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Biomedical subjects

C Martín

Publications and source records attributed to C Martín.

At least 55 records · Page 3Linked to original sources
PubMed2001

Disparity for the minor histocompatibility antigen HA-1 is associated with an increased risk of acute graft-versus-host disease (GvHD) but it does not affect chronic GvHD incidence, disease-free survival or overall survival after allogeneic human leucocyte antigen-identical sibling donor transplantation.

Disparity for the minor histocompatibility antigen HA-1 between patient and donor has been associated with an increased risk of acute graft-versus-host disease (GvHD) after allogeneic human leucocyte antigen (HLA)-identical sibling donor stem cell transplantation (SCT). However, no data concerning the impact of such disparity on chronic GvHD, relapse or overall survival are available. A retrospective multicentre study was performed on 215 HLA-A2-positive patients who received an HLA-identical sibling SCT, in order to determine the differences in acute and chronic GvHD incidence on the basis of the presence or absence of the HA-1 antigen mismatch. Disease-free survival and overall survival were also analysed. We detected 34 patient-donor pairs mismatched for HA-1 antigen (15.8%). Grades II-IV acute GvHD occurred in 51.6% of the HA-1-mismatched pairs compared with 37.1% of the non-mismatched. The multivariate logistic regression model showed statistical significance (P: 0.035, OR: 2.96, 95% CI: 1.07-8.14). No differences were observed between the two groups for grades III-IV acute GvHD, chronic GvHD, disease-free survival or overall survival. These results confirmed the association between HA-1 mismatch and risk of mild acute GvHD, but HA-1 mismatch was not associated with an increased incidence of chronic GvHD and did not affect relapse or overall survival.

Acute Disease↗
PubMed2001

An essential role for phoP in Mycobacterium tuberculosis virulence.

Two-component regulatory proteins function in bacteria as sensory and adaptive factors in response to a wide range of environmental stimuli. Some two-component systems, such as PhoP/PhoQ, control transcription of key virulence genes essential for survival in host cells in diverse intracellular bacterial pathogens, including Salmonella sp., Shigella sp. and Yersinia sp. In this study, we have disrupted the phoP gene from Mycobacterium tuberculosis, which codes for a putative transcription regulator factor of the two-component system PhoP/PhoR. The phoP mutant strain exhibited impaired multiplication when cultured in mouse bone marrow-derived macrophages. However, the mutation did not appear to affect survival of the organisms adversely inside macrophages. The mutant strain was also attenuated in vivo in a mouse infection model, with impaired growth observed in the lungs, livers and spleens. The results suggest that the phoP gene is required for intracellular growth of M. tuberculosis but is not essential for persistence of the bacilli.

Animals↗
PubMed2001

Characterization of P55, a multidrug efflux pump in Mycobacterium bovis and Mycobacterium tuberculosis.

The Mycobacterium bovis P55 gene, located downstream from the gene that encodes the immunogenic lipoprotein P27, has been characterized. The gene was identical to the open reading frame of the Rv1410c gene in the genome of Mycobacterium tuberculosis H37Rv, annotated as a probable drug efflux protein. Genes similar to P55 were present in all species of the M. tuberculosis complex and other mycobacteria such as Mycobacterium leprae and Mycobacterium avium. By Western blotting, P55 was located in the membrane fraction of M. bovis. When transformed into Mycobacterium smegmatis after cloning, P55 conferred aminoglycoside and tetracycline resistance. The levels of resistance to streptomycin and tetracycline conferred by P55 were decreased in the presence of the protonophore carbonyl cyanide m-chlorophenylhydrazone and the pump inhibitors verapamil and reserpine. M. smegmatis cells expressing the plasmid-encoded P55 accumulated less tetracycline than the control cells. We conclude that P55 is a membrane protein implicated in aminoglycoside and tetracycline efflux in mycobacteria.

Amino Acid Motifs↗
PubMed2001

Assessment of hematologic progenitor engraftment by complete reticulocyte maturation parameters after autologous and allogeneic hematopoietic stem cell transplantation.

BACKGROUND AND OBJECTIVES: Hematopoietic restoration after marrow ablation is initiated by the erythroid compartment. However, the absolute microscope counts or corrected percentage of reticulocytes have proven to be poor markers of hematopoietic engraftment. Some reports have highlighted the usefulness of automatic flow cytometry methods to determine highly fluorescent reticulocytes, or mean fluorescence index. In this series of 60 hematopoietic stem cell transplants, we sought the normal kinetics throughout the post-transplant period of the following reticulocyte maturing parameters: highly fluorescent reticulocytes (RETH), immature reticulocyte fraction (IRF), mean fluorescence index (MFI) and also mean reticulocyte volume (MRV). DESIGN AND METHODS: Sixty consecutive patients undergoing allogeneic bone marrow (30 cases) and autologous mobilized stem cell transplantation (30 cases) were studied. Parameters of reticulocyte maturation were measured every other day from the beginning of the conditioning regimen until myeloid engraftment. RESULTS: Nadir values for the analyzed reticulocyte parameters were found between days +4 and +7 and thereafter, increases in these reticulocyte parameters appeared earlier than the rise in neutrophils. We considered erythroid engraftment to have occurred on the day when RETH reached 3%, IRF 10%, MFI 10 and MRV 110 fL. These cut-offs were assigned considering the 25% quartile for each parameter on the day that the myeloid engraftment occurred. The median engraftment days for RETH were +9 and +16, for IRF +9 and +13, for MFI +9 and +13 and for MRV +11 and +13 in autologous and allogeneic procedures, respectively. When compared to standard neutrophil engraftment, IRF and MFI engraftment occurred significantly earlier in all patients. Remarkably, we found a statistical correlation between the day a reticulocyte parameter reached its cut-off and the subsequent day of absolute neutrophil count (ANC) recovery for MFI after allogeneic transplants and for MRV after autologous procedures (p < 0.001 and p= 0.02, respectively). Of all the clinical parameters tested, only the number of infused CD34 cells showed a statistical influence on erythroid engraftment in autologous transplant. INTERPRETATION AND CONCLUSIONS: Early reticulocytes appear sooner than neutrophils after both autologous and allogeneic transplants, and any determined reticulocyte parameter can reliably measure this fraction. Nevertheless, our results show that MRV and MFI cut-offs are useful for determining subsequent myeloid engraftment. These findings could be relevant to decision-making in those patients with primary graft failure heralded by an absence of increasing values of MFI and MRV, indicating very low production of reticulocytes from the graft, who could, therefore, benefit from earlier rescue therapy.

Adolescent↗
PubMed2000

High rate of tuberculosis reinfection during a nosocomial outbreak of multidrug-resistant tuberculosis caused by Mycobacterium bovis strain B.

We present a study of a nosocomial outbreak of multidrug-resistant tuberculosis caused by Mycobacterium bovis in 31 patients, 30 of whom were infected with human immunodeficiency virus; all 31 died of progressive tuberculosis. All M. bovis strains had identical spoligotyping patterns and showed resistance to 12 antituberculosis drugs. Reinfection was suggested in 11 cases and confirmed in 4 by molecular typing methods. The causative strain was named "B strain."

AIDS-Related Opportunistic Infections↗
PubMed2000

Antioxidant activities of estrogens against aqueous and lipophilic radicals; differences between phenol and catechol estrogens.

Natural estrogens have much greater radical-scavenging antioxidant activity than has previously been demonstrated, with activities up to 2.5 times those of vitamin C and vitamin E. The biological significance of this finding remains to be elucidated. In this work the antioxidant activity of a range of estrogens (phenolic, catecholic and stilbene-derived) has been studied. The activity of these substances as hydrogen-donating scavengers of free radicals in an aqueous solution has been determined by monitoring their relative abilities to quench the chromogenic radical cation 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS*+). The results show that the order of reactivity in scavenging this radical in the aqueous phase is dependent on the precise estrogenic structure, with phenolic estrogens being more potent antioxidants than catecholestrogens or diethylstilbestrol. The ability of the same estrogens to scavenge lipid phase radicals has also been assessed, determined by the ex vivo enhancement of the resistance of low-density lipoprotein (LDL) to oxidation; the order of efficacy is different from that in the aqueous phase, with the phenolic estrogens estriol, estrone and 17beta-estradiol being less potent than 2-hydroxyestradiol, 4-hydroxyestradiol, or diethylstilbestrol. In this lipid-based system, phenolic estrogens were found to be unable to regenerate alpha-tocopherol from LDL subjected to oxidative stress, while at the same time 2- and 4-hydroxyestradiol significantly delayed alpha-tocopherol loss. These results indicate that the various estrogens are good scavengers of free radicals generated in both the aqueous and the lipophilic phases. The antioxidant activity of an estrogen depends not only on the hydrophilic or lipophilic nature of the scavenged radical, but also on the phenol and catechol structures of the estrogen compound.

Antioxidants↗
PubMed2000

[Value of brief questionnaires in predicting smoking cessation in primary care].

OBJECTIVES: 1. To study the factors predicting the giving-up of tobacco and to correlate the categories in the Smoker's Aid Programme (SAP) with levels of motivation and dependency, using brief questionnaires. 2. To find the annual percentage in the "winners" category, using the SAP methodology. DESIGN: Prospective, observational, intervention study without a control group of a random sample of smokers attending primary care clinics. SETTING: Four urban health centres in Zaragoza and Barcelona. INTERVENTIONS: Systematic intervention on smokers in the change phase (SAP category). Use of questionnaires on motivation/dependency and of biochemical checks that they had actually given up. PATIENTS: 362 patients of whom 288 smokers (79.5%) took part. Average age was 40.85 (SD: 15.7). 60.8% were males. MEASUREMENTS AND MAIN RESULTS: 21.4% of the smokers had tobacco-related pathology. The number of previous attempts to give up smoking was 1.6 (SD: 2.9) Patients smoked an average of 13.4 cigarettes for 22.2 years (SD: 15.7). Average age at start of consumption was 17 (SD: 4.7). Initial motivation on the Richmond Test was 4.78 (SD: 3.2); and average dependency according to the modified Fagerström Test (TFm) was 0.6 (SD: 0.7). The number of SAP interventions was 1.9 (SD: 2.9). By the end 15.6% of the patients had achieved "winner" status, which was confirmed in 95.6% of them by the biochemical test. The logistic regression model confirmed that the factors predicting giving up tobacco were age, the initial levels of motivation and the initial number of cigarettes. CONCLUSIONS: The short tests of motivation (Richmond) and, to a lesser extent, dependency (TFm) were good predictors of giving up tobacco and can be recommended in primary care.

Adult↗
PubMed2000

DR2 antigens are associated with severity of disease in toxic oil syndrome (TOS).

Toxic oil syndrome (TOS) was an epidemic which broke out in Spain in 1981, caused by the ingestion of rapeseed oil denatured with 2% aniline and sold illegally as edible oil. More than 20,000 people were affected and mortality rate was 8.4%. Genetic susceptibility appears to be involved in the pathology of this disease. Several reports have described association between the chronic stage of the disease and DR-DQ antigens (DR3, DR4, DR2 and DQ8). In the present work, we have reassessed the HLA class II antigens in a well-designed case-control study. Triplets of subjects (n=265) composed by chronic patients (n=117), non-affected family members (n=71) and non-related controls (n=77) were studied. Also, HLA class II antigens were analyzed in patients who had died from TOS (n= 34) and in TOS control patients who died from other non-TOS related causes (n=13). Regarding surviving patients no significant association was found between HLA and disease. In contrast, an increase in phenotypic frequency of DR2 antigen, was found in patients who had died from TOS (73.5%) compared with the whole study group: TOS-affected alive patients (25.6%, corrected P<0.001), non-affected family members (28.5%, corrected P<0.001), non-related controls (23.9%, corrected P<0.001) and dead controls (38.4%, P=0.03).

Aniline Compounds↗
PubMed2000

Effect of unilateral posterior crossbite on the electromyographic activity of human masticatory muscles.

Studies dealing with the electromyographic activity of masticatory muscles in patients with unilateral posterior crossbite are infrequent. The purpose of this study was to assess the electromyographic pattern of masticatory muscles at rest position, during swallowing, and during mastication, in 30 subjects with right posterior crossbite and to compare them to 30 normocclusive subjects. The 2 groups were matched according to age, gender, skeletal Class I, and mesofacial growth pattern. Electromyographic activity of right and left anterior temporalis, posterior temporalis, masseter, and anterior digastric muscles was recorded at rest position, while swallowing water, and while chewing. Disposable bipolar surface electrodes were used in both groups. Data were compared between groups and between right and left sides within each group. The results revealed that the posterior temporalis of the non-crossbite side was more active than that of the same side in subjects with crossbite at rest position and during swallowing. The activity of both anterior digastrics was higher in the crossbite subjects during swallowing. During chewing the right masseter muscle was less active in the crossbite patients than in normocclusive subjects. The results obtained during chewing indicate a bilateral masticatory pattern in both groups.

Adolescent↗
PubMed2000

Kinesiographic study of the mandible in young patients with unilateral posterior crossbite.

It is generally assumed that children with posterior crossbites have abnormal mandibular movements; however, this assumption has not been clearly evaluated. The purpose of this investigation was to study the movements and the resting position of the mandible in 2 samples of 30 subjects, one aged 10 to 14 years with right posterior crossbite, the other aged 10 to 15 years with normal occlusion. Subjects in both groups exhibited a Class I skeletal relationship and mesofacial growth pattern. A mandibular kinesiograph was used to record both the mandibular resting position and dynamic movements. Mandibular movements were recorded during (1) maximum excursions (opening-closing, protrusion, right and left excursions), (2) swallowing, and (3) mastication. The results showed no differences between groups in the extension of the movements during closing and protrusion. However, crossbite patients exhibited a significant lateral shift during these movements. Right and left excursions were also similar between groups. The dimension of the freeway space was similar between groups, but the lateral shift found in centric occlusion was also present in the crossbite group when the mandible was at rest. The crossbite group more frequently showed a pattern of abnormal swallowing. No differences were found in any of the parameters studied during the masticatory cycle. There was no relationship between the side of the crossbite and the masticatory preference side. In conclusion, posterior crossbite patients showed a lateral shift in some movements that persisted when the mandible was at rest.

Adolescent↗
PubMed2000

Malignant transient pleural transudate: a sign of early lymphatic tumoral obstruction.

In the absence of a responsible comorbid condition, the transudative character of a pleural effusion in patients with malignancy does not imply a favorable outcome. We report a case of colon carcinoma metastatic to lung and pleura presenting as a bilateral transudative pleural effusion. Tumoral diffuse lymphatic permeation was identified as the cause of lymphatic obstruction on pleural and transbronchial biopsies. The transudative character of the pleural effusion was transient denoting its obstructive origin.

Adenocarcinoma↗
PubMed2000

[Study and incidence of carcinoma of the larynx in women].

Recent publications show an increase in the frequency of laryngeal carcinoma in women. Previous studies of patients in our health district (1875-1994) showed a male/female ratio of 56/1. However, a retrospective study of all laryngeal carcinomas diagnosed in a recent year (June 1997-May 1998) showed an overall male/female ratio of 10/1. Women are older at time of diagnosis than men (mean 70.33 years). None of the women was a regular drinker and only one smoked. Glottic location and absence of metastatic lymph node enlargement predominated at time of diagnosis.

Adult↗
PubMed2000

[Effect of the number of samples studied on the diagnosis of tuberculosis].

BACKGROUND: For the microbiological diagnosis of tuberculosis, most standard laboratory guidelines recommend the processing of multiple specimens. This fact added to the nonspecific clinical presentation of many cases, contribute to a low efficiency of the tuberculosis laboratory. The introduction of new procedures have increased the sensibility of the diagnosis and so the cost. The object of our work, was to asses the value of examining 3-6 specimens, in optimizing the diagnosis. METHODS: We retrospectively reviewed 327 specimens from 105 patients with culture-proven tuberculosis, between 1997-1998. All specimens were received in the laboratory within 1 month of the initial diagnosis. RESULTS: Of the 7694 specimens received for acid-fast smear and culture in that period of time, 519 (6.7%) were positive for mycobacteria, many of them without clinical relevance. The average number of specimens processed by patient was 3.1, however 22% of the patients with culture-proven tuberculosis had less than tree specimens submitted at the time of diagnosis and 19% had more than three. In 49.5% of the patients, all the smears were negative and the diagnosis was done by culture. With the first specimen submitted were diagnosed 76% of the patients, and with the second we reach 94.2%, finally, we needed 3 specimens for the diagnosis of 104 from the 105 cases (99%). CONCLUSIONS: With the better sensibility achieved in the detection procedures, the interest in the improvement of the efficiency in the tuberculosis laboratory should consider the contribution of the specimen number on the diagnosis. If studying only one specimen we could fail 25% of the early diagnosis, we have rarely found more than two specimens being of diagnostic value. As the time for detecting a positive culture has decrease with the use of liquid media and probes for identification, we would recommend to submit only two specimens for the routine diagnosis and see the patient again 1 moth later. If in this time, the laboratory has'nt obtain any positive result and the clinician still suspect a tuberculosis, a second set of specimens can be submitted. With this measures, laboratory that received a great number of specimens, could assume the work of small laboratory without increasing there work and budget, and the diagnosis of tuberculosis will be optimized.

Clinical Laboratory Techniques↗
PubMed1999

Evidence for polymorphism in glisentide.

The polymorphism of glisentide has been investigated. Three polymorphs (I, II, III) have been prepared by recrystallization from different solvents and other polymorphic form (IV) was obtained by heating polymorph III at 100 degrees C. In addition, two 1:1 stoichiometric solvates containing carbon tetrachloride and dioxane have been crystallized and finally, an amorphous solid has been obtained. It has been observed that the polarity of the recrystallisation solvent and its ability to form hydrogen bonds have a great influence on the polymorphism of glisentide. The different solid forms of glisentide have been characterized using X-ray diffraction analysis, differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), IR spectroscopy and optical microscopy. The recrystallization of polymorph I in melted form II and also the transition of form III-IV have been detected by DSC and X-ray diffraction analysis.

Benzamides↗