Metabolic changes preceding bladder cancer occurrence among Korean men: a nested case-control study from the KCPS-II cohort

BACKGROUND

Bladder cancer (BLCA) research in Koreans is still lacking, especially in focusing on the prediction of BLCA. The current study aimed to discover metabolic signatures related to BLCA onset and confirm its potential as a biomarker.

METHODS

We designed two nested case-control studies using Korean Cancer Prevention Study (KCPS)-II. Only males aged 35-69 were randomly selected and divided into two sets by recruitment organizations [set 1, BLCA (n = 35) vs. control (n = 35); set 2, BLCA (n = 31) vs. control (n = 31)]. Baseline serum samples were analyzed by non-targeted metabolomics profiling, and OPLS-DA and network analysis were performed. Calculated genetic risk score (GRS) for BLCA from all KCPS participants was utilized for interpreting metabolomics data.

RESULTS

Critical metabolic signatures shown in the BLCA group were dysregulation of lysine metabolism and tryptophan-indole metabolism. Furthermore, the prediction model consisting of metabolites (lysine, tryptophan, indole, indoleacrylic acid, and indoleacetaldehyde) reflecting these metabolic signatures showed mighty BLCA predictive power (AUC: 0.959 [0.929-0.989]). The results of metabolic differences between GRS-high and GRS-low groups in BLCA indicated that the pathogenesis of BLCA is associated with a genetic predisposition. Besides, the predictive ability for BLCA on the model using GRS and five significant metabolites was powerful (AUC: 0.990 [0.980-1.000]).

CONCLUSION

Metabolic signatures shown in the present research may be closely associated with BLCA pathogenesis. Metabolites involved in these could be predictive biomarkers for BLCA. It could be utilized for early diagnosis, prognostic diagnosis, and therapeutic targets for BLCA.

Non-invasive biomarkers for early diagnosis of pancreatic cancer risk: metabolite genomewide association study based on the KCPS-II cohort

BACKGROUND

Pancreatic cancer is a lethal disease with a high mortality rate. The difficulty of early diagnosis is one of its primary causes. Therefore, we aimed to discover non-invasive biomarkers that facilitate the early diagnosis of pancreatic cancer risk.

METHODS

The study subjects were randomly selected from the Korean Cancer Prevention Study-II and matched by age, sex, and blood collection point [pancreatic cancer incidence (n = 128) vs. control (n = 256)]. The baseline serum samples were analyzed by non-targeted metabolomics, and XGBoost was used to select significant metabolites related to pancreatic cancer incidence. Genomewide association study for the selected metabolites discovered valuable single nucleotide polymorphisms (SNPs). Moderation and mediation analysis were conducted to explore the variables related to pancreatic cancer risk.

RESULTS

Eleven discriminant metabolites were selected by applying a cut-off of 4.0 in XGBoost. Five SNP presented significance in metabolite-GWAS (p ≤ 5 × 10-6) and logistic regression analysis. Among them, the pair metabolite of rs2370981, rs55870181, and rs72805402 displayed a different network pattern with clinical/biochemical indicators on comparison with allelic carrier and non-carrier. In addition, we demonstrated the indirect effect of rs59519100 on pancreatic cancer risk mediated by γ-glutamyl tyrosine, which affects the smoking status. The predictive ability for pancreatic cancer on the model using five SNPs and four pair metabolites with the conventional risk factors was the highest (AUC: 0.738 [0.661-0.815]).

CONCLUSIONS

Signatures involving metabolites and SNPs discovered in the present research may be closely associated with the pathogenesis of pancreatic cancer and for use as predictive biomarkers allowing early pancreatic cancer diagnosis and therapy.

Impact of Free Hospital-Provided Rideshare Service on Radiation Therapy Completion Rates: A Matched Cohort Analysis

PURPOSE/OBJECTIVE(S)

Radiation therapy (RT) is generally given in consecutive daily sessions over multiple weeks. This poses challenges for patients who face barriers such as limited access to public or private transportation, limited financial resources, lack of social support, and long distances to healthcare facilities. Delayed or incomplete RT increases risk for worse clinical outcomes. The potential of rideshare service, which uses a private vehicle for hire arranged through a phone-based application or website, to facilitate timely RT is understudied.

MATERIALS/METHODS

Retrospective data was collected on patients who received RT at a single institution from 2017-2022. Patient demographic and treatment characteristics were compared between those who did and did not utilize free hospital-provided rideshare service. RT completion rates were analyzed for a 1:1 matched non-rideshare cohort using optimal matching with the scaled Euclidean distance metric, to balance age, sex, race, performance status, number of fractions prescribed, Area Deprivation Index (ADI), distance to treatment center, year of diagnosis, treatment site, intent, and modality. ADI is a validated composite measure of community-level socioeconomic deprivation.

RESULTS

Of 2,906 patients who underwent RT, 58 utilized free hospital-provided rideshare service. Rideshare utilizers had a lower median age (60 vs 66, p = .02), and were more likely to identify as Black or African American (60 vs 22%, p<.0001) compared to non-rideshare utilizers. Rideshare utilizers also had higher ADI scores (median 9 vs 5, p<.0001), indicating higher socioeconomic disadvantage, and travelled shorter distances for treatment (median 5.0 vs 14.7 miles, p<.0001). More rideshare utilizers underwent RT for curative intent (79 vs 50%, p<.0001), concordant with a higher number of fractions prescribed (median 28 vs 5, p<.0001) as well as longer treatment course duration (median 39 vs 13 days, p<.0001). The most common treatment sites were head and neck (31%) and breast / chest wall (22%) for rideshare utilizers, and pelvis (27%) and brain (21%) for non-rideshare utilizers (p<.0001). Volumetric modulated arc therapy followed by 3D conformal were the most common treatment modalities in both groups. The matched cohort analysis revealed that RT completion rates were significantly higher for rideshare vs non-rideshare utilizers at 96 vs 81% (p = .01) overall, and 98 vs 78% (p = .01) for patients undergoing treatment with curative intent.

CONCLUSION

Even after adjustment for socioeconomic, clinical, and treatment characteristics, utilization of free hospital-provided rideshare service was associated with improved RT completion rates. These findings are notable as the majority of rideshare utilizers come from socioeconomically marginalized communities, and would otherwise be expected to face significant barriers to RT completion.

The Possible Effect of Dietary Fiber Intake on the Metabolic Patterns of Dyslipidemia Subjects: Cross-Sectional Research Using Nontargeted Metabolomics

BACKGROUND

Dyslipidemia is important because of its association with various metabolic complications. Numerous studies have sought to obtain scientific evidence for managing dyslipidemia patients.

OBJECTIVES

This study aims to identify differences in the nutritional traits of dyslipidemia subjects based on metabolite patterns.

METHODS

Dyslipidemia (n = 73) and control (n = 80) subjects were included. Dyslipidemia was defined as triglycerides ≥200 mg/dL, total cholesterol ≥240 mg/dL, low density lipoprotein cholesterol ≥160 mg/dL, high-density lipoprotein cholesterol <40 mg/dL (men) or 50 mg/dL (women), or lipid-lowering medicine use. Nontargeted metabolomics based on ultra-high performance liquid chromatography-mass spectrometry identified plasma metabolites, and K-means clustering was used to reconstitute groups based on the similarity of metabolomic patterns across all subjects. Then, with eXtreme Gradient Boosting, metabolites significantly contributing to the new grouping were selected. Statistical analysis was conducted to analyze traits demonstrating appreciable differences between the groups.

RESULTS

Dyslipidemia subjects were divided into 2 groups based on whether they were (n = 24) or were not (n = 56) in a similar metabolic state as the controls by K-means clustering. The considerable contribution of 4 metabolites (3-hydroxybutyrylcarnitine, 2-octenal, 1,3,5-heptatriene, and 5β-cholanic acid) to this new subset of dyslipidemia was confirmed by eXtreme Gradient Boosting. Furthermore, fiber intake was significantly higher in dyslipidemia subjects whose metabolic state was similar to that of the control than in the dissimilar group (P = 0.002). Moreover, significant correlations were observed between the 4 metabolites and fiber intake. Regression analysis determined that the ideal cutoff for fiber intake was 17.28 g/d.

CONCLUSIONS

Dyslipidemia patients who consume 17.28 g/d or more of dietary fiber may maintain similar metabolic patterns to healthy individuals, with substantial effects on the changes in the concentrations of 4 metabolites. Our findings could be applied to developing dietary guidelines for dyslipidemia patients.

Clinical impact of intravascular ultrasound guidance in patients of ST-segment elevation myocardial infarction undergoing percutaneous coronary intervention with drug eluting stent

Background

There is little data about clinical role of intravascular ultrasound (IVUS)-guided Percutaneous (PCI) in the setting of ST-segment elevation myocardial infarction (STEMI).

Methods

From 2005 to 2018, a total of 8,129 patients who underwent PCI with STEMI were investigated from the Korea Acute Myocardial Infarction Registry-National Institute of Health database. Patients with Non-ST segment elevation myocardial infarction, cardiogenic shock, bare metal stent implantation, thrombolytic treatment, and coronary artery bypass graft surgery were excluded. We categorized patients into two groups based on the treatment strategy: IVUS-guided PCI group (n=1,544), and coronary angiography guidance (CAG)-guided PCI group (n=6,585). The primary endpoint was composite of major adverse cardiovascular (MACE), including, cardiac death, myocardial infarction (MI), repeat target vessel revascularization (TVR) and stent thrombosis (ST).

Results

IVUS-guided PCI was performed in 19% patients (1544/8129). After propensity score matching, there were no statistically difference in the rate of cardiac death (0% in IVUS vs. 0.26% in CAG, p=0.947), MI (2.01% vs. 2.01%, p=0.408), TVR (1.23% vs. 0.91%, p=0.131), ST (0.32% vs. 0.45%, p=0.828) and composite of MACE at 1 year between two groups (2.01% vs. 2.40%, p=0.843). Independent risk factors for MACE were diabetes mellitus and multi-vessel disease, but not IVUS-guided PCI (HR 1.167, 95% CI, 0.896–1.520, p=0.251).

Conclusion

This study suggests that routine usage of IVUS in the setting of STEMI may not be necessary. Large-scaled random study will be needed for further evaluation.

Funding Acknowledgement

Type of funding sources: None.

Non-structural cancellous bone graft and headless compression screw fixation for treatment of scaphoid waist non-union

PURPOSE

Scaphoid fracture commonly occurs around the mid-third of the scaphoid, and non-union of this fracture has several treatment options. The authors performed autologous cancellous bone graft from the iliac crest and headless compression screw fixation for the treatment of Mack-Lichtman type II scaphoid waist non-union. The purpose of this study was to determine whether this procedure was effective in achieving bony union and restoration of alignment.

METHODS

Medical records and radiographs of 30 patients who underwent cancellous bone graft and headless compression screw fixation for non-union of scaphoid waist fracture were retrospectively reviewed. There were 28 men and 2 women, with a mean age of 32.8 years (range: 21-63). The mean time to surgery was 10 months (range: 3-25) and mean follow-up was 37.5 months (range: 15-52). The authors analyzed bony union, lateral intrascaphoid angle, scapholunate angle, radiolunate angle and scaphoid length on radiographs and evaluated the Modified Mayo wrist score (MMWS) as a functional outcome.

RESULTS

Bony union was achieved in all cases. The lateral intrascaphoid angle improved from 40° to 32° (P<0.001). The scapholunate angle also improved from 61° to 56° (P=0.009). The radiolunate angle decreased from 8° to 4° (P=0.048) and scaphoid length increased from 22mm to 26mm (P<0.001) postoperatively. Wrist motion and MMWS improved significantly at last follow-up. However, there were no significant differences between scaphoid deformity correction angle and pre- to post-operative difference in MMWS.

CONCLUSIONS

Non-structural autologous cancellous bone graft from the iliac crest and headless screw fixation provided reliable results and can be one of the effective treatment options for patients with symptomatic Mack-Lichtman type II non-union in the mid-third of the scaphoid.

LEVEL OF EVIDENCE

Level III.

Refractive errors and strabismus in Asian patients with Down syndrome

PURPOSE

The purpose of this study was to investigate the prevalence and patterns of refractive errors and strabismus in Asian patients with Down syndrome, as they relate to age.MethodsA total of 261 Korean patients with Down syndrome were examined between March 1999 and May 2007. Eighty-nine patients were excluded from the study. The remaining 172 patients were divided into four age groups (<3 years, 3-<6 years, 6-<9 years, and >or=9 years). Full ophthalmologic examinations and strabismus assessments were performed. Refractive errors were defined as follows: myopia >or=-1.00 D, hyperopia >or=+1.00 D, astigmatism >or=+/-1.00 D, and anisometropia as a refractive difference between the two eyes >or=1.00 D.

RESULTS

Hyperopia (46.5%) was slightly more common than myopia (40.1%). The prevalence of myopia increased with age, whereas that of hyperopia decreased. Astigmatism was found in 66.8% of patients, and astigmatism >or=2 D was found in 16.8% of patients. Anisometropia was identified in 29.7% of patients, and the incidence of anisometropia correlated significantly with age as well as with astigmatism. Esotropia (22.1%) was twice as common as exotropia (10.5%). The prevalence of esotropia increased with age, but that of exotropia decreased. Fifty patients were found to have nystagmus (29.1%).

CONCLUSIONS

In Asian patients with Down syndrome, esotropia was more common than exotropia and hyperopia was more common than myopia. The prevalence of exotropia and astigmatism was much higher in this study than has been previously reported.

The Antioxidants in Prevention of Cataracts Study: effects of antioxidant supplements on cataract progression in South India

AIM

To determine if antioxidant supplements (beta carotene and vitamins C and E) can decrease the progression of cataract in rural South India.

METHODS

The Antioxidants in Prevention of Cataracts (APC) Study was a 5 year, randomised, triple masked, placebo controlled, field based clinical trial to assess the ability of interventional antioxidant supplements to slow cataract progression. The primary outcome variable was change in nuclear opalescence over time. Secondary outcome variables were cortical and posterior subcapsular opacities and nuclear colour changes; best corrected visual acuity change; myopic shift; and failure of treatment. Annual examinations were performed for each subject by three examiners, in a masked fashion. Multivariate modelling using a general estimating equation was used for analysis of results, correcting for multiple measurements over time.

RESULTS

Initial enrolment was 798 subjects. Treatment groups were comparable at baseline. There was high compliance with follow up and study medications. There was progression in cataracts. There was no significant difference between placebo and active treatment groups for either the primary or secondary outcome variables.

CONCLUSION

Antioxidant supplementation with beta carotene, vitamins C and E did not affect cataract progression in a population with a high prevalence of cataract whose diet is generally deficient in antioxidants.

Functional and biochemical evaluation of platelet aspirin resistance after coronary artery bypass surgery

BACKGROUND

Aspirin inhibits platelet activation and reduces atherothrombotic complications in patients at risk of myocardial infarction and stroke. However, a sufficient inhibition of platelet function by aspirin is not always achieved. The causes of this aspirin resistance are unknown.

METHODS AND RESULTS

Patients undergoing coronary artery bypass grafting (CABG) have a high incidence of aspirin resistance. To evaluate functional and biochemical responses to aspirin, platelet-rich plasma was obtained before and at days 1, 5, and 10 after CABG. Thromboxane formation, aggregation, and alpha-granule secretion were effectively inhibited by 30 or 100 micromol/L aspirin in vitro before CABG, but this inhibition was prevented or attenuated after CABG. Whereas the inhibition of thromboxane formation and aggregation by aspirin in vitro partly recovered at day 10 after CABG, oral aspirin (100 mg/d) remained ineffective. The inducible isoform of cyclooxygenase in platelets, COX-2, has been suggested to confer aspirin resistance. In fact, immunoreactive COX-2 was increased 16-fold in platelets at day 5 after CABG, but the COX-2 selective inhibitor celecoxib did not alter aspirin-resistant thromboxane formation. By contrast, the combined inhibitor of thromboxane synthase and thromboxane receptor antagonist terbogrel equally prevented thromboxane formation of platelets obtained before (control) and after CABG.

CONCLUSIONS

Platelet aspirin resistance involves an impairment of both in vivo and in vitro inhibition of platelet functions and is probably due to a disturbed inhibition of platelet COX-1 by aspirin.

In vitro and in vivo (SCID mice) effects of phytosterols on the growth and dissemination of human prostate cancer PC-3 cells

The dietary effect of phytosterols (PS) versus cholesterol on the growth and metastasis of the PC-3 human prostate cancer cells in SCID mice was studied. Also, their direct effect on the growth and migration of these cells in vitro was analysed. In the in vivo experiment, SCID mice were fed a diet containing 2% of either PS mixture or cholesterol plus 0.2% cholic acid and implanted with 2 x 10(6) tumour cells per mouse. Tumour growth was monitored for 8 weeks post inoculation. Animals fed the PS diet had tumours 40-43% smaller than those fed the cholesterol diet. Furthermore, the number of mice with lymph node and lung metastasis was almost one-half that of the cholesterol-fed group. In the in vitro studies, both beta-sitosterol and campesterol inhibited the growth of PC-3 cells by 70% and 14%, respectively, while cholesterol supplementation increased the growth by 18% when compared with controls. PS inhibited the invasion of PC-3 cells into Matrigel-coated membranes by 78% while cholesterol increased it by 43% as compared with the cells in the control media. Migration of tumour cells through 8 microm pore membranes was reduced by 60-93% when the PC-3 cells were in PS media, as compared with a 67% increase after cholesterol supplementation. PS supplementation reduced the binding of PC-3 cells to laminin by 15-38% and fibronectin by 23% while cholesterol increased binding to type IV collagen by 36%. It was concluded that PS indirectly (in vivo as a dietary supplement) and directly (in tissue culture media) inhibited the growth and metastasis of PC-3 cells. beta-Sitosterol was more effective than campesterol in offering this protection in most of the parameters studied.

Clinical features of vivax malaria

Plasmodium vivax malaria reemerged in the Republic of Korea in 1993 near the Demilitarized Zone (DMZ). We reviewed clinical features of 101 symptomatic patients with vivax malaria. Of the patients, 77 patients (76.3%) were veterans who had served near the DMZ; their median age was 23 years. The duration of the minimum latent period was > 6 months in 66.2% (51 of 77) of the patients (median, 278 days). Tertian fever developed in 69 patients (68.3%). Severe thrombocytopenia with platelet counts < 60,000/microL was common (29.6% of patients). The parasite densities ranged 32-52,127 parasites per microliter of blood (geometric mean, 1,287). The only complication was a splenic rupture in one patient. All patients responded promptly to chloroquine therapy. Our data suggest that the clinical features of reemerging vivax malaria may be similar to those of Korean vivax malaria reported in the past.

A novel fibroblast growth factor receptor-5 preferentially expressed in the pancreas(1)

Using the polymerase chain reaction on human embryonic cDNAs, we isolated a cDNA encoding a novel 504 amino acid protein, termed fibroblast growth factor receptor (FGFR)-5, which is highly homologous to known FGFRs. The NH(2)-terminal portion of FGFR5 contains a putative secretory signal sequence, three typical immunoglobulin-like domains, six cysteines, and an acidic box, but no HAV motif. The COOH-terminal portion of FGFR5 contains one transmembrane domain but no intracellular kinase domain. Recombinant FGFR5 expressed in COS-7 cells is not secreted, but recombinant truncated FGFR5 lacking the predicted transmembrane domain is secreted. Acidic fibroblast growth factor (aFGF) and basic fibroblast growth factor (bFGF) do not bind to FGFR5. Among 23 adult human tissues, FGFR5 mRNA is preferentially expressed in the pancreas. These results suggest that FGFR5 may provide a binding site for some other fibroblast growth factors and may regulate some pancreatic function.

Outcomes-based trial of an inpatient nurse practitioner service for general medical patients

Although teaching hospitals are increasingly using nurse practitioners (NPs) to provide inpatient care, few studies have compared care delivered by NPs and housestaff or the ability of NPs to admit and manage unselected general medical patients. In a Midwest academic teaching hospital 381 patients were randomized to general medical wards staffed either by NPs and a medical director or medical housestaff. Data were obtained from medical records, interviews and hospital databases. Outcomes were compared on both an intention to treat (i.e. wards to which patients were randomized) and actual treatment (i.e. wards to which patients were admitted) basis. At admission, patients assigned randomly to NP-based care (n = 193) and housestaff care (n= 188) were similar with respect to demographics, comorbidity, severity of illness and functional parameters. Outcomes at discharge and at 6 weeks after discharge were similar (P>0.10) in the two groups, including: length of stay; charges; costs; consultations; complications; transfers to intensive care; 30-day mortality; patient assessments of care; and changes in activities of daily living, SF-36 scores and symptom severity. However, after randomization, 90 of 193 patients (47%) assigned to the NP ward were actually admitted to housestaff wards, largely because of attending physicians and NP requests. None the less, outcomes of patients admitted to NP and housestaff wards were similar (P>0.1). NP-based care can be implemented successfully in teaching hospitals and, compared to housestaff care, may be associated with similar costs and clinical and functional outcomes. However, there may be important obstacles to increasing the number of patients cared for by NPs, including physician concerns about NPs' capabilities and NPs' limited flexibility in managing varying numbers of patients and accepting off-hours admissions.

A retrospective study of diagnosis and management of mesenteric vein thrombosis

BACKGROUND

Mesenteric vein thrombosis (MVT) is an uncommon type of intestinal ischemia associated with significant mortality and morbidity because of its delay in diagnosis.

METHODS

A retrospective analysis of 9 patients treated surgically for MVT during 1982 to 1997 was performed.

RESULTS

Nine patients underwent surgical therapy for intestinal ischemia due to MVT. The most common presenting symptom was abdominal pain with bloody diarrhea in 3 patients; preoperative diagnosis of MVT was suspected in 2. Radiologic tests included plain roentgenograms, computed axial tomography, and ultrasound. Time to surgery ranged from 3 hours to 7 days after admission. All patients underwent resection of infarcted bowel with primary anastomosis and immediate postoperative anticoagulation. No patient underwent a second-look operation. The postoperative morbidity and mortality rates were 55% and 11%, respectively.

CONCLUSION

Diagnosis of intestinal ischemia from MVT is often delayed, and strong clinical suspicion and aggressive treatment are necessary in its management.

Genetic analyses of NFKB1 and OCA-B function: defects in B cells, serum IgM level, and antibody responses in Nfkb1-/-Oca-b-/- mice

Defined patterns of gene expression during cell differentiation are likely to be ensured by multiple factors playing redundant roles. By generating mice deficient in both NFKB1 and OCA-B, we show here that the two transcription factors are required for B-1 cell differentiation and serum IgM production. In addition, relative to Nfkb1(-/-) or Oca-b(-/-) mice, the Nfkb1(-/-)Oca-b(-/-) mice show a decrease in conventional B cell frequencies in the spleen and augmented reductions in T-independent and T-dependent Ab responses. These results suggest that NFKB1 and OCA-B play compensatory roles in multiple aspects of B cell differentiation.

The Giardia genome project database

The Giardia genome project database provides an online resource for Giardia lamblia (WB strain, clone C6) genome sequence information. The database includes edited single-pass reads, the results of BLASTX searches, and details of progress towards sequencing the entire 12 million-bp Giardia genome. Pre-sorted BLASTX results can be retrieved based on keyword searches and BLAST searches of the high throughput Giardia data can be initiated from the web site or through NCBI. Descriptions of the genomic DNA libraries, project protocols and summary statistics are also available. Although the Giardia genome project is ongoing, new sequences are made available on a bi-monthly basis to ensure that researchers have access to information that may assist them in the search for genes and their biological function. The current URL of the Giardia genome project database is www.mbl.edu/Giardia.

Role of OCA-B in 3'-IgH enhancer function

OCA-B (alternately called Bob1 and OBF-1) is a B cell-specific coactivator that interacts with the ubiquitously expressed Oct-1 and the B cell-restricted Oct-2 to activate transcription via the octamer site (5'-ATGCAAAT-3'). OCA-B-/- mice appear to undergo normal Ag-independent B cell maturation. However, Ag-dependent B cell differentiation, including germinal center formation, production of secondary Ig isotypes, and proliferation in response to surface Ig cross-linking, is greatly affected. We demonstrate that the observed reductions in expression of class-switched isotypes in OCA-B-/- mice may be due in part to deficiencies in the function of the 3'-IgH enhancer elements. Furthermore, we find that surface Ig cross-linking represses all the Ig enhancers and that this repression is absent in OCA-B-/- B cells. These results suggest an important role for OCA-B in Ig enhancer function in vivo.

The frequency of mutation in CCR5 gene among Koreans

To better understand a role of the delta32 allele of the CCR5 gene in HIV-1 transmission and disease progression, we determined the CCR5 genotypes within several groups of Koreans. Amplification of DNA from each subject was achieved with polymerase chain reaction, using the CCR5 specific primer pair, which flanks the 32 bp deletion. The 1.2 kb coding sequences of CCR5 were examined to see the possible effects of CCR5 polymorphism. All of the 339 healthy, HIV-uninfected individuals had no mutation in the CCR5 gene. All of the 115 HIV-1-infected patients including 11 long-term non-progressors (LTNPs) and 18 discordant spouses were also wild homozygotes. No variation in the 1.2kb CCR5 coding sequence was found in 5 LTNPs and 5 discordant spouses. In conclusion, the 32 bp deletion mutant is rarely present in Koreans. Our data suggest that factors other than the CCR5 coding sequences may also play a role in the resistance to HIV infection.

Respiratory syncytial virus infection induces expression of the anti-apoptosis gene IEX-1L in human respiratory epithelial cells

By means of differential display reverse-transcriptase polymerase chain reaction, increased expression of the mRNA encoding the anti-apoptosis gene IEX-1L was found in respiratory epithelial cells infected with respiratory syncytial virus (RSV). IEX-1L mRNA expression increased 5-7-fold in RSV-infected cells at 72 h after infection but remained unchanged in cells exposed to irradiated, replication-incompetent RSV. Because IEX-1L is reported to protect cells from apoptosis induced by tumor necrosis factor (TNF)-alpha, the effect of TNF-alpha on epithelial cell apoptosis in the context of RSV infection was determined. Epithelial cells were exposed to vehicle, RSV, or irradiated RSV for 72 h, and then TNF-alpha was added to appropriate cultures. Cytochemical staining of cellular DNA with 4,6-diamidino-2-phenylindole demonstrated TNF-alpha-induced apoptosis in 23.4% of control cells but only 5% of RSV-infected cells. These data show that RSV infection protects epithelial cells from TNF-alpha-induced apoptosis and that this effect is temporally associated with IEX-1L gene expression.

Dietary phytosterol inhibits the growth and metastasis of MDA-MB-231 human breast cancer cells grown in SCID mice

The objective of the present study was to investigate the effect of dietary phytosterols on the growth and metastasis of the human breast cancer MDA-MB-231 cell line xenografted in SCID mice. Two groups of animals were fed AIN-93G diet supplemented with 0.2% cholic acid and 2% sterol (cholesterol or phytosterol mixture) for 15 days before inoculation of the tumor into the right inguinal mammary fat pad. Tumor growth and food consumption were recorded weekly throughout the 8 weeks of the experiment. At the end of the experiment, the animals fed phytosterol had a 40% lower serum cholesterol and 20 and 30 fold higher serum beta-sitosterol and campesterol, respectively as compared to those fed cholesterol. There was no difference between the two groups in body weight and food consumption. However, the tumor size in animals fed phytosterols was 33% smaller (P < 0.03) and had 20% fewer metastases to lymph nodes and lungs than the cholesterol group. At termination, the tumor weight of the animals fed the phytosterol diet was also less (P < 0.07) than that of the cholesterol group. It is concluded that dietary phytosterols retard the growth and spread of breast cancer cells.

Intussusception in adults

Intussusception in adults is a rare entity that it is generally caused by definable intraluminal pathology. We report four cases of adult intussusception caused by lymphoma of the terminal ileum (2), an inflamed appendix (1) and a mucosal polyp (1). All presented with a variety of nonspecific and chronic symptoms, including abdominal pain, nausea and vomiting, consistent with partial small bowel obstruction. Only one patient had palpable masses in the abdomen. The most useful diagnostic radiological method was computed tomography (CT), which showed "target" lesions. The presence of the characteristic "target" lesion may obviate the need for further studies, including a barium enema. As in the cases reported here, treatment involves more than simple reduction; surgical resection is usually indicated.

Inhibition of MT-450 rat mammary tumour growth by antibodies recognising subtypes of blood group antigen B

Using subtractive immunization to identify cell surface epitopes expressed in a metastasis-specific fashion on cells of the rat MT-W9 mammary carcinoma model, we generated a monoclonal antibody called M-N#1. This antibody binds specifically to metastasizing cells of the MT-W9 series and also to certain other metastasizing rat mammary carcinoma cell lines. We demonstrate that the M-N#1 antibody recognizes a fucosylated N-glycosyl sugar modification, and furthermore show that the epitope specificity of the M-N#1 antibody is for blood group antigen B subtypes 2, 3 and 4 with slight cross-reactivity with blood group antigen A subtype 2. The expression of these carbohydrate epitopes on MT-450 cells is functionally important, because the M-N#1 antibody efficiently inhibits MT-450 tumour growth in spontaneous metastasis assays. These results suggest that expression of the subtypes of blood group antigen B recognized by the M-N#1 antibody does not directly participate in the metastatic cascade but rather confers a growth or survival advantage on the tumour cells.

AsGM1+ NK cells prevent metastasis of invading LD-MCA-38 tumor cells in the nude mouse

BACKGROUND

Although the liver is a potent tumor cell killing organ it is frequently the site of lethal metastases often signifying the endstage for patients with colorectal cancers. Enhancing hepatic-associated immunity remains elusive until the interactions among hepatic nonparenchymal cells (NPC) are deciphered. We sought to modulate the cellular components of the hepatic immune system of mice with anti-NK and anti-T-cell-neutralizing antibodies in order to determine the cell type most efficacious in preventing liver metastasis.

MATERIALS AND METHODS

Liver-derived murine colon adenocarcinoma (LD-MCA-38) cells were injected into the ileocolic vein (ICV) of immunocompetent and immunodeficient C57BL/6 mice. Mice were pretreated 1 day prior to tumor cell injection with one of three antibodies: anti-AsGM1, Anti-NK1.1, or Anti-Thy1.2. On Day 21 laparotomy was performed to determine the extent of hepatic tumor foci. The number of hepatic tumor foci was recorded and compared by the Wilcoxon rank sum test.

RESULTS

Mice pretreated with anti-AsGM1 or Anti-NK1.1 developed a massive increase in the number of hepatic tumor foci and decreased survival compared to the control treated mice. Pretreatment with anti-Thy1.2 antibody resulted in a significant decrease in the number of hepatic tumor foci. LD-MCA-38 tumor cells were unable to colonize the liver of C57BL/6 athymic nude mice; however, anti-AsGM1 antibody abolished this antimetastatic effect. There was no difference in the extent of hepatic metastasis and survival between immunodeficient C57BL/6 bg/bg and their conventional littermates bg/+.

CONCLUSION

AsGM1+ NK cells exhibit a significant antitumor response in the absence of T-cells. The concept of stimulating NK cell activity and suppressing T-cell function may enhance liver-associated immunity and serve as a deterrent for blood-borne tumor cells metastasizing to the liver.

Barrels and septa: separate circuits in rat barrels field cortex

The neural circuitry within sensory cortex determines its functional properties, and different solutions have evolved for integrating the activity that arises from an array of sensory inputs to cortex. In rodent, circumscribed receptors, such as whiskers, are represented in somatic sensory (S-I) cortex in islands of cells in layer IV called "barrels" surrounded by narrow channels that separate barrels called "septa." These two cortical domains were previously shown to receive sensory inputs through parallel subcortical pathways. Here, by using small biocytin injections, we demonstrate that distinct intrinsic and corticocortical circuitries arise from barrel and septal columns. The intracortical S-I projections originating from barrel columns are rather short-ranged, terminating for the most part within the far boundaries of the most immediate neighboring barrel columns, whereas corticocortical projections reach the second somatosensory (S-II) cortex. In contrast, the intrinsic projections arising from septal columns extend two to three barrels' distance along the row of whisker representation, producing terminals preferentially in other septal columns. Septal corticocortical projections terminate in the dysgranular cortex anterior to E-row barrels and in the posteromedial parietal cortex in addition to S-II. Whereas layer IV barrels are largely isolated from lateral connections, septa are the main conduits of intracortical projections arising from neighboring barrel and septal columns. These results indicate that the two subcortical pathways from whiskers to cortex continue as two distinct partially segregated pathways in cortex.

A cluster of ABA-regulated genes on Arabidopsis thaliana BAC T07M07

Arabidopsis thaliana BAC T07M07 encoding the abscisic acid-insensitive 4 (ABI4) locus has been sequenced completely. It contains a 95,713-bp insert and 24 predicted genes. Most putative genes were confirmed by gel-based RNA profiling and a cluster of ABA-regulated genes was identified. One of the 24 genes, designated PP2C5, encodes a putative protein phosphatase 2C. The encoded protein was expressed in Escherichia coli, and its enzyme activity in vitro was confirmed.

The functional influence of burst and tonic firing mode on synaptic interactions in the thalamus

Thalamocortical and perigeniculate (PGN) neurons can generate action potentials either as Ca2+ spike-mediated high-frequency bursts or as tonic trains. Using dual intracellular recordings in vitro in monosynaptically connected pairs of PGN and dorsal lateral geniculate nucleus (LGNd) neurons, we found that the functional effect of synaptic transmission between these cell types was strongly influenced by the membrane potential and hence the firing mode of both the pre- and postsynaptic neurons. Activation of single action potentials or low-frequency spike trains in PGN or thalamocortical neurons resulted in the generation of PSPs that were 0.5-2.0 mV in amplitude. In contrast, the generation of Ca2+ spike-mediated bursts of action potentials in the presynaptic cell increased these PSPs to an average of 4.4 mV for the IPSP and 3.0 mV for the EPSP barrage, because of temporal summation and/or facilitation. If the postsynaptic neuron was at a resting membrane potential (e.g., -65 mV), these PSP barrages could result in the activation of a low-threshold Ca2+ spike and burst of action potentials. These results demonstrate that the burst firing mode of action potential generation is a particularly effective means by which perigeniculate and thalamocortical neurons may influence one another. We propose that the activation of burst discharges in these cell types is essential for the generation of some forms of synchronized rhythmic oscillations of sleep and of epileptic seizures.

Functional and ionic properties of a slow afterhyperpolarization in ferret perigeniculate neurons in vitro

Intracellular recordings from spontaneously spindling GABAergic neurons of the ferret perigeniculate nucleus in vitro revealed a fast afterhyperpolarization after each action potential, a medium-duration afterhyperpolarization after each low-threshold Ca2+ spike, and a slow afterhyperpolarization after the cessation of spindle waves. The slow afterhyperpolarization was associated with an increase in membrane conductance, and the reversal potential was sensitive to extracellular [K+]o, indicating that it is mediated at least in part by the activation of a K+ conductance. However, the block of Ca2+ channels did not block the slow afterhyperpolarization, whereas the block of Na+ channels did block this event, even after the generation of repetitive Ca2+ spikes, indicating that it is mediated by a Na+-activated K+ current. Application of apamin reduced the afterhyperpolarization and enhanced a plateau potential after each low-threshold Ca2+ spike. This plateau potential could result in a prolonged depolarization of perigeniculate neurons, even before the application of apamin, resulting in the generation of tonic discharge. The plateau potential was blocked by the local application of tetrodotoxin, indicating that it is mediated by a persistent Na+ current. The activation and interaction of these slowly developing and persistent currents contributes significantly to low-frequency components of spindle wave generation. In particular, we suggest that the activation of the slow afterhyperpolarization may contribute to the generation of the spindle wave refractory period in vitro.

Pneumatosis intestinalis and portal vein gas after blunt abdominal trauma

The authors report on a 2-year-old boy in whom pneumatosis intestinalis (PI) and portal vein gas (PVG) resulted from blunt abdominal trauma after child abuse. The presumed pathophysiology of PI and PVG is mechanical in this setting. Its presence establishes mucosal injury but does not necessarily imply intestinal necrosis.

Functional dynamics of GABAergic inhibition in the thalamus

The inhibitory gamma-aminobutyric acid-containing (GABAergic) neurons of the thalamic reticular and perigeniculate nuclei are involved in the generation of normal and abnormal synchronized activity in thalamocortical networks. An important factor controlling the generation of activity in this system is the amplitude and duration of inhibitory postsynaptic potentials (IPSPs) in thalamocortical cells, which depend on the pattern of activity generated in thalamic reticular and perigeniculate cells. Activation of single ferret perigeniculate neurons generated three distinct patterns of GABAergic IPSPs in thalamocortical neurons of the dorsal lateral geniculate nucleus: Low-frequency tonic discharge resulted in small-amplitude IPSPs mediated by GABAA receptors, burst firing resulted in large-amplitude GABAA IPSPs, and prolonged burst firing activated IPSPs mediated by GABAA and GABAB receptors. These functional properties of GABAergic inhibition can reconfigure the operations of thalamocortical networks into patterns of activity associated with waking, slow-wave sleep, and generalized seizures.

The B-cell-specific transcription coactivator OCA-B/OBF-1/Bob-1 is essential for normal production of immunoglobulin isotypes

OCA-B was initially identified as a B-cell-restricted coactivator that functions with octamer binding transcription factors (Oct-1 and Oct-2) to mediate efficient cell type-specific transcription of immunoglobulin promoters in vitro. Subsequent cloning studies led to identification of the coactivator as a single polypeptide, designated either as OCA-B (ref. 3), OBF-1 (ref. 4) or Bob-1 (ref. 5). OCA-B itself does not bind to DNA directly, but interacts with either Oct-1 or Oct-2 to potentiate transcriptional activation. To determine the biological role of OCA-B, we generated OCA-B-deficient mice by gene targeting. Mice lacking OCA-B undergo normal antigen-independent, B-cell differentiation, including appropriate expression of both immunoglobulin genes and other early B-cell-restricted genes. However, antigen-dependent maturation of B cells is greatly affected. The proliferative response to surface IgM crosslinking is impaired, and there is a severe deficiency in the production of secondary immunoglobulin isotypes including IgG1, IgG2a, IgG2b, IgG3, IgA and IgE in OCA-B-deficient B cells. This defect is not due to a failure of the isotype switching process, but rather to reduced levels of transcription from normally switched immunoglobulin heavy-chain loci. In accord with the defective isotype production, germinal centre formation is absent in these mutant mice.

Are the interlaminar zones of the ferret dorsal lateral geniculate nucleus actually part of the perigeniculate nucleus?

The ferret dorsal lateral geniculate nucleus (LGNd) contains interneurons within the interlaminar zones situated between the laminae corresponding to the ipsi- and contralateral eyes. We found that a subset of these neurons exhibits electrophysiological properties similar to those previously reported for perigeniculate (PGN) neurons, including the generation of rhythmic sequences of rebound low-threshold Ca2+ spikes at a frequency of 1-4 Hz after the intracellular injection of a hyperpolarizing current pulse. These "PGN-like" interlaminar interneurons innervated restricted regions of the A-laminae, inhibited thalamocortical cells through GABAA, and perhaps GABAB, receptors, and were excited by axon collaterals from thalamocortical cells. This reciprocal relationship is identical to that formed by PGN cells and allowed the PGN-like interlaminar neurons to participate in the generation of spindle waves and other network oscillations. Pharmacologically, PGN-like interlaminar interneurons were also similar to PGN neurons: both generated a prolonged depolarization in response to the local application of serotonin, 1S,3R-ACPD, and CCK8S, and a rapid depolarization followed by a more prolonged hyperpolarization in response to acetylcholine. Examination of parvalbumin and calbindin staining in the ferret LGNd revealed that both PGN and a subset of interlaminar neurons were parvalbumin-positive. In contrast, calbindin-positive cells were relatively absent in the PGN and sparsely present in the interlaminar zones, but were numerous in the A and C laminae. Our results indicate that the interlaminar zone in between laminae A and A1 and A1 and C in the ferret LGNd possesses a cell type that is electrophysiologically, pharmacologically, anatomically, immunocytochemically, and functionally similar to neurons in the PGN.

Clinically occult carotid injury: a case for operative management

A case is described of a clinically occult carotid artery lesion secondary to penetrating trauma. Angiography displayed a small intimal defect, whereas surgical exploration revealed significant intimal damage requiring excision and interposition grafting. This case supports the benefit of continued definitive operative management for carotid artery injuries.

Culture, gender, and self: a perspective from individualism-collectivism research

Individualism and collectivism are often equated with independent vs. interdependent, agentic vs. communal, and separate vs. relational self-construals. Although these same concepts have been used to characterize both cultural and gender differences, a perspective of cultural evolution suggests it is unlikely. A division of labor within society may produce gender differences, but this cannot explain cultural differences. A study of self-construal involving 5 cultures (Australia, the United States, Hawaii, Japan, and Korea) shows that differences between these cultures are captured mostly by the extent to which people see themselves as acting as independent agents, whereas gender differences are best summarized by the extent to which people regard themselves as emotionally related to others.