Major venom proteins of the fire ant Solenopsis invicta: insights into possible pheromone-binding function from mass spectrometric analysis.

Proteins in the venom of the fire ant Solenopsis invicta have been suggested to function in pheromone binding. Venom from queens and workers contains different isoforms of these proteins, consistent with the differing pheromones they secrete, but questions remain about the venom protein composition and glandular source. We found that the queen venom contains a previously uncharacterized pheromone-binding protein paralogue known as Sol i 2X1. Using imaging mass spectrometry, we located the main venom proteins in the poison sac, implying that pheromones might have to compete with venom alkaloids for binding. Using the known structure of the worker venom protein Sol i 2w, we generated three-dimensional homology models of the worker venom protein Sol i 4.02, and of the two main venom proteins in queens and female alates, Sol i 2q and Sol i 2X1. Surprisingly, the models show that the proteins have relatively small internal hydrophobic binding pockets that are blocked by about 10 amino acids of the C-terminal region. For these proteins to function as carriers of hydrophobic ligands, a conformational change would be required to displace the C-terminal region, somewhat like the mechanism known to occur in the silk moth pheromone-binding protein.

Evolved pseudo-wavelet function to optimally decompose sEMG for automated classification of localized muscle fatigue.

The purpose of this study was to develop an algorithm for automated muscle fatigue detection in sports related scenarios. Surface electromyography (sEMG) of the biceps muscle was recorded from ten subjects performing semi-isometric (i.e., attempted isometric) contraction until fatigue. For training and testing purposes, the signals were labelled in two classes (Non-Fatigue and Fatigue), with the labelling being determined by a fuzzy classifier using elbow angle and its standard deviation as inputs. A genetic algorithm was used for evolving a pseudo-wavelet function for optimising the detection of muscle fatigue on any unseen sEMG signals. Tuning of the generalised evolved pseudo-wavelet function was based on the decomposition of twenty sEMG trials. After completing twenty independent pseudo-wavelet evolution runs, the best run was selected and then tested on ten previously unseen sEMG trials to measure the classification performance. Results show that an evolved pseudo-wavelet improved the classification of muscle fatigue between 7.31% and 13.15% when compared to other wavelet functions, giving an average correct classification of 88.41%.

Classification of localized muscle fatigue with genetic programming on sEMG during isometric contraction.

Genetic Programming is used to generate a solution that can classify localized muscle fatigue from filtered and rectified surface electromyography (sEMG). The GP has two classification phases, the GP training phase and a GP testing phase. In the training phase, the program evolved with multiple components. One component analyzes statistical features extracted from sEMG to chop the signal into blocks and label them using a fuzzy classifier into three classes: Non-Fatigue, Transition-to-Fatigue and Fatigue. The blocks are then projected onto a two-dimensional Euclidean space via two further (evolved) program components. K-means clustering is then applied to group similar data blocks. Each cluster is then labeled according to its dominant members. The programs that achieve good classification are evolved. In the testing phase, it tests the signal using the evolved components, however without the use of a fuzzy classifier. As the results show the evolved program achieves good classification and it can be used on any unseen isometric sEMG signals to classify fatigue without requiring any further evolution. The GP was able to classify the signal into a meaningful sequence of Non-Fatigue-->Transition-to-Fatigue-->Fatigue. By identifying a Transition-to Fatigue state the GP can give a prediction of an oncoming fatigue. The genetic classifier gave promising results 83.17% correct classification on average of all signals in the test set, especially considering that the GP is classifying muscle fatigue for ten different individuals.

The parent's perspective.

"A wonderful son of whom I am very proud": the mother of a 14 year old boy with attention deficit/hyperactivity disorder describes her experiences.

A school-community partnership for at-risk students in Pennsylvania.

This four-year, school-community health improvement project addressed fragmentation and under-utilization of services of an at risk population in a county in central Pennsylvania. A population profile was developed that included demographic, attitudinal, and behavioral information as well as information related to liabilities and assets that affect resiliency and decrease or increase the likelihood of academic success. The profile was used in the planning and implementation of risk-reduction strategies that promote a healthy family and, in turn, a healthy community. More than 50 local, state, and national organizations as well as individuals volunteered or provided services at each school. The project produced a 22% increase in parental involvement in school activities; a 15% increase in parental involvement in educational sessions; a 22% increase in volunteers within the school; and a 75% decrease in truancy.

Mechanism of action of pulsed high electric field (PHEF) on the membranes of food-poisoning bacteria is an 'all-or-nothing' effect.

Salmonella typhimurium (CRA 1005) was more sensitive than Listeria monocytogenes (NCTC 11994) to pulsed high electric field (PHEF) treatment in distilled water (10, 15 and 20 kV/cm), 10 mM tris-maleate buffer pH 7.4 (15 kV/cm) and model beef broth (0.75% w/v: 15 kV/cm). Sublethal injury could not be detected using a selective medium plating technique, indicating that bacterial inactivation by PHEF may be an 'all-or-nothing' event. PHEF-induced membrane permeabilization resulted in increased UV-leakage and a decreased ability of L. monocytogenes to maintain a pH gradient.

Applying cooperative learning in health education practice.

Cooperative learning encompasses both a teaching philosophy and instructional methods that encourage students to work together to maximize learning. This article examines the rationale for incorporating cooperative learning in health education, reviews cooperative learning basics, and provides an example of cooperative learning technique in health education.

In situ distribution of the beta-subunit of platelet-derived growth factor receptor in nonneoplastic tissue and in soft tissue tumors.

The distribution of the beta-subunit of platelet-derived growth factor receptor (PDGFR-beta) was assessed by a sensitive immunoalkaline phosphatase technique using the monoclonal antibody PR7212. Frozen tissue sections of several nonneoplastic human tissues were stained along with 42 soft tissue sarcomas, 16 benign soft tissue proliferations, and 7 epithelial tumors. In all nonneoplastic tissue, there was intense labeling of cell processes of perivascular fibroblasts or pericytes in and about the walls of muscular blood vessels and of fibroblast cell processes around some glandular and ductal epithelia. No PDGFR-beta was found in the endothelial cells of muscular arteries and veins, but cells of uncertain identity within some capillaries were immunoreactive and the possibility that endothelial cells of some small capillaries express PDGFR-beta could not be excluded. In kidney there was strong labeling of glomerular mesangial cells and interstitial fibroblasts. Some histological types of soft tissue sarcomas were uniformly and strongly labeled with anti-PDGFR-beta, but other types were infrequently labeled or unreactive. The order of decreasing frequency and strength of labeling of the various types of benign and malignant soft tissue proliferations was as follows: benign fibromatosis and neurofibroma greater than malignant fibrous histiocytoma greater than liposarcoma greater than leiomyosarcoma greater than rhabdomyosarcoma. No tumor cell labeling was detected in epithelioid, synovial or clear cell sarcomas, leiomyomas, or carcinomas, but there was usually strong labeling of fibroblast and/or pericyte cell processes within tumor, especially around blood vessels. We conclude that PDGFR-beta is strongly expressed by vascular and stromal tissues of most tumors and normal organs and by tumor cells of several types of soft tissue tumors and proliferations, most notably those of fibroblastic origin.

In situ distribution of oncogene products and growth factor receptors in breast carcinoma: c-erbB-2 oncoprotein, EGFr, and PDGFr-beta-subunit.

An increasing body of evidence suggests that breast tumour growth is mediated by oncogene products and growth factors which are or which act through cell surface receptors. The aims of the present study were to determine how three of these receptors, c-erbB-2 protein, epidermal growth factor receptor (EGFr) and the beta-subunit of platelet-derived growth factor receptor (PDGFr-beta-subunit), can effectively be demonstrated by immunohistochemical methods in breast tumors, how these receptors are distributed at the cellular level and how their expression correlates with well-established prognostic indicators including hormone receptors and proliferative index. We examined frozen tissue sections of 50 invasive human breast carcinomas, including 45 ductal, four lobular, and one mucinous tumours, by immunocytochemical methods to determine the in situ distributions of c-erbB-2, EGFr, and PDGFr-beta-subunit. We compared staining for c-erbB-2 protein in frozen sections with that in paraffin sections of the same 50 tumours. The immunohistochemical labelling results were compared with tissue hormone receptor content and growth fraction determined by Ki-67 labelling. Strong labelling of tumour cells in frozen sections was detected in 22% of cases, all of the ductal type, stained with rabbit antiserum to c-erbB-2. Labelling for c-erbB-2 protein was generally weaker in paraffin sections than in frozen sections and in six of 11 positive cases, specific staining could be detected only in frozen sections. In immunostains with monoclonal antibody to EGFr, rare cells within tumour were labelled in 60% of the carcinomas. Using a monoclonal antibody to the beta-subunit of PDGFr, consistent labelling of fibrillary cellular processes in the walls of blood vessels and in fibrous stroma around tumour cell nests was detected, but there was no labelling of tumour cells themselves. C-erbB-2 oncoprotein positive tumours were found to be more often oestrogen receptor negative (P less than 0.005) or oestrogen and progesterone receptor negative (P less than 0.01) than c-erbB-2 negative tumours. No significant correlation was observed between c-erbB-2 expression and Ki-67 growth fraction.

Protective immunity and vaccines to schistosomiasis.

Human schistosomiasis is a major health problem in endemic areas and it is estimated that world-wide more than 200 million people are infected. Active infection, exposure to attenuated parasites, or appropriate immunization with parasite extracts or purified antigens can lead to partial protection against challenge infections. Studies of the humoral and cellular mechanisms responsible for these forms of resistance, and the definition, purification or production of recombinant moieties responsible for the induction of immunity are currently the focus of considerable research efforts.

Assessment of hormone receptors in breast carcinoma by immunocytochemistry and image analysis. I. Progesterone receptors.

Frozen sections of 30 breast carcinomas were stained for progesterone receptors (PRs) using a rat monoclonal primary antibody and an alkaline phosphatase-antialkaline phosphatase technique. The micro-TICAS image analysis system was used for evaluation of the staining, with the results obtained by image analysis compared with the results of biochemical assays for PR. Strong positive/negative concordance (90%) was observed between the immunohistochemical and biochemical assays. However, the numerical values of the positive cases in the two assays did not correlate well, possibly because the biochemical assay does not take tumor cellularity into account. Three PR distribution patterns, designated A, B and C, were identified by image analysis among the breast tumors. In the type A pattern, tumor cell nuclei were diffusely and uniformly labeled. In type B, both clearly negative as well as distinctly positive cells were present. In type C tumors, a broad range of labeling reactions (from negative to intensely positive) was observed. These results imply (1) that the PR content of human breast carcinoma may be accurately and objectively assessed by the image analysis of immunohistochemically stained frozen sections, (2) that image analysis may provide a more accurate estimate of the cellular content of PR than do biochemical assays and (3) that PR distribution patterns obtained through image analysis permit the consistent appraisal of intratumoral heterogeneity of PR expression, which is potentially of prognostic importance.

Assessment of hormone receptors in breast carcinoma by immunocytochemistry and image analysis. II. Estrogen receptors.

Frozen sections of 30 invasive breast carcinomas were stained for estrogen receptors (ERs) and the tumor cell proliferative rate by an immunoalkaline phosphatase technique. The stained sections were evaluated for ER by the microTICAS image analysis system. Seventeen tumors were ER positive and 13 were ER negative by image analysis. There was 93% concordance between the ER results obtained by image analysis and those obtained by biochemical methods. One case that was ER negative by image analysis was weakly positive by biochemical assay; a second case was ER positive by image analysis but ER negative by biochemical assay. Twelve of the 17 ER-positive tumors were diffusely positive while 5 displayed considerable intratumoral heterogeneity, with tumor cells exhibiting a broad range of intensity of receptor expression. In most cases, the image analysis ER status coincided with the progesterone receptor (PR) status, but in a large minority of cases (41%) the ER status and the PR status differed. Tumors with a high growth fraction (greater than 30%), as measured by Ki-67 immunostaining, were uniformly ER negative. The results of this investigation suggest that immunohistochemical staining of frozen sections for ER aided by automated image analysis (1) reliably detects the receptor in breast carcinoma, (2) allows for the assessment of heterogeneity within tumors and (3) may be used as part of a panel of antibodies to markers of potential prognostic importance in a single small tissue sample.

Immunohistochemical detection of steroid receptors in a case of pulmonary lymphangioleiomyomatosis.

Abnormal proliferation of smooth muscle cells in pulmonary lymphangioleiomyomatosis (LAM) is thought to be influenced by estrogen and progesterone. However, the results of previous studies using cytosolic methods to measure estrogen and progesterone receptor content in lung tissue from these patients have been inconsistent. We used immunohistochemical methods to study the tissue distribution of estrogen and progesterone receptors in LAM as well as in smooth muscle of several other organs, including histologically normal lung, colon, bladder, prostate, uterus, and uterine leiomyomas. Progesterone receptor was expressed strongly and estrogen receptor more weakly by the abnormal myoid cells of LAM. Hormone receptors were absent from all other constituents of lung tissue in our patient. These findings were similar to those in histologically normal myometrium and uterine leiomyomas. Although we found focal labeling of prostatic stromal cells with anti-progesterone receptor, no other smooth muscle tissue expressed either estrogen or progesterone receptor. We conclude that LAM is an abnormal proliferation of smooth muscle cells that express both estrogen and progesterone receptors.

Relapse prevention: implications for health promotion professionals.

Health promotion and education efforts often are designed to promote behavior changes among clients, students, or participants. The primary emphasis of health promotion has been the initial behavior change process, with little attention directed to follow-up or after-care. The relapse prevention model (RP) presents a strategy to enhance the likelihood of maintaining a behavior change using methods clearly rooted in social learning theory. This article provides an overview of the RP model and examples of the implication of RP for health promotion and education programs.

Health promotion efforts in pennsylvania schools.

Abstract The purpose of this study was to investigate and describe health promotion efforts within Pennsylvania public schools. A questionnaire was designed which addressed the following areas: demographics, health issues and concerns, health promotion programming, and variables pertinent to describe districts without programs. The sample consisted of 275 superintendents of public school districts, 41 of which indicated the existence of a health promotion program in their district. Superintendents of districts with health promotion programs indicated the following: the most frequently offered programs were physical fitness activities, stress management and weight reduction; programs were most frequently offered during the after school hours; many programs were not open to family and community; and the administration of the programs was most frequently the responsibility of a school administrator. The remaining 234 school districts did not have health promotion programs. The reasons cited by the superintendents included limited financial resources, an uninterested faculty and staff, and lack of school board support.

Synthesis and pharmacological evaluation of some 6-substituted 7-methyl-1,4-dioxa-7-azaspiro[4.5]decanes as potential dopamine agonists.

Three 7-methyl-1,4-dioxa-7-azaspiro[4.5]decanes that contained either the benzyl, 3-indolylmethyl, or 4-indolylmethyl group at the 6-position were synthesized via alkylation of the pyrrolidine enamine of the key intermediate, ethyl 3-oxopiperidine-1-carboxylate. The spirodecane derivatives were evaluated for in vivo central and peripheral dopamine agonist activity. None of the compounds displayed central nervous system activity; however, the 4-indolymethyl analogue exhibited potent dopamine agonist activity in the cat cardioaccelerator nerve assay and possesses an ID50 of 0.095 mumol/kg compared to apomorphine, which possesses an ID50 of 0.0348 mumol/kg in the same assay.

Reproduction of end-location and distance of movement in early and later blinded subjects.

This study examined the ability of early and later blinded subjects to reproduce the end location and distance of preselected arm movements of two different amplitudes (approximately 30 degrees and approximately 60 degrees). Both groups were found to reproduce end location with greater accuracy and less variability than distance. The early blinded subjects were less accurate however, and more variable in their reproductions of both movement cues than the later blinded subjects. The complications of these findings for the role of visual representation in memory for movement are discussed.

Attentional bias and visual field asymmetry.

In mixed list tachistoscopic presentation of abstract words and random shapes, the probability of word and shape stimuli was varied to generate attentional bias and selective activation of the left or right hemispheres. While a right visual field advantage in accuracy was observed for words, and an effect of stimulus probability was observed across both visual fields in reaction time, no interactions were found between attentional bias and visual field asymmetry. The results can therefore be explained without reference to the attentional model and did not provide evidence of hemispheric activation or priming.