globin gene containing the polyadenylation site as control units for the gag-pol and env genes. In addition, these plasmids contained 69% of the bovine papillomavirus gene for gene amplification to obtain production of virus at a high titer. NIH 3T3 clones containing approximately 20 to 50 copies of the gag-pol and env genes were selected and designated ampli-GPE. When ampli-GPE was transfected with the N2 vector or pZipNeoSV(DHFR) derived from pZipNeoSV(X)1, we established clones producing titers of 5 x 10(6) and 1 x 10(6) CFU/ml, respectively. There was no sign of RCV generation in any virus-producing cells from ampli-GPE. However, virus-producing cells derived from psi 2 cells transfected with N2 did generate RCV. Thus, we showed that ampli-GPE, possessing the minimum complement of proviral genes, has potential for the development of a gene transfer system.

3T3 Cells↗
PubMed1992

[Effects of sodium hyaluronate on the nociceptive response of rats with experimentally induced arthritis].

Antinociceptive effects of sodium hyaluronate (Na-HA) were studied on the basis of improvement in the graded abnormal gait elicited by arthritis induced by intra-articular administration of monosodium urate crystal (MSU) to rats. One hour before MSU injection, intra-articular administration of a 1.0% solution of Na-HA with different molecular weights, ranging from 4.70 x 10(5) to 2.02 x 10(6) (HA-200), improved the score of abnormal gait in a molecular weight-dependent manner in the experimental arthritis model. Similarly, administrations of HA-200 at concentrations ranging from 0.1 to 1.0% prior to MSU treatment resulted in improvement of the score in abnormal gait in a dose-dependent manner. To elucidate the antinociceptive mechanisms of Na-HA, effects of pretreatment with Na-HA (1.0%) of different molecular weights on prostaglandin E2 (PGE2) and bradykinin (BK) releases in synovial fluid 3 hr after MSU injection were studied. Increases in PGE2 and BK concentration in the synovial fluid were depressed in a molecular weight-dependent manner by Na-HA (1.0%) pretreatment. These results indicate that Na-HA attenuates the nociceptive responses inflicted by the MSU-induced arthritis. Such an antinociceptive effect may be due to the inhibition of PGE2 and BK synthesis in the synovial joint of rats.

Analgesics↗
PubMed1992

[Urodynamic study on urinary disturbance after therapy of uterine cancer].

It is well known that urinary disturbance often appears after radical hysterectomy for uterine cancer and is aggravated by additional radiation therapy. The aim of this study is to elucidate the pathogenesis and to establish the treatment method of urinary disturbance after therapy for uterine cancer. Forty-five patients with urinary disturbance and ten normal controls were subjected to this study. Changes in clinical symptoms and findings in the Urodynamic study (UDS) in 12 severe cases were investigated before and after treatment with beta 2-stimulant (Mabuterol HCL). Clinical symptoms in cases treated by radiation therapy alone were rare and mild without any pad exchanges, and appeared 5 years after treatment for uterine cancer. Findings of UDS in these cases were mild low compliance of detrusor at maximum desire to void (Cmdv) and mild low bladder volume at maximum desire to void (Vmdv). In cases treated by radical hysterectomy alone, Cmdv decreased immediatelly after the operation and then maximum urethral closure pressure (cPura) gradually decreased. Concerning the cases treated by radical hysterectomy and radiation, severe low Cmdv and severe low Vmdv appeared 5 years after the treatment for uterine cancer in almost all cases, and low cPura appeared immediately after the operation in half of the cases. Treatment with beta 2-stimulant significantly improved urinary frequency, voided volume and urinary incontinence. In UDS findings, Vmdv and Cmdv were significantly improved by the treatment with beta 2-stimulant. The functional profile length and cPura value were not significantly changed. In uroflowmetry, the maximum flow rate and average flow rate were significantly improved by the treatment with beta 2-stimulant.(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenergic beta-Agonists↗
PubMed1992

A 5-lipoxygenase inhibitor, FR110302, suppresses airway hyperresponsiveness and lung eosinophilia induced by Sephadex particles in rats.

To study the role of chemical mediators in airway hyperresponsiveness and simultaneous eosinophilia, we examined effects of a potent 5-lipoxygenase inhibitor FR110302 and those of prednisolone, indomethacin, platelet-activating factor (PAF) antagonist (RP-59227) and leukotriene C4 (LTC4) antagonist (ONO-1078) on airway hyperresponsiveness and lung eosinophilia induced by Sephadex particles. Sephadex G200 particles (2.5 mg/kg) were injected intravenously to rats and 3 days later the airway hyperresponsiveness to acetylcholine (ACh) and the eosinophilia in the bronchoalveolar lavage (BAL) fluids were observed. FR110302 (10 mg/kg b.i.d.p.o.) significantly suppressed both of these indicators of asthma. The amounts of immunoreactive LTB4,C4 (i-LTB4, C4) in the BAL fluid were measured by radioimmunoassay. The amounts of i-LTB4,C4 in the FR110302-treated rats were significantly less compared with that in the Sephadex-injected controls. Prednisolone completely inhibited the airway hyperresponsiveness. PAF antagonist and LTC4 antagonist partially inhibited the airway hyperresponsiveness, and indomethacin had no effect. The results indicate that 5-lipoxygenase products play important roles in the Sephadex-induced airway hyperresponsiveness and lung eosinophilia in rats.

Acetylcholine↗
PubMed1992

[Two cases of diffuse panbronchiolitis receiving long-term erythromycin (EM) therapy with acute exacerbation due to EM-resistant pneumococcus].

The first case was a 73-year-old woman with chief complaints of fever, cough, purulent sputum and dyspnea. EM therapy was begun in December 1983 due to a diagnosis of diffuse panbronchiolitis (DPB). Subsequently, P. aeruginosa was persistently detected, while in February 1991 at the time of an acute exacerbation of the DPB P. aeruginosa and S. pneumoniae were detected by TTA. The second case was a 65-year-old man with chief complaints of fever, cough and purulent sputum. DPB was diagnosed and EM therapy was begun in December 1985. In January 1991, pneumonia developed, at the time when S. pneumoniae was detected by TTA. In both cases, rapid disappearance of S. pneumoniae from the sputum and alleviation of symptoms were obtained with carbapenem antibiotic administration. Both strains were resistant to EM, Tetracycline (TC), Minocycline (MINO) and Clindamycin (CLDM). Particularly, S. pneumoniae of case 2 showed low sensitivity to Ampicillin (ABPC), Cefotiam (CTM) and Cefoxitin (CFX) as well. These cases showed acute exacerbations due to EM-resistant pneumococcus during long-term therapy with EM, and are of interest in that they may shed light on the relation between long-term EM therapy and the emergence of resistant pneumococcus.

Aged↗
PubMed1992

[Nutritional assessment and the effect of supplementary oral nutrition in patients with pulmonary emphysema].

Nutritional status and its relation to respiratory function and respiratory muscle strength were assessed in patients with pulmonary emphysema. Energy metabolism was also examined in order to elucidate the mechanism of their malnutrition. BCAA/AAA ratio of plasma amino acid was positively correlated with FEV1.0%. Resting energy expenditure (REE) was negatively correlated with FEV1.0%, and REE/REEpred ratio was also negatively correlated with BCAA/AAA and PImax. These findings suggest that increased mechanical work load, associated with airway obstruction and reduced respiratory muscle efficiency, contribute to the increased energy expenditure and amino acid imbalance. Oral nutritional supplementation using BCAA enriched-elemental diet was found to be effective, as assessed by nutritional parameters, PImax, D.O.E., and QOL index, in malnourished emphysema patients.

Aged↗
PubMed1992

[Evaluation of tissue eosinophils in eosinophilic pneumonia].

Transbronchial biopsy specimens from ten patients with eosinophilic pneumonia were analysed to see whether the tissue contained activated eosinophils or secreted eosinophil cationic protein. The specimens showed many infiltrated tissue eosinophils in the intraalveolar spaces, and thickened alveolar septae and perivascular areas. Most of these eosinophils stained clearly with degranulation by immunohistochemical studies with monoclonal antibody EG2 (for the secreted form of eosinophil cationic protein), indicating that they were activated eosinophils. On the other hand, although pleural tissue obtained at bullectomy performed after pneumothorax showed eosinophilic infiltration, EG2-positive cells were few. Activated eosinophils may play an important role in the development of pulmonary lesions of eosinophilic pneumonia.

Adolescent↗
PubMed1992

[Extrapyramidal manifestations in hereditary olivopontocerebellar atrophy--clinical study of 10 cases in three affected pedigrees].

We studied 3 pedigrees affected with autosomal dominant olivopontocerebellar atrophy (OPCA), and clinical features of 10 patients were reported. Clinically, 6 cases were dominated with cerebellar ataxia, one with Parkinsonism, and three with choreiform movements. Furthermore, they were characterized by slow eye movement and progressive loss of tendon reflexes. Generally, extrapyramidal manifestations, such as Parkinsonism or choreiform movements, are occasionally observed in dominant OPCA. However, the pathogeneses are different from each other. The choreiform movements are unique in dominant OPCA, and generally not observed in sporadic OPCA. In the distribution of degenerated foci, dominant OPCA is often associated with degeneration of not only substantia nigra, but also with other structures such as dentate nucleus, red nucleus, external segment of globus pallidus (GPe), and subthalamic nucleus. This dentatorubral and pallido-Luysian system degeneration are parts of neuropathological findings in hereditary DRPLA (Naito-Oyanagi form). In both disorders, choreiform movements is observed. Current theory indicates that hyperactivity of neostriatal dopamine neurons and degeneration of GPe play roles in the pathogenesis of chorea. Clinically, choreiform movements are common in hereditary DRPLA, but not in dominant OPCA. This difference could be explained by the nigral degeneration in dominant OPCA, which suppress the generation of choreiform movements.

Adult↗
PubMed1992

[Clinicopathological study of Joseph disease: report of 4 pedigrees and its nosological consideration].

Four pedigrees of Machado-Joseph disease (MJD) were reported. Main clinical features of 21 patients in these pedigrees were cerebellar ataxia, limb spasticity, gaze nystagmus, facio-lingual twitchings, and external ophthalmoparesis. Amyotrophy, hypokinesia, or dystonia were manifested with advance of the illness. In patients with younger onset age, such extrapyramidal signs were dominated. Neuropathological study of one autopsied case disclosed that there were degeneration of spinocerebellar tract, anterior horn cells, pontine nuclei, dentate nucleus, red nucleus, substantia nigra, internal segment of globus pallidus, subthalamic nucleus, and motor nuclei of brain stem; neurons of cerebellar cortex and inferior olivary nucleus were preserved. From these clinical and pathological features, these 4 pedigrees satisfied the criteria of MJD, and were differentiated from hereditary olivopontocerebellar atrophy. Currently, MJD is accepted as a new entity of hereditary spinocerebellar ataxias. However, there are still controversies as to whether Azores-Portuguese MJD and Japanese MJD are identical disorder. Furthermore, the nosological relationship between MJD and a number of similar cases, as reported historically under the diagnosis of Brown type ataxia or Marie's ataxia, has not been clearly established. From reviewing such cases critically, pathological and clinical features of our cases are so similar to those of the latter, indicating that the probably identical genetic disorder has been classified under the different categories.

Adult↗
PubMed1992

[Clinical study of respiratory infection due to Branhamella catarrhalis using transtracheal aspiration].

We clinically investigated 40 cases of respiratory infection due to B. catarrhalis by transtracheal aspiration (TTA). The cases consisted of acute bronchitis (13 cases), pneumonia (14 cases), and chronic lower respiratory tract infection (13 cases). The infection was monomicrobial in 17 cases and polymicrobial in 23 cases with respect to the organisms isolated from TTA. The principal organisms isolated in combination with B. catarrhalis in cases of polymicrobial infection were S. pneumoniae and H. influenzae. All of the 6 cases of death were patients with pneumonia who had malnutrition and immunological hypofunction. These results suggest that B. catarrhalis is an important pathogen in respiratory infection.

Female↗