Clinical outcome of stent implantation in small coronary arteries using different types of coronary stents

PURPOSE

We evaluated the results of stent placement in small coronary arteries.

SUBJECTS

The subjects were divided into 2 groups: the first contained 911 lesions treated with stenting in the coronary arteries (stent group), and the second contained 1,203 background- and patient-matched lesions treated with balloon angioplasty (POBA group). There was no significant difference in the background of patients or lesions between the groups. A "small coronary artery" was defined as a coronary artery with a reference vessel diameter < 3.0 mm.

RESULTS

There was no significant difference in incidence of acute myocardial infarction (AMI), coronary artery bypass grafting, or death between the groups. In the stent group, acute occlusion (0.8%) and subacute thrombosis (2.1%) occurred. The restenosis rate of 29.8% in the stent group was significantly lower than in the POBA group (38.2%; p < 0.01). The restenosis rate of 19.4% in stented vessels 3.0 mm diameter was significantly lower than in vessels < 3.0 mm diameter (29.8%; p < 0.01). The rate of restenosis was 22.9% for the Multi-Link stent, 24.4% for the NIR stent, 34.1% for the GFX stent, and 35.3% for the PS stent. The restenosis rate of 23.8% in stented vessels > 2.5 mm diameter and < or = 20 mm length was significantly lower than in vessels , < or = 2.5 mm diameter and > 20 mm length (32.7%; p < 0.01). Factors associated with restenosis, analyzed using a stepwise multivariate logistic regression model, included ostial lesions and post-procedural minimum lumen diameter.

CONCLUSIONS

Stent implantation in vessels < 3.0 mm diameter using a newly designed coronary stent yielded favorable clinical results, while there was a high prevalence of restenosis, leading to diffused stenotic lesions, in vessels < 2.5 mm diameter.

Correlates of antibiotic use in Taiwan hospitals

OBJECTIVE

To determine factors that correlate with increased antibiotic use among adult inpatients in Taiwan.

DESIGN

Retrospective survey of medical records.

SETTING

14 acute-care hospitals (8 regional hospitals, 6 medical centers) in Taiwan.

PARTICIPANTS

A systematic probability sample from each hospital, totaling 663 adult inpatients who were discharged or had died in early 1999.

MEASUREMENTS

Infectious disease physicians at the 14 hospitals collected data from medical records regarding patient demographics, hospitalization, discharge diagnosis, and antibiotics received.

RESULTS

A total of 447 (67%) patients received antibiotics for an overall rate of 813 antibiotic-days (number of days patients received each antibiotic)/1,000 patient-days. Both the proportion of beds in intensive care units ([ICUs] Pearson correlation coefficient [r], 0.67; 95% confidence interval [CI 95], 0.36-0.89; P<.01) and the proportion of patients admitted to surgical services (r, 0.66; CI 95, 0.20-0.88; P=.01) correlated with the mean patient rate of antibiotic-days/hospital-day (MPAUD). In contrast, we found no correlation between the proportion of patients who received antibiotics and the MPAUD. Using multiple linear regression, medical center status was the only independent predictor for increased MPAUD (regression coefficient [b], 0.15; CI 95, 0.05-0.24; P<.01). There was no correlation between pooled rates of antibiotic-days/hospital-day and any hospital demographic factors. First-generation cephalosporin (39%) and aminoglycoside (24%) use accounted for the majority of antibiotic-days.

CONCLUSIONS

Antibiotic use is greater in medical centers than in regional hospitals and appears to be independent of surgical case mix or the proportion of ICU beds. Determination of multiple, independent measures of antibiotic use may be necessary to understand the relation between antibiotic use and resistance in hospital.

Diversity of SHV and TEM beta-lactamases in Klebsiella pneumoniae: gene evolution in Northern Taiwan and two novel beta-lactamases, SHV-25 and SHV-26

A total of 113 blood culture isolates of Klebsiella pneumoniae from 10 hospitals in northern Taiwan were studied for SHV and TEM beta-lactamase production. bla(SHV) was amplified from all isolates by PCR. TEM-type resistance, was found in 32 of the isolates and was of the TEM-1 type in all isolates. SHV-1, -2, -5, -11, and -12 and two novel enzymes were identified. These novel enzymes were designated SHV-25 and SHV-26 and had pIs of 7.5 and 7.6, respectively. Amino acid differences in comparison to the amino acid sequence of bla(SHV-1) were found at positions T18A (ThrACC-->AlaGCC), L35Q (LeuCTA-->GluCAA), and M129V (MetATG-->ValGTG) for SHV-25 and at position A187T (AlaGCC-->ThrACC) for SHV-26. The results of substrate profiles and MIC determinations showed that the novel enzymes did not hydrolyze extended-spectrum cephalosporins, rendering the isolates susceptible to these agents. Inhibition profiles revealed that the 50% inhibitory concentration for SHV-26 was higher than those for SHV-1 and SHV-25, resulting in an intermediate resistance to amoxicillin-clavulanic acid. Forty-nine ribotypes were identified, suggesting that major clonal spread had not occurred in any of the hospitals. According to the amino acid sequence, SHV beta-lactamases in Taiwan may basically be derived through stepwise mutation from SHV-1 or SHV-11 and further subdivided by four routes. The stepwise mutations initiated from SHV-1 or SHV-11 to SHV-2, SHV-5, and SHV-12 comprise the evolutionary change responsible for extended-spectrum beta-lactamase (ESBL) production in Taiwan. The stepwise mutations that lead to a non-ESBL (SHV-25) and the beta-lactamase (SHV-26) with reduced susceptibility to clavulanic acid are possibly derived from SHV-11 and SHV-1, respectively. The results suggest a stepwise evolution of SHV beta-lactamases in Taiwan.

Factors accounting for misidentification of Candida species

From April 15 through June 15, 1999, a total of 660 yeast isolates were collected from 22 hospitals in Taiwan to investigate factors determining the accuracy of yeast identification. The germ tube test was the method most frequently used by hospitals for yeast identification, followed by the API-32C, cornmeal agar window test, and assimilation method. All of the submitted isolates were re-speciated in the National Health Research Institutes laboratory. The frequencies of inconsistent identification of isolates between hospitals and the National Health Research Institutes laboratory varied with the location and the type of hospital. The sensitivity and specificity of the germ tube test were 95% and 98.6%, respectively. This study showed that hospitals using the germ tube test as the first step in yeast identification had fewer inconsistent identifications of isolates than those using other methods. The VITEK Yeast Biochemical Card and API-32C had a sensitivity of 92.6% and 98.3%, respectively. No single method consistently identified all yeast isolates. Thus, every laboratory should have at least 2 methods available for yeast identification.

Molecular epidemiology and mutations at gyrA and parC genes of ciprofloxacin-resistant Escherichia coli isolates from a Taiwan medical center

Sixty-five ciprofloxacin-resistant clinical Escherichia coli isolates were collected from a Taiwan Medical Center from December 1998 to February 1999. All 65 clinical isolates were resistant (MICs > or = 4 microg/mL) to the following fluoroquinolones: ofloxacin, levofloxacin, sparfloxacin, and trovafloxacin. These isolates were cross-resistant to chloramphenicol (65 isolates, 100%), tetracycline (65 isolates, 100%), cefuroxime (64 isolates, 98.5%), ampicillin (57 isolates, 87.7%), gentamicin (53 isolates, 81.5%), and cephalothin (24 isolates, 36.9%). Pulsed-field gel electrophoresis (PFGE) revealed a high diversity among the genomes of these isolates and indicated that clonal spread was not responsible for the prevalence of ciprofloxacin resistance in the hospital. Sequencing of the polymerase chain reaction (PCR) amplified products of the quinolone resistance determining regions (QRDRs) of gyrA and parC showed that all isolates carrying double mutations in gyrA at codon 83 and 87 and at least one parC mutation at codon 80 and/or 84. The mutation at codon 83 of GyrA from serine to leucine (S83L) was present in all the clinical isolates. The most prevalent pattern was the S83L mutation and the mutation at codon 87 from an aspartate to an asparagine (D87N) of GyrA plus a mutation from a serine to an isoleucine (S80I) at codon 80 of ParC (63.2%). This indicated that the presence of high-level resistance to quinolones in clinical E. coli isolates were associated with mutations at hot spots, codon 83 and 87 in GyrA and followed by subsequent mutation in either codon 80 and/or 84 in ParC.

In vivo transtracheal adenovirus-mediated transfer of human interleukin-10 gene to donor lungs ameliorates ischemia-reperfusion injury and improves early posttransplant graft function in the rat

We examined the effect of adenovirus-mediated transtracheal transfer of the human interleukin 10 (hIL-10) gene on lung ischemia-reperfusion (IR) injury, which is the insult due to hypothermic preservation plus graft reperfusion, and posttransplant lung function in Lewis rat lungs. Thirty rats were divided into 6 groups (n = 5). Groups 1 and 4 received 5 x 10(9) PFU of Ad5E1RSVhIL-10, groups 2 and 5 received 5 x 10(9) PFU of Ad5BGL2 ("empty" vector), and groups 3 and 6 received 3% sucrose (diluent). After 24 hr of in vivo transfection, lungs were stored at 4 degrees C (cold ischemic time, CIT) for 6 hr (groups 1-3) or 24 hr (groups 4-6) before transplantation. After 2 hr of reperfusion, lung function was assessed by oxygenation (FIO2, 1.0), airway pressure (AwP), and wet-to-dry (W/D) weight ratios. Rat tumor necrosis factor alpha (rTNF-alpha), interferon gamma (IFN-gamma), IL-10, and hIL-10 were measured in graft tissue and recipient plasma by ELISA and detected by immunohistochemistry (IHC). Partial pressure of oxygen (PaO2) levels in the hIL-10 group (6 hr of CIT) were higher than in empty vector and diluent groups (PaO2, 530 +/- 23 vs. 387 +/- 31 and 439 +/- 27 mmHg, respectively, p < 0.05). IL-10 rats after 24 hr of CIT showed higher PaO2 levels (260 +/- 29 mmHg) than empty vector (96 +/- 24 mmHg) or diluent (133 +/- 10 mmHg) lungs (p < 0.05). AwP and W/D ratios were reduced in hIL10 lungs (p < 0.05) compared with the other groups. rTNF-alpha and INF-gamma were reduced in tissue and plasma in groups 1 and 4 (p < 0.05). rIL-10 was reduced in the tissue of hIL-10 lungs (p < 0.05). IHC showed equal distribution of cytokines in tissue and abundant transgene expression in large and small airway epithelium in hIL-10 lungs.

Past infection with hepatitis A virus among Vancouver street youth, injection drug users and men who have sex with men: implications for vaccination programs

BACKGROUND

In Canada, inactivated hepatitis A vaccines are targeted selectively at those at increased risk for infection or its complications. In order to evaluate the need for routine hepatitis A vaccination programs in Vancouver for street youth, injection drug users (IDUs) and men who have sex with men (MSM), we determined the prevalence of antibodies against hepatitis A virus (HAV) and risk factors for HAV in these groups.

METHODS

The frequency of past HAV infection was measured in a sample of Vancouver street youth, IDUs and MSM attending outreach and STD clinics and needle exchange facilities by testing their saliva for anti-HAV immunoglobulin G. A self-administered, structured questionnaire was used to gather sociodemographic data. Stepwise logistic regression was used to evaluate the association between presumed risk factors and groups and past HAV infection.

RESULTS

Of 494 study participants, 235 self-reported injection drug use, 51 were self-identified as MSM and 111 met street youth criteria. Positive test results for anti-HAV were found in 6.3% of street youth (95% confidence interval [CI] 2.6%-12.6%), 42.6% (95% CI 36.2%-48.9%) of IDUs and 14.7% (95% CI 10.4%-19.1%) of individuals who denied injection drug use. Among men who denied injection drug use, the prevalence was 26.3% (10/38) for MSM and 12% (21/175) for heterosexuals. Logistic regression showed that past HAV infection was associated with increased age and birth in a country with high rates of hepatitis infection. Injection drug use among young adults (25-34 years old) was a significant risk factor for a positive anti-HAV test (p = 0.009). MSM were also at higher risk for past HAV infection, although this association was nominally significant (p = 0.07).

INTERPRETATION

Low rates of past HAV infection among Vancouver street youth indicate a low rate of virus circulation in this population, which is vulnerable to hepatitis A outbreaks. An increased risk for HAV infection in IDUs and MSM supports the need to develop routine vaccination programs for these groups also.

Outer membrane protein change combined with co-existing TEM-1 and SHV-1 beta-lactamases lead to false identification of ESBL-producing Klebsiella pneumoniae

Nine isolates of Klebsiella pneumoniae, obtained from one colonized and eight bacteraemic patients on a paediatric ward, were shown to be identical by PFGE, indicating an outbreak. Screening for extended-spectrum beta-lactamase (ESBL) production using the double-disc synergy test, Etest for ESBLs and agar diffusion tests indicated ESBL production. The isolates showed reduced susceptibility to cefotaxime but not to other third-generation cephalosporins. Molecular studies revealed production of TEM-1 and SHV-1 but no ESBLs were identified. Deficiency in expression of an outer membrane protein (OmpK35) was also observed. These observations led us to postulate that the extremely low level of OmpK35 expression and the co-existence of TEM-1 and SHV-1 resulted in an increased MIC of cefotaxime and the false designation of the isolates as ESBL producers. All the infected infants were treated with either third-generation cephalosporins alone or multiple antibiotics including a third-generation cephalosporin, and recovered and were discharged without sequelae.

The use of antibiotics critical to human medicine in food-producing animals in Taiwan

There are increasing public health concerns about antibiotics used in food-producing animals that may contribute to the development of resistance in human pathogens. Such resistance may be critical to human medicine when resistance develops to drugs that treat certain pathogens of which there is no good alternative therapy. We surveyed 10 farms, eight feed mills, and one animal drug distributor in Taiwan to determine the major antibiotics used in food-producing animals, and the extent of use of five drugs that may select for resistance to antibiotics that are critical for human medicine. The five animal drugs, and the resistance of human drug/class they may select for, included avoparcin (vancomycin/glycopeptides), avilomycin (ziracin/envirninomycins), enrofloxacin (ciprofloxacin/fluoroquinolones), virginiamycin (quinupristin and dalfopristin combination/streptogramins), and kanamycin (gentamicin/aminoglycosides). Tetracyclines were the class of antibiotic that was most widely used in the greatest amounts. Over the past 12 months, the number of farms, chicken feed mills, and pig feed mills, that have respectively reported the use of avoparcin was 1 (10%), 5 (63%), 0; avilomycin 0, 0, 3 (50%); enrofloxacin 4 (40%), 1 (13%), 3 (50%); virginiamycin 2 (20%), 5 (63%), 0; and kanamycin 3 (30%), 1 (13%), 1 (17%). We conclude that although the most commonly used antibiotics (ie tetracyclines) have little effect on human medicine, there is a widespread use of antibiotics that may select for critical forms of resistance in human pathogens in food-producing animals.

Efficacy of cutting balloon angioplasty for in-stent restenosis: an intravascular ultrasound evaluation

BACKGROUND

The increase in the use of stents has seen the increasing emergence of in-stent restenosis (ISR). Reports suggest that the Cutting Balloon (Interventional Technologies, San Diego, California) may be a useful treatment modality for this new clinical entity.

METHODS

In this study, we compared the efficacy of Cutting Balloon angioplasty (CBA) with conventional balloon angioplasty (PTCA) for ISR in 47 patients (47 lesions). Results were evaluated with intravascular ultrasound (IVUS). The CBA group included 25 patients (mean age, 65 +/- 78 years; 7 females) and the PTCA group included 22 patients (mean age, 69 +/- 51 years; 6 females).

RESULTS

The procedural success rate was 100% in both groups. IVUS showed that luminal area acute gain was larger in the CBA group (2.5 +/- 0.8 mm2) compared to the PTCA group (1.8 +/- 1.0 mm2), while late loss was smaller in the CBA group (0.5 +/- 0.4 mm2) compared to the PTCA group (1.3 +/- 0.5 mm2). The change in total area was similar in both groups. The increase in area at the stented portion was 0.4 +/- 0.8 mm2 in the CBA group and 1.2 +/- 0.5 mm2 in the PTCA group. The restenosis rate at follow-up (mean follow-up, 5.4 months) was higher in PTCA patients (59%) than in the CBA patients (24%).

CONCLUSION

CBA may result in no increase in total vessel area, a constant stent area, a decrease in plaque area, and an increase in lumen area (induced by the decrease in plaque area). Our IVUS findings suggest that compared to PTCA, the dilatation mechanism of CBA may be associated with reduced dilatation of both the total vessel area and the stent area for ISR. The mechanism of this modality may minimize injury to the intimal membrane and may potentially be a primary device for in-stent restenosis in the future.

Polymicrobial outbreak of intermittent peritoneal dialysis peritonitis during external wall renovation at a dialysis center

OBJECTIVE

To investigate an outbreak of peritonitis in intermittent peritoneal dialysis (IPD) patients.

DESIGN

An outbreak investigation was performed to identify the etiology of the polymicrobial outbreak, and a retrospective case-control study was conducted to assess the risk factors for development of peritonitis.

SETTING

Renal dialysis center.

PATIENTS

Ten episodes of peritonitis occurred in 8 of 61 patients over a 6-month period in which 669 IPD procedures were analyzed.

INTERVENTIONS

Field visit to renal dialysis center to examine the entire IPD procedure, inspect the hospital environment, and perform air bacterial count.

MAIN OUTCOME MEASURES

The environmental factors and risk factors contributing to the polymicrobial peritonitis outbreak in IPD patients. The incidence of IPD peritonitis was determined before and after interventions.

RESULTS

The causative organisms included Acinetobacter baumanii (6), Stenotrophomonas maltophilia (2), Pseudomonas aeruginosa (1), Candida albicans (1), C. tropicalis (1), Enterococcus (3), and Enterobacteriaceae (2). Four episodes of peritonitis involved infection by more than one organism. Air sampling of the environment detected a median of 110 colony forming units of bacteria per cubic meter of air, 10% of which were found to be Acinetobacter baumanii. The source of this polymicrobial outbreak was attributed to the bamboo scaffolding structure covering the external wall of the hospital during renovation. A retrospective case-control study indicated that the absence of the flush-before-fill step was a risk factor for development of peritonitis.

CONCLUSION

In addition to invasive aspergillosis in transplant or oncology patients, Acinetobacter peritonitis in dialysis patients should be considered another microbial cause of outbreak associated with hospital renovation.

Chest wall tenderness is unhelpful in the diagnosis of recurrent chest pain

We investigated whether the presence of chest wall tenderness or fibromyalgia helped to distinguish between ischaemic and non-ischaemic chest pain. Seventy-one patients with recurrent chest pain, 36 with normal (group A) and 35 with abnormal coronary angiograms (group B), were assessed by investigator-administered questionnaires, and were examined for chest wall tenderness and fibromyalgia by a single blinded observer. Chest wall tenderness was greater in group A. However, it was much greater in women, who predominated in group A, than in men, who predominated in group B, and this explained the intergroup difference. Seven patients (25%) (six female, one male) in the group A and one patient (3%) (male) in group B (chi(2) p=0.027) fulfilled criteria for fibromyalgia. Patients with recurrent chest pain are more likely to have a ischaemic cause if they are male. Although our study suggests that chest wall tenderness alone in patients with recurrent chest pain has no value in excluding myocardial ischaemia as a cause, the confounding factor of gender prevents our study design from answering this question conclusively. Fibromyalgia is commoner in patients with chest pain and normal coronary angiograms, but may be related to the excess of females in this group. Its presence does not preclude the co-existence of ischaemic heart disease.

Factors associated with the development of post-transplant lymphoproliferative disease (PTLD) in Epstein-Barr virus (EBV)-seronegative adult liver transplant recipients

Epstein-Barr virus (EBV) infection is recognized as the principal aetiological factor in the pathogenesis of post-transplant lymphoproliferative disease (PTLD), particularly when primary EBV infection occurs after transplantation. We analysed, using a time-dependent proportional hazards model, the factors associated with development of PTLD in 40 adult liver transplant recipients who were seronegative for EBV prior to transplantation. Of 40 patients, 13 (33%) had a tissue diagnosis of PTLD at a median time of 126 days after transplantation. The multivariate analysis showed that prior CMV disease, the number of steroid boluses given and the number of units of RBC and FFP transfused were significant risk factors for development of PTLD.

Effect of timing of introduction of complementary foods on iron and zinc status of formula fed infants at 12, 24, and 36 months of age

OBJECTIVE

The timing of introduction of complementary food to an infant's diet is variable throughout the world. Our objective was to determine whether early introduction of complementary foods affects iron and zinc status of formulated infants at 12, 24, and 36 months of age.

DESIGN

A randomized, prospective trial was conducted. Infants were randomly assigned to receive either a) early introduction (at 3 to 4 months of age) of commercially prepared or parent's choice of complementary foods; or b) late introduction (at 6 months of age) of commercially prepared complementary foods or parent's choice of complementary foods. In addition to complementary foods, infants were fed commercial infant formula as recommended by their pediatrician. Hemoglobin, mean corpuscular volume, and serum ferritin and zinc concentrations were determined at 12, 24, and 36 months of age. Three-day diet diaries were completed at 3, 6, 12, 18, 24, 30, and 36 months of age.

SUBJECTS/SETTING

One hundred seventy-five infants younger than 3 months were recruited by mailings to parents in the Cincinnati area. Of these, 172 were enrolled, 90 in the early-introduction group and 82 in the late-introduction group. One hundred thirty-three infants (n = 67 in the early, n = 66 in the late group) completed the study.

STATISTICAL ANALYSES PERFORMED

Student t test and regression analyses were used to determine whether there were group differences and whether there was a relationship between serum parameters and dietary intake.

RESULTS

Infants fed complementary foods early had significantly greater iron intakes until 6 months of age; however, there were no differences in the iron status parameters (ferritin, hemoglobin, and mean corpuscular volume) at 12, 24, or 36 months of age. The early introduction group consumed slightly less zinc than the late introduction group at 5 months (4.4 vs 4.8 mg/day, P < .01) and 6 months (4.4 vs 4.7 mg/day, P < .01). At all other times there were no differences between the early and late group in zinc intakes. The serum zinc concentration was not associated with dietary zinc. Both groups had normal serum zinc concentrations at 12, 24, and 36 months and there were no differences between groups.

APPLICATIONS/CONCLUSIONS

The iron and zinc status of infants in this study was not influenced by the timing or type of complementary foods introduced. However, the infants were formula fed and the mean iron and zinc intakes that were equal or greater than the Recommended Dietary Allowances for the first 6 months of age.

Intravascular ultrasound findings in patients with abnormal coronary flow reserve after stenting

A coronary flow reserve (CFR) of 2.0 has been advocated as the endpoint for coronary intervention therapy. Experience shows, however, that CFR does indeed exceed 2.0 in many cases poststenting, while remaining below 2.0 in others. In this study, we assessed the clinical characteristics and IVUS findings of patients whose CFR remained below 2.0 after stent implantation, specifically 16 patients with CFR below 2.0 (22 lesions, 64 +/- 9 years, 4 female), and 102 patients with CFR above 2.0 (112 lesions, mean age 66 +/- 11 years, 22 female). Patient population comprised patients selected for retrospective study, but participants were selected on the basis of matching patient and lesion characteristics. The IVUS findings showed that incidence of calcified lesions and post-PTCA dissection of hard plaque were higher among patients with CFR < 2.0. Further, IVUS-obtained vascular measurements showed post-PTCA area stenosis to be 58.7 +/- 15.2% in the CFR < 2.0 group, and 45.3 +/- 12.5% among CFR > or = 2.0 patients (P < 0.05). These findings indicate that patients with diffuse calcified lesions or high post-PTCA % area stenosis, as determined by IVUS, are more likely to have lower CFR after stenting.

Physiological functions of protein kinase inhibitors

Protein kinases are key regulatory enzymes involved in a multitude of biochemical pathways. This chapter will describe the current research on targeting specific protein kinases with inhibitors in attempts to disrupt flux through specific pathways. Targeting specific kinases presents a distinct challenge as there are hundreds of individual kinase enzymes that use ATP as a substrate to phosphorylate specific target molecules. The challenge clearly lies in obtaining specificity for a given kinase, thus allowing inhibition or activation of a specific pathway. This chapter will focus on two areas of kinase inhibitors, those that target the MAP kinase pathway and those directed against the phosphatidylinositol-3 kinase (PI-3K) related kinase family. The cellular and physiological effects of inhibition of the various pathways controlled by these kinases will be reviewed.

Individual and combined effects of ethanol and cocaine on the human dopamine transporter in neuronal cell lines

Concurrent use of cocaine and alcohol results in reinforced behavioral consequences, but the molecular mechanisms associated with the co-use of both drugs are not clear. We report here that a 24-h exposure of the human dopamine transporter (hDAT)-transfected mouse neuroblastoma N1E-115 cell line (6C6) to cocaine (1 microM), or ethanol (1%) or both, increased dopamine re-uptake by approximately 25, 29 and 44%, respectively. The same treatment also increased dopamine re-uptake by the hDAT-transfected mouse neuroblastoma Neuro2A cell line (3B7) by approximately 36, 41 and 77%, respectively. However, no increase of dopamine re-uptake was observed in the hDAT-transfected non-neuronal CHO cell line (10E9). These data support the hypothesis that the DAT may be a common neural substrate for cocaine and ethanol in dopaminergic neurons and it may be involved in the psychological effects of both addictions.

Use and abuse of surgical antibiotic prophylaxis in hospitals in Taiwan

BACKGROUND AND PURPOSE

A large proportion of antibiotics used in hospitals is for surgical prophylaxis. We determined the prevailing practices and factors associated with the misuse of surgical antibiotic prophylaxis in hospitals in Taiwan.

METHODS

In a systematic survey of the medical records of 629 patients from 14 hospitals who underwent clean or clean-contaminated surgery from September 1998 through March 1999, data on the timing and duration of, and reasons for, antibiotic use were collected and analyzed.

RESULTS

Overall, 578 (92%) patients received antibiotics perioperatively; in 499 (79%) cases, antibiotics were used for surgical prophylaxis. Only 302 (61%) patients received prophylaxis within 1 hour before surgery. More than 70% of patients received more than 3 days of postoperative antibiotic prophylaxis. The most commonly used antibiotics were first-generation cephalosporins and aminoglycosides. Factors independently associated with inappropriately timed prophylaxis included surgery performed at a hospital with a greater proportion of intensive care unit beds (conditional odds ratio [OR] = 1.14 per 1% increase, 95% confidence interval [CI95%] 1.06-1.23; p < 0.01), surgery duration of at least 1 hour (OR = 0.40, CI95% 0.24-0.67; p < 0.01), orthopedic surgery (OR = 0.59, CI95% 0.36-0.98; p = 0.041), and cardiothoracic surgery (OR = 2.07, CI95% 1.14-3.77; p = 0.02). Risk factors for more than 3 days of prophylaxis included surgical placement of prosthetic material (OR = 2.26, CI95% 1.10-4.64; p = 0.03), the number of antibiotics used (OR = 1.99 per antibiotic, CI95% 1.26-3.13; p < 0.01), surgery duration of at least 1 hour (OR = 3.07, CI95% 1.45-6.51; p < 0.01), neurosurgery (OR = 4.57, CI95% 2.24-9.31; p < 0.01), and the use of oral antibiotics together with intravenous drugs (OR = 20.72, CI95% 10.72-40.07; p < 0.01).

CONCLUSIONS

The results of this survey indicate that inappropriate use of surgical antibiotic prophylaxis is common in hospitals in Taiwan. Our results identify several problem areas, including incorrect timing, duration, and use of oral antibiotics for surgical prophylaxis, that require targeted physician education and public health interventions.

V89L polymorphism of type-2, 5-alpha reductase enzyme gene predicts prostate cancer presence and progression

OBJECTIVES

The valine (V) to leucine (L) polymorphism of the SRD5A2 gene is associated with 5-alpha reductase-2 activity; patients with the V allele have high activity and patients with the L allele have low activity. We examined whether this polymorphism predicts the presence of prostate cancer in 320 men without cancer who underwent biopsy and cancer progression in 318 men who underwent radical prostatectomy.

METHODS

The effect of the SRD5A2 gene in predicting the presence of prostate cancer was examined using logistic regression analysis, controlling for established risk factors. The effect of the SRD5A2 gene in predicting prostate cancer progression was examined using a nested, matched, case-control design. Most of the participants were white.

RESULTS

Of the 320 men, 158 (49.4%) were found on biopsy to have prostate cancer. The overall distribution of the V/V, V/L, and L/L genotypes was 47.5%, 42.5%, and 10.0%, respectively. The adjusted odds ratio for having prostate cancer for patients with at least one V allele was 2.53 compared with patients with the L/L genotype (P = 0.03). Of the 318 patients with cancer, 80 had biochemically detected recurrence and 238 had no evidence of recurrence. The odds ratio for progression for patients with at least one V allele was 3.32 (95% confidence interval 1.67 to 6.62, P = 0.0006) compared with patients with the L/L genotype.

CONCLUSIONS

Men who have the V allele of the SRD5A2 gene have a twofold increase in the risk of prostate cancer development and an additional twofold increase in the risk of progression compared with men with the L/L genotype.

Enterovirus 71: the virus, its infections and outbreaks

Enterovirus 71 (EV71) was first recognized in 1974. Since then it has been implicated in 13 small and large outbreaks world-wide. Large outbreaks of hand, foot and mouth disease (HFMD), mostly benign, occurred in Japan in 1973 and 1978. Four outbreaks with brain stem encephalitis and significant numbers of deaths occurred in Bulgaria and Hungary in the late 1970's and in Malaysia and Taiwan in 1997 and 1998 respectively. During the latter two epidemics, pulmonary edema and hemorrhage often leading to quick deaths in children aged from 0.5 to 3 years old was first recognized. In Taiwan 78 deaths and over 100,000 cases of HFMD occurred. Coxsackie A16 cocirculated with EV 71, without however, causing any severe illnesses. The transmission of EV 71 was related to number of siblings in a household, rural residence and contact with cases of HFMD. Genotype analyses show that genotypes have changed with time in the United States and Japan. Recent isolates from Japan are similar to the isolates from Malaysia and Taiwan in 1997 and 1998, respectively. Even though genotype analysis has not identified specific sequences responsible for neurovirulence, the strains causing brain stem encephalitis and pulmonary edema in the Far East are similar and have arisen since 1997. Seroepidemiological studies in Taiwan suggest that children aged from 0.5 to 4 years old are most susceptible while the rest of the population are over 50% immune. Theoretically there is a pool of such susceptible subjects every few years. In prevention for another major outbreak, a simple, inactivated Salk type vaccine should be immediately prepared and made available.

The mouse Kell blood group gene (Kel): cDNA sequence, genomic organization, expression, and enzymatic function

The human Kell blood group system is important in transfusion medicine, since Kell is a polymorphic protein and some of its antigens can cause severe reactions if mismatched blood is transfused, while maternal alloimmunization may lead to fetal and neonatal anemia. In humans, Kell is an Mr 93,000 type II membrane glycoprotein with endothelin-3-converting enzyme activity that is linked by a single disulfide bond to another protein, XK, that spans the membrane ten times. An absence of XK leads to clinical symptoms termed the McLeod syndrome. We determined the cDNA sequence of the mouse Kell homologue, the organization of the gene, expression of the protein and its enzymatic function on red cells. Comparison of human and mouse Kell cDNA showed 80% nucleotide and 74% amino acid sequence identity. Notable differences are that the mouse Kell protein has eight probable N-linked carbohydrate side chains, compared to five for human Kell, and that the mouse homologue has one more extracellular cysteine than human Kell protein. The mouse Kell gene (Kel), like its human counterpart, is similarly organized into 19 exons. Kel was located to proximal Chromosome 6. Northern blot analysis showed high expression in spleen and weaker levels in testis and heart. Western blot analysis of red cell membrane proteins demonstrated that mouse Kell glycoprotein has an apparent Mr of 110,000 and, on removal of N-linked sugars, 80,000. As in human red cells, Kell is disulfide-linked to XK and mouse red cells have endothelin-3-converting enzyme activity.

Visualization of Plasmodium falciparum-endothelium interactions in human microvasculature: mimicry of leukocyte recruitment

Plasmodium falciparum-infected erythrocytes roll on and/or adhere to CD36, intercellular adhesion molecule (ICAM)-1, vascular cell adhesion molecule (VCAM)-1, and P-selectin under shear conditions in vitro. However, the lack of an adequate animal model has made it difficult to determine whether infected erythrocytes do indeed interact in vivo in microvessels. Therefore, we made use of an established model of human skin grafted onto severe combined immunodeficient (SCID) mice to directly visualize the human microvasculature by epifluorescence intravital microscopy. In all grafts examined, infected erythrocytes were observed to roll and/or adhere in not just postcapillary venules but also in arterioles. In contrast, occlusion of capillaries by infected erythrocytes was noted only in approximately half of the experiments. Administration of an anti-CD36 antibody resulted in a rapid reduction of rolling and adhesion. More importantly, already adherent cells quickly detached. The residual rolling after anti-CD36 treatment was largely inhibited by an anti-ICAM-1 antibody. Anti-ICAM-1 alone reduced the ability of infected erythrocytes to sustain rolling and subsequent adhesion. These findings provide conclusive evidence that infected erythrocytes interact within the human microvasculature in vivo by a multistep adhesive cascade that mimics the process of leukocyte recruitment.

Synergism of multiple adhesion molecules in mediating cytoadherence of Plasmodium falciparum-infected erythrocytes to microvascular endothelial cells under flow

Plasmodium falciparum-infected erythrocytes (IRBCs) have been shown to interact with a number of endothelial adhesion molecules expressed on transfectants, on cell lines, and as immobilized purified receptor proteins under flow conditions. However, the experiments were designed in such a way that maximal numbers of adhesion molecules were provided as substratum. Whether the interactive events actually occur on microvascular endothelium, where the distribution and expression of adhesion molecules may be less, remains undetermined. In this study, the cytoadherance of IRBCs on human dermal microvascular endothelial cells (HDMECs) as a model of human microvasculature was examined. IRBCs were observed to tether, roll, and adhere on resting HDMECs, which constitutively expressed CD36 and intercellular adhesion molecule-1 (ICAM-1) at an optimal shear stress of 1 dyne/cm(2). Stimulation of HDMECs with tumor necrosis factor-alpha for 5 and 24 hours, which resulted in up-regulation of ICAM-1 and induction of vascular cell adhesion molecule-1 expression, significantly increased the percentage of rolling cells that adhered without affecting the rolling flux. In contrast, P-selectin expression on HDMECs induced by oncostatin M led to an increase in both rolling flux and adhesion. Inhibition studies with receptor-specific monoclonal antibodies revealed that adhesion of IRBCs on HDMECs was largely CD36 dependent, whereas rolling could be mediated by any of the adhesion molecules studied. Collectively, these findings indicate that IRBCs interact synergistically with multiple adhesion molecules on vascular endothelium. The rolling of IRBCs may be the rate-limiting step in cytoadherance, since it can be modulated by cytokines to enhance CD36-mediated IRBC adhesion.

Efficacy of directional coronary atherectomy before stent implantation for coronary ostial lesions

We evaluated stent implantation following directional coronary atherectomy (DCA) for coronary ostial lesions. The subjects were 27 patients (27 lesions) who underwent stent deployment after DCA, and 47 patients (47 lesions) who underwent stent deployment alone as the control group. There were no differences in numbers of lesions with multi-vessel disease, left anterior descending artery lesions, de novo lesions or reference vessel diameters in the two groups. The percent diameter stenosis after stent implantation was lower in the DCA-stent group than in the stent-alone group (9 +/- 10% versus 17 +/- 14%, respectively; p < 0.01). The initial procedural success rate was 92.6% in the DCA-stent group and 91.4% in the stent-alone group. The initial clinical success rate was 100% in the DCA-stent group and 95.7% in the stent-alone group. The restenosis rate was lower in the DCA-stent group (20% versus 43% in the stent-alone group). This study showed that debulking by DCA before stenting is more effective compared to stenting alone.

Characterization of the ORL(1) receptor on adrenergic nerves in the rat anococcygeus muscle

1. Nociceptin, the endogenous ORL(1) receptor agonist inhibited the motor response to electrical-field stimulation in the rat anococcygeus muscle. This effect was characterized using the peptide ligands acetyl-Arg-Tyr-Tyr-Arg-Trp-Lys-NH(2) (Ac-RYYRWK-NH(2)), acetyl-Arg-Tyr-Tyr-Arg-Ile-Lys-NH(2) (Ac-RYYRIK-NH(2)) and [Phe(1)psi(CH(2)-NH)Gly(2)]nociceptin(1-13)NH(2) ([F/G]NC(1-13)NH(2)), and the non-selective opioid antagonist naloxone benzoylhydrazone (NalBzOH). 2. Nociceptin produced a concentration-dependent inhibition of the adrenergic motor response to electrical-field stimulation (EC(50) 19 nM, pEC(50) 7.7+/-0.1, n=8), but the response to exogenous noradrenaline (0.2 - 1 microM) was unaffected. The inhibitory nerve response was not affected by up to 1 microM nociceptin. 3. After inhibition of nitric oxide synthase (N(omega)-nitro-L-arginine 100 microM), and in the presence of peptidase inhibitors, nociceptin produced full inhibition of the pure adrenergic motor response (EC(50) 4 nM; pEC(50) 8.4+/-0.1, E(max) 98.3+/-1.2%, n=12). Ac-RYYRWK-NH(2) was a potent partial-agonist (pEC(50) 9.0+/-0.1, E(max) 66.4+/-5.2; n=11) but the efficacy of Ac-RYYRIK-NH(2) (pEC(50) 8.0+/-0.2, E(max) 36.7+/-3.5; n=12) was lower and the peptide could be tested as an antagonist (pA(2) 9.01). 4. [F/G]NC(1-13)NH(2) and NalBzOH had little or no efficacy and were competitive antagonists with pK(B) values of 7.4 (95% c.l. 7.1, 7.7) and 6.9 (95% c.l. 6.7, 7.1) respectively. Both increased the response to field stimulation at high concentrations, suggesting the release of an endogenous agonist for the ORL(1) receptor during stimulation. 5. Rat nocistatin did not affect the response to electrical-field stimulation, nor did it modify the inhibitory action of nociceptin. 6. Our findings suggest there is a significant endowment of ORL(1) receptors on sympathetic terminals of the rat anococcygeus, where nociceptin mediates a powerful inhibitory effect on adrenergic neuromuscular transmission.

Differential modulation and subsequent blockade of mitogenic signaling and cell cycle progression by Pasteurella multocida toxin

The intracellularly acting protein toxin of Pasteurella multocida (PMT) causes numerous effects in cells, including activation of inositol 1,4,5-trisphosphate (IP(3)) signaling, Ca(2+) mobilization, protein phosphorylation, morphological changes, and DNA synthesis. The direct intracellular target of PMT responsible for activation of the IP(3) pathway is the G(q/11)alpha-protein, which stimulates phospholipase C (PLC) beta1. The relationship between PMT-mediated activation of the G(q/11)-PLC-IP(3) pathway and its ability to promote mitogenesis and cellular proliferation is not clear. PMT stimulation of p42/p44 mitogen-activated protein kinase occurs upstream via G(q/11)-dependent transactivation of the epidermal growth factor receptor. We have further characterized the effects of PMT on the downstream mitogenic response and cell cycle progression in Swiss 3T3 and Vero cells. PMT treatment caused dramatic morphological changes in both cell lines. In Vero cells, limited multinucleation, nuclear fragmentation, and disruption of cytokinesis were also observed; however, a strong mitogenic response occurred only with Swiss 3T3 cells. Significantly, this mitogenic response was not sustained. Cell cycle analysis revealed that after the initial mitogenic response to PMT, both cell types subsequently arrested primarily in G(1) and became unresponsive to further PMT treatment. In Swiss 3T3 cells, PMT induced up-regulation of c-Myc; cyclins D1, D2, D3, and E; p21; PCNA; and the Rb proteins, p107 and p130. In Vero cells, PMT failed to up-regulate PCNA and cyclins D3 and E. We also found that the initial PMT-mediated up-regulation of several of these signaling proteins was not sustained, supporting the subsequent cell cycle arrest. The consequences of PMT entry thus depend on the differential regulation of signaling pathways within different cell types.

Significance of the CAG repeat polymorphism of the androgen receptor gene in prostate cancer progression

PURPOSE

The CAG repeat polymorphism of the androgen receptor gene has been associated with an increased prostate cancer risk, and the repeat length correlated with cancer stage and grade at presentation. Men with an allele length of </= 18 CAG repeats have a 2-fold increase in risk for high-stage or high-grade prostate cancer, compared with patients with a longer CAG repeat. We examined the significance of the CAG repeat polymorphism of the androgen receptor gene for predicting prostate cancer progression among 318 patients treated by radical prostatectomy for clinically localized prostate cancer between 1987 and 1994.

MATERIALS AND METHODS

Leukocyte DNA was collected and genotyping of the CAG repeat polymorphism was performed using a PCR-based direct sequencing method. Risk ratios were calculated for developing biochemical recurrence for patients associated with an allele length of </= 18 CAG repeats, compared with patients with an allele length of >18 CAG repeats, controlling for grade, stage and serum PSA level at diagnosis using Cox proportional hazard modeling.

RESULTS

Overall, the CAG repeat allele was not predictive of recurrence; tumor grade, stage and PSA level at diagnosis were the only predictors of recurrence in a multivariate analysis. However, for patients at low risk for recurrence (Gleason score 2 to 6, stage pT2, and PSA </= 10 ng./ml.), the relative risk of recurrence associated with an allele of </= 18 CAG repeats was 8.07 (95% C.I., 2.02 to 32.2, p = 0.004), compared with patients with an allele length of >18 CAG repeats. In contrast, for patients at high risk of recurrence (Gleason score >/= 7, stage pT3/4, or PSA >10 ng./ml.), the relative risk associated with the </= 18 CAG repeat allele was 0.72 (95% C.I., 0.33 to 1.57, p = 0.41), compared with patients with the >18 CAG repeat allele.

CONCLUSIONS

The length of the CAG repeat polymorphism of the androgen receptor gene may be important for prostate cancer recurrence among patients who are otherwise at low risk for recurrence after radical prostatectomy. These findings have potential implications for patient selection for adjuvant treatment, and for the development of novel treatments.

Dopamine uptake by mouse neuroblastoma N1E-115 cells stably expressing human dopamine transporter is differentially inhibited by anti-idiotypic ab2beta antibodies mimicking the configuration of cocaine

We have successfully constructed a mouse neuronal N1E-115 cell line stably expressing a fully functional human dopamine transporter (hDAT). Previous studies in our laboratory have produced several anti-idiotypic Ab2beta antibodies that mimic the configuration of the cocaine molecule at their antigen-combining site. In the present study, we observed that some anti-idiotypic Ab2beta antibodies inhibited dopamine uptake by the hDAT-transfected line. Each antibody showed a different level of inhibition (between 40% and 90%). These findings suggest that the internal images of these antibodies can be used as analog peptides that may compete with cocaine for its binding site on the transporter but not impair dopamine uptake as much as cocaine does.

5-HT(1A) receptor agonist-antagonist binding affinity difference as a measure of intrinsic activity in recombinant and native tissue systems

1. It has been reported that radiolabelled agonist : antagonist binding affinity ratios can predict functional efficacy at several different receptors. This study investigates whether this prediction is true for recombinant and native tissue 5-HT(1A) receptors. 2. Saturation studies using [(3)H]-8-OH-DPAT and [(3)H]-MPPF revealed a single, high affinity site (K(D)approximately 1 nM) in HEK293 cells expressing human 5-HT(1A) receptors and rat cortex. In recombinant cells, [(3)H]-MPPF labelled 3 - 4 fold more sites than [(3)H]-8-OH-DPAT suggesting the presence of more than one affinity state of the receptor. [(3)H]-Spiperone labelled a single, lower affinity site in HEK293 cells expressing h5-HT(1A) receptors but did not bind to native tissue 5-HT(1A) receptors. These data suggest that, in transfected HEK293 cells, human 5-HT(1A) receptors exist in different affinity states but in native rat cortical tissue the majority of receptors appear to exist in the high agonist affinity state. 3. Receptor agonists inhibited [(3)H]-MPPF binding from recombinant 5-HT(1A) receptors in a biphasic manner, whereas antagonists and partial agonists gave monophasic inhibition curves. All compounds displaced [(3)H]-8-OH-DPAT and [(3)H]-spiperone binding in a monophasic manner. In rat cortex, all compounds displaced [(3)H]-MPPF and [(3)H]-8-OH-DPAT in a monophasic manner. 4. Functional evaluation of compounds, using [(35)S]-GTPgammaS binding, produced a range of intrinsic activities from full agonism, displayed by 5-HT and 5-CT to inverse agonism displayed by spiperone. 5. [(3)H]-8-OH-DPAT : [(3)H]-MPPF pK(i) difference correlated well with functional intrinsic activity (r=0.86) as did [(3)H]-8-OH-DPAT : [(3)H]-spiperone pK(i) difference with functional intrinsic activity (r=0.96). 6. Thus agonist : antagonist binding affinity differences may be used to predict functional efficacy at human 5-HT(1A) receptors expressed in HEK293 cells where both high and low agonist affinity states are present but not at native rat cortical 5-HT(1A) receptors in which only the high agonist affinity state was detectable.

Effect of adult microsurgical varicocelectomy on testicular volume

OBJECTIVES

To re-examine the potential influence of varicocelectomy on testicular volume using scrotal ultrasonography, because it has been reported that total testicular volume (assessed by physical examination) increases after adult varicocele ligation.

METHODS

A retrospective review of the testicular volume and semen parameters of 61 men who underwent microsurgical varicocelectomy between 1996 and 1998 was performed. Ultrasound-derived testicular volumes and total motile sperm counts were compared before varicocelectomy and at a mean of 7.2 months postoperatively.

RESULTS

Bilateral varicocelectomy was performed in 22 men; 39 men underwent a left-sided procedure only. Overall, no significant change was found in the mean total testicular volume after varicocelectomy compared with preoperatively (24.0 versus 23.9 mL, respectively; P = 0.74). Similarly, the testicular volumes did not change significantly after left or bilateral varicocelectomy (P >0.05). Overall, the mean total motile sperm count increased significantly after varicocelectomy (17. 9 to 25.4, P = 0.05).

CONCLUSIONS

This was the first study to examine the effect of adult varicocelectomy on testicular volume using ultrasound-derived measurements of volume. Unlike previous findings, our data suggest that although adult varicocelectomy improves semen quality in most infertile men, it does not result in a significant increase in testicular volume.

A 5-year study of the seroepidemiology of Klebsiella pneumoniae: high prevalence of capsular serotype K1 in Taiwan and implication for vaccine efficacy

Seroepidemiology of Klebsiella pneumoniae was determined for 1000 nonrepetitive K. pneumoniae isolates collected by a medical center in Taiwan during 1993-1997. Of these, 630 isolates (63%) were from community-acquired infections; the rest were from hospital-acquired infections. The isolates were serotyped according to capsular antigen by countercurrent immunoelectrophoresis. About 77% were typeable. Serotypes K1 and K2 accounted for 21.7% and 9.3% of the isolates, respectively, followed by K57 (5.1%), K54 (4.2%), K21 (3. 3%), and K16 (3%). The frequency of serotype K1 among bacteremic isolates (30.8%) far exceeded that reported by other investigators worldwide. Molecular typing of random K1 isolates by pulsed-field gel electrophoresis revealed several different pulsotypes, suggesting a nonclonal spread. This study indicates that a Klebsiella vaccine developed in Europe is not optimal for use in Taiwan because it does not contain the most predominant serotypes-K1, K54, and K57.

An observer-blinded comparison of supervised and unsupervised aerobic exercise regimens in fibromyalgia

OBJECTIVE

To compare a supervised 12-week aerobic exercise class with unsupervised home aerobic exercises in the treatment of patients with fibromyalgia.

METHODS

This was a 48-week randomized single (observer) blind study in a teaching hospital rheumatology and physiotherapy department. The subjects were 74 patients who fulfilled the American College of Rheumatology criteria for fibromyalgia. Results and conclusions. A 12-week exercise class programme with home exercises demonstrated no benefit over a single physiotherapy session with home exercises in the treatment of pain in patients with fibromyalgia. Neither group (nor the groups combined) showed an improvement in pain compared with baseline. There was some significant benefit in psychological well-being in the exercise class group and perhaps a slowing of functional deterioration in this group.

[(3)H]-SB-269970--A selective antagonist radioligand for 5-HT(7) receptors

Binding of the 5-HT(7) receptor antagonist radioligand [(3)H]-SB-269970 to human 5-HT(7(a)) receptors expressed in HEK293 cell membranes (h5-HT(7(a))/293) and to guinea-pig cerebral cortex membranes, was characterized and compared with [(3)H]-5-CT binding. [(3)H]-SB-269970 (1 nM) showed full association with h5-HT(7(a))/293 membranes after 40 min. Specific binding at equilibrium represented >90% of total binding and was fully reversible by methiothepin (10 microM), full dissociation occurring by 100 min. The association (k(+1)) and dissociation (k(-1)) rate constants were 0.05 nM(-1)min(-1) and 0.05 min(-1) respectively, giving a K(D) (k(-1)/k(+1)) of 1.0 nM. [(3)H]-SB-269970 bound saturably and apparently monophasically to both h5-HT(7(a))/293 and guinea-pig cortex membranes, with K(D) values of 1.25+/-0.05 and 1.7+/-0.3 nM respectively. The B(max) for [(3)H]-SB-269970 to both h5-HT(7(a))/293 and guinea-pig cortex membranes (5780+/-380 and 125+/-8.2 fmoles mg protein(-1) respectively) was similar to that for [(3)H]-5-CT (6190+/-940 and 143+/-19 fmoles mg protein(-1) respectively). These data suggest that, in each tissue, both radioligands labelled the same population of receptors, which appear to be present in an agonist high affinity state. The profile of compound inhibition of [(3)H]-SB-269970 binding to h5-HT(7(a))/293 and guineapig cortex membranes correlated well (corr. coeff. 0.98) with those for [(3)H]-5-CT binding and were consistent with the profiles reported previously for the human 5-HT(7(a)) and guinea-pig cortex 5-HT(7) receptors using [(3)H]-5-CT. Hill slopes for inhibition of [(3)H]-SB-269970 and [(3)H]-5-CT binding were close to 1, consistent with binding to a single receptor population in both tissues. [(3)H]-SB-269970 represents the first selective 5-HT(7) antagonist radioligand, which should aid further characterization of 5-HT(7) receptors in recombinant and native tissues and help establish their role in brain function.

Comparison of screening methods for detection of extended-spectrum beta-lactamases and their prevalence among Escherichia coli and Klebsiella species in Hong Kong

Three tests, the disk diffusion test, the double-disc synergy test and the inhibitor-potentiated disc diffusion test, were compared for their abilities to detect production of extended-spectrum beta-lactamases (ESBL) in 702 Escherichia coli and 472 Klebsiella spp. strains from four hospitals. Eleven percent E. coli and 13% Klebsiella spp. were found to produce ESBL. As an indicator of ESBL activity, the sensitivities of the five extended-spectrum beta-lactams were as follows: cefotaxime (100%), cefpodoxime (99.3%), ceftriaxone (98.6%), aztreonam (93%) and ceftazidime (57.7%) when interpreted using the National Committee for Clinical Laboratory Standards criteria. Their positive predictive values ranged from 67.8-83.8%. Both the inhibitor-potentiated disc diffusion test and the double-disc synergy test (at three inter-disc widths of 20, 25 and 30 mm) were capable of identifying all the ESBL-producers. However, at a single inter-disc width of 30 mm, the double-disc synergy test has limited sensitivity (83.8%). As a second test for confirming ESBL activity in strains with reduced susceptibility to beta-lactams, the inhibitor-potentiated disc diffusion test is therefore a simple and reliable option.

Bacteremia due to extended-spectrum beta-lactamase-producing Escherichia coli and Klebsiella pneumoniae in a pediatric oncology ward: clinical features and identification of different plasmids carrying both SHV-5 and TEM-1 genes

Thirteen patients who had 16 episodes of bacteremia were observed between 1993 and 1997 in a pediatric oncology ward with a high background isolation rate of cefotaxime- or aztreonam-resistant gram-negative bacteria. Four blood isolates were Escherichia coli and 12 were Klebsiella pneumoniae, and these isolates harbored extended-spectrum beta-lactamases (ESBLs). All episodes of bacteremia were nosocomial, all except one of the episodes occurred in neutropenic patients, and all patients were treated with piperacillin or ceftazidime with amikacin and cefazolin prior to the onset of bacteremia. Nine of 13 patients were receiving extended-spectrum beta-lactam treatment when the bacteremias caused by ESBL producers occurred. Molecular studies revealed that four K. pneumoniae SHV-2-producing isolates from 1994 were of the same clone. Other ESBL producers, including six that carried both TEM-1 and SHV-5, five that carried SHV-5, and one that carried SHV-2 alone, were unrelated. In conclusion, SHV-5 was present in 11 of the 16 isolates and coexisted with TEM-1 in 6 isolates. Acquisition of resistance genes probably occurred under antibiotic selection pressure. This study highlights the importance of routine checks for and detection of ESBL producers. Effective therapy against ESBL producers should be considered early for children who have malignancies and neutropenia and who are septic, despite treatment with a regimen that includes an extended-spectrum beta-lactam, in a clinical setting of an increased incidence of ESBL-producing bacteria.

Risk factors for acquired myasthenia gravis in cats: 105 cases (1986-1998)

OBJECTIVE

To determine prevalence of initial clinical signs and risk factors for acquired myasthenia gravis (MG) in cats.

DESIGN

Retrospective case-control study.

ANIMALS

105 cats from the United States, Canada; and the United Kingdom with a confirmed diagnosis of acquired MG and 510 cats with other neuromuscular disorders, including generalized weakness, megaesophagus, and dysphagia (control group).

PROCEDURES

Records were retrieved from a data-base containing results of serum samples tested for acetylcholine receptor antibodies. Signalment, including breed, age, and state or country of origin, month of onset, and initial clinical signs were obtained. An acetylcholine receptor antibody titer > 0.3 nmol/L was diagnostic for acquired MG. Unconditional logistic regression was used for statistical analysis.

RESULTS

Compared with mixed-breed cats, the breed with the highest relative risk of acquired MG was the Abyssinian (including Somali). Significant differences between sexes were not detected. There was no compelling evidence for a difference in risk of developing MG between states or countries. Relative risk increased after 3 years of age. The most common clinical signs were generalized weakness without megaesophagus and weakness associated with a cranial mediastinal mass. Focal signs, including megaesophagus and dysphagia without signs of generalized weakness, were also evident.

CONCLUSIONS AND CLINICAL RELEVANCE

A breed predisposition for acquired MG in Abyssinians (and related Somalis) was observed. Clinical signs were variable and included generalized weakness, megaesophagus, and dysphagia. A cranial mediastinal mass was commonly associated with MG in cats.

Predictors of adverse events with intramuscular ketamine sedation in children

STUDY OBJECTIVE

Ketamine is a safe and effective sedative for emergency department procedures in children. However, the use of ketamine sometimes is associated with airway complications, emesis, and recovery agitation. We wished to identify predictors of these adverse events that clinicians might use to risk-stratify children who are candidates for ketamine sedation.

METHODS

We analyzed data from 1,021 ED intramuscular ketamine sedations in children 15 years of age or younger at a university medical center and an affiliated county hospital over a 9-year period. Five potential predictor variables (age, gender, American Society of Anesthesiologists' [ASA] risk classification, quantity of first ketamine dose, and number of ketamine doses administered) were compared between children with and without complications. We used multiple logistic regression analyses to determine the association of these 5 variables with emesis and recovery agitation, and validated these analyses with bootstrap resampling techniques. We compared children with and without airway complications using univariate statistics alone, as there were too few patients with airway complications to support a multivariate analysis.

RESULTS

No study variables had significant univariate associations with airway complications (all P values >.40). We found emesis to be associated with increasing age in multivariate analysis (odds ratio [OR] 1.25 per year, bias-corrected 95% confidence interval [CI] 1.17 to 1.34, P<.001). The incidence of emesis was 12. 1% in children aged 5 years or older, and 3.5% in those younger than 5 years (Delta8.6%, 95% CI 4.9% to 12.1%). Recovery agitation was associated with the presence of an underlying medical condition (ie, ASA class > or =2, OR 3.05, bias-corrected 95% CI 1.65 to 7.30, P=.004) and inversely associated with increasing age (OR 0.79 per year, bias-corrected 95% CI 0.69 to 0.89, P<.001). The incidence of recovery agitation was 17.9% in ASA class 1 children and 33.3% in children in ASA class 2 or greater (Delta-15.4%, 95% CI 0.0% to -30. 7%). The incidence of recovery agitation was 12.1% in children aged 5 years or older, and 22.5% in those younger than 5 years (Delta-10. 4%, 95% CI -3.0% to -17.7%). Bootstrap resampling techniques validated the importance of the significant variables identified in the regression analyses.

CONCLUSION

No study variable was predictive of ketamine-associated airway complications. Emesis that occurred after ketamine administration was modestly associated with increasing age. Recovery agitation was modestly associated with decreasing age and the presence of an underlying medical condition. The discriminatory power of these variables was low enough as to be unlikely to alter clinical decisions regarding patient selection for ketamine administration. No evidence of a significant ketamine dose relationship was noted for airway complications, emesis, or recovery agitation.

Macrovascular disease and systemic sclerosis

OBJECTIVE

To determine if macrovascular disease is more prevalent in systemic sclerosis (SSc) compared with unaffected subjects.

METHODS

54 patients with SSc (both limited and diffuse disease) and 43 unaffected control subjects of similar age and sex were recruited. All subjects underwent a basic screen for conventional atherosclerotic disease risk factors. All had non-invasive vascular assessments-that is, carotid duplex scanning and measurement of ankle brachial blood pressure index-to identify the presence of asymptomatic peripheral vascular disease.

RESULTS

33 of 52 (64%) patients had carotid artery disease compared with only 15 of 42 (35%) controls (p=0.007). Eleven (21%) of these patients had moderate disease compared with only two (5%) controls (NS). Nine of 53 (17%) SSc patients had evidence of peripheral arterial disease compared with no controls. This result was also statistically significant (p=0.003). There were no significant differences in the basic risk factor profile, which included cigarette smoking, systolic and diastolic blood pressure, cholesterol, trigyceride and glucose concentrations.

CONCLUSION

Macrovascular disease is more common in SSc. Screening of these patients may allow identification of "at risk" patients at an early stage and allow the study of treatments to attenuate the high rate of cardiovascular mortality in these patients.

Surveillance of antibiotic resistance in Taiwan, 1998

For the first national surveillance of antibiotic resistance in Taiwan, we collected in 1998 from 22 hospitals (6 medical centers, 15 regional hospitals, and 1 local hospital) 3,211 isolates in all parts of the country. Besides 50 random successive isolates from inpatients, each hospital was requested to collect 25 isolates each from positive blood cultures, hospital-acquired infections, outpatients and the pediatric department. We re-speciated all the submitted specimens and determined their antibiotic susceptibility patterns. The most common isolates were Enterobacteriaceae (Escherichia coli, Klebsiella pneumoniae), Staphylococcus aureus, and Pseudomonas aeruginosa. Among hospital-acquired infections, Acinetobacter spp. were among those which accounted for over 10% of the isolates. The oxacillin resistance of S. aureus was 82% in isolates from hospital-acquired infections, and 40% from outpatients. Among Enterococcus spp., 85% were either E. faecalis or E. faecium. They were 14% resistant to vancomycin. Among gram-negative bacteria, K. pneumoniae and Acinetobacter baumanii were hospital-acquired isolates that were most clearly more resistant than community acquired isolates. This difference was less apparent in the case of Enterobacter cloacae, Serratia marcescens, and P. aeruginosa. These bacteria were generally more resistant from all sources. Fifty-one percent of Salmonella were resistant to ampicillin; however, these were all sensitive to ciprofloxacin. Isolates from the East were least resistant. Plotting the disc zone diameters of antibiotics within the susceptible range, we identified subpopulations with smaller diameters in the case of vancomycin against S. aureus, ciprofloxacin against E. coli, and ciprofloxacin against Salmonella spp. These findings represent one of the purposes of this surveillance as they may portend developing resistances which bear careful watching in the future.

The prognostic and pathophysiologic role of pro- and antiinflammatory cytokines in severe malaria

Pro- and antiinflammatory cytokines were measured on admission in 287 consecutive Vietnamese adults with severe falciparum malaria. Plasma interleukin (IL)-6, IL-10, and tumor necrosis factor (TNF)-alpha concentrations and the IL-6: IL-10 ratio were significantly higher in patients who died than in survivors (P<.001). On multivariate analysis, hyperparasitemia, jaundice, and shock were all associated independently with raised IL-6, IL-10, and interferon-gamma, and acute renal failure specifically with raised TNF-alpha levels. Cerebral malaria patients, particularly those without other vital organ dysfunction, had significantly lower levels of these cytokines (P=.006), reflecting a more localized pathology. Serial IL-6 and IL-10 measurements made on 43 patients who died and matched survivors indicated a relative deficiency in IL-10 production as death approached. Elevated plasma cytokines in severe malaria are associated with systemic pathologic abnormalities, not cerebral involvement. Both the overall magnitude of the cytokine responses and the eventual imbalance between the pro- and antiinflammatory responses are important determinants of mortality.

An epidemic of enterovirus 71 infection in Taiwan. Taiwan Enterovirus Epidemic Working Group

BACKGROUND

Enteroviruses can cause outbreaks of hand-foot-and-mouth disease (characterized by vesicular lesions on the hands, feet, and oral mucosa) or herpangina, usually without life-threatening manifestations. In 1998 an epidemic of enterovirus 71 infection caused hand-foot-and-mouth disease and herpangina in thousands of people in Taiwan, some of whom died.

METHODS

We assessed the epidemiologic aspects of this outbreak. Cases of hand-foot-and-mouth disease or herpangina in ambulatory patients were reported to the Taiwan Department of Health by a mean of 818 sentinel physicians. Severe cases in hospitalized patients were reported by 40 medical centers and regional hospitals. Viruses were isolated by 10 hospital laboratories and the department of health.

RESULTS

The sentinel physicians reported 129,106 cases of hand-foot-and-mouth disease or herpangina in two waves of the epidemic, which probably represents less than 10 percent of the estimated total number of cases. There were 405 patients with severe disease, most of whom were five years old or younger; severe disease was seen in all regions of the island. Complications included encephalitis, aseptic meningitis, pulmonary edema or hemorrhage, acute flaccid paralysis, and myocarditis. Seventy-eight patients died, 71 of whom (91 percent) were five years of age or younger. Of the patients who died, 65 (83 percent) had pulmonary edema or pulmonary hemorrhage. Among patients from whom a virus was isolated, enterovirus 71 was present in 48.7 percent of outpatients with uncomplicated hand-foot-and-mouth disease or herpangina, 75 percent of hospitalized patients who survived, and 92 percent of patients who died.

CONCLUSIONS

Although several enteroviruses were circulating in Taiwan during the 1998 epidemic, enterovirus 71 infection was associated with most of the serious clinical manifestations and with nearly all the deaths. Most of those who died were young, and the majority died of pulmonary edema and pulmonary hemorrhage.

Effects of antenatal corticosteroids on blood pressure in very low birth weight infants during the first 24 hours of life

OBJECTIVE

We tested the hypothesis that prenatal glucocorticoids significantly increase mean arterial blood pressure in very low birth weight preterm infants during the first 24 hours after birth.

STUDY DESIGN

Prospectively collected data from 178 inborn infants with birth weights between 500 and 1499 gm were examined. A total of 80 infants were born to mothers treated with corticosteroids (birth weight: 1057 +/- 271 gm, gestational age: 28.0 +/- 2.6 weeks), and 98 infants were untreated controls (birth weight: 1030 +/- 280 gm, gestational age: 28.0 +/- 2.8 weeks). The study setting was a university-based tertiary care center for newborn intensive care.

RESULTS

Mean blood pressures on admission and at 3, 6, 12, 18, and 24 hours were significantly higher in steroid-treated infants. Steroid-treated infants received significantly less volume expansion (3.8 +/- 8.5 ml/kg versus 14.4 +/- 20.7 ml/kg; p < 0.001) than controls. Vasopressor support was also reduced in the steroid group (2.5% versus 11.5%; p < 0.05).

CONCLUSION

Antenatal steroids are associated with both a higher mean systemic blood pressure and a decreased use of vasopressors and plasma expanders in very low birth weight infants during the first 24 hours after birth. This effect is not limited to infants of < 1000 gm; it is also significant in infants with a birth weight between 1000 and 1499 gm, and is already detectable in the first hours of life. We speculate that this finding may contribute to the mechanism of steroid protection against conditions such as intraventricular hemorrhage.

The beneficial effects of omega-3 and omega-6 essential fatty acid supplementation on red blood cell rheology

Twenty healthy, non-smoking subjects were enrolled into a study to investigate the effects of dietary supplementation with essential fatty acid (EFAs) on red blood cell rheology. Ten subjects were given 3 months dietary supplementation with long chain polyunsaturated EFAs containing omega-3 and omega-6 EFAs while 10 others were given placebo (sunflower oil). Venous sampling was performed at 0 and 12 weeks and red blood cell (RBC) aggregation and deformability measured by a filtration system. The results showed a reduction in RBC aggregation in the group given omega-3 and omega-6 EFAs but not in the placebo group. This may be related to changes in the RBC membrane and surface receptor characteristics. Such EFAs may be useful in Raynaud's phenomenon.

Molecular mechanisms of cytoadherence in malaria

Microbial pathogens subvert host adhesion molecules to disseminate or to enter host cells to promote their own survival. One such subversion is the cytoadherence of Plasmodium falciparum-infected erythrocytes (IRBC) to vascular endothelium, which protects the parasite from being removed by the spleen. The process results in microcirculatory obstruction and subsequent hypoxia, metabolic disturbances, and multiorgan failure, which are detrimental to the host. Understanding the molecular events involved in these adhesive interactions is therefore critical both in terms of pathogenesis and implications for therapeutic intervention. Under physiological flow conditions, cytoadherence occurs in a stepwise fashion through parasite ligands expressed on the surface of IRBC and the endothelial receptors CD36, intercellular adhesion molecule-1 (ICAM-1), P-selectin, and vascular adhesion molecule-1. Moreover, rolling on ICAM-1 and P-selectin increases subsequent adhesion to CD36, indicating that receptors can act synergistically. Cytoadherence may activate intracellular signaling pathways in both endothelial cells and IRBC, leading to gene expression of mediators such as cytokines, which could modify the outcome of the infection.

Longitudinal study of calcium intake, physical activity, and bone mineral content in infants 6-18 months of age

Although increased physical activity early in life is recommended for optimizing bone health, no controlled trials on the effect of activity on bone mass accretion during periods of rapid growth have been reported. The purpose of this study was to determine whether infants randomized to a 1 year gross motor activity program had a greater bone mass accretion than infants randomized to a fine motor activity program. The gross motor program included activities that focused on loading the skeleton and were performed for 15-20 minutes/day, 5 days/week by study personnel. Infants (n = 72) were enrolled at 6 months of age, and total body bone mineral content (BMC), 3-day diet records, and activity levels were obtained at 6, 9, 12, 15, and 18 months. BMC was associated with weight, length, and bone area at all ages and correlated with earlier calcium intakes. Calcium intake appeared to modify the effect of gross motor activity on bone mass accretion; infants in both groups had similar bone accretion at moderately high calcium intakes, but at low calcium intakes infants in the gross motor program had less bone accretion than infants in the fine motor program. Compliant infants in the gross motor group had lower BMC at 18 months compared with noncompliant infants. These results indicate that BMC in infants is related to calcium intake, and we speculate that participation in a gross motor program during rapid bone growth may lead to reduced bone accretion in the presence of a moderate to moderately low calcium intake.

Functional comparison of muscarinic partial agonists at muscarinic receptor subtypes hM1, hM2, hM3, hM4 and hM5 using microphysiometry

1. This study describes the pharmacological comparison of the muscarinic partial agonists sabcomeline, xanomeline and milameline at human cloned muscarinic receptor subtypes (hM1-5). 2. Radioligand binding studies at the hM1-5 muscarinic receptor subtypes were compared with functional studies using microphysiometry using carbachol as the standard full agonist. 3. In binding assays none of the compounds studied displayed preferential affinity for the M1,3,4 or M5 subtypes although carbachol was less potent at hM1 than hM3,4,5. 4. In functional studies, all of the compounds studied displayed similar levels of efficacy across the muscarinic receptors with the exception of M3, where there was a large apparent receptor reserve and the compounds behaved essentially as full agonists. 5. Sabcomeline was the most potent agonist in functional studies but also showed the lowest efficacy. In terms of potency, xanomeline showed some selectivity for M1 over M2 receptors and milameline showed some selectivity for M2 over M1 receptors. 6. These results show the value of microphysiometry in being able to compare receptor pharmacology across subtypes irrespective of the signal transduction pathway. 7. None of the partial agonists showed functional selectivity for M1 receptors, or indeed any muscarinic receptor, in the present study.