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Biomedical subjects

K Yokoi

Publications and source records attributed to K Yokoi.

At least 145 records · Page 8Linked to original sources
PubMed1993

[Multidisciplinary treatment of advanced invasive thymoma].

From February 1988 to September 1992, six patients with Stage III or IV invasive thymoma were enrolled onto our study of multidisciplinary treatment, which included chemotherapy, surgery, and radiotherapy. The chemotherapy consisted of cisplatin (20 mg/m2 continuous 24-hour infusion on days 1 through 4), doxorubicin (40 mg/m2 on day 1), and methylprednisolone (1,000 mg on days 1 through 4 and 500 mg days 5 and 6). Two patients received surgery (incomplete resection) and postoperative chemo/radiotherapy, and four patients received induction chemotherapy followed by surgery and chemo/radiotherapy. All patients with induction chemotherapy showed a partial response and underwent complete (n = 2) or partial (n = 2) resection. Four patients are alive with no evidence of disease for 31 to 55 months after the diagnoses. But two with partial resection after chemotherapy died of recurrent disease. Multidisciplinary treatment including chemotherapy may be a new therapeutic choice in management of advanced invasive thymoma.

Adult↗
PubMed1993

[Activation of coagulation and fibrinolysis in patients with abdominal true aortic aneurysm associated with disseminated intravascular coagulation].

Two cases of abdominal true aortic aneurysm (AAA) associated with disseminated intravascular coagulation (DIC) were reported. Case 1 was an 81-year-old male who was admitted because of hematoma on the left leg and in whom was found by MRI an aortic aneurysm of 14 cm in diameter. Coagulation studies indicated DIC by revealing thrombocytopenia, hypofibrinogenemia and increased level of FDP. DIC was well controlled by surgical repair of the aneurysm after the administration of a small dose of heparin. Case 2 was a 60-year-old male who was admitted because of lumbago and hematoemesis and in whom was found by CT and echography an aortic aneurysm of 5.5 cm in diameter. Coagulation studies indicated DIC by revealing thrombocytopenia and an increased level of FDP. On the 2nd hospital day, he suddenly died due to the rupture of the aortic aneurysm. In most of 9 cases with AAA without DIC, plasma levels of thrombin-antithrombin III complex, plasmin-alpha 2 plasmin inhibitor complex and FDP-D dimer were also elevated. These findings indicate that the coagulation and fibrinolysis systems were generally activated in patients with AAA, and that DIC tends to occur in patients with a giant aortic aneurysm or an impending ruptured aneurysm.

Aged↗
PubMed1992

Phase II study of cisplatin as a 5-day continuous infusion with vindesine plus recombinant human granulocyte-colony-stimulating factor in the treatment of advanced non-small-cell lung cancer.

A total of 36 patients with advanced non-small-cell lung cancer (NSCLC) were treated with a combination of 5-day continuous i.v. infusion of cisplatin (25 mg/m2 daily), bolus infusion of vindesine (3 mg/m2) on days 1 and 8, and s.c. injection of recombinant human granulocyte-colony-stimulating factor (2 micrograms/kg daily) on days 6-21. Treatment was repeated every 3-4 weeks. Responding patients with stage IIIA or IIIB disease received chest radiation therapy (50-60 Gy) after this treatment. One complete response and 23 partial responses were observed, for an overall response rate of 66.7% (24/36; 95% confidence limits, 51.3%-82.1%). The median duration of response was 5.7 months and the median overall survival was 10.1 months. WHO grade 3 or 4 leukopenia and neutropenia occurred in 22 (61%) and 27 (75%) patients, respectively, but the mean duration of leukopenia (< 2,000/mm3) and neutropenia (< 1,000/mm3) was 3.4 and 3.5 days, respectively, and there was no instance of life-threatening infection. Thrombocytopenia and anemia of grade 3 or 4 occurred in 28% and 36% of our subjects, respectively. Grade 2 nausea and vomiting occurred in 47% of the patients. Elevated serum creatinine levels (> 1.5 mg/dl) were observed in 3 (8%) of the 36 patients. One patient died of acute renal failure induced by hemorrhage of a gastric ulcer. This regimen is effective in the treatment of NSCLC and further studies of this combination are warranted.

Actuarial Analysis↗
PubMed1992

Invasive thymoma with intracaval growth into the right atrium.

We report an unusual case of invasive thymoma with intracaval growth into the right atrium. Computed tomography and venacavography demonstrated this manner of extension of thymoma. The tumor was completely removed by means of cardiopulmonary bypass after four courses of chemotherapy. Multidisciplinary treatment for invasive thymoma with this growth pattern is thought to be useful.

Aged↗
PubMed1992

Scar formation in the cardiac conduction system of a patient with Takayasu's arteritis.

An autopsied case of Takayasu's arteritis associated with complete atrioventricular (AV) block is described for the first time. The findings of scar formation and diffuse infiltration of lymphocytes into the cardiac conduction system, particularly the AV node, were similar to those in patients with connective tissue diseases or congenital complete heart block. The degree of AV block progressed with aggravation of the disease. These findings suggest that complete AV block may have been induced by acquired autoimmunity involving the cardiac conduction system.

Atrioventricular Node↗
PubMed1992

Effect of extracorporeal shockwave lithotripsy for urolithiasis on concentrations of creatine kinase isozymes in patient serum and urine.

To determine whether extracorporeal shockwave lithotripsy (ESWL) for urolithiasis causes renal injury, we immunoassayed creatine kinase isozymes (CK-B and CK-M) in serum and urine from patients with renal stone (n = 21) and ureteral stone (n = 18) before and after (0, 2, and 24 h) ESWL. CK-B is generally present in renal tissue at relatively high concentrations, whereas CK-M is found at low concentrations. CK-B and CK-M levels were enhanced both in the serum and urine samples after ESWL in both groups of patients but CK-B levels return to almost normal very rapidly. Because CK-M, which is mainly localized in muscle tissue, also increased in both groups, the increased CK-B in serum after ESWL might be derived not only from kidney but also from muscle tissues which also contain a significant level of CK-B. These results suggest that significant tissue injury, including kidney and muscles, might be caused by ESWL treatment for urolithiasis but there is no long-term renal adverse effect, and that creatine kinase isozymes in serum and urine might be useful markers of tissue injury by such treatment.

Adult↗
PubMed1992

A pituitary specific point mutation of codon 201 of the Gs alpha gene in a pituitary adenoma of a patient with multiple endocrine neoplasia (MEN) type 1.

The DNA from a pituitary adenoma of a patient with multiple endocrine neoplasia (MEN) type 1 was analyzed to detect a point mutation of the Gs alpha gene (gsp) by the PCR direct-sequencing method. The patient had galactorrhea, amenorrhea and acromegalic features. Hormonal examination revealed high serum levels of PRL and GH. The tumor was histologically diagnosed as a mixed GH cell-PRL cell adenoma in which GH and PRL were produced by different cells. Sequence analysis of the DNAs extracted from paraffin sections of pituitary, parathyroid, and pancreas tumors demonstrated the substitution of thymidine for cytidine in codon 201 of the Gs alpha gene that resulted in replacement of arginine (CGT) with cysteine (TGT) only in the pituitary adenoma, but not in the parathyroid and pancreas tumors. These results suggest that a pituitary specific point mutational activation of the Gs alpha gene may be involved in the development of the pituitary adenoma in this patient.

Adenoma↗
PubMed1992

[A case of pulmonary metastasis from carcinosarcoma of uterus with subcutaneous implantation of tumor cells along the needle tract after percutaneous needle biopsy of lung].

A 68-year-old female who had undergone total hysterectomy for carcinosarcoma five months previously was noted to have a solitary nodular shadow in the right lung on chest X-ray. Percutaneous needle biopsy of the lung was performed via the right anterior chest wall, and the histologic findings showed metastasis from carcinosarcoma of uterus. Two months after needle biopsy, a chest wall mass appeared of the site of puncture of the lung needle biopsy. The mass was resected to relieve the chest wall pain and the specimen showed carcinosarcoma of uterus histologically. We consider that tumor cells were implanted to the chest wall along the needle tract after percutaneous needle biopsy of the lung. The postoperative chest computed tomogram showed the route of tumor implantation from the metastasis of right lung into the right chest wall. Dissemination and chest wall implantation of malignant cells after percutaneous lung needle biopsy have been rarely reported. However there are no reports of tumor implantation of sarcoma. The possibility of implantation of tumor cells along the needle tract after percutaneous lung needle biopsy should be carefully considered in cases of carcinosarcoma.

Aged↗
PubMed1992

Penile metastasis from lung cancer.

A case of metastatic tumor of the penis from lung cancer is reported. The patient, who had received a right pneumonectomy 17 months previously for a squamous cell carcinoma of the lung, complained of urinary retention and painful erection of the penis. He underwent an emergency suprapubic cystostomy. Twenty days after the procedure, he died of disseminated lung carcinoma. The autopsy demonstrated massive metastasis to the penis from squamous cell carcinoma of the lung. Penile metastasis from lung cancer is a very rare condition and only 14 cases of this secondary carcinoma have been reported.

Aged↗
PubMed1992

Three-dimensional computed tomography image of small pulmonary lesions.

To evaluate diagnostic imaging of small lesions in the peripheral lung, three-dimensional (3D) reconstruction CT images were used to study 36 cases (including which had been 19 resected) of pulmonary nodules less than 3 cm in diameter. Rapid scanning was employed in 17 cases and helical scanning (in which the X-ray tube rotates continuously with simultaneous table sliding) in 19 cases. The rapid scanning could not be evaluated in two cases because respiratory motion resulted in discontinuous image data. We were able to evaluate 34 cases. The addition of 3D images to the conventional images made it possible for us to obtain useful information on visualizing relations between nodules and vascular structures in 32% (11/34) of the cases. The 3D images enabled us to visualize the lesions and pulmonary vessels three-dimensionally. It was, however, difficult to evaluate lesion shape since we were able to obtain useful information in only 3% (1/34) of the cases. In helical scanning, data are acquired from an extensive area within a short time, providing consecutive axial-slice images remain free of any respiratory artifacts. In this regard, helical scanning is suitable for generating 3D images. A diagnostic procedure based on 3D lesion analysis should be developed and standardized.

Aged↗
PubMed1992

Diagnosis of mediastinal lymph node metastases in lung cancer.

We studied CT and mediastinoscopy as methods for preoperatively diagnosing mediastinal lymph node metastases (N2) in 133 resected lung cancers, and determined the optimal criterion for a CT diagnosis based on node size. All 133 patients were examined with CT, with a resulting sensitivity of 57% and specificity of 81%. The optimal CT criterion for metastasis was a short node axis of greater than or equal to 10 mm. Where nodes with short axes of greater than or equal to 20 mm, for squamous cell carcinoma, and greater than or equal to 15 mm, for adenocarcinoma, were selected, 100% specificity was obtained. It can thus be considered that nodes of this size on CT show definite metastatic disease. Thirty-three patients who satisfied the selection criteria out of a total 80 patients underwent mediastinoscopy as a clinical trial, with a sensitivity of 70% and a specificity of 100%. Of these, the nine CT false positives (eight squamous cell carcinomas) and three out of the six CT false negative (all adenocarcinomas) were properly diagnosed. We compared 80 cases diagnosed as N2 by CT alone and by CT plus mediastinoscopy, and obtained the following results: accuracies of 67.5 and 82.5%, sensitivities of 54 and 67% and specificities of 73 and 89%, respectively, showing the addition of mediastinoscopy significantly to improve the diagnosis of N2 disease (P = 0.03). We now routinely include a mediastinoscopy except in cases where greatly enlarged nodes are visible on X-ray or in patients who are not candidates for neoadjuvant chemotherapy.

Adenocarcinoma↗
PubMed1992

An evaluation of serum microelement concentrations in lung cancer and matched non-cancer patients to determine the risk of developing lung cancer: a preliminary study.

In a case-control study to determine the risk of developing lung cancer, the serum levels of vitamins A and E, carotene and selenium were determined in 31 patients, newly diagnosed as having lung cancer, and in matched controls, the said controls being selected from outpatients with no cancer. A significant, inverse association was found between serum vitamins A and E and lung cancer. The relative risk for the low vs high tertiles were, respectively, 5.94 for serum vitamin A and 8.44 for serum vitamin E. Taking histological cancer subtype into account, no relation was revealed between the microelements and squamous cell carcinoma of the lung. The relative risk for lung cancer was 6.50, however, when three, or all four, microelement levels were in the lowest tertile, compared with there being fewer than three in the lowest tertile. Even when three microelements, excluding vitamin E which had the most significant inverse association with lung cancer, were considered, the relative risk was 7.50 when any two or all three were in the lowest tertile, compared with there being just one microelement or none at all in the lowest tertile. A combined effect of vitamins A and E, carotene and selenium on the development of lung cancer has, therefore, been suggested. Further studies will thus be necessary to elucidate the cumulative effect of the serum micronutrients and trace elements, as well as the effect of single elements, on the development of lung cancer.

Adenocarcinoma↗
PubMed1991

Operation of an efficient site-specific recombination system of Zygosaccharomyces rouxii in tobacco cells.

Recombinase encoded by the R gene of pSR1 of Zygosaccharomyces rouxii mediates reciprocal recombination between two specific recombination sites (RSs) to induce excision or inversion of the DNA segment that is flanked by the RSs. We report here that site-specific recombination mediated by this system takes place effeciently in tobacco cells. To monitor the recombination events in tobacco cells, we have constructed two types of cryptic beta-glucuronidase reporter gene in such a way that recombination such as inversion of the construct or excision of the intervening sequence results in their expression. When these cryptic reporter constructs were transiently introduced together with the R gene by electroporation into protoplasts of tobacco cells, beta-glucuronidase activity was detected. The cryptic reporter genes, when stably resident in the chromosome of tobacco cells, were also activated by the R gene. Structural analyses of the genomic DNA isolated from these tobacco cells showed that the R protein did in fact catalyze precise recombination between two copies of RSs in tobacco cells, with resultant activation of the cryptic reporter genes. This observation provides the basis for development of a DNA technology whereby large regions of DNA can be manipulated in plant chromosomes. Potential uses of this recombination system are discussed.

Base Sequence↗
PubMed1991

Determination of nonheme iron using inductively coupled plasma-atomic emission spectrometry.

A technique for the rapid and accurate estimation of nonheme iron using inductively coupled plasma-atomic emission spectrometry is described. Yttrium was used as an internal standard. An external calibration method was used. The standards were prepared in a matrix composed of 2.5N HCl in 10% (w/v) trichloroacetic acid. The supernatant and coagulum fractions of liver nonheme iron were separated by the method of Drysdale and Ramsay with minor modification. The data determined by this procedure was compared and found to be agreement with data determined by the method of Hallgren. To evaluate the iron status of rats, hemoglobin and liver nonheme iron were determined. Hemoglobin and all of the nonheme iron fractions of the rats fed an iron-deficient diet were significantly lower than those of the rats fed an iron-sufficient diet. The blood content in the liver was estimated to be 80 microL/g from the blood iron concentration, and the difference between total and nonheme iron concentration in liver.

Animals↗
PubMed1991

Effect of dietary iron deficiency on mineral levels in tissues of rats.

To clarify the influence of iron deficiency on mineral status, the following two synthetic diets were fed to male Wistar rats: a control diet containing 128 micrograms iron/g, and an iron-deficient diet containing 5.9 micrograms iron/g. The rats fed the iron-deficient diet showed pale red conjunctiva and less reactiveness than the rats fed the control diet. The hemoglobin concentration and hematocrit of the rats fed the iron-deficient diet were markedly less than the rats fed the control diet. The changes of mineral concentrations observed in tissues of the rats fed the iron-deficient diet, as compared with the rats fed the control diet, are summarized as follows: . Iron concentrations in blood, brain, lung, heart, liver, spleen, kidney, testis, femoral muscle, and tibia decreased; . Calcium concentrations in blood and liver increased; calcium concentration in lung decreased; . Magnesium concentration in blood increased; . Copper concentrations in blood, liver, spleen and tibia increased; copper concentration in femoral muscle decreased; . Zinc concentration in blood decreased; . Manganese concentrations in brain, heart, kidney, testis, femoral muscle and tibia increased. These results suggest that iron deficiency affects mineral status (iron, calcium, magnesium, copper, zinc, and manganese) in rats.

Animals↗
PubMed1991

Tumor invasion of the chest wall and mediastinum in lung cancer: evaluation with pneumothorax CT.

For preoperative evaluation of chest wall and mediastinal invasion by lung cancer, computed tomography (CT), combined with artificial pneumothorax (pneumothorax CT), was performed in 43 patients with lung cancer in whom conventional CT scans showed that the mass was contiguous to the chest wall (n = 30) and/or mediastinum (n = 25) but without evidence of definite tumor invasion. Invasion was diagnosed on the basis of whether an air space existed between the mass and the adjacent structures. In three patients pneumothorax was not produced. After the procedure, four patients developed symptomatic pneumothorax, and one, subcutaneous emphysema. Comparison of diagnoses based on findings at pneumothorax CT, surgery, and pathologic examination showed that pneumothorax CT is 100% accurate for chest wall invasion and 76% accurate for mediastinal invasion. The authors conclude that this procedure is helpful in accurate evaluation of the T criterion in lung cancer, especially for patients in whom findings at conventional CT suggest tumor invasion of the chest wall and mediastinum.

Adenocarcinoma↗