Longitudinal associations between gut microbiome diversity and emotional well-being

OBJECTIVE

While a significant link between emotional well-being (EWB) and the gut microbiome has been reported recently, their temporal relationships remain elusive. This study aims to fill this gap by examining the longitudinal associations between EWB and the Shannon Index (SI), an indicator of gut microbiome diversity.

METHOD

The analysis focused on a dataset that collected participants' current EWB and fecal samples in both 2019 and 2022 (N = 57, 56.1% female, Mage = 52.47 years, SD = 12.65). Gut microbiome profiles were generated by sequencing the 16S rRNA gene, from which SI was subsequently calculated.

RESULTS

The cross-lagged panel analysis revealed significant positive cross-sectional associations between EWB and SI in both 2019 (β = .296, SE = 0.121, p = .014) and 2022 (β = .324, SE = 0.119, p = .006). However, no significant longitudinal associations were found between 2019 EWB and 2022 SI (β = .068, SE = 0.138, p = .623), nor between 2019 SI and 2022 EWB (β = -.016, SE = 0.13, p = .899).

CONCLUSIONS

Our findings indicate that emotional happiness may be associated with gut microbiome profiles at a particular time point, but they may not serve as predictive factors for each other over time. Future research is needed to establish causal relationships between them. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Gut microbial and clinical characteristics of individuals with autism spectrum disorder differ depending on the ecological structure of the gut microbiome

Understanding the relationship between the gut microbiome and autism spectrum disorder (ASD) is challenging due to the heterogeneous nature of ASD. Here, we analyzed the microbial and clinical characteristics of individuals with ASD using enterotypes. A total of 456 individuals participated in the study, including 249 participants with ASD, 106 typically developing siblings, and 101 controls. The alpha and beta diversities of the ASD, sibling, and control groups did not show significant differences. Analysis revealed a negative association between the Bifidobacterium longum group and the Childhood Autism Rating Scale, as well as a negative association between the Streptococcus salivarus group and the Social Responsiveness Scale (SRS) within the ASD group. When clustered based on microbial composition, participants with ASD exhibited two distinct enterotypes, E1 and E2. In the E2 group, the SRS score was significantly higher, and the Vineland Adaptive Behavior Scale score was significantly lower compared to the E1 group. Machine learning results indicated that the microbial species predicting SRS scores were distinct between the two enterotypes. Our study suggests that the microbial composition in individuals with ASD exhibits considerable variability, and the patterns of associations between the gut microbiome and clinical symptoms may vary depending on the enterotype.

Comparison of clinical outcomes of patients with serial negative surveillance cultures according to a subsequent polymerase chain reaction test for carbapenemase-producing Enterobacterales

BACKGROUND

Carbapenemase-producing Enterobacterales (CPE) are of serious concern worldwide due to high morbidity and mortality.

AIM

To evaluate the impact of the result of a subsequent polymerase chain reaction (PCR) test for carbapenemase after serial negative surveillance cultures on positive culture conversion in patients with three consecutive negative surveillance cultures for CPE, and to identify risk factors for conversion.

METHODS

A retrospective study of patients with positive CPE cultures on CHROMagar KPC medium was performed in a Korean tertiary hospital from October 2018 to December 2022. PCR for blaKPC, blaNDM, blaIMP, blaVIM, blaGES, and blaOXA-48 was performed after three consecutive negative rectal swab cultures. Clinical characteristics and outcomes of patients were compared according to whether follow-up PCR was positive (CNPP) or negative (CNPN).

FINDINGS

Of 1075 patients with positive CPE cultures, 150 (14.0%) yielded three consecutive negative rectal swab cultures. Of these, 50 (33.3%) were CNPP, and 100 (66.7%) were CNPN. Risk factors associated with a positive PCR result on multivariate analysis were: age, central venous catheter, and Escherichia coli infection. CNPP patients were more likely to have positive culture conversion for CPE than CNPN patients (39/44 (88.6%) vs 21/50 (42.0%), P<0.001). In multivariate analysis, independent risk factors for culture conversion were: a positive PCR result after surveillance cultures, diabetes mellitus, central venous catheter, and Klebsiella pneumoniae.

CONCLUSION

CNPP patients have higher rates of culture conversion than CNPN patients, and a follow-up PCR test after serial negative surveillance cultures is useful in deciding whether or not to discontinue contact precautions.

Gut microbial signatures in clinically stable ulcerative colitis according to the mucosal state and associated symptoms

BACKGROUND AND AIM

The gut microbiome of patients with clinically stable ulcerative colitis (UC) differs from that of healthy individuals depending on the state of the colonic mucosa, especially with or without advanced scarring; however, the underlying mechanism is unclear. Therefore, this study examined the gut microbiome compositional signatures in patients with significant mucosal scarring and UC-related symptoms.

METHODS

Stool samples for gut microbiome analysis were prospectively collected from 57 patients with clinically stable UC between January 1 and December 31, 2022. Data from 57 individuals without inflammatory bowel disease (non-IBD) paired by age and sex were selected from our previous study as the control group. The fecal samples were subjected to 16S rRNA gene sequencing. Associations between gut microbiome profiles and clinical or colonoscopic assessments were examined using diversity and differential abundance analyses.

RESULTS

Gut microbiome compositions between the patients with clinically stable UC and non-IBD controls differed significantly. Furthermore, gut microbiome compositions varied between the preserved and altered mucosa groups identified based on mucosal changes in the UC group. Differential abundance test of patients with UC for symptomatic remission based on stool frequency from the two-item patient-reported outcome identified several overlapping taxa specified as gut microbiome signatures, including the Enterobacteriaceae unknown genera (Enterobacteriaceae_g), Klebsiella, and several Lachnospiraceae spp. both in mucosal and symptom change analyses.

CONCLUSIONS

The gut microbiome can change with mucosal changes, even in clinically stable UC, and some gut microbial signatures may explain the symptom manifestations in patients with UC showing significant mucosal changes.

MRI Detection of Lymph Node Metastasis through Molecular Targeting of C-C Chemokine Receptor Type 2 and Monocyte Hitchhiking

Biopsy is the clinical standard for diagnosing lymph node (LN) metastasis, but it is invasive and poses significant risk to patient health. Magnetic resonance imaging (MRI) has been utilized as a noninvasive alternative but is limited by low sensitivity, with only ∼35% of LN metastases detected, as clinical contrast agents cannot discriminate between healthy and metastatic LNs due to nonspecific accumulation. Nanoparticles targeted to the C-C chemokine receptor 2 (CCR2), a biomarker highly expressed in metastatic LNs, have the potential to guide the delivery of contrast agents, improving the sensitivity of MRI. Additionally, cancer cells in metastatic LNs produce monocyte chemotactic protein 1 (MCP1), which binds to CCR2+ inflammatory monocytes and stimulates their migration. Thus, the molecular targeting of CCR2 may enable nanoparticle hitchhiking onto monocytes, providing an additional mechanism for metastatic LN targeting and early detection. Hence, we developed micelles incorporating gadolinium (Gd) and peptides derived from the CCR2-binding motif of MCP1 (MCP1-Gd) and evaluated the potential of MCP1-Gd to detect LN metastasis. When incubated with migrating monocytes in vitro, MCP1-Gd transport across lymphatic endothelium increased 2-fold relative to nontargeting controls. After administration into mouse models with initial LN metastasis and recurrent LN metastasis, MCP1-Gd detected metastatic LNs by increasing MRI signal by 30-50% relative to healthy LNs. Furthermore, LN targeting was dependent on monocyte hitchhiking, as monocyte depletion decreased accumulation by >70%. Herein, we present a nanoparticle contrast agent for MRI detection of LN metastasis mediated by CCR2-targeting and demonstrate the potential of monocyte hitchhiking for enhanced nanoparticle delivery.

Effects of the multidomain intervention with nutritional supplements on cognition and gut microbiome in early symptomatic Alzheimer's disease: a randomized controlled trial

Background

The SoUth Korean study to PrEvent cognitive impaiRment and protect BRAIN health through lifestyle intervention in at-risk elderly people (SUPERBRAIN) is a part of the World-Wide Finnish Geriatric Intervention Study to Prevent Cognitive Impairment and Disability (WW-FINGERS) network. This study aimed to demonstrate the effects of the SUPERBRAIN-based multidomain intervention with nutritional supplements in amyloid positive emission tomography (PET) proven early symptomatic Alzheimer's disease patients.

Methods

Forty-six participants who were diagnosed with mild cognitive impairment or mild dementia and were positive in the amyloid PET study randomized into three groups: group A, the multidomain intervention with nutritional supplements; group B, nutritional supplements only; and a control group. The primary outcome was a change in the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) total scale index score after an 8-week intervention. Secondary outcomes, including gut microbiome data, were also analyzed.

Results

The RBANS total scale index score improved significantly in group A compared with group B (p < 0.032) and compared with the control group (p < 0.001). After intervention, beta diversity of the gut microbiome between group A and the control group increased, and patients in group A were more enriched with Bifidobacterium.

Conclusion

SUPERBRAIN-based multidomain intervention with nutritional supplements improves cognition and gut microbiota in patients with early symptomatic Alzheimer's disease who were amyloid-positive by PET.

Proposal of a health gut microbiome index based on a meta-analysis of Korean and global population datasets

The disruption of the human gut microbiota has been linked to host health conditions, including various diseases. However, no reliable index for measuring and predicting a healthy microbiome is currently available. Here, the sequencing data of 1,663 Koreans were obtained from three independent studies. Furthermore, we pooled 3,490 samples from public databases and analyzed a total of 5,153 fecal samples. First, we analyzed Korean gut microbiome covariates to determine the influence of lifestyle on variation in the gut microbiota. Next, patterns of microbiota variations across geographical locations and disease statuses were confirmed using a global cohort and di-sease data. Based on comprehensive comparative analysis, we were able to define three enterotypes among Korean cohorts, namely, Prevotella type, Bacteroides type, and outlier type. By a thorough categorization of dysbiosis and the evaluation of microbial characteristics using multiple datasets, we identified a wide spectrum of accuracy levels in classifying health and disease states. Using the observed microbiome patterns, we devised an index named the gut microbiome index (GMI) that could consistently predict health conditions from human gut microbiome data. Compared to ecological metrics, the microbial marker index, and machine learning approaches, GMI distinguished between healthy and non-healthy individuals with a higher accuracy across various datasets. Thus, this study proposes a potential index to measure health status of gut microbiome that is verified from multiethnic data of various diseases, and we expect this model to facilitate further clinical application of gut microbiota data in future.

Comparison of sampling methods in assessing the microbiome from patients with ulcerative colitis

Background

Dysbiosis of ulcerative colitis (UC) has been frequently investigated using readily accessible stool samples. However, stool samples might insufficiently represent the mucosa-associated microbiome status. We hypothesized that luminal contents including loosely adherent luminal bacteria after bowel preparation may be suitable for diagnosing the dysbiosis of UC.

Methods

This study included 16 patients with UC (9 men and 7 women, mean age: 52.13 ± 14.09 years) and 15 sex- and age-matched healthy individuals (8 men and 7 women, mean age: 50.93 ± 14.11 years). They donated stool samples before colonoscopy and underwent luminal content aspiration and endoscopic biopsy during the colonoscopy. Then, the composition of each microbiome sample was analyzed by 16S rRNA-based next-generation sequencing.

Results

The microbiome between stool, luminal contents, and biopsy was significantly different in alpha and beta diversities. However, a correlation existed between stool and luminal contents in the Procrustes test (p = 0.001) and Mantel test (p = 0.0001). The stool microbiome was different between patients with UC and the healthy controls. Conversely, no difference was found in the microbiome of luminal content and biopsy samples between the two subject groups. The microbiome of stool and lavage predicted UC, with AUC values of 0.85 and 0.81, respectively.

Conclusion

The microbiome of stool, luminal contents, and biopsy was significantly different. However, the microbiome of luminal contents during colonoscopy can predict UC, with AUC values of 0.81. Colonoscopic luminal content aspiration analysis could determine microbiome differences between patients with UC and the healthy control, thereby beneficial in screening dysbiosis via endoscopy.

Trial registration: This trial was registered at http://cris.nih.go.kr. Registration No.: KCT0003352), Date: 2018–11-13.

Evaluation of hepatic injury in acute carbon monoxide-poisoned patients in emergency department

Introduction:

The affinity of hemoglobin for carbon monoxide (CO) is 250 times higher than that for oxygen. Therefore, exposure to CO leads to a reduction in oxygen delivery to tissues, resulting in cellular hypoxia and affects whole body. Hepatic dysfunction in critically ill patients is related to poor outcome, but few studies have been conducted on this subject that occurs after CO poisoning. This study aims to conduct a study of hepatic injury in CO-poisoned patients in emergency department (ED).

Methods:

This retrospective observational study collected data from patients who were diagnosed with acute CO poisoning at the ED between June 2011 and May 2018 in local tertiary-care hospital (Wonju, Republic of Korea). The primary end point of this study was to describe the prevalence of hepatic injury in acute CO-poisoned patients. The secondary goals were to investigate the recovery trends of hepatic injury caused by acute CO poisoning and the relation to neurologic outcome and mortality.

Results:

Eight hundred ninety-four patients were enrolled in the final analysis, 128 cases (14.3%) had subclinical hepatic injury and 15 (1.6%) cases had hepatic injury. The relationship with mortality was not statistically significant. However, the hepatic injury group was higher incidence of intensive care unit admission and other complications. Patients in the hepatic injury group recovered through conservative management within 1 week of being admitted to the ED.

Conclusions:

While CO-induced hepatic injury is relatively uncommon, it can be associated with complications and poor neurologic outcome. However, CO-induced hepatic injury was not found to have a statistically significant effect on mortality rate.

Early cidofovir administration might be associated with a lower probability of respiratory failure in treating human adenovirus pneumonia: a retrospective cohort study

Objective

To compare outcomes of early and delayed treatment with cidofovir for human adenovirus (HAdV) pneumonia.

Methods

A retrospective cohort study in Korean military hospitals was conducted between January 2012 and December 2018. Patients with potentially severe HAdV pneumonia with risk factors for respiratory failure were included and divided into early (within 7 days from symptom onset) and delayed (after 7 days from symptom onset) treatment groups. The primary outcome was respiratory failure development within 21 days after symptom onset.

Results

A total of 89 patients with potentially severe HAdV pneumonia were enrolled in the cohort; they included 62 early and 27 delayed treatment patients. All patients were males in their early 20s. Significantly fewer patients in the early treatment group progressed to respiratory failure (8/62, 12.9%), compared to the delayed group (18/27, 66.7%, p < 0.001). Early treatment was associated with a lower 21-day probability of respiratory failure by the Kaplan–Meier method (p < 0.001). On multivariate analysis, monocyte count, hypoxaemia, confusion, whole lung involvement, and early cidofovir treatment within 7 days from symptom onset were included, and monocyte count (HR 0.995, 95%CI 0.991–1.000, p 0.042), confusion (HR 4.964, 95%CI 1.189–20.721, p = 0.028), and early cidofovir treatment (HR 0.319, 95%CI 0.115–0.883, p = 0.028) were significantly associated with respiratory failure.

Conclusions

Early administration of cidofovir was associated with a lower hazard for respiratory failure development. It is suggested that cidofovir be administered within 7 days from symptom onset to prevent respiratory failure in patients with potentially severe HAdV pneumonia.

Triticum aestivum ethanolic extract improves non-alcoholic fatty liver disease in mice fed a choline-deficient or high-fat diet

BACKGROUND

Although non-alcoholic fatty liver disease (NAFLD) has become more prevalent with the rapid increase of obesity worldwide, no specific treatment has been developed. Several studies have shown that wheatgrass extract Triticum aestivum (TA) improves lipid metabolism. In the present study, we evaluated the efficacy of GM-T (an ethanolic TA extract) in a murine NAFLD model. Mice were separated into 12 groups (n = 10): two groups of normal diet, choline-deficient diet (CDD) or high-fat diet (HFD) with vehicle, CCD or HFD with silymarin (400 mg kg^-1 day^-1 ), and CCD or HFD with GM-T (100, 200 or 400 mg kg^-1 day^-1 ). The study was performed for 8 weeks for the CDD groups and 12 weeks for the HFD groups.

RESULTS

In the CDD-fed mice, GM-T improved serum liver enzyme activities and liver inflammation score compared to vehicle. In the HFD-fed mice, GM-T improved blood lipid profiles, liver inflammation score, steatosis score and obesity compared to vehicle.

CONCLUSION

The present study demonstrated that GM-T effectively improved NAFLD in mice via a mechanism that improved insulin resistance and lipid metabolism, suggesting the possibility of a functional dietary supplement to improve liver health, overall metabolic syndrome and obesity. © 2018 Society of Chemical Industry.

Effects of l-arginine on growth hormone and insulin-like growth factor 1

l-Arginine has been reported to promote cellular and organismal growth. In this study, the effects of l-arginine on the expression of growth hormone (GH) and insulin-like growth factor 1 (IGF-1), the two key growth factors, are investigated in cultured GH3 pituitary epithelium and HepG2 cells, respectively. l-Arginine significantly induced the gene expression of GH and IGF-1 in GH3 pituitary epithelium and HepG2 hepatocytes respectively, and reduced IGF binding protein-1 gene expression in HepG2 cells assessed via quantitative polymerase chain reaction analysis. l-Arginine also significantly induced GH and IGF-1 hormone secretion from GH3 and HepG2 cells, respectively. In addition, the multi-target ELISA analysis conducted revealed that phosphorylation of p-38 MAPK, MEK, and JNK were significantly increased in HepG2 cells, suggesting l-arginine-induced activation of the MAPK signaling pathway. These results suggest that l-arginine promotes the synthesis and secretion of GH and IGF-1 in vitro and induces the MAPK signaling cascade in cultured hepatocytes.

Synthesis of silica nanoparticles using biomimetic mineralization with polyallylamine hydrochloride

To synthesize silica particles under mild conditions, we proposed a biomimetic synthesis method. The synthesis process was carried out based on a biphasic sol-gel synthesis method using TEOS (tetraethyl orthosilicate) as a silica source and PAH (polyallylamine) as a substitute for proteins of marine microorganisms for biosilicification. The function and activity of the PAH, used as a replacement for bioactive substances, were confirmed through comparisons between control experiments and designed experiments. The PAH exhibited the ability accelerate condensation with hydrolyzed TEOS in aqueous solutions. The PAH also exhibited high condensation activity in acidic and neutral conditions to produce silica particles. Moreover, PAH also created the nuclei of the silica particles, and the number of nuclei could be controlled by the concentration of PAH. In addition to exhibiting these unique capabilities, PAH did not generate any complexes or composites with the silica species. Depending on the synthesis conditions, the synthesized silica particles exhibited various shapes, such as sponge-like, self-assembled, irregular spherical and completely spherical shapes. The sizes of the primary particles were diverse, with a range from 10nm to 50nm. In particular, by adjusting the PAH concentration, it was possible to obtain nearly perfect spherical-shaped silica nanoparticles with uniform sizes, which has rarely been reported. Above all, using this paper, we can get closer to understanding the principles of silica formation using PAH as a replacement for the bioactive proteins of microorganisms.

Comparison of the Posterior Vertebral Column Resection With the Expandable Cage Versus the Nonexpandable Cage in Thoracolumbar Angular Kyphosis

STUDY DESIGN

This was a retrospective study.

OBJECTIVE

To compare the radiographic and clinical results of anterior support with nonexpandable cage with those of expandable cage.

SUMMARY OF BACKGROUND DATA

The goals of surgical treatment in patients with thoracolumbar angular kyphosis are to improve the neurological deficit through neural decompression, to restore the normal alignment by correction of deformity, and to stabilize the spinal column by arthrodesis. Mesh cages have been traditionally used for reconstruction after corpectomy. However, expandable cages are gaining popularity due to some advantages over mesh cages, structural autograft or allograft, and poly-ether-ether-ketone/carbon fiber.

MATERIALS AND METHODS

We performed a retrospective study in a consecutive series of 42 subjects with a male-to-female ratio of 15:27, a mean age of 65.3±10.9 years, and a mean follow-up period of 36.4±7.1 months, who underwent posterior vertebral column resection at our medical institutions between 2006 and 2011. They consist of 32 patients with posttraumatic kyphosis with a mean kyphotic angle of 33.1 degrees (range, 12.2-58.1 degrees) and 10 patients with tuberculous kyphosis with a mean kyphotic angle of 53.9 degrees (range, 22.6-126.0 degrees). The mean follow-up period was 36.4 months (range, 28-54 mo). We compared the clinical outcomes between the 2 groups based on radiographic findings, neurological status, and complications. Intervertebral heights and kyphosis at the level of vertebral column resection were used to measure the radiographic outcomes. Neurological outcome was evaluated using the modified Frankel grading system.

RESULTS

Postoperatively, the mean kyphosis angle was 3.0±10.8 and 6.7±7.2 degrees (P=0.094). At a final follow-up, these values were 4.7±10.1 and 12.3±18.9 degrees in the corresponding order (P=0.099). There were 19 (80.0%) and 21 (86.4%) patients with solid arthrodesis of grade 1. On modified Frankel grading system, all the patients but one achieved improvement. But there was no significant difference in the grade between the 2 groups (P>0.05). Also in our series, there were 12 patients with cage subsidence and 6 with screw loosening.

CONCLUSIONS

Nonexpandable cage and expandable cage are viable options for anterior support; both cages allow for correction of kyphosis with good fusion rate with similar neurological outcomes. Expandable cage is effective for the anterior support of posterior vertebral column resection.

Effects of Dexmedetomidine Infusion on the Recovery Profiles of Patients Undergoing Transurethral Resection

Transurethral resection has been the gold standard in the operative management of benign prostatic hyperplasia and bladder tumor; however, it is associated with several complications that may cause patient discomfort. We evaluated the usefulness of continuous infusion of dexmedetomidine on emergence agitation, hemodynamic status, and recovery profiles in patients undergoing elective surgery by a randomized clinical trial. Sixty patients aged 30 to 80 yr who were scheduled for elective transurethral resection under general anesthesia were included in this study. Participants were randomly assigned to two groups (control group, group C; dexmedetomidine group, group D). A total of 60 male patients were enrolled in this study and randomly assigned to group C (n=30) or group D (n=30). The quality of emergence in group D was marked by a significantly lower incidence of emergence agitation than in group C (P=0.015). Patients in group D therefore felt less discomfort induced by the indwelling Foley catheter than those in group C (P=0.022). No statistically significant differences were found between the two groups with respect to side effects including bradycardia (P=0.085), hypotension (P=0.640), and postoperative nausea and vomiting (P=0.389). Our study showed that intraoperative dexmedetomidine infusion effectively reduced the incidence and intensity of emergence agitation and catheter-induced bladder discomfort without delaying recovery time and discharge time, thus providing smooth emergence during the recovery period in patients undergoing transurethral resection (Clinical Trial Registry No. KT0001683).

Clinical Prognostic Factors and Treatment Outcome of Aggressive Non-Hodgkin's Lymphoma in Elderly Patients

PURPOSE

The aim of this study was to determine the prognostic factors and treatment outcome of for elderly patients (age>or=60 at time of diagnosis) with aggressive non-Hodgkin's lymphoma (NHL).

MATERIALS AND METHODS

We analyzed 52 patients diagnosed with aggressive NHL between January 1990 and May 2000.

RESULTS

The patient's median age was 69 years (range: 60~92). Thirty-two (61.5%) patients were male. Patients included those with diffuse large B cell (53.8%), peripheral T cell (23.1%), AILD-like T-cell (3.8%), angiocentric (3.8%), mantle cell (3.8%), Burkitt's lymphoma (3.8%), and others (7.9%). International prognostic index (IPI) parameters were as follows: elevated LDH (60.8%), ECOG performance status>or=2 (32.7%), advanced stage (III/IV, 62.7%), and extranodal site>or=2 (11.5%). Twenty-six (50.0%) patients demonstrated a high and high-intermediate IPI. The median follow-up for surviving patients was 26.6 months. The overall median survival was 22.7 months and the 2-year survival rate was 46.9%. Among the 49 patientstreated with chemotherapy, 28 (57.1%) patients achieved complete remission (CR). Univariate analysis identified 8 prognostic factors for overall survival: age<70 (P=0.04), low/low-intermediate IPI (P=0.02), good performance (P= 0.04), normal WBC (P=0.008), normal Hb (P=0.02), normal LDH (P=0.04), CR on first line therapy (P<0.001), and absence of B symptom (P=0.001). In the multivariate analysis, the independent prognostic factors for improved overall survival were age <70 (P=0.03), low/low-intermediate IPI (P=0.03), normal WBC (P=0.006), and CR on first line therapy (P<0.001).

CONCLUSION

In our experience, even elderly patients (>or=60 years) with aggressive NHL can be successfully treated with conventional chemotherapy and the important prognostic factors for survival are age, IPI, initial WBC, and CR on first line treatment.

Towards a taxonomic coherence between average nucleotide identity and 16S rRNA gene sequence similarity for species demarcation of prokaryotes

Among available genome relatedness indices, average nucleotide identity (ANI) is one of the most robust measurements of genomic relatedness between strains, and has great potential in the taxonomy of bacteria and archaea as a substitute for the labour-intensive DNA-DNA hybridization (DDH) technique. An ANI threshold range (95-96%) for species demarcation had previously been suggested based on comparative investigation between DDH and ANI values, albeit with rather limited datasets. Furthermore, its generality was not tested on all lineages of prokaryotes. Here, we investigated the overall distribution of ANI values generated by pairwise comparison of 6787 genomes of prokaryotes belonging to 22 phyla to see whether the suggested range can be applied to all species. There was an apparent distinction in the overall ANI distribution between intra- and interspecies relationships at around 95-96% ANI. We went on to determine which level of 16S rRNA gene sequence similarity corresponds to the currently accepted ANI threshold for species demarcation using over one million comparisons. A twofold cross-validation statistical test revealed that 98.65% 16S rRNA gene sequence similarity can be used as the threshold for differentiating two species, which is consistent with previous suggestions (98.2-99.0%) derived from comparative studies between DDH and 16S rRNA gene sequence similarity. Our findings should be useful in accelerating the use of genomic sequence data in the taxonomy of bacteria and archaea.

Extradural cyst causing spinal cord compression in osteoporotic compression fracture

Intraspinal cystic lesions with different pathogeneses have been reported to cause neurological deficits; however, no one has focused on the intraspinal extradural cysts that develop after osteoporotic compression fracture. The reported case features a 66-year-old woman presenting with progressive neurological deficit, back pain, and no history of additional trauma after undergoing conservative treatment for an osteoporotic fracture of L-1. The authors present serial radiographs and MR images demonstrating an epidural cyst successfully treated via a single posterior approach. This appears to be the first such case reported in the literature.

Epidemiological characteristics of occupational blood exposures of healthcare workers in a university hospital in South Korea for 10 years

This study investigated the epidemiological characteristics of occupational blood exposures (OBEs) of healthcare workers (HCWs) in South Korea, and examined trends of OBEs after implementing blood exposure prevention (BEP) programmes. The study was conducted between 1 January 1992 and 31 December 2001 at a university-affiliated acute care hospital in Seoul. The BEP programmes comprised in-service education, hepatitis B virus (HBV) vaccination, and postexposure evaluation and prophylaxis. From 959 reported cases of OBEs, the crude incidence density (ID) was 2.62 cases per 100 person-years. The major risk groups for OBEs were physicians (ID 4.34) and new employees. The major type of OBE was from sharps injuries, including needlesticks (94.0%). OBE cases occurred more frequently during the spring (36.4%). The frequency of the serological tests of anti-hepatitis B surface antigen of HCWs changed significantly each year (P<0.05). The major serological risk for source patients was HBV (52.1%), but the risks for hepatitis C virus (HCV) and human immunodeficiency virus (HIV) increased significantly each year (P<0.05). There were no seroconversion cases following OBEs among the tested HCWs. In summary, we established the epidemiological characteristics of OBEs in a South Korean university hospital, and reduced the risk of OBEs of major risk groups by BEP programmes. We also found an increase in the risk of HCV and HIV during the study period, suggesting that OBEs could be a serious threat to HCWs.

Mammary pseudoangiomatous stromal hyperplasia presenting as an axillary mass

Pseudoangiomatous stromal hyperplasia (PASH) of the breast is characterized by interanastomosing slit-like spaces lined with spindle-shaped cells in an abundant fibrous stroma. PASH is a relatively common incidental finding in the breast tissue removed for other reasons and rarely presents as a localized mass. The etiology of PASH is unknown, but hormonal factors are thought to be involved. Accessory breast tissue is subject to all pathologic changes found in the normal breast. We report a case of PASH that presented as a palpable axillary mass in a 43-year-old woman. To our knowledge, PASH has not previously been reported in the axillary accessory breast tissue. The spindle stromal cells in our patient showed immunophenotypic characteristics of myofibroblastic differentiation. Immunoreactivity for progesterone receptor was noted in the spindle cells. These findings support the hypothesis that endogenous hormones are involved in the development of PASH.

Substance p-fibronectin-cytokine interactions in myeloproliferative disorders with bone marrow fibrosis

Bone marrow (BM) fibrosis could occur secondarily to several clinical disorders: hematological and nonhematological. Clinical presentation of fibrosis could occur in myeloproliferative diseases, lymphoma, myelodysplastic syndrome and myeloma. The pathophysiology underlying BM fibrosis remains unclear despite intensive study, with a corresponding lack of specific therapy. This review discusses new insights in the role of substance P, cytokines and fibronectin in the development of BM fibrosis. Substance P is a neuropeptide that possesses pleiotropic properties, e.g. neurotransmission and immune/hematopoietic modulation and is linked to BM fibrosis. Cytokines and growth factors, in particular those associated with fibrogenic properties, e.g. TGF-beta, IL-1 and platelet-derived growth factor, are linked to BM fibrosis. Extracellular matrix proteins are increased in patients with BM fibrosis. Fibronectin in the sera of patients with BM fibrosis is complexed to substance P. Fibronectin appears to protect substance P from degradation by endogenous peptidases. This review describes the preliminary findings on the colocalization of substance P and fibronectin in the BM of patients with fibrosis. These data are reviewed in the context of published reports with particular focus on the relevant cytokines. A more detailed understanding of intra- and intercellular mechanisms in BM fibrosis may lead to effective therapy.

A Gene-for-Gene Relationship Underlying the Species-Specific Parasitism of Avena/Triticum Isolates of Magnaporthe grisea on Wheat Cultivars

ABSTRACT To elucidate genetic mechanisms of the species-specific parasitism of Magnaporthe grisea, a Triticum isolate (pathogenic on wheat) was crossed with an Avena isolate (pathogenic on oat), and resulting F(1) progeny were subjected to segregation analyses on wheat cvs. Norin 4 and Chinese Spring. We found two fungal loci, Pwt3 and Pwt4, which are involved in the specific parasitism on wheat. Pwt3 operated on both cultivars while Pwt4 operated only on 'Norin 4'. Using the cultivar specificity of Pwt4, its corresponding resistance gene was successfully identified in 'Norin 4' and designated as Rmg1 (Rwt4). The presence of the corresponding resistance gene indicated that Pwt4 is an avirulence locus. Pwt3 was assumed to be an avirulence locus because of its temperature sensitivity. We suggest that gene-for-gene interactions underlie the species-specific parasitism of M. grisea.

Characterization of anAvenaisolate ofMagnaporthe griseaand identification of a locus conditioning its specificity on oat

An isolate of Magnaporthe grisea was collected from a blast lesion on oat in Brazil. Sequence analysis of the rDNA-ITS-2 region and DNA fingerprinting with repetitive elements revealed that the Avena isolate belongs to the "crop isolate group" and is similar to Triticum isolates. At high temperature (28°C), the Avena isolate caused severe disease symptoms on primary leaves of oat and wheat. When the temperature was decreased to 20°C, wheat leaves expressed resistance to the Avena isolate. Cytologically, this temperature-dependent resistance was associated with an increase in the incidences of papilla formation and a hypersensitive reaction. Pathogenicity tests with various plant species at 20°C revealed that the Avena isolate is exclusively parasitic on oat. To elucidate genetic mechanisms of this species-specific parasitism, the Avena isolate was crossed with a Triticum isolate and resulting F1progenies were subjected to pathogenicity tests on oat seedlings. In the F1population, avirulent and virulent cultures segregated in a 1:1 ratio, suggesting that the specific parasitism on oat is controlled by a single gene. This locus was designated as Pat1.Key words: Magnaporthe grisea, species-specific parasitism, oat, temperature sensitive.

The Bradyrhizobium japonicum hsfA gene exhibits a unique developmental expression pattern in cowpea nodules

The Bradyrhizobium japonicum host-specific fixation gene hsfA was identified as essential for nitrogen fixation on cowpea, but not required for nitrogen fixation on soybean or siratro. The DNA sequence of the hsfA promoter contains a consensus RpoN, -24/-12 binding site, suggesting the involvement of a regulatory protein that binds to an upstream activating sequence (UAS). To further explore the regulation of this interesting gene, serial deletions of the hsfA promoter were made and fused with the beta-glucuronidase (GUS) gene. The HsfA3 deletion, containing 60 bp 5' of the -24/-12 sequence, showed a similar level of GUS expression to that shown by the longest fusion construct (HsfA1), containing 464 bp of upstream sequence. In contrast, the HsfA4-GUS fusion, containing only 20 bp 5' of the -24/-12 region, showed no GUS activity, delimiting the location of a putative UAS to a 40-bp region. During nodule development, GUS expression first appeared in nodules 12 days postinoculation (dpi) and reached a maximum level of expression in approximately 17-day-old nodules. By 28 dpi, HsfA-GUS expression had returned to a low, basal level. These data were consistent with the detection of hsfA mRNA by in situ hybridization in 17-day-old nodules, but not in 28-day-old nodules. In contrast to the stage-specific expression in cowpea, HsfA-GUS expression increased with nodule development in HsfA3-inoculated soybean. These data indicate that HsfA expression is regulated in cowpea in a unique developmental manner and that the DNA regulatory regions that control this expression are confined to a short, promoter-proximal region.

Development of a structural equation model for causal relationships among arteriosclerosis risk factors

The purpose of this study was to clarify the dynamic causal relationships among arteriosclerotic risk factors, including age, smoking, alcoholic consumption, exercise, hypercholesterolemia, hypertriglyceridemia, and hypertension. Data were collected from the medical records of 400 male clients who visited a university hospital located in Inchon, Korea, from May 1996 to December 1996 for physical examinations. The Lineal Structural Relationships 8 program was used to verify the fitness of the hypothetical model to data. All of the fit statistics, except the Chi-square value, showed that the hypothetical model was well fitted to the data. Seven percent of obesity was explained by the variables of age, smoking, alcohol consumption, and exercise. Sixty percent of hyperlipidemia could be explained by the variables of age, smoking, exercise, and obesity. And 22% of hypertension was explained by the variables of age, smoking, alcohol consumption, exercise, and hyperlipidemia. Our results showed that these risk factors were directly and indirectly interrelated, and lifestyle variables (smoking, alcohol consumption, and exercise) influence almost all of arteriosclerotic risk factors.

The compound relationship of smoking and alcohol consumption with obesity

The purpose of this study was to examine 1) whether the relationship between smoking and obesity was linear or non-linear (specifically U-shaped), and 2) if this relationship was proved to U-shaped, whether it was due to the interaction of the effects of smoking and alcohol consumption on obesity. The present study was performed using cross sectional data taken from the medical records of 400 male patients. Data was analyzed using linear and curvilinear estimation, Fisher's exact test, and two-way ANCOVA. The relationship between smoking intensity and BMI was able to be explained significantly by a quadratic model, rather than by linear model. As has been shown in other studies, this relationship was parabolic (or U-shaped), though it was not particularly remarkable. This U-shaped relationship appeared to be due to the interaction of the effects of smoking intensity and alcohol consumption on BMI. On the other hand, the relationship between smoking intensity and the percentage of body fat was able to be explained significantly by a linear as well as a quadratic model. Additionally, the interaction effect between smoking intensity and alcohol consumption did not influence the percentage of body fat significantly. In conclusion, there is no doubt that smoking and obesity are both serious health hazards. Based on the results of this and other studies, it can be confirmed that heavy smoking has a positive relationship with obesity. Therefore, the health benefits of smoking cessation, as well as the correction of unhealthy habits such as alcohol consumption should be clearly emphasized.

Prenatal development of the human mandible

In an effort to better understand the interrelationship of the growth and development pattern of the mandible and condyle, a sequential growth pattern of human mandibles in 38 embryos and 111 fetuses were examined by serial histological sections and soft X-ray views. The basic growth pattern of the mandibular body and condyle appeared in week 7 of fertilization. Histologically, the embryonal mandible originated from primary intramembranous ossification in the fibrous mesenchymal tissue around the Meckel cartilage. From this initial ossification, the ramifying trabecular bones developed forward, backward and upward, to form the symphysis, mandibular body, and coronoid process, respectively. We named this initial ossification site of embryonal mandible as the mandibular primary growth center (MdPGC). During week 8 of fertilization, the trabecular bone of the mandibular body grew rapidly to form muscular attachments to the masseter, temporalis, and pterygoid muscles. The mandible was then rapidly separated from the Meckel cartilage and formed a condyle blastema at the posterior end of linear mandibular trabeculae. The condyle blastema, attached to the upper part of pterygoid muscle, grew backward and upward and concurrent endochondral ossification resulted in the formation of the condyle. From week 14 of fertilization, the growth of conical structure of condyle became apparent on histological and radiological examinations. The mandibular body showed a conspicuous radiating trabecular growth pattern centered at the MdPGC, located around the apical area of deciduous first molar. The condyle growth showed characteristic conical structure and abundant hematopoietic tissue in the marrow. The growth of the proximal end of condyle was also approximated to the MdPGC on radiograms. Taken together, we hypothesized that the MdPGC has an important morphogenetic affect for the development of the human mandible, providing a growth center for the trabecular bone of mandibular body and also indicating the initial growth of endochondral ossification of the condyle.

Structure and expression of the Arabidopsis thaliana homeobox gene Athb-12

We have isolated the Arabidopsis thaliana homeobox gene Athb-12, determined its structure and activation domain, demonstrated that its promoter is inducible in response to abscisic acid (ABA) treatment, and characterized the cellular distribution of its transcripts. The single intron of the gene interrupted the leucine-zipper domain region. The 5' regulatory region of Athb-12 can drive beta-glucuronidase (GUS) expression in tobacco transgenic plants. Athb-12 gene expression was further examined using in situ hybridization to determine the cellular distribution of Athb-12 transcripts during ABA induction. A complex pattern of Athb-12 expression was observed, often associated with regions of developing vascular tissues. Analysis of chimeras constructed from Athb-12 and the DNA-binding domain of the Saccharomyces cerevisiae transcription factor GAL4 revealed that the activation domain of Athb-12 lies in the C-terminal region (amino acids 180 to 235). Taken together, our data suggest that Athb-12 is a transcriptional activator important in regulating certain developmental processes as well as in the plant's response to water stress involving ABA-mediated gene expression.

In vivo evaluation of polymeric micellar paclitaxel formulation: toxicity and efficacy

Although the current clinical formulation of paclitaxel (Taxol) has a promising clinical activity against a wide variety of tumors, it has significant toxic side effects, some of which are associated with its formulation in a 1:1 (v/v) mixture of Cremophor EL and dehydrated alcohol. One of the problems associated with the intravenous administration of paclitaxel is its low solubility in water. Our study was designed to evaluate the pharmacokinetics, tissue distribution, toxicity and efficacy of a paclitaxel (Genexol)-containing biodegradable polymeric micellar system (Genexol-PM) in comparison to Taxol. Genexol-PM was newly developed by using a low molecular weight, nontoxic and biodegradable amphiphilic diblock copolymer, monomethoxy poly(ethylene glycol)-block-poly(D,L-lactide) (mPEG-PDLLA) and paclitaxel (Genexol, Samyang Genex Co., Seoul, Korea). In a human cancer cell line model, Genexol-PM and Taxol showed comparable in vitro cytotoxicity against human ovarian cancer cell line OVCAR-3 and human breast cancer cell line MCF7. The maximum tolerated dose (MTD) of Genexol-PM and Taxol in nude mice was determined to be 60 and 20 mg/kg, respectively. The median lethal dose (LD(50)) in Sprague--Dawley rats was 205.4 mg/kg (male) and 221.6 mg/kg (female) for Genexol-PM, while 8.3 mg/kg (male) and 8.8 mg/kg (female) for Taxol. After intravenous administration of Genexol-PM in murine B16 melanoma-induced female SPF C57BL/6 mice at a dose of 50 mg/kg, the area under the plasma concentration-time curve (AUC) was similar to Taxol((R)) at a dose of 20 mg/kg, but biodistribution of paclitaxel after administration of Genexol-PM showed 2 to 3-fold higher levels in tissues including liver, spleen, kidneys, lungs, heart and tumor as compared to Taxol. The in vivo antitumor efficacy of Genexol-PM as measured by reduction in tumor volume of SKOV-3 human ovarian cancer implanted in nude (nu/nu) athymic mice and MX-1 human breast cancer implanted in Tac:Cr:(NCr)-nu athymic mice was significantly greater than that of Taxol. The results of cytotoxicity, MTD, LD(50) and antitumor efficacy suggest that Genexol-PM may have a great advantage over present-day chemotherapy with Taxol.

Meteorological effects on the evolution of high ozone episodes in the greater Seoul area

Three high O3 episodes--7 days in 1992 (July 3-July 9), 9 days in 1994 (July 21-July 29), and another 3 days in 1994 (August 22-August 24)--were selected on the basis of morning (7:00 a.m.-10:00 a.m.) average wind direction and speed and daily maximum O3 concentrations in the greater Seoul, Korea, of 1990-1997. To better understand their characteristics and life cycles, surface data from the Seoul Weather Station (SWS) and surface and 850-hPa wind field data covering northeast Asia around the Korean Peninsula were used for the analysis. In the July 1992 episode, westerly winds were most frequent as a result of the influence of a high-pressure system west of the Korean Peninsula behind a trough. In contrast, in the July 1994 episode, easterly winds were most frequent as a result of the effect of a typhoon moving north from the south of Japan. Despite different prevailing wind directions, the peak O3 concentrations for each episode occurred when a sea/land breeze developed in association with weak synoptic forcing. The August 1994 episode, which was selected as being representative of calm conditions, was another typical example in which a well-developed

Multicenter surveillance study for nosocomial infections in major hospitals in Korea. Nosocomial Infection Surveillance Committee of the Korean Society for Nosocomial Infection Control

BACKGROUND

The goals of a surveillance for nosocomial infections (NIs) are to observe the magnitude and characteristics of NIs and to plan and evaluate policies and guidelines of infection control. This study was designed to determine the rate and distribution of NIs and their causative pathogens in Korean hospitals.

METHODS

Prospective surveillance was performed at 15 acute care hospitals with more than 500 beds during a 3-month period from June to August 1996. The case-finding methods were laboratory-based surveillance for patients in the general wards and a direct review of medical charts done regularly for all the patients in the intensive care units.

RESULTS

A total of 3162 NIs were found among 85,547 discharged patients, with an overall nosocomial infection rate of 3.70 per 100 patients discharged. Urinary tract infections constituted 30.3% of all NIs. Other infections were pneumonias, 17.2%, surgical site infections, 15.5%, and primary bloodstream infections, 14.5%. The infection rate was the highest in neurosurgery (14.21), followed by neurology (8. 62) and ontology services (6.70). The infection rate in intensive care units was higher than it was in the general wards (10.74 vs 2. 57, P =.001). The commonly isolated organisms were Staphylococcus aureus (17.2%), Pseudomonas aeruginosa (13.8%), and Escherichia coli (12.3%).

CONCLUSIONS

This first multicenter surveillance study provided extensive information on the current status and trends of NIs in major hospitals in Korea. The results may contribute to the evaluation of infection control programs and the development of effective strategies in these hospitals.

A Target-Site-Specific Screening System for Antifungal Compounds on Appressorium Formation in Magnaporthe grisea

ABSTRACT Chemical fungicides are a major method of control for plant diseases in spite of potential negative effects on the environment and the appearance of resistant strains. Development of new chemical fungicides has been largely dependent upon in vivo efficacy tests in the greenhouse or in fields, which is in contrast to target-oriented in vitro screening systems widely used in the pharmaceutical field. To establish a target-site-specific screening system for antifungal compounds, specific inhibition on appressorium formation of the rice blast fungus Magnaporthe grisea was employed. For many plant-pathogenic fungi, including M. grisea, appressorium formation is an essential step to infect host plants. Among 1,000 culture filtrates of members of the class Actinomycetes and fungi, five (A5005, A5008, A5314, A5387, and A5397) from the class Actinomycetes showed differential inhibitory effects on appressorium formation of M. grisea in a dosage-dependent manner. Three (A5005, A5314, and A5387) of these were further fractionated into ethyl acetate and water fractions. The ethyl acetate fraction of A5005 and both the ethyl acetate and water fractions from A5314 and A5387 inhibited appressorium formation, while conidial germination remained little affected. Inhibition of appressorium formation by the ethyl acetate or water fraction was reversed by the exogenous addition of cyclic AMP. Significantly reduced numbers of conidia with appressoria were observed on rice leaves in the presence of culture filtrates. Furthermore, these culture filtrates also exhibited significant disease control of rice blast in the greenhouse. This rapid and target-oriented screening system could be adopted to screen candidate compounds for rice blast control and could be applicable for other appressorium-forming, plant-pathogenic fungi.

Inter-relationships between arteriosclerotic risk factors: a meta-analysis

This study was performed to clarify the overall inter-relationships between the arteriosclerotic risk factors, including smoking, alcoholic consumption, obesity, serum cholesterol and triglyceride levels, high density lipoprotein, and systolic and diastolic blood pressure using a meta analysis method. The subjects of this study were included in 24 primary studies reported in Korea since 1980, which concerned arteriosclerotic risk factors. The results show that smoking is significantly associated with total cholesterol (R = .04), triglyceride (R = .10) and HDL-cholesterol (R = -.06). Alcohol consumption is also significantly and positively associated with all three serum lipid parameters: cholesterol (R = .04), triglyceride (R = .08) and HDL-cholesterol (R = .10). The effect of smoking and alcohol consumption on cholesterol levels were found to be almost equal. However, smoking has a predominant effect on triglyceride, whereas, alcohol consumption exerts an influence primarily on the HDL-cholesterol level. Obesity was positively correlated with cholesterol (R = .25) and triglyceride (R = .21), however, it was negatively correlated with HDL-cholesterol (R = -.14). It appears that the serum lipid parameter, which shows strongest correlation with obesity, is the total cholesterol level. Obesity also showed a significant correlation with systolic (R = .19) and diastolic blood pressure (R = .13). Blood pressure was also positively correlated with cholesterol (R = .18) and triglyceride (R = .26), however, it correlated negatively with HDL-cholesterol (R = -.23). In conclusion, the overall inter-relationships between the arteriosclerotic risk factors; smoking, alcohol consumption, obesity, serum lipid level and blood pressure were all found to be significant.

Myelomatous effusion with poor response to chemotherapy

While pleural effusion in multiple myeloma is relatively infrequent, myelomatous pleural effusion is extremely rare. We experienced a 61-year-old woman with IgD-lambda multiple myeloma and pleural effusion. The diagnosis was made originally by pleural biopsy, pleural fluid cytology and immunoelectropheresis of pleural fluid. Transient improvement of the pleural effusion was observed after administration of combination chemotherapy of vincristine, melphalan, cyclophosphamide, prednisone (VMCP)/vincristine, cyclophosphamide, adriamycin, prednisone (VCAP). Two months later, myelomatous pleural effusion recurred and no response to salvage therapy was observed. We reviewed the clinical feature of this case and literature concerning myelomatous pleural effusion.

Role of hsfA gene on host-specificity by Bradyrhizobium japonicum in a broad range of tropical legumes

Bradyrhizobium japonicum mutant strain NAD163, containing a 30-kb deletion mutant encompassing the hsfA gene, was inoculated onto a broad range of legume species to test host-specificity. Most legume species formed ineffective nodules except Vigna angularis var. Chibopat and Glycine max var. Pureunkong. A hsfA insertion mutant, BjjC211, gave similar results to strain NAD163, implying that many legume species require HsfA for host-specific nitrogen fixation. To determine whether other genes in the deleted region of NAD163 are also necessary, the hsfA gene was conjugally transferred into the NAD163 mutant. The transconjugant formed effective nodules on the host legume plants, which earlier had formed ineffective nodules with mutant NAD163. Thus, we conclude that the hsfA gene in the 30-kb region is the only factor responsible for host-specific nitrogen fixation in legume plants.

Effects of 17-beta-estradiol and ICI 182 780 on hair growth in various strains of mice

17-beta-Estradiol (10 nmol per 200 microl acetone) applied topically twice weekly to the clipped dorsal surface of C57BL/6 or C3H female mouse skin prevented hair growth, as previously described in the CD-1 mouse strain. Twice weekly topical application of the estrogen receptor antagonist, ICI 182 780 (10nmol per 200microl acetone), induced the telogenanagen transition and produced early pigmentation appearance in skin and hair growth in C57BL/6 and C3H female mice. Whereas twice weekly topical application of 10nmol 17-beta-estradiol blocked hair growth, the intraperitoneal administration of this dose twice weekly did not block hair growth, suggesting a direct cutaneous effect of 17-beta-estradiol. We also evaluated the effect of 17-alpha-estradiol, 17-beta-estradiol, and ICI 182 780 on hair growth in male mice. As observed in female mice, 17-beta-estradiol was a potent inhibitor of hair growth and ICI 182 780 stimulated hair growth; however, unlike the results previously observed in female mice, 17-alpha-estradiol was a potent inhibitor of hair growth in male mice. These results demonstrate that (i) the route of administration of 17-beta-estradiol is critical for its ability to block hair growth; (ii) C57BL/6 and C3H mice, two commonly employed mouse strains for hair growth studies, responded to 17-beta-estradiol and ICI 182 780 in a manner similar to that described in CD-1 mice; and (iii) the hair follicles of male and female mice respond similarly to 17-beta-estradiol and ICI 182 780, but display striking sex differences in the response to 17-alpha-estradiol on hair growth.

C/EBPbeta modulates the early events of keratinocyte differentiation involving growth arrest and keratin 1 and keratin 10 expression

The epidermis is a stratified squamous epithelium composed primarily of keratinocytes that become postmitotic and undergo sequential changes in gene expression during terminal differentiation. The expression of the transcription factor CCAAT/enhancer binding protein beta (C/EBPbeta) within mouse epidermis and primary keratinocytes has recently been described; however, the function of C/EBPbeta within the epidermal keratinocyte is unknown. We report here that transient transfection of mouse primary keratinocytes with a C/EBP-responsive promoter-reporter construct resulted in a sevenfold increase in luciferase activity when keratinocytes were switched to culture conditions that induce growth arrest and differentiation. Forced expression of C/EBPbeta in BALB/MK2 keratinocytes inhibited growth, induced morphological changes consistent with a more differentiated phenotype, and upregulated two early markers of differentiation, keratin 1 (K1) and keratin 10 (K10) but had a minimal effect on the expression of late-stage markers, loricrin and involucrin. Analysis of the epidermis of C/EBPbeta-deficient mice revealed a mild epidermal hyperplasia and decreased expression of K1 and K10 but not of involucrin and loricrin. C/EBPbeta-deficient primary keratinocytes were partially resistant to calcium-induced growth arrest. Analysis of terminally differentiated spontaneously detached keratinocytes or those induced to differentiate by suspension culture revealed that C/EBPbeta-deficient keratinocytes displayed striking decreases in K1 and K10, while expression of later-stage markers was only minimally altered. Our results demonstrate that C/EBPbeta plays an important role in the early events of stratified squamous differentiation in keratinocytes involving growth arrest and K1 and K10 expression.

Epidemiological typing of methicillin-resistant Staphylococcus aureus outbreak isolates by pulsed-field gel electrophoresis and antibiogram

Methicillin-resistant Staphylococcus aureus (MRSA) is one of the most common nosocomial pathogens. In April 1997, there were five MRSA-infected patients among 16 patients in the Neonatal Intensive Care Unit (NICU), Seoul National University Hospital, which is a tertiary-care hospital with 1,500 beds. The infections had spread from twin patients with MRSA who had transferred from Hospital C. MRSA was isolated from the axilla of 15 (94%) of the 16 patients, including the two patients with obvious infections. Three (19%) of 16 doctors and nine (30%) of 30 nurses had MRSA colonization of the anterior nares. Six different PFGE patterns (A through F) were identified in the 53 isolates of MRSA tested. Twelve of 13 isolates from infected sites of five patients showed pattern F. Three MRSA strains obtained from hospital C showed closely or possibly related pattern F. MRSA of type F was isolated from three of 16 patients' axilla, and one of 3 doctors' and three of 30 nurses' nasal swabs. The antibiogram code for 12 of 13 MRSA isolates from five infected patients was 66,754. PFGE patterns of these isolates were either F, F1, F2 or Fa. Only one of three strains isolated from clinical specimens of patients in Hospital C showed the antibiogram code 66754, although they were all PFGE types F1 and Fa. In conclusion, the presumptive sources of the outbreak of MRSA infection in NICU were the twin patients transferred from hospital C. Antibiogram correlated reasonably well to the PFGE type. An effective notification system is needed when a MRSA-infected patient is transferred to another hospital to control the spread of the infection.

Expression of CCAAT/enhancer binding proteins (C/EBP) is associated with squamous differentiation in epidermis and isolated primary keratinocytes and is altered in skin neoplasms

The epidermis is a stratified squamous epithelium composed primarily of keratinocytes that undergo sequential changes in gene expression during differentiation. CCAAT/enhancer binding proteins (C/EBP) are members of the bZIP family of DNA binding proteins/transcription factors. Northern analysis demonstrated that C/EBPalpha, C/EBPbeta, and C/EBPdelta mRNA are expressed in mouse epidermis and their mRNA levels were generally greater than those observed in other tissues known to express high levels of C/EBP. Western analysis of isolated epidermal cell nuclei demonstrated the presence of a 42 and 30 kDa C/EBPalpha protein and 35 kDa C/EBPbeta protein. Immunohistochemical localization of C/EBPalpha and C/EBPbeta in intact interfollicular epidermis revealed that C/EBPbeta expression is exclusive to the nuclei of a three-cell cluster of suprabasal keratinocytes that is morphologically consistent with the central column of the epidermal proliferative unit, and that C/EBPalpha is expressed in the nuclei and cytoplasm of suprabasal keratinocytes and weakly expressed in a perinuclear manner in some basal keratinocytes. In squamous cell carcinomas the expression of C/EBPalpha and C/EBPbeta was greatly diminished as both the intensity of nuclear staining and the number of cells expressing C/EBPalpha and C/EBPbeta were reduced. In isolated primary mouse keratinocytes, calcium-induced differentiation was accompanied by specific temporal changes in the expression of C/EBPalpha, C/EBPbeta, and C/EBPdelta mRNA and C/EBPalpha and C/EBPbeta protein. These results implicate a role for the C/EBP family in the regulation of genes involved in or specifically expressed during the process of squamous differentiation in epidermis.

Differential inhibition of aflatoxin B1 oxidation by gestodene action on human liver microsomes

Human cytochrome P450 (P450) 3A is known to be involved in the formation of both aflatoxin B1-exo-8,9-epoxide (exo-epoxidation) and aflatoxin Q1 (3 alpha-hydroxylation). Gestodene, a known inactivator of P450 3A4, inhibited the formation of AFB1 metabolites in a variety of ways depending on the incubation condition. Preincubation of gestodene with human liver microsomes prior to the addition of AFB1 inhibited both exo-epoxidation and 3 alpha-hydroxylation whereas simultaneous incubation of gestodene with AFB1 only inhibited 3 alpha-hydroxylation. These results suggest that two independent substrate binding sites exist in P450 3A4, and AFB1 binds to both of the binding sites. Gestodene selectively binds to one of the binding sites leading to the formation of AFQ1, whereas it does not affect the formation of exo-epoxide via the other binding site.

Changes of the plasma endothelin in adaptation to increased salt intake in rats

OBJECTIVES

Roles for vascular endothelial hormones in body fluid balance have been variously suggested. The present study was aimed at investigating whether the plasma endothelin is altered in responses to acute and chronic perturbations in body fluid balance.

METHODS

Effects of intravenous infusion of MG-nitro-L-arginine methyl ester (L-NAME), a competitive inhibitor of endothelium-derived nitric oxide (NO) synthesis, on urinary excretion, blood pressure and plasma levels of endothelin were examined in rats kept on either normal or high-salt diet for two weeks. The plasma endothelin levels in response to an acute extracellular volume expansion (VE) were also determined in normal and 2-kidney, 1 clip (2K1C) hypertensive rats.

RESULTS

L-NAME (20 and 200 micrograms.kg(-1) per min) elicited diuretic and natriuretic effects in association with increased blood pressure both in normal and high-salt rats. In high-salt rats, however, the urinary response to L-NAME was attenuated and the pressor response was augmented compared with the control. High-salt intake per se caused a small, but significant, increase of the plasma endothelin. L-NAME (200 micrograms(-1) per min) markedly increased the plasma endothelin was also marginally increased following VE, the magnitude of which did not differ between the normal and 2K1C rats.

CONCLUSION

These results suggest that the endothelin system takes part in adaptation to increased salt-intake. Another evidence indicating a negative modulation of NO on the release of endothelin is also provided.

An estrogen receptor pathway regulates the telogen-anagen hair follicle transition and influences epidermal cell proliferation

The hair follicle is a cyclic, self renewing epidermal structure which is thought to be controlled by signals from the dermal papilla, a specialized cluster of mesenchymal cells within the dermis. Topical treatments with 17-beta-estradiol to the clipped dorsal skin of mice arrested hair follicles in telogen and produced a profound and prolonged inhibition of hair growth while treatment with the biologically inactive stereoisomer, 17-alpha-estradiol, did not inhibit hair growth. Topical treatments with ICI 182,780, a pure estrogen receptor antagonist, caused the hair follicles to exit telogen and enter anagen, thereby initiating hair growth. Immunohistochemical staining for the estrogen receptor in skin revealed intense and specific staining of the nuclei of the cells of the dermal papilla. The expression of the estrogen receptor in the dermal papilla was hair cycle-dependent with the highest levels of expression associated with the telogen follicle. 17-beta-Estradiol-treated epidermis demonstrated a similar number of 5-bromo-2'-deoxyuridine (BrdUrd) S-phase cells as the control epidermis above telogen follicles; however, the number of BrdUrd S-phase basal cells in the control epidermis varied according to the phase of the cycle of the underlying hair follicles and ranged from 2.6% above telogen follicles to 7.0% above early anagen follicles. These findings indicate an estrogen receptor pathway within the dermal papilla regulates the telogen-anagen follicle transition and suggest that diffusible factors associated with the anagen follicle influence cell proliferation in the epidermis.

Epidermal protein kinase C-beta 2 is highly sensitive to downregulation and is exclusively expressed in Langerhans cells: downregulation is associated with attenuated contact hypersensitivity

Treatment of mice with multiple topical applications of 12-O-tetradecanoylphorbol-13-acetate (TPA) or diacylglycerol resulted in a preferential decrease in epidermal protein kinase C-beta 2 (PKC-beta 2) compared with PKC-alpha as determined by western analysis. When PKC-alpha was decreased by 40%, PKC-beta 2 could no longer be detected, suggesting that PKC-beta 2 is more sensitive to downregulation, and/or specific epidermal cell types that contain PKC-beta 2 are more sensitive to TPA/diacylglycerol. To address this issue, we isolated Langerhans cells (LCs) from epidermal cell suspensions with immunomagnetic beads and an antibody to the class II major histocompatibility complex. Northern blot analysis revealed a PKC-beta 2 signal in isolated LCs that was 40-fold greater than that observed in unfractionated epidermal cells, and no PKC-beta 2 signal was detected in epidermal cells depleted of LCs, indicating that PKC-beta 2 is expressed exclusively in LCs within the epidermis. Western blot analysis confirmed the presence of PKC-beta 2 in LCs. PKC-beta 2 was highly sensitive to downregulation, because a single application of TPA resulted in a 90% loss of PKC-beta 2 within 6 h without a decrease in the number of LCs. To determine whether the decreased level of PKC-beta 2 within LCs was associated with an alteration in contact hypersensitivity, we treated mice with only a single application of TPA, and 6 hours later mice were sensitized with 2,4-dinitrofluorobenzene on the same dorsal area. Subsequent challenge revealed a 60% decrease in contact hypersensitivity in TPA-treated mice. These data indicate that (i) within the epidermis, PKC-beta 2 is highly sensitive to downregulation and is exclusively expressed in LCs, and (ii) the downregulation of PKC-beta 2 is associated with impaired LC function with respect to contact hypersensitivity.

The effect of eradication of Helicobacter pylori upon the duodenal ulcer recurrence--a 24 month follow-up study

OBJECTIVES

To evaluate the effect of eradication of Helicobacter pylori(H.pylori) in the patients with duodenal ulcer(Du) upon the DU recurrence.

METHODS

This study was performed for 190 patients with DU. Four different methods-microscopy of Gram stained mucosal smear, specific culture, biopsy urease test, histology of H &E staining-were taken for identifying colonization of H. pylori before treatment, and for finding the eradication of H. pylori 4 weeks after completion of therapy in each treatment group (cometidine, omeprazole, colloidal bismuth subcitrate(CBS), CBS and metronidazole double therapy, CBS, metronidazole and amoxicillin triple therapy). To detect DU recurrence, the gastroscopy was performed at 6, 12, 18, and 24 months after therapy.

RESULTS

The eradication rate of the cimetidine group the omeprazole group, and the CBS group were 0%, 7.7%, 0%, respectively, and that of the double therapy group and the triple therapy group were 44.4% and 89.3%, respectively. Seventy three patients who were followed up for 2 years were categorized into two groups according to the eradication of H. pylori. The recurrence rate was 3.2% both in 1 year and 2 years later in the former group-one consisting of 31 patients with H. pylori eradicated, while the recurrence rate was 57.1% in 1 year and 78.6% in 2 years later, in the latter group-the other of 42 patients with H. pylori not eradicated.

CONCLUSION

The eradication of H. pylori in patients with DU reduces the recurrence of DU.