First Report of "Candidatus Liberibacter psyllaurous" or "Ca. Liberibacter solanacearum" Associated with Severe Foliar Chlorosis, Curling, and Necrosis and Tuber Discoloration of Potato Plants in Honduras

From 2006 to 2009, all commercial potato fields in Azacualpa F.M. Honduras were heavily infested with the potato psyllid Bactericera cockerelli (Sulc.). Plants exhibited interveinal chlorosis, vein-greening, downward curling, stunting, above ground tuber formation, and brownish flecks in some tubers. Disease incidence ranged from 50 to 95%. Leaf samples and psyllids were collected from seven fields in two potato-growing regions of Honduras. Total DNA was purified from the leaves of 30 symptomatic and three asymptomatic plants. DNA was extracted from 20 adult and 10 immature (4th to 5th instar) psyllids according to Frohlich et al (1). PCR primers, PSY680F 5'-GTTCGGAATAACTGGGCGTA-3' and PSY1R 5'-CCCATAAGGGCCATGAGGACT-3', were used to amplify a 680-bp fragment of the 16S rDNA for the recently described "Candidatus Liberibacter physallaurous" (2) and "Ca. L. solanacearum" (3). PSY1R/PSY680F primer design was based on the association of a previously undescribed liberibacter with vein-greening symptoms in greenhouse tomato plants in Arizona from 2006 to 2007 (GenBank Accession No. GQ926918) that lead to the hypothesis that a similar bacterium could be associated with symptomatic potato plants in Honduras. PCR amplification, cloning, and sequencing of the resultant 16S rDNA amplicons indicated that 17 of 30 potato plants, 8 of 20 adult and 7 of 10 third to fourth instar psyllids, respectively, were positive for liberibacter based on 99 to 100% shared nucleotide sequence (nt) identity with the analogous sequence from liberibacter (EU812558 [2]). To substantiate these results, a second molecular marker was targeted using the 1611F and 480R primers (~980 bp) that amplify the 16S-23S-ITSrDNA of liberibacter (2) for selected liberibacter-positive samples (above). Amplicons of the expected size were obtained from 12 of 17 potato and 7 of 10 immature psyllids. No PCR product of the expected size was obtained from asymptomatic potato samples or the PCR negative (water) control. The resultant PCR amplicons were cloned and 12 to 15 clones per amplicon were sequenced. The sequences were aligned and the percentage pair wise nt identity was calculated by Clustal W revealing that the 16S rDNA and 16S-23S-ITS sequences, respectively, shared 99 to 100% nt identity with each other. BLAST analysis against the NCBI database indicated that the 16S rRNA sequences from potato plants (GQ926922) and immature psyllids (GQ926923), and the 16S-ITS-23S sequence from potato plants (GQ926924) and immature psyllids (GQ926925), shared 98.5 to 100% nt identity with 'Ca. Liberibacter' reported from potato (EU812556; [2,4]) and tomato (EU812558, EU812559, EU935005; [2,3]). Evidence for the widespread presence of liberibacter and the potato psyllid in potato fields in Honduras, together with foliar and tuber symptoms that are reminiscent of those recently described in potato plants in the United States affected with 'zebra chip' disease (4), suggest that a similar or identical disease of the potato also occurs in Honduras. This emergent disease poses a serious threat to potato production in Honduras and elsewhere in Central America. References: (1) D. R. Frohlich et al., Mol. Ecol. 8:1683, 1999. (2) A. K. Hansen et al. Appl. Environ. Microbiol. 78:5862, 2008. (3) L. W. Liefting et al. Plant Dis. 93:208, 2009. (4) J. E. Munyaneza et al. J. Econ. Entomol. 100:656, 2007.

First Report of "Candidatus Liberibacter psyllaurous" (synonym "Ca. L. solanacearum") Associated with 'Tomato Vein-Greening' and 'Tomato Psyllid Yellows' Diseases in Commercial Greenhouses in Arizona

During the winter of 2006-2007, plants in commercial tomato greenhouses (GH-1 and GH-2; total 320 acres [129.5 ha]) in Arizona were infested with the potato psyllid Bactericera cockerelli (Sulc) and more than 60% and ~20% of the plants, respectively, exhibited leaf curling, chlorosis, and shortened internodes. In addition, some plants in GH-1 developed an unusual 'vein-greening' phenotype. Nucleic acids were isolated from 10 symptomatic and three asymptomatic plants from each greenhouse. PCR primers designed to amplify a phytoplasma-like 16S rDNA (850 bp) yielded the expected size product from GH-1 samples, whereas samples from GH-2 and the asymptomatic samples from both greenhouses did not. Several 16S rDNA PCR products (3 of 60) when cloned and sequenced, surprisingly shared 97% homology with 'Candidatus Liberibacter asiaticus' (GenBank No. GQ926917). PCR primers PSY680F 5'-GTTCGGAATAACTGGGCGTA-3' and PSY1R 5'-CCCATAAGGGCCATGAGGACT-3', based on the resultant 16S rDNA sequences, were used to amplify a 680-bp fragment from plant DNA extracts and psyllid lysates (1). A robust PCR product (~680 bp) was obtained from 10 of 10 GH-1 plant extracts (GQ926918) and from a GH-1-derived psyllid colony (28 of 35 adults) (GQ926919) and the tomato plants on which they were reared. In contrast, no 680-bp product was obtained from GH-1 asymptomatic plants (0 of 3), GH-2 plants (0 of 10 symptomatic; 0 of 3 asymptomatic), GH-2-derived psyllid colonies (0 of 35 adults), or psyllid colony tomato plants (data not shown). At least three 680-bp amplicons for each sample type were cloned and 8 to 10 inserts were sequenced for each. BLAST analysis revealed that all 680-bp sequences shared 99 to 100% nt identity with the analogous 16SrDNA from "Ca. Liberibacter psyllaurous" (2) and synonym "Ca. L. solanacearum" (3). A second molecular marker was obtained with the 1611F and 480R primers (2) to amplify the 16SrDNA-23S-ITS (980 bp) from >3 plant extracts and psyllid lysates that tested positive for liberibacter. Clustal W alignment of the 16S-23S-ITS sequences from GH-1 original tomato plants and psyllid colony plants (GQ926920) and psyllids (GQ926921) indicated they were 100% identical to each other and BLAST analysis indicated 99 to 100% shared identity with "Ca. L. psyllaurous" (EU812558) (synonym "Ca. L. solanacearum"). Transmission electron microscopy examination of GH-1 and GH-2 psyllids revealed rod and pleomorphic-shaped bacteria (0.5 to 2.0+ μm) at the brain-salivary gland interface in psyllids from the GH-1 liberibacter-positive colony. No such bacteria were observed in GH-2 liberibacter-negative psyllids. These results support an etiological role of a new liberibacter spp. in the development of the 'vein-greening' symptom phenotype. In contrast, the GH-2 'yellows' phenotype is reminiscent of 'psyllid toxicity' in tomato colonized by B. cockerelli (4). To our knowledge, this is the first report of distinct psyllid-associated diseases in greenhouse tomato in Arizona, one associated with a new 'Ca. Liberibacter' spp., manifest as 'vein-greening' disease, and the other associated with psyllid feeding, in which liberibacter is undetectable in plants and psyllids, and is manifest as the 'tomato psyllid yellows' disease. References: (1) D. R. Frohlich et al. Mol. Ecol. 8:1683, 1999. (2) A. K. Hansen et al. Appl. Environ. Microbiol. 74:5862, 2008. (3) L. W. Liefting et al. Plant Dis. 93:208, 2009. (4) H. J. Pack. Utah Agric. Exp. Stn. Bull. 209, 1929.

Notch1 regulates the functional contribution of RhoC to cervical carcinoma progression

BACKGROUND

The role of Notch signalling in human epithelial cancers is of immense interest. In this study, we examine the interplay between Notch signalling and RhoC, a well-established molecular factor in metastasis. By linking the function of Notch and RhoC, we further strengthen the notion that there is a pro-oncogenic role of Notch signalling in human cervical cancers.

METHODS

RhoC protein expression in cervical carcinoma cell lines was assessed by western blotting. Using CaSki and SiHa cells (cervical carcinoma cells lines), we show that RhoC contributes to wound healing, invasion and migration, anoikis resistance, colony formation, in vitro tube formation and tumour formation. Immunohistochemical studies were carried out to assess the co-expression of RhoC, pAkt and Notch1 in clinical sections.

RESULTS

An assessment of the changes associated with epithelial-to-mesenchymal transition (EMT) shows that both Notch1 and RhoC have similar phenotypic contribution to EMT. Rho activity assessment on Notch1 inhibition with DAPT shows decreased RhoC activity. We further show that constitutively active RhoC rescues the phenotypic effect of Notch1 inactivation, and a comparison of Notch1 with RhoC expression shows an overlap between the two proteins in the same areas of the tissue.

CONCLUSION

This study has provided evidence to suggest that RhoC is an effector of Notch1 in cervical carcinoma.

Ventricular free wall rupture

BACKGROUND

Left ventricular free wall rupture (FWR) is reported to occur in 2-6% of cases presenting with acute myocardial infarction. Mortality of this complication is very high, accounting for 20-30% of all infarct related deaths. The objective of our study was to present our surgical experience of free wall rupture over a period of five years from 2004-2009.

METHODOLOGY

A review of our records over this period of time was undertaken.

RESULTS

In our series of six patients collected over this time period, 3 (50%) presented with hypotension and 3 (50%) with persistent chest pain ECG evidence of myocardial infarction was present in 4 (67%) cases, LVH in 2 (33.3%) cases and 2 (33.3%) showed diffuse ST and T changes. Echocardiogram was useful in the diagnosis of rupture but was not confirmatory. Coronary angiography and left ventriculography was performed in all the patients. Surgery was performed in all cases confirming the FWR.

CONCLUSION

In this sma I s,ries there was no surgical mortality which may reflect the favourable prognosis in sub acute rupture where haemodynamic stability is achieved with medical therapy prior to surgery.

Estrogen receptor genotypes, menopausal status, and the lipid effects of tamoxifen

Tamoxifen induces important changes in serum lipid profiles in some women; however, little information is available to predict which women will experience improved lipid profiles during tamoxifen therapy. As part of a multicenter prospective observational trial in 176 breast cancer patients, we tested the hypothesis that tamoxifen-induced lipid changes were associated with genetic variants in candidate target genes (CYP2D6, ESR1, and ESR2). Tamoxifen lowered low-density lipoprotein cholesterol (P<0.0001) by 23.5 mg/dl (13.5-33.5 mg/dl) and increased triglycerides (P=0.006). In postmenopausal women, the ESR1-XbaI and ESR2-02 genotypes were associated with tamoxifen-induced changes in total cholesterol (P=0.03; GG vs GA/AA) and triglycerides (P=0.01; gene-dose effect), respectively. In premenopausal women, the ESR1-XbaI genotypes were associated with tamoxifen-induced changes in triglycerides (P=0.002; gene-dose effect) and high-density lipoprotein (P=0.004; gene-dose effect). Our results suggest that estrogen receptor genotyping may be useful in predicting which women would benefit more from tamoxifen.

Abnormalities of conduction after total correction of Fallot's tetralogy: a prospective study

OBJECTIVE

To determine the frequency of post-operative conduction abnormalities in Pakistani patients undergoing total correction for Fallot's Tetralogy.

PATIENTS AND METHODS

One hundred and fifteen patients of Fallot's Tetralogy underwent definitive repair between January, 1999 and April, 2000. Their mean age was 12.89 years (range 3-30 years). One hundred nine patients (94.78%) had severe cyanosis and 6 patients (5.21%) were moderately cyanotic due to mild right ventricular outflow tract (RVOT) obstruction. Thirty percent patients required frequent hospital admissions within 6 months before the time of operation due to -hyper-cyanotic spells. The mean haematocrit was 50.83 (range 28-71). The majority of patients were in NYHA class-III (57%) and 45% had previous palliative shunt procedures done. Surgical access was through the RVOT in 90% cases and trans-atrial in 10%. RVOT patch was used in 55.9%, Pulmonary artery patch in 13.5% and trans-annular patch in 17.1% of cases.

RESULTS

The mean bypass time was 79.15 min and the mean cross clamp time 51.23 min. Average stay in the intensive care unit was 4.48 days. Twenty-three patients required re-exploration for bleeding. Sixty-nine patients required inotropic support. Fifteen patients had transient heart blocks and two had complete heart block requiring permanent pace-maker. Nineteen patients had various transient arrhythmias which were managed medically. Univariate analysis showed that higher age at operation, low preoperative heart rate, prolonged bypass time, prolonged cross clamp time and presence of patch on pulmonary artery were more common in patients who developed various heart blocks. However, none of these factors had statistical significance or definitive cause-effect relationship with heart blocks.

CONCLUSION

With careful surgical technique, total correction of Fallot's tetralogy can be conducted in children and young adults, with a very low risk of conduction abnormalities.

Solubility and precipitation of nicotinic acid in supercritical carbon dioxide

Solubilities of a model compound (nicotinic acid) in pure supercritical carbon dioxide (SC-CO(2)) and SC-CO(2) modified with methanol have been measured in the pressure range of 80-200 bar and between temperatures of 35 and 90 degrees C. On-line ultraviolet detection enabled a simple and relatively fast measurement of very low levels of solubility (10(-7) mol fraction) with good accuracy in pure and modified SC-CO(2). The solute solubility in both pure SC-CO(2) and SC-CO(2) modified with methanol increased with pressure at all investigated temperatures. A retrograde solubility behavior was observed in that, at pressures below 120 bar, a solubility decrease on temperature increase occurred. Solubility data were used to calculate supersaturation values and to define optimum operating conditions to obtain crystalline particles 1-5 microm in diameter using the solution-enhanced dispersion by supercritical fluids (SEDS) process, thereby demonstrating the feasibility of a one-step production process for particulate pharmaceuticals suitable for respiratory drug delivery.

Prognostic indicators of childhood acute viral encephalitis

OBJECTIVE

To devise a set of clinical signs and laboratory parameters that would help clinicians assess prognosis in patients and plan appropriate management.

METHODS

Medical records of 147 paediatric cases (with a discharge diagnosis of acute viral encephalitis) admitted over a ten year period from 1987 to 1997 were reviewed and relevant information collected on a data extraction form.

RESULTS

Of 147 patients, 24 (16.3%) died and 48 (32.7%) were left with severe neurological deficits. A GCS (Glasgow Coma Scale) score between 6-10 had an association with poor outcome (OR = 2.62, Chi-square = 5.57, p-value = 0.018) and that a GCS score of > or = 5 was even more strongly suggestive of poor outcome (OR = 5.49, Chi-square = 12.08, p-value = 0.0005). A history of having seizures, for more than 3 days, also showed a strong association with poor outcome (OR = 3.66, Chi-square = 5.46, p-value = 0.019).

CONCLUSION

Patients with an increased risk of death and severe disability can be identified using a few guidelines. Of these, a history of seizures of > 3 days and/or impaired consciousness (GCS < or = 10), at the time of presentation to the hospital, constitute high risk. These cases must be identified promptly and aggressive therapy initiated in order to improve long term outcome.

Anesthetic management of living liver donors

PURPOSE

Living organ donation is being performed with increasing frequency to overcome the shortage of organs for transplantation. Our experience in the anesthetic management of donors with relevant issues is discussed and complications encountered are recorded.

METHODS

Data were collected retrospectively and analyzed on all 22 left lateral hepatectomies performed at our institution between 1993 to 1997 for transplantation.

RESULTS

Major ethical concern was the risk to the donors and anesthetic issues were those of a major abdominal procedure. All except four donors were parents (mother/father). Average blood loss was 805 +/- 479 ml and only two donors required blood transfusion. Mean operative time was 8.2 +/- 1.5 hr. Thoracic epidural analgesia was the most commonly adopted mode of pain relief. Average time to return of bowel sound postoperatively was 3.1 +/- 1.0 days and was not influenced by the postoperative analgesic technique used. Total duration of hospital stay was 8.4 +/- 1.1 days. Three donors developed minor postoperative complications atrial fibrillation and retained JP drain; left lower lobe pneumonia; and incisional hernia. All patients recovered uneventfully.

CONCLUSION

Living organ donors contribute towards decreasing the shortage of organs for transplantation. Minimizing the discomfort associated with the surgical intervention and providing a complication-free perioperative course will positively influence the continued availability of such donations. On review of the first 22 left lateral hapatectomies performed, we observed only minor complications. Postoperative pain was a serious problem and thoracic epidural provided satisfactory analgesia.

Unexpected difficult intubation in the patient with Morning Glory syndrome

Morning Glory syndrome is an uncommon congenital optic disc anomaly with occasional systemic associations. A case of unsuspected difficult intubation in a three-year old patient is described in this case report.

Inflammatory disease in HLA-B27 transgenic rats

A spontaneous inflammatory disease in rats transgenic for HLA-B27 resembles the B27-associated human spondyloarthropathies. Colitis and arthritis, the two most important features, require T cells, gut bacteria, and high expression of B27 in bone marrow-derived cells. Control rats with HLA-B7 remain healthy. Most rats with HLA-Cw6 (associated with psoriasis vulgaris) remain healthy; a minority develop mild and transient disease. Rats with a mutant B27 with a Cys67-->Ser substitution resemble wild-type B27 transgenics, but with a lower prevalence of arthritis. A similar phenotype is seen in B27 rats co-expressing a viral peptide that binds B27. Disease-prone LEW but not F344 B27 rats develop high serum IgA levels concurrent with disease progression. Colitis is associated with high interferon-gamma, arthritis with high interleukin-6. Disease is similar in B27 LEW, F344, and PVG rats, but the DA background is protective.

CONCLUSIONS

The spondyloarthropathy-like disease in rats is specific for HLA-B27 but does not require Cys67. Arthritis but not colitis is particularly sensitive to B27 peptide-binding specificity. Genetic background exerts a strong influence, but some phenotypic differences exist between permissive strains that do not influence disease susceptibility. The data favor a role for B27 peptide presentation in arthritis, but other mechanisms to explain the role of B27 have not been excluded.

The use of lidocaine for preventing the withdrawal associated with the injection of rocuronium in children and adolescents

We designed this study to examine the incidence and degree of movement after the administration of rocuronium in children and adolescents and to measure the treatment effect of lidocaine for its prevention. One hundred patients (aged 5-18 yr) were randomly assigned to two groups. After general anesthesia was induced with 5 mg/kg thiopental sodium and manual occlusion of venous outflow was performed, one group of patients received 0.1 mL/kg 1% lidocaine i.v.. A second group received 0.1 mL/kg of isotonic sodium chloride solution as a placebo control. Venous outflow occlusion was held for 15 s, released, and immediately followed by the administration of rocuronium 1 mg/kg i.v.. The patient's response to rocuronium injection was graded using a 4-point scale. We observed that the incidence of withdrawal was 84% in the placebo group and was significantly decreased to 46% in patients pretreated with lidocaine (P < 0.001). This study demonstrates that the i.v. injection of rocuronium is commonly associated with a withdrawal reaction in anesthetized pediatric patients and that this reaction can be attenuated or eliminated by pretreatment with i.v. lidocaine.

IMPLICATIONS

Pain on injection of rocuronium in pediatric patients can be alleviated by pretreatment with i.v. lidocaine.

Heat shock protein hsp70 protects cells from thermal stress even after deletion of its ATP-binding domain

Retroviral-mediated gene transfer experiments show that rodent cells become heat resistant when stably and constitutively expressing a cloned human gene encoding an intact human 70-kDa heat shock protein (hsp70). Cells expressing higher levels of the hsp70 protein generally tolerate thermal stress better, whereas cells expressing either of two mutated hsp70-encoding genes, one with a 4-base pair out-of-frame deletion and one with an in-frame deletion of codons 438-618, are heat sensitive. These results provide strong evidence that expression of hsp70 leads directly to thermal tolerance. Surprisingly, cells expressing a mutant hsp70 of a human gene missing codons 120-428 are, nevertheless, heat resistant. Because the deleted region of this mutant contains the ATP-binding domain of human hsp70, this domain appears dispensable in the hsp70-mediated protection of cells from thermal stress.

Results of gastric neutralization with hourly antacids and cimetidine in 320 intubated patients with respiratory failure

In a retrospective analysis massive upper gastrointestinal (GI) hemorrhage, defined as blood loss requiring more than two units of blood transfusion over a 24-hour period, occurred in 40 (9.5 percent) of 420 intubated, mechanically ventilated patients with respiratory failure, irrespective of the etiology of the respiratory failure. In a prospective study hourly antacid gastric neutralization, maintaining the gastric pH over 5, the incidence of massive gastric bleeding was reduced to 3 (1.4 percent) of 210 patients. In 110 additional patients, cimetidine, a histamine H2 receptor blocker, was used to prevent gastric acid secretion; 3 (2.7 percent) of 110 patients had massive upper GI bleeding; all three had solitary chronic pyloric ulcers. We conclude that gastric neutralization, either with hourly antacids or with cimetidine, is effective in reducing the incidence of massive gastric hemorrhage in intubated, mechanically ventilated patients during respiratory failure. We recommend the use of either in all intubated patients with respiratory failure. In addition, in 17 patients who had gastric bleeding at the time of transfer to the respiratory intensive care unit, gastric neutralization with hourly antacids in 14 patients and with cimetidine in three patients stopped the bleeding in all 17 patients within 24 to 48 hours.

Quality Control of Dose Calibrators

Radionuclide dose calibrators are instruments that require regular checks and proper usage to ensure that they are operating correctly. The responsibility for the accuracy of the activity and the resultant estimate of the dose delivered to the patient rests with the persons administering the radiopharmaceutical. Hence, it is essential that accurate measurements of radioactivity be provided by the dose calibrator in use in every nuclear medicine department. The routine testing of the calibrator would ensure the user that the overall characteristics of the instrument are within acceptable limits. The quality control of two dose calibrators was carried out elaborately and their performance was evaluated from various aspects of quality control such as geometry effect, instrument linearity, precision test, instrument accuracy etc. It was found that one of the calibrators was having non-linear response resulting in an error of 18% from the decay-predicted activity. It also showed a saturation effect beyond 310 mCi. Hence, it needed repair or recalibration. However, the other calibrator was working satisfactorily. This study also helped us in realizing certain operational pitfalls of the dose calibrators.

Pulmonary gangrene occurring as a complication of pulmonary tuberculosis

Eighteen well-documented cases of pulmonary gangrene as a complication of bacterial pulmonary infections have been reported in the literature. These infections were due to Klebsiellapneumoniae, Streptococcus pneumoniae, and Hemophilus influenzae. We describe four patients with pulmonary tuberculosis who developed pulmonary gangrene. Vascular thrombosis and arteritis were found in three of these four patients, and this vascular complication seems to be necessary for the development of pulmonary gangrene.