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Biomedical subjects

M Aihara

Publications and source records attributed to M Aihara.

At least 37 records · Page 2Linked to original sources
PubMed2001

Detection of prostaglandin EP(1), EP(2), and FP receptor subtypes in human sclera.

PURPOSE: To examine the expression of five prostaglandin (PG) receptors, EP(1), EP(2), EP(3), EP(4), and FP and their corresponding mRNA transcripts in human sclera and cultured human scleral fibroblasts (HSFs). METHODS: Primary cultures of HSFs were established from donor eyes. Also, sclera from human donor eyes was snap frozen and sectioned. Immunocytochemistry was performed on HSFs and tissue sections with subtype-specific antibodies to the EP(1), EP(2), EP(3), EP(4), and FP receptors. The presence of mRNA for the receptor subtypes was examined from total RNA obtained from human sclera and confirmed with restriction digest analysis. RESULTS: Positive EP(1) and FP receptor immunoreactivity was observed in fibroblasts within the sections from human sclera. In primary cultures of HSFs, EP(1) and FP labeling was observed over the entire cell surface. EP(2) immunoreactivity within HSFs was mostly present in the juxtanuclear region. RT-PCR analysis of total RNA isolated from human sclera and HSFs confirmed the presence of EP(1), EP(2), and FP receptor subtypes. The identity of the polymerase chain reaction products was confirmed by restriction enzyme analysis. No mRNA or immunoreactivity above basal levels was detected for the EP(3) and EP(4) prostanoid receptor subtypes in tissue sections or primary cultures. CONCLUSIONS: The EP(1), EP(2), and FP receptor subtypes are present in HSFs, suggesting that these cells may respond to endogenous PGs and their structural analogues through interaction with these receptor subtypes.

Adult↗
PubMed2000

New EIA technique for tyrosinase in human melanocytes and its application.

The expression of tyrosinase in melanocytes relates to skin pigmentation or depigmentation. Although many types of drugs with whitening effects are well known, neither the definite effect nor the mechanism underlying the effect has been elucidated. In this study, we attempted to develop the rapid and simple EIA technique for tyrosinase protein, then this technique was applied to normal human cultured melanocytes. When primary antibody and tyrosinase were incubated in non-coated 96-well microtitre plates for 48 hours at 4 degrees C, then the solution in tyrosinase-coated plate was further incubated for another 1 hour at 37 degrees C. Thus the best results were obtained. The developed EIA system could detect authentic tyrosinase until 0.1-1.0 ng/mL. This EIA technique could also be applied to human cultured melanocytes. The melanocytes cultured with endothelin-1 induced tyrosinase like immune reactive protein. The protein induction with endothelin-1 was suppressed by BQ 123, ETa receptor antagonists. The simple EIA technique developed for tyrosinase may give a clue to determination of the onset mechanisms underlying pigmental diseases of the skin as well as the mechanisms underlying the effects of various whitening drugs.

Cells, Cultured↗
PubMed2000

Expression of lysophosphatidic acid receptor in rat astrocytes: mitogenic effect and expression of neurotrophic genes.

Lysophosphatidic acid (LPA) is a phospholipid mediator with a variety of biological activities. It remains unknown, however, which cells in the brain express the LPA receptor. The present study was undertaken to identify cells in the rat brain expressing functional LPA receptors, and to explore biological roles of LPA in these cells. We found that the LPA receptor was most dominantly expressed in rat astrocytes, determined by LPA-induced Ca2+ imaging, and by Northern blot analyses. LPA induced a mitogenic response and expression of immediate early genes in astrocytes, through pertussis-toxin sensitive G-protein(s). LPA also stimulated the expression of various cytokine genes, including nerve growth factor, interleukin (IL)-1beta, IL-3 and IL-6. Thus, astrocytes are the major target of LPA in the brain. We propose that LPA may play important roles in neuronal development, gliosis and wound-healing process in the brain.

3T3 Cells↗
PubMed2000

Interaction between neurone and microglia mediated by platelet-activating factor.

BACKGROUND: Platelet-activating factor (PAF) is a potent phospholipid mediator that plays various roles in neuronal function and brain development. The production and release of PAF in the brain has also been reported under various pathological conditions. However, neither the cell types and mechanism responsible for the synthesis of PAF nor its target cells have been fully identified. RESULTS: Using primary culture cells derived from rat brain and a very sensitive assay method for PAF, we found that PAF was synthesized in neurones following stimulation with glutamic acid. PAF synthesis required activation of NMDA receptors and subsequent elevation of intracellular calcium ions. Microglia, which express functional PAF receptors to a high level, showed a marked chemotactic response to PAF. This chemotaxis is a receptor-mediated process, as microglia from PAF-receptor-deficient mice did not show such a response. The activation of a pertussis-toxin-sensitive G-protein and mitogen-activated protein kinase presumably plays a role in intracellular signalling leading to chemotaxis. CONCLUSIONS: Considering the cytoprotective and cytotoxic roles of microglia, PAF functions as a key messenger in neurone-microglial interactions.

Animals↗
PubMed2000

[A SHV-derived extended-spectrum beta-lactamase (SHV-12) produced by an Escherichia coli recovered from wound abscess in post operative case with rectal carcinoma].

A 62-year-old woman admitted for rectal carcinoma suffered from a post-operative bacterial infection. Oxy-imino-beta-lactams including cefotiam (CTM) and cefozopran (CZOP) were prescribed for this case, but the patient developed a wound abscess followed by peritonitis. She recovered from the bacterial infection after drainage and recurrent washing of the abscess. An ephemeral aggravation of infectious signs was observed just after creation of an artificial anus, and CZOP was again administered, and no evident bacterial infection occurred. The patient recovered, then was followed as an outpatient to date. A CAZ-resistant (MIC, > 16 micrograms/ml) E. coli was recovered from pus of her wound abscess. Since the CAZ-resistance decreased (MIC, 64 micrograms/ml-->0.13 microgram/ml) by the presence of clavulanate (CVA) in this isolate, this strain was speculated to be an extended spectrum beta-lactamase (ESBL) producer at an early stage of infection. A similar strain was also isolated from the feces. Therefore, we immediately took measures to block the nosocomial spread of this microorganism, and we succeeded in preventing a nosocomial outbreak of this strain. It was later confirmed by PCR analysis and DNA sequencing analysis that this CAZ-resistant E. coli strain produces an ESBL (SHV-5-2a = SHV-12). This is the first report of a case of infection with SHV-derived ESBL producing E. coli strain in Japan. We are concerned that further dissemination of this kind of microorganism might occur in the near future also in Japan, as it has been widely observed in European countries and the US. We believe that it will be very important to distinguish the type of beta-lactamases for rigorous bacterial infection control with the prudent use of antibiotics. In other words, we in Japan must recall that various gram-negative bacterial species that produce TEM-, SHV-derived ESBLs, Toho-1, AmpC, or IMP-1 are already widespread. Thus, we should take this fact into consideration when we do antibiotic susceptibility tentings and interpretation of the results for promotion of accurate chemotherapy.

Abscess↗
PubMed2000

[Detection of extended spectrum beta-lactamases producing Enterobacteriaceae in feces].

A study was made of 366 feces for detection of extended spectrum beta-lactamases producing Enterobacteriaceae from feces. The selective agar was used for modified drigalski agar (Eiken Chemical Co., LTD) with 2 micrograms/ml cefotaxime (ESBL screen agar). 92 strains of Enterobacteriaceae, 41 Escherichia coli, 15 Citrobacter freundii, 13 Enterobacter cloacae, 11 Klebsiella pneumoniae, and other 12, were isolated from ESBL screen agar. And, R-plasmid that were selected by 2 micrograms/ml cefotaxime were transferred by conjugation from two of the 92 strains. These strain were E. coli TH9809927 and Proteus mirabilis TH9808262 that were amplified by "Toho-1 type" primer. The clude enzyme from two strains (donor) and transconjugants were especially hydrolysed cepharoridine and cefotaxime. Accordingly, two strains (0.5%) were detected as ESBL producers. We think that the result of our survey suggests the increase of ESBLs producing bacterial infection in Japan, and believe that there is a trend of infection of its by surveilance of the feces.

Bacteriological Techniques↗
PubMed2000

Effects of N-acetylcysteine and ambroxol on the production of IL-12 and IL-10 in human alveolar macrophages.

BACKGROUND: N-acetylcysteine (NAC) and ambroxol (AMB) have recently been proposed as possible therapeutic agents in the treatment of pulmonary disorders. IL-12 plays an important role in host resistance to infection and the development of Th-1 cells. In contrast, IL-10 is involved in anti-inflammatory and immunoregulatory mechanisms. OBJECTIVE: We investigated the effects of NAC and AMB on secretions of IL-12 and IL-10 from human alveolar macrophages. METHODS: Alveolar macrophages were obtained from 7 healthy nonsmokers by bronchoalveolar lavage. The cells were first incubated with either NAC or AMB for 2 h and then cultured in lipopolysaccharide (LPS) solution for 24 h. IL-12 and IL-10 secretions were measured by ELISA. RESULT: Both NAC and AMB enhanced LPS-induced secretion of IL-12. NAC also enhanced LPS-induced IL-10 secretion, while AMB did not. The ratio IL-12/IL-10 secretion was increased by AMB, but NAC did not affect it. CONCLUSIONS: The results suggest that NAC enhances inflammatory and immune responses and prevents excessive responses reciprocally, through keeping local balance of IL-12 and IL-10 production in alveolar macrophages at inflammatory sites of bacterial pneumonia. AMB appears to strengthen inflammatory responses and cell-mediated immunity, facilitating the development of Th-1 cells, through shifting the local balance to IL-12 dominance.

Acetylcysteine↗
PubMed2000

[Quality control on antimicrobial susceptibility testings].

Performance of quality control in the clinical microbiological laboratory is markedly behind that of other laboratories. In particular, it remains indispensable even if the antimicrobial susceptibility test being carried out is standardized. In Japan, a standardized method of antimicrobial susceptibility testing has recently been established by the National Committee for Clinical Laboratory Standards and Japan Society of Chemotherapy. However, most laboratories do not perform quality control for antimicrobial susceptibility testing according to the standardized rules. The problem in quality control in laboratories causes things to remain as they are. As a review of laboratory quality control methods, we will show several cases of error that we encountered in our laboratory.

Japan↗
PubMed2000

[Evaluation of MAST-26, newly developed system for the detection of IgE antibodies].

MAST-26 is a new allergy testing system which allows simultaneous determination of allergen-specific IgE antibody levels for 26 allergens using 200 microliters of patient serum. To evaluate the effectiveness of MAST-26 for the detection of allergen-specific IgE antibody, a total of 100 serum samples were collected from allergic patients at five facilities, and allergen-specific IgE antibody was measured by MAST-26. 14% of them were positive to > or = 10 allergens. If the patients had severe allergic symptoms, they were likely to show positive to many allergens. A good correlation was found between the results obtained by MAST-26 with those measured by CAP RAST and by intradermal skin test. It was concluded that MAST-26 is an effective screening method for the detection of allergen-specific IgE.

Allergens↗
PubMed2000

[A relationship between a psychosomatic and a skin condition in patients with atopic dermatitis].

Atopic dermatitis (AD) has been clinically well-known to be frequently exacerbated by some psychosomatic stress. In this study, we examined a relationship between a psychosomatic and a skin condition in patients with AD. Visual analogue scale (VAS) for the grade of general physical condition, mental stress and others were reported daily for themselves, while skin physiological parameters, resident skin bacteria and a psychological questionnaire (POMS) were measured every 2 weeks. It was observed that tense-anxious and depressive scores of POMS tended to correlate with skin conductance, a skin clinical score and a number of total skin bacteria and others. These results suggest that changes of psychosomatic condition reciprocally correlate with the exacerbation and improvement of skin symptom in patients with AD.

Adolescent↗
PubMed2000

[A case of atopic dermatitis which showed correlation of psychological state and lesions--changes of value of psychological test, skin lesion and NK cell activity].

The relationship between psychological state and skin lesions of atopic dermatitis were investigated with a 31-year-old male patient. He had severe atopic dermatitis which became worse with psychological stress. A psychological test, profile of mood states (POMS), was performed on him every 2 weeks. Peripheral lymphocytes and natural killer (NK) cell activity were investigated at some points. When the psychological state showed more depressive, anxiety, anger, fatigue and confusion, the skin lesions became worse and recovered after the psychological states turned well. Correlation was shown between itch and stress or fatigue by a visual analogue scale (VAS) (p < 0.001). NK cell activity decreased during the worse psychological state and recovered during the near normal psychological state, although, the lymphocyte count and CD4/8 ratio in peripheral blood did not change during the study. These results suggest that some patients with atopic dermatitis should be treated psychologically in addition to standard dermatological treatment.

Adult↗
PubMed2000

Midgut malrotation in adulthood.

A 29-year-old man was admitted to our hospital with a history of recurrent right upper quadrant abdominal pain and vomiting. These symptoms appeared intermittently for 7 years. Various examinations revealed a diagnosis of midgut malrotation. Laparotomy was performed and revealed reverse rotation of the duodenum with paraduodenal hernia and a normal rotating colon. This case suggests that recurrent abdominal complaints in an adult should arouse suspicion of midgut malrotation.

Abdominal Pain↗
PubMed2000

[Pseudomonas aeruginosa].

We investigated the causes of nosocomial infection of P. aeruginosa in a recent outbreak of P. aeruginosa in our hospital. Multi-drug-resistant-P. aeruginosa(MDRPS) that did not produce class B beta-lactamase was isolated from 20(40.0%) patients, occurring in 50 patients hospitalized in the Internal Medicine Ward E in our hospital in 1999 was investigated. All of the patients had brain-vesicular damage as the underlying disease, and 12 patients had been fed by nasal feeding or through a gastric stoma. MDRPS was isolated from sputum(7), urine samples(8), wound discharge(4) and 1 catheter. The bacteria were resistant to piperacillin, ceftazidime, sulbactam/cefoperazone, minocycline and ofloxacin, and in 40% the MIC of the imipenem was more than 8 micrograms/ml. We did not detect MDRPS in any equipment parts or waste water, including the sink in Ward E, but it was detected in the nutrient fluid for nasal feeding and in the line of one patient. The DNA homology of MDRPS isolated from the patient and the nutritive liquid was the same as that of some strains isolated in Ward E, as shown by random amplified DNA polymorphism PCR. In conclusion, we speculated that some nosocomial infections due to MDRPS resistant to imipenem were caused by contaminated nasal feeding.

Adolescent↗
PubMed1999

Multicenter study of paroxysmal dyskinesias in Japan--clinical and pedigree analysis.

To investigate the clinical features of paroxysmal dyskinesias and carry out a pedigree analysis, we conducted a multicenter survey in Japan. A questionnaire was mailed to 229 medical institutions. A total of 150 patients with paroxysmal kinesigenic choreoathetosis (PKC), including 53 sporadic cases and 97 affected individuals from 32 pedigrees, were identified. The mean age of onset of PKC was 8.8 years, and 80% of the cases were men. Of the 32 pedigrees with familial occurrence, 18 (56%) were compatible with an autosomal-dominant inheritance (AD) with complete penetrance, and seven (22%) had AD with incomplete penetrance; the remaining seven were sibling recurrence cases with apparently healthy parents. In six of seven familial cases with incomplete penetrance, the disease gene was thought to be transmitted by clinically unaffected females. Paroxysmal dystonic choreoathetosis (PDC) was found in five cases, including two sporadic cases and three affected individuals from two pedigrees; the mean age of onset was 0.6 years, and a male predominance was noted (male:female = 4:1). There was one case of paroxysmal hypnogenic dyskinesia and one case of paroxysmal exertion-induced dyskinesia. There is an unexplained male predominance for paroxysmal dyskinesias. When the genetic defect of patients with paroxysmal dyskinesias is identified, the pathophysiology of the disease will become more clear.

Adolescent↗
PubMed1999

Proposition for assessment of quantitative whole-body autoradiography.

To assess recent improvements in quantitative whole-body autoradioluminography (QWBA), the entire QWBA procedure was divided into five processes. Each process was then investigated carefully to determine whether there were any problems in defining a clear standard operating procedure. Results show that use of two instruments, Macro-Cut, Leica, Germany, and the Bioimaging Analyzer with IP, Fuji Photo Film, was essential to produce macroautoradiographs for QWBA data. The remaining problems include the process for freezing the animal carcass and the process for freeze-drying or lyophilizing the frozen sections of the biomaterials. In addition, a desirable standard operating procedure (SOP) must be developed for assessing QWBA. This article proposes satisfactory SOPs with sufficient clarification and experimental proofs to ensure regulatory compliance for the QWBA technique.

Animals↗
PubMed1999

Oxygen uptake efficiency slope as a useful measure of cardiorespiratory functional reserve in adult cardiac patients.

In this study we aimed to elucidate the validity and usefulness of the oxygen uptake efficiency slope (OUES) in the evaluation of adult cardiac patients. Cardiopulmonary exercise tests were performed on a treadmill by 50 adult patients with chronic heart failure. The OUES was calculated from data for the first 75%, 90%, and 100% of exercise duration. The OUES is derived from the following equation: VO(2)=ax logV(E)+b, where VO(2) is oxygen uptake (ml/kg/min), V(E) is minute ventilation (l/kg/min), and the constant "a" represents OUES. We also determined the ventilatory anaerobic threshold (VAT). The correlation coefficient of the logarithmic curve-fitting model was [mean (SD)] 0.986 (0.009). The OUES could be used to discriminate effectively between New York Heart Association functional classes (P < 0.001). OUES and maximum VO(2) were significantly correlated (r=0.78, P < 0.01). Agreement between the OUES values for the first 90%, 75%, and 100% of the exercise was excellent (intraclass correlation coefficient = 0.99). Our results suggest that OUES is applicable to adult cardiac patients as an objective, effort-independent estimation of cardiorespiratory functional reserve.

Aged↗