ISSN:0003-276X    

DOI:10.1002/ar.1092250214

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

年代:1989

数据来源: WILEY

摘要:

AbstractThere is little information concerning the effect of altered occlusal forces on the turnover of collagenous proteins of transseptal fibers of the periodontium. In the present study, hypofunction was induced in rats by extraction of the maxillary teeth, allowing the mandibular teeth to supererupt (hypofunctional side, herein). The contralateral side served as an internal control, although it was likely experiencing occlusal hyperfunction (hyperfunctional side, herein). Untreated animals were also studied (external controls, herein). Animals were injected with3H‐proline and silver grains were counted on radioautographic preparations. The study demonstrated significant differences in the synthesis and degradation of collagenous proteins coincident to altered occlusal function;3H‐proline was most heavily incorporated into the transseptal fibers of hyperfunctional and least rapidly into the external control tissues (P<.001). Significant differences in grain counts were evident during the first 3 weeks after injections. Collagenous proteins were degraded most rapidly in transseptal fibers of the hyperfunctional and least rapidly in hypofunctional tissues (P<.001). The study also demonstrated regional variability in the turnover of labeled collagenous proteins, that is, proteins were synthesized and degraded most rapidly in the middle third and least rapidly in the mesial third of the ligament (P<.001). “Whole” counts (mean of counts over middle, mesial, and distal thirds) were not similar to those of any specific region and could provide erroneous information concerning remodeling of collagenous proteins of transseptal fibers. Transseptal fibers, labeled by the3H‐proline pulse, migrated occlusally with the teeth; new transseptal fibers and bone were formed at the crest of the interdent

ISSN:0003-276X    

DOI:10.1002/ar.1092250202

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

年代:1989

数据来源: WILEY

摘要:

AbstractCollagen fibrils were present within membrane‐bound vacuoles in the cytoplasm of mouse‐decidual cells on the 7th day of pregnancy. The space between the vacuole membranes and the fibrils was narrow and frequently filled with a granular electron‐dense material. The loss of banding of the collagen fibrils, their association with lysosomelike bodies, and the demonstration of acid phosphatase activity in the vacuoles indicate that the fibrils were internalized by the decidual cells and were being digested. It is suggested that phagocytosis of collagen is a mechanism of remodeling of the mouse de

ISSN:0003-276X    

DOI:10.1002/ar.1092250203

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

年代:1989

数据来源: WILEY

摘要:

AbstractIn the rat, as in most other polytocous species, fetuses tend to be relatively evenly spaced along the uterine horn, porhaps to minimize possible effects of local overcrowding on placental function and fetal growth. Here we administered 2 mg of indomethacin, in split doses on day 5 of gestation, in an attempt to disturb evenness of spacing and so reveal local overcrowding effects, if any. The effects on spacing, expressed as the coefficient of deviation of distances between neighboring implants (CVd%) and correlations between fetal and placental weights and distance to neighbors, was examined on day 16 and day 22 of gestation to cover the period of rapid fetal growth. Indomethacin markedly affected evenness of spacing; at day 16, CVd% increased from a control value of 19.2 to 50.8% and at day 22 from 27.5 to 41.2%. Despite the increased variability of spacing and consequent local crowding, including examples of conjoined placentas in the treated rats, there was no evidence that these local factors affected placental growth or weight of individual fetuses. Indomethacin, however, had a general effect on placental and fetal growth. At day 16, mean fetal weights were retarded but by day 22 had caught up to those of control litters, and this was accompanied by significant placental hypertrophy. Collectively, these results show that the uterus has sufficient reserve to cope with relatively uneven spacing of fetuses and have provided a model for examining catch‐up growth of fetuses and accompanying placental change

ISSN:0003-276X    

DOI:10.1002/ar.1092250204

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

年代:1989

数据来源: WILEY

摘要:

AbstractThe bovine cervical mucosa was investigated with respect to structure, mucus secretory pattern, and sperm transport. Structural investigation included stereomicroscopic examination of surface‐stained tissue blocks and graphic reconstruction of serial sections by using both computer‐generated and Plexiglas models. Histochemistry of the mucosa was evaluated in follicular‐and luteal‐phase animals. Alcian blue, periodic acid Schiff, and high‐iron diamine were utilized to distinguish sialomucins, sulfomucins, and neutral mucins. Location and orientation of cervical sperm in follicular phase animals were evaluated 12 h postmating by using light and electron microscopy. Cervical mucosa was characterized by longitudinal primary folds, most of which maintained continuity throughout the cervix. Superimposed on these were secondary folds which varied in length and depth. Abundant, shallow, uniformly spaced, and parallel longitudinal “grooves” covered all surfaces. Grooves had greater continuity in regions distal, as opposed to proximal, to the cervical canal. Blind‐ending glands or crypts were not apparent. Follicular‐stage cervices exhibited a pronounced sialomucin production in basal areas within grooves while neutral and sulfomucins were predominant in apical areas. In luteal‐phase animals, basal sialomicin production was markedly decreased while sulfated and neutral mucins remained abundant. Numerous cranially oriented spermatozoa were observed within the shallow grooves of cervical folds (sialomucin‐rich areas) in mated animals and were unidirectionally opposed to ciliary beat. It appeared that privileged paths for transport of viable spermatozoa may originate in the fornix vagina, extend through longitudinal primary folds at the external os, and progress to the uterus within continuous sialomucin‐rich channels which are associated with basal areas of the shallow grooves, dista

ISSN:0003-276X    

DOI:10.1002/ar.1092250205

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

年代:1989

数据来源: WILEY

摘要:

AbstractA single injection of estradiol valerate (EV) produces a polycystic ovarian (PCO) condition in the rat. The development of the PCO condition coincides with alterations in the endogenous plasma gonadotropin patterns, suggesting that PCO may be a response to abnormal gonadotropin stimultion. Other factors, however, such as direct autonomic innervation, also contribute significantly to the regulation of the ovary and could be important in generating and/or maintaining PCO. We have, therefore, removed and autotransplanted one ovary in each of eight rats under the capsule of the ipsilateral kidney, thus totally disrupting its innervation. The animals were injected with EV and both ovaries of each animal were examined 8 weeks later. In a second group of animals, we induced the PCO condition, autotransplanted one polycystic ovary in each animal under the kidney capsule, and examined the ovaries 2 weeks later. In both groups the autotransplanted ovaries exhibited the full range of polycystic morphology, as did the intact ovary in each animal. We conclude that since a major perturbation in innervation affects neither the development nor the maintenance of PCO, autonomic innervation does not play a crucial role in this disorder.

ISSN:0003-276X    

DOI:10.1002/ar.1092250206

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

年代:1989

数据来源: WILEY

摘要:

AbstractTo confirm whether the Paneth cells of mice (ICR, male, 10–12 weeks old) have the same secretory response to hormonal and cholinergic stimulation as do pancreatic acinar cells, ultrastructural changes of Paneth cells and pancreatic acinar cells 1 hr after administration of various doses of cholecystokinin (octapeptide, CCK‐8) and carbamylcholine were morphometrically assessed. After maximal (1.5 μg/kg intraperitoneally [i.p.]) and supramaximal (15 μg/kg, i.p.) stimulation by CCK‐8, pancreatic acinar cells showed, respectively, degranulation or disturbance of secretion (e.g., an increase in lysosome‐like bodies, aggregation of zymogen granules). The Paneth cells, however, were almost unchanged in the parameters examined. After carbamylcholine injection (1,000 μg/kg, subcutaneously [s.c.]), both pancreatic acinar cells and Paneth cells showed degranulation. Paneth cells sometimes developed large vacuoles, probably formed after massive exocytosis; such vacuoles were not observed in pancreatic acinar cells. It is suggested that Paneth cells and pancreatic acinar cells have different secretory responses. Paneth cell secretion, which possibly plays a role in controlling the intestinal bacterial mileu, may be stimulated by cholinergic rather than hormonal

ISSN:0003-276X    

DOI:10.1002/ar.1092250207

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

年代:1989

数据来源: WILEY

摘要:

AbstractCell distribution and the effects of 12 daily injections of 80 mg/kg pilocarpine or 5 mg/kg atropine were studied in rat tracheal epithelium. Ciliated, periodic‐acid‐Schiff‐positive (PAS+), Alcian blue‐positive (AB+), nonstaining, and basal cells were counted and their order of occurrence was recorded. Pilocarpine caused a decrease in ciliated and an increase in PAS+, basal, and nonstaining cell numbers. Atropine caused similar changes, although to a much lesser extent. AB+ cells were rare. Cell occurrence was randomized by computer, and comparisons with nonrandomized counts were made to discern between 1) differences in cell arrangement owed to variations in cell numbers, and 2) actual biases in cell distribution. In general, ciliated areas amounted to a few cells and were separated by nonciliated patches of comparable size. The grouping characteristics of cells supported the notion that basal cells were surrounded by their progeny and that daughter cells were displaced by siblings. It was concluded that the cells were not randomly distributed. Basal cells were dispersed, and probably immediately related to PAS+ cells but not to ciliated cells. A bias toward grouping implied concurrent differentiation of clusters of sibling cells. With drug treatment, a substantial increase in PAS+ cells without increase in cell concentration suggested a decrease in ciliated cell differentiation. Larger groups of secretory cells with treatment suggested cell division without differentiation through the basal cell pathway. Cholinergic agents were not the predominant modulators of this epithelium, and their effect was probably secondary to influence over mucociliary f

ISSN:0003-276X    

DOI:10.1002/ar.1092250208

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

年代:1989

数据来源: WILEY

摘要:

AbstractNeuroepithelial endocrine (NEE) cells were for the first time identified in the lung of the entirely aquatic urodele,Ambystoma mexicanum, by using light and electron microscopy, histochemistry, and immunocytochemistry. In the basal part of the ciliated epithelium and, less often, in the respiratory portion of the lung, NEE cells were found to occur both solitarily and in small clusters. No typical neuroepithelial bodies could be found. Using the method of Fernandez Pascual, some NEE cells were found to be argyrophilic. Microspectrofluorimetric analysis of formaldehyde‐induced fluorescence and immunocytochemistry revealed the presence of 5‐hydroxytryptamine. With antibodies to neuron‐specific enolase only a few NEE cells exhibited a faint immunostaining. Electron‐microscopically, the NEE cells are provided with distinctive cytoplasmic membranebound dense granules of variable size, which gave a positive argentaffin reaction. The images of emiocytotic granule release are indicative of a secretory function. In the tracheal epithelium, NEE cells seem to occur only solitarily. They bear the same ultrastructural characteristics as the intrapulmonary NEE cells but here, the dense granules are larger and associated with numerous bundles of microfilaments. Intraepithelial nerve endings were observed near the airway lumen. Between nerve terminals and NEE cells, synaptic complexes with aggregations of clear‐centered vesicles close to the presynaptic membrane thickenings were observed. In addition, some nerve endings from “reciprocal synapses” with NEE cells. A receptosecretory function for NEE cells in the lung ofA. mexican

ISSN:0003-276X    

DOI:10.1002/ar.1092250209

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

年代:1989

数据来源: WILEY

摘要:

AbstractThis paper demonstrates the presence of areas where endocardial cells are aligned with the blood flow in three distinct regions of the embryonic chick heart: on the inferior border of the growing septum primum, on the upper wall of the primitive ventricle above the developing interventricular septum, and on the part of the atrial floor that funnels into the atrioventricular canal. While orientation in the first two areas is transitory, the number of cells aligned with the blood flow in the atrial floor increases from days 3 to 5 of incubation. It is suggested that shear stress induces endocardial cell orientation in these areas. To further explore the role of hemodynamics in endocardial cell arrangement, the left of the vitelline vein was severed at stages 13–14. This resulted in abnormal development of the vitelline venous system. Examination of experimental embryos at 5 days of age revealed the presence of a distinct area of endocardial cell orientation in the dorsal wall of the right atrium, near the opening of the sinus venosus. Changes in the venous return to the atria may modify flow patterns, thus inducing endocardial cell orientation. This experimental procedure may be a useful model not only for exploring the effects of hemodynamics upon the endocardium, but also for investigating other aspects of heart development under altered hemodynamic conditions, without manipulating any portion of the embryonic hear

ISSN:0003-276X    

DOI:10.1002/ar.1092250210

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

年代:1989

数据来源: WILEY