Transcriptional autorepression of the stress-inducible gene ATF3

Previously, we demonstrated that ATF3 (activating transcription factor-3) is a stress-inducible gene, and the protein it encodes is a transcriptional repressor. In this report, we present evidence suggesting that ATF3 represses the transcription of its own gene. Interestingly, efficient repression requires a consensus ATF/cAMP-responsive element site in the promoter and a previously unidentified ATF3-binding site immediately downstream from the TATA box. Although this new site resembles the known ATF/cAMP-responsive element sequences at the flanking sequence, it differs from them at the center key residues. These observations indicate that ATF3 can tolerate variations in the center of the binding sites if the flanking sequences are favorable. The repression of the ATF3 promoter by its own gene product provides a mechanistic explanation, at least in part, for the transient expression pattern of the ATF3 gene upon stress induction.

[Complications of massive allografts after segmental resection of malignant bone tumors]

OBJECTIVE

To analyze the postoperative complications of bone and joint allografting for the reconstruction of massive bone defect after the resection of malignant bone tumors and its management.

METHODS

Bone-joint allografting for the reconstruction of massive bone defect after the resection of malignant bone tumors with different internal fixations was performed in 106 patients with complete follow-up data. Bone healing time, complication rate, and final results in different allografts were compared. Operation indications, complications and internal fixation were also analyzed. The final results were determined according to the Mankin's standard.

RESULTS

Allografts Alcohol immersed were more susceptible to infection, non-union, etc. Allografts and combined prosthesis were superior to semi-articular transplantation. Complications included deep infection (10%), skin necrosis (12.2%), local recurrence (14.4%), and delayed union or non-union (15.6%). Dynamic interlocked intramedullary nailing was superior to conventional intramedullar nailing and compression plates.

CONCLUSIONS

Allografting is acceptable for the reconstruction of massive bone defect after tumor resection. Its results are encouraging after proper management of complications caused by surgical technique, internal fixation and soft tissue repair.

[Clinical significance on protruded nucleus pulposus: a comparative study of 44 patients with lumbar intervertebral disc protrusion and 73 asymptomatic control in tridimentional computed tomography]

OBJECTIVE

To probe the clinical significance of space occupation of lumbar protruded nucleus pulposus (PNP) in vertebral canal.

METHODS

Materials of tridimentional ultrathin scanning computed tomography (CT), plain and flexion-extension dynamic radiograph on lumbar spine in 44 patients of lumbar intervertebral disc protrusion and 73 asymptomatic subjects (as control, including 22 cases with PNP but without symptoms) were observed, analysed and compared in volume, surface area, relative space occupation of PNP inside spinal canal, structure deformation and mobility of lumbar spine, and their difference and relevance.

RESULTS

The rate of asymptomatic lumbar disc protrusion in the control group was up to 30.1%. The volume, surface area and relative space occupation of PNP inside spinal canal in the patients group were significantly higher than those in the control group. Although the structure was more deformed and mobility of lumbar spine more limited in the patients group before and after treatment than those in the control group, as compared with those subjects with asymptomatic PNP, the difference was insignificant.

CONCLUSION

(1) Relative space occupation of PNP inside spinal canal could be usually digested by compensation system of spinal column, however, there is no final conclusion reached about the limit of compensation system; (2) Relatively bigger PNP may reduce the structure compensation capability of lumbar spine, which will result, sometimes, in a mechanical disorder of lumbar spine and nerve root irritation.

Progressive increases in de novo methylation of CpG islands in bladder cancer

We conducted a quantitative analysis of the extent of de novo methylation of four CpG islands in human urinary transitional cell carcinomas of different stages and grades to determine how frequently these CpG islands became methylated in transition cell carcinomas during progression. The CpG islands included exon 5 of PAX6, exon 2 of p16, the 5' end of the deleted in bladder cancer gene, and the 5' end of transmembrane protein containing epidermal growth factor and follistatin domains. These sequences were not methylated in normal urothelial tissues; however, 48 of the 54 tumors examined (89%) showed methylation levels in excess of 20% for at least one of the markers. The number of markers concurrently methylated in individual tumors increased with the stage of the tumor, with several of the more aggressive invasive cancers showing hypermethylation of all four markers compared with the less aggressive invasive cancers. However, considerable methylation defects were present in superficial, preinvasive, papillary tumors. These data demonstrate that 89% of bladder cancers have increased methylation of CpG islands relative to their normal counterparts and suggest the occurrence of a hypermethylator phenotype in which multiple independent CpG islands become concurrently methylated in individual tumors in a process associated with tumor progression.

DNA methylator and mismatch repair phenotypes are not mutually exclusive in colorectal cancer cell lines

A potential link between DNA repair and de novo methylation of exogenous sequences in colorectal cancer cell lines suggested that cells deficient in mismatch repair (MMR-) had an increased ability to silence the introduced virus promoter by DNA methylation due to the presence of a methylator phenotype (MET+) (Lengauer et al., 1997a). We explored this relationship in more detail and found that although there was a clear difference in the abilities of MMR+ cells to express the viral promoter compared to their MMR- counterparts, this difference was not consistently explained by levels of methylation in the viral promoter. Furthermore, we were unable to distinguish differences between the levels of methylation of six endogenous known CpG islands or 100 random DNA fragments containing CCGG sites within the cells. No consistent differences between the abilities of the cells to methylate the CpG island in exon 2 of the p16 gene were observed after transient demethylation by 5-aza-2'-deoxycytidine nor in the levels of expression of three human methyltransferase enzymes. Our results do not therefore support the existence of mutually exclusive DNA methylation (MET) and DNA repair (MMR) phenotypes. Oncogene (2000) 19, 943 - 952.

Amido-(propyl and allyl)-hydroxybenzamidines: development of achiral inhibitors of factor Xa

The design, synthesis and SAR of amido-(propyl and allyl)-hydroxybenzamidine coagulation factor Xa inhibitors is described. These achiral inhibitors are selective for fXa vis a vis structurally related serine proteases and are readily prepared in 6-7 linear steps. The most potent member 9j (fXa Ki = 0.75 nM) is selective (>1000-fold) and an effective anticoagulant in mammalian plasma.

[Complete nucleotide sequence of the nonstructural gene of alphavirus YN87448 strain isolated in China and its relationship to other Sindbis viruses]

OBJECTIVE

To determine the complete nucleotide sequence of the nonstructural gene of YN87448 virus stain which was firstly isolated from a female patient with fever in Yunnan Province in 1986, and identified as a member of Alphavirus by the serological method.

METHODS

The complete nucleotide sequence of the nonstructural region gene of YN87448 virus strain was determined with nine clones, which were obtained by using reverse transcription and polymerase chain reaction (RT-PCR), and by linking nine overlapping fragments into pGEM-T vector respectively.

RESULTS

The complete nucleotide sequence of nonstructural gene of YN87448 virus strain was 7,613 nucleotides long exclusive of the 5' cap, encoding four nonstructural proteins, nsP1, nsP2, nsP3, nsP4, and contained one initiator(ATG) and two stop codons (TGA). In comparison with the consensus sequence of S.A.AR86, the homogeneity of the nucleotide sequence between YN87448 virus strain and sindbis-like virus isolate S.A.AR86 was 98.8%. YN87448 virus strain can not produce a fatal disease in adult mice. In comparison with the consensus sequence of S.A.AR86, there is a 54 nucleotide insertion from 5,256 bp to 5,309 bp, 3 nucleotide (AGT) deletion at 5,603 bp in nsP3 region, and an opal termination codon between the nsP3 and the nsP4 genes in YN87448. virus strain. This sequence has been put into Gene Bank and No. is AF103734.

CONCLUSION

YN87448 is a new sindbis-like virus strain.

Aminoisoquinolines: design and synthesis of an orally active benzamidine isostere for the inhibition of factor XA

The design, synthesis and SAR of sulfonamidopyrrolidinone fXa inhibitors incorporating a new benzamidine isostere, namely aminoisoquinolines, is described. These inhibitors have higher Caco-2 cell permeability than comparable benzamidines and attain higher levels of exposure upon oral dosing. The most potent member 14b (fXa Ki=6 nM) is selective against other serine proteases of interest (>600 fold).

Absorption distribution of an optical beam focused into a turbid medium

The focusing of light into a turbid medium was studied with Monte Carlo simulations. Focusing was found to have a significant effect on the absorption distribution in turbid media when the depth of the focal point (the distance between the focal point and the surface of the turbid media) was less than or comparable with the transport mean free path. Focusing could significantly increase the peak absorption and narrow the absorption distribution. As the depth of the focal point increased, the peak absorption decreased, and the depth of peak absorption increased initially but quickly reached a plateau that was less than the transport mean free path. A refractive-index-mismatched boundary between the ambient medium and the turbid medium deteriorated the focusing effect, increased the absorption near the boundary, lowered the peak absorption, and broadened the absorption distribution.

[Screening of acidic xylanase producing strain and studies on its enzyme production conditions]

From 150 fungal strains, the authors found 8 strains contained mainly of xylanase activity over 100 U/mL in which the No. 149 strain was the highest xylanase producer. Which tentatively identified as Aspergillas niger. The appropriate medium composition was as follows: wheat bran hemicellulose 4%; NaNO3 1%; wheat bran 1% prepared in Mandels nutritional solution without (NH4)2SO4 and urea. After cultivated in shake-flask at 28 degrees C-32 degrees C for 60 h, the activity reached the highest value of 357.2 U/mL. The optimum pH of xylanase was 4.6 and it was stable at pH3-11. The fermented broth of strain 149 contained in addition to xylanase (relative activity 100) also included amylase(1.8), mannanase(0.98), beta-xylosidase(0.94) and cellulase(0.17).

Isolation and identification of Mycoplasma genitalium from high risk populations of sexually transmitted diseases in China

OBJECTIVE

To investigate Mycoplasma genitalium (Mg) infection in high risk populations of sexually transmitted diseases (STDs) in China by means of culture, Mg-DNA detection, observation under an electron microscope (EM) and an atomic force microscope (AFM).

METHODS

227 urogenital specimens taken from both patients in clinics and high risk populations of STDs in Beijing, Nanjing and Shanghai areas were cultured in SP-4 medium for isolation of Mg. Suspicious positive strains were identified first by PCR technique which could amplify the special DNA fragments of Mg adhesion protein (Mg-Pa) and 16S-rRNA sequences. The morphologic features of Mg were observed under EM and AFM.

RESULTS

Eight strains were isolated from the 227 specimens, the total positive rate was 3.52%. The isolated strains met the criteria of growth and metabolic conditions required by Mg. Specific fragments of Mg-DNA (374 bp based on Mg-Pa and 402 bp on 16S-rRNA primers, respectively) could be amplified from both the isolates and the genital secretions. Under EM and AFM, Mg showed different shapes, including flask, pear, spindle and globe shape. The typical shape of Mg was flask or pear shape with projecting neck portion and broadened terminal structure under EM and with constrictive ring between the neck and body under AFM.

CONCLUSION

Mg infection exists in high risk populations of STDs in China. We highly suggest the use of AFM in dermatological study.

The human DNA methyltransferases (DNMTs) 1, 3a and 3b: coordinate mRNA expression in normal tissues and overexpression in tumors

DNA methylation in mammals is required for embryonic development, X chromosome inactivation and imprinting. Previous studies have shown that methylation patterns become abnormal in malignant cells and may contribute to tumorigenesis by improper de novo methylation and silencing of the promoters for growth-regulatory genes. RNA and protein levels of the DNA methyltransferase DNMT1 have been shown to be elevated in tumors, however murine stem cells lacking Dnmt1 are still able to de novo methylate viral DNA. The recent cloning of a new family of DNA methyltransferases (Dnmt3a and Dnmt3b) in mouse which methylate hemimethylated and unmethylated templates with equal efficiencies make them candidates for the long sought de novo methyltransferases. We have investigated the expression of human DNMT1, 3a and 3b and found widespread, coordinate expression of all three transcripts in most normal tissues. Chromosomal mapping placed DNMT3a on chromosome 2p23 and DNMT3b on chromosome 20q11.2. Significant overexpression of DNMT3b was seen in tumors while DNMT1 and DNMT3a were only modestly over-expressed and with lower frequency. Lastly, several novel alternatively spliced forms of DNMT3b, which may have altered enzymatic activity, were found to be expressed in a tissue-specific manner.

Novel endothelin B receptor transcripts with the potential of generating a new receptor

Using RT-PCR and rapid amplification of 5' cDNA ends (5' RACE), we have cloned three previously unrecognized endothelin B receptor (EDNRB) transcripts from a human melanoma cell line. Three distinct types of cDNAs (EDNRBDelta1, Delta2 and Delta3) were identified. EDNRBDelta1 starts upstream of the published transcription start site of hEDNRB without splicing, whereas, EDNRBDelta2 and EDNRBDelta3 are alternatively spliced. EDNRBDelta1 and EDNRBDelta2 share the same transcription initiation site and are 560bp upstream of the conventional hEDNRB, whereas that of EDNRBDelta3 is 939bp upstream from that described for the conventional hEDNRB. Interestingly, many transcription factor motifs are detectable in the upstream regions of these transcription initiation sites. The predicted amino acid sequences reveal that EDNRBDelta1 and EDNRBDelta2 produce the same protein as the conventional hEDNRB, but EDNRBDelta3 would give rise to additional in-frame 89- or 83-amino-acid residues at the N-terminus. EDNRBDelta3 generates the same amino acid sequence at the C terminus, but utilizes the polyadenylation signal within the open reading frame, resulting in a shorter 3'UTR. These transcripts are widely expressed in human tissues, but their expression patterns vary between different tissues.

[The target--gene expression of interleukin--12 in HepG2 cells]

EB virus vector pEBAF, which contains human alpha-fetoprotein gene promoter and enhancer was used as expression vector. Two recombinant expression vectors, pEBAF/P35 and pEBAF/P40, were constructed and co-transfected into 4 cell lines. RT-PCR suggested that both P35 and P40 mRNA are expressed in HepG2 cell secreting alpha-fetoprotein, in contrast, neither P35 mRNA nor P40m RNA was expressed in non-secreting alpha-fetoprotein cell lines. This proved that the pEBAF may lead to target--expression of IL-12 in hepatoma and has tissue specificity and exclusiveness for hepatoma. The cotransfected Hyg resistant clone of HepG2 cell was selected. Northern blot indicated that the HepG2 cell clone had transcription of P35 mRNA and P40 mRNA. Expression of IL-12 in the supernatant of HepG2 cell culture had been testified by ELISA and Western blot. IL-12 biological activity test indicated that the expressed IL-12 had activity of inducing IFN-gamma production. This research laid the foundation to develop an in vivo gene therapy strategy pointing to the treatment of hepatocellular carcinoma, with selective killing of the tumor cells and no effect on the normal hepatic cells.

DNA methylation differences associated with tumor tissues identified by genome scanning analysis

Most investigations on the role of DNA methylation in cancer have focused on epigenetic changes associated with known tumor suppressor genes. This may have led to an underestimation of the number of CpG islands altered by DNA methylation, since it is possible that a subset of unknown genes relevant to cancer development may preferentially be affected by epigenetic rather than genetic means and would not be identified as familial deletions, mutations, or loss of heterozygosity. We used a recently developed screening procedure (methylation-sensitive arbitrarily primed-polymerase chain reaction to scan genomic DNA for CpG islands methylated in white blood cells (WBCs) and in tumor tissues. DNA methylation pattern analysis showed little interindividual differences in the WBCs and normal epithelium (adjacent to colon, bladder, and prostate cancer cells), but with some tissue-specific differences. Cancer cells showed marked methylation changes that varied considerably between different tumors, suggesting variable penetrance of the methylation phenotype in patients. Direct sequencing of 8 of 45 bands altered in these cancers showed that several of them were CpG islands, and 2 of these sequences were identified in GenBank. Surprisingly, three of the bands studied corresponded to transcribed regions of genes. Thus, hypermethylation of CpG islands in cancer cells is not confined to the promoters of growth regulatory genes but is also found in actively transcribed regions.

Novel cyclic compounds as potent phosphodiesterase 4 inhibitors

The synthesis and biological activity of a novel series of 2, 2-disubstituted indan-1,3-dione-based PDE4 inhibitors are described. This structurally unique class of PDE4 inhibitors is markedly different from the known PDE4 inhibitors such as RP 73401 (2) and CDP 840 (3). Structure-activity relationship (SAR) studies led to the identification of inhibitors with nanomolar potency and oral activity in a murine endotoxemia model for TNF-alpha inhibition. Unlike other classical PDE4 inhibitors, several analogues were found to be nonemetic in a canine emesis model at intravenous doses of up to 3 mg/kg.

[Diagnostic significance of topical image of infrared thermograph on the patient with lumbar intervertebral disc herniation--a comparative study on 45 patients and 65 normal control]

OBJECTIVE

To analyse and explore the diagnostic significance of infrared thermography on the patients with lumbar intervertebral disc protrusion.

METHODS

Forty-five hospitalized cases under conservative treatment (mainly manipulation) and 65 controls were sequentially selected. Both groups were examined with infrared thermograph on lower back and lower extremities as well as physical examination before and after treatment. The study statistically analysed the temperature difference between the involved and healthy parts at different areas; and also compared the change of the temperature difference after the treatment to the decreasing scores of physical examination afterward.

RESULTS

The statistic result showed that the temperature difference between two sides on patients group was significantly higher than those of control group. The further analysis shows that the temperature difference at posterior femur area in the patient's group correlated significantly to the severity of clinical signs caused by nerve root irritation.

CONCLUSIONS

The thermograph could only be considered as a reference in the diagnosis of lumbar disc protrusion. It is helpful to discover the severity of radical signs according to the posterior femoral region of hypo- (or hyper) thermogram.

Characterization of human activating transcription factor 4, a transcriptional activator that interacts with multiple domains of cAMP-responsive element-binding protein (CREB)-binding protein

We demonstrate that human activating transcription factor 4 (hATF4), a member of the activating transcription factor/cAMP-responsive element-binding protein (ATF/CREB) family of transcription factors, is a potent transcriptional activator in both mammalian cells and yeast. The N-terminal 113 amino acids of hATF4 activate transcription efficiently, and unexpectedly, the C-terminal bZip DNA binding domain of hATF4 also activates transcription, albeit weakly. Our results indicate that hATF4 interacts with several general transcription factors: TATA-binding protein, TFIIB, and the RAP30 subunit of TFIIF. In addition, hATF4 interacts with the coactivator CREB-binding protein (CBP) at four regions: 1) the KIX domain, 2) a region that contains the third zinc finger and the E1A-interacting domain, 3) a C-terminal region that contains the p160/SRC-1-interacting domain, and 4) the recently identified histone acetyltransferase domain. Interestingly, both the N-terminal and C-terminal regions of hATF4 interact with the above general transcription factors and CBP, providing a mechanistic explanation for their ability to activate transcription. Consistent with its role as a coactivator, CBP potentiates the ability of hATF4 to activate transcription. The potential significance of the interaction between hATF4 and multiple factors is discussed.

Regioselective effect of zwitterionic DNA substitutions on DNA alkylation: evidence for a strong side chain orientational preference

The incorporation of zwitterionic residues (5-substituted omega-aminoalkyl-2'-deoxypyrimidines) into DNA has been reported to bend DNA as measured by aberrant gel mobility [Strauss et al. (1996) Proc. Natl. Acad. Sci. U.S.A. 93, 9515-9520]. Herein we report that DNA methylation by N-methyl-N-nitrosourea at N7-guanine is regioselectively inhibited by point substitutions of the zwitterionic residues 5-(6-aminohexyl)-2'-deoxycytidine, 5-(6-aminohexyl)-2'-deoxyuridine, or 5-(3-aminopropyl)-2'-deoxyuridine. No inhibition is observed for DNA methylation by dimethyl sulfate. On the basis of inhibition patterns for methylation with the different zwitterionic substitutions and the different length tethers, the omega-aminoalkyl side chains prefer to adopt a conformation that points them toward the 3'-base. Molecular modeling grid searches, coupled with energy minimizations, and simulated annealing molecular dynamics studies indicate that unfavorable steric interactions with the 5'-base and backbone, as well as stabilizing electrostatic interactions with electronegative atoms on the 3'-side, are responsible for the observed conformational preference. No evidence for association of the cationic side chain with the phosphate backbone is observed. The observed bending of DNA induced by the tethered ammonium ions may simply arise from their localization in the major groove.

[Limb salvage surgery using massive allografts in malignant bone tumors]

The advantages of segmental allografts over arthoplastics are, among others, secured biological healing, easy attachment of tendons and ligaments, and desirable long-tem results. Since 1983, the authors have performed 35 resections of malignant tumors in the extremities followed by reconstructions with implantation of segmental allografts. Five types of grafts were used for the reconstruction of the skeletal defects, intercalary hemicylinder, intercalary cylinder, partial osteoarticular, total osteoarticular, and allograft-prosthetic implant composite. All the patients underwent adjunctive chemotherapy that was considered necessary. The length of follow-up ranged from 6 months to 10 years during which time 6 patients died, 25 were disease-free, and 4 survived as tumors-carriers. Complications in 28.6% of the patients included infection, graft resorption, recurrence and nonunion. Patients undergoing intercalary grafts oblained better functional results than those having osteoarticular grafts. 4 patients had biopsies and bone scans of the grafts 2-4 years postoperation with creeping substituion being observed. Segmental allograft remains a viable approach with predictable results for reconstruction of skeletal defects after resection of malignant bone tumors.

[Experimental study on the antituberculous activity of ofloxacins]

OBJECTIVE

To compare the antituberculous activities of ofloxacins (OFLX) made by different pharmaceutical companies.

METHODS

The minimal inhibitory concentrations (MIC) of OFLX were determined by two-fold dilution method. The efficacy of OFLX was compared in terms of median survival time (ST50) against M. tuberculosis infection in mice.

RESULTS

In vitro the activities against M. tuberculosis (H37Rv), M. bovis (Ravenel) and M. Phlei products showed similar degree. The MICs of OFLX were 0.5-1.0 microgram/ml in modified Sauton medium and 1.0 microgram/ml in modified Lowenstin-Jensen medium. OFLX was more active than ethambutol (MIC 4-8 micrograms/ml, 2.0 micrograms/ml, respectively) against M. tuberculosis in the same media. OFLX from domestic or foreign drug companies showed similar results for treating M. tuberculosis infection in mice and all were significantly effective. The efficacy of OFLX at the dose of 4 mg per mouse was found close to that of ethambutol (EMB) at the dose of 2 mg per mouse. The efficacy of OFLX at the dose of 2 mg per mouse close to EMB at the dose of 1 mg per mouse and thiacetazone at the dose of 2 mg per mouse.

CONCLUSIONS

In vitro and in vivo, the activities of OFLX from different sources against M. tuberculosis are about the same.

Infiltration of eosinophils into the asthmatic airways caused by interleukin 5

Interleukin (IL)-5 is thought to play an important role in asthmatic bronchial mucosal inflammation and is a potential therapeutic target. To investigate the effect of IL-5 on the infiltration of eosinophils in airway in vivo, we compared eosinophil counts and their activation status in airways without and after the topical instillation of recombinant human IL-5. Eight subjects with mild atopic asthma underwent initial bronchoscopy during which control bronchoalveolar lavage (BAL) fluid as well as bronchial mucosa were obtained, and at the same time, normal saline and IL-5 were administered to two sublobar segments separately. The second bronchoscopy were carried out and samples from challenged sites were taken 24 h later. It was found that the total eosinophils (BMK-13+ cells) and the activated eosinophils (EG2+ cells) in bronchial mucosa, the eosinophil numbers in BAL fluid, as well as eosinophil cationic protein (ECP) in BAL fluid from saline-challenged segments were not different from those in unchallenged segments. However, a significant eosinophilia was observed in bronchial mucosa and BAL fluid from IL-5-challenged sites. Eosinophil activation, as assessed by secretion of ECP, was also increased significantly in bronchial mucosa and BAL fluid. The results strongly suggested that IL-5 is capable of inducing eosinophil infiltration into the asthmatic airways, as well as the activation of infiltrating eosinophils.

Identification and characterization of differentially methylated regions of genomic DNA by methylation-sensitive arbitrarily primed PCR

We have developed a simple and reproducible fingerprinting method for screening the genome for regions of DNA that have altered patterns of DNA methylation associated with oncogenic transformation. Restriction enzymes with different sensitivities to cytosine methylation in their recognition sites were used to digest genomic DNAs from primary tumors, cell lines, and normal tissues prior to arbitrarily primed PCR amplification. Fragments that showed differential methylation were cloned and sequenced after resolving the PCR products on high-resolution polyacrylamide gels. The cloned fragments were then used as probes for Southern analysis to confirm differential methylation of these regions in colon tissues and cell lines. Forty-four DNA fragments associated with a total of five different regions of genomic DNA containing methylation sites were detected in 10 matched sets of normal and tumor colon DNAs and 7 colon cancer cell lines. A novel CpG island was also isolated that was found to be frequently hypermethylated in bladder and colon tumors. We have demonstrated that this technique is a rapid and efficient method that can be used to screen for altered methylation patterns in genomic DNA and to isolate specific sequences associated with these changes.

Studies on multiple forms of maltotetraose-forming amylase from Alcaligenes sp

Zymograms of the cultural supernatant of Alcaligenes sp. showed three bands, the major one being G4A-1 and the minor two, G4A-2 and G4A-3. Based on the electrophoretic homogeneity of the purified three bands and the enzymatic activities identified by a thin layer chromatography of the soluble starch hydrolysates, all the three bands were confirmed to be maltotetraose-forming amylase but in multiple forms. Neither glycosidase nor protease activities could be detected in the culture (only very weak protease activities were observed at 48 hours after cultivation), which indicate that the two enzymes were not involved in the amylase multiple-form formation. Only the relative amount of the two minor bands (but not the multiple-form pattern) was changed when the initial pH of the medium varied from 6.5-8.5. An addition of 0.3% glucose raised the yield of G4A-2 and G4A-3.

Ultrastructural study on pronuclear development in fertilized eggs from goldfish, Carassius auratus

The formation of male and female pronuclei in physiologically monospermic fertilized eggs of the goldfish, Carassius auratus, has been investigated with transmission electron microscopy. Ultrastructural observations show that at 26°C the transformation of the sperm nucleus takes place very quickly. The sperm nuclear envelope degenerates and is replaced by a large number of smooth surface vesicles 1 min post-insemination. Concomitantly, most of the condensed sperm chromatin is dispersed and is surrounded by vesicles. Dispersion of the chromatin is followed by the fusion of vesicles and the formation of a new bilaminar pronuclear envelope. Within 5-10 min post-insemination, a spheroid male pronucleus with intranuclear annulate lamellae is produced. The formation of a female pronucleus is slightly different to that of the male pronucleus. The dispersing chromatin of the egg is divided into many groups, most of which are surrounded by multilaminar envelopes 5 min post-insemination. An ellipsoid female pronucleus with a continuous bilaminar pronuclear envelope and intranuclear annulate lamellae is formed 15 min post-insemination. Subsequently, the two pronuclei migrate towards one another. When the fully developed male and female pronuclei are located in the center of the blastodisc, each changes itself into a saccular complex 25 min post-insemination.

ATF3 gene. Genomic organization, promoter, and regulation

ATF3 gene, which encodes a member of the activating transcription factor/cAMP responsive element binding protein (ATF/CREB) family of transcription factors, is induced by many physiological stresses. As a step toward understanding the induction mechanisms, we isolated the human ATF3 gene and analyzed its genome organization and 5'-flanking region. We found that the human ATF3 mRNA is derived from four exons distributed over 15 kilobases. Sequence analysis of the 5'-flanking region revealed a consensus TATA box and a number of transcription factor binding sites including the AP-1, ATF/CRE, NF-kappa B, E2F, and Myc/Max binding sites. As another approach to understanding the mechanisms by which the ATF3 gene is induced by stress signals, we studied the regulation of the ATF3 gene in tissue culture cells by anisomycin, an approach that has been used to study the stress responses in tissue culture cells. We showed that anisomycin at a low concentration activates the ATF3 promoter and stabilizes the ATF3 mRNA. Significantly, co-transfection of DNAs expressing ATF2 and c-Jun activates the ATF3 promoter. A possible mechanism implicating the C-Jun NH2-terminal kinase/stress-activated protein kinase (JNK/SAPK) stress-inducible signaling pathway in the induction of the ATF3 gene is discussed.

Reaction of N-(2-chloroethyl)-N-nitrosoureas with DNA: effect of buffers on DNA adduction, cross-linking, and cytotoxicity

N-(2-Chloroethyl)nitrosoureas (CNU) are clinically used anticancer drugs whose cytotoxicity is associated with the generation of DNA interstrand cross-links. While studying the sequence selectivity for a series of CNU, a dramatic increase in the formation of N7-alkyldeoxyguanosine was observed when Tris buffer was used rather than phosphate or cacodylate buffers. Moreover, the formation of N7-alkyldeoxyguanosine lesions continues in Tris long after all of the CNU has hydrolyzed. These effects are not seen with the monofunctional alkylating analogues, e.g., N-methyl- and N-(2-hydroxyethyl)-N-nitrosourea. In order to determine if the nature of the CNU-mediated DNA damage was altered by Tris, studies were initiated on the following: (1) alkylation of N7-G in end-labeled DNA restriction fragments; (2) covalent modification of DNA with [ethyl-3H]-N-(2-chloroethyl)-N-nitrosourea; and (3) cytotoxicity in L1210 cells. The data presented demonstrate that Tris increases the yield of the "normal" CNU monofunctional cross-linked adducts, i.e., N7-(2-hydroxyethyl)deoxyguanosine, N7-(2-chloroethyl)deoxyguanosine, O6-(2-chloroethyl)deoxyguanosine, and bifunctional adducts, i.e., 1-(deoxycytid-3-yl)-2-(deoxyguanosin-1-yl)ethane and 1,2-bis(deoxyguanosin-7-yl)ethane. In addition, CNU appears to react with Tris to give a long-lived alkylating intermediate that affords large amounts of DNA adducts not seen with CNU in the absence of Tris. However, in vivo toxicity of CNU in L1210 cells is not affected by the presence of Tris, indicating that the reaction pathway(s) responsible for cross-linking is not significantly sensitive to the nature of the buffer.

[Four cases of similar Hexheimer's reaction during the initial chemotherapy for tuberculosis bacillus]

In the report, 4 patients with similar Hexheimer's reaction during initial chemotherapy for pulmonary tuberculosis were presented. The literatures on clinical manifestations, predisposing factors, pathogenic mechanism, pathological changes, diagnosis and management of Hexheimer's reaction are reviewed.

[Effects of a platelet-activating factor antagonist ONO-6240 on antigen induced eosinophil infiltration into the airways]

An in vivo mouse model of allergic bronchial asthma was developed to investigate the effects of a platelet activating factor antagonist ONO-6240 on eosinophil (EOS) recruitment into the mouse airway. In the present study, no EOS could be found in bronchoalveolar lavage fluid (BALF) from normal control mice. However, chronic ovalbumin challenge of sensitized mice induced significant bronchoalveolar eosinophilia (9.68 +/- 0.72 x 10(8)/L). In three groups of mice treated intraperitoneally with different doses of ONO-6240 (0.1, 1.0, 10.0 mg/kg), the medication produced 42.1% (5.60 +/- 0.97 x 10(8)/L, P < 0.01), 58.8% (3.99 +/- 0.84 x 10(8)/L, P < 0.01), and 72.6% (2.65 +/- 0.71 x 10(8)/L, P < 0.01) inhibition, respectively, of the antigen-induced influx of EOS into BALF. It was found that the prevention of EOS infiltration into airway with ONO-6240 was accompanied by decrements of both interleukin (IL)-5 and IL-2 levels. These data indicated that ONO-6240 prevented airway eosinophilia by inhibiting production of IL-5 and IL-2. Our results suggested that ONO-6240 may be of value in treating human asthmatic patients.

[The clinical study of local treatment of ocular malignant tumors with IL-2 LAK cells]

The authors reported the method of treatment of ocular malignant tumors at early and middle stages with local injections of self lymphokine-activated killing (LAK) cells which were induced by gamma IL-2 in vitro. Satisfactory therapeutic results were obtained. Among the 25 cases of ocular malignant tumors, 10 cases were treated only with IL-2 LAK cells, nine of them got complete regression (CR) and one got partial regression (PR); the other 15 cases were treated with operation and IL-2 LAK cells and they all obtained complete remission. In the follow-up, except the contact of 1 case with PR was lost, all the other 24 cases did not relapse after 1-5 years of observation. The above results show that the treatment of malignant tumors with local injection of self IL-2 LAK cells is a very effective immunotherapy.

CCAAT-box contributions to human thymidine kinase mRNA expression

In order to examine the role of two inverted CCAAT boxes near the start of transcription of the human thymidine kinase (TK) gene, a series of constructs were prepared in which one or both CCAAT boxes were deleted or mutated. These altered promoters (1.2 kb of 5'-flanking sequence) were used to express a TK minigene containing the first two exons and introns followed by the remainder of the cDNA. RNA blots were prepared from stable cell lines of ts13 cells containing these constructs under three conditions: 1) serum deprived cells, 2) serum stimulated cells, and 3) cells that had been stimulated with serum, but were arrested in the G1 phase of the cell cycle by the temperature sensitive mutation carried by these cells. TK mRNA expression from each construct was suppressed by the temperature sensitive block to cell cycle progression. Measurement of protein expression from the various altered TK promoters indicated that both CCAAT boxes contribute to promoter strength. These experiments also suggested that the two CCAAT boxes were not equivalent and that the distal CCAAT could substitute for the proximal CCAAT, but the converse was not true.

Localization of a cycloheximide-sensitivity response element in the human thymidine kinase gene promoter

In order to localize the segment of the human thymidine kinase (TK) gene promoter that mediates sensitivity of TK mRNA expression to the presence of cycloheximide (CX), a series of promoter truncation mutants was prepared between the 460-base pair (bp) promoter that was demonstrated previously to be sensitive to CX and the 83-bp promoter that was demonstrated previously to be insensitive to CX. TK promoters containing 370, 300, 160, or 130 bp of 5'-flanking sequence were all sensitive to inhibition by CX. Further truncation to 100 bp of 5'-flanking sequence eliminated CX sensitivity. Electrophoretic mobility shift assays using a probe containing most of this region (but omitting the SP1 binding site at the 5'-end of the 130-bp promoter) identified some complexes whose formation was sensitive to the presence of CX. Comparison of the sequences of oligonucleotides that were able to compete for formation of mobility shift complexes identified the sequence GCGGCC as a putative CX-sensitivity response element. Two such sequences are found between 83 and 130 bp 5' of the TK capsite. Mutation of the distal sequence attenuated sensitivity of TK mRNA expression to CX, while mutation of the proximal sequence had minimal effect on CX sensitivity. Thus, these data have localized a CX-sensitivity response element to a segment of TK promoter about 120 bp 5' of the capsite that includes the hexamer GCGGCC.

Protein that binds to the distal, but not to the proximal, CCAAT of the human thymidine kinase gene promoter

Mobility shift assays were used to examine protein binding to the human TK gene CCAAT boxes. Similar protein binding patterns were observed with probes containing either the proximal or distal CCAAT. However, probes containing both CCAAT boxes in which one of the CCAAT boxes was inactivated by mutation did not demonstrate identical binding patterns. One of the complexes formed with the longer probes was only observed when the distal CCAAT was intact. This species was not formed with probes that only contained an intact proximal CCAAT, and its formation could only be competed by oligonucleotides containing the distal CCAAT motif. This observation reveals the existence of a protein that can bind to the distal, but not to the proximal, CCAAT of the human TK promoter. This protein may account for the previous observation that the two CCAAT motifs are not functionally equivalent. The protein that binds to the distal, but not to the proximal, CCAAT (DTK-CBP) was also present in two human cell lines. Significantly more DTK-CBP was present in nuclear extracts of HepG2 and WI38 cells than in TK-ts13 cells. However, this protein was not observed in three different murine cell lines and one primary culture. Its abundance in some human cell lines suggests it might modulate the expression of human TK mRNA in cells that express this protein.

The use of 2-hydroperoxytetrahydrofuran as a reagent to sequence cytosine and to probe non-Watson-Crick DNA structures

2-Hydroperoxytetrahydrofuran (THF-OOH) can be employed to sequence cytosine (C) and to probe for non-canonical DNA structures involving C. Using 32P-labeled oligomers and a DNA restriction fragment, it is demonstrated that THF-OOH has a strong preference for Cs in single-stranded (s-s) DNA regions, and in bulges, loops and mismatches. The reactivity of C is diminished below pH 6.0, but is not affected by substitution of 5-methylcytosine. To demonstrate the utility of the reagent, it is directly compared to methoxylamine and chloroacetaldehyde, two other reagents commonly used to chemically probe C residues in non-Watson-Crick DNA structures.

[Clinical behavior and cytobiological activity of desmoid tumor]

Desmoid tumor, characterized by aggressive growth and frequent recurrence without metastasis after excision, remains to be a poorly understood neoplasm. In seventeen patients with desmoid tumor of the extremities, the relationship between the cytobiological activity and prognosis of desmoid tumor was studied by reviewing clinical material, histologic examination, statistical analysis of Ag-NORs, and morphometry of tumor cell nuclei in comparison with those of fibrosarcoma and soft tissue fibroma. The results showed that the cells of desmoid tumor were highly proliferative with their biological activity bearing resemblance to fibrosarcoma. Thus we have good grounds for grouping desmoid tumors as of low grade malignancy. We believe that initial surgical resection with a wide margin is the key for good prognosis because a lower recurrence rate will result.

Dermatologic consultations in the hospital setting

BACKGROUND AND DESIGN

Dermatologic practice occurs mainly in the outpatient setting. The reasons for, frequency, and impact of inpatient dermatologic consultation are largely unstudied. In this report, we prospectively studied dermatologic consultation in the major teaching hospital complex of a medical school. Over a period of 8 months, we prospectively recorded the demographics of the patients for whom consultation was requested, the provisional dermatologic diagnosis of the referring service, the final diagnosis of the dermatologic service, and the tests necessary to arrive at a final diagnosis.

RESULTS

During a period of slightly over 8 months, dermatologic consultation was requested and delivered to 591 patients who were either hospitalized or being evaluated in the emergency department or other urgent care settings. The services requesting consultation most frequently were medicine (39%), pediatrics (14%), surgery (12%), psychiatry (6%), and neurology (3%). In 51% of consultations, the patients were younger than 45 years of age. Diagnostic tests, including Tzanck smear and potassium hydroxide preparation, confirmed the clinical diagnosis in up to 50% of cases. Dermatologic consultation changed dermatologic diagnosis and treatment in more than 60% of the patients. Generally, the dermatologic diagnoses most frequently missed by the referring service were common conditions with established treatment.

CONCLUSIONS

Dermatologic consultation in the hospital setting improves dermatologic diagnosis and has an impact on treatment.

ATF3 and ATF3 delta Zip. Transcriptional repression versus activation by alternatively spliced isoforms

ATF3 is a member of the mammalian activating transcription factor/cAMP responsive element binding protein (ATF/CREB) family of transcription factors. In this report, we demonstrate that, contrary to the implication of its name, ATF3 represses rather than activates transcription from promoters with ATF sites. We also present evidence suggesting that one possible mechanism by which ATF3 represses transcription is to stabilize inhibitory co-factors at the promoter. In addition, we describe a naturally occurring, alternatively spliced, form of ATF3: ATF3 delta Zip. ATF3 delta Zip lacks the leucine zipper domain and does not bind to DNA. In contrast to ATF3, ATF3 delta Zip stimulates transcription, presumably by sequestering inhibitory co-factors away from the promoter. It is possible that ATF3 delta Zip is a physiologically important regulator and that it, together with ATF3, regulates the expression of specific target genes.

Gas chromatographic-mass spectrometric method for determination of anabasine, anatabine and other tobacco alkaloids in urine of smokers and smokeless tobacco users

A selected ion monitoring method for determination of the tobacco alkaloids anabasine, anatabine, nornicotine, metanicotine, dihydrometanicotine, and 2,3'-bipyridyl in urine of smokers and smokeless tobacco users is described. The method involves conversion of the secondary amine alkaloids to tertiary amine derivatives by reductive alkylation using an aldehyde and sodium borohydride, and chromatography on a 5% phenylmethylsilicone capillary column. These derivatives have good chromatographic properties, allowing determination of concentrations as low as 1 ng/ml. The alkaloid 2,3'-bipyridyl is unaffected by the derivatization procedure and may be determined simultaneously with the other alkaloids. The structural analogues 2-(3-pyridyl)hexahydroazepine, 5-methyldihydrometanicotine, and 6-methyl-2,3'-bipyridyl were synthesized for use as internal standards. Using the method, concentrations and 24 h excretion of anabasine, anatabine, and nornicotine in urine of twenty-two smokers, eight chewing tobacco users, and six oral snuff users were determined and compared with concentrations and excretion of nicotine and its metabolite cotinine. Excretion of nicotine and cotinine was similar in all tobacco users, but excretion of anabasine, anatabine and nornicotine was substantially greater in urine of smokeless tobacco users, presumably due to absence of pyrolysis of these alkaloids in smokeless tobacco products.

Prevalence and epidemiologic correlates of sexually transmitted Chlamydia trachomatis infection in a selected population

The incidence of Chlamydia trachomatis genitourinary infection was found by enzyme immunoassay antigen detection to be 10.0% in patients attending a sexually transmitted disease (STD) clinic, 3.0% in clients visiting an obstetrics-gynecology clinic, 20.8% in female prostitutes, and 1.3% in sexually active men. Predisposing factors for chlamydial infection were young age, multiple sexual partners, history of STDs, and coinfection with other STDs. Abnormal vaginal discharge and cervices in women, but not urethral manifestations in men, were significantly associated with chlamydial infection. Urethral gram stain had a certain value in identifying men infected with C. trachomatis.

[Clinical observation of immunotherapy in ocular malignant tumors with lymphokine-activated killing (LAK) cell]

In this paper, the authors reported the method of treating ocular malignant tumors with lymphokine-activated killing cells which were induced by rIL-2 in vitro. Among the sixteen cases of ocular tumors, 4 cases of 5 base cell carcinoma (1 case of which was partially extinctive), 4 cases of tarsal gland carcinoma, 2 cases of squamous cell carcinoma and respectively 1 case of retinoblastoma, non-Hodgkin's lymphoma, intraorbital hemangiopericytoma, intraorbital fibrous histiocytomas and hidradenocarcinoma were completely extinctive. The result shows that the immunotherapy method is effective.

Estimates and determinants of valid self-reports of musculoskeletal disease in the elderly

This study examined the extent and nature of bias associated with self-reported versus standardized physician-examination/assessment-based accounts of musculoskeletal disease in a sample of 406 persons chosen to represent an aging and dependency continuum. Prevalence of musculoskeletal disease based on standardized physician examination/assessments was 97%. Using the standardized findings as the criterion, the self-report underestimated prevalence by 16%. Overall, the results indicated that self-reports of musculoskeletal conditions by the elderly capture the vast majority of persons with painful or functionally significant disease and are most valid for persons from ages 65 to 74 but do not reflect the presence of asymptomatic joint pathology. Standardized physician examinations/assessments would more accurately determine the presence of risk factors in epidemiological studies of musculoskeletal disability.