Effects of hip joint kinematics on the effective pelvis stiffness and hip impact force during simulated sideways falls

Improved understanding is required on how hip fracture risk is influenced by landing configuration. We examined how hip impact dynamics was affected by hip joint kinematics during simulated sideways falls. Twelve young adults (7 males, 5 females) of mean age 23.5 (SD = 1.5) years, participated in pelvis release experiments. Trials were acquired with the hip flexed 15° and 30° for each of three hip rotations: +15° ("external rotation"), 0°, and -15° ("internal rotation"). During falls, force-deformation data of the pelvis were recorded. Outcome variables included the peak hip impact force (Fexperimental) and effective stiffness of the pelvis (k1st, ksecant, and kms) determined with different methods suggested in literature, and predicted hip impact force during a fall from standing height (F1st, Fsecant and Fms). The two-way repeated-measures ANOVA was used to test whether these variables were associated with hip joint angles. The Fexperimental, ksecant and Fsecant were associated with hip rotation (F = 5.587, p = 0.005; F = 9.278, p < 0.0005; F = 5.778, p = 0.004, respectively), and 15 %, 31 % and 17 % smaller in 15° external than internal rotation (848 versus 998 N; 24.6 versus 35.6 kN/m; 2,637 versus 3,170 N, respectively). However, none of the outcome variables were associated with hip flexion (p > 0.05). Furthermore, there were no interactions between the hip rotation and flexion for all outcome variables (p > 0.05). Our results provide insights on hip impact dynamics, which may help improve a hip model to assess hip fracture risk during a fall.

Punctuated growth of InAs quantum dashes-in-a-well for enhanced 2-μm emission

InAs quantum dashes (Qdash) engineered to emit near 2 μm are envisioned to be promising quantum emitters for next-generation technologies in sensing and communications. In this study, we explore the effect of punctuated growth (PG) on the structure and optical properties of InP-based InAs Qdashes emitting near the 2-μm wavelength. Morphological analysis revealed that PG led to an improvement in in-plane size uniformity and increases in average height and height distribution. A 2 × boost in photoluminescence intensity was observed, which we attribute to improved lateral dimensions and structural stabilization. PG encouraged formation of taller Qdashes while photoluminescence measurements revealed a blue-shift in the peak wavelength. We proposed that the blue-shift originates from the thinner quantum well cap and decreased distance between the Qdash and InAlGaAs barrier. This study on the punctuated growth of large InAs Qdashes is a step toward realizing bright, tunable, and broadband sources for 2-μm communications, spectroscopy, and sensing.

Effect of fall characteristics on the severity of hip impact during a fall on the ground from standing height

The magnitude of hip impact force during a fall on the ground (i.e., concrete surface) from standing height was determined. We found that this force decreases up to 59%, depending on how they land on the ground.

INTRODUCTION

We determined the magnitude of hip impact force that humans may experience in the event of a fall from standing height on the ground, in order to examine how the hip impact force was affected by characteristics of a fall.

METHODS

Twenty subjects mimicked a typical older adults' falls on a mat. Trials were acquired with three initial fall directions: forward, sideways, and backward. Trials were also acquired with three knee positions at the time of hip impact: knee together, knee on the mat, and free knee. During falls, attenuated vertical hip impact forces and corresponding depression of the mat were measured via a force plate placed under the mat and motion capture system, respectively. Using a mass-spring model, actual hip impact force and body stiffness during a fall on the ground were estimated.

RESULTS

Hip impact force averaged 4.0 kN (SD = 1.7). The hip impact force was associated with knee condition (F = 25.6, p < 0.005), but not with fall direction (F = 0.4, p = 0.599). Compared with "knee on the mat," hip impact force averaged 59% and 45% greater in "free knee" and "knee together," respectively (4.6 versus 2.9 kN, p < 0.005; 4.3 versus 2.9 kN, p < 0.005). However, the hip impact force did not differ between "free knee" and "knee together (4.6 versus 4.3 kN, p = 0.554).

CONCLUSION

Our results suggest that hip fracture risk during a fall decreases substantially, depending on how they land on the ground, informing the development of safe landing strategies to prevent fall-related hip fractures in older adults.

Effect of drug compliance on health care costs in newly-diagnosed dementia: a nation-wide analysis

Background

The cost-effectiveness of both cholinesterase inhibitors and memantine by delaying nursing home placement has been supported by numerous studies. The importance of sustained pharmacological treatment in dementia has been relatively less recognized by public health policies compared to early diagnosis. We investigated the effect of the drug (donepezil, rivastigmine, galantamine, and memantine) compliance on the health care costs in newly-diagnosed dementia.

Methods

National Health Insurance Service (NHIS) database which covers the entire population of South Korea was used for analysis. Health care expenditure of patients newly-diagnosed with dementia in between 2012 and 2014 was investigated for 3 to 5 years. For drug compliance, we used Medication Possession Ratio (MPR) that indicates the percentage of time a patient has access to medication. Multivariate linear regression analysis including generalized estimated equation and gamma distribution was used for statistical analysis.

Results

We identified 252,594 patients who were both prescribed with cognitive enhancers and newly diagnosed with dementia. When initial MPR increased 20%, total health care costs decreased 8.4% (RR = 0.916, 95%; CI 0.914 to 0.916). Same relationship was shown with medical costs related to dementia, admission to a general hospital, and emergency room visits. When MPR increased 20% compared to the previous year, the total health care costs, admission to a general hospital, emergency room visits, and admission to a nursing hospital decreased.

Conclusions

This population-based retrospective cohort study provides evidence that patients newly-diagnosed with dementia who showed higher initial drug compliance or maintained antidementia drugs (Cholinesterase inhibitors and memantine) would benefit in total health-care costs.

Key messages

Public health care policies should not only focus on early diagnosis in dementia, but also recognize the importance of adherence to cognitive enhancers. To maximize the positive pharmacoeconomic effect of early diagnosis of dementia, it is important to sustain adequate drug compliance to cognitive enhancers.

Evidence for a preformed Cooper pair model in the pseudogap spectra of a Ca10(Pt4As8)(Fe2As2)5 single crystal with a nodal superconducting gap

For high-T_c superconductors, clarifying the role and origin of the pseudogap is essential for understanding the pairing mechanism. Among the various models describing the pseudogap, the preformed Cooper pair model is a potential candidate. Therefore, we present experimental evidence for the preformed Cooper pair model by studying the pseudogap spectrum observed in the optical conductivity of a Ca₁₀(Pt₄As₈)(Fe₂As₂)₅ (T_c = 34.6 K) single crystal. We observed a clear pseudogap structure in the optical conductivity and observed its temperature dependence. In the superconducting (SC) state, one SC gap with a gap size of Δ = 26 cm⁻¹, a scattering rate of 1/τ = 360 cm⁻¹ and a low-frequency extra Drude component were observed. Spectral weight analysis revealed that the SC gap and pseudogap are formed from the same Drude band. This means that the pseudogap is a gap structure observed as a result of a continuous temperature evolution of the SC gap observed below T_c. This provides clear experimental evidence for the preformed Cooper pair model.

Abstract P4-08-22: Impact of application of AJCC 8th edition on survival rate of the breast cancer

Background

The AJCC 8 edition has changed much in comparison with the 7 edition. In addition to TNM stage, biologic marker (ER, PR, HER2), Histologic grade and multigene assays (oncotype Dx.) should be considered for staging. and it has been applied since January 1, 2018.

patients were recategorized and analyzed in order to know if this more complex classification helps to predict the real prognosis of the patients,

Method

We review patients who were diagnosed and treated as breast cancer at Konyang Universty Hospital. we studied retrospectively 582 patients who were followed up and were able to review.

Stage was classified according to AJCC 7th edition and AJCC 8th edition. survival rate of each stage were analyzed in both editions.

Result

Mean follow up period was 68.6 months. Total 582 patients were included. There was no change in the stage in 257 patients. In 195 patients, the stage was elevated and in 130 patients, the stage was changed down. When classified as AJCC 7th edition, the 5year-survival rate was 95.9% in stage I, 97.9% in stage II, 93.1% in stage III and 89.9% in stage IV. The survival rate of patients in stage I was lower than that of stage II. However, when the AJCC 8th edition was applied, the 5- year survival rate was 97.9% in stage I, 96.9% in stage II, 92.2% in stage III, and 89.9% in stage IV. In 8th edition, the patients in lower stage has higher survival rate.

Conclusion

The prediction of survival rate by stage was more accurate and the difference in survival rate of each stages was more clearly distinguished when The AJCC 8th edition was applied than AJCC 7th edition. AJCC 8th edition was reliable and useful for prediction of prognosis of breast cancer patient.

Citation Format: Kwon S, Yoon DS, Bae IE, Choi WJ, Choi IS, Lee SE, Moon JI, Sung NS, Park SM. Impact of application of AJCC 8th edition on survival rate of the breast cancer [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P4-08-22.

Effect of neck flexor muscle activation on impact velocity of the head during backward falls in young adults

Falls are a common cause of traumatic brain injuries (TBI) across the lifespan. A proposed but untested hypothesis is that neck muscle activation influences impact severity and risk for TBI during a fall. We conducted backward falling experiments to test whether activation of the neck flexor muscles facilitates the avoidance of head impact, and reduces impact velocity if the head contacts the ground. Young adults (n=8) fell from standing onto a 30cm thick gymnastics mat while wearing a helmet. Participants were instructed to fall backward and (a) prevent their head from impacting the mat ("no head impact" trials); (b) allow their head to impact the mat, but with minimal impact severity ("soft impact" trials); and (c) allow their head to impact the mat, while inhibiting efforts to reduce impact severity ("hard impact" trials). Trial type associated with peak magnitude of electromyographic activity of the sternocleidomastoid (SCM) muscles (p<0.017), and with the vertical and horizontal velocity of the head at impact (p<0.001). Peak SCM activations, expressed as percent maximal voluntary isometric contraction (%MVIC), averaged 75.3, 67.5, and 44.5%MVIC in "no head impact", "soft impact", and "hard impact" trials, respectively. When compared to "soft impact" trials, vertical impact velocities in "hard impact" trials averaged 87% greater (3.23 versus 1.73m/s) and horizontal velocities averaged 83% greater (2.74 versus 1.50m/s). For every 10% increase in SCM %MVIC, vertical impact velocity decreased 0.24m/s and horizontal velocity decreased 0.22m/s. We conclude that SCM activation contributes to the prevention and modulation of head impact severity during backward falls.

Inhibition of microRNA-449a prevents IL-1β-induced cartilage destruction via SIRT1

OBJECTIVE

SIRT1 has anti-inflammatory as well as protective effects in chondrocytes. The object of this study was to investigate whether microRNA-449a regulates expression of SIRT1, which inhibits expression of catabolic genes in IL-1β-induced cartilage destruction.

MATERIALS AND METHODS

MicroRNA-449a expression was determined in OA chondrocytes and IL-1β-induced chondrocytes by real-time PCR. MicroRNA-449a binding sites on the 3'-UTR of SIRT1 mRNA and binding site conservation were examined using microRNA target prediction tools. SIRT1-overexpressing or knockdown chondrocytes were transfected with microRNA-449a or anti-microRNA-449a mimic and stimulated by IL-1β. Expression of catabolic and anabolic genes was examined by real-time PCR and western blotting. Finally, positive effects of anti-microRNA-449a on expression of these genes were confirmed by western analysis of OA chondrocytes.

RESULTS

Expression of microRNA-449a was increased in OA chondrocytes and IL-1β-induced chondrocytes. MMP-13 expression was enhanced, whereas type II collagen and SIRT1 expression were decreased in IL-1β-induced chondrocytes. SIRT1 overexpression resulted in decreased expression of catabolic genes such as MMPs and ADAMTSs in response to IL-1β, but these effects were moderated by microRNA-449a. Suppression of microRNA-449a by anti-microRNA-449a inhibited expression of catabolic genes despite IL-1β stimulation, but these effects were abolished in SIRT1 knockdown chondrocytes. Furthermore, expression of catabolic genes was decreased and expression of type II collagen as well as SIRT1 was restored by anti-microRNA-449a in OA chondrocytes as well as in IL-1β-induced chondrocytes.

CONCLUSION

Silencing of microRNA-449a had a protective effect, inhibiting catabolic gene expression and restoring anabolic gene expression, by targeting SIRT1 in IL-1β-induced cartilage destruction.

A Mobile Application for Wound Assessment and Treatment: Findings of a User Trial

The D+Wound Solution is a mobile phone application (app) that assists users in the assessment and treatment of the wound. The app has 6 components for assessment: need for debridement, infection control, revascularization, and exudate control; whether it is chronic; and finally, the top surface of the skin. These components are named D.I.R.E.C.T. The app makes you review these components as an algorithm to provide a reasonable solution for dressing. It is designed to understand the status of the wound and provide a practical treatment idea for wound care providers. A total of 118 nurses were divided into 2 groups, designated as experienced and less-experienced groups, and surveyed. Both groups found the app to be helpful in making a treatment plan. However, the less-experienced group found it to be significantly more useful in assessing the wound ( P = .026) but difficult to understand the logic. The experienced group found the logic to be significantly easier to understand ( P = .018) and had significantly higher similarities ( P = .015) in treatment protocols compared with the less-experienced group. We may conclude that this app has a logical algorithm resembling experienced wound caregivers and is more useful in the less-experienced group.

Spinal Accessory Nerve: Ultrasound Findings and Correlations with Neck Lymph Node Levels

Purpose: To evaluate the ultrasound characteristics of the spinal accessory nerve (SAN) and correlate nerve location with neck lymph node level. Materials and Methods: 50 participants with 100 SANs were enrolled in this study. The SAN was traced from the trapezius muscle to the upper neck and was identified by a hypoechoic linear structure without color Doppler flow. The ultrasound characteristics of the SAN, such as visibility, diameter, relationship with adjacent structures, and its correlation with lymph node levels, were evaluated. Results: The SAN was identified in 96 %-100 % of segments. The mean diameter of the SAN was 0.54 ± 0.09 mm. The SANs was located between the trapezius and levator scapulae muscles and 90.8 % were traced into the trapezius muscle. In the upper neck, the SAN passed deep into the sternocleidomastoid (SCM) muscle in 38 % of cases and between the two heads of the SCM muscle in 62 % of cases. The SAN was found at neck lymph node levels II, III, IV, and V, but not I or VI. Conclusion: Continuous ultrasound monitoring of the SAN and its correlation with lymph node levels is possible in most patients. Our current findings may assist in the future prevention of SAN injury during ultrasound-guided procedures.

Effects of hip abductor muscle forces and knee boundary conditions on femoral neck stresses during simulated falls

Through experiments that simulated sideways falls with a mechanical hip impact simulator, we demonstrated the protective effect of hip abductor muscle forces in reducing peak stresses at the femoral neck and the corresponding risk for hip fracture.

INTRODUCTION

Over 90% of hip fractures are due to falls, and an improved understanding the factors that separate injurious and non-injurious falls (via their influence on the peak stress generated at the femoral neck) may lead to improved risk assessment and prevention strategies. The purpose of this study was to measure the effect of muscle forces spanning the hip, and knee boundary conditions, on peak forces and estimated stresses at the femoral neck during simulated falls with a mechanical system.

METHODS

We simulated hip abductor muscle forces and knee boundary conditions with a mechanical hip impact simulator and measured forces and stresses at the femoral neck during sideways falls.

RESULTS

Peak compressive and tensile stresses, shear force, bending moment, and axial force are each associated with hip abductor muscle forces and knee boundary conditions (p < 0.0005). When muscle force increased from 400 to 1,200 N, peak compressive and tensile stresses decreased 24 and 56%, respectively. These effects were similar to the magnitude of decline in fracture strength associated with osteoporosis and arose from the tension-band effect of the muscle in reducing the bending moment by 37%. Furthermore, peak compressive and tensile stresses averaged 40 and 51% lower, respectively, in the free knee than fixed knee condition.

CONCLUSIONS

Contraction of the hip abductor muscles at the moment of impact during a fall, and landing with the knee free of constraints, substantially reduced peak compressive and tensile stresses at the femoral neck and risk for femoral fracture in a sideways fall.

Age-related changes in dynamic compressive properties of trochanteric soft tissues over the hip

Hip fracture risk increases dramatically with age, and 90% of fractures are due to falls. During a fall on the hip, the soft tissues overlying the hip region (skin, fat, and muscle) act as shock absorbers to absorb energy and reduce the peak force applied to the underlying bone. We conducted dynamic indentation experiments with young women (aged 19-30; n=17) and older women (aged 65-81; n=17) to test the hypothesis that changes occur with age in the stiffness and damping properties of these tissues. Tissue stiffness and damping were derived from experiments where subjects lay sideways on a bed with the greater trochanter contacting a 3.8cm diameter indenter, which applied sinusoidal compression between 5 to 30Hz with a peak-to-peak amplitude of 1mm. Soft tissue thickness was measured using ultrasound. On average, stiffness was 2.9-fold smaller in older than young women (5.7 versus 16.8kN/m, p=0.0005) and damping was 3.5-fold smaller in older than young women (81 versus 282Ns/m, p=0.001). Neither parameter associated with soft tissue thickness. Our results indicate substantial age-related reductions in the stiffness and damping of soft tissues over the hip region, which likely reduce their capacity to absorb and dissipate energy (before "bottoming out") during a fall. Strategies such as wearable hip protectors or compliant flooringmay compensate for age-related reductions in the shock-absorbing properties of soft tissues and decrease the injury potential of falls.

Prediction of pathological complete response of breast cancer patients undergoing neoadjuvant chemotherapy: usefulness of breast MRI computer-aided detection

OBJECTIVE

To evaluate the usefulness of MR computer-aided detection (CAD) in patients undergoing neoadjuvant chemotherapy for prediction of the pathological complete response of tumours.

METHODS

148 patients with breast cancer (mean age, 47.3 years; range, 29-72 years) who underwent neoadjuvant chemotherapy were included in our study. They underwent MRI before and after neoadjuvant chemotherapy, and we reviewed the pathological result as the gold standard. The computer-generated kinetic features for each lesion were recorded, and the features analysed included "threshold enhancement" at 50% and 100% minimum thresholds; degree of initial peak enhancement; and enhancement profiles comprising lesion percentages of washout, plateau and persistent enhancement. The final pathological size and character of tumours were correlated with post-chemotherapy mammography, ultrasonography and MR CAD findings. Kruskal-Wallis test and intraclass correlation coefficient were used to analyse the findings.

RESULTS

We divided the 148 patients into complete pathological response and non-complete pathological response groups. A complete pathological response was defined as no histopathological evidence of any residual invasive cancer cells in the breast or axillary lymph nodes. 39 patients showed complete pathological response, and 109 patients showed non-complete pathological response. Between enhancement profiles of MR CAD, plateau proportion of tumours was significantly correlated with the pathological response of tumours (mean proportion of plateau on complete pathological response group was 27%, p = 0.007).

CONCLUSION

When plateau proportion of tumours is high, we can predict non-complete pathological response of neoadjuvant chemotherapy.

ADVANCES IN KNOWLEDGE

MR CAD can be a useful tool for the assessment of response to neoadjuvant chemotherapy and prediction of pathological results.

Superconducting properties of hole doped Ba(0.6)Li(0.4)Fe2As2 single crystal

We report the emergence of superconductivity in Li doped Ba-122 single crystals grown by the Bridgman method. The superconducting transition temperature Tc,onset is around 19 K. The specific heat capacity C/T shows a weak anomaly near Tc. The value of ΔC/γnTc is smaller than the value predicted in BCS theory indicating a multigap nature of the sample. The magnetic measurements show that the lower critical field Hc1(T) exhibits a linear temperature dependence, with a pronounced change of the Hc1(T) curvature around 0.4Tc and Hc1(0) ≈ 430 Oe in the Ba0.6Li0.4Fe2As2 single crystal. Furthermore, temperature dependence of the penetration depth λ(T) follows a power law (~T(n)) below 0.4Tc which predicts possible S±-wave pairing in a Ba0.6Li0.4Fe2As2 superconductor. Over a wide range of temperatures, the Jc(H) exhibits a relation J(c)[proportionality] H(-α) with α = 0.5 ~ 0.6 for H || c and H || ab which indicates random defects in the sample. We found that the temperature dependence of the critical current density Jc(T) can be fitted well with the δl-type pinning model, whose origin is attributed to spatial variations of charge carrier mean free path l. We suggest that the large mismatch in the ionic radius of Ba and Li can affect the irreversible magnetic properties of the Ba0.6Li0.4Fe2As2 single crystal without any structural transition.

Fabrication of GaAs/Al0.3Ga0.7As multiple quantum well nanostructures on (100) si substrate using a 1-nm InAs relief layer

Nanometer scale thin InAs layer has been incorporated between Si (100) substrate and GaAs/Al0.3Ga0.7As multiple quantum well (MQW) nanostructure in order to reduce the defects generation during the growth of GaAs buffer layer on Si substrate. Observations based on atomic force microscopy (AFM) and transmission electron microscopy (TEM) suggest that initiation and propagation of defect at the Si/GaAs interface could be suppressed by incorporating thin (1 nm in thickness) InAs layer. Consequently, the microstructure and resulting optical properties improved as compared to the MQW structure formed directly on Si substrate without the InAs layer. It was also observed that there exists some limit to the desirable thickness of the InAs layer since the MQW structure having thicker InAs layer (4 nm-thick) showed deteriorated properties.

Effect of growth temperature and quantum structure on InAs/GaAs quantum dot solar cell

InGaAs-capped InAs quantum dots (QDs) and InAs QDs were adopted for the study of the effects through growth temperature and the band structure of InAs QDs on the performance of GaAs-based QD solar cell. It has been shown that the defects due to low temperature growth resulted in the decrease of Voc, Jsc and external quantum efficiency for GaAs bulk solar cell and QD embedded solar cells. It has been also found that InAs QDs act as defects by trapping photo-generated carries which affect the carrier transport in QD solar cell. The QD solar cell with InGaAs-capped InAs QDs showed higher performance than the QD solar cell with only InAs QDs. Such result has been explained by photo-generated carrier trapping and tunneling through InGaAs QW state in InGaAs-capped InAs QDs.

Vertical growth of core-shell III-V nanowires for solar cells application

High density (In)GaAs/GaAs/AIGaAs nanowires (NWs) consisting of n-type core and p-type shell have been vertically grown on (111) GaAs substrate using metal organic chemical vapor deposition (MOCVD) and fabricated into solar cells. Au colloidal nanoparticles (NPs) are employed as a catalyst. High density nanowires were obtained by uniform distribution of Au NPs. Fe-SEM, TEM and HRTEM images show that the morphology of shell is sensitive to p-doping concentration. Increase in the density of p-doping precursor results in "kinking" of NPs and rough shell surface. The origin of kinking has been explained by the GaAs twin phases due to Zn segregation on the surface of shell. It has been observed that the morphology of NPs can be controlled through optimizing various source purge technique of DEZn and deposition temperature. Electrical properties of core-shell doped NWs are carried out using I-V characterization. The core-shell NWs show characteristics of p-n junction as revealed by I-V studies.

Increased NFAT5 expression stimulates transcription of Hsp70 in preeclamptic placentas

OBJECTIVE

We investigated the expression of heat shock protein 70 (Hsp70), nuclear factor of activated T cells 5 (NFAT5), and hypoxia-induced factor-1α (HIF-1α) in the placentas of normal and preeclamptic pregnancies and in human placental hypoxia models in vitro to examine the regulatory mechanisms of placental Hsp70 expression.

METHODS

The expression levels of HIF-1α, NFAT5, and Hsp70 were examined in placental samples from 10 females with preeclampsia and 10 normotensive control patients and in human choriocarcinoma trophoblast cells treated with 1 mM CoCl2 by western blotting. Using models of placental hypoxia, pharmacological inhibition of HIF-1α with chetomin and shRNA knockdown and overexpression of NFAT5 were performed to investigate the roles of HIF-1α and NFAT5 in induction of Hsp70 by placental hypoxia.

RESULTS

The levels of HIF-1α, NFAT5, and Hsp70 expression were significantly higher in the preeclamptic compared to normal placentas. In the placental hypoxia models, the expression of HIF-1α, NFAT5, and Hsp70 were significantly higher after 3, 6, and 12 h of 1 mM CoCl2 treatment, respectively. Pharmacological inhibition of HIF-1α suppressed the induction of NFAT5 and Hsp70 at the protein level. shRNA knockdown of NFAT5 suppressed the induction of Hsp70 protein and overexpression of NFAT5 stimulated the induction of Hsp70 mRNA and protein in models of human placental hypoxia in vitro.

CONCLUSION

HIF-1α positively regulates the induction of NFAT5 and Hsp70 by placental hypoxia and NFAT5 stimulates transcription of Hsp70 in response to placental hypoxia in models of human placental hypoxia in vitro.

Residual pain due to soft-tissue impingement after uncomplicated total ankle replacement

We report the incidence and intensity of persistent pain in patients with an otherwise uncomplicated total ankle replacement (TAR). Arthroscopic debridement was performed in selected cases and the clinical outcome was analysed. Among 120 uncomplicated TARs, there was persistent pain with a mean visual analogue scale (VAS) of 2.7 (0 to 8). The intensity of pain decreased in 115 ankles (95.8%). Exercise or walking for more than 30 minutes was the most common aggravating factor (62 ankles, 68.1%). The character of the pain was most commonly described as dull (50 ankles, 54.9%) and located on the medial aspect of the joint (43 ankles, 47.3%). A total of seven ankles (5.8%) underwent subsequent arthroscopy. These patients had local symptoms and a VAS for pain ≥ 7 on exertion. Impingement with fibrosis and synovitis was confirmed. After debridement, the median VAS decreased from 7 to 3 and six patients were satisfied. The median VAS for pain and the American Orthopaedic Foot and Ankle Society score of the ankles after debridement was similar to that of the uncomplicated TARs (p = 0.496 and p = 0.066, respectively). Although TAR reduces the intensity of pain, residual pain is not infrequent even in otherwise uncomplicated TARs and soft-tissue impingement is the possible cause.

Ultrasonographic investigation of the effect of positive end-expiratory pressure on the cross-sectional area of the femoral vein

Femoral veins are commonly used as a relatively safe alternative route for central venous cannulation. Several maneuvers are used to increase the cross-sectional area of the vein. In this study, we assessed the effect of positive end-expiratory pressure (PEEP) on the cross-sectional area (CSA) of femoral veins, using ultrasound in adult patients under positive pressure ventilation. All patients received a standardized induction of general anesthesia and intravenous fluid administration. Using ultrasound, the cross-sectional areas of both femoral veins were measured in 57 adult patients in the supine position without PEEP (control) and in the supine position with PEEP of 10 cm H(2)O. Mean arterial pressure and heart rate were recorded before and after the application of PEEP at 10 cm H(2)O. The application of 10 cm H(2)O PEEP significantly increased the CSA of the right femoral vein by 47.6 % and the left femoral vein by 48.4 % (each P < 0.001). Mean arterial pressure decreased by 2.6 mmHg (95 % CI 1.3-3.9; P < 0.001), whereas no significant change in heart rate was observed (P = 0.861). The CSA of the femoral vein is augmented with the application of 10 cm H(2)O PEEP in adult patients undergoing positive pressure ventilation.

Effect of pre-exposure to sevoflurane on the bispectral index in women undergoing Caesarean delivery under general anaesthesia

BACKGROUND

Patients undergoing Caesarean delivery under inhalation anaesthesia are at a high risk of awareness, especially in the period before delivery. We assessed the effects of pre-exposure to sevoflurane on the bispectral index (BIS) in the interval before delivery.

METHODS

Sixty-four patients undergoing elective Caesarean delivery were randomly assigned to receive 1.0-1.1 vol% (control 1) or 1.2-1.3 vol% (control 2) end-tidal sevoflurane, or the same concentrations of end-tidal sevoflurane combined with pre-exposure to 1 vol% sevoflurane for the last 1 min of the preoxygenation period (the preSevo 1 and preSevo 2 groups, respectively). We assessed BIS values, arterial pressure, and heart rate at the time of induction; before intubation; and upon skin incision, uterine incision, and delivery. We also determined the maternal incidence of intraoperative awareness and the neonatal Apgar scores, and conducted umbilical blood gas analysis.

RESULTS

At skin incision, BIS values were significantly lower in the preSevo 1 group than in the control 1 group [50 (13) vs 72 (8), P<0.001] and in the preSevo 2 group than in the control 2 group [44 (11) vs 67 (10), P<0.001]. The mean BIS values in the preSevo 1 and 2 groups were maintained below 60 in the period before delivery. No other parameter differed among groups, and no patient exhibited intraoperative awareness.

CONCLUSIONS

Pre-exposure to low concentrations of sevoflurane reduced BIS values in the interval before delivery, suggesting that this approach may reduce the risk of maternal awareness. Clinical Research Information Service (code KCT0000069, http://cris.cdc.go.kr).

Heterotopic ossification after total ankle arthroplasty

We evaluated the incidence of heterotopic ossification following total ankle replacement to determine whether the degree of ossification was associated with the clinical outcome. We evaluated 90 ankles in 81 consecutive patients who underwent total ankle replacement, and heterotopic ossification was assessed according to proportional involvement of the ankle joint. Correlation analysis was used to investigate the association between heterotopic ossification and outcome. No significant association was found between the formation of heterotopic ossification and the clinical outcome. The degree of heterotopic ossification in the posterior ankle joint was not significantly correlated with posterior ankle pain (p = 0.929), the American Orthopaedic Foot and Ankle Society score (p = 0.454) or range of movement (p = 0.283). This study indicates that caution should be observed in attributing symptoms and functional limitation to the presence of heterotopic ossification in the posterior ankle joint when considering excision of heterotopic bone after total ankle replacement.

Pressure distribution over the palm region during forward falls on the outstretched hands

Falls on the outstretched hands are the cause of over 90% of wrist fractures, yet little is known about bone loading during this event. We tested how the magnitude and distribution of pressure over the palm region during a forward fall is affected by foam padding (simulating a glove) and arm configuration, and by the faller's body mass index (BMI) and thickness of soft tissues over the palm region. Thirteen young women with high (n=7) or low (n=6) BMI participated in a "torso release experiment" that simulated falling on both outstretched hands with the arm inclined either at 20° or 40° from the vertical. Trials were acquired with and without a 5 mm thick foam pad secured to the palm. Outcome variables were the magnitude and location of peak pressure (d, θ) with respect to the scaphoid, total impact force, and integrated force applied to three concentric areas, including "danger zone" of 2.5 cm radius centered at the scaphoid. Soft tissue thickness over the palm was measured by ultrasound. The 5mm foam pad reduced peak pressure, and peak force to the danger zone, by 83% and 13%, respectively. Peak pressure was 77% higher in high BMI when compared with low BMI participants. Soft tissue thickness over the palm correlated positively with distance (d) (R=0.79, p=0.001) and force applied outside the danger zone (R=0.76, p=0.002), but did not correlate with BMI (R=0.43, p=0.14). The location of peak pressure was shunted 4 mm further from the scaphoid at 20° than that of 40° falls (d=25 mm (SD 8), θ=-9° (SD 17) in the 20° falls versus d=21 mm (SD 8), θ=-5° (SD 24) in the 40° falls). Peak force to the entire palm was 11% greater in 20° compared with 40° falls. These results indicate that even a 5 mm thick foam layer protects against wrist injury, by attenuating peak pressure over the palm during forward falls. Increased soft tissue thickness shunts force away from the scaphoid. However, soft tissue thickness is not predicted by BMI, and peak pressures are greater in high individuals than that of low BMI individuals. These results contribute to our understanding of the mechanics and prevention of wrist and hand injuries during falls.

Implementation and performance evaluation of mobile ad hoc network for Emergency Telemedicine System in disaster areas

So far we have developed Emergency Telemedicine System (ETS) which is a robust system using heterogeneous networks. In disaster areas, however, ETS cannot be used if the primary network channel is disabled due to damages on the network infrastructures. Thus we designed network management software for disaster communication network by combination of Mobile Ad hoc Network (MANET) and Wireless LAN (WLAN). This software maintains routes to a Backbone Gateway Node in dynamic network topologies. In this paper, we introduce the proposed disaster communication network with management software, and evaluate its performance using ETS between Medical Center and simulated disaster areas. We also present the results of network performance analysis which identifies the possibility of actual Telemedicine Service in disaster areas via MANET and mobile network (e.g. HSDPA, WiBro).

Effect of hip protectors, falling angle and body mass index on pressure distribution over the hip during simulated falls

BACKGROUND

We examined how a soft shell hip protector affects the magnitude and distribution of force to the hip during simulated falls, and how the protective effect depends on the fall direction and the amount of soft tissue padding over the hip.

METHODS

Fourteen young women with either high or low body mass index participated in a "pelvis release experiment" that simulated falls resulting in either lateral, anterolateral or posterolateral impact to the pelvis with/without a soft shell hip protector. Outcome variables were the magnitude and location of peak pressure (d, theta) with respect to the greater trochanter, total impact force, and percent force applied to four defined hip regions.

FINDINGS

The soft shell hip protector reduced peak pressure by 70%. The effect was two times greater in low than high body mass index individuals. The protector shunted the peak pressure distally along the shaft of the femur (d=52 mm (SD 22), theta=-21 degrees (SD 49) in the unpadded trials versus d=81 mm (SD 23), theta=-10 degrees (SD 35) in the padded trials). Peak force averaged 12% greater in posterolateral and 17% lower in anterolateral than lateral falls.

INTERPRETATION

Our results indicate that the hip protector we tested had a much stronger protective benefit for low than high body mass index individuals. Next generation protectors might be developed for improved shunting of pressure away from the femur, improved protection during posterolateral falls, and greater force attenuation for low body mass index individuals.

Cerebral epidural hematoma following cerebrospinal fluid drainage during thoracoabdominal aortic repair

Cerebrospinal fluid (CSF) drainage is a common adjunct to thoracoabdominal aortic aneurysm (TAAA) repair. CSF drainage may improve perioperative spinal cord perfusion and thereby decrease the incidence of paraplegia or paraparesis. Complications of CSF drainage may arise. We present a case of cerebral epidural hematoma (EDH), possibly arising from excessive CSF drainage, during thoracoabdominal aortic repair.

PKC delta in preeclamptic placentas promotes Bax dissociation from 14-3-3 zeta through 14-3-3 zeta phosphorylation

OBJECTIVE

We investigated placental apoptosis and the expression of and interactions between 14-3-3 and Bcl-2 family proteins during preeclampsia. In addition, we explored the mechanism of Bax dissociation from 14-3-3, hypothesizing that PKC-mediated phosphorylation of 14-3-3 results in dissociation of Bax from 14-3-3 proteins, and leads to apoptosis.

METHODS

Placental samples from 10 women with preeclampsia and 10 normotensive control patients were analyzed using M30-specific immunohistochemistry to assess placental apoptosis. Biochemical markers of cellular apoptosis, such as cleaved caspase-3, Bax, Bcl-2, 14-3-3, and PKC were followed by Western blotting. Interaction of 14-3-3 proteins with Bax and with PKC was assessed by immunoprecipitation.

RESULTS

M30-positive cells were widespread in the preeclamptic placentas. The levels of cleaved caspase-3, Bax, 14-3-3 zeta, phospho-(Ser)-14-3-3, and PKC delta were significantly higher in the preeclamptic placentas than in normal placentas. Preeclampsia was also associated with weaker interactions between 14-3-3 zeta and Bax and stronger interactions between 14-3-3 zeta and PKC delta.

CONCLUSION

Our results suggest that PKC delta in preeclamptic placentas promotes Bax dissociation from 14-3-3 zeta through the phosphorylation of 14-3-3 zeta. This finding may at least in part explain the apoptosis-inducing activity of PKC delta, revealing the important role of PKC delta in the development of apoptosis-related diseases such as preeclampsia.

The influence of head rotation on ProSeal laryngeal mask airway sealing during paediatric myringotomy

Myringotomy with ventilation tube insertion in children involves turning the head from neutral to allow surgical access to the ear. In adults, rotation of the head from the mid-line generally increases the oropharyngeal leak pressure when a ProSeal laryngeal mask airway (PLMA) is used to manage the airway. There are concerns that these manoeuvres may distort or obstruct the paediatric airway. Paediatric sizes (1.5, 2.0 and 2.5) of the PLMA differ from the adult versions in that they do not have a dorsal cuff. This study examines the effect of these head position changes on the seal of the PLMA in children. Twenty-nine children (ASA 1-2, aged 0.9 to 7.5 years) scheduled for myringotomy were recruited. After PLMA insertion, oropharyngeal leak pressure and fibreoptic determined PLMA position scores were measured in the neutral position and with head rotation of 45 degrees to the left or right. Fibreoptic positioning scores were similar in all positions. Head rotation was associated with a statistically significant but modest increase in oropharyngeal leak pressure versus the neutral position (P < 0.05). After rotating the head from neutral, 38% (11 of 29) of subjects had an increase of oropharyngeal leak pressure of at least 2 cmH2O. Only 7% (2 of 29) of subjects had a decrease in oropharyngeal leak pressure with head rotation, the maximum decrease being 2 cmH2O. Airway obstruction did not occur in any of the positions. We conclude that the efficacy of the seal for the pediatric sizes PLMA is improved by head rotation for myringotomy.

Production of optically active ketoprofen by direct enzymatic esterification

For the production of optically active ketoprofen, enzymatic resolution of racemic ketoprofen in an organic solvent has been accomplished via enantioselective esterification. Pharmacologically inactive (R)-ketoprofen is converted into the corresponding (R)-ester by this method. Enantioselectivity in lipase-catalyzed resolution of racemic ketoprofen was mainly dependent on the sources of lipase, alcohol moiety, organic solvent, and water content. Ethanol was used as the alkyl donor and the optimum water content required for highly efficient enzymatic resolution was determined to be 0.1-0.15% (v/v), which was maintained using salt hydrates such as Na2SO4 x 10H2O. (S)-Ketoprofen could be obtained with high enantioselectivity (E=15) in n-hexane supplemented with ethylene dichloride (20% (v/v)) using commercially available Candida antarctica lipase (Novozym 435).

Production and the characterization of monoclonal antibody against CD43, K06

A monoclonal antibody against human CD43 has been developed and designated as K06. Its reactivity in the lymphoid organs was different from that of known anti-CD43 monoclonal antibodies suggesting that this may recognize a novel epitope of human CD43 molecule. The CD43 epitope detected by anti-K06 monoclonal antibody was highly expressed in cortical thymocytes, platelets, and myeloid cells of normal peripheral blood, and its reactivity was comparable to that of known anti-CD43 monoclonal antibodies. However, the density of this epitope was lower in the medullary thymocytes. Biochemical studies indicated that anti-K06 monoclonal antibody could recognize glycosylated moiety of CD43 antigen. The expression profile of anti-K06 monoclonal antibody in several cell lines was somewhat different from that of known anti-CD43 antibodies. In addition, CD43 ligation through the K06 epitope appeared to induce apoptosis in human leukemic cell line, Molt-4. We therefore assume that K06 epitope of human CD43 might have some role in T-cell development.

Two-stage reconstruction of bilateral alveolar cleft using Y-shaped anterior-based tongue flap and iliac bone graft

OBJECTIVE

When an alveolar cleft is too large to close with adjacent mucobuccal flaps or large secondary fistula following a primary bilateral palatoplasty exists, a one-stage procedure for bone grafting becomes challenging. In such a case, we have used the tongue flap to repair the fistula and cleft alveolus followed by bone grafting to the cleft defect performed several months later. The purpose of this article is to report on our experiences with the use of an anteriorly based Y-shaped tongue flap to fit the palatal and labial alveolar defects and on the ultimate result of the bone graft.

PATIENTS

A series of 14 patients were treated with this approach from January 1994 to December 1998. The average age of the patients was 15.8 years (range 5 to 28 years). The mean period of follow-up following the second stage bone graft operation was 45.9 months (range 9 to 68 months). In 9 of the 14 patients, the long-fork type of a Y-shaped tongue flap was used for extended coverage of the labial-side alveolar defects with the palatal fistula; in the remaining patients, the short-forked design was used.

RESULTS

All patients demonstrated a good clinical result after the initial repair of cleft alveolus and palatal fistula. There was no fistula recurrence, although partial necrosis of distal margin in long-forked tongue flap occurred in one patient. Furthermore, the bone graft, which was performed an average of 8 months after the tongue flap repair, was always successful. Occasionally, transferred tongue tissue bulging interfered with the hygienic care of nearby teeth; however, these problems could be solved with proper contour-plasty performed afterward. No donor site complications such as sensory disturbance, change in taste, limitations in tongue movement, normal speech impairments, or tongue disfigurement were encountered.

CONCLUSION

This two-stage reconstruction of a bilateral cleft alveolus using a Y-shaped tongue flap and iliac bone graft was very successful. It may be indicated for a bilateral cleft alveolus patient in which the direct closure of the cleft defect with adjacent tissue or the buccal flap is not easy because of scarred fibrotic mucosa and accompanied residual palatal fistula.

Differential regulation of NO availability from macrophages and endothelial cells by the garlic component S-allyl cysteine

Garlic has been used as a traditional medicine for prevention and treatment of cardiovascular diseases. However, the molecular mechanism of garlic's pharmacological action has not been clearly elucidated. We examined here the effect of garlic extract and its major component, S-allyl cysteine (SAC), on nitric oxide (NO) production by macrophages and endothelial cells. The present study demonstrates that these reagents inhibited NO production through the suppression of iNOS mRNA and protein expression in the murine macrophage cell line RAW264.7, which had been stimulated with LPS and IFNgamma. The garlic extract also inhibited NO production in peritoneal macrophages, rat hepatocytes, and rat aortic smooth muscle cells stimulated with LPS plus cytokines, but it did not inhibit NO production in iNOS-transfected AKN-1 cells or iNOS enzyme activity. These reagents suppressed NF-kappaB activation and murine iNOS promoter activity in LPS and IFNgamma-stimulated RAW264.7 cells. In contrast, these reagents significantly increased cGMP production by eNOS in HUVEC without changes in activity, protein levels, and cellular distribution of eNOS. Finally, garlic extract and SAC both suppressed the production of hydroxyl radical, confirming their antioxidant activity. These data demonstrate that garlic extract and SAC, due to their antioxidant activity, differentially regulate NO production by inhibiting iNOS expression in macrophages while increasing NO in endothelial cells. Thus, this selective regulation may contribute to the anti-inflammatory effect and prevention of atherosclerosis by these reagents.

Structure-activity relationships of apio nucleosides as potential antiviral agents

Several types of novel apio nucleosides were synthesized starting from 1,3-dihydroxyacetone and evaluated for antiviral activity. Among compounds tested, amino substituted apio dideoxynucleosides exhibited anti-HBV activity, while thioapio dideoxynucleosides were found to be active against HIV-1. Apio dideoxydidehydro nucleosides showed moderate to potent anti-HCMV activity, but their bioisosteric thioapio dideoxydidehydro nucleosides did not exhibit any significant antiviral activity.

Syntheses and structure--activity relationships of novel apio and thioapio dideoxydidehydronucleosides as anti-HCMV agents

On the basis of the fact that apio dideoxynucleosides, in which the furanose oxygen and the C2 of the 2,3-dideoxyribose are transposed, exhibited potent anti-HIV activity and 2',3'-dideoxy-2',3'-didehydronucleosides also showed potent anti-HIV activity, we synthesized apio dideoxydidehydronucleosides in which the oxygen atom and the double bond of the 2,3-dideoxy-2,3-didehydroribose are exchanged. The thioapio dideoxydidehydronucleosides were also synthesized since sulfur serves as a bioisostere of oxygen. Apio dideoxydidehydronucleosides 13a--f were synthesized starting from 1,3-dihydroxyacetone, utilizing phenylselenenyl chemistry as a key step. The ratio of the anomeric mixture was variable from 1:1 to 5:1 during the condensation of nucleosidic bases with the phenylselenyl acetate 11 in the presence of a Lewis acid. This is in contrast with other glycosyl donors such as 5-O-(tert-butyldiphenylsilyl)-2-phenylselenenyl-2,3-dideoxyribosyl acetate which shows excellent neighboring group effect (alpha:beta = 1:99). Thioapio dideoxydidehydronucleosides 22a,b were synthesized from the lactone 9 via thiolactone 17 as a key intermediate which was synthesized from dicyclohexylcarbodiimide coupling of the mercapto acid produced from the basic hydrolysis of thioacetate 16. The majority of apio analogues synthesized in this study exhibited moderate to potent anti-HCMV activity, among which the 5-fluorouracil derivative 13c was found to be the most potent against HCMV, while thioapio analogues showed no activity against HCMV. However, all synthesized compounds did not exhibit any significant activities against HIV-1, HSV-1, and HSV-2. The fact that apio dideoxydidehydronucleosides were active against HCMV suggests that the apio dideoxydidehydro sugar moiety can serve as a novel template for the development of new antiviral agents.

Costimulatory effect of Fas in mouse T lymphocytes

To induce proper immune responses, T lymphocytes require two types of stimuli, antigen-specific and costimulatory signals. Among costimulatory molecules, CD28-engagement promotes the survival and proliferation of both naive and memory T cells. In addition, it is now believed that Fas may play a role in T cell activation in the human system. It is, however, controversial whether Fas can act as a costimulatory signal in the murine system. Thus, we investigated fundamental differences in the capacity to induce proliferation of T cells between Fas and CD28 in mice. Fas-mediated T cell proliferation was observed only with a full mitogenic dose of anti-CD3 antibodies, whereas CD28 engagement was able to enhance T cell proliferation in the presence of a suboptimal level of anti-CD3 antibody. Furthermore, Fas-engaged T cells showed faster response in the upregulation of CD25 and CD69 expression than CD28-engaged ones. Here, we report that Fas might play a role in mature T cell activation in the mouse system through a different mechanism from that in CD28 costimulation.

Comparison of two immunization schedules for a Pseudomonas aeruginosa outer membrane proteins vaccine in burn patients

The aim of the present study was to compare two immunization schedules for a Pseudomonas aeruginosa outer membrane proteins (OMPs) vaccine in burn patients. In a double-blind, randomized and placebo-controlled clinical trial, 95 adult patients with burn injuries in 10% or greater of total body surface area were randomly allocated to either placebo or immunization groups. Three doses of the vaccine (0.5 or 1.0 mg) were administered intramuscularly at either 3- or 7-day intervals. The vaccine was well tolerated, and no severe adverse reactions were observed in any of the vaccinees. After three immunizations, 88 patients were available for evaluation of serum antibody titers. Elevation of OMPs-specific antibody titers in the immunization groups was significantly higher as compared with the placebo group, and the highest antibody response was obtained by immunization with 1.0-mg doses at 3-day intervals. Conventional blood culture, tissue culture of wound biopsy specimens and a nested polymerase chain reaction (PCR) assay of blood specimens were performed to determine the protective efficacy. The results of the nested PCR indicated that the overall detection rate of P. aeruginosa in blood was significantly lower among immunized patients than placebo patients (6.1 vs. 40.0%, P<0.001). Based on these results, we concluded that the P. aeruginosa OMPs vaccine is safe and highly immunogenic in burn patients, especially with 1.0-mg doses at 3-day intervals, and may be effective in conferring protection against P. aeruginosa bacteremia in burn patients.

Continuous production of enantiopure 1,2-epoxyhexane by yeast epoxide hydrolase in a two-phase membrane bioreactor

A two-phase membrane bioreactor was developed to continuously produce enantiopure epoxides using the epoxide hydrolase activity of Rhodotorula glutinis. An aqueous/organic cascade, hydrophilic, hollow-fiber membrane bioreactor was used: (1) to carry out large-scale resolution of epoxides, (2) to continuously extract residual enantiopure epoxides from the aqueous phase, and (3) to separate inhibitory formed diol from the yeast cells contained in the aqueous phase. Dodecane was employed to dissolve-feed epoxide as well as to extract residual epoxide. 1,2-Epoxyhexane was used as a model substrate. By use of this membrane bioreactor, enantiopure (S)-1,2-epoxyhexane (>98% enantiomeric excess) was obtained with a volumetric productivity of 3.8 g l(-1) h(-1). The continuous-production system was operated for 12 days and resulted in 38 g enantiopure (S)-1,2-epoxyhexane.

Subacute nicotine exposure in cultured cerebellar cells increased the release and uptake of glutamate

Cerebellar granule and glial cells prepared from 7 day-old rat pups were used to investigate the effects of sub-acute nicotine exposure on the glutamatergic nervous system. These cells were exposed to nicotine in various concentrations for 2 to 10 days in situ. Nicotine-exposure did not result in any changes in cerebellar granule and glial cell viability at concentrations of up to 500 microM. In cerebellar granule cells, the basal extracellular levels of glutamate, aspartate and glycine were enhanced in the nicotine-exposed granule cells. In addition, the responses of N-methyl-D-aspartate (NMDA)-induced glutamate release were enhanced at low NMDA concentrations in the nicotine-exposed granule cells. However, this decreased at higher NMDA concentrations. The glutaminase activity was increased after nicotine exposure. In cerebellar glial cells, glutamate uptake in the nicotine-exposed glial cells were either increased at low nicotine exposure levels or decreased at higher levels. The inhibition of glutamate uptake by L-trans-pyrollidine-2,4-dicarboxylic acid (PDC) was lower in glial cells exposed to 50 microM nicotine. Glutamine synthetase activity was lower in glial cells exposed to 100 or 500 microM of nicotine. These results indicate that the properties of cerebellar granule and glial cells may alter after subacute nicotine exposure. Furthermore, they suggest that nicotine exposure during development may modulate glutamatergic nervous activity.

Resolution of 1,2-epoxyhexane by Rhodotorula glutinis using a two-phase membrane bioreactor

Large-scale resolution of epoxides by the yeast Rhodotorula glutinis was demonstrated in an aqueous/organic two-phase cascade membrane bioreactor. Due to the chemical instability and low solubility of epoxides in aqueous phases, an organic solvent was introduced into the reaction mixture in order to enhance the resolution of epoxide. A cascade hollow-fiber membrane bioreactor was used (1) to minimize the toxicity of organic solvents towards the epoxide hydrolase of R. glutinis, and (2) to remove inhibitory amounts of formed diol from the yeast cell containing aqueous phase. Dodecane was selected as a suitable solvent and 1,2-epoxyhexane as a model substrate. By use of this membrane bioreactor, highly concentrated (0.9 M in dodecane) enantiopure (> 98% ee) (S)-1,2-epoxyhexane (6.5 g, 30% yield) was obtained from the racemic mixture.

Assessment of body composition using dual energy x-ray absorptiometry in patients with liver cirrhosis: comparison with anthropometry

OBJECTIVES

The aim of this study was to evaluate changes of body composition in cirrhotic patients. Dual energy x-ray absorptiometry (DEXA) and anthropometry were used, and the values obtained were compared.

METHODS

Mid-arm fat and muscle areas were calculated by anthropometry in 66 cirrhotic patients and 94 healthy controls. In 37 of the cirrhotic patients and 39 of the controls, fat mass, lean soft tissue mass and bone mineral contents were measured with DEXA.

RESULTS

The number of cirrhotic patients with measured values below the fifth percentile of normal controls was 21 (31.8%) by mid-arm fat area, six (9.1%) by mid-arm muscle area, 15 (40.5%) by fat mass and 0 (0%) by lean soft tissue mass. The fat mass in cirrhotic patients was less than in controls, whereas lean soft tissue mass and bone mineral content were not different. Fat depletion was severe in Child-class C patients and with severe ascites. Mid-arm fat area and fat mass showed close correlation (r = 0.85, p < 0.01), but mid-arm muscle area and lean soft tissue mass showed poor correlation (r = 0.32, p < 0.05).

CONCLUSION

Cirrhotic patients showed lower fat component, with preserved lean soft tissue mass and bone mineral content. In clinical practice, the measurement of mid-arm fat area was useful for the assessment of fat mass.

Laparoscopic resection of gastric diverticulum

Gastric diverticulum is a rare disorder. The laparoscopic approach may be ideal for the resection of gastric diverticulum in some cases. The authors believe this to be the first reported case of gastric diverticulum resected laparoscopically. A 59-year-old woman was admitted with indigestion and epigastric pain. Upper gastrointestinal series showed a single diverticulum (3 x 2 cm) on the posterior wall of the upper part of the stomach. The neck of the diverticulum was relatively narrow. Gastroduodenoscopy revealed that food residues were impacted within the diverticular pouch. Other areas of the stomach and the duodenum were normal. Abdominal ultrasonography showed no other pathologic conditions in the upper part of abdomen. On operation, the lesser sac was entered by division of the greater omentum along the avascular plane of the transverse colonic attachment. The location of the diverticulum was confirmed by intraoperative gastroscopy. Using a 5-cannula techniques, the diverticulum was resected with an endoscopic linear stapler device. Pathologic examination of the resected specimen demonstrated chronic superficial gastritis. Flatus was passed out on the first postoperative day, diet was started from the second day, and the patient was discharged on the fifth day without problems.

Biocatalytic production of chiral epichlorohydrin in organic solvents

Enantioselective hydrolysis of racemic epichlorohydrin was accomplished for the production of enantiopure epichlorohydrin using the whole cells of an isolated Aspergillus niger spps. To overcome the spontaneous chemical degradation of epichlorohydrin that occurs in aqueous buffer, organic solvents were employed in the reaction medium. The enantioselectivity was highly dependent on the solvent structure, water content of the medium, and the initial epichlorohydrin concentration. (S)-epichlorohydrin could be obtained from its racemates (60 mM) with an optical purity of 100% enantiomeric excess (ee) and 20% yield in cyclohexane supplemented with 2.0% (v/v) water.

Near add power of the diffractive multifocal intraocular lens

PURPOSE

To assess near visual acuity and patient satisfaction with the 3M diffractive multifocal intraocular lens (IOL).

SETTING

Asan Medical Center, Ulsan University, Seoul, Korea.

METHODS

Near acuity of 50 eyes implanted with the diffractive multifocal IOL was evaluated postoperatively. Near visual acuity was measured with best distance correction at 33 cm and then at each patient's preferred distance with an extra add of -0.25, +0.25, +0.50, or +0.75 D to the best distance correction. Mean follow-up was 11 months.

RESULTS

All eyes obtained a near vision of J3 or better with the best distance correction and 34 (68.0%) obtained J1 or better. Extra add power increased near vision and was preferred in 44 eyes (88.0%) even though the reading distance was shortened.

CONCLUSION

We recommend adding more than +3.5 D to the 3M multifocal IOL.

Are yeast chitin synthases regulated at the transcriptional or the posttranslational level?

The three chitin synthases of Saccharomyces cerevisiae, Chs1, Chs2, and Chs3, participate in septum and cell wall formation of vegetative cells and in wall morphogenesis of conjugating cells and spores. Because of the differences in the nature and in the time of execution of their functions, the synthases must be specifically and individually regulated. The nature of that regulation has been investigated by measuring changes in the levels of the three synthases and of the messages of the three corresponding genes, CHS1, CHS2, and CAL1/CSD2/DIT101/KTI2 (referred to below as CAL1/CSD2), during the budding and sexual cycles. By transferring cells carrying CHS2 under the control of a GAL1 promoter from galactose-containing medium to glucose-containing medium, transcription of CHS2 was shut off. This resulted in a rapid disappearance of Chs2, whereas the mRNA decayed much more slowly. Furthermore, Chs2 levels experienced pronounced oscillations during the budding cycle and were decreased in the sexual cycle, indicating that this enzyme is largely regulated by a process of synthesis and degradation. For CHS1 and CAL1/CSD2, however, a stop in transcription was followed by a slow decrease in the level of zymogen (Chs1) or an increase in the level of activity (Chs3), despite a rapid drop in message level in both cases. In synchronized cultures, Chs1 levels were constant during the cell cycle. Thus, for Chs1 and Chs3, posttranslational regulation, probably by activation of latent forms, appears to be predominant. Since Chs2, like Chs1, is found in the cell in the zymogenic form, a posttranslational activation step appears to be necessary for this synthase also.

The use of divalent cations and pH for the determination of specific yeast chitin synthetases

Saccharomyces cerevisiae contains three chitin synthetases, Chs1, Chs2, and Chs3, performing different physiological functions but catalyzing the same reaction. It has been found that Ni2+ is a powerful inhibitor of Chs1 and Chs2 activity but has very little effect on the activity of Chs3, especially in the presence of Co2+. These results, together with the previous knowledge that Co2+ stimulates Chs2 and Chs3 but inhibits Chs1 and that the three synthetases differ in their pH optimum, have enabled us to formulate conditions for the specific determination of each synthetase in the presence of the others.

Chitin synthase 3 from yeast has zymogenic properties that depend on both the CAL1 and the CAL3 genes

In previous studies, chitin synthase 3 (Chs3), the enzyme responsible for synthesis of most of the chitin present in the yeast cell, was found to be inactivated by incubation with trypsin, in contrast to other yeast chitin synthases (Chs1 and Chs2), which are stimulated by this treatment (chitin synthase; UDP-N-acetyl-D-glucosamine:chitin 4-beta-N-acetylglucosaminyl-transferase, EC 2.4.1.16). It has now been found that the substrate UDPGlcNAc protects Chs3 against proteolytic inactivation. Treatment of Chs3-containing membranes with detergents drastically reduced the enzymatic activity. Activity could, however, be restored by subsequent incubation with trypsin or other proteases in the presence of UDPGlcNAc. Under such conditions, protease treatment stimulated activity as much as 10-fold. A change in divalent cation specificity after trypsin treatment suggests that the protease directly affects the enzyme molecule. Experiments with mutants in the three genes involved in Chs3 activity--CAL1, CAL2, and CAL3--showed that only CAL1 and CAL3 are required for the protease-elicited (zymogenic) activity. It is concluded that Chs3 is a zymogen and that the CAL2 product functions as its activator. The differences and possible similarities between Chs3 and the other chitin synthases are discussed.

Plasmacytoma presented as a lid mass--a case report

A solitary lid mass was identified as a primary solitary plasmacytoma. A 71 year old male presented with a left upper lid mass. The mass was found to be firmly intermingled with the underlying tarsal plate. A total excision was successfully performed and the lid margin was reconstructed with a good cosmetic result. There were no positive findings in the systemic work-up. The light microscopic findings suggest that the mass is of tarsal plate origin. It is the first case of plasmacytoma of tarsal plate origin presented as a lid mass.