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Biomedical subjects

L Bonet

Publications and source records attributed to L Bonet.

13 recordsLinked to original sources
PubMed2005

[Small bowel diaphragm disease associated with NSAIDs with histology of neuromuscular and vascular hamartoma. Case report and literature review].

Diaphragm disease (DD) induced by non-steroidal anti-inflammatory drugs (NSAIDs) and neuromuscular and vascular hamartoma (NMVH) are rare entities that can be difficult to recognize clinically, radiologically and pathologically. Both may cause small bowel obstruction and both reveal annular constrictions macroscopically. However, the 2 entities differ in that the constrictions are purely fibrous in DD whereas they have a hamartomatous histopathology in NMVH. We describe the case of a 76-year-old woman with a history of prolonged NSAID use who developed clinical features and gross pathology consistent with DD and histopathology of NMVH.

Aged↗
PubMed2003

[Lactose malabsorption in ulcerative colitis. A case-control study].

BACKGROUND: The role of lactose malabsorption in ulcerative colitis is controversial. The aim of this study was to compare the prevalence of lactose malabsorption in a group of ulcerative colitis patients and a control group and to modify lactose consumption in view of the results. METHODS: Lactose malabsorption was studied using the hydrogen breath test in 52 patients with ulcerative colitis and 34 controls after ingestion of 25 g of lactose. A questionnaire on ingestion of milk products was also administered. RESULTS: Of the 52 patients with ulcerative colitis, 13 (25%) presented lactose malabsorption compared with 11 of the 34 (32%) controls (p = 0.45). Twenty-four patients (46%) had been advised to completely eliminate lactose from their diets. Twenty-seven of the 39 patients without malabsorption had reduced or eliminated lactose consumption after being diagnosed with ulcerative colitis. CONCLUSIONS: No significant differences in the prevalence of lactose malabsorption was found between patients with ulcerative colitis and controls. We believe that systematic elimination of lactose from the diets of these patients is erroneous. In our environment, we recommend the hydrogen breath test only in patients with symptoms of lactose intolerance.

Adolescent↗
PubMed2000

Melatonin attenuates acute renal failure and oxidative stress induced by mercuric chloride in rats.

We evaluated the effect of melatonin (Mel), a potent scavenger of reactive oxygen species, in the course of HgCl(2)-induced acute renal failure. Rats received by gastric gavage 1 mg/kg of Mel (n = 21) or vehicle (n = 21), 30 min before the subcutaneous injection of HgCl(2) (2.5 mg/kg). Rats were killed at 24, 48, and 72 h, and plasma creatinine (S(cr)), renal histology, proliferative activity, apoptosis, and superoxide-producing cells were studied. We also determined the renal content of malondialdehyde (MDA) and glutathione (GSH) and the activities of glutathione peroxidase and catalase. Mel pretreatment (Mel plasma levels of 3.40 +/- 3.15 microgram/ml at the time of HgCl(2) injection) prevented the increment in S(cr) and reduced tubular necrosis from 41.0 +/- 10.5 to 4.2 +/- 5.1% of proximal tubules (P < 0.01). Apoptosis and postnecrotic proliferative activity were twice more intense in the group untreated with Mel. Increment in renal content of MDA and decrease in GSH resulting from HgCl(2) toxicity were prevented by Mel. Mel also induced an important reduction in superoxide-positive cells. In contrast to the beneficial effects of pretreatment with Mel, the administration of Mel in conjunction with HgCl(2) had no effect on the oxidative damage and did not prevent nephrotoxicity. We conclude that the beneficial effects of pharmacological doses of Mel are due to its antioxidant properties.

Acute Kidney Injury↗
PubMed1998

[Celiac disease of the adult following orthotopic liver transplantation. Description of a case].

A case of celiac disease of the adult is herein described in a patient with a history of orthotopic liver transplantation because of cirrhosis due to hepatitis C virus. The patient presented with a decrease in the levels of cyclosporinemia, diarrhea and an increase in transaminases. This is an infrequent form of presentation leading to differential diagnosis with a complication related to the liver disease.

Celiac Disease↗
PubMed1997

[Prevalence of monosymptomatic celiac disease in patients with iron deficiency anemia].

A prospective study of the prevalence of monosymptomatic celiac disease presented as ferropenic anemia in patients admitted for study such complication of was carried out. All the patients were evaluated by gastroscopy and biopsy of the distal duodenal segment, regardless of endoscopic appearance. Patients presenting an endoscopic lesion clearly suggestive as the origin of the chronic bleeding were excluded from the study. The prevalence of celiac disease, the only manifestation of which was ferropenic anemia, was 3.3% in this series. What is important to note in this study is the importance of duodenal biopsy in the study of ferropenic anemia, with the aim of avoiding diagnostic delay of a possible monosymptomatic celiac disease as the cause of the anemia.

Adult↗
PubMed1993

Estimated acid dissociation constants of the Schiff base, Asp-85, and Arg-82 during the bacteriorhodopsin photocycle.

The pK(a) values of D85 in the wild-type and R82Q, as well as R82A recombinant bacteriorhodopsins, and the Schiff base in the D85N, D85T, and D85N/R82Q proteins, have been determined by spectroscopic titrations in the dark. They are used to estimate the coulombic interaction energies and the pK(a) values of the Schiff base, D85, and R82 during proton transfer from the Schiff base to D85, and the subsequent proton release to the bulk in the initial part of the photocycle. The pK(a) of the Schiff base before photoexcitation is calculated to be in effect only 5.3-5.7 pH units higher than that of D85; overcoming this to allow proton transfer to D85 requires about two thirds of the estimated excess free energy retained after absorption of a photon. The proton release on the extracellular surface is from an unidentified residue whose pK(a) is lowered to about 6 after deprotonation of the Schiff base (Zimanyi, L., G. Varo, M. Chang, B. Ni, R. Needleman, and J.K. Lanyi, 1992. Biochemistry. 31:8535-8543). We calculate that the pK(a) of the R82 is 13.8 before photoexcitation, and it is lowered after proton exchange between the Schiff base and D85 only by 1.5-2.3 pH units. Therefore, coulombic interactions alone do not appear to change the pK(a) of R82 as much and D85 only by 1.5-2.3 pH units. Therefore, coulombic interactions alone do not appear to change the pK(a) of R82 as much as required if it were the proton release group.

Arginine↗
PubMed1991

[Early intervention in infants with intrauterine growth retardation: its effects on neuropsychological development].

Forty-eight term infants in a tertiary center in Puerto Rico during 1985-86 were monitored prospectively since birth completing a neuropsychological evaluation using the Mental Developmental Index of Bayley Scales. All infants were free from perinatal complications and chronic diseases by clinical evaluation. 25 infants with intrauterine growth retardation (IUGR) and 23 adequate for gestational age (AGA) infants were evaluated. Fourteen IUGR infants were controls and eleven IUGR infants were intervened. However, all AGA infants were used as controls. Mother-infant relationship at one month was scored and none of intervened infants had poor neuropsychological behavior with normal or near normal MDI values. Other relationships and possible explanations are discussed in the article.

Adult↗
PubMed1990

Influence of diet and obesity on placental amino acid enzyme activities in the rat.

The objective of this study was to assess the impact of dietary obesity and acute starvation on the activity of placental enzymes involved in amino acid metabolism. Twenty-four hours starvation caused a significant fall (10%) in the foetal weight in rats fed standard diet, and this was associated with only modest changes in amino acid enzyme activities. In contrast, in obese rats, foetal weight was unaffected by acute starvation, and was accompanied by a reduced adenylate deaminase activity (24%) and lower ammonia concentrations (50%) in placentae of obese rats after 24h starvation. Thus obesity may confer a protective effect on the foetus growth during acute starvation of diminishing amino acid utilization.

AMP Deaminase↗
PubMed1987

Amino-acid-enzyme activities in brown and white adipose tissues and in the liver of cafeteria rats. Effects of 24 hours starving.

Moderate obesity (17% excess body weight) was induced in female rats by offering a "cafeteria" diet during 82 days. The adaptive changes in five amino-acid-metabolism enzymes were determined in liver and white- and brown adipose tissues by comparison with chow fed controls both in the fed and 24-h starved states. Plasma urea levels were lower in the obese and the changes in enzymatic activities pointed to a lower rate of amino-acid metabolism in our dietary obesity group. The levels of activity of amino-acid-metabolism enzymes in brown adipose tissue were higher than in white adipose tissue and in most cases comparable to that of liver. The importance of amino acids as a fuel source in brown adipose tissue thermogenesis cannot be ruled out.

AMP Deaminase↗