Scoring system for diagnosis and pretreatment risk assessment of neuroblastoma using urinary biomarker combinations

The urinary catecholamine metabolites, homovanillic acid (HVA) and vanillylmandelic acid (VMA), are used for the adjunctive diagnosis of neuroblastomas. We aimed to develop a scoring system for the diagnosis and pretreatment risk assessment of neuroblastoma, incorporating age and other urinary catecholamine metabolite combinations. Urine samples from 227 controls (227 samples) and 68 patients with neuroblastoma (228 samples) were evaluated. First, the catecholamine metabolites vanillactic acid (VLA) and 3-methoxytyramine sulfate (MTS) were identified as urinary marker candidates through comprehensive analysis using liquid chromatography-mass spectrometry. The concentrations of these marker candidates and conventional markers were then compared among controls, patients, and numerous risk groups to develop a scoring system. Participants were classified into four groups: control, low risk, intermediate risk, and high risk, and the proportional odds model was fitted using the L2-penalized maximum likelihood method, incorporating age on a monthly scale for adjustment. This scoring model using the novel urine catecholamine metabolite combinations, VLA and MTS, had greater area under the curve values than the model using HVA and VMA for diagnosis (0.978 vs. 0.964), pretreatment risk assessment (low and intermediate risk vs. high risk: 0.866 vs. 0.724; low risk vs. intermediate and high risk: 0.871 vs. 0.680), and prognostic factors (MYCN status: 0.741 vs. 0.369, histology: 0.932 vs. 0.747). The new system also had greater accuracy in detecting missing high-risk neuroblastomas, and in predicting the pretreatment risk at the time of screening. The new scoring system employing VLA and MTS has the potential to replace the conventional adjunctive diagnostic method using HVA and VMA.

Abstract 2199: Novel urinary marker for diagnosis and prognosis of neuroblastoma

Background and Aim: Urinary homovanillic acid (HVA) and vanillylmandelic acid (VMA) concentrations are widely used for diagnosis of neuroblastomas, which are catecholamine-secreting tumors. As recent advances in mass spectrometry have facilitated the measurement of metabolites present at extremely low concentrations, urinary metabolites with better diagnostic or prognostic utility for detection of neuroblastomas could be identified. This study utilized quantitative analyses using liquid chromatography-mass spectrometry (LC-MS) to evaluate the diagnostic and prognostic performance of a novel biomarker candidate: 3-methoxytyramine sulfate [3-MTS].

Materials and Methods: The concentrations of the three urinary metabolites (HVA, VMA, and 3-MTS) in urine samples of 41 patients with primary neuroblastoma and urine samples of 155 control participants were measured using LC-MS. The cut-off values for these metabolites were the mean + 2 standard deviation values of the control. Linear discriminant analysis was used to evaluate the association of urinary marker candidates with unfavorable risk factors such as the International Neuroblastoma Pathology Classification and MYCN amplification.

Results: The sensitivity and specificity were as follows: 3-MTS 90.2%, 94.2%; HVA 87.8%, 96.1%; VMA 87.8%, 96.1%; VMA or HVA+3-MTS 97.6%, 92.3%; HVA+VMA 87.8%, 94.8%; respectively. 3-MTS could differentiate between the cases with favorable and unfavorable histology (AUC =0.950). 3-MTS+VMA differentiated between the cases with MYCN amplification and nonamplification (AUC=0.952).

Conclusions: 3-MTS might be a useful urine marker for both diagnosis and prognosis of neuroblastoma.

Citation Format: Akinari Hinoki, Hizuru Amano, Hiroo Uchida, Atsushi Narita, Shun Kumano, Mayumi Abe, Minoru Sakairi, Chiyoe Shirota, Wataru Sumida, Satoshi Makita, Yoshiyuki Takahashi, Tsuyoshi Osawa. Novel urinary marker for diagnosis and prognosis of neuroblastoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 2199.

Tomography and gravitational radii for hadrons by three-dimensional structure functions

Three-dimensional tomography of hadrons can be investigated by generalized parton distributions (GPDs), transverse-momentum-dependent parton distributions (TMDs), and generalized distribution amplitudes (GDAs). The GDA studies had been only theoretical for a long time because there was no experimental measurement until recently, whereas the GPDs and TMDs have been investigated extensively by deeply vir- tual Compton scattering and semi-inclusive deep inelastic scattering. Here, we report our studies to determine pion GDAs from recent KEKB measurements on the differen- tial cross section of γ*γ → π0π0. Since an exotic-hadron pair can be produced in the final state, the GDAs can be used also for probing internal structure of exotic hadron candidates in future. The other important feature of the GDAs is that the GDAs contain information on form factors of the energy-momentum tensor for quarks and gluons, so that gravitational form factors and radii can be calculated from the determined GDAs. We show the mass (energy) and the mechanical (pressure, shear force) form factors and radii for the pion. Our analysis should be the first attempt for obtaining gravitational form factors and radii of hadrons by analysis of actual experimental measurements. We believe that a new field of gravitational physics is created from the microscopic level in terms of elementary quarks and gluons.

Towards a unified model of neutrino-nucleus reactions for neutrino oscillation experiments

A precise description of neutrino-nucleus reactions will play a key role in addressing fundamental questions such as the leptonic CP violation and the neutrino mass hierarchy through analyzing data from next-generation neutrino oscillation experiments. The neutrino energy relevant to the neutrino-nucleus reactions spans a broad range and, accordingly, the dominant reaction mechanism varies across the energy region from quasi-elastic scattering through nucleon resonance excitations to deep inelastic scattering. This corresponds to transitions of the effective degree of freedom for theoretical description from nucleons through meson-baryon to quarks. The main purpose of this review is to report our recent efforts towards a unified description of the neutrino-nucleus reactions over the wide energy range; recent overall progress in the field is also sketched. Starting with an overview of the current status of neutrino-nucleus scattering experiments, we formulate the cross section to be commonly used for the reactions over all the energy regions. A description of the neutrino-nucleon reactions follows and, in particular, a dynamical coupled-channels model for meson productions in and beyond the [Formula: see text](1232) region is discussed in detail. We then discuss the neutrino-nucleus reactions, putting emphasis on our theoretical approaches. We start the discussion with electroweak processes in few-nucleon systems studied with the correlated Gaussian method. Then we describe quasi-elastic scattering with nuclear spectral functions, and meson productions with a [Formula: see text]-hole model. Nuclear modifications of the parton distribution functions determined through a global analysis are also discussed. Finally, we discuss issues to be addressed for future developments.

Probe Heating Method for the Analysis of Solid Samples Using a Portable Mass Spectrometer

We previously reported on the development of a portable mass spectrometer for the onsite screening of illicit drugs, but our previous sampling system could only be used for liquid samples. In this study, we report on an attempt to develop a probe heating method that also permits solid samples to be analyzed using a portable mass spectrometer. An aluminum rod is used as the sampling probe. The powdered sample is affixed to the sampling probe or a droplet of sample solution is placed on the tip of the probe and dried. The probe is then placed on a heater to vaporize the sample. The vapor is then introduced into the portable mass spectrometer and analyzed. With the heater temperature set to 130°C, the developed system detected 1 ng of methamphetamine, 1 ng of amphetamine, 3 ng of 3,4-methylenedioxymethamphetamine, 1 ng of 3,4-methylenedioxyamphetamine, and 0.3 ng of cocaine. Even from mixtures consisting of clove powder and methamphetamine powder, methamphetamine ions were detected by tandem mass spectrometry. The developed probe heating method provides a simple method for the analysis of solid samples. A portable mass spectrometer incorporating this method would thus be useful for the onsite screening of illicit drugs.

Free nucleosides and bases in the hyperkeratotic epidermis

The metabolism of both free nucleosides and bases in hyperkeratosis induced by topical application of n-hexadecane on the epidermis of guinea pig was discussed, based on the technique of high-pressure liquid chromatography. The level of nucleosides and bases decreased in the hyperkeratotic stage of epidermis, in spite of the high concentration of nucleotides. The concentration of purine bases in the epidermis was under the virtual control of the salvage enzyme pathway and uric acid formation. The significant increase of salvage enzyme activity with phosphoribosylation was responsible for the expansion of the purine nucleotide pool in the hyperkeratotic epidermis. It was noted that the increased nucleotide pool plays a role as a source of cellular energy and a precursor of nucleic acid for epidermal proliferation.

High-pressure liquid chromatography of free nucleotide patterns in normal and abnormal keratinocytes

A method for analyzing free nucleotides in the epidermis of the guinea pig is presented. Free nucleotides were extracted by using a methylalethanol mixture, and the analysis was carried out by high-pressure liquid chromatography on a column of Lichrosorb-NH2 with a single buffer of potassium phosphate. The concentration of total free nucleotides in the epidermis is about 4 times greater than that in the liver, kidney, spleen, or intestinal epithelium.l The free nucleotide level is markedly elevated in the hyperkeratotic epidermis induced by n-hexadecane. The alternation of free nucleotides in hyperkeratotic epidermis is discussed in relation to nucleic acid content, DNase, disc-electrophoretic properties of DNase, and salvage pathway enzymatic activity. Significant increases in the enzyme activity of the salvage pathway and in neutral DNase were observed in the hyperkeratotic stage. However, the DNA content and acid DNase activity were decreased. It is suggested that the pool size of free nucleotides in the epidermis is affected by the salvage enzyme system.

Sensitive low-pressure dielectric barrier discharge ion source

RATIONALE

We developed a novel highly sensitive soft ionization method: a low-pressure dielectric barrier discharge ionization (LP-DBDI) source. In this configuration, samples pass through the inside of a dielectric barrier discharge (DBD). Since samples pass through a DBD and its plasma jet, high ionization efficiency is expected. Furthermore, high transmission efficiency from the ion source to the mass spectrometer is also expected since the ion source is placed in a vacuum.

METHODS

Mass spectrometric detection was carried out in positive ion mode using an ion trap mass spectrometer. The LP-DBDI source or a conventional atmospheric pressure chemical ionization (APCI) source was attached to the mass spectrometer. Samples were vaporized and sent to ion sources with air flowing at a constant flow rate of 1.5 L/min. The LP-DBDI source was compared with a conventional APCI source.

RESULTS

Mass spectra of methyl salicylate, 2-undecanone and methamphetamine were acquired using the LP-DBDI source. Protonated molecules were mainly observed in the mass spectra. The sensitivities for methyl salicylate and 2-undecanone obtained using the LP-DBDI source were 44 times and 39 times higher, respectively, than those obtained using an APCI source.

CONCLUSIONS

LP-DBDI is a soft ionization method characterized by only minor fragmentation, similar to APCI. The sensitivity of the LP-DBDI source was found to be about 40 times higher than that of the conventional APCI source.

CT and MR cholangiography: advantages and pitfalls in perioperative evaluation of biliary tree

Recent developments in imaging technology have enabled CT and MR cholangiopancreatography (MRCP) to provide minimally invasive alternatives to endoscopic retrograde cholangiopancreatography for the pre- and post-operative assessment of biliary disease. This article describes anatomical variants of the biliary tree with surgical significance, followed by comparison of CT and MR cholangiographies. Drip infusion cholangiography with CT (DIC-CT) enables high-resolution three-dimensional anatomical representation of very small bile ducts (e.g. aberrant branches, the caudate branch and the cystic duct), which are potential causes of surgical complications. The disadvantages of DIC-CT include the possibility of adverse reactions to biliary contrast media and insufficient depiction of bile ducts caused by liver dysfunction or obstructive jaundice. Conventional MRCP is a standard, non-invasive method for evaluating the biliary tree. MRCP provides useful information, especially regarding the extrahepatic bile ducts and dilated intrahepatic bile ducts. Gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid-enhanced MRCP may facilitate the evaluation of biliary structure and excretory function. Understanding the characteristics of each type of cholangiography is important to ensure sufficient perioperative evaluation of the biliary system.

Atomic force microscopy imaging of the structure of the motor protein prestin reconstituted into an artificial lipid bilayer

Prestin is the motor protein of cochlear outer hair cells and is essential for mammalian hearing. The present study aimed to clarify the structure of prestin by atomic force microscopy (AFM). Prestin was purified from Chinese hamster ovary cells which had been modified to stably express prestin, and then reconstituted into an artificial lipid bilayer. Immunofluorescence staining with anti-prestin antibody showed that the cytoplasmic side of prestin was possibly face up in the reconstituted lipid bilayer. AFM observation indicated that the cytoplasmic surface of prestin was ring-like with a diameter of about 11 nm.

Salicylate-induced translocation of prestin having mutation in the GTSRH sequence to the plasma membrane

Prestin is a key molecule for mammalian hearing. The present study investigated changes in characteristics of prestin by culturing prestin-transfected cells with salicylate, an antagonist of prestin. As a result, the plasma membrane localization of prestin bearing a mutation in the GTSRH sequence, which normally accumulates in the cytoplasm, was recovered. Moreover, the nonlinear capacitance of the majority of the mutants, which is a signature of prestin activity, was also recovered. Thus, the present study discovered a new effect of salicylate on prestin, namely, the promotion of the plasma membrane expression of prestin mutants in an active state.

Effects of heat stress on filamentous actin and prestin of outer hair cells in mice

When the ear is exposed to traumatic loud noise, outer hair cells (OHCs) are damaged and thus permanent hearing loss occurs. Recently, prior conditioning with heat stress has been reported to protect OHCs from traumatic noise exposure by increasing the stiffness of the OHC soma and has also been reported to enhance distortion product otoacoustic emissions [DPOAEs; Murakoshi, M., Yoshida, N., Kitsunai, Y., Iida, K., Kumano, S., Suzuki, T., Kobayashi, T., Wada, H., 2006. Effects of heat stress on Young's modulus of outer hair cells in mice. Brain Res. 1107, 121-130]. In the present study, to further investigate the heat stress-induced protective mechanism of hearing and such stress-induced DPOAE enhancement mechanism, the amount of filamentous actin (F-actin), which is concerned with cell stiffness, and the amount of prestin, which is concerned with the generation of DPOAEs, were examined in OHCs, with and without heat stress. Heat stress was found to increase the amount of F-actin 6-24 h after heat stress. The greatest increase in the amount of F-actin was observed at the cuticular plate where F-actin anchors the roots of the stereocilia to the cell body. Based on this result, the part of the stereocilia most reinforced and protected by heat stress was concluded to be the roots of the stereocilia. In contrast with F-actin, heat stress did not affect the amount of prestin.

Effects of heat stress on Young's modulus of outer hair cells in mice

Intense sound exposure causes permanent hearing loss due to hair cell and cochlear damage. Prior conditioning with sublethal stressors, such as nontraumatic sound, heat stress and restraint protects the ear from acoustic injury. However, the mechanisms underlying conditioning-related cochlear protection remain unknown. In this paper, Young's modulus and the amount of filamentous actin (F-actin) of outer hair cells (OHCs) with/without heat stress were investigated by atomic force microscopy and confocal laser scanning microscopy, respectively. Conditioning with heat stress resulted in a statistically significant increase in Young's modulus of OHCs at 3-6 h after application, and such modulus then began to decrease by 12 h and returned to pre-conditioning level at 48 h after heat stress. The amount of F-actin began to increase by 3 h after heat stress and peaked at 12 h. It then began to decrease by 24 h and returned to the pre-conditioning level by 48-96 h after heat stress. These time courses are consistent with a previous report in which heat stress was shown to suppress permanent threshold shift (PTS). In addition, distortion product otoacoustic emissions (DPOAEs) were confirmed to be enhanced by heat stress. These results suggest that conditioning with heat stress structurally modifies OHCs so that they become stiffer due to an increase in the amount of F-actin. As a consequence, OHCs possibly experience less strain when they are exposed to loud noise, resulting in protection of mammalian hearing from traumatic noise exposure.

Imaging by atomic force microscopy of the plasma membrane of prestin-transfected Chinese hamster ovary cells

The high sensitivity of mammalian hearing is achieved by amplification of the motion of the cochlear partition. This cochlear amplification is thought to be generated by the elongation and contraction of outer hair cells (OHCs) in response to acoustical stimulation. This motility is made possible by a membrane protein embedded in the lateral membrane of OHCs. Although a fructose transporter, GLUT-5, was initially proposed to be this protein, a later study identified the gene of the motor protein distributed throughout the OHC plasma membrane. This protein has been named "prestin." However, although previous morphological studies by electron microscopy and atomic force microscopy (AFM) found the lateral wall of OHCs to be covered with 10-nm particles, believed to be motor proteins, it is unknown whether such particles consist only of prestin or are a complex of GLUT-5 and prestin molecules. To determine if the 10-nm particles are indeed constituted only of prestin, plasma membranes of prestin-transfected and untransfected Chinese hamster ovary (CHO) cells, which do not express GLUT-5, were observed by AFM. First, the cells attached to a substrate were sonicated so that only the plasma membrane remained on the substrate. The cytoplasmic face of the cell was observed by the tapping mode of the AFM in liquid. As a result, particle-like structures were recognized on the plasma membranes of both the prestin-transfected and untransfected CHO cells. Comparison of the difference in the frequency distribution of these structures between those two cells showed approximately 75% of the particle-like structures with a diameter of 8-12 nm in the prestin-transfected CHO cells to be possibly constituted only by prestin molecules. Our data suggest that the densely packed 10-nm particles observed on the OHC lateral wall are likely to be constituted only of prestin molecules.

Local mechanical properties of mouse outer hair cells: atomic force microscopic study

OBJECTIVES

Outer hair cells (OHCs) are capable of altering their cell length in response to changes in membrane potential. Due to this electromotility, OHCs probably subject the basilar membrane to force, resulting in cochlear amplification. To understand the mechanism of such amplification, knowledge of the mechanical properties of OHCs is required since the force produced by OHC electromotility is thought to depend on such properties. Various studies have been conducted to investigate the mechanical properties of guinea pig OHCs. With regard to mice, however, although various kinds of transgenic and knockout mice possess great potential as research models, the mechanical properties of mouse OHCs have not as yet been reported since the cells and/or tissues in the mouse hearing organ are relatively small and vulnerable to external stimuli, rendering sample preparation difficult. In this study, therefore, to establish indicators of the mechanical properties of OHCs in mice, such properties were measured by atomic force microscopy (AFM).

METHODS

CBA/JNCrj strain male mice aged 10-12 weeks (25-30 g) were used. Cochleae were dissected out from the animal and both the basilar membrane and the organ of Corti were simultaneously unwrapped from the modiolus with forceps. Dissected coiled tissue was then incubated with an enzymatic digestion medium for 15 min. After digestion, OHCs were isolated by gently triturating the coiled tissue. Local mechanical properties of the OHCs were then measured by an indentation test using an AFM.

RESULTS

Young's modulus and stiffness of the OHC in the apical turn of the mouse cochlea were 2.1+/-0.5 kPa and 4.4+/-1.2 mN/m, respectively.

CONCLUSIONS

Young's modulus of the OHC in the apical turn of the cochlea in mice was roughly the same as that in the apical turn of the cochlea in guinea pigs; however, the stiffness of the former was about two times greater than that of the latter because the cell length of the former was shorter than that of the latter.

Stimulation effect of galanin-like peptide (GALP) on luteinizing hormone-releasing hormone-mediated luteinizing hormone (LH) secretion in male rats

Galanin-like peptide (GALP) is a recently isolated hypothalamic peptide which has sequence homology to galanin and binds to galanin receptors with high affinity. It has been shown that GALP neurons are localized in the arcuate nucleus and that GALP-immunoreactive fibers are in close apposition with LHRH neurons in the medial preoptic area (MPA). In the present study, we found that intracerebroventricular (icv) administration of GALP increased the plasma LH level but did not change the levels of other hormones. Concomitantly, accumulation of c-Fos protein was dramatically increased in the nuclei of LHRH-positive cells in the MPA by icv GALP administration. Furthermore, the GALP-induced plasma LH response was completely abolished by pretreatment with Cetrorelix, a LHRH receptor antagonist. On the other hand, GALP did not affect the release of LH, FSH, TSH, ACTH, GH or PRL directly from dispersed rat pituitary cells in vitro. These results strongly suggest a role for GALP in the control of gonadotropin secretion through a hypothalamic mechanism involving the release of LHRH.

Metastasis suppressor gene KiSS-1 encodes peptide ligand of a G-protein-coupled receptor

Metastasis is a major cause of death in cancer patients and involves a multistep process including detachment of cancer cells from a primary cancer, invasion of surrounding tissue, spread through circulation, re-invasion and proliferation in distant organs. KiSS-1 is a human metastasis suppressor gene, that suppresses metastases of human melanomas and breast carcinomas without affecting tumorigenicity. However, its gene product and functional mechanisms have not been elucidated. Here we show that KiSS-1 (refs 1, 4) encodes a carboxy-terminally amidated peptide with 54 amino-acid residues, which we have isolated from human placenta as the endogenous ligand of an orphan G-protein-coupled receptor (hOT7T175) and have named 'metastin'. Metastin inhibits chemotaxis and invasion of hOT7T175-transfected CHO cells in vitro and attenuates pulmonary metastasis of hOT7T175-transfected B16-BL6 melanomas in vivo. The results suggest possible mechanisms of action for KiSS-1 and a potential new therapeutic approach.

Distribution of galanin-like peptide in the rat brain

Galanin-like peptide (GALP) is a novel galanin-like peptide isolated from the porcine hypothalamus. To determine the distribution of GALP in the rat brain, we performed immunohistochemical studies using a monoclonal antibody toward the N-terminal sequence of GALP. GALP-immunoreactive neuronal cell bodies were observed only in the arcuate nucleus (Arc), which was further confirmed by in situ hybridization studies using digoxigenin-labeled antisense GALP riboprobe. Additional immunostained cells were found in the median eminence and infundibular stalk. The GALP neurons found in the Arc were further characterized by double label immunohistochemistry. More than 85% of the GALP neurons were immunostained with leptin receptor antibody. However, the GALP neurons and fibers found in the Arc were not labeled with alpha-MSH, somatostatin, neuropeptide Y, agouti-related protein, or galanin antibodies, indicating that GALP is found in neurons other than these known Arc neurons. Dense staining of GALP-containing fibers was found in the anterior parvicellular part of the paraventricular hypothalamic nucleus, in the ventral part of the lateral septal nucleus, and in the bed nucleus of the stria terminalis. Relatively dense staining was noted in the medial preoptic area (MPA), and weak staining was noted in the periventricular hypothalamic nucleus. Detailed double labeling studies in the paraventricular hypothalamic nucleus demonstrated that GALP-containing fibers converged in a more rostral direction than did agouti-related protein-containing fibers. Furthermore, GALP-immunoreactive fibers were in close apposition with GnRH-immunoreactive fibers in the MPA and bed nucleus of the stria terminalis, and about 6% of GnRH-positive neurons in the MPA showed close contact with the GALP-immunoreactive fibers. Our findings indicate that GALP neurons, as leptin-responsive neurons, may participate in the regulation of feeding behavior and/or reproductive functions.

Isolation and cDNA cloning of a novel galanin-like peptide (GALP) from porcine hypothalamus

Galanin is a widely distributed neuropeptide with a variety of physiological functions. Three galanin receptor subtypes, GALR1, GALR2, and GALR3, have been reported. We isolated a novel galanin-like peptide (GALP) from porcine hypothalamus by observing its activity for increasing [(35)S]GTPgammaS binding to a membrane preparation of GALR2-transfected cells. The peptide had 60 amino acid residues and a non-amidated C terminus. The amino acid sequence of GALP-(9-21) was completely identical to that of galanin-(1-13). A cloned porcine GALP cDNA indicated that GALP was processed from a 120-amino acid GALP precursor protein. The structures of rat and human GALP-(1-60) were deduced from cloned cDNA, which indicated that the amino acid sequences 1-24 and 41-53 were highly conserved between humans, rats, and pigs. Receptor binding studies revealed that porcine GALP-(1-60) had a high affinity for the GALR2 receptor (IC(50) = 0.24 nM) and a lower affinity for the GALR1 receptor (IC(50) = 4.3 nM). In contrast, galanin showed high affinity for the GALR1 (IC(50) = 0.097 nM) and GALR2 receptors (IC(50) = 0.48 nM). GALP is therefore an endogenous ligand that preferentially binds the GALR2 receptor, whereas galanin is relatively non-selective.

Sequence and organization of pXO1, the large Bacillus anthracis plasmid harboring the anthrax toxin genes

The Bacillus anthracis Sterne plasmid pXO1 was sequenced by random, "shotgun" cloning. A circular sequence of 181,654 bp was generated. One hundred forty-three open reading frames (ORFs) were predicted using GeneMark and GeneMark.hmm, comprising only 61% (110,817 bp) of the pXO1 DNA sequence. The overall guanine-plus-cytosine content of the plasmid is 32.5%. The most recognizable feature of the plasmid is a "pathogenicity island," defined by a 44.8-kb region that is bordered by inverted IS1627 elements at each end. This region contains the three toxin genes (cya, lef, and pagA), regulatory elements controlling the toxin genes, three germination response genes, and 19 additional ORFs. Nearly 70% of the ORFs on pXO1 do not have significant similarity to sequences available in open databases. Absent from the pXO1 sequence are homologs to genes that are typically required to drive theta replication and to maintain stability of large plasmids in Bacillus spp. Among the ORFs with a high degree of similarity to known sequences are a collection of putative transposases, resolvases, and integrases, suggesting an evolution involving lateral movement of DNA among species. Among the remaining ORFs, there are three sequences that may encode enzymes responsible for the synthesis of a polysaccharide capsule usually associated with serotype-specific virulent streptococci.

Sequence, assembly and analysis of pX01 and pX02

Bacillus anthracis plasmids pX01 and pX02, harboured by the Sterne and Pasteur strains, respectively, have been sequenced by random 'shotgun' cloning and high throughout sequence analysis. These sequences have been assembled (Sequencher) to generate a circulate pX01 plasmid containing 181 656 bp and a single linear (gapped) pX02 contig containing at least 93.479 bp. Initial annotation suggests that the two plasmids combined contain at least 200 potential open reading frames (ORFs) with < 40% having significant similarity to sequences registered in open databases. Collectively, only 118 566 bp of the pX01 DNA (65%) represent predicted coding regions. This value is similar to published gene densities for other plasmids and is indicative of the larger intergenic spaces in plasmids vs those found in the chromosomes of the parental microbes (85-93% gene density). A 70 kbp region including the toxin genes (cya, lef and pag) is distinct from the remainder of the pX01 sequence: (1) it has a lower gene density (58 vs 70%) than the remaining 111 kbp; (2) it contains all but one of the co-regulated transcriptional fusions identified by transposon mutagenesis (Hoffmaster & Koehler 1997) and (3) it contains a significantly higher proportion of positive BLAST scores (62 vs 20%) for putative ORFs. These data suggest different origins for the two regions of pX01.

Requirement for the kinase activity of human DNA-dependent protein kinase catalytic subunit in DNA strand break rejoining

The catalytic subunit of DNA-dependent protein kinase (DNA-PKcs) is an enormous, 470-kDa protein serine/threonine kinase that has homology with members of the phosphatidylinositol (PI) 3-kinase superfamily. This protein contributes to the repair of DNA double-strand breaks (DSBs) by assembling broken ends of DNA molecules in combination with the DNA-binding factors Ku70 and Ku80. It may also serve as a molecular scaffold for recruiting DNA repair factors to DNA strand breaks. This study attempts to better define the role of protein kinase activity in the repair of DNA DSBs. We constructed a contiguous 14-kb human DNA-PKcs cDNA and demonstrated that it can complement the DNA DSB repair defects of two mutant cell lines known to be deficient in DNA-PKcs (M059J and V3). We then created deletion and site-directed mutations within the conserved PI 3-kinase domain of the DNA-PKcs gene to test the importance of protein kinase activity for DSB rejoining. These DNA-PKcs mutant constructs are able to express the protein but fail to complement the DNA DSB or V(D)J recombination defects of DNA-PKcs mutant cells. These results indicate that the protein kinase activity of DNA-PKcs is essential for the rejoining of DNA DSBs in mammalian cells. We have also determined a model structure for the DNA-PKcs kinase domain based on comparisons to the crystallographic structure of a cyclic AMP-dependent protein kinase. This structure gives some insight into which amino acid residues are crucial for the kinase activity in DNA-PKcs.

Detection of telomerase activity in prostate cancer by needle biopsy

OBJECTIVES

Re-expression of telomerase is believed to play an important role in immortalization and carcinogenesis. Thus, telomerase activity is considered to be a potentially useful diagnostic marker. We evaluated the potential diagnostic use of assaying telomerase activity in needle biopsy samples of prostate.

METHODS

114 were obtained from 38 patients with suspected cancer who underwent transrectal ultrasound-guided systematic prostate needle biopsy. Two samples were obtained per site for histological examination and telomerase assay. The activity was assayed using the telomeric repeat amplification protocol and correlated with histological findings.

RESULTS

Of the total of 114 samples, 57 were obtained from 22 prostate cancer patients. Telomerase activity was detected in 66% (25/38) of the samples which were histologically confirmed to contain cancerous cells and in 11% (2/19) of the samples from adjacent noncancerous tissues. Of 22 patients with prostate cancer, 82% were positive for telomerase activity in one or more samples by needle biopsy, whereas 1 of 16 patients without histologically cancerous tissues was positive for the telomerase.

CONCLUSIONS

The results indicate that telomerase activity in needle biopsy samples is a useful diagnostic marker of prostate cancer.

Comparison of adenosine triphosphate and dipyridamole in diagnosis by thallium-201 myocardial scintigraphy

We examined whether 201Tl myocardial scintigraphy with intravenous infusion of adenosine triphosphate (ATP) can be substituted for dipyridamole (DIP) in the diagnosis of coronary artery disease CAD).

METHODS

The coronary flow reserve (CFR) during intravenous infusion of ATP (0.10-0.20 mg/kg/min) was compared with that during intravenous infusion of DIP (0.56 mg/kg) using a Doppler flow wire in 19 subjects with normal coronary arteries. The highest CFR level was found in the ATP dose range of 0.16-0.20 mg/kg/min. The CFR at the ATP dose of 0.16 mg/kg/min was significantly higher than that during DIP infusion (4.2 versus 3.6) (p < 0.01), for which reason we adopted this dose of ATP. According, 201Tl SPECT in 140 patients with suspected CAD was performed after infusion of 0.16 mg/kg/min of ATP in 70 of them and 0.56 mg/kg of DIP in the 70 others.

RESULTS

ATP stress 201Tl SPECT showed no significant difference in sensitivity and accuracy from DIP stress 201Tl SPECT (87.0% versus 82.9, and 87.1% versus 78.6, respectively). Adverse effects occurred at higher frequency when ATP was used, but they were mild and disappeared rapidly after administration was stopped.

CONCLUSION

ATP stress 201Tl SPECT is accurate and safe. The optimal ATP regimen for this purpose is considered to be a 5-min infusion at 0.16 mg/kg/min. However, our data in CAD patients suggest that ATP stress 201Tl SPECT is equivalent to DIP stress 201Tl SPECT in the detection of CAD.

[Usefulness of 123I-BMIPP myocardial scintigraphy for evaluation of the left ventricular function in patients with chronic heart failure]

We examined the relationship between free fatty acid metabolism using 123I beta-methyl-iodophenyl-pentadecanoic acid (BMIPP) and cardiac function in patients with chronic heart failure (CHF). Cardiac free fatty acid metabolism was evaluated by the heart to mediastinum ratio (H/M), the heart to lung ratio (H/Lu), the heart to liver ratio (H/Li) and the myocardial uptake ratio (MUR) obtained from the planar imaging. Cardiac function was evaluated by the percent of fractional shortening (%FS) and the amount of left ventricular mass (LV mass) calculated with echocardiography. The study included 34 male and 14 female subjects of CHF with mean age of 61 +/- 9 years; dilated cardiomyopathy (DCM): n = 17, ischemic heart disease (IHD): n = 16, valvular disease: n = 5, hypertrophic cardiomyopathy: n = 4, hypertension: n = 4, amyloidosis: n = 2. The correlations between indices of BMIPP uptake and those of echocardiography were as follows: H/M vs. %FS (r = 0.67, p < 0.01), H/Lu vs. %FS (r = 0.49, p < 0.01), H/Li vs. %FS (r = 0.12, p = 0.42), MUR vs. %FS (r = 0.03, p = 0.86) and MUR/LV mass vs. %FS (r = 0.59, p < 0.01). The correlation coefficient between H/M and MUR/LV mass in patients with IHD was higher than that in patients with DCM. In conclusion, BMIPP, in particular, is a useful tool for evaluating cardiac function in patients with CHF.

[99mTc-MIBI myocardial tomography with intravenous infusion of adenosine triphosphate in the diagnosis of coronary artery disease]

To evaluate its feasibility, safety and diagnostic accuracy, 99mTc-MIBI myocardial tomography with adenosine triphosphate (ATP) infusion (0.16 mg/kg/min for 5 min) was performed 100 consecutive patients using the stress/rest one day protocol. None of the patients required treatment with aminophylline during the study. The sensitivity and specificity for detecting patients with coronary artery disease were 97% and 71%, respectively. Those for detecting individual coronary lesion (> or = 75% stenosis) were 92% and 89%, respectively. The high hepatic uptake of 99mTc-MIBI causes artifactual perfusion defects in the inferior myocardial wall, particularly on ATP stress images. In order to reduce this artifactual phenomenon, the interval time between injection and stress imaging must be increased.

Cosmids and transcribed sequences from chromosome 11q23

To obtain cosmid markers and transcribed sequences from a specific chromosome region, a series of radiation-reduced hybrids (RHs) containing various regions of human chromosome 11 was prepared from microcell hybrid A9 (neo11) cells containing a normal human chromosome 11 tagged with pSV2neo at 11p11.2. Among 15 radiation hybrid clones isolated, RH(11)-9 which contains a q23 fragment in addition to the neo integration site, was used for the construction of a cosmid library. Cosmid clones having human DNA sequences were screened, and localized by Southern hybridization with the radiation hybrid panel. Fifty-nine cosmids were assigned to 11q23 and 6 cosmids to 11p11.2. Exon amplification proceeded with 23 of the 59 cosmids and 16 putative exons were cloned. Three of them were identical to those constituting a known gene which locates on q23 (ATDC), and the others were unknown. Thus, the RHs containing various subchromosomal fragments of chromosome 11 were useful for constructing region-specific DNA markers. The RH(11)-9 cells and putative exons also facilitate the positional cloning of genes in the 11q23 region.

Thallium-201 myocardial tomography with intravenous infusion of adenosine triphosphate in diagnosis of coronary artery disease

OBJECTIVES

The purpose of this study was to evaluate the feasibility, safety and diagnostic accuracy of thallium-201 myocardial tomography with intravenous adenosine triphosphate (ATP) infusion in patients with suspected coronary artery disease.

BACKGROUND

Both ATP and adenosine are potent coronary vasodilators with a very short half-life. Several studies have confirmed that the diagnostic accuracy of adenosine thallium-201 scintigraphy is comparable to that with exercise. However, a high incidence of side effects, including atrioventricular (AV) block, has also been reported. Because the appropriate infusion rate for ATP has not yet been determined, this agent has not been tested in combination with myocardial scintigraphy.

METHODS

The study group included 253 consecutive patients who underwent thallium-201 myocardial tomography with ATP infusion (0.16 mg/kg body weight per min for 5 min). The occurrence of adverse effects was carefully monitored. Of the 120 patients with coronary angiography, 76 had significant coronary artery disease. Tomographic images were assessed visually and by computer-quantified polar maps, and they were compared with the results of coronary angiography.

RESULTS

Although 56% of the patients had some adverse effects, they were transient and mild. In all patients, the ATP infusion protocol could be completed, and no patient required aminophylline; AV block occurred in only 2% of the patients. The sensitivity and specificity were 88% and 80%, respectively, by visual analysis and 91% and 86%, respectively, by computer quantification.

CONCLUSIONS

Thallium tomography with ATP is feasible and has a diagnostic value similar to that with adenosine for detecting coronary artery disease. In addition, it may have fewer side effects than adenosine myocardial tomography.

Construction of 110 cosmid markers and a 4.5-Mb YAC contig on human chromosome 8p12-q11

Microcell hybrids containing various regions of human chromosome 8 were formed by microcell-mediated transfer of neo-tagged chromosome 8 into the cells derived from severe combined immunodeficiency (SCID) mouse. Thus, 110 cosmid markers were isolated from SV40-transformed SCID fibroblast cell line (SCVA) containing a p12-q11.1 region of human chromosome 8 and were assigned to eight regions in 8p12-q11.1, using a microcell-hybrid panel. For positional cloning of a human gene that restores the DNA-repair defect in a mouse with SCID on 8p11.1-q11.1 (SCID region), we constructed a yeast artificial chromosome (YAC) contig of about 4.5 Mb. Overlapping YACs were further aligned by restriction mapping, using rare-cutting restriction endonucleases. The cosmids and YAC contig should facilitate isolation of the SCID gene and other genes, such as the Werner syndrome-responsible gene in or near this region.

Malignant lymphoma of the esophagus associated with macroglobulinemia: report of a case

A case of non-Hodgkin's lymphoma of the esophagus in a 74 year old man is presented. Grossly, the surgically removed esophagus had a fusiform submucosal mass covered with smooth surfaced mucosa. Microscopic examination revealed that the mass consisted of a dense infiltrate of small to medium-sized lymphoid cells with plasmacytoid differentiation, leading to a diagnosis of diffuse small cell lymphoma with lymphoplasmacytic subtype. Laboratory data as well as immunohistochemical studies proved that the lymphoma produced monoclonal immunoglobulin M, giving rise to macroglobulinemia.

[Assessment of myocardial viability by thallium-201 reinjection imaging with sublingual nitroglycerin]

Although thallium-201 (201Tl) reinjection imaging improves the detection of myocardial viability compared to standard 3-4-hr redistribution (RD) imaging, it still underestimates the extent of viable myocardium. We examined whether 201Tl reinjection SPECT with sublingual nitroglycerin (NTG) had a higher sensitivity for viability detection than reinjection alone. Eighty patients with coronary artery disease were studied, 38 of them with an old myocardial infarction. At the peak of exercise, 111 MBq 201Tl was injected and the initial and the delayed SPECT images were obtained. Then, all patients were divided randomly into two groups, and in each group, SPECT data were obtained again after the injection of 37 MBq 201Tl with (NTG(+) group) or without 0.6 mg of sublingual NTG (NTG(-) group). Among 50 segments showing fixed defects on the delayed image in the NTG(+) group, 21 (42%) were found to be reversible on the reinjection image, as compared to 16 of 51 (31%) in the NTG(-) group. Twenty-two of 44 (50%) segments showing incomplete RD were found to be reversible in the NTG(+) group, while 17 of 42 (41%) segments in the NTG(-) group. Moreover, the ratio of reversible segments seen in the reinjection images was significantly higher in the collateralized regions of the NTG(+) group than in those of the NTG(-) group (20/26 vs. 14/28, p < 0.05). Thus, 201Tl reinjection SPECT with sublingual NTG improves the detection of ischemic but viable myocardium as compared to SPECT with reinjection alone.