Functional dissection of the Autographa california nuclear polyhedrosis virus enhancer element hr5

The hr5 enhancer element of Autographa californica nuclear polyhedrosis virus stimulates transcription from baculovirus-delayed early promoters in the presence of the viral transactivator, IE1. Gel retardation analyses of interactions between a fragment of hr5 and extracts prepared from cells transfected with an IE1-encoding plasmid revealed the presence of three DNA-protein complexes. In order to better define the functional domains of the hr5 enhancer, we constructed a set of plasmids containing partial deletions in the enhancer element. These constructs were tested for both in vitro DNA binding activity and enhancer function in transient assays. The results indicated that the minimum sequence required for DNA-protein interactions was half of the conserved 24-bp palindrome that is contained within a 60-bp direct repeat (DR60). However, the minimum sequence required for enhancer function was a complete copy of DR60. Template challenge experiments indicated that IE1 bound with equal affinity with a complete or a half copy of DR60. The deletion analyses were confirmed by in vitro binding and transient expression assays with synthetic oligonucleotides.

Progressive serum IgE elevation in the B6C3F1 mouse following withdrawal of dietary vomitoxin (deoxynivalenol)

Vomitoxin (deoxynivalenol) is a fungal toxin that induces serum IgA hyperelevation, IgA autoantibodies, mesangial IgA deposition in mice upon dietary exposure. The capacity of dietary vomitoxin to similarly alter serum IgE was assessed in female B6C3F1 mice. Ingestion of 25 ppm vomitoxin in AIN-76A semipurified diet resulted in 2.7-, 4-, 5- and 2.3-fold increases in serum IgE relative to controls after 12, 16, 20, and 24 weeks of toxin feeding, respectively. When mice were fed 25 ppm vomitoxin for 8 weeks and continued on toxin-free diet, serum IgE levels were 2.4, 4, 4.9, and 2-fold that of controls at 12, 16, 20, and 24 weeks, respectively. IgE levels were not significantly different between treatment and withdrawal groups at Weeks 12-24. These results differed from those of serum IgA, which increased much earlier and only during toxin administration, and those of IgG, which was largely unaffected compared to controls. The results indicate that a defined period of vomitoxin ingestion can subsequently induce progressive dysregulation of IgE production in addition to previously described IgA-related pathologic effects.

Capsid assembly and involved function analysis of twelve core protein mutants of duck hepatitis B virus

The roles of different regions of the duck hepatitis B virus (DHBV) core protein on viral capsid assembly and related functions were examined. Twelve deletion and insertion mutations which covered 80% of the DHBV C open reading frame were constructed and expressed in Escherichia coli. The N-terminal region (amino acids 3 to 66) of DHBV core protein was important for its tertiary structure and function in E. coli. The expressed core mutants without this region apparently inhibited E. coli growth. The results of transmission electron microscopy of E. coli thin sections, capsid agarose gel, and sucrose gradient sedimentation demonstrated that a few DHBV core mutants with insertion in the N terminus and deletion in the C terminus retained the ability to form core-like particles in E. coli. However, other mutations in most of N-terminal and central regions strongly inhibited the self-assembly ability of DHBV core protein in E. coli. In addition, the mutant with a C-terminal region deletion (amino acids 181 to 228) lost most of the nucleic acid-binding activity of the DHBV core protein.

Transcriptional interactions of transforming growth-factor-β with pro-inflammatory cytokines

BACKGROUND

Inflammation and tissue injury are characterized by a massive infiltration of mononuclear cells. These pro-inflammatory cells, which are the precursors of an inflammatory response by the immune system, secrete a variety of cytokines and growth factors that alter the biosynthetic repertoire of the resident connective tissue cells. Specifically, expression of connective tissue matrix metalloproteinases, such as stromelysin and interstitial collagenase, is enhanced, together with the expression of chemoattractants for leukocytes, such as interleukin-8 (IL-8). These events lead to increased connective tissue degradation. We have examined the growth factor regulation of expression in cultured fibroblasts of the prototypic pro-inflammatory factors interstitial collagenase and IL-8.

RESULTS

We demonstrate that transforming growth factor-beta (TGF-beta) does not interfere with cytokine-induced IL-8 gene expression, nor does it affect the activity of NF-kappaB-driven promoters. In contrast, TGF-beta down-regulates collagenase gene expression through the induction of the jun-B proto-oncogene. Jun-B is a negative regulator of c-jun, which mediates cytokine activation of collagenase gene expression through its action as a component of the AP-1 transcription factor.

CONCLUSION

Our data suggest that TGF-beta may attenuate the deleterious events that occur in inflammation by preventing cytokine-induced extracellular matrix degradation, although it does not affect cytokine-induced recruitment of pro-inflammatory cells. Furthermore, our data suggest a potential therapeutic use for jun-B, which may be a candidate for gene therapy in disease states that are characterized by excessive connective tissue degradation.

Study on cytomegaloviral infection in acute leukemia patients by polymerase chain reaction

Polymerase chain reaction (PCR) and blot hybridization by probe labelled with digoxin were used to detect human cytomegalovirus (HCMV) DNA in 31 patients with acute leukemia and 20 controls. The positive rate detected by PCR in acute leukemia was 74.2% and 15.0% in the controls. The difference was statistically significant. The results suggest that acute leukemia patients are the high risk population with high infection rate of HCMV. The positive rate detected by digoxin method in acute leukemia was 58.1%. Six patients showed negative results by digoxin method, but positive by PCR. It was demonstrated that PCR was superior to digoxin method in sensitivity. Anti-HCMV IgM in serum of patients was detected at the same time, the positive rate was 16.1%. Only 6 of the 23 PCR positive patients showed positive anti-HCMV IgM. It suggests that the immune response is weak in acute leukemia patients and HCMV recently infected could not be excluded in the anti-HCMV IgM negative cases.

Detection of HCV infection by cPCR in patients with acute leukemia

HCV RNA and anti-HCV were detected respectively by complemented DNA polymerases chain reaction (cPCR) and ELISA in the sera of 28 acute leukemia patients with repeated blood transfusion and changes in liver function. HCV RNA positive rate was 78.6%. Anti-HCV positive rate was 60.7%. 25 subjects showed positive results in HCV RNA or anti-HCV, or in both of them. By combined assessment, the HCV infection rate was 89.3%. Acute leukemia patients were the high risk group of HCV infection because of the lowered immune function and repeated blood transfusion. By cPCR, HCV RNA can be detected earlier and the sensitivity is higher than by anti-HCV. So cPCR is a sensitive and specific method for early diagnosis of HCV infection. The combination of HCV RNA and anti-HCV detection methods may improve the diagnostic rate of HCV infection.

[Alternative combination chemotherapy with mitomycin C, vincristine, methotrexate, 5-fluorouracil, cis-platinum and adriamycin for adenocarcinoma of the lung]

Efficacy of an alternative combination chemotherapy with MMC, VCR, MTX, 5-FU, CDDP and ADM for adenocarcinoma of the lung is reported. Forty-one advanced cases (stage III: 9; IV: 32) were chosen for the chemotherapy. Two combination chemotherapies MMC + VCR + MTX + 5-FU + CDDP: MVMFP; MMC + VCR + MTX + 5-FU + ADM: MVMFA were repeated alternatively for 8 consecutive weeks with 2 interposed rest weeks, and this regimen was completed in 34 cases. All 41 cases were evaluable. Three and 26 cases achieved complete and partial responses, respectively. The response rate was 70.7%, and the median survival time was 13 months. The adverse effects of the chemotherapy observed were tolerable: alopecia (63.4%), gastrointestinal symptoms (14.5%), bone marrow toxicity (12.2%) and liver dysfunction (4.8%). These results indicate that our MVMFP/MVMFA alternative chemotherapy is quite effective for adenocarcinoma of the lung, comparable or superior to conventional chemotherapies.

In vitro vomitoxin exposure alters IgA and IgM secretion by CH12LX B cells. Relationship to proliferation and macromolecular synthesis

The CH12LX cell line was used as a clonal model to assess the direct effects of vomitoxin on IgM and IgA secretion in B cells. When vomitoxin was included in LPS-driven CH12LX B cell cultures, it had multiple effects on Ig secretion. Whereas vomitoxin doses of 115 and 120 ng/ml caused 50% inhibition (ID50) of IgA and IgM production, respectively, toxin concentrations in the 5 to 50 ng/ml range slightly stimulated IgA production. However, low vomitoxin doses did not induce switching of membrane IgM+ CH12LX B cells to membrane IgA+. Total cell number was unaffected at vomitoxin concentrations up to 100 ng/ml but dropped markedly at 200 ng/ml (ID50 = 170 ng/ml). Using the MTT reduction assay as another measure of viability and cell function, vomitoxin was also inhibitory (ID50 = 130 ng/ml). Both thymidine incorporation and leucine incorporation were also inhibited by the toxin with estimated ID50s being 120 and 110 ng/ml, respectively. The results indicate that although at high doses, vomitoxin inhibits proliferation, Ig secretion and DNA/protein synthesis in the clonal B cell model, the toxin marginally stimulated IgA secretion at lower doses.

Identification of a leucine-to-proline mutation in the keratin 5 gene in a family with the generalized Köbner type of epidermolysis bullosa simplex

We have previously reported linkage of a large Finnish family with the generalized (Köbner) type of epidermolysis bullosa simplex to chromosome 12q in the region containing the type II keratin gene cluster (Ryynänen et al., Am J Human Genet 49:978-984, 1991). In this study, we examined the possibility that keratin 5, the type II keratin expressed in the basal keratinocytes, harbors the mutation in this family. Nucleotide sequencing revealed a T-to-C transition within exon 7 of the keratin 5 gene in the affected individuals of the family, while the unaffected individuals showed no evidence of C. The presence of the T-to-C transition in the affected individuals was confirmed by restriction enzyme digestion analysis with NciI endonuclease, as well as with PCR amplification of specific alleles (PASA) analysis. The PASA analysis also indicated that the mutated allele was not found among the 100 alleles tested within the general Finnish population indicating that the mutated allele is not a common polymorphism. Furthermore, the mutated allele was not present in nine individuals representing three different EBS families of Finnish origin. The T-to-C transition at the nucleotide level resulted in substitution of a leucine by a proline at the amino acid level, and the substitution affected a leucine residue which was invariant among eight different human keratins in a highly conserved segment at the carboxy-terminal region of the keratin 5 polypeptide.(ABSTRACT TRUNCATED AT 250 WORDS)

Persistent dysregulation of IgA production and IgA nephropathy in the B6C3F1 mouse following withdrawal of dietary vomitoxin (deoxynivalenol)

To assess whether vomitoxin-induced dysregulation of IgA production and IgA nephropathy are reversible, relevant immunologic parameters were compared among experimental groups of B6C3F1 mice that were fed: (1) 25 ppm vomitoxin in AIN-76A semipurified diet for 24 weeks (treatment group), (2) 25 ppm vomitoxin for 8 weeks and then control diet for 16 weeks (withdrawal group), and (3) control diet for 24 weeks (control group). Levels of serum IgA and microhematuria index in the treatment group were elevated after 4 to 8 weeks and continued to increase with further vomitoxin exposure. IgA immune complexes and mesangial IgA deposition, as quantitated by interactive laser cytometer image analysis, were also increased with toxin exposure at Weeks 8, 16, and 24, whereas IgM, IgG, and complement component C3 deposition were unaffected or depressed. Serum IgA, microhematuria index, and mesangial IgA deposition in withdrawal mice remained elevated over those of the controls at Weeks 16 and 24 but were less than those of the treatment group. Cell recovery from Peyer's patches (PP) as well as the percentages of IgA+ and CD4+ cells in PP and spleen at Weeks 16 and 24 were greater in treatment mice than in controls, but only the percentage of IgA+ cells in PP was elevated in the withdrawal mice at these the same time points. When IgA secretion by unstimulated and LPS-stimulated splenic lymphocytes was used as the measure of systemic production, it was elevated in both treatment and withdrawal mice at Weeks 16 and 24. The results indicated that experimental dysregulation of IgA production and IgA nephropathy persisted up to 4 months after a discrete period of dietary vomitoxin exposure, but that the severity of these effects did not increase in a progressive fashion.

Baculovirus phosphoprotein pp31 is associated with virogenic stroma

The PstI K fragment of Autographa californica nuclear polyhedrosis virus (AcMNPV) encodes a protein with a molecular weight of 31,000. To define the role of this protein (pp31) in virus infection further, it was overexpressed in bacteria and used to produce polyclonal antiserum. Radioimmunoprecipitation analysis indicated that pp31 was synthesized during both the early and late phases of virus infection, consistent with previous analyses indicating that the gene was regulated by tandem early and late promoters. Metabolic labeling of cells with carrier-free phosphate indicated that pp31 was phosphorylated. Biochemical fractionation experiments showed that pp31 was localized in the nucleus and that it was more stably associated with the nucleus at later times of infection. Immunoblot analysis of subnuclear fractions indicated that pp31 was associated predominantly with the chromatin and nuclear matrix fractions. Immunofluorescence experiments confirmed that the pp31 protein was localized in the nucleus. Nuclear staining was relatively uniform early but was more centrally nuclear later in infection. Immunoelectron microscopy indicated that the pp31 protein was a component of virogenic stroma. Southwestern (DNA-protein) blot analysis demonstrated that pp31 is a DNA-binding protein. These findings suggest a possible role for pp31 in the virus life cycle.

[Protective action of phenytoin on cerebral ischemia in rats]

In order to study and modify the ischemic brain lesions, protecting the reversible damage of neurons, and limiting the ischemic damage both models of cerebral ischemia--focal cerebral ischemia induced by photochemically, and brain reperfusion after ligation of common carotid arteries bilateral in Wistar rats were used to investigate the protective effect of diphenylhydantoin (DPH) on cerebral ischemia. Two groups of rats received DPH 10 mg/kg and 30 mg/kg respectively were compared with those having received normal saline immediately after cerebral ischemia. The effects of DPH on the changes of EEG, biochemical marker and pathologic lesion in focal cerebral ischemia in rats were evaluated. The results showed that the degree of restoration of EEG in the group treated with DPH was better than in the group with normal saline, the content of water in ischemic cerebral tissue was decreased significantly (P < 0.05), the activity of Na-K-ATPase and antioxidant was increased significantly (P < 0.01, P < 0.05, respectively), and the percentage of necrotic neurons in periischemic area was decreased markedly (P < 0.001) in groups treated by DPH. The results suggest that there is a definite protective effect of DPH on cerebral ischemia.

Effects of various noise exposures on endocochlear potentials correlated with cochlear gross responses

Changes in endocochlear potentials (EP), cochlear microphonics (CM), and compound action potentials (CAP) with noise exposure were investigated in guinea pigs. The animals were anesthetized and immobilized and exposed to white noise at intensities ranging from 105 to 125 dB. The negative EP (N-EP) was induced by anoxia and was investigated during and after noise exposure. It was found that the general EP (G-EP, the sum of both positive EP (P-EP) and N-EP) increased remarkably during exposure to 115 dB noise but decreased during exposure to 125 dB noise. A smaller absolute value of N-EP was encountered only during exposure to 125 dB noise. The results shed light on the relationship between EP and CM, CAP changes, and the potential mechanism of EP change and its significance in noise-induced hearing loss.

[Relation between malondialdehyde generation by platelets and plasma thromboxane B2 and diagnostic classification by syndrome differentiation of traditional Chinese medicine in stroke during acute stage]

The malondialdehyde generation by platelets and TXB2 in poor platelet plasma were examined in 36 patients with stroke during acute stage. By CT examination 19 cases were diagnosed hemorrhagic, 17 cases ischemic; while by syndrome differentiation of TCM 16 cases belonged to Zhongzangfu(middle internal organs), 20 cases Zhongjingluo (middle channels). Results showed that the malondialdehyde generation by platelets was reduced, TXB2 in poor platelet plasma increased in patients, compared with those in the healthy controls. This finding was common in stroke during acute stage and was not related to diagnostic classes by either CT examination or syndrome differentiation of TCM. This study indicates that maintenance of normal platelet function may have significant implication in the prevention and treatment of cerebrovascular disease.

Quantitative assessment of mesangial immunoglobulin A (IgA) accumulation, elevated circulating IgA immune complexes, and hematuria during vomitoxin-induced IgA nephropathy

Extended dietary exposure to the trichothecene vomitoxin (deoxynivalenol), a naturally occurring fungal contaminant of cereal grains, induces elevated serum IgA and mesangial IgA accumulation in a manner similar to the human glomerulonephritis, IgA nephropathy. A 12-week feeding study was conducted in the B6C3F1 mouse to evaluate the effects of exposure to 25 ppm dietary vomitoxin over time on formation of IgA immune complexes (IgA-IC), hematuria, and mesangial deposition of IgA, IgG, IgM, and complement component C3. Both serum IgA and IgA-IC were significantly elevated in vomitoxin-exposed treatment groups compared to controls at weeks 4, 8, and 12, whereas serum IgG was unaffected. The incidence of hematuria was also significant in vomitoxin-exposed mice at weeks 4, 8, and 12. Quantitative immunofluorescence intensity measurements using interactive laser cytometer image analysis revealed significantly greater mesangial IgA accumulation in vomitoxin-fed mice compared to controls at weeks 4, 8, and 12. Although glomerular IgG and IgM deposition was present in both controls and treated mice, it was significantly lower in treated mice as compared to controls at week 12. Mesangial C3 deposition was not induced by vomitoxin feeding. Elevated IgA-IC, hematuria, and IgA mesangial accumulation occurring during exposure to vomitoxin mimicked human IgA nephropathy, whereas the absence of mesangial C3 represented a major difference between this toxin-induced immune dysregulation and the human disease.

Expression of an enhancer-binding protein in insect cells transfected with the Autographa californica nuclear polyhedrosis virus IE1 gene

The baculovirus Autographa californica nuclear polyhedrosis virus contains an element known as homologous region 5 (hr5) which is an enhancer of delayed-early viral gene expression. To begin to identify proteins that interact with hr5, DNA-protein interactions were analyzed by using extracts from Spodoptera frugiperda cells and a fragment of DNA containing the left half of the hr5 enhancer. This 252-bp DNA fragment contains two copies of a 30-bp direct repeat (DR30) and two copies of a 24-bp imperfect palindrome contained within a 60-bp direct repeat (DR60). Extracts prepared from normal S. frugiperda cells and cells transfected with pUC8 lacked enhancer-binding proteins. However, when gel shift assays were performed with extracts from cells transfected with a plasmid containing the viral trans-activator IE1 gene, two DNA-protein complexes were formed. Both DNA-protein complexes were specifically inhibited by competition with a 60-bp oligonucleotide corresponding to DR60 but not by competition with a different oligonucleotide corresponding to DR30. Formation of the two complexes did not appear to involve cooperative interactions between binding proteins. When DR60 was used as a probe, a single complex was formed. To measure the enhancer activity of DR60, a reporter plasmid was constructed that contained DR60 cloned upstream of the reporter chloramphenicol acetyltransferase gene under the control of the delayed-early 39K promoter. Transient expression analysis indicated that the oligonucleotide increased expression of this gene 300-fold over the level obtained in the absence of any enhancer sequences.

[A case of coronary artery bypass utilizing natural bifurcation of the right internal mammary artery]

A Forty five year old male with unstable angina due to multiple coronary artery stenosis underwent successful complete coronary revascularization utilizing the natural bifurcation of the right internal mammary artery. As this procedure has not been reported in detail previously in the literature and since the use of the natural bifurcation of the internal mammary artery was considered to be useful for the treatment of multiple coronary stenosis, this case was presented. Pre and post operative angiography is included.

[Study of lipid peroxidation in patients with chronic renal failure]

The levels of lipid peroxide in plasma and erythrocyte membrane, the contents of blood superoxide dismutase and copper, zinc, iron in plasma, and erythrocyte membrane fluidity were investigated in patients with chronic renal failure (CRF). In comparison with the health subjects the levels of lipid peroxide in plasma and erythrocyte membrane were significantly higher, the contents of blood superoxide dismutase were significantly lower in the patients with CRF. The plasma copper increased and plasma zinc decreased, but plasma iron remained unchanges in the patients of CRF. We found that rises of lipid peroxide in erythrocyte membrane were closely related to changes of microviscosity in them.

Effect of dietary administration of the trichothecene vomitoxin (deoxynivalenol) on IgA and IgG secretion by Peyer's patch and splenic lymphocytes

Prolonged dietary exposure of mice to the trichothecene vomitoxin induces abnormally high levels of serum IgA and kidney mesangial IgA accumulation in a manner that is highly analogous to the human glomerulonephritis IgA nephropathy. In this study, the capacity of Peyer's patch and splenic lymphocytes to produce IgA and IgG were compared in B6C3F1 mice that were fed diets with and without 25 ppm vomitoxin for up to 12 wk. Serum IgA increased 2-, 4- and 8-fold after 4, 8 and 12 wk, respectively, of vomitoxin exposure and it became the primary serum isotype, whereas serum IgG was unaffected. On termination of the experiment there were increased numbers of IgA-secreting cells in Peyer's patches after 8 wk of toxin exposure and in the spleen after 4, 8 and 12 wk of toxin exposure. There were also increased numbers of IgG-secreting cells in Peyer's patches on termination of the experiment at 4, 8 and 12 wk but no effects was observed in the spleen. Supernatant IgA and IgA-secreting cell numbers were also markedly elevated in lymphocyte cultures obtained from Peyer's patches and, to a lesser extent, from spleens of treated mice compared with controls. Based on output of treated mice relative to corresponding controls, IgA secretion was greatest in concanavalin-A-stimulated and unstimulated Peyer's patch cultures. Enhanced IgG secretion and IgG-secreting cells were also observed in mitogen-stimulated and unstimulated Peyer's patch lymphocyte cultures of treated relative to control mice, but differences in splenocyte cultures were negligible. Based on total Ig output, IgA production was 8- to 20-fold greater than IgG production in both control and treatment Peyer's patch cultures. In contrast, vomitoxin treatment caused a shift from primarily IgG production in lipopolysaccharide-stimulated spleen cultures to equivalent IgA production. These data provide in vitro evidence that ingestion of vomitoxin promotes terminal differentiation of IgA-secreting progenitors in the Peyer's patch and, to a lesser extent, in the spleen. These functional changes are consistent with the shift from IgG to IgA as the primary serum isotype.

[Prenatal sex identification with biotinylated human Y-specific DNA probe]

Using biotinylated human Y-specific DNA probe PHY2.1 and Cos 84, we carried out Southern and dot hybridization with human DNA from artificially aborted chorionic villi, and with DNA of peripheral lymphocytes from normal male and female. The results show that PHY2.1 may be applied in prenatal sex identification both by Southern and by dot hybridization but with Cos 84, only Southern hybridization could be used.

[Gluco, lipometabolic and trace elements alteration in bile with acute purulent cholangitis]

Analysis was made of the gluco, lipometabolic materials and trace elements in bile from patients. The specimens were collected in 11 cases with acute purulent cholangitis and 13 cases of selective biliary surgery at both inter-operational time, at which the bile were got by needling from the common bile duct, and post-operational time, at which the bile was obtained from T tube drainage bile before the extraction of the T tube or discharge from hospital. It was found that lactic acid and glucose markedly decreased and LDH activity increased in the cholangitis group at inter-operational time. Lifted hepatic glyconeogenesis and gluco-consumption and hepatic cellular damage were indicated. At the same time, most of the lipo-materials and lipase activity increased, as compared with the selective group, which showed that lipolysis was encouraged and that lipo-materials had flowed into the bile because of hepatic cellular damage. At the time of acute cholangitis, the Zn and Fe in bile markedly increased but the Cr in bile decreased, and the mechanism was not clear.