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W Wong

Publications and source records attributed to W Wong.

At least 199 records · Page 11Linked to original sources
PubMed1982

Evaluation of the AutoMicrobic system for identification of glucose-nonfermenting gram-negative rods.

With the Enterobacteriaceae Plus Biochemical Card, the AutoMicrobic system (Vitek Systems, Inc., Hazelwood, Mo.) is purported to identify members of the family Enterobacteriaceae and seven species of glucose-nonfermenting gram-negative rods: Pseudomonas aeruginosa, P. fluorescens, P. putida, P. maltophilia, P. cepacia, and Acinetobacter calcoaceticus (saccharolytic and non-saccharolytic). The latter capability was examined in this investigation. Of 410 glucose-nonfermenting rods included in the identification profile, the AutoMicrobic system correctly identified 366 (89.3%). Of 62 glucose-nonfermenting organisms not included in the identification profile, 41 (66%) were correctly reported as "unidentified organism." The usefulness of the AutoMicrobic system-generated identification probability in establishing criteria for acceptance of identification is discussed.

Acinetobacter↗
PubMed1982

A proposed criteria for diagnosis of systemic lupus erythematosus used in Veterans General Hospital.

An eight-point diagnostic criteria for SLE was proposed and evaluated at the Veterans General Hospital (VGH), Taipei. It consists of 8 points and 12 items, 3 points being required for an accurate diagnosis. All of 94 cases of SLE whether they could or could not be diagnosed with the ARA criteria fulfilled 3 or more points of the VGH criteria. None of the 17 cases of rheumatoid arthritis fulfilled 3 or more points of the VGH criteria.

Adolescent↗
PubMed1982

Studies on lymphocyte subpopulations and lymphocyte transformation in response to phytohemagglutinin, pokeweed mitogen, concanavalin A in systemic lupus erythematosus.

Forty-eight cases of systemic lupus erythematosus (SLE) were studied for lymphocyte subpopulations, and 42 cases were studied for lymphocyte response to mitogen stimulation. A decreased percentage of thymus-derived cells (T cells) and an increased percentage of bursa-equivalent derived cells (B cells), null cells (N cells), double labelled cells (D cells) were found in non-treated cases of SLE. There was no significant difference in these lymphocyte subpopulations in the treated cases in comparison with the normal control. There was an inverted linear relationship between T cells and N cells (p less than 0.001). No such relationship was found between B cells and N cells. The lymphocyte transformation in response to phytohemagglutinin (PHA), pokeweed mitogen (PWM) and concanavalin A (Con A) was expressed in three ways: (1) the net count of transformed data, (2) the difference between the square roots of the isotope incorporation in the stimulated and the non-stimulated cultures (Dsq), and (3) the stimulation index (SI). There were significantly decreased lymphocyte transformation in response to PHA, PWM stimulation in both the non-treated and the treated cases of SLE when results were expressed as net count and Dsq. But decreased counts in response to Con A was only found in non-treated cases. In contrast, no significantly lowered response to all three mitogens was found when data were expressed as stimulation index. Simultaneous study of the percentages of T cells, B cells, N cells, and D cells might be helpful in assessing the clinical activity of SLE and monitoring the effect of therapy. In the study of lymphocyte response to mitogen stimulation, Con A response was a more sensitive indicator of disease activity. The stimulation index was not a good method to demonstrate the result of lymphocyte response to mitogen stimulation in cases of SLE.

Concanavalin A↗
PubMed1981

Peptidoglycan loss during hen egg white lysozyme-inorganic salt lysis of Streptococcus mutans.

Streptococcus mutans BHT was grown in Todd-Hewitt dialysate medium containing N-acetyl[(14)C]glucosamine for 6 to 11 generations. After treatment with cold and hot trichloroacetic acid and trypsin, 52 to 65% of the radioactivity remained present in insoluble peptidoglycan-containing residues. Hen egg white lysozyme or mutanolysin treatment of the peptidoglycan residues resulted in the release of 80 and 97%, respectively, of the (14)C label to the supernatant fraction. Hydrochloric acid hydrolysates of such supernatants showed that essentially all of the radioactivity present in insoluble peptidoglycan fractions was present in compounds that comigrated on paper chromatography with glucosamine ( approximately 60%) or muramic acid ( approximately 30%). Treatment of whole cells with low and high concentrations of lysozyme alone resulted in losses of 45 and 70% of the insoluble peptidoglycan, respectively, yet release of deoxyribonucleic acid from cells was not detected. Sequential addition of appropriate concentrations of selected inorganic salts after lysozyme treatment did result in the liberation of deoxyribonucleic acid. Deoxyribonucleic acid release was correlated with a further release of peptidoglycan from the insoluble fraction. However, the total amount of peptidoglycan lost effected by the low concentration of lysozyme and NaSCN (lysis) was significantly less than the amount of peptidoglycan hydrolyzed by high concentrations of lysozyme alone (no lysis), suggesting that the overall amount of peptidoglycan lost did not correlate well with cellular lysis. The total amount of insoluble peptidoglycan lost at the highest salt concentrations tested was found to be greater than could be accounted for by lysozyme-sensitive linkages of the peptidoglycan, possibly implicating autolysins. The results obtained suggested that hydrolysis of peptidoglycan bonds in topologically localized, but strategically important, sites was a more significant factor in the sequence that results in loss of cellular integrity (lysis).

Anions↗
PubMed1981

Clinical laboratory evaluation of the Auto-Microbic system for rapid identification of Enterobacteriaceae.

The capability of the Auto-Microbic system (Vitek Systems, Inc., Hazelwood, Mo.) has been expanded to identify members of the family Enterobacteriaceae with the use of a sealed, disposable accessory card (the Enterobacteriaceae Biochemical Card) containing 26 biochemical tests. To judge the accuracy of the AutoMicrobic system's identification in a hospital laboratory, 933 Enterobacteriaceae isolates were studied. The AutoMicrobic system provided the correct identification for 905 of the isolates (97%). For Enterobacteriaceae excluding Escherichia coli (533 isolates not E. coli), 506 isolates were correctly identified (94.9%). The AutoMicrobic system integrates well into the clinical microbiology laboratory, providing a simple, accurate, and efficient automated system for the rapid identification of Enterobacteriaceae.

Bacteriological Techniques↗
PubMed1981

Association of infectious mononucleosis with nephrotic syndrome.

A patient had infectious mononucleosis (IM) associated with transient nephrotic syndrome (NS). A kidney biopsy sample studied by light and electron microscopy demonstrated minimal glomerular lesions. Immunofluorescent studies revealed mainly granular mesangial deposits of IgM, and to a lesser extent, deposits of IgG and of C4 and C3. No Epstein-Barr virus-related antigen could be detected in the kidney. This, and three other cases reported in the literature, suggest a causal relationship between IM and NS.

Adolescent↗
PubMed1980

Serological studies on systemic lupus erythematosus.

Serum samples from 73 cases of Systemic lupus erythematosus (SLE) were studied for proteins, immunoglobulins, complement components and anti-nuclear antibodies. In fresh cases of SLE, low serum albumin, high alpha-1, alpha-2, and gamma-globulins were found. Marked elevation of serum levels of IgG was found at the time of diagnosis, but this returned to normal after regular treatment. Over 71% of SLE had serum levels of C3 and C4 lower than normal (mean - 2SD). The more severe the disease, the lower the serum levels of these two components of complement. Fluorescent anti-nuclear antibody (FANA) was found in 98.6% of the cases studied. Most (85.1%) cases and anti-double stranded deoxyribonucleic acid (anti-ds DNA) antibody levels higher than normal control (mean + 2 SD). We may conclude that FANA, C3, C4 and anti-ds DNA anatibody are immunological parameters sensitive in the early diagnosis of SLE. FANA is the most sensitive, and can be used as a screening test in SLE. The serum C3 and C4 levels correlate well with the severity of the disease.

Adolescent↗
PubMed1980

[The value of serum salicylate determination in patients with rheumatoid arthritis (author's transl)].

Thirty-one patients with rheumatoid arthritis in the Veterans General Hospital from July 1978 to June 1979 were treated with acetylsalicylic acid. The serum salicylate level was determined twice a week. The dose of acetylsalicylic acid was adjusted to keep the serum salicylate level around 15-30 mg%. All patients were started with an initial dose of 65 mg/kg/day. The serum salicylate levels at the 4th day varied greatly from 5.6 to 29.5 mg%. Tinnitus was noted in 24 patients. It occurred when the serum salicylate level reached 28.41 +/- 1.84 mg%. Abnormal liver function was noted in 19.35% (6/31) patients during treatment. It returned to normal after withdrawal of acetylsalicylic acid in 3 cases, after decrease of the dosage in 2 cases and on the same dosage in 1 case. Patients with positive FANA and RF were more prone to develop abnormal liver function during treatment. Monitoring of serum salicylate level may decrease the incidence of hepatic toxicity and maintain the dosage of acetylsalicylic acid in optimal range.

Adult↗
PubMed1979

Cell envelope of Neisseria gonorrhoeae CS7: peptidoglycan protein complex.

Treatment of cells grown to exponential phase with 4% sodium dodecyl sulfate for 3 h at 100 degrees C resulted in solubilization of all cellular components except for peptidoglycan. In most strains, cells cultured in liquid gonococcal broth at pH 7.2 yielded a peptidoglycan composed primarily of N-acetylmuramic acid N-acetylglucosamine, alanine, glutamic acid, and diaminopimelic acid in a molar ratio of 1:1:2:1:1. The peptidoglycan in these cells accounted for 1 to 2% (dry weight) of the cells. However, in cells cultured at pH 6.0, the dry weight of peptidoglycan increased to 4 to 13%. Preliminary investigations indicated that the apparent increase in weight is strain dependent and is due in part to associated protein(s). Neisseria gonorrhoeae strain CS7 had elevated amounts of protein associated with the peptidoglycan regardless of growth pH. The peptidoglycan-protein complex could not be dissociated by additional extraction with sodium dodecyl sulfate, 10 M LiCl2, or ethylenediaminetetraacetate or by 7.5% polyacrylamide gel electrophoresis. The complex could be degraded by lysozyme, trypsin, chymotrypsin, Pronase B, and Chalaropsis sp. muramidase.

Amino Acids↗
PubMed1979

Local xenogeneic graft-vs-host reaction: a practical assessment of T cell function among cancer patients.

The local xenogeneic graft-vs-host reaction (XGVHR) was used as a practical bioassay to assess T lymphocyte function and immunocompetence among cancer patients. Positive XGVHR was found in 99.5% of normal donors, 70% of cancer patients with early stage disease, and 30% of cancer patients with metastatic disease (p less than 0.001). A minimum of 4.5 x 10(6) immunocompetent T lymphocytes are necessary in order to elicit a positive XGVHR. Negative reactions among cancer patients are characterized by the lack of edema fluid accumulation and the appearance of the most basophils at the test site. This suggests that insufficient amounts of lymphokines are being released by the incompetent T lymphocytes, whereas the host is capable of mounting a rejection reaction as evidenced by the appearance of the basophils. Preliminary evidence suggests that the immunologic defect detected by the XGVHR cannot be corrected by monocyte depletion. The identification of putative suppressor T cell subsets may bear immunotherapeutic implications in the future.

Animals↗
PubMed1978

Regulation of bacterial cell walls: correlation between autolytic activity and cell wall turnover in Staphylococcus aureus.

Cell wall turnover was examined in parent and mutant strains of Staphylococcus aureus. Peptidoglycan and teichoic acid were observed to undergo turnover in the wild-type strain during exponential growth; however, the rate of turnover did not decrease when the growth rate slowed, as the culture entered stationary phase. Isolated native cell walls and crude soluble autolytic enzyme were prepared from cells harvested during exponential and postexponential phases of growth. Native cell walls from both phases of growth autolyzed in buffer at identical rates; similarily, crude soluble enzyme from both preparations degraded radioactive cell walls at the same rate. Therefore, the activity of the autolysin in both exponential and postexponential cells was similar. The autolysis of whole cells of a mutant tar-1 was enhanced by 1.0 M NaCl. When 1.0 M NaCl was present under growing conditions, the rate of cell wall turnover was greatly increased. The presence of chloramphenicol, which inhibits whole-cell autolysis, also inhibited turnover. Analysis of the cell wall material recovered from spent medium revealed products consistent with the known mode of action of the endogenous autolysin. It is concluded that cell wall turnover in S. aureus is independent of the stage of culture growth but is dependent instead on the activity of the autolysin.

Bacteriolysis↗
PubMed1976

Isolation and characterization of a mutant of Staphylococcus aureus deficient in autolytic activity.

A mutant of Staphylococcus aureus H (RUS3) uas isolated after mutagenesis with N-methyl-N'-nitro-N-nitrosoguanidine. The rate of autolysis of whole cells and isolated cell walls of RUS3 was less than 10% of the parent strain. In addition, the ability of the crude soluble enzyme isolated from RUS3 to degrade cell walls was negligible compared with the parent strain. The cell wall composition and the generation time of RUS3 were comparable to the parent strain. Unlike S. aureus H, RUS3 grew in clumps and did not undergo cell wall turnover. Both strains exhibited identical kinetics of killing by penicillin G. This may indicate that autolytic enzymes play a role in cell wall turnover and cell separation, but in S. aureus most of the autolytic activity is unrelated to the lethal effect of cell wall antibiotics.

Amidohydrolases↗