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Biomedical subjects

A M Levy

Publications and source records attributed to A M Levy.

At least 19 recordsLinked to original sources
PubMed2001

Increased eosinophil infiltration and degranulation in colonic tissue from patients with collagenous colitis.

OBJECTIVE: Eosinophils infiltrate the colonic mucosa of patients with collagenous colitis (CC), although the pathogenetic implications are unknown, including whether these eosinophils are activated and degranulate in situ. We examined eosinophil infiltration and degranulation in the intestines of patients with CC by immunofluorescence for eosinophil granule major basic protein (MBP). METHODS: We used both conventional histology (hematoxylin and eosin) and indirect MBP immunofluorescence histochemistry on colon biopsy specimens from patients with CC (n = 21) and from healthy controls (n = 9). Scoring of histological features was performed on hematoxylin and eosin-stained sections on a 0 to 3 scale. Eosinophil infiltration and degranulation, as quantified by extracellular MBP staining, were scored in each specimen on a 0 to 4 scale. RESULTS: The inflammatory infiltrate of the lamina propria, the thickness of the collagen band, the numbers of intraepithelial lymphocytes, and degree of epithelial cell damage were all significantly increased in patients with CC as compared to controls (p < 0.0001). Scores for both eosinophil infiltration and degranulation were also significantly higher in the CC group compared to controls (p < 0.0001). The degree of infiltrating eosinophils by hematoxylin and eosin was correlated with eosinophil infiltration and degranulation by MBP immunostaining; however, no other correlations were found between eosinophil infiltration or degranulation by immunofluorescence and any of the histological parameters measured in the CC group. CONCLUSIONS: Eosinophil infiltration and degranulation are increased in the colonic mucosa of patients with CC compared to healthy controls. Eosinophils and their cytotoxic granule proteins could be involved in the pathogenesis of CC. Further studies will be necessary to elucidate the mechanisms of eosinophil activation in CC.

Adult↗
PubMed1999

Influence of male gonadal hormones on the parasitemia and humoral response of male Calomys callosus infected with the Y strain of Trypanosoma cruzi.

Effects of orchiectomy on male Calomys callosus infected with the Y strain of Trypanosoma cruzi were studied. Male C. callosus of the same age and weight were divided into three groups: intact, sham operated, and castrated. After 1 month they were inoculated (i.p.) with 4000 blood trypomastigotes. Parasitemia was lower in orchiectomized animals than in the intact and sham groups. Hormone replacement with decanoate testosterone raised the parasitemia of castrated animals to levels similar to those of their intact and sham counterparts. Antibody levels were monitored by complement-mediated lysis. The trypomastigote lysis percentage varied through the course of infection, according to hormonal status and number of parasites during the acute phase. The most significant differences were found on the 30th day after infection, when lytic antibodies of intact males were high compared to the orchiectomized and sham groups. Higher resistance with lower lysis indexes were observed after orchiectomy, compared to intact and sham males.

Animals↗
PubMed1998

Eosinophilia and gastrointestinal symptoms after ingestion of shiitake mushrooms.

BACKGROUND: Shiitake mushrooms are a dietary staple in Asia and are increasingly popular worldwide. A cholesterol-lowering study with shiitake showed that 17 of 49 participants withdrew because of rash or abdominal discomfort, and two had marked eosinophilia. One of these latter participants was subsequently challenged for 14 days with shiitake powder and again had eosinophilia. OBJECTIVE: We investigated whether ingestion of shiitake mushroom powder induces eosinophilia or symptoms. METHODS: We studied 10 normal persons. Each participant ingested 4 gm shiitake powder (open label) daily for 10 weeks (trial 1), and the protocol was repeated in these same subjects after 3 to 6 months (trial 2). Blood counts and serum samples were obtained biweekly (trial 1) or weekly along with stool specimens (trial 2). Eosinophil major basic protein and IL-5, IgE, and IgG antishiitake antibodies were measured in sera. Eosinophil-derived neurotoxin was measured in stool extracts. We defined responders as subjects having peak eosinophil counts four or more times their average baseline counts. RESULTS: Each trial had four responders, and trial 2 had one new and three repeat responders. Eosinophilia ranged from 400 to 3900/mm3. Responders had increased blood eosinophils, serum major basic protein, stool eosinophil-derived neurotoxin, and factors that enhanced eosinophil viability. Antishiitake IgE was not detected, and antishiitake IgG increased in two responders. Gastrointestinal symptoms coincided with eosinophilia in two subjects. Symptoms and eosinophilia resolved after discontinuing shiitake ingestion. CONCLUSIONS: Daily ingestion of shiitake mushroom powder in five of 10 healthy persons provoked blood eosinophilia, increased eosinophil granule proteins in serum and stool, and increased gastrointestinal symptoms. Shiitake ingestion suggests a model to study the eosinophil's role in the blood and gastrointestinal tract. Finally, our report raises concerns of possible adverse systemic reactions to this increasingly popular food.

Adult↗
PubMed1998

Molecular resolution of marine turtle stock composition in fishery bycatch: a case study in the Mediterranean.

Based on an extensive sampling regime from both nesting populations and bycatch, frequency analyses of mitochondrial (mt) DNA control region haplotypes in the Mediterranean were used to assess the genetic structure and stock composition of the loggerhead sea turtle, Caretta caretta, in different marine fisheries. The analyses show the following. (i) In drifting longline fisheries working in Mediterranean pelagic habitats 53-55% of turtles caught originated from the Mediterranean stock; (ii) In bottom-trawl fisheries all turtle bycatch is derived from this regional stock; (iii) This regional stock contribution to fishery bycatch suggests that the population size of the Mediterranean loggerhead nesting population is significantly larger than previously thought. This is consistent with a recent holistic estimate based on the discovery of a large rookery in Libya. (iv) Present impact of fishery-related mortality on the Mediterranean nesting population is probably incompatible with its long-term conservation. Sea turtle conservation regulations are urgently needed for the Mediterranean fisheries. (v) The significant divergence of mtDNA haplotype frequencies of the Turkish loggerhead colonies define this nesting population as a particularly important management unit. Large immature and adult stages from this management unit seem to be harvested predominantly by Egyptian fisheries. (vi) Combined with other data, our findings suggest that all the nesting populations in the Mediterranean should be considered as management units sharing immature pelagic habitats throughout the Mediterranean (and possibly the eastern Atlantic), with distinct and more localized benthic feeding habitats in the eastern basin used by large immatures and adults. (vii) Between the strict oceanic pelagic and the benthic stages, immature turtles appear to live through an intermediate neritic stage, in which they switch between pelagic and benthic foods.

Animals↗
PubMed1997

Chicken-embryo fibroblasts produce two types of interferon upon stimulation with Newcastle disease virus.

Controversy has long surrounded the question of whether chickens, like mammals, can produce two types of interferon (IFN). Recently, type-I and type-II chicken IFNs have been cloned. Our study focuses on the further characterization of native fibroblast and spleen IFNs and shows that chicken embryo fibroblasts (CEFs) produce a mixture of type-I and type-II IFNs. IFN was purified by three different methods, controlled pore-glass chromatography, ion-exchange chromatography and preparative SDS-PAGE. Three protein bands showing IFN-like anti-viral activity, from CEFs which had been virus-stimulated for IFN production, were detected at 25, 27 and 29 kDa. Polyclonal antibodies produced against these bands showed partial cross-reaction with purified media from mitogen-stimulated spleen cells in ELISA, western blot analysis and anti-viral activity neutralization assay. Differences between purified conditioned media from CEF and spleen were found with respect to the stimulation of macrophages for nitric oxide production, pH stability and signal transduction pathways; only CEF IFN activated the IFN-stimulated gene factor-3 complex, whereas both CEF and spleen IFNs activated the IFN regulatory factor-1 gene. These findings concur with the differences that are known to exist between mammalian type-I and type-II IFNs. Attempts at sequencing the 25 and 27 kDa proteins by Edman degradation yielded evidence of N-terminal blockage.

Animals↗
PubMed1997

Increased eosinophil granule proteins in gut lavage fluid from patients with inflammatory bowel disease.

OBJECTIVE: To explore the potential role of eosinophils in the pathogenesis of inflammatory bowel disease (IBD). DESIGN: We measured the concentrations of eosinophil granule proteins-namely, major basic protein, eosinophil peroxidase, eosinophil cationic protein, and eosinophil-derived neurotoxin-in gut lavage fluid. MATERIAL AND METHODS: Ten healthy persons and 17 patients with IBD (9 with Crohn's disease and 8 with ulcerative colitis) underwent gut lavage. Each study subject submitted an early specimen when lavage effluent became liquid and a late specimen when the output became clear. The concentrations of the granule proteins were measured by immunoassay. RESULTS: The median concentrations of eosinophil-derived neurotoxin and eosinophil cationic protein were significantly higher in patients with IBD than in control subjects for both early and late lavage specimens. Excretion of eosinophil peroxidase was also significantly higher in patients with IBD than in the healthy control subjects, but only in the early specimens. No differences were noted in the concentrations of any of the proteins between patients with ulcerative colitis and those with Crohn's disease. CONCLUSION: Concentrations of eosinophil granule proteins were increased in whole gut lavage fluid from patients with IBD in comparison with healthy control subjects. These results encourage further studies of the role of eosinophils in the pathogenesis of IBD.

Adult↗
PubMed1996

In situ indirect fluorescent antibody: a new specific test to detect ongoing chagasic infections.

In situ immunofluorescence assay (ISIFA) was developed for the selection for treatment of chronically infected chagasic patients and their follow-up. Trypomastigotes flash fixed in situ on microscopic slides with 0.025% glutaraldehyde were used as antigen. ISIFA results were compared with complement-mediated lysis (CoML), membrane immunofluorescence (MbIFA), immunofluorescence assay (IFA) with epimastigotes, and xenodiagnosis (XENO). ISIFA was able to distinguish nontreated chagasic patients (geometric mean titer [GMT] = 180) and treatment failures (GMT = 160) from those considered successfully treated (GMT = 25). ISIFA revealed a high sensitivity and titers of 80 or higher detected 98.6% of patients with active infections, even in those with negative XENO, CoML, or MbIFA. Specificity evaluated in 63 sera from other infections, including leishmaniasis and autoimmune diseases, was 98%. IFA used in routine diagnostic procedures exhibited similar results in all groups, irrespective of therapy.

Adult↗
PubMed1994

Use of the Greenfield filter in patients with major trauma.

Patients with major trauma often cannot be given the benefit of preventive measures such as pneumatic compression boots and low-dose heparin against pulmonary embolism. The Greenfield filter is accepted as a safe and effective method of prophylaxis of this complication. The aim of this study was to evaluate the efficacy of placement of the Greenfield filter in 161 patients with major trauma. Between January 1984 and July 1988, 94 patients with an injury severity score (ISS) of > 16 were treated. This score is predictive of a mortality rate of at least 10% and defines major trauma based on anatomic injury. Some 20% (19 of 94) of these patients developed deep vein thrombosis despite standard prophylactic measures and 8% (eight of 94) suffered pulmonary embolism, two of which were fatal. Pulmonary embolism occurred without antecedent evidence of deep vein thrombosis in another 15% of patients (14 of 94), three of which caused death. From August 1988 until July 1992, of 67 other patients with an ISS > 16, 13% (nine of 67) developed deep vein thrombosis and 1% (one of 67) had a pulmonary embolism; this was not statistically significant (P > 0.25). Of these 67 patients who were considered to be at high risk of pulmonary embolism, because of a contraindication to anticoagulation or physical impediment to sequential compression boots, 29 had prophylactic placement of a Greenfield filter. No pulmonary emboli occurred in these patients. During long-term follow-up (mean 32.8 (range 4-58) months), 84% of the surviving patients (21 of 25) underwent duplex ultrasonography of the inferior vena cava; patency of the vessel was confirmed in all patients.

Adolescent↗
PubMed1993

Angioscope-assisted endovascular occlusion of venous tributaries: preclinical studies.

The feasibility of angioscope-assisted occlusion of venous tributaries from within a vein using a steerable 'shaped-memory' nickel-titanium (nitinol) alloy catheter and occlusion coils was evaluated. An initial series of tests was designed to establish the necessary pressure (275 p.s.i., 1897.5 kPa), time (1.5 s) and volume (2.5 ml normal saline) requirements for hydraulic delivery of platinum occlusion coils from the nitinol catheter through a 3-Fr tracking catheter. In a second series, 25 side branches of the saphenous vein in 11 amputated limbs were visualized angioscopically and cannulated with the nitinol catheter under angioscopic and fluoroscopic surveillance to determine whether the catheter tip could be positioned and coils deployed. In a third series of studies, ten canine femoral vein tributaries were successfully cannulated with an 8-Fr nitinol catheter and 19 occlusion coils delivered under angioscopic surveillance. Fluoroscopy verified coil placement and all embolized venous tributaries were thrombosed. An ideal approach for femoropopliteal in situ saphenous vein bypass would allow the surgeon to divide saphenous vein valves while occluding venous side branches from within the saphenous vein. These initial studies demonstrate that the nitinol catheter can occlude venous tributaries from within a vein by coil embolization. Further development of this technique for clinical investigation is warranted.

Angioscopes↗
PubMed1991

The disabled athlete: an approach.

Treatment of the disabled athlete should allow the athlete to maximize his remaining abilities and perform at his highest level. The emotional and psychological benefits to the athlete are tremendous, as the athlete will have a greater feeling of self-esteem.

Adolescent↗
PubMed1990

Objective autorefraction in posterior chamber pseudophakia.

Automated refraction with the Canon RK-1 Autoref keratometer was evaluated in 110 eyes (110 patients) six to eight weeks after they had undergone extracapsular cataract extraction with posterior chamber intraocular lens implantation and achieved a best corrected visual acuity of at least 6/12. Autorefraction readings were obtained in 100 (91%) of these eyes. The agreement between autorefraction and clinical refraction data was 98% for spherical equivalence less than 0.51 dioptres (D), 95% for sphere power less than 0.51D, 94% for cylinder power less than 0.51D, and 85% for cylinder axis less than 11 degrees. Autorefraction can provide acceptably accurate postoperative refraction values in pseudophakic eyes.

Equipment and Supplies↗
PubMed1987

Use of ambulatory electrocardiographic monitoring to identify high-risk patients with congenital complete heart block.

To define the long-term natural history of congenital complete heart block, we followed 27 patients prospectively by means of frequent ambulatory electrocardiographic (ECG) recordings for a mean (+/- SD) of 8 +/- 3 years. During that time, 8 of the 13 patients with a mean daytime heart rate below 50 bpm (Group A) had cardiac complications such as sudden death, syncope, presyncope, or excessive fatigue. Six of the eight patients had additional ECG findings that suggested an instability of the junctional escape mechanism. These findings included nocturnal junctional exit block (three patients), little or no change in the junctional rate with physical activity (three patients), and associated tachyarrhythmias (three patients). None of the 14 patients with a mean daytime heart rate of 50 bpm or more (Group B) had an adverse clinical outcome, and 5 of the 13 patients in Group A also remained well. Among the five patients in stable condition in Group A, three had no evidence of an unstable junctional mechanism. We conclude that patients with a mean daytime junctional rate below 50 bpm and other evidence of an unstable junctional escape mechanism should probably undergo prophylactic pacemaker implantation. Since junctional exit block and tachyarrhythmias sometimes appear first during follow-up, the method of risk stratification employed in this study depends on serial ambulatory ECG recordings.

Adolescent↗
PubMed1987

Posterior synechiae after glaucoma operations: aggravation by shallow anterior chamber and pilocarpine.

Posterior pupillary synechiae affect a proportion of eyes subjected to iridectomy with or without drainage operation because (1) aqueous humour bypasses the pupil; (2) traumatic iridocyclitis occurs; (3) there is immobility of the iris in the iridectomy sector; (4) in eyes with angle closure glaucoma closer apposition of the iris to the anterior lens capsule increases the tendency; (5) pilocarpine aggravates (4) both in angle closure glaucoma and open angle glaucoma and produces a small immobile pupil facilitating pupillary membrane formation (occlusio pupillae). Pilocarpine should be avoided if possible as medical treatment at any time after a drainage operation. A beta blocker is the drug of choice. To eliminate posterior synechiae over a fair number of degrees of pupil (say 30 degrees) sector iridectomy can be done.

Aged↗
PubMed1987

Blindness in schoolchildren: importance of heredity, congenital cataract, and prematurity.

Of 99 children in the Royal Blind School, Edinburgh (which serves Scotland and part of N E England), 15 had optic atrophy (hydrocephalus 4, intracranial haemorrhage 2, prematurity 2, fetal distress 2, birth asphyxia 2, cerebral atrophy 1, cardiac arrest during hernia operation 1, and leukaemia 1). Fourteen had congenital cataract, 12 congenital retinal aplasia (Leber's congenital amaurosis) and 11 retinopathy of prematurity. There were small numbers in many other diagnostic categories, including three with non-accidental head injury. Mental retardation, spasticity, and nystagmus were frequent other correlates in all diagnostic categories. 'Very probably hereditary' was a conservative attribution in 36, while 'probable' seemed appropriate for 12-that is, almost 48% were hereditary. Only about 11 cases might have been prevented through genetic counselling, which testifies to the frequency of autosomal recessive hereditary disease, although no parents were consanguineous.

Adolescent↗
PubMed1987

Evaluation of a new dressing in the treatment of sports-related skin lesions.

Twenty-seven players with superficial wounds (abrasions, turf burns, and blisters) were treated with a new Hydroactive dressing. We conclude that this dressing provides an excellent alternative to other forms of treatment since it is easy to use, comfortable, hypoallergenic, and provides impressive healing results.

Adult↗
PubMed1986

Probably Norrie's disease due to mutation. Two sporadic sibships of two males each, a necropsy of one case, and, given Norrie's disease, a calculation of the gene mutation frequency.

Two sibships, each with two affected males but no other affected family members, are described. All four patients at birth had small eyes with white masses visible behind clear lenses. Support for a diagnosis of Norrie's disease lies in the probable mental retardation and sudden death of one child and mental retardation in the other in one of the families, and strong support in the sensorineural deafness in one child in the other family. A necropsy was performed on the dead child. Both eyes showed the retinae to be totally non-attached. The optic nerves were thin. If the diagnosis is Norrie's disease (highly probable), the birth of the second affected child in each family supports the postulate of a mutation in the X chromosome of a germ cell of a maternal grandparent or an earlier maternal ancestor, no previous member of the family having been affected. That implies a 50% risk of the disease in future male siblings and a 50% risk of the carrier state in female sibs. When only one child is affected, the explanation could also be a mutation in that individual. Given Norrie's disease, we have calculated a mutation rate of 3.9 per million chromosomes in the Scottish population--remarkably similar to the mutation rates calculated for many dominant diseases. A diagnosis of autosomal recessive non-attachment of retina implies a 25% risk to later siblings.

Blindness↗