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We conducted a prospective multicenter trial to compare the usefulness of 11C‐methionine (MET) and 18F‐fluorodeoxyglucose (FDG) positron emission tomography (PET) for identifying tumor recurrence. Patients with clinically suspected tumor recurrence after radiotherapy underwent both 11C‐MET and 18F‐FDG PET. When a lesion showed a visually detected uptake of either tracer, it was surgically resected for histopathological analysis. Patients with a lesion negative to both tracers were revaluated by magnetic resonance imaging (MRI) at 3 months after the PET studies. The primary outcome measure was the sensitivity of each tracer in cases with histopathologically confirmed recurrence, as determined by the McNemar test. Sixty‐one cases were enrolled, and 56 cases could be evaluated. The 38 cases where the lesions showed uptake of either 11C‐MET or 18F‐FDG underwent surgery; 32 of these cases were confirmed to be subject to recurrence. Eighteen cases where the lesions showed uptake of neither tracer received follow‐up MRI; the lesion size increased in one of these cases. Among the cases with histologically confirmed recurrence, the sensitivities of 11C‐MET PET and 18F‐FDG PET were 0.97 (32/33, 95% confidence interval [CI]: 0.85‐0.99) and 0.48 (16/33, 95% CI: 0.33‐0.65), respectively, and the difference was statistically significant (P <.0001). The diagnostic accuracy of 11C‐MET PET was significantly better than that of 18F‐FDG PET (87.5% vs. 69.6%, P =.033). No examination‐related adverse events were observed. The results of the study demonstrated that 11C‐MET PET was superior to 18F‐FDG PET for discriminating between tumor recurrence and radiation‐induced necrosis. [ABSTRACT FROM AUTHOR]

Experimental studies enable the isolation of spontaneous mutants of Salmonella typhimurium exhibiting ability to swim in the presence of antifilament antibodies. Analysis of the domains structures of flagellins associated with two mutants by trypsin digestion reveals that the two flagellins exhibit deletions at Ala-204 to Lys-292 and Thr-183 to Lys-279, respectively. Outer domains of flagellin have these deleted portions, and side by side aggregation of these mutant filaments leads to motility disorder.

Electron micrograph measurements of flagellar hook lengths in mutant and wild-type cells of Salmonella typhimurium reveal that the flik polyhook mutants have broader hook length distributions between 40 and 900 nm, compared to the narrow 55.0 plus or minus 5.9 nm range of wild-type cells. The broad distribution range of the mutants confirms their involvement in defining the hook length. Flik intragenic suppressors isolated from the flik mutants produce polyhook filaments that are longer than the hooks, with abnormal length produced by flhB intragenic suppressors. A double mutation in flgK and flhB results in polyhooks.

Mutations in the fliG and fliN genes of Salmonella typhimurium that cause defects in assembly, rotation and switching of the flagellar motor were analyzed. In all three proteins, many of the mutations causing failure of flagellar assembly are nonsense or frameshift mutations. Theresults show that the three switch proteins are not active participants in the flagellar assembly but are necessary for the completion of the assembly.

A model was developed for the flagellar switching mechanism in Salmonella typhimurium involving flagellar proteins and chemotaxis proteins (CheY and CheZ). Suppressor mutation analysis showed that most of the easily derived suppresor mutations mapped in a single domain within the FliM protein, resulting in pseudorevertants for cheY or cheZ mutants. The suppression was the result of an opposing shift in switch bias. The results suggest the existence of two alternate states in the flageller switch, stabilized by interactions among the flagellar proteins. Results also suggested the importance of electrostatic forces in these interactions.

Objective: Most types of intracranial germ cell tumors (IGCTs) are sensitive to chemoradiation. However, biopsy specimens are usually small and thus cannot be used for obtaining an accurate pathological diagnosis. Recently, the cerebrospinal fluid (CSF) placental alkaline phosphatase (PLAP) value has been considered a new biomarker of IGCTs. The present study aimed to evaluate the discriminatory characteristics of the CSF-PLAP value upon diagnosis and at the time of recurrence in patients with IGCTs. Methods: Between 2015 and 2019, this study included 37 patients with tumors located in the intraventricular and/or periventricular region. The CSF-PLAP level was assessed before the patients received any treatment. The PLAP level was evaluated during and after first-line chemoradiotherapy in 7 patients with IGCTs. The CSF-PLAP values were compared according to histological diagnosis, and the correlation between these values and radiographical features was assessed. The CSF-PLAP values of 6 patients with IGCTs with suspected recurrence were evaluated based on neuroimaging findings. Results: The CSF-PLAP values were significantly higher in patients with IGCTs than in those with other types of brain tumor (n = 19 vs. 18; median: 359.0 vs. <8.0 pg/mL). The specificity and sensitivity were 88 and 95%, respectively, with a cutoff value of 8.0 pg/mL. In patients with IGCT, the CSF-PLAP value was higher in patients with germinoma than in those with nongerminomatous germ cell tumors (n = 12 vs. 7; median: 415.0 vs. 359.0 pg/mL). Regarding the time course, the CSF-PLAP value decreased to below the detection limit after the reception of first-line chemoradiotherapy in all 7 patients. A significant correlation was observed between the initial CSF-PLAP value and the tumor reduction volume after receiving first-line chemoradiotherapy (p < 0.0003, R2 = 0.6165, logY = 1.202logX – 1.727). Among the patients with suspected IGCT recurrence (n = 6), the CSF-PLAP value was high in patients with recurrence (n = 3; median: 259.0 pg/mL), and that in patients (n = 3) without recurrence was below the lower detection limit. Conclusions: The CSF-PLAP level is a useful biomarker during the initial diagnosis of IGCTs and at the time of recurrence. It may be associated with the volume of germinomatous components of tumors. [ABSTRACT FROM AUTHOR]

Highly stable [[eta].sup.]-porphyrin Ru(II) [pi] complexes are prepared and the formation of the [[eta].sup.2] [pi] bond is facilitated through [pi]-[pi] stacking interactions between the porphyrin and the planar ligand on Ru. [pi] Coordination of ruthenium to porphyrin has resulted in changes in the aromaticity and electronic properties, which are controllable via fine-tuning of the ligand on ruthenium.

The construction of metal-bridged cofacial diporphyrin architecture through a cyclometalation strategy and their dynamic helical conformational change by reduction of the bridge are described. The platinum bridge has offered a conformationally flexible nature to the complexes due to the susceptibility of platinum toward redox reaction and these complexes have displayed helical chirality.

The synthesis of heterobimetallic porphyrin pincer complexes is described. X-ray analyses have shown that these complexes have displayed a different catalytic activity in the typical Heck reaction depending on the central metals.