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Biomedical subjects

J L Lan

Publications and source records attributed to J L Lan.

71 records · Page 4Linked to original sources
PubMed1989

Immunoblot analysis of allergens in crude mosquito extracts.

Whole body extracts of Aedes albopictus (AAL), Aedes aegypti (AAE) and Culex quequectates (CQU) were subjected to sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) analysis. At least 28, 37 and 26 polypeptides, molecular weights (MWs) ranging from 16 to 120 kilodaltons (kD), respectively, were visible following Commassie brilliant blue staining. Sera of two mosquito-sensitive patients were examined for IgE binding to mosquito proteins by immunoblotting. Sera from both patients revealed IgE binding to 52- and 56-kD proteins of AAL. In addition, serum from patient B also bound 48 kD of AAL and did not bind any components of AAE and CQU. Serum from patient A also bound 32 and 58 kD of AAE, and bound only 58 kD of CQU. Sera from 2 control subjects, nonatopic and mosquito-negative atopic, did not bind specific human IgE to any proteins, as demonstrated by negative autoradiographs. Immunoblot analysis showed unique individual IgE-binding patterns and suggested that both genus- and species-specific mosquito allergens exist.

Aedes↗
PubMed1988

Cockroach hypersensitivity: isolation and partial characterization of major allergens.

Two allergenic fractions in crude American cockroach extract have been isolated with Sephadex G-150 SF gel filtration and diethylaminoethylcellulose ion exchange chromatography. The partially purified fractions of Cr-PI and Cr-PII elicit 73% and 93% of patients sensitive to the crude extracts, respectively. Crude extract contains at least 29 antigenic components, as demonstrated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and crossed immunoelectrophoresis. Eighteen allergenic arcs are identified by crossed radioimmunoelectrophoresis. Electroblotting analysis with sodium dodecyl sulfate-polyacrylamide gel electrophoresis reveals nine allergenic components of molecular weights of 120,000, 110,000, 90,000, 78,000, 72,000, 49,000, 45,000, 29,000, and 26,000 daltons that are able to bind specific IgE. Among these nine principal allergens, two components of molecular weights 78,000 and 72,000 daltons bound 100% of the sera of atopic patients tested. These two proteins are undoubtedly the major allergens of American cockroach extract.

Allergens↗
PubMed1988

Cockroach hypersensitivity: preliminary study of allergic cockroach asthma in Taiwan.

One hundred eight-two atopic patients were skin tested with cockroach antigen. Of these 182 patients, 54.9% gave positive immediate skin reaction by intracutaneous test. Among those atopic patients tested, 57.5% of patients with asthma and 50.7% of patients with allergic rhinitis were sensitive to cockroach extracts. The specific IgE antibody was determined by fluoroallergosorbent test. Of 79 cockroach-positive atopic patients, 39.2% were found to contain IgE antibodies against cockroach. No specific IgE was detected in cockroach-negative atopic and nonatopic subjects. Bronchial provocation test with cockroach antigen was performed on 15 subjects. Immediate asthmatic response was detected in six of nine cockroach-positive subjects with asthma. Two cockroach-negative subjects with asthma and four nonatopic subjects demonstrated no significant decrease in FEV1. The results indicate that cockroach induces antigen-specific IgE-mediated bronchial asthma, and cockroach is one of the major causes of allergic asthma.

Adolescent↗
PubMed1988

Gangliosides suppression of murine lymphoproliferation and interleukin 1 production.

Studies were carried out to determine whether inhibition of gangliosides on lymphoproliferation was related to interleukin (IL)-1. The results showed that gangliosides, GM1 and GT1b were able to inhibit the proliferation of spleen lymphocytes from C57BL/6J mice in dose-dependent fashion, whereas asialo-GM1 was not inhibitory. However, gangliosides, GM1 and asialo-GM1 did not suppress the production of IL-1 in Salmonella typhosa lipopolysaccharide (LPS)-induced peritoneal adherent cells. Various types of LPS including S. enteritidis, S. minnesota and Escherichia coli 055:B5 were used to stimulate the production of IL-1 in adherent cell cultures. The IL-1 production was not affected by gangliosides, GD1a and GD1b. Although GT1b suppressed IL-1 production of human monocytes to 82% of control level it did not, however, affect the IL-1 production of murine adherent cells. Thus, the inhibitory mechanism of gangliosides on murine immune cells remains unclear, and warrants further study.

Animals↗
PubMed1988

Effect of gangliosides on primary and secondary plaque-forming cells responses and on suppressor T-cells induction.

This study was designed to determine the suppressive effect of bovine brain gangliosides on primary and secondary anti-sheep red blood cell (SRBC) plaque-forming cells (PFC) response. Spleen cells from inbred C57BL/6J mice were used as sources of lymphocytes. The result showed that levels of gangliosides at 50 and 100 micrograms/ml suppressed primary anti-SRBC PFC responses about 30% and 60%, respectively, of normal control. In contrast, secondary anti-SRBC PFC were not suppressed by the same levels of gangliosides. Likewise, PFC response from mixing SRBC-primed T-cells with naive B-cells was not suppressed by gangliosides. In addition, induction of suppressor T-cells was reduced by 50 and 100 micrograms/ml of gangliosides, 57% and 63%, respectively, versus 86% of suppression of PFC response by the control suppressor T-cells. These results further suggest the role of gangliosides as immunomodulators.

Animals↗
PubMed1986

Glomerulonephritis in ankylosing spondylitis.

There have been a few reports suggesting the association between glomerulonephritis (GN) and ankylosing spondylitis (AS). The reported glomerulonephritides include IgA nephropathy, mesangial proliferative GN and membranous nephropathy. From January 1983, through December 1984, we observed 5 cases of GN among 116 cases of definite AS. Three of them were IgA nephropathy. The other two were mesangial proliferative GN, with IgM deposit in one case and isolated C3 deposit in another. Microscopic hematuria was observed in all of them. The renal function and 24-hour urine protein excretion were all within normal limits. Serum IgA level increased in all but the case of mesangial proliferative GN with IgM deposit. All except one had the antigen of HLA-B27. Serum IgA level was determined in 78 cases (86 estimations) of AS. The mean value was 399.6 +/- 15.0 mg/dl (mean +/- SE) (normal range: 100-350 mg/dl). Fifty-four of them (63%) had a value higher than 350 mg/dl. The interrelationship of AS and IgA nephropathy was discussed.

Adult↗
PubMed1985

[Autologous mixed lymphocyte reaction in systemic lupus erythematosus].

The autologous mixed lymphocyte reaction in patients with systemic lupus erythematosus was lower than that of normal individuals (p less than 0.05). The impairment was not due to the dysfunction of various regulatory lymphocytes, but there was a negative correlation with the B cell function. The low autologous mixed lymphocyte reaction was found in patients with high B cell function.

Adolescent↗
PubMed1985

Smooth muscle antibody in children with acute rheumatic fever and rheumatic heart disease.

Smooth muscle antibody (SMA) was positive in 66.7% of children with acute rheumatic fever, in 46.1% of children with chronic rheumatic heart disease, and in only 11.9% of normal Chinese children. These findings indicate that the SMA is one of the bioproducts of acute rheumatic fever and rheumatic heart disease, but the immunopathogenetic role of SMA in these particular disease still needs further investigation.

Acute Disease↗
PubMed1982

A proposed criteria for diagnosis of systemic lupus erythematosus used in Veterans General Hospital.

An eight-point diagnostic criteria for SLE was proposed and evaluated at the Veterans General Hospital (VGH), Taipei. It consists of 8 points and 12 items, 3 points being required for an accurate diagnosis. All of 94 cases of SLE whether they could or could not be diagnosed with the ARA criteria fulfilled 3 or more points of the VGH criteria. None of the 17 cases of rheumatoid arthritis fulfilled 3 or more points of the VGH criteria.

Adolescent↗
PubMed1982

Studies on lymphocyte subpopulations and lymphocyte transformation in response to phytohemagglutinin, pokeweed mitogen, concanavalin A in systemic lupus erythematosus.

Forty-eight cases of systemic lupus erythematosus (SLE) were studied for lymphocyte subpopulations, and 42 cases were studied for lymphocyte response to mitogen stimulation. A decreased percentage of thymus-derived cells (T cells) and an increased percentage of bursa-equivalent derived cells (B cells), null cells (N cells), double labelled cells (D cells) were found in non-treated cases of SLE. There was no significant difference in these lymphocyte subpopulations in the treated cases in comparison with the normal control. There was an inverted linear relationship between T cells and N cells (p less than 0.001). No such relationship was found between B cells and N cells. The lymphocyte transformation in response to phytohemagglutinin (PHA), pokeweed mitogen (PWM) and concanavalin A (Con A) was expressed in three ways: (1) the net count of transformed data, (2) the difference between the square roots of the isotope incorporation in the stimulated and the non-stimulated cultures (Dsq), and (3) the stimulation index (SI). There were significantly decreased lymphocyte transformation in response to PHA, PWM stimulation in both the non-treated and the treated cases of SLE when results were expressed as net count and Dsq. But decreased counts in response to Con A was only found in non-treated cases. In contrast, no significantly lowered response to all three mitogens was found when data were expressed as stimulation index. Simultaneous study of the percentages of T cells, B cells, N cells, and D cells might be helpful in assessing the clinical activity of SLE and monitoring the effect of therapy. In the study of lymphocyte response to mitogen stimulation, Con A response was a more sensitive indicator of disease activity. The stimulation index was not a good method to demonstrate the result of lymphocyte response to mitogen stimulation in cases of SLE.

Concanavalin A↗
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↗
PubMedDate not supplied

Solid phase radionuclide esophageal transit in mixed connective tissue disease.

Esophageal motility was studied in 24 patients with mixed connective tissue disease (MCTD) and 20 control subjects by the solid phase radionuclide esophageal transit study. A computer routine modified from Klein and Russel was used. Total mean transit time, regional mean transit time, residual fraction after first swallow, and retrograde index increased significantly in MCTD patients compared with normal control subjects. An abnormal total mean transit time occurred in 84% (20 of 24) of the patients with MCTD. Our results confirmed that delayed esophageal transit is common in patients with MCTD.

Adolescent↗