Usefulness of the G8 Geriatric Assessment Tool as a Prognostic Factor in Gemcitabine Plus Nab-paclitaxel Combination Therapy for Elderly Patients with Pancreatic Cancer

INTRODUCTION

The usefulness of various prognostic factors for advanced pancreatic cancer (APC) has been reported, but the number of elderly patients in these studies is disproportionately fewer than those in general practice. This study aimed to examine the prognostic factors for elderly patients with APC receiving gemcitabine plus nab-paclitaxel (GnP) considering the G8 geriatric assessment tool.

METHODS

We retrospectively analyzed 77 elderly (≥65 years old) patients with APC who received GnP as first-line chemotherapy at our hospital. We used the receiver operating characteristic curve to set the optimal cutoff value for G8. Univariate and multivariate Cox regression models were applied to study independent prognostic factors.

RESULTS

The progression-free survival was 5.5 months, and the overall survival (OS) was 12.0 months in all patients. The most optimal cutoff of G8 was 10.5. OS of G8 ≥10.5 patients was superior to that of G8 <10.5 patients (18.5 versus 8.0 months). Multivariate analysis showed that Eastern Cooperative Oncology Group performance status 1 (hazard ratio [HR] 3.00, p = 0.02), neutrophil-lymphocyte ratio ≥3.9 (HR 2.73, p = 0.03), and G8 geriatric assessment <10.5 (HR 5.38, p < 0.001) were independent negative prognostic factors.

CONCLUSIONS

G8 is useful for predicting prognoses in elderly patients with APC receiving GnP.

Fracture of a Self-expandable Metallic Stent Inserted for Malignant Gastric Outlet Obstruction

Duodenal stenting has gradually been established as the first-line treatment for malignant gastric outlet obstruction (GOO). We encountered a case of duodenal stent fracture in a 76-year-old woman with gastric cancer and GOO. She underwent self-expandable metallic stent (SEMS) placement. The SEMS was found to be fractured 4 weeks after its placement. We removed the broken part of the stent and placed a second SEMS. SEMS fracture is a rare and - to the best of our knowledge - unreported complication; hence, clinicians and their patients should be aware of this possibility.

Asymptomatic Common Bile Duct Stones Are Associated with Increased Risk of Post-Endoscopic Retrograde Cholangiopancreatography Pancreatitis

Introduction: Common bile duct stones (CBDS) are a common disease that can cause biliary complications, including cholangitis, obstructive jaundice, and biliary pancreatitis. Regardless of the presence or absence of symptoms, endoscopic removal of CBDS is generally recommended, but endoscopic retrograde cholangiopancreatography (ERCP) is a high-risk procedure with complications, such as post-ERCP pancreatitis (PEP). As few reports have addressed the risk of PEP by focusing on asymptomatic CBDS, the purpose of this study is to examine the incidence of PEP for asymptomatic CBDS.

Methods: This retrospective study included data from 302 patients with naive papilla who underwent therapeutic ERCP for CBDS between January 2012 and December 2019 at our hospital. Univariate and multivariate logistic regression models were used to investigate independent risk factors for PEP.

Results: Of the 302 patients, 32 were asymptomatic, and the remaining 270 were symptomatic. Five asymptomatic patients (15.6%) suffered from mild PEP, whereas 10 (3.7%) symptomatic patients suffered from PEP (9 were mild, and 1 was severe). Univariate analysis identified deep cannulation time more than 10 min, endoscopic papillary balloon dilation (EPBD), and asymptomatic CBDS as risk factors for PEP, whereas multivariate analysis revealed deep cannulation time more than 10 min (odds ratio (OR), 6.67; p < 0.001), EPBD (HR, 5.70; p < 0.001), and asymptomatic CBDS (HR, 5.49; p < 0.001) as independent risk factors for PEP.

Conclusions: A wait-and-see approach may be an option for the management of asymptomatic CBDS. EPBD may be avoided, especially in case of asymptomatic or if difficult for bile duct cannulation.

Extensive use of vasodilator agents and functional echocardiography to monitor extremely-low-birth-weight infants in Japan

National surveys were conducted in Japan to assess the current practices for circulatory management of extremely-low-birth-weight infants (ELBWIs) in acute phases. Approximately 80 and 100 institutions were surveyed in 2006 and 2011, respectively. Echocardiography was identified as an important diagnostic tool at 95% of the surveyed institutions. Furthermore, 74% of the institutions survey in 2011 used vasodilator agents. In 2011, the mean velocity of circumferential fiber shortening (mVcfc) and left ventricular end-systolic wall stress (ESWS) were used by 60% of the surveyed institutions to evaluate the relationship between afterload of the left ventricle and left ventricular contractility. Overall, the data collected from these national surveys clarified the current practices for circulatory management of ELBWIs in Japan, particularly the use of echocardiography and cardiovascular agents, including catecholamines and vasodilators.

Improvement of gemcitabine sensitivity of p53-mutated pancreatic cancer MiaPaCa-2 cells by RUNX2 depletion-mediated augmentation of TAp73-dependent cell death

Pancreatic cancer exhibits the worst prognostic outcome among human cancers. Recently, we have described that depletion of RUNX2 enhances gemcitabine (GEM) sensitivity of p53-deficient pancreatic cancer AsPC-1 cells through the activation of TAp63-mediated cell death pathway. These findings raised a question whether RUNX2 silencing could also improve GEM efficacy on pancreatic cancer cells bearing p53 mutation. In the present study, we have extended our study to p53-mutated pancreatic cancer MiaPaCa-2 cells. Based on our current results, MiaPaCa-2 cells were much more resistant to GEM as compared with p53-proficient pancreatic cancer SW1990 cells, and there existed a clear inverse relationship between the expression levels of TAp73 and RUNX2 in response to GEM. Forced expression of TAp73α in MiaPaCa-2 cells significantly promoted cell cycle arrest and/or cell death, indicating that a large amount of TAp73 might induce cell death even in the presence of mutant p53. Consistent with this notion, overexpression of TAp73α stimulated luciferase activity driven by p53/TAp73-target gene promoters in MiaPaCa-2 cells. Similar to AsPC-1 cells, small interfering RNA-mediated knockdown of RUNX2 remarkably enhanced GEM sensitivity of MiPaCa-2 cells. Under our experimental conditions, TAp73 further accumulated in RUNX2-depleted MiaPaCa-2 cells exposed to GEM relative to GEM-treated non-silencing control cells. As expected, silencing of p73 reduced GEM sensitivity of MiPaCa-2 cells. Moreover, GEM-mediated Tyr phosphorylation level of TAp73 was much more elevated in RUNX2-depleted MiaPaCa-2 cells. Collectively, our present findings strongly suggest that knockdown of RUNX2 contributes to a prominent enhancement of GEM sensitivity of p53-mutated pancreatic cancer cells through the activation of TAp73-mediated cell death pathway, and also provides a promising strategy for the treatment of patients with pancreatic cancer bearing p53 mutation.

[Primary arterial switch operation for complete transposition of the great arteries (type I) of a neonate weighing 1,378 g]

A 2-day-old female baby, delivered by emergent cesarean section at 35 weeks of gestational age with a birth weight of 1,378 g, was referred to our institute for intensive care of heart failure. By echocardiography and cardiac catheterization, the patient was diagnosed with isolated complete transposition of the great arteries. Primary arterial switch operation was performed at 13 days of age. No technical difficulty arose, imposed by the small size of cardiovascular structure. On the 5th postoperative day, surgical repair of intestinal perforation was performed. Convalescence thereafter was uneventful. She returned home on the 64th postoperative day with the body weight of 2,310 g. We conclude that primary arterial switch operation can be a feasible surgical option even in a neonate with very low birth weight.

Comparative genomic and expression analysis of group B1soxgenes in zebrafish indicates their diversification during vertebrate evolution

Group B1 Sox genes encode HMG domain transcription factors that play major roles in neural development. We have identified six zebrafish B1 sox genes, which include pan-vertebrate sox1a/b, sox2, and sox3, and also fish-specific sox19a/b. SOX19A/B proteins show a transcriptional activation potential that is similar to other B1 SOX proteins. The expression of sox19a and sox3 begins at approximately the 1,000-cell stage during embryogenesis and becomes confined to the future ectoderm by the shield stage. This is reminiscent of the epiblastic expression of Sox2 and/or Sox3 in amniotes. As development progresses, these six B1 sox genes display unique expression patterns that overlap distinctly from one region to another. sox19a expression is widespread in the early neuroectoderm, resembling pan-neural Sox2 expression in amniotes, whereas zebrafish sox2 shows anterior-restricted expression. Comparative genomics suggests that sox19a/b and mammalian Sox15 (group G) have an orthologous relationship and that the B1/G Sox genes arose from a common ancestral gene through two rounds of genome duplication. It seems likely, therefore, that each B1/G Sox gene has gained a distinct expression profile and function during vertebrate evolution.

Mutations affecting the formation of posterior lateral line system in Medaka, Oryzias latipes

We performed a systematic screen for mutations affecting the trajectory of axons visualized by immunohistochemical staining of Medaka embryos with anti-acetylated tubulin antibody. Among the mutations identified, yanagi (yan) and kazura (kaz) mutations caused specific defects in projection of the posterior lateral line (PLL) nerve. In yan and kaz mutant embryos, the PLL nerve main bundle was misrouted ventrally and dorsally or anteriorly. Medaka semaphorin3A, sdf1, and cxcr4 cDNA fragments were cloned to allow analysis of these mutants. There were no changes in semaphorin3A or sdf1 expression in mutant embryos, suggesting that the tissues expressing semaphorin3A or sdf1 that are involved in PLL nerve guidance are present in these mutant embryos. Double staining revealed that the mislocated PLL primordium and growth cone of the ectopically projected PLL nerve were always colocalized in both yan and kaz mutant embryos, suggesting that migration of PLL primordia and PLL nerve growth cones are not uncoupled in these mutants. Although homozygous yan larvae showed incomplete migration of the PLL primordium along the anteroposterior axis, ventral proneuromast migration was complete, suggesting that ventral migration of the proneuromast does not require the signaling affected in yan mutants. In addition to the PLL system, the distribution of primordial germ cells (PGCs) was also affected in both yan and kaz mutant embryos, indicating that yan and kaz genes are required for the migration of both PLL primordia and PGCs. Genetic linkage analysis indicated that kaz is linked to cxcr4, but yan is not linked to sdf1 or cxcr4. These mutations will provide genetic clues to investigate the molecular mechanism underlying formation of the PLL system.

A systematic genome-wide screen for mutations affecting organogenesis in Medaka, Oryzias latipes

A large-scale mutagenesis screen was performed in Medaka to identify genes acting in diverse developmental processes. Mutations were identified in homozygous F3 progeny derived from ENU-treated founder males. In addition to the morphological inspection of live embryos, other approaches were used to detect abnormalities in organogenesis and in specific cellular processes, including germ cell migration, nerve tract formation, sensory organ differentiation and DNA repair. Among 2031 embryonic lethal mutations identified, 312 causing defects in organogenesis were selected for further analyses. From these, 126 mutations were characterized genetically and assigned to 105 genes. The similarity of the development of Medaka and zebrafish facilitated the comparison of mutant phenotypes, which indicated that many mutations in Medaka cause unique phenotypes so far unrecorded in zebrafish. Even when mutations of the two fish species cause a similar phenotype such as one-eyed-pinhead or parachute, more genes were found in Medaka than in zebrafish that produced the same phenotype when mutated. These observations suggest that many Medaka mutants represent new genes and, therefore, are important complements to the collection of zebrafish mutants that have proven so valuable for exploring genomic function in development.

Mutations affecting thymus organogenesis in Medaka, Oryzias latipes

The thymus is an organ for T lymphocyte maturation and is indispensable for the establishment of a highly developed immune system in vertebrates. In order to genetically dissect thymus organogenesis, we carried out a large-scale mutagenesis screening for Medaka mutations affecting recombination activating gene 1 (rag1) expression in the developing thymus. We identified 24 mutations, defining at least 13 genes, which led to a marked reduction of rag1 expression in the thymus. As thymus development depends on pharyngeal arches, we classified those mutations into three classes according to the defects in the pharyngeal arches. Class 1 mutants had no or slight morphological abnormalities in the pharyngeal arches, implying that the mutations may include defects in such thymus-specific events as lymphocyte development and thymic epithelial cell maturation. Class 2 mutants had abnormally shaped pharyngeal arches. Class 3 mutants showed severely attenuated pharyngeal arch development. In Class 2 and Class 3 mutants, the defects in thymus development may be due to abnormal pharyngeal arch development. Those mutations are expected to be useful for identifying the molecular mechanisms underlying thymus organogenesis.

Mutations affecting early distribution of primordial germ cells in Medaka (Oryzias latipes) embryo

The development of germ cells has been intensively studied in Medaka (Oryzias latipes). We have undertaken a large-scale screen to identify mutations affecting the development of primordial germ cells (PGCs) in Medaka. Embryos derived from mutagenized founder fish were screened for an abnormal distribution or number of PGCs at embryonic stage 27 by RNA in situ hybridization for the Medaka vasa homologue (olvas). At this stage, PGCs coalesce into two bilateral vasa-expressing foci in the ventrolateral regions of the trunk after their migration and group organization. Nineteen mutations were identified from a screen corresponding to 450 mutagenized haploid genomes. Eleven of the mutations caused altered PGC distribution. Most of these alterations were associated with morphological abnormalities and could be grouped into four phenotypic classes: Class 1, PGCs dispersed into bilateral lines; Class 2, PGCs dispersed in a region more medial than that in Class 1; Class 3, PGCs scattered laterally and over the yolk sac area; and Class 4, PGCs clustered in a single median focus. Eight mutations caused a decrease in the number of PGCs. This decrease was observed in the offspring of heterozygous mothers, indicating the contribution of a maternal factor in determining PGC abundance. Taken together, these mutations should prove useful in identifying molecular mechanisms underlying the early PGC development and migration.

Genetic dissection of the formation of the forebrain in Medaka, Oryzias latipes

The forebrain, consisting of the telencephalon and diencephalon, is essential for processing sensory information. To genetically dissect formation of the forebrain in vertebrates, we carried out a systematic screen for mutations affecting morphogenesis of the forebrain in Medaka. Thirty-three mutations defining 25 genes affecting the morphological development of the forebrain were grouped into two classes. Class 1 mutants commonly showing a decrease in forebrain size, were further divided into subclasses 1A to 1D. Class 1A mutation (1 gene) caused an early defect evidenced by the lack of bf1 expression, Class 1B mutations (6 genes) patterning defects revealed by the aberrant expression of regional marker genes, Class 1C mutation (1 gene) a defect in a later stage, and Class 1D (3 genes) a midline defect analogous to the zebrafish one-eyed pinhead mutation. Class 2 mutations caused morphological abnormalities in the forebrain without considerably affecting its size, Class 2A mutations (6 genes) caused abnormalities in the development of the ventricle, Class 2B mutations (2 genes) severely affected the anterior commissure, and Class 2C (6 genes) mutations resulted in a unique forebrain morphology. Many of these mutants showed the compromised sonic hedgehog expression in the zona-limitans-intrathalamica (zli), arguing for the importance of this structure as a secondary signaling center. These mutants should provide important clues to the elucidation of the molecular mechanisms underlying forebrain development, and shed new light on phylogenically conserved and divergent functions in the developmental process.

Mutations affecting retinotectal axonal pathfinding in Medaka, Oryzias latipes

We screened for mutations affecting retinotectal axonal projection in Medaka, Oryzias latipes. In wild-type Medaka embryos, all the axons of retinal ganglion cells (RGCs) project to the contralateral tectum, such that the topological relationship of the retinal field is maintained. We labeled RGC axons using DiI/DiO at the nasodorsal and temporoventral positions of the retina, and screened for mutations affecting the pattern of stereotypic projections to the tectum. By screening 184 mutagenized haploid genomes, seven mutations in five genes causing defects in axonal pathfinding were identified, whereas mutations affecting the topographic projection of RGC axons were not found. The mutants were grouped into two classes according to their phenotypes. In mutants of Class I, a subpopulation of the RGC axons branched out either immediately after leaving the eye or after reaching the midline, and this axonal subpopulation projected to the ipsilateral tectum. In mutants of Class II, subpopulations of RGC axons branched out after crossing the midline and projected aberrantly. These mutants will provide clues to understanding the functions of genes essential for axonal pathfinding, which may be conserved or partly divergent among vertebrates.

Mutations affecting gonadal development in Medaka, Oryzias latipes

A gonad is formed from germ cells and somatic mesodermal cells through their interactions. Its development is coupled with the determination and differentiation of the sex and sex-associated traits. We carried out a large-scale screening of Medaka mutants in which gonadal development is affected. Screening was performed on larvae at 8 days posthatching for abnormal abundance and/or distribution of germ cells detected by the in situ hybridization for olvas (Medaka vasa). We describe here 16 mutants of 13 genes, which are classified into four groups. Group 1, consisting of four mutants of three genes kon, tot) characterised by an increase in germ cell number. An adult tot homozygote fish has the characteristic feature of possessing hypertrophic gonads filled with immature oocytes. Group 2, represented by a single gene (zen) mutant characterized by a gradual loss of germ cells. Group 3, consisting of four mutants of distinct genes (eko, eki, sht, ano) showing irregular clustering of germ cells. Group 4, consisting of seven mutants of five genes (arr, hyo, mzr, hdr, fbk) showing fragmented clusters of germ cells. In some mutants belonging to Groups 1, 3 and 4, the expression level of ftz-f1 (sf-1/Ad4BP) in gonadal somatic cells significantly decreased, suggesting that interaction between somatic and germ cells is affected.

Identification of radiation-sensitive mutants in the Medaka, Oryzias latipes

We screened populations of N-ethyl-N-nitrosourea (ENU)-mutagenized Medaka, (Oryzias latipes) for radiation-sensitive mutants to investigate the mechanism of genome stability induced by ionizing radiation in developing embryos. F3 embryos derived from male founders that were homozygous for induced the mutations were irradiated with gamma-rays at the organogenesis stage (48hpf) at a dose that did not cause malformation in wild-type embryos. We screened 2130 F2 pairs and identified three types of mutants with high incidence of radiation-induced curly tailed (ric) malformations using a low dose of irradiation. The homozygous strain from one of these mutants, ric1, which is highly fertile and easy to breed, was established and characterized related to gamma-irradiation response. The ric1 strain also showed higher incidence of malformation and lower hatchability compared to the wild-type CAB strain after gamma-irradiation at the morula and pre-early gastrula stages. We found that the decrease in hatching success after gamma-irradiation, depends on the maternal genotype at the ric1 locus. Terminal deoxynucleotidyl transferase-mediated deoxy-UTP nick end-labeling assays showed a high frequency of apoptosis in the ric1 embryos immediately after gamma-irradiation at the pre-early gastrula stage but apoptotic cells were not observed before midblastula transition (MBT). The neutral comet assay revealed that the ric1 mutant has a defect in the rapid repair of DNA double-strand breaks induced by gamma-rays. These results suggest that RIC1 is involved in the DNA double strand break repair in embryos from morula to organogenesis stages, and unrepaired DNA double strand breaks in ric1 trigger apoptosis after MBT. These results support the use of the ric1 strain for investigating various biological consequences of DNA double strand breaks in vivo and for sensitive monitoring of genotoxicity related to low dose radiation.

Mutations affecting retina development in Medaka

In a large scale mutagenesis screen of Medaka we identified 60 recessive zygotic mutations that affect retina development. Based on the onset and type of phenotypic abnormalities, the mutants were grouped into five categories: the first includes 11 mutants that are affected in neural plate and optic vesicle formation. The second group comprises 15 mutants that are impaired in optic vesicle growth. The third group includes 18 mutants that are affected in optic cup development. The fourth group contains 13 mutants with defects in retinal differentiation. 12 of these have smaller eyes, whereas one mutation results in enlarged eyes. The fifth group consists of three mutants with defects in retinal pigmentation. The collection of mutants will be used to address the molecular genetic mechanisms underlying vertebrate eye formation.

Mutations affecting liver development and function in Medaka, Oryzias latipes, screened by multiple criteria

We report here mutations affecting various aspects of liver development and function identified by multiple assays in a systematic mutagenesis screen in Medaka. The 22 identified recessive mutations assigned to 19 complementation groups fell into five phenotypic groups. Group 1, showing defective liver morphogenesis, comprises mutations in four genes, which may be involved in the regulation of growth or patterning of the gut endoderm. Group 2 comprises mutations in three genes that affect the laterality of the liver; in kendama mutants of this group, the laterality of the heart and liver is uncoupled and randomized. Group 3 includes mutations in three genes altering bile color, indicative of defects in hemoglobin-bilirubin metabolism and globin synthesis. Group 4 consists of mutations in three genes, characterized by a decrease in the accumulation of fluorescent metabolite of a phospholipase A(2) substrate, PED6, in the gall bladder. Lipid metabolism or the transport of lipid metabolites may be affected by these mutations. Mutations in Groups 3 and 4 may provide animal models for relevant human diseases. Group 5 mutations in six genes affect the formation of endoderm, endodermal rods and hepatic bud from which the liver develops. These Medaka mutations, identified by morphological and metabolite marker screens, should provide clues to understanding molecular mechanisms underlying formation of a functional liver.

Mutations affecting somite formation in the Medaka (Oryzias latipes)

The metameric structure of the vertebrate trunk is generated by repeated formation of somites from the unsegmented presomitic mesoderm (PSM). We report the initial characterization of nine different mutants affecting segmentation that were isolated in a large-scale mutagenesis screen in Medaka (Oryzias latipes). Four mutants were identified that show a complete or partial absence of somites or somite boundaries. In addition, five mutations were found that cause fused somites or somites with irregular sizes and shapes. In situ hybridization analysis using specific markers involved in the segmentation clock and antero-posterior (A-P) polarity of somites revealed that the nine mutants can be compiled into two groups. In group 1, mutants exhibit defects in tailbud formation and PSM prepatterning, whereas A-P identity in the somites is defective in group 2 mutants. Three mutants (planlos, pll; schnelles ende, sne; samidare, sam) have characteristic phenotypes that are similar to those in zebrafish mutants affected in the Delta/Notch signaling pathway. The majority of mutants, however, exhibit somitic phenotypes distinct from those found in zebrafish, such as individually fused somites and irregular somite sizes. Thus, these Medaka mutants can be expected to provide clues to uncovering novel components essential for somitogenesis.

Congenital pulmonary-systemic collateral vein without obstructed left atrial egress is associated with conotruncal anomalies

We present a case of congenital pulmonary systemic collateral vein associated with truncus arteriosus. Pulmonary systemic collateral vein with nonobstructed left atrial egress is different from those with obstructed left atrial egress in that it is functionally redundant. Including this case, 8 patients among 33 reported cases with pulmonary systemic collateral veins have had nonobstructed left atrial egress. Association with conotruncal anomalies in 4 of these 8 patients, as well as the reported finding that neural crest cells are distributed not only in the conotruncus but also in the cardinal vein, indicates that neural crest cells play roles in remodeling of the systemic venous system.

Analysis of Wnt8 for neural posteriorizing factor by identifying Frizzled 8c and Frizzled 9 as functional receptors for Wnt8

The dorsal ectoderm of vertebrate gastrula is first specified into anterior fate by an activation signal and posteriorized by a graded transforming signal, leading to the formation of forebrain, midbrain, hindbrain and spinal cord along the anteroposterior (A-P) axis. Transplanted non-axial mesoderm rather than axial mesoderm has an ability to transform prospective anterior neural tissue into more posterior fates in zebrafish. Wnt8 is a secreted factor that is expressed in non-axial mesoderm. To investigate whether Wnt8 is the neural posteriorizing factor that acts upon neuroectoderm, we first assigned Frizzled 8c and Frizzled 9 to be functional receptors for Wnt8. We then, transplanted non-axial mesoderm into the embryos in which Wnt8 signaling is cell-autonomously blocked by the dominant-negative form of Wnt8 receptors. Non-axial mesodermal transplants in embryos in which Wnt8 signaling is cell-autonomously blocked induced the posterior neural markers as efficiently as in wild-type embryos, suggesting that Wnt8 signaling is not required in neuroectoderm for posteriorization by non-axial mesoderm. Furthermore, Wnt8 signaling, detected by nuclear localization of beta-catenin, was not activated in the posterior neuroectoderm but confined in marginal non-axial mesoderm. Finally, ubiquitous over-expression of Wnt8 does not expand neural ectoderm of posterior character in the absence of mesoderm or Nodal-dependent co-factors. We thus conclude that other factors from non-axial mesoderm may be required for patterning neuroectoderm along the A-P axis.

An expression pattern screen for genes involved in the induction of the posterior nervous system of zebrafish

The posterior nervous system, including the hindbrain and the spinal cord, has been shown to be formed by the transformation of neural plate of anterior character by signals derived from non-axial mesoderm. Although secreted factors, such as fibroblast growth factors (FGFs), Wnts, retinoic acid (RA) and Nodal, have been proposed to be the posteriorizing factors, the mechanism how neural tissue of posterior character is induced and subsequently specified along the anteroposterior axis remains elusive. To identify intercellular signaling molecules responsible for posteriorization of the neural plate as well as to find molecules induced intracellularly by the posteriorizing signal in the caudal neural plate, we screened by in situ hybridization for genes specifically expressed in posterior tissues, including the posterior neural plate and non-axial mesoderm when posteriorization of the neural plate takes place. From a subtracted library differentiating anterior versus posterior neural plate, 420 cDNA clones were tested, out of which 76 cDNA fragments showed expression restricted to the posterior tissue. These clones turned out to represent 32 different genes, including one novel secreted factor and one transmembrane protein. Seven genes were induced by non-axial mesodermal implants and bFGF beads, suggesting that these are among the early-response genes of the posteriorizing signal. Thus, our approach employing cDNA subtraction and subsequent expression pattern screening allows us to clone candidate genes involved in a novel signaling pathway contributing to the formation of the posterior nervous system.

Identification of early-responsive genes associated with the hypersensitive response to tobacco mosaic virus and characterization of a WRKY-type transcription factor in tobacco plants

In order to identify genes that are involved in the defense reaction against pathogen attack, we screened for examples that are regulated during the hypersensitive response (HR) to infection by tobacco mosaic virus (TMV) of tobacco ( Nicotiana tabacum cv. Xanthi nc) carrying the N gene, which confers resistance to TMV. Among seven genes initially identified by fluorescent differential display, one clone was further characterized because its transcripts accumulated rapidly and transiently after the onset of HR. Its full-length cDNA of 1346 bp encoded a polypeptide consisting of 258 amino acids. The deduced protein contained a single WRKY domain, a Cys(2)His(2) zinc-finger motif and a leucine-zipper motif, showing high similarity to WIZZ, a member of the family of WRKY transcription factors in tobacco. The gene was thus designated TIZZ. A GFP-TIZZ fusion protein was found to localize to the nucleus upon introduction into epidermal cells of onion. Bacterially expressed TIZZ was able to bind to the W-box (TTGAC) element that is recognized by other WRKY proteins, but transactivation assays showed it to be unable to activate reporter gene expression by itself. TIZZ transcripts were induced in TMV-infected nahG transgenic tobacco plants, in which salicylic acid fails to accumulate. Neither exogenously applied salicylic acid nor mechanical wounding induced TIZZ transcript accumulation. These results indicate the presence of salicylic acid-independent pathways for HR signal transduction, in which a novel type of WRKY protein(s) may play a critical role for the activation of defense.

[A case of Down syndrome with ventricular septal defect and hemodynamical Eisenmenger syndrome]

A 10 month-old infant with Down syndrome having ventricular septal defect and pulmonary hypertension performed cardiac catheterization, which resulted in a slight increase in the pulmonary vascular resistance from 10.8 to 11.3 unit.m2. Lung biopsy findings showed at most an early grade 2 Heath-Edwards classification, and an index of pulmonary vascular disease of 1.1, both of which indicated operability for total correction. He underwent surgical correction and the pulmonary arterial pressure significantly decrease. Although he suffered chylothorax in 5th postoperative day, he did not developed pulmonary hypertension crisis.

Clinicopathological analysis of premature infants treated with artificial surfactant

OBJECTIVE

Our aim was to obtain new information about the relationship between infant responses to surfactant replacement therapy and histopathological changes in vital organs.

STUDY DESIGN

To accomplish this, the autopsy findings and clinical backgrounds of 41 very low birth weight infants (gestational week 25.6 +/- 2.3; birth weight 806.4 +/- 251.6g) who had died after receiving surfactant replacement therapy were reviewed, and those who responded to therapy were compared with those who did not. Responders were infants in whom the required FiO(2) declined by > 20% or mean airway pressure declined by > 20% within six hours of instilling surfactant (n=18); non-responders were infants who did not meet those criteria (n=23).

RESULT

Gestational age, birth weight and time at treatment were similar in responders and non-responders, but survival was significantly longer in responders. The incidences of hyaline membrane disease, pulmonary interstitial emphysema, hemorrhagic necrosis and parenchymal degeneration of the liver and kidney were all higher in non-responders, whereas the incidences of bronchopulmonary dysplasia and pneumonia were higher in responders. Prior to treatment, acidosis and hypothermia were significantly more severe in non-responders, and perinatal complications, such as fetal distress and intrauterine infection, were observed more often in non-responders. Substantial degradation of vital organs had already occurred during the early post-natal or intrauterine life of the non-responders, which would be expected to interfere with the clinical response to instilled surfactant.

CONCLUSION

It is anticipated that in the future improved monitoring of immature fetuses will be indispensable to improve intrauterine fetal management and to achieve better control over the timing and mode of delivery.

Zebrafish mutations in Gli-mediated hedgehog signaling lead to lens transdifferentiation from the adenohypophysis anlage

It is known that the earliest lens marker delta-crystallin is expressed abundantly in Rathke's pouch of the chicken, suggesting a close relationship between the cell states of the adenohypophysis (pituitary) anlage and the early lens. We show here that the zebrafish midline mutants you-too (yot) and iguana (igu) develop lenses from the adenohypophysis anlage. The early adenohypophysis anlage of normal zebrafish expresses lim3 and six3 but in yot(ty119) mutants the anterior part of the anlage lacks lim3 expression, and instead produces a crystallin-expressing cell population which develops into a large lens structure expressing beta and gamma-crystallins, but is not associated with retina tissues. Among the zebrafish mutants with midline defects, midline lenses were observed in two mutant alleles of yot and an allele of igu, but not in other mutants (syu, con, smh, dtr, uml, spi and lok). Two yot mutant alleles with midline lenses likely encode dominant negative forms of the Gli2 protein which will interfere with transcriptional activation by other Gli proteins. The observation argues that overall inhibition of Shh-Gli signaling leads the adenohypophysis anlage to transdifferentiate into lens.

Loss of cadherin-11 adhesion receptor enhances plastic changes in hippocampal synapses and modifies behavioral responses

Cadherins organize symmetrical junctions between the pre- and postsynaptic membranes in central synapses. One of them, cadherin-11 (cad11), is expressed in the limbic system of the brain, most strongly in the hippocampus. Immunohistochemical studies of the hippocampus showed that cad11 proteins were densely distributed in its synaptic neuropil zones; in cultured hippocampal neurons, their distribution often overlapped with that of synaptophysin, and also occasionally with that of GluR1 at spines. To assess the role of cad11 in synaptic formation and/or function, we analyzed brains of cad11-deficient mice. In these mice, long-term potentiation (LTP) in the CA1 region of the hippocampus was, unexpectedly, enhanced; and the level of LTP saturation was increased. In behavioral tests, the mutant mice showed reduced fear- or anxiety-related responses. These results suggest that the cad11-mediated junctions may modulate synaptic efficacy, confining its dynamic changes to a limited range, or these junctions are required for normal development of synaptic organization in the hippocampus.

Expressed sequence tags from immature female sexual organ of a liverwort, Marchantia polymorpha

A total of 970 expressed sequence tag (EST) clones were generated from immature female sexual organ of a liverwort, Marchantia polymorpha. The 376 ESTs resulted in 123 redundant groups, thus the total number of unique sequences in the EST set was 717. Database search by BLAST algorithm showed that 302 of the unique sequences shared significant similarities to known nucleotide or amino acid sequences. Six unique sequences showed significant similarities to genes that are involved in flower development and sexual reproduction, such as cynarase, fimbriata-associated protein and S-receptor kinase genes. The remaining unique 415 sequences have no significant similarity with any database-registered genes or proteins. The redundant 123 ESTs implied the presence of gene families and abundant transcripts of unknown identity. Analyses of the coding sequences of 61 unique sequences, which contained no ambiguous bases in the predicted coding regions, highly homologous to known sequences at the amino acid level with a similarity score greater than 400, and with stop codons at similar positions as their possible orthologues, indicated the presence of biased codon usage and higher GC content within the coding sequences (50.4%) than that within 3' flanking sequences (41.9%).

AFP-producing squamous cell carcinoma of the lung in an adolescent

We report a case of primary lung cancer in a 16-year-old boy. A histologic diagnosis of squamous cell carcinoma was made by bronchoscopic biopsy before surgery. The serum alphafetoprotein (AFP) level was markedly elevated at 193 ng/dl. Preoperative and postoperative evaluation revealed no evidence of scrotal mass. We performed right pneumonectomy with combined resection of the invaded portion of the left atrium under extracorporeal circulation. Despite the rapid improvement in the patient's general condition after surgery, the AFP level continued to increase without a transient decrease and reached 3160 ng/ml on the 23rd postoperative day. When the patient was readmitted because of dyspnea and headache on the 36th postoperative day, hypercalcemia of 13.9 mg/dl was noted, and this was resistant to subsequent treatment. The patient died on the 46th postoperative day.

Blood flow velocities in the cerebral arteries and descending aorta in small-for-dates infants

Resistive indices (RI) in the anterior cerebral artery (ACA), basilar artery (BA), middle cerebral artery (MCA) and descending aorta (DA) were obtained in 15 small-for-dates (SFD) infants who were, growth retarded because of maternal pregnancy-induced hypertension and in 20 appropriate-for-dates (AFD) infants matched for gestational age between 24 h and 48 h after birth. The RIs in the MCA, ACA and BA were significantly lower, while the RI in the DA was significantly higher, in the SFD infants than in the AFD infants. These changes in RIs in the SFD infants might be similar to the "brain sparing" effect as reported in growth-retarded fetuses.

[Incidence and causes of neonatal seizures in the last 10 years (1981-1990)]

We report the incidence of neonatal seizures in the last 10 years. Between 1981-1990, 28,925 infants were born in the Japanese Red Cross Medical Center. Very low-birth-weight infants (< 1,500 g) were excluded in this study. Seizures were identified in 67 infants (0.23%) during the first 7 days of life. Seizures occurred more frequently in low-birth-weight infants (1,500-2,499 g) than in normal-birth-weight infants (> 2,499 g). Fifty-one infants (0.19%) of 27,276 normal-birth-weight infants and 16 (0.97%) of 1,649 low-birth-weight infants developed seizures. The frequency of seizures was 0.25% during the first 5 years and 0.20% during the second 5 years. In low-birth-weight group, the frequency of seizures decreased form 1.49% to 0.48% during the 5-year periods, and seizures due to post asphyxial hypoxic-ischemic encephalopathy also decreased from 0.14% to 0.06%. The decreased incidence in neonatal seizures during the last 10 years was probably achieved by the progress in intervention of low-birth-weight infants in NICU and by the obstetrical prevention of intrapartum asphyxia.

Development of hepatocellular carcinoma in a man with auto-immune chronic active hepatitis

A 57 year old man with auto-immune chronic active hepatitis, regularly treated with immunosuppressive therapy, had hepatocellular carcinoma (HCC) 10 years after diagnosis of the hepatitis. Assays of the hepatitis C virus antibodies against capsid and non-structural proteins revealed seronegativity in serial serum samples of this patient stored in the previous 10 years during follow up. The seronegative hepatitis C antibodies excluded hepatitis C virus as the cause of the HCC. The occurrence of HCC in this case suggests the necessity of surveillance for early detection of liver cancer in patients with auto-immune chronic active hepatitis undergoing long-term immunosuppressive therapy.

[Clinical evaluation of imipenem/cilastatin sodium against severe infections complicating hematological disorders and solid tumors]

Imipenem/cilastatin sodium (IPM/CS) was administered to a total of 67 patients with severe infections complicating hematological disorders and solid tumors. Fifty patients are included in the present analysis of efficacy and 64 in that of safety. 1. Out of 31 patients with hematological disorders, responses were excellent in 10 patients, good in 10 patients, and the efficacy rate was 64.5%. Out of 19 patients with solid tumors, responses were excellent in 8 patients, good in 8 patients and the efficacy rate was 84.2%. 2. For patients whose responses to other antibiotics had been poor, the efficacy rate was 59.3% in the group with hematological disorders and 62.5% in the group with solid tumors. 3. The relationship between the neutrophil count and efficacy was studied in the patients with hematological disorders. The efficacy rate for 8 patients whose neutrophil counts were 500/mm3 or less was 75.0%. 4. For the patients with hematological disorders, the efficacy rate for patients from whom causative organisms were isolated was 70.0% and that for patients for whom they were unknown was 61.9%. 5. Adverse reactions were observed in 3 patients and abnormal laboratory test results in 2 patients. However, they were mild and disappeared after discontinuation of this drug. From these results, IPM/CS is considered to be a useful antibiotic for the treatment of severe infections complicating hematological disorders and solid tumors.

A case of Caroli's disease with hepatolithiasis, choledocholithiasis, and cholangiocarcinoma

A 48-year-old woman with Caroli's disease accompanied by hepatolithiasis, choledocholithiasis, and cholangiocarcinoma is reported. Magnetic resonance imaging was useful for the diagnosis of the cholangiocarcinoma. The relationship between cholangiocarcinoma and hepatolithiasis, choledocholithiasis, and chronic cholangitis in Caroli's disease is discussed.

Cerebral blood flow velocities in the anterior cerebral arteries and basilar artery in hydrocephalus before and after treatment

We studied Pourcelot's index (PI), which shows cerebral vascular resistance, in the anterior cerebral arteries and basilar artery, and the PI ratio (Pourcelot's index in the anterior cerebral artery/Pourcelot's index in the basilar artery) in 11 measurements of hydrocephalus. The mean values of PI in the anterior cerebral artery, basilar artery, and the PI ratio before treatment were significantly higher than those after treatment and those in normal infants. Before treatment, the mean PI in the anterior cerebral arteries was significantly higher than the mean PI in the basilar artery. All PI ratios increased to 1.00 or more. After treatment and in normal infants, the mean PI in the anterior cerebral arteries was significantly lower than the mean PI in the basilar artery. All PI ratios decreased to less than 1.00. We believe that the PI ratio is useful to evaluate the need or effect of treatment in hydrocephalus.

A case of Dandy-Walker malformation associated with occipital meningocele, microphthalmia, and cleft palate

We present a case of Dandy-Walker malformation associated with occipital meningocele, microphthalmia, and cleft palate. Small numbers of cases of Dandy-Walker malformation with occipital meningocele have been described in the literature, but to our knowledge, non of these also had microphthalmia or cleft palate. This association suggests that time of intrauterine origin of Dandy-Walker syndrome was in the sixth or seventh embryonic week. In the diagnosis, both CT cisternography and direct neurosonography over the occipital meningocele was useful for the demonstration of a posterior fossa cyst which communicated with the fourth ventricle and the occipital meningocele.

Treatment of chronic non-A non-B hepatitis with human interferon beta: a preliminary study

Twenty-four patients with chronic non-A non-B hepatitis were randomly assigned to receive either human fibroblast interferon (HuIFN-beta) at doses of 1 or 3 million international units (MIU) per day for 4 or 12 weeks (12 patients) or to receive no therapy (12 patients), and were then compared with 5 patients with chronic type B hepatitis who were treated with HuIFN-beta. Elevated serum aminotransferase levels decreased more rapidly during the treatment of chronic non-A non-B hepatitis than of chronic hepatitis B. Variations in serum aminotransferases were not observed in any of the untreated chronic non-A non-B hepatitis patients. In 3 of the 9 patients with chronic non-A non-B hepatitis who responded to HuIFN-beta therapy, serum aminotransferase levels remained normal 15, 21 and 31 months after therapy was discontinued; liver biopsy specimens obtained after therapy from 2 patients showed marked histological improvement. In the six other patients aminotransferase activity levels became again elevated following cessation of interferon therapy. No response to HuIFN-beta was seen in the remaining 3 patients with chronic non-A non-B hepatitis.

Serial assay for IGM anti-HBc in patients with anti-HBe-positive chronic hepatitis and its significance for long-term prognosis

Serial assays for immunoglobulin M antibody to hepatitis B core antigen (IgM anti-HBc) were performed in 51 patients with antibody to hepatitis B e antigen (anti-HBe) in their sera. IgM anti-HBc was detected periodically and persistently in 8 (53%) of 15 patients with chronic hepatitis whose serum glutamic pyruvic transaminase (GPT) levels were elevated and was not detected in 36 patients with normal serum GPT levels. Antibody to delta agent was not detected in any of the patients. Of the eight patients positive for IgM anti-HBc, four had a high titer of IgM anti-HBc and either developed liver cirrhosis (three cases) or died due to massive hepatic necrosis (one case); the other four showed a low level of IgM anti-HBc and either recovered (two cases) or developed chronic persistent hepatitis (two cases). Of seven patients negative for IgM anti-Hbc, two had a fatty liver, and five, who had a history of blood transfusion, had chronic hepatitis. Thus, even though anti-HBe may be present, if the titer of IgM anti-HBc is high, the histological activity can be expected to increase, and the prognosis will be poor. If the titer of IgM anti-HBc is low, the histological activity may be expected to decrease, and the prognosis may be good. In patients with abnormally high serum GPT but without IgM anti-HBc, another type of hepatitis or a secondary form of liver disease should be considered.

Possible infectious causes in 651 patients with acute viral hepatitis during a 10-year period (1976-1985)

Six hundred and fifty-one patients with acute viral hepatitis were identified serologically between January 1976 and December 1985. Of these, 109 (17%) had hepatitis A, 135 (21%) had hepatitis B, and 407 (62%) had hepatitis non-A, non-B. The possible infectious causes for acquisition of viral hepatitis occurring within 6 months before the onset of hepatitis were analysed. Approximately 80% of cases of hepatitis A and 70% of hepatitis B had no known risk factor, while in 67% of cases of hepatitis non-A, non-B possible risk factors for infection were documented. Infectious causes for hepatitis A were ingestion of raw shellfish (11%) and previous familial contact with patients with hepatitis A (10%). For hepatitis B, risk factors included medicare (24%), such as transfusion, surgical operation, accidental needle stick and acupuncture, and sexual contact (6%). For hepatitis non-A, non-B, the most important infectious cause was medical procedures (65%). The numbers of hospital employees were 2 (2%) with hepatitis A, 15 (11%) with hepatitis B and 14 (3%) with hepatitis non-A, non-B. These data suggest that hepatitis non-A, non-B can be a kind of nosocomial disease.

Significance of IgM antibody to hepatitis B core antigen for the differential diagnosis of acute and chronic hepatitis B virus infection and for the evaluation of the inflammatory activity of type B chronic liver diseases

IgM antibody to hepatitis B core antigen (anti-HBc) was assayed using a commercial kit in acute and chronic hepatitis B virus (HBV) infection and evaluated for its diagnostic and clinical significance. IgM anti-HBc was positive in all of 21 cases with type B acute hepatitis in the acute phase, and was also detected in 5 of 20 cases with type B chronic persistent hepatitis, in 4 of 20 patients with type B chronic active hepatitis and in one of 10 with type B liver cirrhosis. The absence of this marker was noted in all of 20 asymptomatic hepatitis B surface antigen (HBsAg) carriers and in 50 with HBsAg-negative patients with liver disease and in 200 healthy blood donors. The cut-off index of IgM anti-HBc was greater than 2.0 in all serum samples obtained in the acute phase of type B acute hepatitis, but was below 2.0 in type B chronic liver disease. A close relationship was found between the presence of IgM anti-HBc and the degree of inflammatory activity in patients with HBsAg-positive chronic liver disease. These data show that examination of IgM anti-HBc is useful in distingushing type B acute hepatitis from type B chronic liver disease, and also in evaluating the severity of disease in type B chronic liver disease.

Evolution of HBeAg/anti-HBe status and its relationship to clinical and histological outcome in chronic HBV carriers in childhood

Fifty-five Japanese HBV carriers under 15 yr of age were followed for 12 months or longer, during which time we investigated the evolution of HBeAg/anti-HBe status and clinical and histological aspects of the liver disease. Of 45 cases positive for HBeAg at the initial examination, 34 remained positive for HBeAg during the follow-up periods, while the remaining 11 lost HBeAg and eight of these seroconverted to anti-HBe. At the final observation, HBeAg positivity in serum was found in as many as approximately 90% of the HBV carriers under 6 yr, but had fallen to 48% in carriers between 12 and 15 yr. The serum transaminase values in 11 cases who lost HBeAg were abnormally elevated for variable periods, but eventually returned to normal. In six of these 11 who had liver dysfunctions, liver biopsy was performed during the HBeAg positive phase or shortly after the disappearance of HBeAg. The histologies of liver were chronic persistent hepatitis in two cases and chronic active hepatitis in four. Repeat liver biopsies of two cases with chronic active hepatitis at the first examination showed nonspecific reactive hepatitis 2 and 4 yr after seroconversion or disappearance of HBeAg. These results indicate that HBeAg-positive HBV carriers with overt liver dysfunctions in childhood are prone to lose HBeAg or to seroconvert to anti-HBe, followed by a marked histological regression, and therefore that special antiviral therapy is probably unnecessary.

Experimental infection of Bordetella bronchiseptica to rabbits

Infectivity and pathogenicity of Bordetella bronchiseptica to rabbits were investigated by intranasal inoculation of the organism to suckling and young animals. Results are summarized as follows. 1. By inoculation of 5 X 10(4) and 10(6) organisms, the infection developed in 60% and 100% of young rabbits, respectively. 2. In young rabbits, the growth of the organism was evident in the trachea within 5 days after inoculation and in the lung on the 10th day. The organism began to disappear from the lung and trachea of some animals from the 40th day after inoculation, but remained in the external nares and nasal cavity of all animals even on the 90th day. Neither clinical sign nor pneumonic lesion was observed in any stages of the infection. 3. Pneumonic lesions and serous nasal secretion were found in all suckling rabbits by inoculation of 5 X 10(6) organisms, but no fatal case was detected.