[A Case of Biliary Obstruction Caused by Liver Cyst].

Most cystic lesions of the liver are found incidentally in imaging studies because they are not symptomatic, and generally do not require treatment. Rarely, however, symptomatic hepatic cysts may develop complications and require treatment. Here, we describe a case of a 77-year-old woman who developed biliary obstruction with abdominal pain due to compression of the bile duct by a simple hepatic cyst. We confirmed the diagnosis based on symptoms and imaging studies. The patient'ssymptoms improved after simple cyst ablation by sclerotherapy.

On computing stress in polymer systems involving multi-body potentials from molecular dynamics simulation.

Hardy stress definition has been restricted to pair potentials and embedded-atom method potentials due to the basic assumptions in the derivation of a symmetric microscopic stress tensor. Force decomposition required in the Hardy stress expression becomes obscure for multi-body potentials. In this work, we demonstrate the invariance of the Hardy stress expression for a polymer system modeled with multi-body interatomic potentials including up to four atoms interaction, by applying central force decomposition of the atomic force. The balance of momentum has been demonstrated to be valid theoretically and tested under various numerical simulation conditions. The validity of momentum conservation justifies the extension of Hardy stress expression to multi-body potential systems. Computed Hardy stress has been observed to converge to the virial stress of the system with increasing spatial averaging volume. This work provides a feasible and reliable linkage between the atomistic and continuum scales for multi-body potential systems.

[Analysis of acquired resistance genes in Stenotrophomonas maltophilia].

BACKGROUND: Stenotrophomonas maltophilia is a gram-negative bacillus and a nosocomial pathogen in immunocompromised patients. Trimethoprim/sulfamethoxazole (TMP/SMX) is the drug of choice for treating S. maltophilia infection; however, resistance to TMP/SMX is increasing. In this study, we investigated the relationship between the incidence of TMP/SMX resistance and the presence of sul genes and mobile elements. METHODS: A total of 120 S. maltophilia isolates were collected from 3 university hospitals between April 2007 and April 2009. Antimicrobial susceptibilities were determined using the disk diffusion method. PCR and DNA sequencing were conducted for the detection of sul1, sul2, class 1 integron, and ISCR2 element. Repetitive extragenic palindromic sequence-based PCR (REP-PCR) was carried out to evaluate the genetic relatedness. RESULTS: The TMP/SMX-resistant (R) isolates harbored a significantly higher proportion of sul1 gene and class 1 integron than TMP/SMX-susceptible (S) isolates (P<0.001). Seventeen of 28 isolates with sul1 also had a class 1 integron, but none of the isolates without sul1 had a class 1 integron. The identified gene cassettes within class 1 integrons include aacA4, aadA1, aac6'-II, and qac. None of the 120 isolates carried sul2, glmM, or ISCR2 element. REP-PCR did not show any genetic relatedness among the isolates. CONCLUSIONS: In Korea, the resistance of S. maltophilia isolates to TMP/SMX is due to sul1 within a class 1 integron rather than to sul2. The class 1 integron also harbors multiple antibiotic resistance genes in addition to sul1, and therefore it could mediate multidrug resistance in S. maltophilia.

Normal Physiologic and Benign Foci with F-18 FDG Avidity on PET/CT in Patients with Breast Cancer.

PURPOSE: The aim of this study was to evaluate the physiologic and benign F-18 fluorodeoxyglucose (FDG) avid foci in patients with breast cancer. METHODS: On 309 F-18 FDG PET/CT scans of 241 women with breast cancer, the hypermetabolic lesions compared with the surrounding normal region were evaluated retrospectively. Available reports of other relevant radiological imaging, medical records, and follow-up PET/CT were reviewed for explanations of the abnormal uptake. RESULTS: Among the 70 physiologic foci, muscular uptake of the lower neck following the surgical and/or radiation therapy of ipsilateral breast (29%), hypermetabolic ovaries (16%) and uterine (10%) uptake during the ovulatory and menstrual phases during the normal menstrual cycle were identified, and also hypermetabolic brown fat in cold-induced thermogenesis (7%), non-specific bowel uptake (35%) were observed. Among the 147 benign lesions, sequelae of the chest wall and breasts following surgical and/or radiation therapy, were often observed (27%). Hypermetabolic thyroid glands were noted as adenomas and chronic thyroiditis (18%). Reactive hyperplasia of cervical or mediastinal lymph nodes (32%), degenerative osteoarthritis and healed fractures (15%), hypermetabolic benign lung lesions (6%) were observed. CONCLUSION: Altered physiologic and benign F-18 FDG uptake in the lower cervical muscle and chest wall following ipsilateral breast surgery or radiotherapy were common, and also normal physiologic uptake in ovary and uterus, brown fat, thyroid were considered as predominant findings in women patients with breast cancer. Knowledge of these findings might aid in the interpretation of FDG PET/CT in patients with breast cancer.

Chromosome 8 pentasomy with partial tandem duplication of 11q23 in a case of de novo acute myeloid leukemia.

Polysomy 8 is a rare abnormality, one that has been reported as associated with secondary evolution, monocytic differentiation, or poor prognosis in myeloid neoplasm. In contrast to tetrasomy 8, which is most commonly observed, pentasomy 8 is a minority component of polysomy 8. To date, only three cases of pentasomy 8 accompanied with 11q23 rearrangement have been reported. Reported here is a novel case of pentasomy 8 with partial tandem duplication of 11q23 in de novo acute myeloid leukemia. The findings contribute to understanding of the relation between the two abnormalities, which have their own individual leukemogenic potencies.

Characteristics of aac(6')-Ib-cr gene in extended-spectrum beta-lactamase-producing Escherichia coli and Klebsiella pneumoniae isolated from Chungnam area.

BACKGROUND: Concomitant quinolone resistance in extended-spectrum beta-lactamase (ESBL)-producing Enterobacteriaceae is a crucial problem in the clinical management of infections. In foreign countries, the fluoroquinolone acetylating aminoglycoside-(6)-N-acetyltransferase (aac[6']-Ib-cr) gene, a novel plasmid-mediated quinolone resistance determinant has been reported to occur in conjunction with qnr. We aim to investigate the prevalence and characteristics of concomitant aac(6')-Ib-cr and qnr expression in ESBL-producing Escherichia coli and Klebsiella pneumoniae in Korea. METHODS: Between December 2007 and April 2008, we collected 60 and 69 clonally unrelated non-repetitive clinical isolates of ESBL-producing E. coli and K. pneumoniae, respectively. We studied the expressions of 11 types of ESBL-encoding genes, 4 types of 16s rRNA methylase genes; rmtA, rmtB, rmtC and armA, 3 types of qnr genes; qnrA, qnrB, qnrS and aac(6')-Ib. The presence of aac(6')-Ib-cr variants was detected by sequencing. The involvement of integrons was studied using multiplex PCR and sequencing of gene-cassette arrays. Conjugation experiments were performed to confirm plasmid-mediated resistance and the relationships among co-harbored genes. RESULTS: We observed a high prevalence of the cr variant (61.1%) of aac(6')-Ib, and the prevalence of this variant in qnr and aac(6')-Ib-co-harboring isolates (67.4%) was higher than in qnr-negative isolates (51.7%). The high prevalence of the cr variant was significantly related to the high minimum inhibitory concentrations (MICs) of ciprofloxacin, tobramycin, and amikacin and indicated the statistically significant roles of qnrB, qnrS, rmtA, and rmtB in quinolone and aminoglycoside resistance. CONCLUSIONS: The aac(6')-Ib-cr variants were widespread and showed significant relation to the high-level quinolone and aminoglycoside resistance in ESBL-producing E. coli and K. pneumoniae.

Evaluation of two automated instruments for pre-transfusion testing: AutoVue Innova and Techno TwinStation.

BACKGROUND: Despite the advances in total laboratory automation, a considerable amount of work in blood banks is still done using outdated manual methods. Some automated pre-transfusion testing instruments have recently been developed. Of these, we evaluated and compared the AutoVue Innova (Ortho, USA) and the Techno TwinStation (DiaMed AG, Switzerland). METHODS: Forward and reverse ABO/Rh typing and unexpected antibody screening and identification tests were performed on 4,628 samples using the manual method and the two automated instruments. Two different anticoagulants (EDTA and citrate) were compared in ABO/Rh typing and unexpected antibody screening tests. Titrating studies were conducted on the following 7 dilutions using 5 samples of irregular antibodies with anti-E, anti-E & -c, anti-D, and anti-Le(a) with anti-Fy(a): 1:2, 1:4, 1:8, 1:16, 1:32, 1:64, and 1:128. The test throughput per hour, the time required to perform 1 and 100 tests, and a simulation test for total events occurring in 1 day were also measured. RESULTS: No erroneous results were reported between the two instruments and the manual method. Discrepancies observed in 10 cases (0.4%) of ABO/Rh typing were of higher intensity with AutoVue Innova than with the manual method. AutoVue Innova exhibited the highest sensitivity in the titrating study and throughput performance compared with the manual method and the Techno TwinStation. Especially in the throughput and time required to complete 100 antibody screening tests, AutoVue Innova had a 3.3- and 3.5-fold higher performance, respectively, than Techno TwinStation. CONCLUSIONS: Because both of the two fully automated instruments (AutoVue Innova and Techno TwinStation) had high levels of accuracy and performance, it is expected that use of fully automated instruments will reduce human labor, turnaround time, and operator error in the blood bank.

[Dissemination of IMP-1 and OXA type beta-lactamase in carbapenem-resistant Acinetobacter baumannii].

BACKGROUND: Acinetobacter baumannii is an aerobic, gram-negative, glucose-nonfermenting bacterium, which has emerged as a serious opportunistic pathogen. In recent years, the increasing instance of carbapenem-resistant A. baumannii producing metallo-beta-lactamases (MBLs) or OXAtype beta-lactamases is causing a serious clinical problem. In this study, we investigated the prevalence of Ambler class A, B, and D beta-lactamases and their extended-spectrum derivatives in carbapenem-resistant A. baumannii isolates. METHODS: A total of 31 consecutive, non-duplicate, carbapenem-resistant A. baumannii were isolated from three university hospitals in the Chungcheong province of Korea. The modified Hodge and inhibitor-potentiated disk diffusion tests were conducted for the screening of carbapenemase and MBL production, respectively. PCR and DNA sequencing were performed for the detection of beta-lactamase genes. We also employed the enterobacterial repetitive intergenic consensus (ERIC)-PCR method for the epidemiologic study. RESULTS: Twenty-three of 31 isolates harbored bla(OXA-2)(51.6%), bla(OXA-23)(22.6%), bla(IMP-1)(48.4%),and bla(VIM-2)(3.2%). All of the OXA-2-producing strains also evidenced MBLs. The strains that harbored bla(OXA-23)were isolated only in hospital C, and only in a limited fashion. The ERIC-PCR pattern of the five OXA-23 strains indicated that the isolates were closely related in terms of clonality. The six strains producing IMP-1 isolated from hospital A were confirmed to be identical strains. CONCLUSIONS: A. baumannii strains harboring IMP-1 or OXA-type beta-lactamases are currently widely distributed throughout the Chungcheong province of Korea. The most notable finding in this study was that a bla(OXA-2)-producing A. baumannii harboring MBL, which has not been previously reported, can also lead to outbreaks.

Antinociception of heterotopic electro-acupuncture mediated by the dorsolateral funiculus.

We investigated the inhibitory pathways that mediate the antinociceptive effects of heterotopic electro-acupuncture (EA) on formalin injection-induced pain in rats. EA (2 ms, 10 Hz, 3 mA) was delivered to heterotopic acupoints HT(7) and PC(7) for 30 min; this was followed immediately by subcutaneous injection of formalin into the left hind paw of rats. Naltrexone (10 mg/kg, i.p.), an opioid receptor antagonist, was administered to evaluate the involvement of endogenous opioids. The dorsolateral funiculus (DLF), which is a descending pathway that inhibits pain, was transected at the ipsilateral T10-11 level of the thoracic spinal cord. EA inhibited behavioral responses to formalin injection-induced pain and prevented the pain-induced increase in cFos expression in the lumbar spinal cord. Pretreatment with naltrexone did not inhibit the antinociceptive effects of EA on formalin injection-induced pain. Transection of the DLF ipsilateral to the acupuncture site eliminated the antinociceptive effects of EA. These results suggest that the antinociceptive effects of heterotopic EA are mediated by the DLF and not by endogenous opioids.