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Biomedical subjects

K Hamada

Publications and source records attributed to K Hamada.

At least 307 records · Page 17Linked to original sources
PubMed1994

[Suppression of the Pseudomonas aeruginosa-induced biofilm formation on human epithelial cells by erythromycin].

In the present study, were examined the inhibitory effect of erythromycin on the biofilm formation by a temperature-sensitive mutant (Ts25) of Pseudomonas aeruginosa N-42 on the surface of Ishikawa cells which can produce a mucin-like glycoprotein physicochemically similar to mucoproteins produced in the human airway. Usually, 38-45 microcolonies (biofilms) were formed after 10 days of incubation in cultures of Ishikawa cells and P. aeruginosa Ts25. Erythromcin suppressed the adhesion to Ishikawsa cells of P. aeruginosa and its subsequent biofilm formation at doses as low as 0.2 microgram/ml. Erythromycin also exhibited the suppressive effect on the production of glycoproteins by Ishikawa cells at doses higher than 1 microgram/ml and the production of elastase and exoenxyme A from P. aeruginosa at doses higher than 2 micrograms/ml. These results suggest that erythromycin can inhibit the biofilm formation in culture of human epithelial cells and P. aeruginosa and the in-vivo bacterial biofilm formation may be attributed to host cell-derived factors rather than bacterial products.

Biofilms↗
PubMed1994

[An evaluation of pathogens in patients with bronchopulmonary infection by transtracheal aspiration: December 1978-March 1993].

We performed transtracheal aspiration (TTA) in 1165 patients, who were suspected to have bronchopulmonary infection, from December 1978 to March 1993. We isolated pathogens from TTA in 806 patients (69.2%). We isolated H. influenzae (62 cases), S. pneumoniae (39 cases) and M. catarrhalis (24 cases) in patients with acute bronchitis, S. pneumoniae (65 cases), alpha-Streptococcus sp. (52 cases), H. influenzae (32 cases) and S. aureus (29 cases) in patients with pneumonia or lung abscess and H. influenzae (174 cases), S. pneumoniae (84 cases), P. aeruginosa (81 cases) and M. catarrhalis (42 cases) in patients with chronic lower respiratory tract infection. Anaerobic bacteria isolated from TTA included Peptostreptococcus sp. (19 cases), Bacteroides sp. (19 cases) and others. Mycoplasma pneumoniae was isolated from TTA in 8 patients with pneumonia without other organisms. Virus isolated from TTA included Rhinovirus (6 cases) and others. These results suggest that various pathogens affect the pathogenesis of bronchopulmonary infection. Therefore, we must diagnose the bronchopulmonary infection by the correct methods such as TTA.

Adult↗
PubMed1994

[A clinical study of respiratory infections due to mucoid Pseudomonas aeruginosa diagnosed by transtracheal aspiration].

We performed a clinical study of 20 cases (33 episodes) of respiratory infections due to mucoid Pseudomonas aeruginosa by transtracheal aspiration (TTA) in the recent 10 years. There was only one pneumonia without underlying chronic lower respiratory infection (CLRTI) case positive for mucoid P. aeruginosa and others were all CLRTI among 33 TTA trials. In contrast, nonmucoid P. aeruginosa was recovered from 9 cases of respiratory infections without underlying CLRTI among 46 TTA trials. Monomicrobial infection of mucoid P. aeruginosa was 69.7%, and polymicrobial infection containing mucoid P. aeruginosa was 30.3%, and Haemophilus influenzae was the most frequent microorganism recovered with mucoid P. aeruginosa. The recovery rate of mucoid P. aeruginosa among P. aeruginosa-colonized cases was 56.3% in diffuse panbronchiolitis, and that was 42.9% and 40.0% in bronchiectasis and chronic bronchitis, respectively. Mortality due to pneumonia with nonmucoid P. aeruginosa was 46.1%, but there was no fatal pneumonia case with mucoid P. aeruginosa. In CLRTI, laboratory data were not remarkably different between mucoid and non-mocoid P. aeruginosa-colonized cases. Thus, these results suggest that mucoid P. aeruginosa is a more important organism in persistent infections in the lower respiratory tract compared with nonmucoid P. aeruginosa, and further investigations is required on the mechanism and clinical role of this infection.

Adult↗
PubMed1994

[The role of viral infection in adults with bronchopulmonary infections].

We isolated the virus from the respiratory specimens of 16 patients (7.9%) when we investigated the bronchopulmonary infections of 203 adult patients by the viral isolation method for the diagnosis of the viral infection and transtracheal aspiration (TTA) for taking directly the specimen from the lower respiratory tract. The bronchopulmonary infections, isolated the virus, consisted of acute bronchitis (3 cases), pneumonia (8 cases) and the acute exacerbation of chronic lower respiratory infection (5 cases). The positive viral isolation consisted of Rhinovirus (11 strains), Herpes simplex virus I (3 strains), Parainfluenza virus III (1 strain) and Respiratory syncytial virus (1 stain). There were 9 transtracheal aspirates, 8 pharyngeal swabs and 5 nasal washings in the positive viral specimens. We experienced 5 cases who had the same virus isolated from both the upper respiratory tract and the lower respiratory tract. H. influenzae, P. aeruginosa and other bacteria were found in 14 of the 16 TTA cultures. These results suggest that the role of the viral infection is important either independently or relating the bacterial infection in the adult bronchopulmonary infections.

Adult↗
PubMed1994

[A clinical study of Pseudomonas pneumonia diagnosed by transtracheal aspiration].

We performed a clinical study of 16 cases (18 episodes) of Pseudomonas pneumonia by transtracheal aspiration (TTA) from April 1983 to March 1993. The isolation rate of Pseudomonas aeruginosa (P. aeruginosa) among 235 episodes of pneumonias with positive microorganism by TTA was 7.7%. All patients had one or more underlying disease. The most frequent underlying disease was chronic lower respiratory tract infection, followed by lung epidermoid cell carcinoma. More than half of the cases had been given antibiotics prior to the occurrence of pneumonia, and administration of adrenal corticosteroid, heavy smoking habit, and aspiration were seen as other predisposing factors concerning the onset of pneumonias. Monomicrobial infection of P. aeruginosa was 61.1%, and polymicrobial infection containing P. aeruginosa was 38.9%. Community-acquired pneumonia was 61.1% and hospital-acquired pneumonia was 38.9%; the rates of polymicrobial infections and prior administration of antibiotics were higher in the latter group. Mortality due to Pseudomonas pneumonia was 27.8% and the levels of serum albumin and total protein at the onset of pneumonia were significantly lower in the fatal cases than in the recovered cases. It was considered that not only general underlying disease which weaken the immunological resistance of the host, but local bronchial lesion was also important to the onset of the Pseudomonas pneumonia. Also, nutrition is an important prognostic factor on the host's side.

Adult↗
PubMed1994

[Determination of neutrophil function in respiratory infection by chemiluminescence (CL). II: Changes in neutrophil's CL by chemotherapy against chronic lower tract infection].

Neutrophil's CL (CL-index) in were assayed in 18 patients with chronic lower tract infection (13 cases in the exacerbated phase and five cases in the stable phase) three times per case: before, during and after chemotherapy. Before the initiation of chemotherapy, the CL-index.N (neutrophil numbers x CL-index) in patients with exacerbation remained higher than in those without exacerbation. At the exacerbated phase, the CL-index of nine patients and the CL-index.N of 10 patients fell lower than those obtained before treatment. AT the stable phase, the CL-index and the CL-index.N did not change remarkably during and after chemotherapy.

Adult↗
PubMed1994

[Clinical study of pneumonia in elderly patients using transtracheal aspiration (TTA)].

A clinical study was conducted to clarify the clinical state of pneumonia in elderly patients using transtracheal aspiration (TTA). Without prior administration of antibiotics, S. pneumoniae was the most clinically significant in both elderly and non-elderly groups whether the onset of pneumonia was hospital acquired pneumonia or community acquired pneumonia. Compared to the non-elderly group, multiple pathogens were isolated more frequently in the elderly group. Analysis about host factors showed that the number of underlying diseases per patient was more along those with poorer general conditions in the elderly group. The Brinkmann Index was also significantly higher in the elderly group. Clinical examinations before onset of pneumonia indicated that serum total protein, albumin and DNCB skin reaction were significantly lowered in the elderly group. Over the clinical course, the prognosis was poorer and the incidence of adverse reactions of antibiotics tended to be more in the elderly group. These results suggest that a complex clinical background exists for pneumonia of elderly people, related to poorer prognosis. Therefore, more cautious and meticulous care should be provided to elderly patients with pneumonia.

Adolescent↗
PubMed1994

Multifocal eosinophilic granuloma presenting as progressive brainstem and cerebellar dysfunction.

A 55 year old woman with multifocal eosinophilic granuloma (MEG) is described. She developed facial numbness and twitching followed by slowly progressive cerebellar symptoms. Two years later polyuria and polydipsia were noted. A CT of the brain showed multifocal enhancing lesions, and MRI showed areas of hyperintensity on T2 weighted studies in the cerebellar peduncles, pons, and midbrain. Radiographs of the skull, pelvis, and long bones were normal, but a 99mTc diphosphonate bone scan and MRI showed bone lesions compatible with granuloma. The diagnosis of MEG was made by bone biopsy. This is believed to be the first case of MEG with such unusual clinical profiles and radiographical findings. Skeletal surveys are indicated for patients with unexplained focal or multifocal inflammatory changes in the cerebellum.

Biopsy↗
PubMed1994

Androgen action in cultured dermal papilla cells from human hair follicles.

Androgens are major regulators of human hair growth with paradoxically different effects on hair follicles depending on their body site. They stimulate terminal growth in many regions including the face, have no effect on eyelashes, but may cause inhibition and balding on the scalp in genetically disposed individuals. How this occurs is unknown. However, androgens may act on the hair follicle via the cells of the dermal papilla; these would then influence the other cells of the hair follicle by altering the production of regulatory substances such as growth factors and/or extracellular matrix components. Therefore, primary lines of dermal papilla cells have been established from androgen-sensitive hair follicles, such as beard, and control, relatively androgen-independent, non-balding scalp cells and their mechanism of androgen action has been compared. Isolated beard dermal papillae were larger than those from scalp follicles. Although dermal papilla cells did not respond to in vitro androgens by alterations in growth, androgen-dependent dermal papilla cells contained higher levels of specific, low capacity, high affinity androgen receptors than non-balding scalp cells. The ability of the cells to metabolise testosterone to 5 alpha-dihydrotestosterone in culture also varied in parallel to that predicted from studies of hair growth in the 5 alpha-reductase deficiency syndrome. These results support the hypothesis that androgens act via the dermal papilla. They also show that dermal papilla cells retain differences in gene expression in culture which appear to correspond with their androgenic response in vivo. Further studies of such cells should help elucidate why bald men can grow beards!

Androgens↗
PubMed1994

Sequential magnetic resonance features of encephalopathy induced by systemic mastocytosis.

A 37-year-old man developed encephalopathy with prominent eosinophilia. Magnetic resonance imaging (MRI) revealed multiple T2-weighted high signal intensity lesions with dimeglumine gadopentetate (Gd-DTPA) enhancement on T1-weighted images, which were distributed in the cerebral cortex, thalamus, deep white matter and cerebellum. He was diagnosed as having systemic mastocytosis on the basis of proliferating mast cells in the bone marrow and peripheral eosinophilia. Following steroid administration, there was a rapid improvement of his symptoms and laboratory data. To our knowledge, this was the first reported case of systemic mastocytosis provoking encephalopathy with serial MRI findings.

Adult↗
PubMed1994

[Autosomal dominant spinocerebellar degeneration with pigmentary retinopathy in a Japanese family].

We report a pedigree of autosomal dominant spinocerebellar degeneration associated with pigmental retinopathy. The proband is a 75-year-old man. He noticed night blindness at the age of 10 years and a diagnosis of bilateral pigmentary retinopathy was made at age 63. At the age of 65 years, he developed dysarthria and difficulty in walking. At age 69, neurological examination revealed cerebellar signs, and brain CT scans showed mild atrophy of the brain stem and cerebellum. Repeated brain CT scans revealed slight progression of the brain stem and cerebellar atrophy. Molecular genetic studies showed the absence of any mitochondrial DNA mutation at 8993. The father of the proband exhibited cerebellar signs and pigmentary retinopathy. One older brother had cerebellar signs and another had pigmentary retinopathy. To our knowledge, hereditary spinocerebellar degeneration with retinal degeneration is rare in Japan. This study is the first full report on hereditary spinocerebellar degeneration with pigmentary retinopathy in Japan, although an abstract was published by Konishi et al. We also discuss the neuropathological discordance on hereditary olivoponto-cerebellar atrophy with retinal degeneration.

Adult↗
PubMed1994

Localization of mRNA of procollagen alpha 1 type I in torn supraspinatus tendons. In situ hybridization using digoxigenin labeled oligonucleotide probe.

A tendon is predominantly composed of collagen Type I. To determine the synthesis of collagen Type I after a rotator cuff tear, an in situ hybridization technique was applied to localize cells containing procollagen alpha 1 Type I in the proximal stump of five torn supraspinatus tendons obtained during surgery. Specimens were fixed in 10% buffered formalin, embedded in paraffin, and sectioned at 6 microns. A 22 mer oligonucleotide corresponding to a sequence coding a part of human procollagen alpha 1 Type I messenger RNA (mRNA) was used as a hybridization probe. The probe was 3'-end labeled with digoxigenin-11-dUTP, and the probe-mRNA hybrids were enzymatically visualized using conventional chromogens for alkaline phosphatase. The procollagen alpha 1 type I mRNA was clearly observed in the cells near the margin of the tear. However, they were not consistently found in the vicinity of the intratendinous extension of the tear and in cells of the subacromial bursa. It is concluded that this method should be used to study the characteristics of collagen synthesis in a torn rotator cuff tendon.

Digoxigenin↗
PubMed1994

Pathology and pathogenesis of the intratendinous tearing of the rotator cuff viewed from en bloc histologic sections.

Histologic sections from 17 en bloc surgical specimens were studied to clarify the pathogenesis of intratendinous tears of the rotator cuff. The specimens consisted of the bony insertion, the partially torn area, and the musculotendinous junction of the supraspinatus tendon. An intratendinous tear alone was present in two patients, and was associated with bursal side cuff tears in seven patients and joint side cuff tears in eight. There were 13 men and 4 women, whose average age was 49.8 years. Trauma was noted in all intratendinous tears and combined intratendinous and joint side cuff tears and in two of the seven patients who had intratendinous plus bursal side tears. All patients exhibited clinical evidence of subacromial impingement. Histologic sections were stained with azan and hematoxylin and eosin. Microscopically, the sections demonstrated several abnormalities in addition to degeneration. The intratendinous tears was located in the midlayer of the tendon in 15 specimens and eccentrically in two, the axis of which were parallel to tendon fibers in all. The intratendinous tears continued to local disruptions of the enthesis in 11 cases. The inner surface of the tear appeared smooth in 16 specimens. Despite the presence of granulation tissue and vessel proliferation near the intratendinous tears, there was no evidence of closure of the defect in any specimen. Intratendinous tears develop between superficial and deep layers of the degenerated rotator cuff. Shear within the tendon appears to be responsible in pathogenesis. Concomitant subacromial bursitis is very common.

Adult↗
PubMed1994

[Expression of activation antigen, CD69, on human local eosinophils].

The activation antigen, CD69, has been shown to be expressed on activated lymphocytes. CD69 has also been shown to be associated with the signal transduction process. Recently, we demonstrated the expression of CD69 on lung eosinophils obtained from the bronchoalveolar lavage fluid of patients with eosinophilic pneumonia. In this study, we performed flowcytometric analysis of CD69 expression on eosinophils obtained from the bronchoalveolar lavage fluid, pleural effusion or peripheral blood of various patients. Whatever the disease, local eosinophils expressed significant levels of CD69, whereas most peripheral blood eosinophils did not express CD69. These findings suggest that CD69 is a marker for local eosinophils and that local eosinophils may differ functionally from peripheral blood eosinophils.

Adult↗
PubMed1994

[Aluminum lung].

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Aluminum↗