Cell surface glycosaminoglycans are not obligatory for Plasmodium berghei sporozoite invasion in vitro

The malaria circumsporozoite (CS) protein binds to glycosaminoglycan chains from heparan sulfate proteoglycans present on the basolateral surface of hepatocytes and hepatoma cells in vitro. When injected into mice, CS protein is rapidly cleared from the blood circulation by hepatocytes. The binding region for the HSPGs is the evolutionarily conserved region II-plus of the CS protein. Here we have asked whether the presence of glycosaminoglycans on the plasma membrane of target cells is required for sporozoite invasion in vitro. Two types of target cells were used: HepG2 cells, which are permissive for Plasmodium berghei sporozoite development into mature exoerythrocytic forms, and CHO cells, in which the intracellular development of the parasites is arrested early after penetration. The invasion of mutant CHO cells expressing undersulfated glycosaminoglycans or no glycosaminoglycans was only inhibited 41-49% or 24-32%, respectively, in comparison to invasion of CHO-K1 cells. Previous cleavage of HepG2 surface membrane glycosaminoglycans with heparinase or heparitinase had no significant inhibitory effect on subsequent P. berghei sporozoite invasion and EEF development in these cells, although the glycosaminoglycan lyase treatments removed over 80% of CS binding sites from the cell surface. These results suggest that although the presence of glycosaminoglycans on the target cell surface enhances sporozoite invasion, glycosaminoglycans are not required for sporozoite penetration or the development of exoerythrocytic forms in vitro.     

PECAM-1 is required for transendothelial migration of leukocytes

Platelet/endothelial cell adhesion molecule 1 (PECAM-1; CD31) is crucial to the process of leukocyte transmigration through intercellular junctions of vascular endothelial cells. A monoclonal antibody to PECAM, or recombinant soluble PECAM, blocks transendothelial migration of monocytes by 70-90%. Pretreating either the monocytes or the endothelial junctions with antibody blocks transmigration. If the endothelium is first activated by cytokines, anti-PECAM antibody or soluble recombinant PECAM again block transmigration of both monocytes and neutrophils. Anti-PECAM does not block chemotaxis of either cell type. Light and electron microscopy reveal that leukocytes blocked in transmigration remain tightly bound to the apical surface of the endothelial cell, precisely over the intercellular junction. Thus, the process of leukocyte emigration can be dissected into three successive stages: rolling, mediated by the selectin class of adhesion molecules; tight adhesion, mediated by the leukocyte integrins and their endothelial cell counter-receptors; and now transmigration, which, based on these studies, requires PECAM-1.     

Question asking: To know that you do not know is not enough.

Effects of prior knowledge on question asking were examined. Fifth graders with little or much prior knowledge had to indicate the meaning of a set of words. Pupils could (a) not ask a question, (b) ask a global question, or (c) ask a specific question. In Study 1, prior knowledge significantly affected the number of questions asked and the pragmatic significance of the questions. In Study 2, selection was contrasted with production of questions. Pupils with little prior knowledge asked fewer specific questions and more global questions in production. The pragmatic significance of the questions was lower for all pupils in production. The pupils' questions were found wanting in information-gathering and communicative qualities. In Study 2, asking for "provisional answers" in advance of question asking strongly stimulated question asking. It presumably enhances commitment, stimulates monitoring, and alleviates social constraints in asking questions. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Myelin proteolipid protein intron 1 sequences do not appear to enhance myelin proteolipid protein gene transcription

Sequences from the first intron of the mouse myelin proteolipid protein (PLP) gene were examined for their ability to modulate PLP gene expression. Glial (N20.1) or nonglial (NIH 3T3) cells were transiently transfected with constructs that contained 1.4 kb of PLP promoter sequence driving luciferase reporter gene expression, as well as various portions of PLP intron 1 DNA. Although these same PLP intron 1 fragments enhanced reporter gene expression from a heterologous basal promoter in a previous study, the results reported here demonstrate that they do not augment PLP promoter activity. Thus, the regulation of PLP cell-type-specific expression, conferred by the first intron, appears to be mediated by an enhancer-independent mechanism.     

The R1 subunit of herpes simplex virus ribonucleotide reductase is a good substrate for host cell protein kinases but is not itself a protein kinase

The N terminus of the R1 subunit of herpes simplex virus type 2 ribonucleotide reductase is believed to be a protein kinase domain mainly because the R1 protein was phosphorylated in a protein kinase assay on blot. Using Escherichia coli and adenovirus expression vectors to produce R1, we found that, whereas the reductase activity of both recombinant proteins was similar, efficient phosphorylation of R1 and casein in the presence of Mg2+ was obtained only with the R1 purified from eukaryotic cells. Phosphorylation of this R1, in solution or on blot, results mainly from the activity of casein kinase II (CKII), a co-purifying protein kinase. Labeling on blot occurs from CKII leakage off the membrane and its subsequent high affinity binding to in vivo CKII-phosphorylated R1. CKII target sites were mapped to an acidic serine-rich segment of the R1 N terminus. Improvement in purification of the R1 expressed in eukaryotic cells nearly completely abolished its phosphorylation potential. An extremely low level of phosphorylation observed in the presence of Mn2+ with the R1 produced in E. coli was probably due to an unidentified prokaryotic protein kinase. These results provide evidence that the herpes simplex virus type 2 R1 does not possess an intrinsic protein kinase activity.     

Murine HIP/L29 is a heparin-binding protein with a restricted pattern of expression in adult tissues

Heparin/heparan sulfate (Hp/HS)-binding proteins are implicated in a variety of cell biological processes including cell adhesion, modulation of blood coagulation, and cytokine/growth factor action. Hp/HS-interacting protein (HIP) has been identified in various adult tissues in humans. HIP supports high affinity, selective binding to Hp/HS, promotes cell adhesion, and modulates blood coagulation activities via Hp/HS-dependent mechanisms. Herein, a murine ortholog of human HIP is described that is 78.8% identical to human HIP and 99.8% identical at the cDNA level and identical at the amino acid level to a previously described murine ribosomal protein, L29. Western blot analyses and immunohistological staining with affinity-purified antibodies generated against two distinct peptide sequences of murine HIP/L29 indicate that HIP/L29 is differentially expressed in adult murine tissues and cell types. In the normal murine mammary epithelial cell line, NMuMG, HIP/L29 is enriched in the 100,000 x g particulate fraction. HIP/L29 can be solubilized from the 100,000 x g particulate fraction with 0.8 M NaCl, suggesting that it is a peripheral membrane protein. HIP/L29 directly binds 125I-Hp in gel overlay assays and requires 0.75 M NaCl for elution from Hp-agarose. In addition, recombinant murine HIP expressed in Escherichia coli binds Hp in a saturable and highly selective manner, compared with other glycosaminoglycans including dermatan sulfate, chondroitin sulfate, keratan sulfate, and hyaluronic acid. Collectively, these data indicate that murine HIP/L29, like its human ortholog, is a Hp-binding protein expressed in a restricted manner in adult tissues.     

Fission yeast wee1 protein kinase is not required for DNA damage-dependent mitotic arrest

Checkpoints maintain the dependency relationships between discrete events in the cell cycle (for example, ensuring mitosis does not occur before DNA replication is complete). In Schizosaccharomyces pombe, mitotic checkpoints monitor DNA synthesis and the presence of DNA damage. The replication-dependent mitotic checkpoint prevents mitosis by inactivating p34cdc2 kinase. The mechanism by which the DNA damage checkpoint interacts with the mitotic machinery is distinct from that used by the replication checkpoint. The activity of p34cdc2 is controlled, in part, by the wee1 protein kinase, which inactivates cdc2 through phosphorylation at tyrosine-15 (ref. 7). Here we report normal mitotic arrest after DNA damage in S. pombe cells in which the wee1 gene is defective or missing. We suggest why these findings contradict a recent report which suggested that the wee1 gene product was required for DNA damage-dependent mitotic arrest.     

What neuroimaging and brain localization can do, cannot do and should not do for social psychology.

Interest in bridging social psychology and neuroscience has seen a significant upsurge. Much of this interest has centered on brain localization--the attempt to relate psychological events to locations of brain events. Although many articles have sought to localize brain activity that supports social behavior, scant attention has been paid to the specific methods to be used in integrating brain localization data into psychological theory. The authors describe 4 strategies psychologists can use to integrate brain localization data and psychological theory, and they consider whether social psychology presents special considerations in the use of these strategies. They conclude that brain localization offers a useful tool for some but not all problems in social psychology, and they discuss the types of problems for which it may and may not prove useful. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Do as I do, not as I say: A behavior-analytic approach to supervision.

There is a limited amount of empirical data on how to train therapists. This article first presents limitations in commonly used training procedures. It then describes a training methodology based on contingent shaping, using video feedback to increase responsiveness to the ongoing client-therapist interactions. The approach attempts to overcome some of the problems encountered when teaching therapy by using primarily rule-governed or direct instruction. The authors describe the therapeutic approach used in this research, provide a clinical illustration of the training procedure, and discuss the role direct instruction plays in this training model. A methodology for determining whether the therapist's behavior changes as a result of training is described, as well as a method for identifying the relationship between the therapist's behavior and subsequent changes in client responding. This methodology is broadly applicable and can be empirically tested and compared with other approaches for its utility in training therapist effectiveness and changing client behavior. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Lessons relevant to psychologists who serve as mentors for international students.

Do you have opportunities to teach, counsel, or mentor international students at your university or in your practice? Do you supervise international students in practica and internships? If so, are you aware of the different cultural backgrounds of your students and their sometimes unique educational and personal needs? This article briefly reviews the literature on mentoring and examines the mentoring relationship with a particular focus on the needs of international students. The authors highlight the difficulties confronting international students learning to cope with a different, challenging, and sometimes bewildering new environment and recommend ways in which psychologists can support international students through mentoring. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The matrix protein of HIV-1 is not sufficient for assembly and release of virus-like particles

There is an expectation for Nursing Development Units (NDUs) to explore and develop the clinical leadership role. This paper describes how 28 Department of Health funded NDUs in England sought to meet this objective. We describe the personal and professional characteristics of NDU clinical leaders (CLs) and their perceived responsibilities. We identify 10 elements which appear to be central to the CL role and together form a core role set of the leader which is applicable, to some extent, across clinical specialties and settings. The position of the CL in the organizational hierarchy emerges as crucial to his/her ability to act on these responsibilities and fulfil a leadership role.     

Rats given dopamine-depleting brain lesions as neonates do not respond to acute homeostatic imbalances as adults.

The 1st and 3rd authors and A. M. Snyder (see record 1984-19832-001) found that rats given near-total dopamine-depleting brain lesions as neonates exhibited none of the severe sensorimotor or ingestive dysfunctions that result when adult rats are given comparable lesions. The present study showed that the apparent sparing of function is incomplete. When tested as adults, male Sprague-Dawley rats that had received intracerebroventricular injections of 6-hydroxydopamine HBr (200 μg) at 3 days of age did not eat in response to acute glucoprivation, nor did they drink water and saline in response to hypovolemia. After receiving these homeostatic challenges, Ss became much less able to simply move about. In contrast, dopamine-depleted Ss ate normally after glucoprivation when they were handled hourly instead of being left alone. Similarly, administration of caffeine permitted them to drink while hypovolemic. Observations suggest that some central neurons other than those containing dopamine are responsible for maintaining behavioral activation in rats after neonatal destruction of dopaminergic fiber systems in the brain and that the homeostatic challenges compromise their function and thereby disrupt behavior. (26 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Modern methods of wound treatment. 1. One wound is not the same as all the others

Papillary carcinoma, the commonest thyroid malignancy, has a good prognosis and low incidence of distant metastases. Brain metastasis is extremely rare with a frequency of about 1% in reported series. In this paper we present the clinical details of one case of histologically proven brain metastasis from papillary thyroid cancer, first presented with neurological symptoms, initially treated with excisional biopsy and radiotherapy in other hospital, without clinical response. The patient was then referred to our service, where he underwent a total thyroidectomy and modified radical neck dissection, with the aim of posterior radioactive iodine treatment for the brain lesion. Unfortunately, he died of neurological complications, two months after the neck treatment. Also presented is a review of the literature of this unusual clinical presentation.     

如何当好矿山工程项目的总设计师

总设计师组织管理能力大小、专业知识面的多少等个人素质直接关系到设计项目的进度和质量,文章从矿山工程项目的角度简要谈谈如何当好总设计师.     

Thirty wrongs do not make a right: Reply to Guilford.

Considers that J. P. Guilford's (see PA, Vol 53:Issue 1) reply to the authors' criticisms of his factor analysis of his structure-of-intellect model has failed to come to grips with evidence indicating that if the number of targeted variables for each factor is 3 or fewer, Procrustes factoring provides no better evidence for structure-of-intellect theory than for any of an infinity of other arbitrarily determined theories. Under these conditions factors can be rotated in such a way as to suggest support for almost any desired solution, and one such solution can be that labeled a replication. Hence the factorial invariance claimed under such conditions can indicate only consistency in the researcher and his methods, not in the phenomena studied. (16 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Plant calcium-dependent protein kinase-related kinases (CRKs) do not require calcium for their activities

In plants, calcium-dependent protein kinases (CDPKs) make up a large family that is characterized by a C-terminal calmodulin(CaM)-like domain. Recently, a novel carrot cDNA clone encoding an atypical CDPK, which has a significantly degenerate sequence in the CaM-like domain, was found and named CDPK-related protein kinase (CRK) [Lindzen, E. and Choi, J.H. (1995) Plant Mol. Biol. 28, 785-797]. We obtained two different cDNA clones from maize which encode CRKs. For the first enzymatic characterization of CRK, a maize cDNA clone was expressed in E. coli. The recombinant protein efficiently phosphorylated casein, a conventional protein substrate. Notably, in this in vitro phosphorylation assay, the kinase activity did not require calcium as an activator. Thus, CRKs were suggested to be novel calcium-independent protein kinases having a degenerate CaM domain, the function of which remains to be elucidated.     

Object names and object functions serve as cues to categories for infants.

Can object names and functions act as cues to categories for infants? In Study 1, 14- and 18-month-old infants were shown novel category exemplars along with a function, a name, or no cues. Infants were then asked to "find another one," choosing between 2 novel objects (1 from the familiar category and the other not). Infants at both ages were more likely to select the category match in the function than in the no-cue condition. However, only at 18 months did naming the objects enhance categorization. Study 2 shows that names can facilitate categorization for 14-month-olds as well when a hint regarding the core meaning of the objects (the function of a single familiarization object) is provided. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Unfortunately, psychosis is not a myth.

Responds to J. E. Teahan's (1982) criticism of the present author's (1969, 1982) study of a schizophrenic woman and her Rorschach record. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Ask not what post-secondary education can do for psychology; ask what psychology can do for post-secondary education.

As psychologists we need to take the lead in reinventing post-secondary education. It is time to go beyond "just teaching"; we need to embrace the scholarship of teaching in order to transcend the research/teaching dichotomy. It is time to be more reflective about our teaching; we need to become more ardent theorists and practitioners of teaching and learning, especially when it comes to digital technologies. It is time to revisit educational research; we need to help post-secondary educators understand how to conduct useful research in this field. (PsycINFO Database Record (c) 2010 APA, all rights reserved)