Anesthesiologist’s role as a communication coordinator of perioperative medicine: stressing the recognition of role in the changing medical atmosphere

Background: Perioperative care process in a hospital is considerably complex, involving multiple subprocesses, healthcare professionals, and systems in support of surgical care. The perioperative process is often the primary source of hospital admissions, driving the dominant part of hospital margins and accounts for a major part of all adverse events occurring in hospitals. The recent trend stresses the importance of adopting patient-centered and quality-proven care in many medical fields. Further, the emphasis on changing from fee-for-service to fee-for-value is increasing. These changes present challenges to anesthesiologists who play a central role in perioperative medicine.Current Concepts: Anesthesiologists are in contact with many surgeons and patients and are positioned to improve clinical outcomes. They need to have up-to-date, evidence-based knowledges on perioperative clinical management and know-how to apply, organize and practice them into efficient pathways for optimal outcomes. To accomplish such purposes, anesthesiologists need to acquire communication skills to reason and convincing related personnel including surgeons and patients.Discussion and Conclusion: The recent changing climate of perioperative medicine calls upon anesthesiologists to acquire knowledges driving quality care and demands the application of communicative skills to accomplish the required tasks.

Performance of the MP570T pulse oximeter in volunteers participating in the controlled desaturation study: a comparison of seven probes

Background

The performance of the pulse oximeter was evaluated based on the ISO 80601-2-61:2011 (E) guidelines. This study aimed to determine whether the various finger probes of the MP570T pulse oximeter (MEK-ICS Co., Ltd., Korea) would provide clinically reliable peripheral oxygen saturation (SpO₂) readings over a range of 70-100% arterial oxygen saturation (SaO₂) during non-motion conditions.

Methods

Each volunteer (n = 12) was connected to a breathing circuit for the administration of a hypoxic gas mixture. For frequent blood sampling, an arterial cannula was placed in a radial artery. The following seven pulse oximeter probes were simultaneously attached to each volunteer’s fingers: (1) WA-100 reusable finger probe (MEDNIS Co., Ltd., Korea), (2) MDNA disposable finger probe (MEDNIS Co., Ltd.), (3) IS-1011 disposable finger probe (Insung Medical Co., Ltd., Korea), (4) CJ340NA disposable finger probe (CHUN JI IN Medical Co., Ltd., Korea), (5) Nellcor^TM OxiMax DS-100A reusable finger probe (Medtronic, USA), (6) Nellcor^TM OxiMax MAX-N disposable finger probe (Medtronic), and (7) OXI-PRO DA disposable finger probe (Bio-Protech Inc., Korea).

Results

A total of 275 SpO₂-SaO₂ pairs were included in the analysis. The accuracy of the root mean square (A_rms) of each probe was 2.83%, 3.98%, 3.75%, 6.84%, 3.43%, 5.17%, and 3.84%, respectively.

Conclusions

The MP570T pulse oximeter with WA-100 reusable, MDNA disposable, IS-1011 disposable, Nellcor^TM OxiMax DS-100A reusable, and OXI-PRO DA disposable finger probes meets an acceptable standard of SpO₂ accuracy under non-motion conditions.

Quantitative analysis of the effect of fraction of inspired oxygen on peripheral oxygen saturation in healthy volunteers

Background

The international organization for standardization (ISO) 80601-2-61 dictates that the accuracy of a pulse oximeter should be assessed by a controlled desaturation study. We aimed to characterize the relationship between the fraction of inspired oxygen (FiO₂) and peripheral oxygen saturation (SpO₂) using a turnover model by retrospectively analyzing the data obtained from previous controlled desaturation studies.

Materials and Methods

Each volunteer was placed in a semi-Fowler's position and connected to a breathing circuit to administer the hypoxic gas mixture containing medical air, oxygen, nitrogen, and carbon dioxide. Volunteers were exposed to various levels of induced hypoxia over 70–100% arterial oxygen saturation (SaO₂). The study period consisted of two rounds of hypoxia and the volunteers were maintained in room air between each round. FiO₂ and SpO₂ were recorded continuously during the study period. A population pharmacodynamic analysis was performed with the NONMEM VII level 4 (ICON Development Solutions, Ellicott City, MD, USA).

Results

In total, 2899 SpO₂ data points obtained from 20 volunteers were used to determine the pharmacodynamic characteristics. The pharmacodynamic parameters were as follows: k_out = 0.942 1/min, I_max = 0.802, IC₅₀ = 85.3%, γ = 27.3.

Conclusion

The changes in SpO₂ due to decreases in FiO₂ well explained by the turnover model with inhibitory function as a sigmoidal model.

Effects of dietary Lycium barbarum polysaccharides on growth performance, digestive enzyme activities, antioxidant status, and immunity of broiler chickens

Lycium barbarum polysaccharides (LBP) are considered to be the major bioactive components of L. barbarum and have been widely used as a well-known traditional Chinese medicine and functional food because of their various biological activities. However, no published research has investigated the use of LBP as a feed additive in broilers. The objective of this study was to evaluate the effects of dietary LBP supplementation on the growth performance, digestive enzyme activities, antioxidant status, and immunity of broiler chickens. A total of 256 one-day-old Arbor Acres male broiler chicks were randomly allotted into 4 groups, with 8 replicates of 8 birds each, and were fed a corn-soybean meal-type basal diet supplemented without (control group) or with 1,000, 2,000, or 4,000 mg/kg LBP for 6 wk. The results showed that compared with the control diet, a significant increase in ADG (P < 0.05) during the grower and overall periods was observed in chickens fed the basal diet supplemented with 2,000 mg/kg LBP, whereas supplementation with 1,000 or 2,000 mg/kg LBP decreased feed-to-gain ratio (P < 0.05) during the starter period. The inclusion of LBP in the broiler diets increased overall amylase, lipase, and protease activities (P < 0.05). Supplementation with increasing levels of dietary LBP increased the activities of superoxide dismutase and glutathione peroxidase but decreased malondialdehyde content in the serum and liver (P < 0.05). Broilers fed with LBP-containing diets exhibited higher serum IgG and IgA concentrations (P < 0.05) than the broilers fed with the control diet. Serum tumor necrosis factor α and IL-4 concentrations were significantly elevated in the group fed 2,000 mg/kg LBP compared with the control group (P < 0.05). Broilers fed diets supplemented with LBP showed linear (P < 0.05) and quadratic (P < 0.05) increases in serum IL-6 and interferon gamma concentrations. The results indicated that dietary LBP supplementation can improve growth performance, digestive enzyme activities, antioxidant capacity, and immune function of broilers. In conclusion, LBP may be used as a promising feed additive for broilers, and a supplementation level of 2,000 mg/kg LBP in the broiler diet is recommended.

Prone positioning before extracorporeal membrane oxygenation for severe acute respiratory distress syndrome: A retrospective multicenter study

OBJECTIVE

To evaluate the clinical outcomes of patients with severe acute respiratory distress syndrome (ARDS) subjected to prone positioning before extracorporeal membrane oxygenation (ECMO).

DESIGN

A retrospective analysis of a multicenter cohort was carried out.

SETTING

Patients admitted to the Intensive Care Units of 11 hospitals in Korea.

PATIENTS

Patients were divided into those who underwent prone positioning before ECMO (n=28) and those who did not (n=34).

INTERVENTIONS

None.

VARIABLES OF INTEREST

Thirty-day mortality, ECMO weaning failure rate, mechanical ventilation weaning success rate, mechanical ventilation-free days at day 60.

RESULTS

The prone group had lower median peak inspiratory pressure and lower median dynamic driving pressure before ECMO. Thirty-day mortality was 21% in the prone group and 41% in the non-prone group (p=0.098). The prone group also showed a lower ECMO weaning failure rate, and a higher mechanical ventilation weaning success rate and more mechanical ventilation-free days at day 60. In the non-prone group, median dynamic compliance marginally decreased shortly after ECMO, but no significant change was observed in the prone group.

CONCLUSIONS

Prone positioning before ECMO was not associated to increased mortality and tended to exert a protective effect.

CMOS High-Voltage Analog 1-64 Multiplexer/Demultiplexer for Integrated Ultrasound Guided Breast Needle Biopsy

Ultrasound guided needle biopsy is an important method for collection of breast cancer tissue. In this paper, we report on the design and testing of a high-voltage 1 to 64 Multiplexer/Demultiplexer (MUX/De-MUX) integrated circuit (IC) for ultrasound-guided breast biopsy applications implemented in a high-voltage CMOS process. The IC is intended to be incorporated inside the breast biopsy needle and is designed to fit inside the needle inner diameter of 2.38 mm. The MUX/De-MUX electronics are made up of three parts, including a low-voltage 6 to 64 decoder, a level shifter to convert from low voltage to high voltage, and analog high-voltage switches. Experimental results show a -3-dB bandwidth of over 70 MHz, Rds (on) of , -2.279-dB insertion loss, and -17.5-dB off isolation at 70 MHz with low-voltage input. Finally, we present results obtained via synthetic aperture imaging using the fabricated MUX/De-Mux device and a high-frequency ultrasound array. This device and technique hold promise for high-frequency imaging probes where a limited number of elements are used and the depth of penetration is short such as in breast biopsy and intravascular applications.

Prone positioning before extracorporeal membrane oxygenation for severe acute respiratory distress syndrome: A retrospective multicenter study

OBJECTIVE

To evaluate the clinical outcomes of patients with severe acute respiratory distress syndrome (ARDS) subjected to prone positioning before extracorporeal membrane oxygenation (ECMO).

DESIGN

A retrospective analysis of a multicenter cohort was carried out.

SETTING

Patients admitted to the Intensive Care Units of 11 hospitals in Korea.

PATIENTS

Patients were divided into those who underwent prone positioning before ECMO (n=28) and those who did not (n=34).

INTERVENTIONS

None.

VARIABLES OF INTEREST

Thirty-day mortality, ECMO weaning failure rate, mechanical ventilation weaning success rate, mechanical ventilation-free days at day 60.

RESULTS

The prone group had lower median peak inspiratory pressure and lower median dynamic driving pressure before ECMO. Thirty-day mortality was 21% in the prone group and 41% in the non-prone group (p=0.098). The prone group also showed a lower ECMO weaning failure rate, and a higher mechanical ventilation weaning success rate and more mechanical ventilation-free days at day 60. In the non-prone group, median dynamic compliance marginally decreased shortly after ECMO, but no significant change was observed in the prone group.

CONCLUSIONS

Prone positioning before ECMO was not associated to increased mortality and tended to exert a protective effect.

Exploring the pros and cons of mechanistic case diagrams for problem-based learning

PURPOSE

Mechanistic case diagram (MCD) was recommended for increasing the depth of understanding of disease, but with few articles on its specific methods. We address the experience of making MCD in the fullest depth to identify the pros and cons of using MCDs in such ways.

METHODS

During problem-based learning, we gave guidelines of MCD for its mechanistic exploration from subcellular processes to clinical features, being laid out in as much detail as possible. To understand the students' attitudes and depth of study using MCDs, we analyzed the results of a questionnaire in an open format about experiencing MCDs and examined the resulting products.

RESULTS

Through the responses to questionnaire, we found several favorable outcomes, major of which was deeper insight and comprehensive understanding of disease facilitated by the process of making well-organized diagram. The main disadvantages of these guidelines were the feeling of too much workload and difficulty of finding mechanisms. Students gave suggestions to overcome these problems: cautious reading of comprehensive texts, additional guidance from staff about depth and focus of mechanisms, and cooperative group work. From the analysis of maps, we recognized there should be allowance of diversities in the appearance of maps and many hypothetical connections, which could be related to an insufficient understanding of mechanisms in nature.

CONCLUSION

The more detailed an MCD task is, the better students can become acquainted with deep knowledges. However, this advantage should be balanced by the results that there are many ensuing difficulties for the work and deliberate help plans should be prepared.

Fabrication and Characterization of a 20-MHz Microlinear Phased-Array Transducer for Intervention Guidance

This paper describes the design and fabrication of a miniature ultrasonic phased-array transducer used for intervention guidance. Currently, ultrasound probes are often placed at the body surface of the patients, leading to several drawbacks including the limitation of penetration and image quality. In order to improve the reliability of the guiding process, we propose a miniature phased-array transducer that can be placed adjacent to the intervention device during the interventional procedure. In this paper, we report the work that has been carried out on the development of this miniature phased-array transducer. It comprised 48 elements housed in a 3-mm-diameter needle. A specially designed flexible circuit was used for accommodating the transducer array in the long, thin needle housing. The center frequency and the fractional bandwidth were approximately 20 MHz and 42%, respectively, with an average crosstalk lower than -30 dB. The axial and azimuth resolutions were approximately 80 and [Formula: see text], respectively. The imaging capability of the transducer was further evaluated by acquiring the B-mode images of a needle in a cow liver. The performance of the proposed phased-array transducer demonstrates the feasibility of such an approach for interventional guidance.

Abstract P6-09-42: The role of serum neutrophil-to-lymphocyte ratio (NLR) in triple-negative breast cancer

This abstract was not presented at the symposium.

Basic Fibroblast Growth Factor Improved Angiogenesis of Vitrified Human Ovarian Tissues after in vitro Culture and Xenotransplantation

BACKGROUND

Basic fibroblast growth factor is a potent angiogenic factor.

OBJECTIVE

To study the concentration and in vitro culture time of bFGF that maximize the angiogenesis for transplanted human ovarian tissues.

MATERIALS AND METHODS

Vitrified and rewarmed human ovarian tissues were cultured in vitro with bFGF (0, 25, 50, 100, 150 and 200 ng/ml) for different periods (1 h, 2 d, 5 d and 7 d) before transplantation. The effect of bFGF on follicle survival was studied by evaluating the pregraft group, control group (no bFGF) and bFGF-treated group. CD34, Ki-67 and AC-3 immuno-histochemical (IHC) staining and histological analysis was used to evaluate angiogenesis, proliferration, apoptosis and follicular quantity.

RESULTS

Treatments with 100 and 150 ng/ml bFGF improved the angiogenesis for grafted human ovarian tissues after in vitro culture for 2 days. The proliferation and survival of follicles were significantly increased.

CONCLUSION

bFGF improved the quality of vitrified-warmed human ovarian tissues after transplantation.

Hemodynamics and ventricular function in a zebrafish model of injury and repair

Myocardial infarction results in scar tissue and irreversible loss of ventricular function. Unlike humans, zebrafish has the capacity to remove scar tissue after injury. To assess ventricular function during repair, we synchronized microelectrocardiogram (μECG) signals with a high-frequency ultrasound pulsed-wave (PW) Doppler to interrogate cardiac hemodynamics. μECG signals allowed for identification of PW Doppler signals for passive (early [E]-wave velocity) and active ventricular filling (atrial [A]-wave velocity) during diastole. The A wave (9.0±1.2 cm·s(-1)) is greater than the E wave (1.1±0.4 cm·s(-1)), resulting in an E/A ratio <1 (0.12±0.05, n=6). In response to cryocauterization to the ventricular epicardium, the E-wave velocity increased, accompanied by a rise in the E/A ratio at 3 days postcryocauterization (dpc) (0.55±0.13, n=6, p<0.001 vs. sham). The E waves normalize toward the baseline, along with a reduction in the E/A ratio at 35 dpc (0.36±0.06, n=6, p<0.001 vs. sham) and 65 dpc (0.2±0.16, n=6, p<0.001 vs. sham). In zebrafish, E/A<1 at baseline is observed, suggesting the distinct two-chamber system in which the pressure gradient across the atrioventricular valve is higher compared with the ventriculobulbar valve. The initial rise and subsequent normalization of E/A ratios support recovery in the ventricular diastolic function.

High-frequency dual mode pulsed wave Doppler imaging for monitoring the functional regeneration of adult zebrafish hearts

Adult zebrafish is a well-known small animal model for studying heart regeneration. Although the regeneration of scars made by resecting the ventricular apex has been visualized with histological methods, there is no adequate imaging tool for tracking the functional recovery of the damaged heart. For this reason, high-frequency Doppler echocardiography using dual mode pulsed wave Doppler, which provides both tissue Doppler (TD) and Doppler flow in a same cardiac cycle, is developed with a 30 MHz high-frequency array ultrasound imaging system. Phantom studies show that the Doppler flow mode of the dual mode is capable of measuring the flow velocity from 0.1 to 15 cm s(-1) with high accuracy (p-value = 0.974 > 0.05). In the in vivo study of zebrafish, both TD and Doppler flow signals were simultaneously obtained from the zebrafish heart for the first time, and the synchronized valve motions with the blood flow signals were identified. In the longitudinal study on the zebrafish heart regeneration, the parameters for diagnosing the diastolic dysfunction, for example, E/Em < 10, E/A < 0.14 for wild-type zebrafish, were measured, and the type of diastolic dysfunction caused by the amputation was found to be similar to the restrictive filling. The diastolic function was fully recovered within four weeks post-amputation.

Jitter reduction technique for acoustic radiation force impulse microscopy via photoacoustic detection

We demonstrate a jitter noise reduction technique for acoustic radiation force impulse microscopy via photoacoustic detection (PA-ARFI), which promises to be capable of measuring cell mechanics. To reduce the jitter noise induced by Q-switched pulsed laser operated at high repetition frequency, photoacoustic signals from the surface of an ultrasound transducer are aligned by cross-correlation and peak-to-peak detection, respectively. Each method is then employed to measure the displacements of a target sample in an agar phantom and a breast cancer cell due to ARFI application, followed by the quantitative comparison between their performances. The suggested methods for PA-ARFI significantly reduce jitter noises, thus allowing us to measure displacements of a target cell due to ARFI application by less than 3 μm.

Angled-focused 45 MHz PMN-PT single element transducer for intravascular ultrasound imaging

A transducer with an angled and focused aperture for intravascular ultrasound imaging has been developed. The acoustic stack for the angled-focused transducer was made of PMN-PT single crystal with one matching layer, one protective coating layer, and a highly damped backing layer. It was then press-focused to a desired focal length and inserted into a thin needle housing with an angled tip. A transducer with an angled and unfocused aperture was also made, following the same fabrication procedure, to compare the performance of the two transducers. The focused and unfocused transducers were tested to measure their center frequencies, bandwidths, and spatial resolutions. Lateral resolution of the angled-focused transducer (AFT) improved more than two times compared to that of the angled-unfocused transducer (AUT). A tissue-mimicking phantom in water and a rabbit aorta tissue sample in rabbit blood were scanned using AFT and AUT. Imaging with AFT offered improved contrast, over imaging with AUT, of the tissue-mimicking phantom and the rabbit aorta tissue sample by 23 dB and 8 dB, respectively. The results show that AFT has strong potential to provide morphological and pathological information of coronary arteries with high resolution and high contrast.

Electrical and Mechanical Strategies to Enable Cardiac Repair and Regeneration

Inadequate replacement of lost ventricular myocardium from myocardial infarction leads to heart failure. Investigating the regenerative capacity of mammalian hearts represents an emerging direction for tissue engineering and cell-based therapy. Recent advances in stem cells hold promise to restore cardiac functions. However, embryonic or induced pluripotent stem cell-derived cardiomyocytes lack functional phenotypes of the native myocardium, and transplanted tissues are not fully integrated for synchronized electrical and mechanical coupling with the host. In this context, this review highlights the mechanical and electrical strategies to promote cardiomyocyte maturation and integration, and to assess the functional phenotypes of regenerating myocardium. Simultaneous microelectrocardiogram and high-frequency ultrasound techniques will also be introduced to assess electrical and mechanical coupling for small animal models of heart regeneration.

Dual-element needle transducer for intravascular ultrasound imaging

A dual-element needle transducer for intravascular ultrasound imaging has been developed. A low-frequency element and a high-frequency element were integrated into one device to obtain images which conveyed both low- and high-frequency information from a single scan. The low-frequency element with a center frequency of 48 MHz was fabricated from the single crystal form of lead magnesium niobate-lead titanate solid solution with two matching layers (MLs) and the high frequency element with a center frequency of 152 MHz was fabricated from lithium niobate with one ML. The measured axial and lateral resolutions were 27 and [Formula: see text], respectively, for the low-frequency element, and 14 and [Formula: see text], respectively, for the high-frequency element. The performance of the dual-element needle transducer was validated by imaging a tissue-mimicking phantom with lesion-mimicking area, and ex vivo rabbit aortas in water and rabbit whole blood. The results suggest that a low-frequency element effectively provides depth resolved images of the whole vessel and its adjacent tissue, and a high-frequency element visualizes detailed structure near the surface of the lumen wall in the presence of blood within the lumen. The advantages of a dual-element approach for intravascular imaging are also discussed.

Non-contact acoustic radiation force impulse microscopy via photoacoustic detection for probing breast cancer cell mechanics

We demonstrate a novel non-contact method: acoustic radiation force impulse microscopy via photoacoustic detection (PA-ARFI), capable of probing cell mechanics. A 30 MHz lithium niobate ultrasound transducer is utilized for both detection of phatoacoustic signals and generation of acoustic radiation force. To track cell membrane displacements by acoustic radiation force, functionalized single-walled carbon nanotubes are attached to cell membrane. Using the developed microscopy evaluated with agar phantoms, the mechanics of highly- and weakly-metastatic breast cancer cells are quantified. These results clearly show that the PA-ARFI microscopy may serve as a novel tool to probe mechanics of single breast cancer cells.

Multi-particle trapping and manipulation by a high-frequency array transducer

We report the multiple micro-particle trapping and manipulation by a single-beam acoustic tweezer using a high-frequency array transducer. A single acoustic beam generated by a 30 MHz ultrasonic linear array transducer can entrap and transport multiple micro-particles located at the main lobe and the grating lobes. The distance between trapped particles can be adjusted by changing the transmit arrangement of array-based acoustic tweezers and subsequently the location of grating lobes. The experiment results showed that the proposed method can trap and manipulate multiple particles within a range of hundreds of micrometers. Due to its simplicity and low acoustic power, which is critical to protect cells from any thermal and mechanical damages, the technique may be used for transportation of cells in cell biology, biosensors, and tissue engineering.

Trigemino-cardiac reflex: occurrence of asystole during trans-sphenoidal adenomectomy: a case report

The trigemino-cardiac reflex has been reported to occur during various craniofacial surgeries or procedures including manipulation of the trigeminal ganglion, tumor resection in the cerebellopontine angle, various facial reconstructions and trans-sphenoidal adenomectomy. Regarding risk factors during trans-sphenoidal adenomectomy, invasiveness closely related to the size of tumor and the degree of manipulation of cavernous sinus wall have been reported. We report the case of a 40-year-old female patient who had a relatively small-sized (< 10 mm) pituitary adenoma. Repetitive asystoles occurred during microscopic trans-sphenoidal operation of the wall of the cavernous sinus, which strongly suggests the importance of careful manipulation of the cavernous sinus wall. In addition to reporting this rare complication of trans-sphenoidal adenomectomy, we reviewed its clinical management by performing a literature search.

The effects of ethnic, social and cultural factors on axis I comorbidity of bipolar disorder: results from the clinical setting in Korea

OBJECTIVE

Ethnic, social and cultural factors contribute to axis I comorbid conditions in bipolar disorder (BPD). Korea has strict laws against illicit drugs and a relatively permissive prevailing attitude toward alcohol. The present study aimed to explore the lifetime axis I comorbidity rate in patients with BPD in Korea.

METHODS

Clinically stable patients with bipolar I (n=222) and bipolar II (n=194) disorders were recruited from four tertiary medical centers in Korea. The subjects׳ diagnoses and axis I comorbid conditions were evaluated using the Structured Clinical Interview for DSM-IV Axis I Disorders (SCID) and the Korean version of the Diagnostic Interview for Genetic Studies (K-DIGS). The lifetime prevalence of anxiety disorders, substance use disorders and eating disorders was explored. The prevalence of these axis I comorbid conditions was compared with data from prior studies in other countries and to data concerning the general Korean population.

RESULTS

A total of 45.1% of all subjects had at least one axis I comorbid condition. Anxiety disorders (30.2%) were the most common comorbidity, followed by alcohol use disorders (16.8%). Males with BPD showed a higher rate of alcohol dependence compared to the general male population and females with BPD showed a greater risk of having alcohol use disorder compared to the general female population. The rate of drug use disorder was extremely low (1.7%), and only one subject had an illicit-drug-related problem.

LIMITATION

Cross-sectional studies.

CONCLUSION

Comorbid conditions of Korean patients with BPD showed a distinct pattern, which is associated with the ethnic, social and cultural characteristics in Korea.

Non-contact high-frequency ultrasound microbeam stimulation for studying mechanotransduction in human umbilical vein endothelial cells

We describe how contactless high-frequency ultrasound microbeam stimulation (HFUMS) is capable of eliciting cytoplasmic calcium (Ca(2+)) elevation in human umbilical vein endothelial cells. The cellular mechanotransduction process, which includes cell sensing and adaptation to the mechanical micro-environment, has been studied extensively in recent years. A variety of tools for mechanical stimulation have been developed to produce cellular responses. We developed a novel tool, a highly focused ultrasound microbeam, for non-contact cell stimulation at a microscale. This tool, at 200 MHz, was applied to human umbilical vein endothelial cells to investigate its potential to elicit an elevation in cytoplasmic Ca(2+) levels. It was found that the response was dose dependent, and moreover, extracellular Ca(2+) and cytoplasmic Ca(2+) stores were involved in the Ca(2+) elevation. These results suggest that high-frequency ultrasound microbeam stimulation is potentially a novel non-contact tool for studying cellular mechanotransduction if the acoustic pressures at such high frequencies can be quantified.

Effectiveness of milrinone for cardiogenic shock due to massive pulmonary aspiration: a case report

Pulmonary aspiration of gastric contents is one of the most frightening complications during anesthesia. Although pulmonary aspiration of gastric contents in general surgical patients is not common and resulting long-term morbidity and mortality are rare, severe hypoxemia and other sequelae of pulmonary aspiration continue to be reported. We report a case of massive aspiration of gastric contents during induction of general anesthesia, resulting in cardiac arrest due to severe pulmonary hypertension and myocardial infarction. Sustained cardiac arrest and shock that did not respond the conventional resuscitation was successfully treated using milrinone. The patient was discharged without complications in 20 days.

Radiological measurement of femoral stem version using a modified Budin method

Version of the femoral stem is an important factor influencing the risk of dislocation after total hip replacement (THR) as well as the position of the acetabular component. However, there is no radiological method of measuring stem anteversion described in the literature. We propose a radiological method to measure stem version and have assessed its reliability and validity. In 36 patients who underwent THR, a hip radiograph and CT scan were taken to measure stem anteversion. The radiograph was a modified Budin view. This is taken as a posteroanterior radiograph in the sitting position with 90° hip flexion and 90° knee flexion and 30° hip abduction. The angle between the stem-neck axis and the posterior intercondylar line was measured by three independent examiners. The intra- and interobserver reliabilities of each measurement were examined. The radiological measurements were compared with the CT measurements to evaluate their validity. The mean radiological measurement was 13.36° (sd 6.46) and the mean CT measurement was 12.35° (sd 6.39) (p = 0.096). The intra- and interobserver reliabilities were excellent for both measurements. The radiological measurements correlated well with the CT measurements (p = 0.001, r = 0.877). The modified Budin method appears reliable and valid for the measurement of femoral stem anteversion.

Minimum effective volume of mepivacaine for ultrasound-guided supraclavicular block

BACKGROUND

The aim of this study was to estimate the minimum effective volume (MEV) of 1.5% mepivacaine for ultrasound-guided supraclavicular block by placing the needle near the lower trunk of brachial plexus and multiple injections.

METHODS

Thirty patients undergoing forearm and hand surgery received ultrasound-guided supraclavicular block with 1.5% mepivacaine. The initial volume of local anesthetic injected was 24 ml, and local anesthetic volume for the next patient was determined by the response of the previous patient. The next patient received a 3 ml higher volume in the case of the failure of the previous case. If the previous block was successful, the next volume was 3 ml lower. MEV was estimated by the Dixon and Massey up and down method. MEV in 95, 90, and 50% of patients (MEV95, MEV90, and MEV50) were calculated using probit transformation and logistic regression.

RESULTS

MEV95 of 1.5% mepivacaine was 17 ml (95% confidence interval [CI], 13-42 ml), MEV90 was 15 ml (95% CI, 12-34 ml), and MEV50 was 9 ml (95% CI, 4-12 ml). Twelve patients had a failed block. Three patients received general anesthesia. Nine patients could undergo surgery with sedation only. Only one patient showed hemi-diaphragmatic paresis.

CONCLUSIONS

MEV95 was 17 ml, MEV90 was 15 ml, and MEV50 was 9 ml. However, needle location near the lower trunk of brachial plexus and multiple injections should be performed.

Comparison of ultrasound-guided supraclavicular block according to the various volumes of local anesthetic

Background

The ultrasound guidance in regional nerve blocks has recently been introduced and gaining popularity. Ultrasound-guided supraclavicular block has many advantages including the higher success rate, faster onset time, and fewer complications. The aim of this study was to examine the clinical data according to the varied volume of local anesthetics in the ultrasound-guided supraclavicular block.

Methods

One hundred twenty patients were randomized into four groups, according to the local anesthetic volume used: Group 35 (n = 30), Group 30 (n = 30), Group 25 (n = 30), and Group 20 (n = 30). Supraclavicular blocks were performed with 1% mepivacaine 35 ml, 30 ml, 25 ml, and 20 ml, respectively. The success rate, onset time, and complications were checked and evaluated.

Results

The success rate (66.7%) was lower in Group 20 than that of Group 35 (96.7%) (P < 0.05). The average onset times of Group 35, Group 30, Group 25, and Group 20 were 14.3 ± 6.9 min, 13.6 ± 4.5 min, 16.7 ± 4.6 min, and 16.5 ± 3.7 min, respectively. There were no significant differences. Horner's syndrome was higher in Group 35 (P < 0.05).

Conclusions

In conclusion, we achieved 90% success rate with 30 ml of 1% mepivacaine. Therefore, we suggest 30 ml of local anesthetic volume for ultrasound-guided supraclavicular block.

Experience with Using Multiple Types of Visual Educational Tools during Problem-Based Learning

PURPOSE

This study describes the experience of using multiple types of visual educational tools in the setting of problem-based learning (PBL). The author intends to demonstrate their roles in diverse and efficient ways of clinical reasoning and problem solving.

METHODS

Visual educational tools were introduced in a lecture that included their various types, possible benefits, and some examples. Each group made one mechanistic case diagram per week, and each student designed one diagnostic schema or therapeutic algorithm per week, based on their learning issues. The students were also told to provide commentary, which was intended to give insights into their truthfulness. Subsequently, the author administered a questionnaire about the usefulness and weakness of visual educational tools and the difficulties with performing the work. Also, the qualities of the products were assessed by the author.

RESULTS

There were many complaints about the adequacy of the introduction of visual educational tools, also revealed by the many initial inappropriate types of products. However, the exercise presentation in the first week improved the level of understanding regarding their purposes and the method of design. In general, students agreed on the benefits of their help in providing a deep understanding of the cases and the possibility of solving clinical problems efficiently. The commentary was helpful in evaluating the truthfulness of their efforts. Students gave suggestions for increasing the percentage of their scores, considering the efforts.

CONCLUSION

Using multiple types of visual educational tools during PBL can be useful in understanding the diverse routes of clinical reasoning and clinical features.

Multimodality imaging in vivo for preclinical assessment of tumor-targeted doxorubicin nanoparticles

This study presents a new multimodal imaging approach that includes high-frequency ultrasound, fluorescence intensity, confocal, and spectral imaging to improve the preclinical evaluation of new therapeutics in vivo. Here we use this approach to assess in vivo the therapeutic efficacy of the novel chemotherapy construct, HerDox during and after treatment. HerDox is comprised of doxorubicin non-covalently assembled in a viral-like particle targeted to HER2+ tumor cells, causing tumor cell death at over 10-fold lower dose compared to the untargeted drug, while sparing the heart. Whereas our initial proof-of-principle studies on HerDox used tumor growth/shrinkage rates as a measure of therapeutic efficacy, here we show that multimodal imaging deployed during and after treatment can supplement traditional modes of tumor monitoring to further characterize the particle in tissues of treated mice. Specifically, we show here that tumor cell apoptosis elicited by HerDox can be monitored in vivo during treatment using high frequency ultrasound imaging, while in situ confocal imaging of excised tumors shows that HerDox indeed penetrated tumor tissue and can be detected at the subcellular level, including in the nucleus, via Dox fluorescence. In addition, ratiometric spectral imaging of the same tumor tissue enables quantitative discrimination of HerDox fluorescence from autofluorescence in situ. In contrast to standard approaches of preclinical assessment, this new method provides multiple/complementary information that may shorten the time required for initial evaluation of in vivo efficacy, thus potentially reducing the time and cost for translating new drug molecules into the clinic.

Prevalence and different characteristics of two serotypes of Streptococcus parauberis isolated from the farmed olive flounder, Paralichthys olivaceus (Temminck and Schlegel), in Korea

The prevalence of two serotypes of Streptococcus parauberis isolated from the olive flounder, Paralichthys olivaceus, was evaluated in a total of 29 isolates between 2003 and 2010 in Korea. Streptococcus parauberis isolates were divided into two serologically distinct types (serotype 1 and serotype 2), except for one strain (S1091), using an agglutination assay with rabbit antiserum, and serotype 1 was identified as the dominant type (24 of 29 isolates) in this study. To identify the characteristics of the two serotypes of S. parauberis, we conducted a biochemical test using the API 20 Strep kit, a transmission electron microscopy (TEM) assay, sequence analysis of 16S-23S rRNA intergenic spacer region (ISR) and a pathogenicity test. In TEM, both serotypes possessed polysaccharide capsule layers around the cell surface when bacterial cells were treated with a homologous serotype of rabbit antiserum. However, we were unable to discriminate serotype-specific biochemical characteristics and genetic characteristics of 16S-23S rRNA ISR between the two serotypes. In the pathogenicity test, the serotype 1 strains induced significantly higher mortality than the serotype 2 strains in olive flounder when experimentally inoculated via the intraperitoneal route.

Acceptable compression ratio of full-field digital mammography using JPEG 2000

AIM

To estimate the acceptable compression ratio of full-field digital mammography (FFDM) using the Joint Photographic Experts Group (JPEG) 2000 compression algorithm.

MATERIALS AND METHODS

Eighty cases that included images of 40 masses (20 benign, 20 malignant) and 40 microcalcifications (20 benign, 20 malignant) were collected. The images were compressed to five different lossy ratios: 20:1, 40:1, 60:1, 80:1, and 100:1, and four radiologists independently determined whether the compressed group was distinguishable from the control group. The ratio of the compressed group that was rated indistinguishable from the control group was compared for each reviewer, and the results were analysed for agreements of three or more reviewers.

RESULTS

The ability to distinguish the compressed image from the control group is given as a range across the four reviewers: 0-1.3% (0/80 to 1/80) of the 20:1, 0-2.5% (0/80 to 2/80) of the 40:1, 5-7.5% (4/80 to 6/80) of the 60:1, 10-37.5% (8/80 to 30/80) of the 80:1, and 30-87.5% (24/80 to 70/80) of the 100:1. For three compression groups (20:1, 40:1, and 60:1), three or more reviewers agreed that there was a distinguishable difference for 0/80, 0/80, and 3/80 images, respectively. Thus, the compressed images do not differ significantly from the control group (p>0.05). However, the 80:1 and 100:1 compressed images were different for 9/80 and 29/80 images, respectively, which is significantly different from the control group (p<0.05).

CONCLUSION

The lossy 60:1 compression ratio for FFDM is visually identical to the control image and, therefore, potentially acceptable for primary interpretation.

The correlation between the effects of propofol on the auditory brainstem response and the postsynaptic currents of the auditory circuit in brainstem slices in the rat

BACKGROUND

Although there have been reports showing the changes of the auditory brainstem response (ABR) waves by propofol, no detailed studies have been done at the level of brainstem auditory circuit. So, we studied the effects of propofol on the postsynaptic currents of the medial nucleus of the trapezoid body (MNTB)-lateral superior olive (LSO) synapses by using the whole cell voltage clamp technique and we compared this data with that obtained by the ABR.

METHODS

5 rats at postnatal (P) 15 days were used for the study of the ABR. After inducing deep anesthesia using xylazine 6 mg/kg and ketamine 25 mg/kg, the ABRs were recorded before and after intraperitoneal propofol injection (10 mg/kg) and the effects of propofol on the latencies of the I, III, and V waves and the I-III and III-V interwave intervals were evaluated. Rats that were aged under P11 were used in the voltage clamp experiments. After making brainstem slices, the postsynaptic currents (PSCs) elicited by MNTB stimulation were recorded at the LSO, and the changes of the PSCs by the bath application of propofol (100 microM) were monitored.

RESULTS

We found small, but statistically significant increases in the latencies of ABR waves III and V and the interwave intervals of I-III and III-V by propofol. However, no significant changes were observed in the glycinergic or glutamatergic PSCs of the MNTB-LSO synpases by the application of propofol (100 microM).

CONCLUSIONS

Glycinergic or glutamatergic transmission of the MNTB-LSO synapses might not contribute to the propofol-induced changes of the ABR.

Students' Response to the Questionnaire about the Usefulness of Concept Maps for Problem-Based Learning and the Forms of Concept Maps

PURPOSE

Concept maps have been studied and used in diverse ways in scientific fields. This study aimed to investigate the usefulness and limitations of using concept maps during problem-based learning (PBL) in Year 3 medical students.

METHODS

After each PBL module, we gathered concept maps from each pair of students and questionnaires about the usefulness and limitations of concept maps, and analyzed them.

RESULTS

There were two types of concept maps, with some modifications. The students felt that concept maps provided overall understanding, analysis, and reorganization of problem cases. But, they also criticized shortage of disciplines related to drawing skills and rationales for each type of map. A strong need for expert maps and feedback for students resulted.

CONCLUSION

For optimal use of concept maps, we recommend that the committee implements a plan to teach drawing skills, explains rationales for each type of map, and gives feedback to students.

Central nervous system distribution of the transcription factor Phox2b in the adult rat

Phox2b is required for development of the peripheral autonomic nervous system and a subset of cranial nerves and lower brainstem nuclei. Phox2b mutations in man cause diffuse autonomic dysfunction and deficits in the automatic control of breathing. Here we study the distribution of Phox2b in the adult rat hindbrain to determine whether this protein is selectively expressed by neurons involved in respiratory and autonomic control. In the medulla oblongata, Phox2b-immunoreactive nuclei were present in the dorsal vagal complex, intermediate reticular nucleus, dorsomedial spinal trigeminal nucleus, nucleus ambiguus, catecholaminergic neurons, and retrotrapezoid nucleus (RTN). Phox2b was expressed by both central excitatory relays of the sympathetic baroreflex (nucleus of the solitary tract and C1 neurons) but not by the inhibitory relay of this reflex. Phox2b was absent from the ventral respiratory column (VRC) caudal to RTN and rare within the parabrachial nuclei. In the pons, Phox2b was confined to cholinergic efferent neurons (salivary, vestibulocochlear) and noncholinergic peritrigeminal neurons. Rostral to the pons, Phox2b was detected only in the oculomotor complex. In adult rats, Phox2b is neither a comprehensive nor a selective marker of hindbrain autonomic pathways. This marker identifies a subset of hindbrain neurons that control orofacial movements (dorsomedial spinal trigeminal nucleus, pontine peritrigeminal neurons), balance and auditory function (vestibulocochlear efferents), the eyes, and both divisions of the autonomic efferent system. Phox2b is virtually absent from the respiratory rhythm and pattern generator (VRC and dorsolateral pons) but is highly expressed by neurons involved in the chemical drive and reflex regulation of this oscillator.

Structural and expression analyses of two vitellogenin genes in the carp, Cyprinus carpio

We cloned and sequenced two vitellogenin (vg) cDNAs of the carp, Cyprinus carpio, using a cDNA library constructed from estradiol-17 beta (E2)-treated livers. One was a novel, longer 5000 bp-long cDNA termed vg-B2 encoding 1624 amino acids in a single open reading frame. The other was a shorter cDNA (vg-B1), identical to that registered previously as carp vg cDNA in the international nucleotide sequence database. The deduced amino acid sequences of these two molecules were well-aligned with known vertebrate Vgs sharing common characteristics such as N-terminal lipovitellin I (LVI), phosvitin (PV) and C-terminal lipovitellin II (LVII). The novel Vg-B2 bore a highly conserved GL/ICG motif within the LVII region, in contrast to the shorter Vg-B1 that has a truncated C-terminal and lacks the beta-component within the LVII region including the GL/ICG motif. Both vg-B2 and vg-B1 genes were expressed in the livers of females and E2-injected males. Western blot analysis using anti-Vg and anti-vitellin (Vn) antisera demonstrated that both Vg-B2 and Vg-B1 were detected as polypeptides with an estimated molecular mass of 180 kDa and 160 kDa, respectively, in the blood of females and E2-injected males. The results suggest the potential utilization of these genes as sensitive xenoestrogenic markers.

Expression of Phox2b by brainstem neurons involved in chemosensory integration in the adult rat

Central congenital hypoventilation syndrome is caused by mutations of the gene that encodes the transcription factor Phox2b. The syndrome is characterized by a severe form of sleep apnea attributed to greatly compromised central and peripheral chemoreflexes. In this study, we analyze whether Phox2b expression in the brainstem respiratory network is preferentially associated with neurons involved in chemosensory integration in rats. At the very rostral end of the ventral respiratory column (VRC), Phox2b was present in many VGlut2 (vesicular glutamate transporter 2) mRNA-containing neurons. These neurons were functionally identified as the respiratory chemoreceptors of the retrotrapezoid nucleus (RTN). More caudally in the VRC, many fewer neurons expressed Phox2b. These cells were not part of the central respiratory pattern generator (CPG), because they were typically cholinergic visceral motor neurons or catecholaminergic neurons (presumed C1 neurons). Phox2b was not detected in serotonergic neurons, in the A5, A6, and A7 noradrenergic cell groups nor within the main cardiorespiratory centers of the dorsolateral pons. Phox2b was expressed by many solitary tract nucleus (NTS) neurons including those that relay peripheral chemoreceptor information to the RTN. These and previous observations by others suggest that Phox2b is expressed by an uninterrupted chain of neurons involved in the integration of peripheral and central chemoreception (carotid bodies, chemoreceptor afferents, chemoresponsive NTS neurons projecting to VRC, RTN chemoreceptors). The presence of Phox2b in this circuit and its apparent absence from the respiratory CPG could explain why Phox2b mutations disrupt breathing automaticity during sleep without causing major impairment of respiration during waking.

Re-circulation artefact at the carotid bulb can be differentiated from true stenosis

Re-circulation artefact developing secondary to vortex flow at the bulb of the internal carotid artery is very difficult to distinguish from true stenotic defect on two-dimensional Fourier transformed time-of-flight magnetic resonance angiography (2D-FT TOF MRA). The purpose of our study is to identify appropriate distinguishing features of re-circulation artefact. We included 45 extracranial carotid arteries collected from 25 patients who underwent both 2D-FT TOF MRA and contrast medium based angiography. Review of the 45 vessels demonstrated re-circulation artefact in 21 vessels, true stenotic defect in 8 vessels, and no filling defect in 16 vessels on 2D-FT TOF MRA. We compared the findings of re-circulation artefact and true stenotic defect in 29 vessels excluding the 16 vessels without filling defect. The following were evaluated: (1) preservation of posterior wall contour; (2) marginal character of filling defect; (3) darkness of filling defect; (4) involvement of common carotid artery by filling defect; (5) size of filling defect. In four out of the five evaluated items, statistically significant difference was present between re-circulation artefact group and true stenotic defect group (p<0.01 in all four items, chi(2) analysis). Re-circulation artefact demonstrated the preservation of the posterior wall contour (19/21), ill-defined margin (19/21), less dark defect (18/21), and no involvement of the common carotid artery (19/21). On the contrary true stenotic defect demonstrated focal loss of posterior wall contour (8/8), sharp margin (8/8), dark defect (8/8), and involvement of common carotid artery (4/8). No significant difference was noted in the size of the defect between the two groups (p>0.05). The specificity of 2D-FT TOF MRA for carotid stenosis was markedly increased after application of above signs. These distinguishing signs are very helpful in differentiating re-circulation artefact from true stenotic defect.

Noncompetitive inhibition by camphor of nicotinic acetylcholine receptors

The effect of camphor, a monoterpenoid, on catecholamine secretion was investigated in bovine adrenal chromaffin cells. Camphor inhibited [3H]norepinephrine ([3H]NE) secretion induced by a nicotinic acetylcholine receptor (nAChR) agonist, 1,1-dimethyl-4-phenylpiperazinium iodide (DMPP), with a half-maximal inhibitory concentration (IC50) of 70 +/- 12 microM. In addition, camphor inhibited the rise in cytosolic calcium ([Ca2+]i) and sodium ([Na+]i) induced by DMPP with IC50 values of 88 +/- 32 and 19 +/- 2 microM, respectively, suggesting that the activity of nAChRs is also inhibited by camphor. On the other hand, binding of [3H]nicotine to nAChRs was not affected by camphor. [Ca2+]i increases induced by high K+, veratridine, and bradykinin were not affected by camphor. The data suggest that camphor specifically inhibits catecholamine secretion by blocking nAChRs without affecting agonist binding.

Can the expression of histocompatibility antigen be changed by lithium?

OBJECTIVES

This study attempted to determine whether human leukocyte antigen (HLA) type changes would be caused by lithium.

METHODS

A total of 15 patients were chosen as subjects (4 males, 11 females) and completed tests in class I. Eight of the 15 patients completed tests in class II. Their mean age was 27 +/- 7 years. For an average of 51 +/- 17 days, lithium, 600-1,200 mg/day (mean daily dose: 920 +/- 211 mg) was administered for the HLA testing and then compared with the HLA type prior to the time the drug was administered. Class I type test was performed according to the Terasaki microcytotoxicity method and class II type by the Erlich polymerase chain reaction method.

RESULTS

Of the 15 subjects, 11 had changes in HLA-A, B, C types and two of the eight subjects had changes in HLA DR type.

CONCLUSION

Lithium, in the therapeutic dose, is considered to bring about changes in HLA expressions in as short a time period as 2 months.

Methylation controls the low temperature induction of flowering in Arabidopsis

Control of the transition to flowering is critical for reproductive success of a plant. Studies in Arabidopsis have led us to suggest how this species has harnessed the environmental cue of a period of low temperature to ensure flowering occurs at an appropriate time. We propose that Arabidopsis has both vernalization-independent and vernalization-dependent pathways for the initiation of inflorescence development in the shoot apex. The vernalization-independent pathway may be concerned with the supply of carbohydrate to the shoot apex. In late flowering ecotypes which respond to vernalization the vernalization-independent pathway is blocked by the action of two dominant repressors of flowering, FRI and FLC, which interact to produce very late flowering plants which respond strongly to vernalization. We have isolated a gene which may correspond to FLC. We suggest the vernalization-dependent pathway, which may be concerned with apical GA biosynthesis, is blocked by methylation of a gene critical for flowering. This gene may correspond to that encoding kaurenoic acid hydroxylase (KAH), an enzyme catalysing a step in the GA biosynthetic pathway. Under this scheme vernalization causes unblocking of this pathway by demethylation possibly of the KAH gene and consequent biosynthesis of active GAs in the apex.