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Biomedical subjects

A Messina

Publications and source records attributed to A Messina.

At least 109 records · Page 6Linked to original sources
PubMed1992

Transcription factor activation and functional stimulation of human monocytes.

Activation of expression of genes encoding transcription factors: c-fos and c-jun and formation of AP1 transcriptional complex in human monocytes was investigated. It was found that lipopolysaccharide induced strongly both c-fos and c-jun expression as well as AP1 formation. Interferon gamma activated strongly c-fos and weakly c-jun and AP1. Tumor necrosis factor induced slightly c-fos and had almost no effect on c-jun and AP1. The data suggest that differences in functional responses elicited in monocytes by all three factors may be dependent on different routes on nuclear signalling employed by the factors.

Gene Expression Regulation↗
PubMed1991

Quantitation of tyrosine hydroxylase and neuropeptide Y immunoreactivity in single rat sympathetic neurons: effects of preganglionic nerve activity.

Using computerised densitometry to measure immunocytochemical reaction product in a model system, we established conditions that produced a linear relationship between the logarithm of antigen concentration and the measured intensity of staining. We then applied the densitometric technique to assess the changes in tyrosine hydroxylase (TH) and neuropeptide tyrosine (NPY) within sympathetic neurons of rat superior cervical ganglion following chronic decentralization and following reserpine treatment. One week after surgical or pharmacological decentralization, there was appreciable reduction of neuronal levels of both TH and NPY. However, there remained considerable variation in the immunoreactivities of individual cells. Three days of treatment with reserpine elevated TH levels but substantially reduced NPY. Both these effects were prevented by prior decentralization of the ganglia. No differences were seen between normotensive and the Otago strain of genetically hypertensive rats, either in basal TH or NPY immunoreactivities or in responses to the maneuvers performed. Comparison of our findings with previous biochemical data indicate that densitometric immunocytochemistry provides an accurate index of neuronally localised antigen concentrations but also allows analysis of interneuronal differences that are not otherwise apparent.

Animals↗
PubMed1991

[Surgical treatment of congenital brachymetacarpus by dynamic elongation osteosynthesis. Report of a clinical case].

Dynamic elongation osteosynthesis is a new technique studied and applied by us in the treatment of congenital brachymetacarpal deformity. The anatomical, functional and aesthetic results of this operation in a young woman were excellent. We used a microtractor according to Ilizarov's in order to achieve methodology 22 mm of lengthening of the fourth metacarpal bone of the left hand. All soft tissue structures were elongated such as arteries, veins, nerves, intrinsic muscles, flexor and extensor tendons without any adverse effects. We therefore recommend this technique for the treatment of this congenital disease.

Adult↗
PubMed1991

Are genetically hypertensive rats deficient in nerve growth factor?

We have shown previously that sympathetic ganglia from genetically hypertensive Otago Wistar (GH) rats contain fewer neurons than those of normotensive animals and are heavily innervated by substance P-containing axons. In adult GH rats treated over days 1-7 of postnatal life with 10 micrograms/rat/day of nerve growth factor (NGF) s.c., ganglion cell numbers were similar to those of normotensive rats. By contrast, NGF treatment of neonatal normotensive animals did not affect ganglion cell numbers. In NGF-treated GH animals, the numbers of substance P-positive axons were substantially reduced relative to age-matched controls. We conclude that the abnormalities seen in ganglia of GH rats may involve a perinatal deficiency of a nerve growth factor.

Animals↗
PubMed1991

Nucleotide sequence of a human heart cDNA encoding the mitochondrial phosphate carrier.

We have isolated and characterized a full length cDNA clone encoding the precursor of the human heart mitochondrial phosphate carrier protein. The entire clone is 1330 bp in length with 5'- and 3'-untranslated regions of 48 and 184 bp, respectively. The open reading frame encodes the mature protein consisting of 312 amino acids, preceded by a presequence of 49 amino acids. The amino acid sequence of the mature human phosphate carrier is 93.6, 94.2 and 33.6% identical to that of the phosphate carrier from beef, rat and yeast, respectively. Like other mitochondrial transport proteins, the human phosphate carrier has a tripartite structure. Each of the three repeats contains two hydrophobic regions which presumably span the membrane in the form of alpha-helices.

Amino Acid Sequence↗
PubMed1990

Accumulation of ornithine decarboxylase mRNA accompanies activation of human and mouse monocytes/macrophages.

Accumulation of ornithine decarboxylase (ODC) mRNA was investigated in human monocytes and mouse peritoneal macrophages. Treatment of both populations of mononuclear phagocytes with bacterial lipopolysaccharide induced a marked and rapid increase in the accumulation of the ODC gene transcript. A similar phenomenon, albeit less pronounced, was also observed following treatment of human monocytes with human recombinant interferon-gamma. These results suggest a role for ODC, and therefore polyamines, in the regulation of mononuclear phagocyte functions.

Animals↗
PubMed1990

Human keratinocyte growth factor activity on proliferation and differentiation of human keratinocytes: differentiation response distinguishes KGF from EGF family.

Human keratinocyte growth factor (KGF) is an epithelial cell specific mitogen which is secreted by normal stromal fibroblasts. In the present studies, we demonstrate that KGF is as potent as EGF in stimulating proliferation of primary or secondary human keratinocytes in tissue culture. Exposure of KGF- or EGF-stimulated keratinocytes to 1.0 mM calcium, an inducer of differentiation, led to cessation of cell growth. However, immunologic analysis of early and late markers of terminal differentiation, K1 and filaggrin, respectively, revealed striking differences in keratinocytes propagated in the presence of these growth factors. With KGF, the differentiation response was associated with expression of both markers whereas their appearance was retarded or blocked by EGF. TGF alpha, which also interacts with the EGF receptor, gave a similar response to that observed with EGF. These findings functionally distinguish KGF from the EGF family and support the role of KGF in the normal proliferation and differentiation of human epithelial cells.

Biomarkers↗
PubMed1990

Glial fibrillary acidic protein messenger RNA and glutamine synthetase activity after nervous system injury.

The level of the mRNA for glial fibrillary acidic protein (GFAP), the major protein of the intermediate filaments of astroglial cells, and the activity of glutamine synthetase (GS), an enzyme selectively localized in astrocytes, were measured at different times after a unilateral mechanical lesion in the rat cerebral cortex. A rapid and early increase (6 hours post-lesion) in GFAP mRNA was observed; GFAP mRNA level reached a peak at 1-3 days and then decreased. Moreover, an astrocytic activation in cortical zones far from the injury site and in the contralateral hemisphere was detected. No change of GS activity was observed in the same model of brain injury, showing that this astroglial marker is not modified during the reactive gliosis obtained with this experimental model. GFAP mRNA has also been detected in the rat sciatic nerve; however, its level was not modified after nerve transection, suggesting a different regulation of GFAP expression in the peripheral nervous system.

Animals↗
PubMed1990

In vitro effects of puromycin aminonucleoside on the ultrastructure of rat glomerular podocytes.

Puromycin aminonucleoside (PAN)-induced nephrosis in rats provides a model for studying the pathogenesis of severe proteinuric conditions, such as minimal change disease. The present study used scanning (SEM) and transmission (TEM) electron microscopy to investigate the in vitro effects of PAN on rat glomerular podocytes. Slices of rat kidney were incubated for up to 3 days in Medium 199 with Hanks' salts (control) or in medium with PAN. Semiquantitative SEM analysis of glomeruli on the upper surface of kidney slices indicated that incubation with PAN (100 micrograms/ml and 500 micrograms/ml) decreased the number of microvilli on podocyte cell bodies (days 1, 2 and 3), increased the number of glomeruli showing flattening of podocyte cell bodies and major processes (days 2 and 3), and increased the number of glomeruli showing surface membrane blebbing on podocyte foot processes (day 3) (p less than 0.001 in all cases). TEM morphometry revealed that incubation with 500 micrograms/ml PAN retarded significantly (p less than 0.001 at days 2 and 3) the loss of podocyte foot processes observed in control cultures. Whilst the SEM changes to podocyte ultrastructure largely mimic those seen in PAN nephrosis in vivo, the retardation of foot process loss runs counter to the major TEM change observed in vivo.

Animals↗
PubMed1990

[Brief treatment with thymopentin as adjuvant in vaccination for hepatitis B: controlled study in patients on periodic hemodialysis].

Eleven hemodialysis patients (9 M, 2 F, aged 65 +/- 20 yrs) (Group A) were treated with thymopentin (TP-5) 50 mg as adjuvant therapy to HB vaccination, with 3 weekly administrations, the week before and the two following the first dose of Pasteur vaccine, 5 micrograms. The percentage of patients developing a sufficient antibody titer (20 mUI/ml) after 4 vaccine doses was not statistically different from that obtained among control groups B and C. The age- and sex- matched controls received the same vaccine schedule without adjuvant. The percentages were as follows: Group A 54.5%, Group B 63.6%, Group C 60%. No local or systemic side effects were encountered after the TP-5 administration. The authors suggest that a short TP-5 treatment as an adjuvant therapy to HB vaccination is not effective in patients maintained on hemodialysis.

Adjuvants, Immunologic↗
PubMed1990

Radial shortening with osteosynthesis in the treatment of Kienböck's disease.

Since 1970 we have been using an original method of epiphyseal osteotomy to produce radial shortening in the treatment of Kienböck's disease. This is based on the experience of treating unstable Colles fractures with 2 transcutaneous Kirschner wires; they consolidate easily and quickly. The advantages are: a radial dorsal approach and an operation which is easily performed; an increase in the vascularization induced in the proximal area of the lunate; reduction of immobilization to 3-4 weeks; absence of complications which are common in other methods; immobilization limited to the wrist alone; resumption of work after 6-8 weeks; radial shortening of 5-8 mm with effective dynamic and static unloading and better trophism of the lunate; regression of pain and recovery of prehensile power in the hand in 28 cases followed up for 5 to 16 years after surgery.

Adult↗
PubMed1989

Induction of protooncogene fos by extracellular signals in primary glial cell cultures.

In the present study various extracellular factors, acting through different second messenger systems, were examined for their capacity to increase the level of c-fos mRNA in primary glial cell cultures. In particular EGF, 12-O-tetradecanoylphorbol 13-acetate, the beta-adrenergic agonist isoproterenol, and the glutamate agonists, ibotenic and quisqualic acid, were studied. All the extracellular stimuli tested induced a rapid and transient increase in c-fos mRNA level in glial cell cultures regardless of the signal transduction pathway and the final effect on cell proliferation.

Animals↗
PubMed1989

Protamine sulphate-induced proteinuria: the roles of glomerular injury and depletion of polyanion.

It has been claimed that intrarenal injection of polycations results in proteinuria due to neutralization of glomerular basement membrane polyanionic charge without any glomerular morphological changes. To study the effects of polycation infusion on the renal glomerulus, the left kidney of rats was directly injected with protamine sulphate through the renal artery. Urine was collected from each kidney before and after injection, and protein excretion rates were determined. Ninety minutes after completion of the injection both kidneys were perfusion-fixed and the morphology and colloidal iron staining of the kidneys were studied by light and electron microscopy. Intrarenal injection of 0.5, 1, and 2 mg of protamine sulphate produced minimal or mild proteinuria in the majority of animals. Higher doses (5 mg) commonly resulted in decreased protein excretion associated with oliguria. Colloidal iron staining of glomerular polyanionic sites was undiminished when compared with control kidneys. Injection of protamine sulphate resulted in capillary thrombosis and severe damage to both glomerular and tubular epithelium in 6 of 16 kidneys. In the remaining kidneys, milder focal changes were apparent. Although its mechanism of action is unclear, it is apparent that protamine sulphate, even in small doses, is toxic to the cellular components of the glomerulus and tubules, thus accounting for the range of changes observed in renal function.

Animals↗
PubMed1989

Glomerular podocytes in cultured rat kidney slices. A qualitative and quantitative electron-microscopic study.

The ultrastructure of rat glomerular epithelial cells (podocytes) in kidney slices in vitro was examined using qualitative and quantitative electron microscopy. The kidney slices were cultured in Medium 199 with Hanks' salts in a 5% CO2/95% O2 environment for up to 14 days. Few changes in podocyte ultrastructure occurred in the first 12 h of culture, but by 24 h cell bodies were rounded, microvilli were present on all podocyte surfaces, and some foot processes had been replaced by flattened expanses of cytoplasm. These changes were more pronounced by 3 days, when some podocytes had developed pseudopodal extensions and appeared to be migrating from glomeruli onto the slice surface. Podocytes could still be identified after 8, 10 and 14 days of culture, although relatively few glomeruli remained at 14 days. Morphometric methods were used to analyse podocyte shape, volume and surface area during the first 4 days of culture. The most significant change involved loss of foot processes: the number of filtration slits per 100 microns of basement membrane decreased from 211.8 +/- 15.0 (mean +/- SD) at the commencement of culture, to 55.3 +/- 22.6 after 2 days (p less than 0.001). These data provide baseline information for in vitro studies on the effects of nephrotoxins on podocytes.

Animals↗
PubMed1989

[Clinical anatomo-pathologic and surgical considerations in type III central polysyndactylia of the hand (systemization and classification of lesions)].

Central polysyndactyly type III of the hands is a very rare and complicated malformation, since it shows a great number of anatomic and functional lesions. Seven persons belonging to an ethnic original group living in Trapani, in Western Sicily, have been the topic of a very deep and careful study; four of them have been operated on both sides. Our clinical research has allowed us to build up a Pedigree of the elements suffering from the malformation (showing autosomic dominant character) dating back to the beginning of the nineteenth century. The pedigree includes one hundred and fifteen persons of whom seventy healthy and forty five afflicted with central polysyndactyly type III. Numerous operative techniques have been used to face the anatomic, functional and aesthetic difficulties we have found.

Adolescent↗
PubMed1989

Correlation of the parameters of 24-hour growth hormone secretion with growth velocity in 93 children of varying height.

Growth velocity (cm/year) was studied in 93 prepubertal children of varying height and correlated with the parameters of 24-hour growth hormone (GH) secretion: maximum peak, integrated concentration (IC), number and amplitude of peaks. The group consisted of 74 boys and 19 girls whose mean age was 10 years 8 months. Fifty-five children had growth retardation (m = 2.8 SD), 22 were of normal height between +/- 2 SD and 12 had tall stature (m = 3.1 SD). Growth velocity for the group as a whole was 4.7 cm/year, 3.9 cm/year for the children with delayed growth, 4.6 cm/year for the normal children and 7.4 cm/year for the tall children. The study of 24-hour GH secretion for the group as a whole gave the following results: maximum peak 22.4 +/- 13.4 ng/ml, number of peaks 4.6 +/- 1.9 and IC 3.5 +/- 2 ng/ml. The multiple regression test showed a significant correlation (p less than 0.001) between growth velocity and the number of peaks during the night and over the 24-hour period. This correlation existed in all three groups, but was stronger in the group of tall stature than in the other two groups. However, no correlation was found between growth velocity, value of the maximum peak and integrated concentration in the group as a whole or in any of the three subgroups. These data show that the pulsatile nature of GH secretion is one of the factors most closely correlated with growth velocity, in children with growth retardation as well as in children of normal height and in tall children.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗