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J J Li

Publications and source records attributed to J J Li.

At least 127 records · Page 7Linked to original sources
PubMed1993

HIV-1 infection and modulation of cytokine and growth factor expression in Kaposi's sarcoma-derived cells in vitro.

OBJECTIVES: HIV-1 transcripts have been detected in AIDS-related Kaposi's sarcoma (KS) tissues within the factor XIIIa + dermal dendrocytes present in the tumor. Various cytokines and growth factors have been shown to influence the growth of KS-derived cells in vitro. HIV-1 preferentially infects CD4+ cells and has also been found to infect some CD4- cells in vitro. The susceptibility of cultured KS cells in vitro to infection with HIV-1 and the expression of interleukin (IL)-1 beta, IL-6 and basic fibroblast growth factor (bFGF) after exposure to HIV-1 was examined. METHODS: The susceptibility of two different KS-derived cell cultures to HIV-1 infection was examined by the expression of p24 antigen, detection of proviral sequence and electron microscopy. The expression of IL-1 beta, IL-6 and bFGF was detected by enzyme-linked immunosorbent assay and reverse transcriptase polymerase chain reaction. RESULTS: KS-derived cells can be infected by HIV-1 in vitro. Both KS-derived cells were found to express CD4 mRNA. The expression of IL-1 beta and IL-6 was increased, whereas the expression of bFGF was not stimulated after exposure of KS cells to HIV-1. CONCLUSION: These experiments describe the in vitro infection of KS-derived cells by HIV-1 and the expression of various cytokines and growth factor following infection. The increased production of cytokines observed following such infection may be involved in the pathogenesis of AIDS-related KS.

Acquired Immunodeficiency Syndrome↗
PubMed1993

Dual mechanisms for change in myocardial signal intensity by means of a single MR contrast medium: dependence on concentration and pulse sequence.

To determine whether gadodiamide injection can provide sufficient enhancement on both T1- and T2-weighted spin-echo magnetic resonance (MR) images of the heart and skeletal muscles, anesthetized rats were divided into five groups. Groups 1-3 received 0.1 (n = 9), 0.3 (n = 8), or 0.5 (n = 8) mmol/kg gadodiamide injection, respectively, and T1-weighted images were obtained. Groups 4 and 5 received 0.3 or 0.5 mmol/kg gadodiamide injection, respectively, and T2-weighted images were obtained. Gadolinium concentration was measured in myocardium by means of inductively coupled plasma-atomic emission spectroscopy. On T1-weighted images, the 0.1 and 0.3 mmol/kg doses produced a dose-dependent increase in myocardial signal intensity proportional to gadolinium concentration. A dose of 0.5 mmol/kg, which correlated with higher gadolinium concentration and did not further increase myocardial signal intensity, prolonged the imaging window. On T2-weighted images, the 0.3 mmol/kg dose caused a transient decrease in myocardial signal intensity; the 0.5 mmol/kg dose produced greater and persistent loss of signal intensity. In conclusion, the changes in signal intensity induced by gadodiamide injection depend on the dose, pulse sequence, and type of tissue.

Animals↗
PubMed1993

Expression of int-2 oncogene in Kaposi's sarcoma lesions.

Fibroblast growth factors (FGFs), such as basic FGF, have been implicated in the growth of Kaposi's sarcoma (KS) cells in vitro. In the evaluation of the expression of the various genes of the different members of the FGF family and their receptors in fresh KS tissue specimens, int-2 was found to be expressed in more than half of the KS tumors examined. Using reverse transcription PCR, the expression of int-2 was detected in 21 of 38 (55.2%) fresh KS biopsy specimens. In contrast, int-2 mRNA transcripts were not found in normal appearing skin from the same patients except in one sample which was obtained from an AIDS patient with disseminated KS lesions. Sequence data confirmed that the amplified sequences were derived from int-2 mRNA with proper splicing. In addition, 12 nucleic acid alterations were identified in eight out of nine KS tumor samples sequenced. Using immunohistochemical methods, int-2 protein was detected in some of the spindle-shaped tumor cells surrounding the abnormal endothelial-lined vascular slits histologically characteristic of KS. Int-2 specific immunostaining was shown to be present in both the nuclei and cytoplasm of these spindle cells but was more pronounced in the nuclei. Neither amplification nor gross rearrangement of the int-2 gene was detected in KS lesions by Southern blot analysis. These results suggest that the expression of int-2 may play a role in the pathogenesis KS by stimulating local angiogenesis and cell proliferation.

Acquired Immunodeficiency Syndrome↗
PubMed1993

Estrogen carcinogenesis in the hamster kidney: role of cytotoxicity and cell proliferation.

Both natural and synthetic estrogens are capable of inducing renal neoplasms in Syrian hamsters with an incidence approaching 100%. Neither the sequence of events nor the mechanisms involved in estrogen carcinogenesis in this model have been established. Results presented here indicate that estrogen induces renal tubular damage in the hamster kidney that is progressive and cumulative. Tubular injury was evident both as abnormal or lost microvilli, accumulation of cytoplasmic lipid droplets, vacuolization, and increases in secondary and tertiary lysosomes after 1.5 months of diethylstilbestrol (DES) treatment. Increasing tubular damage was evidence by the detachment of tubular cells, cell debris, and occluded renal tubular lumens. In an effort to repair proximal tubular damage in the hamster kidney elicited by estrogens, a 4.0-fold increase in proximal tubule BrdU labeling was evident at 4 months of DES or 17 beta-estradiol (E2) treatment and in earlier estrogen treatment periods (1-3 months). During this period, there was a significant increase in aneuploid cells in the hamster kidney, the near diploid frequency increased more than 6.0-fold, and the near tetraploid frequency increased at least 3.0-fold between 1.5 and 3.5 months of estrogen treatment. Based on these data, the early sequence of events leading to estrogen-induced renal neoplastic transformation in the hamster is presented.

Aneuploidy↗
PubMed1993

Cultured Kaposi's sarcoma cell lines express factor XIIIa, CD14, and VCAM-1, but not factor VIII or ELAM-1.

BACKGROUND AND DESIGN: Historically, the Kaposi's sarcoma (KS) tumor cell was generally thought to be derived from endothelial cells. However, by immunohistochemical staining of lesions, many spindle-shaped cells in KS express factor XIIIa, suggesting that they may be related to dermal dendrocytes, a perivascular cell of monocyte/macrophage lineage. To extend our observations on tissue sections of lesions, four different established KS-derived cell lines before and after cytokine exposure, as well as biopsy specimens of KS lesions, were studied for the expression of endothelial cell and monocyte/macrophage antigens. RESULTS: Multipassaged KS tumor cells grew predominantly as spindle-shaped cells. By immunohistochemical staining, all four KS-derived cell cultures were factor XIIIa and intercellular adhesion molecule 1 positive. Three KS-derived cell cultures were CD14 and vascular cell adhesion molecule 1 positive. Expression of factor XIIIa was upregulated by interferon gamma. By polymerase chain reaction (PCR) analysis, expression of CD4 mRNA was also detected in all four KS-derived cell cultures. Expression of these monocyte/macrophage markers (factor XIIIa, CD14, and vascular cell adhesion molecule 1) on KS in vitro was also detected on spindle cells of KS lesions in vivo. Endothelial leukocyte adhesion molecule 1 and factor VIII expression was not detected on KS-derived cells in vitro before or after exposure to interferon gamma or tumor necrosis factor alpha. While cultured KS cells strongly expressed smooth-muscle alpha-actin, no detection was observed on spindle-shaped cells in vivo. Conversely, while cultured KS cells were devoid of CD34, the tissue biopsy specimens contain strongly positive spindle-shaped cells. Our results demonstrate that while KS cell lines express one antigen shared by endothelial cells, ie, vascular cell adhesion molecule 1, they lack several other endothelial cell markers such as factor VIII and endothelial leukocyte adhesion molecule 1, either before or after cytokine activation. CONCLUSIONS: Kaposi's sarcoma cell lines express several antigens linking them to dermal dendrocytes such as factor XIIIa, CD4, and CD14.

Antigens, CD↗
PubMed1992

HPV-16-related DNA sequences in Kaposi's sarcoma.

In the USA, Kaposi's sarcoma associated with the acquired immunodeficiency syndrome (AIDS-KS) is ten times more common in homosexual or bisexual men than in heterosexual men with AIDS. One explanation for this finding is that AIDS-KS may be caused by an infectious agent. Because there is a high incidence of human papillomavirus (HPV) infection, especially HPV-16, in homosexual men, we have sought HPV DNA sequences in Kaposi's sarcoma. We used the polymerase chain reaction with a primer pair specific for the highly conserved E6 region of HPV-16 to detect HPV-16 homologous DNA fragments in tumour tissues from 97 patients with KS and in KS-derived cell cultures. HPV DNA sequences were found in 11 of 69 KS skin tumours from homosexual men with AIDS-KS, in 3 of 11 KS biopsy specimens from homosexual men who had no clinical or laboratory evidence of HIV-infection, and in 5 of 17 KS skin lesions from HIV-1-negative elderly men and women with classic KS. The same primer pair amplified HPV-16 homologous fragments from two different continuous cell cultures derived from pleural effusion fluid of patients with pulmonary AIDS-KS and two continuous cell cultures derived from KS skin lesions. The findings suggest that HPV-16-related DNA sequences are associated with different forms of KS and may have a role in the pathogenesis of this neoplasm.

Acquired Immunodeficiency Syndrome↗
PubMed1992

Relationship between thermal tolerance and protein degradation in temperature-sensitive mouse cells.

The induction of thermotolerance was studied in a temperature sensitive mouse cell line, ts85, and results were compared with those for the wild-type FM3A cells. At the nonpermissive temperature of 39 degrees C, ts85 cells are defective in the degradation of short-lived abnormal proteins, apparently because of loss of activity of a ubiquitin-activating enzyme. The failure of the ts85 cells to develop thermotolerance to 41-43 degrees C after incubation at the nonpermissive temperature of 39 degrees C correlated with the failure of the cells to degrade short-lived abnormal proteins at 39 degrees C. However, the failure of the ts85 cells to develop thermotolerance to 43 degrees C during incubation at 33 degrees C after either arsenite treatment or heating at 45.5 degrees C for 6 or 10 min did not correlate with protein degradation rates. Although the rate of degrading abnormal protein was reduced after heating at 45.5 degrees C for 10 min, the rates were normal after arsenite treatment or heating at 45.5 degrees C for 6 min. In addition, when protein synthesis was inhibited with cycloheximide both during incubation at 33 degrees C or 39 degrees C and during heating at 41-43 degrees C, resistance to heating was observed, but protein degradation rates at 39 degrees C or 43 degrees C were not altered by the cycloheximide treatment. Therefore, there is apparently no consistent relationship between rates of degrading abnormal proteins and the ability of cells to develop thermotolerance and resistance to heating in the presence of cycloheximide.

Acclimatization↗
PubMed1992

Metabolism of [4-14C]estrone in hamster and rat hepatic and renal microsomes: species-, sex- and age-specific differences.

The metabolism of [4-14C]estrone (E1) was examined in liver and kidney microsomes of adult castrated male and ovariectomized female hamsters and rats and in neonatal and immature hamster renal microsomes. In castrated male hamster liver microsomes, E1 was metabolized extensively to six major metabolites; 15 beta-hydroxyestrone, 7 alpha-hydroxyestrone, 6 alpha-hydroxyestrone, 6 beta-hydroxyestrone, 2-hydroxyestrone, and delta(9,11)-dehydroestrone, and a nonpolar fraction. Six minor metabolites of E1 were also detected. In contrast, kidney microsomes derived from castrated male hamsters metabolized E1 to mainly 17 beta-estradiol, 2- and 4-hydroxyestrone, 6 alpha-hydroxyestrone, 6 beta-hydroxyestrone and one monohydroxyestradiol metabolite. However, 16 alpha-hydroxyestrone was not detected. A variable, but low amount of estriol was also found. Interestingly, the quantity of 2-hydroxyestrone found in kidney microsomes of the hamster represented 26% of the total amount of metabolites formed, whereas in liver microsomes, only 9% of the overall metabolism resulted in the formation of 2-hydroxyestrone. The ability of kidney microsomes of female ovariectomized hamsters and two different rat strains to metabolize E1 was 5.9- and 9.4-fold lower, respectively, compared to renal microsomes of male castrated hamsters. The onset of oxidative metabolism in newborn hamster kidneys during development was also assessed. The results indicate that the oxidative metabolism of [14C]E1 in renal microsomes of newborn hamsters was 20-fold less than in kidney microsomes of adult hamsters. While catechol E1 metabolites were essentially negligible in hamster kidneys of these ages, it was evident that the conversion of E1 to estradiol via 17 beta-hydroxysteroid dehydrogenase resembles levels seen in the adult animals. Between the age of one and two months, the male hamster kidney exhibited the capacity to metabolize E1 at levels seen in fully mature adult hamsters.

Age Factors↗
PubMed1992

The absence of Tat sequences in tissues of HIV-negative patients with epidemic Kaposi's sarcoma.

OBJECTIVE: Tat, an essential regulatory protein of HIV, acts as a growth factor for Kaposi's sarcoma (KS)-derived cells in culture. We tested the hypothesis that HIV-negative epidemic KS patients who are also at high risk for HIV disease might have been infected with a defective HIV-1 virus that retained the ability to express Tat. METHODS: We evaluated the presence of Tat sequences in KS tissue and peripheral blood mononuclear cells (PBMC) of HIV-1-negative individuals with epidemic KS who had risk factors for HIV infection by polymerase chain reaction using specific primers for the Tat region of HIV-1. RESULTS: No evidence for the presence of Tat-1 sequences or for Tat-expressing defective HIV-1 virus was found. CONCLUSION: These results suggest that HIV-1 Tat does not play a role in the initiation of KS in HIV-1-negative individuals. Tat might play an indirect role in epidemic KS in HIV-infected patients.

Base Sequence↗
PubMed1992

Detection of human immunodeficiency virus type 1 (HIV-1) in urine cell pellets from HIV-1-seropositive individuals.

Fresh urine pellets from human immunodeficiency virus type 1 (HIV-1)-seropositive individuals were examined for the presence of the HIV-1 genomic sequence and gene products. By using the polymerase chain reaction technique, HIV-1 DNA proviral sequences were detected in 53 of 80 (66.25%) fresh urine pellets from HIV-1-seropositive individuals, while urine pellets from all 24 healthy heterosexual controls were negative. HIV-1 RNA in urine pellets was detected by reverse transcriptase polymerase chain reaction in 2 of 43 (4.7%) HIV-1-seropositive individuals. In addition, HIV-1 p24 core antigen was demonstrated in 3 of 80 urine pellets from HIV-1-seropositive individuals by enzyme-linked immunosorbent assay. Moreover, HIV-1 p24 core antigen and HIV-1 RNA were shown in the cellular component of urine pellets from HIV-1-seropositive individuals by immunohistochemical staining and in situ hybridization. These results indicate that HIV-1 can be present in urine pellets from HIV-1-infected individuals.

DNA, Viral↗
PubMed1992

Delivery by direct intrauterine transfer of gametes.

A nurse, 27, primary sterility for 5 years, had normal menstruation, normal size of uterus anterior. HSG: Rt. tube was not visible, Lt. tube slightly enlarged at ampulla. Ovaries were over-stimulated by clomiphene, HMG and hCG.8 ova were taken through vaginal aspiration under B-mode ultrasound scanning. Direct introduction of ova and washed sperms simultaneously into the uterus on Sept. 19, 1991 resulted in successful single pregnancy up to 36(+1) weeks. A 2 250 g normal baby boy was delivered on May 15, 1992 spontaneously. The base and prospect of this manoeuver are discussed with a reference to Craft's procedure.

Adult↗
PubMed1991

Purification and properties of two forms of ATP sulfurylase from Euglena.

Two forms of ATP sulfurylase have been purified to homogeneity from mitochondria (ATPSm) and cells (ATPSc) of Euglena gracilis Klebs var. bacillaris Cori (aplastidic mutant W10BSmL). Both forms are monomeric, ATPSc is 52.3 kDa and ATPSm is 55 kDa. The pI is 7.9 for ATPSc and 5.8 for ATPSm. Therefore, ATPSm binds to DEAE-cellulose at pH 7.4; ATPSc does not. After cleavage by CNBr, the two forms of ATP sulfurylase show different sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) patterns, suggesting that they differ in amino acid sequence. ATPSm is mainly associated with the mitochondrial membrane and ATPSc is mainly soluble in the cells. Both enzymes require similar conditions in the molybdolysis assay, but show different pH optima when sulfate is used as substrate. ATPSc is more sensitive to adenosine 5'-phosphosulfate (APS) inhibition than ATPSm in the SO2-4 incorporation reaction. In the reverse reaction, ATPSc requires much higher concentrations of PPi and MgCl2 to saturate the reaction than ATPSm. The data indicate that the two enzymes are quite distinct and may have different roles in cell metabolism.

Animals↗