Morphologic and biochemical changes in the lymphoid and hematopoietic tissues of rats with Zajdela hepatoma

The growth of allogeneic ascites hepatoma is accompanied by involution of the thymus, leukemoid response and anemia. Tumor cells disseminate throughout the body appearing in many organs including the spleen, liver, bone marrow and lymph nodes. The activity of adenosine deaminase and the adenosine deaminase/purine nucleosidephosphorylase ratio decrease in the host thymus as well as in the cellular elements of the spleen. The above phenomena reflect the impairment of lymphocyte differentiation and presumably contribute to the decreased efficiency of the host immune response.     

Morphologic and biochemical variability of tissue and cultured cells from human pheochromocytoma

Primary cell cultures from 18 human pheochromocytomas were maintained in culture for 10 to 12 days and characterized. The cell yields ranged from 1.0 to 60.1 X 10(6) cells/g wet weight of tissue. Cell size, as determined by histofluorescent microscopy, varied as much as seven-fold among cells derived from a given tumor and ten-fold between cells from all tumors. Cell catecholamine content, norepinephrine (NE) plus epinephrine, ranged from 0.4 to 89.5 nmol/10(6) cells at day 5 in culture and did not correlate with catecholamine content of the tissue from which the cells were obtained. Cell catecholamine content decreased with time in culture, but this decrease could not be related to a change in cell viability, the type of media used, an inability to convert dopamine to NE, or an alteration in the uptake of 3H-NE. Cellular uptake of 1.0 microM 3H-NE varied as much as 230-fold between all cell dispersions. The basal and acetylcholine stimulated release of both preloaded 3H-NE and the endogenous catecholamines was quite variable. There was no correlation between the release rate, either basal or stimulated, of preloaded 3H-NE and the endogenous catecholamines. This study represents the largest existing data base on culturing cells from these tumors and describes many of the morphologic and biochemical characteristics of this cell system.     

Interactions of extracellular collagen and corneal fibroblasts: Morphologic and biochemical changes of rabbit corneal cells cultured in a collagen matrix

Summary Corneal fibroblasts, also known as keratocytes are surrounded by an extracellular matrix of collagen in vivo. To understand the physiology and pathology of these corneal fibroblasts, it is important to study their interactions with this extracellular matrix. We cultured rabbit corneal fibroblasts on tissue culture plastic dishes or in a hydrated collagen gel and compared the changes in morphology and mitotic activity. Corneal fibroblasts on plastic dishes were flattened and widely spread, whereas those in collagen gel became spindle-shaped with long processes. Examination with an electron microscope revealed that the corneal fibroblasts in collagen gel formed gap junctions with neighboring cells. Gap junctions were hardly ever observed between corneal fibroblasts cultured on plastic dishes. Corneal fibroblasts cultured in a collagen matrix showed much less incorporation of [³H]thymidine than did corneal fibroblasts cultured on plastic, and this incorporation decreased with increasing concentration of collagen. Our present results suggest that the morphologic and biochemical characteristics of corneal fibroblasts cultured in collagen gel are different from those cultured on plastic. This research was supported in part by grants from the Ministry of Education, Science and Culture of Japan, by a grant from Osaka Eye Bank, Osaka, Japan, and by an intramural research fund of Kinki University. Part of this research was presented at the annual meeting of the Japanese Ophthalmological Society (May 1985) at Kyoto, Japan, and at the annual meeting of the Association for Research in Vision and Ophthalmology (May 1987) at Sarasota, FL.     

Morphologic and molecular changes in target cells during in vitro interaction with macrophages.

Recent work has indicated that macrophages can affect eukaryote cells in a variety of ways. The inhibitory or enhancing effects on target cell proliferation are mediated by soluble factors released from macrophages and appear to affect every replicating cells. Macrophages have also been shown to affect target cell viability and this destructive potential was initially considered to be tumor-specific. The present work further assesses these macrophage effects on targets by morphologic and fluorimetric methods. Morphologic analysis of the interaction between activated nonimmune macrophages (AM) and tumor cells attests to close cell-to-cell contact as an important factor in the mediation of target cell damage. All evidence suggests that damaged targets progressively disintegrate, and residues of target cell cytoplasma and/or nucleus are then engulfed as a secondary event. Analysis by impulse cytophotometry of the alterations in the DNA distribution occurring during interaction with AM revealed a marked decrease in the number of nuclei with higher DNA content. This effect was virtually identical irrespective of whether target cells were derived from normal or transformed tissues. Analysis of the consequences of AM/target cell interaction by cytofluorimetry showed that a large proportion of tumor cells lyse in the course of the interaction. However, no such killing occurred in recent explants derived from normal tissues interacted with AM; the majority of these targets were arrested in G1.     

Morphologic and biochemical heterogeneity of lysosomes]

By means of isopycnic centrifugation in the continuous density gradient of sucrose two subfractions of lysosomes were isolated from rat liver homogenates: a "light" one (with the floating density p=1.13) and a "heavy" one (p=1.24). Electron microscopic, enzymatic and electron microscope enzymatic analysis of the isolated subfractions showed that the "light" subfraction consisted mainly of newly-formed primary lysosomes, while the "heavy" one was presented by secondary lysosomes. Parallel biochemical investigations demonstrated a considerable enzymatic heterogeneity of the two lysosomal subfractions: the "light" subfraction was characterized by a high specific activity of acid DNase, acid RNase and beta-galactosidase, and by almost total absence of beta-glucosidase activity, while the "heavy" one was characterized by a high specific activity of beta-glucosidase, beta-glucuronidase and beta-N-acetylglucosaminidase. Possible causes of enzyme heterogeneity of rat liver lysosomes are discussed.     

Morphologic and biochemical study of stimulated collagenogenesis

A study was made of the effect of potassium orotate on wound healing. The duration of wound healing was 3 days less in animals given potassium orotate as compared to controls, with the rate of prolin-containing protein synthesis by fibroblasts and the rate of their egress into the intercellular space being increased. No excess fibrillogenesis was noted. Hydroxyprolin content in the granulation tissue of wounds differed little in control and in experimental animals.     

Relationship between lead-induced biochemical and behavioral changes with trace element concentrations in rat brain

Lead has an obvious potential to disturb learning ability, adaptive responses, and other aspects of behavior and even personality in those who may appear healthy according to conventional medical criteria. These disturbances are shown to be associated with alterations in ionic, cholinergic, and dopaminergic neurotransmission in the central nervous system (CNS). The present experiment was designed to study the neurotoxic consequences of lead exposure on neurotransmitters like dopamine, serotonin, norepinephrine, and activity of acetylcholinestrase, as well as some ions like zinc, calcium, sodium, and potassium. The locomotory functions along with cognitive functions and memory loss were also studied at various dose levels. Lead was administrated orally in doses of 10 mg/kg, 50 mg/kg, and 200 mg/kg for a period of 12 wk and the study was done at the end of exposure. A dose-dependent decrease in the concentration of sodium, potassium, and zinc was observed; there was increase in the concentrations of lead and calcium. The most significant change noted was the decrease in activity of the acetylcholinestrase and other neurotransmitters. Lead exposure affected the locomotor and cognitive functions. Short-term memory remained unchanged at all lead exposure doses.     

Effects of chronic irradiation on age-related biochemical changes in mice

Some of the biochemical indices relevant to the "free radical theory" of aging have been assessed in mice subjected to chronic low-dose whole-body irradiation. Radiation exposure results in enhanced accumulation of the lipofuscins in brain, heart, and intestine. In these animals, the degree of lipoperoxidation in liver was greatly increased, as were the free activities of acid phosphatase and cathespin, indicating damage to lysosomal membranes. The activity of SOD in brain and liver 20,000g post-mitochondrial supernatants was lower in the irradiated mice. All these changes arising from chronic whole-body irradiation are similar to those observed during aging and are effectively prevented by dietary supplementation with BHT. These observations lend considerable support to the "free radical theory" of aging.     

Morphologic and phenotypic changes of human neuroblastoma cells in culture induced by cytosine arabinoside

The effects of cytosine-arabinoside (ARA-C) on the growth and phenotypic expression of a new human neuroblastoma (NB) cell line (GI-ME-N) have been extensively tested. Low doses of ARA-C allowing more than 90% cell viability induce morphological differentiation and growth inhibition. Differentiated cells were larger and flattened with elongated dendritic processes; such cells appeared within 48 h after a dose of ARA-C as low as 0.1 micrograms/ml (about 1000-fold lower than the conventional clinic dose). The new morphological aspect reached the maximum expression after 5-6 days of culture being independent from the addition of extra drug to the culture. A decrease in [3H]thymidine incorporation was also observed within 24 h and the cell growth was completely inhibited on the sixth day. Moreover, ARA-C strongly inhibited anchorage-independent growth in soft agar assay. Membrane immunofluorescence showed several dramatic changes in NB-specific antigen expression after 5 days of treatment with ARA-C. At the same time ARA-C also modulated cytoskeletal proteins and slightly increased catecholamine expression. These findings suggest that noncytotoxic doses of ARA-C do promote the differentiation of GI-ME-N neuroblastoma cells associated with reduced expression of the malignant phenotype.     

High-intensity exercise training produces morphological and biochemical changes in adrenal gland of mice

The effects of training are dependent on complex, adaptive changes which are induced by acute physical exercise at different levels. In particular, evidence shows that the hypothalamus-pituitary-adrenocortical axis, as well as the sympatho-adrenomedullary system, is mainly involved in mediating the physiological effects of physical exercise. The aim of the present study was to investigate, through a morphological and biochemical approach, the effects of training on the adrenal gland of mice, following two different protocols consisting of either low- or high-intensity training. Mice were run daily on a motorised treadmill for 8 weeks, at a velocity corresponding to 60% (low-intensity exercise) or 90% (high-intensity exercise) of the maximal running velocity previously determined by an incremental exercise test. We found that physical exercise produced an increase in the adrenal gland size compared with the control (sedentary) mice. The increase was 31.04% for mice that underwent high-intensity exercise and 10.08% for mice that underwent low intensity exercise, and this appeared to be the result of an increase in the area of both the adrenal cortex and adrenal medulla. Morphological analysis of the adrenal cortex showed that both types of exercise produced an increase in cytoplasmic vacuoles in steroidogenic cells, appearing more abundant after high-intensity exercise. No change was found in the reticulate zone. In the adrenal medulla, despite the absence of morphological changes, immunohistochemistry for tyrosine hydroxylase, dopamine β-hydroxylase and phenyl-ethanolamine-N-methyltransferase demonstrated an increased immunopositivity for these cathecolamine-synthesizing enzymes after intense exercise. These results were confirmed by immunoblot accompanied by densitometric analysis.     

Cocaine-induced biochemical changes and cytotoxicity in hepatocytes isolated from both mice and rats

The mechanism of cocaine-induced cytotoxicity was investigated in hepatocytes isolated from both male C3H mice and male Sprague-Dawley rats. Cocaine was more cytotoxic to mouse hepatocytes than rat and induced reduced glutathione (GSH) depletion prior to marked increases in cytotoxicity in both systems. In both mouse and rat cells, GSH depletion was accompanied by GSSG production, but in rat cells, quantitative measures suggested that other mechanisms contributed to GSH depletion. No cocaine-induced depletion of protein-thiol groups or generation of protein-glutathione mixed disulfides could be detected in rat cells. Cocaine induced lipid peroxidation, using malondialdehyde (MDA) production as an index of the peroxidation process, in both mouse and rat hepatocytes. Inhibition of MDA production to below control levels using the antioxidant N,N'-diphenyl-phenylene diamine (DPPD) however, had no inhibitory effect on cocaine-induced cytotoxicity in either mouse or rat cells. These data suggest that neither generalized protein thiol depletion nor lipid peroxidation are critical determinants of cocaine-induced cytotoxicity in cellular systems.     

Morphologic and biochemical studies of chitin expression in Pneumocystis carinii.

Tomato lectin, which binds oligosaccharides of N-acetyl-D-glucosamine, and an antiserum against macromolecular chitin were used to probe sections of human and murine lungs infected with Pneumocystis carinii. By light, fluorescence and electron microscopy, lectin and antiserum binding patterns indicated that both human and murine strains of P. carinii express chitin at all identifiable stages of their life cycles. Light microscopic autoradiographs of murine P. carinii cultured in vitro with 3H-glucosamine revealed dense incorporation of the radiolabel into the cell walls in a pattern analogous to those of the antiserum and lectin binding studies. These investigations offer further evidence that chitin is an integral part of the cell wall of P. carinii trophozoites and cysts.