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M Campos

Publications and source records attributed to M Campos.

At least 37 records · Page 2Linked to original sources
PubMed2001

Substrate specificity characterization of recombinant metallo oligo-peptidases thimet oligopeptidase and neurolysin.

We report a systematic and detailed analysis of recombinant neurolysin (EC 3.4.24.16) specificity in parallel with thimet oligopeptidase (TOP, EC 3.4.24.15) using Bk sequence and its C- and N-terminal extensions as in human kininogen as motif for synthesis of internally quenched fluorescent substrates. The influence of the substrate size was investigated, and the longest peptide susceptible to TOP and neurolysin contains 17 amino acids. The specificities of both oligopeptidases to substrate sites P(4) to P(3)' were also characterized in great detail using seven series of peptides based on Abz-GFSPFRQ-EDDnp taken as reference substrate. Most of the peptides were hydrolyzed at the bond corresponding to P(4)-F(5) in the reference substrate and some of them were hydrolyzed at this bond or at F(2)-S(3) bond. No restricted specificity was found for P(1)' as found in thermolysin as well for P(1) substrate position, however the modifications at this position (P(1)) showed to have large influence on the catalytic constant and the best substrates for TOP contained at P(1), Phe, Ala, or Arg and for neurolysin Asn or Arg. Some amino acid residues have large influence on the K(m) constants independently of its position. On the basis of these results, we are hypothesizing that some amino acids of the substrates can bind to different sub-sites of the enzyme fitting P-F or F-S bond, which requires rapid interchange for the different forms of interaction and convenient conformations of the substrate in order to expose and fit the cleavage bonds in correct position for an efficient hydrolysis. Finally, this plasticity of interaction with the substrates can be an essential property for a class of cytosolic oligopeptidases that are candidates to participate in the selection of the peptides to be presented by the MHC class I.

Amino Acid Sequence↗
PubMed2001

Histochemical and immunohistochemical study of the intrinsic innervation in colonic dysganglionosis.

Defective innervation of the neuromuscular junctions (NMJ) was recently described in intestinal neuronal dysplasia type B (IND B). The aim of the present study was to correlate the alterations in NMJs to other classically described parameters in dysganglionoses and to determine the relationship between NMJ abnormalities in IND B and clinical symptoms. The rectal biopsies and full-thickness colonic biopsy specimens of 17 patients were studied applying histochemical (acetylcholinesterase [AChE], lactic dehydrogenase [LDH], and succinic dehydrogenase [SDH] reactions) and immunohistochemical (neuronal-cell adhesion molecule [NCAM] and SY antibodies) methods. Thirteen patients had Hirschsprung's disease (HD). IND B was diagnosed in 11 (associated with HD in 8 cases, isolated in 2, and associated with hypoganglionosis in 1). In the aganglionic segment of HD there was very intense AChE activity; in contrast, NCAM- and SY-immunoreactive nerve fibers were markedly decreased. A spectrum of abnormalities was observed in IND B, usually more severe in the most distal segments: giant and immature ganglia in the submucous plexus were observed in all cases; heterotopic myenteric ganglia were frequent (72.7%); hyperganglionosis was observed in 6 (54.5%) and was not related to the patients' age; thick and tortuous NCAM- and SY-immunoreactive nerve fibers, irregularly distributed in the colonic wall, were observed in 81.8% of the cases. No relationship was observed between abnormalities of NCAM- and SY-immunoreactive nerve fibers and AChE activity, ganglion-cell maturity, heterotopy, or the clinical symptoms presented by the patients with IND B. In hypoganglionism, low AChE activity and a slight decrease in NCAM- and SY-immunoreactive nerves were observed. Thick and tortuous, irregularly-distributed intrinsic NCAM- and SY-immunoreactive nerves were observed in every colon layer in IND B. Our results do not support IND B as a NMJ disorder.

Child↗
PubMed2001

Laparoscopic colonic mapping of dysganglionosis.

Retention of a proximal aganglionic segment or the unrecognized coexistence of other dysganglionoses may jeopardize the definitive surgical treatment of Hirschsprung's disease (HD). To assess the extent of the disease and/or the presence of other dysganglionoses without an additional laparotomy, we developed a laparoscopic-assisted technique to perform colonic full-thickness biopsies. After creation of a pneumoperitoneum, a 5-mm laparoscope is inserted in the supraumbilical area and a working 10/12-mm port is placed in the left iliac fossa. The sigmoid/descending colon is grasped and pulled through the abdominal wall and a full-thickness biopsy done. The same procedure is applied to the transverse and ascending colon. Rectal and colonic biopsy specimens were studied using enzyme histochemical methods. Over the last year, five children aged 7 months to 12 years with dysganglionosis underwent laparoscopic-assisted mapping of the colon. Previous rectal suction biopsies were diagnostic of HD in three patients and suspicious of hypoganglionosis in two. Proximal full-thickness biopsies revealed: normal colon in two cases of HD; coexistent type B intestinal neuronal dysplasia up to the descending colon in the other case of HD; and hypoganglionosis up to the ascending colon in the two patients with suspected hypoganglionosis. The procedures were performed easily, the patients being discharged after 36 to 48 h with no complications. Four children have already undergone pull-through procedures with resection of the affected colon in adhesion-free abdominal cavities and did not develop constipation or enterocolitis. Laparoscopic-assisted mapping of the entire colon is a simple, safe, and effective procedure that may contribute to improving the outcome of intestinal dysganglionosis by better characterization of the disease.

Child↗
PubMed2001

Delayed gastric emptying and gastroesophageal reflux: a pathophysiologic relationship.

BACKGROUND: Delayed gastric emptying (DGE) is frequent in patients with gastroesophageal reflux (GER), but its pathophysiologic role has not yet been established. To identify a relationship between DGE and GER, we assessed whether DGE increases esophageal acid exposure and the related importance of possible mechanisms. METHODS: Thirty pediatric patients with pathological GER were divided according to gastric emptying scintigraphy into a DGE group (n = 14) and normal-emptying group (n = 16). The esophageal pH-monitoring parameters of the two groups were compared with respect to the individual variation between postprandial and fasting periods. RESULTS: Patients with DGE had less total acid exposure than did those with normal emptying, but patients in both groups had a pathological fraction of time when pH was below 4 in both the postprandial (median: 18 vs. 27.6; P = 0.49) and fasting (8.5 vs. 23.9; P = 0.01) periods. Patients in the normal-emptying group had similar fraction of time when pH was below 4 in the postprandial and fasting periods. However, patients in the group with DGE had a fraction of time when pH was below 4 in the postprandial period that was almost double that presented in fasting period (postprandial to fasting ratio: 2.11:0.90; P = 0.002). The postprandial to fasting ratio for episodes per hour was similar in the two groups (1.81 vs. 1.79; P = 0.62). Patients with DGE had a significantly higher frequency of long episodes in the postprandial period than did those with normal emptying (62.5% vs. 38.2%; P = 0.04). The occurrence of the longest episode in the postprandial period was also significantly higher for patients with DGE (57.1% vs. 6.2%; P = 0.003). CONCLUSIONS: DGE seems to accentuate postprandial reflux by increasing the volume of refluxate per episode of reflux through an underlying incompetent lower esophageal sphincter.

Case-Control Studies↗
PubMed2000

Myopic angle-supported intraocular lenses: two-year follow-up.

OBJECTIVE: To evaluate clinical and refractive results of myopic angle-supported intraocular lenses (IOLs). DESIGN: Prospective, noncomparative case series. PARTICIPANTS: Twenty-one eyes of 12 patients (7 female) with a mean age of 29.5 years and a follow-up of 24 months. The prospective study included highly myopic eyes (more than -11.00 diopters [D]) with spectacle-corrected visual acuity better than 20/200. METHODS: Twenty-one eyes underwent implantation of a single-piece IOL with Z-shaped haptics for angle support (each haptic with two footplates) and an optical zone of 4.5 mm (NuVita, Bausch & Lomb Surgical, Irvine, CA). The dioptric power of the IOL was calculated considering refraction, keratometry, and anterior chamber depth (specific nomogram), and its diameter was determined by adding 0.5 mm to the corneal diameter. MAIN OUTCOME MEASURES: We evaluated the following clinical and refractive data: visual acuity without and with correction (VAsc and VAcc), spherical equivalent (SE) obtained under cycloplegia, slit-lamp biomicroscopy, keratometry, applanation tonometry, endothelial cell count, ultrasound pachymetry, gonioscopy, indirect ophthalmoscopy, subjective complaints, and descriptions of complications. RESULTS: Mean postoperative VAsc was 20/74. Mean preoperative VAcc (20/50) increased to 20/30; 65% gained at least two lines of VAcc, and no eye had a decrease in VAcc. Preoperative SE (-18.95 D) evolved to -2. 06 D, stabilizing after one month. Iris retraction (pupil ovalization) more than 0.5 mm was noted in eight eyes (40%). Mean keratometry, corneal astigmatism, and ultrasound pachymetry were stable during the study (P > 0.01). Significant endothelial cell loss was demonstrated in the second year. Gonioscopy showed 70 (87. 5%) footplates ideally positioned with no iris depression. Reports of glare and haloes in dark environment were considered light in 80% and not referred in 20%, and spectacles were used for residual refraction in 75%. Intraocular lens exchange was needed in one eye because of undersizing, and the IOL was removed in one eye because of chronic inflammatory reaction associated with ocular hypertension (this patient was excluded from the statistical analysis). CONCLUSIONS: This report demonstrates good efficacy for correction of high myopia by the phakic IOL used during the two years of follow-up. Long-term complications (safety) such as iris retraction and endothelial cell loss remain a concern.

Adult↗
PubMed2000

Acoustic analysis of the voice in phonatory fistuloplasty after total laryngectomy.

A comparative study of the voice with sustained phonation of the vowel /a/ was made in 3 groups of male patients: (1) 20 patients receiving total laryngectomy for epidermoid carcinoma of the larynx who had acquired good voice quality after a phonatory fistuloplasty with a Herrmann voice prosthesis; (2) 20 patients undergoing total laryngectomy for epidermoid carcinoma of the larynx who had learned esophageal speech; and (3) 20 subjects with normal voices. Statistical analysis yielded significant differences in fundamental voice frequency between the 3 groups, with the patients with phonatory prostheses revealing the closest to a normal voice. For other parameters used, such as jitter, shimmer, and harmonics/noise ratio, voice quality with a phonatory prosthesis was similar to that obtained with esophageal speech.

Adult↗
PubMed2000

First report of presumed parasitic keratitis in Indians from the Brazilian Amazon.

PURPOSE: To describe corneal disorders in patients with systemic parasitic disease. METHODS: Cross-sectional study consisted of ophthalmologic examinations, peripheral blood tests and skin biopsies in 496 subjects (395 Indians and 101 non-indians) from the upper Negro River, Brazilian Amazon. RESULTS: Mansonella ozzardi was detected in the blood of 140 (28.23%) subjects. Seventy-six (55.07%) of them also presented multiple nummular opaque superficial lesions in the cornea. None of the examined patients presented onchocercal-related skin lesions or positive skin biopsies for filaria. CONCLUSION: There was a significant association between mansonelliasis and keratitis.

Adolescent↗
PubMed1999

Cytokine profiles following interaction between bovine alveolar macrophages and Pasteurella haemolytica.

Pasteurella haemolytica is a gram negative bacterium frequently isolated from the lungs of calves suffering from a fibrinous pneumonic condition known as shipping fever. To understand the pathogenesis of this disease, we investigated the induction of cytokin gene expression in cultures of bovine alveolar macrophages (BAM) stimulated with heat-killed P. haemolytica. Northern blot analysis of total RNA showed that P. haemolytica induced early, abundant, and consistent synthesis of IL-1, TNF-alpha, and IL-8 mRNA. Cytokine mRNAs were detected within 1 hr post-stimulation with heat-killed P. haemolytica. IL-1 and IL-8 mRNA accumulated to high levels with increase in stimulation time, whereas TNF-alpha mRNA clearly declined by 4 and 8 h post stimulation. IL-1, TNF-alpha, and IL-8 proteins were also secreted into the culture medium of BAM stimulated with heat-killed P. haemolytica. All three proteins were detected at high levels 8 and 12 h post stimulation with P. haemolytica. BAM cells treated with bovine interferon-alpha and then stimulated with P. haemolytica produced higher amounts of IL-1, IL-8 and TNF-alpha proteins compared to BAM stimulated with P. haemolytica alone. These findings demonstrate the powerful and selective induction of cytokine mRNA and protein synthesis in BAM stimulated with heat-killed P. haemolytica and may explain certain aspects of shipping fever pathogenesis.

Animals↗
PubMed1999

Effects of indoramin in rat vas deferens and aorta: concomitant alpha1-adrenoceptor and neuronal uptake blockade.

1. The actions of the alpha1-adrenoceptor antagonist indoramin have been examined against the contractions induced by noradrenaline in the rat vas deferens and aorta taking into account a putative neuronal uptake blocking activity of this antagonist which could result in self-cancelling actions. 2. Indoramin behaved as a simple competitive antagonist of the contractions induced by noradrenaline in the vas deferens and aorta yielding pA2 values of 7.38+/-0.05 (slope=0.98+/-0.03) and 6.78+/-0.14 (slope=1.08+/-0.06), respectively. 3. When the experiments were repeated in the presence of cocaine (6 microM) the potency (pA2) of indoramin in antagonizing the contractions of the vas deferens to noradrenaline was increased to 8.72+/-0.07 (slope=1.10+/-0.05) while its potency remained unchanged in the aorta (pA2=6.69+/-0.12; slope=1.04+/-0.05). 4. In denervated vas deferens, indoramin antagonized the contractions to noradrenaline with a potency similar to that found in the presence of cocaine (8.79+/-0.07; slope=1.09+/-0.06). 5. It is suggested that indoramin blocks alpha1-adrenoceptors and neuronal uptake in rat vas deferens resulting in Schild plots with slopes not different from unity even in the absence of selective inhibition of neuronal uptake. As a major consequence of this double mechanism of action, the pA2 values for this antagonist are underestimated when calculated in situations where the neuronal uptake is active, yielding spurious pKB values.

Adrenergic alpha-1 Receptor Antagonists↗
PubMed1999

Blue rubber bleb naevus: case report and literature review.

Blue rubber bleb naevus syndrome is a rare cutaneous-digestive angiomatosis, described first by William Bean in 1958. Today, there are more than 200 cases published. The dangers of this syndrome include angiomata in the brain, kidneys or lungs (due to vasculature obliteration by in situ thrombosis). Patients are scanned with technetium-labelled red blood cells in order to identify the affected organs. Multiple techniques are used to treat the lesions by gastrointestinal endoscopy.

Aged↗
PubMed1999

Are apolipoproteins A and B better than lipoproteins for assessing risk of obstructive coronary heart disease?

OBJECTIVE: To evaluate whether apolipoproteins A-I (Apo A-I) and B (Apo B) have, higher ensitivity (SN), specificity (SP) and positive predictive value (PPV) than lipoproteins (LP), total cholesterol (TC), high density lipoprotein (HDL), low density lipoprotein (LDL), very low density lipoprotein (VLDL), and triglycerides (TGL) in assessing the risk of coronary heart disease (CHD). METHODS: This is a transversal case-control study of 241 patients, who were divided into two groups: 1) 145 patients with CHD, and 2) 96 patients without coronary disease. A model of logistic regression to evaluate the relation between the LPs and CHD was developed in which variables with a p-alpha < 0.1 were included. RESULTS: Apo A-I levels were higher in the patients without CHD, (OR 2.08, CI 1.20-3.57). There were no statistical differences between the values of Apo A-I and the remaining lipid fractions (Apo A-I: 67%; Apo B: 100%; PPV: TC = 71%; TGC = 71%; HDL = 71%; LDL = 71%). The costs of the tests in Reais were as follows: Apo A-I: R$ 56.60; Apo B-100: R$ 56.60; TC: R$ 9.94; HDL: R$ 21.30; LDL: R$ 28.40; TGL: R$ 14.20. CONCLUSION: Levels of Apo A-I and Apo B have no advantage over conventional lipoproteins in predicting the risk of CHD, despite the statistical association between Apo A-I and CHD; in addition, their costs are higher than those of the conventional lipoproteins.

Aged↗
PubMed1999

[Acoustic voice analysis in phonatory fistuloplasty after total laryngectomy].

A comparative study was made of the voices of three groups of male patients by acoustic analysis of sustained phonation of the vowel /a/: 1) 20 patients who had undergone total laryngectomy and phonatory fistuloplasty, fitted with a Herrmann voice prosthesis, who had achieved successful prosthetic speech; 2) 20 laryngectomized patients with good quality esophageal speech, and 3) 20 subjects with normal voices. Statistical analysis of fundamental frequency disclosed significant differences between groups, the group with phonatory prostheses having the closest to normal voice of the fistuloplastic groups. There were no statistically significant differences in jitter, shimmer, and the harmonic-to-noise ratio between the esophageal and prosthetic voice groups, which suggests that the disturbances in the vibratory esophageal ring were similar.

Adult↗
PubMed1999

Pathogenesis of porcine Actinobacillus pleuropneumonia, part II: roles of proinflammatory cytokines.

The in vitro production of proinflammatory cytokines after stimulation with Actinobacillus pleuropneumoniae and the relation of these cytokines in vivo with the disease caused by A. pleuropneumoniae were investigated. Within 24 h, in vitro stimulation by A. pleuropneumoniae (serotype 1) preparations, including killed bacteria, bacterial culture supernatant, lipopolysaccharide, and bacterial extracts, porcine pulmonary alveolar macrophages (PAM) produced significant (P < 0.05) amounts of tumor necrosis factor-alpha (TNF-alpha) and interleukin-1 (IL-1) as measured by bioassays. The supernatants containing interleukin-8 from PAM after stimulation by bacterial preparations showed significant neutrophil chemotaxis, while bacterial preparations alone did not. After in vivo infection with A. pleuropneumoniae, the mean levels of TNF-alpha and IL-1 in serum, as measured by bioassays, were elevated 37- to 27836-fold for TNF-alpha and 11- to 5941-fold higher for IL-1 within 4 d post-infection, depending on the treatments, and remained elevated up to Day 7. Both cytokines were also detected in porcine lungs by bioassays and immunocytochemistry. The results indicated that both secreted and surface components of A. pleuropneumoniae can stimulate PAM to produce proinflammatory mediators. Neutrophil chemoattractants rather than bacterial components are the major factor causing acute lung inflammation. The elevation of TNF-alpha and IL-1 in pigs occurred coincident with the onset of acute clinical disease.

Actinobacillus Infections↗
PubMed1998

Effect of partial HLA class I match on acute rejection in viral pre-infected human liver allograft recipients.

BACKGROUND: Acute rejection in liver transplants is one of the commonest causes of liver dysfunction in the early postoperative period. However, the factors involved in liver graft rejection are still unknown. Our study was aimed at ascertaining whether the degree of HLA class I and class II compatibility or pretransplant viral infection have any influence on early acute liver graft rejection. METHODS: We reviewed clinical and laboratory data in 190 consecutive patients who underwent a liver transplant. HLA-A, HLA-B, and HLA-DR typing for the establishment of an HLA match score was performed by a standard microcytotoxicity method. The existence of pretransplant viral infection was investigated in sera and biopsy tissue by serologic (hepatitis B virus, hepatitis C virus) and polymerase chain reaction (cytomegalovirus) techniques, respectively. The influence of these two factors in acute rejection and the interaction between them was also analyzed. RESULTS: A strong association between viral infection and acute rejection in the group with partial class I matching was found (odds ratio=7.75; P<0.0009), whereas no correlation was observed in the group with zero class I matching (odds ratio=0.98; P=0.81). The rejection percentage in the group in which partial class I match and viral infections coexisted was 60%, whereas in the partially class I-matched group without pretransplant viral presence it was 16%. CONCLUSIONS: These findings suggest a participation of partial HLA class I compatibility in triggering acute rejection in recipients suffering preoperative viral infections and support the idea that HLA class I antigen matching could play a role as a linking element between the MHC-restricted T cell-mediated response to viral infection and the allogenic response in liver transplantation.

Adolescent↗
PubMed1998

Gastric inflammatory myofibroblastic proliferation in children.

Gastric inflammatory myofibroblastic proliferation (IMP) is an extremely rare entity in children, which to our knowledge has only been mentioned in case reports. We describe the ninth pediatric case and review the literature concerning the etiology, clinical and laboratory features, pathology, treatment, and outcome. There has been a predominance in preschool females. Abdominal pain, upper gastrointestinal hemorrhage, and an abdominal mass, either isolated or associated, have been the main clinical features. Iron-deficiency anemia has been a constant finding. Lesions are elevated and involve the full thickness of the gastric wall, usually with ulceration of the luminal surface; extragastric extension suggesting malignancy is frequent. Diagnosis is made by histology after surgical excision. There was no mortality directly related to gastric IMP, and only one case recurred after surgical excision. The pathogenesis is controversial, but the finding of Helicobacter pylori in our case may indicate an inflammatory origin. Awareness of this benign lesion and its mimicry of malignancy is important so that inappropriately aggressive therapy can be avoided.

Cell Division↗
PubMed1998

Alterations in blood-aqueous barrier after corneal refractive surgery.

PURPOSE: To assess alterations in the blood-aqueous barrier after radial keratotomy (RK), photorefractive keratectomy (PRK), laser in situ keratomileusis (LASIK), and phototherapeutic keratectomy (PTK). METHODS: Aqueous flare was evaluated using the Kowa FM 500 laser flare meter in a total of 87 eyes from 82 patients who underwent refractive surgery. Measurements were obtained preoperatively in 51 eyes of 51 patients who underwent RK or PRK and again at the end of surgery, and at 1 day and 1 week postoperatively. These patients had been randomized (double masked) to receive topical 0.1% dexamethasone, polymyxin B (6,000 U/ml), and 0.5% neomycin 4 times a day for 1 week after surgery, or polymyxin B (6,000 U/ml) and 0.5% neomycin for 1 week. Aqueous flare measurements were also obtained before surgery in 36 eyes (31 patients) that underwent LASIK and again at 1 day and 1 and 2 weeks postoperatively. All patients in this group received topical 0.1% dexamethasone, polymyxin B (6,000 U/ml), and 0.5% Neomycin 4 times a day for 15 days after surgery. RESULTS: Uneventful RK induced a significant increase in flare immediately after surgery, although this did return to baseline 1 day after surgery (Friedman test). Measurements at 7 days after surgery were similar in steroid-treated and untreated groups. Limbal bleeding, which occurred in 23% (12/51) eyes, did not induce significantly increased flare as compared to uneventful RK. Microperforations, which occurred in 18% (9/51) eyes, did induce significant alterations in the blood-aqueous barrier that persisted for >1 day, but measurements returned to preoperative levels by day 7. PRK and LASIK induced substantially increased flare in some eyes. Phototherapeutic keratectomy, in particular, induced an elevation in flare measurements that did not return to normal levels even by 15 days after surgery (Friedman test). CONCLUSIONS: Using mean results of laser flare meter evaluation, uneventful RK appears to induce short-lasting elevations in aqueous flare in both steroid-treated and untreated patients. Microperforation induced prominent alterations in flare measurements, although limbal bleeding did not. Both PRK and LASIK did appear to increase flare measurements in some eyes, while PTK induced significant elevations in aqueous flare in the majority of eyes.

Adolescent↗