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Biomedical subjects

P Domínguez

Publications and source records attributed to P Domínguez.

At least 19 recordsLinked to original sources
PubMed2002

Regularity in irregular echinoids.

Using the mathematical concept of eutactic star, we prove that it is possible to define a morphospace for irregular echinoids by using a single parameter. In particular, we have found an extraordinary geometric property in the flower-like patterns of the five ambulacral petals of these animals. This property is fulfilled with great accuracy for a large collection of fossil specimens and provides new insights in the study of the viable skeletal designs of extinct and/or living organisms.

Animals↗
PubMed2001

[Utility of SPECT with 99m Tc-tetrofosmin and stimulus with dipyridamole in patients with permanent ventricular pacemakers].

BACKGROUND AND OBJECTIVE: Patients with permanent ventricular pacemakers (PP) are a difficult subgroup to assess in the study of coronary artery disease. The objective of this study was to evaluate the diagnostic value of the myocardial perfusion scintigraphy with 99mTC-Tetrofosmin (Tc-Tf) and stimulus with dipyridamole in patients with PP and suspected coronary artery disease. PATIENTS AND METHODS: Fourteen patients with suspected coronary artery disease and without structural cardiopathy, who underwent Tc-Tf and cardiac catheterization, were studied retrospectively. Sensitivity, specificity, predictive values and Kappa index were calculated for the diagnosis of coronary artery disease, multivessel disease, and for each one of the coronary arteries (left anterior descending, right coronary, and circumflex). In addition, the correlation between the number of territories with perfusion defects and the number of diseased vessels was studied. RESULTS: In regards to the diagnosis of coronary artery disease, sensitivity, specificity, positive predictive value, negative predictive value and the Kappa index were 100%, 50%, 83%, 100% and 0.55, respectively. For multi-vessel disease, these values were 83%, 64%, 64%, 83% and 0.43 respectively. The correlation coefficient between the number of territories with perfusion defects and the number of diseased vessels was 0.61 (p = 0.02). In the diagnosis of anterior descending disease, sensitivity and specificity were 83% and 88% respectively. For the right coronary artery, these values were 100% and 44% and for the circumflex artery 38% and 83%, respectively. CONCLUSION: In patients with PP and suspected coronary artery disease, myocardial perfusion scintigraphy with Tc-Tf and stimulus with dipyridamole is of great value in the diagnosis of coronary artery disease and in the assessment of its extension.

Aged↗
PubMed2001

[Hemarthrosis as a hemorrhagic complication after thrombolytic treatment].

Hemorrhage of variable severity is the main complication of thrombolytic treatment. We present the case of a rare hemorrhagic location after the use of this treatment for acute myocardial infarction, as ankle hemarthrosis. In the first twelve hours the patient had a joint hemorrhagic effusion with refractory pain and arthrocentesis was required. Recurrence occurred while receiving heparin and after discontinuation of heparin perfusion stopped the patient developed occlusion of the coronary artery related to the infarct requiring emergency angioplasty. We discuss the severity and possible treatment of this situation.

Adult↗
PubMed2001

[Meaning of clinical and electrical positivity in the myocardial perfusion scintigraphy during the administration of dipyridamole].

BACKGROUND AND OBJECTIVES: Administration of dipyridamole produces angina and ST depression in 20%-30% and 6%-34% of patients, respectively. This study aimed to evaluate the clinical implications of the presentation of angina and/or ST depression during the administration of dipyridamole in the study of coronary heart disease by myocardial perfusion SPECT (MPS). METHODS: The study population is constituted by 593 consecutive patients without left branch block or ventricular pacemaker rhythm who were referred to our service to undergo MPS with dipyridamole. A SPECT was performed after the administration of 99mTc-tetrosfosmine and drug stimulation with dipyridamole (0.142 mg/kg/min for 4 minutes). A coronariography was performed in 338 patients (57%). The frequency of clinical and electrical positivity and their relationship with the MPS and the coronariography were studied. RESULTS: The rate of angina and ST depression was 32% (n = 190) and 10% (n = 58), respectively. Myocardial perfusion defects were observed in 465 patients (78%), and signs of scintigraphic ischemia in 311 (52%). The patients with ST depression presented a higher frequency of perfusion defects (93% vs 76%, p = 0.0012) and scintigraphic ischemia (89% vs 49%, p < 0.0001). In addition, perfusion defects in more than one territory were observed in these patients in a higher percentage (53% vs 34%, p = 0.0036). Among the patients who underwent cardiac catheterization, those who had a ST depression had a greater extension of coronary heart disease (1.8 +/- 1.2 vs 1.3 +/- 1.0 diseased vessels, respectively. p = 0.0100) and a higher frequency of multivessel disease (61% vs 43%, p = 0.0380). Those patients who had clinical positivity showed a scintigraphic ischemia more frequently (66% vs 47%, p < 0.0001), however no statistically significant differences were observed between the presence of patients with perfusion defects or in the extension of these defects as well as in the number of diseased vessels in the coronariographic study. CONCLUSIONS: During the administration of dipyridamole, the ST depression is associated with more frequent scintigraphic ischemia, larger extension of perfusion defects and more diseased vessels. The appearance of angina is associated with scintigraphic ischemia, but it is not necessarily associated with the extension of perfusion defects or greater number of diseased vessels.

Angina Pectoris↗
PubMed2000

[Results of myocardial scintigraphy with 99mTc-tetrofosmin and dipyridamole administration in patients diagnosed of microvascular angina].

The objective of the study was to evaluate the results of the myocardial scintigraphy with 99mTc-tetrofosmin (Tc-Tf) and pharmacological stimulation with dipyridamole in patients diagnosed of microvascular angina. The study population is made up of 50 patients discharged with the diagnosis of microvascular angina who had undergone Tc-Tf-dipyridamole. Clinical and electrical positivity appeared in 40% and 12% of the patients, respectively. Myocardial perfusion defects were found in 35 patients (70%), and were reversible in 21 (60%), fixed in 11 (21%), and combined in 3 (9%). Abnormalities were inferior, anteroseptal and lateral in 21, 18, and 2 patients, respectively. Patients with a positive exercise treadmill test, compared with those with a negative one, had more frequent perfusion abnormalities (91% vs 50%, p = 0.0327) and myocardial ischemia (64% vs 20%, p = 0.392). Women, in comparison with men, had angina (56% vs 22%, p = 0.013), and anteroseptal perfusion abnormalities (26% vs 4%, p = 0.028) more frequently. On the contrary, men had inferior perfusion abnormalities more frequently (57% vs 30%, p = 0.057). Thus, Tc-Tf-dipyridamole shows perfusion abnormalities in 70% of patients with microvascular angina (91% in patients with a positive exercise treadmill test). Scintigraphic pattern may be partially conditioned by gender in these patients.

Coronary Circulation↗
PubMed2000

[Bone scintigraphy findings in patients with recently diagnosed adenocarcinoma of the prostate: relationship with prostate specific antigen levels].

BACKGROUND AND OBJECTIVES: Although it has been suggested that bone scintigraphy (BS) may not be necessary in patients with prostate adenocarcinoma (PA) and normal prostate specific antigen (PSA) plasma levels, controversy still remains. The objective of the study was to evaluate the existing relationship between PSA plasma levels and BS findings in patients with a recently diagnosed PA in order to assess whether BS may be omitted on the basis of the PSA levels in these patients. METHODS: The 475 patients (70+/-7 years old) consecutively diagnosed of PA between 1994 and 1998 in our institution made up the study population. PSA plasmatic levels were determined and BS was performed (body planar study after 99mTc-methyl diphosphonate 900 MBq administration) in all the patients. RESULTS: In 362 patients (76.2%), BS was negative, in 108 (22.7%) positive and undetermined in the remaining 5 patients (1.1%). The mean PSA level in the whole study population was 74+/-267 ng/ml (range 0.4-4.200) and was higher in patients with positive GO (218+/-512 vs 31+/-89, p<0,0001). As PSA increased, the rate of patients with positive BS was significantly higher, this being 0%, 16.4%, 9.7%, 14.0%, 31.0% and 48.3% in patients with PSA 4, 4.1-10; 10.1-20; 20.1-30; 30.1-40, and >40 ng/ml, respectively (p<0.0001). In patients with positive BS, the PSA levels were 20 and 10 ng/ml in 30.6% and 18.6% of the patients, respectively. CONCLUSION: According to our experience, there is a significant association between PSA plasma levels and the BS results in patients with recently diagnosed PA. However, a significant proportion of patients with bone metastasis have normal PSA levels, and therefore BS should be performed in all patients with recently diagnosed PA regardless of the PSA levels.

Aged↗
PubMed2000

[Usefulness of spect with 99mTc-tetrofosmin and stimulus with dipyridamole in patients with left bundle branch block of His].

BACKGROUND: In patients with left bundle branch block, the 201Tl scintigraphic studies show high sensitivity, but with low specificity, in the diagnosis of coronary artery disease. OBJECTIVE: [corrected] To assess the value of 99mTc-tetrofosmin Single Photon Emission Computed Tomography (SPECT) and dipyridamole administration in patients with left bundle branch block. METHODS: 22 patients with angina and left bundle branch block were retrospectively studied by cardiac catheterization and Tc-Tf after dipyridamole administration (0,142 mg/kg/min. i.v.) and at rest. RESULTS: The mean number of territories with perfusion defects was 1.5+/-1.0, and the average number of diseased vessels in the coronariographic study was 1.6+/-1.3 (r = 0.77, p<0.001). Sensitivity, specificity, positive predictive value, negative predictive value, total predictive value and Kappa index in the diagnosis of multivessel disease were 92%, 90%, 92%, 90%, 91% and 0.82, respectively. In the diagnosis of anterior descending artery disease, these values were 83%, 70%, 77%, 78%, 77%, and 0.54, respectively. CONCLUSION: In patients with angina and left bundle branch block, SPECT with Tc-Tf-dipyridamole is of great value in the study of coronary artery disease extension. Sensitivity and specificity for the diagnosis of anterior descending artery disease were similar to that shown in series with thallium-dipyridamole.

Bundle of His↗
PubMed1999

Bilateral massive edema of the ovary.

We present a case of synchronic bilateral ovary mass edema. In spite of the patient's age and the difficulties of the intraoperative study it reveals a high likelihood of malignancy in the preoperative stage.

Adult↗
PubMed1999

[Scintigraphy diagnosis of renovascular hypertension in renal transplanted patients].

UNLABELLED: Captopril renography (CR) has been shown to be a useful technique in the diagnosis of renovascular hypertension (RVH). This disease is a significant complication of the kidney transplanted patient so that early diagnosis would be extremely useful to preserve renal function and prevent graft loss. This work evaluates the role of CR, together with arteriography and doppler-ultrasound, in the diagnosis of RVH. MATERIALS: A total of 19 transplanted patients with clinical suspicion of RVH underwent an isotopic study, a doppler-ultrasound study and an arteriography. Scintigraphy was performed 1 hour after a 50 mg dose of captopril, with oral hydration and i.v. administration of approximately 111 MBq of 99mTc-MAG3 and 20 mg of furosemide. If abnormal, a subsequent renography in baseline conditions was performed for comparison. RESULTS: Overall, 11 patients had renovascular hypertension. Sensitivity and specificity of CR were 91% and 80% respectively, 100% and 60% for US and 91% and 100% for arteriography. The CR yielded one false positive result and 2 false negatives cases: one with 50% stenosis and one polar artery stenosis. Six patients were successfully dilated or operated. CONCLUSION: CR seems to be a reliable diagnostic tool for the diagnosis of renovascular hypertension in kidney transplanted patients.

Adult↗
PubMed1998

[Kinetic assessment of salivary secretory response to citric acid. Differences with pilocarpine].

BACKGROUND: Induction of salivation is becoming increasingly popular in the assessment of salivary gland status. Various mechanical or pharmacological procedures are empirically used to produce salivation. Oral stimulation by citric acid (AC) is by far the most used sialagogue procedure. AIM: To characterize the salivary secretory response to AC solutions applied to the dorsolateral tongue surfaces. SUBJECTS AND METHODS: Young healthy women from the upper levels of a medical career (n = 19) participated as volunteers. Salivary volume and UV-absorbing organic material in saliva from single subjects were measured after various protocols of topical stimulation by AC. RESULTS: After a single stimulation by 1-8% AC the salivary flow rate peaked before 30 seconds and recovered the basal level earlier than 2 minutes. Repetitive stimulations at 30-sec intervals kept the flow rate at a maximum. After suspending these stimulations, basal flow rate was recovered before 2 minutes. Repetitive AC-stimulations at 8-min intervals produced a series of identical and independent secretory responses. The concentration of organic material in saliva remained unaltered after the various modes of stimulation. Thus, the profile of organic material secretion was always a direct expression of changes in salivary flow rate. In contrast to AC, the oral administration of the cholinergic agonist pilocarpine (PIL) produced a two-wave salivary response that as a whole lasted for about 30 minutes. In this case the volume and the amount of organic material were at least 10-fold the ones secreted in response to AC. CONCLUSIONS: AC provoked a rapid and short-lived salivary response that differs markedly from the one produced by other secretagogues, like pilocarpine.

Adult↗
PubMed1998

Technetium-99m-HMPAO in Tourette's syndrome on neuroleptic therapy and after withdrawal.

UNLABELLED: Both decreased and increased perfusion and metabolism have been described with PET and SPECT in different areas of the brain in patients with Gilles de la Tourette's syndrome. The aim of this study was to define the regional cerebral perfusion pattern in drug-free patients and the changes in perfusion with the usual neuroleptic treatment. METHODS: A group of 13 normal control subjects and 15 unmedicated Gilles de la Tourette's syndrome patients were studied with 99mTc-HMPAO brain SPECT. Thirteen of the initial group of patients were retested on neuroleptic treatment. A semiquantitative analysis of the images was performed. RESULTS: Decreased perfusion in orbital and anterior medial regions of both frontal lobes as well as in both temporal lobes was observed in the nontreated group compared with control subjects. With treatment, a perfusion increase in these frontal regions and in the left medial temporal cortex was observed. CONCLUSION: Neuroleptic treatment could decrease the hyperactivity of the dopaminergic system leading to improvement of the clinical symptoms and reperfusion of some previously hypoperfused regions.

Adolescent↗
PubMed1998

[Integration of multimodal medical images].

Multimodality analysis is becoming a required tool in medical practice due to the development of different image techniques and new imaging processing tools. This paper is a review of the basis of medical image integration, image fusion techniques, and their clinical applications, especially addressing our experience with brain tomographic studies in nuclear medicine and radiology.

Algorithms↗
PubMed1998

[Devices for saliva collection from the major salivary glands. Results in normal subjects].

BACKGROUND: Collection of saliva produced by the major salivary glands may be accomplished either by cannulation of the glandular ducts or by the application of specific collecting devices to the emergence area of the glandular ducts. Those procedures are complex, slow, invasive and require skilled personnel. AIM: To report the design and application of a device to collect parotid saliva (snail collector) and another device to collect saliva from the submandibular/sublingual complex. MATERIAL AND METHODS: The saliva collection devices were tested in 40 healthy volunteers (20 male) aged 18 to 22 years old. Saliva was collected using conventional conditions, during 5 to 15 min. RESULTS: An average of 1 to 1.5 ml of saliva was collected in the 10-15 min period from both parotid and submandibular/sublingual glands. Flow rates from parotid glands were 80 microliters/min and 180 microliters/min from submandibular/sublingual glands. Parotid saliva had a protein and organic material concentration twice as high than saliva from submandibular/sublingual glands. The presence of human alpha-amylase duplet (Mr 55 kD and 58 kD) predominated in parotid saliva, whereas saliva from submandibular/sublingual glands had other molecular markers such as the lysozyme duplet (Mr 18.5 kD and 17 kD). CONCLUSIONS: The tested devices were easily applicable, comfortable and allowed the collection of both parotid saliva and submandibular/sublingual saliva from various subjects at once, under the supervision of a single professional.

Adolescent↗
PubMed1998

Clinical, histopathological, cytogenetic and prognostic differences between mucinous and nonmucinous colorectal adenocarcinomas.

OBJECTIVE: To assess the clinical and biological significance of histological typing of colorectal carcinomas. PATIENTS AND METHODS: The retrospective analysis of 142 consecutive patients who underwent surgical resection of a mucinous (MC; n = 27; 19%) or a nonmucinous (nMC; n = 115; 81%) colorectal adenocarcinoma was carried out. The two groups were compared in terms of the clinical features, p53 gene expression (antiserum CM1), proliferating cell nuclear antigen (PCNA) labeling index, DNA ploidy (by flow cytometry), histopathological features, prognosis and recurrence rate. RESULTS: The two types of tumors differed with respect to patient age, location, morphology, pattern of genetic lesions and type of tumor recurrences. Twenty-five percent of the patients with MC and 9% of those with nMC (p = 0.04) were under 50 years of age. The incidences of right MC and left MC were similar, while the majority of the nMC were located on the left side (p = 0.04). The MC were of higher grade and their margins more infiltrative than those of the nMC (p = 0.001 and p = 0.01, respectively), p53 nuclear staining was observed less frequently in the MC than in the nMC (30% vs 55%; p = 0.03). The PCNA labeling index was higher in the nMC (46% vs 21%; p = 0.05). We observed no significant differences with respect to tumor stage, incidence of vascular invasion or prevalence of lymphocytic infiltration. The prognosis was similar in both groups, although their recurrence patterns differed, with a tendency toward locoregional recurrence in the cases of MC. CONCLUSION: These findings suggest that, despite their similar prognoses, these two types of lesions are epidemiologically, phenotypically and genotypically different and, thus, result from distinct carcinogenic pathways.

Adenocarcinoma↗