Clinical, histopathological, cytogenetic and prognostic differences between mucinous and nonmucinous colorectal adenocarcinomas

OBJECTIVE: To assess the clinical and biological significance of histological typing of colorectal carcinomas. PATIENTS AND METHODS: The retrospective analysis of 142 consecutive patients who underwent surgical resection of a mucinous (MC; n = 27; 19%) or a nonmucinous (nMC; n = 115; 81%) colorectal adenocarcinoma was carried out. The two groups were compared in terms of the clinical features, p53 gene expression (antiserum CM1), proliferating cell nuclear antigen (PCNA) labeling index, DNA ploidy (by flow cytometry), histopathological features, prognosis and recurrence rate. RESULTS: The two types of tumors differed with respect to patient age, location, morphology, pattern of genetic lesions and type of tumor recurrences. Twenty-five percent of the patients with MC and 9% of those with nMC (p = 0.04) were under 50 years of age. The incidences of right MC and left MC were similar, while the majority of the nMC were located on the left side (p = 0.04). The MC were of higher grade and their margins more infiltrative than those of the nMC (p = 0.001 and p = 0.01, respectively), p53 nuclear staining was observed less frequently in the MC than in the nMC (30% vs 55%; p = 0.03). The PCNA labeling index was higher in the nMC (46% vs 21%; p = 0.05). We observed no significant differences with respect to tumor stage, incidence of vascular invasion or prevalence of lymphocytic infiltration. The prognosis was similar in both groups, although their recurrence patterns differed, with a tendency toward locoregional recurrence in the cases of MC. CONCLUSION: These findings suggest that, despite their similar prognoses, these two types of lesions are epidemiologically, phenotypically and genotypically different and, thus, result from distinct carcinogenic pathways.     

Genetic analysis of heat shock response in three Drosophila species of the obscura group

Heat shock response was investigated in three species of the obscura group of the Drosophila genus (D. subobscura, D. guanche, and D. madeirensis) by chromosome cytology analysis and [3H]uridine labeling. A set of eight puffs (2C, 15DE, 18C, 27A, 31CD, 85AB, 89A, and 94A) were induced after heat treatments in each of the three species; 18C, 27A, 89A, and 94A were the most heavily labeled in the autoradiograms after the induced conditions. From the in situ results using the major heat shock genes of D. melanogaster as a probe, it was inferred that the 18C, 94A, 89A, and 27A loci of the three obscura group species are homologous to D. melanogaster loci, which contain, HSP82, HSP70, HSP68, and HSPs encoding for the small heat shock proteins, respectively. When this organization was compared with that of D. melanogaster, fewer evolutionary changes, mainly gene duplications, were found to have occurred in the obscura group species than in the D. melanogaster group. In the three species analyzed in this work, as well as in the other Drosophila species studied, the heat shock genes are distributed on D and E Muller's elements, behaving as single copy genes that do not move around the genome.     

Organochlorines in Pleuronectidae: comparison between three tissues of three species inhabiting the Northwest Atlantic

The authors evaluated signal changes in the human primary visual cortex during visual stimulation using functional magnetic resonance imaging (MRI) scanner at 1.5 Tesla. Experiments were performed on 10 normal volunteers and 2 patients with homonymous hemianopsia. In the normal volunteers, a signal increase was observed on the bilateral primary visual cortex during hemifield stimulation. In one patient with homonymous hemianopsia after cerebral infarction, the signal change was clearly decreased on the affected side. In the other patient, who was recovering from multiple sclerosis to an almost normal visual field, the fMRI results were within normal limits. These results suggest that it is possible to map noninvasively the activation of the visual stimulation with a clinical MRI system, and that this test might be useful as an objective method of visual field examination.     

A role of Ultrabithorax in morphological differences between Drosophila species

The mechanisms underlying the evolution of morphology are poorly understood. Distantly related taxa sometimes exhibit correlations between morphological differences and patterns of gene expression, but such comparisons cannot establish how mechanisms evolve to generate diverse morphologies. Answers to these questions require resolution of the nature of developmental evolution within and between closely related species. Here I show how the detailed regulation of the Hox gene Ultrabithorax patterns trichomes on the posterior femur of the second leg in Drosophila melanogaster, and that evolution of Ultrabithorax has contributed to divergence of this feature among closely related species. The cis-regulatory regions of Ultrabithorax, and not the protein itself, appear to have evolved. This study provides experimental evidence that cis-regulatory evolution is one way in which conserved proteins have promoted morphological diversity.     

Hpall endonuclease distinguishes between two species in the Anopheles funestus group

New surgical treatment modalities have been developed for patients with anal incontinence resulting from extensive sphincter destruction and in whom standard sphincter repair has failed. These new modalities include the transposition of striated skeletal muscles combined with implantation of neurostimulators, artificial sphincters based on the same principle as artificial urinary sphincters, and direct sacral nerve stimulation. In a few reported series muscle transposition in combination with neurostimulation has given a satisfactory continence in 50-70% of the patients. The same is true for the smaller series published on artificial anal sphincters, whereas the results of sacral nerve stimulation have thus far been reported in only a few patients. The selection of patients and the performance of these procedures should be limited to few specialist centres.     

Longitudinal study of susceptibilities of species of the Bacteroides fragilis group to five antimicrobial agents in three medical centers

A total of 579 clinical isolates of the Bacteroides fragilis group collected from three Canadian hospitals were tested for susceptibility to five antimicrobial agents by using an agar dilution method. During the 4-year survey, isolates from intra-abdominal infections were collected from the following sites: abdominal abscesses (48%), peritoneal fluid (39%), blood (10%), and bile (3%). B. fragilis was the most prevalent species (35.4%), followed by B. thetaiotaomicron (19.2%), B. ovatus (15.9%), and B. vulgatus (11%). No metronidazole- or imipenem-resistant strains were found during the survey. Resistance profiles varied among the different species tested: 7.8, 2.9, and 7.3% of B. fragilis strains (n = 205) and 68.1, 17.2, and 9.4% of non-B. fragilis strains (n = 373) were resistant to cefotetan, cefoxitin, and clindamycin, respectively. B. fragilis and B. vulgatus demonstrated lower resistance rates than B. thetaiotaomicron, B. ovatus, B. distasonis, and B. caccae. During the study, rates of resistance to cefotetan and clindamycin fluctuated but rates of resistance to cefoxitin increased, particularly at one center. These data indicate a need to determine the susceptibility patterns of the B. fragilis group periodically at each hospital.     

Fanconi anemia complementation group E: clinical and cytogenetic data of the first patient

The clinical and cytogenetic data of the first patient proven to belong to the fifth Fanconi anemia complementation group are described. The Turkish boy presented with psychomotoric retardation, growth retardation, retarded bone age, brachycephaly, hypotelorism, epicanthus, syndactyly, brachydactyly, renal dystopia, and cryptorchism. In addition, an asymmetrical skeletal anomaly was seen with a double distal phalanx of the left thumb and hypoplasia of the right thumb. Typical hematological features of the disorder developed, at the age of 2.5 years, about 1 year after diagnosis. Cytogenetic studies confirmed the clinical diagnosis and revealed a spontaneous chromosomal instability and hypersensitivity to the cross-linking agents diepoxybutane and Trenimon. The findings in the patient, who is considered to be the standard for the fifth Fanconi anemia complementation group, are compared with data reported for other patients affected with Fanconi anemia.     

Comparative studies of social behavior in Callicebus and Saimiri: strength and specificity of attraction between male-female cagemates

The strength and specificity of attraction between male and female cagemates was compared in Saimiri and Callicebus, using paired-comparison and single-stimulus methods of testing. Results from both methods showed that the attraction to the cagemate was stronger and more specific in Callicebus than in Saimiri. Sex differences were more pronounced in Saimiri than in Callicebus. Squirrel monkey females were more strongly attracted to strangers than were males and they clearly preferred female strangers over male strangers or their male cagemates.     

Age and sex differences in dyadic and group interaction.

This study examined age and sex differences in dyadic and group interaction in a standardized setting. Seven classes of 4-year-old children and 6 classes of 6-year-old children participated. From these classes, 13 male playgroups and 13 female playgroups were formed. The playgroups were videotaped, and frequencies of dyadic and group interaction were tabulated. Results showed that boys and girls at both ages engaged in similar frequencies but different patterns of dyadic interaction. Only 6-year-old boys, however, interacted in groups. The discussion considers the etiology of these age and sex differences. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Species and sex differences in substrate preference and tongue flick rate in three sympatric species of water snakes (Nerodia).

Tested isolation-reared sympatric water snakes (Nerodia r. rhombifera, N. c. cyclopion, and N. fasciata confluens) in a balanced 2-choice design to determine preference between clean and same-sex conspecific-soiled gravel substrates. Ss included 8 snakes (4 of each sex) of each species. Time spent on each substrate, types of tongue flicking behavior, tail vibration, defecation, and head rubbing were recorded. Species and sex differences were found in the relative time spent on the 2 substrates. Both sexes of N. rhombifera preferred the clean substrate, whereas both sexes of N. cyclopion preferred the soiled substrate, although the difference in time spent on the substrates was small for males. N. fasciata sexes differed in their preference, with the females preferring the soiled substrate and the males preferring, but not so strongly, the clean substrate. The frequencies of the 4 types of tongue extensions differed across species and sexes, with "air" tongue flicks accounting for the most variance. A lower total rate of tongue flicking occurred when the snakes were on the preferred substrate. These species and sex differences may help minimize competition due to dietary overlap between N. rhombifera and N. cyclopion, and between male and female N. fasciata. (33 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Islets and diffuse endocrine component in the pancreas of three red frogs species: relationships between endocrine and exocrine tissue

The endocrine pancreas of three red frogs was studied immunohistochemically. It consisted of islets and diffuse endocrine cells. The islets showed a mammalian-like arrangement with a central core of B cells and a peripheral mantle of A/PP cells. A few D and VIP cells were also present. Several regulatory peptides were co-localized in the same endocrine cells by consecutive sections and double-labeling studies. The A/PP cells were formed by subpopulations of cells showing various types of immunoreactivity and varying degrees of immunolabeling. Generally, glucagon/pancreatic polypeptide, glucagon/pancreatic polypeptide/peptide tyrosine tyrosine and glucagon/pancreatic polypeptide/neuropeptide tyrosine immunoreactivities were present in the islets and in the endocrine cells scattered throughout the exocrine parenchyma (the diffuse component). Some specimens, mainly belonging to Rana dalmatina, showed evident periinsular halos around the islets. The diffuse component was abundant, and mainly contained A/PP cells. It formed a net across the exocrine parenchyma; its interrelationship with the latter might occur by a paracrine mechanism.     

Individual differences in information-processing rate and amount: Implications for group differences in response latency.

Research on group differences in response latency often has as its goal the detection of Group ?×? Treatment interactions. However, accumulating evidence suggests that response latencies for different groups are often linearly related, leading to an increased likelihood of finding spurious overadditive interactions in which the slower group produces a larger treatment effect. The authors propose a rate-amount model that predicts linear relationships between individuals and that includes global processing parameters based on large-scale group differences in information processing. These global processing parameters may be used to linearly transform response latencies from different individuals to a common information-processing scale so that small-scale group differences in information processing may be isolated. The authors recommend linear regression and z-score transformations that may be used to augment traditional analyses of raw response latencies. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Quantitative trait loci affecting differences in floral morphology between two species of monkeyflower (Mimulus)

Conspicuous differences in floral morphology are partly responsible for reproductive isolation between two sympatric species of monkeyflower because of their effect on visitation of the flowers by different pollinators. Mimulus lewisii flowers are visited primarily by bumblebees, whereas M. cardinalis flowers are visited mostly by hummingbirds. The genetic control of 12 morphological differences between the flowers of M. lewisii and M. cardinalis was explored in a large linkage mapping population of F2 plants n = 465 to provide an accurate estimate of the number and magnitude of effect of quantitative trait loci (QTLs) governing each character. Between one and six QTLs were identified for each trait. Most (9/12) traits appear to be controlled in part by at least one major QTL explaining >/=25% of the total phenotypic variance. This implies that either single genes of individually large effect or linked clusters of genes with a large cumulative effect can play a role in the evolution of reproductive isolation and speciation.     

Meta-analytic review of sex differences in group performance.

To examine the impact of sex composition of groups on productivity, a meta-analytic review was conducted on the findings of past laboratory research. Two classes of factors were distinguished to account for any performance differences obtained: (a) task contents or settings that favor the interests and abilities of one sex over the other and (b) group-level factors, such as men's and women's interaction, in particular, the tendency for men in groups to offer opinions and suggestions and the tendency for women to act friendly and agree with others. Overall, all-male groups were found to perform better than all-female ones. This appeared due to tasks or settings that favored men's interests and abilities over women's. The effects of group-level factors, such as interaction style, became apparent when tasks were classified in terms of the type of interaction required for completion. Female group members' interaction apparently facilitated performance at tasks requiring positive social activities, including friendliness and agreement with others. Men's interaction style slightly, although not reliably, facilitated performance on tasks requiring task-oriented behavior, such as giving opinions and suggestions. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Sources of group and individual differences in emerging fraction skills.

Results from a 2-year longitudinal study of 181 children from 4th through 5th grade are reported. Levels of growth in children's computation, word problem, and estimation skills by means of common fractions were predicted by working memory, attentive classroom behavior, conceptual knowledge about fractions, and simple arithmetic fluency. Comparisons of 55 participants identified as having mathematical difficulties to those without mathematical difficulties revealed that group differences in emerging fraction skills were consistently mediated by attentive classroom behavior and conceptual knowledge about fractions. Neither working memory nor arithmetic fluency mediated group differences in growth in fraction skills. It was also found that the development of basic fraction skills and conceptual knowledge are bidirectional in that conceptual knowledge exerted strong influences on all 3 types of basic fraction skills, and basic fraction skills exerted a more modest influence on subsequent conceptual knowledge. Results are discussed with reference to how the identification of potentially malleable student characteristics that contribute to the difficulties that some students have with fractions informs interventions. Also, results will contribute to a future theoretical account concerning how domain-general and domain-specific factors influence the development of basic fraction skills. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Age-related differences in three tests of visual imagery.

Adult age differences were explored on 3 short tests of ability to generate and manipulate mental images. Age-related decrements were found in all 3 tests and were especially marked on the Clock Test. The tests are all reliable, as shown by test–retest reliability coefficients. Correlations also revealed that the Brooks Letter Test and the East–West Test appear to tap one common underlying ability, whereas the Clock Test measured a somewhat different ability. The East–West and Clock tests, in particular, may provide rapid and easily administered assessment of age-related changes in aspects of mental imagery. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Sexual dimorphism and species differences in HVC volumes of cowbirds.

Cowbirds exhibit extensive variation in their social, territorial, and reproductive behaviors. Nissl-stained brain sections of specimens from a previous study (J. C. Reboreda, N. S. Clayton, & A. Kacelnik, 1996) were used to study the gross anatomy of a song control nucleus in 3 South American cowbirds (bay-winged, Molothrus badius; shiny, M. bonariensis; and screaming, M. rufoaxillaris). Cowbird high vocal center (HVC) volumes were consistently higher in males than in females in all 3 species. The largest HVC size of females found in bay-winged cowbirds is consistent with observations that females of this species, but not of the other 2 species, occasionally sing. The extent of the sexual dimorphism of relative HVC size was highest for the sexually dichromatic and promiscuous shiny cowbirds and smaller for the monochromatic and monogamous bay-winged and screaming cowbirds, suggesting that selection pressures associated with morphological traits and social systems are reflected in brain architecture. (PsycINFO Database Record (c) 2010 APA, all rights reserved)