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Biomedical subjects

K Wu

Publications and source records attributed to K Wu.

At least 181 records · Page 10Linked to original sources
PubMed1996

Effects of dietary n-3 fatty acid supplementation in men with weight loss associated with the acquired immune deficiency syndrome: Relation to indices of cytokine production.

Cytokines may be involved in weight loss and disturbances of metabolism associated with human immunodeficiency virus (HIV) infection. Dietary n-3 fatty acids reduce the production of interleukin-1 (IL-1) and tumor necrosis factor (TNF) by peripheral blood mononuclear cells (PBMC) in normal humans and prevent IL-1 and TNF anorexia in animals. Accordingly, we studied the nutritional and metabolic effects of a 10-week trial of dietary fish oil (MaxEPA 18 g/day) in men with weight loss due to acquired immune deficiency syndrome (AIDS). Twenty men were enrolled, and 16 completed the 10-week supplementation period. Prior weight loss was 13.7 +/- 1.8 kg(17.4 +/- 1.6% body weight, means +/- SE). Food intake, body composition, blood chemistries, serum cytokine concentrations, in vitro production of IL-1 and TNF by PBMC, and clinical course were followed. A subset of subjects (n=12) underwent stable isotope infusions to measure de novo hepatic lipogenesis (DNL), an in vivo metabolic index that is influenced by cytokine presence and has previously been found to be elevated in AIDS. An unsupplemented group of men with AIDS wasting (10.4 +/- 2.4 kg weight loss, 13.1 +/- 2.2% body weight) was monitored for 10 weeks as controls. Baseline food intake (2,395 +/- 177 kcal/day and 95.1 +/- 7.2 g protein/day), body weight, percent fat, and fat-free mass were unchanged over the 10-week supplementation period. Serum triglycerides were reduced in hypertriglyceridemic subjects, confirming compliance with fish oil supplementation and suggesting that their hypertriglyceridemia was at least in part due to overproduction. Serum TNF and IL-1 were undetectable before or after fish oil supplementation. Serum interferon alpha (IFN) was measurable but did not change. In vitro production of IL-1 and TNF by PBMC was markedly reduced both at baseline and after fish oil supplementation in this population, even in the presence of new AIDS complications, compared with normal controls. The metabolic measurement DNL fell and weight was gained (2.1 +/- 1.3 kg) in subjects who did not develop new AIDS-related complications, but further increases in DNL and further weight loss were observed in subjects who developed a new AIDS complication (p<0.05 for interaction between new complication and change in DNL). No changes in body weight, food intake, serum triglycerides, serum cytokines, or DNL were observed in the unsupplemented group. We conclude that fish oil is a weak anticytokine agent that is unable to overcome the metabolic and nutritional consequences of acute AIDS-related complications but may exert a clinical anticytokine effect in stable AIDS patients. Cytokine production by PBMC is not a useful or reliable marker of in vivo cytokine activity in AIDS patients with weight loss. In contrast, an integrative functional index that is sensitive to cytokine presence in tissues (hepatic DNL) correlated with clinical response. These findings are relevant to the design of future studies of more potent anticytokine agents, such as thalidomide.

Acquired Immunodeficiency Syndrome↗
PubMed1996

Characterization of the genomic structure of the mouse APLP1 gene.

Amyloid beta protein (beta A4), the major component of the core of amyloid plaques in Alzheimer disease, is derived from the transmembrane amyloid precursor proteins (APPs). Our recent studies showed that a murine member of the evolutionarily conserved APP family, amyloid precursor-like protein 1 (APLP1), is specifically localized to the cerebral cortex postsynaptic density and may thus participate in brain synaptic function. To investigate regulatory mechanisms of APLP1 synthesis at the genomic level, we isolated and characterized genomic clones containing the mouse APLP1 gene. Sequence analysis revealed a genomic structure consisting of 17 exons and a promoter region that is devoid of apparent TATA and CCAAT boxes. The 5' region contains putative binding sites for AP-1, heat-shock protein, and Sp1, suggesting that multiple elements are potentially involved in regulating transcription of the APLP1 gene.

Alzheimer Disease↗
PubMed1996

Defective chorioallantoic fusion in mid-gestation lethality of parthenogenone<-->tetraploid chimeras.

Previous studies of parthenogenetic embryos revealed severe perturbations of both embryonic and extraembryonic tissue lineages during postimplantation development. The majority of pure parthenogenetic concepti have no recognizable axis and exhibit preferential terminal differentiation of their trophectoderm and primitive endoderm. To further define the role of the extraembryonic lineages in parthenogenetic development, we provided them with zygote-derived extraembryonic tissues by aggregating them with fertilized tetraploid embryos. On Day 12 of combined in vitro and in vivo development, most of the embryos proper in these chimeras were entirely derived parthenogenetically, whereas their trophectoderm and primitive endoderm tissues were derived from the tetraploid component. No Igf2 expression was detected in the parthenogenetic embryo proper, indicating that imprinting was manifested in such chimeras. Typical development of the parthenogenetic embryo proper was markedly improved in comparison with pure parthenogenetic concepti, with such chimeras attaining an average of 23 somites (range, 10 to 35). However, most of the chimeras died abruptly at Day 13, and all were being resorbed at Day 14 of development. The gross normality of axial structures and organ development suggests that a major cause of failure of these chimeric parthenogenones to survive beyond mid-gestation was due to defective chorioallantoic fusion. Our results indicate that the severe perturbation of axial development seen in most pure parthenogenetic concepti is a secondary consequence of the effects of parthenogenesis on the trophectoderm and primitive endoderm lineages. Moreover, the mid-gestation death of parthenogenetic embryos proper despite the presence of zygote-derived tetraploid tissues implicates extraembryonic mesoderm in manifesting the effects of genomic imprinting.

Allantois↗
PubMed1996

Determining factors for the outcome of peripheral blood progenitor cells harvests.

This is a pilot retrospective study to investigate the factors that may affect the collection of peripheral blood progenitor cells (PBPC). Sixty-nine PBPC harvests in 18 cancer patients (median age 39.5; 8 males and 10 females) were performed during marrow recovery after chemotherapy and hematopoietic growth factors. Median number of nucleated cells (MNC) collected were 13.3 (range 2.3-44.5) x 10(9) per session. Median CFU-GM was 362 colonies (range 63-1,720) per 500,000 MNC. Neither sex, body weight, diagnosis, nor the number of days into leukapheresis was significantly associated with MNC and CFU-GM. Older patients tend to have higher CFU-GM in the PBPC harvests (P = .0437). Higher WBC on the day of harvest is significantly associated with higher yield of MNC after leukapheresis (P < .0001). Patients without any evidence of disease have significantly higher yield of MNC than those having local/distant metastases with or without marrow involvement (P = .0302 and .0446). For patients with metastatic disease, those with bone marrow involvement tend to have higher CFU-GM than those without bone marrow involvement although the difference is not statistically significant (P = .0559). Those patients who have received only one, or three and more chemotherapy regimens have a higher yield of MNC than those who have only two previous chemotherapy regimens (P = .036 and .0324). The mechanism of PBPC mobilization is also discussed. In view of the limited patient number in this study, the results should be confirmed by larger studies.

Adolescent↗
PubMed1996

Purification and characterization of recombinant mouse growth hormone binding protein produced in the baculovirus expression system.

Sf21 insect cells were infected with recombinant baculovirus containing cDNA for the entire coding region of the mouse growth hormone binding protein (mGHBP). Recombinant (r) mGHBP was expressed at a yield of 17.3 mg/liter/3 days. The molecular size (Mr) of the rmGHBP was approximately 33,000 as estimated by SDS-PAGE. Amino-terminal sequence analysis of the recombinant protein yielded two sequences: one identical to amino acids l- 15 and another corresponding to amino acids 14-21 of the GHR/GHBP. Western blot analysis revealed that this is the same Mr as that of one of the two major Mr forms of serum mGHBP. Deglycosylation of serum mGHBP and recombinant mGHBP caused a shift in the molecular size of both proteins to that expected after removal of all N-linked carbohydrates. Binding characteristics of the recombinant mGHBP to mouse growth hormone were similar to those for serum GHBP. Scatchard analysis showed an equilibrium association constant (Ka) for rmGHBP of 3.8 x 10(8) +/- 0.6 x 10(8) M(-1) (mean +/- SEM, n = 3) and Ka of 9.2 x 10(8) +/- 2.0 x 10(8) M(-1) (mean +/- SEM, n = 3) for the serum mGHBP. In conclusion, this expression system should allow a production of relatively large quantities of mGHBP suitable for physiological studies on the role of this protein.

Alternative Splicing↗
PubMed1996

Analysis of upregulated cellular genes in pseudorabies virus infection: use of mRNA differential display.

Virus infection usually alters the host cell and shuts off the synthesis of cellular macromolecules. In order to screen the upregulated cellular transcripts during pseudorabies virus (PRV) infection, we employed the mRNA differential display technique. The screen is based on positive selection at the mRNA level for genes expressed in normal cells but increased in corresponding PRV-infected cells. Over 14000 species of mRNA, isolated from mock-infected and PRV-infected Madin-Darby bovine kidney cell at 1 h post infection, were screened, and 40 candidate clones were recovered. Southern blot analysis revealed that 17 out of 40 candidate clones, were enhanced in PRV-infected cells. Partial DNA sequences demonstrated that 17 clones were distinct cellular genes, including those encoding the modulators of signal transduction (saposin, 14-3-3, adenylate kinase, adenylyl cyclase, protein kinase C-alpha), those encoding the components of translation (fau, ribosomal proteins S11, L31, L36), other cellular genes (peptidase, cyclin E, rch1, oligo-C-rich single-stranded nucleic acid binding protein, rap, arginyl-tRNA synthetase), and two unknown genes. Thus, this study identifies successfully the transcriptionally regulated cellular genes which are associated with PRV infection. Furthermore, this study provides support for the use of mRNA differential display as a method to rapidly isolate differentially expressed genes in virus infection.

Animals↗
PubMed1996

Nitric oxide increases calcium/calmodulin-dependent phosphorylation of proteins in the postsynaptic density of adult rat cerebral cortex.

Nitric oxide (NO) plays important roles in diverse processes, including neurotransmission in the peripheral and central nervous systems. Nitric oxide synthase (NOS), the enzyme that catalyzes formation of NO from L-arginine, is an intrinsic component of the postsynaptic density (PSD), a specialization of the postsynaptic membrane. This raises the possibility that NO may play a role in postsynaptic function. To begin defining postsynaptic actions of NO, we examined effects of NO on Ca2+/calmodulin-dependent phosphorylation (C/C-DP) of proteins in the cortical PSD of adult rat brain. Treatment of the PSD with sodium nitroprusside, a NO donor, caused a 4-fold increase in C/C-DP of the major PSD protein (mPSDp), relative to C/C treatment alone. Another NO donor, S,S'-dinitrosodithiol, elicited a 2-fold increase in C/C-DP of the mPSDp. Treatment of PSD fractions with L-arginine, a substrate for endogenous NOS, caused a 3-fold increase in C/C-DP activity. The competitive NOS inhibitor, N-L-arginine-methyl ester, decreased basal C/C-DP of cortical mPSDp by 50% and blocked the increase elicited by L-arginine. The inhibitor had no effect on cAMP-dependent phosphorylation, suggesting specificity of NO action on C/C-DP. Our observations indicate that NO enhances C/C-DP of PSD proteins. As C/C-DP inactivates NOS, our findings raise the possibility that NO effects on C/C-DP constitute a feedback mechanism for regulation of NOS activity.

Animals↗
PubMed1996

High cellular concentration of peripheral blood progenitor cells during cryopreservation adversely affects CFU-GM but not hematopoietic recovery.

The effects of bone marrow (BM) and peripheral blood progenitor (PBPC) concentration during cryopreservation on subsequent hematopoietic engraftment following high-dose chemotherapy were studied in 24 patients. Seventeen BM harvests and 71 PBPC collections were performed between July 1991 and June 1994. The PBPC were frozen at significantly higher cellular concentrations than the BM (medians of 243 x 10(6)/ml versus 73 x 10(6)/ml respectively, p = 0.0003). The recovery of committed progenitor cell colonies (CFU-GM) was significantly lower from PBPC frozen at concentrations above the median, compared with 116% from those frozen at concentrations below the median (p = 0.0467). This phenomenon was not seen in BM, which was generally frozen at a threefold lower concentrations. Despite the lower recovery of CFU-GM when PBPC were frozen at a higher concentration, the patients receiving these grafts achieved good hematopoietic recovery. The higher number of PBPC probably compensated for the loss, and the patients still received a substantial number of clonogenic hematopoietic precursors.

Adolescent↗
PubMed1996

Molecular cloning and photoperiod-regulated expression of gibberellin 20-oxidase from the long-day plant spinach.

Spinach (Spinacia oleracea L.) is a long-day (LD) rosette plant in which stem growth under LD conditions is mediated by gibberellins (GAs). Major control points in spinach are the later steps of sequential oxidation and elimination of C-20 of C20-GAs. Degenerate oligonucleotide primers were used to obtain a polymerase chain reaction product from spinach genomic DNA that has a high homology with GA 20-oxidase cDNAs from Cucurbita maxima L. and Arabidopsis thaliana Heynh. This polymerase chain reaction product was used as a probe to isolate a full-length cDNA clone with an open reading frame encoding a putative 43-kD protein of 374 amino acid residues. When this cDNA clone was expressed in Escherichia coli, the fusion protein catalyzed the biosynthetic sequence GA53-->GA44-->GA19-->GA20 and GA19-->GA17. This establishes that in spinach a single protein catalyzes the oxidation and elimination of C-20. Transfer of spinach plants from short day (SD) to LD conditions caused an increase in the level of all GAs of the early-13-hydroxylation pathway, except GA53, with GA20, GA1, and GA8 showing the largest increases. Northern blot analysis indicated that the level of GA 20-oxidase mRNA was higher in plants in LD than in SD conditions, with highest level of expression in the shoot tips and elongating stems. This expression pattern of GA 20-oxidase is consistent with the different levels of GA20, GA1, and GA8 found in spinach plants grown in SD and LD conditions.

Amino Acid Sequence↗
PubMed1996

Effect of matrix glycation on expression of type IV collagen, MMP-2, MMP-9 and TIMP-1 by human mesangial cells.

Human mesangial cells grown in either 5 or 25 mM glucose were cultured on type IV collagen which had been previously control-incubated or in vitro glycated. Northern blot analysis revealed that after 3-7 days in culture mesangial cells on glycated type IV collagen expressed approximately 25-200% more alpha 1 (IV), approximately 20-50% less matrix metalloproteinase 2 (MMP-2), and 65-75% more tissue inhibitor of metalloproteinase 1 (TIMP-1). Decreased immunoreactivity (approximately 30-40%) and collagenolytic activity (approximately 10-40%) corresponding to MMP-2 was also detected in media conditioned during the third day of culture on glycated type IV collagen. These effects on cell function were related to the extent of type IV collagen modification and were similar for cells cultured in 5 or 25mM glucose. Elevated glucose (25 vrs 5 mM) increased expression of alpha 1 (IV) mRNA (approximately 40-70%) and in conjunction with matrix glycation resulted in detectable levels of MMP-9 message by northern blot although collagenolytic activity corresponding to MMP-9 was not detectable by zymography. We conclude that glucose and matrix glycation may each alter mesangial cell function, perhaps leading to an imbalance in mesangial matrix synthesis and degradation which could contribute to mesangial expansion characteristic of diabetic renal disease.

Blotting, Northern↗
PubMed1996

[Relationship between disturbances of microcirculation and TNF during burn shock].

The changes in microcirculation and the level of plasma TNF in rat at the early stage of burn shock were measured, and the effects of Polygonum cuspidatum (PC) on above mentioned changes were observed. It was shown when the level of plasma TNF was increased, the number of adhesive leukocytes on venule wall was increased and the number of open capillaries were reduced significantly, and there were apparent aggregation of leukocytes and injury in lungs. The level of plasma TNF and the number of adhesive leukocytes were nearly normal, and the degree of aggregation of leukocytes and injury of lungs were attenuated by giving PC. The present study showed that the level of elevated plasma TNF in the early stage of burn shock was directly correlated with the adherence of leukocytes and the closing of capillaries. The administration of PC could apparently inhibit the increase of leukocytes, and at the meantime, attenuate the adherence of the neutrophils and injury of the lung. The results confirmed that the elevation of plasma TNF might be involved in the development of adherence of neutrophils and the disturbances of microcirculation in burn shock.

Animals↗
PubMed1996

Molecular cloning and characterization of human FGF8 alternative messenger RNA forms.

Three alternatively spliced mRNA isoforms of the human fibroblast growth factor-8 (FGF8) gene, expressed in a prostatic carcinoma cell line, have been isolated as cDNA clones and characterized by DNA sequencing. The clones, designated FGF8a, FGF8b, and FGF8e, differ from each other at the NH2-terminal region of the mature proteins and share extensive nucleotide sequence homology in the protein coding region to the corresponding mouse cDNA isoforms that were previously reported. FGF8a and FGF8b exhibit identical amino acid sequences to those of their murine counterparts. FGF8e displays partial sequence variation from the corresponding mouse clone only in the extra exon sequence found in this isoform in both species. There is extensive sequence diversity between FGF8 (human) and Fgf8 (murine) genes in the 3'-untranslated region of the mRNAs. Northern blot analyses revealed FGF8 mRNA expression only in fetal kidney tissue among the various fetal and adult human tissues tested. The reverse transcription-PCR amplification method, however, detected FGF8 mRNA expression in adult prostate, kidney, and testes (the tissues that were tested) and in all normal and tumor prostatic epithelial cell lines examined; although expression of both FGF8a and FGF8b was seen in kidney and testes, FGF8b appeared to be the predominantly expressed species in the prostatic tissue and cell lines analyzed by reverse transcription-PCR. To address the biological effect of specific isoform expression, NIH3T3 cells were transfected with a eukaryotic expression vector containing cDNA for FGF8a, FGF8b, or FGF8e. Consistent with previous reports on differences in the transforming potential of mouse FGF8 isoforms, human FGF8b was found to induce marked morphological transformation to NIH3T3 cells and strong tumorigenicity of the transfected cells in nude mice. Human FGF8a and FGF8e were moderately transforming in NIH3T3 cells, and the transfected cells were moderately tumorigenic in vivo. These results document the production of three alternatively spliced FGF8 mRNAs in human tissues and the transforming and tumorigenic potential of their protein products. Moreover, these data, combined with the tissue-specific expression of these isoforms, suggest that they may have different biological functions.

Alternative Splicing↗
PubMed1996

[The effect of ligustrazine and 764-3 on type I and type III collagen mRNA expression in fibroblasts].

The effect of ligustrazine and 764-3 on type I and type II collagen mRNA expression in cultured fibroblasts was studied. The results showed that ligustrazine at a final concentration of 30 micrograms/ml for 24 hours could inhibit type I and type II collagen mRNA expression, 764-3 at a final concentration of 15 micrograms/ml for 24 hours could stimulate type I collagen mRNA expression, but exerted no effect on type II collagen expression. The possible mechanism of 764-3 action was discussed.

Cells, Cultured↗
PubMed1996

[Detection of bcl-2/JH fusion gene in patients with non-Hodgkin's lymphoma by semi-nested polymerase chain reaction].

To study the incidence and clinical significance of bcl-2/JH fusion in 45 Chinese patients with non-Hodgkin's lymphoma, semi-nested polymerase chain reaction (PCR) was used to detect the fusion gene of non-Hodgkin's lymphoma. A total of 12 patients gave positive results, they include 9 of the 15 patients with follicular lymphoma and 3 of the 30 patients with diffuse B-cell lymphoma. The results were negative in 5 patients with reactive hyperplasia. The breakpoint was located within the major breakpoint region in 11 of the 12 patients, and the remaining patient had bcl-2 translocation in the minor cluster region. The results of the study show that bcl-2/JH fusion gene in non-Hodgkin's lymphomas is an important molecular biological marker and has a significant role in differentiating benign or malignant hyperplasia, determination of clonality, predicting prognosis and in the discovery of minor residual disease.

Diagnosis, Differential↗
PubMed1996

[Diagnosis and treatment of iatrogenic ureteral injury].

Diagnosis and treatment of 17 patients who sustained 20 iatrogenic ureteral injuries were analyzed. Primary operations in which ureteral injury occurred are almost gynecologic procedures and general surgery. Injuries were managed by ureteroureterostomy in four, ureteral stent in one, removal suture ligation and ureteral double J-catheter in one, ureteroneocystostomy in ten, psoas-hitch technique and ureteroneocystostomy in one, nephrectomy in two. All patients with appropriate repair were followed-up periods of three to five years. Renal function of these patients had optimal results. When ureteral injury occurs, B-US, IVU, cystoscopy, retrograde ureterography or infusion of dye may be useful. An appropriate repair should be chosen according to length and position of ureteral injuries. Reoperation was optimal in two to three weeks. Immediate recognition of accidental ureteral injury provides optimal results. Patients with unrecognized injuries had suboptimal results.

Adult↗