Horizontal transposition of vertical rectus muscles for treatment of excyclotropia

Background: Horizontal transposition of the vertical rectus muscles has been performed for treatment of excyclotropia associated with congenital absence of the superior oblique, and for residual excyclotropia after the Harada-Ito operation. However, the amount of excyclotropia that can be corrected and whether this technique alters the vertical muscle balance is not well known. We report the surgical results of three patients with pure excyclotropia who underwent unilateral one-half tendon width horizontal transpositions of vertical rectus muscles. Methods: A one half muscle width temporal transposition of the superior rectus and nasal transposition of the inferior rectus muscles of one eye was per formed in three patients with pure excyclotropia and no associated hypertropia. All three had intermittent torsional diplopia before surgery. Results: Postoperatively, excyclotropia decreased significantly in all fields of gaze, with 8° of reduction by synoptophore and 12.3° of reduction by fundus photography on average. There was no associated vertical or horizontal deviation. All three patients reported improvements of cyclofusion. Conclusion: One-half muscle width temporal transposition of the superior rectus and nasal transposition of the inferior rectus muscles was effective in ameliorating excyclotropia and corrected subjective complaints without altering vertical muscle balance.     

Spontaneous rupture of the thoracic aorta

BACKGROUND: Spontaneous rupture of the thoracic aorta without trauma, aneurysm, or dissection is an extremely rare but catastrophic disorder. Two cases of spontaneous aortic rupture are presented, both treated surgically with satisfactory results. METHODS: A review of the English literature found 16 patients with the diagnosis of spontaneous rupture of the thoracic aorta from 1961 through 1998. Eighteen reported cases, including the 2 cases presented herein, are reviewed. RESULTS: The representative clinical picture is one of a middle-aged hypertensive patient with acute chest pain and collapse, with imaging modalities demonstrating hemopericardium, hemomediastinum, or hemothorax. According to the reported experiences, aortography was accurate for identifying the rupture site although the findings were sometimes subtle. Misdiagnosis or nonsurgical management resulted in the patient's death. All 8 patients who did not undergo aortic repair died within 3 weeks after the onset, whereas 9 of 10 patients who underwent surgical aortic repair survived. CONCLUSIONS: For patients with a definitive or possible diagnosis of spontaneous rupture of the thoracic aorta, prompt operation is imperative through an optimal surgical approach to identify and repair the rupture site with appropriate circulatory support.     

Lysosomal accumulation of SCMAS (subunit c of mitochondrial ATP synthase) in neurons of the mouse model of mucopolysaccharidosis III B

The neurodegenerative disease MPS III B (Sanfilippo syndrome type B) is caused by mutations in the gene encoding the lysosomal enzyme alpha-N-acetylglucosaminidase, with a resulting block in heparan sulfate degradation. A mouse model with disruption of the Naglu gene allows detailed study of brain pathology. In contrast to somatic cells, which accumulate primarily heparan sulfate, neurons accumulate a number of apparently unrelated metabolites, including subunit c of mitochondrial ATP synthase (SCMAS). SCMAS accumulated from 1 month of age, primarily in the medial entorhinal cortex and layer V of the somatosensory cortex. Its accumulation was not due to the absence of specific proteases. Light microscopy of brain sections of 6-months-old mice showed SCMAS to accumulate in the same areas as glycosaminoglycan and unesterified cholesterol, in the same cells as ubiquitin and GM3 ganglioside, and in the same organelles as Lamp 1 and Lamp 2. Cryo-immuno electron microscopy showed SCMAS to be present in Lamp positive vesicles bounded by a single membrane (lysosomes), in fingerprint-like layered arrays. GM3 ganglioside was found in the same lysosomes, but was not associated with the SCMAS arrays. GM3 ganglioside was also seen in lysosomes of microglia, suggesting phagocytosis of neuronal membranes. Samples used for cryo-EM and further processed by standard EM procedures (osmium tetroxide fixation and plastic embedding) showed the disappearance of the SCMAS fingerprint arrays and appearance in the same location of "zebra bodies", well known but little understood inclusions in the brain of patients with mucopolysaccharidoses.     

Contribution of active and inactive states of the human 5-HT4d receptor to the functional activities of 5-HT4-receptor agonists

In the present study, binding affinities of 5-hydroxytryptamine-4 (5-HT(4)) ligands for the human 5-HT(4d) receptor were determined using the agonist [(3)H]5-HT and the selective 5-HT(4) antagonist [(3)H]GR113,808. We also compared the affinity differences between [(3)H]5-HT binding (K(H)) and [(3)H]GR113,808 binding (K(L)) with their activities as 5-HT(4) ligands. Binding studies using [(3)H]5-HT revealed that the human 5-HT(4d) receptor has two binding sites, whereas [(3)H]GR113,808 yielded a single binding site. Additionally, the number of [(3)H]5-HT binding sites decreased in the presence of guanosine-5'-O-(3-thiotriphosphate) (GTPgammaS), but the number of [(3)H]GR113,808 sites did not change. In competitive binding assays, full agonists such as 5-methoxytryptamine and tegaserod showed 2- to 8-fold higher affinities for [(3)H]5-HT binding (K(H)) than for [(3)H]GR113,808 binding (K(L)) (K(H)K(L)). Finally, partial agonists displayed similar binding affinities for both radioligands (K(H) = K(L)). These findings suggest that the equilibrium between active and inactive states of the human 5-HT(4d) receptor relies on the functional activities of 5-HT(4) ligands, and these states affect the affinities of 5-HT(4) ligands in the competitive binding assay.     

Acceleration of actin polymerization and rapid microfilament reorganization in cultured hepatocytes by cyclochlorotin, a hepatotoxic cyclic peptide.

Cyclochlorotin (= chloropeptide, CC) is a hepatotoxic mycotoxin of Penicillium islandicum Sopp. The effect of CC on actin polymerization was examined by the measurement of changes in fluorescence intensity using pyrene-labeled actin and high shear viscosity. In the presence of CC, the time course of actin polymerization was accelerated in a dose dependent manner (2.5 ng/ml-2.5 microg/ml), without affecting the final level of viscosity. CC exerted a strong stabilizing effect on actin, enabling it to maintain its filamentous form in the presence of members of actin-binding proteins, including those of the gelsolin family prepared from hepatocytes. Microscopic observation revealed that in cultured hepatocytes, 1.0 microg/ml of CC induced bleb formation and changes in the microfilament. These observations indicated that after contact of the hepatocyte with CC, the following events were probable. The toxin passed through the cell membrane by a transport system and immediately reacted with the actin-actin binding proteins underlying the lipid bilayer. Bleb formation and hepatotoxicity were thus induced.     

Pulmonary thromboembolism during the Niigata Chuetsu earthquake in 2004]

We encountered 2 cases of pulmonary thromboembolism developed during refuge for Niigata Chuetsu earthquake in 2004. Case 1 was a 76-year-old woman who moved to the back seat of a car for refuge since the earthquake struck on October 23rd, 2004. When she emerged from the car on the morning of October 25th, she felt sudden dyspnea and lost consciousness. On arrival at the hospital, she had low blood pressure and hypoxemia, hypocapnia, and metabolic acidosis. Based on her clinical history and her symptoms, pulmonary thromboembolism was suspected and heparinization was begun immediately. In our hospital, the chest CT angiography proved the diagnosis. She was transferred to a university hospital for further treatment. Case 2 was a 79-year-old woman. She spent only one night in a car. Fifteen days after the earthquake, chest tightness and dyspnea occurred. Although her symptoms were improved and disappeared, she came to our hospital. Chest CT images confirmed pulmonary thromboembolism, and treatment with heparin was begun. We think this pulmonary thromboembolism was related to the knee-bending position she had assumed in the car and decreased activity during refuge. This is a clinical condition which could happen during disasters in the future. We should recognize the likelihood of pulmonary thromboembolisms in the disasters in the future.     

Ganglioneuroblastoma arising within a retroperitoneal mature cystic teratoma

We discuss an extremely rare case of ganglioneuroblastoma arising within a retroperitoneal mature cystic teratoma. Radiological examinations showed a cystic tumor sandwiched between the pancreas and left kidney. Surgery was scheduled because the tumor seemed to have originated from the pancreas. En-block resection of the tumor with distal pancreatectomy, splenectomy, and left adrenalectomy was performed. In terms of macroscopic appearance, the tumor mainly consisted of a unilocular cystic mass, but the presence of a smaller, solid mass was also noted within the tumor. Histopathologic examination confirmed that the cystic mass was consistent with a mature cystic teratoma of the retroperitoneum, and in addition, a ganglioneuroblastoma was evident in the solid component. Histopathologically, the ganglioneuroblastomatous area was intimately associated with dermoid tissue of the mature cystic teratoma, thus this case was diagnosed to be a mature cystic teratoma with malignant transformation. To best of our knowledge, this is the first reported case of ganglioneuroblastoma arising in a mature cystic teratoma.