18F-FDG PET/CT in diagnosis and response evaluation in an unusual case of antisynthetase syndrome presenting as pyrexia of unknown origin.

Anti-histidyl (Jo-1) antibodies have been implicated in the pathogenesis of anti-synthetase syndrome (ASS). A case is presented of a 55-year-old male patient presenting with pyrexia of unknown origin and inconclusive routine investigations. (18)F-FDG PET/CT was performed to locate any abnormal focus, which showed increased FDG uptake in the proximal shoulder muscles, as well as lung lesions. Subsequent investigation showed the presence of anti Jo-1 antibody, and diagnosed as an anti-synthetase syndrome. The patient was successfully treated with glucocorticoids and cyclophosphamide, and the response was assessed with symptomatic relief and disappearance of FDG uptake in lung and muscle lesions on post-treatment FDG PET/CT.

Follow-up (99m)Tc EC renal dynamic scintigraphy and DMSA-III SPECT/CT in unmasking a masqueraded case of Horseshoe kidney.

Hydronephrosis is a common finding in urinary tract outflow obstruction. Chronically obstructed hydronephrotic system may be associated with parenchymal changes. Ultrasound, intravenous urography, micturating cysto-urethrogram and scintigraphy are commonly performed to evaluate the cause of obstruction. In childhood, pelviureteric junction obstruction is a common cause of the hydronephrosis. Hydronephrosis can also be present in horseshoe kidneys due to poor drainage. However, a large sized hydronephrotic cavity may obscure the finding of horseshoe kidney. A case was reported, and it was diagnosed as horseshoe kidney on follow-up renal dynamic scan and confirmed with the help of dimercaptosuccinic acid SPECT/CT.

Diagnostic accuracy of integrated (18)F-FDG PET/CT for restaging patients with malignant germ cell tumours.

OBJECTIVE: Evaluation of utility of fluorine-18 fludeoxyglucose ((18)F-FDG) positron emission tomography/CT (PET/CT) for restaging patients with primary malignant germ cell tumours (GCTs). METHODS: Data of 92 patients (age, 31.94 ± 10.1 years; male/female, 86/6) with histopathologically confirmed malignant GCTs (gonadal, 88; mediastinal, 4; seminomatous, 47 and non-seminomatous, 45) who underwent (18)F-FDG PET/CT for restaging (suspected recurrence/post-therapy evaluation) were retrospectively analysed. Two experienced nuclear medicine physicians reviewed the PET/CT images in consensus, qualitatively and semi-quantitatively [maximum standardized uptake value (SUVmax)]. Histopathology (if available) and clinical/imaging/biochemical follow-up (minimum of 6 months) were employed as the reference standard. RESULTS: (18)F-FDG PET/CT was interpreted as positive in 59 and negative in 33 patients. Local disease was seen in 5, nodal disease in 50 and distant metastasis in 22 patients. PET/CT was true positive in 49, false positive in 10, true negative in 30 and false negative in 3 patients. (18)F-FDG PET/CT showed sensitivity, specificity, positive predictive value, negative predictive value and accuracy of 94.2%, 75.0%, 83.0%, 90.9% and 85.8% overall; 90.0%, 74.0%, 72.0%, 90.9% and 80.8% in seminomatous GCT; and 96.8%, 76.9%, 91.1%, 90.9% and 91.1% in non-seminomatous GCT, respectively. Difference in PET/CT accuracy for seminomatous and non-seminomatous GCTs was not significant (p = 0.263). PET/CT demonstrated disease in 13 patients with negative/equivocal conventional imaging findings and in 9 patients with normal tumour markers. No site- or histology-based difference was seen in SUVmax. CONCLUSION: (18)F-FDG PET/CT demonstrates high diagnostic accuracy for restaging patients with malignant GCTs. It has comparable diagnostic performance in both seminomatous and non-seminomatous malignant GCTs. ADVANCES IN KNOWLEDGE: The present article demonstrates high diagnostic accuracy of (18)F-FDG PET/CT for restaging both seminomatous and non-seminomatous malignant GCTs in a large patient population.

Activity and stability of yeast alcohol dehydrogenase (YADH) entrapped in aerosol OT reverse micelles.

The activity and stability of yeast alcohol dehydrogenase (YADH) entrapped in aerosol OT reverse micellar droplets have been investigated spectrophotometrically. Various physical parameters, e.g., water pool size, w(0), pH, and temperature, were optimized for YADH in water/AOT/isooctane reverse micelles. It was found that the enzyme exhibits maximum activity at w(0) = 28 and pH 8.1. It was more active in reverse micelles than in aqueous buffers at a particular temperature and was denatured at about 307 degrees C in both the systems. At a particular temperature YADH entrapped in reverse micelles was less stable than when it was dissolved in aqueous buffer.