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Biomedical subjects

E Dominguez

Publications and source records attributed to E Dominguez.

At least 19 recordsLinked to original sources
PubMed2007

[Negative endoscopy and MSCT findings in patients with acute lower gastrointestinal hemorrhage. Value of (99m)Tc erythrocyte scintigraphy].

PURPOSE: To evaluate the clinical use of (99m)Tc red blood cell imaging (RBC imaging) in patients presenting with acute lower gastrointestinal (GI) bleeding and negative endoscopy and multislice computed tomography (MSCT) findings. PATIENTS AND METHODS: In 31 consecutive patients with acute lower GI bleeding in whom the endoscopy findings were negative or the procedure was not feasible, dual-phase MSCT of the abdomen was performed [collimation 4x1 mm (arterial phase), 4x2.5 mm (venous phase)]. MSCT was followed by a (99m)Tc red blood cell scan in patients in whom no active bleeding was visible by CT. Images were created within 24 h after administration of the tracer, depending on the clinical symptoms. The results of the imaging modalities were correlated with clinical course and surgical treatment. RESULTS: In 20 of 31 patients MSCT showed no active bleeding and a (99m)Tc red blood cell scan was performed. In 8 of 20 patients RBC imaging was also negative. Of these eight patients five were stable and did not require further diagnostic work-up; in the other three bleeding persisted and these patients required surgical treatment. In 12 of 20 patients active bleeding was demonstrated using a (99m)Tc red blood cell scan. Of 12 patients with positive RBC scintigraphy findings, 8 underwent surgery, where the site of bleeding was confirmed. CONCLUSION: In patients with acute lower GI bleeding with negative or nondiagnostic endoscopy or MSCT findings, (99m)Tc red blood cell imaging is a useful tool in an emergency algorithm, improving the overall bleeding detection rate.

Acute Disease↗
PubMed2005

[Localization of bleeding using 4-row detector-CT in patients with clinical signs of acute gastrointestinal hemorrhage].

PURPOSE: There is no gold-standard regarding the diagnostic work-up and therapy of an acute gastrointestinal (GI) hemorrhage. In most cases endoscopy provides the diagnosis but in a low percentage this modality is not feasible or negative. Purpose of this study was to evaluate the role of multi-phase Multi-Slice-Computertomography (MSCT) as a modality to diagnose and locate the site of acute GI hemorrhage in case of unfeasible or technically difficult endoscopy. MATERIALS AND METHODS: 58 patients, presenting with clinical signs of lower GI hemorrhage, were examined through a 24-month period. Preliminary endoscopy was either negative or unfeasible. Images were obtained with a four-detector row CT with an arterial (4 x 1 mm collimation, 0.8 mm increment, 1.25 mm slice width, 120 kV, 165 mAs) and portal venous series (4 x 2,5 mm collimation, 2 mm increment, 3 mm slice width, 120 kV, 165 mAs). Time interval between endoscopy and CT varied between 30 minutes and 3 hours. The results of the MSCT were correlated with clinical course and surgical or endoscopical treatment. RESULTS: 20 of the 58 patients (34 %) undergoing MSCT had a bleeding site identified, thus providing decisive information for the following intervention. In case of a following therapeutic intervention there was 100 % correlation regarding the bleeding site. In 38 of the 58 patients (66 %), a bleeding site was not identified by MSCT. Twenty of these 38 patients (53 %) were stable and required no further treatment. In 18 of these 38 patients further interventional therapy was required due to continuing hemorrhage and in all of those patients the bleeding site was detected by intervention. CONCLUSION: Compared to other diagnostic methods MSCT is a fast, widely-available and low-risk technique for the localization of active GI hemorrhage. The clinical use seems to be justified since in more than one third of the patients, MSCT demonstrates the site of bleeding and provides decisive information for further interventional therapy. Concerning those patients, in whom MSCT is negative (38 out of 58 patients), only every second patient requires any additional diagnostic work-up.

Acute Disease↗
PubMed2001

Subdural blood patch for the treatment of persistent CSF leak after permanent intrathecal catheter implantation: a report of two cases.

A CSF leak that persists despite conservative therapy may significantly increase the morbidity associated with implantable intrathecal drug delivery systems. This report presents 2 cases where the application of a subdural blood patch led to the satisfactory resolution of a persistent CSF leak after previous epidural blood patches had failed.

Journal Article↗
PubMed2001

Specific immunoglobulins in serum of newborn lambs fed with a single dose of colostrum containing anti-peroxidase IgG.

The apparent efficiency of absorption and the decrease of specific colostral IgG after its passage into the blood stream were determined in newborn lambs fed with a single dose of colostrum containing anti-peroxidase IgG at 30 minutes, 12 hours and 24 hours after birth. When colostrum was given at 30 minutes after birth, a value of 16.9+/-4.0 per cent of anti-peroxidase IgG ingested appeared in lamb circulation. This percentage was reduced to 9.8+/-0.8 per cent when the feeding was done at 12 hours after birth and no specific IgG was detected in lambs fed at 24 hours after birth. The concentration of anti-peroxidase IgG in lambs' serum declined quickly within 96 hours of age to about 48 per cent of the initial value, and afterwards the level decreased slowly reaching a value of 10 per cent at 32 days of age. This behaviour probably reflects the protein distribution and use of absorbed antiperoxidase IgG.

Absorption↗
PubMed2000

A convenient strategy for the synthesis of 4,5-bis(o-haloaryl)isoxazoles

A series of new 1,2-bis(o-haloaryl)ethanones is efficiently prepared and applied to the synthesis of 4,5-bis(o-haloaryl)isoxazoles. Isolation of intermediate hydroxyisoxazolines, which are structurally examined, provides a definitive proof for a heterocyclization mechanism based on an amine exchange process. The isolation and X-ray crystallographic studies of significant side products such as benzamides and triarylpropionitriles are also described.

Journal Article↗
PubMed2000

Asymmetric aldol reactions using (S,S)-(+)-pseudoephedrine-based amides: stereoselective synthesis of alpha-methyl-beta-hydroxy acids, esters, ketones, and 1,3-Syn and 1,3-anti diols

A very efficient method for performing stereoselective aldol reactions is reported. The reaction of (S, S)-(+)-pseudoephedrine-derived propionamide enolates with several aldehydes yielded exclusively one of the four possible diastereomers in good yields, although transmetalation of the firstly generated lithium enolate with a zirconium(II) salt, prior to the addition of the aldehyde, is necessary in order to achieve high syn selectivity. The so-formed syn-alpha-methyl-beta-hydroxy amides were transformed into other valuable chiral nonracemic synthons such as alpha-methyl-beta-hydroxyacids, esters, and ketones. Finally, a stereocontrolled reduction procedure starting from the so-obtained alpha-methyl-beta-hydroxy ketones has been developed allowing the synthesis of either 1,3-syn- or 1,3-anti-alpha-methyl-1,3-diols in almost enantiopure form by choosing the appropriate reaction conditions.

Journal Article↗
PubMed2000

Investigating plant lipid biopolymers.

This paper presents a review of the biological importance and occurrence of plant cutin, the main lipid biopolymer in higher plants. Its chemical composition and structure are reviewed and a short laboratory practical exercise on the extraction, purification and qualitative analysis of fruit cutin is presented.

Journal Article↗
PubMed2000

Meteorological phenomena affecting the presence of solid particles suspended in the air during winter.

Winter is not traditionally considered to be a risky season for people who suffer from pollen allergies. However, increasing numbers of people are showing symptoms in winter. This prompted our investigation into the levels of solid material in the air, and some of the meteorological phenomena that allow their accumulation. This study showed a possible relationship between the phenomenon of thermal inversion, which occurs when very low temperatures, cloudless skies and atmospheric calms coincide, and an increase in the concentration of solid material in the atmosphere. Frequently, this situation is associated with other predictable phenomena such as fog, dew and frost. This may allow a warning system to be derived for urban pollution episodes. The effect caused by parameters such as wind and rainfall was also analysed. Solid material was differentiated into non-biological material from natural and non-natural sources (e.g. soot, dust, sand, diesel exhaust particles, partially burnt residues) and biological material. The latter mainly comprises pollen grains and fungal spores. Owing to its abundance and importance as a causal agent of winter allergies, Cupressaceae pollen was considered separately.

Air Pollutants↗
PubMed1999

Perioperative management of glucose 6 phosphate dehydrogenase deficiency. A review of the literature.

Glucose 6 phosphate dehydrogenase (G6PDH) deficiency is the most frequent cause of hemolytic anemias due to enzyme abnormality. Perioperative management must be careful to avoid the onset of hemolytic crisis. We present a complete review of the literature on this illness and describe the perioperative management of an adult with known G6PD deficiency and the pathogenesis and clinical manifestations of the disorder and its possible anesthetic implications are discussed. A 49-year-old patient had undergone varum osteotomy in her left knee due to genu valgum. She had been diagnosed as having G6PDH deficiency sixteen years earlier provoked by ingesting beans. The perioperative circumstances capable of causing autohemolysis are described and discussed. In spite of the fact that the pattern is self-limited, it provokes the onset of jaundice and anemia which can complicate the recovery. Simple elimination of those elements which precipitate with oxyhemoglobin will allow an uneventful anesthetic procedure.

Anemia, Hemolytic↗
PubMed1998

Fetal natural killer cell function is suppressed.

Previous studies have reported reduced natural killer (NK) cell activity in cord blood (CB) compared with adult blood mononuclear cell populations. Using a non-radioactive killing assay, we have verified these findings suggesting that either the fetal NK cell function is suppressed or that these cells are functionally immature. We have shown that CB NK cells are functional, since activating them with cytokines known to activate adult NK cells [interleukin-2 (IL-2), IL-12 and IL-15] increased activation. However, resting the cells, which enhanced adult NK cell activity (P < 0.01), had no effect on fetal NK cells (P = 0.2). These results suggested that fetal NK cells have the capacity to kill, but this is suppressed in vitro. This hypothesis was strengthened by our observation that eight of nine CB mononuclear cell populations had their NK activity restored by freeze-thawing, whereas four of five adult peripheral blood mononuclear cells had a reduced killing ability on freeze-thawing. Freeze-thawing removes a population of cells that suppresses CB NK cell function. To determine which was the case we performed extensive phenotypic analysis of the CB populations pre- and post-freezing and found that the percentage of the CD3- CD56+ population within CB increased significantly (P < 0.0005 by paired t-test) with freezing, whereas freeze-thawing had no effect on this population within a normal adult peripheral blood mononuclear cell population. Our data suggest that within CB there is a population of cells, as yet undefined, which may be inhibiting NK cell function. This report therefore shows clear differences between NK cells within the adult periphery and in CB, and may lead to a better understanding of events occurring in vivo.

Adult↗
PubMed1998

Influence of the HLA class II polymorphism in chronic Chagas' disease.

Chagas' disease or American trypanosomiasis due to Trypanosoma cruzi has existed at least since the time of the Inca empire and contributes significantly to cardiovascular morbidity and mortality in several countries of this continent. Due to the fundamental role of human class II molecules polymorphic residues in the control of the immune response, a study was designed to define by DNA typing HLA class II alleles in a sample of 67 serologically positive individuals with and without cardiomyopathy and in 156 healthy controls of similar ethnic origin. Genomic DNA extraction, PCR amplification of the HLA-DRB1 and DQB1 second exon regions and hybridization to labelled specific probes were carried out following the 11th International Histocompatibility Workshop reference protocol. Comparison of DRB1 and DQB1 allele frequencies among the patients and control subjects showed a decreased frequency of DRB1*14 and DQB1*0303 in the patients, suggesting independent protective effects to the chronic infection in this population. Allele frequencies comparison between patients with and without cardiomyopathy showed a higher frequency of DRB1*01, DRB1*08 and DQB1*0501 and a decreased frequency of DRB1*1501 in the patients with arrhythmia and congestive heart failure. The results suggest that HLA Class II genes may be associated with the development of a chronic infection and with heart damage in Chagas' disease.

Adult↗
PubMed1998

Foetal lymphocytes are more sensitive to freezing than adult lymphocytes within a mononuclear cell environment.

Previous studies have reported reduced natural killer (NK) cell activity in cord blood (CB) compared to adult blood mononuclear cell populations. We suggest that foetal NK cells have the capacity to kill, but this is suppressed in vitro. This hypothesis is strengthened by our observation that CB mononuclear cell populations had their NK activity restored by freeze/thawing, whereas adult PBMC had a reduced killing ability on freeze/thawing. Thus, either NK cells are activated to kill by the freeze/thawing or there is an NK cell suppressor factor in CB which is lost through freeze/thawing. This report shows clear differences between NK cells within the adult periphery and CB, and may help toward a better understanding of events occurring in vitro.

Adult↗
PubMed1997

Invasive aspergillosis in liver transplant recipients in the 1990s.

Invasive aspergillosis occurred in 26 liver transplant recipients since 1990 at five liver transplant centers. The median time to onset was 17 days after transplantation. Twenty-seven percent of the patients had undergone retransplantation. Invasive aspergillosis occurred significantly earlier after transplantation in smokers than in nonsmokers (P=0.017). Patients with late-onset aspergillosis (occurring after posttransplant day 90) were more likely to have had prior cytomegalovirus infection than those with early-onset aspergillosis (occurring within 90 days of transplantation) (67% vs. 10%, respectively, P=0.013). Only 8% of the patients had received additional corticosteroids or OKT3, which suggests that augmented immunosuppression may not be a relevant risk factor for invasive aspergillosis in the 1990s due to less frequent use of these agents. The median serum bilirubin level of the patients was 21.8 mg/dl, 85% of the patients had renal insufficiency, and 54% were on dialysis before the onset of invasive aspergillosis, which suggest that overall severity of illness, including poorly functioning hepatic allograft and renal failure may be the major determinants of disease occurrence. Overall mortality was 92% (24/26). No difference in mortality could be shown for the patients who received amphotericin B versus liposomal amphotericin B preparations (100% vs. 89%); however, the mean time to death after the initiation of therapy was 20 days in patients who received amphotericin B and 43 days in those who received liposomal amphotericin B preparations.

Adolescent↗