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Biomedical subjects

T Nagatake

Publications and source records attributed to T Nagatake.

At least 91 records · Page 5Linked to original sources
PubMed1996

[Clinical study of 18 patients whom MRSA was detected from stool--especially about comparison enterocolitis with colonization].

We studied the clinical aspects of 18 patients from whom MRSA was detected from the stool and compared with 9 enterocolitis cases (7 male, 2 female, median age 72.4 y.o.) with 9 colonization cases (5 male, 4 female, median age 70.2 y.o.) from 1991 June to 1995 May. Cases of postoperative, use of anti-peptic ulcer drugs and administration of antibiotics for enterocolitis were more than that of colonization. On the other hand, eatable patients in the colonization group who could take food orally were more in number. Many patients of both enterocolitis and colonization were colonized in the respiratory tract. Drug sensitivity of MRSA in both cases were almost the same and the coagulase type were all that of II. Three courses on how MRSA enterocolitis occurs is considered. At first, colonization in the respiratory tract, second, proliferation of MRSA in the higher pH gastric juices as a result of gastrectomy or use of anti-peptic ulcer drugs, and third, selection of MRSA after administration of antibiotics.

Aged↗
PubMed1996

A monoclonal antibody reactive with a common epitope of Moraxella (Branhamella) catarrhalis lipopolysaccharides.

A hybrid cell line producing a monoclonal antibody (MAb) against Moraxella (Branhamella) catarrhalis lipopolysaccharide (LPS) was established. The specificity of the MAb 1B12 to purified rough LPSs from six strains of M. catarrhalis was ascertained by enzyme-linked immunosorbent assay (ELISA), competitive-inhibition ELISA, and immunoblotting. MAb 1B12 bound to live bacterial cells and culture supernatants from a total of 34 strains of M. catarrhalis, including 12 strains with different LPS serotypes. No cross-reactions with smooth and rough LPSs from selected enterobacterial and nonenterobacterial strains, with other respiratory pathogens, or with Neisseria species were observed. These data suggest that MAb 1B12 recognizes a common epitope of M. catarrhalis LPS which differs from serotype determinants.

Antibodies, Monoclonal↗
PubMed1996

Loss of tumor necrosis factor production by human monocytes in falciparum malaria after their maturation in vitro.

In Plasmodium-infected mammals, phagocytosis and production of tumor necrosis factor (TNF) by monocytes and macrophages are prominent features. The present work aimed at clarifying the relationship between the maturation of human monocytes to macrophages and their TNF productivity and phagocytic ability in the presence of Plasmodium falciparum-infected erythrocytes. Fresh monocytes produced a significantly higher quantity of TNF in the presence of schizont-infected erythrocytes than macrophages obtained by in vitro monocyte maturation on autologous serum, whereas phagocytic activity of macrophages was much higher than that of fresh monocytes. This indicated that the TNF-inducing factors from P. falciparum-infected erythrocytes could stimulate fresh monocytes, but not macrophages, to release TNF, regardless of their development of phagocytosis. Activation of macrophages by interferon-gamma could not recover their TNF productivity in the presence of P. falciparum-infected erythrocytes, but it enhanced their TNF productivity in the presence of lipopolysaccharide(s). The TNF-inducing factors were contained mainly in erythrocytes infected with mature schizonts but not in erythrocytes infected with the younger stages of the parasites. Fractionation of infected erythrocytes revealed that both soluble and insoluble components almost equally contained those factors.

Animals↗
PubMed1995

Corynebacterium pseudodiphtheriticum: a respiratory tract pathogen.

From January 1986 through February 1993, there were 16 episodes of respiratory infection due to Corynebacterium pseudodiphtheriticum in 13 patients. The ages of patients ranged from 24 to 77 years; the ratio of male to female patients was 3:1. One patient had three episodes of infection, and another patient had two. In one patient, who died of disseminated intravascular coagulation, the level of IgG was low. One patient was receiving prednisolone when the infection occurred. In two cases a mixed infection with Streptococcus pneumoniae was noted. Sputum cultures yielded C. pseudodiphtheriticum (> or = 10(7) cfu/mL). An increased neutrophil response in the sputum of infected patients was observed. Gram staining and electron microscopy of sputum showed phagocytosis of C. pseudodiphtheriticum by the neutrophils. ELISAs also showed an increase in the level of immunoglobulin against C. pseudodiphtheriticum after infection. Tests for determination of MICs of antibiotics revealed that C. pseudodiphtheriticum isolates were susceptible to ampicillin, amoxycillin/clavulanic acid, cefazolin, cefuroxime, ceftazidime, and imipenem. All strains were resistant to nalidixic acid; borderline susceptibility to ofloxacin, norfloxacin, and ciprofloxacin was noted. We suggest the use of beta-lactam antibiotics in the treatment of infection with C. pseudodiphtheriticum.

Adult↗
PubMed1995

Clinical evaluation of polymerase chain reaction DNA amplification method for the diagnosis of pulmonary tuberculosis in patients with negative acid-fast bacilli smear.

We evaluated the sensitivity and specificity of polymerase chain reaction (PCR) for the detection of Mycobacterium tuberculosis among 109 patients who were suspected to have active pulmonary tuberculosis (PTB) and showed negative acid-fast bacilli (AFB) smears in a total of 393 samples of sputum (169), gastric aspirate (134), and urine (90) which fulfilled different criteria for the positivity of PCR. The patients were subsequently divided into one group of active PTB composed of 15 patients with definite PTB and 43 patients with highly suspected PTB, and another group of 51 non-active PTB patients. The PCR assay using samples of sputum and gastric aspirate proved to be specific for active PTB. The PCR method for diagnosis of active PTB using sputum samples was sensitive (97.8%) but lacked specificity (27.0%) when regarded as PCR positive when at least one positive reaction was obtained among all samples examined. However, the PCR of gastric aspirate demonstrated a sensitivity of 63.4% and a specificity of 76.7%. Our data supports that the PCR method for detecting active PTB in AFB smear negative patients using gastric aspirate shows markedly improved sensitivity over the conventional method (25.9%), although it still lacks specificity. PCR assay for M. tuberculosis using multiple samples of gastric aspirate in conjunction with careful clinical observations for the presence of active infection is essential for the diagnosis of active PTB among patients with negative AFB smear.

Bacteriological Techniques↗
PubMed1995

[Clinical study of radiation pneumonitis over 10 years].

We studied clinical aspects of radiation pneumonitis from 1983 to 1992. Fifty seven patients admitted to our hospital because of lung cancer were treated with radiotherapy, and radiation pneumonitis developed in 20 (35.1%). The incidence of radiation pneumonitis was closely related to male sex, chronic obstructive lung disease, and chemotherapy. Pneumonitis was not related to age, or to the area or amount of radiation. Eighteen cases (90%) of pneumonitis occurred during or within one month after radiotherapy. In all but five cases (25%), pneumonitis was limited to the area of radiation. Treatment was mainly with steroids. In 4 cases (20%), pneumonitis recurred when steroid therapy was reduced, and five patients (10%) died.

Aged↗
PubMed1994

The role of MRSA (methicillin-resistant Staphylococcus aureus) adherence and colonization in the upper respiratory tract of geriatric patients in nosocomial pulmonary infections.

The mechanism of nosocomial respiratory infections caused by MRSA (methicillin-resistant Staphylococcus aureus) in geriatric patients was investigated. Seriously ill patients (SIP) undergoing naso-gastric tube feeding or intravenous hyperalimentation and moderately ill patients (MIP) who were orally fed, were examined for their colonization and infection by Staphylococcus aureus (S. aureus) in the respiratory tract. Colonization of MRSA in the upper respiratory tract in SIP was from six to ten times higher than that in MIP and was associated with a high incidence of MRSA pulmonary infections. In vitro S. aureus adherence to nasal or oropharyngeal cells demonstrated that bacteria binding to nasal cells was higher, which probably can be interpreted as an elevated occurrence of S. aureus colonization in the nasal cavity than in the throat. The binding activity of MRSA was not superior to that of MSSA (methicillin-sensitive S. aureus). Though MRSA binding to the nasal cells from SIP was not higher than those from MIP, MRSA colonization in the upper respiratory tract was more frequently seen in SIP (P < 0.01). A higher incidence of total infectious episodes (P < 0.02-0.001) and more frequent use of antibiotics (P < 0.02-0.001), which were potent against MSSA might be the basis for selection of MRSA in these patients. In fact, the rate of MRSA colonization on the skin (pressure sores) was also higher in SIP (P < 0.01). A low nutritional state in SIP (P < 0.01-0.02) might also be associated with MRSA colonization.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

Expression of fimbriae and host response in Branhamella catarrhalis respiratory infections.

Sputum during the acute exacerbation of chronic respiratory diseases were observed under the electron microscope, to determine the in vivo expression of surface structures of Branhamella catarrhalis (B. catarrhalis), the polymorphonuclear neutrophil (PMN) response to B. catarrhalis infections, and the composition of sputum. It was found that during infection fimbriae are expressed in B. catarrhalis. However, there were sparsely to densely fimbriated bacteria in each sputum sample. The length of the fimbriae were from 50 to 76 nm. In the sparsely fimbriated B. catarrhalis, external to the cell wall, a thin, granular, electron-dense layer was observed. Due to the presence of fimbriae, this layer was not seen in densely fimbriated B. catarrhalis. Blebs were also found in B. catarrhalis. PMNs were found to phagocytose both B. catarrhalis and debris. Evidence was found that debris were formed mainly by the destruction of PMNs. Bacteria as well as debris were phagocytosed by PMNs.

Adult↗
PubMed1994

[Clinical significance of positive blood cultures in the Nagasaki Rosai Hospital during the past 6 years].

In this clinical study we tried to find out the clinical significance of positive blood cultures between Jan. 1984 and Dec. 1989 in the Nagasaki Rosai Hospital. In this period the association between the isolated bacteria from blood cultures (398 specimens: 17.9%) and clinical background were evaluated. Each year the positive cultures were seen in about 18-20%. The distribution of bacteria showed increase percentage of the gram-positive organisms such as coagulase-negative Staphylococcus. Gram-negative organisms in included P. aeruginosa, A. calcoaceticus and E. coli. A. calcoaceticus was frequently found from the dept. of neurosurgery. Fungus, mostly Candida, was isolated in about 10-20%. The specimens were provided from department of internal medicine (62.9%) and neurosurgery (22.8%). An analysis of 213 episodes of 188 bacteremic cases was made. The onset of bacteremia had two peaks, 24 h or 1 month, after admission. The primary infected sites were the urinary tract (26.7%), respiratory system (14.5%) and central nervous system (6.1%). The central venous catheter was an important infected site. The major underlying diseases included acute cerebrovascular diseases, cardiac failure due to valvular heart diseases or acute myocardial infarction and/or iatrogenic immunocompromised state. The major complications were disseminated intravascular coagulation (DIC) (24.4%) and multiple organ failure (MOF) (8.9%). Half of the DIC episodes was caused by gram-positive cocci such as CNS, E. faecalis and MRSA. 68.4% of MOF episodes was associated with gram-negative bacteria. While the remainder was caused by gram-positive cocci including CNS and MRSA.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1994

Role of interleukin-8 (IL-8) and an inhibitory effect of erythromycin on IL-8 release in the airways of patients with chronic airway diseases.

To evaluate of the role of interleukin-8 (IL-8), a chemotactic cytokine, in the continuous neutrophil accumulation in the airways of patients with chronic airway disease (CAD) and persistent Pseudomonas aeruginosa infection, we investigated the cell population, IL-8 levels, IL-1 beta levels, tumor necrosis factor (TNF) activities, and neutrophil elastase (NE) activities of bronchoalveolar lavage (BAL) fluids in 17 CAD patients (with P. aeruginosa infections [CAD+PA], n = 9; without any bacterial infections [CAD-PA], n = 8) and 8 normal volunteers. We found significant elevations of neutrophil numbers, IL-8/albumin ratios, and NE/albumin ratios in BAL fluids from CAD patients, in the following rank order: CAD+PA > CAD-PA > normal volunteers. IL-1 beta/albumin ratios were elevated only in CAD+PA, while no TNF bioactivity was detected in BAL fluids. The neutrophil numbers correlated significantly with the IL-8/albumin ratios and NE/albumin ratios in the BAL fluids of CAD patients. When anti-human IL-8 immunoglobulin G was used for neutralizing neutrophil chemotactic factor (NCF) activities in BAL fluids, the mean reduction rate of NCF activities in CAD+PA patients was significantly higher than that in CAD-PA patients. We also evaluated the effects of low-dose, long-term erythromycin therapy in BAL fluids from three CAD+PA and two CAD-PA patients. Treatment with erythromycin caused significant reductions of neutrophil numbers, IL-8/albumin ratios, and NE/albumin ratios in BAL fluids from these patients. To elucidate the mechanism of erythromycin therapy, we also examined whether erythromycin suppressed IL-8 production by human alveolar macrophages and neutrophils in vitro. We demonstrated a moderate inhibitory effect of erythromycin on IL-8 production in Pseudomonas-stimulated neutrophils but not in alveolar macrophages. Our data support the view that persistent P. aeruginosa infection enhances IL-8 production and IL-8-derived NCF activity, causing neutrophil accumulation in the airways and the progressive lung injuries observed in patients with CAD. The clinical efficacy of erythromycin therapy for CAD patients might be partly mediated through a reduced IL-8 production, diminishing neutrophil accumulation and NE release in the airways.

Adult↗
PubMed1994

[A case of sarcoidosis with middle lobe atelectasis].

We report a case of sarcoidosis complicated by middle lobe atelectasis. A chest radiograph and a chest CT film on admission revealed middle lobe atelectasis and mediastinal lymphadenopathy. Bronchofiberscopic findings showed slit-like stenosis and reddish, edematous mucosal change of the middle lobe orifice. On admission, the serum angiotensin-converting enzyme (ACE) level was within the normal range. However, the ACE level had increased beyond the normal range by 2 months later, histological examination of a specimen from a transbronchial lung biopsy (TBLB) of the middle lobe revealed noncaseating epithelioid cell granulomas. We diagnosed sarcoidosis because of the histological findings from the TBLB and serum ACE elevation. Treatment with predonisolone resulted in remarkable alleviation of middle lobe atelectasis and mediastinal lymphadenopathy. Cases of sarcoidosis with middle lobe atelectasis are rare in Japan.

Bronchoscopy↗
PubMed1994

[Intractable bacterial infection--review].

The factors involved in the mechanism of intractable bacterial infections are systemic, local and iatrogenic compromised conditions which mean the deficiency of host defence. From our results, especially on diffuse panbronchiolitis with Pseudomonas aeruginosa, we have learned about the harmful effects of destroyed neutrophils accumulated in bronchial and bronchiolar trees. Although low doses of erythromycin therapy is effective for intractable DPB. There are many evidences on the mechanisms for this treatment reported by Japanese researchers. We also reported our data of IL-8 level in BALF after this treatment. Bacterial factors of intractable processes are also important.

Bronchi↗
PubMed1994

[Gram-negative coccus infection].

The main pathogens of gram-negative infections are Neisseria gonorrhoeae, Neisseria meningitidis and Moraxella catarrhalis infection. N. Gonorrhoeae infection is one of the STD, but the chemotherapy for this infection is very easy because this pathogen is very susceptible to new quinolones. Meningococcal infection is very rare in Japan. Since 1980, M. catarrhalis is one of the important pathogen of respiratory infections such as acute bronchitis, pneumonia, chronic bronchitis. This pathogen also causes acute sinusitis and otitis. Most pathogenic strains of M. catarrhalis are beta-lactamase producing.

Animals↗
PubMed1993

Neutrophil response to Pseudomonas aeruginosa in respiratory infection.

Sputum from patients with acute exacerbation of respiratory infection by Pseudomonas aeruginosa was observed under the electron microscope. External to the cell wall of P. aeruginosa a granular, electron-dense material was observed which is suggestive of capsule. It is supposed that stabilization of capsule occurred by the host antibody, which was produced due to chronic infection by P. aeruginosa. Mucoid type of microcolonies were observed with a fibrous matrix of exopolysaccharide. Other types of microcolonies were surrounded by granular substances or fine fibers. Neutrophil was found to be partially surrounding the microcolony in an attempt to defense. Debris was formed mainly by the destruction of the neutrophil. Most neutrophils were found full of phagocytosed debris; in contrast only a few neutrophils were found to have phagocytosed P. aeruginosa. This study concludes that instead of phagocytosing bacteria, neutrophil phagocytosed debris and bacteria were not completely eradicated. Therefore, this might be one of the factors in the pathogenesis of respiratory infection and persistent colonization by P. aeruginosa.

Aged↗
PubMed1993

Neutrophil response to nontypable Haemophilus influenzae in respiratory infections.

Sputa from patients with respiratory infections by nontypable Haemophilus influenzae (H. influenzae) were investigated by electron microscopy. The cell wall of H. influenzae appeared wavy and nonwavy. In the cell wall the peptidoglycan layer was ill-defined. These patients had adequate IgG response in the serum against H. influenzae. However neither capsule nor fimbriae were found. Different stages of phagocytosis and destruction of the bacteria by polymorphonuclear neutrophils (PMN) were observed. PMNs were also found to phagocytose the debris. Evidences were found that the debris is formed mainly by the destruction of polymorphonuclear neutrophil. Extracellular lysosomes were also observed, which may have a role in destruction of both bacteria and host tissue. It was concluded that nontypable H. influenzae are nonfimbriated and noncapsulated during infection. Debris are the end product of PMN destruction, and phagocytosis of debris by PMNs has a role in the pathogenesis of chronic respiratory diseases.

Adult↗