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Biomedical subjects

Y Lang

Publications and source records attributed to Y Lang.

26 records · Page 2Linked to original sources
PubMed1992

Normal development and behaviour of mice lacking the neuronal cell-surface PrP protein.

PrPC is a host protein anchored to the outer surface of neurons and to a lesser extent of lymphocytes and other cells. The transmissible agent (prion) responsible for scrapie is believed to be a modified form of PrPC. Mice homozygous for disrupted PrP genes have been generated. Surprisingly, they develop and behave normally for at least seven months, and no immunological defects are apparent. It is now feasible to determine whether mice devoid of PrPC can propagate prions and are susceptible to scrapie pathogenesis.

Aging↗
PubMed1992

Processing and presentation of insulin. III. Insulin degrading enzyme: a neutral metalloendoproteinase that is non-homologous to classical endoproteinases mediates the processing of insulin epitopes for helper T cells.

Presentation of a protein antigen to T cells generally requires that the antigen be enzymatically processed into an immunogenic peptide(s). The identification of a protease(s) and its mechanism of action in the proteolysis of such an antigen is therefore a primary goal in the study of antigen processing. We show here that insulin degrading enzyme (IDE), a neutral thiol metalloendoproteinase that is structurally non-homologous to the classical metallo, thiol, acid, or serine proteinases, is relatively specific in its proteolytic activity for insulin and digests human insulin (H(I)) into peptides that are presented by murine TA3 B cell antigen presenting cells (APCs) to HI/I-Ad-reactive T cells. These peptides are, however, not presented by fixed TA3 APCs. Anti-IDE mAbs, after their internalization by TA3 cells, significantly inhibit the presentation of H(I) by these APCs. Immunoblotting experiments demonstrate that this inhibition is mediated by the reactivity of these mAbs with a 110 kDa protein, the known M(r) of IDE. These data show that IDE is an endoproteinase that is involved in the processing of insulin and that this IDE-mediated proteolysis is necessary but not sufficient for the recognition of insulin by T cells. Furthermore, we demonstrate that reduction of the disulfide bonds of a pre-processed A-loop containing heterodimeric insulin peptide is required to further process insulin into a T cell epitope.

Animals↗
PubMed1990

Traumatic central retinal artery occlusion.

A healthy 6-year-old boy with a clinical picture of central retinal artery occlusion (CRAO) of his left eye is presented here. The underlying cause was a trauma to the boy's left cheek some 6 months earlier. Possible pathophysiological mechanisms are discussed. To the best of our knowledge, the late onset of traumatic CRAO has not yet been reported in the literature.

Blindness↗
PubMed1989

[New cloning vectors constructed in Bacillus].

Two new plasmids pNQ216 (4.1kp) and pNQ402 (2.8 kb) were constructed by combining the replication origin of the plasmid pNK289, a cryptic plasmid resides in B. pumilus 289, and the cat-86 gene from plasmid pPL601. These two plasmids can be maintained steadily in both B. subtilis and B. pumilus. The penetrance of these plasmids on LB medium with Cm (20 micrograms/ml) is 30% higher than that of pPL600. Thus both of these plasmids can be used as new cloning vectors in Bacillus.

Bacillus↗
PubMed1989

Behcet disease: long-term follow-up of three children and review of the literature.

Behcet disease is rare in children. There are only two reports of Behcet disease in childhood, describing seven patients. Three pediatric patients are described, in whom the age of onset ranged from 6 to 11 years. Aphthous stomatitis and arthritis were present in all of the patients; genital ulcers, iridocylitis, erythema nodosum, and CNS involvement were present in two patients. Other manifestations included Stevens-Johnson-like eruption, fever of unknown origin, and testicular involvement. All of the patients responded to glucocorticoids; two were also treated with colchicine and one was treated with chlorambucil. In two patients, follow-up of more than 10 years was done, with complete cure in one patient and benign course of illness in the other. Because of the rarity of the disease in childhood and the difficulty in making the diagnosis, there is not enough awareness by pediatricians concerning this disease.

Behcet Syndrome↗
PubMed1987

Intraocular pentastomiasis causing unilateral glaucoma.

We present a case of intraocular pentastomiasis in a 12-year-old Israel Arab boy. A single secondary pentastomid larva, most likely of Linguatula serrata, was found in the anterior chamber of the right eye, attached loosely to the pupil's border by a fibrinous mass. Associated conditions were iritis, subluxation of the lens, and secondary glaucoma. This is the first documentation of human pentastomiasis in Israel.

Arthropods↗
PubMedDate not supplied

Cone-rod dysfunction in patients with unexplained reduction in visual acuity.

Electrophysiologic tests were performed in 233 patients who complained of reduced visual acuity with no satisfactory clinical explanation. The functional integrity of the retina was assessed from the light- and dark-adapted electroretinogram. Macular function and conduction in the optic nerves were estimated from the flash visual evoked potentials. Of the 233 patients 78 were grouped together on the basis of the electrophysiologic and clinical findings. They were characterized by subnormal electroretinogram responses with the cone system more affected than the rod system. The flash visual evoked potential responses were of abnormal waveform and prolonged implicit times. Most of these patients exhibited normal fundi. The reduction in visual acuity, the degree of electroretinogram deficits and the pattern of the visual evoked potential responses were similar in both eyes of each patient, indicating a symmetric disorder. Slight deterioration of visual acuity and electrophysiologic variables were observed in 37 of the patients who were followed up over a period of up to 8 years. The electrophysiologic findings indicate that about 20% of patients complaining of unexplained reduction in visual acuity were suffering from a diffuse retinal disorder affecting the peripheral retina as well as the macular region. On the basis of electrophysiologic findings and clinical symptoms, we suggest grouping these patients under a new entity: cone-rod dysfunction.

Adaptation, Ocular↗