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Biomedical subjects

E Garcia

Publications and source records attributed to E Garcia.

At least 73 records · Page 4Linked to original sources
PubMed1999

Prognostic value of cerebrospinal fluid cytology in pediatric medulloblastoma. Swiss Pediatric Oncology Group.

BACKGROUND: Although the demonstration of leptomeningeal dissemination is the most important predictor of poor outcome in children with medulloblastoma, there is lack of consensus on the prognostic value of a positive cerebrospinal fluid (CSF) cytology (i.e., stage M1). PATIENTS AND METHODS: Eighty-six pediatric medulloblastoma patients treated in Switzerland between 1972-1991 were retrospectively studied regarding the influence of M-stage on prognosis. 39 were M0, 13 M1, 15 Mx, 17 M2, and 2 M3. RESULTS: Five- and 10-year overall survival rates were 76% and 54% for M0, 68% and 50% for Mx, 36% and 25% for M1, and 22% and 22% for M2-3 (P < 0.001), respectively. No significant survival differences were observed between M1 and M2-3 patients. Among 26 patients with only postoperative CSF cytologies, seven were positive. Their outcome was similar to that of six preoperatively staged M1 and significantly different from that of M0 patients (P = 0.001). In 14 patients both pre- and postoperative CSF cytology was performed. Total agreement was observed between the pre- and postoperative results (six positive and eight negative). Among the 19 M2-3 patients CSF cytology was positive in eight, negative in five, and unknown in six. CONCLUSIONS: A positive CSF cytology either pre- or postoperatively predicts for a poor outcome, similar to that observed in stage M2-3 patients. A postoperative cytology is likely to be concordant with cytologic results obtained preoperatively, and seems to have the same prognostic significance. A negative cytology, however, does not exclude a more advanced stage.

Adolescent↗
PubMed1999

Molecular characterization of KatY (antigen 5), a thermoregulated chromosomally encoded catalase-peroxidase of Yersinia pestis.

The first temperature-dependent proteins (expressed at 37 degrees C, but not 26 degrees C) to be identified in Yersinia pestis were antigens 3 (fraction 1), 4 (pH 6 antigen), and 5 (hereafter termed KatY). Antigens 3 and 4 are now established virulence factors, whereas little is known about KatY, except that it is encoded chromosomally, produced in abundance, possesses modest catalase activity, and is shared by Yersinia pseudotuberculosis, but not Yersinia enterocolitica. We report here an improved chromatographic method (DEAE-cellulose, calcium hydroxylapatite, and Sephadex G-150) that yields enzymatically active KatY (2,423 U/mg of protein). Corresponding mouse monoclonal antibody 1B70.1 detected plasminogen activator-mediated hydrolysis of KatY, and a polyclonal rabbit antiserum raised against outer membranes of Y. pestis was enriched for anti-KatY. A sequenced approximately 16-kb Y. pestis DNA insert of a positive pLG338 clone indicated that katY encodes an 81.4-kDa protein (pI 6.98) containing a leader sequence of 2.6 kDa; the deduced molecular mass and pI of processed KatY were 78.8 kDa and 6. 43, respectively. A minor truncated variant (predicted molecular mass of 53.6 kDa) was also expressed. KatY is similar (39 to 59% identity) to vegetative bacterial catalase-peroxidases (KatG in Escherichia coli) and is closely related to plasmid-encoded KatP of enterohemorrhagic E. coli O157:H7 (75% identity). katY encoded a putative Ca2+-binding site, and its promoter contained three homologues to the consensus recognition sequence of the pCD-encoded transcriptional activator LcrF. rbsA was located upstream of katY, and cybB, cybC, dmsABC, and araD were mapped downstream. These genes are not linked to katG or katP in E. coli.

Amino Acid Sequence↗
PubMed1999

Asymptomatic intracardiac thrombi and primary antiphospholipid syndrome.

Intracardiac thrombi have rarely been reported in patients with the antiphospholipid syndrome. We describe a new case revealed by systematic echocardiography in an asymptomatic woman who consulted for mild thrombocytopenia. Our case is characterized by a past history of migraine, fetal loss and psychiatric disturbances and by a high level of antiphospholipid antibodies (anticardiolipin, anti-beta(2)-glycoprotein I and lupus anticoagulant). Echography, in the absence of any cardiovascular symptom, showed bulky right intra-atrial thrombi requiring surgical excision. Histopathological analysis revealed the fibrino-cruoric nature of the lesion without myxoma. This case shows that, when faced with a mild thrombocytopenia associated with antiphospholipid antibodies, echocardiography may reveal a life-threatening and completely asymptomatic intracardiac thrombosis.

Adult↗
PubMed1999

Modulation of rat preadipocyte adipose conversion by androgenic status: involvement of C/EBPs transcription factors.

Androgenic status affects rat preadipocyte adipose conversion from two deep intra-abdominal (epididymal and perirenal) fat depots differently. The aim of this study was to establish whether these site-specific alterations of adipogenesis are related to altered expressions of the transcriptional factors regulating proliferation and differentiation of preadipocytes, c-myc and CCAAT/enhancer binding proteins (C/EBPs: C/EBPalpha and beta). The increased proliferation of epididymal and perirenal preadipocytes from castrated rats was not linked to variations in c-myc mRNA and protein levels. The expression of the early marker of adipogenesis, lipoprotein lipase (LPL), was decreased by androgenic deprivation in epididymal cells but remained insensitive to the androgenic status in perirenal preadipocytes. In contrast, LPL expression increased in subcutaneous preadipocytes from castrated rats, an effect which was partly corrected by testosterone treatment. Expression of C/EBPbeta was unaffected by androgenic status whatever the anatomical origin of the preadipocytes. In contrast, the mRNA and protein levels of C/EBPalpha were greatly decreased by androgenic deprivation in epididymal cells, an alteration which could not be corrected by in vivo testosterone administration. Altogether these results demonstrated that in preadipocytes androgenic deprivation affects site-specifically the expression of LPL, an early marker of adipogenesis and of C/EBPalpha, a master regulator of adipogenesis. These observations contribute to an explanation of why castration induces defective adipose conversion in rat epididymal preadipocytes specifically.

Adipocytes↗
PubMed1999

[Prospective study on the mechanism of myocardial infarction without significant coronary stenosis].

The aim of this study was to evaluate prospectively the respective roles of the atheromatous plaque, coronary spasm and abnormalities of haemostasis in patients with myocardial infarction with normal coronary arteries. The study population included 25 patients (19 men and 6 women) with a mean age of 52.1 +/- 11.1 years (34-76 years). The diagnosis of myocardial infarction was made as the finding of 2 out of 3 WHO criteria. It occurred spontaneously and was transmural in 80% of cases, inferior wall infarction in 9 patients (36%), anterior in 12 (48%) and lateral in 4 patients (16%). All patients underwent investigation on average 10 days after infarction (1-42 days) by coronary angiography with quantitative angiography, endocoronary ultrasonography, an ergometrine provocation test for coronary spasm and a blood coagulation study. Coronary angiography was normal in 4 patients but showed wall changes without stenosis > 50% in 20 patients and one case of aneurysmal arterial disease. Intracoronary thrombosis was detected in 6 cases. Endocoronary ultrasonography confirmed the normality of the coronary arteries in 2 cases and showed atheroma in 23 cases (soft atheroma: n = 17 and hard: n = 6). It detected 66% of the coronary thrombi observed at angiography and found 3 other cases. Coronary spasm was verified in 10 patients (40%). The coagulation study was normal in 19 patients and showed increase in Pai-1 in 5 patients and primary thrombocythemia in one case. The authors conclude that coronary angiographic data is less accurate than endo-coronary ultrasonography which best shows the extent and, above all, the nature of the plaques present in 23 of the cases (92%). Coronary spasm may be a contributing factor in 40% of cases, in situ thrombosis in 36% of cases despite usually normal blood clotting studies. None of these abnormalities was observed in one case. The embolic cause of infarction was certain in 2 cases.

Adult↗
PubMed1998

Randomised comparison of implantation of heparin-coated stents with balloon angioplasty in selected patients with coronary artery disease (Benestent II)

BACKGROUND: The multicentre, randomised Benestent-II study investigated a strategy of implantation of a heparin-coated Palmar-Schatz stent plus antiplatelet drugs compared with the use of balloon angioplasty in selected patients with stable or stabilised unstable angina, with one or more de-novo lesions, less than 18 mm long, in vessels of diameter 3 mm or more. METHODS: 827 patients were randomly assigned stent implantation (414 patients) or standard balloon angioplasty (413 patients). The primary clinical endpoint was event-free survival at 6 months, including death, myocardial infarction, and the need for revascularisation. The secondary endpoints were the restenosis rate at 6 months and the cost-effectiveness at 12 months. There was also one-to-one subrandomisation to either clinical and angiographic follow-up or clinical follow-up alone. Analyses were by intention to treat. FINDINGS: Four patients (one stent group, three angioplasty group) were excluded from analysis since no lesion was found. At 6 months, a primary clinical endpoint had occurred in 53 (12.8%) of 413 patients in the stent group and 79 (19.3%) of 410 in the angioplasty group (p=0.013). This significant difference in clinical outcome was maintained at 12 months. In the subgroup assigned angiographic follow-up, the mean minimum lumen diameter was greater in the stent group than in the balloon-angioplasty group, (1.89 [SD 0.65] vs 1.66 [0.57] mm, p=0.0002), which corresponds to restenosis rates (diameter stenosis > or =50%) of 16% and 31% (p=0.0008). In the group assigned clinical follow-up alone, event-free survival rate at 12 months was higher in the stent group than the balloon-angioplasty group (0.89 vs 0.79, p=0.004) at a cost of an additional 2085 Dutch guilders (US$1020) per patient. INTERPRETATION: Over 12-month follow-up, a strategy of elective stenting with heparin-coated stents is more effective but also more costly than balloon angioplasty.

Adult↗
PubMed1998

Electropolymerization of pyrrole and immobilization of glucose oxidase in a flow system: influence of the operating conditions on analytical performance.

The in situ potentiostatic electropolymerization of pyrrole (Py) on a Pt electrode in a thin-layer amperometric cell and the entrapment of the enzyme glucose oxidase (GOx) for the determination of glucose are reported. Polypyrrole (PPy) is directly formed by continuous passage of a buffered solution of the monomer (0.4 M) and enzyme (250 U mL-1) at pH 7 at a flow rate of 0.05-0.1 mL min-1 under a constant applied potential of +0.85 V vs Ag/AgCl decreases. The electrosynthesis of PPy by injection of 500 microL of a Py + GOx solution in a carrier electrolyte consisting of 0.05 M phosphate buffer and 0.1 M KCl at pH 7.0 was also assayed. The influence of the electropolymerization conditions on the analytical response of the sensor to glucose was investigated. The analytical performance of the PPy/GOx sensor was also studied in terms of durability and storage life, as well as selectivity against electroactive species such as ascorbic acid and uric acid as a function of the thickness of the polymer film formed.

Electrochemistry↗
PubMed1998

[Nasogastric tube: intratracheal malposition and entrapment in a bronchial suture].

We report the unrecognized accidental intratracheal insertion of a nasogastric tube, following endotracheal intubation in a patient scheduled to undergo right lower lobectomy for carcinoma. After surgery, which had an unremarkable course, the trachea was extubated. However, the gastric tube was entrapped and attempts to withdraw it elicited fits of coughing. A chest X-ray showed the tube malpositioned in the right bronchus. A fibreoptic bronchoscopy did not permit removal of the tube extremity which was embedded in the bronchial suture. Finally an additional thoracotomy was required to withdraw the tube securely. The manifestations of the intratracheal position of a nasogastric tube as well as the preventive and diagnostic measures of such a complication are considered.

Aged↗
PubMed1998

Textural modification of processing tomatoes.

Knowledge of the textural properties of processing tomatoes is crucial to ensuing product acceptability; measurement, control, and optimization of these properties through judicious selection of varieties and control of unit operations results in products that the consumer prefers. It is important to first define the terms texture, rheology, consistency, and viscosity prior to discussing principles of their measurement. The textural properties of processing tomatoes may be measured using both sensory and objective tests, and the latter may be either destructive or nondestructive in nature. The unique anatomy of tomato fruit (peel, pericarp, columella, and locules) in part dictates the method of texture measurement. Numerous factors, including variety, maturity, genetic modification, cultural particles, and environmental conditions, processing conditions, and calcium addition affect the textural integrity of tomatoes. Textural properties of raw tomatoes and most processed tomato products are reviewed in this article.

Food Handling↗
PubMed1998

Stent implantation in acute myocardial infarction using a heparin-coated stent: a pilot study as a preamble to a randomized trial comparing balloon angioplasty and stenting.

Preliminary experience with primary stenting in myocardial infarction has suggested a greater benefit in clinical outcome than has been obtained with direct balloon angioplasty. However, subacute thrombosis (SAT) remains a limitation for this new mode of therapy. In the BENESTENT II Pilot and main trials, the incidence of SAT with the heparin-coated Palmaz-Schatz stent was only 0.15%. Therefore, as a preamble to a large randomized trial, the feasibility and safety of the use of the Heparin-Coated Palmaz-Schatz trade mark Stent in Acute Myocardial Infarction (AMI) was tested in 101 patients enrolled between April and September 1996 in 18 clinical centres. In 101 stent-eligible AMI patients, as dictated by protocol, a heparin-coated stent was implanted. The primary objectives were to determine the in-hospital incidence of major adverse cardiac events (MACE: death, MI, target lesion revascularization) and bleeding complications, while the secondary objectives were the procedural success rate and the MACE, the restenosis and reocclusion rates at 6.5 months. Stent implantation (n 3 129 stents) was successful in 97 patients of the 101 who were included in this trial. During their hospital stay, two patients died and no patient experienced re-infarction, ischaemia prompting re-PTCA or CABG. Four patients suffered a bleeding complication, three major and one minor, of whom three required surgical repair. At 210 days follow-up, 81% of the patients were event free. At 6.5 months restenosis was documented in 18% of the 88 patients who underwent follow-up angiography, including three total occlusions. The results, both with respect to QCA and the occurrence of MACE, compare favourably with studies using elective stenting in both stable and unstable angina patients. As a result of this pilot study, a large randomized trial comparing direct balloon angioplasty with direct stenting in 900 patients with AMI was initiated in December 1996.

Journal Article↗
PubMed1998

Acute hypercapnia increases the oxygen-carrying capacity of the blood in ventilated dogs.

OBJECTIVE: To test the hypothesis that PaCO2 levels generated during permissive hypercapnia may enhance arterial oxygenation, when ventilation is maintained. DESIGN: Prospective study. SETTING: Research laboratory in a hospital. SUBJECTS: One group of eight mongrel dogs (four male; four female). INTERVENTIONS: The dogs were anesthetized (30 mg/kg iv pentobarbital), intubated, and cannulated in one femoral artery and vein. While paralyzed with 0.1 mg/kg/hr iv vecouronium bromide, all subjects were ventilated with room air. Anesthesia was maintained, using 2 to 3 mg/kg/hr iv pentobarbital. Arterial hypercapnia at the levels generated during permissive hypercapnia was produced by stepwise increases in the dry, inspired Pco2 (PiCO2) (0, 30, 45, 60 and 75 torr [0, 4, 6, 8, and 10 kPa]; 15 mins each). MEASUREMENTS AND MAIN RESULTS: Blood gas profiles were determined at each level of hypercapnia. The minute volume was maintained at the baseline level during all exposures. Arterial hypercapnia produced gradual and significant increases in the hemoglobin concentration. These increases were approximately 6%, 7%, 11%, and 14% at PiCO2 of 30, 45, 60, and 75 torr (4, 6, 8, and 10 kPa), respectively (p < .05; repeated analysis of variance followed by Dunnett multiple comparisons test). In parallel, the oxygen content increased by approximately 6%, 7%, 11%, and 13%, respectively. During hypercapnic trials, the PaO2 remained at the normal range, whereas the dry, inspired PO2 (PiO2) was reduced from 150 to 138 torr (20 to 18.4 kPa). The average PaO2 at the highest investigated level of arterial hypercapnia was at a normal range. The hemoglobin concentration and oxygen content returned to baseline values 30 mins after hypercapnic trials. The PaCO2 and pH became normalized 15 mins after hypercapnic trials. Indirect evidence for a similar response to hypercapnia in humans is presented. CONCLUSIONS: Permissive hypercapnia due to inhaled CO2 increases oxygen-carrying capacity in dogs. The PaO2 remains at normal range even at a PiCO2 of 75 torr (10 kPa). The benefits of these effects during permissive hypercapnia, due to controlled hypoventilation, warrants investigation.

Acute Disease↗
PubMed1998

Structural organization of virulence-associated plasmids of Yersinia pestis.

The complete nucleotide sequence and gene organization of the three virulence plasmids from Yersinia pestis KIM5 were determined. Plasmid pPCP1 (9,610 bp) has a GC content of 45.3% and encodes two previously known virulence factors, an associated protein, and a single copy of IS100. Plasmid pCD1 (70,504 bp) has a GC content of 44.8%. It is known to encode a number of essential virulence determinants, regulatory functions, and a multiprotein secretory system comprising the low-calcium response stimulation that is shared with the other two Yersinia species pathogenic for humans (Y. pseudotuberculosis and Y. enterocolitica). A new pseudogene, which occurs as an intact gene in the Y. enterocolitica and Y. pseudotuberculosis-derived analogues, was found in pCD1. It corresponds to that encoding the lipoprotein YlpA. Several intact and partial insertion sequences and/or transposons were also found in pCD1, as well as six putative structural genes with high homology to proteins of unknown function in other yersiniae. The sequences of the genes involved in the replication of pCD1 are highly homologous to those of the cognate plasmids in Y. pseudotuberculosis and Y. enterocolitica, but their localization within the plasmid differs markedly from those of the latter. Plasmid pMT1 (100,984 bp) has a GC content of 50.2%. It possesses two copies of IS100, which are located 25 kb apart and in opposite orientations. Adjacent to one of these IS100 inserts is a partial copy of IS285. A single copy of an IS200-like element (recently named IS1541) was also located in pMT1. In addition to 5 previously described genes, such as murine toxin, capsule antigen, capsule anchoring protein, etc., 30 homologues to genes of several bacterial species were found in this plasmid, and another 44 open reading frames without homology to any known or hypothetical protein in the databases were predicted.

Base Composition↗
PubMed1998

Clinical and Angiographic Results with the Multi-Link Stent Implanted under Intravascular Ultrasound Guidance (West-2 Study).

In view of the side effects of ticlopidine, stenting with the sole use of aspirin as post-stent treatment, has been attempted under the guidance of intravascular imaging to guarantee the optimization of the deployment. It was also hypothesized that optimal stenting under IVUS guidance would subsequently reduce the restenosis rate. With these aims the WEST-2 trial using the ACS MULTI-LINK stent was designed. This stent is composed of multiple corrugated rings connected to multiple links Ñ a design that combines radial strength, flexibility and conformability. In WEST-2, between February 1996 and August 1996, 18 centers enrolled 165 patients with stable or stabilized unstable angina and a single de novo lesion in vessel sizes ³ 2.75 mm. Optimal stenting was assessed using predefined QCA (DS% post-stent ³ 15% and stent/artery ratio ³ 1) and IVUS criteria. Patients fulfilling all criteria were treated with aspirin alone. MACE (death, MI, target lesion revascularization) as well as the restenosis rate were assessed at 6 months. In view of the results it may be concluded that the use of aspirin alone as post-stent treatment is safe when preset IVUS criteria are achieved. The target lesion revascularization rate, the restenosis percentage and the incidence of MACE encountered in this registry are among the lowest observed so far.

Journal Article↗
PubMed1998

Multi-Link Stenting in Acute Myocardial Infarction.

ACS Multi-Linkª stent is a stainless steel balloon expandable stents composed of 12 rings connected by multiple links giving a great flexibility and radial strength. Multi-Link stenting offers good clinical and angiographic results in patients with unstable and stable angina, but there are few reports about Multi-Link stent placement in acute myocardial infarction (AMI). In this study, the experience of Multi-Link stenting during primary PTCA is described. RESULTS: 38 Multi-Link stents were placed in the culprit vessel in 34 patients with AMI. Mean age was 67 +/- 14 years, 25 (74%) were male, 12 (35%) were in Killip class III or IV and 20 (59%) had multi-vessel disease. All 38 Multi-Link stents (100%) could be successfully delivered. Angiographic success was achieved in 32 patients (94%). After stenting, stenosis decreased from 95 +/- 9% to 9 +/- 5% (p < 0.001) and minimal lumen diameter increased from 0.2 +/- 0.5 to 2.9 +/- 0.5 mm (p < 0.001). One patient (3%) suffered a subacute thrombosis requiring a new PTCA, but no patient needed surgical revascularization. Seven patients (20.6%; 95% CI: 8.7Ð37.9%) died during hospitalization, 6 of whom were in cardiogenic shock at admission. Mortality in patients with and without cardiogenic shock at admission was 85.7% (95% CI: 42.1Ð99.6%) and 3.7% (95% CI: 0.1%Ð20.0%) respectively (p < 0.001). CONCLUSION: The Multi-Link stent offers good angiographic results in patients with AMI. The in-hospital mortality in patients without cardiogenic shock at admission is low.

Journal Article↗
PubMed1998

[Frequency and nature of atheroma at the site of spasm of angiographically normal or subnormal coronary arteries: an endocoronary ultrasonographic study].

Anatomical studies suggest that sites of coronary spasm are subject to early atherosclerosis. Coronary angiography is unable to confirm the lesions or provide information about their nature. On the other hand, endocoronary ultrasound is able to identify and, it is hoped, to determine the frequency and composition of the lesions. Nineteen patients with chest pain and angiographically normal or subnormal coronary arteries were included in a prospective study (16 men and 3 women: average age 53 +/- 10 years). Four patients had spontaneous spasm and in the other 15, spasm was induced by intravenous injection of ergometrine (6 micrograms/kg). After countering the spasm with isosorbide dinitrate, the site of spasm and adjacent segments were examined by endocoronary ultrasound. Localised vasospasm which was stenotic in 14 cases and obstructive in 5 cases, was observed. The ECG was unchanged in 4 cases and showed ST-T segment changes in 15 cases. The artery affected was the left anterior descending in 10 cases, the left circumflex in 2 cases and the right coronary in 7 cases. A plaque of atheroma, defined as significant intimal thickening, was detected in 18 out of the 19 cases. This atheroma was classified as soft in 17 cases and hard in one case. The authors conclude that vasospasm is not only associated with a plaque of atheroma, nearly always suspected at coronary angiography, but also its composition is nearly always soft (lipidic) from ultrasonographic data.

Adult↗