Efficacy of preoxygenation with end-tidal oxygen when using different oxygen concentrations in patients undergoing general surgery: a single-center retrospective observational study

BACKGROUND

Preoxygenation is a simple but very important procedure for preventing arterial desaturation. A higher fraction of inspired oxygen (FiO2) increases atelectasis and 80% oxygen results in significantly less atelectasis than 100% oxygen. We investigated whether there was a difference in the duration of adequate preoxygenation when using 100% and 80% oxygen. The proportion of patients for whom >3 min was required to achieve adequate preoxygenation was also investigated.

METHODS

The VitalDB database of patients underwent general surgery between February 1, 2021 and November 12, 2021 was reviewed. The time between the start of preoxygenation and the point where a 10% difference between FiO2 and end-tidal oxygen (EtO2) was defined as the preoxygenation time. The patients were classified into 100% and 80% groups according to the oxygen concentration. Propensity score matching (PSM) was performed to control for potential confounding factors.

RESULTS

Only 330 of the 1,377 patients had sufficient data for analysis: 179 in the 80% group and 151 in the 100% group. After PSM, 143 patients in each group were analyzed. The median preoxygenation time was 143 s [interquartile range (IQR): 120.5-181.5 s] and 144 s (IQR: 109.75-186.25 s) in the 80% and 100% groups, respectively [P=0.605; median difference =-1 s; 95% confidence interval (CI): -13 to 10]. Of the patients, 27% required >3 min for adequate preoxygenation.

CONCLUSIONS

No difference in preoxygenation time was found between the 80% and 100% groups. For some patients, breathing for 3 min is not sufficient for adequate preoxygenation. EtO2 monitoring aids evaluation of whether preoxygenation was adequate.

Successful extracorporeal membrane oxygenation in a patient with central airway obstruction due to an endotracheal mass

Extracorporeal membrane oxygenation (ECMO) assists blood circulation and gas exchange via a heart–lung machine. ECMO is used mainly in intensive care units as bridging therapy until heart and respiratory failure can be addressed or until transplantation can be performed. ECMO is sometimes used during surgery under general anaesthesia, depending on the patient’s underlying diseases and the nature of the operation. If the oxygen supply and carbon dioxide removal capacity are limited, venovenous (VV)-ECMO can be helpful. Here, we describe the use of VV-ECMO for surgical resection of an endotracheal mass through rigid bronchoscopy in a patient who developed decompensating dyspnoea due to central airway obstruction (CAO).

Intraoperative use of noninvasive ventilation during spinal anaesthesia in patients with severe chronic obstructive pulmonary disease undergoing orthopaedic surgery: A case report

Compared with invasive mechanical ventilation, noninvasive ventilation (NIV) improves patient comfort and neurocognitive function; and reduces the likelihood of nosocomial infections and the need for sedation. NIV can also be used perioperatively to prevent postoperative pulmonary complications. This current report describes a case of a 64-year-old female patient with chronic obstructive pulmonary disease and chronic respiratory failure that underwent spinal anaesthesia during surgery. She was sedated with propofol. She brought her home ventilator equipment to the operating room and it was used in biphasic-positive airway pressure mode for immediate treatment of respiratory depression.

Impact of Bilateral Subcostal Plus Lateral Transversus Abdominis Plane Block on Quality of Recovery After Laparoscopic Cholecystectomy: A Randomized Placebo-Controlled Trial

BACKGROUND

Previous research has not evaluated the potential effect of transversus abdominis plane (TAP) block on quality of recovery following laparoscopic cholecystectomy. Therefore, we investigated whether addition of the bilateral subcostal and lateral TAP (bilateral dual TAP [BD-TAP]) blocks to multimodal analgesia would improve the quality of recovery as assessed with the Quality of Recovery-40 (QoR-40).

METHODS

Patients age 18 to 60 years who were scheduled to undergo elective laparoscopic cholecystectomy were randomized to the BD-TAP or control group. The BD-TAP group received the BD-TAP block with multimodal analgesia under general anesthesia, using 0.25% ropivacaine, and the control group was treated with the same method, except that they received the sham block using 0.9% normal saline. Both groups had the same multimodal analgesia regimen, consisting of intravenous dexamethasone, propacetamol, ibuprofen, and oxycodone. The primary outcome was the QoR-40 score at 24 hours after surgery. Data were analyzed using the independent t test, Mann-Whitney U test, χ2 test, and Fisher exact test.

RESULTS

Thirty-eight patients in each group were recruited. The mean QoR-40 score decreased by 13.6 (95% confidence interval [CI], 8.3-18.8) in the BD-TAP group and 15.6 (95% CI, 6.7-24.5) in the control group. The postoperative QoR-40 score at 24 hours after surgery did not differ between the 2 groups (BD-TAP group, median [interquartile range], 170.5 [152-178]; control group, 161 [148-175]; median difference, 3 [95% CI, -5 to 13]; P = .427). There were no differences between the 2 groups in the pain dimension of the QoR-40: 30.5 (95% CI, 27-33) in the BD-TAP group and 31 (95% CI, 26-32) in the control group; median difference was 0 (95% CI, -2 to 2); P = .77.

CONCLUSIONS

Our results indicate that the BD-TAP block does not improve the quality of recovery or analgesic outcomes following laparoscopic cholecystectomy. Our results do not support the routine use of the BD-TAP block for this surgery.

Ultrasound-guided pulsed radiofrequency treatment for distal suprascapular neuropathy: A case report

RATIONALE

Suprascapular neuropathy is a rare cause of shoulder pain, and patients usually presents with posterosuperior shoulder pain and weakness on forward flexion and external rotation. Suprascapular neuropathy associated with rotator cuff pathology has received attention as an emerging cause of this condition. Suprascapular nerve (SSN) block can be used in these patients, and pulsed radio frequency (PRF) can be applied to achieve a long-term effect. Several studies have reported on PRF treatment of the SSN for shoulder pain, but most applied treatment to the nerve trunk under the transverse scapular ligament. This report describes a patient with suprascapular neuropathy treated with selective application of PRF to the distal SSN under ultrasound guidance.

PATIENT CONCERNS

A 68-year-old woman suffered from right posterior shoulder pain after traumatic full thickness rotator cuff tear. Her pain was not diminished despite of 2 surgeries.

DIAGNOSES

She was diagnosed with entrapment of the distal SSN in the spino-glenoid (SGN) notch and suprascapular neuropathy.

INTERVENTIONS

She underwent surgery to decompress the entrapped SSN in the SGN. After that, we applied PRF on the distal SSN under ultrasound guidance for persistent pain. This treatment was repeated 3 times.

OUTCOMES

PRF treatment resulted in a slight reduction in the visual analogue scale (VAS) pain score from 7-8/10 to 5-6/10 at the 2 weeks follow-up, and to 2-3/10 at the 1 month follow-up. The reduction in pain was maintained at the 1 year follow-up.

LESSONS

PRF treatment of the SSN is typically approached from the main branch in the suprascapular notch. We selectively applied PRF to the distal SSN close to the SGN. This technique was safe and effective.

Liver transplantation in Jehovah's Witnesses: two cases report

Liver transplantation is especially challenging in patients who are Jehovah's Witnesses because their religious beliefs prohibit the receipt of blood products. We present two cases of living donor liver transplantation performed in adult Jehovah's Witnesses in South Korea without the use of blood products. In the first case, preoperative erythropoiesisstimulation therapy increased hemoglobin levels from 8.1 to 13.1 g/dl after 9 weeks. In the second case, hemoglobin levels increased from 7.4 to 10.8 g/dl after 6 months of erythropoiesis-stimulation therapy. With the combination of acute normovolemic hemodilution, intraoperative cell salvage, and use of transfusion alternatives, liver transplantation was successfully performed without transfusion of blood products.

Development of the Geop-Pain questionnaire for multidisciplinary assessment of pain sensitivity

Background

To assess the multidisciplinary aspects of pain, various self-rating questionnaires have been developed, but there have not been sufficient relevant studies on this topic in South Korea. The aim of this study was to develop a new pain sensitivity-related questionnaire in the Korean language that would be simple and would well reflect Koreans' senses.

Methods

A new pain assessment questionnaire was developed through a pre-survey on "geop", which is the Korean word expressing fear, anxiety, or catastrophizing. We named the new assessment questionnaire the Geop-Pain Questionnaire (GPQ). The GPQ was composed of 15 items divided into three categories and rated on a 5-point scale. As a preliminary study, internal consistency and test-retest reliability analyses were conducted. Subsequently, 109 individuals completed the GPQ along with three pain-related questionnaires translated into Korean (Pain Sensitivity Questionnaire [PSQ], Pain Anxiety Symptoms Scale [PASS], and Pain Catastrophizing Scale [PCS]), and the correlations were analyzed.

Results

All items in the GPQ showed appropriate internal consistency, and the test-retest reliability analysis showed no statistically significant differences. The correlations between the GPQ and the existing questionnaires revealed that the GPQ scores had mid-positive correlations with the PSQ scores and strong positive correlations with the PASS and PCS scores.

Conclusions

This study attempted to develop a questionnaire assessing pain sensitivity multidimensionally using the Korean word geop for the first time. The self-rating GPQ showed high correlations with the existing questionnaires and demonstrated potential to be utilized as a pain prediction index in clinical practice.

A novel family VIII carboxylesterase hydrolysing third- and fourth-generation cephalosporins

A metagenomic library was constructed from a soil sample of spindle tree-rhizosphere. From this library, one clone with esterase activity was selected. The sequence analysis revealed an open reading frame (EstSTR1) encoded protein of 390 amino acids. EstSTR1 is a family VIII carboxylesterase and retains the S-X-X-K motif conserved in both family VIII carboxylesterases and class C β-lactamases. The estSTR1 gene was overexpressed in E. coli and the recombinant protein was purified by purified by metal chelating affinity chromatography and size-exclusion chromatography. EstSTR1 hydrolysed p-nitrophenyl esters, exhibited the highest activity toward p-nitrophenyl butyrate. Furthermore, EstSTR1 could hydrolyse third- and fourth-generation cephalosporins (cefotaxime and cefepime) as well as first-generation cephalosporin (cephalothin). Site-directed mutagenesis studies revealed that a catalytic residue, Ser71, of EstSTR1 plays an essential role in hydrolysing both antibiotics and p-nitrophenyl esters. We demonstrate that a metagenome-derived carboxylesterase displays β-lactam-hydrolysing activities toward third- and fourth-generation cephalosporins.

Screening and characterization of a novel cellulase gene from the gut microflora of Hermetia illucens using metagenomic library

A metagenomic fosmid library was constructed using genomic DNA isolated from the gut microflora of Hermetia illucens, a black soldier fly. A cellulase-positive clone, with the CS10 gene, was identified by extensive Congo-red overlay screenings for cellulase activity from the fosmid library of 92,000 clones. The CS10 gene was composed of a 996 bp DNA sequence encoding the mature protein of 331 amino acids. The deduced amino acids of CS10 showed 72% sequence identity with the glycosyl hydrolase family 5 gene of Dysgonomonas mossii, displaying no significant sequence homology to already known cellulases. The purified CS10 protein presented a single band of cellulase activity with a molecular mass of approximately 40 kDa on the SDS-PAGE gel and zymogram. The purified CS10 protein exhibited optimal activity at 50°C and pH 7.0, and the thermostability and pH stability of CS10 were preserved at the ranges of 20~50°C and pH 4.0~10.0. CS10 exhibited little loss of cellulase activity against various chemical reagents such as 10% polar organic solvents, 1% non-ionic detergents, and 0.5 M denaturing agents. Moreover, the substrate specificity and the product patterns by thinlayer chromatography suggested that CS10 is an endo-β-1,4-glucanase. From these biochemical properties of CS10, it is expected that the enzyme has the potential for application in industrial processes.

Lupus enteritis: clinical characteristics and predictive factors for recurrence

OBJECTIVES

To compare the clinical characteristics of lupus enteritis (LE) and non-enteric lupus (non-LE) patients and identify predictors of LE recurrence.

METHODS

We retrospectively reviewed the medical records of 62 systemic lupus erythematosus (SLE) patients in a tertiary hospital who experienced enteric symptoms and underwent abdominal computed tomography scanning between January 1997 and December 2013. We compared the clinical characteristics between LE and non-LE patients and between recurrent LE and non-recurrent LE cases.

RESULTS

Out of 62 SLE patients with enteric symptoms, 46 cases (74%) were compatible with LE based on computed tomography findings. The C4 level was decreased in the LE group compared with the non-LE group (9.0 ± 5.6 vs. 12.3 ± 6.2, p = 0.032). Recurrence of LE was observed in 14 patients (28%). Initial involvement at the colon (79% vs. 41%, p = 0.026) and bladder with/without the ureter was more common in the recurrent group (57% vs. 25%, p = 0.048). By multivariate analysis, the hazard ratios of variables associated with recurrence were 4.689 for colon involvement (95% confidence interval: 1.245-17.659, p = 0.0220] and 5.468 for cystitis with/without ureteritis (95% confidence interval: 1.629-18.360, p = 0.006).

CONCLUSION

Colon and urinary tract involvement in LE patients may be associated with the recurrence of LE.

Oct4 is a critical regulator of stemness in head and neck squamous carcinoma cells

Cancer stem cells (CSCs) have been suggested as responsible for the initiation and progression of cancers. Octamer-binding transcription factor 4 (Oct4) is an important regulator of embryonic stem cell fate. Here, we investigated whether Oct4 regulates stemness of head and neck squamous carcinoma (HNSC) CSCs. Our study showed that ectopic expression of Oct4 promotes tumor growth through cyclin E activation, increases chemoresistance through ABCC6 expression and enhances tumor invasion through slug expression. Also, Oct4 dedifferentiates differentiated HNSC cells to CSC-like cells. Furthermore, Oct4(high) HNSC CSCs have more stem cell-like traits compared with Oct4(low) cells, such as self-renewal, stem cell markers' expression, chemoresistance, invasion capacity and xenograft tumorigeneity in vitro and in vivo. In addition, knockdown of Oct4 led to markedly lower HNSC CSC stemness. Finally, there was a significant correlation between Oct4 expression and survival of 119 HNSC patients. Collectively, these data suggest that Oct4 may be a critical regulator of HNSC CSCs and its targeting may be potentially valuable in the treatment of HNSC CSCs.

An outbreak of lymphomas in a layer chicken flock previously infected with fowlpox virus containing integrated reticuloendotheliosis virus

Visceral lymphomas occurred in a 236-day-old layer flock previously diagnosed with reticuloendotheliosis virus (REV)-integrated fowlpox virus (FPV) infection at the age of 77 days. Common pathologic lesions were multiple neoplastic nodules of homogeneous lymphocytes in the livers and spleens of all submitted chickens. All neoplastic tissues were positive for the REV envelope (env) gene by PCR. In a retrospective molecular study of FPV-infected 77-day-old chickens from the same flock, we identified nearly full-length REV provirus integrated into the genome of FPV as well as the REV env gene in trachea samples, whereas only the REV LTR region was present in the FPV strain used to vaccinate this flock. The 622-bp REV env gene nucleotide sequence derived from the trachea and neoplastic tissues was identical. Commercial ELISA of serum samples revealed that all chickens aged between 17 and 263 days in this flock were positive for REV but not for avian leukosis virus. Taken together, the evidence suggests that the visceral lymphomas were caused by a REV-integrated FPV field strain. FPV infections of commercial chickens should be followed up by careful monitoring for manifestations of REV infection, including lymphomas and immune depression, considering the ease with which the REV provirus appears to be able to integrate into the FPV genome.

Molecular survey of enteric viruses in commercial chicken farms in Korea with a history of enteritis

Several enteric viruses have increasingly received attention as potential causative agents of runting-stunting syndrome (RSS) in chickens. A molecular survey was performed to determine the presence of a broad range of enteric viruses, namely chicken astrovirus (CAstV), avian nephritis virus (ANV), chicken parvovirus (ChPV), infectious bronchitis virus (IBV), avian rotavirus (AvRV), avian reovirus (ARV), and fowl adenovirus (FAdV), in intestinal samples derived from 34 commercial chicken flocks that experienced enteritis outbreaks between 2010 and 2012. Using techniques such as PCR and reverse-transcription PCR, enteric viruses were identified in a total of 85.3% of investigated commercial chicken flocks in Korea. Furthermore, diverse combinations of 2 or more enteric viruses were simultaneously identified in 51.7% of chicken farms positive for enteric viruses. The rank order of positivity for enteric viruses was as follows: ANV (44.1%), CAstV (38.2%), ChPV (26.5%), IBV (20.6%), ARV (8.8%), AvRV (5.9%), and FAdV (2.9%). Additionally, other pathogens such as Escherichia coli, Salmonella spp., Eimeria spp., and FAdV were detected in 79% of chicken flocks positive for enteric viruses using PCR, bacterial isolation, and microscopic examination. The results of our study indicate the presence of several enteric viruses with various combinations in commercial chicken farms that experienced enteritis outbreaks. Experimental studies are required to further understand the roles of enteric viruses in RSS in commercial chickens.

Altered expression of E-cadherin and β-catenin in malignant transformation of sinonasal inverted papillomas

BACKGROUND

E-cadherin and β-catenin are molecules that mediate cell-cell adhesion in normal epithelium. Aberrant expression of these adhesion molecules results in the loss of intercellular adhesion, with possible cell transformation and tumour progression. We determined the role of E-cadherin and β-catenin in the pathogenesis of sinonasal inverted papilloma (IP) and its malignant transformation.

METHODS

We determined the expression of E-cadherin and β-catenin by immunohistochemistry in paraffin-embedded tissue of 21 subjects with nasal polyps, 56 with IPs, 7 IPs with dysplasia and 18 IPs with squamous cell carcinoma (SCC). The clinicopathological variables of the IPs with SCC correlated with the degree of expression of E-cadherin and β-catenin.

RESULTS

The degree of expression of E-cadherin and β-catenin in the cell membrane was significantly lower in IPs with SCC than in nasal polyps and IPs. The degree of expression of β-catenin was significantly lower in IPs with SCC with a malignant proportion > 50% compared to a malignant proportion ≤ 50%. However, there was no significant association between the degree of expression of E-cadherin and β-catenin and clinicopathological variables, such as age, gender, T stage, tumour differentiation, or SCC type (metachronous vs. synchronous). In addition, there was no significant relationship between recurrence or survival rate in IPs with SCC and the degree of expression of E-cadherin or β-catenin in the cell membrane or nuclear β-catenin.

CONCLUSION

Decreased expression of E-cadherin and β-catenin in the cell membrane may be associated with carcinogenesis of IPs and help predict malignant transformation in sinonasal IPs.

Identification and characterization of inhibitors of Haemophilus influenzae acetohydroxyacid synthase

Acetohydroxyacid synthase (AHAS), a potential target for antimicrobial agents, catalyzes the first common step in the biosynthesis of branched-chain amino acids. The gene coding for the AHAS catalytic subunit from Haemophilus influenzae (Hi) was cloned, overexpressed in Escherichia coli, and purified. To identify new inhibitory scaffolds, we used a high-throughput screen to test 221 small diverse chemical compounds against Hi-AHAS. Compounds were selected for their ability to inhibit AHAS in vitro. The screen identified 3 compounds, each representing a structural class, as Hi-AHAS inhibitors with an IC(50) in the low micromolar range (4.4-14.6 μM). The chemical scaffolds of the three compounds were oxa-1-thia-4-aza-cyclopenta[b]naphthalene (KHG25229), phenyl-2,3-dihydro-isothiazole (KHG25386), and phenyl-pyrrolidine-3-carboxylic acid phenylamide (KHG25056). Further, molecular docking of the two most potent chemicals, KHG25229 and KHG25386, in Hi-AHAS yielded binding energies of -10.41 and -9.21 kcal/mol, respectively. The binding modes were consistent with inhibition mechanisms, as both chemicals oriented outside the active site. As the need for novel antibiotic classes to combat drug resistant bacteria increases, screening compounds that act against Hi-AHAS may assist in the identification of potential new anti-Hi drugs.

Molecular cloning and biochemical characterization of alpha- and beta-tubulin from potato plants (Solanum tuberosum L.)

Few studies have investigated microtubules from plants that host pathogenic fungi. Considerable efforts are underway to find an antimitotic agent against plant pathogens like Phytophthora infestans. However, screening the effects of antifungal agents on plant tubulin in vivo or using purified native microtubule in vitro is a time consuming process. A recombinant, correctly folded, microtubule-like structure forming tubulin could accelerate research in this area. In this study, we cloned full length cDNAs isolated from potato leaves using reverse-transcribed polymerase chain reaction (RT-PCR). Solanum tuberosum (Stub) alpha-tubulin and beta-tubulin were predicted to encode 449 and 451 amino acid long proteins with molecular masses of 57 kDa and 60 kDa, respectively. Average yields of alpha- and beta-tubulin were 2.0-3.5 mg l(-1) and 1.3-3.0 mg l(-1) of culture, respectively. The amino acids, His6, Glu198, and Phe170 involved in benomyl sensitivity were conserved in Stub tubulin. The dimerization of tubulin monomers was confirmed by western blot analysis. When combined under appropriate conditions, these recombinant alpha- and beta-tubulins were capable of polymerizing into microtubules. Accessibility of cysteine residues of tubulin revealed that important ligand binding sites were folded correctly. This recombinant tubulin could serve as a control of phytotoxicity of selected antimitotic fungicide compounds during in vitro screening experiments.

Chitinophaga niabensis sp. nov. and Chitinophaga niastensis sp. nov., isolated from soil

Two yellow-coloured bacterial strains, designated JS13-10(T) and JS16-4(T), were isolated from soil from Jeju Island, Republic of Korea. On the basis of 16S rRNA gene sequence analysis, the strains were found to be affiliated with members of the genus Chitinophaga. Phenotypically, the novel strains were identified as being different from each other and from recognized species of the genus Chitinophaga. DNA-DNA hybridization tests between the two novel strains and closely related Chitinophaga reference strains produced DNA relatedness values that were significantly lower (<36 %) than those generally accepted as the highest threshold for the phylogenetic definition of a species. On the basis of their distinct taxonomic characteristics, these strains represent two novel species of the genus Chitinophaga, for which the names Chitinophaga niabensis sp. nov. (type strain JS13-10(T)=KACC 12952(T)=JCM 15440(T)) and Chitinophaga niastensis sp. nov. (type strain JS16-4(T)=KACC 12954(T)=JCM 15441(T)) are proposed.

Aquitalea denitrificans sp. nov., isolated from a Korean wetland

A novel bacterium, designated strain 5YN1-3(T), was isolated from wetland peat collected from Yongneup, Korea. The bacterium was facultatively anaerobic, Gram-negative, yellow-coloured, rod-shaped, mesophilic and motile with one polar flagellum. The strain grew optimally at 30 degrees C, at pH 6.0-9.0 and with 0-1 % NaCl (w/v). 16S rRNA gene sequence analysis showed the highest similarity to the sequence from Aquitalea magnusonii TRO-001DR8(T), with 98.7 % sequence similarity. However, strain 5YN1-3(T) showed DNA-DNA relatedness of 43 % (40 % in a reciprocal experiment) with A. magnusonii LMG 23054(T). The strain contained summed feature 3 (iso-C(15 : 0) 2-OH and/or C(16 : 1)omega7c) and C(16 : 0) as major cellular fatty acids. On the basis of DNA-DNA relatedness and physiological and biochemical characterization, strain 5YN1-3(T) should be assigned to a novel species of the genus Aquitalea, for which the name Aquitalea denitrificans sp. nov. is proposed. The type strain is 5YN1-3(T) (=KACC 12729(T) =DSM 21300(T)).

Rubellimicrobium aerolatum sp. nov., isolated from an air sample in Korea

A pink-coloured bacterial strain, designated 5715S-9(T), was isolated from an air sample collected in Suwon, Republic of Korea. The cells were strictly aerobic, Gram-negative, non-spore-forming, non-flagellated and short-rod-shaped. On the basis of 16S rRNA gene sequence analysis, the organism was a member of the genus Rubellimicrobium, showing the highest sequence similarities with Rubellimicrobium mesophilum MSL-20(T) (96.2 % sequence similarity) and Rubellimicrobium thermophilum DSM 16684(T) (93.9 %). The major polar lipids were phosphatidylglycerol, phosphatidylcholine, diphosphatidylglycerol, phosphatidylethanolamine and an unidentified glycolipid. The major fatty acids (>10 %) were C(18 : 1)omega7c, C(16 : 0) and 11-methyl C(18 : 1)omega7c. The G+C content of the DNA was 69 mol%. On the basis of both phylogenetic and phenotypic evidence, strain 5715S-9(T) represents a novel species of the genus Rubellimicrobium, for which the name Rubellimicrobium aerolatum sp. nov. is proposed. The type strain is 5715S-9(T) (=KACC 12504(T)=DSM 19297(T)).

Central lymph node metastases in unilateral papillary thyroid microcarcinoma

BACKGROUND

The indications for and appropriate extent of prophylactic central lymph node (CLN) dissection for clinically node-negative patients with unilateral papillary thyroid microcarcinoma (PTMC) are unknown.

METHODS

The frequency, patterns and predictive factors for CLN metastases in 86 patients with unilateral PTMC and a clinically node-negative neck were analysed with respect to age and sex; metastasis, age, completeness, invasiveness, size (MACIS) score; tumour size; number and location of tumours; presence of ipsilateral CLN metastases; and presence of lymphovascular or capsular invasion. All patients underwent total thyroidectomy and CLN dissection.

RESULTS

Twenty-seven (31 per cent) of 86 patients had metastatic CLNs: 18 ipsilateral and nine bilateral. Univariable analysis suggested male sex and tumour size greater than 0.5 cm to be significant factors in predicting ipsilateral CLN metastases. Only ipsilateral nodal positivity was a significant predictor of contralateral CLN metastases in multivariable analysis (P = 0.007).

CONCLUSION

CLN metastases are relatively common in PTMC.

Sialolithiasis in a stump of Wharton's duct of an aplastic unilateral submandibular gland

Congenital absence of the salivary glands is an uncommon disorder. Isolated aplasia of a unilateral submandibular gland is rare and only 6 cases have been reported. The formation of a sialolith within the remaining Wharton's duct, associated with isolated aplasia of a unilateral submandibular gland, has not been reported previously. The authors report two cases of sialolithiasis within the ipsilateral remaining Wharton's duct in patients with isolated aplasia of a unilateral submandibular gland.

Characterization of a gene encoding cellulase from uncultured soil bacteria

To detect cellulases encoded by uncultured microorganisms, we constructed metagenomic libraries from Korean soil DNAs. Screenings of the libraries revealed a clone pCM2 that uses carboxymethyl cellulose (CMC) as a sole carbon source. Further analysis of the insert showed two consecutive ORFs (celM2 and xynM2) encoding proteins of 226 and 662 amino acids, respectively. A multiple sequence analysis with the deduced amino acid sequences of celM2 showed 36% sequence identity with cellulase from the Synechococcus sp., while xynM2 had 59% identity to endo-1,4-beta-xylanase A from Cellulomonas pachnodae. The highest enzymatic CMC hydrolysis was observable at pH 4.0 and 45 degrees C with recombinant CelM2 protein. Although the enzyme CelM2 additionally hydrolyzed avicel and xylan, no substrate hydrolysis was observed on oligosaccharides such as cellobiose, pNP-beta-cellobioside, pNP-beta-glucoside, and pNP-beta-xyloside. These results showed that CelM2 is a novel endo-type cellulase.

Methylobacterium oryzae sp. nov., an aerobic, pink-pigmented, facultatively methylotrophic, 1-aminocyclopropane-1-carboxylate deaminase-producing bacterium isolated from rice

A pink-pigmented, facultatively methylotrophic bacterium, strain CBMB20T, isolated from stem tissues of rice, was analysed by a polyphasic approach. Strain CBMB20T utilized 1-aminocyclopropane 1-carboxylate (ACC) as a nitrogen source and produced ACC deaminase. It was related phylogenetically to members of the genus Methylobacterium. 16S rRNA gene sequence analysis indicated that strain CBMB20T was most closely related to Methylobacterium fujisawaense, Methylobacterium radiotolerans and Methylobacterium mesophilicum; however, DNA-DNA hybridization values were less than 70 % with the type strains of these species. The DNA G+C content of strain CBMB20T was 70.6 mol%. The study presents a detailed phenotypic characterization of strain CBMB20T that allows its differentiation from other Methylobacterium species. In addition, strain CBMB20T is the only known member of the genus Methylobacterium to be described from the phyllosphere of rice. Based on the data presented, strain CBMB20T represents a novel species in the genus Methylobacterium, for which the name Methylobacterium oryzae sp. nov. is proposed, with strain CBMB20T (=DSM 18207T=LMG 23582T=KACC 11585T) as the type strain.

Aurantimonas ureilytica sp. nov., isolated from an air sample

A novel strain, designated 5715S-12T, was isolated from an air sample collected from Suwon region, Republic of Korea, using R2A medium. The cells were strictly aerobic, Gram-negative, motile, short rods. Comparison of the 16S rRNA gene sequence of strain 5715S-12T showed the highest sequence similarities to Aurantimonas altamirensis S21BT (95.9 %) and Aurantimonas coralicida WP1T (95.4 %). Phylogenetic trees indicated that the strain formed a cluster with members of the family Aurantimonadaceae (A. altamirensis, A. coralicida and Fulvimarina pelagi). The major fatty acid was C18 : 1 ω7c. The predominant isoprenoid quinone was ubiquinone 10 (Q-10). Diphosphatidylglycerol, phosphatidylmonomethylethanolamine, phosphatidylethanolamine, phosphatidyldimethylethanolamine, phosphatidylglycerol, phosphatidylcholine and four unknown lipids were found as the polar lipid components. The DNA G+C content was 67.0 mol%. On the basis of the phenotypic and phylogenetic features studied, we propose that strain 5715S-12T be assigned to a novel species of the genus Aurantimonas, for which the name Aurantimonas ureilytica sp. nov. (type strain 5715S-12T =KACC 11607T =DSM 18598T) is proposed.

Screening and characterization of an enzyme with beta-glucosidase activity from environmental DNA

A novel beta-glucosidase gene, bglA, was isolated from uncultured soil bacteria and characterized. Using genomic libraries constructed from soil DNA, a gene encoding a protein that hydrolyzes a fluorogenic analog of cellulose, 4-methylumbelliferyl beta-D-cellobioside (MUC), was isolated using a microtiter plate assay. The gene, bglA, was sequenced using a shotgun approach, and expressed in E. coli. The deduced 55-kDa amino acid sequence for bglA showed a 56% identity with the family 1 glycosyl hydrolase Chloroflexus aurantiacus. Bg1A included two conserved family 1 glycosyl hydrolase regions. When using p-nitrophenyl-beta-D-glucoside (pNPG) as the substrate, the maximum activity of the purified beta-glucosidase exhibited at pH 6.5 and 55 degrees C, and was enhanced in the presence of Mn2+. The Km and Vmax values for the purified enzyme with pNPG were 0.16 mM and 19.10 micromol/min, respectively. The purified BglA enzyme hydrolyzed both pNPG and p-nitrophenyl-beta-D-fucoside. The enzyme also exhibited substantial glycosyl hydrolase activities with natural glycosyl substrates, such as sophorose, cellobiose, cellotriose, cellotetraose, and cellopentaose, yet low hydrolytic activities with gentiobiose, salicin, and arbutin. Moreover, Bg1A was able to convert the major ginsenoside Rb1 into the pharmaceutically active minor ginsenoside Rd within 24 h.

Generation of a specific marker to discriminate Gacillus anthracis from other bacteria of the Bacillus cereus group

Bacillus anthracis is a soil pathogen capable of causing anthrax that is closely related to several environmental species, including B. cereus, B. mycoides, and B. thuringiensis. DNA homology studies showed that B. anthracis, B. cereus, B. mycoides, and B. thuringiensis are closely related, with a high sequence homology. To establish a method to specifically detect B. anthracis in situations such as environmental contamination, we initially performed RAPD-PCR with a 10-mer random primer and confirmed the presence of specific PCR bands only in B. anthracis species. One region specific for B. anthracis was cloned and sequenced, and an internal primer set was designed to amplify a 241-bp DNA fragment within the sequenced region. The PCR system involving these specific primer sets has practical applications. Using lyses methods to prepare the samples for PCR, it was possible to quickly amplify the 241-bp DNA segment from samples containing only a few bacteria. Thus, the PCR detection method developed in this study is expected to facilitate the monitoring of environmental B. anthracis contamination.

Idiomarina homiensis sp. nov., isolated from seashore sand in Korea

A halophilic, aerobic bacterium, designated PO-M2(T), was isolated from seashore sand, from Pohang, Korea and characterized on the basis of physiological and biochemical features. Phylogenetic analysis of 16S rRNA gene sequences revealed a clear affiliation of the novel strain with members of the genus Idiomarina. Sequence similarities between strain PO-M2(T) and the type strains of species belonging to the genus Idiomarina ranged from 94.3 to 95.5 %. Cells of strain PO-M2(T) were straight or slightly curved rods and formed light-yellow colonies on marine agar medium. The major isoprenoid quinone was ubiquinone (Q-8) and the predominant cellular fatty acids were C(15 : 0) iso (19.3 %), C(17 : 1)omega9c iso (11.9 %), C(17 : 0) iso (10.9 %), C(18 : 1)omega7c (10.4 %), C(16 : 0) (9.0 %) and C(16 : 1)omega7c and/or C(15 : 0) iso 2-OH (7.2 %). The G+C content of the DNA was 45.1 mol%. Based on physiological, biochemical and chemotaxonomic traits and comparative 16S rRNA gene sequence analysis, it is demonstrated that the isolate represents a novel species of the genus Idiomarina, for which the name Idiomarina homiensis sp. nov. is proposed. The type strain is PO-M2(T) (=KACC 11514(T)=DSM 17923(T)).

Development of high-throughput assay of lethal factor using native substrate

The design of inhibitors for anthrax lethal factor (LF) is currently of interest as an approach for the treatment of anthrax because LF plays a major role in the cytotoxicity of target cells. LF is a zinc-dependent metalloprotease that specifically cleaves the mitogen-activated protein kinase kinase (MKK) family. Current assay systems for the screening of LF inhibitor use the optimized synthetic peptide coupled with various kinds of fluorophores, enabling fast, sensitive, and robust assays suited to high-throughput screening. However, evidence suggests that the regions beside the cleavage site are also involved in specificity and proteolytic activity of LF. In the current study, we tried to develop a high-throughput assay for LF activity based on native substrate, mitogen-activated ERK kinase 1 (MEK1). The assay system relies on the enhanced chemiluminescence signal resulting from a specific antibody against the C-terminal region of native substrate. A glutathione-coated multiwell plate was used as a solid support to immobilize the native substrate by its N-terminal glutathione-S-transferase moiety. Immobilized substrate increases the specificity and sensitivity of LF-catalyzed substrate hydrolysis compared with the solution phase assay. This assay system might be used to discover a wide spectrum of anthrax inhibitors.

The genome sequence of Xanthomonas oryzae pathovar oryzae KACC10331, the bacterial blight pathogen of rice

The nucleotide sequence was determined for the genome of Xanthomonas oryzae pathovar oryzae (Xoo) KACC10331, a bacterium that causes bacterial blight in rice (Oryza sativa L.). The genome is comprised of a single, 4 941 439 bp, circular chromosome that is G + C rich (63.7%). The genome includes 4637 open reading frames (ORFs) of which 3340 (72.0%) could be assigned putative function. Orthologs for 80% of the predicted Xoo genes were found in the previously reported X.axonopodis pv. citri (Xac) and X.campestris pv. campestris (Xcc) genomes, but 245 genes apparently specific to Xoo were identified. Xoo genes likely to be associated with pathogenesis include eight with similarity to Xanthomonas avirulence (avr) genes, a set of hypersensitive reaction and pathogenicity (hrp) genes, genes for exopolysaccharide production, and genes encoding extracellular plant cell wall-degrading enzymes. The presence of these genes provides insights into the interactions of this pathogen with its gramineous host.

Targeting of Bacillus anthracis interaction factors for human macrophages using two-dimensional gel electrophoresis

Bacillus anthracis, a gram-positive, endospore-forming, aerobic rod-shaped bacterium, interacts with macrophages at various stages of the disease. Spore germination and the outgrowth of vegetative bacilli are crucial steps enabling the bacteria to proliferate actively and to synthesize the virulence factors leading to a massive septicemia. In this study, we performed a proteomic analysis and MALDI-TOF/MS were carried out to identify proteins using human macrophages infected with the spores of B. anthracis live-Sterne or inactivated-Sterne. We identified 21 proteins which are related to the infection of B. anthracis spores on human macrophages at the early stage events. These proteins function in processes such as cytoskeleton regulation, apoptosis, cell division, and protein degradation. Proteins such as PAK 2 revealed a relationship to apoptosis in human macrophages. These proteins play an important role in the macrophage survival and death on human macrophages with infected B. anthracis spores.

The Seoul Metropolitan Preschool Vision Screening Programme: results from South Korea

AIM

To report on a new model of preschool vision screening that was performed in metropolitan Seoul and to investigate the distribution of various ocular disorders in this metropolitan preschool population.

METHODS

Vision screening was conducted on 36 973 kindergarten children aged 3-5 years in a stepwise manner. The first step was home screening using a set of five picture cards and a questionnaire. The children who did not pass the first step (VA <0.5 in at least one eye or any abnormal responses on the questionnaire) were retested with regular vision charts at the regional public healthcare centres. After this retest, some children were referred to ophthalmologists. The referral criteria for visual acuity were <0.5 at 3 years and <0.63 at 4 or 5 years in at least one eye.

RESULTS

Of those screened, 7116 (19.2%) children did not pass the home screening tests and 2058 (28.9%) out of the 7116 were referred. The results of the ophthalmological examination in eye clinics were only available for 894 children (43.4%) of those who were referred. The rest of the children did not visit ophthalmologists because they had been checked at an eye clinic, were currently under treatment, or for personal reasons. Refractive errors were found in 608 (1.6%) children. Astigmatism was associated in 78.2% of ametropes. Amblyopia was discovered in 149 (0.4%) children and refractive error was the major aetiology with a predominant rate (82.5%). Manifest strabismus was detected in 52 children. The positive predictive value of vision screening for any ophthalmological disorder was 0.77, and 0.49 for significant disorders requiring treatment.

CONCLUSIONS

This preschool vision screening model was highly accessible to the children and their parents, easy to administer, and effective to detect a variety of ocular disorders. However, the participation rate of the referred children in the examinations by ophthalmologists was quite low. The performance and efficiency of this screening programme need to be optimised with further revision.

Production and proteolytic assay of lethal factor from Bacillus anthracis

Bacillus anthracis is the causative agent of anthrax. The major virulence factors are a poly-D-glutamic acid capsule and three-protein component exotoxin, protective antigen (PA, 83 kDa), lethal factor (LF, 90 kDa), and edema factor (EF, 89 kDa), respectively. These three proteins individually have no known toxic activities, but in combination with PA form two toxins (lethal toxin or edema toxin), causing different pathogenic responses in animals and cultured cells. In this study, we constructed and produced rLF as a form of GST fusion protein in Escherichia coli. rLF was rapidly purified through a single affinity purification step to near homogeneity. Furthermore, we developed an in vitro immobilized proteolytic assay of LF under the condition containing full-length native substrate, MEK1, rather than short synthetic peptide. The availability of full-length substrate and of an immobilized LF assay could facilitate not only the in-depth investigation of structure-function relationship of the enzyme toward its substrate but also wide spectrum screening of inhibitor collections based on the 96-well plate system.

The thin latissimus dorsi perforator-based free flap for resurfacing

The authors present their experience with "thin" latissimus dorsi perforator-based free flaps for resurfacing defects. Perforator-based free flaps have been used for various kinds of reconstruction by presenting important donor structures. The thin latissimus dorsi perforatorbased free flap included only the skin and superficial adipose layer to reduce its bulkiness by dissection through the superficial fascial plane. This flap was used in 12 clinical cases, without flap necrosis or other serious postoperative complications. All of the patients were examined by preoperative power Doppler ultrasound in the spectral Doppler mode to search for the most reliable perforator. This noninvasive ultrasound technique determines the exact location and course of and ensures the reliable flow of the perforators; therefore, it greatly assists microsurgeons in saving operation time and in selecting the most suitable design for perforator flap reconstruction. We used perforators that were identified several centimeters from the lateral border of the latissimus dorsi muscle. The thin flap dimensions could be safely designed for flaps measuring up to 20 cm in length and 8 cm in width for primary closure of the donor site. Generally, a long pedicle is not required for resurfacing reconstructions, where small recipient arteries in the bed are acceptable for anastomosis with pedicles. However, pedicle dissection to the proximal vessels through the latissimus dorsi muscle was required when it was necessary to match the recipient vein for anastomosis. The authors conclude that this thin latissimus dorsi perforator-based free flap has great potential for resurfacing because of its constant thickness, easy elevation with the help of power Doppler ultrasound information, and proper flap size for moderate defects caused by scar contracture release, superficial tumor ablation, and so on.

Hepatic involvement in hypereosinophilia: sonographic findings

Hypereosinophilic syndrome may cause eosinophil-related tissue damage to various organs. The purpose of this paper is to describe sonographic findings in 13 patients with hypereosinophilia in whom the liver was involved. The diagnosis in these 13 patients was based on liver biopsy in seven patients with bone marrow biopsy in six patients. Eight patients had hypereosinophilic syndrome and five patients had clonorchiasis. All 13 patients had mild to marked hepatomegaly. Seven of 13 patients showed multiple round or oval hypoechoic (n = 6) or variably echogenic (n = 1) lesions measuring 1 to 2 cm with poorly defined margins in both lobes of the liver. Four patients had one or two hypoechoic lesions 3 to 4 cm in size, with geographic pattern and poorly defined margins. Two patients showed diffuse hepatomegaly with increased parenchymal echogenicity. The number of lesions and the extent of diffuse lesions seem to be proportional to the degree of eosinophilia. Hypereosinophilia may produce multiple small focal hepatic lesions or diffuse segmental or lobar echogenic lesions simulating primary or metastatic tumor of the liver.

Change of plasma lipoproteins by heparin-released lipoprotein lipase

Lipoprotein lipase (LPL) is known to be attached to the luminal surface of vascular endothelial cells in a complex with membrane-bound heparan sulfate, and released into blood stream by heparin. LPL that catalyzes hydrolysis of triglyceride (TGL) on chylomicron and VLDL into two fatty acids and monoacylglycerol, is also implicated to participate in an enhancement of cholesterol uptake by arterial endothelial cells in vitro. But little is known about the LPL-mediated cholesterol uptake in physiological state. In this study, changes in blood lipid composition and levels of lipoproteins were determined after the injection of heparin in human. The level of LPL in plasma was increased from 0 to 11 mU/ml within 30-40 min post-heparin administration and decreased to the basal level within 2 h. The level of TGL in plasma decreased from 70 mg/dl to 20 mg/dl within 1 h and gradually increased to 80 mg/dl within 4 h. However the level of total cholesterol in plasma remained at 140 mg/dl during an experimental period of 4 h. Analysis of Lipoproteins in plasma by NaBr density gradient ultracentrifugation showed that the level of VLDL decreased from 50 mg/dl to 10 mg/dl within 1-2 h and returned to normal plasm level at 4 h. However there were no significant changes in the level of LDL and HDL. These results suggest that, at least, in normo-lipidemic subjects, increased free plasm LPL acts primarily on VLDL and failed to show any significant uptake of cholesterol-rich lipoproteins in human.

Genetic variations at four tetrameric tandem repeat loci in Korean population

Allele and genotype frequencies for four tetrameric short tandem repeat (STR) loci, HumFES/FPS, HumFOLP23, HumGABRB15, and HumCYAR04, have been determined by polymerase chain reaction (PCR) amplification and subsequent polyacrylamide gel electrophoresis from approximately 200 genetically unrelated Koreans. This method allows a single base pair resolution and rapid typing with silver staining. The allele and genotype distributions satisfy Hardy-Weinberg expectation. Also, these STR loci have proven to be useful for forensic analyses and paternity tests in which the variable number of tandem repeat (VNTR) loci have some limitations.

Efficacy of ciprofloxacin and dexamethasone in experimental pseudomonas endophthalmitis

To determine injection time and effective dose of ciprofloxacin in endophthalmitis and to evaluate the effectiveness of dexamethasone. In rabbits, Pseudomonas aeruginosa (2 x 10(4) CFU/0.1 ml) was inoculated intravitreally. At 6, 12, 18, 24 hours postinoculation, single intravitreal doses of ciprofloxacin (300 micrograms/0.15 ml or 100 micrograms/0.05 ml) alone or with dexamethasone (400 micrograms) were given. Electrophysiological and histologic measures were utilized to rate drug effectiveness. 300 micrograms ciprofloxacin was effective in killing P. aeruginosa at 6 and 12 hours postinoculation, but one hundred ug ciprofloxacin was not effective. 300 ug ciprofloxacin had no significant effect in killing P. aeruginosa at 18 hrs and 24 hrs postinoculation. Eyes treated with dexamethasone (400 micrograms) and ciprofloxacin (300 micrograms) at 6 hours postinoculation did not differ from eyes treated with ciprofloxacin alone. Cultures from eyes treated with dexamethasone and ciprofloxacin at 12 hours postinoculation were positive. Cultures from eyes treated with ciprofloxacin alone were negative. The failure of treatment at 18 hrs and 24 hrs postinoculation may be due to either an increased rate of clearance of drugs from the eyes or a reduced bactericidal effect of ciprofloxacin which could be altered by acidic pH, degree of hypoxia or bacterial counts. Dexamethasone had no beneficial effect in the treatment of P. aeruginosa endophthalmitis in the early phase.