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PubMed1986

Experimental bacteremia and hepatic nutrient blood flow.

To study altered hepatic nutrient blood flow during the early phases of bacteremia, Sprague-Dawley rats (250-350 gm) underwent carotid cannulation; 24 hr later, they received an intravascular infusion of 2.5 X 10(8) Escherichia coli (LD70) over 45 min. Controls were anesthetized and cannulated only. Experimental and control animals then received a flow-dependent dose of indocyanine green (5 mg/kg) via the cannula, and arterial blood was sampled at 3, 4, 5, 6, 7, and 8 min after. Separate groups of animals were studied at 3 and 6 hr after bacteremia. The half-life (t1/2) of indocyanine green clearance was then determined at each time period, with t1/2 representing an estimation of total hepatic nutrient blood flow. Results indicated a prolonged t1/2 at both time periods in the bacteremic rats. Hepatic histology from plastic-embedded sections appeared to reveal fibrin, platelets, and leukocyte fragments within the sinusoids. From these data, we conclude that reduced nutrient blood flow occurs during experimental bacteremia prior to systemic changes of arterial pressure.

Animals↗
PubMed1986

Anatomy of the mouse retina. Endothelial cell-pericyte ratio and capillary distribution.

A technique is described for preparing whole retinal vascular digests using distilled water and DNase. This produces a more satisfactory preparation of the mouse retinal vascular bed than "trypsin digestion." Nonetheless, the calculation of endothelial cell/pericyte (E/P) ratios based on cell counts from digest preparations has poor reproducibility due to the inability to unequivocally identify at least 25% of the cells in conventionally stained (PAS and hematoxylin) preparations. A more accurate and reproducible means of assessing this ratio uses 1 micron sections of plastic-embedded sections of retina. No effect of age, sex, strain, or area of sampling was found. Capillaries were in three specific bands, centered on the nerve fiber layer, the junction of inner plexiform and inner nuclear layers, and the outer plexiform layers.

Animals↗
PubMedDate not supplied

Neuroblastoma diagnosed by fine needle aspiration biopsy.

Small-cell malignancies of childhood are a source of diagnostic difficulty, both in cytology and histology. Four cases of neuroblastoma are presented that were diagnosed by fine needle aspiration cytology. The importance of a complete history, physical examination and laboratory evaluation is stressed. In addition to the usual description of cytologic detail obtained by routine methods, a new method of study is introduced: the potential use of plastic embedding and histochemical studies in small-cell tumors is discussed.

Adolescent↗
PubMed1985

[Pigment and ion transport in the vestibular organ].

Pigments are found in various parts of the inner ear, especially in the neighbourhood of epithelia, which are supposed to be involved in the secretion and/or absorbtion of the endolymphatic fluid. Microprobe analysis (laser absorption mass micro analyzer "LAMMA" and X-ray) combined with morphological observations were performed in shock frozen, freeze-dried and plastic embedded inner ear tissue from the vestibular organ of pigmented guinea pig. Disturbance of the endolymphatic ionic composition (increased Na+) due to treatment with metabolic inhibitors (ethacrynic acid, ouabain) stimulated the migration of pigment granules and displacement of the dentritic processes of the melanocytes in a close vicinity to the presumably transporting vestibular epithelia (the dark and light cells and capillaries). The melanosomes obtained full range of metal ions that changed characteristically after treatment with metabolic inhibitors. It could be supposed that melanin presents some kind of reservoir for essential trace elements or compounds and may regulate numerous enzymatic and membrane functions by binding and releasing the metal ions.

Animals↗
PubMed1985

Isolation of microtubule coils from normal human platelets.

The blood platelet is the only human cell known to have a circumferential band of microtubules. However, the mechanisms involved in assembly of the multi-looped coil, its interaction with the cell membrane to support discoid shape, and constriction into tight rings around centrally concentrated organelles in activated platelets are unknown. Separation of the microtubule rings from intact platelets would permit new approaches to solution of these questions. The present study has used simultaneous detergent extraction and fixation to isolate intact microtubule coils in significant numbers from suspended platelets for the first time. Isolated coils closely resembled the circumferential band observed in thin sections of plastic embedded platelets and in platelets prepared by the negative-stain whole-mount method. Enough microtubule coils could be recovered from suspensions of concentrated platelets to permit counting and quantitation on microscope grids. Results of this study will permit new approaches to clarification of the structural physiology of platelet microtubule coils.

Adult↗
PubMed1973

Differential interference contrast microscopy of human atherosclerotic lesions.

Differential interference contrast microscopy was employed to study sections of human cerebral arteries and aorta. When this procedure was used to observe 0.5-mu-thick sections of plastic-embedded arteries, images were obtained with greater definition of detail than corresponding micrographs of the area using conventional bright-field microscopy. Since structures with different refractive indices are shown in geometric relief from one another, an apparent three-dimensional image is seen, which, together with the theoretically higher resolution and contrast achieved by this technic, gives an image with definition between conventional light and low magnification electron microscopy. The morphology of fatty streak lesions with aggregates of round and elongated lipid-filled cells was demonstrated, and clear images of different forms and sizes of intracellular lipid droplets were illustrated at magnifications around 1000. In atheromatous plaques, intra- and extracellular lipid droplets were observed, some with partially extracted cores or surfaces, as were amorphous lipid droplets coalescing with crystals whose centers had been extracted. We conclude that this optical accessory to a research photomicroscope is a valuable supplemental tool in studies on the morphology of atherosclerotic lesions.

Aorta↗
PubMed1979

[Electron-cytochemical method of DNA detection with the aid of ammonia silver].

Three prescriptions for the detection of aldehyde groups of deoxyribose with ammoniac silver are proposed. The reaction can be carried out on tissue blocks or imprints; it is useful for DNA identification in the light and electron microscope, gives high contrast and allows to reveal DNA in structures with a relatively low content of DNA, for instance, in nucleoi. The disadvantages of the method include a possibility of nonspecific reduction of silver if the reaction is performed on a plastic-embedded material and damage of ultrastructures if the reaction is done prior to embedding.

Ammonia↗
PubMed1979

Morphological definition of a case of 'usual' interstitial pneumonia.

A 61-year-old Caucasian female complained of shortness of breath, fever, and a period of rapid weight loss. After routine studies, the patient underwent an open lung biopsy in order to define the characteristics of the interstitial lung disease, and initiate appropriate therapeutic intervention. Typical fibrotic and cellular proliferation were evident in the parenchyma, as determined by standard light microscopy. However, in a correlated study using light microscopy of plastic embedded tissue, as well as scanning and transmission electron microscopy, a major proliferating cell type was identified as a type II pneumocyte. These cells were the predominant lining cells of the alveoli and clearly protruded into and limited available respiratory air spaces. The predominance of type II pneumocytes in the pathogenesis of certain respiratory diseases requires that a better explanation be sought for this phenomenon.

Female↗
PubMed1978

A morphologic study of intracerebral hemorrhage in a case of acute leukemia.

Morphologic studies have thus far failed to demonstrate the nature of the vessel involved in the brain hemorrhages of patients with acute leukemia. A detailed study of such hemorrhages was carried out in a patient with leukemic phase of mycosis fungoides. Plastic-embedded lesions showed that blast cells blocked the lumen of the capillary, leading to severe dilation and rupture of the vessel. The rheologic properties of blast cells in vessels of critical diameters seem to be an important factor in the pathogenesis of intracerebral hemorrhages.

Acute Disease↗
PubMed1979

Ultrastructure of hematoxylin bodies in systemic lupus erythematosus.

Two specimens, the first from a percutaneous renal biopsy and the second autopsy tissue of ovary, from two subjects with active systemic lupus erythematosus were found to contain many striking hematoxylin bodies in the walls of several small arteries. The specimens were reprocessed for electron microscopy; in one case, corresponding plastic embedded sections were also stained with hematoxylin-eosin and Feulgen stain. Hematoxylin bodies were easily identified on electron microscopy. They were found to be dense, homogeneous structures, approximately the size of a nucleus. They probably represent mainly altered nuclear material with occasional small chromatin remnants or minor cytoplasmic inclusions.

Adolescent↗
PubMed1983

The cellular infiltrate of the contact sensitivity reaction to picryl chloride in the mouse.

Contact sensitivity to picryl chloride was studied in the mouse ear. The skin hypersensitivity, as a factor of ear swelling, and the intensity of the cellular infiltrate in the skin were evaluated together during the elicitation of the contact sensitivity reaction. It was found that the ear swelling is a mainly vascular reaction preceding the appearance of inflammatory cells. The infiltrating cells in this model of skin sensitivity were differentiated in Giemsa-stained plastic-embedded sections and recorded in a semi-quantitative way. When the cellular reaction was most intense at 48 and 72 hours after challenge, the most numerous inflammatory cells were lymphocytes and eosinophils.

Animals↗
PubMed1982

Dyggve-Melchior-Clausen syndrome. A histochemical study of the growth plate.

UNLABELLED: The Dyggve-Melchior-Clausen syndrome is a rare inherited disorder in which a major feature, the skeletal dysplasia, is thought to result from a defect in endochondral ossification. To further characterize this disturbance, histochemical studies were performed on an iliac-crest biopsy specimen from a patient with disorder. The use of plastic embedding methods permitted previous observations, which were based on decalcified paraffin-embedded tissues, to be extended and a variety of new ones to be made. The resting cartilage matrix was very fibrous. In many areas it consisted of randomly oriented bundles of loosely woven fibers that stained as collagen. The chondrocytes in this region were excessively vacuolated and many contained cytoplasmic inclusions that stained non-specifically as protein. Cartilage canals were prominent in the resting cartilage. In many areas, clusters of degenerating chondrocytes and occasional vacuolar lesions replaced the columns of proliferating and maturing cells that normally occupy the growth-plate region. There was coarse and irregular calcification of these clusters at the chondro-osseous junction, and intracartilaginous ossification was also found. CLINICAL RELEVANCE: These observations further define the histological criteria for the diagnosis of this disorder and provide new insights into its pathogenesis.

Bone Diseases, Developmental↗
PubMed1981

Glucose utilization in the central nervous system in the acute gliopathy due to 6-aminonicotinamide.

Sprague-Dawley rats were injected intraperitoneally with 5 mg. per kg. of 6-aminonicotinamide. The local glucose utilization rate (LGU) was measured throughout the central nervous system using the (14C) 2-deoxyglucose, quantitative autoradiographic technique at 3, 6, 12, and 24 hours after injection. The histologic appearance of selected areas of central nervous system was studied at 6, 12, and 24 hours and 3 and 10 days after injection, following perfusion by buffered aldehydes and plastic embedding. Decreases in LGU o 25 to 36 per cent were found in the lumbar ventral horn, caudal brain stem, and cerebellum at 3 and 6 hours. By 12 hours, virtually all of the structures examined showed decreases in LGU greater than 20 per cent with the reduction in the cord being 40 to 50 per cent. At 24 hours, the majority of areas exhibited definite recovery of LGU. Mild glial swelling, particularly of oligodendroglia, was noted at 12 hours and was obvious by 24 hours. Neuronal changes were not seen. These abnormalities were most marked in the intermediate and ventral gray matter of the cord and certain brain stem nuclei. 6-Aminonicotinamide has a known inhibitory effect on the pentose phosphate shunt and a secondary effect on the direct glycolytic pathway. The reduction in LGU is probably due to the inhibition of these pathways in both glia and neurons, but, the recovery LGU at 24 hours when the glial pathology was increasing suggests that the glia may metabolically protect the neuron at times of stress.

6-Aminonicotinamide↗
PubMed1984

Subcellular distribution of potassium in striated muscles.

Microanalytical experiments have been performed to answer the question whether the main cellular cation, K+, follows the water distribution in the striated muscle cell or whether K+ follows the distribution of negative fixed charges (beta- and gamma-carboxyl groups of aspartic and glutamic acid residues). Subcellular localization of K and/or of the K surrogates Rb, Cs, and Tl has been investigated by the following methods: Chemical precipitation of K with tetraphenylborate. Autoradiography of alkali-metals and Tl in air-dried and frozen-hydrated preparations. TEM visualization of electron dense Cs and Tl in sections of freeze-dried and plastic embedded muscle. X-ray microanalysis of air-dried myofibrils and muscle cryosections. The experiments consistently show that K, Rb, Cs, and Tl do not follow the water distribution but are mainly accumulated in the A band, especially in the marginal regions, and at Z lines. The same sites preferentially accumulate Cs or uranyl cations when sections of freeze-dried, embedded muscle are exposed to these electron microscopic stains. It is concluded that the detected uneven distribution of K, Rb, Cs, and Tl in muscle is neither a freeze-drying artifact nor an embedding artifact and may result from a weak ion binding to the beta- and gamma-carboxyl groups of cellular proteins.

Animals↗
PubMed1984

Morphometry of normal human lymphoid tissues. Nuclear invaginations and clefts.

We performed morphometric analysis on samples of human lymphoid tissue involved by reactive hyperplasia to assess the basis for the concept of cleaved lymphocyte nuclei in current non-Hodgkin's lymphoma classification. Histologic sections from all regions of lymph node showed considerable variation (usually 9% to 16%) in the proportion of nuclear profiles, with invaginations of at least 0.4 micron. Invaginations sufficiently deep to label nuclear profiles as "cleaved" occurred in 2% or less of lymphocytes of all regions seen on 1-micron plastic-embedded sections. The majority of nuclear invaginations were less than 1.6 micron deep. Analysis of the morphometric data suggests that the nuclei of germinal center lymphocytes undergoing antigen-induced transformation do not progress through a specific phase in which they become increasingly cleft. With the increased angularity and irregularity of lymphocyte nuclear profiles in germinal centers, the "cleaved" appearance of these nuclei in paraffin-embedded sections seems to be due to linear creases and overlapping segments of the nucleus.

Adolescent↗
PubMed1984

Megakaryopoiesis in chronic myeloproliferative diseases. A morphometric evaluation with special emphasis on primary thrombocythemia.

Morphometry was employed on different entities of chronic myeloproliferative diseases (CMPD) and reactive lesions in addition to normal control specimens. The entities studied included: (1) inflammatory reactions of the bone marrow (so-called myelitis in chronic rheumatoid arthritis), (2) chronic granulocytic leukemia (CGL), (3) agnogenic myeloid metaplasia in an early hypercellular stage (so-called chronic megakaryocytic-granulocytic myelosis, CMGM), (4) agnogenic myeloid metaplasia in an advanced fibrosclerotic stage or osteomyelofibrosis/sclerosis (MF/OMS), (5) polycythemia vera (P. vera), (6) reactive thrombocytosis (TH, as a sequel of miscellaneous conditions) and (7) primary (idiopathic, essential) thrombocythemia (PTH). Evaluation was done on plastic-embedded semithin sections with a constant thickness of 3 micron in approximately 20 cases of each group of CMPD. The following parameters were determined: (1) density distributions of the megakaryocyte and non-megakaryocyte compartments, (2) arrangement of megakaryopoiesis in the bone marrow space (i.e., inhomogeneity or clustering) and (3) the fine structure of megakaryocytes in PTH, with a quantitative analysis of the nuclear morphology by circular deviation and contour factors. The megakaryocyte morphology was closely related to a facultative or obligatory increase of the platelet count in these various entities of CMPD and was separable into two major categories: (1) controls, CGL and myelitis versus (2) CMGM, MF/OMS, P. vera, TH and PTH. These two categories were distinguishable by the prominence of megakaryopoiesis in the bone marrow as well as the elevated platelet counts in the periphery. Moreover, in comparison with CMGM and MF/OMS, PTH was characterized by an apparently normal maturation and a conspicuous polyploidization of megakaryocytes according to the nuclear morphology, which was similar to that of P. vera. Our results suggest that PTH presents a monolinear growth of the megakaryopoiesis in the same way as CGL exhibits a monolinear proliferation of the neutrophilic granulopoiesis. This is in contrast to the mixed cellularity of both the megakaryocyte and granulocyte lineage in CMGM and MF/OMS.

Biopsy↗
PubMed1983

Combined energy detector-wavelength dispersive spectrometer electron probe microanalysis of biological soft tissue samples.

A Si(Li)energy detector has been coupled with a fully automated, four wavelength dispersive spectrometer electron probe microanalyzer for analysis of freeze-dried, plastic-embedded biological tissue samples. Through the use of a suitable absorber, the unwanted portion of the energy spectrum is suppressed, thus reducing overall counting rate in the energy detector to the point where it is possible to use electron beam currents with high intensities, typical of wavelength dispersive spectrometer operation, while using the configuration of highest energy detector solid angle available in our electron probe microanalyzer. The electron probe automation software has been extended to permit control of the energy detector simultaneously with control of the electron microprobe. A software stopwatch permits accurate compensation for differences between energy detector and wavelength spectrometer dead times. A region of continuum in the energy spectrum is calibrated against background for the spectrometers to provide a different number representing background for each spectrometer. This background information is provided simultaneously with on-peak data collection by treating each region of interest from the Si(Li) energy detector spectrum as an additional data line in the electron probe microanalyzer computer automation package.

Animals↗
PubMed1983

Occlusion of the neural lumen in early mouse embryos analysed by light and electron microscopy.

A histological account of neural tube occlusion during early mouse embryogenesis is presented here from an analysis of sections taken from plastic-embedded material. Because the overall pattern of neuroepithelial apposition and the duration of luminal occlusion appears to vary slightly from one embryo to another at otherwise similar stages of development, only a general guide to the events occurring in the mouse embryo between about midday on the 9th to late on the 10th day of gestation can be given. The earliest evidence of complete luminal occlusion was seen when the cephalic and caudal extremities of the neural tube were still widely open. An ultrastructural analysis of the morphological appearance of the closely apposed luminal cells in zones of partial and complete occlusion has demonstrated that occlusion is brought about initially by the interdigitation of processes from closely apposed neuroepithelial cells. This initial event is followed by direct contact over a much more extensive area between the surfaces of apposed cells with a characteristically flattened luminal border. Apposition and luminal occlusion is probably facilitated by the presence of viscous extracellular material. Finally, complete occlusion involving an extensive region of the lumen occurs. The latter phenomenon is a transient event lasting 1 or at most 2 days in the mouse. At no stage were junctional complexes observed between closely apposed neuroepithelial cells in regions in which the neural lumen appeared to be completely occluded, though they were apparent between adjacent neuroepithelial cells. Observations on the underlying mechanism(s) of cellular fusion are considered in the light of the ultrastructural findings. These results are compared with findings from analyses of various other sites of cellular fusion during embryogenesis. Attention is also drawn to the similarities and differences observed in the timing and overall pattern of events occurring during the early development of the neural tube in mouse and human embryos.

Animals↗