Amplitude-based optimal respiratory gating in positron emission tomography in patients with primary lung cancer

Objectives

Respiratory motion during PET imaging introduces quantitative and diagnostic inaccuracies, which may result in non-optimal patient management. This study investigated the effects of respiratory gating on image quantification using an amplitude-based optimal respiratory gating (ORG) algorithm.

Methods

Whole body FDG-PET/CT was performed in 66 lung cancer patients. The respiratory signal was obtained using a pressure sensor integrated in an elastic belt placed around the patient’s thorax. ORG images were reconstructed with 50 %, 35 %, and 20 % of acquired PET data (duty cycle). Lesions were grouped into anatomical locations. Differences in lesion volume between ORG and non-gated images, and mean FDG-uptake (SUV_mean) were calculated.

Results

Lesions in the middle and lower lobes demonstrated a significant SUV_mean increase for all duty cycles and volume decrease for duty cycles of 35 % and 20 %. Significant increase in SUV_mean and decrease in volume for lesions in the upper lobes were observed for a 20 % duty cycle. The SUV_mean increase for central lesions was significant for all duty cycles, whereas a significant volume decrease was observed for a duty cycle of 20 %.

Conclusions

This study implies that ORG could influence clinical PET imaging with respect to response monitoring and radiotherapy planning.

Key Points

? Quantifying lesion volume and uptake in PET is important for patient management ? Respiratory motion artefacts introduce inaccuracies in quantification of PET images ? Amplitude-based optimal respiratory gating maintains image quality through selection of duty cycle ? The effect of respiratory gating on lesion quantification depends on anatomical location     

Pharmacokinetics of ampicillin, sulbactam and cefotiam in patients undergoing orthopedic surgery

Summary As perioperative prophylaxis for major orthopedic operations 81 patients were given the fixed combination of ampicillin (1 g)/ sulbactam (0.5 g) or cefotiam (2 g) as short infusions. The three -lactams were rapidly distributed into the different tissues and their pharmacokinetic profiles were found to be very similar. It was noteworthy that ampicillin, sulbactam and cefotiam penetrated within minutes, not only into skin, fat and muscles, but also into bone. Thus 0.25 h after starting the infusion the following mean concentrations were measured in bone: 21.8±10.5 mg/kg ampicillin, 4.9±2.2 mg/kg sulbactam and 19.4±10.6 mg/kg cefotiam. For a period of at least 2 h the concentrations measured in serum and in the different tissues affected by the operation (skin, fat, muscle, bone) were above the MICs for pathogens which are involved in postoperative wound infections. On the basis of pharmacokinetic data, ampicillin/sulbactam and cefotiam seem about equally suitable for perioperative prophylaxis in major orthopedic operations.     

Klinische Notfallmedizin – Implementierung der Simulation in die Weiterbildung

A essential milestone for continuous quality improvement in medicine is the possibility of using the latest media. In research, patient care, and clinical practice, computer-supported programs enhance knowledge and therapies; these techniques are also applicable in continuing education. With them, targeted learning and training of specific skills is possible.Simulation training provides an optimal medium for education and training at the highest quality level with repetitive failure analysis and evaluation. The possibility of goal-oriented and real-world integration of scenarios in the context of the situation at hand is specifically intended to fulfill the requirements to ensure quality of care within the increasingly professionalized field of clinical emergency medicine.Thus, the DGINA and DGSiM jointly demand that simulation training be implemented into existing and established medical and nursing qualifications.The Working Group Clinical Emergency Medicine of DGSiM represents an intersection between the German Society of Interdisciplinary Emergency and Acute Medicine (DGINA) and the German Society for the Advancement of Simulation in Medicine (DGSiM) and is formed and supported by experienced clinical emergency physicians with proven expertise in simulation training. The goal of the group is on the one hand to represent the specific aspects of clinical emergency medicine in the field of DGSiM and on the other hand in the DGINA and its member hospitals, and promote the integration of simulation—which has been documented as effective in studies—into interprofessional and continuing education.     

Testosterone, gonadotropin, and cortisol secretion in male patients with major depression.

OBJECTIVE: Previous studies of sex hormone concentrations in depression yielded inconsistent results. However, the activation of the hypothalamic-pituitary-adrenal system seen in depression may negatively affect gonadal function at every level of regulation. The objective of this study was to explore whether major depressive episodes are indeed associated with an alteration of gonadal function. METHODS: Testosterone, pulsatile LH secretion, FSH, and cortisol were assessed using frequent sampling during a 24-hour period in 15 male inpatients with major depression of moderate to high severity and in 22 healthy comparison subjects (age range 22-85 years). RESULTS: An analysis of covariance model showed that after adjustment for age only, daytime testosterone (p < .01), nighttime testosterone (p < .05), and 24-hour mean testosterone secretion (p < .01) were significantly lower in the depressed male inpatients. There was also a trend for a decreased LH pulse frequency in the depressed patients (p < .08). CONCLUSIONS: Gonadal function may be disturbed in men with a depressive episode of moderate to high severity.     

Zur Klinik der Umschriebenen Lungeneiterungen

Ohne Zusammenfassung     

Molekulare Diagnostik bei genetischen Lebererkrankungen

New insights into the genetic basis of diseases are being generated at an ever increasing rate. This review discusses the application of molecular genetics with a special focus on hereditary diseases of the liver. The application of molecular genetics in everyday clinical routine is hampered by the sometimes difficult interpretation of test results. These difficulties include the prediction of disease penetrance (e.g. in patients with a homozygous HFE C282Y mutation), the presence of multiple mutations of a particular gene (e.g. in Wilson??s disease), the presence of mutations with varying functional consequences (e.g. in genes responsible for recurrent cholestasis syndromes) and the importance of exogenous factors modulating disease expression. To date the most significant impact of genetics has been to increase our understanding of disease etiology and pathogenesis and to reliably identify siblings of affected patients with a risk to develop symptomatic disease.     

Excision of titin's cardiac PEVK spring element abolishes PKCα-induced increases in myocardial stiffness

Protein kinase C-alpha (PKCα) was recently reported to increase myocardial stiffness, an effect that was proposed to be due to phosphorylation of two highly conserved sites (S11878 and S12022) within the proline-glutamic acid-valine-lysine (PEVK) rich spring element of titin. To test this proposal we investigated the effect of PKCα on phosphorylation and passive stiffness in a mouse model lacking the titin exons that contain these two phosphorylation sites, the PEVK knockout (KO). We used skinned, gelsolin-extracted, left ventricular myocardium from wildtype and PEVK KO mice. Consistent with previous work we found that PKCα increased passive stiffness in the WT myocardium by 27 ± 6%. Importantly, this effect was completely abolished in KO myocardium. In addition, increases in the elastic and viscous moduli at a wide range of frequencies (properties important in diastolic filling) following PKCα incubation (27 ± 3% and 20 ± 4%, respectively) were also ablated in the KO. Back phosphorylation assays showed that titin phosphorylation following incubation with PKCα was significantly reduced by 36 ± 12% in skinned PEVK KO myocardial tissues. The remaining phosphorylation in the KO suggests that PKCα sites exist in the titin molecule outside the PEVK region; these sites are not involved in increasing passive stiffness. Our results firmly support that the PEVK region of cardiac titin is phosphorylated by PKCα and that this increases passive tension. Thus, the PEVK spring element is the critical site of PKCα's involvement in passive myocardial stiffness.