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Biomedical subjects

F Reyes

Publications and source records attributed to F Reyes.

At least 163 records · Page 9Linked to original sources
PubMed1976

Lytic enzymes in the autolysis of filamentous fungi.

The degrees of autolysis attained by five different genera of filamentous fungi during an incubation period of 60 days, under the same culture conditions were: 87.3% for Penicillium oxalicum; 65.9% for Neurospora crassa; 62.7% for Polystictus versicolor; 51.7% for Aspergillus niger and 23.5% for Nectria galligena. N. crassa, A. niger and P. versicolor reached the end of the autolysis during this incubation period (60 days), whereas P. oxalicum and N. galligena did not. The excretion of the lytic enzymes beta-N-acetylglucosaminidase, beta -1-3 glucanase, chitinase, invertase and acid phosphatase into the culture medium during growth and autolysis was investigated. The excretion of these enzymes was consistent with the degree of autolysis reached, the maximum excretion belonging to P. oxalicum and the minimum to N. galligena. The N. crassa invertase was excreted into the culture liquid at levels very much higher than the other enzymes studied, and at levels very much higher than the invertases excreted by the other fungi.

Acetylglucosaminidase↗
PubMed1976

Elastogenesis in adenomatoid tumor: histochemical and ultrastructural observations.

An adenomatoid tumor from the round ligament of a 50-year-old woman was studied by light and electron microscopy. Ultrastructurally the tumor was remarkably similar to normal as well as neoplastic mesothelium, thus lending further support to the concept of a mesothelial origin of adenomatoid tumors. Comparative histochemical and ultrastructural studies revealed presence of acid mucopolysaccharides mainly along the luminal borders of the tumor cells, thus indicating likely production of this material by the tumor cells as opposed to the stromal cells. The stroma was rich in elastic fibers and there was evidence of active elastogenesis. This paper represents the first unequivocal demonstration of elastogenesis in an adenomatoid tumor.

Adenoma↗
PubMed1976

The cellular distribution of erythrocyte and normoblast A1 and A antigens in normal and preleukemic states. An immunoelectron microscopy study.

A1 and A alloantigens were visualized on human erythrocytes and normoblasts by immunoelectron microscopy using peroxidase-coupled antibodies. Specimens were obtained from patients with preleukemia and associated antigen weakening, and from individuals with normal antigen values. Cells were fixed by glutaraldehyde and subsequently reacted with antibodies.

ABO Blood-Group System↗
PubMed1976

Surface features of cells in human lymphoproliferative disorders. An immunoelectron microscopy study.

Peroxidase conjugated antibodies were applied to cell suspensions in order to detect surface associated immunoglobulins. Cell suspensions were fixed prior to incubation with reagents, a procedure avoiding membrane alterations induced by antibodies to surface component. By immunoelectron microscopy an identification of B lymphocytes could be made with simultaneous observation of their surface architecture. Basic findings were that normal circulating human B lymphocytes had a villous surface. This relationship was not confirmed however by examinating samples from various B and T cell proliferations establishing that surface morphology is not sufficient to categorize cells in disease. Specimens from hairy cell leukemia were also examined. Despite salient surface characteristics as revealed by the present method, the categorization of cells remains unclear.

B-Lymphocytes↗
PubMed1976

Liberation of protoplasts from mycelium of Neurospora crassa by means of enzymes obtained from autolyzed cultures of this fungus.

Spherical protoplast-like structures were released from Neuropsora crassa mycelia under the influence of cell-wall-lytic enzymes obtained from autolyzed cultures of this fungus, in 50 mM borate-citrate-phosphate buffer, pH 5.5 with 0.5-0.8 M mannitol for appropriate osmotic pressure. The protoplasts retain their morphological aspect for several days at 4 C, or for a longer time when they are washed by centrifugation and incubated with 0.8 M mannitol. The free protoplasts are sensitive to osmotic shock and lyse immediately when placed in distilled water; the vacuoles and other cytoplasmatic material remain intact for some time.

Autolysis↗
PubMed1976

[Heterogeneity of the cellular distribution of erythrocytic A antigens. Ultramicroscopic study].

A and A1 antigens have been detected on cells of the human erythrocyte series by immunoelectron microscopy. These antigens have been revealed by an indirect method involving various anti-A and anti-A1 antibodies (allo, auto, hetero-antibodies) and peroxidase-conjugated anti-immunoglobulin antibodies. Immunologic labelling has been carried out with erythrocyte or bone marrow cell suspensions which were fixed prior to incubation with reagents. Cells from various A phenotypes were examined. A and A1 antigens were visualized on maturing normoblasts, at every developmental stage. In addition cell to cell variations of the surface labelling of erythrocytes was found in normal phenotypes, suggesting the existence of several populations of cells according to antigenic load.

ABO Blood-Group System↗
PubMed1976

Reproductive endocrinology of female chimpanzees: a suitable model of humans.

Similarities between reproductive processes in humans and chimpanzees have led to speculation that the chimpanzee might be an excellent reproductive-endocrine model of humans. Data comparing patterns and concentrations of serum gonadotropins, prolactin, and sex steroids in female humans, chimpanzees, and rhesus monkeys sustain this concept. The striking evidence that levels of estrone, estradiol, estriol, progesterone, and chorionic gonadotropin are similar during human and chimpanzee pregnancy support the contention that chimpanzees, like humans but unlike rhesus monkeys, have a definitive fetoplacental unit. Likewise, during normal menstrual cycles serum patterns of LH, FSH, progesterone, and estradiol are similar in women and chimpanzees, but differ in rhesus monkeys. Thus by using the chimpanzee it may be possible to accurately assess the safety for human use of compounds that might affect reproductive-endocrine processes without direct exposure to humans.

Animals↗
PubMed1976

The heterogeneity of erythrocyte antigen distribution in human normal phenotypes: an immunoelectron microscopy study.

A and A1 antigen were detected on human blood erythrocytes by immunoelectron microscopy using peroxidase-conjugated antibodies. Cells were obtained from various normal A subgroups, including rare weak A phenotypes and infant (cord blood) samples. Erythrocytes were fixed prior to incubation with specific reagents. The detection of surface antigens was carried out by an indirect method involving anti-A and anti-A1 antibodies and conjugated anti-immunoglobulin antibodies. The surface labelling was seen as a diffuse dense layer. Haemperoxidase-like activity resulted in a faint background which did not interfere at the level of ultrathin sections, with surface staining due to exogeneous peroxidase. The most significant finding was the existence, in a given sample, of several populations of cells as revealed by their antibody-binding capacity. The distribution of the various populations varied from one sample to another according to its subgroup. The progressive weakening of phenotype expression which characterizes the various subgroups from A1 to A weak was paralleled by a decreasing number of "antigen rich" cells, which were still detectable in weak phenotypes as a minor population. This study confirms that a given normal phenotype in fact represents a mixture of antigenically different populations of erythrocytes.

ABO Blood-Group System↗
PubMed1976

[Acute monoblastic leukemia. Clinical and therapeutic aspects in 20 cases].

Twenty cases of acute monoblastic leukemia are studied according to definite criterias: cytology, cytochemical staining, lysozyme production. The study points out the tumoral characters: hematodermy, gingivitis, central nervous system leukemia and the lack of important bone marrow incompetence. 47 per cent of complete remissions are obtained with daunorubicin, aracytin combination therapy. Other useful chemical agents, and prospects for maintenance therapy are discussed.

Adolescent↗
PubMed1976

[Morphologic criteria of surface studies by electron microscopy and classification of lymphoproliferative syndromes. Critical study].

Surface associated immunoglobulins (s.Ig) have been detected on human lymphocytes, in normal individuals and in disease, by an immunoelectron microscopic method using peroxidase-labeled antibodies. Experiments have been carried out on fixed cell suspensions, in order to avoid membrane alterations induced by anti-immunoglobulin antibodies. Normal human blood B lymphocytes have a villous surface. However this relationship between microvilli and detectable s.Ig, as found in the normal state, is not confirmed by examinating various T and B cell proliferative states. Thus surface morphology alone is not sufficient for classifying cells in disease. The precise nature of mononuclear cells from hairy cell leukemia remains nuclear.

B-Lymphocytes↗
PubMed1975

The surface morphology of human B lymphocytes as revealed by immunoelectron microscopy.

Surface immunoglobulins (sIg) were detected on human lymphocytes by immunoelectron microscopy with peroxidase-conjugated antibodies. Blood, marrow, and thymus cells from normal individuals and patients with lymphoproliferative disorders were examined. Samples were fixed before exposure to specific reagents. Normal lymphocyts with detectable sIg, i.e. B lymphocytes, were characterized by a villous surface; nonlabeled blood lymphocytes and thymocytes were smooth cells. Intermediate cells were also found which in sections appeared moderately villous and labeled, thus identified as B lymphocytes. Further evidence for a relationship between villous surface and sIg was given by the finding of a few lymphocytes with polar concentration of labeled microvilli. In chronic lymphocytic leukemia patients, most cells exhibited a villous surface with parallel variations of the number of microvilli and of anti-immunoglobulin-binding capacity. However, some labeled smooth blastic cells were also observed. On the other hand, abnormal lymphocytes from Sézary's syndrome which could exhibit segments of villous membrane had no detectable sIg. This study confirms that in most cases human B lymphocytes have a characteristic surface appearance and that the detection of sIg in normal lymphocytes correlates with the presence of microvilli.

B-Lymphocytes↗
PubMed1975

[Application of the immunoperoxidase method to the study of the membrane of human lymphocytes].

Immunoelectron microscopy was applied to human lymphocytes exposed to purified peroxidase-conjugated anti-immunoglobulin. Indeed, detectable surface immunoglobulins are a salient feature of so-called " B " lymphocytes. On living cells, a rapid and massive internatization of the labelled membrane is observed. Prior glutaraldehyde cell fixation avoids such a phenomenon. Thus, exposure of fixed cells to conjugated anti-immunoglobulin allows the visualization of a dense and continuous specific membrane labelling. Immunoglobulin-bearing lymphocytes have a characteristic membrane surrounded with numerous microvilli. On the other hand, non-labelled lymphocytes have a smooth membrane. Intermediate forms are also noted among these extreme morphological features.

Adult↗
PubMed1975

[Immunoblastic sarcoma with autoimmune manifestations].

The authors report a new case of immunoblastic sarcoma with autoimmune manifestations. -- The early stages suggest a virus infection of this lymphoma: -- There is a hemolytic anemia which improves on chemotherapy, -- The pathological appearances are quite special, owing to the absence of malignant characteristics in the early stages of the disease and the difficulty of differentiating the tumour from a Hodgkin lymphoma. Various pathogenic theories are recalled.

Aged↗