Furan oligomers and beta-carbolines from terrestrial streptomycetes

2,5-Bis(hydroxymethyl)furan monoacetate (3) and 2,5-bis(hydroxymethyl)furan diacetate (4) were obtained as new natural products from an ethyl acetate extract of the terrestrial Streptomyces sp. isolate GW11/1695. Another Streptomyces isolate, GW21/1313, delivered a dimer (6) and a trimer (7) of (hydroxymethyl)furfural. The latter strain also produced 4-hydroxy-2-(5-(hydroxymethyl)furan-2-ylmethylene)-5-methylfuran-3-one (5), perlolyrin (8), and two new beta-carboline derivatives, 9 and 10. 2,5-Bis(hydroxymethyl)furan diacetate (4) exhibited weak cytotoxic activity against brine shrimp larvae.     

Hualyzin, a symmetrical urea derivative isolated from Penicillium herquei isolate GA4

Penicillium herquei isolate GA4 was isolated from the infected Conchocelis of Porphyra yezoensis. A large-scale fermentation using yeast extract sucrose medium and repeated chromatography afforded a new symmetrical urea derivative, hualyzin (1). The structure was determined by detailed NMR spectroscopic investigations and MS fragmentation analysis.     

Occult lung infarction may induce false interpretation of 18F-FDG PET in primary staging of pulmonary malignancies

Purpose The aim of the present report is to describe abnormal ¹⁸F-fluorodeoxyglucose (FDG) accumulation patterns in the pleura and lung parenchyma in a group of lung cancer patients in whom lung infarction was present at the time of positron emission tomography (PET).Methods Between November 2002 and December 2003, a total of 145 patients (102 males, 43 females; age range 38–85 years) were subjected to whole-body FDG PET for initial staging (n=117) or restaging (n=11) of lung cancer or for evaluation of solitary pulmonary nodules (n=17). Of these patients, 24 displayed abnormal FDG accumulation in the lung parenchyma that was not consistent with the primary lesion under investigation (ipsilateral n=12, contralateral n=9 or bilateral n=3). Without correlative imaging, this additional FDG uptake would have been considered indeterminate in differential diagnosis.Results Of the 24 patients who were identified as having such lesions, six harboured secondary tumour nodules diagnosed as metastases, while in three the diagnosis of a synchronous second primary lung tumour was established. Additionally, nine patients were identified as having post-stenotic pneumonia and/or atelectasis (n=6) or granulomatous lung disease (n=3). In the remaining six (4% of all patients), a diagnosis of recent pulmonary embolism that topographically matched the additional FDG accumulation (SUV_max range 1.4–8.6, mean 3.9) was made. Four of these six patients were known to have pulmonary embolism, and hence false positive interpretation was avoided by correlating the PET findings with those of the pre-existing diagnostic work-up. The remaining two patients were harbouring small occult infarctions that mimicked satellite nodules in the lung periphery. Based on histopathological results, the abnormal FDG accumulation in these two patients was attributed to the inflammatory reaction and tissue repair associated with the pathological cascade of pulmonary embolism.Conclusion In patients with pulmonary malignancies, synchronous lung infarction may induce pathological FDG accumulation that can mimic active tumour manifestations. Identifying this potential pitfall may allow avoidance of false positive FDG PET interpretation.     

Parathyroid gland radionuclide scanning--methods and indications

The usefulness of preoperative radionuclide scanning of the parathyroid glands in patients with primary or secondary hyperparathyroidism was long controversial because available techniques were of limited diagnostic efficacy. Technetium-99m-labeled sestamibi (99Tc-sestamibi) is a new radiopharmaceutical agent easily detected by gamma cameras. The first parathyroid imaging studies done with 99Tc-sestamibi about 10 years ago used a double-phase technique to separate thyroid and parathyroid tissue. Although promising, this method was less than ideal, particularly in multiple gland primary hyperparathyroidism and in secondary hyperparathyroidism. For several years, we have been using subtraction between two images acquired simultaneously, one with 99Tc-sestamibi, which binds to thyroid and parathyroid tissue, and the other with 123-iodine, which binds only to thyroid tissue. The remarkable efficacy of this technique in both primary and secondary hyperparathyroidism invites a reappraisal of the place of radionuclide imaging as a preoperative localization procedure done to reduce the need for repeat surgery. The usefulness of this technique in selecting candidates for unilateral surgery among patients with primary hyperparathyroidism is discussed.