Massively parallel profiling of RNA-targeting CRISPR-Cas13d

CRISPR-Cas13d cleaves RNA and is used in vivo and for diagnostics. However, a systematic understanding of its RNA binding and cleavage specificity is lacking. Here, we describe an RNA Chip-Hybridized Association-Mapping Platform (RNA-CHAMP) for measuring the binding affinity for > 10,000 RNAs containing structural perturbations and other alterations relative to the CRISPR RNA (crRNA). Deep profiling of Cas13d reveals that it does not require a protospacer flanking sequence but is exquisitely sensitive to secondary structure within the target RNA. Cas13d binding is penalized by mismatches in the distal crRNA-target RNA region, while alterations in the proximal region inhibit nuclease activity. A biophysical model built from these data reveals that target recognition initiates in the distal end of the target RNA. Using this model, we design crRNAs that can differentiate between SARS-CoV-2 variants by modulating nuclease activation. This work describes the key determinants of RNA targeting by a type VI CRISPR enzyme.

Erratum: ^{27}Al^{+} Quantum-Logic Clock with a Systematic Uncertainty below 10^{-18} [Phys. Rev. Lett. 123, 033201 (2019)]

This corrects the article DOI: 10.1103/PhysRevLett.123.033201.

Massively Parallel Profiling of RNA-targeting CRISPR-Cas13d

Type VI CRISPR enzymes cleave target RNAs and are widely used for gene regulation, RNA tracking, and diagnostics. However, a systematic understanding of their RNA binding specificity and cleavage activation is lacking. Here, we describe RNA chip-hybridized association-mapping platform (RNA-CHAMP), a massively parallel platform that repurposes next-generation DNA sequencing chips to measure the binding affinity for over 10,000 RNA targets containing structural perturbations, mismatches, insertions, and deletions relative to the CRISPR RNA (crRNA). Deep profiling of Cas13d, a compact and widely used RNA nuclease, reveals that it does not require a protospacer flanking sequence (PFS) but is exquisitely sensitive to secondary structure within the target RNA. Cas13d binding is strongly penalized by mismatches, insertions, and deletions in the distal crRNA-target RNA regions, while alterations in the proximal region inhibit nuclease activity without affecting binding. A biophysical model built from these data reveals that target recognition begins at the distal end of unstructured target RNAs and proceeds to the proximal end. Using this model, we designed a series of partially mismatched guide RNAs that modulate nuclease activity to detect single nucleotide polymorphisms (SNPs) in circulating SARS-CoV-2 variants. This work describes the key determinants of RNA targeting by a type VI CRISPR enzyme to improve CRISPR diagnostics and in vivo RNA editing. More broadly, RNA-CHAMP provides a quantitative platform for systematically measuring protein-RNA interactions.

Antibody escape and cryptic cross-domain stabilization in the SARS-CoV-2 Omicron spike protein

The worldwide spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has led to the repeated emergence of variants of concern. For the Omicron variant, sub-lineages BA.1 and BA.2, respectively, contain 33 and 29 nonsynonymous and indel spike protein mutations. These amino acid substitutions and indels are implicated in increased transmissibility and enhanced immune evasion. By reverting individual spike mutations of BA.1 or BA.2, we characterize the molecular effects of the Omicron spike mutations on expression, ACE2 receptor affinity, and neutralizing antibody recognition. We identified key mutations enabling escape from neutralizing antibodies at a variety of epitopes. Stabilizing mutations in the N-terminal and S2 domains of the spike protein can compensate for destabilizing mutations in the receptor binding domain, enabling the record number of mutations in Omicron. Our results provide a comprehensive account of the mutational effects in the Omicron spike protein and illustrate previously uncharacterized mechanisms of host evasion.

Structure-based design of prefusion-stabilized human metapneumovirus fusion proteins

The human metapneumovirus (hMPV) fusion (F) protein is essential for viral entry and is a key target of neutralizing antibodies and vaccine development. The prefusion conformation is thought to be the optimal vaccine antigen, but previously described prefusion F proteins expressed poorly and were not well stabilized. Here, we use structures of hMPV F to guide the design of 42 variants containing stabilizing substitutions. Through combinatorial addition of disulfide bonds, cavity-filling substitutions, and improved electrostatic interactions, we describe a prefusion-stabilized F protein (DS-CavEs2) that expresses at 15 mg/L and has a melting temperature of 71.9 °C. Crystal structures of two prefusion-stabilized hMPV F variants reveal that antigenic surfaces are largely unperturbed. Importantly, immunization of mice with DS-CavEs2 elicits significantly higher neutralizing antibody titers against hMPV A1 and B1 viruses than postfusion F. The improved properties of DS-CavEs2 will advance the development of hMPV vaccines and the isolation of therapeutic antibodies.

The degree to which the conformation of the human metapneumovirus fusion (F) protein affects immunogenicity has been debated. Here, Hsieh et al. engineer prefusion-stabilized F variants with enhanced thermostability that elicit higher neutralizing antibody titers in mice than postfusion F.

Rapid characterization of spike variants via mammalian cell surface display

The SARS-CoV-2 spike protein is a critical component of vaccines and a target for neutralizing monoclonal antibodies (nAbs). Spike is also undergoing immunogenic selection with variants that increase infectivity and partially escape convalescent plasma. Here, we describe Spike Display, a high-throughput platform to rapidly characterize glycosylated spike ectodomains across multiple coronavirus-family proteins. We assayed ∼200 variant SARS-CoV-2 spikes for their expression, ACE2 binding, and recognition by 13 nAbs. An alanine scan of all five N-terminal domain (NTD) loops highlights a public epitope in the N1, N3, and N5 loops recognized by most NTD-binding nAbs. NTD mutations in variants of concern B.1.1.7 (alpha), B.1.351 (beta), B.1.1.28 (gamma), B.1.427/B.1.429 (epsilon), and B.1.617.2 (delta) impact spike expression and escape most NTD-targeting nAbs. Finally, B.1.351 and B.1.1.28 completely escape a potent ACE2 mimic. We anticipate that Spike Display will accelerate antigen design, deep scanning mutagenesis, and antibody epitope mapping for SARS-CoV-2 and other emerging viral threats.

Stabilized coronavirus spike stem elicits a broadly protective antibody

Current coronavirus (CoV) vaccines primarily target immunodominant epitopes in the S1 subunit, which are poorly conserved and susceptible to escape mutations, thus threatening vaccine efficacy. Here, we use structure-guided protein engineering to remove the S1 subunit from the Middle East respiratory syndrome (MERS)-CoV spike (S) glycoprotein and develop stabilized stem (SS) antigens. Vaccination with MERS SS elicits cross-reactive β-CoV antibody responses and protects mice against lethal MERS-CoV challenge. High-throughput screening of antibody-secreting cells from MERS SS-immunized mice led to the discovery of a panel of cross-reactive monoclonal antibodies. Among them, antibody IgG22 binds with high affinity to both MERS-CoV and severe acute respiratory syndrome (SARS)-CoV-2 S proteins, and a combination of electron microscopy and crystal structures localizes the epitope to a conserved coiled-coil region in the S2 subunit. Passive transfer of IgG22 protects mice against both MERS-CoV and SARS-CoV-2 challenge. Collectively, these results provide a proof of principle for cross-reactive CoV antibodies and inform the development of pan-CoV vaccines and therapeutic antibodies.

Expression and characterization of SARS-CoV-2 spike proteins

The severe acute respiratory syndrome coronavirus 2 spike protein is a critical component of coronavirus disease 2019 vaccines and diagnostics and is also a therapeutic target. However, the spike protein is difficult to produce recombinantly because it is a large trimeric class I fusion membrane protein that is metastable and heavily glycosylated. We recently developed a prefusion-stabilized spike variant, termed HexaPro for six stabilizing proline substitutions, that can be expressed with a yield of >30 mg/L in ExpiCHO cells. This protocol describes an optimized workflow for expressing and biophysically characterizing rationally engineered spike proteins in Freestyle 293 and ExpiCHO cell lines. Although we focus on HexaPro, this protocol has been used to purify over a hundred different spike variants in our laboratories. We also provide guidance on expression quality control, long-term storage, and uses in enzyme-linked immunosorbent assays. The entire protocol, from transfection to biophysical characterization, can be completed in 7 d by researchers with basic tissue cell culture and protein purification expertise.

Prevalent, protective, and convergent IgG recognition of SARS-CoV-2 non-RBD spike epitopes

The molecular composition and binding epitopes of the immunoglobulin G (IgG) antibodies that circulate in blood plasma after severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection are unknown. Proteomic deconvolution of the IgG repertoire to the spike glycoprotein in convalescent subjects revealed that the response is directed predominantly (>80%) against epitopes residing outside the receptor binding domain (RBD). In one subject, just four IgG lineages accounted for 93.5% of the response, including an amino (N)-terminal domain (NTD)-directed antibody that was protective against lethal viral challenge. Genetic, structural, and functional characterization of a multidonor class of "public" antibodies revealed an NTD epitope that is recurrently mutated among emerging SARS-CoV-2 variants of concern. These data show that "public" NTD-directed and other non-RBD plasma antibodies are prevalent and have implications for SARS-CoV-2 protection and antibody escape.

Molecular Architecture of Early Dissemination and Massive Second Wave of the SARS-CoV-2 Virus in a Major Metropolitan Area

We sequenced the genomes of 5,085 severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) strains causing two coronavirus disease 2019 (COVID-19) disease waves in metropolitan Houston, TX, an ethnically diverse region with 7 million residents. The genomes were from viruses recovered in the earliest recognized phase of the pandemic in Houston and from viruses recovered in an ongoing massive second wave of infections. The virus was originally introduced into Houston many times independently. Virtually all strains in the second wave have a Gly614 amino acid replacement in the spike protein, a polymorphism that has been linked to increased transmission and infectivity. Patients infected with the Gly614 variant strains had significantly higher virus loads in the nasopharynx on initial diagnosis. We found little evidence of a significant relationship between virus genotype and altered virulence, stressing the linkage between disease severity, underlying medical conditions, and host genetics. Some regions of the spike protein-the primary target of global vaccine efforts-are replete with amino acid replacements, perhaps indicating the action of selection. We exploited the genomic data to generate defined single amino acid replacements in the receptor binding domain of spike protein that, importantly, produced decreased recognition by the neutralizing monoclonal antibody CR3022. Our report represents the first analysis of the molecular architecture of SARS-CoV-2 in two infection waves in a major metropolitan region. The findings will help us to understand the origin, composition, and trajectory of future infection waves and the potential effect of the host immune response and therapeutic maneuvers on SARS-CoV-2 evolution.IMPORTANCE There is concern about second and subsequent waves of COVID-19 caused by the SARS-CoV-2 coronavirus occurring in communities globally that had an initial disease wave. Metropolitan Houston, TX, with a population of 7 million, is experiencing a massive second disease wave that began in late May 2020. To understand SARS-CoV-2 molecular population genomic architecture and evolution and the relationship between virus genotypes and patient features, we sequenced the genomes of 5,085 SARS-CoV-2 strains from these two waves. Our report provides the first molecular characterization of SARS-CoV-2 strains causing two distinct COVID-19 disease waves.

Molecular Architecture of Early Dissemination and Massive Second Wave of the SARS-CoV-2 Virus in a Major Metropolitan Area

We sequenced the genomes of 5,085 SARS-CoV-2 strains causing two COVID-19 disease waves in metropolitan Houston, Texas, an ethnically diverse region with seven million residents. The genomes were from viruses recovered in the earliest recognized phase of the pandemic in Houston, and an ongoing massive second wave of infections. The virus was originally introduced into Houston many times independently. Virtually all strains in the second wave have a Gly614 amino acid replacement in the spike protein, a polymorphism that has been linked to increased transmission and infectivity. Patients infected with the Gly614 variant strains had significantly higher virus loads in the nasopharynx on initial diagnosis. We found little evidence of a significant relationship between virus genotypes and altered virulence, stressing the linkage between disease severity, underlying medical conditions, and host genetics. Some regions of the spike protein - the primary target of global vaccine efforts - are replete with amino acid replacements, perhaps indicating the action of selection. We exploited the genomic data to generate defined single amino acid replacements in the receptor binding domain of spike protein that, importantly, produced decreased recognition by the neutralizing monoclonal antibody CR30022. Our study is the first analysis of the molecular architecture of SARS-CoV-2 in two infection waves in a major metropolitan region. The findings will help us to understand the origin, composition, and trajectory of future infection waves, and the potential effect of the host immune response and therapeutic maneuvers on SARS-CoV-2 evolution.

Structure-based design of prefusion-stabilized SARS-CoV-2 spikes

The coronavirus disease 2019 (COVID-19) pandemic has led to accelerated efforts to develop therapeutics and vaccines. A key target of these efforts is the spike (S) protein, which is metastable and difficult to produce recombinantly. We characterized 100 structure-guided spike designs and identified 26 individual substitutions that increased protein yields and stability. Testing combinations of beneficial substitutions resulted in the identification of HexaPro, a variant with six beneficial proline substitutions exhibiting higher expression than its parental construct (by a factor of 10) as well as the ability to withstand heat stress, storage at room temperature, and three freeze-thaw cycles. A cryo-electron microscopy structure of HexaPro at a resolution of 3.2 angstroms confirmed that it retains the prefusion spike conformation. High-yield production of a stabilized prefusion spike protein will accelerate the development of vaccines and serological diagnostics for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2).

Structure-based design of prefusion-stabilized SARS-CoV-2 spikes

The coronavirus disease 2019 (COVID-19) pandemic has led to accelerated efforts to develop therapeutics and vaccines. A key target of these efforts is the spike (S) protein, which is metastable and difficult to produce recombinantly. We characterized 100 structure-guided spike designs and identified 26 individual substitutions that increased protein yields and stability. Testing combinations of beneficial substitutions resulted in the identification of HexaPro, a variant with six beneficial proline substitutions exhibiting higher expression than its parental construct (by a factor of 10) as well as the ability to withstand heat stress, storage at room temperature, and three freeze-thaw cycles. A cryo-electron microscopy structure of HexaPro at a resolution of 3.2 angstroms confirmed that it retains the prefusion spike conformation. High-yield production of a stabilized prefusion spike protein will accelerate the development of vaccines and serological diagnostics for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2).

Structure-based Design of Prefusion-stabilized SARS-CoV-2 Spikes

The COVID-19 pandemic caused by the novel coronavirus SARS-CoV-2 has led to accelerated efforts to develop therapeutics, diagnostics, and vaccines to mitigate this public health emergency. A key target of these efforts is the spike (S) protein, a large trimeric class I fusion protein that is metastable and difficult to produce recombinantly in large quantities. Here, we designed and expressed over 100 structure-guided spike variants based upon a previously determined cryo-EM structure of the prefusion SARS-CoV-2 spike. Biochemical, biophysical and structural characterization of these variants identified numerous individual substitutions that increased protein yields and stability. The best variant, HexaPro, has six beneficial proline substitutions leading to ~10-fold higher expression than its parental construct and is able to withstand heat stress, storage at room temperature, and multiple freeze-thaws. A 3.2 Å-resolution cryo-EM structure of HexaPro confirmed that it retains the prefusion spike conformation. High-yield production of a stabilized prefusion spike protein will accelerate the development of vaccines and serological diagnostics for SARS-CoV-2.

Frequency-comb spectroscopy on pure quantum states of a single molecular ion

Spectroscopy is a powerful tool for studying molecules and is commonly performed on large thermal molecular ensembles that are perturbed by motional shifts and interactions with the environment and one another, resulting in convoluted spectra and limited resolution. Here, we use quantum-logic techniques to prepare a trapped molecular ion in a single quantum state, drive terahertz rotational transitions with an optical frequency comb, and read out the final state nondestructively, leaving the molecule ready for further manipulation. We can resolve rotational transitions to 11 significant digits and derive the rotational constant of 40CaH+ to be B R = 142 501 777.9(1.7) kilohertz. Our approach is suited for a wide range of molecular ions, including polyatomics and species relevant for tests of fundamental physics, chemistry, and astrophysics.

^{27}Al^{+} Quantum-Logic Clock with a Systematic Uncertainty below 10^{-18}

We describe an optical atomic clock based on quantum-logic spectroscopy of the ^{1}S_{0}↔^{3}P_{0} transition in ^{27}Al^{+} with a systematic uncertainty of 9.4×10^{-19} and a frequency stability of 1.2×10^{-15}/sqrt[τ]. A ^{25}Mg^{+} ion is simultaneously trapped with the ^{27}Al^{+} ion and used for sympathetic cooling and state readout. Improvements in a new trap have led to reduced secular motion heating, compared to previous ^{27}Al^{+} clocks, enabling clock operation with ion secular motion near the three-dimensional ground state. Operating the clock with a lower trap drive frequency has reduced excess micromotion compared to previous ^{27}Al^{+} clocks. Both of these improvements have led to a reduced time-dilation shift uncertainty. Other systematic uncertainties including those due to blackbody radiation and the second-order Zeeman effect have also been reduced.

Synthesis of the extended phenacene molecules, [10]phenacene and [11]phenacene, and their performance in a field-effect transistor

The [10]phenacene and [11]phenacene molecules have been synthesized using a simple repetition of Wittig reactions followed by photocyclization. Sufficient amounts of [10]phenacene and [11]phenacene were obtained, and thin-film FETs using these molecules have been fabricated with SiO₂ and ionic liquid gate dielectrics. These FETs operated in p-channel. The averaged measurements of field-effect mobility, <μ>, were 3.1(7) × 10⁻² and 1.11(4) × 10⁻¹ cm² V⁻¹ s⁻¹, respectively, for [10]phenacene and [11]phenacene thin-film FETs with SiO₂ gate dielectrics. Furthermore, [10]phenacene and [11]phenacene thin-film electric-double-layer (EDL) FETs with ionic liquid showed low-voltage p-channel FET properties, with <μ> values of 3(1) and 1(1) cm² V⁻¹ s⁻¹, respectively. This study also discusses the future utility of the extremely extended π-network molecules [10]phenacene and [11]phenacene as the active layer of FET devices, based on the experimental results obtained.

Sympathetic Ground State Cooling and Time-Dilation Shifts in an ^{27}Al^{+} Optical Clock

We report on Raman sideband cooling of ^{25}Mg^{+} to sympathetically cool the secular modes of motion in a ^{25}Mg^{+}-^{27}Al^{+} two-ion pair to near the three-dimensional (3D) ground state. The evolution of the Fock-state distribution during the cooling process is studied using a rate-equation simulation, and various heating sources that limit the efficiency of 3D sideband cooling in our system are discussed. We characterize the residual energy and heating rates of all of the secular modes of motion and estimate a secular motion time-dilation shift of -(1.9±0.1)×10^{-18} for an ^{27}Al^{+} clock at a typical clock probe duration of 150 ms. This is a 50-fold reduction in the secular motion time-dilation shift uncertainty in comparison with previous ^{27}Al^{+} clocks.

Induction of c-Cbl contributes to anti-cancer effects of HDAC inhibitor in lung cancer

Here we found loss of c-Cbl, an E3 ligase, expression in non-small cell lung cancer (NSCLC) compared with its adjacent normal tissue in patient specimens. HDAC inhibition by WJ or knockdown of HDAC 1, HDAC2, HDAC3 or HDAC6 all induced c-Cbl. Ectopic expression of c-Cbl induced decreased EGFR, inhibited growth in NSCLC cells. Knockdown of EGFR inhibited NSCLC growth. Mutation of EGFR at Y1045 decreased WJ-induced growth inhibition as well as in vivo anti-cancer effect and EGFR degradation mediated by WJ. Time-lapse confocal analysis showed co-localization of c-Cbl and EGFR after WJ treatment. Furthermore, WJ inhibited lung tumor growth through c-Cbl induction in orthotopic and tail vein injected models. C-Cbl up-regulation induced by HDACi is a potential strategy for NSCLC treatment.

Abstract LB-250: Induction of c-Cbl is a novel mechanism for the anti-cancer effect of HDAC inhibitor in lung cancer

Here we found loss of c-Cbl, an E3 ligase, expression in Non-small cell lung cancer (NSCLC) compared with its adjacent normal tissue in patient specimens. HDAC inhibition by WJ or knockdown of HDAC 1, HDAC2, HDAC3 or HDAC6 all induced c-Cbl. Ectopic expression of c-Cbl induced decreased EGFR, inhibited growth in NSCLC cells. Knockdown of EGFR inhibited NSCLC growth. Mutation of EGFR at Y1045 decreased WJ-induced growth inhibition as well as in vivo anti-cancer effect and EGFR degradation mediated by WJ. Time-lapse confocal analysis showed co-localization of c-Cbl and EGFR after WJ treatment. Furthermore, WJ inhibited lung tumor growth through c-Cbl induction in orthotopic and tail vein injected models. C-Cbl up-regulation induced by HDACi is a potential strategy for NSCLC treatment.

Citation Format: Chen Ching-Chow, Tzu-Tang Wei, Yu-Chin Lin, Pei-Hua Lin, Jin-Yuan Shih, Chia-Wei Chou. Induction of c-Cbl is a novel mechanism for the anti-cancer effect of HDAC inhibitor in lung cancer. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr LB-250. doi:10.1158/1538-7445.AM2015-LB-250

A MedRadio-band low-energy-per-bit 4-Mbps CMOS OOK receiver for implantable medical devices

A 4-Mbps 400-MHz On-Off Keying (OOK) receiver implemented in 0.18-um CMOS technology for implantable epilepsy sense-and-stimulation devices is presented. The proposed receiver is composed of a new current-mode full-wave envelope detector and differential cascaded gain amplifiers which is operated at MedRadio band. The fabricated receiver has power consumption of 0.27 mW and energy consumption of 0.07 nJ per bit at 4-Mbps. The sensitivity of receiver is -45.67 dBm.

Trapped-ion state detection through coherent motion

We demonstrate a general method for state detection of trapped ions that can be applied to a large class of atomic and molecular species. We couple a spectroscopy ion (27Al+) to a control ion (25Mg+) in the same trap and perform state detection through off-resonant laser excitation of the spectroscopy ion that induces coherent motion. The motional amplitude, dependent on the spectroscopy ion state, is measured either by time-resolved photon counting or by resolved sideband excitations on the control ion. The first method provides a simplified way to distinguish clock states in 27Al+, which avoids ground-state cooling and sideband transitions. The second method reduces spontaneous emission and optical pumping on the spectroscopy ion, which we demonstrate by nondestructively distinguishing Zeeman sublevels in the (1)S0 ground state of 27Al+.

Quantum coherence between two atoms beyond Q=10(15)

We place two atoms in quantum superposition states and observe coherent phase evolution for 3.4×10(15) cycles. Correlation signals from the two atoms yield information about their relative phase even after the probe radiation has decohered. This technique allowed a frequency comparison of two (27)Al(+) ions with fractional uncertainty 3.7(-0.8)(+1.0)×10(-16)/√[τ/s]. Two measures of the Q factor are reported: The Q factor derived from quantum coherence is 3.4(-1.1)(+2.4)×10(16), and the spectroscopic Q factor for a Ramsey time of 3 s is 6.7×10(15). We demonstrate a method to detect the individual quantum states of two Al(+) ions in a Mg(+)-Al(+)-Al(+) linear ion chain without spatially resolving the ions.

HDAC inhibition decreases the expression of EGFR in colorectal cancer cells

Epidermal growth factor receptor (EGFR), a receptor tyrosine kinase which promotes cell proliferation and survival, is abnormally overexpressed in numerous tumors of epithelial origin, including colorectal cancer (CRC). EGFR monoclonal antibodies have been shown to increase the median survival and are approved for the treatment of colorectal cancer. Histone deacetylases (HDACs), frequently overexpressed in colorectal cancer and several malignancies, are another attractive targets for cancer therapy. Several inhibitors of HDACs (HDACi) are developed and exhibit powerful antitumor abilities. In this study, human colorectal cancer cells treated with HDACi exhibited reduced EGFR expression, thereby disturbed EGF-induced ERK and Akt phosphorylation. HDACi also decreased the expression of SGLT1, an active glucose transporter found to be stabilized by EGFR, and suppressed the glucose uptake of cancer cells. HDACi suppressed the transcription of EGFR and class I HDACs were proved to be involved in this event. Chromatin immunoprecipitation analysis showed that HDACi caused the dissociation of SP1, HDAC3 and CBP from EGFR promoter. Our data suggested that HDACi could serve as a single agent to block both EGFR and HDAC, and may bring more benefits to the development of CRC therapy.

Association between sensorimotor function and forward reach in patients with diabetes

Deterioration in the function of the sensorimotor system is often seen in patients with diabetes and could be related to balance impairments. The purpose of this study was to determine the association between sensorimotor function and forward reach ability in patients with diabetes. Thirty-one patients with Type 2 diabetes went through a monofilament test of plantar touch-pressure threshold, an ankle joint reposition test for joint position sense, and a series of strength tests of the lower leg. These patients also performed the forward reach test in standing to measure the reach distance and displacement of the center of mass (COM), using a motion analysis system. Correlational and regressional analyses were conducted to determine the association between sensorimotor and balance parameters. It was found that greater reach distance and COM displacement were significantly correlated with lower plantar touch-pressure threshold and greater plantarflexion strength. Regression analysis showed that after controlling the variance in the subject characteristics, plantar touch-pressure threshold was a significant predictor for reach distance and COM displacement, while plantarflexion strength was also a significant predictor for COM displacement. These findings highlight the importance of the assessment of plantar sensitivity and the need for detailed balance or fall risk assessment for patients with impaired plantar insensitivity.

Frequency comparison of two high-accuracy Al+ optical clocks

We have constructed an optical clock with a fractional frequency inaccuracy of 8.6x10{-18}, based on quantum logic spectroscopy of an Al+ ion. A simultaneously trapped Mg+ ion serves to sympathetically laser cool the Al+ ion and detect its quantum state. The frequency of the {1}S{0}<-->{3}P{0} clock transition is compared to that of a previously constructed Al+ optical clock with a statistical measurement uncertainty of 7.0x10{-18}. The two clocks exhibit a relative stability of 2.8x10{-15}tau{-1/2}, and a fractional frequency difference of -1.8x10{-17}, consistent with the accuracy limit of the older clock.

Loss of IKKbeta activity increases p53 stability and p21 expression leading to cell cycle arrest and apoptosis

Elevated levels of NF-kappaB are frequently detected in many inflammatory diseases and cancers. Blocking the IKK-NF-kappaB pathway has been seen as a promising approach for new therapies. By employing the dominant-negative mutant of IKKbeta, our data revealed that loss of IKKbeta activity reduces not only the proliferation and invasion of lung adenocarcinoma A549 cells in vitro but also the tumour formation, metastasis and angiogenesis in mouse xenograft model. Treatment of IKKbeta inhibitors (CYL-19s and CYL-26z) leads to the arrest of cell cycle progression at G1 and G2/M, followed by apoptosis. IKKbeta inhibitors can increase the protein stability, nuclear accumulation and promoter-binding activity of p53, leading to the p21 gene transcription. Furthermore, knockdown of IKKbeta by siRNA increased the stability and expression of p53 and p21 promoter activity. In addition, IKKbeta inhibitor-induced p53 and p21 expressions were augmented in the presence of IKKbeta siRNA. Correlation between p53 acetylation and its protein stabilization was also seen after treatment with IKKbeta inhibitors. These results suggest that loss of IKKbeta activation is important for the enhancement of p53 stability, leading to p21 expression and cell cycle arrest and apoptosis of tumour cells.

HDAC inhibition upregulates the expression of angiostatic ADAMTS1

HDAC inhibitors are promising anticancer agents that induce cell cycle arrest and apoptosis. However, the role of HDACs in cancer progression, such as angiogenesis and metastasis, remains largely unexplored. Among various HDAC inhibitors, we demonstrate that TSA and SAHA upregulated the expression of angiostatic ADAMTS1 in A549 cells. HDAC6 inhibitor tubacin, and knockdown of HDAC6, also lead to ADAMTS1 upregulation. By reporter, DAPA, and ChIP assays, the proximal GC boxes were demonstrated to be essential for ADAMTS1 induction. Decreased binding of SP1 and HDAC6 to the ADAMTS1 promoter after TSA treatment was also seen. These data suggest the involvement of HDAC6 and SP1 in the HDACi-induced expression of angiostatic ADAMTS1.

Proteasome inhibitors enhance TRAIL-induced apoptosis through the intronic regulation of DR5: involvement of NF-kappa B and reactive oxygen species-mediated p53 activation

Manipulation of TRAIL receptor 2 (DR5) pathway is a promising therapeutic strategy to overcome TRAIL-resistant lung cancer cells. Preclinical studies have shown that proteasome inhibitors enhance TRAIL-induced apoptosis in lung cancer cells, but the underlying mechanism has not been fully elucidated. In this study, we demonstrated the enhancement of TRAIL-mediated apoptosis in human alveolar epithelial cells by proteasome inhibitors that up-regulate DR5 expression. This effect was blocked by DR5-neutralizing Ab. Using reporter assay, we demonstrated that the p53 and NF-kappaB elements on the DR5 first intron region were involved in proteasome inhibitor-induced DR5 expression. Both p53 small interfering RNA and NF-kappaB inhibitor suppressed DR5 expression, strengthening the significance of p53 and NF-kappaB in DR5 transcription. The protein stability, Ser(392) phosphorylation and Lys(373)/Lys(382) acetylation of p53 were enhanced by MG132. In addition to p53, IkappaBalpha degradation and NF-kappaB translocation was also observed. Moreover, the binding of p53 and p65 to the first intron of DR5 was demonstrated by DNA affinity protein-binding and chromatin immunoprecipitation assays. Intracellular reactive oxygen species (ROS) generation after MG132 treatment contributed to p53, but not p65 nuclear translocation and DNA-binding activity. ROS scavenger dramatically inhibited the apoptosis induced by proteasome inhibitors plus TRAIL. The p53-null H1299 cells were resistant to proteasome inhibitor-induced DR5 up-regulation and enhancement of TRAIL-induced apoptosis. These findings reveal that proteasome inhibitor-mediated NF-kappaB and ROS-dependent p53 activation are contributed to intronic regulation of DR5 transcription, and resulted in the subsequent enhancement of TRAIL-induced apoptosis in human lung cancer cells.

Analysis of oligonucleotides by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry

MALDI-MS is one of the most useful techniques available for determining biomolecule mass. It offers high mass accuracy, good sensitivity, simplicity, and speed. Because singly charged ions of oligonucleotides are typically observed, MALDI-MS spectra are easy to interpret. This unit presents protocols for sample preparation and purification, matrix preparation, and matrix/analyte sample preparation. It provides an introduction to the instrumentation and its calibration, and a discussion of some of the useful applications of MALDI-MS analysis in the study of oligonucleotides. This technique is typically used for 120-mer or smaller oligonucleotides.

Frequency ratio of Al+ and Hg+ single-ion optical clocks; metrology at the 17th decimal place

Time has always had a special status in physics because of its fundamental role in specifying the regularities of nature and because of the extraordinary precision with which it can be measured. This precision enables tests of fundamental physics and cosmology, as well as practical applications such as satellite navigation. Recently, a regime of operation for atomic clocks based on optical transitions has become possible, promising even higher performance. We report the frequency ratio of two optical atomic clocks with a fractional uncertainty of 5.2 x 10(-17). The ratio of aluminum and mercury single-ion optical clock frequencies nuAl+/nuHg+ is 1.052871833148990438(55), where the uncertainty comprises a statistical measurement uncertainty of 4.3 x 10(-17), and systematic uncertainties of 1.9 x 10(-17) and 2.3 x 10(-17) in the mercury and aluminum frequency standards, respectively. Repeated measurements during the past year yield a preliminary constraint on the temporal variation of the fine-structure constant alpha of alpha/alpha = (-1.6+/-2.3) x 10(-17)/year.

Heralded entanglement between atomic ensembles: preparation, decoherence, and scaling

Heralded entanglement between collective excitations in two atomic ensembles is probabilistically generated, stored, and converted to single-photon fields. By way of the concurrence, quantitative characterizations are reported for the scaling behavior of entanglement with excitation probability and for the temporal dynamics of various correlations resulting in the decay of entanglement. A lower bound of the concurrence for the collective atomic state of 0.9+/-0.3 is inferred. The decay of entanglement as a function of storage time is also observed, and related to the local dynamics.

Direct measurement of decoherence for entanglement between a photon and stored atomic excitation

Violations of a Bell inequality are reported for an experiment where one of two entangled qubits is stored in a collective atomic memory for a user-defined time delay. The atomic qubit is found to preserve the violation of a Bell inequality for storage times up to 21 micros, 700 times longer than the duration of the excitation pulse that creates the entanglement. To address the question of the security of entanglement-based cryptography implemented with this system, an investigation of the Bell violation as a function of the cross correlation between the generated nonclassical fields is reported, with saturation of the violation close to the maximum value allowed by quantum mechanics.

Three-dimensional analysis for radio-frequency ablation of liver tumor with blood perfusion effect

Increase of temperature above 50 approximately 60 degrees C for few minutes by the emitted radio-frequency (RF) energy has been shown to be able to denaturate the intracellular proteins and destruct membranes of tumor cells. To improve the efficacy of this thermal therapy, it is important to investigate factors that may affect the RF heating characteristics for the hepatocellular carcinoma and metastatic liver tumors. In order to make sure the applied RF energy is adequate to ablate the target tumor, a 3D thermoelectric analysis for the system consisting of liver, liver arteries and 4 mm diameter tumor is conducted. The effect of blood perfusion is addressed in this study.

Measurement-induced entanglement for excitation stored in remote atomic ensembles

A critical requirement for diverse applications in quantum information science is the capability to disseminate quantum resources over complex quantum networks. For example, the coherent distribution of entangled quantum states together with quantum memory (for storing the states) can enable scalable architectures for quantum computation, communication and metrology. Here we report observations of entanglement between two atomic ensembles located in distinct, spatially separated set-ups. Quantum interference in the detection of a photon emitted by one of the samples projects the otherwise independent ensembles into an entangled state with one joint excitation stored remotely in 10(5) atoms at each site. After a programmable delay, we confirm entanglement by mapping the state of the atoms to optical fields and measuring mutual coherences and photon statistics for these fields. We thereby determine a quantitative lower bound for the entanglement of the joint state of the ensembles. Our observations represent significant progress in the ability to distribute and store entangled quantum states.

Temporal dynamics of photon pairs generated by an atomic ensemble

The time dependence of nonclassical correlations is investigated for two fields (1,2) generated by an ensemble of cold cesium atoms via the protocol of Duan et al. [Nature (London) 414, 413 (2001)]]. The correlation function R(t1,t2) for the ratio of cross to autocorrelations for the (1,2) fields at times (t1,t2) is found to have a maximum value R(max=292+/-57, which significantly violates the Cauchy-Schwarz inequality R< or =1 for classical fields. Decoherence of quantum correlations is observed over taud approximately 175 ns, and is described by our model, as is a new scheme to mitigate this effect.

Single-photon generation from stored excitation in an atomic ensemble

Single photons are generated from an ensemble of cold Cs atoms via the protocol of Duan et al. [Nature (London), ()]]. Conditioned upon an initial detection from field 1 at 852 nm, a photon in field 2 at 894 nm is produced in a controlled fashion from excitation stored within the atomic ensemble. The single-quantum character of field 2 is demonstrated by the violation of a Cauchy-Schwarz inequality, namely w(1(2),1(2)|1(1))=0.24+/-0.05 not > or = 1, where w(1(2),1(2)|1(1)) describes the detection of two events (1(2),1(2)) conditioned upon an initial detection 1(1), with w-->0 for single photons.

Generation of nonclassical photon pairs for scalable quantum communication with atomic ensembles

Quantum information science attempts to exploit capabilities from the quantum realm to accomplish tasks that are otherwise impossible in the classical domain. Although sufficient conditions have been formulated for the physical resources required to achieve quantum computation and communication, there is a growing understanding of the power of quantum measurement combined with the conditional evolution of quantum states for accomplishing diverse tasks in quantum information science. For example, a protocol has recently been developed for the realization of scalable long-distance quantum communication and the distribution of entanglement over quantum networks. Here we report the first enabling step in the realization of this protocol, namely the observation of quantum correlations for photon pairs generated in the collective emission from an atomic ensemble. The nonclassical character of the fields is demonstrated by the violation of an inequality involving their normalized correlation functions. Compared to previous investigations of non-classical correlations for photon pairs produced in atomic cascades and in parametric down-conversion, our experiment is distinct in that the correlated photons are separated by a programmable time interval (of about 400 nanoseconds in our initial experiments).

Usefulness of the suspended microbubble sign in differentiating empyemic and nonempyemic hydropneumothorax

OBJECTIVE

The suspended microbubble sign is defined as the image seen on ultrasonography consisting of a pleural effusion strewn with numerous hyperechoic pinpoints and more or less linear shadows that move synchronously with respiration. In this study, we intended to evaluate the clinical usefulness of the suspended microbubble sign in differentiating empyemic and nonempyemic hydropneumothorax.

METHODS

This series consisted of 8 patients with empyemic hydropneumothorax and 23 patients with nonempyemic hydropneumothorax. The finding of the presence of the suspended microbubble signs on ultrasonography was recorded. To further elucidate the generation of the suspended microbubble sign, the interaction between air and pleural fluid of different types was investigated in vitro.

RESULTS

The suspended microbubble sign was shown on ultrasonography in all 8 patients with empyemic hydropneumothorax but was absent in the 23 patients with nonempyemic hydropneumothorax. These findings were supported by the observation that the pus seemed to mix with and trap the air more easily than did the nonpurulent pleural fluid, as shown in vitro. In this selected population, the sensitivity and specificity of the suspended microbubble sign in aiding a diagnosis of empyemic hydropneumothorax were both 100%.

CONCLUSION

The suspended microbubble sign shown on ultrasonography might be of considerable value in differentiating empyemic and nonempyemic hydropneumothorax.

A novel endo-beta-galactosidase from Clostridium perfringens that liberates the disaccharide GlcNAcalpha 1-->Gal from glycans specifically expressed in the gastric gland mucous cell-type mucin

We found that commercially available sialidases prepared from Clostridium perfringens ATCC10543 were contaminated with an endoglycosidase capable of releasing the disaccharide GlcNAcalpha1-->4Gal from glycans expressed in the gastric gland mucous cell-type mucin. We have isolated this enzyme in electrophoretically homogeneous form from the culture supernatant of this organism by ammonium sulfate precipitation followed by affinity chromatography using a Sephacryl S-200 HR column. The enzyme was specifically retained by and eluted from the column with methyl-alpha-Glc. By NMR spectroscopy, the structure of the disaccharide released from porcine gastric mucin by this enzyme was established to be GlcNAcalpha1-->4Gal. The specificity of this enzyme as an endo-beta-galactosidase was established by analyzing the liberation of GlcNAcalpha1-->4Gal from GlcNAcalpha1-->4Galbeta1-->4GlcNAcbeta1-->6(GlcNAcalpha1--> 4Galbeta1-->3)GalNAc-ol by mass spectrometry. Because this novel endo-beta-galactosidase specifically releases the GlcNAcalpha1-->4Gal moiety from porcine gastric mucin, we propose to call this enzyme a GlcNAcalpha1-->4Gal-releasing endo-beta-galactosidase (Endo-beta-Gal(GnGa)). Endo-beta-Gal(GnGa) was found to remove the GlcNAcalpha1-->4Gal epitope expressed in gastric adenocarcinoma AGS cells transfected with alpha1,4-N-acetylglucosaminyltransferase cDNA. Endo-beta-Gal(GnGa) should become useful for studying the structure and function of glycoconjugates containing the terminal GlcNAcalpha1-->4Gal epitope.

Anterior pituitary failure (panhypopituitarism) with balanced chromosome translocation 46,XY,t(11;22)(q24;q13)

Hypopituitarism is the clinical syndrome that results from failure of the anterior pituitary gland to produce its hormones. Hypopituitarism can result from: (1) intrinsic or primary pituitary disease; (2) intrinsic hypothalamic or secondary pituitary disease; or (3) extrinsic extrasellar or parasellar disease. The etiologies of primary hypopituitarism are miscellaneous. The dominant clinical picture of hypopituitarism in the adult is that of hypogonadism. Reports have associated hypopituitarism with anti-pituitary-antibodies, hereditary syndrome and chromosome defects, but hypopituitarism has rarely been associated with balanced chromosome translocation (11;22)(q24;q13). Here, we describe a case of anterior pituitary failure with balanced chromosome translocation. A 19-year-old Chinese teenager presented with failure of pubertal development and sexual infantilism. On examination, the patient had the classic appearance of hypogonadism. Endocrine studies and three combined pituitary function tests revealed panhypopituitarism. A chromosomal study revealed 46,XY,t(11;22)(q24;q13), a balanced translocation between 11q24 and 22q13. Chest films showed delayed fusion of bilateral humeral head epiphyses and bilateral acromions. Scrotal sonography revealed testes were small bilaterally. Magnetic resonance imaging (MRI) of the sella revealed pituitary dwarfism. The patient received 19 months replacement therapy, including steroids (prednisolone 5 mg each day), L-thyroxine (Eltroxin 100 ug each day), and testosterone enanthate 250 mg every two weeks. His height increased 4 cm with secondary sexual characteristics developed, and muscle power increased.

Diagnosis of pulmonary alveolar proteinosis: usefulness of papanicolaou-stained smears of bronchoalveolar lavage fluid

BACKGROUND

The globules (stained green, orange, or orange in the center coated with a green rim) seen in Papanicolaou-stained smears of bronchoalveolar lavage fluid are suggested to be characteristic of pulmonary alveolar proteinosis (PAP).

OBJECTIVE

To evaluate the usefulness of Papanicolaou-stained smears of bronchoalveolar lavage fluid in aiding a diagnosis of PAP.

METHODS

Papanicolaou-stained smears of bronchoalveolar lavage fluid obtained from 7 patients (5 idiopathic, 2 secondary) with PAP were evaluated. To serve as controls, the smears of 11 normal subjects and 128 patients with other pulmonary disorders were also examined. The findings on the presence and number of globules were recorded. To differentiate PAP from other pulmonary disorders, the highest globule value obtained from the control group was chosen as the cutoff point.

RESULTS

The characteristic globules were not found in normal subjects and only found in 6 of 128 patients with other pulmonary disorders. Their clinical diagnoses were Sjögren syndrome in 2 cases; polymyositis, idiopathic pulmonary fibrosis, asbestosis, and hypersensitivity pneumonitis in 1 case each. The numbers of globules in these 6 patients were 1, 3, 17, 7, 3, and 2. In contrast, more than 100 globules were found in all patients with PAP. The number of globules was highly sensitive and specific in aiding a diagnosis of PAP when the cutoff value was set at 18.

CONCLUSION

The globules seen in Papanicolaou-stained smears of bronchoalveolar lavage fluid may be valuable in aiding a diagnosis of PAP, especially when the number of globules is more than 18.

Down's syndrome with mucosa-associated lymphoid tissue, thyroid lymphoma and cerebral infarction

Primary lymphoma of the thyroid gland is rare. The histopathology of most low-grade thyroid lymphomas is of a mucosa-associated lymphoid tissue (MALT) type. A typical feature of this type of lymphoma is a close lymphocyte-epithelium interaction. It tends to appear in patients with a history of autoimmune disease or chronic inflammatory disorders. A clinical picture of hypothyroidism may be present. Hyperthyroidism associated with thyroid lymphoma is also rare. Thyroid lymphoma could be misdiagnosed as lymphocytic thyroiditis or small cell anaplastic carcinoma. It is rarely reported in patients with Down's syndrome. In this report, we describe a Down's syndrome patient with MALT thyroid lymphoma and cerebral infarction. The patient, a 42-year-old man, presented with chest discomfort and bilateral leg weakness of one week's duration. Physical examination of his neck showed a right-sided mass lesion. Neurologic examination revealed decreased muscle power and hyperreflexia in both lower legs. Babinski's sign was present bilaterally. Endocrinologic studies showed subclinical hypothyroidism. A thoracolumbar radiograph showed disc space narrowing. Thyroid sonography revealed a hypoechoic mass lesion in the right lobe of the thyroid gland. Fine needle aspiration cytology of the neck mass demonstrated a large amount of lymphocyte infiltration. An I131 thyroid scan and 24-hour uptake revealed the possibility of thyroid malignancy at the upper poles of both thyroid lobes. Computerized tomography of the brain revealed a lacunar infarct in the posterior aspect of the left putamen. Magnetic resonance imaging of the lumbar spine revealed a healed L4 compression fracture with L4-5 retrolithesis. The patient later underwent a right total thyroidectomy. The pathologic finding showed MALT lymphoma. The patient received steroid suppression therapy, and after nine months of treatment and follow-up, he developed clinical hypothyroidism. Neither local tumor recurrence nor distant metastasis was found.

Non-insulin-dependent diabetes mellitus with type I multiple symmetrical lipomatosis: a case report

Type I multiple symmetrical lipomatosis (MSL; Madelung's disease) is characterized by lipomas in the nape of the neck and the supraclavicular and deltoid regions, resulting in a bull-necked appearance (Madelung's collar). It is most common in alcoholic men between 35 and 50 years of age. Type I MSL has been reportedly associated with hyperinsulinemia, but its association with diabetes mellitus is rarely discussed. We describe a case of non-insulin-dependent diabetes mellitus (NIDDM) associated with type I MSL. A 47-year-old alcoholic man presented with a seven-year history of hyperglycemia and progressive neck swelling with dysphagia for one year. Physical examination showed diffuse and symmetrical swelling of the bilateral posterior aspects of the neck. Biochemistry profiles revealed elevated concentrations of fasting serum glucose (276 +/- 16 mg/dl), triglycerides (358 +/- 79 mg/dl) and total cholesterol (323 +/- 28 mg/dl). Endocrinologic studies showed normal thyroid function. Neck sonography revealed diffuse thickening and swelling of the fatty structures of both sides of the neck. Normal sonography showed no fatty deposition in the liver. Maxillary and neck computerized tomography revealed diffuse fat accumulation in the submental and posterior neck regions, with no extension to the superior mediastinum. Fine needle aspiration cytology of the neck masses showed only fat cells. The patient received an oral hypoglycemic agent (glibenclamide 5 mg bid) for blood glucose control and lovastatin (20 mg before bed-time) for hyperlipidemia, and ceased drinking alcohol. The neck swelling resolved markedly after 15 months of medical treatment. This suggests that, in addition to the cessation of alcohol consumption, the reduction of blood glucose and lipid concentrations by medication may also assist in resolving the accumulated fat of type I MSL in patients with NIDDM.

Primary hyperparathyroidism with cardiac abnormalities: a case report

Primary hyperparathyroidism, characterized by hypersecretion of parathyroid hormone (PTH) leading to hypercalcemia and relative hypophosphatemia, is quite common in the elderly. Most patients with primary hyperparathyroidism have only mild hypercalcemia and are symptomless. But others experience various other organ diseases. Primary hyperparathyroidism is also associated with cardiovascular abnormalities, including QT interval shortening, heart block, cardiac arrhythmias, hypertension, myocardial hypertrophy, myocardial calcification and, though rarely, with valvular heart disease. We described a case of primary hyperparathyroidism associated with cardiac abnormalities. An 82-year-old male presented with the complaints of chest discomfort, fatigue, general weakness, nausea and vomiting over a period of months and was admitted in July 1996. Physical examination with heart auscultation showed a pansystolic murmur over the right sternal border and apex region, and a blowing diastolic murmur over the left sternal border. Biochemistry profiles revealed elevations of serum calcium (14.3 mg/dl) and chloride/phosphate ratio (> 33). Endocrinological studies showed elevations of serum PTH-C (4.8 ng/ml) and PTH-intact (705 pg/ml) concentrations. Kidney ultrasonography revealed a left renal stone. A spine X-ray revealed spondylosis and a compression fracture of the lumbar-spine with osteoporotic change. Thyroid ultrasonography and Thallium (Tl201)-technetium (Tc99m) subtraction scan showed parathyroid adenoma in the low pole of the right thyroid bed. Parathyroid aspiration cytology revealed few and discrete cells. Echocardiogram revealed moderate to severe aortic valvular calcification as well as stenosis with moderate aortic regurgitation, mitral regurgitation and myocardial calcification. The patient received parathyroidectomy one month later. During his postoperative days, he suffered from muscle twitching with positive Trousseau's sign and Chvostek's sign. The patient received calcium carbonate and vitamin D for hypocalcemia, diltiazem and capoten for his heart problems. A repeated echocardiogram two months after surgery showed no improvement of valvular calcification.

Prolonged survival in a nasopharyngeal carcinoma patient with multiple metastases: a case report and review of the literature

Nasopharyngeal carcinoma is a common cancer in South East Asia. In the early stages, radiotherapy alone may achieve sustained control, but once metastasis occurs, it becomes an incurable disease with limited survival time. We report a case of nasopharyngeal carcinoma, initial stage T4N0M0, diagnosed in 1985 in a patient aged 36 years who received 70 Gy radiotherapy to the head and neck region. In 1988, relapse occurred with multiple lung metastases. The patient received many chemotherapy regimens with a very good response, including near complete remission with the first treatment regimen of cisplatin, 5-fluorouracil and leucovorin for lung metastases, and with the fifth chemotherapy regimen of ifosfamide as a single agent. After ifosfamide treatment, there was residual fibrotic change in the lung and complete disappearance, lasting for almost a year, of the liver and bone lesions. The patient eventually died in July 1995 due to progressive disease. Prolonged survival after mainly thoracic metastasis is possible in patients with nasopharyngeal carcinoma, especially if the tumor is chemo-responsive.

Adenocarcinoma in the middle third of the stomach--an evaluation for the prognostic significance of clinicopathological features

BACKGROUND/AIMS

The prognosis of patients with gastric adenocarcinoma varies with the location of the tumor. Adenocarcinoma in the middle third of the stomach has been claimed to have a better outcome than those in other locations. However, there is still very limited information specifically regarding the prognostic factors which influence the survival time of patients with adenocarcinoma in the middle third of the stomach. This retrospective study was designed with the aim to evaluate and uncover the possible significant clinicopathological parameters for adenocarcinoma in the middle third of the stomach.

METHODOLOGY

Between 1986 and 1992, 363 patients underwent gastric resection for primary gastric adenocarcinoma at this hospital. Fifty-two (14.3%) of these patients were included in this study and they all met the following criteria: 1) tumor primarily located in the middle third of the stomach without distant metastases or peritoneal seeding, 2) undergoing curative resection and 3) undergoing R2 nodal dissection, at least. The clinicopathological findings were obtained by detailed review of the medical records and the histologic slides. All surviving patients were also contacted and their current conditions were recorded.

RESULTS

The overall 5-year survival rate (Kaplan-Meier method) was 42.5%. In univariate survival analysis by Kaplan-Meier method and long-rank test, serosal invasion (p < 0.01), lymph node metastasis (p < 0.01) and lymphatic involvement (p < 0.01) had an individual prognostic significance. When a multivariate analysis using Cox proportional hazards regression was performed, serosal invasion (P < 0.01) and lymphatic involvement (p < 0.05) appeared as the only two independent prognostic factors regarding long-term survival. When these 52 patients were categorized into patients with early gastric cancer (n = 10) and patients with advanced gastric cancer (n = 42), there was a significant difference (p < 0.01) between the survival rates (90.0% vs. 29.1%). When these tumors were further categorized into early gastric cancer (n = 10), early simulating advanced gastric cancer (n = 14) and Borrmann type advanced gastric cancer (n = 28), there were significant differences (P < 0.01 and P < 0.01, respectively) in 5-year overall survival rates between early gastric cancer (90.0%) and Borrmann type advanced gastric cancer (18.9%), also between early simulating advanced gastric cancer (52.5%) and Borrmann type advanced gastric cancer (18.9%). UICC stage also had significant influence (P < 0.01) on the survival rates.

CONCLUSIONS

Serosal invasion and lymphatic involvement are the significant, independent prognostic factors in predicting the survival rate of patients with adenocarcinoma in the middle third of the stomach. Since more advanced stage tumors usually carry a poorer prognosis, early detection is of extreme importance for improving the survival rate.