Invited Article: miniTimeCube

We present the development of the miniTimeCube (mTC), a novel compact neutrino detector. The mTC is a multipurpose detector, aiming to detect not only neutrinos but also fast/thermal neutrons. Potential applications include the counterproliferation of nuclear materials and the investigation of antineutrino short-baseline effects. The mTC is a plastic 0.2% (10)B-doped scintillator (13 cm)(3) cube surrounded by 24 Micro-Channel Plate (MCP) photon detectors, each with an 8 × 8 anode totaling 1536 individual channels/pixels viewing the scintillator. It uses custom-made electronics modules which mount on top of the MCPs, making our detector compact and able to both distinguish different types of events and reject noise in real time. The detector is currently deployed and being tested at the National Institute of Standards and Technology Center for Neutron Research nuclear reactor (20 MWth) in Gaithersburg MD. A shield for further tests is being constructed, and calibration and upgrades are ongoing. The mTC's improved spatiotemporal resolution will allow for determination of incident particle directions beyond previous capabilities.

Prognostic factors in the diagnostic work-up of cancer patients in an internal medicine department: does age matter?

INTRODUCTION

Increasing life expectancy in the general population has led to a rise in the incidence of cancer and new challenges with regard to the diagnosis, therapy and prognosis of this disease.

AIM

To assess prognostic factors in the initial work-up of patients ultimately diagnosed with cancer in an Internal Medicine Service, particularly those related with age.

PATIENTS AND METHODS

A prospective study was undertaken with 224 patients ultimately diagnosed with cancer, as confirmed by histological or cytological study. The neoplasms included respiratory, gastrointestinal, genitourinary, metastatic adenocarcinoma of unknown origin, gynaecological, hepatobiliary and others. Before reaching the diagnosis, the following factors were investigated in all patients: functional status [Karnofsky Performance Status (KPS)], comorbidity (Charlson scale), body mass index (BMI), serum cholesterol and albumin concentrations, cognitive level (Mini-mental test), quality of life (Short Form 36 questionnaire), and extension of the disease according to established criteria. Survival at 1 year was analysed. Statistical analyses were done with spss 11.0 for Windows, using a forward stepwise (likelihood ratio) method to construct the model and a Cox multivariate model for the survival analysis.

RESULTS

A total of 224 patients, 167 men (74.5%) and 57 women (25.5%), with a mean age of 66.1 +/- 12.3 years were studied. KPS was >or= 70 in 84% and comorbidity was zero or one in 74%. BMI was 24.25 +/- 4.3, cholesterol 180.7 +/- 4.3, albumin 3.32 +/- 0.5 and Mini-mental score 25.4 +/- 3.7. Metastasis was seen in 131 patients (58.5%) and local disease in 93 cases (41.5%). One-year survival was 38.8% (87 patients) with a mean of 203.8 +/- 143 days. In the Cox analysis, the independent predictive factors for survival were KPS [hazard ratio (HR) = 0.951; 95% CI = 0.930-0.974; p < 0.01], metastatic dissemination (HR = 2.422; 95% CI = 1.643-3.571; p < 0.01), physical quality of life (HR = 0.978; 95% CI = 0.962-0.995; p < 0.01) and albumin (HR = 0.653; 95% CI = 0.455-0.936; p < 0.01).

CONCLUSIONS

In the initial work-up of patients ultimately diagnosed with cancer in an Internal Medicine Service, functional status, dissemination, the physical component in the quality of life scale and serum albumin levels were independent prognostic factors for survival. Age was not an independent prognostic factor and should not be used as a basis for adopting diagnostic or therapeutic decisions in these patients.

62-kb plasmids harboring rulAB homologues confer UV-tolerance and epiphytic fitness to Pseudomonas syringae pv. syringae mango isolates

The presence of genetic determinants homologous to rulAB genes for ultraviolet (UV) radiation resistance was determined in a collection of Pseudomonas syringae pv. syringae strains isolated from mango. The potential role of these plasmids in UV tolerance and ecological fitness in the mango phyllosphere was also evaluated. Nearly all of the 62-kb plasmids present in the P. syringae pv. syringae strains hybridized with a rulAB probe, but these 62-kb plasmids showed differences in restriction patterns. In vitro assays of tolerance to UV radiation of P. syringae pv. syringae strains showed a higher survival of the strains harboring the 62-kb plasmids compared to strains lacking plasmids when exposed to UVC or UVA+B fractions. Similar results were observed when transconjugants harboring the 62-kb plasmid were tested. Survival assays were carried out under field conditions, and a higher survival of P. syringae pv. syringae strains harboring 62-kb plasmids under direct solar radiation on the adaxial surface of leaves was also observed. When the assays were carried out in shady areas or on the abaxial surface of leaves, survival time was comparable for all the assayed strains, whether or not they contained a 62-kb plasmid hybridizing to rulAB. Our results indicate that P. syringae pv. syringae strains harboring 62-kb plasmids show an increase in ecological fitness when colonizing the mango phyllosphere.

Patterns of the circumflex femoral arteries revisited

Knowledge of variations of the circumflex femoral arteries is important when undertaking clinical procedures within the femoral region and in hip joint replacement. Since the 19th century, many different patterns have been proposed to classify their origins. This work studied a statistically reliable sample, the lower limbs of 221 embalmed human cadavers (equal right-left and approximately equal sex distributions), and reviewed the previous literature to propose a unified and simple classification that will be useful to clinicians. Statistical comparisons were made using the chi(2) test. The medial and lateral circumflex femoral arteries have been classified into three different patterns based on the levels of their origin. Distribution related to sex and side was also studied. Pattern I: Both arteries arose from the deep femoral artery (346 cases, 78.8%). This pattern was more frequent in females, P = 0.01. There was no significant difference between sides. Type Ia, medial circumflex femoral artery origin was proximal to the lateral circumflex femoral artery origin (53.2%); Type Ib, lateral circumflex femoral artery origin was proximal to medial circumflex femoral artery origin (23.4%); Type Ic, both arteries arose from a common trunk (23.4%). Pattern II: One of the arteries arose from the femoral artery and the other from the deep femoral artery (90 cases, 20.5%). Type IIa, the medial circumflex femoral artery arose from the femoral artery (77.8%) and Type IIb, the lateral circumflex femoral artery arose from the femoral artery (22.2%). There were no significant differences between sexes or sides. Pattern III: Both arteries arose from the femoral artery (2 cases, 0.5%). In every disposition there was a significantly higher prevalence of unilateral rather than bilateral occurrence. In one dissection the medial circumflex femoral artery was absent. Awareness of these variations could avoid unexpected injuries.

Femoral nerve entrapment: A new insight

Compression of the femoral nerve in the iliac fossa has been reported as a consequence of several pathologies, but never as a result of muscular compression. Aberrant slips of iliacus, however, have occasionally been reported to cover or split the femoral nerve. This study aimed to assess such variations as potential factors in femoral nerve compression. A large and homogeneous sample of 121 embalmed cadavers (242 specimens) was studied. Statistical comparisons were made using the chi-squared test. Muscular slips from iliacus and psoas, piercing or covering the femoral nerve, were found in 19 specimens (7.9%). No significant differences by sex or side were found. The more frequent variation was piercing of the femoral nerve by a muscular slip (17 specimens, 7.0%). The nerve then entered the thigh as one or more branches. The less frequent variation found was a muscular slip or sheet covering the femoral nerve as it lay on iliacus (2 specimens, 0.8%). Each disposition may be a potential risk for nerve entrapment.

[Expert opinion on the basic surgical technique for laparoscopic ventral hernia repair]

Laparoscopic ventral hernia repair is currently the subject of intense debate, even though it provides a series of advantages over open surgery and is feasible and safe. Various studies have shown this technique to be as effective as open repair with a lower recurrence rate. Despite the excellent results of laparoscopic repair of ventral hernias, there are numerous controversies associated with this procedure. These controversies concern the indications and contraindications of the procedure, and technical aspects such as how to create the pneumoperitoneum, perform adhesiolysis, manage the hernia sac, and insert and fix the mesh to the anterior abdominal wall. Also controversial are outcome, complications related to postoperative seroma, and which type and size of mesh should be used. The present article aims primarily to address many of these issues, based on the experience of distinct surgeons with expertise in this approach, in order to provide data to establish a consensus on how laparoscopic ventral hernia repair should be performed.

Six Races of Venturia inaequalis are Found Causing Apple Scab in Spain

Apple scab, caused by the ascomycete Venturia inaequalis, is an important disease of apple (Malus domestica) worldwide and is generally managed with intensive applications of fungicides or, for specific markets, by planting of resistant cultivars. Currently, eight races of the pathogen have been defined on the basis of their ability to overcome sources of resistance used by plant breeders (2). We undertook the identification of apple scab races present in Spain as a necessary step for the deployment of resistant cultivars. Spore suspensions (2.5 × 10⁵ spores per ml) were prepared from fresh lesions of apple scab collected from apple trees in commercial or domestic orchards located in the northeastern Spanish provinces of Gerona, Guipúzcoa, and Navarra. To identify races 1 to 7, the suspensions were used to inoculate cv. Gala and six differential apple clones with five replicates. Cultivar Gala was used as a universal susceptible control. The differential apple clones included X2250, X2253 (Geneva), X2249, X2225, X2596 (Prima), and X6518 (M. floribunda 821) (1,4). All leaves were assessed on each inoculated shoot 17 days after inoculation, and the type of symptoms were scored using the scale of Chevalier et al. (3). Sporulation was evaluated on seven replicate leaf discs (1 cm in diameter) for each combination of inoculum and plant host (4). All the inocula tested produced typical apple scab symptoms and sporulation (>10⁶ conidia per cm²) on cv. Gala. Races 2, 3, 5, and 6 were identified on the basis of the elicitation of typical disease symptoms with abundant sporulation (>3 × 10⁶ conidia per cm²) on clones X2250, X2253, X2225, and X2596, respectively. Races 2 and 6 were present in inocula from Gerona, Guipúzcoa, and Navarra, whereas races 3 and 5 were identified only in an inoculum from Tudela, Navarra. An inoculum from La Tallada, Gerona, was assigned to race 1 because it produced typical disease symptoms and sporulation only on cv. Gala, while the differential clones were scored as resistant. In Santesteban, Navarra, a monosporic isolate of V. inaequalis, designated VIP28, was obtained in the field from a single lesion in a 2-year-old tree of clone 2.1.1, which is resistant to race 1. VIP28 produced lesions typical of weak virulence in clone X6518 and produced a significant degree of sporulation (0.8 × 10⁶ conidia per cm²), whereas the differential clones for races 2 to 6 were scored as resistant, indicating that this isolate can be classified as race 7 (1). To our knowledge, this is the first report of races of V. inaequalis present in Spain. References: (1) G. Bénaouf and L. Parisi. Phytopathology 90:236, 2000. (2) V. G. M. Bus et al. New Phytol. doi:10.1111/j.1469-8137.2005.01395.x, 2005. (3) M. Chevalier et al. Plant Pathol. 40:249, 1991. (4) L. Parisi et al. Phytopathology 83:533, 1993.

Avascular jaw osteonecrosis in association with cancer chemotherapy: series of 10 cases

BACKGROUND

We present a series of 10 patients with osteonecrosis of the jaws (ONJ) that appeared following cancer chemotherapy.

MATERIAL AND METHODS

Of the 10 cases with ONJ, six had bone metastases from breast cancers and the other four had multiple myeloma. We analysed the location of bone metastases, as well as the characteristics of the ONJ, and the drugs with which they had been treated for their bone metastases.

RESULTS

Of the 10 patients, all had ONJ in the mandible; 50% also had maxillary involvement. The average number of areas of painful exposed was 2.1 per patient (range 1-5). In seven patients a tooth extraction preceded the onset of ONJ. Two patients developed oroantral communications and another a cutaneous fistula to the neck with suppuration. In all the 10 patients the histopatholological diagnosis was of chronic osteomyelitis without evidence of metastatic disease to the jaws. All the patients had received treatment for their malignant bone disease with bisphosphonates. These were the only drugs that all patients had received.

CONCLUSION

ONJ appears to have a relationship with the use of bisphosphonates.

Genetic characterization of Erwinia amylovora strains by amplified fragment length polymorphism

AIMS

Erwinia amylovora is one of the most important pathogens of pear and apple and is subject to strict quarantine regulations worldwide, although its patterns of dispersal are largely unknown. Previous attempts to fingerprint E. amylovora strains by molecular techniques have detected very little polymorphism because of the high genetic homogeneity of this bacterium. Our aim was to establish and test a typing method to quantify genetic diversity among strains of this plant pathogen.

METHODS AND RESULTS

Twenty-two strains from different hosts and geographical locations were examined by PCR fingerprinting with four primers and by amplified fragment length polymorphism (AFLP) with four selected combinations of primers with a single base extension. PCR fingerprinting revealed little polymorphism producing the same amplification patterns for 17 strains, while the combined AFLP patterns yielded 78 polymorphic bands (34% of total bands) and allowed the differentiation of all but two strains. Clustering of strains in the resulting dendrogram was not correlated with host, year or country of isolation, and questions previous genealogies based on PFGE patterns.

CONCLUSIONS

The AFLP technique allowed the detection of an unprecedented number of genetic markers in E. amylovora and proved to be the most useful tool so far for discriminating among strains of this pathogen. The results obtained in this study strongly suggest the occurrence of multiple introductions of the pathogen in Spain and other European countries.

SIGNIFICANCE AND IMPACT OF THE STUDY

A major limitation in understanding the ecology of fire blight is the lack of typing techniques with a high power of discrimination. This study demonstrates the high resolution and the usefulness of the AFLP technique to differentiate among E. amylovora strains.

[Surgical treatment of haemangiomas]

The therapeutic approach to haemangiomas has changed slightly in recent years, moving from a generally conservative attitude to a more aggressive one in some cases. Chronic unaesthetic alterations that might be caused by haemangiomas, psychosocial traumas that can be caused during childhood, together with a better understanding of the behaviour of this type of lesions and advances in safer and more efficient surgical techniques are the basic factors behind this change of attitude. The present paper concentrates on the surgical treatment of haemangiomas, explaining their indications according to the stage of evolution at which they are found, and the surgical techniques employed to resect the lesion with the least morbidity. Similarly, a detailed treatment is given to those lesions that, because of their specific facial anatomical localization, require a special surgical treatment.

Vaginal Reconstruction Using a Modified Rectus Abdominis Musculocutaneous Flap in Pelvic Cancer Surgery

The authors present a modification of the design for the classic cutaneous pattern of the rectus abdominis musculocutaneous flap for vaginal reconstruction after pelvic cancer surgery. The authors designed a paramedial and supraumbilical dermo-cutaneous flap with paraumbilical randomized vascularization, which was sutured to the classic cutaneous TRAM flap pattern and rotated around a longitudinal axis to form the neo-introitus. The use of this new cutaneous design allows for a perfect cylindrical shape all along the length of the new vagina, thus achieving a more anatomic reconstruction than those currently obtained with the classic cutaneous patterns, and with fewer tendencies to distal retraction, necrosis, and partial stenosis.

[Thoracic metastasis of breast carcinoma. Current status]

Breast cancer is a common pathology. It is clinically considered as a localized or regionally developing illness at the time of diagnosis, but the appearance of metastases is a frequent complication. Patients are commonly referred with local or regional recurrence of the disease. Invasive metastatic disease found in the chest can be differentiated according to area as follows: pulmonary parenchyma (nodes and/or carcinomatosis lymphangitis), pleural cavity (pleural effusion and/or tumor), pericardial effusion and the thoracic wall. The appearance of pulmonary parenchymal metastases secondary to breast cancer can be further categorized into three types, neoplastic lymphangitis, multiple and single pulmonary nodes. Pleural effusion is the commonest thoracic affection in patients with this pathology. It is accepted that 46% of patients with disseminating breast cancers will develop pleural metastases where the presentation is pericardial effusion, and possible cardiac tamponade. Finally, metastatic disease may be found localized to within the thoracic wall. Breast cancer can produce diverse problems in the thoracic wall, and local recurrence is most frequent at the mastectomy site.

The effect of two different doses of aprotinin on hemostasis in cardiopulmonary bypass surgery: similar transfusion requirements and blood loss

BACKGROUND AND OBJECTIVES

Various dosages of aprotinin have proven to be effective in reducing blood loss and allogeneic transfusion requirements in cardiopulmonary bypass surgery, despite the controversy surrounding the precise hemostatic mechanisms of this drug. The aim of our prospective, randomized, double-blind study was to assess differences in blood loss and transfusion requirements and the effect of two dosages of aprotinin on hemostatic activation.

DESIGN AND METHODS

Patients undergoing coronary artery bypass grafting received high-dose aprotinin (n=28), pump-prime-only (PPO) aprotinin (n=28), or placebo (n=28).

RESULTS

The high-dose and the PPO groups had a significantly lower blood loss (985 mL [95%CI 845-1,102] and 1,255 mL, [95% CI 1,025-1,406], respectively) than the placebo group (1,416 mL, 95%CI 1,248-1,612]. Transfusion requirements were lower in the aprotinin-treated groups than in the patients receiving placebo (21 units and 15 units in the high and low-dose groups vs 59 units in placebo group). As far as concerns parameters of thrombin generation, the aprotinin groups showed a significant reduction of F1+2 prothrombin fragment but not of thrombin-antithrombin complexes. There were higher levels of natural anticoagulants, i.e. antithrombin, protein C and protein S, in the high-dose aprotinin group. As regards fibrinolysis parameters, D-dimer was lower in the aprotinin groups, and the levels of alpha2-antiplasmin and plasmin-alpha2-antiplasmin complexes were raised. In summary, both dosages of aprotinin were equally effective in reducing blood loss and transfusion requirements. There was a lower activation of coagulation and fibrinolysis in cardiopulmonary bypass patients treated with aprotinin: the levels of natural anticoagulants were less decreased in the high-dose group. No differences in thrombotic complications were observed between aprotinin groups.

INTERPRETATION AND CONCLUSIONS

Our study shows that both dosages of aprotinin are safe and effective in reducing transfusion requirements. Considering the difference in cost of using a low-dose or high-dose schedule, the former should be recommended for patients undergoing cardiopulmonary bypass surgery.

Sequence diversity of rulA among natural isolates of Pseudomonas syringae and effect on function of rulAB-mediated UV radiation tolerance

The rulAB locus confers tolerance to UV radiation and is borne on plasmids of the pPT23A family in Pseudomonas syringae. We sequenced 14 rulA alleles from P. syringae strains representing seven pathovars and found sequence differences of 1 to 12% within pathovar syringae, and up to 15% differences between pathovars. Since the sequence variation within rulA was similar to that of P. syringae chromosomal alleles, we hypothesized that rulAB has evolved over a long time period in P. syringae. A phylogenetic analysis of the deduced amino acid sequences of rulA resulted in seven clusters. Strains from the same plant host grouped together in three cases; however, strains from different pathovars grouped together in two cases. In particular, the rulA alleles from P. syringae pv. lachrymans and P. syringae pv. pisi were grouped but were clearly distinct from the other sequenced alleles, suggesting the possibility of a recent interpathovar transfer. We constructed chimeric rulAB expression clones and found that the observed sequence differences resulted in significant differences in UV (wavelength) radiation sensitivity. Our results suggest that specific amino acid changes in RulA could alter UV radiation tolerance and the competitiveness of the P. syringae host in the phyllosphere.

Skin and wound infection by rapidly growing mycobacteria: an unexpected complication of liposuction and liposculpture. The Venezuelan Collaborative Infectious and Tropical Diseases Study Group

OBJECTIVE

To describe 10 patients with skin and soft tissue infection caused by rapidly growing mycobacteria after cosmetic liposuction and liposculpture.

DESIGN

Case series.

SETTINGS

Eight private geographically separate surgical facilities from a single metropolitan area.

PATIENTS

Eight patients with definite and 2 with presumptive cases of skin and soft tissue infection caused by rapidly growing mycobacteria after cosmetic surgery procedures during a 24-month period. Microorganisms were isolated from the purulent drainage obtained from wounds or fistulas in 8 cases and were identified as Mycobacterium fortuitum (3 cases) and Mycobacterium abscessus (5 cases) by routine microbiologic techniques. Acid-fast bacilli were observed on Ziehl-Neelsen-stained smears in the 2 remaining cases, but these ultimately failed to grow. In 2 of the surgical units, no apparent environmental predisposing factors were identified after thorough microbiologic environmental investigation. Clinically, all patients exhibited signs of inflammation, microabscesses, and purulent wound drainage within 24 months of abdominal and/or thigh liposuction or homologous fat tissue injection.

INTERVENTION

A combined therapeutic approach including surgical drainage, debridment, and prolonged (>3 months) treatment with combined antimicrobial agents including clarithromycin was used in all cases.

RESULTS

Nine of 10 patients responded to the combined therapeutic approach, and no evidence of infection was present during at least 12 months of follow-up.

CONCLUSION

To our knowledge, this is the first series of patients with rapidly growing mycobacterial infections to be described after liposuction and liposculpture. Rapidly growing mycobacteria should be included in the differential diagnosis of skin and soft tissue infection after cosmetic surgery.

Excision from tRNA genes of a large chromosomal region, carrying avrPphB, associated with race change in the bean pathogen, Pseudomonas syringae pv. phaseolicola

Pseudomonas syringae pv. phaseolicola (Pph) race 4 strain 1302A carries avirulence gene avrPphB. Strain RJ3, a sectoral variant from a 1302A culture, exhibited an extended host range in cultivars of bean and soybean resulting from the absence of avrPphB from the RJ3 chromosome. Complementation of RJ3 with avrPphB restored the race 4 phenotype. Both strains showed similar in planta growth in susceptible bean cultivars. Analysis of RJ3 indicated loss of > 40 kb of DNA surrounding avrPphB. Collinearity of the two genomes was determined for the left and right junctions of the deleted avrPphB region; the left junction is approximately 19 kb and the right junction > 20 kb from avrPphB in 1302A. Sequencing revealed that the region containing avrPphB was inserted into a tRNALYS gene, which was re-formed at the right junction in strain 1302A. A putative lysine tRNA pseudogene (PsitRNALYS) was found at the left junction of the insertion. All tRNA genes were in identical orientation in the chromosome. Genes near the left junction exhibited predicted protein homologies with gene products associated with a virulence locus of the periodontal pathogen Actinobacillus actinomycetemcomitans. Specific oligonucleotide primers that differentiate 1302A from RJ3 were designed and used to demonstrate that avrPphB was located in different regions of the chromosome in other strains of Pph. Deletion of a large region of the chromosome containing an avirulence gene represents a new route to race change in Pph.

Cultivar-specific avirulence and virulence functions assigned to avrPphF in Pseudomonas syringae pv. phaseolicola, the cause of bean halo-blight disease

The avrPphF gene was cloned from Pseudomonas syringae pathovar phaseolicola (PPH:) races 5 and 7, based on its ability to confer avirulence towards bean cultivars carrying the R1 gene for halo-blight resistance, such as Red Mexican. avrPphF comprised two open reading frames, which were both required for function, and was located on a 154 kb plasmid (pAV511) in PPH: Strain RW60 of PPH:, lacking pAV511, displayed a loss in virulence to a range of previously susceptible cultivars such as Tendergreen and Canadian Wonder. In Tendergreen virulence was restored to RW60 by avrPphF alone, whereas subcloned avrPphF in the absence of pAV511 greatly accelerated the hypersensitive resistance reaction caused by RW60 in Canadian Wonder. A second gene from pAV511, avrPphC, which controls avirulence to soybean, was found to block the activity of avrPphF in Canadian Wonder, but not in Red Mexican. avrPphF also conferred virulence in soybean. The multiple functions of avrPphF illustrate how effector proteins from plant pathogens have evolved to be recognized by R gene products and, therefore, be classified as encoded by avirulence genes.

Platelet function during cardiopulmonary bypass not changed by two different doses of aprotinin

BACKGROUND AND OBJECTIVE

Bleeding is one of the major complications of cardiopulmonary bypass (CBP) during cardiac surgery. A platelet function defect seems to be the main cause of the hemostatic problems associated with CBP. Controversial results have been reported concerning the possible protective mechanism of action of aprotinin on platelets.

DESIGN AND METHODS

In this study we investigated the effect of two different dosages of aprotinin (high and pump-prime-only dose) on platelet reactivity in vitro and adhesion, activation and aggregation receptors on the platelet surface.

RESULTS

The results obtained from 53 patients undergoing CBP showed a significantly deficient platelet aggregation in response to agonist in all groups without differences between aprotinin treated or not treated patients. No changes in platelet surface expression of glycoprotein (GP) IIb-IIIa, GPIb, GPIV and P-selectin, were observed during CBP between patients treated with aprotinin or not.

INTERPRETATION AND CONCLUSIONS

These data suggest that inadequate platelet function induced by CBP is not a defect intrinsic to the platelet. We conclude that the hemostatic effect of aprotinin, regardless of the dose employed, is not mediated by protection of platelet function.

AIDS in Latin America

The epidemic in Latin America has placed an unexpected additional burden on the health care systems and national economies, already weak and affected by severe problems. Specific regional diseases in addition to common opportunistic infections, and particularly the high incidence of TB, produce a different picture compared with the United States and Europe. Access to ARV therapy is far from being universal in Latin America; nevertheless, some countries are providing HAART to all eligible patients, showing that it is not impossible to improve quality of care for people living with HIV infection in the region. Before assuming as definitive and irreversible that at least one or two generations will be sacrificed on the altar of inequity of our uneven world, we as acting scientists should join the struggle of millions of human beings claiming their right to be treated with the best drugs that science can offer today.

Diagnostic efficiency of serum IGF-I, IGF-binding protein-3 (IGFBP-3), IGF-I/IGFBP-3 molar ratio and urinary GH measurements in the diagnosis of adult GH deficiency: importance of an appropriate reference population

OBJECTIVE

To analyse the diagnostic role of serum IGF-I, IGF-binding protein-3 (IGFBP-3), IGF-I/IGFBP-3 molar ratio and urinary GH (uGH) excretion in adult GH deficiency (GHD).

DESIGN

Twenty-seven adults (age range: 18-71 years) with severe GHD, defined by a peak GH response to an insulin tolerance test below 3microg/l in patients with at least one additional pituitary hypofunction. Reference values were established from a selected age- and body mass index-matched population (154 healthy adults grouped in four age groups).

METHODS

IGF-I and IGFBP-3 were measured by RIA (Nichols) and results expressed as standard deviation (s.d.) scores from our reference population and assay normative data (s.d. score Nichols). uGH was measured by IRMA.

RESULTS

Within the control group, IGF-I, IGFBP-3, IGF-I/IGFBP-3 ratio standardisation regarding our control population and IGF-I with respect to the assay normative data resulted in disappearance of age-related differences. However, IGFBP-3 s.d. score Nichols resulted in mean values between +1.4 and +2.5 s.d. score. Greatest diagnostic efficiency was for IGF-I standardised with respect to our controls (97.2%), followed by s.d. score IGFBP-3 (92.9%). s.d. score IGF/IGFBP-3 ratio and uGH showed poor diagnostic efficiency. Any combination of at least two abnormal parameters raised specificity to 100%. IGF-I standardised with respect to assay reference (s.d. score Nichols) showed similar diagnostic value (95.0%) whereas IGFBP-3 showed low sensitivity (33. 3%). Within the GHD patients, those with three or more additional deficiencies had lower s.d. score IGF-I than those with only two or one.

CONCLUSION

We underline the importance of an appropriate reference population for correct interpretation of GH secretion markers. Considering our results, specificity obtained with two simultaneous abnormal parameters when referred to an adequate reference population may add valuable information to alternative GH stimulation tests to confirm adult GHD.

Effect of short-term aspirin use on C-reactive protein

Markers of inflammation, such as C-reactive protein (CRP) and fibrinogen, have been shown to be predictive of cardiovascular disease. In the Physicians Health Study, the magnitude of reduction in the risk of myocardial infarction with aspirin therapy was related to baseline CRP levels, raising the possibility that the protective effect of aspirin may be due to antiinflammatory properties in addition to its antiplatelet effect. We therefore investigated whether aspirin therapy lowers CRP levels. Because heavy physical exertion is a well-known trigger of myocardial infarction, we also investigated the effect of aspirin on CRP levels before and after strenuous exercise. Thirty-two healthy men, aged 29 +/- 6 years, were enrolled in a randomized, double-blind, parallel study. Blood samples were obtained immediately before and after maximal treadmill exercise at baseline and following 7 days of aspirin therapy (81 or 325 mg). The levels of CRP, as measured by ELISA, increased by 13% following exercise (P < 0.0001). However, aspirin did not significantly alter CRP levels, either at rest (0.81 +/- 0.13 mg/L before aspirin vs. 0.78 +/- 0.13 mg/L on aspirin) or following exercise (0.92 +/- 0.13 mg/L before aspirin vs. 0.86 +/- 0. 13 mg/L on aspirin), P = 0.73. When the resting and postexercise data were combined, the levels were 0.87 +/- 0.13 mg/L before aspirin and 0.82 +/- 0.13 mg/L on aspirin (a nonsignificant 6% reduction, P = 0.20). In conclusion, in healthy male subjects CRP levels were not significantly reduced by short-term aspirin therapy. Our data, taking together with other reports, suggest that aspirin may not affect the levels of inflammatory markers. However, further studies are needed with a longer duration of therapy, among subjects with coronary heart disease, and using additional markers of inflammation besides CRP to determine the long-term effects of aspirin use.

Upright posture and maximal exercise increase platelet aggregability and prostacyclin production in healthy male subjects

BACKGROUND

It is well accepted that heavy physical exertion can trigger the onset of myocardial infarction, but the mechanism is uncertain. As platelet and endothelial function play an important role in thrombotic events, platelet and prostacyclin responses to maximal treadmill exercise were studied.

METHODS/RESULTS

The study subjects were 40 healthy men, mean (SEM) age 29 (5) years. Platelet aggregation was measured on a four channel aggregometer. Plasma 6-keto-prostaglandin F1alpha was analysed using an enzyme immunoassay technique. Upright posture and exercise produced an increase in platelet aggregability, as indicated by a fall in the threshold concentration of adrenaline (epinephrine) from 7.6 (1.5) microM at rest to 4.3 (1.0) microM after exercise (p = 0.002). The collagen lag time became significantly shorter with exercise (from 79.1 (3.1) seconds at rest to 71.9 (2.6) seconds after exercise, p = 0.003). Exercise was also associated with a 55% increase in plasma 6-keto-prostaglandin F1alpha (from 38.1 (75%CI 29.0 to 46.5) pg/ml at rest to 59.2 (47.3 to 66.8) pg/ml after exercise, p<0.001).

CONCLUSIONS

In healthy male subjects, upright posture and maximal exercise increased platelet aggregability but this increase was counteracted by an increase in prostacyclin production. In patients with endothelial dysfunction, a reduced prostacyclin response to exercise may promote a transient prothrombotic imbalance that may trigger cardiovascular disease onset.

Identification of a pathogenicity island, which contains genes for virulence and avirulence, on a large native plasmid in the bean pathogen Pseudomonas syringae pathovar phaseolicola

The 154-kb plasmid was cured from race 7 strain 1449B of the phytopathogen Pseudomonas syringae pv. phaseolicola (Pph). Cured strains lost virulence toward bean, causing the hypersensitive reaction in previously susceptible cultivars. Restoration of virulence was achieved by complementation with cosmid clones spanning a 30-kb region of the plasmid that contained previously identified avirulence (avr) genes avrD, avrPphC, and avrPphF. Single transposon insertions at multiple sites (including one located in avrPphF) abolished restoration of virulence by genomic clones. Sequencing 11 kb of the complementing region identified three potential virulence (vir) genes that were predicted to encode hydrophilic proteins and shared the hrp-box promoter motif indicating regulation by HrpL. One gene achieved partial restoration of virulence when cloned on its own and therefore was designated virPphA as the first (A) gene from Pph to be identified for virulence function. In soybean, virPphA acted as an avr gene controlling expression of a rapid cultivar-specific hypersensitive reaction. Sequencing also revealed the presence of homologs of the insertion sequence IS100 from Yersinia and transposase Tn501 from P. aeruginosa. The proximity of several avr and vir genes together with mobile elements, as well as G+C content significantly lower than that expected for P. syringae, indicates that we have located a plasmid-borne pathogenicity island equivalent to those found in mammalian pathogens.

Ocular linguatuliasis in Ecuador: case report and morphometric study of the larva of Linguatula serrata

Linguatula serrata is a pentastomid, a cosmopolitan parasite belonging to the Phylum Pentastomida. Humans may act as an intermediate or accidental definitive host of this parasite, manifesting the nasopharyngeal or visceral form, with the latter having been described more frequently. The occurrence of ocular linguatuliasis is extremely rare, but it has been reported in the United States and Israel. The objective of the present paper was to report the first case of ocular linguatuliasis in Ecuador and to extend the morphologic study of L. serrata by morphometric analysis. The patient studied was a 34-year old woman from Guayaquil, Ecuador who complained of ocular pain with conjunctivitis and visual difficulties of two-months duration. Biomicroscopic examination revealed a mobile body in the anterior chamber of the eye. The mobile body was surgically removed. The specimen was fixed in alcohol, cleared using the technique of Loos, stained with acetic carmine, and mounted on balsam between a slide and a coverslip. It was observed with stereoscopic and common light microscopes in combination with an automatic system for image analysis and processing. The morphologic and morphometric characteristics corresponded to the third-instar larval form of L. serrata. To our knowledge, ocular linguatuliasis has not been previously described in South America, with this being the first report for Ecuador and South America. The present study shows that computer morphometry can adequately contribute both to the morphologic study and to the systematic classification of Pentastomids, and L. serrata in particular.

Functional analysis of the Pseudomonas syringae rulAB determinant in tolerance to ultraviolet B (290-320 nm) radiation and distribution of rulAB among P. syringae pathovars

The effect of the plasmid-encoded rulAB (resistance to ultraviolet radiation) determinant on responses of Pseudomonas syringae to ultraviolet-B (UV-B) radiation and the distribution of rulAB among pathovars of P. syringae were determined. The cloned rulAB determinant and the native rulAB+ plasmid pPSR1 both conferred approximately a 10-fold increase in survival on P. syringae pv. syringae FF5 following increasing doses of UV-B radiation. rulAB+ P. syringae strains also maintained significantly larger epiphytic populations on leaf surfaces irradiated with UV-B. rulAB-insertional mutants, constructed in two native rulAB+ strains, were from 10- to 100-fold more sensitive to UV-B radiation. The UV tolerance phenotype and the rulAB genes were widely distributed among P. syringae pathovars isolated from varied plant hosts throughout the world and within a broad range of genotypic backgrounds of P. syringae pv. syringae. With one exception, the rulAB determinant was harboured on pPT23A-like plasmids; these replicons are indigenous residents of the species P. syringae and also tend to encode determinants of importance in host-pathogen interactions.

Environmental distribution and diversity of Bacillus thuringiensis in Spain

Bacillus thuringiensis was isolated from 301 out of 1,005 samples collected in Spain from agricultural and non-cultivated soils, dust from stored products, and dead insects. Based on the production of parasporal crystals, 1,401 isolates were identified as B. thuringiensis after examining 11,982 B. thuringiensis-like colonies. We found a greater presence of B. thuringiensis in dust from grain storages than in other habitats. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis of the spore-crystal mixtures revealed diverse populations of B. thuringiensis which were differentiated in at least 92 distinct protein profiles. Serological identification also showed great diversity among the Spanish isolates which were distributed among 38 of the 58 known serovars. The most frequently found serovars were aizawai, kurstaki, konkukian, morrisoni, and thuringiensis, which together represented more than 50% of the serotyped isolates. In preliminary toxicity assays, a number of isolates were found to show significant insecticidal activity against the lepidopterans Heliothis armigera (76.1% of the assayed isolates), Spodoptera exigua (50.5%), and Plutella xylostella (19.7%). Thirty five isolates were toxic to both H. armigera and S. exigua, and eight were toxic to S. exigua and P. xylostella. Four and one isolates were toxic to the coleopterans Leptinotarsa decemlineata and Colaspidema atrum, respectively, and three to the dipteran Tipula oleracea. The electrophoretic pattern and serovar of most of the isolates with toxic activity were consistent with those reported in the literature, although other isolates revealed unusual protein profiles, were assigned to new H serovars, or were included in H serovars not previously reported within such pathotypes.

Effect of aspirin dosage and enteric coating on platelet reactivity

Although aspirin is effective in the prevention and treatment of cardiovascular diseases, the optimal dose remains uncertain. The purpose of this study was to compare the platelet inhibitory and prostacyclin-sparing effects of 2 doses (81 and 325 mg) and forms (enteric-coated and regular) of aspirin. Since platelet reactivity has been reported to increase after strenuous exercise, a known trigger of myocardial infarction, subjects were studied following maximal treadmill exercise as well as at rest. Forty male healthy subjects were evaluated using a randomized, double-blind, parallel study design. Blood samples were obtained before and after maximal treadmill exercise at baseline and after 7 days on aspirin therapy. Both enteric and regular aspirin in 81- and 325-mg dosages markedly inhibited adenosine diphosphate and epinephrine-induced aggregation at rest and after exercise. Aspirin also inhibited the platelet response to collagen as assessed by a longer lag time to aggregation. The prolongation of lag time was greater for 325 mg than for 81 mg (100 +/- 7 vs 91 +/- 7; p = 0.04, after exercise). There were no significant dose-related differences in plasma 6-keto-prostaglandin F1alpha level; however, enteric-coated aspirin inhibited the exercise-induced increase in 6-keto-prostaglandin F1alpha to a lesser extent than regular aspirin. Although both doses (81 and 325 mg) and types (regular and enteric-coated) of aspirin inhibited adenosine diphosphate and epinephrine-induced aggregation equally, the 325-mg dose inhibited collagen-induced aggregation to a greater extent than 81 mg. The greater platelet inhibition observed with 325 mg may be clinically relevant in acute coronary syndromes characterized by plaque rupture with extensive collagen exposure and platelet activation.

Avirulence gene avrPphC from Pseudomonas syringae pv. phaseolicola 3121: a plasmid-borne homologue of avrC closely linked to an avrD allele

Cosmid clone pPsp01 from race 1 Pseudomonas syringae pv. phaseolicola isolate 3121 conferred a unique pattern of soybean cultivar reactions when expressed in P. s. pv. glycinea R4. The avirulence phenotype was shown to result from the presence in clone pPsp01 of an avrD allele as well as an additional avirulence gene located approximately 5-kb upstream. The new gene, called avrPphC, shows high identity to and is phenotypically identical to avrC, previously cloned from P. s. pv. glycinea race 0. avrD and avrPphC occur on an approximately 120-kb indigenous plasmid in P. s. pv. phaseolicola 3121. Although commonly observed in Xanthomonas campestris, this is the first noted occurrence of multiple avirulence genes on a single plasmid in Pseudomonas syringae. Unlike avrD, however, avrPphC does not appear to occur widely in pathovars of Pseudomonas syringae.

Two native plasmids of Pseudomonas syringae pathovar tomato strain PT23 share a large amount of repeated DNA, including replication sequences

Strain PT23 of Pseudomonas syringae pv. tomato contains four native plasmids, designated A, B, C, and D. By DNA hybridization of genomic and plasmid DNA digests from the wild type and a plasmid-cured strain, we determined that c. 61 kb (c. 74%) of pPT23B is repeated in pPT23 A and only c. 17 kb (c. 21%) is in single copy in strain PT23. pPT23B also contains DNA repeated in the chromosome that occurs in three DNA fragments of 0.6, 4.6, and 9.6 kb that might be transposable elements. Additionally, the 9.6 kb fragment also shares sequences with the three other plasmids of strain PT23. By DNA hybridization with the origin of replication from a native plasmid of P. syringae pv. syringae and in vivo replication tests, we identified the origins of replication of plasmids A, B, and D and showed that they cross-hybridize. The putative par region from pPT23 A has also been identified and is not conserved in the other three native plasmids from strain PT23. By using the defined minimal origin of replication from pPT23 A as a probe, we showed that it is highly conserved in 14 strains belonging to nine different pathovars of P. syringae and that as many as five different native plasmids with closely related origins of replication coexist in the same cell. The duplication and reorganization of plasmids might therefore occur at high frequency and could be responsible for the existence of large numbers of native plasmids in P. syringae strains.

Characterization of pPT23B, the plasmid involved in syringolide production by Pseudomonas syringae pv. tomato PT23

Avirulence gene D (avrD) in strain PT23 of Pseudomonas syringae pv. tomato (Pst) specifies the production of syringolides, which are elicitors of plant defense reactions. An 83-kb indigenous plasmid (pPT23B) that carries avrD has been mapped and characterized and a putative par region was identified. pPT23B contains a large amount of DNA that is repeated in other native plasmids in PT23. A putative mobile insertion element that occurs on plasmid pPT23A as well as on the chromosome was also identified in strain PT23. New broad-host-range expression vectors that functioned in Pst were constructed for overexpression of the cloned avrD gene and high-level production of the syringolides. Introduction of an avrD overexpression plasmid into PT23 or plasmid-cured strains led to identical syringolide peaks on HPLC with no new peaks observed. These results suggested that neither pPT23B nor other indigenous plasmids in Pst carry additional genes required for syringolide production or metabolism. Pst strains lacking pPT23B were not impaired in virulence on tomato plants.