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The development of the paraxial mesoderm in tadpoles of Xenopus, Bufo and Rana was observed with a scanning electron microscope. In addition to examination of the differentiation of the surface and the interior of the somites, some attention was also paid to the transformation of the material of the neural crests and to the innervation of the developing myotome.
The exfoliating epithelial surface of 15 invasive squamous carcinomas of the uterine cervix was investigated with the aid of the scanning electron microscope (SEM). At low magnification (less than or equal to 5,000 X) thirteen tumors presented irregular cobblestone-like structures and the remaining two, irregular intermediate formations (i.e. between cobblestones and mosaics). Cellular overlapping was found in three tumors. At higher magnifications (up to 25,000 X) all 15 tumors showed irregular disorganized structures such as bizarre microvilli with or without fragmented microrugae. Seven tumors had in addition tall finger-shaped protrusions and two rumors crater-like formations covered by irregular microvilli. The SEM structure found in invasive squamous carcinoma differed from the SEM structures earlier reported for the normal squamous or glandular epithelium, squamous metaplasia, dysplasia or carcinoma in situ of the uterine cervix.
Two new methods now allow the systematic examination of the morphology and micropathology of the initial lymphatics (lymph sinuses and precollectors) in human skin biopsy specimens under the scanning electron microscope. Pertinent studies and findings in the intact skin of anesthetized pigs demonstrate the standard quality of the biopsy preparations. The following are new findings made with these methods: in the skin of the human head, both the lymph sinuses and the precollectors extend as far as the epidermis. The opening apparatus of these vessels consists not only of anchoring filaments and interendothelial openings, but also of endothelial bridges and trabeculae. The interendothelial openings can be present in three types of transformation (Type I-III). As part of these studies, an attempt was made to standardize the lymphological nomenclature so that it would be acceptable to both anatomists and clinicians.
BACKGROUND: The study reported here was performed to investigate morphologic intraocular reactions on the surface of metallic intraocular foreign bodies (IOFB) with scanning electron microscopy. METHODS: Twenty-seven extracted IOFB were investigated. Of these, 22 were situated in the vitreous body; 19 had contact with the retina. Five IOFB had been removed from the anterior segment (control group). The duration of intraocular retention was 6 h to 24 days. Immediately after microsurgical removal the IOFB were fixed, dehydrated, dried, sputter-coated and investigated with a scanning electron microscope. Two IOFB from the vitreous were treated for collagen preservation. RESULTS: Eighteen of 20 intravitreal IOFB showed fibers of fibrin on its surface; 11 of 20 were covered with a homogeneous layer. Within this layer a net of collagen fibers was detectable. A major cellular reaction was observed only on IOFB that injured the retina, pigment epithelium and choroid. CONCLUSIONS: This morphologic study shows that: (1) a fibrin net develops in the vitreous around intravitreal IOFB; (2) depositions of amorphous material into the spaces of this net lead to dense coverage of the IOFB; (3) cellular reactions are not condition for the development of this coverage; (4) laceration of the retina induces a fibrocellular response.
A 32-year-old patient, known to suffer from paroxysmal cold hemoglobinuria, developed a marked immunoblastic reaction in the peripheral blood and bone marrow following pneumonia and pericarditis, most probably of viral origin. Transmission electron microscopic examination showed cells with irregular nucleus, scarce heterochromatin and well-developed Golgi formation. The surface ultrastructure examined with a scanning electron microscope was characterized by the presence of ridges, ruffles and blebs on the cell membrane. Since the patient underwent splenectomy 23 years prior, the possible role of the spleen in the removal of the immunoblasts from the peripheral blood of patients with viral infections is discussed.
Blood vessels with amyloid angiopathy and senile plaques in the cortices of the brains with Alzheimer's disease and senile dementia were observed by means of a scanning electron microscope. the results obtained were as follows: The blood vessels with amyloid angiopathy were surrounded by solid substances. The senile plaques consisted of rough solid substances, contained degenerated cell processes, and almost all plaques existed around the degenerated capillaries with amyloid angiopathy. From the above described findings, we suggest that the senile plaque has an extremely cose relationship to the capillary which had undergone amyloid angiopathy.
The microstructure and location of impurities in polar ice are of great relevance to ice core studies. We describe a reliable method to examine ice in the scanning electron microscope (SEM). Specimens were cut in a cold room and could have their surfaces altered by sublimation either before (pre-etching) or after (etching) introduction to the cryo-chamber of the SEM. Pre-etching was used to smooth surfaces, whilst etching stripped away layers from the specimen surface, aiding the location of particles in situ, and allowing embedded structures to be revealed. X-ray analysis was used to determine the composition of localized impurities, which in some cases had been concentrated on the surface by etching. Examining uncoated surfaces was found to be advantageous and did not detract from qualitative X-ray analysis. Imaging uncoated was performed at low accelerating voltages and probe currents to avoid problems of surface charging.
Morphologic characteristics related to ecology and evolutionary sequences, and to specific, generic, and familial relations, can now be determined with the scanning electron microscope. These detailed characteristics will help to establish a more natural faunal classification and will enable more accurate ecologic and biostratigraphic correlations.
The aim of the present study has been to correlate the surface appearance of pitted, fluorosed enamel in the scanning electron microscope (SEM) with the microradiographic features of the underlying tissue. Intact enamel surfaces of severely fluorosed teeth appeared similar to that of normal enamel. In the unabraded surfaces discrete pits were sharply demarcated from the surrounding intact enamel surface leaving steep walls of parallel running rods. The microradiographic appearance of sections made through pits indicated that focal loss of surface enamel occurred corresponding to the inner highly hypomineralized part of the fluorotic subsurface lesion. The abrupt wall formation and the finding that the striae of Retzius never changed direction along the margins of the lesions indicated that pits in fluorosed enamel may be secondarily produced defects rather than true hypoplasias. Further evidence of the posteruptive origin of the defects was derived from the observation that enamel lamellae occasionally formed part of the lateral border. The relatively higher degree of radiopacity observed in the tissue surrounding the pit indicates a posteruptively acquired deposition of minerals in the exposed porous enamel.
The aggregates of washed control and NANAse-treated human red blood cells (RBC) were characterized by scanning electron microscopy (SEM). Aggregation of RBC was performed under well-defined laminar shear conditions (78.6 S-1) in a horizontally arranged coaxial cylinder system. Generally, with increasing La3+ concentration in the PBS the aggregates became larger and the contact between the RBC "more intensive". This was evidenced by more cells per aggregate, an enlargement of contact areas, a change of cell shape in the contact region and signs of fusion phenomena. Especially at high La3+ concentrations on the cell surface of treated and untreated RBC some deposits were seen by SEM which are possibly La3+- phosphate precipitates. Neuraminidase treatment promoted the described La3+ effects. Concanavalin A-induced RBC agglutinates were different from the more spherical former ones and showed a network-like morphology. The conclusions drawn on the basis of light and scanning electron microscopical investigations are confirmed by quantitative values of an aggregation index estimated in parallel.
Three-dimensional structures were analyzed on 32 human colonic adenomas, 5 hyperplastic polyps, 4 normal colonic mucosa and 5 advanced colonic carcinomas with Scanning Electron Microscope (SEM) and with sequential serial sectioning. After SEM observation, the samples were softened with 2% NaHCO3 and observed with histological serial sectioning. By combining both techniques, that is combined analysis of outer structures for SEM and inner structures for serial sectioning, three dimensional analysis of the colonic adenoma and carcinoma in adenoma were successfully completed. The colonic adenomas were classified into 6 types based on the surface structure observed by SEM as Type I (circular type), Type II (long-elliptical type), Type III (branched type), Type IV (gyral type), Type V (wrinkle type) and Type VI (complicated type). Classified Types I, II, III and IV were observed in tubular adenoma, and grades of atypia seemed to be increased as increasing type numbers. Type V, in tubulo-villous adenoma and villous adenoma, were found out and showed severer atypia than observed in Type IV. Among 32 adenomas, 3 portions of focal cancers were detected, and the surface structures of them had highly complicated patterns as shown with Type VI.
The functional and morphological characteristics of the fungiform papillae (FuP) on the anterior dorsal surface of the cat and rabbit tongues were studied and compared using a scanning electron microscope (SEM), because the comparison of the functional and morphological relationship of FuP in microvascular cast specimens (MVCS) between these tongues is as yet not clear. In both species, FuP were found to be distributed sporadically among the numerous filiform papillae (FiP). In the cat, in particular, FuP were classified into four types (FuP I-IV) according to the shape and size of a main process (MP) and the number of accessory processes (AP). Each FuP, (FuP I-III lay along oblique lines of FiPs) contained a MP and many APs lying at the anterior basal margin of the MP, whereas FuP IV contained only the small fishnet-ball-shaped MP. In the rabbit, however, only the similar size and shape of the capillary loops, resembling the carnation flower, were scattered among FiPs on the anterior dorsal surface of the fore-tongue. These results suggest that in comparing the functional sense mechanism in both species, the FuP of the rabbit tend to be more simple than those of the cat in respect to taste sense.
The surface characteristics of the lower respiratory tract of two groups of cattle were studied with the scanning electron microscope. Group A comprised six one-week-old calves and group B four adult cows. None of the animals had overt respiratory disease or gross morphological evidence of pulmonary lesions. The trachea, bronchi, bronchioles and alveoli of the cranial and the caudal lobes of the right lung were examined. In both groups the luminal surface of the trachea and large bronchi were completely covered by cilia, apparently forming an efficient mucociliary escalator. In the adult animals there were some patchy areas in the trachea and large bronchi devoid of ciliated cells; these were considered abnormal. In the bronchi, non-ciliated cells, mainly mucus-secreting, were not easily identified unless they were discharging secretion. In small bronchi, non-ciliated cells were more evident and easily seen. The bronchioles had many non-ciliated cells and very few ciliated cells capable of forming a complete carpet for a mucociliary escalator. Types 1 and 2 alveolar epithelial cells and alveolar macrophages were identified in both groups. Pores of Kohn were found in the alveolar walls in all animals.
The arachnoid villi of 18 dogs were studied. The authors confirmed the pressure gradient changes of the morphology of arachnoid villi of dogs with the scanning electron microscope (SEM). A subarachnoid infusion with 5--10 times higher pressure gradient than the physiological one, tore the superficial endothelial layer from the villi, and the inner part could also be observed stereoscopically. On the surface of the arachnoid villi, the authors observed microvilli, openings of vacuoles and intercellular gaps, but did not find openings of performed channels. After subarachnoid haemorrhage (SAH) generally the villi were blocked but the authors have observed a red blood cell escaping from a villus intercellularly.
A scanning electron microscope (SEM) was used to compare the proximal region (PR) and distal region (DR) of the caecum. The caecal tonsil (CT) occupied the initial 4-10 mm of the PR. Villi were present in the PR and absent from the DR. Segmented structures were attached to the surface of PR. Transmission electron microscopy (TEM) revealed these structures to be bacteria. No difference in surface morphology could be discerned between the CT and the remainder of the PR. Lymphatic vessels were observed in the CT by employing TEM.
Large-bore catheters for extracorporeal detoxification methods without and with treated surface with silver or silicone were investigated after removal with a scanning electron microscope and for bacterial colonization. In 42 large-bore catheters of three different materials, small deposits of fibrin and protein on the inner and outer surface were seen. This second layer covered the entire surface after 3 days and increased to a thickness of 3 to 60 microns during the following days. Bacterial colonization was observed in 38.1%. In contrast to these results, the catheters with the treated outer surface showed a very low thrombogenicity and a low contamination rate of 6.7%.
Orally administered cadmium has been known to cause diarrhea and flatulence of the gastrointestinal tract. Scanning electron microscopic observations revealed that the absorptive cells on the tip of the intestinal villi were affected to some extent by administration of 2.5 microgram CdSO4/10 g of body weight (b. w.). Administration of higher doses of CdSO4 made the microvilli of the absorptive cells sparse and caused degeneration of the cells. Strong enzymic activities of alkaline phosphatase, acid phosphatase, magnesium-dependent ATPase, and sodium-potassium-dependent ATPase were recognized at the microvilli of the absorptive cells of the villi in the control mice. The enzymic activities of magnesium-dependent ATPase and sodium-potassium-dependent ATPase became weak with increasing dosages of CdSO4. The microvilli of the absorptive cells showed a strong alkaline phosphatase activity at a dose less than 25 microgram CdSO4/10 g of b. w., while some inhibitory effects could be recognized with 50 microgram/10 g of b. w. After administration of 2.5 microgram CdSO4/10 g of b. w., no acid phosphatase reaction products were found only at the absorptive cells located on the tip of the villi. Administration of a large quantity more than 5 microgram/10 g of b. w. strongly affected the acid phosphatase activity. It may be possible that the digestive functions are impaired by low cadmium administration.
Rhesus monkeys have been kept in horizontal position under klinostatic or antiorthostatic hypokinetic conditions for 7 and 19 days. Using scanning electron microscope, studies were made of the otolithic membrane of the utricle, the receptor surface of the utricle, crista ampullaris of the lateral semicircular canals, the organ of Corti, the stria vascularis and spiral ligament. No significant differences were found between control and experimental animals.