Search PubMed⌕ Search

Biomedical subjects

W Wong

Publications and source records attributed to W Wong.

At least 217 records · Page 12Linked to original sources
PubMed1975

Radiologic detection and prostatic carcinoma by double contrast retrograde urethrocystography.

A method of radiologic visualization of the male urethra especially for detecting prostatic carcinoma is reported. This method is called double contrast retrograde urethrocystography and is similar to that of Flocks in combining air cystography and retrograde urethrography but it differs in the manner of making the exposure. In our method the exposure is made with the patient in an exaggerated Trendelenburgs position to allow the contrast medium injected into the bladder to accumulate at the dome. Thus, in the urethrocystogram obtained by this method, the bladder neck and the prostatic urethra immediately adjacent to it are always clearly visualized unlike that obtained by conventional retrograde urethrography, evacuation cystourethrography and sometimes even the method of Flocks, in which these regions are prone to be covered and masked by the contrast medium injected and accumulated in the bladder. Therefore, with our method the radiological detection and differentiation of the malignant lesion involving these regions are more accurate and definite. From our clinical experiences the mode of compression and displacement caused by benign prostatic hypertrophy is continuous and regular, while that caused by prostatic carcinoma is interrupted, irregular and with moth-eaten and granular defects. Four cases are reported.

Aged↗
PubMed1975

Isotope Fractionation in Photosynthetic Bacteria during Carbon Dioxide Assimilation.

The delta (PDB) (13)C values have been determined for the cellular constituents and metabolic intermediates of autotrophically grown Chromatium vinosum. The isotopic composition of the HCO(3) (-) in the medium and the carbon isotopic composition of the bacterial cells change with the growth of the culture. The delta (PDB) (13)C value of the HCO(3) (-) in the media changes from an initial value of -6.6 per thousand to +8.1 per thousand after 10 days of bacterial growth and the delta (PDB) (13)C value of the bacterial cells change from -37.5 per thousand to -29.2 per thousand in the same period. The amount of carbon isotope fractionation during the synthesis of hexoses by the photoassimilation of CO(2) has a range of -15.5 per thousand at time zero to -22.0 per thousand after 10 days. This range of fractionation compares to the range of carbon isotope fractionation for the synthesis of sugars from CO(2) by ribulose 1,5-diphosphate carboxylase and the Calvin cycle.The amount of carbon isotope fractionation during the synthesis of aspartic acid from CO(2) is -24.9 per thousand at time zero and -15.0 per thousand after 10 days of bacterial growth. This amount of fractionation is in the range of carbon isotope fractionation for the synthesis of C(4) amino acids by a double carboxylation through ribulose 1,5-diphosphate and phosphoenolpyruvate carboxylase.

Journal Article↗
PubMed1974

Autolysis in Staphylococcus aureus: preferential release of old cell walls.

The kinetics of release of old versus new cell wall in two strains of Staphylococcus aureus were studied during autolysis. In both strains the autolytic enzyme is an amidase. Cells were double labeled with (3)H and (14)C, and the distribution of radioactivity in the cell walls was monitored during autolysis. In all cases the rate of release of steady-state lable from peptidoglycan was significantly higher than that of pulse label. Identical results were obtained with whole cells or isolated cell walls. The results suggest that in S. aureus the old cell wall is preferentially released during autolysis.

Amidohydrolases↗
PubMed1974

Regulation of bacterial cell walls: turnover of cell wall in Staphylococcus aureus.

The cell wall of Staphylococcus aureus was shown to undergo turnover during exponential growth. The rate of turnover, about 15% per generation, was identical for both cell wall polymers, peptidoglycan and teichoic acid. Both the old and newly synthesized wall material appeared to undergo turnover at similar rates. The rate of turnover followed first-order kinetics until more than 90% of the original wall was lost. Cell wall turnover was completely blocked under conditions of unbalanced synthesis known to inhibit cellular autolysis, e.g., addition of chloramphenicol. Cell wall turnover was shown to occur in a number of different strains of S. aureus and appears to be widely distributed in this species.

Bacterial Proteins↗
PubMedDate not supplied

Pneumocystis carinii pneumonia in an immunocompetent infant with congenital cytomegalovirus infection.

The case of a term infant with congenital cytomegalovirus (CMV) infection who developed Pneumocystis carinii pneumonia (PCP) at 4 months of age is reported. Our patient suffered from severe malnutrition and zinc deficiency secondary to necrotizing enterocolitis since the age of 2 months. There was no evidence of human immunodeficiency virus infection. Qualitative and quantitative in vitro leukocyte functions were also normal. This case highlights the fact that PCP can occur in apparently immunocompetent term infants. Malnourished infants with zinc deficiency or congenital CMV infection are at increased risk of developing PCP.

Bronchoalveolar Lavage Fluid↗
PubMedDate not supplied

Unsuspected and unrelated pathology noted on limited computed tomographic scans of the paranasal sinuses and temporal bone.

Modern imaging includes many studies performed to examine limited fields of view (i.e., paranasal sinus studies). These studies are frequently retrospectively coned to the limited field of view and are often examined only at one window and level setting. However, classic radiology teaching demands that all irradiated structures be examined by a qualified physician; for examples, on an intravenous pyelogram the examiner should look at not only the kidneys, ureters, and bladder, but also the bones, soft tissues, and gas patterns. This article illustrates unsuspected intracranial pathology noted on computed tomographic examinations of the paranasal sinuses and temporal bones.

Adult↗
PubMedDate not supplied

Drug use behaviors among Asian drug users in San Francisco.

Due to a pervasive bias toward Asian Americans, such as tendency to view Asian Americans as model minorities, drug use behaviors among them are often ignored by health professionals, researchers, and community members, including Asian community members. This study identified patterns of drug use behaviors in relation to cultural factors among Asian drug users in San Francisco, CA. A sample of 92 Asian drug users (35 Chinese, 31 Filipino, 26 Vietnamese) who were not currently enrolled in drug treatment programs were recruited through targeted sampling methods and interviewed using a questionnaire with open-ended questions. The study evaluated responses of the participants and used content analyses. This study clearly revealed that the patterns of drug use among Asian drug users are unique to their ethnicity, gender, immigrant status, and age groups. Also, Asian drug users share cultural constructs related to drug use such as fear of addiction and injecting drugs, and stigma attached to drug users in the community. Therefore, drug abuse prevention programs should address both common factors among Asian drug users, as well as unique factors in specific target groups (e.g., ethnic groups, Asian immigrants, Asian women, refugees, and adolescents).

Adult↗
PubMedDate not supplied

Optical response of the cultured bovine lens; testing opaque or partially transparent semi-solid/solid common consumer hygiene products.

This study determines the relative ocular lens irritancy of 16 common partially transparent or non-transparent consumer hygiene products. The irritancy was found by measuring the changes in the sharpness of focus [referred to as the back vertex distance (BVD) variability] of the cultured bovine lens using a scanning laser In Vitro Assay System. This method consists of a laser beam that scans across the lens, and a computer, which then analyses the average focal length (mm), the BVD variability (mm), and the intensity of the beam transmitted. Lenses were exposed to the 16 hygiene products and the lens' focusing ability was monitored over 192 h. The products are semi-solids or solids (e.g. gels, lotions, shampoos). They are categorized into six groups: shampoos, body washes, lotions, toothpastes, deodorant, and anti-perspirant. Damage (measured by > 1 mm BVD variability) occurred slower for the shampoos, especially in the case of baby shampoo. The results indicate that shampoos exhibit the lowest level of ocular lens toxicity (irritability) while the deodorant is the most damaging.

Animals↗
PubMedDate not supplied

Anti-cyclic citrullinated peptide: diagnostic and prognostic values in juvenile idiopathic arthritis and rheumatoid arthritis in a Chinese population.

OBJECTIVE: The incidence and clinical significance of anti-cyclic citrullinated peptide (CCP) antibodies in a cohort of Chinese patients with juvenile idiopathic arthritis (JIA) and adults with rheumatoid arthritis (RA) were studied. METHODS: Anti-CCP antibodies were determined by enzyme-linked immunosorbent assay (ELISA) in 59 patients with JIA, 129 adult RA patients, 48 children with diseases other than JIA, 68 adult patients with rheumatic diseases other than RA, and 60 normal adults. Associations between anti-CCP antibodies and clinical and laboratory parameters were determined by Fisher's exact test. RESULTS: Six of 59 (10.2%) patients with JIA and 71 of 129 (55%) patients with RA were positive for anti-CCP. Four of five RF-positive JIA patients and two of 54 RF-negative JIA patients were positive (p<0.001). One paediatric patient with allergy (0.9%) and two adult patients with rheumatic diseases other than RA (2.3%) were positive. All healthy controls were negative for anti-CCP. The specificity was 99.1% for JIA and 98.4% for RA. The sensitivity was 10.2% for JIA and 55% for RA. Positive predictive values were 85.7% for JIA and 97.3% for RA and negative predictive values were 66.9% for JIA and 68.5% for RA. CONCLUSION: The anti-CCP antibody assay is a valuable tool for the diagnosis of RA and a subset of JIA in Chinese patients. It could be a useful predictive test for joint erosion in JIA of the polyarticular RF-positive subset and may be influential in the choice of the best therapeutic strategy in patients with recent-onset arthritis.

Adolescent↗