Monitoring the colonization of sugarcane and rice plants by the endophytic diazotrophic bacterium Gluconacetobacter diazotrophicus marked with gfp and gusA reporter genes

AIMS

To evaluate the colonization process of sugarcane plantlets and hydroponically grown rice seedlings by Gluconacetobacter diazotrophicus strain PAL5 marked with the gusA and gfp reporter genes.

METHODS AND RESULTS

Sugarcane plantlets inoculated in vitro with PAL5 carrying the gfp::gusA plasmid pHRGFPGUS did not present green fluorescence, but beta-glucuronidase (GUS)-stained bacteria could be observed inside sugarcane roots. To complement this existing inoculation methodology for micropropagated sugarcane with a more rapid colonization assay, we employed hydroponically grown gnotobiotic rice seedlings to study PAL5-plant interaction. PAL5 could be isolated from the root surface (10(8) CFU g(-1)) and from surface-disinfected root and stem tissues (10(4) CFU g(-1)) of inoculated plants, suggesting that PAL5 colonized the internal plant tissues. Light microscopy confirmed the presence of bacteria inside the root tissue. After inoculation of rice plantlets with PAL5 marked with the gfp plasmid pHRGFPTC, bright green fluorescent bacteria could be seen colonizing the rice root surface, mainly at the sites of lateral root emergence, at root caps and on root hairs.

CONCLUSION

The plasmids pHRGFPGUS and pHRGFPTC are valid tools to mark PAL5 and monitor the colonization of micropropagated sugarcane and hydroponic rice seedlings.

SIGNIFICANCE AND IMPACT OF THE STUDY

These tools are of use to: (i) study PAL5 mutants affected in bacteria-plant interactions, (ii) monitor plant colonization in real time and (iii) distinguish PAL5 from other bacteria during the study of mixed inoculants.

Flat detector CT in the evaluation of brain parenchyma, intracranial vasculature, and cerebral blood volume: a pilot study in patients with acute symptoms of cerebral ischemia

BACKGROUND AND PURPOSE

The viability of both brain parenchyma and vascular anatomy is important in estimating the risk and potential benefit of revascularization in patients with acute cerebral ischemia. We tested the hypothesis that when used in conjunction with IV contrast, FD-CT imaging would provide both anatomic and physiologic information that would correlate well with that obtained by using standard multisection CT techniques.

MATERIALS AND METHODS

Imaging of brain parenchyma (FD-CT), cerebral vasculature (FD-CTA), and cerebral blood volume (FD-CBV) was performed in 10 patients. All patients also underwent conventional multisection CT, CTA, CTP (including CBV, CTP-CBV), and conventional catheter angiography. Correlation of the corresponding images was performed by 2 experienced neuroradiologists.

RESULTS

There was good correlation of the CBV color maps and absolute values between FD-CBV and CTP-CBV (correlation coefficient, 0.72; P < .001). The Bland-Altman test showed a mean difference of CBV values between FD-CT and CTP-CBV of 0.04 ± 0.55 mL/100 mL. All vascular lesions identified with standard CTA were also visualized with FD-CTA. Visualization of brain parenchyma by using FD-CT was poor compared with that obtained by using standard CT.

CONCLUSIONS

Both imaging of the cerebral vasculature and measurements of CBV by using FD-CT are feasible. The resulting vascular images and CBV measurements compared well with ones made by using standard CT techniques. The ability to measure CBV and also visualize cerebral vasculature in the angiography suite may offer significant advantages in the management of patients. FD-CT is not yet equivalent to CT for imaging of brain parenchyma.

[Children with bronchial asthma: effects of an integrated health-care programme]

BACKGROUND

On 1 (st) June 2005 a contract for an integrated health-care programme (IHP) for infants, children and juveniles with bronchial asthma (2 to 18-year-olds) was concluded. Care providers are specialised paediatricians (PaedNetz Bayern) and two rehabilitation clinics; cost payers are two Bavarian health insurances (DAK, TK).

METHODS

With a questionnaire (Q5) the following 5 items were collected every 12 months: absent days, hospital admissions, days at hospital, emergency visits and use of relievers. To estimate the adherence to the German asthma guidelines, every 6 months the symptoms, therapy and consecutive procedures were recorded.

RESULTS

At the end of 2008, 1280 patients had participated; the follow-up showed a significant reduction of the Q5 items 2 years later. The comparison of patients who had already participated for at least 12 months in the IHP with patients who have just started to participate showed significant reductions (p < 0.05) of all Q5 items between 54 % and 85 %. According to the guidelines - 6 months after starting the IHP - in 25 % a more intense therapy would be helpful. This percentage declines to 17 % at 24 months (p < 0.05).

CONCLUSION

Children and juveniles with bronchial asthma who are treated by specialised paediatricians and rehabilitation clinics by means of an integrated health-care program show a significant reduction of absent days, emergency visits, hospitalisations, days in hospital and use of relievers.

Single versus bilateral external ventricular drainage for intraventricular fibrinolysis in severe ventricular haemorrhage

BACKGROUND

Intraventricular fibrinolysis (IVF) through bilateral external ventricular drains (EVD) may provide better access of the thrombolytic agent to the intraventricular clot, potentially influencing clot clearance and outcome.

METHODS

Patients with spontaneous ganglionic intracerebral haemorrhage (ICH)<40 cm(3) and intraventricular haemorrhage (IVH) with acute hydrocephalus have been treated with IVF. The decision for placement of one or two EVDs has been left to the discretion of the treating physician. CT volumetry, the effects on cerebrospinal fluid (CSF) circulation and outcome at 3 months have been analysed for patients with one (group I, n = 13) or two EVDs (group II, n = 14).

RESULTS

No difference was found in clot resolution between the two groups (clot half life 2.1 (SD 1.2) vs 2.4 (1.3) days). A separate analysis of the third and fourth ventricle clearance was similar (1.6 (0.6) versus 1.8 (0.8) days), indicating no difference in reconstitution of CSF circulation. A trend towards a longer EVD duration and higher infection rate was found in the bilateral EVD group. No difference was found in outcome at 3 months.

CONCLUSIONS

Our results do not support the use of bilateral EVDs for IVF in patients with severe IVH.

Smell and taste disorders in polyneuropathy: a prospective study of chemosensory disorders

OBJECTIVE

The aim of the study was to assess the occurrence and the frequency of chemosensory dysfunction in patients with polyneuropathy (PNP).

METHODS

We performed a prospective observational study. Olfactory function was assessed using the standardized 'Sniffin' Sticks' test to measure odor threshold for phenyl ethyl alcohol, odor discrimination, and odor identification. Gustatory function was assessed using the standardized 'taste strips' test. In addition, we assessed etiology, neurophysiology, and severity of the PNP, and the patients' comorbidities and medication.

RESULTS

A total of 53 consecutive patients were enrolled (15 women, 38 men; mean age 61 years); 27 of them (51%) exhibited olfactory dysfunction and 23 of them (43%) gustatory dysfunction. Patients with diabetic PNP had significantly lower taste scores than patients with inflammatory, genetic, or idiopathic PNP. In addition, odor identification was negatively correlated with PNP severity.

CONCLUSION

The applied bedside tests are useful to detect chemosensory dysfunction in patients with PNP. Chemosensory dysfunction is quite frequent in these patients.

[Treatment of intraventricular hemorrhage and hydrocephalus]

Most cases of intraventricular hemorrhage (IVH) occur secondary to spontaneous intracerebral or subarachnoid hemorrhage. The main concern is development of hydrocephalus, which is related to a poor prognosis. Over the last years, several treatment options for IVH have been introduced, but prospective data regarding the efficacy of those therapies (external ventricular drainage, intraventricular fibrinolysis, lumbar drainage, endoscopic hematoma evacuation) do not yet exist. This review focuses on combined therapy using an external ventricular drain and intraventricular fibrinolysis with r-TPA for IVH-associated initial occlusive hydrocephalus. Moreover, a continuing treatment strategy for persistent malresorptive communicating hydrocephalus using lumbar drainage is described.