Characteristics of Chinese suicide attempters admitted to a geropsychiatric unit

PURPOSE

To investigate the characteristics for elderly Chinese suicide attempters in Taiwan and make comparisons with Western reports.

METHODS

During a six-year period, patients admitted to a geropsychiatric unit as a result of a suicide attempt were investigated for factors related to the suicide attempt.

RESULTS

Of the 722 admissions during this period, 55 (7.6%) were patients who had been admitted due to suicide attempt. The sex and age distributions for the suicide attempters were similar to those for other patients. The most common diagnoses were depressive disorders (56.4%), followed by delusional disorders (20.0%). A total of 121 suicide motives were cited for the 55 attempters, an average of 2.2 per person, with depressive symptoms commonly found on admission. During the first week of hospitalization, 53 attempters (96.4%) still exhibited suicidal ideation and six patients made a further suicide attempt, however, only three patients retained suicidal ideation on discharge.

CONCLUSIONS

Our study confirms previous Western reports that depressive disorders are commonly manifested in elderly suicide attempters. There were differences in the motives and methods employed for the suicides, possibly due to cultural difference and/or sample source. Most of the suicide attempters exhibited a favourable response with hospitalization.

Identification of a 70-kDa gastrin-binding protein on DLD-1 human colorectal carcinoma cells

Gastrin17gly acts as a growth factor for the colonic mucosa. Studies of the receptor involved have generally been restricted to its binding properties, and no investigation of the structure of gastrin17gly receptors on human colorectal carcinoma cell lines has yet been reported. The aim of this study was to optimise the conditions for binding of gastrin17gly to the human colorectal carcinoma cell line DLD-1, and to investigate the structure of the receptor responsible. Binding of 125I[Met15]gastrin17gly to DLD-1 cells was measured in competition experiments with increasing concentrations of either gastrin17gly or gastrin17, or with single concentrations of gastrin receptor antagonists. The molecular weights of the gastrin17gly binding proteins were determined by gel electrophoresis and autoradiography after covalent cross-linking of 125I[Nle15]gastrin2,17gly to cells or membranes with disuccinimidyl suberate. The IC50 value for binding of gastrin17gly to DLD-1 cells was 2.1+/-0.4 microM. Binding was inhibited by the non-selective gastrin/cholecystokinin receptor antagonists proglumide and benzotript, but not by the cholecystokinin-A receptor antagonist L364,718, or the gastrin/cholecystokinin-B receptor antagonist L365,260. The molecular weight of the major gastrin binding protein on DLD-1 cells or membranes was 70,000. We conclude that the major gastrin17gly binding site on the human colorectal carcinoma cell line DLD-1 is clearly distinct from the cholecystokinin-A and gastrin/cholecystokinin-B receptors, but is similar in some respects to the gastrin/cholecystokinin-C receptor.

Gemcitabine-induced acute lipodermatosclerosis-like reaction

Gemcitabine is considered to be a well-tolerated and safe cytostatic drug because of the relative lack of side effects. Cutaneous reactions due to gemcitabine treatment, including alopecia and maculopapular eruption, are well known. We report one patient with squamous cell carcinoma of the lung who developed a gemcitabine-induced cutaneous reaction mimicking acute lipodermatosclerosis. This case has never been reported in the literature before.

Assembly of the human signal recognition particle (SRP): overlap of regions required for binding of protein SRP54 and assembly control

Assembly of the human signal recognition particle (SRP) entails the incorporation of protein SRP54, mediated by a protein SRP1 9-induced conformational change in SRP RNA. To localize the region that controls this crucial step in the assembly of human SRP RNA, four chimeras, Ch-1 to Ch-4, composed of portions of human and Methanococcus jannashii SRP RNAs, were generated by PCR site-directed mutagenesis from a larger precursor. Protein-binding activities of the hybrid RNAs were determined using purified human SRP19 and a polypeptide (SRP54M) that corresponded to the methionine-rich domain of human SRP54. Mutant Ch-1 containing the large domain of M. jannashii SRP RNA, as well as mutant Ch-2 RNA in which helices 6 and 8 were replaced, bound SRP54M independently of SRP19. Mutant Ch-3 RNA, which contained M. jannashii helix 6, required SRP19 for binding of SRP54M, but mutant Ch-4 RNA, which possessed M. jannashii helix 8, bound SRP54M without SRP19. We concluded that the formation of a stable ternary complex did not rely on extensive conformational changes that might take place throughout the large domain of SRP, but was controlled by a smaller region encompassing certain RNA residues at positions 177 to 221. Five chimeric RNAs altered within helix 8 were used to investigate the potential role of a significant AA-to-U change and to determine the boundaries of the assembly control region. Reduced protein-binding activities of these chimeras demonstrated a considerable overlap of regions required for SRP54 binding and assembly control.

A MADS box gene from lily (Lilium Longiflorum) is sufficient to generate dominant negative mutation by interacting with PISTILLATA (PI) in Arabidopsis thaliana

Lily MADS box gene 1 (LMADS1), with sequence homology to the AP3 family of genes, was cloned and characterized from lily (Lilium longiflorum). LMADS1 protein contains almost complete consensus sequence of the PISTILLATA (PI)-derived motif (YEFRVQPSQPNLH) found in the AP3 family of genes and paleoAP3 motif (YGSHDLRLA) found in the AP3 family of genes from the low eudicot, magnolid dicot and monocot species. LMADS1 mRNA was expressed in all four whorls of the flower and absent in the vegetative leaves. The LMADS1 protein was only detected in the petals and stamens, indicating that LMADS1 is possibly post-transcriptionally regulated in lily. Arabidopsis plants transformed with 35S::LMADS1 produced flowers with short petals and stamens, however, no floral organ conversion was observed. Ectopic expression of LMADS1 cDNA truncated with the MADS box domain in Arabidopsis generated the ap3-like dominant negative mutation in which the petals were converted into sepal-like structures and the stamens were converted into carpel-like structures. Yeast two-hybrid analysis indicated that LMADS1 truncated with the MADS box domain is able to sufficiently interact with the Arabidopsis PI protein. This result supports that LMADS1 is the functional counterpart of the AP3 gene in lily. Interestingly, in contrast to other B functional genes, LMADS1 truncated with the MADS box domain is able to strongly form homodimers. LMADS1 may represent an ancestral form of the B function gene, which retains the ability to form homodimers in regulating petal and stamen development in lily.

Reversible infra-Hisian atrioventricular block in acute myocarditis

Symptomatic second- or third-degree atrioventricular (AV) block at any anatomical level is a class I indication for permanent pacemaker implantation. We describe a 44-year-old male with acute viral myocarditis who suffered from syncope followed by a seizure attack associated with AV conduction disturbance. His initial electrocardiogram in our emergency room revealed sinus tachycardia with 2:1 AV conduction and a right bundle branch block QRS morphology with a ventricular rate of 60 beats/min. Because of episodic slowing of the heart rate below 40 beats/min, he received 1 mg atropine intravenously which increased the atrial rate but further worsened the AV conduction, resulting in ventricular asystole for more than 30 seconds associated with loss of consciousness and seizure-like activity. He was immediately paced transcutaneously and transferred to the catheterization laboratory to receive temporary transvenous cardiac pacing. The cardiac catheterization study showed a normal coronary angiogram and very mild diffuse hypokinesis. Electrophysiological studies revealed advanced infra-Hisian AV block. The infra-Hisian AV block, however, resolved rapidly in 2 days. The patient did not receive a permanent pacemaker and remained asymptomatic with normal electrocardiogram over 1 year of follow-up. We suggest that symptomatic infra-Hisian AV block due to viral myocarditis can be reversible, and implantation of a permanent pacemaker may not be necessary.

Microcosm enrichment of 1,3-dichloropropene-degrading soil microbial communities in a compost-amended soil

AIMS

A microcosm-enrichment approach was used to investigate bacterial populations that may represent 1,3-dichloropropene (1,3-D)-degrading micro-organisms in compost-amended soil.

METHODS AND RESULTS

After 8 weeks of incubation, with repeated application of 1,3-D, volatilization fluxes were much lower for compost-amended soil (CM) than with the unamended soils, indicating accelerated degradation due to addition of compost, or development of new microbial populations with enhanced degradation capacity. Denaturing gradient gel electrophoresis (DGGE) profiles of the PCR-amplified region of 16S rDNA genes were used to identify dominant bacterial populations in the fumigant-degrading soil. The DGGE results indicated that specific bacterial types had been enriched, and a more diverse fingerprint was observed in the community derived from the compost-amended soil compared with the unamended soil. Fragments from 16 different DGGE bands were cloned, sequenced and compared with published 16S rDNA sequences. Two clones, designated E1 and E4, were unique to all soils to which compost was added, and corresponded to strains of Pseudomonas and Actinomadura, respectively.

CONCLUSIONS

The results show that the addition of compost to soil increases specific microbial populations and results in the accelerated degradation of fumigants.

SIGNIFICANCE AND IMPACT OF THE STUDY

Application of compost manure to soil can help degrade soil fumigants at a faster rate.

Extraction of human DNA for PCR from chewed residues of betel quid using a novel "PVP/CTAB" method

Residues of chewed betel quid (BQ) are often found on crime scenes in Taiwan and possibly some of the Southeast Asian countries. Although these residues are important biological evidences relating to the suspects, the forensic analysis of BQ evidence has been hindered by failures in extraction of human DNA for PCR analysis. Therefore, it is a prerequisite for relevant forensic casework to establish a reliable method for extracting DNA from chewed BQ residues. Three conventional methods (salt/chloroform, 5% Chelex-100 resin, and QIAamp) were first tested for extraction of human DNA from 33 mock BQ samples, which had been stored for less than two months, and 50 four-year-old forensic BQ samples. PCR amplifications from the HLA-DQA1&PM and the STR loci were then used to test the quality of the extracted DNA. For the mock samples, three observations were made. First, PCR amplification of DNA extracted by using these conventional methods had low success rate. Second, the addition of extra Taq DNA polymerase could compensate the lost enzyme activities due to putative inhibitors and, thus, increase the yield. Third, using the Centricon-100 column to remove putative inhibitors substantially improved the efficiency of PCR. However, for the four-year-old forensic BQ samples, none of the attempts for PCR were successful. In order to solve the problem in PCR analysis of DNA from old BQ samples, we developed a DNA extraction method based on the use of polyvinyl pyrrolidone (PVP) and cetyltrimethylammonium bromide (CTAB), which bind to two common classes of PCR inhibitors in plants, polyphenols, and polysaccharides, respectively. The result showed that this "PVP/CTAB" method is completely successful for the mock BQ samples, and 92% (46 out of 50) successful for the four-year-old forensic BQ samples. To our best knowledge, this is the first report of a reliable method for the extraction of human DNA for PCR from chewed BQ residues. This method should provide a useful means for forensic identification in countries where betel chewing is common.

p16(INK4a) Promoter hypermethylation of non-tumorous tissue adjacent to gastric cancer is correlated with glandular atrophy and chronic inflammation

The p16(INK4a) tumor suppressor gene can be inactivated by promoter region hypermethylation in many tumor types including gastric cancers. However, p16(INK4a) promoter hypermethylation in the surrounding non-tumorous tissues of gastric cancers has not been studied in detail. We therefore examined 46 gastric cancers, corresponding adjacent non-tumorous tissue samples and 8 gastric tissue samples of chronic gastritis by performing methylation-specific polymerase chain reaction, and we analyzed p16(INK4a) protein expression using immunohistochemistry and Western blot. p16(INK4a) promoter hypermethylation was observed in 43% of gastric cancers and 59% of adjacent non-tumorous tissues; however, none of the samples retrieved from the chronic gastritis patients displayed p16(INK4a) promoter hypermethylation. Gastric cancers showed an inverse correlation between vascular invasion and p16(INK4a) promoter hypermethylation, and adjacent non-tumorous tissues displayed a close association among the grade of chronic inflammation, presence of glandular atrophy and p16(INK4a) promoter hypermethylation. p16(INK4a) expression was markedly decreased in samples with p16(INK4a) promoter hypermethylation when compared with samples without p16(INK4a) promoter hypermethylation. These results suggest that p16(INK4a) promoter hypermethylation is an early and frequent event in gastric carcinogenesis and may serve as a new prognostic biomarker for the risk of gastric cancers.

The application of the neural network on Morse code recognition for users with physical impairments

Morse code is a simple, speedy and low cost means of communication composed of a series of dots, dashes and space intervals. Each tone element (either a dot, dash or space interval) is transmitted by sending a signal for a defined length of time. This poses a challenge as the automatic recognition of Morse code is dependent upon maintaining a stable typing rate. In this paper, a suitable adaptive automatic recognition method, combining the least-mean-square (LMS) algorithm with a neural network, was applied to this problem. The method presented in this paper is divided into five modules: space recognition, tone recognition, learning process, adaptive processing and character recognition. Statistical analyses demonstrated that the proposed method elicited a better recognition rate in comparison with other methods in the literature.

EMF1, a novel protein involved in the control of shoot architecture and flowering in Arabidopsis

Shoot architecture and flowering time in angiosperms depend on the balanced expression of a large number of flowering time and flower meristem identity genes. Loss-of-function mutations in the Arabidopsis EMBRYONIC FLOWER (EMF) genes cause Arabidopsis to eliminate rosette shoot growth and transform the apical meristem from indeterminate to determinate growth by producing a single terminal flower on all nodes. We have identified the EMF1 gene by positional cloning. The deduced polypeptide has no homology with any protein of known function except a putative protein in the rice genome with which EMF1 shares common motifs that include nuclear localization signals, P-loop, and LXXLL elements. Alteration of EMF1 expression in transgenic plants caused progressive changes in flowering time, shoot determinacy, and inflorescence architecture. EMF1 and its related sequence may belong to a new class of proteins that function as transcriptional regulators of phase transition during shoot development.

EMF1, a novel protein involved in the control of shoot architecture and flowering in Arabidopsis

Shoot architecture and flowering time in angiosperms depend on the balanced expression of a large number of flowering time and flower meristem identity genes. Loss-of-function mutations in the Arabidopsis EMBRYONIC FLOWER (EMF) genes cause Arabidopsis to eliminate rosette shoot growth and transform the apical meristem from indeterminate to determinate growth by producing a single terminal flower on all nodes. We have identified the EMF1 gene by positional cloning. The deduced polypeptide has no homology with any protein of known function except a putative protein in the rice genome with which EMF1 shares common motifs that include nuclear localization signals, P-loop, and LXXLL elements. Alteration of EMF1 expression in transgenic plants caused progressive changes in flowering time, shoot determinacy, and inflorescence architecture. EMF1 and its related sequence may belong to a new class of proteins that function as transcriptional regulators of phase transition during shoot development.

Characterization of stress-responsive genes, hrcA-grpE-dnaK-dnaJ, from phytopathogenic Xanthomonas campestris

Sequencing of a 6.4-kb DNA fragment, cloned from the plant pathogenic bacterium Xanthomonas campestris pv. campestris 17 revealed five ORFs whose deduced amino acid sequences show strong similarities to the bacterial HrcA, GrpE, DnaK, DnaJ, and PdxK. The four heat shock genes are organized in the order hrcA-grpE-dnaK-dnaJ, a genome organization found in many gram-positive bacteria, but only in one gram-negative species (Xylella fastidiosa). These observations suggest that the HrcA-CIRCE system, comprising at least four genes arranged in this order, already existed for the regulation of stress responses before bacteria diverged into gram-negative and gram-positive groups. Primer-extension results suggested the presence of promoters at the regions upstream of grpE and dnaK. In the presence of stress, heat or ethanol (4%), the X. campestris pv. campestris 17 grpE and dnaK promoters were induced two- to three-fold over controls. Since the grpE and dnaK promoters possess E. coli sigma(32) promoter-like sequences, they are functional in E. coli, although at levels much lower than in X. campestris pv. campestris 17. Furthermore, expression of the X. campestris pv. campestris 17 dnaK promoter in E. coli was elevated by the cloned X. campestris sigma(32) gene, indicating that the cognate sigma(32) works more efficiently for the X. campestris promoters.

Impact of fumigants on soil microbial communities

Agricultural soils are typically fumigated to provide effective control of nematodes, soilborne pathogens, and weeds in preparation for planting of high-value cash crops. The ability of soil microbial communities to recover after treatment with fumigants was examined using culture-dependent (Biolog) and culture-independent (phospholipid fatty acid [PLFA] analysis and denaturing gradient gel electrophoresis [DGGE] of 16S ribosomal DNA [rDNA] fragments amplified directly from soil DNA) approaches. Changes in soil microbial community structure were examined in a microcosm experiment following the application of methyl bromide (MeBr), methyl isothiocyanate, 1,3-dichloropropene (1,3-D), and chloropicrin. Variations among Biolog fingerprints showed that the effect of MeBr on heterotrophic microbial activities was most severe in the first week and that thereafter the effects of MeBr and the other fumigants were expressed at much lower levels. The results of PLFA analysis demonstrated a community shift in all treatments to a community dominated by gram-positive bacterial biomass. Different 16S rDNA profiles from fumigated soils were quantified by analyzing the DGGE band patterns. The Shannon-Weaver index of diversity, H, was calculated for each fumigated soil sample. High diversity indices were maintained between the control soil and the fumigant-treated soils, except for MeBr (H decreased from 1.14 to 0.13). After 12 weeks of incubation, H increased to 0.73 in the MeBr-treated samples. Sequence analysis of clones generated from unique bands showed the presence of taxonomically unique clones that had emerged from the MeBr-treated samples and were dominated by clones closely related to Bacillus spp. and Heliothrix oregonensis. Variations in the data were much higher in the Biolog assay than in the PLFA and DGGE assays, suggesting a high sensitivity of PLFA analysis and DGGE in monitoring the effects of fumigants on soil community composition and structure. Our results indicate that MeBr has the greatest impact on soil microbial communities and that 1,3-D has the least impact.

Weekly and monthly regimens of paclitaxel and carboplatin in the management of advanced ovarian cancer. A preliminary report on side effects

This preliminary study was carried out over 18 months to evaluate whether the side effects in patients with advanced ovarian cancer receiving chemotherapy using paclitaxel-carboplatin differed between weekly (98 cycles in 14 patients) and monthly (102 cycles in 15 patients) administrations. We used paclitaxel (60 mg/m2) and carboplatin (AUC of 2) in the weekly regimen and 175 mg/m2 of paclitaxel and carboplatin (AUC of 6) in the monthly regimen. All eligible patients received at least four cycles of treatment in both regimens. The results revealed significantly decreased hematological toxicity in weekly regimens relative to monthly ones, ie, 7.1% vs. 18.6% of anemia (> or = grade 2), 7.1% vs. 32.3% of grade 3/4 granulocytopenia, and 0% vs. 15.7% of >grade 2 thrombocytopenia. There was no significant difference in nonhematological toxicities between the two regimens. The incidence of unscheduled events was much less in the weekly regimen than in the monthly one; ie, delayed treatment (3 vs. 18 events), unanticipated hospitalizations (3 vs. 15 times), and supplemental support with G-CSF (7 vs. 33 times). Complete responses were observed in 6 of 14 patients in the weekly regimen and in five of 15 patients in the monthly regimen, while partial responses were seen in four and five patients in the weekly and monthly regimens, respectively. The present results demonstrate that the weekly regimen can achieve the benefits of tolerable toxicity with significantly reduced myelosuppression and improved cost-effectiveness in terms of unscheduled events.

Analysis of Fc gammaRIII and IgG Fc polymorphism reveals functional and evolutionary implications of protein-protein interaction

Fc gamma receptor III (Fc gammaRIII), a low-affinity receptor for the Fc portion of immunoglobulin G (IgG Fc), targets antigen-antibody complexes in a variety of effector cells of the immune system. We have investigated Fc gammaRIII and IgG Fc polymorphism and made comparative analysis of the functional and evolutionary implications of the interaction between these two molecules. Sequence analysis and comparison of the three-dimensional structure suggest that the C-terminal Ig domain of Fc gammaRIII is associated with the binding of IgG. The polymorphic residues of Fc gammaRIII are mainly located in the region of the C-terminal Ig domain that might be involved in IgG binding. Therefore, polymorphism and functional binding affinity seems to be related to each other as has been increasingly implicated in clinical observations. IgG Fcs, the natural ligand of Fc gammaRs, also exhibit significant polymorphism. Three regions have been identified where polymorphism frequently occurs: the putative FcR binding site, the linker region, and the intermolecular domain-domain interface of the second Ig domain. The putative Fc gammaR binding sites where polymorphic, and isotype-specific residues cluster are consistent with the regions that have been identified by mutagenesis and molecular modeling studies. The polymorphic residues of IgG Fc were mainly located in the molecular surface, which could be used in the recognition of other binding molecules. These observations suggest that polymorphic and isotype-specific residues in IgG Fc are closely related to their function and protein-protein interaction. Therefore, the colocalization of the polymorphic residues of Fc gammaRIII and IgG Fcs at their docking sites implies that the polymorphic residues would affect the IgG-Fc gammaRIII binding interactions to optimize their signaling through evolution.

Somatic and Germline Mutation of Forensic DNA Markers

Somatic and germline mutations of forensic DNA markers DQA1, PM, STR, minisatellite DNA, and mtDNA are reviewed in this paper. DQA1 and PM are stable point substitution polymorphic loci in nuclear DNA (nucDNA); thus, somatic and germline mutations are rarely reported. STR loci somatic mutations are not found in normal cells but are very unstable in cancer cells. Germline mutations are detected in STR loci with a mutation rate of approximately 0.1%. Germline mutations of STR loci are nucleotide sequence, sex, and age dependent. Among the 13 CODIS core, TH01, TPOX, D16S539, and D3S1358 are more stable than others. Both somatic and germline mutations are found in minisatellite loci. Somatic mutations at mtDNA central region (CR) are detected in different tissues within the same individual, and the mutation rates are high in several cancer tissues. The intergenerational mutation rate of mtDNA CR is estimated to be 1/400 to 1/1200 per generation by phylogenetic analysis. The intergenerational mutation rate estimated by the recently developed pedigree method is higher, 14/1221 (1/87). This rate does not include the hot spot and heteroplasmic mutation. If substitution, heteroplasmic, and poly-C tract mutation are included, the mutation rate of mtDNA CR is 33/1590 (1/49) per generation. Proposals and practices on the interpretation of test data that may be associated with mutation are also discussed.

Synthesis and DNA nicking studies of a novel cyclic peptide: cyclo[Lys-Trp-Lys-Ahx-]

Two novel cyclic tetrapeptides: cyclo[Lys-Tyr-Lys-Ahx-] 7a and cyclo[Lys-Trp-Lys-Ahx-] 7b were synthesized by coupling protected amino acid in solution and the subsequent cyclization effected by the pentafluorophenyl ester method as described in previous papers. These cyclic peptides were designed and synthesized to study their interaction with DNA, based on previous reports that linear peptides Lys-Tyr-Lys and Lys-Trp-Lys could bind to various forms of DNA and cleaved supercoiled DNA at apurinic sites. Ethidium bromide displacement assay showed that the apparent DNA binding constant of linear Lys-Tyr-Lys and cyclic peptide 7a are far below 1 x 10(3) M(-1), whereas those of cyclic peptide 7b and linear Lys-Trp-Lys are 1.9 x 10(4) M(-1) and 9.5 x 10(3) M(-1), respectively. Kinetic studies using agarose gel electrophoresis showed that cyclic peptide 7b and Lys-Trp-Lys possessed DNA nicking activity on natural supercoiled phi X174 DNA with nicking rate of 50.7 and 75.6 pM min(-1) at 65 degrees C, respectively, whereas cyclic peptide 7a and linear Lys-Tyr-Lys were devoid of the corresponding activity. The DNA nicking rate increased significantly with increase in reaction temperature. At reaction temperatures lower than 65 degrees C, the DNA nicking rate of cyclic peptide 7b exceeded that of linear Lys-Trp-Lys. The addition of 1 microM ferrous ion did not give significant enhancement effect on the DNA nicking rate by the peptides. UV irradiation gave a marked rate enhancement on the DNA nicking rate of linear Lys-Trp-Lys and a moderate enhancement on the DNA nicking rate of cyclic peptide 7b.

Endometrium estimation in a sequence of ultrasonic images

In this paper a novel algorithm for motion estimation of the endometrium in a sequence of ultrasonic images is presented. The algorithm used is based on the criterion that a pixel of a motion object at different times has a different gray value. The motion estimation includes motion frequency and thickness; the former one is determined by the detection of change of a pixel value in a sequence of images during a given time period, and the latter is the result of the object's dimension divided by its extended width. The algorithm has been tested on synthetic and real images, and the results are encouraging.

EMF genes interact with late-flowering genes in regulating floral initiation genes during shoot development in Arabidopsis thaliana

To investigate the mechanisms regulating the initiation of floral development in Arabidopsis, a construct containing beta-glucuronidase (GUS) gene driven by APETALA1 promoter (AP1::GUS) was introduced into emf fwa and emf ft double mutants. GUS activity was strongly detected on shoot meristem of emf1-1 single mutants harboring AP1::GUS construct just 5 d after germination. By contrast, GUS activity was undetectable on emf1-1 fwa-1, emf1-1 ft-1, emf2-1 fwa-1, emf2-3 fwa-1 and emf2-3 ft-1 double mutants harboring AP1::GUS construct 10 d after germination. GUS activity was only weakly detected on the apical meristem of 20-day-old emf1-1 fwa-1 and emf2-1 fwa-1 seedlings. During this time, only sessile leaves were produced. Further analysis indicated that AP1 was strongly expressed in 10-day-old emf1-1 and emf2-1 single mutants. Its expression was significantly reduced in all emf1-1 or emf2-1 late-flowering double mutants tested. Similar to AP1, the expression of LEAFY (LFY) was also high in emf1-1 and emf2-1 single mutants and reduced in emf1-1 or emf2-1 late-flowering double mutants. Our results indicate that the precocious expression of AP1 and LFY is dependent not only on the low EMF and FWA activities but also on the expression of most of the late-flowering genes such as FT, FCA, FE, CO and GI. These data also reveal that most late-flowering genes may function downstream of EMF or in pathways distinct from EMF to activate genes specified floral meristem identity during shoot maturation in Arabidopsis.

Interferon alpha /beta promotes cell survival by activating nuclear factor kappa B through phosphatidylinositol 3-kinase and Akt

Interferons (IFNs) play critical roles in host defense by modulating gene expression via activation of signal transducer and activator of transcription (STAT) factors. IFN-alpha/beta also activates another transcription factor, nuclear factor kappaB (NF-kappaB), which protects cells against apoptotic stimuli. NF-kappaB activation requires the IFN-dependent association of STAT3 with the IFNAR1 chain of the IFN receptor. IFN-dependent NF-kappaB activation involves the sequential activation of a serine kinase cascade involving phosphatidylinositol 3-kinase (PI-3K) and Akt. Whereas constitutively active PI-3K and Akt induce NF-kappaB activation, Ly294002 (a PI-3K inhibitor), dominant-negative PI-3K, and kinase-dead Akt block IFN-dependent NF-kappaB activation. Moreover, dominant-negative PI-3K blocks IFN-promoted degradation of kappaBox alpha. Ly294002, a dominant-negative PI-3K construct, and kinase-dead Akt block IFN-promoted cell survival, enhancing apoptotic cell death. Therefore, STAT3, PI-3K, and Akt are components of an IFN signaling pathway that promotes cell survival through NF-kappaB activation.

Pharmacokinetics of the ganciclovir implant in the silicone-filled eye

PURPOSE

Ganciclovir (GCV) implants are highly effective in delaying the progression of cytomegalovirus (CMV) retinitis. Rhegmatogenous retinal detachments can occur in untreated eyes with CMV retinitis or in eyes treated with anti-CMV therapy, which may include placement of a GCV implant. The clinical management of CMV retinitis and associated retinal detachment often involves the concurrent use of silicone oil and GCV implants. The authors investigated the effect of silicone oil tamponade on intravitreal drug levels achieved with the GCV implant.

METHODS

The authors performed gas compression vitrectomy in the right eyes of 29 New Zealand white rabbits. They then inserted a 5-mg GCV implant into the vitreous cavity through an inferotemporal sclerotomy. Saline (1 cc), silicone oil 0.5 cc, or silicone oil 1.0 cc was then injected into the midvitreous cavity of 9, 8, and 12 rabbits, respectively. On postoperative days 21, 42, and 70, the rabbits were killed and the right eyes were immediately collected and stored at -70 degrees C until all samples were obtained. Vitreous was then isolated and drug levels were determined by high-pressure liquid chromatography.

RESULTS

Vitreous GCV levels at days 21 and 42 were similar in both the saline-filled and silicone oil-filled eyes. At day 70, GCV levels in both the saline- and silicone-filled eyes were statistically significantly lower than at day 21 (P < 0.05 for all groups). In addition, at day 70, GCV levels in the saline-filled eyes were significantly lower than in silicone-filled eyes (saline versus 0.5 cc oil, P = 0.01; saline versus 1 cc oil, P = 0.09).

CONCLUSIONS

Effective GCV levels are maintained in the aqueous phase of the vitreous cavity of eyes with silicone oil tamponade. Ganciclovir levels may be maintained longer in eyes with silicone oil tamponade than in those without. These results support the use of combined GCV implants and silicone oil tamponade in patients with CMV retinitis and associated retinal detachment.