Characterization and source apportionment of single particles from metalworking activities

Industrial metalworking facilities emit a variety of air toxics including volatile organic compounds, polycyclic aromatic hydrocarbons (PAHs) and heavy metals. In order to investigate these emissions, a 1-month multi-instrument field campaign was undertaken at an industrial site in Grande-Synthe, Dunkirk (France), in May and June 2012. One of the main objectives of the study was to provide new information on the chemical composition of particulate matter with aerodynamic diameters smaller than 2.5 μm (PM_2.5) in the vicinity of metalworking facilities. An aerosol time-of-flight mass spectrometer (ATOFMS) was deployed to provide size-resolved chemical mixing state measurements of ambient single particles at high temporal resolution. This mixing state information was then used to apportion PM_2.5 to local metalworking facilities influencing the receptor site. Periods when the site was influenced by metalworking sources were characterised by a pronounced increase in particles containing toxic metals (manganese, iron, lead) and polycyclic aromatic hydrocarbons (PAHs) with a variety of chemical mixing states. The association of specific particle classes with a nearby ferromanganese alloy manufacturing plant was confirmed through comparison with previous analysis of raw materials (ores) and chimney filter particle samples collected at the facility. Particles associated with emissions from a nearby steelworks were also identified. The contribution of local metalworking activities to PM_2.5 at the receptor site for the period when the ATOFMS was deployed ranged from 1 to 65% with an average contribution of 17%, while the remaining mass was attributed to other local and regional sources. These findings demonstrate the impact of metalworking facilities on air quality downwind and provide useful single particle signatures for future source apportionment studies in communities impacted by metalworking emissions.

Novel methods for in vitro modeling of pancreatic cancer reveal important aspects for successful primary cell culture

Background

Pancreatic cancer remains a fatal disease. Experimental systems are needed for personalized treatment strategies, drug testing and to further understand tumor biology. Cell cultures can serve as an excellent preclinical platform, but their generation remains challenging.

Methods

Tumor cells from surgically removed pancreatic ductal adenocarcinoma (PDAC) specimens were cultured under novel protocols. Cellular growth and composition were analyzed and culture conditions were continuously optimized. Characterization of cell cultures and primary tumors was performed via hematoxylin and eosin (HE) and immunofluorescence (IF) staining.

Results

Protocols for two- and three-dimensional PDAC primary cell cultures could successfully be established. Primary cell culture depended on dissociation techniques, growth factor supplementation and extracellular matrix components containing Matrigel being crucial for the transformation to three-dimensional PDAC organoids. The generated cultures showed to be highly resemblant to established PDAC primary cell cultures. HE and IF staining for cell culture and corresponding primary tumor characterization could successfully be performed.

Conclusions

The work presented herein shows novel and effective methods to successfully establish primary PDAC cell cultures in a distinct time frame. Factors contributing to cell growth and differentiation could be identified with important implications for further primary cell culture protocols. The established protocols might serve as novel tools in personalized tumor therapy.

Investigation on the near-field evolution of industrial plumes from metalworking activities

In a context where a significant fraction of the population lives near industrial areas, the main objectives of this study are to provide (a) new data on PM_2.5 chemical compositions, heavy-metal concentrations and trace gases released by metalworking activities and (b) new information on the near-field evolution (up to about a thousand meters) of such industrial plumes in terms of particle chemical composition and size distribution. For that purpose, a one-month field campaign was performed in an industrial area near the city of Dunkirk (Northern France), combining measurements of atmospheric dynamics and physico-chemical characterization of air masses. Comparisons between several elemental ratios (mainly Mn/Fe), particle size distributions and volatile organic compound (VOC) concentrations at the stacks and at a near-field site suggest that plumes of a ferromanganese alloy plant were quickly mixed with pollutants emitted by other sources (mainly other industries, possibly traffic and sea spray), in particular a neighboring steelworks, before reaching the sampling site. This led to the emergence of secondary particles related to condensation and/or aggregation phenomena inside the plumes. Metalworking emissions were also identified as a source of new particle formation, formed through the emission of gaseous precursors and their fast transformation and condensation, over a timescale of minutes before reaching the near-field site 800 m downwind. Ultrafine particles emitted at the stacks also quickly agglomerated to form larger particles before reaching the near-field site. These results show that, even over short distances, the chemical composition and size distribution of metalworking plumes may evolve rapidly and the characteristics of particles at the boundary of an industrial area (especially in contiguous urban areas) may differ from those emitted directly at the stacks.

Scanning electron microscopy-energy dispersive X-ray spectrometry (SEM-EDX) and aerosol time-of-flight mass spectrometry (ATOFMS) single particle analysis of metallurgy plant emissions

The chemical composition of single particles deposited on industrial filters located in three different chimneys of an iron-manganese (Fe-Mn) alloy manufacturing plant have been compared using aerosol time-of-flight mass spectrometry (ATOFMS) and scanning electron microscopy-energy dispersive X-ray spectrometry (SEM-EDX). Very similar types of particles were observed using both analytical techniques. Calcium-containing particles dominated in the firing area of the sintering unit, Mn and/or Al-bearing particles were observed at the cooling area of the sintering unit, while Mn-containing particles were dominant at the smelting unit. SEM-EDX analysis of particles collected downstream of the industrial filters showed that the composition of the particles emitted from the chimneys is very similar to those collected on the filters. ATOFMS analysis of ore samples was also performed to identify particulate emissions that could be generated by wind erosion and manual activities. Specific particle types have been identified for each emission source (chimneys and ore piles) and can be used as tracers for source apportionment of ambient PM measured in the vicinity of the industrial site.

Surgical management of combined anterior or posterior cruciate ligament and posterolateral corner tears: for what functional results?

INTRODUCTION

Management of combined anterior or posterior cruciate ligament and posterolateral corner tears is still poorly codified. The aim of this study was to evaluate functional outcome after complete surgical treatment.

MATERIALS AND METHODS

This retrospective multicenter study included 53 patients. Mean age was 29.8 yrs. (15-49). The anterior and posterior cruciate ligaments were involved in respectively 48 and 5 cases. Mean time to surgery was 25.6 months (0-184), and in 10 cases less than 21 days. Nine patients were sedentary workers and 29 non-sedentary (13 laborers). All ligament injuries were treated surgically. Mean follow-up was 49 months (12-146). Last follow-up assessment used IKDC, Lysholm and KOOS scores.

RESULTS

At last follow-up, IKDC score graded 14 patients A, 25 B, 8 C and 6 D, versus 0 A, 4 B, 25 C, 22 D and 2 ungraded preoperatively. Mean subjective IKDC and Lysholm scores were respectively 72.8 (11.5-100) and 77.5 (37-100). Mean KOOS scores (pain, symptoms, daily life, sports, quality of life) were respectively 78 (3-100), 70 (25-100), 88 (47-100), 53 (0-100) and 50 (0-100). Posterolateral laxity was corrected in all but two cases. All sedentary workers and 86.7% of non-sedentary workers could return to work. The job had to be changed in 10% of cases overall, but in 25% of cases for laborers.

DISCUSSION

The present results are comparable with those of the literature. The strategy of combined surgical treatment showed functional efficacy, usually associated with return to work except for some laborers. There was a non-significant trend in favor of acute-phase ligament reconstruction.

LEVEL OF EVIDENCE

IV (retrospective series).

Immediate passive motion versus immobilization after endoscopic supraspinatus tendon repair: a prospective randomized study

INTRODUCTION

Rehabilitation programs after rotator cuff repair should allow recovery of shoulder function without preventing tendon healing. The aim of this randomized prospective study was to compare the clinical results after two types of postoperative management: immediate passive motion versus immobilization.

PATIENTS AND METHODS

We followed 100 patients, mean age 55 years old, who underwent arthroscopic repair of a non-retracted supraspinatus tear. Patients were randomized to receive postoperative management of immediate passive motion or strict immobilization for 6 weeks. A clinical evaluation was performed in 92 patients, and CT arthrography in 82. Mean follow-up was 15 months.

RESULTS

The mean preoperative Constant score improved significantly from 46.1 points to 73.9 at the final follow-up. The rate of intact cuffs was 58.5%. Functional results were statistically better after immediate passive motion with a mean passive external rotation of 58.7° at the final follow-up versus 49.1° after immobilization (P=0.011), a passive anterior elevation of 172.4° versus 163.3° (P=0.094) respectively, a Constant score of 77.6 points versus 69.7 (P=0.045) respectively, and a lower rate of adhesive capsulitis and complex regional pain syndrome. Results for healing seemed to be slightly better with immobilization, but this was not statistically significant: the cuff had a normal appearance in 35.9% of cases after immobilization compared to 25.6% after passive motion, an image of intratendinous addition was found in 25.6% versus 30.2%, punctiform leaks in 23.1% versus 20.9%, and recurrent tears in 15.4% versus 23.3% respectively.

DISCUSSION

The rehabilitation program that results in better tendon healing by preventing postoperative stiffness has not yet been identified. Our results suggest that early passive motion should be authorized: the functional results were better with no significant difference in healing.

Magnetism, f-electron localization and superconductivity in 122-type heavy-fermion metals

Both CeCu2Si2 and YbRh2Si2 crystallize in the tetragonal ThCr2Si2 crystal structure. Recent neutron-scattering results on normal-state CeCu2Si2 reveal a slowing down of the quasielastic response which complies with the scaling expected for a quantum critical point (QCP) of itinerant, i.e., three-dimensional spin-density-wave (SDW), type. This interpretation is in full agreement with the non-Fermi-liquid behavior observed in transport and thermodynamic measurements. The momentum dependence of the magnetic excitation spectrum reveals two branches of an overdamped dispersive mode whose coupling to the heavy charge carriers is strongly retarded. These overdamped spin fluctuations are considered to be the driving force for superconductivity in CeCu2Si2 (Tc = 600 mK). The weak antiferromagnet YbRh2Si2 (TN = 70 mK) exhibits a magnetic-field-induced QCP at BN = 0.06 T (B⊥c). There is no indication of superconductivity down to T = 10 mK. The magnetic QCP appears to concur with a breakdown of the Kondo effect. Doping-induced variations of the average unit-cell volume result in a detachment of the magnetic and electronic instabilities. A comparison of the properties of these isostructural compounds suggests that 3D SDW QCPs are favorable for unconventional superconductivity. The question whether a Kondo-breakdown QCP may also give rise to superconductivity, however, remains to be clarified.

Superconductivity versus quantum criticality: what can we learn from heavy fermions?

Two quantum critical point (QCP) scenarios are being discussed for different classes of antiferromagnetic (AF) heavy-fermion (HF) systems. In the itinerant one, where AF order is of the spin-density wave (SDW) type, the heavy 'composite' charge carriers keep their integrity at the QCP. The second one implies a breakdown of the Kondo effect and a disintegration of the composite fermions at the AF QCP. We discuss two isostructural compounds as exemplary materials for these two different scenarios: CeCu(2)Si(2) exhibits a three-dimensional (3D) SDW QCP and superconductivity, presumably mediated by SDW fluctuations, as strongly suggested by recent inelastic neutron scattering experiments. In Y bRh(2)Si(2), the AF QCP is found to coincide with a Kondo-destroying one. However, in the latter compound these two QCPs can be detached by varying the average unit-cell volume, e.g. through the application of chemical pressure, as realized by partial substitution of either Ir or Co for Rh. A comparison of CeCu(2)Si(2) and Y bRh(2)Si(2) indicates that the apparent differences in quantum critical behaviour go along with disparate behaviour concerning the (non-) existence of superconductivity (SC). No sign of SC could be detected in Y bRh(2)Si(2) down to mK temperatures. A potential correlation between the specific nature of the QCP and the occurrence of SC, however, requires detailed studies on further quantum critical HF superconductors, e.g. on β-Y bAlB(4), UBe(13), CeCoIn(5) and CeRhIn(5).

Vicarious annihilation: the effect of mortality salience on perceptions of hate crimes

Previous research has found that reminding participants of their mortality creates a need for individuals to maintain and defend subjective cultural worldviews. As a result, mortality salient participants typically strive to uphold legal sanctions and also react negatively to individuals who espouse alternative worldview beliefs, exhibiting behaviors toward those targets ranging from verbal derogation to physical aggression. This paper extends this line of research by examining perceptions of hate crimes. Hate crimes represent a unique class of crime where both the perpetrator and victim may be viewed as worldview violators. Study 1 revealed that mortality salient participants were more supportive of hate crime legislation than were control participants when hate crimes were described in abstract terms and no specific victim was mentioned. In Study 2, a specific victim who posed a potential worldview threat was identified. In this case, mortality salient participants were less punitive toward offenders who attacked these specific worldview-threatening victims.

Midazolam amnesia and conceptual processing in implicit memory

Prominent theories of implicit memory (D. Schacter, B. Church, & J. Treadwell, 1994) emphasize the dominant role of perceptual processing in mediating priming on perceptual implicit memory tests. Examinations of the effects of conceptual processing on perceptual implicit memory tests have produced ambiguous results. Although a number of investigations (e.g., J. Toth & R. Hunt, 1990) have demonstrated that variations in conceptual processing affect priming on perceptual implicit memory tests, these effects may arise because of the contaminating effects of explicit memory. The current experiment examined this controversy using midazolam, a benzodiazepine that produces a dense, albeit temporary, anterograde amnesia when injected prior to study. The experiment examined whether the effects of generation found on the implicit memory test of perceptual identification were affected by a midazolam injection prior to study. Results demonstrated that midazolam substantially diminished generation effects in free and cued recall, as well as overall performance on these tests, but had no detectable effect on the generation effect in perceptual identification.

Being accepted for who we are: evidence that social validation of the intrinsic self reduces general defensiveness

Three studies examined the possibility that being liked intrinsically by others--for who one is--reduces self-esteem defense, whereas being liked for what one has achieved does not. All 3 studies contrasted the effects on self-esteem defense of liking based on intrinsic or achievement-related aspects of self. Study 1 showed that thoughts of being liked intrinsically reduced defensive bias toward downward social comparison. Study 2 demonstrated that being liked for intrinsic aspects of self reduced participants' tendency to defensively distance themselves from a negatively portrayed other. Study 3 revealed that being liked for intrinsic aspects of self encouraged a preference for upward over downward counterfactuals for a negative event. In all 3 studies, similar reductions in defensiveness were not found when liking was based on achievements. Discussion focuses on implications for understanding the functional value of different bases of self-worth.

Comparative dosimetry in narrow high-energy photon beams

A comparison of the response of different dosimeters in narrow photon beams (phi > or = 4 mm) of 6 and 18 MV bremsstrahlung has been performed. The detectors used were a natural diamond detector, a liquid ionization chamber, a plastic scintillator and two dedicated silicon diodes. The diodes had a very small detection volume and one was a specially designed double diode using two parallel opposed active volumes with compensating interface perturbations. The characteristics of the detectors were investigated both for dose distribution measurements, such as depth-dose curves and lateral beam profiles, and for output factors. The dose rate and angular dependence of the diamond and the two diodes were also studied separately. The depth-dose distributions for small fields agree well for the diamond, the scintillator and the single diode, while the measured dose maximum for the double diode is about 1% higher and for the liquid chamber about 1% lower than the mean of the others when normalized at a depth of 10 cm. The plastic scintillator and the liquid ionization chamber detect a penumbra width that is slightly broadened due to the influence of their finite size, while the double diode may even underestimate the penumbra width due to its small size and high density. When corrected for the extension of the detector volume a good agreement with Monte Carlo calculated beam profiles was obtained for the plastic scintillator and the liquid ionization chamber. Profiles measured with the diamond show an asymmetry when positioned with the smallest dimension facing the beam, while the double diode, the scintillator and the liquid chamber measure symmetric profiles irrespective of positioning. Significant differences in the output factors were obtained with the different detectors. The natural diamond detector measures output factors close to those with an ionization chamber (less than 1% difference) for field sizes between 3 x 3 and 15 x 15 cm2, but overestimates the output factors for large fields and underestimates the output factors for the smallest field sizes. The single and double diodes overestimated the output factor for large field sizes by up to 7 and 12% respectively due to the high content of low-energy photons. The double diode, and to some extent the single diode, also showed a relative increase in response compared with the more water equivalent liquid chamber and plastic scintillator at the smallest fields where there is a lack of lateral electron equilibrium. Both the plastic scintillator and the liquid chamber also show responses that deviate from the ionization chamber for larger field sizes. The major deviations can be explained based on the characteristics of the sensitive materials and the construction of the detectors.

Running from the shadow: psychological distancing from others to deny characteristics people fear in themselves

Four experiments tested the hypothesis that people distance themselves from others who display characteristics they fear in themselves. In Study 1, participants were given false feedback that they were high or low in repressed anger and were given information about a person who became angry and responded in a violent or nonviolent manner. High anger feedback participants distanced themselves only from the violent person. In Study 2, high anger feedback led to distancing from a violent other but not a dishonest other, whereas dishonesty feedback led to distancing from a dishonest other but not a violent other. The results of Studies 3 and 4 replicated and extended the distancing effect with an anger induction: Participants who were insulted distanced themselves from an angry/violent person, and verbalizing their emotions about being insulted eliminated this effect. Implications for understanding defenses against undesirable self-attributions are discussed.

Stereotypes and terror management: evidence that mortality salience enhances stereotypic thinking and preferences

If stereotypes function to protect people against death-related concerns, then mortality salience should increase stereotypic thinking and preferences for stereotype-confirming individuals. Study 1 demonstrated that mortality salience increased stereotyping of Germans. In Study 2, it increased participants' tendency to generate more explanations for stereotype-inconsistent than stereotype-consistent gender role behavior. In Study 3, mortality salience increased participants' liking for a stereotype-consistent African American and decreased their liking for a stereotype-inconsistent African American; control participants exhibited the opposite preference. Study 4 replicated this pattern with evaluations of stereotype-confirming or stereotype-disconfirming men and women. Study 5 showed that, among participants high in need for closure, mortality salience led to decreased liking for a stereotype-inconsistent gay man.

Stereotypes and terror management: evidence that mortality salience enhances stereotypic thinking and preferences

If stereotypes function to protect people against death-related concerns, then mortality salience should increase stereotypic thinking and preferences for stereotype-confirming individuals. Study 1 demonstrated that mortality salience increased stereotyping of Germans. In Study 2, it increased participants' tendency to generate more explanations for stereotype-inconsistent than stereotype-consistent gender role behavior. In Study 3, mortality salience increased participants' liking for a stereotype-consistent African American and decreased their liking for a stereotype-inconsistent African American; control participants exhibited the opposite preference. Study 4 replicated this pattern with evaluations of stereotype-confirming or stereotype-disconfirming men and women. Study 5 showed that, among participants high in need for closure, mortality salience led to decreased liking for a stereotype-inconsistent gay man.

The effect of midazolam on the modality-match effect in implicit memory

Prominent theories of implicit memory claim that perceptual processes play a central role in implicit memory. The modality-match effect, the finding that priming is greater when the modality of stimulus presentation matches at study and test, provides the central evidence for these approaches. In this paper we use the benzodiazepine, midazolam, to explore the nature of the modality-match effect in implicit memory. We compared the modality-match effect in a midazolam and a saline (i.e., a placebo) condition. Our experimental results demonstrate that the modality-match effect is diminished substantially in a midazolam condition even though components of priming are preserved. Given the empirically-validated assumption that midazolam minimizes explicit memory, these results suggest that there exist components of implicit memory that are not mediated by perceptual processes and raise questions about the generality of prominent theories of implicit memory.

Terror management and meaning: evidence that the opportunity to defend the worldview in response to mortality salience increases the meaningfulness of life in the mildly depressed

Previous terror management research has demonstrated that mildly depressed participants show a greater increase in worldview defense in response to reminders of their mortality than do nondepressed participants. Because the cultural worldview is posited to provide a meaningful conception of life, we hypothesized that mildly depressed participants who defend their worldview in response to mortality salience (MS) would increase their perception that the world is meaningful. A preliminary study first examined the Kunzendorf No Meaning Scale as a measure to assess perceptions of meaning. In the primary study, mildly depressed and nondepressed participants contemplated their own mortality or a neutral topic, evaluated two targets in a manner that either allowed them to defend their worldview or that did not, and then completed the Kunzendorf No Meaning Scale. As predicted, mildly depressed participants who had the opportunity to defend their worldview in response to mortality salience reported greater meaning in life than did mildly depressed participants who did not have the opportunity to defend their worldview, or mildly depressed participants not exposed to mortality salience. Implications for understanding and treating depression are briefly discussed.

Terror management and aggression: evidence that mortality salience motivates aggression against worldview-threatening others

The hypothesis that mortality salience (MS) motivates aggression against worldview-threatening others was tested in 4 studies. In Study 1, the experimenters induced participants to write about either their own death or a control topic, presented them with a target who either disparaged their political views or did not, and gave them the opportunity to choose the amount of hot sauce the target would have to consume. As predicted, MS participants allocated a particularly large amount of hot sauce to the worldview-threatening target. In Studies 2 and 3, the authors found that following MS induction, the opportunity to express a negative attitude toward the critical target eliminated aggression and the opportunity to aggress against the target eliminated derogation. This suggests that derogation and aggression are two alternative modes of responding to MS that serve the same psychological function. Finally, Study 4 showed that MS did not encourage aggression against a person who allocated unpleasant juice to the participant, supporting the specificity of MS-induced aggression to worldview-threatening others.

Terror management and aggression: evidence that mortality salience motivates aggression against worldview-threatening others

The hypothesis that mortality salience (MS) motivates aggression against worldview-threatening others was tested in 4 studies. In Study 1, the experimenters induced participants to write about either their own death or a control topic, presented them with a target who either disparaged their political views or did not, and gave them the opportunity to choose the amount of hot sauce the target would have to consume. As predicted, MS participants allocated a particularly large amount of hot sauce to the worldview-threatening target. In Studies 2 and 3, the authors found that following MS induction, the opportunity to express a negative attitude toward the critical target eliminated aggression and the opportunity to aggress against the target eliminated derogation. This suggests that derogation and aggression are two alternative modes of responding to MS that serve the same psychological function. Finally, Study 4 showed that MS did not encourage aggression against a person who allocated unpleasant juice to the participant, supporting the specificity of MS-induced aggression to worldview-threatening others.

Suppression, accessibility of death-related thoughts, and cultural worldview defense: exploring the psychodynamics of terror management

Previous research has shown that after a mortality-salience (MS) treatment, death thought accessibility and worldview defense are initially low and then increase after a delay, suggesting that a person's initial response to conscious thoughts of mortality is to actively suppress death thoughts. If so, then high cognitive load, by disrupting suppression efforts, should lead to immediate increases in death thought accessibility and cultural worldview defense. Studies 1 and 2 supported this reasoning. Specifically, Study 1 replicated the delayed increase in death accessibility after MS among low cognitive load participants but showed a reversed pattern among participants under high cognitive load. Study 2 showed that, unlike low cognitive load participants, high cognitive load participants exhibited immediate increase in pro-American bias after MS. Study 3 demonstrated that worldview defense in response to MS reduces the delayed increase in death accessibility. Implications of these findings for understanding both terror management processes and psychological defense in general are discussed.

Suppression, accessibility of death-related thoughts, and cultural worldview defense: exploring the psychodynamics of terror management

Previous research has shown that after a mortality-salience (MS) treatment, death thought accessibility and worldview defense are initially low and then increase after a delay, suggesting that a person's initial response to conscious thoughts of mortality is to actively suppress death thoughts. If so, then high cognitive load, by disrupting suppression efforts, should lead to immediate increases in death thought accessibility and cultural worldview defense. Studies 1 and 2 supported this reasoning. Specifically, Study 1 replicated the delayed increase in death accessibility after MS among low cognitive load participants but showed a reversed pattern among participants under high cognitive load. Study 2 showed that, unlike low cognitive load participants, high cognitive load participants exhibited immediate increase in pro-American bias after MS. Study 3 demonstrated that worldview defense in response to MS reduces the delayed increase in death accessibility. Implications of these findings for understanding both terror management processes and psychological defense in general are discussed.

Do low-risk prenatal patients really need a screening glucose challenge test?

BACKGROUND

It is common practice to routinely screen pregnant women for gestational diabetes. The screening technique typically used is the 1-hour 50-g oral glucose tolerance test (OGTT), with a subsequent 3-hour 100-g OGTT for women whose 1-hour test was positive. This process can be both time-consuming and inconvenient for patients. Additionally, its sensitivity and specificity are estimated to be 70% and 87% respectively, and data about the effect of screening and treatment on low-risk pregnancy outcomes are limited. The objective of this study was to reassess the value of routine screening of all pregnant patients with a 1-hour glucose challenge test.

METHODS

At a university-based family practice center with a predominantly low-risk population, a retrospective analysis was performed of all patients (n = 595) who received prenatal care and gave birth between January 1988 and December 1993. Among women in whom gestational diabetes was diagnosed on the basis of glucose tolerance testing, we identified those with risk factors for the disease, and examined whether a selective screening program based on risk factors alone would have resulted in correct diagnoses of gestational diabetes.

RESULTS

Of the 595 patients, 544 (91.4%) were screened with a 1-hour 50-g OGTT. This initial screening test was positive in 76 women (12.8%). Of these, 58 (76.3%) then had a 3-hour 100-g OGTT, and 13 received a diagnosis of gestational diabetes. Nine of these 13 women had risk factors for gestational diabetes. We determined that less than 1% of prenatal patients without risk factors for gestational diabetes were ultimately found to have gestational diabetes.

CONCLUSIONS

Screening with a 1-hour 50-g OGTT only those women who have identifiable risk factors for gestational diabetes is a reasonable approach to identifying the disease in a low-risk population. All pregnant women should have a thorough history taken to determine whether they have risk factors for gestational diabetes.

Terror management and cognitive-experiential self-theory: evidence that terror management occurs in the experiential system

The authors hypothesized, on the basis of terror management theory and cognitive-experiential self-theory, that participants in an experiential mode of thinking would respond to mortality salience with increased worldview defense and increased accessibility of death-related thoughts, whereas participants in a rational mode would not. Results from 3 studies provided convergent evidence that when participants were in an experiential mode, mortality salience produced the typical worldview defense effect, but when participants were in a rational mode it did not. Study 4 revealed that mortality salience also led to a delayed increase in the accessibility of death-related thoughts only when participants were in an experiential mode. These results supported the notion that worldwide defense is intensified only if individuals are in an experiential mode when considering their mortality. Discussion focuses on implications for understanding terror management processes.

Therapeutic efficacy and tolerability of brodimoprim in comparison with doxycycline in acute sinusitis in adults

OBJECTIVE

To compare efficacy and tolerability of brodimoprim tablets with doxycycline tablets in adults with acute sinusitis.

DESIGN

Open, randomized, controlled phase III study, with parallel groups.

PATIENTS

Of the 70 enrolled patients, 56 adults of both sexes with a mean age of 33 years were evaluable. STUDY DRUGS: One brodimoprim 200mg tablet or one doxycycline 100mg tablet was administered once daily for 8 to 12 days (on the first treatment day all patients received the loading dose consisting of 2 tablets of the corresponding compound).

CLINICAL OUTCOME

In the brodimoprim group 96.4% of the patients were judged cured/improved; in the doxycycline group 96.2%. BACTERIOLOGICAL OUTCOME: Eradication of the causative pathogen/s was achieved in 87.5% of the patients treated with brodimoprim and in 60% of the doxycycline group. SAFETY OUTCOME: Tolerability was judged as very good/good in 89.7% of the patients treated with brodimoprim and in all patients receiving doxycycline. Gastrointestinal skin, CNS and various other reactions were reported by 13 patients; 3 of them had to discontinue treatment. Discontinuation of therapy: 8 more patients withdrew from the study due to inactivity of the compound or reasons unrelated to the drugs.

CONCLUSION

Brodimoprim was shown to be effective in the treatment of acute sinusitis in adults, its efficacy being equal to that of doxycycline. The assessments showed a positive clinical response to the medication in 96.4% of the patients treated with brodimoprim and 96.2% of the patients taking doxycycline. Both compounds were well tolerated and all side effects were of mild nature and reversible.

Three-dimensional dose mapping from gamma knife treatment using a dosimeter gel and MR-imaging

A new method has been investigated for the mapping of dose distributions in three dimensions delivered by the Leksell gamma knife. The irradiation unit is used to selectively treat small volumes in the brain with single high doses of ionising radiation--a treatment procedure known as radiosurgery. The dosimetry method investigated utilises a dosimeter gel consisting of ferrous sulphate solution and agarose which is, prior to irradiation, loaded into a cavity in a spherical phantom. Chemical changes induced in the gel by the radiation are measured by means of an MR-scanner. This imaging method permits rapid evaluation of the dose distribution in an irradiated volume. It thus offers a potential verification of individual radiation intracranial target treatment regimes as well as quality assurance measurements, assuming that the precision and accuracy of the dose mapping are adequate. The dose and its distribution registered by the gel dosimeter, in this initial experiment, are in good agreement with corresponding computed data obtained with the KULA treatment planning system of the gamma knife. The gel has thus the potential of being an attractive alternative dose mapping method to those used at present in radiosurgery, i.e. radiographic film and small ionisation chambers. The precision of the dosimeter gel is, however, not yet sufficient high to be used as a basic dosimetry system for the gamma knife.

Evidence for the induction of protease activity on cultured tumour cells as a consequence of implantation into nude mice

We have studied the enzymic status of a tumour associated protease on human colonic tumour cells cultured in vitro and grown in vivo in nude mice. The cultured tumour cells lack this protease. The cells of the tumour colonies in the mice possess active enzyme although the tissue contains an inhibitor capable of inactivating this tumour cell protease. The evidence indicates that the induction of this protease on the tumour cells is a consequence of implantation of the cultured cells into the nude mouse.

The status of trypsin-like enzymes in squamous-cell carcinoma of the head and neck region

The activity of two proteases associated with tumour cells was studied using frozen sections of squamous-cell carcinoma and fluorescent probes for the enzymes. Four fluorescent probes were used to define the enzymic status of guanidinobenzoatase on the surface of the squamous carcinoma cells. Each of four probes demonstrated the location of cells possessing inactive guanidinobenzoatase, whereas adjacent cells of the same tumour exhibited active enzyme. It was shown that the inactive form of the enzyme was an inhibitor-enzyme complex that could be dissociated. In contrast, all of the squamous carcinoma cells possessed active trypsin-like enzymes that were recognised by fluorescent aprotinin molecules. The observed variation in enzymic status of these two tumour-associated enzyme systems is discussed in the context of a possible biological control mechanism for cell migration.

Inhibition of a protease associated with tumour cells and the probable mechanism of regulation of this interaction in vivo

The regulation of activity of a protease on the surface of human colonic tumour cells implanted in nude mice has been studied. A synthetic fluorescent probe was used to locate cells possessing active guanidinobenzoatase in frozen sections of tumour bearing tissues. These studies demonstrated the presence of intracellular protein inhibitors of guanidinobenzoatase which could be extracted in isotonic saline and transferred to the outer surface of the tumour cells. This study showed that the inhibition of guanidinobenzoatase was pH dependent and that the tumour cell may regulate the activity of its surface guanidinobenzoatase by exporting lactic acid.

[Histologic changes in the normal bladder wall following fractionated irradiation--an animal experimental study]

The histopathologic alterations of the bladder wall were investigated in 180 rabbits irradiated with different fractionations and total focal doses. Animals sacrificed on week after the end of irradiation showed alterations of the urothelium (desquamation, increased polymorphism of nuclei vacuolizations) as well as oedematous and hyperemic reactions in submucosa and muscularis. These alterations became stronger when the single and total focal dose and the ret value were increased. Animals sacrificed three to six months after the end of irradiation showed dystrophic-sclerotic processes as well as vascular obliterations in the submucosa and muscularis. The alterations were only clearly visible in case of a total focal dose of at least 30 Gy. With regard to a minimization of histopathologic alterations of the bladder wall, a fractionation of 1.5 Gy per day has to be considered as favorable in radiotherapy of the carcinoma of the urinary bladder.

Stereotactic radiation therapy of intracranial lesions. Methodologic aspects

A technique for stereotactic radiation therapy of cerebral tumours and arteriovenous malformations using a linear accelerator (6 MV photons) is proposed. Treatment relies on a fixation system that permits a precise use of the coordinates estimated at stereotactic angiography or stereotactic computed tomography. The field of treatment can be exactly outlined in the CT images during repeat examinations, thus facilitating the recognition of changes induced by radiation. The system also allows the extent of the arteriovenous malformation, as seen at angiography, to be accurately traced in the CT sections thus enabling evaluation of possible radiation damage to surrounding brain structures. The precision of the method as well as its hypothetical merits and disadvantages are discussed. The number of patients treated is still small and the follow-up time is too short in the majority of cases to allow definite conclusions. Examples of preliminary results are given.