Non-parametric Kruskal-Wallis ANOVA Research Articles

Effectiveness in cleaning oval‐shaped root canals using Anatomic Endodontic Technology, ProFile and manual instrumentation: a scanning electron microscopic study

To compare in vitro the cleanliness of root canal walls in oval-shaped root canals following automated or manual instrumentation. Forty-five oval-shaped single-rooted maxillary and mandibular premolars with straight canals were divided into three groups of 15. Automated canal preparation was performed using Anatomic Endodontic Technology (AET, group 1) and the ProFile system (group 2). Manual instrumentation (group 3) was performed with K-Flexofiles. Irrigation was performed using alternately 5.25% NaOCl and 17% EDTA, followed by rinsing with saline. The roots were split longitudinally into halves and the canals examined at x200 and x400 in a scanning electron microscope. The presence of debris and smear layer was recorded at distances of 1, 5 and 10 mm from the working length using a three-step scoring scale and a 300 mum square grid. Mean scores for debris and smear layer were calculated and statistically analysed for significance (P < 0.05) between and within groups, using the Kruskal-Wallis nonparametric anova and Dunn's tests. At 1, 5 and 10-mm levels the root canals prepared with AET had significantly less surface debris and smear layer on the canal walls compared with canals prepared with ProFile or manual instrumentation. For all three groups significantly lower mean smear layer scores (P < 0.05) were recorded at 5 and 10-mm levels compared with the 1 mm level. Significantly lower mean debris scores (P < 0.05) were also recorded at 5 and 10-mm levels for the AET group whereas no significant differences were found between the three levels for the ProFile and manual instrumentation groups. Although better instrumentation scores were obtained in canals prepared with AET, complete cleanliness was not achieved by any of the techniques and instruments investigated.

Peritoneal fluid cytokines and sICAM-1 in minimal endometriosis: search for discriminating factors between infertility and/or endometriosis

Objective:To evaluate cytokine levels (IL-1β, TNF-α, IL-6, IL-8), soluble intercellular adhesion molecule-1 (sICAM-1) and number of macrophages in peritoneal fluid (PF) of women with no minimal endometriosis and associated (or not) infertility in order to discriminate between infertility and/or endometriosis. Study design:Cytokines and sICAM-1 were measured by using quantitative enzyme-linked immunosorbent assay (ELISA) while the macrophages were identified by May-Grunwald-Giemsa and non-specific esterase staining and presented as medians. The measurements were performed in 78 women belonging to four selected subgroups according to their endometriosis and/or infertility status. Statistical analysis was performed using Kruskal–Wallis non-parametric ANOVA test. Additionally, discriminant function analyses were performed. Results:We have found the most elevated macrophage numbers in the groups of women with endometriosis. IL-1β did not present any statistically significant values differentiating the analysed subgroups. IL-6 (110.0pg/ml) and TNF-α exhibited the highest concentrations (statistically significant) in a group of fertile women with endometriosis. IL-8 clearly differentiated between the subgroups with infertility and sICAM-1 was statistically significantly elevated in the subgroups of infertile women. In the forward discriminant analysis, when subdividing the studied population according to its infertility status (we considered macrophages, IL-8 and IL-6 in order of probability values), we have found striking probability value of 92% for the correct classification into an infertile population. Conclusion:Out of the range of the analysed factors we have found only the sICAM-1 to be singled out between the standard discriminant analysis and the forward one. However, this important flagging molecule might be of considerable value for discrimination between different types of pathology at the level of immune effector function. The increased levels of TNF-α and IL-6 signified a group of fertile women with endometriosis; however only IL-6 presented a discriminating value in multifunctional analysis of examined subgroups. The analysed range of factors had a greater tendency to discriminate between infertility status rather than endometriosis.

Oral arginine improves intestinal recovery following ischemia-reperfusion injury in rat

Arginine and nitric oxide are critical to the normal physiology of the gastrointestinal tract and maintain the mucosal integrity of the intestine in various intestinal disorders. In the present study, we evaluate the effects of oral arginine (ARG) supplementation on intestinal structural changes, enterocyte proliferation, and apoptosis following intestinal ischemia-reperfusion (IR) in the rat. Male Sprague-Dawley rats were divided into three experimental groups: sham rats underwent laparotomy and superior mesenteric artery mobilization, IR rats underwent superior mesenteric artery occlusion for 30 min following by 24 h of reperfusion, and IR-ARG rats were treated with enteral arginine given in drinking water (2%) 48 h before and following IR. Intestinal structural changes, enterocyte proliferation, and enterocyte apoptosis were determined 24 h following IR. A nonparametric Kruskal-Wallis ANOVA test was used for statistical analysis with p <0.05 considered statistically significant. IR rats demonstrated a significant decrease in bowel weight in duodenum and jejunum, mucosal weight in jejunum and ileum, and villus height in jejunum and ileum compared with control animals. IR rats also had a significantly lower cell proliferation index in jejunum and ileum and a higher apoptotic index in ileum compared with control rats. IR-ARG animals demonstrated greater duodenal and jejunal bowel weight; duodenal, jejunal, and ileal mucosal weight; and jejunal and ileal cell proliferation index compared with IR animals. In conclusion, oral ARG administration improves mucosal recovery following IR injury in the rat.

Effect of Gonadotropin-Releasing Hormone Analogs on Bcl-2 and Bax expression in endometrial cultures from patients with endometriosis

Effect of Gonadotropin-Releasing Hormone Analogs on Bcl-2 and Bax expression in endometrial cultures from patients with endometriosis

Evaluation of Ultrasonically Placed MTA and Fracture Resistance with Intracanal Composite Resin in a Model of Apexification

The purpose of this study was to evaluate whether intracoronal delivery of an apical barrier of mineral trioxide aggregate (MTA) placed ultrasonically, non-ultrasonically, or ultrasonically with the addition of an intracanal composite resin provided a better seal against bacterial leakage. A second purpose was to determine whether intracanal composite resin or gutta-percha and sealer placed against an apical barrier of MTA provided greater resistance to root fracture. In a standardized in vitro open apex model, MTA was placed as an apical barrier at a thickness of 4 mm, with and without ultrasonic vibration. The barriers were challenged with bacteria exposure within a leakage model, and fracture resistance was assessed with increasing forces applied via an Instron machine. After 45 days, the addition of ultrasonics significantly improved the MTA seal, compared with the non-ultrasonics treatment (Kruskal Wallis nonparametric ANOVA with Dunn multiple comparison test p < 0.05). Bacterial leakage occurred in 6 (33%) of 18 in the non-ultrasonic MTA group, 2 (11%) of 18 in the ultrasonic MTA group, and 1 (6%) of 18 in the ultrasonic MTA-composite group. There were no significant differences at 90 days. A 4-mm thickness of MTA followed with an intracanal composite resin demonstrated a significantly greater resistance to root fracture than MTA followed with gutta-percha and sealer (one-way ANOVA with Newman-Keuls multiple comparison test, p < 0.01). The MTA-gutta-percha group was not significantly different than the MTA unrestored positive control.

Influence of Cavity Configuration on Microleakage around Class V Restorations Bonded with Seven Self‐Etching Adhesives

The purpose of this study was to evaluate microleakage around Class V resin composite restorations with different cavity configurations, bonded with one of seven self-etching materials or with an adhesive using the total-etch technique. Ninety-six human molars and premolars were randomly assigned to eight groups and bonded with one of seven self-etching adhesives--Prompt-L-Pop (3M ESPE, St. Paul, MN, USA), Adper Prompt-L-Pop (3M ESPE), Clearfil SE Bond (Kuraray Medical, Okayama, Japan), Prime & Bond NT/NRC (Dentsply DeTrey, Konstanz, Germany), Xeno III (Dentsply DeTrey), One-Up Bond (Tokuyama Dental, Tokuyama, Japan), AdheSE (Ivoclar Vivadent, Schaan, Liechtenstein)-or with Prime & Bond NT (Dentsply DeTrey) using a separate total-etch technique. Cavities were cut in both the lingual and buccal surfaces and were approximately 3 mm mesiodistally, 1.5 mm deep, and 2.0 mm occlusogingivally. Selected at random, box-shaped cavities were cut on one side and V-shaped cavities were cut on the contralateral side. After bonding, the cavities were incrementally filled with a microhybrid composite (Tetric Ceram, Ivoclar Vivadent), cured, and immediately polished with Sof-Lex (3M ESPE) disks. The teeth were thermocycled, and the specimens were examined for microleakage using Procion Brilliant Red (ICI, Slough, UK) as a marker. Comparisons of both gingival and enamel margins within each of the groups showed no significant difference owing to configuration factor (C-factor; p > .5 in all cases, calculated with Kruskal-Wallis nonparametric analysis of variance [ANOVA]) and Dunn's multiple comparison test). All groups showed microleakage at the gingival margins irrespective of C-factor or bonding agent (box-shaped cavities, p = .8862; V-shaped cavities, p = .9623; using the ANOVA). Microleakage was not observed at all enamel margins regardless of C-factor or bonding agent, and there were no significant differences between the groups (box-shaped cavities, p = .9869; V-shaped cavities, p = .9550; using the Kruskal-Wallis nonparametric ANOVA).

Sleep polygraphy in Angelman syndrome.

Sleep disturbances are frequent in Angelman syndrome (AS); however, beside the few studies which have investigated sleep disorders in AS by means of questionnaires, to our knowledge, no systematic polysomnographic recordings have been carried out in AS patients. The present study represents the first attempt to study sleep patterns of AS by polysomnography, to evaluate the influences of sleep on the paroxysmal electroencephalogram (EEG) patterns of AS and to assess the eventual age-related changes of sleep architecture and of sleep EEG abnormalities in children and adolescents with AS. Fifteen children with AS (7 males and 8 females, mean age 7.2 years, range 3-16 years), attending the Sleep Center of the Department of Child Neurology and Psychiatry of the University of Rome 'La Sapienza' and the Sleep Research Centre of the Oasi Institute (IRCCS) of Troina were included and subdivided into two subgroups by age: subgroup 1, aged 3-5 years, and subgroup 2, aged 9-17 years. Two control groups of age-matched normal subjects were also included: one aged less than 8 years and another aged more than 8 years; additionally, two other groups of age-matched children with epilepsy and mental retardation of different origin, one aged less and one aged more than 9 years were taken into consideration. The statistical comparison between the sleep parameters obtained from the patients and those from the other groups was carried out by means of the non-parametric Kruskal-Wallis ANOVA and the Mann-Whitney U test. The most frequent EEG abnormality found in AS patients appeared to be the 2-3 c/s poorly defined spike/waves complexes. This pattern was influenced by sleep stages; the duration of the runs showed an increasing length with sleep deepening from sleep stage 1 to slow-wave sleep (SWS). Moreover, the 2-3 c/s bursts activity present in sleep stage 2 showed a slowing to 1-2 c/s during SWS. Regarding sleep architecture, in subjects with AS aged <8 year there was a significant reduction in sleep efficiency as compared to normal controls, while the percentage and duration of REM sleep was significantly lower and the percentage of SWS was significantly higher. REM sleep time was reduced in AS subjects aged >8 years than in normal controls. The comparison between AS groups and mental retardation with epilepsy groups did not show significant differences. Similarly to other types of genetically determined mental retardation syndromes, also subjects with AS seems to show important abnormalities of their sleep polysomnographic patterns. This is the first study which reports, in detail, these abnormalities and opens a new path for further insight into the knowledge of additional sleep-related disturbances which are reported in sleep questionnaires by the caregivers of AS subjects.

Statistical validation of a commonly used method for personnel dosimetry issuance determinations.

In 1992, the federal requirements for personnel monitoring of occupational radiation doses were modified, making monitoring compulsory only for individuals "likely" to exceed 10% of the applicable annual dose limits. This regulatory change served as a catalyst for many radiation protection programs to re-evaluate their personnel monitoring issuance criteria to determine if some monitoring services might be reduced or eliminated. But in the absence of any clear definition of the term "likely," radiation protection programs relied on adjustments largely based on reviews of previous monitoring results and professional judgment. Although such semi-quantitative assessments may have been appropriate, the approach was not without inherent programmatic risks, as radiation dosimetry programs have been shown to be a consistent source of regulatory non-compliance upon inspection and serve as essential elements in defense against litigation efforts purporting workplace-related radiation injury. The objective of this study was to subject this commonly used method for post-regulatory change dosimetry issuance determinations to statistical validation. Personnel monitoring data from The University of Texas Health Science Center at Houston Radiation Safety Program pre- and post-1992 regulatory changes were accessed and descriptively analyzed. The dynamic nature of the institutional environment made direct comparisons of individuals between years impractical, so 1990 mean dose levels for various independent variables were compared using the Kruskal-Wallis non-parametric ANOVA test at a significance level of alpha = 0.05. The data from 1998 were then analyzed to ascertain if the groupings identified as statistically different in 1990 were still being monitored. The analyses statistically validated the monitoring program reductions made by the University of Texas Health Science Center at Houston radiation protection program. In addition, statistical support for further monitoring program reductions were identified, if such reductions were deemed to be necessary in the future.

Clinical judgement and information seeking by nurses and physicians working with cancer patients.

This study examined and compared the processes of information collection and clinical judgement by nurses (n=107) and physicians (n=27) working with cancer patients. The data was collected in two university hospitals by means of a computer-simulated case description and the thinking-aloud method. Data interpretation was based on SPSS statistical software and the method of content analysis. Statistical differences between the two groups were tested with non-parametric Kruskal-Wallis Anova or the Mann-Whitney U-test. The Wilcoxon test was applied in pairwise comparisons. Independent questions were analysed by cross-tabulation and Pearson's chi(2). According to the results nurses and physicians apply different approaches to clinical judgement and problem-solving. On the basis of the status statement they received in the program both groups pointed to similar problems and sought a great deal of additional information. However the type of information required was different in the two groups. There were also significant differences in the knowledge base applied for purposes of clinical judgement: nurses tended to rely on personal knowledge, physicians on theory. Physicians were able to identify their patient's major clinical problems, but nurses had more difficulty doing this. On the other hand, nurses took a broader view on the general well-being of patients than physicians did.

Effect of gonadotropin-releasing hormone analogs on the apoptosis and release of IL-1 and VEGF in endometrial cultures from patients with endometriosis

Objective: To evaluate the effect of the treatment with GnRH analogs (agonist = ag and antagonist = ant) on the apoptosis and interleukin-1 (IL-1) and vascular endothelial growth factor (VEGF) release by cultures of epithelial cells from eutopic endometrial tissue of patients with endometriosis (EDT). Design: Prospective study. Materials/Methods: For cultures of epithelial endometrial cells (EEC), we have employed biopsies obtained in proliferative phase by laparoscopy from 16 untreated patients with EDT and 14 controls (without EDT). Purification and culture of EEC were done according to the technique described by Bongso et al. (Hum. Reprod. 1988;3:705–713). Cultures were treated with Leuprolide acetate (LA) 100 ng/ml as GnRHag, or Antide (A) 10 -7 M as GnRHant or both, LA+A. Percentages of apoptotic cells (ApC) were measured using the acridine orange - ethidium bromide technique and levels of IL-1 and VEGF in culture supernatants were measured using ELISA commercial kits. Comparisons among groups were performed by Kruskal-Wallis nonparametric ANOVA test, and Dunn’s multiple comparison test. Results: Treatment with LA enhanced values of ApC in cultures from EDT patients ( 23.9 +/− 8.0% to 41.7 +/− 9.6%, p <0.01) and from controls (18.2 +/− 6.3% to 42.5 +/− 14.7%, p <0.05). Simultaneously LA treated cultures showed significantly decreased levels of IL-1 and VEGF. Values of IL-1 obtained in EDT patients were 223.0 +/− 56.0 pg/ml in basal conditions vs 83.6 +/− 16.3 pg/ml in LA treated cultures, p <0.05, and values obtained in controls were 201.5 +/− 58.6 pg/ml vs. 98.1 +/− 54.8 pg/ml in basal and LA treated cultures respectively (p <0.03). VEGF levels were 283.64 +/− 83.9 pg/ml vs 134.4 +/− 37.3 pg/ml in basal and LA treated ECC cultures from EDT patients respectively (p <0.04), and in controls VEGF values were 201.5 +/− 58.6 pg/ml in basal conditions vs 96.1 +/− 54.8 pg/ml in LA treated cultures (p <0.03). Cultures of ECC from patients and controls treated with GnRHant did not show any significant differences compared to basal conditions. Also, the addition of A to cultures of ECC pre-treated with LA, reverted the increased apoptosis and the drop in IL-1 and VEGF levels. We found no difference in any of the parameters studied between cell cultures from EDT patients and controls. Conclusions: GnRHag has local effects, by enhancing the percentage of ApC and decreasing the release of pro-mitogenic cytokines as IL-1 and VEGF in endometrial cells. GnRHant alone did not produce any significant effect but reverted the changes caused by treatment with GnRHag. Supported by: Agencia de Promocion Cientifica y Tecnologica de la Republica Argentina.

TGF-beta1 in patients with renal cell carcinoma.

Up to now, clinical tumor-markers for renal cell carcinoma (RCC) have been lacking. Increased plasma levels of transforming growth factor-beta1 (TGF-beta1) were described as a tumor-marker and prognostic factor in RCC. The aim of this study was to test the clinical suitability of plasma TGF-beta1 as a tumor-marker for RCC. The concentrations of active and latent TGF-beta1 were determined in plasma of patients with localized (n = 39) and metastasised (n = 17) RCC. A newly developed, highly sensitive ELISA, which is specific for the isoform beta1, was used. Active TGF was directly measured in the EDTA plasma. To determine the amount of latent TGF-beta1, which is bound predominantly at beta2-macroglobulin, an optimized activation procedure was applied. Patients with localized RCC showed median concentrations of 16,700 ng/l (6,200-54,800 ng/l) for latent TGF-beta1. A total of 94 patients with various nonmalignant urological diseases were recruited as a control group. In comparison, this group had median concentrations of 19,900 ng/l (2,640-52,300 ng/l) for latent TGF-beta1. There was no significant difference (nonparametric Kruskal-Wallis ANOVA) between these groups. Patients with metastatic RCC showed median concentrations of 34,500 ng/l (6,800-48,960 ng/l) for latent TGF-beta1. In comparison to the localized RCC group, a statistically significant difference was found. Plasma levels after operative therapy (days 1, 5 and 10) and during follow-up without evidence of disease (2-6 months) showed no significant differences. Contrary to other study groups, our results suggest that TGF-beta1 is not a suitable tumor-marker for the diagnosis of localized RCC. In the face of higher TGF-beta1 plasma levels in metastatic disease, TGF-beta1 may be useful in the early detection of RCC recurrence or to control the success of immunochemotherapy.

Interactions between haemolymph chemistry and condition in the southern rock lobster, Jasus edwardsii

A haemolymph colour index is developed in an attempt to improve the resolution of serum protein data in the characterisation of temporal and spatial changes in the condition and growth of a wild population of Jasus edwardsii. The index can be used as an indicator of nutritional condition if combined with conventional moult staging techniques. Lobsters and haemolymph samples were collected from two high- and two low-growth sites over two fishing seasons. Haemolymph samples were analysed for serum protein and astaxanthin level and categorised according to colour, that is, "pigment stage" (PS). Moult stage data were collected and abdominal and hepatopancreatic tissue analysed for percent dry weight. Haemolymph colour changes from light blue-grey, through beige, to deep orange during the moult cycle. These changes were explained with reference to the major pigment, astaxanthin, which increased from 0.135 mg/l (±0.054, n=38) at PS 1 (early intermoult) to 2.670 mg/l (±0.599, n=12) at PS 4.5 (late premoult). There were significant increases in percent abdominal and hepatopancreatic dry tissue weight over the moult cycle (Kruskal–Wallis non-parametric ANOVA, P<0.05), especially during intermoult. Serum protein levels increased concomitantly and were significantly correlated with percent dry weight of both tissues (abdomen: r 2=0.78, n=871, P<0.001; hepatopancreas: r 2=0.64, n=864, P<0.001) There were also significant differences between sites in both PS-specific serum protein and percent dry tissue. Lobster condition differed significantly between sites, probably as a result of temperature-mediated effects on growth rate. The addition of haemolymph pigment to the serum protein index allows the differentiation of lobsters at the beginning, middle and end of intermoult.

Subcellular localization of bilirubin in rat brain after in vivo i.v. administration of [3H]bilirubin.

Bilirubin appears to be toxic in vitro to several cellular functions localized to different subcellular compartments. It would therefore be useful to know what concentrations of bilirubin might be found in cell organelles in vivo. Rats were anesthetized and allocated to one of three groups: control, hypercarbia, and hyperosmolality. Each rat received a 5-min bolus dose of bilirubin 50 mg/kg i.v. (containing approximately 200 microCi [(3)H]bilirubin). Rats were killed 10 or 30 min after the start of the bilirubin infusion. Each brain was homogenized, and subcellular fractions were isolated by high-speed gradient centrifugation in sucrose media. The gradients were separated into aliquots of 2 mL, and the protein content was determined in each aliquot. Radioactivity was determined by scintillation counting, and the content of bilirubin per milligram of protein was calculated. Statistical comparisons were performed with Kruskal-Wallis nonparametric ANOVA. There were highly significant differences in bilirubin content per milligram of protein among subcellular compartments in all groups and at both time points. In all groups there were relatively high concentrations of bilirubin in the myelin fraction, an interesting observation in light of the theory that membranes are the primary target of bilirubin toxicity. The very high concentration of bilirubin relative to protein in cytoplasm, ribosomes, and mitochondria in the hyperosmolar group are also notable in light of data from hyperbilirubinemic animals in which changes in electrophysiology or energy metabolism only appeared after hyperosmolar opening of the blood-brain barrier. The present data may be useful in planning in vitro studies of bilirubin toxicity in cell organelles.

The effect of decortication on spinal fusion: an in vivo study in guinea pigs

Objectives: Although spinal fusion is one of the most commonly used procedures in spinal surgery its properties are not fully known. The role of decortication is still not clear. In this animal model, we investigated the effect of decortication on spinal fusion. Methods: The study included 30 male guinea pigs (Cavia porcellus). Spine exposure was obtained through the right subperiosteal dissection between L2 and L6 in all animals, whereas the left sides were used as controls. The animals were assigned to three groups including decortication and autografting (group 1), decortication, instrumentation, and autografting (group 2), and instrumentation and autografting without decortication (group 3). All animals were sacrificed in the sixth postoperative week. The fusion mass was assessed by means of macroscopic evaluation, manual stress test, radiologic examination, and microscopic evaluation. Results: Based on segmentary evaluations, fusion was obtained in 80%, 95%, and 92.5% in groups 1, 2, and 3, respectively. The results were found statistically significant (Kruskal-Wallis nonparametric ANOVA test, p<0.001). Conclusion: The results show that decortication should be an essential step for spinal fusion if spinal instrumentation is not considered. However, in case of a stable instrumentation, decortication seems to exert no positive effect on the formation of spinal fusion.

Finnish nurses' attitudes to pain in children.

This study measured the attitudes of Finnish paediatric nurses to children in pain and the connection between nurses' attitudes, nurses' attributes and nurses' own view of their knowledge and ability to take care of children in pain. The measurements were based on a purpose-designed instrument consisting of a 41-item Likert-type questionnaire and demographic data. The convenience sample consisted of paediatric nurses at all five university hospitals in Finland (n = 303). The response rate was 87%. ANOVA and non-parametric Kruskal-Wallis ANOVA were used as statistical methods. The results show that, taken as a whole, the attitudes of these nurses do not hinder effective pain management but there are some misconceptions that need further attention. It also emerged that such attributes as nurses' age, education, experience, place of work and field of expertise do not have a significant effect on nurses' attitudes. Nurses working in operating theatres felt they had a limited scope to work together with parents and in some hospitals nurses felt they had limited scope to work together with other staff groups. The units differed significantly in nurses' views about the unit's possibilities to provide treatment for pain. The findings of this study indicate that although nurses' attitudes to pain management are mainly positive, there is much variation in how they feel they can actually provide quality care to control pain. More attention should be paid to training nurses and to providing knowledge about the treatment of pain in children. Future research should look at nurses' existing knowledge base as well as their activities in the assessment and management of pain.

Gastrin concentrations in plasma of cats with chronic renal failure

Objective— To determine the prevalence of hypergastrinemia in cats with naturally developing chronic renal failure (CRF) and the correlation between gastrin concentration in plasma and severity of CRF. Design— Cohort study. Animals— 30 cats with naturally developing CRF and 12 clinically normal control cats. Procedure— Gastrin concentrations in plasma were determined by double-antibody radioimmunoassay of blood samples obtained from cats after food was withheld 8 hours. Concentrations were compared, using a nonparametric Kruskal-Wallis ANOVA. Results— 18 cats with CRF had high gastrin concentrations (median, 45 pg/ml; range, &lt; 18 to &gt; 1,333 pg/ml), compared with those for control cats (&lt; 18 pg/ml). Prevalence of hypergastrinemia increased with severity of renal insufficiency. Three of 9 cats with mild CRF, 6 of 11 cats with moderate CRF, and 9 of 10 cats with severe CRF had high gastrin concentrations. Gastrin concentrations were significantly different between control cats and cats with CRF, regardless of disease severity. Clinical Implications— The potential role of high concentrations of gastrin on gastric hyperacidity, uremic gastritis, bleeding from the gastrointestinal tract, and associated clinical signs of hypergastrinemia (eg, anorexia and vomiting) may justify use of histamine2-receptor antagonists or proton pump inhibitors to suppress gastric acid secretion in cats with CRF that have these clinical signs. (J Am Vet Med Assoc 1998;213:826-828)

Activation of neutrophil respiratory burst by cytokines and chemoattractants. Regulatory role of extracellular matrix glycoproteins

We investigated the in vitro responsiveness of neutrophils adherent to fibronectin (FN) and laminin (LM), toward natural pro-inflammatory and/or phagocyte-activating agents. Neutrophils from normal volunteers were layered on polystyrene wells precoated or not with FN and/or LM and tested for their ability of responding to eleven pro-inflammatory mediators by evaluation of superoxide anion (O2-) production and adherence. Results, expressed as mean +/-1SEM, were evaluated by non-parametric analyses (Mann-Whitney U-test or Kruskal-Wallis non-parametric ANOVA analysis) Precoating polystyrene wells with LM or FN prevented the plastic-induced neutrophil (O2-) production. Among eleven agents, tumor necrosis factor-alpha (TNF, 3.0+/-0.3 nmoles (O2-)/5 x 10(4) neutrophils/180 min, p < 0.001), granulocyte-macrophage colony stimulating factor (GM-CSF, 2.1+/-0.3 nmoles (O2-)/5 x 10(4) neutrophils/180 min, p < 0.05) and formyl-peptides (fMLP, 2.5+/-0.5 nmoles (O2-)/5 x 10(4) neutrophils/180min, p < 0.01) caused massive (O2-) production by neutrophils adherent to FN. None of the mediators was capable of triggering (O2-) production by neutrophils adherent to LM. LM, mixed with FN to coat wells, caused a dose-dependent inhibition of the oxidative burst triggered by TNF (IC50 LM: 0.84+/-0.03 microg, mean+/-1 SEM), GM-CSF (IC50 LM: 0.36+/-0.16micro/g, mean+/-1SEM) and fMLP (IC50 LM: 0.54+/-0.008 microg, mean+/-1 SEM). To the contrary, fMLP (85.5+/-27.7%), TNF (163.1+/-67.5%), and GM-CSF (121.8+/-66.4%) caused a significant augmentation of neutrophil adherence to LM, suggesting that LM-mediated inhibition of neutrophil oxidative metabolism does not depend on the concomitant LM-induced inhibition of neutrophil adherence. Finally, neither solid-phase FN nor LM affected (O2-) production by neutrophils in response to immune complexes. Extracellular matrix glycoproteins dictate the response of neutrophils to soluble mediators but not to immune complexes. This appears to be a biologically meaningful mechanism to localise the risk of cellular reactions to mediators that are able to diffuse easily from tissue sites of generation and become widely distributed in body fluids during inflammatory diseases.

In Vivo Subcellular Distribution of Bilirubin (B) in Rat Brain during Hypercarbia (HC) and Hypersomolality (HO). • 1018

Background There is as yet no agreement on what the basic mechanism(s) for B toxicity is/are. In designing and evaluating in vitro studies of B toxicity on cell organelles, it would be helpful to know what concentrations of B might be found in cell organelles in vivo. Materials and methods Young adult Sprague-Dawley rats were allocated to one of three groups: control, HC (inhalation of 15% CO2 in air [pH 6.89±0.07, PCO2 14.49±5.83 kPa]), and HO (infusion of carbamide IV [serum osmolality 408±31 mosm/L]). Each was then given a 5-min bolus dose of B 50 mg/kg IV (with 200 μCi 3H-B). Rats were killed 10 or 30 min after the start of the B infusion (n=8 in the control group at 30 min, n=7 in all other groups and time points), and the brain vessels were flushed in situ with ice cold saline. Each brain was then homogenized in 0.32 M sucrose in a glass-Teflon homogenizer and subcellular fractions were isolated by high-speed gradient centrifugation in sucrose media. Protein content was determined in all fractions/aliquots. The content of B per mg of protein was determined by scintillation counting. Statistical comparisons were performed with Kruskal-Wallis non-parametric Anova and Dunn's multiple comparisons test. Results There were highly significant differences between the B content of subcellular compartments (p<0.0001 for all groups at both time points). Mean values ranged from 10-813 pmol B per mg protein. In all groups there were relatively high concentrations of B in the myelin fraction. Concentrations were higher overall in the HO than in the two other groups, and particularly high in the HO cytoplasm fraction. Discussion The finding of high B concentrations in the myelin fractions is interesting in light of theories and data suggesting that membranes are an important target for B toxicity. The generally very high concentration of B relative to protein in the HO group is also notable in light of data from some studies of hyperbilirubinemic animals where changes in electrophysiology or energy metabolism only appeared after HO opening of the blood-brain barrier. Finally, data from whole brain have shown that HC is associated with rapid entry of B into brain in high concentrations, whereas the present data suggest that HO causes the highest concentrations of B in the subcellular compartments of brain cells.

APPLICATION OF SEDIMENTARY FECAL STANOLS AND STEROLS IN TRACING SEWAGE POLLUTION IN COASTAL WATERS

A coastal water disposal site for municipal wastewater sludge was established in the southeastern waters of Hong Kong in 1991. Although the assimilating capacity of such a disposal site was expected to be high, some accumulation of dumped sewage sludge on the nearby bottom sediments was considered inevitable. In this study, sedimentary fecal stanols and sterols, such as coprostanol (5β( H)-cholestan-3β-ol), cholestanol (5α( H)-cholestan-3β-ol) and cholesterol, were chosen as molecular markers for the tracing of deposited sewage contaminants in the vicinity of the disposal site. Sediment samples from eleven locations ranging from the centre of the disposal site to up to 20 km from the site were sampled in 1994. All sediment samples were shown to contain the molecular markers, with concentration ranges as follows (in μg/g of dry sediment): coprostanol 0.34–5.09; cholestanol 0.65–3.87; cholesterol 0.64–3.92. The fecal stanol/sterol ratio 5β/(5α + cholesterol) was found to be a suitable parameter for the comparison of sewage contamination in sediments. Non-parametric Kruskal-Wallis ANOVA and Student-Newman-Keuls pairwise multiple comparison analyses revealed that stations in the northeast and southwest of the disposal site were more polluted. Such anisotropic distribution of sewage markers was consistent with the directions of currents flowing through the disposal site. A mass balance model was developed to provide rough estimation of the sewage sludge loading in the sediments from the observed stanol/sterol ratio. © 1998 Elsevier Science Ltd. All rights reserved

Using randomization techniques to analyse behavioural data

Data from behavioural studies are frequently non-normally distributed and cannot be analysed with traditional parametric statistics. Instead, behaviourists must rely on rank-transformation tests, which lose potentially valuable information present in the data. Recently, however, biologists in other disciplines have resolved similar statistical difficulties by using resampling methods. Results from Kruskal–Wallis non-parametric ANOVA and randomization tests were compared for two behavioural data sets. It was found that randomization tests were more powerful than Kruskal–Wallis, and could thus detect smaller effect sizes present in the data. In addition, the variance was calculated around the P-value at eight levels of replication ranging from 500 to 10 000, to determine the optimal number of replications for the randomization test. The variance around the P-value decreased as the number of replications increased. The P-value stabilized at 5000 replications, and thus it is recommended that at least 5000 replications be used for randomization tests on behavioural data.