Proliferative activity in craniopharyngiomas: clinicopathological correlations in adults and children.

Background: Craniopharyngiomas are slow-growing, locally invasive intracranial tumors that can generate considerable morbidity, and recurrences are often difficult to manage. Because reliable morphologic criteria for accurately predicting the clinical outcome of these tumors are lacking, we evaluated the growth potential of craniopharyngiomas by measuring their proliferative activity based on MIB-1 immunostaining for the Ki-67 antigen, which is expressed during all phases of the cell cycle except G(0.)

Methods: Paraffin sections from 37 cases of craniopharyngiomas were immunostained with the monoclonal antibody MIB-1, and a labeling index was derived in each case from an the with the highest labeling.

Measurement of gamow-teller strength for 176Yb --> 176Lu and the efficiency of a solar neutrino detector.

We report a 0 degrees 176Yb(p,n)176Lu measurement at IUCF where we used 120 and 160 MeV protons and the energy dependence method to determine Gamow-Teller (GT) matrix elements relative to the model independent Fermi matrix element. The data show that there is an isolated concentration of GT strength in the low-lying 1(+) states making the proposed Low Energy Neutrino Spectroscopy detector (based on neutrino captures on 176Yb) sensitive to pp and 7Be neutrinos and a promising detector to resolve the solar neutrino problem.

Gamow-teller strengths of the inverse beta transition 176Yb-->176Lu for spectroscopy of proton-proton and other sub-MeV solar neutrinos.

Discrete Gamow-Teller (GT) transitions 176Yb-->176Lu at low excitation energies have been measured via the ( 3He,t) reaction at 450 MeV and at 0 degrees. For 176Yb, two low-lying states are observed, setting low thresholds Q(nu) = 301 and 445 keV for neutrino ( nu) capture. Capture rates estimated from the measured GT strengths, the simple two-state excitation structure, and the low Q(nu) in Yb-Lu indicate that Yb-based nu detectors are well suited for a direct measurement of the sub-MeV solar electron-neutrino ( nu(e)) spectrum including pp neutrinos.

Sensory evoked potentials in SIV-infected monkeys with rapidly and slowly progressing disease.

Human immunodeficiency virus (HIV-1) infects the central nervous system (CNS) early in the course of disease progression and leads to some form of neurological disease in 40-60% of cases. Both symptomatic and asymptomatic HIV-infected subjects also show abnormalities in evoked potentials. As part of an effort to further validate an animal model of the neurological disease associated with lentiviral infection, we recorded multimodal sensory evoked potentials (EPs) from nine rhesus macaques infected with passaged strains of SIVmac (R71/E17), prior to and at 1 month intervals following inoculation.

Rhinosporidiosis on HIV - a case report.

Rhinosporidiosis is a chronic disease that classically presents with the involvement of nose and nasopharynx. However, it can be present in various other sites including conjunctiva, vulva, vagina, larynx and scalp. We report a case with a Rhinosporidial mass in the nose extending to oropharynx and multiple cutaneous lesions of Rhinosporidiosis in a patient with HIV, This case is the first of its kind where HIV has been associated with Rhinosporidiosis.

Alpha-synuclein expression in central nervous system tumors showing neuronal or mixed neuronal/glial differentiation.

Alpha-synuclein (alpha-synuclein) is a member of a family of cytoplasmic proteins found predominantly and abundantly in the brain, and concentrated in pre-synaptic nerve terminals, near vesicles. We hypothesized that an antibody to alpha-synuclein could be a useful marker of neuronal differentiation in central nervous system (CNS) tumors. Twenty tumors known to have neuronal or mixed neuronal/glial differentiation ( 11 gangliogliomas, 2 anaplastic gangliogliomas, 5 gangliocytomas, and 2 ganglioneuroblastomas), 5 central neurocytomas, and 1 dysembryoplastic neuroepithelial tumor (DNET) were immunostained with a mouse monoclonal antibody raised against human alpha-synuclein.

Detection of the human immunodeficiency virus regulatory protein tat in CNS tissues.

Neuropathologically, human immunodeficiency virus (HIV) is associated with a range of inflammatory disorders, extensive cortical neuronal loss, and dendritic and synaptic damage. Although the mechanisms resulting in these abnormalities are still unclear, the neurotoxic effects are thought to be due in part to viral products including the tat gene product. We have previously shown that Tat when presented to neurons extracellularly interacts with neuronal cell membranes to cause neuronal excitation and toxicity in fmole amounts.

Low-level (PPB) determination of cisplatin in cleaning validation (rinse water) samples. II. A high-performance liquid chromatographic method.

A high-performance liquid chromatographic (HPLC) method is described for the determination of residual levels of cisplatin from extracts of surfaces with very low surface area; from extracts of surfaces of coupons made of Teflon (polytetrafluoroethylene, PTFE), stainless steel, and glass; and in aqueous solution collected after rinsing equipment and parts. Initially, the method was developed to determine cisplatin at concentrations ranging from 20 to 200 ng/ml by direct injection. Retaining the same method conditions, the scope of the method was expanded by the addition of a sample preconcentration step, allowing analyses at levels ranging from 0.

Low-level (PPB) determination of cisplatin in cleaning validation (rinse water) samples. I. An atomic absorption spectrophotometric method.

Suitable analytical methods are required for quantitative determination of trace levels of ingredients in samples obtained for purposes of cleaning validation. We describe below an atomic absorption method for the quantitation of cisplatin, an antineoplastic agent, in aqueous samples. Cisplatin was reacted with diethyldithiocarbamic acid (DDTC), sodium salt, to yield a platinum-DDTC (Pt-DDTC) complex.

Microglial activation and neurological symptoms in the SIV model of NeuroAIDS: association of MHC-II and MMP-9 expression with behavioral deficits and evoked potential changes.

HIV-1 causes cognitive and motor deficits and HIV encephalitis (HIVE) in a significant proportion of AIDS patients. Neurological impairment and HIVE are thought to result from release of cytokines and other harmful substances from infected, activated microglia. In this study, the quantitative relationship between microglial activation and neurological impairment was examined in the simian immunodeficiency model of HIVE.

Morphological correlates of neurological dysfunction in macaques infected with neurovirulent simian immunodeficiency virus.

The pattern of neurological disease caused by human immunodeficiency virus (HIV) infection of the central nervous system (CNS) was investigated using a macaque model of acquired immune defiency syndrome (AIDS). Seven of nine macaques inoculated with neurovirulent simian imunodeficiency virus (SIVmac ) developed AIDS within 3 months. Four of these had clinically obvious neurological disease and extensive conduction defects in the form of latency increases in evoked potential (EP) responses.

Motor skill impairment in SIV-infected rhesus macaques with rapidly and slowly progressing disease.

A number of studies have shown that simian immunodeficiency virus (SIV) infection in rhesus macaques parallels many aspects of HIV disease in humans. The purpose of this study was to further characterize the rhesus macaque infected with neurovirulent SIV as a model of neuroAIDS. Using a motor skill task, our objective was to detect SIV-related movement impairments in behaviorally trained macaques.

The fusion protein of peste des petits ruminants virus is a hemolysin.

The fusion glycoprotein (F protein) of paramyxoviruses plays a vital role in virus-induced cytopathology. To explore the role of the F protein in peste des petits ruminants virus (PPRV)-induced cytopathology, the F protein of PPRV was purified by immunoaffinity chromatography. The purified F protein, when incubated with chicken erythrocytes, caused lysis suggesting that PPRV F protein is a hemolysin.

Derivation and biological characterization of a molecular clone of SHIV(KU-2) that causes AIDS, neurological disease, and renal disease in rhesus macaques.

Previously, we described the derivation of a pathogenic strain of simian-human immunodeficiency virus (SHIV(KU-2)) consisting of the tat, rev, vpu, and env genes of HIV-1 (strain HXB2) in a genetic background of SIV(mac)239 that causes AIDS and productive infection of the CNS in rhesus macaques (Macca mulatta) (Raghavan et al., 1997, Brain Pathol. 7, 851-861).

Motor evoked potentials in a rhesus macaque model of neuro-AIDS.

Previous work using bone marrow passaged SIVmac239 (simian immunodeficiency virus) has shown that macrophage tropic strains of this virus enter the rhesus macaque brain early following inoculation (Sharma et al, 1992; Desrosiers et al, 1991; Zhu et al, 1995; and Narayan et al, 1997). As part of an effort to more fully characterize the extent of neurologic impairment associated with SIV infection of the brain, we used transcranial electrical stimulation of motor cortex and the spinal cord to evoke EMG potentials in two forelimb (EDC and APB) and two hindlimb (LG and AH) muscles. The latencies, magnitudes and thresholds of motor evoked potentials (MEPs) recorded from nine monkeys infected with neurovirulent SIVmac R71/17E were compared to pre-inoculation records from the same monkeys.

Splenic peliosis: a rare complication following liver transplantation.

In this article, we report a rare case of isolated splenic peliosis in an individual who had recently undergone liver transplantation. The disorder had remained clinically and radiologically undiagnosed until he suffered a traumatic rupture of the affected organ. The relevant literature on this topic is briefly reviewed.

Proteinmorphosis: a mechanical model for protein conformational changes.

Proteinmorphosis is a physically-based interactive modeling system for simulating large or small conformational changes of proteins and protein complexes. It takes advantage of the cross-linked one-dimensional nature of protein chains. The user can, based on her chemical knowledge, pull pairs of points (lying either on a single protein or on different molecules) together by specifying geometric distance constraints.

Protection of rabbits against lapinized rinderpest virus with purified envelope glycoproteins of peste-des-petits-ruminants and rinderpest viruses.

Haemagglutinin (HA) and fusion (F) proteins of peste-des-petits-ruminants virus (PPRV) and rinderpest virus (RPV) were purified by immunoaffinity chromatography. The purified proteins were characterized by polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate (SDS-PAGE). Rabbit hyperimmune sera were raised against the purified HA and F proteins and assayed by enzyme-linked immunosorbent assay (ELISA), haemagglutination-inhibition (HAI) and virus neutralization (VN) tests.

Simple and choice reaction time performance in SIV-infected rhesus macaques.

It is well established that HIV infection can lead to motor/cognitive disorders in humans. A number of studies have shown that simian immunodeficiency virus (SIV) infection in rhesus macaques parallels many aspects of HIV disease in humans. The purpose of this study was to define further the SIV-infected rhesus macaque as a model of neuro-AIDS.

Auditory brainstem responses in a Rhesus Macaque model of neuro-AIDS.

Nine rhesus macaques (Macaca mulatta) were inoculated with a combination of two passaged strains of SIVmac (R71 and 17E), both of which are known to be neurovirulent. Auditory brainstem responses (ABRs) were recorded at regular intervals from these animals both before and after inoculation. Increases in ABR peak and interpeak latency were observed corresponding to progression of SIV disease.

Neurovirulent simian immunodeficiency virus induces calbindin-D-28K in astrocytes.

Astrocyte activation has been postulated to be a major contributor to functional changes in the brain of AIDS patients. We assessed astrocyte activation in the simian immunodeficiency virus (SIV) model. Four groups of macaque brains were examined: uninoculated controls, animals inoculated with virus that did not cause disease, animals inoculated with virus that caused AIDS but did not cause encephalitis, and animals with SIV encephalitis.

A vascular catheterization simulator for training and treatment planning.

We have developed a working prototype of an augmented reality based vascular catheterization simulator. The simulator is called daVinci, and provides the interventional radiologists with a "hands on, user friendly, image based environment to augment training, enhance pretreatment planning and design interventional products and devices. daVinci is based on computational modeling of human anatomical images and provides the user with capabilities for realtime simulated navigation of catheters in both 2-D and 3-D modeled vessels.

Nucleotide substitutions in the long terminal repeat are not required for development of neurovirulence by simian immunodeficiency virus strain mac.

The question of whether consensus nucleotide substitutions in the long terminal repeat (LTR) region of simian immunodeficiency virus strain mac (SIVmac) are important for neurovirulence was investigated in this report. Brains and lymph nodes from two macaques that developed AIDS and encephalitis following inoculation with two strains of neurovirulent SIVmac, and from one animal with AIDS but no neurological disease after inoculation with non-neurovirulent SIVmac239 were used. The 5' LTR regions from neurovirulent SIVmacR71/17E and SIVmac7F-Lu were amplified, cloned and sequenced and these sequences were compared to the LTRs amplified from three regions of the respective encephalitic brains and lymph nodes from macaques inoculated with each virus.