Visualization of 3-D treatment plans with fast neutrons.

The treatment planning for radiotherapy with fast neutrons requires modifications of the planning systems used for photons. The neutron- and photon-component of the treatment fields must be determined and can then be used for separate calculations. The corrections for inhomogeneities are performed by use of attenuation coefficients and the corresponding corrections for changes in the kerma. The treatment planning system MEVAPLAN (Siemens) was modified to follow these requirements. Thus treatment planning for 14 MeV DT-neutrons could be performed. The multiplanar option is used to calculate 3D-dose distributions based on up to 40 serial CT slices. The generated three-dimensional dose matrix and the CT data are transferred via magnetic tape to the visualization system VOXEL-MAN developed at the University Hospital of Hamburg. This system uses a ray casting algorithm based on the generalized Voxel-model to display detailed 3D-images of human anatomy together with the calculated dose distribution. Different treatment plans for neutrons and photons are calculated and visualized. Various manipulations of the data-sets are displayed to improve the critical examination of the simulated dose distribution and to discern the quality of treatment techniques.     

Lipodermatosclerosis: review of cases evaluated at Mayo Clinic.

BACKGROUND: Lipodermatosclerosis describes bound-down, sclerotic skin involving the lower extremities. OBJECTIVE: Our purpose was to describe the demographic and clinical features of patients with lipodermatosclerosis. METHODS: This was a retrospective study of patients presenting to Mayo Clinic between 1976 and 1998 with a diagnosis of lipodermatosclerosis. RESULTS: Of 97 patients, 84 (87%) were women. Mean age was 62 years (range, 25-88 years). Mean body mass index was 34.3 (range, 17.8-71.5). Clinical signs were bilateral involvement in 44 patients (45%), induration localized to a discrete plaque in 49 (51%), erythema in 69 (71%), hyperpigmentation in 57 (59%), ulceration in 13 (13%), concomitant edema in 69 (71%), and varicosities in 55 (57%). Vascular studies performed on 72 patients showed abnormalities in 49: deep venous incompetence in 33 (67%), calf muscle pump abnormality in 19 (39%), abnormal pulsatility in 10 (20%), and obstruction in 1 (2%). CONCLUSION: Lipodermatosclerosis was associated with female sex, middle age, high body mass index, and venous abnormalities.     

Der chirurgische Part im Rahmen multimodaler Therapiekonzepte in der Onkologie-Schilddrüse

29. Tagung der ?sterreichischen Gesellschaft für Chirurgie und Ihrer Assoziierten Fachgesellschaften Innsbruck, 2. bis 4. Juni 1988 Herausgeber: E. Bodner und G. Szinicz Abstracts

Der chirurgische Part im Rahmen multimodaler Therapiekonzepte in der Onkologie-Schilddrüse     

Changes in triceps surae muscle architecture with sarcopenia

AIM: To investigate whether sarcopenia was evenly distributed among the three components of the triceps surae (TS) muscle group. METHODS: Muscle volume (VOL), fibre fascicle length (Lf), pennation angle (theta) and physiological cross-sectional area (PCSA = VOL/Lf) were measured in vivo for the lateral (GL) and medial (GM) heads of the gastrocnemius muscles and for the soleus muscle (SOL), in 15 young males (YM, aged 25.3 +/- 4.5 years) and 12 elderly males (EM aged 73.8 +/- 4.4 years). RESULTS: In the EM, VOL of all three muscles was significantly smaller than in the YM; differences were: 27% for the GL (P < 0.01), 29% for the GM (P < 0.01) and 17% for the SOL (P < 0.05). In total, TS VOL was 22% smaller in EM than in YM (P < 0.01). In the EM, values of theta were significantly smaller than in the YM; by 15-18% for the GL, GM and SOL (P < 0.05). In the EM, Lf of the GM was 16% smaller than in the YM (P < 0.01); no significant differences were found in the other muscles. PCSA of the GL and GM were both found to be smaller in EM by 19% (P < 0.01) and 14.5% (P < 0.05), respectively. No difference was observed in the SOL PCSA between YM and EM. Interestingly, probably because of the prevalent contribution of the SOL to PCSA distribution of each muscle to the TS PCSA, the relative TS PCSA was not different between YM and EM. Furthermore, the Lf/muscle length ratio did not differ between YM and EM. CONCLUSION: The present study shows that the relative PCSA composition of the TS is maintained with ageing and that the PCSA is scaled down harmonically with the decrease in muscle volume and fascicle length. Such observation suggests that the relative contribution of the components of the TS muscle to the total force developed by this muscle group is maintained with ageing.     

Euthanasia in the Third Reich--only a problem of psychiatry? On the development of the euthanasia debate 1933-1941 in Germany

The devastating consequences of the Fascist dictatorship in Germany for the ethical thinking of the physicians are particularly clearly recognizable by the mass killings of severely damaged children and patients with chronic psychic diseases which were performed at that time. Recent investigations of the developments which began in 1938 show that by way of intensive efforts for a juridicial legalization of the "active euthanasia" an enlargement of this killing practice has been striven after. References to a motive of compassion and the free decision of the affected persons should cover the real intention for reducing welfare services. A bill presented in 1940 for a law "on euthanasia for incurable ill persons" found the unanimous consent of the renowned physicians consulted for this purpose. Though this law finally did not become legal beginning with 1941 the medical practice showed further forms of the repressive and antihumane association with ill persons who were regarded as incurable, which must be valuated as practical consequences of an unadmissible relativation of the life-preserving task of medicine.     

Identifying alcohol-related harm in young drinkers: the role of accident and emergency departments

Data are presented from a screening study of ambulant attendees at two London Accident and Emergency (A&E) departments. Among young people (aged 16-24 years), 37.2% were drinking harmfully [an Alcohol-Use Disorders Identification Test (AUDIT) score of 8 or more]; 17.3% admitted to drinking alcohol in the 6 h prior to attendance; and 14.6% considered that their attendance was alcohol related. Young women were as likely as men to score 8 or over. This age group had nearly twice the odds of scoring highly on the AUDIT, compared to those over 25 years old, and were more likely to report that their attendance was alcohol related. Screening in A&E departments would identify considerable numbers of young people who might benefit from brief intervention, but the problems of doing so are acknowledged.     

Assessment of the mutagenicity of dichloroacetic acid in lacI transgenic B6C3F1 mouse liver

Dichloroacetic acid (DCA) is a chlorination byproduct found in finished drinking water. When administered in drinking water this chemical has been shown to produce hepatocellular adenomas and carcinomas in B6C3F1 mice over the animal's lifetime. In this study, we investigated whether mutant frequencies were increased in mouse liver using treatment protocols that yielded significant tumor induction. DCA was administered continuously at either 1.0 or 3.5 g/l in drinking water to male transgenic B6C3F1 mice harboring the bacterial lacI gene. Groups of five or six animals were killed at 4, 10 or 60 weeks and livers removed. At both 4 and 10 weeks of treatment, there was no significant difference in mutant frequency between the treated and control animals at either dose level. At 60 weeks, mice treated with 1.0 g/l DCA showed a 1.3-fold increase in mutant frequency over concurrent controls (P = 0.05). Mice treated with 3.5 g/l DCA for 60 weeks had a 2.3-fold increase in mutant frequency over the concurrent controls (P = 0.002). The mutation spectrum recovered from mice treated with 3.5 g/l DCA for 60 weeks contained G:C-->A:T transitions (32.79%) and G:C-->T:A transversions (21.31%). In contrast, G:C-->A:T transitions comprised 53.19% of the recovered mutants among control animals. Although only 19.15% of mutations among the controls were at T:A sites, 32.79% of the mutations from DCA-treated animals were at T:A sites. This is consistent with the previous observation that the proportion of mutations at T:A sites in codon 61 of the H-ras gene was increased in DCA-induced liver tumors in B6C3F1 mice. The present study demonstrates DCA-associated mutagenicity in the mouse liver under conditions in which DCA produces hepatic tumors.      

Fatty acid balance studies in term infants fed formula milk containing long-chain polyunsaturated fatty acids

Long-chain polyunsaturated fatty acids (LCP) are thought to be required for optimal nervous system development in the newborn. A commercial milk formula containing LCP (Aptamil-LCP) with a fatty acid profile closely resembling breast milk, has recently been introduced for term infants. The absorption of fatty acids in term infants was examined in a double-blind randomized controlled trial comparing Aptamil-LCP ( n = 20) and standard Aptamil ( n = 20). Formula-fed newborn infants were studied from birth for 14 d. Fat balances (3 d) were performed from d 10. A 3-d stool collection was performed from d 10 in a parallel breastfed group ( n = 21). Plasma samples were taken on d 6. Median fat excretion (mg kg⁻¹) was 897.1, 615.0 and 355.2 with Aptamil, Aptamil-LCP and breastfeeding, respectively. The median total fat absorption coefficient in Aptamil-LCP-fed infants was higher than in those fed standard Aptamil ( p < 0:01). These findings were accounted for by differences in the excretion and absorption of long-chain saturated fatty acids (C14:0, C16:0 and C18:0). Higher fat excretion was associated with bulkier and firmer stools. Only trace amounts of LCP were detected in the stools of all groups. This accounted for less than 4% of dietary intake in Aptamil-LCP-fed infants. No differences in the utilization of LCP from Aptamil-LCP and breast milk feeding were apparent. Plasma phospholipid fatty acid composition data reflected differences in dietary LCP intake. Thus, PL LCP levels were highest in the breastfed infants and lowest in the Aptamil-fed infants, with values for the Aptamil-LCP-fed group falling in between.