Structural requirements for major histocompatibility complex class II invariant chain endocytosis and lysosomal targeting

The invariant chain (Ii) targets newly synthesized major histocompatibility complex class II complexes to a lysosome-like compartment. Previously, we demonstrated that both the cytoplasmic tail (CT) and transmembrane (TM) domains of Ii were sufficient for this targeting and that the CT contains two di-leucine signals, 3DQRDLI8 and 12EQLPML17 (Odorizzi, C. G., Trowbridge, I. S., Xue, L., Hopkins, C. R., Davis, C. D., and Collawn, J. F. (1994) J. Cell Biol. 126, 317-330). In the present study, we examined the relationship between signals required for endocytosis and those required for lysosomal targeting by analyzing Ii-transferrin receptor chimeras in quantitative transport assays. Analysis of the Ii CT signals indicates that although 3DQRDLI8 is necessary and sufficient for endocytosis, either di-leucine signal is sufficient for lysosomal targeting. Deletions between the two signals reduced endocytosis without affecting lysosomal targeting. Transplantation of the DQRDLI sequence in place of the EQLPML signal produced a chimera that trafficked normally, suggesting that this di-leucine sequence coded for an independent structural motif. Structure-function analysis of the Ii TM region showed that when Ii TM residues 11-19 and 20-29 were individually substituted for the corresponding regions in the wild-type transferrin receptor, lysosomal targeting was dramatically enhanced, whereas endocytosis remained unchanged. Our results therefore demonstrate that the structural requirements for Ii endocytosis and lysosomal targeting are different.

Anti-p53 antibodies in patients with Barrett's esophagus or esophageal carcinoma can predate cancer diagnosis

BACKGROUND & AIMS

We previously discovered anti-p53 antibodies predating a cancer diagnosis in subjects at increased risk for liver, lung, breast, and prostate cancer. Recently, we reported a significant correlation (P < 0.017) between p53 antibodies and p53 mutations in patients with late-stage esophageal carcinoma. Because others have reported p53 mutations and overexpression of p53 protein in Barrett's esophagus, we studied p53 antibodies in plasma of 88 serially endoscoped patients: 36 with Barrett's metaplasia, 23 with esophageal squamous cell carcinoma, 10 with esophageal adenocarcinoma, and 19 with esophagitis or normal esophagus.

METHODS

We used enzyme immunoassay, immunoblotting, and immunoprecipitation assays for p53 antibodies; polymerase chain reaction, denaturant gradient gel electrophoresis, and sequencing for p53 mutations; and immunohistochemistry for p53 protein.

RESULTS

p53 antibodies were detected in 4 patients with Barrett's esophagus, including 1 with dysplasia that later progressed to adenocarcinoma, and in 10 cancer patients (P = 0.002) (8 squamous and 2 adenocarcinoma), 2 of whom (1 squamous, 1 adenocarcinoma) had antibodies before cancer was diagnosed. Other patient groups were too small for informative statistical analysis. Six antibody-positive cancer patients had p53 mutations, whereas 2 patients with cancer and 1 with Barrett's esophagus with antibodies had p53 protein overexpressed in esophageal tissues.

CONCLUSIONS

Patients with Barrett's esophagus and esophageal cancer can develop p53 antibodies that may predate the clinical diagnosis of malignancy.

[Antiandrogen treatment for nude mice model with ectopic transplanted human HCC]

OBJECTIVE

To investigate the effect of antiandrogen on hepatocellular carcinoma (HCC).

METHODS

Nude mice model with orthotopic transplanted human HCC was constructed and the androgen receptor (AR) in tumor and surrounding liver tissue was assayed dynamically. Nude mice with ectopic transplanted HCC were treated with flutamide (blocker of AR) at two different dosages (Group F1, F2), normal saline(Group C), and anticancer drug(Group M). The effect of treatments was compared among the groups.

RESULTS

The quantity of AR in nucleus and cytoplasm in tumor and tumor-surrounding tissue decreased with the increasing size of tumor in proper order. AR in tumor was significantly less in F1 and F2 groups than in other groups. The tumor weight of group F1, F2 and C had no significant difference (1.36 +/- 0.82 g, 2.66 +/- 1.40 g, 1.66 +/- 0.79 g, respectively), but was significantly higher than that of group M.

CONCLUSION

Androgen may play a role at the initial stage of hepatocarcinogenesis, and antiandrogen therapy may be ineffective in the established tumor.

The phosphodiesterase inhibitors pentoxifylline and rolipram prevent diabetes in NOD mice

Interleukin (IL)-12, interferon (IFN)-gamma, and other inflammatory cytokines play an important role in the pathogenesis of autoimmune insulitis and diabetes in NOD mice, and inhibition of these cytokines is likely to be beneficial. In this study, we found that Pentoxifylline (PTX) and Rolipram (phosphodiesterase [PDE] inhibitors that induce increased intracellular cAMP) can block inflammatory cytokine production. Inhibition of IL-12 and IFN-gamma secretion was demonstrated in macrophages activated with lipopolysaccharide or T-cells stimulated through the CD3/T-cell receptor complex, respectively. Moreover, strong inhibition of IL-12 was demonstrated in vivo in superantigen-immunized mice. Rolipram was inhibitory at concentrations as low as 10(-8) to 10(-7) mol/l, and on a molar basis, it was 100-fold more effective than PTX. Tumor necrosis factor-alpha was also inhibited, but IL-4 was less sensitive to suppression. In NOD mice, both PTX and Rolipram reduced the severity of insulitis and prevented diabetes, with or without cyclophosphamide administration (which precipitates onset of disease). This protection of NOD mice was still apparent over 10 weeks after withdrawal of the drug treatment. It appears that blocking the activity of type IV PDE is sufficient to mediate the effects reported in this study, since Rolipram inhibits only this isoform, unlike PTX (a general inhibitor). PTX and Rolipram may be effective in the treatment of autoimmune diabetes or other conditions characterized by excessive production of inflammatory cytokines.

[Hepatectomy for hepatolithiasis treatment of 354 cases]

OBJECTIVE

To evaluate the effect of hepatectomy for hepatolithiasis.

METHOD

354 patients with hepatolithiasis underwent hepatectomy in the past 10 years. The results were analysed retrospectively, including clinical findings, distribution of stones, patterns of operation, postoperative complications, and residual stones. The clinical data of the patients before 1990 were compared with those thereafter.

RESULT

Left hepatolithiasis was the most common form (323 patients). Left lateral lobectomy and left hepatectomy were most commonly employed (91.2%). 166 of the patients underwent concurrent cholangiojejunostomy. 13.8% patients had residual stones, and postoperative complications occurred in 60 patients, including 4 deaths. Few patients were reoperated on and the incidence of residual stones was lower after 1990. 88% the patients showed excellent or good result.

CONCLUSION

Hepatectomy is a procedure for the management of hepatolithiasis, but still requires combined plasty of stenotic intrahepatic bile ducts and cholangiojejunostomy to reduce the incidence of residual stones and recurrence.

III. New developments: 2. Virtual MR endoscopy in the central nervous system

Recent advances in three-dimensional (3D) data acquisition and postprocessing technologies have been playing a important role in widening the potential applications of 3D display. The authors described new applications of a virtual endoscopic algorithm for 3D display of high resolution MR images: (a) intracranial intravascular virtual MR endoscopy using the 3D fast imaging with steady state precession (FISP) sequence, and (b) virtual MR endoscopy of the cerebrospinal fluid (CSF) spaces using the constructive interference in steady state (CISS) three-dimensional Fourier transform (3DFT) sequence. The virtual endoscopic images were displayed with use of a commercially available perspective volume-rendering algorithm. Our initial experience showed that virtual MR endoscopy can be performed to observe the intracranial arteries and CSF spaces from the viewpoints within themselves. Although the clinical use of the intracranial virtual MR endoscopy has not been established yet, the images obtained are very attractive and further investigations in this field will be expected.

FIGalpha, a germ cell specific transcription factor involved in the coordinate expression of the zona pellucida genes

The mouse zona pellucida is composed of three glycoproteins, ZP1, ZP2 and ZP3, encoded by single-copy genes whose expression is temporally and spatially restricted to oocytes. All three proteins are required for the formation of the extracellular zona matrix and female mice with a single disrupted zona gene lack a zona and are infertile. An E-box (CANNTG), located approximately 200 bp upstream of the transcription start sites of Zp1, Zp2 and Zp3, forms a protein-DNA complex present in oocytes and, to a much lesser extent, in testes. It has been previously shown that the integrity of this E-box in Zp2 and Zp3 promoters is required for expression of luciferase reporter genes microinjected into growing oocytes. The presence of the ubiquitous transcription factor E12 in the complex was used to identify a novel basic helix-loop-helix protein, FIGalpha (Factor In the Germline alpha) whose expression was limited to oocytes within the ovary. The ability of FIGalpha to transactivate reporter genes coupled to each of the three mouse zona promoters in heterologous 10T(1/2) embryonic fibroblasts suggests a role in coordinating the expression of the three zona pellucida genes during oogenesis.

The acting site of bronchodilator, methacholine and upper respiratory tract infection on airways

BACKGROUND

The bronchodilator agent is an important drug for patients with chronic obstructive pulmonary disease. Methacholine is a popular bronchial provocative agent. Although the major acting site of bronchodilator, methacholine and upper respiratory tract infection (URI) has been evaluated in some studies, the sites are still in debate. This study investigated the exact major acting sites.

METHODS

Thirty subjects participated in this study. Episodes of URI were identified by a questionnaire. Spirometry, bronchial provocative test with methacholine, and five minutes' inhalation of a mixture of helium and oxygen (HeO2) were done on day one. Spirometry, bronchodilator test, with five minutes' inhalation of HeO2 and expiratory flow-volume (F-V) curve were performed on another day. The change of pre- and post-HeO2 VEMax50 was calculated as delta VEMax50. The pre- and post-bronchodilator VEMax50 and delta VEMax50 differences were counted to decide the acting site of bronchodilator. After bronchial provocative test with methacholine, the volume of isoflow (VisoV) was estimated from pre- and post-HeO2 F-V curve to establish the acting site of methacholine.

RESULTS

This study indicated that small airways are the major acting sites of bronchodilators, large airways are the major acting sites of methacholine and URI affects mainly large airways. Although airway hyperresponsiveness is more severe in subjects with positive methacholine response, the recovery of spirometry values is not significantly different between the methacholine-positive and -negative groups.

CONCLUSIONS

The major acting sites of the bronchodilator, methacholine, and URI are the small, large and large airways, respectively. Bronchial hyperresponsiveness is not a cause of quick restoration of spirometry values in subjects with positive methacholine response.

Studies on the precursors of strong mutagen [3-chloro-4-(dichloromethyl)-5-hydroxy-2(5H)-furanone]MX by chlorination of fractions from different waters

The strong mutagen, [3-chloro-4-(dichloromethyl)-5-hydroxy- 2(5H)-furanone] MX, was found to be one of the most potent mutagens in drinking water. In this study, dissolved organic matters from river water and lake water were separated into several compound classes by sorbtion on a series of resin absorbents. After chlorine treatment of the fractions, MX was determined with GC/MS in the selected ion monitoring mode. Humic substances produced more MX on a TOC-basis than other fractions and contributed more to MX formation in the chlorinated natural waters. Some phenols were detected in the oxidation products of humic substances and therefore formation of MX may occur when some phenolic precursor structures in humic substances are treated with chlorine.

[Studies on the chemical structure of lucyoside R from leaves of Luffa cylindrica roem]

A new pentacyclic triterpenoid saponin, lucyoside R, has been isolated from the leaves of Luffa cylindrica along with lucyoside G. Its stucture was established as 2 alpha, 21 beta-dihydroxyhederagenin-3-O-beta-D-glucopyranoside based on spectral and chemical evidence.

Translational repressor bruno plays multiple roles in development and is widely conserved

oskar (osk) mRNA is tightly localized to the posterior pole of the Drosophila oocyte, where the subsequent expression of Osk protein directs abdomen and germ-line formation in the developing embryo. Misplaced expression of Osk protein leads to lethal body patterning defects. The Osk message is translationally repressed before and during the localization process, ensuring that Osk protein is only expressed after the mRNA has reached the posterior. An ovarian protein, Bruno (Bru), has been implicated as a translational repressor of osk mRNA. Here we report the isolation of a cDNA encoding Bru using a novel approach to the expression cloning of an RNA-binding protein, and the identification of previously described mutants in the arrest (aret)-locus as mutants in Bru. The mutant phenotype, along with the binding properties of the protein and its pattern of accumulation within the oocyte, indicate that Bru regulates multiple mRNAs involved in female and male gametogenesis as well as early in embryogenesis. Genetic experiments provide further evidence that Bru functions in the translational repression of osk. Intriguingly, we find that Bru interacts physically with Vasa (Vas), an RNA helicase that is a positive regulator of osk translation. Bru belongs to an evolutionarily conserved family of genes, suggesting that Bru-mediated translational regulation may be widespread. Models for the molecular mechanism of Bru function are discussed.

Correlation between retinal fluorescein angiography and blood viscosity and other factors in patients with primary open angle glaucoma

OBJECTIVE

To investigate the correlation among retinal fluorescein angiography, blood viscosity, and other factors in patients with open angle glaucoma (POAG).

METHODS

Multiple step regression analysis was made to investigate the correlation between each of the following blood vessel filling times: the arm-choroid (A-CT), arm-retinal artery (A-AT), and retinal artery-venous (A-VT) of the fundus fluorescein angiography (FFA) in 122 eyes with POAG and each of the following related factors in hemorrheology: whole blood apparent viscosity at low, medium and high shear rates, plasma viscosity and hematocrit. Also, the same analysis was applied to investigate the correlation between each of the A-AT, A-VT of the FFA in 70 eyes with POAG and the following factors: systolic blood pressure, diastolic blood pressure, age and whole blood apparent viscosity at low shear rate.

RESULTS

The whole blood apparent viscosity at low shear rate was closely related to A-CT and A-AT, while hematocrit was closely related to A-VT of the FFA. The whole blood apparent viscosity at low shear rate and age, especially the whole blood apparent viscosity, was closely related to A-AT, A-VT of the FFA.

CONCLUSION

Blood viscosity can affect the filling times of the FFA in POAG.

[Immunogenecity of expressed protein p68 from recombinant plasmid rpDJt in L. interrogans serovar lai]

There are two types of infection caused by pathogenic microorganisms, intracellular infection and intercellular infection. Infection of pathogenic leptospira is an intercellular infection. The immunological reaction of host to intercellular infection is unique. The potential immunogen of an expressed protein should meet three criteria: it can be degraded (by antigen-present cells in the host); it should have antigenic epitope which can be recognized by specific antibodies and have at least one epitope that can be recognized by an MHC II protein and T cell receptor. In this study we report the cloning of an L. interrogans protein in plasmid rpDJt and the immunogencity of the expressed protein derivative. A genomic library of L. interrogans serovar lai strain 017 was constructed with the plasmid vector pUC18. Recombinant plasmids, designated pDJH2 and pDJ8 were screened from the bank. EcoRI-inserted fragment of 1. 9 kb recombinant DNA of pDJH2 was ligated into T7 RNA polymerase/promoter vectors (pT7-7). Then they were transformed into E. coli JM109 (De3), one of subclones, designated rpDJt was achieved. SDS-PAGE showed that the molecular weights of expression proteins were 68 kd and 23 kd respectively, designated p68 and p23. Purifying and isolating p68 and p23, we separated them from SDS-Polyacrylamide gels by using Side-Strip method. After fragmenting and electroeluting, p68 and p23 were injected into guinea pigs and rabbits. An extremely strong immune response to p68 was obtained since an anti-p68 antibody response could be detected to a dilution 1:524,288 (guinea pigs) and 1:262,144 (rabbits) by ELISA while anti-P23 antibody being 1:1024 (the same to guinea pigs and rabbits). The results of improved MTT and conA 3HTdR transformation methods showed the activities and proliferation of Th-cells were increased in guinea pigs after p68 immunization (IL-6, 83.25 IU/ml, IL-2, 28.75 IU/ml; RPI, 2.04, SI, 65.62%) Thlymphocyte existed in two subclasses, the Th1- and Th2-cells. A major role of Th2-cells is to "help" B-cells differentiate, replicate, and secrete antibody. The properties of these interactions explain why p68 makes good antigen and p23 does not. The antigens responsible for eliciting the production of protective antibodies are not known; however, several outer membrane proteins on L. interrogans are candidates for vaccine. Our results suggest that expresion protein p68 from recombinants (rpDJt) may be a candidate for gene engineered subunit vaccine for Leptospirosis.

Effect of portal venous flow augmentation on liver enhancement with CT

BACKGROUND

The purpose of this study was to evaluate the effect of portal flow augmentation on hepatic computed tomographic (CT) enhancement.

METHODS

Thirteen patients undergoing follow-up CT of the liver within 6 months of initial study ingested 470 mL of Ensure 30 min before the second examination. Contrast medium injection and scanning parameters were identical for both studies.

RESULTS

The time to peak and the maximum and mean liver enhancements were 68 s, 56 HU, and 46 HU, respectively, for the examinations without Ensure and 68 s, 53 HU, and 44 HU for the examinations with Ensure. No significant difference was found between the two groups when mean liver enhancement was calculated over 3-s time intervals.

CONCLUSION

Portal venous flow augmentation induced by a meal had no effect on liver enhancement.

[Construction of genomic library of L. interrogans serovar lai using lambda gt11 as the vector and a study of recombiant plasmid pDL121]

A genomic library of L. interrogans serovar lai strain 017 has been constructed using lambda gt11 as the vector. DNA was partially digested by two blunt-end restriction enzymes, then methylated with EcoR I methylase; after EcoR I linker was added to the DNA, the linker-ended DNA was ligated to the dephosphorylated EcoR I digested lambda gt11 arms. The recombined DNA was packaged in vitro, and used to transduct E. coli Y1090 for amplification. There were 2.1 x 10(6) recombinant bacteriophages as recognized by their ability to form white plaques plated on Lac host in the presence of both IPTG and X-Ga1. A positive clone, designated lambda DL12, was screened with a rabbit anti-serum against L. interrogans serovar lai from the genomic library. The DNA from lambda DL12 was subcloned into plasmid pUC18. A recombinant (designated as pDL121) was obtained. SDS-PAGE analysis indicated that a 23 kd was expressed in E. coli JM 103 harboring pDL121. Western blotting analysis showed that a specific protein band molecular weight of 23 kd could be recognized by the rabbit antiserum against L. interrogans serovar lai strain 017.

Splenic hemangiomas and hamartomas: MR imaging characteristics of 28 lesions

PURPOSE

To determine the magnetic resonance (MR) imaging features of splenic hemangiomas and hamartomas, including their pattern of dynamic contrast material enhancement.

MATERIALS AND METHODS

The appearance of 28 lesions in 18 patients was retrospectively reviewed on T2-weighted images (16 patients), unenhanced T1-weighted images (18 patients), and dynamic contrast-enhanced T1-weighted images (17 patients). Seventeen of 23 hemangiomas and all five hamartomas were proved at pathologic examination.

RESULTS

Of the 22 hemangiomas imaged with T2-weighting, 19 were hyperintense, two were isointense, and one was hypointense relative to the spleen. Dynamic gadolinium-enhanced imaging demonstrated a progressive centripetal pattern of enhancement in 19 of 22 hemangiomas. On delayed images, 19 hemangiomas demonstrated uniform enhancement. Of the five hamartomas, four were imaged with T2-weighting; three were hyperintense and one was hypointense relative to the spleen. All hamartomas demonstrated diffuse heterogeneous enhancement on images obtained early after administration of contrast material and became more uniformly enhanced on delayed images.

CONCLUSION

Splenic hemangiomas showed signal intensity characteristics and enhancement patterns similar to those described for hepatic hemangiomas. Since these features have been shown to reliably distinguish hemangiomas from other benign and malignant liver lesions, it may be reasonable to consider without histologic verification that lesions in the spleen with these imaging features represent hemangiomas.

[Research on the recombinant plasmid pDJH2 of L. interrogans serovar lai: sequencing and alignment with other known bacterial Omp sequence]

The Leptospira whole cell vaccine (LWCV) currently used in China is safe and effective, out the immunity following vaccination with two doses of the fluid medium vaccine is of low order. The duration of immunity conferred by this vaccine is rather short, six months or at most one year. Therefore, it is necessary to develop new generation vaccines against Leptospirosis for the developing world. In this paper we report the sequencing of the insert fragment of pDJH2 from genomic DNA of L. interrogans sevovar lai strain 017 and its alignment with other bacterial omp sequences. A genomic library of Leptospira interrogaans serovar lai strain 017 was constructed with the plasmid vector pUC18. A recombinant plasmid designated pJDH2 was screened from the genomic library. Inserted fragment of pDH2 is 1.9 kb by gel electrophoresis. Immunization/protection was studied in BALB/c mice model. The results showed highly significant difference between pDJH2 and pUC18 (control). Inserted fragment of pDJH2 DNA sequencing was performed by Dr Yan Zhengxin (Max-Planck-Institut for Biology. Tubingen, Germany). Insert fragment was cloned into pBluescript II KS-(stratagene) and sequenced by using AB1 (Applied Bio Systems, Model 373A). Two open reading frames of 565 and 662 nucleotides were identified. There were identifiable initiation codons, terminators, Shine-Dalgano ribosome combining site, Pribnow boxes and Sextama boxes within the 2 sequenced regions. Nucleotide sequences were analysed using Gene Work, a suit of computer program developed by Department of Biochemistry St. Jude Children's Research Hospital Memphis. U.S.A. The results of formatted alignment showed the predicted nucleotide sequence of ORF1 of the serovar lai had significant similarity with ORF2 (49.36%). L. kirschneri ompL1 (49.26%), Borrelia burgdoferi omp (48.97%), Treponema phagedenis omp (47.3%); Salmonella typhimurium ompC(46.87%), Yersinia enterocolitica ompH (46.7%), Leptospira borgpeterseni pfap (46.3%), and Serratia marcescens omp (43.3%). The close relationship of the pDJH2 ORF1 and ORF2 nucleotide sequences from Leptospira kirschneri ompL 1 is apparent. Whether the recombinant pDJH2 will prove useful for vaccine development remains to be tested.

[Subclones of fragment DNA recombinant rpDJH2 of L. interrogans serovar lai strain 017 and it's expression of high level in E. coli]

Fragment of 1.9 kb recombinant DNA of pDJH2 was linked with vectors pT7-7 and pRSETs. Then they were transformed into E. coli JM109 (DE3) respectively. Expression of subclones was achieved in E. coli JM109 (DE3) with IPTG inducement. SDS-PAGE showed that the molecular weights of products were 68kd and 23 kd respectively. The amount of production seemed to be higher than that of the outer membrane proteins of L. interrogans serovar strain 017 in nature. Immunoblotting of pDJt and pDJrB2 (both are subclones) with the specific antiserum of anti-OMP of L. interrogans serovar lai strain 017 and the experiment of initiative immuno-protection in guinea pigs showed both protein-68 kd and 23 kd might be the antigens of immuno-protection on the outer membrane of L. interrogans serovar lai strain 017.

Circulating anti-p53 antibodies in esophageal cancer patients are found predominantly in individuals with p53 core domain mutations in their tumors

Serum antibodies reacting with the tumor suppressor protein p53 have been detected previously in cancer patients with a variety of neoplasms. Two initial (although insufficient) prerequisites for a B-cell response to occur have been proposed: p53 protein accumulation in the tumor or a mutant p53 gene, or both. We have examined 65 esophageal cancer cases (42 from Guangzhou and Shenyang, People's Republic of China, and 23 from Paris, France) to obtain a prevalence estimate of anti-p53 antibodies for this type of cancer and to define the relationship of p53 tumor status to B-cell immune response. Sera were analyzed in a triplicate assay (enzyme-linked immunoassay, immunoprecipitation, and immunoblot) for anti-p53 antibodies. Tumor DNA was screened for mutations in exons 5-8, and tumor tissue was examined by immunohistochemistry for abnormal p53 protein accumulation. p53 mutations were found in 36 (58%) of 62 cases analyzed. Sixteen patients (25%) had circulating antibodies to the tumor suppressor protein. All but two (88%) of the tumors from seropositive cases had a mutation in the DNA binding region of the p53 gene, and with one exception, these tumors also showed nuclear accumulation of the p53 protein. In contrast, tumor mutations were found in just 22 (46%) of the 48 individuals in whom we did not detect anti-p53 antibodies. Among the 22 seronegative cases for which we found no tumor mutations, 11 revealed p53 protein accumulation by immunohistochemical analysis. Thus, circulating anti-p53 antibodies may be present in one-fourth of esophageal cancer patients, most of whom also would be expected to have a p53 gene mutation in their tumors. Patients without such mutations appear considerably less likely to mount a B-cell response to the p53 tumor suppressor protein than those that do (P < 0.01).

Oxidative stress activates metal-responsive transcription factor-1 binding activity. Occupancy in vivo of metal response elements in the metallothionein-I gene promoter

Oxidative stress (tert-butylhydroquinone) rapidly induced metallothionein-I gene expression in mouse Hepa cells, and this effect was mediated predominantly through metal response promoter elements in transient transfection assays. In vivo genomic footprinting of the mouse metallothionein-I promoter after treatment of Hepa cells with hydrogen peroxide, tert-butylhydroquinone, or zinc suggested a rapid increase in occupancy of the metal response elements. More subtle changes also occurred in the constitutive genomic footprint at the composite major late transcription factor/antioxidant response element. This element may, in part, mediate induction by hydrogen peroxide. Electrophoretic mobility shift assays demonstrated a rapid (30 min) increase in the DNA binding activity of metal-responsive transcription factor-1 in Hepa cells treated with any of these inducers. In control cells, upstream stimulatory factor binding with the major late transcription factor site, and a nuclear protein complex distinct from AP-1, but specific for the antioxidant response element, were detected. The amounts of these complexes were not altered after these treatments. These studies indicate that metal-responsive transcription factor-1 plays a role in activating mouse metallothionein-I gene transcription in response to reactive oxygen species.

[Treatment of irresectable hepatocellular carcinoma with repeated transient dearterialization]

A joint clinical prospective study between SUMS and Lund university was reported. 40 patients with the irresectable hepatocellular carcinoma (HCC) admitted to the department of HPB surgery in the First Affiliated Hospital of SUMS were randomized into two groups: (20 each) from Feb. 1994 to April, 1995. The patients were treated with hepatic artery ligation (HAL) and repeated transient dearterialization (RTD) respectively. Postoperative response to treatment, liver function change (ALT), AFP, imaging examination of the tumor, patient's survival were evaluated. It has been shown that RTD is superior to HAL in terms of the objective response to the therapy, reduction of tumor size, patient's symptom relief, liver function and AFP changes and patient's survival. In the RTD group, the effective rate was 70%, the mean survival time was 8.2 months, and the 6-month survival rate was 79.7%. In HAL group, the effective rate was only 5%, the mean survival time was 5.1 months, 6 months survival rate was 35.8%. It has been postulated that RTD may prevent the rapid development of collateral circulation and increase the production of oxygen-derived free radicals, which may be the responsible factors for the ischemic treatment of hepatic tumours. We consider that RTD would be a promising polliative method for HCC.

[Androgen receptor in hepatocellular carcinoma and the surrounding liver tissues in China]

To investigate the reasons why primary liver cancer (hepatocellular carcinoma, HCC) is prevalent in male, androgen receptors (AR) in cytoplasm and nucleus were quantitatively detected in tumor tissue and tumor-adjacent tissue of 23 patients with HCC and liver tissue of normal livers by means of receptor radio-ligand binding assay. The concentrations of AR in cytoplasm and nucleus were as follows: 0.20-5.30, 1.91-6.50 fmol/mg protein in normal liver tissue; 5.12-27.62, 10.73-47.18 fmol/mg protein in tumor tissue; and 3.18-14.98, 5.15-36.32 fmol/mg protein in tumor-surrounding tissue. The mean concentrations of AR in cytoplasm or nucleus decreased in the order of tumor tissue, tumor-surrounding tissue and normal liver tissue, and the differences among them were statistically significant. The concentration of AR in tumor tissue and tumor-adjacent tissue had no direct or indirect association with sex, age, abuse of alcohol, HBsAg, HBcAb, AFP, pathological type of tumor, differentiation degree of tumor cells and the underlying liver disease. The result suggests that the prevalence of HCC in male over in female in China may be somehow related to the expression of AR in tumor cells.

Effect of rate of contrast medium injection on hepatic enhancement at CT

PURPOSE

To determine the effect of the rate of contrast medium injection on liver enhancement at computed tomography (CT).

MATERIALS AND METHODS

Forty-five patients who underwent a follow-up CT examination of the liver were included in five different groups according to the compared rates of contrast material delivery: group A, 2 versus 3 mL/sec; group B, 2 versus 4.5 mL/sec; group C, 3 versus 4.5 mL/sec; group D, 3 versus 6 mL/sec; and group E, 4.5 versus 6 mL/sec.

RESULTS

Time to peak enhancement was shorter for the faster rates of injection. In each group, maximum enhancement was nearly identical for the paired examinations (group A, 57 vs 58 HU; group B, 48 vs 47 HU; group C, 55 vs 58 HU; group D, 55 vs 54 HU; group E, 62 vs 61 HU, respectively). Mean enhancement in each group was similar when calculated at 3-second intervals.

CONCLUSION

Higher rates of injection shorten the time to peak liver enhancement but have no effect on maximum liver enhancement.

Diffuse adenomyosis: comparison of endovaginal US and MR imaging with histopathologic correlation

PURPOSE

To compare the accuracy of endovaginal ultrasound (US) and magnetic resonance (MR) imaging in the diagnosis of adenomyosis.

MATERIALS AND METHODS

The authors prospectively studied 119 consecutive patients undergoing hysterectomy. The endovaginal US scans and MR images were interpreted independently in a double-blind fashion. Imaging findings were compared with those at histopathologic examination.

RESULTS

At histopathologic examination, adenomyosis was found in 28 of the 119 patients (24%). Sensitivity and specificity was 89% for endovaginal US and 89% for MR imaging. The positive predictive value was 71% for US and 65% for MR imaging. The negative predictive value was 96% for US and 95% for MR imaging. There was no statistically significant difference between the sensitivities (P = .65) and specificities (P = .75) of endovaginal US and MR imaging. The mean junctional zone (JZ) thickness on MR images in patients with and without proved adenomyosis was 15.0 mm +/- 4.9 and 7.7 mm +/- 3.3, respectively (P < .0001). When receiver operating characteristic curves were applied retrospectively, the optimal JZ value for the diagnosis of adenomyosis with MR imaging was > or = 12 mm.

CONCLUSION

Endovaginal US was as accurate as MR imaging in the diagnosis of uterine adenomyosis. Use of a JZ thickness of > or= 12 mm should further optimize the diagnostic accuracy of MR imaging.

[The PCR amplification, cloning, sequencing, expression in E. coli of gene encoding endoflagella subunit protein (fla B) from Leptospira interrogans serovar lai]

A pair of oligonucleotide primers were designed by ourselves to amplify the endoflagella gene of L. interrogans serovar lai. A fragment about 840 bp was generated with PCR and inserted into plasmid pUC8 after the fragment and pUC8 were digested respectively with Bam HI and Pst I. A recombinant plasmid (designated as pLF1) was obtained. SDS-PAGE analysis indicated that a 33 kd was expressed in E. coli JM103 harboring pLF1 and the expression level of the protein was 11% of total bacterial soluble proteins. Western blot analysis showed that the protein band could be recognized by the antiserum against the endoflagella (Axiall filament) of Leptospira interrogans serovar lai. Nucleotide seguence data showed an open reading frame encoding 282 aminoacids residues, corresponding to a protein of molecular weight 33.6 kd. The G + C content of endoflagella subunit protein gene was 48 mol%. Therefore, the G + C content of the leptospiral fla B Gene is significantly higher than the reported 39 mol% G + C content of leptospiral genome of L.interrogans serovar lai but similar to the G + C of the Treponema pallidum genome. Comparison of the deduced endoflagellar subunit protein (fla B) amino acid sequence with flagellins from other bacteria revealed a high level of identity with the Treponema pallidum fla B proteins. Immunization/protection experiment was performed on the model of BALB/c mice and showed that the survival rate in the group JM103-pLF1 was higher than that in the group JM103-pUC8, but statistically the difference between them was significant (P < 0.05) and pLF1 did not induce significant levels of agglutinating antibodies against L.interrogans serovar lai.

Regulation of interleukin-6 and interleukin-1 beta gene expression in the mouse deciduum

Expression and regulation of interleukin-6 (IL-6) and IL-1 beta were examined in the mouse deciduum and in experimentally induced deciduoma from 6 to 8 days postcoitum (1 dpc = vaginal plug), as well as in cultured mouse decidual cell preparations. Levels of these mRNAs in the deciduum and deciduoma were below the limits of detection by Northern blotting. However, enzymatic dispersion and culture of decidual cells and/or exposure to bacterial endotoxin-lipopolysaccharide (LPS) induced these mRNAs. IL-6 levels that accumulated in the culture medium (3990 pg/3 x 10(6) cells/day) were about 90-times higher than those of IL-1 beta (45 pg/3 x 10(6) cells/day). Progesterone (10(-7) M) modestly (40%) reduced the levels of IL-6 mRNA and protein during culture, whereas LPS dramatically (8-fold) and rapidly induced IL-6 and IL-1 beta mRNAs and proteins. In vivo, few IL-1 beta immunopositive cells were localized by immunohistochemistry in the 8 dpc deciduum. In contrast, IL-6 mRNA was localized by in situ hybridization in dispersed clusters of a few cells in the mesometrial deciduum near the center of the implantation site. LPS rapidly induced interleukin mRNAs in the deciduum and deciduoma. After LPS injection, IL-1 beta immunopositive cells were dispersed in the myometrium and mesometrial deciduum. In contrast, after LPS injection (2 h), IL-6 mRNA was abundant in 'cords' of cells that traverse the mesometrial deciduum longitudinally, as well as in cells dispersed throughout the myometrium. Thus, the IL-1 beta and IL-6 genes are expressed and regulated in distinct subsets of cells in the decidual bed. The pattern of F4/80 immunostaining is consistent with macrophages as the major, if not only, source of decidual IL-1 beta. IL-6 is also expressed in these cells. However, IL-6 gene expression is regulated in a distinct subset of cells located in the mesometrial decidual bed of the mouse.

Transgenic mouse blastocysts that overexpress metallothionein-I resist cadmium toxicity in vitro

The role of metallothionein with regard to cadmium toxicity in vitro was investigated using preimplantation mouse blastocysts derived from a transgenic strain that constitutively overexpresses metallothionein-I transgenes (MT-I*). Northern blot and in situ hybridization revealed high levels of MT-I mRNA in transgenic blastocysts when compared with control blastocysts, and reverse transcriptase-polymerase chain reaction-amplified MT-I mRNA was almost exclusively MT-I*. Moreover, pulse-labeling experiments showed that the relative rate of synthesis of MT was 9-fold higher in transgenic blastocysts. Cadmium (Cd2+) toxicity was assessed after incubating blastocysts for 4 hr in Whitten's medium containing 50 microM Cd2+. Embryos that displayed abnormal morphology were judged "sensitive". Transgenic blastocysts were more resistant to cadmium-induced morphological changes than were control blastocysts. "Sensitive" and "resistant" blastocysts were individually genotyped by polymerase chain reaction, or they were transferred to foster mothers, and embryonic development to midterm was monitored. Of the blastocysts derived from mating heterozygous transgenic males with control females, 56% were transgenic before incubation with Cd2+, whereas 95% of the blastocysts that retained normal morphology after incubation were transgenic. Moreover, after Cd2+ exposure, transgenic blastocysts with normal morphology were nine times more likely to develop to midterm than were control blastocysts with normal morphology. Blastocysts with abnormal morphology failed to develop to midterm. These studies indicate that MT plays a central role in protection from Cd2+ toxicity within the physiological context of the developing mouse embryo.

Transcriptional and posttranscriptional regulation of interstitial collagenase by platelet-derived growth factor BB in bone cell cultures

Platelet-derived growth factor (PDGF), a bone cell mitogen, stimulates bone collagen degradation and does not enhance bone matrix apposition rates. The mechanism of the effect on collagen degradation is unknown, and it could involve changes in interstitial collagenase synthesis. We tested the effects of PDGF on interstitial collagenase expression in cultures of osteoblast-enriched cells from fetal rat calvariae (Ob cells). After 4-8 h of treatment, PDGF BB at 0.3 nM increased steady state collagenase messenger RNA (mRNA), whereas PDGF AA had no effect. The effect of PDGF BB on collagenase transcripts was dose dependent. PDGF BB increased the levels of immunoreactive collagenase after 6 h, whereas the levels were decreased after 16 h. Stimulation of collagenase mRNA by PDGF BB was dependent on de novo protein synthesis and activation of protein kinase C. PDGF BB prolonged the half-life of collagenase mRNA in transcriptionally arrested cells. PDGF BB initially increased and subsequently decreased the rate of collagenase gene transcription and the levels of collagenase heterogeneous nuclear RNA. In conclusion, PDGF BB regulates interstitial collagenase in Ob cells by transcriptional and posttranscriptional mechanisms, and this effect may contribute to its stimulatory actions on bone collagen degradation.

[The evaluation of adenosine triphosphate bioluminescence assay for chemosensitivity testing of ovarian cancer cell line]

OBJECTIVE

To assess the efficacy of adenosine triphosphate (ATP) assay for chemosensitity testing of ovarian cancer cell line and to compare its predicting value with that of diphenyltetrazolium bromide (MTT) test.

METHODS

By using ATP assay and MTT test the cytotoxic effect of 7 anticancer drugs on ovarian cancer cell line AO were determined. The sensitivity and stability of ATP assay were compared with those of MTT test. The optimal time of exposure of the cells to the drugs before doing ATP chemosensitity assay is investigated.

RESULTS

(1) The results obtained by ATP assay correlate well with that by MTT test (r = 0.918 1). However, in 90% of the assay samples the cytotoxic effect of the chemotherapeutic agents on cancer cells detected by ATP assay was 10% or more stronger as compared with that determined by MTT test. The difference in sensitivity of the two assays was also demonstrated by the least number of living cells. A change of living cells of 60 per well could be detected by ATP assay while that detected by MTT test should be 200 per well. (2) By repeating the tests of a same batch of samples for 5 times, it revealed that the results obtained by ATP assay was more stable than MTT test. The difference between the sx- (standard error) of the two tests was significant (P < 0.05). (3) The optimal time of exposure of the cancer cells to the anticancer drugs for testing its chemosensitivity was 5 days.

CONCLUSIONS

The method of ATP assay for chemosensitivity test is simple and convenient with high sensitivity and stability. It may be used as a new in vitro chemosensitivity test in patients with ovarian cancer.

Activation of the complete mouse metallothionein gene locus in the maternal deciduum

The mouse metallothionein (MT) gene family consists of four known members (MT-I through IV) clustered on chromosome 8. Studies reported herein examine the expression and regulation of the MT-III and MT-IV genes in specific cell types in the maternal reproductive tract, developing embryo, and fetus known to express the MT-I and -II genes. MT-III and MT-IV mRNAs were absent from the visceral yolk sac, placenta, and fetal liver, tissues with high levels of MT-I and MT-II mRNAs. In contrast, MT-III and MT-IV mRNAs were both abundant in the maternal deciduum, and in experimentally induced deciduoma on 7 and 8 days postcoitum (1 dpc = vaginal plug), as are MT-I and -II mRNAs. The abundance of each of these MT mRNAs increased coordinately during development of the deciduum (6-8 dpc), and in situ hybridization localized MT-I, MT-III, and MT-IV mRNAs to the secondary decidual zone of the antimesometrial region on 8 dpc, where in some regions all of the cells were apparently positive. Thus, all of the known mouse MT genes are co-expressed in at least some of the cells in the secondary decidual zone. Electrophoretic analysis of decidual MT suggested that the MT-I, -II, and -III isoforms are abundant proteins in the secondary deciduum. Bacterial endotoxin-lipopolysaccharide (LPS) and Zn are powerful inducers of MT-I and MT-II gene expression in many adult organs, whereas these agents apparently have little effect on MT-III and MT-IV gene expression. Neither of these agents significantly effected levels of decidual MT-III or MT-IV mRNAs in vivo or in primary cultures of decidual cells in vitro, and only modest effects of Zn on MT-I mRNA levels were noted. During 2 days of in vitro culture, decidual cell MT-I and MT-III mRNA levels remained elevated while MT-IV mRNA levels decreased. Thus, expression of the mouse MT gene locus in the deciduum appears to be developmentally regulated, and in this tissue, the MT genes are refractory to induction by Zn or inflammation.

Synthesis and antimicrobial activity of 6,7-annulated pyrido[2,3-d]pyrimidines

Four new 6H-indeno[2',1':5,6]pyrido[2,3-d]pryimidines (10-13) were synthesized via cyclocondensation reactions involving chlorovinyl aldehyde 1 or ketoaldehyde 3 and appropriately substituted 6-aminopyrimidines. The regiochemistry of the compounds was established by 1H NMR and 13C NMR spectral data as well as X-ray crystal data. Compounds 10 and 11 and previously reported homologues 14 and 15 were screened for antimicrobial activity. Moderate antimicrobial activity was observed for some of these compounds. Compound 14 was especially active against Staphylococcus aureus. Crystal data for 13 (C14H7N3Cl2) follows: monoclinic space group, P21/n; Unit cell dimensions, a = 7.284(1) A, b = 12.800(1) A, c = 13.108(1) A, beta = 93.98(1) degree, V = 1219.2(2) A3, Z = 4.

Differential expression and regulation of cytokine genes in the mouse uterus

The present investigation examined the differential expression of cytokine genes in vivo and in vitro in the mouse uterus and their regulation by ovarian steroid hormones. The expression of interleukin-1 beta (IL-1 beta), IL-1 alpha, IL-6, and tumor necrosis factor-alpha (TNF alpha) genes was examined in the mouse uterus as well as in freshly isolated or cultured epithelial cells by Northern blot and in situ hybridization. In the day 1 pregnant (D1 = vaginal plug) uterus, the levels of IL-1 alpha and IL-1 beta messenger RNAs (mRNAs) were abundant, whereas those of TNF alpha and IL-6 were at the limits of detection. Freshly isolated D1 uterine epithelial cell preparations contained higher levels of IL-1 alpha and IL-1 beta mRNAs than those observed in the D1 whole uterus, whereas TNF alpha and IL-6 mRNA levels were consistently low. In contrast, D1 epithelial cells showed decreased levels of IL-1 beta mRNA after 1 day of culture, whereas the levels of IL-1 alpha and IL-6 mRNAs increased under similar conditions. The levels of IL-1, IL-6, and TNF alpha mRNAs were at the limits of detection in the D4 whole uterus or freshly isolated diestrous epithelial cells. However, IL-1 alpha and IL-6 mRNA levels in diestrous epithelial cells, like those in D1 epithelial cells, increased in culture. In contrast, IL-1 beta and TNF alpha mRNA levels remained low in cultured epithelial cells. In situ hybridization was used to examine the cell type-specific expression of IL-1 alpha or IL-6 mRNA in uterine sections and cultured cells. Although hybridization signals for IL-1 alpha mRNA were detected in uterine epithelial cells on D1 of pregnancy, IL-6 mRNA could not be detected. IL-1 alpha and IL-6 mRNAs could not be detected in freshly isolated diestrous epithelial cells, although a majority of the epithelial cells showed hybridization signals for these mRNAs after 2 or 4 days of culture. The effects of steroid hormones on uterine cytokine gene expression were examined by Northern blot and in situ hybridization. In adult ovariectomized mice, an injection of 17 beta-estradiol (E2), progesterone (P4), or a combination of E2 and P4 had little or no apparent effect on these cytokine mRNA levels. The results establish that uterine epithelial cells on D1 of pregnancy exhibit heightened expression of IL-1 alpha in culture. In contrast, these cells express little or no IL-6 mRNA in vivo, but show heightened expression in culture. These results suggest that an apparent loss of repression of these uterine genes occurs in culture. Furthermore, E2 and/or P4 treatments appear to have little or no effect on uterine cytokine mRNA levels in adult ovariectomized mice.

Pentamidine congeners. 3. Crystal structure and molecular modeling studies of trans-1,4-bis(4-amidinophenoxy)-2-butene

X-ray diffraction was used to confirm the geometry of trans-1,4-bis(4-amidinophenoxy)-2-butene dihydrochloride dihydrate (trans-butenamidine). trans-Butenamidine is a semirigid analogue of pentamidine that has demonstrated good anti-Pneumocystis carinii activity in rats. Molecular modeling studies revealed that unlike pentamidine or propamidine, trans-butenamidine does not discriminate between AT and TA sequences in its binding to the minor groove of DNA. Crystal data: [C18H22N4O2(2+)][Cl(-)]2[H2O]2, triclinic space group, P1, a = 9.443(1) A, b = 11.400(1) A, c = 11.919(1) A, alpha = 62.19(1) degree, beta = 81.10(1) degree, gamma = 72.19(1) degree, V = 1080.3(3) A3, Z = 2, R = 0.054 for 1149 observed reflections with I > 3 sigma (1).

Tyrosine phosphorylation induced by cross-linking of Fc gamma-receptor type II in human neutrophils

Neutrophils express several receptors for the Fc region of IgG molecules. Specific cross-linking of the type II receptor (Fc gamma RII) can be achieved by treating neutrophils with the Fab fragment of a specific monoclonal antibody IV.3 against the receptor followed by goat anti-mouse IgG F(ab')2 fragment. Such treatment initiates a number of neutrophil responses including the release of O2-. and increased protein tyrosine phosphorylation. The increase in tyrosine phosphorylation is rapid and transient and correlates with O2-. release. Both responses are inhibited by pretreatment of neutrophils with a protein tyrosine kinase inhibitor, genistein. The increase in protein tyrosine phosphorylation is not inhibited by pretreatment of neutrophils with pertussis toxin or an intracellular Ca2+ chelator, but is enhanced by a phosphoprotein phosphatase inhibitor, okadaic acid. The activity of a neutrophil Ca2+/calmodulin-dependent protein kinase II (CAMPKII) is also stimulated by cross-linking Fc gamma RII. The increase in CAMPKII activity is inhibited by pretreatment with either genistein or Ca2+ chelator. The results suggest that the increase in protein tyrosine phosphorylation induced by cross-linking of Fc gamma RII requires neither pertussis-toxin-sensitive G-proteins nor a rise in intracellular Ca2+ but can be regulated by protein phosphatases. Furthermore, protein tyrosine phosphorylation may be an early signal functionally linked to Fc gamma RII-mediated signal transduction leading to CAMPKII activation and O2-. release in human neutrophils.

Activation of multiple protein kinases induced by cross-linking of Fc gamma RII in human neutrophils

Several neutrophil protein kinases that undergo changes in activity during Fc gamma RII activation have been investigated. These kinases include calcium/calmodulin-dependent protein kinase II (CAMPKII), mitogen-activated protein kinase (MAPK), and histone H4 protein kinase (PKH4). They are rapidly and transiently activated in a dose-dependent manner by the cross-linking of Fc gamma RII. The activation of CAMPKII but neither PKH4 nor MAPK was inhibited by treating the cells with either a tyrosine kinase inhibitor, genistein, or an intracellular calcium chelator, BAPTA/AM. The superoxide production induced by cross-linking Fc gamma RII can be inhibited partially by various protein kinase inhibitors: 33% by protein kinase C inhibitor calphostin C, 30% by CAMPKII inhibitor KN-62, and 62% by tyrosine kinase inhibitor genistein. These results indicate that cross-linking of Fc gamma RII induces multiple signaling pathways that lead to the activation of various protein kinases. The activation of these kinases may be involved directly or indirectly in the regulation of superoxide production.

Crystal and molecular structures of tricyclic neuroleptics

The X-ray crystal structures of three tricyclic neuroleptics have been completed and are reported herein. These include amitriptyline hydrochloride (I), chlorprothixene hydrochloride (II), and ethopropazine hydrochloride (III). The structures were compared with the structures of similar molecules with similar pharmacological activity. It was found that there is a great deal of flexibility in the structures of these molecules, which makes it difficult to determine the pharmacologically active conformations. Crystallographic data: (I) C20H24NCl, monoclinic space group P2(1)/a, a = 13.812(4) A, b = 9.140(2) A, c = 14.345(4) A, beta = 96.82(2) degrees, Z = 4, final R = 0.059 for 1630 observed (l > 3 sigma(l)) reflections. (II) C18H20NSCl2.CHCl3, monoclinic space group C2/c, a = 29.416(4) A, b = 6.986(1) A, c = 23.374(3) A, beta = 109.78(1) degrees, Z = 8, final R = 0.046 for 1436 observed reflections. (III) C19H25N2SCl, monoclinic space group P2(1)/c, a = 8.849(1) A, b = 14.475(2) A, c = 14.832(1) A, beta = 98.72(1) degrees, Z = 4, final R = 0.039 for 2583 observed reflections.

Localization of vasa protein to the Drosophila pole plasm is independent of its RNA-binding and helicase activities

The Drosophila gene vasa encodes a DEAD-box protein, which is localized during early oogenesis to the perinuclear region of the nurse cells and later to the pole plasm at the posterior end of the oocyte. Posterior localization of vasa protein depends upon the functions of four genes: capu, spir, osk and stau. We have found that localization of vasa to the perinuclear nuage is abolished in most vas alleles, but is unaffected by mutations in four genes required upstream for its pole plasm localization. Thus localization of vasa to the nuage particles is independent of the pole plasm assembly pathway. Furthermore, electron-dense nuage particles are less abundant in the cytoplasm of nurse cells from vas mutants that fail to exhibit perinuclear localization, suggesting that the formation of the nuage depends upon vas function. Eight of nine vas point mutations cause codon substitutions in a region conserved among DEAD-box genes. The proteins from two mutant alleles that retain the capacity to localize to the posterior pole of the oocyte, vasO14 and vasO11, are both severely reduced in RNA-binding and -unwinding activity as compared to the wild-type protein on a variety of RNA substrates including in vitro synthesized pole plasm RNAs. Initial recruitment of vasa to the pole plasm must consequently depend upon protein-protein interactions but, once localized, vasa must bind to RNA to mediate germ cell formation.

Simultaneous determination of mercury speciation in biological materials by GC/CVAFS after ethylation and room-temperature precollection

We developed a method for the simultaneous determination of monomethyl mercury (MMHg), inorganic mercury [Hg(II)], and total mercury (THg) in biological materials. A variety of biological materials can be digested in methanolic KOH solution. The MMHg and Hg(II) present are converted to volatile ethyl derivatives, methylethyl mercury and diethyl mercury, by an aqueous-phase ethylation reaction with sodium tetraethylborate. The ethyl derivatives are precollected onto a trapping column at room temperature, in case of disconnection with the separation/detection system, and then thermally desorbed into a packed isothermal gas chromatography (GC) column. Eluted organo-Hg compounds from the GC column are decomposed into Hg0, and detection is completed by cold vapor atomic fluorescence spectrometry (CVAFS). Pure standard solutions can be used for calibration. The sum of MMHg and Hg(II) obtained by this method equals the THg value obtained by digestion with HNO3 and H2SO4, reduction with SnCl2, and single-stage amalgamation/CVAFS for all biological materials studied. Absolute detection limits are 0.6 pg and 1.3 pg of Hg as MMHg and Hg(II), respectively, corresponding to 0.3 ng and 0.6 ng/g (wet) of sample.

Rapid modification of ribosomal S6 kinase II (S6KII) in rabbit peritoneal neutrophils stimulated with chemotactic factor fMet-Leu-Phe

The ribosomal S6 kinase II (S6KII) in rabbit neutrophils was studied by immunoblotting with antibodies prepared against recombinant S6KII. A protein with apparent molecular weight of 80,000 Da in SDS-gel was recognized by the antibodies. A shift of the apparent molecular weight to 84,000 Da in SDS-gel was observed in cells stimulated with the chemotactic factor fMet-Leu-Phe. Cytochalasin B and phorbol 12-myristate 13-acetate, but not A23187, stimulated both the tyrosine phosphorylation of p41mapk and the change of the mobility of S6KII. Pretreatment of the cells with quin 2/AM inhibited almost completely the tyrosine phosphorylation of p41mapk induced by fMet-Leu-Phe, but only partially the change in mobility of S6KII. Under various conditions, near maximum conversion of S6KII was observed even if only about 40% of the maximum level of tyrosine phosphorylation of p41mapk was achieved. The results suggest that rapid modification of S6KII occurs in chemotactic factor-stimulated neutrophils. Furthermore, the modification of S6KII induced by fMet-Leu-Phe requires either only partial tyrosine phosphorylation of p41mapk or the activation of kinase(s) other than the p41mapk isoform.

Simultaneous determination of mercury speciation in biological materials by GC/CVAFS after ethylation and room-temperature precollection

We developed a method for the simultaneous determination of monomethyl mercury (MMHg), inorganic mercury [Hg(II)], and total mercury (THg) in biological materials. A variety of biological materials can be digested in methanolic KOH solution. The MMHg and Hg(II) present are converted to volatile ethyl derivatives, methylethyl mercury and diethyl mercury, by an aqueous-phase ethylation reaction with sodium tetraethylborate. The ethyl derivatives are precollected onto a trapping column at room temperature, in case of disconnection with the separation/detection system, and then thermally desorbed into a packed isothermal gas chromatography (GC) column. Eluted organo-Hg compounds from the GC column are decomposed into Hg0, and detection is completed by cold vapor atomic fluorescence spectrometry (CVAFS). Pure standard solutions can be used for calibration. The sum of MMHg and Hg(II) obtained by this method equals the THg value obtained by digestion with HNO3 and H2SO4, reduction with SnCl2, and single-stage amalgamation/CVAFS for all biological materials studied. Absolute detection limits are 0.6 pg and 1.3 pg of Hg as MMHg and Hg(II), respectively, corresponding to 0.3 ng and 0.6 ng/g (wet) of sample.

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.

Evidence for anti-Plasmodium falciparum antibodies that cross-react with human T-lymphotropic virus type I proteins in a population in Irian Jaya, Indonesia

This study was performed to demonstrate the presence of anti-Plasmodium falciparum antibodies in a population living in Irian Jaya, Indonesia that cross-react with human T-lymphotropic virus type I (HTLV-I) proteins. Serum samples from 63 volunteers living in Oksibil, a secluded highland valley in Irian Jaya, were tested for anti-P. falciparum antibodies by an immunofluorescence assay and for anti-HTLV-I antibodies by an enzyme immunoassay (EIA). All samples were positive for anti-P. falciparum antibodies at titers of > or = 1:256. Twenty-four samples were reactive by EIA for HTLV-I, and of these, 23 were tested by western blotting (immunoblotting). Five of the 23 samples were classified as western blot positive and 18 were classified as western blot indeterminate. In competitive blocking assays with malaria proteins, western blot immunoreactivity to all HTLV-I Gag proteins was either reduced or eliminated. Significant reductions in the HTLV-I EIA optical density values of the Oksibil sera occurred when the sera were competitively blocked with the malaria antigens. The optical density values of HTLV-I-positive control sera showed no significant change. Competitive blocking with HTLV-I antigens produced reductions in the optical density values of both the Oksibil sera and the HTLV-I-positive control sera. These data suggest that in this population, anti-P. falciparum antibodies are cross-reactive with HTLV-I proteins in the western blot and EIA tests.

Adrenergic regulation of aqueous outflow

Epinephrine increased outflow facility and cyclic AMP in the in vitro perfused human anterior segment with a maximal facility increase of 44% occurring at approximately 2 x 10(-5) M. Cyclic AMP measured in the perfusate from anterior segments increased by 12-14 fold after administration of 10(-5) M epinephrine. Both the facility increase and cyclic AMP rise were blocked by the beta-2 selective antagonist, ICI118,551. While there was a correlation between the facility increase and elevation in cyclic AMP levels, the rise in cyclic AMP preceded the facility increase by about 1 hour, suggesting that the ultimate effect of epinephrine involved a rather slow event such as synthesis and release of prostaglandins or protein synthesis. Subsequent perfusion studies showed that very large concentrations of indomethacin were necessary to block the outflow facility effect of epinephrine, suggesting that prostaglandin synthesis did not underlie the facility effect in this system. However, 5 x 10(-5) M cyclohexamide blocked the effect on outflow facility of both epinephrine and forskolin, but did not block the rise in cyclic AMP. These studies suggest that protein synthesis may play a role in the epinephrine-induced facility increase at some point beyond the second messenger level.