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PubMed2001

Antisense oligodeoxynucleotide-induced suppression of basal forebrain NMDA-NR1 subunits selectively impairs visual attentional performance in rats.

UNLABELLED: It is generally agreed that basal forebrain neuronal circuits contribute to the mediation of the ability to detect, select and discriminate signals, to suppress the processing of irrelevant information, and to allocate processing resources to competing tasks. Rats were trained in a task designed to assess sustained attention, or in a cued discrimination task that did not tax attentional processes. Animals were equipped with guide cannula to infuse bilaterally antisense oligodeoxynucleotides (ODNs) against the N-methyl-D-aspartate (NMDA) NR1 subunits, or missense ODNs, into the substantia innominata of the basal forebrain. Infusions of antisense or missense ODNs did not affect cued visual discrimination performance. Infusions of antisense ODNs dose-dependently impaired sustained attention performance by selectively decreasing the animals' ability to detect signals while their ability to reject nonsignal trials remained unchanged. The detrimental attentional effects of antisense infusions were maximal 24 h after the third and final infusion, and performance returned to baseline 24 h later. Missense infusions did not affect attentional performance. Separate experiments demonstrated extensive suppression of NR1 subunit immunoreactivity in the substantia innominata. Furthermore, infusions of antisense did not produce neurotoxic effects in that region as demonstrated by the Fluoro-Jade METHOD: The present data support the hypothesis that NMDA receptor (NMDAR) stimulation in the basal forebrain, largely via glutamatergic inputs originating in the prefrontal cortex, represents a necessary mechanism to activate the basal forebrain corticopetal system for mediation of attentional performance.

Animals↗

PubMed2025

Efficient CRISPR/Cas9-mediated genome editing of phytoene desaturase in Musa-AAA: a critical step for genetic improvement of east African highland bananas.

East African highland bananas (EAHBs), locally referred to as "matooke", are an important staple crop in Uganda. The EAHBs have a triploid genome (AAA) with a large phenotypic diversity in the Great Lakes region of Africa and are challenged by both abiotic and biotic factors. The EAHBs have been improved through conventional breeding and genetic engineering though facing challenges such as genetic drag of unfavorable traits and complex regulatory processes, respectively. Therefore, a more precise approach for crop improvement such as genome editing is highly recommended. In the current study, we assessed the feasibility and applicability of the CRISPR/Cas9 mediated-genome editing in EAHBs. Two sgRNAs were designed from the Nakitembe phytoene desaturase (PDS) gene and used to edit the PDS gene in Nakitembe (NKT) and NAROBan5 (M30) cultivars. A total of 47 NKT and 130 M30 events were regenerated via agrobacterium-mediated transformation of banana embryogenic cell suspensions. Up to 100% and 94.6% albinism rates were observed in Nakitembe and M30 cultivars respectively with additional albino-variegated and variegated phenotypes observed in M30 only. Carotenoid analysis revealed a significant reduction of total carotenoid content in edited events with all complete albinos showing no detectable carotenoids implying that the carotenoid biosynthetic pathway was effectively disrupted. Sequence analysis revealed that all of the edited events had frameshift mutations leading to PDS disruption. Overall, this study presents the first report of CRISPR/Cas9 genome editing in EAHBs and more interestingly on a hybrid, M30 showing high precision and efficiency. This validated genome editing system provides a robust platform for targeted EAHB improvement.

CRISPR/Cas9↗

PubMed2001

Guiding ribozyme cleavage through motif recognition: the mechanism of cleavage site selection by a group ii intron ribozyme.

The mechanism by which group II introns cleave the correct phosphodiester linkage was investigated by studying the reaction of mutant substrates with a ribozyme derived from intron ai5gamma. While fidelity was found to be quite high in most cases, a single mutation on the substrate (+1C) resulted in a dramatic loss of fidelity. When this mutation was combined with a second mutation that induces a bulge in the exon binding site 1/intron binding site 1 (EBS1/IBS1) duplex, the base-pairing register of the EBS1/IBS1 duplex was shifted and the cleavage site moved to a downstream position on the substrate. Conversely, when mismatches were incorporated at the EBS1/IBS1 terminus, the duplex was effectively truncated and cleavage occurred at an upstream site. Taken together, these data demonstrate that the cleavage site of a group II intron ribozyme can be tuned at will by manipulating the thermodynamic stability and structure of the EBS1/IBS1 pairing. The results are consistent with a model in which the cleavage site is not designated through recognition of specific nucleotides (such as the 5'-terminal residue of EBS1). Instead, the ribozyme detects a structure at the junction between single and double-stranded residues on the bound substrate. This finding explains the puzzling lack of phylogenetic conservation in ribozyme and substrate sequences near group II intron target sites.

Base Pair Mismatch↗

PubMed2004

Is a lymph node detected by the dye-guided method a true sentinel node in gastric cancer?

PURPOSE: A sentinel node is defined as the initial lymph node, to which cancer cells metastasize from a primary tumor. Recently, sentinel node navigation surgery has been done using the dye-guided method. However, no study has shown that a lymph node detected by the dye-guided method is the true sentinel node from the viewpoint of micrometastasis. Micrometastases of lymph nodes, in which no metastasis was found by H&E staining, were examined to establish whether a lymph node detected by the dye-guided method is the true sentinel node. EXPERIMENTAL DESIGN: Isosulfan blue was injected endoscopically as the dye-guided method at a submucosal lesion of early gastric cancer. Total 345 lymph nodes, including 150 blue-dyed lymph nodes and 195 nondyed lymph nodes were collected from 57 patients and each was quartered. Two quarters were examined histologically by H&E staining and cytokeratin staining. The other specimens were used for quantitative reverse transcription-PCR of CEA and CK20 mRNAs. RESULTS: Lymph node disease was not found in any of 345 lymph nodes from the 57 patients by routine H&E staining. By contrast, either CEA or CK20 mRNA expression was detected in 21 of 345 lymph nodes obtained from the 10 (18%) of 57 patients by quantitative reverse transcription-PCR. Eight of the 21 micrometastasis-positive lymph nodes were confirmed to be positive for cytokeratin staining. Although micrometastasis of nondyed lymph nodes was found in three cases, these were included in the 10 cases with micrometastasis of blue-dyed nodes, such that there was no patient who only had micrometastasis in nondyed nodes. Six of 10 cases were micrometastasis-positive in a single node; all six were blue-dyed nodes. CONCLUSION: A lymph node detected by the dye-guided method should be a true sentinel node to which cancer cells metastasize initially.

Adult↗

PubMed2000

A genotypic analysis of patients receiving Zidovudine with either Lamivudine, Didanosine or Zalcitabine dual therapy using the LiPA point mutation assay to detect genotypic variation at codons 41, 69, 70, 74, 184 and 215.

BACKGROUND: The Murex-Innogenetics LiPA HIV-1 RT assay can be used to identify the presence of mutations of the reverse transcriptase gene at codons 41, 69, 70, 74, 184 and 215 of HIV-1, which have been shown to confer resistance to the nucleoside analogs Zidovudine (ZDV), Lamivudine (3TC), Didanosine (ddI) and Zalcitabine (ddC). The M184V mutation of the reverse transcriptase gene of HIV-1 has been associated with resistance to 3TC, ddC and ddI. This mutation has also been observed in patients receiving ZDV+ddC and ZDV+ddI. We used LiPA HIV-1 RT assay to identify the presence of either consensus methionine 184 or the mutant valine 184 with three groups of patients who were treated with ZDV/3TC, ZDV/ddI or ZDV/ddC combination therapy. OBJECTIVES: The aim of our study was to determine the viral genotype of patients who were considered to be failing therapy, by two ways: using sequencing and LiPA assays. In particular we were interested in establishing a possible correlation between these methods. STUDY DESIGN: The study group consisted of a consecutive series of 33 patients with a treatment failure, 18 of whom received ZDV+3TC therapy, seven received ZDV+ddI and eight received ZDV+ddC therapy. We also examined a small cohort of seven seroconverters. RESULTS: The M184V mutation was observed in 47.0% of patients receiving ZDV+3TC combination therapy but was not observed in either patient group receiving either ddI or ddC as co-therapy with ZDV. There was no evidence of the L74V mutation in our study group in either the ZDV/ddI or ZDV/ddC combination therapy group. We found the frequency of the K70R mutation to be higher in patients treated with ZDV/ddI (P=0.033) or ZDV/ddC (P=0.3) when compared with patients treated with ZDV/3TC. CONCLUSION: The LiPA assay allowed for the rapid detection of wild type and amino acid variations at key positions conferring resistance to the most used antiviral RT inhibitors. This represented a rapid, quite sensitive, and simple genotyping test. For these reasons the LiPA assay proved to be useful in studying genetic resistance in large screenings, when key RT mutations could be useful in guiding an effective HIV-1 suppressing regimen.

Anti-HIV Agents↗

PubMed2006

Detection by broad-range real-time PCR assay of Chlamydia species infecting human and animals.

BACKGROUND: Tests available for molecular diagnosis of chlamydial infections detect Chlamydiatrachomatis, but do not find other Chlamydia species associated with genital, ophthalmic, cardiovascular, respiratory or neurological diseases. The routine detection of all Chlamydia species would improve the prognosis of infected people and guide therapeutic choices. AIM: To design and validate a sensitive, specific, reproducible, inexpensive and easy-to-perform assay to quantify most Chlamydia species. METHODS: Primers and probe were selected using the gene coding for the 16S rRNA. The detection limits were assessed for suspensions of Chlamydia trachomatis, Chlamydia psittaci and Chlamydia pneumoniae. The performance of this test was compared with that of two commercial kits (Amplicor-Roche and Artus) on 100 samples obtained from children with trachoma. RESULTS: The detection capacities for Chlamydia trachomatis of the broad-range real-time polymerase chain reaction (PCR) were similar or slightly better than those obtained with commercial kits (0.2 copies of DNA/microl). Only the broad-range PCR identified specimens containing Chlamydia psittaci and Chlamydia pneumoniae. The commercial kits and the broad-range assay detected Chlamydia species in 5% and in 11%, respectively, of samples from children with trachoma. CONCLUSIONS: This new real-time PCR offers a sensitive, reproducible assay that produces results in <3 h. With panels of quantified Chlamydia species, this real-time PCR can be run with all real-time PCR equipment. Larger trials are needed to confirm the utility of this test in diagnosis and for therapeutic follow-up.

Animals↗

PubMed1999

Human endothelium: endovascular biopsy and molecular analysis.

PURPOSE: To develop a safe and reproducible method for harvesting viable vascular endothelium to analyze gene expression at sites of vascular lesions. MATERIALS AND METHODS: Coaxial curved stainless-steel guide wires were used to obtain samples of endothelial cells from large arteries and veins in 29 patients undergoing routine endovascular procedures. Three immunocytochemical markers were used to identify cells as endothelial. Cellular viability was evaluated in terms of cell membrane integrity, energy-dependent uptake of acetylated low-density lipoprotein, and cellular response to lipopolysaccharide. Single-cell reverse transcription polymerase chain reaction (PCR) and immunocytochemistry were used to study endothelial gene expression. RESULTS: Cells with endothelial morphology and immunoreactivity for von Willebrand factor, thrombomodulin, and angiotensin-converting enzyme were consistently obtained from iliac and carotid arteries and large veins (average yield [+/- standard error] from 26 iliac arteries, 262 endothelial cells +/- 45, 20%-30% of which were viable). These cells displayed induction of E-selection messenger RNA at PCR after exposure to lipopolysaccharide. Expression of vascular cell adhesion molecule 1 transcripts in endothelial cells increased with patient age (P < .01), whereas expression of intercellular adhesion molecule 1 did not. CONCLUSION: Viable endothelium can be obtained during routine angiography. Immunocytochemical and reverse transcription PCR analyses of these cells allowed determination of transcripts and proteins expressed by endothelium at sites of vascular lesions. Such information could aid in understanding mechanisms of vascular diseases and in clinical decision making.

Adolescent↗

PubMed2004

Assessment of production conditions for efficient use of Escherichia coli in high-yield heterologous recombinant selenoprotein synthesis.

The production of heterologous selenoproteins in Escherichia coli necessitates the design of a secondary structure in the mRNA forming a selenocysteine insertion sequence (SECIS) element compatible with SelB, the elongation factor for selenocysteine insertion at a predefined UGA codon. SelB competes with release factor 2 (RF2) catalyzing translational termination at UGA. Stoichiometry between mRNA, the SelB elongation factor, and RF2 is thereby important, whereas other expression conditions affecting the yield of recombinant selenoproteins have been poorly assessed. Here we expressed the rat selenoprotein thioredoxin reductase, with titrated levels of the selenoprotein mRNA under diverse growth conditions, with or without cotransformation of the accessory bacterial selA, selB, and selC genes. Titration of the selenoprotein mRNA with a pBAD promoter was performed in both TOP10 and BW27783 cells, which unexpectedly could not improve yield or specific activity compared to that achieved in our prior studies. Guided by principal component analysis, we instead discovered that the most efficient bacterial selenoprotein production conditions were obtained with the high-transcription T7lac-driven pET vector system in presence of the selA, selB, and selC genes, with induction of production at late exponential phase. About 40 mg of rat thioredoxin reductase with 50% selenocysteine content could thereby be produced per liter bacterial culture. These findings clearly illustrate the ability of E. coli to upregulate the selenocysteine incorporation machinery on demand and that this is furthermore strongly augmented in late exponential phase. This study also demonstrates that E. coli can indeed be utilized as cell factories for highly efficient production of heterologous selenoproteins such as rat thioredoxin reductase.

Arabinose↗

PubMed1996

Gliolectin is a novel carbohydrate-binding protein expressed by a subset of glia in the embryonic Drosophila nervous system.

Interactions between embryonic neural cells generate the specific patterns of connectivity observed in nervous systems. Cell surface carbohydrates have been proposed to function in cellular recognition events guiding such interactions. Carbohydrate-binding proteins (lectins) that recognize specific oligosaccharide ligands in embryonic neural tissue provide a molecular mechanism for carbohydrate-mediated cell-cell interactions in neural development. Therefore, we have screened an embryonic Drosophila melanogaster cDNA library, expressed in COS1 cells, for carbohydrate-binding activity. COS1 cells expressing putative Drosophila lectins were identified and recovered based on their adhesion to immobilized preparations of neutral and zwitterionic glycolipids extracted from Drosophila embryos. We have identified an endogenous lectin expressed during Drosophila embryogenesis. The cloned lectin, designated 'gliolectin', possesses a novel protein sequence with a calculated molecular mass of 24,993. When expressed in Drosophila S2 cells, the lectin mediates heterophilic cellular aggregation. In embryos, gliolectin is expressed by a subset of glial cells found at the midline of the developing nervous system. Expression is highest during the formation of the Drosophila embryonic axonal commissures, a process requiring midline glial cell funcion. Immunoprecipitation with a monoclonal antibody against gliolectin yields a protein of Mr=46,600 from Drosophila embryonic membranes, suggesting that post-translational modification of gliolectin is extensive. Epitope- tagged chimericproteins composed of the amino terminal one-half of gliolectin and the Fc region of human IgG bind a small subset of the total glycolipids extracted from Drosophila embryos, demonstrating that the lectin activity of gliolectin can discriminate between oligosaccharide structures. The presence of gliolectin in the developing Drosophila embryonic nervous system further supports a role for cell surface carbohydrates in cell-cell recognition and indicates that the molecular diversity of animal lectins is not yet completely defined.

Amino Acid Sequence↗

PubMed2004

Kindling stimuli delivered at different times in the sleep-wake cycle.

STUDY OBJECTIVES: Clinical and experimental observations argue that sleep disturbances are common and coexist in patients with epilepsy. Our previous observations have suggested that neural-immune interactions between corticotropin-releasing hormone (CRH) and interleukin-1 (IL-1) are involved in the regulation of physiological sleep-wake behavior. In the present study, we determined the involvement of CRH and IL-1 in the alteration of sleep-wake activities in rats when amygdala kindling was given either at the beginning of the light period (light-onset kindling) or at the beginning of the dark period (dark-onset kindling). DESIGN: The analysis of sleep-wake activities was performed before and after full-blown kindling, and the actions of CRH and IL-1 were tested by pharmacological blockade. SETTING: Neuroscience Laboratory at China Medical University Hospital. PARTICIPANT AND INTERVENTIONS: Male Sprague-Dawley rats were implanted with electroencephalogram (EEG) electrodes and an intracerebroventricular (ICV) guide cannula. Kindling stimuli delivered via a bipolar electrode placing in the right central nucleus of the amygdala. MEASUREMENT AND RESULTS: Amygdala kindling induced diverse effects on sleep. Slow-wave sleep (SWS) and rapid eye movement (REM) sleep decreased during the first 12-hour light period when rats were kindled at light onset. When dark-onset kindling was given, SWS increased but REM sleep was not altered during the first 12-hour dark period. After light-onset kindling, the circulating corticosterone concentrations increased and were blocked by ICV administration of the CRH receptor antagonist, astressin or alpha-hCRH. The ICV administration of the CRH antagonist blocked the light-onset kindling-induced decrease of SWS in a dose-dependent manner. After dark-onset kindling, IL-1 mRNA expression in the hippocampus and cortex increased. The dark-onset kindling-induced SWS was blocked in a dose-dependent manner by ICV administration of IL-1 receptor antagonist (IL-1 ra). The slow-wave activity during SWS was enhanced regardless of when kindling occurred, but both CRH antagonists and IL-1 ra had little effect on the alteration of slow-wave activity. CONCLUSION: These observations argue that amygdala-kindling-induced sleep-wake alterations are modulated by central increases in CRH or IL-1.

Amygdala↗

PubMed2004

Escherichia coli glutaminyl-tRNA synthetase is electrostatically optimized for binding of its cognate substrates.

Natural evolution has resulted in protein molecules displaying a wide range of binding properties that include extremes of affinity and specificity. A detailed understanding of the principles underlying protein structure-function relationships, particularly with respect to binding properties, would greatly enhance molecular engineering and ligand design studies. Here, we have analyzed the interactions of an aminoacyl-tRNA synthetase for which strong evolutionary pressure has enforced high specificity for substrate binding and catalysis. Electrostatic interactions have been identified as one efficient mechanism for enhancing binding specificity; as such, the effects of charged and polar groups were the focus of this study. The binding of glutaminyl-tRNA synthetase from Escherichia coli to several ligands, including the natural substrates, was analyzed. The electrostatic complementarity of the enzyme to its ligands was assessed using measures derived from affinity optimization theory. The results were independent of the details of the calculational parameters, including the value used for the protein dielectric constant. Glutamine and ATP, two of the natural ligands, were found to be extremely complementary to their binding sites, particularly in regions seen to make electrostatic interactions in the structure. These data suggest that the optimization of electrostatic interactions has played an important role in guiding the evolution of this enzyme. The results also show that the enzyme is able to effectively select for high affinity and specificity for the same chemical moieties both in the context of smaller substrates, and in that of a larger reactive intermediate. The regions of greatest non-complementarity between the enzyme and ligands are the portions of the ligand that make few polar contacts with the binding site, as well as the sites of chemical reaction, where overly strong electrostatic binding interactions with the substrate could hinder catalysis. The results also suggest that the negative charge on the phosphorus center of glutaminyl-adenylate plays an important role in the tight binding of this intermediate, and thus that adenylate analogs that preserve the negative charge in this region may bind substantially tighter than analogs where this group is replaced with a neutral group, such as the sulfamoyl family, which can make similar hydrogen bonds but is uncharged.

Adenosine Monophosphate↗

PubMed2003

Myocardin mRNA is augmented in the failing myocardium: expression profiling in the porcine model and human dilated cardiomyopathy.

The implication of myocardin and homeodomain only protein (HOP) in combinatorial molecular pathways that guide heart development and cardio-specific gene expression has recently been reported. However, expression of these genes in the failing heart has not yet been investigated. This study was designed to elaborate a molecular profile of myocardin and HOP expression in the failing ventricular myocardium through the use of both explanted human heart samples and heart biopsies from neonatal piglets with doxorubicin-induced cardiomyopathy (Dox-CM). Myocardin and HOP mRNA levels were estimated by both northern blot hybridization and semiquantitative RT-PCR in human ventricular preparations in end-stage failure due to dilated cardiomyopathy (DCM), as well as in nonfailing donor hearts. Similar experiments were performed with ventricular samples from normal and Dox-treated neonatal piglets. The gene expression of brain natriuretic peptide (BNP) was used as a molecular marker of myocardial damage and failure. The study revealed the following novel findings: (1) myocardin transcripts are detected in neonatal human and pig hearts at lower levels than in mature cardiac tissues, (2) the myocardin transcript pool is significantly augmented in the failing human and porcine myocardium as compared to that in nonfailing heart samples, (3) in the failing human myocardium, increased levels of myocardin mRNA are associated with a diminished HOP transcript content, and (4) the inverse proportion in cardiac myocardin/HOP mRNA pools observed in explanted human hearts is also traceable in normal human heart and aorta. A possible dual consequence of increased myocardin and decreased HOP expression levels on serum response factor-dependent cardiac-specific expression in the normal heart and at heart failure is discussed. Therefore, increased abundance of the myocardin mRNA pool is judged to be a novel CM-related feature which, alone or in association with decreased HOP transcript levels, can be responsible for dysregulation of myocardin-mediated gene expression in failing myocardium.

Amino Acid Sequence↗

PubMed1994

Gene regulation of interleukin-1 beta, interleukin-1 receptor type I, and plasminogen activator inhibitor-1 and -2 in human granulosa-luteal cells.

OBJECTIVE: To investigate the regulation of messenger ribonucleic acid (mRNA) levels of interleukin-1 beta (IL-1 beta), interleukin-1 (IL-1) receptor type 1, and plasminogen activator (PA) inhibitor-1 and -2 in cumulus cells, granulosa-luteal cells, and macrophage-depleted granulosa-luteal cells obtained from human preovulatory follicles. DESIGN: Prospective longitudinal study. SETTING, PATIENTS: Patients undergoing assisted reproductive technologies (ART) in the Department of Gynecology and Obstetrics, Stanford University, Stanford, California. INTERVENTIONS: Cumulus cells and granulosa-luteal cells were collected by ultrasound-guided transvaginal aspiration at the time of ART. MAIN OUTCOME MEASURES: Northern blot analysis of mRNA levels of IL-1 beta, IL-1 receptor type 1, PA inhibitor-1 and -2 in cumulus cells, granulosa-luteal cells and macrophage-depleted granulosa-luteal cells, and indirect immunocytochemical analysis of the IL-1 system and macrophages in granulosa-luteal cell preparations were performed. RESULTS: Interleukin-1 beta mRNA levels in uncultured cumulus cells were less than those of uncultured granulosa-luteal cells with no differences in IL-1 receptor type 1 mRNA levels between these two cell types. Granulosa-luteal cell IL-1 receptor type 1 mRNA levels were expressed constitutively throughout 24 hours of culture with no effect by hCG, whereas IL-1 beta mRNA levels increased within 6 hours, and then remained elevated for 24 hours with no effect by hCG. Interleukin-1 beta significantly increased granulosa-luteal cell mRNA levels of IL-1 beta (over twofold), IL-1 receptor type 1 (over twofold), PA inhibitor-1 (approximately 1.4-fold), and PA inhibitor-2 (approximately 1.6-fold). In contrast, IL-1 beta had no effect on IL-1 beta and IL-1 receptor type 1 mRNA levels in macrophage-depleted granulosa-luteal cells. Granulosa-luteal cells, not macrophages, account for the majority of the immunocytochemical staining for IL-1 beta and IL-1 receptor type 1 in follicular aspirates. CONCLUSIONS: These studies suggest that the IL-1 system is regulated in human granulosa-luteal cells during the periovulatory period. Furthermore, the augmentation of PA inhibitor-1 and -2 mRNA levels by IL-1 beta suggests a potential role for IL-1 beta in remodeling of the human ovary during the periovulatory period.

Adult↗

PubMed2003

Quantitative molecular detection of minimal residual head and neck cancer in lymph node aspirates.

PURPOSE: Staging of the clinically N(0) neck in patients with head and neck squamous cell carcinoma (HNSCC) using ultrasound-guided, fine needle aspiration cytology (USgFNAC) has a false-negative rate of approximately 20% that might be caused by inaccurate cytology. Molecular analysis of aspirate residues might reduce the false-negative rate, and we therefore set up a quantitative reverse transcription-PCR (Q-RT-PCR) assay based on TaqMan technology using the squamous cell-specific antigen E48 (Ly-6D) as molecular marker. EXPERIMENTAL DESIGN: The detection limit of the assay was determined in reconstruction experiments. The sensitivity of the assay was tested on cytological tumor-positive aspirate residues and the specificity on lymph node aspirate residues of noncancer controls. Subsequently, 235 lymph node aspirate residues of 64 HNSCC patients staged with USgFNAC were examined for the presence of E48 mRNA. E48 Q-RT-PCR results of the aspirated lymph nodes were compared with cytology and clinical outcome. RESULTS: The detection limit of E48 Q-RT-PCR was a single tumor cell in a background of 10(6) peripheral blood mononuclear cells. From the 41 aspirates that were not evaluable at cytology, 24 (59%) could be diagnosed with E48 Q-RT-PCR. In the 191 aspirates that were tumor negative or not evaluable at cytology, 8 samples from 6 patients were E48 positive. These results were confirmed by histology or clinical outcome in 3 of 6 patients. E48 Q-RT-PCR showed an increase in sensitivity from 56 to 67% and an increase in frequency of reached diagnosis from 97 to 100% compared with cytology. The specificity decreased from 100 to 92%. CONCLUSIONS: Real-time E48 Q-RT-PCR is an accurate technique for squamous cell detection in lymph node aspirates of HNSCC patients. The assay shows an increase in sensitivity and frequency of reached diagnosis compared with cytology. The test could be implemented routinely in USgFNAC to diagnose cases for which cytological examination is not conclusive.

Base Sequence↗

PubMed1996

Effects of SKF 108922, an HIV-1 protease inhibitor, on retrovirus replication in mice.

Rationally designed synthetic inhibitors of retroviral proteases inhibit the processing of viral polypeptides in cultures of human T lymphocytes infected with human immunodeficiency virus type 1 (HIV-1) and therefore suppress the infectivity of HIV-1 in vitro. We have previously reported the antiviral activity in vitro of HIV-1 protease inhibitors against the C-type retrovirus Rauscher murine leukemia virus (RMuLV) and the lentivirus simian immunodeficiency virus (SIV). The same compounds which blocked the infectivity of HIV-1 also inhibited the infectivity of RMuLV and SIV in vitro. This report extends these findings by testing the antiviral activity of HIV-1 protease inhibitors in vivo in the RMuLV model. RMuLV-infected mice were treated twice a day (bid) with either an active (SKF 108922) or inactive (SKF 109273) compound for fourteen days by the intraperitoneal (i.p.) route. Compared with excipient control, SKF 108922, formulated with hydroxypropyl-beta-cyclodextrin (HPB), reduced virus-induced splenomegaly, viremia, and serum reverse transcriptase (RT) levels, while SKF 109273 was inactive. The HPB vehicle by itself enhanced replication of RMuLV. The effects of changing the formulation and the route of administration were examined. SKF 108922, formulated in HPB, had similar antiviral activity when administered by the i.p. or subcutaneous (SC) routes. However, SKF 108922 administered as a colloidal suspension in cholesterol sulfate (CS) had no detectable antiviral effect. Measurements of the circulating levels of the protease inhibitor in plasma explained this result. Plasma concentrations of SKF 108922 exceeded 1000 nM within 10 min after SC administration of the compound solubilized in HPB, but SKF 108922 was not detected in plasma after SC administration of the same dose formulated with CS. Information on optimal conditions for administering these agents should prove useful in guiding their clinical application Therefore, RMuLV should provide a good model for the preclinical evaluation and development of this class of agents for the treatment of HIV.

2-Hydroxypropyl-beta-cyclodextrin↗

PubMed2000

Phenotypic testing predicts virological response in successive protease inhibitor-based regimens.

OBJECTIVE: To evaluate the importance of the number of active drugs, as determined by phenotypic resistance testing, in achieving virological response in successive salvage regimens. DESIGN: Phenotypic study of 57 plasma samples corresponding to 24 patients who had sequentially received three protease inhibitor-containing regimens. Phenotypic susceptibility to a drug (active drug) was defined as less than a four-fold-increase in the IC50 in comparison with the wild type. MAIN OUTCOME MEASURE: Virological response according to the number of active drugs (three versus two or fewer), HIV load, length of antiretroviral exposure, and line of protease inhibitor-based therapy (first, second and third regimen). RESULTS: Before the first protease inhibitor-based therapy, the median time on antiretroviral treatment was 42 months, and before the second and third protease inhibitor-salvage regimens it was 10 and 8 months, respectively. The number of patients receiving three active drugs simultaneously was 24, 35 and 31% in each line of therapy. At week 12, a close correlation was found between the presence of three active drugs in the antiretroviral regimen and the rate of virological response, in comparison with those patients receiving two or fewer active drugs [76 versus 45%, relative risk (RR), 1.7; 95% confidence interval (CI) 1.1-2.6; P = 0.028]. In a multivariate analysis, the use of two or fewer active drugs was an independent predictor of lack of response, regardless of HIV load, length of previous antiretroviral exposure and line of salvage therapy (RR, 4.5; 95%CI, 1.1-18.3; P = 0.03). Of note, a higher rate of response was observed in patients receiving the first protease inhibitor-containing regimen in comparison with those in subsequent protease inhibitor-based salvage regimens (83 versus 50 versus 28%, P < 0.01), even when only those patients receiving three active drugs were included (100 versus 71 versus 60%). CONCLUSIONS: This data confirm the usefulness of phenotypic testing in guiding antiretroviral therapy in heavily pretreated patients. The number of active drugs and the line of salvage therapy are independent predictors of virological response, regardless of HIV load and the length of antiretroviral exposure.

Anti-HIV Agents↗

PubMed2026

RBM20 Truncating Variants and Human Cardiomyopathy.

IMPORTANCE: Genetic diagnosis has become increasingly important to guide clinical decision-making for patients with dilated cardiomyopathy (DCM). Pathogenic or likely pathogenic (P/LP) missense variants in the gene RBM20 cause a highly penetrant arrhythmogenic DCM, but the role of RBM20 truncating variants (RBM20tvs) is unclear. OBJECTIVE: To assess the contribution of RBM20 variants to arrhythmogenic DCM. DESIGN, SETTING, AND PARTICIPANTS: In this cohort study, participants in the genome-first UK Biobank (UKB) and All of Us populations were evaluated to assess the etiologic fraction, natural history and penetrance of RBM20 variants. Retrospective data were collected from an international cohort of patients with DCM and RBM20 variants identified at centers of excellence for genetic heart disease and compared based on time to event. Study dates are not disclosed because the institutional review board did not authorize the sharing of this information. EXPOSURES: RBM20 variants were compared to known P/LP variants and variants of uncertain significance in RBM20 as well as titin truncating variants (TTNtvs). MAIN OUTCOMES AND MEASURES: Major ventricular arrhythmias, end-stage heart failure, and heart failure hospitalization as measured by medical record review (retrospective cohort) and diagnostic codes (UKB). RESULTS: Two main cohorts were studied for this project. In UK Biobank, a cohort of participants with RBM20tvs, RBM20 synonymous variants, and TTNtvs was studied. Of these 4249 participants, 1869 (44%) were male. The mean (SD) age at enrollment was 56 (8.2) years. In the RBM20 registry, of 179 patients, 105 (58.6%) were male, and the mean (SD) age at enrollment was 43.8 (19.1) years. A validation cohort from the All of Us biobank was also used. This consisted of 7002 participants, 4342 of whom (62.0%) were male, and the mean (SD) age was 52.7 (16.7) years. The etiologic fraction of RBM20 variants in arrhythmogenic DCM was 0.53 (95% CI, 0.32-0.67; P < .001). In genome-first biobanks, lifetime incidence of cardiomyopathy, heart failure, or major ventricular arrhythmia diagnosis was lower in participants with RBM20 variants than in those with TTNtvs (hazard ratio, 0.55; 95% CI, 0.36-0.84; P < .001). Patients with RBM20tvs and DCM presented to referral centers later in life than those with P/LP RBM20 and DCM (mean [SD], 53 [10] vs 34 [18] years; P < .001) and were less likely to have a family history of sudden cardiac arrest (2 of 10 [20%] vs 11 of 17 [65%]; P = .046) or cardiomyopathy (2 of 10 [20%] vs 14 of 18 [78%]; P < .001). There was no significant difference in age- and sex-adjusted incident major heart failure or arrhythmia events between patients with RBM20tv and DCM or those with P/LP RBM20 and DCM, though sex-adjusted lifetime hazard was reduced in those with RBM20tv and DCM (hazard ratio, 0.13; 95% CI, 0.03-0.56; P = .01). CONCLUSIONS AND RELEVANCE: This study found that RBM20 variants contributed to arrhythmogenic DCM phenotypes but conferred reduced lifetime disease penetrance compared to TTNtvs and milder disease severity alone than P/LP RBM20 variants. Their potential for additive interactions with other damaging variants should be considered in patients with DCM and their families.

Humans↗

PubMed2002

Radiosurgery for residual or recurrent nonfunctioning pituitary adenoma.

OBJECT: Nonfunctioning pituitary adenomas comprise approximately 30% of all pituitary tumors. The purpose of this retrospective study is to evaluate the efficacy and role of gamma knife radiosurgery (GKS) in the management of residual or recurrent nonfunctioning pituitary adenomas. METHODS: A review was conducted of the data obtained in 42 patients who underwent adjuvant GKS at the University of Pittsburgh between 1987 and 2001. Prior treatments included transsphenoidal resection, craniotomy and resection, or conventional radiotherapy. Endocrinological, ophthalmological, and radiological responses were evaluated. The duration of follow-up review varied from 6 to 102 months (mean 31.2 months). Fifteen patients were observed for more than 40 months. The mean radiation dose to the tumor margin was 16 Gy. Conformal radiosurgery planning was used to restrict the dose to the optic nerve and chiasm. Tumor control after GKS was achieved in 100% of patients with microadenomas and 97% of patients with macroadenomas. Gamma knife radiosurgery was equally effective in controlling adenomas with cavernous sinus invasion and suprasellar extension. No patient developed a new endocrinological deficiency following GKS. One patient's tumor enlarged with an associated decline in visual function. Another patient experienced a deterioration of visual fields despite a decrease in tumor size. CONCLUSIONS: Gamma knife radiosurgery can achieve tumor control in virtually all residual or recurrent nonfunctioning pituitary adenomas. Dose sparing facilitates tumor management even when the adenoma is close to the optic apparatus or invades the cavernous sinus.

Adenoma↗