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Biomedical subjects

K L Lin

Publications and source records attributed to K L Lin.

35 records · Page 2Linked to original sources
PubMed1997

Biological activity of recombinant Der p 2, Der p 5 and Der p 7 allergens of the house-dust mite Dermatophagoides pteronyssinus.

Der p 2, Der p 5 and Der p 7 are three allergens of the house-dust mite Dermatophagoides pteronyssinus that have been cloned and expressed in Escherichia coli as fusion proteins with glutathione-S-transferase (GST). We showed that these recombinant allergens produced immediate hypersensitivity skin-test reactions in 70, 60 and 52% respectively of a group of mite-sensitive allergic patients who were strongly positive to whole mite extract (WME). Comparable positivities were found for serum levels of specific IgE antibody against these allergens, as measured by the radioallergosorbant test (RAST). Overall, for the group of allergic patients that we evaluated, the serum IgE antibody concentrations against Der p 2, 5 and 7 were calculated to represent about one third, one quarter and one fifth respectively of the levels measured against the WME. However, for some patients the activity determined against the separate allergens was far higher than that detected against the WME, thus indicating that the concentration of these can be limiting in the WME. We found no significant correlations between the RAST levels against Derp 2 and either Derp 5 or 7, and RAST-inhibition tests indicated a lack of cross-reactivity between Der p 2 and the other two allergens. In contrast, the RAST results revealed the existence of a significant immunological relationship between Der p 5 and 7. Although a certain degree of reactivity against the GST fusion partner was found in the allergic patients studied, this was not a significant influence in determining the positivity against the recombinant allergens. These results confirm the in vivo biological activity of recombinant Der p 2, 5 and 7, and indicate that whilst Der p 2 is undoubtedly a major mite allergen, both Der p 5 and 7 make important contributions toward the overall allergenic activity of house-dust mites.

Adult↗
PubMed1997

Sensitization to Blomia tropicalis in patients with asthma and identification of allergen Blo t 5.

In tropical and subtropical regions of the world, allergens produced by Blomia tropicalis are an important cause of IgE-mediated sensitization among patients with asthma. We compared the relative importance of sensitization to the two mite species among asthma patients from Florida, Puerto Rico, and Brazil (n = 83), who were concurrently exposed to B. tropicalis and D. pteronyssinus, with patients from the United States and from the United Kingdom (n = 56) exposed to D. pteronyssinus. In addition, molecular cloning techniques were used to clone and express a major B. tropicalis allergen. There were significant differences between IgE antibody responses to B. tropicalis and D. pteronyssinus that were related to exposure: only 22% of patients exposed to both species had a high ratio (> 10) of IgE D. pteronyssinus:B. tropicalis, whereas 68% of patients exposed only to D. pteronyssinus had a ratio of > 10 (p < 0.001). A major 14-kD allergen (Blo t 5), cloned from a B. tropicalis cDNA library, showed 43% sequence homology to D. pteronyssinus Der p 5. Recombinant Blo t 5 produced in E. coli reacted with 45 to 69% of sera from B. tropicalis-allergic asthmatics and induced positive immediate skin tests at 10(-3) to 1 microg/ml. In vivo and in vitro comparisons of IgE responses to B. tropicalis, D. pteronyssinus, rBlo t 5, and rDer p 5, showed that B. tropicalis has unique allergens that cause specific IgE responses. The results suggest that B. tropicalis is an independent cause of sensitization and that use of recombinant Blo t 5 should lead to a better understanding of the role of B. tropicalis in causing asthma in tropical environments.

Adolescent↗
PubMed1995

Otitis media with effusion in patients with nasopharyngeal carcinoma, postirradiation.

Eighteen patients with nasopharyngeal carcinoma were subjected to eustachian tube function testing before and 6 months and 5 years after irradiation at the university hospital to investigate the chronological changes of tubal function induced by irradiation and to study the development of otitis media with effusion after irradiation. Improvement of tubal function was found 5 years after irradiation in those ears without otitis media. However, in patients who had otitis media with effusion after irradiation, deterioration of tubal function was persistent, and inflammatory reaction was detected in the upper respiratory tract, including the maxillary sinus and nasopharynx. Thus, the development of otitis media with effusion after irradiation in patients with nasopharyngeal carcinoma is attributable to both tubal and inflammatory factors. Insertion of a ventilatory tube in ears can relieve tubal obstruction but can possibly aggravate the inflammatory process. Therefore, it is our opinion that myringotomy plus local treatment may be preferable to insertion of a ventilatory tube in patients with nasopharyngeal carcinoma who have otitis media with effusion.

Adult↗
PubMed1995

Highly efficient expression of fish growth hormone by Escherichia coli cells.

A PCR product encoding the mature segment of fish pregrowth hormone (pre-GH) was inserted into an Escherichia coli expression vector, pET, in which the ori site was replaced by that of pUC19. The yield of recombinant GH (rGH) was as high as 44 to 47% of total protein. This rGH was immunoreactive to GH antibody. After renaturation, rGH was used to inject fish with 0.1 microgram of rGH per g once every 2 weeks, and this resulted in increases in weight (65%), percent weight gain (165%), and length (22%) relative to those of an untreated control group at week 16 and onward.

Amino Acid Sequence↗
PubMed1995

Eustachian tube function of patients with nasopharyngeal carcinoma.

Prolonged observations of the eustachian tube (ET) function were made on 40 ears of 20 patients with nasopharyngeal carcinoma (NPC) who survived more than 5 years after radiotherapy in a state of remission. The ET function tests included passive opening, inflation-deflation, and clearance, and were performed before, at 6 months, and at 5 years after radiotherapy. The test results were found to be worst at 6 months after radiotherapy and improved at 5 years after radiotherapy. Tubal obstruction and inflammation are the main causes of the ET malfunction that results in otitis media with effusion (OME) in NPC patients after radiotherapy. Insertion of a ventilation tube into the ear with OME can relieve tubal obstruction but can aggravate inflammation. Thus, myringotomy and aspiration of effusion and local treatment may be preferable to insertion of a ventilation tube in NPC patients with OME. When hearing improvement in prolonged survival of NPC patients with OME is needed, the use of amplification is recommended.

Eustachian Tube↗
PubMed1994

Characterization of Der p V allergen, cDNA analysis, and IgE-mediated reactivity to the recombinant protein.

A lambda gt11 library for cDNA from Dermatophagoides pteronyssinus was screened by plaque immunoassay, and a number of related clones that produced IgE-binding proteins were isolated. Their sequences were homologous to that of a cDNA described previously, which contained a reading frame encoding a 17 kd polypeptide and which as determined by serologic analysis corresponded to a protein with relative molecular mass of 14 kd in mite extracts. The cDNA from the lambda gt11 clones was truncated so it was used to obtain longer clones from a lambda gt10 library. Analysis of the sequence of these clones showed that the allergen now designated Der p V is produced from a 132-residue polypeptide, which has a putative 19-residue leader peptide and a 113-residue mature protein. This would have a molecular weight of 14 kd, corresponding to that found in mite extracts. IgE binding studies with the lambda gt11 clone and a fusion of the mature sequence in a pGEX construct showed that it reacted with 50% of allergic sera. Further studies with skin tests indicated that it caused reactions in about 60% of patients with asthma and 29% of those with allergic rhinitis alone.

Allergens↗
PubMed1993

Molecular cloning and expression of yellowfin porgy (Acanthopagrus latus houttuyn) growth hormone cDNA.

1. The growth hormone cDNA of yellowfin porgy (ypGH cDNA) consisted of 915 base pairs. 2. The deduced amino acid (aa) sequence showed that the pre-GH comprised 204 residues, of which the first 17 residues formed a signal peptide. 3. Comparison of aa sequence of ypGH to seabream, tuna, rainbow trout and chum salmon showed that ypGH shared 95.1, 94.1, 65.3 and 62.4% homology with these species, respectively. 4. By expressing the ypGH cDNA in E. coli, a polypeptide around 23 kilodaltons (kDa) was found which was immunoreactive to GH antibody.

Amino Acid Sequence↗
PubMed1993

Molecular cloning of a house dust mite allergen with common antibody binding specificities with multiple components in mite extracts.

Plaque radio-immuno assay has been used to isolate an IgE-binding clone from a lambda gt11 library of Dermatophagoides pteronyssinus cDNA. The clone HD6 contained DNA encoding a 215 residue protein which contained a predicted 17 amino acid residue leader sequence, no cysteines and a single N-glycosylation site. The 198 residue mature protein would have a predicted MW of 22,177 D. No homologues were found in searches of the data banks. Sera from 14/38 allergic children reacted strongly with the polypeptide produced by the clone (37%). Skin tests showed reactivity in 16/30 (53%) allergic patients and 0/10 of controls. Affinity purification of rabbit antibodies with the clone showed that antibodies to the polypeptide had specificities to multiple products in mite extracts corresponding to components of Mr 29, 27 and 24 K by Western blotting. Absorption studies of IgE in allergic serum indicated further entities at 13 and 11.5 kD. It is proposed to name this allergen Der p VII.

Allergens↗
PubMed1992

Major histocompatibility complex (MHC) class II restriction, lymphokine production, and IgE regulation of house dust mite-specific T-cell clones.

To elucidate the regulatory mechanism of human IgE synthesis, we have cloned house dust mite (Dermatophagoides pteronyssinus; Dp)-specific T-cell clones from three asthmatic children and three healthy individuals. Twelve clones were cloned from each group. All of these clones were CD3+, CD4+, CD8-, and HLA-DR+. After stimulation with allergen in the presence of antigen presenting cells (APCs), half of the T-cell clones from asthmatic children and one-third of those from normals produced interleukin 4 (IL-4). None of the patients' clones produced interferon gamma (IFN-gamma), while 10 of 12 normals' clones did. After stimulation with calcium ionophore A23187 and phorbol myristic acetate (PMA), the production of IL-4 was markedly increased in both patients and normals. However, only 3 of the 12 patients' clones produced IFN-gamma, while all of the normals' clones did. The T-cell clones of both patients and normals produced comparable IL-2. To study the kinetics of lymphokine productions, a HLA-DRw12-restricted T-cell clone (FYD 3.1) was stimulated, respectively, with a combination of A23187 and PMA, phytohemagglutinin (PHA), or Dp antigen in the presence of APCs. Maximal IL-2 and IL-4 productions were detected 12 hr after A23187 and PMA stimulation, whereas IFN-gamma could not be detected even 36 hr after stimulation. When stimulated with PHA, the production of IFN-gamma peaked on the fourth day, but IL-4 was not detected. After stimulation with Dp antigen and APCs, IL-4 and IL-2 were detected on the second and third days, but IFN-gamma was not detected. The IgE production by autologous purified B cells in the presence of allergen or IL-4 was found to be augmented by the FYD 3.1 T-cell clones. IFN-gamma was observed to counteract the effects of the T-cell clones and IL-4. Thus, the secretory patterns of lymphokine and kinetics of lymphokine production of allergen-specific T-cell clones can be used to explore the regulatory mechanism of human IgE synthesis [corrected].

Adult↗
PubMed1991

Mouse dander-allergic bronchial asthma--a case report.

A case of mouse dander-allergic bronchial asthma is reported. A 47-year-old female professor of pharmacy has experienced severe chest discomfort, dyspnea and wheezing, and itching nose and eyes each time when she contacted with mice in recent months although she has done animal (mouse) experiments for many years without any difficulty. Those symptoms usually recovered spontaneously after removing the mice or using bronchodilator. The causal relationship between mouse dander and bronchial asthma was established, in addition to history of exposure, by a positive skin test, a strong RAST and overwhelming bronchial provocation test. The allergen was identified, by SDS-PAGE and immunoblotting to be a 21 Kd molecule.

Allergens↗
PubMed1991

Analysis of house dust mite-specific IgE, IgG4, and IgG antibodies during immunotherapy in asthmatic children.

House dust mite (Dermatophagoides pteronyssinus, DP) specific IgE, IgG4, and IgG antibodies were analyzed by Western blotting in 18 asthmatic children during the course of 2-years' allergen-specific immunotherapy. Although more than 50 protein bands could be identified in the crude mite extracts by SDS-PAGE, only eight of them elicited both IgE and IgG4 antibodies in most patients. The molecular weights were 110, 60, 55, 43, 33, 27, 16, and 14 kD, respectively. No antibodies against new antigens were induced after immunotherapy. There was a significant correlation between the intensity of reactive bands of Western blotting and RAST. IgG4 antibody was increased in 72% (13/18) of patients, but the simultaneous change in IgE varied. Analysis of allergen-specific IgE and IgG4 antibodies by Western blotting may provide a useful tool for evaluation of clinical response to immunotherapy.

Adolescent↗
PubMed1990

Rice pollen allergy in Taiwan.

A panel of tests including intracutaneous skin testing (ST), radioallergosorbent test (RAST), immunoblotting and allergen-induced lymphoproliferation was done to study rice pollen allergy in asthmatic children and to characterize the allergens. Of the 312 asthmatic patients skin tested, 29 (9.3%) had positive reactions (wheal greater than or equal to 6 mm) to rice pollen extract at a concentration of 10(-5) g/mL and the remaining 283 (90.7%) were negative. While eight (34.8%) of the 23 ST-positive patients were also RAST-positive, RAST was negative in all 34 ST-negative patients and 20 normals. Immunoblotting revealed three major allergens, with molecular weights of 16 kD, 26 kD, and 32 kD, respectively. Interestingly, RAST-positive patients showed IgE responses to most allergens but only a few of them had IgG antibodies, while normal controls had stronger IgG responses to the same allergens, particularly to 32 kD, but none had IgE antibody. The preliminary results of rice pollen protein induced-lymphoproliferation were not informative; thus, rice pollen proteins do elicit a specific response in asthmatic children and normals, but its pathogenic role in bronchial asthma needs further study.

Adolescent↗
PubMed1975

High-resolution proton nuclear magnetic resonance studies of sickle cell hemoglobin.

High-resoluiton proton nuclear magnetic resonance spectroscopy at 250 MHz has been used to investigate sickle cell hemoglobin. The hyperfine shifted, the ring-current shifted, and the exchangeable proton resonances suggest that the heme environment and the subunit interfaces of the sickle cell hemoglobin molecule are normal. These results suggest that the low oxygen affinity in sickle cell blood is not due to conformational alterations in the heme environment or the subunit interfaces. The C-2 proton resonances of certain histidyl residues can serve as structural probes for the surface conformation of the hemoglobin molecule. Several sharp resonances in sickle cell hemoglobin are shifted upfield from their positions in normal adult hemoglobin. These upfield shifts, which are observed in both oxy and deoxy forms of the molecule under various experimental conditions, suggest that some of the surface residues of sickle cell hemoglobin are altered and they may be in a more hydrophobic environment as compared with that of normal human adult hemoglobin. These differences in surface conformation are pH and ionic strength specific. In particular, upon the addition of organic phosphates to normal and sickle cell hemoglobin samples, the differences in their aromatic proton resonances diminish. These changes in the surface conformation may, in part, be responsible for the abnormal properties of sickle cell hemoglobin.

Adult↗
PubMedDate not supplied

Ectopic ACTH syndrome due to thymic carcinoid tumor in a girl.

An 8 year-old girl had a cushingoid appearance for six months. Hormone study showed extremely high serum levels of cortisol (> 60 micrograms/dl) and adrenocorticotropic hormone (930 pg/ml). Initial chest X-ray showed nothing unusual, but a technetium-99mm MIBI scan showed an accumulation lesion in the left upper chest cavity. Chest magnetic resonance imaging demonstrated that the mass was in the superior anterior mediastinum. She had complete removal of the tumor with partial thymectomy. The pathology revealed a thymic carcinoid tumor. Carcinoid tumors of the thymus are extremely rare in children and they usually present with Cushing's syndrome. To our knowledge, this is the youngest patient who has ever been reported with this disease.

ACTH Syndrome, Ectopic↗