Photophysical properties of long rodlike meso-meso-linked zinc(II) porphyrins investigated by time-resolved laser spectroscopic methods

The molecular design of directly meso-meso-linked porphyrin arrays as a new model of light-harvesting antenna as well as a molecular photonic wire was envisaged to bring the porphyrin units closer for rapid energy transfer. For this purpose, zinc(II) 5,15-bis(3,5-bis(octyloxy)phenyl)porphyrin (Z1) and its directly meso-meso-linked porphyrin arrays up to Z128 (Zn, n represents the number of porphyrins) were synthesized. The absorption spectra of these porphyrin arrays change in a systematic manner with an increase in the number of porphyrins; the high-energy Soret bands remain at nearly the same wavelength (413-414 nm), while the low-energy exciton split Soret bands are gradually red-shifted, resulting in a progressive increase in the exciton splitting energy. The exciton splitting is nicely correlated with the values of cos[pi/(N + 1)] according to Kasha's exciton coupling theory, providing a value of 4250 cm(-1) for the exciton coupling energy in the S(2) state. The increasing red-shifts for the Q-bands are rather modest. The fluorescence excitation anisotropy spectra of the porphyrin arrays show that the photoexcitation of the high-energy Soret bands exhibits a large angle difference between absorption and emission dipoles in contrast with the photoexcitation of the low-energy exciton split Soret and Q-bands. This result indicates that the high-energy Soret bands are characteristic of the summation of the individual monomeric transitions with its overall dipole moment deviated from the array chain direction, while the low-energy Soret bands result from the exciton splitting between the monomeric transition dipoles in line with the array chain direction. From the fluorescence quantum yields and fluorescence lifetime measurements, the radiative coherent length was estimated to be 6-8 porphyrin units in the porphyrin arrays. Ultrafast fluorescence decay measurements show that the S(2) --> S(1) internal conversion process occurs in less than 1 ps in the porphyrin arrays due to the existence of exciton split band as a ladder-type deactivation channel, while this process is relatively slow in Z1 (approximately 1.6 ps). The rate of this process seems to follow the energy gap law, which is mainly determined by the energy gap between the two Soret bands of the porphyrin arrays.

The equine herpesvirus 1 immediate-early protein interacts with EAP, a nucleolar-ribosomal protein

The equine herpesvirus 1 (EHV-1) immediate-early (IE) phosphoprotein is essential for the activation of transcription from viral early and late promoters and regulates transcription from its own promoter. The IE protein of 1487 amino acids contains a serine-rich tract (SRT) between residues 181 and 220. Deletion of the SRT decreased transactivation activity of the IE protein. Previous results from investigation of the ICP4 protein, the IE homolog of herpes simplex virus 1 (HSV-1), revealed that a domain containing a serine-rich tract interacts with EAP (Epstein-Barr virus-encoded small nuclear RNA-associated protein), a 15-kDa nucleolar-ribosomal protein (R. Leopardi, and B. Roizman, Proc. Natl. Acad. Sci. USA 93, 4572-4576, 1996). DNA binding assays revealed that (i) glutathione S-transferase (GST)-EAP disrupted the binding of HSV-1 ICP4 to its cognate DNA in a dose-dependent manner, (ii) GST-EAP interacted with the EHV-1 IE protein, but did not disrupt its binding to its cognate site in viral DNA. GST-pulldown assays indicated that the SRT of the IE protein is required for physical interaction with EAP. The IE protein and EAP colocalized in the cytoplasm of the infected equine ETCC cells at late times of the infection cycle. This latter finding may be important in EHV-1 gene regulation since late viral gene expression is greatly influenced by the EICP0 trans-activator protein whose function is antagonized by the IE protein.

Genome-wide analysis of developmental and sex-regulated gene expression profiles in Caenorhabditis elegans

We have constructed DNA microarrays containing 17,871 genes, representing about 94% of the 18,967 genes currently annotated in the Caenorhabditis elegans genome. These DNA microarrays can be used as a tool to define a nearly complete molecular profile of gene expression levels associated with different developmental stages, growth conditions, or worm strains. Here, we used these full-genome DNA microarrays to show the relative levels of gene expression for nearly every gene during development, from eggs through adulthood. These expression data can help reveal when a gene may act during development. We also compared gene expression in males to that of hermaphrodites and found a total of 2,171 sex-regulated genes (P < 0.05). The sex-regulated genes provide a global view of the differences between the sexes at a molecular level and identify many genes likely to be involved in sex-specific differentiation and behavior.

Quantification of proteinuria in children using the urinary protein-osmolality ratio

A prospective study was conducted to determine the correlation of early morning urinary protein/osmolality ratio (mg/l/mosmol/kg) with 24-h urinary protein excretion (mg/m2/day). Study patients consisted of 53 children (aged 1 month to 15 years). Early morning urine samples and 24-h urine samples were collected and analyzed. In group 1 (children without proteinuria), early morning urinary protein/creatinine ratio (Uprot/Ucr, mg/mg) was 0.061 +/- 0.011 and the protein/osmolality ratio (Uprot/Uosm, mg/l/mosmol/kg) was 0.073 +/- 0.014. Twenty-four hour urinary protein excretion in group 1 had no significant correlation with Uprot/Ucr or Uprot/Uosm. In group II (children with proteinuria), Uprot/Ucr was 5.78 +/- 1.10 and Uprot/Uosm was 4.42 +/- 1.34. Twenty-four hour urinary protein excretion in group 2 was 1483.6 +/- 303.7 mg/m2/day and its correlation with both Uprot/Uosm and Uprot/Ucr was highly significant (r = 0.87, P < 0.001 and r = 0.88, P < 0.001, respectively). The accepted nephrotic level of proteinuria of 40 mg/m2/h coincides with a Uprot/Uosm ratio of 1.9. In conclusion, early morning urinary Uprot/Uosm is a simple and potentially useful test for 24-h urinary protein excretion, and possibly could be used safely for the assessment of the degree of proteinuria in children.

The detection of p53 gene mutation using a microdissection technique in primary intracranial germ cell tumors

Using a microdissection technique, the contribution of the p53 mutation to tumorigenesis and prognosis in each histological subtype of the intracranial germ cell tumors (GCTs) was evaluated. Nineteen patients had primary intracranial GCTs, including 4 germinomas (GEs), 4 teratomas (TEs), 1 mixed tumor of GE and TE, and 10 mixed GCTs containing non-germinomatous malignant germ cell tumors (NG-MGCTs). After microdissection of specific subtypes, genomic DNA was screened for mutations in exons 5-8 of the p53 gene, using the dideoxyfingerprinting (ddF) followed by direct DNA sequencing. The direct sequencing revealed a total of six mutations in PCR products derived from the five cases (26%) which showed mobility shifts in ddF. Among the six mutations detected, four were missense mutations and two were silent. Missense mutations of the p53 gene tended to occur more frequently in the NG-MGCT component than in the GE or TE components (3/15 vs. 1/12 vs. 0/13). The incidence of missense mutations was not different between the survivors (3/13) and the deceased (1/6). This study suggests the possible role of the p53 gene in the tumori-genesis of NG-MGCT. However, p53 gene mutation did not correlate with the prognosis of NG-MGCT.

Direct detection and magnetic isolation of Chlamydia trachomatis major outer membrane protein-specific CD8+ CTLs with HLA class I tetramers

We recently identified HLA class I-presented epitopes in the major outer membrane protein (MOMP) of Chlamydia trachomatis that elicit CTL responses in human genital tract infections. T cells possessing cytolytic activities specific for these epitopes could be detected following in vitro stimulation of peripheral blood CD8(+) T cells with peptides. In the present study we used HLA-A2 tetramers for detailed characterization of MOMP-specific CTL responses. Ex vivo tetramer analysis detected MOMP-specific T cells in the peripheral blood of infected individuals at significant frequencies (0.01-0.20% of CD8(+) T cells). After in vitro stimulation with peptides, the frequencies of MOMP peptide-specific T cells increased up to 2.34% of CD8(+) T cells in bulk cultures. In contrast, HLA-A2/MOMP tetramer-binding T cells were virtually undetectable in the peripheral blood from uninfected individuals, either ex vivo or after 3 wk of in vitro peptide stimulation of their T cells. Magnetically sorted, tetramer-bound T cells specifically lysed peptide-pulsed targets as well as C. trachomatis-infected epithelial cells with nearly 50-fold greater per cell efficiency than that of unsorted populations. This study provides conclusive evidence of in vivo induction of HLA class I-restricted CD8(+) CTL responses to C. trachomatis MOMP. Direct detection of these cells with tetramers will allow their further characterization without prior manipulation and facilitate monitoring of CTL responses during infections and in immunization trials with MOMP-based vaccines.

Defining the atherogenicity of large and small lipoproteins containing apolipoprotein B100

Apo-E-deficient apo-B100-only mice (APOE:(-/-)APOB:(100/100)) and LDL receptor-deficient apo-B100-only mice (LDLR:(-/-)APOB:(100/100)) have similar total plasma cholesterol levels, but nearly all of the plasma cholesterol in the former animals is packaged in VLDL particles, whereas, in the latter, plasma cholesterol is found in smaller LDL particles. We compared the apo-B100-containing lipoprotein populations in these mice to determine their relation to susceptibility to atherosclerosis. The median size of the apo-B100-containing lipoprotein particles in APOE:(-/-)APOB:(100/100) plasma was 53.4 nm versus only 22.1 nm in LDLR:(-/-)APOB:(100/100) plasma. The plasma levels of apo-B100 were three- to fourfold higher in LDLR:(-/-)APOB:(100/100) mice than in APOE:(-/-)APOB:(100/100) mice. After 40 weeks on a chow diet, the LDLR:(-/-)APOB:(100/100) mice had more extensive atherosclerotic lesions than APOE:(-/-)APOB:(100/100) mice. The aortic DNA synthesis rate and the aortic free and esterified cholesterol contents were also higher in the LDLR:(-/-)APOB:(100/100) mice. These findings challenge the notion that all non-HDL lipoproteins are equally atherogenic and suggest that at a given cholesterol level, large numbers of small apo-B100-containing lipoproteins are more atherogenic than lower numbers of large apo-B100-containing lipoproteins.

Effect of vinorelbine, ifosfamide, and cisplatin combination chemotherapy in advanced non-small-cell lung cancer

Cisplatin-based chemotherapy is being tried in the treatment of nonoperable cases of non-small-cell lung cancer (NSCLC). However, the prognosis is unfavorable and to improve survival, clinical studies using various combinations of a variety of drugs as well as experimental material are in progress. We compared the efficacy and toxicities of combination chemotherapy using different doses of vinorelbine and ifosfamide with a constant dose of cisplatin in this study. Patients diagnosed with inoperable stage III or IV NSCLC between June 1997 and December 1998 were included. Cisplatin was administered at a constant dose of 80 mg/m2 on day 5, whereas vinorelbine on days 1 and 5 and ifosfamide on day 5 were administered in one of two different doses. In arm A, vinorelbine 25 mg/m2 and ifosfamide 3.0 g/m2 were administered. In arm B, vinorelbine 20 mg/m2 and ifosfamide 2.5 g/m2 were administered. Also, we reviewed for phase II and III studies that test 1) cisplatin, 2) vinorelbine monotherapy, and 3) vinorelbine/cisplatin/ifosfamide combination chemotherapy for stage IIIb-IV non-SCLC. Summation dose intensity (SDI) was calculated in each published and current study. Twenty patients in arm A and 35 patients in arm B were available for evaluation. There was no difference in patient activity, pathologic diagnosis, and differentiation or stage between the two arms. The median number of cycles was four in both arms. The response rate was 50% in arm A and 30% in arm B. The median survival times for arm A and B were 40 and 42 weeks, respectively, whereas the SDI was 1.94 and 1.7, respectively. More than grade III leukopenia was observed in 28.9% in arm A, which is more frequent than the 17.2% in arm B. There was a significant correlation between the SDIs and response rates and median survival (r2 = 0.629, p = 0.001; r2 = 0.453, p = 0.001, respectively). Although the follow-up period is relatively short, the survival time was similar in both arms. Because a high response rate may not be followed by a high survival time in combination chemotherapy of NSCLC, further studies on the appropriate dose of individual agents with regard to the relationship between response rate, severity, and incidence of toxicities and survival rate should be carried out.

Regulation of pancreas development by hedgehog signaling

Pancreas organogenesis is regulated by the interaction of distinct signaling pathways that promote or restrict morphogenesis and cell differentiation. Previous work has shown that activin, a TGF(beta+) signaling molecule, permits pancreas development by repressing expression of Sonic hedgehog (Shh), a member of the hedgehog family of signaling molecules that antagonize pancreas development. Here we show that Indian hedgehog (Ihh), another hedgehog family member, and Patched 1 (Ptc1), a receptor and negative regulator of hedgehog activity, are expressed in pancreatic tissue. Targeted inactivation of Ihh in mice allows ectopic branching of ventral pancreatic tissue resulting in an annulus that encircles the duodenum, a phenotype frequently observed in humans suffering from a rare disorder known as annular pancreas. Shh(−)(/)(−) and Shh(−)(/)(−) Ihh(+/)(−) mutants have a threefold increase in pancreas mass, and a fourfold increase in pancreatic endocrine cell numbers. In contrast, mutations in Ptc1 reduce pancreas gene expression and impair glucose homeostasis. Thus, islet cell, pancreatic mass and pancreatic morphogenesis are regulated by hedgehog signaling molecules expressed within and adjacent to the embryonic pancreas. Defects in hedgehog signaling may lead to congenital pancreatic malformations and glucose intolerance.

Protruding vulva mutants identify novel loci and Wnt signaling factors that function during Caenorhabditis elegans vulva development

The Caenorhabditis elegans vulva develops from the progeny of three vulval precursor cells (VPCs) induced to divide and differentiate by a signal from the somatic gonad. Evolutionarily conserved Ras and Notch extracellular signaling pathways are known to function during this process. To identify novel loci acting in vulval development, we carried out a genetic screen for mutants having a protruding-vulva (Pvl) mutant phenotype. Here we report the initial genetic characterization of several novel loci: bar-1, pvl-4, pvl-5, and pvl-6. In addition, on the basis of their Pvl phenotypes, we show that the previously identified genes lin-26, mom-3/mig-14, egl-18, and sem-4 also function during vulval development. Our characterization indicates that (1) pvl-4 and pvl-5 are required for generation/survival of the VPCs; (2) bar-1, mom-3/mig-14, egl-18, and sem-4 play a role in VPC fate specification; (3) lin-26 is required for proper VPC fate execution; and (4) pvl-6 acts during vulval morphogenesis. In addition, two of these genes, bar-1 and mom-3/mig-14, are known to function in processes regulated by Wnt signaling, suggesting that a Wnt signaling pathway is acting during vulval development.

Abrogation of the p16-Rb pathway in Korean hepatocellular carcinomas

BACKGROUND/AIMS

The tumor suppressor gene p16 on human chromosome 9p21 encodes a specific inhibitor of the cyclin D-CDK4 complex which inactivates the Rb protein by hyperphosphorylation. Many reports show that p16 is inactivated in a variety of human cancers. We investigated whether abnormalities involving p16 and Rb are associated with hepatocellular carcinomas in Korea.

METHODOLOGY

We performed loss of heterozygosity analysis on 9 primary hepatocellular carcinomas using 7 microsatellite markers spanning human chromosome 9p. Reverse transcriptase-PCR, ribonuclease protection assay, and immunoblotting were used to examine the expression of p16 and Rb in 8 hepatocellular carcinoma cell lines, including 5 from Korean patients. Exons 1 and 2 of the p16 gene were sequenced.

RESULTS

We found a 33% loss of heterozygosity at the D9S171 locus (9p21 region) in the primary hepatocellular carcinomas. The p16 protein was not found in 4 out of 5 (80%) of the Korean cell lines. Among them, 2 cell lines lacked p16 protein and had the following point mutations in p16 exon 2: Asp125 to Asn and Arg58 to Ter. Two of the Korean cell lines and the SK-Hep-1 cells contained deletions in the p16 gene. All cell lines examined, except Hep 3B, expressed Rb protein, which in all cases was dominantly hyperphosphorylated (inactivated).

CONCLUSIONS

Our results suggest that p16 and Rb abnormalities are associated with hepatocellular carcinomas in the Korean population.

Direct observation of self-focusing with subdiffraction limited resolution using near-field scanning optical microscope

The self-focusing effect in As2S3 glass has been studied using a near-field scanning optical microscope. Optical images of fine features in the self-focused beam were directly measured at the self-focus with approximately 100 nm spatial resolution. Because of the unusually large nonlinear refractive index at 690 nm, filaments with minimum size of 0.3 &mgr;m were observed in a 1.6 mW beam propagating through the 1.7 &mgr;m thin film. A qualitative analysis of our experimental results is presented. We show that nonparaxiality is responsible for arresting self-focusing, as predicted by recent theories.

Effect of immunological adjuvant combinations on the antibody and T-cell response to vaccination with MUC1-KLH and GD3-KLH conjugates

A year ago we described a comparison of 19 immunological adjuvants for their ability to augment antibody and T-cell responses against vaccines containing two cancer antigens, GD3 ganglioside and MUC1 peptide, covalently attached to keyhole limpet hemocyanin (KLH). As in our previous experience, the saponin fraction QS-21 was the most potent single adjuvant but several other adjuvants also had potent adjuvant activity. Induction of an immune response against cancer antigens is generally difficult because these antigens are autoantigens. To get maximal benefit from the adjuvant component of cancer vaccines we have now tested whether combinations of the optimal adjuvants induced an improved immune response compared to QS-21 alone. Since over the intervening year a new semi-synthetic saponin adjuvant (GPI-0100) containing the dodecylamide derivative of hydrolyzed naturally-occurring saponins had become available, this was tested as well. Twelve different adjuvant combinations and GPI-0100 were compared for their ability to augment (1) antibody responses against GD3 and MUC1 and (2) T-cell responses against GD3, MUC1 and KLH. GPI-0100 and five adjuvant combinations were superior to QS-21 alone for induction of IgM and IgG antibodies against MUC1 and/or GD3: QS-21 plus bacterial nucleotide CpG, QS-21 plus monophosphoryl lipid A (MPL), QS-21 plus non-ionic block copolymer CRL-1005, QS-21 plus Titermax and Titermax plus CpG. Antibody responses were documented both by ELISA against purified antigens and by FACS for cell surface reactivity. There was no evidence for T-cell immunity against GD3 or MUC1. The antibody responses against GD3 and MUC1 were, however, strongly correlated with IFN-gamma release and DTH against KLH. These results demonstrate that combinations of immunological adjuvants are able to augment antibody and T-cell responses to these conjugates beyond that attainable with QS-21 alone, and again confirm the absolute necessity of potent adjuvants or adjuvant combinations for optimal immunogenicity with conjugate vaccines.

Exact wave functions in a noncommutative field theory

We consider the nonrelativistic field theory with a quartic interaction on a noncommutative plane and compute the 2-->2 scattering amplitude within perturbative analysis to all orders. We regain the results of the perturbative analysis by finding the scattering and the bound state wave functions of the two particle Schrodinger equation. These wave functions unusually have two center positions in the relative coordinates, whose separation is transverse to the total momentum and scales linearly with its magnitude, exhibiting the stringy nature of the noncommutative field theory.

Brassinolide and [26, 28-2H6]brassinolide are differently demethylated by loss of C-26 and C-28, respectively, in Marchantia polymorpha

Metabolism of brassinolide in Marchantia polymorpha was investigated by use of in vivo suspension cultured cells. GC-MS analysis of metabolites derived from non-labelled brassinolide and [26, 28-2H6] brassinolide revealed that brassinolide was converted to 26-norbrassinolide while [26, 28-2H6]brassinolide to [26-2H3]28-norbrassinolide. It seems that Marchantia cells recognized [26, 28-2H6]brassinolide as a xenobiotic rather than brassinolide and deteriums attached to C-28 significantly affect demethylation reaction due to isotopic effect. Thus, demethylation of brassinolide in planta seems to proceed by loss of C-26 rather than C-28. The present finding is the first evidence for demethylation metabolism of brassinosteroids. The biological activity of 26-norbrassinolide was 10-fold reduced as shown by the rice lamina inclination test. However, because of its high biological activity, it remains difficult to conclude whether or not C-26 demethylation serves as an important deactivation process of brassinolide.

Photochemical and photobiological properties of new bispsoralen derivatives (Bis[PsCn]PIP, n = 4, 6, 8)

Bispsoralen derivatives possessing two psoralens and one piperazine molecule, 1,4-bis[n'-(8-psoralenoxy) alkyl] piperazine (Bis[PsCn]PIP, n = 4, 6, 8), show high water solubility, efficient intercalation into DNA and good photocrosslinking efficiency of DNA. Bis(PsC4)PIP shows high lethality on bacteriophage T7 and can effectively inhibit the amplification of DNA by stopping the polymerase chain reactions in a short period of irradiation time.

First Report of Occurrence of Eggplant Wilt Caused by Verticillium dahliae in Korea

A wilt disease occurred on greenhouse-grown eggplants (Solanum melongena L.) at Hanam and Yeojoo, Korea, in 1997. Lower leaves on the 2-month-old wilted eggplants exhibited gradual yellowing, interveinal necrosis, and marginal crinkling and dropped prematurely. Vascular tissues of diseased stems were discolored and turned black. Vertical sections of the stems revealed that the pith had been colonized by the fungus. The disease progressed from lower parts of the plants upward. Incidence of diseased eggplants in greenhouses was 5% on 23 May 1997. Although the incidence increased to 10% on 13 June, it remained constant through early July. Fungal isolates from discolored vascular tissues were initially whitish to cream color on potato-dextrose agar, which turned black due to the formation of microsclerotia. The fungus also produced abundant verticillate conidiophores with phialides and conidia. Based on these cultural and morphological characteristics, the fungus was identified as Verticillium dahliae Klebahn. Pathogenicity tests by root cutting, root dipping, or soil drenching resulted in similar symptoms observed in the naturally infected eggplants. Symptoms were first observed on lower leaves of each eggplant 3 weeks after inoculation. Isolation from symptomatic leaves of the inoculated eggplants yielded V. dahliae. This is the first report of occurrence of Verticillium wilt of eggplant in Korea.