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Biomedical subjects

E Becerra

Publications and source records attributed to E Becerra.

17 recordsLinked to original sources
PubMed2004

[Ocular presentation in Wegener granulomatosis].

CASE REPORT: A 71 year-old female presented with bilateral conjunctivitis, scleritis and peripheral ulcerative keratitis. Ancillary tests showed presence of anti-neutrophil cytoplasmic antibodies, with diffuse granular cytoplasmic immunofluorescence staining (ANCAc). Conjunctival biopsy showed necrotizing vasculitis in small vessels. Diagnosis of Wegener Granulomatosis (WG) was established and upper respiratory affection detected. Treatment with megadoses of cyclophosphamide and corticoids was initiated and remission of the disease was obtained. DISCUSSION: WG is a potentially lethal systemic vasculitis in which ocular involvement may be the first clinical presentation. Scleritis and peripheral ulcerative keratitis indicate systemic involvement, highlighting the importance of prompt diagnosis and treatment.

Aged↗
PubMed2001

A robust multi-syringe system for process flow analysis. Part 3. Time based injection applied to the spectrophotometric determination of nickel(II) and iron speciation.

A new software-controlled time-based system for sample or reagent introduction in process flow injection analysis was developed. By using a multi-syringe burette coupled with one multi-port selection valve, the time-based injection of precise known volumes was accomplished. Characteristics and performance of the injection system were studied by injecting an indicator in a buffered carrier. Two multi-syringe time-based injection (MS-TBI) systems were implemented: first, the injection of a sample in a multiple-channel manifold where the sample would sequentially merge and react with different reagents, and second, the sequential injection of several solutions (sample and reagents) into a particular flowing stream. The first system was applied to the spectrophotometric determination of nickel(II) in diluted samples from the acidic nickel ore leaching process, by using ammonium citrate as carrier, a saturated solution of iodine as oxidizing agent and alkaline dimethylglyoxime as chromogenic reagent. The sampling frequency attained was 57 h-1. Determinations on process samples compared well at the 95% confidence level with the reference values obtained by ICP-OES. The second time-based injection system was applied to the speciation of iron. Total iron and iron(II) concentrations were separately and sequentially determined using 1,10-phenanthroline in acetic buffer medium as reagent. The developed manifold allowed the optional use of two different carrier solutions, containing or not containing ascorbic acid, for performing the separate determinations. Also, in the sequential procedure, plugs of reducing carrier were alternatively intercalated before the sample injections used for total iron determinations. Sampling frequencies of 68 injections per hour were routinely used. Accuracy was assessed by analyzing synthetic known mixtures of Fe(III) and Fe(II) standard solutions. Recoveries of 98-100.5% with a maximum relative standard deviation of 3.6% were found. Results obtained for various samples of fertilizers agreed well with those attained by the standard batch procedure.

Journal Article↗
PubMed1999

A high-resolution in vitro bioassay to identify neurons containing red pigment concentrating hormone

The release of red pigment concentrating hormone (RPCH) by single peptidergic neurons of the crayfish X organ/sinus gland system (XO-SG) was demonstrated using a novel in vitro bioassay in which XO neurons were co-cultured with tegumentary erythrophores. Local retraction of the pigmentary matrix within filipodia from erythrophores plated next to presumptive RPCH-containing neurons suggest spontaneous hormone release. Topical application of synthetic RPCH onto long filipodia also produced a local response. The time course of pigmentary matrix aggregation depended on the dose of synthetic RPCH. The effect of peptide on the cultured target cells was blocked by a polyclonal antiserum against RPCH. In co-culture conditions, the time course of pigmentary matrix aggregation was accelerated when presumptive RPCH-containing neurons were depolarized by intracellular current injection or by voltage-clamping to activate the Ca2+ current. The aggregation response evoked by these maneuvers was similar to that obtained with synthetic RPCH at a concentration of 1 fmol l-1. The immune serum was also used to identify a subset of 3-7 immunoreactive neurons localized in the external rim of the XO close to the medulla interna. Under culture conditions, this subset of neurons corresponded to the cells that induced the erythrophore response.

Journal Article↗
PubMed1994

Regional distribution and immunocytological localization of red pigment concentrating hormone in the crayfish eyestalk.

A polyclonal antibody was raised against synthetic tyrosinated crustacean red pigment concentrating hormone (RPCH-Tyr) with the sequence Tyr-Leu-Asn-Phe-Ser-Pro-Gly-Trp-NH2 with a tryptophan amide at the carboxyl terminal end. Its specificity was tested in comparison with peptides of similar structure. It appears to recognize the three to five residues near the carboxyl terminal. Native RPCH in the crayfish eyestalk was determined by two methods: (a) immunoenzymatic assay (ELISA) using the aforementioned antibody; and (b) bioassay on segments of isolated crayfish tegumentary epithelium. The unitary content in whole eyestalks was 5.5 +/- 1.0 nmol for samples (n = 18) taken at night. The regional distribution of RPCH content in the eyestalk was determined. The greatest proportion (40%) was found in the sinus gland, and the lowest in the retina plus lamina ganglionaris (6%). The medulla interna, medulla externa, and medulla terminalis contained similar proportions (about 16% each). The highest specific content was in the sinus gland (65.0 vs 24.4 pmol/micrograms protein for the whole eyestalk). Immunopositive neurons were identified in the various regions of the eyestalk. In 22 preparations, an average of 7 cells were identified in the ventromedial rim of the medulla terminalis, sending axons to the sinus gland, after branching in the neuropil of the medulla terminalis. Dorsally, 2 cells were identified in the medulla interna and 4 large cells and 11 small cells were located in the medulla externa in close proximity to the lamina ganglionaris: none of these cells appeared to project to the sinus gland. Profuse immunopositive fibers were found in the lamina ganglionaris projecting distally toward the base of the retina. Immunopositive axons were also found in the optic nerve.

Amino Acid Sequence↗
PubMed1992

Sinus pericranii: radiological and etiopathological considerations. Case report.

Sinus pericranii is a rare vascular anomaly involving an abnormal communication between the extracranial and intracranial circulations. A case of frontal sinus pericranii is presented which appeared to be a posttraumatic sinus because it developed 2 years after a cranial injury. However, the presence of vascular endothelium in the pathological examination and its association with a vascular anomaly (persistent trigeminal artery) suggested a congenital origin. The lesion, pericranial blood sinuses, and bone were totally removed. The computerized tomography, angiography, and magnetic resonance imaging findings are presented. The literature is reviewed and the pathogenesis of sinus pericranii is discussed.

Adult↗
PubMed1991

[Cardiac transplantation: economizing cyclosporin A by including ketoconazole in the immunosuppressive schedule].

Use of cyclosporin A has improved survival in patients submitted to cardiac transplantation. However, high cost of cyclosporin poses a problem for many patients in Chile. Ketoconazole is able to reduce hepatic metabolism of cyclosporin and thus prolong therapeutic levels. A 74 to 82% reduction in cyclosporin requirements was obtained in a cardiac transplant patient by adding ketoconazole. No renal damage was detected. Therefore, this drug association may help extend cardiac transplantation programs in Chile.

Adult↗
PubMed1986

Are there indications for heterotopic heart transplantation in 1986? A 2- to 11-year follow-up of 49 consecutive patients undergoing heterotopic heart transplantation.

In the 9-year period between November 1974 and December 1983, 49 patients underwent heterotopic heart transplantation at Groote Schuur Hospital. Eight patients subsequently underwent a further transplant procedure, and one of these a third transplant (58 transplants in 49 patients). Conventional immunosuppressive therapy (azathioprine, corticosteroids, and rabbit antithymocyte globulin) was used in 47 cases (81%), and cyclosporine and conventional immunosuppression in 11 (19%). Follow-up (to 1st January 1986) has been for a minimum of 2 and a possible maximum of 11 years. Forty-one of the 49 patients (85%) have subsequently died, mean survival of this group being 18.5 months. Mean survival of the 8 patients alive is 74 months. One-year survival has been 55% and 5-year survival 22%. In light of this experience, it would seem to us that the indications for heterotopic transplantation have now greatly diminished. There would still appear to be a place for it, however, when the donor heart is small in relation to the mass of the recipient, when there is a possibility of myocardial recovery following the resolution of a myocarditis, and when there is an elevated pulmonary vascular resistance which may make orthotopic transplantation hazardous. Heterotopic heart transplantation may also be indicated when the recipient circulation is failing rapidly despite maximal medical support, and therefore transplantation is urgent.

Adolescent↗
PubMedDate not supplied

Pure squamous carcinoma of the breast. Report of a case diagnosed by aspiration cytology.

A case of pure squamous carcinoma of the breast diagnosed by needle aspiration cytology is presented. The three conditions required for that diagnosis were fulfilled: (1) an absence of elements other than malignant epidermoid cells, (2) the independence of the lesion from adjacent dermal structures, and (3) the exclusion of other squamous carcinomas in the patient. Other well-documented cases of this entity are reviewed.

Biopsy, Needle↗
PubMedDate not supplied

Twenty years of heart transplantation at Groote Schuur Hospital.

Between December 1967 and July 1987, 110 heart transplantations (61 heterotopic and 49 orthotopic) and 12 heart-lung transplantations were done at Groote Schuur Hospital in Cape Town, South Africa. Twelve procedures were retransplantations, including two third interventions. The patients were divided into three groups: Group A (n = 55) from 1967 to 1982 received so-called conventional treatment of azathioprine, methylprednisolone, and antithymocyte globulin. Group B (n = 15) from 1983 to 1984 had cyclosporine in high dosages together with methylprednisolone. Group C (n = 30) received quadruple drug therapy of low-dosage cyclosporine, together with azathioprine, methylprednisolone in lower dosages, and antithymocyte globulin (for the first 4 to 6 days and rescue antithymocyte globulin for severe rejection). From Group A, nine of 55 patients are alive up to 17 years after transplantation. The main causes of death were acute rejections and infections (in 60% altogether). From group B, six of 15 patients are alive. Acute rejections and infections were the causes of death in 12% of the patients, but multiple organ failure was a major cause in 24% most probably because of the high dosages of cyclosporine. From group C, 23 of 30 patients have survived. In this group the results after heterotopic heart transplantation do not differ significantly from orthotopic transplantation, which justifies this procedure in particular situations. If all heterotopic and orthotopic transplantations are compared, orthotopic procedures have a substantially better outcome. With the modified immunosuppressive regimen (group C) combined with precise donor and recipient selection and more sophisticated rejection monitoring, the actuarial survival rate within the last 12 months is 94%.

Antilymphocyte Serum↗