Optimization of selective emitter fabrication method for solar cells using a laser grooving

In this paper, screen-printing laser grooved buried contact (LGBC) method was applied, which is compatible with the existing screen-printed solar cell equipment and facilities. Experiments were performed in order to optimize short circuit current (I(sc)), open circuit voltage (V(oc)) and fill factor of high efficiency solar cells. To enhance I(sc), V(oc) and efficiency, heavy doping was performed at low sheet resistance in the laser grooved region of the cell. In contrast, light doping was carried out at a high sheet resistance in the non-laser grooved region. To increase fill factor, porous silicon found on the wafer after dipping in an HF solution to remove SiN(x), was cleared. The fabricated screen-printing LGBC solar cell using a 125 mm x 125 mm single crystalline silicon wafer exhibited an efficiency of 17.2%. The results show that screen-printing LGBC method can be applied for high efficiency solar cells.

Tonic extrasynaptic GABA(A) receptor currents control gonadotropin-releasing hormone neuron excitability in the mouse

It is well established that the GABA(A) receptor plays an important role in regulating the electrical excitability of GnRH neurons. Two different modes of GABA(A) receptor signaling exist: one mediated by synaptic receptors generating fast (phasic) postsynaptic currents and the other mediated by extrasynaptic receptors generating a persistent (tonic) current. Using GABA(A) receptor antagonists picrotoxin, bicuculline methiodide, and gabazine, which differentiate between phasic and tonic signaling, we found that ∼50% of GnRH neurons exhibit an approximately 15-pA tonic GABA(A) receptor current in the acute brain slice preparation. The blockade of either neuronal (NO711) or glial (SNAP-5114) GABA transporter activity within the brain slice revealed the presence of tonic GABA signaling in ∼90% of GnRH neurons. The GABA(A) receptor δ subunit is only found in extrasynaptic GABA(A) receptors. Using single-cell RT-PCR, GABA(A) receptor δ subunit mRNA was identified in GnRH neurons and the δ subunit-specific agonist 4,5,6,7-tetrahydroisoxazolo [5,4-c] pyridin-3-ol was found to activate inward currents in GnRH neurons. Perforated-patch clamp studies showed that 4,5,6,7-tetrahydroisoxazolo [5,4-c] pyridin-3-ol exerted the same depolarizing or hyperpolarizing effects as GABA on juvenile and adult GnRH neurons and that tonic GABA(A) receptor signaling regulates resting membrane potential. Together, these studies reveal the presence of a tonic GABA(A) receptor current in GnRH neurons that controls their excitability. The level of tonic current is dependent, in part, on neuronal and glial GABA transporter activity and mediated by extrasynaptic δ subunit-containing GABA(A) receptors.

Neurosteroid modulation of benzodiazepine-sensitive GABAA tonic inhibition in supraoptic magnocellular neurons

Interactions between neurosteroids and GABA receptors have attracted particular attention in the supraoptic nucleus (SON). Although GABA(A) receptors (GABA(A)R) mediate a sustained tonic inhibitory current (I(tonic)), as well as conventional phasic inhibitory postsynaptic currents (IPSCs, I(phasic)) in the SON, whether the steroid modulation on I(tonic) is present in SON magnocelluar neurosecretory cells (MNCs) is unknown. Here, we addressed this question and gained insights into the potential molecular configuration of GABA(A) receptors mediating I(tonic) and conferring its neurosteroids sensitivity in SON MNCs. 4,5,6,7-tetrahydroisoxazolo[5,4-c]-pyridin-3-ol (THIP) (1 μM), a relatively selective extrasynaptic GABA(A)R agonist, facilitated I(tonic) without affecting the main characteristics of IPSCs, while DS-2, a relatively selective modulator of GABA(A)R δ-subunits, caused minimal changes in I(tonic) of SON MNCs. l-655,708, a relatively selective GABA(A)R α(5)-subunit inverse agonist, blocked ∼35% of the total I(tonic) both under basal and elevated ambient GABA concentration (3 μM). Facilitation of I(tonic) by benzodiazepines further supported the role of GABA(A)R γ(2)-subunit in I(tonic) of SON MNCs. Quantitative RT-PCR analysis showed much lesser expression of GABA(A)R δ-subunit than the α(5) or γ(2)-subunit in the SON. Allopregnanolone and 3α,5α-tetrahydrodeoxycorticosterone increased both I(tonic) and I(phasic) in SON MNCs, respectively, although more than 90% of the current increase was mediated by I(tonic) during the neurosteroid facilitation. Finally, l-655,708 attenuated the neurosteroid facilitation of I(tonic) but not of I(phasic). Altogether, our results suggest that I(tonic), mediated mainly by benzodiazepine-sensitive GABA(A)Rs containing α(5)-, β-, and γ(2)-, and to a lesser extent, δ-subunits, is a potential target of neurosteroid modulation in SON neurons.

Unexplained Massive Pneumoperitoneum following Cardiopulmonary Resuscitation

Pneumoperitoneum following cardiopulmonary resuscitation (CPR) had been described as a rare complication. Pneumoperitoneum after CPR could be due to gastric perforation or intrathoracic air tracking into the abdominal cavity via the diaphragm as a result of bag-valve-mask ventilation, external chest compression or improper intubation. In most reported cases, the specific injuries could be identified. We reported an unusual case of pneumoperitoneum following CPR in which the specific cause was not definitely established. Emergency physicians should be aware of the mechanism and clinical signs suggesting of pneumoperitoneum during or after CPR.

Expression of KA1 kainate receptor subunit in the substantia gelatinosa of the trigeminal subnucleus caudalis in mice

The KA1 kainate receptor (KAR) subunit in the substantia gelatinosa (SG) of the trigeminal subnucleus caudalis (Vc) has been implicated in the processing of nociceptive information from the orofacial region. This study compared the expression of the KA1 KAR subunit in the SG of the Vc in juvenile, prepubescent and adult mice. RT-PCR, Western blot and immunohistochemistry analyses were used to examine the expression level in SG area. The expression levels of the KA1 KAR subunit mRNA and protein were higher in juvenile mice than in prepubescent or adult mice. Quantitative data revealed that the KA1 KAR subunit mRNA and protein were expressed at levels approximately two and three times higher, respectively, in juvenile mice than in adult mice. A similar expression pattern of the KA1 KAR subunit was observed in an immunohistochemical study that showed higher expression in the juvenile (59%) than those of adult (35%) mice. These results show that the KA1 KAR subunits are expressed in the SG of the Vc in mice and that the expression level of the KA1 KAR subunit decreases gradually with postnatal development. These findings suggest that age-dependent KA1 KAR subunit expression can be a potential mechanism of age-dependent pain perception.

Effects of 5-hydroxytryptamine on substantia gelatinosa neurons of the trigeminal subnucleus caudalis in immature mice

Serotonin (5-hydroxytryptamine, 5-HT) is involved in the descending modulation of nociceptive transmission in the spinal dorsal horn. The trigeminal subnucleus caudalis (Vc; medullary dorsal horn) processes nociceptive input from the orofacial region, and 5-HT-containing axons are numerous in the superficial layers of the Vc. This study examined the actions of 5-HT on the substantia gelatinosa (SG) neurons of the Vc, using gramicidin-perforated patch-clamp recording in brainstem slice preparations from immature mice. In order to clarify the possible mechanisms underlying 5-HT actions in the SG of the Vc, the direct membrane effects of 5-HT and effects of 5-HT receptor subtype agonists were examined. 5-HT induced a hyperpolarization in the majority (64/115, 56%) of the SG neurons tested. Thirty nine (34%) SG neurons showed no response, and 12 (10%) neurons responded with depolarization. The hyperpolarizing response to 5-HT was concentration-dependent (0.1-30 μM; n=7), not desensitized by repeated application (n=22), and significantly attenuated by Ba(2+) (K(+) channel blocker; n=8). The 5-HT-induced hyperpolarization was maintained in the presence of TTX (Na(+) channel blocker), CNQX (non-NMDA glutamate receptor antagonist), AP5 (NMDA glutamate receptor antagonist), picrotoxin (GABA(A) receptor antagonist), and strychnine (glycine receptor antagonist), indicating direct postsynaptic action of 5-HT on SG neurons (n=7). The 5-HT-induced hyperpolarizing effects were mimicked by 8-OH-DPAT (5-HT(1A) receptor agonist) and α-methyl-5-HT (5-HT(2) receptor agonist) and blocked by WAY-100635 (5-HT(1A) receptor antagonist) and ketanserin (5-HT(2) receptor antagonist). Single-cell RT-PCR also revealed the presence of mRNA for 5-HT(1A) and 5-HT(2C) subtypes in the SG neurons. These results suggest that 5-HT acts directly on SG neurons and 5-HT-induced hyperpolarization is mediated, in part, by 5-HT(1A) receptors and 5-HT(2) receptors, as well as by the activation of K(+) channels, indicating an important role for 5-HT in the modulation of orofacial nociceptive processing at the level of the SG of the Vc in mice.

Risk factors for multidrug-resistant bacterial infection among patients with tuberculosis

Given that anti-tuberculosis medication itself has antibacterial activity and that broad-spectrum antibiotics are frequently used, the emergence of multidrug-resistant (MDR) bacteria among patients being treated for tuberculosis (TB) is likely. We used a case-control design to study the clinical predictors of MDR bacterial infection among TB patients. Both cases and controls were selected from among patients who were diagnosed and treated as having TB between 1 January 1996 and 31 August 2006. TB patients with MDR bacterial infection were included as cases and those with non-MDR bacterial infection were included as controls. Multiple logistic regression analysis was performed to elucidate the risk factors for MDR bacterial infection. During the study period 3667 patients were diagnosed with, and treated for, TB. A total of 123 experienced episodes of bacterial infection, of whom 59 (48.0%) were infected by an MDR strain at least once. The presence of chronic renal failure [adjusted odds ratio (OR): 4.96; 95% confidence interval (CI): 1.37-18.01] and the use of antimicrobials other than typical anti-TB drugs within three months (adjusted OR: 4.37; 95% CI: 1.74-10.95) were independent risk factors for MDR bacterial infection. Bacterial infection in TB patients is commonly multidrug resistant. Clinicians should be aware of the possibility of MDR bacterial infection among TB patients with chronic renal failure or recent use of other antimicrobials.

Effects of human growth hormone on gonadotropin-releasing hormone neurons in mice

Purpose

Recombinant human growth hormone (rhGH) has been widely used to treat short stature. However, there are some concerns that growth hormone treatment may induce skeletal maturation and early onset of puberty. In this study, we investigated whether rhGH can directly affect the neuronal activities of of gonadotropin-releasing hormone (GnRH).

Methods

We performed brain slice gramicidin-perforated current clamp recording to examine the direct membrane effects of rhGH on GnRH neurons, and a whole-cell voltage-clamp recording to examine the effects of rhGH on spontaneous postsynaptic events and holding currents in immature (postnatal days 13-21) and adult (postnatal days 42-73) mice.

Results

In immature mice, all 5 GnRH neurons recorded in gramicidin-perforated current clamp mode showed no membrane potential changes on application of rhGH (0.4, 1 µg/mL). In adult GnRH neurons, 7 (78%) of 9 neurons tested showed no response to rhGH (0.2-1 µg/mL) and 2 neurons showed slight depolarization. In 9 (90%) of 10 immature neurons tested, rhGH did not induce any membrane holding current changes or spontaneous postsynaptic currents (sPSCs). There was no change in sPSCs and holding current in 4 of 5 adult GnRH neurons.

Conclusion

These findings demonstrate that rhGH does not directly affect the GnRH neuronal activities in our experimental model.

Rapid increase of non-tuberculous mycobacterial lung diseases at a tertiary referral hospital in South Korea

The incidence of non-tuberculous mycobacteria (NTM) disease is thought to correlate negatively with the tuberculosis (TB) burden. To determine the recent trend in the number of patients with NTM lung disease at a tertiary referral hospital in South Korea, where the incidence of TB has been stationary, a retrospective analysis was performed. From 2002 to 2008, the number of patients with NTM lung diseases increased from 82 to 133, while the number of TB patients decreased from 436 to 276. NTM lung diseases might be increasing in South Korea despite the stationary incidence of TB.

Somatostatin inhibition of gonadotropin-releasing hormone neurons in female and male mice

Previous studies indicate that somatostatin regulates gonadotropin secretion. We investigated here whether somatostatin has direct effects on GnRH neurons in the adult male and female mice. Dual-labeling immunofluorescence experiments revealed the presence of somatostatin-immunoreactive fibers adjacent to GnRH neurons, and three-dimensional confocal reconstructions demonstrated apparent somatostatin fiber appositions with 50-60% of GnRH neurons located throughout the brain in both male and female mice. Perforated patch-clamp recordings from GnRH-green fluorescent protein neurons revealed that approximately 70% of GnRH neurons responded in a dose-dependent manner to 10-300 nm somatostatin with an acute membrane hyperpolarization and cessation of firing. This effect persisted in the presence of tetrodotoxin and amino acid receptor antagonists, indicating a direct postsynaptic site of action on the GnRH neuron. The identity of the somatostatin receptors underlying this action was assessed using GnRH neuron single-cell RT-PCR. Of the somatostatin receptor subtypes, the sstr2 transcript was the most prevalent and detected in both males and females. The expression of sstr2 by GnRH neurons was confirmed in the sstr2 knockout/LacZ knock-in mouse line. Electrophysiological studies demonstrated that the sstr2-selective agonist seglitide exerted acute hyperpolarizing actions on GnRH neurons identical to those of somatostatin. Together, these studies reveal somatostatin, acting through sstr2, to be one of the most potent inhibitors of electrical excitability of male and female GnRH neurons identified thus far.

Postnatal change of GluR5 kainate receptor expression in the substantia gelatinosa neuron of the trigeminal subnucleus caudalis in mice

The substantia gelatinosa (SG) of the trigeminal subnucleus caudalis (Vc) has been implicated in the processing of nociceptive information from the orofacial region. Kainate receptors (KARs) play an important role in sensory transmission. Five different KAR subunits have been cloned and the expression of the KAR subunits showed developmental changes. In this study, RT-PCR, western blotting, immunohistochemistry and a patch clamp technique were used examine the functional expression of the GluR5 subunit in the SG of the Vc in juvenile, peripubertal and/or adult mice. The levels of mRNA and protein expression of the GluR5 subunit in the SG of the Vc were higher in the juvenile mice than in the peripubertal or adult mice. In addition, the KA and ATPA, a GluR5 KAR agonist, induced membrane depolarization on the SG neurons in both juvenile and adult mice in a concentration-dependent manner. However, the juvenile SG neurons showed a stronger response to KA and ATPA than those of adults. The membrane depolarization by KA was suppressed slightly in the presence of the AMPA receptor antagonist, GYKI 52466. These results show that the GluR5 KAR subunits are expressed functionally on the SG neurons of the Vc in mice, and the expression levels of the GluR5 subunits decrease with postnatal development. These postnatal changes in the GluR5 KAR subunit may be a possible mechanism for age-dependent pain processing.

ConPlex: a server for the evolutionary conservation analysis of protein complex structures

Evolutionary conservation analyses are important for the identification of protein-protein interactions. For protein complex structures, sequence conservation has been applied to determine protein oligomerization states, to characterize native interfaces from non-specific crystal contacts, and to discriminate near-native structures from docking artifacts. However, a user-friendly web-based service for evolutionary conservation analysis of protein complexes has not been available. Therefore, we developed ConPlex (http://sbi.postech.ac.kr/ConPlex/) a web application that enables evolutionary conservation analyses of protein interactions within protein quaternary structures. Users provide protein complex structures; ConPlex automatically identifies protein interfaces and carries out evolutionary conservation analyses for the interface regions. Moreover, ConPlex allows the results of the residue-specific conservation analysis to be displayed on the protein complex structure and provides several options to customize the display output to fit each user's needs. We believe that ConPlex offers a convenient platform to analyze protein complex structures based on evolutionary conservation of protein-protein interface residues.

The impact of insulin sensitisers on lung function in patients with chronic obstructive pulmonary disease and diabetes

SETTING

It has been reported that diabetes mellitus (DM) is associated with poor pulmonary function, which could be explained by insulin resistance.

OBJECTIVE

To evaluate whether insulin sensitisers (ISs) have beneficial effects on lung function in patients with chronic obstructive pulmonary disease (COPD) and DM.

DESIGN

This retrospective study included patients with both COPD and DM who attended Seoul National University Hospital for treatment between 1 January 2000 and 31 August 2007. They were treated with inhalers for COPD and oral hypoglycaemia agents, including ISs or insulin, for DM. The primary outcome was a change in lung function in spirometric examinations.

RESULTS

Among 61 patients enrolled, 32 were in the no IS group, while 29 were in the IS group. On multivariable regression analysis, the IS group showed a significantly greater change in forced vital capacity (FVC) than the no IS group (adjusted beta-coefficient 131.9, 95%CI 8.5-255.4, P = 0.04).

CONCLUSIONS

Treatment with an IS was independently associated with improvements in FVC in patients with both COPD and DM, compared with treatment without IS.

The impact of nutritional deficit on mortality of in-patients with pulmonary tuberculosis

SETTING

A metropolitan governmental medical centre, Seoul, Republic of Korea.

OBJECTIVE

To elucidate the impact of the nutritional deficit assessed by the Nutritional Risk Score (NRS) on the outcomes of in-patients with pulmonary tuberculosis (PTB).

DESIGN

All hospitalised patients with microbiologically confirmed PTB were enrolled. A four-point NRS included low body mass index (<18.5 kg/m(2)), hypoalbuminaemia (<30.0 g/l), hypocholesterolaemia (<2.33 mmol/l) and severe lymphocytopaenia (<7 x 10(5) cells/l). The primary outcome was overall in-hospital mortality. The degree of radiographical resolution after anti-tuberculosis treatment was also evaluated.

RESULTS

In a total of 156 patients, the male to female ratio was 1.6:1. The overall mortality was 13.5% and tuberculosis-specific fatality was 3.9%. Predisposing factors and high NRS (> or = 3 points) were independent risk factors for in-hospital death after adjusting for the severity of PTB. High NRS (OR = 16.8, P < 0.001) and predisposing factors (OR = 5.4, P = 0.032) were independent risk factors for 30-day survival. The NRS was not associated with radiographic improvement.

CONCLUSION

Regardless of disease severity, the high NRS was a significant negative predictor among in-patients with PTB; this finding should therefore be considered in the management of PTB despite the current era of effective anti-tuberculosis chemotherapy.

Isolation and characterization of bacteriocin-producing bacteria from the gastrointestinal tract of broiler chickens for probiotic use

AIMS

To isolate and characterize the bacteriocin-producing bacteria (BPB) from the gastrointestinal tract of broiler chickens for probiotic use.

METHODS AND RESULTS

In total, 291 bacterial strains were isolated from broilers and screened for bacteriocin-producing ability. The bacteriocins produced by Enterococcus faecium SH 528, Ent. faecium SH 632 and Pediococcus pentosaceus SH 740 displayed inhibitory activity against pathogens including Clostridium perfringens and Listeria monocytogenes. Activity of the bacteriocins remained unchanged after 30 min of heat treatment at 60 degrees C or exposure to organic solvents, but diminished after treatment with proteolytic enzymes. PCR was used to detect the structural genes enterocin A and B in SH 528, enterocin L50 and P in SH 632, and pediocin PA-1 in SH 740. Most of them were resistant to 0.5% bile salts and remained viable after 2 h at pH 3.0. Ent. faecium SH 528 exhibited the highest amylase activity among the strains tested.

CONCLUSIONS

We selected Ent. faecium SH 528 and SH 632 and Ped. pentosaceus SH 740 by probiotic selection criteria including inhibition activity against pathogens.

SIGNIFICANCE AND IMPACT OF THE STUDY

The isolated BPB could potentially be used in the poultry industry as probiotics to control pathogens.

Studies on red cell carbonic anhydrase types in Korean cattle

Red cell carbonic anhydrase types in Korean cattle were investigated by means of starch gel electrophoresis. A carbonic anhydrase zone (X) located ahead zone F was found in 12 out of 502 Korean cattle. The distribution of CA phenotypes in 490 Korean cattle was CA FS type 92 and CA SS type 398. The CA FF type has not yet been recognized in Korean cattle. The gene frequencies were CAF = 0.094 and CAS = 0.906. No statistically significant differences were observed between gene frequencies in cattle from six different Korea provinces.

Studies on hemoglobin variants in Korean cattle

814 hemoglobin samples from Korean cattle were investigated by starch gel electrophoresis for the detection of hemoglobin variants. A new variant of cattle hemoglobin, called Hb, H, was recognized. It has a slower rate of migration than Hb A. Hemoglobin types from 814 Korean cattle were as follows: 652 of Hb AA type (80.1%), 133 of Hb AB (16.4%), 12 of Hb AC (1.5%), 9 of Hb BB (1.1%), 2 of Hb BC (0.2%), 4 of Hb AH (O.5%), 1 of Hb CH (0.1%), 1 of Hb HH (O.1%). These figures correspond to the frequencies: HbA = 0.893, HbB = 0.093, HbC = 0.009, HbH = 0.004.

Is the foot elevation the optimal position for wound healing of a diabetic foot?

In managing diabetic foot ulcers, foot elevation has generally been recommended to reduce oedema and prevent other sequential problems. However, foot elevation may decrease tissue oxygenation of the foot more than the dependent position since the dependent position is known to increase blood flow within the arterial system. In addition, diabetic foot ulcers, which have peripheral vascular insufficiency, generally have less oedema than other wounds. Therefore, we argue that foot elevation may not be helpful for healing of vascularly compromised diabetic foot ulcers since adequate tissue oxygenation is an essential factor in diabetic wound healing. The purpose of this study was to evaluate the influence of foot height on tissue oxygenation and to determine the optimal foot position to accelerate wound healing of diabetic foot ulcers. This study included 122 cases (73 males and 47 females; two males had bilateral disease) of diabetic foot ulcer patients aged 40-93 years. Trans-cutaneous partial oxygen tension (TcpO(2)) values of diabetic feet were measured before and after foot elevation (n=21). Elevation was achieved by placing a foot over four cushions. We also measured foot TcpO(2) values before and after lowering the feet (n=122). Feet were lowered to the patient's tibial height, approximately 30-35 cm, beside a bed handrail. Due to the large number of lowering measurements, we divided them into five sub-groups according to initial TcpO(2.) Tissue oxygenation values were compared. Foot-elevation-lowered TcpO(2) values before and after elevation were 32.5+/-22.2 and 23.8+/-23.1 mmHg (p<0.01), respectively. Foot-lowering-augmented TcpO(2) values before and after lowering were 44.6+/-23.8 and 58.0+/-25.9 mmHg (p<0.01), respectively. The lower the initial TcpO(2) level, the more the TcpO(2) level increased. The foot lowering, rather than elevation, significantly augments TcpO(2) and may stimulate healing of diabetic foot ulcers.

Decreased phosphorylation of STAT-1, STAT-4 and cytokine release in MDR-TB patients with primary resistance

SETTING

We recently showed that treatment failure rate was higher among multidrug-resistant tuberculosis (MDR-TB) patients without a previous history of tuberculosis (TB) treatment, or so-called 'primary resistance'.

OBJECTIVE

To investigate the phosphorylation levels of signal transducers and activators of transcription-1 (STAT-1) and STAT-4 and the subsequent cytokine release as a possible cause of a poor prognosis in MDR-TB patients with primary resistance.

DESIGN

Ten patients with successfully treated pulmonary TB without resistance, 12 MDR-TB patients with acquired resistance and 10 MDR-TB patients with primary resistance were enrolled. After 24 h stimulation of peripheral blood mononuclear cells (PBMC) with interferon-gamma (IFN-gamma), interleukin-12 (IL-12), purified protein derivative (PPD), or lysate of Mycobacterium tuberculosis, flow cytometric analysis of intracellular pSTAT-1 and pSTAT-4 were performed and secretion of IFN-gamma, IL-12p40 and tumour necrosis factor-alpha (TNF-alpha) was measured in culture supernatant.

RESULTS

The mean fluorescent intensities of pSTAT-1 and pSTAT-4 in PBMC of MDR-TB patients with primary resistance decreased on stimulation of IFN-gamma, PPD or lysate of M. tuberculosis when compared with patients with acquired resistance. In addition, secretion of IFN-gamma, IL-12p40 and TNF-alpha in these patients decreased on various stimuli.

CONCLUSION

Decreased phosphorylation of STAT-1, STAT-4, and of subsequent cytokine release, might be associated with a poor prognosis in MDR-TB patients with primary resistance.

Isolation and partial characterization of a bacteriocin produced by Pediococcus pentosaceus K23-2 isolated from Kimchi

AIMS

Screening and partial characterization of a bacteriocin produced by Pediococcus pentosaceus K23-2 isolated from Kimchi, a traditional Korean fermented vegetable.

METHODS AND RESULTS

A total of 1000 lactic acid bacteria were isolated from various Kimchi samples and screened for the production of bacteriocin. Pediocin K23-2, a bacteriocin produced by the Pediococcus pentosaceus K23-2 strain, showed strong inhibitory activity against Listeria monocytogenes. The bacteriocin activity remained unchanged after 15 min of heat treatment at 121 degrees C or exposure to organic solvents; however, it diminished after treatment with proteolytic enzymes. The bacteriocin was maximally produced at 37 degrees C, when the pH of the culture broth was maintained at 5.0 during the fermentation, although the optimum pH for growth was 7.0. The molecular weight of the bacteriocin was about 5 kDa according to a tricine SDS-PAGE analysis.

CONCLUSIONS

Pediococcus pentosaceus K23-2 isolated from Kimchi produces a bacteriocin, which shares similar characteristics to the Class IIa bacteriocins. The bacteriocin is heat stable and shows wide antimicrobial activity against Gram-positive bacteria, especially L. monocytogenes.

SIGNIFICANCE AND IMPACT OF THE STUDY

Pediocin K23-2 and pediocin K23-2-producing P. pentosaceus K23-2 could potentially be used in the food and feed industries as natural biopreservatives, and for probiotic application to humans or livestock.

Nutritional deficit as a negative prognostic factor in patients with miliary tuberculosis

The effects of malnutrition on outcomes in miliary tuberculosis (MTB) are not well described. The aim of the present study was to find predictors for the development of acute respiratory failure (ARF) and survival in MTB patients, focusing on parameters reflecting nutritional condition. Out of the patients from three hospitals who had microbiologically or histopathologically confirmed tuberculosis, 56 patients presenting with typical disseminated pulmonary nodules on radiographs were retrospectively enrolled. A four-point nutritional risk score (NRS) was defined according to the presence of four nutritional factors: low body mass index (BMI; <18.5 kg x m(-2)), hypoalbuminaemia (<30.0 g x L(-1)), hypocholesterolaemia (<2.33 mmol x L(-1)) and severe lymphocytopenia (<7 x 10(5) cells x L(-1)). The male to female ratio was 1:3. ARF developed in 25% of patients (14 out of 56), with a 50% fatality rate. A high NRS (> or =3 points) was an independent risk factor for the development of ARF and fatality. In 90-day survival analysis, ARF, severe lymphocytopenia, hypocholesterolaemia, low BMI and higher NRS were risk factors for poor outcome. In multivariate analysis, only high NRS was an independent risk factor for 90-day survival rate in patients with MTB. A high nutritional risk score was a good predictor of poor outcome in miliary tuberculosis patients. Additional approaches to recover the nutritional deficits may become a focus in future management of miliary tuberculosis.