Biomedical subjects

A Sayah

Publications and source records attributed to A Sayah.

4 recordsLinked to original sources

PubMed2003

Enhanced sensitivity detection of protein immobilization by fluorescent interference on oxidized silicon.

We present a silicon chip-based approach for the enhanced sensitivity detection of surface-immobilized fluorescent molecules. Green fluorescent protein (GFP) is bound to the silicon substrate by a disuccinimidyl terephtalate-aminosilane immobilization procedure. The immobilized organic layers are characterized by surface analysis techniques, like ellipsometry, atomic force microscopy (AFM) and X-ray induced photoelectron spectroscopy. We obtain a 20-fold enhancement of the fluorescent signal, using constructive interference effects in a fused silica dielectric layer, deposited before immobilization onto the silicon. Our method opens perspectives to increase by an order of magnitude the fluorescent response of surface immobilized DNA- or protein-based layers for a variety of biosensor applications.

Adsorption↗

PubMed2001

Modular microsystem for epithelial cell culture and electrical characterisation.

We have realised a microsystem for the culture and electrical characterisation of epithelial cell layers for cell-based diagnostic applications. The main goal of this work is to achieve both cell culture and impedimetric and potentiometric characterisation on a single device. The miniaturised cell culture system enables the uses of scarce epithelial cells, as obtained from transgenic mice or from human biopsies. The device is completely modular and offers high flexibility: a polycarbonate membrane used as cell substrate is glued in between two moulded Polydimethylsiloxane (PDMS) layers to form a sandwich, which is placed between two stacks, containing the microfluidic channels and integrated measurement electrodes. The polycarbonate membrane sandwich can be removed, replaced or analysed at any time. We have characterised the impedimetric properties of our microsystem, demonstrated epithelial cell layer growth within it, and have done the initial electrical characterisation of epithelial cell layers.

Animals↗

PubMed1998

Field experience with prehospital advance directives.

STUDY OBJECTIVE: Some states have enacted legislation authorizing EMS providers to adhere to prehospital advance directives (ADs) in the terminally ill. This study was conducted to assess EMS providers' knowledge of and experience with prehospital ADs. METHODS: An anonymous survey was conducted of 142 EMS providers employed by a local, private ambulance service in the northeastern United States. The survey was administered during a 2-month period from January to March 1995. RESULTS: Of 142 participating providers, 106 (74.6%) completed questionnaires. Respondents included EMTs (61. 3%), paramedics (33.9%), and chair van operators (4.8%). The majority (58.6%) had at least 5 years of field experience. Almost all respondents (93.4%) were familiar with ADs, usually do-not-resuscitate orders. Most providers (78.3%) consider ADs before implementing extraordinary life support measures in terminally ill patients. Few (28.0%) have implemented prehospital ADs without medical control. The most commonly reported objections to withholding life support measures were fear of legal consequences, personal difficulty withholding care they are trained to provide, and ambiguity in the ADs received. Nearly all respondents (96.7%) support enactment of prehospital AD statutes. CONCLUSION: Most prehospital care providers recognize the need to withhold resuscitative care in terminally ill patients who have prepared ADs. However, a sizable minority fail to consider prehospital ADs as a routine part of their practice. The majority of our respondents support enactment of prehospital AD statutes to minimize confusion and provide legal authorization to limit resuscitation.

Advance Directives↗

PubMedDate not supplied

An occult cause of persistent nausea and vomiting.

We report a patient with multiple negative evaluations during emergency department visits and inpatient admissions for unexplained, intermittent nausea, vomiting, and abdominal pain. The etiology of her symptoms was not revealed until her 13th hospital visit, when head magnetic resonance imaging suggested active neurocysticercosis. Central etiologies should be considered for intractable nausea and vomiting in neurologically intact patients even if head computed-assisted tomography scan is negative.

Adult↗