bluuebunny/crossref_metadata_2025_split huggingface dataset:
Repeated immunolesions display diminished stress response signal
Authors: Gu Zezong , Yu Juan , Werrbach‐Perez Karin , Perez‐Polo J. Regino 
Published: July 2002

AbstractCholinergic basal forebrain neurons (CBFNs) retrogradely transport neurotrophins released in the hippocampus and cortex as part of a general response to injury in a process that is impaired in the aged rodent and can be spared by the exogenous addition of pharmacological doses of nerve growth factor (NGF). This observation suggests that components of stress response signal transduction pathways in the aged CNS can be exogenously activated. The extent and mechanism of the endogenous stimulation of NGF in response to injury can be mimicked via treatment with 192 IgG‐saporin of rat CNS, an immunolesion model. Here we report on the use of a conditioning lesion paradigm to determine if repeated partial immunolesions have a conditioning effect on the immunolesion‐induced increases in NGF protein or decreases in choline acetyltransferase (ChAT) and acetylcholinesterase (AChE) activity.We report that chronic repeated immunolesions, as used here, were not as effective as a one time equivalent immunolesion in terms of induced NGF protein increases or decreasing ChAT and AChE activity in the hippocampus and cortex. Thus, chronic lesions resulting in cholinergic impairment typical of the aged CNS may differ from acute toxic models as a result of desensitization due to a conditioning effect of chronic subthreshold lesioning events in the CNS.
Factors Important in the Extraction, Stability and in Vitro Assembly of the Hepatitis B Surface Antigen Derived from Recombinant Plant Systems
Authors: Smith Mark L. , Keegan Mark E. , Mason Hugh S. , Shuler Michael L. 
Published: July 2002

AbstractThe expression of vaccine antigens in edible plant material together with their delivery by the oral route constitutes a powerful paradigm, with the potential to dramatically reduce the cost of vaccine production and administration, in addition to improving distribution and patient compliance. These products will be subject to many of the same regulations applied to current injectable vaccines, so reliable methods to quantify antigen and ensure stability in crude plant extracts are required. As a model system the hepatitis B surface antigen (HBsAg) was expressed in soybean and tobacco cell cultures. This complex antigen consists of membrane‐associated small surface antigen proteins (p24s), disulfide cross‐linked to yield dimers and higher multimers. Although the total p24s extracted from plant cells was relatively unaffected by detergent concentration, the quantification of antigenically reactive product depended strongly on the ratio of detergent to cell concentration. Furthermore, 1–20% w/v sodium ascorbate improved the measured levels of monoclonal‐reactive antigen 4‐ to 12‐fold. Detergent also influenced antigen stability in cell lysates stored at 4 °C; under optimum conditions stability was maintained for at least 1 month, whereas excess detergent rendered the antigen susceptible to proteolytic degradation. This proteolysis could be counteracted by the addition of skim milk or its protein component, which stabilized antigenically reactive p24s for up to 2 months. The immunologically relevant epitopes of HBsAg are critically dependent on disulfide bonding. By altering the sodium ascorbate concentration or buffer pH the proportion of HBsAg displaying the monoclonal reactive epitopes was increased between 8‐ and 20‐fold. In addition, under certain conditions the dimerized p24s could be converted to oligomeric aggregates, resembling the form of the serum‐derived antigen. These simple in vitro manipulations, compatible with the goal of a minimally processed oral vaccine, may prove valuable in increasing the immunogenicity of the plant‐derived antigen.
Modeling Heat Transfer during High‐Pressure Freezing and Thawing
Authors: Denys Siegfried , Van Loey Ann M. , Hendrickx Marc E. , Tobback Paul P. 
Published: July 2002

AbstractAn existing theoretical model for predicting product temperature profiles during freezing and thawing processes was extended for simulating high‐pressure freezing and thawing processes. To take into account the influence of elevated pressure a simplifying approach is suggested, consisting of shifting the known thermophysical properties at atmospheric pressure on the temperature scale depending on the prevalent pressure. The applicability of the method to simulate high‐pressure freezing and thawing profiles was tested for a food simulant (Tylose) . Good agreement between experimental and predicted temperature profiles was observed for both high pressure freezing and thawing.
Sonographic diagnosis of diastematomyelia in utero: A case report and literature review
Authors: Dabra A , Gupta R , Sidhu R , Kochhar S , Kaur L , Singh J 
Published: July 2002

SUMMARYFetal diastematomyelia is a rare form of spinal dysraphism that is characterized by a complete or incomplete division of the spinal cord by an osseous or fibrocartilaginous septum. A case of diastematomyelia, which was detected on the routine third trimester detailed ultrasound scan, is presented. The diagnosis was based on the detection of an echogenic focus in the posterior aspect of the spine in association with widening of the interpedicular vertebral space. The case illustrates that diastematomyelia can occur in the absence of overt spina bifida and that prenatal detection will allow timely postnatal investigation and treatment. Prenatal literature is further reviewed to assess the clinical significance of this finding.
Local immune response after intravesical interferon gamma in superficial bladder cancer
Authors: Stavropoulos  , Ioachim  , Pavlidis  , Pappa  , Kalomiris  , Agnantis  
Published: July 2002

Objective To investigate the lymphocyte subpopulations (T4, T8 and macrophages) and major histocompatibility (MHC) II antigens in patients with superficial bladder cancer before and after intravesical instillations of recombinant interferon‐γ (IFN‐γ).Patients and methods Four intravesical weekly instillations of either 1.3 mg (20 patients, group A) or 0.7 mg (11 patients, group B) IFN‐γ were administered in 31 evaluable patients (28 men and three women, mean age 68.5 years). The CD4+, CD8+, CD68+and HLA‐DR antigens were detected immunohistochemically in tumours and a marker tumour before and after intravesical instillations.Results The median number of T4 lymphocytes increased from 15 per high‐power field (HPF) to 27.5 in group A (P=0.0029) and to 45 in group B (P=0.0117). Macrophages increased from 6 cells/HPF to 15 cells/HPF in group A (P=0.0029) and from 2 to 8.75 cells/HPF in group B (P=0.0117). The T8 lymphocyte subpopulation decreased from 4 to 3 cells/HPF (P=0.0231) in group A and from 5 to 2 cells/HPF (P=0.0759) in group B. The median percentage of HLA‐DR antigens increased from 1.5% to 18% in general, (P<0.001), from 2.5% to 15% in group A (P=0.0064) and from 0% to 20% in group B (P=0.0077). The induction of HLA‐DR antigens was statistically significant in those receiving the lower dose (from 0% before instillation to 20% afterward, P=0.0277), while it was not with the higher dose (from 0% to 5%, P=0.068). Irrespective of the dose of IFN used, T4 lymphocytes and macrophages increased significantly after treatment in patients in whom the tumour HLA‐DR antigens were either upregulated or remained stable. The median net increase in T4 cells was 17.5 and 30 cells/HPF for groups A and B, respectively (P=0.0429).Conclusion T4 lymphocytes, macrophages and HLA‐DR antigens increased after intravesical IFN‐γ in patients with superficial bladder cancer, but T8 lymphocytes decreased. Irrespective of the drug dose used, patients with either upregulated or stable HLA‐DR antigens after treatment showed the same pattern of changes in the lymphocyte subpopulations. The two doses generally had the same effect on the immunological variables assessed but the lower dose was more effective in inducing HLA‐DR antigens and in increasing the number of T4 lymphocytes in the tumours.
Halogenation of diamond (100) and (111) surfaces by atomic beams
Authors: Freedman Andrew 
Published: July 2002

Diamond (100) and (111) surfaces have been exposed to beams of atomic and molecular fluorine and chlorine in an ultrahigh-vacuum environment. X-ray photoelectron spectroscopy, low-energy electron diffraction, and thermal desorption techniques have been used to elucidate the chemistry involved. F atoms add to both the diamond (100)-(1×1) and (111)-(2×1) surfaces to form a carbon-monofluoride species which reaches a saturation level of approximately three-quarters of a monolayer at 300 K. In other aspects of their behavior, the diamond surfaces differ. On the (111) surface, the rate of fluorine atom uptake is, to first order, proportional to the open site concentration. Adsorption produces a dimming of the half-order electron-diffraction spots, suggesting the breaking of surface π-bonded chains to form regions of the bulk 1×1 reconstruction. The (100) surface uptake rate, though, is second order with respect to open site concentration and no electron-diffraction pattern is observed. This difference in behavior between the two surfaces is ascribed to the difference in bonding geometry, leading to severe steric hindrance to ordered adsorption on the (100) surface. The thermal desorption data show fluorine desorption over a wide temperature range (500–1200 K) on both surfaces indicating binding sites with a range of energies.
Limited mass spectrometric data indicates that atomic fluorine is the major desorption product. These results imply that atomic fluorine will act in a fashion similar to hydrogen atoms in that they will break surface dimer bonds, desorb from the surface at an appropriate temperature without etching diamond, and abstract any surface hydrogen in deposition systems utilizing halocarbon species. The much larger chlorine atoms weakly chemisorb on the diamond (100) surface, producing a saturation coverage of less than half a monolayer at 300 K. The adlayer neither shows a distinct C-Cl peak in the x-ray photoelectron spectra nor exhibits any electron-diffraction pattern. In addition, thermal desorption studies indicate that the concentration of chlorine atoms monotonically decreases to virtually zero as the substrate is heated from 223 to 423 K. A small residual chlorine concentration remains up to 600 K, presumably due to binding at defect sites. This behavior implies that atomic chlorine will exhibit a less significant role in the surface chemistry of diamond deposition systems.
Magnetic and Mössbauer studies of hot-pressed MnZnNi ferrites (abstract)
Authors: Babbar V. K. , Puri R. K. 
Published: July 2002

Hot-pressed MnZn ferrites are extensively used for magnetic recording applications. The present work investigates the magnetic properties of MnZnNi ferrites by using the Mössbauer spectroscopy and taking bulk magnetic measurements. Ferrites of the composition Mn0.6Zn0.4−xNixFe2O4 (0≤x≤0.4) have been prepared by uniaxial hot pressing technique. The final sintering was performed at 1250 °C for 3 h under a pressure of 35 MPa. The samples exhibit high density (porosity &lt;0.1%) nearly uniform grain size (average grain size=0.01 mm approx.), and large Vickers’ hardness (650 approx.). The variations of initial permeability, saturation magnetization, Curie temperature, and coercive field are studied by changing Ni2+ content. The initial permeability increases slightly for x≤0.05, attains a maximum value of 5660, and decreases continuously for x≳0.05. The saturation magnetization increases for x≤0.25 and decreases for x≳0.25. The maximum saturation magnetization obtained for x=0.25 is 4825 G. The Curie temperature increases markedly from 431 to 682 K with increasing Ni2+ content. The coercive field decreases slightly for x≤0.05, becomes as low as 0.09 Oe, and increases almost linearly thereafter.
The results are explained on the basis of sublattice magnetizations, stren of AB exchange interactions and change in magnetocrystalline anisotropy constant. The Mössbauer studies reveal the well-defined hyperfine spectra for Ni2+-substituted samples. The isomer shift remains almost unaffected by Ni2+ substitution, while the quadrupole splitting is observed to be negligible for all the samples. The hyperfine field decreases continuously as x increases from 0 to 0.4. The occupancy ratio of Fe3+ ions on octahedral to tetrahedral sites yields a cation distribution which conforms with the bulk magnetic measurements. The MnZnNi ferrite compositions with x ranging from 0.05 to 0.10 exhibit properties which make them suitable materials for recording head applications.
Book Reviews
Authors: MICHAEL MICHAEL 
Published: July 2002

Book reviewed in this article: Growing Up Tobacco Free: Preventing Nicotine Addiction in Children and Youths BARBARA S. LYNCH & RICHARD J. BONNIE (Eds) Nicotine Addiction: Principles and Management C. TRACY ORLEANS & JOHN SLADE (Eds) Alcohol Treatment: A Study of Therapists and Clients J. KEENE Drinking Careers: A Twenty‐Five‐Year Study of Three Navajo Populations STEPHEN J. KUNITZ & JERROLD E. LEVY Drug and Alcohol Abuse MARC A. SCHUCKIT Preventing AIDS: Theories and Methods of Behavioral Interventions RALPH J. DICLEMENTE & JOHN L. PETERSON
Anxiety and pupil reactivity in cocaine dependent subjects endorsing cocaine‐induced paranoia: preliminary report
Authors: ROSSE RICHARD B. , ALIM TANYA N. , JOHRI SURENDRA K. , HESS ANEMARIE L. , DEUTSCH STEPHEN I. 
Published: July 2002

AbstractThere has been the clinical impression that people with higher levels of anxiety and central arousal are more prone to develop cocaine‐induced paranoia (CIP), but this notion has not been formally studied. In the current study, we examined the differences between 28 CIP‐endorsing and 16 CIP‐denying chronic cocaine users in their levels of state and trait anxiety as measured by the Spielberger State‐Tail Anxiety Inventory. We also studied levels of central arousal and reactivity using pupil size measures both during exposure to neutral, abstract, non‐drug cues, and after exposure to a cocaine cue. Levels of trait (but not state) anxiety were significantly higher in the CIP group than in the non‐CIP group. Moreover, while there were no significant pupil size differences or changes between the two groups while viewing neutral, abstract video images, the CIP group had significantly greater pupillary dilation in response to a video image of crack cocaine than did the non‐CIP group. These significant differences remained even after covarying for anxiety scores. The study findings seem relevant to studies of autonomic reactivity in response to drug cues in cocaine‐dependent patients; such studies might remain attentive to potential cue reactivity differences between patients endorsing and those denying CIP. Finally, this is the first study showing higher trait anxiety in patients with CIP.
Encounters with aggressive conspecifics enhance the locomotor‐activating effects of cocaine in the rat
Authors: MARROW LYNNE P. , OVERTON PAUL G. , BRAIN PAUL F. , CLARK DAVID 
Published: July 2002

AbstractEvidence suggests that stress enhances the behavioural actions of cocaine in the rat. Paradoxically, however, encounters with aggressive conspecifics lead to a pattern of cocaine self‐administration indicative of a reduced functional impact of the drug. Hence, we examined the effects of aggressive encounters on another behavioural measure‐locomotor activity. Encounters between Lister Hooded rats and rats of the aggressive Tryon Maze Dull strain significantly enhanced the locomotor‐activating effects of cocaine (20 mg/kg) in the Lister Hooded rats. The results suggest that the discrepant findings derived from self‐administration studies are a property of the paradigm rather than a property of the stressor.
Electrocardiographic abnormalities during recovery from ultra‐short opiate detoxification
Authors: ALLHOFF THOMAS , RENZING‐KÖHLER KATRIN , KIENBAUM PETER , SACK STEFAN , SCHERBAUM NORBERT 
Published: July 2002

AbstractThe aim of this study was to detect electrocardiographic abnormalities during recovery from ultra‐short opiate detoxification, using a retrospective study design conducted at a university hospital. Twenty‐two consecutive patients (mean±SD, age 30.0±6.3 years) receiving daily oral methadone underwent ultrashort opiate detoxification under general anaesthesia. In the post‐anaesthetic stages they received oral clonidine and naltrexone, and in some cases trimipramine was dispensed. Heart rate, rate‐corrected QT interval (msec) and repolarization abnormalities of 12‐lead electrocardiographic recordings before and after detoxification were examined. The serum electrolyte concentrations (mmol/l) including Na+, K+ and Ca2+ were assessed. Eightyone ECGs were evaluated in total. Compared to the initial values, heart rate was significantly lowered in the first two tracings after detoxification (median values 60.0/min. vs. 52,5/min; p=0.0006). The lowest heart rate measured after detoxification was 44/min. The cQT interval was significantly lengthened (median value 420 msec vs. 453 msec after detoxification). In 16 tracings (20%) taken from 10 patients (45%) cQT rose above 460 msec and in two tracings (2%) it topped 500 msec. Modest hypokalaemia (2.9–3.5 mmol/l) was linked to cQT prolongation (460 msec) in 10 ECG tracings. Spearman's correlation coefficient indicated that prolonged cQT intervals correlated with decreased potassium values. Twelve tracings (15%) taken from 10 patients (45%) after detoxification showed T‐wave inversion and in two cases sinus rhythm was turned into a rhythm arising from the atrioventricular node. Serum potassium was significantly lowered (median values 4.3 v.s 3.8 mmol/l, p=0.0001). The Ca2+ concentration fell significantly (2.4 vs. 2.2 mmol/l, p=0.0001) but not below the normal range. It was concluded that ultra‐short opiate detoxification carries the risk of QTprolongation and bradycardia. These side effects are reversible and can be explained by hypokalaemia and clonidine medication, the effects of which might reinforce each other. To avoid arrhythmic complications, ECG tracings should be carried out regularly during recovery, i.e. at least daily, for a span of 3 days after discharge from the intensive care unit.
Regulation of DNA Replication During the Cell Cycle: Roles of Cdc7 Kinase and Coupling of Replication, Recombination, and Repair in Response to Replication Fork Arrest
Authors: Masai Hisao , Arai Ken‐ichi 
Published: July 2002

AbstractDNA replication is central to cell growth, development, and generation of tissues and organs. Recent advances in understanding replication machinery have revealed striking conservation of components involved in the processes of DNA replication, from yeasts to human. The conservation extends even to bacteria for some basic components of replication apparatus. Eukaryotic DNA replication is regulated at various stages to ensure strict regulation during cell cycle. We have identified a novel mammalian kinase, Cdc7‐ASK (Activator of S phase Kinase), that plays a key role at the entry into S phase as a molecular switch for DNA replication. This kinase is specifically activated during S phase and triggers the firing of DNA replication by phosphorylating an essential DNA helicase component of the replication complex. Environmental stresses such as DNA damages or depletion of essential nutrients for DNA synthesis lead to unscheduled arrest of DNA replication forks. In bacteria, this leads to induction of altered modes of DNA replication, which may repair DNA damages, facilitate reassembly of replication machinery at the stalled replication fork, or do both. In eukaryotes, blocking replication forks usually induces both checkpoint responses, which prevent premature progression of cell cycle events before precise completion of the preceding cell cycle stage, and the recombinational repair system for the lesions. Possible common bases in recognition of stalled replication forks in bacteria and eukaryotes will be discussed. Furthermore, we will discuss the potential of replication and checkpoint proteins as targets of anticancer agents as well as possible novel technology for stem cell amplification through manipulation of DNA replication.
Association of State-Level Firearm-Related Deaths With Firearm Laws in Neighboring States
Authors: Liu Ye , Siegel Michael , Sen Bisakha 
Published: November 2022

ImportanceFirearms are easily transported over state borders; hence permissive firearm laws in one state may have an interstate association with firearm-related deaths in nearby states.ObjectivesTo examine whether certain firearm laws have an interstate association with firearm-related deaths in nearby states.Design, Setting, and ParticipantsThis cross-sectional observational study used data on state firearm-related deaths in the 48 contiguous states of the US between January 1, 2000, and December 31, 2019. A spatial autoregressive model with fixed effects for state and year was used to evaluate within-state, interstate, and overall associations between firearm laws and firearm-related deaths. Analyses were performed during January 2022.ExposuresThe following 9 types of laws were evaluated: universal background checks for all firearms purchase, background checks for handgun sales at gun shows, license requirement to purchase all firearms, state dealer license requirement for handgun sales, requirement of retaining records of handgun sales, ban on purchasing a handgun on behalf of another, prohibition of firearm possession by persons who committed violent misdemeanors, required relinquishment of firearms for persons becoming prohibited from possessing them, and discretion in granting a concealed carry permit.Main Outcomes and MeasuresState-level total firearm-related death rates, suicide rates, and homicide rates.ResultsIn sum, the study period included 662 883 firearm-related deaths of all intents. License requirement for firearm purchase had a within-state association (effect size, −1.79 [95% CI, −2.73 to −0.84]), interstate association (effect size, −10.60 [95% CI, −17.63 to −3.56]), and overall association (effect size, −12.38 [95% CI, −19.93 to −4.83]) per 100 000 population decrease in total firearm-related deaths. This law also had within-state association (effect size, −1.26 [95% CI, −1.72 to −0.80]), interstate association (effect size, −9.01 [95% CI, −15.00 to −3.02]), and overall association (effect size, −10.27 [95% CI, −16.53 to −4.01]) per 100 000 population decrease in firearm-related homicide.Conclusions and RelevanceThe findings of this pooled cross-sectional analysis suggest that certain firearm laws in one state were associated with other states’ firearm-related deaths. Synergic legislative action in adjacent states, federal firearm legislation, and measures that reduce migration of firearms across state borders should be part of the overarching strategy to prevent firearm-related deaths.