Anatomical Record最新文献

Background: The element lanthanum (La) can be used as a tracer for verification of membrane permeability. The aim of this study was to establish whether 1) distribution of La in the myocardium of rat hearts depends on the degree of ischemic stress and 2) morphometrically determined cell and mitochondrial swelling correlates with the La distribution.

Materials and methods: Isolated beating rat hearts were arrested by coronary perfusion with the cardioplegic solution Custodiol (controls) or by aortic cross clamping followed by exposure to different degrees of ischemic stress. The solutions for perfusion-and postfixation as well as for rinsing contained 1.1% La(NO3)3. Cellular and mitochondrial swelling were determined morphometrically and myocytes exhibiting intracellular La were quantified and stated as percentage of test fields.

Results: Immediately after cardiac arrest La was present as precipitates only in a few myocytes adjacent to the outer mitochondrial membrane as seen by cTEM and ESI. In such cells La was also detected by EELS in mitochondrial matrix and myofibrils. Advanced ischemic stress led to an increase of the percentage of myocytes containing detectable intracellular La. After 45 min ischemia at 30 degrees C, myocytes and mitochondria showed a remarkable edema and different intracellular distribution patterns of La. After 90 min of ischemia at 20 degrees C interruptions of sarcolemma could only be detected in a few of the swollen myocytes. Roundish La granules were seen in the myofibrils. The percentage of myocytes containing intracellular La and the extent of cellular and mitochondrial swelling showed a significant correlation.

Conclusions: Patterns of intracellular La distribution depend on the degree of ischemic stress and correspond to the degree of cellular as well as mitochondrial edema. These results point at a direct relation between alterations of membrane permeability and development of edema.

Background: This report is an extension of previous observations (Maleszewski 1992. Mol. Reprod. Dev., 33:215-221) on the behavior of mouse sperm nuclei incorporated into parthenogenetically activated mouse oocytes prior to the first cleavage division and undergoing transformation during mitosis.

Method: Artificially activated mouse oocytes were inseminated in vitro and an ultrastructural analysis was performed of sperm-derived nuclei present in two parthenogenetic two-cell embryos.

Results: Both chromatin and nuclear envelope of sperm derived-nuclei are structurally identical with those of oocyte-derived nuclei and of the nuclei of blastomeres of normal two-cell embryos.

Conclusions: Cytoplasm of the parthenogenote during the first mitotic division has the ability to transform sperm nucleus into a male pronucleus just like the cytoplasm of a metaphase II oocyte.

Background: A method is described in which formaldehyde levels are greatly reduced in our gross anatomy laboratory in order to comply with increasingly severe safety and health regulations.

Methods: A novel type of dissection "bed" has been introduced which incorporates an internal motor that causes a downflow of formaldehyde-rich vapors, which are absorbed by a replaceable active carbon filtration system.

Results: Use of the new dissection "beds" has resulted in the recirculated air being virtually formaldehyde-free. Formaldehyde vapor levels in our gross anatomy laboratory have been greatly reduced and are typically in the range of 0.03-0.09 ppm.

Conclusions: The new system allows us to comply with safety and health regulations and provide a dissection room with an excellent working environment.

Background: Previous work using unfixed or fixed tissues has shown that casts can be made that demonstrate the three-dimensional structure of tissues such as the bronchoalveolar tree or the vasculature. In this report, a new method for creating a vascular-bronchoalveolar cast is described.

Method: Canine lungs were taken from storage in formalin. Silastic 734 RTV (room temperature vulcanizing) with added red or blue pigments was injected into the pulmonary arteries and veins, respectively, using compressed air. This was followed by filling the airway with clear (translucent) Silastic 734 RTV. The lung tissue was then corroded with potassium hydroxide.

Results: Vascular-bronchoalveolar casts were recovered giving fine detail as shown using stereo light microscopy or scanning electron microscopy.

Conclusions: This method may be useful for not only microvascular anatomy studies of lungs, but also for studying the microvasculature of other normal and diseased tissues.

Background: It is not well known how the immediate precursors of osteoclast develop into osteoclasts in the fetus. This ultrastructural-cytochemical study was designed to clarify the formation process of the osteoclasts and their increased activities in the fetal mouse limb buds after administration of high dose parathyroid hormone (PTH).

Methods: Twenty-four or forty-eight hours after the high doses of PTH were injected into amniotic fluid of the pregnant C3H mice, the femoral limb buds of embryos were dissected out. Tartrate-resistant acid phosphatase (TRAP) reactions were performed while preparing specimens for electron microscopy.

Results: Both control and PTH-given preosteoclasts and osteoclasts exhibited TRAP-positivities in dense bodies and vesicles. As effects of PTH, a binucleated preosteoclast of tandem fashion was observed. More osteoclastic hyperactivities were observed in the diaphyseal bone marrow. An osteoclast with a large cytoplasm exhibited two sets of clear zones and ruffled borders. Some osteoclasts demonstrated prominent amoeboid figures, while other osteoclasts developed large cytoplasmic vacuoles, which contained pieces of calcified chondroid bars.

Conclusions: Our results revealed the progression of maturation from young preosteoclasts to osteoclasts. An existence of a peculiar binucleated preosteoclasts suggested one of the processes for multinucleation of the osteoclast. Quite remarkable osteoclastic hyperactivities were obviously the effects of high dose PTH. Our results also indicated the endophagocytic ability of the osteoclast. How PTH affected the osteoclasts and their precursors in the diaphyseal bone marrow can be speculated.

Background: This study compares the morphology and cytology of olfactory organs in moray eels (Muraenidae), particularly Siderea grisea and some species of the genera Echidna, Gymnothorax, and Lycodontis, fishes that are top predators in shallow-water marine habitats. Some of the species search visually for food while others search by olfaction.

Methods: The morays were collected in the Red Sea; the nasal olfactory organs were dissected and fixed in Bouin's solution for light-microscopy, and 3.5% glutaraldehyde for electron-microscopy studies.

Results: In each studied species the olfactory rosettes are elongated structures situated in closed olfactory chambers between anterior tubular inlet nares and slit-form posterior outlet openings. The double row of lamellae constituting these rosettes are round in Siderea and Echidna and elongated in the other species. They are attached at their base to a median raphe and range in number from 20 in the youngest observed Siderea to 168 in Gymnothorax of 1,500 mm total length. As in other teleosts, the lamellae are covered by a ciliated epithelium composed of three types of sensory cells: two of these, ciliated sensory neurons and ciliated supporting cells, differ in detail, length, and thickness of their cilia and intracellular rootlet system; the third type of sensory cells bears microvillae as well as cilia. Proximal, axonal extensions of the ciliated cells cross the basal lamina in bundles and combine to form fila olfactoria from which the two olfactory nerves extend towards the olfactory bulbs. Lateral extensions at the basal parts of these ciliated cells, the so-called spines, cross the membranes of neighboring cells as dendrites, possibly changing part of all of the ciliated epithelium into an olfactory field. The density and number of sensory cells on the lamellae, as well as observed differences in their foraging behavior in nature and captivity, enable the morays to be divided into two groups: one group, in which the lamellae are richly covered with stereocilia, includes species of the genera Siderea and Echidna, that search for food by olfaction, and the second group, which has a great deal less cells with stereocilia and includes the studies species of Gymnothorax and Lycodontis, locates its food visually.

Background: The aim of the present study was to describe the morphological changes in the normal pattern of ventricular myoarchitecture in the prenatal and adult human heart, to understand the three-dimensional organization of the muscle fibers and their active functional role in valvular dynamics.

Methods: We used dissection and histological techniques in 56 human hearts from fetuses and adults of both sexes.

Results: In all hearts, the ventricular wall was arranged in three different layers: superficial (subepicardial), middle, and deep (subendocardial) myocardium. The superficial and deep layers are present in both ventricles, whereas the middle layer is found only in the left ventricle. Age-related differences were noted in the pattern of myoarchitecture of the superficial layer, mainly in the fetal period, and especially in the right ventricle; however, the middle layer always shows a circumferential pattern, which is specially evident in elderly hearts. The ventricular fibers in the superficial and deep layers are anchored in the ventricular orifices.

Conclusions: Our findings reveal that muscle fiber architecture showed age- but not sex-related differences. These variations may reflect a mechanism of adaptation of the heart to functional demands throughout life.

Background: The purpose of this work was to describe the ultrastructure and cytochemical staining characteristics of canine peripheral blood lymphocytes with natural killer (NK) cell activity, with comparison made to non-NK lymphocytes.

Methods: Canine lymphocyte populations evaluated for ultrastructure, cytochemical staining, and NK function (by 51chromium release assay) included: peripheral blood lymphocytes; lymphocytes from band 1 (NK-enriched), band 2, and the pellet of a 45/50% percoll gradient; lymphocytes from the supernatant fluid (non-conjugated lymphocytes) and pellet (lymphocytes conjugated to tumor cell targets) of a 17% percoll gradient; and null (CD4-CD8-) and CD4-CD8+ lymphocytes.

Results: NK activity was concentrated in band 1 lymphocytes of the 45/50% percoll gradient with further enhancement of activity occurring in sorted null cells. Canine NK cells were 5.5 to 6.5 microns in diameter with a reniform (kidney bean shape) nucleus, and electron-dense cytoplasmic granules. NK cells (percoll band 1 cells and null cells) had larger cell and nuclear area, and less round nuclei when compared to non-NK lymphocytes. The overall cytochemical staining (chloracetate esterase, peroxidase, sudan black B, naphthyl acetate esterase, naphthyl butyrate esterase periodic acid-Schiff stain, and acid phosphatase with and without tartrate) pattern was similar in all the lymphocyte populations evaluated.

Conclusions: This work confirms the usefulness of a 45/50% percoll gradient in obtaining a NK-enriched fraction of canine lymphocytes, and shows further enhancement of NK activity in sorted CD4- CD8- cells. The ultrastructure of canine NK cells is similar to that reported for human NK cells, but is different from that of other canine peripheral blood lymphocytes. Standard cytochemical staining does not discriminate canine NK cells from other lymphocytes.

Background: Sexual maturation is a very complex phenomenom that it is mediated by the ontogeny of the hypothalamus-pituitary-gonadal axis during intrauterine life. The maternal pineal gland can affect fetal development because the main pineal hormone, melatonin, crosses the placental barrier. We found that melatonin treatment during gestation in the rat produced delayed sexual maturation of the female offspring. The present work was undertaken to study the maturational stage of oocytes of prepubertal female rats when their mothers were either pinealectomized (PIN-X) or treated with melatonin (MEL) during pregnancy.

Methods: Three groups of female Wistar rats were used: control, PIN-X, and those treated (250 micrograms/100 g body weight) with melatonin throughout pregnancy. Ovaries of 25-30- and 34-day-old female offspring were studied during the prepubertal phase. Morphometric studies of semithin sections (1 micron) of the ovaries were performed. Oocyte, nuclear, and nucleolar volumes were calculated by a computer-assisted program (M.I.P.) in an image analyzer Kontron. Regularity of the structures was determined by the frequency distributions of circular and regular form factors.

Results: Cytometric study of oocyte structure showed a frequency distribution of regular and circular form factors, with a high degree of regularity very close to unit. Cellular and nuclear volumes of follicular oocytes showed a transitory increase at 30 days of age in control rats. In the offspring of MEL-treated mother rats, a pattern of oocyte development showed significantly lower nuclear and nucleolar volumes at 30 days of age than at the other time points and significantly lower cellular volume at 34 days of age than at 25 days of age. In the offspring of PIN-X mother rats, no significant differences in oocyte cellular volumes were observed throughout prepubertal development, but we observed a significantly higher nuclear volume at 25 days of age and a significantly lower nucleolar volume at 30 days of age.

Conclusions: These findings show that the maternal pineal gland participates in cellular and nuclear volumes of prepubertal oocyte development. Melatonin treatment during pregnancy resulted in a redirected postnatal oocyte development.

Background: Pulmonary intravascular macrophages (PIMs) of sheep have a globular surface coat that facilitates endocytosis of tracer particles and Escherichia coli lipopolysaccharide, and is disrupted by the heparin and Brefeldin A treatments. The present study investigated the in vivo dynamics of the coat globules following heparin-mediated removal, and the mechanism of globule organization on the plasma membrane of PIMs in vitro.

Methods: Sheep were administered heparin at a dose of 50 IU/kg body weight IV, and euthanised at 30 min, 3, 6, 12, 48, and 120 hr (n = 2 for each treatment) after the treatment. Control sheep (n = 2) were injected with normal saline solution. The tissues were processed for an ultrastructural examination and acid phosphatase (ACPase) cytochemistry. Heparin-treated lungs were subjected to morphometric analysis of the coat globules. Lung tissues from normal sheep (n = 2) were incubated with phosphatidylinositol-specific-phospholipase C (PIPLC; 2 IU/ml PBS) in vitro for 30 and 75 min.

Results: Heparin study: The ultrastructural and morphometric data showed that the coat globules were removed at 30 min and reconstituted within 48 hr of the treatment. The PIMs showed prominent Golgi complexes associated with secretory vesicles, microtubules, and centriole between 3-12 hr of heparin treatment. Acid phosphatase cytochemistry also demonstrated secretory activity in the Golgi complexes of PIMs during the coat reconstitution. PIPLC study: The coat globules of PIMs were removed in a time-dependent mode by the PIPLC treatment without damage to other cell organelles.

Conclusions: This study demonstrates a time-dependent reconstitution of the coat of PIMs in conjunction with secretory activity following heparin-mediated removal, probably through sequestration of the globules from blood. This ability is of functional significance as the coat mediates particle endocytosis by the PIMs. The results also suggest the presence of a glycosyl-phosphatidylinositol (GPI) anchor in tethering of globules on the plasma membrane of PIMs to offer a structural basis for their integrity in pulmonary vascular flow.