[Beneficial effects of 3,4-diaminopyridine in a 26-year-old woman with DOK7 congenital myasthenic syndrome who was originally diagnosed with facioscapulohumeral dystrophy]

We report a 26-year-old woman who had respiratory dysfunction and muscle weakness at birth and was diagnosed with facioscapulohumeral dystrophy at the age of 5. The extent of muscle weakness fluctuated daily or weekly and deteriorated in menstrual periods. At the age of 12, she noted improvements in symptoms when taking procaterol hydrochloride and began to take it regularly. After that, her condition stabilized. At the age of 26, she visited our hospital presenting with ptosis, muscle weakness in the face, trunk, and proximal limbs, and easy fatigability. Serum CK was normal; anti-acetylcholine receptor and anti-muscle specific tyrosine kinase antibodies were negative. A repetitive stimulation test in the trapezius muscle showed a waning phenomenon. Gene analysis for congenital myasthenic syndrome (CMS) revealed a new mutation in the DOK7 gene; the diagnosis of CMS was confirmed. Her symptoms worsened with ambenonium chloride but improved with 3,4-diaminopyridine. Our findings suggest that daily or weekly fluctuation and worsening with a menses in muscle weakness is an important diagnostic feature of CMS.

LRP4 third β-propeller domain mutations cause novel congenital myasthenia by compromising agrin-mediated MuSK signaling in a position-specific manner

Congenital myasthenic syndromes (CMS) are heterogeneous disorders in which the safety margin of neuromuscular transmission is compromised by one or more specific mechanisms. Using Sanger and exome sequencing in a CMS patient, we identified two heteroallelic mutations, p.Glu1233Lys and p.Arg1277His, in LRP4 coding for the postsynaptic low-density lipoprotein receptor-related protein 4. LRP4, expressed on the surface of the postsynaptic membrane of the neuromuscular junction, is a receptor for neurally secreted agrin, and LRP4 bound by agrin activates MuSK. Activated MuSK in concert with Dok-7 stimulates rapsyn to concentrate and anchor AChR on the postsynaptic membrane and interacts with other proteins implicated in the assembly and maintenance of the neuromuscular junction. LRP4 also functions as an inhibitor of Wnt/beta-catenin signaling. The identified mutations in LRP4 are located at the edge of its 3rd beta-propeller domain and decrease binding affinity of LRP4 for both MuSK and agrin. Mutations in the LRP4 3rd beta-propeller domain were previously reported to impair Wnt signaling and cause bone diseases including Cenani-Lenz syndactyly syndrome and sclerosteosis-2. By analyzing naturally occurring and artificially introduced mutations in the LRP4 3rd beta-propeller domain, we show that the edge of the domain regulates the MuSK signaling whereas its central cavity governs Wnt signaling. We conclude that LRP4 is a new CMS disease gene and that the 3rd beta propeller domain of LRP4 mediates the two signaling pathways in a position-specific manner.

Mutations in the C-terminal domain of ColQ in endplate acetylcholinesterase deficiency compromise ColQ-MuSK interaction

Acetylcholinesterase (AChE) at the neuromuscular junction (NMJ) is mostly composed of an asymmetric form in which three tetramers of catalytic AChE subunits are linked to a triple helical collagen Q (ColQ). Mutations in COLQ cause endplate AChE deficiency. We report three patients with endplate AChE deficiency with five recessive COLQ mutations. Sedimentation profiles showed that p.Val322Asp and p.Arg227X, but not p.Cys444Tyr, p.Asp447His, or p.Arg452Cys, inhibit formation of triple helical ColQ. In vitro overlay of mutant ColQ-tailed AChE on muscle sections of Colq(-/-) mice revealed that p.Cys444Tyr, p.Asp447His, and p.Arg452Cys in the C-terminal domain (CTD) abrogate anchoring ColQ-tailed AChE to the NMJ. In vitro plate-binding assay similarly demonstrated that the three mutants inhibit binding of ColQ-tailed AChE to MuSK. We also confirmed the pathogenicity of p.Asp447His by treating Colq(-/-) mice with adeno-associated virus serotype 8 carrying mutant COLQ-p.Asp447His. The treated mice showed no improvement in motor functions and no anchoring of ColQ-tailed AChE at the NMJ. Electroporation of mutant COLQ harboring p.Cys444Tyr, p.Asp447His, and p.Arg452Cys into anterior tibial muscles of Colq(-/-) mice similarly failed to anchor ColQ-tailed AChE at the NMJ. We proved that the missense mutations in ColQ-CTD cause endplate AChE deficiency by compromising ColQ-MuSK interaction at the NMJ.

Switching to an L/N-type calcium channel blocker shows renoprotective effects in patients with chronic kidney disease: the Kyoto Cilnidipine Study

OBJECTIVE

This open-label, randomized controlled trial investigated the effects of cilnidipine, an L/N-type calcium channel blocker (CCB), in patients with chronic kidney disease (CKD).

METHODS

Sixty patients with CKD and well-controlled hypertension being treated with a renin- angiotensin system (RAS) inhibitor and an L-type CCB (L-CCB) were randomly assigned either to switch from the L-CCB to cilnidipine after a 4-week observation period or to continue with L-CCB treatment. Blood pressure, heart rate and renal function were monitored for 12 months. Data were available for analysis from 50 patients: 24 from the cilnidipine group and 26 from the L-CCB group.

RESULTS

Blood pressure was well controlled in both groups. After 12 months, proteinuria and heart rate were significantly decreased in the cilnidipine group, but proteinuria increased and heart rate remained unchanged in the L-CCB group. There was a significant positive correlation between the percentage changes in proteinuria and heart rate.

CONCLUSIONS

Cilnidipine has antihypertensive effects equivalent to those of L-CCBs. In patients with CKD, proteinuria can be decreased by switching from an L-CCB to cilnidipine, thereby improving renal function.

[Clinical features of congenital myasthenic syndrome in Japan]

OBJECTIVE

We examined the clinical and neurophysiological features of Japanese patients with congenital myasthenic syndrome (CMS).

METHOD

Subjects were five patients who were diagnosed with CMS on the basis of clinical course, repetitive nerve stimulation (RNS), and genetic analysis.

RESULTS

Four patients manifested motor retardation within one year of birth, while one manifested motor intolerance at three years of age. The most characteristic symptom observed in all the patients was fluctuating muscle weakness, which varied on a daily basis or continued for several days after the late infancy period. Only one patient manifested daily fluctuation of muscle weakness. RNS of the accessory nerve evoked a decrementing response in three patients who were examined;however, RNS of the median, ulnar, and tibial nerves (one patient each) did not evoke such responses. After the edrophonium chloride test, no improvement was seen even if the patients manifested ptosis. For judgment of this test, improvement in decrementing rate observed while performing RNS was useful. All five patients who were administered medication based on the results of genetic analysis demonstrated an improvement in their symptoms.

CONCLUSION

We suggest that CMS can be diagnosed based on careful examination and electrophysiological results. CMS is a treatable disorder, and therefore, correct diagnosis is important.

A novel mutation in SCN4A causes severe myotonia and school-age-onset paralytic episodes

Mutations in the pore-forming subunit of the skeletal muscle sodium channel (SCN4A) are responsible for hyperkalemic periodic paralysis, paramyotonia congenita and sodium channel myotonia. These disorders are classified based on their cardinal symptoms, myotonia and/or paralysis. We report the case of a Japanese boy with a novel mutation of SCN4A, p.I693L, who exhibited severe episodic myotonia from infancy and later onset mild paralytic attack. He started to have apneic episodes with generalized hypertonia at age of 11 months, then developed severe episodic myotonia since 2 years of age. He presented characteristic generalized features which resembled Schwarz-Jampel syndrome. After 7 years old, paralytic episodes occurred several times a year. The compound muscle action potential did not change during short and long exercise tests. Functional analysis of the mutant channel expressed in cultured cell revealed enhancement of the activation and disruption of the slow inactivation, which were consistent with myotonia and paralytic attack. The severe clinical features in his infancy may correspond to myotonia permanence, however, he subsequently experienced paralytic attacks. This case provides an example of the complexity and overlap of the clinical features of sodium channel myotonic disorders.

Aerodynamics of a bio-inspired flexible flapping-wing micro air vehicle

MAVs (micro air vehicles) with a maximal dimension of 15 cm and nominal flight speeds of around 10 m s⁻¹, operate in a Reynolds number regime of 10⁵ or lower, in which most natural flyers including insects, bats and birds fly. Furthermore, due to their light weight and low flight speed, the MAVs' flight characteristics are substantially affected by environmental factors such as wind gust. Like natural flyers, the wing structures of MAVs are often flexible and tend to deform during flight. Consequently, the aero/fluid and structural dynamics of these flyers are closely linked to each other, making the entire flight vehicle difficult to analyze. We have recently developed a hummingbird-inspired, flapping flexible wing MAV with a weight of 2.4-3.0 g and a wingspan of 10-12 cm. In this study, we carry out an integrated study of the flexible wing aerodynamics of this flapping MAV by combining an in-house computational fluid dynamic (CFD) method and wind tunnel experiments. A CFD model that has a realistic wing planform and can mimic realistic flexible wing kinematics is established, which provides a quantitative prediction of unsteady aerodynamics of the four-winged MAV in terms of vortex and wake structures and their relationship with aerodynamic force generation. Wind tunnel experiments further confirm the effectiveness of the clap and fling mechanism employed in this bio-inspired MAV as well as the importance of the wing flexibility in designing small flapping-wing MAVs.

Disease recurrence patterns after R0 resection of hilar cholangiocarcinoma

BACKGROUND

There is little information regarding the clinical behaviour of hilar cholangiocarcinoma after curative resection.

METHODS

A retrospective study was undertaken of 79 consecutive patients with hilar cholangiocarcinoma who had undergone major hepatectomy (three or more Couinaud segments) concomitant with caudate lobectomy, and had negative resection margins. Sites of initial disease recurrence were classified as locoregional (porta hepatis) or distant (intrahepatic, peritoneal, para-aortic lymph nodal or extra-abdominal). Univariable and multivariable analyses were performed to determine the factors potentially related to recurrence.

RESULTS

Disease recurrence was observed in 42 (53 per cent) of the 79 patients. Cumulative recurrence rates at 3 and 4 years after surgery were 52 and 56 per cent respectively. Locoregional recurrence alone was observed in eight (10 per cent) and distant metastasis in 34 (43 per cent) of the 79 patients after R0 resection. Positive nodal involvement and high International Union Against Cancer tumour (T) stage were independent prognostic factors associated with distant metastasis.

CONCLUSION

Distant metastases are more common than locoregional recurrence after R0 resection for hilar cholangiocarcinoma, and associated with nodal involvement and high T stage.

Expression Levels of Enzymes Related to In Situ Estrogen Synthesis and Clinicopathological Parameters in Breast Cancer Patients

Background: Local estrogen synthesis may play an important role of progression of breast cancer with hormone receptors. Local progression of breast cancer may depend on high concentration of estrogens and estrogen receptor status. To clarify correlation between expression levels of enzymes in breast cancer and clinicopathological parameters, we analyzed expression of steroid sulfatase(STS), estrogen sulfatase(EST), 17b-hydroxyl steroid dehydrogenase type I & II(17b-HSDI & II) and aromatase. In addition, mRNA expression of estrogens receptor alpha(ERa), estrogen receptor beta(ERb), cycline D1 and erbB2 were measured. Material and Methods: The mRNA expression levels of genes in 196 breast cancer tissues removed from surgery were assayed by RT-PCR. Results: The level of STS were significantly higher in patients with clinical stage. STS expressed none in stage 0 or I, 0.011 in stage II, and 0.013 amol/1 amol b-actin in stage 3 or 4. In addition, EST expressed 58.5 amol/1 amol b-actin in stage 2 and 36.8 in stage 3 or 4, otherwise, the expression level of EST in stage 0 or 1 revealed 15.3 amol/1 amol b-actin. There were no correlation between clinical stage and aromatase expression. Expression levels of ERa and cyclineD1 significantly correlated with protein levels of ER, and there were significant correlation between erbB2 expression and prognosis of patients. Conclusion: Up-regulation of STS play an important role in tumor progression of breast cancer.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 4155.

Callosal lesions and delirious behavior during febrile illness

We retrospectively reviewed electroencephalography and magnetic resonance imaging findings for 21 children exhibiting delirious behavior during febrile illness. Among these, five patients had transient callosal lesions with or without white matter lesions on diffusion-weighted images. We compared the clinical characteristics, duration, and components of delirious behavior, the duration and severity of reduced consciousness, and EEG findings among patients with or without callosal lesions. No significant differences were detected in these items according to the presence or absence of callosal lesions. Adding insight into the pathogenesis of this condition, our study revealed that callosal lesions are not uncommon in patients exhibiting delirious behavior during febrile illness.

[Bronchial schwannoma diagnosis by surgical treatment; report of a case]

18-year-old male was referred to our hospital due to persistent cough. The patient was admitted for the investigation of the abnormal shadow on a chest X-ray and chest computed tomography (CT). Chest CT showed a 2.5 cm nodular shadow in the right lower lobe. Bronchofiberscopy revealed the polypoid lesion at the right lower lobe bronchus obstructing the entire lumen of B8-10. The tumor surface was smooth and rich in small vessels. Right lower lobectomy was peformed. The diagnosis of schwannoma was confirmd with the S-100 positive immunohistochemical stain. Bronchial schwannoma is relatively rare disease; less than 90 cases have been reported with respect to schwannoma of case report in Japan.

[Aortic valve replacement for the patient with Osler-Rendu-Weber disease]

Osler Rendu-Weber (O-R W) disease (hereditary haemorrhagic telangiectasia) is characterized by an anormality of the peripheral blood vessels which often causes recurrent epistaxis. We presented a case of aortic valve replacement for the patient with O-R-W disease. A 75-year-old woman diagnosed as O-R-W disease with chest pain and dyspnea was admitted. Preoperative transthoratic echocardiography showed severe aortic valve stenosis (AS) with a pressure gradient (from left ventricle to ascending aorta) of 72.5 mmHg. Urgent aortic valve replacement (AVR) was performed after preoperative hormonal (estrogen-progesterone) therapy, that might be effective for bleeding from vascular ectasia. No hemorrhagic tendency was recognized and the postoperative course was uneventful.

[Surgical treatment for the patient with atrial septal defect and Andersen syndrome]

An 18-year-old girl with atrial septal defect and Andersen syndrome is reported. Andersen syndrome was described as a hereditary disease characterized by periodic paralysis, prolongation of the QT interval with ventricular arrhythmia and characteristic physical features including low set ear and micrognathia. We successfully performed cardiac operation for this rare associated malformation.

[Norwood procedure after colostomy; report of a case]

We encountered a baby who was diagnosed with anal atresia, interruption of aortic arch (type B), aortic stenosis, mitral stenosis, single atrium, large ventricular septal defects, aberrant origin right subclavian artery. We operated on him using the Norwood procedure after a colostomy. Aortic arch was reconstructed by interposing with an 8 mm graft and the right ventricular-pulmonary artery (RV-PA) conduit was chosen for pulmonary flow. We closed the sternum 6 days after the Norwood procedure. We extubated him 16 days after delayed sternal closure. There was no trouble with his stoma and no sign of infection. The postoperative echocardiography didn't show the finding which left pulmonary artery was stenotic, but the lung perfusion schintigraphy revealed an imbalance in the distribution of lung perfusion. He was discharged 70 days after undergoing the Norwood procedure.

[Successful repair of supravalvular aortic stenosis using Steinberg 3 sinuses reconstruction; report of a case]

Steinberg method is a modification of Doty extended aortoplasty for supravalvular aortic stenosis (SAS). This modification entails placement of an additional patch in the left coronary sinus. A 3-year-old boy was diagnosed as SAS with aortic valvular stenosis. He was noticed a systolic murmur from 1 month after his birth. Echocardiography showed left ventricular hypertrophy, and pressure gradient of 80 mmHg was measured between the ascending aorta and the left ventricle. Cardiac catheterization revealed severe aortic stenosis at the sino-tubular (ST) junction. We adopted Steinberg 3 sinuses reconstruction. After this operation, there was no pressure gradient at ST junction although aortic valvular stenosis remained and mild aortic valve regurgitation newly developed. As this method can produce a symmetric aortic root, it may reduce aortic valve deformity especially on the left coronary cusp.

[Surgical treatment for postinfarction ventricular septal perforation]

Between November 1985 and April 2003, surgical treatment for ventricular septal perforation (VSP) after acute myocardial infarction was performed in 16 patients. Patients were divided into 2 groups by method of operation. One group is infarct exclusion technique (n = 10). The other group is trans right ventricular (RV) approach (n = 6). No significant differences were observed between 2 groups in preoperative states. Operative death rate was high in both groups. Five patients (50%) were died in infarct exclusion group, 4 patients (67%) in trans RV group. Infarct exclusion technique needed longer extracorporeal circulation time (201 +/- 33 min) than trans RV approach (170 +/- 32 min). Although trans RV approach is attractive for its simplicity, 3 cases died of rupture of remained left ventricle infarction area. On the other hand, there were no mortality cases caused by left ventricle rupture in infarct exclusion technique group. As this result, we select infarct exclusion technique as a surgical correction for VSP.