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Biomedical subjects

W L Wang

Publications and source records attributed to W L Wang.

At least 55 records · Page 3Linked to original sources
PubMed1991

Serum high-density lipoproteins in the crab, Cancer antennarius--III. Density-gradient profiles and lipid composition of subclasses.

1. Prestaining the serum total lipoprotein (LP) fraction and density-gradient ultracentrifugation revealed up to five LPs, all in the high-density class (HDL; 1.187 greater than d greater than 1.080 g/ml). These are group-designated as HDL1, HDL2 and HDL3, lowest to highest buoyant density, respectively. The number and precise density of the LPs varied with individual crab and were not gender specific. 2. The percentage of total mass due to triacylglycerides was progressively higher from HDL1 and HDL3, whereas that of phospholipids, cholesterol and combined fat was progressively lower. The percentage mass of combined fat was higher in females than males. 3. As in hemolymph, the LP of eggs was entirely HDL; instances of each HDL subclass were seen, but HDL3 was predominant. Compared with serum HDL, egg HDL was strikingly low in triacyglyceride mass and relatively high in protein. 4. Hemolymph HDL titers of individual females varied independently with egg size through most of the year, but was positively correlated with the egg size in October to December when 2-3-fold increases in HDL titer occur in the female population.

Animals↗
PubMed1991

Ferritin in astrocytomas.

Ferritin in 119 astrocytoma cases was studied by immunocytochemical PAP and immunogold silver staining (IGSS) methods. In 57% of the cases, ferritin was found in the cytoplasm of the tumor cells. The higher the differentiation of the tumor cells, the less ferritin they contained. Contrary to the reaction of glial fibrillary acidic protein (GFAP), the positive rate of ferritin in various types and grades of astrocytomas was inversely proportional to their degree of differentiation. Electron microscopic observation in 30 cases showed ferritin in the cell sap, cytocavity network, endoplasmic reticulum, Golgi apparatus and also in lysosomes. Some of the cases had extraordinary high level of ferritin in their blood serum.

Astrocytoma↗
PubMed1991

[Studies on the chemical constituents of Melia azedarach L].

Melianoninol (I), melianol (II), melianone (III), meliandiol (IV), vanillin (V) and vanillic acid (VI) were isolated from the fruits of Melia azedarach L.. The structure of melianoninol, a new compound, was elucidated by IR, MS, 1H NMR, 13CNMR and other spectral evidences. The new compound possesses some anti-feeding properties against the imported cabbage worm (Pieris rarae L.).

Acrolein↗
PubMed1991

Comprehensive assessment of long-term postoperative continence in pediatric imperforate anus. Clinical, manometric and contrast studies.

109 patients with imperforate anus were followed up postoperatively for 5 to 28 years. Postoperative continence was evaluated by anorectal manometry, barium enema and clinical symptoms. A comprehensive assessment system, combining the clinical and objective systems was designed which can reflect postoperative anal continence function completely and objectively. It is useful for determining the causes of incontinence and its treatment.

Adolescent↗
PubMed1991

[Significance of assaying serum bone GLA protein level in patients with hyperthyroidism].

The serum BGP level was assayed in patients with hyperthyroidism (untreated and remittent cases). The mean serum BGP concentration was 8.7 +/- 2.5 ng/ml in 54 patients with untreated hyperthyroidism, which was significantly higher than normal range (4.8 +/- 1.3 ng/ml P less than 0.01). Serum BGP had a significant positive correlation with the concentration of T3 and T4, while serum AKP had no correlation with circulating thyroid hormone levels. In the patients with hyperthyroidism, serum T3 and T4 decreased significantly after the first month of methimazole treatment, and fluctuated within the normal range since then. Serum BGP did not show significant change during the first six months of treatment, although they were eventually reduced significantly at the end of six months. These results suggest that serum BGP measurement is a valuable marker of bone metabolism alteration during hyperthyroidism.

Adult↗
PubMed1989

Evidence that Y-organs of the crab Cancer antennarius secrete 3-dehydroecdysone.

Y-organs are paired glands in crustaceans that secrete a class of steroid hormones (ecdysteroids) that regulate growth, molting and development. The glandular secretion has been assumed to be solely the ecdysteroid, ecdysone, a polyhydroxylated derivative of cholesterol. We previously reported that Y-organs of a crab (Cancer antennarius) additionally secreted an ecdysteroid that is less polar than ecdysone. Evidence is presented here that the other secretion product is 3-dehydroecdysone (3-dhE). The compound co-chromatographed with authentic 3-dhE in both normal-phase, and reversed-phase, high-performance liquid chromatography. Mass spectrometry of the ecdysteroid gave results consistent with its identity as 3-dhE. The putative 3-dhE was radiolabeled by injecting crabs with [3H]cholesterol and then incubating the Y-organs. The putative [3H]3-dhE secretion was then subjected to chemical reduction. The reaction yielded labeled products that co-chromatographed with authentic ecdysone and 3-epiecdysone. Results of other experiments gave the following results: (1) Putative 3-dhE was not altered (chromatographic criteria) by incubations with snail hydrolases. (2) Putative [3H]3-dhE, added to incubations of Y-organ halves or homogenates, was not significantly converted to ecdysone; also, no conversion was evident after incubation in medium alone in which the hemolymph serum supplement was raised to 50% of the volume. (3) [3H]Ecdysone was not converted to putative 3-dhE in vitro by Y-organ halves or homogenates.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1989

Staining bacterial flagella easily.

A wet-mount technique for staining bacterial flagella is highly successful when a stable stain and regular slides and cover slips are used. Although not producing a permanent mount, the technique is simple for routine use when the number and arrangement of flagella are critical in identifying species of motile bacteria.

Alcaligenes↗
PubMed1989

[Surface charged liposomes as drug carriers and in vivo tests of mice infected with toxoplasma].

The surface charge is one of the most important properties of liposomes. In this paper surface potential of liposomes was measured by fluorimetry using 1.8-ANS as a probe and by microelectrophoresis. The encapsulation efficiency and leakage rate of ionic drugs were influenced by the surface charge of liposomes. Higher encapsulation efficiency and lower leakage rate were resulted if the surface charge of liposomes was opposite to the ionic charge of encapsulated drug. Mice infected with toxoplasma were used as a model. In in vivo test, liposome-drug was compared with the free drug. The average survival days of groups of liposome-drugs were much longer than that of the group of free drugs. Mouse infected with toxoplasma is a simple, convenient and accurate model for measuring the biological activation of liposome-drugs.

Animals↗
PubMed1988

Evaluation of modified trypticase soy broth versus supplemented peptone broth in the detection of bacteremia and fungemia.

In vitro, 1.2% gelatin counteracts the inhibition of growth of bacterial species by sodium polyanetholsulfonate in blood culture media. Additionally, 1% yeast extract has been used to promote bacterial growth. We compared the performance of supplemented peptone broth and Trypticase soy broth, both of which contained sodium polyanetholsulfonate, gelatin and yeast extract. Trypticase soy broth with gelatin and yeast extract inhibited (p less than 0.001) and delayed growth, especially of gram-positive (p less than 0.01) and gram-negative (p less than 0.005) anaerobic bacteria. Although the recovery of organisms usually inhibited by sodium polyanetholsulfonate was similar in supplemented peptone and Trypticase soy broths, supplemented peptone broth clearly was superior in the recovery of other organisms commonly found in blood cultures.

Bacteria↗
PubMed1988

Persistent Campylobacter jejuni infections in patients infected with the human immunodeficiency virus (HIV).

We identified Campylobacter jejuni infections in four patients infected with the human immunodeficiency virus (HIV); three had persistent and severe C. jejuni infections. Multiple isolates obtained from each patient had the same biochemical and serotypic characteristics, indicating recurrent infection rather than reinfection with unrelated strains. Serum antibody responses to C. jejuni group antigens by enzyme-linked immunosorbent assay were markedly impaired in the three patients with persistent infection compared with forty-two immunocompetent C. jejuni-infected controls and with the HIV-infected patient who readily cleared the organism. One patient was bacteremic; his blood isolate was killed by normal serum but was resistant to his own serum, whereas a simultaneous stool isolate of a different serotype was sensitive. Failure of two patients to eradicate the organism and long-term administration of erythromycin therapy led to the in-vivo development of resistance to this antibiotic, which is most frequently used to treat C. jejuni infections.

Acquired Immunodeficiency Syndrome↗
PubMed1987

Controlled evaluation of trypticase soy broth with and without gelatin and yeast extract in the detection of bacteremia and fungemia.

The addition of gelatin to blood culture media has been suggested to prevent the inhibition of Neisseria meningitidis, Neisseria gonorrhoeae, Gardnerella vaginalis, and Peptostreptococcus anaerobius that is caused by sodium polyanetholsulfonate. To determine the effect of such supplementation on the overall yield of microorganisms, we compared the yield and speed of detection of clinically important microorganisms from 5422 paired 10-ml samples of blood cultured in Trypticase soy broth (TSB) containing 0.03% sodium polyanetholesulfonate (SPS) and TSB/SPS containing 1.2% gelatin and 1.0% yeast extract (mTSB). The atmosphere of incubation (open venting unit) and ratio of blood to broth (1:5) were the same for both samples. Only cultures with adequate blood sample (greater than or equal to 80% of stated volume) were compared statistically. Addition of gelatin and yeast extract resulted in inhibited growth of Enterobacteriaceae (p less than 0.001), Pseudomonas aeruginosa (p less than 0.01), fungi (p less than 0.05), and the overall set of microorganisms encountered (p less than 0.001). It delayed growth of Enterobacteriaceae (p less than 0.001) but reduced the time to recover staphylococci (p less than 0.02). Of 12 isolates of species usually inhibited by SPS, seven grew only with the addition of gelatin and yeast extract, none grew only without supplementation, and five grew in both media. Although gelatin and yeast extract may improve the yield of some specific bacteria, the routine use of these additives cannot be recommended for all blood culture media.

Adult↗
PubMed1987

Pathogenesis of Campylobacter fetus infections: serum resistance associated with high-molecular-weight surface proteins.

Campylobacter fetus subspecies fetus causes both systemic and diarrheal illnesses. We studied 38 strains of C. fetus isolated from 34 patients; underlying illness was present in eight (89%) of nine patients with only systemic isolates compared with three (20%) of 15 patients with only fecal isolates (P = .002). In a standardized assay of susceptibility to normal human serum, 27 (71%) strains were resistant, six (16%) had intermediate susceptibility, and five (13%) were serum sensitive. Major protein bands migrating at 100 kDa or 125 kDa on polyacrylamide gels were present in all of the 25 serum-resistant strains tested but in only four of seven serum-sensitive isolates of C. fetus from humans and animals (P = .007). The presence of these bands was associated with type A lipopolysaccharide. A low-passaged strain, 82-40, was serum resistant and contained the 100-kDa protein; however, a spontaneous mutant of this strain lacked this band and was serum sensitive. The 100-kDa and 125-kDa proteins of three strains of C. fetus were antigenically cross reactive or identical and were exposed on the surface of the C. fetus cell. Serum resistance is inherent to most C. fetus isolates from humans and is associated with the presence of cross-reactive surface proteins.

Animals↗
PubMed1987

Erythromycin-resistant Campylobacter infections in Thailand.

Erythromycin therapy was compared with no treatment in a prospective trial of acute diarrheal disease among 100 infants in an orphanage in Bangkok. Within 24 h of the onset of diarrhea, 50 children received erythromycin ethylsuccinate (40 mg/kg per day) in four divided doses for 5 days. Campylobacter jejuni isolated from 31, Campylobacter coli isolated from 21, and Shigella spp. isolated from 21 of 100 children were the most commonly recognized pathogens; use of a sensitive, nonselective method substantially increased Campylobacter isolation. Treatment with erythromycin had no effect on the duration of diarrhea caused by Campylobacter spp., Shigella spp., or other agents; 37% of the treatment group and 35% of the control group had diarrhea for 1 week. Of 23 Campylobacter strains isolated from the treatment group before treatment, 15 (65%) were resistant (MIC, greater than or equal to 8 micrograms/ml) to erythromycin. Among orphanage-acquired strains, 53% of 43 C. jejuni strains and 91% of 23 C. coli strains were resistant to erythromycin compared with 11% of 114 C. jejuni strains and 46% of 35 C. coli strains that were community acquired. Erythromycin resistance is common among Campylobacter strains in Bangkok, especially in an institutional setting, which may account for the lack of efficacy of erythromycin for treatment of acute diarrheal illnesses.

Campylobacter↗
PubMed1987

Controlled evaluation of modified radiometric blood culture medium supplemented with gelatin for detection of bacteremia and fungemia.

Although the addition of 1.2% gelatin to broth blood culture media containing sodium polyanetholesulfonate has been shown to enhance detection of certain bacteria, including Neisseria meningitidis, N. gonorrhoeae, Peptostreptococcus anaerobius, and Gardnerella vaginalis, the effect of such supplementation on the detection of other microorganisms causing bacteremia and fungemia is not known. Therefore, we studied BACTEC 6B medium with and without gelatin in 6,833 paired comparisons to examine the effects of supplementation on both the yield and the speed of detection of sepsis. More aerobic and facultative bacteria grew in the 6B than in the 6B-gelatin medium (P less than 0.001), especially staphylococci (P less than 0.01), Escherichia coli (P less than 0.01), other members of the family Enterobacteriaceae (P less than 0.05), and Acinetobacter spp. (P less than 0.05). When microorganisms grew in both bottles, they did so earlier in 6B than in 6B-gelatin (P less than 0.001). We conclude that the 6B medium in its present formulation is superior to 6B medium supplemented with 1.2% gelatin.

Bacteria↗
PubMed1986

Inactivation of Campylobacter jejuni by chlorine and monochloramine.

Campylobacter jejuni and closely related organisms are important bacterial causes of acute diarrheal illness in the United States. Both endemic and epidemic infections have been associated with consuming untreated or improperly treated surface water. We compared susceptibility of three C. jejuni strains and Escherichia coli ATCC 11229 with standard procedures used to disinfect water. Inactivation of bacterial preparations with 0.1 mg of chlorine and 1.0 mg of monochloramine per liter was determined at pH 6 and 8 and at 4 and 25 degrees C. Under virtually every condition tested, each of the three C. jejuni strains was more susceptible than the E. coli control strain, with greater than 99% inactivation after 15 min of contact with 1.0 mg of monochloramine per liter or 5 min of contact with 0.1 mg of free chlorine per liter. Results of experiments in which an antibiotic-containing medium was used suggest that a high proportion of the remaining cells were injured. An animal-passaged C. jejuni strain was as susceptible to chlorine disinfection as were laboratory-passaged strains. These results suggest that disinfection procedures commonly used for treatment of drinking water to remove coliform bacteria are adequate to eliminate C. jejuni and further correlate with the absence of outbreaks associated with properly treated water.

Animals↗
PubMed1986

Serogroup specificity of Legionella pneumophila is related to lipopolysaccharide characteristics.

We studied the lipopolysaccharide (LPS) of Legionella pneumophila and six other Legionella species to determine whether strain differences were apparent. The LPS was purified by a cold ethanol extraction procedure, and total carbohydrates represented 10 to 20% of LPS weight. 2-keto-3-deoxyoctonate represented 1 to 13% of the total carbohydrate present in the LPS. By sodium dodecyl sulfate-polyacrylamide gel electrophoresis, all strains except L. dumoffi showed smooth-type LPS with multiple high-molecular-weight complexes. Proteinase K-treated, whole-cell lysates showed profiles similar to those of purified LPS. Each serogroup of L. pneumophila and each Legionella species had a distinct sodium dodecyl sulfate-polyacrylamide gel electrophoresis profile. L. pneumophila lipid A is antigenically related to the lipid A of Enterobacteriaceae. In immunoblot assays with the LPS of L. pneumophila serogroups 1 to 6 as antigens, serogroup-specific immune monkey sera recognized homologous purified LPS, but not the LPS of the five heterologous serogroups. These studies indicate that LPS composition may be a determinant of serogroup specificity as defined by the immunofluorescence-based serogrouping schema for L. pneumophila and other Legionella species.

Antigens, Bacterial↗
PubMed1986

Controlled evaluation of the agar-slide and radiometric blood culture systems for the detection of bacteremia and fungemia.

A commercially available agar-slide blood culture bottle (Septi-Chek; Roche Diagnostics, Div. Hoffman-La Roche, Inc., Nutley, N.J.) was compared with the radiometric blood culture system (BACTEC; Johnston Laboratories, Inc., Towson, Md.) in 8,544 paired blood cultures from adult patients. The systems were inoculated with equal volumes (10 ml) of blood. Overall, there was no statistically significant difference between the two systems in the recovery of clinically important microorganisms, but significantly more members of the family Enterobacteriaceae other than Escherichia coli were detected by the agar-slide system (P less than 0.005). The agar-slide system detected more fungi, and the BACTEC detected more anaerobic bacteria; however, small numbers of recovered organisms precluded statistical significance. When microorganisms grew in both systems, their presence was detected one or more days earlier in the BACTEC (P less than 0.001). More contaminants grew in the agar-slide system (P less than 0.001). Both systems performed well, and either system should provide high yield and prompt detection of positive blood cultures in patients with bacteremia and fungemia if used in an optimal way as recommended by the respective manufacturers.

Bacteria↗