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Çalışmada 49 yazar bulunmaktadır. Bu yazarlardan sadece Bursa Uludağ Üniversitesi mensuplarının girişleri yapılmıştır. The emergence of the COVID-19 pandemic has severely affected medical treatment protocols throughout the world. While the pandemic does not affect hand surgeons at first glance, they have a role to play. The purpose of this study was to describe the different measures that have been put in place in response to the COVID-19 pandemic by hand surgeons throughout the world. The survey comprised 47 surgeons working in 34 countries who responded to an online questionnaire. We found that the protocols varied in terms of visitors, health professionals in the operating room, patient waiting areas, wards and emergency rooms. Based on these preliminary findings, an international consensus on hand surgery practices for the current viral pandemic, and future ones, needs to be built rapidly. (C) 2020 SFCM. Published by Elsevier Masson SAS. All rights reserved.

Background Early studies from US and Europe have reported that female out-of-hospital cardiac arrest (OHCA) patients were less likely to receive bystander cardiopulmonary resuscitation (CPR). However, little is known about sex-related difference in receiving CPR and clinical outcome among adult OHCA patients in Japan. Methods This study was a nation-wide, population-based observational study of OHCA in Japan from 2011 to 2015. We included all adult cardiogenic OHCA patients. We excluded patients witnessed by emergency medical services (EMS) from the present analysis. To account for the age-related difference, we stratified by age category: 18–39, 40–64, 65–79, and ≥80. To examine the association between patient sex and neurological outcome at 30-day, we fitted multivariable logistic regression model with adjustment for age, bystander CPR status, first document rhythm, dispatcher instruction and EMS response time. Results There were 339,317 adult cardiogenic, not EMS-witnessed OHCA patients (median age, 80; female, 43.5%) in Japan from 2011 to 2015. Overall, 171,122 (50.4%) received CPR by citizen, 34,283 (10.1%) had initial shockable rhythm, and 11,421 (3.4%) had favorable neurological status at 30-day. Female patients were more likely to receive bystander CPR (vs. male; 53.8% vs. 47.8%), and were less likely to have initial shockable rhythm (5.2% vs. 13.9%) and favorable neurological status at 30-day (1.8% vs. 4.6%) (all; p Sex difference in bystander CPR Overall Male (n=191,672) Female (n=147,645) p-value All (n=339,317) 50.4% 47.8% 53.8% OR for neurological outcome at 30-day Conclusion Unlike the situation in Europe and US, female OHCA patients, especially elderly female, were more likely to receive bystander CPR in Japan. However, female patients had worse clinical outcome after OHCA. Further investigations including in-hospital treatment are needed to clarify the sex-difference in clinical outcome after OHCA. Acknowledgement/Funding None

The aim of this study was to establish the feasibility of microsurgical end-to-side vascular anastomosis with a multiclamp adjustable vascular clamp prototype in an inert experimental model. Our method consisted of performing an end-to-side microsurgical anastomosis with 10/0 suture on a 2-mm diameter segment. In group 1, the end-to-side segment was held in place by a double clamp and a single end clamp. In group 2, the segment was held in place with a single multiclamp adjustable clamp. The average time for performing the anastomosis was shorter in group 2. The average number of sutures was the same in both groups. No leak was found and permeability was always positive in both groups. Our results show that performing end-to-side anastomosis with a multiclamp adjustable vascular clamp is feasible in an inert experimental model. Feasibility in a live animal model has to be demonstrated before clinical use.

Minimally invasive plate osteosynthesis (MIPO) has been used in recent years to treat fractures of the distal radius with volar locking plates. Its advantages are the preservation of the pronator quadratus and good esthetics. The MIPO technique was described originally with two incisions: one distal transverse or longitudinal incision and one proximal longitudinal incision. The trend is now to use a single longitudinal incision less than 20mm long. Functional and radiological outcomes are comparable to those of conventional techniques. The MIPO technique is indicated for extra-articular and intra-articular fractures. Arthroscopy may be used concurrently in the latter case. When the distal radius fracture is associated with a proximal shaft fracture, a double incision is needed to introduce a longer plate. The relative contraindications of the MIPO technique are comminuted intra-articular fractures in osteoporotic elderly patients. If reduction is problematic, a larger incision can easily be made.

The aim of this work was to identify the websites of the members of the French Society for Hand Surgery, examine the container and the content, and propose a common code of ethics. The census of Websites of the French Society for Hand Surgery Internet members was obtained through a survey questionnaire with 17 items online on the mode of exercise of the surgeon and the website itself. Forty-six out of 568 members of the SFCM responded to the questionnaire: 9 junior members, 6 associate members and 31 full members. A total of 12.5 % had the HONcode certification. They included educational materials for patients in 80.95 % of non-urgent conditions, and 68.42 % of emergency. Answers to questions about attendance and the cost of maintenance of websites were unusable. It would be interesting to create a specific code of ethics for hand surgery, free, certified by the SFCM, in partnership with the High Authority in Health (HAS, in French).

We report observation of the paramagnetic Faraday rotation of spin-polarized ytterbium (Yb) atoms. As the atomic samples, we used an atomic beam, released atoms from a magneto-optical trap (MOT), and trapped atoms in a far-off-resonant trap (FORT). Since Yb is diamagnetic and includes a spin-1/2 isotope, it is an ideal sample for the spin physics, such as quantum non-demolition measurement of spin (spin QND), for example. From the results of the rotation angle, we confirmed that the atoms were almost perfectly polarized., Comment: 8 pages, 20 figures

Ultra shallow dopant profiles of arsenic implanted into Si with an energy range from 0.5 to 3 keV to a dose of 8 × 1014 ions/cm2 with and without spike annealing were measured by medium energy ion scattering (MEIS) with a toroidal electrostatic analyzer (TEA). A shift of the peak of arsenic profile to the surface after spike annealing was observed by MEIS measurement. Most of the implanted arsenic atoms were trapped in the native oxide layer after spike annealing. A recovery of silicon crystal defects induced by arsenic implantation was observed after spike annealing by glancing angle Rutherford back scattering (RBS) measurement with a solid-state detector. The thickness of disordered Si layers down to 1.5 nm was evaluated from glancing angle RBS measurements for implanted sample before and after spike annealing.

Medium energy ion scattering (MEIS) combining a toroidal electrostatic analyzer with an energy resolution (dE/E) of 4 × 10−3 has been used for ultra-shallow depth profiling of As implanted into Si at 1, 2 and 5 keV to a dose of 1.2 × 1015 ions/cm2 before and after spike annealing at 1075 °C. Depth profiling results extracted from MEIS spectra were compared with those of simulation and SIMS measurement. The arsenic re-distribution close to the surface after spike annealing was found by MEIS and SIMS measurements.

Samples of compositions, RuSr2GdCu2O8−δ (Ru-1212) and RuSr2Gd1.5Ce−0.5Cu2O10−δ (Ru-1222), were synthesised through solid-state reaction routes. The former crystallized in the space group P4/mmm and the latter in I4/mmm. The magnetization vs. temperature curve measured in 5-Oe field showed a clear branching into zero-field-cooled (ZFC) and field-cooled (FC) curves for Ru-1212 and Ru-1222, respectively, around 140 and 100 K with a cusp at 135 and 80 K and a diamagnetic transition around 20 and 30 K only in the ZFC branch. The two down-turn cusps at 135 and 80 K may be attributed to the antiferromagnetic nature of Ru spins. The isothermal magnetization possessed a non-linear contribution due to a ferromagnetic component at low temperatures below 50 K for both samples. The resistance vs. temperature behaviour of the Ru-1212 samples in applied fields of 0, 3 and 7 T confirmed superconductivity, exhibiting a different type of broadening of the superconductivity transition under magnetic fields from that known for conventional high-Tc superconductors. The magnetoresistance (MR) was negative above the Ru magnetic ordering temperature at 135 K. Below the Ru magnetic ordering temperature MR displayed a positive peak at low fields and became negative at higher fields for Ru-1212. For Ru-1222 MR remained negative both above and below the ordering temperature. A maximum of 2% was observed for the negative MR value at the Ru magnetic ordering temperature. An electron diffraction (ED) pattern from the Ru-1212 sample showed two types of superstructure: one has a weak spot at the centre of the a ∗ –b ∗ rectangle, and the other at the center of the b ∗ edge only. The latter indicates that either Ru/Cu or vacancy ordering of 2b periodicity takes place along the b-direction. Interestingly, Ru-1222 showed only ED patterns with clean a ∗ –b ∗ and a ∗ –c ∗ planes without any superspots.

In 2008 we published the first set of guidelines for standardizing research in autophagy. Since then, research on this topic has continued to accelerate, and many new scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Accordingly, it is important to update these guidelines for monitoring autophagy in different organisms. Various reviews have described the range of assays that have been used for this purpose. Nevertheless, there continues to be confusion regarding acceptable methods to measure autophagy, especially in multicellular eukaryotes. A key point that needs to be emphasized is that there is a difference between measurements that monitor the numbers or volume of autophagic elements (e.g., autophagosomes or autolysosomes) at any stage of the autophagic process vs. those that measure flux through the autophagy pathway (i.e., the complete process); thus, a block in macroautophagy that results in autophagosome accumulation needs to be differentiated from stimuli that result in increased autophagic activity, defined as increased autophagy induction coupled with increased delivery to, and degradation within, lysosomes (in most higher eukaryotes and some protists such as Dictyostelium) or the vacuole (in plants and fungi). In other words, it is especially important that investigators new to the field understand that the appearance of more autophagosomes does not necessarily equate with more autophagy. In fact, in many cases, autophagosomes accumulate because of a block in trafficking to lysosomes without a concomitant change in autophagosome biogenesis, whereas an increase in autolysosomes may reflect a reduction in degradative activity. Here, we present a set of guidelines for the selection and interpretation of methods for use by investigators who aim to examine macroautophagy and related processes, as well as for reviewers who need to provide realistic and reasonable critiques of papers that are focused on these processes. These guidelines are not meant to be a formulaic set of rules, because the appropriate assays depend in part on the question being asked and the system being used. In addition, we emphasize that no individual assay is guaranteed to be the most appropriate one in every situation, and we strongly recommend the use of multiple assays to monitor autophagy. In these guidelines, we consider these various methods of assessing autophagy and what information can, or cannot, be obtained from them. Finally, by discussing the merits and limits of particular autophagy assays, we hope to encourage technical innovation in the field. © 2012 Landes Bioscience.

This study evaluated a typing method of O26:H11 enterohaemorrhagic and enteropathogenic Escherichia coli (EHEC and EPEC) based on the variation in genomic location and copy numbers of IS621.Two multiplex PCRs, targeting either the left (5') or right (3') IS/chromosome junction of 12 IS621 insertion sites and one PCR specific of another truncated copy, were developed. Thirty-eight amplification profiles were observed amongst a collection of 69 human and bovine O26:H11 EHEC and EPEC. Seventy-one per cent of the 45 EHEC and EPEC with identical IS621 fingerprints within groups of two, three or four isolates had85% pulsed field gel electrophoresis (PFGE) profile similarity, including four groups of epidemiologically related EHEC or EPEC, while most of the groups had85% similarity between each others. Epidemiologically related EHEC from each of three independent outbreaks in Japan and Belgium also exhibited identical IS621 fingerprints and PFGE profiles.The IS621 fingerprinting and the PFGE are complementary typing assays of EHEC and EPEC; though, the former is less discriminatory.The IS621 printing method represents a rapid (24 h) first-line surveillance and typing assay, to compare and trace back O26:H11 EHEC and EPEC during surveys in farms, multiple human cases and outbreaks.

This paper discusses the aftertreatment techniques for particulates and NO x , the noxious components of diesel exhaust gas. Three aftertreatment techniques for particulates, i.e. a trap system, a catalyzed trap system and use of a flow-through type SOF (soluble organic fraction) decomposing catalyst, are compared. For the modified diesel engines of the '90s, the flow-through type SOF decomposing catalyst is shown to overcome regulations. This paper further discusses NO x reducing techniques.

Increasing rate of breast cancer in Japan is enormous in these years. Nevertheless only 2–3 % of female may receive mammography. In order to improve this number for early detection of breast cancer we have started development of a refraction‐based visualization of breast cancer. This system comprises two types of imaging: one is for a regular annual or biyearly check of the breast cancer. This is a 2‐D mode x‐ray dark‐field imaging where a Laue transmission type of angle analyzer with thickness of 2.124 mm is used for the FOV of 90 mm × 90 mm that can provide the spatial resolution better than 50 microns; the other a 3‐D reconstruction for further detailed check to specify type and location of breast cancer.

We propose a new method of spin squeezing of atomic spin, based on the interactions between atoms and off-resonant light which are known as paramagnetic Faraday rotation and fictitious magnetic field of light. Since the projection process, squeezed light, or special interactions among the atoms are not required in this method, it can be widely applied to many systems. The attainable range of the squeezing parameter is S^{-2/5}, where S is the total spin, which is limited by additional fluctuations imposed by coherent light and the spherical nature of the spin distribution., 4 pages,6 figures

Ultra shallow arsenic profiles implanted into Si with an energy range from 0.5 to 3 keV to a dose of 8/spl times/10/sup 14/ ions/cm/sup 2/ before and after spike annealing were measured by medium energy ion scattering (MEIS) with a toroidal electrostatic analyzer (TEA). A shift of the peak of arsenic profile to the surface after spike annealing was observed by MEIS measurement. Most of the implanted arsenic atoms were trapped in the native oxide layer after spike annealing.

We report the development of a fast pulse polarimeter for the application to quantum non-demolition measurement of atomic spin (Spin QND). The developed system was tunable to the atomic resonance of ytterbium atom and has narrow laser linewidth suitable for spin QND. Using the developed polarimeter, we successfully demonstrated the measurement of the vacuum noise, with 10^6 to 10^7 photon number per pulse., Comment: 4 pages, 7 figures

Medium Energy Ion Scattering (MEIS) using a toroidal electrostatic analyzer (TEA) with an energy resolution (/spl Delta/E/E) of 4 x 10/sup -3/ has been used for ultra-shallow depth profiling of As implanted in Si at 1-5 keV to a dose of 1.2 /spl times/ 10/sup 15/ ions/cm/sup 2/ before and after RTA and spike annealing. Depth profiling results extracted from MEIS spectra were compared with those of simulation and SIMS measurement. The arsenic re-distribution close to the surface after spike annealing was found by MEIS and SIMS measurements.

The minimum feature size of integrated circuits shrinks rapidly, which requires analysis with an enhanced depth resolution of dopants in their shallow source-drain regions and their extensions. Rutherford backscattering spectroscopy (RBS) combining a medium energy ion scattering (MEIS) with a detector of improved energy resolution provides the depth resolution or 2.4 4.0 nm at a depth of 10 - 20 nm. Arsenic ions were implanted into Si at 5 keV to a dose of 1 t 1015 ions/cm2 and annealed by rapid thermal annealing (RTA) at 1050dC for 5 s. Depth profiling results using MEIS were compared with those of secondary ion mass spectroscopy (SIMS) and glancing angle RBS by MeV energy He ions.

We have developed a new method of breast resection margin assessment in quadrantectomy using an adjustable mould to prevent the three-dimensional specimen from distorting during fixation.The new method has been applied to 10 consecutive quadrantectomies (six invasive duct carcinomas, four duct carcinoma in situ with or without microinvasion). The precise configuration of the fixed specimen enabled pathologists to examine the side slices, the 5 mm thick slices cut parallel to the flat lateral margins of the specimen, permitting the separation of margin evaluation from tumour characterization. Eight cases with negative margins by our method would also be negative by assessment of inked margins since the margin widths were estimated to be from 5 to 30 mm (average 16.3 mm); two cases with positive margins would also be positive by inked margins.Our new method was as reliable as the inked margins employing sequential slicing of the entire tissue, although it reduced the number of blocks by more than half in invasive carcinomas. A further advantage of this method is that the accuracy in margin evaluation is not influenced by the extent of tumour sampling. In addition, our system can pinpoint the positive margins facilitating re-excision to obtain tumour-free margins.

To investigate the alterations of genetic instabilities in carcinogenesis of the breast, we analyzed the allelotypic profile of 65 ductal carcinomas in situ (DCIS), compared with that of 207 invasive ductal carcinomas (IDC) of the breast. These studies were performed by means of examining microsatellite-length polymorphisms at seven loci (AluVpa, ESR, D11S988, D13S267, D16S398, D17S1159, and D17S855) from microdissected paraffin sections. Allelic loss or imbalance, considered a loss of heterozygosity (LOH), tended to be more frequently seen in IDC than in DCIS. In particular, the frequency of LOH at the 17p locus was significantly higher in IDC than in DCIS (42 vs. 23%, P=0.022). LOH in DCIS was most frequently seen at D16S398 (26%). LOH frequency at D16S398 in low- and intermediate-grade DCIS was higher than that in high-grade DCIS, while LOH frequencies at D11S988 and D17S1159 in low- and intermediate-grade DCIS was lower than those in high-grade DCIS. LOH frequency at D11S988 in non-comedo type DCIS was lower than that in comedo type DCIS. Furthermore, the frequency of microsatellite instability (MSI) at only one locus in DCIS (28%) was statistically higher than that in IDC (6%) (P

Although the localization of S100 protein in breast carcinoma has previously been studied, the immunohistochemical expression of the S100-alpha and -beta subunits has not been examined.Immunohistochemical staining for S100-alpha and S100-beta proteins was performed on 72 benign breast lesions and 72 infiltrating ductal carcinoma of the breast. Noncross-reactive anti-S100-alpha and anti-S100-beta antibodies purified by affinity chromatography were used in the studies.More than 30% of the epithelial cells comprising all the benign lesions were either S100-alpha or S100-beta positive. In breast carcinoma cases, however,30% of malignant cells were S100-alpha positive in 70/72 cases (97.2%), whereas the number of S100-beta positive cells exceeded 30% in only 3/72 cases (4.0%).Immunohistochemical staining for S 100-alpha and S100-beta proteins may help to differentiate benign proliferative breast lesions from breast cancers in difficult cases.

We report an autopsy case of pulmonary hypertension associated with systemic lupus erythematosus in a 48-year-old woman. After 8-year follow-up under a definite diagnosis of systemic lupus erythematosus, she experienced gradually developing exertional dyspnea with palpitation. Her chest x-ray showed clear lung fields with marked cardiac enlargement. A right cardiac catheterization revealed a pulmonary arterial pressure of 74/30 mm Hg (mean: 47). She was treated with repeated plasmapheresis, oral corticosteroid, and immunosuppressant without improvement, and she died suddenly, 23 days after admission. Pathological examination revealed that small pulmonary arteries and arterioles were diffusely involved by florid thrombotic lesions, which were characterized by intimal eccentric fibrous thickening, luminal occlusion with recanalization, and occasional fresh thrombi. In addition, some arteries showed plexiform lesions coexistent with intimal thrombotic lesions. Concentric laminar intimal fibrosis was not seen. No significant parenchymal change was seen. Our study not only adds a rare case of thrombotic pulmonary hypertension associated with systemic lupus erythematosus, but also suggests that plexiform lesions can occur in association with thrombotic arteriopathy.

A case of small cell carcinoma of the stomach is reported. A 53-year-old male was referred to our hospital for elective surgery for gastric cancer. Pre-operative examinations revealed no metastases. Gastrectomy was performed curatively, and there were no gross findings of metastases. Histologically, the tumor was composed of intermediate-sized cells with hyper-chromatic nuclei and scanty cytoplasm. These cells were argyrophilic and positive for chromogranin A. A small portion of the tumor consisted of conventional adenocarcinoma (signet ring cell carcinoma and tubular adenocarcinoma). No lymph node metastasis was observed microscopically. However, 7 months after the operation, splenic and hepatic metastases were detected, and the patient died very soon thereafter. Small cell carcinoma of the stomach is a very rare disease. In literature, only 15 cases have been cured surgically. Among them, only one case had been diagnosed as small cell carcinoma before the operation, which suggests the difficulty of pre-operative diagnosis. The prognosis of this disease is very poor compared with the common type of gastric carcinoma. Considering the poor prognosis of this particular disease, adjuvant chemotherapy might be mandatory in all cases even if surgically curative resection is performed.

The aim of this study was to clarify that the depressed mechanoenergetics in patients with idiopathic dilated cardiomyopathy (DCM) resulted from compensation for the decreased contractility. The study population consisted of eight control subjects, with normal left ventricular size and ejection fraction and 31 patients with DCM. Left ventricular end-systolic elastance (Ees), effective arterial elastance (Ea), external work (EW), and the pressure-volume area (PVA) were measured, using a dual-field volume conductance catheter equipped with a micromanometer-tipped catheter. Ea/Ees was evaluated as ventriculoarterial coupling. Normal hearts worked at almost optimal condition (defined as Ea/Ees = 1/2), while ventriculoarterial coupling was far from the optimum (EaEes) in patients with DCM. Ees in patients with DCM was less than that in control subjects; however, Ea was similar in the two groups. The mismatch of Ea/Ees observed in DCM leads to depressed mechanoenergetics as a result of the compensatory response to maintain adequate blood pressure. Volume enlargement plays an important role in maintaining adequate blood pressure and cardiac output in the course of chronic deterioration of contractility.

A case of primary sclerosing cholangitis (PSC) successfully treated with cyclosporine is described. A 65-year-old man who presented with jaundice and anemia was diagnosed as having PSC, accompanied by pancreatic duct abnormalities. Cholangiography and pancreatography showed marked improvements following combined therapy with cyclosporine and methylprednisolone. Cyclosporine seems to be a promising drug for the treatment of patients with PSC. This report reasons that the same disease process affects both the pancreatic ducts and the bile ducts, and that stagnation of pancreatic juice may have a role to play in the pancreatic duct abnormalities.

To elucidate the role of a flexible loop in the stability and function of Escherichia coli dihydrofolate reductase, glycine-121 in a flexible loop (residues 117-131), separated by 19 A from active site Asp27, was substituted by site-directed mutagenesis with eight amino acids (Ala, Val, Leu, Asp, Ser, Cys, Tyr, and His). The free energy change of unfolding decreased in the order of G121AG121DG121CG121S, wild-typeG121HG121YG121LG121V. The thermal denaturation temperature decreased with all mutations, accompanied by a decrease in the calorimetric enthalpy of denaturation. The steady-state kinetic parameter for the enzyme reaction, Km, was only slightly influenced, but kcat was significantly decreased by the mutations, there being 3- (G121C) to 42-fold (G121L) decreases in kcat/Km compared to that of the wild-type enzyme. The effects of mutations on the stability and enzyme activity were statistically examined as a function of the hydrophobicity and volume of amino acids introduced. The diminished stability and activity with increases in the hydrophobicity and volume of amino acids suggest that the main effect of the mutations would be modification of the flexibility of the loop due to overcrowding of the bulky side chains, overcoming the enhancement of the hydrophobic interaction.

Pravastatin sodium, a newly developed potent synthesis inhibitor of HMG-CoA (beta-hydroxy-beta-methylglutaryl-cocarboxylase-A) reductase (Sankyo Co., Ltd., Japan) was medicated, 10 approximately 15 mg/day (mean: 11.1 mg/day) for 10.2 weeks in mean, in 14 patients with primary hyperlipoproteinemia of more than 230 mg/dl of serum cholesterol levels (mean age: 56.9 y.o.). The values of serum cholesterol decreased (from 242 +/- 12 to 207 +/- 22; mg/dl), and of high density lipoprotein (HDL) increased (from 42.3 +/- 8.8 to 45.3 +/- 9.2; mg/dl) significantly (p0.05, respectively) 10.2 weeks in mean after medication with pravastatin sodium. The whole blood viscosity, at every shear rate examined, corrected blood viscosity, for the standard hematocrit level of 45%, and plasma fibrinogen decreased significantly (p0.05, respectively) at the same time, without showing significant differences any more 10.2 weeks in mean after medication with those in 14 elderly normal subjects (mean age: 56.7 y.o.), which suggested that the hemorheological parameters in patients with primary hyperlipoproteinemia had improved significantly by medication with pravastatin sodium.

Magnetization vs temperature behavior of RuSr 2 GdCu 2 O 8−δ (Ru-1212) measured in an field of 5 Oe, shows a clear branching of zero-field-cooled (ZFC) and field-cooled (FC) curves around 140 K, a cusp at 135 K, and a diamagnetictransition around 20 K (in the ZFC branch). The cusp at 135 K is due to the antiferromagnetic ordering of the Ru moments. The magnetization-field isotherms, below 50 K, show a nonlinear contribution from a ferromagnetic component. The resistance vs temperature behavior of the compound, in applied fields of 0, 3, and 7 T, confirms that the sample is superconducting at around 20 K. The superconducting transition exhibits field broadening of a type different than that known for conventional high T c superconductors. The magnetoresistance(MR) is negative above the Ru magnetic orderingtemperature of 135 K, while below this temperature,MR displays a positive peak in low fields and becomes negative in higher fields. A maximum of 2% is observed for the negative MR value at the Ru magnetic orderingtemperature. An electron diffraction pattern obtained for this Ru-1212 sample shows two types of superstructure; one with a weak spot at the center of the a–b rectangle and the other only along the b direction. It is possible that either Ru/Cu or Ru 4+ / Ru 5+ ordering of 2b periodicity takes place along the b direction.

Clones carrying a gene causing overproduction of protease IV, a signal peptide peptidase of Escherichia coli, were isolated from the Clarke and Carbon's collection. Restriction mapping analysis revealed that pLC7-10 and pLC40-13, thus isolated, shared the same chromosomal DNA region. The 2.3-kilobase RsaI-SalI fragment in this region, which was found to carry the gene, was subjected to nucleotide sequence determination. Only one long open reading frame was found. The hypothetical polypeptide sequence deduced from the DNA sequence has a molecular mass of 67,241 daltons. The putative gene was named sppA. Protease IV was purified to homogeneity from the cytoplasmic membrane of an overproducing strain harboring a sppA gene-carrying plasmid. The purified enzyme gave a single polypeptide band of 67,000-dalton molecular mass on sodium dodecyl sulfate-polyacrylamide gel. This molecular mass and the amino acid composition of the purified enzyme were consistent with the deduced primary structure of the sppA gene product. The molecular mass thus determined was almost twice as large as that previously reported by Pacaud (Pacaud, M. (1982) J. Biol. Chem. 257, 4333-4339). A cross-linking study revealed that protease IV is a tetramer of the polypeptide. From these results, we conclude that protease IV is a tetramer of the sppA gene product.

During export of the outer membrane lipoprotein across the cytoplasmic membrane, the signal peptide of the lipoprotein undergoes two successive proteolytic attacks, cleavage of the signal peptide by signal peptidase and digestion of the cleaved signal peptide by an enzyme called signal peptide peptidase(s) (Hussain, M., Ichihara, S., and Mizushima, S. (1982) J. Biol. Chem. 257, 5177-5182; Hussain, M., Ozawa, Y., Ichihara, S., and Mizushima, S. (1982) Eur. J. Biochem. 129, 233-239). Here we report that protease IV, a cytoplasmic membrane protease, exhibits the signal peptide peptidase activity. The signal peptide peptidase activity was cofractionated with protease IV throughout the entire process of purification of the latter enzyme. Only the signal peptide was digested by the peptidase among membrane proteins. Both the signal peptide peptidase activity and the protease IV activity were inhibited to similar degrees by antipain, leupeptin, chymostatin, and elastatinal that are known to inhibit the signal peptide peptidase activity in the cell envelope. From these results we conclude that protease IV is the signal peptide peptidase that is responsible for signal peptide digestion in the cytoplasmic membrane. The peptidase attacked the signal peptide only after its release from the precursor protein.

The energy requirement for protein translocation across membrane was studied with inverted membrane vesicles from an Escherichia coli strain that lacks all components of F1F0-ATPase. An ompF-lpp chimeric protein was used as a model secretory protein. Translocation of the chimeric protein into membrane vesicles was totally inhibited in the presence of carbonyl cyanide m-chlorophenylhydrazone (CCCP) or valinomycin and nigericin and partially inhibited when either valinomycin or nigericin alone was added. Depletion of ATP with glucose and hexokinase resulted in the complete inhibition of the translocation process, and the inhibition was suppressed by the addition of ATP-generating systems such as phosphoenolpyruvate-pyruvate kinase or creatine phosphate-creatine kinase. These results indicate that both the proton motive force and ATP are required for the translocation process. The results further suggest that both the membrane potential and the chemical gradient of protons (delta pH), of which the proton motive force is composed, participate in the translocation process.

The OmpR protein is a positive regulator involved in osmoregulatory expression of the ompF and ompC genes, which respectively code for major outer membrane proteins OmpF and OmpC of Escherichia coli. The OmpR protein has been purified to homogeneity from an overproducing strain harboring an ompR gene-carrying plasmid. Throughout the purification the OmpR protein behaved as a single entity. The molecular weight determined on sodium dodecyl sulfate-polyacrylamide gel, the total amino acid composition, and the NH2-terminal amino acid sequence of the purified protein were essentially the same as those deduced from the nucleotide sequence of the ompR gene. Molecular weight determination and cross-linking study on the native protein revealed that the purified protein exists as a monomer. The purified OmpR protein was specifically bound to the promoter regions of the ompC and ompF genes. Experiments with a series of upstream deletions of the ompC and ompF promoters revealed that the region upstream from the -35 region was indispensable for OmpR binding to both the ompC and the ompF promoters. Although it has been proposed that depending on the medium osmolarity the OmpR protein may exist in two alternative structures, which respectively regulate functioning of the ompC and the ompF promoters, the purified OmpR protein appeared to be homogeneous and interacted with both promoters to the same extent.

By labeling cells heavily with [3H]glycerol or [3H]-palmitic acid several new species of lipoproteins, in addition to Braun's lipoprotein and a peptidoglycan-associated lipoprotein called PAL, were found in the envelope of Escherichia coli. The new lipoproteins were immunochemically different from both Braun's lipoprotein and PAL. A strain lacking the structural gene for Braun's lipoprotein contained new lipoproteins and PAL. In addition to Braun's lipoprotein and PAL, four new lipoproteins were found to be localized in the outer membrane, while other two species were found in the cytoplasmic membrane. The localization of one species is unknown. We previously reported that, on treatment of cells with globomycin, a precursor of Braun's lipoprotein accumulated in the cell envelope (Hussain, M., Ichihara, S., and Mizushima, S. (1980) J. Biol. Chem. 255, 3707-3712). Similarly, the putative precursors of new lipoproteins and that of PAL accumulated in globomycin-treated cells. These precursors contained glycerol and fatty acid(s) as that of Braun's lipoprotein did. It is suggested that the structures of the "signal" region and the mechanisms of processing of all the lipoproteins of E. coli are similar.