Spearman Rank-order Correlation Test Research Articles

Biopsy harvesting site and distance from the explant affect conjunctival epithelial phenotype ex vivo

The purpose of the study was to investigate if the number of goblet cells expanded ex vivo from a conjunctival explant is affected by the biopsy harvesting site on the conjunctiva and the distance from the explant. Conjunctival explants from six regions: superior and inferior bulbus, fornix, and tarsus of male Sprague–Dawley rats were grown in RPMI 1640 with 10% fetal bovine serum on coverslips for eight days. Histochemical and immunofluorescent staining of goblet (CK-7/UEA-1/MUC5AC), stratified squamous, non-goblet (CK-4), proliferating (PCNA) and progenitor (ABCG2) cells were analyzed by epifluorescence and laser confocal microscopy. Outgrowth was measured with NIH ImageJ. For statistical analysis the Mann–Whitney test and Spearman's rank–order correlation test were used. Cultures from superior and inferior fornix contained the most goblet cells as indicated by the presence of CK-7+, UEA-1+ and MUC5AC+ cells. Superior and inferior forniceal cultures displayed 60.8% ± 9.2% and 64.7% ± 6.7% CK-7+ cells, respectively, compared to the superior tarsal (26.6% ± 8.4%; P < 0.05), superior bulbar (31.0% ± 4.0%; P < 0.05), inferior bulbar (38.5% ± 9.3%; P < 0.05) and inferior tarsal cultures (27.7% ± 8.3%; P < 0.05). While 28.4% ± 6.3% of CK-7+ goblet cells co-labeled with PCNA, only 7.4% ± 1.6% of UEA-1+ goblet cells did (P < 0.01). CK-7+ goblet cells were located at a lower concentration close to the explant (39.8% ± 3.1%) compared to near the leading edge (58.2% ± 4.5%; P < 0.05). Both markers for goblet cell secretory product (UEA-1 and MUC5AC), however, displayed the opposite pattern with a higher percentage of positive cells close to the explant than near the leading edge (P < 0.05). The percentage of CK-4+ cells was higher near the explant compared to near the leading edge (P < 0.01). The percentage of CK-7+ goblet cells in the cultures did not correlate with the outgrowth size (rs = −0.086; P = 0.435). The percentage of UEA-1+ goblet cells correlated negatively with outgrowth size (rs = −0.347; P < 0.01), whereas the percentage of CK-4+ cells correlated positively with the outgrowth size (rs = 0.473; P < 0.05). We conclude that forniceal explants yield the highest number of goblet cells ex vivo and thereby seem to be optimal for goblet cell transplantation. We also suggest that CK-7+/UEA-1− cells represent highly proliferative immature goblet cells. These cells could be important during conjunctival migration as they are mostly located close to the leading edge and their density does not decrease with increasing outgrowth size.

Effect of Biopsy Location and Size on Proliferative Capacity of Ex Vivo Expanded Conjunctival Tissue

To evaluate the effect of location and size of biopsy on phenotype and proliferative capacity of cultured rat conjunctival epithelial cells. Pieces of conjunctiva were used from six areas: superior and inferior areas of bulbus, fornix, and tarsus of male Sprague-Dawley rats (n = 6). Explants were grown in RPMI 1640 with 10% fetal bovine serum on coverslips for 8 days or assayed for colony-forming efficiency (n = 9). Analysis included immunofluorescence microscopy and outgrowth measurements with ImageJ software. The Mann-Whitney test and Spearman's rank-order correlation test were used. Superior (23.9 ± 2.9-fold growth) and inferior (22.4 ± 1.2-fold growth) forniceal tissues yielded significantly more outgrowth with respect to explant size than superior bulbar (13.4 ± 1.9-fold growth; P < 0.05 and P < 0.01, respectively), inferior bulbar (13.6 ± 1.6-fold growth; P = 0.01 and P < 0.01, respectively), and inferior tarsal tissues (14.0 ± 1.3-fold growth; P = 0.01). Outgrowth size correlated positively with explant size (r(s) = 0.54; P < 0.001), whereas explant size correlated negatively with fold growth (r(s) = 0.36; P < 0.001). Superior forniceal cells displayed higher colony-forming efficiency (3.6% ± 0.9%) than superior bulbar (1.1% ± 0.3%; P < 0.05) and inferior bulbar cells (1.6% ± 0.8%; P < 0.05). Percentage of p63+ and PCNA+ cells correlated positively with explant and outgrowth size. Small forniceal conjunctival explants grow the most effectively; however, for transplantation purposes, the loss of p63+ and PCNA+ cells with small explants must be considered.

Assessed facial normality after Twin Block therapy

The first aim of this study was to identify any difference in the perception of facial normality between orthodontists and lay people of patients with the initial presentation of a Class II division 1 malocclusion, the second is to investigate whether there was an identifiable facial change following Twin Block (TB) therapy, and lastly, the relationship between identifiable facial change and clinical measurements was explored. Animated laser scans of 16 randomly selected adolescent patients, nine males aged 12-14 years and seven females aged 11-13 years with Class II division 1 malocclusions before and after TB therapy, were assessed on a visual analogue scale (VAS) by 34 orthodontists and 35 lay people. The 'Mark and Measure' and 'Orientated' techniques were used to determine soft tissue dimensions. Overjet was also recorded. Non-parametric statistical analyses were employed, including Mann-Whitney, Wilcoxon signed value, and Spearman's rank-order correlation tests. There was no statistically significant difference in facial normality scores of adolescents before TB therapy when assessed by orthodontists (46.2 mm) and lay people (50.9 mm; P = 0.120). However, TB therapy significantly improved the assessment score of the orthodontists (54.8 mm) and lay people (57.8 mm; P = 0.000). Using a 5 per cent threshold in categorization of change in VAS scores, the majority of assessors perceived an overall 'improvement' (87.0 per cent). An increase in soft tissue lower face height (ST LFH) and overjet reduction was strongly correlated with the higher assessments of lay people (r = 0.515) and orthodontists (r = -0.505), respectively. Although orthodontists and lay people assess facial normality of patients with Class II division 1 malocclusions similarly, following TB therapy an increase in ST LFH with lay people and overjet reduction with orthodontists were most closely related to improved facial normality.

Seasonality of nuclear abnormalities in gilthead sea bream Sparus aurata (L.) erythrocytes

The frequencies of erythrocyte nuclear abnormalities, such as irregularly shaped (ISN), vacuolated nuclei (VN), binucleated cells (BN), including micronuclei (MN), were monitored in the peripheral blood of cultured gilthead sea bream (Sparus aurata L.) from the southern Adriatic Sea (Croatia) and assessed for a relation to seasonality. Fish were sampled in February, April, June, and September. The lowest frequencies of ISN and MN were measured in April, and the lowest frequencies of VN and BN were found in February. The highest values of ISN and BN were detected in September. The highest values of MN and the most frequent occurrence of VN occurred in June and April, respectively. The Spearman rank order correlation test revealed a significant positive correlation between the frequencies of ISN, BN and MN; VN did not correlate with any of the measured parameters. The ISN had significantly higher nuclear surface area values than normal nuclei (P < 0.001). Our results demonstrate that the measured parameters displayed a distinct seasonality. Consequently, we conclude that seasonal variations should be taken into account when nuclear abnormalities are used as biomarkers. This variation should be well understood in order to successfully separate true contamination effects from seasonal factors that have the potential to affect the frequency and occurrence of nuclear abnormalities.

Welfare in a shelter dog rehomed with Alzheimer patients

Abstract This study evaluates whether a shelter dog could be rehomed successfully into a facility for people suffering from Alzheimer's disease (AD). The goal was to assess the effect on animal welfare of this form of pet ownership and of individual sessions of animal assisted activity (AAA) with some pre-selected patients. After the enrollment of a suitable shelter dog, the dog was introduced gradually into the facility. Upon adoption, the dog's welfare was monitored during the first 6 months by integrating indirect assessment (18-item questionnaire) with direct observations of behavioral and clinical responses (31-item score system table), and with an assay of hormonal changes. Only descriptive statistics were done on the questionnaire data. The findings suggest a progressive positive integration into the new environment. The qualitative data using direct observations were analyzed with the Spearman Rank order correlation test. Some data showed significant variation during the period of observation, suggesting a gradual reduction of the dog's stress during AAA sessions. The hormonal trend, especially for cortisol measured in hair, seemed to correlate with the clinical and behavioral findings.

Down‐regulated lymphocyte NF‐kB activation in breast cancer survivors following yoga participation

The purpose of the study was to examine lymphocyte NF-κB activation in female breast cancer survivors who participated in eight weeks of yoga. Survivors (Stages I-IV, age 61+7.4 yr, mean+SD) were randomly assigned to yoga (Y, n = 10) or waitlisted (WL, n = 9) groups. Iyengar yoga practice included two 90-minute classes per week plus one home practice. Demands of Illness (DOI) and lymphocyte NF-κB activation were evaluated pre- (T1) and post-yoga (T2). Lymphocyte NF-κB activation (Y, n = 5; WL, n = 4) was determined by EMSA following stimulation by phorbol 12-myristate 13-acetate, phytohemagglutinin and ionomycin. These data were initially analyzed by Mann-Whitney U test and Spearman Rank Order Correlation test. Results indicated that DOI significantly declined (p = 0.038) from T1 to T2 with yoga. The change in NF-κB activation from T1 (Y = 2563+1076, WL = 2029+1456, integrated density value/μg protein/106 cells) to T2 (Y = 1439+1142, WL = 2359+443) was significantly different (p = 0.039) between groups. Linear regression analysis of DOI and log transformed NF-κB activation data revealed a significant association between variables (r = 0.75, p = 0.01) in yoga participants only. These findings lend support to the hypothesis that yoga participation by breast cancer survivors can attenuate illness-related stressors and alter lymphocyte NF-κB regulation. Supported by Cancer Prevention and Research Center WSU; University of Washington Center for Women’s Health and Gender Research.

Structural characteristics of annual precipitation data in Jordan

Thirteen meteorological stations distributed across Jordan are selected in order to analyze the structure of annual precipitation data for the country. The length of data, for all stations, is 50 years, covering the common period 1953–2002. The analysis is based on a series of tests designed to determine if the annual total precipitation data taken from each station are consistent, random, and trend free. Consistency is defined simply using the classical doublemass curve, and a non-parametric test is used to determine randomness. The Fisher test is also employed to test for randomness of the series. In order to determine if the data are trend free, a simple linear trend model, as well as the Spearman Rank Order Correlation test, is used. Jump analysis is also performed following application of the segmentation procedure, and finally, the probability distribution fitted to the data set is determined using the Probability Plot Correlation Coefficient test. The study concludes with a description of the structural characteristics and temporal and spatial variation of annual precipitation data in Jordan, together with possible projections for the future.

Nuclear receptors in human immune cells: Expression and correlations

Nuclear receptors (NR) are key modulators of gene transcription. Their activity is ligand induced and modulates a large variety of tissue-specific cellular functions. However, for many NR little is known about their role in cells of the immune system. In this study, expression patterns and distribution of 24 NR were investigated in human peripheral blood mononuclear cells. We provide the first evidence of the expression of the 12 receptors CAR, CoupTFα, CoupTFβ, FXR, GCNF, HNF4α, PPARβ/δ, PXR, RevErbβ, TR2, TR4 and TLX in highly purified CD4, CD8, CD19, CD14 cells. The expression profile of RevErbα and LXRα previously observed in B cell and macrophages, respectively, has been extended to CD4, CD8 and CD14 cells. Except for RARβ, which was absence in any of the cells tested, our results suggest an almost ubiquitous expression of the NR in the different cell lineages of the immune system. The expression of CAR, CoupTFα, FXR was also confirmed at a protein level and despite conspicuous mRNA levels of HNF4α, only low levels of this receptor were detectable in the nuclear fraction of PBMCs. Expression of the latter receptors was mostly only a fraction (4–20%) of their expression in the thyroid gland, the adrenal gland, the lung or subcutaneous adipose tissue. The Spearman rank order correlation test was performed to examine the correlation in expression between individual nuclear receptor pairs in the four cell types for several donors. Distinct correlation patterns were observed between receptor pairs in the individual cell types. In CD4 T cells four NR, GCNF, PPARγ, PPARα7 and RevErbβ are perfectly correlated with each other ( P ≥ 0.0167). In the other cell types correlations between NR pairs were more diverse, but also statistically highly significant. Interestingly, the relative expression level of a number of receptor pairs ranked identical or similar in at least three (CoupTFα and PPARβ/δ, CoupTFβ and HNF4α as well as RORβ and PXR) or four cell types (CoupTFα and CoupTFβ, PPARγ and RevErbβ). Despite the variability of NR expression in immune cells, these results suggest that some of the NR may be co-regulated in human immune cells.

Urine Interleukin-8 as a Marker of Vesicoureteral Reflux in Infants

Vesicoureteral reflux (VUR) is a common finding in children presenting with urinary tract infection (UTI) and prenatally diagnosed urinary tract dilatation and in relatives of index patients. Children with VUR are at risk for ongoing renal damage with subsequent infections. Detecting VUR and renal scarring currently depends on imaging modalities with associated problems of radiation, invasiveness, and expense. Noninvasive methods would greatly facilitate diagnosis and would also help in identifying relatives of index cases who should be screened. Interleukin-8 (IL-8) is produced by epithelial cells of the renal tract in response to inflammatory stimuli and has been shown to increase during acute UTI. The objective of this study was to assess the urine levels of IL-8 as a noninvasive marker of VUR in infants in the absence of a recent UTI episode. We evaluated urine concentrations of IL-8 in 59 infants aged 1 month to 2 years. All infants were free of UTI for a minimum of 3 weeks before IL-8 evaluation. Infants were divided into 3 groups: group A, subjects with proven VUR (24 infants aged 0.15-1.95 years, median 0.43); group B, subjects with a history of UTI but negative investigation for VUR (14 infants aged 0.32-1.95 years, median 0.57); and group C, subjects without any history of acute or chronic condition that might impair renal function (21 infants aged 0.08-1.92 years, median 0.33). IL-8 concentrations were determined by a commercially available quantitative enzyme-linked immunosorbent assay. To avoid dilution effects, urinary levels of IL-8 were expressed as the ratio of cytokine-to-urinary creatinine. Results were presented as medians and ranges. The Kruskal-Wallis test, the Mann-Whitney rank sum U test, and the Spearman rank order correlation test were performed for the univariate analysis. Two-tailed P values were calculated and the conventional level of significance P < .05 was applied in all cases. Infants in groups A and B had been free of UTI for a period of 3 to 52 weeks (median, 5.0 weeks) and 3 to 78 weeks (median, 4.5 weeks), respectively, before IL-8 determination. No significant difference was noted in the length of the UTI-free period between groups A and B (P = .469). Urine creatinine concentrations did not differ among groups A, B, and C (medians 1.15, 2.25, and 1.15 micromol/mL, respectively; P = .080). The median urine IL-8/creatinine concentrations (pg/micromol) were 40.5 (range, 2.04-3874) in group A, 1.91 (range, 0.001-386) in group B, and 2.47 (range, 0.002-55.6) in group C. Urine IL-8/creatinine concentrations were significantly higher in group A than both in group B (P = .0003) and in group C (P < .0001). No significant difference was observed between groups B and C (P = .749). In group A, no significant correlation was shown between IL-8/creatinine concentrations and the presence of renal parenchymal damage (P = .506), reflux grade (P = .770), or time from UTI (P = .155). A receiver-operator characteristic curve was constructed by plotting the sensitivity versus the specificity for different cutoff concentrations of IL-8/creatinine. With a cutoff concentration of urinary IL-8/creatinine at 5 pg/micromol, the sensitivity of this marker in diagnosing VUR was 88%, the specificity 69%, the positive prognostic value 66%, and the negative prognostic value 89%. In higher cutoff concentrations, specificity of the marker increased but sensitivity rapidly decreased. We present evidence that urine IL-8 concentrations remain elevated in infants with VUR even in the absence of UTI and that a cutoff of 5 pg/micromol IL-8/creatinine is of high sensitivity and adequate specificity for diagnosing VUR. Elevated urine IL-8 levels in VUR and renal scarring have already been reported; however, the present study is, to our knowledge, the first to confirm significant differences between infants with VUR and infants with a history of UTI alone and healthy controls, and to suggest a reliable cutoff concentration for diagnosing VUR. Our findings additionally suggest that inflammatory process in VUR is ongoing even after UTI has resolved, pointing against the currently held belief that sterile reflux cannot harm kidneys. The chronic inflammatory cell infiltrate associated with reflux nephropathy rather than VUR itself might offer an explanation for the secretion of IL-8, which may well be independent of reflux grade. Using urine IL-8 for diagnosing VUR is not free of limitations, because IL-8 may be elevated as a result of urinary tract manipulation or undetected UTI. In addition, this study focused on infants and not in older children with longstanding VUR. Increased urine IL-8 concentrations after UTI has resolved is a promising noninvasive marker for an initial screening for VUR in infancy with high sensitivity and adequate specificity.

Intrahepatic Hepatitis B Virus Covalently Closed Circular DNA Can Be a Predictor of Sustained Response to Therapy

This study aimed to determine whether intrahepatic hepatitis B virus (HBV) covalently closed circular (ccc) DNA and total HBV DNA levels at the end of therapy would predict sustained response to therapy. Hepatitis B e antigen (HBeAg)-positive chronic hepatitis B patients receiving either lamivudine monotherapy or combination of peginterferon and lamivudine had liver biopsy at the end of 1 year therapy and were followed for 52 more weeks after cessation of therapy. Serum HBV DNA, intrahepatic HBV ccc DNA, and total HBV DNA levels were determined. Forty-seven patients, including 34 males and 13 females, were studied. Twenty-seven patients received combination therapy, and 20 patients received lamivudine monotherapy. Twenty-nine patients had end-of-treatment virologic response, and 15 patients had sustained response 52 weeks after therapy. At the end of treatment, log serum HBV DNA levels correlated well with log intrahepatic HBV cccDNA and log intrahepatic total HBV DNA levels. Log intrahepatic cccDNA and log intrahepatic total DNA levels were significantly lower among patients with sustained virologic response. The adjusted odds ratio for log cccDNA was 5.3 (95% CI: 1.5-18.2, P = .009) and, for log intrahepatic HBV DNA, was 4.4 (95% CI: 1.3-14.7, P = .015) to predict sustained virologic response. Using log cccDNA at -0.80 copies/genome equivalent as cutoff, the sensitivity, specificity, and positive and negative predictive values and accuracy of predicting sustained virologic response were 73%, 78%, 56%, 86%, and 77% respectively. Intrahepatic HBV cccDNA and intrahepatic total HBV DNA levels at the end of therapy are superior to serum HBV DNA as surrogates of sustained virologic response.

Comments on the paper "c-erbB-2 expression and nuclear pleomorphism in canine mammary tumors"

,Dutra et al. (1) evaluated the influence of c-erbB-2 expression and nuclear polymor-phism on survival using a semiquantitativescoring system. Survival was calculated us-ing the Spearman rank correlation test. Theyobtained a regression coefficient of r = 0.441for c-erbB-2 expression and of r = -0.295 fornuclear polymorphism, with P > 0.05 inboth cases. Therefore, the authors concludedthat neither c-erbB-2 nor nuclear polymor-phism could be considered to be prognosticfactors.We would like to discuss some of themethodological aspects of the study.1. In survival studies some individualswill still be alive at the end. Others may havebeen lost to follow-up some time earlier andthus survival times will be unknown for asubset of the study group. There is a consen-sus that these so-called “censored” casesmust be included in the analysis. Most sur-vival analyses use Kaplan-Meier plots, logrank tests or the Cox proportional hazardregression (2). A Spearman rank order cor-relation test, as carried out by Dutra et al.(1), can only be used if all the animals underobservation die (2).2. Both variables examined, c-erbB-2expression and nuclear pleomorphism, wereevaluated using a semiquantitative scoringsystem. Categorizing variables that are meas-ured on a continuum is a frequently usedprocedure in medicine, especially in surgicalpathology. By looking, for instance, at re-cently published issues of this Journal, wecan see considerable variation in the scoringsystems applied in histopathology, not onlybetween different groups but also within thesame laboratory (1,3-6).It is well known that categorization maybe useful for clinical decision-making, treat-ment recommendations, determining studyeligibility, or for illustration purposes (7),but we should be well aware that this proce-dure is dangerous for several reasons.When the probability of an event associ-ated with a quantitative prognostic factorvaries monotonously, the selection of a cut-off point is always arbitrary. This may createscientifically unrealistic models because thisprocedure discards potentially important in-formation since all values between the cut-off levels have an equal effect on the model.Therefore, categorization considerably low-ers the statistical test-power and can be seenas an introduction of measurement errors (8-14).This can be easily illustrated with a simpleexperiment. In Table 1 we simulated a pos-sible situation similar to that of the study ofDutra et al. (1): let us assume that 10 of 17dogs with neoplasia died. The percentages ofc-erbB-2-positive cells in the tumors had

The effect of maxillomandibular advancement on the pharyngeal airway and apnea-hypopnea index in obstructive sleep apnea syndrome patients

Problem: Maxillomandibular advancement (MMA) surgery has demonstrated good success for the treatment of obstructive sleep apnea syndrome (OSAS). MMA has been shown to increase the pharyngeal airway space postoperatively. This is thought to be one of the reasons for the decrease in apnea-hypopnea index (AHI) found during postoperative polysomnographic studies. The purpose of this study is to determine if there is a correlation between the increase in pharyngeal airway space and decrease in AHI. Methods: Charts were reviewed for OSAS patients who received MMA surgery between October 1996 and April 2002. The inclusion criteria were: 1) completion of a polysomnographic study before and a minimum of 6 months following surgery, 2) a standardized lateral cephalometric radiograph taken before and within 48 hours postoperatively, 3) a preoperative AHI greater than 10. The outline of the posterior pharyngeal wall, soft palate and base of tongue were traced preand postoperatively. The minimum perpendicular distance between the posterior pharyngeal wall and both the soft palate and base of tongue were measured. The airway measurements as well as the AHI were analyzed using the Wilcoxon signed rank test for significance between the pre and postoperative values. Changes in pharyngeal airway space and AHI were analyzed using the Spearman Rank Order Correlation Test. Results: A total of 48 patients received MMA surgery as treatment for OSAS during this time period with 20 satisfying the requirements (18 male and 2 female). The average age was 44 years (range of 34 to 61). Twelve patients had MMA, 7 patients had MMA in conjunction with genioplasty and 1 patient had maxillary advancement with a unilateral sagittal split osteotomy. The median increase in distance between the posterior pharyngeal wall and soft palate was 96% (maximum 325%, minimum 14%; first quartile 64%, third quartile 96%). The median increase in distance between the posterior pharyngeal wall and base of tongue was 108% (maximum 500%, minimum 0%; first quartile 73%, third quartile 157%). The median decrease in AHI was 78% (maximum 100%, minimum 23%; first quartile 52%, third quartile 98%). The Spearman Rank Order Correlation test was calculated and revealed no correlation between the increase in pharyngeal airway and decrease in AHI. Conclusions: Treatment of OSAS using MMA surgery resulted in an average decrease in AHI of 73% for this patient population. There was no correlation found between the increase in posterior pharyngeal airway space and the decrease in AHI postoperatively.

Increased Expression of a Novel Early Activation Surface Membrane Receptor in Cutaneous T Cell Lymphoma Cells

Increased Expression of a Novel Early Activation Surface Membrane Receptor in Cutaneous T Cell Lymphoma Cells

Quasar-Galaxy Correlations: A Detection of Magnification Bias

Weak gravitational lensing by clusters and superclusters can change our perception of the distribution of bright background quasars through the phenomenon of magnification bias. It has been suggested that this lensing will lead to an association of moderate-redshift quasars (z ~ 1.0–2.0) and foreground galaxies (z ~ 0.2–0.3). We report on the analysis of a sample of 90 CCD fields centered on moderate-redshift quasars that are bright at both radio (S5 GHz > 1 Jy) and optical (V < 21.0) wavelengths, along with 12 control fields. The quasars presented here are chosen to have the highest potential for evidence of this weak lensing effect. We find no evidence for the presence of rich galaxy clusters (Abell richness class 1) in the foreground of these fields. However, using a Spearman rank-order correlation test, we detect a correlation between galaxy number density and angular distance from bright quasars on scales of ~15' with a significance of 96%. The observed correlation is unlikely the result of Galactic dust and is consistent with weak gravitational lensing of the quasars by foreground matter. We also determine the two-point angular correlation function between these background quasars and foreground galaxies. We find a correlation amplitude of 0.056 ± 0.020 over scales of ~5'. This angular correlation is consistent with the semianalytic weak gravitational lensing models of Dolag & Bartelmann (published in 1997), which incorporate nonlinear evolution of mass clustering.

The significance of serum levels of insulin-like growth factor-1 in patients with prostate cancer.

To compare the serum levels of insulin-like growth factor-1 (IGF-1) in patients with prostate cancer and in control patients with no malignancy, and to evaluate any possible influence of testicular androgen withdrawal on the level of IGF-1 in patients with prostate cancer. IGF-1 was measured in serum samples from 238 patients using both a chemiluminescence method and a radio-immunoassay. From a subgroup of 19 patients presenting with newly diagnosed carcinoma of the prostate, IGF-1 and testosterone values were measured before and during the course of testicular androgen withdrawal, achieved by the administration of luteinizing hormone-releasing hormone (LHRH) analogues combined with anti-androgens. There were no significant differences in the mean serum levels of IGF-1 patients with and without prostate cancer (158.6 and 159.1 ng/mL, respectively). There were no significant differences in mean IGF-1 levels before and after antiandrogen therapy; the mean (median, SD, range) levels of testosterone (microg/L) and IGF-1 (ng/mL) before androgen withdrawal were 4.81 (4.84, 1.26, 3.11-6.93) and 157.1 (152.5, 26.7, 122.8-195. 1). After androgen withdrawal the corresponding values were 0.303 (0. 218, 0.24, 0.13-0.81) and 169.7 (31.7, 168.6, 124.9-227.6). A linear regression analysis (P = 0.76) and Spearman rank order correlation test (correlation coefficient -0.0613, P = 0.64) showed no association between levels of testosterone and IGF-1. Freeze and thaw cycles applied to the samples had no effect on the IGF-1 values measured. There was no significant association between IGF-1 serum levels and prostate cancer. Short-term androgen withdrawal using LHRH analogues combined with anti-androgens had no effect on the levels of IGF-1.

QUASAR-GALAXY CORRELATIONS: A SEARCH FOR AMPLIFICATION BIAS

Weak gravitational lensing by clusters and superclusters can change our perception of the distribution of bright background quasars through a phenomenon known as amplification bias. It has been suggested that this lensing will lead to an association of moderate redshift quasars (z ~ 1.0–2.0) and foreground galaxies (z ~ 0.2–0.3). We report on the analysis of a homogeneous sample of 32 CCD fields centered on quasars that are bright both at radio (S5 GHz > 1 Jy) and optical (V < 18.5) wavelengths, along with 11 control fields. These 69' × 69' fields are a small subset of our larger survey of the fields around approximately 100 quasars and approximately 20 control fields. The quasars presented here are chosen to have the highest potential for evidence of this weak lensing effect. We find no evidence for the presence of rich galaxy clusters (Abell richness class = 1) in the foreground of these fields. However, using a Spearman rank-order correlation test, we have detected a correlation between galaxy number density and angular distance from bright quasars on scales less than 30' with a significance of 99%. This angular correlation is consistent with the recent semianalytic models of Dolag & Bartelmann that incorporate nonlinear evolution of matter.

Relations between acetylcholine release and electrophysiological characteristics of theta rhythm: a microdialysis study in the urethane-anesthetized rat hippocampus.

In urethane-anesthetized rats, recording electrodes were implanted in the left dorsal hippocampus and a dialysis probe was placed in the contralateral dorsal or ventral hippocampus. Samples of extracellular acetylcholine (ACh) levels were assessed at 10-min intervals over a period of 30 min using microdialysis with high-performance liquid chromatography with electrochemical detection. EEG was recorded during the same period and amplitude, frequency, and duration of theta rhythm were calculated for each of the three 10-min intervals. Data were analyzed using the two-tailed Spearman rank-order correlation test. A positive and high rank correlation coefficient (rho = 0.90, p < 0.01, n = 8) was seen between the average ACh outflow in the dorsal hippocampus and the average theta amplitude, both being calculated for the entire collection period. A lower but statistically significant positive correlation (rho = 0.59, p < 0.01) between dorsal hippocampus ACh output and theta amplitude was also found when the couples of values collected for the 30-min period were pooled (n = 20). In contrast, frequency and duration of theta were not significantly correlated with dorsal hippocampus ACh release. Also, no statistically significant correlation (p > 0.05) was found between ACh output in the ventral hippocampus and theta parameters. Because changes in hippocampal ACh outflow are believed to be the reflection of changes in number and/or level of activity of cholinergic afferents to the dorsal hippocampus, our present findings support the view that, at least in the dorsal hippocampus of the urethane-anesthetized rat, the septohippocampal cholinergic projection regulates the theta amplitude but not frequency. Finally, the possibility that ACh outflow increase and tonic release in the hippocampus is not a sufficient condition to induce and maintain theta in the urethane-anesthetized rat is discussed.

Regionalized comparison of global Earth models of seismic velocity, geoid and topography: implications on the geodynamics of ridges and subductions

Global Earth models of seismic velocity anomalies and geoid heights have been compared using the non-parametric Spearman rank-order correlation test to analyse their spatial coherence at both global and regional scales. At the global scale, these comparison results are similar to previously published results. This confirms that the assumed linear relationship between the tomographic models and the geoid is valid at the global scale. The comparison between global Earth models was then conducted in two structural provinces — a ‘ridge’ province and a ‘subduction’ province. We observe a positive correlation between tomography and geoid data near the transition zone in the two provinces. A significant positive correlation between the geoid and the topography is observed in the ‘subduction’ province in the L = 7–8 and L = 9–10 wavebands. These positive correlations are consistent with the hypothesis of deep penetration of subducted slabs into the mantle. The correlation in these two wavebands also suggests that the mantle heterogeneities under subduction zones are characterized by wavelengths around 4000 km. In the ‘ridge’ province, the topography and the tomography are negatively correlated in the upper mantle at shorter wavelengths (up to L = 15). This result is in favour of a shallow origin of the ridge material.

A Shared Genetic Mechanism for Melanotic Encapsulation of CM–Sephadex Beads and a Malaria Parasite,Plasmodium cynomolgiB, in the Mosquito,Anopheles gambiae

APlasmodium-refractory strain ofAnopheles gambiaethat melanizes ookinetes and intrathoracically inoculated CM–Sephadex beads was mated to aPlasmodium-susceptible strain that does not melanize the parasite or the beads. The F1progeny were then backcrossed to the susceptible strain. Backcross progeny were given a blood meal containing infectivePlasmodium cynomolgiB, and the parasites were allowed to develop for 6–7 days, at which time the infected mosquitoes were injected with CM–Sephadex beads. The next day the mosquitoes were dissected and the beads were scored for degree of melanization while the parasites were scored for degree of encapsulation. A Spearman rank order correlation test of the degree of correlation between the bead melanization phenotype and the parasite encapsulation phenotype gave a correlation coefficient of 0.74 (P< 0.01). This strong correlation between the two melanization responses suggests that the mechanisms for differential bead and parasite melanization of these two mosquito strains share at least one major gene.

Evaluation of Somatostatin as a Plasma Tumor Marker in Medullary Thyroid Carcinoma

Somatostatin (SRIF) immunoreactivity has been frequently reported in tumor tissues of cell types, belonging to the APUD system, including medullary thyroid carcinoma (MTC). However, the value of SRIF as a plasma tumor marker for MTC is controversial. We have measured SRIF plasma levels in 35 patients with different stages of MTC to evaluate the use of SRIF as a plasma tumor marker compared to the current "gold standard" calcitonin (CT). The median SRIF value in healthy controls was 36.5 pg/mL, the upper limit of normal was defined at the controls. The median value was 28 pg/mL (p = 0.37, Mann-Whitney U test). Five patients in the control group and three in the MTC group had SRIF levels that exceed the 95th percentile. SRIF and CT levels correlated only weakly (0.38), as determined by the Spearman rank order correlation test. Pentagastrin stimulation led to a diagnostic increase in SRIF levels in only one of five MTC patients. During selective venous catheterization, diagnostic gradients for CT, allowing tumor localization, could be demonstrated, whereas measurement of SRIF levels did not aid in tumor detection. Although SRIF immunostaining may be valuable as an additional marker in the histochemical diagnosis of MTC, SRIF has no value as a plasma tumor marker in the diagnosis of this disease.