The biogeography and phylogeny of unicellular cyanobacterial symbionts in sponges from Australia and the Mediterranean.

The distribution, host associations, and phylogenetic relationships of the unicellular cyanobacterial symbionts of selected marine sponges were investigated with direct 16s rDNA sequencing. The results indicate that the symbionts of the marine sponges Aplysina aerophoba, Ircinia variabilis, and Petrosia ficiformis from the Mediterranean, four Chondrilla species from Australia and the Mediterranean, and Haliclona sp. from Australia support a diversity of symbionts comprising at least four closely related species of Synechococcus. These include the symbionts presently described as Aphanocapsa feldmannii from P. ficiformis and Chondrilla nucula. A fifth symbiont from Cymbastela marshae in Australia is an undescribed symbiont of sponges, related to Oscillatoria rosea. One symbiont, Candidatus Synechococcus spongiarum, was found in diverse sponge genera in the Mediterranean Sea and the Indian, Pacific, and Southern oceans, whereas others were apparently more restricted in host association and distribution. These results are discussed in terms of the biodiversity and biogeographic distributions of cyanobacterial symbionts.

Intraoperative transoesophageal echocardiography: impact on adult cardiac surgery.

Although multiple case reports have demonstrated the capability of transoesophageal echocardiography (TOE) to detect unsuspected cardiac pathology with important therapeutic implications, few studies have examined the effect of real-time interpretation of routine TOE on clinical management of a typical series of cardiac surgery patients. To assess the impact of intraoperative TOE on cardiac surgical management, we conducted a prospective observational study on 238 consecutive patients undergoing intraoperative TOE during adult cardiac surgery. Potentially important new diagnostic information was detected in 39 of 184 (21%) routine and in 53 of 54 requested TOE examinations, and led directly to different surgical procedures in 11 of 184 (6%) routine and in 12 of 54 (22%) requested TOE examinations. Our data suggests that intraoperative TOE may be a valuable tool in the routine management of adult cardiac surgical patients.

Enhancement of T cell-independent immune responses in vivo by CD40 antibodies.

In this report we describe a potentially powerful method for vaccinating infants against encapsulated bacterial pathogens such as Haemophilus influenzae, Streptococcus pneumoniae and Neisseria meningitidis. High levels of antibody directed against the polysaccharides of the bacterial capsule are normally protective. Unfortunately, the capsular polysaccharides are T cell-independent antigens (TI); lacking T-cell help, they induce only weak, predominantly IgM antibody responses, with infants responding especially poorly. T-cell help, given to B cells during responses to protein antigens, causes stronger antibody responses and isotype switching to the IgG isotypes. T-cell help is mainly mediated through ligation of the B-cell surface antigen, CD40, by its cognate T-cell ligand, CD154. Here we show that administering anti-CD40 monoclonal antibody to mice, along with pneumococcal polysaccharide, provides a substitute for T-cell help and results in the generation of strong, isotype-switched antibody responses, which are protective. The work points the way toward a possible effective and inexpensive means of protecting susceptible groups against important bacterial pathogens.

Continuous passive motion after total knee arthroplasty. Analysis of cost and benefits.

The authors report the results of a prospective study examining the benefits of daily continuous passive motion combined with physical therapy, compared with physical therapy alone, in 103 consecutive osteoarthritic patients undergoing primary total knee arthroplasty. The first 51 patients received continuous passive motion initiated in the recovery room and the next 52 patients did not receive continuous passive motion. Both groups underwent an identical physical therapy protocol starting on the first postoperative day. At discharge, there was a significant increase in active flexion in the continuous passive motion group. There were no significant differences regarding pain, wound healing, knee swelling, wound drainage, pulmonary embolism, or length of hospital stay between the 2 groups. At 2 years, there were no clinical differences in the motion or knee scores. Knee manipulation was done for < 50 degrees flexion after the tenth postoperative day. There were 5 manipulations in the noncontinuous passive motion group and none in the continuous passive motion group. The entire costs associated with the 5 manipulations was $48,274 or $937 per patient not receiving continuous passive motion. The average daily inpatient rental of the machine was $60 per day. Continuous passive motion is efficacious in increasing short-term flexion and decreasing the need for knee manipulation without increasing costs.

Flow reversal in the descending aorta: a guide to intraoperative assessment of aortic regurgitation with transesophageal echocardiography.

This study assessed the value of biplane transesophageal echocardiographic assessment of diastolic flow reversal in the descending aorta as an alternative to Doppler color flow imaging in determining severity of aortic regurgitation. In 45 patients undergoing cardiac operations, the severity of aortic regurgitation was assessed by semiquantitative grading of the width of the Doppler color flow regurgitant jet relative to the left ventricular outflow tract, and the presence of diastolic flow reversal was assessed with pulsed-wave Doppler measurements at three sites in the descending aorta. In four patients, the diastolic flow reversal method was the only available form of assessment because of inadequate visualization of the left ventricular outflow tract beneath a mitral valve prosthesis. Diastolic flow reversal in the descending aorta was not observed in patients without aortic regurgitation and was always present in patients with severe aortic regurgitation. Aortic valve replacement successfully eliminated descending aortic flow reversal in all 19 patients in whom it was present before valve replacement. Identification of diastolic flow reversal at multiple sites in the descending aorta with biplane transesophageal echocardiography helps to confirm the presence of severe aortic regurgitation and can serve as an alternative method of assessment when visualization of the left ventricular outflow tract is impaired.

Intraoperative assessment of left ventricular function with transesophageal echocardiography.

Qualitative TEE assessment is used to guide administration of fluids and inotropic drugs and to monitor left ventricular function intraoperatively. Left ventricular hypovolemia or depression is easily recognized by directly noting a small end-diastolic area or low ejection fraction. Appropriate therapy can be instituted and continuously monitored. In contrast, pulmonary artery pressure monitoring does not accurately indicate loading conditions during major cardiovascular procedures or whenever left ventricular compliance is impaired, mitral valve dysfunction is present, or right ventricular distention occurs. New applications and technical improvements in TEE are being developed at a remarkable rate. Future versions of ABD technology are likely to address the problem of anisotropy, require less user intervention, and incorporate 3-D information from multiplane probes to produce real-time estimates of left ventricular volumes. The raw information in the returning signal will most likely be further analyzed to allow characterization of ischemic but still viable tissue. Coupled with the ability to assess regional myocardial perfusion by contrast echocardiography, the clinician will be able to institute more timely and appropriate medical and surgical therapy. TEE assessment of mitral valve function has become the standard of care after mitral valve repair, and in a similar fashion, assessment of myocardial perfusion by TEE may become the standard of care during cardiac and major noncardiac surgery.

Evaluation of the genus Listonella and reassignment of Listonella damsela (Love et al.) MacDonell and Colwell to the genus Photobacterium as Photobacterium damsela comb. nov. with an emended description.

The genus Listonella, which was recently described on the basis of 5S rRNA sequence data, was found to be of dubious value on the basis of the results of a comparison of a number of taxonomic studies involving members of the Vibrionaceae. The available data suggest that 5S rRNA sequences may be of limited taxonomic use at the intra- and intergeneric levels, at least for apparently recently evolved groups, such as the Vibrionaceae. In this light, we assessed the generic assignment of the species Listonella damsela. Phenotypic characterization of 12 strains of bacteria assigned to L. damsela, including type strain ATCC 33539, revealed a strong resemblance to members of the genus Photobacterium. All of the strains conformed to major characteristics common to all known Photobacterium species. The characteristics of these organisms included the absence of a flagellar sheath and accumulation of poly-beta-hydroxybutyrate during growth on glucose coupled with the inability to utilize DL-beta-hydroxybutyrate as a sole carbon source. On the basis of the phenotypic data, we propose that L. damsela should be reassigned to the genus Photobacterium as Photobacterium damsela comb. nov.

Distribution and physiology of aerobic bacteria containing bacteriochlorophyll a on the East and west coasts of australia.

Aerobic heterotrophic bacteria containing bacteriochlorophyll were isolated from specimens from a wide variety of marine environments on the west (Shark Bay, Lake Clifton, Lake Heyward, and Perth) and east (near Townsville and Brisbane) coasts of Australia. The bacteria were found in a high proportion (10 to 30%) of the total heterotrophic bacterial strains isolated from marine algae, seagrasses, stromatolites, the epiphytes on stromatolites, seawater, and sands; in some cases they constituted up to 49% of the total. This is much higher than the previous report of 6% from Japan. A high percentage, 13%, was also found in the seawater of Hamelin Pool, at Shark Bay, where the salinity was 66%. The number of these bacteria was generally low in seawater and sands, with a few exceptions. There were no aerobic bacteriochlorophyll-containing bacteria on sponges or corals. The isolated strains were orange or pink, and most had absorption maxima around 800 and 850 to 870 nm, the latter range being the absorption of bacteriochlorophyll a in vivo. The maximum bacteriochlorophyll content was 1 nmol/mg (dry weight) of bacterial cells. Most of the bacteria did not grow phototrophically under anaerobic conditions in a broth medium containing succinate. Cells and cell extracts grown under aerobic conditions had photochemical activities such as reversible photooxidations of the reaction center and cytochrome(s). Some strains showed denitrifying activity. The optimal salinity for bacterial growth varied between strains.

Host-Zooxanthella Interactions in Four Temperate Marine Invertebrate Symbioses: Assessment of Effect of Host Extracts on Symbionts.

Photosynthesis and translocation of photosynthetic products from symbiotic zooxanthellae in four species of temperate-latitude invertebrates were investigated in vivo and in vitro. In vivo, zooxanthellae fixed 14C and translocated a substantial proportion of fixed products to host tissues. In vitro, the effect of host tissue extracts on isolated zooxanthellae varied. Extracts of the soft coral Capnella gaboensis, lysed zooxanthellae after a relatively short exposure. Those of the zoanthid Zoanthus robustus and the nudibranch Pteraeolidia ianthina had little effect on translocation of organic carbon from zooxanthellae. In contrast, host extract of the scleractinian coral Plesiastrea versipora stimulated the release of up to 42% of the total 14C fixed, and the magnitude of release was positively correlated with the protein concentration of the extract. Host extracts had no effect on photosynthetic rates in algal symbionts. The effect of P. versipora extract on isolated zooxanthellae was studied. This extract caused zooxanthellae to divert photosynthetic products from lipid synthesis to the production of neutral compounds, principally glycerol, and these compounds were the predominant form of carbon detected extracellularly after incubating zooxanthellae in this extract. Only organic compounds made during the period of exposure of zooxanthellae to host extract, and not pre-formed photosynthetic products, were translocated. The translocation-inducing activity of host extract was almost completely destroyed by heating (100{deg}C), and a preliminary attempt to fractionate the tissue extract revealed that the active constituent did not pass through dialysis tubing of nominal pore size 10,000 D. These results are discussed in relation to host control of symbiotic partners, and to previous reports of "host-release factors" in other invertebrate symbioses.

Determination of cadmium and lead in urine and other biological samples by graphite-furnace atomic-absorption spectrometry.

A method for determining cadmium and lead in urine and other biological samples by graphite-furnace atomic-absorption spectrometry is reported. Samples were analysed after wet or dry ashing and without extraction or matrix-modification techniques, in laminar-flow clean-room; negligible blank contributions were found. Matrix interference effects were observed only for lead and were resolved by the method of standard additions. Five NBS biological reference materials were used as internal quality-control standards. The urinary levels for non-exposed volunteers ranged from 0.16 +/- 0.01 to 1.65 +/- 0.20 and from 6 +/- 1 to 31 +/- 6 ng/ml for cadmium and lead, respectively; this corresponds to 0.15 +/- 0.02 to 2.01 +/- 0.16 and 7 +/- 1 to 31 +/- 3 mug/day. The average relative standard deviation for 60 urine samples was 10% for cadmium and 13% for lead.

Prediction and measurement of effect of chelating selectivity on precipitation reactions.

A theoretical treatment of precipitation equilibrium in the presence of a chelating agent has been expanded to include the common ion effect on precipitation reactions. The extent of precipitation can be predicted over the full range of pH for any metal for which the solubility product of the precipitate and the stability constants for a complex are known. The expanded equation has been used in this investigation to predict the extent of precipitation for several metals in the presence of ethylenediaminetetra-acetic acid (EDTA) with common précipitants such as hydroxide, oxalate, sulphate, sulphide and 8-hydroxyquinoline, but may be applied to any system containing other chelating agents. The limits of precipitation in terms of pM', the negative logarithm of the concentration of unprecipitated metal ion, are presented graphically as a function of pH for a system containing axed amounts of precipitating and complexing agents. Measurements for observed reactions at two pH levels, 5 and 10, are compared with the calculated predictions of the equation. Thirty-five metals were investigated.