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Biomedical subjects

D Guven

Publications and source records attributed to D Guven.

3 recordsLinked to original sources

Isolated hepatic tuberculous abscess in a renal transplant recipient.

Tuberculous liver abscess is rare worldwide. We report a 26-year-old renal transplant recipient who presented with fever, fatigue, and weight loss. Ultrasound (US) of the abdomen showed a cystic mass of 7x6 cm in the subcapsular region of right liver lobe. US-guided percutaneous drainage was performed and 100 mL of yellow-colored pus was aspirated. The patient was empirically started on ampicillin sulbactam treatment. Despite this treatment, the symptoms persisted. Subsequent control abdominal US showed the persistence of a cystic mass of 7x6 cm with thin septation in the subcapsular region near the right liver lobe, which were subsequently diagnosed as a focal hepatic tuberculous abscess by positive culture in Löwenstein-Jensen medium. He was concomitantly started on systemic antituberculous therapy. A tuberculous liver abscess must be considered in the differential diagnosis. Percutaneous drainage along with systemic antituberculous chemotherapy must be considered as an alternative to surgery for the management. A greater awareness of this clinical entity is required for successful treatment.

Adult↗

Global impact and application of the anaerobic ammonium-oxidizing (anammox) bacteria.

In the anaerobic ammonium oxidation (anammox) process, ammonia is oxidized with nitrite as primary electron acceptor under strictly anoxic conditions. The reaction is catalysed by a specialized group of planctomycete-like bacteria. These anammox bacteria use a complex reaction mechanism involving hydrazine as an intermediate. The reactions are assumed to be carried out in a unique prokaryotic organelle, the anammoxosome. This organelle is surrounded by ladderane lipids, which make the organelle nearly impermeable to hydrazine and protons. The localization of the major anammox protein, hydrazine oxidoreductase, was determined via immunogold labelling to be inside the anammoxosome. The anammox bacteria have been detected in many marine and freshwater ecosystems and were estimated to contribute up to 50% of oceanic nitrogen loss. Furthermore, the anammox process is currently implemented in water treatment for the low-cost removal of ammonia from high-strength waste streams. Recent findings suggested that the anammox bacteria may also use organic acids to convert nitrate and nitrite into dinitrogen gas when ammonia is in short supply.

Acids↗