Interobserver variability in determining MIB-1 labeling indices in oligodendrogliomas

Several studies have shown that MIB-1 labeling indices correlate well with tumor grade and prognosis in a variety of tumor types. Several factors are responsible for some degree of variability in the determination of labeling indices. Interobserver variability is one of the factors often cited as responsible for this variability. A slide from each of 30 oligodendrogliomas, stained with MIB-1 antibody, was distributed to six pathologists. The same set of slides was reviewed by each individual. Each pathologist was instructed to determine a MIB-1 labeling index by evaluating 1,000 tumor cell nuclei from the area of the slide with the most staining. The labeling index record reflected a percentage of positive-staining tumor cells. Interobserver agreement was compared. MIB-1 labeling indices ranged from 0 to 45.7. Overall agreement was good (> or =0.75) with a concordance coefficient of 0.832 (confidence interval, 0.700 to 0.909). Variability was greater among tumors with higher labeling indices as compared with tumors with labeling indices closer to 0. The overall agreement of MIB-1 labeling indices, while not perfect, was good. The generally minor variability among observers may be related to differences in the area of the slide evaluated and in differing lower thresholds for interpreting positivity. Further improvement of concordance may theoretically be attainable by further training and discussion among observers.     

Nuclear organization of centromeric domains is not perturbed by inhibition of histone deacetylases

It is well established that modification of lysines in histone molecules correlates with gene expression and chromatin structure. It is not known whether this operates entirely at a local level, e.g. through the recruitment of specific proteins, or whether histone modifications might impact on more long-range aspects of chromatin organization. There is a distinctive organization of chromatin within the nucleus and the chromatin at the nuclear periphery of mammalian cells appears to be hypoacetylated. Previously it had been suggested that inhibition of histone deacetylases by TSA causes a gross remodeling of nuclear structure, specifically the recruitment of centromeric heterochromatin to the nuclear periphery. Here, we have quantified the nuclear organization of histone modifications and the localization of centromeric domains in human cells before and after TSA treatment. TSA alters the nuclear distribution of histone acetylation, but not that of histone methylation. TSA elevates levels of histone acetylation at the nuclear periphery but we see no alteration in the position of centromeric domains in the nuclei of treated cells. We conclude that the distinctive nuclear localization of centromeric domains is independent of histone acetylation.     

Changing contexts? The effects of a primary prevention program on classroom levels of peer relational and physical victimization

Whereas school‐based prevention programs often target deficits in individual children's social skills in order to limit their aggression or exposure to peer victimization, there is increasing evidence that school‐wide and classroom‐level factors can also affect the success of these programs. This short‐term longitudinal study involved 432 elementary school students from 44 classrooms in 17 urban schools. We investigated whether classroom characteristics (average levels of social competence, emotional problems, and behavioral problems) and school‐wide characteristics (proportion of children on income assistance and implementation of a peer victimization prevention program—the Walk away, Ignore, Talk, and Seek help [W.I.T.S.] program) experienced in Grade 1 influences changes in children's reports of relational and physical victimization at the end of Grade 2. Findings showed that classroom levels of emotional problems predicted increases in relational victimization (beyond individual differences in emotional and behavioral problems). Classroom levels of behavioral problems predicted reports of increases in physical victimization (beyond individual differences). Classroom levels of social competence also interacted with individual levels of emotional problems such that children with higher levels of emotional problems in classes with more socially competent children reported more relational and physical victimization. Higher school levels of poverty and lack of program involvement also predicted higher levels of physical victimization, beyond individual and classroom effects. The capacity of the W.I.T.S. program to influence classroom level characteristics and the moderating effects of school poverty on victimization were also assessed. © 2003 Wiley Periodicals, Inc. J Comm Psychol 31: 397–418, 2003.     

Genetics of the low density lipoprotein receptor:

Fibroblast association (plasma membrane binding plus intracellular accumulation) and degradation of radioiodinated low density lipoprotein (125I-LDL) index plasma membrane LDL receptor activity. Cultured fibroblasts from 23 subjects affected with familial hypercholesterolemia (HC) and from 95 subjects without HC (non-HCs) were tested for 125I-LDL association and degradation. Both LDL receptor activity indices were twice as high in non-HC and HC heterozygous cell strains. This is compatible with a major gene effect on LDL receptor activity. However, a considerable overlap between non-HC and HC heterozygous values was found in the 125I-LDL association assay [median (range) 970 (330-2500), and 450 (250-490), respectively] and in the degradation assay [median (range) 810 (280-2020), and 470 (160-790), respectively]. The values are expressed as ng 125I-LDL X mg cell protein-1 X 4.5 h-1. These great overlaps in the LDL receptor activity indices support the view that the influence of LDL receptor activity on the HC phenotype may be smaller than believed previously. Furthermore, for the diagnosis of HC, these LDL receptor activity assays are far more expensive and have less sensitivity and specificity than simple serum cholesterol determination. The LDL receptor-dependent 125I-LDL association values for the HC heterozygous individuals clustered into four groups. Family data supported the hypothesis that this variation could be due to four different LDL receptor variants, each coded for by different alleles at the LDL receptor locus. If confirmed, this finding may have implications for the understanding of the variable expression of HC and also of the genetic impact on lipoprotein metabolism and susceptibility to atherosclerosis in non-HCs.     

Performance status and comorbidity predict transplant-related mortality after allogeneic hematopoietic cell transplantation.

Comorbidity measurements have recently been used to improve estimation of tolerance to allogeneic hematopoietic cell transplantation (HCT). We sought to determine the independent effect of comorbidity and performance status on HCT outcome and to devise a simple risk classification system for transplant-related mortality. We analyzed 105 consecutively enrolled patients who underwent HCT and received reduced intensity conditioning with fludarabine, melphalan, and alemtuzumab. Comorbid conditions were tabulated using 2 scales, the Charlson Comorbidity Index (CCI) and the Kaplan-Feinstein Scale (KFS). Comorbid conditions were found in 47% of patients by the KFS and in 27% by the CCI (P < .001). Using the Eastern Cooperative Oncology Group Performance Status (PS) scale, 34% had a PS score >0 (range, 0-2). A simple scale combining the KFS and PS enabled separation of high- from low-risk patients, with 6-month cumulative incidences 50% and 15%, respectively for transplant-related mortality (P = .001) and enhanced prognostic power over the CCI alone (P = .018). Prospective studies evaluating more comprehensive functional and comorbidity measurements are warranted.     

NADPH oxidase inhibition improves neurological outcomes in surgically-induced brain injury

Neurosurgical procedures can result in brain injury by various means including direct trauma, hemorrhage, retractor stretch, and electrocautery. This surgically-induced brain injury (SBI) can cause post-operative complications such as brain edema. By creating a mouse model of SBI, we tested whether NADPH oxidase, an important reactive oxygen species producing enzyme, is involved in SBI using transgenic mice lacking gp91^phox subunit of NADPH oxidase (gp91^phox KO) and apocynin, a specific inhibitor of NADPH oxidase. Neurological function and brain edema were evaluated at 24 h post-SBI in gp91^phox KO and wild-type littermates grouped into SBI and sham-surgery groups. Alternatively, mice were grouped into vehicle- and apocynin-treated (5 mg/kg, i.p. 30 min before SBI) groups. Oxidative stress indicated by lipid peroxidation (LPO) was measured at 3 and 24 h post-SBI. The gp91^phox KO mice, but not the apocynin-treated mice showed significantly improved neurological scores. Brain edema was observed in both gp91^phox KO and wild-type groups after SBI; however, there was no significant difference between these two groups. Brain edema was also not affected by apocynin-pretreatment. LPO levels were significantly higher in SBI group in both gp91^phox KO and wild-type groups as compared to sham group. A trend, although without statistical significance, was noted towards attenuation of LPO in the gp91^phox KO animals as compared to wild-type group. LPO levels were significantly attenuated at 3 h post-SBI by apocynin-pretreatment but not at 24 h post-SBI. These results suggest that chronic and acute inhibition of NADPH oxidase activity does not reduce brain edema after SBI. Long-term inhibition of NADPH oxidase, however improves neurological functions after SBI.     

Hope, Coping, and Adjustment Among Children with Sickle Cell Disease: Tests of Mediator and Moderator Models

Tested mediator and moderator models of hope, coping, and adjustmentin 39 children with sickle cell disease. In home interviewsparents provided information on demographics and functionaladjustment. Children self-reported levels of hope, coping strategies,and psychological adjustment. Coping strategies moderated, butdid not mediate, the relationship between hope and adjustment.Hope was negatively associated with anxiety when active coping,support coping, and distraction coping was high. Avoidance copingdid not moderate the hope-adjustment relationship but was positivelyrelated to anxiety. No effects were found for depressive symptomsor for the functional measures of adjustment.     

The baroreceptor reflex and the cardiovascular changes associated with sustained muscular contraction in the cat

Summary In decerebrate unanaesthetised cats the cardiovascular effects of raising the pressure in a blind sac preparation of a carotid sinus on one side were examined at rest and during sustained contractions of hind-limb muscles. During a tetanic contraction the absolute value of the blood pressure and heart-rate components of the baroreceptor reflex response were not significantly changed from those at rest. The curve relating heart-rate and mean blood pressure, during carotid sinus distension, was similar at rest and when the muscles of the hind-limb were contracting tetanically, although each value of heart-rate was greater, suggesting a resetting of the baroreceptor reflex. By contrast, in the same experiments, suppression of the baroreceptor reflex changes in heart-rate and blood pressure could be demonstrated during the increases of blood pressure and heart-rate elicited by electrical stimulation of limb nerve. It was concluded that the increases in blood pressure and heart-rate elicited by the afferent discharge from muscles during sustained contraction are buffered to some extent by the baroreceptors, though their inhibitory effect is incomplete under these conditions.     

Preliminary reliability and validity of the Clinician-Administered PTSD Scale for schizophrenia

This study provides preliminary psychometric support for a version of the Clinician-Administered Posttraumatic Stress Disorder (PTSD) Scale (CAPS; D. D. Blake et al., 1990) adapted for use with patients with schizophrenia (CAPS-S; J. S. Gearon. S. Thomas-Lohrman, & A. S. Bellack, 2001). Nineteen women with schizophrenia and co-occurring illicit drug use disorders were administered the CAPS-S, the Structured Clinical Interview for DSM-IV diagnoses (SCID). and scales measuring trauma-related psychopathology. The results indicate that the CAPS-S can distinguish between those with and without PTSD and that the symptom clusters measure unified constructs. Interrater and test-retest reliability were high for PTSD diagnosis and symptom clusters. Solid convergent validity was demonstrated between the CAPS-S and SCID-based PTSD diagnoses and the Impact of Event Scale. There is also preliminary evidence of discriminant validity. These results support the use of the CAPS-S in women with schizophrenia.