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Biomedical subjects

G Scala

Publications and source records attributed to G Scala.

At least 55 records · Page 3Linked to original sources
PubMed1991

[The sensitive nerve endings of the clitoris of the sow (Sus scrofa domesticus)].

Neural receptors of the porcine clitoris were examined using light and electron microscopy. Perfusion with ink allowed study of the unique vascular arrangement associated with the genital corpuscles. Sensory nerve-endings were generally rounded and formed a morphologically and structurally characteristic unit. They were composed of a network of primarily non-myelinated nerve fibers and flat cells. Between these structures, isolated small blood vessels were embedded amongst collagen fibers and amorphous material. An external capsule of variable thickness always surrounded the structures. A complex arrangement of vessels in the center of the capsule was formed by a subpapillary mesh. The same arrangement was seen in the morphologically comparable penile genital corpuscles of the same species. Based on the particular arrangement of blood vessels and nerve fibers in the genital corpuscles, some authors postulate the presence of a neuro-vascular glomerulus.

Animals↗
PubMed1991

[The structure of the clavicular air sac of the duck (Anas platyrhinchos)].

The structural organization of the epithelium lining the clavicular air sac in Duck was studied by light and electron microscopic. This epithelium consists of two types of pavement like cells. The first flat types of cells are numerous with large mitochondria containing cytoplasm and elongated nuclei. The second short and dumpy cells are few in number and are after seen near the ostium. They could have long microvilli like pseudopod on their apical surface ready to engulf inhaled foreign particles. Desmosomal bridges too are found between contiguous cells.

Air Sacs↗
PubMed1991

[SEM study on the mucosa of the pre-stomach in Bubalus buffalus].

Morpho-structural features of pre-stomach mucosa in the first period of post-natal life in Bubalus buffalus have been studied by SEM. The rumen presents a well defined morpho-structural architecture from 10 to 100 days of life, while in reticulum and in omasum numerous morphological variations have been noticed. During the development, in fact, in these organs the establishment of a typical morphological pattern has been observed.

Animals↗
PubMed1990

Expression of an exogenous interleukin 6 gene in human Epstein Barr virus B cells confers growth advantage and in vivo tumorigenicity.

The biological role of interleukin 6 (IL-6) molecules in human B cell tumorigenesis was studied by using an episomal expression vector, pHEBoSV-IL6, to introduce stably the human IL-6 gene into human Epstein Barr virus (EBV)-transformed B lymphoblasts. The gene was present in the IL-6-transfected cells in a high copy number and was efficiently expressed, resulting in the secretion of consistent levels of IL-6 molecules. The constitutive expression of the IL-6 gene led to an altered pattern of growth and to a malignant phenotype, as shown by clonogenicity in to an altered pattern of growth and to a malignant phenotype, as shown by clonogenicity in soft agar cultures and tumorigenicity in nude mice. These data suggest that the combined action of EBV, which exerts an immortalizing function, and of the growth-promoting activity of IL-6 molecules, can give rise to fully transformed B cell tumors in immunodeficient subjects.

Animals↗
PubMed1990

Immunosuppressive activity of bovine seminal RNase on T-cell proliferation.

The interest in the immunosuppressive activity of mammalian seminal plasma depends largely on its putative role in the immunoregulation of both the male and female genital systems. We report here that the immunosuppressive action of bovine seminal plasma is based on the presence in this fluid of copious amounts of an immunosuppressive RNase, bovine seminal RNase. Studies of structure-function relationships have revealed that the immunosuppressive activity of seminal RNase depends on the integrity of the dimeric structure of the enzyme, as well as on the integrity of its catalytic function. While bovine seminal RNase has no effect on the secretion of interleukin-2 by T-cell cultures, the enzyme has been found to decrease drastically the expression of the alpha-chain of the interleukin-2 receptor on the T-cell membrane.

CD3 Complex↗
PubMed1990

[The structure of the syrinx in the duck (Anas platyrhinchos)].

The morphological and structural aspects of the Membrana tympaniformis medialis of the syrinx were studied with L.M. and E.M. in 32 female and male Peking ducks from 6 to 12 months old. The membrane is covered by pseudostratified prismatic epithelium which shows different regional features. While at level of the proximal and distal third of the tympanic membrane the morphological and structural aspects of the cells resemble that of the adjacent structures (pessulus and primary bronchi), the middle part of the epithelium layer becomes gradually flattered; the epithelium is made up of oblique or horizontal cells which touch each other by means of many lateral interdigitations. At level of the upper parts of the cells there are several types of cell junctions. This particular disposition seem to be well adapted to the contractions of the syringeal muscles.

Animals↗
PubMed1990

Comparison of low rate dual chamber pacing to activity responsive rate variable ventricular pacing.

A study was undertaken to evaluate exercise performance in 18 dual chamber pacemaker patients believed to be chronotropically incompetent. All patients were paced in a DDD AV synchronous mode at 80 beats per minute (beats/min) as well as an externally triggered, activity responsive VVIR mode. Patients underwent two single blind, randomized symptom-limited treadmill tests (Sheffield protocol). Four of the 18 patients achieved intrinsic rates greater than 100 beats/min and were deleted from the primary study. It was noted that all four of these patients performed best with intrinsic rate response and AV synchrony. Thirteen of the remaining 14 patients demonstrated improved exercise tolerance in the VVIR mode. Average exercise time in the VVIR mode (7:25 +/- 3:12 min) was significantly greater (P less than 0.05) than the DDD mode (6:01 +/- 2:27 min). Work performed was significantly greater (P less than 0.05) in the VVIR mode (4.77 +/- 1.97 METS) than in the DDD mode (3.78 +/- 0.77 METS). Maximum heart rates were 83.86 +/- 5.11 beats/min in DDD mode versus 116.00 +/- 10.56 beats/min in VVIR mode. The results demonstrated that improved exercise tolerance can be achieved with single chamber rate variable pacing compared to DDD pacing in patients with chronotropic incompetence. However, potential symptoms associated with loss of AV synchrony should be ruled out.

Adult↗
PubMed1990

Interleukin-1-beta modulation of prolactin secretion from rat anterior pituitary cells: involvement of adenylate cyclase activity and calcium mobilization.

Recent findings indicate that interleukin-1 beta (IL1 beta), a monokine secreted by stimulated macrophages and monocytes, modulates neuroendocrine functions in a manner similar to classical hormones. In this study we show that IL1 modulates PRL secretion, assessed by reverse hemolytic plaque assay, and describe the effect of the monokine on adenylate cyclase activity and calcium fluxes in rat normal pituitary cells. In basal and vasoactive intestinal peptide (VIP)-stimulated conditions, low doses of IL1 reduced the mean plaque area, a direct index of PRL secretion without affecting the percentage of PRL-secreting cells. Similarly, low concentrations of IL1 inhibited adenylate cyclase activity in both basal and VIP-stimulated conditions, while higher concentrations restored the enzymatic activity to the control value. IL1 also caused a biphasic effect on the free intracellular calcium increase induced by maitotoxin, a calcium channel activator, being inhibitory at low and stimulatory at high concentrations. The effects of IL1 on adenylate cyclase activity and calcium fluxes were reversed by preincubation of the monokine with its polyclonal antibody, thus confirming the specificity of the effects. In conclusion, our data show that IL1 modulates PRL secretion by acting directly on pituitary cells through interaction with the adenylate cyclase-cAMP system and calcium flux.

Adenylyl Cyclases↗
PubMed1989

The vascularization of the Bursa cloacalis (of Fabricius) in the duck.

The morphological and structural features of the vascular component of the bursa of Fabricius in the duck are described. By means of an intravasal perfusion of suitably colored neoprene Latex or Microscopaque, or a perfusion of Indian ink, it was possible to follow visually the routes of arteries, veins and the microcirculation; this last represents a major characteristic of the bursal follicle in the duck. The microcirculation has its origins in several roots arising from the follicular arterioles, which in the region of the cortex constitute an open vascular layer. From these pre-capillary arterioles, adjacent to the limiting layer between cortex and medulla, a dense capillary network is formed. With the aid of an electron microscope the presence of a cortico-medullary barrier of an epithelio-reticular nature was revealed; close to it there are the terminal branches of the intrafollicular network. The barrier appears to be structurally more compact than that of the cortical capillaries of the mammalian thymus.

Animals↗
PubMed1989

[Morphostructural features of the pleural lymphatic circulation in the pig].

The morphostructural features of the lymphatic circle of swine visceral pleura were investigated by means of vital dye injection in the pleural cavity. In the animals treated as mentioned previously it was possible to observe that in the visceral pleura the superficial lymphatic network had formed the very thick mesh, while the underlying pulmonary parenchyma was not interested. This behaviour lets us suppose that the drainage of the visceral pleura is mainly a direct one.

Animals↗
PubMed1988

Effect of interleukin 1 beta on transducing mechanisms in 235-1 clonal pituitary cells. Part I: Modulation of adenylate cyclase activity.

In the present study we evaluated the effect of interleukin 1-beta on adenylate cyclase activity in 235-1 pituitary cell line. The dose-response curve of interleukin 1 beta effect on adenylate cyclase activity showed a significant inhibition of basal enzyme activity at 1 pM concentration, while the inhibition of forskolin stimulated adenylate cyclase activity was more pronounced and evident at both 0.01 and 1 pM concentrations. The action of the monokine on basal enzyme activity was almost completely reverted by polyclonal anti interleukin 1 beta antibody. The incubation of the cells for 48h with interleukin 1 beta showed a different pattern of response. The inhibitory effect of interleukin 1 beta on adenylate cyclase activity disappeared, while the highest concentration of interleukin 1 beta tested, caused a meaningful stimulation of adenylate cyclase activity which is not present in acute condition. These data show that interleukin 1-beta interacts with the cAMP-generating system in the 235-1 clonal pituitary cells.

Adenylyl Cyclases↗
PubMed1988

Effect of interleukin 1 beta on transducing mechanisms in 235-1 clonal pituitary cells. Part II: Modulation of calcium fluxes.

In the present study we investigated the effect of the interleukin 1 beta on intracellular free calcium concentrations in 235-1 cell line both in basal conditions and after stimulation by the calcium channel activator maitotoxin. Interleukin 1 beta (from 0.01 pM to 10 nM) was unable to significantly affect basal cytosolic free calcium levels in acute conditions. The preincubation of these cells with interleukin 1 beta for 48h modulates maitotoxin stimulation of calcium fluxes without modifying basal intracellular free calcium levels. Low concentrations of interleukin 1 beta (0.01 pM, 1 pM) caused a marked reduction of intracellular free calcium concentrations increase induced by maitotoxin while higher doses of the monokine potentiated maitotoxin stimulation of calcium fluxes. The specificity of interleukin 1 beta effect was tested by means of polyclonal anti-interleukin 1 beta antibody (titer 1:100) which significantly abolished the inhibitory effect of interleukin 1 beta on free cytosolic calcium levels. These results show that a long lasting interaction of interleukin 1 beta with its receptor is able to influence voltage-sensitive calcium channels activation induced by maitotoxin in 235-1 cells.

Animals↗
PubMed1988

Decreased interleukin-1 production in aplastic anemia.

PURPOSE: Interleukin-1 (IL-1), a monocyte factor, plays a central role in the regulation of the immune response; recent data have suggested that IL-1 is the same molecule as hemopoietin-1, a growth factor acting on the multipotent hematopoietic stem cell. IL-1 affects hematopoiesis (1) in vitro, by inducing the release of colony-stimulating factors and regulating early hematopoietic progenitor cells, and (2) in vivo, by stimulating stem cell recovery in irradiated or chemotherapy-treated mice. Several lines of evidence suggest that aplastic anemia may be mediated by cells of the immune system. We address the issue of abnormal IL-1 production in severe aplastic anemia and attempt to correlate normalization of the levels with response to anti-thymocyte globulin (ATG) therapy. PATIENTS AND METHODS: We studied IL-1 production by monocytes from 21 patients with aplastic anemia using a bioassay for IL-1 activity. Fifteen patients were evaluated before ATG therapy. Eight patients were studied before and three months after ATG. In addition, five patients were evaluated only after ATG treatment. One patient did not respond to ATG but did respond to intravenous acyclovir, and was studied before and after acyclovir therapy. Twenty patients with other hematologic disorders requiring transfusions and 30 normal healthy volunteers were also assessed. RESULTS: IL-1 production was markedly decreased in 75 percent of patients with aplastic anemia when compared with that in normal control subjects (p less than 0.005). Hematologic recovery correlated with normalization of IL-1 production in all but two cases (p less than 0.04). CONCLUSION: These observations represent the first evidence of monocyte dysfunction and deficient hematopoietic growth factor production in aplastic anemia. Decreased IL-1 production may have a pathologic role in some cases of aplastic anemia.

Adult↗
PubMed1988

Heterogeneity in the mitogenic response of peripheral blood mononuclear cells to a pan T monoclonal antibody.

Peripheral blood mononuclear cells (PBMC) from 80 normal donors were studied for their capacity to proliferate in response to Pan T2, an IgG1 monoclonal antibody (MoAb), that recognizes the CD3 complex. Forty percent of this population, regardless of sex or age, were found to be non-responders. However, the binding of MoAb Pan T2 to T cells as studied by indirect immunofluorescence was positive in all the donors. The addition of IL 1 or IL 2 to Pan T2-stimulated non-responder lymphocytes did not activate T cell proliferation, while the addition of responder monocytes restored the proliferation capacity in non-responder PBMC. The data indicate the existence of a heterogeneous responsiveness among normal individuals to a mitogenic IgG1 MoAb, and are in agreement with reports obtained using other anti-T3 MoAbs of IgG1 isotype, i.e. UCHT1, Leu4 and WT31. This defect is reported to be a function of monocytes, related to a polymorphism of Fc receptors for mouse IgG1 on human monocytic cells.

Antibodies, Monoclonal↗
PubMed1987

Expression of interleukins in L cells transfected with human DNA.

We have obtained, by transfection of mouse L cells with total human DNA, clones that constitutively secreted human interleukins IL1, IL2 and B-cell grown-factor activities, as assessed by specific biological assays. Southern analysis with IL2 and IL1 beta cDNAs confirmed the integration of the corresponding human genes in the genome of recipient mouse cells and showed their amplification and rearrangement. All the four IL2-secreting clones integrated in the mouse genome the human IL2 gene. Three out of the sixteen IL1-producing clones contained the IL1 beta gene. The IL1 activity secreted by the remaining clones exhibited a molecular mass of 17 kDa similar to that reported for mature human macrophage IL1. Our results demonstrate that DNA-mediated gene transfer may represent a suitable tool for the production of human growth and differentiation factors and the cloning of their genes.

Animals↗