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M Teixidó

Publications and source records attributed to M Teixidó.

15 recordsLinked to original sources
PubMed2005

Solid-phase synthesis and characterization of N-methyl-rich peptides.

A library of peptides required for a project investigating the factors relevant for blood-brain barrier transport was synthesized on solid phase. As a result of the high N-methylamino acid content in the peptides, their syntheses were challenging and form the basis of the work presented here. The coupling of protected N-methylamino acids with N-methylamino acids generally occurs in low yield. (7-azabenzotriazol-1-yloxy)-tris(pyrrolidino)phosphonium hexafluorophosphate (PyAOP) or PyBOP/1-hydroxy-7-azabenzotriazole (HOAt), are the most promising coupling reagents for these couplings. When a peptide contains an acetylated N-methylamino acid at the N-terminal position, loss of Ac-N-methylamino acid occurs during trifluoroacetic acid (TFA) cleavage of the peptide from the resin. Other side reactions resulting from acidic cleavage are described here, including fragmentation between consecutive N-methylamino acids and formation of diketopiperazines (DKPs). The time of cleavage is shown to greatly influence synthetic results. Finally, high-performance liquid chromatography (HPLC) profiles of N-methyl-rich peptides show multiple peaks because of slow conversion between conformers.

Acetylation↗
PubMed2002

Quantification of foetomaternal haemorrhage. An analysis of two cytometric techniques and a semiquantitative gel agglutination test.

Traditional tests to screen for foetomaternal haemorrhage are time-consuming and difficult to perform. The Kleihauer test is widely used but difficult to standardize. We evaluated three techniques for quantifying foetomaternal haemorrhage: a semiquantitative gel agglutination test and two flow cytometric techniques. The gel agglutination test is based on the consumption of anti-D reagent by D+ cells, analysing the reaction of the supernatant against indicator cells in a Coombs-gel card. In the two colour direct immunofluorescent technique, the sample is incubated with Per-CP labelled anti CD45 antibody, fixed with glutaraldehyde and permeabilized by exposure to Triton X-100. An aliquot is stained with an antibody to foetal haemoglobin, conjugated with fluorescein isothiocyanate or phycoerythrin. The indirect immunofluorescent technique is based on the labelling of Rh (D) antigen with an anti D reagent, followed by the addition of an anti IgG antibody conjugated with phycoerythrin. Foetomaternal haemorrhage was not detected in 75 of the 85 samples analysed by the direct immunofluorescent technique. In the remaining 10 samples, the volume was very low. Thirty-five samples with Rh (D) antigen incompatibility were analysed in parallel by the indirect immunofluorescent technique and in 15 of the 35 samples, the gel agglutination technique was also carried out. The three techniques gave similar results. The gel agglutination test can be used to screen for foetomaternal haemorrhage, while greater volumes should be quantified by flow cytometric techniques.

Agglutination Tests↗
PubMed1998

[Duodenal duplication].

Cystic duplication of the duodenum is a rare anomaly of the gastrointestinal tract. This is a report of a newborn with a cystic duplication of duodenum diagnosed prenatally. It's relevant the few clinical symptoms of a such big mass. The surgical procedure was excision of the cyst, with a good post operative curse.

Duodenum↗
PubMed1997

Anti-beta 2-glycoprotein I antibodies: a useful marker for the antiphospholipid syndrome.

We studied anti-beta 2-glycoprotein I antibodies (a beta 2GPI) in autoimmune disease patients to evaluate their relationship to clinical findings. Seventy-nine systemic lupus erythematosus (SLE) patients [44 with antiphospholipid antibodies (aPL)], 21 with primary antiphospholipid syndrome (APS), eight asymptomatic individuals with aPL and 60 controls were studied. Sixteen SLE patients (14 with aPL and two without aPL) and six with primary APS had a beta 2GPI. A significant relationship was found between a beta 2GPI and aPL (P < 0.01). In SLE, a significant correlation was found between previous thrombosis or thrombocytopenia and a beta 2GPI or a beta 2GPI + aPL, but not between fetal losses and a beta 2GPI. These data suggest that a beta 2GPI may be useful in the study of APS.

Adult↗
PubMed1996

Antibodies to endothelial cells and to beta 2-glycoprotein I in the antiphospholipid syndrome: prevalence and isotype distribution.

The aim of this study was to analyse the prevalence and isotype distribution of antibodies to endothelial cells (aEC) and to beta 2-glycoprotein I (a beta 2GPI) in the antiphospholipid syndrome (APS). Fifteen patients with an APS [nine associated with systemic lupus erythematosus (SLE) and six "primary'] and 15 with SLE without an APS were prospectively studied. The aEC were determined by an enzyme-linked immunosorbent assay (ELISA) using endothelial cells derived from human umbilical vein and the a beta 2GPI by ELISA using highly purified beta 2GPI. A positive titre of aEC was detected in 20 out of 30 patients (67%), but in none of the control group. Ten patients had both IgG and IgM isotypes, five had IgG only and five had only IgM. Thirteen patients with the APS (87%) were found to have a positive titre of aEC, while only seven with SLE but without a history of APS (47%) had aEC (P < 0.05). Nine patients with the APS (60%) had a positive titre of a beta 2GPI (four had both IgG and IgM isotypes, one had IgG only and four had only IgM), while none of the patients without an APS (0%) had these antibodies (P < 0.001). A significant association was also found between the presence of aPL and aEC (P < 0.05), as well as between aPL and a beta 2GPI (P < 0.001). Both aEC and a beta 2GPI can be found in the APS. This reinforces the theory that APS represents a complex autoimmune disorder in which several autoantibodies co-exist with aPL.

Adult↗
PubMed1993

Chronic liver disease: comparison of ultrasound patterns with laparoscopy and biopsy.

We studied the correlation of ultrasound patterns with laparoscopy and biopsy results in 140 patients with chronic liver disease (CLD). Of the 23 patients with a normal ultrasound pattern (N), biopsies revealed CLD in 18; in the 22 patients with unspecified hepatomegaly (H), biopsies disclosed CLD in 20; and in the 64 patients with a homogeneous bright pattern (HB), biopsies showed CLD in 62. All 22 cases of heterogeneous bright pattern (HTB) and all 9 patients with nodular pattern (ND) had CLD. In conclusion, it appears that the HTB and nodular ultrasound patterns confirm the presence of CLD, the HB pattern is suggestive of CLD, but diagnosis of CLD cannot be made from N and H patterns.

Adult↗
PubMed1992

Systemic prostacyclin in cirrhotic patients. Relationship with portal hypertension and changes after intestinal decontamination.

The total body production of prostacyclin was shown to be increased in cirrhotic patients, suggesting that its synthesis by blood vessels of the systemic circulation is enhanced. However, the mechanism by which the synthesis of systemic prostacyclin is stimulated is not known. The present study investigated the urinary excretion of 2,3-dinor-6-keto-PGF1 alpha, an index of total body prostacyclin synthesis, first, in cirrhotics with portal hypertension (n = 19) as compared with cirrhotics with reduced portal pressure after portacaval shunt surgery (n = 18) and with control noncirrhotic subjects (n = 11), and; second, in cirrhotics before and after intestinal decontamination by oral nonabsorbable antibiotics (n = 9 antibiotic treated patients, n = 10 control nontreated cirrhotics). Control noncirrhotic subjects showed lower urinary excretion of 2,3-dinor-6-keto-PGF1 alpha than both groups of cirrhotics (P less than 0.001). Interestingly, urinary excretion of 2,3-dinor-6-keto-PGF1 alpha was significantly higher in cirrhotics with portacaval shunt than in those with portal hypertension (P less than 0.01). The urinary excretion of 2,3-dinor-6-keto-PGF1 alpha decreased significantly after intestinal decontamination in the antibiotic-treated group (580.1 +/- 232.4 vs. 431.2 +/- 219.2 pg/mg creatinine; P less than 0.05) but not in nontreated patients (543.9 +/- 214.4 vs. 581.2 +/- 281.4 pg/mg creatinine; P = NS). These data suggest that the increased urinary excretion of 2,3-dinor-6-keto-PGF1 alpha observed in cirrhotics is not directly related to portal hypertension itself but to portal blood factors that bypass the liver. Some such factors may be of intestinal bacterial origin.

6-Ketoprostaglandin F1 alpha↗
PubMed1991

[Vaccination against the hepatitis B virus in alcoholics].

BACKGROUND: The risk of hepatitis B virus infections is high among alcohol abusers, and vaccination has been evaluated in previous studies. However, the response has been low with the usual doses and schedules. METHODS: In the present controlled trail a group of 14 alcohol abusers was vaccinated following a rapid schedule with a dose twice the usual one. Their response was compared to that of a second group of 16 alcohol abusers vaccinated in the usual way. Both groups were compared to a third one consisting of 30 healthy individuals. RESULTS: At the end of the program 83% of the healthy controls responded, with a mean anti-HBs titer of 1130.3 mU/ml. The anti-HBs titer achieved in both groups of alcohol abusers was lower that in healthy individuals (p less than 0.05). 56% of the alcohol abusers vaccinated with the usual program responded (with a mean titer of 80.1 mU/ml), and so did 66% of those vaccinated with high doses (mean titer 63.3 mU/ml). CONCLUSIONS: These results indicate that the poor response of alcohol abusers to HBV vaccine does not improve with increased doses and a rapid schedule.

Adult↗
PubMed1991

Selective intestinal decontamination prevents spontaneous bacterial peritonitis.

In a prospective randomized study, selective intestinal decontamination with norfloxacin was performed during hospitalization in 32 cirrhotic patients with low ascitic fluid total protein levels. The incidence of infections was compared with that in a control group of 31 nontreated cirrhotic patients of similar characteristics. We found a significantly lower incidence of infections [1/32 (3.1%) vs. 13/31 (41.9%); P less than 0.005] and spontaneous bacterial peritonitis [0/32 (0%) vs. 7/31 (22.5%); P less than 0.05] in patients receiving norfloxacin. The lower incidence of extraperitoneal infections [1/32 (3.1%) vs. 7/31 (22.5%); P = 0.052] in the treated group did not reach statistical significance. The incidence of infections [1/28 (3.6%) vs. 9/22 (40.9%); P less than 0.01] and spontaneous bacterial peritonitis [0/28 (0%) vs. 5/22 (22.7%); P less than 0.05] in cirrhotic patients admitted because of ascites was also significantly lower in the treated group. The decrease in the rate of mortality observed in the group undergoing selective intestinal decontamination did not reach statistical significance. These data show that selective intestinal decontamination is useful to prevent spontaneous bacterial peritonitis and extraperitoneal infections in hospitalized cirrhotic patients with low ascitic fluid total protein levels.

Aged↗
PubMed1991

[An analysis of hospital bacterial infections in cirrhotic patients undergoing selective intestinal decontamination].

Cirrhotic patients with ascites and low levels of ascitic fluid C3 and total protein and cirrhotic patients with gastrointestinal hemorrhage are at high risk of infection. Selective intestinal decontamination with oral norfloxacin is useful to decrease the incidence of infections in cirrhotic patients at high risk. This study analyzes hospital acquired bacterial infections in cirrhotic patients with ascites and low levels of total protein in ascitic fluid (n = 53) and cirrhotic patients with gastrointestinal hemorrhage (n = 26), both submitted to selective intestinal decontamination with norfloxacin during the hospitalization. Seven patients developed eight infections (8.8%): three patients with ascites and low levels of total protein in ascitic fluid and four patients with gastrointestinal hemorrhage (5.6% vs 15.3%, pNS). Gram negative bacilli were not isolated in any case, but Gram positive cocci were isolated in seven cases. These results suggest that Gram positive cocci must be empirically covered when infection is suspected in cirrhotic patients submitted to selective intestinal decontamination. The analysis of antibiograms in these infections showed a high sensitivity of Gram positive cocci to amoxycillin and clavulanic acid, which could be used as empirical treatment when infection is suspected in these patients.

Ascites↗
PubMed1990

Selective intestinal decontamination increases serum and ascitic fluid C3 levels in cirrhosis.

Selective intestinal decontamination for 7 days with norfloxacin was performed in 14 cirrhotic patients with ascites and low ascitic fluid total protein. Variations in serum and ascitic fluid of C3 and C4 and ascitic fluid total protein after therapy were compared with those of a control group of 14 untreated patients with similar characteristics. After oral norfloxacin administration, we saw a significant increase of C3 in serum (p less than 0.05) and ascitic fluid (p = 0.01). A significant increase was also observed in ascitic fluid total protein (p less than 0.05) but not in serum and ascitic fluid C4. There were no changes in serum C3, ascitic fluid C3, ascitic fluid C4 or in ascitic fluid total protein in group 2. These data demonstrate that selective intestinal decontamination increases serum and ascitic fluid C3 levels and, therefore, might be useful in preventing spontaneous infections in cirrhotic patients at high risk of infection.

Ascitic Fluid↗
PubMed1990

[Spontaneous bacterial peritonitis: a comparative study of 2 methods of ascitic fluid culture].

The sensitivity in the diagnosis of spontaneous bacterial peritonitis of ascitic fluid inoculation in blood culture bottles has been compared with the conventional method. We have analyzed 74 positive ascitic fluid cultures from 64 patients, the samples being processed by both techniques simultaneously. While all the ascitic fluid cultures performed by inoculation in blood culture bottles were positive, in only 42 from the 74 conventional cultures (56, 75%) bacterial growth was detected (p less than 0.001). Nineteen bacterascites were diagnosed by inoculation in blood culture bottles and 10 by the conventional method (p = NS). Gram stain was only positive in 3 spontaneous bacterial peritonitis (6%). We conclude that ascitic fluid inoculation in blood culture bottles improves significantly the sensitivity of the microbiological diagnosis of spontaneous bacterial peritonitis, without increasing the diagnosis of bacterascites.

Ascitic Fluid↗
PubMed1989

[Variation of C3 in ascitic fluid from cirrhotic patients subjected to intestinal sterilization or selective intestinal decontamination].

Patients with liver cirrhosis with ascites and low levels of C3 and Total Proteins in ascitic fluid show a greater predisposition to the development of spontaneous bacterial peritonitis. The variation of C3 and Total Proteins levels in ascitic fluid in two groups of patients with liver cirrhosis was studied. Group I (n = 14) underwent intestinal sterilization (n = 7) or selective intestinal decontamination (= 7). Group II was a control. A statistically significant increase in C3 (p less than 0.01) and Total Proteins (p less than 0.015) levels in ascitic fluid in Group I patients was found. There were no changes in the control group. The incidence of side effects was higher in those patients who underwent intestinal sterilization. Our results suggest that selective intestinal decontamination may be useful as a prophylactic measure against spontaneous bacterial peritonitis in those patients with liver cirrhosis at high risk of infection by increasing the bactericidal capacity of ascitic fluid.

Adult↗