First Report of Tomato yellow leaf curl virus Infecting Tomato, Tomatillo, and Peppers in Guatemala

In Guatemala and other Central American countries, whitefly-transmitted geminiviruses (begomoviruses) cause economically important diseases of tomato (Solanum lycopersicum) and pepper (Capsicum annuum). Disease symptoms include stunted and distorted growth and leaf curling, crumpling, light green to yellow mosaic, purpling, and vein swelling. In Guatemala, at least eight bipartite begomovirus species infect tomato or peppers (1), but their role and relative importance is unclear. As part of an Integrated Pest Management strategy to manage these diseases, surveys for begomovirus symptoms in pepper and tomato have been conducted in the Salama Valley, Sanarate, and other locations since 2003, and begomoviruses were identified by squash blot hybridization, PCR and DNA sequencing. Beginning in 2006, a new type of symptom, stunted upright growth and upcurled leaves with yellowing of the margins and interveinal areas, was observed in tomato and tomatillo plants in the Salama Valley and Sanarate. These symptoms were similar to those induced by the exotic monopartite begomovirus Tomato yellow leaf curl virus (TYLCV). Evidence that TYLCV caused these symptoms came from positive results in high stringency squash blot hybridization tests with a TYLCV probe, and amplification of the expected size of ~0.3- and 2.8-kb fragments in PCR tests with TYLCV capsid protein (CP) gene and full-length component primer pairs, respectively (3). Sequence analyses of PCR-amplified CP fragments and portions of full-length fragments revealed 97 to 99% identity with isolates of TYLCV-Israel (TYLCV-IL). The complete nucleotide sequence of an isolate from the Salama Valley (GenBank Accession No. GU355941) was >99% identical to those of TYLCV-IL isolates from the Dominican Republic, Florida, and Cuba and ~97% identical to those of isolates from Mexico and California. Thus, this TYLCV-IL isolate (TYLCV-IL[GT:06]) was probably introduced from the Caribbean Region. To further characterize begomoviruses in the Salama Valley, leaf samples were collected from 44 and 118 tomato plants showing symptoms of begomovirus infection in March 2006 and 2007, respectively, and from 106 symptomatic pepper plants in March 2007. Begomovirus infection was confirmed in 42 of 44 and 93 of 118 of the tomato samples and 100 of 106 of the pepper samples based on PCR amplification of the expected size of ~0.6- and 1.1-kb DNA fragments with the begomovirus degenerate primers pairs AV494/AC1048 and PAL1v1978/PAR1c496, respectively (2,4). Sequence analyses of cloned PCR-amplified fragments revealed that 3 of the 44 and 16 of the 118 tomato samples collected in 2006 and 2007, respectively, and 9 of the 106 pepper samples were infected with TYLCV based on >97% identity with TYLCV-IL. In all samples, TYLCV was present in mixed infections with other begomoviruses. The introduction of TYLCV adds to the already high level of genetic complexity of bipartite begomovirus infection of tomatoes and peppers in Guatemala and will undoubtedly complicate disease management efforts. References: (1) M. K. Nakhla et al. Acta Hortic. 695:277, 2005. (2) M. R. Rojas et al. Plant Dis. 77:340, 1993. (3) R. Salati et al. Phytopathology 92:487, 2002. (4) S. D. Wyatt and J. Brown. Phytopathology 86:1288, 1996.

Evaluation of continuous veno-venous hemofiltration for the treatment of cardiogenic shock in conjunction with acute renal failure after cardiac surgery

BACKGROUND

Cardiogenic dysfunction with acute renal failure (ARF) and diuretic drug resistance increases mortality after cardiac surgery with cardiopulmonary bypass (CPB) in adults. Until few years ago, intermittent renal replacement therapy (IRRT) was the only therapeutical strategy proposed to such patients. Few data are available in the literature regarding the use of continuous veno-venous haemofiltration (CVVH) in this clinical context. The aim of our observational study was to evaluate the impact of CVVH strategy on ARF in conjunction with cardiogenic shock after cardiac surgery and on its well-known associated poor outcome.

METHODS

During the period 2005-2006, we prospectively collected data from our database as we controlled the renal replacement therapy using CVVH (n=73). We also retrospectively collected data from our computerised database on patients who were treated with IRRT (n=68, period 2002-2003). Among CVVH-treated patients, a multivariate analysis of the data aimed to identify risk factors associated with 30-day mortality.

RESULTS

In patients who presented with ARF in conjunction with cardiogenic shock after cardiac surgery, 30-day mortality rate was 59% for the IRRT group and 42% for the CVVH group. Within the CVVH group, the logistic regression and multivariate analyses reported that some variables were associated with higher mortality risk: a score F concerning the urinary output criteria of the RIFLE (risk, injury, failure, loss, end-stage kidney disease) classification (for scores R or I: odds ratio (OR): 0.01, 95% confidence interval (95% CI): 0.02-0.59; p=0.01), plasma bilirubin (OR: 1.44, 95% CI: 1.12-1.84; p=0.04), total CVVH duration <50h over 72 h (>50h; OR: 0.009, 95% CI: 0.04-0.93; p=0.01), the need of catecholamine support (OR: 12.88, 95% CI: 1.95-84.96; p=0.01), tachycardia in the intensive care unit (ICU; OR: 1.64, 95% CI: 1.02-2.65; p=0.04), surgery duration (<300 min; OR: 0.11, 95% CI: 0.02-0.71; p=0.02) and combined cardiac surgery (OR: 7.00, 95% CI: 1.29-37.88; p=0.02).

CONCLUSION

In patients with ARF in conjunction with cardiogenic shock after cardiac surgery, renal replacement therapeutic strategy based on long-lasting CVVH could improve patients' outcome. The identification of risk factors associated with a poor outcome would help to better manage such patients in the ICU. Low total duration of CVVH within the first 72 h was one criteria related to poor outcome. This suggests that CVVH must be initiated as soon as possible when ARF with diuretic resistance occurs in patients after cardiac surgery and continued as long as possible for the first 3 days.

Assessing cardiovascular risk factors after coronary artery bypass surgery: value of an aggressive strategy including systematic follow-up

INTRODUCTION

Coronary revascularization surgery is a palliative treatment modality which should not preclude efforts to treat atherosclerosis.

AIM

To assess ongoing cardiovascular risk factors after coronary artery bypass surgery and develop a strategy to attenuate such factors.

METHODS

108 patients requiring a coronary artery bypass were included: 2 died soon after surgery and 6 were excluded for personal reasons. 100 patients were re-admitted into hospital 7 months after surgery for risk factor assessment. Eight months later, they were re-contacted by telephone (systematic follow-up) for a re-assessment.

RESULTS

The population consisted of 77 men with an average age of 64+/-11 years. Prior to the operation, the known risk factors were: smoking 34%; HBP 61%; cholesterol 47%; diabetes 30%; obesity 25%. During their hospital stay six months after the procedure: 91% of the patients had at least one lipid metabolism abnormality. New-onset diabetes was diagnosed in 5%. Blood pressure was uncontrolled in 18% and 10% were still smoking. Patients tended to be putting on weight and 55% engaged in little or no physical activity. Systematic follow-up: lipid metabolism had normalized in 70% of the patients. Blood glucose levels were significantly lower. Blood pressure was uncontrolled in 9% and 4% were still smoking. Their weight had stabilized and 65% were engaging in moderate-to-strenuous physical activity.

CONCLUSION

Inadequate attention is paid to risk factors after coronary artery bypass surgery. A short hospital stay including a cardiovascular evaluation and education about risk factors has a positive impact on the management of atherosclerosis in the medium term.

Off-pump coronary artery bypass surgery in very high-risk patients: adjustment and preliminary results

Left ventricle dysfunction and comorbidities are responsible for a large number of complications after CABG. OPCAB could be an interesting alternative for very high-risk patients. Patients were included if EuroSCORE >9, or with at least two of the following criteria, severe LV dysfunction, recent myocardial infarction (MI), terminal renal failure, lung dysfunction, PVD, BMI>30. Patients were operated using the Octopus (Medtronic) system. One hundred and twenty patients, mean age 68+/-10 years, 72% male, were operated. Mean EuroSCORE was 10.2+/-5.3, LV function 36.79+/-11.3%, recent MI 57%, renal failure 52%, COPD 44%, PVD 52%, obesity 34%. Mean graft per patient was 2.1+/-0.8. Three patients underwent secondary PTCA treatment for incomplete revascularization. Combined surgery was required for 20%. Early mortality was 3%. Intensive care unit stay was 2.7 days. Early complications were: low output syndrome 3%, MI 0.8%, stroke 0.8%, kidney support 7%. Graft patency was systematically analyzed with MCTA or angiocardiography. OPCAB strategy seems to be safe and secure in this population of very high-risk patients reducing multi-organ failure. However, long-term results are needed to confirm this strategy.

Validation of a continuous, arterial pressure-based cardiac output measurement: a multicenter, prospective clinical trial

Introduction

The present study compared measurements of cardiac output by an arterial pressure-based cardiac output (APCO) analysis method with measurement by intermittent thermodilution cardiac output (ICO) via pulmonary artery catheter in a clinical setting.

Methods

The multicenter, prospective clinical investigation enrolled patients with a clinical indication for cardiac output monitoring requiring pulmonary artery and radial artery catheters at two hospitals in the United States, one hospital in France, and one hospital in Belgium. In 84 patients (69 surgical patients), the cardiac output was measured by analysis of the arterial pulse using APCO and was measured via pulmonary artery catheter by ICO; to establish a reference comparison, the cardiac output was measured by continuous cardiac output (CCO). Data were collected continuously by the APCO and CCO technologies, and at least every 4 hours by ICO. No clinical interventions were made as part of the study.

Results

For APCO compared with ICO, the bias was 0.20 l/min, the precision was ± 1.28 l/min, and the limits of agreement were -2.36 l/m to 2.75 l/m. For CCO compared with ICO, the bias was 0.66 l/min, the precision was ± 1.05 l/min, and the limits of agreement were -1.43 l/m to 2.76 l/m. The ability of APCO and CCO to assess changes in cardiac output was compared with that of ICO. In 96% of comparisons, APCO tracked the change in cardiac output in the same direction as ICO. The magnitude of change was comparable 59% of the time. For CCO, 95% of comparisons were in the same direction, with 58% of those changes being of similar magnitude.

Conclusion

In critically ill patients in the intensive care unit, continuous measurement of cardiac output using either APCO or CCO is comparable with ICO. Further study in more homogeneous populations may refine specific situations where APCO reliability is strongest.

[Perioperative anticoagulation management for prosthetic heart valves]

OBJECTIVES

The practices and the guidelines over the perioperative management of the anticoagulation of patients with cardiac valves prothesis are the object of no consensual attitude. The thrombotic risk over the time is well known. It depends of the type or the location on the valve, of their associations and the age of the patient. In the perioperative period, the antithrombotic treatment must be interrupted according to the surgical haemorrhagic risk.

STUDY DESIGN

Short review.

RESULTS

Only patients, without associated risk factor, carriers of bioprosthesis from more than 3 months, can be maintained only under antiplatelets agents. In others situations, the caution imposes a bridge of anticoagulants from 48 to 72 hours with unfractionated heparin (subcutaneous at home, intravenous at the hospital). Low molecular weight heparin has no commercial authorization in this indication. The resumption of the anticoagulation by unfractionated heparin in postoperative period must be the most premature possible after the decrease of the surgical bleeding. The relay by vitamin K antagonists has to be made over 48 to 72 hours. Within the framework of the urgency, the surgical haemorrhagic risk is weak for an INR <1.5. According to the urgency of the surgery, a treatment by vitamin K (if the delay is over 12 hours) or by prothrombinic complex allows to correct this INR. The identification of thrombotic complications requires a particular attention. In the postoperative period, as soon as there is suspicion of thrombosis, clinical manifestations must be consolidated by the practice of a transoesophageal echography, which only confirm the diagnosis.

Phylogenetic relationships within the Mysidae (Crustacea, Peracarida, Mysida) based on nuclear 18S ribosomal RNA sequences

Species of the order Mysida (Crustacea, Peracarida) are shrimp-like animals that occur in vast numbers in coastal regions of the world. The order Mysida comprises 1,053 species and 165 genera. The present study covers 25 species of the well-defined Mysidae, the most speciose family within the order Mysida. 18S rRNA sequence analysis confirms that the subfamily Siriellinae is monophyletic. On the other hand the subfamily Gastrosaccinae is paraphyletic and the subfamily Mysinae, represented in this study by the tribes Mysini and Leptomysini, consistently resolves into three independent clades, and hence is clearly not monophyletic. The tribe Mysini is not monophyletic either, and forms two clades of which one appears to be closely related to the Leptomysini. Our results are concordant with a number of morphological differences urging a taxonomic revision of the Mysidae.

Dextran sulfate included in factor Xa assay reagent overestimates heparin activity in patients after heparin reversal by protamine

A lack of correlation between activated partial thromboplastin time (aPTT), thrombin time (TT) and anti-factor Xa (AXa) activity was observed in patients after cardiac surgery with cardiopulmonary bypass (CBP). Indeed, AXa activity measured by the chromogenic assay, Coamatic Heparin, was higher than expected with regard to results obtained in coagulation assays. To account for this discrepancy, another AXa chromogenic assay was tested. First, AXa activity was measured with two chromogenic assays (Coamatic Heparin and Rotachrom Heparin) in plasma samples of 25 patients undergoing cardiac surgery at two time points after heparin reversal by protamine. AXa activity was significantly higher when measured with Coamatic Heparin than with Rotachrom Heparin in samples collected just after protamine infusion (p<0.01). Next, since Coamatic( Heparin contains dextran sulfate (DXS) to reduce the influence of heparin antagonists such as platelet factor 4 (PF4), whereas Rotachrom Heparin does not, we hypothesized that the dextran sulfate contained in the reagent might explain this discrepancy. We therefore performed in vitro studies consisting in neutralizing unfractionated heparin (UFH) with protamine and measuring AXa activity with the two chromogenic assays. An AXa activity was still measurable with Coamatic Heparin after neutralization, thus strongly suggesting that dextran sulfate dissociates protamine/heparin complexes. We conclude that Coamatic Heparin assays should be avoided when measuring AXa activity in plasma samples immediately after protamine infusion, as inaccurate results may lead to inadequate management of heparin reversal.

Isolation, identification, and synthesis of a disulfated sulfakinin from the central nervous system of an arthropods the white shrimp Litopenaeus vannamei

Two myotropic peptides displaying tyrosyl sulfation have been isolated from an extract of central nervous systems (brain, suboesophageal ganglion, thoracic ganglia, and ventral nerve cord) of the white shrimp Litopenaeus vannamei. Both peptides were identified by mass spectrometry and belong to the sulfakinin family of neuropeptides, which are characterized by the C-terminal hexapeptide Y(SO(3)H)GHMRF-NH(2) preceded by two acidic amino acid residues. Pev-SK 1 (AGGSGGVGGEY(SO(3)H)DDY(SO(3)H)GH(L/I) RF-NH(2)) has two sulfated tyrosyl residues and a unique (L/I) for M substitution in the C-terminal sequence. Pev-SK 2 (pQFDEY(SO(3)H)GHMRF-NH(2)) fully complies with the typical sulfakinin core sequence and is blocked by a pyroglutamyl residue. Synthetic analogs (sulfated and unsulfated) were synthesized and the tyrosyl sulfations were confirmed by myotropic activity studies and co-elution with the native fractions. Pev-SK 1 is the first disulfated neuropeptide elucidated in the phylum of the arthropoda, with the only other reported disulfated neuropeptide, called cionin, found in a protochordate. The similarities in amino acid sequence and posttranslational modifications of the crustacean sulfakinins and protochordate cionin provide further evidence for the hypothesis stating that gastrin/CCK, cionin, and sulfakinins originate from a common ancestral gastrin/CCK-like peptide.

[Training for adult subclavian venous catheterization: use of real-time echography]

OBJECTIVE

To assess the training in adult subclavian venous catheterization of an inexperienced operator, with two different procedures: ultrasound guidance vs anatomic landmark technique.

STUDY DESIGN

Prospective, comparative study.

PATIENTS AND METHODS

After informed consent, 50 adults were divided in two groups, with an original method of inclusion, designed to assess the training of the operator, which alternated ultrasound guidance (n = 25) and Aubaniac's landmark technique (n = 25).

RESULTS

All the catheterizations have been completed. The success rate at first attempt was higher in ultrasound group than in landmark group, without reaching significance (76 vs 56%). Two arterial punctures were reported in landmark group. With ultrasound guidance, there were 21 puncture sites at the external third and 4 at the medial third of the clavicle. Average access time (skin to vein) was 15 +/- 8 seconds in ultrasound group and 63 +/- 78 seconds in landmark group (p < 0.01), with a significant relation between access time and patient rank in landmark group (r2 = 0.42, p < 0.01).

CONCLUSION

Ultrasound guidance makes the training in adult subclavian venous catheterization easier, and allows inexperimented operator to be rapidly efficient. The use of ultrasound would decrease the incidence of complications by a real time visualization of anatomical structures, and by a more external approach of the vein than in the Aubaniac's technique.

Soluble minerals in chemical evolution. I. Adsorption of 5'-AMP on CaSO4--a model system

The adsorption of 5'-AMP onto solid CaSO4 2H2O was studied in a saturated suspension as a function of pH and electrolyte concentration. The adsorption is pH-dependent and is directly correlated with the charge on the 5'-AMP molecule which is determined by the state of protonation of the N-1 nitrogen of the purine ring and the phosphate oxygens. It is proposed that the binding occurs between the nucleotide and the salt is electrostatic in nature. The adsorption decreases with increasing ionic strength of the solution which means that in a fluctuating environment of wetting and drying cycles, a biomolecule similar to 5'-AMP could be expected to desorb during the drying phase. The results indicate that CaSO4 2H2O can serve as a concentrating surface for biomolecules. The significance of this is discussed with regard to the possible role of soluble minerals and their surfaces in a geochemical model consistent with the evolution of the Earth and the origin of life.

Perception, attention, and working memory are disproportionately impaired in dementia with Lewy bodies compared with Alzheimer's disease

OBJECTIVE

To test the hypotheses that visuoperceptual and attentional ability are disproportionately impaired in patients having dementia with Lewy Bodies (DLB) compared with Alzheimer's disease (AD).

METHODS

A comprehensive battery of neuropsychological tasks designed to assess working, episodic, and semantic memory, and visuoperceptual and attentional functions was given to groups of patients with DLB (n=10) and AD (n=9), matched for age, education, and mini mental state examination (MMSE), and to normal controls (n=17).

RESULTS

Both patient groups performed equally poorly on tests of episodic and semantic memory with the exception of immediate and delayed story recall, which was worse in the AD group. Digit span was by contrast spared in AD. The most striking differences were on tests of visuoperceptual/spatial ability and attention. Whereas patients with AD performed normally on several subtests of the visual object and space perception battery, the DLB group showed substantial impairments. In keeping with previous studies, the AD group showed deficits in selective attention and set shifting, but patients with DLB were more impaired on virtually every test of attention with deficits in sustained, selective, and divided attention.

CONCLUSIONS

Patients with DLB have substantially greater impairment of attention, working memory, and visuoperceptual ability than patients with AD matched for overall dementia severity. Semantic memory seems to be equally affected in DLB and AD, unlike episodic memory, which is worse in AD. These findings may have relevance for our understanding of the genesis of visual hallucinations, and the differential diagnosis of AD and DLB.

Pulsed plasma deposition of allylamine on polysiloxane: a stable surface for neuronal cell adhesion

Allylamine was pulse-plasma polymerized onto a hydrophobic polysiloxane substrate to create cell adhesion surfaces for cell culture that would not require pretreatment with polylysine, could be sterilized via autoclaving, and could be re-used for several culture cycles. We investigated two different plasma deposition protocols at 200 W RF power: (1) a duty cycle of 3 ms on and 5 ms off; and (2) a cycle of 3 ms on and 45 ms off. Control surfaces were unmodified polysiloxane, activated polysiloxane via flaming, and flamed polysiloxane further modified with poly-D-lysine (PDL). The different surfaces were characterized with XPS analysis, water contact angle, and cell adhesion and growth using dissociated murine embryonic spinal tissue. We found that both the amine content of the 3/45 duty cycle surface and the wettability was higher than that of the 3/5 surface. Also, spinal cord cells were better dispersed 24 h after seeding on the 3/45 surface, suggesting a difference in early adhesion dynamics. However, the networks on the two types of modified surfaces revealed no obvious morphological differences after 2 weeks in vitro. The stability of allylamine-decorated surfaces after autoclaving was high with only minor changes in wettability and nitrogen content. Cell growth on such surfaces after autoclaving was comparable to that found on flamed polysiloxane, freshly modified with PDL. Allylamine surfaces were still usable as cell growth substrates after three autoclaving cycles, 4 weeks under warm culture medium, and simple cleaning procedures, indicating the achievement of a long-lasting modification that did not require the repeated use of PDL before each seeding.

Potential use of ipatropium bromide for the treatment of clozapine-induced hypersalivation: a preliminary report

Sialorrhea is reported by 31% of patients taking clozapine. Anticholinergic agents and adrenergic agonists are used for its treatment based on empirical evidence. In the present study, 10 patients who failed to respond to anticholinergic or adrenergic agents received intranasal ipatropium bromide (IPB) to minimize anticholinergic systemic absorption. Intranasal IPB was given to 10 patients for clozapine-induced sialorrhea who failed to respond to benztropine or clonidine. Pre-, post- and 6 month follow-up values were recorded on a single-item, 5-point Hypersalivation Rating Scale. The sign test was used for statistical comparison (P < 0.05). Eight patient reported initial improvement in sialorrhea values. Two patients reported no change and two patients discontinued IPB. At 6 months, six patients maintained improvement. Side-effects for IPB were minor. A significant trend was observed in the values pre- and post-treatment with IPB (P < 0.004). Improvement was maintained at 6 month follow-up (P < 0.008). This case series demonstrates the possible utility of intranasal IPB for clozapine-induced sialorrhea. Intranasal IPB lacks significant systemic anticholinergic effects when prescribed along with clozapine. This study shows only qualitative differences in salivation values and large controlled-comparative trials are needed.

First Report of Golden Dwarf Mistletoe on Pinus maximinoi

Golden dwarf mistletoe (Arceuthobium aureum subsp. aureum Hawksw. & Wiens) is endemic to east-central Guatemala (Departments Alta Verapaz, Baja Verapaz, and Quiche) (1,2). Its principal hosts are Pinus pseudostrobus Lindl., P. montezumae Lamb., and P. oaxacana Mirov (1). In May 1999, A. aureum subsp. aureum was observed infecting Pinus maximinoi H. E. Moore at four locations: 1.0 km south (altitude 1,580 m) and 5.4 km north (altitude >1,630 m) of La Cumbre, Baja Verapaz on Route CA-14, 8 km west (altitude 1,670 m) of Chilasco, Baja Verapaz, and 5 km west (altitude 1,490 m) of San Cristobal Verapaz, Alta Verapaz on Route 7-W. Although previous reports (1,2) indicated that golden dwarf mistletoe does not induce witches'-brooms on its hosts, older (>50 years), severely affected P. maximinoi were observed to have formed large witches'-brooms as a result of dwarf mistletoe infection. Although it has been suggested that Pinus oocarpa Schiede is susceptible to golden dwarf mistletoe (1), several large trees of this species were observed growing within 5 m of infected P. maximinoi at three of the four locations, but none were infected. This is the first report of golden dwarf mistletoe on P. maximinoi. References: (1) F. G. Hawksworth and D. Wiens. 1996. Dwarf Mistletoes: Biology, Pathology, and Systematics. USDA Agric. Handb. 709. (2) D. Wiens and C. G. Shaw, J. Idaho Acad. Sci. 30:25, 1994.

Vibrios associated with Litopenaeus vannamei larvae, postlarvae, broodstock, and hatchery probionts

Several bacteriological surveys were performed from 1994 to 1996 at different Litopenaeus vannamei hatcheries (in Ecuador) and shrimp farms (in Mexico). Samples were taken from routine productions of healthy and diseased L. vannamei larvae, postlarvae, and their culture environment and from healthy and diseased juveniles and broodstock. In Ecuador, the dominant bacterial flora associated with shrimp larvae showing symptoms of zoea 2 syndrome, mysis mold syndrome, and bolitas syndrome has been determined. Strains were characterized by Biolog metabolic fingerprinting and identified by comparison to a database of 850 Vibrio type and reference strains. A selection of strains was further genotypically fine typed by AFLP. Vibrio alginolyticus is predominantly present in all larval stages and is associated with healthy nauplius and zoea stages. AFLP genetic fingerprinting shows high genetic heterogeneity among V. alginolyticus strains, and the results suggest that putative probiotic and pathogenic strains each have specific genotypes. V. alginolyticus was found to be associated with larvae with the zoea 2 syndrome and the mysis mold syndrome, while different Vibrio species (V. alginolyticus and V. harveyi) are associated with the bolitas syndrome. V. harveyi is associated with diseased postlarvae, juveniles, and broodstock. The identities of the strains identified as V. harveyi by the Biolog system could not be unambiguously confirmed by AFLP genomic fingerprinting. Vibrio strain STD3-988 and one unidentified strain (STD3-959) are suspected pathogens of only juvenile and adult stages. V. parahaemolyticus, Photobacterium damselae, and V. mimicus are associated with juvenile and adult stages.

The behaviour of titanium as a biomaterial: microscopy study of plates and surrounding tissues in facial osteosynthesis

Titanium has become the biomaterial of choice for facial osteosynthesis. Titanium is considered a highly biocompatible and corrosion resistant material, although the ultrastructural behaviour of titanium in human tissues after bone fixation is not well documented. A prospective scanning electron microscopy study was carried out on 37 commercially pure titanium miniplates which were removed from 23 patients who had undergone surgery for maxillofacial trauma or deformity. Twenty two cases were used as a control group. Implant-bone specimens were excised using tungsten burs and studied with a scanning electron microscope (Jeol JSM-T-300). Findings at the bone-titanium interface were analyzed, as well as the presence of contaminating bodies on the specimen surface. Biopsies were also obtained from the soft tissues adjacent to 20 miniplates, then sectioned and stained with Haematoxilin-Eosin for histological evaluation by light microscopy. The results showed good ultrastructural osseointegration of the osteosynthesis material in most cases (81.8%). Mobility was found upon removal in 80% of plates which showed clinical complications. A significant correlation was found between the degree of microscopical osseointegration and macroscopic fixation of the plate. Microscopical contamination was found in 100% of the nine plates with intraoral exposure, while only 36% of the 22 miniplates of the control group had contaminating elements (P < 0.001). Thirty-five point one percent of the plates showed hole-like substance loss images, whose size ranged from 10-25 mu. Light microscopy showed granular deposits in soft tissues surrounding the plates in 80% of the 20 specimens investigated. Our findings suggest a higher development of corrosion in titanium than previously reported. These findings are not correlated, however with the clinical complications.

Identification of one tachykinin- and two kinin-related peptides in the brain of the white shrimp, Penaeus vannamei

This paper reports the purification of three myotropic neuropeptides from the white shrimp Penaeus vannamei. The central nervous systems of 3500 shrimps were extracted in an acidified solvent, after which four to five HPLC column systems were used to obtain pure peptides. A cockroach hindgut muscle contraction bioassay was used to monitor all collected fractions. The pure peptides were submitted to Edman degradation based automated microsequencing. Mass spectrometry and chemical synthesis confirmed the sequences. Ala-Pro-Ser-Gly-Phe-Leu-Gly-Met-Arg-NH2 (Pev-tachykinin, 934.1 Da) belongs to the tachykinin family with identified members in all vertebrate classes and some invertebrate classes: arthropods, annelids and molluscs. A very specific Pev-tachykinin antiserum was developed, which labels 4 neurosecretory cells in the brain. Ala-Ser-Phe-Ser-Pro-Trp-Gly-NH2 (Pev-kinin 1, 749.8 Da) and Asp-Phe-Ser-Ala-Trp-Ala-NH2 (Pev-kinin 2, 694.7 Da) are the first crustacean kinins. Pev-kinin 2 is the first kinin with a Trp-Ala-NH2 instead of a kinin-typical Trp-Gly-NH2 carboxyterminus.

Role of neutrophils in innate resistance to Entamoeba histolytica liver infection in mice

In order to define the role of neutrophils in the innate resistance to Entamoeba histolytica liver infection in mice, we examined the pattern of liver lesion induced by direct injection of E. histolytica trophzoites in normal mice and in neutrophil-depleted mice. A variety of histological lesions were found, the extent of liver damage was considerably higher in the neutrophil-depleted mice. Livers from neutrophil-depleted mice displayed areas of liquefactive (lytic) necrosis containing a large number of amoebae and absence of neutrophils or mononuclear cells. By contrast, in the liver of normal mice, neutrophils were seen associated to E. histolytica at early stages of infection. In both mouse groups, areas of TUNEL-positive dead hepatocytes were observed and a characteristic internucleosomal banding pattern of genomic DNA consistent with apoptosis was detected in DNA harvested from amoebic liver lesions. These data suggest that neutrophils play an important role in the mechanisms of resistance to amoebic liver infection in mice. In addition, our histological analysis suggests that E. histolytica is capable of producing liver damage in the absence of inflammatory cells.

Short report: identification of B-cell epitopes in the serine-rich Entamoeba histolytica protein

The serine-rich Entamoeba histolytica protein (SREHP) has been shown to be a protective antigen in animal models of amebic liver abscess when delivered by either parenteral or oral routes of immunization, and antibodies to SREHP can prevent amebic liver abscess in severe combined immunodeficient mice. To identify B cell epitopes of the SREHP molecule that could serve as the basis for a peptide-based vaccine, we synthesized overlapping peptides spanning the amino acid sequence of SREHP, and looked at the reactivity of serum samples from five individuals with amebic liver abscess to the overlapping peptides. We found that most of the epitopes recognized by serum samples from patients with amebic liver abscess map to the hydrophilic dodecapeptide or octapeptide repeats of SREHP, but there was no universal epitope recognized by all five serum samples. In addition, we show that synthetic peptides that include the epitopes of SREHP recognized in the mapping study are immunogenic in animals and can generate antibodies that recognize SREHP.