Male Wistar rats were fed diets with different Mg content, ranging from 70 to 850 ppm Mg, for 30 days. After 0, 10, 20 and 30 days, some of the rats were sacrificed for measuring weight, lipid peroxidation, Fe, vitamin E, Na+, K+, Mg2+ and Ca2+ content of testes. After 30 days, the morphology of the testes was investigated by electron microscopy. Mg deficiency induced an increase in weight, Na+, Ca2+ and Fe content and a reduction of K+ and Mg2+ content. Vitamin E content was reduced and the content of malondialdehyde as an indicator of lipid peroxidation was increased. Mg deficiency induced morphological alterations in up to 40% of the spermatids in the 70 ppm Mg group, which consisted: 1) in injured stretching of spermatids; 2) in an irregular arrangement of coarse fibres with missing microtubulus complex (axoneme) and microtubulus sheath; 3) in the development of up to 4 bundles of outer fibrils in one spermatid. The increase of Fe content, lipid peroxidation and the onset of morphological alterations occurred already at a mild degree of Mg deficiency.

Animals↗

PubMedDate not supplied

Iron-induced injury of rat testis.

Male Wistar rats were intraperitoneally injected twice with 0.4 mmol kg-1 FeSO4. One, 2 and 4 days after the second Fe injection, Fe and malondialdehyde (MDA) content in testis was measured, the morphology studied by light and electron microscopy and the number of spermatids counted. After Fe injection, Fe and MDA content had increased in parallel. Light microscopic inspection on days 1 and 2 after Fe injection revealed numerous necroses in the different cell types of the germ epithelium. Four days after Fe injection, fewer alterations were found. Electron microscopic investigations revealed that some spermatids contained up to three nuclei and at least three axonemes. In some sperm tails up to 11 axonemes were found. In some midpieces two or three complexes of axonemes, outer dense fibres and mitochondria were observed. In other midpieces axonemes were absent and replaced by granular and filamentous material. The number of spermatids was reduced 4 days after Fe treatment. The increase in the number of axonemes was similar to that seen in Mg and Zn deficiency, indicating that the increase in Fe content and oxygen free radicals is the major reason for the biochemical and morphological alterations in Mg and Zn deficiency.

Animals↗

PubMedDate not supplied

Pressure controlled preparation of the saphenous vein with papaverine for aortocoronary venous bypass.

BACKGROUND AND METHODS: In 21 patients intraoperatively receiving coronary revascularization, segments of the saphenous vein were prepared for aortocoronary bypass. Postoperatively, the endothelial intima was subjected to electron microscopy. Venous segments in which an intraluminal mean pressure of 263 mmHg +/- 52 mmHg had been measured during preparation were compared with venous segments that had been explanted with the aid of a venous protection bulldog and with pharmacological treatment through papaverine. RESULTS: Those segments of high-pressure distension that had not been protected showed intimal damage with erythrocytes and thrombocytes. On the other hand, venous segments with low-pressure distension that had been protected in the described way during harvesting appeared similar to native veins. CONCLUSION: We conclude that during the preparation of the saphenous vein for aortocoronary bypass surgery, the application of papaverine and the use of the venous protection bulldog clamp is effective in preventing pressure damage during preparation of the vein.

Blood Platelets↗

PubMedDate not supplied

Comparative evaluation of ultrastructural changes in articular cartilage of ofloxacin-treated and magnesium-deficient immature rats.

Ultrastructural changes in immature articular cartilage were studied after treatment of 5-wk-old rats with ofloxacin-a fluoroquinolone-and in magnesium deficiency. Magnesium deficiency was induced by feeding a magnesium-deficient diet for 9 days; the condition was confirmed by measuring the concentrations of the mineral in plasma, bone, and cartilage samples of the animals by atomic absorption spectrophotometry. Oral administration of single doses of 600 or 1,200 mg ofloxacin/kg body weight and magnesium deficiency were sufficient to induce gross structural cartilage defects. Alterations observed on the ultrastructural level showed striking similarities in magnesium-deficient rats and in rats treated with single doses of 600 mg ofloxacin/kg body weight. Typical observations were (a) bundle-shaped, electron-dense aggregates on the surface and in the cytoplasm of chondrocytes, (b) detachment of the cell membrane from the matrix and necrotic chondrocytes, (c) reduction of the extracellular matrix, and (d) swelling of cell organelles such as mitochondria. These findings further substantiate the histological finding that quinolone treatment and a dietarily induced magnesium-deficiency induce indistinguishable pathological conditions in immature joint cartilage, and they suggest that quinolone-induced arthropathy is probably caused by a reduction of functionally available magnesium (ionized Mg2+) in cartilage (42). Furthermore, they provide a basis for aimed studies with human cartilage samples from quinolone-treated patients that might be available postmortally or after hip replacement surgery.

Aging↗

PubMedDate not supplied

Electron microscopic and functional aspects of the human vomeronasal organ.

The vomeronasal organ or Jacobson's organ is essential for pheromone detection and reproductive behavior in most mammals. The purpose of this article is to describe the fine structure of the adult human vomeronasal organ in 14 specimens and to discuss functional aspects. Our studies show a duct-like invagination of the epithelium, surrounded by numerous exocrine glands with short ducts; their fine structure suggests serous secretion. In the depth of the invagination, pseudostratified columnar epithelial cells are seen, with plump processes, kinocilia, and microvilli at the apical cell membrane. There are several cell types that differ regarding their organelles and electron density; the light sensory cells exhibit neurofilaments. Underneath the typical basement membrane, in the very vascular lamina propria, numerous myelinated and unmyelinated axons are present. These morphologic findings, which are unique in the human body, suggest that a chemosensory epithelium corresponding to a vomeronasal organ may exist. Its central connections and the possible functional significance for pheromone detection are unknown. Preservation of the vomeronasal organ in endonasal surgery could become important both clinically and medicolegally, should function be demonstrated in humans.

Adolescent↗

PubMedDate not supplied

Morphological and histochemical effects of 2,3,7,8-tetrachlorodibenzo-p dioxin (TCDD) on marmoset (Callithrix jacchus) testes.

The testes of marmosets (Callithrix jacchus), which had been treated with a single dose of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) (0.3 microgram to 10 micrograms/l kg body weight (BW)) were studied after 7 days using morphological and histochemical techniques. Light microscopic and electron microscopic examination revealed decreased intercellular contact in the germinal epithelium, as indicated first by enlarged intercellular spaces between the Sertoli's cells and between the Sertoli's cells and neighboring germ cells (i.e., spermatogonia and preleptotene spermatocytes), particularly in the basic compartment of the germinal epithelium. Second, decreased intercellular contact was indicated by the accumulation of premature spermatids and spermatocytes in the tubular lumen after TCDD treatment. The Sertoli's cells exhibited an increased amount of lipids, phagolysosomes, and vacuoles in their cytoplasm. Spermatids were frequently affected by TCDD, particularly during early spermiogenesis. These alterations included vacuolization of the cytoplasm and the development of additional germinal vesicles. This special effect on spermiogenesis became even more evident quantitatively by determination and counting of tubular stages in semithin sections. Tubular determination on the basis of the appearance of spermatids revealed that the ratio of tubular stages I to III became lower and that of stages V to VII became higher, dose dependently, indicating a maturation stop at the beginning of spermiogenesis caused by TCDD treatment. After TCDD treatment, Leydig's cells were morphologically unaffected, but histochemical investigations revealed decreased activity of 3 beta-hydroxysteroid dehydrogenase (3 beta-HSD). The sensitivity of the applied methods was different in view of the level of unaffection. The effect of Leydig's cells, as indicated by the decreased activity of 3 beta-HSD, had already been found at a dose of 1 microgram/kg BW TCDD, whereas clear-cut morphological and morphometrical effects were seen at 3 micrograms/kg BW for the first time. Moreover, with the special effect on spermiogenesis in marmoset monkeys, the findings demonstrate that the toxicity of TCDD on testicular morphology is species specific.

3-Hydroxysteroid Dehydrogenases↗

PubMedDate not supplied

Ultrastructure of adult and juvenile marmoset (Callithrix jacchus) Sertoli cells in vivo and in vitro.

The morphologic differentiation of Sertoli cells isolated from adult and juvenile marmosets and cultured on different extracellular matrices was evaluated by light and electron microscopy and compared to cells in vivo. Both cell types could be maintained in culture for at least 6 days. The degree of cellular differentiation, shape, ultrastructural appearance, and polarity seemed to benefit from laminin-coated substrata, compared with collagen-, fibronectin-, serum-, and heparan sulfate-coated substrata. With the former two substrates, a difference in behavior between juvenile and adult cells was evident. Whereas juvenile cells displayed a lesser degree of differentiation, adult cells exhibited identical morphologic characteristics in culture and in vivo. Cyclicity of morphologic features was not found, neither in vivo nor in vitro. The results indicate that: (1) laminin plays a unique role for marmoset Sertoli cell differentiation in vitro compared with other extracellular components; (2) a greater similarity between cells in vivo and in vitro is evident with adult Sertoli cells; and (3) the adult marmoset monkey could provide a primate model for mature Sertoli cells in culture, since there is a close similarity to human adult Sertoli cells in vitro and in vivo.

Aging↗