Biomedical subjects

S Pan

Publications and source records attributed to S Pan.

At least 127 records · Page 7Linked to original sources

PubMed1993

An immunologic study on age-related macular degeneration.

Forty-one patients with age-related macular degeneration (AMD) were detected for serum autoantibodies against normal human retinal protein by means of Western immunoblot analysis. Twenty-seven out of the 41 patients showed positive response, with a rate of 66 per cent. The positive rate of anti-retinal antibody in the AMD patients was significantly higher than that in normal controls (18%) and in patients with other retinal diseases (24%) (p < 0.0005). These antiretinal antibodies from the AMD patients partly reacted with the retinal protein of molecular weight between 28 and 32 Kd, partly with Mr of 38 to 42 Kd, 48 to 52 Kd, 62 to 65 Kd or 110 to 130 Kd. Of them, the antiretinal antibody against the protein with Mr of 28 to 32 Kd in the AMD patients was higher than in normal controls (p < 0.05). Two or more antibodies were found in the serum from AMD patients, showing a significant difference between the patients and the controls (p < 0.005). The results indicated that in the occurrence of AMD and/or during its developing process there were inflammation and immunological response, involving antibodies against retinal proteins of various molecular weight.

Aged↗

PubMed1993

[Effect of superoxide dismutase on experimental allergic uveitis].

In this study, experimental allergic uveitis (EAU) in guinea pigs was induced by an injection of bovine serum albumin (BSA) into the vitreous after having pre-immunized them intradermally with BSA plus incomplete Freund adjuvant, and the effect of superoxide dismutase (SOD) on EAU was observed. The result showed that, histopathologically, the phlogistic cell infiltration and exudation within the anterior ocular part of the SOD- treated animals reduced notably. It is suggested that SOD which can scavenge the free radical superoxide anion may alleviate the cellular reaction in the pathological process of uveitis.

Animals↗

PubMed1993

[Study on human gamma-crystallins: IV. Photooxidation of fetal gamma 2-crystallin by ultra-violet irradiation].

Human fetal gamma 2-crystallin solution was irradiated by ultra-violet (UV) (lambda 365 nm) at varying time, and analysed by light scattering, SDS-PAGE with DACM, which could specifically combine to free sulphydryl, as well as tryptophan fluorescence and its quenching with acrylamide. The results showed that light scattering of gamma 2-crystallin solution increased after 24 hour irradiation; SDS-PAGE reveled formation of dimer which did not have free sulphydryl and low molecular weight peptide of gamma 2-crystallin. The tryptophan fluorescence of gamma 2-crystallin decreased, and acrylamide fluorescence quenching effect did not show significant change. It suggested that human fetal gamma 2-crystallin photooxidized by UV could aggreate by disulfide and degrated to low molecular weight peptide, and its tryptophan were also oxidized in some degree.

Crystallins↗

PubMed1993

Use of calcium antagonist (nifedipine) in premature labour.

Effectiveness of nifedipine in suppressing premature uterine activity was studied on 20 normal pregnant women who received, depending on the frequency of uterine contractions and degree of cervical dilatation, 5-10 mg nifedipine orally 8 hourly till the uterine contractions were abolished followed by 5 mg 12 hourly up to 38 weeks of gestation. Another 20 age, gravida and gestational period matched normal pregnant women received 10 mg isoxsuprine hydrochloride orally 8 hourly till the uterine contractions were abolished, followed by 10 mg 12 hourly up to 38 weeks of gestation. Successful tocolysis was observed in 85% of cases receiving nifedipine in contrast to 40% of women receiving isoxsuprine hydrochloride. The mean time from presentation to delivery and mean birth weight were 21.8 days and 2510 g respectively in isoxsuprine hydrochloride treated cases and 34.2 days and 2750 g respectively in cases treated with nifedipine. In either group there were no serious untoward effects on mother, labour and baby.

Adult↗

PubMed1992

Sequence and variability of the 5.8S and 26S rRNA genes of Pneumocystis carinii.

The sequence of the coding region of the rRNA operon of rat-derived Pneumocystis carinii has been completed, including the genes for 5.8S and 26S rRNA. These genes show homology to the rRNA genes of yeast, and an apparent group I self-splicing intron is present in the 26S rRNA gene. Like a similar intron in the 16S rRNA gene, this intron is in a phylogenetically conserved region. Variation in the 26S rRNA sequence was noted between P. carinii organisms isolated from two different sources.

Base Sequence↗

PubMed1992

Evidence for clonal expansion of T cell receptor V gamma II+ T cells in the synovial fluid of patients with arthritis.

We have demonstrated among synovial fluid T cells a unique profile of V gamma II sequences likely arising from clonally expanded T cells. We have determined the junctional diversity associated with each expressed V gamma family by resolving amplified fragments of cDNA into component parts on large denaturing gels. Among synovial fluid T cells we frequently find dominant fragments of a unique size clearly smaller than the dominant band observed with peripheral blood T lymphocytes. In some cases the dominant bands are 12 or 15 nucleotides smaller than the corresponding most abundant band from peripheral blood T lymphocytes. Patterns of lower m.w. species not typical of a polyclonal population argues that clones of T cells expressing the V gamma II family are expanding in the joint and that a high proportion of these cells do not express the V gamma IIJP sequence typical of peripheral blood but rather express V gamma II in combination with a shorter J fragment, JP1, JP2, J1, or J2. In addition by examining joint effusions from the left and right knees from the same individual we have shown that the profiles of V gamma II sequences derived from the fluids are identical to each other but clearly distinct from that of peripheral blood. We have, in addition, quantitated with a series of synthetic internal standards the relative usage of each V gamma family expressed by T cells in the synovial fluid and peripheral blood of seven patients with arthritis including six patients who were either children or adolescents and one adult patient. All patients showed a reduction in the relative expression of V gamma II in synovial T cells relative to peripheral blood T lymphocytes and a corresponding increase in the expression of V gamma I or V gamma III or both. We did not detect expression of V gamma IV in either lymphocyte population.

Arthritis↗

PubMed1992

Electrophoretic karyotypes of clinical isolates of Coccidioides immitis.

Chromosomes of the fungal respiratory pathogen, Coccidioides immitis, were separated by contour-clamped homogeneous electric field gel electrophoresis. Twelve isolates were examined, the majority of which showed four chromosomes with a range of molecular size from 11.5 to 3.2 Mb. Three isolates (C634, C735, and L) revealed three chromosomal bands under the conditions employed for electrophoretic separation. However, in two of these isolates (C634 and C735), four chromosomes were visible on membrane transfers of pulsed-field gels after Southern hybridization between the chromosomal DNA and selected DNA probes. The probes included a conserved ribosomal gene and three previously described cDNAs isolated from C. immitis expression libraries. The L isolate was determined to have the same genome size as a typical four-chromosome isolate on the basis of microspectrophotometric comparison of fluorescence intensity of the ethidium bromide-stained nuclear DNA. The genome size of C. immitis determined by microspectrophotometry was approximately 28.2 +/- 2.6 Mb. The calculated genome size based on addition of the average molecular weights of chromosomal bands separated by contour-clamped homogeneous electric field gel electrophoresis was approximately equal to the estimate derived from the spectrophotometric analyses. This is the first report of the electrophoretic karyotype of C. immitis.

Blotting, Southern↗

PubMed1992

Purification of bovine interphotoreceptor retinoid-binding protein and its uveitogenicity in Lewis rats.

Interphotoreceptor retinoid-binding protein, IRBP, not only functioning as a shuttle to carry the retinoid between photoreceptor cells and pigment epithelium, but also inducing experimental autoimmune uveoretinitis (EAU), was purified by ConA Sepharose affinity chromatography from the fractions containing IRBP obtained in the course of ion-exchange chromatography by which the bovine retinal S-antigen was purified. This much simplified method allows more rapid purification of the two kinds of protein. EAU was successfully induced with injecting 50 micrograms of IRBP emulsified with Freund's complete adjuvant into the right hind footpads of Lewis rats. It was characterized by panophthalmia or endophthalmia with the severest damage in the posterior retina. Lymphocytes, mononuclear and polymorphonuclear cells were found to be the inflammatory cells of infiltration, with lymphocytes being predominant.

Animals↗

PubMed1992

[Studies on human gamma-crystallins. I. Quantitative changes with age and cataract formation].

Water soluble protein from human lenses at various ages are separated by Sephadex gel chromatography. The results show that there are major three gamma-crystallins (gamma 1, gamma 2, gamma 3) in human lenses. In normal lenses the total contents of the three gamma-crystallins in water soluble fraction of lens proteins keep stable as age increases. However, among the three gamma-crystallins, gamma 1 increase and gamma 2 decrease markedly, and very little change with gamma 3 are found as age increases. In nuclear cataractous lenses, all three gamma-crystallins decrease as compared with the normal lenses of the same age. The variety of synthesis of each gamma-crystallin is mainly responsible for the changes of their quantities. It is postulated that the total low molecular weight crystallin contents in water soluble proteins of the human lens is related to the transparency of lens. The structural characterization of gamma 3-crystallin is responsible for the relative constant as age increases.

Adolescent↗

PubMed1992

Potassium iodide and acrylamide fluorescence quenching studies on gamma-crystallins of human lenses in development and aging.

gamma 1-, gamma 2- and gamma 3-crystallin (corresponding to gamma s-, gamma C- and gamma D-crystallin respectively) of human fetal, 2 year and 20+ year old lenses are separated by Sephadex gel chromatography. Iodide and acrylamide are used to quench the tryptophane fluorescence of sub-gamma-crystalline fractions and Ksv and fa values are calculated. The results show that iodide has no clear quenching effects on all gamma-crystallins, the quenching effects of acrylamide on the tryptophan fluorescences of gamma 1-, gamma 2- and gamma 3-crystallin from lenses of the same age have little differences, and the quenching rates of tryptophane fluorescences of gamma 1-crystallin decreases and that of gamma 2- and gamma 3-crystallin increase with age. These results indicate that all tryptophan residues in these three gamma-crystallins lie in hydrophobic environments of molecule and their exposure degree is in the order gamma 2 < gamma 3 < gamma 1. The tryptophan exposure of gamma 2 and gamma 3 increase (gamma 2 > gamma 3) and of gamma 1 decrease with age. The age related change of gamma 1 may be related to the changing of structure or containing of new constituents. Although the tryptophan exposure in gamma 3 is higher than that in gamma 2, the change of structure with age in gamma 2 is more prominent than in gamma 3.

Acrylamides↗

PubMed1992

Effects of qingkailing on experimental allergic uveitis in rabbits.

Experimental allergic uveitis (EAU) in rabbits was induced by single intraocular injection of bovine serum albumin (BSA). The average of protein concentration in aqueous humor of untreated group of rabbits was 14.33 +/- 1.21 mg/ml and the count of tritiated thymidine (3H-TdR) incorporated into lymphocyte T was 3,987 +/- 1,156cpm/10(6). The specific antibody responses to BSA in the serum and the aqueous were 0.508 +/- 0.034 and 0.369 +/- 0.019 (OD) respectively. Meanwhile, the effect of Qingkailing on EAU was observed in comparison with dexamethasone as the positive control. The inflammatory reactions of rabbits treated with Qingkailing were remarkably diminished clinically and pathologically. The amount of protein concentration in aqueous of the treated rabbits was 5.79 +/- 2.19 mg/ml (P < 0.01) and the count of 3H-TdR incorporation was 2,455 +/- 981cpm/10(6) (P < 0.05). The responses of antibody in the serum and the aqueous were 0.414 +/- 0.059 and 0.253 +/- 0.041 (P < 0.01) respectively. Our observations indicate that Qingkailing has a positive therapeutic effect on EAU in the rabbits and sustain the suggestion that this drug is capable of suppressing immune and phlogistic reactions.

Animals↗

PubMed1992

T cell receptor V beta usage in synovial fluid of children with arthritis.

We have examined synovial fluid (SF) T cells from 5 children with various types of juvenile arthritis. Using the polymerase chain reaction (PCR) to determine the expression of 20 individual T cell receptor (TCR) beta variable (V) region families, we have shown with each patient that the SF T cells are polyclonal. Nevertheless, expanded usage of some families by SF T cells relative to peripheral blood T cells was evident in some cases. We conclude that the pattern of T lymphocytes in the inflamed joint may be a consequence in part of a polyclonal expansion or nonspecific homing of T cells to the joint, and in part a more restricted expansion of T cells potentially driven by arthritogenic antigens.

Antibodies, Antinuclear↗

PubMed1991

Participation of noradrenergic neurotransmission in angiotensin III-induced dipsogenic behavior in the rat.

Conscious, adult, male Sprague-Dawley rats, instrumented with in-dwelling cannula for drug application into the lateral cerebral ventricle, were used to evaluate the participation of noradrenergic neurotransmission in angiotensin III (AIII)-induced dipsogenic behavior. Intracerebroventricular (i.c.v.) administration of AIII (20, 40 or 80 pmol) elicited a robust and dose-related drinking response. Chemical lesion produced by i.c.v. injection of the catecholaminergic neurotoxin, 6-hydroxydopamine (25 micrograms x 3), or the selective noradrenergic neurotoxin, N-(2-chloroethyl)-N-ethyl-2-bromobenzylamine (250 micrograms), promoted significant antagonization of the dipsogenic behavior produced by AIII (40 or 80 pmol, i.c.v.). Under equimolar doses (3.25 or 6.50 nmol), the specific alpha 1-adrenoceptor blocker, prazosin, antagonized; the specific alpha 2-adrenoceptor antagonist, yohimbine, enhanced; and the nonselective alpha-adrenoceptor blocker, phentolamine, elicited minimal action, on AIII (40 pmol)-induced drinking response. These results suggest that central noradrenergic neurotransmission may participate actively in AIII-induced dipsogenesis, in a process that may involve both alpha 1- and alpha 2-adrenoceptors.

Adrenergic alpha-Antagonists↗

PubMed1991

Adenosine deaminase and thymocyte maturation.

The congenital absence of adenosine deaminase in humans results in severe combined immunodeficiency. To clarify the process whereby thymocytes are destroyed in the absence of adenosine deaminase activity, we induced a parallel condition in mice through the injection of an inhibitor of adenosine deaminase, deoxycoformycin. We have observed that deoxycoformycin, in addition to maintaining high levels of dATP in thymocytes, blocks the progression of thymocyte differentiation at two points. As a result of the first block, the cortex is depleted of immature cortical thymocytes while CD4+CD8+ thymocytes with functionally rearranged T-cell receptors survive. As a result of the second block, the CD4+CD8+ thymocytes are prevented from further differentiation to mature CD4+CD8- or CD4-CD8+ T lymphocytes and accumulate at the corticomedullar junction and in the medulla. These observations suggest that the maintenance of dNTP pools by adenosine deaminase is critical to at least two stages of thymocyte differentiation.

Adenosine Deaminase↗

PubMed1991

Epithelial lining of sinus tracts associated with periapical disease: an immunocytochemical study using monoclonal antibodies to keratins.

We examined 30 specimens of mucosal sinus tracts arising in association with periapical inflammation. Immunocytochemistry and a panel of monoclonal antibodies to keratins were used to demonstrate the epithelial lining and its pattern of keratin expression. Half of the specimens were found to have an epithelial lining that was continuous with the mucosal epithelium and showed various degrees of extension into the sinus. The presence of an epithelial lining appeared to correlate with the duration of the sinus tracts. The immunostaining patterns of the epithelial linings were similar to those of the mucosal epithelium near the sinus opening although some differences were found. Proliferating strands of epithelium, presumably derived from the rest of Malassez, were observed deep in the tissues but were not continuous with the epithelial lining. The results suggest that the epithelial lining of sinus tracts is derived not from epithelial rests in the periapical region but from the mucosal epithelium adjacent to the opening of the sinus tract and that the observed changes in the pattern of keratinization are due to the influence of inflammation or of the connective tissue substrate.

Antibodies, Monoclonal↗

PubMed1991

Acute esophageal ulcer with massive bleeding: an unusual complication of uremic patient during hemodialysis.

Inflammatory mucosal changes of upper gastrointestinal (GI) tract including stomach and duodenum are well documented in uremic patients and assumed to be the major source of upper GI bleeding. However, acute esophageal ulcer which causes massive bleeding on hemodialysis is rare. Herewith a case is reported. A 28-year-old male uremic patient had a sudden onset of hematemesis on hemodialysis. Urgent endoscopy revealed an acute mucosal lesion with bleeding at the upper and middle third esophagus. It was demonstrated by esophageal biopsy. The patient had taken some pepper one day before and was choked during hemodialysis. This special condition is suggested to induce the acute esophageal ulcer and bleeding.

Adult↗

PubMed1991

Serum biochemical and histological changes in caerulein-induced acute pancreatitis in rats: a correlative study.

We investigated correlations between serum biochemical changes and pathological alterations in caerulein-induced acute pancreatitis in rats. Seven consecutive doses of caerulein consisting of 50 mu g/kg, were given intraperitoneally, in 40 male Sprague-Dawley rats at hourly intervals. Serum biochemical and histological changes of the rats were studied at hours 7, 9, 12, 18, 24 and 36 after the first injection, as well as day 3 and 5 respectively. Serum amylase in the controlled rats (n = 6) was 2549 +/- 221 U/L (mean +/- SE). It was elevated to twenty times that of the baseline value (52630 +/- 11397 U/L) at the seventh hour, declined to about two times the control (5520 +/- 800 U/L) at the 18th hour, and returned to the baseline level at the 24th hour after the first caerulein injection. Serum lipase, elevated since the 7th hour, reached its peak value (631 +/- 34 U/L) at the 12th hour, then declined abruptly to the baseline value (0 U/L) at the 24th hour, after the first injection. However, severe histological changes of the pancreas were apparent at the 7th hour, reaching maximal destruction at the 18th hour, with severe inflammatory changes at the 24th hour; all after the first injection. The frank inflammation did not subside until 5 days after the first injection. These results suggest that, in the case of acute pancreatitis, normalization of serum biochemistries does not indicate recovery of the pancreas from acute inflammation.

Acute Disease↗

PubMed1991

[Longitudinal changes of serum specific antibodies in Lewis rats immunized with IRBP].

The serum antibodies specific to either interphotoreceptor retinoid-binding protein (IRBP) or retinal S-antigen were longitudinally determined in Lewis rats immunized with 50 x 10(-6)g of IRBP emulsified with complete Freund's adjuvant. To our knowledge, it is the first time to purify IRBP and to address the experiment with IRBP in China. It was shown that the antibody specific to IRBP appeared on the 7th day, followed by a gradual increase, and reached its peak on the 26th day after immunization. No antibody specific to S-antigen was found. The relation between anti-IRBP antibody and experimental autoimmune uveoretinitis (EAU) which occurred in the increasing phase of the antibody suggests that the humoral immunity may be implicated in the pathogenesis of EAU.

Animals↗