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M A Gallardo

Publications and source records attributed to M A Gallardo.

15 recordsLinked to original sources
PubMed2004

Na-dependent D-glucose transport by intestinal brush border membrane vesicles from gilthead sea bream (Sparus aurata).

Brush border membrane vesicles (BBMV) enriched in sucrase, maltase and alkaline phosphatase, and impoverished in Na(+)-K(+)-ATPase, were isolated from proximal and distal intestine of the gilthead sea bream (Sparus aurata) by a MgCl(2) precipitation method. Vesicles were suitable for the study of the characteristics of D-glucose apical transport. Only one D-glucose carrier was found in vesicles from each intestinal segment. In both cases, the D-glucose transport system was sodium-dependent, phlorizin-sensitive, significantly inhibited by D-glucose, D-galactose, alpha-methyl-D-glucose, 3-O-methyl-D-glucose and 2-deoxy-D-glucose, and showed stereospecificity. Apparent affinity constants of D-glucose transport (K(t)) were 0.24 +/- 0.03 mM in proximal and 0.18 +/- 0.03 mM in distal intestine. Maximal rate of influx (Jmax) was 47.3 +/- 2.2 pmols. mg(-1) protein for proximal and 27.3 +/- 3.6 pmols. mg(-1) protein for distal intestine. Specific phlorizin binding and relative abundance of an anti-SGLT1 reactive protein were significantly higher in proximal than in distal BBMV. These results suggest the presence of the same D-glucose transporter along the intestine, with a higher density in the proximal portion. This transporter is compatible with the sodium-dependent D-glucose carrier described for other fish and with the SGLT1 of higher vertebrates.

Animals↗
PubMed2000

Cutaneous cryptococcosis in two patients with acquired immunodeficiency syndrome.

We present 2 cases of systemic cryptococcosis with cutaneous involvement in patients with acquired immunodeficiency syndrome (AIDS). Both patients were male, intravenous drug abusers, 31 and 35 years old, with severe immunodepression and a CD4+ lymphocyte count of 10/ml and 1/ml, respectively. They both had papular lesions reminiscent of molluscum contagiosum and in one patient with concomitant systemic leishmaniasis, there were spores of Cryptococcus neoformans coexisting with the leishmanias in the cutaneous lesions, constituting the first reported case of this particular association. Both patients responded well to amphotericin B followed by fluconazole.

AIDS-Related Opportunistic Infections↗
PubMed1999

Squamous cell carcinoma secondary to recessive dystrophic epidermolysis bullosa: report of eight tumours in four patients.

BACKGROUND: The development of squamous cell carcinomas is the main cause of death of patients with Dystrophic epidermolysis bullosa. We think it is of interest to know their clinical characteristics and the treatment difficulties they cause. METHODS: We followed the clinical evolutions and carried out histopathological studies of eight primary cutaneous squamous cell carcinomas on three males and one female with recessive dystrophic epidermolysis bullosa. Patient ages ranged from 16 to 34 years (mean 27). RESULTS: Two patients had two tumours and one three, all were in characteristically scarred skin; four on upper limbs; four on lower. Maximum tumour dimensions ranged from 2 to 28 cm (mean 13), and represented 6 or more months of evolution. In three cases the affected limb must be amputated. Five tumours were well differentiated, three were moderately differentiated. CONCLUSIONS: The patients consulted too late and their large lesions needed aggressive treatment. Appropriate information and regular examination of patients with RDEB helps early diagnosis of tumours and may avoid disabling operations.

Adolescent↗
PubMed1997

Influence of hypo-osmolality on the activity of short-chain neutral amino acid carriers in trout (Salmo trutta) red blood cells.

The present study shows that in trout red blood cells the activity of some amino acid carriers, not directly involved in cell volume regulation, is affected by external osmolality. Glycine uptake has been used as the experimental approach because it was shown previously that it is effected by different carriers, namely the Na+-dependent ASC and Gly systems, as well as the Na+-independent asc and L systems. An increase in the uptake through the Gly system and the two Na+-independent carriers was found, while the ASC system appeared to be downregulated. Those systems whose activities were increased by hypo-osmolality did not share the mechanism by which this increase was obtained. Thus, the Gly system was sensitive to intracellular ionic changes, while the Na+- independent systems were mechanically stimulated, as assessed by the iso-osmotic swelling caused by ammonium chloride. On the other hand, a volume-sensitive transporter may be present in trout red blood cells, which is involved in the swelling-induced glycine movement, as can be deduced from the effect of some inhibitors such as pyridoxal phosphate, DIDS (4,4'-diisothiocyanate-stilbene-2,2'-disulfonic acid) and quinine.

Animals↗
PubMed1997

L-alanine uptake by frog (Rana esculenta) red blood cells.

L-Alanine uptake has been studied in frog red blood cells. The present study shows the presence of different carriers for this amino acid in these cells. In the physiological concentration range, most L-alanine is taken up through the Na(+)-dependent system ASC, although the sodium-independent systems asc and L are also active. The competitive inhibition data obtained makes difficult to differentiate the two Na(+)-independent activities in a clear contrast with data from fish or mammalian erythrocytes, indicating that despite its widespread occurrence in vertebrates, these carriers show characteristics that are species specific.

Alanine↗
PubMed1997

Seasonal variation in uptake of short-chain neutral amino acid by red blood cells and hepatocytes in trout (Salmo trutta).

The present study shows that the capacity of trout (Salmo trutta) red blood cells (RBCs) and freshly isolated hepatocytes to take up short-chain neutral amino acids changes according to a seasonal pattern. Maximal amino acid uptake rates in RBCs were obtained in winter and spring, while minima were seen in summer and autumn. In contrast, the maximal rates for the freshly isolated hepatocytes were obtained in autumn and winter, and the minima were seen in spring and summer. In addition, by studying the uptake of glycine, evidence was found that the activities of the amino acids carriers ASC, asc and Gly in RBCs varied according to a seasonal rhythm. The activity of the ASC and asc systems changed in parallel with the global uptake of amino acids. Moreover, the RBC:plasma concentration ratio for certain substrates of these carriers (alanine, serine and glycine) varied accordingly. In contrast, the activity of the Gly system was modified inversely with respect to the overall amino acid uptake. The activity of the ASC system in freshly isolated hepatocytes was also seasonally modified, reaching a maximum in autumn, shortly before the reproductive period.

Amino Acids↗
PubMed1996

Uptake of L-leucine by trout red blood cells and peripheral lymphocytes.

The uptake of l-leucine by trout red blood cells and peripheral lymphocytes has been analyzed. The present study shows two functionally different Na+-independent systems for apolar branched-chain amino acids. They are designated as L systems because they share some properties with the mammalian L system. The carrier present in red blood cells has low Km values, is trans-stimulable and not stereospecific for leucine uptake; on the other hand, the system present in lymphocytes is stereospecific for leucine uptake and trans-inhibitable. Both carriers are pH sensitive in a similar fashion at low pHs, but there are important differences at higher pH values (above neutrality). These properties are compared with these of the asc systems previously reported in these cells.

Animals↗
PubMed1996

Bacillary angiomatosis in an HIV seronegative patient on systemic steroid therapy.

Bacillary angiomatosis is an unusual systemic vascular proliferation seen predominantly in patients with the acquired immunodeficiency syndrome. These vascular lesions are due to infection with a Bartonella species, most commonly B. henselae, but sometimes B. quintana. It is treatable and often curable, but without therapy may be life-threatening. Clinically, the disorder often resembles several different vascular disorders, particularly pyogenic granuloma and Kaposi's sarcoma. We now report a clinically typical patient with bacillary angiomatosis who was HIV seronegative, but who had idiopathic thrombocytopenic purpura, was status-post splenectomy and to whom long-term systemic prednisone had been administered.

Adult↗
PubMed1994

Presence of X-AG carrier in frog (Rana esculenta) red blood cells.

Evidence is presented that the high levels of internal L-glutamic and L-aspartic acid in frog (Rana esculenta) red blood cells are due to the existence of a specific carrier for acidic amino acids of high affinity (Km = 3 microM) and low capacity (Vmax 0.4 mumol L-Glu.Kg-1 dry cell mass.10 min-1). It is Na+ dependent and the incorporation of L-glutamic acid can be inhibited by L- and D-aspartate and L-cysteic acid, while D-glutamic does not inhibit. Moreover, this glutamic uptake shows a bell-shaped dependence on the external pH. All these properties show that this carrier belongs to the system X-AG family. Besides the incorporation through this system, L-glutamic acid is also taken up through the ASC system, although, under physiological conditions, this transport is far less important, since it has relatively low affinity (Km 39 microM) but high capacity (Vmax 1.8 mumol L-Glu.Kg-1 dry cell mass.10 min-1).

Amino Acid Transport System X-AG↗
PubMed1994

Na(+)-independent L-alanine uptake by trout cells. Evidence for the existence of at least two functionally different acs systems.

The Na(+)-independent uptake of L-alanine has been studied in trout red blood cells, isolated hepatocytes and peripheral blood lymphocytes. The present study shows the existence of two functionally different Na(+)-independent systems for short chain neutral amino acids in these cells. They are designated as asc systems because of their resemblance to systems described in other cell types. Besides their independence of sodium and a rough similarity in substrate preference, the most important property shared by the two carriers is a lack of trans-stimulation, allowing further differentiation from system L. One of them is an unusually stereospecific carrier present in red blood cells, the other is less restrictive and present in hepatocytes and peripheral blood lymphocytes. Extracellular acid pH increases the incorporation to red blood cells, while it slightly depresses the uptake in the other cells. From the data presented, it is not possible, at first, to classify these carriers as asc1 or asc2 systems. Moreover, the system present in red cells resembles that found in the nonerythroid cells, BSC-1, while there is no clear parallelism between the system found in hepatocytes/lymphocytes and any of those described previously.

Alanine↗
PubMed1993

Glycine uptake by trout (Salmo trutta) red blood cells.

The present study demonstrates the presence of different amino acid carriers in the membrane of trout red cells. Most glycine is taken up through the Na(+)-dependent system ASC, although the nearly specific Gly system is also active. Besides these carriers, glycine is taken up by means of Na(+)-independent transporters, system L being the most important. A system asc of high affinity and low capacity has been found, and band 3 is unable to transport glycine under physiological conditions. These results suggest that although all these carriers are already present in primitive vertebrates, several differences exist in their properties with respect to those found in mammalian cells.

4-Acetamido-4'-isothiocyanatostilbene-2,2'-disulfo↗
PubMed1992

Glucose metabolism by trout (Salmo trutta) red blood cells.

Glucose metabolism has been studied in Salmo trutta red blood cells. From non-metabolizable analogue (3-O-methyl glucose and L-glucose) uptake experiments it is concluded that there is no counterpart to the membrane transport system for glucose found in mammalian red blood cells. Once within the cells, glucose is directed to CO2 and lactate formation through both the Embden-Meyerhoff and hexose monophosphate shunts; lactate appears as the most important end-product of glucose metabolism in these cells. From experiments under anaerobic conditions, and in the presence of an inhibitor of pyruvate transfer to mitochondria, most of the CO2 formed appears to derive from the hexose monophosphate pathway. Appreciable O2 consumption has been detected, but there is no clear relationship between this and substrate metabolism. Key enzymes of glucose metabolism, hexokinase, fructose-6-phosphate kinase and, probably, pyruvate kinase are out of equilibrium, confirming their regulatory activity in Salmo trutta red blood cells. The presence of isoproterenol, a catecholamine analogue, induces important changes in glucose metabolism under both aerobic and anaerobic conditions, and increases the production of both CO2 and lactate. From the data presented, glucose appears to be the major fuel for Salmo trutta red blood cells, showing a slightly different pattern of glucose metabolism from rainbow trout red blood cells.

3-O-Methylglucose↗
PubMedDate not supplied

Angiosarcoma arising on rhinophyma.

We report an 82-year-old man who presented with a tumor which had developed over the previous year on the right nasal ala of a rhinophyma. Histopathological, immunohistochemical, and electron microscopic study confirmed the diagnosis of angiosarcoma on the head and neck. He was treated with radiotherapy of the tumor and cervical adenopathy, which developed later. The possible etiological and pathogenetic role of lymphedema due to inflammatory flares of rosacea on the nose is discussed, together with the histological and immunohistochemical data leading to the diagnosis of this tumor.

Aged↗