Factors associated with HIV/AIDS-related stigma and discrimination by medical professionals in Korea: A survey of infectious disease specialists in Korea

Objectives

This study sought to identify factors associated with this discrimination by medical professionals in Korea.

Subjects and Methods

This study was a cross-sectional survey. We conducted web-based surveys against infectious disease specialists and infectious disease nurse. We evaluated the frequency of human immunodeficiency virus (HIV)/AIDS-related discrimination by medical professionals by health service type on the 5-point scale. We identified the association between several factors and HIV/AIDS-related stigma and discrimination by medical professionals on the 5-point scale.

Results

A total of 81 experts, 57 infectious disease specialists (approximately 27% of all infectious disease specialists in Korea) and 24 infectious disease nurse practitioners, participated in this study. The frequency of stigma and discrimination increased significantly when invasive treatment included both outpatient and inpatient services (both P < 0.05). Medical professional's preconceptions, fear of infection, and lack of knowledge have an association with HIV/AIDS-related stigma and discrimination by medical professionals.

Conclusion

HIV/AIDS-related stigma and discrimination by medical professionals in Korea might be associated with factors related to the fear of medical professionals.

The accuracies of abdominal computed tomography and the neutrophil-to-lymphocyte ratio used to predict the development of clinically severe acute cholecystitis in elderly patients visiting an emergency department

Background

Mortality in patients with severe acute cholecystitis (AC) remains high, and the prognosis for elderly patients tends to be poor. A comparative analysis of clinical, laboratory, and abdominal computed tomography (CT) parameters was conducted in this study to investigate the effectiveness of each index for predicting clinically severe AC in elderly patients in the emergency department (ED).

Methods

This was a single-center, retrospective study that included 156 patients (≥65 years of age) with AC who were admitted in the ED between January 2012 and December 2014. Parameters including age, gender, initial clinical findings, laboratory findings, and CT findings in the ED were examined for their ability to predict severity.

Results

Forty-five patients were diagnosed with clinically severe AC. The white blood cell count, neutrophil count, neutrophil-to-lymphocyte ratio (NLR), C-reactive protein, erythrocyte sedimentation rate, protein, albumin, and prothrombin time/International Normalized Ratio values were significantly higher in the severe group than in the nonsevere group (P < 0.05). In addition, the CT parameters of increased pericholecystic fat stranding and pericholecystic fluid collection were significantly higher in the severe group than in the nonsevere group (P < 0.001, P < 0.001). Increased pericholecystic fat stranding (odds ratio [OR], 8.17; 95% confidence interval [CI], 2.29-29.22; P = 0.001), pericholecystic fluid collection (OR, 6.55; 95% CI, 1.39-30.92; P = 0.018), and an NLR cutoff value of 9.9 (OR, 4.20; 95% CI, 1.01-17.53; P = 0.049) were independent predictors of severe AC in elderly patients.

Conclusions

The CT parameters of increased pericholecystic fat stranding and pericholecystic fluid collection with an NLR cutoff of 9.9 were useful for predicting the severity of AC in elderly patients in the ED.

The clinical usefulness of initial serum procalcitonin as an aggravation predictor in a hepatobiliary tract infection at emergency department

BACKGROUND AND OBJECTIVES

The ability to predict future clinical deterioration early in patients who present to an emergency care center with a hepatobiliary tract infection is difficult. We studied the clinical usefulness of the initial serum levels of procalcitonin in a hepatobiliary tract infection as an indicator for predicting aggravation in the early stages.

METHODS

Of the patients who presented with the clinical symptoms of a hepatobiliary tract infection, 99 were diagnosed with a hepatobiliary tract infection by imaging studies and subsequently enrolled in the study. Laboratory tests were obtained in the early stage of disease after presentation to an emergency care center. We assessed and compared the serum levels of many early inflammatory markers (white blood cell [WBC] counts, C-reactive protein and procalcitonin) between patients whose symptoms were initially stable upon arrival to an emergency care center but then deteriorated to, those whose symptoms remained consistently stable. Thus, we examined if the above serum markers are useful in predicting the possibility of future symptom aggravation.

RESULTS

Of a total of 99 patients, 27 were assigned to the symptom aggravation group. The serum levels of WBC counts and C-reactive protein in the aggravation group were elevated. However, the median value (interquartile range) of procalcitonin was relatively increased at 2.28 (0.41-7.84 ng/ml), demonstrating a significant difference.

CONCLUSIONS

In conclusion, initial serum levels of procalcitonin might be used as an indicator for aggravation in patients with hepatobiliary tract infection at the emergency department, even though there is hemodynamic stability.

Iliacus abscess with radiculopathy mimicking herniated nucleus pulposus: Additional diagnostic value of magnetic resonance imaging

An iliacus abscess is an extremely rare cause of low back pain. With an iliacus abscess, the classical signs seen with a psoas abscess are frequently absent. Therefore, a timely diagnosis at the initial visit is difficult and inadequate treatment usually results in high mortality. Here, we report the case of 19-year-old man who presented with acute low back pain with radiculopathy and was ultimately diagnosed with an iliacus muscle abscess.

Clinical features of emergency department patients with depression who had attempted to commit suicide by poisoning

BACKGROUND

Many patients present to the emergency department (ED) complaining of intentional poisoning. Of those, some have major depressive disorder (MDD) in their medical history. The aim of this study was to investigate the prevalence of MDD patients who were treated for poisoning in the ED.

MATERIALS AND METHODS

A retrospective review was performed on 268 patients who were treated with poisoning between July 2007 and November 2011. Of these patients, we only included those who were over 18 years of age. Information regarding age, gender, cause, time of ingestion, type of drug, history of attempting suicide, and outcome, among other characteristics, was collected and compared to patients who did not have MDD.

RESULTS

A total of 244 patients were included in this study. Of those, 52 patients (21.3%) had a history of MDD. Compared to non-MDD patients, a majority (34.6% vs. 19.8%) of those in the MDD group had a history of suicide attempts (P = 0.027), and 34 (65.4% in the MDD group vs. 34.4% in the non-MDD group) took more than two types of drugs (P < 0.001). There were no differences in age, sex, time of ingestion or disease severity between MDD and non-MDD patients.

CONCLUSION

In poisoning patients with MDD, physicians in the ED must consider that they have a higher tendency to show suicidal behavior and to have ingested multiple types of drugs.

Effect of tamsulosin on stone expulsion in proximal ureteral calculi: an open-label randomized controlled trial

AIM

Medical expulsive therapy (MET) using alpha-blockers is effective for distal ureteral calculi (UC). We aimed to evaluate the efficacy of tamsulosin for proximal UC expulsion.

MATERIALS AND METHODS

An open-label randomized controlled trial was conducted with 108 patients who agreed to conservative management for single, radiopaque, proximal UC ≤ 6 mm and were randomized into group A (n = 54, conservative managements only) or B (n = 54, 0.2 mg tamsulosin once a day). The primary end-point was stone passage rates (SPR) in the intention-to-treat population in 4 treatment weeks. The secondary end-points were estimated in per-protocol population and were time to stone passage, post-trial Euro-quality-of-life (EuroQOL) score, oral analgesic requirements, and willingness to undergo conservative treatment again.

RESULTS

The two groups were well balanced in terms of baseline patient and stone characteristics. Seventy nine patients (73.2%; 35 of group A and 44 of group B) completed the study protocol. The overall SPR was 60.2% (65/108). Group B had a higher SPR (74.1%; 40/54) than group A (46.3%; 25/54; p = 0.003) and a significantly shorter time to stone passage (mean days, A: 19.6 vs. B: 14.3, p = 0.005). The groups did not differ in post-trial EuroQOL score or oral analgesic requirements, whereas 74.3% (26/35) of group A and 90.9% (40/44) of group B were willing to undergo conservative treatment again (p = 0.048). Univariate logistic regression analysis showed that stone size (OR = 1.447, p = 0.045) and tamsulosin treatment (OR = 3.314, p = 0.004) significantly predicted stone expulsion. On multivariate analysis, only tamsulosin was statistically significant (OR=3.198, p = 0.021).

CONCLUSIONS

Tamsulosin was associated with significantly higher stone expulsion rate and shorter expulsion time in proximal UC ≤ 6 mm compared with conservative managements only. Our results indicate that similar to patients with distal UC, MET using tamsulosin is a reasonable treatment option for patients with proximal UC.

A dual anteroposterior approach to the Bernese periacetabular osteotomy

When the Bernese periacetabular osteotomy is performed through an anterior approach, the ischial and retroacetabular osteotomies and manual fracture of the incompletely osteotomized ischium are conducted with an incomplete view resulting in increased risk and morbidity. We have assessed the dual anteroposterior approach which appears to address this deficiency. We compared the results of the Bernese periacetabular osteotomy performed in 11 patients (13 osteotomies) through a single anterior approach with those in 12 patients (13 osteotomies) in whom the procedure was carried out through a dual anteroposterior approach. The estimated blood loss, the length of anaesthesia, duration of surgery and radiological parameters were measured. The mean operative time and length of anaesthesia were not significantly different in the two groups (p = 0.781 and p = 0.698, respectively). The radiological parameters improved to a similar extent in both groups after the operation but there was significantly less blood loss in the dual osteotomy group (p = 0.034). The dual anteroposterior approach provides a direct view of the retroacetabular and ischial parts of the osteotomy, within a reasonable operating time and with minimal blood loss and gives a satisfactory outcome.

Apparatus and method for achieving reproducible measurements of diauxic lag length and anoxic net maximum specific growth rate

An apparatus for continuous growth of pure bacterial cultures under oxic conditions followed by a switch to anoxic batch conditions was designed. The application of this apparatus gave variability of measured parameters (diauxic lag length, anoxic net maximum specific growth rate) which were significantly lower than the variability of previously reported data. The improvement is attributed to more consistent nitrate reductase levels as a result of achieving steady state under oxic condition prior to switching to anoxic batch conditions.

Treatment of Vascular Skin Lesions with the Variable Pulse 595 nm Pulsed Dye Laser

BACKGROUND

In the dermatology field, variable-pulse 595 nm pulsed dye lasers (PDLs) are now being widely used to treat vascular skin lesions. However, there is little information available on variable-pulse 595 nm PDL treatment of dark-skinned patients.

OBJECTIVE

The objective of this study was to evaluate the outcome of variable-pulse 595 nm PDL treatment on Korean patients.

METHOD

Two hundred thirty-nine patients (Fitzpatrick skin phototypes III to V) with vascular skin lesions, such as nevus flammeus, telangiectasia, or hemangioma, were included in this study. All patients were treated with a variable-pulse 595 nm PDL, and the outcomes were assessed by comparing preoperative and postoperative photographs.

RESULTS

The average number of treatments per patient was 4.29, and 51.9% of patients showed a good (51-75% clearance) to excellent (76-100% clearance) response. For nevus flammeus, 48.0% of the patients achieved good to excellent results. The gender and age of the patients did not influence the clinical response; however, lesions of the head and neck were found to respond more favorably to treatment. For telangiectasia, 78.0% of patients showed good to excellent results, and, again, the gender and age of the patients did not alter the treatment outcome. For hemangioma, the male to female ratio of patients was 1.0:3.1 and 54.1% of the patients achieved a good to excellent response. Superficial hemangioma showed a better clinical response than deep hemangioma, and the lesions of younger patients responded more favorably than those of older patients.

CONCLUSION

The variable-pulse 595 nm PDL was found to be effective for treating several vascular skin lesions in dark-skinned patients. However, there were differences in treatment outcome owing to disease, age, and the location of the lesions.

Soil washing using various nonionic surfactants and their recovery by selective adsorption with activated carbon

The performance of activated carbon in soil washing and subsequent selective adsorption for surfactant recovery from the washed solution was investigated. Sandy loam soil contaminated with phenanthrene at 200 mg kg(-1) was washed with four different nonionic surfactants: Tween 40, Tween 80, Brij 30 and Brij 35. The efficiency of soil washing was highest when using Brij 30 with the highest solubilizing ability for phenanthrene and low adsorption onto soil. In the selective adsorption step, surfactant recovery was quite effective for all surfactants ranging from 85.0 to 89.0% at 1 g L(-1) of activated carbon (Darco 20-40 mesh). Phenanthrene removal from the solution washed with Brij 30 was only 33.9%, even though it was 54.1-56.4% with other surfactants. The selectivity was larger than 7.02 except for Brij 30 (3.60). The overall performance considering both the washing and surfactant recovery step was effective when using Tween 80 and Brij 35. The results suggest that higher solubilizing ability of surfactants is a requirement for soil washing but causes negative effects on phenanthrene removal in the selective adsorption. Therefore, if a surfactant recovery process by selective adsorption is included in soil remediation by washing, the overall performance including the two steps should be considered for properly choosing the surfactant.

A study for the hierarchical artificial neural network model for Giemsa-stained human chromosome classification

A hierarchical multi-layer neural network with an error back-propagation training algorithm has been adopted for the automatic classification of Giemsa-stained human chromosomes. The first step classifies chromosomes data into 7 major groups based on their morphological features such as relative length, relative area, centromeric index, and 80 density profiles. The second step classifies each 7 major groups into 24 subgroups using each group classifier. The classification error decreased by using two steps of classification and the classification error was 5.9%. The result of this study shows that a hierarchical multi-layer neural network can be accepted as an automatic human chromosome classifier.

Cloning and characterization of six highly similar endo-1,3-beta-glucanase genes in hexaploid wheat

Pathogenesis-related (PR) proteins are often used as a marker of plant defense reactions. Some endo-1,3-beta-glucanase (Gns) genes encode proteins that belong to the PR protein family 2 (PR-2). Although the number of homologous family member genes is significantly greater in hexaploid wheat (Triticum aestivum L.) compared to other model plants, earlier studies did not evaluate the possible contribution of their homologs to hybridization signals in Northern blot analysis. In this study, we have examined whether routine transcriptional analyses of a PR gene is of high reliability or not by isolating six highly similar Gns genes (TaGlb2a, TaGlb2b, TaGlb2c, TaGlb2d, TaGlb2e, and TaGlb2f) and characterizing their expression patterns in detail. While TaGlb2b was shown to be a PR-2 gene, transcription of TaGlb2c and TaGlb2d was not induced upon infection with either powdery mildew (Erysiphe graminis) or head blight (Fusarium graminearum) pathogens; their transcripts were most abundant in healthy spikes (lemmas and in particular paleae). Therefore, in some cases, the conventional analyses do not necessarily provide accurate information on expression pattern of a PR gene in hexaploid wheat. This is also the first report of wheat genes that are specifically expressed in lemma/palea tissues of flowering spikelets.

Salvage of the lower extremity free flap using cross-leg venous repair

This retrospective study was designed to evaluate a salvage technique for free flaps suffering venous congestion by using a cross-leg vein repair in patients with venous-impaired lower extremities. Four free flap reconstructions were performed using the latissimus dorsi muscle to reconstruct soft tissue defects in the lower extremity. The recipient artery was confined to the ipsilateral leg and the venous anastomosis was performed with a long saphenous vein from the contralateral side. The legs were immobilised together by means of an external fixator. All patients were males with a mean age of 31 years. The mean time of pedicle division was 8.8 days (7-10). The mean size of the free flap was 186.5 cm(2). All flaps survived after pedicle division without venous congestion. There were no complications such as joint stiffness or donor site morbidity except for a linear scar. The cross-leg venous repair is a refinement of a salvage procedure for compromised free flaps used in the reconstruction of severe soft tissue defects in vascularly compromised lower extremities.

Resurfacing of different types of facial acne scar with short-pulsed, variable-pulsed, and dual-mode Er:YAG laser

BACKGROUND

Laser skin resurfacing has become a popular therapeutic modality for the correction of acne scars, but it is not always effective in all types of acne scars.

OBJECTIVE

To evaluate the clinical effects of resurfacing with the short-pulsed Er:YAG laser, the variable-pulsed Er:YAG laser, and the dual-mode Er:YAG laser for each type of facial acne scars.

METHODS

One hundred fifty-eight patients with facial acne scars were included in this study. Eighty three patients (18 deep boxcar scars, 8 ice-pick scars, 11 rolling scars, and 46 shallow boxcars) were treated with the 350-micros short-pulsed Er:YAG laser at the setting of 12.5 to 15%/cm(2). Thirty-five patients (8 deep boxcar scars, 4 ice-pick scars, 12 rolling scars, and 11 shallow boxcars) were treated with the variable-pulsed Er:YAG laser at the setting of 7.0 to 7.5%/cm(2) and 7-ms pulse duration. Forty patients (8 deep boxcar scars, 4 ice-pick scars, 17 rolling scars, and 11 shallow boxcars) were treated with the dual-mode Er:YAG laser with 350-micro ablation mode at 17.5%/cm(2) and 8-ms coagulation mode at 3.15%/cm(2). Facial photographs were obtained at baseline and at 2- to 4-week intervals postoperatively. Acne scars were classified into four types, and clinical improvements of facial acne scars were evaluated.

RESULTS

Resurfacing with the short-pulsed Er:YAG laser shows good to excellent results for ice-pick and shallow boxcar scars, fair to good for deep boxcar scars, and poor to fair for rolling scars. Resurfacing with the variable-pulsed laser shows good to excellent results for ice-pick and shallow boxcar scars, fair to good for deep boxcar scars, and good for rolling scars. Resurfacing with the dual-mode laser shows good to excellent results for ice-pick, shallow, and rolling scars and produced good results on deep boxcar scars.

CONCLUSION

Shallow boxcar and ice-pick scars can be treated successfully using any types of Er:YAG laser. In cases of rolling and deep boxcar scars, however, Er:YAG laser with a long-pulse duration for a thermal effect is needed for successful treatment.

Inhibition of diazepam on morphine-induced hyperactivity, reverse tolerance and postsynaptic dopamine receptor supersensitivity

The effects of diazepam on the development of reverse tolerance and postsynaptic dopamine receptor supersensitivity induced by morphine were examined in mice. A single administration of morphine induced hyperactivity and the morphine-induced hyperactivity was inhibited dose-dependently by the administration of diazepam (1, 2 and 4 mg x kg(-1), i.p.), an agonist for benzodiazepine receptor linked to the GABA(A) receptor. Daily repeated administration of morphine developed reverse tolerance to the hyperactivity of morphine. The concomitant administration of diazepam inhibited the morphine-induced hyperactivity and the diazepam administration prior to and during the chronic administration of morphine in mice inhibited the development of reverse tolerance to the hyperactivity of morphine (10 mg x kg(-1), s.c.). Postsynaptic dopamine receptor supersensitivity was also developed in reverse tolerant mice that had received the same morphine. The development of postsynaptic dopamine receptor supersensitivity was evidenced by the enhanced ambulatory activity of apomorphine (2 mg x kg(-1), s.c.). Diazepam also inhibited the development of postsynaptic dopamine receptor supersensitivity induced by the chronic administration of morphine. These results suggest that the hyperactivity, reverse tolerance and postsynaptic dopamine receptor supersensitivity induced by morphine may be modulated via the activation of the GABA(A) receptor induced by diazepam.

Design and synthesis of a novel class of histone deacetylase inhibitors

Histone deacetylase inhibitors (HDACs) have emerged as a novel class of antiproliferative agents. Utilizing structure-based design, the synthesis of a series of sulfonamide hydroxamic acids is described. Further optimization of this series by substitution of the terminal aromatic ring yielded HDAC inhibitors with good in vitro and in vivo activities.

Tumor necrosis factor-related apoptosis inducing ligand (TRAIL)-induced apoptosis is dependent on activation of cysteine and serine proteases

We examined the role of caspases and serine protease(s) in cell death induced by tumour necrosis factor-related apoptosis-inducing ligand (TRAIL). After incubation of adenocarcinoma cells with TRAIL, caspase-3, -8 were activated and the cleavage of Bid induced the release of cytochrome c, from the mitochondria to the cytosol. Tetrapeptide inhibitors of caspase-1, -2, -3, and -8 suppressed DNA fragmentation and attenuated the release of cytochrome c, whereas inhibitors of caspase-5 did not. Interestingly, the general serine protease(s) inhibitor 4-(2-aminoethyl)benzylsulfonyl fluoride (AEBSF) resulted in the arrest of apoptosis. However, the AEBSF did not prevent the release of mitochondrial cytochrome c during TRAIL-induced apoptosis. From these results, we postulate that serine protease(s) may be involved in post-mitochondrial apoptotic events, that lead to the activation of the initiator, caspase-9.

Microbial energetics and stoichiometry for biodegradation of aromatic compounds involving oxygenation reactions

Oxygenation reactions significantly alter the energy and electron flows and, consequently, the overall stoichiometry for the microbial utilization of aromatic compounds. Oxygenation reactions do not yield a net release of electrons, but require an input of electrons to reduce oxygen molecules. The biodegradation pathway of phenanthrene as a model compound was analyzed to determine the impact of oxygenation reactions on overall stoichiometry using the half-reaction method. For individual oxygenation reactions, the half-reaction method for analyzing the electron and energy flows must be modified, because the reactions do not release electrons for synthesis or energy generation. Coupling the oxygenation reaction to subsequent reaction steps provides a net electron release for the coupled reactions. Modeling results indicate that oxygenation reactions increase the oxygen requirement and reduce the cell yield, compared to the conventional mineralization represented by hydroxylation reactions in place of oxygenations. The computed yields considering oxygenation reactions conform better to empirical yields reported in the literature than do yields computed by the hydroxylation single-step methods. The coupled-reaction model also is consistent with information about the ways in which micro-organisms that degrade aromatics accumulate intermediates, regulate degradation genes, and organize enzyme clusters.

Cdc5 interacts with the Wee1 kinase in budding yeast

Development of a multicellular organism requires that mitosis and morphogenesis be coordinated. These processes must also be synchronized during the growth of unicellular organisms. In the yeast Saccharomyces cerevisiae, mitosis is dependent on the prior growth of a daughter cell in the form of a bud. Overexpression of wild-type Polo-like kinase Cdc5 or a catalytically inactive form resulted in the formation of multinucleate cells in budding yeast. Immunofluorescence analysis of these multinulceate cells showed that mitosis and bud formation were no longer linked. Others have shown that Swe1 is required for coupling mitosis to bud formation during a perturbed cell cycle. When the normal pathway of bud formation is perturbed, Swe1 functions to delay mitosis through negative regulation of Clb/Cdk. In cells lacking Swe1, multinucleate cells are formed in response to delays in bud formation. Affinity purification, two-hybrid analysis, and mutant characterization results suggested that Cdc5 and Swe1 interact. From these results, we conclude that multinucleate formation in response to Cdc5 overexpression is linked to titration of Swe1 function. These results also suggest that Cdc5 may be a negative regulator of Swe1.

Pre-expanded arterialised venous free flaps for burn contracture of the cervicofacial region

Despite the fact that arterialised venous flaps provide thin good-quality tissue to repair defects of the face and neck, their clinical applications have been limited by an unstable postoperative course and variable flap necrosis. In an effort to resolve these problems, a tissue-expansion technique has been applied to the arterialised venous flap before flap transfer. Three pre-expanded arterialised venous free flaps have been used to treat post-burn scar contracture of the cervicofacial region. The donor site was confined to the forearm in each case. A rectangular expander was usually placed over the fascia of the flexor muscles in the proximal two-thirds of the forearm. The mean expansion period, volume and flap size were 44 days, 420 cm(3)and 147 cm(2), respectively. There were no complications caused by insertion and expansion. The cervicofacial region was successfully reconstructed, after excision of the post-burn contractures, with pre-expanded arterialised venous flaps, with no marginal necrosis or postoperative instability. Large thin arterialised venous flaps are well matched with the recipient defect in the cervicofacial area and the colour and texture match obtained with forearm tissue produced an aesthetically favourable result. Pre-expanded arterialised venous flaps are another new option for free flap reconstruction of the face and neck.

Evaluation of the interaction between biodegradation and sorption of phenanthrene in soil-slurry systems

This work develops and utilizes a non-steady-state model for evaluating the interactions between sorption and biodegradation of hydrophobic organic compounds in soil-slurry systems. The model includes sorption/desorption of a target compound, its utilization by microorganisms as a primary substrate existing in the dissolved phase, and/or the sorbed phase in biomass and soil, oxygen transfer, and oxygen utilization as an electron acceptor. Biodegradation tests with phenanthrene were conducted in liquid and soil-slurry systems. The soil-slurry tests were performed with very different mass transfer rates: fast mass transfer in a flask test at 150 rpm, and slow mass transfer in a roller-bottle test at 2 rpm. The results of liquid tests indicate that biodegradation of the soil-soluble organic fraction did not significantly enhance the biodegradation rate. In the slurry tests, phenanthrene was degraded more rapidly than in liquid tests, but at a similar rate in both slurry systems. Modeling analyses with several hypotheses indicate that a model without biodegradation of compound sorbed to the soil was not able to account for the rapid degradation of phenanthrene, particularly in the roller-bottle slurry test. The model with sorbed-phase biodegradation and the same biokinetic parameters, but unique mass transfer coefficients, simulated the experimental data in both slurry tests most successfully. Reduced mass transfer resistance to bacteria attached to the soil is the most likely phenomenon accounting for rapid sorbed-phase biodegradation.

Inhibition of Baclofen on morphine-induced hyperactivity, reverse tolerance and postsynaptic dopamine receptor supersensitivity

The effects of baclofen on the development of reverse tolerance and postsynaptic dopamine receptor supersensitivity induced by morphine were examined in mice. A single administration of morphine induced hyperactivity and the morphine-induced hyperactivity was inhibited dose dependently by the administration of a GABA(B)receptor agonist, baclofen (1.25, 2.5 and 5 mg kg(-1), i.p.). Daily repeated administration of morphine developed reverse tolerance to the hyperactivity of morphine. The concomitant administration of baclofen inhibited the morphine-induced hyperactivity and the baclofen administration prior to and during the chronic administration of morphine in mice inhibited the development of reverse tolerance to the hyperactivity of morphine (10 mg kg(-1), s.c.). Postsynaptic dopamine receptor supersensitivity was also developed in reverse-tolerant mice that had received the same morphine. The development of postsynaptic dopamine receptor supersensitivity was evidenced by the enhanced ambulatory activity of apomorphine (2 mg kg(-1), s.c.). Baclofen also inhibited the development of postsynaptic dopamine receptor supersensitivity induced by the chronic administration of morphine. These results suggest that the hyperactivity, reverse tolerance and postsynaptic dopamine receptor supersensitivity induced by morphine may be modulated via the activation of GABA(B)receptors induced by baclofen.

Bimodal regulation of Na+-Ca2+ exchanger by -adrenergic signaling pathway in shark ventricular myocytes

In shark heart, the Na(+)--Ca(2+) exchanger serves as a major pathway for both Ca(2+) influx and efflux, as there is only rudimentary sarcoplasmic reticulum in these hearts. The modulation of the exchanger by a beta-adrenergic agonist in whole-cell clamped ventricular myocytes was compared with that of the Na(+)--Ca(2+) exchanger blocker KB-R7943. Application of 5 microM isoproterenol and 10 microM KB-R7943 suppressed both the inward and the outward Na(+)--Ca(2+) exchanger current (I(Na--Ca)). The isoproterenol effect was mimicked by 10 microM forskolin. Isoproterenol and forskolin shifted the reversal potential (E(rev)) of I(Na--Ca) by approximately -23 mV and -30 mV, respectively. An equivalent suppression of outward I(Na--Ca) by KB-R7943 to that by isoproterenol produced a significantly smaller shift in E(rev) of about --4 mV. The ratio of inward to outward exchanger currents was also significantly larger in isoproterenol- than in control- and KB-R7943-treated myocytes. Our data suggest that the larger ratio of inward to outward exchanger currents as well as the larger shift in E(rev) with isoproterenol results from the enhanced efficacy of Ca(2+) efflux via the exchanger. The protein kinase A-mediated bimodal regulation of the exchanger in parallel with phosphorylation of the Ca(2+) channel and enhancement of its current may have evolved to satisfy the evolutionary needs for accelerated contraction and relaxation in hearts of animals with vestigial sarcoplasmic Ca(2+) release stores.

Implication of a small GTPase Rac1 in the activation of c-Jun N-terminal kinase and heat shock factor in response to heat shock

Heat shock induces c-Jun N-terminal kinase (JNK) activation as well as heat shock protein (HSP) expression through activation of the heat shock factor (HSF), but its signal pathway is not clearly understood. Since a small GTPase Rac1 has been suggested to participate in the cellular response to stresses, we examined whether Rac1 is involved in the heat shock response. Here we show that moderate heat shock (39-41 degrees C) induces membrane translocation of Rac1 and membrane ruffling in a Rac1-dependent manner. In addition, Rac1N17, a dominant negative mutant of Rac1, significantly inhibited JNK activation by heat shock. Since Rac1V12 was able to activate JNK, it is suggested that heat shock may activate JNK via Rac1. Similar inhibition by Rac1N17 of HSF activation in response to heat shock was observed. However, inhibitory effects of Rac1N17 on heat shock-induced JNK and HSF activation were reduced as the heat shock temperature increased. Rac1N17 also inhibited HSF activation by l-azetidine-2-carboxylic acid, a proline analog, and heavy metals (CdCl)), suggesting that Rac1 may be linked to HSF activation by denaturation of polypeptides in response to various proteotoxic stresses. However, Rac1N17 did not prevent phosphorylation of HSF1 in response to these proteotoxic stresses. Interestingly, a constitutively active mutant Rac1V12 did not activate the HSF. Therefore, Rac1 activation may be necessary, but not sufficient, for heat shock-inducible HSF activation and HSP expression, or otherwise a signal pathway(s) involving Rac1 may be indirectly involved in the HSF activation. In sum, we suggest that Rac1 may play a critical role(s) in several aspects of the heat shock response.

Optimizing the correction of severe postburn hand deformities by using aggressive contracture releases and fasciocutaneous free-tissue transfers

Severe postburn hand deformities were classified into three major patterns: hyperextension deformity of the metacarpophalangeal joint of the fingers with dorsal contracture of the hand, adduction contracture of the thumb with hyperextension deformity of the interphalangeal joint, and flexion contracture of the palm. Over the past 6 years, 18 cases of severe postburn hand deformities were corrected with extensor tenotomy, joint capsulotomy, and release of volar plate and collateral ligament. The soft-tissue defects were reconstructed with various fasciocutaneous free flaps, including the arterialized venous flap (n = 4), dorsalis pedis flap (n = 3), posterior interosseous flap (n = 3), first web space free flap (n = 3), and radial forearm flap (n = 1). Early active physical therapy was applied. All flaps survived. Functional return of pinch and grip strength was possible in 16 cases. In 11 cases of reconstruction of the dorsum of the hand, the total active range of motion in all joints of the fingers averaged 140 degrees. The mean grip strength was 16.5 kg and key pinch was 3.5 kg. In palm reconstruction, the wider contact area facilitated the grasping of larger objects. In thumb reconstruction, key-pinch increased to 5.5 kg and the angle of the first web space increased to 45 degrees. Jebsen's hand function test was not possible before surgery; postoperatively, it showed more functional recovery in gross motion and in the dominant hand. Aggressive contracture release of the bone,joints, tendons, and soft tissue is required for optimal results in the correction of severe postburn hand deformities. Various fasciocutaneous free flaps used to reconstruct the defect provide early motion, appropriate thinness, and excellent cosmesis of the hand.

Antimalarial, antiproliferative, and antitumor activities of artemisinin-derived, chemically robust, trioxane dimers

Nine C-10 non-acetal derivatives of the natural trioxane artemisinin (1) were prepared as dimers using some novel chemistry. As designed, each dimer was stable chemically. C-10 Olefinic dimers 7 and C-10 saturated dimers 8-13 all showed good to excellent antimalarial and antiproliferative activities in vitro. Dimers 8, 10, and 12 were especially potent and selective at inhibiting growth of some human cancer cell lines in the NCI in vitro 60-cell line assay.

Topoisomerase II inhibition by aporphine alkaloids

The aporphine alkaloids (+)-dicentrine and (+)-bulbocapnine are non-planar molecules lacking features normally associated with DNA binding by intercalation or minor groove binding. Surprisingly, dicentrine showed significant activity as a topoisomerase II (EC 5.99.1.3) inhibitor and also was active in a DNA unwinding assay. The DNA unwinding suggests DNA intercalation, which could explain the inhibition of topoisomerase II. Bulbocapnine, which differs from dicentrine only by the presence of a hydroxyl group at position 11 and the absence of a methoxyl group at position 9, was inactive in all assays. Molecular modeling showed that dicentrine can attain a relatively planar conformation, whereas bulbocapnine cannot, due to steric interaction between the 11-hydroxyl group and an oxygen of the methylenedioxy ring. These observations suggest that dicentrine is an "adaptive" DNA intercalator, which can bind DNA only by adopting a somewhat strained planar conformation. The requirement of a suboptimal conformation to achieve DNA binding appears to make dicentrine a weaker topoisomerase II inhibitor than the very planar oxoaporphine alkaloid liriodenine. These results suggest that it may be possible to modulate DNA binding and biologic activity of drugs by modifications affecting their ability to adopt planar conformations.

Microsurgical reconstruction of partial thumb defects

We have reconstructed thumb defects using microsurgical techniques in 43 patients. The flap survival was 100% and functional improvement with near normal appearance was obtained in the reconstructed thumbs. In order to obtain satisfactory results, donor sites were confined to the great toe and its adjacent structures and adventitia was removed from the vascular pedicle, which was transferred by subcutaneous tunnelling to minimize scar formation in the reconstructed thumb. The width of transferred nail and pulp volume were matched to the defect in the thumb before transfer.

Effects of endothelin-1 on Ca2+ signaling in guinea-pig ventricular myocytes: role of protein kinase C

The effects of ET-1 on contraction, Ca2+ transient and L-type Ca2+ current (ICa.L) were studied in single cells isolated from ventricles of guinea-pig hearts. The aim of our study was to elucidate the mechanism of the positive inotropic effect during endothelin receptor stimulation by focusing on the role of PKC. ET-1 at concentrations of 5 and 10 nM produced a biphasic pattern of inotropism: a first decrease in contraction by 34.4 +/- 2.5% of the control followed by a sustained increase in contraction by 66.6 +/- 8.4% (mean +/- SEM, n = 9). The Ca2+ transient decreased by 13.5 +/- 1.0% during the negative inotropic phase, while it increased by 58.1 +/- 8.4% (n = 10) during the positive inotropic phase. Using the whole-cell voltage-clamp technique with conventional microelectrodes, the application of ET-1 (5 nM) increased the ICa.L by 32.6 +/- 5.1% (n = 10), which was preceded by a short-lived decrease in ICa.L. Incubation of myocytes with pertussis toxin (PTX, at 2 micrograms/ml for > 3 h at 35 degrees C) failed to block the ET-1-induced enhancement of ICa.L. The increases in contraction, Ca2+ transient, and ICa.L by ET-1 were inhibited by pretreatment with 5-N-methyl-N-isobutyl amiloride (MIA; 10 microM), an amiloride analog, and a novel selective Na+/H+ exchange inhibitor HOE694 (10 microM). To determine whether activation of protein kinase C (PKC) is responsible for the enhancement of ICa.L by ET-1, we tested a PKC inhibitor, GF109203X, and found that it does exert an inhibitory effect on the ET-1-induced ICa.L increase. Our study suggests that during ET receptor stimulation an increase in ICa.L due to stimulation of Na+/H+ exchange via PKC activation causes an increase in Ca2+ transients and thereby in the contractile force of the ventricular myocytes.

KR025, a new cytotoxic compound from Myxococcus fulvus

A new bithiazole, KR-025 (1), was isolated from Myxococcus fulvus. Its structure was elucidated by spectroscopic analysis. In addition to 1, the strain produced relatively large quantities of a second, closely related antibiotic, myxothiazol. These compounds demonstrated potent cytotoxicity against human tumor cells.

Classification of the first web space free flap of the foot and its applications in reconstruction of the hand

Owing to its unique anatomic arterial supply and dual nerve innervation, the first web space of the foot can be used to harvest various sizes and shapes of flaps, which the authors have classified into four types according to their usage in hand reconstruction. This in turn depends on the site, shape, and size of the soft-tissue defect in the hand. Web skin flaps (n = 8) were used in prevention of contracture in the first web space and for proximal finger reconstruction. Two-island skin flaps (n = 4) were used to resurface the pulp defect in two adjacent fingers. In severe adduction contracture of the first web space, fill-up web flaps (n = 10) were used to replace the volume defect after a release procedure in the hand. Adjuvant web flaps (n = 9) were used in wrap-around procedures, in dorsalis pedis flap transfer, and in vascularized joint transfer to supplement the main flaps and to restore sensation in the reconstructed area. In the past 10 years up to February of 1998, a total of 31 patients with soft-tissue defects in the hand and fingers were reconstructed using the web space free flap with flap survival rate of 100 percent. The mean static 2-point discrimination was 8.5 (7.2 to 10) mm, and the mean first web angle was 86 degrees. The advantage of the first web space flap from the foot is that it can easily be harvested to match various sizes and shapes of defects in the hand and fingers. In addition, because of the anatomic similarity in contour, thickness, texture, and nerve innervation with the hand, the sensory restoration is excellent with minimal morbidity at the donor site. By classifying the flaps into four types according to various sizes, shapes, and the site from which the flap are harvested, clinical usefulness in various types of hand and finger reconstruction was confirmed.

Role of PKC in the effects of alpha1-adrenergic stimulation on Ca2+ transients, contraction and Ca2+ current in guinea-pig ventricular myocytes

The effects of alpha1-adrenoceptor stimulation on intracellular Ca2+ transients, contractility and L-type Ca2+ current (ICa,L) were studied in single cells isolated from ventricles of guinea-pig hearts. The aim of our study was to elucidate the mechanisms of the positive inotropic effect of alpha1-adrenergic stimulation by focussing on the role of protein kinase C (PKC). Phenylephrine, an alpha1-adrenergic agonist, at concentrations of 50-100 microM elicited a biphasic inotropic response: a transient negative inotropic response (22.9+/-6.0% of control) followed by a sustained positive inotropic response (61.0+/-8.4%, mean+/-SE, n=12). The Ca2+ transient decreased by 10.2+/-3.9% during the negative inotropic phase, while it increased by 67.7+/-10% (n=12) during the positive inotropic phase. These effects were inhibited by prazosin (1 microM), a alpha1-adrenergic antagonist. Phenylephrine increased the ICa,L by 60.8+/-21% (n=5) during the positive inotropic phase. To determine whether activation of PKC is responsible for the increases in Ca2+ transients, contractile amplitude and ICa,L during alpha1-adrenoceptor stimulation, we tested the effects of 4beta-phorbol 12-myristate 13-acetate (PMA), a PKC activator, and of bisindolylmaleimide I (GF109203X) and staurosporine, both of which are PKC inhibitors. PMA mimicked phenylephrine's effects on Ca2+ transients, contractile amplitude and ICa,L. PMA (100 nM) increased the Ca2+ transient, contractile amplitude and ICa,L by 131+/-17%, 137+/-25% (n=8), and 81.1+/-26% (n=5), respectively. Prior exposure to GF109203X (1 microM) or staurosporine (10 nM) prevented the phenylephrine-induced increases in Ca2+ transients, contractile amplitude and ICa,L. Our study suggests that during alpha1-adrenoceptor stimulation increase in ICa,L via PKC causes an increase in Ca2+ transients and thereby in the contractile force of the ventricular myocytes.

Effects of blood flow and venous network on the survival of the arterialized venous flap

The purpose of this study was to evaluate further factors that could explain the survival mechanism in the arterialized venous flap. The authors used 16 canines to investigate the survival rate and pattern of the arterialized venous flap and compared the results with those of the conventional saphenous flap. The number and distribution of draining veins in the arterialized venous flap group were varied to observe their impact on the survival rate and pattern. Gross examination of venous network, blood gas, venogram, blood pressure, and histologic study were also carried out. Although there was no significant difference in final survival rate between conventional flap and arterialized venous flap with two efferent veins (p > 0.01), that of the arterialized venous flap increased significantly as the number of draining veins increased. Blood gas analysis showed that more effective oxygen consumption took place when the number of draining veins increased. By measuring the blood flow and volume at 8 hours after the operation with a laser Doppler flowmeter, it was possible to predict the necrosis of the arterialized venous flap. Attachment to a high pressure arterial blood flow system induced smooth muscle proliferation and neogrowth of elastic fibers in the veins. Furthermore, progressive narrowing of the lumen hastened the development of a collateral circulation, demonstrated on a venogram by the tortuous vessels and neovascularization up to the flap margin. To make it possible to predict and achieve complete survival of the arterialized venous flap, the following criteria must be considered: (a) an arterialized venous flap should be designed to contain most of the venous network in the center, (b) the arterial inflow has to be anastomosed to one afferent vein, (c) two or more efferent veins should drain the arterialized venous flap.

Orally active antimalarial 3-substituted trioxanes: new synthetic methodology and biological evaluation

On the basis of a mechanistic understanding of the mode of action of artemisinin-like antimalarials, a series of structurally simple 3-aryl-1,2,4-trioxanes 5 was designed and was prepared in three to five operations from commercial reactants. The 3-aryl group was attached in each case as a nucleophile. In an electronically complementary fashion, 3-(fluoroalkyl)-trioxanes 6 were prepared via attachment of electrophilic fluoroalkyl esters. Both in vitro and in vivo antimalarial evaluations of these new trioxanes showed 12 beta-methoxy-3-aryltrioxanes 5g, 5j, 5k, and 51 to be highly potent, with crystalline fluorobenzyl ether trioxane 5k especially potent even when administered to rodents orally. As shown by rearrangement of hexamethyl Dewar benzene into hexamethylbenzene, iron-induced degradation of some of these 3-aryltrioxanes 5 involves generation of high-valent iron oxo species that might kill malaria parasites.

DNA polymerase and topoisomerase II inhibitors from Psoralea corylifolia

An ethanol extract of Psoralea corylifolia caused strong DNA polymerase inhibition in a whole cell bioassay specific for inhibitors of DNA replication enzymes. Bioassay-directed purification of the active compounds led to the isolation of the new compound corylifolin (1) and the known compound bakuchiol (2) as DNA polymerase inhibitors. On the basis of the structures of 1 and 2, resveratrol (3) was tested and found to be active as a DNA polymerase inhibitor in this bioassay. Neobavaisoflavone (4) was isolated as a DNA polymerase inhibitor, daidzein (5) as a DNA polymerase and topoisomerase II inhibitor, and bakuchicin (6) as a topoisomerase II inhibitor.

Distal thumb reconstruction with a great toe partial-nail preserving transfer technique

The great toe partial-nail preserving transfer technique is another modification for distal thumb reconstruction in composite defects at or below the interphalangeal joint of the thumb. Noting the size difference of the nail width between the great toe and thumb, the authors dissected only a thumb nail width and skin flap from the great toe, leaving the remainder of the medial skin flap and nail of the great toe at the donor site. A total of 25 cases between 1993 and 1996 were performed using this technique, and the mean follow-up period was more than 12 months. The reconstructed thumb had a better cosmesis with a more natural appearance. At long-term follow-up, the thumb nail width decreased an average of 1.8 mm, but the pulp volume was almost the same as that of the normal contralateral side. The average static 2-point discrimination was less than 9.0 mm. In cases with preserved interphalangeal joint, an average of 48 degrees of range of motion with key-pinch of 80 percent of that of the normal contralateral thumb was achieved. The final appearance of the donor site with partial nail looks like a brachymetatarsia.

Inhibition of topoisomerase II by liriodenine

The cytotoxic oxoaporphine alkaloid liriodenine, isolated from Cananga odorata, was found to be a potent inhibitor of topoisomerase II (EC 5.99.1.3) both in vivo and in vitro. Liriodenine treatment of SV40 (simian virus 40)-infected CV-1 cells caused highly catenated SV40 daughter chromosomes, a signature of topoisomerase II inhibition. Strong catalytic inhibition of topoisomerase II by liriodenine was confirmed by in vitro assays with purified human topoisomerase II and kinetoplast DNA. Liriodenine also caused low-level protein-DNA cross-links to pulse-labeled SV40 chromosomes in vivo, suggesting that it may be a weak topoisomerase II poison. This was supported by the finding that liriodenine caused topoisomerase II-DNA cross-links in an in vitro assay for topoisomerase II poisons. Verapamil did not increase either liriodenine-induced protein-DNA cross-links or catalytic inhibition of topoisomerase II in SV40-infected cells. This indicates that liriodenine is not a substrate for the verapamil-sensitive drug efflux pump in CV-1 cells.

A new repair technique for penile paraffinoma: bilateral scrotal flaps

Although worldwide incidence is not well known, foreign-body injection is often attempted in order to increase the circumference of the penile shaft. Paraffin, Vaseline, and other materials are injected into the penile skin by the patient himself or by untrained persons who practice medicine fraudulently. Complications usually follow, such as penile deformity, skin necrosis, limited erectile function, and the inability to have intercourse. Definitive treatment of these patients includes the complete removal of skin and subcutaneous tissue infiltrated by the foreign material. Sometimes, complete removal of the foreign material may not be possible and may leave permanent foreign-body granuloma on the corpus cavernosum and/or corpus spongiosum. The remaining foreign material does not permit skin-graft coverage, which is a simple and effective method of resurfacing. In such cases, we tried a new technique comprised of bilateral scrotal flaps to provide for reliable and stable coverage. The scrotal skin, which has high elasticity, seems to be a good material for penile coverage, despite its hairy nature. In our experience, exclusively with Korean males, the scrotal hair has a low density and does not seem to cause serious problems, but patients with hirsute scrotal may be contraindicated. Since 1993, 17 patients with penile paraffinoma have been treated using the bilateral scrotal flap method. All 34 flaps survived completely and the reconstructed penis had immediate postoperative tactile sensibility. The results were successful and without any major complications.

Inhibition of topoisomerase II by ICRF-193, the meso isomer of 2,3-bis(2,6-dioxopiperazin-4-yl)butane. Critical dependence on 2,3-butanediyl linker absolute configuration

The bis(2,6-dioxopiperazine)s are a structurally and mechanistically unique class of topoisomerase II inhibitors that do not bind DNA and that do not stabilize topoisomerase II-DNA strand passing intermediates ("cleavable complexes"). The most effective topoisomerase II inhibitor in the bis(2,6-dioxopiperazine) series is ICRF-193 (meso or S*, R* isomer), with a meso 2,3-butanediyl linker connecting the dioxopiperazine rings. The two enantiomeric diastereomers, (R,R) and (S,S), of ICRF-193 possessing the two optically active 2,3-butanediyl linkers have been prepared from their respective optically pure 2,4-diaminobutanes via 2,3-diaminobutane-N,N,N',N'-tetraacetic acid, esterification, and imide formation. Both in vivo and in vitro assays for catalytic inhibition of topoisomerase II were employed to show that the (S,S)- and (R,R)-isomers are almost inactive as topoisomerase II inhibitors. The data indicate that the meso stereochemistry of the alkanediyl linker is crucial for activity and provides additional evidence that the cytotoxicity of the bis(2,6-dioxopiperazine)s is due to their ability to inhibit topoisomerase II.

Resurfacing relatively large skin defects of the hand using arterialized venous flaps

Skin flaps nourished by arterial blood entering through the venous network were applied in 12 cases of relatively large skin defects of the hand. The flaps showed remarkable oedema and multiple bullae on their surface from the second to the 14th postoperative day, but partial necrosis of the flap only developed in three cases. The free arterialized venous flap is a useful procedure for resurfacing relatively large skin defects of the hand.