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Objective: To describe changes in delay to administration of thrombolytic therapy associated with a region-wide audit. Design: Observational study of patients admitted with suspected myocardial infarction (MI) based on continuous audit. Subjects: 18 877 patients admitted to 23 hospitals with suspected MI between April 1995 and March 1998. Results: Of 11 232 patients with a discharge diagnosis of definite MI, 8802 (46.6%) received thrombolytic therapy during hospitalisation, with 5155 patients eligible for treatment on admission to hospital on the basis of established indications. Call-to-needle time for those eligible for treatment on admission fell from median 105 min in the first year of the project to 85 min in year 3 (P<0.001), and door-to-needle time fell from 45 to 35 min (P<0.001). Forty percent of eligible patients were treated within the then current national standard of 90 min from time of call for help, with nearly 49% in the final year and 20% being treated within the new national standard of 60 min, by the third year. Conclusion: The proportion of eligible patients receiving thrombolysis within 1 h of the call for help doubled during the 3-year project but the majority of patients still wait longer than 60-min `call-to-needle'. New systems to reduce delays to administration of thrombolysis to within 60 min of call for help are required, including consideration of pre-hospital treatment. [ABSTRACT FROM AUTHOR]

1 A double-blind cross over study was carried out to assess the effects of the combination of nifedipine and propranolol in 25 patients with chronic stable angina pectoris at beta-adrenoceptor blockade. 2 Efficacy was judged objectively by a standardized exercise protocol using a bicycle ergometer and subjectively by patient assessment of anginal attack rate. 3 The combination of nifedipine and propranolol was shown to be effective with an increase in exercise time to angina and an increase in physical work capacity expressed in terms of calculated maximal oxygen uptake (VO2 max). There was an associated reduction in anginal attack rate. 4 The synergistic effect was even more pronounced after reduction in propranolol dosage to 50% of the beta-adrenoceptor blocking dose, reflecting the myocardial depressant effects of beta-adrenoceptor blocking drugs in these patients with coronary heart disease, some of whom had poor left ventricular function. [ABSTRACT FROM AUTHOR]

A highly stereocontrolled synthesis of (+)-chamuvarinin has been completed in 1.5% overall yield over 20 steps. The key fragment coupling reactions were the addition of alkyne 8 to aldehyde 7 (under Felkin-Anh control), followed by the two step activation/cyclization to close the C20-C23 2,5-cis-substituted tetrahydrofuran ring and a Julia-Kocienski olefination at C8-C9 to introduce the terminal butenolide. The inherent flexibility of our coupling strategy led to a streamlined synthesis with 17 steps in the longest sequence (2.2% overall yield), in which the key bond couplings are reversed. In addition, a series of structural analogues of chamuvarinin have been prepared and screened for activity against HeLa cancer cell lines and both the bloodstream and insect forms of Trypanosoma brucei, the parasitic agent responsible for African sleeping sickness., (Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Younger, middle-aged, and older adults were asked to study 36 Chinese-English vocabulary pairs of different complexity levels from grids where presentation order was randomized and no information about item complexity was provided. Of interest was whether participants' item selection and study time allocation would initially favor simple items, as predicted by Metcalfe's (2002) region of proximal learning (RPL) model, or complex items, as suggested by the discrepancy reduction model (DRM; Nelson & Leonesio, 1988), when participants had to select items based on something other than similarity to English. Each age group gauged item complexity similarly and made a similar use of the RPL heuristic in initial selection and study behaviors. However, older adults were more likely to restudy and allocate more time to simpler items, suggesting that, at least for restudy, older adults particularly relied on the RPL heuristic. Results are discussed in terms of self-regulated learning models., (2013 APA, all rights reserved)

A stereocontrolled total synthesis of (+)-chamuvarinin, isolated from the root extract of Uvaria Chamae, utilizes a convergent modular strategy to construct the adjacently linked C15-C28 ether array, followed by a late-stage Julia-Kocienski olefination to append the butenolide motif. This constitutes the first total synthesis of (+)-chamuvarinin, defining the relative and absolute configuration of this unique annonaceous acetogenin.

5-Substituted and 5,5-disubstituted hydantoins are synthesised from the corresponding aldehydes or ketones, using a one-pot, gallium(III) triflate-catalysed procedure that is compatible with a range of substrates and solvents.

Aims/hypothesis: Lipids and lipoproteins, particularly triglyceride rich lipoproteins, could influence the development and progression of microalbuminuria in diabetes. Lipoprotein lipase gene variants have been found to correlate with lipid/lipoprotein concentrations, especially hypertriglyceridaemia. We assessed the influence of this gene on microalbuminuria in Type II (insulin-dependent) diabetes mellitus., Methods: Microalbuminuria was determined quantitatively in 386 sequential Type II diabetic patients by measurement of the albumin-to-creatinine ratio (ACR). DNA was analysed for two common intronic LPL single nucleotide polymorphisms (Pvu II, intron 6, and Hind III, intron 8), and three common exonic mutations (Asp(9)-Asn, exon 2, Asn(291)-Ser, exon 6, and Ser(447)-Ter, exon 9)., Results: Individuals with P (2) P (2) (Pvu II) and H (2) H (2) (Hind III) genotypes had significantly greater ACRs ( P(2)P(2) vs P(1)P(1)+ P(1)P(2), 5.0+/-0.5 vs 3.4+/-0.3, p=0.0004 and H(2)H(2) vs H(1)H(1)+ H(1)H(2), 4.3+/-0.4 vs 3.4+/-0.3, p=0.04). Logistic regression analysis demonstrated that only the P(2)P(2) genotype ( p=0.0004), systolic BP ( p=0.008) and creatinine ( p=0.031) were independently associated with the presence of microalbuminuria/proteinuria. P(2) homozygotes were 170% more likely to have microalbuminuria or proteinuria, O.R. 2.7 (1.6-4.5, p=0.0001), 150% more likely to have microalbuminuria, O.R. 2.5 (1.5-4.3, p=0.001), and 330% more likely to have proteinuria, O.R. 4.3 (1.6-11.4, p=0.004). There were no associations of microalbuminuria with any of the exonic polymorphisms., Conclusion/interpretation: Genetic variants of lipoprotein lipase correlate with presence and severity of microalbuminuria in Type II diabetes, independent of effect on serum lipids. This association is only apparent in genetic variants demonstrating greatest heterozygosity.

Objective: Endoscopic trans-thoracic sympathectomy is a well documented, safe and successful treatment for palmar and axillary hyperhidrosis. This may also be helpful in the management of patients with intractable angina and advanced coronary disease unsuitable for coronary artery bypass graft (CABG) or percutaneous transluminal coronary angioplasty (PTCA). We evaluated video assisted thoracoscopic sympathectomy (VATS) in such patients with the aim of improving symptoms and quality of life., Methods: Video assisted thoracoscopic sympathectomy, a minimally invasive procedure, was performed under general anaesthesia with alternating single lung ventilation. Three stab incisions were made at the level of the fourth intercostal space in the anterior and posterior axillary lines, and at the fifth intercostal space in the mid-axillary line through which an extensive thoracic sympathectomy was performed to include second to the fourth ganglia, bilaterally., Results: A total of 16 patients aged 46-76 (mean 61) years were assessed for VATS. Of these 10 patients had the procedure performed; nine with previous CABG and one with diffuse coronary disease. Six patients were excluded because of an evolving MI (n = 1), left ventricular ejection fraction (LVEF) < 30% (n = 2), and chronic stable angina with no objective evidence of ischaemia (n = 3). All 10 patients had marked symptomatic improvement with reduction of both angina frequency and intensity of attacks. Mean follow-up period 11.5 months. Exercise tolerance and time to onset of angina measured on exercise treadmill was significantly increased post-VATS (P = 0.028) and maintained 1 year post-operative., Conclusion: VATS was associated with both reduction in angina symptoms and an increase in exercise time to onset of angina. An improved quality of life was evident.

Reviews of scientific literature began to appear in the 17th century. Journals dedicated to them soon followed, leading eventually to this one, which emerged in the 1930s as Bacteriological Reviews; it adapted to the many changes in our fluid discipline, evolving into the present, much broader Microbiology and Molecular Biology Reviews.

The International Committee on Systematic Bacteriology recommended that the category Candidatus, recently proposed by Murray and Schleifer (Int. J. Syst. Bacteriol. 44:174-176, 1994) to record the properties of putative taxa of procaryotes, should be implemented. This category should be used for describing procaryotic entities for which more than a mere sequence is available but for which characteristics required for description according to the International Code of Nomenclature of Bacteria are lacking. In addition to genomic information, such as sequences apt to determine the phylogenetic position of the organism, all information, including structural, metabolic, and reproductive features, should be included in the description of a provisional taxon, together with the natural environment in which the organism can be identified by in situ hybridization or other similar techniques for cell identification.

There has been some debate on usefulness of the exercise test in risk stratification after myocardial infarction in the thrombolytic era. This was assessed in 295 patients of whom 184 were treated with thrombolysis. Each had an exercise test using a modified Naughton protocol within 14 days of acute myocardial infarction. The tests were graded as high risk positive (112), low risk positive (83), or negative (100). These gradings predicted use of multiple drug therapy (p = 0.05), severity of coronary artery disease (p < 0.01), and coronary artery bypass grafting (p < 0.01). There was no influence on heart failure, recurrent myocardial infarction or death. This was independent of the use of thrombolytic therapy. The whole group had a good prognosis with a mortality of 2.4% after 56 weeks' follow-up. The exercise test is still a useful screening test after myocardial infarction. In this study, there was a high negative predictive accuracy of 91% for any event. Its use is not altered by thrombolysis. The finding of a lack of influence of the exercise test on major events may be a reflection of the current good prognosis after myocardial infarction and the prompt use of revascularisation.

Leptotrichia buccalis shows a mosaic of surface structure on its outer membrane consisting of curved ridges 35 mm high and 22 nm apart, and erect on that surface. Fimbriae (common pili) are not present and nor is an S layer. The flap-like ridges consist of strings of macromolecules radiating from the cell surface. This ridge structure is not soluble in any of the usual chaotropes and can only be released when the outer membrane has been damaged or dispersed by extracting envelope preparations with 0.5% SDS at room temperature. The ridge is then found to be attached firmly to the peptidoglycan sacculus, which may be the point of origin of the structure. When so prepared the macromolecules forming the ridge can be removed from the sacculus by treatment with 6 M guanidine HCl, and SDS-PAGE analysis of the extract reveals a 210-kDa polypeptide as a major component and a 15-kDa minor component. The latter is probably a peptidoglycan-associated protein and much of it remains with the sacculus. Each string forming the ridge is of a volume consistent with being made of three elongated 210-kDa molecules, which are united in series by strong hydrophobic association and laterally with neighboring strings by slightly weaker forces. We confirm that L. buccalis causes haemagglutination and the bacteria are known to attach to various tissue cells. Human group A red blood corpuscles remove both of the proteins from solution, which supports the hypothesis that the ridges are adhesin structures. It is likely but not proven that the 210-kDa molecule is the adhesin.

A case of anomalous origin of the left coronary artery from the pulmonary trunk is reported. The patient, a 64-year-old woman, presented with a history of angina and cardiac failure. She was known to have had a mitral systolic murmur since school age. Echocardiography showed clinically significant mitral regurgitation and highly unusual extensive calcification of the mitral valve chordae, papillary muscle, and posterior left ventricular wall--a pattern suggesting the possibility of abnormal coronary circulation. Subsequent cardiac catheterisation confirmed considerable mitral regurgitation with a dilated left ventricle, and arteriography confirmed anomalous origin of the left coronary artery from the main pulmonary trunk. The patient was surgically treated with ligation of the origin of the anomalous left coronary and mitral valve replacement. She was alive and well 2 years after operation.

The problem that the proposal for recording the properties of putative taxa of procaryotes attempts to redress arises because the International Code of Nomenclature of Bacteria is not able to provide sensible regulation of nomenclature for new taxa defined by very limited data, such as a nucleotide sequence for a small portion of the genome. The constructors of the original code (1957) and the Judicial Commission considering the 1976 and 1990 revisions did not foresee or act upon the possibilities for molecular description and typification of procaryotes that were not yet cultivable. As a result, formal names are being proposed for uncultivated procaryotes whose uniqueness is defined only by very limited characteristics, such as differences in a molecular sequence. As the editors of two journals concerned with the systematics of procaryotes, we recognize that the problem will increase as the available technology gains wider use and becomes easier to apply. Accordingly, this note is presented in advance of discussions by the International Committee on Systematic Bacteriology at the forthcoming congress (July 1994) so that there may be discussions and reaction by colleagues.

The fine structure of the taste buds of circumvallate papillae of two strains of mice was studied by electron microscopy. Mice anesthetized with ketamine were perfused through the heart with a double aldehyde mixture in cacodylate buffer and the tissues embedded in Epon. Semi-serial sections were employed. The morphology and relationships of cell types are consistent with the majority of descriptions of mammalian taste buds served by the ninth cranial nerve. Cells of type II are particularly well documented, as the stages in their origin, maturation and degeneration could be followed. Significant differences, however, relate to cell type I. These cells contain large dense-cored granules, contrasted with the more irregular and somewhat larger dark granules of the type I cells in the rabbit. These granules do not produce a dense homogenous product for the pore, as seen in the rabbit. Rather the pore substance consists of small, empty vesicles in a diffuse dark matrix. These granules are only moderately larger than the dense-cored vesicles of the type III cells. All features of the type III cell were demonstrated, although no instance of a complete cell was seen in any section. No significant differences were noted between the two strains of mice. Intimate proximity of a nerve to a cell nucleolus, suggestive of a trophic pathway, is illustrated.

We have investigated prospectively the serum cortisol response to acute myocardial infarction in 70 consecutive patients admitted to a coronary care unit and we have shown that the levels are significantly raised early in the course of the illness and prior to elevation of the cardiac specific enzyme fraction, creatine kinase MB. The magnitude of the cortisol response is related to the size of the ensuing infarction (rs = 0.54) as calculated from the total creatine kinase MB release (P < 0.001) and very high levels (> 2000 mumol/l) are predictive of mortality (P < 0.05). Serum cortisol levels may have a role in the early identification of myocardial infarction and in predicting those patients with a poor prognosis.

Nineteen new Deinococcus isolates from soil, 18 of which were from samples immediately adjacent to a lake in Nottingham, UK, were characterized by conventional criteria, and found to be identical to each other and to conform most closely to the species D. radiopugnans. However, we detected three different restriction enzyme activities in three different isolates. Because of this suggestion of heterogeneity, we examined the isolates for restriction fragment length polymorphisms (RFLPs). RFLP analysis of the 19 original isolates, using three different probes, distinguished 17 divergent groups. This extraordinary diversity cannot be attributed to geographical differences, nor to the method of isolation, which employed UV-radiation selection.

Xamoterol, a new beta 1 partial agonist, has the potential to modulate cardiac response to variations in sympathetic tone in patients with heart failure. Its properties should result in beta-receptor stimulatory effects at low levels of sympathetic tone and beta-receptor protective effects at higher levels of sympathetic tone. The acute effects of intravenous (i.v.) xamoterol on hemodynamics at rest and during exercise were studied in 30 patients with mild to moderate heart failure (13 patients in New York Heart Association class II; 17 in class III) due to ischemic (n = 24) or cardiomyopathic (n = 6) heart disease. Cardiac index, stroke volume and stroke work index at rest were significantly improved after i.v. administration of xamoterol and consistent with net agonist effects. During exercise, heart rate and double product were significantly reduced (net antagonist effects), but with preservation of the expected increases in cardiac index and systolic blood pressure. These hemodynamic findings confirm the ability of xamoterol to modulate cardiac response to variations in sympathetic tone. Tachyphylaxis and arrhythmogenicity limit the chronic use of drugs with full beta-agonist properties as positive inotropes in heart failure. The patients were therefore entered into a 6-month double-blind, placebo-controlled, crossover study of chronic oral xamoterol therapy, 200 mg twice daily, and the hemodynamic responses to i.v. xamoterol were repeated at the end of the trial. No impairment in either resting or exercise effects was observed, indicative of a maintained response and absence of tachyphylaxis after chronic therapy. Furthermore, 24-hour ambulatory electrocardiographic monitoring showed no change in ventricular arrhythmias during oral treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

Dopexamine hydrochloride is a novel compound with properties of DA1-dopaminergic and beta 2-adrenergic receptor agonism and neuronal noradrenaline uptake inhibition. It has been shown to produce beneficial renal and haemodynamic effects in patients with severe heart failure. We compared the haemodynamic effects of dopexamine (0.5 to 6 micrograms/kg/min) with those of dobutamine (5 to 25 micrograms/kg/min) in 9 patients with severe congestive heart failure. The two drugs were similar in their effects at peak infusion rates: heart rate increased (dopexamine 87 +/- 17 to 100 +/- 14; dobutamine 91 +/- 18 to 103 +/- 17 min-1), cardiac index increased (dopexamine 1.7 +/- 0.5 to 2.8 +/- 1.1; dobutamine 1.8 +/- 0.5 to 3.0 +/- 1.1 l.min-1.m-2) and systemic vascular resistance decreased (dopexamine 1553 +/- 221 to 1117 +/- 432; dobutamine 1721 +/- 347 to 1280 +/- 433 dyne.s.cm-5). Neither drug affected pulmonary artery wedge pressure (dopexamine 24 +/- 6 to 22 +/- 6; dobutamine 25 +/- 9 to 24 +/- 10 mm Hg). Dopexamine had significantly lower peak effects on left ventricular stroke work index (dopexamine 20 +/- 9, dobutamine 27 +/- 15 g.m.m-2, P less than 0.05) and cardiac power output (dopexamine 0.71 +/- 0.36, dobutamine 0.93 +/- 0.46 W, P less than 0.05). These haemodynamic effects, due largely to vasodilatation but with some contributory positive inotropy, indicate that dopexamine will be useful in the acute treatment of congestive heart failure.

The Proteobacteria are physiologically and morphologically diverse, although they form a coherent set of four main lineages on phylogenetic analysis of ribosomal RNA. A rational and consistent taxonomic arrangement bringing today's phenotypic and phylogenetic conclusions about them into register is not yet possible. It is also difficult to understand the selective forces involved in their evolution that fostered such diversity. This latter problem is addressed in this essay and is based on the assumption that bacterial evolution could only have occurred in ecological consortia whose products of metabolism modified the environment, provided nutrition, and have a basis for selection of new capabilities.

A major concern with the use of oral inotropes in chronic heart failure is their propensity to exacerbate cardiac arrhythmias. In a double-blind randomized placebo-controlled crossover study of xamoterol, a novel beta 1-partial agonist, 24 h ambulatory electrocardiograms were obtained in 26 patients prior to and at the end of 13-week treatment periods. During treatment with xamoterol there was no significant change in mean hourly number of ventricular extrasystoles compared with baseline and placebo (30 +/- 17 vs 56 +/- 42 and 18 +/- 7, respectively), or in the number of patients showing complex forms (multiform VEs, pairs, ventricular tachycardia) (20/26 vs 19/26 and 19/26, respectively), or ventricular tachycardia alone (5/26 vs 4/26 and 6/26, respectively). Xamoterol therapy also stabilized heart rate variability over the 24 h period.

The outermost component of the S layer of Lampropedia hyalina, the punctate layer, is assembled onto an inner perforate layer. The punctate layer is composed of long, tapered cylindrical units centered on p6 symmetry axes and connected by six fine linking arms, joining at the axis of threefold symmetry to create a hexagonal layer with a lattice constant of 25.6 +/- 0.5 nm (J. A. Chapman, R. G. E. Murray, and M. R. J. Salton, Proc. R. Soc. London Ser. B 158:498-513, 1963; R. G. E. Murray, Can. J. Microbiol. 9:593-600, 1963). Extraction of cell envelopes with 100 mM Tris buffer (pH 8) containing 2% deoxycholate resulted in the release of several proteins, but left the S layers intact. The punctate layer was then extracted with 3 M guanidine hydrochloride or 6 M urea, leaving the perforate layer intact. This treatment led to the release of three polypeptides with molecular weights of 60,000, 66,000, and 240,000 (60K, 66K, and 240K polypeptides). These three polypeptides reassembled on the perforate layer as a template to form the S-layer complex or self-assembled to form the punctate layer alone after dialysis of the extract against 50 mM HEPES (N-2-hydroxyethylpiperazine-N'-2-ethanesulfonic acid) buffer (pH 7.5) containing 10 mM CaCl2. The self-assemblies were composed of a 240K polypeptide and a 60K polypeptide. The 240K and 60K polypeptides were separated by column chromatography and examined by electron microscopy. The 240K polypeptide appeared in negative stain as a long, flexible structure and assembled into loose arrays with sixfold symmetry with obvious Y-shaped linking elements, while fractions containing both the 60K and 240K polypeptides showed assemblies closely resembling the punctuate layer. Immunoelectron microscopy was used to confirm the presence of both the 60K and 240K polypeptides as components of the punctuate layer.

Aquaspirillum sinuosum cell walls bear two paracrystalline, proteinaceous surface layers (S layers). Each shows a different symmetry: the inner layer is closely apposed to the outer membrane and is a tetragonal array (90 degrees axes; 5-nm units; repeat frequency 8 nm); the outer layer is a hexagonal array on the external surface (14-nm units; repeat frequency 18 nm) and, although the units have a six-pointed stellate form, the linkage between units is not resolved. The outer layer consists of a major 130-kDa protein and a 180-kDa minor component; these co-extract, co-assemble, and are inseparable by hydroxylapatite chromatography or by recrystallization. The solubilizing effects of reagents suggest stabilization by hydrogen bonding and Ca2+. The two outer layer proteins are serologically related and show partial identity by peptide mapping. Periodic acid--Schiff staining of the 180-kDa band suggests that this may be a glycosylated form of the 130-kDa component. The inner layer components form a doublet of 75- and 80-kDa polypeptides with extreme resistance to extraction. Close apposition to the outer membrane, resistance to chaotropes, aqueous insolubility, and behaviour in charge-shift electrophoresis suggest hydrophobic interaction between subunits and an integral association with the outer membrane.

The short and long term effects of successful percutaneous transluminal coronary angioplasty on left ventricular function, at rest and on exercise were investigated in 49 patients. Thirty-four had had no previous infarction (group 1) and 15 had (group 2). Technetium-99m gated blood pool images were obtained at rest and during exercise before, six weeks after, and a mean of fifteen months after successful angioplasty. Before angioplasty the mean (SD) ejection fraction fell significantly on exercise in both groups from 58 (10)% to 53 (13)% in group 1 and from 48 (10)% to 40 (16)% in group 2. This change was paralleled by a worsening wall motion score (from 0.6 (0.4) to 1.6 (1.2) in group 1 and from 2.3 (1.9) to 3.3 (2.4) in group 2). Six weeks after the procedure there was little change in resting ejection fraction but it increased significantly on exercise (to 62 (11)% in group 1 and to 53 (13)% in group 2). There was a concomitant significant improvement in the exercise wall motion score (to 0.4 (0.6) in group 1 and to 1.8 (1.1) in group 2). This improvement in exercise ejection fraction and wall motion was maintained at later follow up with no significant deterioration in either variable and a clearly sustained improvement in ejection fraction (60 (10)% in group 1 and 51 (10)% in group 2) and wall motion score (0.2 (0.2) in group 1 and 1.3 (0.8) in group 2) compared with values before angioplasty. The initial improvement in left ventricular function on exercise after successful angioplasty was maintained for at least 9-24 months both in patients with previous myocardial infarction and in those without.

The exercise test characteristics, coronary anatomy, and prognosis of patients discharged after non Q wave myocardial infarction were compared with those in whom Q wave infarction occurred. Of the 339 patients studied, all of whom were less than or equal to 70 years, 87 (26%) had had a non Q wave infarction. There were no significant differences in the exercise test characteristics between the two groups, and in those 149 patients in whom angiography was performed triple vessel disease was present in 36/114 (32%) of the Q wave group and 9/35 (26%) of the non Q wave group. The infarct related artery was more often patent in the non Q wave group (27/35 (77%] than in the Q wave group (53/114 (46%]. The one year mortality and the reinfarction and angina rates were similar in the two groups and the exercise test remained a good discriminator for predicting patients at risk of future cardiac events in both groups. In view of the similar outcome and severity of coronary disease in those aged less than or equal to 70 with non Q wave infarcts, the distinction between Q and non Q wave infarction need not influence management decisions in patients after myocardial infarction.

Sections and freeze-fractured preparations showed an S layer on the surface of Pseudomonas-like strain EU2. Polyacrylamide gel electrophoresis of cell envelopes extracted with 1% sodium dodecyl sulfate (SDS) at room temperature showed three proteins (45K, 55K, and 110K). The 55K protein was identified as the S-layer protein. Incubation in 1.5 M guanidine hydrochloride removed the S layer from cell envelopes and dissociated the structure into subunits. The soluble 55K protein reassembled into planar sheets upon removal of the guanidine hydrochloride by dialysis. Electron microscopy and image processing indicated that these sheets had p4 symmetry in projection with a lattice constant of 13.2 +/- 0.1 nm (corresponding to 9.3 nm between adjacent fourfold axes). In some instances these reassemblies appeared to form small three-dimensional crystals which gave particularly clear views of the structure in projection because of the superimposition of information from a number of layers. A model is proposed with molecules having rounded lobes connected by a narrower linker region and joining at the lobes to form the fourfold axes of the array. The pattern superficially resembles those of other bacterial S layers, such as those of Aeromonas salmonicida, Aeromonas hydrophila, and Azotobacter vinelandii. Extraction of cell envelopes with 1% SDS at 50 degrees C released the 110K protein from the envelopes and removed an amorphous backing layer from the S layer. The 45K protein displayed heat-modifiable migration in SDS-polyacrylamide gel electrophoresis and was insoluble in SDS at 50 degrees C or in high concentrations of guanidine hydrochloride, suggesting that it was associated with the peptidoglycan.

Thrombolytic therapy has been one of the most important advances in the field of cardiovascular medicine. Several agents are available and research is continuing to develop new effective thrombolytics with a rapid onset of action. The efficacy of thrombolytic therapy can be evaluated by a number of criteria such as the reperfusion time, the incidence of coronary recanalisation, left ventricular function, and survival. Survival is certainly the parameter of choice for assessing any thrombolytic protocol. The aim of this paper is therefore to review the results of survival studies with Eminase, one of the new thrombolytic agents used in the treatment of acute myocardial infarction.

Cardiac haemodynamics are deranged in chronic heart failure but fail to predict the exercise capacity of the patient. Cardiac power output is a descriptor of cardiac function derived from preload, blood pressure and cardiac output. Forty-one patients with moderately severe and severe chronic heart failure were exercised on a cycle ergometer to determine the relationship between traditional haemodynamics and cardiac power output and exercise capacity. Resting cardiac power output was no more predictive of exercise capacity than resting stroke-work index or resting cardiac index (r = 0.53, 0.61 and 0.51 respectively). Maximum cardiac power output and the ability to increase cardiac power output, however, were correlated with exercise capacity (r = 0.79 and 0.80). It is concluded that resting cardiac power output does not predict subsequent exercise capacity but that maximum cardiac power output and the ability to increase cardiac power output on stimulation are good descriptors of functional cardiac reserve.

Cells of Bacillus subtilis, when suspended in a 5mM metal solution, bind metals tenaciously to their cell walls. These metal-loaded cells, when mixed with a synthetic sediment and put under laboratory conditions to simulate low-temperature sediment diagenesis, nucleate the formation of a mixed assemblage of crystalline metal phosphates, metal sulfides, and polymeric, metal-complexed, organic residues. The sequential series of diagenetic events leading to the formation of authigenic mineral phases was followed by transmission electron microscopy and energy-dispersive X-ray analysis. The minerals quartz (SiO(2)) and calcite (CaCO(3)) were employed in the synthetic sediment. Crystalline magnetite (Fe(2)O(3)) and elemental sulfur were added as redox buffering agents to ensure anoxic conditions. Quartz and magnetite appeared unreactive throughout the experimental conditions. Elemental sulfur interacted with the metal-loaded cells, affected both the eventual chemistry and crystal habit of the metal phosphates, and formed a variety of crystalline metal sulfides. Calcite raised the pH of the fluid phase of the sediment, which influenced phosphate mineralization and inhibited metal sulfide genesis.