Myosin heavy chain composition of tongue muscle in microphthalmic (mi/mi) mice before and after weaning.

To elucidate the effects of teeth on muscle fibers in the tongue during the developmental process, we examined the expression of muscle contractile proteins and the genes for those proteins in normal mice and microphthalmic (mi/mi) mice with impaired tooth eruption. The mice were observed during the growth period, including weaning, which is when feeding movements undergo major changes. Expression of the myosin heavy chain (MyHC)-2a protein, whose contraction speed is relatively slow, disappeared after weaning in normal mice, while it remained in high concentrations even after weaning in mi/mi mice. The presence of MyHC-2a after weaning in mice with no tooth eruption was attributed to a compensation for lack of proper masticatory function and sucking-like movements, as MyHC-2a is necessary for these movements.     

Auditory brainstem responses after out-of-hospital cardiac arrest: Are they useful for outcome prediction?

We evaluated whether we could predict the neurologic outcome in 55 out-of-hospital cardiac arrest patients using auditory brainstem responses (ABR). ABR patterns were classified into one of 3 types by evaluation of 5 components: type 1, with all 5 components; type 2, lack of at least one response between the 2nd and 5th components; type 3, with only the first component or no response. The relation between the ABR patterns on the 3rd day following resuscitation and the neurologic outcome on hospital discharge was evaluated. The specificity that the 5 awake patients had type-1 ABR was 38%. The sensitivity that the 10 brain dead patients had type-3 ABR was 60%. In the type-1 ABR patients, the negative predictive value that the patients were awake was 100%. In the type-3 ABR patients, the negative predictive value that the patients became brain dead was 90.9%. These results suggest that ABR on the 3rd post-resuscitation day may not be useful for predicting if patients are awake or become brain dead, although the loss of components may be a sign of morbidity, and the presence of the 2nd or later components indicates possible future prevention of brain death.     

Living donor liver transplantation for biliary atresia complicated by situs inversus: technical highlights.

Living-donor liver transplantation (LDLT) has become an established technique to treat children with end-stage liver disease. Biliary atresia (BA), one of the most common indications for liver transplantation in children, can be associated with situs inversus (SI). In the past, the presence of SI has been considered to be an absolute contraindication for liver transplantation because of the technical difficulties. Recently, some reports of successful diseased-donor liver transplantation in patients with BA complicated by SI have been published; however, few reports of that with LDLT exist. The technical difficulties involved with LDLT for such cases have not been described. Herein, we present 4 successful cases of LDLT for BA with SI. Complex anomalies associated with SI, such as a hepatic artery arising from the supraceliac aorta, a preduodenal portal vein, and absence of the retrohepatic inferior vena cava, increase the technical difficulties involved with the operation. Additional caution is required in LDLT because a living-donor graft has short vessels and the availability of vascular grafts from the donor is limited. In conclusion, LDLT for BA complicated by SI can be managed successfully with technical modifications and scrupulous attention. This series represents the largest reported group of patients with BA complicated by SI who underwent a successful LDLT procedure.     

Recurrent mediastinal liposarcoma twenty years after the initial operation: case report

We report a case of mediastinal liposarcoma, recurrent after 20 years. A 58-year-old man who presented with dyspnea on exertion was found to have a large mediastinal tumor in chest computed tomography (CT), and he was referred to our hospital. He had undergone an extirpation of a mediastinal liposarcoma about 20 years earlier, and we suspected its recurrence. Because the tumor was very large, it was removed in two stages. Histologically it was diagnosed as a recurrence of the previous well-differentiated liposarcoma. Although liposarcoma is one of the most common soft-tissue sarcomas in adults, a mediastinal liposarcoma is rare. Because the recurrence rate is very high, it is necessary to follow up carefully over a long term.     

Ectopic cystic thymoma associated with Raynaud's phenomenon.

Mediastinal cystic tumors are well-marginated round lesions that comprise 12% to 18% of all mediastinal masses. These lesions include a variety of diseases with overlapping radiologic appearances and variable prognoses. Pathological examinations are almost always required for differential diagnosis. We encountered a case of anterior mediastinal tumor discovered in the process of investigation of Raynaud's phenomenon. Taking into account the tumor location, a pericardial cyst was initially suspected. However, the tumor was surgically resected and histopathological examinations demonstrated thymus-like tissue in the cyst walls. Raynaud's phenomenon greatly improved after surgery. These findings suggested that cystic thymoma originated from ectopic thymic tissue and is accompanied by paraneoplastic syndrome.     

Spatially and Temporally Regulated Modification of the Receptor-like Protein Tvrosine Phosphatase ζ/β isoforms with Keratan Sulphate in the Developing Chick Brain

Protein tyrosine phosphatase ζ (PTPζRPTPβ) is a proteoglycan-type receptor-like protein tyrosine phosphatase specifically expressed in the brain. In addition to the transmembrane form (PTPζ-A), the extracellular splice variant (PTPζ-S) occurs as a major soluble chondroitin sulphate proteoglycan in the brain. We prepared antibodies which specifically recognize PTPζ-A and -S, and analysed the carbohydrate structures on the two PTPζ isoforms in the developing chick brain. lmmunoprecipitation experiments using these antibodies revealed that almost all of the keratan sulphate recognized by a monoclonal antibody (5D4) was exclusively bound to PTPζ-A and PTPζ-S. Addition of keratan sulphate to these proteoglycans markedly increased from embryonic day (E) 11, in contrast to the addition of Le^X and HNK-1 carbohydrates, which gradually increased during development in accordance with expression of the core proteins, suggesting that keratan sulphate modification plays some specific roles. Moreover, at the early embryonic stage keratan sulphate was observed only in several restricted regions, especially at boundary regions such as the roof plate of the tectum, the zona limitans intrathalamica in the diencephalon, and the mesencephalon-metencephalon boundary. At the mesencephalon-metencephalon boundary, keratan sulphate modification of PTPζ isoforms was specifically observed from E3 to E6 on a ring of cells encircling the neural tube and their radially oriented processes, which were identified as radial glial fibres. This expression pattern of keratan sulphate spatiotemporally corresponded well to the formation of the fovea isthmi, a groove separating the mesencephalon from the metencephalon. These results suggest that carbohydrates including keratan sulphate on PTPζ isoforms play important roles in brain development by modulating the cell-cell and/or cell-substrate interactions mediated by these molecules.