Laparoscopic suburethral sling procedure

STUDY OBJECTIVE

To describe the technique of laparoscopic suburethral sling and discuss patient satisfaction and subjective continence rates over 7 years.

DESIGN

Retrospective analysis (Canadian Task Force classification III).

SETTING

Private practice.

PATIENTS

Sixty-three consecutive patients.

INTERVENTION

Laparoscopic sling procedure using either autologous or donor fascia.

MEASUREMENTS AND MAIN RESULTS

The space of Retzius is entered laparoscopically. Then from a vaginal approach, a small midline vertical incision is made below the urethra, and vaginal epithelium is dissected off underlying periurethral and paravesical fascia. Material for the sling is passed underneath the urethra and secured laparoscopically to Cooper's ligaments bilaterally. Over 7 years, 63 laparoscopic suburethral sling procedures were performed. Overall, patients reported 88.9% satisfaction rate and 81.0% subjective continence rate.

CONCLUSION

The laparoscopic approach is an acceptable alternative to other suburethral sling procedures.

RT-PCR detection of the expression of the polymerase gene of a novel reptilian herpesvirus in tumor tissues of green turtles with fibropapilloma

An alpha-herpesvirus has recently been associated with green turtle fibropapilloma (FP). To further understand the etiological role of this newfound green turtle herpesvirus (GTHV) in the pathogenesis of FP, expression of GTHV polymerase ( pol) gene was determined in tumors and normal-appearing nontumor tissues and organs from five green turtles suffering multiple fibropapillomas, using reverse transcription-polymerase chain reaction (RT-PCR). Amplification of RNA prepared from tumor tissues evidenced the substantial expression of GTHV DNA pol gene in all specimens tested (15/15). However, GTHV pol gene expression in normal-appearing tissues and organs of affected animals was limited (4/45), and GTHV mRNA was detected only in periorbital tissue (1/2), gall bladder (2/5) and lung (1/5) by nested RT-PCR. By contrast, RT-PCR evaluation of RNA isolated from non-tumored turtles revealed undetectable expression of this herpesvirus gene. cDNA sequence analysis revealed that GTHV gene sequences were identical in different tumors. Our data represent the first evidence of the replication of this putative turtle herpesvirus in affected green turtles and fibropapilloma tissues are always active sites of GTHV mRNA synthesis. These findings extend and substantiate the pathogenic association of GTHV with FP.

Structural and biochemical evidence of mitochondrial depletion in pigs with hypertrophic cardiomyopathy

Pig hearts with naturally occurring hypertrophic cardiomyopathy (HCM) were isolated to investigate the effects of mitochondrial deficiency at biochemical and molecular levels. Enzyme activities of mitochondrial-encoded cytochrome c oxidase and NADH dehydrogenase in the HCM hearts (n=12) were lower than that in the controls (n=12) by 41+/-29% (P<0.01) and 43+/-21% (P<0.001), respectively. Additionally, Southern blot analysis was conducted to quantify the relative amount of mitochondrial DNA (mtDNA) from the HCM and controls. The relative amount of mtDNA in the HCM hearts was significantly 57+/-19% (P<0.001) lower than that in the controls. Both mitochondrial enzyme deficiency and mtDNA depletion were significantly correlated with the degree of cardiac hypertrophy judged based on the ratio of heart/body weight. In conclusion, our results reveal that a secondary effect of tissue-specific mtDNA depletion and mitochondrial dysfunction is in response to the HCM.

Laparoscopic appendectomy

STUDY OBJECTIVE

To evaluate the effectiveness of laparoscopic appendectomy in women with chronic pelvic pain and to identify histopathology of the appendix.

DESIGN

Retrospective review over 6.5 years (Canadian Task Force classification II-3).

SETTING

Laparoscopic center and community hospital.

PATIENTS

Three hundred seventeen women.

INTERVENTION

Laparoscopic appendectomy in conjunction with other procedures.

MEASUREMENTS AND MAIN RESULTS

Of 317 patients who underwent appendectomy, 14 (4.4%) had involvement of the appendix with endometriosis, 12 (3.78%) had early acute appendicitis, 4 (1.26%) had carcinoid tumors of the appendix, 2 (0.63%) had a large mucocele, and 1 (0.9%) each had Enterobius vermicularis infection, benign neuroma, and mucinous cystadenoma. Seventy-eight women (24.6%) had obliteration of the appendiceal lumen and 22 (6.93%) had entrapping fibrous adhesions. Thirty-two patients (10%) reported relief of chronic pelvic pain in the absence of other pathology just by having diagnostic laparoscopy with appendectomy.

CONCLUSION

The appendix is a key organ in the evaluation of undiagnosed chronic pelvic pain.

Minimally invasive management of urinary incontinence

Stress urinary incontinence is defined as the loss of urine at the time of an increase in abdominal pressure in the absence of a detrusor contraction. A nearly 50% prevalence of urinary incontinence in women and estimated treatment costs of more than 10 billion US dollars annually in the United States warrant an effective, successful and minimally invasive treatment. Nearly 200 different operations have been described in the literature, with cure rates reported ranging from 40% to 95%, clearly suggesting that the optimal surgical procedure has yet to be developed. Genuine stress urinary incontinence can result from either hypermobility of the bladder neck and proximal urethra or intrinsic sphincteric deficiency, which may occur alone or in combination with anatomic defects. In reviewing the recent literature and surgical modalities we present our opinion on minimally invasive surgical management of urinary incontinence.

Clinical characteristics of Group G streptococcal bacteremia in Taiwan

The results of this retrospective study showed that Group G streptococcal bacteremia was an acute febrile disease with low mortality. Most patients were > 60 y old but there was a strong association between age < 60 y and malignancy. Cases clustered in summer and the most common port of entry was the skin.

Complementary signaling pathways regulate the unfolded protein response and are required for C. elegans development

The unfolded protein response (UPR) is a transcriptional and translational intracellular signaling pathway activated by the accumulation of unfolded proteins in the lumen of the endoplasmic reticulum (ER). We have used C. elegans as a genetic model system to dissect UPR signaling in a multicellular organism. C. elegans requires ire-1-mediated splicing of xbp-1 mRNA for UPR gene transcription and survival upon ER stress. In addition, ire-1/xbp-1 acts with pek-1, a protein kinase that mediates translation attenuation, in complementary pathways that are essential for worm development and survival. We propose that UPR transcriptional activation by ire-1 as well as translational attenuation by pek-1 maintain ER homeostasis. The results demonstrate that the UPR and ER homeostasis are essential for metazoan development.

TGFbeta2 in corneal morphogenesis during mouse embryonic development

To examine the roles of TGFbeta isoforms on corneal morphogenesis, the eyes of mice that lack TGFbetas were analyzed at different developmental stages for cell proliferation, migration and apoptosis, and for expression patterns of keratin 12, lumican, keratocan and collagen I. Among the three Tgfb(-/-) mice, only Tgfb2(-/-) mice have abnormal ocular morphogenesis characterized by thin corneal stroma, absence of corneal endothelium, fusion of cornea to lens (a Peters'-like anomaly phenotype), and accumulation of hyaline cells in vitreous. In Tgfb2(-/-) mice, fewer keratocytes were found in stroma that has a decreased accumulation of ECM; for example, lumican, keratocan and collagen I were greatly diminished. The absence of TGFbeta2 did not compromise cell proliferation, nor enhance apoptosis. The thinner stroma resulting from decreased ECM synthesis may account for the decreased cell number in the stroma of Tgfb2 null mice. Keratin 12 expression was not altered in Tgfb2(-/-) mice, implicating normal corneal type epithelial differentiation. Delayed appearance of macrophages in ocular tissues was observed in Tgfb2(-/-) mice. Malfunctioning macrophages may account for accumulation of cell mass in vitreous of Tgfb2 null mice.

Phenomenology of obsessive-compulsive disorder in Taiwan

This study was designed to assess the phenomenology, comorbidities, correlation with depressive disorders, and gender differences in obsessive-compulsive disorder (OCD) in Taiwan. Two hundred outpatients who fulfilled the diagnostic criteria of OCD according to DSM-IV were included. Patient characteristics, age at onset, symptom profile, and Axis I comorbidity were recorded. Gender differences, age at onset, and comorbidity of depressive disorders among different subtypes of OCD were compared. The most common obsession was contamination, followed by pathological doubt, and need for symmetry. The most common compulsion was checking, followed by washing, and orderliness compulsions. More men than women presented with the obsession of need for symmetry. Eighty-three (41.5%) subjects had comorbid depressive disorders. Women had more major depressive disorder. Patients with somatic obsessions were more likely to have major depressive disorder. Most clinical characteristics of OCD in Taiwan were similar to that of previous studies in other countries.

Comparison and evaluation of copper complex-containing siloxane polymers as stationary phases for capillary gas chromatography

Two metallomesogenic polymers. P-C11CuC18 and P-C11CuC12 consisting of flexible aliphatic side chains with copper carboxylate complexes have been synthesized on the basis of addition reactions with polysiloxane. The applicability of the prepared columns to the analysis of phthalate esters that are of environmental concern was assessed. For preparation of the capillary column with its wall coated with the metallomesogenic polymer, both static and dynamic methods were employed. Factors affecting the retention and the sample selectivity on both columns were examined. A better separation of phthalates was achieved with P-C11CuC18 than P-C11CuC12. The former phase showed a higher solute-solvent interaction than the latter. With static coating, the wall-coated P-C11CuC18 capillary column (15 m x 250 microm I.D.) showed that the baseline separation of all 14 phthalates could be achieved within 38 min with high reproducibility. The calibration graphs for phthalate ester determination were linear over the range of 10-625 microg ml(-1). The mass detection limits were lower than the ng range based on three times the standard deviation of seven measurements of the lowest peak that could be detected.

A point mutation in the cysteine-rich domain of glycoprotein (GP) IIIa results in the expression of a GPIIb-IIIa (alphaIIbbeta3) integrin receptor locked in a high-affinity state and a Glanzmann thrombasthenia-like phenotype

This article reports a Glanzmann thrombasthenia (GT) patient, N.M., with a point mutation in the third cysteine-rich repeat of beta3-integrin or platelet glycoprotein (GP) IIIa, leading to the expression of a constitutively activated fibrinogen receptor. The diagnosis of GT was based on a severely reduced platelet-aggregation response to a series of agonists and approximately 20% of surface-expressed GPIIb-IIIa. The patient's GPIIb-IIIa constitutively expressed epitopes recognized by antibodies to ligand-induced binding sites (LIBS) and also spontaneously bound the fibrinogen-mimetic antibody, PAC-1. Furthermore, significant amounts of bound fibrinogen were detected on his platelets ex vivo. No signs of platelet activation were observed on sections of unstimulated platelets from N.M. by electron microscopy. Immunogold labeling highlighted the presence of surface-bound fibrinogen but revealed platelet heterogeneity with regard to the surface density. When the patient's platelets were stimulated by thrombin-receptor activating peptide, amounts of surface-expressed GPIIb-IIIa increased and the aggregation response improved, although it failed to normalize. Platelets from N.M. were able to adhere and spread on immobilized fibrinogen. Sequence analysis of genomic DNA from N.M. revealed a homozygous g1776T>C mutation in GPIIIa, leading to a Cys560Arg amino acid substitution. A stable Chinese hamster ovary (CHO) cell line was prepared expressing surface GPIIb-Arg560IIIa. Like platelets from the patient, GPIIb-Arg560IIIa-transfected CHO cells constitutively bound LIBS antibodies and PAC-1. They also showed an enhanced ability to adhere on surface-bound fibrinogen. Overall, these data demonstrate that a gain-of-function mutation can still be associated with a thrombasthenic phenotype even though platelets show spontaneous fibrinogen binding.

Up-regulation of Fas ligand expression by human cytomegalovirus immediate-early gene product 2: a novel mechanism in cytomegalovirus-induced apoptosis in human retina

Human CMV (HCMV) is an important pathogen that causes widespread diseases in immunocompromised individuals. Among the opportunistic HCMV infections, HCMV retinitis is most common in transplant recipients and AIDS patients. It often leads to blindness if left untreated. The question as to how HCMV infection causes retinal pathogenesis remains unresolved. Here, we report that viral immediate-early gene product 2 (IE2), but not IE1, up-regulates the Fas ligand (FasL) expression in HCMV-infected human retinal pigment epithelium cells. Increased secretion of FasL from virally infected cells into cultured medium was observed upon HCMV infection. The capability of such cell-free medium to induce apoptosis of Fas (CD95)-expressing Jurkat cells further implies that Fas-FasL interaction might mediate cell death in the lesion of HCMV retinitis. To support this idea, we observed augmented soluble FasL levels in vitreous from AIDS patients with HCMV retinitis as compared with that from AIDS patients without HCMV infection. In addition, by in situ hybridization and immunohistochemistry, we detected enhanced signals of FasL, the existence of viral IE Ags and apoptotic cells at the same sites in the lesion of HCMV-infected retina. These results strongly suggest that IE2 induction of FasL expression in human retina might be an important event that takes place in the early stage of infection and finally leads to visual loss in individuals affiliated with HCMV retinitis.

2001: Things to come

THIS ARTICLE DISCUSSES elements in the definition of modernity and emerging futurism in neurological surgery. In particular, it describes evolution, discovery, and paradigm shifts in the field and forces responsible for their realization. It analyzes the cyclical reinvention of the discipline experienced during the past generation and attempts to identify apertures to the near and more remote future. Subsequently, it focuses on forces and discovery in computational science, imaging, molecular science, biomedical engineering, and information processing as they relate to the theme of minimalism that is evident in the field. These areas are explained in the light of future possibilities offered by the emerging field of nanotechnology with molecular engineering.

Comparative study of ceftibuten and cefixime in the treatment of complicated urinary tract infections

Between August 1996 and May 1998, a total of 62 patients who had complicated urinary tract infections treated at the Taipei Veterans General Hospital were enrolled into this study. This prospective, randomized, open-labeled trial aimed at comparing the efficacy and safety of ceftibuten and cefixime, prescribed each at a dose of 200 mg twice daily, in treating complicated urinary tract infection. Seventeen patients were later excluded from the analysis because of resistant pathogens (7 patients), uncomplicated urinary tract infection (6), initial culture negative for bacteria (3), and infective endocarditis (1). The remaining 45 patients were categorized into ceftibuten (n=23; mean age, 71.3 years) and cefixime (n=22; mean age, 62.8 years) treatment groups. No significant difference in demographic data and clinical characteristics was found between the 2 groups. The clinical efficacy rate (78.3% vs 77.3%, p=0.9) and bacteriological eradication rate (52.2% vs 63.6%, p=0.08) were similar between the ceftibuten and the cefixime group. Adverse effects caused by ceftibuten treatment included diarrhea and slight elevation of the serum level of liver transaminase in 2 (6.5%) patients. Those caused by cefixime treatment included slight elevation of serum level of liver transaminase in 2 (6.5%) patients and skin rash in 1 (3.2%) patient. All of these adverse effects resolved quickly after the regimen had been completed, and no patient discontinued the regimen because of the adverse effects. The results suggest that oral administration of ceftibuten 200 mg twice daily is as effective and safe as oral administration of cefixime 200 mg twice daily in the treatment of complicated urinary tract infections.

Characteristics of patients with Burkholderia cepacia bacteremia

Burkholderia cepacia has become an important pathogen of infections in immunocompromised and nosocomial patients. The characteristics of 42 episodes of B. cepacia bacteremia in 40 patients admitted to the Taipei Veterans General Hospital between January 1997 and December 1999 were retrospectively analyzed. Factors that adversely influenced the mortality rate included respiratory failure, an unknown infection source, a period in an intensive care unit, and shock. Most of the patients had serious underlying diseases, such as diabetes mellitus, malignancy, congestive heart failure, and chronic obstructive pulmonary disease. The mean time for a positive blood culture was 45 days after admission. The overall mortality rate was 28.6% (12/42), and 44.4% (12/27) of all deaths were directly related to B. cepacia bacteremia. Polymicrobial bacteremia was found in 5 patients. Ceftazidime was the most effective antimicrobial agent in vitro, whereas chloramphenicol, imipenem, and trimethoprim/sulfamethoxazole were less effective alternatives. Appropriate antibiotic therapy was given to 30 patients, most of whom responded to the therapy except for 5 who died despite receiving appropriate treatment. Although B. cepacia infection develops in a relatively small proportion of hospitalized individuals, it has a major impact on morbidity and mortality. In view of the fact that B. cepacia develops resistance to a wide range of antimicrobial agents, ceftazidime and/or trimethoprim/sulfamethoxazole should be the drug of choice for empiric therapy.

Remediation of TCE contaminated soils by in situ EK-Fenton process

The treatment performance and cost analysis of in situ electrokinetic (EK)-Fenton process for oxidation of trichloroethylene (TCE) in soils were evaluated in this work. In all experiments, an electric gradient of 1V/cm, de-ionized water as the cathode reservoir fluid and a treatment time of 10 days were employed. Treatment efficiencies of TCE were evaluated in terms of the electrode material, soil type, catalyst type, and catalyst dosage and granular size if applicable. Test results show that graphite electrodes are superior to stainless steel electrodes. It was found that the soil with a higher content of organic matter would result in a lower treatment efficiency (e.g. a sandy loam is less efficient than a loamy sand). Experimental results show that the type of catalyst and its dosage would markedly affect the reaction mechanisms (i.e. "destruction" and "removal") and the treatment efficiency. Aside from FeSO4, scrap iron powder (SIP) in the form of a permeable reactive wall was also found to be an effective catalyst for Fenton reaction to oxidize TCE. In general, the smaller the granular size of SIP, the lower the overall treatment efficiency and the greater the destruction efficiency. When a greater quantity of SIP was used, a decrease of the overall treatment efficiency and an increase of percent destruction of TCE were found. Experimental results have shown that the quantity of electro-osmotic (EO) flow decreased as the quantity of SIP increased. It has been verified that the treatment performances are closely related to the corresponding EO permeability. Results of the cost analysis have indicated that the EK-Fenton process employed in this work is very cost-effective with respect to TCE destruction.

Association analysis of the 5-HT6 receptor polymorphism C267T with depression in patients with Alzheimer's disease

A significant increase of 267C allele of the 5-HT(6) receptor gene has been reported in patients with Alzheimer's disease (AD). Because a deficit in serotonergic neurotransmission is involved in major depression, we tried to find out whether 267C allele is associated with depressive disorders in AD. A psychiatrist interviewed all AD patients and their caregivers for evidence of depression using a Chinese version of the Standard Clinical Interview for DSM-III-R. The difference in the 5-HT(6) genotype or allele distributions between the AD patients with depressive disorders (n = 25) and those without (n = 120) was not significant.

Laparoscopic ureteroureteral anastomosis on the distal ureter

Repair of ureteral injury involving the distal ureter traditionally required laparotomy. Ureteroureteral anastomosis is not usually advocated due to technical difficulties and poor outcomes. Laparoscopy overcomes these difficulties and allows correction of distal ureteral injuries.

Histidine-functionalized silica and its copper complex as stationary phases for capillary electrochromatography

A histidine-functionalized silica was prepared by covalent bonding of the functional groups to silane-treated silica gel. Conversion of functional groups was confirmed by infrared (IR) spectra, elemental analysis, and potentiometry. The functionality of the silica gel is 0.293 mmol g(-1). The coordination behavior of the histidine-functionalized silica was investigated by metal capacity and electron paramagnetic resonance (EPR). EPR measurements at different copper loadings were made. The results showed that the copper histidine complex might be distorted tetragonal. Both histidine-functionalized silica and its copper complex were employed as stationary phases for packed capillary electrochromatography (CEC). Electrical current was found helpful for evaluating the properties of frit construction and the stationary phase packing. Test samples include neutral compounds, inorganic anions and organic anions. Factors influencing the separation behavior have been studied. With copper-histidine functionalized silica under the condition of citrate buffer (10 mM, pH 4.0) and applied voltage of -20 kV, the separation of benzoic acid, D- and L-mandelic acid, phthalic acid and salicylic acid could be achieved within 12 min. The column efficiency for these acids was more than 1.2 x 10(5) plates m(-1), except salicylic acid.

Correlation of panic attacks and hostility in chronic schizophrenia

The aim of this study was to investigate the relationship between panic attacks and hostility in patients with chronic schizophrenia. Thirty-two patients with a minimum 2-year history of treatment for schizophrenia were interviewed. The patients took mood stablizers lithium, carbamazepine and valproate adjunctively for hostility and anger attacks. Panic attacks were defined by Structure Clinical Interview of DSM-IV. Severity of psychopathology was assessed by the Hamilton Depression Rating Scale (HDRS) and Brief Psychiatric Rating Scale (BPRS). Functional level was assessed by the Global Assessment of Functioning Scale (GAF). Eight (25%) patients met the diagnostic criteria for panic attacks (DSM-IV) with affective symptoms including hostility and sudden spells of anger. Their HDRS scores were significantly higher (P < 0.01), and GAF scores were significantly lower (P < 0.05) than those of patients without panic attacks. Patients with panic attacks displayed significantly higher hostility in the score of the BPRS (P = 0.01). Those who received higher doses of neuroleptics were more likely to be considered hostile. Multivariate analysis revealed that panic attacks were correlated with more severe depression, greater hostility and lower GAF scores. The results suggest that increased hostility and anger spells may be symptoms of panic attacks, which are overlooked by psychiatrists.

Stationary phases for capillary electrophoresis and capillary electrochromatography

An overview of the most recent developments in column technology employed in capillary electrophoresis (CE) and capillary electrochromatography (CEC), mainly for the separation of small molecules and ions, is presented. Particular emphasis is laid on permanent coating. The wall modification methods in CE include covalent modification, adsorbed coatings and polymeric coatings, while those in CEC include packed columns, open-tubular columns and fritless columns. A short discussion on the characterization and selectivity of the bonded phases is also given.

[Effect of nucleus raphe obscurus on myoelectric activity of sphincter of Oddi in rabbits]

The aim of the present study was to investigate the role of nucleus raphe obscurus (NRO) in regulating the motility of sphincter of Oddi (SO). After fasting about l8~24 h, the rabbits were anesthetized with urethane (1.0 g/kg), and the myoelectric signals of SO were induced by a pair of copper electrodes inserted into the subsera. The results of microinjection of various drugs into NRO are as follows. After glutamate (340 mmol/L, 0.1 microl) was injected, activity of SO was excited. With microinjection of GABA (1 mol/L,0.1 microl), the spike burst of SO was inhibited. Following microinjection of ketamine (180 mmol/L, 0.1 microl), a kind of N-methyl-D-aspartate (NMDA) receptor antagonist, SO motility was inhibited and the effect of glutamate was abolished. Injection of 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX) (2 mmol/L, 0.1 microl), a non-NMDA receptor antagonist, also excited the myoelectric activity of SO, but did not inhibit the effect of glutamate. The effect of glutamate was abolished by intravenous injection of atropine (0.2 mg/kg) or bilateral vagotomy, but not by injection of phentolamine (1.5 mg/kg) or propronalol (1.5 mg/kg), or by transection of the spinal cord. The above results indicate that NRO mediation of SO activity is due to the effect of glutamate on the NMDA receptors in the nucleus, the output of which is sent through vagal nerve and peripheral M cholinergic receptor to exert excitation of gallbladder motility.

Cross-cultural implementation of a Chinese version of the Schedules for Clinical Assessment in Neuropsychiatry (SCAN) in Taiwan

BACKGROUND

There are no published reports of cross-cultural equivalence and interrater reliability at the level of individual symptom items assessed by a semi-structured clinical interview employing operationalised clinician ratings.

AIMS

To assess the cross-cultural clinical equivalence and reliability of a Chinese version of the World Health Organization Schedules for Clinical Assessment in Neuropsychiatry (SCAN).

METHOD

UK-US and Taiwanese groups of psychiatrists used Chinese and English transcripts of videotape interviews of Taiwanese patients to discuss cross-cultural issues and ratings of SCAN items. Item ratings were compared quantitatively individually and pooled by SCAN section.

RESULTS

Chinese equivalents were found for all SCAN items. No between-group differences were found for most individual items, but there were differences for some scaled items. Average agreement between the two groups was 69-100%.

CONCLUSIONS

Cross-cultural implementation based on SCAN in Taiwan appears valid.

Investigation of an outbreak caused by methicillin-resistant Staphylococcus aureus in a cardiovascular surgery unit by ribotyping, randomly amplifed polymorphic DNA and pulsed-field gel electrophoresis

An outbreak caused by rapid spread of methicillin-resistant Staphylococcus aureus (MRSA) in an intensive care unit for cardiovascular surgery was investigated by phenotypic and genotypic methods. Fourteen isolates were collected during a 2-month period from clinical and environmental specimens in the unit recently re-opened after reconstruction. The isolates were tested for antibiotic susceptibility patterns and genotyped by automated ribotyping, randomly amplified polymorphic DNA-PCR (RAPD) analysis and pulsed-field gel electrophoresis (PFGE). Automated ribotyping applying EcoRI digestion proved to be of no value in separating the isolates. In contrast, PFGE grouped the isolates into four clusters different from the reference strain. These results fully correlated with the antibiograms. Twelve of the isolates were grouped into two clonally related clusters. RAPD analyses grouped the isolates into five clusters. Except for two isolates of one patient, which had different RAPD patterns, PFGE and RAPD analyses presented very similar results. The results verified the usefulness of PFGE in studies of MRSA epidemics. A combination of these two methods reduces the time to identification of an outbreak and increases the accuracy in detection of intraspecies differences.

MK/T-1, an immortalized fibroblast cell line derived using cultures of mouse corneal stroma

PURPOSE

Immortalized cell lines representing fibroblast cells from corneal stroma would facilitate studies of corneal cell biology and injury response.

METHODS

Primary cultures of cells derived from mouse corneal stroma were transfected with a human telomerase reverse transcriptase (hTERT) expression construct to maximize chances of cellular immortalization. A resulting cell line was analyzed for telomerase activity, cell growth characteristics, senescence and gene expression patterns. Specific responses to transforming growth factor beta (TGF-beta) were also analyzed.

RESULTS

An immortalized cell line was derived and was named MK/T-1. MK/T-1 cells show no signs of cellular senescence or transformation at over 100 passages. Telomerase activity was significantly higher in MK/T-1 cells as compared to the parental cell cultures. However, relative telomere length (RTL) in the MK/T-1 and parental cells was not significantly different. Senescence associated beta-galactosidase (SA-beta-Gal) activity was not detected in late passage MK/T-1 cells while the parental cells had already upregulated SA-beta-Gal at high levels by passage 9. The MK/T-1 cells express vimentin, tubulin, lumican, mimecan, decorin and collagen I, but not keratocan. Exposure of the MK/T-1 cells to TGF-beta induces the expression of smooth muscle alpha-actin (ASMA), the activation of MAP Kinase (p38-MAPK) and morphological changes consistent with cytoskeletal reorganization.

CONCLUSIONS

MK/T-1 cells represent an immortalized fibroblast cell line derived using cultures from corneal stroma cell preparations. Expression of hTERT may contribute to immortalization of the MK/T-1 cells by a mechanism other than increases in RTL. MK/T-1 cells may be a useful model in which to study the responses of corneal fibroblast cells to cytokines and other diverse environmental factors in vitro.

Kinetics of methyl t-butyl ether cometabolism at low concentrations by pure cultures of butane-degrading bacteria

Butane-oxidizing Arthrobacter (ATCC 27778) bacteria were shown to degrade low concentrations of methyl t-butyl ether (MTBE; range, 100 to 800 microg/liter) with an apparent half-saturation concentration (K(s)) of 2.14 mg/liter and a maximum substrate utilization rate (k(c)) of 0.43 mg/mg of total suspended solids per day. Arthrobacter bacteria demonstrated MTBE degradation activity when grown on butane but not when grown on glucose, butanol, or tryptose phosphate broth. The presence of butane, tert-butyl alcohol, or acetylene had a negative impact on the MTBE degradation rate. Neither Methylosinus trichosporium OB3b nor Streptomyces griseus was able to cometabolize MTBE.

Occurrence of fumonisin B1 in maize imported into Taiwan

Samples of maize imported into Taiwan during 1997-1998 were collected and analyzed for the presence of fumonisin B1 (FB1) using high performance liquid chromatography. Eight (6.8%) of 118 samples were found to contain FB1 (334-1614 microg kg(-1)). The frequency of FB1 found in maize samples imported from Australia was 20%, followed by Thailand (10%), and USA (5.1%). In analyzing the distribution pattern, it was found that 93.2% of the samples had FB1 concentrations below 100 microg kg(-1), and only 3.4% (or four samples) were in excess of 300 microg kg(-1).

Risk factors of catheter-related infections in total parenteral nutrition catheterization

BACKGROUND

The use of central venous catheter for administration of total parenteral nutrition (TPN) is a risk factor of catheter-related infections (CRIs) that are associated with increased morbidity and mortality, prolonged hospitalization, and increased medical costs. The purpose of this study is to evaluate the risk factors of CRIs in patients with administration of TPN.

METHODS

A total of 1134 patients receiving TPN between January, 1996 and December, 1998 were studied. The category of infection included definite catheter-related bloodstream infection (CR-BSI), probable CR-BSI, and insertion site infection. Statistical analysis of risk factors was performed.

RESULTS

A total of 131 episodes of CRI occurred, representing an infection rate of 11.46%. Ninety-three episodes (8.1%) had probable CR-BSI, 13 episodes (1.1%) had definite CR-BSI, and 25 episodes (2.2%) had insertion site infection. Duration of TPN infusion and frequency of catheter insertion showed statistically significant difference by logistic regression multivariate analysis. The isolated organisms were in sequence of coagulase-negative Staphylococci (19.4%), Staphylococcus aureus (17.2%) and Candida albicans (14.4%).

CONCLUSIONS

Risk factors influencing the occurrence of CRI in TPN administration were multifactorial; however, duration of TPN infusion and frequency of catheter insertion were the main factors in our study.

Incineration of paper sludge in a prototype vortexing fluidized bed combustor

All experiments were carried out in a prototype vortexing fluidized bed combustor (VFBC). The dimension of the combustion chamber is 0.7 x 1.4 x 2 m, and the freeboard section is 1 m i.d. and 4 m in height. Paper sludge was used as the feeding material. Two types of coal particles were employed as the supplementary fuel. In order to understand the characteristics of the VFBC system for paper sludge incineration, the effect of various operating parameters, such as the primary airflow, excess air ratio, and secondary airflow rates, on temperature distribution, ash elutriation, combustion efficiency, and pollutant emissions were investigated.

Upregulation of inducible nitric oxide synthase and cytokine secretion in peripheral blood monocytes from pulmonary tuberculosis patients

SETTING

Peripheral blood monocytes (PBM) are the main source of alveolar macrophages, which have an upregulation of inducible nitric oxide synthase (iNOS) in pulmonary tuberculosis (TB). TNF-alpha and IL-1 beta are thought to be involved in the immune response to mycobacterial infection.

OBJECTIVE

To identify whether iNOS expression and cytokine release of PBM are upregulated and have a connection in TB infection.

DESIGN

The expression of iNOS immunoreactivity on PBM from TB patients and normal subjects was measured by loading with anti-macrophage iNOS polyclonal primary antibody analyzed by flow cytometry. Expression of iNOS mRNA in PBM was detected by RT-PCR. The spontaneous generation of nitrite and cytokines (IL-1 beta and TNF-alpha) by cultured monocytes was also determined.

RESULTS

Compared to normal subjects, iNOS immuno-reactivity, the capacity for spontaneous nitrite generation and the level of TNF-alpha or IL-1 beta secretion of PBM were significantly higher in TB patients. The amount of nitrite, TNF-alpha and IL-1 beta released from PBM of TB patients was inhibited by NG-monomethyl-L-arginine (L-NMMA), a competitive inhibitor of NOS. The level of iNOS immunoreactivity on PBM was highly correlated with nitrite generation both in all the subjects studied and in TB patients alone. Spontaneous TNF-alpha production showed a stronger correlation with nitrite production than with IL-1 beta.

CONCLUSION

The NO and cytokine synthase activities of monocytes appear to be concomitantly upregulated in response to mycobacterial infection. The enhanced NO generation by monocytes in TB patients may play an autoregulatory role in amplifying the synthesis of pro-inflammatory cytokines.

Comparison of aerobic denitrification under high oxygen atmosphere by Thiosphaera pantotropha ATCC 35512 and Pseudomonas stutzeri SU2 newly isolated from the activated sludge of a piggery wastewater treatment system

AIMS

This study compares the ability of Thiosphaera pantotropha ATCC 35512 and the newly isolated Pseudomonas stutzeri SU2 to perform aerobic denitrification.

METHODS AND RESULTS

Nitrate-supplemented basal medium in airtight crimp-sealed serum bottles containing an atmosphere of 92% oxygen was inoculated with Ps. stutzeri SU2 or T. pantotropha and incubated at 30 degrees C. During the 92-h incubation period, aerobic denitrification by Ps. stutzeri SU2 (NO3(-) - N removal 99.24%) was more efficient than that by T. pantotropha (NO3(-) - N removal 27.29%).

CONCLUSION

Pseudomonas stutzeri SU2, which was isolated from the activated sludge of a sequencing batch reactor treating piggery wastewater, rapidly reduced the nitrate to nitrogen gas without nitrite accumulation. The nitrate removal rate of SU2 was 0.032 mmol NO3(-) - N g cell-1 h-1 after 44 h incubation.

SIGNIFICANCE AND IMPACT OF THE STUDY

Pseudomonas stutzeri SU2 can be used in a full-scale sequencing batch system for efficient in situ aerobic nitrate removal from piggery wastewater.

Anticoagulation therapy for radiation-induced myelopathy

OBJECTIVE

To report the use of heparin and enoxaparin for radiation-induced myelopathy.

CASE SUMMARY

A 48-year-old White woman with presumed metastatic lung cancer presented with worsening numbness and weakness of both legs. The neuro-oncology service was consulted and determined that the symptoms were consistent with radiation-induced myelopathy. The patient briefly responded to steroid treatment. A trial of intravenous heparin therapy was initiated by the primary team and managed by the clinical pharmacy services. Her symptoms improved when heparin was begun. She was able to walk and was subsequently discharged home on enoxaparin.

DISCUSSION

Spinal cord injury is one of the known adverse effects of radiation. The onset of symptoms can be acute or delayed. The clinical signs and symptoms of delayed neurologic injury are related to the narrowing and occlusion of the vessel lumen, ischemia, edema, and cell death in the surrounding nervous tissue. Treatment often consists of corticosteroids and/or hyperbaric oxygen; however, the outcomes are often disappointing. In addition to the inhibition of serum protein-mediated coagulation, heparin inactivates or prevents the release of mediators of vascular injury inflammation, permeability, and edema. Therefore, patients with radiation-induced spinal cord injury may benefit from anticoagulant therapy.

CONCLUSIONS

Heparin and/or enoxaparin may be considered as potential treatments for patients with radiation-induced myelopathy.

[Clinical study on treatment of exogenous infection caused fever by infantile umbilical paste]

OBJECTIVE

To observe the effect of infantile umbilical paste (IUP) in abating infantile fever.

METHODS

Two hundred and twenty cases were randomly divided into two groups, the 120 cases in Group A were treated with IUP and the 100 cases in Group B treated with compound Aspirin (APC). The effect in abating fever and side-effects were observed.

RESULTS

The total effective rate of the two groups were not statistically different (P > 0.05). But a better effect in abating fever was shown in Group A 4 hrs later (P < 0.01). The effect in patients of age under 1 year was the best.

CONCLUSION

IUP has good effect in abating infantile fever, and it shows no influence on white blood cells, liver and kidney functions.

Meperidine addiction or treatment frustration?

There have been few studies of the psychiatric characteristics of analgesics addiction. The physician's perceptions that patients were addicted to analgesics might be partially attributable to frustration with poor response to treatment. In this retrospective study, we evaluated the medical records of 20 subjects (15 male and 5 female) who were perceived as having addiction to meperidine by general physicians. The most common medical diagnosis among these patients was chronic pancreatitis (7/20). Among them, five had a past history of suicide attempt and three had self-injury behavior during the index admission. The fact that subjects were perceived as being addicted might be attributable to a vicious cycle of the following factors: 1) chronic intractable pain; 2) poor staff-patient relationship; 3) lower pain threshold or tolerance due to anxiety or depression; 4) patients with a history or tendency of substance abuse; 5) placebo use and inadequate analgesics regimen. The findings of this study suggest that the importance of the following diagnostic and treatment procedures in these patients: 1) suicide risk should be evaluated; 2) comorbid psychiatric diseases should be treated; 3) factors that cause a vicious cycle in pain control should be identified; 4) misconceptions of opiate analgesics among medical staff should be discussed; 5) poor staff-patient relationship should be managed aggressively; and 6) "addiction" is a critical diagnosis that should be avoided if possible.

Effects of the type of sintering atmosphere on the chromium leachability of thermal-treated municipal solid waste incinerator fly ash

The sintering process offers an opportunity to combine detoxification and resource recovery for the treatment of municipal solid waste (MSW) incinerator fly ash. However, the chromium (Cr) in the sintered fly ash becomes more readily leachable with increasing sintering time and temperature, thus posing severe threats to the environment and human health when the sintered ash is recycled or reused. This study investigated the enhanced leachability of fly ash containing Cr, by heating the chromium (III) oxide (Cr2O3)-spiked fly ash to 800 degrees C in atmospheres containing air, nitrogen gas (N2), and 5% H2 + 95% N2, respectively. The results indicated that trivalent chromium was converted to its soluble hexavalent form during sintering in the air atmosphere; whereas sintering in a nitrogen atmosphere significantly reduced the leachability of Cr due to lack of oxygen (O2) to oxidize. The effects of the sintering temperature on the total chromium content and the leaching concentration in the toxicity characteristic leaching procedure (TCLP) extract are also discussed.

Analysis of the human lumican gene promoter

The human lumican gene was shown to possess one major transcription start site, resulting in exon 1 of the gene giving rise to the first 74 base pairs (bp) of the 5'-untranslated region. About 1.6 kilobase pairs of upstream promoter sequence were sequenced and analyzed to identify elements responsible for gene expression. No typical TATAA sequence was identified in the vacinity of the transcription start site, but an atypical TATCA sequence residing 41 bp upstream was shown to be necessary for transcription, although it was incapable of supporting transcription by itself. A GC box residing 74 bp upstream of the transcription start site also was essential for the initiation of transcription. Sp3 was identified as the transcriptional activator binding to the GC box. No additional elements that significantly modulated transcription were noted in the promoter sequence analyzed, when using human adult chondrocytes as the cell source for transfection in reporter assays. In contrast, reporter assays carried out in human fetal lung fibroblasts, where lumican expression is deplete, revealed the presence of a repressor element located between 384 and 598 bp upstream of the transcription start site. A GATA-binding site located between bp -386 and -391 was identified as being necessary for repression of transcription. The mouse lumican promoter does not possess an equivalent site, and this may explain why the lumican gene is expressed in fetal murine cartilage but not in fetal human cartilage.

Using buffy coat for reverse transcriptase-polymerase chain reaction in the diagnosis of dengue virus infection: preliminary study

Using reverse transcriptase-polymerase chain reaction (RT-PCR) to detect and type from viremic human serum samples for dengue virus infection is widely used today. However, a few false-negative results were reported due to very low titers of the virus particle in serum samples. As mononuclear cells, macrophages or monocytes are target cells for dengue virus infection, and the replication of virions can be observed in peripheral leukocytes frequently, the amount of virus particle in buffy coat should be higher than those in serum samples. Here, we describe a procedure in which RNA extraction from the buffy coat of a patient with a false-negative serum sample yielded specific viral RNA amplifiable by RT-PCR, thereby providing an alternative choice for the accurate diagnosis of dengue infection.

Preparation and evaluation of an imidazole-coated capillary column for the electrophoretic separation of aromatic acids

An imidazole-coated capillary column for electrophoresis has been prepared by means of organosilanization. With mesityl oxide as neutral marker, the results indicated that the electroosmotic flow of the bonded phase displays a dramatic difference in pH dependence in comparison with that of the bare fused-silica column. The presence of positive charges on the coating surface and the anionic exchange property, due to the cationic property of the imidazole group at pH values below 6, allows the separation of geometric isomers that are very similar in ionic mobility. Separation parameters including buffer composition and concentration, pH, applied voltage, and the influence of other additives were investigated. By using acetate buffer (100 mM, pH 5.2) and an applied voltage of -15 kV with UV detection at 212 nm, the separation of 11 aromatic acids including mono-, di-, tri- and tetra-carboxylic acids could be achieved in less than 14 min. The average plate number was 3 x 10(5)/m. With acetate buffer (25 mM, pH 5.5) and an applied voltage of -25 kV, the addition of silver nitrate or beta-cyclodextrin significantly improved the resolution of some more highly charged carboxylic acids.

[The vagus nerve coordinates the motion of gallbladder and sphincter of Oddi in the interdigestive period in rabbits]

AIM

To investigate the effect of vagus nerve on coordinating the motion of gallbladder (GB) and sphincter of Oddi (SO) in the interdigestive period in rabbits.

METHODS

Fasted for 15 h-18 h, but allowed to drink water, the rabbib were anesthetized with urethane (1.0 mg/kg, i.v.). In order to measure GB pressure, a frog bladder filled with normal saline was put into GB and connected to a transducer (TP-200T). Myoelectric signals of SO was recorded by a pair of copper electrodes.

RESULTS

In the interdigestive period, phasic contractions of GB (PCGB) and clusters of spike potentials of SO (CSPSO) was 1:1 correlated (Y = 0.962X + 0.587, r = 0.982, P < 0.01). That is, every PCGB was accompanied by one CSPSO. Microinjection of thyrotropin-releasing hormone (TRH, 0.8 nmol, 1 microliter) or monosodium glutamate (MSG, 2 mumol, 1 microliter) into dorsal vagal complex (DVC) enhanced the motility of GB and SO, and the 1:1 temporal relation between PCGB and CSPSO still existed. Vagotomy or intravenous injection of atropine inhibited the PCGB and the spike potentials of SO, and the 1:1 correlation between PCGB and CSPSO disappeared. The spike bursts of SO did not respond to the artificial rise of gallbladder pressure.

CONCLUSION

In the interdigestive period in rabbits, gallbladder and SO contract and relax rhythmically and simultaneously. This eoordinated motion between GB and SO is controlled by DVC via vagus nerve and peripheral M receptors.

Analysis of sharp-edged medical-object injuries at a medical center in Taiwan

A total of 733 incidents by sharp-edged objects occurred among healthcare workers between 1995 and 1998. Injuries occurred most frequently among interns. The workplace location with the highest incidence of injury was the patient ward, and the object that most frequently inflicted injury was a needle. The most frequent work practice was recapping of syringes. One healthcare worker demonstrated seroconversion for hepatitis C.

Klebsiella pneumoniae renal abscess

BACKGROUND

The clinical characteristics of renal abscess caused by Klebsiella pneumoniae have not been previously reported in case-series studies. The purpose of this study is to demonstrate the clinical characteristics of K pneumoniae renal abscess for early diagnosis and to identify the clinical risk factors associating with poor prognosis.

METHODS

We retrospectively reviewed the medical records of 24 patients with K pneumoniae renal abscess, from April, 1982 through February, 1998. The clinical presentations, including the demographic characteristics, predisposing disorders, initial signs and symptoms, laboratory test results, diagnostic radiology studies, therapeutic modalities and risk factors associated with mortality were studied.

RESULTS

The mean age was 58.7 years and the male to female ratio was 10:14. The most common predisposing factors were diabetes mellitus (58%), urolithiasis (25%) and immunosuppression (17%). Fever, chills and flank pain were the most common symptoms and signs, whereas pyuria, elevation of leukocyte count, glucose, blood urea nitrogen and creatinine were the common laboratory features. The distinct complications of K pneumoniae renal abscess were bacteremia in 13 (54%), emphysematous pyelonephritis in five (21%), and metastatic septic infection in three (12.5%). The cure rate was 52% (11/21) in patients treated with a combination of antibiotics and percutaneous drainage; however, six (35%) patients who survived required another surgical procedure for complete recovery. The overall mortality rate was 25%. The clinical factors of elderly age (>65 years) at presentation, lethargy, elevation of serum blood urea nitrogen and pulmonary complications were associated with poor prognoses.

CONCLUSIONS

Focusing on the early diagnosis of K pneumoniae renal abscess and recognition of the prognostic factors for a poor prognosis, we highlight the specific clinical characteristics that include elderly age, lethargy, impairment of renal function, metastatic septic lesions and pulmonary complications. All patients with K pneumoniae renal abscesses should receive empiric antibiotics and percutaneous drainage or aspiration, and surgical intervention as necessary for patients with intractable disease.

An Update on Laparoscopic Hysterectomy and Pelvic Floor Reconstruction

Laparoscopic hysterectomy and pelvic floor reconstruction have recently undergone some degree of evolution. New instrumentation has appeared, such as the vaginal delineator, but overall most of the instruments used have remained basically unchanged. This is related mostly to the need of keeping costs down by limiting the use of disposable instrumentation. For pelvic reconstruction, the laparoscopic approach is now usually considered the optimal approach, as it allows the surgeon to visualize structures that the vaginal surgeon could in the past only palpate.

Intra- and extracellular measurement of reactive oxygen species produced during heat stress in diaphragm muscle

Skeletal muscles are exposed to increased temperatures during intense exercise, particularly in high environmental temperatures. We hypothesized that heat may directly stimulate the reactive oxygen species (ROS) formation in diaphragm (one kind of skeletal muscle) and thus potentially play a role in contractile and metabolic activity. Laser scan confocal microscopy was used to study the conversion of hydroethidine (a probe for intracellular ROS) to ethidium (ET) in mouse diaphragm. During a 30-min period, heat (42 degrees C) increased ET fluorescence by 24 +/- 4%, whereas in control (37 degrees C), fluorescence decreased by 8 +/- 1% compared with baseline (P < 0.001). The superoxide scavenger Tiron (10 mM) abolished the rise in intracellular fluorescence, whereas extracellular superoxide dismutase (SOD; 5,000 U/ml) had no significant effect. Reduction of oxidized cytochrome c was used to detect extracellular ROS in rat diaphragm. After 45 min, 53 +/- 7 nmol cytochrome c. g dry wt(-1). ml(-1) were reduced in heat compared with 22 +/- 13 nmol. g(-1). ml(-1) in controls (P < 0.001). SOD decreased cytochrome c reduction in heat to control levels. The results suggest that heat stress stimulates intracellular and extracellular superoxide production, which may contribute to the physiological responses to severe exercise or the pathology of heat shock.

An analysis of the interaction between mouse apolipoprotein B100 and apolipoprotein(a)

The assembly of lipoprotein(a) (Lp(a)) involves an initial noncovalent interaction between apolipoprotein (apo) B100 and apo(a), followed by the formation of a disulfide bond between apoB100 cysteine 4326 and apo(a) cysteine 4057. The structural features of apoB100 that are required for its noncovalent interaction with apo(a) have not been fully defined. To analyze that initial interaction, we tested whether apo(a) could bind noncovalently to two apoB proteins that lack cysteine 4326: mouse apoB100 and human apoB100-C4326G. Our experiments demonstrated that both mouse apoB and the human apoB100-C4326G bind noncovalently to apo(a). We next sought to gain insights into the apoB amino acid sequences required for the interaction between apoB100 and apo(a). Previous studies of truncated human apoB proteins indicated that the carboxyl terminus of human apoB100 (amino acids 4330-4397) is important for Lp(a) assembly. To determine whether the carboxyl terminus of mouse apoB100 can interact with apo(a), transgenic mice were produced with a mutant human apoB gene construct in which human apoB100 amino acids 4279-4536 were replaced with the corresponding mouse apoB100 sequences and tyrosine 4326 was changed to a cysteine. The mutant apoB100 bound to apo(a) and formed bona fide disulfide-linked Lp(a), but Lp(a) assembly was less efficient than with wild-type human apoB100. The fact that Lp(a) assembly was less efficient with the mouse apoB sequences provides additional support for the notion that sequences in the carboxyl terminus of apoB100 are important for Lp(a) assembly.

The induction of congenital spinal deformities in mice by maternal carbon monoxide exposure

Carbon monoxide (CO) has been shown to be teratogenic in mice. High altitude hypoxia has also been shown to induce congenital vertebral anomalies in mice. The purpose of this study was to investigate the effect of maternal hypoxia owing to CO exposure and the production of congenital spinal deformities in the offspring. Sixty DBA-1J mice were bred using polygamous timed breeding methods. Pregnant females were exposed to 200, 400, or 600 ppm CO using a custom-designed gas blender system. Seven-hour exposures were performed on day 8.5, 9.5, or 10.5 of the 21-day gestation cycle. The neonates were euthanized at birth; the specimens were fixed, eviscerated, and radiographed. Congenital spinal deformities were observed (wedge, hemi, fused, and missing vertebrae; fused ribs) and were located in all regions of the spine. There was a statistically significant difference in the number of spinal deformities between all groups, with no defects in the controls and a 77% incidence at 600 ppm (p < 0.0001). There was no apparent correlation between the time of exposure and defect location. The most sensitive time of gestation was 9.5 days. We identified an animal model of congenital spinal deformities that compares favorably with the evidence of human congenital spinal deformities in cases of maternal exposure to CO and other gas and chemical fumes.

Ligand-independent dimerization activates the stress response kinases IRE1 and PERK in the lumen of the endoplasmic reticulum

IRE1 and PERK are type I transmembrane serine/threonine protein kinases that are activated by unfolded proteins in the endoplasmic reticulum (ER) to signal adaptive responses. IRE1 is present in all eukaryotic cells and signals the unfolded protein response through its kinase and endoribonuclease activities. PERK signals phosphorylation of a translation initiation factor to inhibit protein synthesis in higher eukaryotic cells but is absent in the Saccharomyces cerevisiae genome. The amino acid sequences of the amino-terminal ER luminal domains (NLDs) from IRE1 and PERK display limited homology and have diverged among species. In this study, we have demonstrated that the NLD of yeast Ire1p is required for signaling. However, the NLDs from human IRE1alpha and murine IRE1beta and the Caenorhabditis elegans IRE1 and PERK function as replacements for the S. cerevisiae Ire1p-NLD to signal the unfolded protein response. Replacement of the Ire1p-NLD with a functional leucine zipper dimerization motif yielded a constitutively active kinase that surprisingly was further activated by ER stress. These results demonstrate that ER stress-induced dimerization of the NLD is sufficient for IRE1 and PERK activation and is conserved through evolution. We propose that ligand-independent activation of IRE1 and PERK permits homodimerization upon accumulation of unfolded proteins in the lumen of the ER.

[Molecular clonging of the human dimethyglycine dehydrogenase-like gene (DMGDHL1) from the sarcosinemia critical region at 9q34]

Through the analysis of EST database, we obtained one human EST (GenBank: H28856) which showed significant similarity with the partial coding sequence of rat dimethylglycine dehydrogenase gene. This EST was mapped to 9q34 due to 95.6% identity with one genomic sequence (GenBank: AC002295). A pair of primers (HRP-1/HRP-2) designed on the sequence of the EST were coupled with the primers (lambda gt10-5/lambda gt10-3) on the vector flanking cloning site respectively to amplify the 5' and 3' cDNA beyond the EST. New primers designed based on novel cDNA sequence overlapped with the sequence within EST H28856 were used for amplification with lambda gt10-5 and lambda gt10-3 by the similar way as above untill a complete ORF was obtained. Finally, a 1,970 bp sequence (termed as dimethylglycine dehydrogenase like gene isoform I, DMGDHL1a) containing a 1,428 bp complete coding sequence from the live cDNA library and 1,475 bp sequence (isoform II, termed as DMGDHL1b) containing a 1,296 bp complete coding sequence from the fetas live cDNA library were obtained. Fourteen exons were identified in isoform I and the first nine exons of isoform II which shared with isoform I could be determined too. The last 105 bp cDNA sequence of isoform II could not be found in the public database, indicating a very large intron (> 123 kb) existed between exon 9 and exon 10 of isoform II. DMGDHL1 showed highly homology on both cDNA and amino acid level with rat dimethylglycine dehydrogenase (60% identity in 135 bp and 35% identity in 436 residues respectively). It was reported that human sarcosinemia gene was mapped at 9q34. Therefore it could be a good candidate gene for the sarcosinemia.

Erythromycin inhibits beta2-integrins (CD11b/CD18) expression, interleukin-8 release and intracellular oxidative metabolism in neutrophils

Macrolides have therapeutic benefits on chronic inflammatory airway diseases. Thus, macrolides are supposed to have variable biological effects apart from antimicrobial activity. Neutrophil adherence and influx with oxidants and cytokines production implicates involvement in airway inflammation. To investigate whether erythromycin (EM) affects neutrophil activity in vitro, lipopolysaccharide (LPS)-treated neutrophils were continuously incubated for 4 h in the absence or presence of increasing doses of EM from 1 microg ml(-1) to 100 microg ml(-1) in the last 2 h. Leukocyte adhesion molecules Mac-1 and intracellular H2O2(DCFH) were determined by flowcytometric assay. IL-8 and TNFalpha in supernatant was measured by ELISA method. The expression of Mac-1 and mean intracellular DCF fluorescence intensity (DCFH) of neutrophils significantly increased after stimulation with LPS. Pretreatment with EM significantly decreased LPS induced Mac-1 expression on neutrophils compared with LPS stimulation only. EM alone (100 microg ml(-1)) also decreased Mac-1 expression on neutrophils. EM significantly reduced the LPS-increased DCFH. EM alone (100 microg ml(-1)) also caused a decrease in DCFH. Increasing doses of EM also significantly decreased the IL-8 released by LPS-stimulated neutrophils. In conclusion, EM exerts a direct effect on the neutrophils by downregulating the expression of beta2-integrin on neutrophils, thus leading to a decrease in the intracellular H2O2, as well as the production of IL-8. Our conclusion provides an explanation for the clinical efficacy of erythromycin in neutrophil-mediated airway inflammation.

Safety of MRI-guided endovascular guidewire applications

Magnetic radiofrequency (RF) fields applied during magnetic resonance imaging (MRI) may induce heating in devices made from conductive materials. The present paper reports on theoretical and experimental studies on the RF heating resonance phenomenon of an endovascular guidewire. A nitinol-based guidewire was inserted into a vessel phantom and imaged at 1.5 and 0.2 T with continuous temperature monitoring at the guidewire tip. The heating effects due to different experimental settings were examined. A model is developed for the resonant current and the associated electric field produced by the guidewire acting as an antenna. Temperature increases of up to 17 degrees C were measured while imaging the guidewire at an off-center position in the 1.5 T MR system. Power absorption produced by the resonating wire decreased as the repetition time was increased. No temperature rise was measured at 0.2 T. Considering the potential utility of low-field, open MR systems for MRI-guided endovascular interventions, it is important to be aware of the safety of such applications.