摘要:

AbstractThe fine structure and subepithelial capillaries of the main excretory duct epithelium (MEDE) of the submandibular gland in the Japanese monkey,Macaca fuscatawere investigated by light, scanning, and transmission electron microscopy. Capillaries found beneath the MEDE were all fenestrated ones. Some of them had elevated endothelium known as pored domes. The capillary density (number of capillaries per 200 μm length of MEDE) was 6.05 ± 1.36, and the number of fenestrae per 10 μm length of available endothelium was 11.62 ± 3.82. The MEDE was pseudostratified, and consisted of four cell types: Type I and II, which were columnar cells without basal infoldings, basal and goblet cells. The most characteristic feature was the presence of well‐developed lateral interdigitations between Type I and II cells. © 1993 Wiley‐L

ISSN:0003-276X    

DOI:10.1002/ar.1092360402

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1993

数据来源: WILEY

摘要:

AbstractUsing digital image analysis and several anatomical methods, morphometric analysis of nonspanning fibers which had tapering profiles at their intrafascicular termination sites and represented overlapping arrangements within the fiber fascicles was performed in the rat rectus abdominis. Special emphasis was focused on dimensional relationships occurring between overlapping portions and tapering segments and sarcomere lengths in non‐ and overlapping portions. Nonspanning fibers were found to overlap each other for more than 40% of their length. In length, their overlapping portions generally corresponded to their tapering segments, which were also greater than 40% of the fiber length. In addition, despite the presence of overlapping linkages, nonspanning fibers maintained a fairly uniform length irrespective of their overlapping and non‐overlapping portions. Overlapping linkages in fibers without tapering profiles have a larger cross‐sectional area in the overlapping portion than in the non‐overlapping one, resulting in a phenomenon which will cause different sarcomere lengths between the two portions during fiber stretching. The present results suggest that tapering profiles in the overlapping portion ensure uniform sarcomere lengths within nonspanning fibers, thereby providing mechanical stability in each fiber. © 1993 Wiley

ISSN:0003-276X    

DOI:10.1002/ar.1092360403

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1993

数据来源: WILEY

摘要:

AbstractMuscle cell fiber types in gracilis, rectus femoris, and long head of triceps brachii muscles of ferrets and dogs were identified on serial sections stained for myosin ATPase after preincubation at pH values of 9.8, 4.6, and 4.3 and for NADH‐tetrazolium reductase (NADH‐TR) activity. Although fiber types I and II were identified, the ATPase stain did not demonstrate classic type IIA/IIB fiber differences in either species. However, two type II fiber subtypes could be distinguished in the ferret because they differed slightly in staining intensity with ATPase at pH 4.3 and markedly with NADH‐TR. One ferret type II fiber (designated II dark or IID) was smaller, slightly darker on ATPase, more oxidative on NADH‐TR, and comprised more muscle volume than the other type II fiber (designated II light IIL). The IID fibers of ferret may represent the IID/X fibers of other authors. Both ferret type II fiber subtypes stained darker at pH 4.3 than canine II fibers. The NADH‐TR staining indicated high oxidative activity in canine and ferret type I fibers. In contrast, type II fibers in the dog and IIL fibers in the ferret were moderately oxidative. Canine type IIC fibers were intermediate between type I and type II, whereas in the ferret, type IIC fibers were highly oxidative, as were type IID fibers. Ferret muscles are more oxidative than canine muscles according to NADH‐TR staining. Also, ferret muscles possess 40–100% higher citrate synthase activity as compared to canine muscles. © 1993 W

ISSN:0003-276X    

DOI:10.1002/ar.1092360404

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1993

数据来源: WILEY

摘要:

AbstractSP‐10 is a sperm‐specific, intra‐acrosomal protein that is considered to be a vaccine candidate for immunocontraception. In the present study, in situ hybridization with biotin and35S labeled riboprobes was used to determine the pattern of SP‐10 mRNA expression in human testes. Both methods demonstrated SP‐10 mRNA primarily in round spermatids found in stages I, II, and III of the seminiferous cycle. Morphometric analysis of silver grains with the35S‐labeled probe showed less SP‐10 mRNA in spermatids at stages IV, V, and VI than in previous stages, and rarely was label found in spermatogonia or spermatocytes. The expression of SP‐10 mRNA first appeared at stage I coincident with the appearance of the protein, which was shown previously to persist in the acrosomal matrix throughout spermiogenesis. The decrease in SP‐10 mRNA occurred when spermatids underwent polarization, nuclear condensation, and elongation. The appearance of SP‐10 mRNA in round spermatids suggest that increases in SP‐10 transcription or SP‐10 mRNA stability or both occur as spermatids develop from the Golgi phase to the cap phase. The subsequent decline of SP‐10 mRNA, despite the persistence of the SP‐10 protein in all spermatids, suggests that a decrease in SP‐10 transcription or an increase in mRNA degradation occurs when spermatids elo

ISSN:0003-276X    

DOI:10.1002/ar.1092360405

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1993

数据来源: WILEY

摘要:

AbstractThe volumetric composition of the human ovary during the compartmentalization stage has been investigated using current stereological methods. Eight left ovaries removed from three fetuses (developmental age 20–25 weeks), four neonates, and one 8‐month‐old child all with a 46, XX karyotype, free from malformations of the genital apparatus, were completely cut obtaining serial sections and one 1 μm‐thick section every 1,000 μm was examined. Ovarian volume was 30 mm3at the 20th week of development, 36 mm3at the 25th week, 129 mm3at birth, and 287 mm3at the eighth postnatal month. The primitive cortical tissue was the largest component of the fetal ovaries (17 mm3, corresponding to 60.2% of the organ). The second component was the interstitium (21% of the organ), followed by the medulla (11.8% of the organ). The primordial follicles occupied a small part of the organs: 1.8 mm3at 20 weeks and 3.4 mm3at 25 weeks (respectively 6.7% and 5.4% of the volumes of the relevant ovaries). At birth, most of the organ was composed of interstitial tissue (57 mm3, 44.2% of the volume) followed by the medulla (25 mm3, 20.3% of the volume). The germinal tissue occupied 46 mm3, mainly primitive cortical tissue (14.9% of the ovary) and primordial follicles (16.3% of the ovary), with a minor contribution from the antral follicles (about 3% of the ovary). At 8 months, the somatic tissue formed the majority of the organ (143 mm3of stroma, corresponding to about 50% of the volume, and 43 mm3of medulla, about 15% of the volume); the germinal tissue occupied about 101 mm3: most of this volume was given by the antral follicles (28.6% of the ovarian volume). © 1993 Wiley

ISSN:0003-276X    

DOI:10.1002/ar.1092360406

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1993

数据来源: WILEY

摘要:

AbstractInsulin‐like growth factor I (IGF‐I) is a 70 amino acid, mitogenic polypeptide, which, in mammals, acts through an endocrine, paracrine, and/or autocrine pathway to regulate growth and development. The primary goal of this study was to determine whether or not IGF‐I‐like immunoreactivity is present in the oviduct of the vitellogenic American alligator,Alligator mississippiensis, and if immunoreactivity patterns vary among the three functional oviducal regions: the albumen‐secreting tube region, the anterior, fiber‐secreting uterus, and the posterior, calcium‐secreting uterus. Immunolocalization of IGF‐I‐like immunoreactivity was accomplished using a polyclonal antihuman rabbit antiserum with an immunoperoxidase staining system. IGF‐I‐like immunoreactivity was detected in all three oviducal regions of the vitellogenic alligator. The presence of IGF‐I‐like immunoreactivity in the oviduct suggests this hormone could function in the growth and proliferation of the alligator oviduct. Furthermore, the presence of IGF‐I‐like immunoreactivity in the tubal glands, which secrete components of the egg white, suggests that growth factors such as IGF‐I may be synthesized by these glands and incorporated into the albumen during egg fo

ISSN:0003-276X    

DOI:10.1002/ar.1092360407

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1993

数据来源: WILEY

摘要:

AbstractUsing a collagenase trypsin‐EDTA treatment, we have been able to successfully isolate and grow primary cultures of the lymphatic endothelium (LEC) that were subcultured, frozen for storage, subsequently thawed with good recovery and growth, and serially subcultured. The morphological features of cultured LEC were consistent with that observed for the endothelium of intact lymphatic vessels. A prominent feature of growing cultures was the appearance of large vacuoles in the perinuclear region of the cytoplasm, which became filled with fluid and cell debris engulfed from the culture medium. The basal cell surface lacked a well defined basal lamina and anchoring filaments were observed extending from the basal plasmalemmal surface into the underlying substratum. LEC in cultures were also positive for Factor VIII‐related antigen. However, specific granules, characteristic of Weibel‐Palade bodies were not observed in ultrathin sections of confluent cultures. F‐actin was identified in LEC cultures using fluorescein phalloidin, and in confluent cultures actin filaments were located at the periphery of the cell as a continuous circumferential thin band and short filamentous bundles in the central part of the cell. By using heparin and endothelial cell growth supplement in the culture medium we have been able to grow stable cultures of lymphatic endothelial cells that could be maintained when serially subcultured for over two years. These LEC cultures provide an in vitro model for investigating the function and biochemical properties of the lymphatic endothelium. © 1993 Wiley

ISSN:0003-276X    

DOI:10.1002/ar.1092360408

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1993

数据来源: WILEY

摘要:

AbstractThree‐dimensional organization of structures labeled by horseradish peroxidase as a tracer molecule in rat aortic endothelium was examined to elucidate the transport pathways for macromolecules. Aortic endothelium was divisible morphologically into four distinct parts, i.e., the parajunctional region (JR), peripheral region (PR), organelle region (OR), and nuclear region (NR). Almost all vesicles, intercellular clefts, and phagosomes were labeled by horseradish peroxidase. Peroxidase‐positive vesicles tended to gather in the PR, occasional JR, and the upper part of the NR. Ultrathin serial micrographs revealed the transcellular channels composed of vesicles in the PR and JR, and the paracellular channels composed of the intercellular cleft without constrictions of tight and gap junctions. Transcellular channels were subdivided into three morphologically different types, where not only vesicles but invagination of abluminal membrane and intercellular cleft occasionally participated in their formation. Three‐dimensional reconstructions from three series of consecutive electron micrographs revealed that almost all peroxidase‐positive vesicles were connected directly or indirectly with the cell surface. These results indicate that the transcellular and paracellular channels are the transport pathways for macromolecules in the aortic endothelium and may suggest that the “shuttle” hypothesis is unsuitable to explain transport system for macromolecules because it postulates the existence of many free vesicles in the cytoplasm. © 1993 Wil

ISSN:0003-276X    

DOI:10.1002/ar.1092360409

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1993

数据来源: WILEY

摘要:

AbstractIn the literature, discussions continue on the question whether the distal portion of the cardiac outlet segment (ventriculoarterial portion, outflow tract of the embryonic heart) is subject to a shortening (absorption, retraction) during development. In 28 human embryos ranging from 4–42 mm crown‐rump length, stereological estimates of volume fractions and surface densities were used to calculate the diameter and the length of the distal outlet segment and their changes during development. A significant increase was found in the wall thickness of this segment, whereas its length remained about the same. An actual shortening was not found. It is concluded that the relative change in proportions is the cause of the disagreements. It is further concluded that there is still a mechanical role for the aorticopulmonary septum in maintaining the length of the outlet segment during growth of this region. © 1993 Wiley‐Lis

ISSN:0003-276X    

DOI:10.1002/ar.1092360410

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1993

数据来源: WILEY

摘要:

AbstractIn the pars distalis of the pituitary gland in adult and embryonic dwarf (dw/dw) mutant mice, ambiguous cells exhibiting ultrastructural features common to growth hormone (GH) cells and prolactin (Prl) cells were analyzed by means of colloidal gold ultrastructural immunocytochemistry in order to define the functional nature of these peculiar cells. Adult and 18‐day embryonic pituitaries from normal (+/+;dw/+) and dwarf (dw/dw) mice were processed with antibodies to GH, Prl, TSH (thyroid‐stimulating hormone), ACTH (adrenocorticotropic hormone), LH (luteinizing hormone), FSH (follicle‐stimulating hormone), and HCG (chorionic gonadotropic hormone). In the adult and embryonic dwarf pituitaries, the ambiguous cells reacted negatively to all of the antibodies except for anti‐ACTH, which labeled them well. In addition, the ACTH‐positive cells showed a much wider variety of shapes and granule size and distribution, as compared with normal adults. In the embryos, this variability in ACTH cell morphology occurred not only in dwarf embryos, but in their normal counterparts as well. The results thus suggest that adult dwarf pituitaries may retain an embryonic or incompletely differentiated form of ACTH cells. © 1993 Wiley

ISSN:0003-276X    

DOI:10.1002/ar.1092360411

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1993

数据来源: WILEY