Search

Purpose: Imaging of moving organs using the PET leads to blurred images due to long acquisition times. Simultaneous cardiac and respiratory gating of list-mode PET/CT is evaluated with the aim to improve image quality and assess the organ movement. Methods: We performed a N-13 ammonia PET/CT scan with a human volunteer, using the Siemens Biograph Sensation 16 scanner with list-mode acquisition. For ECG gating we used the scanner's integrated ECG device. Respiratory gating was done with the BioVet pneumatic sensor system. Results: The sorting of the list-mode data post acquisition produced the desired matrix of eight cardiac times eight respiratory images. Organ movement could be measured in the series of gated PET images. The quantitation of tracer uptake in the myocardium showed artifacts due to the CT-based attenuation correction. Conclusion: Double gating is feasible in human PET/CT scans using a list-mode-based scan protocol. The image quality can be enhanced using double gated list-mode acquisition in PET/CT. Attenuation correction protocols in PET using a single not gated fast CT introduces artifacts in moving organs.

Purpose: The aim of this study was to develop ECG and respiratory gating in combination with listmode acquisition for the quadHIDAC small-animal PET scanner. Methods: ECG and respiratory gating was realized with the help of an external trigger device (BioVET) synchronized with the listmode acquisition. Listmode data of a mouse acquisition (injected with 6.5 MBq of 18F-FDG) were sorted according to three different gating definitions: 12 cardiac gates, 8 respiratory gates and a combination of 8 cardiac and 8 respiratory gates. Images were reconstructed with filtered back-projection (ramp filter), and parameters like left ventricular wall thickness (WT), wall-to-wall separation (WS) and blood to myocardium activity ratios (BMR) were calculated. Results: Cardiac gated images show improvement of all parameters (WT 2.6 mm, WS 4.1 mm, BRM 2.3) in diastole compared to ungated images (WT 3.0 mm, WS 3.4 mm, BMR 1.3). Respiratory gating had little effect on calculated parameters. Conclusion: ECG gating with the quadHIDAC can improve myocardial image quality in mice. This could have a major impact on the calculation of an image-derived input function for kinetic modelling.

Tumor size, axillary lymph node status and expression of steroid receptors are well-established prognostic factors in breast cancer. However, it is not clear if these prognostic factors are time-dependent variables and lose their significance after several years of disease-free survival. To analyse how long these factors keep their prognostic relevance survival of 1162 breast cancer patients was analysed retrospectively. The post-operative follow-up period was split into consecutive 2-year intervals and each interval was analysed for rate of recurrence and rate of tumor depending deaths. Furthermore, a multivariate analysis was performed for the total follow-up time and for the follow-up period starting 5 years after surgery. Multivariate analysis revealed tumor size, axillary lymph node status and estrogen receptor status as independent prognostic parameters. Analysing separately the rate of recurrences and tumor-related deaths during consecutive 2-year intervals, only the tumor size was a constant prognostic parameter, whereas prognostic relevance of lymph node status decreased. Estrogen receptor status associated with favourable prognosis during the first years after surgery changed to an unfavourable prognostic factor 4 years after surgery. To summarize, prognostic factors obtained at the time of surgery can lose their significance with increasing disease-free survival.

AbstractWe report a rare case of fetal goitrous hypothyroidism complicated by polyhydramnios and preterm labor in a mother without thyroid gland pathology. The diagnosis was made in the 26th week by ultrasound and cordocentesis [TSH 170 μU/ml, free T40.2 ng/dl]. The therapeutic regime required repeated fetal blood sampling for determination of thyroid hormones. Five intra-amniotic administrations of 250 μg levothyroxine (LT4) weekyl were initiated. Because of the persisting goiter and the elevated level of TSH (128 μU/ml in 32 weeks) in the fetal serum the dosage had to be adjusted to 500 μg LT4 in the next five injections. TSH in fetal serum declined to 49.2 μU/ml in 36 weeks. Normal fetal growth and an uncomplicated course of pregnancy between the 27th and 37th week of gestation were observed. Monitoring of intrauterine therapy by determination of TSH in fetal serum may provide more reliable data than measuring TSH in amniotic fluid. A review of 15 cases of fetal goitrous hypothyroidism in the English literature is presented.Copyright © 2001 S. Karger AG, Basel

Expression of a neoepitope on cytokeratin 18, recognized by the monoclonal antibody M30, is an early indicator of apoptosis in epithelial cells. The aim of this study was to determine the equilibrium between apoptosis (M30), anti-apoptosis (bcl-2), and proliferation (Ki-67) in different endometrial conditions. Paraffin-embedded samples (n 107), representing proliferative endometrium (18), secretory endometrium (19), postmenopausal endometrium (15), disordered proliferative endometrium (6), simple hyperplasia (12), complex hyperplasia (8), and endometrial adenocarcinoma (29), were evaluated immunohistochemically. The indirect streptavidin-biotin-horseradish peroxidase technique, with 3-amino-9-ethylcarbazole as the chromogen, was used to visualize the reactions. Proliferative endometrium showed high bcl-2 and Ki-67 expression levels with no M30. In the secretory phase, the balance was tipped in favor of M30 with a decrease of bcl-2 and Ki-67. Postmenopausal endometrium revealed high Ki-67 and bcl-2 expression levels and no M30. In complex hyperplasia, M30, bcl-2, and Ki-67 showed increased expression. In endometrial carcinoma, an increasing reactivity for M30 and Ki-67 was seen as the grade progressed. bcl-2 reacted weakly and only in grade 1 cancer. Immunohistochemistry facilitates the study of the expression of proteins related to cyclic endometrial activity. Interruption of these cyclic events is associated with specific disturbances in the expression patterns of these proteins.

The objective of this study was to test if specific insulin and insulin-like growth factor I (IGF I) receptors are expressed in ovarian cancer tissue. Thirteen tissue specimens from primary ovarian cancers, 1 specimen from a primary peritoneal carcinoma, 10 specimens from metastatic lesions of ovarian carcinomas, and 4 specimens from recurrent ovarian cancers together with 13 normal ovaries were tested for their content of insulin and IGF-I receptors, by the application of specific insulin and IGF-I receptor radioimmunoassays. The insulin receptor (IR) and IGF-I receptor (IGF R) content in the primary tumors varied between 23.8-321.4 and 16.4-554.2 ng/0.1 mg DNA, respectively. Metastatic lesions contained between 12.3 and 226.7 ng IR/0.1 mg DNA and between 7.5 and 459.4 ng IGF R/0.1 mg DNA. In recurrent tumors the receptor concentrations were in the range of 41.5-79.8 and 48.9-160.9 ng/0.1 mg DNA for insulin and IGF-I receptors, respectively. Normal ovarian tissue contained between 12.2 and 150.1 ng IR and between 21.4 and 420.1 ng IGF R per 0.1 mg DNA, respectively. As both insulin and IGF-I receptors are present in ovarian cancer tissue, the effects of insulin and IGF-I as potential growth factors in ovarian cancer should be further investigated.

Objective: We investigated the hypothesis that changes in blood flow in the uteroplacental and fetoplacental circulation in preeclampsia are associated with an abnormality of placental or uterine placental bed nitric oxide (NO) synthesis.Methods: We measured pulsatility indices on Doppler waveform analysis from uterine and umbilical arteries in 20 patients with preeclampsia and 14 healthy pregnant controls before elective cesarean section. During cesarean section, biopsies from the uterine placental bed and the placenta were taken and the nitric oxide synthase (NOS) activity was measured by the [3H] L-arginine-[3H] L-citrulline conversion assay in these samples.Results: The NOS activity was significantly lower in the uterine placental bed in comparison to the placental tissue (p < 0.01). Placental NOS activity was similar between patients with preeclampsia and healthy controls and in the groups with either a pathological or a normal Doppler flow in the umbilical artery. In the uterine placental bed however, NOS activity from patients with preeclampsia was significantly lower (p 0.01), whereas the blood flow resistance in the uterine arteries was elevated (p < 0.01) in comparison to healthy controls.Conclusions: Our data show that pathological Doppler waveforms in the uterine arteries of patients with preeclampsia are paralleled by diminished NOS activity in the uterine placental bed. Therefore, the compromised NO production in the uterine placental bed may play an important role in the impaired uteroplacental blood flow and potentially in some pathological features of preeclampsia such as intervillous thrombosis formation and fetal growth retardation.

Ohne Zusammenfassung:

CA-125 is an antigenic determinant expressed on ovarian cancer cells and serves as serum marker in patients with ovarian cancer. It has also been detected, however, in serum of healthy women and in patients with benign gynecologic diseases. Previous studies in patients with ovarian hyperstimulation syndrome suggested that the production of CA-125 is correlated with proliferative ovarian activity. In this study, we describe the pattern of CA-125 secretion in 13 healthy women during menstrual cycle and during hormonal contraceptive treatment. That pattern is characterized by an increase of CA-125 serum concentrations parallel to the growth of the dominant follicle. It was not observed during hormonal contraceptive treatment. We conclude that CA-125 serum levels during menstrual cycle seem to be dependent upon the cyclic changes in the female genital tract.

Zusammenfassung: Hintergrund: Die Prognose von Patientinnen mit Beckenwandrezidiv eines Zervixkarzinoms ist schlecht. Die Fünf-Jahres-Überlebensrate liegt nach ausschließlich operativer Primärtherapie für diese Patientinnen zwischen 5 und 25%. Die kombinierte operative und strahlentherapeutische Behandlung (CORT) konnte die Prognose verbessern. Zur Optimierung der Behandlungsergebnisse beim Zervixkarzinomrezidiv der Beckenwand wurde ein neues Konzept, bestehend aus radikaler Chirurgie und einer strahlenbiologisch optimierten Radiochemotherapie, entwickelt — CORCT (combined operative-and radiochemotherapy). Patienten und Methode: Nach radikaler Operation eines Beckenwandrezidivs erfolgte eine interstitielle HDR-(Ir-192-)Brachytherapie in Afterloadingtechnik (2,5 Gy, zwei Fraktionen/Tag an fünf Tagen). Additiv wurde eine Kombinationschemotherapie mit Cisplatin 25 mg/m2 KOF/Tag an fünf Tagen und 5-Fluorouracil 1000 mg/Tag an fünf Tagen durchgeführt. Nach Abschluß der Gesamttherapie wurden die Patientinnen in dreimonatigen Abständen nachuntersucht. Ergebnisse: Drei von drei ausschließlich operativ, und strahlentherapeutisch behandelten Patientinnen verstarben innerhalb von im Median acht Monaten an einer progredienten Fernmetastasierung. Nach additiver Radiochemotherapie lebten nach einer medianen Beobachtungszeit von 14 (zwölf bis 30) Monaten noch, drei von vier Patientinnen ohne Hinweis auf lokale Rezidive oder Fernmetastasen. Schlußfolgerung: Die ersten Behandlungsergebnisse mit dem neu entwickelten CORCT-Verfahren lassen auf eine Verbesserung der Prognose für Patientinnen mit Beckenwandrezidiv eines Zervixkarzinoms hoffen.

Zusammenfassung: Die Untersuchung der Herz- und Kreislaufwirkung des Aludrin bei verschiedener Applikationsweise mit der Methode der physikalischen Schlagvolumenbestimmung und die gleichzeitige Pneumotachogrammschreibung bei Gesunden und Asthmatikern zeigte folgendes:

Zusammenfassung Die Schilddrüsenfunktionsprüfung mit Hilfe verschiedener Modifikationen des Radiojodtests zeigte bei 4 von 47 poliklinischen Fettsuchtsfällen das Vorliegen einer klinisch mehr oder weniger larvierten Hypothyreose. Die Mehrzahl der Fettsüchtigen (39 und 47) zeigte bei den Radiojodtesten ein normales Verhalten, 2 Fälle wiesen eine eindeutige hyperthyreotische Reaktion auf.

Zusammenfassung Es wird ein Verfahren mitgeteilt, das genauere Aussagen über die Jodaffinität der Schilddrüse aus der Messung der Radiojodausscheidung im Harn ermöglicht. Die Darstellung einfacher Relationen der J131-Ausscheidungsgeschwindigkeit ist im Gegensatz zum Wert der 24- oder 48-Std-Ausscheidung, der in Prozent der Dosis ausgedrückt wird, von zahlreichen Fehlermöglichkeiten unabhängig; sie ermöglicht es, eine durch hyperthyreotisch gesteigerte Jodaffinität der Schilddrüse bedingte niedrige J131-Ausscheidung von einem ähnlich niedrigen Wert zu unterscheiden, der durch Störungen oder Fehler bei der Durchführung des Tests (unvollständige Resorption, Radioaktivitätsverluste usw.) bedingt ist.

In situmeasurements are reported giving insight into the plasma chemical conversion of the precursor BCl3in industrial applications of boriding plasmas. For the online monitoring of its ground state concentration, quantum cascade laser absorption spectroscopy (QCLAS) in the mid-infrared spectral range was applied in a plasma assisted chemical vapor deposition (PACVD) reactor. A compact quantum cascade laser measurement and control system (Q-MACS) was developed to allow a flexible and completely dust-sealed optical coupling to the reactor chamber of an industrial plasma surface modification system. The process under the study was a pulsed DC plasma with periodically injected BCl3at 200 Pa. A synchronization of the Q-MACS with the process control unit enabled an insight into individual process cycles with a sensitivity of $10^{-6}$ cm-1$\cdot$Hz-1/2. Different fragmentation rates of the precursor were found during an individual process cycle. The detected BCl3concentrations were in the order of $10^{14}$ molecules$\cdot$cm-3. The reported results of in situmonitoring with QCLAS demonstrate the potential for effective optimization procedures in industrial PACVD processes.

Protein synthesizing particles from rat liver sedimented more slowly after incubation under protein synthesis conditions. This change paralleled the degree of leucine incorporation which is stimulated by added RNA. Both effects seemed to be specific.