SCP and crude pectinase production by slurry-state fermentation of lemon pulps

Single cell protein (SCP) and crude pectinolytic enzymes production from citrus pulps is reported. SCP and enzymes were produced by slurry-state flask cultivation of Aspergillus niger and Trichoderma viride on pulps from lemon juice clarification. Production as well as crude pectinase activity was not affected by the high dry matter content of the pulps. Both the protein content in the residue and the enzyme activity in the supernatant were higher in T. viride than in A. niger culture. The crude pectinase of T. viride, whose specific activity was similar to that found for a commercial concentrated preparation, could be utilized in the same citrus processing factory as well as in other factories which use large amounts of pectinolytic crude preparations, for example to enhance depuration plant performance.

Hepatocyte growth factor is a regulator of monocyte-macrophage function

Hepatocyte growth factor (HGF) is a potent paracrine mediator of stromal/epithelial interactions, which is secreted as a matrix-associated inactive precursor (pro-HGF) and locally activated by tightly controlled urokinase cleavage. It induces proliferation and motility in epithelial and endothelial cells, and plays a role in physiological and pathological processes involving invasive cell growth, such as angiogenesis and parenchymal regeneration. We now report that HGF induces directional migration and cytokine secretion in human monocytes. Monocyte activation by endotoxin and IL-1beta results in the up-regulation of the HGF receptor expression and in the induction of cell-associated pro-HGF convertase activity, thus enhancing cell responsiveness to the factor. Furthermore, we provide evidence for the secretion of biologically active HGF by activated monocytes, implying an autocrine stimulation. Altogether, these data indicate that monocyte function is modulated by HGF in a paracrine/autocrine manner, and provide a new link between stromal environment and mononuclear phagocytes.

Modulation of alpha-actin and alpha-actinin proteins in cardiomyocytes by retinoic acid during development

Early heart development is known to be sensitive to retinoid concentrations. Although the influence of retinoids on cardiac morphogenesis has been described previously, the effect of retinoids on cardiomyocyte differentiation during development has not been characterized. We quantified the effects of the retinoic acids all-trans RA and 13-cis RA on alpha-actin and alpha-actinin at the subcellular level in cultures of chick embryo cardiomyocytes obtained from Hamburger and Hamilton's (HH) stage 22, 32 and 40 embryos. The retinoids increased the concentration of alpha-actin and alpha-actinin in the cytoplasmic and cytoskeletal fractions of cells at all three stages of development. The effect was greatest in cardiomyocytes treated for 24 h with all-trans RA and in cells from HH22 embryos. The greatest increases in alpha-actin concentration occurred in the cytoskeletal fraction of HH22 cells cultured for 24 h with all-trans or 13-cis RA, whereas the greatest increases in alpha-actinin were found in the cytoplasmic fraction of HH22 cells exposed to retinoids for 24 h. We conclude that retinoic acid plays a role in the reorganization of the pattern of sarcomeric protein expression during cardiomyocyte differentiation.

Modulation of myogenic differentiation in a human rhabdomyosarcoma cell line by a new derivative of 5-fluorouracil (QF-3602)

The in vitro study of mechanisms involved in drug-induced maturation has made it possible to use differentiation-based therapy in clinical practice. The goal of this new therapy is the development of specific agents to induce cancer cells to stop proliferating and express characteristics of normal cells. Recently, by structural modifications of 5-fluorouracil (5-FU), we synthesized a new pyrimidine acyclonucleoside-like compound, 1-¿[3-(3-chloro-2-hydroxypropoxy)-1-methoxy]propyl¿-5-fluorouracil (QF-3602), which showed in rhabdomyosarcoma cells a low toxicity and time-dependent growth inhibition. In this work, we compared the degree of myogenic differentiation of RD rhabdomyosarcoma (RMS) cells after treatment with QF-3602 and 5-FU. Scanning and transmission electron microscopy (SEM and TEM) and immunocytochemical analyses showed that QF-3602 induced the appearance of myofilaments along the myotube-like giant RD cells, an increase in fibronectin and a decrease in vimentin expression. In contrast, only minor changes were observed with 5-FU. Moreover, polymerase chain reaction (PCR) analyses showed that QF-3602 did not induce overexpression of the mdr 1 gene, a resistance mechanism that frequently appears in classical cytotoxic therapy in these tumors. Compounds obtained by structural modifications of 5-FU may be useful in differentiation therapy as a new approach to the treatment of RMS.

Met overexpression confers HGF-dependent invasive phenotype to human thyroid carcinoma cells in vitro

The proto-oncogene c-MET encodes the tyrosine kinase receptor for hepatocyte growth factor (HGF), a pleiotropic cytokine controlling growth, survival, motility, invasive migration, and differentiation of epithelial cells. Like several other epithelial neoplasms, thyroid carcinomas have been found to overexpress c-MET at both the mRNA and protein level. The biological relevance of Met overexpression to thyroid carcinoma natural history, however, remains to be elucidated. Therefore, we analyzed Met expression and response to HGF in two cell lines established from human thyroid carcinomas. In both lines we observed that the overexpressed and constitutively tyrosine phosphorylated HGF receptor maintained biochemical responsiveness to the ligand. Both cell lines were also found to respond to HGF by consistently increasing their motility and invading in vitro reconstituted basal membranes. Conversely, no effect of HGF could be observed in proliferation and survival assays. These data show that overexpression of Met specifically confers to transformed thyroid cells a motile-invasive phenotype that is dependent on exogenous HGF stimulation.

GR-891: a novel 5-fluorouracil acyclonucleoside prodrug for differentiation therapy in rhabdomyosarcoma cells

Differentiation therapy provides an alternative treatment of cancer that overcomes the undesirable effects of classical chemotherapy, i.e. cytotoxicity and resistance to drugs. This new approach to cancer therapy focuses on the development of specific agents designed to selectively engage the process of terminal differentiation, leading to the elimination of tumorigenic cells and recovery of normal cell homeostasis. A series of new anti-cancer pyrimidine acyclonucleoside-like compounds were designed and synthesized by structural modifications of 5-fluorouracil, a drug which causes considerable cell toxicity and morbidity, and we evaluated their applicability for differentiation therapy in human rhabdomyosarcoma cells. We tested the pyrimidine derivative GR-891, (RS)-1-[[3-(2-hydroxyethoxy)-1-isopropoxy]propyl]-5-fluorouracil, an active drug which shows low toxicity in vivo and releases acrolein which is an aldehyde with anti-tumour activity. Both GR-891 and 5-fluorouracil caused time- and dose-dependent growth inhibition in vitro; however, GR-891 showed no cytotoxicity at low doses (22.5 micromol l(-1) and 45 micromol l(-1)) and induced terminal myogenic differentiation in RD cells (a rhabdomyosarcoma cell line) treated for 6 days. Changes in morphological features and in protein organization indicated re-entry in the pathway of muscular maturation. Moreover, GR-891 increased adhesion capability mediated by the expression of fibronectin, and did not induce overexpression of P-glycoprotein, the mdr1 gene product, implicated in multidrug resistance. New acyclonucleoside-like compounds such as GR-891 have important potential advantages over 5-fluorouracil because of their lower toxicity and their ability to induce myogenic differentiation in rhabdomyosarcoma cells. Our results suggest that this drug may be useful for differentiation therapy in this type of tumour.

Optimization of the tyrosinase mRNA probe to detect circulating melanocytes with reverse transcription and polymerase chain reaction

It was recently suggested that reverse transcription polymerase chain reaction (RT-PCR)-based detection of tyrosinase messenger RNA (mRNA) in peripheral blood is useful in the early detection of circulating tumor cells, since tyrosinase is thought to be a melanocyte-specific marker. However, the sensitivity of detection of these cells in circulation is controversial, some authors reporting 0% effectiveness, others obtaining 100% efficacy. We developed a modification of a technique to process blood samples to detect tyrosinase mRNA, and tested the method with 50 samples from as many patients with histologically confirmed malignant melanoma in different stages. Whole blood was processed by discarding the plasma and extracting RNA from density gradient-isolated peripheral blood lymphocytes. The RNA samples were tested with a sensitive nested primer RT-PCR assay. Sensitivity was tested using RNA extracted from SK-mel-1 human melanoma cells diluted serially with peripheral blood obtained from healthy control subjects. A lymph node from a patient with confirmed disseminated melanoma served as the positive control. Our technique was able to detect tyrosinase mRNA in samples from the 37 patients with progressive metastatic melanoma. The test detected tyrosinase mRNA from both the melanoma cell line and the positive lymph node. Our method to extract RNA from whole blood improves the specificity and sensitivity of tyrosinase mRNA detection by RT-PCR. The test should be of use in determining the prognosis of patients with melanoma, and in deciding when to initiate early treatment in patients with malignant melanoma.

Characterization of a new human embryonal rhabdomyosarcoma cell line, RMS-GR

A human tumor cell line designated RMS-GR was established from an embryonal rhabdomyosarcoma. The monolayer cells were polygonal, round or spindle-shaped. The RMS-GR cell line became stable with a doubling time of 42 h. Tumorigenicity of the cells was confirmed by heterotransplantion into nude mice. Electron microscopic images showed typical cytoplasmic inclusion of aggregated intermediate filaments and myofibril-like thin filaments. The expression of desmin, vimentin, actin and human myoglobin was recognized by cytofluorometric analyses, and a large fraction of CK-MM and small fractions of CK-BB and MCK-1 isoenzymes were found. Chromosomal analysis showed that the modal chromosome number was consistently near triploid with structural abnormalities mostly involving chromosomes 1, 3 and 8, and additional unidentified markers. No alteration of chromosome 2 was observed. The RMS-GR cell line may provide a system to identify genes which are involved in the pathogenic mechanism of rhabdomyosarcomas, and to investigate the modulation of myogenic differentiation.

Low sample volume causes differentiation in human rhabdomyosarcoma cell line RD subjected to electroporation

Gene transfection has been accomplished with a variety of techniques such as DEAE dextran, calcium phosphate coprecipitation, protoplast fusion, liposomes, microinjection and recombinant bacteriophages. However, transfection by electroporation, consisting of the reversible permeabilization of cell membranes after exposure to a pulsed electric field, has been shown to be the most rapid, simple and efficient method for the stable incorporation of genes in different cell lines. We studied rhabdomyosarcoma cells subjected to electroporation in two different vol. [400 microliters (group 1) and 150 microliters (group 2] of 140 mM NaCl/15 mM Hepes buffer, pH 7.2) and evaluated the effects of electroporation volume on growth and differentiation. Low sample volumes induced a terminal process of morphological and ultrastructural myogenic differentiation in rhabdomyosarcoma cells, which concluded with cell death. Our results suggest that in electroporation low sample vol. of rhabdomyosarcoma cells induced morphological and phenotypic differentiation, with increased expression of desmin, alpha-actinin and tropomyosin.

Overexpression and activation of hepatocyte growth factor/scatter factor in human non-small-cell lung carcinomas

Hepatocyte growth factor/scatter factor (HGF/SF) stimulates the invasive growth of epithelial cells via the c-MET oncogene-encoded receptor. In normal lung, both the receptor and the ligand are detected, and the latter is known to be a mitogenic and a motogenic factor for both cultured bronchial epithelial cells and non-small-cell carcinoma lines. Here, ligand and receptor expression was examined in 42 samples of primary human non-small-cell lung carcinoma of different histotype. Each carcinoma sample was compared with adjacent normal lung tissue. The Met/HGF receptor was found to be 2 to 10-fold increased in 25% of carcinoma samples (P = 0.0113). The ligand, HGF/SF, was found to be 10 to 100-fold overexpressed in carcinoma samples (P < 0.0001). Notably, while HGF/SF was occasionally detectable and found exclusively as a single-chain inactive precursor in normal tissues, it was constantly in the biologically-active heterodimeric form in carcinomas. Immunohistochemical staining showed homogeneous expression of both the receptor and the ligand in carcinoma samples, whereas staining was barely detectable in their normal counterparts. These data show that HGF/SF is overexpressed and consistently activated in non-small-cell lung carcinomas and may contribute to the invasive growth of lung cancer.

Collagen synthesis and cell growth in chick embryo fibroblasts: influence of colchicine, cytochalasin B and concanavalin A

Culturing of chick embryo fibroblasts in the presence of colchicine or cytochalasin B with and without concanavalin A (Con A) demonstrated that colchicine induces greater neosynthesis of endocellular type I collagen, whereas cytochalasin B boosts secretion. The effects are modified by the addition of Con A, which increases alpha 2 more than a1 chain production. 3H-thymidine incorporation is unaffected by cytochalasin B, but stimulated by colchicine. Con A neutralizes the stimulatory action of colchicine. It would therefore seem that Con A exerts transmembrane control of effects induced by colchicine and cytochalasin B by binding to cell surface receptors and so triggering rearrangement of the cytoskeleton.

Modulation of phenotypic expression of fibroblasts by alteration of the cytoskeleton

Several studies indicate that the cytoskeleton may be involved in modulating the cellular response to environmental signals. We have studied the role of the cytoskeleton in regulating glycosaminoglycan (GAG) synthesis and secretion, hyaluronate (HA) endocytosis, the activities of hexoglycosidases, protein synthesis and secretion. Fibroblasts were treated with colchicine (1-8 microM) and nocodazole (1 or 4 microM) to alter microtubules or cytochalasin B (0.5-4 microM) to alter microfilaments. Colchicine inhibited GAG synthesis and secretion in a concentration-dependent manner. It reduced protein and sulphated GAG secretion, while HA secretion was not affected. Concentration-dependent disruption of microtubules from the periphery toward the cellular centre with nocodazole inhibited only the secretion of GAG. Centrosomal microtubles appeared to be required to promote GAG synthesis; intact microtubules promoted the transport of secretory products, intercompatmental transport of lysosomal enzymes and lysosome maturation, but not protein synthesis and HA secretion. Cytochalasin B treatment inhibited, in a concentration-dependent manner, the synthesis and secretion of GAGs and proteins, and the endocytosis of HA. Intact microfilament meshworks appeared to be required to promote synthesis and secretion of proteins and proteoglycans and to contribute to the transmembrane control of receptor-mediated endocytosis. Drug treatment of concanavalin A (Con A)-stimulated fibroblasts inhibited the stimulation of GAG synthesis. It is probable that this effect may result, in part, from drug-induced effects on Con A-mediated endocytosis.

[Collagenous colitis. Morphologic and immunohistochemical study]

Collagenous colitis is a clinico-pathological entity characterized by chronic diarrhoeas and deposition of collagen beneath the epithelium surface of large bowel. We revised 265 endoscopy biopsy specimens of the large bowel from 198 consecutive patients with "aspecific chronic colitis". Morphometric study showed that were not significant differences among various tracts in the same patients regarding to the thickness of basament membrane. It was more than 11.9 +/- 0.49 mu only in 13 pts (6.6%), while it was 3.96 +/- 1.4 mu in the others. Immunohistochemistry study confirmed the normality of subepithelial basement membrane and the below deposition of the large quantity of collagen IV.

Hyaluronic acid modulates growth, morphology and cytoskeleton in embryonic chick skin fibroblasts

The action that hyaluronic acid (HA) exerts on cell proliferation was investigated in embryonic chick skin fibroblasts at different ages (7-14 days) and in different cell-cycle stages evaluated by flow cytometry (cells maintained with and without serum). Proliferation was estimated by 3H-thymidine incorporation and cell counting. The results demonstrated hyaluronic acid inhibits cell multiplication in all different environmental conditions examined. The inhibitory effect of HA is more evident in 14-day than 7-day old fibroblasts. The ability of HA to modulate 3H-thymidine incorporation did not involve a change in the time required for cells entering the S phase of the replicating cycle, but is due to a smaller number of cells entering in this phase. As the relationships between components of the extracellular matrix (ECM) and the cytoskeleton are known, parallel studies were carried out on some cytoskeleton proteins. Furthermore, by modifying the capacity of cells to adhere to the substrate, HA induced alterations in cell shape and in cytoskeleton components involved in these processes. We may hypothesize that HA, binding specific membrane receptors, affects cell adhesion and morphology inducing less receptivity of fibroblasts to mitogenic stimuli by transmembrane interactions with cytoskeleton.

Renal cell (Grawitz) carcinoma: an immunohistochemical study in correlation with nuclear grade, histological pattern and proliferative activity of tumor cells

Since morphological features of renal cell carcinomas may not always predict their clinical behaviour, other biological parameters are more and more searched for, as prognostic indicators. Among those, the Authors evaluate the cytokeratin-vimentin intermediate-sized filaments co-expression in a series of 32 renal carcinomas and analyze this feature in correlation with both traditional criteria and proliferative activity of tumor cells, studied by means of the proliferation cellular nuclear antigen (PCNA) expression as well as of the nucleolar organizer regions (NORs) count, within tumor cells. From this study, nuclear grade stands out as the best parameter which, furthermore, shows a significant relationship with the cytokeratin-vimentin co-expression and the mean NORs count in tumor cell populations. Further investigations about relationships between these parameters and survival of the patients, who, at present, are almost all alive, will be performed afterwards.

Fluorescence cytometry of microtubules and nuclear DNA during cell-cycle and reverse-transformation

Synchronized CHO-K1 cells and their dibutyryl c-AMP treated counterparts have been characterized by means of static and flow fluorescence cytometry at the level of nuclear DNA and cytoplasmic microtubules. In order to confirm earlier findings on synchronized population, Carnoy fixed and hydrolyzed, several new findings are here reported at the level of single intact cell. The fluorescence intensity of DAPI-stained glutaraldehyde fixed 2C cells correlates well with the average absorbance of the corresponding Feulgen-stained cells, thereby appearing also to be a measure of chromatin condensation during the G1 phase. In the early part of G1, the drastic alteration in anti-beta tubulin immunostaining is shown to parallel microtubule depolymerization induced by calcium or colcemide. The known 1-2 h lengthening of the G1 period after reverse-transformation appears to correlate with a similar delay in the abrupt chromatin decondensation. The above results are discussed in terms of the role of microtubules and nuclear morphometry (and their coupling) in the control of cell cycle progression of transformed vs. fibroblast-like cells.

Effects of spermidine synthase inhibition in cultured chick embryo fibroblasts

The administration of bis-cyclohexylammonium sulfate (BCHS), a spermidine synthase inhibitor, to in vitro cultures of chick embryo fibroblasts caused a decrease in cellular spermidine levels and an increase in putrescine and spermine. Cell proliferation rate and DNA synthesis were also inhibited. As protein synthesis did not change, it would seem that low levels of cellular spermidine inhibit cell growth depressing DNA synthesis.

Modulation of phenotype and cytoskeleton architecture by interleukin-1 alpha in human osteoblast-like cells in vitro

Interleukin-1 alpha, a growth factor produced by macrophages as well as many other types of cells, is able to modulate biosynthetic activities in bone cells. In this work, the authors show that the administration of interleukin-1 alpha to osteoblast-like cells in vitro induces a marked change in cell morphology, which becomes dendritic, with a smaller cellular body and numerous prolongations. The morphological changes are also accompanied by an altered expression in the pattern of cytoskeleton proteins.

[Argyrophilic nucleoproteins of the cervical epithelium in HPV infection and intraepithelial neoplasia]

50 colposcopic biopsies of cervical epithelium were studied, using a silver colloid technique. These comprised 28 cases of human papillomavirus infection of the cervix, 8 cases of cervical intraepithelial neoplasia (CIN) I, 8 cases of CIN II, 6 cases of CIN III. The AgNOR mean number of the basal and parabasal cells of the cervical epithelium was significantly different in virus infected cells and in CIN. Different patterns of AgNOR distribution were observed: they were single and compact in virus infection without dysplasia whereas they appeared small and often loosely arranged in dysplastic lesions. Our data suggest that this simple technique is diagnostically useful in the evaluation of borderline lesions.

Characterization of the cytoskeleton in human normal and otosclerotic osteoblast-like cells

The localization and distribution of some cytoskeletal protein components were studied by immunostaining methods in normal and ostosclerotic osteoblast-like cells. The protein components investigated were microtubules (beta-tubulin), intermediate filaments (vimentin), microfilaments (actin and myosin) and structural proteins (alpha-actinin and fibronectin). Although the mechanism is not yet clear, the alterations observed in the pathological cells could well play a role in the expression of otosclerosis.

[Angiosarcoma of the breast]

Two cases of angiosarcoma of the breast observed in 1981 and 1982 are reported; one of these is still living, but with local recurrence. The pathogenesis, classification, prognosis and therapy of this malignant tumor are analysed. The review of the literature and personal experience seem to suggest that the treatment of choice should be surgical with complementary radiotherapy.

Cybrids and heterokaryons PEG-induced between D. discoideum amoebae and mouse fibroblasts

Optimal conditions for fusion of Dictyostelium discoideum amoebae with mouse fibroblasts using polyethylene glycol (PEG) are described. Three different kinds of experiments were done to look for the ways to obtain new cell lines heterokaryons or cybrids. In all cases, the final products of the fusion were cells showing new features, still viable for at least one week. To detect the cell membrane fusion, samples were observed by scanning electron microscope (SEM).

Toxic megacolon complicating ulcerative colitis and Crohn's disease

The clinical, laboratory and radiological data of 17 cases of toxic megacolon (TM) complicating either ulcerative colitis (UC) or Crohn's disease (CD), referred to the Department of Clinica Chirurgica II of the University of Bologna in a twenty year-period, are reviewed. The surgical strategies and results are compared and discussed, and the mortality and morbidity considered along with the important advances in resuscitative medicine and the employment of total parenteral nutrition (TPN).

[Embryo-toxic effects of nickel sulfate in Paracentrotus lividus: preliminary observations]

A primary objective of the work described here was to determine the embryo-toxic effects induced by Nickel Sulfate upon the development of the Paracentrotus Lividus. Different concentrations of Nickel Sulfate have been dissolved in containers with not foul sea-water. The fecundation took place in the containers and verified by constant observations with a light microscope. The development of the Paracentrotus 1. was totally blocked at a concentration of 0.5 M.10(-2) of Nickel Sulfate, while an enormous development was observed at concentrations of 0.5 M.10(-3) and 0.5 M.10(-4). Finally, a concentration of 0.5 M.10(-5) caused a slow development. A normal development was observed only at a concentration of 0.5 M.10(-6). Our results support various hypotheses on the mechanism of action of the Nickel Sulfate as an inhibitor of the normal development.

[Alpha-actinin sites on microvilli of the rabbit small intestine demonstrated by immunoperoxidase]

When Mooseker and Tilney showed the microvilli system must be ascribed among non-muscle contractile systems, they have proposed a contractile scheme formed by actin, miosin and probably alpha-actinin. The scheme proposed by these AA. consists of actin filaments oriented and running from the border to the base, bound to the border by a plate of dense substance formed by -actinin and, to the base, other perpendicular miosin filaments. In our opinion, Mooseker and Tilney research lacks a demonstration regarding alpha-actinin and that is reason why we have decided to display this protein in the microvilli by immunoperoxidase techniques. Considering our results we can definitively confirm the full validity of the contractile scheme of Mooseker and Tilney.

[Immunohistochemical observations on tubulin and alpha actinin during mitosis of cultured fibroblasts]

In this work we studied alpha-actinin and tubulin sites in rabbit fibroblasts in culture. Antibodies anti-alpha-actinin were used for indirect PAP-reaction while antibodies anti-tubulin were used for indirect immunofluorescence method. The observations were carried out by light microscopy, phase-contrast and interference-contrast microscopy, with regard to actinin, and by fluorescence microscopy, with regard to tubulin. During the early mitotic phase, alpha-actinin is localized all over the cell membrane of the fibroblasts, forming a sort strong protective cap, while during diacinesis it forms only rings, localizing below the cell membrane and the philopodia. Thus tubulin forms the bundle fibres during mitotic phases.

[Structural and ultrastructural changes in the rabbit myocardium exposed to dimethylformamide vapors]

The aim of this research is to show the alterations of alpha-actinin in rabbit myocardium after DMF treatment administered by forced inhalation. Z-lines observed with light and phase-contrast microscopy, appeared to be intact and they were clearly displayed by the indirect PAP-reaction. But if you consider that in normal muscle Z lines do not get coloured by the PAP-reaction without a previous light treatment with trypsin. It may be inferred that, in this case, The DMF has had the same effect as the trypsin, causing alteration to the protein structure. Besides the sarcomeric structure is undoubtedly altered by the DMF, causing alterations, in our opinion, similar to those found in rabbit skeletal muscle, under conditions of acute experimental ischemia.

[Morphological changes alpha-actinin in skeletal striated muscle in the rabbit in experimental ischemia]

In this work we studied the alteration of Z-line alpha-actinin in striated skeletal muscle, under conditions of experimental ischemia, by immunohistochemical techniques. alpha-Actinin was extracted and purified from rabbit striated skeletal muscle and used, as an antigen, for the production of antibodies, in sheep. Electrophoresis was performed on PAA sla-gel and the Ag-Ab reaction test on agarose slab-gel (immunodiffusion). Antibodies were used for the indirect immunoperoxidase technique on semithin sections of rabbit striated skeletal muscle, included in in Araldehyde, and observed with phase-contrast microscopy. alpha-Actinin from ischemic muscle because of stenosis of the iliac artery, undergoes a progressive alteration, from the third hour of ischemia, going out of its usual sites. From the fifth to the eighth hour it gradually disappears until it leaves rare and residual points of positive reaction only in correspondence to the Z-lines.

[Dynamic aspects of alpha-actinin in cultured rabbit fibroblasts studied with immunofluorescence]

In this work we study alpha-actinin sites in rabbit fibroblasts in culture. For this purpose we extracted alpha-actinin from rabbit striated skeletal muscle and produced the relative antibodies in sheep. Electrophoresis was performed, on PAA slab-gel and the immunodiffusion test on agarose slab-gel. Antibodies were used for direct and indirect immunofluorescence techniques by TRIC and FITC. We noticed that in young fibroblasts alpha-actinin is concentrated in perinuclear regions, while in adult fibroblasts it is scattered, more or less evenly in the cytoplasm and above all on the plates which link the cell membrane to the substractum. Both the direct immunofluorescence method with antibodies anti-alpha-actinin, marked by TRITC, and the indirect one with sheep IgG, marked by FITC, gave identical results.

[Myofibrils and autophagic vacuoles during atherosclerotic ischemia in man]

The various cases of ultrastructural changed in human skeletal muscles in an ischemic state have been examined. From the examination of the material used, it results that in these muscles, certain myelinic figures and autophagic vacuoles are present. These figures are at times linear and in order, whereas in other regions the lamellar components reveal to be disorganized. In many cases, the larger myelinic figure is near the nucleus, almost next to it. Even electron-dense membranes that surround crystalline inclusion placed between the myelinic figures have been observed. The presence of autophagic vacuoles and myelinic figures is important. The cause of this presence is probably due to a different state of degeneration of the different regions in which these vacuoles are or are not present. Both the autophagic vacuoles and the myelinic figures are found associated with the proteolysis of the tissues. Because of these observations, it has been hypothesized that these changes are a consequence of degeneration. Nonetheless, these changes could be caused by both ischemia and atrophy caused by denervation contemporarily, when the above happens in subjects forced to a long-term immobile state, or in an advanced state of gangrene, or during contemporary and associate phlogistic processes with deficient peripheral nervous structures.