A case of transient bioprosthetic valve regurgitation and hemolysis devoloping early after surgery using Carpentier-Edwards valve.

The Carpentier-Edwards pericardial bioprosthesis has been markedly improved in the long-term results and valve-related complications including valve dysfunction, compared to the previous generation bioprosthesis. We report a patient in whom transient prosthetic valve regurgitation and hemolysis occurred early after mitral valve replacement using a Carpentier-Edwards pericardial bioprosthesis and were resolved by preservative therapy. The patient was a 77-year-old female diagnosed with severe mitral valve stenosis and insufficiency. She underwent mitral valve replacement with a Carpentier-Edwards pericardial bioprosthesis. Opening and closing of the three leaflets looked good on intraoperative transesophageal echocardiography (TEE). The only prosthetic valve regurgitation was evident at the central region where the leaflets form coaptation, and no abnormal findings were seen. Serum lactate dehydrogenase (LDH) was decreased to 405 U/l after surgery. However, LDH again began to increase on the 3rd day after surgery and it increased to 1,830 U/l on the 14th day after surgery. Hemolytic urine was detected on 10th day after surgery. PVL was not detected, but moderate abnormal regurgitation from the outside of the stent pocket was detected on TEE. Revision of valve replacement was considered, but LDH thereafter to 393 U/l on 41st day after surgery. The TEE was repeated, and only a trace of central jet was detected without abnormal regurgitation, unlike the previous examination. The patient did not develop any complications thereafter and was discharged on 47th day after surgery. LDH was nearly normal at the time of discharge.     

The biological characteristics and chemosensitivity of anaplastic thyroid carcinoma transplanted into nude mice

Three xenografts established from three patients with anaplastic thyroid carcinoma were investigated for their biological characteristics and chemosensitivity. The histological and immunohistochemical findings of these tumors were almost the same as those of the original tumors. Although the growth rate of each xenograft was constant, the tumor doubling time varied from 4.8 per 9.0 days, and the labeling indexes, determined using bromodeoxyuridine pulse labeling, varied from 11.4 to 25.1 per cent. The chemosensitivity tests were performed according to the Battelle Columbus Laboratories Protocol, with adriamycin, cyclophosphamide, cisplatin, mitomycin C and tegafur administered intraperitoneally to tumor-bearing nude mice in maximum tolerable doses. Tumors with slower growth rates tended to be sensitive to more drugs. Furthermore, cyclophosphamide showed antitumor effects against all the tumors tested. Although previous treatments of the original tumors may have affected the results, our results suggest that a more suitable chemotherapy for anaplastic thyroid carcinoma could be developed.     

A case of hypertrophic pachymeningitis, resolved by antimicrobial therapy]

A 65-year-old woman with diabetes mellitus and chronic otitis media developed headache, fever, and hoarseness, all of which did not responded to the oral antibiotics. As stiff neck and lower cranial nerve palsies appeared, bacterial meningitis was suspected. Neurological examination revealed the right hearing disturbance, right recurrent laryngeal nerve palsy, left sternocleidomastoid muscle atrophy and bilateral tongue atrophy. The CSF examination revealed mild pleocytosis and elevated protein, but no bacterial organism was cultured from the CSF. CT scans showed bilateral mastoiditis, and the right mastoid process and a posterior part of the petrous bone were eroded, indicating the exposed bony structures to the posterior fossa. MRI scans demonstrated the thickening of the dura mater of the posterior fossa and the right cerebellar tentorium. This is a rare example of bacterial pachymeningitis of the posterior fossa, the clinical symptoms and MRI findings of which resolved solely by antimicrobial agents without corticosteroid.     

Antegrade selective cerebral perfusion combined with deep hypothermic circulatory arrest on cerebral circulation: comparison between pulsatile and nonpulsatile blood flows.

PURPOSE: In aortic arch surgeries, antegrade selective cerebral perfusion (SCP) combined with deep hypothermic circulatory arrest (DHCA) has been recently widely used in institutions as one of the most reliable methods for cerebral protection. However, some studies reported a 3.7-9.3% incidence of postoperative cerebral complications. To perform antegrade SCP more safely, we sought to examine the impact of pulsatile flow perfusion during DHCA on cerebral tissue metabolism, focusing on physiological effects of pulsatile flow perfusion. MATERIALS AND METHODS: Sixteen pigs were divided into 2 groups. In each group, antegrade SCP combined with DHCA was conducted. During circulatory arrest, for SCP, a pulsatile flow (group P) and a nonpulsatile flow (group N) were used. We compared results between group P and group N. Jugular venous oxygen saturation (SjO(2)) and cerebral tissue oxygen partial pressure (PtO(2)) were measured at baseline, and continuously throughout the extracorporeal circulation. Hematocrit (Ht), and concentrations of S-100 protein and CK-BB in blood and the cerebrospinal fluid (CSF) were measured at baseline (before the beginning of extracorporeal circulation), following SCP, and after rewarming. Following rewarming, each brain under perfused fixation was removed, and histopathological examinations were conducted using Kluver-Barrera and Tunnel staining methods, electron micrograph. RESULTS: SjO(2) was found to be within normal ranges until after SCP, but decreased with rewarming in both groups. In Group N, changes in SjO(2) were significant, with a decrease to < or =50%. In Group N, concentrations of S-100 protein and CK-BB in CSF after SCP and after rewarming were significantly higher than those in Group P. The time needed for rewarming to 36 degrees C in Group P was shorter than that in Group N. CONCLUSION: Our results suggest that the pulsatile flow circulation method shows cerebral protection effects with increasing blood flow in small cerebral tissues. In addition, it is effective for improving the imbalance between oxygen supply and demand, especially in the process of rewarming from hypothermic conditions. This method seems to be useful as an adjunct in hypothermic circulatory arrest procedures.     

Efficacy of continuous cleansing with teicoplanin on post-CABG methicillin-resistant staphylococcus aureus (MRSA) mediastinitis: report of a case.

The patient was a 48-year-old male who was diagnosed with unstable angina. He had worsening cardiogenic shock during coronary angiography. Emergency coronary artery bypass grafting (CABG) was performed. He had a methicillin-resistant Staphylococcus aureus (MRSA) mediastinitis on day 22 after CABG. Drains were placed in the anterior mediastinum, left thoracic cavity, and abscess cavity, and another drain was placed in the mediastinal space for continuous cleansing with povidone iodine, oxydol. For antibiotics, teicoplanin (TEIC) was administered intravenously and to the local site via the cleansing drain for about one month. No MRSA was detected by culture in discharges from the mediastinal drain. Inflammatory findings were improved, and the patient was discharged and resumed everyday life without recurrence of inflammation as of eight months. Although the number of cases of MRSA mediastinitis is small and accumulation of cases is necessary to investigate therapeutic methods and selection of antibiotics, our department will select closed continuous cleansing and TEIC for antibiotics as the first choice for MRSA mediastinitis, and accumulate cases to investigate its efficacy.     

Enhancement of norepinephrine-induced transient contraction in aortic smooth muscle of diabetic mice

Changes in norepinephrine-induced transient contractions in Ca2+-deficient solution were investigated in the aortic smooth muscles of diabetic ALS (alloxan-induced diabetes susceptible) mice. The transient contractions in diabetic mice were significantly larger than those in normal mice. The longer incubation of the muscle preparations in Ca2+-deficient solution made the transient contractions smaller, probably due to the leakage and decrease in norepinephrine-releasable stored Ca2+. The rate of this reduction in contraction was slower in diabetic mice. These results suggest that the leakage of intracellular stored Ca2+ caused by extracellular Ca2+ deficiency is attenuated in diabetic mice, contributing to enhanced norepinephrine-induced transient contractions.     

Repair of a ruptured aortic arch aneurysm complicated by postoperative paraplegia: Report of a case

We report herein the rare case of a 79-year-old man who suffered permanent paraplegia after undergoing an otherwise successful total arch replacement for a ruptured aortic arch aneurysm. During cardiopulmonary bypass, perfusion to the distal aorta was maintained from the femoral artery, and postoperative aortography showed intact tributaries from the aorta including the intercostal arteries. Postoperative paraplegia is an extremely rare complication of operations on the aortic arch; however, we speculate that the paraplegia in this patient could be attributed either to a steal phenomenon involving the radicular artery, or to the anatomical particularity of the spinal cord artery described by Cole and Gutelius as the segmental system.     

Localization of calcitonin receptor mRNA in the mouse brain: coexistence with serotonin transporter mRNA

To elucidate the sites of and mechanisms of analgesic effect of centrally injected calcitonin, we examined expression of calcitonin receptor mRNA in the mouse brain by in situ hybridization techniques. Calcitonin receptor mRNA was expressed in various brain regions, including the preoptic area, dorsomedial hypothalamic nucleus, lateral hypothalamic area, periaqueductal gray, dorsal raphe nucleus, locus coeruleus, lateral parabrachial nucleus, gigantocellular reticular nucleus alpha part, lateral paragigantocellular nucleus, raphe magnus nucleus and solitary tract nucleus, which are known to play important roles in pain modulation. In addition, a double in situ hybridization technique demonstrated the intense expression of calcitonin receptor mRNA on serotonergic neurons in some raphe nuclei and the lateral paragigantocellular nucleus, suggesting the involvement of central serotonergic pathways in analgesic effect of calcitonin.     

Inactivation of mitogen‐activated protein kinase is neither necessary nor sufficient for the onset of pronuclear formation in mouse oocytes

Mammalian oocytes are arrested at metaphase II due to high MAP kinase activity. After fertilization, oocytes resume meiosis, leading to female chromosome segregation, polar body emission and pronuclear (PN) formation. Previous biochemical studies showed that MAP kinase activity remained high for several hours after fertilization and began to decrease in parallel with PN formation. It has been thought that MAP kinase activity is incompatible with PN formation, and its inactivation is required for the initiation of PN formation in mammalian oocytes. In this study, we revisited this hypothesis by examining MAP kinase activity and PN formation in individual mouse oocytes using cytological analysis. We showed that MAP kinase activity in oocytes could be evaluated using phospho‐ERK1/2 immunofluorescent staining. Co‐immunofluorescent staining of phospho‐ERK1/2 and nuclear pore components showed that PN formation preceded MAP kinase inactivation and could be initiated while MAP kinase activity was still high. Moreover, artificial inactivation of MAP kinase or its downstream target, ribosomal S6 kinase, accelerated but did not rapidly induce PN formation. Our results show that although the MAP kinase pathway negatively regulates PN formation, its inactivation is neither necessary nor sufficient for PN formation. These results suggest the involvement of other essential factor(s) in this process.