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Biomedical subjects

M C Wong

Publications and source records attributed to M C Wong.

At least 91 records · Page 5Linked to original sources
PubMed1992

Urgent therapy for stroke. Part II. Pilot study of tissue plasminogen activator administered 91-180 minutes from onset.

BACKGROUND AND PURPOSE: Renewed interest in thrombolytic therapy as potential treatment for patients with acute ischemic stroke prompted a dose-escalation safety study of tissue plasminogen activator in patients with very early (less than or equal to 90 minutes; see Part I) neurological symptoms. To test whether this stringent entry window might be safely lengthened, a second study was organized to test tissue plasminogen activator in patients with symptoms of 91-180 minutes' duration before treatment. METHODS: An open-label, dose-escalation design was chosen. Eligible patients had pretreatment head computerized tomographic scanning and treatment begun 91-180 minutes from stroke onset. End points examined included the incidence of symptomatic and asymptomatic intracranial hemorrhage, other bleeding, and clinical outcome at 2 hours, 24 hours, and 3 months after treatment. RESULTS: Twenty patients were treated at three hospitals in 13 months. Three doses were tested: 0.6 mg/kg (n = 8), 0.85 mg/kg (n = 6), and 0.95 mg/kg (n = 6). Two patients, one each at the two highest doses, sustained fatal intracerebral hemorrhages. Three patients (15%) improved by greater than or equal to 4 points on the National Institutes of Health Stroke Scale by 24 hours. CONCLUSIONS: These observations suggest that tissue plasminogen activator treatment of acute ischemic stroke 91-180 minutes from onset in doses of greater than or equal to 0.85 mg/kg is attended by a risk of intracerebral hemorrhage approximating 17% (range 3-44%, 95% confidence interval). The rate of early neurological improvement observed in this study was small but does not exclude an improvement over the natural history. Future study with placebo control subjects and stratification by time to treatment is indicated.

Aged↗
PubMed1990

Seizures in human immunodeficiency virus infection.

Among 630 patients with human immunodeficiency virus infection, 70 patients with new-onset seizures were studied. Generalized seizures occurred in 66 patients (94%): they occurred as the initial seizure in 56 patients (80%) and during follow-up in another 10 patients (14%). Partial seizures (18 patients), status epilepticus (10 patients), and recurrent seizures (38 patients) were also noted. Identified processes included cerebral toxoplasmosis in 11 patients, cerebral lymphoma in 8, metabolic derangement in 8, cryptococcal meningitis in 7, and vascular infarction in 4. In 32 patients (46%) seizures were not associated with identifiable brain lesions and were believed to result from human immunodeficiency virus cerebral infection. Phenytoin treatment was associated with adverse drug reactions in 16 of 62 patients who received it. Our results suggest that the majority of patients with human immunodeficiency virus and seizures do not have secondary focal brain lesions as the cause of the seizures and that human immunodeficiency virus infection alone can, and often does, cause seizures.

Acquired Immunodeficiency Syndrome↗
PubMed1990

Cerebrovascular disease and stroke in women.

There are many special conditions which may predispose women to have a higher risk of stroke. These conditions include pregnancy and the puerperium, exogenous estrogen use, cerebral vasculitis, mitral valve prolapse and migraine. Recognition that certain stroke syndromes are more likely to affect women may aid the clinician in determining the optimal management of cerebrovascular disease and stroke in women.

Cerebrovascular Disorders↗
PubMed1989

Syndrome of cerebellar ataxia and hypogonadotrophic hypogonadism: evidence for pituitary gonadotrophin deficiency.

Familial cerebellar ataxia with hypogonadotrophic hypogonadism is a rare condition. Two affected siblings in a sibship of three were studied and found to have low plasma gonadotrophin levels. No rise in gonadotrophin levels was demonstrable after repeated stimulation with LHRH. The pattern of TSH and prolactin responses to TRH stimulation suggest hypothalamic dysfunction. The results clearly identify the cause of hypogonadism to be due to a defect in production or release of gonadotrophins by the pituitary gland and suggest that hypogonadism is part of a greater endocrine disturbance involving both the hypothalamus and pituitary.

Adolescent↗
PubMed1989

Syringomyelia with Arnold Chiari I malformation: a report of four cases.

4 cases of syringomyelia with type I Arnold Chiari malformation was seen presenting mainly with dissociated sensory loss, weakness of hands and upper motor neurone signs in the lower limbs. The first patient improved with posterior fossa decompression. The second and fourth patient appeared not to have improved after surgery, and the third case refused operation. One patient showed cord atrophy on myelogram presumably due to a collapse of the syrinx. One of the patients was unusual in that the syrinx extended down to segment T11. Magnetic resonance imaging of the posterior fossa and the cervical cord, to date, is the most useful procedure for diagnosis.

Adult↗
PubMed1983

Monoclonal antibodies to Legionella pneumophila serogroup 1: possible applications in diagnostic tests and epidemiologic studies.

Monoclonal antibodies were produced against two strains of Legionella pneumophila serogroup 1. A panel of nine monoclonal antibodies were selected for their unique specificities observed in indirect fluorescent antibody tests with 130 strains of L. pneumophila serogroup 1. One monoclonal antibody was reactive with an antigen possessed by 128 of 130 strains. Two major subgroups were identified and 13 different antigen patterns were observed among the 130 serogroup 1 strains.

Animals↗
PubMed1983

Intestinal lymphangiectasia--a case report.

Primary intestinal lymphangiectasia is a rare cause of protein-losing enteropathy. We report here our first case, a young girl presenting at the age of ten months at the Department of Paediatrics, Singapore General Hospital with generalised oedema and diagnosed to have intestinal lymphangiectasia proven by intestinal biopsy. The literature on some aspects of the subjects is also reviewed.

Adolescent↗
PubMed1980

Intracellular multiplication of Legionella pneumophila in cultured human embryonic lung fibroblasts.

Cell cultures of normal human embryonic lung fibroblasts were inoculated with two strains of Legionella pneumophila, the etiological agent of Legionnaires disease. Large numbers of intact organisms, including many dividing forms, were seen within fibroblasts by light and electron microscopy. Intracellular multiplication of organisms was demonstrated by the progressive increase in bacterial colony counts from plated extracts of infected fibroblast cultures in which extracellular multiplication had been eliminated by bactericidal concentrations of antibiotics. It is evident that L. pneumophila can thrive in an intracellular environment, and this property may be significant in the pathogenesis of Legionnaires disease.

Bacteria↗
PubMed1979

Soluble antigen extracts used as blocking agents to obtain specificity in serotyping of Streptococcus mutans.

Specific immunofluorescent (IF) conjugates were prepared for Streptococcus mutans serotypes d and g. Serotype specificity was obtained by blocking the cross-reacting antibodies with soluble antigen extracted from cells of the cross-reacting strains. Soluble antigen extracts are particularly useful in obtaining specificity with quantities of conjugates that are too small to be efficiently subjected to adsorption procedures. They also can be used advantageously to block traces of cross-reactivity that frequently remain with conjugates that have been subjected to conventional adsorption procedures. S. mutans isolates from dental plaque samples were identified as belonging to serotypes d or g on the basis of IF staining with conjugates that were made type-specific by blocking the cross-reacting antibodies with appropriate soluble antigen extracts.

Antigens, Bacterial↗
PubMed1978

Improved immunoadsorption procedure with anion-exchange bacterial cell columns.

Bacterial cell columns for immunoadsorption were prepared with Streptococcus cells and triethylaminoethyl cellulose (Cellex-T) matrix material as a model system. Good column flow properties and satisfactory retention of the cells were obtained with ratios as high as 2 ml of packed cells/3 g dry weight of cellulose. Anion-exchange fractionation of whole serum by the Cellex-T was prevented by using 0.25 M NaCl in the developing buffer. Antibodies were adsorbed directly from whole serum and recovered in high yield by desorption at pH 2.3. Pre-exposing bacterial cells to formalin and washing them with acetone was necessary to ensure that they remained on the columns. One strain of Streptococcus salivarius (SS 908) was satisfactorily retained on a column only after cells were labeled with fluorescein isothiocyanate and washed with acetone. The means by which Cellex-T retains bacterial cells appears to be a combination of electronic attraction and physical entrapment.

Chromatography, Ion Exchange↗
PubMed1972

Cytopathogenic test for feline leukemia virus infections.

A mixed culture cytopathogenic effect with the development of multinucleated giant cells in feline leukemia virus-infected cultures after cocultivation with XC cells is described. This cytopathogenic effect has been utilized as a convenient visual marker for the detection and assay of feline leukemia virus in feline and canine embryo fibroblasts as well as in a canine tumor cell line, M-132-1. Comparison of the cytopathogenic reaction in the three cell lines indicates that the reaction is more rapid and pronounced in M-132-1 cells than in the embryo fibroblast cultures.

Alpharetrovirus↗
PubMed1972

Changes in activity of glyoxylate cycle enzymes during myxospore development in Myxococcus xanthus.

Activities of the glyoxylate cycle enzymes isocitrate lyase (EC 4.1.3.1) and malate synthase (EC 4.1.3.2) were assayed in extracts prepared at different stages of myxospore formation in liquid cultures of Myxococcus xanthus. Activities of both enzymes attained peak values during conversion of rods to spheres. Isocitrate lyase activity decreased after reaching its peak value. Malate synthase activity also declined but at a much slower rate. The loss of isocitrate lyase activity could be prevented by the addition of chloramphenicol to cultures early in myxospore formation (during the initial rise in enzyme activity), but not by such addition at later stages of myxospore formation. The increase in glyoxylate cycle enzymes was not observed in a mutant unable to form myxospores in liquid culture under conditions suitable for morphological conversion of the wild type, or in wild-type cells incubated in the absence of an inducer for myxospore formation. It is concluded that the changes in the glyoxylate cycle enzymes represent regulatory phenomena associated with the development of the myxospore.

Amino Acids↗
PubMedDate not supplied

A case report of cutis laxa in one of identical twins.

A 29-year-old man with cutis laxa presented requesting surgery to improve his appearance. The patient had an unaffected identical twin brother which allowed us to compare how he had changed over the years in relation to his sibling and this also provided us with a gold standard for any surgery performed. The patient underwent staged surgery including upper lid blepharoplasties and two facelifts.

Adult↗