Augmented decision-making for acral lentiginous melanoma detection using deep convolutional neural networks

BACKGROUND

Several studies have achieved high-level performance of melanoma detection using convolutional neural networks (CNNs). However, few have described the extent to which the implementation of CNNs improves the diagnostic performance of the physicians.

OBJECTIVE

This study is aimed at developing a CNN for detecting acral lentiginous melanoma (ALM) and investigating whether its implementation can improve the initial decision for ALM detection made by the physicians.

METHODS

A CNN was trained using 1072 dermoscopic images of acral benign nevi, ALM and intermediate tumours. To investigate whether the implementation of CNN can improve the initial decision for ALM detection, 60 physicians completed a three-stage survey. In Stage I, they were asked for their decisions solely on the basis of dermoscopic images provided to them. In Stage II, they were also provided with clinical information. In Stage III, they were provided with the additional diagnosis and probability predicted by the CNN.

RESULTS

The accuracy of ALM detection in the participants was 74.7% (95% confidence interval [CI], 72.6-76.8%) in Stage I and 79.0% (95% CI, 76.7-81.2%) in Stage II. In Stage III, it was 86.9% (95% CI, 85.3-88.4%), which exceeds the accuracy delivered in Stage I by 12.2%p (95% CI, 10.1-14.3%p) and Stage II by 7.9%p (95% CI, 6.0-9.9%p). Moreover, the concordance between the participants considerably increased (Fleiss-κ of 0.436 [95% CI, 0.437-0.573] in Stage I, 0.506 [95% CI, 0.621-0.749] in Stage II and 0.684 [95% CI, 0.621-0.749] in Stage III).

CONCLUSIONS

Augmented decision-making improved the performance of and concordance between the clinical decisions of a diverse group of experts. This study demonstrates the potential use of CNNs as an adjoining, decision-supporting system for physicians' decisions.

Anabolic payout of terminal implant alters adipogenic gene expression of the longissimus muscle in beef steers

This experiment evaluated the dose and payout pattern of trenbolone acetate (TBA) and estradiol-17β (E) on LM mRNA expression of adenosine monophosphate-activated protein kinase-ɑ (-ɑ), β, G protein-coupled receptor 41(), G protein-coupled receptor 43 (), γ, and stearoyl CoA desaturase () in finishing feedlot steers as indicators of adipogenesis and marbling development. British × Continental steers (n = 168; 14 pens/treatment; initial BW = 362 kg) were used in a randomized complete block design. Treatments included: no implant (NI), Revalor-S (REV-S; 120 mg TBA + 24 mg E), or Revalor-XS (REV-X; delayed release implant: 80 mg TBA + 16 mg E [uncoated], 120 mg TBA + 24 mg E [coated], 200 mg TBA + 40 mg E [total]). Steers were fed 1 time daily for an average of 164 d. The LM biopsies were collected (1 steer/pen) on d -1, 27, 55, and 111 relative to timing of implant. Total RNA was isolated from each sample and real-time quantitative PCR was used to measure quantity of -ɑ, β, , ,it, γ, and mRNA. No implant × day interactions were detected ( ≥ 0.19) in this experiment. Day impacted the mRNA expression of all adipogenic genes ( ≤ 0.02). The main effect of implant tended ( = 0.09) to influence expression of -ɑ, REV-X had an 8.8% increase over NI and an 18.7% increase over REV-S. Implant influenced ( = 0.03) mRNA expression of , expression of for the REV-X treatment was not different ( > 0.10) from NI, and both were greater ( ≤ 0.05) than REV-S (1.13, 1.00, and 0.67 ± 0.224 arbitrary units) for REV-X, NI, and REV-S, respectively. Implant also influenced ( = 0.02) expression of , expression of for REV-X was not different ( > 0.10) from NI, and both were greater ( ≤ 0.05) than REV-S (1.27, 1.07, and 0.72 ± 0.234 arbitrary units) for REV-X, NI, and REV-S, respectively. Implant influenced ( = 0.02) mRNA expression of γ in LM tissue, expression of γ for REV-X was not different ( > 0.10) from NI, and both were greater ( ≤ 0.05) than REV-S (1.09, 1.02, and 0.69 ± 0.195 arbitrary units) for REV-X, NI, and REV-S, respectively. The REV-X steers received the greatest anabolic dose of TBA + E without detriment to marbling scores. The increased mRNA expression of adipogenic genes for REV-X steers suggest that the delayed and gradual release of anabolic stimulants associated with REV-X might have mitigated decreases in marbling generally attributed to multiple combined TBA + E implants.

Effect of rutin from tartary buckwheat sprout on serum glucose-lowering in animal model of type 2 diabetes

This study investigates the anti-diabetic effects of rutin from tartary buckwheat sprout in type 2 diabetes mouse model. The rutin content in tartary buckwheat sprout (TBS) is five times higher than that found in common buckwheat sprout (CBS) as evident from high-performance liquid chromatography analysis. Administration of either rutin or TBS ethanolic extract to diabetes mice decreased the serum glucose level significantly. Rutin down-regulated the expression levels of protein-tyrosine phosphatase 1B; it is negative regulator of insulin pathway, both transcriptionally and translationally in myocyte C2C12 in a dose-dependent manner. In conclusion, rutin can play a critical role in down-regulation of serum glucose level in type 2 diabetes.

Leaf proteome characterization in the context of physiological and morphological changes in response to copper stress in sorghum

Copper (Cu) is an essential micronutrient required for normal growth and development of plants; however, at elevated concentrations in soil, copper is also generally considered to be one of the most toxic metals to plant cells due to its inhibitory effects against many physiological and biochemical processes. In spite of its potential physiological and economical significance, molecular mechanisms under Cu stress has so far been grossly overlooked in sorghum. To explore the molecular alterations that occur in response to copper stress, the present study was performed in ten-day-old Cu-exposed leaves of sorghum seedlings. The growth characteristics were markedly inhibited, and ionic alterations were prominently observed in the leaves when the seedlings were exposed to different concentrations (0, 100, and 150 µM) of CuSO4. Using two-dimensional gels with silver staining, 643 differentially expressed protein spots (≥1.5-fold) were identified as either significantly increased or reduced in abundance. Of these spots, a total of 24 protein spots (≥1.5-fold) from Cu-exposed sorghum leaves were successfully analyzed by MALDI-TOF-TOF mass spectrometry. Of the 24 differentially expressed proteins from Cu-exposed sorghum leaves, 13 proteins were up-regulated, and 11 proteins were down-regulated. The abundance of most identified protein species, which function in carbohydrate metabolism, stress defense and protein translation, was significantly enhanced, while that of another protein species involved in energy metabolism, photosynthesis and growth and development were severely reduced. The resulting differences in protein expression patterns together with related morpho-physiological processes suggested that these results could help to elucidate plant adaptation to Cu stress and provide insights into the molecular mechanisms of Cu responses in C4 plants.

Morpho-Physiological and Proteome Level Responses to Cadmium Stress in Sorghum

Cadmium (Cd) stress may cause serious morphological and physiological abnormalities in addition to altering the proteome in plants. The present study was performed to explore Cd-induced morpho-physiological alterations and their potential associated mechanisms in Sorghum bicolor leaves at the protein level. Ten-day-old sorghum seedlings were exposed to different concentrations (0, 100, and 150 μM) of CdCl2, and different morpho-physiological responses were recorded. The effects of Cd exposure on protein expression patterns in S. bicolor were investigated using two-dimensional gel electrophoresis (2-DE) in samples derived from the leaves of both control and Cd-treated seedlings. The observed morphological changes revealed that the plants treated with Cd displayed dramatically altered shoot lengths, fresh weights and relative water content. In addition, the concentration of Cd was markedly increased by treatment with Cd, and the amount of Cd taken up by the shoots was significantly and directly correlated with the applied concentration of Cd. Using the 2-DE method, a total of 33 differentially expressed protein spots were analyzed using MALDI-TOF/TOF MS. Of these, treatment with Cd resulted in significant increases in 15 proteins and decreases in 18 proteins. Major changes were absorbed in the levels of proteins known to be involved in carbohydrate metabolism, transcriptional regulation, translation and stress responses. Proteomic results revealed that Cd stress had an inhibitory effect on carbon fixation, ATP production and the regulation of protein synthesis. Our study provides insights into the integrated molecular mechanisms involved in responses to Cd and the effects of Cd on the growth and physiological characteristics of sorghum seedlings. We have aimed to provide a reference describing the mechanisms involved in heavy metal damage to plants.

AMPKα, C/EBPβ, CPT1β, GPR43, PPARγ, and SCD Gene Expression in Single- and Co-cultured Bovine Satellite Cells and Intramuscular Preadipocytes Treated with Palmitic, Stearic, Oleic, and Linoleic Acid

We previously demonstrated that bovine subcutaneous preadipocytes promote adipogenic gene expression in muscle satellite cells in a co-culture system. Herein we hypothesize that saturated fatty acids would promote adipogenic/lipogenic gene expression, whereas mono- and polyunsaturated fatty acids would have the opposite effect. Bovine semimembranosus satellite cells (BSC) and intramuscular preadipocytes (IPA) were isolated from crossbred steers and cultured with 10% fetal bovine serum (FBS)/Dulbecco’s Modified Eagle Medium (DMEM) and 1% antibiotics during the 3-d proliferation period. After proliferation, cells were treated for 3 d with 3% horse serum/DMEM (BSC) or 5% FBS/DMEM (IPA) with antibiotics. Media also contained 10 μg/mL insulin and 10 μg/mL pioglitazone. Subsequently, differentiating BSC and IPA were cultured in their respective media with 40 μM palmitic, stearic, oleic, or linoleic acid for 4 d. Finally, BSC and IPA were single- or co-cultured for an additional 2 h. All fatty acid treatments increased (p = 0.001) carnitine palmitoyltransferase-1 beta (CPT1β) gene expression, but the increase in CPT1β gene expression was especially pronounced in IPA incubated with palmitic and stearic acid (6- to 17- fold increases). Oleic and linoleic acid decreased (p = 0.001) stearoyl-CoA desaturase (SCD) gene expression over 80% in both BSC and IPA. Conversely, palmitic and stearic acid increased SCD gene expression three fold in co-cultured in IPA, and stearic acid increased AMPKα gene expression in single- and co-cultured BSC and IPA. Consistent with our hypothesis, saturated fatty acids, especially stearic acid, promoted adipogenic and lipogenic gene expression, whereas unsaturated fatty acids decreased expression of those genes associated with fatty acid metabolism.

Metal oxide coated lithium cobalt fluorophosphate cathode materials for lithium secondary batteries--effect of aging and temperature

Lithium cobalt fluorophosphate (Li2CoPO4F) is a promising 5 V class cathode material for lithium secondary batteries. In this study, surface coating with ZrO2 improved the electrochemical activity of Li2CoPO4F with a maximum discharge capacity of 144 mA h g(-1). The effectiveness of ZrO2 coating was evaluated using aging analysis with a commercial electrolyte, i.e., 1 M LiPF6 in EC:DMC (1:1, v/v). The metal ion dissolution was reduced to 1/8th of that observed in the non-coated Li2CoPO4F. It was found that the thin coating layer had less or no contribution to the additional resistance for the cell, both at an open circuit potential and at a fully charged state; hence, the capacity of the cell was retained over cycling. Elevated temperature aging did not affect the intrinsic property of the coated Li2CoPO4F, as observed from the complete anodic and cathodic peaks from cyclic voltammetry studies after 30 days of storage at 50 degrees C. An increase in impedance was observed for aged cells, which could be due to the thick SEI layer formed during storage. The ZrO2 coating over Li2CoPO4F was crucial for the improved performance of electrode active material at higher operating potentials of up to 5.2 V.

Biological responses of beef steers to steroidal implants and zilpaterol hydrochloride

British × Continental steers (n = 168; 7 pens/treatment; initial BW = 362 kg) were used to evaluate the effect of dose/payout pattern of trenbolone acetate (TBA) and estradiol-17β (E2) and feeding of zilpaterol hydrochloride (ZH) on serum urea-N (SUN), NEFA, IGF-I, and E2 concentrations and LM mRNA expression of the estrogen (ER), androgen (ANR), IGF-I (IGF-IR), β1-adrenergic (β1-AR), and β2-adrenergic (β2-AR) receptors and IGF-I. A randomized complete block design was used with a 3 × 2 factorial arrangement of treatments. Main effects were implant (no implant [NI], Revalor-S [REV-S; 120 mg TBA + 24 mg E2], and Revalor-XS [REV-X; 200 mg TBA + 40 mg E2]) and ZH (0 or 8.3 mg/kg of DM for 20 d with a 3-d withdrawal). Steers were fed for 153 or 174 d. Blood was collected (2 steers/pen) at d -1, 2, 6, 13, 27, 55, 83, 111, and 131 relative to implanting; LM biopsies (1 steer/pen) were collected at d -1, 27, 55, and 111. Blood and LM samples were collected at d -1, 11, and 19 relative to ZH feeding. A greater dose of TBA + E2 in combination with ZH increased ADG and HCW in an additive manner, suggesting a different mechanism of action for ZH and steroidal implants. Implanting decreased (P < 0.05) SUN from d 2 through 131. Feeding ZH decreased (P < 0.05) SUN. Serum NEFA concentrations were not affected by implants (P = 0.44). There was a day × ZH interaction (P = 0.06) for NEFA; ZH steers had increased (P < 0.01) NEFA concentrations at d 11 of ZH feeding. Serum E2 was greater (P < 0.05) for implanted steers by d 27. Serum trenbolone-17β was greater (P < 0.05) for implanted steers by d 2 followed by a typical biphasic release rate, with a secondary peak at d 111 for REV-X (P < 0.05) implanted steers. Implanting did not affect mRNA expression of the ANR or ER, but the IGF-IR and the β1-AR and β2-AR were less (P < 0.05) for REV-S than NI at d 55 and β2-AR mRNA was less (P < 0.05) for REV-S than for REV-X. Expression of the IGF-IR and the β1-AR at d 111 was greater (P< 0.05) for REV-X than for REV-S and NI at d 111, and the β2-AR was less (P< 0.05) for REV-S than for REV-X. Feeding ZH did not affect mRNA expression of the β1-AR and β2-AR. Both implanting and feeding ZH decreased SUN, but a greater dose of TBA + E2 did not result in further decreases. In addition, feeding ZH increased serum NEFA concentrations. Metabolic changes resulting from implanting and feeding ZH may aid in explaining steer performance and carcass responses to these growth promotants.

Comparison of negative pressure wound therapy and secondary intention healing after excision of acral lentiginous melanoma on the foot

BACKGROUND

Melanoma in dark-skinned individuals often develops in an acral lentiginous fashion on the foot and wide excision usually results in a substantial defect. Various repair methods, including free flap, full-thickness skin graft and secondary intention healing (SIH), are used to repair these defects. Recently, use of negative pressure wound treatment (NPWT) has been shown to accelerate wound healing in different types of wound.

OBJECTIVES

To compare the functional and cosmetic results of NPWT and SIH in patients who underwent wide excision of melanomas on the foot.

METHODS

The wound defects of 22 patients after wide excision of melanoma on the foot were treated using SIH (n = 13) or NPWT (n = 9).

RESULTS

There was no significant difference in time to complete wound healing between the two groups. However, evaluation using the Vancouver Burn Scar Assessment Scale at the time of complete healing showed that the mean score of the NPWT group was significantly lower than that of the SIH group. The NPWT group also had significantly better results than the SIH group in terms of total score, vascularity and height of the scars. As for complications, no wound infection was encountered in the NPWT group, whereas eight of the 13 patients in SIH group had wound infections during the course of treatment despite frequent and meticulous aseptic dressing changes.

CONCLUSIONS

These results show that, despite the drawback of rather prolonged healing time, NPWT is an excellent therapeutic option for wounds after wide excision of melanoma on the foot, with acceptable functional and cosmetic outcomes.

A high performance hybrid capacitor with Li2CoPO4F cathode and activated carbon anode

For the first time, we report the possibility of utilizing Li2CoPO4F as a novel cathode material for hybrid capacitor applications. Li2CoPO4F powders were prepared by a conventional two-step solid state method. A hybrid cell was fabricated using Li2CoPO4F as the cathode along with activated carbon (AC) as the anode in 1 M LiPF6 dissolved in 1 : 1 EC/DMC electrolyte and its electrochemical properties were examined by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and constant current charge-discharge (C-D) techniques. The Li2CoPO4F/AC cell is capable of delivering a discharge capacitance of 42 F g(-1) at 150 mA g(-1) current density within 0-3 V region having excellent coulombic efficiency of over 99% even after 1000 cycles. Furthermore, the Li2CoPO4F/AC cell exhibited excellent rate performance with an energy density of ~24 W h kg(-1) at 1100 mA g(-1) current and maintained about 92% of its initial value even after 30,000 C-D cycles. Electrochemical impedance spectroscopy was conducted to corroborate the results that were obtained and described.

Patient perception and knowledge on total joint replacement surgery

OBJECTIVES

To study patients' perceptions and knowledge about total joint replacement surgery. DESIGN; Cross-sectional survey. SETTING; University teaching hospital, Hong Kong.

PATIENTS

Three hundred consecutive patients with the diagnosis of osteoarthritis or inflammatory arthritis attending the out-patient clinic from June 2010 to May 2011.

MAIN OUTCOME MEASURES

Patients' knowledge and how they got the knowledge about total joint replacement surgery, and concerns about the outcome of such operations.

RESULTS

Whilst 94% of the patients knew about total joint replacement surgery, 77% obtained such knowledge from their friends and relatives. The three most common concerns related to this type of operation were whether they might: be wheelchair bound after surgery (64%), need to be taken care of by others for more than 3 months (61%), and have post-surgery complications (54%). Most of them recognised the advantages of the surgery, 82% knew about good pain relief after surgery, and 87% realised that total joint replacement surgery could improve their mobility. Patients did not have a realistic idea regarding the survival of the prosthesis; 41% thought the prosthesis might last for less than 10 years and 34% had no idea about its longevity. CONCLUSION; Patients did recognise the advantages of total joint replacement surgery in treating arthritis. However, they had many concerns about its outcome that warrant clarification. Public education on these aspects is necessary to address concerns, and may be achieved in cooperation with the media.

Administration of estradiol, trenbolone acetate, and trenbolone acetate/estradiol implants alters adipogenic and myogenic gene expression in bovine skeletal muscle

Twenty crossbred yearling steers (421 kg) were used to evaluate the effects of implanting with trenbolone acetate (TBA; 120 mg), estradiol-17β (E(2); 25.7 mg), and a combination (120 mg of TBA and 24 mg of E(2)) on adipogenic and myogenic mRNA concentrations. Animals were blocked by BW and within each block were assigned to 1 of 4 treatments. Animals were housed and fed in individual pens with 5 animals per treatment. All animals were weighed weekly, and muscle biopsy samples were taken from the LM of each steer on d 0 (before implantation), 7, 14, and 28. Total RNA was isolated from each sample and real-time quantitative PCR was used to measure the quantity of C/EBPβ, PPARγ, stearoyl CoA desaturase (SCD), myogenin, and 3 isoforms of bovine myosin heavy chain (MHC) mRNA. Total BW gain from the 28-d period was adjusted to d 0 by use of covariant analysis, and steers in the implant groups tended (P = 0.09) to have increased BW gain compared with nonimplanted control steers. Analysis of the gene expression of MHC showed that neither implant nor day (P > 0.20) had a significant effect on the expression of type I or IIX MHC mRNA There was also no treatment effect (P > 0.20) on MHC-IIA and myogenin, but increasing days on feed increased (P = 0.05) the expression of MHC-IIA mRNA. Relative mRNA abundance of C/EBPβ, PPARγ, and SCD increased (P < 0.05) during days of feed but PPARγ decreased (P < 0.05) with the treatment of combined TBA/E(2) implant. Results of this study indicate that implanting with TBA, E(2), or both increased BW gain and decreased adipogenic gene expression of finishing steers without significantly affecting the concentration of type I, IIA, or IIX MHC mRNA. Increasing days on feed increased both MHC-IIA and adipogenic gene expression in bovine skeletal muscle biopsy samples. We conclude that administration of steroidal implants had no effect on the proportion of the 3 MHC mRNA isoforms but decreased C/EBPβ, PPARγ, and SCD mRNA in bovine skeletal muscle.

Adipogenic gene expression and fatty acid composition in subcutaneous adipose tissue depots of Angus steers between 9 and 16 months of age

We have demonstrated that among carcass adipose tissue depots, brisket subcutaneous adipose tissue contains the greatest concentration of MUFA and lowest concentration of SFA. Therefore, we hypothesized that brisket subcutaneous adipose tissue depots would exhibit greater adipogenic gene expression over time than other major subcutaneous adipose tissue depots. Four Angus steers, each at 9, 12, 14, and 16 mo of age, were harvested and fresh subcutaneous adipose tissue samples were collected from over the brisket, chuck, rib, loin, sirloin, round, flank, and plate. Relative gene expression for C/EBPβ, PPARγ, carnitine palmitoyltransferase-1 beta (CPT-1β), stearoyl-coenzyme A desaturase (SCD), AMP-activated protein kinase alpha (AMPKα), and G-coupled protein receptor 43 (GPR43) was analyzed by quantitative real-time PCR. Expression of C/EBPβ, PPARγ, and CPT-1β was greatest at 12 to 14 mo of age (all P < 0.0001) and declined to very low abundance by 16 mo of age in all depots. Expression of PPARγ and CPT-1β was greater (P < 0.03) in flank, rib, and sirloin subcutaneous adipose tissues than in brisket and round adipose tissues. The expression of the SCD gene did not differ among the 4 age groups (P = 0.95). The palmitoleic:stearic acid ratio (an estimate of SCD activity) was greater (P < 0.001) in the subcutaneous adipose tissues from brisket, plate, and round than in the loin, rib, and sirloin. Conversely, subcutaneous adipose tissue from the loin, rib, and sirloin had greater (P < 0.001) SCD gene expression than the brisket, plate, and round. In general, subcutaneous adipose tissues with the highest concentration of MUFA and least SFA consistently exhibited the least SCD gene expression and adipogenic gene expression. We conclude that MUFA in the brisket and other depots with large SCD indices were deposited before 9 mo of age, during a time when the subcutaneous adipocytes were highly differentiated.

Zilpaterol hydrochloride alters abundance of β-adrenergic receptors in bovine muscle cells but has little effect on de novo fatty acid biosynthesis in bovine subcutaneous adipose tissue explants

We predicted that zilpaterol hydrochloride (ZH), a β-adrenergic receptor (AR) agonist, would depress mRNA and protein abundance of β-AR in bovine satellite cells. We also predicted that ZH would decrease total lipid synthesis in bovine adipose tissue. Bovine satellite cells isolated from the semimembranosus muscle were plated on tissue culture plates coated with reduced growth factor matrigel or collagen. Real-time quantitative PCR was used to measure specific gene expression after 48 h of ZH exposure in proliferating satellite cells and fused myoblasts. There was no effect of ZH dose on [(3)H]thymidine incorporation into DNA in proliferating myoblasts. Zilpaterol hydrochloride at 1 µM decreased (P < 0.05) β1-AR mRNA, and 0.01 and 1 µM ZH decreased (P < 0.05) β2-AR and β3-AR mRNA in myoblasts. The expression of IGF-I mRNA tended to increase (P = 0.07) with 1 µM ZH. There was no effect (P > 0.10) of ZH on the β-AR or IGF-I gene expression in fused myotube cultures at 192 h or on fusion percentage. The β2-AR antagonist ICI-118, 551 at 0.1 µM attenuated (P < 0.05) the effect of 0.1 µM ZH to reduce expression of β1- and β2-AR mRNA. The combination of 0.01 µM ZH and 0.1 µM ICI-118, 551 caused an increase (P < 0.05) in β1-AR gene expression. There was no effect (P > 0.10) of ICI-118, 551 or ZH on β3-AR or IGF-I. Western blot analysis revealed that the protein content of β2-AR in ZH-treated myotube cultures decreased (P < 0.05) relative to control. Total lipid synthesis from acetate was increased by ZH in bovine subcutaneous adipose tissue explants in the absence of theophylline but was decreased by ZH when theophylline was included in the incubation medium. These data indicate that ZH alters mRNA and protein concentrations of β-AR in satellite cell cultures, which in turn could affect responsiveness of cells to prolonged ZH exposure in vivo. Similar to other β-adrenergic agonists, ZH had only modest effects on lipid metabolism in adipose tissue explants.

Oesophagography and oesophagoscopy are not necessary in patients with spontaneous pneumomediastinum

BACKGROUND

Because the condition is rare, the proper assessment of spontaneous pneumomediastinum (SPM) remains controversial. The purpose of this study was to determine whether additional oesophageal investigations beyond chest x ray and chest computed tomography (CT) scan are necessary for the diagnosis of SPM.

METHODS

The medical records of 25 patients diagnosed and treated for SPM from March 1986 to December 2007 were retrospectively reviewed.

RESULTS

There were 22 men and 3 women, with a median age of 19 years (range 15-57 years). All patients received chest x rays, which revealed air shadows within the mediastinum or subcutaneous emphysema in 24 patients. Twenty-two patients underwent chest CT scans, which showed pneumomediastinum in all cases. Oesophagography was performed in 14 patients and oesophagoscopy in three. All oesophagographies and oesophagoscopies were clear. Despite conservative treatment, no patients developed mediastinitis or complications associated with oesophageal injury.

CONCLUSIONS

Chest x ray and CT scan are sufficient to diagnose SPM. Additional diagnostic assessments such as oesophagography and oesophagoscopy are not necessary in patients without evidence of mediastinitis or a history of oesophageal injury.

Treatment of infraorbital dark circles by autologous fat transplantation: a pilot study

BACKGROUND

Infraorbital dark circles are a cosmetic concern for a large number of individuals. However, the exact definition and precise cause has not been elucidated clearly. In our experience infraorbital dark circles due to thin and translucent lower eyelid skin overlying the orbicularis oculi muscle can be treated successfully with autologous fat transplantation.

OBJECTIVES

This study was conducted to clarify the nature of dark circles under the eyes and determine the efficacy of autologous fat transplantation.

PATIENTS AND METHODS

Ten patients with dark circles due to increased vascularity and translucency of the skin were included. They received at least one autologous fat transplantation and follow-up evaluations were conducted at least 3 months after the last treatment.

RESULTS

An average of 1.6 autologous fat transplantations were done in both infraorbital areas. Patients showed an average of 78% improvement (average grading scale: 2.6 out of 4). Most of the patients showed improvement in the infraorbital darkening and contour of the lower eyelids.

CONCLUSIONS

Autologous fat transplantation is an effective method for the treatment of infraorbital dark circles due to thin and translucent lower eyelid skin overlying the orbicularis oculi muscle.

Change of melanocortin receptor expression in rat kidney ischemia-reperfusion injury

OBJECTIVES

alpha-Melanocyte stimulating hormone (alpha-MSH) may ameliorate renal ischemia-reperfusion (I/R) injury. Recent data suggest that melanocortin receptors may be related to the anti-inflammatory and immunomodulating action for alpha-MSH. We designed this experiment to determine the renal distribution of alpha-MSH receptors; melanocortin-1 receptor (MC-1R) and melanocortin-3 receptor (MC-3R).

METHODS

Sprague-Dawley male rats (n = 24) were randomly divided into 2 groups: the sham (n = 2) and the operation groups with warm ischemia (n = 12). Animals in the operation group were subjected to 40 minutes of warm renal ischemia. Western blotting analyses and immunohistochemistry were employed to determine expression of MC-1R and MC-3R.

RESULTS

Expression of MC-1R and MC-3R was decreased on 1 day after reperfusion. Immunohistochemical study confirmed the findings of Western blot analysis.

CONCLUSIONS

The present study demonstrated novel renal expression of MC-1R and MC-3R, especially in the outer medulla, representative of the renal I/R injury. Our current study suggested that the mechanisms of action of alpha-MSH may significantly attenuate the renal I/R injury by specific kidney-targeted effects via MC-Receptors as well as by systemic cytokine effects.

Potential role of G-protein-coupled receptor 30 (GPR30) in estradiol-17beta-stimulated IGF-I mRNA expression in bovine satellite cell cultures

Androgenic and estrogenic steroids enhance muscle growth in animals and humans. Estradiol-17beta (E2) and trenbolone acetate (TBA) (a synthetic testosterone analog) increased IGF-I mRNA expression in bovine muscle satellite cell (BSC) cultures. The goal of this study was to evaluate the mechanisms responsible for this increase by evaluating the effects of ICI 182 780 (an E2 receptor antagonist), flutamide (an androgen receptor inhibitor), G1 (a GPR30 agonist), and BSA-conjugated E2 on E2 and/or TBA-stimulated IGF-I mRNA expression in BSC cultures. Flutamide completely suppressed TBA-stimulated IGF-I mRNA expression in BSC cultures. ICI 182 780 did not suppress E2-stimulated IGF-I mRNA expression and 100 nM ICI 182 780 enhanced (93%, p<0.05) IGF-I mRNA levels in BSC cultures. G1 (100 nM) stimulated IGF-I mRNA expression (100%, p<0.05) but had no effect on proliferation in BSC cultures. E2-BSA, which cannot cross the cell membrane, stimulated IGF-I mRNA expression (approximately 100%, p<0.05) in BSC but even at extremely high concentrations had no effect on proliferation. In summary, our data indicate the E2-stimulation of proliferation and E2-stimulation of IGF-I mRNA expression in BSC cultures occur via different mechanisms. Our previous results showing that ICI 182 780 inhibited BSC proliferation and results of the current study showing lack of response to E2-BSA or G1 suggest that E2-stimulated proliferation in BSC cultures is mediated through classical estrogen receptors. Stimulation by ICI 182 780, G1 and E2-BSA suggests the E2-stimulated IGF-I mRNA expression in BSC cultures is mediated through the GPR30 receptor.

Roles of IGF-I and the estrogen, androgen and IGF-I receptors in estradiol-17beta- and trenbolone acetate-stimulated proliferation of cultured bovine satellite cells

Although numerous studies have shown that both androgenic and estrogenic steroids increase rate and efficiency of muscle growth in steers, there is little consensus as to their mechanism of action. A combined estradiol 17beta (E2)/trenbolone acetate (TBA) implant causes a significant increase in muscle IGF-I mRNA and both E2 and TBA stimulate a significant increase in IGF-I mRNA level in bovine satellite cell (BSC) cultures in media containing 10% fetal bovine serum (FBS). Consequently, increased IGF-I expression may play a role in anabolic-steroid-enhanced muscle growth. However, even though treatment of cultured BSC with E2 or TBA in media containing 1% IGFBP-3-free swine serum (SS) results in increased proliferation there is no effect on IGF-I mRNA expression, suggesting that increased IGF-I expression may not be responsible for anabolic-steroid-enhanced BSC proliferation. To further examine the role of estrogen, androgen and IGF-I receptors and their respective ligands in E2- and TBA-stimulated BSC proliferation, we assessed the effects of specific inhibitors on E2- or TBA-stimulated proliferation of BSC. Both ICI 182 780 (an estrogen receptor blocker) and flutamide (an inhibitor of androgen receptor) suppressed (p<0.05) E2- and TBA-stimulated BSC proliferation, respectively. JB1 (a competitive inhibitor of IGF-I binding to type I IGF receptor) reduced (p<0.05) both E2- and TBA-stimulated proliferation in BSC cultures. Both the Raf-1/MAPK kinase (MEK)1/2/ERK1/2, and the phosphatidylinositol 3-kinase (PI3K)/Akt pathways play significant roles in the actions of IGF-I on proliferation and differentiation of myogenic cells. PD98059, an inhibitor of the MAPK pathway, and wortmannin, an inhibitor of the PI3K pathway, both suppressed (p<0.05) E2- and TBA-stimulated proliferation of cultured BSC. Our data suggest that IGF-I plays a role in E2- and TBA-stimulated proliferation of cultured BSC even in the absence of increased IGF-I expression.

Intramuscular immunoglobulin for recalcitrant suppurative diseases of the skin: a retrospective review of 63 cases

BACKGROUND

Intramuscular human immunoglobulin (HIG) may provide a therapeutic option as an independent or combined treatment for recalcitrant suppurative skin diseases such as hidradenitis suppurativa, folliculitis decalvans, or chronic recurrent furunculosis or folliculitis.

OBJECTIVES

To define the efficacy and safety of intramuscular HIG for chronic and recalcitrant suppurative skin diseases.

METHODS

Patients who had received HIG for hidradenitis suppurativa, folliculitis decalvans, furunculosis or folliculitis at Severance Hospital, Seoul, Korea, between January 2000 and May 2005 were identified from medical/pharmacy records. All records were analysed retrospectively.

RESULTS

Sixty-three patients were identified. After treatment, 37 patients (59%) showed overall improvement and were rated as having an 'excellent response' or 'good response' by the attending physician. No improvement or worsening was seen in only three patients (5%). A period without new lesions (PWNL) was achieved in 46 patients (73%). The number of times HIG was administered to achieve PWNL ranged from 1 to 12 (mean +/- SD 2.15 +/- 1.69). There was no significant difference in the rating score between the independent intramuscular HIG and the combined treatment groups. Pain at the injection site was the major side-effect, which led to the discontinuation of treatment in five patients. No other significant systemic side-effects were observed.

CONCLUSIONS

Our results demonstrate that intramuscular HIG may be used for the treatment of recalcitrant suppurative skin diseases as an independent or combined treatment.

NUP98 Dysregulation in Myeloid Leukemogenesis

Nucleoporin 98 (NUP98) is a component of the nuclear pore complex that facilitates mRNA export from the nucleus. It is mapped to 11p15.5 and is fused to a number of distinct partners, including nine members of the homeobox family as a consequence of leukemia-associated chromosomal translocations. NUP98-HOXA9 is associated with the t(7;11)(p15;p15) translocation in acute myeloid leukemia (AML), myelodysplastic syndrome, and blastic crisis of chronic myeloid leukemia. Expression of NUP98-HOXA9 in murine bone marrow resulted in a myeloproliferative disease progressing to AML by 7-8 months. Transduction of NUP98 fusion genes into human CD34(+) cells confers a proliferative advantage in long-term cytokine-stimulated and stromal cocultures and in NOD-SCID engrafted mice, associated with a five- to eight-fold increase in hematopoietic stem cells. NUP98-HOXA9 expression inhibited erythroid and myeloid differentiation but enhanced serial progenitor replating. NUP98-HOXA9 upregulated a number of homeobox genes of the A and B cluster as well as MEIS1 and Pim-1, and downmodulated globin genes and C/EBPalpha. The HOXA9 component of the NUP98-HOXA9 fusion protein was protected from cullin-4A-mediated ubiquitination and subsequent proteasome-dependent degradation. In NUP98-HOX-transduced CD34(+) cells and cells from AML patients with t(7;11)(p15;p15) NUP98 was no longer associated with the nuclear pore complex but formed intranuclear aggregation bodies. Analysis of NUP98 allelic expression in AML and myelodysplastic syndrome showed loss of heterozygosity observed in 29% of the former and 8% of the latter. This was associated with poor prognosis.

Lipogenesis and stearoyl-CoA desaturase gene expression and enzyme activity in adipose tissue of short- and long-fed Angus and Wagyu steers fed corn- or hay-based diets

Angus and Wagyu steers consuming high-roughage diets exhibit large differences in adipose tissue fatty acid composition, but there are no differences in terminal measures of stearoyl-CoA desaturase (SCD) activity or gene expression. Also, adipose tissue lipids of cattle fed corn-based diets have greater MUFA:SFA ratios than cattle fed hay-based diets. We hypothesized that any changes in SCD gene expression and activity would precede similar changes in adipose tissue lipogenesis between short- and long-fed endpoints. Furthermore, changes in SCD activity and gene expression between production endpoints would differ between corn- and hay-fed steers and between Wagyu and Angus steers. Angus (n = 8) and Wagyu (n = 8) steers were fed a corn-based diet for 8 mo (short-fed; 16 mo of age) or 16 mo (long-fed; 24 mo of age), whereas another group of Angus (n = 8) and Wagyu (n = 8) steers was fed a hay-based diet for 12 mo (short-fed; 20 mo of age) or 20 mo (long-fed; 28 mo of age) to match the end point BW of the corn-fed steers. Acetate incorporation into lipids in vitro was greater (P < 0.01) in corn-fed steers than in hay-fed steers and tended (P = 0.06) to be greater in Wagyu than in Angus s.c. adipose tissue because the rate in Wagyu was twice that of Angus adipose tissue in the corn-fed, short-fed steers. There were diet x end point interactions for lipogenesis in i.m. and s.c. adipose tissues (both P < 0.01) because lipogenesis was 60 to 90% lower in the long-fed cattle than in short-fed cattle fed the corn-based diet. The greatest SCD enzyme activity in Angus s.c. adipose tissue was observed at 24 mo of age (corn-based diet), but activity in Wagyu adipose tissue was greatest at 28 mo of age (hay-based diet; breed x diet x end point interaction, P = 0.08). For short- vs. long-fed endpoints in Angus, s.c. adipose tissue SCD activity was less (hay diet) or the same (corn diet). Conversely, SCD gene expression was greatest in long-fed Wagyu steers fed the hay- or corn-based diets (breed x end point interaction; P < 0.01). Contrary to our hypotheses, SCD activity increased over time, whereas lipogenesis from acetate decreased. However, the developmental pattern of SCD gene expression and activity differed markedly between hay-fed Angus and Wagyu adipose tissues, which may explain the differences in the MUFA:SFA ratios observed in adipose tissues from these cattle.

Effect of dietary energy source on in vitro substrate utilization and insulin sensitivity of muscle and adipose tissues of Angus and Wagyu steers

Angus (n = 8; 210 kg of BW) and 7/8 Wagyu (n = 8; 174 kg of BW) steers were used to evaluate the effects of dietary energy source on muscle and adipose tissue metabolism and insulin sensitivity. Steers were assigned to either a grain-based (corn) or hay-based (hay) diet and fed to similar final BW. At slaughter, LM and s.c. and i.m. adipose tissue samples were collected. Portions of the LM and adipose tissues were placed immediately in liquid N for later measurement of glycolytic intermediates. Fresh LM and s.c. and i.m. adipose tissues were incubated with [U-(14)C]glucose to assess glucose metabolism in vitro. All in vitro measures were in the presence of 0 or 500 ng/mL of insulin. Also, s.c. and i.m. adipose tissues were incubated with [1-(14)C]acetate to quantify lipid synthesis in vitro. Glucose-6-phosphate and fructose-6-phosphate concentrations were 12.6- and 2.4-fold greater in muscle than in s.c. and i.m. adipose tissues, respectively. Diet did not affect acetate incorporation into fatty acids (P = 0.86). Insulin did not increase conversion of glucose to CO(2), lactate, or total lipid in steers fed hay but caused an increase (per cell) of 97 to 110% in glucose conversion to CO(2), 46 to 54% in glucose conversion to lactate, and 65 to 160% in glucose conversion to total lipid content in adipose tissue from steers fed corn. On a per-cell basis, s.c. adipose tissue had 37% greater glucose oxidation than i.m. adipose (P = 0.04) and 290% greater acetate incorporation into fatty acids than i.m. adipose (P = 0.04). Insulin addition to s.c. adipose tissue from corn-fed steers failed to stimulate glucose incorporation into fatty acids, but exposing i.m. adipose tissue from corn-fed steers to insulin resulted in a 165% increase in glucose incorporation into fatty acids. These results suggest that feeding hay limited both glucose supply and tissue capacity to increase glucose utilization in response to insulin without altering acetate conversion to fatty acids. Because s.c. adipose tissue consistently utilized more acetate and oxidized more glucose than did i.m. adipose, these results suggest that hay-based diets may alter i.m. adipose tissue metabolism with less effect on s.c. adipose tissue.

Urinary mononuclear cell and disease activity of systemic lupus erythematosus

Mononuclear cells play a cardinal role in the pathogenesis of systemic lupus erythematosus (SLE). A high urine cytology score has been reported to be associated with lupus nephritis in relapse. The objective of this study was to examine the urinary mononuclear cell population of patients with lupus nephritis, and explore its correlation with lupus disease activity. We studied 12 patients with active lupus nephritis, 17 patients with lupus nephritis in remission, 12 SLE patients with no history of renal disease and 13 healthy subjects. Clinical disease activity was quantified by the SLE Disease Activity Index (SLEDAI). Mononuclear cell species in the urinary sediment were examined by immunocytochemistry. Patients with active lupus nephritis had significantly more mononuclear cells in the urinary sediment. The number of CD3+ cell was significantly elevated in the active lupus nephritis than the others (P < 0.001), while there was no significant difference in the number of CD20+ and CD56+ cell among patient groups. The total urinary mononuclear cell correlated significantly with the overall SLEDAI score (r = 0.58, P < 0.001) as well as the renal score (r = 0.57, P < 0.001). The number of urinary CD3+, but not CD20+ or CD56+, cell significantly correlated with the overall SLEDAI score (r = 0.46, P = 0.003) as well as the renal score (r = 0.40, p = 0.011). In nine patients with renal biopsy, the histological activity index correlated with the total urinary mononuclear cell (r = 0.75, P = 0.02), CD3+ (r = 0.69, P = 0.04) and CD20+ cell (r = 0.69, P = 0.04). We conclude that urinary mononuclear cell was markedly elevated in patients with active lupus, and the urinary mononuclear cell count correlated significantly with the SLEDAI score and histological activity. CD3+ and CD20+ cells are the major component of urinary mononuclear cell in SLE patients and their number correlates with lupus disease activity.

Relation between number of prescribed medication and outcome in peritoneal dialysis patients

BACKGROUND

Many patients with end-stage renal disease need to take a large number of medications. In the present study, we studied the magnitude of problem and explored the relationship between the number of prescribed medications and the clinical outcome of a large cohort of prevalent peritoneal dialysis (PD) patients.

METHODS

We studied the medication list of 266 prevalent PD patients. Dialysis adequacy, residual renal function and nutritional assessment were also performed. The patients were followed for 33.7 +/- 20.7 months.

RESULTS

On average, each patient required 4.7 +/- 1.8 type of medications or 10.0 +/- 4.9 tablets per day. 40 patients (15.0%) needed at least 7 types of medication; 33 patients (12.4%) had to take more than 15 tablets each day. There is a significant but weak correlation between the number of types of medication and the Charlson's comorbidity score (r = 0.252, p < 0.001). Despite the large number of medication prescribed, the blood pressure control, serum cholesterol level, and the use of aspirin after atherosclerotic disease remained suboptimal in many patients. By multivariate analysis, independent factors for patient survival were Charlson's comorbidity score, number of types of medication, duration of dialysis, overall SGA score, and mean arterial blood pressure. Each additional type of medication conferred 20% increase in risk of death (95% CI, 1.6-41.7%, p = 0.032), and the effect is independent on the Charlson's comorbidity score. The actual number of pills taken by a patient did not influence survival in this model.

CONCLUSION

Our results indicate that the number of prescribed medications is related to the clinical outcome of PD patients. The number of prescribed medication may reflect the severity of uremic complications and comorbid diseases not reflected by the Charlson's comorbidity score. Nevertheless, dialysis physicians should carefully balance the clinical need of treating multiple medical conditions with the potential problems of a complicated therapeutic regimen.

Prevention of primary nonfunction after canine liver allotransplantation: the effect of gadolinium chloride

PURPOSE

Effective suppression of Kupffer cell function is believed to contribute to the prevention of preservation/reperfusion injury. In this study, effect of gadolinium, a synthetic Kupffer cell suppressant, on the reperfusion injury was examined using a canine partial liver transplantation model.

METHODS

About a 70% partial liver segment was harvested and reimplanted in a mongrel recipient dog weighing 20 to 25 kg. Gadolinium chloride (10 mg/kg) was infused via the cephalic vein 24 hours before harvest of the partial liver (gadolinium group, n = 5). Serum aspartate aminotransferase (AST), alkaline phosphatase (ALP), lactate dehydrogenase (LDH), and morphologic grading of graft were compared with those of a control group (n = 5). Statistical analysis was done with an independent t-test.

RESULTS

Average total ischemic time was 4 hours and 27 minutes. At 1 hour after reperfusion, there were no significant differences in AST, ALP, or LDH levels, or pathologic scores. At 48 hours after reperfusion, AST (P = .03) and LDH (P = .05) levels were significantly lower in the gadolinium group.

CONCLUSION

Kupffer cell blockade using gadolinium chloride may be effective to reduce ischemia reperfusion injury, but the effect is not evident at an early stage of reperfusion.

Nitrogen and phosphorus removal from swine wastewater by intermittently aerated dynamic-flow system

This study was performed to evaluate the effects of the volume fraction of an anaerobic reactor (VFAR) and SRT on the removal of T-N and T-P in both an intermittently aerated system (IAS) and intermittently aerated dynamic-flow system (IADS), respectively. When the VFAR in the total volume of reactor from both IAS and IADS are 13%, 7%, and 0% at 5 days of SRT, the removal efficiencies of T-P were 80-87%, 62-65% and <30%, respectively. However, it was observed from this study that the removal efficiencies of T-N and T-P were not correlated to VFAR at a predetermined SRT, producing greater than 5000 mg/L of MLVSS. Also, IADS was shown to have the greater buffer capacity and adaptability to resist the shock due to the loading of high concentration of N. Furthermore, IADS achieved over 80% of removal efficiency of N even at much lower C/N ratio of 4.7. Therefore, it seems that IADS has the significant advantages over other biological nutrients removal processes.

Conjugated linoleic acid depresses the delta9 desaturase index and stearoyl coenzyme A desaturase enzyme activity in porcine subcutaneous adipose tissue

Conjugated linoleic acid (CLA) has been shown to have an effect on subcutaneous fatty acid composition and has been reported to decrease stearoyl coenzyme A desaturase (SCD) activity by decreasing mRNA expression and(or) catalytic activity in rodents and rodent cell lines. This investigation was designed to study the effects of CLA, corn oil, or beef tallow supplementation on s.c. adipose tissue fatty acid composition, adiposity, SCD enzyme activity, and the delta9 desaturase index in piglets. Eighteen crossbred barrows 16 to 18 d of age were adapted to diet for 1 wk and then assigned randomly to one of three treatments: 1.5% added CLA, 1.5% added corn oil, or 1.5% added beef tallow. Barrows were penned individually and fed the supplemental oils for 35 d (to 25.6 +/- 0.6 kg BW). Subcutaneous adipose tissue samples were obtained after slaughter. Fatty acid composition of the s.c. adipose tissue differed for each fatty acid measured due to diet with the exception of 18:3. The concentrations of CLA trans-10, cis-12 and cis-9, trans-11 were elevated from nondetectable to 1.62 and 2.52 g/100 g lipid, respectively (P < 0.001 for both isomers). Conjugated linoleic acid decreased the delta9 desaturase index (P < 0.01) and SCD enzyme activity, expressed as nanomoles of palmitate converted to palmitoleate/(7 min x g of tissue) (P = 0.075) and nanomoles of palmitate converted to palmitoleate/(7 min 105 cells) (P= 0.056). Tallow-fed pigs had a greater proportion of large adipocytes (> 700 pL) and the greatest SCD activity. These data provide the first direct evidence that dietary CLA depresses SCD enzyme activity in porcine adipose tissue, which may in part be responsible for the depression of adiposity by CLA observed by others in market weight pigs.

Degradation of 1,3-dichloropropene by a soil bacterial consortium and Rhodococcus sp. AS2C isolated from the consortium

A bacterial consortium capable of degrading the fumigant 1,3-D ((Z)- and (E)- 1,3-dichloropropene) was enriched from an enhanced soil. This mixed culture degraded (Z)- and (E)-1,3-D only in the presence of a suitable biodegradable organic substrate, such as tryptone, tryptophan, or alanine. After 8 months of subculturing at 2- to 3-week intervals, a strain of Rhodococcus sp. (AS2C) that was capable of degrading 1,3-D cometabolically in the presence of a suitable second substrate was isolated. (Z)-3-chloroallyl alcohol (3-CAA) and (Z)-3-chloroacrylic acid (3-CAAC), and (E)-3-CAA and (E)-3-CAAC were the metabolites of (Z)- and (E)- 1,3-D, respectively. (E)- 1,3-D was degraded faster than (Z)- 1,3-D by the strain AS2C and the consortium. AS2C also degraded (E)-3-CAA faster than (Z)-3-CAA. Isomerization of (E)- 1,3-D to (Z)- 1,3-D or the (Z) form to the (E) form did not occur.

Flux enhancement with gas injection in crossflow ultrafiltration of oily wastewater

The gas injection technique was introduced to achieve flux improvement in cross-flow ultrafiltration of oil emulsion. By the nitrogen gas injection, homogeneous liquid phase oil/water emulsion was changed to heterogeneous gas- liquid phase. The injected gas causes positive effect of promoting turbulence, but it also has negative effect of decreasing the effective membrane area due to the partial occupation of membrane pores by bubbles. The efficiency of the gas injection was found out to be dependent on bubble fractions in the mixture: at sufficient bubble fractions the higher flux was observed. but at lower bubble fractions the flux rather decreased compared with that without gas injection. An attempt was made to explain the mechanisms for the dual aspects of gas injection. Turbulence dampening effect was also observed when the dependence of mass transfer coefficient on cross-flow rate was investigated with gas injection.

Formation of DNA triple helix containing N(4)-(6-aminopyridin-2-yl)-2'-deoxycytidine

A cytidinyl derivative, N(4)-(6-aminopyridin-2-yl)- 2'-deoxycytidine ((p)C), could interact with a CG base pair to support the triple-helix (triplex) formation of oligodeoxyribonucleotides. Characteristics of (p)C in the formation of both intramolecular triplex, i.e., a "paper clip type" triplex ((P)CT) and intermolecular triplex, i.e., a "linear type" triplex (LT) was monitored by optical methods and isothermal titration calorimetric measurements. Experimental results revealed that the LT with (p)C*CG internally was independent of the solution pH. Only single substitution of (p)C, situated internally but not terminally, facilitated the (P)CT formation by the UV thermal melting study at the neutral pH. However, the best stabilization of the PCT in acidic conditions occurred when (p)C at the end of the triplex rather than internally. In addition, an LT, but not a (P)CT, containing an alternating (p)CT(p)CT(p)C sequence, could be formed in the conditions of 20 mM MgCl(2) and/or 5 mM spermine. Thus, the presence of several nucleotides of (p)C in proximity along the Hoogsteen strand may lead to structural distortion such that the more flexible LT with multiple substitutions is formed in favor of the more rigid PCT.

Thymoma with pseudosarcomatous stroma

Thymoma with psuedosarcomatous stroma is a recently described, rare variant of thymomas that are characterized by having a biphasic histologic pattern which consists of both an epithelial and a spindle cell stromal component. So far only 11 cases having similar histologic findings have been reported worldwide. At this time we report a case of this rare variant of thymoma which occurred in a 53-year-old Korean man. This previously healthy patient presented with coughing and an anterior mediastinal mass was then detected radiographically. Mediastinal exploration revealed a 9 x 8 x 8 cm-sized well- encapsulated, ovoid, cystic mass. Histological examination showed a biphasic neoplasm composed of anastomosing nests of epithelial cells and somewhat cellular stromal spindle cells that had advanced degenerative changes. Immunohistochemical staining using the antibodies for cytokeratins, EMA, e-cadherin, and p75NGFR showed a strong expression of these markers in the epithelial component but no expression in the spindle stromal cells. The epithelial tumor cells showed no reactivity to CD5 and L26 and a high proportion of the infiltrated lymphocytes were the cortical type that expressed CD99 and terminal deoxynucleotidyl transferase. Ultrastructural examinations revealed tonofilaments in the spindle cells. Follow up has been done for 5 years after the surgical excision and the patient has been free of disease during that period. Similar to previous reports, this patient had a benign clinical course that was unassociated with myasthenia gravis which appears to be a characteristic of this histologic variant of thymoma. However, our case also showed advanced degenerative features and we could demonstrate ultrastructural evidence of epithelial differentiation in the stromal spindle cells that were not mentioned in the previously reported cases. Based on the results of our studies, we suggest this entity is a distinct type of organotypic thymoma that shows cortical differentiation and abundant cellular stroma.

Heparan sulfate proteoglycan expression in the optic chiasm of mouse embryos

Previous studies have demonstrated that heparan sulfate (HS) proteoglycans (PGs) regulate neurite outgrowth through binding to a variety of cell surface molecules, extracellular matrix proteins, and growth factors. The present study investigated the possible involvement of HS-PGs in retinal axon growth by examining its expression in the retinofugal pathway of mouse embryos by using a monoclonal antibody against the HS epitope. Immunoreactive HS was first detected in all regions of the retina at embryonic day (E) 11. The staining was gradually lost in the central regions and restricted to the retinal periphery at later developmental stages (E12--E16). Prominent staining for HS was consistently found in the retinal fiber layer and at the optic disk, indicating a possible supportive role of HS-PGs in axon growth in the retina. At the ventral diencephalon, immunostaining for HS was first detected at E12, before arrival of any retinal axons. The staining matched closely the neurons that are immunopositive for the stage-specific embryonic antigen 1 (SSEA-1). At E13 to E16, when axons are actively exploring their paths across the chiasm, immunoreactivity for HS was particularly intense at the midline. This characteristic expression pattern suggests a role for HS-PGs in defining the path of early axons in the chiasm and in regulating development of axon divergence at the midline. Furthermore, HS immunoreactivity is substantially reduced at regions flanking both sides of the midline, which coincides spatially to the position of actin-rich growth cones from subpial surface to the deep regions of the optic axon layer at the chiasm. Moreover, at the threshold of the optic tract, immunoreactive HS was localized to deep parts of the fiber layer. These findings indicate that changes in age-related fiber order in the optic chiasm and optic tract of mouse embryos are possibly regulated by a spatially restricted expression of HS-PGs.

Cardiac arrhythmias in F-16 pilots during aerial combat maneuvers (ACMS): a descriptive study focused on G-level acceleration

INTRODUCTION

It is well known that acceleration during centrifuge training provokes cardiac arrhythmias. However, there is little research regarding cardiac arrhythmia during actual flight. Therefore, to identify the kinds of cardiac arrhythmias that occur in response to the Aerial Combat Maneuvers (ACM) environment, we analyzed electrocardiograms (ECG) of 35 male pilots.

METHODS

ECGs were recorded from 35 pilots (mean age 31 yr, range 27-39) from 1 h before take-off to 1 h after landing. G-load was simultaneously recorded. To see the patterns of the arrhythmia as Gz force increased, ECG data of each subject were classified into three G levels: a) G-level A was < +3 G; b) G-level B was > or = +3 G but < +6 G lasting longer than 3 s; and c) G-level C was > or = +6 G lasting longer than 3 s.

RESULTS

Mean total flying time of the 35 pilots was 1475 h (range 578-3300). Arrhythmias were observed in 17 of the pilots (49%) during ECG recording. Four pilots (11.4%) experienced arrhythmias before take-off, 16 pilots (45.7%) inflight and 4 pilots (11.4%) after landing. Arrhythmias were recorded in 13 of 35 pilots (37.1%) at G-level A, in 10 of 35 pilots (28.6%) at G-level B and in 1 of 21 pilots (5%) at G-level C. During flight, unifocal premature ventricular contractions (PVC) were experienced by three of the subjects (8.6%); supraventricular premature beats (SVPB) by four subjects (11.4%), and PVCs with bigeminy by one subject (2.9%). Eight subjects (22.9%) experienced combined arrhythmias.

CONCLUSION

There were no clinically significant arrhythmias recorded during ACM in these experienced pilots.