Role of CEACAM1 isoforms in an in vivo model of mammary morphogenesis: mutational analysis of the cytoplasmic domain of CEACAM1-4S reveals key residues involved in lumen formation

CEACAM1 (carcinoembryonic antigen-related cell adhesion molecule 1) is a type I transmembrane glycoprotein expressed in epithelial cells with three or four extracellular domains (ECDs) and either long or short cytoplasmic domain isoforms. We have previously shown that the four extracellular domains, short cytoplasmic domain isoform, CEACAM1-4S, plays an essential role in lumen formation in an in vitro model of mammary morphogenesis. In this study, we transfected MCF-7 cells with either the long or short cytoplasmic domain isoforms of CEACAM1, and grew the cells in humanized mammary mouse fat pads in NOD/SCID mice. In this in vivo model, only the long cytoplasmic domain isoform, CEACAM1-4L, formed glands with lumen. On the basis of other studies that revealed phosphorylation of key Thr and Ser residues in the short cytoplasmic domain, we introduced phosphorylation mimic (for example, Thr or Ser to Asp) or null (Thr or Ser to Ala) mutations into the cytoplasmic domain of CEACAM1-4S and tested them in the in vivo model. Mutation of either Thr or Ser to Asp or the double mutant Thr+Ser to Asp, but not the null mutants, induced gland formation with a central lumen-containing apoptotic cells. Moreover, the phosphorylation mimic mutants of CEACAM1-4S induced downregulation of beta1-integrin, overexpression of beta2-integrin, inhibited phosphorylation of focal adhesion kinase (pTyr-397) and resulted in myofibroblast differentiation as characterized by expression of vimentin, alpha-smooth muscle actin and beta2-integrin, as well as the production of abundant extracellular matrix.

L3/Lhx8 is a pivotal factor for cholinergic differentiation of murine embryonic stem cells

L3/Lhx8 is a member of the LIM-homeobox gene family. Previously, we demonstrated that L3/Lhx8-null mice specifically lacked cholinergic neurons in the basal forebrain. In the present study, we conditionally suppressed L3/Lhx8 function during retinoic acid-induced neural differentiation of a murine embryonic stem (ES) cell line using an L3/Lhx8-targeted small interfering RNA (siRNA) produced by an H1.2 promoter-driven vector. Our culture conditions induced efficient differentiation of the ES cells into neurons and astrocytes, but far less efficient differentiation into oligodendrocytes. Suppression of L3/Lhx8 expression by siRNA led to a dramatic decrease in the number of cells positive for the cholinergic marker ChAT, and overexpression of L3/Lhx8 recovered this effect. However, no significant changes were observed in the number of Tuj1+ neurons and GABA+ cells. These results strongly suggest that L3/Lhx8 is a key factor in the cholinergic differentiation of murine ES cells and is involved in basal forebrain development.

Current role of liver transplantation for methylmalonic acidemia: a review of the literature

To evaluate the current role of liver transplantation (LT) for methylmalonic acidemia (MMA), we reviewed the literature on outcomes of this treatment, and describe three of our own cases of living-donor liver transplantation (LDLT). The total number of LT cases identified was 18. Transplantation mode was deceased donor LT in 12, including five combined liver-kidney transplantations (CLKT) from deceased donors, and LDLT in six. Three hospital mortalities were noted, because of metabolic decompensation, sepsis and aspergillosis. Although mean postoperative serum MMA level decreased to 13.8% +/- 9.2% (range 1.25-26.1%) of preoperative levels, four patients (22.2%) had renal insufficiency after isolated LT and three (16.7%) had postoperative neurological disability. Continuing metabolic damage to the kidney and brain may occur even after successful LT. Further evaluation is required to determine the long-term suitability of this treatment modality.

Genetic variance modifies apoptosis susceptibility in mature oocytes via alterations in DNA repair capacity and mitochondrial ultrastructure

Although the identification of specific genes that regulate apoptosis has been a topic of intense study, little is known of the role that background genetic variance plays in modulating cell death. Using germ cells from inbred mouse strains, we found that apoptosis in mature (metaphase II) oocytes is affected by genetic background through at least two different mechanisms. The first, manifested in AKR/J mice, results in genomic instability. This is reflected by numerous DNA double-strand breaks in freshly isolated oocytes, causing a high apoptosis susceptibility and impaired embryonic development following fertilization. Microinjection of Rad51 reduces DNA damage, suppresses apoptosis and improves embryonic development. The second, manifested in FVB mice, results in dramatic dimorphisms in mitochondrial ultrastructure. This is correlated with cytochrome c release and a high apoptosis susceptibility, the latter of which is suppressed by pyruvate treatment, Smac/DIABLO deficiency, or microinjection of 'normal' mitochondria. Therefore, background genetic variance can profoundly affect apoptosis in female germ cells by disrupting both genomic DNA and mitochondrial integrity.

[Ascending aortic dissection associated with pulmonary contusion caused by blunt trauma]

A 77-year-old female tumbled and struck her front chest wall twice. After the event, hemosputum was observed and she complained of slight chest discomfort. As chest pain continued to worsen a week after the event, she was transferred to our hospital. The computed tomography (CT) revealed an ascending aortic dissection and bilateral pulmonary contusion. In the intensive care unit (ICU), antihypertensive therapy was given immediately and delayed surgical repair was planned because of pulmonary contusion. Twenty days after the event, proximal hemiarch replacement was performed. Postoperative course was uneventful without any complication. She was discharged on the 23rd day after the operation.

Enhancement of ultraviolet-induced apoptosis by NF-kappaB decoy oligonucleotides

BACKGROUND

A decoy strategy utilizing oligonucleotides (ODN) containing the specific binding sequence of a certain transcription factor has been developed and is considered to be a potential new class of antigene therapy. However, the application of this new therapeutic modality to skin diseases has not been fully documented.

OBJECTIVES

The aim of this work was to examine the effects of the nuclear factor (NF)-kappaB decoy ODN on UV-elicited skin change.

METHODS

Mouse keratinocyte Pam 212 cells were transfected with NF-kappaB decoy ODN to examine the effects of the decoy ODN on ultraviolet (UV) B-induced apoptosis. Tape-stripped rat dorsal skin was treated with an ointment containing NF-kappaB decoy ODN for the examination of the in vivo impact of the decoy ODN on sunburned cell (SBC) formation and UVB erythema.

RESULTS

NF-kappaB decoy ODN specifically induced apoptosis of Pam 212 cells and SBC formation was significantly enhanced by topical NF-kappaB decoy ODN ointment, while UV-induced erythema was not affected.

CONCLUSIONS

These data suggest that enhancement of UV-induced apoptosis by NF-kappaB decoy ODN may play a cancer-preventive role by further eliminating photodamaged keratinocytes.

Expression of xyrA gene encoding for D-Xylose reductase of Candida tropicalis and production of xylitol in Escherichia coli

The D-Xylose reductase (XR) gene (xyrA) of Candida tropicalis IFO 0618 was expressed in Escherichia coli JM109. The enzymatic properties of each recombinant XR such as the Km value for D-xylose and NADPH, the substrate specificity for other sugars and the optimal pH were essentially the same as those of the corresponding enzyme of C. tropicalis. The recombinant XR was more heat-stable than C. tropicalis XR at 60 degrees C. E. coli, expressing the xyrA gene, successfully converted D-xylose to xylitol. When D-xylose (50 g/l) and D-glucose (5 g/l) were added to IPTG-induced cells, 13.3 g/l of xylitol was produced during 20 h of cultivation.

Dosage effect of minor arginyl- and isoleucyl-tRNAs on protein synthesis in an Escherichia coli in vitro coupled transcription/translation system

In Escherichia coli mRNA, the arginine codons AGA/AGG and the isoleucine codon AUA are rarely used with frequencies of about 0.35% and 0.41%, respectively. Six genes with a different number of these codons were expressed in an E. coli in vitro coupled transcription/translation system, which contained either tRNA prepared from E. coli cells carrying a plasmid with argU and ileX genes encoding rare tRNAs (tRNA(arg)(AGA/AGG) and tRNA(ile)(AUA)), designated codon-plus tRNA, or normal tRNA from cells lacking the plasmid. Genes having a low number of the rare codons, such as genes encoding chloramphenicol acetyltransferase and anti-gp120 single-chain Fv (artificially constructed to remove rare codons), were expressed at similar levels using with both tRNA preparations. On the other hand, the use of codon-plus tRNA increased the expression levels of genes having a relatively large number of the rare codons, including genes encoding archaeal proteins, green fluorescent protein of jelly fish origin, and a single-chain Fv of mouse origin, by about 20% higher than that using normal tRNA.

L3/Lhx8 is involved in the determination of cholinergic or GABAergic cell fate

The LIM homeobox family of transcription factors is involved in many processes during the development of the mammalian central nerves system. L3, also called Lhx8 (L3/Lhx8), is a recently identified member of the LIM homeobox gene family and is selectively expressed in the medial ganglionic eminence (MGE). Our previous study demonstrated that L3/Lhx8-null mice specifically lacked cholinergic neurons in the basal forebrain. In this study, we reduced L3/Lhx8 function in the murine neuroblastoma cell line, Neuro2a (N2a), using L3/Lhx8-targeted small interfering RNA (siRNA) produced by H1.2 promoter-driven vector. The levels of cholinergic markers per cell were diminished without a reduction in the number of marker-positive cells. Intriguingly, GABAergic marker expression and the number of GABAergic cells were dramatically increased in the differentiating L3/Lhx8-knockdown N2a. These results suggest the possibility that L3/Lhx8 is involved in the determination of transmitter phenotypes (GABAergic or cholinergic cell fate) in a population of neurons during basal forebrain development.

[Clinical evaluation of hydrocolloidal dressing in 147 patients undergoing cardiovascular surgery]

Recent evidence has suggested that a moist environment plays an important role in wound healing. Karayahesive, one type of hydrocolloidal dressing, contains natural karaya gum as a hydrophilic gel. We applied hydrocolloidal dressing to operative wounds in 147 patients who underwent cardiovascular surgery from April 2001 through August 2002 to evaluate its clinical usefulness. The dressing was kept on the wounds for 7 days after operation, but was immediately switched to conventional dressing with gauze if there was any problem. A total of 144 patients (98%) had no wound chest infections. Good wound healing was obtained with only 1 dressing, removed 7 days after operation, in 128 patients (87%). In 19 patients (13%), the hydrocolloidal dressing was switched to conventional dressing. In 13 of these patients the hydrocolloidal dressing dissolved naturally or exudation occurred; clinically, there were no local problems; however, 3 patients had infection, 2 had fat necrosis, and 1 had burn injury caused by electrocautery. No patients had skin problems caused by this dressing. We conclude that hydrocolloidal dressing can be used safely and effectively in patients undergoing cardiovascular surgery and reduce the workload of healthcare workers.

Carcinosarcoma of the parotid gland: an unusual case with large-cell neuroendocrine carcinoma and rhabdomyosarcoma. Case report

We report a case of carcinosarcoma of the parotid gland in a 72-year-old Japanese man. The patient noticed a rapidly enlarging hard mass in the right parotid gland. He underwent radical parotidectomy with cervical lymph node dissection. The resected tumor measured 3.5 x 4.5 cm and histopathologically showed carcinomatous and sarcomatous components. The carcinomatous component consisted of large-cell neuroendocrine carcinoma (LCNEC), squamous cell carcinoma and adenocarcinoma not otherwise specified, while the sarcomatous component included spindle cell sarcoma not otherwise specified, so-called myxosarcoma and rhabdomyosarcoma. The LCNEC component was predominant within the whole tumor. The diagnoses of LCNEC and rhabdomyosarcoma were also confirmed immunohistochemically. With regard to histopathogenesis, based on the lack of histopathological evidence and antecedent history of pleomorphic adenoma, we considered the present case to be de novo, not expleomorphic adenoma.

Expression of beta-catenin, E-cadherin and cyclin D1 in adenoid cystic carcinoma of the salivary gland

We evaluated the expression of beta-catenin, E-cadherin, and cyclin-D1 in 23 cases of adenoid cystic carcinoma (ACC) of the salivary gland. We detected beta-catenin on the cell membranes in all ACCs, but its distribution was irregular, as compared to that on normal structures. In three out of the 23 cases, beta-catenin was detected in the nuclei, as well as on cell membranes. Polymerase chain reaction (PCR) and direct sequencing revealed a missense mutation in one case in which beta-catenin had been detected in the nuclei of tumor cells. We also detected E-cadherin on cell membranes with a similar irregular distribution to that of beta-catenin. In 11 cases (almost 48%) of ACC, cyclin D1 was localized in cell nuclei but there was no correlation with the nuclear staining of the beta-catenin. Our results suggest that disturbances in the distribution of beta-catenin and E-cadherin might affect the morphology ofACC and that a small fraction of cases of ACC are characterized by a mutation in the beta-catenin gene, which is associated with the nuclear accumulation of the product of this gene but does not affect the transcription of the gene for cyclin-D1.

Mild hypothermia reduces expression of intercellular adhesion molecule-1 (ICAM-1) and the accumulation of neutrophils after acid-induced lung injury in the rat

BACKGROUND

The pathophysiology of the acute phase of acid-induced lung injury (AILI) has been elucidated. However, once acute respiratory distress syndrome (ARDS) develops, the mortality rate remains high and there is, as yet, no effective therapy. There are reports that application of mild hypothermia is an effective treatment for ARDS. In this study, we hypothesize that mild hypothermia inhibits activation of neutrophils and expression of intercellular adhesion molecule-1 (ICAM-1) in an injured lung. We studied the effects of mild hypothermia on the expression of ICAM-1 and the accumulation of neutrophils after AILI in the rat.

METHODS

Male Sprague-Dawley rats were randomly allocated to one of the four groups: control normothermic group, induced mild hypothermia group, acid-instilled normothermic group, and acid-instilled group with mild hypothermia. At 6 h after instillation of acid, lungs were removed to measure neutrophil activity and to detect the expression of ICAM-1 in each group.

RESULTS

Oxygenation in acid-instilled rats was significantly impaired as compared to that in non-instilled groups, but induction of mild hypothermia gradually improved oxygenation. Expression of ICAM-1 was enhanced in the acid-instilled normothermic group. By contrast, no overexpression of ICAM-1 and its mRNA was detected in the acid-instilled hypothermic group. In addition, accumulation of neutrophils was markedly inhibited after exposure to mild hypothermia irrespective of the instillation of acid.

CONCLUSION

Our data suggest mild hypothermia can inhibit the adhesion, activation, and accumulation of neutrophils during the acute phase of AILI in the rat and may have the potential to reduce ongoing inflammation of ALI or ARDS.

Continuous hydrogen production from organic waste

The antibiotic effects of lactic acid bacteria, Lactobacillus paracasei, on hydrogen production were investigated using glucose as the substrate for the batch experiments. The effects of lactic acid bacteria on hydrogen fermentation depended on pH and the inhibition of hydrogen-producing bacteria was prevented by keeping the pH over 5.0. Then, a continuous hydrogen production experiment was conducted by using bean curd manufacturing waste as an actual organic waste at pH 5.5 at 35 degrees C. The increase of the substrate concentration and the addition of nitrogen gave precedence to acetic and butyric acids production in the metabolic pathway and suppressed propionic acid production. As the result, continuous hydrogen production from municipal organic waste was enabled.

Post-secretion neutralization of transgene-derived effect: soluble erythropoietin receptor/IgG1Fc expressed in liver neutralizes erythropoietin produced in muscle

BACKGROUND

The regulation of transgene expression is a key issue for the development of safe gene therapy. Various strategies have been used to regulate protein production at the levels of transgene expression, transcription, translation, and secretion. Neutralization following secretion is another important backup system to prevent super-therapeutic levels of a protein from being expressed by gene transfer.

METHODS

We tested whether the soluble human erythropoietin receptor (EpoR)/IgG(1)Fc could neutralize the rat Epo at the post-secretory level and suppress erythrocytosis.

RESULTS

To assess whether soluble human EpoR could bind rat Epo in vitro, we used the Epo-dependent human leukemic cell line, AS-E2. EpoR/IgG(1)Fc significantly inhibited the growth of AS-E2 cells in Epo-containing medium. To test this neutralization effect of EpoR/IgG(1)Fc in vivo, we first transferred pCAGGS-Epo into rat muscle by in vivo electroporation, confirmed erythropoiesis for 3 weeks, and then delivered EpoR/IgG(1)Fc by liver-targeted gene transfer via tail-vein injection with hydrodynamics-based transfection. Reticulocyte counts and hematocrit levels in rats that received pCAGGS-EpoR/IgG(1)Fc injections were significantly lower than in rats that received pCAGGS-EpoR, pCAGGS-IgG(1)Fc, or no injection.

CONCLUSIONS

These results demonstrate that liver-targeted pCAGGS-EpoR/IgG(1)Fc transfer by tail-vein injection with hydrodynamics-based transfection is useful for neutralizing Epo delivered by in vivo electroporation. This backup strategy at the level of post-secretion could facilitate the clinical application of gene therapy in the future.

[Oral sildenafil citrate as an effective alternate in the treatment of postoperative pulmonary hypertensive crisis after congenital heart surgery]

A five-month-old girl of Down syndrome underwent a corrective surgery for complete atrioventricular septal defect. Her postoperative course was complicated with pulmonary hypertensive (PH) crises despite nitroglycerin (NTG) infusion and inhaled nitric oxide (NO). Sildenafil citrate, a phosphodiesterase 5 inhibitor, was administered through a nasogastric tube at a starting dose of 0.3 mg/kg by stepwise increment to the maximum dose of 2 mg/kg 4 hourly. Sildenafil citrate dramatically lowered pulmonary arterial pressure and the patient was weaned from NTG and NO without PH crisis. There was no side effect after sildenafil citrate administration. Oral sildenafil citrate is a safe and potent adjunct to the existing therapies for postoperative PH in infants after open heart surgery.

Gastrointestinal stromal tumor arising in the rectovaginal septum

We report herein a rare case of malignant gastrointestinal stromal tumor (GIST) originated from the rectal wall, which presented as a tumor on the rectovaginal septum. A 54-year-old Japanese woman, gravida 4, para 3, was admitted complaining of anuresis and severe constipation. She had a history of hysterectomy and right salpingo-oophorectomy for uterine leiomyoma 11 years previously. Pelvic examination revealed an 8.5 x 7.5 x 7.5 cm hard mass in the rectovaginal space. The inferior border of the tumor was 2 cm from the vaginal introitus and 2 cm from the anus. Computed tomography and magnetic resonance imaging showed a well-circumscribed soft-tissue mass filling the rectovaginal space. Urinary bladder and rectum were markedly compressed and displaced. Colon fiberscopy revealed invasion of the tumor into the rectal mucosa. An abdominoperineal resection of the rectum with posterior vaginal wall resection and pelvic lymphadenectomy was performed. The resected specimen showed a rectal submucosal tumor that was 8 x 8 x 7 cm in size. The tumor was diagnosed as a malignant GIST. Immunohistochemical analysis confirmed this diagnosis. The patient is now healthy without evidence of recurrence at 13 months after surgery. Gynecologists should be aware of rectal GIST arising in the rectovaginal space as a differential diagnosis of vaginal submucosal tumor.

Transformation potency of ErbB heterodimer signaling is determined by B-Raf kinase

Cellular transformation occurs only in cells that express both ErbB1 and ErbB4 receptors, but not in cells expressing only one or the other of these receptors. However, when both receptors are coexpressed and ligand-stimulated, they interact with virtually the same adaptor/effector proteins as when expressed singly. To reveal the underlying regulatory mechanism of the kinase/phosphatase network in ErbB homo- and heterodimer receptor signaling, extracellular signal-regulated kinase (ERK) and Akt activities were evaluated in the presence of several enzyme inhibitors in ligand-induced cells expressing ErbB1 (E1), ErbB4 (E4), and ErbB1/ErbB4 (E1/4) receptor. The PP2A inhibitor okadaic acid showed receptor-specific inhibitory profiles for ERK and Akt activities. Moreover, B-Raf isolated only from E1/4 cells could induce in vitro phosphorylation for MEK; this B-Raf kinase activity was abolished by pretreatment of the cells with okadaic acid. Our study further showed that the E1/4 cell-specific B-Raf activity was stimulated by PLC gamma and subsequent Rap1 activation. The present study suggests that B-Raf kinase, which was specifically activated in the cells coexpressing ErbB1 and ErbB4 receptors, elevates total ERK activity within the cell and, therefore, can induce cellular transformation.

Malignant lymphoma with tumor thrombus in the portal venous system

We report a case of malignant lymphoma presenting with tumor thrombus of the portal venous system. Computed tomography showed a mass in the portal vein and mesenteric lymphadenopathy. Filling defects in the dilated portal vein also were identified by angiography. This type of the lymphoma is extremely rare, but it should be considered in the differential diagnosis of portal vein thrombus.

Vibrationally resolved fluorescence from organic molecules near metal surfaces in a scanning tunneling microscope

Intrinsic molecular fluorescence from porphyrin molecules on Au(100) has been realized by using a nanoscale multimonolayer decoupling approach with nanoprobe excitation in the tunneling regime. The molecular origin of luminescence is established by the observed well-defined vibrationally resolved fluorescence spectra. The molecules fluoresce at low "turn-on" voltages for both bias polarities, suggesting an excitation mechanism via hot electron injection from either tip or substrate. The excited molecules decay radiatively through Franck-Condon pi(*)-pi transitions.

The novel mutation K87E in ribosomal protein S12 enhances protein synthesis activity during the late growth phase in Escherichia coli

Resistance to streptomycin in bacterial cells often results from a mutation in the rpsL gene that encodes the ribosomal protein S12. We found that a particular rpsL mutation (K87E), newly identified in Escherichia coli, causes aberrant protein synthesis activity late in the growth phase. While protein synthesis decreased with age in cells in the wild-type strain, it was sustained at a high level in the mutant, as determined using living cells. This was confirmed using an in vitro protein synthesis system with poly(U) and natural mRNAs (GFP mRNA and CAT mRNA). Other classical rpsL mutations (K42N and K42T) tested did not show such an effect, indicating that this novel characteristic is typical of ribosomes bearing the K87E mutant form of S12, although the K87E mutation conferred the streptomycin resistance and error-restrictive phenotypes also seen with the K42N and K42T mutations. The K87E (but not K42N or K42T) mutant ribosomes exhibited increased stability of the 70S complex in the presence of low concentrations of magnesium. We propose that the aberrant activation of protein synthesis at the late growth phase is caused by the increased stability of the ribosome.

Gastrointestinal stromal tumor arising in the rectovaginal septum

We report herein a rare case of malignant gastrointestinal stromal tumor (GIST) originated from the rectal wall, which presented as a tumor on the rectovaginal septum.

A 54-year-old Japanese woman, gravida 4, para 3, was admitted complaining of anuresis and severe constipation. She had a history of hysterectomy and right salpingo-oophorectomy for uterine leiomyoma 11 years previously. Pelvic examination revealed an 8.5 × 7.5 × 7.5 cm hard mass in the rectovaginal space. The inferior border of the tumor was 2 cm from the vaginal introitus and 2 cm from the anus. Computed tomography and magnetic resonance imaging showed a well-circumscribed soft-tissue mass filling the rectovaginal space. Urinary bladder and rectum were markedly compressed and displaced. Colon fiberscopy revealed invasion of the tumor into the rectal mucosa. An abdominoperineal resection of the rectum with posterior vaginal wall resection and pelvic lymphadenectomy was performed. The resected specimen showed a rectal submucosal tumor that was 8 × 8 × 7 cm in size. The tumor was diagnosed as a malignant GIST. Immunohistochemical analysis confirmed this diagnosis. The patient is now healthy without evidence of recurrence at 13 months after surgery.

Gynecologists should be aware of rectal GIST arising in the rectovaginal space as a differential diagnosis of vaginal submucosal tumor.

Re-emission of heavy water vapour from soil to the atmosphere

The re-emission process of tritiated water (HTO) deposited on a soil surface is an important process to assess tritium doses to the general public around nuclear fusion facilities in future. A field experiment using heavy water (HDO) as a substitute for HTO was carried out in the summertime to investigate the re-emission process of HTO from soil to the atmosphere. In the experiment, the time variations of depth profiles of HDO concentrations in soil exposed to HDO vapour and soil mixed with HDO were measured during the re-emission process on the field. The HDO concentrations in soil water in top soil layers of both the exposed and mixed soil rapidly decreased with time during the re-emission. However, the decrease of exposed soil was much greater than that of mixed soil. The re-emission process was analysed using a model including the evaporation of HDO from soil, the exchange between soil HDO and air H2O, and the diffusion of HDO in soil. It was found that the model is applicable to calculating the time variations of detailed depth profiles of HDO concentration in soil water in surface soil layers, using an estimated exchange velocity.

Nuclear BAG-1 expression is a biomarker of poor prognosis in esophageal squamous cell carcinoma

Apoptosis is one of the critical biological factors that correlate with the biological behavior of malignant tumors including cancer progression and clinical outcome. The present study was performed to clarify the clinical implications of BAG-1, a bcl-2 binding protein in esophageal squamous cell carcinoma (ESCC). Seventy-one cases with ESCC were investigated. Immunohistochemical study of BAG-1 was performed on resected specimens. The expression pattern of BAG-1 in nuclei and/or cytoplasm was analyzed and correlated with TNM classification, vessel invasion, survival period after surgery. BAG-1 expression in the nuclei was related to the depth of tumor invasion (P = 0.0381) but not to any other clinicopathologic parameters. The cytoplasmic staining pattern of BAG-1 exhibited no correlation with clinicopathologic parameters. Univariate analysis (P < 0.05), but not multivariate analysis, revealed significantly poor prognosis for ESCC cases exhibiting positive nucleic staining for BAG-1. Our data suggests that BAG-1 expression in the nuclei of ESCC plays an important role in tumor development and may be useful for predicting the prognosis after surgery.

Synthesis of 6-(2-thienyl)purine nucleoside derivatives toward the expansion of the genetic code

Unnatural bases specifically pairing with pyridin-2-one, 2-amino-6-(2-thienyl) purine and 2-amino-6-(2-furanyl)purine, were newly designed to replace 2-amino-6-(N,N-dimethylamino)purine. It was expected that these novel purine analogues, as compared with 2-amino-6-(N,N-dimethylamino)purine, might reduce the interference in the stacking interactions with the neighboring bases in a duplex and improve the efficiency of the enzymatic incorporation of the nucleoside triphosphate of pyridin-2-one opposite these unnatural bases. The syntheses of these nucleoside derivatives and the DNA fragments were examined.

Identification of Thermus thermophilus HB8 tRNA (Gm18) methyltransferase gene

For the purpose of identification of the gene for Thermus thermophilus tRNA (Gm18) methyltransferase [tRNA (guanosine-2'-)-methyltransferase, EC 2.1.1.34], the purified enzyme from native source was analyzed by the peptide-mass mapping. The target gene encoded the amino acid sequences of the obtained peptides was searched in data from Thermus thermophilus HB8 genome-sequencing project. We found the target gene AB05130, which was expected to encode a protein composed of 194 amino acid residues and the molecular mass of this protein was calculated as 22083. The recombinant protein was expressed in E. coli as an active form. The Gm18 formation activity of the purified recombinant protein was confirmed by in vitro methylation followed by two-dimensional thin layer chromatography and Liquid Chromatography/Mass Spectrum analysis of substrate tRNA.

Unnatural base pairs between 2-amino-6-(2-thienyl)purine and the complementary bases

The unnatural base, 2-amino-6-(2-thienyl)purine (designated as s), instead of 2-amino-6-(N,N-dimethylamino)purine (designated as x), was designed in order to improve the specificity and efficiency of the base pairing with pyridin-2-one (designated as y). DNA fragments containing s were chemically synthesized, and the thermal stability and the enzymatic reactions involving the s-y pairing were examined. Thermal denaturation experiments showed that the DNA duplex (12-mer) containing the s-y pair was more stable than that containing the x-y pair. The incorporation of dyTP was also more advantageous to the s-y pairing than the x-y pairing in single-nucleotide insertion experiments using the Klenow fragment of Escherichia coli DNA polymerase I.

Small cell carcinoma of the esophagus; clinicopathological and immunohistochemical analysis of six cases

Small cell carcinoma arising in the esophagus is a relatively rare disease. In the more common small cell carcinoma of the lung, the diagnostic significance of several new markers has been recently reported. This study used immunohistochemical techniques in addition to clinicopathological analysis, in order to clarify the utility of newer markers as biological parameters or as diagnostic tools. Six patients with small cell carcinoma of the esophagus were clinicopathologically analyzed. Immunohistochemical staining was performed using primary antibodies for bombesin, CD56 and CD57 in addition to conventional endocrine markers chromogranin A, neuron specific enolase and synaptophysin. All patients died within 2 years of surgery due to cancer recurrence, whether or not they had received adjuvant therapy. Pathological stages ranged from IIa to IVb and lymph node metastasis was observed in five cases. Of the six cases, four showed a positive reaction for bombesin and five were positive for CD57. In contrast, no cases revealed a positive reaction for CD56. The one case to survive 24 months after surgery was not shown to express bombesin, CD56 or CD57. Small cell carcinoma of the esophagus demonstrated an unfavorable prognosis. The study suggested that in this disease, bombesin and CD57 (but not CD56) were useful as biological markers, predicting clinical outcome rather than having diagnostic significance.

Efforts toward creating unnatural base pairs for an expanded genetic code

A series of unnatural base pairs was designed and examined for the expansion of the genetic alphabet and for a better understanding of the mechanism of nucleic acid biosyntheses. To improve the shape complementarity of the previously developed unnatural base pairs, 2-amino-6-(N,N-dimethylamino)purine (x)--pyridon-2-one (y) and 2-amino-6-(2-thienyl)purine (s)--y, the pyrimidine analogue, y, was replaced by a five-member ring, 4-imidazolin-2-one (z), and the s-z pairing in replication was examined. Unnatural bases based on the five-member ring were also applied to the development of non-hydrogen-bonded base pairs.

Photo-regulation of RNA polymerase reaction by use of modified DNA carrying an azobenzene

Transcription reaction by T7-RNA polymerase was photo-regulated on the basis of two strategies as depicted in Scheme 1. It was found that incorporation reaction of azobenzene-tethered uridine triphosphate proceeded only when azobenzene took trans-form (Scheme 1(A)). On the other hand, the transcription was more efficient when the azobenzene moiety, tethered to the non-template strand of the promoter DNA, was in its cis-form under UV irradiation (Scheme 1(B)). Thus, azobenzene-tethered DNAs are promising for the photo-regulation of gene-expression.

Status of NAT screening for HCV, HIV and HBV: experience in Japan

The first nationwide nucleic acid amplification testing (NAT) for hepatitis B virus (HBV), hepatitis C virus (HCV), and human immunodeficiency virus type 1 (HIV-1) of voluntarily donated blood after serological pre-screening and before release of cellular components and plasma for fractionation was implemented by the Japanese Red Cross Blood Transfusion Services. The NAT screening assay using multiplex reagent is time-saving, cost effective, and labour-saving procedure for all blood and blood products including short-shelf life platelets. During the 50-mini-pool NAT screening of serologically negative donations (February 1, 2001-April 30, 2001), we were able to screen out 112 HBV-positive, 25 HCV-positive, and 4 HIV-1 positive units from blood and blood components.

Delayed reactivation of p53 in the progeny of cells surviving ionizing radiation

Ionizing radiation induces genomic instability, which is transmitted through many generations after irradiation in the progeny of surviving cells. To detect delayed activation of p53, we constructed a reporter plasmid containing the p53-responsible promoter and the bacterial beta-galactosidase (beta-gal) gene and introduced it into human fibrosarcoma (HT1080) cells, which retain wild-type p53 function. The resultant clones induce beta-gal protein after X-irradiation, and the induction kinetics were similar to those of p21(WAF1/CIP1) protein. More than 90% of the cells were stained blue when the cells were incubated with X-gal 4 h after 6 Gy of X-rays, whereas very few control cells were beta-gal positive. The primary colonies formed after 6 Gy of X-rays were collected, and they were subjected to secondary colony formation. We observed that a significant number of surviving colonies contained beta-gal-positive cells, suggesting that delayed activation of p53 occurred in the progeny of irradiated cells. We also found higher frequency of phosphorylation of p53, NBS1, and CHK2/Cds1 in the progeny of surviving cells. Furthermore, foci formation of phosphorylated histone H2AX was detected in the progeny of surviving cells. These findings provide the possibility that the observed instability results from these DNA breaks, i.e., the breaks lead to delayed chromosome rearrangements, delayed cell death, and so forth, many generations after irradiation and that activation of p53 function may eliminate cells that have potentially accumulated genomic alterations.

[Combined operation for left ventricular aneurysm and ventricular septal perforation with normal coronary arteries; report of a case]

We experienced a rare case of left ventricular aneurysm (LVA) and ventricular septal perforation (VSP) with normal coronary arteries, and had a good outcome by undergoing Dor procedure and direct closure of VSP individually. A 68-year-old female was printed out cardiac systolic murmur. Echocardiogram revealed LVA and VSP, but coronary arteriogram showed no significant stenosis. The apex was incised longitudinally, lateral and parallel to the interventricular groove. VSP was directly closed by 2 pieces of 3-0 polypropylene suture with felt strip. Purse-string stitch with 3-0 polyester suture around the transitional zone between fibrotic tissue and viable tissue was secured to firm fibrous tissue. The residual orifice was closed with an elliptical composite patch of equine pericardial patch and polyester velour with 3-0 polypropylene suture. We considered based on the operative finding that myocardial infarction (MI) led to LVA and VSP. Coronary thrombosis rather than coronary spasm may have provoked MI because spasm provocative test was negative.

[Bilateral coronary ostial stenoses with aortic regurgitation in a patient with syphilitic aortitis]

Syphilitic aortitis is now rare in developed countries and is sometimes overlooked. A 61-year-old man with bilateral coronary ostial stenoses (#5:90%, #1:99%) and Sellers III/IV aortic regugitatioin (AR) induced by syphilitic aortitis presented with chest pain. Preoperative rapid plasma reagin titer and Treponema pallidum hemagglutination test were strongly positive, 256 fold and 191.25 C.O.I., respectively. Aortic valve replacement (AVR) and coronary artery bypass grafting (CABG) with bilateral internal thoracic arteries (ITA) was performed successfully. The angiographic features as follows: 1) coronary artery stenosis is generally limited to the ostia, 2) the grade of stenosis is almost always more than 90%, 3) AR is frequently associated with coronary ostial stenosis. CABG should be performed with ITA, not saphenous vein grafts, to avoid occlusion of the ostium of the saphenous vein graft by syphilitic aortitis. Retrograde cardioplegia should be performed if ostial stenosis is severe.

The expression of PDGF, its receptors and capillary morphometry in the developing lung: quantitative studies

The aim of the present study was the evaluation of the expression levels of PDGF-A and B, and PDGFR-alpha, andchanges of capillary cross-sectional areas during terminal vascular network formation in the developing lung. Pathogen-free fetuses and newborns used for rats were used. Lungs were processed for frozen section immunohistochemical staining and parallel tissue specimens were prepared for transmission electron microscopy. The expression levels of PDGF-A and B, and PDGFR-alpha were obtained using quantitative image analysis. Additionally. the morphometry of capillary cross-sectional area was performed. We found that the expression levels of the studied antigens fluctuated, and the highest values were found in21-day old fetuses (p < 0.0001). Although there were no significant differences of the area of "a single" capillary, the area of the endothelium decreased significantly in perinatal period (p <0.0001). We conclude that the statistically significant changes of the studied antigens' expression as well as the of capillary cross-sectional area occur in the perinatal period,