Biomedical subjects
Publications and source records attributed to H Tashiro.
The contact-free, non-invasive manipulation provided by optical trapping enables us not only to measure physical parameters of individual cells but also to initiate specific responses in a given cell in a defined environment.
As major determinants of cell shape and polarity, microtubules are required to have suitable rigidity. However, our knowledge of the mechanical properties of microtubules is far from satisfactory. We report here a new method of measuring the flexural rigidity of a single microtubule by direct buckling using the optical trapping technique. Microtubule buckling was induced by applying a small longitudinal compressing force through an optically trapped microsphere that was firmly attached to the microtubule. Three ways of estimating the flexural rigidity of a continuous slender rod, one from the observed critical load of buckling and two from deflected lengths and angles of bending, yielded values which agreed well when applied to the analysis of buckling microtubules. Unexpectedly, we found that the rigidity was not constant as expected but was dependent on microtubule length. This length dependency explains the discrepancies among reported values of microtubule flexural rigidity measured by different methods. Comparing microtubules of identical lengths, microtubules assembled with brain-derived associated proteins (4 x 10(-23) Nm2 at around 10 microns in length) were four times more rigid than those assembled from purified tubulin and stabilized with taxol (1 x 10(-23) Nm2).
Fulminant hepatic failure is usually fatal without liver transplantation; however, orthotopic liver transportation is often difficult to perform due to the high risk of coagulopathy and the development of multiple organ failure. Auxiliary heterotopic partial liver transplantation (APLT), However, has the potential to provide an effective hepatic support system considering that the host liver is left in situ and the surgical procedure is less invasive. In this report, we describe the beneficial effects of performing 60% APLT on the hepatic function and survival of pigs with acute hepatic failure induced by hepatic artery ligation. The pigs were divided into a control group of nine animals (group 1) that had portal vein and hepatic artery ligation with a side-to-side portacaval shunt, and an APLT group of seven animals (group 2) that had portal vein and hepatic artery ligation with APLT. The two left lateral lobes of the donor liver were resected, reducing the liver weight to about 60%, and the graft was placed in the right subhepatic space. No deaths occurred intraoperatively. In group 1, eight pigs died of massive liver necrosis within 48 h and one died between 48 and 72 h (median survival 23 h). In group 2, two pigs died within 72 h due to preservation or anesthetic problems, but five survived for more than 3 days (median survival 13.4 days), with a significant difference between the two groups (P < 0.05). One animal was killed 30 days after APLT and excellent graft function was demonstrated by the synthesis of clotting factors, ammonia detoxification, and glucohomeostasis. Moreover, evidence of hepatic regeneration was found in the transplanted livers.(ABSTRACT TRUNCATED AT 250 WORDS)
Longer survival data are necessary to elucidate the prognostic factors for survival in advanced breast cancer patients. Univariate and multivariate analyses were performed in 159 patients treated with adreno-oophorectomy alone as the first-line treatment for advanced or recurrent breast cancer, between 1972 and 1983. Nine clinical factors included age, menopausal status, estrogen (ER)- and progesterone receptors (PgR) in recurrent tumors, disease-free interval (DFI), number of metastatic organs, performance status, and adjuvant therapy performed. Response was evaluated according to the UICC criteria. A 31% (50/159) response with 16 CR, 34 PR, 48 NC, and 61 PD was obtained. The logistic regression model of the factors showed that ER was the single affecting factor for the response. According to the Cox proportional hazard model, ER and the dominant site of metastasis were indicated to be significant for survival. According to the landmark method, the response significantly correlated to survival. Using the backward elimination procedure of the Cox proportional hazard model in the patient group defined by the landmark time of 3 months after therapy, the survival of the patients with advanced breast cancer was shown to be primarily influenced by the tumor response which was solely affected by ER status, and the dominant site, particularly the presence of liver metastasis, independently modified the survival length. These results may be useful in future studies of total estrogen blockade trials for breast cancer.
Active oxygen species generated by circulating leukocytes and released from the gastric mucosa were measured in the process of acute gastric mucosal lesion formation after thermal injury in rats. Alterations of luminol-dependent chemiluminescence activities generated by leukocytes obtained from the gastric vein and the inferior vena cava were approximately same. A decrease in chemiluminescence activity 15 min after thermal injury and a significant increase in chemiluminescence activity 5 hr after thermal injury were observed in leukocytes from both veins. From 15 min to 12 hr after thermal injury, luciferin-dependent chemiluminescence activities were significantly higher than that of the control group. Oral administration of rebamipide resulted in decreased mucosal lesion formation. Rebamipide, an antiulcer agent that protects the mucosa from damage in various animal models decreased chemiluminescence activities only released from the gastric mucosa but not from circulating leukocytes. These results suggest that two different pathways of active oxygen species formation may exist in the pathogenesis of acute gastric mucosal lesions after thermal injury.
1. Growth cones of cultured dorsal root ganglion neurons from mice were irradiated using a mercury lamp. 2. The flux of particles of fast retrograde axoplasmic transport decreased promptly after light irradiation without a change in velocity. 3. That of anterograde transport decreased as well, but with a significant latency. The decrease in anterograde flux was attributed to decreased velocity of particles. 4. Video-enhanced contrast microscopy of growth cones revealed transient swelling of growth cones and transient stagnation of particles in growth cones. 5. The longer the neurite, the larger the latency of the change of the anterograde transport; peripheral information was calculated to be conveyed to the cell body at a speed of 6 microns/min. 6. The mechanism of this information conveyance and the export of materials from the cell body are discussed.
Echocardiography was performed before and after treadmill tests in 30 patients to determine whether there is temporal variability in left ventricular wall motion abnormality with exercise-induced ischemia. The extent of wall motion was assessed by calculating systolic shortening in endocardial motion by two methods: (1) comparison between end diastole and end systole (ED-ES) and (2) frame-by-frame analysis throughout systole (integration). The extent of myocardial ischemia was assessed by stress thallium 201 emission tomography. Sensitivity of echocardiography for diagnosis of ischemia was 62% by ED-ES, but it increased to 83% by the integration method. Twenty-one percent of the ischemic area showed wall motion abnormality solely in the middle of systolic phase but not at end systole, and this occurred more at the reversible ischemic area (31%) than at the persistent ischemic area (19%). In conclusion, analysis throughout systole is important in detecting a reversible ischemic area.
To elucidate the role of monocytes in the cytokine system in acute myocardial infarction (AMI), we examined the time courses of plasma concentrations and generation capacities of monocyte-related cytokines in 17 consecutive patients with uncomplicated AMI (from day 1 to 28) and in 10 control subjects. The concentrations of monocyte-related cytokines were measured by enzyme immunoassay with horseradish peroxidase. Cytokine generation capacity was evaluated by cytokine concentrations in the culture solution 24 hours after incubation of 0.5 ml whole blood with 5 micrograms lipopolysaccharide. Two distinct patterns of increases in the cytokine concentrations were noted: transient (plasma interleukin [IL]-6) and sustained (plasma macrophage colony-stimulating factor and generation capacities of IL-1 alpha, IL-6, granulocyte colony-stimulating factor, and tumor necrosis factor alpha). There was no significant increase in the concentrations of other cytokines. These results indicate that the concentrations of the monocyte-related cytokines dynamically change during the course of AMI, suggesting that they may contribute to the inflammatory and subsequent proliferative responses in AMI.
PURPOSE: This study evaluated the effectiveness of marsupialization for the treatment of cystic ameloblastoma. MATERIALS AND METHODS: Clinical and histologic examination of 24 cystic ameloblastomas were performed before and after marsupialization. RESULTS: Clinically and radiographically, the effect of marsupialization was evaluated as extremely effective (five cases), effective (11 cases), and noneffective (eight cases). Marsupialization was most effective in teenaged patients. In three cases, the tumor disappeared macroscopically, and further surgery was not done. Histologically, the growth characteristics of the tumor were classified into expansive and invasive types. Cytologic pattern was classified into three types according to the outer cell layer of the tumor parenchyme: cuboidal cell, columnar cell, and basal cell. Premarsupialization, the expansive pattern with the cuboidal cell type was dominant, whereas for postmarsupialization many cases that had been expansive changed to an invasive type showing columnar or basal cell types. CONCLUSION: Marsupialization was found to be useful as a preliminary treatment of the cystic ameloblastoma. However, it must be borne in mind that following marsupialization the tumor still has a potential to infiltrate into the surrounding tissues.
The polymerase chain reaction (PCR) using primers specific for the rat Y-chromosome gene made it possible to distinguish a very small number of male rat cells from a large excess of female rat cells. In nonimmunosuppressed LEW recipients of ACI liver allografts, the donor cells in the bloodstream disappeared rapidly by day 3, earlier than the biochemical changes indicative of liver dysfunction. In immunosuppressed LEW recipients of ACI liver allografts, the donor cells were detected for a longer time. Moreover, in LEW recipients surviving for long period, the PCR revealed mixed-microchimerism. Our results indicated that this Y chromosomal gene-specific PCR method is useful for assessing engraftment following rat liver transplantation.
Cytochrome c oxidase of the thermophilic bacterium, PS3, was treated with trypsin. The hydrophilic domain of 26 kDa can be easily cleaved off from the hydrophobic anchor domain at the N-terminal region of subunit II, but remains attached to the rest of the enzyme upon gel-filtration in the presence of 0.2% lauroyl sarcosinate. The separation occurred in the presence of 5 M urea in addition to 0.2% lauroyl sarcosinate. After relatively prolonged proteolysis, that induced severe activity decay, and subunit I fragmentation, the 26 kDa fragment of subunit II can be easily isolated from the rest, suggesting that this fragment with cytochrome c and CuA interacts with subunit I. The separated fragment showed absorption spectra due to CuA and cytochrome c. Reconstitution of the cytochrome oxidase activity occurred on addition of the 26 kDa fragment to the proper gel-filtration chromatographic fraction.
Sixty-five living related kidney transplant pairs were analyzed for matching at HLA class II loci by the polymerase chain reaction (PCR)--sequence specific oligonucleotide probe (SSOP) method. The retrospective HLA matching study revealed that there were many early graft loss cases despite the DQB compatibility, contrary to our expectation. There were 54 DRB1 one-mismatched cases, in which 7 of the 11 (64%) DQB zero-mismatched cases had lost their grafts, while the graft loss cases were only 10 of the 43 (23%) DQB one-mismatched pairs (P value = 0.0006). The DQB matching of these cases was studied in detail, because the PCR-SSOP methods are based on the detection of sequence polymorphisms in a relatively narrow range, i.e., recognized sequences by SSOPs. The PCR--heteroduplex--polymorphism analysis method was developed to analyze the polymorphism in exon 2 of the DQB1 gene. However, all the pairs proved to be compatible for the DQB, demonstrating that the DQB compatibility was associated with a harmful influence on the graft outcome. These observations suggested that the DQB1 incompatibility might exert the low responsiveness to HLA haplo-identical allogeneic transplants.
Nineteen giant cell tumors of tendon sheath (GCTTS) were studied to elucidate the origin of the proliferating cells of these tumors, using single and multiple immunostaining techniques with a labeled avidin-biotin [LAB] method in paraffin-embedded tissues. Proliferating cell nuclear antigen (PCNA) and Ki-67 (MIB-1) antigen were present in mononuclear cells (PCNA 26%; MIB-14%) but were absent in giant cells. These findings indicate that mononuclear cells, but not giant cells, participate in the proliferative compartment of GCTTS. A histiocytic marker, HAM56, was positive in many mononuclear cells (mean 81%), but was totally negative in osteoclastic giant cells. Another histiocytic antigen, CD68, was expressed in both mononuclear cells (mean 28%) and most of the giant cells (mean 89%). By triple immunostaining for PCNA, HAM56 and vimentin, 83% of PCNA-positive mononuclear cells co-expressed HAM56. Because of the frequent co-expression of PCNA and HAM56, the main portion of proliferating cells in GCTTS may represent a monocyte/macrophage lineage. However, there is a small but definite mesenchymal/fibroblastic component, characterized by PCNA+vimentin+HAM56-, relating to the proliferative compartment of GCTTS. Multiple immunostainings with MIB-1 showed similar patterns to those with PCNA. These observations indicate that the GCTTS represent bimodal proliferative lesions consisting of histiocytic and mesenchymal/fibroblastic elements.
PURPOSE: To determine the accuracy of transvaginal ultrasound (TVUS) and of precontrast and contrast material-enhanced magnetic resonance (MR) imaging in the differentiation of adnexal masses. MATERIALS AND METHODS: Five blinded readers analyzed images of 80 masses in 72 patients. MR and TVUS images were interpreted in separate sessions. Findings were confirmed at surgery or laparoscopy. RESULTS: Higher diagnostic accuracy was attained with MR imaging in mature cystic teratomas and endometriomas. However, better accuracy was achieved with contrast-enhanced MR imaging and TVUS in simple cysts, cystadenomas, and malignant tumors because internal details could be visualized. Receiver operating characteristic study indicated that observer confidence was significantly higher with contrast-enhanced MR imaging than with precontrast MR imaging (P = .011) or TVUS (P = .002) in the differentiation of benign and malignant masses. CONCLUSION: Contrast-enhanced MR imaging is superior to precontrast MR and TVUS imaging in the characterization and differentiation of adnexal masses.
The focus of this study was an analysis of maxillary arch growth changes prior to the time of cheiloplasty up to 4 years of age. Serial dental casts were obtained and measured in 95 children with cleft lip and palate, or both: 7 unilateral cleft lip and alveolus (CLA), 52 unilateral cleft lip and palate (UCLP), 24 bilateral cleft lip and palate (BCLP), and 12 isolated cleft palate (CP). The children were treated at the Kyushu University Dental Hospital. The results are as follows: (1) Prior to cheiloplasty, the maxillary buccal segments in the subjects with cleft lip and palate showed lateral displacement. The premaxilla in BCLP subjects was protruded. (2) Cheiloplasty influenced maxillary anterior arch width, but not posterior width. The operation caused posterior displacement of the premaxilla in BCLP subjects. (3) Palatoplasty affected the growth of the maxillary arch in the transverse and anteroposterior dimensions. (4) A variety of growth patterns observed in the patients (e.g., increasing or decreasing of the maxillary arch dimensions) suggests that maxillary arch dimensions were affected not only by surgery, but also by other individual factors such as genetic facial pattern and severity of the cleft.
Craniofacial morphology was compared in 10 patients with unilateral cleft lip and alveolus (UCLA), 33 with complete unilateral cleft lip and palate (UCLP), and 14 patients with isolated cleft palate (CP). Serial lateral and posteroanterior cephalograms, obtained just before lip repair at 4 months or palatoplasty at 2 years, and at 4 and 8 years of age, were analyzed through comparisons with the means and growth increments of craniofacial dimensions. Facial forms at 8 years of age were compared with those of 33 noncleft subjects. Wider upper facial width before lip repair in the UCLP patients diminished slightly following surgery, but the condition persisted up to 8 years of age. Less forward growth of the maxilla was found in the subjects who received palatoplasty and a larger vertical growth increment in anterior maxilla occurred in the UCLP patients. Posterior maxillary height showed no significant differences in its growth increment among patients with clefts, but shorter posterior maxillary height in the UCLP patients continued. Linear dimensions of the mandible did not differ among cleft subjects, but a larger intercondylar width, a larger gonial angle, and a slightly retruded mandible in the CP patients and UCLP patients suggested compensation of the mandible to a wider and retroinclined nasomaxillary complex.
Differential-interference-contrast microscopy with video enhancement displayed the movement of particles for the first time in the isolated axonic process of cone-type photoreceptor cells of Rana catesbiana. This movement was observed under visible light which visual pigments could absorb. The number of retrograde moving particles in an arbitrary area on the axonic process was twice that of those moving in the anterograde direction. The mean velocities were 1.03 +/- 0.55 microns/sec for anterograde particles and 0.41 +/- 0.30 microns/sec for retrograde particles, which are of the same order as those found in isolated neurons.
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