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Biomedical subjects

S Sun

Publications and source records attributed to S Sun.

At least 325 records · Page 18Linked to original sources
PubMed1991

[The inhibitory effect of a third generation retinoid, R8605, on protein kinase C activity in vitro].

R8605 is a newly synthesized compound of the third generation retinoids produced by the Institute of Materia Medica. It exhibited in vitro inhibitory effects on the diolein and TPA (12-O-tetradecanoylphorbol-13-acetate) induced activation of Protein Kinase C (PKC) from rat brain and also showed inhibitory effects on the calcium/phospholipid-independent phosphorylation of protamine by PKC. The IC50 values were 65, 70, 100/mumol/L respectively. It is suggested that the inhibition of PKC activity by R8605 is related to the inhibition of tumor promotion.

Animals↗
PubMed1991

[Clinical observation and analysis in age-related macular degeneration with one eye of wet form and the other of dry form].

Twenty two cases (44 eyes) of age-related macular degeneration with one eye of wet form and the other of dry form were included in this study. The range of the lesion was determined on magnified negative film of fluorescein angiography. In the dry group 72.7% eyes had normal FAZ and in the wet group 59.1% eyes revealed the lesion involving whole FAZ. The area of the lesion was measured by polar coordinates computational method, the mean area was 5.048mm2 in the wet form and 1.034mm2 in the dry form, there was statistically significant difference between the mean areas of the two groups (P < 0.01). The mean amplitude of photopic ERG b-wave was 101.74 mu v in the wet form and 126.35 mu v in the dry form. The morphological characteristics, the abnormalities of the visual function and possible changes in the two groups of this disease were discussed.

Age Factors↗
PubMed1991

[Differentiation between allergic rhinitis and vasomotor rhinitis. Light and electron microscopic studies].

The pathological changes of nasal mucosa from allergic rhinitis and vasomotor rhinitis were observed. The results showed that the general characteristic was vascular dilatation with increased permeability and glandular proliferation with increased secretory activity. The pathological difference between mucous membranes of allergic and vasomotor rhinitis were mainly cellular infiltration and degree of damage on vascular wall. In allergic rhinitis there were more eosinophils, basophils, neutrophils and some mast cells and plasma cells in nasal mucosa. Gap formation in capillary wall was found in allergic nasal mucosa, there were less cellular infiltration and no gap formation in vasomotor rhinitis.

Diagnosis, Differential↗
PubMed1991

[Distribution and significance of nasal glands].

The distribution of nasal glands in the respiratory region of nasal cavities was studied. Four types of glands were found, namely: mucous, serous, seromucous and mucoserous glands, and were divided into high density, middle density and low density regions. High density regions of serous glands were mainly scattered in anterior part of the nasal septum, middle meatus, middle-posterior part of middle turbinate and nasal vault. Mucous, seromucous and mucoserous glands were well-distributed in the entire respiratory region with a low density. The distribution of nasal glands in the respiratory region is closely related to the physiologic functions of the nose and provides a pathological foundation for some diseases as well.

Adult↗
PubMed1990

Targeting the E1 replication protein to the papillomavirus origin of replication by complex formation with the E2 transactivator.

The mechanism by which transcription factors stimulate DNA replication in eukaryotes is unknown. Bovine papillomavirus DNA synthesis requires the products of the viral E1 gene and the transcriptional activator protein encoded by the E2 gene. Experimental data showed that the 68-kilodalton (kD) E1 protein formed a complex with the 48-kD E2 transcription factor. This complex bound specifically to the viral origin of replication, which contains multiple binding sites for E2. Repressor proteins encoded by the E2 open reading frame failed to complex with E1 suggesting that the 162-amino acid region of E2 that participates in transactivation contained critical determinants for interaction with E1. The physical association between a replication protein and a transcription factor suggests that transcriptional activator proteins may function in targeting replication initiator proteins to their respective origins of replication.

Animals↗
PubMed1990

Molecular cloning of androgen receptors from divergent species with a polymerase chain reaction technique: complete cDNA sequence of the mouse androgen receptor and isolation of androgen receptor cDNA probes from dog, guinea pig and clawed frog.

We have cloned and sequenced 2.8 kilobases of cDNA encoding the mouse androgen receptor by RNA amplification with transcript sequencing. Sequence analysis predicts that this cDNA contains an open reading frame of 2697 nucleotides encoding a polypeptide of 899 amino acids. Androgen receptor cDNA probes of dog, guinea pig, and frog were also isolated and sequenced using consensus primers derived from human and rat androgen receptor cDNAs. Northern blot analysis with the species-specific probes revealed similarities in size between amphibian and mammalian mRNAs. These results demonstrate the utility of this technique in obtaining nucleic acid probes and sequence information of steroid receptors from different species. The sequence data and the Northern blot analysis of the receptors in different species demonstrate that the androgen receptor has been well-conserved during evolution.

Amino Acid Sequence↗
PubMed1990

Synovial chondromatosis with intracranial extension. A case report.

A case of unilateral synovial chondromatosis of the temporomandibular joint with intracranial extension is presented. Extracapsular extension of these lesions is rare, and few cases have previously been reported. The case presentation will also reflect the inadequacy of routine preoperative temporomandibular joint x-ray films to reflect the extent of the lesion. Despite the benign nature of the lesion, excision was done because of the clinical aggressive behavior.

Bone Diseases↗
PubMed1990

Identification of a 68-kilodalton nuclear ATP-binding phosphoprotein encoded by bovine papillomavirus type 1.

E1 is the largest open reading frame (ORF) of bovine papillomavirus type 1 (BPV-1) and is highly conserved among all papillomaviruses, maintaining its size, amino acid composition, and location in the viral genome with respect to other early genes. Multiple viral replication functions have been mapped to the E1 ORF of BPV-1, and evidence suggested that more than one protein was encoded by this ORF. We previously identified a small protein (M) whose gene consists of two exons, one encoded by the 5' end of the E1 ORF. We show here that a 68-kilodalton (kDa) phosphoprotein made from the E1 ORF can be detected in BPV-1-transformed cells, and we present evidence that this protein is encoded by sequences colinear with the entire E1 ORF. The full-length E1 protein immunoprecipitated from virally transformed cells and identified by sodium dodecyl sulfate-polyacrylamide gel electrophoresis comigrates with a protein expressed from a recombinant DNA construct capable of producing only the complete E1 protein. In addition, two different antisera directed against polypeptides encoded from either the 3' or the 5' end of the E1 ORF both recognize the full-length E1 product. A mutation converting the first methionine codon in the ORF to an isoleucine codon abolishes BPV-1 plasmid replication and E1 protein production. Consistent with the notion that this methionine codon is the start site for E1, a mutant with a termination codon placed after the splice donor at nucleotide 1235 in E1 produces a truncated protein with the molecular mass predicted from the primary sequence as well as the previously identified M protein. When visualized by immunostaining, the E1 protein expressed in COS cells is localized to the cell nucleus. A high degree of similarity exists between the BPV-1 E1 protein and polyomavirus and simian virus 40 large-T antigens in regions of the T antigens that bind ATP. We show by ATP affinity labeling that the E1 protein produced in COS cells binds ATP and that this activity is abolished by a point mutation which converts the codon for proline 434 to serine. Furthermore, this mutation renders the viral genome defective for DNA replication, suggesting that the ATP-binding activity of E1 is necessary for its putative role in viral DNA replication.(ABSTRACT TRUNCATED AT 400 WORDS)

Amino Acid Sequence↗
PubMed1990

[Pharmacological action of various processed Mylabris phalerata Pallas].

We have compared the acute toxicity, sub-acute toxicity and in vitro and in vivo anti-tumor action of the rude drug, stir-fried with rice, and alkali-processed drugs of Mylabris phalerata before and after removing the head, feet and wings. The results indicate that the toxicity of the processed drugs is lower than that of the rude ones; the toxicity becomes higher without head, feet, and wings; and the alkali-processing method is better than stir-frying with rice recorded in the pharmacopeia.

Animals↗
PubMed1990

[Clinical study and CT scanning in multiple sclerosis].

Twenty cases of multiple sclerosis were studied clinically and with CT scanning. Abnormal findings were seen on the CT scans in nine of the patients. A total of 46 focal lesions were diagnosed with clinical neurologic examination. The CT scans showed together 24 foci. On the CT scans there were 13 typical periventricular plaques which caused no evident clinical symptoms and signs in the course of the disease. Among ten patients observed with enhanced CT during the clinically acute periods, four showed evidence of demonstrable lesions. The correlation between the findings on the CT scans and the clinical manifestations discussed.

Adolescent↗
PubMed1989

Radioimmunolocation of hepatic and pulmonary metastasis of human colon adenocarcinoma.

We have established a large library of monoclonal antibodies against a human hepatoma cell line called FOCUS. One such monoclonal antibody (SF-25) detects a 125-kilodalton cell surface antigen found on FOCUS cells. As both the liver and the colon are of endodermal origin, we examined the possibility of expression in colon adenocarcinomas. This antigen was found in all 23 colon adenocarcinoma tissues surgically obtained but was absent in the adjacent normal mucosal counterpart as determined by a direct radioimmunohistologic technique. In the present study, we have established a model for human metastatic colon adenocarcinoma using the LS 180 cell line. Athymic mice were further immunosuppressed by intravenous injection of anti-NK cell antibodies (antiasialo GM1). After 24 h, mice were injected with LS 180 cells either via the tail vein or into the spleen followed by splenectomy. Macroscopic pulmonary and lymphatic metastasis developed within 2-3 wk after injection of cells and 9 of 10 mice died with advanced metastatic disease 2-3 wk later. In addition, macroscopic hepatic metastases were evident in 4 of 5 mice 3-4 wk after intrasplenic injection. Both hepatic as well as pulmonary and lymphatic tumor spread was localized by nuclear imaging with 125I-SF-25. Furthermore, micrometastases were detected by autoradiography 5-10 days later. Monoclonal antibody SF-25 is a potential candidate for tumor localization and the experimental metastatic colon cancer animal model may be useful for treatment evaluation of monoclonal antibody SF-25 either alone or in combination with other monoclonal antibodies when conjugated to radionucleotides and chemotherapeutic agents.

Adenocarcinoma↗
PubMed1988

Mature liver stages of cloned Plasmodium falciparum share epitopes with proteins from sporozoites and asexual blood stages.

The liver merozoites of malaria parasites are of paramount importance, as they initiate the parasite invasion of red blood cells and start the cycle associated with the clinical features of malaria. Investigating liver merozoite antigen is difficult because of the lack of a rodent model of human malaria. In addition, only a low proportion of cells are obtained in vivo, the parasites from Cebus and Aotus monkeys are immature, and in-vitro experiments with liver cells are often confounded by contamination with the natural mosquito flora copurified with the sporozoites used for seeding the liver cultures. In our study, mature liver schizonts were shown to possess many of the antigenic determinants recognized by MoAbs and sera specific for defined sporozoite and blood-stage antigens. We employed an immunofluorescence procedure based on evaluating parasites in cryosections prepared from infected chimpanzee liver. Sufficient numbers of sectioned parasites were evaluated with each antibody to assure the reproducibility of the results, and the fixation procedure used was sufficiently non-destructive to parasite antigens so that clear differences between reactions of specific antibodies and negative controls were observed. Our evidence for sharing of epitopes by liver merozoites and sporozoites or by liver merozoites and asexual blood-stage parasites raises the possibility that immune responses elicited against sporozoites or asexual stage antigens being considered as vaccine candidates may also act against this important, little-studied stage of the parasite.

Animals↗
PubMed1988

Carpal tunnel syndrome in Rochester, Minnesota, 1961 to 1980.

The incidence of carpal tunnel syndrome in the population of Rochester, Minnesota, from 1961 through 1980 was determined by use of the medical records-linkage system of the Rochester Epidemiology Program Project at the Mayo Clinic; 1,016 patients (1,600 affected hands) were identified. Incidence (cases per 100,000 person-years) was 99 (crude) overall, whereas the age-adjusted rates were 52 for the men, 149 for the women, and 105 for both sexes combined. Age-adjusted incidence rates increased from 88 during the 1961 to 1965 quinquennium to 125 during the 1976 to 1980 quinquennium; these rates probably reflect better recognition rather than a true increase in incidence rates. Age-specific rates generally increased with age in men, whereas in women a peak was reached in the 45 to 54 age group.

Adolescent↗
PubMed1986

Amino acid sequence of a unique neuronal protein: rat olfactory marker protein.

A neuron-specific protein, the olfactory marker protein (OMP), has been sequenced. This was achieved by gas phase sequencing of peptides isolated by HPLC following chemical and enzymatic cleavages of the intact rat protein. The amino terminus of the intact protein is acetylated. This has been determined by fast atom bombardment mass spectrometry of the amino terminal dodecapeptide isolated following BrCN cleavage of the OMP. Comparison of the sequence reported here with over 3000 protein sequences stored in the NBRF protein data base indicates no significant homology with any previously sequenced protein. This, coupled with the occurrence of OMP only in mature olfactory neurons of many vertebrate species, suggests that this protein has a olfactory neurons of many vertebrate species, suggests that this protein has a unique function in the metabolism of these neurons.

Acetylation↗
PubMed1986

Muscle creatine content in rats given repeated large doses of nicotinamide: effects of dietary methionine, choline, carnitine, and other supplements.

Rats fed a 12% casein diet without added choline were chronically injected with pharmacologic doses of nicotinamide (NAM) for 18 to 28 d in three experiments. In addition to fatty livers and lower weight gains, the creatine content of heart and skeletal muscle was lower in NAM-treated than in control saline-injected rats. Dietary supplements of methionine prevented these alterations, and choline, depending on the level of supplementation, also had some similar effects. No consistent responses could be demonstrated by supplements of carnitine, histidine or folic acid plus vitamin B-12.

Animals↗
PubMed1984

Some species of human leukocyte interferon are glycosylated.

The carbohydrate content of all of the species of human leukocyte interferon (IFN-alpha) which have been derived from patients with chronic myelogeneous leukemia (CML) and purified to homogeneity has now been determined. Amino sugar content was measured by high-performance liquid chromatography and fluorescamine detection of acid hydrolysates of each sample. Two species showed significant amounts of glucosamine. Most of the purified species of leukocyte interferon from a myeloblast cell line were also tested, and two species were found to contain sugar residues. These forms also differed from the CML interferons in that they revealed the presence of greater amounts of galactosamine. The apparent lack of carbohydrate in some of the higher-molecular-weight species of interferon implicated factors other than glycosylation in the molecular weight differences. The results indicate that some species of IFN-alpha are glycosylated to various degrees.

Amino Sugars↗