Imaging of a vortex lattice transition in YNi2B2C by scanning tunneling spectroscopy

The vortex lattices in YNi2B2C under the magnetic fields H up to 3 T applied along both the a and the c axes have been studied by scanning tunneling spectroscopy at 4.2 K. The vortex lattice transition has been found to occur in different manners for H parallela and H parallelc; in H parallela a slightly distorted hexagonal vortex lattice has been found to transform to a nearly square one above 1.0 T with increasing H, while in H parallelc the transition occurs at a much lower field around 0.1 T. The unconventional steep increase of the quasiparticle density of states outside the vortex core has also been found well below H(c2).

[Stenosis of Carpentier-Edwards pericardial bioprosthesis in the tricuspid position caused by adhesion of native valve cusps to the bioprosthesis].

We experienced a case of dysfunction of Carpentier-Edwards pericardial bioprosthesis in the tricuspid position. Explanted bioprosthesis showed overgrowth of neointima from ring to cusps and adhesion to remnants of native cusps. This restricted the motion of the pericardial leaflets resulting in orifice stenosis. Care must be taken in such valve replacement by this prosthesis leaving native valve tissue.

[A report of two cases of Carpentier-Edwards pericardial mitral valve malfunction due to neointimal overgrowth expanding to valve cusps].

Two cases of Carpentier-Edwards pericardial mitral valve malfunction due to neointimal overgrowth were reported. Case one was a 51-year-old female undergone redo mitral valve replacement at nine years after first operation. Removed valve showed remarkable overgrowth of neointima expanding to the valve cusps. Case two was a 67-year-old male. A valve removed at nine years after first operation and at 1.5 years after recovery of prosthetic valve endocarditis. Removed valve also showed neointimal overgrowth expanding to the valve cusps. Although we experienced only two cases of neointimal overgrowth, these findings were considered being important in durability of Carpentier-Edwards pericardial valve.

[Reoperation for malfunction of Ionescu-Shiley bovine pericardial bioprosthetic valves in the mitral position--special consideration with emergency operation].

Sixty-eight patients have had mitral valve replacement with Ionescu-Shiley bovine pericardial bioprosthesis from 1981 to 1984. Thirty five patients were required reoperation due to primary tissue failure of the bioprosthesis, 10 (28.6%) were on emergency basis and 25 (71.4%) were on elective. Hospital deaths were two (20.0%) on emergency and four (16.0%) on elective. Clinical features of emergency cases were as follows: progressive congestive heart failure in eight, severe hemolysis with massive hemoglobinuria in eight and acute renal failure in four. Cusp tears were observed in all valves, 8.1 +/- 1.5 mm in emergency group and 4.2 +/- 3.6 mm in elective group. Neointimal ingrowth over Dacron cloth of the inner surface of the stent was absent in 29 valves (89.2%). Calcification was observed in seven valves, however these were not dominant causes of primary tissue failure. Clinical symptoms were correlated with structural deterioration of explanted valves. Structural deterioration of the bioprosthesis may occur suddenly and progressively. Our experience demonstrated that life-threatening prosthetic valve failure may occur with a relatively high incidence and that careful follow-up is needed for Ionescu-Shiley bovine pericardial bioprosthesis.

[A case report of chronic dissecting aortic aneurysm (Stanford type A) with circumferential detachment of the intima].

A 57-year-old man underwent Bentall's procedure (Piehler's modification) and partial aortic arch replacement for Stanford type A chronic aortic dissection. Circumferential detachment of intima with intimal intussusception into the aortic arch was found at the time of operation. Preoperative findings did not show the intimal tear involving entire circumference of the ascending aorta. He was asymptomatic but coughing before consulting our hospital. He was discharged from the hospital 26 days after operation.

[A case report of a successful surgery for thoracoabdominal aortic aneurysm under partial cardiopulmonary bypass with selective perfusion of major abdominal branches].

A 69-year-old man showed gradually developing thoracoabdominal aortic aneurysm (TAAA) after coronary artery bypass grafting. The patient underwent graft replacement of TAAA uneventfully under partial cardiopulmonary bypass with selective perfusion of major abdominal branches. The major abdominal branches and two pairs of intercostal arteries were reconstructed. The patient showed no organ failure or spinal damage postoperatively. Partial cardiopulmonary bypass with selective perfusion of abdominal branches successfully protected both the visceral organs and the spinal cord from ischemia in a TAAA surgery.

[Report of a case with re-mitral valve replacement for Björk-Shiley Delrin disc valve prosthesis--disc wear of the Delrin disc 20 years after implantation].

We reported a patient in whom slight congestive heart failure gradually developed 20 years after mitral valve replacement with a Delrin disc Björk-Shiley valve prosthesis. Although no evident cause of prosthetic valve malfunction could be detected preoperatively, the mitral prosthesis was excised and replaced uneventfully with a 29 mm St. Jude Medical valve prosthesis. At gross inspection, marked wears of the Delrin disc surface and strut shaped indentations were present. These disc variance, occurred much earlier than initially predicted by Dr. Björk, allowed prosthetic valve malfunction. The patient with this specific model should be carefully followed-up, if necessary, performed reoperation.

[Two cases of left atrial myxoma originating from mitral annulus].

We experienced two cases of left atrial myxoma originating from mitral annulus. Mitral valve replacement and mitral valvulo-annuloplasty were performed in each case, because of the presence of mitral leaflet defect due to removal of the myxoma. Two dimensional echocardiography was a useful method to confirm the location and decide the surgical approach.

[Repeat open heart surgery in a case associated with persistent left superior vena cava: a method of simple occlusion of L-SVC using an alternative extra-pericardial approach and retrograde cardioplegia].

Twelve years ago, we reported a method of extrapericardial approach to the L-SVC. Since then we have used this approach and performed simple occlusion of L-SVC during cardiopulmonary bypass without any cerebral complications. We have been expecting for a long time and have believed that this method will be very valuable especially in repeat open heart surgery. A case of 49-year-old man successfully underwent a redo operation for mitral and tricuspid valve replacement using extrapericardial occlusion of the L-SVC and retrograde cardioplegia. Although there was a pitfall for retrograde cardioplegia in the persistent L-SVC and a possibility of steal of cardioplegic fluid through a branch of the accessory hemiazygos vein during retrograde cardioplegia for a case with persistent L-SVC, sufficient cardiac protection was obtained in the case presented.

[Mitral valve replacement through a right thoracotomy, with intact coronary artery bypass grafts].

A 68-year-old male who had previously undergone aorto-coronary artery bypass grafting was admitted for mitral valve surgery. Because of the presence of anteriorly placed intact coronary artery bypass grafts, we used right thoracotomy to replace the mitral valve. Cardiopulmonary bypass was established after cannulation of the femoral artery and bicaval cannulation, and continuous retorograde cardioplegia with cold blood was infused. Residual air was evacuated through left ventricular vent catheter and aortic air vent hole. Post operative course was uneventful.

[Mitral and aortic valve replacement associated with aortitis syndrome: a case report].

A case of aortic and mitral regurgitation associated with aortitis syndrome was presented. The patient was a 36-year-old female who admitted for palpitation and dyspnea. Left ventriculography showed moderate MR. Aortography showed moderate AR and multiple occlusive lesion of the aortic arch branches. After the inflammation was controlled, aortic and mitral valve replacement was performed. Postoperative course was uneventful. Histologically, aortic and mitral valve showed capillary increase and infiltration of inflammatory cells, mainly lymphocytes.

[Early omental transposition for postoperative sterno-mediastinitis].

We report 3 successful cases of postoperative sterno-mediastinitis treated with single-stage procedure. 2 of them were infected with MRSA (Methicillin resistant staphylococcus aureus), and the other was with klebsiella pneumoniae. Neither open drainage nor irrigation were performed previously, but only administrations of sensitive antibiotics. Intensive debridement, irrigation and omental transposition were performed at one time, between 6 and 15 days from the diagnosis. It could achieve decrease of hospitalization. We recommend early single-stage procedure with omental transposition for postoperative sterno-mediastinitis before extension and aggravation of the infection.

[Subdural hematoma complicated after open heart surgery: a report of two cases with successful treatment].

Two cases of subdural hematoma complicated after open heart surgery were successfully treated during thirty years history of the department. A 45 year-old woman underwent tricuspid valve replacement due to isolated congenital tricuspid insufficiency. On the 27th postoperative day, she was suddenly attacked by headache, and disturbance of consciousness was recognized with gradual deterioration. Brain CT scan showed a subdural hematoma on the right frontal region. Immediate irrigation of the hematoma was performed. Postoperative course was uneventful, and she was discharged without any complications. A 59 year-old woman underwent mitral valve replacement due to mitral re-stenosis. On the 3rd postoperative day, disturbance of consciousness was seen suddenly. Brain CT scan showed a subdural hematoma in the bilateral posterior cranial fossa. Immediate GL-YCEOL drip infusion was started. On the next day consciousness returned without operation and she was discharged without any neurological complications. Both patients did not have head trauma during pre and post operative period. It was important to consider the possibility of a intracranial hematoma, when the disturbance of consciousness was recognized after open heart surgery and/or during anticoagulant therapy.

[A case report of aortic valve stenosis combined with complete A-V block during chronic hemodialysis].

A 52-year-old man treated by hemodialysis under the diagnosis of chronic renal failure admitted to our hospital due to aortic valve stenosis and complete A-V block. Aortic valve was severely calcified, and the cause of complete A-V block was considered caused by the progressive calcification invasing to conduction system. The aortic valve replacement and pacemaker implantation using myocardial lead were simultaneously. Postoperative course was uneventful. The efficacy of simultaneous operation of aortic valve and pacemaker implantation was emphasized. However the generator implantation was recommended to perform in the several days after the operation because of destruction of the pacemaker function by counter shock for arrhythmia in the early post operative period.

Menotropin stimulation after prolonged gonadotropin releasing hormone agonist pretreatment for in vitro fertilization in patients with endometriosis.

Two protocols were scheduled for in vitro fertilization and embryo transfer (IVF-ET) in patients with various stages of endometriosis who were resistant to conventional therapies. In the ultralong protocol (21 patients), gonadotropin releasing hormone agonist (Gn-RHa) was administered for at least 60 days prior to ovarian stimulation along with menotropin until human chorionic gonadotropin was injected. In the long protocol (11 patients), Gn-RHa was started at the midluteal phase and exogenous gonadotropin was commenced between the third and the seventh day of the menstrual cycle after pituitary suppression. The estradiol response and the number of retrieved oocytes, fertilized oocytes, cleaved oocytes, and transferred embryos were similar in both groups but the clinical pregnancy rate per transfer was superior in the ultralong protocol (67 vs 27%). The miscarriage rate was 14% (2/14) in the ultralong protocol. Prolonged Gn-RHa suppression of ovarian function before superovulation may overcome some causes of infertility in patients with endometriosis.

[Clinical features of hypernatremic hyperosmolar delirium following open heart surgery].

Five cases of hypernatremic hyperosmolar delirium after open heart surgery were reviewed. Minimum serum osmolarity at the time of developing delirium in these cases was 336 mOsm/l. Blood glucose level did not reached to the levels of the typical criteria of hyperosmolar hyperglycemic nonketotic diabetic coma in all cases. The authors have shown that it was difficult to recognize this unique disorder in early postoperative stage. Because of its non-specific symptoms and the postoperative courses which required the patients' cares with much more dry side in water balance. In order to treat the patients with hypernatremic hyperosmolar delirium, the correction of serum osmolarity should be done very slowly, because water intoxication should be prevented. In all five cases in this paper were recovered from delirium as the time when serum natrium level and serum osmolarity were restored to the normal state. We concluded that in order to get a good prognosis of this characteristic disorder, we have shown early recognition of serum hypernatremia and hyperosmolarity state and consequently adequate treatment mentioned above are primarily important.

Beta-actinin is equivalent to Cap Z protein.

Chicken skeletal muscle beta-actinin, previously reported to bind the slow-exchanging (pointed) ends of actin filaments was purified to homogeneity. By two dimensional gel electrophoresis, it consists of two subunits, beta I (35 kDa) and beta II (32 kDa), and each subunit has two isoforms. The amino acid sequences of V8 protease-digested peptides of beta I were nearly identical with those of portions of the muscle barbed end-blocking protein Cap Z alpha, although several amino acids were different from those deduced from cDNA sequences (Casella, J.F., Casella, S.J., Hollands, J.A., Caldwell, J.E., and Cooper, J.A. (1989) Proc. Natl. Acad. Sci. U.S.A. 86, 5800-5804). The amino acid sequences of two peptides from beta II were completely identical with portions of Cap Z beta deduced from cDNA sequences (Caldwell, J.E., Waddle, J.A., Cooper, J.A., Hollands, J.A., Casella, S.J., and Casella, J.F. (1989) J. Biol. Chem. 264, 12648-12652). beta-Actinin capped the barbed end of an actin filament as evidenced by actin assembly of myosin S1-decorated filaments and specifically its impairment of growth in the "barbed" direction. Thus it is concluded that highly purified beta-actinin is identical with the more recently described Cap Z, an actin barbed-end capping protein of chicken skeletal muscle.

[A case of congenital absence of the right coronary aortic cusp].

A 12-year-old boy with absence of the right coronary cusp underwent aortic valve replacement with a 21 mm St. Jude Medical prosthetic valve. He was known to have noncyanotic congenital heart disease at the age of 2 months. The diagnosis of aortic insufficiency was first made when he was 1 1/4 years old. Intensive medical treatment was continued while he was growing up. Cardiac catheterization was performed repeatedly at ages 3 1/2 and 7. The findings on the fourth cardiac catheterization at 12 years of age were pulmonary arterial pressure of 90/60 mmHg, left ventricular end-diastolic pressure of 25 mmHg and poor contraction of the left ventricle. Although IABP support was necessary for treatment of severe low cardiac output state in the early postoperative period, he was discharged at 1 month after operation, Now, he goes to school under anticoagulant therapy. Intensive medical care followed by elective aortic valve replacement may be a useful treatment for isolated congenital absence of the aortic valve cusp.

[Surgical experience with an infant with discrete subaortic stenosis successfully treated by aortoventriculoplasty].

A 3-year-old female with discrete subaortic stenosis is presented. Angiocardiographic studies showed a long segmental narrowing below the aortic valve. Although membranectomy and myectomy were selected as a surgical treatment, a longitudinal aortotomy was performed in order to extend the operation to ventriculoseptoplasty. During the operation, the right coronary cusp was seriously damaged and therefore aortoventriculoplasty was applied. The aortic valve was replaced with a 21 mm St. Jude Medical mechanical prosthesis. The left ventricular outflow tract was adequately enlarged, and postoperative course was uneventful.

[Vascular ring associated with severe ventricular septal defect--report of a case with simultaneously surgical treatment].

An 1 year and 4 months ill infant with vascular ring and VSD is presented. She had serious pulmonary hypertension and dysphagia because of vascular ring consisting of right aortic arch with left ligamentum arteriosum. Division of the ligamentum arteriosum and simultaneous patch closure of large VSD were performed successfully. Postoperative course was uneventful and she recovered from her body weight favorably.