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Biomedical subjects

K Hanada

Publications and source records attributed to K Hanada.

389 records · Page 22Linked to original sources
PubMedDate not supplied

Immunocytochemical demonstration of beta 1-subunit of Na+/K(+)-ATPase in the mechanoreceptive Ruffini-like endings of the rat incisor ligament.

The localization of one of the isoforms of Na+/K(+)-ATPase, the beta 1-subunit, was investigated in the periodontal Ruffini endings of rat incisors by light- and electron-microscopic immunocytochemistry. Immunoreactivity for the rat beta 1-subunit followed the pattern of dendritic terminal arborization in the alveolar half of the lingual periodontal ligament. Ultrastructurally, the reaction products were localized in dilatations of axons, possibly the terminals of Ruffini-like endings in the periodontal ligament. No immunoreactivity was seen in Schwann cells. The immunostaining results support the view that the beta 1-subunit of Na+/K(+)-ATPase is the predominant isoform in sensory neurones, and that this protein is a useful marker for periodontal Ruffini-like endings.

Alveolar Process↗
PubMedDate not supplied

Immune abnormality in relation to nonimmune diseases in SAM mice.

A series of related strains of senescence-accelerated mouse (SAM) shows strain-unique age-related diseases, such as amyloidosis, deficit in learning and memory, osteoporosis, and brain atrophy, while many of these disease-prone mouse (SAMP) strains have impaired immune activity as young adults, and have a short life span, probably not due directly to the diseases. Because the mean life span was prolonged and the time of the disease onset was delayed by a low-calorie dietary condition or a specific pathogen-free environment, both of which ameliorate the impaired immune activity, the enhancement of immune activity may help decrease the deteriorative process of aging, to that seen in ordinary strains of mice. Studies using the SAMP model may help elucidate the role of immunity in the aging process. Herein, we review the cellular and genetic basis of the immune abnormality in SAMP mice, then discuss the relationship between immune abnormality and development of the age-related disease, senile amyloidosis, findings obtained on SAMP hybrid mice and congenic mice for disease-related genes. Activation of the gene(s) for senile amyloid per se shortened the life span, and the early development of the immune dysfunction primarily seems to be both genetically and physiologically independent of amyloidosis, although the disease may be indirectly modified in the aged with depressed immune activity.

Aging↗
PubMedDate not supplied

In vivo gene transfer method in keratinocyte gene therapy: intradermal injection of DNA complexed with high mobility group-1 protein in rats.

In order to develop a more efficient method of introducing genes into keratinocytes in vivo, we intradermally injected DNA bound to high mobility group 1 protein, thereby taking advantages of the naked DNA and hemagglutinating virus of the Japan-liposome method reported previously. First we performed a gel mobility shift assay, which confirmed DNA binding to high mobility group 1. Then we injected beta-galactosidase expression vector complexed with high mobility group 1 into the rat skin and the activity of sample with the protein was 2-3 times higher than that without the protein as control. Semiquantification of transferred-DNA content using polymerase chain reaction and a time course of transgene expression in keratinocytes suggested that high mobility group 1 protein increased transfer of the DNA from the cytoplasm to the nucleus. Direct injection of the DNA-high-mobility-group-1 complex is a highly efficient method for introducing genes into keratinocytes in connection with gene therapy.

Animals↗
PubMedDate not supplied

Renal arteriovenous malformations: CT features.

The CT and clinical features of six patients with congenital renal arteriovenous malformation (RAVM) were reviewed to determine the characteristics of this condition. The most common symptom was hematuria. The CT images were characterized by masses of vascular density located in the renal sinus and surrounding the pelvicaliceal system with or without dilated renal veins. The exact size of the RAVM and the relation to the pelvicaliceal system were well demonstrated by delayed images or drip infusion technique, whereas the bolus injection technique was essential to document the vascular nature. The potential pitfalls in diagnosis that can occur if only an infusion study is performed are discussed.

Adult↗
PubMedDate not supplied

MRI of groove pancreatitis.

PURPOSE: The purpose of this work is to describe the findings on MRI in patients with groove pancreatitis, a specific form of chronic pancreatitis affecting the groove between the pancreatic head, the duodenum, and the common bile duct. METHOD: MR images, including MR cholangiopancreatography, of five patients with groove pancreatitis were reviewed. Three patients underwent pancreatoduodenectomy due to serve duodenal stenosis, and the MR findings were compared to the histologic findings. RESULTS: A sheet-like mass was demonstrated between the pancreatic head and the duodenum in all patients. The masses were hypointense relative to pancreatic parenchyma on T1-weighted images and iso- to slightly hyperintense on T2-weighted images. After administration of Gd-DTPA, the masses showed delayed enhancement. Histologically, fibrous scar tissue was detected in the groove. CONCLUSION: MR images can clearly demonstrate the fibrous tissue in the groove in groove pancreatitis, and MR cholangiopancreatography can also provide useful information.

Adult↗
PubMedDate not supplied

In vitro and in vivo antibacterial activity and pharmacokinetics of SC-002 and its derivative, SC-004: new oral cephalosporins.

SC-002 is a novel oral cephalosporin possessing a unique thiadiazolylethenyl moiety at the 3 position. In the present study, it was the most active against gram-positive bacteria among oral cephalosporins such as cefdinir (CFDN), cefpodoxime, cefditoren and cefaclor (CCL). It was equal to or 16 times more active than CFDN against standard and clinical strains. In particular, against clinical isolates of Morganella morganii and Haemophilus influenzae, SC-002 was 8-64 times more active than CFDN. The antibacterial activity of SC-002 against some beta-lactam-resistant strains was superior to that of CFDN. The in vivo antibacterial activity of SC-004, a pivaloyloxymethyl ester of SC-002, was 1.2-8 times more protective against systemic infections due to Streptococcus pneumoniae, Escherichia coli and Klebsiella pneumoniae than that of CFDN. The therapeutic effects of SC-004 on experimental respiratory tract infections caused by S. pneumoniae or H. influenzae were superior to those of CFDN and CCL. SC-004 showed higher and longer-lasting blood levels and higher urinary excretion in pharmacokinetics in mice.

Administration, Oral↗
PubMedDate not supplied

Possible role of cutaneous metallothionein in protection against photo-oxidative stress--epidermal localization and scavenging activity for superoxide and hydroxyl radicals.

It is reported that increasing metallothionein (MT) synthesis suppressed sunburn cell formation in the mouse skin after ultraviolet B (UVB) irradiation, implying a photo-protective effect of the cysteine-rich protein. To understand the mechanism of the defense by cutaneous MT against UVB injury, an immunohistological localization of MT in human normal skin was studied following examination of lesional skin. MT in the skin was localized in granular layer with diffuse staining pattern in normal skin, defect in psoriatic lesions, positive but thin in granular cells in the lesions of lichen planus. MT treatment showed a significant decrease in chemiluminescence induced by superoxide radicals and depressed signal intensity of hydroxyl radicals derived from the Fenton reaction system. From the viewpoint of characteristic localization and probable role in scavenging activity for reactive oxygen species, MT in the epidermis may contribute to the protection against phototoxic injury in association with enzymatic and non-enzymatic antioxidants. These findings may support the previous results of UV defense by cadmium-induced MT in the skin.

Animals↗
PubMedDate not supplied

Computed tomography and histologic appearance of pancreatic metastases from distant sources.

The computed tomographic and histologic appearances in 34 cases of autopsy-confirmed metastatic tumors of the pancreas including secondary malignant lymphoma are discussed. In 18 (53.8%) the pancreas appeared abnormal on computed tomography, the lesions being classified into three types: In 8 cases there was diffuse enlargement of the pancreas; in 9 cases a localized mass; and one patient had multiple low attenuated nodules within the organ. Histologic investigation revealed that metastatic carcinoma involved the pancreatic lobules. The degree of infiltration in the interlobular connective tissue was related to the invasiveness of the tumors. In the majority of cases with diffuse infiltration the pancreatic lobules were destroyed and varying degrees of proliferation of malignant cells into the interlobular septa were documented. In patients with localized infiltration there was extensive invasion of the carcinoma within the pancreatic lobule. Dilatation of the pancreatic duct and/or organ-related symptoms were occasionally seen in these cases.

Adult↗
PubMedDate not supplied

Oncocytic carcinoid of the lung.

The case of a 47-year-old man with an oncocytic variant of carcinoid of the lung is reported. Chest radiography disclosed a well-defined round mass in the left upper lobe of the lung. Contrast-enhanced CT demonstrated a homogeneously well-enhanced mass. The oncocytic variant of a typical carcinoid is a rare histological entity, which can be established only by the ultrastructural features of mitochondrial hyperplasia and membrane-bound electron dense granules. Therefore, the definite diagnosis of oncocytic carcinoid tumor necessitates ultrastructural observation.

Carcinoma, Adenoid Cystic↗