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Biomedical subjects

Y S Lu

Publications and source records attributed to Y S Lu.

At least 55 records · Page 3Linked to original sources
PubMed1991

Glomerular diseases in human renal allograft.

A total of 64 renal graft biopsies performed on 44 transplant patients from among 116 transplants (12 from living donors, 104 from cadavers) were analyzed during the period from July 1983 to December 1990. The frequency of allograft glomerular disease was 22.7% (10/44). Membranous glomerulonephritis (MGN) was detected in five patients; focal segmental glomerulosclerosis (FSGS), in two; transplant glomerulopathy, in two; and IgA nephropathy, in one. Nephrotic syndrome occurred in nine of the ten patients. Progressive deterioration of graft function developed in four patients associated with chronic rejection, and two of them later lost the graft. The remaining six patients had no chronic rejection and retained a stable renal condition with one exception, a patient who suffered from acute total occlusion of the right internal iliac artery and who eventually lost the graft. It is concluded that MGN is the most common allograft glomerular disease, but the outcome of the graft is probably related to the coexistent chronic rejection.

Adult↗
PubMed1991

A consecutive ultrastructural study of action of homoharringtonine on fibroblasts in vitro.

The authors studied the effect of homoharringtonine (Hh), a semisynthetic Chinese herb, on the ultrastructure of in vitro cultured human conjunctival fibroblasts (HFb) and its mechanism of action. Preliminary results showed that the main characteristics of HFb damage caused by Hh were invagination of the nuclear membrane, aggregation and margination of chromatin, and massive vacuolization of the cytoplasm. In addition, Hh can inhibit the secretion of collagen fibers and the synthesis of microfilaments. Therefore, Hh might be an effective agent in the prevention and treatment of proliferative eye disorders.

Actin Cytoskeleton↗
PubMed1990

Biological evaluation of Mycoplasma pulmonis temperature-sensitive mutants for use as possible rodent vaccines.

Temperature-sensitive mutants (TSMs) of Mycoplasma pulmonis were produced by treating the wild-type strain with N-methyl-N'-nitro-N-nitrosoguanidine. Three TSMs were selected at 38 degrees C, as a restrictive temperature, and at 34 degrees C, as a permissive temperature. Two TSMs, UTCMI and UTCMII, were proven to be nonpathogenic but immunogenic. In addition, they did not induce pneumonia, tracheitis, or tympanitis but did induce mild rhinitis. They were stable after 10 passages in vitro and in vivo. They elicited excellent antibody production and cell-mediated immunity in vaccinated rats. They also were not mitogenic to rat lymphocytes. Rats immunized intranasally with these TSMs were significantly protected against challenge with wild-type organisms. These mutants were morphologically and serologically indistinguishable from the wild-type organisms. The growth characteristics and antibiotic sensitivities were similar to those of wild-type organisms, except that they grew only at 34 degrees C. In contrast to wild-type organisms, they did not bind to or lyse sheep erythrocytes. Thus, these TSMs may qualify as a vaccine to prevent M. pulmonis infection in rats.

Animals↗
PubMed1989

Persistant abnormal serum parathyroid hormone after renal transplantation: correlation between renal graft function.

Secondary hyperparathyroidism in uremia renal transplantation. We studied the i-PTH (immunoactive parathyroid hormone) of nineteen immunoactive parathyroid hormone) of nineteen patients before and after renal transplantation with average of 20 months post transplantation. In group I patients with normal i-PTH serum level had an significant lower serum level of creatinine than Group II with elevated abnormal i-PTH. While the calcium and phosphorus showed no significant difference between group I and Group II patients. We suggested that abnormal serum i-PTH level after renal transplantation after one year was closely related to renal graft function. This group of abnormal serum i-PTH should be closely monitored for their renal graft function.

Calcium↗
PubMed1988

Identification of immunogenic outer membrane proteins of Pasteurella multocida 3:A in rabbits.

Four groups of protective rabbit immune sera were used to identify Pasteurella multocida outer membrane immunogens by a radioimmunoprecipitation procedure and Western blot (immunoblot) analysis. These are rabbit hyperimmune sera against KSCN extract of P. multocida (group 1) and rabbit immune sera against the KSCN extract of P. multocida (group 2), the outer membrane of P. multocida (group 3), and live P. multocida cells (group 4). Rabbits mounted an antibody response to 18 proteins found in the outer membrane of P. multocida, and the major antibody activities were directed to the 27,000-molecular-weight outer membrane protein (27K protein), as well as the 37.5K, 49.5K, 58.7K, and 64.4K outer membrane proteins. These outer membrane immunogens appear to be exposed on the cell surface and accessible to antibodies, since adsorption of these immune sera with intact P. multocida cells resulted in a significant reduction of antibody activities directed against these proteins, especially the 37.5K protein. Antibodies eluted from immune serum-P. multocida cell complexes were reactive to the 37.5K immunogen, confirming that this protein is exposed on cell surface and accessible to antibodies. Western blot analyses with group 1, 3, and 4 immune sera confirmed that the 27K, 37.5K, 49.5K, 58.7K, and 64.4K proteins are the major outer membrane immunogens of P. multocida in rabbits. Lung lavages of immunized rabbits also contained similar antibody activities directed against several outer membrane proteins, with major activities against the 37.5K and 64.4K proteins.

Animals↗
PubMed1988

Distribution of a monoclonal antibody-recognized protective protein immunogen on the outer membranes of Pasteurella multocida rabbit isolates.

The distribution of a monoclonal antibody (MAb)-recognized protective protein immunogen on the outer membrane of 153 Pasteurella multocida rabbit isolates was determined by dot blot (DB) analysis. MAb 1608 reacted with 36 (24%) of the 153 clinical isolates. The DB-positive clinical isolates expressed capsular antigens A, D, and nontypable and somatic antigens 2, 3, 10, 12, 15, and nontypable. Western blot (immunoblot) analysis with adsorbed and eluted MAb 1608 confirmed that the antigenic determinant identified was located on the cell surface. With MAb 1608 as a probe for antibody-accessible radioimmunoassay, 31 of 36 DB-positive P. multocida rabbit isolates were shown to have surface-exposed and antibody-accessible antigenic determinants, while 44 of 44 DB-negative isolates were negative by antibody-accessible radioimmunoassay. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis revealed DB-negative P. multocida isolates both with (6 of 13, 46%) and without (7 of 13, 54%) the 37.5-kilodalton protein. This study establishes that the protective antigenic determinant of the 37.5-kilodalton outer membrane protein is present in 24% of rabbit clinical isolates tested and is detectable in P. multocida strains distributed among the major somatic types (3, 10, 12, and 15) and the capsular types (A and D) commonly isolated from rabbits in North America.

Animals↗
PubMed1988

Serum IgE in primary glomerular diseases and its clinical significance.

Total serum IgE was measured in 119 cases of primary glomerular diseases and 33 normal healthy persons. Statistically significant higher levels were noted in minimal change disease (MCD; median: 630 U/ml), IgM nephropathy (IgMN; 618 U/ml), focal glomerulosclerosis (FGS; 373 U/ml) and membranous glomerulonephritis (MGN; 144 U/ml). A higher level of serum IgE was noted in association with more frequent relapse or steroid resistance in MCD and IgMN and in FGS with nephrotic syndrome. A small group of IgA nephropathy with nephrotic range proteinuria was also noted to have extraordinarily high serum IgE. These findings suggest that IgE may play an important role in the pathogenesis of MCD, IgMN, and FGS and may serve as a prognostic indicator in terms of steroid responsiveness in MCD and IgMN.

Adolescent↗
PubMed1988

Experimental Mycoplasma pulmonis infection of rats suppresses humoral but not cellular immune response.

Humoral antibody response to sheep red blood cells and cellular immune response to bovine serum albumin were studied in Mycoplasma pulmonis infected, adult, male Sprague-Dawley rats. The hemagglutinating antibody response to sheep red blood cells was evaluated at 0, 3, 5, 7, 14, 21 and 28 days postinfection. Antibody titers during all days postinfection were depressed significantly (p less than 0.05) in infected rats as compared to noninfected controls. Cellular immune responses were evaluated by a delayed hypersensitivity response. Rats were sensitized at 0, 3, 5, 7, 14, 21 or 28 days postinfection with bovine serum albumin and challenged with heat aggregated bovine serum albumin 7 days later. Cell-mediated immune responses in infected rats were not significantly different at any point from controls. These results indicate that M. pulmonis infection in rats suppresses the humoral antibody response to sheep red blood cells, but not the cellular immune response to bovine serum albumin.

Animals↗
PubMed1988

The effect of transportation stress on splenic natural killer cell activity in C57BL/6J mice.

Splenic natural killer cell activity and plasma corticosterone levels were measured in air- and truck-transported C57BL/6J mice (Mus musculus) on days 0, 1, 3 and 5 post-arrival. These data are important in determining adequate stabilization periods for transported animals before studies involving natural killer cells are begun. Three control groups (phosphate buffered saline, polyinosinic-polycytidylic acid, and hydrocortisone injected mice) were stabilized in the animal facilities 3 weeks before the start of experiments. Natural killer activity in transported mice was reduced significantly (p less than 0.05) on day 0 and returned to normal levels by 24 hours. Plasma corticosterone levels were increased significantly (p less than 0.005) on day 0 and returned to control levels by day 1, correlating inversely with splenic natural killer activity. This study indicates that stress resulting from transportation causes a short-term decrease in the splenic natural killer cell activity of mice, and this decrease may be related to the increased plasma corticosterone levels induced by the stressful event. We conclude that mice should be stabilized at least 24 hours before experiments involving the natural killer cell system are begun.

Animals↗
PubMed1987

A potassium thiocyanate extract vaccine prepared from Pasteurella multocida 3:A protects rabbits against homologous challenge.

Potassium thiocyanate extracts of a virulent Pasteurella multocida 3:A rabbit isolate were prepared and used as a vaccine in rabbits. The extract contained protein, carbohydrate, hyaluronic acid, lipopolysaccharide, DNA, and RNA. The protein and lipopolysaccharide profiles of the extract were similar to those of the P. multocida cell membrane. Rabbits were vaccinated intranasally (i.n.) or intramuscularly (i.m.) four times at 1- or 3-week intervals and challenged i.n. with the homologous P. multocida 2 weeks after the last vaccination. Rabbits vaccinated with the extract by the i.n. route developed persisting serum immunoglobulin G (IgG) and nasal IgA antibodies, whereas rabbits immunized by the i.m. route produced persisting serum IgG and transient nasal IgA antibodies. The extract prevents the death of rabbits which were vaccinated by either route and challenged. Vaccination by the i.n. route in rabbits reduced the numbers of virulent P. multocida in nasal cavities and lungs and the prevalence and severity of rhinitis and pneumonia. These i.n.-vaccinated rabbits were also resistant to virulent P. multocida colonization in liver, spleen, uterus, and tympanic bullae. Similarly, i.m. vaccination in rabbits resulted in a reduction in the severity of rhinitis; the numbers of virulent P. multocida in lungs; and the prevalence of colonization in liver, spleen, uterus, and tympanic bullae. Vaccination by the i.n. route was superior to that by the i.m. route in that there was a significant reduction in the severity of pneumonia and numbers of virulent P. multocida in nasal cavities and lungs. Rabbits vaccinated with the extract without challenge showed no lesions.

Administration, Intranasal↗
PubMed1987

Hyperimmune serum from rabbits immunized with potassium thiocyanate extract of Pasteurella multocida protects against homologous challenge.

Hyperimmune rabbit sera directed to the KSCN extract of 3:A Pasteurella multocida were characterized by enzyme-linked immunosorbent assay (ELISA), presolubilized cell radioimmunoprecipitation, and immunoblotting analysis. The results showed that the hyperimmune serum had a very high titer of immunoglobulin G ELISA antibody and a negligible immunoglobulin A ELISA antibody, precipitated 10 different outer membrane protein antigens by radioimmunoprecipitation, and reacted to 10 different membrane vesicle antigens of P. multocida by immunoblotting analysis. The hyperimmune rabbit sera were also evaluated for protective efficacy against experimental rabbit pasteurellosis by homologous challenge. Thirty-six rabbits were divided into four groups. Group 1, 2, and 3 rabbits were inoculated intranasally with hyperimmune rabbit serum, phosphate-buffered saline, or normal rabbit serum, respectively, at 24 h prior to and 24, 48, and 72 h after intranasal challenge with the virulent homologous P. multocida strain. Group 4 rabbits were inoculated with normal rabbit serum without challenge. Necropsies of surviving rabbits were performed 2 weeks postinfection. The mortality rates for groups 1 through 4 were 25% (3 of 12), 67% (8 of 12), 75% (6 of 8), and 0% (0 of 4), respectively. The prevalence and severity of pneumonia were significantly lower in the hyperimmune serum-treated rabbits. The prevalence of P. multocida colonization in lungs was significantly lower in group 1 rabbits, and the geometric mean CFU of P. multocida in lungs was 59,166-fold less in group 1 rabbits than in group 3 rabbits. The geometric mean CFU of P. multocida in nasal cavities of group 1 rabbits was significantly lower than that of group 3 rabbits. All challenged rabbits (groups 1,2, and 3) had elevated nasal immunoglobulin A and pulmonary (lung lavage) immunoglobulin A antibody levels at necropsy (day 14 postinfection). Similarly, all challenged rabbits had elevated levels of ELISA immunoglobulin G antibody in serum at day 14 but not at day 7 postinfection, indicating that rabbits receiving hyperimmune serum can mount a specific humoral immune response against the homologous challenge P. multocida organisms. We concluded that hyperimmune serum directed to the KSCN extract of 3:A P. multocida provides significant protection against homologous challenge in rabbits.

Animals↗
PubMed1987

Pharmacokinetics of penicillin-G in serum and nasal washings of Pasteurella multocida free and infected rabbits.

Treatment of infections due to Pasteurella multocida in rabbits usually consists of a single intramuscular injection of penicillin G and results in variable cure rates. We report here the levels of penicillin G in serum and nasal washings in P. multocida free and P. multocida infected rabbits following a single intramuscular injection over a 24 hours period. These levels were compared to the minimal inhibitory concentrations (MICS) of 50 clinical isolates of P. multocida of rabbit origin. Infected rabbits demonstrated higher serum levels of penicillin G over P. multocida free rabbits at 1, 3, and 5 hours after the injection. At 16 and 24 hours the penicillin G serum levels dropped to 0.14 and 0.07 microgram/ml, respectively, from 1.90 micrograms/ml at 8 hours. At these levels of penicillin G only 20% of the isolates tested in vitro for susceptibilities (MICs) would be inhibited. Levels of penicillin G in nasal washings at 4 hours after injection were 0.063 microgram/ml, or one-fourth the MIC of 80% of the P. multocida isolates tested (0.25 microgram/ml). In contrast, serum levels of approximately 5 micrograms/ml were seen at this time. Our results suggest that therapeutic blood levels could be achieved if rabbits are given injections of procaine penicillin G at 8 hour intervals.

Animals↗
PubMed1987

Mycoplasma pulmonis infection augments natural killer cell activity in mice.

The goal of this study was to determine if experimental Mycoplasma pulmonis infection augmented splenic natural killer (NK) cell activity in mice. A 4 hour 51Cr-release in vitro assay using YAC-1 tumor target cells was employed to measure splenic NK cell activity in C57BL/6J mice infected intraperitoneally with M. pulmonis and in uninfected controls. Transient augmentation of the NK cells was observed, peaking at day 3 postinoculation (PI) and gradually returning to normal levels by day 10 PI. Selective depletion studies showed that the cells responsible for killing target cells were NK cells. They were nonadherent to nylon wool, not susceptible to Thy-1.2 antibody and susceptible to asialo GM1 ganglioside antibody. Inadvertent augmentation of the NK cell system due to M. pulmonis infection may complicate the interpretation of research data, especially in immunology and cancer studies.

Animals↗
PubMed1986

Spermicidal effect in vitro by the active principle of garlic.

The in vitro spermicidal effect of Allitridum, an active principle of garlic, was investigated. The data showed that sperm motility was inhibited with various concentrations of Allitridum at different intervals ranging from 20 seconds-200 minutes as compared to control. An obvious immobilization of spermatozoa occurred at 7.5 mg/ml of Allitridum. The effects on sperm motility appeared to be dose-dependent.

Allyl Compounds↗
PubMed1986

Comparison of Chalquest and Hayflick media, with and without ammonium reineckate, for isolating Mycoplasma pulmonis from rats.

Chalquest and Hayflick media with and without ammonium reineckate were compared for isolation of Mycoplasma pulmonis from the nasopharyngeal ducts, tracheobronchial trees, and middle ears of 66 naturally infected rats. The results show that 92% (366 of 396) of the samples were positive for M. pulmonis in Chalquest medium with and without ammonium reineckate and 66% (260 of 396) were positive in Hayflick medium with and without ammonium reineckate (P less than 0.001). An enhancing effect of ammonium reineckate on M. pulmonis isolation was observed only in Hayflick medium; the isolation rate was 76% (151 of 198) in Hayflick medium with ammonium reineckate as compared with 55% (109 of 198) in Hayflick medium without ammonium reineckate (P less than 0.03). No significant differences in isolation rates were observed between Chalquest medium with and without ammonium reineckate. The mean growth time of M. pulmonis on Chalquest medium was 3.4 days as compared with 5.1 days in Hayflick medium, indicating that M. pulmonis can be detected earlier on Chalquest medium than on Hayflick medium. These data indicate that Chalquest medium is superior to Hayflick medium for M. pulmonis isolation from rats.

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↗