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Biomedical subjects

W C Wang

Publications and source records attributed to W C Wang.

At least 181 records · Page 10Linked to original sources
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↗
PubMed1977

Elevated serum ferritin in children with malignancies.

Serum ferritin (SF) is elevated in adults with malignancies, chronic inflammatory disease, liver disease and iron overload. The purpose of this study was to determine whether the concentration of SF in children with a variety of malignancies correlated with the activity of their disease. Patients with acute lymphoblastic leukaemia (ALL) at initial diagnosis (n = 11) and relapse (n = 15) had a mean SF of 238 and 338 ng/ml, respectively, compared to the normal mean of 31 ng/ml and range of 7 to 140 ng/ml in children. In 30 patients with ALL in remission the mean SF was 109 ng/ml, less than the values in patients with active disease and greater than the normal mean (P less than 0.001). The concentration of SF was also increased in a group of 77 patients with a variety of solid tumors. The 28 cases with active disease had a mean SF of 242 ng/ml, significantly higher (P less than 0.001) that the value of 84 ng/ml in 49 patients with no evidence of residual tumor. The differences in SF concentration did reflect the activity of disease in the groups as a whole but it remains uncertain whether the assay will prove useful in following the response to treatment of patients with certain types of tumor.

Adolescent↗
PubMed1976

Differentiation of transient erythroblastopenia of childhood from congenital hypoplastic anemia.

Erythrocyte properties of patients with congenital hypoplastic anemia were compared to those of patients with transient erythroblastopenia of childhood. The MCV was less than 85 in all nine TEC patients studied and greater than 90 in all 11 CHA patients. Hemoglobin F concentration was elevated beyond the normal level for age in eight CHA patients and almost always normal in TEC. The i antigen score was more likely to be elevated in CHA than in TEC. The activities of transaminase, aldolase, phosphofructokinase, and glutathione peroxidase were higher in CHA than in TEC (p less than 0.001). Some abnormal properties (namely, MCV and hemoglobi n F concentration) of CHA erythrocytes, present during remission but accentuated during relapse, seemed to vary with changes in serum erythropoietin. Early differentiation of TEC and CHA appears feasible, allowing prompt provision of a favorable prognosis and the avoidance of unnecessary corticosteroid therapy in TEC.

Adolescent↗
PubMed1976

Congenital hypoplastic anemia.

CHA, a rare failure of erythrogenesis in infancy and childhood, has been re-examined on the basis of a review of 42 cases of our own and 133 others. Although the disease may have its onset late in gestation, severe anemia usually is not found at birth but, in 75% of cases, becomes apparent within the first 4 months. Associated congenital anomalies include abnormal thumbs, webbed neck and growth retardation. Treatment with corticosteroids as soon as the diagnosis is established induces a remission in 80% of patients. Thereafter, this therapy may need to be continued, often at an extremely low dosage level, sometimes intermittently, for many years before the hemoglobin value maintains itself without medication. Spontaneous remission has occurred in a few cases after years of transfusions. Although it has long been considered that the disease was a failure of normal erythrogenesis manifest by a normocytic normochromic anemia, more exact measurements reveal that the anemia is macrocytic, with MCV usually ranging between 100 and 115 mu3. Other abnormalities of the red cells are present; in general, these resemble characteristics of fetal erythrocytes rather than normal adult cells. These red cell changes may persist even after the patient has been in remission for years, thus representing a permanent abnormality in erythrogenesis.

Adolescent↗
PubMedDate not supplied

Quantitative MR imaging of children with sickle cell disease: striking T1 elevation in the thalamus.

Nineteen patients with sickle cell disease (SCD) were examined with conventional MR imaging (cMRI), including T1- and T2-weighted sequences and MR angiography (MRA). qMRI mapping of T1 was also done using a precise and accurate inversion-recovery (PAIR) technique optimized and validated previously. In addition, 21 healthy African-American control subjects had the qMRI examination. Nonparametric Kruskal-Wallis analysis of variance of control subjects, of SCD patients without stroke, and of SCD patients with stroke showed that T1 increased with disease severity in the thalamus, frontal white matter, genu, and occipital white matter. T1 was significantly longer in SCD patients without stroke (n = 13) than in control subjects (n = 21) in the thalamus and frontal white matter. In addition, T1 values were significantly longer in SCD patients with stroke than in patients without stroke in the genu and frontal white matter. Abnormality of the thalamus was identified by qMRI in a substantial fraction of patients read as normal by both cMRI and MRA, suggesting that it may be possible to use T1 elevation to identify a subset of patients with SCD who are at elevated risk for stroke.

Adolescent↗
PubMedDate not supplied

Quantitative MRI of the brain in children with sickle cell disease reveals abnormalities unseen by conventional MRI.

Conventional MRI (cMRI) has shown that brain abnormalities without clinical stroke can manifest in patients with sickle cell disease (SCD). We used quantitative MRI (qMRI) and psychometric testing to determine whether brain abnormalities can also be present in patients with SCD who appear normal on cMRI. Patients 4 years of age and older with no clinical evidence of stroke were stratified by cMRI as normal (n = 17) or abnormal (n = 13). Spin-lattice relaxation time (T1) of gray and white matter structures was measured by the precise and accurate inversion recovery (PAIR) qMRI method. Patient cognitive ability was assessed with a standard psychometric instrument (WISC-III or WISC-R). In all 30 patients with SCD, qMRI T1 was lower than in 24 age- and race-matched controls, in cortical gray matter (P < .0006) and caudate (P < .0009), as well as in the ratio of gray-to-white matter T1 (P < .008). In the 17 patients who were shown to be normal by cMRI, qMRI T1 was still lower than in controls, in both cortical gray matter (P < .02) and caudate (P < .004). Histograms of voxel T1 show that the proportion of voxels with T1 values intermediate between gray and white matter (ie, consistent with encephalomalacia) was 9% higher than controls in patients shown to be normal by cMRI (P < .05) and 15% higher than controls in patients shown to be abnormal by cMRI (P < .0005). The full scale intelligence quotient (FSIQ) of all patients with SCD was 75, compared to the FSIQ of 88 in a historical control group of patient siblings (P < .001). The FSIQ of patients shown to be normal by cMRI was 79, significantly lower than the FSIQ of patient siblings (P < .04). The FSIQ of 71 in patients shown to be abnormal by cMRI was significantly lower than both the patient siblings (P < .005) and the patients shown to be normal by cMRI (P < .04). Patients shown to be abnormal by cMRI scored lower than patients shown to be normal by cMRI, specifically on the subtests of vocabulary (P = .003) and information (P = .03). Cognitive impairment is thus significant, even in patients with SCD who were shown to be normal by cMRI, suggesting that cMRI may be insensitive to subtle neurologic damage that can be detected by qMRI. Because cognitive impairment can occur in children normal by cMRI, our findings imply that prophylactic therapy may be needed earlier in the course of SCD to mitigate neurologic damage.

Adolescent↗
PubMedDate not supplied

Environmental effects of nationwide selenium fertilization in Finland.

To study the possible pollution of natural waters by selenium added to agricultural fertilizers, water selenium concentrations were determined in lakes and ground water pools during the year 1992, when the enrichment of fertilizers by selenium had continued for 8 yr. Water samples were preconcentrated by evaporating, and selenium concentrations were analyzed fluorometrically using the dye 2,3-diaminonaphthalene after wet digestion. In lake water samples from 13 lakes, no significant correlations were found between selenium and pH, chlorophyll A, total nitrogen, or phosphorus. Agriculturally affected and nonaffected lakes had no differences in their selenium concentrations. In the lakes that were surrounded by cultivated fields mean water selenium was 83.4 ng/L (range: 75.2-93.4 ng/L, n = 9). Correspondingly, in lakes situated in forests without agricultural surroundings, mean water selenium concentration was 76.5 ng/L (range: 51.2-110 ng/L, n = 3). Only one lake in the close vicinity of a coal power plant had a high water selenium concentration (mean 272 ng/L). In ground water samples, there was a big variation in selenium levels between different pools, the levels varying between 33 and 260 ng/L. This variation may partly be explained by different selenium concentrations of the bedrock and sediments. However, simultaneous increase of total nitrogen, phosphorus, and selenium levels in consecutive samples from some ground water pools indicates leaching of selenium from the fertilizers into the ground water in certain areas.

2-Naphthylamine↗
PubMedDate not supplied

Serum selenium levels in diabetic children. A followup study during selenium-enriched agricultural fertilization in Finland.

The effect of increased selenium uptake on serum selenium in diabetic children was investigated during the first 9 yr of the Finnish nationwide selenium fertilization program, which started in 1984. Serum selenium concentrations were followed in 237 diabetic children (mean age 8.1 yr) and 214 controls from 1984 to 1992. The control group consisted of 107 siblings of the diabetics and of 107 other healthy children of corresponding age groups. Selenium was determined by direct electrothermal atomic absorption spectrophotometry. The effect of the increased uptake was seen in both diabetic and in control persons. Before the autumn of 1985, diabetic patients had significantly higher serum selenium levels than their siblings or the other healthy controls. Toward the end of year 1987, this difference had disappeared. After that, serum selenium levels continued to increase until the year 1990. In 1990 the mean selenium serum level of diabetic patients was 1.36 mumol/L and that of controls 1.33 mumol/L. The duration of diabetes did not have any effect on selenium serum levels. Slightly higher serum selenium in new diabetic patients before the start of therapy was explained by the dehydration state. The patients who were younger than 3 yr had slightly lower selenium serum levels when compared with older age groups. This difference was observed, however, only during the first 3 yr of the study. After that, when the selenium intake increased in general, no age-dependent differences were found anymore. There were no significant differences in serum selenium levels between males and females in either diabetic patients or in controls.

Adult↗
PubMedDate not supplied

T2-weighted MR imaging for hepatic hemangiomas: comparison of breath-hold and non-breath-hold turbo spin-echo pulse sequences with phased-array multicoil.

BACKGROUND: We compared T2-weighted and heavily T2-weighted breath-hold turbo spin-echo (TSE) sequences with T2-weighted non-breath-hold TSE sequence to evaluate hepatic hemangiomas on magnetic resonance (MR) with a phased-array multicoil. METHODS: Twenty-two patients with 27 hemangiomas were studied at 1.0-T scanner by using T2-weighted and heavily T2-weighted breath-hold TSE sequences (18 s each) and non-breath-hold T2-weighted TSE sequences with use of a phased-array multicoil. Images were quantitatively analyzed for tumor-to-liver signal-difference-to-noise ratios (SD/Ns) and tumor-to-liver signal intensity ratios (T/Ls) and qualitatively analyzed for tumor conspicuity and motion-induced image artifacts. RESULTS: Quantitatively, T2-weighted breath-hold TSE images showed the highest SD/Ns among the three sequences, although the differences from the heavily T2-weighted breath-hold TSE sequence and the T2-weighted non-breath-hold TSE sequence were not statistically significant (p = 0.61 and 0.06, respectively). Heavily T2-weighted breath-hold TSE images showed the highest T/Ls among the three sequences. The differences from the T2-weighted breath-hold TSE sequence and the T2-weighted non-breath-hold TSE sequence were statistically significant (p < 0.001). Qualitatively, breath-hold TSE images were superior to non-breath-hold TSE images in terms of tumor conspicuity (p < 0.01) and motion artifacts (p < 0.01). CONCLUSION: T2-weighted breath-hold TSE sequence is superior to T2-weighted non-breath-hold TSE sequence in the evaluation of hepatic hemangiomas on MR with a phased-array multicoil.

Adult↗
PubMedDate not supplied

An approach for enhancing heterologous production of Providencia rettgeri penicillin acylase in Escherichia coli.

Heterologous production of Providencia rettgeri penicillin acylase (PAC) was optimized in Escherichia coli. Several factors, including carbon, temperature, and host effects, were identified to be critical for the enzyme overproduction. The optimum culture conditions for the enzyme production vary for different host/vector systems. With the optimization, both volumetric and specific PAC activities could be significantly improved by more than 50-fold compared to the native expression in P. rettgeri. The heterologous production could be possibly limited by translation or posttranslational steps, depending on the culture temperature and host/vector system. To our knowledge, this is the first evidence demonstrating the limiting step for the production of P. rettgeri PAC and the existence of the P. rettgeri PAC precursor.

Culture Media↗
PubMedDate not supplied

Fever-range hyperthermia stimulates alpha4beta7 integrin-dependent lymphocyte-endothelial adhesion.

Migration of blood-borne lymphocytes into lymphoid tissues is initiated by the L-selectin and alpha4beta7 integrin adhesion molecules. Previous studies have shown that L-selectin adhesion is dynamically regulated by febrile temperatures. It is now reported that fever-range hyperthermia also acts directly on lymphocytes to enhance selected adhesive functions of alpha4beta7 integrin. Fever-range hyperthermia treatment in vitro (40 degrees C, 12 h) of murine TK1 lymphoma cells and human peripheral blood lymphocytes (PBL) stimulates alpha4beta7 integrin-dependent adhesion to high endothelial venules (HEV) in Peyer's patch and mesenteric lymph node frozen sections. TK1 cells are alpha4beta7hi L-selectin(lo), allowing for the analysis of alpha4beta7 integrin without contributions from L-selectin. Adhesion was further shown to involve alpha4beta7 integrin and its endothelial counter-receptor, mucosal addressin cell adhesion molecule-1 (MAdCAM-1) using function-blocking antibodies (i.e. DATK32, HP2/1, MECA-367). Fever-range hyperthermia also promotes alpha4beta7 integrin-mediated aggregation of TK1 cells. In sharp contrast, hyperthermia fails to increase alpha4beta7 integrin adhesion to fibronectin by TK1 cells. Expression of the alpha4beta7 heterodimer on TK1 cells or human PBL is not altered by hyperthermia, suggesting that hyperthermia stimulates adhesion by enhancing alpha4beta7 integrin avidity rather than its cell surface density. These results provide a mechanism whereby febrile temperatures during infection or clinical hyperthermia potentially amplify the immune response by stimulating L-selectin and alpha4beta7 integrin-dependent homing of immune effector cells to lymphoid tissues.

Animals↗