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Biomedical subjects

A Serrano

Publications and source records attributed to A Serrano.

At least 109 records · Page 6Linked to original sources
PubMed1995

Characterization of muscle glyceraldehyde-3-phosphate dehydrogenase isoforms from euthermic and induced hibernating Jaculus orientalis.

The specific activity of D-glyceraldehyde-3-phosphate (G3P) dehydrogenase (phosphorylating) (GPDH, EC 1.2.1.12) found in skeletal muscle of induced hibernating jerboa (Jaculus orientalis) was 3-4-fold lower than in the euthermic animal. The comparative analysis of the soluble protein fraction of these tissues by SDS-PAGE and Western blotting showed a significant decrease in the intensity of a protein band of about 36 kDa, the GPDH subunit, in hibernating jerboa. After using the same purification procedure, the GPDH from muscle of hibernating jerboa exhibited lower values for both apparent optimal temperature and specific activity than the enzyme from the euthermic animal. Non-linear Arrhenius plots were obtained in both cases, but the Ea values calculated for the GPDH from hibernating tissue were higher. Although in both purified enzyme preparations three isoelectric GPDH isoforms, exhibiting pI values in the range 8.2-7.5, were resolved by chromatofocusing, clear differences were observed in these preparations concerning the relative contribution to the total enzymatic activity of the two main isoforms, named GPDH I (pI values, 8.1-8.2) and GPDH II (pI values, 7.8-7.9). Thus, whereas GPDH I was the major isoform purified from euthermic muscle, accounting for more than 90% of the total activity, the amount of activity due to GPDH II reached up to 65% in preparations of hibernating jerboa. All isoforms exhibited similar native and subunit molecular masses and cross-reacted with an anti-GPDH antibody raised against the GPDH I. However, the two muscle GPDH isoforms prevailing under hibernating conditions exhibited a decreased catalytic efficiency when compared with the corresponding major isoforms purified from euthermic animals, as indicated by their different specific activities and kinetic parameters, i.e. relatively high Km and low Vmax values. Since the glycolytic flow has been found to be widely reduced in skeletal muscle of induced hibernating jerboa, the changes in the GPDH isoforms described in the present study could provide a molecular basis to explain some of the metabolic changes associated with mammalian hibernation.

Animals↗
PubMed1995

Surgical treatment of childhood mediastinal tuberculous lymphadenitis.

Between 1985 and 1991, we treated 6 children, aged 2 months to 3 years, who required an invasive procedure for the management of complications caused by enlarged mediastinal lymph nodes secondary to tuberculosis. Radiologic and endoscopic studies revealed bronchial involvement by lymph nodes, with endobronchial granulomas and lobar or pulmonary obstruction in 4 patients and marked tracheal and esophageal stenosis produced by extrinsic compression in the remaining 2. Pathologic study of the lymph node or bronchial samples from the 6 patients disclosed granulomas with caseous necrosis and Langhans' giant cells. All the children were treated with a standard 6-month drug regimen consisting of isoniazid, rifampicin, and pyrazinamide. Five of the patients underwent thoracotomy for the purpose of nodal curettage or excision. In 1, upper right lobectomy and bronchoplasty were necessary. The sixth patient was treated by endoscopic resection of the granulomas. There was no postoperative morbidity, and radiologic and endoscopic evidence of resolution of the lesions was observed in all the patients. In our experience, surgical treatment, when performed as a coadjuvant treatment for tracheobronchial complications stemming from mediastinal tuberculous lymphadenitis, results in the resolution of the lesions and has no related morbidity.

Bronchoscopy↗
PubMed1995

Differential MAGE-1 gene expression in two variants of an erythroleukemic cell line (K562).

The MAGE-1 gene encodes an antigen recognized on melanoma cells by autologous cytotoxic T cells. This gene shows a wide range of expression in many human tumors but not in normal tissues except for testes. We used reverse transcription polymerase chain reaction assays to analyze the expression of the MAGE-1 gene in two variants of an erythroleukemic cell line, K562. Comparison of two variants of the K562 cell line in different stages of differentiation showed different patterns of expression of the MAGE-1 gene. The more undifferentiated cell line (K562A) expressed high levels of specific MAGE-1 mRNA, in contrast to K562B, which features of erythroid differentiation, without MAGE-1 expression. Interestingly, we could not modulate MAGE-1 gene expression when in vitro differentiation of K562A was induced with Ara-C. Finally, our data indicate that MAGE-1 expression is not necessary for the maintenance of the transformed phenotype.

Antigens, Neoplasm↗
PubMed1995

Thumb reconstruction with extended twisted toe flap.

Twelve amputated thumbs were reconstructed with a neurovascular cutaneous flap from the great toe and an osteotendinous flap from the second toe. Both transfers were dependent on a single vascular pedicle. One of the 12 reconstructions failed. In the remaining 11, the mobility of the metacarpophalangeal joint ranged from 10 degrees to 50 degrees, and that of the interphalangeal joint from 10 degrees to 30 degrees. Opposition and key pinch were restored, and the shape and volume were similar to those of the normal thumb. Likewise, the great toe was preserved, and all patients had a normal gait. This technique preserves the epiphyses for future growth in children and maintains the aesthetic appearance of the foot, but it has the disadvantage of involving a lengthy surgical procedure with a 17% rate of major complications.

Adolescent↗
PubMed1994

Origin and evolution of binucleate cells in cultures of HEp-2 cells.

The origin and evolution of binucleate cells in cultures of HEp-2 cells have been studied by means of interval photography and time-lapse video-recording. Binucleate cells most frequently formed by the fusion of two sister cells born in a previous mitosis. The study of binucleate cells has shown that they are a cellular type able to successfully undergo mitosis. However, the mitosis may be bipolar, tripolar or multipolar. The daughter cells arising from these divisions do not follow a clear pattern in the number of nuclei they have, instead showing a wide range of possibilities.

Carcinoma↗
PubMed1994

[Myxoma of the left atrium presenting as repeated cerebrovascular disorders].

Infarction of the central nervous system secondary to embolism from a left atrial myxoma is a recognized phenomenon. However, a myxoma as the source of an embolus may be overlooked, if, during the evaluation of a patient with a stroke of unknown etiology, an index of suspicion is not present. We report a case of a 57-year old woman presenting three episodes of cerebral infarction always in the same brain territory, suggesting a carotid pathology. The physical examination of the patient only showed a loud S1 with no other sounds and neurologic alterations, namely, right hemiparesia and aphasia. Diagnosis was made by two-dimensional echocardiography and better delineation was obtained by magnetic resonance imaging (MRI). The patient subsequently received a successful ressection of the myxoma. Eighteen months later the patient was well.

Cerebrovascular Disorders↗
PubMed1994

Two distinct NAD(P)H-dependent redox enzymes isolated from onion root plasma membranes.

Plasma membranes purified by two-phase partition from onion roots catalyzed the NAD(P)H-dependent reduction of a variety of electron acceptor such as ferricyanide, quinones, dyes and ascorbate free radical. Among these, NAD(P)H-ferricyanide and -quinone oxidoreductase activities were effectively solubilized by Triton X-100. Both oxidoreductase activities were bound to an affinity column of Blue-Sepharose CL 6B. NADH eluted a redox enzyme showing more juglone than ferricyanide-dependent activity. Ulterior unspecific elution with salt allowed us to the partial purification of a different redox enzyme of about 31 kDa that reduced better ferricyanide than quinones and constituted the bulk of solubilized redox activity.

Allium↗
PubMed1993

ATP-driven transhydrogenation and ionization of water in a reconstituted glyceraldehyde-3-phosphate dehydrogenases (phosphorylating and non-phosphorylating) model system.

In an unbuffered medium, an intense acidification occurs during the oxidation of D-glyceraldehyde-3-phosphate (G3P) to 3-phospho-D-glycerate (PGA) catalyzed by NADP(+)-specific non-phosphorylating G3P dehydrogenase, an enzyme that photosynthetic eukaryotic cells contain exclusively in their cytosol. The true enzymatic character of this proton release is the consequence of the following redox/acid-base reaction: G3P + NADP+ + H2O-->PGA + NADPH + 2H+. When the well-established ATP-dependent reduction of PGA to G3P, catalyzed by PGA kinase and NAD(+)-specific phosphorylating G3P dehydrogenase, was coupled through the intermediate G3P to the above reverse oxidation reaction, a transient alkalinization of the medium followed by its acidification accompanied transhydrogenation from NADH to NADP+. The significance of the observed endergonic transhydrogenation and ionization of water at the expense of the chemical energy of ATP in this reconstituted enzyme system as well as its relevance for the export of reducing power (H-) across the chloroplast membrane and the maintenance of the pH gradient that exists between the stroma and the cytosol are discussed.

Adenosine Triphosphate↗
PubMed1993

Biochemical and histological alterations induced by fluid percussion brain injury in the rat.

In the present study we have characterized the time-course of the histopathological and biochemical alterations resulting from mechanical brain injury caused by lateral fluid percussion centered over the parietal cortex in the rat. The injury device used was an HPLC pump coupled to a solenoid valve which delivered a constant and short lasting (10 ms) impact pressure (1.6 atm). This traumatic procedure resulted in an accumulation of blood in the subarachnoid space and cortical edema at 4-24 h post-trauma. From 4 h after injury, cortical neurons exhibited a pathologic appearance and phagocytic cells invaded the brain parenchyma. At 3 and 7 days post-injury, complete neuronal loss was observed in the parietal cortex around the impact site. In the ipsilateral cortex, the time-course of histologically assessed neuronal loss and phagocytic/glial activation paralleled the time-course of the loss of omega 1-2 (benzodiazepine) sites (a neuronal marker) and of the increase in p sites (peripheral-type benzodiazepine binding sites; a glial/macrophage marker). Neuronal loss and increase in the density of the glial/macrophage biochemical marker were also observed in the hippocampus but not in the contralateral cortex or in other subcortical structures, suggesting a selective vulnerability of the hippocampus to this traumatic procedure. There was a very good spatial correlation between the histological alterations and the changes in the density of the neuronal and glial/macrophage biochemical markers (as assessed by autoradiography). The volume of the lesion, integrated from the surface of the lesion measured at 10 coronal levels cut at a 1 mm interval and stained with haemalum and eosin, represented 32.9 +/- 1.7 mm3.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1993

Prevention by eliprodil (SL 82.0715) of traumatic brain damage in the rat. Existence of a large (18 h) therapeutic window.

The neuroprotective potential of eliprodil (SL 82.0715), an N-methyl-D-aspartate (NMDA) receptor antagonist acting at the polyamine modulatory site, in brain trauma was examined in a rat model of lateral fluid-percussion brain injury. The volume of the lesion was assessed histologically by measuring, at 7 days post-injury, the area of brain damage at 10 coronal planes. Eliprodil (10 mg/kg i.p.) when given 15 min, 6 h and 24 h after fluid percussion (1.6 atm) and then b.i.d. for the following 6 days, reduced by 60% the volume of cortical damage. A similar neuroprotection was obtained when the first administration of eliprodil was delayed by up to 12 h after the brain insult. Moreover, when the treatment with this compound was started at 18 h post-injury, cortical damage was still significantly reduced by 33%. Autoradiographic studies showed that eliprodil treatment (10 mg/kg, i.p.), initiated 15 min after the trauma, also caused a marked reduction of the loss of the neuronal marker omega 1-2 (central benzodiazepine) binding sites and of the increase in the glial/macrophage marker peripheral type benzodiazepine binding sites in the cerebral cortex. In contrast, dizocilpine (a blocker of the cationic channel coupled to the NMDA receptor) when administered 6 h and 24 h after fluid percussion and then b.i.d. for the following 6 days induced a non significant reduction of the volume of the lesion at the highest tolerated dose (0.6 mg/kg i.p.). These results demonstrate the neuroprotective activity of eliprodil in experimental brain trauma using neuropathology as an endpoint and indicate that there is a very large time window for therapeutic intervention, consistent with the delayed nature of the neuronal loss, in this condition.

Animals↗
PubMed1993

Possible relationship between micronucleated and binucleated cells induced by cisplatin in cultured CHO cells.

Chinese hamster ovary (CHO) cells were treated with a single dose (10 micrograms/ml) of cis-diamminodichloroplatinum (II) (cisplatin) for 1 h and the effect of the drug on the kinetics of proliferation of the cultures was studied. It was found that the drug produces a delay in the proliferation rates of the treated cultures. The induction of micronuclei and binucleated cells (BC) at different times after treatment have also been studied, and the ability of these cells to undergo DNA synthesis (measured as the ability to incorporate [3H]thymidine) is shown. It was also found that cisplatin induced a particular type of BC that contains one or more micronuclei rather than a pure population of BC. The results obtained show a possible relationship between micronuclei and BC. The possibility that some of the micronucleated cells evolve in subsequent cell divisions to BC with micronuclei is suggested.

Animals↗
PubMed1993

Increase in IL-6, IL-1 and TNF levels in rat brain following traumatic lesion. Influence of pre- and post-traumatic treatment with Ro5 4864, a peripheral-type (p site) benzodiazepine ligand.

The effects of fluid percussion trauma on brain interleukin (IL)-6, IL-1 and tumor necrosis factor-alpha (TNF-alpha) levels have been studied. In the cortex and hippocampus of control and sham-operated rats, the levels of these cytokines were very low (below 4 units/mg protein) and constant. IL-6 and IL-1 levels in the ipsilateral cortex increased rapidly following trauma to reach a maximum of 350 and 16 units/mg protein, respectively, 8 h after the lesion, remained elevated until 18 h and decreased thereafter to basal values. TNF-alpha levels were maximally elevated (12 units/mg protein) at 3 h and 8 h and returned to basal values by 18 h. Qualitatively similar changes, but with 25-80-fold smaller amplitude, were seen in the contralateral cortex and in the ipsi- and contralateral hippocampus. The levels of IL-6 in the plasma of sham-operated and lesioned rats were only slightly elevated, whereas IL-1 and TNF-alpha were undetectable. Histological studies of brain tissue at early stages after trauma demonstrated an acute hemorrhage associated with neutrophil invasion. The administration of Ro5 4864 (0.5 mg/kg i.p.), a specific ligand of p (peripheral-type benzodiazepine) binding sites, did not result in any significant effect on the levels of IL-6, IL-1 or TNF-alpha in the brain of control or sham-operated animals. However, when administered 24 h before or 15 min after trauma, this benzodiazepine enhanced the increase of these cytokines by 2-4-fold in the ipsilateral cortex.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1993

Cell wall deficient bacteria as a cause of idiopathic hematuria.

Idiopathic hematuria in the absence of bacteriuria is a medical challenge. Routine cultures of catheterized bladder and endoscopically obtained ureteral urine specimens from a 22-year-old woman with a 6-week history of hematuria showed no growth after 24 to 48 hours of incubation. However, bacterial variants were grown on enriched media. Colonies were typical cell wall deficient/defective bacteria. Phase and electron microscopy of cystoscopic urine specimens obtained by retrograde ureteral catheterization as well as phase microscopy of the cultures revealed the classic morphology of these organisms. When the variant cultures were subcultured the organisms reverted to their related walled forms, that is Streptococcus agalactiae and Staphylococcus haemolyticus. Because the colonies of these organisms showed various patterns of biochemical reactivity, each phenotype was tested against 15 antimicrobials. Collectively, all biotypes had a common susceptibility to only nitrofurantoin. The patient was treated with nitrofurantoin for 6 weeks. Four days after initiation of therapy she had complete remission of hematuria. During the next 3 years she remained well and free of hematuria.

Adult↗
PubMed1993

Different mechanism of relaxation induced by aporphine alkaloids in rat uterus.

We have examined the uterine relaxant action of three aporphine molecules (S-glaucine, S-boldine and R-apomorphine) in two experimental conditions, with and without calcium in the bathing solution, and compared these effects with those obtained with the calcium antagonists verapamil and diltiazem. The present study shows that the alkaloids relax the uterine muscle but with different mechanisms of action. In Ca(2+)-containing solution all three alkaloids relaxed the uterus previously contracted by KCl or acetylcholine, but in Ca(2+)-free medium only R-apomorphine was able to relax oxytocin-induced contraction. The calcium antagonists, verapamil and diltiazem, relaxed KCl- or acetylcholine-induced contraction in Ca(2+)-containing solution, whereas they only relaxed oxytocin-induced contraction in Ca(2+)-free medium at much higher doses. These results suggest that glaucine and boldine behave as specific calcium entry blockers without affecting the contractile machinery or intracellular Ca2+ levels as apomorphine does. The absolute configuration (S-glaucine and S-boldine vs R-apomorphine) may account for this different action.

Acetylcholine↗
PubMed1993

[Testicular seminoma manifested by carcinomatous neuropathy: an unusual presentation. Review of the literature].

Contribution of one patient with tetraparesic picture originated by a major sensory-motor neuropathy, due to paraneoplastic syndrome produced by a testicular seminoma. The patient underwent inguinal orchiectomy and radiotherapy, with favourable evolution of his neurological symptomatology. Review of the literature and confirmation of the extraordinary rarity of such clinical picture.

Adult↗
PubMed1993

[DNA as a prognostic factor in colorectal cancer. A retrospective analysis of 34 patients].

OBJECTIVE: We study the tumoral DNA as a prognostic factor in patients operated for colo-rectal cancer. DESIGN: Retrospective. We analyze by flow cytometry the DNA content of tumoral tissue: Ploidy, DNA Index, Proliferative Index, S Phase. PATIENTS: 34 operated patients, for colo-rectal cancer, with a minimum 3 years of follow-up. RESULTS: Ploidy doesn't show any relation with other prognostic factors. Only Dukes C aneuploid patients had more positive nodes than diploid. Ploidy was not related to better evolution or survival. Neither DNA Index, Proliferative Index and S Phase were related to the evolution of the disease. CONCLUSIONS: The DNA study by flow cytometry has no better prognostic value then other classical factors.

Aged↗