Desmin and vimentin are intermediate filaments that play crucial roles in maturation, maintenance and recovery of muscle fibers and mesenchymal cells. The expression of these proteins has not been investigated extensively in human fetuses. In the present study, we examined the immunohistochemical expression of intermediate filaments in skeletal muscles of the head, neck and thorax in 12 mid-term human fetuses at 9-18 weeks of gestation. We also used immunohistochemistry to localise expression of the myosin heavy chain, and silver-impregnation to identify the fetal endomysium.Expression of desmin and vimentin was already detectable in intercostal muscle at 9weeks, especially at sites of muscle attachment to the perichondrium. At this stage, myosin heavy chain was expressed throughout the muscle fibers, and the endomysium had already developed. Beginning with punctate expression, the positive areas became diffusely distributed in the muscle fibers. At 15-18 weeks, intermediate filament proteinswere extensively expressed in all of the muscles examined. Expression at the bone-muscle interface was continuous with expression along the intramuscular tendon fibres. These results suggest that the development of intermediate filaments begins in areas of mechanical stress due to early muscle contraction. Their initially punctate distribution, as observed here, probably corresponds to the earliest stage of fetal enthesis formation.

The lateral pterygoid muscle has unique anatomical, physiological and functional properties. Since it is attached to the temporomandibular joint (TMJ) disc, its pathologies are closely related to TMJ disorders, which affect many people worldwide. Muscle structures and units are characterized by their morphological appearance, nerve distribution and function. In the present study, we examined the intramuscular innervation pattern of the lateral pterygoid muscle using modified sihler's method. Two types of innervation pattern were evident. In type I, representing the majority of the samples, a total of three branches arising from the main trunk of the mandibular nerve and the buccal nerve innervated the inferior head of the muscle, while branches from the buccal nerve innervated the superior head. In type II, divisions of the lateral pterygoid nerve branched from the buccal nerve located between the heads of the lateral pterygoid muscle and innervated each head separately. Interestingly, muscle bundles with a stronger tendineous structure showed much more innervation than other parts of the muscle. Future studies including quantitative analysis of the nerve distribution to the muscle bundles are warranted.

To examine morphological differences in Morton's interdigital neuroma between two elderly human populations, we conducted comparative study using 40 Japanese (27 males, 13 females; mean age, 81.2 years) and 21 Finnish (6 males, 15 females; mean age, 80.5 years) cadavers. We defined the neuroma as a thickening of the nerve of at least two-fold relative to the non-pathological proximal part. The incidence of this neuroma was 25% (10/40) in the Japanese and 33.3% (7/21) in the Finnish cadavers. Moderate or severe hallux valgus (with an angle of more than 20 degrees) was seen in half of the 40 Japanese cadavers (7 males, 13 females), but was absent in the Finnish cadavers. Such hallux valgus was present in 7 (5 males, 2 females) of the 10 Japanese cadavers with neuroma. Moreover, in 2 Japanese cadavers, a paper-like, specialized type of neuroma was associated with the deformity. Pathogenesis of Morton's neuroma might be different between human populations with or without hallux valgus.

Summary:We examined the topohistology of the subscapularis tendon at the glenohumeral joint in 10 mid-term (15-16 weeks of gestation) and 10 late-stage (27-32 weeks) human fetuses. At both stages, there were two patterns of terminal course of the subscapularis tendon: 1) the tendon was tightly attached to the medial part of the joint capsule and extended anterosuperiorly along the capsule to the lesser tubercle (7/10 mid-term fetuses; 5/10 late-stage fetuses); 2) the tendon passed superiorly through the joint cavity for a long distance in combination with the subcoracoid bursa opening widely to the joint cavity (3/10 mid-term fetuses; 5/10 late-stage fetuses). The lower glenoid labrum tended to be well developed in the former pattern because the subscapularis tendon did not interfere with the superior extension of the labrum. With only one exception (late stage), the capsule-attaching tendon was seen in fetuses in which the coracoid process was located on the superior side of the lesser tubercle, whereas the intra-articular tendon accompanied the coracoid process at the same supero-inferior level of the tubercle. Thus, the topographical relationship between the coracoid process and lesser tubercle in fetuses seemed to determine the courses of the subscapularis tendon at the glenohumeral joint. The present variation in the subscapularis tendon was likely connected with the adult morphologies of the middle and inferior glenohumeral ligaments or folds, whose variations are well known.

Summary: Fetal hip joint is characterized by its highly flexion and lateral rotation although adult anatomy of the femoral nerve and iliofemoral ligament suggested the medial rotation. To investigate topographical anatomy of the femoral nerve, artery and vein in the femoral triangle, we histologically examined 11 fetuses (15-37 weeks). The nerve-vessel topographical relation was basically similar to that in adults, but the fan-like nerve division was seen in the horizontal plane in the smaller specimens in contrast to that included in the sagittal plane in the larger specimens. The medial or internal rotation of the nerve division seemed to occur in late stage fetuses, at birth and at infancy. Blood supply to the head of the femur might be also accelerated by changes in the hip joint position.

Summary: Carbonic anhydrases (CAs) plays a critical functional role in the ciliary body and retina for maintenance of microenvironment. With immunohistochemistry using orbital contents from 8 human fetuses (12-16 weeks of gestation), we examined expressions of CAs isozymes-1, 2, 3, 6, 7 9 and 12 and found strong reactivity of CA9 in extra-ocular fibrous tissues in the anterior and posterior eyes. CA9 is known to express in the fetal joint cartilage to maintain pH against hypoxia: actually, in the present specimens, the SO pulley and its tendon was strongly positive for CA9. The CA9-positive anterior fibrous tissues were positive for smooth muscle actin and connected the orbital aspect of the 4 rectus muscle with the palpebral conjunctiva, whereas the posterior tissue was negative for smooth muscle actin and corresponded to the lateral insertion tendon of the orbitalis muscle. The anterior CA9-positve tissues seemed to correspond to the primitive form of the sleeve and pulley system. Any of matrix substances (collagen types I and II, aggrecan, versican, fibronectin, tenascin and hyaluronan) displayed a distribution pattern specific for the CA9-positive fibrous tissues. Therefore, whether or not CA9 was positive in the fibrous tissue seemed not to depend on the tissue components such as the extracellular matrix and intermediate filaments but to suggest a stressful condition such as hypoxia, unsuitable base balance and/or under mechanical stress.

The Mitsubishi Group and Japanese PWR utilities have been engaged in a continual process of main control board design improvement. Advanced main control boards with fully digital instrumentation and touch operation technology have been adopted in newly constructed plants. Moreover, instrumentation and control systems have been fully digitalized and applied not only to non-safety systems but to safety systems as well. Such a system in general is referred to as a fully digital system. From this time forward, the application of this fully digital system will become mainstream with the modernization of existing plants. Yet, unlike newly constructed plants, restrictions unique to existing plants will need to be taken into consideration. In the construction of Ikata Units 1 and 2 of Shikoku electric power co., measures such as those described below were implemented so as to achieve standardization with future construction in mind: (1) A thorough interface check was conducted to ensure compatibility with sections outside the scope of modernization. Additionally, to minimize the affect modernization had on the operating system, the system was verified by operators and verification results were reflected in the board layout, system specifications, and the like. (2) Due to limited space for board installation, a plan was devised for housing a processor and determining the remote input/output board location. (3) Onsite tests was minimized in order to complete construction within a short period of time, i.e., within the regularly scheduled inspection period, and the degree of completion of the product was enhanced prior to shipment by a full combination test conducted at the plant. In addition, the local construction period was shortened by devising a plan for installing the board and conducting interface tests during the previous regularly scheduled inspection and the current regularly scheduled inspection.