Metabolically versatile psychrotolerant Antarctic bacterium Pseudomonas sp. ANT_H12B is an efficient producer of siderophores and accompanying metabolites (SAM) useful for agricultural purposes.

BACKGROUND: Bacterial siderophores are chelating compounds with the potential of application in agriculture, due to their plant growth-promoting (PGP) properties, however, high production and purification costs are limiting factors for their wider application. Cost-efficiency of the production could be increased by omitting purification processes, especially since siderophores accompanying metabolites (SAM) often also possess PGP traits. In this study, the metabolism versatility of Pseudomonas sp. ANT_H12B was used for the optimization of siderophores production and the potential of these metabolites and SAM was characterized in the context of PGP properties. RESULTS: The metabolic diversity of ANT_H12B was examined through genomic analysis and phenotype microarrays. The strain was found to be able to use numerous C, N, P, and S sources, which allowed for the design of novel media suitable for efficient production of siderophores in the form of pyoverdine (223.50-512.60 µM). Moreover, depending on the culture medium, the pH of the siderophores and SAM solutions varied from acidic (pH < 5) to alkaline (pH > 8). In a germination test, siderophores and SAM were shown to have a positive effect on plants, with a significant increase in germination percentage observed in beetroot, pea, and tobacco. The PGP potential of SAM was further elucidated through GC/MS analysis, which revealed other compounds with PGP potential, such as indolic acetic acids, organic acids, fatty acids, sugars and alcohols. These compounds not only improved seed germination but could also potentially be beneficial for plant fitness and soil quality. CONCLUSIONS: Pseudomonas sp. ANT_H12B was presented as an efficient producer of siderophores and SAM which exhibit PGP potential. It was also shown that omitting downstream processes could not only limit the costs of siderophores production but also improve their agricultural potential.

Correlation Between Percentage of Immuncompetent CD4+ and CD4+CD25+ Cells and Compatibility in the HLA System and Selected Parameters Assessing Transplanted Kidney Function.

BACKGROUND: Long-term kidney allograft survival is affected by many coexisting immunologic factors. Currently, only two basic immunologic parameters-HLA compatibility and panel reactive antibodies-are routinely used in kidney transplantation management. At the same time, there is a great need for immunologic biomarkers that will help inrease understanding of kidney transplant immunology and improve clinical care of kidney recipients. T regulatory cells (Tregs) represent one of the major targets of this approach. The aim of this study was to investigate possible simple associations between Tregs count in recipients' blood and other routinely assessed or easily accessible laboratory parameters. METHODS: Laboratory outcomes from medical files of transplant outpatient clinic in combination with flow cytometry analyses of particular immunocompetent cells populations were used. Flow cytometry was used to calculate Tregs recognized as TCD4+CD25high. The Spearman rank correlation test was used to verify particular associations. RESULTS: A negative correlation was found beween HLA compatibility and Tregs count as well as between platelets count and Tregs count. CONCLUSIONS: Whereas the negative correlation between Tregs and platelets counts may possibly mirror some recent findings in basic research, a negative correlation between HLA compatibility and Tregs points the direction of further research to factors triggering post-transplant immune tolerance.

Improving styletted oral tracheal intubation: rational use of the OTSU.

PURPOSE: To introduce an improved method of styletted oral laryngoscopic tracheal intubation. DESCRIPTION OF THE TECHNIQUE: The oral tracheal stylet unit (OTSU) is constructed using a commonly available intubating stylet combined with an ordinary endotracheal tube (ETT). The ETT/stylet is created by a series of specific steps to form an OTSU, each with a standard shape and design that allows the tracheal tube to separate freely from the stylet. After construction, every unit is tested to confirm that the frictional resistance created by the tracheal tube, as it slides along the stationary stylet, is at an absolute minimum. Successful tracheal intubation is based on the following concepts: (a) The j-shaped OTSU, when correctly directed through the airway, passes freely from the mouth to the larynx, the laryngoscopic channel; (b) The tip of the ETT must first be placed between the vocal cords with every intubation. The tracheal tube is then launched and advanced into the trachea by sliding along and off a stationary stylette; (c) Only minimal force is required to propel the ETT during intubation; (d) Resistance to placement, launch or advancement means the tip of the OTSU has come into physical contact with the patient's airway; (e) When the epiglottis obscures the larynx, the tip of the OTSU is used to explore the hypopharynx and identify the glottis. The ability to differentiate where the ETT tip is located depends primarily on interpreting the sensations of touch and pressure transmitted from the bevel of the OTSU to the hand. Successful tracheal intubation is accomplished when all criteria for placement, launch, and advancement are met. CONCLUSION: Styletted oral tracheal intubation is well known. However, we describe an improvement of the technique, based on solid physical principles and years of experience, that should prove useful both for routine intubations and unexpected difficult airways.

Keratoplasty for pseudophakic keratopathy.

Penetrating corneal grafts were performed on 15 eyes with keratopathy due to implantation of iris-supported intraocular lenses, on one eye with keratopathy due to an anterior chamber lens, and one eye with keratopathy due to a posterior chamber lens. A systematic meticulous surgical technique, with a softened eye, the use of a Flieringa ring, anterior vitrectomy and sodium hyaluronate (Healon) have resulted in clear grafts in all except in four eyes. Although most grafts have remained clear, the visual results are poor mainly due to glaucoma and/or maculopathy. Every effort was made to retain the implants and some were repositioned and sutured to the iris. Long-term postoperative follow-up, with good patient compliance and the judicious use of topical corticosteroids and timolol, is essential to maintain clear grafts.

Clinical use of the wide field specular microscope.

The Pocklington (Keeler-Konan) wide field specular microscope has been in use for 18 months at the Corneal Diseases Unit, The Royal Victorian Eye and Ear Hospital, Melbourne. In this study, the microscope has been applied clinically to assess the state of the corneal endothelium and to evaluate comparative endothelial cell density and morphology in certain anterior segment microsurgical procedures. The clinical conditions studied are primary posterior chamber intraocular lens implantation, secondary intraocular lens implantation, intraocular lens exchange, and penetrating keratoplasty.

Relocation of posterior corneal rings in clinical wide field specular microscopy.

A clinical study of posterior corneal rings in human eyes was undertaken using the Pocklington (Keeler-Konan) contact wide field specular microscope designed by Sherrard. The method used to reproduce identical posterior corneal rings in the same human cornea, in vivo, using the contact wide field specular microscope camera, without the aid of a contact lens, is described. The technique enables the clinician to relocate and evaluate a selected area of human endothelial cells in the same eye.

Clinical specular microscopy: the Australian experience.

It is almost one year since the Corneal Diseases Unit of The Royal Victorian Eye and Ear Hospital began preliminary evaluation of the Pocklington Keeler-Konan Wide-Field Specular Microscope. With this instrument, approximately one square millimetre of living human corneal endothelial cells can be observed and photographed. This relatively large area gives a far more valid assessment of endothelial cell morphology and numbers than was possible with narrow field instruments. Reproducible lines enable the relocalization of the same area of endothelium. Observations of endothelial cells have been made in health and disease, including eyes with corneal dystrophy, following cataract surgery with and without intraocular lens implantation, corneal grafting, and after the use of Healon in the anterior chamber.

Adeno-viral kerato conjunctivitis.

In summer, 1976 an epidemic of Kerato Conjunctivitis commenced in Melbourne, Australia. A total of 422 patients was studied in the adeno-viral clinic at the Royal Victorian Eye and Ear Hospital, Melbourne, from 1976 to 1979. Most patients were referred from the Casualty Department of the hospital, but others came from private practice. A total of 72 cases were adeno-viral with positive cultures. Types 8 and 19 predominated, but sporadic cases of types 1, 3, 4 and 7 were also isolated. Herpes Simplex type 1 was positive in 13 patients. The hospital staff were involved in spread of adeno-virus type 8. Six patients contracted Kerato-Conjunctivitis following removal of corneal foreign bodies from the casualty ward, and several patients contracted epidemic Kerato-Conjunctivitis after beta-irradiation post-pterygium surgery. These latter two methods of infection have not been reported before. Treatment and prevention is discussed.