Reliability of patient self-report of cognition, awareness, and consciousness during seizures

Objective

Clinicians rely on patient self‐report of impairment during seizures for decisions including driving eligibility. However, the reliability of patient reports on cognitive and behavioral functions during seizures remains unknown.

Methods

We administered a daily questionnaire to epilepsy patients undergoing continuous video‐EEG monitoring, asking about responsiveness, speech, memory, awareness, and consciousness during seizures in the preceding 24 hours. We also administered a questionnaire upon admission about responsiveness, speech, and awareness during seizures. Subjective questionnaire answers were compared with objective behavioral ratings on video review. Criteria for agreement were Cohen’s kappa >0.60 and proportions of positive and negative agreement both >0.75.

Results

We analyzed 86 epileptic seizures in 39 patients. Memory report on the daily questionnaire met criteria for agreement with video review (κ = 0.674 for early, 0.743 for late recall). Subjective report of awareness also met agreement criteria with video ratings of memory (κ = 0.673 early, 0.774 late). Concordance for speech was relatively good (κ = 0.679) but did not meet agreement criteria, nor did responsiveness or consciousness. On the admission questionnaire, agreement criteria were met for subjective report of awareness versus video ratings of memory (κ = 0.814 early, 0.806 late), but not for other comparisons.

Interpretation

Patient self‐report of memory or awareness showed the best concordance with objective memory impairment during seizures. Self‐report of impairment in other categories was less reliable. These findings suggest that patient reports about impaired memory during seizures may be most reliable, and otherwise determining functional impairments should be based on objective observations.

Mirogabalin as a Novel Gabapentinoid for the Treatment of Chronic Pain Conditions: An Analysis of Current Evidence

: Neuropathic pain is a challenge for physicians to treat and often requires a multimodal approach with both pharmacologic and lifestyle interventions. Mirogabalin, a potent, selective ligand of the α2δ-1 and α2δ-2 subunits of voltage-gated calcium channels (VGCCs), provides analgesia by inhibiting neurotransmitter release at the presynaptic end of the neuron. Mirogabalin offers more sustained analgesia than its gabapentinoid counterparts in addition to a wider safety margin for adverse events. Recent clinical trials of mirogabalin have demonstrated both efficacy and tolerability of the drug for the treatment of diabetic peripheral neuropathic pain and postherpetic neuralgia, leading to its approval in Japan. While still not yet FDA approved, mirogabalin is still in its infancy and offers potential into the treatment of neuropathic pain and its associated comorbidities.

An Analysis of Anesthesia Induction Dosing in Female Older Adults

BACKGROUND/OBJECTIVES

In the context of an aging surgical population, appropriate anesthetic induction dose adjustments for the older adult remain poorly defined. In the present study, we describe the prevalence of excess induction agent dose in reference to US Food and Drug Administration (FDA) guidance and seek to investigate the possible association of such excess dose with postinduction hypotension and postoperative acute kidney injury (AKI).

STUDY DESIGN

A retrospective observational study was conducted in a large tertiary teaching hospital in accordance with our a priori analytic protocol as registered on ClinicalTrials.gov (NCT03699696). For inclusion, patients had to be 65 years or older and to have received general anesthesia with propofol induction for gynecologic oncology surgery between December 1, 2014 and July 8, 2018. Descriptive variables of the patients, machine-captured perioperative vital signs, induction anesthetic, and vasopressor/inotrope administrations were recorded.

MAIN OUTCOME MEASURES

A total of 541 female patients met inclusion criteria. The mean (standard deviation) age of the cohort was 72.20 (5.93) years. Regarding the primary outcome, 65.43% (354 patients, 95% confidence interval 61.2-69.4) of the cohort received more than the FDA recommended 1-1.5 mg/kg induction dose for patients of advanced age undergoing general anesthesia.

RESULTS

The percentage of patients receiving doses in excess of the FDA guidance remained substantial across all age groups, but decreased progressively with increasing 5-year age intervals (from 74% among those aged 65-69 years to 44% among those aged > 80 years). Excess propofol dose in the present cohort was not associated with our a priori definition of postinduction hypotension. Regarding AKI, among the 30 patients suffering this outcome, it occurred less often in patients who received higher propofol doses (4.1% [9/217] vs. 15.3% [21/138], p < 0.001), a result that may have been confounded by differential rates of missingness.

CONCLUSIONS

Older adults commonly receive propofol induction doses in excess of the FDA guidance. The immediate hemodynamic effects of these doses on postinduction hypotension were not seen in the present cohort, suggesting that propofol dose adjustments may serve as a marker of physicians' judgments as to the frailty of patients. The relevance of the AKI association is difficult to interpret due to the non-differential missingness of AKI data between the two groups.

Chronic Prescription Opioid Use Before and After Total Hip and Knee Arthroplasty in Patients Younger Than 65 Years

BACKGROUND

Opioids are commonly prescribed to patients with painful and symptomatic degenerative joint disease preoperatively as a nonoperative intervention to reduce patients' symptoms and pain. The goal of total joint arthroplasty (TJA) is to reduce or eliminate the painful symptoms of degenerative joint disease. Due to the addictive property of opioid medications, some patients may develop a pattern of chronic opioid use after TJA.

METHODS

We used MarketScan Commercial Claims and Encounters database to identify 125,019 patients (age <65 years) who underwent total knee arthroplasty (TKA) and total hip arthroplasty (THA) between 2009 and 2012. During the study period, opioid use was analyzed 3 months before surgery and at 12 months after surgery. We defined chronic opioid use as having 2 or more opioid prescriptions filled within any 6-week period. Multivariate logistic regression was used.

RESULTS

Of the 24,127 patients who were chronic prescription opioid users before surgery, 72% were no longer chronic users 1 year after surgery. Of the 100,892 patients who were nonusers before surgery, 4% became chronic users within 1 year after surgery. TKA and hospital stay longer than 3 days were significant risk factors of persisting chronic opioid use after surgery, while age played a mixed role in predicting change of opioid use.

CONCLUSION

Using our definition of chronic use, overall chronic opioid use decreased from 19% to 9% after TJA. Patients were more likely to cease chronic opioid use after TJA (72%) than to become chronic users (4%).

Engineering Efficient Photon Upconversion in Semiconductor Heterostructures

Photon upconversion is a photophysical process in which two low-energy photons are converted into one high-energy photon. Photon upconversion has broad appeal for a range of applications from biomedical imaging and targeted drug release to solar energy harvesting. Current upconversion nanosystems, including lanthanide-doped nanocrystals and triplet-triplet annihilation molecules, have achieved upconversion quantum yields on the order of 10-30%. However, the performance of these materials is hampered by inherently narrow absorption cross sections and fixed energy levels originating in atomic, ionic, or molecular states. Semiconductors, on the other hand, have inherently wide absorption cross sections. Moreover, recent advances enable the synthesis of colloidal semiconductor nanoparticles with complex heterostructures that can control band alignments and tune optical properties. We synthesize and characterize a three-component heterostructure that successfully upconverts photons under continuous-wave illumination and solar-relevant photon fluxes. The heterostructure is composed of two cadmium selenide quantum dots (QDs), an absorber and emitter, spatially separated by a cadmium sulfide nanorod (NR). We demonstrate that the principles of semiconductor heterostructure engineering can be applied to engineer improved upconversion efficiency. We first eliminate electron trap states near the surface of the absorbing QD and then tailor the band gap of the NR such that charge carriers are funneled to the emitting QD. When combined, these two changes result in a 100-fold improvement in photon upconversion performance.

Bendamustine with rituximab, etoposide and carboplatin (T(R)EC) in relapsed or refractory aggressive lymphoma: a prospective multicentre phase 1/2 clinical trial

We sought to develop a safe and effective outpatient salvage regimen by replacing ifosfamide within the (R)ICE (rituximab, ifosfomide, carboplatin, etoposide) regimen with bendamustine (T(R)EC) via a multicentre phase I/II study for patients with relapsed or refractory diffuse large B cell lymphoma (DLBCL) and classic Hodgkin lymphoma (HL). Therapy consisted of 60-120 mg/m2 per day bendamustine on days 1 and 2 in combination with carboplatin, etoposide and rituximab (only for CD20+ lymphoma) used in the (R)ICE regimen for up to 2 cycles. The objectives were to define a maximally tolerated dose (MTD) of bendamustine, determine safety and toxicity, assess efficacy, and evaluate impact on stem cell collection. Forty-eight patients were treated of which 71% had refractory disease. No dose-limiting toxicities were observed. The recommended phase II dose of bendamustine was 120 mg/m2 per day on days 1 and 2. Response rates were 85% (70% complete response, CR) in HL, and 65% (40% CR) in DLBCL. Stem cell collection was successful in 30 of 32 patients. The most common non-haematological toxicities ≥grade 3 were febrile neutropenia (8%) and dehydration (8%). The T(R)EC regimen safely yields high response rates, successfully mobilizes peripheral blood stem cells and compares favourably to RICE, offering an effective outpatient treatment option for patients with relapsed or refractory DLBCL and HL.

Correlation Between 24-Hour Predischarge Opioid Use and Amount of Opioids Prescribed at Hospital Discharge

Importance

The United States is experiencing an opioid abuse epidemic. Opioid overprescription by physicians may contribute to this epidemic.

Objectives

To determine if there was a correlation between a postoperative patient's 24-hour predischarge opioid use and the amount of opioids prescribed at hospital discharge and to determine the number of patients who used no opioids prior to discharge but were still prescribed opioids after hospital discharge.

Design, Setting, and Participants

This cross-sectional study performed a retrospective record review of 18 343 postoperative patients at Boston Medical Center and Lahey Hospital and Medical Center-Burlington Campus who were discharged home after a postoperative inpatient admission of at least 24 hours. Data collection spanned from May 22, 2014, to June 30, 2016, in the Boston Medical Center data set and from March 23, 2015, to September 7, 2016, in the Lahey Hospital and Medical Center-Burlington Campus data set.

Exposures

Surgery requiring a postoperative inpatient hospital stay longer than 24 hours.

Main Outcomes and Measures

The main outcome measures were the patient's 24-hour predischarge opioid use and the total quantity of opioids prescribed at hospital discharge. Potential overprescription was defined as the number of patients who used no opioids in the 24 hours prior to hospital discharge but were still prescribed opioids after hospital discharge.

Results

Among the 18 343 patients (10 069 women and 8274 men; mean age, 52.2 years) who underwent 21 452 surgical procedures, there was wide variation in the amount of opioids prescribed at hospital discharge given a postoperative patient's 24-hour predischarge opioid use. A total of 6548 patients (35.7%) used no opioids in the 24 hours prior to hospital discharge; however, 2988 of these patients (45.6%) were prescribed opioids at hospital discharge, suggesting potential overprescription. Services that had the highest rates of potential overprescription (obstetrics [adjusted odds ratio (AOR), 3.146; 95% CI, 2.094-4.765] and gynecology [AOR, 2.355; 95% CI, 1.663-3.390], orthopedics [AOR, 0.943; 95% CI, 0.719-1.242], and plastic surgery [AOR, 0.733; 95% CI, 0.334-1.682]) generally had the highest rates of patients still using opioids at hospital discharge. Pediatric surgery was the only service that did not have any cases of potential overprescription (AOR, 2.09 × 10-7; 95% CI, 0.000-0.016).

Conclusions and Relevance

Opioids are not regularly prescribed in a patient-specific manner to postoperative patients. Potential opioid overprescription occurs regularly after surgery among almost all surgical specialties.

A Pilot Analysis of the Association Between Types of Monitored Anesthesia Care Drugs and Outcomes in Transfemoral Aortic Valve Replacement Performed Without General Anesthesia

OBJECTIVE

The types of agents used for monitored anesthesia care (MAC) and their possible differential effects on outcomes have received less study despite increased use over general anesthesia (GA) in transfemoral aortic valve replacements (TAVRs). In this pilot analysis of patients undergoing TAVR using MAC, the authors described the anesthetic agents used and sought to investigate the possible association of anesthetic agent choice with outcomes and the extent to which total weight and time-adjusted doses of anesthetics declined with increasing 10-year age increments.

DESIGN

Retrospective observational study.

SETTING

Tertiary teaching hospital.

PARTICIPANTS

Ninety-three participants scheduled to undergo TAVR, with a primary plan of conscious sedation between November 2014 and June 2016, were included.

INTERVENTION

None.

MEASUREMENTS AND MAIN RESULTS

Types of MAC were divided into 4 primary groups, but 2 groups were focused: propofol (n = 39) and dexmedetomidine plus propofol (n = 34). Conversion to GA occurred in 6 participants (6.45%) and was not associated with the type of sedation received. The authors also compared patients who received dexmedetomidine with those who did not in accordance with their a priori analytic plan. There were no associations between the use of dexmedetomidine and postoperative delirium or intensive care unit/hospital length of stay. No significant trends in medication dose adjustments were seen across increasing 10-year age increments.

CONCLUSIONS

A wide breadth of MAC medications is in use among TAVR patients and does not support differences in outcomes. Despite recommendations to reduce anesthetic drug dosing in the elderly, no significant trends in dose reduction with increasing age were noted.

The behavioural homing response of adult chum salmon Oncorhynchus keta to amino-acid profiles

Adult chum salmon Oncorhynchus keta homing behaviour in a two-choice test tank (Y-maze) was monitored using a passive integrated transponder (PIT)-tag system in response to river-specific dissolved free amino-acid (DFAA) profiles and revealed that the majority of O. keta showed a preference for artificial natal-stream water and tended to stay in this maze arm for a longer period; natal-stream water was chosen over a nearby tributary's water, but not when the O. keta were presented with a non-tributary water. The results demonstrate the ability of O. keta to discriminate artificial stream waters containing natural levels of DFAA.

Regional initiative to use data transparency to improve cancer care

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Background: In the context of many initiatives aimed at measuring quality and value in cancer care, the Hutchinson Institute for Cancer Outcomes Research (HICOR) has adopted a multi-stakeholder approach to characterize oncology care, prioritize areas for improvement, design programs, and evaluate outcomes. Beginning in 2014, HICOR initiated a process to move towards data transparency in the reporting of regional quality and value metrics. Methods: The HICOR team constructed clinic-level adherence reports for community-prioritized metrics and the 2012 ASCO Choosing Wisely recommendations using a registry-claims linked database. In the fall of 2014, a national external advisory board reviewed methodology for measuring adherence. De-identified regional results were presented at a provider meeting in late 2014 to elicit provider feedback on methodology and on strategies for reporting clinic-identified adherence. Clinics were privately given their own adherence data. In 2015, revised de-identified regional reports were presented at a Value in Cancer Care Summit poster session and made available through HICOR IQ, a regional oncology informatics platform, for further discussion. Results: Results show that no clinic was also the best or worst performing clinic. The table shows the performance by clinic for the 5 Choosing Wisely recommendations. There is now increased demand by clinics to view their own adherence benchmarked with the region as a next step in moving towards full data transparency. Additionally, there is support from provider members in the community to re-identify clinics in order to compare results against their peers. Conclusions: Using an iterative, transparent, multi-stakeholder process, it is feasible build regional consensus towards releasing clinic-level adherence to quality and value metrics. By consulting trusted experts in the field and allowing multiple opportunities to provide feedback, providers are requesting even more transparency in order use the oncology measures to improve care in their practice and the region. [Table: see text]

Treatment prices at the point of care: Pilot

4

Background: People with cancer increasingly wish to discuss cancer care costs with clinicians. In our organization all price questions go to a central customer service line with limited capacity to address oncology-specific questions. We aimed to improve clinician access to treatment prices to assist them in responding to patient concerns about prices. Methods: We developed, launched, and evaluated a pilot tool and accompanying workflow for four oncology clinics in an integrated delivery system in WA. The online tool included a series of 50 printable worksheets for the most commonly ordered cancer treatment protocols accessible directly from the electronic health record. The worksheets included codes and prices for all drugs, supportive medications, tests, and professional services for one treatment cycle presented in patient-friendly language. We audited the accuracy of the cost information against patient bills. The worksheets did not provide patient-level cost-shares. We evaluated the resource’s launch, initial use, and acceptability through a convenience survey of initial users. Results: The project was successfully launched. Initial web traffic to price sheets exceeded the number of treatments being ordered during the launch period. A third of survey respondents (33%) reported using the cost sheets at least once a week. Reported most useful features were improved access to cost information, treatment protocol-based layout, and the service of previously unmet patient needs. Seventy percent (70%) reported that the resource had no impact on their workload. The mean value of the resource (1 lowest and 10 highest value) was 7.9 (value to patients); 7.8 (to oncology service line), 7.7 (to Group Health) and 6.5 (to own work or practice). Staff reporting of patient response was generally positive. Suggested improvements included provide patient-level cost share (63%) followed by expanding the project to include more protocols (33%). Conclusions: The pilot was feasible, built capacity to locate price data, and did not adversely impact staff workload. It addressed a clear need and demonstrated high potential overall value, especially its protocol-based format. The resource’s lack of personalized estimates of out-of-pocket charges was the biggest gap reported.

Value in cancer care: Regional initiative to improve care through data reporting and interventions

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Background: In the context of many initiatives aimed at measuring quality and value in cancer care, the Hutchinson Institute for Cancer Outcomes Research (HICOR), partnered with community members to launch a regional, stakeholder-driven initiative to define and report value metrics for cancer care for Washington State. Region-wide Summits were held in 2014 and 2015. Participants included local healthcare delivery organizations, patient advocacy groups, payers, and policymakers. The 2014 Summit identified priority metrics; these metrics were reported at the 2015 Summit. Methods: For the 2015 Summit, HICOR staff developed algorithms to measure adherence to the community-prioritized metrics using a claims-registry linked database. Metrics spanned diagnosis, treatment, continuing, and end-of-life (EOL) phases of care. After reviewing adherence at the clinic-level and for the region, attendees were invited to attend break-out sessions for metrics where there was the largest variation: hospital and ED use during treatment, hospital and ED use at EOL, and breast cancer surveillance. Within the breakout sessions, participants were asked to identify barriers to adherence and possible interventions to improve care. After discussion, participants individually ranked the top 3 interventions and estimated expected improvement to be gained by successful implementation of the intervention Results: Table. Working groups were formed to develop detailed protocols for implementable interventions. Conclusions: Using an iterative, transparent, multi-stakeholder process, it is feasible build regional consensus to identify and prioritize value metrics in cancer care, and to develop consensus regarding approaches to improve adherence to those metrics. [Table: see text]

Skeletal Muscle Oxygenation Measured by EPR Oximetry Using a Highly Sensitive Polymer-Encapsulated Paramagnetic Sensor

We have incorporated LiNc-BuO, an oxygen-sensing paramagnetic material, in polydimethylsiloxane (PDMS), which is an oxygen-permeable, biocompatible, and stable polymer. We fabricated implantable and retrievable oxygen-sensing chips (40 % LiNc-BuO in PDMS) using a 20-G Teflon tubing to mold the chips into variable shapes and sizes for in vivo studies in rats. In vitro EPR measurements were used to test the chip's oxygen response. Oxygen induced linear and reproducible line broadening with increasing partial pressure (pO2). The oxygen response was similar to that of bare (unencapsulated) crystals and did not change significantly on sterilization by autoclaving. The chips were implanted in rat femoris muscle and EPR oximetry was performed repeatedly (weekly) for 12 weeks post-implantation. The measurements showed good reliability and reproducibility over the period of testing. These results demonstrated that the new formulation of OxyChip with 40 % LiNc-BuO will enable the applicability of EPR oximetry for long-term measurement of oxygen concentration in tissues and has the potential for clinical applications.

Regional initiative to define, collect, and report value metrics in cancer care

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Background: In the context of numerous national initiatives aimed at measuring quality and value in cancer care, the Hutchinson Institute for Cancer Outcomes Research, in partnership with local healthcare delivery organizations, patient advocacy groups, payers, and policymakers launched a regional, stakeholder-driven initiative to define 3-5 “value-based metrics” for cancer care for Washington State. Methods: Representatives from major cancer care delivery organizations, patient advocacy groups, payers, and policymakers were invited to participate in a day-long Value Summit. Attendees were tasked with identifying metrics that considered both costs and outcomes. Trained facilitators helped participants identify metrics for 9 domains: appropriate use of effective therapies, adherence to best practices, survival, comprehensive disease management, efficiency of care, hospice/palliative care, patient and family satisfaction with care, patient reported outcomes/preferences and safety. After the initial list was generated, attendees were then asked to rank the metrics on the basis of feasibility to collect, clinical relevance, ability to act on, meaningfulness to multiple stakeholders, and willingness to report statewide. Attendees were then asked to participate in 3 domain-specific facilitated breakout sessions to prioritize the top metrics for each domain. Breakout sessions reported top metrics for a final group prioritization exercise. Following the Summit, attendees provided feedback on the final rankings. The metrics were then presented at a Town Hall style meeting for public comment. Results: Over 70 participants, representing 20 different organizations, identified 750 unique metrics from 9 domains. The prioritization process yielded 3 areas of interest, with 2 specific metrics within each: end of life and palliative care (metric 1, metric 2); adherence to best practices (metric 3, metric 4); and coordinated and efficient care (metric 5, metric 6). Follow-up surveys of Summit attendees and the Town Hall forum showed widespread support for these metrics Conclusions: Using an iterative, transparent, multi-stakeholder process, it is feasible build regional consensus around value metrics in cancer care.

Nicotine alters mucin rheological properties

Tobacco smoke exposure, the major cause of chronic obstructive pulmonary disease (COPD), instigates a dysfunctional clearance of thick obstructive mucus. However, the mechanism underlying the formation of abnormally viscous mucus remains elusive. We investigated whether nicotine can directly alter the rheological properties of mucin by examining its physicochemical interactions with human airway mucin gels secreted from A549 lung epithelial cells. Swelling kinetics and multiple particle tracking were utilized to assess mucin gel viscosity change when exposed to nicotine. Herein we show that nicotine (≤50 nM) significantly hindered postexocytotic swelling and hydration of released mucins, leading to higher viscosity, possibly by electrostatic and hydrophobic interactions. Moreover, the close association of nicotine and mucins allows airway mucus to function as a reservoir for prolonged nicotine release, leading to correlated pathogenic effects. Our results provide a novel explanation for the maltransport of poorly hydrated mucus in smokers. More importantly, this study further indicates that even low-concentration nicotine can profoundly increase mucus viscosity and thus highlights the health risks of secondhand smoke exposure.

Epilepsy and driving: potential impact of transient impaired consciousness

Driving is an important part of everyday life for most adults, and restrictions on driving can place a significant burden on individuals diagnosed with epilepsy. Although sensorimotor deficits during seizures may impair driving, decreased level of consciousness often has a more global effect on patients' ability to respond appropriately to the environment. Better understanding of the mechanisms underlying alteration of consciousness in epilepsy is important for decision-making by people with epilepsy, their physicians, and regulators in regard to the question of fitness to drive. Retrospective cohort and cross-sectional studies based on surveys or crash records can provide valuable information about driving in epilepsy. However, prospective objective testing of ictal driving ability during different types of seizures is needed to more fully understand the role of impaired consciousness and other deficits in disrupting driving. Driving simulators adapted for use in the epilepsy video-EEG monitoring unit may be well suited to provide both ictal and interictal data in patients with epilepsy. Objective information about impaired driving in specific types of epilepsy and seizures can provide better informed recommendations regarding fitness to drive, potentially improving the quality of life of people living with epilepsy.

Stakeholder-informed “Choosing Wisely” implementation project in regional oncology clinics

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Background: ASCO launched the Choosing Wisely campaign to reduce the use of interventions that lack evidence for their use in clinical cancer care. The recommendations have strong support, but lack an implementation plan. The objective of this project is to develop a stakeholder-informed process to improve adherence to ASCO Choosing Wisely within an experimental context. Methods: Participants include Medical Directors from 7 oncology clinics and 1 commercial insurer within the Puget Sound region, and the SEER Puget Sound Cancer Registry. The project consists of 3 phases (1) prioritization, (2) design, (3) implementation and monitoring. For phase 1, Medical Directors were surveyed via e-mail to prioritize the recommendations with the following criteria: importance for improving the value of cancer care; impact of adherence; urgency; and feasibility of implementing an intervention. Participants met via teleconference to discuss survey results, review regional utilization data, and design of interventions. Participants were surveyed again for a final ranking. In phase 2, participants discussed options for interventions and study designs. Results: Initially, the highest ranked recommendations were advanced imaging in staging of local stage prostate cancer, surveillance of local and regional stage breast cancer, and colony stimulating factor (CSF) use for low risk chemotherapy. After discussion, breast cancer surveillance and CSF prescribing ranked the highest. Participants requested utilization and cost-impact data from the health insurer for the top 2 choices. Conclusions: Using a transparent, multi-stakeholder process, it is feasible to implement programs to improve adherence to ASCO Choosing Wisely.

Knowledge and attitudes about hepatitis C virus (HCV) infection and its treatment in HCV mono-infected and HCV/HIV co-infected adults

Hepatitis C virus (HCV) treatment is rapidly changing but little is known about patients' attitudes and knowledge about HCV. This study used a cross-sectional survey to examine the relationship between HCV knowledge and attitudes towards HCV in patients with HCV mono-infection and HIV/HCV co-infection. Subsequently, an education intervention was developed with an abridged version of the cross-sectional survey administered before and after the education session to assess changes in knowledge and attitudes. 292 people participated in the cross-sectional survey, and 87 people participated in the education intervention. In the cross-sectional survey, the mean knowledge score regarding HCV was low (<50% of the total possible score). Mono-infected and co-infected individuals shared similar knowledge deficits and attitudes towards HCV despite having distinct demographic differences. Attitudes endorsed by patients included the following: 57% feared the consequences of HCV on their life, 37% felt HCV was not fatal, 27% did not believe they needed HCV medication, 21% felt ashamed of having HCV and 16% felt HCV treatment was not important. Attitudes that reflected indifference and shame towards HCV were associated with lower knowledge scores (HCV knowledge score of 15.1 vs. 17.5, P < 0.01 for indifference and 15.3 vs. 17.2 for shame, P = 0.02). The education intervention improved knowledge scores but did not modify the assessed attitudes. Intervention studies are needed to effectively change attitudes towards HCV infection and treatment.

Prediction of remission and recovery in young people presenting with first-episode psychosis in Hong Kong: a 3-year follow-up study

OBJECTIVE

The aim of the current study was to investigate the rates and predictors of symptomatic remission and recovery in patients presenting with first-episode psychosis 3 years after treatment initiation.

METHODS

Seven hundred participants aged 15-25 years consecutively enrolled in a territory-wide early intervention programme in Hong Kong from July 2001 to August 2003 fulfilled study inclusion criteria, with 539 completing 3-year follow-up. Baseline and follow-up variables were collected via systematic medical file review. The operational criteria for recovery were based on clinical definition incorporating both symptom and functional dimensions.

RESULTS

By the end of 3-year follow-up, 58.8% (n = 317) and 17.4% (n = 94) of participants met criteria for symptomatic remission and recovery, respectively. Around half (51.2%, n = 276) were not remitted either symptomatically or functionally in the last 12 months of follow-up. Of those who achieved sustained symptomatic remission, only 43.1% were also in functional remission. Patients in symptomatic remission had lower rate of admissions, shorter duration of hospitalisations and more favourable psychosocial functioning than non-remitted counterparts. Logistic regression analysis revealed that female sex, older age of onset of psychosis, shorter duration of untreated psychosis (DUP) and early symptom resolution predicted symptomatic remission at the end of follow-up. Higher educational attainment, superior baseline occupational status and shorter DUP were found to be predictive of recovery.

CONCLUSION

In a large representative cohort of Chinese young people presenting with first-episode psychosis, although more than half achieved symptomatic remission 3 years after service entry, the rates of functional remission and recovery were low. More intensive psychosocial interventions may be required to further improve patients' functional outcome.

A mixture of anatase and rutile TiO₂ nanoparticles induces histamine secretion in mast cells

Background

Histamine released from mast cells, through complex interactions involving the binding of IgE to FcεRI receptors and the subsequent intracellular Ca²⁺ signaling, can mediate many allergic/inflammatory responses. The possibility of titanium dioxide nanoparticles (TiO₂ NPs), a nanomaterial pervasively used in nanotechnology and pharmaceutical industries, to directly induce histamine secretion without prior allergen sensitization has remained uncertain.

Results

TiO₂ NP exposure increased both histamine secretion and cytosolic Ca²⁺ concentration ([Ca²⁺]_C) in a dose dependent manner in rat RBL-2H3 mast cells. The increase in intracellular Ca²⁺ levels resulted primarily from an extracellular Ca²⁺ influx via membrane L-type Ca²⁺ channels. Unspecific Ca²⁺ entry via TiO₂ NP-instigated membrane disruption was demonstrated with the intracellular leakage of a fluorescent calcein dye. Oxidative stress induced by TiO₂ NPs also contributed to cytosolic Ca²⁺ signaling. The PLC-IP₃-IP₃ receptor pathways and endoplasmic reticulum (ER) were responsible for the sustained elevation of [Ca²⁺]_C and histamine secretion.

Conclusion

Our data suggests that systemic circulation of NPs may prompt histamine release at different locales causing abnormal inflammatory diseases. This study provides a novel mechanistic link between environmental TiO₂ NP exposure and allergen-independent histamine release that can exacerbate manifestations of multiple allergic responses.

Functionalized carboxyl nanoparticles enhance mucus dispersion and hydration

Luminal accumulation of viscous, poorly hydrated, and less transportable mucus has been associated with altered mucus rheology and reduced mucociliary clearance. These symptoms are some of the cardinal clinical manifestations found throughout major respiratory diseases as well as gastrointestinal and digestive disorders. Applications of current mucolytics may yield short-term improvements but are continuously challenged by undesirable side-effects. While nanoparticles (NPs) can interact with mucin polymers,whether functionalized NPs can rectify mucus rheology is unknown. Herein, we report that carboxyl-functionalized NPs (24 nm and 120 nm) dramatically reduced mucin gel size and accelerated mucin matrix hydration rate (diffusivity). Our results suggest that carboxyl-functionalized NPs disperse mucin gels possibly by enhancing network hydration. This report highlights the prospective usages of carboxyl-functionalized NPs as a novel mucus dispersant or mucolytic agent in adjusting mucus rheological properties and improving mucociliary transport to relieve clinical symptoms of patients suffering from relevant diseases.

Prenatal exposure to MDMA alters noradrenergic neurodevelopment in the rat

3,4-methylenedioxymethamphetamine (MDMA; ecstasy) binds with high affinity to the norepinephrine transporter (NET), making the noradrenergic system a potential target during fetal exposure. Recent data indicate that adult rats that had been prenatally exposed to MDMA display persistent deficits in working memory and attention; behaviors consistent with abnormal noradrenergic signaling in the forebrain. The present study was designed to investigate whether prenatal exposure to MDMA from embryonic days 14-20 affects the structure and/or function of the noradrenergic system of the rat on postnatal day 21. Offspring that were prenatally exposed to MDMA exhibited an increase in noradrenergic fiber density in the prelimbic region of the prefrontal cortex and the CA1 region of the hippocampus that was not accompanied by an increase in the number of noradrenergic neurons in the locus coeruleus. Direct tissue autoradiography using tritiated nisoxetine demonstrated that while NET binding was not altered in the prelimbic cortex, the dentate gyrus, or the locus coeruleus, it was increased in the CA1, CA2, and CA3 regions of the hippocampus. Basal levels of norepinephrine were increased in the prefrontal cortex and the nucleus accumbens of MDMA-exposed rats, as compared to saline-treated controls. These findings indicate that prenatal exposure to MDMA results in structural changes in the noradrenergic system as well as functional alterations in NE neurotransmission in structures that are critical in attentional processing.

Gender differences in reward-related decision processing under stress

Recent research indicates gender differences in the impact of stress on decision behavior, but little is known about the brain mechanisms involved in these gender-specific stress effects. The current study used functional magnetic resonance imaging (fMRI) to determine whether induced stress resulted in gender-specific patterns of brain activation during a decision task involving monetary reward. Specifically, we manipulated physiological stress levels using a cold pressor task, prior to a risky decision making task. Healthy men (n = 24, 12 stressed) and women (n = 23, 11 stressed) completed the decision task after either cold pressor stress or a control task during the period of cortisol response to the cold pressor. Gender differences in behavior were present in stressed participants but not controls, such that stress led to greater reward collection and faster decision speed in males but less reward collection and slower decision speed in females. A gender-by-stress interaction was observed for the dorsal striatum and anterior insula. With cold stress, activation in these regions was increased in males but decreased in females. The findings of this study indicate that the impact of stress on reward-related decision processing differs depending on gender.

No association between T102C polymorphism of serotonin-2A receptor gene and clinical phenotypes of Chinese schizophrenic patients

Serotonin dysfunction has been implicated in the pathogenesis of schizophrenia. Previous studies have shown an association between the T102C polymorphism of the 5HT2a receptor gene and schizophrenia. However, negative findings have also been reported. One possible explanation for such discrepancy is disease heterogeneity due to the current limitations in the diagnosis of schizophrenia. We conducted a case-control study of the T102C polymorphism with detailed characterisation of the clinical phenotypes to investigate the possible association with schizophrenia not only at the diagnostic level, but also with reference to other clinical phenotypes potentially related to serotonin dysfunction. Four hundred and seventy-one biologically unrelated schizophrenic patients and 523 unrelated healthy controls of Han Chinese descent in Hong Kong were compared for genotypes and allele frequencies of the T102C polymorphism by PCR amplification and restriction analysis. No evidence of association was detected at the diagnostic level and various clinical phenotypes. However, we found a trend association with small effect size between genotype 102T/102C and patients with better verbal fluency and less motor co-ordination soft neurological signs. There is a need for future large-scale studies on the possible associations between genetic polymorphisms and neurocognitive function impairments in schizophrenia.

[N-[dimethyl(eta5-2,3,4,6-tetramethylindenyl)silyl]cyclobutylamido-kappaN](eta4-1,4-diphenyl-1,3-buta-diene)titanium(II)

The titanium metal center in the title compound, [Ti(C19H27NSi)(C16H14)], is coordinated in a distorted tetrahedral geometry by a eta5-indenyl ligand, a dimethylsilyl-bridged N-cyclobutylamido ligand and an s-cis-eta4-1,4-diphenyl-1,3-butadiene ligand in a 'prone' pi-fashion, revealing a formal divalent Ti center.

Neurological signs and sustained attention impairment in schizophrenia

Both neurological signs and attention impairments are often found in schizophrenia. This study addresses the extent to which neurological signs are related to sustained attention impairment. We assessed subgroups of neurological signs using the standardised Cambridge Neurological Inventory (CNI). Sustained attention was measured using a monotone counting paradigm. After taking into consideration potential confounds such as age, education level and duration of illness, we explored the correlation between sustained attention and groups of neurological signs, as well as with individual signs. We found that "motor coordination" and "disinhibition" signs were significantly related to sustained attention. The correlation with "sensory integration" just failed to reach significance after correction for multiple comparison. "Dyskinesia", "catatonia", "pyramidal" and "extrapyramidal" subgroups were unrelated to sustained attention. The results support the notion of heterogeneity and diversity in neurological signs (even among soft neurological signs) and argue against the use of a single global measure to embrace all soft neurological signs in schizophrenia.

Early degenerative changes in transgenic mice expressing mutant huntingtin involve dendritic abnormalities but no impairment of mitochondrial energy production

Mitochondrial defects, which occur in the brain of late-stage Huntington's disease (HD) patients, have been proposed to underlie the selective neuronal loss in the disease. To shed light on the possible role of mitochondrial energy impairment in the early phases of HD pathophysiology, we carried out Golgi impregnation and quantitative histochemical/biochemical studies in HD full-length cDNA transgenic mice that were symptomatic but had not developed to a stage in which neuronal loss could be documented. Golgi staining showed morphologic abnormalities that included a significant decrease in the number of dendritic spines and a thickening of proximal dendrites in striatal and cortical neurons. In contrast, measurements of mitochondrial electron transport Complexes I-IV did not reveal changes in the striatum and cerebral cortex in these mice. Examination of the neostriatum and cerebral cortex in human presymptomatic and pathological Grade 1 HD cases also showed no change in the activity of mitochondrial Complexes I-IV. These data suggest that dendritic alterations precede irreversible cell loss in HD, and that mitochondrial energy impairment is a consequence, rather than a cause, of early neuropathological changes.

Hypoxia activates a platelet-derived growth factor receptor/phosphatidylinositol 3-kinase/Akt pathway that results in glycogen synthase kinase-3 inactivation

Hypoxia initiates numerous intracellular signaling pathways important in regulating cell proliferation, differentiation, and death. In this study, we investigated the pathway that hypoxia uses to activate Akt and inactivate glycogen synthase kinase-3 (GSK-3), two proteins the functions of which are important in cell survival and energy metabolism. Severe hypoxia (0.01% oxygen) initiated a signaling cascade by inducing the tyrosine phosphorylation of the platelet-derived growth factor (PDGF) receptor within 1 h of treatment and increasing receptor association with the p85 subunit of phosphatidylinositol 3-kinase (PI 3-K). Hypoxia-induced signaling also resulted in PI 3-K-dependent phosphorylation of Akt on Ser-473, a modification of Akt that is important for its activation. This activation of Akt by hypoxia was substantially diminished in cells that possessed mutations in their PDGF receptor-PI 3-K interaction domain. In addition, Akt activation by hypoxia was resistant to treatment with the growth factor receptor poison suramin but was sensitive to treatment with the PI 3-K inhibitor wortmannin. Activation of Akt by hypoxia resulted in the phosphorylation of GSK-3alpha and GSK-3beta at Ser-9 and Ser-21, two well-documented Akt phosphorylation sites, respectively, that are inactivating modifications of each GSK-3 isoform. In support of the phosphorylation data, GSK-3 activity was significantly reduced under hypoxia. In conclusion, we propose that hypoxia activates a growth factor receptor/PI 3-K/Akt cascade that leads to GSK-3 inactivation, a pathway that can impact cell survival, proliferation, and metabolism.

Stroop interference and facilitation effects in first-episode schizophrenic patients

In the Stroop test, interference occurs in naming the print color of a word when the word is itself the name of another color. Facilitation occurs when the word is the same as the print color. Previous studies on selective attention in schizophrenia using the Stroop interference effects have yielded contradicting results. Constraints included limited sample size and the recruitment of medicated chronic patients. We studied the Stroop interference and facilitation effects in a relatively large sample of first-episode schizophrenic patients (n=56), a substantial proportion of whom were medication-naïve (n=30) at the time of initial testing. We have also carried out longitudinal follow-up assessments when patients reached a clinically stable state, as well as 4months after recovery from the episode. We found that the Stroop interference effect was not increased in first-episode schizophrenic patients, whether medication-naïve or not. This effect did not change over the follow-up period. In addition, we detected an increase in Stroop facilitation effect in medicated schizophrenic patients, but only in the initial assessment soon after they had received medication. After sustained treatment, the increase in facilitation was normalized. These observations supported previous findings of a normal Stroop interference effect amongst schizophrenic patients. The increased facilitation effect for patients in their early phase of treatment (but not later) may represent an acute effect of anti-psychotic medication. Its nature and significance require further investigation.

Insight changes in acute psychotic episodes: a prospective study of Hong Kong Chinese patients

Insight impairment occurs commonly in psychotic disorders (including mood episodes with psychotic symptoms). The aim of the present study is to measure changes of insight over the course of a psychotic episode and to investigate its relationships with symptoms and neurocognitive functions, as well as psychosocial factors. Insight was assessed at weekly intervals in 80 consecutive inpatients presenting with a psychotic episode by using a Chinese translation of the Scale to Assess Unawareness of Mental Disorder (SUMD). The relationships between insight change and other variables were explored. Modest but significant changes in insight were found in both directions with clinical resolution of psychotic symptoms. In particular, insight "declined" as symptoms improved in a number of patients. In addition, changes in insight score correlated with changes in Wisconsin Card Sorting Test (WCST) performance. More changes in insight (in either direction) tended to occur in younger patients. These results indicated that adequate control of psychotic symptoms and improvement in neuropsychological functioning might be associated with better insight recovery.

University students' attitudes towards mental patients and psychiatric treatment

BACKGROUND

Public attitudes towards mental patients and psychiatric treatment are mostly unfavorable. Mental patients tend to conceal their illness or selectively disclose their treatment histories to someone they trust.

AIMS

To examine the university students' attitudes towards different information regarding a person labeled as mentally ill.

METHODS

We designed seven descriptions of a mentally ill person of varying past and current treatment histories and randomly assigned 308 university undergraduates to read one of the descriptions. Subjects rated their willingness to interact with the hypothetical case using a 19-item social distance scale.

RESULTS

Greater social distance was associated with non-medical field of study, no previous contact with the mentally ill and female gender. Subjects without previous contact with mentally ill individuals kept greater distance from a discharged mental patient receiving psychiatric care than a mental patient who did not require medications nor psychiatric follow-up. In contrast, respondents who had previous contact with the mentally ill were more willing to interact with a discharged mental patient receiving psychiatric care comparing with a person labeled as mentally ill alone and a mental patient who had never been admitted to hospital.

CONCLUSIONS

Implications of our findings in clinical management and designing stigma-reducing programme are discussed.

B2 bradykinin receptor immunoreactivity in rat brain

Bradykinin has long been known to exist in the central nervous system and has been hypothesized to mediate specific functions. Despite an increasing understanding of the functions of bradykinin, little is known about the cell types expressing the bradykinin receptor within the brain. The present investigation employed a monoclonal antibody directed against the 15-amino-acid portion of the C-terminal of the human bradykinin B2 receptor to establish the cellular distribution of bradykinin B2 receptor immunoreactivity in the rat brain. Bradykinin B2 receptor immunoreactivity was ubiquitously and selectively observed in neurons, including those within the olfactory bulb, cerebral cortex, hippocampus, basal forebrain, basal ganglia, thalamus, hypothalamus, cerebellum, and brainstem nuclei. Bradykinin B2 receptor immunoreactivity was also present in the circumventricular organs including choroid plexus, subfornical organ, median eminence, and area postrema. Double-labeling experiments colocalizing the bradykinin B2 receptor with the neuronal marker NeuN or the astrocytic marker glial fibrillary acidic protein revealed that virtually 100% of the bradykinin B2 receptor-immunoreactive positive cells were neurons. The widespread distribution of bradykinin B2 receptor immunoreactivity in neuronal compartments suggests a greater than previously appreciated role for this peptide in neuronal function.

Progressive deterioration of soft neurological signs in chronic schizophrenic patients

OBJECTIVE

Neurological signs are found to be increased in schizophrenia in cross-sectional studies. Whether they progress with time is an important issue in addressing the course of the illness.

METHOD

The current study investigated different groups of neurological signs in 43 stable chronic schizophrenic patients over a 3-year period using an operationalized instrument.

RESULTS

While symptoms and medication have remained largely unchanged in the 3-year period, significant increase in soft neurological signs (SNS) ('motor coordination', 'sensory integration' and 'disinhibition') has been observed. This contrasted with the stability of 'pyramidal', 'extrapyramidal', 'dyskinesia' and 'catatonia' signs. The increase in SNS appears not to be related to age, illness duration, symptoms or medication.

CONCLUSION

This finding suggests that SNS represent a marker sensitive to a possible late deterioration process in the course of a schizophrenic illness.

Age-related decreases in GTP-cyclohydrolase-I immunoreactive neurons in the monkey and human substantia nigra

Guanosine triphosphate cyclohydrolase I (GTPCHI) is a critical enzyme in catecholamine function and is rate limiting for the synthesis of the catecholamine co-factor tetrahydrobiopterin. The present study assessed the distribution of GTPCHI immunoreactivity (-ir) within the monkey and human ventral midbrain and determined whether its expression is altered as a function of age. Light and confocal microscopic analyses revealed that young monkeys and humans displayed GTPCHI-ir within melanin-containing and tyrosine-hydroxylase-ir neurons in primate substantia nigra. Stereological counts revealed that there was a 67.4% reduction in GTPCHI-ir neuronal number, a 63.5% reduction in GTPCHI-ir neuronal density, and a 37.6% reduction in neuronal volume in aged monkeys relative to young cohorts. Similar age-related changes were seen in humans, in whom there were significant reductions in the number of GTPCHI-ir nigral neurons in middle age (58.4%) and aged (81.5%) cases relative to young cohorts. The density of GTPCHI-ir neurons within the nigra was similarly reduced in middle-aged (63.0%) and aged (81.8%) cases. In contrast to monkeys, aged humans did not display shrinkage in the volume of GTPCHI-ir nigral neurons. The presence of numerous melanin-positive, but GTPCHI-ir immunonegative, neurons in the aged monkey and human nigra indicates that these decreases represent an age-related phenotypic downregulation of this enzyme and not a loss of neurons per se. These data indicate that there is a dramatic decrease in GTPCHI-ir in nonhuman primates and humans as a function of age and that loss of this enzyme may be partly responsible for the age-related decrease in dopaminergic tone within nigrostriatal systems.

Neurodegeneration prevented by lentiviral vector delivery of GDNF in primate models of Parkinson's disease

Lentiviral delivery of glial cell line-derived neurotrophic factor (lenti-GDNF) was tested for its trophic effects upon degenerating nigrostriatal neurons in nonhuman primate models of Parkinson's disease (PD). We injected lenti-GDNF into the striatum and substantia nigra of nonlesioned aged rhesus monkeys or young adult rhesus monkeys treated 1 week prior with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). Extensive GDNF expression with anterograde and retrograde transport was seen in all animals. In aged monkeys, lenti-GDNF augmented dopaminergic function. In MPTP-treated monkeys, lenti-GDNF reversed functional deficits and completely prevented nigrostriatal degeneration. Additionally, lenti-GDNF injections to intact rhesus monkeys revealed long-term gene expression (8 months). In MPTP-treated monkeys, lenti-GDNF treatment reversed motor deficits in a hand-reach task. These data indicate that GDNF delivery using a lentiviral vector system can prevent nigrostriatal degeneration and induce regeneration in primate models of PD and might be a viable therapeutic strategy for PD patients.

The complete sequence of the mucosal pathogen Ureaplasma urealyticum

The comparison of the genomes of two very closely related human mucosal pathogens, Mycoplasma genitalium and Mycoplasma pneumoniae, has helped define the essential functions of a self-replicating minimal cell, as well as what constitutes a mycoplasma. Here we report the complete sequence of a more distant phylogenetic relative of those bacteria, Ureaplasma urealyticum (parvum biovar), which is also a mucosal pathogen of humans. It is the third mycoplasma to be sequenced, and has the smallest sequenced prokaryotic genome except for M. genitalium. Although the U. urealyticum genome is similar to the two sequenced mycoplasma genomes, features make this organism unique among mycoplasmas and all bacteria. Almost all ATP synthesis is the result of urea hydrolysis, which generates an energy-producing electrochemical gradient. Some highly conserved eubacterial enzymes appear not to be encoded by U. urealyticum, including the cell-division protein FtsZ, chaperonins GroES and GroEL, and ribonucleoside-diphosphate reductase. U. urealyticum has six closely related iron transporters, which apparently arose through gene duplication, suggesting that it has a kind of respiration system not present in other small genome bacteria The genome is only 25.5% G+C in nucleotide content, and the G+C content of individual genes may predict how essential those genes are to ureaplasma survival.

Pramipexole attenuates the dopaminergic cell loss induced by intraventricular 6-hydroxydopamine

The D3 preferring dopamine agonist pramipexole has been shown to attenuate the cell loss induced by levodopa in vitro. Pramipexole was herein evaluated in the 6-hydroxydopamine lesion model to determine its in vivo effect. Rats were treated with pramipexole or saline before and after an intracerebroventricular 6-hydroxydopamine injection. In the preliminary study, 6-hydroxydopamine produced a 68% reduction in striatal dopamine and a 62% loss in tyrosine hydroxylase immunoreactive (THir) cell counts in the substantia nigra. Pramipexole treated animals exhibited a 29% and a 27% reduction in striatal dopamine and THir cell counts, respectively. THir cell counts and striatal dopamine were significantly correlated. In the stereological study, 6-hydroxydopamine reduced THir cell counts by 47% in saline treated animals and 26% in pramipexole treated animals. These data demonstrate that pramipexole attenuates the biochemical and THir cell changes normally produced by 6-hydroxydopamine consistent with its neuroprotective actions in vitro.

PLAC1, an Xq26 gene with placenta-specific expression

A novel human X-linked gene shows placenta-specific expression and has been named PLAC1. The gene maps 65 kb telomeric to HPRT at Xq26 and has been completely sequenced at the cDNA and genomic levels. The mouse orthologue Plac1 maps to the syntenically equivalent region of the mouse X chromosome. In situ hybridization studies with the antisense mRNA during mouse embryogenesis detect Plac1 expression from 7.5 dpc (days postcoitum) to 14.5 dpc in ectoplacental cone, giant cells, and labyrinthine trophoblasts. The putative human and murine PLAC1 proteins are 60% identical and 77% homologous. Both include a signal peptide and a peptide sequence also found in an interaction domain of the ZP3 (zona pellucida 3) protein. These results make PLAC1 a marker for placental development, with a possible role in the establishment of the mother-fetus interface.

Opposing effects of hypoxia on expression of the angiogenic inhibitor thrombospondin 1 and the angiogenic inducer vascular endothelial growth factor

Tumor angiogenesis, the development of new blood vessels during malignant progression, is a regulated process that has both genetic and physiological controls. Physiologically, angiogenesis is stimulated by decreases in tissue oxygenation (i.e., hypoxia). We investigated the effect of hypoxia on the expression of two angiogenic factors reported to be genetically regulated by the p53 tumor suppressor gene: (a) the angiogenic inhibitor thrombospondin 1 (TSP-1); and (b) the angiogenic inducer vascular endothelial growth factor (VEGF). Analysis of rodent cells that differ in their p53 genotype (p53+/+ or p53-/-) indicated that in vitro exposure to hypoxia simultaneously suppressed TSP-1 and induced VEGF expression, regardless of the p53 genotype. On transformation of these cells with E1A and oncogenic H-ras, the basal level of TSP-1 expression was strongly diminished, whereas that of VEGF could still be induced by hypoxia. Consistent with these in vitro findings, sections of tumors derived from the transformed p53+/+ and p53-/- cells showed that VEGF protein overlapped with regions of hypoxia, whereas TSP-1 protein was below the limits of detection in tumor tissue. Using a panel of normal/immortalized and transformed human cells, it was found that the ability of hypoxia to inhibit TSP-1 expression depends on the cell type and/or the degree of transformation. In contrast, VEGF expression was induced by hypoxia in all of the human cell types examined. Together, these findings suggest that hypoxic and oncogenic signals could interact in the tumor microenvironment to inhibit TSP-1 and induce VEGF expression, promoting the switch to the angiogenic phenotype.

[Property of compliance and change of structural components in anastomosed artery]

OBJECTIVE

To explore the relationship between the properties of compliance and the change of structure of components in anastomosed arteries.

METHODS

The arterial pressure and diameter of femoral arteries of dogs were measured in vivo before and after arterial anastomosis in different time intervals to deduce the arterial compliance. The anastomosed arteries were removed and evaluated through light microscopic examination and various staining methods, the relative contents of elastin, collagen and smooth muscles were measured through image analysis system.

RESULTS

The compliance of arteries was gradually decreased after anastomosis with peak-time on the 14th day. The content of elastin at different time had no significant difference, while the content of collagen increased gradually, the ratio of them was increased.

CONCLUSION

The property of compliance of anastomosed arteries is closely related to the contents of the structural components.