Proliferation and micromilieu during fractionated irradiation of human FaDu squamous cell carcinoma in nude mice

PURPOSE

Previous functional radiobiological experiments demonstrated a significant acceleration of repopulation after 3 weeks and reoxygenation after 12 days of radiotherapy of FaDu tumours. Owing to the temporal coincidence between repopulation and reoxygenation, it was hypothesized that the improved oxygenation status during fractionated irradiation might be the preceding stimulus for increased proliferation. The study investigated whether these changes in repopulation and re-oxygenation are reflected by histological parameters of proliferation and the tumour micromilieu.

MATERIALS AND METHODS

Human FaDu squamous cell carcinomas in nude mice were irradiated with three to 18 fractions of 3 Gy daily or every second day under normal blood flow and clamp hypoxia. At different time points, tumours were excised and stained for Ki67, BrdUrd, epidermal growth factor receptor (EGFR) and markers of the micromilieu (HOECHST 33342, pimonidazole, ER-MP12).

RESULTS

On average, Ki67 and BrdUrd labelling indices decreased initially and increased again at later times during the course of fractionated radiotherapy. A similar kinetic pattern was found for the staining intensity of the EGFR. The vascular density in the viable tumour area remained constant during the whole course of irradiation, while the perfused fraction of vessels decreased within the first week of irradiation and returned to baseline values after 2 weeks. There was a corresponding increase in perfusion and a decrease in cellular hypoxia.

CONCLUSIONS

The histological results were in surprisingly good agreement with the kinetics of clonogen repopulation and re-oxygenation determined previously using functional assays. The results support that the kinetics of repopulation of FaDu squamous cell carcinoma in response to fractionated irradiation are determined not only by intracellular processes, but also by a complex interaction of proliferation parameters with a changing microenvironment.

Progressive arm weakness and tonic hand spasm from multifocal motor neuropathy in the brachial plexus

A 50-year-old waitress presented with a 10-year history of progressive weakness in her right arm without atrophy and with tonic hand spasms suggesting a central motor disorder. Electromyography, however, disclosed chronic neurogenic changes including fasciculations and atypical cramps. Isolated motor conduction block in the right brachial plexus suggested a variant of multifocal motor neuropathy. Strength recovered and cramps disappeared after intravenous immunoglobulins. Motor neuropathies may thus manifest with features of central motor disorders.

Ultrafractionation in A7 human malignant glioma in nude mice

PURPOSE

Low-dose hyperradiosensitivity (HRS) has been demonstrated in numerous cell lines in vitro, including a number of radioresistant human malignant glioma cell lines such as A7. The aim of our experiment was to show whether HRS can be exploited by using ultrafractionated irradiation (UF) to improve local control of A7 tumours growing in nude mice. Extrapolation of the in vitro results predict a 3.7-fold difference in the efficacy of UF compared with conventional fractionation (CF).

MATERIAL AND METHODS

Subcutaneuously growing A7 tumours were irradiated either with UF (126 fractions in 6 weeks, 0.4 Gy per fraction) or CF (30 fractions in 6 weeks, 1.68 Gy per fraction). The total dose was 50.4 Gy in both experimental arms. Fractionated irradiations were given under ambient conditions and followed by graded top-up doses under clamp hypoxia. Endpoints were tumour growth delay and local tumour control 180 days after the end of treatment.

RESULTS

UF resulted in a significant decrease of tumour growth delay and in a significant increase of the top-up TCD(50) compared with CF (40.0 Gy [95% CI 29; 61 Gy] versus 28.3 Gy [24; 35 Gy], p=0.047).

CONCLUSIONS

Despite a pronounced HRS phenomenon in vitro, UF was significantly less effective than CF in A7 human malignant glioma in nude mice. These results neither disprove the existence of HRS nor do they exclude a possible clinical value of UF. The findings rather indicate that simplistic extrapolation from results obtained after single-dose exposure or few fractions in vitro is not sufficient to predict outcome of UF in vivo and that comprehensive evaluation of novel treatment options in animal models continues to be an essential requirement for clinical translation.

Measurement of plasma corticosterone and fecal glucocorticoid metabolites in the chicken (Gallus domesticus), the great cormorant (Phalacrocorax carbo), and the goshawk (Accipiter gentilis)

A method for the non-invasive measurement of glucocorticoid metabolites in feces of chickens was established and validated. After high-performance liquid chromatography (HPLC) the presence of at least two fecal immunoreactives was demonstrated, one co-eluting with authentic corticosterone, whereas the second substance migrates close to corticosterone sulphate. We investigated the relationship between corticosterone in blood plasma obtained by a vena brachialis catheter and fecal samples in groups of five chickens after an ACTH and a dexamethasone injection to stimulate and to suppress adrenal activity. A control group received a saline injection. After ACTH plasma cortisol concentrations increased 16-fold after 1.5 h to levels between 19 and 38 ng/ml and dropped to pre-treatment levels (1.1-2.5 ng/ml) 4h after stimulation. Dexamethasone did not result in a distinct suppression of adrenocortical activity and plasma corticosterone dropped only slightly below pre-treatment levels. The concentrations in fecal metabolites corresponded to the changes in the levels of biological active hormone in plasma. Fecal peak excretion (105-295 ng/g) was obtained with a delay of approximately 4 h compared to plasma. The profile obtained after ACTH challenge reflected a broader and dampened pattern of glucocorticoid secretion and provided a more integrated measure of adrenal activity. Dexamethasone treatment did not induce a measurable decrease in fecal metabolites and concentrations fluctuated around a mean of 30.0+/-9.9 ng/g, almost identical to those obtained from the saline treatment group (29.4+/-13.9 ng/g). In a separate experiment the effect of an alternative capture method (remote-controlled injection system) was investigated in cormorants. Plasma corticosterone measurements revealed a significantly diminished stress reaction compared to traditional trapping (1.24+/-0.78 vs. 10.9+/-12.1 ng/ml). Investigations whether goshawk nestlings infected with Trichomas gallinae differ in fecal corticosterone metabolite concentrations compared to healthy subjects revealed no significant changes. However, a significant correlation was found between the glucocorticoid metabolite concentrations and the number of nestlings per nest. The demonstration that adrenal activity can be detected by the assay is a prerequisite that ecologically meaningful levels of imposed stress can be validated. Therefore, non-invasive measurements of fecal metabolites are a promising perspective to monitor stress in birds.

Enumeration of probiotic bacilli spores in animal feed: interlaboratory study

Fourteen out of 17 laboratories completed an interlaboratory study comparing 2 pretreatment protocols of feed samples containing authorized probiotic bacilli spores. Both methods used tryptone soy agar for enumeration. Pretreatment A involved preparation of a suspension of the feed sample in 50% ethanol. For pretreatment B, the sample was suspended in peptone salt solution and heated at 80 degrees C for 10 min. Each laboratory analyzed 12 samples (6 per pretreatment), which represented duplicates of a high (10(9) colony-forming units [CFU]/g) and low (10(5) CFU/g) level of bacilli spores or a blank that contained vegetative probiotic bacteria only. For pretreatment A, the repeatability relative standard deviation (RSD(r)) was 2.9% for the low level and 2.5% for the high. The reproducibility relative standard deviation (RSDR) values were 7.8 and 5.9%, respectively. Pretreatment B revealed RSD(r) values of 1.1 and 1.0%, and RSDR values of 5.8 and 3.4%, respectively. The heat treatment (pretreatment B) of feed samples had better precision data, resulted in higher viable bacilli counts, and was more effective in deactivating vegetative background flora. It is therefore recommended for adoption for official control purposes and for CEN and ISO standards.

Oxcarbazepine-induced hyponatremia and the regulation of serum sodium after replacing carbamazepine with oxcarbazepine in children

While severe hyponatremia is reported to be more frequent in adults treated with oxcarbazepine (OXC) than with carbamazepine (CBZ), there is not sufficient data about the incidence of hyponatremia in childhood during treatment with OXC. We evaluated changes in serum electrolyte balance in 75 children with epilepsy before and during treatment with OXC and after replacing carbamazepine (CBZ) therapy with OXC therapy. All patients had normal sodium serum levels at the onset of OXC. During treatment with OXC we found hyponatremia (Na +< 135 mmol/l) without clinical symptoms in 26.6 % of the children (n = 20), sodium levels below 125 mmol/l were observed in 2 children (2.6 %). Clinically relevant hyponatremia occurred in one girl only (1.3 %). In a subgroup of 27 children, in whom CBZ was directly replaced with OXC, hyponatremia without symptoms was found in one child under CBZ (3.7 %) and in six children under OXC (22.2 %). Dosage of OXC, serum levels of the active metabolite of OXC, antiepileptic comedication or patients' age and gender were of no predictive value for the development of hyponatremia. Electrolytes should be measured before establishing OXC and if clinically relevant side effects occur.

[Breech presentation in obstetrics in Germany--an assessment of current status]

Nowadays, the CS seems to be the most favourite way of delivery in case of breech presentation. Our opinion is that the vaginal delivery has no disadvantage for the physical and mental development of the newborns [11, 12]. The outcome depends on the set-up and organisation of each department. The most important condition to reach a good outcome by breech presentation is a well-established practical training of the whole team, a careful risk selection and a well structured perinatal centre. In our opinion the CS is the second choice to deliver a pregnant woman with a breech presentation at term. High CS-rates as well as a increased perinatal morbidity at vaginal breech delivery are a sign for insufficient training of the staff and insufficient organisation in small departments not being perinatal centres. Not the breech presentation is the real risk factor, but the unqualified Obstetrician and the insufficient set-up in the most of OB/Gyn-departments. We have a very high ethic responsibility against young women resultating from our profession. It's our duty to decide and recommend the best way to save the wellbeing of the mother and the unborn child. It's also our duty to avoid surgical manoeuvers resulting from economic reasons. Therefore a complete, sufficient practical training concerning breech delivery technics is absolutely needed. In future the answer of the question: "Delivery of breech presentation--vaginally or through CS?" will depend on, if we will be able to change this politic and professional undesirable trend.

Risk factors for anatomical success and visual outcome in patients undergoing silicone oil removal

PURPOSE

To define risk factors for anatomical success and visual outcome in patients undergoing removal of silicone oil.

METHODS

This retrospective study included patients who had silicone oil removed at this hospital between 1996 and 2000. All were followed for at least six months. Patients with recurrent retinal detachment after silicone oil removal were compared with patients without this complication. We also compared patients whose vision improved or stabilized with patients whose vision deteriorated. Risk factors for anatomical success and visual outcome were identified.

RESULTS

We analysed 94 eyes of 92 patients with silicone oil removal. Nineteen eyes (20%) had recurrent retinal detachment, and in 30 eyes (32%), the vision deteriorated after removal of the oil. Initial vision less than ambulatory vision, initial pathology of giant retinal tears and recurrent retinal detachment, postoperative hypotony and postoperative epiretinal membrane occurred more frequently in eyes with than without recurrent retinal detachment. Pre- and postoperative hypotony, postoperative epiretinal membranes and postoperative recurrent retinal detachment were also more frequent in eyes with deteriorated vision.

CONCLUSIONS

When treating giant retinal tears or recurrent retinal detachments with silicone oil tamponade, surgeons and their patients need to be aware of the higher possibility of unfavorable results, particularly when the initial vision is less than ambulatory vision. The presence of risk factors before and after silicone oil removal should remind surgeons of the higher risk profile of this particular surgery.

High frequency stimulation of the basal ganglia for the treatment of movement disorders: current status and clinical results

High frequency stimulation of the basal ganglia has gained much interest during the last years. Based on the reevaluation of the results of functional neurosurgery for movement disorders from Leksell's group, pallidotomy as lesional procedure was the first functional operation that underwent a renaissance for the treatment of movement disorders. The work by Benabid and Siegfried who carried out thalamic high frequency stimulation to suppress tremor, the knowledge about deep brain stimulation (DBS) for the treatment of chronic pain as well as better understanding in basal ganglia physiology and the development of reliable stimulation hardware led to an increasing number of centers worldwide who currently apply high frequency DBS for different movement disorders. In the present review the current status of DBS for movement disorders is presented and the results with high frequency stimulation targeted at different brain areas are summarized.

CD45 exon 4 point mutation does not confer susceptibility to type 1 diabetes mellitus or Graves' disease

A point mutation in the leukocyte common antigen (CD45, C-->G77, exon 4) was investigated in patients with type 1 diabetes (IDDM), patients with Graves' disease and controls. The distribution did not differ significantly between patients and controls. This CD45 variant does not therefore confer susceptibility to either IDDM or Graves' disease.

[Resistance problems in gastrointestinal infections]

A variety of world-wide resistance problems in bacterial gastrointestinal pathogens have emerged within the last decade. Particularly, antibiotics used to treat salmonella, campylobacter and Helicobacter pylori have lost their efficacy in a high proportion of isolates. Of major clinical significance is the resistance of H. pylori to metronidazole and clarithromycin, of Campylobacter spp. to fluoroquinolones and macrolides and of Salmonella spp. to fluoroquinolones and third generation cephalosporins. Of special concern is the spread of multiresistant isolates. Fortunately, in Clostridium difficile the resistance rate against metronidazole or vancomycin appears to be still low. Numerous investigations provided convincing evidence that the major source of emergence and dissemination of bacterial resistance is the use of antibiotics in food animals. This applies in particular to multiresistant strains of salmonella and campylobacter. A restricted use of antibiotics in the livestock is clearly warranted to control the unlimited development of resistance. The following recommendations should be considered in the care of infections with H. pylori, Campylobacter and Salmonella: 1) Treatment of H. pylori should be restricted to ulcer disease and gastric lymphoma. Eradication is not indicated in asymptomatic patients or patients with gastrointestinal pathologies that are not related to H. pylori. 2) Anti-H. pylori antibiotics should include metronidazole, clarithromycin, amoxicillin or tetracycline in combination of two of them. They should be used in short terms and in the recommended dosages together with proton pump inhibitors. If ulcers relapse after the first eradication, the resistance pattern should be determined. 3) In Campylobacter enterocolitis, antibiotics should be reserved for more severe cases. Resistance testing to exclude quinolone resistance is encouraged if antibiotics are considered. 4) In Salmonella gastroenteritis antibiotics do not significantly improve the course of infection. Their use should thus be restricted to patients which are at risk for disseminated disease including infants, elderly and immunosuppressed persons. 5) Since multiresistant Salmonella are common, resistance testing is highly recommended.

Evidence for a molecular complex consisting of Fyb/SLAP, SLP-76, Nck, VASP and WASP that links the actin cytoskeleton to Fcγ receptor signalling during phagocytosis

Phagocytosis by macrophages and neutrophils involves the spatial and temporal reorganisation of the actin-based cytoskeleton at sites of particle ingestion. Local polymerisation of actin filaments supports the protrusion of pseudopodia that eventually engulf the particle. Here we have investigated in detail the cytoskeletal events initiated upon engagement of Fc receptors in macrophages. Ena/vasodilator-stimulated phosphoprotein (VASP) proteins were recruited to phagosomes forming around opsonised particles in both primary and immortalised macrophages. Not only did the localisation of Ena/VASP proteins coincide, spatially and temporally, with the phagocytosis-induced reorganisation of actin filaments, but their recruitment to the phagocytic cup was required for the remodelling of the actin cytoskeleton, extension of pseudopodia and efficient particle internalisation. We also report that SLP-76, Vav and profilin were recruited to forming phagosomes. Upon induction of phagocytosis, a large molecular complex, consisting in part of Ena/VASP proteins, the Fyn-binding/SLP-76-associated protein (Fyb/SLAP), Src-homology-2 (SH2)-domain-containing leukocyte protein of 76 kDa (SLP-76), Nck, and the Wiskott-Aldrich syndrome protein (WASP), was formed. Our findings suggest that activation of Fcγ receptors triggers two signalling events during phagocytosis: one through Fyb/SLAP that leads to recruitment of VASP and profilin; and another through Nck that promotes the recruitment of WASP. These converge to regulate actin polymerisation, controlling the assembly of actin structures that are essential for the process of phagocytosis.

Dopamine and glutamate induce distinct striatal splice forms of Ania-6, an RNA polymerase II-associated cyclin

Control of neuronal gene expression by drugs or neurotransmitters is a critical step in long-term neural plasticity. Here, we show that a gene induced in the striatum by cocaine or direct dopamine stimulation, ania-6, is a member of a novel family of cyclins with homology to cyclins K/T/H/C. Further, different types of neurotransmitter stimulation cause selective induction of distinct ania-6 isoforms, through alternative splicing. The longer Ania-6 protein colocalizes with nuclear speckles and is associated with key elements of the RNA elongation/processing complex, including the hyperphosphorylated form of RNA polymerase II, the splicing factor SC-35, and the p110 PITSLRE cyclin-dependent kinase. Distinct types of neuronal stimulation may therefore differentially modulate nuclear RNA processing, through altered transcription and splicing of ania-6.

Zyxin is not colocalized with vasodilator-stimulated phosphoprotein (VASP) at lamellipodial tips and exhibits different dynamics to vinculin, paxillin, and VASP in focal adhesions

Actin polymerization is accompanied by the formation of protein complexes that link extracellular signals to sites of actin assembly such as membrane ruffles and focal adhesions. One candidate recently implicated in these processes is the LIM domain protein zyxin, which can bind both Ena/vasodilator-stimulated phosphoprotein (VASP) proteins and the actin filament cross-linking protein alpha-actinin. To characterize the localization and dynamics of zyxin in detail, we generated both monoclonal antibodies and a green fluorescent protein (GFP)-fusion construct. The antibodies colocalized with ectopically expressed GFP-VASP at focal adhesions and along stress fibers, but failed to label lamellipodial and filopodial tips, which also recruit Ena/VASP proteins. Likewise, neither microinjected, fluorescently labeled zyxin antibodies nor ectopically expressed GFP-zyxin were recruited to these latter sites in live cells, whereas both probes incorporated into focal adhesions and stress fibers. Comparing the dynamics of zyxin with that of the focal adhesion protein vinculin revealed that both proteins incorporated simultaneously into newly formed adhesions. However, during spontaneous or induced focal adhesion disassembly, zyxin delocalization preceded that of either vinculin or paxillin. Together, these data identify zyxin as an early target for signals leading to adhesion disassembly, but exclude its role in recruiting Ena/VASP proteins to the tips of lamellipodia and filopodia.

[Disseminated actinic keratoses. Comparison of topical photodynamic therapy with 5-aminolevulinic acid and topical 5% imiquimod cream]

We report on a 75-year-old woman with skin type I suffering for 20 years from multiple actinic keratoses of areas exposed to the sun. The skin of her forearms was treated on one side with imiquimod 5% cream over 4 weeks and on the contralateral side with photodynamic therapy (PDT) using topical 5-aminolevulinic acid (ALA). Both sides showed good clinical response after 3-months follow-up, suggesting that these modalities can be effectively used for treating widespread multiple actinic keratoses.

Hemangiosarcoma of the bone. Problems arising from the heterogeneity of malignant vascular tumors of the bone

BACKGROUND

Hemangioendothelioma of the bone is a rare vasoformative tumor of the bone with an intermediately aggressive nature. The tumor is said to have a long clinical course depending on the sites involved. Diagnosis is particularly difficult since vascular tumors of the bone often present heterogeneous differentiation.

CASE REPORT

We report on a 65-year-old female patient who had been diagnosed with an epitheloid hemangioendothelioma of the iliac bone and who underwent wide local excision. Although the initial biopsy specimens had clearly shown an epitheloid hemangioendothelioma, the final pathological analysis revealed a heterogeneous tumor, partially with some characteristics of an epitheloid hemangiosarcoma. The patient subsequently developed pulmonary metastasis, received a multimodality treatment, but died 14 months after the initial diagnosis from pulmonary insufficiency due to pleural sarcomatosis.

CONCLUSION

Hemangioendothelioma of the bone needs to be discussed as a differential diagnosis of osteolytic lesions. Our case stresses the importance of multimodality treatment in centers for cancer treatment. Histopathologic evaluation is essential in the diagnosis of epitheloid hemangioendothelioma. It is particularly difficult due to the heterogeneous differentiation of vasoformative tumors of the bone.

Repopulation of FaDu human squamous cell carcinoma during fractionated radiotherapy correlates with reoxygenation

PURPOSE

FaDu human squamous cell carcinoma (FaDu-hSCC) showed a clear-cut time factor during fractionated radiotherapy (RT) under ambient blood flow. It remained unclear whether this is caused solely by proliferation or if radioresistance resulting from increasing hypoxia contributed to this phenomenon. To address this question, repopulation of clonogenic FaDu cells during fractionated RT under clamp hypoxia was determined by local tumor control assays, and compared to the results after irradiation with the same regimen under ambient blood flow.

METHODS AND MATERIALS

FaDu-hSCC was transplanted into the right hind leg of NMRI nu/nu mice. In the first set of experiments, irradiation was performed under clamp hypoxia. After increasing numbers of 3 Gy fractions (time intervals 24 h or 48 h), graded top-up doses were given to determine the TCD(50) (dose required to control 50% of the tumors). In the second set of experiments, all 3 Gy fractions were applied under ambient conditions, but as in the previous experiments the graded top-up doses were given under clamp hypoxia. A total of 26 TCD(50) assays were performed and analyzed using maximum likelihood techniques.

RESULTS

With increasing numbers of daily fractions, the top-up TCD(50) under clamp hypoxia decreased from 39.4 Gy [95% CI 36, 42] after single dose to 19.8 Gy [15, 24] after 18 fractions in 18 days and to 37.8 Gy [31, 44] after 18 fractions in 36 days. The results were consistent with biphasic repopulation, with a switch to rapid repopulation after about 22 days [13, 30]. The clonogen doubling time (T(clon)) decreased from 9.8 days [0, 21] in the beginning of RT to 3.4 days after 22 days. Under ambient blood flow the top-up TCD(50) decreased from 37.6 Gy [34, 40] after single dose irradiation to 0 Gy [0, 1] after 18 fractions in 18 days and 22.4 Gy [18, 27] after 18 fractions in 36 days. Similar to results from irradiations under clamp hypoxia, the ambient data were consistent with a biphasic course of clonogen inactivation. Comparison of both data sets revealed significant reoxygenation after 12 fractions.

CONCLUSIONS

Our data are most consistent with a biphasic course of clonogen repopulation during fractionated RT of FaDu-hSCC under clamp hypoxia with a switch in T(clon) after about 22 days of treatment ("dog-leg"). A similar biphasic course of cell repopulation was observed under ambient conditions. The temporal coincidence between repopulation and reoxygenation suggests that the latter might be the stimulus for proliferation in FaDu tumors.