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Biomedical subjects

J C Quintana

Publications and source records attributed to J C Quintana.

11 recordsLinked to original sources
PubMed2004

Neutralization of the edema-forming, defibrinating and coagulant effects of Bothrops asper venom by extracts of plants used by healers in Colombia.

We determined the neutralizing activity of 12 ethanolic extracts of plants against the edema-forming, defibrinating and coagulant effects of Bothrops asper venom in Swiss Webster mice. The material used consisted of the leaves and branches of Bixa orellana (Bixaceae), Ficus nymphaeifolia (Moraceae), Struthanthus orbicularis (Loranthaceae) and Gonzalagunia panamensis (Rubiaceae); the stem barks of Brownea rosademonte (Caesalpiniaceae) and Tabebuia rosea (Bignoniaceae); the whole plant of Pleopeltis percussa (Polypodiaceae) and Trichomanes elegans (Hymenophyllaceae); rhizomes of Renealmia alpinia (Zingiberaceae), Heliconia curtispatha (Heliconiaceae) and Dracontium croatii (Araceae), and the ripe fruit of Citrus limon (Rutaceae). After preincubation of varying amounts of each extract with either 1.0 microg venom for the edema-forming effect or 2.0 microg venom for the defibrinating effect, the mixture was injected subcutaneously (sc) into the right foot pad or intravenously into the tail, respectively, to groups of four mice (18-20 g). All extracts (6.2-200 microg/mouse) partially neutralized the edema-forming activity of venom in a dose-dependent manner (58-76% inhibition), with B. orellana, S. orbicularis, G. panamensis, B. rosademonte, and D. croatii showing the highest effect. Ten extracts (3.9-2000 microg/mouse) also showed 100% neutralizing ability against the defibrinating effect of venom, and nine prolonged the coagulation time induced by the venom. When the extracts were administered either before or after venom injection, the neutralization of the edema-forming effect was lower than 40% for all extracts, and none of them neutralized the defibrinating effect of venom. When they were administered in situ (sc at the same site 5 min after venom injection), the neutralization of edema increased for six extracts, reaching levels up to 64% for C. limon.

Animals↗
PubMed2004

Scorpion envenoming in two regions of Colombia: clinical, epidemiological and therapeutic aspects.

To determine clinical and epidemiological features of scorpion stings in two departments of Colombia, a descriptive study was performed in the hospitals of 10 towns from Antioquia (2 256 071 inhabitants) and five from Tolima (630 424 inhabitants). One hundred and twenty-nine cases were admitted during one year, 51 in Antioquia, 78 in Tolima and 41 were children less than 15 years old. Most stings (70.5%) occurred inside the house; 27.9% were on the hands and 26.4% on the feet. The scorpion species involved were Tityus pachyurus (51), Centruroides gracilis (31), T. fuehrmanni (29), T. asthenes (7) and Chactas spp. (1). In 10 cases the scorpion involved was not identified. Systemic envenoming signs (e.g. vomiting, tachypnea) were significantly more frequent in children than in adults (P < 0.05). Four children had hypertension, but none developed pulmonary oedema. One 3-year-old girl, stung by T. asthenes, had acute oedematous pancreatitis. Ninety-eight patients had mild envenoming. Moderate (27 patients) and severe (four patients) envenoming was significantly more frequent in children than in adults (P = 0.003; relative risk = 2.97). A pepsin-digested anti-Centruroides spp. antivenom was administered to 19 of 31 patients presenting systemic envenoming signs. No adverse reactions to antivenom were observed.

Adolescent↗
PubMed2001

[Reversible myocardial ischemia in hypothyroidism: Case report].

A silent, reversible myocardial ischemia with normal coronary angiography and reversible with thyroid hormone substitution, has been recently described in hypothyroid patients. We report a 49 years old male with an abnormal exercise electrocardiogram detected in a preventive medical examination. He had laboratory evidence of hypothyroidism and a history of two years of asthenia and progressive coarsening of the voice. The Thallium myocardial perfusion study, showed an alteration of coronary flow during exercise in the septum and lower wall of the left ventricle. Thyroid hormone substitution was started and three months later, a coronary angiography was normal. After six months a repeated Thallium perfusion study and exercise electrocardiogram were informed as normal.

Coronary Angiography↗
PubMed2000

The dual-isotope ProstaScint imaging procedure: clinical experience and staging results in 145 patients.

PURPOSE: Whole-body, regional planar, and SPECT imaging using the In-111-labeled monoclonal antibody capromab pendetide (In-111 MAb; ProstaScint) has been shown to increase the detection of early disease spread in patients with prostate cancer. However, recognition of metastatic tumor sites can be difficult, especially if the involved nodes are near blood vessels. We have developed an alternate approach to the identification of metastatic sites that is based on a single simultaneous In-111 MAb and Tc-99m RBC SPECT acquisition of the pelvis and abdomen on day 5 after injection. We have also developed software that dynamically subtracts the Tc-99m RBC data set (vascular component) from the In-111 MAb data set (prostate and lymph node component), which allows for easier identification of metastatic sites. METHODS: We evaluated the effectiveness of ProstaScint for staging 145 patients with prostate cancer, 19 newly diagnosed and 126 with recurrence, using these two modifications. RESULTS: With clinical follow-up in 13 of 19 (68%) patients with primary disease, 10 of 13 (78%) had organ-confined disease. With follow-up in 64 of 126 (51%) patients with possible recurrent disease, 49 of 64 (77%) were found to have prostatic fossa activity only. Disease stage was deemed more advanced in 3 of 13 (22%) patients with primary cancer and in 13 of 64 (20%) of those with recurrent disease based on ProstaScint findings when all other imaging tests were inconclusive. Six patients with recurrent disease had negative results of their scans. In the 16 patients with more advanced disease, 3 of 59 lesions (5%) were documented as false positive, and there were no reported cases of false-negative findings. CONCLUSIONS: Using both the dual-isotope procedure and the subtraction analysis software with the ProstaScint examination provides additional information for staging primary and possibly recurrent prostate cancer compared with standard imaging techniques.

Antibodies, Monoclonal↗
PubMed1999

Incorporation of SPECT imaging in a longitudinal cognitive rehabilitation therapy programme.

In this clinical study, five consecutive referrals to a cognitive rehabilitation therapy (CRT) programme were followed in a longitudinal protocol involving a resting SPECT and neuropsychological evaluation at pre-treatment, post-treatment, and post non-treatment intervals. All clients had acquired brain injury and initially demonstrated neuropsychological deficits and various degrees of hypoperfusion on SPECT. Statistical Parametric Mapping (SPM) was used to evaluate change in successive SPECT images. Following CRT, all clients were able to return to productive employment or schooling. Examination of the neuropsychological testing results revealed significant improvement in performance following CRT which were generally maintained during the non-treatment period. SPM analysis of the SPECT data revealed that, in a majority of cases, most of the significant increases in relative cerebral blood flow redistribution were seen during the treatment period, rather than the non-treatment period. The results suggest that, even in individuals who are more than 2 years post-brain damage, relative increases in rCBF can be demonstrated following individualized CRT and that most of these changes can be related to improvements on neuropsychological tests.

Adolescent↗
PubMed1998

[99mTc red blood cell scintigraphy for the assessment of active gastrointestinal bleeding].

BACKGROUND: 99mTc red blood cell scintigraphy is a non invasive diagnostic method for low flow gastrointestinal bleeding. AIM: To assess the diagnostic yield of this method in patients admitted with gastrointestinal bleeding in whom upper gastrointestinal endoscopy was negative. PATIENTS AND METHODS: The clinical records of 59 patients, aged 6 to 90 years old (35 male), with active gastrointestinal bleeding subjected to a 99mTc red blood cell scintigraphy were reviewed. All had non diagnostic upper gastrointestinal endoscopic studies, and in 20 a selective arteriography was performed. RESULTS: In 40 patients the scintigraphy was positive for gastrointestinal bleeding, and in 57% of these the exam was positive during the first hour. Fifteen of the 19 patients with a negative scintigraphy did not have an active clinical bleeding at the moment of the examination. In 24 patients, a final etiological diagnosis was reached. In 93% of these patients scintigraphy correctly identified the bleeding site. In one patient with a negative scintigraphy, angiography disclosed a pseudo aneurysm of the splenic artery that was not bleeding actively. CONCLUSIONS: In these patients with negative upper gastrointestinal endoscopy 99mTc red blood cell scintigraphy had a 91% sensitivity for the diagnosis of active gastrointestinal bleeding.

Adolescent↗
PubMed1997

[Effects of ramipril and spironolactone on ventricular remodeling after acute myocardial infarction: randomized and double-blind study].

BACKGROUND: Studies have shown that angiotensin converting enzyme (ACE) inhibition prevents left ventricular remodeling and cardiovascular events after an acute myocardial infarction. The role of aldosterone in ventricular remodeling after a myocardial infarction has not been addressed. AIM: To compare the effects of an ACE inhibitor, an aldosterone receptor antagonist and placebo on left ventricular remodeling after a first episode of transmural acute myocardial infarction. PATIENTS AND METHODS: Patients hospitalized for a first episode of acute myocardial infarction were blindly and randomly assigned to receive ramipril (2.5 mg bid), spironolactone (25 mg tid) or placebo. Ejection fraction, left ventricular end diastolic and end systolic volumes were measured by multigated radionuclide angiography, at baseline and after six months of treatment. RESULTS: Twenty four patients were assigned to placebo, 31 to ramipril and 23 to spironolactone. Age, gender, Killip class, treatment with thrombolytics, revascularization procedures and use of additional medications were similar in the three groups. After six months of treatment, ejection fraction increased from 34.5 +/- 2.3 to 40.2 +/- 2.4% in patients on ramipril, from 32.6 +/- 2.9 to 36.6 +/- 2.7% in patients on spironolactone, and decreased from 37 +/- 3 to 31 +/- 3% in patients on placebo (ANOVA between groups p < 0.05). Basal end systolic volume was similar in all three groups, increased from 43.4 +/- 3.4 to 61.4 +/- 6.0 ml/m2 in patients on placebo and did not change in patients on spironolactone or ramipril (ANOVA p < 0.05). End diastolic volume was also similar in the three groups, increased from 70.6 +/- 4.3 to 92.8 +/- 6.4 ml/m2 in patients on placebo and did not change with the other treatments. CONCLUSIONS: Ramipril and spironolactone had similar effects on ventricular remodeling after acute myocardial infarction, suggesting that aldosterone contributes to this phenomenon and that inhibition of its receptor may be as effective as ACE inhibition in its prevention.

Analysis of Variance↗
PubMed1996

[Nationally produced 153SmEDTMP in the palliative treatment of metastatic bone cancer pain].

153SmEDTMP was obtained from enriched 152Sm irradiated at the 5 MW Chilean Research Reactor and labelled at a molar ratio of 15:1 pH 7.5. Biodistribution, autoradiography, radiochemical purity tests were done for evaluation. 40 patients were treated with 37-55 MBq/kg weight. Bone scans using 99mTcHMDP were obtained prior and after treatment. Bone marrow depression was observed in 37% of them and normal liver function in all of them. In 45% the pain dissapear completely, in 22.5% significantly decreased and partially in 30%. In 17 patients more than one dosis was injected. Our preliminary results indicate that 153SmEDTMP is a promising radiotherapeutic agent for palliative treatment of metastatic bone cancer pain and encourage its use specially because it can be produced in countries with low economic resources, thus a large number of patients can get the benefits of this new procedure.

Adult↗
PubMed1995

Treatment of acute infantile diarrhoea with a commercial rice-based oral rehydration solution.

This randomized clinical trial compared the efficacy of an oral rehydration solution (ORS) formulated with commercial rice powder, 50 g/l, with that of a glucose-based WHO/UNICEF-recommended ORS in the management of 48 inpatients aged 3-24 months, with acute dehydrating watery diarrhoea. Stool outputs were generally high in these patients, and 11 patients (22%) required additional intravenous rehydration solutions. The stool output (ml/kg) in the first 24 hours was [geometric mean, (95% confidence intervals)] 213 (153-353) in the rice-ORS group versus 146 (108-232) in the glucose-ORS group, while the total stool output was 455 (298-933) versus 307 (209-625); (p value not significant). The mean (+/- SD) duration of diarrhoea in hospital was: 72 +/- 10 hours in the study group versus 77 +/- 12 hours in the control group (p value NS). Enteropathogens were found in 94% of the patients, rotavirus being prevalent in 85% of the cases. It is concluded that the rice-ORS used in this trial is no more efficacious than the standard glucose-ORS advocated by WHO/UNICEF in the treatment of infants with watery non-cholera dehydrating diarrhoea. In some cases, ORS formulated with the commercial cereal-based products might actually increase the stool losses in infants with high-output non-cholera diarrhoea.

Acute Disease↗
PubMedDate not supplied

[Analog gamma camera digitalization computer system].

OBJECTIVE: Digitalization of analogue gamma cameras systems, using special acquisition boards in microcomputers and appropriate software for acquisition and processing of nuclear medicine images is described in detail. MATERIAL AND METHODS: Microcomputer integrated systems interconnected by means of a Local Area Network (LAN) and connected to several gamma cameras have been implemented using specialized acquisition boards. The PIP software (Portable Image Processing) was installed on each microcomputer to acquire and preprocess the nuclear medicine images. A specialized image processing software has been designed and developed for these purposes. This software allows processing of each nuclear medicine exam, in a semiautomatic procedure, and recording of the results on radiological films. RESULTS: . A stable, flexible and inexpensive system which makes it possible to digitize, visualize, process, and print nuclear medicine images obtained from analogue gamma cameras was implemented in the Nuclear Medicine Division. Such a system yields higher quality images than those obtained with analogue cameras while keeping operating costs considerably lower (filming: 24.6%, fixing 48.2% and developing 26%.) CONCLUSIONS: Analogue gamma camera systems can be digitalized economically. This system makes it possible to obtain optimal clinical quality nuclear medicine images, to increase the acquisition and processing efficiency, and to reduce the steps involved in each exam.

Computers↗