Radiological diagnosis of drop metastases from paediatric brain tumours using combination of 2D and 3D MRI sequences.

AIM: To evaluate spinal magnetic resonance imaging (MRI) examinations using a combination of two-dimensional (2D) and three-dimensional (3D) MRI sequences for diagnosis of drop metastases. MATERIALS AND METHODS: Fifty-five paediatric patients with primary brain tumours were evaluated for drop metastases at initial presentation using spinal MRI including sagittal 2D T1-weighted (W) contrast-enhanced (+C), axial 3D T1W+C volumetric interpolated breath-hold (VIBE), and sagittal 3D T2W SPACE (Sampling Perfection with Application optimised Contrasts using different flip angle Evolutions). RESULTS: The MRI false-negative rate was 4%, and cerebrospinal fluid (CSF) false-negative rate was 16% (p=0.07). The 3D T1W+C VIBE increased the number of drop metastases detected in 42% of patients. Drop metastases were more conspicuous in 25% of patients on 3D T2W SPACE. CONCLUSION: Spinal MRI examinations including 2D and 3D sequences demonstrate characteristics that may improve radiological diagnosis of drop metastases.

The response of hepatocyte cell volume to hyperthermia and its role in oedema.

A novel mathematical model for hepatocytes and surrounding volume is presented here; in addition to tracking ion transport and diffusion the new model allows for changing cell volume. Using temporally and spatially varying temperature as an input, this paper shows how differences between diffusion coefficients directly influence increases in cell volume. The multiscale nature of the model presents a possible link from established cellular equations to the observed clinical result of oedema present in thermal treatments of cancer.

Mathematical modeling of thermal ablation.

Ablation techniques have become a widespread choice for the treatment of cancerous tumors for which surgical resection techniques have a poor prognosis. The minimally invasive nature and high success rate when performed by experienced clinicians mean that ablation is likely to remain a core technique. However, the success rate can drop off dramatically when less-experienced operators are involved, and it is particularly difficult to kill all of the tumor and only the tumor, given the dynamic nature of the processes that lead to cell death. Mathematical modeling of the response to ablation treatment has a long history. Since the seminal paper of Pennes in 1948, there have been numerous attempts to propose models that are both physiologically accurate and computationally inexpensive. All of these models are based on different principles and assumptions, which may make them suitable only for particular applications. This makes choosing a model very difficult because of the lack of understanding about what the limitations of different assumptions are likely to be and how this influences the necessary computational resources. Here we review the models available in the literature, illustrating how the different assumptions impact upon both their accuracy and computational expense.The primary intentions are to provide a critical scientific review and a practical guide for researchers wishing to use such models in clinical applications.

A two-equation coupled system model for determination of liver tissue temperature during radio frequency ablation.

A model is presented that is an alternative approach to the bio-heat equation for use in radio frequency heating of the liver. The model comprises both a tissue subvolume and a blood subvolume. Separate bio-heat equations are determined for each subvolume, but with an additional term exchanging heat between them, thus creating a coupled system. The derivation for the two coupled differential equations is outlined and sample simulations are presented to demonstrate the importance of considering the two subvolumes separately, even when the blood subvolume is a small fraction of the tissue subvolume.

Electron correlation in Hooke's law atom in the high-density limit.

Closed-form expressions for the first three terms in the perturbation expansion of the exact energy and Hartree-Fock energy of the lowest singlet and triplet states of the Hooke's law atom are found. These yield elementary formulas for the exact correlation energies (-49.7028 and -5.807 65 mE(h)) of the two states in the high-density limit and lead to a pair of necessary conditions on the exact correlation kernel G(w) in Hartree-Fock-Wigner theory.

Retinopathy screening in children and adolescents with diabetes.

Diabetic retinopathy is a complication of diabetes that affects the blood vessels of the retina. The majority of patients with diabetic retinopathy exhibit background retinopathy. In approximately 10% of patients, background retinopathy will progress to sight-threatening retinopathy. The aims of our study were to measure the prevalence of retinopathy among our population and to assess the optimal time of screening children and adolescents with type 1 diabetes.

Increased level of stromal cell-derived factor-1 mRNA in peripheral blood mononuclear cells from children with AIDS-related lymphoma.

A common polymorphism in the 3' untranslated region of the stromal cell-derived factor 1 (also called pre-B-cell-stimulating factor) beta gene transcript, termed SDF1-3'A, has been associated with an increased risk of non-Hodgkin's lymphoma (NHL) in HIV-1-infected, but not in uninfected, individuals. Because the gene variation is located within the 3' untranslated region, the SDF1-3'A may influence the abundance of SDF-1 mRNA, possibly up-regulating the chemokine expression especially in the presence of HIV-1. In the current study, we investigated the levels of SDF-1 mRNA in peripheral blood mononuclear cells and HIV-1 viral load in 84 HIV-1-infected children (0.7 to 18 years of age; median, 5.8), including 12 children who developed NHL during their illnesses (AIDS-NHL group; 8 with SDF1-3'A, 4 with SDF1-wild-type). High level SDF-1 expression was observed in 15 of 34 children with SDF1-3'A as compared with 10 of 50 with wild type (P < 0.03). More notably, the children with AIDS-NHL had significantly elevated levels of SDF-1 mRNA in peripheral blood mononuclear cells, obtained at the time of presentation in 10 children and 8.5 to 19.4 months before (median, 15 months) in 7 children, as compared with the children in the non-NHL group (P < 0.00001). The amounts of cell-associated HIV-1 DNA and singly spliced HIV-1 mRNA were significantly greater in children with AIDS-NHL than those with non-NHL AIDS (P = 0.0052 and 0.011, respectively; stratified by antiretroviral treatment regimen), whereas their serum HIV-1 RNA levels were comparable. Overexpression of SDF-1 and aberrant HIV-1 expression in circulating lymphocytes appear to be linked to the development of AIDS-lymphoma. Additional studies are required to determine whether excessive SDF-1, together with virally encoded factors, is directly involved in the pathogenesis of AIDS-lymphoma.

Changes in gibberellin A(1) levels and response during de-etiolation of pea seedlings.

The level of gibberellin A(1) (GA(1)) in shoots of pea (Pisum sativum) dropped rapidly during the first 24 h of de-etiolation. The level then increased between 1 and 5 d after transfer to white light. Comparison of the metabolism of [(13)C(3)H] GA(20) suggested that the initial drop in GA(1) after transfer is mediated by a light-induced increase in the 2beta-hydroxylation of GA(1) to GA(8). A comparison of the elongation response to GA(1) at early and late stages of de-etiolation provided strong evidence for a change in GA(1) response during de-etiolation, coinciding with the return of GA(1) levels to the normal, homeostatic levels found in light- and dark-grown plants. The emerging picture of the control of shoot elongation by light involves an initial inhibition of elongation by a light-induced decrease in GA(1) levels, with continued inhibition mediated by a light-induced change in the plant's response to the endogenous level of GA(1). Hence the plant uses a change in hormone level to respond to a change in the environment, but over time, homeostasis returns the level of the hormone to normal once the ongoing change in environment is accommodated by a change in the response of the plant to the hormone.

Evidence that auxin promotes gibberellin A1 biosynthesis in pea.

In shoots of the garden pea, the bioactive gibberellin (GA1) is synthesised from GA20, and the enzyme which catalyses this step (a GA 3-oxidase -- PsGA3ox1) is encoded by Mendel's LE gene. It has been reported previously that decapitation of the shoot (excision of the apical bud) dramatically reduces the conversion of [3H]GA20 to [3H]GA1 in stems, and here we show that endogenous GA1 and PsGA3ox1 transcript levels are similarly reduced. We show also that these effects of decapitation are completely reversed by application of the auxin indole-3-acetic acid (IAA) to the 'stump' of decapitated plants. Gibberellin A20 is also converted to an inactive product, GA29, and this step is catalysed by a GA 2-oxidase, PsGA2ox1. In contrast to PsGA3ox1, PsGA2ox1 transcript levels were increased by decapitation and reduced by IAA application. Decapitation and IAA treatment did not markedly affect the level of GA1 precursors. It is suggested that in intact pea plants, auxin from the apical bud moves into the elongating internodes where it (directly or indirectly) maintains PsGA3ox1 transcript levels and, consequently, GA1 biosynthesis.

Spirituality and chronic illness.

PURPOSE: To present a comprehensive overview of spirituality and identify strategies to support the spiritual dimensions of nursing care for people with chronic illness, focusing specifically on HIV-related illness and AIDS. SIGNIFICANCE AND SCOPE: The AIDS crisis has brought new emphasis to the need to develop therapeutic interventions to support the coping resources of people living and dying with chronic illness. Conceptual, theoretical, and empirical knowledge related to spirituality was reviewed, integrated, and interpreted within the context of nursing care for this population, emphasizing the spiritual needs of people with HIV-related illness and AIDS. CONCLUSIONS AND IMPLICATIONS: Spirituality has evolved beyond religious considerations to encompass multidimensional and existential perspectives that are integral to maintaining well-being for the chronically ill. A deeper understanding of spirituality enhances the potential for nurses to identify spiritual needs and incorporate spiritual caring into practice.

Grain dusts and grain plant components vary in their ability to recruit neutrophils.

Occupational exposure to grain dusts can cause bronchitis, particularly to grain sorghum dust. Bronchitis is associated with the presence of increased numbers of neutrophils. To determine how grain dusts could cause neutrophil recruitment to the airways, extract of whole-grain sorghum, corn, and soybean dusts and of pulverized components of these plants were made with Hanks balanced salt solution (HBSS) and used in direct neutrophil chemotaxis experiments. The glume of the grain sorghum plant, the structure holding the seeds in place, caused the migration of the greatest number of neutrophils compared to HBSS [132 +/- 7 vs. 60 cells/high-power field (hpf) +/- 2 SEM, p < .001], followed by whole-grain sorghum dust (121 +/- 5 cells/hpf). Next, bovine bronchial epithelial cells (BBECs) were obtained from fresh lungs and grown to near confluence before challenge with a 10% solution of grain dust and grain plant extracts. The grain sorghum glume and whole-grain sorghum dusts caused release of the greatest amount of neutrophil chemotactic activity (NCA) from BBECs compared to the medium M199 negative control (141 +/- 6 and 153 +/- 7, respectively, vs. 64 cells/hpf +/- 3 SEM, p < .001). The ability to cause neutrophils to migrate by direct and indirect means did not correlate with levels in the grain dusts of endotoxin, which is known to cause release of NCA from bronchial epithelial cells. Therefore, this article describes additional mechanisms by which grain dusts can cause pulmonary inflammation and that are independent of endotoxin levels.

Neutrophilic respiratory tract inflammation and peripheral blood neutrophilia after grain sorghum dust extract challenge.

STUDY OBJECTIVE: To determine if inhalation of grain sorghum dust in the laboratory would cause neutrophilic upper and lower respiratory tract inflammation in human volunteers, as well as systemic signs of illness. DESIGN: Prospective. SETTING: University of Nebraska Medical Center. PARTICIPANTS: Thirty normal volunteers. INTERVENTIONS: Inhalation challenge with 20 mL of a nebulized solution of filter-sterilized grain sorghum dust extract (GSDE). One group received prednisone, 20 mg for 2 days, prior to the challenge. MEASUREMENTS AND RESULTS: Bronchoscopy with bronchoalveolar lavage (BAL) was performed 24 h after challenge, with samples collected as bronchial and alveolar fractions. Findings included visible signs of airways inflammation, quantified as the bronchitis index. The percentage of bronchial neutrophils was significantly increased in those challenged with GSDE vs the control solution, Hanks' balanced salt solution (40.3 +/- 4.5% vs 14.3 +/- 5.1%, p < or = .01). Similar findings were seen in the alveolar fraction. Pretreatment with corticosteroids did not prevent the rise in neutrophils recovered by BAL. Peripheral blood neutrophils were also increased in volunteers challenged with the grain dust extract. To explain the increase in peripheral blood neutrophil counts, the capacity of the peripheral blood neutrophils to migrate in chemotaxis experiments was examined. The results demonstrate an increase in peripheral blood neutrophils and an increase in chemotactic responsiveness. CONCLUSIONS: Inhalation challenge with a grain dust extract causes respiratory tract inflammation and a peripheral blood neutrophilia. One reason for this may be an increase in activated peripheral blood neutrophils.

Neutrophil chemotaxis to extracts of grain plant components.

Exposure to grain dust has been associated with a neutrophilic bronchitis. In vitro studies suggest several possible mechanisms for recruitment of neutrophils, including direct chemotaxis to aqueous grain dust extracts and release of chemotactic activity by bronchial epithelial cells in response to challenge with grain dust extracts.

The eye and liver disorders.

There are ocular changes associated with a wide spectrum of congenital, familial and acquired liver diseases and disorders. The early identification of ocular changes may aid diagnosis of the underlying liver condition. This is particularly important in conditions where there are effective treatments which can arrest hepatic damage. It is also of considerable value in patients who have untreatable disorders because identification of the correct diagnosis may offer prognostic information and spare the patient unnecessary invasive investigation. This article discusses the ocular findings in selected liver disease and reviews the current literature on the subject. The principles of investigation and diagnosis and treatment are described. Data on the incidence and prevalence of ocular involvement in liver conditions are included where such figures are available. The potential transmission of viral hepatitis following corneal grafting is discussed.

Eyelid leishmaniasis in a patient with neurogenic ptosis.

A patient with chronic progressive external ophthalmoplegia contracted cutaneous leishmaniasis of the upper eyelid. Infection of this site is rare because eyelid movements usually prevent the sandfly vector from biting the skin there. It is postulated that the relative immobility of the upper eyelid in this patient was a major predisposing factor for the infection.

Warning about bacterial contamination of therapeutic contact lenses.

Three of twenty-six soft therapeutic contact lenses were found to have bacterial contaminants in their original sealed manufacturers' containers. We wish to alert clinicians to this danger.

Infective conjunctivitis and corneal scarring in three brothers with sex linked hypogammaglobulinaemia (Bruton's disease).

The ocular findings in three brothers with Bruton's disease are reported. All three boys had purulent conjunctivitis, but the two older brothers also developed marked corneal scarring with visual impairment. Haemophilus influenzae was cultured from conjunctival swabs; it was resistant to neomycin but sensitive to chloramphenicol. Tear analysis showed that the three subjects had normal levels of lysozyme but no detectable IgA.