Effects of nurse managers' inclusive leadership on nurses' psychological safety and innovative work behavior: The moderating role of collectivism

INTRODUCTION

In the rapidly evolving healthcare landscape, the capacity to foster innovative work behavior among nurses is increasingly important. This study examined the dynamics between inclusive leadership, psychological safety, collectivism, and innovative work behavior among nurses.

DESIGN

The study used a cross-sectional, correlational design.

METHODS

This study utilized data from 730 medical-surgical nurses who provided direct care to patients. Standardized instruments were used to assess key study variables. Statistical analyses, including moderated mediation regressions, were employed to investigate the complex interplay among these variables.

RESULTS

We found a positive association between inclusive leadership and innovative work behavior, and psychological safety mediated this relationship. Collectivism moderated inclusive leadership's direct relationship with psychological safety and its indirect relationship with innovative work behavior. The results revealed that nurses with lower levels of collectivism were more responsive to their managers' inclusive behaviors, strengthening the relation between inclusive leadership, psychological safety, and innovative work behavior.

CONCLUSION

Our findings suggest that promoting inclusive leadership behaviors among nurse managers to create a psychologically safe environment can motivate nurses to engage in innovative work behavior. However, it is also important to understand that the effectiveness of leadership may differ depending on the collectivist values of individual nurses.

CLINICAL RELEVANCE

Nurse managers should adopt inclusive leadership behaviors, such as valuing trust, open communication, and diversity, in order to foster psychological safety and innovative work behavior among nurses.

Comparison of Chemical Composition, Quality, and Muscle Fiber Characteristics between Cull Sows and Commercial Pigs: The Relationship between Pork Quality Based on Muscle Fiber Characteristics

This study aims to compare the chemical composition, quality, and muscle fiber characteristics of cull sows and commercial pigs, investigating the effect of changes in muscle fiber characteristics on pork quality. The proximate composition, color, pH, water-holding capacity (drip loss and cooking loss), protein solubility, total collagen content, and muscle fiber characteristics of cull sows (n=20) and commercial pigs (n=20) pork were compared. No significant differences were found between cull sows and commercial pigs in terms of proximate composition, drip loss, protein solubility, or total collagen content of their meat (p<0.05). However, cull sow pork exhibited a red color and a higher pH (p<0.05). This appears to be the result of changes in muscle fiber number and area composition (p<0.05). Cull sow meat also displayed better water-holding capacity as evident in a smaller cooking loss (p<0.05), which may be related to an increase in muscle fiber cross-sectional area (p<0.05). In conclusion, muscle fiber composition influences the pork quality; cull sow pork retains more moisture when cooked, resulting in minimal physical loss during processing and can offer more processing suitability.

Comparing Physicochemical Properties, Fatty Acid Profiles, Amino Acid Composition, and Volatile Compounds in Dry-Cured Loin: The Impact of Different Levels of Proteolysis and Lipid Oxidation

The aim of this study is to compare the quality characteristics of dry-cured loins with different levels of proteolysis and lipid oxidation and to investigate the relationship between these factors on quality characteristics. The dry-cured loins were divided into four groups [proteolytic index (PI) and 2-thiobarbituric acid reactive substances (TBARS) of high levels (HH), PI of high level and TBARS of low level (HL), PI of low level and TBARS of high level (LH), and PI and TBARS of low levels (LL)] based on the proteolysis index and TBARS. Moisture, protein, and fat content were all significantly influenced by proteolysis and lipid oxidation (p<0.05). The total fatty acid content in the high proteolysis groups (HH and HL) was significantly lower than that in the low proteolysis groups (LH and LL; p<0.05). For total free amino acid content, HH was the highest, and LL was the lowest (p<0.05). On the other hand, there was no significant difference between HL and LH (p>0.05). In the amount of total volatile compounds, there was no significant difference between HH and HL (p>0.05), but LH and LL significantly differed (p<0.05). In conclusion, proteolysis and lipid oxidation can influence the quality characteristics of dry-cured loin. Additionally, proteolysis might be as influential in generating volatile compounds as lipid oxidation.

Paprika extract as a natural antioxidant in cold-stored pork patties: Effect on oxidative stability and heterocyclic amines inhibition

In this study, we compared the degree of oxidation of pork patties refrigerated at 7 °C for 0, 7, and 14 days and the content of 10 types of heterocyclic amines (HCAs) after heating. The pork patties used in the study were added with 0.7 mg sodium nitrite (SN) and 5 mg paprika extract (PE), respectively. IQx (2-Amino-3-methyl-imidazo[4,5-f]-quinoxaline), MeIQx (2-Amino-3, 8-dimethyl-imidazo[4,5-f]-quinoxaline), PhIP (2-Amino-1-methyl-6-phenyl-imidazo[4,5-b]-pyridine), and Harman (1-Methyl-9H-pyrido[4,3-b]-indole) contents increased with increasing storage periods of treatment. On the other hand, HCAs production in SN and PE treatments were suppressed over the storage period, with IQ (2-Amino-3-methyl-imidazo[4,5-f]-quinoline) and Aαc (2-Amino-9H-dipyrido[2,3-b]-indole) being suppressed significantly (P < 0.05). The control's pH, cooking loss, lipid, and protein oxidation were higher than SN and PE-treated patties at 14 d (P < 0.05). These differences affect the formation of HCAs. PLS-DA showed a strong correlation between protein oxidation and IQx, Harman, 4,8-DiMelQx (2-Amino-3, 4, 8-trimethyl-imidazo[4,5-f]-quinoxaline), PhIP, and MeIQx, while lipid oxidation correlated with IQx, Harman, and PhIP. Both SN and PE showed HCAs inhibitory activity and exhibited oxidative stability during storage.

Comparison between Berkshire and crossbreed on meat quality, and investigation of the relationship with fatty acid composition and meat quality

This study aimed to compare meat quality traits between Berkshire and crossbreed (Landrace × Yorkshire × Duroc), and to investigate the relationship between meat quality traits and fatty acid composition. 20 Berkshire and 20 crossbreed pigs were used to compare pork loin quality and to determine the relationship between measured variables. 23 variables were measured including proximate composition, pH, drip loss and cooking loss, Warner-Bratzler shear force, and fatty acid composition. Berkshire had higher moisture content, pH, water-holding capacity, saturated fatty acids, and redness than the crossbreed pig (p < 0.05). The fat content and polyunsaturated fatty acid were low (p < 0.05) in Berkshire. Correlation analysis showed a negatively correlation between moisture and fat content, and a positively correlation between saturated fatty acid and fat content. Moreover, saturated fatty acid and polyunsaturated fatty acid were negatively correlated. As a result of factor analysis and partial least square regression, saturated fatty acid and polyunsaturated fatty acid were estimated to be the main factors affecting quality characteristics of pork. Pig breed is associated with differences in meat quality, and fatty acid composition can have an effect on meat quality parameters.

Inhibitory and antioxidative capacity of nutmeg extracts on reduction of lipid oxidation and heterocyclic amines in pan-roasted beef patties

Identification and inhibition of mutagenic and carcinogenic heterocyclic amines (HCAs) from pan-roasted beef patties were performed by adding (0.02%) tertiary butyl hydroquinone (TBHQ) and (0.05%) ethanol-extracted nutmeg (ENE) using HPLC and principal component analysis. Ten HCAs, including six polar and four non-polar, were assessed. The addition of (0.05%) ENE significantly (P < 0.05) reduced the cooking loss and shrinkage of patties during cooking and reduced the total formation HCAs by 73.97%, which proved the significant (P < 0.05) inhibitory effect as a natural antioxidant against lipid oxidation and HCA formation compared to TBHQ. The DPPH radical-scavenging activity, total phenolic content, and available active metabolites of ENE were estimated. Furthermore, a positive correlation was observed between pH, level of thiobarbituric acid reactive substances, and HCA formation in both the groups. TBHQ and ENE were significant HCAs inhibitors (P < 0.001), but ENE showed resilient oxidative stability during refrigeration storage. Therefore, ENE can be used to reduce HCAs formation in pan-roasted beef patties.

Effect of early hysterectomy on a risk of incident cardiovascular disease in women: a nationwide population-based cohort study

Aim

Women who inevitably underwent surgical hysterectomy before natural menopause may have an earlier increase in hematocrit and storage iron than women who continue menstruation, thereby increasing the risk of cardiovascular disease (CVD) early. We aimed to evaluate the association of women with hysterectomy vs. without hysterectomy before their 50s with the risk of incident CVD.

Methods

This was a retrospective-cohort study, 135,575 women aged 40 to 50 years in 2011–2014 were extracted from the Korean Health Insurance Review and Assessment Service data and after propensity score matching, 55,539 pairs were included in hysterectomy and non-hysterectomy group respectively. The primary endpoint was major adverse cardiac and cerebrovascular events (MACCE), a composite of cardiovascular death, myocardial infarction (MI), stroke, and coronary artery revascularization.

Results

After adjustment for confounding factors, hysterectomy group had an increased risk of MACCE compared with non-hysterectomy group (hazard ratio [HR], 1.25; 95% confidence interval [CI], 1.09–1.44). Regarding individual outcomes, cardiovascular death, MI, and coronary revascularization were comparable between the groups, whereas, the risk of stroke was significantly higher in hysterectomy group than non-hysterectomy group (HR, 1.31; 95% CI, 1.12–1.53). Even after excluding women who underwent oophorectomy, hysterectomy group had a higher risk of MACCE than non-hysterectomy group (HR, 1.24; 95% CI 1.06–1.44).

Conclusions

Early surgical menopause due to hysterectomy, not hormonal menopause, was associated with an increased risk for a composite of CVD, especially stroke. This suggest that the role of “uterus” as well as sex hormones may be important for the sharp increase in the risk of CVD in women after menopause.

Funding Acknowledgement

Type of funding sources: None.

Optimal strategy for antiplatelet therapy after endovascular revascularization in patients with lower extremity artery disease

Background

The duration of antiplatelet therapy after endovascular revascularization in patients with lower extremity artery disease (LEAD) has not been well established. This study aimed to evaluate the clinical outcome according to the duration of dual antiplatelet therapy (DAPT) in real practice.

Methods

From April 2009 to June 2019, 376 patients with LEAD underwent successful endovascular revascularization. After the procedure, the received single antiplatelet therapy (SAPT) or DAPT of various durations were classified into two groups (SAPT or DAPT &lt;6 months vs. DAPT ≥6 months). The primary outcomes were major adverse cardiovascular events (MACEs) and major adverse limb events (MALEs). The safety outcome was moderate-to-severe bleeding according to the Global Use of Strategies to Open Occluded Arteries (GUSTO) criteria.

Results

Over the 40-month follow-up period, MACE occurred less frequently in the DAPT ≥6 months group than that in the SAPT or DAPT &lt;6 months group (12.4% vs. 23.8%; hazard ratio [HR]: 0.56; 95% confidence interval [CI]: 0.35–0.89; p=0.014) after inverse probability-weighted adjustment and propensity-score matching analysis (HR: 0.55, 95% CI; 0.30–0.99, p=0.048). The incidence of MALE did not show significant difference between the two groups (DAPT ≥6 months group: 17.1% vs. SAPT or DAPT &lt;6 months group: 13.1%; HR: 1.05; 95% CI: 0.62–1.78; p=0.846). A significant difference between the DAPT ≥6 months group and the SAPT or DAPT &lt;6 months group was not observed regarding the incidence of moderate-to-severe GUSTO bleeding.

Conclusions

In patients with LEAD, DAPT for ≥6 months after endovascular revascularization was associated with a lower incidence of MACE.

Funding Acknowledgement

Type of funding sources: Public Institution(s). Main funding source(s): National Research Foundation of Korea (NRF) grant funded by the government of Korea (MSIT) (No. 2019R1G1A1100442).

The impact of statin treatment intensity after endovascular revascularization for lower extremity peripheral artery disease

Purpose

There are few Asian studies on the clinical impact of statin intensity on clinical outcomes in patients with peripheral artery disease (PAD). This study investigated the clinical impact of statin intensity in patients with PAD after endovascular revascularization.

Material and methods

From April 2009 to June 2019, 376 patients with lower extremity PAD treated with endovascular revascularization were enrolled. They were classified into three groups according to statin intensity: no-statin, low-to-moderate intensity (LMI), and high-intensity (HI) groups. The primary outcomes were major adverse cardiovascular events (MACE) and major adverse limb events (MALE).

Results

During the 40-month follow-up, MACE occurred less in the HI and LMI groups than the no-statin group (11.4% vs. 16.0% vs. 39%, p&lt;0.001). In the adjusted Cox models, the HI group had the lowest MACE (hazard ratio [HR]: 0.347; 95% confidence interval [CI] 0.144–0.834; p=0.018) and MALE (HR: 0.344; 95% CI 0.120–0.989, p=0.048), while the LMI group had fewer MACE (HR: 0.319; 95% CI 0.169–0.604, p=0.048) than the no-statin group. HI therapy was associated with better outcomes in terms of MALE (HR: 0.377; 95% CI: 0.208–0.684; p=0.001) and repeat revascularization (HR: 0.449; 95% CI: 0.243–0.830; p=0.011) than the LMI group after the inverse probability treatment weighting analysis.

Conclusions

HI and LMI statin use is associated with a significant reduction of MACE than no statin use. Regarding MALE, HI statin use was associated with better outcomes than no statin or LMI statin use.

Funding Acknowledgement

Type of funding sources: Public Institution(s). Main funding source(s): National Research Foundation of Korea (NRF) grant funded by the Korea government (MSIT) (No. 2019R1G1A1100442).

Changes in Quality Traits and Oxidation Stability of Syzygium aromaticum Extract-Added Cooked Ground Beef during Frozen Storage

This study was accomplished by comparing the oxidative stability of (0.1%) Syzygium aromaticum extract (SAE) and (0.02%) butylated hydroxytoluene (BHT)-added cooked ground beef with an antioxidant free-control sample during frozen storage. All samples showed a non-significant (p > 0.05) effect on pH, thawing loss, redness, and yellowness values during storage. Incorporation of BHT and SAE led to a significant (p < 0.05) reduction in thiobarbituric acid-reactive substances (TBARS) and volatile levels as an active antioxidant. The generation of less volatiles found in SAE-treated samples up to 6 months (p < 0.05) of storage. Therefore, SAE-protected ground beef can lead to lower lightness, lipid oxidation, and volatile compounds levels after cooking compared with control and BHT samples.

Effect of Pig Breed and Processing Stage on the Physicochemical Properties of Dry-Cured Loin

This study investigated the effect of pig breeds on the quality characteristics of dry-cured loins according to the processing stage. Physicochemical properties of 20 dry-cured processed loins with the different pig breeds [Berkshire vs Landrace×Yorkshire× Duroc (LYD; n=10)] and different processing stages (raw, curing, dry-ripened 15 day and 30 day) were analyzed. The pig breed influenced moisture content and pH with values of 59% and 53%, and 6.17 and 5.94, for Berkshire and LYD, respectively, on day 30. Dry-cured loins made with Berkshire showed higher hardness and lower cohesiveness than that of the LYD (p<0.05). Redness and yellowness were higher for Berkshire than LYD (p<0.05). Lipid oxidation and lightness did not affect by pig breed during processing stages (p>0.05). However, sulfhydryl content was significantly higher in Berkshire compared to the LYD after dry-ripened for 15 days (p<0.05). The concentration of total free amino acids and fatty acids was higher for Berkshire during all processing stages (p<0.05). Berkshire may be better quality due to its high moisture content and pH compared to the LYD.

Arginine supplementation may improve color and redox stability of beef loins through delayed onset of mitochondrial-mediated apoptotic processes

The objective of this study was to evaluate the effects of arginine (ARG) and/or lysine (LYS) supplementation on meat quality and oxidative stability of beef loins. Steers (n = 40) were split among four dietary treatments (control, ARG, LYS or ARGLYS). The loins (longissimus lumborum) were obtained at 1 day postmortem and aged either 14 or 28 days prior to cutting of steaks for 7 days of display. No impacts of diet treatments on instrumental tenderness, water-holding capacity and fatty acid profiles were found (P > 0.05). Extended aging significantly decreased lipid oxidative stability, color stability and reducing ability of loins. However, steaks from ARG and ARGLYS maintained superior color stability coupled with lower mitochondrial membrane permeability and higher cytochrome c redox stability compared to control (P < 0.05). These results indicate that ARG supplementation can improve color stability of beef loins possibly through delayed onset of mitochondrial-mediated apoptotic processes.

Assessment of the Stability of Fresh Beef Patties with the Addition of Clove Extract during Frozen Storage

The study assessed the stability for fresh beef patties with the inclusion of clove extract (CE) as a natural antioxidant in comparison to butylated hydroxytoluene (BHT) and ascorbic acid (AA) at frozen storage. Four different patties were made dependent on the added antioxidants: control (added no antioxidants), added with 0.02% BHT, 0.05% AA, and 0.1% CE. Inclusion of BHT, AA, and CE resulted in a significant reduction of thiobarbituric acid reactive substances (TBARS) and hue angle (h°) value and increase of redness (CIE a*) and chroma (C*) values (p<0.05). BHT, AA, and CE were observed effectively to retard lipid oxidation and increase color stability. BHT and AA revealed significantly (p<0.05) higher thiol content than the control and CE. However, the reduction percentage for thiol content in CE treated patties was lower than the control and AA-treated patties from first to last time of storage. Moreover, inclusion of AA and CE led to significantly (p<0.05) increased heme iron content when compared to BHT and the control. In conclusion, CE can replace the application of AA and BHT while improving lipid stability, heme iron content, and color stableness of fresh beef patties throughout frozen storage.

Combined impacts of initial freezing rate of pork leg muscles (M. biceps femoris and M. semitendinosus) and subsequent freezing on quality characteristics of pork patties

The objective of this study was to determine the combined impacts of initial sub-primal freezing with subsequent freezing of manufactured pork patties on quality attributes and oxidative stability. Patties were manufactured (n = 3 batches) from pork leg muscles (M. biceps femoris and M. semitendinosus) frozen at different methods including still-air freezing (SAF), blast freezing (BF), and cryogenic freezing (CF). Then, patties were subjected to additional freezing treatments. Frozen/thawed patties exhibited increased cooking loss, springiness, and chewiness, lipid and protein oxidation, and decreased protein solubility compared to unfrozen counterparts (P < .05). However, patties from CF legs maintained similar protein solubility and lipid/protein oxidation compared to unfrozen controls (P > .05), while significantly minimizing sub-primal thawing loss and oxidation compared to patties from SAF. The results of the present study suggest the importance of initial freezing rate of sub-primals with subsequent freezing on quality characteristics of frozen/thawed meat patties.

Effects on quality properties of cooked pork sausages with Caesalpinia sappan L. extract during cold storage

This study was evaluated the possibility of replacing some chemical additives in meat products by the Caesalpinia sappan L. (CS) extract. Four different types of cooked pork sausages were prepared by mixing nitrite with CS extracts at different concentration like control (without nitrite and extract), T1 (0.007% nitrite), T2 (0.004% nitrite + 0.05% extract) and T3 (0.1% extract). Physicochemical properties, sensory attributes, and antioxidant activity of the control and treatments were investigated. Ash contents and DPPH radical scavenging activity were significantly (P < 0.05) higher when pork sausages were processed with the addition of CS extracts. The rate of lipid oxidation significantly (P < 0.05) decreased in the case of CS extracts addition. By comparing with the control, all nitrite or CS extract resulted in significant (P < 0.05) lower L* values; however, 0.007% nitrite and 0.004% nitrite plus 0.05% CS extract pointed significantly (P < 0.05) higher a* values in all storage times. As well as, arrangement of CS extracts (0.05%) and nitrite (0.004%) in pork sausages displayed high gumminess and cohesiveness values (P < 0.05), stable springiness and chewiness, and significantly (P < 0.05) enhance overall acceptability scores as sensory attributes compared to the control sausage after 30 days of storage. Therefore, the CS extract (0.05%), which can act as a natural antioxidant, exert a positive effect with nitrite (0.004%) on the sensory acceptability and help to preserve the desired color of cooked pork sausages by reducing oxidation rate during cold storage.

Comparison of Butylated Hydroxytoluene, Ascorbic Acid, and Clove Extract as Antioxidants in Fresh Beef Patties at Refrigerated Storage

This study was performed to assess the comparison of the effects amongst butylated hydroxytoluene (BHT), clove extract (CE), and ascorbic acid (AA) as antioxidants on the oxidative stability and color values in fresh beef patties. The adding of BHT, AA, and CE to patties significantly restrained lipid oxidation, lowered hue angle as color value, and expanded redness and chroma values of fresh beef patties in comparison to the control (p<0.05). BHT and AA significantly led to impede the protein oxidation of patties by lowering carbonyl content (p<0.05). CE had no negative effect on protein oxidation. The antioxidant effects of BHT, AA, and CE were obviously manifested. Nonetheless, BHT, AA, and CE appeared to have insignificant difference of each other for lowering the protein oxidation at the end of storage. BHT and CE represented lowered lipid oxidation in comparison to AA. The antioxidant effects of BHT, AA, and CE on lipid oxidation were more marked than the effects on protein oxidation. Furthermore, CE as a natural antioxidant evinced the efficiency in oxidative stability and color stability in fresh beef patties. The study implied that CE could substitute the use of BHT and AA when making beef patties during storage.

The Effects of Natural Antioxidants on Protein Oxidation, Lipid Oxidation, Color, and Sensory Attributes of Beef Patties during Cold Storage at 4℃

This study aimed to investigate the use of golden thread extract (GTE), clove extract (CE), and commercially available nitrite for retarding lipid and protein oxidation and for maintaining color stability and sensory attributes in beef patties stored at 4℃. GTE, CE, and nitrite treatment samples were found to be efficient in retarding lipid oxidation as all three treatments resulted in low thiobarbituric acid reactive substance (TBARS) content (p<0.05). By using GTE, CE, and nitrite into beef patties, protein oxidation was not developed. Incorporation of GTE and CE into beef patties maintained color stability by protecting against the decrease of L*, a*, b*, chroma, and hue angle values and exhibited significant influence on sensory characteristics, including color and odor of beef patties (p<0.05). Compared to commercially available nitrite, GTE and CE were more effective as antioxidants for inhibiting lipid oxidation, and preserving color stability of fresh beef patties. The study indicated that GTE and CE could be utilized efficiently to extend the shelf life of beef patties.

The Quality Improvement of Emulsion-type Pork Sausages Formulated by Substituting Pork Back fat with Rice Bran Oil

The effects of pork back fat (PBF) substitution with various concentrations of rice bran oil (RBO) (50%, 45%, 40% and 35%) on the physicochemical characteristics and sensory attributes of emulsion-type pork sausages were studied. The modified pork sausages were compared with control sausages produced using PBF only. The sausages with RBO had significantly lower (p<0.05) moisture content than the control sausages. Sausages made from PBF substituted with 40% RBO showed the lowest cooking loss. Substitution of PBF with RBO had no significant effect on the emulsion stability of pork sausages. All sausages with RBO showed significantly lower (p<0.05) hardness values than control sausages. Sausages with RBO also had significantly higher values (p<0.05) of unsaturated fatty acid and polyunsaturated to saturated fatty acid contents than the controls. RBO substitution had no effect on the flavor intensity of sausages, but it improved the tenderness and produced a softer texture.

Breast Meat Quality and Protein Functionality of Broilers with Different Probiotic Levels and Cyclic Heat Challenge Exposure

This study was performed to evaluate the effect of probiotic feeding level on meat quality and protein functionality of breast muscle from chickens exposed to cyclic heat challenge. A total of 180 one-d-old male chicks were randomly allocated in 36 floor pens. From Day 15, the birds were exposed to 32°C for 10 h daily until the end of the experiment (Day 46). Three dietary treatments containing different levels of probiotic (a mixture of 4 lactic acid bacteria, 5.0 × 109 cfu/g) were prepared; regular diet without probiotic (control), regular diet with 0.5 g of probiotic/kg feed (probiotic 0.5) and regular diet with 1.0 g of probiotic/kg feed (probiotic 1). Both breast muscles (M. pectoralis major) were collected at 24 h postmortem, and the same side breast muscle was assigned to each experiment 1 (meat quality analysis, n = 6) and 2 (protein functionality analysis, n = 3). Probiotic feeding level did not affect initial pH and temperature declines (P > 0.05) of breast muscle until 6 h postmortem. However, the breast muscles from probiotic 1 group (5.92) showed a significantly higher ultimate pH than those from control (5.78) or probiotic 0.5 (5.82) groups at 24 h postmortem. No differences in chemical composition (moisture, protein, fat, ash, and phospholipids), water-holding capacity (cooking loss and display weight loss), shear force, and lipid oxidation stability were found in breast muscles from chickens exposed to cyclic heat challenge, regardless of probiotic levels (P > 0.05). An increase in probiotic level increased total protein solubility (P = 0.0004) and emulsion activity index of sarcoplasmic protein (P = 0.0032) of ground chicken breast. The results from the current study suggest that the supplementation of this commercial probiotic product could partially improve protein functionality of breast muscles from chickens exposed to cyclic heat challenge, in a dose-dependent manner within the applied level.

Properties of Frankfurter-type Sausages with Pork Back-fat Replaced with Bovine Heart Surimi-like Materials

This study investigates the effect of bovine heart surimi-like material (BHSM) used as a back fat replacer, on the physicochemical and sensory characteristics of frankfurter-type sausages. Frankfurter-type sausage with added BHSM had a higher moisture content and lower fat content than the control. In addition, the samples with added BHSM had higher pH, cooking loss and 2-thiobarbituric acid-reactive substance (TBARS) value and lower water exudation than the control. The sausage formulation with 40% BHSM was more effective in delaying lipid oxidation without affecting cooking loss compared to the 60% BHSM treatment sample. Results showed that hardness values increased upon replacement with BHSM, and sausages manufactured with 40% BHSM had higher lightness and lower redness values. Panelists found there were no differences in color, odor, and tenderness scores and the overall acceptability score found that treatment samples containing 20% and 40% BHSM were preferable to the control after storage for 14 d. These results indicate that fat replacement with BHSM was beneficial to the quality of frankfurter-type sausages, and acceptable reduced-fat products can be produced when back fat is replaced with up to 40% BHSM.

Effects of injection of hydrolysis plasma protein solution on the antioxidant properties in porcine M. Longissimus Lumborum

BACKGROUND

Plasma protein hydrolysates have been shown to possess antioxidant activity. However, no report has yet to examine the antioxidant effects of injection of plasma protein hydrolysates on meat quality. Therefore, in this study, the effects of injection of hydrolysis plasma protein solution on meat quality and storability were investigated in porcine M. longissimus lumborum.

METHODS

Twelve pigs were randomly selected at a commercial slaughter plant and harvested. Dissected loins were injected with one of five solutions: C- control (untreated), T1- 10 mM phosphate buffer solution (PBS), T2- 10 mM PBS with 0.01 % butylated hydroxytoluene, T3- 10 mM PBS with 5 % plasma proteins, and T4- 10 mM PBS with 5 % hydrolysis plasma proteins.

RESULTS

T3 and T4 induced greater reduction in protein content of the loin muscle than other treatments. T2 resulted in the lowest pH as well as highest cooking loss. After a storage period of 3-7 days, both lightness and redness of meat were unaffected by all injection treatments. However, yellowness was significantly elevated by treatment with T4 relative to the control. T4 also resulted in the lowest shear force (a measure of meat toughness), suggesting improvement of texture or tenderness. Further, T4 resulted in the most stable TBARS values during storage, indicating that this treatment might retard rancidity in meat.

CONCLUSION

Injection of porcine M. longissimus lumborum with hydrolysis plasma protein solution could improve overall pork quality, including tenderness and storability.

Supplementation of Pork Patties with Bovine Plasma Protein Hydrolysates Augments Antioxidant Properties and Improves Quality

This study investigated the effects of bovine plasma protein (PP) hydrolysates on the antioxidant and quality properties of pork patties during storage. Pork patties were divided into 4 groups: without butylated hydroxytoluene (BHT) and PP hydrolysates (control), 0.02% BHT (T1), 1% PP hydrolysates (T2), and 2% PP hydrolysates (T3). Pork patty supplemented with PP hydrolysates had higher pH values and lower weight loss during cooking than the control patties. Results showed that lightness and hardness both decreased upon the addition of PP hydrolysates. All samples containing BHT and PP hydrolysates had reduced TBARS and peroxide values during storage. In particular, 2% PP hydrolysates were more effective in delaying lipid oxidation than were the other treatments. It was concluded that treatment with 2% PP hydrolysates can enhance the acceptance of pork patty.

Detection of admittivity anomaly on high-contrast heterogeneous backgrounds using frequency difference EIT

This paper describes a multiple background subtraction method in frequency difference electrical impedance tomography (fdEIT) to detect an admittivity anomaly from a high-contrast background conductivity distribution. The proposed method expands the use of the conventional weighted frequency difference EIT method, which has been used limitedly to detect admittivity anomalies in a roughly homogeneous background. The proposed method can be viewed as multiple weighted difference imaging in fdEIT. Although the spatial resolutions of the output images by fdEIT are very low due to the inherent ill-posedness, numerical simulations and phantom experiments of the proposed method demonstrate its feasibility to detect anomalies. It has potential application in stroke detection in a head model, which is highly heterogeneous due to the skull.

Characterization of Cellulolytic and Xylanolytic Enzymes of Bacillus licheniformis JK7 Isolated from the Rumen of a Native Korean Goat

A facultative bacterium producing cellulolytic and hemicellulolytic enzymes was isolated from the rumen of a native Korean goat. The bacterium was identified as a Bacillus licheniformis on the basis of biochemical and morphological characteristics and 16S rDNA sequences, and has been designated Bacillus licheniformis JK7. Endoglucanase activities were higher than those of β-glucosidase and xylanase at all temperatures. Xylanase had the lowest activity among the three enzymes examined. The optimum temperature for the enzymes of Bacillus licheniformis JK7 was 70°C for endoglucanase (0.75 U/ml) and 50°C for β-glucosidase and xylanase (0.63 U/ml, 0.44 U/ml, respectively). All three enzymes were stable at a temperature range of 20 to 50°C. At 50°C, endoglucanse, β-glucosidase, and xylanase had 90.29, 94.80, and 88.69% residual activity, respectively. The optimal pH for the three enzymes was 5.0, at which their activity was 1.46, 1.10, and 1.08 U/ml, respectively. The activity of all three enzymes was stable in the pH range of 3.0 to 6.0. Endoglucanase activity was increased 113% by K⁺, while K⁺, Zn⁺, and tween 20 enhanced β-glucosidase activity. Xylanase showed considerable activity even in presence of selected chemical additives, with the exception of Mn²⁺ and Cu²⁺. The broad range of optimum temperatures (20 to 40°C) and the stability under acidic pH (4 to 6) suggest that the cellulolytic enzymes of Bacillus licheniformis JK7 may be good candidates for use in the biofuel industry.

Effects of synchronization of carbohydrate and protein supply in total mixed ration with korean rice wine residue on ruminal fermentation, nitrogen metabolism and microbial protein synthesis in holstein steers

Three Holstein steers in the growing phase, each with a ruminal cannula, were used to test the hypothesis that the synchronization of the hourly rate of carbohydrate and nitrogen (N) released in the rumen would increase the amount of retained nitrogen for growth and thus improve the efficiency of microbial protein synthesis (EMPS). In Experiment 1, in situ degradability coefficients of carbohydrate and N in feeds including Korean rice wine residue (RWR) were determined. In Experiment 2, three total mixed ration (TMR) diets having different rates of carbohydrate and N release in the rumen were formulated using the in situ degradability of the feeds. All diets were made to contain similar contents of crude protein (CP) and neutral detergent fiber (NDF) but varied in their hourly pattern of nutrient release. The synchrony index of the three TMRs was 0.51 (LS), 0.77 (MS) and 0.95 (HS), respectively. The diets were fed at a restricted level (2% of the animal’s body weight) in a 3×3 Latin-square design. Synchronizing the hourly supply of energy and N in the rumen did not significantly alter the digestibility of dry matter, organic matter, crude protein, NDF or acid detergent fiber (ADF) (p>0.05). The ruminal NH₃-N content of the LS group at three hours after feeding was significantly higher (p<0.05) than that of the other groups; however, the mean values of ruminal NH₃-N, pH and VFA concentration among the three groups were not significantly different (p>0.05). In addition, the purine derivative (PD) excretion in urine and microbial-N production (MN) among the three groups were not significantly different (p>0.05). In conclusion, synchronizing dietary energy and N supply to the rumen did not have a major effect on nutrient digestion or microbial protein synthesis (MPS) in Holstein steers.

Evidence of still-ongoing convergence evolution of the lactase persistence T-13910 alleles in humans

A single-nucleotide variant, C/T(-13910), located 14 kb upstream of the lactase gene (LCT), has been shown to be completely correlated with lactase persistence (LP) in northern Europeans. Here, we analyzed the background of the alleles carrying the critical variant in 1,611 DNA samples from 37 populations. Our data show that the T(-13910) variant is found on two different, highly divergent haplotype backgrounds in the global populations. The first is the most common LP haplotype (LP H98) present in all populations analyzed, whereas the others (LP H8-H12), which originate from the same ancestral allelic haplotype, are found in geographically restricted populations living west of the Urals and north of the Caucasus. The global distribution pattern of LP T(-13910) H98 supports the Caucasian origin of this allele. Age estimates based on different mathematical models show that the common LP T(-13910) H98 allele (approximately 5,000-12,000 years old) is relatively older than the other geographically restricted LP alleles (approximately 1,400-3,000 years old). Our data about global allelic haplotypes of the lactose-tolerance variant imply that the T(-13910) allele has been independently introduced more than once and that there is a still-ongoing process of convergent evolution of the LP alleles in humans.

Diffusion PDE-based denoising technique for magnetic resonance electrical impedance tomography

Recent progress in magnetic resonance electrical impedance tomography (MREIT) research has shown that conductivity images with higher spatial resolution and accuracy are achievable. One of the most important remaining problems to be solved in MREIT before we can apply the technique to human subjects is how to reduce the amount of injection current. Since we use an MRI scanner to measure the induced magnetic flux density data subject to an injection current, the data is contaminated with random noise. In order to obtain enough signal-to-noise ratio (SNR), we need to inject a large amount of current into the subject. However, it is obvious that we must comply with the electrical safety regulations and this means that we should deal with noisy data having a low SNR due to the limited amount of injection current. Furthermore, in the developed reconstruction algorithms, the required numerical differentiations of the noisy data may result in deterioration of the reconstructed conductivity image leading to a loss of important information. We propose a PDE-based denoising technique that diminishes the degradation of reconstructed conductivity images due to the noise in measured data. The proposed PDE-based technique is advantageous in reducing the random noise while preserving useful features in MREIT.

Conductivity images of biological tissue phantoms using a 3.0 tesla MREIT system

We present cross-sectional conductivity images of a biological tissue phantom obtained by using a 3.0 Tesla magnetic resonance electrical impedance tomography (MREIT) system. Inside the cylindrical phantom with 140 mm diameter and 140 mm height, biological tissues such as bovine tongue and liver, porcine muscle, and chicken breast were placed within an agar gelatin. Injecting current of 480 mA.ms into the tissue phantom, we measured the z-component B/sub z/ of the induced magnetic flux density B=(B/sub x/, B/sub y/, B/sub z/). Using the harmonic B/sub z/ algorithm, we reconstructed cross-sectional conductivity images from the measured B/sub z/ data. Reconstructed images clearly distinguish different tissues in terms of both their shapes and conductivity values.

MR imaging of the brain in Wilson disease of childhood: findings before and after treatment with clinical correlation

BACKGROUND AND PURPOSE

Although brain MR imaging findings in adult Wilson disease have been described in considerable detail, a paucity of information currently exists regarding brain MR imaging findings in pediatric Wilson disease. The purpose of this study was to analyze the brain MR imaging findings in Wilson disease of childhood at the initial stage and during follow-up after treatment and to correlate these observations with clinical response.

METHODS

We evaluated 50 patients with pediatric Wilson disease. Fifty initial and 20 follow-up MR images from 15 patients following penicillamine treatment were analyzed retrospectively, and the data were correlated with clinical findings.

RESULTS

Patients were categorized into 3 groups on the basis of initial MR imaging findings. Group I (n = 23) showed normal MR imaging findings. Group II (n = 15) was characterized by T1-weighted images with increased signal intensity in the globus pallidus (n = 15, 100%) followed by the putamen, midbrain, and caudate nucleus. Group III (n = 12) demonstrated T2-weighted images with increased signal intensity in the putamen (n = 10, 83%), followed by the caudate nucleus, globus pallidus, thalamus, midbrain, and pons. There was a significant difference in mean age, the presence of neurologic symptoms, and Child-Pugh classification among the 3 groups (P < .001). Following copper chelating therapy, the changes on follow-up MR imaging were strongly correlated with clinical response to treatment (P < .001).

CONCLUSION

Brain MR imaging in children with Wilson disease can be categorized into distinct groups and demonstrated a significant correlation with clinical findings. Interval changes on follow-up MR imaging were also closely correlated with clinical findings and helpful in assessing the clinical response.

Mutation spectrum of the glucose-6-phosphatase gene and its implication in molecular diagnosis of Korean patients with glycogen storage disease type Ia

Glycogen storage disease type Ia (GSD Ia; MIM 232200) is an autosomal recessive inherited metabolic disorder resulting from a deficiency of the microsomal glucose-6-phosphatase (G6Pase), the enzyme that catalyzes the terminal step in gluconeogenesis and glycogenolysis. Various mutations in the G6Pase gene (G6PC) have been found in patients with GSD Ia. To elucidate the spectrum of the G6PC gene mutations, 13 unrelated Korean patients with GSD Ia were analyzed. We were able to identify mutant alleles in all patients, including three known mutations (727G > T, G122D, and T255I) and two novel mutations (P178A and Y128X). The frequency of the 727G > T mutation in Korean patients with GSD Ia was 81% (21/26), which was slightly lower than that (86-92%) in Japanese but much higher than that (44.4%) in Taiwan Chinese. Except one, all patients were either homozygous (9/13) or compound heterozygous (3/13) for the 727G > T mutation; the only patient without the 727G > T mutation was a compound heterozygote for the G122D and Y128X mutations. Our findings suggest that a DNA-based test can be used as the initial diagnostic approach in Korean patients clinically suspected to have GSD Ia, thereby avoiding invasive liver biopsy.

Different patterns of lymphoscintigraphic findings in patients with intestinal lymphangiectasia

Technetium-99m antimony sulfide colloid lymphoscintigraphy conveniently demonstrates intestinal leakage of lymph in patients with intestinal lymphangiectasia. However, we found no intestinal radioactivity in some patients. We evaluated lymphoscintigraphic findings and compared them with clinical data. Technetium-99m antimony colloid lymphoscintigraphy was performed in 12 patients (age, 8.9+/-6.4 years; male:female=8:4) with histologically proven intestinal lymphangiectasia. After subcutaneous injection of 103.6 MBq of technetium-99m antimony colloid into the webs of both feet, sequential abdominal images were obtained up to 24 h post-injection. Four patients underwent technetium-99m methylene diphosphonate bone scintigraphy. Patients were divided into two groups according to the presence or absence of intestinal radioactivity. Five showed intestinal activity (Group 1), but seven did not (Group 2). No Group 1 patient had a history of ascites, while all Group 2 patients had ascites as the initial manifestation. Serum total protein and albumin levels were significantly lower in Group 1 patients than in Group 2 patients. In three Group 1 patients, technetium-99m methylene diphosphonate bone scintigraphy revealed intestinal radioactivity, while in one Group 2 patient this was not found. We observed two types of lymphoscintigraphic pattern in patients with intestinal lymphangiectasia. To clarify the exact pathophysiology, further study is required.

Seroepidemiological study of Helicobacter pylori infection in asymptomatic people in South Korea

BACKGROUND

Helicobacter pylori infection occurs throughout the world and causes gastroduodenal diseases in all age groups. The prevalence of H. pylori infection varies between countries and races. The aim of this study was to evaluate the seroprevalence of H. pylori infection in asymptomatic healthy people in South Korea.

METHODS

From March 1998 to October 1998, 5732 asymptomatic subjects who responded to the self-assessment questionnaires from 54 hospitals in South Korea were enrolled in this study. The serum levels of antibodies for H. pylori immunoglobulinG were measured by using an ELISA test.

RESULTS

The overall seroprevalence of H. pylori infection was 46.6% and there was no statistical difference between males (47.2%) and females (45.9%). In adults, a significant difference was observed between genders. According to the geographic areas, the high prevalent provinces were Kangwon (53.4%), Cheju (52.9%) and Cholla province (50.6%); Seoul (41.9%) was the lowest prevalent area. The seroprevalence increased with age and was highest when patients were aged in their 40s (78.5%). The characteristic feature of our study was that the infection rate was steeply increased in three age groups (10-12 year olds, 16-19 year olds and those aged in their 20s). In Seoul, there was no difference in the prevalence rate among the districts studied.

CONCLUSIONS

This nation-wide seroprevalence of H. pylori infection in South Korea was 46.6%, which showed the transition from a developing country to a developed country. More studies on the epidemiological factors and the route of transmission of H. pylori infection should be warranted.

Aqueous extract isolated from Platycodon grandiflorum elicits the release of nitric oxide and tumor necrosis factor-alpha from murine macrophages

Herbal medicines are increasingly being utilized to treat a wide variety of disease processes. Aqueous extract from the root of Platycodon grandiflorum A. DC (Campanulaceae), Changkil (CK), is reported to have antitumor and immunomodulatory activities; however, the mechanism underlying its therapeutic effect is not known. In the present study we examined the effects of CK on the release of nitric oxide (NO) and tumor necrosis factor-alpha (TNF-alpha), and on the gene expression of iNOS and TNF-alpha in mouse macrophages. CK elicited a dose-dependent increase in NO and TNF-alpha production in cultured macrophages. CK significantly affected secretion at concentrations of more than 5 micrograms/ml, and its maximum effect was at concentration of 100 micrograms/ml. Reverse transcription polymerase chain reaction showed that increases in NO and TNF-alpha secretion were due to an increase in inducible NO synthase mRNA and TNF-alpha mRNA, respectively. Transient expression assays with NF-kappa B binding sites linked to the luciferase gene revealed that CK-induced increase of inducible NO synthase mRNA and TNF-alpha mRNA were mediated by the NF-kappa B transcription factor complex. These results demonstrate that CK stimulates NO and TNF-alpha release and is able to upregulate iNOS and TNF-alpha expression through NF-kappa B transactivation and this may be a mechanism whereby this herbal medicine elicits its therapeutic effects.

Interferon-alpha treatment of chronic hepatitis C in children with hemophilia

BACKGROUND

In children with hemophilia, hepatitis C virus (HCV) is the major cause of chronic liver disease. In this study, long-term efficacy of interferon-alpha was studied to determine the factors that predict a sustained response to interferon therapy in young children with hemophilia who have chronic hepatitis C.

METHODS

Seventeen Korean children with hemophilia and chronic hepatitis C were treated with 3.7 million units/m2 of interferon-alpha2a three times weekly for 6 months. Liver biopsy, pretreatment serum HCV RNA quantitation with competitive reverse transcription assay, and HCV genotyping with reverse hybridization assay were performed.

RESULTS

Hepatitis C virus genotypes 1a, 1b, and 2a were found in three (18%), five (29%), and six (35%) patients, respectively. Interferon-alpha was well tolerated, and the frequency of bleeding did not increase. Of the 17 patients, 7 (41%) had a sustained response for 3 years after the end of therapy. Patients with a sustained response had lower pretreatment serum HCV RNA levels. One (13%) of eight patients with genotype 1 and five (83%) of six with genotype 2 had a sustained response (P < 0.05).

CONCLUSIONS

Interferon-alpha treatment of chronic hepatitis C in children with hemophilia was safe and effective in producing sustained responses. The pretreatment serum HCV RNA level and viral genotype may be predictive factors for sustained response to interferon therapy.

2,2',4,6,6'-pentachlorobiphenyl induces apoptosis in human monocytic cells

Polychlorinatedbiphenyls (PCBs) are a group of persistent and widely dispersed environmental pollutants, some of which may be immunotoxic. In the present study, we investigated the effect of PCBs on immune system by assessing apoptotic cell death in human monocytic U937 cells. Among the various congeners tested, 2,2',4,6, 6'-pentachlorobiphenyl (PeCB), a highly ortho-substituted congener, specifically induced DNA fragmentation, a hallmark of apoptosis, while the other examined di-, tri-, tetra-, and pentachlorobiphenyls did not. To further study the 2,2',4,6,6'-PeCB-induced cell death, various features of apoptosis were examined. 2,2',4,6,6'-PeCB caused a decrease in cell viability and induced cellular morphologic features characteristic of apoptosis such as chromatin aggregation and apoptotic bodies. In addition, caspase-3, an executioner of apoptosis, was activated and its substrate, poly(ADP-ribose) polymerase (PARP), was cleaved during 2,2',4,6,6'-PeCB-induced apoptosis. In contrast, 3,3',4,4',5-PeCB, a congener of coplanar structure, as well as 2,3,7,8-TCDD did not induce apoptosis in these human monocytic cells, although they potently induced CYP 1A1 in human hepatoma Hep G2 cells. Taken together, the data indicate that 2,2',4,6,6'-PeCB induces apoptosis in human monocytic cells through a mechanism that is independent of the arylhydrocarbon receptor. This suggests a possibly separate mechanism by which PCBs cause immunosuppression.

Interleukin-6-induced tyrosine phosphorylation of phospholipase C-gamma1 in PC12 cells

Phospholipase C (PLC)-gamma1 plays a pivotal role in the signal transduction pathway mediated by growth factors. In this study, we found that neurite outgrowth of pheochromocytoma (PC12) cells was significantly induced by interleukin-6 (IL-6). Stimulation of PC12 cells with IL-6 led to tyrosine phosphorylation of PLC-gamma1 in a dose- and time-dependent manner. IL-6 stimulation also increased the hydrolysis of phosphatidylinositol 4,5-bisphosphate. Accumulation of total inositol phosphate as well as tyrosine phosphorylation of PLC-gamma1 was inhibited by the pretreatment of protein kinase inhibitors such as genistein and staurosporine. These results suggest that PLC-gamma1 may be involved in the signal transduction pathway of IL-6-induced PC12 cell differentiation.

Overview of rotavirus infections in Korea

Rotavirus is the most common cause of acute watery diarrhea in young Korean children. Rotavirus vaccine will soon be available, and information is urgently required about the serotype distribution of recent epidemics and clinical characteristics of rotavirus infection in Korean children before the implementation of a vaccination program against rotavirus. We reviewed published studies of the past 20 years, carried out on Korean children with rotavirus gastroenteritis. Rotavirus was estimated to be responsible for 46% of 4668 hospitalized Korean children with acute gastroenteritis. Rotavirus gastroenteritis was most prevalent among children aged 6-24 months, which accounted for 84% of all cases. Asymptomatic rotavirus infection was common. Rotavirus was one of the most commonly identified enteric pathogens in nosocomial diarrhea. Vomiting, respiratory symptoms and fever were prominent symptoms in rotavirus gastroenteritis. Transient elevation of liver enzymes, pulmonic infiltration and rarely afebrile convulsion were also observed. The epidemic peak, which occurred in November of the last 15 years, has been moving toward late winter and early spring in recent years. No apparent cause has been found to explain this alteration of peak seasonality. All serotyping studies in Korea for the past 10 years until 1997 revealed that G1 was most prevalent (45-81%). Interestingly, the predominant G serotype of the recent outbreaks in 1998 and 1999 was not G1 but G4. Approximately 95% of rotavirus isolates in recent outbreaks belonged to serotype G1, 2, 3 or 4.

Congenital intrahepatic portohepatic venous shunt: treatment with coil embolisation

Congenital abnormalities of the portal venous system are rare. There are few radiological descriptions of intrahepatic portosystemic venous shunt detected in the perinatal period. We report a congenital portosystemic shunt that was detected by US and treated with coil embolisation in the neonatal period.

Multicenter study of the treatment of erectile dysfunction with transurethral alprostadil (MUSE) in Korea

A Korean multicenter study was conducted to assess the effectiveness of transurethral alprostadil with MUSE in 334 subjects with chronic erectile dysfunction (ED) who were enrolled in 21 clinical centers. Patients with psychogenic impotence comprised about 30% of subjects. Intraurethral alprostadil was titrated in a stepwise fashion in the clinics from 250 to 500 or 1000 mcg based on erectile response and tolerability. The erectile responses were evaluated using an erection assessment scale (score of 1-5). The dose that produced a maximal penile response of score 5 (full rigid erection) or 4 (full tumescence, partial rigidity) was selected for home treatment. Patients who showed partial erection (score of 3) with 1000 mcg were also included in the home-treatment group. In-clinic phase: 198 men (59.3%) had maximal penile responses of score 4 or 5. The rate of maximal responses was not related to patient age, etiology or duration of the ED. A total of 228 (68.3%) men progressed to home treatment. The overall level of comfort of the transurethral alprostadil was rated as uncomfortable or very uncomfortable in 12%. Home phase: During the two-month period of home treatment, 178 (78.1%) men had successful sexual intercourse at least once, and 78.2% of administrations (1976) resulted in successful intercourse. The main causes of drop-out were insufficient erectile response in 27 men (11.8%), adverse reactions (mostly penile or urethral pain) in 7 (3.1%) or both in 7 (3.1%). In conclusion, transurethral alprostadil could be a suitable treatment option for patients with ED regardless of age and etiology of ED. Efficacy in an Asian population (Korea) is comparable to that reported previously in Caucasians.

Transoral protrusion of a peritoneal catheter: a case report and literature review

Transoral protrusion of a peritoneal catheter is rare. Only two cases have been reported in the English literature. We now report the case of a 5-year-old girl who presented with a catheter that had been inserted 4 years previously, protruding from her mouth. Signs of cerebrospinal fluid infection or peritonitis were absent. The peritoneal catheter was cut and externalized at the chest. The distal portion, which had perforated the stomach wall, was removed using endoscopic procedures. After 3 weeks of antibiotic treatment, a new shunt was inserted. Analysis of 50 cases of bowel perforation extracted from the English literature showed that among the suggested factors such as age, gender, nutritional state, history of abdominal surgery, and length and type of the catheter, age was the only predisposing factor. In the treatment of bowel perforation by a peritoneal catheter, suspected shunt infection should be managed properly and contamination be minimized during removal of the peritoneal catheter.

Trp-Lys-Tyr-Met-Val-Met activates mitogen-activated protein kinase via a PI-3 kinase-mediated pathway independent of PKC

Trp-Lys-Tyr-Met-Val-Met (WKYMVM) is a novel potent peptide which can stimulate phosphoinositide hydrolysis in U937 as well as U266 and HL-60 cells (Baek et al., J. Biol. Chem. 271, 8170 (1996)). The peptide also induces superoxide generation in human neutrophils (Seo et al., J. Immunol. 158, 1896 (1997)). However, the signaling pathway down-stream of PLC set in motion by the peptide is not yet completely understood. We studied the signaling pathway of the peptide with the goal of elucidating the mechanism of the peptide's action. WKYMVM induced a rapid and transient activation of the ERKs in human histiocytic lymphoma cells, U937. The ERK1 activation peaked at 5 min and returned to the basal level after 30 min. The ERK1 stimulation by the peptide was partially inhibited by pretreatment of the cells with pertussis toxin (PTX), implicating G-protein involvement in the peptide's action. Pretreatment of staurosporine, protein kinase C (PKC) inhibitor, or PKC down-regulating PMA had no impact on the ERK1 activation by the peptide, indicating that the signaling pathway is independent of PKC activation. Pretreatment of the cells with neomycin and intracellular Ca2+ mobilizing reagents had also no effect on the ERK1 activation by the peptide. However, pretreatment with wortmannin or LY294002, the inhibitor of phosphatidylinositol 3 kinase (PI-3K), strongly inhibited peptide-stimulated ERK1 activation. Our results suggest that PI-3K may be an important participant in the ERK cascade induced by the peptide. Furthermore, the treatment of U937 cells with the peptide activated p74Raf-1, an upstream kinase of ERK. Taken together, our results suggest that the peptide activate ERK via a G-protein/PI-3K/Ras/Raf-1 mediated signaling pathway in U937 cells.