bluuebunny/crossref_metadata_2025 huggingface dataset:
Ultrastructure as a basis for dating of rat endometrium
Authors: Spornitz U. M. , Rinderknecht B. P. , Edelmann A. , Scheidegger B. , Cairoli F.
Published: February 2005

Studies on the endometrial cycle depend upon the precise dating of the cycle stage. In the present paper the generally applied method of vaginal smear was carefully verified through the measurement of the hormones relevant to the endometrial cycle. From rats predated through vaginal smear cytology, the hormone levels of estradiol‐17‐beta (E2) and progesterone (P), luteinizing hormone (LH), and follicle stimulating hormone (FSH) were measured. The values obtained were then compared to the standardized values of our reference curve. Animals with values that did not fit within the standard deviation of our reference curve were excluded from this investigation. Thus, for the first time exactly dated rat endometrial morphology was studied with electron microscopy. The morphology of the surface epithelium of rat endometrium from all four stages of the cycle is described in detail. In addition, a semiquantitative morphometric analysis of the following parameters was performed: cell volume, nuclear volume, the volume density of secretory granules, digestive vacuoles, mitochondria, Golgi apparatus, rough endoplasmic reticulum, and lipid vacuoles as well as the size of lipid vacuoles. With the cellular content of lipid vacuoles and their diameter, it is possible to differentiate between proestrus/estrus and diestrus I/diestrus II, the latter possessing definitely more and larger lipid vacuoles. During estrus the greatest cytoplasmic volume develops. In addition to this, secretory granules are only present during estrus. Finally, diestrus I can be well differentiated from diestrus II, because diestrus I exhibits more digestive vacuoles and during diestrus II a high percentage of free ribosomes is present. On the basis of distinct morphological features, described in this paper, it is now clearly possible to distinguish between the four different cycle stages. © 1994 Wiley‐Liss, Inc.
Postnatal differentiation and development of the rat epididymis: A stereological study
Authors: Jiang F. X. , Temple‐Smith P. , Wreford N. G.
Published: February 2005

Postnatal development and differentiation of the rat epididymis was studied in the rat from 15 to 120 days of life using stereological techniques. Both the relative volume (volume density) and absolute volume of the epithelial, interstitial, and luminal compartments in the initial segment, caput, corpus, and cauda epididymides were determined. In all segments the volume density of the epithelial compartment increased between days 15 and 30 before falling to adult values at 45 days in the initial segment (0.476 ± 0.031), at 60 days in the caput (0.258 ± 0.028) and at 90 days in the corpus (0.245 ± 0.007) and cauda (0.140 ± 0.004). The relative volume of the interstitium decreased, whilst that of the lumen increased over the same period with adult values being achieved earlier in the proximal segments than in the distal segments. In contrast to volume fraction the absolute volume of all compartments in all segments increased from day 15 to day 90. Between 90 and 120 days the absolute volumes of compartments in the initial segment and caput showed little volume change. All compartments in the corpus and cauda showed significant increases in volume over the same period. A similar pattern of development was observed with respect to the surface area of both the luminal and basement membrane aspects of the epithelium; surface area per unit volume (surface density) in all segments reached adult values at approximately 60 days, whilst the increase in absolute area of the surfaces ceased at 90 days in the initial segment and caput and continued to 120 days in the corpus and cauda. The total length of the epididymal tubule showed the same pattern with no increase in length apparent in the initial segment and caput after 90 days. Length however continued to increase in the corpus and cauda between 90 and 120 days. Tubule and luminal diameter reached their definitive values in the initial segment on day 60 but continued to increase until day 90 in the distal segments. Epithelial height increased between 15 and 30 days in all segments; in the caput, epithelial height was greatest on day 30 before decreasing slightly; and in the corpus and cauda maximal epithelial height was observed on day 45 decreasing to stable values on day 60 and 90, respectively. All the data is consistent with a proximal to distal differentiation and development of the epididymis with growth continuing in all segments after the establishment of the definitive architecture. Growth of the distal segments continued after its cessation in the proximal segments. © 1994 Wiley‐Liss, Inc.
Quantitative study on the relation between structural and functional properties of the hearts from three different mammals
Authors: Kim Ho‐Dirk , Kim Chul Ho , Rah Bong‐Jin , Chung Hae‐Ik , Shim Tae‐Sub
Published: February 2005

The ultrastructural quantitative composition of left ventricular cardiac myocytes from isolated Langendorff‐perfused hearts was studied in three different mammals (rabbit, guinea pig, and rat). Volume densities of mitochondria, myofibrils, and unspecified cytoplasm were determined using morphometry and were compared to functional parameters including left ventricular developed pressure (LVDP), contractility (dP/dt), heart rate, TTI (tension‐time index, an index of oxygen consumption), and relative heart mass (H/B) obtained from these hearts. Each of the mammals was found to possess a very specific and characteristic quantitative composition of cardiac myocyte. Cardiac myocytes contained 26.8% mitochondria and 56.3% myofibrils in rabbits, 25.8% mitochondria and 60.9% myofibrils in guinea pigs, and 27.7% mitochondria and 58.1% myofibrils in rats. The LVDP, contractility, heart rate, and TTI were quite different among species. However, there were close correlations between the mitochondrial volume density and the LVDP (p < 0.05), and between the mitochondrial volume density and the TTI (p < 0.05), in any group of the animals. It is concluded that the mitochondrial volume density is a good indirect indicator of function of cardiac muscle related to oxidative capacity. © 1994 Wiley‐Liss, Inc.
Calmodulin immunoreactivity in the chicken pineal gland: Comparison with calbindin‐D28k, calretinin, and S100
Authors: Bastianelli Enrico , Pochet Roland
Published: February 2005

Calmodulin distribution in the chicken pineal organ was investigated by immunohistochemistry. Calmodulin immunoreactivity was detected in ependymocytes in the follicular zone and in interstitial cells in the parafollicular zone. No calmodulin immunoreactivity was detected in pinealocytes. Lack of calmodulin immunoreactivity in pinealocytes raises questions about its proposed function in melatonin synthesis as suggested by pharmacological studies using calmodulin antagonists. The calmodulin distribution was comparable to that of S100, a glial cell marker. Two other markers, calbindin‐D28k and calretinin, which in neuroanatomical studies give excellent cytoarchitectonic staining, in the chick pineal permitted the detection of two subclasses of pinealocytes. One was darkly stained by calbindin‐D28k and rare. The other was very abundant and calretinin positive. In the parafollicular zone, calbindin‐D28k and/or calretinin antibodies allowed us to visualize cells presenting a neuron‐like morphology. Calretinin immunoreactivity was detected in nearly all pinealocytes in which hydroxy‐indol‐O‐methyl transferase was also located. Comparison between the lack of calmodulin and the presence of calretinin, belonging to the same calcium‐binding protein family, in chick pinealocytes raises the hypothesis about a possible role of calretinin in melatonin synthesis. © 1994 Wiley‐Liss, Inc.
Size‐selective comparison of fetal calvarial versus adult marrow osteogenic colony‐forming entities
Authors: Dutra Timothy F. , Bernard George W.
Published: February 2005

Background: This experiment was designed to test whether a single cell suspension of adult marrow‐derived cells will form mineralized bone nodules in vitro. Methods: At the time of plating, cellular dispersions of either young adult rabbit bone marrow cells or, as controls, of fetal mouse calvarial cells were size‐selected by sieving through various poresize plastic meshes. Results: When marrow‐derived cells were passed through a 105 μm pore‐size mesh, fibroblastic cell cultures grew in vitro in six of six attempts; however, marrow cell clusters backwashed off 105 μm pore‐size meshes produced osteogenic colonies in vitro in six of six trials. Fetal calvarial cells filtered through a 30 μm pore‐size mesh yielded osteogenic nodules in culture in six of six tests. Conclusions: For adult bone marrow, cell clumps or clusters larger than 105 μm produced bone colonies under standard cell culture conditions, whereas for fetal calvarial cells, the initiating agent was smaller than 30 μm. © 1994 Wiley‐Liss, Inc.
A morphological study of the lymphocyte traffic in Peyer's patches after an in vivo antigenic stimulation
Authors: Regoli Marì , Borghesi Chiara , Bertelli Eugenio , Nicoletti Claudio
Published: February 2005

Background: Lymphoid cells have often been observed in the intestinal lumen and it has been hypothesized that M cells could represent one of the most important migration routes for the immunocompetent cells from the lymphoid follicle to the lumen. However, a direct evidence of the passage was lacking. In this study we describe a morphological analysis of the lymphocyte traffic in rabbit Peyer's patches after an in vivo stimulation with an antigen normally not present in the intestine.

Methods: The antigenic stimulation of a large number of Peyer's patches was carried out using the isolated ileal loop technique and then the samples from stimulated and control Peyer's patches were analysed by light and transmission electron microscopy.

Results: We have been able to describe details of lymphocyte migration through M cells, from the follicle to the intestinal lumen, and a marked increase of intraluminal lymphocytes by counting the immunocompetent cells after periods of antigenic stimulation of varying lengths.

Conclusions: Our finding is that the passage of lymphocytes to the lumen is an antigen‐dependent event and we also provide direct evidence that M cells are one of the migration routes. Our observations also indicate that lymphoid cells in the intestinal lumen may play an immunologic role in mucosal immunity. © 1994 Wiley‐Liss, Inc.
The peripheral cytoplasm of adrenocortical cells: Zone‐specific responses to ACTH
Authors: Loesser Kathryn E. , Cain Lisa D. , Malamed Sasha
Published: February 2005

Background: Differences in the cytoskeletal protein actin in cells from the zona glomerulosa and zona fasciculata would be of considerable interest because there is persuasive evidence that rat corticosteroids are secreted by mechanisms that are somewhat zone‐specific. We have previously shown evidence that actin may be involved in steroid secretion, possibly in connection with changes in adrenocortical microvilli. However, the cells upon which the data were based were not separated according to zone of origin.

Methods: Immunogold electron microscopy and morphometric procedures were used to determine whether ACTH‐induced changes in the peripheral cytoplasm of isolated adrenocortical cells occur in both zona fasciculata and zona glomerulosa cells.

Results: Actin immunoreactivity was more concentrated in the cytoplasm adjacent to the plasma membrane (including the cytoplasm within the microvilli) than it was in the internal cytoplasm in cells from both zones (4–6 times more concentrated in zona glomerulosa cells and 3–6 times more concentrated in zona fasciculata cells). However, the mean aggregate microvillar surface length (microvillar index) of untreated zona fasciculata cells previously reported (Loesser and Malamed, 1987) was 23% greater than that of untreated zona glomerulosa cells. Although ACTH (at a maximal steroidogenic concentration) had no effect on the peripheral cytoplasmic actin concentration of zona glomerulosa cells, there was a 24% increase in the aggregate microvillar length. In contrast, in zona fasciculata cells, ACTH treatment was accompanied by an increase in peripheral cytoplasmic actin concentration of 58–64% and an increase in aggregate microvillar surface length of 40% (previously reported (Loesser and Malamed, 1987)), almost twice that for zona glomerulosa cells.

Conclusion: The results suggest that ACTH‐induced hormone release from zona fasciculata cells is mediated by increases in peripheral cytoplasmic actin and aggregate microvillar length; in zona glomerulosa cells such changes are small or absent. © 1994 Wiley‐Liss, Inc.
Quantitative analyses of cell behaviors underlying notochord formation and extension in mouse embryos
Authors: Sausedo Roger A. , Schoenwolf Gary C.
Published: February 2005

Background: Formation and extension of the notochord (i.e., notogenesis) is one of the earliest and most obvious events of axis development in vertebrate embryos. In birds and mammals, prospective notochord cells arise from Hensen's node and come to lie beneath the midline of the neural plate. Throughout the period of neurulation, the notochord retains its close spatial relationship with the developing neural tube and undergoes rapid extension in concert with the overlying neuroepithelium.

Methods: In the present study, we examined notochord development quantitatively in mouse embryos. C57BL/6 mouse embryos were collected at 8, 8.5, 9, 9.5, and 10 days of gestation. They were then embedded in paraffin and sectioned transversely. Serial sections from 21 embryos were stained with Schiff's reagent according to the Feulgen‐Rossenbeck procedure and used for quantitative analyses of notochord extension.

Results: Quantitative analyses revealed that extension of the notochord involves cell division within the notochord proper and cell rearrangement within the notochordal plate (the immediate precursor of the notochord). In addition, extension of the notochord involves cell accretion, that is, the addition of cells to the notochord's caudal end, a process that involves considerable cell rearrangement at the notochordal plate‐node interface.

Conclusions: Extension of the mouse notochord occurs similarly to that described previously for birds (Sausedo and Schoenwolf, 1993 Anat. Rec. 237:58–70). That is, in both birds (i.e., quail and chick) and mouse embryos, notochord extension involves cell division, cell rearrangement, and cell accretion. Thus higher vertebrates utilize similar morphogenetic movements to effect notogenesis. © 1994 Wiley‐Liss, Inc.
Immunocytochemistry of M‐cadherin in mature and regenerating rat muscle
Authors: Bornemann Antje , Schmalbruch Henning
Published: February 2005

Background: Cadherins are transmembrane proteins mediating calcium‐dependent cell–cell adhesion in a cell type‐specific manner by means of homophilic binding. M(muscle)‐cadherin is a recently detected member of the cadherin family.

Methods: We have investigated the localization of M‐cadherin innormal and aneurally regenerating skeletal muscle of rat by means of pre‐embedding immunocytochemistry. The antibody was directed against the extra‐cellular domain of M‐cadherin.

Results: Myoblasts and myotubes in regenerating muscles tended to be arranged in clusters enclosed by a common basal lamina. Satellite cells of mature muscle fibers were attached to the underlying fiber without separating basal lamina. Reactivity for M‐cadherin was restricted to the plasma membranes of myoblasts and satellite cells, and was most intense at the membrane areas facing adjacent myotubes or myofibers. Myoblasts interposed between two myotubes were stained on the entire surface. The adjacent plasma membrane of the otherwise negative myotube or muscle fiber, was stained as well, and extracellular reaction product was in the gap between the cells.

Conclusion: The cellular localization of M‐cadherin may indicate that M‐cadherin is involved in calcium‐dependent adhesion between satellite cells and muscle fibers or, by means of interposed myoblasts, between the clustered myotubes in a regenerating muscle. © 1994 Wiley‐Liss, Inc.
Immunohistological analysis of macrophages, B‐cells, and T‐cells in the mouse lung
Authors: Kolopp‐Sarda Marie N. , Bene Marie C. , Massin Nicole , Moulin Jean J. , Faure Gilbert C.
Published: February 2005

Background: Numerous studies have described the anatomy of the large lymphoid aggregates of bronchus‐associated lymphoid tissue (BALT) in rabbits and rats. Less work has been performed on other immunocompetent areas of the respiratory tract, and available data again mostly describe rabbit or rat tissues. Little is known therefore of the microanatomy of the mouse lung immune system.

Methods: We report a study, devised in order to establish the immunohistological characteristics of normal healthy mice lungs, performed on whole lungs from 22 mice of various strains and/or ages. Snap frozen tissues were serially sectioned and analysed using histochemistry and immunohistological techniques. Scattered macrophages, IgA plasma cells, B and T cells were enumerated in each sample.

Results: The largest population was that of macrophages. B‐cells were numerous in all mice but 3 adults. T‐cells were always present, L3T4+ often more numerous than Lyt2+ cells. Small lymphoid aggregates, composed of B or T cells (L3T4+ and Lyt2+) were seen in all mice, in the vicinity of a bronchiole and a vein. In 12/22 mice, a peculiarly elongated para‐esophagal lymph node with large peripheral B‐cell nodules and medullary T‐cells was observed. In the five strains of mice studied, large variations were noted, affecting all the cell types studied, and related either to age or strain.

Conclusion: Besides providing a qualitative description and quantitative analysis of immunocompetent cells, this work reports age and strain‐related variations in these cells' distribution. These data could be relevant for studies involving the analysis of mice respirtory immune responses to environmental antigens. © 1994 Wiley‐Liss, Inc.
Immunohistochemical studies of renin‐containing cells in the developing sheep kidney
Authors: Kon Yasuhiro , Alcorn Daine , Murakami Kazuo , Sugimura Makoto , Ryan Graeme B. , McCausland Jane , Sawyer Trudy , Kelly Darren
Published: February 2005

Background: Renin‐containing (RC) cells in small ruminant kidneys have been known to be widely distributed along the blood vessels. In the present study, RC cells in developing sheep kidneys were studied to investigate not only the appearance but distribution with the potential physiological significance using immunohistochemical and histophanimetrical techniques.

Methods: Seven fetal, 12 newborn, and 3 adult metanephric kidneys were used and immunostained by anti‐renin antiserum. In the histoplanimetrical analysis, the numerical values of RC cells existing at the walls of 3 major arterial types in the kidneys were calculated.

Results: At day 44 of gestation, RC cells were already demonstrated in the walls of renal, interlobar, and afferent vessels, located in the deep cortex and the medulla. In intermediate gestational periods, RC cells were detected throughout the intrarenal arterial trees. In late gestational periods, RC cells expressed in the walls of interlobar/arcuate and interlobular arteries tended to decrease or disappear gradually, while they were distributed predominantly in the afferent glomerular vessels. In newborn lambs, especially days 1 to 3 after birth, increased numbers of RC cells were demonstrated throughout the arterial trees in the kidneys. In older lambs, RC cells located in the interlobar/arcuate arteries and the proximal region of the interlobular arteries decreased in number and gradually disappeared. Some RC cells were still distributed in the distal portion of the interlobular artery even in the adult sheep.

Conclusions: These results suggest that the wide distribution of RC cells in sheep kidney is formed in perinatal life, and that the neuronal regulation is associated with the maintenance of this distribution. © 1994 Wiley‐Liss, Inc.
Ileal Peyer's patches in pigs: Intercellular and lymphatic pathways
Authors: Lowden Stewart , Heath Trevor
Published: February 2005

Background: The lymphatics of Peyer's patches disseminate immunological information from the gut and thus play a key role in protection of the body against environmental pathogens. The aim of this project was to describe the lymphatic pathways of these Peyer's patches in pigs, and the mucosal intercellular spaces which lead to these lymphatics.

Methods: Ileal tissue from living or freshly killed pigs was examined by light microscopy or electron microscopy, or was injected with Mercox (CL‐2B, Japan Vilene Hospital, Tokyo) for scanning electron microscopy of corrosion casts.

Results: Intercellular fluid between intestinal epithelial cells passes through pores in the basal lamina to mix with that in the intercellular spaces and prelymphatic intercellular channels of the lamina propria and follicle domes. From there, lymph enters lacteals in the villi, or a branching network of vessels within the lamina propria. Small lymphatics penetrate the muscularis mucosae and are continuous with (1) lymphatic vessels which pass directly to the deep submucosa between follicles, or (2) lymphatic sinuses which lie adjacent to the follicles. This differes from the situation in sheep and rabbits. Basal lymphatics beneath the follicles convey lymph to vessels which leave the surface at the serosa.

Conclusion: The differences in the structure and arrangement of the lymphatics of Peyer's patches between pigs, sheep, and rabbits will require further investigation to determine if such variation between species has an effect on the distribution of immune products to effector sites. © 1994 Wiley‐Liss, Inc.
Expression of the cysteine proteinase inhibitor cystatin C mRNA in rat eye
Authors: Barka Tibor , Van Der Noen Hendrika
Published: February 2005

Background: Cystatin C, a naturally occuring inhibitor of cysteine proteinases, belongs to family 2 of the cystatin superfamily. While cystatins in general, and cystatin C specifically, are expressed in various cell types and found in biological fluids, cystatins in ocular structures have not been investigated. In the present study, the expression of cystatin C mRNA in the eye of the rat was studied.

Methods: Total RNA was extracted from eyes as well as from pooled corneae, retinas, lenses, sclerae, and corneae of adult rats. Cystatin C mRNA was detected in the RNA samples by reverse transcriptase—polymerase chain reaction and Northern blot hybridization. In addition, in situ hybridizations of formalin‐fixed cryostat sections were carried out using a digoxigenin‐labeled cystatin C probe.

Results: Cystatin C mRNA was demonstrated in total RNAs extracted from the eye, sclera, and retina, but not in RNAs isolated from the cornea and lens. In situ hybridizations revealed cystatin C mRNA in most of the stromal cells of the sclera. In the retina, a strong signal was localized in the outer nuclear layer. The distribution of the reaction product suggested that in the retina Müller cells and rod cells are the primary sites of expression of cystatin C. In addition, some glial cells in the inner nuclear and ganglion cell layers were stained. No specific signal for cystatin C mRNA was detected in the cornea, lens, iris, ciliary body, and choroid.

Conclusions: In the eye of the rat, significant levels of cystatin C mRNA are detected in the sclera and retina. In the sclera cystatin C may play a role in modulating the activities of cysteine proteinases, mostly cathepsins, involved in the turnover and remodeling of the stroma. In the retina, cystatins synthesized and presumably released by Müller cells and rod cells may have a protective function against the harmful effects of cysteine proteinases released under physiologic and pathologic conditions. © 1994 Wiley‐Liss, Inc.
Perspectives: A biomechanical model of the pathogenesis of arthroses
Authors: Frost Harold M.
Published: February 2005

This model views the common, initiating cause of arthroses as excessive articular cartilage microdamage. If so, understanding it would become a central problem for understanding the pathogenesis of arthroses. The model proposes the microdamge can stem from: (1) Excessive total loads on normal joints; (2) underadaptations in a joint's size or shape that leave its momentarily loaded area too small for normal loads; (3) impaired microdamage repair in subchondral bone or articular cartilage; (4) abnormal composition or structure that makes a tissue develop excessive microdamage under normal loads. (5) (2)–(4) above could stem from changed set points or “lead times” for a joint's adaptations and maintenance, which in turn could stem from (6) genetic influences, some drugs, toxins, diseases, and “X,” and (7) from combinations of the above.

In the pathogenesis of arthroses this model assigns special importance to the stiffness of joint tissues (as distinguished from their strength), to the typical largest unit loads they carry as a result of a subject's usual physical activities, and to microdamage in those tissues. © 1994 Wiley‐Liss, Inc.
Ultrastructural modifications of vesicular and Golgi elements in the Saccharomyces cerevisiae sec21 mutant at permissive and non‐permissive temperatures
Authors: Rambourg A. , Clermont Y. , Jackson C. L. , Képès F.
Published: February 2005

Background: The secretory protein transit between cisternae of endoplasmic reticulum (ER) and Golgi elements is blocked when the yeast Saccharomyces cerevisiae sec21 mutant is shifted from the permissive (24°C) to a non‐permissive (37°C) temperature, but 30–50 nm vesicles accumulate in the cytoplasm. At the semi‐permissive temperature of 33°C there is no complete block but rather a slowdown of the protein transport between ER and Golgi. The purpose of the present investigation is to analyze the structural expression of these events.

Methods: S. cerevisiae sec21 mutants were maintained for 90 min at semi‐restrictive (33°C) or restrictive (37°C) temperatures and then progressively returned to 24°C. Following fixation in glutaraldehyde and a postfixation in potassium ferrocyanide reduced osmium, 0.08 to 0.2 μm thick sections were cut from Epon embedded yeasts. Using the thicker sections, stereopairs of electron microscope photographs were prepared and used to visualize the three‐dimensional configuration of the organelles.

Results: At permissive temperature, the Golgi elements appeared as isolated networks of membranous tubules dispersed throughout the cytoplasm. The diameter of these membranous tubules varied considerably from one Golgi element to another. Larger tubules showed at their intersections distensions with size and staining intensity comparable with that of the secretory granules seen at proximity of the Golgi networks or at the cell periphery. Small vesicles in the 30–50 nm size range were rarely if ever observed in cells grown at permissive temperature. Golgi networks and secretion granules were less conspicuous in mutant cells maintained at 33°C and completely disappeared at 37°C. In both cases, the main structural feature was the presence in the cytoplam of numerous small vesicles and of short membranous tubules with a diameter identical to that of the small vesicles. As soon as 5 minutes after shifting mutants from 33°C to 24°C, the small vesciles disappeared from the cytoplasm, while secretory granules were actively produced in extensively developed Golgi network. When mutants were returned from 37°C to 24°C, the disappearance of small vesicles was more progressive and concomitant with the progressive reconstruction of Golgi networks.

Conclusions: It is thus postulated that, in the above mentioned conditions, the small vesicles of the sec21 mutant did not act as intermediate carriers between the endoplasmic reticulum and a pre‐existing Golgi apparatus, but rather fused together to produce newly formed Golgi networks. © 1994 Wiley‐Liss, Inc.
Endothelial injury following experimental subarachnoid hemorrhage in rats: Effects on brain blood flow
Authors: Clower Ben R. , Yamamoto Yoshihiro , Cain Lisa , Haines Duane E. , Smith Robert R.
Published: February 2005

Background: The leading cause of death and disability in patients suffering from aneurysmal subarachnoid hemorrhage (SAH) is cerebral vasospasm, a persistent, progressive, and often irreversible constriction of cerebral arteries. A wide array of pathological changes occur in cerebral arteries following SAH, with endothelial injury being the earliest and most consistent one. Since intact endothelium modulates many reflexes that influence vascular tone, damage to them may represent a significant contributor to cerebral vasospasm.

Methods: Changes in local cerebellar blood flow (LCBF) and pathological alterations in major cerebral arteries were studied and compared in rats at various time intervals following SAH. SAH induced by the subarachnoid injection of 0.3 ml of whole blood. Sham rats received a subarachnoid injection of 0.3 ml of isotonic saline.

Results: Except for an immediate but transient decrease, LCBF remained unchanged over a 3 day period following saline injection. Likewise, there were no pathological alterations in cerebral arteries of saline‐injected rats. In contrast, the subarachnoid injection of whole blood produced significant changes in both LCBF and cerebral arteries. Within 30 minutes postblood injection, LCBF became significantly decreased and remained so for 4 hours. However, within 24 hours, LCBF had returned to control levels where it remained for 3 days. Endothelial injury was observed in the basilar and middle cerebral arteries from 30 minutes through 4 hours, the same periods in which LCBF was significantly reduced. Within 24 hours, the time period in which LCBF had rebounded to control ranges, cerebral arteries showed no evidence of endothelial damage and resembled control cells.

Conclusion: The results indicate a direct correlation between changes in LCBF and the structural integrity of endothelial cells in the early stages following SAH. The lack of chronically depressed LCBF (after 1 day) may be related to the quick structural repair of endothelium. © 1994 Wiley‐Liss, Inc.
Fine structure of the anteromedial eye of the liphistiid spider, Heptathela kimurai
Authors: Uehara Akira , Uehara Kiyoko , Ogawa Koichi
Published: February 2005

Background: The presence of efferent fibers in the anteromedial eye of liphistiid spiders kept in natural daily cycles of illuminance has been reported. However, this report is limited to innervation by the efferent fiber and daily rhabdomal changes, and there have been no detailed ultrastructural accounts of the eye.

Methods: The fine structure of this eye was examined by electron microscopy.

Results and conclusions: The eye consists of a cornea, a lens, a vitreous body, and a retina. The retina contains 13 or 14 receptor cells and glial cells. The rhabdoms are distal to the nuclei of the receptor cells. In the distal region of the receptive segment, the rhabdomeres lie in the center of the cell. In the middle region, anisomorphic rhabdoms formed by microvilli from adjacent cells are at the cell periphery. In the proximal region, the rhabdomeres are situated in the center of the cell. The ocellar nerve of the eye runs toward the protocerebrum and enters the posterior part of the first optic ganglion of the secondary eyes. Pigmented cells and nonpigmented cells are observed. The pigmented cells are located in the most lateral of the eye and cover the whole eye. The nonpigmented cells are located in the receptor cell bodies and extend to the origin of the ocellar nerve. They wind to form capillaries filled with electron‐dense material. These structures are discussed in comparison with those of other spiders and other chelicerates. © 1994 Wiley‐Liss, Inc.
Differentiation of the chorionic plate of the placenta: Cellular and extracellular matrix changes during development in the macaque
Authors: King Barry F. , Blankenship Thomas N.
Published: February 2005

Background: The chorionic plate forms the fetal side of the placental disc, and its proper growth and development is important to the formation of a normal placenta. The development and structure of the chorionic plate has received little attention. Therefore, we have conducted a developmental and immunohistochemical study of the chorionic plate of the macaque placenta.

Methods: Conventional light and transmission electron microscopy techniques were used to study macaque placental tissues collected from 22 days of gestation to near term. Standard immunoperoxidase methods were used to identify type IV collagen, laminin, and fibronectin in paraffin sections.

Results: Early in gestation the chorionic plate trophoblast consisted of an outer layer of syncytiotrophoblast and a single underlying layer of cytotrophoblast. Beginning at about 100 days of gestation, the cytotrophoblast layer became stratified. The cytotrophoblast cells also became surrounded by variable amounts of extracellular matrix containing type IV collagen, laminin, and fibronectin. Ultrastructurally, the matrix contained abundant 10–12 nm diameter microfibrils. During later gestation the syncytiotrophoblast had a tendency to separate from the cytotrophoblast.

Conclusions: The chorionic plate of the macaque placenta undergoes several distinctive morphological changes over the course of gestation. During the period of rapid diametrical growth of the disc, the chorionic plate trophoblast consists of a layer of syncytiotrophoblast and a single layer of cytotrophoblast. During later gestation the cytotrophoblast layer stratifies at a time coincident with that at which diametrical growth of the disc slows. The cytotrophoblast cells of later gestation appear synthetically active and at least some of their products are extracellular matrix components that encapsulate many of these cells. These components include type IV collagen, laminin, fibronectin, and microfibrils. © 1994 Wiley‐Liss, Inc.
Ontogeny of neurotransmitter systems in the paracervical ganglion and uterine cervix of the rat
Authors: Sullivan Kelli A. , Traurig Harold H. , Papka Raymond E.
Published: February 2005

Background: The paracervical ganglia (PG) are components of the pelvic plexus that provides sensory and motor innervation to the reproductive system of the female rat. Several neurotransmitters including norepinephrine (NE), acetylcholine (ACh), neuropeptide Y (NPY), and vasoactive intestinal polypeptide (VIP) are present in neurons of the adult PG and in axons innervating the adult uterus and uterine cervix. The current study was undertaken to describe the onset of immunoreactivity of these neurotransmitters and neuropeptides during development.

Methods: Female rats, ages E18 to P36, were prepared for immunohistochemistry for TH (tyrosine hydroxylase, a marker of noradrenergic neurons), NPY, or VIP as well as the histochemical demonstration of acetylcholinesterase (AChE).

Results: All four markers were detected in neurons of the PG at E18. Changes in the appearance of these markers from E18 to P36 reflected previously described growth changes in the PG. Axons containing AChE, TH, NPY, or VIP were first detected within the cervix at E20. Immunopositive axons first appeared as thick, unbranched structures at the outermost portion of the cervical myometrium. Over time, these axon bundles ramified to form discrete varicose axons. The ingrowth was similar for axons containing each of the four markers.

Conclusions: The relative density of each neuronal type in the PG was reflected in the density of axons containing the same marker in the cervix. Changes in neurotransmitter/neuropeptide staining of PG neurons or axons in the cervix were not observed as the animals approached puberty. © 1994 Wiley‐Liss, Inc.
Precursors of macrophages in embryonic rat lungs fail to exhibit granulocyte‐forming potential
Authors: Sorokin Sergei P. , McNelly Nancy A. , Hoyt Richard F. , Svoboda Kathy K. H.
Published: February 2005

Background: Mesenchyme‐like macrophage (M) precursors called angular cells are present in rat lungs on the thirteenth day of gestation and by then can differentiate into outright macrophages. Based on studies of bone marrow–derived cells, it is widely believed that the macrophage line necessarily proceeds from a colony‐forming unit with dual granulocyte‐macrophages potential (CFU‐GM). In embryos this seems doubtful since macrophages are already scattered throughout the body before the first granulocytes appear. We examined the question in organ cultured 14 day prenatal rat lungs after having shown earlier that the macrophage population developed in explants is increased by exposure to M‐ and GM‐colony‐stimulating factors (CSFs) but is unaffected by multi (IL‐3)‐ or granulocyte (G)‐CSF. Reportedly retinoic acid (RA) shifts CFU‐GM strongly to wards granulocytic differentiation and inhibits mitosis of unipotential macrophage precursors but not differentiated cells. Transforming growth factor β1 (TGF) inhibits multipotential blood progenitors but allows proliferation of committed precursors, and TGF together with GM‐CSF induces granulocytopoiesis from CFU‐GM.

Methods: Lung pairs were grown on a serum‐containing medium or one supplemented either by RA, TGF, or TGF/GM‐CSF to form a control and three experimental groups. A fourth experiment compared responses to M‐CSF exposure and M‐CSF/TGF. Macrophage population growth was estimated by measuring the areas of coronas formed by macrophages emerged from the explants. F‐actin was stained with florescein‐labeled phalloidin.

Results: In all experiments macrophages were produced unmixed with granulocytes. By +8 days they had largely emerged to form coronas about the lungs. In cultures exposed to RA, macrophages were less intensely stained for actin and slower to emerge than controls. At +8 days, however, coronal areas were not significantly different from controls, as was also true for the TGF group. In contrast, coronal areas of cultures grown with TGF/GM‐CSF were much larger. At +17 days, mean coronal area of TGF cultures was about half that of controls (P < 0.05), whereas mean coronal area of the TGF/GM‐CSF group was 5.4 times greater (P < 0.001). Macrophages from control and TGF‐exposed cultures responded to M‐CSF by an increase in coronal area which was greater among cultures given M‐CSF alone than those given TGF + M‐CSF (both P < 0.005).

Conclusions: Macrophage precursors in embryonic lungs are distinct from CFU‐GM. © 1994 Wiley‐Liss, Inc.
Exogenous cytokines enhance survival of macrophages from organ cultured embryonic rat tissues
Authors: Sorokin Sergei P. , McNelly Nancy A. , Hoyt Richard F.
Published: February 2005

Background: Macrophage precursors are present in embryonic rats shortly after the onset of hematopoiesis. During organogenesis they soon establish residency in many parts of the body and become convertible into phagocytes, at first gaining morphological characteristics of macrophages and later a range of surface antigens used to characterize subpopulations in adults. Nonetheless, it is uncertain whether representatives of this fetal lineage continue to exist past birth. We investigated the question indirectly by seeing if such cells can be made to survive in vitro to an age equivalent to adulthood and by examining underlying conditions that favor this outcome.

Methods: Fourteen‐day embryonic lungs, hearts, and limb buds were organ cultured on a firm serum‐containing medium. Fetal macrophages developed within all explants and then migrated out to form a corona of cells surrounding each explant. The lung cultures were selected for subsequent work which mainly used coronal area as the measure of macrophage population size in experimental and control groups. Baseline growth and survival of macrophages were established for cultures grown on standard medium, then effects of the following were examined: indomethacin (10−6M) as it influences initial production of macrophages from precursors and later survival of differentiated cells; and macrophage colony‐stimulating factor (M‐CSF), used alone at moderate dosage (50–100 U), and combined with granulocyte‐macrophage CSF (both 200 U), for its importance to long‐term survival of the population. Mitogenic influence of M‐CSF on differentiated macrophages was demonstrated by uptake of 5‐bromo‐2′‐deoxyuridine.

Results: Indomethacin inhibited the formation of macrophages from precursors but enhanced the survival of differentiated cells. M‐CSF increased BrdU uptake of differentiated macrophages and permitted coronal growth to continue long past the ∼30 day limit of controls. Beyond this interval, M‐CSF was essential for macrophage survival, since coronas quickly shrank after the cytokine was withdrawn. Administration of the M‐CSF/GM‐CSF mixture to the 2 oldest M‐CSF‐exposed cultures between 98 and 127 days in vitro resulted in an increase in the number of coronal macrophages (P < 0.001); withdrawal between 129 and 140 days led to a decrease (P < 0.005). Ultimately a few cells were still surviving at 183 days.

Conclusions: Intrinsic factors promote early formation of macrophages within the explants, but the availability of factors is lessened by the anti‐inflammatory action of indomethacin. Its later promotion of macrophage survival may be based on suppression of autogenous prostaglandin (PGE2) synthesis. M‐CSF greatly promotes macrophage survival; in context this is sufficient to show that the fetal macrophage line has a clear potential to survive well into adulthood. © 1994 Wiley‐Liss, Inc.
Morphological and kinematic study of the tongue and buccal cavity in the lizard Anguis fragilis (Reptilia: Anguidae)
Authors: Toubeau Gerard , Cotman Christophe , Bels Vincent
Published: February 2005

Background. The ability to detect chemical cues is highly developed in Scleroglossa, and particularly in anguid lizards. This ability was predicted because anguids possess a well‐developed vomeronasal organ (VNO) (or Jacobson's organ) and rely largely on chemical cues in various behaviours as other active foragers. In this work, we have investigated the possible functional association between tongue flicking and the VNO in the lizard Anguis fragilis.

Methods. The morphology of the tongue and the buccal cavity was investigated by light and scanning electron microscopy. The kinematics of tongue and jaw movements was studied by high speed cinematography.

Results. The epithelial cells of the ventral aspect of the tongue tips show microstructures (microridges, microfacets, micropores) which are not present on other areas of the mouth. Beneath the tongue, the floor of the buccal cavity shows two concave‐like elevations suggesting a structural analogy with the anterior processes described in snakes. The apex and the internal margin of these processes bear parallel oblique ridges. Taste buds occur anteriorly on the buccal floor and on the palate and are abundant on the internal side and on the edge on the anterior processes. The tongue showed three modes of tongue flicking: simple downward extension, single oscillation, and multiple oscillations. At each tongue flick, the ventral surface of the tips was observed contacting the substratum. Immediately after the tongue retraction, the buccal floor moved slightly upward. The observation of tongue flicking with the mouth open showed that the anterior processes moved upward when the tongue was retracted.

Conclusions. These observations suggest the following: (1) during tongue flicking the ventral surface of the tongue tips invariably makes contact with the substratum; (2) the microstructures of the tongue tips and the ridges of the anterior processes might be helpful for collecting and receiving, respectively, chemicals during tongue flicking; (3) the anterior processes may be apposed on the roof of the mouth next to the ducts of VNOs when the buccal floor is fully elevated; (4) due to their localization, the taste buds could be equally stimulated by the molecules transferred during tongue flicking. © 1994 Wiley‐Liss, Inc.
Differentiation of periodontal ligament fibroblasts into osteoblasts during socket healing after tooth extraction in the rat
Authors: Lin Wen‐Lang , McCulloch Christopher A. G. , Cho Moon‐Il
Published: February 2005

Background: The entire socket after tooth extraction is filled with new bone formed by osteoblasts (Obs), but the origin of these Obs remains unknown. Thus, the proliferation and migration of paravascular and endosteal fibroblastic cells and periodontal ligament (PDL) fibroblasts (Fbs) and their differentiation into Obs during socket healing after extraction of the first maxillary molars of the rat were investigated.

Methods: The proliferative activity and migration of these cells in the sockets after tooth extraction were studied using radioautography and immunohistochemistry after injection of 3H‐thymidine and 5‐bromo‐2′‐deoxy‐uridine (BrdU), respectively. Their morphological changes during differentiation was investigated by transmission electron microscopy.

Results: One day after tooth extraction, PDL Fbs were the major cell type in the PDL remnant of the socket. Proliferation was low (labeling index (LI) = approximately 2%) until 16 h after tooth extraction but dramatically increased to a maximum level 1 day postextraction (LI = 23%). Between 1 and 2 days, numerous PDL Fbs in the PDL remnant actively migrated into the coagulum and continued to proliferate. On the basis of the high proliferative activity and small number of cellular organelles responsible for procollagen synthesis, these cells appear immature. At 3 days, Fbs contained more cellular organelles and deposited more collagen fibers as they replaced the coagulum with dense connective tissue and the LI declined. At 4 and 5 days, some of the Fbs began to differentiate into Obs, and the proliferation of Fbs dramatically decreased to baseline values. The migration of PDL Fbs and their differentiation into Obs were investigated by labeling with 3H‐thymidine or BrdU 1 day after tooth extraction. Heavily labeled Fbs were observed in the PDL remnant at 1 day, in the coagulum at 2 days, and in the dense connective tissue at 3 days. Labeled Obs associated with new bone were seen 4 days after injection. Endosteal and paravascular Fbs also proliferated, but at a lower level and at later time periods than the PDL Fbs. Surprisingly, endosteal and paravascular Fbs contributed only a small population of Fbs to socket healing.

Conclusions: These results indicate that PDL Fbs after tooth extraction actively proliferate, migrate into the coagulum, form dense connective tissue, and differentiate into Obs which form new bone during socket healing. © 1994 Wiley‐Liss, Inc.