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Biomedical subjects

K Henmi

Publications and source records attributed to K Henmi.

At least 19 recordsLinked to original sources
PubMed2001

A possible role of glutathione and glutathione disulfide in tracheary element differentiation in the cultured mesophyll cells of Zinnia elegans.

We investigated the relationship between the cellular redox state of GSH or GSSG and tracheary element (TE) differentiation using a Zinnia experimental system, in which isolated mesophyll cells transdifferentiate to TEs. TE differentiation was suppressed by the application of L-buthionine sulfoximine (BSO), a potent inhibitor of GSH biosynthesis, at the early stage of cell culture. Application of GSSG at the early culture stage promoted the differentiation, but that of GSH or GSSG at an advanced period of culture suppressed the differentiation. Application of GSH and GSSG nullified the TE differentiation-suppressing effect of BSO. The results suggest that changes in the redox states of GSH and GSSG have a role in TE differentiation.

Asteraceae↗
PubMed2000

Synthesis, solid-state structures, and aggregation motifs of phosphines and phosphine oxides bearing one 2-pyridone ring

Three phosphines and their corresponding oxides bearing one 2-pyridone ring and two benzene rings were synthesized. Their single-crystal X-ray analyses exhibited three kinds of molecular aggregation: bimolecular aggregates, chiral one-dimensional structures, and achiral one-dimensional structures. In the bimolecular aggregate of (2-oxo-1, 2-dihydro-x-pyridyl)diphenylphosphines (x = 3: 2a and 6: 2c), cyclic dimers that are derived from two 2-pyridone rings are observed. In contrast, (2-oxo-1,2-dihydro-5-pyridyl)diphenylphosphine (2b) molecules form a chiral one-dimensional chain via intermolecular hydrogen bonding. In the case of phosphine oxides, their oxygen always acts as a hydrogen acceptor of the hydrogen bonding. Thus, (2-oxo-1,2-dihydro-x-pyridyl)diphenylphosphine oxides (x = 3: 3a and 5: 3b) form hydrogen bonds intermolecularly between the oxygen atom on the phosphoryl group and the hydrogen atom on nitrogen to construct a chiral or an achiral one-dimensional chain. Interestingly, (2-oxo-1,2-dihydro-6-pyridyl)diphenylphosphine oxide (3c) exists as a 2-hydroxypyridine form (enol form) in a crystalline state, and intermolecular hydrogen bonds between the phosphoryl oxygen and the hydroxy proton construct an achiral one-dimensional chain.

Journal Article↗
PubMed1999

The small GTP-binding protein rac is a regulator of cell death in plants.

Cell death plays important roles in the development and defense of plants as in other multicellular organisms. Rapid production of reactive oxygen species often is associated with plant defense against pathogens, but their molecular mechanisms are not known. We introduced the constitutively active and the dominant negative forms of the small GTP-binding protein OsRac1, a rice homolog of human Rac, into the wild type and a lesion mimic mutant of rice and analyzed H(2)O(2) production and cell death in transformed cell cultures and plants. The results indicate that Rac is a regulator of reactive oxygen species production as well as cell death in rice.

Amino Acid Sequence↗
PubMed1999

Lesion mimic mutants of rice with alterations in early signaling events of defense.

We screened 93 lesion mimic mutants of rice for resistance to the blast fungus, Magnaporthe grisea, and found eight mutants that exhibited significant resistance to the fungus. We called these mutants cdr (cell death and resistance) and further analyzed three of them. Two mutations, cdr1 and cdr2, were recessive and one, Cdr3, was dominant. Many small brownish lesions developed over the entire leaf of the mutants 20-50 days after sowing. TUNEL staining revealed that DNA fragmentation occurred in leaf blade cells of the homozygous Cdr3 mutants. Autofluorescence and callose deposition were visible in leaf cells of these three mutants. Activation of two defense-related genes, PBZ1 and PR1, was observed in the leaves of the mutants; high expression of PBZ1 was correlated with the lesion formation in the three mutants, whereas PR1 was constitutively expressed in the cdr2 and Cdr3 mutants irrespective of the lesion formation. Levels of momilactone A, a major phytoalexin of rice, in these mutants were increased approximately 100-400-fold relative to the wild-type levels. Suspension-cultured cells of the cdr1 and cdr2 but not Cdr3 produced higher levels of H2O2 than the wild type when treated with calyculin A, an inhibitor of protein phosphatase 1. These results suggest that biochemical lesions of cdr1 and cdr2 lie in the early signaling steps leading to activation of the NADPH oxidase and that type-1 protein phosphatase is operative in protein dephosphorylation involved in NADPH oxidase activation.

DNA Fragmentation↗
PubMed1998

Acute retinal necrosis late in the second trimester.

PURPOSE: To report treatment of a patient with acute retinal necrosis during pregnancy. METHODS: A 24-year-old woman in her twenty-third week of gestation was diagnosed with acute retinal necrosis. A combination of acyclovir and interferon therapy was started at 25 weeks. Pars plana vitrectomy was performed during the 26th week of gestation. RESULTS: The necrotizing retina became gliotic within 3 weeks of surgery. The patient's visual acuity improved to LE, 20/40. A healthy baby was delivered at 39 weeks of gestation. CONCLUSION: Combination therapy of acyclovir and interferon followed by surgery partially restored the patient's vision without affecting fetal development.

Acyclovir↗
PubMed1995

[A case of primary pulmonary B cell lymphoma confirmed by gene analysis].

A 76-year-old man visited our clinic with chest radiographic evidence of a coin lesion in the right middle lung. Chest CT demonstrated an infiltrative shadow mainly in the S4 segment. Lymphoproliferative disorders were suggested by transbronchial lung biopsy. Middle lobectomy was performed. Pathological study showed massive proliferation of mature lymphocytes. Immunoperoxidase studies could not demonstrate a neoplastic monoclonal process. Pseudolymphoma was diagnosed. High molecular weight DNAs were extracted from frozen specimens. Whether genes of immunoglobulins and T-cell receptors were rearranged was investigated using DNA probes against JH and TCR beta-1 receptor gene. One rearranged band was found in the JH chain. No rearranged band appeared in TCR beta-1 chain. B cell lymphoma was diagnosed instead of pseudolymphoma.

Aged↗
PubMed1992

[Observation of the posterior urethra by transrectal linear ultrasonography].

Transrectal linear ultrasonography was performed on 59 male patients with dysuria, and voiding movement of the posterior urethra was observed with a videomonitor. Uroflowmetry was performed simultaneously, and the results were compared with those obtained in a previous study. On the image synchronized with maximum flow rate, the diameter of the bladder neck, and the center of the prostatic urethra were measured as parameters and the correlation with maximum flow rate, average flow rate, and residual urine rate, was examined. The forward movement of the ventral side of the posterior urethra was found to play a more important role in the opening of the posterior urethra, than the opening of the bladder neck, and the width of the prostatic urethra to play a more important role in the efficiency of urination than the width of the bladder neck.

Adult↗
PubMed1991

[A case of pathological dilation of seminal vesicle with high level of serum CA-19-9].

A case of pathological dilation of seminal vesicle is presented. A 18-year-old male was admitted to our hospital with the complaints of gross hematuria and discomfort of the scrotum. IVP and abdominal CT scan revealed the left aplastic kidney, and ultrasound, vesiculography, and pelvic CT scan revealed markedly dilated bilateral seminal vesicles without filling defects. The level of serum CA19-9 was 390 u/ml, which was extremely high. After resection of dilated seminal vesicles, it returned to the normal range (37 u/ml). Sixty six cases of pathological dilation of seminal vesicle were collected from the Japanese literature. No cases showing a high level of serum CA19-9 have been reported in Japan.

Adolescent↗
PubMed1989

[A case of mediastinal neurilemmoma diagnosed by X-ray guided needle biopsy].

A 70-year-old female was admitted to our hospital complaining of general lassitude. She had been treated for duodenal ulcer. A routine chest X-ray film at admission showed a large tumorous shadow in the right apical field. A computed tomographic scan revealed that it was a posterior mediastinal tumor containing multiple cystic lesions. After medical treatment for duodenal ulcer, a needle biopsy was performed for histological diagnosis. Under local anesthesia a small skin incision was made in the supraclavicular region to avoid parietal pleura and great vessels and a specimen was obtained by a needle guided by X-ray fluoroscopy. The tumor was diagnosed as neurilemmoma histologically. She was discharged because the complaint subsided. Five months later, however, she was again admitted complaining of righ nuchal pain. Thoracotomy was performed under general anesthesia and the tumor growing from the second intercostal nerve was resected. It was 5 x 4 x 5.5 cm in size, encapsulated and consisted of multiple cystic lesions macroscopically. It was confirmed as Antoni B type neurilemmoma histologically. The nuchal pain subsided and she has been doing well for more than three years after discharge. Recently computed tomography (CT) and ultrasonography (US) have been widely used as a guiding device for needle biopsy. In this case, however, CT guided needle biopsy was not applied for fear of possible complications such as pneumothorax. It was also impossible to perform US guided needle biopsy because the tumor was behind the costal and sternal bones and could not be visualized.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1989

[Single-daily-dose treatment of ceftriaxone for biliary tract infections and bacterial counts in bile].

To evaluate the effects of ceftriaxone (CTRX) administered once daily, the biliary concentration of CTRX and daily changes in the bacterial count in bile from an indwelling T-tube were measured concomitantly. The effects on prophylaxis of postoperative infections after biliary tract surgery were also examined mainly due to clinical symptoms. The biliary CTRX levels increased rapidly and were sustained as high as 92.5-219 micrograms/ml in all patients even 24 hours after 2 g of CTRX was infused intravenously once daily. Five of 7 patients whose bile samples were positive for bacteria showed high CTRX levels in bile and almost no bacteria present after treatment. CTRX-sensitive bacteria eliminated 1 or 2 hours after the administration in response to the increase of biliary CTRX levels. The changes in bacteria count of bile may be closely related to CTRX antibiotic activity. As an antibiotic prophylaxis, other 18 patients with biliary diseases received intravenous infusion of 2 g of CTRX once daily for 5-7 days (mean 5.9 days). Thus, once-daily dose treatment of CTRX 2 g may have antibiotic effects on biliary infection and postoperative prophylaxis of biliary infections and it is indicated that the prolonged biliary levels of CTRX are essential for its efficacy.

Adult↗