Nonlinear electrical impedance spectroscopy of viruses using very high electric fields created by nanogap electrodes

Our living sphere is constantly exposed to a wide range of pathogenic viruses, which can be either known, or of novel origin. Currently, there is no methodology for continuously monitoring the environment for viruses in general, much less a methodology that allows the rapid and sensitive identification of a wide variety of viruses responsible for communicable diseases. Traditional approaches, based on PCR and immunodetection systems, only detect known or specifically targeted viruses. We here describe a simple device that can potentially detect any virus between nanogap electrodes using nonlinear impedance spectroscopy. Three test viruses, differing in shape and size, were used to demonstrate the general applicability of this approach: baculovirus, tobacco mosaic virus (TMV), and influenza virus. We show that each of the virus types responded differently in the nanogap to changes in the electric field strength, and the impedance of the virus solutions differed depending both on virus type and virus concentration. These preliminary results show that the three virus types can be distinguished and their approximate concentrations determined. Although further studies are required, the proposed nonlinear impedance spectroscopy method may achieve a sensitivity comparable to that of more traditional, but less versatile, virus detection systems.

Gene expression in Pre-MBT embryos and activation of maternally-inherited program of apoptosis to be executed at around MBT as a fail-safe mechanism in Xenopus early embryogenesis

S-adenosylmethionine decarboxylase (SAMDC) is an enzyme which converts S-adenosylmethione (SAM), a methyl donor, to decarboxylated SAM (dcSAM), an aminopropyl donor for polyamine biosynthesis. In our studies on gene expression control in Xenopus early embryogenesis, we cloned the mRNA for Xenopus SAMDC, and overexpressed the enzyme by microinjecting its mRNA into Xenopus fertilized eggs. In the mRNA-injected embryos, the level of SAMDC was enormously increased, the SAM was exhausted, and protein synthesis was greatly inhibited, but cellular polyamine content did not change appreciably. SAMDC-overexpressed embryos cleaved and developed normally up to the early blastula stage, but at the midblastula stage, or the stage of midblastula transition (MBT), all the embryos were dissociated into cells, and destroyed due to execution of apoptosis. During cleavage SAMDC-overexpressed embryos transcribed caspase-8 gene, and this was followed by activation of caspase-9. When we overexpressed p53 mRNA in fertilized eggs, similar apoptosis took place at MBT, but in this case, transcription of caspase-8 did not occur, however activation of caspase-9 took place. Apoptosis induced by SAMDC-overexpression was completely suppressed by Bcl-2, whereas apoptosis induced by p53 overexpression or treatments with other toxic agents was only partially rescued. When we injected SAMDC mRNA into only one blastomere of 8- to 32-celled embryos, descendant cells of the mRNA-injected blastomere were segregated into the blastocoel and underwent apoptosis within the blastocoel, although such embryos continued to develop and became tadpoles with various extents of anomaly, reflecting the developmental fate of the eliminated cells. Thus, embryonic cells appear to check themselves at MBT and if physiologically severely-damaged cells occur, they are eliminated from the embryo by activation and execution of the maternally-inherited program of apoptosis. We assume that the apoptosis executed at MBT is a "fail-safe" mechanism of early development to save the embryo from accidental damages that take place during cleavage.

Occurrence of pre-MBT synthesis of caspase-8 mRNA and activation of caspase-8 prior to execution of SAMDC (S-adenosylmethionine decarboxylase)-induced, but not p53-induced, apoptosis in Xenopus late blastulae

Overexpression of S-adenosylmethionine decarboxylase (SAMDC) in Xenopus fertilized eggs activates caspase-9 and executes maternal program of apoptosis shortly after midblastula transition (MBT). We find that overexpression of caspase-8 and p53, like that of SAMDC, induces apoptosis in Xenopus late blastulae. The apoptosis induced by p53 was abolished by injection of mRNA for xdm-2, a negative regulator of p53, and by injection of a peptide inhibitor or a dominant-negative type mutant of caspase-9, but not caspase-8. The apoptosis induced by SAMDC was not abolished by injection of xdm-2 mRNA, but was abolished by injection of a peptide inhibitor or a dominant-negative type mutant mRNA of both caspase-9 and caspase-8. Unlike caspase-9 mRNA, caspase-8 mRNA did not occur as a maternal mRNA rather induced to be expressed during cleavage stage (pre-MBT stage) by overexpression of SAMDC but not p53. Furthermore, while activities to process procaspase-8 and procaspase-9 appeared in SAMDC-overexpressed apoptotic embryos, the activity to process procaspase-8 did not appear in p53-overexpressed apoptotic embryos. We conclude there are at least two pathways in the execution of the maternal program of apoptosis in Xenopus embryos; one being through do novo expression of caspase-8 gene during cleavage stage, and the other without involvement of caspase-8.

Use of plasma exchange and heparin during cardiopulmonary bypass for a patient with heparin induced thrombocytopenia: a case report

Patients with documented history of heparin-induced thrombocytopenia (HIT) pose a difficult problem during surgery using cardiopulmonary bypass (CPB). Several alternatives to heparin exist, but these products either are not approved for use in the United States or have more side effects than heparin. We report on a patient with documented heparin-induced antibody and left main coronary artery disease who underwent uneventful coronary artery bypass surgery and recovery by using preoperative plasmaphresis and limited use of porcine intestinal heparin during CPB.

CT fluoroscopy-guided intervention: marked reduction of scattered radiation dose to the physician's hand by use of a lead plate and an improved I-I device

PURPOSE

To estimate the effects of a lead plate, three types of needle holders, tube current, and slice thickness on decreasing the radiation dose to the physician's hand during interventional procedures with computed tomographic (CT) fluoroscopic guidance. The needle holders (I-I devices), which were developed by the authors, maintained the distance between the physician's hand and the CT plane at 7 cm, 10 cm, and 15 cm, respectively.

MATERIALS AND METHODS

The dose rate (mSv/tube current/CT fluoroscopy time) was measured in 55 cases, which were divided into six groups. In group A (n = 14), the current was 135 kV, there was a 5-mm slice thickness, and a 7-cm I-I device was used without the lead plate. Group B (n = 11) entailed a 120-kV current, a 5-mm slice thickness, and a 7-cm I-I device without the lead plate. Group C (n = 8) entailed a 120-kV current, 5-mm slice thickness, and 7-cm I-I device with the lead plate. Group D (n = 9) entailed a 120-kV current, 5-mm slice thickness, and 10-cm I-I device with the lead plate. Group E (n = 7) entailed a 120-kV current, 5-mm slice thickness, and 15-cm I-I device with the lead plate. Group F (n = 6) entailed a 120-kV current, 1-mm slice thickness and 10-cm I-I device with the lead plate. To compare the effects of tube voltage, lead plate use, slice collimation, and I-I devices, differences were compared between groups A and B, B and C, D and F, and among groups C, D, and E.

RESULTS

The dose rates of groups A, B, C, D, E, and F were 126.3, 75.2, 17.8, 13.9, 2.8, and 4.1 mSv/mA/sec x 100,000, respectively. There were significant differences in dose rates between groups A and B (t-test, P =.037), B and C (Student t-test, P =.002), D and F (Mann-Whitney test, P =.011), and among groups C, D, and E (Kruskal-Wallis test, P =.016).

CONCLUSION

The lead plate, the improved I-I devices, use of a 120 kV (vs 135 kV) current, and 1-mm (vs 5 mm) collimation were all useful in decreasing the dose rate.

Successful repair of esophageal injury using an elastin based biomaterial patch

An esophageal injury with significant tissue loss is very difficult to repair. We conducted an in vivo study to test our elastin based acellular biomaterial patch to repair such defect. The patch was made from porcine aorta, by decellularization and sterilization. Collagen fibers were preserved to retain mechanical strength and enhance cellular in-growth. Ten domestic pigs underwent right thoracotomy. A 2 cm circular defect was made on the distal esophagus, excising half its circumference, and was repaired using the biomaterial patch and sutures. Soon after the procedure, the animals resumed oral feeding. They were followed for clinical status, weight gain, barium studies, and endoscopic studies, and were killed after 6 weeks to 4 months. All ten animals survived long term, with a procedure success rate of 100% (10 of 10). With the exception of one pneumothorax, no complications occurred, and all animals resumed oral feeding and gained weight. Endoscopic studies showed mucosal coverage by 6 weeks, with minimal stricture at the repair site. Excised specimens showed complete mucosal coverage with regeneration of all three layers. Our biomaterial patch can be used safely and reliably for repair of esophageal injury with significant tissue loss when repaired immediately as in our experiment.

Sutureless liver repair and hemorrhage control using laser-mediated fusion of human albumin as a solder

BACKGROUND

Major liver trauma has a high mortality because of immediate exsanguination and a delayed morbidity from septicemia, peritonitis, biliary fistulae, and delayed secondary hemorrhage. We evaluated laser soldering using liquid albumin for welding liver injuries.

METHODS

Fourteen lacerations (6 x 2 cm) and 13 nonanatomic resection injuries (raw surface, 8 x 2 cm) were repaired. An 805-nm laser was used to weld 53% liquid albumin-indocyanine green solder to the liver surface, reinforcing it by welding a free autologous omental scaffold. The animals were heparinized and hepatic inflow occlusion was used for vascular control. For both laceration and resection injuries, 16 soldering repairs were evaluated acutely at 3 hours. Eleven animals were evaluated chronically, two at 2 weeks and nine at 4 weeks.

RESULTS

All 27 laser mediated-liver repairs had minimal blood loss compared with the suture controls. No dehiscence, hemorrhage, or bile leakage was seen in any of the laser repairs after 3 hours. All 11 chronic repairs healed without complication.

CONCLUSION

This modality effectively seals the liver surface, joins lacerations with minimal thermal injury, and works independently of the patient's coagulation status.

Intrahepatic portosystemic venous shunts: spectrum of CT findings in external and internal subtypes

PURPOSE

The purpose of this work was to survey the spectrum of CT findings in intrahepatic portosystemic venous shunts (IPSVSs).

METHOD

One thousand consecutive liver CT scans examined with an enhanced helical technique were retrospectively reviewed on workstation to find IPSVSs.

RESULTS

IPSVSs were noted in 37 patients and divided into two subtypes according to the location of the communicating systemic vein, either outside (external type, n = 34) or within (n = 4) the liver (one patient had both internal and external types). All the external-type shunts were noted in cases with portal hypertension (n = 34). Most shunts (n = 30) ran through segment 4 and/or 3 and came out near the falciform ligament, but five shunts were noted in segment 2 communicating either with the systemic vein (n = 3) or probably with an enlarged left gastric vein (n = 2). Solitary portohepatic venous shunts (internal type) were noted in three cases with (n = 2) or without (n = 1) aneurysmal dilatation and many portohepatic venous shunts in another patient.

CONCLUSION

IPSVSs of the external type were far common than those of the internal type, always associated with increased pressure of the portal system and in specific sites probably lacking the hepatic capsule.

Liver repair and hemorrhage control by using laser soldering of liquid albumin in a porcine model

BACKGROUND AND OBJECTIVE

We evaluated laser soldering by using liquid albumin for welding liver injuries. Major liver trauma has a high mortality because of immediate exsanguination and a delayed morbidity from septicemia, peritonitis, biliary fistulae, and delayed secondary hemorrhage.

STUDY DESIGN/MATERIALS AND METHODS

Eight laceration (6 x 2 cm) and eight nonanatomic resection injuries (raw surface, 6 x 2 cm) were repaired. An 805-nm laser was used to weld 50% liquid albumin-indocyanine green solder to the liver surface, reinforcing it with a free autologous omental scaffold. The animals were heparinized and hepatic inflow occlusion was used for vascular control. All 16 soldering repairs were evaluated at 3 hours.

RESULTS

All 16 laser mediated liver repairs had minimal blood loss as compared with the suture controls. No dehiscence, hemorrhage, or bile leakage was seen in any of the laser repairs after 3 hours.

CONCLUSION

Laser fusion repair of the liver is a reliable technique to gain hemostasis on the raw surface as well as weld lacerations.

Biopsy of lung nodules with use of I-I device under intermittent CT fluoroscopic guidance: preliminary clinical study

PURPOSE

To investigate the efficacy of computed tomography (CT) fluoroscopy and a new needle holder (the I-I device) in lung nodule biopsy.

MATERIALS AND METHODS

The I-I device is made of acrylate resin and was used to keep the entire needle in the tomographic plane. This study consisted of biopsies of 79 lung nodules in 77 patients. The final diagnoses were malignant in 54 patients, benign in 23, and unconfirmed in two. The biopsy procedure time from the beginning of the CT fluoroscopy procedure to the removal of the needle was measured for 24 needle passes. The radiation dose on the physician's hand was measured in five cases with use of a thermoluminescence ring.

RESULTS

Fifty-one malignant and 20 benign lesions were correctly diagnosed with histologic specimens (90%). In 58 of 77 patients (75%), the biopsy procedures were completed within a single breath-hold. Pneumothorax occurred in 20 of 77 patients (26%) and chest tube insertion was required in five. The incidence of pneumothorax was significantly lower in patients who held their breath during biopsy procedures compared with those who did not (P < .0001; chi2 test). The biopsy procedure time ranged from 15 to 39 seconds (mean: 28.2 sec). The mean radiation dose on the physician's hand was 2 mSv/case.

CONCLUSION

The diagnostic accuracy of biopsy with use of the I-I device under CT fluoroscopic guidance is comparable with that of the conventional method; however, a combination of CT fluoroscopy and the I-I device enables rapid biopsy procedures.

Effects of transmyocardial laser revascularization by using a prototype pulsed CO2 laser on contractility and perfusion of chronically ischemic myocardium in a porcine model

The purpose of this study was to test a new prototype pulsed CO2 laser to be used for transmyocardial laser revascularization (TMR). We wanted to determine whether it can reduce thermal damage and mitigate induced ischemia with improvement in contractile reserve of the heart as evidenced by contrast echocardiography at rest and under dobutamine stress. TMR is an emerging surgical strategy for treatment of myocardial ischemia not amenable to conventional percutaneous or surgical revascularization. Eleven pigs underwent ameroid occluder placement at the origin of the circumflex coronary artery. Six weeks later, occlusion of the circumflex coronary artery was documented. TMR was then carried out on 10 pigs by using a prototype pulsed CO2 laser that delivered 8-12 joules in 1.5 ms with a spot size of 1 mm. Six weeks after TMR, the pigs were restudied. The animals developed significant ischemia after 6 weeks of ameroid occlusion, at rest (p = 0.01) and at peak stress (p = 0.004). Wall motion for the ischemic segments improved significantly 6 weeks after TMR at peak stress (p = 0.02). TMR results in an improvement in wall motion in our model of chronic ischemia and improves wall motion score index more during induced stress than at rest.

Severe hemorrhagic complication due to acquired factor V inhibitor after single exposure to bovine thrombin product

Hemorrhagic complications have been reported after repeated exposures to bovine thrombin products due to development of factor V inhibitors. Our patient underwent emergency repair of acute aortic dissection and coronary artery bypass grafting. The patient developed leg wound infection at the saphenous vein harvest site, which was debrided and left open. Attempt to reclose the leg wound 1 month later was complicated by a life-threatening hemorrhage with markedly elevated activated partial thromboplastin time. There was no evidence of infection or disseminated intravascular coagulation, and further study identified low factor V level with positive factor V inhibitor. Treatment with plasmapheresis and steroid successfully reversed the coagulopathy. Detailed case review failed to reveal exposure to any thrombin products other than the one used for the aortic dissection repair. This case was unusual because only a single exposure to this product resulted in severe hemorrhagic complication 1 month after surgery.

Diagnosis of chest wall invasion by lung cancer: useful criteria for exclusion of the possibility of chest wall invasion with MR imaging

PURPOSE

To compare the accuracy of thin-section CT, conventional static MR imaging (conventional MRI), and breathing dynamic echo planar magnetic resonance imaging (BDEPI) in evaluating lung cancer invasion to the chest wall.

MATERIALS AND METHODS

Thin-section CT, conventional MRI, and BDEPI were performed preoperatively in 20 patients suspected of having primary lung cancers adjacent to the chest wall on conventional CT. The results of imaging findings were compared with those of surgical and histopathological findings.

RESULTS

All patients were confirmed to have no chest wall invasion after surgery. By thin-section CT, 10 of 20 patients were correctly diagnosed as having no chest wall invasion (50% specificity). Two of the 20 patients were incorrectly diagnosed as having chest wall invasion by conventional MRI and BDEPI (90% specificity).

CONCLUSION

When chest wall invasion is suspected on CT scans, static and breathing dynamic MRI are recommended to avoid false positive interpretations.

Use of a new elastin patch and glue for repair of a major duodenal injury

Major duodenal injury with significant tissue loss causes high morbidity and mortality. Our new elastin based heterograft combined with small intestinal submucosa (SIS) and biodegradable glue could be used for repair of such defects. Twenty-four domestic pigs were anesthetized and underwent celiotomy. A 2 cm circular defect was created at the second portion of the duodenum with scissors, excising one-half of its circumference. Our elastin patch, combined with SIS, was applied to cover the defect using biodegradable cyanoacrylate glue and a few sutures. It was then covered with omentum. Animals were followed by weight gain, endoscopic evaluation, and upper GI barium studies. After 2-5 months, animals were sacrificed to obtain specimens. One failed in 3 days due to a technical problem, and one failed in 20 days due to an abdominal abscess. The other 22 animals (22/24, 91.7%) did well, gaining weight. Early endoscopic studies (5-14 d) showed an intact patch. Upper GI studies showed varying degrees of stenosis at the repair site at 3-4 months. Sacrifice after 2-5 months showed complete healing of the defect and a dissolved patch. Our new elastin patch material provides a reliable barrier for repair of duodenal injury, and the biodegradable glue provides quick and easy watertight tissue fusion for our patch.

Structure and chromosome mapping of the human SIX4 and murine Six4 genes

Six4, a member of the homeobox gene subfamily (Six), is expressed in a developmentally regulated fashion, and supposed to be involved in embryogenesis. We cloned the human SIX4 and murine Six4 genomic DNAs and determined their structures. The structure, including the 5' upstream region of both genes, was well conserved suggesting the conserved function and regulation of these genes. Human SIX4 was mapped to chromosome 14q23.

Deletion analysis of Qbeta replicase. Participation of the carboxyl-terminal region of the beta-subunit protein in template recognition

We have analyzed one of the functional domains of Qbeta replicase, an RNA-dependent RNA polymerase of RNA coliphage Qbeta. Deletion mapping analysis of the carboxyl-terminal region of the beta-subunit protein revealed that the terminal 18 amino acid residues (positions 571-588) are dispensable for the replicase reaction. Subsequent deletions up to the Ala-565 residue reduced the RNA polymerizing activity of the replicase in vivo but increased it in vitro. The mutant replicases with enhanced in vitro RNA polymerizing activity were found to have relaxed template specificity for ribosomal RNAs and cellular RNAs as well as Qbeta RNA. Deletions beyond the Ile-564 residue abolished both the RNA polymerizing activity and the binding ability to midivariant (MDV)-poly(+) RNA, a derivative of a natural template for Qbeta replicase, MDV-1 RNA. These results suggest that the carboxyl-terminal part of the beta-subunit participates in RNA recognition of Qbeta replicase.

A study on the function of the glycine residue in the YGDD motif of the RNA-dependent RNA polymerase beta-subunit from RNA coliphage Q beta 1

Q beta replicases in which the Gly residue of the beta-subunit in the motif sequence, YGDD, was replaced with Ala, Ser, Pro, Met, or Val lost their replicase activity in vivo. In an in vitro Mg(2+)-dependent RNA-synthesizing system using poly(rC) or MDV-poly(+) RNA (a derivative of the naturally occurring small RNA that accumulates in the cells during Q beta phage infection) as templates, the lysates from the cells expressing such defective replicases exhibited only 2-6% of the enzyme activity of the lysate from those expressing wild-type replicase. However, the defective replicases, especially A357, with Ala substituted for the Gly, recovered enzyme activity when Mn2+ was added to the reaction mixture. Furthermore, the characteristics of the MDV-poly(+) RNA-dependent RNA synthesis by A357 replicase were similar to those by wild-type replicase in the presence of Mn2+. Gel retardation assay showed that all of the defective replicases could bind MDV-poly(+) RNA. These results suggest that the Gly residue in this motif of Q beta replicase is involved in Mg(2+)-catalyzed polymerization. In the Mn(2+)-catalyzed polymerization, A357 and S357 replicases can act as well as the wild-type replicase.

Estimation of remnant liver function before hepatectomy by means of technetium-99m-diethylenetriamine-pentaacetic acid galactosyl human albumin

To improve the results of hepatectomy in cirrhotic patients, the likely reserve function of the liver was evaluated before surgery. Asialoglycoprotein receptor (ASGP-R) is a hepatic cell surface receptor specific for galactose-terminated glycoproteins. Technetium-99m-diethylene triamine pentaacetic acid-galactosyl human serum albumin (99mTc-GSA) is a newly developed analog ligand to ASPG-R. The probable functional reserve of the remnant liver after hepatectomy was estimated preoperatively as the hepatic binding protein (HBP) concentration specific for ASGP-R on the hepatocellular membrane of the remnant liver. This estimate was based on the effective liver volume rate, obtained by the uptake of 99mTc-GSA. In all, 3 normal volunteers, 3 patients with chronic hepatitis (CH), 9 patients with liver cirrhosis (LC), 2 patients with hepatic cystadenoma, 3 patients with hepatocellular carcinoma (HCC) associated with CH, and 21 HCC patients with LC were studied. The mean value +/- SD obtained for HBP in normal volunteers (three cases) and in patients with mild (four cases), moderate (two cases), and severe liver damage (five cases) were 0.74 +/- 0.03 microM, 0.43 +/- 0.042 microM, 0.31 +/- 0.05 microM, and 0.20 +/- 0.05 microM, respectively. Most of the cases in which the preoperative HBP of the remnant liver was above 0.22 microM had a good postoperative course irrespective of the type of hepatectomy. On the other hand, in subjects with a remnant liver HBP of between 0.22 and 0.11 microM, postoperative severe liver dysfunction occurred in about 50% of cases. In all cases with a remnant liver HBP below 0.1 microM, the prognosis was very poor, indicating that hepatectomy should be avoided. The HBP concentration detected by the 99mTc-GSA study is a very sensitive indicator of changes in the hepatic functional reserve, and the HBP value for the functional reserve of the remnant liver is extremely useful for estimating the liver function before and after hepatectomy.

Regulation of the Escherichia coli hfq gene encoding the host factor for phage Q beta

The host factor (HF-I) for phage Q beta RNA replication is a small protein of 102 amino acid residues encoded by the hfq gene at 94.8 min on the Escherichia coli chromosome. The synthesis rate of HF-I at the exponential-growth phase is higher than at the stationary phase, and it increases concomitantly with the increase in cell growth rate. The intracellular level of HF-I is about 30,000 to 60,000 molecules per cell, the majority being associated with ribosomes as one of the salt wash proteins. Taken together, we suggest that HF-I is one of the growth-related proteins.

[Surgical analysis of mediastinal lymphangioma--analysis of 7 cases]

Mediastinal lymphangioma is a very rare disease. In this study, we evaluated 7 surgically treated cases of mediastinal lymphangioma. Four males and 3 females with ages ranging from 5 months to 74 years (average 31.4 years) were examined. Four patients were asymptomatic but had abnormal shadows on their chest X-ray. Of the remaining patients, one had hoarseness and another had superior vena cava syndrome and both had dyspnea. The other patient was discovered because of cervical tumor. Multiple lymphangiomas were found in only 2 patients. One patient had 4 tumors and the other had 2 tumors in the mediastinum. Of all lymphangiomas, 2 were found in the superior mediastinum, 2 in the anterior mediastinum, 3 in the median mediastinum and 3 in the posterior mediastinum. All patients had cystic lymphangioma including 1 with capillary lymphangioma and 1 with cavernous lymphangioma. Median sternotomy was performed in 3 of the patients and posterolateral thoracotomy was performed in the remainder. The cervical tumor was removed by local incision. Complete resection of the lymphangiomas was performed and no recurrence was observed after surgery.

Transcatheter placement of an intraluminal prosthesis for the thoracic aorta. A new approach to aortic dissections

A new aortic prosthesis (SAP, shape memory aortic prosthesis) was developed with its transfemoral placement system to treat aortic dissection with minimal invasion. The SAP consists of a Nitinol stent and polyurethane tube, and it is designed in such a configuration that it can be compressed inside a 14 Fr catheter when cold. It regains its original shape when warmed to 30 degrees C. From the results of intra-aortic sutureless placement of SAP in 10 mongrel dogs, we concluded that a SAP of proper diameter could be implanted safely for more than 3 months. The transfemoral placement system is composed of a delivery catheter, pushing rod, catching catheter, and pulling wire. Using these devices, transfemoral placement of SAP was demonstrated successfully in three dogs and one sheep. The original SAP and delivery system can be used as an emergency procedure for aortic dissections, such as Stanford type B. The advantages of the procedure are minimal invasion of acutely ill patients and prompt application in the catheter laboratory.

Identification and sequence determination of the host factor gene for bacteriophage Q beta

The host factor (HF-I) required for phage Q beta RNA-directed synthesis of complementary minus-strand RNA was purified to homogeneity from phage-infected Escherichia coli cells. The hfq gene encoding HF-I was cloned using synthetic probes designed based on the partial amino acid sequence of HF-I, and mapped at 94.8 min on the E. coli chromosome downstream of the miaA gene involved in 2-methylthio-N6-(isopentyl)-adenosine (ms2i6A) tRNA modification. Sequence determination of the cloned hfq gene indicated that HF-I is a small protein of Mr 11,166 consisting of 102 amino acid residues.

Syntheses, antiinflammatory, and analgesic activities of arylbiurets

A number of arylbiurets were prepared and evaluated as antiinflammatory and analgesic agents by using the carrageenan paw edema and acetic acid stretching tests. Among them, the antiinflammatory activity of 1,3-dimethyl-5-phenylbiuret (7), 1-ethyl-3-methyl-5-phenylbiuret (11), and 1,1,3-trimethyl-5-phenylbiuret (13) were found to be more potent than phenylbutazone. The analgesic activity of 7 and of 5-(4-chlorophenyl)-1,1,3-trimethylphenylbiuret (16) is higher than that of aminopyrine.

[An experimental study of the heart and lung preservation using autoperfusion method--a study for prolonged preservation]

Heart and lung transplantation is the only definitive treatment available for the patients with end-stage primary pulmonary arterial disease and Eisenmenger's syndrome. Paucity of donor and limited time of preservation of the lungs are the primary factors to limit its extensive use. We have been using autoperfusing heart-lung preparation (AHLP) for preservation of the heart and lungs in experimental animals. Metabolic substrate, amount of venous return, and pulmonary injury, which was histologically consistent with edema and hemorrhage, were the major factors to determine the survival of the donor organs, and appropriate countermeasures were thought to be necessary. The leukocyte count changes immediately after starting the preservation suggested that pathological changes of the lungs have already been induced in the very early period of AHLP. A-aDO2 changes and histological study showed that steroid and urinastatin effectively reduced the pulmonary injury. By using these drugs from very early phase of AHLP, using hyperalimentation solution of balanced substrate to improve metabolism, and setting the venous return to 30ml/kg/min, we succeeded in stable preservation of the heart and lungs for 12 hours.

Characterization of four different mammalian-cell-derived recombinant human interferon-beta 1s. Identical polypeptides and non-identical carbohydrate moieties compared to natural ones

In order to evaluate the structural identification of various recombinant human interferon-beta 1s, the recombinant proteins were produced in four different mammalian cells (human PC12 and PC8 lung adenocarcinoma cells, Chinese hamster ovary cells and mouse C127 cells) and characterized. Each mammalian-cell-derived recombinant human interferon-beta 1 represented a single band of 23 kDa on sodium dodecyl sulphate/polyacrylamide gel electrophoresis, the same molecular mass as fibroblast-derived natural human interferon-beta 1. Specific activities, amino acid compositions, amino-terminal sequences, peptide maps on C18 reversed-phase high-performance liquid chromatography and circular dichroic spectra of recombinant proteins were in good agreement with natural ones. On the other hand, the patterns of isoelectric focusing were different between mammalian-cell-derived recombinant human interferon-beta 1s and natural human interferon-beta 1. Sugar composition analysis revealed that the recombinant protein from Chinese hamster ovary cells has a similar sugar composition to that of natural protein and the other recombinant proteins have increased amounts of galactose and glucosamine in comparison to the natural protein. Furthermore, there is no galactosamine in the natural protein, while small amounts of galactosamine were detected in the oligosaccharides released from PC8- and C127-derived recombinant proteins by N-glycanase. These results indicate that mammalian-cell-derived recombinant human interferon-beta 1s have identical polypeptides to those of natural human interferon-beta 1 but their carbohydrate moieties, including unusual N-linked oligosaccharides, are individually different from natural ones and depend on the host cell.

Molecular cloning of complementary DNA for human medullasin: an inflammatory serine protease in bone marrow cells

Medullasin, an inflammatory serine protease in bone marrow cells, modifies the functions of natural killer cells, monocytes, and granulocytes. We have cloned a medullasin cDNA from a human acute promyelocytic cell (ML3) cDNA library using oligonucleotide probes synthesized from the information of N-terminal amino acid sequence of natural medullasin. The cDNA contained a long open reading frame encoding 237 amino acid residues beginning from the second amino acid of natural meduallasin. The deduced amino acid sequence of medullasin shows a typical serine protease structure, with 41% homology with pig elastase 1.

Promoter analysis of the phosphoenolpyruvate carboxylase gene of Escherichia coli

In order to find the promoter region of phosphoenolpyruvate carboxylase [EC 4.1.1.31] gene (ppc), in vitro transcription was performed using truncated DNA fragments as templates. Transcription mapping showed three promoters as candidates, but only one of them could be assigned to the promoter of ppc gene, considering the nucleotide sequence of its coding region (Fujita, N., Miwa, T., Ishijima, S., Izui, K. and Katsuki, H. (1984) J. Biochem. 95, 909-916). Nuclease S1 mapping showed that the in vivo and in vitro transcription initiation sites are identical and that the site lies 91 or 92 nucleotides upstream the translation initiation site. No alteration of the transcription initiation site was observed whether the cells were starved for an amino acid or grown on various carbon sources. The sequences of the -10 and -35 regions were fairly in accordance with the consensus sequences hitherto reported. Some features of the sequence around the promoter region were discussed.

Transcriptional organization of the rpsA operon of Escherichia coli

Three strong and two minor rpsA promoters were found by nuclease S1 mapping, promoter cloning and in vitro transcription. The longest transcript encodes a protein, located upstream from rpsA with a molecular weight of 25,000. The identity of this protein remains to be established. The other rpsA promoters are located within the gene for this 25 K protein. The rpsA leader region including the sequence of the 25 K protein and its promoter was DNA sequenced.

Promoter selectivity of Escherichia coli RNA polymerase. Differential stringent control of the multiple promoters from ribosomal RNA and protein operons

Using the in vitro mixed transcription system (Kajitani, M., and Ishihama, A. (1983) Nucleic Acids Res. 11, 671-686; Kajitani, M., and Ishihama, A. (1983) Nucleic Acids Res., 11, 3873-3889) we examined the effect of guanosine 3'-diphosphate, 5'-diphosphate (ppGpp), the chemical mediator of stringent control, on transcription of various Escherichia coli DNA fragments, each carrying a single specific promoter. We found that ppGpp inhibits transcription of stringently controlled genes, rrnE, rpsA, and rplJ, coding for ribosomal RNA, ribosomal protein S1 and L10, respectively, but not that of trp (tryptophan) and lacUV5 (lactose) genes. Among the multiple promoters of the rrnE and rpsA operons, the upstream promoters, rrnEp1 and rpsAp1, are subject to repression by ppGpp but the downstream promoters, rrnEp2 and rpsAp3, are insensitive. Taking these facts and the intrinsic strength of the respective promoters together, we suggest that the multiple promoters within the single and same operons play different physiological roles and are regulated by independent mechanisms. The inhibition by ppGpp takes place even after formation of open complexes, suggesting that the RNA polymerase bound to the sensitive promoters is accessible for interaction with ppGpp leading to rapid decay of the open complexes. During this study, we noticed that some promoters including recAp are activated in the presence of ppGpp, raising a possibility that ppGpp has dual effects on the promoter function.

Promoter selectivity of Escherichia coli RNA polymerase. II: Altered promoter selection by mutant holoenzymes

Using the in vitro mixed transcription system (Kajitani and Ishihama (1983a, 1983b), we examined selective transcription of truncated DNA templates carrying lac(UV5), rrnE or rpsA promoters by RNA polymerase holoenzymes from pairs of wild-type parents and mutants with a mutation in one or more RNA polymerase subunit genes. The promoter selectivity of RNA polymerases from two sigma-subunit mutants carrying either rpoD2 or rpoD285 differed markedly from that of the respective wild-type enzymes. Both the parental RNA polymerases, however, exhibited abnormal promoter selectivity compared with holoenzymes from various wild-type E. coli strains. On the other hand, all the RNA polymerases from rpoB and/or rpoC mutants and the respective wild-type parents were similar, if not identical, in promoter selection at low temperature. At high temperature, however, RNA polymerases from mutants carrying rpoB2B7 and rpoC4, affecting the beta and beta' subunits, respectively, showed decreased transcription from the high-affinity slow-transcribable promoter rrnEp2 whereas the rpoC92 and rpoB906 X rpoC907 mutant enzymes both lost transcription activity from the strong promoter lacP(UV5). Taking all these observations together we conclude that not only the sigma subunit but also the beta and beta' subunits are involved in the recognition of promoters.

Determination of the promoter strength in the mixed transcription system. II. Promoters of ribosomal RNA, ribosomal protein S1 and recA protein operons from Escherichia coli

Using the in vitro mixed transcription system (Kajitani, M. and Ishihama, A. (1983) Nucleic Acids Res. 11, 671-686), we determined the two parameters of the promoter strength, i.e., the rate of open complex formation between RNA polymerase and promoter, and the saturation level of the open complex formation at equilibrium, for the promoters of ribosomal RNA (rrnE), ribosomal protein S1 (rpsA) and recA protein (recA) operons from Escherichia coli. Taken together with the previous determinations for lactose (lac(UV5)), tryptophan (trp) and ribosomal protein L10 (rp1J) operons, these studies revealed that the relative promoter strengths with respect to the kinetic parameter are 200, 70, 50, 40, 30, 20 and 2% of the reference promoter lacP(UV5) for recAp, rp1Jp, rpsAp3, trpP, rpsAp1, rrnEp1 and rrnEp2, respectively, under our standard reaction conditions (50 mM NaCl and 37 degrees C); and those with respect to the thermodynamic parameter are 70, 35, 20, 10, 10, 10 and 5% the level of lacP(UV5) for rrnEp2, trpP, rpsAp3, rp1Jp, rpsAp1, rrnEp1 and recAp, respectively. The order of the promoter strength, however, changes with variation of the salt concentration or reaction temperature.

Determination of the promoter strength in the mixed transcription system: promoters of lactose, tryptophan and ribosomal protein L10 operons from Escherichia coli

In vitro transcription was performed in a single reaction mixture, which contained three species of truncated E. coli DNA template, each carrying one specific promoter, lacP (UV5), trpP or rplJp, and the transcripts of distinct sizes were analyzed by electrophoresis on the same gel. Using this "mixed transcription" system, the order of the promoter strength, i.e., the capacity to form stable open complex, was determined in the single-round transcription under the standard conditions (50 mM NaCl and 37 degrees C) to be lacP greater than trpP greater than rplJp, the latter two promoters being 30--40% and 5--10% the strength of lacP, respectively. After the multiple-round transcription, however, the level of trp transcription was the lowest due to low cyclic-reaction rate but became the highest when another trp fragment containing the natural terminator was used as the template. The order of the transcription level also varied depending on the ionic strength and the reaction temperature and, as a result, lacP was no more the strongest under high salt concentration and at high temperature.