Quasiparticle Poisoning of Superconducting Qubits from Resonant Absorption of Pair-Breaking Photons

The ideal superconductor provides a pristine environment for the delicate states of a quantum computer: because there is an energy gap to excitations, there are no spurious modes with which the qubits can interact, causing irreversible decay of the quantum state. As a practical matter, however, there exists a high density of excitations out of the superconducting ground state even at ultralow temperature; these are known as quasiparticles. Observed quasiparticle densities are of order 1  μm^{-3}, tens of orders of magnitude greater than the equilibrium density expected from theory. Nonequilibrium quasiparticles extract energy from the qubit mode and can induce dephasing. Here we show that a dominant mechanism for quasiparticle poisoning is direct absorption of high-energy photons at the qubit junction. We use a Josephson junction-based photon source to controllably dose qubit circuits with millimeter-wave radiation, and we use an interferometric quantum gate sequence to reconstruct the charge parity of the qubit. We find that the structure of the qubit itself acts as a resonant antenna for millimeter-wave radiation, providing an efficient path for photons to generate quasiparticles. A deep understanding of this physics will pave the way to realization of next-generation superconducting qubits that are robust against quasiparticle poisoning.

Oral Cavity Squamous Cell Carcinomas in Patients with a History of Oral Lichen Planus: Frequency and Outcomes

PURPOSE/OBJECTIVE(S)

Oral lichen planus (OLP) is an inflammatory condition which affects the mucous membranes of the oral cavity. While previous studies have described the association between OLP and development of oral cavity cancer, there is currently a paucity of literature examining the impact of this disease on treatment response and prognosis. As such, we present a retrospective cohort study of Oral cavity squamous cell carcinoma (OCSCC) patients with a history of OLP to explore the course of their disease.

MATERIALS/METHODS

Using an IRB approved tertiary care registry of head and neck cancer patients, we identified patients with OCSCC who had a prior diagnosis of OLP. The number of new primary tumors, rates of local (LF), regional (RF) and distant failure (DF), as well as overall survival (OS) were assessed using Cox proportional hazards and Kaplan Meier analysis for actuarial survival estimates.

RESULTS

Fifty-four patients with OCSCC and OLP were identified with 109 individual OCSCC diagnoses. Patients had a median age of 67 years, were predominantly female (n = 42, 77.8%) and never smokers (n = 29, 53.7%) with a median follow up after diagnosis of OCSCC of 46.5 months. Nine patients (16.7%) had a history of immunosuppression of whom 6 (11.1%) had chronic steroid use for treatment of OLP. Within the cohort, 33 (61.1%) of OLP patients had a single OCSCC, 11 (20.4%) had 2, and 10 (18.5%) had >3 separate tumors develop. The most common oral cavity subsites were oral tongue (n = 42, 38.5%), followed by alveolar ridge (n = 14, 12.8%) and gingiva (n = 13, 11.9%). Papillary SCC subtype was identified in 10.1%. 92.7% of tumors (n = 101) were treated with primary surgery, with 23 (21.1%) receiving adjuvant RT and 10 of those patients receiving concurrent chemotherapy. Among resected patients, pathologic stages were predominantly T1-2 (84.1%) and N0 (50% vs N1 15.6% and N2a-3 34.4%). The mean RT dose was 62 Gy in 32 fractions. Locoregional failure occurred in 24.8% of cancers (n = 27), with local and regional failure occurring in 13.8% (n = 15) and 11% (n = 12) of lesions, respectively. Recurrence free survival at 3 and 5 years was 75% and 70.3%, respectively, with overall survival at 3 and 5 years of 71.1% and 67%, respectively.

CONCLUSION

Patients with OCSCC and a history of OLP are predominantly female and never smokers. The tumors that develop in such patients are often early stage but a proportion of patients appear to be at higher risk of developing multiple malignancies and surveillance of this patient population to identify new tumors is crucial.

Definitive Radiotherapy for the Treatment of Gross Disease in Unresected Differentiated Thyroid Cancer

PURPOSE/OBJECTIVE(S)

While surgery (with or without radioactive iodine (RAI)) is the mainstay of locoregional control in differentiated thyroid cancer (DTC), patients with unresectable disease present a clinical challenge. Uncontrolled disease in the neck can lead to substantial morbidity and mortality in DTC and obtaining locoregional control is vital to preserving quality of life and longevity. High dose definitive radiotherapy (RT) for gross disease in DTC is understudied. This study examines the efficacy of definitive RT in this setting.

MATERIALS/METHODS

From an IRB-approved registry of head and neck cancer cases treated at a tertiary care center over a period of 8 years (2014-2022), patients with incompletely resected or unresectable DTC including papillary, follicular, mixed, medullary, and poorly differentiated types were identified. All patients were treated to the neck and/or thyroid regions with visible gross disease to a definitive dose of radiation. The primary endpoint was local control within the radiated portal with a secondary endpoint of locoregional control within the neck.

RESULTS

A total of 31 patients were identified, of whom 74.2% were Caucasian. Fourteen were female (45.2%), and 17 (54.8%) were male. The median age was 68 years (range 26-90) and the median follow-up was 31 months. Histologically, 19 (61.3%) cases were papillary, 4 (12.9%) were follicular, 2 (6.5%) were mixed, 3 (9.7%) were medullary, and 3 (9.7%) were poorly differentiated. Among patients with non-medullary DTC 18 (69.2%) received prior RAI. Twelve patients were treated with radiation at initial diagnosis, while 19 patients were treated at the time of recurrence; two patients received concurrent chemotherapy. Twenty-eight patients (90.3%) were treated with IMRT and 3 (9.7%) were treated with SBRT. The median dose to the gross disease was 66 Gy (range 30-70.4) in 32 fractions (range 5-35). Overall, 5 patients (16.1%) experienced a locoregional failure after RT and all experienced failure in the RT portal. The actuarial infield control/locoregional control of radiation therapy at 3 and 5 years was 84.8% and 74.2%, respectively. Overall survival at 3 and 5 years was 68.5% and 47.4%, respectively. Among patients who had a locoregional failure after RT, 2 patients were salvaged with systemic therapy, 2 patients with surgery, and 1 patient with SBRT re-irradiation (40 Gy/5 fractions). The patient salvaged with SBRT remains without disease 8 months post-RT.

CONCLUSION

Definitive radiotherapy is a highly effective strategy to obtain durable control of unresected DTC. It should be standard for unresected disease and considered as a viable alternative for patients with borderline resectable disease for whom resection would be highly morbid.

Evaluation of Genotoxicity of SU-Eohyeol Pharmacopuncture Using an In Vitro Chromosome Aberration Test in Chinese Hamster Lung Cell

Objectives

This study was conducted to evaluate the safety of SU-Eohyeol pharmacopuncture (SUEP) by assessing its potential to cause chromosomal abnormalities in Chinese hamster lung cells (CHL/IC).

Methods

A dose-curve was conducted to determine the highest dose of SUEP. Doses of 10, 5, 2.5, 1.25, 0.625, and 0.313% were used, and no cytotoxicity or SUEP precipitation was observed. SUEP doses of 10, 5, and 2.5%, with positive and negative controls, were used in a chromosome aberration test.

Results

In this study, the frequency of abnormal chromosomal cells in the SUEP group did not show a statistically significant difference from that of the negative control group in short-term treatments with and without metabolic activation and the continuous treatment without metabolic activation. Compared with the negative control group, the positive control group had a significantly higher frequency of cells with structural chromosomal abnormalities. This test's results satisfied all conditions for determining the results.

Conclusion

SUEP did not induce chromosomal aberrations under the conditions of this study. Other toxicity evaluations, safety studies in humans, and various clinical trials are required to evaluate the safety and efficacy of SUEP.

Single-Dose Intramuscular Toxicity Study of SU-Eohyeol Pharmacopuncture in Rats

Objectives

This toxicological study was performed to assess for potential toxicity and to determine the approximate lethal dose of SU-Eohyeol pharmacopuncture (SUEP) following a single intramuscular injection of SUEP into male and female Sprague-Dawley (SD) rats.

Methods

The groups in our experiment consisted of an experimental group treated with SUEP at a dose of 1.0 mL/animal and a control group injected with a normal saline solution, and five male and female rats were placed in each group. Each animal was administered a single intramuscular injection. We monitored all rats for clinical signs and body weight changes for 14 days after administration. At the end of the observation period, the rats were euthanized and autopsied, and localized tolerance examinations were conducted at the site of administration of the test substance.

Results

There were no deaths in either sex in the SUEP-treated group. There was no significant difference between the SUEP-treated group and the control group in the clinical signs and weight changes among the rats. In addition, no significant SUEP-related changes were observed on autopsy findings or local tolerance examinations at the injection site by histopathological examination.

Conclusion

Our results suggest that the approximate lethal dose of a single intramuscular administration of SUEP in female and male rats under the conditions of this study is greater than 1.0 mL/animal. To determine the safety of the use of SUEP in Korean medical clinical practice, additional toxicity studies will be needed.

P02.01.B The telomere maintenance mechanism spectrum and its dynamics in gliomas

The activation of the telomere maintenance mechanism (TMM) is one of the critical drivers of cancer cell immortality. In gliomas, TERT expression and TERT promoter mutation are considered to reliably indicate telomerase activation, while ATRX mutation indicates alternative lengthening of telomeres (ALT). However, these relationships have not been extensively validated in tumor tissues. Here, we show through the direct measurement of telomerase activity and ALT in a large set of glioma samples that the TMM in glioma cannot be defined in the dichotomy of telomerase activity and ALT, regardless of TERT expression, TERT promoter mutation and ATRX mutation. Moreover, we observed that a considerable proportion of gliomas lack both telomerase activity and ALT (Neither group). And this Neither group exhibited evidence of slow growth potential. From a set of longitudinal samples from a separate cohort of glioma patients, we discovered that the TMM is not fixed but changes with glioma progression. Collectively, these results suggest that the TMM is a dynamic entity and that reflects the plasticity of the oncogenic biological status of tumor cells and that the TMM should be defined by the direct measurement of telomerase enzyme activity and evidence of ALT.

A Single-Center Retrospective Study on the Effects of Korean Medicine in 342 Traffic Accident Cases

Objectives

In South Korea, traffic accident victims can be treated under automobile insurance coverage. Korean medicine (KM) clinics have reported the largest number of automobile insurance fee claims among medical institutions. This study investigated the status of the KM automobile insurance system in a single KM clinic.

Methods

We retrospectively surveyed the medical charts of 342 traffic accident patients treated at the Jisung KM clinic between January 2009 and June 2017.

Results

Most of the patients were men and in their 30s. The most common method of locating the clinic was an internet search. The most common traffic accident type was collision between vehicles (83.63%), with 70.76% of patients visiting during the most acute phase. The major disease codes included S434, M4836, F072, S0600, and S3350. The most frequent treatment period was within 1 month of the accident, and most patients received 10 or fewer treatments. The mean treatment duration and number of treatments were 37.68 ± 45.11 days and 11.68 ± 10.63 treatments, respectively. The initial pain numerical rating scale (NRS), 7.32 ± 0.96, decreased to 3.57 ± 1.40 at the end of treatment, with a symptom improvement score of 1.87 ± 0.60. Regarding sex, age, disease duration, location at the time of the accident, presence of additional and psychological symptoms, and chuna, there were statistically significant differences in treatment duration and number of treatments. A higher number of treatments and the longer treatment duration was associated with a higher initial NRS, lower post-treatment NRS, and better improvement score. Since the introduction of traffic accident (TA) pharmacopuncture, the rate of use of a single type of pharmacopuncture increased; however, no significant differences in treatment duration and number, NRS before and after treatment, and improvement score were observed between treatment groups before and after TA pharmacopuncture. No adverse reactions were observed for any treatment.

Conclusion

This study confirmed the previous findings of a high treatment effect of KM under automobile insurance. We also observed significant correlations based on a detailed medical status, which may explain the increasing use of KM in the automobile insurance system. Additional multi-center studies in different regions are needed.

Genotoxicity Evaluation of Capsaicin-Containing (CP) Pharmacopuncture, in an In Vivo Micronucleus Test

Objectives

Capsaicin-containing (CP) pharmacopuncture was developed to treat neuropathic pain. This study was conducted to assess the toxicity of CP extract for pharmacopuncture, using a micronucleus test.

Methods

First, a dose range finding study was conducted. Then an in vivo micronucleus test was performed to determine the induction of micronuclei in mouse bone marrow cells after intramuscular administration of CP twice with a 24-hour interval to 8-week-old ICR mice. A high dose of 0.2 mL/animal was selected, and this was sequentially diluted by applying a geometric ratio of 2 to produce two lower dose levels (0.1 and 0.05 mL/animal). In addition, negative and positive control groups were set up, and an HPLC analysis was conducted to confirm the capsaicin content of CP.

Results

The incidence of micro-nucleated polychromatic erythrocytes in polychromatic erythrocytes in the CP-treated group was similar to that in the negative-control group, while that in the positive-control group was significantly greater. In addition, the ratio of polychromatic erythrocytes to total erythrocytes in the CP treatment group and the positive control group was not significantly different from the negative control group. In the HPLC analysis, capsaicin in the CP was identified through a comparison with the retention time of the capsaicin standard of 27 min.

Conclusion

CP did not show any indication of any potential to induce micronuclei formation in bone marrow cells of ICR mice under the conditions of this study. Further toxicity studies are necessary to ensure the safety of the use of CP in clinical practice.

Suppression of Unwanted ZZ Interactions in a Hybrid Two-Qubit System

Mitigating crosstalk errors, whether classical or quantum mechanical, is critically important for achieving high-fidelity entangling gates in multiqubit circuits. For weakly anharmonic superconducting qubits, unwanted ZZ interactions can be suppressed by combining qubits with opposite anharmonicity. We present experimental measurements and theoretical modeling of two-qubit gate error for gates based on the cross resonance interaction between a capacitively shunted flux qubit and a transmon, and demonstrate the elimination of the ZZ interaction.

Herbal medicine for the management of idiopathic trigeminal neuralgia: A protocol for a systematic review of controlled trials

BACKGROUND

Trigeminal neuralgia is an oral facial pain that is limited to one or more parts of the trigeminal nerve. As it becomes chronic, it can seriously affect the quality of life of most patients, and it is expected to increase in incidence in modern aging society. The objective of this systematic review protocol is to provide methods for evaluating the effectiveness and safety of herbal medicines for idiopathic trigeminal neuralgia (ITN).

METHODS

A total of 14 databases will be searched for studies uploaded from inception to the present date that investigated the treatment of ITN. These databases are MEDLINE, EMBASE, AMED, Cumulative Index to Nursing and Allied Health Literature (CINAHL), Cochrane Library, PsycARTICLES, four Korean databases, two Chinese databases, and two Japanese databases. We will include randomized controlled trials (RCTs) assessing herbal medicine decoctions used to treat any type of ITN. All RCTs of decoctions or modified decoctions with any type of form of herbal medicine will be eligible for inclusion. The methodological quality of randomized controlled trials will be analyzed using the Cochrane Collaboration tool to assess risk of bias, and the confidence in the cumulative evidence will be assessed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) instrument.

ETHICS AND DISSEMINATION

The results of this systematic review will be published in a peer-reviewed journal and disseminated electronically and in print. To inform and guide healthcare practices, the review will be updated.

TRIAL REGISTRATION NUMBER

PROSPERO CRD42020129667.

0791 Effects of Low Frequency Electrical Stimulators as Nonpharmacological Treatment in Restless Legs Syndrome

Introduction

Non-pharmacological treatments for restless legs syndrome (RLS) is a treatment option for patients who have not yet started medical treatment, who do not respond to their prescribed medication, or who suffer from adverse effects of medication. This study aims to investigate the clinical effectiveness of low frequency electronic stimulators (LFES) as a non-pharmacological treatment.

Methods

This is a randomized, single-blind study. After screening 64 patients according to the inclusion/exclusion criteria, a total of 46 patients participated in the study. The participants were separated into an active group and a sham group with 22 and 24 members, respectively. The stimulation was administered using the tapping mode (3Hz) present on the machines used, and symptom changes were measured in both groups. The effects of the stimuli were analyzed with repeated measures ANOVA.

Results

Symptom severity was significantly reduced in the active group, and showed significant interaction effects in the time multiple group. Although both the active and sham groups reported improved symptoms upon receiving longer periods of treatment, the effect of the LFES was greater in the active group.

Conclusion

Analyzing the effects of LFES by dividing the active and sham groups revealed that LFES treatment resulted in symptom improvement when using effective stimulation intensity. LFES can be a non-pharmacological treatment option for RLS.

Support

None

Pharmacopuncture for the management of musculoskeletal diseases: A protocol for systematic review

BACKGROUND

Musculoskeletal disorders are the main reason for people to seek counseling and use of complementary and alternative medicine. Although pharmacopuncture is used to treat various diseases in traditional medicine, it is most often applied to treat musculoskeletal conditions. Here, we will review systematically the clinical evidence for the effectiveness and safety of pharmacopuncture for musculoskeletal diseases.

METHODS

A total of 13 databases will be searched for studies uploaded from January 2014 to December 2018 that investigated the treatment of musculoskeletal diseases. These databases are MEDLINE, EMBASE, AMED, Cochrane Library, CINAHL, 4 Korean databases, 2 Chinese database, and 2 Japanese databases. The methodological quality of randomized controlled trials will be analyzed using the Cochrane Collaboration tool to assess risk of bias, and the confidence in the cumulative evidence will be assessed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) instrument.

ETHICS AND DISSEMINATION

This systematic review will be published in a peer-reviewed journal and disseminated electronically and in print. To inform and guide healthcare practices, the review will be updated.

REGISTRATION NUMBER

CRD42019148795.

Cryopreservation of Endangered Wild Species, Aster altaicus var. uchiyamae Kitam, Using Droplet-Vitrification Procedure

BACKGROUND

Aster altaicus var. uchiyamae Kitam is an endemic and endangered species in urgent need of a comprehensive conservation strategy.

OBJECTIVE

To develop an efficient cryopreservation protocol using in vitro shoot tips to complement traditional conservation approaches in case seeds are not available or insufficient for conservation programs.

METHODS

Shoot tips of in vitro plants were cryopreserved using a droplet-vitrification method following improvement of pre-culture, osmoprotection, vitrification solution (VS), unloading and post-culture treatments. The starting protocol included step-wise pre-culture with 10% and 17.5% sucrose for 55 h and 17 h, respectively, followed by osmoprotection with C4-35% (17.5% glycerol + 17.5% sucrose) for 30 min, and cryoprotection with B5-80% (40% glycerol + 40% sucrose) for 60 min.

RESULTS

Shoot tips of A. altaicus were found to be moderately sensitive to the osmotic stress. Pre-culture and osmoprotection were not critical for the regeneration of cryopreserved explants when either of these treatments was applied. Osmoprotection with C4-35% on ice for 60 min followed by cryoprotection with A3-80%, a modified and diluted PVS2, on ice for 60 min resulted in the highest (65.3%) regeneration of cryopreserved shoot tips. Among alternative VSs tested, A3-80% and B5-80% were superior to PVS2 and PVS3 used under the same conditions. Step-wise recovery of shoot tips on ammonium-free medium followed by GA₃-containing medium and medium without growth regulators were critical for the normal regeneration of both VS-treated and cryopreserved shoot tips.

CONCLUSIONS

Cryopreservation of in vitro shoot tips using droplet-vitrification was developed as a complementary conservation approach for A. altaicus. Adjustment of the composition of regrowth media depending on recovery stage was important for the regeneration of healthy plants from cryopreserved shoot tips.

A magnetically driven piston pump for ultra-clean applications

A magnetically driven piston pump for xenon gas recirculation is presented. The pump is designed to satisfy extreme purity and containment requirements, as is appropriate for the recirculation of isotopically enriched xenon through the purification system and large liquid xenon time projection chamber of EXO-200. The pump, using sprung polymer gaskets, is capable of pumping more than 16 standard liters per minute of xenon gas with 750 Torr differential pressure.

Disrupted theory of mind network processing in response to idea of reference evocation in schizophrenia

OBJECTIVE

This study examined the neural pathophysiology of the theory of mind network by eliciting self-referential processing during an idea of reference evocating situation in patients with schizophrenia.

METHOD

Functional MRI was conducted on 14 schizophrenic in-patients with the idea of reference and 15 healthy participants while viewing video vignettes of referential conversations, non-referential conversations or no conversations between two people, which were filmed at varying distances of 1, 5 or 10 m.

RESULTS

The patient group did not show normal patterns of superior temporal sulcus activation to conversational context, and reciprocal deactivation and activation of the ventromedial and dorsomedial prefrontal cortex to referential conversational context. Instead, the patient group showed overall greater ventromedial prefrontal activities across different conversational contexts and inverse correlation between superior temporal sulcus activity and delusional severity. Differential activations of the temporal pole and its posterior extension to varying distances were observed in the control group but not in the patient group.

CONCLUSION

The present study demonstrates that theory of mind-related responses of the medial prefrontal-superior temporal network are attenuated during the self-referential processing in patients with schizophrenia and that these abnormalities may be related to the formation of their referential or persecutory delusion.

Assessment of post-stroke extrapersonal neglect using a three-dimensional immersive virtual street crossing program

OBJECTIVE

To investigate the potential of our newly developed three-dimensional immersive virtual reality (VR) program modeled on a real street crossing as an assessment tool for extrapersonal neglect in stroke patients.

METHODS

Thirty-two patients with right-hemispheric stroke (neglect group, 16; non-neglect group, 16) were enrolled. The deviation angle, reaction time, left-to-right reaction time ratio, visual and auditory cue rates, and failure rate were evaluated during missions to keep a virtual avatar safe from a traffic accident in the VR program. The line bisection test and letter cancellation test were also evaluated.

RESULTS

The deviation angle, left-to-right reaction time ratio, left visual and auditory cue rates and left failure rate in the VR program showed significant differences between the two groups (P < 0.05). Depending on the direction of approach of the virtual car, the left parameters were significantly higher than the right parameters in the neglect group (P < 0.05). In the neglect group, the line bisection test correlated significantly with the deviation angle (P < 0.05). None of the other virtual reality parameters significantly correlated with the paper and pencil tests.

CONCLUSION

Post-stroke neglect in the extrapersonal space can be easily and safely detected and measured using our three-dimensional immersive virtual street crossing program.

Syringomatous adenoma of the nipple

Infiltrating syringomatous adenoma (SA) of the nipple is a rare but distinct benign clinical entity affecting the breast. It needs to be included in the differential diagnosis of patients who present with a lump in the nipple/areola complex. It is similar histologically to a syringoma, a benign tumour originating in the ducts of the dermal sweat glands, and importantly needs to be distinguished from a tubular carcinoma. SA of the nipple is locally infiltrating but is not known to metastasise. It often presents as a subareolar lesion with clinical, mammographic and ultrasound findings suspicious for malignancy. Whilst it may be possible to suspect the diagnosis on fine needle cytology, core biopsy or excisional biopsy is usually required to establish the diagnosis. There is a tendency to recurrence if excision is incomplete. The following is a case report, literature review and discussion of the surgical management options available in this unusual condition.

Stapled versus sutured gastrointestinal anastomoses in the trauma patient: a multicenter trial

BACKGROUND

Construction of gastrointestinal anastomoses utilizing stapling devices has become a familiar procedure. In elective surgery, studies have shown no significant differences in complications between stapled and sutured anastomoses. Controversy has recently arisen regarding the accurate incidence of complications associated with anastomoses in the trauma patient. The objective of this multi-institutional study was to determine whether the incidence of postoperative complications differs between stapled and sutured anastomoses following the emergent repair of traumatic bowel injuries.

METHODS

Using a retrospective cohort design, all trauma registry records from five Level I trauma centers over a period of 4 years were reviewed.

RESULTS

A total of 199 patients with 289 anastomoses were identified. A surgical stapling device was used to create 175 separate anastomoses, while a hand-sutured method was employed in 114 anastomoses. A complication was defined as an anastomotic leak verified at reoperation, an intra-abdominal abscess, or an enterocutaneous fistula. The mean abdominal Abbreviated Injury Scale score and Injury Severity Score were similar in the two cohort groups. Stapling and suturing techniques were evenly distributed in both small and large bowel repairs. Seven of the total 175 stapled anastomoses and none of the 114 hand-sewn anastomoses resulted in a clinically significant leak requiring reoperation (RR = undefined, 95% CI 1.08-infinity, p = 0.04). Each anastomotic leak occurred in a separate individual. Nineteen stapled anastomoses and four sutured anastomoses were associated with an intra-abdominal abscess (RR = 2.7, 95% CI 0.96-7.57, p = 0.04). Enterocutaneous fistula formation was not statistically associated with either type of anastomoses (stapled cohort = 3 of 175 and sutured cohort = 2 of 114). Overall, 22 (13%) stapled anastomoses and 6 (5%) sutured anastomoses were associated with an intra-abdominal complication (RR = 2.08, 95% CI 0.89-4.86, p = 0.076).

CONCLUSION

Anastomotic leaks and intra-abdominal abscesses appear to be more likely with stapled bowel repairs compared with sutured anastomoses in the injured patient. Caution should be exercised in deciding to staple a bowel anastomosis in the trauma patient.

Development of virtual environment for treating acrophobia

Virtual Reality (VR) is a new technology that makes humans communicate with computer. It allows the user to see, hear, feel and interact in a three-dimensional virtual world created graphically. Virtual Reality Therapy (VRT), based on this sophisticated technology, has been recently used in the treatment of subjects diagnosed with acrophobia, a disorder that is characterized by marked anxiety upon exposure to heights, avoidance of heights, and a resulting interference in functioning. Conventional virtual reality system for the treatment of acrophobia has a limitation in scope that it is based on over-costly devices or somewhat unrealistic graphic scene. The goal of this study was to develop a inexpensive and more realistic virtual environment for the exposure therapy of acrophobia. We constructed two types virtual environment. One is constituted a bungee-jump tower in the middle of a city. It includes the open lift surrounded by props beside tower that allowed the patient to feel sense of heights. Another is composed of diving boards which have various heights. It provides a view of a lower diving board and people swimming in the pool to serve the patient stimuli upon exposure to heights.

Alteration in Kupffer cell function after mild hemorrhagic shock

Functional changes in Kupffer cells occur after profound hemorrhagic shock. This study was performed to demonstrate if Kupffer cell changes also occur after mild hemorrhagic shock. Sprague-Dawley rats were bled to a systolic blood pressure of 60 to 70 mmHg and resuscitated with Lactated Ringers solution (twice the shed blood volume) after 30 min. Resuscitation produced immediate recovery of blood pressure and allowed long-term recovery of the animals. Sham animals received anesthesia and monitoring only. Thirty minutes after resuscitation, Kupffer cells were isolated by centrifugal elutriation and cultured for 48 h. In Kupffer cells isolated from shocked animals, phorbol ester-stimulated superoxide production increased 7-fold and lipopolysaccharide- (LPS) stimulated prostaglandin E2 (PGE2) production increased 4-fold. Tumor necrosis factor-alpha (TNFalpha) production, on the other hand, was decreased by 50%. A non-significant trend toward increased phagocytosis was also observed, whereas LPS-stimulated nitric oxide production was unchanged. In conclusion, mild hemorrhagic shock produced increases in superoxide and PGE2 production, and decreases in TNFalpha production by Kupffer cells, changes that may be appropriate to defend against the infectious challenges that often follows trauma and hemorrhage.

Performance characteristics of the COBAS AmpliScreen HIV-1 test, version 1.5, an assay designed for screening plasma mini-pools

BACKGROUND

The COBAS AmpliScreen HIV-1 test, version 1.5 (v1.5) (Roche Molecular Systems), is designed for screening pools composed of samples from 24 individual units of blood or plasma. A specimen-processing procedure (Multiprep) simultaneously concentrates and extracts HIV-1, HCV, and HBV particles from plasma and incorporates an HIV-1 internal control (IC) RNA. Processed samples are amplified by RT-PCR using HIV-1-specific primers and detected by hybridization of the amplified products to HIV-1- and IC-specific oligonucleotide probes.

STUDY DESIGN AND METHODS

Plasma samples containing known quantities of HIV-1 were used to evaluate analytical sensitivity and precision and to validate a pool testing algorithm. Analytical specificity was evaluated by adding various viruses and bacteria to HIV-1-negative plasma. Seroconversion panels were tested to estimate the window-period reduction achieved by RNA testing.

RESULTS

The analytical sensitivity of the test (concentration that yields > or = 95% positive results in a set of replicate tests) was 25 copies of HIV-1 RNA per mL of pooled plasma. Representative strains from all HIV-1 group M subtypes were reproducibly detected (> 95% positive results) at concentrations of 20 to 200 viral particles per mL. The test did not cross-react with a set of 31 viral and 5 bacterial isolates, and it yielded negative results on a panel of 500 blood samples from HIV-1-seronegative donors. Plasma samples containing abnormally high levels of Hb, albumin, triglycerides, or bilirubin did not interfere with the test. HIV-1 RNA was detected 2 to 14 days before HIV-1 antibody and 0 to 28 days before p24 antigen. The test specifically detected pools containing a single positive unit with 2400 HIV-1 RNA copies per mL and correctly identified the positive unit.

CONCLUSION

The COBAS AmpliScreen HIV-1 test, v1.5, has sufficient sensitivity to detect a single infected unit containing 600 copies of HIV-1 per mL in a pool with 23 uninfected units and should reduce the window period between infection and seroconversion by at least 2 to 14 days.

Nifedipine controlled delivery by sandwiched osmotic tablet system

The sandwiched osmotic tablet system (SOTS), which is composed of a sandwiched osmotic tablet core surrounded by a cellulose acetate membrane with two orifices on both side surfaces, has been successfully prepared with the purpose of delivering nifedipine. The sandwiched osmotic tablet core consists of a middle push layer and two attached drug layers. Influences of tablet formulation variables, orifice size and membrane variables on nifedipine release of SOTS have been studied. It was found that potassium chloride amount of push layer and polyethylene oxide amount of drug layer had markedly positive effects on nifedipine release. A push layer/drug layer co-controlled osmotic delivery mechanism and the optimal core formulation have been proposed. The appropriate orifice size was observed in the range of 0.50-1.41 mm. It was also found that the drug release rate of SOTS could be increased by incorporating hydrophilic plasticizer in the membrane, whereas it decreased with hydrophobic plasticizer. It has been observed that the SOTS gives fairly comparable in vitro release features as that of commercialized push-pull osmotic tablet system, such as an approximately constant rate up to 24 h and independence of release media and agitation rate. Exempting side identification before drilling, it is easier to prepare the SOTS than the push-pull osmotic tablet system.

Simultaneous extraction of hepatitis C virus (HCV), hepatitis B virus, and HIV-1 from plasma and detection of HCV RNA by a reverse transcriptase-polymerase chain reaction assay designed for screening pooled units of donated blood

BACKGROUND

Testing for viral nucleic acids should reduce the residual risk of transmitting viral infections by transfusion of blood components. The AmpliScreen Hepatitis C (HCV) Test, Version 2.0, was designed for screening pools composed of samples from individual units of blood or plasma.

STUDY DESIGN AND METHODS

An ultracentrifugation step during sample processing simultaneously extracts and concentrates HCV, HIV type 1, and hepatitis B virus particles from plasma. An HCV internal control RNA serves as an extraction and amplification control for each processed sample. Processed samples are amplified by reverse transcriptase polymerase chain reaction and detected by hybridization of the amplified products to HCV- and internal-control-specific oligonucleotide probes. Plasma samples containing known quantities of HCV were used to evaluate analytical sensitivity and precision.

RESULTS

The analytical sensitivity of the test was 25 IU of HCV per mL of pooled plasma; all HCV genotypes were detected with similar efficiency. The test did not react with other blood-borne viruses. The within-run and total coefficients of variation were 1.3-13.0 percent and 1.7-22.0 percent, respectively, with low copy samples producing the more variable results. The test performed well using plasma collected in either EDTA, ACD, or PPT Vacutainer tubes. Plasma samples containing elevated levels of hemoglobin, albumin, triglycerides, or bilirubin did not interfere with the test. The test detected HCV RNA 23 to 32 days prior to seroconversion for four of the five seroconversion panels tested.

CONCLUSION

The AmpliScreen HCV Test, Version 2.0 provides a reproducible and specific method for screening pooled blood units for HCV. Theoretically, this test has sufficient sensitivity to detect a single infected unit containing 2.4 x 10(3) IU of HCV per mL in a pool with 95 uninfected units and should reduce the window period by at least 20 to 30 days.

Identification of the 16S rRNA m5C967 methyltransferase from Escherichia coli

The fmu gene product has been proposed to be an RNA methyltransferase [Koonin, E. V. (1994) Nucleic Acids Res. 22, 2476-2478]. Fmu has been cloned and expressed, and the encoded 47 kDa protein has been purified and characterized. The enzyme catalyzed specific methylation of C967 of unmodified 16S rRNA transcripts. A 16mer stem-loop structure containing C967 (nt 960-975) was also a good substrate for the enzyme in vitro. Methylation of C967 was confirmed by several methods including analysis of RNase T1 digests and nearest-neighbor analysis. Fmu did not catalyze methylation of transcripts of 23S rRNA. E. coli cells that contained kanr-disrupted fmu produced 16S rRNA that could be specifically methylated by Fmu in vitro at C967 but not C1407. Further, fmu disruption did not significantly alter the growth rate of E. coli in rich or minimal media. We propose renaming this ORF "rrmB" and the enzyme "RrmB" for rRNA methyltransferase.

Identification of two Escherichia coli pseudouridine synthases that show multisite specificity for 23S RNA

Several putative Escherichia coli pseudouridine (Psi) synthases have been identified by iterative searching of genomic databases for ORFs homologous to known Psi synthases [Gustafsson et al. (1996) Nucleic Acids Res. 24, 3756-3762]. Of these, yceC and yfiI were proposed to encode Psi synthases which modify 23S rRNA. In the present work, yceC and yfiI were cloned and overexpressed in E. coli, and the encoded enzymes, YceC and YfiI, were purified to homogeneity. Both proteins converted Urd residues of rRNA to Psi, thus confirming their identities as Psi synthases. However, in in vitro experiments both enzymes extensively modified Urd residues of both 23S rRNA and 16S rRNA. Gene-disruption of yceCresulted in the absence of Psi modification at positions U955, 2504, and 2580 of 23S RNA, thus identifying these sites as in vivo targets for YceC. Likewise, yfiI disruption resulted in the absence of Psi modification at positions U1911, 1917, and possibly 1915 of 23S RNA. Disruption of yceC did not affect the growth under the conditions tested, whereas yfiI-disrupted cells showed a dramatic decrease in growth rate. Since YceC and YfiI hypermodify RNA in vitro, factors in addition to ribonucleotide sequence must contribute to the in vivo specificity of these enzymes.