PubMed Health⌕ Search

Biomedical subjects

A Yanai

Publications and source records attributed to A Yanai.

At least 19 recordsLinked to original sources
PubMed1992

An analysis of proliferating cells in biopsy specimens from patients with small hepatocellular carcinoma.

The proliferation of neoplastic and nonneoplastic hepatocytes is caused by various humoral growth factors with autocrine and paracrine mechanisms, and the proliferative activity of both hepatocytes and nonhepatocytic cells contributes to neoplastic growth. The authors attempted to detect various kinds of proliferating cells immunohistochemically in small hepatocellular carcinoma (HCC) using a monoclonal antibody against DNA polymerase alpha. Most of the HCC cells that stained for this enzyme were small, had basophilic cytoplasm with poorly developed organelles, and aggregated to form clusters distributed randomly within cancer nests. Nonhepatocytic cells also were stained, including some endothelial cells, Kupffer's cells, macrophages, and lymphocytes. Fat-storing cells were not stained. The number of stained sinusoidal (capillary) cells decreased in this order: Kupffer's cells and macrophages, endothelial cells, and fat-storing cells. Nonhepatocytic cells, including lymphocytes, proliferated more actively in areas with actively growing HCC cells than in those with quiescent cancer cells. The relationship between stained HCC cells and stained sinusoidal cells was clearly defined; the correlation coefficient was 0.97. These findings suggest the possibility of a relationship between the proliferative activity of neoplastic hepatocytes and that of sinusoidal cells, including lymphocytes.

Aged↗
PubMed1992

Bury-and-knot suturing method.

An innovative bury-and-knot suturing method for firm fixation of a graft through a small skin incision is described and two clinical cases presented.

Dermatologic Surgical Procedures↗
PubMed1992

Skull base reconstruction in cases of intracranial teratoma extending into the extracranial structures.

Recently experienced were two cases of postnatally diagnosed intracranial teratoma, one a mature teratoma and the other an immature teratoma, both extending into the extracranial structures. In each case, tumor resection was performed in which a barrier was created between the intracranial and extracranial spaces with a temporalis muscle flap. The technical aspect of skull base reconstruction is described, and previously reported cases of intracranial teratoma involving the skull base are reviewed.

Brain Neoplasms↗
PubMed1992

Transinterosseous transfer of a peroneal island flap for reconstruction of prepatellar skin defect: report of two patients.

We describe the use of a peroneal vascular transinterosseous island flap for the resurfacing of a prepatellar skin defect in 2 patients. Being a fasciocutaneous flap, the peroneal flap is thin, and the location of perforators is easily and safely detected with a Doppler flowmeter. When used as a vascular island flap, either a distal pedicle or a proximal pedicle can be used. The peroneal flap can be used as either a free flap or a vascularized fibular and fasciocutaneous flap. It may, therefore, be applied to compound skin, subcutaneous tissue, and bone defects in the lower extremities. A peroneal vascular transinterosseous island flap can reach a prepatellar skin defect, whereas the peroneal island flap with conventional proximal pedicle cannot.

Adult↗
PubMed1992

Molecular cloning of feline interferon cDNA by direct expression.

A cDNA sequence coding for feline interferon has been cloned for the first time by screening a cDNA library constructed using Okayama-Berg vector and mRNA derived from the feline cells (LSA-I) induced by TPA (12-o-tetradecanoylphorbor 13-acetate) for the ability of transient expression to produce feline interferon in COS1 monkey cells. The amino acid sequence, deduced from the nucleotide sequence by comparing it with the sequences of other mammalian IFNs, consists of 171 amino acids with 6 cysteins and an N-glycosylation site at the amino acid position 79, and has about 60% homology to human IFN alpha 1. The interferon was partially purified through Blue Sepharose, and its molecular weight was estimated to be 2.4 x 10(4). The antiviral activity was acid stable, and glycosylation was suggested.

Amino Acid Sequence↗
PubMed1992

Analysis of proliferating hepatocytes using a monoclonal antibody against proliferating cell nuclear antigen/cyclin in embedded tissues from various liver diseases fixed in formaldehyde.

The authors studied histochemically the morphologic features of proliferating hepatocytes positive for proliferating cell nuclear antigen (PCNA/cyclin) to analyze the process of liver regeneration in embedded tissues fixed with formaldehyde using an anti-PCNA/cyclin monoclonal antibody. In liver specimens from patients with acute viral hepatitis (AVH) and confluent necrosis, many small basophilic hepatocytes surrounding large clear hepatocytes were positively stained in the areas next to the confluent necrosis. Therefore these small hepatocytes may be daughter cells derived from large clear hepatocytes that probably enter the mitotic cell cycle repeatedly to repair a large necrotic area. In the case of AVH with spotty necrosis, the positively stained hepatocytes were scattered around the necrotic foci. In the liver specimens from patients with chronic active hepatitis, most of the positively stained hepatocytes were located next to the necrotic area. As for cirrhosis of the liver, the number of hepatocytes positive for PCNA/cyclin varied greatly in different pseudolobules, and in the specimens of hepatocellular carcinoma (HCC), the HCC cells positive for PCNA/cyclin were detected throughout the cancer nests.

Antibodies, Monoclonal↗
PubMed1992

Immunocytochemical identification of proliferative hepatocytes using monoclonal antibody to proliferating cell nuclear antigen (PCNA/cyclin). Comparison with immunocytochemical staining for DNA polymerase-alpha.

The authors investigated whether immunocytochemical staining with a monoclonal antibody to proliferating cell nuclear antigen (PCNA/cyclin) could be used to identify proliferative hepatocytes in frozen sections fixed in a mixture of periodate, lysine, and 2% paraformaldehyde. Paraffin sections also were used, which were fixed in 10% formaldehyde. Specimens of liver tissue were obtained from 27 patients with various hepatic diseases. Hepatocytes that were positive for PCNA/cyclin were observed in both types of substrate specimens. In acute hepatitis and chronic active hepatitis, most hepatocytes that were labeled for PCNA/cyclin were located near necrotic foci. However, in cirrhosis, they were detected most often near fibrotic septa; the number of immunoreactive cells varied greatly in different areas of tissue sections in such cases. In hepatocellular carcinoma, many PCNA/cyclin-positive tumor cells were seen throughout the neoplasms. Hepatocytes that were positive for DNA polymerase-alpha showed a similar distribution pattern in serial sections of study cases.

Adult↗
PubMed1991

Detection of proliferating liver cells in various diseases by a monoclonal antibody against DNA polymerase-alpha: with special reference to the relationship between hepatocytes and sinusoidal cells.

Proliferating cells in liver specimens from patients with various diseases were detected by use of a monoclonal antibody against human DNA polymerase-alpha, which is present in the nuclei of cells in the G1, S, M and G2 phases of the mitotic cell cycle and absent in the G0 phase, to clarify the kinetics and morphological characteristics of these cells. This monoclonal antibody was supernatant derived from clone CL22-2-42B, and the peroxidase antiperoxidase method was used. Not only epithelial cells (hepatocytes, biliary epithelial cells and hepatocellular carcinoma cells) but also nonepithelial cells (Kupffer cells and other macrophages, endothelial cells, fat-storing cells, lymphocytes and fibroblasts) were stained for DNA polymerase-alpha. In acute viral hepatitis with confluent necrosis, small hepatocytes with basophilic cytoplasm next to the necrosis accounted for most of the proliferating cells. In these areas, Kupffer cells and other macrophages and lymphocytes had often proliferated. Hepatocellular carcinoma cells were frequently stained for DNA polymerase-alpha, in addition to endothelial cells, macrophages and lymphocytes. These nonepithelial cells were stained more frequently in specimens with many stained carcinoma cells than in those with only a few cells stained. In fibrotic areas, fibroblasts were often stained for this enzyme. In proliferating bile ducts, both small epithelial cells and large mature cells were stained. The differences between stained and nonstained cells that were not hepatocytes could not be defined by their ultrastructural characteristics. From these findings, it seemed possible that sinusoidal cells, especially Kupffer cells and other macrophages, might be much involved in hepatocytic proliferation during regeneration of the liver and also in the occurrence of malignant tumors.

Adult↗
PubMed1991

Preventing denervation atrophy of a grafted muscle.

Electrodes were implanted in the grafted muscles of rabbits to generate continuous stimulation for the purpose of preventing denervation atrophy. Denervation atrophy could be prevented, to some extent, in dissected muscles with vascular pedicles not occluded during the experiment. Denervation atrophy was found to be promoted, rather than prevented, in grafted muscles with occluded vascular pedicles. The crucial conditions are varying stimulation and the long duration of occlusion (90 min). Overly strong stimulation of muscle contraction appears to result in "fatigue" of grafted muscles in which blood circulation has been blocked for more than the 90 min used in the reported experiment. Further investigations are necessary of the conditions of stimulation and the point in time at which stimulation should commence after grafting.

Animals↗
PubMed1991

Necrotizing sialometaplasia in the mouth floor secondary to reconstructive surgery for tongue carcinoma.

Necrotizing sialometaplasia is a benign inflammatory process, which histologically can mimic squamous cell carcinoma. A 63-year-old man underwent left hemiglossectomy involving transplantation of a myocutaneous flap for squamous cell carcinoma of the tongue. One month after the operation, necrotizing sialometaplasia occurred in the minor salivary gland tissue of the mouth floor, compressed by the necrotic flap. This case is very unusual because of the occurrence of necrotizing sialometaplasia in the floor of the mouth. The etiology of the lesion was considered to be ischemia secondary to compression by the necrotic myocutaneous flap.

Biopsy↗
PubMed1991

Detection of proliferating hepatocytes in patients with acute hepatic failure by mitotic figures and a monoclonal antibody against DNA polymerase alpha.

Information on the ultrastructure and phenotypes of proliferative hepatocytes is scarce, so we set out to detect proliferating hepatocytes immunohistochemically by use of a monoclonal antibody against DNA polymerase alpha (DNA-PA). The findings from this method were compared with conventional features, such as mitotic figures, and hepatic regeneration after injury was considered in the light of these findings. The subjects of the basic study were 23 patients with acute hepatic failure. There were 6.8 +/- 5.5 (mean +/- SD) mitotic hepatocytes per 1,000 hepatocytic nuclei, and 209 +/- 158 hepatocytes stained for DNA-PA per 1,000 hepatocytic nuclei. By light and electron microscopy (n = 4), hepatocytes stained for DNA-PA showed various morphological features, including development of organelles, but some resembled hepatocytes in mitosis. Accordingly, this histochemical method may be useful in studies of hepatic regeneration. In acute confluent necrosis, when hepatocytic proliferation is urgently needed for survival, small hepatocytes next to necrotic areas (probably immature cells, to judge from the development of their organelles) were predominant in hepatic regeneration. These findings suggest that hepatocytes in different stages of development can easily enter the mitotic cell cycle repeatedly when rapid regeneration is needed.

Antibodies, Monoclonal↗
PubMed1991

Resin sealant: a new method of methyl methacrylate cranioplasty. Technical note.

A new method of cranioplasty is described. The skull defect is exposed and multiple angled holes are drilled in the outer cortical bone around the defect. A resin plate is conventionally molded to fit the defect. After the resin plate is positioned in the skull defect, newly prepared viscous resin putty is injected into the holes around the defect. The viscous resin comes into contact with the margin of resin plate and, when it hardens, a monoblock casting of resin is formed. The resin plate is sealed to the bone. This technique has the main advantage of strength and good cosmetic appearance.

Bone Cements↗
PubMed1991

[Repair of widely infected scalp defect and osteomyelitis with free radial forearm flap: a case report].

A 60-year-old female was admitted with large frontal scalp defect associated with osteomyelitis due to chronic infection. Debridement of the infected scalp and frontal bone and the transplantation of the free radial forearm flap with vascular anastomosis was carried out. The wound cured uneventfully. Cranioplasty was performed ten months after the first operation. Transplantation of free radial forearm flap was first reported in 1982 by Song in China and has proved to be a very effective operative method, especially for the repair of large infected wounds. This is because good blood supply results from the anastomosis of larger vessels, and its cleansing effects can eradicate infections and prompt rapid wound healing.

Female↗
PubMed1990

Dye laser treatment of port-wine stains.

The author treated 456 cases of port-wine stains using a tunable dye laser (577-nm wavelength, 1-microsecond pulse, 2-3-mm diameter spot), and followed up 22 cases for a year or more after the initial treatment. The treatment was regarded as effective in 80.5% of the abnormal lesions. The results were influenced by location: good results were achieved in the neck region and face, but results in the extremities were poor. The dye laser can achieve selective injury to abnormal vessels of port-wine stains while inflicting less damage to the overlying dermis than the argon laser. Therefore, dye laser treatment for port-wine stains is more effective than argon laser treatment.

Adolescent↗