Rosette-forming glioneuronal tumor: an update.

Rosette-forming glioneuronal tumor (RGNT) is a rare and distinct primary nervous system tumor. The literature on this novel neoplasm is sparse and limited to mostly case reports. Reviews on the characteristics of this tumor are fewer and far between with the latest up to a decade old. We thus provide a comprehensive review of recent literature to characterize presenting symptoms, radiological evidence, treatment options, and prognosis of this novel neoplasm. A Medline search for case reports detailing primary rosette-forming glioneuronal tumors was performed. RGNTs are a benign tumor of indolent course with mixed glial and neurocytic components. There is a slight female predominance with mean age of presentation at 23.57 years. Headaches, visual disturbances, and nausea and vomiting are the most common symptoms. Most RGNTs have solid and cystic components, arising most frequently in the fourth ventricle or cerebellum. Management is usually through surgery with gross total resection (GTR) providing better prognosis.

Role of Tetra Amino Acid Motif Properties on the Function of Protease-Activatable Viral Vectors.

Protease-activatable viruses (PAV) based on adeno-associated virus have previously been generated for gene delivery to pathological sites characterized by elevated extracellular proteases. "Peptide locks", composed of a tetra-aspartic acid motif flanked by protease cleavage sequences, were inserted into the virus capsid to inhibit virus-host cell receptor binding and transduction. In the presence of proteases, the peptide locks are cleaved off the capsid, restoring the virus' ability to bind cells and deliver cargo. Although promising, questions remained regarding how the peptide locks prevented cell binding. In particular, it was unclear if the tetra-amino acid (4AA) motif blocks receptor binding via electrostatic repulsion or steric obstruction. To explore this question, we generated a panel of PAVs with lock designs incorporating altered 4AA motifs, each wielding various chemical properties (negative, positive, uncharged polar, and hydrophobic) and characterized the resultant PAV candidates. Notably, all mutants display reduced receptor binding and decreased transduction effciency in the absence of proteases, suggesting simple electrostatics between heparin and the D4 motif do not play an exclusive role in obstructing virus-receptor binding. Even small hydrophobic (A4) and uncharged polar (SGGS) motifs confer a reduction in heparin binding compared to the wild type. Furthermore, both uncharged polar N4 and Q4 mutants (comparable in size to the D4 and E4 motifs respectively, but lacking the negative charge) demonstrate partial ablation of heparin binding. Collectively, these results support a possible dual mechanism of PAV lock operation, where steric hindrance and electrostatics make nonredundant contributions to the disruption of virus-receptor interactions. Finally, because of high virus titer production and superior capsid stability, only the negatively charged 4AA motifs remain viable design choices for PAV construction. Future studies probing the structure-function relationship of PAVs will further expand its promise as a gene delivery vector able to target diseased tissues exhibiting elevated extracellular proteases.

Robust cross-links in molluscan adhesive gels: testing for contributions from hydrophobic and electrostatic interactions.

The cross-linking interactions that provide cohesive strength to molluscan adhesive gels were investigated. Metal-based interactions have been shown to play an important role in the glue of the slug Arion subfuscus (Draparnaud), but other types of interactions may also contribute to the glue's strength and their role has not been investigated. This study shows that treatments that normally disrupt hydrophobic or electrostatic interactions have little to no effect on the slug glue. High salt concentrations and non-ionic detergent do not affect the solubility of the proteins in the glue or the ability of the glue proteins to stiffen gels. In contrast, metal chelation markedly disrupts the gel. Experiments with gel filtration chromatography identify a 40 kDa protein that is a central component of the cross-links in the glue. This 40 kDa protein forms robust macromolecular aggregations that are stable even in the presence of high concentrations of salt, non-ionic detergent, urea or metal chelators. Metal chelation during glue secretion, however, may block some of these cross-links. Such robust, non-specific interactions in an aqueous environment are highly unusual for hydrogels and reflect an intriguing cross-linking mechanism.

Forced convective head cooling device reduces human cross-sectional brain temperature measured by magnetic resonance: a non-randomized healthy volunteer pilot study.

BACKGROUND: This pilot study in five healthy adult humans forms the pre-clinical assessment of the effect of a forced convective head cooling device on intracranial temperature, measured non-invasively by magnetic resonance spectroscopy (MRS). METHODS: After a 10 min baseline with no cooling, subjects received 30 min of head cooling followed by 30 min of head and neck cooling via a hood and neck collar delivering 14.5 degrees C air at 42.5 litre s(-1). Over baseline and at the end of both cooling periods, MRS was performed, using chemical shift imaging, to measure brain temperature simultaneously across a single slice of brain at the level of the basal ganglia. Oesophageal temperature was measured continuously using a fluoroptic thermometer. RESULTS: MRS brain temperature was calculated for baseline and the last 10 min of each cooling period. The net brain temperature reduction with head cooling was 0.45 degrees C (SD 0.23 degrees C, P=0.01, 95% CI 0.17-0.74 degrees C) and with head and neck cooling was 0.37 degrees C (SD 0.30 degrees C, P=0.049, 95% CI 0.00-0.74 degrees C). The equivalent net reductions in oesophageal temperature were 0.16 degrees C (SD 0.04 degrees C) and 0.36 degrees C (SD 0.12 degrees C). Baseline-corrected brain temperature gradients from outer through intermediate to core voxels were not significant for either head cooling (P=0.43) or head and neck cooling (P=0.07), indicating that there was not a significant reduction in cooling with progressive depth into the brain. CONCLUSIONS: Convective head cooling reduced MRS brain temperature and core brain was cooled.

Macaques co-immunized with SIVgag/pol-HIVenv and IL-12 plasmid have increased cellular responses.

BACKGROUND: The cell mediated immune profiles following immunization with a recombinant DNA vaccine was assessed in the simian-human immunodeficiency virus (SHIV) and Macaque model. Earlier work demonstrated increased numbers of antigen specific CD8 and CD4 effector cells able to secrete IFN-gamma. METHOD: The vaccine strategy included co-immunization of a DNA based vaccine alone or in combination with a macaque IL-12 expressing plasmid (pmacIL12). Antigen activated lymphocytes were studied for activation of a set of immunological molecules. RESULTS: The current study demonstrates lymphocytes isolated and activated from the group that was immunized with DNA and pmacIL12 had a higher level of IFN-gamma producing cells. We also observed a different immunological profile when comparing the cells isolated from macaques immunized with DNA as compared to those animals that also received pmacIL12. CONCLUSION: The observed immune profiles are reflective of the co-delivery of pmacIL12 and demonstrates that IL-12 can increase the magnitude and polyfunctionality of the cellular immune response.

Spontaneous resolution of carotid stenosis--a case for routine preoperative duplex ultrasound.

Spontaneous resolution of carotid stenosis has not been previously reported in the context of preoperative duplex ultrasound scanning, although it has been described as a recognizable phenomenon in the past. We report a case in whom significant carotid stenosis was noted at the time of listing for surgery on both duplex ultrasound and MRA. On preoperative imaging there was resolution of the lesion and surgery was avoided. This case emphasises that spontaneous resolution of carotid stenosis can occur and that preoperative duplex is useful as a prelude to surgery and can prevent unwarranted intervention.

Targeted antigen delivery to antigen-presenting cells including dendritic cells by engineered Fas-mediated apoptosis.

Immunity to tumors as well as to viral and bacterial pathogens is often mediated by cytotoxic T lymphocytes (CTLs). Thus, the ability to induce a strong cell-mediated immune response is an important requirement of novel immunotherapies. Antigen-presenting cells (APCs), including dendritic cells (DCs), are specialized in initiating T-cell immunity. Harnessing this innate ability of these cells to acquire and present antigens, we sought to improve antigen presentation by targeting antigens directly to DCs in vivo through apoptosis. We engineered Fas-mediated apoptotic death of antigen-bearing cells in vivo by co-expressing the immunogen and Fas in the same cell. We then observed that the death of antigen-bearing cells results in increased antigen acquisition by APCs including DCs. This in vivo strategy led to enhanced antigen-specific CTLs, and the elaboration of T helper-1 (Th1) type cytokines and chemokines. This adjuvant approach has important implications for viral and nonviral delivery strategies for vaccines or gene therapies.

Dietary creatine supplementation does not affect some haematological indices, or indices of muscle damage and hepatic and renal function.

BACKGROUND: The use of creatine (Cr) as a nutritional supplement to aid athletic performance has gained widespread popularity among athletes. However, concerns have recently been expressed over potentially harmful effects of short and long term Cr supplementation on health. METHODS: Forty eight young healthy subjects were randomly allocated to three experimental protocols aimed at elucidating any potential health risks associated with five days (20 g/day) to nine weeks (3 g/day) of Cr supplementation. Venous blood samples were collected before and after periods of Cr supplementation and were analysed for some haematological indices, and for indices of hepatic, muscular, and renal dysfunction. FINDINGS: All measured indices were well within their respective normal range at all times. Serum creatinine concentration tended to be increased the day after Cr supplementation. However, values had returned to baseline six weeks after the cessation of supplementation. These increases were probably attributable to increased creatinine production rather than renal dysfunction. No indication of impairment to the haematological indices measured, hepatic function, or muscle damage was apparent after Cr supplementation. INTERPRETATION: These data provide evidence that there are no obvious adverse effects of acute or more chronic Cr supplementation on the haematological indices measured, nor on hepatic, muscle, and renal function. Therefore there is no apparent health risk associated with Cr supplementation to healthy people when it is ingested in quantities that have been scientifically proven to increase muscle Cr stores.

Communication patterns and decision making among parents and health care providers in the neonatal intensive care unit: a case study.

This case study illustrates salient issues in the communication and decision making of parents in a neonatal intensive care unit. The case provides descriptions that may be typical features of interaction between parents and professionals in a neonatal intensive care unit. Conclusions are drawn from this case with recommendations for practice.

Role of submaximal exercise in promoting creatine and glycogen accumulation in human skeletal muscle.

We examined the effect of glycogen-depleting exercise on subsequent muscle total creatine (TCr) accumulation and glycogen resynthesis during postexercise periods when the diet was supplemented with carbohydrate (CHO) or creatine (Cr) + CHO. Fourteen subjects performed one-legged cycling exercise to exhaustion. Muscle biopsies were taken from the exhausted (Ex) and nonexhausted (Nex) limbs after exercise and after 6 h and 5 days of recovery, during which CHO (CHO group, n = 7) or Cr + CHO (Cr+CHO group, n = 7) supplements were ingested. Muscle TCr concentration ([TCr]) was unchanged in both groups 6 h after supplementation commenced but had increased in the Ex (P < 0.001) and Nex limbs (P < 0.05) of the Cr+CHO group after 5 days. Greater TCr accumulation was achieved in the Ex limbs (P < 0.01) of this group. Glycogen was increased above nonexercised concentrations in the Ex limbs of both groups after 5 days, with the concentration being greater in the Cr+CHO group (P = 0.06). Thus a single bout of exercise enhanced muscle Cr accumulation, and this effect was restricted to the exercised muscle. However, exercise also diminished CHO-mediated insulin release, which may have attenuated insulin-mediated muscle Cr accumulation. Ingesting Cr with CHO also augmented glycogen supercompensation in the exercised muscle.

MRI appearance of clear cell hidradenoma.

We present the first reported MR imaging findings of a histologically proven clear cell hidradenoma. A fluid level was noted on all pulse sequences in this lesion, which demonstrated a prominent hemorrhagic component on sectioning. The presence of an enhancing nodule was also noted, differentiating this lesion from a post-traumatic hematoma. Fluid levels in a well-defined subcutaneous soft tissue mass should suggest the possibility of a hidradenoma.

A comparison of transdermal fentanyl versus epidural morphine for analgesia in dogs undergoing major orthopedic surgery.

Postoperative analgesia provided by transdermal fentanyl was compared with that provided by epidural morphine in dogs undergoing major orthopedic surgery. Dogs randomly were assigned to receive either a 100 microg per hour transdermal fentanyl patch 24 hours prior to surgery (n=8) or epidural morphine (0.1 mg/kg body weight) administered following induction of anesthesia (n=10). Temperature, heart rate, respiratory rate, and pain score were recorded prior to surgery and zero, six, 18, 30, and 42 hours after surgery. Blood samples were collected from the dogs in the transdermal fentanyl group beginning 24 hours preoperatively to 42 hours postoperatively. Fentanyl concentrations were determined by radioimmunoassay. When all time periods after surgery were combined, dogs in the transdermal fentanyl group were experiencing significantly less pain after surgery than dogs given epidural morphine. The transdermal fentanyl provided analgesia after major orthopedic surgery greater than or equivalent to that of epidural morphine.

Problem-based learning in the NICU.

Problem-based learning has been used by individuals from various professions and in a wide array of academic and clinical settings. The primary benefits of PBL are that it allows learners to be actively engaged in the learning process and that it can help to strengthen problem-solving skills for learners on any level. PBL can be used effectively in the NICU for both novice and advanced practice nurses.

Cultural diversity and transcultural nursing as they impact health care.

This article examines and critiques what can be broadly defined as "culturally sensitive nursing practice." The authors argue that both past and present research on culturally sensitive nursing practice, regardless of which branch of such practice it subscribes to (transcultural, cross-cultural, multicultural, intercultural, international, and so forth), is not sufficiently based in a sociopolitical context. As a result, there is not significant positive improvement in health care outcomes for patients from traditionally under-represented social membership groups (i.e., groups based on race, gender, socioeconomic class, etc.). Realizing sincere and affective culturally sensitive nursing practice is contingent upon the development and implementation of a comprehensive, sociopolitically conceptualized multicultural nursing education curriculum and pedagogy.

Clinically inapparent tuboovarian actinomycosis in a woman with an IUD. A case report.

BACKGROUND: The consequences and management of asymptomatic Actinomyces-like organisms detected on cervical cytologic smears continue to be controversial. CASE: A unilateral tuboovarian actinomycotic abscess was discovered in a woman who had undergone a hysterectomy for uterine leiomyomas. She had had an intrauterine device in place for many years without any symptoms of pelvic inflammatory disease. CONCLUSION: Ascending infection of the upper genital tract by Actinomyces may be clinically inapparent. When Actinomyces-like organisms aer detected on cervical cytologic smears, removal of an intrauterine device should be considered.

Applying research in the NICU.

It is important for all nurses to apply research findings to their practice. Research is a powerful tool, and it is essential that NICU nurses use it to substantiate our actions. When we do, we empower ourselves to advocate for better care for our special patients and their families.

Malignant mesenchymoma associated with an unusual vasoinvasive metastasis in a dog.

A case of a malignant mesenchymoma with an unusual, vasoinvasive, metastatic behavior in a three-year-old, intact female basset hound is presented. Malignant mesenchymomas are rare neoplasms in humans and in dogs. No previous reports of a malignant mesenchymoma with vasoinvasive metastasis in the dog were found in the literature. The constituent neoplasms are discussed in relation to reports in the human and veterinary literature, and a potential etiology for this unique presentation is hypothesized.

Specific immune induction following DNA-based immunization through in vivo transfection and activation of macrophages/antigen-presenting cells.

The initiation of an adaptive immune response requires Ag presentation in combination with the appropriate activation signals. Classically, Ag presentation and immune activation occur in the lymph node and spleen, where a favorable organ architecture and rich cellular help can enhance the process. Recently, several investigators have reported the use of DNA expression cassettes to elicit cellular and humoral immunity against diverse pathogens. Although the immune mechanisms involved are still poorly understood, plasmid inoculation represents a model system for studying immune function in response to invading pathogens. In this report, we demonstrate the presence of activated macrophages or dendritic cells in the blood lymphocyte pool and peripheral tissues of animals inoculated with DNA expression cassettes. These cells are directly transfected in vivo, present Ag, and display the surface proteins CD80 and CD86. Our studies indicate that these cells function as APC and can activate naive T lymphocytes. They may represent an important first step APC in genetic immunization and natural infection.