Studies on GeF4 Valence and Rydberg States by Electron Impact Spectroscopy and Ab Initio Calculations

Electron energy loss (EEL) spectra of GeF₄ have been measured with incident electrons at 100 eV for 5° scattering angle and at 30 eV for 30° scattering angle, while sweeping the energy loss over the range 7.0-18.0 eV. Low-lying excited triplet, singlet, valence, and Rydberg states are investigated and the assignments supported by quantum chemical ab initio calculations. This provides the first comprehensive investigation of all singlet and triplet excited electronic states of germanium tetrafluoride up to the first ionization energy. The Rydberg series converging to the (lowest) ionization energy limits of GeF₄ are also identified according to the magnitude of the quantum defects (δ).

Erratum to: 36th International Symposium on Intensive Care and Emergency Medicine: Brussels, Belgium. 15-18 March 2016

[This corrects the article DOI: 10.1186/s13054-016-1208-6.].

Deuterium MR in Vivo Imaging of the Rat Eye Using 2H2O

In vivo euterium MR imaging (2H MR) was investigated in rats after intraperitoneal administration of deuterated saline, and a dynamic study of the water movement in rat eyes was performed. Deuterium MR imaging was carried out by means of a gradient-echo (GRE) and a spin-echo (SE) pulse sequence. The rat eye was imaged in 2H MR more selectively by SE than by GRE, but a lower signal-to-noise ratio was obtained in 2H MR imaging using the SE sequence. The MR signal intensity of the rat eye was followed by a 3-compartment model, which enabled determination of the flow rate constant of the water in the eye (0.359/min). Deuterium MR imaging is useful to visualize the dynamic change of water in rat eyes using 2H MR at the same magnetic field (2 T) that can also be used for conventional MR imaging in humans.

Closed Rupture of the Flexor Tendons of the Little Finger Secondary to Non-Union of Fractures of the Hook of the Hamate

We report six patients with closed flexor tendon rupture affecting the little finger, occurring secondarily to non-union of the hook of the hamate bone. The ununited fragments were separated from the basal part of the hook by more than 1 mm. The fragments were also rounded and showed marginal sclerosis. Non-union was located in the middle part of the hook in three patients, the tip in two, and the base in one. At operation, the fragments were removed in all patients. Five patients were treated by free tendon grafts using three palmaris and two plantaris grafts and one underwent tendon transfer. Postoperative total range of active motion of the little finger averaged 218° (range 185–265°). All patients returned to their original employment. This series would suggest that flexor tendon rupture can occur after fracture of the hook of the hamate bone, even when the ununited fragment is small and/or rounded.

Influence of Angiotensin-converting Enzyme Genetic Polymorphism on Late Renal Dysfunction After Adult-to-adult Living-donor Liver Transplantation

BACKGROUND

Late renal dysfunction (LRD) is known to be one of the most important complications to affect long-term outcome after living-donor liver transplantation (LDLT). The relationship between angiotensin-converting enzyme insertion (I)/deletion (D) gene polymorphism and renal function after LDLT are still unknown. The aim of this study was to elucidate the risk factors for LRD after LDLT, focusing on ACE gene polymorphism.

MATERIALS AND METHODS

Among the 94 recipients who underwent adult-to-adult LDLT between March 2002 and September 2009, the total number of subjects who survived more than 1 year after LDLT and in whom angiotensin-converting enzyme genotype could be measured was 64. LRD was defined as estimated glomerular filtration rate level less than 60 mL/min/1.73 m(2) at any point after 1 year from undergoing LDLT.

RESULTS

LRD was found in 24 patients (37.5%). The incidence of LRD was significantly higher in D/D type than in I/I or I/D type: 85.7% (6/7) vs. 42.1% (8/19), 35.7% (10/38) (P = .010). Preoperative estimated glomerular filtration rate was significantly lower in D/D type than in I/I, I/D types, and postoperatively they were significantly lower in D/D type at 2, 3, and 4 years after LDLT. By multivariate analysis, age and hypertension were the independent risk factors for LRD. The 10-year survival rate was much lower in the recipients with LRD than in those without LRD at 66.7% versus 87.5%, respectively (P = .053).

CONCLUSION

In conclusion, age and hypertension were determined as significant independent risk factors for LRD after adult-to-adult LDLT, and the recipients with D/D genotype should be strictly cared for the development of LRD.

Living Donor Liver Transplantation for Biliary Atresia With Severe Preduodenal Portal Vein Stricture: Success and Pitfall of Portal Vein Reconstruction

BACKGROUND

We report a rare case of 10-month-old female who underwent living donor liver transplantation (LDLT) for syndromic biliary atresia with preduodenal portal vein (PV) and its severe stricture owing to the previous Kasai portoenterostomy. Because we successfully performed "left at right liver transplantation (LAR-LT) and graft rerotation" in this case, we are present tips and pitfalls for this operation.

METHODS

Preoperative computed tomography scan showed that her preduodenal PV was stenotic from the confluence of the superior mesenteric vein and splenic vein to hepatic hilum, which made us consider the necessity of ≥3 cm interposition vein graft to complete a safe PV anastomosis. To reduce a gap between donor and recipient's PV, we decided to put a left lateral section graft at the right subphrenic space called left-at-right liver transplantation. Thus, LDLT was performed with an identical lateral sectional graft from her father. After total hepatectomy, we implanted a graft in her right subphrenic space, and anastomosed the donor left hepatic vein to her inferior vena cava. Then, we anastomosed an interposition graft harvested from her left internal carotid vein to her PV.

RESULTS

Even after reflowing PV flow, because the duodenum compressed the interposition vein graft, PV flows were totally insufficient. Therefore, we flipped a liver graft 180° from right to left upper abdominal cavity, which could reduce the gap between PVs and acceptable PV flow was obtained.

CONCLUSIONS

In the present case, LAR-LT could reduce the distance of PVs. In addition, our rerotation method could be useful to alleviate tension on the PV anastomosis caused by preduodenal PV.

Knee extension strength and post-operative functional prediction in quadriceps resection for soft-tissue sarcoma of the thigh

Objectives

Our objective was to predict the knee extension strength and post-operative function in quadriceps resection for soft-tissue sarcoma of the thigh.

Methods

A total of 18 patients (14 men, four women) underwent total or partial quadriceps resection for soft-tissue sarcoma of the thigh between 2002 and 2014. The number of resected quadriceps was surveyed, knee extension strength was measured with the Biodex isokinetic dynamometer system (affected side/unaffected side) and relationships between these were examined. The Musculoskeletal Tumor Society (MSTS) score, Toronto Extremity Salvage Score (TESS), European Quality of Life-5 Dimensions (EQ-5D) score and the Short Form 8 were used to evaluate post-operative function and examine correlations with extension strength. The cutoff value for extension strength to expect good post-operative function was also calculated using a receiver operating characteristic (ROC) curve and Fisher’s exact test.

Results

Extension strength decreased when the number of resected quadriceps increased (p < 0.001), and was associated with lower MSTS score, TESS and EQ-5D (p = 0.004, p = 0.005, p = 0.006, respectively). Based on the functional evaluation scales, the cutoff value of extension strength was 56.2%, the equivalent to muscle strength with resection of up to two muscles.

Conclusion

Good post-operative results can be expected if at least two quadriceps muscles are preserved.

Cite this article: A. Tanaka, Y. Yoshimura, K. Aoki, M. Kito, M. Okamoto, S. Suzuki, T. Momose, H. Kato. Knee extension strength and post-operative functional prediction in quadriceps resection for soft-tissue sarcoma of the thigh. Bone Joint Res 2016;5:232–238. DOI: 10.1302/2046-3758.56.2000631.

A New Inductive Applicator for Hyperthermia

We have designed a new type of applicator for inductive heating which consists of a one-turn, square, column-like coil, through which RF current flows. The material to be heated is placed alongside one of the external sides of the coil. The depth of penetration from an applicator with a height of 20 cm, width of 20 cm, depth of 60 cm was calculated to be 11.7 cm. However, in experiments using a muscle-equivalent agar phantom 60 cm X 60 cm X 60 cm, the penetration depth proved to be 9.6 cm; but in another experiment using a smaller phantom 20 cm X 40 cm X 60 cm, the penetration depth was 6.3 cm. This means that the depth of penetration depends not only on the size of the applicator but also on the shape of the material heated. Our study clearly showed that this applicator produces much less heat in the fat layer than in the muscle layer and should be an inductive applicator suitable for deep heating cancer therapy.

On-ground detection of an electron-positron annihilation line from thunderclouds

Thunderclouds can produce bremsstrahlung gamma-ray emission, and sometimes even positrons. At 00:27:00 (UT) on 13 January 2012, an intense burst of gamma rays from a thundercloud was detected by the GROWTH experiment, located in Japan, facing the Sea of Japan. The event started with a sharp gamma-ray flash with a duration of <300 ms coincident with an intracloud discharge, followed by a decaying longer gamma-ray emission lasting for ∼60 s. The spectrum of this prolonged emission reached ∼10 MeV, and contained a distinct line emission at 508±3(stat.)±5(sys.) keV, to be identified with an electron-positron annihilation line. The line was narrow within the instrumental energy resolution (∼80keV), and contained 520±50 photons which amounted to ∼10% of the total signal photons of 5340±190 detected over 0.1-10 MeV. As a result, the line equivalent width reached 280±40 keV, which implies a nontrivial result. The result suggests that a downward positron beam produced both the continuum and the line photons.

Intestinal amoebiasis in a patient with acute graft-versus-host disease after allogeneic bone marrow transplantation successfully treated by metronidazole

Amoebiasis has rarely been reported in patients undergoing hematopoietic stem cell transplantation, although it is a world-wide infection and extremely common. We present a case of intestinal amoebiasis unexpectedly revealed by colonoscopy after allogeneic bone marrow transplantation from a human leukocyte antigen-mismatched unrelated donor for acute myeloid leukemia arising from chronic myelomonocytic leukemia and successfully treated by metronidazole.

Autofluorescence (safe) bronchoscopy and p21/ki-67 immunostaining related to carcinogenesis

Archival biopsy materials from 20 randomly selected asymptomatic volunteers from the Czech uranium miners (CZ UM) risk group (n=98) were examined for p21 and ki-67 immunostatning. There were 16 areas with normal respiratory epithelium and 22 areas with bronchial intra-epithelial neoplasia (IEN). Normal and IEN areas were identified by autofluorescence (System Autofluorescence Endoscopy, SAFE-1000) and monitored during 1998-2002. The majority of specimens from areas with normal autofluorescence intensity with ciliated columnar bronchial epithelium showed strong predominantly cytoplasmic p21 positivity. The SAFE monitoring divided areas of decreased autofluorescence intensity with early stage IEN lesions into two groups. Persistent lesions (P)-showing a spectrum of p21 cytoplasmic staining ranging from negative or isolated negativity to weak or moderate positivity combined with higher proliferative capacity proved by ki-67 nuclear staining. Disappearing lesions (D)-showing strong cytoplasmic p21 positivity and negative ki-67 staining. The IEN lesions were classified into three groups based on p21/ki-67 immunostaining: proliferative lesions at risk (R) with low or without p21 plasma immunostaining combined with high ki-67 nuclear reactivity; ambiguous lesions (A) including cases combining strong p21 cytoplasmic positivity with high ki-67 nuclear reactivity or p21 cytoplasmic negativity with ki-67 negativity staining patterns; the quiescent lesion group (Q) was characterized by strong p21 cytoplasmic positivity and negative ki-67 immunostaining.

Three percent diquafosol ophthalmic solution as an additional therapy to existing artificial tears with steroids for dry-eye patients with Sjögren's syndrome

PURPOSE

To investigate the long-term results of 3% diquafosol ophthalmic solution as an alternative therapy to existing ophthalmic solutions, including topical immunosuppression, for the treatment of dry eye in patients with Sjögren's syndrome.

METHODS

This study involved 14 female dry-eye patients (mean age: 62.4 years) with Sjögren's syndrome who insufficiently responded to their current therapy. In all patients, 3% diquafosol ophthalmic solution was administered six times daily for 12 months in substitution for artificial tears and sodium hyaluronate ophthalmic solution. Their use of corticosteroid eye drops remained unchanged from that prior to the treatment with diquafosol sodium. The subjective symptoms assessed, and ocular signs including tear meniscus radius and the tear film breakup time, and ocular-surface epithelial damage score were examined at 1, 2, 3, 4, 5, 6, 9, and 12 months after initiating treatment.

RESULTS

Among the subjective symptoms, significant improvement was obtained in dryness at 2 months post treatment, in eye fatigue at 1, 2, 3, 4, and 12 months post treatment, and in pain at 1, 2, 6, and 12 months post treatment. Difficulty in opening the eye, foreign body sensation, and redness were also significantly ameliorated at various time-points. The tear meniscus radius and the tear film breakup time were significantly improved throughout the observation period, and the corneal epithelial staining scores were significantly decreased at 3 months post treatment.

CONCLUSIONS

In dry-eye patients with Sjögren's syndrome, treatment with 3% diquafosol ophthalmic solution improved both symptoms and signs, and that effectiveness was maintained for 12 months.

Arthroscopic assistance does not improve the functional or radiographic outcome of unstable intra-articular distal radial fractures treated with a volar locking plate

There is no consensus on the benefit of arthroscopically assisted reduction of the articular surface combined with fixation using a volar locking plate for the treatment of intra-articular distal radial fractures. In this study we compared the functional and radiographic outcomes of fluoroscopically and arthroscopically guided reduction of these fractures.

Between February 2009 and May 2013, 74 patients with unilateral unstable intra-articular distal radial fractures were randomised equally into the two groups for treatment. The mean age of these 74 patients was 64 years (24 to 92). We compared functional outcomes including active range of movement of the wrist, grip strength and Disabilities of the Arm, Shoulder, and Hand scores at six and 48 weeks; and radiographic outcomes that included gap, step, radial inclination, volar angulation and ulnar variance.

There were no significant differences between the techniques with regard to functional outcomes or radiographic parameters. The mean gap and step in the fluoroscopic and arthroscopic groups were comparable at 0.9 mm (standard deviation (sd) 0.7) and 0.7 mm (sd 0.7) and 0.6 mm (sd 0.6) and 0.4 mm (sd 0.5), respectively; p = 0.18 and p = 0.35).

Arthroscopic reduction conferred no advantage over conventional fluoroscopic guidance in achieving anatomical reduction of intra-articular distal radial fractures when using a volar locking plate.

Cite this article: Bone Joint J 2015; 97-B:957–62.

A retrospective observational study to assess adverse transfusion reactions of patients with and without prior transfusion history

BACKGROUND AND OBJECTIVES

This study compares the frequency of adverse transfusion reactions (ATRs) after first transfusions with the frequency of ATRs for subsequent (non-first) transfusions.

MATERIALS AND METHODS

Five hospitals agreed to systematically collect and share 2 years of data. This was a retrospective observational analysis of data including the number of transfusion episodes and ATRs for red blood cells (RBCs), fresh frozen plasma (FFP) and platelet concentrates (PCs) given to first-time transfusion recipients and to those previously transfused.

RESULTS

First transfusion ATRs to RBCs, FFP and PCs were 1.08%, 2.84% and 3.34%, respectively. These are higher than ATR incidences to RBCs (0.69%), FFP (1.91%) and PCs (2.75%) on subsequent transfusions. Specifically, first transfusion incidences of febrile non-haemolytic transfusion reactions (FNHTRs) to RBCs (0.43%) and allergic reactions to FFP (2.51%) were higher than on subsequent transfusions (RBCs: 0.23%, FFP: 1.65%).

CONCLUSION

There are risks of ATRs on the first transfusion as well as transfusions of patients with transfusion history.

Cyclic mechanical pressure-loading alters epithelial homeostasis in a three-dimensional in vitro oral mucosa model: clinical implications for denture-wearers

Denture-wearing affects the quality and quantity of epithelial cells in the underlying healthy oral mucosa. The physiologic mechanisms, however, are poorly understood. This study aimed to compare histologic changes and cellular responses of an epithelial cell layer to cyclic mechanical pressure-loading mimicking denture-wearing using an organotypic culture system to develop a three-dimensional in vitro oral mucosa model (3DOMM). Primary human oral keratinocytes and fibroblasts were serially grown in a monolayer culture, and cell viability was measured under continuous cyclic mechanical pressure (50 kPa) for 7 days (cycles of 60 min on, 20 s off to degas and inject air). Upon initiation of an air-liquid interface culture for epithelial stratification, the cyclic pressure, set to the mode above mentioned, was applied to the 3DOMMs for 7 days. Paraffin-embedded 3DOMMs were examined histologically and immunohistochemically. In the monolayer culture, the pressure did not affect the viability of oral keratinocytes or fibroblasts. Few histologic changes were observed in the epithelial layer of the control and pressure-loaded 3DOMMs. Immunohistochemical examination, however, revealed a significant decrease in Ki-67 labelling and an increase in filaggrin and involucrin expression in the suprabasal layer of the pressure-loaded 3DOMMs. Pressure-loading attenuated integrin β1 expression and increased matrix metalloproteinase-9 activity. Incomplete deposition of laminin and type IV collagen beneath the basal cells was observed only in the pressure-loaded 3DOMM. Cyclic pressure-loading appeared to disrupt multiple functions of the basal cells in the 3DOMM, resulting in a predisposition towards terminal differentiation. Thus, denture-wearing could compromise oral epithelial homeostasis.

Clinical outcome of deep-seated atypical lipomatous tumor of the extremities with median-term follow-up study

AIMS

There is no consensus on the best surgical treatment for deep-seated atypical lipomatous tumor (ALT) of the extremities; furthermore, the appropriate duration for follow-up observation remains unclear. We investigated clinical and functional median-term outcomes in the primary operations for ALT of the extremities in order to find its best treatment methods and observation periods.

METHODS

From 1996 to 2009, we diagnosed 41 patients with deep-seated ALT of the extremities. Wide resection was performed on 11 patients and marginal resection was performed on 30 patients. The minimum follow-up was 5 years (median, 8.5; range, 5-17.4). Patients were evaluated for their local recurrence, dedifferentiation, and post-operative function using the ISOLS/MSTS scoring system.

RESULTS

Recurrence and dedifferentiation rates were both 0% for the wide resection group, while the rates were 23% (7/30) and 3% (1/30) for the marginal resection group, respectively. Median duration before recurrence was 7.2 years (range, 4.0-14.2). Local recurrence-free survival rate was significantly higher in the wide resection group (P = 0.013). In the marginal resection group, 10% (3/30) of the cases showed residual tumor. The localization of these tumors was all intermuscular. The ISOLS/MSTS scores were 98% (range, 90-100) for wide resection and 99% (range, 93-100) for marginal resection, with no statistical difference (P = 0.694). No ALT-related deaths occurred during the observation period.

CONCLUSIONS

In addition to long-term (at least 8 years) of continuous observation, a wide resection is necessary in order to prevent recurrence, dedifferentiation, and residual tumor.

BF3 valence and Rydberg states as probed by electron energy loss spectroscopy and ab initio calculations

In this contribution we probe BF3 low-lying excited singlet states measured at 100 eV, 2.8° scattering angle and triplet states at 40 eV, 40° scattering angle, while sweeping the energy loss over the range 10.0-20.0 eV. The electronic state spectroscopy has been investigated and the assignments supported by quantum chemical calculations. This provides the first comprehensive investigation of all singlet and triplet excited electronic states of boron trifluoride up to the first ionization potential. A generalized oscillator strength analysis is employed to derive oscillator strength f0 value and integral cross sections (ICSs) from the corresponding differential cross sections (DCSs). The f0 value is compared with the optical oscillator strength (OOS) from photoabsorption, and the unscaled Born ICSs are then compared with relevant energy and binary-encounter and f-scaled Born cross section (BEf-scaling) results determined as a part of this investigation. The lowest n members of the Rydberg series have been assigned as converging to the lowest ionization energy limits of boron trifluoride and classified according to the magnitude of the quantum defects (δ).

Biochemical indicators of implantation success of tissue-engineered oral mucosa

Real-time (RT) determination of the health of in vitro tissue-engineered constructs prior to grafting is essential for prediction of success of the implanted tissue-engineered graft. In addition, the US Food and Drug Administration requires specific release criteria in RT prior to the release of tissue-engineered devices for human use. In principle, assessing the viability and functionality of the cellular component can be achieved by quantifying the secretion of growth factors and chemokines of tissue-engineered constructs. Ex vivo-produced oral mucosa equivalents (EVPOMEs) were fabricated under thermally stressed conditions at 43 °C for 24 h to create a functionally compromised EVPOME. We used microchannel enzyme-linked immunosorbent assay to evaluate the functionality of the cellular component, oral keratinocytes, of stressed and unstressed EVPOMEs by measuring the release of vascular endothelial growth factor (VEGF), interleukin-8 (IL-8), human β-defensin 1 (hBD-1), and tissue inhibitor of metalloproteinase 1 and 2 (TIMP-1 and -2) into the spent medium, which was collected on the same day prior to graft implantation into severe combined immunodeficiency mice. Implanted EVPOMEs' histology on the seventh postimplantation day was used to correlate outcomes of grafting to secreted amounts of IL-8, hBD-1, VEGF, TIMP-1, and TIMP-2 from corresponding EVPOMEs. Our findings showed that significantly higher levels of IL-8, hBD-1, and TIMP-2 were secreted from controls than from thermally stressed EVPOMEs. We also found a direct correlation between secreted VEGF and IL-8 and blood vessel counts of implanted EVPOMEs. We concluded that measuring the constitutive release of these factors can be used as noninvasive predictors of healthy tissue-engineered EVPOMEs in RT, prior to their implantation.

Elastic differential cross sections for C₄F₆ isomers in the 1.5-200 eV energy electron impact: similarities with six fluorine containing molecules and evidence of F-atom like scattering

We report absolute elastic differential cross sections for electron interactions with the C4F6 isomers, hexafluoro-1,3-butadiene (1,3-C4F6), hexafluoro-2-butyne (2-C4F6), and hexafluorocyclobutene (c-C4F6). The incident electron energy range is 1.5-200 eV, and the scattered electron angular range for the differential measurements varies from 15° to 150°. In all cases the absolute scale of the differential cross section was set using the relative flow technique, with helium as the reference species. Atomic-like behaviour in these scattering systems is shown here for the first time, and is further investigated by comparing the elastic cross sections for the C4F6 isomers with other fluorinated molecules, such as SF6 and CnF6 (n = 2, 3, and 6). We note that for all the six-F containing molecules, the scattering process for electron energies above 30 eV is indistinguishable. Finally, we report results for calculations of elastic differential cross sections for electron scattering from each of these isomers, within an optical potential method and assuming a screened corrected independent atom representation. The level of agreement between these calculations and our measurements is found to be quite remarkable in all cases.

5-hydroxytryptamine- and dopamine-releasing effects of ring-substituted amphetamines on rat brain: a comparative study using in vivo microdialysis

Using in vivo microdialysis, a comparative study was conducted to examine the effects of amphetamine-related compounds (methamphetamine, MAP; 3,4-methylenedioxymethamphetamine, MDMA; p-methoxyamphetamine, PMA; p-methoxymethamphetamine, PMMA; 4-methylthioamphetamine, 4-MTA; 3,4,5-trimethoxyamphetamine, TMA; 2,5-dimethoxy-4-iodoamphetamine, DOI) on extracellular levels of serotonin (5-HT) and dopamine (DA). Dialysates were assayed using HPLC equipped with electrochemical detector following i.p. administration with each drug at a dose of 5 mg/kg. MAP was found to drastically and rapidly increase 5-HT and DA levels (870% and 1460%, respectively). PMA, PMMA, and 4-MTA slightly increased DA levels (150-290%) but remarkably increased 5-HT levels (540-900%). In contrast, TMA and DOI caused no detectable changes in levels of both monoamines. We observed that the potent DA-releasing action of MAP was remarkably decreased by introduction of methoxy or methylthio group at the para position (MAP vs. PMMA or 4-MTA), but introduction of two additional adjacent methoxy groups into PMA totally abolished its 5-HT-/DA-releasing action (PMA vs. TMA). In addition, para-mono-substituted compounds inhibited both monoamine oxidase (MAO) enzymes more strongly than other compounds; PMA and 4-MTA exhibited submicromolar IC50 values for MAO-A. On the other hand, TMA scarcely affected the activity of both MAO enzymes as well as extracellular levels of 5-HT and DA. In this comparative study, MDMA, PMA, and 4-MTA functioned similar to PMMA, a typical empathogen; these findings therefore could be helpful in clarifying the psychopharmacological properties of amphetamine-related, empathogenic designer drugs.

Overexpression and Purification of Asparagine Synthetase fromEscherichia coli

Overexpression of the asnA gene from Escherichia coli K-12 coding for asparagine synthetase (EC 6.3.1.1) was achieved with a plasmid, pUNAd37, a derivative of pUC18, in E. coli. The plasmid was constructed by optimizing a DNA sequence between the promoter and the ribosome binding region. The enzyme, comprising ca. 15% of the total soluble protein in the E. coli cell, was readily purified to apparent homogeneity by DEAE-Cellulofine and Blue-Cellulofine column chromatographies. The amino-terminal sequence, amino acid composition, and molecular weight of the purified protein agreed with the predicted values based on the DNA sequence of the gene. Furthermore the native molecular weight measured by gel filtration confirmed that asparagine synthetase exists as a dimer of identical subunits.