Numerical Simulation on Sand Accumulation behind Artificial Reefs and Enhancement of Windblown Sand to Hinterland

Salients were formed in the lee of two artificial reefs (submerged breakwaters) constructed on Kimigahama Beach in Chiba Prefecture, Japan, owing to the wave-sheltering effect of the reefs, and then, a significant amount of fine sand was transported inland from the salients by wind action. In this study, not only shoreline changes after the installation of the two artificial reefs but also beach changes caused by windblown sand were predicted using a model, in which the BG model (a model for predicting three-dimensional beach changes due to waves based on Bagnold’s concept) is combined with a cellular automaton method. Reproduction calculation was carried out on the basis of field data. Beach changes after the artificial reefs were removed were also predicted and the effect of beach nourishment was investigated. It was concluded that landward sand transport by wind is accelerated when wave-sheltering structures such as an artificial reef are constructed on a coast composed of fine sand, and such an effect can be successfully predicted by using the present model

中国の経済発展と農村問題

In December 1978, the Economic Reform and Open-door Policy was introduced in China, one of the rapidly developing socialist countries. The aim of this policy was to expand production capacity under existing production mechanisms. With the introduction of the concept of `the primary stage of socialism\u27 and various types of company ownership, the shift to a market economy has advanced over time. China has attained high economic growth during this time and foreign trade volume has become the third largest in the world. Direct investment by foreign companies has played a signifi cant role in this growth. However, the income gaps between coastal areas (where foreign companies have accumulated) and inland areas and between urban areas and rural areas have grown and continue to do so at a high rate. This has led to improved essential services, such as education, medical treatment, and pension provision, which have hitherto been lacking in farm villages, and has created a situation where more than 200 million `farm laborers\u27 work away from home. The government should consider taking steps to tackle the so-called `three problems\u27 facing agriculture, villages, and farmers, with three potential solutions: increasing farmers\u27 incomes, improving living environment in rural areas, and improving farming technology

Experimental model of chronic pancreatitis, a review - Does it really exist?

Experimental model of pancreatitis is mandatory for elucidating the pathobiology of the disease and also to see the response of a novel treatment. In addition, the need for an animal model of chronic pancreatitis is further strengthened by the relative inaccessibility and paucity of the human pancreatitis tissue. Whereas various models of acute pancreatitis and also of exocrine pancreatic tumor have been described, chronic pancr-eatitis has not been consistently reproduced in experimental animals. Many researchers attempted to establish an experimental model of chronic pancreatitis either by partially obstructing the drainage of pancreatic secretion in dogs and cats or by feeding alcohol to dogs and rats with and without temporary occlusion of the biliopancreatic duct or by surgically inducing ischaemia in the pancreas of the dogs. But, none of these models is identical with human disease. A consistently reproducible model of human chronic pancr-eatitis probably does not exist. In this expanding era of molecular biology which promises us to enhance greatly our understanding of this disease, a right experimental model of chronic pancreatitis is still in progress.疾患の実験モデルの作成は,その疾患の病因,病態の解明,さらに治療法の開発のために重要である｡筆者らの一人は厚生省難治性膵疾患調査研究班の班員として,慢性膵炎の病態の解明や治療法の開発に関する研究を行っており,その研究の一環として,慢性膵炎の実験モデルの作成を現在行っている｡そこで,これまで報告されている慢性膵炎の実験モデルについて概要を報告した｡種々の動物や方法でヒト慢性膵炎に病因,病態,組織像が類似するモデルの作成が試みられてきたが,そのすべてが合致するような慢性膵炎モデルは確 立されてはいない｡近年の分子生物学的研究の進歩は著しく,実験モデルへの応用が種々なされている現在,より簡便で再現性のある慢性膵炎モデルの作成が望まれるところである

α1-Syntrophin–deficient skeletal muscle exhibits hypertrophy and aberrant formation of neuromuscular junctions during regeneration

α1-Syntrophin is a member of the family of dystrophin-associated proteins; it has been shown to recruit neuronal nitric oxide synthase and the water channel aquaporin-4 to the sarcolemma by its PSD-95/SAP-90, Discs-large, ZO-1 homologous domain. To examine the role of α1-syntrophin in muscle regeneration, we injected cardiotoxin into the tibialis anterior muscles of α1-syntrophin–null (α1syn−/−) mice. After the treatment, α1syn−/− muscles displayed remarkable hypertrophy and extensive fiber splitting compared with wild-type regenerating muscles, although the untreated muscles of the mutant mice showed no gross histological change. In the hypertrophied muscles of the mutant mice, the level of insulin-like growth factor-1 transcripts was highly elevated. Interestingly, in an early stage of the regeneration process, α1syn−/− mice showed remarkably deranged neuromuscular junctions (NMJs), accompanied by impaired ability to exercise. The contractile forces were reduced in α1syn−/− regenerating muscles. Our results suggest that the lack of α1-syntrophin might be responsible in part for the muscle hypertrophy, abnormal synapse formation at NMJs, and reduced force generation during regeneration of dystrophin-deficient muscle, all of which are typically observed in the early stages of Duchenne muscular dystrophy patients

Mycotic Posterior Inferior Cerebellar Artery Aneurysm Following Meningitis after Endoscopic Endonasal Transsphenoidal Surgery : Case Report and Review of the Literature

Mycotic intracranial aneurysms (MIAs) are rare infection-mediated arterial wall destructions that result in focal vessel weakness and dilatation. They commonly involve the anterior cerebral circulation, usually following hematogenous embolization from infective cardiac vegetation, and are associated with an elevated risk of rupture. MIAs arising from a posterior inferior cerebellar artery (PICA) are uncommon, and those resulting from contiguous infections are extremely rare. Here, we present a case report and review the literature on rare MIAs involving the distal PICA segment following meningitis after endoscopic endonasal transsphenoidal surgery. A 75-year-old man presented with a 2-year history of progressive visual impairment of the left eye, for which initial cranial magnetic resonance imaging suggested optic perineuritis ; however, conservative management with high-dose steroid therapy did not improve the patient’s condition. He subsequently had biopsy, which confirmed an optic nerve sheath meningioma, for which optic nerve decompression via the endoscopic endonasal approach (EEA) and follow-up radiation therapy was done. He developed postoperative meningitis and subsequently had rupture of left PICA mycotic aneurysm (angiography done a month earlier demonstrated normal left PICA). Risk factors for meningitis were invasive cranial intervention, prolonged steroid use, and radiation therapy. Coil embolization was successfully performed ; however, the patient succumbed to irreversible herniation and infection. MIAs arising from the PICA following meningitis are rare, but complications following surgical intervention and rupture are associated with high morbidity and mortality. A high index of suspicion and early intervention before rupture may prevent poor outcomes.Article信州医学雑誌 71(6) : 415-422, (2023)journal articl

The novel heart-specific RING finger protein 207 is involved in energy metabolism in cardiomyocytes

A failing heart shows severe energy insufficiency, and it is presumed that this energy shortage plays a critical role in the development of cardiac dysfunction. However, little is known about the mechanisms that cause energy metabolic alterations in the failing heart. Here, we show that the novel RING-finger protein 207 (RNF207), which is specifically expressed in the heart, plays a role in cardiac energy metabolism. Depletion of RNF207 in neonatal rat cardiomyocytes (NRCs) leads to a reduced cellular concentration of adenosine triphosphate (ATP) and mitochondrial dysfunction. Consistent with this result, we observed here that the expression of RNF207 was significantly reduced in mice with common cardiac diseases including heart failure. Intriguingly, proteomic approaches revealed that RNF207 interacts with the voltage-dependent anion channel (VDAC), which is considered to be a key regulator of mitochondria function, as an RNF207-interacting protein. Our findings indicate that RNF207 is involved in ATP production by cardiomyocytes, suggesting that RNF207 plays an important role in the development of heart failure

A case of multiple pancreatic cysts with K-ras point mutation in pure pancreatic juice

膵癌の早期診断を行うために,最近の進歩の著しい遺伝子診断を用いて,膵液中のK-ras遺伝子の点突然変異の検討がなされている｡われわれは膵液の細胞診は陰性であるが,K-ras遺伝子の点突然変異を認め,膵全体に多発する膵嚢胞の1例を経験した｡本例は悪性であるとの確診が得られないことや切除するとなれば膵全摘となることなどのために,経過観察を行っているが,18カ月後の現在,嚢胞の増大など認めていない｡膵癌の遺伝子診断の文献的考察を含め,報告する｡Pancreatic cancer is the one of the leading causes of death among cancer deaths and the early diagnosis is one of the main topics of pancreatic research. Mutation of K-ras oncogene at codon 12 has been reported in pancreatic adenoma, hyperplasia of the pancreatic duct, and also in pancreatic cancer, Recently, detection of K-ras point mutation in pure pancreatic juice is underinvestigation as a potential tool of early diagnosis of pancreatic cancer by setting a certain cut-off value. We recently experienced a case of multiple pancreatic cysts without any malignant cells in pancreatic juice, but with a positve point mutation of K-ras oncogene. Operation was deferred after obtaining informed consent from the family, because the lesions were so multiple and extensive as to require total pancreatectomy. Eighteen months follow-up studies did not reveal any deterioration in imaging tests as well as clinical picture