Effect of LIBS-Induced Alteration on Subsequent Raman Analysis of Iron Sulfides

Mineral alteration is a possible side effect of spectroscopic techniques involving laser ablation, such as laser-induced breakdown spectroscopy (LIBS), and is related to the interaction of the generated plasma and ablated material with samples, dust, or ambient atmosphere. Therefore, it is essential to understand these interactions for analytical techniques involving laser ablation, especially for space research. In this combined LIBS-Raman analytical study, pyrite (FeS₂) and pyrrhotite (Fe_1-x S) samples have been consecutively measured with LIBS and Raman spectroscopy, under three different atmospheric conditions: ∼10^-4 mbar (atmosphereless body), ∼7 mbar, and Martian atmospheric composition (Martian surface conditions), and 1 bar and Martian atmospheric composition. Furthermore, a dust layer was simulated using ZnO powder in a separate test and applied to pyrite under Martian atmospheric conditions. In all cases, Raman spectra were obscured after the use of LIBS in the area of and around the formed crater. Additional Raman transitions were detected, associated with sulfur (pyrite, 7.0 mbar and 1.0 bar), polysulfides (all conditions), and magnetite (both minerals, 1.0 bar). Magnetite and polysulfides formed a thin film of up to 350-420 and 70-400 nm in the outer part of the LIBS crater, respectively. The ZnO-dust test led to the removal of the dust layer, with a similar alteration to the nondust pyrite test at 7.0 mbar. The tests indicate that recombination with the CO₂-rich atmosphere is significant at least for pressures from 1.0 bar and that plasma-dust interaction is insignificant. The formation of sulfur and polysulfides indicates fractionation and possible loss of volatile elements caused by the heat of the LIBS laser. This should be taken into account when interpreting combined LIBS-Raman analyses of minerals containing volatile elements on planetary surfaces.

Strategic considerations for the sustainable remediation of nuclear installations

Nuclear sites around the world are being decommissioned and remedial actions are being undertaken to enable the sites or parts of the sites to be reused. Although this is relatively straightforward for most sites, experience has suggested that preventative action is needed to minimise the impact of remediation activities on the environment and the potential burden to future generations. Removing all contamination in order to make a site suitable for any use generates waste and has associated environmental, social and economic detriments and benefits that should be taken into account. Recent experience of OECD Nuclear Energy Agency (NEA) member countries in the remediation of contaminated land, predominantly contaminated soil and groundwater, on nuclear sites during decommissioning has been assessed by an NEA task group. The experience was used to identify strategic considerations for nuclear site remediation, to consider the application of sustainability principles to nuclear site remediation, to describe good practice, and to make recommendations for further research and development. The key aspects that were identified were that 1) site remediation should be sustainable by resulting in an overall net benefit; and 2) an adaptive approach is essential in order to take into account the inherent uncertainty associated with the decommissioning and site remediation timescales. A report describing the findings was published by OECD/NEA in 2016. The conclusions provide insights to decision makers, regulators, implementers and stakeholders involved in nuclear site decommissioning so that they can achieve sustainable remediation of nuclear sites, now and in the future.

Graves' disease and radioiodine therapy

Aim: This study was performed to analyse the impact of the choice of antithyroid drugs (ATD) on the outcome of ablative radioiodine therapy (RIT) in patients with Graves' disease. Patients, material, methods: A total of 571 consecutive patients were observed for 12 months after RIT between July 2001 and June 2004. Inclusion criteria were the confirmed diagnosis of Graves' disease, compensation of hyperthyroidism and withdrawal of ATD two days before preliminary radioiodine-testing and RIT. The intended dose of 250 Gy was calculated from the results of the radioiodine test and the therapeutically achieved dose was measured by serial uptake measurements. The end-point measure was thyroid function 12 months after RIT; success was defined as elimination of hyperthyroidism. The pretreatment ATD was retrospectively correlated with the results achieved. Results: Relief from hyperthyroidism was achieved in 96 % of patients. 472 patients were treated with carbimazole or methimazole (CMI) and 61 with propylthiouracil (PTU). 38 patients had no thyrostatic drugs (ND) prior to RIT. The success rate was equal in all groups (CMI 451/472; PTU 61/61; ND 37/38; p=0.22). Conclusion: Thyrostatic treatment with PTU achieves excellent results in ablative RIT, using an accurate dosimetric approach with an achieved post-therapeutic dose of more than 200 Gy.

Graves' disease and radioiodine therapy

Aim: This study was performed to determine the results of ablative radioiodine therapy (RIT) when the achieved dose in the thyroid was above 200 Gy and to characterize predictive factors for treatment outcome. Patients, methods: A total of 571 consecutive patients were observed for 12 months between July 2001 and June 2004. Inclusion criteria were a confirmed diagnosis Graves' disease, compensation of hyperthyroidism and withdrawal of antithyroid drugs two days before preliminary radioiodine-testing and RIT. The intended dose was 250 Gy and the therapeutically achieved dose was calculated from serial uptake measurements. The end-point measure was thyroid function 12 months after RIT; success was defined as elimination of hyperthyroidism. The relation between success rate and the achieved dose, thyroid volume, age and sex of patients, TSH- and TRAb-values and presence of ophthalmopathy was analysed. Results: Relief from hyperthyroidism was achieved in 96% of patients who received more than 200 Gy, even for thyroid volumes >40 ml. The success of ablative RIT was not influenced by age or sex of patients, or by TSH- or TRAb values or concomitant ophthalmopathy. The mean achieved dose in the thyroid was 298 Gy with a standard deviation of 74.6 Gy. Conclusion: To achieve a dose of over 200 Gy with the above standard deviation, we recommend calculating an intended dose of 250 Gy and using a dosimetric approach with early and late uptake values in the radioiodine test, to allow early therapeutic intervention should the posttherapeutic thyroid dose fall unexpectedly below 200 Gy.

Abstract P2-09-22: Long-term psychosocial consequences and counsellees' satisfaction after genetic counselling for hereditary breast- and ovarian cancer - A patient reported outcome study

Background: Genetic counselling and testing (GCT) for hereditary breast and ovarian cancer (BOC) has become a standard option in BOC care in Europe allowing for prognostic information on the individual risk for disease onset/ relapse as well as on treatment options comprising prophylactic surgery or surveillance programs. However, data on the psychosocial long-term consequences is limited, especially in high-risk counsellees opting against genetic testing. We aimed at investigating the long-term psychosocial consequences of GCT for hereditary BOC in all counsellees irrespective of their decision after counselling.

Patients and Methods: Counsellees for BOC with and without a previous disease who had undergone genetic counselling at Innsbruck Medical University between 2011 and 2014 were asked to participate in a cross-sectional Patient Reported Outcome (PRO) assessment (incl. Multidimensional Impact of Cancer Risk Assessment, Genetic counseling satisfaction scale, Satisfaction with Decision Scale, Breast Cancer Heredity Knowledge Scale, Hospital Anxiety and Depression Scale/ HADS, Short Form 12 Health Survey, Cancer Worry Scale/ CWS) targeting on psychological distress, cancer worry, patient knowledge and patient satisfaction with genetic counselling and decisions by means of an anonymous mail survey. Subsequent decisions for vs. against genetic testing and if eligible, for surveillance vs. prophylactic surgery were also assessed. A reference sample of BC survivors was recruited at the outpatient unit.

Results: An overall sample of 137 counselees was included in the analysis (67.9% decided to undergo genetic testing for a HCPS, 22.6% decided not to be tested, 9.5% were still uncertain about their decision). 22.6% of counsellees experienced clinically relevant levels of anxiety and 9.8% scored above the cut-off for clinically relevant depression according to the HADS. Mean CWS score was 11 (SD 3.6, 3-24). Counsellees did not differ from breast cancer survivors regarding anxiety and depression according to the HADS (depression: p<0.5). Mean patient satisfaction with decisions amounted to 25.4 (SD 5.78, min. 4 to max. 30); a mean satisfaction with counselling of 25 (5.4) was observed. Less overall satisfaction with genetic counselling (β=0.445, t=5.552, p=0.000) and lower certainty about decision for/ against genetic testing after counselling (β=-0.169, t=-2.105, p=0.037) were highly predictive for lower long-term patient satisfaction with decisions.

Conclusion: Our results indicate that genetic counselling for BOC has no overall deleterious psychosocial consequences in long-term. Levels of depression and anxiety were comparable to those of the general population, while distress levels did not differ from those of breast cancer survivors without a hereditary BOC predisposition. The overall satisfaction with counselling as well as the certainty with decisions on testing and related medical interventions are highly predictive for the long-term satisfaction with decisions. Hence, genetic counselling should focus on supporting counsellees in forming clear decisions and include identifying counsellees with increased cared needs in this regard by means of PRO assessment in follow-up.

Citation Format: Hubalek M, Sztankay M, Meraner V, Martini C, Sperner-Unterweger B, Weber I, Morscher R, Zschocke J, Egle D, Dünser M, Oberguggenberger A. Long-term psychosocial consequences and counsellees' satisfaction after genetic counselling for hereditary breast- and ovarian cancer - A patient reported outcome study. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P2-09-22.

[Usefulness of a real-time quantitative polymerase-chain reaction (PCR) assay for the diagnosis of congenital and postnatal cytomegalovirus infection]

INTRODUCTION

Cytomegalovirus (CMV) is the main virus causing congenital and postnatal infections in the pediatric population. The aim of this study is to evaluate the usefulness of a quantitative real-time PCR in the diagnosis of these infections using urine as a single sample.

PATIENTS AND METHODS

We studied all the urine samples of newborns (< 7 days) with suspected congenital infection, and urine of patients with suspected postnatal infection (urine negative at birth). Urines were simultaneously studied by cell culture, qualitative PCR (PCRc), and quantitative real-time PCR (PCRq).

RESULTS

We analyzed 332 urine samples (270 to rule out congenital infection and 62 postnatal infections). Of the first, 22 were positive in the PCRq, 19 in the PCRc, and 17 in the culture. PCRq had a sensitivity of 100%, on comparing the culture with the rest of the techniques. Using the PCRq as a reference method, culture had a sensitivity of 77.2%, and PCRc 86.3%. In cases of postnatal infection, PCRq detected 16 positive urines, the PCRq 12, and the cell culture 10. The urines showed viral loads ranging from 2,178 to 116,641 copies/ml.

CONCLUSIONS

The genomic amplification technique PCRq in real time was more sensitive than the other techniques evaluated. This technique should be considered as a reference (gold standard), leaving the cell culture as a second diagnostic level. The low cost and the automation of PCRq would enable the screening for CMV infection in large neonatal and postnatal populations.

SAP Speaks PDDL: Exploiting a Software-Engineering Model for Planning in Business Process Management

Planning is concerned with the automated solution of action sequencing problems described in declarative languages giving the action preconditions and effects. One important application area for such technology is the creation of new processes in Business Process Management (BPM), which is essential in an ever more dynamic business environment. A major obstacle for the application of Planning in this area lies in the modeling. Obtaining a suitable model to plan with -- ideally a description in PDDL, the most commonly used planning language -- is often prohibitively complicated and/or costly. Our core observation in this work is that this problem can be ameliorated by leveraging synergies with model-based software development. Our application at SAP, one of the leading vendors of enterprise software, demonstrates that even one-to-one model re-use is possible. The model in question is called Status and Action Management (SAM). It describes the behavior of Business Objects (BO), i.e., large-scale data structures, at a level of abstraction corresponding to the language of business experts. SAM covers more than 400 kinds of BOs, each of which is described in terms of a set of status variables and how their values are required for, and affected by, processing steps (actions) that are atomic from a business perspective. SAM was developed by SAP as part of a major model-based software engineering effort. We show herein that one can use this same model for planning, thus obtaining a BPM planning application that incurs no modeling overhead at all. We compile SAM into a variant of PDDL, and adapt an off-the-shelf planner to solve this kind of problem. Thanks to the resulting technology, business experts may create new processes simply by specifying the desired behavior in terms of status variable value changes: effectively, by describing the process in their own language.

Keyhole approach for repair of congenital duodenal obstruction

BACKGROUND

We report on our experience of repair of congenital duodenal obstruction using a circumumbilical incision. The aim of this report is to describe how a Bianchi approach provides a safe and invisible alternative to transverse abdominal incision for the repair of duodenal atresia.

METHODS

Between January 2005 and December 2009, we treated 13 cases with congenital duodenal obstruction using a circumumbilical incision (Group I) and 14 cases with this condition repaired using a standard transverse right upper abdominal incision (Group II). Surgical procedures included a diamond-shaped duodenoduodenostomy as originally described by Kimura and standard duodenal web excision. The circumumbilical incision utilized at our institution is a classic Bianchi procedure. The 2 groups were compared with regard to patient demographics, operative reports and postoperative outcomes.

RESULTS

There were no differences in preoperative parameters such as gestational age, age at surgery, or body weight at operation between the 2 groups. The circumumbilical cohort and transverse incision cohort had similar rates of congenital anomalies (61.54% vs. 64.29%), Kimura diamond-shaped anastomosis (61.54% vs. 64.29%) with only a slight female predominance in Group I. The mean operating time in Group I was 65.0 min while mean duration of the operation in Group II was 64.64 min. The difference between groups was statistically not significant (p>0.05). The mean time to full enteral feeding for patients with an umbilical incision was significantly shorter (p<0.0001) compared to patients with a standard incision (6.92 days vs. 11.86 days). Mean postoperative hospital stay was longer for patients in Group II (19.71 days vs. 12.38 days; p<0.0001). The postoperative course was uneventful for all patients. There were no intra- or postoperative complications.

CONCLUSION

We report on a first series comparing umbilical and transverse right upper abdominal incision for the treatment of congenital duodenal obstruction. Our results suggest that an umbilical incision offers all the benefits of a minimal access approach, including earlier feeding and shorter times to discharge. We consider our approach an intermediate step, with laparoscopy likely to become the "gold standard" for the treatment of congenital duodenal obstruction.

Graves' disease and radioiodine therapy. Is success of ablation dependent on the choice of thyreostatic medication?

AIM

This study was performed to analyse the impact of the choice of antithyroid drugs (ATD) on the outcome of ablative radioiodine therapy (RIT) in patients with Graves' disease.

PATIENTS, MATERIAL, METHODS

A total of 571 consecutive patients were observed for 12 months after RIT between July 2001 and June 2004. Inclusion criteria were the confirmed diagnosis of Graves' disease, compensation of hyperthyroidism and withdrawal of ATD two days before preliminary radioiodine-testing and RIT. The intended dose of 250 Gy was calculated from the results of the radioiodine test and the therapeutically achieved dose was measured by serial uptake measurements. The end-point measure was thyroid function 12 months after RIT; success was defined as elimination of hyperthyroidism. The pretreatment ATD was retrospectively correlated with the results achieved.

RESULTS

Relief from hyperthyroidism was achieved in 96% of patients. 472 patients were treated with carbimazole or methimazole (CMI) and 61 with propylthiouracil (PTU). 38 patients had no thyrostatic drugs (ND) prior to RIT. The success rate was equal in all groups (CMI 451/472; PTU 61/61; ND 37/38; p = 0.22).

CONCLUSION

Thyrostatic treatment with PTU achieves excellent results in ablative RIT, using an accurate dosimetric approach with an achieved post-therapeutic dose of more than 200 Gy.

Graves' disease and radioiodine therapy. Is success of ablation dependent on the achieved dose above 200 Gy?

AIM

This study was performed to determine the results of ablative radioiodine therapy (RIT) when the achieved dose in the thyroid was above 200 Gy and to characterize predictive factors for treatment outcome.

PATIENTS, METHODS

A total of 571 consecutive patients were observed for 12 months between July 2001 and June 2004. Inclusion criteria were a confirmed diagnosis Graves' disease, compensation of hyperthyroidism and withdrawal of antithyroid drugs two days before preliminary radioiodine-testing and RIT. The intended dose was 250 Gy and the therapeutically achieved dose was calculated from serial uptake measurements. The end-point measure was thyroid function 12 months after RIT; success was defined as elimination of hyperthyroidism. The relation between success rate and the achieved dose, thyroid volume, age and sex of patients, TSH- and TRAb-values and presence of ophthalmopathy was analysed.

RESULTS

Relief from hyperthyroidism was achieved in 96% of patients who received more than 200 Gy, even for thyroid volumes >40 ml. The success of ablative RIT was not influenced by age or sex of patients, or by TSH- or TRAb values or concomitant ophthalmopathy. The mean achieved dose in the thyroid was 298 Gy with a standard deviation of 74.6 Gy.

CONCLUSION

To achieve a dose of over 200 Gy with the above standard deviation, we recommend calculating an intended dose of 250 Gy and using a dosimetric approach with early and late uptake values in the radioiodine test, to allow early therapeutic intervention should the posttherapeutic thyroid dose fall unexpectedly below 200 Gy.

Prevalence of cerebral microhemorrhages in amateur boxers as detected by 3T MR imaging

BACKGROUND AND PURPOSE

The evidence for traumatic brain injury in amateur boxers is controversial. Hypothetically, sudden acceleration of the head due to the impact of the blow during the boxing fight might result in diffuse axonal injury or contusion. We wanted to determine whether cerebral microhemorrhages occur more often in amateur boxers than in nonboxers.

MATERIALS AND METHODS

In 42 male, classical amateur boxers and in 37 healthy, nonboxing male volunteers we performed cranial MR imaging at 3T. The study protocol included a transverse dual spin-echo MR imaging sequence, a 3D sagittal magnetization-prepared rapid acquisition of gradient echo sequence, a coronal T2*-weighted sequence, and an axial time-of-flight MR angiography sequence. MR imaging data were made anonymous before 2 neuroradiologists independently evaluated the images. In addition, the following risk factors were assessed: total numbers of fights and knockouts, weight division, and duration of boxing. We compared the group proportions of microhemorrhages with Fisher test of exact probability.

RESULTS

There was a statistically higher prevalence of cerebral microhemorrhages in the group of boxers (3 of 42; 7.1%) than in nonboxing persons (0 of 37; 0%). This difference was not statistically significant, however (P = .2479; Fisher exact test).

CONCLUSION

Although we detected more microhemorrhages in amateur boxers than in nonboxing persons, this difference did not prove to be significant.

The effects of inhalation anaesthetics on common clinical pathology parameters in laboratory rats

Effects of common anaesthetics such as ether, methoxyflurane, isoflurane, carbon dioxide (at 100%, 80% or 60% admixed with O(2)) on toxicity and clinical pathology parameters in rats were investigated. Ether, methoxyflurane and 100% CO(2) induced toxicity in some animals. Erythrocyte, haemoglobin and haematocrit were reduced in females by 100% CO(2), methoxyflurane and isoflurane. Glucose was increased by 60% CO(2), 80% CO(2), ether, isoflurane and methoxyflurane in males. Chloride was reduced by isoflurane and all CO(2) concentrations in females. Serum proteins were reduced by isoflurane and methoxyflurane. Sodium, inorganic phosphate, calcium and magnesium were reduced by methoxyflurane and isoflurane, but increased by all CO(2) concentrations. Potassium was reduced by ether, methoxyflurane or isoflurane. Triiodothyronine and thyroxine were reduced by all anaesthetics. Prolactin was reduced by methoxyflurane, but raised by ether and isoflurane. Erythrocyte cholinesterase (E-ChE) activity is markedly reduced (20-40%) after anaesthesia with all CO(2) concentrations in both sexes. E-ChE was unaffected by ether, methoxyflurane, or isoflurane. Serum and brain cholinesterase activities were not affected. E-ChE inhibition correlated with decreased blood pH, suggesting that this was caused by acidosis. This is of practical relevance in the risk assessment of cholinesterase inhibitors.

CONCLUSIONS

Clinical pathology data were affected by all anaesthetics. CO(2)/O(2) (80%/20%) and isoflurane are the most suitable anaesthetics. If E-ChE activity is to be determined, isoflurane is the anaesthetic of choice.

The Crystallization Age of Eucrite Zircon

Eucrites are a group of meteorites that represent the first planetary igneous activity following metal-silicate differentiation on an early planetesimal, similar to Asteroid 4 Vesta, and, thus, help date geophysical processes occurring on such bodies in the early solar system. Using the short-lived radionuclide (182)Hf as a relative chronometer, we demonstrate that eucrite zircon crystallized quickly within 6.8 million years of metal-silicate differentiation. This implies that mantle differentiation on the eucrite parent body occurred during a period when internal heat from the decay of (26)Al and (60)Fe was still available. Later metamorphism of eucrites took place at least 8.9 million years after the zircons crystallized and was likely caused by heating from impacts, or by burial under hot material excavated by impacts, rather than from lava flows. Thus, the timing of eucrite formation and of mantle differentiation is constrained.

Effects of Varying Dietary Forage Particle Size in Two Concentrate Levels on Chewing Activity, Ruminal Mat Characteristics, and Passage in Dairy Cows

The objective of this study was to investigate the effects of varying dietary forage particle size on chewing activity, ruminal mat characteristics, passage, and in situ ruminal and total tract digestion in dairy cows at a low- and high-concentrate inclusion. The experiment was designed as a 4 x 4 Latin square with a 2 x 2 factorial arrangement of treatments. Four ruminally cannulated late-lactating dairy cows were restrictively fed (17 kg of dry matter/d), in four 23-d periods, 1 of 4 different diets varying in the theoretical particle size (6 and 30 mm) of hay (56.6% NDF of dry matter) and in the levels (approximately 20 and 60%, dry matter basis) of a cereal-based concentrate. Ingredients of the ration were offered separately to the cows; dietary hay and low-level concentrate were offered twice daily at 0800 and 1600 h, whereas concentrate of the high-level treatment was offered in 4 meals a day at 0800, 1200, 1600, and 1900 h. This study showed that altering the forage particle size from 6 to 30 mm in a low-concentrate diet significantly increased the rumination time and ruminal mat consistency without affecting ruminal fermentation and passage. Further, particle breakdown and proportion of mat in the rumen increased, and in situ hay dry matter degradability improved, which in turn indicated a higher capacity of ruminal digesta to degrade fiber. On the other hand, increasing the forage particle size in a diet containing a high amount of concentrate increased the proportion of dry matter retained on a 1.18-mm screen from 37.5 to 42.0% and extended the rumination time by 100 min/d, as well as increasing the ruminal mat consistency. However, ruminal particle breakdown, short-term ruminal pH, fibrolytic capacity of the digesta, and proportion of mat in the rumen decreased. This was also reflected in a higher bailable liquid pool, increased fractional passage rate of solid digesta from the reticulorumen, and increased retention time in the hindgut, which in turn indicated a shift of fiber digestion from the rumen to the lower digestive tract. This study showed that the response of chewing or ruminating activity alone seemed to be insufficient to assess the dietary physical effectiveness or fiber adequacy in limit-fed dairy cows when high-concentrate diets were fed separately. Based on the results of this study, we concluded that inclusion of coarsely chopped hay in the high-concentrate diet did not appear to further improve rumen conditions and digestion when the rations were formulated to exceed the fiber requirements in limit-fed dairy cows.

A search for a mutation of the Aiolos phosphorylation domain in lymphocytes from patients with leukemia

We examined whether phosphorylation of Aiolos in primary human lymphocytes is part of the malignant transformation in leukemia. By analyzing mutations at a restriction site we show here that impairment of Aiolos activity in human leukemia is not based on deficient phosphorylation as had been demonstrated in experiments in vitro.

Mineralogy and petrology of comet 81P/Wild 2 nucleus samples

The bulk of the comet 81P/Wild 2 (hereafter Wild 2) samples returned to Earth by the Stardust spacecraft appear to be weakly constructed mixtures of nanometer-scale grains, with occasional much larger (over 1 micrometer) ferromagnesian silicates, Fe-Ni sulfides, Fe-Ni metal, and accessory phases. The very wide range of olivine and low-Ca pyroxene compositions in comet Wild 2 requires a wide range of formation conditions, probably reflecting very different formation locations in the protoplanetary disk. The restricted compositional ranges of Fe-Ni sulfides, the wide range for silicates, and the absence of hydrous phases indicate that comet Wild 2 experienced little or no aqueous alteration. Less abundant Wild 2 materials include a refractory particle, whose presence appears to require radial transport in the early protoplanetary disk.

Comet 81P/Wild 2 Under a Microscope

The Stardust spacecraft collected thousands of particles from comet 81P/Wild 2 and returned them to Earth for laboratory study. The preliminary examination of these samples shows that the nonvolatile portion of the comet is an unequilibrated assortment of materials that have both presolar and solar system origin. The comet contains an abundance of silicate grains that are much larger than predictions of interstellar grain models, and many of these are high-temperature minerals that appear to have formed in the inner regions of the solar nebula. Their presence in a comet proves that the formation of the solar system included mixing on the grandest scales.

[AUTOLINE. Effectiveness of an infusion warmer concept]

BACKGROUND

Coaxial fluid warmers directly heat the tubing surrounding the infusate right up to the intravenous cannula of the patient. This study examined whether the heating capability of one such fluid warmer, the Autoline, could be further increased by using pre-heated infusions as well as using a specifically designed warm-plated infusion holder, the Autotherm, which surrounds the bottled infusions.

METHODS

The final temperatures of crystalloid infusates were measured at the end of the Autoline tubing. With the initial infusion temperatures being kept at either 20 degrees C or 36 degrees C, the subsequent measurements took place at 7 different flow rates between 50 and 1000 ml/h. Using the 36 degrees C pre-heated crystalloid group, further separate measurements were also undertaken by additionally installing the Autotherm. All measurements took place at a constant room temperature of 20 degrees C. The final temperatures were analysed for significant differences between the groups using the one-way ANOVA and post-hoc tests (Bonferroni).

RESULTS

Using pre-heated infusions at low flow rates of 50 and 100 ml/h, the heating capability of the Autoline could be increased by 0.8 and 1.6% (p<0.01), respectively. However, the additional use of the Autotherm device reduced its heating capability by 3.2 and 6.1% (p<0.001), respectively. Using flow rates above 200 ml/h, the heating capability of the Autoline could be increased between 9.2 and 28.6% by pre-heating infusions to 36 degrees C (p<0.01). The additional use of the Autotherm device at these higher flow rates resulted in an increase of the final infusate temperature of 12.7% up to 40.5% (p<0.01).

CONCLUSIONS

The Autoline demonstrated sufficient heating capabilities at flow rates between 50 and 200 ml/h, which can be further increased by pre-heating the infusions to 36 degrees C. At flow rates above 200 ml/h, however, it becomes necessary to use pre-heated infusions, whereas at flow rates above 600 ml/h it becomes further necessary to also use the Autotherm device if final infusates of at least 34 degrees C are to be achieved.

Hotline® 2: Leistungskapazität eines neuen koaxialen Infusionswärmesystems im Bereich niedriger und moderater Flussraten

OBJECTIVE

The aim of this study was to compare the effects of two coaxial fluid warming systems with their heating capabilities.

METHODS

The heating capabilities of two coaxial fluid warming systems and their capabilities to warm fluids at 20 +/- 0.5 degrees C (20 degrees C room temperature) was measured: 1) Hotline 1 Fluid Warmer, 2) Hotline(R) 1 Fluid Warmer. Final temperatures were measured at different infusion rates (10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 200, 400, 800, 1000 ml/h and at maximal flow rates (Vmax)), at the distal end of the disposable tubing. Statistical analysis was performed using a computer based program (NCSS). Differences between the groups were analysed using the Two-Way-ANOVA. Significance was defined at a p < 0.05.

RESULTS

At flow rates between 10 - 1000 ml/h, infusion temperatures of > 36 degrees C were attained by both devices in a reliable manner. Compared to Hotline 1, Hotline 2 attained higher final temperatures of between 1.2 - 3.8 % (p < 0.01). Hotline 1 was measured to have higher Vmax (+ 3.6 %) compared to Hotline 2 (p < 0.01). However, the mean final temperature at Vmax of Hotline 2 was increased by 6.5 % (p < 0.01). The time needed to warm target temperature to 40 - 41 degrees C took between 9 to 12 minutes (flow rate 10 ml/h and Vmax respectively) when using Hotline 1 and 3 to 4 minutes when using Hotline 2.

CONCLUSION

Compared to its predecessor, the Hotline 2 performance is a valuable improvement with respect to heating capacity and clinical handling.

Leistungskapazität von vier Infusionswärmesystemen bei niedrigen Flussraten

OBJECTIVE

The aim of the study was to compare the effects of different fluid warming systems on their heating capabilities during low infusion rates.

METHODS

Heating capabilities of four different fluid warming systems and their capabilities to warm fluids with 20 +/- 0.5 degrees C above 32 degrees C were measured: 1) Hotline(R) Fluid Warmer, 2) Gymar, using three disposable tubing systems - "Pediatric", "Standard", and "High-Flow", 3) Astotherm, and 4) Astotherm plus 260. Low to moderate infusion rates (100, 300, 600, and 900 ml/h) were achieved using motor pumps. Infusate temperatures were measured at 17 degrees C and 20 degrees C room temperature at the distal end of the disposable tubing. Statistical analysis was performed using a computer based program (NCSS). Differences between the groups were analysed by the unpaired Wilcoxon Test. Significance was defined with a p < 0.05.

RESULTS

During low to moderate infusion rates (100 - 900 ml/h), infusate temperatures of > 32 degrees C were attained only by the Hotline-device in a reliable manner independent of the applied room temperature. The devices Astotherm plus 260 und Astotherm attained these temperatures during infusion rates of 300 ml/h and 600 ml/h respectively. Final temperatures of > 32 degrees C were maintained by Gymar during infusion rates of 600 ml/h, when the disposable tubing system "Pediatric" was used. Using the same device but different tubing systems, final temperatures of >32 degrees C were attained during 900 ml/h ("Standard") or failed ("High-Flow"). With all devices, increasing the room temperature by 3 degrees C was followed by higher infusate temperatures, which were more pronounced in those devices without disposable tubing warming (p < 0.01).

CONCLUSION

In this laboratory investigation, Hotline performance was superior with respect to providing final temperatures > 32 degrees C during low to moderate infusion rates. Astotherm Plus 260 seems to be an alternative cost effective device in case of infusion rates of more than 300 ml/h.

The air elimination capabilities of pressure infusion devices and fluid-warmers

Pressurised infusion devices may have only limited capability to detect and remove air during pressurised infusions. In order to assess pressure infusion systems with regard to their actual air elimination capabilities four disposable pressure infusion systems and fluid warmers were investigated: The Level 1 (L-1), Ranger (RA), Gymar (GY), and the Warmflo (WF). Different volumes of air were injected proximal to the heat exchanger and the remaining amount of air that was delivered at the end of the tubing was measured during pressurised infusions. Elimination of the injected air (100-200 ml) was superior by the RA system when compared to L-1 (p < 0.01). The GY and WF systems failed to eliminate the injected air. In conclusion, air elimination was best performed by the RA system. In terms of the risk of air embolism during pressurised infusions, improvements in air elimination of the investigated devices are still necessary.

On the mechanism of cleavage furrow ingression in Dictyostelium

The ability of Dictyostelium cells to divide without myosin II in a cell cycle-coupled manner has opened two questions about the mechanism of cleavage furrow ingression. First, are there other possible functions for myosin II in this process except for generating contraction of the furrow by a sliding filament mechanism? Second, what could be an alternative mechanical basis for the furrowing? Using aberrant changes of the cell shape and anomalous localization of the actin-binding protein cortexillin I during asymmetric cytokinesis in myosin II-deficient cells as clues, it is proposed that myosin II filaments act as a mechanical lens in cytokinesis. The mechanical lens serves to focus the forces that induce the furrowing to the center of the midzone, a cortical region where cortexillins are enriched in dividing cells. Additionally, continual disassembly of a filamentous actin meshwork at the midzone is a prerequisite for normal ingression of the cleavage furrow and a successful cytokinesis. If this process is interrupted, as it occurs in cells that lack cortexillins, an overassembly of filamentous actin at the midzone obstructs the normal cleavage. Disassembly of the crosslinked actin network can generate entropic contractile forces in the cortex, and may be considered as an alternative mechanism for driving ingression of the cleavage furrow. Instead of invoking different types of cytokinesis that operate under attached and unattached conditions in Dictyostelium, it is anticipated that these cells use a universal multifaceted mechanism to divide, which is only moderately sensitive to elimination of its constituent mechanical processes.

Dynamics of the Dictyostelium Arp2/3 complex in endocytosis, cytokinesis, and chemotaxis

The Arp2/3 complex is a ubiquitous and important regulator of the actin cytoskeleton. Here we identify this complex from Dictyostelium and investigate its dynamics in live cells. The predicted sequences of the subunits show a strong homology to the members of the mammalian complex, with the larger subunits generally better conserved than the smaller ones. In the highly motile cells of Dictyostelium, the Arp2/3 complex is rapidly re-distributed to the cytoskeleton in response to external stimuli. Fusions of Arp3 and p41-Arc with GFP reveal that in phagocytosis, macropinocytosis, and chemotaxis the complex is recruited within seconds to sites where actin polymerization is induced. In contrast, there is little or no localization to the cleavage furrow during cytokinesis. Rather the Arp2/3 complex is enriched in ruffles at the polar regions of mitotic cells, which suggests a role in actin polymerization in these ruffles.

A role for myosin VII in dynamic cell adhesion

BACKGROUND

The initial stages of phagocytosis and cell motility resemble each other. The extension of a pseudopod at the leading edge of a migratory cell and the formation of a phagocytic cup are actin dependent, and each rely on the plasma membrane adhering to a surface during dynamic extension.

RESULTS

A myosin VII null mutant exhibited a drastic loss of adhesion to particles, consistent with the extent of an observed decrease in particle uptake. Additionally, cell-cell adhesion and the adhesion of the leading edge to the substratum during cell migration were defective in the myosin VII null cells. GFP-myosin VII rescued the phagocytosis defect of the null mutant and was distributed in the cytosol and recruited to the cortical cytoskeleton, where it appeared to be enriched at the tips of filopods. It was also localized to phagocytic cups, but only during the initial stages of particle engulfment. During migration, GFP-myosin VII is found at the leading edge of the cell.

CONCLUSIONS

Myosin VII plays an important role in mediating the initial binding of cells to substrata, a novel role for an unconventional myosin.

Immunohistochemical characterization of the pancreatic cellular infiltrate in normal pancreas, chronic pancreatitis and pancreatic carcinoma

BACKGROUND/AIMS

Chronic pancreatitis is histologically characterized by an extended fibrosis and infiltration of leukocytes. We intended to differentiate the infiltration to evaluate the inflammatory process.

METHODS

Samples of tissues of normal pancreas (NP, n = 12), of chronic pancreatitis (CP, n = 7), and pancreatic tissues surrounding pancreatic carcinoma (CA, n = 7) were investigated by immunohistochemical staining using the APAAP technique.

RESULTS

In normal pancreas, mononuclear cells (47.1 +/- 26.0 cells/mm2) were observed with a predominance of macrophages (56.3%) and T lymphocytes (31.3%) which were differentiated in CD8+ lymphocytes (9.3 +/- 7.2 cells/ mm2) and CD4+ lymphocytes (6.7 +/- 3.2 cells/mm2). Rarely, plasma cells (5.3%) and B lymphocytes (7.1%) could be detected. In pancreatic tissue of patients with CP and in CA there was a significant increase of mononuclear cells to 264.4 +/- 120.3 cells/mm2 and 284.3 +/- 67.8 cells/mm2, respectively. In both diseases percentages of T lymphocytes (CP: 50.5%; CA: 48.1%) were higher than in normal controls. CD4+/CD8+ ratio of 0.77 in CP and 0.82 in CA demonstrated a predominance of CD8+ cells compared to the peripheral blood. In NP and CA, nearly all T lymphocytes expressed CD45R0 identifying memory cells, while only 58% of T lymphocytes were CD45R0 positive in CP.

CONCLUSION

Our data suggest that the investigated cases of CP were of a common inflammatory type rather than due to an autoimmunological reaction. CD8+ T lymphocytes were the predominant T cell subset in the inflammatory infiltrates in both CP and CA.

[Outpatient treatment of patients with cardiovascular diseases]

In Germany, cardiovascular disturbances belong to the diseases most frequently treated in the offices of general practitioners and internal specialists. With comprehensive monitoring and the taking of adequate therapeutic measures, the average mortality age of the majority of the 18 million patients suffering from circulatory diseases lies at 79.4 years. In the age group of over 70 years, 70 to 80% of the patients receive treatment against cardiovascular disturbances, most of them against hypertension. One of the most important goals of monitoring and intervention in the outpatient sector is the treatment of hypertension, especially in connection with measures taken against disturbances in lipometabolism in order to prevent secondary diseases. The success of treatment is shown by the decreasing age standardized rate of cardiac infarctions, especially among men, and the decreasing mortality rate of patients below 65. The increasing treatment in the outpatient sector is accompanied by additional interventions, especially by bypass surgery in the hospital sector. The concerted actions in both the outpatient and the inpatient sector result in a higher service provision to come to a higher quality of life in the patients and to prevent early death.

Two-step positioning of a cleavage furrow by cortexillin and myosin II

BACKGROUND

Myosin II, a conventional myosin, is dispensable for mitotic division in Dictyostelium if the cells are attached to a substrate, but is required when the cells are growing in suspension. Only a small fraction of myosin II-null cells fail to divide when attached to a substrate. Cortexillins are actin-bundling proteins that translocate to the midzone of mitotic cells and are important for the formation of a cleavage furrow, even in attached cells. Here, we investigated how myosin II and cortexillin I cooperate to determine the position of a cleavage furrow.

RESULTS

Using a green fluorescent protein (GFP)-cortexillin I fusion protein as a marker for priming of a cleavage furrow, we found that positioning of a cleavage furrow occurred in two steps. In the first step, which was independent of myosin II and substrate, cortexillin I delineated a zone around the equatorial region of the cell. Myosin II then focused the cleavage furrow to the middle of this cortexillin I zone. If asymmetric cleavage in the absence of myosin II partitioned a cell into a binucleate and an anucleate portion, cell-surface ruffles were induced along the cleavage furrow, which led to movement of the anucleate portion along the connecting strand towards the binucleate one.

CONCLUSIONS

In myosin II-null cells, cleavage furrow positioning occurs in two steps: priming of the furrow region and actual cleavage, which may proceed in the middle or at one border of the cortexillin ring. A control mechanism acting at late cytokinesis prevents cell division into an anucleate and a binucleate portion, causing a displaced furrow to regress if it becomes aberrantly located on top of polar microtubule asters.

Anaerobic nitrate reductase (narGHJI) activity of Mycobacterium bovis BCG in vitro and its contribution to virulence in immunodeficient mice

Mycobacterium tuberculosis and Mycobacterium bovis cause tuberculosis, which is responsible for the deaths of more people each year than any other bacterial infectious disease. Disseminated disease with Mycobacterium bovis BCG, the only currently available vaccine against tuberculosis, occurs in immunocompetent and immunodeficient individuals. Although mycobacteria are obligate aerobes, they are thought to face an anaerobic environment during infection, notably inside abscesses and granulomas. The purpose of this study was to define a metabolic pathway that could allow mycobacteria to exist under these conditions. Recently, the complete genome of M. tuberculosis has been sequenced, and genes homologous to an anaerobic nitrate reductase (narGHJI), an enzyme allowing nitrate respiration when oxygen is absent, were found. Here, we show that the narGHJI cluster of M. tuberculosis is functional as it conferred anaerobic nitrate reductase activity to Mycobacterium smegmatis. A narG mutant of M. bovis BCG was generated by targeted gene deletion. The mutant lacked the ability to reduce nitrate under anaerobic conditions. Both mutant and M. bovis BCG wild type grew equally well under aerobic conditions in vitro. Histology of immunodeficient mice (SCID) infected with M. bovis BCG wild type revealed large granulomas teeming with acid-fast bacilli; all mice showed signs of clinical disease after 50 days and succumbed after 80 days. In contrast, mice infected with the mutant had smaller granulomas containing fewer bacteria; these mice showed no signs of clinical disease after more than 200 days. Thus, it seems that nitrate respiration contributes significantly to virulence of M. bovis BCG in immunodeficient SCID mice.

Cytokinesis without myosin II

The ability of substrate-anchored Dictyostelium cells to divide without myosin II has opened the possibility of analysing the formation of cleavage furrows in the absence of a contractile ring made of filamentous myosin and actin. Similar possibilities exist in mutants of budding yeast and, less strictly, also in drug-treated mammalian cells. Myosin-II-independent activities in Dictyostelium include the microtubule-induced programming of the cell surface into ruffling areas and regions that are converted into a concave furrow, as well as the translocation of cortexillins and cross-linked membrane proteins towards the cleavage furrow. A centripetal flow of actin filaments followed by their disassembly in the cleavage furrow is proposed to underlie the translocation.

[Initial effects of the 1998 revised narcotic law in substitute drug treatment of narcotic dependent patients--results of a physician survey]

To study the consequences of the last revision of the German narcotics act (1998, which forbids prescribing codeines as substitutes), a survey was carried out several months after implementation with 639 physicians, who gave substitution treatment. It could be determined how far codeine patients were ready to change their substitute, how content physicians said their patients were after changing the substitute and which were the attitudes of physicians to the revision in question.

RESULTS

The majority of patients (70%) who were formerly substituted by means of codeine accepted methadone as a substitute. After the method of substitution had been changed, 51% of patients had been classified as "very content" and 35% as "reasonably content". Especially those physicians who prescribed codeines in the past, unlike physicians who used methadone for substitution treatment only, criticised the revision in question and feared that many patients should be without medical care as a consequence of the new situation.

Responses to depression in unipolar depressed patients: an investigation of Nolen-Hoeksema's response styles theory

BACKGROUND

The response styles theory suggests that rumination in response to depressed mood exacerbates and prolongs depression, while distraction ameliorates and shortens it. Gender differences in response styles are said to contribute to the observed gender differences in the prevalence of unipolar depression. While empirical support for the theory has been found from a variety of non-clinical studies, its generalizability to clinically depressed patient populations remains unclear.

METHODS

A cohort of 52 unipolar depressed in-patients was assessed with the Response Styles Questionnaire during in-patient stay (T1) and 4 weeks after discharge (T2). The patients were followed up 4 months after discharge (T3). Clinical assessment included the SCAN-PSE-10.

RESULTS

Moderate and statistically significant retest-stabilities for rumination and distraction were found, comparable for patients with stable and changing depression status from T1 to T2. A cross-sectional diagnosis of a major depressive episode was associated with rumination, while gender was not. Post-discharge baseline rumination (T2), adjusted for concurrent depression, predicted follow-up levels of depression (T3), and, in patients who were non-remitted at post-discharge baseline, it predicted presence of a major depressive episode at follow-up (T3). Results on distraction were more ambiguous.

CONCLUSIONS

Our results suggest that rumination is likely to have a deteriorating impact on the course of clinical episodes of depression in unipolar depressed patients. Larger longitudinal patient studies are needed to validate these findings.

Domain analysis of cortexillin I: actin-bundling, PIP(2)-binding and the rescue of cytokinesis

Cortexillins are actin-bundling proteins that form a parallel two-stranded coiled-coil rod. Actin-binding domains of the alpha-actinin/spectrin type are located N-terminal to the rod and unique sequence elements are found in the C-terminal region. Domain analysis in vitro revealed that the N-terminal domains are not responsible for the strong actin-filament bundling activity of cortexillin I. The strongest activity resides in the C-terminal region. Phosphatidylinositol 4,5-bisphosphate (PIP(2)) suppresses this bundling activity by binding to a C-terminal nonapeptide sequence. These data define a new PIP(2)-regulated actin-bundling site. In vivo the PIP(2)-binding motif enhances localization of a C-terminal cortexillin I fragment to the cell cortex and improves the rescue of cytokinesis. This motif is not required, however, for translocation to the cleavage furrow. A model is presented proposing that cortexillin translocation is based on a mitotic cycle of polar actin polymerization and midzone depolymerization.

Computer-assisted morphometry of cell-substratum contacts

AIM

Quantitative analysis of size and shape of the cell-substratum contacts in Dictyostelium and comparison of these parameters between wild-type cells and the cells bearing cytoskeletal protein mutations.

METHODS

Reflection interference contrast microscopy (RICM) was used to image the areas of contact between aggregation-competent Dictyostelium cells and weakly adhesive mica surfaces. The cell-substratum contact areas were automatically identified in RICM micrographs by digital image processing. Information about the size and shape of the contact areas was obtained by using the shape descriptors based on two-dimensional geometrical moment invariants.

RESULTS

Lack of either of the two actin-crosslinking proteins, a-actinin and 120 kDa gelation factor, similarly affects the cell-substratum interactions of Dictyostelium cells. The shape descriptors, elongation and dispersion, of the contact areas were reduced by 10% to 30% in mutant cells when compared to the wild type, but the size of the contacts was not affected.

CONCLUSION

Video microscopy combined with digital image processing and quantitative image analysis is capable of revealing small phenotypic effects of cytoskeletal protein mutations on the level of single cells. Such automated microscopic methods are expected to gain importance and find a widespread use in biomedicine.

Predictive control of hollow-fiber bioreactors for the production of monoclonal antibodies

The selection of medium feed rates for perfusion bioreactors represents a challenge for process optimization, particularly in bioreactors that are sampled infrequently. When the present and immediate future of a bioprocess can be adequately described, predictive control can minimize deviations from set points in a manner that can maximize process consistency. Predictive control of perfusion hollow-fiber bioreactors was investigated in a series of hybridoma cell cultures that compared operator control to computer estimation of feed rates. Adaptive software routines were developed to estimate the current and predict the future glucose uptake and lactate production of the bioprocess at each sampling interval. The current and future glucose uptake rates were used to select the perfusion feed rate in a designed response to deviations from the set point values. The routines presented a graphical user interface through which the operator was able to view the up-to-date culture performance and assess the model description of the immediate future culture performance. In addition, fewer samples were taken in the computer-estimated cultures, reducing labor and analytical expense. The use of these predictive controller routines and the graphical user interface decreased the glucose and lactate concentration variances up to sevenfold, and antibody yields increased by 10% to 43%.

Cytoskeletal protein mutations and cell motility in Dictyostelium

Dictyostelium is a suitable experimental system in which to study the effects of mutations in actin-binding proteins on cell motility. Three cytoskeletal mutants that show distinct alterations in cell shape, chemotactic movement and cytokinesis serve to illustrate the diversity of phenotypes. Cells lacking talin, a protein which in many mammalian cell types is a constituent of focal complexes that link the actin cytoskeleton to the plasma membrane, are strongly impaired in adhesion to external surfaces. Coronin is an actin-associated protein that belongs to the WD-repeat family of proteins, which are engaged in protein-protein interactions involved in signalling pathways. Cells lacking coronin build large hyaline protrusions at their leading edge, diagnostic of an imbalance in the actin polymerization/depolymerization cycle. Cells devoid of a pair of cortexillins, which are novel members of the spectrin/alpha-actinin superfamily of actin-binding proteins, form an atypical cleavage furrow on a solid surface and fail to divide in suspension. Other mutants in which one or more actin-binding proteins have been knocked out have weaker phenotypes. With these mutants, cells need to be subjected to special conditions in order to reveal an effect on cell motility. For instance, only on weakly adhesive surfaces is a disturbance in the spatio-temporal co-ordination of protrusion and retraction of the cell body, and of the attachment to and detachment from a substratum, observed in a mutant that lacks three actin-binding proteins: alpha-actinin, 120 kDa F-actin gelation factor and severin.

Cytokinesis mediated through the recruitment of cortexillins into the cleavage furrow

The fact that substrate-anchored Dictyostelium cells undergo cytokinesis in the absence of myosin II underscores the importance of other proteins in enabling the cleavage furrow to constrict. Cortexillins, a pair of actin-bundling proteins, are required for normal cleavage. They are targeted to the incipient furrow in wild-type and, more prominently, in myosin II-null cells. No other F-actin bundling or cross-linking protein tested is co-localized. Green fluorescent protein fusions show that the N-terminal actin-binding domain of cortexillin I is dispensable and the C-terminal region is sufficient for translocation to the furrow and the rescue of cytokinesis. Cortexillins are suggested to have a targeting signal for coupling to a myosin II-independent system that directs transport of membrane proteins to the cleavage furrow.

Normalization of fasting glycaemia by intravenous GLP-1 ([7-36 amide] or [7-37]) in type 2 diabetic patients

Intravenous GLP-1 [7-36 amide] can normalize fasting hyperglycaemia in Type 2 diabetic patients. Whether GLP-1 [7-37] has similar effects and how quickly plasma glucose concentrations revert to hyperglycaemia after stopping GLP-1 is not known. Therefore, 8 patients with Type 2 diabetes (5 female, 3 male; 65+/-6 years; BMI 34.3+/-7.9 kg m(-2); HbA1c 9.6+/-1.2%; treatment with diet alone (n=2), sulphonylurea (n=5), metformin (n=1)) were examined twice in randomized order. GLP-1 [7-36 amide] or [7-37] (1 pmol kg(-1)min(-1) were infused intravenously over 4 h in fasted subjects. Plasma glucose (glucose-oxidase), insulin and C-peptide (ELISA) was measured during infusion and for 4 h thereafter. Indirect calorimetry was performed. Fasting hyperglycaemia was 11.7+/-0.9 [7-36 amide] and 11.3+/-0.9 mmol l(-1) [7-37]. GLP-1 infusions stimulated insulin secretion approximately 3-fold (insulin peak 168+/-32 and 156+/-47 pmol l(-1), p<0.0001 vs basal; C-peptide peak 2.32+/-0.28 and 2.34+/-0.43 nmol l(-1), p<0.0001, respectively, with GLP-1 [7-36 amide] and [7-37]). Four hours of GLP-1 infusion reduced plasma glucose (4.8+/-0.4 and 4.6+/-0.3 mmol l(-1), p<0.0001 vs basal values), and it remained in the non-diabetic fasting range after a further 4 h (5.1+/-0.4 and 5.3+/-0.4 mmol l(-1), for GLP [7-36 amide] and [7-37], respectively). There were no significant differences between GLP-1 [7-36 amide] and [7-37] (glucose, p=0.99; insulin, p=0.99; C-peptide, p=0.99). Neither glucose oxidation nor lipid oxidation (or any other parameters determined by indirect calorimetry) changed during or after the administration of exogenous GLP-1. In conclusion, GLP-1 [7-36 amide] and [7-37] normalize fasting hyperglycaemia in Type 2 diabetic patients. Diabetes therapy (diet, sulphonyl ureas or metformin) does not appear to influence this effect. In fasting and resting patients, the effect persists during administration of GLP-1 and for at least 4 h thereafter, without rebound. Significant changes in circulating substrate concentrations (e.g. glucose) are not accompanied by changes in intracellular substrate metabolism.

Three-dimensional patterns and redistribution of myosin II and actin in mitotic Dictyostelium cells

Myosin II is not essential for cytokinesis in cells of Dictyostelium discoideum that are anchored on a substrate (Neujahr, R., C. Heizer, and G. Gerisch. 1997. J. Cell Sci. 110:123-137), in contrast to its importance for cell division in suspension (DeLozanne, A., and J.A. Spudich. 1987. Science. 236:1086-1091; Knecht, D.A., and W.F. Loomis. 1987. Science. 236: 1081-1085.). These differences have prompted us to investigate the three-dimensional distribution of myosin II in cells dividing under one of three conditions: (a) in shaken suspension, (b) in a fluid layer on a solid substrate surface, and (c) under mechanical stress applied by compressing the cells. Under the first and second conditions outlined above, myosin II does not form patterns that suggest a contractile ring is established in the furrow. Most of the myosin II is concentrated in the regions that flank the furrow on both sides towards the poles of the dividing cell. It is only when cells are compressed that myosin II extensively accumulates in the cleavage furrow, as has been previously described (Fukui, Y., T.J. Lynch, H. Brzeska, and E.D. Korn. 1989. Nature. 341:328-331), i.e., this massive accumulation is a response to the mechanical stress. Evidence is provided that the stress-associated translocation of myosin II to the cell cortex is a result of the dephosphorylation of its heavy chains. F-actin is localized in the dividing cells in a distinctly different pattern from that of myosin II. The F-actin is shown to accumulate primarily in protrusions at the two poles that ultimately form the leading edges of the daughter cells. This distribution changes dynamically as visualized in living cells with a green fluorescent protein-actin fusion.

Cu/Zn-SOD in human pancreatic tissue and pancreatic juice

CONCLUSION

Cu/Zn-SOD is present in pancreatic juice and tissue. Immunohistochemical studies reveal a localization of this enzyme in islet, duct, and centroacinar cells, but to a much lower extent in pancreatic acinar cells.

BACKGROUND

It is generally accepted that oxygen radicals are involved in the pathogenesis of acute and chronic pancreatitis. An imbalance of radical-generating and radical-scavenging processes is thought to lead to the damage of pancreatic acinar cells that initiate the autodigestion of the whole organ.

METHODS

We investigated the distribution pattern of the cytosolic radical-scavenging enzyme, copper/zinc-superoxide dismutase (Cu/Zn-SOD), in pancreatic juice and tissue. In patients with chronic pancreatitis or pancreatic malignancies, Cu-Zn-SOD was quantitated in different fractions of pancreatic juice by means of an enzyme immunoassay using two Cu/Zn-SOD-specific monoclonal antibodies. Cryostat or paraffin sections of pancreatic tissue were analyzed by immunohistochemical techniques.

RESULTS

We found this enzyme to be present in the first secretin-triggered fraction of endoscopically obtained pancreatic juice in concentrations similar to serum. In contrast, after cholecystokinin stimulation, only low levels could be found in pancreatic juice, indicating that this enzyme is not actively secreted. Interestingly, pancreatic juice of patients with chronic pancreatitis or pancreas tumor contained higher levels (25-29 ng/mL) of Cu/Zn-SOD than juice of controls without pancreatic diseases (15 ng/mL). Immunohistochemical studies of Cu/Zn-SOD in pancreatic tissue revealed a more intense staining of duct cells, islet cells, and centroacinar cells, whereas acinar cells showed almost no staining for Cu/Zn-SOD.

Talin-null cells of Dictyostelium are strongly defective in adhesion to particle and substrate surfaces and slightly impaired in cytokinesis

Dictyostelium discoideum contains a full-length homologue of talin, a protein implicated in linkage of the actin system to sites of cell-to-substrate adhesion in fibroblasts and neuronal growth cones. Gene replacement eliminated the talin homologue in Dictyostelium and led to defects in phagocytosis and cell-to-substrate interaction of moving cells, two processes dependent on a continuous cross talk between the cell surface and underlying cytoskeleton. The uptake rate of yeast particles was reduced, and only bacteria devoid of the carbohydrate moiety of cell surface lipopolysaccharides were adhesive enough to be recruited by talin-null cells in suspension and phagocytosed. Cell-to-cell adhesion of undeveloped cells was strongly impaired in the absence of talin, in contrast with the cohesion of aggregating cells mediated by the phospholipid-anchored contact site A glycoprotein, which proved to be less talin dependent. The mutant cells were still capable of moving and responding to a chemoattractant, although they attached only loosely to a substrate via small areas of their surface. With their high proportion of binucleated cells, the talin-null mutants revealed interactions of the mitotic apparatus with the cell cortex that were not obvious in mononucleated cells.