The expression of pseudogene cyclin D2 mRNA in the human ovary may be a novel marker for decreased ovarian function associated with the aging process

PURPOSE

Our purpose was to investigate the expression pattern of cyclin D2 and pseudogene cyclin D2 mRNA in the human ovary with age.

METHODS

After extraction of the total RNA from ovarian tissues of 23 premenopausal patients, cyclin D2 and pseudogene cyclin D2 mRNAs were measured by the reverse transcription-polymerase chain reaction technique using cyclin D2 and pseudogene cyclin D2 specific primers. Analysis of the cyclin D2 and pseudogene cyclin D2 mRNA expression pattern with age and correlation analysis were carried out.

RESULTS

A 489-bp cyclin D2 band and a 441-bp pseudogene cycin D2 mRNA band were detected in the human ovarian tissue. While cyclin D2 mRNA expression showed a decreasing tendency with age (P = 0.17), pseudogene cyclin D2 mRNA expression increased with age (P < 0.05). Pseudogene cyclin D2 mRNA expression showed a negative correlation with cyclin D2 mRNA (R = -0.35, P < 0.03).

CONCLUSION

The expression of pseudogene cyclin D2 mRNA in the human ovary increases with age, which may be a novel marker for decreased ovarian function associated with the aging process.

CREB-binding protein and histone deacetylase regulate the transcriptional activity of Kaposi's sarcoma-associated herpesvirus open reading frame 50

Kaposi's sarcoma (KS)-associated herpesvirus (KSHV) open reading frame 50 (ORF50) encodes a viral transcriptional activator, which binds to the KSHV promoter and stimulates the transcription of viral early and late genes, thus activating the lytic cycle of KSHV. We report here that KSHV ORF50 binds to the cellular proteins CREB-binding protein (CBP) and histone deacetylase (HDAC) and these binding events modulate ORF50-activated viral transcription. Binding of ORF50 to CBP and HDAC activates and represses, respectively, ORF50-mediated viral transcription. KSHV ORF50 was shown to bind to the C/H3 domain and the C-terminal transcriptional activation domain of CBP, while CBP bound to the amino-terminal basic domain and the carboxyl-terminal transactivation domain of ORF50. The LXXLL motif within the transcriptional activation domain of ORF50 is reminiscent of the CBP-binding sequence found in nuclear receptor proteins. The adenovirus E1A protein, which also binds to the C/H3 domain of CBP, repressed the transcriptional activation activity of ORF50. The cellular protein c-Jun, which binds to the kinase-induced activation domain of ORF50, stimulated ORF50-mediated viral transcription. The HDAC1-interacting domain of ORF50 was shown to be a central proline-rich sequence. Our data provide a framework for delineating the regulatory mechanisms used by KSHV to modulate its transcription and replication through interaction with both histone acetyltransferases and HDACs.

Requirement for cytoplasmic protein synthesis during circadian peaks of transcription of chloroplast-encoded genes in Chlamydomonas

Cycloheximide, an inhibitor of cytoplasmic translation, induced a rapid reduction of 70-80% in levels of mRNA for the chloroplast elongation factor Tu (tufA) in asynchronously growing Chlamydomonas. This effect was shown to be mainly transcriptional, and not restricted to tufA, as transcription of other chloroplast-encoded genes were cycloheximide-sensitive, although not all equally (psbA showed no more than 40% inhibition). Confirmatory evidence that the inhibition of chloroplast transcription was mainly due to blocking cytoplasmic translation was obtained with the cycloheximide-resistant mutant act1, and by using another translation inhibitor, anisomycin. In synchronously growing Chlamydomonas, chloroplast transcription is regulated by the circadian clock, with the daily peak occurring during the early light period. When cycloheximide was added during this period, transcription was inhibited, but not when it was added during the trough period (late light to early dark). Moreover, in synchronized cells switched to continuous light, the drug blocked the scheduled increase in tufA mRNA, but did not remove the pre-existing mRNA. These experiments define two functionally different types of chloroplast transcription in Chlamydomonas, basal (cycloheximide-insensitive) and clock-induced (cycloheximide-sensitive), and indicate that the relative contribution of each type to the overall transcription of a given gene are not identical for all genes. The results also provide evidence for nuclear regulation of chloroplast transcription, thereby obviating the need for an organellar clock, at least for these rhythms.

The K-bZIP protein from Kaposi's sarcoma-associated herpesvirus interacts with p53 and represses its transcriptional activity

Kaposi's sarcoma-associated herpesvirus (KSHV) is a gammaherpesvirus that has been implicated in the pathogenesis of Kaposi's sarcoma. KSHV encodes K-bZIP (open reading frame K8), a protein that belongs to the basic region-leucine zipper (bZIP) family of transcription factors. Here we show that K-bZIP associates with the cellular transcription factor p53 directly in vitro and in vivo. This interaction requires the bZIP domain of K-bZIP and the carboxy-terminal region (amino acids 300 to 393) of p53. We also show that K-bZIP represses the transcriptional activity of p53 which is required for apoptosis of the host cell. These results imply that K-bZIP blocks p53-mediated host cell death through its interaction with p53.

Efficacy and response time to sertraline versus fluoxetine in the treatment of unipolar major depressive disorder

BACKGROUND

Few studies have compared the treatment efficacy of the 2 selective serotonin reuptake inhibitors sertraline and fluoxetine.

METHOD

A randomized, single-blind, parallel-group study of 10 weeks' duration comparing the efficacy of sertraline, 50 mg/day; sertraline, 100 mg/day; and fluoxetine, 20 mg/day, was conducted in 44 psychiatric outpatients with DSM-IV unipolar major depressive disorder. Antidepressant dosages were doubled at 6 weeks for subjects who had not achieved remission. Primary outcome measurements included the 21-item Hamilton Rating Scale for Depression (HAM-D) and the Clinical Global Impressions-Improvement scale (CGI-I), with scores of < or = 7 on the HAM-D and < or = 2 on the CGI-I representing a positive treatment response, i.e., remission.

RESULTS

At 4 weeks, significant differences in rate of positive treatment response were noted, with 0% for sertraline, 50 mg; 46% for sertraline, 100 mg; and 31% for fluoxetine, 20 mg (p = .023). At 6 weeks, positive treatment response rates were 21%, 43%, and 31% for subjects taking 50 mg of sertraline, those taking 100 mg of sertraline, and those taking 20 mg of fluoxetine, respectively, with treatment groups no longer differing significantly from each other. In subjects for whom antidepressant dose was doubled at week 6, response rates at week 10 (4 weeks on increased dose) were 40% for sertraline, 100 mg; 43% for sertraline, 200 mg; and 55% for fluoxetine, 40 mg.

CONCLUSION

Subjects taking sertraline, 100 mg, and fluoxetine, 20 mg, demonstrated an earlier treatment response compared with subjects taking sertraline, 50 mg. For patients without a positive response at 6 weeks, an increased antidepressant dose resulted in remission for a substantial proportion of patients when assessed 4 weeks later.

HIV-1 TAR RNA enhances the interaction between Tat and cyclin T1

Human immunodeficiency virus, type 1 (HIV-1), Tat activates elongation of RNA polymerase II transcription at the HIV-1 promoter through interaction with the cyclin T1 (CycT1) subunit of the positive transcription elongation factor complex, P-TEFb. Binding of Tat to CycT1 induces cooperative binding of the P-TEFb complex onto nascent HIV-1 TAR RNA. Here the specific interaction between Tat protein, human cyclin T1, and HIV-1 TAR RNA was analyzed by fluorescence resonance energy transfer, using fluorescein-labeled TAR RNA and a rhodamine-labeled Tat protein synthesized through solid-phase chemistry. We find that CycT1 remodels the structure of Tat to enhance its affinity for TAR RNA and that TAR RNA further enhances the interaction between Tat and CycT1. We conclude that TAR RNA nucleates the formation of the Tat.P-TEFb complex through an induced fit mechanism.

Clinical correlation of cyclin D2 mRNA expression in human luteinized granulosa cells

PURPOSE

The aim was to evaluate whether the expression of cyclin D2 mRNA in human luteinized granulosa cells correlates with the clinical parameters of women undergoing in vitro fertilization-embryo transfer (IVF-ET) programs.

METHODS

Using reverse transcriptase-polymerase chain reaction (RT-PCR) techniques, the cyclin D2 mRNA in human luteinized granulosa cells of large follicles was measured. Correlation analysis between cyclin D2 mRNA expression and clinical parameters [age; day 3 follicle-stimulating hormone (FSH), luteinizing hormone (LH), and estradiol (E2); E2 and P4 at the day of human chorionic gonadotropin (hCG); total amount of gonadotropin and the number of days of gonadotropin administration; pregnancy outcome] were performed.

RESULT(S)

Cyclin D2 mRNA expression showed negative correlation with patient's age (R = -0.60, P < 0.005) and total amount of gonadotropins (R = -0.45, P < 0.03), and also showed positive correlation with serum E2 levels at the day of hCG administration (R = 0.55, P < 0.02). Other clinical parameters showed no statistical significance. Cyclin D2 mRNA expression of pregnant group was higher than that of nonpregnant group (P < 0.03).

CONCLUSIONS

Cyclin D2 mRNA expression in human luteinized granulosa cells positively correlates with clinical parameters of ovarian function and may be a novel marker for the health of human ovarian follicle.

Concurrent validity of negative symptom assessments in treatment refractory schizophrenia: relationship between interview-based ratings and inpatient ward observations

The concurrent validity of interview-based ratings of negative symptoms in 35 inpatients with chronic, treatment refractory schizophrenia was evaluated. Correlations were examined between interview-based ratings of negative symptoms, measured by the Brief Psychiatric Rating Scale and the Positive and Negative Syndrome Scale, and the naturalistic behavior of inpatients as assessed by the Time Sample Behavior Checklist. Higher levels of interview-based negative symptoms were related to reduced interpersonal activity on the inpatient ward, but not to entertainment, instrumental or self-maintenance activities. These findings offer partial support for the concurrent validity of office-based ratings of negative symptoms, and highlight the importance of longitudinal observations of patients for accurate identification of negative symptoms.

One hundred and eleven liver resections for hilar bile duct cancer

A positive correlation between absence of residual tumor at resection margins and long-term survival in the treatment of hilar bile duct carcinoma has encouraged some surgeons to use a more radical approach, including liver/portal vein resection and combined pancreatoduodenectomy. However, if liver resection is associated with significant morbidity and mortality, it may not produce any overall benefit. This review was undertaken in an attempt to determine whether liver resection is a safe procedure and whether if has any beneficial effect over that of local bile duct excision alone, in terms of achieving curative resection and long-term survival. The records of 151 patients with hilar bile duct carcinoma surgically treated between June 1989 and December 1997 at the Asan Medical Center, Seoul, were retrospectively analyzed. Surgical resection was possible in 128 patients. The remaining 23 patients had surgical palliative drainage. Local bile duct excision alone was performed in 17 patients. Liver resection for tumor extending to secondary bile ducts or hepatic parenchyma was performed in 111 patients; portal vein resection was necessary in 29 of these 111 patients (26.1%) and pancreatoduodenectomy was combined in 18 patients (16.2%). Seven patients died during hospitalization after liver resection, an operative mortality of 6.3%. Margins of bile duct resection were free of tumor on histologic examination in 4 of the 17 local bile duct excisions, but in 86 of the 111 liver resections. The cumulative survival rate after local bile duct excision was 85.7% at 1 year, 42.9% at 2 years, 21.4% at 3 years, and 0% at 4 years. However, the survival rate after liver resection (excluding operative mortality) was 97.1% at 1 year, 72.8% at 2 years, 55.3% at 3 years, and 24.0% at 5 years. Survival and the percentage of patients with tumor-free resection margins after liver resection were superior to those after local bile duct excision. Resection of hilar bile duct carcinoma offers long-term survival only when surgery is aggressive and includes liver resection.

One hundred and eleven liver resections for hilar bile duct cancer

A positive correlation between absence of residual tumor at resection margins and long-term survival in the treatment of hilar bile duct carcinoma has encouraged some surgeons to use a more radical approach, including liver/portal vein resection and combined pancreatoduodenectomy. However, if liver resection is associated with significant morbidity and mortality, it may not produce any overall benefit. This review was undertaken in an attempt to determine whether liver resection is a safe procedure and whether if has any beneficial effect over that of local bile duct excision alone, in terms of achieving curative resection and long-term survival. The records of 151 patients with hilar bile duct carcinoma surgically treated between June 1989 and December 1997 at the Asan Medical Center, Seoul, were retrospectively analyzed. Surgical resection was possible in 128 patients. The remaining 23 patients had surgical palliative drainage. Local bile duct excision alone was performed in 17 patients. Liver resection for tumor extending to secondary bile ducts or hepatic parenchyma was performed in 111 patients; portal vein resection was necessary in 29 of these 111 patients (26.1%) and pancreatoduodenectomy was combined in 18 patients (16.2%). Seven patients died during hospitalization after liver resection, an operative mortality of 6.3%. Margins of bile duct resection were free of tumor on histologic examination in 4 of the 17 local bile duct excisions, but in 86 of the 111 liver resections. The cumulative survival rate after local bile duct excision was 85.7% at 1 year, 42.9% at 2 years, 21.4% at 3 years, and 0% at 4 years. However, the survival rate after liver resection (excluding operative mortality) was 97.1% at 1 year, 72.8% at 2 years, 55.3% at 3 years, and 24.0% at 5 years. Survival and the percentage of patients with tumor-free resection margins after liver resection were superior to those after local bile duct excision. Resection of hilar bile duct carcinoma offers long-term survival only when surgery is aggressive and includes liver resection.

Intactness of zona pellucida does not affect the secretion of a trypsin-like protease from mouse blastocyst

Assisted hatching (AH), which is known to improve the hatching potential of mammalian embryos, has been used to increase the pregnancy rate in in vitro fertilization cycles. However, the effect of AH on a trypsin-like protease, which is known to be associated with the hatching process, has not been studied. In this study, we evaluate whether the intactness of zona pellucida affects the secretion of a trypsin-like protease from mouse blastocyst. Four- to 8-cell stage mouse embryos were collected at 66- to 68 hr after hCG injection and divided into 3 groups according to the manipulation of zona pellucida. The groups are no treatment (control), drilling of zona pellucida (ZD) and thinning of zona pellucida (ZT). The activity of a trypsin-like protease, blastocyst development and hatching rate were compared among the three groups at 110 and 135 hr after hCG injection, respectively. The protease activity and blastocyst development were not significantly different among control, ZD and ZT groups at 110 and 135 hr after hCG injection, respectively. However, the hatching rate of ZD and ZT groups was significantly higher than that of control group at each time, respectively (p<0.001). Even in the zona pellucida removed embryos, the protease activity did not differ from the control group. In conclusion, the secretion of a trypsin-like protease from mouse blastocyst does not seem to be affected by the intactness of zona pellucida.

Molecular lens of the nonresonant dipole force

A cylindrical molecular lens is formed by focusing a nanosecond IR laser pulse. Trajectories of a CS2 molecular beam deflected by the lens are traced using the velocity map imaging technique. The characteristic lens parameters including the focal length, minimum beam width, and distance to the minimum-width position are determined. The laser intensity dependence of the parameters is in good agreement with theoretical predictions. Exciting possibilities for molecular optics and a new type of optical chromatography are opened up.

Timely translation during the mouse oocyte-to-embryo transition

In the mouse, completion of oocyte maturation and the initiation of preimplantation development occur during transcriptional silence and depend on the presence and translation of stored mRNAs transcribed in the growing oocyte. The Spin gene has three transcripts, each with an identical open reading frame and a different 3′ untranslated region (UTR). (Beta)-galactosidase-tagged reporter transcripts containing each of the different Spin 3′UTRs were injected into oocytes and zygotes and (beta)-galactosidase activity was monitored. Results from these experiments suggest that differential polyadenylation and translation occurs at two critical points in the oocyte-to-embryo transition - upon oocyte maturation and fertilization - and is dependent on sequences in the 3′UTR. The stability and mobility shifts of ten other maternal transcripts were monitored by reprobing a northern blot of oocytes and embryos collected at 12 hour intervals after fertilization. Some are more stable than others and the upward mobility shift associated with polyadenylation correlates with the presence of cytoplasmic polyadenylation elements (CPEs) within about 120 nucleotides of the nuclear polyadenylation signal. A survey of the 3′ UTRs of expressed sequence tag clusters from a mouse 2-cell stage cDNA library indicates that about one third contain CPEs. We suggest that differential transcript stability and a translational control program can supply the diversity of protein products necessary for oocyte maturation and the initiation of development.

Effect of dosing time on the total intestinal transit time of non-disintegrating systems

The total gastrointestinal transit time of nondisintegrating tablets may be affected by dosing time; available literature on this topic is inconclusive. OROS systems are nondisintegrating osmotically driven tablets that release drug over a period of time during their transit through the gastrointestinal tract and are excreted intact in the feces. Total transit times following morning administration of OROS systems pooled from various studies (n = 1,163 systems) showed a distribution with peak frequencies clustering around 24 and 48 h and following night administration (n = 80 systems) was found to cluster around 12 and 36 h. The total transit time distribution appears to be different following morning and night administration. However, on reanalyzing the data considering clock time when the tablet was collected rather than time post-administration, most of the difference between the distribution patterns disappeared. This suggested that total transit times after morning or night administration may be related to the bowel movement habits of the study population. Therefore, OROS systems total transit time were compared to the intrinsic bowel movement pattern of the general population reported in the literature and indeed a good correlation was seen between the two. The total transit time appears to be determined by two factors: the defecation frequency and the probability of its inclusion in the defecation event which is related to its location in the GI tract. A tablet is more likely to be excreted if it is further down in the GI tract. The total transit time data for OROS systems suggest that with the morning dosing the tablet is more likely to be excreted in the bowel movement the next morning. With the night time dosing the tablet may not be far enough in the colon to be excreted in the next morning bowel movement and therefore, it is more likely to be excreted the following morning.

Effects of electric stimulation on bovine oocyte activation and embryo development in intracytoplasmic sperm injection procedure

PURPOSE

This study was carried out to investigate the efficacy of electric stimulation before and/or after intracytoplasmic sperm injection (ICSI) on bovine oocyte activation and embryo development.

METHODS

The oocytes were treated with electric shock before (B), before and after (B&A), and after (A) sperm injection. In each group, sham ICSI (ICSI-s) was performed to exclude the effect of parthenogenesis (B ICSI-s, B&A ICSI-s, and A ICSI-s). An electric pulse was applied with a single direct current (DC) pulse (0.8 kV/cm, 70 microseconds).

RESULTS

One pronucleus (PN) formation in the B&A ICSI-s group was slightly higher than that found in B and B&A ICSI group; however, the difference was not significant. Two PN formation in B&A ICSI group was higher than that found in sham ICSI groups (P < 0.05). There were no differences among treatment groups in the cleavage rate; however, morulae and blastocyst formation in the B&A embryos was significantly higher than that of other groups (P < 0.05) and got pregnant.

CONCLUSIONS

Electric stimulation before and after injection was an effective method in inducing bovine oocyte activation and in sustaining embryo development to the morulae and blastocyst stage.

Involvement of brassinosteroids in the gravitropic response of primary root of maize

Exogenously applied brassinolide (BL, 10(-9)-10(-5) M) increased gravitropic curvature in maize (Zea mays) primary roots. The BL-enhanced gravitropic curvature was clearly promoted in the presence of indole-3-acetic acid (IAA, 10(-10)-10(-8) M), indicating that BL is interactive with IAA during the gravitropic response. The interactive effect between BL and IAA was completely diminished by treatment of p-chlorophenoxy isobutric acid, an auxin action antagonist. The activation of the gravitropic response by BL in the absence and in the presence of IAA was nullified by application of 2, 3,5-triiodobenzoic acid, a polar auxin transport inhibitor. The data indicate that brassinosteroids (BRs) might be involved in auxin-mediated processes for the gravitropic response. Gas chromotography-selected ion-monitoring analysis revealed that maize primary roots contained approximately 0.3 ng g(-1) fresh weight castasterone as an endogenous BR. Exogenously applied castasterone also increased the gravitropic response of maize roots in an IAA-dependent manner. This study provides the first evidence, to our knowledge, for occurrence and gravitropic activity of BRs in plant roots.

Development of a web-based picture archiving and communication system using satellite data communication

Using the JAVA language we have developed a Web-based picture archiving and communication system (PACS) which allows a remote hospital to access medical images. An asymmetric satellite data communication system (ASDCS) provided a receive-only link for data delivery and a conventional terrestrial link (which could be the conventional telephone network) allowed data transmission. The satellite communication link was 10-30 times faster than the conventional terrestrial link. To increase image transmission speeds over the Internet connection, JPEG and wavelet compression methods were used. The resulting images were evaluated quantitatively by measuring the peak signal:noise ratio and qualitatively by radiologists. Compression ratios of 10:1 or less were deemed acceptable for diagnostic purposes. The system appears to be suitable for teleradiology and telemedicine.

Beta-globin YAC transgenes exhibit uniform expression levels but position effect variegation in mice

Expression of a construct integrated at different genomic locations often varies because of position effects that have been subcategorized as stable (decreased level of expression) and variegating (decreased proportion of expressing cells). It is well established that locus control regions (LCRs) generally overcome position effects in transgenes. However, whether stable and variegated position effects are equally overcome by an intact LCR has not been determined. We report that single-copy yeast artificial chromosome transgenes containing an unmodified human beta -globin locus were not subject to detectable stable position effects but did undergo mild to severe variegating position effects at three of the four non-centromeric integration sites tested. We also find that, at a given integration site, the distance and the orientation of the LCR relative to the regulated gene contributes to the likelihood of variegating position effects, and can affect the magnitude of its transcriptional enhancement. DNase I hypersensitive site (HSS) formation varies with the proportion of expressing cells, not the level of gene expression, suggesting that silencing of the transgene is associated with a lack of HSS formation in the LCR region. We conclude that transcriptional enhancement and variegating position effects are caused by fundamentally different but inter-dependent mechanisms.

Ligand binding inhibitors of A1 adenosine receptor from Rana rugosa are phospholipase A2s

Inhibitors of the A1 adenosine receptor were isolated from the skin extract of Korean frog, Rana rugosa. The frog-skin extract was prepared by an electrical shock and fractionated with C4 followed by C18 reverse-phase HPLC. Two A1 receptor inhibitors were isolated using a filter binding assay and the molecular masses of the proteins were estimated by matrix-assisted laser desorption ionization time-of-flight mass spectrometry to be 15 347 and 15 404 Da, respectively. The inhibitory activity was also measured against other membrane receptors, such as the A2 adenosine receptor, muscarinic acetylcholine receptor and capsaicin receptor. Ligand binding to the A2 and muscarinic receptors was also severely inhibited by these proteins. However, they did not inhibit the functional activation of the capsaicin receptor by its ligand, capsaicin, suggesting that inhibition of ligand-receptor binding occurs specifically. Their N-terminal sequences were determined by Edman degradation. Surprisingly, they showed sequence similarity to the secretory protein, phospholipase A2 from various organisms. The phospholipase A2 activity of both proteins was tested using Dole's assay technique. Both proteins showed phospholipase A2 activity, and therefore, they were designated as PLA2-R1 and PLA2-R2, respectively. In addition, their ligand-binding inhibitory activity depended on their phospholipase A2 activity. This is the first finding that the frog secretes a phospholipase A2 similar to that of snake venoms, which posess inhibitory activity against the adenosine A1, adenosine A2 and muscarinic receptors.

The housing/health relationship: what do we know?

Research into the relationship between housing and health has frequently been narrowly focused, fragmented, and of marginal practical relevance to either housing or health policy. From an extensive review of the literature, this paper reports on the current state of knowledge about the relationship between housing and health. The research falls into four distinct categories: (1) specific physical or chemical exposures; (2) specific biological exposures; (3) physical characteristics of the house; and (4) social, economic, and cultural characteristics of housing. Much of the general literature on the effects of housing on health cites previous studies and then proceeds to advocate housing policies and strategies that are aimed at improving population health. Studies providing original data on the relationship, which is the vast majority of the literature, focus on very specific physical, chemical, and biological exposures with a known or suspected effect on health within the house, or they focus on the social, economic, and cultural characteristics of the house. The mechanisms through which specific aspects of housing affect health are extremely complicated, but they do exist. Researchers have made a great deal of progress in clarifying some of these mechanisms. A large gap still exists in our knowledge about the links and pathways between housing, socio-economic status and health status.

The clinical usefulness of F-18 FDG coincidence PET without attenuation correction and without whole-body scanning mode in pulmonary lesions comparison with CT, MRI, and clinical findings

PURPOSE

This study was undertaken to assess the clinical usefulness of fluorine-18 flurodeoxyglucose (F-18 FDG) coincidence detection (CoDe) positron emission tomography (PET) of various lung lesions by comparing it with CT, MRI, and clinical findings.

MATERIALS AND METHODS

Forty-two patients with pulmonary lesions underwent CoDe PET using a dual-head gamma camera equipped with a 5/8 inch thick NaI (Tl) crystals. The patients were prepared for the study by overnight fasting. Data was acquired at approximately 1 hour after the intravenous injection of 111 to 370 MBq (3 to 10 mCi) of F-18 FDG. A spinal scan of the thorax was performed using a slip ring gantry for 30 minutes. After rebinning, routine tomographic slices were reconstructed without attenuation correction and the images were analyzed visually.

RESULTS

Pathologic diagnoses and staging were obtained at surgery in nine patients; in the remaining 33 patients, aspiration cytology was available. CoDe PET detected all 35 pathologically proved malignant lesions. In nine patients who underwent surgery, seven CoDe PET studies corresponded with pathologic staging, whereas in six of the nine patients, CT and MRI corresponded with the pathologic findings. Seven patients also had benign lesions that showed FDG uptake.

CONCLUSIONS

F-18 FDG CoDe PET was sensitive in the evaluation of lung lesions but was not specific for malignancy. F-18 FDG CoDe PET was more sensitive than CT and MRI in nodal staging in the limited number of patients studied thus far.

Inhibition of gene expression in human cells through small molecule-RNA interactions

Small molecules that bind their biological receptors with high affinity and selectivity can be isolated from randomized pools of combinatorial libraries. RNA-protein interactions are important in many cellular functions, including transcription, RNA splicing, and translation. One example of such interactions is the mechanism of trans-activation of HIV-1 gene expression that requires the interaction of Tat protein with the trans-activation responsive region (TAR) RNA, a 59-base stem-loop structure located at the 5' end of all nascent HIV-1 transcripts. Here we demonstrate the isolation of small TAR RNA-binding molecules from an encoded combinatorial library. We have made an encoded combinatorial tripeptide library of 24,389 possible members from D-and L-alpha amino acids on TentaGel resin. Using on-bead screening we have identified a small family of mostly heterochiral tripeptides capable of structure-specific binding to the bulge loop of TAR RNA. In vitro binding studies reveal stereospecific discrimination when the best tripeptide ligand is compared with diastereomeric peptide sequences. In addition, the most strongly binding tripeptide was shown to suppress transcriptional activation by Tat protein in human cells with an IC(50) of approximately 50 nM. Our results indicate that tripeptide RNA ligands are cell permeable, nontoxic to cells, and capable of inhibiting expression of specific genes by interfering with RNA-protein interactions.