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Biomedical subjects

M Sakurai

Publications and source records attributed to M Sakurai.

At least 73 records · Page 4Linked to original sources
PubMed2001

Mitral exposure technique for redo cardiac surgery. A left mediastinal pleurotomy and minimal adhesiotomy method.

We report an improved mitral exposure technique for mitral valve re-operation. Left mediastinal pleurotomy through a median sternotomy achieves rotation of the heart and excellent exposure of the mitral valve allowing the apex to drop posteriorly. We employed this technique in redo mitral valve surgeries for over a 3-year period. This minimal adhesiotomy method is technically simple, safe and time-saving.

Humans↗
PubMed2001

Impact of pre-stent plaque debulking for chronic coronary total occlusions on restenosis reduction.

BACKGROUND: While stenting improves the long-term angiographic outcomes of successfully recanalized chronic coronary total occlusions (CTO), the restenosis rate still remains high. The massive plaque burden in CTO is considered to be one of the causes of in-stent restenosis. METHODS: We examined the pre-stent plaque debulking strategy with high-speed rotational atherectomy (RA) for 50 CTO (Thrombolysis in Myocardial Infarction flow grade 0; estimated occlusive duration, 3 months). Angiographic follow-up results were compared to those of 120 consecutive CTO recanalized with primary stenting in which RA could be indicated retrospectively. Angiographic restenosis was defined as diameter stenosis > 50% at 6-month follow-up. RESULTS: RA could be performed safely in all lesions without any major complications. Adjunctive ballooning and stenting could be performed without high-pressure dilatation (8.4 +/- 1.7 atmospheres). Follow-up angiography was performed in 48 lesions 184 +/- 61 days after the procedure. There were no significant differences in baseline characteristics between the two groups; however, the implanted stent type was different. Quantitative coronary angiography revealed that diameter stenosis was smaller at follow-up (36.2 +/- 20.0% versus 52.2 +/- 26.7%; p = 0.0003) as well as post-procedure (7.8 +/- 11.5% versus 17.8 +/- 13.6%; p < 0.0001) compared with the control group. Angiographic restenosis was also significantly reduced (29.2% versus 52.5%; p = 0.0061). CONCLUSIONS: RA is a safe procedure for plaque debulking of CTO in selected cases. Plaque debulking of CTO facilitates subsequent stent expansion and may reduce the restenosis rate.

Atherectomy, Coronary↗
PubMed2001

Investigation and evaluation of the change in the outpatients flow before and after the move of the hospital.

In order to estimate the changes in the service for outpatients with hospital movement, patient flow investigation has been performed at both old and new hospitals. IC memory card was handed out to each outpatient, and timestamps and places were recorded on the card at the places that the patient have been by using card writers set at each department. By comparing with two results, old and new hospitals, patient-waiting time at payment counter was remarkably shortened because of the effect of order-entry system. However, there were few changes in stay time at clinical departments. From the results, it is found that optimization of booking system was required for improvement of patients flow at clinical departments.

Appointments and Schedules↗
PubMed2001

[Retroperitoneal dedifferentiated liposarcoma extending into the iliocostal muscle and the quadratus lumborum muscle accompanied with bone formation: case report].

A 72-year-old man with back pain on the left side was admitted. Imaging analysis revealed a retroperitoneal mass and a mass in the left iliocostal muscle and the left quadratus lumborum muscle. The two masses could not be resected en bloc, and were resected separately. The clinicopathological findings of these tumors revealed dedifferentiated liposarcoma. The primary dedifferentiated liposarcoma appeared to have originated from the retroperitoneal space extending into the iliocostal muscle and the quadratus lumborum muscle. Then the mass was thought to have formed accompanied with osteogenesis.

Aged↗
PubMed2000

Glutamate 325 is a general acid-base catalyst in the reaction catalyzed by fructose-2,6-bisphosphatase.

A bifunctional enzyme, fructose-6-phosphate, 2-kinase:fructose-2, 6-bisphosphatase, catalyzes synthesis and hydrolysis of fructose 2, 6-bisphosphate. The phosphatase reaction occurs in two steps: the formation of a phosphoenzyme intermediate and release of beta-D-fructose 6-phosphate, followed by hydrolysis of the phosphoenzyme. The objective of this study was to determine whether E325 in the Fru 2,6-Pase active site is an acid-base catalyst. The pH-rate profile for k(cat) for the wild-type enzyme exhibits pK values of 5.6 and 9.1. The pH dependence of k(cat) for the E325A mutant enzyme gives an increase in the acidic pK from 5.6 to 6.1. Formate, acetate, propionate, and azide accelerate the rate of hydrolysis of the E325A mutant enzyme, but not of the wild-type enzyme. Azide and formate, the smallest of the weak acids tested, are the most potent activators. The k(cat) vs pH profile of the E325A mutant enzyme in the presence of formate is similar to that of the wild-type enzyme. Taken together, these data are consistent with E325 serving an acid-base role in the phosphatase reaction. The exogenous low MW weak acids act as a replacement general base in the hydrolysis of the phosphoenzyme intermediate, rescuing some of the activity lost upon eliminating the glutamate side chain.

Alanine↗
PubMed2000

Neonatal (cord blood) T cells can competently raise type 1 and 2 immune responses upon polyclonal activation.

In the neonate, cellular immunity has generally been hypothesized as being incompetent. Accumulating evidence from several recent studies, together with our present report, contradicts this hypothesis. T-helper cell and T cytotoxic type 1 and 2 (Th1/Th2 and Tc1/Tc2, respectively) cytokine responses to polyclonal T cell receptor (TCR) activation were assessed in medium-term cultures of human cord blood T cells using intracellular cytokine staining, which could measure the frequencies of cytokine-producing cells. In this study, we examined the responses of cord blood CD4(+) and CD8(+) T cells in regard to the production of interferon (IFN)-gamma and interleukin (IL)-4 and compared the responses with those obtained from T cells of healthy adults. We found that the responses in cord blood T cells activated with TCR stimulation were comparable to those of their adult counterparts. Moreover, the Th/Tc cells that developed in cord blood were as competent as adult cells for both IFN-gamma and IL-4 secretion. In addition, IL-12 production, which is critical for both Th1 and Tc1 responses, was equally comparable in the two groups. The production of two major cross-regulatory cytokines, tumor necrosis factor-alpha and IL-10, was similarly comparable and not significantly different between the two groups. Taken together, these results indicate that, though naive, the neonatal T cell is competent to respond to TCR-mediated stimulation and to produce both type 1 and type 2 cytokines.

Adult↗
PubMed2000

Demonstration of MDR1 P-glycoprotein isoform expression in benign and malignant human prostate cells by isoform-specific monoclonal antibodies.

Prostate cancers are resistant to many anticancer agents at the time of presentation. P-glycoprotein (P-gp) is believed to mediate multidrug resistance phenotype. To elucidate the possible role of P-gp in such an intrinsic drug resistance of prostate cancers, its expression was examined immunohisochemically using two P-gp isoform-specific monoclonal antibodies (mAbs) with the paraffin embedded prostate samples derived from five nonmalignant and 30 untreated prostate cancer patients. In all of five normal prostate tissues, P-gp was consistently detected with both mAbs in the epithelial cells, especially at their apical site, and the level of expression was higher in the inner zone than in outer zone. On the other hand, tumor cells expressed P-gp heterogeneously in distribution and intensity; in 25 of 30 malignant cases P-gp expression was clearly demonstrated, whereas its expression was only faintly detected in other cases. However, the staining intensities for P-gp in prostate cancer cells were generally lower than in normal prostate epithelial cells. Thus, not only normal prostate epithelial cells but prostate cancer cells express at least MDR1 P-gp isoform. These results suggest that P-gp expression might play some role in intrinsic drug resistance of prostate cancer cells to many cytotoxic drugs as well as in relative resistance of the inner zone cells to the prostate carcinogenesis.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed2000

Cold denaturation of alpha-lactalbumin.

We have investigated the thermal unfolding of bovine alpha-lactalbumin by means of circular dichroism spectroscopy in the far- and near-ultraviolet regions, and shown that the native alpha-lactalbumin undergoes heat and cold denaturation. The guanidine hydrochloride-induced unfolding of alpha-lactalbumin was also investigated by circular dichroism spectroscopy at various temperatures from 261 to 318 K. It is shown that the population of the molten globule state is strongly dependent on temperature and that the molten globule state does not accumulate during the guanidine hydrochloride-induced unfolding transition at 261 K. Our results indicate that the molten globule state of alpha-lactalbumin undergoes cold denaturation as the native alpha-lactalbumin does, and that the heat capacity change of unfolding from the molten globule to the unfolded state is positive and significant. The present results further support the idea that the molten globule and the unfolded states do not belong to the same thermodynamic state, and that the native, molten globule and unfolded states are sufficient for interpreting the guanidine hydrochloride-induced unfolding behavior of alpha-lactalbumin.

Animals↗
PubMed2000

Jugular foramen syndrome caused by varicella zoster virus infection in a patient with ipsilateral hypoplasia of the jugular foramen.

We report a patient with acute cranial polyneuropathy with unilateral involvement of the ninth, tenth, and eleventh cranial nerves. Although this patient lacked a typical cutaneous herpetic manifestation, elevated levels of IgM and IgG antibodies to varicella zoster virus (VZV) in both the serum and cerebrospinal fluid confirmed the clinical diagnosis of VZV infection and zoster sine herpete. Coexisting hypoplasia of the ipsilateral jugular foramen was detected using three-dimensional, surface-rendering displays reconstructed from the cranial helical CT scan. The patient recovered almost completely following treatment with an anti-inflammatory corticosteroid. Anatomical narrowing of the jugular foramen in this patient may have contributed to entrapment of the affected nerves at their passage through the foramen.

Accessory Nerve↗
PubMed2000

Percutaneous myocardial ablation in double-chamber right ventricle.

Double-chamber right ventricle (DCRV) exhibits intracavitary outflow obstruction. We report the first case of percutaneous myocardial ablation of DCRV in a 73-year-old patient. An alcohol-induced conus branch occlusion provided the reduction of pressure gradient from 81 to 48 mm Hg and clinical improvement. This strategy may be an alternative therapy to surgery in the adult patients with DCRV. Cathet. Cardiovasc. Intervent. 49:97-101, 2000.

Aged↗
PubMed2000

Detection of congenital malaria by polymerase-chain-reaction methodology in Dar es Salaam, Tanzania.

The examination of congenital malaria was performed by Giemsa staining and polymerase-chain-reaction (PCR) methodology. We randomly selected 298 neonates who had been admitted to Muhimbili Medical Center (MMC) at Dar es Salaam, Tanzania. One baby among all the enrolled neonates was recognized as having a congenital malaria infection, which gave a prevalence of 0.33%. The present result was 5-fold the clinically recognized prevalence of congenital infection with malaria in the ward. The PCR method identified two cases, one of which was negative as determined by the Giemsa-staining method. Therefore, the PCR method was useful for the detection of scant amounts of malarial parasites in numerous blood samples. The screening of malaria by a sensitive PCR method contributes to reduce the mortality of asymptotic neonates in particular.

Gestational Age↗
PubMed2000

Intracellular cytokine profile of T cells from children with acute lymphoblastic leukemia.

PURPOSE: During an ongoing immune response, cytokines produced by T helper types 1 (Th1) and 2 (Th2) together with T cytotoxic types 1 (Tc1) and 2 (Tc2) are critical to the effectiveness of that response. Dysregulated expansion of one or the other subset may contribute to the impaired function of the T-cell-mediated immune system in cancer patients. In the present study we have investigated whether such dysregulation might exist in children with acute lymphoblastic leukemia (ALL). METHODS: We analyzed 61 blood samples from 45 children with B cell precursor ALL and 16 healthy children. Interleukin(IL)-2, IL-4, and interferon gamma (IFN gamma) production of their respective purified CD4+ and CD8+ T cells were assessed at the single-cell level by intracellular-cytokine-staining flow cytometry. RESULTS: At the time of diagnosis, IL-2-producing cell populations in CD4+ and CD8+ T cells were reduced below the normal range in 31 of 44 (70.5%) and 23 of 38 (60.5%) cases respectively. Similarly, IFN gamma-producing cell populations in CD4+ and CD8+ T cells decreased in 17 of 44 (38.6%) and 18 of 38 (47.4%) cases respectively. Conversely cell populations capable of IL-4 production in CD4+ and CD8+ T cell subsets were increased in 13 of 30 (43.3%) and 15 of 30 (50.0%) cases respectively. Therefore, the Th1-to-Th2 and Tc1-to-Tc2 ratios (1.6 +/- 2.2 and 7.7 +/- 6.7 respectively) were significantly lower in peripheral blood T cells of ALL patients (n = 30) than those (6.0 +/- 2.9 and 20.1 +/- 10.3 respectively) in 15 healthy controls (P < 0.0001). Although both CD45RA+/CD4+ and CD45RA+/CD8+ cells significantly increased in 43 ALL patients (P < 0.05), there existed no apparent correlation between CD45 isoform expression and cytokine (IL-2 and IFN gamma) production. Interestingly, the ability to produce both IL-2 and IFN gamma was recovered in 8 cases examined, after complete remission had been achieved. CONCLUSION: These observations suggest that, in both CD4+ and CD8+ T cells of ALL patients, there is a dysregulation in the functionality of Th1 (Tc1) and Th2 (Tc2) cells with a gross reduction of Th1 (Tc1) cell populations and an expansion in Th2 (Tc2).

Adolescent↗
PubMed2000

Bilateral choroidal metastases secondary to uterocervical carcinoma of the squamous cell type.

PURPOSE: To report a patient with bilateral choroidal metastases secondary to uterocervical carcinoma of the squamous cell type. METHODS: Case report. RESULTS: A 55-year-old woman complained of visual field loss and decreasing vision. Seven months earlier, uterocervical carcinoma of the squamous cell type was diagnosed and treated with chemotherapy and irradiation. Serous retinal detachment and choroidal masses were present in both eyes. Retinal detachment was lessened in both eyes after radiotherapy. The patient died of respiratory insufficiency 3 months after the appearance of choroidal metastases. At autopsy, there was no second cancer to cause the choroidal metastases. Tumor embolization was present in the choriocapillaries. CONCLUSION: Choroidal metastasis may develop from hematogenous spread of uterocervical squamous cell carcinoma.

Carcinoma, Squamous Cell↗
PubMed2000

Optic disk pallor and retinal atrophy in Sotos syndrome (cerebral gigantism).

PURPOSE: To report a case of Sotos syndrome (cerebral gigantism) with megalophthalmos, optic disk pallor, and retinal atrophy. METHODS: Case report. RESULTS: A 22-year-old man was diagnosed with Sotos syndrome with optic atrophy. His corneal diameters were 13 mm horizontally, and his optic disks were pale. His retinal vessels were attenuate in diameter, and small white spots were found on the retina. The results of a Goldmann visual field test were normal. His visually evoked potential to flash stimuli showed extended latent times and normal amplitudes. Keratometry was 40.5 diopters (8.33 mm) in both eyes. The axial length was 25.9 mm in the right eye and 25.4 mm in the left eye. CONCLUSION: Sotos syndrome may be associated with optic disk pallor and retinal atrophy.

Abnormalities, Multiple↗
PubMed2000

Deep circumflex iliac artery as a free arterial graft for myocardial revascularization.

When complete revascularization cannot be obtained with the internal thoracic artery and the other arterial grafts, the deep circumflex iliac artery (DCIA) may be an excellent alternative conduit. The deep circumflex iliac artery was used as a free graft for direct myocardial revascularization in 4 patients from January to July 1999. We describe our experience with this arterial conduit, review the anatomy of the artery, and present our harvesting technique.

Coronary Angiography↗
PubMed2000

Modulated vasodilator responses to natriuretic peptides in rats exposed to chronic hypoxia.

Natriuretic peptides (NPs), such as atrial natriuretic peptide (ANP), C-type natriuretic peptide (CNP), and adrenomedullin (ADM), are endogenous vasodilators acting via specific receptors. This study addressed the question of how pulmonary artery (PA) responses to these peptides and the gene expression of their receptors are modulated in pulmonary hypertension rat models exposed to chronic hypoxia. In this study, isometric tension was measured in PA rings exposed to these NPs and 8-bromoguanosine 3', 5'-cyclic monophosphate (8-bromo-cGMP). It was compared with messenger ribonucleic acid (mRNA) levels of NP-A and -B receptors, which bind to ANP and CNP, respectively, as determined by ribonuclease (RNase) protection assay. Chronic hypoxia increased the maximal relaxation elicited by ANP, but the responses to CNP and 8-bromo-cGMP were unchanged. Chronic hypoxia did not change NP-A and -B receptor mRNA levels. The results showed that pulmonary artery response to atrial natriuretic peptide is selectively enhanced, possibly via a post-transcriptional modulation of its receptor in chronically hypoxia rats. These pharmacological characteristics of atrial natriuretic peptide are consistent with the hypothesis that the atrial natriuretic peptide system is protective against the progression of pulmonary hypertension.

Adrenomedullin↗