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Biomedical subjects

M C Santos

Publications and source records attributed to M C Santos.

At least 37 records · Page 2Linked to original sources
PubMed1999

Primary Swenson pull-through compared with multiple-stage pull-through in the neonate.

BACKGROUND: In Hirschsprung's disease, the trend has been for earlier performance of definitive surgery. In our institution, primary Swenson pull-through has become the preferred procedure. METHODS: Retrospective review of the patients treated for Hirschsprung's disease from January 1988 through March 1998 was performed. Sixty-five patients were identified. Median values, analysis of variance and x2 were used for comparisons. RESULTS: The multiple-stage group (M, n = 47) was similar to the primary group (P, n = 18) for gestational age (40 v 39 weeks), time to meconium passage (37.9 v 35.5 hours), and age at diagnosis (median, M 27 vP 3.5 days). Age (median, M 268 vP 5 days) and weight (mean, M 9.4 v P 3.7 kg; P < .001) at pull-through were lower in the primary group. Length of stay (LOS) was lower in the primary group (mean, M 40.8 vP 20.3 days; P < .05). Operating time for pull-through was decreased in P (mean, M 305.2 v P 272.2 minutes; P = .02). Total complications were lower in the primary group (P = .03), with no differences in mortality or enterocolitis rates. CONCLUSIONS: At our institution there were no increases in total complications or enterocolitis in the group undergoing primary Swenson. Primary pull-through is a viable option for the treatment of Hirschsprung's disease.

Analysis of Variance↗
PubMed1999

Extraocular extension of unrecognized choroidal melanoma simulating a primary optic nerve tumor: report of two cases.

BACKGROUND: Orbital extraocular extension of choroidal melanoma is well known and is usually detected in eyes with medium and large tumors, but it is very rare with small melanomas. It is particularly unusual for choroidal melanomas of any size to invade the optic nerve or its meninges. DESIGN: Two case reports. PARTICIPANTS: Two patients with small, relatively inconspicuous juxtapapillary pigmented choroidal lesions were referred with the diagnosis of primary optic nerve tumor. Both demonstrated a large nodular tumor in the meninges of the optic nerve, immediately posterior to the globe. METHODS: Retrospective review of clinical records and histopathology. RESULTS: In both cases, orbital magnetic resonance imaging confirmed the presence of a hyperintense enhancing nodular mass near the anterior portion of the optic nerve, prompting optic nerve biopsy in one case. Subsequent fundus examination disclosed a small juxtapapillary pigmented choroidal lesion measuring 1.0 mm or less in thickness. These observations suggested that the optic nerve tumor might be nodular extraocular extension of a small choroidal melanoma. Modified enucleation was performed in both cases, and histopathologic examination revealed a nodule of malignant melanoma within the meninges that compressed the optic nerve and extended extraocularly from a small, relatively inapparent juxtapapillary choroidal melanoma. In both cases, the extraocular component was large and symptomatic, whereas the intraocular component was inconspicuous. CONCLUSIONS: Small juxtapapillary choroidal melanomas can exhibit prominent extension into the orbit. All patients with orbital tumors should have careful ophthalmoscopy.

Aged↗
PubMed1999

Development of immunoglobulins to venoms during specific immunotherapy.

Immunotherapy against venoms (itv) is an efficacious treatment for most subjects who are allergic to hymnenoptera venoms. The authors studied 8 patients: 7 who were allergic to honey been venom and 1 who was allergic to wasp venom, followed for two years during immunotherapy with an aqueous extract of pure venoms from ALBAY Dome Hollister Stier. Specific IgE and IgG4 were evaluated by the Elisa Cap Technique of Pharmacia at different times: T0 before immunotherapy, T1 (one year after) and T2 (2 years after). A significant fall of specific IgE (p < 0.02) and a significant increase in specific IgG4 (p < 0.008) were seen during the two years in all patients. Four of the patients were re-stung and none had systemic reactions. These results suggest that increase in specific IgG4 is correlated with the protective effect of immunotherapy.

Adult↗
PubMed1999

Interleukin-1 mediates hemodynamic dysfunction and release of eicosanoids and tumor necrosis factor during graded bacteremia.

The pathophysiologic events of sepsis mediated by interleukin-1 (IL-1) remain ill-defined. The purpose of this study was to identify the circulatory derangements of which IL-1 was a necessary mediator and evaluate its interactions with tumor necrosis factor (TNF) and the eicosanoids during graded bacteremia. Eleven adult female swine were anesthetized, mechanically ventilated, and monitored with pulmonary artery catheters and arterial lines; they received intravenously either saline vehicle (septic control, n = 6) or human recombinant IL-1 receptor antagonist (IL-1ra, n = 5). The animals were then infused with Aeromonas hydrophila (10(9)/mL) for 4 h at rates gradually increased from .2 mL/kg/h to 4 mL/kg/h over 3 h, then sacrificed after 4 h. Mean arterial pressure (MAP), left ventricular stroke work index (LVSWI), and systemic vascular resistance index (SVRI) were recorded at baseline and hourly thereafter, and plasma 6-keto-PGF1alpha (6-KETO), tumor necrosis factor-alpha (TNF) and leukotrienes B4(LTB4) and C4D4E4 (LTCDE), pg/mL, were measured by ELISA. MAP, LVSWI, arterial P(O2) all decreased in the septic control group to levels significantly below those of the IL-1 antagonist animals. Circulating 6-KETO, LTCDE, and TNF increased significantly in all septic animals. Plasma LTB, and TNF were reduced by IL-1 blockade, compared with septic controls. TxB2 was not affected by IL-1 inhibition. There were no intergroup differences in platelet aggregation, but the in vitro aggregation response decreased from baseline in septic controls to 54+/-27% (p < .05). IL-1 is necessary to the development of systemic hypotension impaired LVSWI, and increased intravascular platelet aggregation during graded bacteremia. Conversely, IL-1 helps to maintain stroke volume and low SVRI in graded bacteremia, possibly through increased prostacyclin release. It may contribute to impaired pulmonary gas exchange and increased tissue oxygen demands. TNF release is stimulated in the presence of unopposed IL-1 and may be synergistic with it in the adverse hemodynamic effects of endogenous IL-1. IL-1 is required for increased leukotriene and prostacyclin levels in this model, but it is not involved in thromboxane release. Whether the lack of survival benefit from IL-1ra in human sepsis is due to these mixed cardiopulmonary and mediator effects, to species differences, or to timing of IL-1ra administration is not clear from the data.

Animals↗
PubMed1998

Pharmacologic inhibition of collagen in an experimental model of subglottic stenosis.

Subglottic stenosis occurs as a complication of prolonged endotracheal intubation secondary to inflammation with development of scar tissue and subsequent fibrosis. Collagen I and III levels increase during the healing process. Steroids alter the inflammatory response, decreasing recruitment of macrophages and fibroblasts. Beta-aminopropionitrile (betaAPN) inhibits the development of collagen cross-linking. A mechanism that would minimize hypertrophic scarring was sought. Eighteen dogs were anesthetized, had tracheostomies performed, and later had cautery of the mucosa and inner layer of the cricoid cartilage. Of 18 survivors, 6 animals were used as controls, 6 animals received oral Decadron, 2 mg/d, and 6 animals received oral betaAPN, 40 mg/d. There were 9 early deaths--5 in the steroid group. Animals were painlessly sacrificed, and the specimens were sectioned at the cricoid cartilage level and were stained immunohistochemically for antibodies to collagen types I to VI. Analysis of the area of scar and the intensity of stain was performed with Mocha image analysis software. Collagen III increased in control animals to 14.38 +/- 1.85 (intensity stain index), but this reaction was reduced by betaAPN (5.77 +/- 1.78, p < .01). Steroids had no significant effect on formation of any type of collagen. Lathyrogens (betaAPN) may offer a pharmacologic tool to reduce scar tissue.

Aminopropionitrile↗
PubMed1998

Factors affecting wound complications in repair of ventral hernias.

Wound-related complications are common after incisional hernia repair. Prophylactic antibiotic use, placement of subcutaneous drains, and technical factors such as mesh implantation reportedly influence the incidence of these complications. Our aim was to study the incidence of wound complications in incisional hernia repairs and to determine whether use of antibiotics, drains, or mesh influence these rates. Two hundred fifty hernias were repaired in 206 patients over a 14-year period. Simple repair was performed in 151 patients while mesh was used in 99 repairs. Mesh repair was used in larger hernias, required longer operating time, and had greater blood loss than simple repair. Twenty-eight per cent of repairs with mesh were for recurrent hernias compared with 14 per cent for simple repair (P < .05). Overall, 34 per cent of patients had wound-related complications. Chronic obstructive pulmonary disease, obesity, steroid therapy, and previous wound infection were not associated with increased risk for wound complications. The use of mesh and hernia defect > 10 cm were associated with significantly more wound complications. The incidence of seroma was increased in mesh repairs (21% vs 7%), as were total wound complications (44% vs 26%; P < 0.05). A suprafascial onlay mesh technique resulted in more frequent seroma formation. Patients undergoing mesh repair were more likely to receive antibiotics (91% vs 71%) and have subcutaneous drains placed (57% vs 25%; P < 0.05) compared to simple primary repair. Neither antibiotics nor drains had an effect on the incidence of wound complications within each group. Overall, wound infections were more frequent when drains were placed. We conclude that repair of incisional hernias is associated with substantial risk of wound-related complications. Mesh is used for repair of larger and more complex hernias and is associated with increased risk of wound complications. Abnormal fluid collections are the most frequent problem, but the use of drains does not reduce the incidence of these complications.

Adult↗
PubMed1998

Kinetics of eosinophil cationic protein release in mite-allergic rhinitis after specific nasal provocation.

Nasal allergen challenges, despite not reproducing exactly natural allergen exposures, are a useful method to try to understand the complex mediator and cellular kinetics as well as the cellular interactions triggered by allergen exposure in allergic rhinitis. In this article we evaluated the kinetics of Eosinophil Cationic Protein (ECP) release into nasal lavage fluid after nasal allergen challenge. Our results have shown heterogeneity in ECP kinetics, probably due to heterogeneous activation of the eosinophils already present in the nasal mucosa of perennial allergic rhinitis patients. More studies in this field are needed to evaluate the effect of specific immunotherapy and/or prolonged topical steroid therapy on the kinetics of ECP liberation after allergen challenge. These studies will ultimately lead to a more clear definition of the clinical usefulness of this procedure.

Adolescent↗
PubMed1998

Nasal allergen challenge and immunotherapy control.

Nasal allergen challenges, despite not reproducing exactly natural allergen exposure, are a very useful method to understand the complex cellular kinetics and cellular interactions that occur in allergic rhinitis. Cell-specific soluble mediator measurements can give useful diagnosis information as well as complementary information regarding the monitoring of specific immunotherapy. In this article we present data concerning eosinophil cationic protein and tryptase measurements after nasal allergen and the influence of specific immunotherapy on nasal peak flow before and 1, 2 and 3 years after starting immunotherapy.

Allergens↗
PubMed1997

Nasal allergen challenge and mediators release.

Nasal allergen challenges, despite not reproducing exactly natural allergen exposure, are a very useful method to understand the complex cellular kinetics and cellular interactions that occur in allergic rhinitis. Cell-specific soluble mediator measurements can give useful diagnostic information. In this paper we present data concerning eosinophil cationic protein (ECP) and tryptase measurements after nasal allergen challenge.

Allergens↗
PubMed1995

Airway measurement using morphometric analysis.

Measurement of airway size using endoscopic morphometry was investigated. Endoscopic images of the porcine tracheobronchial tree were obtained via a Storz system at a known distance from the telescope. The bronchi were marked with transluminal wires, transected, and imaged. All images were analyzed morphometrically with a computer image at multiple sites (N = 20). The endoscopic measurements were plotted against the macro lens images so that a straight line with a slope of 1 would indicate a consistent correlation. Area measurements for all images had a slope of 0.67 (r = .885); however, for images with area < 80 mm2 the slope was 1 (r = .879), for images with area < 80 mm2 of 0.93 (r = .875), and for images with area > 80 mm2 of -0.34 (r = .482), and major axis had a slope for all images of 0.73 (r = .904), for images with area < 80 mm2 of 0.88 (r = .923), and for images with area > 80 mm2 of -0.59 (r = .771). Accurate area measurements as well as major and minor axis measurements can be obtained for airways with area < 80 mm2 by means of this system. Each bronchoscope-telescope unit has an optimal target size for which measurements are accurate.

Bronchi↗
PubMed1995

Cytokines and adhesion molecules in respiratory allergy.

Cytokines and adhesion molecules play a central role in the inflammatory process of respiratory allergy. Cytokines like IL4 acts on IgE synthesis and expression of low affinity CD23 IgE receptors, IL-5 on eosinophil differentiation and activation and IL-2 on T cell activation and on the expression of CD25 IL-2 receptors. IL-2, IL-4 and IL-2 soluble receptor have been studied in pollen sensitive patients before, during and after pollen season. IL-2 serum levels initially increase and decrease at the end of allergen exposition. IL-4 serum level do not significantly changes during pollen season. Adhesion molecules are essential for recruitment and migration of inflammatory cells to tissues. CD45RO T memory cells expressing generally the adhesion molecule CD29 have also been studied in a group of pollen sensitive patients. During the peak of antigen exposition CD45RO/CD29 cells significantly decrease a turnover between CD45RA naive cells and memory cells being observed. The study of cytokines and adhesion molecules could add new data on the comprehension of inflammation in respiratory allergy.

Cell Adhesion Molecules↗
PubMed1994

Analysis of multiple primary cancers in a single institution.

Records of 120 patients with two and 16 with three primary cancers were evaluated. There were 49 males and 71 females among the double primaries with ages ranging from 27-102 years (average 68 years at the time of fist cancer). Of 35 breast cancer patients 16 new primaries developed in the opposite breast and other sites including four colon, three lung, and three endometrium. Of 20 colon cancer patients second primaries occurred in 11 sites most commonly colon (four) and lung (three). The frequency of second primaries may be skewed by the fact that patients with lethal cancers did not live long enough to develop them. This is borne out by the fact that 74 of the 120 patients were alive at the time of the study, implying a highly favorable group of patients. The interval between primaries was longer in females than males (P < 0.05) and this difference disappeared when breast and endometrial cancer were eliminated. When age was evaluated as a factor younger patients appeared to have a longer interval between primaries (P = 0.24) and this became significant for breast patients under age 55 years (91 months vs. 36 months) (P < 0.05). The stage of the second breast primary bore no relationship to the interval between primaries.

Adult↗
PubMed1994

HIV infection, risk behaviors, and depressive symptoms among Puerto Rican sex workers.

This paper examines the association of depressive symptoms with human immunodeficiency virus (HIV) infection and risk behaviors among 127 sex workers. Data were obtained by a structured interview and blood specimens tested for HIV. Findings showed a high prevalence rate of depressive symptoms for all sex workers regardless of HIV infection status. Results of a logistic regression analysis indicated that the use of injected drugs and engaging in unprotected intercourse with clients were strongly associated with a high level of depressive symptoms.

Adolescent↗
PubMed1992

Vagal function impairment after exercise training.

The present investigation was undertaken to evaluate the vagal function of trained (T) and sedentary (S) rats by use of different approaches in the same animal. After 13 wk of exercise training (treadmill for 1 h 5 times/wk at 26.8 m/min and 15% grade), T rats had a resting heart rate (HR) slightly but significantly lower than S rats (299 +/- 3 vs. 308 +/- 3 beats/min). T rats had marked reduction of the intrinsic HR (329 +/- 4 vs. 369 +/- 5 beats/min) after blockade by methylatropine and propranolol. They also exhibited depressed vagal and sympathetic tonus. Baroreflex bradycardia (phenylephrine injections) was reduced, bradycardic responses produced by electrical stimulation of the vagus were depressed, and responses to methacholine injection were decreased in T rats. Therefore several evidences of vagal function impairment were observed in T rats. The resting bradycardia after exercise training is more likely to be dependent on alterations of the pacemaker cells, inasmuch as the intrinsic HR was markedly reduced.

Animals↗