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Biomedical subjects

K Yokoi

Publications and source records attributed to K Yokoi.

At least 37 records · Page 2Linked to original sources

Reconstruction of large nasal defects with a combination of local flaps based on the aesthetic subunit principle.

Herein is described a technique that uses a combination of local flaps to reconstruct large defects involving the nasal dorsum and cheek. The flaps used are a transposition flap elevated from the area adjoining the defect and bilateral cheek advancement flaps. This technique leaves all suture wounds at borders of the aesthetic subunits that have been described previously. Color and texture matches were good and symmetrical. The transposition flap can be modified according to whether the defect includes the nasal tip. After raising the cheek advancement flap, it is also possible to use a dog-ear on the nasolabial region for any alar defects. Nine patients were treated using this procedure. The technique is very reliable (no complications such as congestion and skin necrosis in our series) and is easy to perform. One patient had palpebral ectropion after the operation and underwent secondary repair. In this series, defects measuring 45 x 30 mm in maximum diameter and including the nasal dorsum, nasal tip, ala, and cheek were treated.

Adult↗

Seaweed prevents breast cancer?

To investigate the chemopreventive effects of seaweed on breast cancer, we have been studying the relationship between iodine and breast cancer. We found earlier that the seaweed, wakame, showed a suppressive effect on the proliferation of DMBA (dimethylbenz(a)anthracene)-induced rat mammary tumors, possibly via apoptosis induction. In the present study, powdered mekabu was placed in distilled water, and left to stand for 24 h at 4 degrees C. The filtered supernatant was used as mekabu solution. It showed an extremely strong suppressive effect on rat mammary carcinogenesis when used in daily drinking water, without toxicity. In vitro, mekabu solution strongly induced apoptosis in 3 kinds of human breast cancer cells. These effects were stronger than those of a chemotherapeutic agent widely used to treat human breast cancer. Furthermore, no apoptosis induction was observed in normal human mammary cells. In Japan, mekabu is widely consumed as a safe, inexpensive food. Our results suggest that mekabu has potential for chemoprevention of human breast cancer.

9,10-Dimethyl-1,2-benzanthracene↗

Gastrointestinal stromal tumor of the stomach diagnosed preoperatively.

A case of gastrointestinal stromal tumor (GIST) of the stomach is reported. GIST has been applied to gastrointestinal submucosal tumors mainly composed of spindle shaped cells that represent neither typical features of myogenic nor neurogenic tumors, and immunohistochemical studies are necessary for the diagnosis of GIST. The patient was a 39-year-old man and was successfully diagnosed to be GIST (uncommitted type) preoperatively by immunohistochemical studies of biopsy specimens from an ulcerative submucosal tumor with bridging folds in the fundus, approximately 3.0 cm in size. Local excision of the stomach was performed. This is the 3rd case of GIST with a preoperative diagnosis to appear in the literature in Japan. For gastroenterological surgeons, it is critical to select the most suitable surgical procedure. In the present, because the number of papers reporting GIST of the stomach is small, it is impossible to review GIST clinicopathologically. We reviewed the surgical procedure for gastric leiomyosarcomas, because of including many cases with GIST in them. Therefore, we performed 54 cases of gastric GIST in the literature, compared with 92 cases of gastric leiomyosarcoma. As a result, it was thought that local excision for gastric GIST should be preferred.

Humans↗

X-ray crystallographic approach to the design of phenolic schiff base reagents for the mutual separation of lanthanoids.

A novel mutual selectivity of lanthanoids in the N,N'-bis(5-nitrosalicylidene)ethylenediamine (H2Nsalen)-KCl and N,N'-bis(5-nitrosalicylidene)-o-phenylenediamine (H2Nsaloph)-KCl extraction systems was evaluated by the X-ray analysis of similar model complexes for extracted species. Cerium(IV) complexes with N,N'-bis(5-chlorosalicylidene)ethylenediamine (H2Clsalen), N,N'-bis(salicylidene)-o-phenylenediamine (H2saloph) and N,N'-bis(3,5-dibromosalicylidene)-o-phenylenediamine (H2Br2saloph) were selected as the models. The result of the X-ray analysis suggested that [Ln(III)(Nsalen)2]- and [Ln(III)(Nsaloph)2]- are meridional type (two ligands are oriented perpendicular to each other) and sandwich type (two ligands are oriented parallel to each other), respectively. It was suggested that the selectivity of the meridional structure is superior to that of the sandwich structure in these extraction systems.

Journal Article↗

[A case of postoperative gastric cancer responding to adjuvant chemotherapy with TS-1--a novel oral formation of 5-fluorouracil].

TS-1 is a novel oral formation of 5-fluorouracil, developed using tegafur and two biochemical modulations. We report the case of a patient with multiple lymph node metastases from gastric cancer that markedly responded to TS-1. A 70-year-old man suffering from hematemesis was admitted to our hospital. Computed tomography showed advanced gastric cancer with huge lymph node metastases. After non-curative operation, he received adjuvant chemotherapy with TS-1 for 12 weeks. CT revealed that almost complete reduction of the metastatic nodes was obtained. No serious adverse reactions were observed.

Aged↗

The prognosis of patients with non-small cell lung cancer found to have carcinomatous pleuritis at thoracotomy.

Non-small cell lung cancer with carcinomatous pleuritis is considered to be a contraindication of surgical resection. The objective of this study was to clarify the prognosis of patients with non-small cell lung cancer in whom carcinomatous pleuritis was found at thoracotomy. A questionnaire survey on the survival of patients with carcinomatous pleuritis found at thoracotomy between January 1985 and December 1994 was conducted by the Japan Clinical Oncology Group. According to the data collected from 21 hospitals, 8813 patients with non-small cell lung cancer underwent thoracotomy, 284 (3.2%) of whom were found to have carcinomatous pleuritis. Information on survival was available for 227 of these patients, 34 (15%) of whom underwent thoracotomy alone without resection, whereas 193 (85%) underwent surgical resection. Of the 193 resected patients, 155 had no macroscopical residual tumor apart from the carcinomatous pleuritis. The 5-year survival rate was 14%. According to a univariate analysis, female sex, the presence of adenocarcinoma, a tumor size of less than 3.0 cm, no clinical lymph node metastasis, and no macroscopical residual tumor had a significantly favorable impact on survival. A multivariate analysis revealed that the extent of clinical lymph node metastasis (P = 0.006), histology (P = 0.028), and the absence or presence of a macroscopic residual tumor after the operation (P = 0.045) were predominant prognostic factors. The 5-year survival rate of 83 patients with three positive variables was 24%. The prognosis of patients with adenocarcinoma found to have carcinomatous pleuritis at thoracotomy was not necessarily unfavorable if there was no clinically detected lymph node metastasis and no residual tumor apart from the carcinomatous pleuritis.

Adenocarcinoma↗

Results of surgical treatment of lung cancer involving the diaphragm.

OBJECTIVES: Lung cancers with diaphragmatic invasion are categorized as T3 lesions, but the surgical results have not been well known. We retrospectively surveyed patients with resected primary lung cancers involving the diaphragm. METHODS: A total of 16,771 patients underwent surgical resection for lung carcinoma between 1986 and 1995 at 31 institutions of the Lung Cancer Surgical Study Group in Japan. By investigating the database, we identified 63 patients (0. 38%) who underwent resection of T3 lung cancer invading the diaphragm. These patients constituted the study population, and their clinical and pathologic records were retrospectively analyzed. RESULTS: Tumor invasion to the diaphragm was diagnosed before operation only in 17 patients (27.0%). Complete resections of the primary lung tumors with the invaded diaphragm were performed in 55 patients (87.3%), of whom 26 had T3 N0 M0 diseases and 29 had T3 Nl-2 M0 diseases. The operative mortality was 1.6% in all patients. The 5-year survival of patients with complete resection was 22.6%, but there was no 4-year survivor in patients with incomplete resection (P =.024). The survivals of patients with completely resected T3 N0 M0 and T3 N1-2 M0 tumors were 28.3% and 18.1%, respectively (P =.013). In those patients, the depth of diaphragmatic involvement significantly affected the prognosis. The 5-year survival of the patients with shallow invasion (parietal pleura or subpleural tissue involvement) was 33.0%, whereas that of the patients with deep invasion (muscle or peritoneal infiltration) was 14.3% (P =.036). CONCLUSIONS: In selected patients with lung carcinoma and diaphragmatic invasion, combined resection of the lung and diaphragm offers the prospect of cure with acceptable mortality. However, primary lung tumors with diaphragmatic invasion, especially invasion of the muscle layer or deeper tissue, are not considered to be T3 lesions, because these cancers are generally technically resectable but oncologically almost incurable.

Aged↗

Computed tomographic fluoroscopy-guided transthoracic needle biopsy for diagnosis of pulmonary nodules.

BACKGROUND: The purpose of this study was to evaluate the usefulness of computed tomographic (CT) fluoroscopy-guided transthoracic needle biopsy (TTNB) with an 18-gauge automatic biopsy gun for the diagnosis of pulmonary nodules. METHODS: Between March 1996 and January 1998, 50 patients in whom pulmonary lesions could not be diagnosed cytopathologically with fiberoptic bronchoscopy or were not clearly visualized with fluoroscopy underwent CT fluoroscopy-guided TTNB. RESULTS: Final pathological diagnoses were 23 lung carcinomas, five pulmonary metastases and 22 benign lesions. Sufficient tissue for analysis was obtained from 48 of the 50 lesions (96%). The overall diagnostic yield of CT fluoroscopy-guided TTNB was 90%. The sensitivity, specificity and accuracy for malignancy were 89%, 100% and 94%, respectively. In 20 of the 22 cases (91%) of benign lesions, histological analysis yielded correct and specific diagnoses. Complications occurred in 22 of the 50 cases (44%). The most common complication was pneumothorax, which occurred in 21 of the 50 cases (42%). Chest tube insertion was required in 6 (12%). CONCLUSIONS: Although CT fluoroscopy could not decrease the complication rate, CT fluoroscopy-guided TTNB with an automatic biopsy gun appears to be a promising technique for diagnosing pulmonary lesions, particularly benign lesions.

Adenocarcinoma↗

Nasal reconstruction based on aesthetic subunits in Orientals.

Reconstruction based on the aesthetic subunit principle has yielded good aesthetic outcomes in patients with moderate to severe nasal defects caused by trauma or tumor resection. However, the topographic subunits previously proposed are often unsuitable for Orientals. Compared with the nose in white patients, the nose in Orientals is low, lacks nasal muscle, and has a flat glabella; the structural features of the underlying cartilage and bone are not distinctly reflected in outward appearance. The authors devised aesthetic subunits suitable for Orientals, and they used these units to reconstruct various parts of the nose. The major difference between these units and those presented previously is the lack of soft triangles and the addition of the glabella as an independent unit. The authors divided the nose into the following five topographic units: the glabella, the nasal dorsum, the nasal tip, and the two alae. The border of the nasal dorsum unit was extended to above the maxillonasal suture. The basic reconstruction techniques use a V-Y advancement flap from the forehead to reconstruct the glabella, an island flap from the forehead to reconstruct the nasal dorsum and nasal tip, a nasolabial flap to reconstruct an ala, and a malar flap to reconstruct the cheek. A combination of flaps was used when the defect involved more than one unit. This concept was used for nasal reconstruction in 24 patients. In one patient undergoing reconstruction of the nasal dorsum and in one undergoing reconstruction of the nasal tip, the texture of the forearm flap did not match well, which resulted in a slightly unsatisfactory aesthetic outcome. In one patient in whom the glabella, nasal dorsum, and part of the cheek were reconstructed simultaneously, a web was formed at the medial ocular angle, and a secondary operation was subsequently performed using Z-plasty. In one patient undergoing reconstruction with a forehead flap, defatting was required to reduce the bulk of the subcutaneous flap pedicle at the glabella. However, suture lines were placed in the most inconspicuous sites in all patients, and the use of a trapdoor contraction emphasized the three-dimensional appearance of the nose. The use of these aesthetic subunits for reconstruction offers several advantages, particularly in Oriental patients. Because the nasal dorsum is reconstructed together with the side walls, tenting of the nasal dorsum is avoided, which prevents a flat appearance of the nose. A forehead flap is useful in the repair of complex defects. Defects of the alae should be separately reconstructed with a nasolabial flap to enhance the effect of the trapdoor contraction and to highlight the three-dimensional appearance of the nose. Candidates for reconstruction should be selected on the basis of nasal structure. The results suggest that these units can also be used in some white patients.

Adult↗

Relationships between a roller and a dynamic pressure distribution in circular hydraulic jumps

We investigated numerically the relation between a roller and the pressure distribution to clarify the dynamics of the roller in circular hydraulic jumps. We found that a roller which characterizes a type II jump is associated with two high pressure regions after the jump, while a type I jump (without the roller) is associated with only one high pressure region. Our numerical results show that building up an appropriate pressure field is essential for a roller.

Journal Article↗

Mean corpuscular volume may be a useful index of risk for colorectal adenoma in middle-aged Japanese men.

OBJECTIVE: It has been reported that alcohol intake and folate deficiency are associated with an increased risk of colorectal adenomas and carcinomas. Mean corpuscular volume (MCV) of red blood cells has been reported to be increased in these conditions. The purpose of this study was to assess the association between MCV and risk of colorectal adenoma. METHODS: The subjects were 497 middle-aged (45-65 yr old) men who underwent both barium enema examination and total colonoscopy. The subjects answered a questionnaire regarding their alcohol consumption history, and their blood samples were analyzed. The subjects were divided into four groups three times: with or without alcoholism, and with or without adenoma according to alcohol intake, and according to the MCV value. Various variables were compared among the groups, and the odds ratios of adenoma were calculated. RESULTS: The MCV was higher in the alcoholic group than in the nonalcoholic group (p < 0.01) and in patients with adenoma than in those without adenoma (p < 0.0001). When the subjects were stratified by alcohol intake, the MCV value had a higher significant difference than alcohol intake, between patients with adenoma and those without adenoma. As for the MCV value, the odds ratio (95% confidence interval) of adenoma was 1.00 (referent); (<92), 1.20 (0.71-1.69); (> or =92 but <95), 2.61 (2.07-3.15); (> or =95 but <98); and 3.62 (2.99-4.25); (> or =98). CONCLUSION: A high MCV value may be used as a simple index of the risk of colorectal adenomas, regardless of alcohol consumption.

Adenoma↗

A successful surgical repair of the hepatic hydrothorax using pneumoperitoneum: report of a case.

A successful surgical repair of a right hepatic hydrothorax in the absence of ascites is reported. A technetium-99m scintigram that was injected intraperitoneally provided evidence of a one-way flow of fluid from the peritoneal to pleural cavity. To identify any possible minute defects in the diaphragm, carbon dioxide was insufflated into the peritoneal cavity during the operation. We performed a direct suture of the defect observed on the diaphragm. The pleural effusion subsequently vanished after the operation.

Humans↗

Polyatomics in zinc isotope ratio analysis of plasma samples by inductively coupled plasma-mass spectrometry and applicability of nonextracted samples for zinc kinetics.

Inductively coupled plasma-mass spectrometry (ICP-MS) is a powerful tool for both quantitative multielement analyses of inorganic elements and measurement of isotope ratios (IRs). The main disadvantage of this technique is the existence of polyatomic isobaric interferences at some key masses. Zinc has been investigated for such potential interferences in serum or plasma. The Zn isotopes, 66Zn and 68Zn, have no apparent interferences, but 32S1602 and 32S2 are isobaric with 64Zn. The possible effects of S and other major components of blood plasma-Na, K, Cl, P, Ca-on Zn IRs were investigated using a series of mineral solutions which simulated human plasma with respect to these elements. The mixture of all mineral elements interfered only with 64Zn (6.66 ng/mL) and 70Zn (8.51 ng/mL). Interferences to 66Zn, 67Zn, and 68Zn were minimal containing 0.90, 0.94, and 0.39 ng/mL, respectively. The copresence of Na or S shifted 35Cl16O2 (atomic mass 67 coming from Cl solution) to 35Cl2 which reduced the contribution to 67Zn. The hypothesis that Zn IRs obtained from plasma at various intervals after the intravenous administration of enriched 67Zn to humans would reflect those obtained after extraction of Zn was therefore tested. To compare the two pretreatment methods, "extraction" versus "nonextraction," specimens were collected from 10 human subjects at intervals of 5 min to 24 h postinjection, and in 4 subjects from 5 min to 9 d postinjection. Two separate aliquots of plasma from each time-point were dried and digested with hydrogen peroxide, and the residue dissolved in nitric acid. One specimen was subjected to zinc extraction using ammonium diethyldithiocarbamate chelate followed by back extraction into nitric acid. The matching aliquot received no further pretreatment. The normalized IRs obtained from 67Zn/66Zn and 67Zn/68Zn in both the "extracted" and "nonextracted" samples agreed well (r2 = 0.976 and r2 = 0.985, respectively) compared to those from other ratios (r2 = 0.838 for 67Zn/64Zn and r2 = 0.747 for 67Zn/70Zn). Considering the minimum possibility of isobaric interferences in plasma samples, 67Zn/68Zn obtained from "nonextracted" samples is sufficient for routine Zn kinetic analysis by ICP-MS.

Argon↗

Radiation therapy for roentogenographically occult lung cancer by external beam irradiation and endobronchial high dose rate brachytherapy.

PURPOSE: We investigated the clinical usefulness of radiation therapy by external beam irradiation and endobronchial brachytherapy for the treatment of roentogenographically occult lung cancer. PATIENTS AND METHODS: From 1995 to 1996, five patients were treated with radiation therapy. We analyzed their treatment outcomes. The follow-up period varied from 3.0 to 3.8 years or until death. External beam radiation (40 Gy/20 fractions/4 weeks) was delivered to the tumor site alone, and not prophylactically given to the mediastinum. Endobronchial brachytherapy using high dose rate iridium (Ir)-192 was concurrently administered principally to a total dose of 18 Gy on the bronchial mucosa in three weekly fractions of 6 Gy each. RESULTS: Complete remission was obtained in all patients. Two patients died of intercurrent diseases at 12 and 21 months without any evidence of recurrence. The disease has been also controlled in the other three cases. With the above doses, three small tumors < 1 cm were controlled without adverse effect. In two tumors, the dose reference points were set 2-7 mm beneath the mucosa, and larger doses were administered by brachytherapy. An applicator acting as a spacer was not used in these cases. The tumors were controlled, although the irradiated bronchi showed severe stenosis in 6 months following the treatment. However, the patients were asymptomatic and did not need further intervention. CONCLUSION: External beam irradiation combined with endobronchial brachytherapy was useful for the treatment of roentogenographically occult lung cancer as an alternative to surgery. Further investigation is needed to determine the optimal doses of radiation therapy.

Aged↗

A case report of gastric carcinosarcoma with rhabdomyosarcomatous and neuroendocrinal differentiation.

We report herein an unusual gastric carcinosarcoma with rhabdomyosarcomatous and neuroendocrinal differentiation in a 63-year-old Japanese male. The tumor was a pedunculated large polypoid tumor (7 x 6.5 x 3.5 cm) located in the pylorus. Histologically, it invaded to the subserosa and was composed of both adenocarcinomatous and sarcomatous components. Adenocarcinomatous foci generally showed tubular to solid patterns and occupied the parts facing the gastric lumen, while the sarcomatous components showed a generally irregular and solid arrangement. There were transitions between the sarcomatous and carcinoma elements. In addition, carcinoma cells with a cord-like or trabecular arrangement similar to that seen in endocrine carcinoma expressed chromogranin A, and were mainly observed in an intermediate area between the adenocarcinomatous and sarcomatous foci. The sarcomatous areas were mainly composed of spindle cells and occasionally contained a sarcomatous component showing rhabdomyosarcomatous differentiation. This is an interesting case to consider how the variety of cell type appeared in such a type of tumor in the stomach.

Biomarkers, Tumor↗

Endobronchial brachytherapy for recurrent thymoma showing endobronchial polypoid growth.

The authors report a case of recurrent thymoma displaying endobronchial polypoid growth. Initially, the patient had invasive thymoma with intracaval growth into the right atrium. He was treated with multimodality therapy consisting of chemotherapy, surgical resection, and radiotherapy (50.4 Gy). Both 3 years and 6 years after the initial treatment, the tumor recurred outside the reconstructed superior vena cava. The patient was treated with repeated radiotherapy (50.4 Gy and 40 Gy), and remission was achieved. Eight years after the first therapy, an endobronchial polypoid lesion was detected in the right upper lobe bronchus and was histologically found to be thymoma. Endobronchial high-dose rate brachytherapy (20 Gy at 3 mm/5 fractions) was carried out for palliation because the recurrent tumor occurred outside of the superior vena cava area, which had been reirradiated. After the treatment, the endobronchial tumor shrunk remarkably in size without adverse effects. No tumor regrowth has been noted after a follow-up of 10 months.

Aged↗