Biomedical subjects

L Cheng

Publications and source records attributed to L Cheng.

At least 55 records · Page 3Linked to original sources

PubMed2001

Quantitative analysis of hydrocortisone in human urine using a high-performance liquid chromatographic-tandem mass spectrometric-atmospheric-pressure chemical ionization method.

In this study, the development and validation of a method of analysis for 11,17,21,-trihydroxypregn-4-ene-3,20-dione (hydrocortisone, cortisol, HC) using high-performance liquid chromatography (HPLC)-tandem mass spectrometry (MS) with atmospheric-pressure chemical ionization (APCI) is reported. This is the first report of the systematic development and validation of an HPLC-MS-MS method for the quantitation of HC in synthetic human urine with a deuterated internal standard. Prior to LC-MS-MS analysis, the only sample preparation used was the dilute-and-shoot technique prior to LC-MS-MS analysis. In this study, an analysis time of less than 3 min is achieved. The results show freedom of interference from other analytes such as analogous steroids. Validation parameters such as specificity/selectivity, limit of quantitation (LOQ), linearity, precision, accuracy, ruggedness, stability, and system suitability are evaluated for this method. The LOQ is 5 ng/mL with an 8% relative standard deviation (RSD). For calibration standard curves, an average linear response for a 3-day validation (R2 = 0.997) over the range of 5 to 500 ng/mL is obtained. The interday precision %RSDs are 7.2, 5.0, and 5.2 for 15, 75, and 300 ng/mL, respectively. Also, brief comparisons of the dilute-and-shoot and liquid-liquid extraction techniques for this analyte are discussed.

Chromatography, High Pressure Liquid↗

PubMed2001

Expression, purification, characterization and clinical relevance of rAed a 1--a 68-kDa recombinant mosquito Aedes aegypti salivary allergen.

Accurate diagnosis of mosquito allergy has been precluded by the difficulty of obtaining salivary allergens. In this study, we expressed, purified, characterized and investigated the clinical relevance of a recombinant Aedes aegypti salivary allergen, rAed a 1. Two cDNA segments were ligated together to form the full-length Aed a 1 gene. rAed a 1 was expressed using a baculovirus/insect cell system, and purified using a combination of anion-exchange and gel-filtration chromatography. The purified rAed a 1 bound to human IgE, as detected by ELISA, ELISA inhibition tests and immunoblot analyses. Epicutaneous tests with rAed a 1 and a commercial whole-body AE: aegypti extract, and AE: aegypti bite tests were performed in 48 subjects. Nine of 31 (29%) of the subjects with positive immediate bite tests also had a positive rAed a 1 immediate skin reaction and 32% had an positive immediate test to the commercial extract. Six of 33 (18%) of the subjects with positive delayed bite tests also had a positive rAed a 1 delayed skin reaction and 6% had a positive delayed test to the commercial extract. Furthermore, rAed a 1-induced flare sizes significantly correlated with mosquito bite-induced flare sizes. None of the subjects with negative bite tests had a positive skin test to rAed a 1 or to commercial extract. We conclude that the rAed a 1 has identical antigenicity and biological activity to native Aed a 1, can be used in the in vitro and in vivo diagnosis of mosquito allergy, and is more sensitive than mosquito whole-body extract for detecting delayed skin reactions.

Aedes↗

PubMed2001

The relationship between photosystem II efficiency and quantum yield for CO(2) assimilation is not affected by nitrogen content in apple leaves.

Bench-grafted Fuji/M.26 apple (Malus domestica Borkh.) trees were fertigated with different concentrations of nitrogen by using a modified Hoagland's solution for 45 d. CO(2) assimilation and photosystem II (PSII) quantum efficiency in response to incident photon flux density (PFD) were measured simultaneously in recent fully expanded leaves under low O(2) (2%) and saturated CO(2) (1300 micromol mol(-1)) conditions. A single curvilinear relationship was found between true quantum yield for CO(2) assimilation and PSII quantum efficiency for leaves with a wide range of leaf N content. The relationship was linear up to a quantum yield of approximately 0.05 mol CO(2) mol(-1) quanta. It then became curvilinear with a further rise in quantum yield in response to decreasing PFD. This relationship was subsequently used as a calibration curve to assess the rate of non-cyclic electron transport associated with Rubisco and the partitioning of electron flow between CO(2) assimilation and photorespiration in different N leaves in response to intercellular CO(2) concentration (C(i)) under normal O(2) conditions. Both the rate of non-cyclic electron flow and the rate of electron flow to CO(2) or O(2) increased with increasing leaf N at any given C(i). The percentage of non-cyclic electron flow to CO(2) assimilation, however, remained the same regardless of leaf N content. As C(i) increased, the percentage of non-cyclic electron flow to CO(2) assimilation increased. In conclusion, the relationship between PSII quantum efficiency and quantum yield for CO(2) assimilation and the partitioning of electron flow between CO(2) assimilation and photorespiration are not affected by N content in apple leaves.

Carbon Dioxide↗

PubMed2001

Soil temperature and plant growth stage influence nitrogen uptake and amino acid concentration of apple during early spring growth.

In spring, nitrogen (N) uptake by apple roots begins about 3 weeks after bud break. We used 1-year-old 'Fuji' Malus domestica Borkh on M26 bare-root apple trees to determine whether the onset of N uptake in spring is dependent solely on the growth stage of the plant or is a function of soil temperature. Five times during early season growth, N uptake and total amino acid concentration were measured in trees growing at aboveground day/night temperatures of 23/15 degrees C and belowground temperatures of 8, 12, 16 or 20 degrees C. We used (15NH4)(15NO3) to measure total N uptake and rate of uptake and found that both were significantly influenced by both soil temperature and plant growth stage. Rate of uptake of 15N increased with increasing soil temperature and changed with plant growth stage. Before bud break, 15N was not detected in trees growing in the 8 degrees C soil treatment, whereas 15N uptake increased with increasing soil temperatures between 12 and 20 degrees C. Ten days after bud break, 15N was still not detected in trees growing in the 8 degrees C soil treatment, although total 15N uptake and uptake rate continued to increase with increasing soil temperatures between 12 and 20 degrees C. Twenty-one days after bud break, trees in all temperature treatments were able to acquire 15N from the soil, although the amount of uptake increased with increasing soil temperature. Distribution of 15N in trees changed as plants grew. Most of the 15N absorbed by trees before bud break (approximately 5% of 15N supplied per tree) remained in the roots. Forty-six days after bud break, approximately one-third of the 15N absorbed by the trees in the 12-20 degrees C soil temperature treatments remained in the roots, whereas the shank, stem and new growth contained about two-thirds of the 15N taken up by the roots. Total amino acid concentration and distribution of amino acids in trees changed with plant growth stage, but only the amino acid concentration in new growth and roots was affected by soil temperature. We conclude that a combination of low soil temperature and plant developmental stage influences the ability of apple trees to take up and use N from the soil in the spring. Thus, early fertilizer application in the spring when soil temperatures are low or when the aboveground portion of the tree is not actively growing may be ineffective in promoting N uptake.

Amino Acids↗

PubMed2001

Molecular genetic evidence for different clonal origin of components of human renal angiomyolipomas.

Renal angiomyolipoma is a benign neoplasm composed of variable proportions of blood vessels, smooth muscle, and adipose tissue. Smooth muscle, adipose tissue, blood vessels, and adjacent normal kidney tissue were separately microdissected from sections prepared from formalin-fixed, paraffin-processed tissues from angiomyolipomas from 18 women. X chromosome inactivation analysis using the methylation pattern at exon 1 of the human androgen receptor gene on chromosome Xq11-12 was used to study the clonal origin of each component. Nonrandom inactivation of X chromosomes was found in six of the 15 informative tumors. The smooth muscle and adipose tissue showed differing patterns of nonrandom inactivation of X chromosomes in five angiomyolipomas and the same pattern of nonrandom inactivation of X chromosomes in one. Samples from the blood vessels showed random inactivation of X chromosomes in all informative cases. Our data showed that the adipose tissue and smooth muscle cells of renal angiomyolipoma are both monoclonal but may arise independently. The coexistence of tumor subclones with morphologic heterogeneity can lead to the formation of a clinically detectable tumor.

Adipose Tissue↗

PubMed2001

Applying practical preventive skills in a preclinical preceptorship.

Learning primary care medicine includes learning to apply practical, preventive medicine skills during everyday encounters with patients. The authors relate their experiences with implementing a voluntary, preventive diabetic foot-care program within the Texas Statewide Family Practice Preceptorship Program (TSFPPP). They explain the background of the TSFPPP and their rationale for introducing prevention and selecting diabetic foot care as a first preventive training module. The program's structure, educational materials, and evaluations are described. Of the 158 students and 88 preceptors who were exposed to the program, the authors received evaluations from 86 preceptors and 110 students. Students documented that they had screened and provided foot-care education to 321 diabetic patients. On average, students saved their preceptors 5-10 minutes each time they examined a diabetic patient's feet or provided foot-care education. The students said that the wide variety of preceptors' practices, the time constraints placed upon the preceptors, and the preceptors' own guidelines for the voluntary preceptorship all posed challenges to completing the preventive activities. The preceptors reported that preclinical students could play an important preventive role in their practices; however, to get optimum results from a preventive module, it may be important for students and preceptors to determine which topics are introduced. Using the preceptor's suggestions, the authors are developing a smoking-cessation module.

Analysis of Variance↗

PubMed2001

Automated multiplex assay system for simultaneous detection of hepatitis B virus DNA, hepatitis C virus RNA, and human immunodeficiency virus type 1 RNA.

We have developed an automated multiplex system for simultaneously screening hepatitis B virus (HBV), hepatitis C virus (HCV), and human immunodeficiency virus type 1 (HIV-1) in blood donations. The assay, designated AMPLINAT MPX HBV/HCV/HIV-1 Test (AMPLINAT MPX), consists of virus extraction and target sequence-specific probe capture on specimen preparation workstation GT-X (Roche Diagnostics K.K., Tokyo, Japan) and amplification and detection by TaqMan PCR on the ABI PRISM 7700 Analyzer (Perkin-Elmer Applied Biosystems, Foster City, Calif.). An internal control (IC) is incorporated in the assay to monitor the extraction, target amplification, and detection processes. The assay yields qualitative results without discrimination of the three targets. Detection limits (95% confidence interval) are 22 to 60 copies/ml for HBV, 61 to 112 IU/ml for HCV, and 33 to 66 copies/ml for HIV-1, using a specimen input volume of 0.2 ml. The AMPLINAT MPX assay detects a broad range of genotypes or subtypes for all three viruses and has a specificity of 99.6% for all three viruses with seronegative specimens. In an evaluation of seroconversion panels, the AMPLINAT MPX assay detects HBV infection an average of 24 days before the detection of HBsAg by enzyme immunoassay. HCV RNA was detected an average of 31 days before HCV antibody. HIV-1 RNA was detected an average of 14 days before HIV-1 antibody and an average of 9 days before p24 antigen. The Japanese Red Cross has been evaluating the AMPLINAT MPX system since October 1999. The clinical performance indicates that the AMPLINAT MPX system is robust, sensitive, and reproducible, with a high percentage of valid assay runs (96.8%), a low false-positive rate (0.34%), and a low IC failure rate (0.24%).

Blood Donors↗

PubMed2001

Digital optical imaging of green fluorescent proteins for tracking vascular gene expression: feasibility study in rabbit and human cell models.

PURPOSE: To investigate the feasibility of using a sensitive digital optical imaging technique to detect green fluorescent protein (GFP) expressed in rabbit vasculature and human arterial smooth muscle cells. MATERIALS AND METHODS: A GFP plasmid was transfected into human arterial smooth muscle cells to obtain a GFP-smooth muscle cell solution. This solution was imaged in cell phantoms by using a prototype digital optical imaging system. For in vivo validation, a GFP-lentivirus vector was transfected during surgery into the carotid arteries of two rabbits, and GFP-targeted vessels were harvested for digital optical imaging ex vivo. RESULTS: Optical imaging of cell phantoms resulted in a spatial resolution of 25 microm/pixel. Fluorescent signals were detected as diffusely distributed bright spots. At ex vivo optical imaging of arterial tissues, the average fluorescent signal was significantly higher (P <.05) in GFP-targeted tissues (mean +/- SD, 9,357.3 absolute units of density +/- 1,001.3) than in control tissues (5,633.7 absolute units of density +/- 985.2). Both fluorescence microscopic and immunohistochemical findings confirmed these differences between GFP-targeted and control vessels. CONCLUSION: The digital optical imaging system was sensitive to GFPs and may potentially provide an in vivo imaging tool to monitor and track vascular gene transfer and expression in experimental investigations.

Animals↗

PubMed2001

Multiple sclerosis: use of light-chain typing to assist diagnosis.

Although the presence of oligoclonal IgG with abnormal kappa/lambda light-chain ratio in multiple sclerosis (MS) has been known for many years, this finding has not been put to diagnostic use in most routine clinical laboratories. In a retrospective study we report differences in the oligoclonal banding patterns between multiple sclerosis and non-MS patients. We had sufficient cerebrospinal fluid (CSF) on 36 from 71 patients with oligoclonal bands for immunofixation for kappa and lambda light chains, and for free kappa and free lambda. Thirteen out of 14 patients with clinically confirmed MS had predominantly IgG (kappa) banding. In contrast, in seven out of eight patients with diagnoses other than MS the IgG was linked to both kappa and lambda light chains in approximately equal proportions. Nine out of 14 patients with probable/possible/suspected MS showed predominantly IgG (kappa) banding; five others in this group had both IgG (kappa) and IgG (lambda) and free lambda light chains. The finding of IgG (kappa) bands in CSF samples with oligoclonal bands supports a diagnosis of MS.

Humans↗

PubMed2001

High levels of transgene expression following transduction of long-term NOD/SCID-repopulating human cells with a modified lentiviral vector.

Both oncoretroviral and lentiviral vectors have been shown to transduce CD34(+) human hematopoietic stem cells (HSC) capable of establishing human hematopoiesis in nonobese diabetic/severe combined immunodeficiency (NOD/SCID) mice that support partially human hematopoiesis. We and others have reported that murine stem cell virus (MSCV)-based oncoretroviral vectors efficiently transduced HSC that had been cultured ex vivo for 4-7 days with cytokines, resulting in transgene expression in lymphoid and myeloid progenies of SCID-engrafting cells 4-8 weeks post-transplantation. Although lentiviral vectors have been demonstrated to transduce HSC under minimal ex vivo culture conditions, concerns exist regarding the level of transgene expression mediated by these vectors. We therefore evaluated a novel hybrid lentiviral vector (GIN-MU3), in which the U3 region of the HIV-1 long terminal repeat was replaced by the MSCV U3 region (MU3). Human cord blood CD34(+) cells were transduced with vesicular stomatitis virus G envelope protein-pseudotyped lentiviruses during a 48-hour culture period. After a total of 4 days in culture, transduced cells were transplanted into NOD/SCID mice to examine gene transfer and expression in engrafting human cells. Fifteen weeks post-transplantation, 37% +/- 12% of engrafted human cells expressed the green fluorescence protein (GFP) gene introduced by the lentiviral vector. High levels of GFP expression were observed in lymphoid, myeloid and erythroid progenies, and in engrafted human cells that retained the CD34(+) phenotype 15 weeks post-transplantation. This study provides evidence that lentiviral vectors transduced both short-term and long-term engrafting human cells, and mediated persistent transgene expression at high levels in multiple lineages of hematopoietic cells.

Animals↗

PubMed2001

Reversal of inhibition by the T7 concatemer junction sequence on expression from a downstream T7 promoter.

We have previously reported that placement of the phage T7 concatemer junction (CJ) just upstream of another gene on a plasmid in a T7 system proved to be inhibitory to expression of the downstream gene. We had hypothesized that the inhibition was a result of a readthrough transcript of the CJ element interacting with the translation start region of the downstream gene; also that in the absence of a T7 termination signal, transcription continued around the plasmid multiple times ("rolling circle" transcription), always juxtaposing the inhibitory CJ sequence proximal to the downstream gene mRNA. Two strong predictions were made from this model: 1) that introduction of a spacer sequence between the CJ element and the downstream gene should alleviate the inhibition, and 2) that reintroduction of a T7 transcription terminator should prevent rolling circle transcription, thereby reversing the inhibition by allowing some transcripts to be generated originating from the downstream promoter that did not contain the inhibitory CJ element upstream. We report here that both of these predictions have been fulfilled. However, the reversal of inhibition was only partial in the construct where the T7 terminator was reintroduced, indicating that there remains a residual inhibitory effect of the CJ element on expression of the downstream gene. A possible explanation is that the CJ element, acting as a pause site for transcription, blocks access to the downstream T7 promoter, thereby reducing transcription from that promoter. If this explanation is correct, steric hindrance of transcription starts resulting from an upstream RNA polymerase pause site may represent a previously unrecognized mechanism of transcriptional control.

Bacteriophage T7↗

PubMed2001

Cytokeratin 7 and cytokeratin 20 in primary urinary bladder carcinoma and matched lymph node metastasis.

BACKGROUND: -Cytokeratin 7 (CK7) and cytokeratin 20 (CK20) are 2 types of intermediate filament protein. Expression of CK7 is seen in the majority of primary urinary bladder carcinomas. CK20 is restricted to superficial and occasional intermediate cells of the normal urothelium of the bladder. Aberrant CK20 expression has been documented in urothelial carcinoma and has proved useful as an ancillary diagnostic aid for urinary bladder tumor. Our hypothesis is that the pattern of CK7 and CK20 expression in metastatic urothelial carcinoma duplicates the expression of the same markers in the primary tumors. Therefore, immunohistochemical staining of metastatic tumors for these 2 markers may be helpful for differential diagnosis in ambiguous metastatic tumor deposits. OBJECTIVE: -To determine the concordance of CK7 and CK20 expression in primary bladder urothelial carcinoma and the matched lymph node metastasis. DESIGN: -We studied 26 patients with lymph node metastases who underwent radical cystectomy and bilateral lymphadenectomy for bladder carcinoma. Immunohistochemical staining for CK7 and CK20 was performed on formalin-fixed paraffin-embedded tissues containing primary cancers and lymph node metastases. RESULTS: -In all cases, there was a concordant expression of CK20 in the primary cancer and its matched lymph node metastasis. Twelve cases (46%) showed positive CK20 immunoreactivity in the primary tumor and its matched lymph node metastases, whereas 14 cases (54%) were negative for CK20 in both the primary tumor and lymph node metastasis. All cases showed positive CK7 immunoreactivity in the primary cancers and matched lymph node metastases. CONCLUSIONS: -CK20 immunoreactivity is reliably observed in metastases from bladder cancer when the primary tumor expresses CK20.

Adult↗

PubMed2001

Conserved genetic findings in metastatic bladder cancer: a possible utility of allelic loss of chromosomes 9p21 and 17p13 in diagnosis.

CONTEXT: Molecular analysis of microsatellite alterations of biologically distinct tumor cell subpopulations from the same patient may aid in the determination of tumor origin and further our understanding of the genetic basis of cancer progression. DESIGN: The authors examined the pattern of allelic loss with polymorphic microsatellite markers on chromosome 9p21 (D9S161, D9S171, IFNA), regions of putative tumor suppressor gene p16, and on chromosome 17p13 (TP53), the p53 locus, in matched primary and metastatic bladder cancers from 9 patients. All patients underwent cystectomy for bladder cancer and had regional lymph node metastases at the time of surgery. Genomic DNA was prepared from primary cancers and matched synchronous lymph node metastases using a microdissection method. RESULTS: The overall frequency of allelic loss was 78% in primary cancer and 89% in paired metastatic cancer. The frequency of allelic loss in the primary cancer was 86% with D9S161, 67% with D9S171, 71% with IFNA, and 80% with TP53. The frequency of allelic loss in matched metastatic cancer was 100% with D9S161, 62% with D9S171, 71% with IFNA, and 80% with TP53. An identical pattern of allelic imbalance (allelic loss or retention) at multiple DNA loci was observed in matched primary and metastatic carcinoma in 8 (88%) cases. One case showed allelic loss in the metastasis, but not in the primary cancer. CONCLUSIONS: The pattern of allelic loss at chromosome 9p21 (p16) and 17p13 (p53) was generally maintained during cancer progression to metastasis, and identical allelic loss in primary cancer was conserved in paired metastatic carcinoma. These data suggest that these genetic changes may be useful in establishing a diagnosis and determining tumor origins in difficult cases.

Aged↗

PubMed2001

Elevated and altered expression of the multifunctional DNA base excision repair and redox enzyme Ape1/ref-1 in prostate cancer.

The DNA base excision repair pathway is responsible for the repair of cellular alkylation and oxidative DNA damage. A crucial step in the BER pathway involves the cleavage of baseless sites in DNA by an apurinic/apyrimidinic or baseless (AP) endonuclease (Ape1/ref-1), which is a multifunctional enzyme that acts not only as an AP endonuclease but also as a redox-modifying factor for a variety of transcription factors including Fos, Jun, paired box containing genes (PAX), nuclear factor-kappaB, hypoxia-inducible factor alpha (HIF-1alpha), HIF-like factor (HLF), p53, and others. The expression of Ape1/ref-1 in prostate has not been characterized previously. Ape1/ref-1 nuclear immunohistochemistry levels, scored for intensity as 1+, 2+, or 3+, were 91, 3, and 6% in benign hypertrophy (BPH), 0, 42, and 58% in prostatic intraepithelial neoplasia (PIN) and 3, 30, and 67% in prostate cancer, respectively, clearly showing an increase in Ape1/ref-1 nuclear staining in the PIN and cancer compared with BPH. Furthermore, the level of cytoplasmic staining of Ape1/ref-1 in cancer and PIN were elevated (42 and 36%, respectively) compared with BPH (5%). There was no correlation with prostate-specific antigen values or doubling times to Ape1/ref-1 levels. In conclusion, we have demonstrated that Ape1/ref-1 is dramatically elevated in prostate cancer, the level of staining of Ape1/ref-1 increases from low in BPH to intense in PIN and cancer, and there is an increase in the amount of Ape1/ref-1 in the cytoplasm of PIN and cancer compared with BPH. Given these results, we conclude that Ape1/ref-1 may be a diagnostic marker for early prostate cancer and play a role, through its repair, redox, or both functions, in the physiology of the early development of prostate cancer.

Biomarkers, Tumor↗

PubMed2001

[The sieving performance of a new polyethersulfone hollow fiber plasma fractionation membrane].

Plasma fractionation membrane is very important in double filtration plasmapheresis. We studied a new polyethersulfone hollow fiber membrane plasma fractionator and evaluated the effect of time, transmembrane pressure (TMP) and mean shear rate on the sieving coefficient (SC) during membrane plasma fractionation. The sieving coefficients of various proteins reached their maximum values at 40 min at the plasma flow rate QI = 30 ml/min and plasma filtrated flow rate QF = 20 ml/min. The QF increased with the increase of TMP, and the point of the intersection of the curve of the QF vs. TMP and the SC vs. TMP was regarded as the ideal condition for plasma fractionation. The plasma filtrated rate PFR = QF/QI = 0.6-0.7. The TMP changed with the change of the mean shear rate, and the mean shear rate had little effect on the SC. The data is of significance to the application of plasma fractionation membrane.

Membranes, Artificial↗

PubMed2001

Effect of sea anemone toxin anthopleurin-Q on sodium current in guinea pig ventricular myocytes.

AIM: To investigate the effects of a sea anemone toxin anthopleurin-Q (AP-Q) isolated from Anthopleura xanthogrammica on sodium current (INa) in isolated guinea pig ventricular myocytes. METHODS: Single myocytes were dissociated by enzymatic dissociation method. INa was recorded using whole-cell patch-clamp technique. RESULTS: AP-Q (3 - 300 nmol/L) increased INa in a concentration-dependent manner. The EC50 value for increasing INa was 104 nmol/L (95 % confidence range: 78 - 130 nmol/L). AP-Q 300 nmol/L shifted the I-V curve to the leftward, changed the membrane potential of half maximal activation to more negative potential from (-36.3 +/- 2.3) mV to (-43 +/- 3) mV (n = 6, P < 0.01) and changed the membrane potential of half maximal inactivation to more positive potential from (-75 +/- 6) mV to (-59 +/- 5) mV (n = 6, P < 0.01). AP-Q 300 nmol/L shortened the half-recovery time of INa from (114 +/- 36) ms to (17 +/- 2) ms (n = 6, P < 0.01). The fast inactivation time constant (tauf) of INa was markedly increased by AP-Q 300 nmol/L. CONCLUSION: AP-Q has a stimulating effect on I(Na) with slowing the inactivation course of INa.

Animals↗

PubMed2001

Anti-Fas antibody induces apoptosis in cultured human renal interstitial fibroblasts.

OBJECTIVE: To detect if Fas is expressed in human renal interstitial fibroblasts (hRIFs) and apoptosis of hRIFs can be induced by specific anti-Fas antibody. METHODS: hRIFs were cultured from isolated papillae of human kidney, and identified by morphologic examination, assay of antigenic components and culture in D-valine selective medium. Fas expression in normal hRIFs was detected by RT-PCR and immunocytochemistry staining. After hRIFs were incubated with interferon gamma (gamma-IFN 500 U/ml, 1000 U/ml, 1500 U/ml and 2000 U/ml, respectively) for 48 hours, Fas expression was determined by Northern blot, Western blot and flow cytometry. hRIFs pre-stimulated with gamma-IFN (500 U/ml, 48 hours) were incubated with anti-Fas antibody (IgM, 0.5 microgram/ml) for 12 hours. And apoptosis was identified by morphologic examination, DNA ladder assay and flow cytometry. RESULTS: The cultured hRIFs showed a shuttle-like shape and were positively stained by labeled anti-vimentin antibody but negatively stained by anti-epithelial membrane antibody. They could not grow in the D-valine selective medium and died partly in a week. Fas mRNA and protein were expressed in normal hRIFs and markedly upregulated by stimulation with gamma-IFN. Apoptosis in gamma-IFN pre-stimulated hRIFs was induced by anti-Fas antibody, showing cell nuclear shrinkage and condensation in morphologic feature, internucleosomal DNA fragmentation in DNA ladder assay and a pick of hypo-diploid nuclei by flow cytometry. CONCLUSION: Fas is normally expressed in hRIFs and can be markedly upregulated by gamma-IFN. Anti-Fas antibodies can induce apoptosis of hRIFs pre-stimulated with gamma-IFN.

Antibodies, Monoclonal↗

PubMed2001

[Microscopic identification of Rhodiola henryi].

OBJECTIVE: To study the microscipic characteristics of the rhizoma, root, stem, leaf and powder of Rhodiola henryi. METHOD: By microscopic observation. RESULTS: The brown substance was always found in the rhizoma and root of Rhodiola henryi. There was a fiber ring in the cambium region of the stem, and some fiber bundles surrounded the pholem. The epidemis cells of the leaf were different in size, and some were very large. Most stomata were anisocytic. The pollen grains were spherical or oblate, with irregularly reticular veins on the outer walls and three germ pore furrows. CONCLUSION: The above-mentioned characteristics provided a basis for the identification of Rhodiola henryi.

Microscopy↗