Microplicae-like structures of the fallopian tube in postmenopausal women as shown by electron microscopy.

Female reproductive aging is associated with several morphological changes of the genital tract with a subsequent decline in fertility; however, ultrastructural changes occurring after menopause have still not been well illustrated. Our aim was to characterize the three-dimensional microanatomy of the luminal surface of the human fallopian tube in perimenopause and postmenopause. Twenty bioptic samples of fallopian tubes were obtained after surgery under the informed consent of the patients. Samples were processed for transmission electron microscopy (TEM) and field-emission scanning electron microscopy (FE-SEM). As age increases the surface epithelium of the fallopian tube appeared somewhat flattened. Correlated TEM/FE-SEM observations showed gradual shortening of microvilli and deciliation. The most interesting finding was the gradual formation of microplicae-like structures on the surface epithelium, particularly from late perimenopause to postmenopause. Microplicae-like structures, associated with other regressive changes, represent an important adaptation of the epithelium of the fallopian tube; these are likely induced by the physiological process of aging, thus better withstanding hormonal changes associated with the advent of the menopause.

Pietro Motta's latest studies on the microanatomy of menopause: revised concepts on the beauty of aging.

Menopause signs a hallmark in women's life. When compared to traditional two-dimensional techniques, scanning electron microscopy (SEM) allows to discover the impressive microcosm of the human body and offers original views of the real three-dimensional ultrastructure of reproduction. On the basis of Prof. Motta's last and original book, herein we show a selection of microscopic images that characterize the 3D changes taking place on the surface epithelia of the aging woman's reproductive tract. Biopsies of ovaries, tubes, uteruses, cervices and vaginas were obtained from women (45-72 years old) during surgical or endoscopical procedures and after the informed consent of the patients. Samples were processed for SEM as reported elsewhere. Reproductive aging is associated to epithelial flatness, higher stromal density, absence of ovarian follicles, thickening of vascular walls and lack of glandular secretion. The uterus and the tube show a morphodynamic sequence of gradual microvilli shortening, patchy to complete deciliation and formation of microplicae like structures. The formation of microplicae like structures is interpreted as an adaptive mechanical response of the genital epithelia to the new microenvironment. We can propose that these structures may represent the initial stage of a physiologic metaplasia. In conclusion, imaging of menopause through the use of SEM allows a better understanding of the morphological and physiopathological bases of female aging and represents a perfect blend of art and aesthetics: a further confirmation of the endless beauty of our inner microscopic anatomy.

Ultrastructural dynamic features of in vitro fertilization in humans.

The present study on in vitro fertilization in humans demonstrates that three-dimensional (3-D) fine morphology by high resolution scanning electron microscopy (SEM) combined with parallel light and transmission electron microscopy (TEM) can reveal a number of new cellular detailed findings which cannot be detected with other methods. In this study the following aspects have been investigated in early human embryos. 1. Micro-topographical features of the zona pellucida (ZP), surface blastomeres and polar body. 2. Intracytoplasmic features of mature and healthy oocyte, in vitro fertilized (IVF) oocyte and early embryo development. 3. Comparison of general views of intracytoplasmic sperm injection (ICSI) and conventional IVF (C-IVF) of early embryos. 4. Presence of unusual large tubular smooth endoplasmic reticulum (SER) aggregates in 4, 5, and 6-cell embryos after ICSI. 5. Inside views of 3-D blastocysts such as inner cell mass and trophoblast. To our knowledge, this is the first time that such images are reported by using these techniques.

Undergraduate medical education: tendencies and requirements in a rapidly developing Europe.

This study pinpoints the necessity to constantly monitor local approaches in undergraduate medical education on an inter-European scale. Traditional undergraduate medical curricula need restructuring to account for the increasing amount of medical knowledge and rapid changes and developments in societies, nosology, therapy and IT. European undergraduate medical curricula should be harmonized not egalized, with a focus on inter-European sharing of resources, mobility, credit (allocation, accumulation and transfer), definition of European and trans-European mission statements, identification of quality metrics, advice on dealing with conflicting aims such as specialization and generalization, on communicating core knowledge instead of providing overabundance of information, and on introducing multifaceted teaching and learning methods, as well as providing strategies for life long learning. Sound medical education can no longer and nowhere be considered under the autonomous auspices of individual Medical Schools or national philosophies. It has to be perceived and structured as a competitive and flexible approach which promotes life long learning of teachers, students, physicians and other related staff with international awareness. It is stressed that student and staff mobility, as well as virtual mobility in the form of worldwide available teaching modules and expertise have to be incorporated into national medical curricula. This is to guarantee up-to-date education in support of patient demands, future professionality and competitiveness of students, physicians and Public Health System institutions. The formal approaches of traditional subject related curricula as well as problem based learning must be linked with quality approved state of the art ODL, evaluated international CME strategies and training in the utilization of IT in preparation of lifelong learning. Strategies for the use of IT need updating on a regular basis to diminish the gap between undergraduate and postgraduate medical education. General European perspectives of medical education are discussed in relation to ECTS, ODL, compulsory credited and evaluated CME and relicensing of physicians. Prime features of ETM--the most reputed and well-known European medical CME initiative fostering quality assured international awareness are described and recommended for local and nationwide implementation. Specific links of the Bonn undergraduate medical curriculum with credited and evaluated CME and imminent European strategies are detailed. The authors conclude that European universities not adapting at least some of the outlined curricular necessities will rapidly lose their competitiveness compared to other national and international Medical Schools. Harmonized European ethical mission statements and consequent utilization of IT deserve special considerations in this context.

A new concept of the pattern of structural changes with bone loss by histomorphometric analysis using bone slabs.

We examined naked bone slabs (1.2 mm thick) from iliac bone biopsied cores obtained from 33 women aged 33-89 years. The number, size, and shape of the pores in the bone slabs were analyzed. The results revealed that the % bone area (the percentage area occupied by bone in the slab) was linearly correlated with age and other parameters, such as the size of pores, irregularity of pores, and pore distance, but was not correlated to the number of pores. We found a second-degree polynomial relationship between the % bone area and the number of pores. Based on three parameters--% bone area, number of pores, and size of pores--cluster analysis was performed and the specimens divided into three groups. The group with sufficient bone mass showed few small round pores, and the group with severe bone loss revealed a few large pores that were caved in. The characteristics of these groups represented the relationship between bone mass and structural change. The remaining group with moderate bone loss was divided into two subgroups, one with an increased number of pores without expansion and one with expanded pores without an increase in number. We presumed that the variations between the groups were caused by differences between fine and rough structures in the trabeculae caused during the process of bone loss. We concluded that this analysis of bone slabs allowed the pattern of trabecular structural change that occurred with bone loss to be determined easily and visually.

Microanatomy of the female reproductive organs in postmenopause by scanning electron microscopy.

The detailed three-dimensional ultrastructural features of the reproductive organs of menopausal and postmenopausal women were studied by means of integrated transmission and scanning electron microscopy (SEM) and reported in a new colored microtopographical fashion. These methods revealed significant alterations in the microanatomy of the various reproductive organs specifically related to the decline of plasma estrogen levels. In particular, the ovary progressively showed characteristic wide areas of loss of epithelium with consequent exposure of the underlying connective tissue. Both endometrial and tubal mucosa demonstrated a gradual but often dramatic decrease in the number of ciliated cells which was more evident in the tube. In addition, the non-ciliated (microvillous secretory) cells of the uterus, including both endocervix and tubal mucosa, became flattened and, in some instances, their apical poles developed unusual wrinkles (microridges or microplicae). The ectocervix and vaginal squamous cells presented a reduction in the number of their microridges and changes in the typical structural organization. These microtopographical results showed that the decline of estrogen during the menopause and postmenopause induces important and complex structural changes of the woman's reproductive system, much more detailed than those revealed to date by the use of only conventional optical and transmission electron microscopy (TEM). The three-dimensional findings offer the opportunity to re-evaluate the classic histopathology of the above aging organs using more refined microtopographical and morphophysiopathological parameters.

Scanning and transmission electron-microscopic study of the development of the podocyte in the human fetus.

The metanephric kidneys of seven human fetuses at 11-17 weeks' gestation were examined by scanning and transmission electron microscopy in order to evaluate differentiation of glomerular podocytes. When glomeruli were in the stage of S-shaped bodies, the surface of the visceral epithelium of renal corpuscles was smooth, with indistinct cell borders. As the glomeruli developed, visceral epithelial cells of renal corpuscles became spherical and resembled clusters of grapes in dense aggregation. In this stage, processes and foot processes were simultaneously formed at the base of epithelial cells. As glomeruli further differentiated, visceral epithelial cells of renal corpuscles began to separate from one another and became flat with the development of vascular loops. Processes and foot processes were exposed for the first time in Bowman's space. In this stage, the degree of differentiation of epithelial cells varied widely among various sites of the glomerulus. As glomeruli developed further, projections became more complex and epithelial cells began to show structures similar to those of adult epithelial cells. The adjacent foot processes arose from different cells throughout the period of morphological differentiation.

Ultrastructure of human Leydig cells at early gonadal embryogenesis.

The ultrastructure of human Leydig cells at different stages of the testicular prenatal development is described by means of transmission and scanning electron microscopy. Between 5 and 7 weeks of gestation (w.g.) the interstitial tissue of the gonad is filled with small undifferentiated mesenchymal cells, migrating primordial germ cells and blood vessels. When the embryo is 7 to 8 weeks-old Leydig cells (LC) appear in basically two morphological patterns, light and dark cells. Their most significative feature is the development of the smooth endoplasmic reticulum (SER) as a dense tubulo-vesicular network and the presence of numerous pleomorphic mitochondria with mainly lamellar cristae. At 14 and 16 w.g. the testicular interstitium reaches the maximum development; the cytoplasm of the LC shows a widespread network of anastomosing tubules of the SER and mitochondria with tubular cristae. Fetal LC show a partial cell coat, lack the crystals of Reinke, have few lipid droplets and show no signs of massive cell degeneration, at least until 16 w.g. These ultrastructural modifications in fetal LC are in accordance with the changes in both steroidogenic activity and hCG levels reported by the literature to occur at this stage of development. Junctional complexes were often observed among LC from 7 to 8 w.g. onwards.

Oocyte follicle cells association during development of human ovarian follicle. A study by high resolution scanning and transmission electron microscopy.

Morphodynamics of oocyte follicle cells association during the development of human ovarian follicles were studied by transmission electron microscopy and high resolution scanning electron microscopy including the ODO method. For this study primordial, primary, growing preantral and antral follicles were systematically analysed in a total of 20 adult and fetal (3-8 months and at term) ovaries. In early stages of follicle development (primordial and primary stages) the flattened and/or polyhedral cells, closely associated with the growing oocyte, project an increasing number of microvillous processes. These are in apposition with the oolemma, and form bulbous terminals presenting attachment zones such as zonula adherens, desmosomes and communicating junctions (gap junctions). "Focal contacts" between oolemma, and lateral microvillous extensions of follicle cells were also present. Unusual forms of contact between follicle cell microvilli and oocytes in the early stages of growing primordial and primary follicles were also observed. These consist of long, thin extensions penetrating into the oocyte through deep invaginations of the oolemma. The aid of high resolution SEM of specimens subjected to the ODO method clearly reveals their 3-D arrangement within the ooplasm. They appear as long tortuous microvilli coming very close to the nucleus, and in their course are closely associated with a variety of organelles such as Golgi vesicles, endoplasmic reticulum membranes and nascent forms of smooth endoplasmic reticulum. Using integrated observations by TEM and SEM, there may be as many as 3-5 "intraooplasmic processes" even in only one plane of fracture of an oocyte. Therefore, if the total volume of the oocyte and associated cells is considered, their amounts appear to be higher than previously reported. Thus, they have to be considered as normal devices of deep contact between the ooplasm and associated follicle cell extensions. The presence of such structures within the ooplasm in early developing follicles well coincides with the great increase in volume of the oocyte. Although it is commonly believed that the activation of the growing oocyte may depend on the numerous contacts between the oolemma and follicle cells (mostly via gap junctions), the finding of these additional intraoocytic extensions suggests that they may in someway contribute to the initiation of growth in the human. In fact, these microvilli penetrate deep into the ooplasm, much like a sword in its sheath.(ABSTRACT TRUNCATED AT 400 WORDS)

Structural changes of iliac cancellous bone in postmenopausal women: a scanning electron microscopic study.

The functional state of iliac cancellous bones in healthy postmenopausal women was investigated by scanning electron microscopy (SEM) using a modified organic preparation method. SEM analysis of the location, number, size and phase of the remodeling sites showed that normal iliac cancellous bone of postmenopausal women has high resorbing activity in the early stage of postmenopause in both the region near the cortico-endosteum and the midway region, while in the late stage of postmenopause there is a great difference in resorbing activity between the two regions; namely, the resorbing activity progressively decreases with age, but high resorbing activity is continuously present in the region near the cortico-endosteum. Our results suggest the possibility that at the region near the cortico-endosteum the bone volume loss occurs continuously throughout all the stages of post-menopause, while at the midway region it occurs only in the early stage and not in the late stage of postmenopause.

The spatial distribution of spindle microtubules in anaphase 3Y1 cells.

The spatial distribution of the microtubules (MT) in the rat 3Y1 cells in mitosis was investigated by immunoelectron microscopy and computer-graphic reconstruction of serial thin sections. In anaphase the interzone-MT increased in number gradually with advancing phase, while the kinetochore-MT in half-spindles decreased. The interzone-MT overlapped with each other at the equatorial region of the cell, and they formed a specific structure called the 'stem bodies'. The ends of the interzone-MT opposite to the stem bodies often attached to chromosomes but not to the poles. The stem bodies were not labeled with immunogold particles of anti-alpha tubulin. Some of the stem bodies or MT which originate from stem bodies were found just beneath the plasma membrane in the equatorial region where abundant actin filaments appear showing the formation of the contractile ring and subsequently the cleavage furrow begins. On the basis of these observations it is assumed that the interzone-MT is involved both in the separation of chromosomes in anaphase and in the formation of the cleavage furrow in telophase.

Olfactory epithelium in young adult and aging rats as seen with high-resolution scanning electron microscopy.

The present study uses mainly scanning electron microscopy to demonstrate the three-dimensional internal cell structures of rat olfactory epithelial cells. The aldehyde-prefixed osmium-DMSO-osmium (AODO) method devised by Tanaka and Mitsushima (1984) was applied to the present study to disclose intracellular structures such as endoplasmic reticulum, mitochondria, Golgi apparatus, and lysosomes. The spatial distribution pattern of these structures in olfactory and supporting cells is discussed, paying special attention to the formation of lipofuscin-like granules present in aged rats.

A new approach to the study of ovarian follicles by scanning electron microscopy and ODO maceration.

The ultrastructure of the follicle-oocyte complex in rodents and humans was revealed by high resolution scanning electron microscopy (SEM) following the Osmium-DMSO-Osmium maceration method (TANAKA and NAGURO, 1981). In primary follicles, the majority of oocyte organelles such as mitochondria and Golgi complex components are concentrated in a juxtanuclear area. In particular, many spherical mitochondria are oriented all around the nucleus. After maceration of the ooplasm matrix, most of these mitochondria appear intermingled with numerous microtubules (MT) and associated with many Golgi vesicles. Such a nuclear polarization of organelles, essential to the oocyte metabolism, might depend upon a MT activity. MT might guide mitochondria to gather in the perinuclear region and further maintain their close associated to the nuclear envelope. A similar relationship among microtubules, vesicular Golgi complex and mitochondria has been also observed when, in maturing oocytes, these organelles migrate and gather in other areas of the ooplasm. A pattern common only to human developing follicles appears in the occurrence of long microvilli projected from follicle cells deep into the oocyte. These unusual microvilli running within the ooplasm are surrounded by several vesicles of the Golgi complex and endoplasmic reticulum, and often end close to the nucleus. In the antral follicle, the microvilli of corona cells, directed toward the oocyte (after their full exposure through the chemical dissolution of the zona pellucida matrix) are extremely numerous (up to 70/cell), long (up to 7/10 microns) and tortuous. They resemble epididymal stereocilia, may be ramified and possess bulbous tips. In contrast, oocyte microvilli are thin and short.(ABSTRACT TRUNCATED AT 250 WORDS)

Association of cytoskeletons with the Golgi apparatus: three-dimensional observation and computer-graphic reconstruction.

The association of cytoskeletons with the Golgi apparatus (GA) in cultured 3Y1 cells was investigated by stereo electron microscopy of thick sections and computer-graphic reconstruction of serial thin sections. The 3-dimensional analysis has demonstrated that: 1) both microtubules (MT) and vimentin intermediate filaments (IF) were abundantly present in close vicinity to GA, and some of them were closely associated with GA; and 2) such GA-associated cytoskeletons were attached to GA either at their termini or at their lateral side. The present observations suggest that both MT and vimentin IF are responsible for maintaining the structural integrity of GA.

The tannin-osmium conductive staining after dehydration: an attempt to observe the chromosome structure by SEM without metal coating.

The tannin-osmium conductive staining method was modified in order to observe chromosomal structures without metal coating. The treatment with tannic acid and OsO4, which has been used in aqueous solution in the original method, was performed in acetone solution after dehydration in the present study. The usefulness of this method is discussed showing ultrastructural images of chromosomes of Drosophila and Tradescantia, which can be achieved by the method.

Freeze-fracture study of the plasma membranes of the septal olfactory organ of Masera.

The olfactory border and the apical cell contacts of the organ of Masera (MO) of the mouse were investigated by freeze-fracture electron microscopy. The olfactory border is mainly composed of the terminals of receptor and supporting cells. Cells with thick microvillus-like projections, though less frequent than the other two cell types, also contribute to the border. Olfactory knobs show transitions between those displaying numerous cilia and those characterized by few or no cilia. The olfactory cilia have a typical necklace of 6-9 rows of particles. The eruption of developing cilia seems to be preceded by the formation of circular arrays of particles. The density of intramembranous particles (IMP) per micron2 in P- and E-faces of the ciliary membranes is 1095 +/- 190 and 205 +/- 65, respectively. In the microvilli of supporting cells, the density of IMP per micron2 is 1800 +/- 270 for the P-face and 570 +/- 135 for the E-face. At the base of the supporting cell microvilli, rod-shaped particles are observed. The lateral plasma membranes of these cells bear orthogonal arrays of particles. In the apical region of the MO neuroepithelium, extensive zonulae occludentes are present which seal the intercellular cleft. The zonulae occludentes between supporting and receptor cells are composed of 5-13 junctional strands, usually arranged in an elongate network. Zonulae occludentes between supporting cells are, in addition to the elongate network, also arranged in a mesh-like pattern. Gap junctions, both associated with the zonulae occludentes and independent of them, are occasionally found between supporting cells. The results obtained indicate that important similarities exist between the neuroepithelium of the MO and the olfactory epithelium proper, whereas remarkable differences exist between the MO and the vomeronasal neuroepithelium.

Effect of N-methyl-formimino-methylester on the vomeronasal neuroepithelium of mice.

N-methyl-formimino-methylester (MFM), a highly volatile chemical substance, causes massive, transient sensory-cell degeneration in the main, but not in the vomeronasal olfactory sensory epithelium of mice. After MFM-treatment it appears possible to study the accessory olfactory system after chemical "deafferentation" of the main system.

The vomeronasal epithelia of NMRI mouse. A scanning electron-microscopic study.

The features of the apical and lateral surfaces of cells of the vomeronasal epithelium were studied in adult male mice by scanning electron microscopy. Supporting cells and receptor cells of the neuroepithelium are covered with microvilli. Microvilli of the sensory cells are longer and thinner than those of the supporting cells. Additionally, the former differ in local distribution, orientation, occurrence of branching and appearance of the cell coat. The receptor-free epithelium consists most likely of one cell type only, which shows different structural modifications including the presence, number and length of microvilli and cilia. In the transitional region, between the neuroepithelium and the receptor-free epithelium, immature receptor cells are present.