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Neural stem and precursor cells persist postnatally throughout adulthood and are capable of responding to numerous endogenous and exogenous signals by modifying their proliferation and differentiation. Whereas adult neurogenesis has been extensively studied in the dentate gyrus of the hippocampal formation and in the subventricular zone adjacent to the wall of the lateral ventricles, we and others have recently reported constitutive adult neurogenesis in other brain structures, including the hypothalamus. In this study, we used immunohistochemistry to study the expression of the neuroblast marker doublecortin (DCX), and compared its expression pattern in adult ovine, mouse, and human hypothalamic tissues. Our results indicate that DCX-positive cells resembling immature and developing neurons occur in a wide range of hypothalamic nuclei in all three species, although with different distribution patterns. In addition, the morphology of DCX-positive cells varied depending on their location. DCX-positive cells near the third ventricle had the morphology of very immature neuroblasts, a round shape with no processes, whereas those located deeper in the parenchyma such as in the ventromedial nucleus were fusiform and showed a bipolar morphology. Extending this observation, we showed that among the cohort of immature neurons entering the ventromedial nucleus, some appeared to undergo maturation, as revealed by the partial colocalization of DCX with markers of more mature neurons, e.g., human neuronal protein C and D (HuC/D). This study provides further confirmation of the existence of an adult hypothalamic neurogenic niche and argues for the potential existence of a migratory path within the hypothalamus.

Until now there has been no definitive anatomical study describing the area where the parotid duct enters the buccinator muscle. In this study, we performed anatomical and histological examinations to investigate the relationship between the parotid duct and the buccinator muscle. Thirty specimens (including the buccinator and the terminal portion of the parotid duct) were obtained from embalmed Korean cadavers. Dissection was performed on 22 of these specimens, and the remaining eight specimens were prepared for histological examination and stained with haematoxylin–eosin or Gomori trichrome. In all specimens, small, distinct muscle fibres originating from the buccinator muscle extended to and inserted into the terminal portion of the parotid duct. The topography of these fibres varied, and we classified them into three categories according to where they originated. Type I buccinator muscle fibres, which inserted into the terminal portion of the parotid duct, originated simultaneously from the anterior and posterior aspects of the duct (ten cases, 45.5%). Type II fibres originated from the anterior aspect of the duct and inserted into the anterior side of the duct (seven cases, 31.8%). Type III fibres originated from the posterior aspect of the parotid duct and ran anteriorly toward the duct (five cases, 22.7%). These results were confirmed in the histological examination of all eight specimens. Based on these findings, we have proposed a tentative description of the physiological role of the buccinator muscle fibres in salivary secretion and in the formation of the sialoliths.

Objective. The purpose of this study was to determine the ability of high-frequency ultrasonography to provide for direct evaluation of the annular and cruciform finger pulley system. Methods. In the first part of the work, a cadaveric study was performed to outline the normal anatomy of the annular and cruciform finger pulley system. Eighteen cadaveric hands were cut (n = 10) or dissected (n = 8). Two musculoskeletal radiologists retrospectively reviewed in consensus the photographs of anatomic sections and dissections. This cadaveric study gave the 2 readers the opportunity to learn the normal anatomy of the finger pulley system. In the second part of the work, the annular and cruciform finger pulley system of 20 hands of volunteers was evaluated by ultrasonography with a 17-MHz linear transducer. Images were retrospectively analyzed by means of consensus of the 2 radiologists with respect to the visibility of each finger pulley. Results. For annular (A) pulleys, high-frequency ultrasonography showed A1, A2, A3, and A4 in 100%, 100%, 65%, and 100% of cases, respectively. For cruciform (C) pulleys, high-frequency ultrasonography showed only C1 in 45% of cases. Direct visualization of A5, C2, and C3 was not possible. Conclusions. High-frequency ultrasonography allows excellent depiction of finger pulleys except for annular pulley A5 and cruciform pulleys C2 and

With continued archaeological discoveries of skeletal remains in the USA and Europe, discussion of the possible aetiology for recognized cases of symmetrical erosive polyarthropathy include the spondylarthropathies and rheumatoid arthritis. One skeleton from the fourth century site of Lisieux and a second from the eleventh century site of Rouen are characterized by numerous symmetrical marginal erosions, primarily involving the metacarpophalangeal and proximal interphalangeal joints. Results of maroscopic, microscopic and radiological examination are highly suggestive of a modern-day diagnosis of rheumatoid arthritis. These data are consistent with the presence of rheumatoid arthritis before the onset of the fourteenth century. © 1997 John Wiley & Sons, Ltd.