[PSA increase after definitive treatment]. / PSA-Anstieg nach definitiver Therapie.

Following definitive treatment with curative intent a subset of patients with prostate cancer experience biochemical recurrence. In these patients clinical parameters are mostly used to decide if a local or systemic disease recurrence is present. While salvage radiation treatment is advocated for local recurrence after radical prostatectomy, no standard recommendations exist in cases of local recurrence after primary radiation therapy although salvage prostatectomy may be considered. Imaging procedures have traditionally not routinely been recommended for the onset of prostate-specific antigen (PSA) relapse; however, prostate-specific membrane antigen (PSMA) positron emission tomography (PET) computed tomography (CT) exhibits high detection rates even at low PSA values. Thus, the current German guidelines state that PSMA PET/CT can be considered if this could result in a decisive change in further treatment management. Currently, a positive influence on oncological long-term outcome, however, has not yet been proven.

Tumor volume as a predictive parameter in the sequential therapy (induction chemotherapy) of head and neck squamous cell carcinomas.

PURPOSE: Tumor volume in locally advanced head and neck squamous cell carcinomas (LAHNSCC) treated by induction chemotherapy (ICT) and followed by radiochemotherapy (RCT) was measured. The presence of potential correlation of initial tumor volume and volume reduction after ICT and RCT with remission status, overall survival (OS) and disease-free survival (DFS) were investigated. Furthermore, reliability of approximation of the tumor volume relying on its diameter to manual three-dimensional measurement was assessed. METHODS: Data of patients with LAHNSCC treated by ICT consisting of docetaxel, cisplatin, and 5-fluorouracil (TPF) followed by definite RCT were retrospectively analyzed. The tumor volume was calculated slice-by-slice in contrast-enhanced CT or MRI before and after ICT as well as after complete treatment. The volume was compared to radiologic remission status, correlated with OS and DFS, and to volume estimation using tumor diameter. RESULT: 65 patients were included. Primary tumor volume did not correlate with complete remission rate (CR) after ICT and RCT, OS or DFS. The change in tumor volume between baseline imaging and post-RCT had a significant impact on OS (p = 0.026) and DFS (p = 0.028). The agreement between tumor volume and radiologic remission was 72.14%. CONCLUSION: The initial tumor volume had no influence on CR, OS or DFS. A severe response to ICT did not predict a powerful RCT outcome. The change in tumor volume post-RCT had an impact on OS and DFS. Tumor volume estimation using its diameter seems to be a reliable method.

Imaging of appendicitis in adults.

UNLABELLED: Three imaging modalities are available for the diagnosis of acute appendicitis: ultrasound (US), computed tomography (CT), and magnetic resonance imaging (MRI). Transabdominal ultrasound should be the first-line imaging test. Abdominal CT is superior to US and is required immediately in patients with atypical clinical presentation of appendicitis and suspected perforation. However, low-dose unenhanced CT is equal to standard-dose CT with intravenous contrast agents in the detection of five signs of acute appendicitis (thickened appendiceal wall more than 2 mm, cross-sectional diameter greater than 6 mm, periappendicitis, abscess, and appendicolith). MRI is necessary in pregnant women and young adults. This review illustrates the principles of state-of-the-art imaging techniques and their clinical relevance. KEY POINTS: • US is the basic diagnostic method in case of suspected appendicitis.• CT is necessary in patients with atypical presentation of appendicitis.• MRI should be the first-line imaging test in pregnant women.

Vitamin K (menaquinone) biosynthesis in bacteria: high-performance liquid chromatographic assay of the overall synthesis of o-succinylbenzoic acid and of 2-succinyl-6-hydroxy-2,4-cyclohexadiene-1-carboxylic acid synthase.

An early enzyme in menaquinone (vitamin K2) biosynthesis is the synthase forming 2-succinyl-6-hydroxy-2,4-cyclohexadiene-1-carboxylic acid (SHCHC) from isochorismic acid. In turn, SHCHC is aromatized to o-succinylbenzoic acid (OSB) by OSB synthase. An assay for the combined activity of these two enzymes ("overall OSB synthesis") has been developed using a high-performance liquid chromatographic method for the quantitation of OSB. The assay, which measures as little as 0.1 nmol of OSB, is vastly superior to the radiogas chromatographic method previously used to estimate overall OSB synthesis. To measure SHCHC synthase activity separately, the enzymatically formed SHCHC is converted nonenzymatically to OSB (heating to 80 degrees C, pH 10, 10 min), which is then quantitated by the HPLC assay. The preparation of the substrate, isochorismic acid, and its purification by preparative HPLC are also described.

Effect of a diazafluoranthen derivative on phospholipases. A study at the air-water interface.

AC-3579 (2-N-methylpiperazinomethyl-1,3-diazafluoranthen 1-oxide) produces in rat hepatocytes a hypertrophy of the endoplasmic reticulum. Two possibilities that can explain this phenomenon are (1) that AC-3579 inactivates the phospholipases, and (2) that an AC-3579-lipid interaction hinders the enzymic activity. To demonstrate these hypotheses, a physicochemical model of biological membrane, the lipid-water interface, has been used. Dipalmitoyl DL-alpha-phosphatidyl-choline was spread at the air-water interface, the enzymes (phospholipase A or phospholipase C) dissolved in the aqueous phase. The enzymic reaction was first studied with and without AC-3579 dissolved in the aqueous phase; no enzymic inactivation was observed. However an AC-3579-lipid complex completely inhibited the enzymic reaction in the case of phospholipase A. An explanation is given in terms of steric hindrance to the enzyme-substrate.