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Biomedical subjects

K Yokoo

Publications and source records attributed to K Yokoo.

At least 19 recordsLinked to original sources
PubMed2004

Cell proliferation and tumour suppressor gene expression in iodine unstained area surrounding oral squamous cell carcinoma.

The purpose of this study was to investigate the relationship between epithelial dysplasia unstained with iodine and the expression of proliferating cell nuclear antigen (PCNA) and/or tumour suppressor gene (p53) and the existence of glycogen. Thirty cases of squamous cell carcinomas arising from the buccal mucosa and floor of the mouth were examined. Iodine unstained areas were diagnosed histopathologically as mild, moderate or severe epithelial dysplasia. Normal oral mucosa stained with iodine was used as a control group. There was no histochemical difference in the distribution or ratio of PAS-positive cells between the control and the mild epithelial dysplasia groups, however PAS stained areas of the moderate and the severe dysplasia groups were significantly decreased. Ultrastructurally, glycogen granules were not recognized in the moderate or severe dysplastic epithelia. Immunoreactive ratios of PCNA and p53 in the moderate and severe dysplastic groups were significantly higher than those of the control and the mild dysplasia groups. The positive ratio of PCNA was higher than that of p53, although the immunostaining patterns of PCNA- and p53-positive cells were quite similar. These results suggest that mild dysplastic epithelia that are stained with iodine may be in the category of normal epithelia, whereas both moderate and severe dysplasia that are un-stained with iodine may be suspected of malignant lesions.

Carcinoma, Squamous Cell↗
PubMed2001

Possibility of venous return through bone marrow in the free fibular osteocutaneous flap.

The authors report a case of a free fibular graft that was successful as a result of venous return delivered through the bone marrow. A 26-year-old man underwent reconstruction of the left tibia and a soft-tissue defect of the lower leg. A free vascularized fibular bone and skin flap was elevated. The fibular vessels were anastomosed to the dorsalis pedis vessels. The elevated fibular bone was fixed to the tibia. The next day, reanastomosis was necessary because of venous thrombosis. However, the fibular vein rethrombosed, but blood flow was ascertained by Doppler flowmetry, with darker blood flow being recognized from the edge of the flap. Four days after surgery, the skin color gradually improved, and the flap had almost completely taken. On retrospective evaluation, the authors concluded that this flap succeeded because venous return was routed through the bone marrow in the free fibular graft.

Adult↗
PubMed2001

Endoscopic correction of pectus excavatum.

Endoscopic surgery is minimally invasive and can be used to achieve superior cosmetic results. Conventional correction of pectus excavatum results in a long scar. Correction by use of endoscopic surgery involves a smaller skin incision. In this study, endoscopic correction of pectus excavatum was performed in 20 cases. A small transverse skin incision was made above the xyphoid process. A wide area beneath the pectoralis major muscle was dissected under endoscopic visualization. Subperichondrial resection was performed under direct visualization when possible. Subperichondrial resection of the third or fourth rib was performed under endoscopic visualization. Ravitch's chondrotomy of the second or third rib was performed under endoscopic visualization. Endoscopy was also useful for sternal elevation, with minimal risk of pleural perforation. Kirschner wire was inserted percutaneously under the sternum to prevent postoperative paradoxical respiration. In all cases, the postoperative course was uneventful. The advantages of endoscopic pectus excavatum correction are a short scar, control of bleeding, safe dissection of the pleura from the sternum without the risk of pleural perforation, and ease of sternal elevation without injury to the intramammary vessels. However, the endoscopic operation is long and is not useful in adults because subperichondrial resection in adults is difficult to perform.

Child↗
PubMed2000

Detection of serum antibodies to Bartonella henselae and Coxiella burnetii from Japanese children and pregnant women.

The participation of Bartonella henselae and Coxiella burnetii in the pathogenesis of fever of unknown origin (FUO) and lymphadenopathy has not been completely clarified. Prevalence of these two agents in Japanese children is also unknown. Serum IgG and IgM antibodies to B. henselae and to C. burnetii were examined by the indirect fluorescence antibody assay. Enzyme immunoassay kits were used to detect serum IgG and IgA antibodies against Chlamydia trachomatis. Out of 200 healthy normal pregnant women, two (1.0%) had serum IgG antibodies to B. henselae, four (2.0%) to C. burnetii and 49 (24.5%) to C. trachomatis. Out of 29 patients with FUO, one (3.4%) had serum IgG antibodies to B. henselae, four (13.8%) to C. burnetii and none to C. trachomatis. Out of 31 patients with cervical lymphadenopathy, three (9.6%) had serum IgG antibodies to B. henselae, two (6.5%) to C. burnetii and none to C. trachomatis. Out of 22 patients with generalized lymphadenopathy, one (4.5%) had serum IgG antibodies to B. henselae, three (13.6%) to C. burnetii and none to C. trachomatis. Prevalences of serum antibodies to C. burnetii in the patients with FUO and generalized lymphadenopathy and to B. henselae in the patients with cervical lymphadenopathy were significantly higher than those of normal pregnant women (Welch's t-test; P<0.01). These two agents may have some roles in the pathogenesis of FUO and lymphadenopathy in Japanese children.

Adolescent↗
PubMed1997

Testicular efferent ductule cyst of a dog.

A 9-year-old male Shetland Sheepdog had a small mass in the left testis. Grossly, the round to oval cyst was present at the upper pole of the testicular parenchyma near the head of the epididymis. Histologically, the cyst was lined by a single layer of nonciliated and ciliated epithelial cells. Immunohistochemically, the epithelial cells of the cyst showed expression of the low- and high-molecular-weight cytokeratins, vimentin, and desmin similar to that of normal efferent ductules in the dog. The testicular cystic dysplasia was thought to originate from the efferent ductules.

Animals↗
PubMed1995

Nuclear bodies appearance rate in canine testicular Sertoli cell tumor.

A number of nuclear bodies (NB) were observed in the canine testicular Sertoli cell tumors (SCT). We statistically examined nineteen cases of canine SCT concerning the NB appearance rate (NBAR), and also examined the NBAR in four cases of the normal testicular Sertoli cells. The mean value of the total number of the NBAR of SCT was significantly higher than that of normal Sertoli cells. The SCT were classified into three groups according to the Nielsen and Lein's histological classification (1974): intratubular SCT without invasion, intratubular SCT with invasion, and diffuse type SCT. The mean value of NBAR of the diffuse type SCT was significantly higher than that of the intratubular SCT with and without invasion, and there was no significant difference between the mean values of NBAR of the latter two groups. The distribution of NBAR of the diffuse type SCT was significantly different from that of the intratubular SCT with and without invasion. On the other hand, the individual differences of NBAR of the diffuse type SCT and the intratubular SCT with invasion was significantly higher than that of the intratubular SCT without invasion. The present study suggests that the increase of NBAR in canine SCT might be correlated with the tumor invasive progression.

Animals↗
PubMed1994

Composite gastric seromuscular and omental pedicle flap for urethral and scrotal reconstruction after Fournier's gangrene.

A new composite gastric seromuscular and omental pedicle flap is described that can provide immediate airtight or watertight closure in the repair of complex defects involving the urethra. This flap was used to repair defects of the urethra, scrotum, and abdominal wall in a patient with Fournier's gangrene. The seromuscular patch was sutured to the urethral defect, and the omentum was applied over the defects of the scrotum and abdominal wall. This new procedure made it possible to close the skin primarily without leakage or infection. The patient had an uncomplicated recovery. Postoperative urethrography demonstrated no leakage or stenosis.

Abdominal Muscles↗
PubMed1994

Confronting cisternae in canine testicular seminoma: special reference to appearance rate.

A number of confronting cisternae (CC) were found in canine testicular seminomas (SEM). The CC consisted of two or three closely attached cisternae separated by an electron-dense layer, but occasionally four or more cisternae were stacked in a similar fashion. They showed a short, straight, and direct continuity with the rER or the nuclear envelope. They were found in SEM cells of both interphase and mitotic stages. We statistically examined 18 cases of canine SEM concerning the CC appearance rate in interphase cells (CCARI) and in mitotic cells (CCARM), and the tumor mitotic index (TMI). The SEM were classified into three groups (intratubular SEM without invasion, intratubular SEM with invasion, and diffuse type SEM) using Nielsen and Lein's classification (1974). The CCARI and TMI of the diffuse type SEM were significantly higher than those of the intratubular SEM with invasion, and those of the latter group were significantly higher than those of the intratubular SEM without invasion. On the other hand, the CCARM were similar between these three groups, and this parameter showed a non-significant correlation with the TMI. The present study suggests that the increase in the number of CC in interphase canine SEM cells might be correlated with the tumor progression.

Animals↗
PubMed1990

Systemic absorption of sulphadiazine, silver sulphadiazine and sodium sulphadiazine through human burn wounds.

Systemic absorption of water-soluble and water-insoluble drugs through human burn wounds was compared. Serum levels of sulphadiazine were estimated after application of silver sulphadiazine (water-insoluble) cream, sulphadiazine (water-insoluble) cream and sodium sulphadiazine (water-soluble) cream. It was found that the absorption of sodium sulphadiazine was greater than that of sulphadiazine or silver sulphadiazine.

Absorption↗
PubMed1990

Proposal of leukotoxin, 9,10-epoxy-12-octadecenoate, as a burn toxin.

It is postulated that toxic substances (burn toxin) synthesized in burned skin are transferred into general circulation and cause multiple organ failure. We found a highly cytotoxic substance, leukotoxin, a linoleate epoxide, exists in burned skin. Leukotoxin, as the name indicates, was synthesized by leukocytes from linoleate as a substrate. The aim of this study is to evaluate the possibility of leukotoxin as a burn toxin. We studied plasma leukotoxin level of four patients with extensive burns (over 50% of body surface area) and examined coagulation studies in these patients. We detected considerable amounts of leukotoxin (11.4 nmol/ml-37.0 nmol/ml) in all patients. Leukotoxin was not detected in the control subjects. Pulmonary edema, cardiac failure, and coagulation abnormalities were found in these patients. Exogeneously administered leukotoxin induced similar pathological conditions in experimental animals to those observed in patients with extensive burns. Hence, it is concluded that leukotoxin is a responsible substance as a burn toxin.

Adult↗
PubMed1989

[Acute myelogenous leukemia with recurrence of the meningeal, spinal cord and the optic nerve infiltration with remission induction by Co therapy and maintained by intrathecal chemotherapy with Ommaya reservoir].

A 42-year-old woman was diagnosed as having acute myelogenous leukemia (M 2 of FAB classification) in May, 1985. Complete remission was achieved with the BHAC-DP therapy (BHAC, daunomycin and prednisolone). Whole skull irradiation and intra thecal chemotherapy were performed by way of prevention. In 1986, she developed her visual disturbance and paraplegia. Myelography and metrizamide CT indicate intraspinal and meningeal infiltration of leukemic cells in the upper thoracic spine. Leukemic cells were found in the cerebrospinal fluid but not in the bone marrow. Complete remission was obtained by irradiation and intrathecal chemotherapy. In Dec. 1986, Ommaya tubing was repeated. Hematological and neurological examinations showed no evidence of malignancy for 3 years. In Oct. 1988, she admitted to our hospital for the maintenance of the remission state, and died of sepsis. The result of autopsy revealed no leukemic cells in her CNS. It is said the intraspinal infiltration of leukemic cells is rather rare. As it is said the intrathecal injection of anti-leukemic agents is not effective for the intraspinal infiltration, irradiation should be needed. Therefore it is very important to critically differentiated intraspinal from meningeal infiltration. Furthermore, Ommaya tubing is effective in order to maintain remission in a patient with CNS leukemia.

Adult↗
PubMed1989

[The trial use of alpha-IFN in treating a case of chronic myelomonocytic leukemia with splenic infarction].

A 75-year-old man, previously diagnosed as having chronic myelomonocytic leukemia, suffered an attack of severe left hypochondralgia in July 1986. A splenic infarction was diagnosed by both ultrasound tomography and computerized tomography. The patient was treated with alpha-Interferon (600 M.U./day i.m.) for cytoreduction in order to prevent a recurrence of the splenic infarction. Twenty-one days later, the peripheral white blood cell count decreased from 44,110 microliters to 9800/microliters and the monocytoid immature cells disappeared. However, severe dementia appeared and so alpha-Interferon therapy was abandoned. In this report the beneficial effects and side effects of alpha-interferon in the treatment of chronic myelomonocytic leukemia are discussed.

Aged↗
PubMed1986

A quantitative assay for the detection of hepatitis B virus DNA employing a biotin-labeled DNA probe and the avidin-beta-galactosidase complex.

We have developed a procedure for the quantitation of specific DNA which employs nonradioisotopic probes and beta-galactosidase as a detector. The sample DNA was immobilized on a nitrocellulose filter paper. After the filter paper had been processed to hybridization with a biotinylated probe DNA, the paper was incubated with avidin-beta-galactosidase complex. The optimum ratio of avidin to biotinylated beta-galactosidase for preparation of a complex between the two was determined. The filter paper was punched. Each punched piece was put into a microtiter well and beta-galactosidase activity was measured using 4-methylumbelliferyl beta-D-galactosidase as a substrate. By this method, we were able to quantify as little as a few picograms of specific DNA. The application of this method for the quantitative assay of hepatitis B virus DNA in serum sample is also described. The sensitivity for the detection of the DNA by our method was practically comparable to that of the conventional radioisotopic method. The validity of our method for detection of the virus DNA was further supported by comparison with the serological data.

Avidin↗
PubMed1986

Neutrophils biosynthesize leukotoxin, 9, 10-epoxy-12-octadecenoate.

An epoxy derivative of linoleate, 9,10-epoxy-12-octadecenoate, was demonstrated to be biosynthesized by neutrophils from various sources such as canine and human blood, and guinea-pig peritonea. It was nominated as leukotoxin from its 'toxic' activity onto mitochondrial respiration. From the reaction mixture of leukocytes with linoleate, an isomer of leukotoxin, 12,13-epoxy-9-octadecenoate, and a 'non-toxic' hydroxy derivative of linoleate, 9-hydroxy-12-octadecenoate, were detected. Such a cascade reaction of linoleate by leukocytes was discussed. Biosynthesis of leukotoxin by neutrophils was substantially enhanced by the presence of calcium ion and calcium-ionophore, A23187. Neutrophils contained leukotoxin, ca. 7 f moles/cell, which was extractable by 60% ethanol, but little of the isomer.

Animals↗