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Biomedical subjects

W L Liu

Publications and source records attributed to W L Liu.

At least 55 records · Page 3Linked to original sources
PubMed1993

[Serum soluble interleukin 2 receptor levels in patients with diffuse connective tissue diseases].

Soluble interleukin 2 receptor (SIL-2R) levels in serum appear to reflect the status of lymphocytic activation and proliferation. We examined the levels of serum SIL-2R in 65 patients with diffuse connective tissue diseases by using ELISA method. The mean levels of serum SIL-2R were respectively 0.46 U/L, 0.53 U/L, 0.46 U/L in systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), and dermatomyositis during disease activity and were significantly higher than those in healthy controls (0.25 U/L). The levels of serum SIL-2R were 0.62 U/L and 0.60 U/L respectively in a patient with mixed connective tissue disease and a patient with systemic sclerosis. The levels of SIL-2R were respectively 0.24 U/L and 0.29 U/L in SLE and RA patients during clinical remission, being significantly lower than during disease activity. SLE patients with high SIL-2R levels were associated with high levels of 125I-DNA rate and erythrocyte sedimentation rate and lower levels of C3 complement components. The measurement of SIL-2R levels may be an useful indicator for monitoring disease activity in SLE and RA patients. Moreover it is a noninvasive method.

Adult↗
PubMed1992

Epidemiology of non-Hodgkin lymphoma in Connecticut. 1935-1988.

BACKGROUND: During the past decades, there have been reports of increases in the incidence and mortality rates due to non-Hodgkin lymphoma (NHL) in many parts of the world. The risk factors responsible for the increasing incidence are largely unknown. This study provided an overview of the incidence pattern of NHL in Connecticut and generated hypotheses for additional investigation. METHODS: This study was based on all the NHL cases reported to the Connecticut Tumor Registry (CTR) between 1935 and 1988. Crude, age-adjusted, and age-specific incidence rates of NHL were calculated for each sex. Age-adjusted incidence rates were calculated by the direct method standardized to the 1970 United States standard million population. The data are presented by calendar year and cohort year of birth to examine the secular trends and birth cohort effects. Racial information was not coded before 1957 and is of uncertain validity until the early 1970s; therefore, racial analysis was restricted to 1970-1988. Analyses by histologic subtypes and by anatomic sites were restricted to the last 3 decades (1960-1988) because more accurate classification systems were used during this time. RESULTS: A total of 11,326 newly diagnosed cases of NHL were included in the study. Of them, 5866 (52%) were diagnosed in men and 5460 (48%) were diagnosed in women. The study results indicated that the incidence rate of NHL has been increasing during the past decades for men and women, whites and blacks, nodular NHL and diffuse NHL, disease originating from lymph nodes and disease originating from other sites, and in all age groups, especially the older age groups. Birth cohort examination did not show any indication of a decline or levelling off in incidence rates among recent birth cohorts. Age-specific incidence rates in both sexes suggested that the rates increase with age, with a sharp increase beginning at 50 years of age and peaking at 80 years of age. Men had a 30% higher incidence rate than women, and whites had approximately 1.5 times the age-adjusted incidence rate of blacks. CONCLUSIONS: The results indicated that the incidence rate of NHL has been increasing in Connecticut during the past decades and is likely to continue to rise in the coming years. Analytical epidemiologic studies are needed to examine the risk factors that might account for the increase in NHL.

Adult↗
PubMed1992

Mechanical restraint use and fall-related injuries among residents of skilled nursing facilities.

OBJECTIVE: To evaluate the association between mechanical restraint use and the occurrence of injurious falls among persons residing in skilled nursing facilities. DESIGN: Prospective observational cohort study. SETTING: Twelve skilled nursing facilities in southern Connecticut. PARTICIPANTS: The 397 persons who were mobile and unrestrained at baseline. MEASUREMENTS: Restraint use was defined both as the number of days restrained and as "never," "intermittently," or "continually" restrained. The primary outcome measure was the occurrence of a serious fall-related injury. Analyses were done on the entire cohort as well as on a subgroup hypothesized as having a high risk for falls. MAIN RESULTS: During one year of follow-up, 122 subjects (31%) became restrained, 83 intermittently and 39 continually. A serious fall-related injury was experienced by 5% (15 of 275) of unrestrained, compared with 17% (21 of 122) of restrained, subjects (chi-square = 12.478; P less than 0.001). Restraint use remained independently associated with serious injury after adjusting for other factors, both in the entire cohort (adjusted odds ratio, 10.2; 95% CI, 2.8 to 36.9) and in the high-risk subgroup (adjusted odds ratio, 6.2; CI, 1.7 to 22.2). Among the 305 subjects who experienced two or fewer falls, the proportion having a serious injury was 15% for restrained subjects compared with 4% for unrestrained subjects (difference in proportions 11%, CI, 4% to 17%), whereas the comparable proportions for the 92 subjects who experienced more than two falls were 20% and 16%, respectively. Results were similar in the high-risk subgroup. CONCLUSIONS: Mechanical restraints were associated with continued, and perhaps increased, occurrence of serious fall-related injuries after controlling for other injury risk factors. Study results suggest the need to consider whether restraints provide adequate, if any, protection.

Accidental Falls↗
PubMed1991

Time trends in malignant melanoma of the upper limb in Connecticut.

Time trends in the incidence of malignant melanoma of the anatomic subsites of the upper limb in Connecticut from 1935 to 1984 were examined. Among males, the incidence of melanoma of the hand was stable, in sharp contrast to the 15-fold to 16-fold increase in the upper arm and forearm. Among females, the 3-fold increase in melanoma of the hand was substantially less than the 12-fold to 14-fold increase in the upper arm and forearm. However, melanoma of the dorsal surface of the hand in females increased sevenfold. These results are in partial agreement with the hypothesis that the hand would be relatively resistant to increased melanoma incidence because it has continually been a sun-exposed site over the decades. The results contradict the hypothesis that the rise in incidence would be greater in the upper arm (a usually unexposed site that has received increasing exposure due to changes in recreation and dress habits) than in the forearm (a site of intermediate exposure).

Arm↗
PubMed1991

Mast cells from human gastric mucosa: a comparative study with lung and colonic mast cells.

Mast cells isolated from human gastric mucosa released histamine on challenge with IgE-directed ligands and calcium ionophores but were essentially unresponsive to a variety of non-immunological stimuli. Moreover, immunologically induced histamine secretion from these cells was inhibited by a number of anti-allergic agents including anti-asthmatic chromones, beta-adrenoceptor agonists and phosphodiesterase inhibitors. In total, these data indicate that mast cells from the human gastric mucosa are in many respects functionally similar to their lung and colonic counterparts.

Anti-Inflammatory Agents, Non-Steroidal↗
PubMed1991

The human skin mast cell: a comparison with the human lung cell and a novel mast cell type, the uterine mast cell.

The functional and histochemical properties of isolated mast cells from human skin, uterine myometrium and lung parenchyma were compared. The skin cell showed a marked difference in responsiveness to both secretagogues and anti-allergic compounds when compared to mast cells from the uterus and lung. The latter cell types responded more strongly to immunologically-directed ligands and calcium ionophores than the skin cell. However, the skin cell released histamine in response to a wide variety of polycationic compounds whilst the lung and uterine cells were essentially refractory to these agents. The antiallergic drugs, disodium cromoglycate (DSCG) and nedocromil sodium, were weakly inhibitory against the skin cell but were in contrast more effective against the lung and uterine cells.

Anti-Inflammatory Agents, Non-Steroidal↗
PubMed1990

Mast cells from human colonic mucosa and submucosa/muscle: a comparison with human lung mast cells.

The functional properties of enzymically dispersed mast cells from human lung parenchyma, colonic mucosa and colonic submucosa/muscle were compared. In general, the cells responded in a similar fashion to the histamine releasing action of a variety of immunological and non-immunological stimuli. However, some differences were observed in their responses to anti-allergic compounds. In total, these data indicate that there are subtle variations between human colonic and pulmonary mast cells but that these differences are much less sharply defined than in the rodent.

Anti-Inflammatory Agents, Non-Steroidal↗
PubMed1990

Patterns of glutamate immunoreactivity in the goldfish retina.

Postembedding silver-intensified immunogold procedures reveal high levels of glutamate immunoreactivity in "vertical" elements of the goldfish retina: (1) Red-sensitive and green-sensitive cones display strong glutamate immunoreactivity, especially in their synaptic terminals, but blue-sensitive cones are poorly immunoreactive. (2) All type Mb (on-center) and Ma (off-center) mixed rod-cone bipolar cells and all identifiable cone bipolar cells are highly glutamate immunoreactive. We find no evidence for bipolar cells that lack glutamate immunoreactivity. (3) The majority of the somas in the ganglion cell layer and certain large cells of the amacrine cell layer resembling displaced ganglion cells are strongly glutamate immunoreactive. (4) Despite their high affinity symport of acidic amino acids, the endogenous levels of glutamate in Müller's cells are among the lowest in the retina. (5) GABAergic neurons possess intermediate levels of glutamate immunoreactivity. Quantitative immunocytochemistry coupled with digital image analysis allows estimates of intracellular glutamate levels. Photoreceptors and bipolar and ganglion cells contain from 1 to 10 mM glutamate. The bipolar and ganglion cell populations maintain high intracellular glutamate concentrations, averaging about 5 mM, whereas red-sensitive and green-sensitive cones apparently maintain lower levels. Importantly, photoreceptor glutamate levels are extremely volatile, and in vitro maintenance is required to preserve cone glutamate immunoreactivity in the goldfish. GABAergic horizontal and amacrine cells contain about 0.3-0.7 mM glutamate, which matches the values predicted from the Km of glutamic acid decarboxylase. Müller's cells and non-GABAergic amacrine cells contain less than 0.1 mM glutamate. Though Müller's cells are known to possess potent glutamate symport, they clearly possess equally potent mechanisms for maintaining low intracellular glutamate concentrations.

Animals↗
PubMed1990

[Blood coagulation changes in systemic lupus erythematosus].

Changes of blood coagulation in 32 cases of SLE were investigated. Abnormalities frequently found were elevation of blood fibrinogen, FDP, V111R: Ag levels, prolonged or shortened KPTT time, and depressed AT-III value. Half of the patients with SLE showed laboratory changes compatible with the diagnostic criteria of DIC, but acute DIC was encountered clinically only in 2 cases hypercoagulation state or hypercoagulation with lower fibrinolysis, however were frequently seen. Lupus anticoagulant were detected in 6 patients and deep vein thrombosis of lower extremity in 1 patient. Examination of blood coagulation in patients with SLE was, therefore, of clinical importance.

Adult↗
PubMed1990

[The application of plasma exchange therapy in refractory diseases].

115 plasma exchange (PE) procedures were performed in 27 patients using the Haemonetics V50 plasmapheresis system 20 patients improved; among them 15 improved remarkably. Adverse reactions were observed 30 times (26.1%). PE showed beneficial effects in certain disease states which did not respond to conventional treatment or traditionally known therapeutic measures, especially patients in critical condition. Prevention and treatment of associated infections are very important in order to obtain a better efficacy of PE.

Adult↗
PubMed1989

Characteristics of histamine secretion induced by neuropeptides: implications for the relevance of peptide-mast cell interactions in allergy and inflammation.

A variety of basic, sensory neuropeptides induced the release of histamine from rat peritoneal mast cells. However, a wide range of other polycationic agents, such as compound 48/80, the mast-cell-degranulating peptide from bee venom and polylysine also activated this cell type. Histamine release induced by all of these agents had characteristic features in common. In each case, the process was extremely rapid, essentially independent of added calcium or phospholipids, not mediated through cell-fixed antibodies, and inhibited by antagonists of the so-called polyamine receptor. The release was also very species- and tissue-specific. All of the compounds were most active against rat serosal mast cells. Tissue mast cells of this species and peritoneal mast cells of other rodents showed graded responses while guinea pig and human mast cells were unreactive. On the basis of these results, the possible role of peptide-mast cell interactions in neurogenic models of inflammation is discussed.

Animals↗
PubMed1989

Changes in cardiac and respiratory function of Antarctic Research Expedition members--preliminary report.

Cardiac and respiratory functions were estimated in 16 Chinese Antarctic Research Expedition members (Third expedition) before and after spending three months in the Antarctic. No significant changes were found in ECG examination. In cardiac function test, prolonged LVET and abbreviated PEP were found. PEP/LVET decreased significantly. Respiratory ventilation function examination showed an increase in FEV1 and FEV25 and a decrease in ERC. Results showed that cardiac and respiratory functions remained almost unchanged in the Expedition members. It is also suggested that a physiological compensation may have occurred in these members' cardiac functions either in the Antarctic or during the return sea voyage.

Antarctic Regions↗
PubMed1988

Effects of sodium cromoglycate and nedocromil sodium on histamine secretion from human lung mast cells.

Sodium cromoglycate and nedocromil sodium produced a dose dependent inhibition of histamine secretion from human pulmonary mast cells obtained by bronchoalveolar lavage and by enzymatic dissociation of lung parenchyma. Both compounds were significantly more active against the lavage cells than against the dispersed lung cells, and nedocromil sodium was an order of magnitude more effective than sodium cromoglycate against both cell types. Tachyphylaxis was observed with the parenchymal cells but not with the lavage cells. Nedocromil sodium and sodium cromoglycate also inhibited histamine release from the lavage cells of patients with sarcoidosis and extrinsic asthma.

Asthma↗
PubMed1988

Serotonergic and serotonin-accumulating neurons in the goldfish retina.

Autoradiography of goldfish retinas incubated in micromolar levels of 3H-serotonin displayed 3 kinds of labeled somas in the inner nuclear layer: S1 amacrine cells with heavy labeling, large somas, and a sparse distribution (approximately 93/mm2); S2 amacrine cells with moderate labeling, smaller somas, and a denser distribution (approximately 500/mm2); and a subset of bipolar cells with light labeling, small somas, and a very dense distribution (approximately 4000/mm2). Serotonin-like immunoreactivity was observed only in S1 amacrine cells and their synaptic terminals. Radiolabeled terminals in the inner plexiform layer formed 4 strata that were differentially assigned to the 3 cell types. S1 amacrine cells arborized in sublayers 1 and 5, received inputs from type a1 bipolar cells and amacrine cells, and made synapses on other amacrine cells, type a1 bipolar cells and unidentified processes. Thus, S1 amacrine cells seem to receive significant input from "off-center" pathways. S2 amacrine cells arborized in sublayer 3 and made synapses onto amacrine cells. Labeled bipolar cell terminals were exclusively located in sublayer 2 and were identified as type a2 mixed rod-cone bipolar cells. We conclude that the S1 amacrine cell is truly serotonergic and that radiolabeling of S2 amacrine cells and type a2 bipolar cells is due to cross-specificity for another carrier or processes unrelated to their neurochemical identities. These observations partially reconcile many previous observations on the types, numbers, and synaptologies of teleost retinal neurons identified by different markers for indoleaminergic transmission.

Animals↗
PubMed1988

Gap junctions in the inner plexiform layer of the goldfish retina.

Oblique thin sections of the goldfish inner plexiform layer (IPL) were examined to characterize the processes engaging in gap junctions. Omission of en bloc uranyl acetate staining enhanced the relative visibility of gap junctions, thus facilitating surveys. Three general categories were identified: (1) extensive gap junctions between large caliber amacrine cell dendrites presynaptic to ganglion cells and other amacrine cells in distal and proximal IPL; (2) moderate to small gap junctions between amacrine cell synaptic terminals or small amacrine cell-like processes of similar cytoplasmic appearance; and (3) gap junctions between the telodendria/terminals of bipolar cells. Most instances of gap junctions in the goldfish IPL seem to represent cases of homologous coupling. We have not found unambiguous cases of heterologous coupling as in the mammalian retina, nor have we yet found mixed synapses. Taken together with previous physiological and anatomical findings, homologous coupling occurs between pairs of rods, cones, horizontal cells, bipolar cells and amacrine cells in the goldfish retina, and this in turn implies that direct intercellular communication among like cell types is a common theme in retinal circuitry.

Animals↗