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Biomedical subjects

Michael S Wilson

Publications and source records attributed to Michael S Wilson.

14 recordsLinked to original sources
PubMed2007

Zonisamide for bipolar depression.

In recent years, research into bipolar depression has increased. Each year, more studies are published using different agents to treat this condition. In addition to effectiveness and tolerability, bipolar depression research has sought agents that do not induce cycling or mania. This paper evaluates an open-label pilot study on zonisamide for bipolar depression that examined the effectiveness and tolerability of this agent while observing for any switch to mania. Zonisamide was found to have a very low switch rate and modest effectiveness. However, a high dropout rate was observed--mostly due to side effects. Until further research is available, zonisamide is not recommended as a first-line treatment for bipolar depression.

Bipolar Disorder↗
PubMed2006

Multiplex measurement of seven tumor markers using an electrochemical protein chip.

An electrochemical immunosensor for performing multianalyte measurements of tumor markers is described. The sensor consisted of an array of immunosensing electrodes fabricated on a glass substrate. Each electrode contained a different immobilized antigen and was capable of measuring a specific tumor marker using electrochemical enzyme-based competitive immunoassay. Using this arrangement, multiple analytes could be measured simultaneously by performing the technical operations for a single assay. The biosensor was used to measure the concentrations of seven important tumor markers: AFP, ferritin, CEA, hCG-beta, CA 15-3, CA 125, and CA 19-9. The sensor had excellent precision and accuracy and was comparable in performance to single-analyte ELISAs (1.9-8.1% interassay CV; <2 ng/mL (or units/mL) detection limit for most analytes). Multianalyte assays provide significant advantages over single-analyte tests in terms of cost per test, labor, test throughput, and convenience. We anticipate that chip-based sensors, as described herein, will be suitable for the mass production of economical, miniaturized lab-on-a-chip devices that will have applications in a wide range of clinical, environmental, and biodefense applications.

Antigens, Neoplasm↗
PubMed2006

A synthetic approach toward nitiol: construction of two 1,22-dihydroxynitianes.

Synthetic work toward the total synthesis of nitiol has culminated in the construction of two epimeric hydroxylated derivatives, the 1,22-dihydroxynitianes. Key stereodefining steps in the construction of the A-ring fragment (13) were the use of a siloxy-epoxide rearrangement reaction, a Pauson-Khand reaction, a Norrish 1 photochemical cleavage reaction, and a highly regio- and stereoselective hydrostannylation reaction of an ynoate. The stereochemistry of the synthetically challenging C-ring fragment (20) was established using an Ireland-Claisen reaction and a Grubbs ring-closing metathesis process as key steps. The 12-membered B-ring of the nitiane skeleton was constructed using a copper-promoted Stille cross-coupling and a Kishi-Hiyama-Nozaki carbonyl addition reaction. Unfortunately, the carbonyl addition reaction produced hydroxyl functionality that could not be selectively removed. Consequently, a synthesis of epimeric 1,22-dihydroxynitianes, which are compounds that are structural hybrids of two natural products, nitiol and variculanol, was completed.

Gentianella↗
PubMed2006

Electrochemical multianalyte immunoassays using an array-based sensor.

A novel amperometric biosensor for performing simultaneous electrochemical multianalyte immunoassays is described. The sensor consisted of eight iridium oxide sensing electrodes (0.78 mm(2) each), an iridium counter electrode, and a Ag/AgCl reference electrode patterned on a glass substrate. Four different capture antibodies were immobilized on the sensing electrodes via adsorption. Quantification of proteins was achieved using an ELISA in which the electrochemical oxidation of enzyme-generated hydroquinone was measured. The spatial separation of the electrodes enabled simultaneous electrochemical immunoassays for multiple proteins to be conducted in a single assay without amperometric cross-talk between the electrodes. The simultaneous detection of goat IgG, mouse IgG, human IgG, and chicken IgY was demonstrated. The detection limit was 3 ng/mL for all analytes. The sensor had excellent precision (1.9-8.2% interassay CV) and was comparable in performance to commercial single-analyte ELISAs. We anticipate that chip-based sensors, as described herein, will be suitable for the mass production of economical, miniaturized, multianalyte assay devices.

Animals↗
PubMed2005

Electrochemical immunosensors for the simultaneous detection of two tumor markers.

The microfabrication of electrochemical immunosensors for the simultaneous detection of two protein analytes is described. The sensors consisted of two iridium oxide electrodes (1-mm diameter) patterned on a glass substrate. Capture antibodies were immobilized on the porous iridium oxide electrodes by covalent attachment using (3-aminopropyl)triethoxysilane and glutaraldehyde. The spatial separation of the electrodes (2.5 mm) enabled simultaneous electrochemical immunoassays to be conducted without cross-talk between the electrodes. Proteins were measured using electrochemical ELISA, and detection was achieved by electrochemically oxidizing alkaline phosphatase-generated hydroquinone. Sensors for the simultaneous detection of goat IgG and mouse IgG, and for the tumor markers CEA and AFP, were developed. The sensors had detection limits of 1, 2, 1.2, and 1 ng/mL for goat IgG, mouse IgG, CEA, and AFP, respectively.

Alkaline Phosphatase↗
PubMed2004

Hydroquinone diphosphate: an alkaline phosphatase substrate that does not produce electrode fouling in electrochemical immunoassays.

Hydroquinone diphosphate (HQDP) was synthesized and compared to phenyl phosphate (PP) and 1-naphthyl phosphate (NP) as a substrate for alkaline phosphatase (AP) under electrochemical immunoassay (EIA) conditions. Voltammetric and amperometric experiments showed that electrochemical oxidation of hydroquinone (HQ), which is the AP hydrolysis product of HQDP, did not produce electrode passivation, even with repeated biosensor use. In contrast, phenol and 1-naphthol, the hydrolysis products of PP and NP, respectively, were shown to be irreversibly oxidized on the electrode surfaces, and produced rapid electrode passivation, resulting in complete loss of electrode signal. When employed as AP substrate in an iridium oxide based EIA, HQDP produced significantly larger amperometric responses (117 microA/cm2) compared to PP (31 microA/cm2) and NP (27 microA/cm2). The results presented in this paper show that HQDP is an attractive alternative to commonly used AP substrates such as NP and PP. The substrate shows excellent hydrolytic stability, produces larger amperometric responses (than PP or NP), and does not produce sensor passivation.

Alkaline Phosphatase↗
PubMed2004

Novel amperometric immunosensors based on iridium oxide matrices.

Novel immunosensors based on antibodies immobilized in electrochemically grown iridium oxide (IrOx) thin film matrices have been developed. Antibody loading in the oxide was evaluated using a non-competitive electrochemical immunoassay for IgG. Anti-IgG loading in the oxide was found to be dependent on the concentration of anti-IgG present in the oxide growth step, with 400 microg/ml anti-IgG producing maximum amperometric responses. To study the potential analytical properties of the matrix, the dose-response behavior of the sensors was determined using optimized alkaline phosphatase-linked IgG immunoassay. Hydroquinone diphosphate (HQDP) was used as enzyme substrate and the oxidation of hydroquinone was detected amperometrically at +420 mV. The sensors displayed a linear dose-response behavior for IgG concentrations between 10 and 200 ng/ml, saturating above 600 ng/ml, and had a low detection limit of 8 ng/ml.Finally, the method was used to produce sensors containing immobilized anti-transferrin. Using a non-optimized electrochemical immunoassay for human transferrin (HT), dose-response behavior was observed for HT concentrations between 100 and 600 ng/ml.The results presented in this paper show that IrOx matrices represent a new method for immunosensor fabrication. The oxide acts as a hydrophilic, highly porous, three-dimensional matrix that can immobilize antibodies and retain their activity. The method is attractive because it offers the potential for high antibody loadings and is suitable for mass production of sensors in an easy and economical manner.

Adsorption↗
PubMedDate not supplied

Comorbid anxiety disorders and divalproex sodium use among partial hospital patients with psychotic disorders.

We conducted this study to determine anxiety disorder comorbidity and divalproex sodium use among 26 patients with psychotic disorders after their referral to a partial hospital. Each subject was diagnosed by structured interview, and 4 Brief Psychiatric Rating Scale (BPRS) items associated with agitation were assessed: anxiety, hostility, excitement, and tension. Subjects' medical records were then examined to determine discharge diagnoses from referring inpatient facilities as well as current medication use. Although we diagnosed many anxiety disorders, none was identified during hospitalization. Divalproex use was not associated with anxiety disorder frequency. Divalproex patients had significantly lower BPRS anxiety, tension, and excitement scores, as well as total BPRS agitation scores (P < .05). Our findings suggest that anxiety disorders are unrecognized among psychotic patients and that treatment guidelines for concurrent anxiety are needed.

Adult↗
PubMedDate not supplied

A noncontact wound measurement system.

The instrument described in this manuscript was developed to perform objective, quantitative measurements of wound healing, which will enable service providers to assess, improve, and individualize the treatment given to each wound patient. It was designed to produce measures that will enable the care provider to assess the current state of the wound as well as gain insight into the time course of the wound healing by comparing the series of wound data collected over time. The record provided by the instrument could also assist in legal defense; a need that, unfortunately, cannot be ignored. The system uses a structured lighting pattern captured on a digital photograph of a wound to calculate the area and volume of debrided wounds. We used plaster molds with spherical indentations to represent various wounds to evaluate the precision of the system. Results indicate that when at least 144 of the data points in the picture lie within the wound borders, the surface area and wound volume are repeatable and the precision is within +/-3% of the calculated values based on the geometry of the spherical indentation.

Anthropometry↗