Hamiltonian formalism for space charge dominated beams in a uniform focusing channel.
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Journal Article↗
Biomedical subjects
D Li
Publications and source records attributed to D Li.
Effects of a nonlinear damping force in synchrotrons with electron cooling.
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Journal Article↗
Scaling function for free-electron-laser gain including alternating-gradient focusing.
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Journal Article↗
Epstein-Barr virus genomes in Hodgkin's disease and non-Hodgkin's lymphomas.
Seventeen of 40 cases of Hodgkin's disease (HD) and eight of 46 non-Hodgkin's lymphomas (NHL) were associated with Epstein-Barr virus (EBV) infection, judged by the EBER-1 in situ hybridization (ISH) method. Approximately 40% incidence in HD was comparable to previous reports. Young children and elderly HD patients were more prone to be found EBV positive. Fourteen of 17 HD and two of 8 NHL cases with positive EBER-1 ISH were also positive on LMP-1 immunostaining. EBV might have a role in lymphomagenesis in these cases. The fact that 7 of 8 EBV-related NHL were peripheral T cell lymphoma indicates the necessity of a larger-scale survey on this subject. As the present study revealed four cases with positive LMP-1 immunostaining but negative EBER-1 ISH (1 HD, 3 NHL), LMP-1 alone should not be regarded as a tool to prove EBV infection.
Adolescent↗
Regulation of manganese peroxidase gene transcription by hydrogen peroxide, chemical stress, and molecular oxygen.
The expression of manganese peroxidase (MnP) in nitrogen-limited cultures of the lignin-degrading fungus Phanerochaete chrysosporium is regulated at the level of gene transcription by H2O2 and various chemicals, including ethanol, sodium arsenite, and 2,4-dichlorophenol, as well as by Mn(II) and heat shock. Northern (RNA) blot analysis demonstrates that the addition of 1.0 mM H2O2 to 5-day-old cultures grown in the absence of Mn results in the appearance of mnp mRNA within 15 min. Higher levels of mnp mRNA are obtained with simultaneous induction by Mn and H2O2 than with H2O2 alone. Although neither MnP activity nor associated protein is detectable in H2O2-induced cultures grown in the absence of Mn, simultaneous induction with Mn and H2O2 results in a 1.6-fold increase in MnP activity compared with the MnP activity resulting from Mn induction alone. In the presence of Mn, purging of low-nitrogen cultures with 100% O2, in contrast to incubation under air, results in an increase in the accumulation of mnp mRNA and a 13-fold increase in MnP activity on day 5. However, in contrast to the effects of H2O2 and heat shock, O2 purging of Mn-deficient cultures results in negligible accumulation of mnp mRNA.
Biodegradation, Environmental↗
Longitudinal study of the health of cotton workers.
OBJECTIVES: To follow up a group of newly employed workers in a cotton mill, and to report changes in symptoms over time. METHODS: A group of 110 mill workers at a cotton mill in Shijiazhuang, China, was investigated by questionnaire, skin testing, and spirometric measurements of airway responsiveness through forced expiratory volume in one second (FEV1). The workers were examined before starting work, at 10 weeks, and at one year. RESULTS: Decreases in FEV1 over shifts were small at 10 weeks and one year, and slightly higher among people with skin reactions to cotton dust extracts. Airway responsiveness, defined as the average decrease in FEV1 after 1.25 mg methacholine was increased at 10 weeks. It remained about the same after one year, except in the workers positive for the skin test, in whom it was further increased. Subjective symptoms of chest tightness and cough with phlegm increased progressively at 10 weeks and one year; nasal irritation remained unchanged and dry cough decreased between 10 weeks and one year. CONCLUSION: The results suggest that the airway inflammation caused by cotton dust increases with increasing exposure time and that the changes are more notable in workers with reactivity to cotton dust extract.
Adolescent↗
Renal arteries: clinical comparison of three-dimensional time-of-flight MR angiographic sequences and radiographic angiography.
PURPOSE: To prospectively compare three magnetic resonance (MR) angiographic techniques in the renal arteries. MATERIALS AND METHODS: Twenty-five adult patients underwent three-dimensional time-of-flight MR angiography with three different sequences: conventional, tilted optimized nonsaturating excitation (TONE), and selective inversion-recovery rapid gradient-echo (SIR-RAGE). Fifteen also underwent radiographic angiography. Stenosis grade measured with each MR angiographic technique was compared with that measured with radiographic angiography by using correlation coefficients. Visible artery lengths with each MR angiographic technique were compared by using the Turkey method. RESULTS: Correlation between stenosis grades with each MR angiographic technique and with radiographic angiography was good (P < .01). Stenosis was correctly excluded with SIR-RAGE findings in six patients. Mean visible artery length was greatest with SIR-RAGE (P < .01). CONCLUSION: SIR-RAGE depicts a greater length of renal artery than does conventional MR angiography. TONE also improved depiction of distal arteries. Normal SIR-RAGE findings were highly predictive of normal arteries.
Adult↗
Protein phosphatase-1 in the kidney: evidence for a role in the regulation of medullary Na(+)-K(+)-ATPase.
Previous studies of hormonal regulation of renal Na(+)-K(+)-ATPase have indicated that the activity of the sodium pump is regulated by phosphorylation-dephosphorylation reactions. Here we report that okadaic acid (OA) and calyculin A (CL-A), inhibitors of protein phosphatase (PP)-1 and PP-2A, inhibited Na(+)-K(+)-ATPase activity in cells from the rat thick ascending limb (TAL) of loop of Henle in a dose-dependent manner. CL-A was 10-fold more potent than OA. On the basis of the inhibitory constant values of CL-A and OA for PP-1 and PP-2A, it is concluded that the tubular effect is mainly due to inhibition of PP-1. In situ hybridization studies with oligonucleotide probes revealed very strong PP-1 alpha and PP-1 gamma 1 mRNA labeling in the outer stripe of the outer medulla, strong labeling in the inner stripe of the outer medulla, and weak labeling in the inner medulla. Very weak labeling was demonstrated in the outer cortex. PP-1 beta mRNA labeling was very strong in the inner stripe of the outer medulla, whereas the outer stripe had weaker labeling, and the inner medulla had weak labeling. PP-1 alpha, PP-1 beta, and PP-1 gamma 1 mRNA were also demonstrated in the transitional epithelium of the ureter. The abundance of the PP-1 alpha and PP-1 gamma isoforms as measured by immunoblotting was very high in tissue from the outer medulla, which also has a high abundance of the endogenous dopamine-regulated PP-1 inhibitor, DARPP-32.(ABSTRACT TRUNCATED AT 250 WORDS)
Animals↗
Prospective study of hospitalization for asthma. A preliminary risk factor model.
We conducted an exploratory analysis of several prospectively obtained objective measures of disease activity to derive a predictive model of hospitalization for asthma among 310 adults, ages 18 to 50 yr, with moderate to severe asthma. Baseline characteristics associated with increased risk of hospitalization in the succeeding year include (1) prior year hospitalization, (2) moderate or severe respiratory impairment, (3) a medication regimen consistent with severe asthma, (4) a history of significant systemic steroid use, (5) maximum overnight PEF variability > 40%, and (6) mean evening PEF < 60% of predicted (relative risk = 6.5, 6.9, 8.1, 3.7, 3.0, and 3.2, respectively). Recursive partitioning analysis, depicted as a "classification tree," provided a more sensitive (94%) and specific (68%) multivariate description of the data set than either logistic regression (87 and 48%, respectively) or a simple additive risk model (46 and 93%, respectively). Patients with very high (> 50%), moderately elevated (10 to 15%), and very low (< 5%) risk of hospitalization were identified on the basis of particular combinations of prior hospitalization history, level of respiratory impairment, and medication regimen. Overnight variability and mean evening PEF measured at home over a 2-wk period proved less informative for risk stratification than respiratory impairment determined once at baseline by office spirometry. The findings warrant replication and extension in other populations with the goal of developing decision rules for risk stratification and effective interventions for risk reduction.
Adult↗
Interleukin-8. Differential expression in lone fibrosing alveolitis and systemic sclerosis.
Fibrosing alveolitis may occur alone (CFA) or in association with systemic sclerosis (FASSc). FASSc was recently shown to have a prognostic advantage over CFA. Because interleukin-8 (IL-8) is likely to be a major determinant of neutrophil alveolitis, we evaluated IL-8 expression in patients with CFA and FASSc and compared it with that in normal individuals and sarcoidosis and systemic sclerosis patients without pulmonary involvement (SSc no FA). IL-8 protein in bronchoalveolar lavage fluid (BALF) was assessed by immunoassay, and IL-8 mRNA expression was assessed using Northern analysis and reverse transcription-polymerase chain reaction (RT-PCR) and in situ hybridization of lung parenchyma. Compared with normal subjects, IL-8 concentration was significantly greater in both CFA (p < 0.001) and FASSc groups (p < 0.05) but no different in sarcoidosis. The IL-8 concentration in CFA was higher than in FASSc (p < 0.01) and was related to BAL % neutrophils (rs = 0.48, p < 0.01). IL-8 mRNA expression evaluated by Northern analysis was seen only in patients with CFA and FASSc and was related to BAL % neutrophils (rs = 0.63, p < 0.01). We suggest that IL-8 is a key factor in the pathogenesis of fibrosing alveolitis and that the poorer prognosis of CFA compared with FASSc is related to higher levels of IL-8 within the lower respiratory tract.
Adult↗
Validation of 99Tcm-HMPAO leucocyte scintigraphy in ulcerative colitis by comparison with histology.
Leucocyte scintigraphy offers an alternative to more invasive techniques in the investigation of inflammatory bowel disease. The accuracy of 99Tcm-HMPAO leucocyte scintigraphy has not been assessed by comparison with colonic histology, which was the aim of this study. 15 patients with ulcerative colitis underwent 99Tcm-HMPAO leucocyte scintigraphy (TLS) less than 5 days before colonoscopy. Histological features of mucosal biopsies were compared with total and segmental colonic TLS scores. Segmental and total scintigraphy scores correlated most strongly with histological grades for acute inflammation (r = 0.75, p < 0.001 and r = 0.9, p < 0.001, respectively) and chronic inflammatory cell infiltration in the lamina propria (r = 0.76, p < 0.001 and r = 0.86, p < 0.001, respectively). 99Tcm-HMPAO leucocyte scintigraphy detected acute inflammation in the colon of patients with ulcerative colitis with a sensitivity of 91% and negative predictive value of 80% and localized acute inflammation to a particular colonic segment with a sensitivity of 82%, specificity of 94%, accuracy of 88%, positive predictive value of 94% and negative predictive value of 91%. 99Tcm-HMPAO leucocyte scintigraphy positivity predicts and localizes colonic acute inflammation with a high degree of confidence, but negative scintigraphy does not exclude acute inflammation.
Adult↗
Short report: prevalence of hantavirus infection in rodents associated with two fatal human infections in California.
Rodents living near two fatal human cases of hantavirus pulmonary syndrome in California were surveyed for evidence of hantavirus infection. Seventeen (15%) (14 Peromyscus maniculatus and one each of P. truei, Eutamias minimus, and Microtus californicus) of 114 rodents tested had evidence (enzyme-linked immunosorbent assay or polymerase chain reaction) of hantavirus infection. This suggests that Peromyscus mice, and P. maniculatus in particular, may be the reservoir for the virus causing this newly recognized disease in California, as previously reported for New Mexico and Arizona.
Adult↗
[Pharmacological research on antiasthmatic liquid for oral administration].
The Oral Antiasthmatic Liquid, when given into the mice stomach, can obviously reduce the times of cough induced by sulfur dioxide aerosol, and increase the amount of phenolsulfonphthalein excretion of tracheas. It also shows antagonistic action to bistamin phosphate and acetylcholine that can contract the isolated tracheas of guinea-pigs, and reduce the amounts of isolated lung and bronchial perfusion of guinea-pigs.
Administration, Oral↗
Construction and expression of 75kDa readthrough protein gene from beet necrotic yellow vein virus.
Using DNA recombinant techniques, coat protein (CP) gene and 54kDa fragment from beet necrotic yellow vein virus (BNYVV) RNA2 were ligated to construct 75kDa readthrough protein gene. Comparing with wild-type 75kDa readthrough protein gene, four nucleotides of the constructed gene were replaced, including CP amber termination codon UAG to AUG. Correspondingly, two amino acids were changed. The temperature inducible expression vectors containing 75kDa readthrough protein gene or its 54kDa fragment were constructed and transformed into E. coli BL21 (DE3), respectively. The results of SDS-PAGE and Western blotting showed that (1) the 75kDa readthrough protein gene was expressed specifically by temperature induction and some smaller protein components, one of which is 37 kDa, were observed as well; (2) only a 37kDa protein was produced from the 54kDa fragment.
Base Sequence↗
Astigmatism analysis after radial keratotomy.
Radial keratotomy without T-cutting was performed on 245 eyes of 124 patients with 6-8 months of post-operative follow-up. The results showed that post-operatively astigmatism was increased in 74 eyes (30.2%) with the increased range from +0.50 to +3.50DC, decreased in 27 eyes (11.0%) and not changed in 144 eyes (58.8%). The main causes of astigmatic change included microperforations, irregular incisions, incisions across the central optical zone and various depths of incisions, etc.
Adolescent↗
[Changes of proto-oncogene expression and cytosolic free calcium in activited T-lymphocytes of aged mice].
Dot blot showed that the expression of proto-oncogene c-fos was inhibited in lymphocytes from old mice (20-24 months). In order to measure the effect of aging on signal transduction, we separated T cells by passage of spleen lymphocytes through long nylon fiber columns. Con A-induced [3H] TdR incorperation in cells from old mice was lower than that from young mice (2 months). The maximum level of [3H]TdR incorperation of old mouse T cells was only 22% of that of young mouse T cells. When T cells were stimulated with the combination of a phorber ester (PMA) and a calcium ionophore (ionomycin), [3H]TdR incorperation remained depressed in old mouse T cells. Further, cytosolic free calcium level was measured by monitoring fluoresence intensity in fura-2/AM loaded T cells. At 10 minutes after con A stimulation, the concentration of cytosolic free calcium ([Ca2+]) in old mouse T cells elevated to 273 x 10(-9)mol/L, while [Ca2+] in young mouse T cells markedly increased to 637 x 10(-9)mol/L. When T cells were stimulated with the combination of PMA and ionomycin, at 7 minutes, [Ca2+] in old mouse T cells elevated to 790 x 10(-9)mol/L, while [Ca2+] in young mouse T cells markedly increased up to 2190 x 10(-9)mol/L.
Aging↗
[Repair of large cranial defect using allogeneic cranial bone and bone morphogenetic protein].
We have successfully treated 4 patients with large cranial defects using a composite of allogeneic cranial bone, BMP (bone morphogenetic protein), pedicled periosteum and skin flap. The size of the cranial defects ranged from 9 cm x 7 cm to 13 cm x 11.5 cm. One to two years' follow-up showed that the wounds in all patients healed primarily with good appearance. The allogeneic bone graft was absorbed and substituted by new bone formation.
Adult↗