Shape Changes in the Mirror Nuclei

We studied the proton-rich T_{z}=-1 nucleus ^{70}Kr through inelastic scattering at intermediate energies in order to extract the reduced transition probability, B(E2;0^{+}→2^{+}). Comparison with the other members of the A=70 isospin triplet, ^{70}Br and ^{70}Se, studied in the same experiment, shows a 3σ deviation from the expected linearity of the electromagnetic matrix elements as a function of T_{z}. At present, no established nuclear structure theory can describe this observed deviation quantitatively. This is the first violation of isospin symmetry at this level observed in the transition matrix elements. A heuristic approach may explain the anomaly by a shape change between the mirror nuclei ^{70}Kr and ^{70}Se contrary to the model predictions.

Metastable States of

Here we present new information on the shape evolution of the very neutron-rich ^{92,94}Se nuclei from an isomer-decay spectroscopy experiment at the Radioactive Isotope Beam Factory at RIKEN. High-resolution germanium detectors were used to identify delayed γ rays emitted following the decay of their isomers. New transitions are reported extending the previously known level schemes. The isomeric levels are interpreted as originating from high-K quasineutron states with an oblate deformation of ß∼0.25, with the high-K state in ^{94}Se being metastable and K hindered. Following this, ^{94}Se is the lowest-mass neutron-rich nucleus known to date with such a substantial K hindrance. Furthermore, it is the first observation of an oblate K isomer in a deformed nucleus. This opens up the possibility for a new region of K isomers at low Z and at oblate deformation, involving the same neutron orbitals as the prolate orbitals within the classic Z∼72 deformed hafnium region. From an interpretation of the level scheme guided by theoretical calculations, an oblate deformation is also suggested for the ^{94}Se_{60} ground-state band.

Gamma Decay of Unbound Neutron-Hole States in

Excited states in the nucleus ^{133}Sn, with one neutron outside the double magic ^{132}Sn core, were populated following one-neutron knockout from a ^{134}Sn beam on a carbon target at relativistic energies at the Radioactive Isotope Beam Factory at RIKEN. Besides the γ rays emitted in the decay of the known neutron single-particle states in ^{133}Sn additional γ strength in the energy range 3.5-5.5 MeV was observed for the first time. Since the neutron-separation energy of ^{133}Sn is low, S_{n}=2.402(4) MeV, this observation provides direct evidence for the radiative decay of neutron-unbound states in this nucleus. The ability of electromagnetic decay to compete successfully with neutron emission at energies as high as 3 MeV above threshold is attributed to a mismatch between the wave functions of the initial and final states in the latter case. These findings suggest that in the region southeast of ^{132}Sn nuclear structure effects may play a significant role in the neutron versus γ competition in the decay of unbound states. As a consequence, the common neglect of such effects in the evaluation of the neutron-emission probabilities in calculations of global ß-decay properties for astrophysical simulations may have to be reconsidered.

Shape Evolution in Neutron-Rich Krypton Isotopes Beyond N=60: First Spectroscopy of

We report on the first γ-ray spectroscopy of low-lying states in neutron-rich ^{98,100}Kr isotopes obtained from ^{99,101}Rb(p,2p) reactions at ∼220 MeV/nucleon. A reduction of the 2_{1}^{+} state energies beyond N=60 demonstrates a significant increase of deformation, shifted in neutron number compared to the sharper transition observed in strontium and zirconium isotopes. State-of-the-art beyond-mean-field calculations using the Gogny D1S interaction predict level energies in good agreement with experimental results. The identification of a low-lying (0_{2}^{+}, 2_{2}^{+}) state in ^{98}Kr provides the first experimental evidence of a competing configuration at low energy in neutron-rich krypton isotopes consistent with the oblate-prolate shape coexistence picture suggested by theory.

Induction of cells with phenotypic features of neuronal cells by treatment with dibutyryl cyclic adenosine 3',5'-monophosphate in a human parotid gland adenocarcinoma cell line in culture.

A human parotid gland adenocarcinoma cell line, with an intercalated duct cell phenotype of the salivary gland and expression of vasoactive intestinal polypeptide and amylase, was cultivated in the presence of dibutyryl cyclic adenosine 3',5'-monophosphate (dB-cAMP). Morphological changes occurred; cells formed long cytoplasmic processes densely packed with ample microfibrils, as well as microtubules, and grew in a netlike appearance. In addition, it has been found by the immunofluorescence staining technique, immunoblotting, or immunoelectron microscopy that the cells treated with dB-cAMP express neurofilaments, neuron-specific enolase, synaptophysin, and HNK-1 antigen, as well as the alpha- and beta-chains of tubulin, whereas these antigens are not detected in untreated cells. The expression of vasoactive intestinal polypeptide detected diffusely in the cytoplasm of untreated cells was restricted to the cell membranes during the cultivation of cells in the presence of dB-cAMP, while expression of amylase persisted in the treated cells in a fashion similar to that in untreated cells. Moreover, both anchorage-independent and anchorage-dependent growth of the cells was markedly suppressed in the presence of dB-cAMP. After removal of dB-cAMP from the culture, the treated cells returned rapidly to the phenotype and growth rate of the untreated cells. These findings indicate that reversible conversion into cells with phenotypic features of neuronal cells of a human parotid adenocarcinoma cell line occurs in growth medium containing dB-cAMP.

Effects of retinoic acid on morphological features and biological markers of a neoplastic human salivary intercalated duct cell line in culture.

Retinoic acid has marked effects on the growth, morphological features, and biological markers of a neoplastic human salivary intercalated duct cell clone in culture, whereas the cell clone was not affected by other retinoids such as retinol and retinal. A cell clone with ultrastructure and biological markers specific to the intercalated duct cells of human salivary glands was cultivated in the presence of retinoic acid. Major alterations, such as expression of tonofilaments, Mr 68,000 cytokeratin, and involucrin, were observed in those cells with a phenotype similar to that of keratinizing squamous cells. In addition, the coexpression of Mr 68,000 cytokeratin and carcinoembryonic antigen in these altered cells was found. Both the anchorage-independent and anchorage-dependent growths were markedly suppressed in the presence of retinoic acid. After the removal of retinoic acid from the culture, the treated cells returned rapidly to the phenotype of the untreated cells. These findings indicate that reversible differentiation into the keratinizing squamous cells of a neoplastic human salivary intercalated duct cell clone occurs in growth medium containing retinoic acid.

Expression of neurofilaments in a neoplastic human salivary intercalated duct cell line or its derivatives and effect of nerve growth factor on the cellular proliferation and phenotype.

A neoplastic salivary cell line with an ultrastructure similar to that of an intercalated duct cell of the salivary gland, established from a human submandibular salivary gland, has been used in our laboratory as a model for studying mechanisms regulating cytodifferentiation in salivary glands. The expression of neurofilaments (Mr 200,000, 160,000, and 68,000) in the neoplastic human salivary intercalated duct cell line and its derivatives was found by the immunofluorescence staining technique, immunoblotting, or immunoelectron microscopy. In addition, these cells stained with Bodian impregnation and expressed specific antigens such as tubulin alpha and beta chain, HNK-1 antigen, and laminin. When these cells were cultured in the presence of nerve growth factor, only the cells with a myoepithelial cell phenotype formed the long cytoplasmic processes which were densely packed with ample microfibrils in addition to microtubule bundles, and they exhibited marked suppression of anchorage-independent and anchorage-dependent growths. These findings indicate that the characteristics of neoplastic human salivary intercalated duct cell line and its derivatives are similar to those of neuronal cells.

A clinical trial of allopurinol (Zyloric) for myocardial protection.

This study explored myocardial protective effects of allopurinol at various doses. Ninety patients undergoing coronary artery bypass or repair or replacement of cardiac valves were divided into three groups of 30 patients each in accordance with the amount of allopurinol administered to patients in each group. Patients in group I received no allopurinol, those in group II received low-dose allopurinol (total dose 1200 mg), and those in group III received high-dose allopurinol (total dose 2400 mg). Aspartate aminotransferase, cardiac isoenzyme of creatine kinase, and lactic dehydrogenase levels were measured up to 5 days after operation. Concentrations of allopurinol and oxypurinol were also measured before initiation of cardiopulmonary bypass and at the start and at the end of aortic crossclamping. Postoperative aspartate aminotransferase, creatine kinase, and lactate dehydrogenase 1 plus lactate dehydrogenase 2 levels in group III were significantly lower than those in groups I and II. Aspartate aminotransferase, creatine kinase, and lactate dehydrogenase 1 plus lactate dehydrogenase 2 levels in group II were lower than those in group I, without statistically significant differences. Plasma oxypurinol concentrations were significantly higher in group III than in group II. It was concluded that allopurinol had resultant high myocardial protective effects in dose-related fashion, but its effect might be attributed to oxypurinol levels formed by its degradation.

Effects of cyclosporine and 15-deoxyspergualin on coronary arteriosclerosis after heart transplantation in the rat.

The development of graft coronary arteriosclerosis remains a serious consequence after heart transplantation and may limit long-term survival. The purpose of this study was to evaluate the effects of 15-Deoxyspergualin on graft coronary arteriosclerosis after heterotopic heart transplantation in a rat model and compare the effects to those of cyclosporine treatment. Two groups of Lewis rats (n = 7 each group) underwent heterotopic heart transplantation from Fischer 344 donors and were treated with either cyclosporine (10 mg/kg/day) or 15-Deoxyspergualin (3 mg/kg/day). Histologic evaluations of rejection (scale: 0 = none, 3 = severe) and graft coronary arteriosclerosis (scale: 0 = normal, 4 = occluded) were made 60 days after transplantation. No significant difference was found between the two groups with respect to the degree of rejection (2.0 +/- 0.7 in the cyclosporine-treated group versus 2.0 +/- 0.5 in the 15-Deoxyspergualin-treated group). However, the extent of graft coronary arteriosclerosis in the 15-Deoxyspergualin-treated group was significantly less than that seen in the cyclosporine-treated group (1.11 +/- 0.34 versus 1.71 +/- 0.24, p < 0.01). Furthermore, the incidence of diseased vessels among all observed vessels was significantly lower in the 15-Deoxyspergualin-treated group compared with the cyclosporine-treated group (63% +/- 12% versus 76% +/- 7%, p < 0.05). Although the protective mechanism of 15-Deoxyspergualin is unknown, it most likely possesses a different immunosuppressive mechanism of action from cyclosporine. We concluded that 15-Deoxyspergualin is superior to cyclosporine in preventing graft coronary arteriosclerosis after heart transplantation.

Extracardiac conduit composed of gutter-shaped prosthesis and pedicled pericardial valved patch for pulmonary trunk reconstruction.

A conduit for reconstruction of the pulmonary trunk is presented. A Gelseal vascular prosthesis (Vascutek Ltd, Inchinnan, Scotland) was split longitudinally in two halves, and one half was used as a posterior wall of the conduit like a gutter. The anterior wall was constructed by a pedicled pericardial valved patch. Finally, the proximal anastomosis of the conduit was completed with a gusset cut from the Gelseal prosthesis. This conduit can be applied to patients who require the Rastelli procedure, and growth potential of the pedicled pericardial patch may be expected.

The antiproliferative action of deoxyspergualin is different from that induced by amine oxidase.

The amine oxidase activities contained in calf serum and human serum were detected at levels of 90.8 and less than 0.1 nmol O2/minute/ml serum, respectively, by measuring oxygen consumption coupled with spermidine oxidation. Deoxyspergualin (NKT-01) and spergualin (SGL) containing spermidine in their structure were also oxidized in calf serum at the rate of 3.6 and 11.6 nmol O2/minute/ml serum, respectively. To investigate whether amine oxidase is essential for NKT-01 and SGL to exhibit their antiproliferative activities or not, the in vitro activities of NKT-01, SGL and polyamines against L1210 cells were examined in the presence of calf or human serum. Polyamines exhibited antiproliferative activity only in the presence of calf serum, while NKT-01 and SGL inhibited cell growth in the presence of both calf and human serum. In the presence of calf serum the activity of NKT-01 was inhibited by aminoguanidine, an amine oxidase inhibitor. Aminoguanidine did not inhibit the activity of NKT-01 in the presence of human serum. The activity of NKT-01 was shown at much lower concentrations in the presence of human serum than that in the presence of calf serum, and was strongly dependent on incubation time. The in vivo activities of NKT-01, SGL and SGL derivatives correlated with their in vitro activities in the presence of human serum. These results suggest that the in vivo antitumor activities of NKT-01, SGL and SGL derivatives may be attributed to a mechanism different from those of amine oxidase-oxidized product and represent a novel growth inhibitory action.

Recent advance in treatment of Stanford type A aortic dissection.

During the period between November 1986 and November 1988, 13 consecutive patients with Stanford type A aortic dissection (8 acute and 5 chronic) were treated as follows: (1) urgent operation for cases with pericardial tamponade or severe heart failure, (2) initial medical treatment followed by elective operation for acute but stable cases or chronic cases, and (3) routine use of open distal anastomosis or selective cerebral perfusion. One patient died during medical treatment: 5 patients were operated on emergently. The remaining 2 acute and 5 chronic cases were operated on electively. There were no operative deaths, neurological disturbances, or late deaths. It is suggested that acute dissection of the ascending aorta requires immediate surgical intervention, especially when the entry is in the ascending aorta. On the other hand, it is also suggested that one could avoid emergency operations in selected cases with retrograde extension of the aortic dissection.

Valvuloplasty for aortic valve regurgitation resulting from cusp prolapse.

Three adults, 2 with tricuspid aortic valve and 1 with bicuspid valve, underwent valvuloplasty for aortic valve regurgitation resulting from cusp prolapse. Surgical procedures consisted of combined cusp plication by triangular cusp resection and subcommissural annuloplasty. Doppler echocardiography revealed trivial aortic valve regurgitation intraoperatively and less than I/IV at discharge in all cases. After mean follow-up of 15 months, 2 tricuspid aortic valve patients remain I/IV regurgitation and II/IV in the bicuspid patient. Although long-term results remain unclear, our results show that this procedure is feasible and beneficial in patients with aortic valve regurgitation due to cusp prolapse.

[Surgery for aortic valve disease with congenital bicuspid aortic valve].

From January 1998 to December 2002, a total of 120 patients underwent aortic valve surgery at our institution. Of these, 26 patients (22%) had congenital bicuspid aortic valve (BAV). Main valvular lesion of BAV was aortic valve stenosis (AS) in 17 and regurgitation (AR) in 9. There was no significant difference in the aortic annular size between BAV and non-BAV cases measured by echocardiography preoperatively [22.8 +/- 2.0 mm versus 22.5 +/- 2.2 mm in AS (NS), and 25.4 +/- 2.4 mm versus 23.4 +/- 2.5 mm in AR (NS)]. At operation, however, supraannular type prosthetic valve was selected more frequently in BAV than in non-BAV because of the difficulty of implanting the proper size prosthetic valve in annular position in BAV [10/25 (40%) in BAV versus 18/91 (20%) in non-BAV (p < 0.05)]. Moreover, ascending aortic dimension in BAV cases was significantly larger than in non-BAV cases [43.7 +/- 7.3 mm versus 39.6 +/- 7.3 mm (p<0.05)]. These features were more prominent in non-raphe BAV cases. These results suggested that operative procedure including prosthetic valve selection needs careful consideration in BAV especially no-raphe patients.

[A clinical experience of agranulocytosis just after open heart surgery].

A 63-year-old woman who underwent aortic and mitral valve replacement developed agranulocytosis just after operation. It was considered that agranulocytosis was caused by bone marrow suppression by antiarrhythmic agent and extracorporeal circulation. Her white blood cell counts decreased to 300/mm3 on the third postoperative day, but increased surprisingly 5 days after administration of G-CSF. Fortunately she did not suffered from severe infection, and thereafter postoperative course was uneventful. Although agranulocytosis just after open heart surgery has not been reported, it appears that G-CSF might be useful.

[Epicardial stripping for constrictive pericarditis after mitral valve plasty; report of a case].

A 65-year-old man who underwent mitral valve plasty was readmitted the hospital with severe dyspnea and hypotension 7 months after operation. Results of computerized tomographic scanning and transesophageal echocardiography showed pericardial thickening and left ventricle out flow stenosis due to a constrictive epicardial peel. At the time of reoperation, he underwent both pericardial and epicardial stripping. He demonstrated only limited hemodynamic improvement after pericardial stripping. His hemodynamic status improved markedly after epicardial stripping. His postoperative course was uneventful and no complication was recognized. Epicardial stripping is important in patients with epicardial sclerosis.

[Reoperation for baffle leaks and baffle stenosis following Mustard operation; report of a case].

A 1-year-old baby boy underwent Mustard operation for simple transposition of the great arteries. He began to complain of fatigability with moderate cyanosis and polycytemia at the age of 23. Cardiac catheterization revealed baffle leaks at the superior vena cava (SVC) channel, but baffle stenosis was not diagnosed then. After the patch closure of the baffle leaks, he suffered from hypoxia and high SVC pressure. Baffle stenosis at the entry of the SVC channel into the functional right atrium was diagnosed by re-catheterization. Patch enlargement of the baffle stenosis was successfully performed. We must take it into consideration that baffle leaks following Mustard operation often coexist with baffle stenosis, requiring vigorous pre- and intra-operative exploration.

[A clinical study of the myocardial protective effect of allopurinol].

This study was proposed to study the myocardial protective effect of allopurinol clinically. This study involved 65 patients undergone coronary artery bypass operations or cardiac valve replacements or plasties. Patients were divided into two groups: group I, 30 patients received 2,400 mg of allopurinol preoperatively; group II, 35 patients undergoing no treatment of allopurinol. Postoperative values of GOT, CK-MB and LDH1 + LDH2 in group I were significantly lower than that of group II. These results suggest that allopurinol has advantageous effect on myocardial protection.

[Open heart surgery without homologous blood transfusion in elderly patients].

Preoperative autologous blood donation has been widely accepted to perform surgery in orthopedics, gynecology and cardiac surgery. In elderly patients, however, it has been supposed that most of these patients have anemic tendency before predonation as well as poor response to erythropoietic stimuli, so that preoperative blood deposit is limited to apply them. In order to reduce homologous blood transfusion in open-heart surgery, preoperative blood deposit, combined with erythropoietin administration and intraoperative blood salvage, have been routinely used even for the elderly patients in our hospital since 1989. In present study, we verified above concepts and obtained the results that demonstrated little differences in the blood reproducing ability, the rate of predonation, and the recovery after the operation, between the elderly and the younger. We concluded that autologous blood transfusion combining preoperative deposit with intraoperative blood salvage was the efficient and safe method even in the elderly patients.

[Surgical treatment of tricuspid regurgitation].

The purpose of this study is to compare early and late results of tricuspid valve replacement (TVR), tricuspid annuloplasty (TAP) and non operative management for patients with tricuspid regurgitation (TR). 5 patients underwent TVR and 70 patients received TAP (Kay-Boyd's annuloplasty in 16, Bex reducer method in 40, Carpentier's ring method in 14). 21 patients were managed non-operatively. The following results were obtained. TR should be repaired aggressively, if the regurgitation was more than second degree and tricuspid annulus was above three finger breadth. Judging from the pattern of residual TR after Kay-Boyd's annuloplasty and Bex reducer method, Bex reducer and Carpentier's ring should be placed over the three commissures except the conduction tract.