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Biomedical subjects

Y Lu

Publications and source records attributed to Y Lu.

At least 937 records · Page 52Linked to original sources
PubMed1990

Growth of the penaeid shrimp virus infectious hypodermal and hematopoietic necrosis virus in a fish cell line.

An established fish cell line, epithelioma papillosum cyprini (EPC), originating from the carp (Cyprinus carpio) was found to be susceptible to the penaeid shrimp virus, infectious hypodermal and hematopoietic necrosis virus (IHHNV). This economically important pathogen of penaeid shrimp raised in mariculture has been previously limited to growth only in young post-larval shrimps. This is, to our knowledge, the first reported successful growth of the penaeid virus in a fish cell line; it promises to provide a sensitive and convenient cell culture system for the primary isolation and detection of IHHNV which will aid immensely the production of IHHNV-free penaeid shrimp stocks for mariculture. Of added significance is the replication of a crustacean virus in a fish cell line which has never before been reported. The use of this sensitive cell line will also greatly facilitate the characterization of the IHHN virus and other crustacean viruses.

Animals↗
PubMed1990

Differential oncogene amplification in tumor cells from a patient treated with cisplatin and 5-fluorouracil.

Peritoneal cells were derived from a patient (PK) with adenocarcinoma of the colon during the course of cisplatin/5-fluorouracil (5-FUra) treatment. Resistance to cisplatin and 5-FUra, characterized by a lack of response to chemotherapy and continued growth of the tumor, was concomitantly associated with a 2-4-fold increase in DNA copy number for dTMP synthase and dihydrofolate reductase. There was a corresponding amplification in DNA copy number of the c-myc (2X), H-ras (4X), and c-fos (15X) oncogenes. Cytogenetic studies revealed an iso (13q) chromosome, but failed to show any double minutes or homogeneously staining regions. In addition, drug-resistant tumor cells from PK and another patient (HG) displayed enhanced expression of dTMP synthase, c-fos and DNA polymerase beta when compared to normal colon tissue and the HCT8 human colon carcinoma cell line. These results suggest that elevated oncogene DNA and gene expression may be involved in the development of cisplatin resistance.

Adenocarcinoma↗
PubMed1990

Expression of chimeric human transferrin genes in transfected human tumor cell lines.

The iron-binding plasma protein transferrin (TF) is essential for supplying iron to cells and the prevention of iron toxicity. Our laboratory has cloned and characterized the human TF gene. Comparison of promoter regions of TF genes from human, chicken, and mouse reveals a strong nucleotide sequence conservation. This study demonstrates that 5' flanking regions of the TF gene are sufficient for directing expression of a heterologous gene in transgenic mice and transfected cells. For cell-specific expression, more than 150 base pairs appear to be required.

Animals↗
PubMed1990

[Inhibition of growth and metastases of lung carcinoma in C57BL/6 mice by Corynebacterium parvum and its antitumor mechanism].

Cocrynebacterium parvum (CP) was injected around the tumor and tumor cells were inoculated subcutaneously with activated peritoneal macrophages. The effects on the growth and metastases of Lewis lung carcinoma in C57BL/6 mice were observed. Experimental results indicated that CP had significant inhibitory effect on the tumor growth and lung metastases. The cytotoxic effects of activated peritoneal macrophages in mice on target tumor cells (L5178Y) in vitro were studied with the technique of 3H-TdR assay. The proliferation of tumor cells was markedly inhibited by the activated peritoneal macrophages of CP. Experiments showed that the antitumor mechanism of CP was the mediation via activated cytotoxic macrophages. These results indicated that CP is an effective immunostimulant. These findings will provide a scientific basis for the clinical treatment of the primary and metastatic lung carcinoma.

Adjuvants, Immunologic↗
PubMed1990

CT-guided transcutaneous fine-needle aspiration biopsy. A report of 350 cases.

CT-guided transcutaneous fine-needle aspiration biopsies were done in 350 patients. They involved the abdomen in 226 patients (liver 75, pancreatic and abdominal masses 51, kidney 96, adrenal gland 3, spleen 1), thorax 90, musculoskeletal system 32, and brain 2. The accuracy varied with different locations. The accuracy of liver biopsy was 94%, kidney 95.8%, pancreatic and abdominal masses 88.2%, thorax 90%, and musculoskeletal system 96.5%. The occurrence rate of complications was 2.3%. Pneumothorax occurred in 7 patients having thorax biopsy, and gastric perforation in one patient after abdominal biopsy. The proper selection of fine needles, the method and technique, the influential elements of the accuracy, and the application of CT-guided aspiration biopsy were detailed in this paper.

Adolescent↗
PubMed1990

Interactions between N-methyl-D-aspartate and CGS 19755 administered intramuscularly and intracerebroventricularly in pigeons.

Behavioral effects of N-methyl-D-aspartate (NMDA) and the competitive NMDA antagonist cis-4-phosphonomethyl-2-piperidine-carboxylic acid (CGS 19755) were studied in pigeons. NMDA decreased responding under a fixed-ratio schedule of food presentation and was 8000 times more potent administered intracerebroventricularly (i.c.v.) as compared to intramuscularly (i.m.). CGS 19755 was 870 times more potent in producing catalepsy when administered i.c.v.; however, the duration of catalepsy was similar by the two routes of administration. Administered i.m. CGS 19755 decreased response rates only at doses that also produced catalepsy; administered i.c.v. some doses of CGS 19755 decreased responding without producing other behavioral effects. Rate-decreasing effects of i.m. NMDA were attenuated by i.m. CGS 19755; however, when CGS 19755 was administered i.c.v., there was little or no antagonism of NMDA. Rate-decreasing effects of i.c.v. NMDA were not attenuated by i.m. or i.c.v. CGS 19755 up to doses that produced catalepsy or eliminated responding. The large difference in potency between i.m. and i.c.v. administration for NMDA and for CGS 19755, as well as the slower onset of catalepsy when CGS 19755 was administered i.m., suggests these compounds do not readily cross the blood-brain barrier when administered parenterally. The inability of CGS 19755 to attenuate the rate-decreasing effects of NMDA when CGS 19755 or NMDA was administered i.c.v. suggests NMDA might decrease responding by different mechanisms when administered i.m. or i.c.v. in pigeons. Together these results indicate antagonism of NMDA in this study, and perhaps in other studies, when both NMDA and CGS 19755 were administered parenterally, might result from a peripherally mediated interaction. Moreover, this agonist-antagonist interaction is not a simple, competitive antagonism.

Animals↗
PubMed1990

The T open reading frame of human immunodeficiency virus type 1.

Sequence analysis of multiple isolates of the human immunodeficiency virus type 1 (HIV-1) reveals the existence of a conserved open reading frame, designated T, that partially overlaps the tat, rev, and vpu coding sequences. Here we show that in vitro translation of RNA derived from this region of the viral genome yields a 17 kDa fusion protein, the result of a minus one frameshift event in the overlap between the tat and T open reading frames. It is also shown that messenger RNA species accumulate in HIV-1 infection from which the 17 kDa protein can be made. These observations suggest that ribosomal frameshift events may result in the biosynthesis of viral regulatory as well as viral structural proteins.

Amino Acid Sequence↗
PubMed1989

Isolation, purification and characterization of infectious hypodermal and hematopoietic necrosis virus (IHHNV) from penaeidshrimp.

A protocol was developed for the isolation and purification of the infectious hypodermal and hematopoietic necrosis virus (IHHNV) of penaeid shrimps. Cesium chloride-banded virus obtained from three sources of infected shrimps was found to have a buoyant density of 1.33 g/cm3. Also, electron microscopical studies employing negative stain revealed isometric particles having a size of 19 +/- 1 nm. Colorimetric analysis of its nucleic acid type indicated that these particles contain only RNA.

Animals↗
PubMed1989

The vascular microanatomy of skin territory of posterior forearm and its clinical application.

We have undertaken a microanatomical study of a new donor site--the posterior forearm territory--on 43 cadaver arms. Two axial arteries were found, and both the fasciocutaneous flap and the fascial flap could be elevated with the two arteries on the posterior forearm. The posterior forearm flap was transferred to the hand to repair deformities of the wrist, the first web space, the dorsal hand, and the metacarpophalangeal joints in eight cases. The result was very satisfactory. The posterior forearm flap is near the hand, easy to perform, and reliable. It is a one-stage operation and does not sacrifice a main artery. In this article we demonstrate our own ideas about flap extension, which is valuable for clinical application.

Adult↗
PubMed1989

Effects of long terminal repeat mutations on human immunodeficiency virus type 1 replication.

The effects of deletions within three functional regions of the long terminal repeat of human immunodeficiency virus type 1 upon the ability of the long terminal repeat to direct production of the chloramphenicol acetyltransferase gene product and upon the ability of viruses that carry the mutations to replicate in human cell lines was investigated. The results show that the enhancer and TATAA sequences were required for efficient virus replication. Deletion of the negative regulatory element (NRE) yielded a virus that replicated more rapidly than did an otherwise isogeneic NRE-positive virus. The suppressive effect of the NRE did not depend upon the negative regulatory gene (nef), as both NRE-positive and NRE-negative viruses were defective for nef. We conclude that factors specified by the cell interact with the NRE sequences to retard human immunodeficiency virus type 1 replication.

Genes, Viral↗
PubMed1989

[CT investigation of renal cystic masses].

This report presented 61 cases of renal cystic masses including renal parenchymal cyst 57 cases; parapelvic cyst 2; cystic hypernephroma 1 and calyceal diverticulum 1 case. All were confirmed by CT guided puncture and aspiration. The CT features of various renal cysts. complications and some special manifestations as well as differential diagnosis were discussed. Pertinent analysis of the CT features are necessary for correct diagnosis and proper management.

Adult↗