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Biomedical subjects

J M Segura

Publications and source records attributed to J M Segura.

At least 19 recordsLinked to original sources
PubMed2000

Allergy to drugs: antioxidant enzymic activities, lipid peroxidation and protein oxidative damage in human blood.

Reactive oxygen species lead to lipid peroxidation and specific oxidation of some specific enzymes, proteins and other macromolecules, thus affecting many intra- and intercellular systems. Recently, antioxidant functions have been linked to anti-inflammatory properties. Cell defences against toxic oxygen include antioxidant enzymes. We studied the enzymic antioxidant capacity in human blood of both erythrocytes and mononuclear cells from patients suffering from an allergic reaction to different drugs. We determined superoxide dismutases (SODs), glutathione peroxidase (GSHPx) and catalase (CAT) activities in each cell type. We also determined the extent of thiobarbituric acid reactive substances (TBARS) and the oxidative damage to proteins, in order to study the correlation between the cellular enzymic activities, the oxidative status and the allergic reaction. In mononuclear cells from allergic patients, SODs and CAT activities were enhanced compared with controls. Conversely, a decrease in GSHPx activity was found. In erythrocytes, higher values for CAT, GSHPx and SODs activities were found in allergic patients. TBARS were also enhanced in both types of cells, and the carbonyl content of serum was equally increased. The respective enzymic imbalances in mononuclear cells and erythrocytes, namely, GSHPx/SOD and CAT/SOD, and their consequences are discussed. To our knowledge, this is the first global study of antioxidant enzyme determinations, including TBARS level and carbonyl content, in patients suffering from allergies to drugs.

Adolescent↗
PubMed2000

Utilization of screening mammography as a preventive practice prior to initiating a population-based breast cancer screening program.

Factors associated with the level of utilization of screening mammography as a preventive practice were analyzed prior to initiating a population-based breast cancer screening program. A questionnaire was used to collect information about screening mammography utilization during the last 4 years among women invited to enroll in the program. Sociodemographic and health factors, and health services utilization were studied. A screening mammography in the last 4 years had been performed on 59.3% of the 8867 women interviewed. The utilization of mammography was higher among women who were younger, had a higher education level, or had previous visits to a physician (P < 0.001). The variables more strongly associated with use of screening mammography were: visit to a gynecologist and performance of a pap smear. Also associated with the utilization of screening mammography were: personal history of breast pathology, family history of breast cancer, breast self-examination, and recent visit to a general practitioner. Self-perceived health presented an inverse relation with screening mammography use (P < 0.001). The use of screening mammography appears to have increased in recent years, although inequalities persist which the breast cancer screening programs help to modulate. Mammographic frequency only would be deemed appropriate by the European guidelines in fewer than one-half of the cases.

Breast Neoplasms↗
PubMed1999

Antioxidant enzymatic activities in human blood cells after an allergic reaction to pollen or house dust mite.

Several diseases have been related to oxidative stress. Recently, antioxidant functions have also been linked to anti-inflammatory properties. Cell defenses against reactive oxygen species include antioxidant enzymes. We studied the enzymatic antioxidant capacity in human blood of both red blood and mononuclear cells from patients suffering from an allergic reaction to pollen or house dust mite. We determined superoxide dismutases (SODs), glutathione peroxidase (GSHPx) and catalase (CAT) activities in each cell type. We also determined the extent of thiobarbituric acid reactive substances (TBARS), in order to study the correlation between the cellular enzymatic activities, the redox status and the disease. In mononuclear cells from allergic patients, SODs and CAT activities were enhanced compared to controls. Conversely, a decrease in GSHPx activity was found. In erythrocytes, higher values for GSHPx and SODs and similar CAT activities were found in allergic patients and controls. Interestingly, CuZnSOD and MnSOD activities were enhanced in the same proportion for both, erythrocytes and mononuclear cells. TBARS were also enhanced in both types of cells. The respective enzymatic imbalances in mononuclear cells and erythrocytes, namely, GSHPx/SOD and CAT/SOD, and their consequences are discussed. To our knowledge, this is the first global study of antioxidant enzymes, including TBARS level determinations, in allergy.

Adult↗
PubMed1998

Hidrocolonic ultrasonography in the detection of tumoral processes in the inferior gastrointestinal tract.

OBJECTIVES: To determine the value of hidrocolonic ultrasound in the detection of proliferative lesions in the colon and to compare it with other techniques of already proven value. MATERIAL AND METHODS: We performed a prospective blinded trial including 155 patients (82 males and 73 females) with ages ranging from 33 to 94 years (average of 58) and clinical and analytical criteria suggesting the existence of colonic proliferative lesions. Patients with rectal mass or those with deficient bowel preparation were excluded. Ultrasound findings were compared to those obtained by colonoscopy (133 cases) and by Barium RX studies (22 cases) and all diagnoses were always confirmed by histologic exams. RESULTS: 155 patients were studied. 50 of them had cancer and 46 of these 50 were diagnosed by Hidrocolonic Ultrasound (92%); 19 had polyps > 7 mm. and 15 of these (78.9%) were diagnosed by Hidrocolonic Ultrasound. Hidrocolonic Ultrasound failed to detect all the polyps < 7 mm. The overall sensitivity, specificity, positive predictive value and negative predictive value for identifying colon carcinoma were 92%, 98%, 95.8% and 96.2% respectively and for polyps > 7 mm were 78.9%, 100%, 100% and 97.1%, respectively. The mean time for examination was 14 minutes. Tolerance was good in 114 patients (73.5%), 29 showed a slight discomfort (18.7%) and 12 (7.7%) showed a great discomfort. There were no complications. CONCLUSIONS: Hidrocolonic ultrasound is an innocuous, fast, well tolerated technique for detecting colonic proliferative lesions > 7 mm H.U. can be considered as a useful complementary technique to other more expensive and invasive ones, such as barium RX studies and Colonoscopy.

Adenoma, Villous↗
PubMed1995

[Abdominal echography in patients with human immunodeficiency virus (HIV) infection. Diagnostic usefulness in the evaluation of associated medico-surgical pathology].

BASIS: The abdominal manifestations in the patient with HIV infection are increasingly frequent. We have conducted the present study in order to determine the diagnostic usefulness of the abdominal echography in the clinical assessment of the patient. MATERIALS AND METHODS: We review the echographic findings of 112 patients carrying the HIV with or without the Acquired Immunodeficiency Syndrome (AIDS). Seventy eight patients were men and 34, women, with an average age of 30 years. The main risk group was parenterally drug addiction (72%). The stage of the HIV infection was IVC1 in 41% of the cases, II in 23%, III in 13% and IVC2 in 13%. The echographic exploration was performed using a real-time echography, with a probe of 3.5 Mhz, assessing according to conventional criteria the abdominal organs and their pathology, masses and free intraabdominal fluid. The echographic characteristics were first broadly assessed in the patients from the series and later on, according to the patient's pathology. (Infectious, acute abdominal, hepatic biochemical disorders, HIV carrier-associated pathology). RESULTS: In 33% of the cases, the echography was normal. Hepatomegaly was the most frequent echographic sign: 56 patients (50%), followed by splenomegaly in 43 patients (38.3%), standing out the affection of the biliary and/or vesicular ductus in 7 patients (6.2%). The echographic findings were not related to the HIV infection stage, nor with the presence of hepatic biochemical disorders. However, the presence of organomegaly (hepatosplenomegaly associated or not to retroperitoneal adenopathies) were more frequent in the group with infectious complication, 33.3% vs 19.6% (p < 0.01), that in the patients without associated infectious processes. In patients with medical or surgical acute abdominal pathology, the echography was diagnostic in 9 out of 10 patients. CONCLUSION: In the HIV patient, the echography allows an specific initial diagnostic assessment, being able in most of the patients with abdominal manifestations to diagnose the causal pathology.

Abdomen↗
PubMed1989

[Diagnosis of choledocholithiasis and residual lithiasis. Ultrasonic postcholecystectomy].

246 patients with proven common bile duct stones at surgery were studied in order to establish the accuracy of ultrasound scanning in detecting choledocholithiasis and to compare the sensitivity of real-time examinations with those performed by a static scanner. The detection of choledocholithiasis by real-time ultrasound was 45.6% compared to 26.3% for the examinations performed with a static scanner. A dilated common bile duct was detected in 83.6% using real-time scanning compared to 70.3% using a static scanner. When the common bile duct was not dilated ultrasound was unable to detect the stones. Real-time ultrasound detected 66.6% of the patients with residual choledocholithiasis compared to 23.5% of patients examined by a static scanner. Our results show that real-time ultrasound scanning is a very useful screening method in detecting choledocholithiasis and residual lithiasis.

Cholecystectomy↗