The E6 gene of human papillomavirus type 16 is sufficient for transformation of baby rat kidney cells in cotransfection with activated Ha-ras

The transforming potential of the E6 open reading frame (ORF) of the human papillomavirus type 16 was investigated with transformation assays in cotransfections with an activated ras gene. The E6 ORF driven by the heterologous CMV promoter could fully transform baby rat kidney cells (BRK) in cooperation with ras. The transformed cells grew in soft agar and induced tumors in athymic nude mice. The E6 ORF with mutations at the splicing donor site, which only encodes the full length E6 but not E6*s, could also fully transform the BRK cells at a similar efficiency as the wild-type E6 ORF, indicating that the full-length E6 was sufficient for the transformed phenotype.

[Corneal topography of patients with unsatisfactory visual acuity after epikeratophakia for aphakia]

Corneal topographic characteristics of 5 patients who obtained unsatisfactory vision after aphakic epikeratophakia, with at least nine months follow-up, were reported. All grafts were apparently decentered relative to visual axis. The contour of cornea showed highly irregular pattern of power distribution. These findings suggest that to mark visual axis before surgery, lathe corneal lenses carefully and do standard operation should be the basis of successful epikeratophakia.

Experimental revascularization of airway segments

A series of experiments was conducted to assess the possibility of revascularizing tracheal autografts with the rabbit lateral thoracic fascial flap. Injection studies and histological evaluation displayed optimal revascularization and reepithelialization of the graft after 2 weeks.

Role of IL-6 in activation of T cells for acquired cellular resistance to Listeria monocytogenes

We have previously shown that IL-6 is a major cytokine in the serum of mice infected with the intracellular bacterium Listeria monocytogenes, and that injection of rIL-6 before, but not after, infection promotes the recovery of mice from listeriosis. Here we demonstrate that IL-6 is required in the early stages of infection, in that injection of anti-IL-6 Ab 24 or 4 h before infection, but not 24 h after, led to a massive increase in bacterial numbers 4 or more days after infection. On the other hand, injection of rIL-6 before infection significantly suppressed bacterial numbers in the liver and spleen 3 to 4 days after infection and increased the production of IFN-gamma by in vitro cultured CD4+ and CD8+ T cells in response to specific Ag. rIL-6 did not protect SCID mice, which lack both T and B lymphocytes, against Listeria infection. The protective effect of rIL-6 was neutralized by the injection of Ab to IFN-gamma. We conclude that IL-6 plays an essential role in the activation of T cells to produce IFN-gamma, the cytokine that is central to acquired cellular resistance to intracellular bacteria.

Spontaneous transformation of rat ovarian surface epithelial cells results in well to poorly differentiated tumors with a parallel range of cytogenetic complexity

We previously used rat ovarian surface epithelial cells subjected to repetitious growth in vitro to provide experimental evidence in support of a role for incessant ovulation in the etiology of ovarian cancer. We have now initiated a series of 30 independent rat ovarian surface epithelial cell lines. This report describes findings in eight of the cell lines that, based on tumor formation in athymic mice, have undergone malignant transformation. Each of the tumors exhibited chromosomal alterations. Two well to moderately differential tumors had only one or two cytogenetic changes, and they had in common the presence of numerical gains. Each of five poorly differentiated tumors had complex karyotypes with three to eight clonal aberrations, prominent among them being unbalanced rearrangements and numerical losses. Several poorly differentiated tumors also had marker chromosomes, double minutes, or homogeneously staining regions. These findings demonstrate that the malignant tumors produced by spontaneously transformed rat ovarian surface epithelial cell lines range in degree of differentiation, which is paralleled by the cytogenetic complexity. Thus, this model system may fill an important void in future efforts to define the genetic basis of common epithelial tumors of the ovary and many features characteristic of these neoplasms.

Targeted nuclear antisense RNA mimics natural antisense-induced degradation of polyoma virus early RNA

We describe a general antisense strategy to inhibit target gene expression. The substitution of a cis-acting ribozyme for a polyadenylylation signal in an antisense expression vector results in the nuclear retention of RNAs and the efficient degradation of their targets. We demonstrate the utility of this system in polyoma virus, where early-strand RNA levels are downregulated in the nucleus by antisense late-strand counterparts. We show that mutations destabilizing these naturally occurring antisense transcripts lead to increased levels of early-strand RNAs. Furthermore, expression in trans of nuclear antisense transcripts lowers early-strand RNA levels and quantitatively mimics the natural regulation.

Topical CTC-96 accelerates wart growth in rabbits infected with cottontail rabbit papillomavirus

CTC-96, a cobalt containing complex, was tested as a putative topical therapeutic agent for the treatment of papillomavirus-induced tumors in our cottontail rabbit papillomavirus (CRPV)-rabbit model system. Following experimental infection of domestic rabbits with CRPV, CTC-96 was applied to infection sites twice daily, 5 days a week for a total of 8 weeks. Two levels of concentrations of aqueous CTC-96 were compared to placebo control-treated animals. With increasing dose of CTC-96 we observed tumors earlier, larger, and more often across eight infected sites on each animal.

Regulation of glucose transport and expression of GLUT3 transporters in human circulating mononuclear cells: studies in cells from insulin-dependent diabetic and nondiabetic individuals

We have previously shown that human circulating mononuclear cells (CMCs) respond to physiological concentrations of insulin with a rapid increase in glucose transport rate. The responding cells were found to be the monocytes, and cells derived from individuals with insulin-dependent diabetes mellitus (IDDM) had lower basal and insulin-stimulated glucose transport rates. Of interest, both cell types were found to express the GLUT1 but not the typical insulin-responsive GLUT4 transporter isoform. To further study the mechanisms responsible for stimulation of transport in these cells, we investigated (1) the response to insulin-like growth factor-I (IGF-I) and insulin-mimetic agents, and (2) the expression of other glucose transporter isoforms in CMCs of nondiabetic and IDDM individuals. The time course of insulin-stimulated glucose uptake in CMCs was rapid, reaching a plateau within 30 minutes. CMCs showed a dose-dependent and highly sensitive increase in glucose uptake to IGF-I (maximal response reached at 0.1 to 0.5 nmol/L IGF-I). The IGF-I dose-response curve was similar for CMCs of control and IDDM individuals, but both the basal and maximal response to IGF-I were lower in the diabetic group (P < .01). CMCs did not respond to vanadate, lithium, hydrogen peroxide, or short incubation (1 hour) with metformin, but glucose uptake increased in response to peroxides of vanadate and longer-duration (14 hours) metformin incubations. The glucose transporter isoforms of separated monocytes and lymphocytes were further investigated by Northern blotting of total RNA with a GLUT3-specific cDNA probe and by Western blotting of total membranes using GLUT3-specific antiserum.(ABSTRACT TRUNCATED AT 250 WORDS)

Experimental studies of the inhibitory effects of green tea catechin on mice large intestinal cancers induced by 1,2-dimethylhydrazine

Three hundred Kunming mice were randomly divided into six groups (half males and half females in each group). Group 1 was the positive control group, Groups 2, 3, 4 and 5 were experimental groups and Group 6 was used as the solvent control group. Mice in Groups 1-4 were injected with 1,2-dimethylhydrazine (1,2-DMH) (20 mg/kg body wt.) solution subcutaneously once a week from the 2nd week to the 20th week. From the 1st week to the 23rd week, mice in Groups 2, 3 and 4 were given catechin (1 mg/mouse), catechin (2 mg/mouse) and EGCG (2 mg/mouse), respectively, five times a week. Mice in Group 5 received only catechin (3 mg/mouse) five times a week from the 1st to the 23rd week. Mice in Group 6 were injected with an equal volume of 1 mmol EDTA solution subcutaneously once a week from the 2nd to the 20th week. At the end of the 27th week, all the mice were killed by cervical dislocation (Zhu, Q.H. and Zhu, Q.F. (1991) Laboratory Animal Science, 1st edition. The Junior Educational Publisher, Guangdong). Pathological examinations indicated that the incidence of large intestinal cancers occurring in Group 1 was 80%, significantly higher than that in Groups 2, 3 and 4 (p < 0.001). No tumors were found in Groups 5 and 6. This might suggest that green tea has preventive effects on large intestinal cancer induction in spite of the different doses of catechin. Immunohistochemistry studies showed that green tea catechins could enhance the activity of superoxide dismutase (SOD) in tissues.

Erythropoietin receptor mRNA expression in human endothelial cells

A previous report demonstrated that endothelial cells have erythropoietin receptors and respond to this hormone with enhanced proliferation. The present study demonstrates the existence of mRNA for erythropoietin receptor in human umbilical vein endothelial cells. We have reverse transcribed mRNA of endothelial cells and then used different PCR primers to amplify erythropoietin receptor target cDNA between exons 5 and 6 as well as 3-5 in addition to an internal standard DNA fragment. Correspondence of size as well as location of restriction endonuclease scission (Ava II) was used in comparing the amplified fragments of human endothelial cell erythropoietin receptor to those of two human erythroleukemia cell lines, OCIM1 and K562. No alpha- or gamma-globin mRNA was detected in endothelial cells but was readily demonstrable in OCIM1 cells. In addition, to determine whether the expression of human erythropoietin receptor on endothelial cells occurs in vivo, sections of umbilical cord and placenta were immunostained with antibodies against the extracellular portion of the receptor; the results showed strong positive staining of the vascular endothelium.

Controlled evaluation of copper-silver ionization in eradicating Legionella pneumophila from a hospital water distribution system

A controlled evaluation was made of the efficacy of copper-silver ionization in eradicating Legionella pneumophila from a hospital water supply. Copper-silver ionization units were installed on the hot water recirculation line of one building with water fixtures positive for Legionella species. Another building with the same water supply served as a control. Legionella species persisted within the system when copper and silver concentrations were < 0.3 and < 0.03 ppm, respectively. When copper and silver concentrations were > 0.4 and > 0.04 ppm, respectively, there was a significant decrease in Legionella species colonization, but the percentage of water fixtures positive for organisms was unchanged in the control building. When the ionization unit was inactivated, water fixtures continued to be free of Legionella species for 2 additional months. Copper-silver ionization can eradicate L. pneumophila in a water distribution system. The advantages of copper-silver ionization include relatively low cost, straightforward installation, easy maintenance, nontoxic by-products and the presence of a disinfecting residual.

Persistent cytomegalovirus infection of semen increases risk of AIDS

To evaluate if persistent cytomegalovirus (CMV) infection of semen in human immunodeficiency virus type 1 (HIV-1) antibody-positive men increases AIDS risk, serial cultures for CMV every 3-6 months were attempted four or more times from 164 men followed 3 years. CMV was never isolated from 58 men, in 1 or 2 samples from 54 (intermittently positive), and in > or = 3 samples from 52 (persistently positive). The Cox model was used to estimate relative hazards while controlling for CD4 cell number. The relative hazard was 2.9 for those intermittently and 4.0 for those persistently positive (P < .001). No Kaposi's sarcoma occurred in culture-negative men, 3 cases (5.6%) in intermittently positive men, and 4 cases (7.7%) in persistently positive men (P < .04). Persistent CMV in semen increases the hazard of AIDS in HIV-1 antibody-positive men, possibly by activating CD4 cells to produce HIV-1. Thus, control of CMV in HIV-1-infected persons may slow progression to AIDS.

Evidence of a selective free radical degradation of heparin, mediated by cupric ion

A free radical reaction generated by a mixture of Cu2+, hydrogen peroxide, and ascorbate causes an abrupt reduction in the anti Xa activity of heparin by about one-half, and in molecular weight by about one-third. The product, which has the characteristics of a "low molecular weight" heparin, differs little in constitution from the intact heparin, on the basis of NMR evidence that includes data for fractions of the polymers. The free radical attack appears to occur adjacent to, rather than directly upon, some residues of alpha-L-iduronic acid 2-sulfate. Substitution of the Cu2+ with Fe2+, results in a less selective alteration of the heparin. Dermatan sulfate undergoes more extensive degradation than heparin with the Cu-reagent, although its anti Xa a potency is less drastically reduced. Overall, the results are more consistent with a high degree of regioselectivity in the interaction between heparin and Cu2+ ion, than with a delocalized counter-ion interaction.

Quantitative evaluation of neuronal loss in the dorsal hippocampus in rats with long-term pilocarpine seizures

Systemic administration of the cholinergic agonist pilocarpine (350-400 mg/kg, i.p.) to rats induces acute behavioral and EEG status epilepticus followed by apparent complete neurological recovery. In rats receiving higher doses of pilocarpine (i.e., 380-400 mg/kg), recurrent seizures reappear 2-2.5 weeks later and continue to occur as long as the rats are kept alive. Stereological estimates of neurons in regions CA1, CA3 and the dentate granule cell layer in the dorsal hippocampus show a dose-dependent neuronal loss in the CA3 and CA1 subregions. The granule cell layer of the dentate gyrus is not affected. No progressive neuronal loss was observed in the regions studied after 3, 6 and 12 weeks during which the animals displayed spontaneous recurrent seizures. The temporal profile of the epileptic condition induced by pilocarpine and the resulting pattern of neuronal loss in the rat hippocampus are similar to those seen in many cases of human temporal lobe epilepsy. The neuronal loss is dose-dependent and primarily results from the acute pilocarpine-induced seizures as chronic seizures do not produce any measurable additional cell loss in the regions examined in the experimental model used in this study.

Clinical observation on osteoporosis treated with traditional kidney-tonifying medicaments

The method of scoring kidney deficiency symptoms and bone density was used to judge therapeutic efficacy on osteoporosis of traditional kidney-tonifying drugs. It was proved that the drugs not only improved clinical symptoms but also delayed the developmental process of this disorder. It also verified the correctness of the traditional theory that the kidney dominates the bone and generates the marrow.

A long-lasting vitamin C derivative, ascorbic acid 2-phosphate, increases myogenin gene expression and promotes differentiation in L6 muscle cells

Hormones and growth factors are important regulators of myogenic cell differentiation, but little is known about the effect of vitamins on muscle differentiation and development. We recently showed that L-ascorbic acid 2-phosphate, a stable form of vitamin C, increased the expression of muscle-specific glucose and ion transporters. We now show the effect of L-ascorbic acid 2-phosphate on the kinetics of myogenin expression at both the mRNA and protein levels during differentiation of L6 muscle cells. At the fully differentiated stage, control and L-ascorbic acid 2-phosphate treated cultures showed the same degree of cell fusion, but L-ascorbic acid 2-phosphate treated myotubes had a larger diameter than control myotubes. During L6 cell differentiation, the amount of both myogenin mRNA and protein reached a maximal level on day 4 before full myotube formation and then declined. L-ascorbic acid 2-phosphate treated cells expressed a higher amount of myogenin at both the mRNA and protein levels on day 4 compared to untreated cultures. Ethyl-3,4-dihydroxybenzoate, an inhibitor of collagen synthesis, prevented expression of myogenin mRNA and protein in both the control and L-ascorbic acid 2-phosphate treated cells. These results demonstrate that vitamin C can promote muscle differentiation likely through the increase of myogenin expression in myogenic cells, which may in turn regulate muscle differentiation in vivo.

Generation of selenium-containing abzyme by using chemical mutation

A new strategy for generating abzyme was developed. Glutathione peroxidase (GPX, EC 1.11.1.9) is one of the important members of antioxidation enzyme system; it catalyzes the reductions of a variety of hydroperoxides in presence of glutathione(GSH). We have first prepared the monoclonal antibody (McAb) with GSH binding sites, then incorporated GPX catalytic group selenocystein (SeCys) into the antibody combining sites by using chemical mutation. Thus the mutated antibody displays high GPX activity, which approaches the magnitude level of native GPX, exhibits the kinetic behavior similar to native GPX, and has some advantages over native GPX.

Semi-automatic quantitation of nucleolar organizer regions in non-Hodgkin's lymphomas

Nucleolar organizer regions may be useful in the diagnosis and classification of non-Hodgkin's lymphomas. In this study of 46 cases we applied morphometric analysis with quantitation of physical descriptors of the nuclear profile (area, perimeter) and both number and area of stained nucleolar organizers therein enclosed to a series of lymphomas and benign lymphoid infiltrates. While nuclear outlines were manually traced small organizer regions within the nuclear profiles were semi-automatically outlined by a thresholding procedure subjected to manual override. This results in determination of number, area and perimeter of organizer regions. Data were corrected for section thickness effects and a stereologic (three-dimensional) analysis was additionally performed. We found an increase in mean number and area of nucleolar organizers per nucleus in high grade lymphomas compared to benign infiltrates and lower grade lymphomas. Volume and thickness corrected data showed a decrease in organizer number with concomitant increase in organizer volume in the higher grade lymphomas. Multivariate analysis of the cases, previously classified histologically, showed that clear resolution could be obtained, on the basis of physical descriptors, both between as well as within groups of the three tumor grades.

Autoimmune response against the bullous pemphigoid 180 autoantigen

An immunodominant and potentially pathogenic epitope associated with bullous pemphigoid (BP) and herpes gestationis (HG) has recently been mapped by our laboratory to a noncollagenous stretch of the extracellular domain of the human BP180 antigen. This antigenic site, designated the MCW-1 epitope, has been shown to be recognized by the majority of BP and HG sera. Interestingly, the MCW-1 epitope is absent from the murine BP180 molecule, and therefore, human autoantibodies directed against this site could not be tested for pathogenicity using the conventional passive transfer mouse model. Alternatively, rabbit antibodies were prepared against recombinant forms of the human MCW-1 epitope and the murine NC16A domain and were tested for pathogenicity by passive transfer experiments. Neonatal mice injected with rabbit antimurine BP180 IgG developed a subepidermal blistering disease that closely mimicked BP and HG at the clinical, histological and immunological levels. Rabbit IgG specific for the human MCW-1 epitope was not pathogenic. These results suggest that the autoantibodies against the MCW-1 epitope of the human BP180 antigen found in BP and HG sera may be relevant in the pathogenesis of blister formation in these patients.

Localization of the highly polymorphic locus D19S120 to 19p13.3 by linkage

To obtain the regional localization of a dinucleotide repeat D19S120 (formerly designated LIPE) with 7 alleles and an observed heterozygosity of 73% (Levitt et al., 1992) we typed 40 CEPH families. Given the high heterozygosity and ease of typing, this marker represents a useful addition to the index map of chromosome 19.

Effect of temperature on kainic acid-induced seizures

The effects of body temperature on kainic acid-induced seizures and seizure-related brain damage were examined in rats. In rats with status epilepticus induced by intraperitoneal injection of 12 mg/kg of kainic acid (KA), ictal discharges were decreased by 50% when body temperature was lowered to 28 degrees C and nearly abolished when body temperature was lowered to 23 degrees C. In rats with mild hypothermia (28 degrees C), the duration of ictal discharges following KA injection was significantly lower than in rats with normal body temperature. No detectable hippocampal cell loss was observed in rats with hypothermia to 28 degrees C whereas gross cell loss in the hippocampus was observed in all rats with KA injection at normal body temperature. In contract to hypothermia, hyperthermia markedly aggravated the seizures and hippocampal damage induced by KA. Following elevation of body temperature to 42 degrees C KA (12 mg/kg) resulted in severe seizures and all rats died of tonic seizures within 2 h. Furthermore, 6 mg/kg of KA administered to rats with a body temperature of 41-42 degrees C, resulted in up to 4 h of continuous ictal discharges whereas no continuous ictal discharges were observed after the same injections in rats with normal body temperature. Histological examination in rats receiving 6 mg/kg of KA revealed severe cell loss in the hippocampus in rats with hyperthermia but not in rats with normal temperature. These results demonstrate that body temperature plays an important role in the control of epileptic seizures and seizure-related brain damage.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of nonionic detergents on P-glycoprotein drug binding and reversal of multidrug resistance

Multidrug-resistant cells are thought to maintain low intracellular cytotoxic drug concentration though the active efflux of drugs across the cell membrane. It is presently believed that P-glycoprotein mediates this energy-dependent drug efflux by interacting directly with various lipophilic compounds. In this report, we have used [3H]azidopine in a photoaffinity labeling assay to study the effect of detergents and denaturing agents on P-glycoprotein drug binding in intact cells. Nonionic detergents such as Triton X-100 or Nonidet P-40 at very low concentrations were found to completely abolish azidopine photolabeling to P-glycoprotein and are able to reverse the multidrug resistance phenotype. In contrast, high concentrations of the denaturing agent urea or the zwitterionic detergent 1-[(3-cholamidopropyl)dimethylamino]-1-propanesulfonate did not inhibit azidopine photolabeling to P-glycoprotein. A comparison between verapamil and Triton X-100 revealed that the latter was more effective in inhibiting azidopine photolabeling to P-glycoprotein while verapamil was more effective in potentiating [3H]vinblastine accumulation in drug-resistant cells. Drug transport studies showed that [3H]Triton X-100 accumulated in both drug-sensitive and -resistant cells, and its accumulation was not modulated by excess vinblastine, verapamil, or colchicine. Taken together, these findings suggest that low concentrations of Triton X-100 reverse the multidrug resistance phenotype by inhibiting P-glycoprotein drug binding. In addition, it is also suggested that the site(s) of P-glycoprotein drug binding is localized to sequences found within the lipid bilayer.

Naturally processed cytokine-derived peptide bound to HLA-class II molecules

Sequence analysis of HLA-class II (HLA-DR beta 1-1502 and 1104)-bound self-peptides from a transformed B cell line was performed. The sequences of naturally processed self-peptides bound to HLA-DR2 and DR5 were compared with protein and nucleic acid data bases for homology to known precursor proteins. Of the matches to known precursors, one peptide showed 100% homology to the third framework and CDR3 regions of Ig VH expressed by the line. Another peptide matched 100% to the human equivalent of macrophage inflammatory protein (MIP). A synthetic peptide corresponding to the naturally processed form of MIP (KPGVIFLTKRSRQV) was shown to inhibit Ag-specific HLA-DR beta 1*1104-restricted T cell proliferation. This indicates that the MIP peptide binds to HLA-DR beta 1*1104. The MIP peptide belongs to a set of peptides that showed uniform NH2-terminal processing. In this set, proline always occurred as the second residue followed by a basic lysine or arginine in position nine. This suggests that final NH2-terminal processing of peptides precedes their binding to MHC molecules. A distinct, second set of peptides showed ragged NH2-terminii, as has been reported for other naturally processed MHC-class II-bound self-peptides.

Naturally processed HLA class I bound peptides from c-myc-transfected cells reveal allele-specific motifs

Naturally processed peptides, bound to HLA-A2, A68, B40 molecules, were isolated from a c-myc transfected lymphoblastoid B cell lines for sequence analysis. Forty-three sequences of bound peptides could be grouped into three structural motifs. One of the peptide sequences obtained, SLLPAIVEL, was identical to a previously reported peptide bound to HLA-A2.1 and was used for grouping HLA-A2-bound peptides. A second motif, identical to that previously reported for HLA-A68-bound peptides, was also observed. A distinct third motif, consistent with the structure of the HLA-B40 "45 pocket," was observed. The peptides within this group contained glutamate in position 2, usually followed by a hydrophobic residue in positions 3 and 9. Within this motif group of peptides bound to MHC class I molecules, one peptide, HEETPPTTS, was 100% homologous to residues 243-251 of the c-myc protein.

Experimental tracheal tube created with vascularized fascia

An experimental fascial transferable bed was developed in the rabbit model. This tissue is reliable in bringing a viable mucosal graft inside the larynx. A vascular connective tissue sheet with full-thickness mucosa and autogenous cartilage for external support are needed. In this study a tracheal tube was preformed to study the use of autogenous cartilage as support for a circumferential lumen.

Magnetic resonance imaging (1H) and spectroscopy (1H, 31P) of growing chicken embryos

Nuclear magnetic resonance (NMR) imaging and spectroscopy techniques were used to observe in vivo anatomical and metabolite changes, respectively, in developing chicken embryos. Proton (1H) NMR images of the eggs revealed major changes in yolk shape from day 2 to day 6. Embryos were visible from day 6 to hatching, and good embryonic anatomical images were obtained. Two peaks were observed from 1H-NMR spectroscopy of fertilized eggs: one for lipid methylene protons, and one for water protons. Water peak to lipid peak ratios did not vary significantly (P > 0.05) from day 2 to day 21 of incubation. Localized 31P-NMR spectra of developing embryos were obtained with either a 31P surface coil or a double-tuned 31P/1H volume coil. The surface-coil method gave a greater signal to noise ratio by a factor of four. The 31P-NMR spectra indicated two peaks at day 2; these were attributed to phosphomonoesters and phosphodiesters. The three peaks characteristic of ATP appeared on day 11 and increased in size until hatching. From day 19, phosphocreatine was detectable. There appeared to be a good correlation between 31P-metabolite changes detected by in vivo 31P-NMR spectroscopy and literature values for biochemical analyses of developing chicken embryos. The advantage in using NMR imaging and spectroscopy techniques is that anatomical and metabolic changes can be obtained in vivo, non-invasively and repeatedly as an embryo develops. Key words: NMR, MRI, embryo, poultry

[Purification and characterization of lipoteichoic acid from Streptococcus Sobronus]

Lipoteichoic acid (LTA) is amphipathic molecule found in cell surface of gram-positive bacteria.Although there were some hypothese about adhesion of LTA,the role of LTA in bacterial pathogenicety is still unclear.For this reason,a seria studies of LTA were carried out.In this study LTA was extracted by hot aqueous phenol from Strptococcus Sobronus 6715 grown in tryptic soy both supplemented with 5% sucrose for 17 hours,and was purfied on gel filtration by Sepharose 6B,chloroform-methanol precipitation and chromtography on DEAE-Sephacel.The purified LTA was characterized by FT-IR and 1H-NMR with standard sample of LTA (Sigma Co) as control.The results showed that LTA contains alanine ester and glycosyl residues which take important role in the amphipathic molecule.

Further study on the magnesium-mediated change in physical state of phospholipid modulates mitochondrial F0-F1-ATPase activity

We have postulated that magnesium may play a role in altering the lipid fluidity of the bilayers, which would induce a change of conformation of the F0-ATPase portion (buried in the lipid core) of mitochondrial F0-F1-ATPase. Such change could be transmitted to the soluble F1 portion, resulting in higher enzymatic activity. The assumption was further supported by the results presented in the following: (1) A conformational difference for the F0-ATPase-containing proteoliposomes induced by the magnesium effect could be detected using a fluorescent probe acrylodan; (2) H(+)-translocation activity of F0-ATPase-incorporated proteoliposomes with magnesium, monitoring by fluorescence quenching of 9-aminoacridine or the bulk phase pH change, was higher than that without magnesium; (3) The magnesium effect on the reconstituted F0-F1-ATPase activity was greatly enhanced when the reconstitution was carried out in the presence of oligomycin sensitivity conferring protein (OSCP, a main component of the connecting link between the F1 and F0 sector of F0-F1-ATPase).

Insulin and glucose suppress hepatic glycogenolysis by distinct enzymatic mechanisms

Both insulin and hyperglycemia can effectively suppress hepatic glucose output (HGO). We examined whether insulin and hyperglycemia specifically suppress liver net glycogen breakdown in a rat model in which glycogen is the major source of HGO. We further examined whether insulin and hyperglycemia act by similar or distinct enzymatic mechanisms. HGO, the rate of net glycogen loss, and glycogen phosphorylase and synthase activities were measured in fed, anesthetized rats infused with saline or insulin (7 mU/min/kg) while either maintaining plasma glucose at basal (7.8 +/- 0.2 mmol/L, euglycemic clamp [EC]) or at 10 mmol/L above basal (18 +/- 0.4 mmol/L, hyperglycemic clamp [HC]). During the basal period, the rate of HGO in each group was comparable to the rate of net glycogen breakdown, averaging 76 +/- 9 and 75 +/- 5 mumol/min/kg, respectively. Thus glycogen breakdown appeared to be a major source of ongoing HGO. Over the last 60 minutes of the experimental period, the rate of glycogenolysis averaged 69 +/- 8 mumol/min/kg in saline-treated rats; this could account for about 80% of the total HGO. During both EC and HC studies, HGO was suppressed (5.5 +/- 3 and -3.6 +/- 10 mumol/min/kg, respectively; P < .001 for each). Net glycogen breakdown decreased by 50% in EC rats (P < .05) and ceased in HC rats (P < .001). Glycogen synthase was predominantly in the active form in all three experimental groups (87% +/- 2%, 89% +/- 2%, and 95% +/- 3% in saline, EC, and HC rats, respectively).(ABSTRACT TRUNCATED AT 250 WORDS)

Major histocompatibility complex-restricted recognition of autologous chronic lymphocytic leukemia by tumor-specific T cells

From the peripheral blood of a patient with chronic lymphocytic leukemia (CLL) we generated a T-cell line and clones which recognized autologous CLL. The line comprised T-cell clones which responded to the CLL as well as to autologous Epstein-Barr virus (EBV)-transformed B cells in an HLA-DR-restricted fashion. In addition, the line comprised clones which were CLL-specific and showed no reactivity against EBV-transformed B cells and against autologous peripheral blood mononuclear cells obtained during remission. The proliferative response of the CLL-specific T-cell clone was inhibited by monoclonal antibodies to HLA-DR11, the major histocompatibility complex (MHC)-restrictive element. These results indicate that the MHC class-II molecule of CLL binds a tumor-specific peptide which is recognized by autologous T cells in an MHC class-II-restricted fashion. Such a peptide may serve as a target for immunotherapy.

Naturally processed cytokine-derived peptide bound to HLA-class II molecules

Sequence analysis of HLA-class II (HLA-DR beta 1-1502 and 1104)-bound self-peptides from a transformed B cell line was performed. The sequences of naturally processed self-peptides bound to HLA-DR2 and DR5 were compared with protein and nucleic acid data bases for homology to known precursor proteins. Of the matches to known precursors, one peptide showed 100% homology to the third framework and CDR3 regions of Ig VH expressed by the line. Another peptide matched 100% to the human equivalent of macrophage inflammatory protein (MIP). A synthetic peptide corresponding to the naturally processed form of MIP (KPGVIFLTKRSRQV) was shown to inhibit Ag-specific HLA-DR beta 1*1104-restricted T cell proliferation. This indicates that the MIP peptide binds to HLA-DR beta 1*1104. The MIP peptide belongs to a set of peptides that showed uniform NH2-terminal processing. In this set, proline always occurred as the second residue followed by a basic lysine or arginine in position nine. This suggests that final NH2-terminal processing of peptides precedes their binding to MHC molecules. A distinct, second set of peptides showed ragged NH2-terminii, as has been reported for other naturally processed MHC-class II-bound self-peptides.

Selective sequestration of nitric oxide by subcellular components of vascular smooth muscle and platelets: relationship to nitric oxide stimulation of the soluble guanylyl cyclase

Sequestration of nitric oxide (NO) by subcellular fractions isolated from bovine pulmonary arterial medial layer (BPA) and rabbit platelets (RP) was studied utilizing a novel chemiluminescence--headspace gas technique. Sequestration in all fractions was similarly rapid (5 min) and remained constant for at least 30 min. When incubated with 108 pmol of NO, the BPA mitochondrial, microsomal, and nuclear fractions sequestered 22.8 +/- 1.9, 20.5 +/- 2.2 and 15.2 +/- 3.6% of the NO, respectively (n = 14). However, significantly more of the 108 pmol of NO, 36.8 +/- 2.8 and 32.9 +/- 3.6%, respectively, was sequestered by the BPA homogenate (about 2 mg protein/mL) and BPA cytosolic fraction (about 1 mg protein/mL) (n = 19). Also, RP cytosolic fraction (about 3 mg protein/mL) sequestered a greater amount of NO than any BPA fraction when incubated with 108 pmol of NO (83.0 +/- 1.0%; n = 3). Analysis of the binding data obtained for the BPA homogenate and cytosolic fraction was consistent with the existence of two binding sites, one site with a Kd of approximately 100 nM and another with a Kd of approximately 1 microM. Both the BPA homogenate fraction and the cytosolic fraction as well as the RP cytosolic fraction were shown to have soluble guanylyl cyclase activity. The nitrovasodilator sodium nitroprusside (SNP) caused a concentration-dependent increase in the activity of this enzyme in all these fractions. Maximum stimulations caused by 1 mM SNP in BPA homogenate fraction, BPA cytosolic fraction, and RP cytosolic fraction were equivalent to 2-, 4- and 3-fold increases in catalytic activity, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Characterization of skeletal muscle actin labeled with the triplet probe erythrosin-5-iodoacetamide

We have labeled rabbit skeletal muscle actin with the triplet probe erythrosin-5-iodoacetamide and characterized the labeled protein. Labeling decreased the critical concentration and lowered the intrinsic viscosity of F-actin filaments; labeled filaments were motile in an in vitro motility assay but were less effective than unlabeled F-actin in activating myosin S1 ATPase activity. In unpolymerized globular actin (G-actin), both the prompt and delayed luminescence were red-shifted from the spectra of the free dye in solution and the fluorescence anisotropy of the label was high (0.356); filament formation red shifted all excitation and emission spectra and increased the fluorescence anisotropy to 0.370. The erythrosin phosphorescence decay was at least biexponential in G-actin with an average lifetime of 99 microseconds while in F-actin the decay was approximately monoexponential with a lifetime of 278 microseconds. These results suggest that the erythrosin dye was bound at the interface between two actin monomers along the two-start helix. The steady-state phosphorescence anisotropy of F-actin was 0.087 at 20 degrees C and the anisotropy increased to approximately 0.16 in immobilized filaments. The phosphorescence anisotropy was also sensitive to binding the physiological ligands phalloidin, cytochalasin B and tropomyosin. This study lays a firm foundation for the use of this triplet probe to study the large-scale molecular dynamics of F-actin.

A novel method for detection of nitric oxide binding sites by using a chemiluminescence-headspace gas technique

Nitric oxide (NO) is important in many physiological, pharmacological, and pathological processes. According to current concepts, guanylyl cyclase is considered to be a receptor for NO in vascular and nonvascular smooth muscle and other tissues. Since there are no suitable radioisotopes of oxygen and nitrogen available for conventional radioligand-receptor binding studies for NO, a novel method was developed to identify NO binding site(s). A chemiluminescence-headspace gas assay was utilized to measure the sequestration of NO in biological systems, and this was used as an index of NO binding. In the present report, myoglobin (a hemoprotein, Mb) was used as a prototype macromolecule to develop the binding assay for subsequent application to studies of putative NO receptors. Solutions containing various concentrations of Mb were incubated with NO in sealed micro-Fernbach flasks at 37 degrees C in an argon atmosphere for 30 min; NO remaining in the headspace gas was analyzed by means of the chemiluminescence assay. The magnitude of NO sequestration was dependent on Mb concentration, and 5 nM Mb was the lowest Mb concentration for which NO sequestration was measurable. Application of the method to the measurement of NO sequestration by bovine serum albumin (BSA) and pulmonary artery medial layer homogenate (BPA-M) revealed that the lowest BSA concentration at which NO sequestration was measurable was 1.6 microM, which was 320 times greater than that for Mb. Applicability of the method to address the question of putative NO receptors was indicated by significant NO sequestration after incubation with 20% (w/v) homogenate of BPA-M, which is responsive to NO and putative NO prodrugs.

Naturally processed HLA class I bound peptides from c-myc-transfected cells reveal allele-specific motifs

Naturally processed peptides, bound to HLA-A2, A68, B40 molecules, were isolated from a c-myc transfected lymphoblastoid B cell lines for sequence analysis. Forty-three sequences of bound peptides could be grouped into three structural motifs. One of the peptide sequences obtained, SLLPAIVEL, was identical to a previously reported peptide bound to HLA-A2.1 and was used for grouping HLA-A2-bound peptides. A second motif, identical to that previously reported for HLA-A68-bound peptides, was also observed. A distinct third motif, consistent with the structure of the HLA-B40 "45 pocket," was observed. The peptides within this group contained glutamate in position 2, usually followed by a hydrophobic residue in positions 3 and 9. Within this motif group of peptides bound to MHC class I molecules, one peptide, HEETPPTTS, was 100% homologous to residues 243-251 of the c-myc protein.

RPII15 codes for the M(r) 15,000 subunit 9 of Drosophila melanogaster RNA polymerase II

The RPII15 gene product of Drosophila melanogaster, which has recently been identified by sequence comparison, possesses a high similarity to subunit 9 of yeast RNA polymerase II. Using the polymerase chain reaction the coding region of RPII15 was isolated from genomic DNA of adult flies. Sequence analysis shows four amino acid substitutions in comparison to the previously reported sequence. Antisera were generated against bacterially expressed RPII15 and were used for immunoblotting experiments with RNA polymerase II of Drosophila melanogaster. This analysis identified the M(r) 15,000 subunit 9 as gene product of RPII15.

Bullous pemphigoid and herpes gestationis autoantibodies recognize a common non-collagenous site on the BP180 ectodomain

Bullous pemphigoid (BP) and herpes gestationis (HG) are skin diseases characterized by subepidermal blisters and autoantibodies against two hemidesmosomal Ag, i.e., BP230 and BP180. Based on sequence analysis the BP180 Ag was predicted to be a transmembrane protein with a long extracellular collagenous domain. In the present investigation fusion proteins encompassing various segments of the BP180 Ag were expressed in a prokaryotic system and assayed by immunoblotting and immunoadsorption against a panel of BP, HG and control sera. One antigenic site, comprising 14 amino acids of the BP180 noncollagenous (NC) 16A domain, was shown to be recognized by 60% of BP sera and by 63% of HG sera tested. 73% (11/15) of BP sera and 100% (8/8) of HG sera reacted with at least one of three BP180 fusion proteins representing various portions of the NC16A domain. Immunoadsorption analysis identified this region of BP180 as an immunodominant site. Using an affinity purified rabbit antiserum raised against a recombinant form of BP180, this BP/HG autoantibody-reactive region was localized to the epidermal basal lamina immediately adjacent to the hemidesmosome. These findings confirmed the predicted type II transmembrane orientation of the BP180 Ag. Thus, the long, C-terminal collagenous domain of this basal keratinocyte protein projects into the basal lamina and may function as a site of interaction with an extracellular matrix component. It is proposed that autoantibodies directed against the well-defined antigenic site on the BP180 ectodomain may play an initiatory role in subepidermal blister formation in BP and HG patients.

Bullous pemphigoid and herpes gestationis autoantibodies recognize a common non-collagenous site on the BP180 ectodomain

Bullous pemphigoid (BP) and herpes gestationis (HG) are skin diseases characterized by subepidermal blisters and autoantibodies against two hemidesmosomal Ag, i.e., BP230 and BP180. Based on sequence analysis the BP180 Ag was predicted to be a transmembrane protein with a long extracellular collagenous domain. In the present investigation fusion proteins encompassing various segments of the BP180 Ag were expressed in a prokaryotic system and assayed by immunoblotting and immunoadsorption against a panel of BP, HG and control sera. One antigenic site, comprising 14 amino acids of the BP180 noncollagenous (NC) 16A domain, was shown to be recognized by 60% of BP sera and by 63% of HG sera tested. 73% (11/15) of BP sera and 100% (8/8) of HG sera reacted with at least one of three BP180 fusion proteins representing various portions of the NC16A domain. Immunoadsorption analysis identified this region of BP180 as an immunodominant site. Using an affinity purified rabbit antiserum raised against a recombinant form of BP180, this BP/HG autoantibody-reactive region was localized to the epidermal basal lamina immediately adjacent to the hemidesmosome. These findings confirmed the predicted type II transmembrane orientation of the BP180 Ag. Thus, the long, C-terminal collagenous domain of this basal keratinocyte protein projects into the basal lamina and may function as a site of interaction with an extracellular matrix component. It is proposed that autoantibodies directed against the well-defined antigenic site on the BP180 ectodomain may play an initiatory role in subepidermal blister formation in BP and HG patients.

A passive transfer model of the organ-specific autoimmune disease, bullous pemphigoid, using antibodies generated against the hemidesmosomal antigen, BP180

Subepidermal blistering associated with the human skin diseases bullous pemphigoid and herpes gestationis has been thought to be an IgG autoantibody-mediated process; however, previous attempts to demonstrate the pathogenicity of patient autoantibodies have been unsuccessful. An immunodominant and potentially pathogenic epitope associated with these blistering diseases has recently been mapped to the extracellular domain of a human epidermal antigen, BP180. Patient autoantibodies that react with this well-defined antigenic site failed to crossreact with the murine form of this autoantigen and thus could not be assayed for pathogenicity in a conventional passive transfer mouse model. As an alternative, rabbit polyclonal antibodies were generated against a segment of the murine BP180 protein homologous with the human BP180 autoantibody-reactive site and were passively transferred into neonatal BALB/c mice. The injected animals developed a subepidermal blistering disease that closely mimicked bullous pemphigoid and herpes gestationis at the clinical, histological, and immunological levels. Autoantibodies that recognize the human BP180 ectodomain are therefore likely to play an initiatory role in the pathogenesis of bullous pemphigoid and herpes gestationis.

Myelin formation by mouse glia in myelin-deficient rats treated with cyclosporine

Previous attempts to generate myelin in the myelin-deficient rat spinal cord by transplanting mouse glia were not successful. In order to determine whether this result was due to graft rejection or to interspecies mismatch of cellular or molecular components at the axoglial junction, we have repeated the experiment in cyclosporine-treated rats. Our results show that in the immunosuppressed hosts, foetal glial xenografts form an abundance of myelin within the dorsal columns at or near the injection site about two weeks after the operation. In some cases, myelination extends virtually across the entire width of the dorsal columns. Ultrastructurally, the myelin sheaths are normal in all respects, including the presence of the 'radial component'. The lateral edges of the myelin lamellae form typical paranodal axoglial junctions, some displaying periodic 'transverse bands'. We infer that previous mouse to rat xenograft failures reflect host immune response rather than mismatch of heterologous junctional components. We also compared foetal, early post-natal and adult xenografts. Foetal donor cells, containing an abundance of precursors but virtually no mature oligodendrocytes, are more effective than neonatal donor cells in forming myelin, and after adult grafts, we found no myelin formation. Thus, in xenografts, as in allografts, foetal precursor cells are far more suitable than glia from mature donors in generating significant amounts of myelin.

High-affinity binding of progesterone to the plasma membrane of Xenopus oocytes: characteristics of binding and hormonal and developmental control

Progesterone induces maturation of the amphibian oocyte through its action on the plasma membrane. However, whether or not this action requires high-affinity binding to a specific receptor is unclear. In this study, the binding activity of progesterone was characterized in plasma membranes from whole ovaries or defolliculated oocytes of Xenopus laevis. Membrane-bound, radiolabeled progesterone was isolated by filtration of membrane suspensions and quantified by liquid scintillation. The association of progesterone to membrane preparations reached equilibrium within 15 min. Progesterone binding activity was directly proportional to the sample concentration, was significantly reduced by trypsin digestion, and was pH-dependent and temperature-sensitive. Also, binding activity was observed in membrane preparations from whole ovaries and defolliculated oocytes but not in those from somatic cells, indicating that progesterone binding is restricted to the oocyte membrane. Scatchard analysis indicated a single class of high-affinity (average KD, 10(-9) M), low-capacity (average concentration, 10(-12) mol/mg protein) binding sites for progesterone in all oocyte membrane preparations tested. Progesterone binding activity was also detected in preparations from albino frog ovaries, indicating that the binding activity is not an artifact of melanin contamination. Competition studies showed the following order of affinities: progesterone > pregnenolone > 17 alpha, 20 beta, 21-trihydroxy-4-pregnen-3-one > 11-deoxycorticosterone > 17 alpha, 20 beta-dihydroxy-4-pregnen-3-one > 11-deoxycortisol > estradiol > R5020 > corticosterone > aldosterone > cortisol > androstenedione > ouabain.(ABSTRACT TRUNCATED AT 250 WORDS)

The role of glucose-6-phosphatase in the action of insulin on hepatic glucose production in the rat

It has been suggested that regulation of glucose-6-phosphatase by insulin plays a role in the suppression of hepatic glucose production during feeding. We used hepatic glucose production (measured with the D-[3-3H]glucose infusion method) as an indicator of substrate flux through glucose-6-phosphatase in vivo. Compared with saline controls, insulin (7 mU.min-1 x kg-1, euglycemic clamp) suppressed hepatic glucose production virtually completely in both fasted (32.4 +/- 2.4 vs. -6.1 +/- 14 mumol.min-1 x kg-1) and fed (64.6 +/- 6.4 vs. 5.5 +/- 5.2 mumol.min-1 x kg-1) rats. Whereas hepatic glucose production was totally suppressed, [glucose-6-phosphate] in liver cytosol declined by only 27 and 35% in fasted and fed rats, respectively. Addition of hyperglycemia (10 mM) to the insulin infusion likewise fully suppressed hepatic glucose production (26.9 +/- 1.4 vs. -9 +/- 10 mumol.min-1 x kg-1 and 80.8 +/- 10.1 vs. -3.6 +/- 12.6 mumol.min-1 x kg-1 in fasted and fed rats, respectively), but [glucose-6-phosphate] again declined only modestly (21 and 27% in fasted and fed rats, respectively). This disproportionate suppression of hepatic glucose production could not be explained by cooperative substrate effects inasmuch as microsomal glucose-6-phosphatase isolated from saline- and insulin-treated rats followed Michaelis-Menten kinetics (Hill coefficient approximated 1). Acute insulin treatment of fasted rats in vivo did not reproducibly inhibit glucose-6-phosphatase activity assayed subsequently in isolated microsomes incubated in the absence of insulin.(ABSTRACT TRUNCATED AT 250 WORDS)