bluuebunny/crossref_metadata_2025_split huggingface dataset:
Role of Stress Response Sigma Factor SigG in
Mycobacterium tuberculosis
Authors: Lee Jong-Hee , Geiman Deborah E. , Bishai William R. 
Published: November 2007

ABSTRACT

The
sigG
gene of
Mycobacterium tuberculosis
was disrupted by homologous recombination, and the genes regulated by SigG were examined by real-time reverse-transcription PCR and microarray studies. The SigG consensus promoter recognition sequence was identified as GCGNGT-N
15-18
-CGANCA. A Δ
sigG
mutant was found to be more resistant to mitomycin C treatment than the wild-type strain, indicating that it may be involved in the SOS response in
M. tuberculosis
.
Natural Variability in
S
-Adenosylmethionine (SAM)-Dependent Riboswitches: S-Box Elements in
Bacillus subtilis
Exhibit Differential Sensitivity to SAM In Vivo and In Vitro
Authors: Tomšič Jerneja , McDaniel Brooke A. , Grundy Frank J. , Henkin Tina M. 
Published: November 2007

ABSTRACT

Riboswitches are regulatory systems in which changes in structural elements in the 5′ region of the nascent RNA transcript (the “leader region”) control expression of the downstream coding sequence in response to a regulatory signal in the absence of a
trans
-acting protein factor. The S-box riboswitch, found primarily in low-G+C gram-positive bacteria, is the paradigm for riboswitches that sense
S
-adenosylmethionine (SAM). Genes in the S-box family are involved in methionine metabolism, and their expression is induced in response to starvation for methionine. S-box genes exhibit conserved primary sequence and secondary structural elements in their leader regions. We previously demonstrated that SAM binds directly to S-box leader RNA, causing a structural rearrangement that results in premature termination of transcription at S-box leader region terminators. S-box genes have a variety of physiological roles, and natural variability in S-box structure and regulatory response could provide additional insight into the role of conserved S-box leader elements in SAM-directed transcription termination. In the current study, in vivo and in vitro assays were employed to analyze the differential regulation of S-box genes in response to SAM. A wide range of responses to SAM were observed for the 11 S-box-regulated transcriptional units in
Bacillus subtilis
, demonstrating that S-box riboswitches can be calibrated to different physiological requirements.
Structural Basis for Different Substrate Specificities of Two ADP-Ribose Pyrophosphatases from
Thermus thermophilus
HB8
Authors: Wakamatsu Taisuke , Nakagawa Noriko , Kuramitsu Seiki , Masui Ryoji 
Published: November 2007

ABSTRACT

ADP-ribose (ADPR) is one of the main substrates of Nudix proteins. Among the eight Nudix proteins of
Thermus thermophilus
HB8, we previously determined the crystal structure of Ndx4, an ADPR pyrophosphatase (ADPRase). In this study we show that Ndx2 of
T. thermophilus
also preferentially hydrolyzes ADPR and flavin adenine dinucleotide and have determined its crystal structure. We have determined the structures of Ndx2 alone and in complex with Mg
2+
, with Mg
2+
and AMP, and with Mg
2+
and a nonhydrolyzable ADPR analogue. Although Ndx2 recognizes the AMP moiety in a manner similar to those for other ADPRases, it recognizes the terminal ribose in a distinct manner. The residues responsible for the recognition of the substrate in Ndx2 are not conserved among ADPRases. This may reflect the diversity in substrate specificity among ADPRases. Based on these results, we propose the classification of ADPRases into two types: ADPRase-I enzymes, which exhibit high specificity for ADPR; and ADPRase-II enzymes, which exhibit low specificity for ADPR. In the active site of the ternary complexes, three Mg
2+
ions are coordinated to the side chains of conserved glutamate residues and water molecules. Substitution of Glu90 and Glu94 with glutamine suggests that these residues are essential for catalysis. These results suggest that ADPRase-I and ADPRase-II enzymes have nearly identical catalytic mechanisms but different mechanisms of substrate recognition.
TOWARDS AN INSTITUTIONS-THEORETIC FRAMEWORK COMPARING SOLAR PHOTOVOLTAIC DIFFUSION PATTERNS IN JAPAN AND THE UNITED STATES
Authors: SHUM KWOK L. , WATANABE CHIHIRO 
Published: November 2007

This paper studies and compares the actual historic solar photovoltaic (PV) installation data in Japan and the United States and proposes two deployment models to account for the differences. Deployment, along with research, development and demonstration, constitutes what is known as the RD3 (PCAST — President's Council of Advances in Science and Technology, United States) innovative chain of a new technology. Japan deploys PV focusing on the niche of utility grid-tied small-scale system (90 per cent of which is standardised roof-top residential PV system) using highly integrated value chain; this seems to draw upon her strong manufacturing culture and associated social technology and institutions for suppliers-dominated innovations. The United States deploys PV as a broadly defined innovation emphasising user-oriented customisation in both on and off grid, residential and industrial applications using small independent and intermediary system integrators. Empirical analysis of the diffusion patterns in the grid-tied small system category in respective contexts suggests that Japan's institutions seem to match her mass deployment strategy while the United States' combination of fragmented industry structure and diversity deployment gives rise to a complex diffusion pattern calling for continual institutional innovation or co-evolution. Our research, therefore, highlights that commercialisation of new technology or technical change, in general, is not an autonomous process and has strong institutional underpinnings. We formalise and generalise this "match" (Perez, 1983) argument in accordance with Nelson and Sampat's (2001) framework of physical technology vs social technology and their interactions. Some potential future extensions regarding utilities for this model are then highlighted.
Spontaneous Changes in Hemodynamics in Uncomplicated Acute Myocardial Infarction: a Prospective Echocardiographic Study
Authors: Aronow Wilbert S. , Prakash Ravi 
Published: November 2007

Spontaneous changes in heart rate (HR), systolic and diastolic blood pressure, left ventricular end-diastolic dimension (LVEDD), and left ven tricular end-systolic dimension (LVESD) over a 95-minute period were evaluated in 13 patients with uncomplicated myocardial infarction within 48 hours of infarction. The patients were on no medication at the time of their study. ECGs, blood pressures, and echocardiograms were recorded every 1 minute for 5 minutes (control period) and 1, 3, 5, 10, 20, 30, 45, 60, and 90 minutes (study period) after the control measurements. The mean control LVEDD was 57.4 ± 10.0 mm; the standard deviation (SD) across the control values was 0.9 mm. The mean LVEDD during the 90-minute study period was 57.5 ± 9.7 mm; the SD across the 90-minute study period values was 1.4 mm. The mean control LVESD was 48.3 ± 11.4 mm; the SD across the control value was 1.0 mm. The mean LVESD during the 90-minute study period was 48.9 ± 11.0 mm; the SD across the 90-minute study period was 1.7 mm. No significant differences in HR, systolic or diastolic blood pressure, LVEDD, and LVESD occurred be tween the 5 control values and the 10 values obtained during the 90- minute study period in the 13 patients in this study. We conclude that (1) reproducible measurements of LVEDD and LVESD can be obtained by echocardiography in stable patients with uncomplicated acute myocardial infarction over a 95-minute period; and (2) the hemodynamic variables are stable in uncomplicated myocardial infarction over a 95-minute period.
Peripheral Venous Platelet Aggregates in Patients With Unstable Angina Pectoris and Acute Myocardial Infarction
Authors: Willerson James T. , Willerson James T. 
Published: November 2007

In vivo peripheral venous platelet aggregates (PVPA) have been demon strated in patients with myocardial infarction (MI), transient cerebral ischemic attacks (TIAs), and acute arterial insufficiency by the platelet count ratio (PCR) method. But PVPA determinations have not been reported in patients with unstable angina pectoris (UA), controls have not been specified as acutely ill in earlier studies using this technique, and variability of the method has not been presented in detail. Because platelet aggregation has been mentioned as a possible mechanism for perpetuating myocardial ischemia, we studied 21 acutely ill noncardiac control (NC) patients, 17 UA patients, and 13 MI patients for PVPA. PCR represents ratio of platelet counts obtained when identical aliquots of blood were drawn into two syringes containing formalin-EDTA and EDTA respectively. Free flow was demonstrated before blood was drawn. Mean PCR was 0.90 ± 0.01 (SE) in NC, 0.85 ± 0.02 in UA, and 0.85 ± 0.02 in MI. In the subset of 7 patients with acute transmural MI, PCR was 0.83 ± 0.02. Only this subset was significantly different from NC (P < 0.001). PCR did not vary significantly with age or sex. Aspirin history was positive in 25-30% of the patients in each group and raised PCR by an average of 0.04 units. When PCR was repeated after 45 minutes in 6 patients, moderate variability with a mean absolute change in PCR of 0.08 was noted. Our data fail to support an etiologic role for circulating platelet aggre gates in initiating UA. Clinical trials of platelet inhibitors and experimen tal models of arterial insufficiency probably offer the greatest chance of further defining the potential etiologic role of platelet aggregation in initiating or perpetuating myocardial ischemic phenomena.
Acral Diagnosis and Possibilities of Conservative Treatment of Chronic Obstructive Vascular Diseases
Authors: Köenig F.K. 
Published: November 2007

One of the main problems which confronts a doctor practicing in the angiology field is the decision if a conservative treatment alone is going to be sufficient for a patient or if he has to decide for vascular surgery. Concerning the latter, there should be kept in mind that always an additional conservative therapy is of utmost importance since chronic vascular disease is looked at as a generalized phenomenon and surgical therapy can be used only in limited segments. In order to make a decision whether conservative or surgical therapy should be applied we used the "Nitrate Test"—described in 1968 by Migliorini, Italy and in 1976 by Böhme, Germany—modified and developed it further. Migliorini and Böhme stated that an increased blood flow after nitrate application is useful for the determination whether a patient suffers from a functional or an organic vascular disease.
Lack of Effect of Cyclandelate in Peripheral Arterial Disease
Authors: Vyden John K. , Nagasawa Koichi , Kanazawa Masakuni , Rose Harold B. , Seino Yoshihiko , Groseth-Robertson Marsha F. , Lander Elliot B. , Elconin Steven B. 
Published: November 2007

While cyclandelate is widely used in the therapy of peripheral arterial disease, objective evidence of its efficacy remains controversial. For this reason, 12 patients with intermittent claudication (average age of 66.8 years) received both cyclandelate 400 mg qid and placebo in a double-blind crossover trial lasting two months. During the cyclandelate and placebo periods, the following peripheral hemodynamic measurements were obtained using a plethysmograph and treadmill claudication testing: mean calf blood flow, vascular resistance and venous capacitance; finger and toe blood flow, pulsation amplitude and tem perature before and after vasodilating maneuvers; arm and leg arterial pulsa tion amplitudes, one and ten minute calf reactive hyperemia reaction; 30 pound/30 second calf active hyperemia reactions and times of onset of claudi cation as measured on a treadmill. No major significant difference could be demonstrated between placebo and cyclandelate on any subjective symptom or any objective measurement. It is concluded that cyclandelate 400 mg qid for 4 weeks was of little objective value in treating this group of 12 patients with peripheral arterial disease and suffering from intermittent claudication.
Iliac Artery Aneurysm in Behçet's Disease: A Case Report
Authors: Dündar-Kaldirimci Semra V. , Ates K. Bahri , Akpolat Tekin , Nazli Nasih 
Published: November 2007

Today, Behçet's disease is known as a multisystem disorder.1-4 Eye lesions, mouth and genital aphthous lesions, and skin lesions are accepted as major lesions. The disease also attacks the locomotor system, central nervous system, gastrointestinal system and also arteries and veins. According to available data, some 30% of the patients have vascular lesions; mostly thrombosis of the veins. Arterial thromboses have been rarely reported; and only a few number of arte rial aneurysms are noted.5-13 Here we present an iliac artery aneurysm in a case of Behçet's disease.
Atherosclerosis
Authors: DeCarvalho Sergio 
Published: November 2007

For a historical survey of the pathogenesis of atherosclerosis the reader is referred to references 1 and 2. Comprehension of the vessel-blood interface homeostasis hinges upon an un derstanding of the pathophysiology of angio-lymphoid relationships. Even in the smooth contact of the intact hydrophobic intimal lining with the marginal flow of the circulatory stream, small amounts of thrombin and small aggregates of aging platelets float by under physiologic conditions. Since endo thelial cells of the vascular intima contain receptors for thrombin, filling these receptors with thrombin becomes a stimulus for the production of prostacyclin (PGI2) by the endothelial cells; PGI2 in turn inhibits adherence of the small platelet aggregates by ADP; homeostasis is maintained. The size of physiologic thrombin-producing platelet microaggregates is controlled by physiologic levels of antithrombin III.
Graphic Representation of Carotid Artery Bruits
Authors: Leonberg Stanley C. 
Published: November 2007

Auscultation of the neck for detection of bruits over the carotid arteries has become a necessary part of any complete physical examination. Early detection of atherosclerotic occlusive disease in these vessels can play a major role in prevention of stroke. Such findings have previously been recorded as word descriptions in varying degrees of detail. A method is presented for quickly and easily recording the presence and character of cervical bruits, plus additional important information, including blood pressure, pulse, heart rhythm, prior vascular surgery, and known occlusion in these vessels. The figure used allows others to rapidly perceive this information and enables ready comparison on successive examinations.
Three-Dimensional Vectorcardiography (3-D VCG) by Computer Graphics in Old Myocardial Infarction
Authors: Morikawa Junichiro , Kitamura Kazuto , Habuchi Yoshizumi , Tanaka Nobuyuki , Nishimoto Youichi , Hirano Masaaki , Tsujimura Yoshinori , Hamamoto Hajime , Takanashi Tadahiro 
Published: November 2007

By using computer graphics we rotated the vector loop and three coordinate axes to find the viewpoint where the infarctional changes are maximally exposed and demonstrated the advantage of the "3-D VCG" over the conventional VCG by defining the quantitative "MI index." The orthogonal electrocardiogram recorded by the Frank lead system was digitally measured and processed by a microcomputer. The loops and axes were rotated about the X axis (X-rot) and the Y axis (Y-rot). The spatial vector loop and orthogonal coordinates can be presented as viewed from any spheric direc tion. Eight quadrants were illustrated with four colors and red circles. The subjects consisted of 30 patients with old anterior myocardial infarction (MI) and 15 patients with old inferior MI. We measured the area of "Bite" in anterior MI and superior displacement in inferior MI. The MI index was de fined and averaged in 361 directions. In anterior MI, the maximum mean index was obtained when X-rot is +90° and Y-rot -40°, viewed from upward and leftward, whereas in inferior MI it was obtained when X-rot is -50° and Y-rot -80°, viewed from downward and leftward. These values were significantly higher than those in conventional VCG pro jections, substantiating superior diagnostic sensitivity of 3-D VCG.
Late Chronic Hemolysis after Valve Replacement for Aortic Stenosis. Relation to Residual Hypertrophy and Impaired Left Ventricular Function
Authors: Lund Ole 
Published: November 2007

The relationship between intravascular hemolysis induced by aortic valve pro steses and patient status/left ventricular (LV) function (radionuclide cardiography) was examined in 63 patients of 65 who were alive ten to seventeen years after valve replacement (1965-1973) for aortic stenosis. Serum-lactic dehydrogenase (LDH) exceeded upper reference limit in 62 patients and S-haptoglobin (HAPTO) was reduced in 62. One patient with normal LDH had reduced HAPTO and elevated plasma-hemoglobin. Anemia was noted in 4 patients (6%). S-LDH was higher in men than in women (p<0.05), in patients with increased ECG hypertrophy score than in those with a normal score (p<0.05), in patients with NYHA class II-III than in those with class I (p<0.05), in patients with abnormal LV function than in those with a normal radionuclide study (p<0.05), in patients with a pathologic Q wave in the ECG than in those without (p<0.05), and in patients with a Starr Edwards cloth-covered (SECC) prosthesis than in those with other types (p = 0.07). ECG hypertrophy score correlated directly with LDH (r=0.33, p = 0.008) and inversely with LV ejection fraction (r = -0.57, p<0.0001), peak ejection rate (r = -0.47, p<0.0001), and peak filling rate (r = -0.41, p<0.001). Multiple linear regression analysis revealed that LDH was accounted for by ECG hypertrophy score (p = 0.001), SECC prosthesis (p = 0.04), and male gender (p = 0.05). Hypertrophic malfunctioning left ventricles may be responsible for higher degrees of turbulent flow characteristics in the vicinity of prosthetic valves in the aortic position and, by inference, explain the increased tendency toward hemol ysis in these patients.
The Acute and Chronic Effects of G-Lasing on Femoral Vein Grafts in Dogs
Authors: Burger Andrew J. , Peart Brenda , Freeman David , Alfonso Gilbert , Wheeler William , Touchon Robert 
Published: November 2007

Each year, 5 % of all coronary artery bypass operations are repeat procedures, and 15 % -30 % of coronary artery vein grafts occlude within the first eighteen months postoperatively. To evaluate the macroscopic and histologic effects of G-lasing on vein grafts and their patency, femoral veins were used to bypass bilaterally induced stenoses of femoral arteries in 10 dogs. The left vein grafts were G-lased with a 1.5 mm, hot-tipped argon laser at 5 watts for ninety seconds, while the right grafts were used as the controls. Acutely, each vein graft demonstrated no evidence of charring or perforation. The percentage of endothelium present in the G-lased vein grafts was consistently less than 5 %, whereas the control vein grafts had an average of 70%. After ten weeks, the animals were sacrificed, and the vein grafts were evaluated for histologic changes and patency. There were no significant microscopic differences between the G-lased and control vein grafts. A statistically significant difference in graft patency was not achieved between G-Lased and control vein grafts at 10 weeks, but only a small number of grafts were studied. Further studies will be needed to evaluate the effects of G-lasing on the long-term patency of vein grafts.
Sustained Supraventricular Tachyarrhythmias Following Coronary Artery Bypass Surgery Comparing Mammary Versus Saphenous vein Grafts
Authors: Salem Bakr I. , Chaudhry Abdul , Haikal Maged , Gowda Siddhesh , Campbell Amy , Coordes Cordie , Leidenfrost Ronad 
Published: November 2007

This retrospective study was designed to determine the incidence of sus tained supraventricular tachyarrhythmias (SVTs) in patients undergoing coro nary artery bypass grafting (CABG) with internal mammary artery (IMA) grafts, Group A, compared with those with saphenous vein grafts (SVG), Group B. Among 569 consecutive patients who underwent CABG surgery in the same institution, a total of 80 cases from Group A and 80 cases from Group B were selected for this study after application of exclusion criteria. Excluded from this study were the following: patients wth preexisting or prior history of SVTs, significant left ventricular dysfunction (ejection fraction less than 40%), postop erative myocardial infarction, drug toxicity or electrolyte imbalance, and ad vanced chronic obstructive lung disease. Group A consisted of 63 men and 17 women and Group B consisted of 52 men and 28 women. All patients were monitored either in ICU or by telemetry for a period of three to six days after surgery and all had a predischarge 12-lead electrocardiogram. Both groups were fairly comparable in most of their clinical profile and number of grafts. The incidence of SVTs in Group A was 31 % (25 of 80 patients) and in Group B was 24% (19 of 80 patients). Furthermore, the incidence of postoperative pericarditis was noted in 35% (28 of 80 patients) of Group A and in 19% (15 of 80 patients) in Group B. The authors conclude that male tobacco smokers of Group A tended to have a significantly higher incidence of postoperative pericarditis with a higher trend for postoperative SVTs than patients from Group B.
Systolic Ejection Murmurs in the Elderly: Aortic Valve and Carotid Arteries Echo-Doppler Findings
Authors: Vigna Carlo , Impagliatelli Matteo , Russo Aldo , Pacilli Michele , De Rito Vincenzo , Perna Gian Piero , Villella Alessandro , Langialonga Tommaso , Fanelli Raffaele , Rinelli Gabriele , Lombardo Antonella , Loperfido Francesco 
Published: November 2007

Two-dimensional echographic and color Doppler studies of the heart and carotid arteries (CA) were performed in 45 patients > sixty-five years old without aortic stenosis, 23 with (Group 1) and 22 without (group 2) precordial ejection systolic murmur (SM). Aortic cusps thickening was found in 11 Group 1 (48%) and 2 Group 2 (9%) patients (p < 0.001). Aortic root and aortic arch size were similar in the two groups. Maximum aortic flow velocity was significantly greater in Group 1 (200 60 cm/sec) than in Group 2 (120 20 cm/sec) (p < 0.001). Left ventricular outflow systolic maximum velocity was similar in the two groups. A bilateral neck murmur was heard in 10/23 Group 1 patients (43%); in this group, patients with cervical SM had a greater maximum aortic flow velocity than those without cervical SM (230 + 60 cm/sec vs 172 + 32 cm/sec, p < 0.001). In Group 1, 3 patients had a cervical SM louder on one neck side; only in these 3 patients were ipsilateral obstructive CA plaques found. A unilateral neck SM was heard in 4/22 Group 2 patients (18%); in these 4, ipsilateral obstructive CA were found. Conclusions: (1) in the elderly, precordial ejection SM is related to mild increase in maximum aortic flow velocity and thickening of aortic cusps; (2) in patients with precordial SM radiated to both neck sides, maximum aortic flow velocity tends to be more markedly increased; (3) in patients with precordial SM, a cervical SM louder on one neck side should suggest coexistent ipsilateral CA stenosis.