Myoglobin-like aerotaxis transducers in Archaea and Bacteria

Haem-containing proteins such as haemoglobin and myoglobin play an essential role in oxygen transport and storage. Comparison of the amino-acid sequences of globins from Bacteria and Eukarya suggests that they share an early common ancestor, even though the proteins perform different functions in these two kingdoms. Until now, no members of the globin family have been found in the third kingdom, Archaea. Recent studies of biological signalling in the Bacteria and Eukarya have revealed a new class of haem-containing proteins that serve as sensors. Until now, no haem-based sensor has been described in the Archaea. Here we report the first myoglobin-like, haem-containing protein in the Archaea, and the first haem-based aerotactic transducer in the Bacteria (termed HemAT-Hs for the archaeon Halobacterium salinarum, and HemAT-Bs for Bacillus subtilis). These proteins exhibit spectral properties similar to those of myoglobin and trigger aerotactic responses.

Successful percutaneous stenting of a right gastroepiploic coronary bypass graft using monorail delivery system: a case report

The right gastroepiploic artery (RGEA) is being successfully used as an arterial conduit in a selected group of patients undergoing coronary artery bypass graft surgery. However, myocardial ischemia may result due to spasm, occlusion, and stenosis of this graft. The anastamosis site at distal right coronary artery (RCA) or posterior descending artery (PDA) is the most common location for stenosis of an in situ gastroepiploic coronary bypass graft. Balloon angioplasty of such stenoses has been reported with optimal short-term results. Stent deployment would decrease the restenosis rate, so that repeat procedures could be minimized for these technically challenging lesions. We describe a case of successful deployment of a stent with monorail delivery system at the anastamotic site stenosis of an in situ gastroepiploic right coronary artery bypass graft. This percutaneous coronary intervention could prevent redo coronary artery bypass graft surgery. Cathet. Cardiovasc. Intervent. 49:197-199, 2000.

Clinical predictors of heart failure in patients with first acute myocardial infarction

BACKGROUND

The occurrence of heart failure associated with an acute myocardial infarction has a strong adverse effect on long-term morbidity and mortality. The prediction and prevention of heart failure could influence these adverse events.

METHODS AND RESULTS

We studied 483 consecutive patients who had their first acute myocardial infarction and who were admitted within 24 hours of the onset of symptoms. Heart failure was defined as the presence of pulmonary rales or an S3 gallop, or the presence of alveolar or interstitial edema by radiograph. Baseline demographic data, determination of peak creatine phosphokinase level, echocardiographic left ventricular ejection fraction, blood pressure, and pulse were obtained. Heart failure occurred in 41.6% (201 of 483) of the patients. We observed a bimodal occurrence of heart failure with an early occurrence at admission in 4% (20 of 483) followed by a second increase beginning after the fourth day of admission in 39% of the remaining patients (181 of 463). Predictors of early heart failure were older age, diabetes mellitus, or previous cardiac symptoms, whereas the predictors of heart failure after the fourth day included the same demographic predictors in addition to a history of hypertension, male sex, increased peak creatine phosphokinase level and heart rate, and decrease in left ventricular ejection fraction. In-hospital death occurred in 5.3% compared with 1.4% (P =.012) in patients who did and did not have heart failure, respectively. The occurrence of heart failure during hospital admission also adversely affected the 18-month follow-up, with 14.9% deaths in the patients with heart failure and 6.4% in those without heart failure (P =.002).

CONCLUSION

Heart failure is frequently associated with acute myocardial infarction and occurs with a bimodal distribution and is associated with increased risk of death during hospitalization and during 18 months of follow-up. Predictors of early heart failure include previous medical conditions and age. The second peak occurrence can be predicted by similar characteristics in addition to increased peak creatine phosphokinase level, decreased left ventricular ejection fraction, and increased heart rate.

Cardioversion of atrial fibrillation and its effect on right ventricular function as assessed by tricuspid annular motion

In patients with atrial fibrillation, the reduced right ventricular function determined by tricuspid annular motion before cardioversion returns to normal 1 month after successful cardioversion to sinus rhythm. The simplicity of recording the tricuspid annular motion provides an easy opportunity to assess right ventricular function following electroconversion of atrial fibrillation to sinus rhythm.

Eruptive paraneoplastic keloids

We present a 66-year-old woman who developed eruptive keloids in association with endometrial carcinoma in the absence of trauma, surgery, inflammation, or other known preludes to keloid formation. Keloid formation and endometrial carcinoma are both associated with similar cytokine abnormalities and as such, we hypothesize that this is a previously unreported paraneoplastic phenomenon.

Indinavir-related recurrent paronychia and ingrown toenails

Lamivudine and indinavir are two medications used to treat human immunodeficiency virus (HIV) that have recently been reported to cause paronychia. The nails of the great toes are commonly affected. This is the second report of paronychia and ingrown toenails due to indinavir and the first report of recurrent paronychia and ingrown toenails associated with this drug.

Characteristics of mitral and tricuspid annular velocities determined by pulsed wave Doppler tissue imaging in healthy subjects

Assessment of myocardial velocities by Doppler tissue imaging is gaining in importance. However, generally accepted reference values are still missing. In this study we examined 62 consecutive healthy subjects (mean age 46, range 22-82 years) by pulsed wave Doppler tissue imaging to characterize the systolic and diastolic velocity profiles of the left and right ventricles. The subjects were divided into 3 different age-groups: group I, younger than 40 years; group II, 40 to 59 years; and group III, 60 years and older. Recordings were made along the long axis in the apical 4- and 2-chamber views by using 4 sites (septal, anterior, lateral, and inferior) at the mitral annulus and 1 site at the tricuspid annulus. Systolic mitral annular velocity (10.3 +/- 1.4 cm/s) correlated strongly with global left ventricular function determined by M-mode echocardiographic mitral annular displacement (r = 0.70, P <.001). The systolic velocity was significantly lower in group III than in group I (9.6 vs 10.8 cm/s, P <.01). A relatively weak, but significant, correlation was found between systolic velocity and the age of the subjects (r = -0.43, P <.001). Mitral annular early diastolic velocity was also lower in group III compared with group I (11.3 vs 17.7 cm/s, P <.001), with a strong correlation with age (r = -0.81, P <.001) and other conventional Doppler diastolic parameters. Both the systolic and early diastolic mitral annular velocities at the septum were lower than at other left ventricular sites. Tricuspid annular systolic velocity (15.2 +/- 1.9 cm/s) was higher than mitral annular systolic velocity (P <.001). Unlike mitral annular velocity, systolic tricuspid annular velocity was not correlated with age. However, the diastolic tricuspid annular velocities correlated well with transtricuspid Doppler diastolic parameters. The method of recording the annular velocities was feasible in all subjects, simple and highly reproducible.

Coronary artery aneurysms, aortic dissection, and hypertension secondary to primary aldosteronism: a rare triad. A case report

Primary aldosteronism is a relatively uncommon etiology of hypertension. Plasma renin activity is suppressed in the majority of the cases but not always. Plasma renin activity has been associated with increased vascular injury. The occurrence of vascular complications has rarely been reported with low plasma renin activity. The authors report a case of long-standing secondary hypertension due to primary aldosteronism with coronary artery aneurysms and aortic dissection. Diagnosing is important, for therapeutic intervention can be curative.

Spectroscopic characterization of two soluble transducers from the Archaeon Halobacterium salinarum

In the present study, structural aspects of the two soluble transducers, HtrX and HtrXI, from the archaeon H. salinarum have been examined using UV circular dichroism and steady-state fluorescence spectroscopies. Circular dichroism (CD) data indicate that both HtrX and HtrXI exhibit salt-dependent protein folding. Under low-ionic-strength conditions (0.2 M NaCl or KCl) the CD spectra of HtrXI is similar to that of the Gdn-HCl- or urea-denatured forms and is indicative of random coil structure. In contrast, the CD spectrum of HtrX under low-ionic-strength conditions contains roughly 85% alpha-helical character, indicating a significant degree of folding. Addition of NaCl or KCl to solutions of HtrX or HtrXI results in CD features consistent with predominately alpha-helical character (>95%) for both proteins. In addition, the transition points (i.e., ionic strengths at which the protein converts from random coil to alpha-helical character) are quite distinct and dependent upon the type of salt present (i.e., either NaCl or KCl). Accessibility of tryptophan residues to the solvent was also examined for both HtrX and HtrXI in both folded and unfolded states using KI quenching. The Stem-Volmer constants obtained suggest that the tryptophans (Trp35 in HtrX and both Trp47 and Trp74 in HtrXI) are partially exposed to the solvent, indicating that they are located near the surface of the protein in all three cases. Furthermore, fluorescence quenching with the single Trp mutants Trp74AIa and Trp47AIa of HtrXI indicates different environments for these two residues.

ST-T alternans and myocardial ischemia

Previous studies using intracoronary electrocardiography have demonstrated that ST-T alternans can develop during standard balloon coronary angioplasty. Total occlusion with a large amount of myocardium in jeopardy is the postulated prerequisite. In this study, the authors used perfusion balloons instead of standard balloons, so coronary perfusion was maintained and ischemia was minimized. Fourteen patients with standard balloon technique and 11 patients with perfusion balloon technique were studied. The ST segment was less elevated during perfusion angioplasty (0.15 +/- 0.05 mV vs 1.04 +/- 0.19 mV, p<0.001). There were six (43%) patients with ST-T alternans with standard balloon technique compared with none in the perfusion balloon group (p<0.001). In this study, the authors found that there was less ischemia, less ST segment elevation, and lack of ST-T alternans on the intracoronary electrocardiogram during perfusion balloon angioplasty. These findings support the postulate that a large amount of ischemic myocardium is a prerequisite for ST-T alternans.

A study of the cost effectiveness of selective health interventions for the control of intestinal parasites in rural Bangladesh

The study examined the cost effectiveness of 4 different regimens in reducing the prevalence and intensity of infection of Ascaris lumbricoides, Trichuris trichiura, and hookworm over an 18-mo period in randomized community samples of children aged 2-8 yr living in rural Bangladesh. The household was the unit of randomization in each community. The 4 regimens were (1) only chemotherapy to all household members at the commencement of the study (i.e., at an interval of 18 mo), (2) same as group (1) and regular health education throughout the study period, (3) chemotherapy to all household members at the commencement of the study and subsequent chemotherapy to all children at intervals of 6 mo, and (4) same as group 3 with the addition of regular health education throughout the study period. Health education (through home and school visits and focus group discussions) was aimed at increasing awareness of worm transmission and the disabilities caused by intestinal helminths. Simple ways of improving personal hygiene and sanitation through hand washing, nail trimming, wearing of shoes, and use of a latrine and clean water supplies were encouraged. Because albendazole is a broad spectrum anthelmintic, the cost effectiveness of the 4 interventions were compared by the weighted percentage reduction in prevalence and the weighted percentage reduction in intensities of infection as measured by geometric mean egg loads of all 3 worms combined. The most cost-effective strategy was the single albendazole mass chemotherapy at an interval of 18 mo. The 2 regimens involving health education were the least cost effective.

Detection of exercise-induced reversible right ventricular wall motion abnormalities using echocardiographic determined tricuspid annular motion

Effects of exercise on tricuspid annular motion at the right ventricular free wall was studied by echocardiography. The results suggest that exercise-related reversible changes in tricuspid annular motion may be used to identify patients with proximal right coronary artery stenosis.

Conformationally defined retinoic acid analogues. 4. Potential new agents for acute promyelocytic and juvenile myelomonocytic leukemias

We recently synthesized several conformationally constrained retinoic acid (RA) analogues [8-(2'-cyclohexen-1'-ylidene)-3, 7-dimethyl-2,4,6-octatrienoic acids with different alkyl substituents at 2' (R1) and 3' (R2) positions on the cyclohexene ring] (Muccio et al. J. Med. Chem. 1996, 39, 3625) as cancer chemopreventive agents. UAB8 (R1 = Et; R2 = iPr), which contains sufficient steric bulk at the terminal end of the polyene chain to mimic the trimethylcyclohexenyl ring of RA, displayed biological properties similar to those of RA. To explore the efficacy of this retinoid in acute promyelocytic leukemia (APL) and juvenile myelomonocytic leukemia (JMML), we evaluated UAB8 isomers in in vitro assays which measure the capacity of retinoids to inhibit aberrant myeloid colony growth from blood or bone marrow cells obtained from human JMML patients and in assays measuring the potential of retinoids to differentiate NB4 cells (an APL cell line). Both (all-E)- and (13Z)-UAB8 were 2-fold more active than RA in the NB4 cell differentiation assay; however, only (all-E)-UAB8 had comparable activity to the natural retinoids in the JMML cell assays. These results were compared to the biological effectiveness of a new retinoid, UAB30 [8-(3', 4'-dihydro-1'(2'H)-naphthalen-1'-ylidene)-3,7-dimethyl-2,4, 6-octatrienoic acid], which had different nuclear receptor binding and transactivational properties than UAB8. Relative to (all-E)-RA and (all-E)-UAB8, (all-E)-UAB30 bound well to RARalpha but did not activate transcription-mediated RARalpha homodimers, even though it was effective in RARbeta- and RARgamma-mediated transactivational assays. In APL assays, this retinoid had much reduced activity and was only moderately effective in JMML assays and in cancer chemoprevention assays.

An archaeal aerotaxis transducer combines subunit I core structures of eukaryotic cytochrome c oxidase and eubacterial methyl-accepting chemotaxis proteins

Signal transduction in the archaeon Halobacterium salinarum is mediated by three distinct subfamilies of transducer proteins. Here we report the complete htrVIII gene sequence and present analysis of the encoded primary structure and its functional features. HtrVIII is a 642-amino-acid protein and belongs to halobacterial transducer subfamily B. At the N terminus, the protein contains six transmembrane segments that exhibit homology to the heme-binding sites of the eukaryotic cytochrome c oxidase. The C-terminal domain has high homology with the eubacterial methyl-accepting chemotaxis protein. The HtrVIII protein mediates aerotaxis: a strain with a deletion of the htrVIII gene loses aerotaxis, while an overproducing strain exhibits stronger aerotaxis. We also demonstrate that HtrVIII is a methyl-accepting protein and demethylates during the aerotaxis response.

Joint wavelet transform correlation with separated target and reference planes

In recent years, we realize the usefulness of feature extraction for optical correlator and hereby, we investigate the capability of Laplace operator in feature extraction of multiple targets. The first-order terms and the false alarm terms in the correlation output would be removed using electronic power spectrum subtraction technique. Most importantly, the entire magneto-optic SLM is completely utilized for displaying only targets in the input scene. A new cost efficient hardware implementation is proposed and aforementioned result of the proposed system is evaluated through computer simulation.

Sensory rhodopsin II transducer HtrII is also responsible for serine chemotaxis in the archaeon Halobacterium salinarum

Previously, we demonstrated that the methyl-accepting protein HtrII is the transducer for photoreceptor sensory rhodopsin II. Here, we provide experimental evidence that HtrII is also a chemotransducer. Using an agarose-in-plug bridge method, we show that an HtrII overexpression strain has a quicker response to serine than does an HtrII deletion strain. Furthermore, an in vivo flow assay demonstrates that the deletion strain is unable to modulate methylesterase activity after serine addition or photostimulation, while the overexpression strain shows distinct methanol peaks following both types of stimuli.

Structure and absolute stereochemistry of salvimirzacolide, a new sesterterpene from Salvia mirzayanii

A new sesterterpene, salvimirzacolide (1), was isolated from the aerial parts of Salvia mirzayanii and its structure established by X-ray diffraction analysis. Full assignments of 1H- and 13C-NMR spectral data of salvimirzacolide are presented.

Aspergillus fungal mass detected by transesophageal echocardiography

Cardiac fungal infections have become more prevalent and are being diagnosed with increasing frequency. The most common infective organism is Candida albicans, followed by Aspergillus fumigatus and Cryptococcus. Cardiac involvement is usually associated with endocarditis, myocarditis, pericarditis, or intracardiac fungal mass. Early diagnosis is imperative, as these patients have poor outcome once there is cardiac involvement. In this report we describe a patient in whom an intracardiac mass was detected with transesophageal echocardiography and confirmed to be aspergillus fungal ball at surgery.