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Biomedical subjects

H Kobayashi

Publications and source records attributed to H Kobayashi.

At least 55 records · Page 3Linked to original sources
PubMed2005

Transplantation of corneal endothelium with Descemet's membrane using a hyroxyethyl methacrylate polymer as a carrier.

AIMS: To evaluate the histology and function of Descemet's membrane transplanted with intact endothelium. METHODS: Japanese white rabbits and human eyebank eyes were used as donors and recipients of Descemet's membrane transplantation. Donor endothelium was hydrodissected by injecting indocyanine green from a limbal incision, and then processed as a corneal scleral button. A 6 mm diameter donor sheet was trephined, and folded in half using a 6 mm diameter polymer as a carrier. Recipient endothelium was also hydrodissected from the limbus using trypan blue to stain the Descemet's membrane. Continuous curvilinear descemetorhexis (CCD) was performed to remove a circular section of the Descemet's membrane using a 27 gauge cystotome. Donor tissue was inserted into the anterior chamber through a 5 mm limbal incision and apposed to the host stroma. Polymers were removed following transplantation. Similar surgical procedures were performed in both rabbits and eyebank eyes. Haematoxylin eosin stains were performed after 28 days in rabbits, and eyebank eyes were fixed immediately following surgery for endothelial cell counts. RESULTS: Rabbit control eyes demonstrated stromal oedema caused by loss of Descemet's membrane, whereas transplanted eyes had clear corneas. The mean (standard deviation) pachymetry of operated eyes was 376.6 (SD 32.5) mum compared with 389.6 (SD 25.1) mum in the unoperated eye. Mean endothelial density immediately following surgery in eyebank eyes was 2749 (SD 288) cells/mm(2). CONCLUSIONS: Transplantation of Descemet's membrane by CCD produces a functional graft with an optically clear interface similar to control cornea.

Animals↗
PubMed2005

[Recurrent lung cancer with interstitial pneumonia treated with percutaneous radiofrequency ablation].

We performed computed tomography (CT)-guided percutaneous radiofrequency ablation (RFA) for postoperative recurrent pulmonary metastases developed in a 77-year-old man with interstitial pneumonia. He had received left upper segmentectomy with ND 2a nodal dissection. RFA was safely performed for pulmonary metastases in right S6 and left S6. There was no evidence to suggest any deterioration on interstitial pneumonia, including KL 6 and CT findings. Autopsy revealed residual cancer cells in peripheral lesion in 1 of 2 tumors treated by RFA. Although RFA is palliative, it is a promising treatment for local control of pulmonary malignancy in high-risk patients.

Aged↗
PubMed2005

[Hemothorax following intraabdominal bleeding due to pedicle torsion of ovarian tumor via a small pore in the diaphragm: report of a case].

On February 25, 2004, 59-year-old woman visited a local clinic due to lower abdominal pain. On February 28, she was admitted to the clinic due to severe abdominal pain. Computed tomography (CT) showed a mass in the lower abdomen and plural effusion and athelectasis of the right lung. She had severe anemia (Hb 6.9 g/dl). On March 1, she was transferred to our hospital. Pleural fluid was revealed to be sanguineous by thoracentasis. She underwent thoracotomy on the day of admission. There was no source of bleeding in the pleural space. A small pore, 3 mm in diameter, was found in the tendinous portion of the diaphragm. An influx of bloody fluid from the abdomen via the pore caused hemothorax. Laparotomy was performed, followed by closure of the pore using direct suture. The origin of the abdominal bleeding was pedicle torsion of the right ovarian tumor. Seven months after surgery she was uneventful with no pleural effusion.

Abdominal Cavity↗
PubMed2005

[Mature teratoma combined with schizophrenia: report of a case].

A 20-year-old woman was admitted to another hospital due to schizophrenia in July 2003. The patient felt chest pain and palpitation in August, and she was referred to our hospital. Chest computed tomography (CT) showed a mass in the left thoracic cavity and a pleural/pericardial effusion. Since general condition did not improved in spite of aggressive supportive treatment, surgical treatment was chosen. An operation was performed via median sternotomy in September. The tumor was found to have adhered firmly to the surrounding organs. Pericardial fenestration was performed; then the tumor was resected with the left phrenic nerve due to tight adhesion. The patient received respiratory support in the intensive care unit for 5 days after surgery, uneventfully. Twenty-three months after surgery, she is surviving and free from schizophrenic symptoms without medication.

Adult↗
PubMed2004

Adult-onset leukoencephalopathy with vanishing white matter with a missense mutation in EIF2B5.

We report of a woman aged 52 years born to consanguineous parents and seeking treatment for progressive dementia and delusion. Neurologic examination revealed dementia and emotional instability, indifference, and confabulation. There was also mild spasticity of the bilateral lower limbs. MRI revealed diffuse white matter hyperintensity on T2-weighted images accompanied by hypointense areas on fluid-attenuated inversion recovery images. A homozygous missense mutation was identified in EIF2B5.

Adult↗
PubMed2004

Intraspinal sarcoidosis: clinical features, MR imaging and electrophysiological study.

We presented the case of a 58-year-old woman with spinal sarcoidosis at the C4-C6 level. The lesion itself as visualized with magnetic resonance imaging, and its neurological findings responded favorably to treatment with prednisolone. Comparison of pre- and post-treatment values for somatosensory evoked potential (SEP) and central motor conduction time (CMCT) also showed improvement. Analysis of SEP and CMCT can be a useful tool for following up spinal sarcoidosis.

Cervical Vertebrae↗
PubMed2004

Neutron capture autoradiographic study of the biodistribution of 10B in tumor-bearing mice.

For the study on boron neutron capture therapy, the whole-body sections of tumor-bearing mice infused with 10B attached to CR-39 plastic track detectors were exposed to thermal and cold neutron beams. Neutron capture autoradiographic images obtained by the cold neutron irradiation were extremely superior in quality to those of the thermal neutron beams. From the autoradiographic images, the 10B reaction dose of the neutron-induced particles was estimated using the differential LET distribution.

Animals↗
PubMed2004

Polymerase chain reaction with a primer pair in the 16S-23S rRNA spacer region for detection of Mycoplasma pulmonis in clinical isolates.

To develop a diagnostic tool to identify Mycoplasma pulmonis (M. pulmonis) in clinical isolates, we developed a polymerase chain reaction (PCR) assay using primers specific for the 16S-23S rRNA intergenic spacer region (SR) of M. pulmonis. One pair of PCR primers reacted specifically with two reference strains of M. pulmonis tested and seven samples isolated from naturally infected rats. The primer pair did not produce PCR products of the correct size from any other rodent or human mycoplasmas or cellular DNA from rodent lungs. Specificity of the PCR assay was confirmed by Southern blotting with probe specific for the SR of M. pulmonis. The PCR assay for detection of M. pulmonis established in this study is suitable for diagnosis of M. pulmonis infection in clinical cases.

Animals↗
PubMed2004

Effects of atherosclerotic plaque on the enlargement of an experimental model of abdominal aortic aneurysm in rabbits.

PURPOSE: Abdominal aortic aneurysm (AAA) usually is associated with atherosclerosis. We attempted to create an abdominal aortic aneurysm with atherosclerotic plaque in rabbits to investigate the relationship between atherosclerosis and enlargement of AAA. METHODS: An isolated segment of rabbit abdominal aorta was perfused with pancreatic elastase. Animals were fed a cholesterol-enriched diet to induce atherosclerotic plaque formation. Eight animals received perfusion with elastase and were fed a cholesterol-enriched diet (group EC), eight animals received perfusion with elastase and were fed a normal diet (group EN), eight animals received perfusion with saline and were fed a cholesterol-enriched diet (group SC), and eight animals received perfusion with saline and were fed a normal diet (group SN). Four animals served as a sham group. Each animal was killed after aortography at 4 or 12 weeks. The perfused segment was excised and examined histologically. RESULTS: No animal treated with saline and fed normal diet (groups SN) developed either an aneurysm or atherosclerosis. Atherosclerotic plaque was observed in animals fed the cholesterol-enriched diet (groups SC and EC) at 4 weeks, and the plaque had thickened further by 12 weeks. All animals treated with elastase (groups EN and EC) developed an AAA. Maximum internal diameter in groups EN and EC (4.1 mm) was equal at 4 weeks, but at 12 weeks, the diameter was less for group EC than for group EN (4.0 mm versus 4.8 mm, P<0.05). CONCLUSION: Cholesterol-enriched diet following the intra-luminal perfusion of an isolated aortic segment with elastase produced an AAA with atherosclerotic plaque in rabbits. It is likely that the thickened intima with atheroma suppressed continued enlargement of the aneurysm in this model.

Animals↗
PubMed2004

Expression of adrenomedullin and proadrenomedullin N-terminal 20 peptide in PC12 cells after exposure to nerve growth factor.

Adrenomedullin (AM) and proadrenomedullin N-terminal 20 peptide (PAMP) are multi-functional peptides derived from the same precursor, proadrenomedullin. We have studied the regulatory mechanism of expression of these peptides during neuronal differentiation of rat pheochromocytoma PC12 cells by nerve growth factor (NGF). The cellular levels of the peptides increased slightly, and then progressively decreased below the control by NGF. Immunoreactive (ir)-AM in the medium was transiently increased by NGF. Cytochemical staining showed that ir-AM and ir-PAMP were abundantly present in cytoplasm in the undifferentiated cells, and were decreased during culture with NGF. There was no preferential localization of ir-AM or ir-PAMP in neurites in comparison with in cytoplasm in the differentiated cells. Northern blot analysis showed that mRNA encoding these peptides, as detected as a band of 1.6 kb, increased more than three-fold at 1 h after the addition of NGF and then progressively decreased to one fifth of the control during 72 h. Degradation rate of the mRNA was slowed by NGF even when mRNA level is decreased after 72 h of NGF treatment. The transcription rate of their gene increased transiently and then decreased by the long-term treatment with NGF. These results demonstrate that expression of AM and PAMP is regulated by NGF along with time-dependent differentiation: AM gene transcription is transiently activated by NGF, whereas it was suppressed during neuronal differentiation of the cells.

Adrenomedullin↗
PubMed2004

Functional properties of the surface of the vermilion border of the lips are distinct from those of the facial skin.

BACKGROUND: The vermilion border of the lips (lip for short) is the only part on the face where the oral mucosa is persistently exposed to the outside. Despite its prominent presence on the face, constituting not only the target of cosmetics but also the site for various skin diseases, its functional properties remain almost unknown. OBJECTIVES: To elucidate the functional properties of the vermilion border of the lips. METHODS: We studied the biophysical properties of the lip by comparing them with those of the cheek skin in 303 healthy Japanese females aged 21-80 years, in winter. We used a closed-chamber system to measure transepithelial water loss (TEWL) of the lip to avoid the effect of breathing. Moreover, we examined the effects of oral etretinate, a drug that definitely produces dry, scaly lips, on the lips of seven male patients aged 49-89 (average 67) years. RESULTS: TEWL was significantly almost three times as high on the lips as that on the cheek which is a site that shows far higher levels than do other body areas. TEWL decreased with age more remarkably on the lip than on the cheek. High-frequency conductance, a parameter for surface hydration state, was significantly lower on the lip than on the cheek. The mean values obtained were about one-third of those on the cheek, and no age-related changes were observed either on the lip or on the cheek. The superficial epithelial cells on the lip were parakeratotic and larger than those of the cheek skin. Furthermore, we detected a significant increase in TEWL on the lip as well as on the cheek of patients treated with oral etretinate. CONCLUSIONS: It appears that the incomplete corneocyte formation of the lip surface is responsible for the poor barrier function and water-holding capacity.

Administration, Oral↗
PubMed2004

Pharmacokinetics and pharmacodynamics of febuxostat (TMX-67), a non-purine selective inhibitor of xanthine oxidase/xanthine dehydrogenase (NPSIXO) in patients with gout and/or hyperuricemia.

The diurnal change of sUA and the effect of febuxostat on this change were investigated in 10 patients with gout and/or hyperuricemia. The diurnal sUA change after the last dose during the 4-week treatment phase (20 mg, QD) was almost the same as the pre-treatment value. Considering the dose, the AUC(obs) and Cmax of unchanged drug in patients with gout and/or hyperuricemia were estimated to be similar to those of healthy male adults. The results show that a 6-week treatment with febuxostat is safe and well-tolerated in the target patient population for this drug.

Area Under Curve↗
PubMed2004

The tetraspanin CD9 is preferentially expressed on the human CD4(+)CD45RA+ naive T cell population and is involved in T cell activation.

Human CD4+ T cells can be divided into reciprocal memory and naive T cell subsets based on their expression of CD45 isoforms and CD29/integrin beta1 subunit. To identify unique cell surface molecules on human T cells, we developed a new monoclonal antibody termed anti5H9. Binding of anti5H9 triggers a co-stimulatory response in human peripheral blood T cells. Retrovirus-mediated expression cloning has revealed that the antigen recognized by anti5H9 is identical to the tetraspanin CD9. We now show that human CD9 is preferentially expressed on the CD4(+)CD45RA+ naive T cell subset, and that CD9(+)CD45RA+ T cells respond preferentially to the recombinant beta2-glycoprotein I, compared to CD9-CD45RA+ T cells. Furthermore, anti5H9 inhibits both the recombinant beta2-glycoprotein I- and the recall antigen tetanus toxoid-specific T cell proliferation. These results suggest that the tetraspanin CD9 plays an important role in T cell activation.

Animals↗
PubMed2004

Chemical induction of HO-1 suppresses lupus nephritis by reducing local iNOS expression and synthesis of anti-dsDNA antibody.

There is accumulating evidence that haem oxygenase (HO)-1 plays a protective role in various disorders. The beneficial efficacy of HO-1 induction therapy has been shown in renal diseases such as glomerulonephritis, interstitial nephritis and drug induced nephrotoxicity. However, involvement of HO-1 in the development of autoimmune renal diseases remains uncertain. To assess the clinical efficacy of HO-1 induction therapy for lupus glomerulonephritis, MRL/lpr mice were intraperitoneally injected with 100 micromol/kg hemin, a potent HO-1 inducer, or PBS as controls, once a week from 6 weeks of age to 21-24 weeks-old. We found that treatment with hemin led to a significant reduction of proteinuria and remarkable amelioration of glomerular lesions accompanied by decreased immune depositions. In addition, the circulating IgG anti-double-stranded DNA antibody level was significantly decreased in hemin treated mice when compared with controls. A single intraperitoneal injection with hemin resulted in reduction of inducible nitric oxide synthase expression in the kidney and spleen, and serum interferon-gamma level. Our results suggest that HO-1 induction therapy ameliorates lupus nephritis by suppressing nitric oxide (NO) dependent inflammatory responses and attenuating production of pathogenic autoantibodies.

Animals↗
PubMed2004

Ghrelin-induced growth hormone release from isolated rat anterior pituitary cells depends on intracellullar and extracellular Ca2+ sources.

Ghrelin, a novel growth hormone (GH)-releasing peptide, was isolated from the rat stomach as an endogenous ligand to the growth hormone secretagogues receptor. It is known that ghrelin stimulates the release of GH from the rat anterior pituitary gland, but the intracellular signal cascade in somatotrophs has not yet been clarified. In this study, using an isolated cell perifusion system, we examined whether ghrelin- and growth hormone-releasing hormone (GHRH)-induced GH secretion from rat pituitary cells depends on intra- and extracellular Ca(2+) and voltage-gated Ca(2+) channels. For this purpose, we first measured ghrelin- or GHRH-stimulated GH concentration following treatment with reduced extracellular Ca(2+) and/or thapsigargin, an endoplasmic reticulum Ca(2+) ATPase inhibitor. Reductions in the extracellular Ca(2+) concentration to 0.25 mM and to 0 mM resulted in decreases in ghrelin-stimulated GH secretion to 81% and 39% and decreases in GHRH-induced GH secretion to 83% and 13%, respectively, compared to the levels in the case of 2.5 mM Ca(2+) concentration, suggesting that extracellular Ca(2+) is essential for both ghrelin- and GHRH-induced GH secretion. Pretreatment with thapsigargin resulted in a reduction in ghrelin-induced GH secretion to approximately 60% of the control level, but GHRH treatment had not effect on the GH secretion. Moreover, preincubation with thapsigargin and 0 mM extracellular Ca(2+) concentration resulted in significant inhibition of GHRH- and ghrelin-induced GH secretion. Subsequently, to determine whether ghrelin-stimulated GH secretion was induced through voltage-gated Ca(2+) channels, we measured the ghrelin-stimulated GH concentration following treatment with nifedipine, an L-type Ca(2+) channel inhibitor, and found that the amount of GH secretion was reduced to 44% of the control level. Furthermore, by replacement of extracellular Na(2+) in the medium with N-methyl-D(-)-glucamine, an impermeable molecule, GH secretion was reduced to 47%. In this study, we demonstrated that the GH-stimulatory effect of ghrelin, unlike that of GHRH, is achieved through both intracellular and extracellular Ca(2+) sources and that ghrelin-induced extracellular Ca(2+) influx involves an L-type voltage-gated Ca(2+) channel and Na(+) influx.

Animals↗