Breast Density and Risk of Interval Cancers: The Effect of Annual Versus Biennial Screening Mammography Policies in Canada

Regular screening mammography reduces breast cancer mortality. However, in women with dense breasts, the performance of screening mammography is reduced, which is reflected in higher interval cancer rates (ICR). In Canada, population-based screening mammography programs generally screen women biennially; however, some provinces and territories offer annual mammography for women with dense breast tissue routinely and/or on recommendation of the radiologist. This study compared the ICRs in those breast screening programs with a policy of annual vs. those with biennial screening for women with dense breasts. Among 148,575 women with dense breasts screened between 2008 to 2010, there were 288 invasive interval breast cancers; screening programs with policies offering annual screening for women with dense breasts had fewer interval cancers 63/70,814 (ICR 0.89/1000, 95% CI: 0.67-1.11) compared with those with policies of usual biennial screening 225/77,761 (ICR 1.45 /1000 (annualized), 95% CI: 1.19-1.72) i.e. 63% higher (p = 0.0016). In screening programs where radiologists' screening recommendations were able to be analyzed, a total of 76,103 women were screened, with 87 interval cancers; the ICR was lower for recommended annual (65/69,650, ICR 0.93/1000, 95% CI: 0.71, 1.16) versus recommended biennial screening (22/6,453, ICR 1.70/1000 (annualized), 95%CI: 0.70, 2.71)(p = 0.0605). Screening program policies of annual as compared with biennial screening in women with dense breasts had the greatest impact on reducing interval cancer rates. We review our results in the context of current dense breast notification in Canada.

Comparison of energy intensity of different food materials and their energy content

The energy embodied in different food materials refers to energy input in its production in agricultural and or livestock farms in direct or indirect forms. In this work, it is intended to make a comparison among the energy intensity of cereals, cow milk and bull meat production. The study was performed to evaluate the energy flow in dairy farms and related feedstuff production farms in the northwest of Iran. According to the results, the energy intensity of wheat and maize corn is 4.35 and 9.19 MJ kg-1 , respectively, while they have the energy content of nearly 15 MJ kg-1 as food materials with almost 15% moisture content. The energy intensity of ECM milk was calculated to be 5.81 MJ kg-1 , while it has the energy content of only 3.15 MJ kg-1 , with a water content of 87.2%. As for boneless meat, for a bull mass of up to 400 kg, the energy intensity was 75.4 MJ kg-1 while it was 103.8 MJ kg-1 for bulls up to 700 kg body mass. It is much higher than for milk and cereals, while, it has only 8.8 MJ kg-1 energy content for the fresh state with nearly 70% water content. A comparison of these energy values indicates the high use of resources, harmful to the environment, for products of animal origin, especially for meat. This issue will get worse with an increasing demand for animal products in the future. Therefore, replacing bull meat with less energy-intensive food materials such as cereals and other meat, e.g. poultry, could reduce pressure on the environment.

Aktualisierung der S2k-Leitlinie zur Diagnostik, Therapie und Metaphylaxe der Urolithiasis (AWMF Registernummer 043-025)

Die Zunahme des medizinischen Wissens, technische Neuerungen gemeinsam mit demographischem Wandel stellen eine Herausforderung an die Neukonzeption von Leitlinien und klinischen Studien dar. Die vorliegende S2k-Leitlinie, die sich ausschließlich mit Nieren- und Harnleitersteinen beschäftigt, soll die Behandlung von Harnsteinpatienten in Klinik und Praxis unterstützen, aber auch Patienteninformationen zur Urolithiasis geben. Die zunehmende interdisziplinäre Zusammenarbeit in der Steintherapie zeigt sich auch an der Anzahl beteiligter Fachgruppen und Arbeitsgemeinschaften in der Erstellung des neuen Leitlinienupdates. Die vorliegende, aus einem interdisziplinären Konsensusprozess hervorgegangene S2k-Leitlinie stellt die aktuellen Empfehlungen praxisnah dar und gibt Entscheidungshilfen für Diagnostik‑, Therapie- und Metaphylaxemaßnahmen auf Basis von Expertenmeinungen und verfügbaren Evidenzgrundlagen aus der Literatur.

Human and Bovine Plasminogen-Free Thrombin, Purified by Means of Gel Filtration and Ion Exchange Chromatography

A simple method for preparation of plasminogen-free human and bovine thrombin is described.

Crude thrombin was prepared in the usual manner from oxalated plasma by means of adsorption on BaSO4, elution with trisodium citrate and activating the eluate from BaSO4 with tissue thromboplastin.

This crude thrombin was purified by means of gel-filtration and chromatography on CM-Sephadex A-50.

The gel-filtration was performed on three types of Sephadex, G-75, G-50, and G--25. By means of Sephadex G-75 the thrombin was well separated from the main part of inert protein and this type of Sephadex was used for the purification in large-scale. Separation of thrombin from protein of higher molecular weight was also obtained with Sephadex G-50 but not with Sephadex G-25 indicating a molecular weight of thrombin between 4000 and 10,000.

The importance of using an elution buffer of sufficient high ionic strength for gel-filtration is shown. A great deal of the thrombin was adsorbed to the Sephadex if the gel-filtration was performed at a too low ionic strength.

The final preparation contained 30,000 NIH units of thrombin per mg tyrosin and no detectable plasminogen.

The commercial preparation “Topostasine” was also purified in the same manner, but the plasminogen content in “Topostasine” was high and could not be completely separated from thrombin.

Assay of the Antifibrinolytic Activity in Human Plasma by Means of the Lysis Time Method

A one-stage lysis time method to determine the total antifibrinolytic activity of human plasma is described. Purified fibrinogen, thrombin, plasminogen, and urokinase were used in the test system. The necessity of using a high plasminogen concentration compared with the urokinase concentration is pointed out. The concentration of the reagents has to be carefully standardized.

A straight line will be obtained in a semi-logarithmic system when plasma dilutions are plotted against. The validity of this relation is investigated when the concentrations of plasminogen, fibrinogen, and urokinase are varied. It is also shown that this relation is valied when the antifibrinolytic activity is increased postoperatively and after delivery.

The antifibrinolytic activity is expressed as a percentage of the activity of a standard plasma. The standard plasma does not change its antifibrinolytic activity during storage at —20° C for at least three months.

The error of the method is about 2%.

Finally, the present report includes an experiment, the result of which makes it probable that the main action of plasma tested in this one-stage lysis time system is an antiplasmin activity.

Urokinase Activation of Plasminogen and Spontaneous Inactivation of the Plasmin Formed

The kinetics of the activation of plasminogen into plasmin with urokinase and the inactivation rate of the plasmin formed are studied.

As a first order reaction is obtained with low plasminogen concentrations and a zero-order reaction is obtained with high concentrations, the activation seems to follow the Michaelis-Menten’s law. The reaction does not go to completion, however. Different activity levels, which are dependent on the urokinase concentration, can be observed.

The activation rate increases with temperature. A maximum can be seen at about 42° C.

Between 4° C and 15° C, the inactivation of the plasmin formed is minimal, but it increases rapidly at higher temperatures. The inactivation follows approximately a first order reaction with respect to time. If the plasminogen concentration is low, the over-all reaction will be that of two consecutive first order reactions.

Theoretical Basis and Standardization of the One-Stage Lysis Time Method for Determination of Urokinase

The theroretical basis for the use of a one-stage lysis time method for determination of urokinase is outlined. The calculations are based on experiments with purified plasminogen, fibrinogen, and thrombin preparations.

The following correlation between the lysis time and the urokinase, plasminogen, and fibrinogen concentrations was found :

This correlation is valid onyl for a certain range of plasminogen and urokinase concentrations. This validity has been verified experimentally.

A method has been proposed for determination of urokinase in which the curve of the standard graph always is rectilinear and has the slope –0.5. The method is very sensitive and its accuracy is great.

Plasminogen Assay by Means of the Lysis Time Method

The lysis time method for the determination of plasminogen has been investigated using plasminogen-free thrombin and fibrinogen preparations.

The experiments have shown that the lysis of a fibrin clot is the result of two consecutive reactions: the formation of fibrin which proceeds as a first order reaction and the degradation of fibrin which proceeds as a zero order reaction. Plasminogen is activated in a separate reaction. If the rate of the fibrin formation is much greater than the rate of degradation, the lysis of the fibrin clot is approximately of zero order in fibrin. The lysis time will then be inversely proportional to the plasmin concentration and proportional to the fibrinogen concentration. In a double logaritmic system the correlation between lysis time and plasmin activity is a straight line with a slope of 135°.

Plasminogen is rapidly activated with streptokinase. Maximal activation is obtained only with a certain streptokinase concentration. Higher concentrations inactivate plasmin and with lower concentrations, the maximal activity is never reached. A spontaneous inactivation is seen after about 30 minutes. With urokinase, a higher maximal plasminogen activity is obtained than with streptokinase. Urokinase in higher concentrations does not inactivate plasmin.

A standard assay for determination of plasminogen by the lysis time method has been worked out and is based on these results.

Determination of Plasminogen in Human Plasma by the Lysis Time Method

A one-stage lysis time system containing fibrinogen, streptokinase, thrombin, and a known, small amount of plasminogen was used to determine plasminogen in plasma.

The known amount of plasminogen was added to the system in order to keep the lysis times relatively short when a highly diluted plasma was tested. High dilutions of plasma were used to reduce the influence of the plasma inhibitors.

The calculation of the plasminogen concentration was made on the basis of the correlation: “plasminogen = fibrinogen/lysis time” which was valid in the system. The method allowed determination of plasminogen in plasma with varying fibrinogen concentrations, as the fibrinogen concentration in plasma was considered in the calculation.

The presence of “spontaneous” plasmin activity in the plasma did not influence the plasminogen determination. Estimated by this method, the plasminogen content in plasma from 32 blood donors aged 25-45 years was 13.1 ±2.4 casein u/ml. The error of a single determination was 0.3 casein u/ml. The plasminogen content in plasma, determined with the present method, is about 3-4 times higher than the content found when a caseinolytic method is used.

Compensation of thermal constraints along a natural environmental gradient in a Malagasy iguanid lizard (Oplurus quadrimaculatus)

Physiological or behavioural adjustments are a prerequisite for ectotherms to cope with different thermal environments. One of the world's steepest environmental gradients in temperature and precipitation can be found in southeastern Madagascar. This unique gradient allowed us to study the compensation of thermal constraints in the heliothermic lizard Oplurus quadrimaculatus on a very small geographic scale. The lizard occurs from hot spiny forest to intermediate gallery and transitional forest to cooler rain forest and we investigated whether these habitat differences are compensated behaviourally or physiologically. To study activity skin temperature (as proxy for body temperature) and the activity time of lizards, we attached temperature loggers to individuals in three different habitats. In addition, we calculated field resting costs from field resting metabolic rate to compare energy expenditure along the environmental gradient. We found no variation in activity skin temperature, despite significant differences in operative environmental temperature among habitats. However, daily activity time and field resting costs were reduced by 35% and 28% in the cool rain forest compared to the hot spiny forest. Our study shows that O. quadrimaculatus relies on behavioural mechanisms rather than physiological adjustments to compensate thermal differences between habitats. Furthermore, its foraging activity in open, sun exposed habitats facilitates such a highly effective thermoregulation that cold operative temperature, not energetically expensive heat, presents a greater challenge for these lizards despite living in a hot environment.

[Carefully conducted preanalytic and postanalytic procedures for urine samples. Often neglected in urolithiasis treatment]

Particularly in the urological consultation sessions collection of 24 h urine samples is required to evaluate the metabolic risk factors for urolith formation. To ensure a yield from urinalysis of sufficiently high quality and to minimize the number of potential error sources, correctly performed preanalytical procedures are required. If certain basic quality criteria for the collection procedures are not being followed false data can be determined and the clinical interpretation based on that analysis will result in a wrong rating of the true metabolic status of patients. This article provides practical, feasible and proven solutions in an encouraging, motivating and clear way to ensure that at least the most important steps for a correct urine collection are being taken. The preanalytical requirements for the determination of other urinary parameters which are not in the direct focus of urolithiasis treatment will not be covered by this article.

Short communication: Dipping efficiency and teat dip residues in milk using an automatic dipping system

Prototypes of the automatic-dipping system Apollo were tested with the IQ milking cluster (GEA Farm Technologies GmbH, Bönen, Germany) to determine the teat-dip residues in the milk and the dipping performance (number of dipped teats) of the system compared with manual (hand) dipping. A laboratory trial and a field trial at a dairy farm were performed to determine the iodine level in the milk when an iodine-based teat dip was used. In the laboratory trial, the mean difference between the 53 paired samples (sampling upstream and downstream of the cluster) was 18.9 ± 3.18 μg of iodine/kg. A field trial at a 300-cow commercial dairy farm consisted of taking 2 sets of individual cow milk samples 6 wk apart. Three weeks before the second test day, the iodine-based teat dip was replaced by an iodine-free teat dip. The mean difference between the 2 sets of 55 samples was 25.1 ± 5.22 μg/kg. Compared with manually applying an iodine-based teat dip, the increase in the iodine content resulting from the use of the tested cluster with automatic dipping was very low and would not be an issue of food safety. The dipping performance tests were completed on the same 300-cow commercial dairy farm as the field iodine level trial was performed. In total, 4,541 teats from 307 cows were observed on 4 consecutive days, showing a 91.6 ± 1.3% success rate.

Seasonal and diel variations of ammonia and methane emissions from a naturally ventilated dairy building and the associated factors influencing emissions

Understanding seasonal and diel variations of ammonia (NH3) and methane (CH4) emissions from a naturally ventilated dairy (NVD) building may lead to develop successful control strategies for reducing emissions throughout the year. The main objective of this study was to quantify seasonal and diel variations of NH3 and CH4 emissions together with associated factors influencing emissions. Measurements were carried out with identical experimental set-up to cover three winter, spring and summer seasons, and two autumn seasons in the years 2010, 2011, and 2012. The data from 2010 and 2011 were used for developing emission prediction models and the data from 2012 were used for model validation. The results showed that NH3 emission varied seasonally following outside temperature whereas CH4 emission did not show clear seasonal trend. Diel variation of CH4 emission was less pronounced than NH3. The average NH3 and CH4 emissions between 6a.m. and 6p.m. were 66% and 33% higher than the average NH3 and CH4 emissions between 6p.m. and 6a.m., respectively for all seasons. The significant relationships (P<0.0001) between NH3 and influencing factors were found including outside temperature, humidity, wind speed and direction, hour of the day and day of the year. The significant effect (P<0.0001) of climate factors, hours of the day and days of the year on CH4 emission might be directly related to activities of the cows.

[Stress-related alteration of urine compositions: idiopathic CaOx stone formers, patients with chronic inflammatory bowel disease (CIBD) and healthy controls]

BACKGROUND

Increased emotional stress in everyday life influences the way of living and metabolism of people living in developed countries. Contemporaneously, the incidence and prevalence of urolithiasis rises. Does a pathogenetically relevant relationship exist between chronic stress burden and permanently altered urinary composition?

PATIENTS AND METHODS

The influence of chronic stress burden on urine composition and risk of urinary calcium oxalate (CaOx) stone formation was, for the first time, comprehensively investigated in 29 healthy controls (CG), 29 idiopathic CaOx stone formers (SF) and 28 patients suffering from chronic inflammatory bowel disease (CIBD). After 4 days with standardized nutrition, 24-h urine was collected. Extensive urinalysis was performed and APCaOx index calculated. Evaluation of subjective stress level was carried out by using the standardized and well-established questionnaire Trierer Inventar zur Beurteilung von chronischem Stress (TICS). The concentration values of the urinary parameters as well as the APCaOx values were linearly correlated with the stress scores obtained from the different items of the TICS. A significance level p≤0.05 was considered to indicate statistical significance.

RESULTS

The mean APCaOx indices amounted to 0.8±0.3 in CG, 1.2±0.7 in SF and 1.9±1.2 in CIBD. The increased APCaOx in SF mainly results from relatively increased Ca and oxalate excretions, whereas in CIBD this also results from reduced urinary excretions of citrate and Mg as well as reduced 24-h urinary volumes. The calculation of linear correlation coefficients between a TICS stress dimension and a concentration value of a urinary parameter or APCaOx results in r values not exceeding 0.600. However, some of these correlations are statistically highly significant. In SF only one combination with Ca was observed, while in CIBD in contrast a number of combinations, in particular including Na, was obtained. In CG direct statistical relationships between stress burden and citrate as well as Mg exist. In this group, increased stress burden is associated with increased inhibitory potential to prevent CaOx stone formation.

CONCLUSION

In the investigated study groups, differently complex relationships between amount of stress burden and risk of CaOx stone formation were observed, however, without obvious physicochemical principle(s). In some individuals, stress can be associated with a significantly stress-related alteration of urinary composition towards increased CaOx stone formation risk. The results obtained from the CIBD group allow for the first time a conclusive link between emotional stress and inflammatory activity on the one hand and inflammatory activity and metabolic risk constellation of CaOx stone formation on the other hand.

GHG emissions during the storage of rough pig slurry and the fractions obtained by mechanical separation

Emissions of methane (CH4), carbon dioxide (CO2), nitrous oxide (N2O) and ammonia (NH3) during the storage of rough pig slurry and the fractions (solid and liquid) obtained by mechanical separation were investigated in a laboratory-scale study. Manures were stored for a period of 30 days in open vessels (1500 cm3 capacity) within a climate-controlled room which was kept at 25 ± 0.2°C. Gaseous emissions were determined with the dynamic chamber method by infrared photoacoustic detection. The main GHG emission from the liquid manures was CH4. CH4 losses from both liquid and solid fractions together were 3% higher than from the rough slurry. CO2 losses from both liquid and solid fractions together increased by 10% compared with rough pig slurry. Appreciable N2O fluxes were only measured from the solid fraction. Combining the losses during the storage of both liquid and solid fraction, they resulted in reduced NH3 emissions compared with the storage of the rough pig slurry. Evidence from the present study suggests that mechanical separation of pig slurry has the potential to increase up to 25% the emission of CO2-equivalents to the atmosphere during the storage of the separated fractions if compared with the rough slurry.

Spinal cord stimulation in the treatment of chronic critical limb ischemia

This paper reviews the clinical experience and proposed working mechanisms of spinal cord stimulation (SCS) in the treatment of chronic critical limb ischemia (CCLI). SCS appears to provide a significant long-term relief of ischemic pain and to improve healing of small ulcers, most likely due to effects on the nutritional skin blood flow. Despite these observations, randomized trials were not able to show limb salvage. Assessment of the microcirculatory skin blood flow, by means of transcutaneous oxygen pressure measurements and videocapillaromicroscopy, is necessary to evaluate the remaining microcirculatory reserve capacity likely to be exploited by SCS and to help identify patients that will benefit most from this treatment and in whom stimulation could lead to limb salvage.

A multicenter, randomized, double-blind, placebo-controlled, dose-finding trial of a long-acting formulation of octreotide in promoting weight loss in obese adults with insulin hypersecretion

OBJECTIVE

To compare changes in weight in obese patients who received long-acting octreotide (octreotide LAR) at one of three dose levels (20, 40, or 60 mg) or placebo over 6 months and to identify the lowest dose of octreotide LAR that safely achieved optimal weight loss.

DESIGN

Randomized, double-blind, placebo-controlled trial of octreotide LAR at three dose levels.

PATIENTS

A total of 172 adults (28 men and 144 women) with at least moderate obesity (body mass index (BMI) range 30-65 kg/m2) and evidence of insulin hypersecretion were enrolled. Patients were predominantly either Caucasian (50.0%) or African American (45.3%). The mean age (38 +/- 11 year), weight (110.7 +/- 23 kg), and BMI (39.8 +/- 6.5 kg/m2) were similar across the four treatment groups.

MEASUREMENTS

Efficacy measures included weight, BMI, fasting serum glucose; triglycerides; percentage of total body fat and abdominal fat as measured by dual-energy X-ray absorptiometry; skin fold thickness; waist-to-hip circumference; leptin; percentage of carbohydrates, fat, and protein ingested; nutritional evaluation (including dietary analysis--3-day food record); quality of life (QoL; using the Impact of Weight on Quality of Life-Lite); Beck Depression Inventory; and Carbohydrate Craving Questionnaire. Safety measures included medical history, vital signs, physical examinations, hematology, blood chemistries, thyroid function tests, hemoglobin A1c, gallbladder ultrasound, electrocardiograms, and adverse events.

RESULTS

After 6 months of treatment, patients receiving 40 or 60 mg of octreotide LAR experienced statistically significant weight loss compared to baseline, with mean differences from placebo in percent weight change of -1.98 and -1.87%, respectively. This finding was accompanied by statistically significant mean decreases in BMI compared to baseline, that is, a mean decrease of 0.73 and 0.79 kg/m2 for the 40 and 60 mg treatment arms, respectively. The observed weight loss was progressive during the 6-month treatment in the two higher dose groups. The lowest dose to reach statistical significance in weight loss after 6 months' treatment was 40 mg. Post hoc analysis revealed a 3.5-3.8% weight loss at month 6 in the two higher dose groups among Caucasian patients having insulin secretion greater than the median of the cohort, defined as CIR(gp) (corrected insulin response at the glucose peak) > or = 1.43. There were no statistically significant changes in QoL scores, body fat, leptin concentration, Beck Depression Inventory, or macronutrient intake. Mean changes of blood glucose AUC(0-180 min) during an oral glucose tolerance test in patients taking octreotide LAR were 39-40 mg/dl h higher than those on placebo. A total of 7-21% of the patients taking octreotide LAR reached a 5% or greater decrease in body weight from Baseline, compared to 11% for the placebo group. This was not statistically significant. The most common adverse events included diarrhea, headache, cholelithiasis, nausea, and abdominal pain.

CONCLUSION

Octreotide LAR given at 40 or 60 mg resulted in statistically significant weight loss. A post hoc analysis stratifying patients by race and CIR(gp) indicated that Caucasian patients with the greater degree of insulin hypersecretion appeared to derive the most benefit from treatment. The observed safety profile was consistent with the known effects of octreotide from previous studies.

Diagnosis and metaphylaxis of stone disease. Consensus concept of the National Working Committee on Stone Disease for the upcoming German Urolithiasis Guideline

This review draws the recent state of the art in metabolic diagnosis and metaphylaxis of stone disease. It is the basis for the consensus approval with the other medical societies and institutions in Germany involved in the guideline process of the new "Urolithiasis Guideline". The German Working Committee on Stone Disease reviewed critically the current literature in the field of urolithiasis-including the existing German and EAU-Guidelines as well as the Conference Book of the First International Consultation on Stone Disease. As far as possible the references were rated according to the EBM criteria. On this basis the expert group discussed all pathways and statements regarding the management of stone disease. The present review coincides with the consented guideline draft of the German Working Committee on Stone Disease. Occurrence of stone disease in the western world increases seriously. Modern lifestyle, dietary habits and overweight-problems of the affluent societies-emerge to be the important promoters of the "stone-boom" in the new millennium. This even affects children, whose stone prevalence is otherwise significantly less than that of adults. Criteria for the high risk group of stone formers were clearly defined. A diagnostic standard is formulated for the basic and the elaborate metabolic evaluation of a stone patient. Approximately 75% of all stone patients could anticipate stone recurrence with elementary reorientation of their lifestyle and dietary habits, summarized as general metaphylaxis. About 25% of the stone formers require additional pharmacological intervention to normalize their individual biochemical risk, precisely compiled for each stone type as specific metaphylaxis.

Alpha-fodrin as a putative autoantigen in Graves' ophthalmopathy

Alpha-fodrin, an intracellular organ-specific cytoskeleton protein is a recently identified autoantigen associated with Sicca- and Sjogren's syndrome (SS). SS frequently affects patients with Graves' ophthalmopathy (GO). We have therefore cloned and expressed the human recombinant 120-kDa fodrin-fragment. A sequential purification procedure was applied to isolate the recombinant protein. Using sera from patients with SS, the antigenicity of the purified fodrin fragment was demonstrated by immunoblotting. Sera from 144 patients with GO and 1200 blood donors were screened for the presence of anti-alpha-fodrin IgA and IgG antibodies by a newly developed ELISA using the human alpha-fodrin fragment as an autoantigen. In contrast to controls (<1% IgA only, P < 0.001) and to subjects with various autoimmune diseases (P < 0.001), alpha-fodrin antibodies were detected in 22% of patients with GO (n = 32). IgA and IgG antibodies were present in 21 (15%) and 14 (10%) GO subjects, respectively. A total of 45 patients with GO (31%) had at least one fodrin- or SS-antibody. GO patients with SS showed SS- and high titres of alpha-fodrin-antibodies. In GO patients, fodrin antibodies correlated with TPO- (P < 0.05) and SS-A (P = 0.002) antibodies. Thus, for the first time, antibodies reactive with fodrin are reported in patients with GO.

[Thio- and oxybarbiturates inhibit peristalsis in the Guinea-pig ileum in vitro]

INTRODUCTION

Inhibition of gastrointestinal motility by drugs used for anaesthesia or sedation in critically ill patients in the ICU is a major problem leading to various complications. Thus this study examines whether the thio- and oxybarbiturates thiopentone and pentobarbitone exert an inhibitory effect on intestinal peristalsis.

METHODS

Peristalsis in isolated segments of the guinea-pig small intestine was elicited by distension of the gut wall through a rise of intraluminal pressure and recorded via the intraluminal pressure changes associated with the aborally moving peristaltic contractions. Thiopentone and pentobarbitone (0.1 - 300 microM)-induced inhibition of peristalsis was reflected by an increase of the peristaltic pressure threshold (PPT).

RESULTS

Thiopentone (EC50 = 19,8 microM) and pentobarbitone (EC50 = 99.7 micro M) concentration-dependently increased the PPT. While the vehicle (saline) and 0.1 - 10 micro M thiopentone and pentobarbitone were without any effect on the PPT, 100 micro M caused a significant increase in PPT, and complete abolition of peristalsis occurred after 300 micro M thiopentone or pentobarbitone in all segments tested. Inhibition was reversed by changing the bath solution.

CONCLUSIONS

Thio- and oxybarbiturates inhibit intestinal peristalsis in the guinea-pig ileum. It is assumed that thiopentone and pentobarbitone affect propulsive peristalsis also in the human small intestine.

Evidence for microbunching "sidebands" in a saturated free-electron laser using coherent optical transition radiation

We report the first measurements of z-dependent coherent optical transition radiation (COTR) due to electron-beam microbunching at high gains ( >10(4)) including saturation of a self-amplified spontaneous emission free-electron laser (FEL). In these experiments the fundamental wavelength was near 530 nm, and the COTR spectra exhibit the transition from simple spectra to complex spectra ( 5% spectral width) after saturation. The COTR intensity growth and angular distribution data are reported as well as the evidence for transverse spectral dependencies and an "effective" core of the beam being involved in microbunching.

Pilot study of the practical relevance of a one-step test for prostate-specific antigen in capillary blood to improve the acceptance rate in the early detection program of prostate carcinoma

OBJECTIVE

Current studies have proven that early, organ-confined stages of prostate cancer can be diagnosed through screening based on PSA levels, thus reducing cancer mortality. Here we report about our experience using an innovative one-step test for PSA in capillary blood.

METHODS

The incubation time for a 50 microl blood sample with the indicator strip is 12 minutes until the qualitative visual results (<4.0 ng/ml or > or = 4 ng/ml) appear. In cooperation with urologists and accompanied by an extensive information campaign, the one-step test was made available free of charge to all men between the ages of 45 and 75 in all 28 pharmacies of our city (100,000 inhabitants).

RESULTS

The test's acceptance rate among the 2,119 participants between the ages of 45 and 75 years amounted to 13.0%. Fifteen percent of all the tests conducted showed a positive PSA result (> or = 4 ng/ml). Prostate carcinoma was histologically confirmed in 14 (0.66%) of the men, nine times in the early stage (T2) and five times in the clinical stage (T3), corresponding to an incidence of circa 650 cases per 100,000 men in the target age group.

CONCLUSIONS

This newly developed PSA test system can enhance the acceptance rate and effectiveness of medical check-ups for prostate cancer, because it is easy-to-use, cost-effective and accurate (specificity 81.3%, sensitivity 91.1%). The test should be always conducted by an experienced physician or pharmacist. It is not a substitute for a regular physical examination (DRE, TRUS, biopsy...).

Antigenic properties of the human immunodeficiency virus envelope during cell-cell fusion

Human immunodeficiency virus (HIV) fusion and entry involves sequential interactions between the viral envelope protein, gp120, cell surface CD4, and a G-protein-coupled coreceptor. Each interaction creates an intermediate gp120 structure predicted to display distinct antigenic features, including key functional domains for viral entry. In this study, we examined the disposition of these features during the fusion of HeLa cells expressing either HIV(HXB2) envelope (Env cells) or CXCR4 and CD4 (target cells). Cell-cell fusion, indicated by cytoplasmic dye transfer, was allowed to progress for various times and then arrested. The cells were then examined for reactivity with antibodies directed against receptor-induced epitopes on gp120. Analyses of cells arrested by cooling to 4( degrees )C revealed that antibodies against the CD4-induced coreceptor-binding domain, i.e., 17b, 48d, and CG10, faintly react with Env cells even in the absence of target cell or soluble CD4 (sCD4) interactions. Such reactivity increased after exposure to sCD4 but remained unchanged during fusion with target cells and was not intensified at the Env-target cell interface. Notably, the antibodies did not react with Env cells when treated with a covalent cross-linker either alone or during fusion with target cells. Immunoreactivity could not be promoted or otherwise altered on either temperature arrested or cross-linked cells by preventing coreceptor interactions or by using a 17b Fab. In comparison, two other gp120-CD4 complex-dependent antibodies against epitopes outside the coreceptor domain, 8F101 and A32, exhibited a different pattern of reactivity. These antibodies reacted with the Env-target cell interface only after 30 min of cocultivation, concurrent with the first visible transfer of cytoplasmic dye from Env to target cells. At later times, the staining surrounded entire syncytia. Such binding was entirely dependent on the formation of gp120-CD4-CXCR4 tricomplexes since staining was absent with SDF-treated or coreceptor-negative target cells. Overall, these studies show that access to the CD4-induced coreceptor-binding domain on gp120 is largely blocked at the fusing cell interface and is unlikely to represent a target for neutralizing antibodies. However, new epitopes are presented on intermediate gp120 structures formed as a result of coreceptor interactions. Such findings have important implications for HIV vaccine approaches based on conformational alterations in envelope structures.

Exponential Gain and Saturation of a Self-Amplified Spontaneous Emission Free-Electron Laser

Self-amplified spontaneous emission in a free-electron laser has been proposed for the generation of very high brightness coherent x-rays. This process involves passing a high-energy, high-charge, short-pulse, low-energy-spread, and low-emittance electron beam through the periodic magnetic field of a long series of high-quality undulator magnets. The radiation produced grows exponentially in intensity until it reaches a saturation point. We report on the demonstration of self-amplified spontaneous emission gain, exponential growth, and saturation at visible (530 nanometers) and ultraviolet (385 nanometers) wavelengths. Good agreement between theory and simulation indicates that scaling to much shorter wavelengths may be possible. These results confirm the physics behind the self-amplified spontaneous emission process and forward the development of an operational x-ray free-electron laser.

Observation of self-amplified spontaneous emission and exponential growth at 530 nm

Experimental evidence for self-amplified spontaneous emission (SASE) at 530 nm is reported. The measurements were made at the low-energy undulator test line facility at the Advanced Photon Source, Argonne National Laboratory. The experimental setup and details of the experimental results are presented, as well as preliminary analysis. This experiment extends to shorter wavelengths the operational knowledge of a linac-based SASE free-electron laser and explicitly shows the predicted exponential growth in intensity of the optical pulse as a function of length along the undulator.

Effects of escape to alone versus escape to enriched environments on adaptive and aberrant behavior

Escape-maintained aberrant behavior may be influenced by two outcomes: (a) a break from the activity and (b) subsequent access to preferred activities. To assess this hypothesis, a treatment was developed that analyzed response allocation across two break options: break alone and break with access to preferred social activities. The break with preferred activities decreased aberrant behavior and increased appropriate behavior.

Possibility of improving the acceptance rateof early detection testing for prostate cancerwith a one-step test for prostate-specific antigen in whole blood

In order to increase the acceptance rate of early detection testing for prostate cancer, a qualitative prostate-specific antigen (PSA) one-step test has been developed. Determining the PSA level with this test system takes 10 min. The blood samples of 190 men were tested in this qualitative assay, which uses 50 microl of EDTA whole blood and in which the results are ascertained visually. Parallel samples were tested in serum-based, quantitative assays (Abbott Imx, EIA). The findings of the two kinds of assays were compared and evaluated regarding their correspondence (<4.0 and > or = 4.0 ng/ml). For the 74 blood samples in which the quantitative assay showed PSA levels <4.0 ng/ml, the PSA one-step test showed 83.8% correct negative results (corresponds to diagnostic specificity). For the 116 samples in which the classic assay showed PSA levels > or = 4.0 ng/ml, the one-step test showed 90.5% correct positive results (sensitivity). The noted deviations appear especially around the cut-off value of 4.0 ng/ml, i.e. within the PSA concentration range of 3.0 < 4.0 and 4.0 < 5.0 ng/ml. The qualitative PSA one-step test presented here demonstrates good reproducibility. It can be conducted by the patient and is easy to use. The test offers a simple, feasible method for early detection programs for prostate cancer.

Survival and prognostic stratification of 670 patients with advanced renal cell carcinoma

PURPOSE

To identify prognostic factors and a model predictive for survival in patients with metastatic renal-cell carcinoma (RCC).

PATIENTS AND METHODS

The relationship between pretreatment clinical features and survival was studied in 670 patients with advanced RCC treated in 24 Memorial Sloan-Kettering Cancer Center clinical trials between 1975 and 1996. Clinical features were first examined univariately. A stepwise modeling approach based on Cox proportional hazards regression was then used to form a multivariate model. The predictive performance of the model was internally validated through a two-step nonparametric bootstrapping process.

RESULTS

The median survival time was 10 months (95% confidence interval [CI], 9 to 11 months). Fifty-seven of 670 patients remain alive, and the median follow-up time for survivors was 33 months. Pretreatment features associated with a shorter survival in the multivariate analysis were low Karnofsky performance status (<80%), high serum lactate dehydrogenase (> 1.5 times upper limit of normal), low hemoglobin (< lower limit of normal), high "corrected" serum calcium (> 10 mg/dL), and absence of prior nephrectomy. These were used as risk factors to categorize patients into three different groups. The median time to death in the 25% of patients with zero risk factors (favorable-risk) was 20 months. Fifty-three percent of the patients had one or two risk factors (intermediate-risk), and the median survival time in this group was 10 months. Patients with three or more risk factors (poor-risk), who comprised 22% of the patients, had a median survival time of 4 months.

CONCLUSIONS

Five prognostic factors for predicting survival were identified and used to categorize patients with metastatic RCC into three risk groups, for which the median survival times were separated by 6 months or more. These risk categories can be used in clinical trial design and interpretation and in patient management. The low long-term survival rate emphasizes the priority of clinical investigation to identify more effective therapy.

[Criteria for clinical studies exemplified by immuno- and immunochemotherapy of renal cell carcinoma]

Clinical trials of phase I to III are the basis of testing drugs before their wide use among patients. In order to provide high quality treatment in oncology, particularly in palliative care of tumour patients, it is of critical importance to pay attention both to study characteristics and to the relevant German laws for clinical drug testing. For more than 20 years interleucin-2 and interferon-alpha based immunotherapy of metastatic renal cell carcinoma has been in controversy. In spite of various clinical protocols no consensus concerning the value of these concepts has been reached. Therefore, high quality oncological studies are necessary to determine the effectiveness of this type of immunotherapy and to avoid an uncritical application of a toxic and expensive treatment.

[Urinary calculi in small and other animals--a retrospective study of the years 1980-1989]

More than 500 uroliths from dogs, cats, minks, rabbits and 9 further animal species originating from various regions of former East Germany were analysed. The observations were made between 1980 and 1989 using X-ray diffraction and infrared spectroscopy. The urinary stones consisted of struvite, whewellite, weddellite, cystine, ammonium urate, brushite, whitlockite, hydroxyapatite or carbonate-apatite, calcium carbonate, silicon dioxide and organic matrix stones. In dogs, the most frequent types were struvite and apatite concrements, followed by calcium oxalate and cystine uroliths. Among the diseased animals poodles, dachshunds and terriers ranked first. In the analysed material from cats apatite and struvite predominated. With few exceptions, minks formed struvite uroliths only. The analysed calculi from rabbits consisted principally of calcium phosphate or calcium carbonate concrements. The present analysis has been compared with results of former studies, differences are discussed.

The direct determination of urinary oxalate by non-suppressed ion chromatography

In this paper we describe a simple ion chromatographic method for determination of oxalate in urine. Acidified urine was diluted 1:2 with 0.03 mol/l benzidine hydrochloride in 0.3 mol/l boric acid to precipitate sulphate. The supernatant was passed through a C18-cartridge and 100 microliters of eluant were injected into an ion chromatographic system. Oxalate was measured by nonsuppressed conductivity detection. The detection limit for urinary oxalate was 0.05 mmol/l. The recovery for spiked urine samples was 101.5% with a CV of 4.5%. The within- and between-assay coefficients of variation were less than 4.5% and 2.5%, respectively. We found the results obtained by this method to be statistically equivalent to an enzymatic assay and a different ion-chromatographic method.

The long-term effects of functional communication training in home settings

A four-phase study was conducted in the homes of 4 young children who displayed aberrant behavior. Phases 1 and 2 consisted of a series of descriptive and experimental analyses to identify the environmental antecedents and consequences that controlled aberrant behavior. Phases 3 and 4 evaluated the short- and long-term effects of treatment on aberrant behavior, target mands, and collateral (social and toy play) behaviors. The effects of treatment were monitored for up to 27 months to assess long-term suppression of aberrant behavior. The assessment results successfully identified environmental events that occasioned and maintained aberrant behavior for all children. The short-term treatment resulted in immediate decreases in aberrant behavior for 3 of 4 children. Long-term treatment was successful for all children and was correlated with substantial response generalization. These results are interpreted in relation to functional equivalence, pivotal responding, and response generalization.

Measurement of urinary oxalic acid: a comparison of five methods

OBJECTIVE

Five methods for oxalate analysis in urine are compared with respect to reliability, accuracy, and practicability.

RESULTS

Suppressed and unsuppressed ionchromatography, as well as the enzymatic Sigma-Kit, achieve low coefficients of variation for the within-batch imprecision (1.1-8.0%) and between-day imprecision (1.6-7.2%). The results of these methods are comparable and the mean recovery rate ranges between 99.7% and 100.9%. The enzymatic Boehringer-Kit gives higher CV (3.1-9.5%) and the results are lower than those obtained by the methods mentioned above; the recovery rate is sufficient (92.4%).

CONCLUSION

The handling of the chromatographic methods is very easy, whereas the enzymatic methods require more manual work. In relation to sample throughput, charges for the enzymatic methods are about twice as high as for the chromatographic methods. In respect to reliability and accuracy, the chromotropic acid method cannot be recommended (recovery rate 68%).

Preliminary results for positron emission mammography: real-time functional breast imaging in a conventional mammography gantry

In order to optimally integrate radiotracer breast imaging within the breast clinic, anatomy and pathology should be easily correlated with functional nuclear medicine breast images. As a first step in the development of a hybrid functional/anatomic breast imaging platform with biopsy capability, a conventional X-ray mammography gantry was modified to image the compressed breast with positron emitters. Phantom studies with the positron emission mammography (PEM) device showed that a 1-cc hot spot could be detected within 5 min. A preliminary clinical trial demonstrated in vivo visualization of primary breast cancer within 4 min. For sites where positron-emitting radionuclides are available, PEM promises to achieve low-cost directed functional examination of breast abnormalities, with the potential for achieving X-ray correlation and image-guided biopsy.

Two measures of preference during forced-choice assessments

A forced-choice preference assessment was conducted in which two dependent measures were used to select preferred stimuli: (a) approach responding and (b) latency to the first aberrant response. Stimuli identified as preferred based on both dependent measures were then evaluated during treatment. The results suggested that latency may be a useful measure in the selection of preferred stimuli during forced-choice assessments.

The value of parasternal mediastinoscopy in staging bronchial carcinoma

Computed tomography (CT) is the non-invasive staging procedure of choice for assessment of metastasis to mediastinal lymph nodes in patients with bronchial carcinoma. Cervical mediastinoscopy can provide histologic evidence of mediastinal spread to the peritracheal, tracheobronchial and subcarinal lymph nodes. Sub-aortic and para-aortic nodes cannot be sampled via this route. The present study was performed to assess the staging value of the parasternal mediastinoscopy as a separate entity. Cervical and parasternal mediastinoscopy was performed in 37 patients with a proven diagnosis of non-small cell carcinoma of the left upper lobe. In 16 patients lymph node or tumor tissue could be biopsied via the parasternal route, in 21 patients no parasternal biopsy was taken. Of the 16 cases with biopsies, only one was positive (6%). Histologic examination of lymph node biopsy tissue was false negative in one other patient (6%). Of the 21 patients without biopsies taken during parasternal mediastinoscopy, three (14%) had proven lymphogenic spread to the subaortic and para-aortic nodes, detected at thoracotomy. The parasternal procedure changed treatment in only one patient (3%). Diagnostic sensitivity was 20%. It is concluded that parasternal mediastinoscopy should not be used as a routine staging procedure in patients with left upper lobe lung cancer.