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Biomedical subjects

C García

Publications and source records attributed to C García.

At least 163 records · Page 9Linked to original sources
PubMed1996

[Intussusception: barium vs. pneumatic reduction].

At the Hospital Niño Jesús air pressure enema has recently replaced the use of barium as treatment of choice in the reduction of intussusception. The purpose of this study was to review the air enema reductions done from June 1992 to February 1994 in 137 patients (group II) and to compare them with a previous series of 153 patients that underwent barium reduction treatment (group I). The groups were similar with regard to sex, age and presentins symptoms as well as clinical signs. Successful reduction was achieved in 131 patients (85.6%) out of 146 attempts treated with barium enema and in 124 patients (90.5%) out of 134 attempts treated with air enema. Among the unsuccessful reduction cases, operation was performed in 22 cases in group I and in 13 cases of group II. In the group I there were two perforations during the reduction attempt, while in group II we did not have any with the air enema. There were two recurrent intussusceptions following barium enema reduction and nine following air enema reduction in the first 48 hours. Patients treated with air enema stayed less days at hospital (1,6 days) than those treated with barium (3 days). We believe that the air enema treatment is easy to perform, is lower in cost and presents less morbility, and that it should be considered as the treatment of choice in the initial management of intussusception.

Barium↗
PubMed1996

[Prevalence of depression in hospitalized patients over 65 years old in a medical service of the Military Hospital of Santiago].

AIM: To study the frequency of depression in elderly patients admitted to the Internal Medicine Service of an Institutional Hospital. PATIENTS AND METHODS: Patients over 65 years old admitted to the Internal Medicine Service of the Military Hospital at Santiago. Chile were assessed using the CDS-20 depression questionnaire and the FROMAGE score for dementia. RESULTS: One hundred twenty seven patients (71 female), were assessed. According to the FROMAGE score, 30% had moderate and 35% had severe dementia. Ten percent of males and 12% of females were depressive. Moderately demented patients, females, subjects with low educational levels and those living alone had a higher frequency of depression. According to DSM-III the most frequent diagnosis among depressive patients was "adjustment disorder with depressive mood". Attending physicians made the diagnosis in only 11% of patients with depression. CONCLUSIONS: Depression is frequent among hospitalized elders.

Aged↗
PubMed1996

[Bartonella henselae infection in immunocompetent patients: cat scratch disease].

BACKGROUND: Cat scratch disease, whose etiologic agent is Bartonella henselae, is a benign disease in immunocompetent subjects, characterized by lymphadenopathy of prolonged course and occasional involvement of other organs such as liver, spleen, central nervous system, eye and lung. In immunocompromised patients, the infection is bacteremic and disseminated. AIM: To report Chilean cases of cat scratch disease. PATIENTS AND METHODS: Ten children (seven male, aged between 6 and 13 years old) with histologically or serologically confirmed cat scratch disease are reported. RESULTS: Lymphadenopathy location was pre auricular in four cases, axillary in two, inguinal in two and epitrochlear in two. Three children had fever over 39 degrees C and two had a parinaud syndrome. Nine children had a history of cat scratch and one of a cat byte. Six had an erythrocyte sedimentation rate over 40. Lymph node ultrasound examination was a useful diagnostic tool. Two patients had splenic granulomas. Lymph node biopsies were obtained in four cases, showing a suppurative granulomatous lymphadenitis in all and a positive Warthin-Starry stain in two. Serology, done in patients without histological confirmation was positive with titles ranging from 1:64 to 1:8192. All patients had a satisfactory outcome with regression of lymphadenopathy. CONCLUSIONS: Infections by Bartonella hemselae occur in the Chilean population and must be considered in the differential diagnosis of regional lymph node enlargement.

Adolescent↗
PubMed1995

Biosynthesis and maintenance of GSH in primary astrocyte cultures: role of L-cystine and ascorbate.

We have studied the optimal conditions to maintain the astrocyte GSH levels under normal and oxidative stress conditions. The rate of GSH synthesis from L-methionine was statistically lower than from L-cystine or N-acetyl-cysteine in astrocytes treated with diethyl-maleate, which is a substrate of GSH S-transferases. This is in accordance with the fact that cystathionase activity was not detectable. The transport of L-cystine mediated by the Na(+)-independent system Xc- is the limiting step in GSH synthesis in astrocytes. Incubation with tert-butyl hydroperoxide (t-booH) reduced GSH concentration in astrocytes. This reduction was ameliorated in part by the addition of ascorbate or dehydroascorbate. When L-cystine and ascorbate were added together to the t-booH-treated astrocytes, the GSH concentration was indistinguishable from controls. Electron micrographs of astrocytes treated with t-booH showed an increased number of vacuoles and mitochondrial swelling. This was prevented by ascorbate and dehydroascorbate. The physiological implications of the availability of GSH precursors and ascorbate in the maintenance of GSH in astrocytes are discussed.

Amino Acids↗
PubMed1995

Both prostaglandin E2 and nitric oxide sequentially mediate the tumor necrosis factor alpha-induced inhibition of surfactant synthesis by human type II pneumocytes.

BACKGROUND: Tumor necrosis factor alpha (TNF-alpha)-induced inhibition of surfactant synthesis seems to participate in the pathogenesis of the adult respiratory distress syndrome. OBJECTIVES: To examine the ability of human type II pneumocytes to produce nitric oxide (NO) in the presence of TNF-alpha and, in addition, to explore the role of this radical in the transduction of the cytokine signal. DESIGN: Multiple organ donors were the source of lung tissue specimens. Type II pneumocytes were isolated by enzymatic digestion, adherence separation of macrophages, and gradient purification. After 24-hour preculture, cells were cultured for 24 hours in the presence or absence of TNF-alpha (100 ng/mL), sodium nitroprusside (100 mumol/L), N omega-nitro-L-arginine methyl ester (NAME) (1 mmol/L), methylene blue (10 mumol/L),8-bromo-3',5'-cyclic guanosine monophosphate (8-Br-cGMP) (1 mmol/L), prostaglandin E2 (PGE2) (0.1 mumol/L), indomethacin (30 mumol/L), and combinations. The NO release to the medium and cGMP and PGE2 contents of the cells were measured. RESULTS: The incorporation of 14C-labeled glucose (D-[U-14C]glucose) into phosphatidylcholine and phosphatidylglycerol was selectively inhibited either by 8-Br-cGMP or in the presence of TNF-alpha, PGE2, or nitroprusside, all of which caused an increase in the intracellular levels of cGMP. The inhibitory effect of TNF-alpha was partially reverted by indomethacin, NAME, N-monomethyl arginine, or methylene blue. The inhibitory effect of PGE2 was partially reverted by NAME, while that of nitroprusside was reverted by methylene blue, but not by indomethacin. Tumor necrosis factor alpha induced an increase in PGE2 (4.31 +/- 0.27 vs 1.65 +/- 0.17-pg/microgram protein, n = 10, P < .01) and cGMP (0.238 +/- 0.012 vs 0.109 +/- 0.014-pmol/microgram protein, n = 10, P < .01) cell content and in the NO release to the medium (3.10 +/- 0.14 vs 1.19 +/- 0.11-nmol/microgram protein, n = 10, P < .01). The basal NO release to the medium was also increased in the presence of PGE2. The NAME, which blocked NO generation and cGMP increase, did not affect PGE2 production in response to TNF-alpha. However, indomethacin, which blocked PGE2 production, also blunted NO generation and cGMP increase. CONCLUSIONS: The NO generation, secondary to PGE2 production, seems responsible for the TNF-alpha-induced inhibition of phosphatidylcholine synthesis by human type II pneumocytes. Nitric oxide seems to exert this effect through activation of guanylyl cyclase.

Adolescent↗
PubMed1995

Evidence for a cyclic guanosine monophosphate-dependent, carbon monoxide-mediated, signaling system in the regulation of TNF-alpha production by human pulmonary macrophages.

BACKGROUND AND OBJECTIVES: The second messenger cyclic guanosine 3',5'-monophosphate (cGMP) seems to be implicated in the release of tumor necrosis factor alpha (TNF-alpha) by activated macrophages. There is controversy regarding the potential of human macrophages to produce nitric oxide (NO). Since guanylate cyclase can be activated also by carbon monoxide (CO) and this gas may be formed endogenously, we examined the ability of human pulmonary macrophages to produce CO in the presence of lipopolysaccharide (LPS) or LPS+interferon gamma (IFN-gamma). In addition, the source and the relative contribution of this molecule to the LPS-induced increase in cell cGMP content and TNF-alpha release were explored. DESIGN: Interstitial macrophages were obtained from multiple organ donor lungs by enzymatic digestion. After 24-hour preculture, purified macrophages were cultured for 24 hours in the presence or absence of LPS, LPS+IFN-gamma, CO (250 and 500 mumol/L), sodium nitroprusside, 8-Br-cGMP, hemoglobin, methylene blue, zinc-protoporphyrin IX, hemin, S-adenosylmethionine, deferoxamine mesylate, or combinations. The cGMP content of the cells and TNF-alpha, CO, and NO release to the medium were determined. RESULTS: In the presence of LPS, TNF-alpha production was not accompanied by any detectable increase in the NO release to the medium. However, an increase in medium CO concentration (mean +/- SEM) (5.81 +/- 0.20 vs 3.74 +/- 0.08 pmol/microgram protein; n = 11; P < .01) and cell cGMP content (0.273 +/- 0.021 vs 0.138 +/- 0.019 pmol/microgram protein; n = 10; P < .01) was observed. These changes were more pronounced in the presence of LPS+IFN-gamma. Release of TNF-alpha also was induced by both sodium nitroprusside and 8-Br-cGMP. In contrast, methylene blue, a guanylate cyclase inhibitor, inhibited LPS-, LPS+IFN-gamma-, and sodium nitroprusside-induced TNF-alpha production and cGMP increase; hemoglobin, which traps CO, had a similar effect. CONCLUSION: Intracellular cGMP increase, secondary to an endogenous production of CO, participates in the release of TNF-alpha by activated human pulmonary macrophages.

Adolescent↗
PubMed1995

Beneficial effect of S-adenosylmethionine during both cold storage and cryopreservation of isolated hepatocytes.

Oxygen free radicals appear to be the prime cell-toxic products during cold preservation. Glutathione (GSH) seems to play a critical role in cell protection against oxidant stress. The experimental decrease of intracellular GSH in vivo may be prevented by the administration of S-adenosylmethionine (SAMe), which seems also to play an important role in preserving the structure of cell membranes. We designed our study to investigate whether the addition of SAMe to EuroCollins solution (EC) could provide a similar degree of protection as the more complex University of Wisconsin (UW) solution during cold preservation. In addition, we have investigated a possible protective action of SAMe during hepatocyte cryopreservation. Wistar rat hepatocytes (10(6) cells/ml) were stored in either EC (+/- 12 mumol/l SAMe) or UW. In parallel, hepatocytes (10(6) cells/ml) were cryopreserved in M199 culture medium (+/- SAMe) using dimethyl sulfoxide as cryoprotectant. LDH release, viability, and hepatocyte GSH and malondialdehyde (MDA) content were sequentially determined during cold preservation. There were no differences on viability or GSH and MDA content between EC+SAMe and UW stored cells, although LDH release was slightly higher in the first group. The addition of SAMe also attenuated the decrease in both viability (37 +/- 0.8 vs 53.0 +/- 7.4%, mean +/- SEM, N = 5, P < 0.05) and GSH content (13.4 +/- 15.1 vs 45.1 +/- 16.8%, mean +/- SEM, N = 5, P < 0.01), observed after thawing. Our results suggest that SAMe could be a useful additive for both cold storage and cryopreservation solutions of hepatocytes.

Animals↗
PubMed1995

Prolactin and systemic lupus erythematosus: prolactin secretion by SLE lymphocytes and proliferative (autocrine) activity.

Accumulated evidence suggests that prolactin (PRL) is an important immunoregulator and might have a role in the pathogenesis of systemic lupus erythematosus (SLE). Moreover, a PRL-like molecule is secreted by normal human lymphocytes and acts as an autocrine growth factor for lymphoproliferation. The objective of this study was to explore the PRL-like peptide production by peripheral blood mononuclear cells (PBMC) from patients with SLE. We investigated the PRL secretion by PBMC from six female SLE patients and nine normal subjects (5 women and 4 men). Ficoll-Hypaque isolated PBMC (1 x 10(6) cells/ml) were cultured with and without maximal stimulatory doses of PHA (1 mg/ml) or PWM (1/200). At 72 h of culture supernatants were harvested and used to determine PRL immunoreactivity by a radioimmunoassay (NIDDK-reagents). Cell extracts and concentrated supernatants were prepared to determine PRL by Western blot analysis (NIDDK-reagents). SLE non-stimulated PBMC secreted significantly higher levels of PRL than normal non-stimulated PBMC (8.09 +/- 4.15 ng/ml vs. 3.48 +/- 2.36 ng/ml, P = 0.02 by Mann-Whitney test). High levels of PRL were secreted by SLE-PHA stimulated PBMC (6.88 +/- 4.53 ng/ml) and SLE-PWM stimulated PBMC (16.57 +/- 16.39 ng/ml) compared with normal-PHA stimulated PBMC (5.83 +/- 5.27 ng/ml) and normal-PWM stimulated PBMC (8.54 +/- 5.49 ng/ml), respectively, but the differences were not significant. The maximal production of PRL was found in PWM-stimulated lymphocytes in both groups. Cells extracts prepared from SLE non-stimulated and stimulated PBMC contained a 11 KDa PRL immunoreactive material. Concentrated supernatants from SLE non-stimulated and stimulated PBMC contained both a 11 KDa and a 24-27 KDa PRL immunoreactive material. Our data indicate that PBMC from patients with SLE have an increased production of PRL-like immunoreactive material. This PRL is released in vitro as two different molecular weight forms, and appears to be derived from B rather than T lymphocytes.

Adult↗
PubMed1995

Cryoglobulinemia and other dysproteinemias, familial Mediterranean fever, and POEMS syndrome.

The introduction of newer technology in the past few years, especially the use of second-generation enzyme-linked immunosorbent assays, recombinant immunoblot assays, reverse transcriptase, and DNA amplification, have clearly defined the role of hepatitis C virus as the most important etiologic factor in the development of mixed cryoglobulinemia. This has led to a better understanding of the pathogenic mechanisms involved in disease expression, particularly vasculitis, and also has provided a rationale for the use of interferon alfa and other antiviral drugs in the therapy of these disorders. The clinical manifestations of the syndrome also have been well characterized, as well as some of the risk factors. There also has been an improvement in our understanding of the pathogenic mechanisms involved in multiple myeloma and related monoclonal gammopathies, as well as several attempts to improve early recognition of bone disease with magnetic resonance imaging. The susceptibility gene for familial Mediterranean fever has been better characterized, as have risk factors for colchicine toxicity. The role of cytokines has been better delineated for both monoclonal gammopathies and POEMS (polyneuropathy, organomegaly, endocrinopathy, M protein, and skin changes) syndrome.

Blood Protein Disorders↗
PubMed1995

[Results of the surgical treatment of colorectal cancer: analysis of recurrence and survival in 400 patients].

We analyzed retrospectively the long term survival and recurrence of 400 patients with colorectal cancer operated in a period of 13 years. Kaplan Meier curves were used for survival analysis and Cox's regression for multivariate analysis. Ninety eight percent of 377 surviving patients were followed for a mean period of 34 +/- 36 months (range 12-156). Global recurrence was 32% and higher for rectal than colon cancer. Sixty five percent of recurrences were distant. The main prognostic parameter for recurrence was peritumoral lymph node involvement. The initial tumoral stage was the main prognostic factor for survival. Five years survival probability was 94.4% in stage A, 81.3% in stage B, 63.8% in stage C1, 41.3% in stage C2 and 3.1% in stage D. Preoperative radiation therapy did not improve survival or recurrence. Postoperative radiation therapy prolonged the lapse between surgery and recurrence, without changing overall survival. The prolonged survival of some patients in stage D justifies palliative surgery in this stage.

Adult↗
PubMed1994

[Sepsis by Candida tropicalis in patients with granulocytopenia. A study of 10 cases].

The aim of the present study was to analyze the main clinical and evolutive characteristics of a series of 10 patients diagnosed with sepsis by Candida tropicalis over a 5-year period in a Hematology Unit. The mean age of the 10 patients was 23 years (range 13-66 years) with 6 males and 4 females. Eight patients had acute leukemia, 1 non-Hodgkin's lymphoma and another patient had severe bone marrow aplasia. All the patients presented intense granulocytopenia (< 0.5 x 10(9)/L), had intravenous catheters and were receiving wide spectrum antibiotics as treatment for bacterial infection. The diagnosis of the fungal infection was based on the growth of C. tropicalis in blood cultures together with the evidence of tissue involvement by the fungus. Fever (> 38 degrees C) was the initial symptom of the infection in all the patients, being accompanied by myalgia in 5 cases, pleuritic pain in 2 and septic shock in 1. Violaceous erthymatomous pustules disseminated over the trunk and limbs, the histologic study of which demonstrated the presence of C. tropicalis were observed in 9 patients. Septic metastasis were found in the liver (2 cases), serosae (2 cases), the psoas muscle and the brain (1 case), respectively. Eight patients underwent treatment with amphotericin B which was complemented with 5-fluorocytosin in 6, with death occurring in the remaining 2 patients prior to the start of treatment. Three patients died with active fungal infection (2 by cerebral hemorrhage and 1 by septic shock). In 2 patients the infection evolved to chronic systemic candidiasis and in the remaining 5 patients infection was resolved with hemoperipheral values returning to normal. Sepsis by Candida tropicalis is a severe complication in patients with granulocytopenia, being mainly characterized by fever, cutaneous papulae and, to a lesser extent, muscle pain. Amphotericin B alone, or in combination with 5-fluorocytosin constitute a treatment of choice in this infection, which nonetheless is associated with an undisdainful mortality.

Adolescent↗
PubMed1994

Nitrite/nitrate and cytokine levels in bronchoalveolar lavage fluid of lung cancer patients.

BACKGROUND: Cytokines are produced by tumor cells in vitro, but evidence for in vivo increased production of cytokines in cancer patients is controversial. Conversely, nitric oxide (NO) is implicated increasingly in the mediation of cytokine effects. Lung cancer patients may show an increased local production of cytokines and NO, and chronic paracrine exposure of epithelial lung cells to these medicators may influence the production of surfactant phosphatidylcholine. METHODS: The presence of the cytokine tumor necrosis factor (TNF alpha), interleukin-1 (IL-1), and interleukin-6 (IL-6), as well as NO, cyclic guanosine 3'5' monophosphate (cGMP) and phosphatidylcholine levels in bronchoalveolar lavage fluid (BLF) of lung cancer patients were investigated. Bronchoalveolar lavage fluid was obtained from 30 male smokers: 22 patients with squamous cell lung cancer and 8 subjects without cancer. RESULTS: When compared with the control subjects, the cancer patients had elevated BLF levels of TNF alpha (1.58 +/- 0.47 vs. 0.04 +/- 0.02 pg/microgram protein, P < 0.001), IL-6 (1.39 +/- 0.29 vs. 0.04 +/- 0.02 pg/microgram protein, P < 0.001), and NO2-/NO3- (23.3 +/- 5.6 vs 1.1 +/- 0.6 nmol/mg protein, P < 0.001). However, phosphatidylcholine levels were lower in those with cancer than in the control subjects (3.0 +/- 1.2 vs. 24.8 +/- 6.4 micrograms protein, P < 0.001). CONCLUSIONS: The results showed in vivo production of inflammatory cytokines in human lung cancer and increased tumor-associated NO production, as suggested by increased levels of nitrite/nitrate in the BLF. A decreased phosphatidylcholine content in the BLF also was found in patients with lung cancer.

Bronchoalveolar Lavage Fluid↗
PubMed1994

Binding of retinoids to uteroglobin.

Uteroglobin, a progesterone-binding secretory protein, was shown to bind retinoic acid and retinol in a non-saturable manner, at least up to concentrations of retinoids of 20 microM. Binding is increased about 10-fold by previous reduction of uteroglobin with 10 mM dithiothreitol and it is not affected by previous saturation of the progesterone binding site, suggesting different binding sites for the steroid and the retinoids. The results are discussed in relation to a possible physiological role for this protein.

Animals↗
PubMed1994

Effect of different sepsis-related cytokines on lipid synthesis by isolated hepatocytes.

Cytokines seem to play an important role in the metabolic disturbances that are commonly associated with sepsis. In this study, we analyzed the effect of tumor necrosis factor, interleukin-1 and interleukin-6, as well as that of tumor necrosis factor in combination with interleukin-1 or interleukin-6, both on free fatty acids and on phospholipid synthesis by isolated rat hepatocytes. All three cytokines and combinations caused inhibited D-[U-14C]glucose incorporation into phosphatidylcholine (tumor necrosis factor = 6.39 +/- 1.13 pmol/microgram protein vs. control = 12.90 +/- 0.98 pmol/microgram protein, n = 7; p < 0.001). However, when [U-14C]palmitate was used as radioactive precursor, tumor necrosis factor, either alone or in the presence of the other cytokines, stimulated phosphatidylcholine synthesis. D-[U-14C]glucose incorporation into free fatty acids and triacylglycerol was also significantly stimulated, whereas phosphatidylinositol labeling was found inhibited by the assayed cytokines. Our results demonstrate an effect of sepsis-related cytokines, more evident for tumor necrosis factor, on hepatocyte lipid synthesis either from glucose or palmitate. Also, the findings support the hypothesis that cytokine-induced changes in hepatocyte lipid synthesis can contribute to the impairment in lipidic metabolism seen in patients with sepsis.

Animals↗