Search PubMed⌕ Search

Biomedical subjects

W Wong

Publications and source records attributed to W Wong.

222 records · Page 13Linked to original sources
PubMedDate not supplied

Bilateral occlusion of the trunk of the middle cerebral artery. Results of an international randomized trial. The EC/IC Bypass Study Group.

Bilateral occlusion of the middle cerebral artery (MCA) trunk theoretically should be a very severe condition, but its actual prognosis has never been studied. Nine of 1,377 patients (7 Asians, 1 Black, 1 Caucasian) from the Cooperative Study of Extracranial/Intracranial Arterial Anastomosis were found to have atherosclerotic bilateral occlusion of the middle cerebral artery (MCA) trunk before entering the trial. Three presented with a stroke followed by a contralateral stroke, two experienced a unilateral stroke, two had a unilateral stroke preceded by ipsilateral TIAs, one had a unilateral stroke preceded by TIAs on both sides and one experienced isolated unilateral TIAs. Retrograde filling to the distal MCA was universally present. During follow-up (mean: 45 months), only one (non-operated) patient had further cerebrovascular events, and ultimately a fatal stroke. One additional patient died of sepsis and one had a silent myocardial infarct. All survivors resumed their previous activities. This study shows that in bilateral MCA trunk occlusion, the long-term prognosis is reasonable in the patients who do not present with a devastating stroke.

Adult↗
PubMedDate not supplied

Intradiscal electrothermal therapy (IDET).

The indications of discography include situations in which there is inconsistency between the imaging and physical findings. Discography may also be performed prior to planned disc therapy such as percutaneous diskectomy or IDET. The diagnostic goal of the diskcogram is to reproduce the patient's original pain pattern by injection of the disc. If it is determined that the origin of the patient's back pain is diskcogenic, disc therapy can be provided by either surgical or non-surgical means. The non-surgical disc therapy includes steroid injections, IDET, or even percutaneous diskectomy.

Adult↗
PubMedDate not supplied

Stability and purity profile of gonadorelin acetate: a high-purity gonadotropin-releasing hormone.

Recently, several reports of adverse reactions after pulsatile GnRH (gonadorelin hydrochloride) infusion therapy have appeared in the medical literature. Although the cause of these reactions has been associated with GnRH itself, the contributions of impurities and degradation products in the administered drug have not been determined, suggesting that the use of high-purity material may be advantageous in controlling unwanted side effects. This study evaluates the purity and long-term stability of a new GnRH product, gonadorelin acetate (Lutrepulse, Ortho Pharmaceutical Corporation). Both the purity and potency of the drug substance, the lyophilized product for injection, and the reconstituted material that would be transferred to the infusion pump system were monitored using high-performance liquid chromatography. The gonadorelin acetate drug substance was found to be stable for at least 12 months when stored at 24 degrees C in 50% relative humidity, and showed no degradation even under accelerated storage conditions. Similarly, the lyophilized product also showed excellent stability for at least 18 months when stored at 24 degrees C in 50% relative humidity. Upon reconstitution, gonadorelin acetate was found to be stable for at least 45 days when stored at 24 degrees C or 37 degrees C.

Chromatography, High Pressure Liquid↗
PubMedDate not supplied

Molecular and cellular mechanisms of leukemic hemopoietic cell differentiation: an analysis of the Friend system.

Murine erythroleukemia (MEL or Friend) cells grown in culture and induced to differentiate into cells resembling orthochromatic normoblasts provide a suitable system for uncovering molecular and cellular mechanisms of hemopoiesis and for understanding globin gene regulation. Inducer-treated cells undergo an irreversible commitment to maturation and accumulate large amounts of hemoglobin. Clonal analysis of commitment of individual cells combined with biochemical measurements has revealed that MEL cell differentiation is a highly coordinated set of events (program) leading to the differentiated erythroid state. The developmental program of MEL cells consists of early and late processes. The early events appear to be membrane-mediated processes which operate independently of each other and lead to commitment to terminal maturation and hemoglobin synthesis. Inducer-treated cells express an ability to remember ("memory response") previous exposure to inducer and to continue their differentiation after discontinuous exposure to inducer; expression of "memory response" occurs early in differentiation and affects both the initiation of commitment and accumulation of globin mRNA in a similar manner in inducer-treated cells. Commitment to maturation appears to be the central process responsible for determining the pattern of gene expression, limitation of proliferative activity and nuclear condensation. Commitment, however, can occur independently of hemoglobin synthesis. Although initiation of commitment is associated with early membrane-mediated events (e.g., ion-transport), maintenance and completion of maturation erythroid state is a result of a number of cellular processes. These processes are discussed in relation to the molecular and cellular mechanisms of initiation and completion of MEL cell differentiation. The role of the MEL system as a model for studying mouse and human globin gene regulation is presented.

Animals↗