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Biomedical subjects

Y Yamashiro

Publications and source records attributed to Y Yamashiro.

At least 55 records · Page 3Linked to original sources

Renal amyloidosis in recessive dystrophic epidermolysis bullosa.

BACKGROUND: Although it is known that renal amyloidosis may complicate several dermatoses, recessive dystrophic epidermolysis bullosa (RDEB) complicated by nephropathy has been thought to be rare. We, however, had seen a young adult with RDEB who died of renal failure due to systemic amyloidosis. OBJECTIVE: A retrospective study was performed in order to investigate the incidence and etiology of renal amyloidosis in RDEB. METHODS: Routine urinalysis, serum amyloid A protein (SAA) and creatinine levels were repeatedly determined in 11 patients with RDEB (mean age 17.7 years, range 5-28, 7 males, 4 females). Nephropathy was defined as the presence of both proteinuria and hematuria with red blood cell casts. RESULTS: Seven out of 9 generalized RDEB patients had nephropathy including 3 cases with end-stage renal disease (2 died within 2 years from the onset of nephropathy), while 2 patients with localized RDEB did not. Levels of SAA were significantly higher in patients with nephropathy than those in patients without nephropathy (p<0.05). CONCLUSION: Nephropathy is a common and serious complication of RDEB. Renal amyloidosis may play an important role in its etiology. We recommend that patients with RDEB should be periodically screened for nephropathy due to amyloidosis by urinalysis and measuring SAA levels.

Adolescent↗

[In vitro interaction of piperacillin and imipenem/cilastatin combined with aminoglycosides against Pseudomonas aeruginosa].

The in vitro interactions of piperacillin (PIPC) and imipenem/cilastatin (IPM/CS) combined with 5 kinds of aminoglycosides (gentamicin, tobramycin, amikacin (AMK), isepamicin and netilmicin) were investigated against IPM/CS-susceptible (MIC of IPM/CS was < or = 3.13 micrograms/ml) and IPM/CS-resistant (MIC of IPM/CS was > or = 12.5 micrograms/ml) Pseudomonas aeruginosa. The following results were obtained. 1. In the checkerboard dilution studies, the combinations of PIPC with aminoglycosides showed synergistic effect for more than 50% of the each 54 strains of IPM/CS-susceptible and IPM/CS-resistant P. aeruginosa. The synergistic/additive effects of PIPC with aminoglycosides were demonstrated for all tested strains. 2. In the checkerboard dilution studies, the combinations of IPM/CS with aminoglycosides showed no antagonism against any strains. The synergistic effects of IPM/CS with aminoglycosides were demonstrated for 0 to 14.8%, and these values were smaller than the combinations of PIPC with aminoglycosides. 3. Corresponding to the results of checkerboard dilution studies, the combination of PIPC with AMK was more effective than the combination of IPM/CS with AMK on the killing curve for IPM-resistant P. aeruginosa. In conclusion, PIPC showed the synergistic effects in combinations with aminoglycosides against IPM/CS-resistant P. aeruginosa. These results suggest that the combination therapies of PIPC with aminoglycosides are useful for the clinical treatment of serious infections due to P. aeruginosa.

Amikacin↗

[Usefulness of arousals for the detection of sleep breathing disorder].

Because of the difference of sensitivity among measurement techniques, upper airway obstruction events cannot always be scored as apnea or hypopnea. We hypothesized that arousal accompanied with breathing disturbance is a more sensitive index for the diagnosis of sleep breathing disorders than others. We studied 75 patients with sleep breathing disorder by polysomnograph. Breathing disturbance related arousal (B-Ar) was defined as an arousal accompanied with at least one of the following (apnea, hypopnea, more than 4% oxygen desaturation, snoring), and the breathing disturbance indices were compared. There were close relationships between B-ArI and apnea hypopnea index (AHI), oxygen desaturation index (DI), and percent of total sleep time with SpO2 below 90% in all patients (r = 0.93, r = 0.58, r = 0.92, respectively, all p < 0.001). In 25 patients whose AHI was below 20 per hour, no relationship between B-ArI and AHI was found, and B-ArI was significantly greater than AHI. Thus, B-ArI seemed to be more sensitive than AHI. In all 6 patients whose AHI was below 10, B-ArI was lowered decreased by continuous nasal positive airway pressure therapy. These results suggest that B-ArI may be more sensitive in the detection of sleep breathing disorders than the other indices when AHI is below 20 per hour.

Adult↗

Regulation of NeuroD expression by activation of the protein kinase-C pathway in Y79 human retinoblastoma cells.

To examine the signals that regulate NeuroD expression, we analyzed the effects of activation of two major signal pathways, the protein kinase A (PKA) pathway and the protein kinase C (PKC) pathway, on the expression of NeuroD in Y79human retinoblastoma cells. Activation of PKC resulted in marked induction of NeuroD mRNA and NeuroD protein. NeuroD mRNA induction was inhibited by calphostin C, an inhibitor of PKC. On the other hand, stimulation of PKA by forskolin had a weak suppressive effect on NeuroD mRNA expression. Induction of NeuroD expression was followed by enhancement of expression of the AK1 gene, one of the target genes of NeuroD, which encodes adenylate kinase isozyme 1, an important enzyme in the cellular adenine nucleotide homeostasis. Our results indicate that NeuroD expression is regulated, at least in part, by the PKC pathway and not by the PKA pathway.

Adenylate Kinase↗

Tachycardia as a potential risk indicator for coronary arterial lesions in Kawasaki disease.

UNLABELLED: Tachycardia is frequently observed in the acute phase of Kawasaki Disease (KD) patients. However, little is known about the association between the tachycardia in the acute phase of KD and the development of coronary arterial lesions (CAL). We examined the association between the mean 24 h heart rate in the acute phase of KD observed using 24 h ambulatory ECG monitoring (24 h-ECG) and the occurrence of CAL in patients. In a study conducted between 1994 and 1997, 26 patients with KD underwent 24 h-ECG within the febrile period and before the 9th day of illness. We compared the mean 24 h heart rate based on 24 h-ECG between patients with and those without CAL. Of 26 patients, 7 had CAL. The groups with and without CAL had similar baseline characteristics. The mean 24 h heart rate in the group with CAL was significantly higher than that in the group without CAL (144 +/- 14 vs. 124 +/- 22, P = 0.033). On multiple regression analysis, the mean 24 h heart rate was significantly correlated with the development of CAL (P = 0.019). CONCLUSION: Marked tachycardia detected by 24 h-ambulatory ECG monitoring in the acute phase of Kawasaki disease might provide important information on the development of coronary arterial lesions.

Acute Disease↗

In vitro and in vivo antimicrobial activities of T-3811ME, a novel des-F(6)-quinolone.

The in vitro and in vivo activities of T-3811ME, a novel des-F(6)-quinolone, were evaluated in comparison with those of some fluoroquinolones, including a newly developed one, trovafloxacin. T-3811, a free base of T-3811ME, showed a wide range of antimicrobial spectra, including activities against Chlamydia trachomatis, Mycoplasma pneumoniae, and Mycobacterium tuberculosis. In particular, T-3811 exhibited potent activity against various gram-positive cocci, with MICs at which 90% of the isolates are inhibited (MIC90s) of 0.025 to 6.25 microgram/ml. T-3811 was the most active agent against methicillin-resistant Staphylococcus aureus and streptococci, including penicillin-resistant Streptococcus pneumoniae (PRSP). T-3811 also showed potent activity against quinolone-resistant gram-positive cocci with GyrA and ParC (GrlA) mutations. The activity of T-3811 against members of the family Enterobacteriaceae and nonfermentative gram-negative rods was comparable to that of trovafloxacin. In common with other fluoroquinolones, T-3811 was highly active against Haemophilus influenzae, Moraxella catarrhalis, and Legionella sp., with MIC90s of 0.0125 to 0.1 microgram/ml. T-3811 showed a potent activity against anaerobic bacteria, such as Bacteroides fragilis and Clostridium difficile. T-3811 was the most active agent against C. trachomatis (MIC, 0.008 microgram/ml) and M. pneumoniae (MIC90, 0.0313 microgram/ml). The activity of T-3811 against M. tuberculosis (MIC90, 0.0625 microgram/ml) was potent and superior to that of trovafloxacin. In experimental systemic infection with a GrlA mutant of S. aureus and experimental pneumonia with PRSP in mice, T-3811ME showed excellent therapeutic efficacy in oral and subcutaneous administrations.

Administration, Oral↗

Induction of anaphylaxis in mouse intestine by orally administered antigen and its prevention with soluble high affinity receptor for IgE.

Early symptoms of food allergy, including diarrhea, are caused by IgE-mediated anaphylactic reactions. To clarify the mechanisms of IgE-mediated anaphylactic reactions in the intestine induced by orally administered antigen, a mouse model was established by s.c. implantation of a murine hybridoma capable of producing monoclonal anti-trinitrophenyl IgE antibody. Morphologic and immunologic changes in the intestine, as well as the effect of the soluble high affinity IgE receptor alpha chain, were investigated after oral challenge with antigen in this mouse model. Diarrhea, a decrease in s.c. blood flow, an increase in vascular permeability, a substantial increase in serum histamine levels, and noticeable infiltration of mast cells and IgE-bearing cells into the lamina propria were observed around 30 min after antigen challenge. However, these changes were efficiently prevented by pretreatment of the mice with the soluble high affinity IgE receptor alpha chain. These findings suggested that oral administration of antigen actually induced anaphylactic shock in our mouse model. This reaction was most likely to be mediated by mast cell activation, in response to the IgE-antigen complex, and a soluble form of the high-affinity IgE receptor efficiently prevented this IgE-mediated anaphylactic reaction by trapping free IgE.

Administration, Oral↗