bluuebunny/crossref_metadata_2025 huggingface dataset:
Using autoregressive integrated moving average (ARIMA) models to predict and monitor the number of beds occupied during a SARS outbreak in a tertiary hospital in Singapore
Authors: Earnest Arul , Chen Mark I , Ng Donald , Sin Leo Yee
Published: May 2005

Background

The main objective of this study is to apply autoregressive integrated moving average (ARIMA) models to make real-time predictions on the number of beds occupied in Tan Tock Seng Hospital, during the recent SARS outbreak.

Methods

This is a retrospective study design. Hospital admission and occupancy data for isolation beds was collected from Tan Tock Seng hospital for the period 14th March 2003 to 31st May 2003. The main outcome measure was daily number of isolation beds occupied by SARS patients. Among the covariates considered were daily number of people screened, daily number of people admitted (including observation, suspect and probable cases) and days from the most recent significant event discovery. We utilized the following strategy for the analysis. Firstly, we split the outbreak data into two. Data from 14th March to 21st April 2003 was used for model development. We used structural ARIMA models in an attempt to model the number of beds occupied. Estimation is via the maximum likelihood method using the Kalman filter. For the ARIMA model parameters, we considered the simplest parsimonious lowest order model.

Results

We found that the ARIMA (1,0,3) model was able to describe and predict the number of beds occupied during the SARS outbreak well. The mean absolute percentage error (MAPE) for the training set and validation set were 5.7% and 8.6% respectively, which we found was reasonable for use in the hospital setting. Furthermore, the model also provided three-day forecasts of the number of beds required. Total number of admissions and probable cases admitted on the previous day were also found to be independent prognostic factors of bed occupancy.

Conclusion

ARIMA models provide useful tools for administrators and clinicians in planning for real-time bed capacity during an outbreak of an infectious disease such as SARS. The model could well be used in planning for bed-capacity during outbreaks of other infectious diseases as well.
Plasma retinol, carotene and vitamin E concentrations and lung function in a crocidolite-exposed cohort from Wittenoom, Western Australia: a cohort study
Authors: Alfonso Helman S , Fritschi Lin , de Klerk Nicholas H , Ambrosini Gina , Beilby John , Olsen Nola , Musk A William
Published: May 2005

Background

Increased rates of death from asbestos related diseases have been reported for people previously employed in the mining and milling operations at Wittenoom (Western Australia), and people who lived in the nearby town, where they were environmentally exposed to crocidolite.

Methods

Annual measurements of forced expiratory volume in 1 second (FEV1) and forced vital capacity (FVC) and plasma concentrations of retinol, carotene and vitamin E have been made since 1992. Mixed effects models were used to examine the associations between lung function and the plasma vitamin levels of retinol, carotene and vitamin E.

Results

After adjusting for potential confounders, higher plasma retinol and carotene concentrations were significantly associated with higher levels of lung function at entry into the study, while vitamin E concentrations were associated with lower entry lung function. Retinol was associated with a less steep decline of lung function over time, while carotene concentrations were associated with an increased decline of lung function over time and vitamin E levels were not associated with changes of lung function over time.

Conclusion

These results support a beneficial relationship between plasma concentrations of retinol on the levels and rates of change of lung function, while showing no such consistent beneficial effect for plasma levels of beta-carotene or vitamin E.
Estimating summary measures of health: a structured workbook approach
Authors: Flanagan William , Boswell-Purdy Jane , Le Petit Christel , Berthelot Jean-Marie
Published: May 2005

Background

Summary measures of health that combine mortality and morbidity into a single indicator are being estimated in the Canadian context for approximately 200 diseases and conditions. To manage the large amount of data and calculations for this many diseases, we have developed a structured workbook system with easy to use tools. We expect this system will be attractive to researchers from other countries or regions of Canada who are interested in estimating the health-adjusted life years (HALYs) lost to premature mortality and year-equivalents lost to reduced functioning, as well as population attributable fractions (PAFs) associated with risk factors. This paper describes the workbook system using cancers as an example, and includes the entire system as a free, downloadable package.

Methods

The workbook system was developed in Excel and runs on a personal computer. It is a database system that stores data on population structure, mortality, incidence, distributions of cases entering a multitude of health states, durations of time spent in health states, preference scores that weight for severity, life table estimates of life expectancies, and risk factor prevalence and relative risks. The tools are Excel files with embedded macro programs. The main tool generates workbooks that estimate HALY, one per disease, by copying data from the database into a pre-defined template. Other tools summarize the HALY results across diseases for easy analysis.

Results

The downloadable zip file contains the database files initialized with Canadian data for cancers, the tools, templates and workbooks that estimate PAF and a user guide. The workbooks that estimate HALY are generated from the system at a rate of approximately one minute per disease. The resulting workbooks are self-contained and can be used directly to explore the details of a particular disease. Results can be discounted at different rates through simple parameter modification.

Conclusion

The structured workbook approach offers researchers an efficient, easy to use, and easy to understand set of tools for estimating HALY and PAF summary measures for their country or region of interest.
Simultaneous assessment of cytotoxic T lymphocyte responses against multiple viral infections by combined usage of optimal epitope matrices, anti- CD3 mAb T-cell expansion and "RecycleSpot"
Authors: Bihl Florian K , Loggi Elisabetta , Chisholm John V , Hewitt Hannah S , Henry Leah M , Linde Caitlyn , Suscovich Todd J , Wong Johnson T , Frahm Nicole , Andreone Pietro , Brander Christian
Published: May 2005

The assessment of cellular anti-viral immunity is often hampered by the limited availability of adequate samples, especially when attempting simultaneous, high-resolution determination of T cell responses against multiple viral infections. Thus, the development of assay systems, which optimize cell usage, while still allowing for the detailed determination of breadth and magnitude of virus-specific cytotoxic T lymphocyte (CTL) responses, is urgently needed. This study provides an up-to-date listing of currently known, well-defined viral CTL epitopes for HIV, EBV, CMV, HCV and HBV and describes an approach that overcomes some of the above limitations through the use of peptide matrices of optimally defined viral CTL epitopes in combination with anti-CD3 in vitro T cell expansion and re-use of cells from negative ELISpot wells. The data show that, when compared to direct ex vivo cell preparations, antigen-unspecific in vitro T cell expansion maintains the breadth of detectable T cell responses and demonstrates that harvesting cells from negative ELISpot wells for re-use in subsequent ELISpot assays (RecycleSpot), further maximized the use of available cells. Furthermore when combining T cell expansion and RecycleSpot with the use of rationally designed peptide matrices, antiviral immunity against more than 400 different CTL epitopes from five different viruses can be reproducibly assessed from samples of less than 10 milliliters of blood without compromising information on the breadth and magnitude of these responses. Together, these data support an approach that facilitates the assessment of cellular immunity against multiple viral co-infections in settings where sample availability is severely limited.
The World Summit on Sustainable Development: reaffirming the centrality of health
Authors: von Schirnding Yasmin
Published: May 2005

The World Summit on Sustainable Development (WSSD) was held in Johannesburg in 2002 to review progress since the Rio conference in 1992, and to agree a new global deal on sustainable development. Unlike its predecessor, it was primarily concerned with implementation rather than with new treaties and targets, although a number of new targets were agreed, for example one on sanitation. Failure to agree a target on renewable energy was regarded as a major disappointment of the conference. While relatively modest in its achievements, and with difficulties in achieving consensus in key areas such as energy, trade, finance and globalisation, WSSD nevertheless succeeded in placing sustainable development back on the political agenda, giving new impetus, in particular to the environment and development needs of Africa, with a strong focus on local issues like household energy, water and sanitation. Health was singled out as one of five priority areas, along with water, energy, agriculture and biodiversity, and was devoted a separate chapter in the resulting Plan of Implementation, which highlighted a range of environmental health issues as well as issues relating to health services, communicable and non-communicable diseases. A number of new partnerships were formed at WSSD, including the Healthy Environments for Children Alliance (HECA) launched by WHO, which will form an important platform for implementation. The Commission on Sustainable Development has been designated main responsibility for monitoring and follow up, with its programme of work reorganised to focus on thematic clusters of issues. From the perspective of health, WSSD must be seen as a reaffirmation of the central place of health on the sustainable development agenda, and in the broader context of a process which began in Rio and was given added impetus with the Monterrey Financing for Development conference and the World Trade Organisation meeting held in Doha. Translating policies into action at all levels- global to local – remains the single biggest challenge in the years that lie ahead.
Low-Dose Warfarin for Prevention of Symptomatic Thromboembolism after Orthopedic Surgery
Authors: Enyart Jeremy J , Jones Ronald J
Published: May 2005

BACKGROUND:

Warfarin dosing with a target international normalized ratio (INR) range of 1.5–2.5 has not been reported as adequate for venous thromboembolism (VTE) prophylaxis after total knee (TKR) and total hip replacement (THR) surgery. OBJECTIVE: To evaluate the rate of symptomatic VTE after TKR and THR surgery using a low-dose (INR 1.5–2.5) warfarin protocol started the evening before surgery compared with a literature cohort treated with enoxaparin.

METHODS:

TKR/THR patients treated with a 21-day low-dose warfarin protocol were followed via a consecutive observational design. Main outcome measures were symptomatic VTE and pulmonary embolism (PE), with major bleeds and death as secondary outcomes. Low-dose warfarin was compared with a literature cohort of patients treated with enoxaparin who received enoxaparin for a similar length of time and was evaluated for the same outcomes. Cohort event rates were derived as a weighted average using the DerSimonian model.

RESULTS:

VTE, PE, bleeds, and deaths in the low-dose warfarin group were 8 (1.04%), 4 (0.52%), 8 (1.04%), and 4 (0.52%), respectively. The cohort weighted average values were 35 (1.33%), 19 (0.72%), 65 (2.46%), and 18 (0.67%), respectively. Odds ratios for low-dose warfarin for VTE, PE, and VTE plus PE were 0.778 (95% CI 0.36 to 1.68), 0.717 (0.24 to 2.11), and 0.754 (0.41 to 1.42), respectively, all nonsignificant. Odds ratios for bleeds and death were 0.420 (0.20 to 0.87; p = 0.02) and 0.756 (0.26 to 2.24; NS), respectively.

CONCLUSIONS:

For this evaluation, low-dose warfarin was comparable to the enoxaparin cohort for development of VTE, PE, and VTE+PE. Incidences of bleeds in the enoxaparin cohort were significantly higher than in patients receiving low-dose warfarin.
Transporters and Their Impact on Drug Disposition
Authors: Beringer Paul M , Slaughter Richard L
Published: May 2005

OBJECTIVE:

To review the recent advances in knowledge about human transporters and their effect on drug disposition.

DATA SOURCES:

A MEDLINE search (1996–March 2005) was performed to identify pertinent literature on human transporters and their impact on drug disposition. Additional articles were identified from a manual search of the references of retrieved articles.

STUDY SELECTION AND DATA EXTRACTION:

Based on the identified studies, data were extracted on the impact of transporters on drug absorption, distribution, and elimination.

DATA SYNTHESIS:

The pharmacokinetic disposition of drugs is known to be influenced by metabolic enzymes, kidney function, and transporters. Recent research on human transporters has greatly advanced our understanding of their diversity and importance in drug disposition. In particular, members of the multidrug resistance family of transporters (MDR, MRP) are present in organs and tissues throughout the body and are known to significantly affect the absorption, distribution, and elimination of commonly prescribed drugs. A growing number of studies now demonstrate that alterations in transporter function as a result of drug interactions or genetic polymorphisms may explain a significant portion of the variability in treatment response for certain drugs.

CONCLUSIONS:

Human transporters contribute significantly to the pharmacokinetic disposition of drugs. Knowledge of substrates, inducers, and inhibitors of these transporters is necessary to ensure optimal patient outcomes.
Pedunculopontine Tegmental Nucleus Controls Conditioned Responses of Midbrain Dopamine Neurons in Behaving Rats
Authors: Pan Wei-Xing , Hyland Brian I.
Published: May 2005

Midbrain dopamine (DA) neurons respond to sensory cues that predict reward. We tested the hypothesis that projections from the pedunculopontine tegmental nucleus (PPTg) are involved in driving this DA cell activity. First, the activity of PPTg and DA neurons was compared in a cued-reward associative learning paradigm. The majority of PPTg neurons showed phasic responses to the onset of sensory cues, at significantly shorter latency than DA cells, consistent with a PPTg-to-DA transmission of information. However, unlike DA cells, PPTg responses were almost entirely independent of whether signals were associated with rewards. Second, DA neuron responses to the cues were recorded in free-moving rats during reversible inactivation of the PPTg by microinfusion of local anesthetic. The results showed clear suppression of conditioned sensory responses of DA neurons after PPTg inactivation that was not seen after saline infusion or in non-DA cells. We propose that the PPTg relays information about the precise timing of attended sensory events, which is integrated with information about reward context by DA neurons.
Truncated Prion Protein and Doppel Are Myelinotoxic in the Absence of Oligodendrocytic PrPC
Authors: Radovanovic Ivan , Braun Nathalie , Giger Olivier T. , Mertz Kirsten , Miele Gino , Prinz Marco , Navarro Beatriz , Aguzzi Adriano
Published: May 2005

The cellular prion protein PrPCconfers susceptibility to transmissible spongiform encephalopathies, yet its normal function is unknown. Although PrPC-deficient mice develop and live normally, expression of amino proximally truncated PrPC(ΔPrP) or of its structural homolog Doppel (Dpl) causes cerebellar degeneration that is prevented by coexpression of full-length PrPC. We now report that mice expressing ΔPrP or Dpl suffer from widespread leukoencephalopathy. Oligodendrocyte-specific expression of full-length PrPCunder control of the myelin basic protein (MBP) promoter repressed leukoencephalopathy and vastly extended survival but did not prevent cerebellar granule cell (CGC) degeneration. Conversely, neuron-specific PrPCexpression under control of the neuron-specific enolase (NSE) promoter antagonized CGC degeneration but not leukoencephalopathy. PrPCwas found in purified myelin and in cultured oligodendrocytes of both wild-type and MBP-PrP transgenic mice but not in NSE-PrP mice. These results identify white-matter damage as an extraneuronal PrP-associated pathology and suggest a previously unrecognized role of PrPCin myelin maintenance.
Integration Time in a Subset of Spinal Lamina I Neurons Is Lengthened by Sodium and Calcium Currents Acting Synergistically to Prolong Subthreshold Depolarization
Authors: Prescott Steven A. , De Koninck Yves
Published: May 2005

Lamina I of the spinal dorsal horn plays an important role in processing and relaying nociceptive information to the brain. It comprises physiologically distinct cell types that process information in fundamentally different ways: tonic neurons fire repetitively during stimulation and display prolonged EPSPs, suggesting operation as integrators, whereas single-spike neurons act like coincidence detectors. Using whole-cell recordings from a rat spinal slice preparation, we set out to determine the basis for prolonged EPSPs in tonic cells and the implications for signal processing. Kinetics of synaptic currents could not explain differences in EPSP kinetics. Instead, tonic neurons were found to express a persistent sodium current,INa,P, that amplified and prolonged depolarization in response to brief stimulation. Tonic neurons also expressed a persistent calcium current,ICa,P, that contributed to prolongation but not to amplification. Simulations using NEURON software demonstrated thatINa,Pwas necessary and sufficient to explain amplification, whereasINa,PandICa,Pacted synergistically to prolong depolarization: initial activation of the slower current (ICa,P) depended on the faster current (INa,P) but maintained activation of the faster current likewise depended on the slower current. Additional investigation revealed thatINa,PandICa,Pcould dramatically increase integration time (>30×) and thereby encourage temporal summation but at the expense of spike time precision. Thus, by prolonging subthreshold depolarization, intrinsic inward currents allow tonic neurons in spinal lamina I to specialize as integrators that are optimally suited to encode stimulus intensity.
Cortical Ensemble Adaptation to Represent Velocity of an Artificial Actuator Controlled by a Brain-Machine Interface
Authors: Lebedev Mikhail A. , Carmena Jose M. , O'Doherty Joseph E. , Zacksenhouse Miriam , Henriquez Craig S. , Principe Jose C. , Nicolelis Miguel A. L.
Published: May 2005

Monkeys can learn to directly control the movements of an artificial actuator by using a brain-machine interface (BMI) driven by the activity of a sample of cortical neurons. Eventually, they can do so without moving their limbs. Neuronal adaptations underlying the transition from control of the limb to control of the actuator are poorly understood. Here, we show that rapid modifications in neuronal representation of velocity of the hand and actuator occur in multiple cortical areas during the operation of a BMI. Initially, monkeys controlled the actuator by moving a hand-held pole. During this period, the BMI was trained to predict the actuator velocity. As the monkeys started using their cortical activity to control the actuator, the activity of individual neurons and neuronal populations became less representative of the animal's hand movements while representing the movements of the actuator. As a result of this adaptation, the animals could eventually stop moving their hands yet continue to control the actuator. These results show that, during BMI control, cortical ensembles represent behaviorally significant motor parameters, even if these are not associated with movements of the animal's own limb.
The Neurosteroid Allopregnanolone Promotes Proliferation of Rodent and Human Neural Progenitor Cells and Regulates Cell-Cycle Gene and Protein Expression
Authors: Wang Jun Ming , Johnston Patrick B. , Ball Bret Gene , Brinton Roberta Diaz
Published: May 2005

Our previous research demonstrated that the neuroactive progesterone metabolite allopregnanolone (3α-hydroxy-5α-pregnan-20-one) rapidly induced hippocampal neuron neurite regression (Brinton, 1994). We hypothesized that allopregnanolone-induced neurite regression was a prelude to mitogenesis initiated by a rise in intracellular calcium. Supporting this hypothesis, the current data demonstrate that allopregnanolone, in a dose-dependent manner, induces a significant increase in proliferation of neuroprogenitor cells (NPCs) derived from the rat hippocampus and human neural stem cells (hNSCs) derived from the cerebral cortex. Proliferation was determined by incorporation of bromodeoxyuridine and [3H]thymidine, fluorescence-activated cell sorter analysis of murine leukemia virus-green fluorescent protein-labeled mitotic NPCs, and total cell number counting. Allopregnanolone-induced proliferation was isomer and steroid specific, in that the stereoisomer 3β-hydroxy-5β-pregnan-20-one and related steroids did not increase [3H]thymidine uptake. Immunofluorescent analyses for the NPC markers nestin and Tuj1 indicated that newly formed cells were of neuronal lineage. Furthermore, microarray analysis of cell-cycle genes and real-time reverse transcription-PCR and Western blot validation revealed that allopregnanolone increased the expression of genes that promote mitosis and inhibited the expression of genes that repress cell proliferation. Allopregnanolone-induced proliferation was antagonized by the voltage-gated L-type calcium channel (VGLCC) blocker nifedipine, consistent with the finding that allopregnanolone induces a rapid increase in intracellular calcium in hippocampal neurons via a GABA type A receptor-activated VGLCC (Son et al., 2002). These data demonstrate that allopregnanolone significantly increased rat NPC and hNSC proliferation with concomitant regulation in mitotic cell-cycle genes via a VGLCC mechanism. The therapeutic potential of allopregnanolone as a neurogenic molecule is discussed.
Mouse Period1 (mPER1) Acts as a Circadian Adaptor to Entrain the Oscillator to Environmental Light/Dark Cycles by Regulating mPER2 Protein
Authors: Masubuchi Satoru , Kataoka Noritoshi , Sassone-Corsi Paolo , Okamura Hitoshi
Published: May 2005

Mouse period1(mPer1) andmPer2are mammalian homologs of theDrosophilaclock geneperiodthat show robust oscillation in the suprachiasmatic nucleus, the mammalian master clock, and have been implicated as essential components of the core clock mechanism. Gene-targeting studies have demonstrated thatmPer2plays a dominant function in behavioral rhythm generation, although the role ofmPer1has not been fully clarified. Here, we report that prolongation of the lighting period (4-16 h) induces a larger-delay phase shift of the behavioral rhythm inmPer1-deficient (mPer1-/-) mice. During the light-elongation task, mPER2 protein decay inmPer1-/-mice is slower (∼4 h) than in wild-type mice, which thereby causes larger behavioral phase delay.mPer1-/-mice could not adapt to environmental light/dark cycles in long complete photoperiods with dim light or in long skeleton photoperiods. These photoperiodic conditions mimic natural environmental changes present at high latitudes, indicating thatmPer1could operate in the adaptation of the circadian clock of nocturnal mice to large seasonal changes of environmental light/dark cycles.
Central Suppression of Regenerated Proprioceptive Afferents
Authors: Haftel Valerie K. , Bichler Edyta K. , Wang Qing-Bo , Prather Jonathan F. , Pinter Martin J. , Cope Timothy C.
Published: May 2005

Long after a cut peripheral nerve reinnervates muscle and restores force production in adult cats, the muscle does not respond reflexively to stretch. Motivated by the likelihood that stretch areflexia is related to problems with sensing and controlling limb position after peripheral neuropathies, we sought to determine the underlying mechanism. Electrophysiological and morphological measurements were made in anesthetized rats having one of the nerves to the triceps surae muscles either untreated or cut and immediately rejoined surgically many months earlier. First, it was established that reinnervated muscles failed to generate stretch reflexes, extending observations of areflexia to a second species. Next, multiple elements in the sensorimotor circuit of the stretch reflex were examined in both the PNS and CNS. Encoding of muscle stretch by regenerated proprioceptive afferents was remarkably similar to normal, although we observed some expected abnormalities, e.g., increased length threshold. However, the robust stretch-evoked sensory response that arrived concurrently at the CNS in multiple proprioceptive afferents produced synaptic responses that were either smaller than normal or undetectable. Muscle stretch failed to evoke detectable synaptic responses in 13 of 22 motoneurons, although electrical stimulation generated monosynaptic excitatory postsynaptic potentials that were indistinguishable from normal. The ineffectiveness of muscle stretch was not attributable therefore to dysfunction at synapses made between regenerated Ia afferents and motoneurons. Among multiple candidate mechanisms, we suggest that centrally controlled neural circuits may actively suppress the sensory information encoded by regenerated proprioceptive afferents to prevent recovery of the stretch reflex.
In VivoPerformance of Genetically Encoded Indicators of Neural Activity in Flies
Authors: Reiff Dierk F. , Ihring Alexandra , Guerrero Giovanna , Isacoff Ehud Y. , Joesch Maximilian , Nakai Junichi , Borst Alexander
Published: May 2005

Genetically encoded fluorescent probes of neural activity represent new promising tools for systems neuroscience. Here, we present a comparativein vivoanalysis of 10 different genetically encoded calcium indicators, as well as the pH-sensitive synapto-pHluorin. We analyzed their fluorescence changes in presynaptic boutons of theDrosophilalarval neuromuscular junction. Robust neural activity did not result in any or noteworthy fluorescence changes when Flash-Pericam, Camgaroo-1, and Camgaroo-2 were expressed. However, calculated on the raw data, fractional fluorescence changes up to 18% were reported by synapto-pHluorin, Yellow Cameleon 2.0, 2.3, and 3.3, Inverse-Pericam, GCaMP1.3, GCaMP1.6, and the troponin C-based calcium sensor TN-L15. The response characteristics of all of these indicators differed considerably from each other, with GCaMP1.6 reporting high rates of neural activity with the largest and fastest fluorescence changes. However, GCaMP1.6 suffered from photobleaching, whereas the fluorescence signals of the double-chromophore indicators were in general smaller but more photostable and reproducible, with TN-L15 showing the fastest rise of the signals at lower activity rates. We show for GCaMP1.3 and YC3.3 that an expanded range of neural activity evoked fairly linear fluorescence changes and a corresponding linear increase in the signal-to-noise ratio (SNR). The expression level of the indicator biased the signal kinetics and SNR, whereas the signal amplitude was independent. The presented data will be useful forin vivoexperiments with respect to the selection of an appropriate indicator, as well as for the correct interpretation of the optical signals.
Chromatic Gain Controls in Visual Cortical Neurons
Authors: Solomon Samuel G. , Lennie Peter
Published: May 2005

Although the response of a neuron in the visual cortex generally grows nonlinearly with contrast, the spatial tuning of the cell remains stable. This is thought to reflect the activity of a contrast gain control (“normalization”) that has very broad tuning on the relevant stimulus dimension. Contrast invariant tuning on a particular dimension is probably necessary for reliable representation of stimuli on that dimension. In the lateral geniculate nucleus (LGN), V1, and V2 of anesthetized macaque, we measured chromatic tuning of neurons at several contrasts to characterize the gain controls and identify cells that might be important for representing color. We estimated separately the chromatic signature of the linear receptive field and that of the gain control. In the LGN, we found normalization in magnocellular cells and cells receiving excitatory S-cone input but not in parvocellular cells or those receiving inhibitory S-cone input. We found normalization in all types of cortical neurons. Among cells that preferred achromatic modulation, or modulation along intermediate directions in color space (making them responsive to both achromatic and chromatic stimuli), normalization was driven by mechanisms tuned to a restricted range of directions in color space, close to achromatic. As a result, chromatic tuning varied with contrast. Among the relatively few cells that strongly preferred chromatic modulation, normalization was driven by mechanisms sensitive to modulation along all directions in color space, especially isoluminant. As a result, chromatic tuning changed little with contrast. To the extent that contrast invariant tuning is important in representing chromaticity, relatively few cortical neurons are involved.
Potential Effects of Jaw Tag Loss on Exploitation Estimates for Lake Erie Walleyes
Authors: Isermann Daniel A. , Knight Carey T.
Published: May 2005

We used mark–recapture data collected from 1992 to 1995 to evaluate the potential effects of jaw tag loss on exploitation (u) estimates for walleyes Sander vitreus migrating from Lake Erie into the Grand River, Ohio. Loss of small jaw tags (size 10) detected during tagging periods was less than 17%. The annual loss rate of small tags exceeded 49% during each of the 2 years in which they were used. We detected no loss of large tags (size 12) during tagging periods, and annual rates of large-tag loss ranged from 23% to 50%. Exploitation rates adjusted for tag loss ranged from 14% to 39%, and unadjusted estimates ranged from 7% to 20%. Failure to adjust for annual tag loss rates resulted in 25–59% underestimation of u; however, error rates may be inflated due to a lack of knowledge concerning temporal patterns in tag loss. Our findings indicate that jaw tag loss rates must be accounted for when estimating population parameters such as u from mark–recapture studies. Furthermore, if agency personnel are able to analyze large samples of harvested fish for tags, the use of internal tag types that typically exhibit higher retention rates than jaw tags could reduce tag loss and eliminate biases due to nonreporting.
Associations among Selection Logging History, Brook Trout, Macroinvertebrates, and Habitat in Northern Michigan Headwater Streams
Authors: VanDusen Peter J. , Huckins Casey J. F. , Flaspohler David J.
Published: May 2005

Selection logging is a dominant forest management technique in mixed‐hardwood forests of the Laurentian Great Lakes region, yet little is known about its potential effects on neighboring streams and their communities. We surveyed nine headwater streams of the Otter River watershed in Michigan's Upper Peninsula for which the adjacent forest had undergone selection logging in the previous 2 to 30 years to examine whether the abundance of brook troutSalvelinus fontinaliswas related to the logging history, stream habitat conditions, or aquatic macroinvertebrate composition. Mean abundances of age‐1 and older brook trout were estimated by electrofishing replicate 100‐m sections of each stream in 1999 and 2000. Aquatic macroinvertebrates were surveyed in 1999, and stream habitat was surveyed in 2000. Correlation models showed that brook trout density and biomass were substantially lower in streams bordering more recently logged forests. Brook trout abundance was also positively correlated with the relative combined abundance of the disturbance‐sensitive taxa Ephemeroptera, Plecoptera, and Trichoptera (EPT), which is an indicator of coldwater stream habitat quality. Streams in recently logged stands had substrates with higher fine sediment content and lower overall habitat quality as estimated by a multimetric habitat index. Neither brook trout density nor EPT was correlated with the abundance of fine sediments in the streams. Fine sediment abundance was negatively related to stream canopy cover. Volume of instream woody debris and other specific elements of instream habitat were not significantly correlated with years since logging, nor did they explain significant variation in biotic variables. Results from this chronological‐sequence comparison study suggest that selection logging alters stream habitat and influences associated stream communities, although the specific mechanistic linkages remain to be determined.
Patterns of Tobacco Use in the Early Epidemic Stages: Malawi and Zambia, 2000–2002
Authors: Pampel Fred C.
Published: May 2005

Objectives. I examined demographic and socioeconomic patterns of tobacco use in 2 African nations in the early stages of epidemic.

Methods. I used population-based data from the Demographic Health Surveys of men aged 15–59 years (N=5111) and women aged 15–49 years (N=20809) in Malawi (2000) and Zambia (2001/2002) and multinomial logistic regression models to examine tobacco use (nonsmoker, light cigarette smoker, heavy cigarette smoker, and user of other tobacco) as a function of age, residence, education, occupation, marital status, and religion.

Results. Male tobacco users tend to be less educated, urban, household service or manual workers, formerly married, and non-Christian and non-Muslim. Although tobacco use is less common among women, it relates inversely to their education and occupational status. Tobacco users more often reported drinking, getting drunk, and, among men, paying for sex.

Conclusions. Tobacco use patterns in 2 African nations at the early stages of epidemic suggest the need for public health officials to focus on disadvantaged groups to prevent the worldwide spread of tobacco.
Al6Ti2O13, a New Phase in the Al2O3—TiO2 System.
Authors: Norberg Stefan T. , Hoffmann Stefan , Yoshimura Masahiro , Ishizawa Nobuo
Published: May 2005

For Abstract see ChemInform Abstract in Full Text.
Clean and Highly Selective Oxidation of Alcohols in an Ionic Liquid by Using an Ion‐Supported Hypervalent Iodine(III) Reagent.
Authors: Qian Weixing , Jin Erlei , Bao Weiliang , Zhang Yongmin
Published: May 2005

For Abstract see ChemInform Abstract in Full Text.
Facile Synthesis of Polycyclic Aromatic Hydrocarbons via a Trisaryne Equivalent.
Authors: Ikadai Junnai , Yoshida Hiroto , Ohshita Joji , Kunai Atsutaka
Published: May 2005

For Abstract see ChemInform Abstract in Full Text.
Synthesis and Properties of Some N‐Substituted Derivatives of Oxazolidine and Morpholine.
Authors: Magerramov A. M. , Magerramov M. N. , Makhmudova Kh. A. , Alizade G. I.
Published: May 2005

For Abstract see ChemInform Abstract in Full Text.
Gas‐Phase Ion Chemistry of Simple 1,4‐Benzodiazepines. Part 1.
Authors: Giorgi Gianluca
Published: May 2005

For Abstract see ChemInform Abstract in Full Text.
Bacterial colonization on different suture materials—A potential risk for intraoral dentoalveolar surgery
Authors: Otten J.‐E. , Wiedmann‐Al‐Ahmad M. , Jahnke H. , Pelz K.
Published: May 2005

In this in vivo and in vitro study on resorbable (Monocryl®) and nonresorbable (Deknalon®) monofilament sutures used in intraoral dentoalveolar surgery the bacterial colonization was compared. For the in vivo study the sutures were applied in 11 patients during dental surgery. Eight days postoperative the sutures were removed and the adhered bacteria were isolated and identified by biochemistry, morphology, antibiotic susceptibility, and gaschromatography. The colonization was studied by scanning electron microscopy. Aerobic and anaerobic bacteria were isolated in nearly equal colony‐forming units (cfu) on each suture. In comparison with Monocryl® about 15% more aerobic and anaerobic strains were isolated on Deknalon®. Regarding the pathogens only, about three times more anaerobic strains were isolated on both sutures in total. Additionally, more pathogens were found on Deknalon® than on Monocryl® (aerobic >40%, anaerobic >25%). The variety of bacteria correspond with purulent infections, not with normal oral flora. Intraindividual comparisons of cfu showed differences in dependence of the patient as described for subgingivale plaques. For the in vitro study the sutures were incubated with Streptococcus intermedius and Prevotella intermedia for 0.5 h. Scanning electron microscopy was performed to examine qualitatively the level of bacterial adherence. After 0.5 h the bacteria adhered very well. The colonization rate of Streptococcus intermedius on both sutures was similar. Coccoid bacteria within biofilms were seen. The growth of Prevotella intermedia was much better on Deknalon® than on Monocryl®. The risk of bacteremia at the time of suture removal is discussed. © 2005 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2005
Antibiotic prophylaxis in “clean” surgical procedures
Authors: Strachan Colin
Published: May 2005

The incidence of infection for clean surgical procedures should be less than 2%. The majority of infections are exogenous fromStaphylococcus aureus.These exogenous sources of bacteria include the ward, the theater environment, medical personnel, bed linen, and other infected patients. Endogenous infections may arise from the patient's own nose and skin; and although the majority of bacteria are staphylococcal, gram‐negative intestinal bacteria may colonize the skin around the perineum and are, therefore, important pathogens in hip replacement and aortobifemoral grafts. Methods of reducing exogenous infection include theater discipline, ultra clean air, surgical scrub, and isolating infected patients on the ward. Endogenous infections may be minimized by avoiding prolonged preoperative hospital stay, careful shaving only around the incision, and skin preparation with iodophors or chlorhexidine in alcohol. There is no place for antibiotic prophylaxis in clean surgical operations, provided the patient has a normal defense mechanism and provided a foreign body is not being implanted into bone or the circulation. Because of the morbidity and potential mortality of infected implants, antibiotics should be used in clean prosthetic surgery.
Prevention of sepsis in gastroesophageal surgery
Authors: Muscroft T. J. , Deane S. A.
Published: May 2005

Sepsis is a common complication of gastric operations, particularly in hypochlorhydric patients such as those with gastroesophageal carcinoma, gastric ulcer, or if revision gastric surgery is required for bile gastritis. By contrast, the risks of sepsis are small for patients with a duodenal ulcer having a proximal gastric vagotomy. The risks of endogenous sepsis are determined by the preoperative bacterial flora of the stomach. High preoperative bacterial counts are rare if the fasting pH is less than 4.0, hence cimetidine therapy given immediately before operation could increase the risk of endogenous sepsis. Systemic antimicrobial prophylaxis with a broad‐spectrum cephalosporin or penicillin is advised for all patients receiving cimetidine before operation, for all patients requiring gastric resection or revision gastric operations, and for any others in whom the preoperative gastric pH is 4.0 or more.
Clinical trials of antimicrobials in surgery
Authors: Watts James K. , McDonald Peter J. , Woods Pamela J.
Published: May 2005

Many clinical trials of antimicrobials to prevent surgical infection are poorly designed and may, therefore, indicate policies that are misleading. This paper provides guidelines for trial design including statistical planning and analysis.

Satisfactory trials have been carried out in most branches of surgery, but there is still a need to define patients at special risk of infection and to design trials within these groups. There is also a need to perform trials to validate current practice and to establish the cheapest, least toxic, and most effective antimicrobial regimens.

Well‐designed trials require little analysis, but the results of a poorly planned trial cannot be retrieved even by statistical methods.
A rational approach to antibiotic prophylaxis in surgery
Authors: Keighley M. R. B.
Published: May 2005

Antibiotic prophylaxis should be used a) where the risk of infection is high; b) where bacterial contamination is high; where contamination is infrequent but the consequences of infection are high; and c) where contamination is infrequent but the host is compromised. Careful attention should be given the selection of an appropriate agent for the given circumstance. Timing and route of administration are also important factors.
The effect of cholestasis on hepatic clearance of bacteria
Authors: Cardoso Valdemar , Pimenta Amadeu , Correia da Fonseca J. , Rodrigues J. Sousa , Vaz Maria José Machado
Published: May 2005

Normal dogs and dogs with experimental cholestasis were inoculated intravenously withEscherichia coli.A study of the curves for bacterial blood clearance and bacterial appearance in the bile followed. In the normal dogs, bacteria rapidly disappeared from the blood; no bacteria were detected in the bile of these animals. In the jaundiced dogs, not only did the bacteria disappear from the blood less rapidly, but also appeared in the bile almost simultaneously. The different possible mechanisms for this activity are discussed. The results obtained may lead to a better understanding of the great incidence of infection in cases of biliary obstruction.
Wounds of the portal venous system
Authors: Stone H. Harlan , Fabian Timothy C. , Turkleson Margaret L.
Published: May 2005

During a 23‐year interval, 83 patients with wounds of the portal and/or superior mesenteric veins underwent emergency laparotomy. Six (7%) of the injuries were due to blunt trauma, while penetrating wounds accounted for the remaining 77 (93%). With one exception, associated organ injuries were routinely present and involved 120 other major vascular structures in 59 (71%) of the patients. Five patients with both portal and superior mesenteric vein injury and 3 others with isolated portal venous injury exsanguinated before repair could be accomplished.

Lateral phleborrhaphy gave survival in 24 of 34 patients so treated. End‐to‐end reanastomosis of the portal vein was successful in only 1 of 3 patients on whom it was attempted, while the single portacaval shunt led to a metabolic death. Of the initial 17 patients having vein ligation as a desperation measure, there were 7 survivors. Subsequent immediate application of this technique whenever lateral repair was impossible or impractical was successful in 17 of 20 so managed.

Death resulted from hemorrhagic shock (20), its attendant coagulopathy (7), or renal failure (2) in 29 patients. Two deaths were the result of failure to over‐transfuse appropriately when portal venous ligation or thrombosis with its attendant splanchnic sequestration led to significant peripheral hypovolemia. The overall mortality rate was 41%, with individual mortality rates of 46% and 27% for the portal and superior mesenteric veins, respectively. There was no survival if both veins had been injured.
Recurrent laryngeal nerve anastomosis following thyroid surgery
Authors: Ezaki Haruo , Ushio Hiroki , Harada Yasuo , Takeichi Nobuo
Published: May 2005

End‐to‐end anastomosis of the recurrent laryngeal nerve had been abandoned because movement of the vocal cords could not be restored because of misdirected regeneration. However, the authors discovered that, although vocal cord movement could not be restored, phonation was better in those in whom the recurrent laryngeal nerve was anastomosed than in those in whom it had been left in the severed state. Hoarseness improves after nerve anastomosis because it prevents vocal cord atrophy and the vocal cord gap is smaller. End‐to‐end anastomosis of the recurrent laryngeal nerve is, therefore, considered to be of value.
Diagnosis of acute pancreatitis using the amylase‐creatinine clearance ratio and radionuclide hepatobiliary and pancreas imaging
Authors: Orda Ruben , Orda Sara , Baron Jack , Wiznitzer Theodor
Published: May 2005

Amylase‐creatinine clearance ratio and radionuclide hepatobiliary and pancreas imaging were used together as noninvasive screening procedures in 24 patients suspected of having acute pancreatitis. An increased amylase‐creatinine clearance ratio, normal filling of the gallbladder demonstrated by the radionuclide study, and decreased uptake of the radionuclide in the pancreas scan were helpful in reaching the diagnosis of acute pancreatitis.
An appraisal of transcatheter arterial embolization combined with transcatheter arterial infusion of chemotherapeutic agent for hepatic malignancies
Authors: Okamura Jun , Horikawa Shinichi , Fujiyama Takeo , Monden Morito , Kambayashi Junichi , Sikujara Osman , Sakurai Masami , Kuroda Chikazumi , Nakamura Hironobu , Kosaki Goro
Published: May 2005

Transcatheter arterial embolization (TAE) combined with transcatheter arterial infusion (TAI) was done in 58 patients with unresectable hepatic malignancies. The actuarial 1‐year survival rate of the patients was 56.2%. Elective hepatic resection was performed on 10 patients following these procedures. These patients are all doing well. Complete tumor necrosis was demonstrated in 5 of these 10 patients by pathohistological studies on resected specimens from 1 to 11 months after surgery. These tumors were solitary, small (less than 4 cm in diameter), encapsulated, and located deeply inside the liver, being supplied by a single artery. In the other 5 patients, tumor cells in the main tumor and/or in daughter nodules were viable. We conclude that TAE combined with TAI was justified for treatment of hepatic malignancies in selected cases.
Laboratory and clinical evaluation of a membrane oxygenator with secondary flows in the blood channels
Authors: Karlson Karl E. , Massimino Ronald J. , Singh Arun K. , Cooper George N.
Published: May 2005

A microporous membrane oxygenator which has transverse furrows on the membrane surface has been used in 50 clinical cardiopulmonary bypass procedures for coronary revascularization. The transverse furrows on the membrane, together with intermittent rapid pulsatile reversal of the blood flow in the blood film, produce secondary flows in the film and increase exposure of desaturated blood to the membrane. Venous drainage flows into a plastic reservoir, from which it is pumped through the oxygenator and integral heat exchanger into the aorta of the patient. Perfusions were carried out with hemodilution and moderate hypothermia. The oxygenator was ventilated with oxygen. In experimental perfusions using calves, the oxygen transfer was as high as 371 ml/min. During the clinical perfusions, arterial oxygen saturation was always 98% or higher. The mean arterial carbon dioxide tension was 41 mm Hg at a mean O2 flow of 1.4 L/min. The mean arterial pH was 7.40. The oxygenator puiser which created the secondary flows in the blood film was operated at a rate of between 90 and 255 pulses per minute. Pressure drop across the oxygenator averaged 18 mm Hg. Oxygen tension in the arterial blood could be regulated with the pulser rate, greater pulser rates being associated with larger oxygen transfer. Carbon dioxide transfer was best regulated by changes in gas flow rate. The oxygenator functioned well and was safe and reliable during these 50 perfusions.
Cost of nosocomial infections: Analysis of 512 digestive surgery patients
Authors: Fabry J. , Meynet R. , Joron M. T. , Sepetjan M. , Lambert D. C. , Guillet R.
Published: May 2005

The present report of 512 consecutive patients hospitalized for common digestive surgery assesses the medical outcome of nosocomial infection (NI) using Center for Disease Control criteria. Medical and social costs were evaluated for the hospitalization period and for the 6 months following. Estimate of cost directly due to NI represents 6.8% of total expenditures for the entire group of 512 patients.