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Biomedical subjects

M Campos

Publications and source records attributed to M Campos.

At least 19 recordsLinked to original sources
PubMed2006

Epidermolysis bullosa acquisita: diagnosis by fluorescence overlay antigen mapping and clinical response to high-dose intravenous immunoglobulin.

Epidermolysis bullosa acquisita (EBA) is a chronic, subepidermal blistering disease characterized by the presence of autoantibodies to type VII collagen, located below the lamina densa of the basement membrane zone (BMZ). There is a large clinical and histological overlap between EBA and other subepidermal autoimmune bullous diseases, therefore, complex immunological techniques are required to make an accurate diagnosis. Therapy of EBA is also a difficult issue. Most patients do not respond to several common immunosuppressive agents. We describe a patient who has shown a good response to high-dose intravenous immunoglobulin therapy.

Antibodies↗
PubMed2006

Burow's grafts in the facial region.

BACKGROUND: Full-thickness skin grafts are an important tissue source for reconstructive surgery. Burow's grafts are full-thickness skin grafts that use adjacent lax skin as the donor site. This technique has also been referred to as island grafts, dog-ear grafts or adjacent-tissue skin grafts. OBJECTIVE: The objective was to describe the technique of Burow's grafts for reconstruction of facial defects taking account of its benefits and limitations. METHODS: The operative technique is simple: after a circular excision of the cutaneous lesion, we enlarged the excision line (towards one or both sides of the defect) following the relaxed tension lines. We created a secondary triangular defect by excising skin that is then used for the graft (as donor site). After adequate undermining, we proceeded to direct linear closure of this secondary defect. Finally, the graft was placed and sutured in the remaining defect. RESULTS: The proximity of the donor site provides an excellent tissue match because colour, hair density, texture, sebaceous features and thickness are similar to the recipient site. A good cosmetic result is therefore ensured. CONCLUSION: Burow's grafts can be a good choice for reconstruction of extensive facial surgical defects because of aesthetic results. In addition, it is a simple technique that can be performed in one sole surgical act, with local anaesthesia and without changing the operative site.

Eyelids↗
PubMed2005

Supplementary motor area encodes reward expectancy in eye-movement tasks.

Neural activity signifying the expectation of reward has been found recently in many parts of the brain, including midbrain and cortical structures. These signals can facilitate goal-directed behavior or the learning of new skills based on reinforcements. Here we show that neurons in the supplementary motor area (SMA), an area concerned with movements of the body and limbs, also carry a reward expectancy signal in the postsaccadic period of oculomotor tasks. While the monkeys performed blocks of memory-guided and object-based saccades, the neurons discharged a burst after a approximately 200-ms delay following the target-acquiring saccade in the memory task but often fired concurrently with the target-acquiring saccade in the object task. The hypothesis that this postsaccadic bursting activity reflects the expectation of a reward was tested with a series of manipulations to the memory-guided saccade task. It was found that although the timing of the bursting activity corresponds to a visual feedback stimulus, the visual feedback is not required for the neurons to discharge a burst. Second, blocks of no-reward trials reveal an extinction of the bursting activity as the monkeys come to understand that they would not be rewarded for properly generated saccades. Finally, the delivery of unexpected rewards confirmed that in many of the neurons, the activity is not related to a motor plan to acquire the reward (e.g., licking). Thus we conclude that reward expectancy is represented by the activity of SMA neurons, even in the context of an oculomotor task. These results suggest that the reward expectancy signal is broadcast over a large extent of motor cortex, and may facilitate the learning of new, coordinated behavior between different body parts.

Action Potentials↗
PubMed2005

Influence of angiotensin-converting enzyme polymorphism gene, IGF-1, and other factors in the response rate of hematocrit to enalapril treatment in patients with posttransplant erythrocytosis.

A significant relationship between hematocrit values and serum parameters such as the insulin like growth factor (IGF-1) and calcium was observed in patients with posttransplant erythrocytosis (PTE). Since angiotensin-converting enzyme inhibitors (ACEI) decrease hematocrit (Ht) levels in these patients, ACE genotype should play an important role. We designed this study to investigate whether ACE genotype or baseline concentrations of IGF-1, IGF-blood binding protein 3 (BP3), growth hormone (GH), or Ca influenced the response of Ht to ACEI treatment. Twenty-one kidney graft recipients with PTE were treated with enalapril (2.5 to 5 mg/d) for 1 year. IGF-1, BP3, GH, Ca, and Ht were determined before as well as 15, 30, 90, 180, and 365 days after enalapril treatment. ACE polymorphism was also determined. Enalapril treatment significantly decreased Ht levels. Only IGF-1 baseline levels showed a positive correlation to the decreased Ht (P < .025). ACE genotype as determined in 18 patients, showed no correlation with the response to enalapril. Patients with ACE genotype II showed a tendency to an earlier display of PTE. We conclude that low doses of enalapril decrease Ht levels in PTE patients; that PTE begins earlier in patients with II ACE genotype; and that only IGF-1 baseline levels influence the Ht decrease after treatment. These observations suggest that ACEI decrease the Ht via an inhibitory effect on IGF-1, which has a stimulary effect on erythropoiesis.

Angiotensin-Converting Enzyme Inhibitors↗
PubMed2005

Iron deficiency--an underrecognized problem in nonanemic and erythrocytic kidney transplant recipients: risks and effects of ACEI and of iron treatment.

The state of iron deposits in long-term kidney graft recipients is not well-known. Angiotensin enzyme inhibitors (ACEIs) reduce hematocrit levels in patients with posttransplant erythrocytosis (PTE), but their action on iron deposits has not been sufficiently evaluated. We designed this study to investigate the prevalence of iron deficiency among patients without anemia, the efficacy of ACEI treatment and its influence on iron deposits, and the risks of iron treatment in patients with symptomatic iron deficiency but no anemia. One hundred thirty eight patients were included if they had a kidney transplant for more than a year, with good renal function, with no anemia, and with neither iron nor rHuEpo, ARA, or ACEI treatment. One hundred seventeen had a normal Ht (group 1) and 21 had PTE (group 2). Iron deficiency was found in 73 (62.4%) group 1 patients and in 10 (47%) group 2 patients. Two group 1 patients with symptoms of iron deficiency were treated with oral iron. Their symptoms disappeared, but one developed PTE. Enalapril treatment decreased Ht levels in PTE but not in control patients. Furthermore, this drug increased iron deposits in PTE and controls with a baseline iron deficiency. We conclude that there is a high prevalence of iron deficiency in long-term transplanted patients without anemia. Furthermore, iron treatment must be carefully administered because of the risk of PTE. Enalapril treatment decreased Ht levels in PTE but not in control patients and increased iron deposits in patients with baseline iron deficiency.

Angiotensin-Converting Enzyme Inhibitors↗
PubMed2004

Effects of ornithine on neutrophil (PMN) free amino acid and alpha-keto acid profiles and immune functions in vitro.

The objective of this study was to determine the effects of ornithine on polymorphonuclear leucocyte (PMN) free amino- and alpha-keto acid profiles, superoxide anion (O2-) generation, hydrogen peroxide (H2O2) formation and released myeloperoxidase activity (MPO). Exogenous ornithine significantly increased PMN asparagine, glutamine, aspartate, glutamate, arginine, citrulline, alanine, alpha-ketoglutarate and pyruvate as intracellular ornithine increased. Concerning PMN immune function markers ornithine increased H2O2-generation and MPO activity while O2- -formation was decreased. We believe therefore that ornithine is important for affecting PMN "susceptible free amino- and alpha-keto acid pool" although the mechanisms are not yet clear. This may be one of the determinants in PMN nutrition considerably influencing and modulating PMN host defense capability.

Adult↗
PubMed2004

Detection of circulating antigens in experimental anisakiasis by two-site enzyme-linked immunosorbent assay.

A two-site enzyme-linked immunosorbent assay (ELISA) based on the avidin-biotin system was developed to study circulating antigens in the sera of rats orally or intraperitoneally infected with L3 larvae of Anisakis simplex s.l. Somatic and excretory-secretory antigens were detected from 24 h post-infection in all infected rats. A direct relationship between the number of larvae inoculated and the concentration of antigens in the sera was demonstrated; however, the amount of antigen decreased with the course of the infection. Comparative analysis revealed that intraperitoneal inoculation is most appropriate for detecting excretory-secretory antigens in serum. The minimum concentrations of A. simplex antigen detectable were approximately 2.5 microg/ml for somatic and excretory-secretory antigens. This antigen detection assay may have application in the diagnosis of anisakiasis.

Animals↗
PubMed2003

Effect of cyproterone acetate on alpha1-adrenoceptor subtypes in rat vas deferens.

Gonadal hormones regulate the expression of alpha1-adrenoceptor subtypes in several tissues. The present study was carried out to determine whether or not cyproterone acetate, an anti-androgenic agent, regulates the alpha1-adrenoceptor subtypes that mediate contractions of the rat vas deferens in response to noradrenaline. The actions of subtype selective alpha1-antagonists were investigated in vas deferens from control and cyproterone acetate-treated rats (10 mg/day, sc, for 7 days). Prazosin (pA2 approximately 9.5), phentolamine (pA2 approximately 8.3) and yohimbine (pA2 approximately 6.7) presented competitive antagonism consistent with activation of alpha1-adrenoceptors in vas deferens from both control and treated rats. The pA2 values estimated for WB 4101 ( approximately 9.5), benoxathian ( approximately 9.7), 5-methylurapidil (approximately 8.5), indoramin ( approximately 8.7) and BMY 7378 ( approximately 6.8) indicate that alpha1A-adrenoceptors are involved in the contractions of the vas deferens from control and cyproterone acetate-treated rats. Treatment of the vas deferens from control rats with the alpha1B/alpha1D-adrenoceptor alkylating agent chloroethylclonidine had no effect on noradrenaline contractions, supporting the involvement of the alpha1A-subtype. However, this agent partially inhibited the contractions of vas deferens from cyproterone acetate-treated rats, suggesting involvement of multiple receptor subtypes. To further investigate this, the actions of WB 4101 and chloroethylclonidine were reevaluated in the vas deferens from rats treated with cyproterone acetate for 14 days. In these organs WB 4101 presented complex antagonism characterized by a Schild plot with a slope different from unity (0.65 0.05). After treatment with chloroethylclonidine, the complex antagonism presented by WB 4101 was converted into classical competitive antagonism, consistent with participation of alpha1A-adrenoceptors as well as alpha1B-adrenoceptors. These results suggest that cyproterone acetate induces plasticity in the alpha1-adrenoceptor subtypes involved in the contractions of the vas deferens.

Adrenergic alpha-1 Receptor Antagonists↗
PubMed2003

Female haemophiliac homozygous for the factor VIII intron 22 inversion mutation, with transcriptional inactivation of one of the factor VIII alleles.

Phenotypic expression of X-linked recessive disorders, including haemophilia A, is rare in females. This report describes a female with sporadic severe haemophilia A. The female patient and her family members were evaluated by coagulation assays. Visible detectable disturbance of X chromosome structure or number, as well as 2N von Willebrand disease, were excluded as possible explanations of the haemophilia A phenotype. Molecular studies, factor VIII (FVIII) intron 22 inversion mutation analysis showed that the severe haemophilia A phenotype is the result of a maternally inherited, distal, FVIII gene inversion and a paternally inherited de novo, also distal, FVIII gene inversion. Furthermore, comparative single-stranded conformation polymorphism analysis revealed the absence of detectable maternally inherited abnormal FVIII gene transcript in the patient's peripheral blood lymphocytes. X chromosome methylation analysis indicates that this could be explained by preferential inactivation of the maternally inherited X chromosome carrying the distal FVIII gene inversion.

Alleles↗
PubMed2003

A clinical follow up of PRK and LASIK in eyes with preoperative abnormal corneal topographies.

AIM: To assess the safety and predictability of photorefractive keratotomy (PRK) and laser in situ keratomileusis (LASIK) based on preoperative corneal topography. METHODS: A non-randomised comparative study was carried out on 84 eyes that presented with topographic abnormalities before undergoing PRK (n = 44) or LASIK (n = 40) procedures. 84 spherical equivalent paired normal eyes served as the control group. Either PRK or LASIK procedures were performed on 168 eyes using the Summit apex plus excimer laser. Topographic abnormalities, including apex displacement (AD), increased asphericity (AS), meridional irregularity (MI), increased inferior-superior asymmetry (IS), increased curvature (CU), and combined features (CO), were assessed preoperatively using the EyeSys analysis system. Safety and predictability of the two procedures were defined as a postoperative visual acuity of 20/40 or better and the loss of one or more lines of spectacle corrected visual acuity (SCVA). RESULTS: All patients were followed for 6 months. There was a significant loss of best corrected visual acuity in the PRK-AD (p<0.001), PRK-CO (p<0.05), and LASIK-AS (p<0.001) patients. The number of eyes within plus or minus 1.0D of the surgical plan postoperatively was similar in all groups. CONCLUSION: These data suggest that although predictability was similar, PRK and LASIK performed in corneas with topographic abnormalities might cause loss of vision.

Corneal Diseases↗
PubMed2003

Low-grade parasitaemias and cold agglutinins in patients with hyper-reactive malarious splenomegaly and acute haemolysis.

A cluster of 16 cases of hyper-reactive malarious splenomegaly (HMS) with severe, acute haemolysis, from an isolated, Venezuelan, Yanomami population, was prospectively investigated. Nine (69%) of the 13 HMS sera investigated but only one (7%) of 14 control sera (P < 0.005) contained elevated titres (of at least 1:32) of complement-fixing IgM cold agglutinins (CA). The CA detected had specificity for both the I and i blood-group antigens (with a relative predominance of anti-I) and wide thermal stability. The mean reciprocal CA titre was much higher for the HMS sera than for the control samples (59.16 v. 2.28; P < 0.001). Indirect tests for antiglobulin were positive for two of the 13 HMS cases (but none of 14 controls) investigated; all of the direct tests for antiglobulin gave negative results. The seven HMS cases checked, using an assay based on a nested PCR which amplified species-specific ribosomal sequences from Plasmodium vivax or P. falciparum, each yielded the PCR product that indicated P. vivax infection. However, only six (25%) of the 24 control samples (collected, at the same time as the HMS samples, from asymptomatic adults from the same Yanomami population) were PCR-positive (P < 0.001). In some cases at least, the acute severe episodes of haemolysis occasionally seen in HMS appear to be associated with an auto-immune, cold-agglutinin-mediated response triggered by non-patent parasitaemias.

Adult↗
PubMed2001

Selective neurotensin-derived internally quenched fluorogenic substrates for neurolysin (EC 3.4.24.16): comparison with thimet oligopeptidase (EC 3.4.24.15) and neprilysin (EC 3.4.24.11).

Internally quenched fluorescent peptides derived from neurotensin (pELYENKPRRPYIL) sequence were synthesized and assayed as substrates for neurolysin (EC 3.4.24.16), thimet oligopeptidase (EC 3.4.24.15 or TOP), and neprilysin (EC 3.4.24.11 or NEP). Abz-LYENKPRRPYILQ-EDDnp (where EDDnp is N-(2,4-dinitrophenyl)ethylenediamine and Abz is ortho-aminobenzoic acid) was derived from neurotensin by the introduction of Q-EDDnp at the C-terminal end of peptide and by the substitution of the pyroglutamic (pE) residue at N-terminus for Abz and a series of shorter peptides was obtained by deletion of amino acids residues from C-terminal, N-terminal, or both sides. Neurolysin and TOP hydrolyzed the substrates at P--Y or Y--I or R--R bonds depending on the sequence and size of the peptides, while NEP cleaved P-Y or Y-I bonds according to its S'(1) specificity. One of these substrates, Abz-NKPRRPQ-EDDnp was a specific and sensitive substrate for neurolysin (k(cat) = 7.0 s(-1), K(m) = 1.19 microM and k(cat)/K(m) = 5882 mM(-1). s(-1)), while it was completely resistant to NEP and poorly hydrolyzed by TOP and also by prolyl oligopeptidase (EC 3.4.21.26). Neurolysin concentrations as low as 1 pM were detected using this substrate under our conditions and its analogue Abz-NKPRAPQ-EDDnp was hydrolyzed by neurolysin with k(cat) = 14.03 s(-1), K(m) = 0.82 microM, and k(cat)/K(m) = 17,110 mM(-1). s(-1), being the best substrate so far described for this peptidase.

Alanine↗