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N Keller

Publications and source records attributed to N Keller.

At least 19 recordsLinked to original sources
PubMed2006

An outbreak of Mycobacterium jacuzzii infection following insertion of breast implants.

BACKGROUND: Surgical wound infections caused by rapidly growing mycobacteria developed in 15 women after insertion of breast implants from August to November 2003 at a single medical center. METHODS: A case-control study was conducted that included the identified patients, as well as women who underwent breast operations at the same center who did not develop infections. The study was accompanied by an extensive environmental investigation. Isolates were identified by standard bacteriological methods and by comparison of their 16S rRNA, HSP65, RPOB, SODA, and RECA gene sequences. Isolates were compared by random amplified polymorphic DNA analysis and by pulsed-field gel electrophoresis. RESULTS: The risk factors for infection included surgery performed by 1 specific surgeon (odds ratio, 21.3; 95% confidence interval, 3.64-125.6). Identical strains of mycobacteria were isolated from the infected wounds of the patients; from the eyebrows, hair, face, nose, ears, and groin of this particular surgeon; and from this surgeon's outdoor whirlpool. The isolates exhibited a biochemical profile overlapping that of Mycobacterium wolinskyi, but their sequences of 16S rRNA and HSP65, RPOB, SODA, and RECA genes differed. We propose the name "Mycobacterium jacuzzii" for this new species. DNA fingerprints of cultured isolates from the surgical wounds, areas of the surgeon's body that grow hair, and the surgeon's whirlpool were identical. When the surgeon discontinued his use of the whirlpool and began cleaning the hairy areas of his body with a shampoo containing triclosan, the outbreak ended. CONCLUSIONS: This outbreak brings to light the possibility of the colonization of human skin and human-to-human transmission of environmental mycobacteria during surgery that involves implant insertion.

Adolescent↗
PubMed2006

Stable gastric pentadecapeptide BPC 157 in trials for inflammatory bowel disease (PL-10, PLD-116, PL 14736, Pliva, Croatia). Full and distended stomach, and vascular response.

Gastric pentadecapeptide BPC 157 (GEPPPGKPADDAGLV, M.W. 1419, safe in clinical trials for inflammatory bowel disease (PL 10, PLD 116, PLD 14736, Pliva, Croatia)) has a particular cytoprotective/adaptive cytoprotective activity. The cytoprotective/adaptive cytoprotection researches largely neglect that stomach distension could per se jeopardize the mucosal integrity, with constantly stretched mucosa and blood vessels, and sphincters more prone for reflux induction. After absolute alcohol instillation in fully distended rat stomach, gastric, esophageal and duodenal lesions occur. Throughout next 3 min, left gastric artery blood vessels clearly disappear at the serosal site, indicative for loss of vessels both integrity and function. Contrary, constant vessels presentation could predict the beneficial effect of applied agent. After pentadecapeptide BPC 157 instillation into the stomach the vessels presentation remains constant, and lesions of stomach, esophagus, and duodenum are inhibited. Standards (atropine, ranitidine, omeprazole) could only slightly improve the vessels presentation compared to control values, and they have only a partial effect on the lesions. In this review we emphasize BPC 157 unusual stability, and some of its important effects: effectiveness against various lesions in gastrointestinal tract, on nitric oxide (NO)-system, and NO-agents effects, on somatosensory neurons, salivary glands function, recovery of AMP-ADP-ATP system, endothelium protection, effect on endothelin, and on angiogenesis promotion. It also antagonizes other alcohol effects, including acute and chronic intoxication. Given peripherally, it counteracts the consequence of central dopamine system disturbances (receptor blockade), and induces serotonin release in substantia nigra. Therapeutic potential of BPC 157 as a cytoprotective agent is also seen in its capability to heal various wounds. Given directly into the stomach, BPC 157 instantly recovers disturbed lower esophageal and pyloric sphincter pressure in rats after 12-20 months of untreated esophagitis. All these could be suggestive for its role as a natural protectant in gastric juice with particular function throughout stomach distension.

Animals↗
PubMed2006

Isolated endogenous endophthalmitis due to a sporodochial-forming Phialemonium curvatum acquired through intracavernous autoinjections.

We report a case of endogenous endophthalmitis due to a sporodochial-forming species of Phialemonium curvatum. The infection led to the enucleation of the affected eye, but there was no evidence of systemic dissemination. The isolated P. curvatum produced aggregates of phialides, many occurring on coils or in verticils, which eventually develop into sporodochia. The initial and post-enucleation isolates revealed they were identical to strains of P. curvatum from Israel causing disseminated disease in patients practicing intracavernous autoinjections for the treatment of erectile dysfunction. The reported case had unusual clinical and microbiological features. Despite the route of acquisition and the lack of systemic antifungal therapy, the infection did not spread beyond the eye. The morphology of the phialides aggregates was also unique, and the distinction between Volutella and Acremonium is discussed. This case expands the spectrum of infections due to Phialemonium species, and reveals a novel way of developing fungal endophthalmitis.

Aged↗
PubMed2006

Symmetrical double aortic arch in a beagle puppy.

Double aortic arch denotes the persistence of both fourth aortic arches and has been reported as 'very rare' in the dog. Most reported cases have been seen in German shepherd dogs. An eight-week-old, male, 1.5-kg beagle presented with a three-week history of regurgitation and dyspnoea. A barium oesophagram showed severe oesophageal constriction cranial to the base of the heart, and a provisional diagnosis of a persistent right aortic arch was made. A left-sided fourth intercostal thoracotomy was performed. The ligamentum arteriosum was ligated and divided. The oesophagus was seen lying on the right-hand side of the aorta. Postoperatively, the puppy deteriorated and was euthanized. Postmortem revealed a double aortic arch entrapping both the oesophagus and trachea. The inexperienced surgeon could consider computed tomography or angiography to determine the exact vascular ring, and other possible concurrent vascular anomalies present, before surgery.

Animals↗
PubMed2005

Characteristics of candidaemia with Candida-albicans compared with non-albicans Candida species and predictors of mortality.

Candidaemia due to non-albicans Candida species is increasing in frequency. We describe 272 episodes of candidaemia, define parameters associated with Candida albicans and other Candida species, and analyse predictors associated with mortality. Patients with C. albicans (55%) had the highest fatality rate and frequently received immunosuppressive therapy, while patients with Candida parapsilosis (16%) had the lowest fatality and complication rates. Candida tropicalis (16%) was associated with youth, severe neutropenia, acute leukaemia or bone marrow transplantation, Candida glabrata (10%) was associated with old age and chronic disease, and Candida krusei (2%) was associated with prior fluconazole therapy. The overall fatality rate was 36%, and predictors of death by multi-variate analysis were shock, impaired performance status, low serum albumin and congestive heart failure. Isolation of non-albicans Candida species, prior surgery and catheter removal were protective factors. When shock was excluded from analysis, antifungal therapy was shown to be protective. Unlike previous concerns, infection with Candida species other than C. albicans has not been shown to result in an increased fatality rate.

Adolescent↗
PubMed2005

First report of suspected ethylene glycol poisoning in 2 dogs in South Africa.

Ethylene glycol (anti-freeze) toxicity is a serious emergency in both veterinary and human medicine. Ethylene glycol (E/G) is the active anti-freeze principle in radiator water additives. It is odourless, colourless and has a sweet taste. As little as 5 ml or 20 ml is sufficient to kill a cat or a dog, respectively. Ethylene glycol is rapidly absorbed and metabolised in the liver to oxalate, which is deposited as calcium oxalate in the kidneys causing irreversible damage. This report describes 2 dogs that were suspected to have ingested ethylene glycol. The report contains a description of the 3 stages of ethylene glycol toxicity as well as a short discussion of the treatment. Public awareness about the dangers of anti-freeze will help in limiting exposure of pets and humans to this potentially fatal toxin. Veterinarians need to be aware of anti-freeze toxicity as delayed recognition and treatment will lead to the death of the patient.

Acute Kidney Injury↗
PubMed2004

Risk factors for the development of extended-spectrum beta-lactamase-producing bacteria in nonhospitalized patients.

Although the risk factors for acquiring infection by extended-spectrum beta-lactamase (ESBL)-producing bacteria have been investigated in hospitalized patients, such risk factors have not been defined in the community setting. In this study, clinical data from a total of 311 nonhospitalized patients with community-acquired urinary tract infection (128 with ESBL-positive strains and 183 with ESBL-negative strains) were obtained. According to a multivariate analysis, the following were identified as independent risk factors: previous hospitalization in the past 3 months (OR=8.95, 95%CI, 3.77-21.25), antibiotic treatment in the past 3 months (OR=3.23, 95%CI, 1.76-5.91), age over 60 years (OR=2.65, 95%CI, 1.45-4.83), diabetes (OR=2.57, 95%CI, 1.20-5.51), male gender (OR=2.47, 95%CI, 1.22-5.01), Klebsiella pneumoniae infection (OR=2.31, 95%CI, 1.17-4.54), previous use of third-generation cephalosporins (P=0.014, OR=15.8, 95%CI, 1.7-143), previous use of second-generation cephalosporins (P<0.0001, OR=10.1, 95%CI, 4.2-24), previous use of quinolones (P=0.001, OR=4.1, 95%CI, 1.8-9.0), and previous use of penicillin (P=0.003, OR=4.0, 95%CI, 1.6-9.0).

Adolescent↗
PubMed2004

Intracellular survival of persistent group A streptococci in cultured epithelial cells.

Group A streptococcus (GAS) is the principle etiologic agent of bacterial pharyngotonsillitis and a wide range of other diseases. Failure to eradicate GAS from patients has been documented in 5-30% of patients with pharyngotonsillitis, in spite of the continued sensitivity of GAS to penicillin and other beta-lactams. It was recently proposed that eradication failure might be attributed to the ability of GAS to maintain an intracellular reservoir during antibiotic treatment. We have previously shown that strains derived from patients with bacterial eradication failure, despite antibiotic treatment (persistent strains), adhered to and were internalized by cultured epithelial cells more efficiently than strains that were successfully eradicated. Since, penicillin and other beta-lactams do not penetrate well into mammalian cells, intracellular survival of GAS is crucial in order to persist during prolonged antibiotic treatment. In this study, we compared the survival of GAS strains from cases of eradication failure and eradication success, using an epithelial cell culture model. We found that persistent strains show significantly increased intracellular survival, compared to the 'eradication success' strains. This finding supports the idea that an intracellular reservoir of GAS plays a role in the etiology of antibiotic eradication failure.

Anti-Bacterial Agents↗
PubMed2004

Predictors of adverse outcome from candidal infection in a tertiary care hospital.

OBJECTIVES: To retrospectively delineate predictors of adverse outcome by looking at the demographic features, therapy and outcome of systemic candida infection in a large tertiary care university-affiliated medical center. METHODS: We reviewed the clinical data on 186 inpatients with candidemia over a 6-year period. The major reason for their hospital admission was an underlying malignancy or an infection other than candidemia. RESULTS: Candida albicans, tropicalis, parapsilosis, glabrata and krusei caused 54, 22, 13, 8 and 3% of the candidemia episodes, respectively. The overall mortality was 42% and it was highest in patients suffering from candidemia of the glabrata species (73%). Forty-eight (63%) of the 76 patients who received no anti-fungal treatment died compared to 38 (34%) of 110 patients who were treated (P < 0.05). Predictors of adverse outcome were intensive care unit stay, renal failure, thrombocytopenia and the need for mechanical ventilation or inotropic support. CONCLUSIONS: We identified four predictors of mortality from candidemia infection. Their validity should be further assessed and the specific candida strains and their susceptibility need to be methodically identified. Our data support immediate initiation of therapy at first identification of infection.

Candida↗
PubMed2004

Disinfection with 10% povidone-iodine versus 0.5% chlorhexidine gluconate in 70% isopropanol in the neonatal intensive care unit.

AIM: The finding that 10% povidone-iodine skin disinfectant may compromise thyroid function in premature infants prompted its replacement with 0.5% chlorhexidine gluconate solution in 70% isopropanol. The objective of this study was to compare the incidence rates of true infection and contamination associated with the use of these two disinfectants in the neonatal intensive care unit. METHODS: The study population comprised two cohorts of infants admitted to our neonatal intensive care unit: 1) in 1992-1993 when only 10% povidone-iodine was used as a skin disinfectant, and 2) in 1995-1996 when only 0.5% chlorhexidine gluconate solution in 70% isopropanol was used. A retrospective chart review was conducted to determine whether all documented positive blood, CSF and suprapubic aspirate cultures indicated true infection or contamination. True infection was defined as clinical symptoms and/or laboratory abnormalities suggestive of sepsis, with positive blood, CSF or suprapubic aspirate cultures. RESULTS: 1146 infants were admitted during the study periods, 507 during the first period and 639 during the second. In the early group, 17.6% of infants had major malformations, 72.0% were premature and 25.2% had weights of < 1500 g. Corresponding percentages for the latter group were 16.0%, 80.6% and 32.9%, respectively. No statistically significant differences were found between the two research periods in rate of infants with positive blood cultures, true infections, or contamination. CONCLUSION: The use of 0.5% chlorhexidine gluconate solution in 70% isopropanol as a skin disinfectant is justified in neonatal intensive care units because it is not associated with an increased incidence of infections as opposed to 10% povidone-iodine and is devoid of detrimental effects.

Anti-Infective Agents, Local↗
PubMed2004

A retrospective case series of computer-controlled total intravenous anaesthesia in dogs presented for neurosurgery.

This article describes the anaesthetic management and use of total intravenous anaesthesia (TIVA) for neurosurgery in 4 dogs. Propofol in conjunction with morphine was used for the maintenance of anaesthesia. Anaesthesia was induced with either thiopentone or propofol. The program Stelpump (a target-controlled infusion program) was run on a laptop and connected to a syringe driver via an RS 232 cable. The program was found to be reliable and safe for the administration of TIVA in dogs. Invasive monitoring was required in order to monitor cardiovascular changes during surgery. Ventilation was controlled to maintain the end-tidal carbon dioxide below 40 mm Hg. The anaesthesia was characterised by haemodynamic stability. The haemodynamic stability was probably the result of the choice of TIVA and balanced anaesthesia. Intracranial pressure and oedema was controlled with dexamethasone, mannitol and ventilatory management either in combination or alone. Three dogs survived to hospital discharge and 1 dog was euthanased 2 weeks later due to tumour metastasis. The development and characterisation of the anaesthetic effects of TIVA needs to be elucidated in order to provide clinicians with rational guidelines for the appropriate use of TIVA in veterinary medicine.

Anesthesia, Intravenous↗
PubMed2002

New carbon nanofiber/graphite felt composite for use as a catalyst support for hydrazine catalytic decomposition.

Graphite felt supporting 40 nm diameter carbon nanofibers was synthesized and successfully used as a support for a high loaded iridium catalyst (30 wt%) in the decomposition of hydrazine; a strong mechanical resistance and a high thermal conductivity led to a very efficient and stable catalyst as compared to that used industrially, iridium supported on a high surface area alumina.

Journal Article↗
PubMed2002

Invasive group A streptococcal infections in a large tertiary center: epidemiology, characteristics and outcome.

BACKGROUND: Invasive group A streptococcal (GAS) infections are increasing alarmingly worldwide. PATIENTS AND METHODS: To determine the clinical and epidemiologic characteristics of invasive GAS in a large tertiary medical center, we retrospectively surveyed microbiology and medical records of patients with invasive GAS infections (isolation of Group A Streptococcus from a normally sterile site) treated in our hospital from January 1995 to December 1997. RESULTS: 70 patients with a median age of 48 years (range 2 months-88 years) were identified. Of the 70 identified, 53 (76%) were adults (age > or = 19 years). The most common co-morbid diseases for invasive GAS in adults were diabetes mellitus, congestive heart failure (CHF), malignancy and immunosuppression. A probable port of entry was identified in 31 (44%) of the cases. In children, varicella lesions were the major port of entry. Overall mortality rate was 17%: The difference in mortality between pediatric and adult cases was significant (0/17 vs 12/53, respectively; p = 0.03). Toxic shock syndrome (TSS) and necrotizing fasciitis were identified in 8.6% and 5.7% of the cases, respectively, with mortalities of 83.3% and 25%. Hyponatremia and hypocalcemia were more frequently observed among the severely ill. CONCLUSION: Invasive GAS infections tend to have an unexpected course and a broad clinical spectrum, ranging from local skin or pharyngeal involvement to deeply invasive fasciitis with TSS and high mortality. The elderly and those with underLying medical conditions are at utmost rsk for invasive GAS. Clear-cut guidelines for early therapeutic strategy, i.e. antibiotic administration and preemptive hospital admission are needed for community-based physicians.

Adolescent↗
PubMed2002

Efficacy and safety of a factor VIII-von Willebrand factor concentrate 8Y: stability, bacteriological safety, pharmacokinetic analysis and clinical experience.

The present study was undertaken to evaluate stability, pharmacokinetic profile and efficacy of continuous infusion of 8Y in patients with different types of von Willebrand disease (vWD). Following reconstitution, 8Y levels of von Willebrand factor ristocetin cofactor (vWF:Rco), vWF antigen and factor VIII coagulant activity (FVIII:C) decreased to about 80% of the baseline levels; addition of low molecular weight heparin decreased the level of FVIII:C even further. Reconstituted 8Y was found to be sterile for up to 6 days postreconstitution. Ten vWD patients (four with type 2A, three with type 3, two with type 1 and one with 2N) underwent pharmacokinetic analysis. The recovery of vWF: RCo was significantly lower in patients with type 3 vWD (1.4 +/- 0.05% U(-1) kg(-1)) compared with that of the patients with types 1 (2.3 +/- 0.52% U(-1) kg(-1)) or 2A (2.0 +/- 0.06% U(-1) kg(-1)) vWD (P = 0.015). Type 3 vWD patients exhibited significantly higher vWF:RCo clearance (5.1 +/- 1.1 mL kg(-1) h(-1)) compared with that of patients with type 2A (2.8 +/- 0.7 mL kg(-1) h(-1)) and type 1 (2.6 +/- 1.0 mL kg(-1) h(-1)) vWD (P = 0.028). Accordingly, terminal half-life was lower in patients with type 3 vWD (8.0 +/- 0.6 h(-1)) compared with type 2A (12.7 +/- 5.9 h(-1)) or type 1 (14 +/- 1.2 h(-1)) vWD patients. Multimeric pattern of vWF from patients' plasma was similar to that of 8Y. In two patients treated with 8Y by continuous infusion for prevention or treatment of bleeding haemostasis was achieved. Thus, 8Y is suitable and haemostatically effective for continuous infusion treatment in patients with vWD.

Adult↗
PubMed2001

Survival following coronary angioplasty versus coronary artery bypass surgery in anatomic subsets in which coronary artery bypass surgery improves survival compared with medical therapy. Results from the Bypass Angioplasty Revascularization Investigation (BARI).

OBJECTIVES: We sought to compare survival after coronary artery bypass graft (CABG) and percutaneous transluminal coronary angioplasty (PTCA) in high-risk anatomic subsets. BACKGROUND: Compared with medical therapy, CABG decreases mortality in patients with three-vessel disease and two-vessel disease involving the proximal left anterior descending artery (LAD), particularly if left ventricular (LV) dysfunction is present. How survival after PTCA and CABG compares in these high-risk anatomic subsets is unknown. METHODS: In the Bypass Angioplasty Revascularization Investigation (BARI), 1,829 patients with multivessel disease were randomized to an initial strategy of PTCA or CABG between 1988 and 1991. Stents and IIb/IIIa inhibitors were not utilized. Since patients in BARI with diabetes mellitus had greater survival with CABG, separate analyses of patients without diabetes were performed. RESULTS: Seven-year survival among patients with three-vessel disease undergoing PTCA and CABG (n = 754) was 79% versus 84% (p = 0.06), respectively, and 85% versus 87% (p = 0.36) when only non-diabetics (n = 592) were analyzed. In patients with three-vessel disease and reduced LV function (ejection fraction <50%), seven-year survival was 70% versus 74% (p = 0.6) in all PTCA and CABG patients (n = 176), and 82% versus 73% (p = 0.29) among non-diabetic patients (n = 124). Seven-year survival was 87% versus 84% (p = 0.9) in all PTCA and CABG patients (including diabetics) with two-vessel disease involving the proximal LAD (n = 352), and 78% versus 71% (p = 0.7) in patients with two-vessel disease involving the proximal LAD with reduced LV function (n = 72). CONCLUSION: In high-risk anatomic subsets in which survival is prolonged by CABG versus medical therapy, revascularization by PTCA and CABG yielded equivalent survival over seven years.

Aged↗
PubMed2001

Efficacy of dofetilide in the treatment of atrial fibrillation-flutter in patients with reduced left ventricular function: a Danish investigations of arrhythmia and mortality on dofetilide (diamond) substudy.

BACKGROUND: In patients with left ventricular dysfunction, atrial fibrillation and flutter (AF and AFl, respectively) are common arrhythmias associated with increased morbidity and mortality. The present study investigated the potential of dofetilide in AF-AFl patients with left ventricular dysfunction to restore and maintain sinus rhythm, which might reduce mortality and hospitalizations. METHODS AND RESULTS: In the Danish Investigations of Arrhythmia and Mortality ON Dofetilide (DIAMOND) studies, 506 patients were in AF-AFl at baseline. Over the course of study, cardioversion occurred in 148 (59%) dofetilide- and 86 (34%) placebo-treated patients. In these patients, the probability of maintaining sinus rhythm for 1 year was 79% with dofetilide versus 42% with placebo (P<0.001). Dofetilide had no effect on all-cause mortality, but restoration and maintenance of sinus rhythm was associated with significant reduction in mortality (risk ratio [RR], 0.44; 95% CI, 0.30 to 0.64; P<0.0001). In addition, dofetilide therapy was associated with a significantly lower risk ratio versus placebo for either all-cause (RR, 0.70; 95% CI, 0.56 to 0.89; P</=0.005) or congestive heart failure (RR, 0.69; 95% CI, 0.51 to 0.93; P</=0.02) rehospitalization. CONCLUSIONS: Dofetilide is safe and increases the probability of obtaining and maintaining sinus rhythm in patients with structural heart disease. The present study suggests that restoration of sinus rhythm is associated with improved survival.

Administration, Oral↗
PubMed2001

Clinical prevalence, antimicrobial susceptibility, and geographic resistance patterns of enterococci: results from the SENTRY Antimicrobial Surveillance Program, 1997-1999.

As part of the SENTRY Antimicrobial Resistance Surveillance Program, a total of 4998 strains of enterococci isolated from 1997 to 1999 were processed. The occurrence of enterococcal infections by species and site of infection was analyzed, as were the occurrence of vancomycin-resistant enterococci (VRE) and their resistance phenotypes and genotypes. Trends in antimicrobial susceptibility to a variety of agents (including experimental compounds) were also reported. Enterococci accounted for >9% of isolates from all bloodstream infections (BSIs) in North America. Ampicillin was active against strains from Latin America and Europe but not against those from the United States and Canada. US isolates were considerably more resistant to vancomycin (17% resistant strains in 1999) than were those from patients in the rest of the world. The highest proportion of VRE was observed among BSI isolates (81.7%). Quinupristin-dalfopristin, chloramphenicol, and doxycycline were the most active agents tested against VRE. The results of this study confirm the worldwide trend in increasing occurrence of enterococci and the emerging pattern of antimicrobial resistance among such isolates.

Anti-Bacterial Agents↗