Prognostic utility of self-reported sarcopenia (SARC-F) in the Multiethnic Cohort

BACKGROUND

Age-related loss in skeletal muscle mass, quality, and strength, known as sarcopenia, is a well-known phenomenon of aging and is determined clinically using methods such as dual-energy X-ray absorptiometry (DXA). However, these clinical methods to measure sarcopenia are not practical for population-based studies, and a five-question screening tool known as SARC-F has been validated to screen for sarcopenia.

METHODS

We investigated the relationship between appendicular skeletal lean mass/height² (ALM/HT² ) (kg/m² ) assessed by DXA and SARC-F in a subset of 1538 (778 men and 760 women) participants in the Multiethnic Cohort (MEC) Study after adjustment for race/ethnicity, age, and body mass index (BMI) at the time of DXA measurement. We then investigated the association between SARC-F and mortality among 71 283 (41 757 women and 29 526 men) participants in the MEC, who responded to the five SARC-F questions on a mailed questionnaire as part of the MEC follow-up in 2012-2016.

RESULTS

In women, SARC-F score was significantly inversely associated with ALM/HT² after adjusting for race/ethnicity, and age and BMI at DXA (r = -0.167, P < 0.001); the result was similar in men although it did not reach statistical significance (r = -0.056, P = 0.12). Among the 71 000+ MEC participants, SARC-F score ≥ 4, as an indicator of sarcopenia, was higher in women (20.9%) than in men (11.2%) (P < 0.0001) and increased steadily with increasing age (6.3% in <70 vs. 41.3% in 90+ years old) (P < 0.0001). SARC-F score ≥ 4 was highest among Latinos (30.8% in women and 16.1% in men) and lowest in Native Hawaiian women (15.6%) and Japanese American men (8.9%). During an average of 6.8 years of follow-up, compared with men with SARC-F score of 0-1 (indicator of no sarcopenia), men with SARC-F 2-3 (indicator of pre-sarcopenia) and SARC-F ≥ 4 had significantly increased risk of all-cause mortality [hazard ratio (HR) = 1.00, 1.77, 3.73, P < 0.001], cardiovascular disease (CVD) mortality (HR = 1.00, 1.85, 3.98, P < 0.001), and cancer mortality (HR = 1.00, 1.46, 1.96, P < 0.001) after covariate adjustment. Comparable risk association patterns with SARC-F scores were observed in women (all-cause mortality: HR = 1.00, 1.47, 3.10, P < 0.001; CVD mortality: HR = 1.00, 1.59, 3.54, P < 0.001; cancer mortality: HR = 1.00, 1.30, 1.77, P < 0.001). These significant risk patterns between SARC-F and all-cause mortality were found across all sex-race/ethnic groups considered (12 in total).

CONCLUSIONS

An indicator of sarcopenia, determined using SARC-F, showed internal validity against DXA and displayed racial/ethnic and sex differences in distribution. SARC-F was associated with all-cause mortality as well as cause-specific mortality.

High-quality thulium iron garnet films with tunable perpendicular magnetic anisotropy by off-axis sputtering - correlation between magnetic properties and film strain

Thulium iron garnet (TmIG) films with perpendicular magnetic anisotropy (PMA) were grown on gadolinium gallium garnet (GGG) (111) substrates by off-axis sputtering. High-resolution synchrotron radiation X-ray diffraction studies and spherical aberration-corrected scanning transmission electron microscope (Cs-corrected STEM) images showed the excellent crystallinity of the films and their sharp interface with GGG. Damping constant of TmIG thin film was determined to be 0.0133 by frequency-dependent ferromagnetic resonance (FMR) measurements. The saturation magnetization (Ms) and the coercive field (Hc) were obtained systematically as a function of the longitudinal distance (L) between the sputtering target and the substrate. A 170% enhancement of PMA field (H⊥) was achieved by tuning the film composition to increase the tensile strain. Moreover, current-induced magnetization switching on a Pt/TmIG structure was demonstrated with an ultra-low critical current density (jc) of 2.5 × 106 A/cm2, an order of magnitude smaller than the previously reported value. We were able to tune Ms, Hc and H⊥ to obtain an ultra-low jc of switching the magnetization, showing the great potential of sputtered TmIG films for spintronics.

Strongly exchange-coupled and surface-state-modulated magnetization dynamics in Bi2Se3/yttrium iron garnet heterostructures

Harnessing the spin–momentum locking of topological surface states in conjunction with magnetic materials is the first step to realize novel topological insulator-based devices. Here, we report strong interfacial coupling in Bi₂Se₃/yttrium iron garnet (YIG) bilayers manifested as large interfacial in-plane magnetic anisotropy (IMA) and enhancement of damping probed by ferromagnetic resonance. The interfacial IMA and damping enhancement reaches a maximum when the Bi₂Se₃ film approaches its two-dimensional limit, indicating that topological surface states play an important role in the magnetization dynamics of YIG. Temperature-dependent ferromagnetic resonance of Bi₂Se₃/YIG reveals signatures of the magnetic proximity effect of T_C as high as 180 K, an emerging low-temperature perpendicular magnetic anisotropy competing the high-temperature IMA, and an increasing exchange effective field of YIG steadily increasing toward low temperature. Our study sheds light on the effects of topological insulators on magnetization dynamics, essential for the development of topological insulator-based spintronic devices.

Understanding the effects of topological insulators on magnetization dynamics of adjacent magnetic materials is essential for novel spintronic devices. Here, Fanchiang et al. report thickness dependence of interfacial in-plane magnetic anisotropy and damping enhancement in Bi₂Se₃/yttrium iron garnet (YIG) bilayers, indicating an important role of topological surface states in the magnetization dynamics of YIG.

The complex interplay among bacterial motility and virulence factors in different Escherichia coli infections

Motility mediated by the flagella of Escherichia coli is important for the bacteria to move toward host cells. Here, we present the relationship among bacterial motility, virulence factors, antimicrobial susceptibility, and types of infection. A total of 231 clinical E. coli isolates from different infections were collected and analyzed. Higher-motility strains (motility diameter ≥6.6 mm) were more common in spontaneous bacterial peritonitis (SBP) (SBP 59 %, colonization 32 %, urinary tract infection 16 %, urosepsis 34 %, and biliary tract infection 29 %; p < 0.0001). Compared with the higher-motility group, there was a higher prevalence of afa and ompT genes (p = 0.0160 and p = 0.0497, respectively) in E. coli strains with lower motility. E. coli isolates with higher and lower motility were in different phylogenetic groups (p = 0.018), with a lower prevalence of A and B1 subgroups in higher-motility strains. Also, the patterns of virulence factors and antibiotic susceptibility of E. coli isolates derived from various infections were significantly different. This study demonstrates that the prevalence of higher-motility strains was greater in E. coli isolates from SBP compared to other types of infection. Various types of E. coli infection were associated with differences in bacterial motility, virulence factors, and antibiotic susceptibility. More bacterial virulence factors may be necessary for the development of extraintestinal infections caused by E. coli isolates with lower motility.

Clinical and microbiological characteristics of Klebsiella pneumoniae from community-acquired recurrent urinary tract infections

Understanding the pathogenesis of recurrent urinary tract infection (RUTI) and whether it is attributable to reinfection with a new strain or relapse with the primary infecting strain is of considerable importance. Because previous studies regarding community-acquired Klebsiella pneumoniae RUTI are inconclusive, we undertook this study to evaluate the characteristics of the host and the bacterial agent K. pneumoniae in RUTI. A prospective study was designed, using consecutive patients diagnosed with community-acquired K. pneumoniae-related UTI from January 2007 to December 2009. Of the total 468 consecutive episodes, we found 7 patients with RUTI. All the patients with RUTI were elderly (median, 74 years), with diabetes (100 %, 7 out of 7). Clinical K. pneumoniae isolates derived from the same patients with RUTI revealed identical genomic fingerprints, indicating that K. pneumoniae UTI relapsed despite appropriate antibiotic therapy. The antimicrobial resistance, growth curve and biofilm formation of the recurrent isolates did not change. K. pneumoniae strains causing RUTI had more adhesion and invasiveness than the colonization strains (p < 0.01). When we compared the recurrent strains with the community-acquired UTI strains, the prevalence of diabetes mellitus was significant (100 % vs 53.7 %, p = 0.03) in the RUTI group. Our data suggest that K. pneumoniae strains might be able to persist within the urinary tract despite appropriate antibiotic treatment, and the greater adhesion and invasiveness in the recurrent strains may play an important role in recurrent infections.

Long-term efficacy of miglustat in paediatric patients with Niemann-Pick disease type C

Niemann-Pick disease type C (NP-C) is a rare inherited neurovisceral disease characterized by progressive neurological manifestations. Oral miglustat was first approved for the treatment of children and adults with NP-C in Europe in 2009. There are still relatively few published data on the long-term efficacy and safety of miglustat in patients with NP-C in clinical practice. We report the effects of up to 6 years of treatment with miglustat 100 mg t.i.d. in five children. Overall, 3/5 patients displayed progressive dysphagia before starting miglustat, and 4/5 showed marked cognitive and/or motor impairment. The mean age at treatment start was 11.6 years, and the median (range) duration of therapy so far is 4 (4.1 to 6.1) years. No treatment dose alterations were required, but therapy was interrupted for 1-3 months at least once in all patients due to supply issues. Swallowing function was stabilised during miglustat therapy, with no significant increase in Han dysphagia scale or aspiration-penetration index scores among four evaluable patients (p > 0.05). Scores on the mini-mental state examination indicated an improvement in cognitive function during the first 3-6 months of miglustat therapy, followed by stabilisation up to 5 years. Ambulatory function remained stable for at least the first 2 years of treatment in most patients, but there was a trend towards deterioration thereafter, possibly related to treatment interruptions. The safety/tolerability profile of miglustat was similar to previous clinical studies, although reports of gastrointestinal disturbances were rare. Overall, miglustat appeared to stabilise key parameters of neurological disease progression.

Role of K1 capsule antigen in cirrhotic patients with Escherichia coli spontaneous bacterial peritonitis in southern Taiwan

Spontaneous bacterial peritonitis (SBP) is one of the most serious complications in patients with cirrhosis. This study aimed to investigate the prevalence of SBP caused by Escherichia coli isolates with or without the K1 capsule antigen in cirrhotic patients and the outcome. From January 2004 to January 2012, a total of 54 and 41 E. coli strains derived from patients with SBP and intestinal perforation (IP), respectively, were included for comparison in this study. Bacterial characteristics including phylogenetic groups, K1 capsule antigen, and 14 virulence factor genetic determinants, as well as data regarding patient characteristics, clinical manifestations, and in-hospital deaths, were collected and analyzed. The prevalence of the K1 capsule antigen gene neuA was more common in SBP isolates compared to IP isolates (28 % vs. 10 %, p = 0.0385). Phylogenetic groups B2 and group D were dominant in E. coli isolates with and without the K1 capsule antigen, respectively. The prevalence of virulence factors genes papG II, ompT, and usp was higher in E. coli K1 strains. There were 26 deaths (48 %) during hospitalization. Presence of the K1 capsule antigen in E. coli isolates was significantly associated with in-hospital death in cirrhotic patients with SBP (42 % vs. 14 %, p = 0.0331). This study demonstrates a higher prevalence of the K1 capsule antigen in E. coli SBP compared to E. coli peritonitis caused by IP. There were significant associations between the K1 capsule antigen and in-hospital mortality and bacterial virulence in cirrhotic patients with E. coli SBP.

Soy food supplementation, dietary fat reduction and peripheral blood gene expression in postmenopausal women--a randomized, controlled trial

SCOPE

The effect of soy food supplementation or dietary fat reduction on gene expression is not well studied.

METHODS AND RESULTS

We evaluated the potential of gene expression profiling in peripheral blood mononuclear cells (PBMCs) collected at baseline and at the completion of an 8-wk controlled dietary intervention. Healthy postmenopausal women were randomized to a very-low-fat diet (VLFD; 11% of energy as fat) (n=21), a Step 1 diet (25% energy as fat) supplemented with soy food (SFD; 50 mg isoflavones per day) (n=20), or a control Step 1 diet (CD; 27% energy as fat) with no SFD (n=18). All diets were prepared at the General Clinical Research Center of the University of Southern California. We did not observe any gene that showed variable response across the three dietary interventions. However, there were notable changes in gene expression associated with the intervention in the VLFD and SFD groups. Our findings suggest that the expression of nicotinamide phosphoribosyltransferase (NAMPT) and genes related to Fc γ R-mediated phagocytosis and cytokine interactions may be significantly altered in association with dietary fat reduction and soy supplementation. Gene expression changes in NAMPT were somewhat dampened with adjustment for weight but changes related to Fc γ R-mediated phagocytosis and cytokine interactions remained largely unchanged.

CONCLUSION

PBMCs can reveal novel gene expression changes in association with controlled dietary intervention.

PapG II adhesin in the establishment and persistence of Escherichia coli infection in mouse kidneys

Most human pyelonephritogenic Escherichia coli express the PapG II adhesin. However, the role of the PapG II adhesin in enhancing the establishment and persistence of E. coli infection in the kidney is controversial. A pyelonephritogenic strain, EC114, which possesses one copy of the papG II gene, but without other virulence factors (such as S/F1C-fimbriae, hemolysin, and cytotoxic necrotizing factor 1) was selected for the construction of a papG II mutant. The resulting papG II mutant was confirmed by polymerase chain reaction, Southern hybridization, and agglutination assay, and designated as MEC114. We compared MEC114 with the parental strain (EC114) for colonization ability in the bladder and kidney of female BALB/c mice, which were challenged transurethrally with 50 microl of a low (5x10(4) CFU (colony-forming unit)) or high (5x10(8) CFU) dose of EC114 or MEC114 and assessed 1, 3, and 7 days after inoculation. Geometric means of quantitative bacterial counts in the kidney were significantly decreased when challenged with MEC114 on day 3 after inoculation, at both low and high dose (P<0.05), as compared with EC114. On the seventh day, both strains were mainly cleared from the kidney. Renal biopsy showed a similar degree of inflammatory response to both strains 1, 3, and 7 days after inoculation. In brief, the PapG II adhesin can enhance the early establishment of E. coli infection in the kidney, but the bacteria do not maintain infection owing to the host immune response.

A novel application of an anaerobic membrane process in wastewater treatment

The applications of membrane processes in anaerobic biological wastewater treatment still have some limitations due to severe membrane scaling and fouling, although they have been proven to achieve superior COD removal and biomass retention. An innovative anaerobic membrane process for wastewater treatment was conducted to control the membrane scaling problems. The process comprises an anaerobic reactor, an aerobic reactor, and a membrane separation tank. Anaerobic sludge from a full-scale UASB reactor treating food wastewater was inoculated to anaerobic and aerobic reactor to purify synthetic wastewater consisting of glucose and sodium acetate. The anaerobic reactor was operated in a sludge bed type without three-phase separator. The aerobic reactor can eliminate residual organics from the anaerobic reactor effluent using facultative microorganisms. To provide solid-liquid separation, hollow fiber ultrafiltration module was submerged in the separation tank. The results clearly show that the anaerobic membrane process combined methanogenic and aerobic COD reduction is a stable system. No fatal scaling was found after two months of operation even without chemical cleaning for the membrane. It was also found that inorganic precipitates formed in the aerobic reactor were reduced due to CO2 stripping in aerobic reactor. Another important finding was that the inorganic precipitates were entrapped into facultative aerobes floc. The ash/SS ratio of aerobes floc increased from 0.17 to 0.55 after 50 days of operation, which confirms this phenomenon. Based on our investigation, the new process can control scaling effectively to extend the membrane application in anaerobic treatment.

Glycopeptide antibiotic biosynthesis: enzymatic assembly of the dedicated amino acid monomer (S)-3,5-dihydroxyphenylglycine

Four proteins, DpgA-D, required for the biosynthesis by actinomycetes of the nonproteinogenic amino acid monomer (S)-3,5-dihydroxyphenylglycine (Dpg), that is a crosslinking site in the maturation of vancomycin and teicoplanin antibiotic scaffolds, were expressed in Escherichia coli, purified in soluble form, and assayed for enzymatic activity. DpgA is a type III polyketide synthase, converting four molecules of malonyl-CoA to 3,5-dihydroxyphenylacetyl-CoA (DPA-CoA) and three free coenzyme A (CoASH) products. Almost no turnover was observed for DpgA until DpgB was added, producing a net k(cat) of 1-2 min(-1) at a 3:1 ratio of DpgB:DpgA. Addition of DpgD gave a further 2-fold rate increase. DpgC had the unusual catalytic capacity to convert DPA-CoA to 3,5-dihydroxyphenylglyoxylate, which is a transamination away from Dpg. DpgC performed a net CH(2) to C=O four-electron oxidation on the Calpha of DPA-CoA and hydrolyzed the thioester linkage with a k(cat) of 10 min(-1). Phenylacetyl-CoA was also processed, to phenylglyoxylate, but with about 500-fold lower k(cat)/K(M). DpgC showed no activity in anaerobic incubations, suggesting an oxygenase function, but had no detectable bound organic cofactors or metals. A weak enoyl-CoA hydratase activity was detected for both DpgB and DpgD.

Decreased predominance of papG class II allele in Escherichia coli strains isolated from adults with acute pyelonephritis and urinary tract abnormalities

PURPOSE

We compared the genotypes of fimbriae or adhesions of Escherichia coli causing acute pyelonephritis in adults with and without urinary tract abnormalities.

MATERIALS AND METHODS

We studied a total of 92 E. coli strains isolated from 54 patients with acute pyelonephritis and a normal urinary tract, and 38 with urinary tract abnormalities. Of those with urinary tract abnormalities 13 with moderate to severe hydronephrosis were also considered a separate group for the purpose of analysis. The genes of 7 known fimbriae or adhesins of E. coli were detected by the polymerase chain reaction, including the papG class I to III alleles (PapG adhesins of P-fimbriae), sfa/foc (S-/F1C-fimbriae), fimH (type 1 fimbriae), and afa (afimbrial adhesin). Virulence genes associated with APN were identified by comparing the prevalence of each of these 7 genes in E. coli strains from 54 patients with acute pyelonephritis with a normal urinary tract to the prevalence in the strains from 37 patients with acute cystitis using univariate and multivariate analysis. Differences in the prevalence of the genes associated with acute pyelonephritis and the incidence of underlying illness were then compared in the 3 acute pyelonephritis groups.

RESULTS

On univariate and multivariate analysis the papG class II allele was the only virulence gene associated with acute pyelonephritis (p <0.0001 and 0.001, respectively). No significant difference was noted in the prevalence of underlying medical disease in the 3 acute pyelonephritis groups. The papG class II allele was significantly less predominant in E. coli strains isolated from acute pyelonephritis cases with versus without urinary tract abnormalities (76% versus 93%, p = 0.03). The incidence of the papG class II allele in patients with urinary tract abnormalities and moderate to severe hydronephrosis was less than in those without urinary tract abnormalities (69% versus 93%, p = 0.04).

CONCLUSIONS

Our results imply that the papG class II allele has an important role in E. coli infection in patients with acute pyelonephritis and a normal urinary tract, while urinary tract abnormalities and/or obstruction may permit ascending infection of E. coli strains with lower adhesive ability.

Real-time PCR for rapid genotyping of angiotensin-converting enzyme insertion/deletion polymorphism

OBJECTIVE

To develop a real-time PCR technique for detection of the insertion/deletion (I/D) polymorphism of angiotensin-converting enzyme (ACE) gene.

DESIGN AND METHODS

Three primers were designed for performing real-time PCR in the presence of SYBR Green I as flurochrome followed by melting curve analysis. Forty human genomic DNA that have been genotyped by two-rounds of conventional PCR were used for evaluation of this technique.

RESULTS

Melting curve analysis indicated the melting peak at 73.9 degrees C and 76.2 degrees C corresponding to the presence of I and D alleles, respectively. Comparable genotyping results were obtained by both conventional and real-time PCR. Besides, the mistyping of ID allele individuals by the first run of conventional PCR were accurately genotyped by single-tube real time PCR.

CONCLUSIONS

The real-time PCR method presented in this study provides a rapid and sensitive way for genotyping of ACE gene that may be suitable for large-scale clinical and epidemiologic study.

Induction of disabled-2 gene during megakaryocyte differentiation of k562 cells

Megakaryocyte differentiation is often accompanied by the changes of gene expression pattern. Here we reported that the expression of DAB2, a putative adaptor protein in cell signaling, was induced at the protein and mRNA levels upon 12-O-tetradecanoylphorbol-13-acetate-mediated megakaryocyte differentiation of human chronic myeloid leukemic K562 cells. On the other hand, the differentiation agents DMSO and retinoic acid had no effect on DAB2 expression. Analysis of promoter activity with the human DAB2 luciferase reporter constructs suggested that the regulation is partially at the transcriptional level. The responsive sequences located within an 80-bp DAB2 promoter region. To determine the involvement of MEK1-p42/p44 MAPK pathway in mediating DAB2 gene expression, we have performed the following experiments and found that (i) there was sustained activation of p42/p44 MAPK, but not p38 MAPK, upon K562 cells differentiation; (ii) application of MEK1 inhibitor U0126 reduced the expression of DAB2 protein, mRNA and promoter activity, as well as cell differentiation; (iii) constitutively active MEK1 increased DAB2 promoter activity; and (iv) dominant negative ERK2 abolished constitutively active MEK1-induced DAB2 promoter activity. Taken together, our results indicate that DAB2 gene is induced upon megakaryocyte differentiation by the MEK1-p42/p44 MAPK pathway and may define a new role of DAB2 in hematopoietic cell differentiation.

Assessing relocation strategies of urban air quality monitoring stations by GA-based compromise programming

This paper presents a GA-based compromise programming technique for assessing the relocation strategy of urban air quality monitoring network with respect to the multi-objective and multi-pollutant design criteria. While the impact of conservative, quasi-stable, and reactive pollutants are considered in the design principles via a simulation analysis, cost, effectiveness, and efficiency characteristics are postulated in the optimization process. Therefore, technical coverage for illustrating the needs of siting air quality monitoring stations (AQMS) includes both the air quality simulation and optimization modeling analyses in a two-stage analytical framework simultaneously. It starts from determining the spatial interrelationship among those candidate sites using various types of air quality simulation models as an integrated means. And the outputs drawn from the simulation models can then be used as the required inputs in the compromise programming model in order to screen all those siting alternatives that may satisfy the planning goals subject to the essential constraints throughout the multi-objective optimization process. For the illustrating purposes, a series of technical settings for finding the optimal relocation scenarios of AQMS were examined in the case study for the city of Kaohsiung in South Taiwan where the long-term violations of official standards of ozone and particulates turn out to be critical. It not only expresses the ideas of relocation strategy but also indicates how to utilize those alternatives in the decision-making process for improving the functionality of air quality monitoring in the urban environment. Experience gained in this study clearly indicates that the more the number of pollutants and objectives considered simultaneously, the higher the number of candidate sites to be selected in the relocation strategy.

25-hydroxyvitamin D-1alpha-hydroxylase in normal and malignant colon tissue

Vitamin D affects calcium metabolism and prevents proliferation of colon cells in vitro. In human beings the main circulating form of vitamin D is 25-hydroxyvitamin D; to regulate calcium homoeostasis, this form must be converted to 1alpha, 25-dihydroxyvitamin D by 1alpha-hydroxylation in the kidney with 25-hydroxyvitamin D-1alpha-hydroxylase. Cultured transformed colon cancer cells can convert 25-hydroxyvitamin D(3) to 1alpha,25-dihydroxyvitamin D(3). We identified messenger RNA (mRNA) for 25-hydroxyvitamin D-1alpha-hydroxylase in normal colon tissue and in malignant and adjacent normal colon tissue. These findings support the notion that vitamin D might have a role in cell growth regulation and cancer protection, and might be the explanation for why the risk of dying from colorectal cancer is highest in areas with the least amount of sunlight.

A nucleus-localization-deficient mutant serves as a dominant-negative inhibitor of gut-enriched Krüppel-like factor function

Cancer cells differ from normal cells in many aspects, including loss of differentiation and uninhibited cell proliferation. Recent studies have suggested that gut-enriched Krüppel-like factor (GKLF) played an important role in the regulation of cell growth in the colon. Studies from this laboratory have shown that GKLF protein predominantly expressed in the cytoplasm but not the nucleus of colon cancer cells, suggesting that impaired nuclear translocation of GKLF might contribute to cancer formation. In this report, a region containing putative nuclear localization signal (NLS) of GKLF (PKRGRR; amino acids 385-390) was investigated. Mutation of KR to WT had no effect on the inhibitory properties of GKLF on cyclin D1 promoter activity and [(3)H]thymidine uptake in HT-29 cells, whereas mutation of RR to GL abolished GKLF function completely. Additional mutation analyses demonstrated that Arg(390) is the most critical moiety within this region that mediated GKLF function and its nucleus localization. Cotransfection of Arg(390) mutant (RR/RS) completely inhibited wild-type GKLF function, and GFP-RR/RS GKLF fusion proteins failed to translocate to the nucleus. The results from this study demonstrate that Arg(390) confers the NLS of GKLF and that the nucleus-localization-deficient mutant serves as dominant-negative inhibitor of GKLF function.

The clinical use of small-dose tetracaine spinal anesthesia for transurethral prostatectomy

In a double-blinded study, we compared conventional dose tetracaine (8 mg), small-dose tetracaine (4 mg) with added fentanyl and epinephrine, and small-dose tetracaine (4 mg) with added fentanyl subarachnoid anesthesia. Forty-five patients scheduled for transurethral resection of prostate (TURP) under subarachnoid anesthesia were randomly assigned to Group 1 (8 mg hyperbaric tetracaine), Group 2 (4 mg hyperbaric tetracaine, 10 microg fen-tanyl, and 0.2 mg epinephrine), and Group 3 (4 mg hyperbaric tetracaine, 10 microg fentanyl, and 0.2 mL saline). Evaluations were performed after spinal anesthesia. Subarachnoid block was successful in all patients except one in Group 1, who required general anesthesia by mask. The median peak sensory levels 10 min after the induction of spinal anesthesia in Group 1 was T8, which was significantly higher than Group 2 and Group 3 (P < 0.05). The time of sensory and motor recovery in Group 3 was less than in Groups 1 and 2 (P < 0.05). Hypotension was observed in four patients in Group 1 and none in Groups 2 and 3. We conclude that small-dose 4-mg hyperbaric tetracaine plus 10 microg fentanyl might provide adequate anesthesia and fewer side effects for TURP when compared with the conventional (8 mg) dose.

IMPLICATIONS

Small-dose hyperbaric tetracaine (4 mg with 10 microg fentanyl added) may provide adequate anesthesia and fewer side effects for transurethral resection of the prostate.

Detection rate of Actinobacillus actinomycetemcomitans on the permanent 1st molars of primary school children in Taiwan by polymerase chain reaction

BACKGROUND, AIMS

Actinobacillus actinomycetemcomitans (Aa) has been implicated as the putative micro-organism for localized juvenile periodontitis (LJP). The most distinct clinical features of LJP include severe angular bony defects of the mesial sides of permanent first molars and the onset of disease during puberty. Currently, no large-scale studies have been performed which address the change in detection rates of Aa on the mesial sides of permanent 1st molars following eruption and up to puberty.

METHOD

In this study, subgingival plaque samples were taken from the mesial pockets of 2 randomly selected permanent 1st molars from 328 primary school children and 50 adult staff, and analyzed by polymerase chain reaction (PCR) to detect Aa.

RESULTS

The results showed a 5.5% prevalence rate of Aa which increased after the eruption of 1st molars and peaked near puberty. There were no significant differences in the detection rates of Aa among different groups in terms of gender, plaque index (PII), and gingival index (GI); however, the higher detection rates of Aa were significantly associated with increased probing depths at p<0.05.

CONCLUSION

PCR analysis of the subgingival plaques demonstrated a prevalence of Aa which peaked near puberty, suggesting that Aa may be important for LJP in Taiwan.

Correlation of histologic subtypes and replication error phenotype with comparative genomic hybridization in gastric cancer

To characterize phenotypic and genotypic changes in gastric cancer (GC), DNA copy number aberrations (CNAs) were assessed in 53 tumors using comparative genomic hybridization (CGH) and correlated with clinicopathologic characteristics and status of TP53 and replication error (RER). The number of CNAs per tumor was 6.8 (gain 5.3, loss 1.5), and the number of changes was significantly higher in tumors with advanced stage, TP53 mutation, and without RER than in those with early stage (7.7 vs. 3.0), no TP53 mutations (12.4 vs. 4.8) or RER phenotype (8.2 vs. 2.6). Frequent abnormalities included gains on chromosomal arms 8q (43%), 6q (26%), 11q (26%), 13q (24%), 7p (23%), 17q (23%), and 20q (23%), and losses on chromosomal arms 16q (26%), 19p (23%), 5q (19%), 3p (15%), 4q(15%), and 1p (15%). Advanced GC demonstrated a higher prevalence of gains of 8q (51% vs. 10%, P < 0.05) and loss of 16q (33% vs. 0%, P < 0.05) than early GC. Gains on 8q (64% vs. 20%, P < 0.05), 17q (39% vs. 4%, P < 0.05) and losses on 3p (25% vs. 4%, P = 0.05) and 5q (32% vs. 4%, P < 0.05) were higher in intestinal GC than in diffuse GC. On the other hand, gains on 13q were more common in the diffuse type (40% vs. 11%, P < 0.05). As compared with noncardia cancer, cardia cancer showed more gains on 7p (58% vs. 12%, P < 0.05) and 20q (58% vs. 12%, P < 0.05) and more losses on 4q (50% vs. 5%, P < 0.05). The finding of histology-related aberrations and the combination of CGH and molecular data thus provide additional evidence suggesting genetic heterogeneity of GC.

Detection of putative periodontal pathogens in non-insulin-dependent diabetes mellitus and non-diabetes mellitus by polymerase chain reaction

It has been assumed that there is a relationship between periodontal diseases and diabetes mellitus, however the putative periodontal microorganisms in non-diabetes mellitus (non-DM) individuals and non-insulin-dependent diabetes mellitus (NIDDM) patients have not been well studied. In this study, the detection rates of 5 putative periodontal pathogens: Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, Eikenella corrodens, Treponema denticola, and Candida albicans by polymerase chain reaction (PCR) between NIDDM and non-DM adults were compared. A total of 246 adults were randomly recruited and periodontal parameters including: plaque index (P1I), gingival index (GI), probing depth (PD) and attachment level (AL) were recorded. Subgingival plaque samples were collected by sterile curettes from the most diseased and healthy sites based on PD and AL. The differences in periodontal parameters and microbiological data in healthy and diseased sites between non-DM and NIDDM patients were compared by chi-square analysis. The results showed no significant differences in age, gender, GI, P1I, PD, and prevalence of the 5 microorganisms between the NIDDM and the non-diabetic groups. However, except for A. actinomycetemcomitans, the prevalence of the periodontal microorganisms tested was significantly higher (p <0.001) in diseased sites than in the healthy sites in both groups. The P1I, GI, PD and AL were significantly higher in T. denticola positive sites than in negative sites. The results suggested that P. gingivalis, T. denticola, E. corrodens and C. albicans may play important roles in the periodontitis of both NIDDM and non-DM individuals, however the etiology of periodontitis in both groups may not be different from each other.

Purification, priming, and catalytic acylation of carrier protein domains in the polyketide synthase and nonribosomal peptidyl synthetase modules of the HMWP1 subunit of yersiniabactin synthetase

The 207-kDa polyketide synthase (PKS) module (residues 1-1895) and the 143-kDa nonribosomal peptidyl synthetase (NRPS) module (1896-3163) of the 350-kDa HMWP1 subunit of yersiniabactin synthetase have been expressed in and purified from Escherichia coli in soluble forms to characterize the acyl carrier protein (ACP) domain of the PKS module and the homologous peptidyl carrier protein (PCP(3)) domain of the NRPS module. The apo-ACP and PCP domains could be selectively posttranslationally primed by the E. coli ACPS and EntD phosphopantetheinyl transferases (PPTases), respectively, whereas the Bacillus subtilis PPTase Sfp primed both carrier protein domains in vitro or during in vivo coexpression. The holo-NRPS module but not the holo-PKS module was then selectively aminoacylated with cysteine by the adenylation domain embedded in the HMWP2 subunit of yersiniabactin synthetase, acting in trans. When the acyltransferase (AT) domain of HMWP1 was analyzed for its ability to malonylate the holo carrier protein domains, in cis acylation was first detected. Then, in trans malonylation of the excised holo-ACP or holo-PCP(3)-TE fragments by HMWP1 showed both were malonylated with a 3:1 catalytic efficiency ratio, showing a promiscuity to the AT domain.

Correlation of histologic subtypes and replication error phenotype with comparative genomic hybridization in gastric cancer

To characterize phenotypic and genotypic changes in gastric cancer (GC), DNA copy number aberrations (CNAs) were assessed in 53 tumors using comparative genomic hybridization (CGH) and correlated with clinicopathologic characteristics and status of TP53 and replication error (RER). The number of CNAs per tumor was 6.8 (gain 5.3, loss 1.5), and the number of changes was significantly higher in tumors with advanced stage, TP53 mutation, and without RER than in those with early stage (7.7 vs. 3.0), no TP53 mutations (12.4 vs. 4.8) or RER phenotype (8.2 vs. 2.6). Frequent abnormalities included gains on chromosomal arms 8q (43%), 6q (26%), 11q (26%), 13q (24%), 7p (23%), 17q (23%), and 20q (23%), and losses on chromosomal arms 16q (26%), 19p (23%), 5q (19%), 3p (15%), 4q(15%), and 1p (15%). Advanced GC demonstrated a higher prevalence of gains of 8q (51% vs. 10%, P < 0.05) and loss of 16q (33% vs. 0%, P < 0.05) than early GC. Gains on 8q (64% vs. 20%, P < 0.05), 17q (39% vs. 4%, P < 0.05) and losses on 3p (25% vs. 4%, P = 0.05) and 5q (32% vs. 4%, P < 0.05) were higher in intestinal GC than in diffuse GC. On the other hand, gains on 13q were more common in the diffuse type (40% vs. 11%, P < 0.05). As compared with noncardia cancer, cardia cancer showed more gains on 7p (58% vs. 12%, P < 0.05) and 20q (58% vs. 12%, P < 0.05) and more losses on 4q (50% vs. 5%, P < 0.05). The finding of histology-related aberrations and the combination of CGH and molecular data thus provide additional evidence suggesting genetic heterogeneity of GC.

Adult-onset minimal change disease among Taiwanese: clinical features, therapeutic response, and prognosis

There are some racial differences in the prevalence and prognosis of idiopathic nephrotic syndrome; however, reports about minimal change disease (MCD) in Chinese were rare. We retrospectively analyzed 123 Chinese adults with idiopathic nephrotic syndrome, who received percutaneous renal biopsy in our institution within the last 10 years. In total, 46 patients (37.4%) were compatible with the pathological diagnosis of MCD. The male to female ratio was 1.2:1. The mean age of onset was 30.9 years, and 80% of the patients with MCD were less than 40 years. The mean daily proteinuria was 10.2 g, and serum albumin was 1.8 mg/dl. Azotemia occurred in 16 (35%) of 46 cases; hypertension, 13%; and microscopic hematuria, 13%. High selectivity index for proteinuria (SI <0.1) was noted in 12 (39%) of 31 cases; and high IgE level was found in 83.7% of the study subjects, although only one case had allergic history. Complete remission in 36 MCD patients treated with corticosteroid was achieved by 42% (15/36), 80% (29/36), and 94% (34/36) within 4, 8, and 12 weeks, respectively. The time interval to remission was similar between the younger group (<40 years old, 1.7 months) and older group (>40 years old, 1.6 months). Nineteen (56%) of 34 cases with steroid response did not relapse, and the other cases (44%) had a mean relapse rate of 1.5 times per patient within a period of 45 months. The age of onset in MCD cases was not significantly correlated with steroid-responsive rate, and the time interval to remission. However, a tendency existed between the onset in the young age and the sequentially relapsing rate (p = 0.06). Two cases with primary steroid resistance and 5 cases with frequent relapse or steroid dependence responded well to intravenous pulse therapy of cyclophosphamide, except one refractory case. No thrombotic episode was ever noted in our group. Regarding infectious complications, primary peritonitis occurred in one, pneumonia in one, and cellulitis in 6 cases during active nephrotic stage. Two mortality cases, one with E. coli-related necrotizing fasciitis and one from pneumonia, were noted. In brief, compared with children, adult patients with MCD had lesser high selectivity index for proteinuria, the same steroid-responsive rate (94%), but slower response, and significantly lesser relapsing rate. The intravenous pulse therapy of cyclophosphamide may be an alternative regimen for adult patients with steroid resistance or dependency. In addition, the Asian adult-onset MCD had younger age, male predominance, and lesser relapsing rate in comparison to those of the Western population.

Blood pressure and left ventricular hypertrophy in patients on different peritoneal dialysis regimens

OBJECTIVE

To examine the relation between the results of ambulatory 24-hour blood pressure monitoring (ABPM) and left ventricular mass index (LVMI), then to find the independent determinant for left ventricular hypertrophy (LVH) in peritoneal dialysis (PD) patients. Finally, to evaluate the differences in the clinical and cardiovascular characteristics between patients on continuous ambulatory PD (CAPD) and continuous cyclic PD (CCPD).

DESIGN

An open, nonrandomized, cross-sectional study.

SETTING

Divisions of nephrology and cardiology in a medical center.

PATIENTS

Thirty-two uremic patients on maintenance PD therapy (22 patients on CAPD, and 10 on CCPD) without anatomical heart disease or history of receiving long-term hemodialysis.

INTERVENTIONS

Home blood pressure (BP) and office BP were measured using the Korotkoff sound technique by sphygmomanometer. ABPM was employed for continuous measurement of BP. Echocardiography was performed for measurement of cardiac parameters and calculation of LVMI.

MAIN OUTCOME MEASURES

Multivariate logistic regression analysis was performed for independent determinant of LVH in PD patients. The differences in clinical and cardiovascular characteristics between CAPD and CCPD patients were compared.

RESULTS

Simple regression analysis showed positive correlations between LVMI and the duration of hypertension, ambulatory nighttime BP/BP load/BP load > 30%, serum phosphate, calcium-phosphate product, ultrafiltration (UF) volume, and percentage of UF volume during the nighttime. A negative correlation was noted between LVMI and dipping. In multiple regression analysis, the duration of hypertension was the only variable linked to LVMI. In multivariate logistic regression analysis, only ambulatory nighttime systolic BP load > 30% had an independent association with LVH. There were correlations between office/home BP and ambulatory 24-hour BP. In addition, CCPD patients had higher LVMI, UF volume during the nighttime, and percentage of UF volume during the nighttime than those of CAPD patients.

CONCLUSIONS

In this study, ambulatory nighttime systolic BP load > 30% had an independent association with LVH. Office and home BP measurements were correlated with ABPM in PD patients. The result that CCPD patients had a higher LVMI than CAPD patients may be due to a relative volume overload during the daytime in CCPD patients.

Real-time PCR for quantitative detection of Toxoplasma gondii

The protozoan Toxoplasma gondii is one of the most common infectious pathogenic parasites and can cause severe medical complications in infants and immunocompromised individuals. We report here the development of a real-time PCR-based assay for the detection of T. gondii. Oligonucleotide primers and a fluorescence-labeled TaqMan probe were designed to amplify the T. gondii B1 gene. After 40 PCR cycles, the cycle threshold values (C(T)) indicative of the quantity of the target gene were determined. Typically, a C(T) of 25.09 was obtained with DNA from 500 tachyzoites of the T. gondii RH strain. The intra-assay coefficients of variation (CV) were 0.4, 0.16, 0.24, and 0.79% for the four sets of quadruplicate assays, with a mean interassay CV of 0.4%. These values indicate the reproducibility of this assay. Upon optimization of assay conditions, we were able to obtain a standard curve with a linear range (correlation coefficient = 0.9988) across at least 6 logs of DNA concentration. Hence, we were able to quantitatively detect as little as 0.05 T. gondii tachyzoite in an assay. When tested with 30 paraffin-embedded fetal tissue sections, 10 sections (33%) showed a C(T) of <40 and were scored as positive for this test. These results were consistent with those obtained through our nested-PCR control experiments. We have developed a rapid, sensitive, and quantitative real-time PCR for detection of T. gondii. The advantages of this technique for the diagnosis of toxoplasmosis in a clinical laboratory are discussed.

Role of gut-enriched Krüppel-like factor in colonic cell growth and differentiation

Cancer cells differ from normal cells in many aspects, including hyperproliferation and loss of differentiation. Recent research has focused on the role of transcription factors in regulating abnormal cell growth. Gut-enriched Krüppel-like factor (GKLF) is a newly identified eukaryotic zinc finger protein expressed extensively in the gastrointestinal tract. In the current study, we demonstrated that GKLF mRNA levels were significantly decreased in the dysplastic epithelium of the colon, including adenomatous polyp and cancer. GKLF immunostains in the normal colon were higher at the surface epithelium and gradually decreased toward the crypt, but this gradient was not present in the adenomatous and cancerous mucosa. Constitutive overexpression of GKLF DNA in a human colonic adenocarcinoma cell line (HT-29) decreased [(3)H]thymidine incorporation, whereas suppression of GKLF gene increased DNA synthesis, indicating that downregulation of the GKLF gene might contribute to cellular hyperproliferation. Cyclin D1 (CD1) protein level and CD1-associated kinase activity were decreased in HT-29 cell overexpressed GKLF cDNA, and CD1 promoter activity was profoundly suppressed by GKLF. When HT-29 cells were cultured in the presence of sodium butyrate, GKLF mRNA levels increased as cells acquired more differentiated phenotypes. These results suggest that GKLF plays an important role in regulating cell growth and differentiation in the colonic epithelium and that downregulation of GKLF expression may cause colonic cells to become hyperproliferative. Furthermore, GKLF appears to be a transcriptional repressor of the CD1 gene.

Nonsteroidal anti-inflammatory drugs

NSAID-associated dyspeptic symptoms are common and can be managed empirically with an H2-receptor antagonist or a proton-pump inhibitor. Treatment of established gastroduodenal ulcers is accomplished best by withholding the offending drugs. Proton-pump inhibitors appear to heal ulcers at the same rate whether or not NSAID therapy is continued. After the ulcer is healed and if NSAID therapy must be continued, prophylaxis is accomplished best by the concomitant use of proton-pump inhibitors, misoprostol (at least 200 micrograms 3 times a day), or a NSAID that preferentially inhibits COX-2. The future development of newer, safer NSAID preparations, including highly selective COX-2 inhibitors and nitric oxide-releasing NSAIDs, should provide better treatment options for the increasing number of individuals requiring anti-inflammatory agents.

Regulation of glucose-dependent insulinotropic polypeptide release by protein in the rat

Glucose-dependent insulinotropic polypeptide (GIP) release has been demonstrated predominantly after ingestion of carbohydrate and fat. These studies were conducted to determine the effects of protein on GIP expression in the rat. Whereas no significant changes in duodenal mucosal GIP mRNA levels were detected in response to peptone, the duodenal GIP concentration increased from 8.4+/-1.5 to 19.8+/-3.2 ng GIP/mg protein at 120 min (P<0.01). Plasma GIP levels also increased from 95+/-5.2 pg/ml to a peak of 289+/-56.1 pg/ml at 120 min (P<0.01). To determine whether the effects of protein on GIP were due to stimulation of acid secretion, rats were pretreated with 10 mg/kg omeprazole, after which mucosal and plasma GIP concentrations were partially attenuated. To further examine the effects of luminal acid, rats were administered intraduodenal 0.1 M HCl for 120 min, which significantly enhanced GIP expression. These studies indicate that nutrient protein provides a potent stimulus for GIP expression in the rat, an effect that occurs at the posttranslational level and may be mediated in part through the acid-stimulatory properties of protein. The effects of acid on GIP are consistent with a role for GIP as an enterogastrone in the rat.

Gut-enriched Krüppel-like factor represses cyclin D1 promoter activity through Sp1 motif

Cancer cells differ from normal cells in many characteristics including loss of differentiation and uninhibited cell proliferation. Recent studies have focused on the identification of factors contributing to cell growth and differentiation. Gut-enriched Krüppel-like factor (GKLF or KLF4) is a newly identified eukaryotic transcription factor and has been shown to play a role in regulating growth arrest. We have previously shown that GKLF mRNA levels were significantly decreased in colon cancer tissues, and that over-expression of GKLF in colonic adenocarcinoma cells (HT-29) resulted in reduction of cyclin D1 (CD1) mRNA and protein levels. The current study was undertaken to determine the mechanisms by which GKLF inhibited CD1 expression. In a transient transfection system, GKLF suppressed CD1 promoter activity by 55%. Sequential deletion and site-directed mutation analysis of the CD1 promoter have identified the sequence between -141 and -66, a region containing an Sp1 response element, to be essential for GKLF function. By electrophoretic mobility gel shift assay, recombinant GKLF and nuclear extracts from HT-29 cells were found to bind to the Sp1 motif on the CD1 promoter. The inhibitory effect of GKLF on the CD1 promoter activity was completely abolished by excessive amount of Sp1 DNA and GKLF significantly reduced the stimulatory function of Sp1 suggesting that GKLF and Sp1 may compete for the same binding site on the CD1 promoter. These results indicate that GKLF is a transcriptional repressor of the CD1 gene and that the inhibitory effect of GKLF is, in part, mediated by interaction with the Sp1 binding domain on its promoter.

Differential effect toward inhibition of papain and cathepsin C by recombinant human salivary cystatin SN and its variants produced by a baculovirus system

Human salivary cystatin SN (CsnSN) is a member of the cystatin superfamily of cysteine proteinase inhibitors. In this study we used a baculovirus expression system to produce a full-length unaltered CsnSN and its variants. The variants were constructed with the changes in the three predicted proteinase-binding regions: the N-terminus (variant N(12-13), G12A-G13A), beta-hairpin loop I (variant L(56-58), Q56G-T57G-V58G) and beta-hairpin loop II (variant L(106-107), P106G-W107G). The secreted CsnSNs were purified using sequential spiral cartridge ultrafiltration and DE-52 radial flow chromatography. The purified proteins were examined for papain- and cathepsin C-inhibition. The wild-type CsnSN, and variants N(12-13) and L(106-107) bound tightly to papain (K(i) < 10 pM), whereas mutation in the loop I reduced binding affinity 5700-fold (K(i) = 57 nM). On the other hand, the wild-type CsnSN bound to cathepsin C less tightly (K(i) = 100 nM). The mutation in the N-terminus or loop I reduced binding affinity by 16 (K(i) = 1.6 microM)- and 19-fold (K(i) = 1.9 microM), respectively, while mutation in loop II resulted in an ineffective cathepsin C inhibitor (K(i) = 14 microM). Collectively, these results suggest that the N-terminal G12-G13 residues of CsnSN are not essential for papain inhibition but play a role in cathepsin C inhibition; residues Q56-T57-V58 in the loop I are essential for both papain and cathepsin C inhibitions, and residues P106-W107 in the loop II are not important for papain inhibition but essential for cathepsin C inhibition. These results demonstrated that CsnSN variants have different effects toward different cysteine proteinases.

Identification of a novel secretory leukocyte protease inhibitor-binding protein involved in membrane phospholipid movement

Previous studies have suggested that human salivary secretory leukocyte protease inhibitor (SLPI) inhibits HIV-1 by binding to a host cell surface protein of unknown identity. Using the yeast two-hybrid assay, we identified a gene sequence encoding a novel SLPI-binding protein (SLPI-BP). The 1.5-kb cDNA encodes a 318-amino acid protein with a predicted transmembrane segment near the C-terminus. Sequence analysis revealed that SLPI-BP is the human scramblase protein that is involved in the movement of membrane phospholipids. Co-expression of SLPI and SLPI-BP followed by an S-protein pulldown assay confirmed the specific interaction between these two proteins. Our data represent the first report for the identity of SLPI-BP.

Emphysematous pyelonephritis: clinicoradiological classification, management, prognosis, and pathogenesis

BACKGROUND

Emphysematous pyelonephritis (EPN) is a rare, severe gas-forming infection of renal parenchyma and its surrounding areas. The radiological classification and adequate therapeutic regimen are controversial and the prognostic factors and pathogenesis remain uncertain.

OBJECTIVES

To elucidate the clinical features, radiological classification, and prognostic factors of EPN; to compare the modalities of management (ie, antibiotic treatment alone, percutaneous catheter drainage combined with antibiotic treatment, or nephrectomy) and outcome among the various radiological classes of EPN; and to clarify the gas-forming mechanism and pathogenesis of EPN by gas analysis and pathological findings.

PATIENTS AND METHODS

Forty-eight EPN cases from our institution were enrolled between August 1,1989, and November 30, 1997. According to the radiological findings on computed tomographic scan, they were classified into the following classes: (1) class 1: gas in the collecting system only; (2) class 2: gas in the renal parenchyma without extension to extrarenal space; (3) class 3A: extension of gas or abscess to perinephric space; class 3B: extension of gas or abscess to pararenal space; and (4) class 4: bilateral EPN or solitary kidney with EPN. The clinical manifestations, management, and outcome were compared. The gas contents of specimens from 6 patients were analyzed. The pathological findings from 8 patients who received nephrectomy were reviewed. The statistical methods consisted of the Fisher exact test (2 tailed) for categorical variables and Wilcoxon rank sum test for continuous variables to test the predictors of poor prognosis.

RESULTS

Forty-six patients (96%) had diabetes mellitus, and 10 (22%) of the 46 also had urinary tract obstruction in the corresponding renoureteral unit. The other 2 nondiabetic patients (4%) had severe hydronephrosis. Twenty-one (72%) of the 29 patients with diabetes mellitus also had a glycosylated hemoglobin A(1c) level higher than 0.08. Escherichia coli (69%) and Klebsiella pneumoniae (29%) were the most common pathogens. The mortality rate in patients who received antibiotic treatment alone was 40% (2 of 5 patients). The success rate of management by percutaneous catheter drainage (PCD) combined with antibiotic treatment was 66% (27 of 41 patients). In classes 1 and 2 EPN, all the patients who were treated using a PCD or ureteral catheter combined with antibiotic treatment survived. In extensive EPN (classes 3 and 4), 17 (85%) of the 20 patients with fewer than 2 risk factors (ie, thrombocytopenia, acute renal function impairment, disturbance of consciousness, or shock) were successfully treated using PCD combined with antibiotic treatment; and the patients with 2 or more risk factors had a significantly higher failure rate than those with no or only 1 risk factors (92% vs 15%, P<.001). Eight of the 14 patients who had an unsuccessful treatment using a PCD underwent subsequent nephrectomy, 7 of whom survived. Only 2 patients were managed by direct nephrectomy and survived. The overall success rate of nephrectomy was 90% (9 of 10 patients). The total mortality was 18.8% (9 of 48 patients). Five of the 6 gas samples contained hydrogen (average, 12.8%), and all had carbon dioxide (average, 14.4%). The pathological findings from 8 of 10 who underwent nephrectomy revealed poor perfusion in most cases (ie, infarction, 5 patients; vascular thrombosis, 3 patients; and arteriosclerosis and/or glomerulosclerosis, 4 patients).

CONCLUSION

Acute renal infection with E coli or K pneumoniae in patients with diabetes mellitus and/or urinary tract obstruction is the cornerstone for the development of EPN. Mixed acid fermentation of glucose by Enterobacteriaceae is the major pathway of gas formation. For localized EPN (classes 1 and 2), PCD combined with antibiotic treatment can provide a good outcome. (ABSTRACT TRUNCATED)

Role of G protein-coupled receptor kinases in glucose-dependent insulinotropic polypeptide receptor signaling

The glucose-dependent insulinotropic polypeptide receptor (GIPR) is a member of class II G protein-coupled receptors. Recent studies have suggested that desensitization of the GIPR might contribute to impaired insulin secretion in type II diabetic patients, but the molecular mechanisms of GIPR signal termination are unknown. Using HEK L293 cells stably transfected with GIPR complementary DNA (L293-GIPR), the mechanisms of GIPR desensitization were investigated. GIP dose dependently increased intracellular cAMP levels in L293-GIPR cells, but this response was abolished (65%) by cotransfection with G protein-coupled receptor kinase 2 (GRK2), but not with GRK5 or GRK6. Beta-arrestin-1 transfection also induced a significantly decrease in GIP-stimulated cAMP production, and this effect was greater with cotransfection of both GRK2 and beta-arrestin-1 than with either alone. In betaTC3 cells, expression of GRK2 or beta-arrestin-1 attenuated GIP-induced insulin release and cAMP production, whereas glucose-stimulated insulin secretion was not affected. GRK2 and beta-arrestin-1 messenger RNAs were identified by Northern blot analysis to be expressed endogenously in betaTC3 and L293 cells. Overexpression of GRK2 enhanced agonist-induced GIPR phosphorylation, but receptor endocytosis was not affected by cotransfection with GRKs or beta-arrestin-1. These results suggest a potential role for GRK2/beta-arrestin-1 system in modulating GIP-mediated insulin secretion in pancreatic islet cells. Furthermore, GRK-mediated receptor phosphorylation is not required for endocytosis of the GIPR.

Effects of a nitric oxide scavenger, carboxy-PTIO, on isoflurane MAC and cerebellar nitric oxide synthase activity in rats

Recent studies have indicated that nitric oxide may play a role in inhalation anaesthesia. Inhibition of nitric oxide synthase reduces the minimum alveolar concentration (MAC) for inhalation anaesthetics and decreases cerebellar nitric oxide synthase (NOS) activity in rats. In this study, we have explored further the role of nitric oxide in isoflurane anaesthesia by examining the effects of a nitric oxide scavenger, 2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide (carboxy-PTIO 0.075-0.6 mg kg-1) on MAC values and cerebellar NOS activity in rats. Bolus injection of carboxy-PTIO at doses greater than 0.15 mg kg-1 reduced the MAC value of isoflurane (mean 1.36 (SEM 0.07)% at 0.15 mg kg-1, 1.39 (0.14)% at 0.3 mg kg-1 and 1.31 (0.06)% at 0.6 mg kg-1 vs control value of 1.61 (0.19)%. Administration of carboxy-PTIO 0.125 and 0.15 mg kg-1 resulted in increased cerebellar NOS activity during isoflurane anaesthesia (P < 0.05). These findings suggest that the level of nitric oxide may set a baseline from which isoflurane then acts.

Double cancers of the kidney and ureter complicated with emphysematous pyelonephritis within the parenchyma of the renal tumour

Emphysematous pyelonephritis and double cancers of the kidney and urinary tract are rare. We describe here a case of a diabetic man who had simultaneous renal cell carcinoma of the right kidney and transitional cell carcinoma of the right ureter complicated with emphysematous pyelonephritis within the tumour parenchyma of renal cell carcinoma. Imaging and pathology are demonstrated.

Effect of GIP and GLP-1 antagonists on insulin release in the rat

Glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide 1 (GLP-1) are potent insulinotropic peptides released from the small intestine. To examine their relative contribution to postprandial insulin release, a specific GIP antagonist (ANTGIP) and a GLP-1 antagonist, exendin-(9-39)-NH2, were infused into rats after an intragastric glucose meal. In control rats, plasma glucose and insulin levels rose gradually during the first 20 min and then decreased. Exendin-(9-39)-NH2 administration inhibited postprandial insulin secretion by 32% at 20 min and concomitantly increased plasma glucose concentrations. In contrast, ANTGIP treatment not only induced a 54% decrease in insulin secretion but also a 15% reduction in plasma glucose levels 20 min after the glucose meal. In vivo studies in rats demonstrated that glucose uptake in the upper small intestine was significantly inhibited by the ANTGIP, an effect that might account for the decrease in plasma glucose levels observed in ANTGIP-treated rats. When the two antagonists were administered to rats concomitantly, no potentiating effect on either insulin release or plasma glucose concentration was detected. Glucose meal-stimulated GLP-1 release was not affected by ANTGIP administration, whereas postprandial glucagon levels were diminished in rats receiving exendin-(9-39)-NH2. The results of these studies suggest that GIP and GLP-1 may share a common mechanism in stimulating pancreatic insulin release. Furthermore, the GIP receptor appears to play a role in facilitating glucose uptake in the small intestine.

The roles of histidine residues at the starch-binding site in streptococcal-binding activities of human salivary amylase

Human salivary alpha-amylase participates in the initial digestion of starch and may be involved in the colonization of viridans streptococci in the mouth. To elucidate the role of histidine residues located near the starch-binding site on the streptococcal-binding activity, the wild type and three histidine mutants, H52A, H299A and H305A were constructed and expressed in a baculovirus system. While His52 is located near the non-reducing end of the starch-binding pocket (subsite S3/S4), the residues His299 and His305 are located near the subsites S1/S1'. For the wild type, the cDNA encoding the leader and secreted sequences of human salivary amylase was amplified by polymerase chain reaction from a human submandibular salivary-gland cDNA library, and subcloned into the baculovirus shuttle vector pVL1392 downstream of the polyhedrin promoter. Oligonucleotide-based, site-directed mutagenesis was used to generate the mutants expressed in the baculovirus system. Replacing His52 or His299 or His305 to Ala residue did not alter the bacterial-binding activity significantly, but these mutants did show differences in their catalytic activities. The mutant H52A showed negligible reduction in enzymatic activity compared to that of wild type for the hydrolysis of starch and oligosaccharides. In contrast, the H299A and H305A mutants showed a 12 to 13-fold reduction (90-92%) in starch-hydrolysing activity. In addition, the k(cat) for the hydrolysis of oligosaccharides by H299A decreased by as much as 11-fold for maltoheptaoside. This reduction was even higher (40-fold) for the hydrolysis of p-nitrophenyl maltoside, with a significant change in K(M). The mutant H305A, however, exhibited a reduction in k(cat) only, with no changes in the K(M) for the hydrolysis of oligosaccharides. The reduction in the k(cat) for the H305A mutant was almost 93% for maltoheptaoside hydrolysis. The pH activity profile for the H305A mutant was also significantly different from that of the wild type and the other two mutants. These results suggest that, although histidines at the starch-binding site of salivary amylase are involved in starch binding and catalysis, they may not participate in Streptococcus gordonii G9B binding.

A requirement for phosphatidylinositol 3-kinase in pseudopod extension

Phagocytosis requires actin assembly and pseudopod extension, two cellular events that coincide spatially and temporally. The signal transduction events underlying both processes may be distinct. We tested whether phagocytic signaling resembles that of growth factor receptors, which induce actin polymerization via activation of phosphatidylinositol 3-kinase (PI 3-kinase). Fcgamma receptor-mediated phagocytosis was accompanied by a rapid increase in the accumulation of phosphatidylinositol 3,4,5-trisphosphate in vivo, and addition of wortmannin (WM) or LY294002, two inhibitors of PI 3-kinase(s), inhibited phagocytosis but not Fcgamma receptor-directed actin polymerization. However, both compounds prevented maximal pseudopod extension, suggesting that PI 3-kinase inhibition produced a limitation in membrane required for pseudopod extension. Availability of plasma membrane was not limiting for phagocytosis, because blockade of ingestion in the presence of WM was not overcome by reducing the number of particles adhering to macrophages. However, decreasing bead size, and hence the magnitude of pseudopod extension required for particle engulfment, relieved the inhibition of phagocytosis in the presence of WM or LY294002 by up to 80%. The block in phagocytosis of large particles occurred before phagosomal closure, because both compounds inhibited spreading of macrophages on substrate-bound IgG. Macrophage spreading on IgG was accompanied by exocytic insertion of membrane from an intracellular source, as measured by the dye FM1-43. These results indicate that one or more isoforms of PI 3 kinase are required for maximal pseudopod extension but not phagocytosis per se. We suggest that PI 3-kinase is required for coordinating exocytic membrane insertion and pseudopod extension.