Spermidine/Spermine N1-Acetyltransferase 1 (SAT1)-A Potential Gene Target for Selective Sensitization of Glioblastoma Cells Using an Ionizable Lipid Nanoparticle to Deliver siRNA

Spermidine/spermine N1-acetyltransferase 1 (SAT1) responsible for cell polyamine catabolism is overexpressed in glioblastoma multiforme (GB). Its role in tumor survival and promoting resistance towards radiation therapy has made it an interesting target for therapy. In this study, we prepared a lipid nanoparticle-based siRNA delivery system (LNP-siSAT1) to selectively knockdown (KD) SAT1 enzyme in a human glioblastoma cell line. The LNP-siSAT1 containing ionizable DODAP lipid was prepared following a microfluidics mixing method and the resulting nanoparticles had a hydrodynamic size of around 80 nm and a neutral surface charge. The LNP-siSAT1 effectively knocked down the SAT1 expression in U251, LN229, and 42MGBA GB cells, and other brain-relevant endothelial (hCMEC/D3), astrocyte (HA) and macrophage (ANA-1) cells at the mRNA and protein levels. SAT1 KD in U251 cells resulted in a 40% loss in cell viability. Furthermore, SAT1 KD in U251, LN229 and 42MGBA cells sensitized them towards radiation and chemotherapy treatments. In contrast, despite similar SAT1 KD in other brain-relevant cells no significant effect on cytotoxic response, either alone or in combination, was observed. A major roadblock for brain therapeutics is their ability to cross the highly restrictive blood-brain barrier (BBB) presented by the brain microcapillary endothelial cells. Here, we used the BBB circumventing approach to enhance the delivery of LNP-siSAT1 across a BBB cell culture model. A cadherin binding peptide (ADTC5) was used to transiently open the BBB tight junctions to promote paracellular diffusion of LNP-siSAT1. These results suggest LNP-siSAT1 may provide a safe and effective method for reducing SAT1 and sensitizing GB cells to radiation and chemotherapeutic agents.

Dermal lesions after post mortem petrol-exposure

The effect of post mortem contact of the skin with petrol was investigated in 18 corpses with exposure times between 10 min and 24 h. The earliest onset of skin changes was observed within 2 h of exposure. They consisted of swelling and wrinkling with detachment of the upper layers of the skin (positive Nikolski's sign). Histologically the lesions appeared as non-vital acantholyses located in the prickle-cell layer with formation of intra-epidermal bullae. An influence of age and sex could be excluded, the earlier onset of lesions at 22 degrees C than at 4 degrees C was not statistically significant. These findings prove that post mortem petrol exposure may lead to dermal lesions.

Laryngohyoid fractures after agonal falls: Not always a certain sign of strangulation

Haemorrhagic fractures of the thyroid cartilage and hyoid bone are frequently observed in cases of strangulation and often regarded as evidence for an assault against the neck. In contrast, two cases of laryngohyoid fractures after agonal falls in prone position are presented to draw attention to alternative causes of these injuries with special regard to practical medicolegal casework. A 45-year-old man collapsed at a fairground and died after unsuccessful resuscitation. He showed excoriations at his elbows and right knee, a crush injury at the mentum and his mandibular front teeth were knocked out. The upper parts of the chest and the head showed blue discolouration as a marked sign of congestion due to heart failure. The right coronary artery (RCA) was completely obturated by a 5 cm long post-stenotic thrombus with subsequent myocardial infarction of the lateral part of the left ventricle. Both superior horns of the thyroid cartilage were fractured with surrounding haemorrhage, the skin and muscles of the neck uninjured. In the second case, a 63-year-old woman with a mobility handicap had fallen from a 2m high lifting platform and was found in prone position with her wheelchair on her. Resuscitation efforts were not successful. Autopsy showed signs of blunt external force against head, neck, chest and limbs. Examination of the neck revealed haemorrhage of the right sternocleidomastoid muscle, both superior horns of the thyroid cartilage were fractured, as well as the hyoid bone, with slight haemorrhage of the surrounding soft tissue and mucosa. On the same level, the fifth intervertebral disk was ruptured, without any injury of the spinal cord. These cases demonstrate that laryngohyoid fractures should not be overestimated as unequivocal indication of neck compression and may well be caused by falls, even at ground level.

Multislice CT of the pelvis: dose reduction with regard to image quality using 16-row CT

To optimize examination protocols of 16-row multi-detector CT (MDCT) of pelvis for dose reduction with regard to image quality. MDCT of pelvis was performed on 12 cadaver specimens with stepwise reduction of tube current from 160 mA (113, 80, 56, 40, 28) to 20 mA at 120 kV. Scan parameters were 16 x 1.5 mm collimation. Reconstructions of axial and coronal images were used for evaluation of cortex, trabeculum, image quality, image noise, acetabulum and iliosacral (ISJ) joints. After data were blinded, evaluation of images was done by three radiologists according to 5-point Likert scale. Accuracy of the observers in sorting films according to dose reduction was determined with kappa coefficient. Mean values of image evaluation were determined. Pronounced deterioration of image quality for all criteria was observed between 80 and 28 mA. Adequate image quality was obtained at 40 mA [effective dose (E): 2.2 mSv, CTDI(w): 2.8 mGy] for criterion detailed definition of acetabulum and ISJ and at 80 mA (E: 4.4 mSv, CTDI(w): 5.6 mGy) for remaining criteria. Moderate agreement was observed between the three observers (kappa coefficient: 0.31). All observers were excellent in arranging images according to decreasing dose. Using 16-row MDCT image quality of pelvis is acceptable at 80 mA and 120 kV. This translates into a dose reduction of 33% of average value of the nationwide survey of the German Roentgen Society (1999) for this type of examination.

Vorzeichen und Ursachen des plötzlichen Todes im Zusammenhang mit sportlicher Betätigung

BACKGROUND

This study provides an overview on presymptoms and causes of sport-related death and suggests preventive measures.

METHODS

29 436 autopsies of the Centre of Legal Medicine at the University of Frankfurt/Main from 1972 to 2001 were analysed and compared with a control group.

RESULTS

96 men (95 %, average age 53.3 years) and 5 women (5 %, average age 36.4 years) were involved in 101 fatalities connected with sports (0.34 % of all autopsies). 78 athletes (77.2 %) died during, 20 (19.8 %) immediately after sport activities. Immediately before death 18 of 50 persons concerned were free of symptoms, twelve complained of nausea and vomiting, seven of vertigo, five of weakness, four of epigastric pain and dyspnoea, three exhibited angina pectoris symptoms. The day before death 7 of 25 athletes had symptoms like angina pectoris, nausea, backache and palpitation. 84 fatalities (83.2 %) were due to coronary heart disease. Seven were due to myocarditis (6.9 %), in four cases (26.7 %) among athletes younger than 36. Among children and adolescents (n = 4) myocarditis, cardiomyopathy and in two cases a valvular defect of the heart were the cause of death. In comparison to controls death in elder athletes due to coronary heart disease and myocardial infarction was high significantly more common and athletes died significantly younger.

CONCLUSIONS

Further prospective investigations are needed to provide strategies for prevention.

Optimization of vaccine production for animal health

Vaccines on the basis of mammalian cell cultures are of major importance for human and animal health. Therefore efforts are undertaken for the improved production of more effective vaccines. Of course, the main purpose of all these approaches is to save lives and improve the quality of life for human beings. However, there is also some remarkable effort in the food industry and the associated animal production, especially in the case of some Flaviviridal viruses (BVD), where > 80% of all cattle herds are found to be infected. These viruses can cause tremendous economic losses of calfs and embryos (Ames, 1990). Because of these facts, there is a continuous endeavour for improving the manufacturing of therapeutics or preventing agents such as vaccines for the treatment of cattle. The competitive economic situation and the specific market demands still require effective and high yield production methods, especially in the case of one of the most widespread viral diseases in cattle like BVD (Ames, 1990). We have succeeded in establishing an improved method for the production of BVD on the basis of a continuous fermentation mode, that consist of modifications of the corresponding process and media improvements.

[Endotoxin in blood plasma of patients after trauma]

Depending on the severity of the injury, high endotoxin levels may be found in patients with lung contusion but only slightly increased levels in patients with skull and brain trauma. This difference is highly significant. Patients with multiple injuries and fractures of the extremities as the main diagnosis and with a combination of injuries show a moderate increase in endoxin level on the day of admission. There is no relationship between the injury severity and endotoxemia.

Primary penile reanastomosis

Two cases of penile amputation with the techniques of reanastomosis are presented. Other techniques are briefly reviewed. A microvascular anastomosis of the dorsal vessels or nerves does not appear to be necessary, although gentle thorough reconstruction of the urethra and corpora obviously is.