Adolescent and young adult cancer: principles of care.

Adolescents and young adults (ayas) with cancer in active treatment face a number of barriers to optimal care. In the present article, we focus on the 3 critical domains of care for ayas-medical, psychosocial, and research-and how changes to the system could overcome barriers. We summarize the current literature, outline recommended principles of care, raise awareness of barriers to optimal care, and suggest specific changes to the system to overcome those barriers in the Canadian context. Many of the recommendations can nevertheless be applied universally. These recommendations are endorsed by the Canadian Task Force on Adolescents and Young Adults with Cancer and build on outcomes from two international workshops held by that group.

First Attempt of Sequential Living Donor Liver and Hematopoietic Stem Cell Transplantation in a Child With Advanced Hepatocellular Carcinoma: Case Report.

Effective therapeutic options for advanced hepatocellular carcinoma are limited. Hematopoietic stem cell transplantation may offer a graft-versus-tumor effect. Combined liver and hematopoietic stem cell transplantation from the same donor with preparatory conditioning may promote tolerogenicity to the liver allograft and offers the potential for immunosuppression withdrawal. We report our experience with the use of this approach in a pediatric patient with invasive hepatocellular carcinoma and pulmonary metastases who underwent a living-donor liver transplantation followed by reduced-toxicity myeloablative conditioning and hematopoietic stem cell transplant from the same parental donor. Neutrophil engraftment and full donor chimerism was achieved without liver allograft dysfunction. Despite normal liver function and marrow engraftment, the patient succumbed to multisystem organ failure from disseminated toxoplasmosis. At autopsy, there was no histologic evidence of tumor recurrence. No pulmonary nodules were found. Regardless of the unfortunate overall result, this case demonstrates preliminary feasibility of sequential living-donor liver transplantation and hematopoietic stem cell transplantation for unresectable and metastasized hepatic tumors. Future studies in select pediatric patients require evaluation of the optimal conditioning regimen and prevention strategies for opportunistic infections to determine both graft-versus-tumor effect on hepatic tumors and durability of tolerogenicity and possible immunosuppression withdrawal.

Evidence for the in vivo degradation of human respiratory mucins during Pseudomonas aeruginosa infection.

The comparison of distribution of glycopeptides of sputa from patients suffering from various chronic hypersecretions has already shown an increased acidity with a decreased proportion of neutral glycopeptides in the respiratory secretions of patients suffering from cystic fibrosis, as compared to those of patients with chronic bronchitis. In order to find out whether this decrease is specific to cystic fibrosis mucins or whether it is due to a degradation of mucus by Pseudomonas aeruginosa, which infects most of the sputa from patients with this disease, mucus glycopeptides from patients with different chronic bronchial disorders, infected by Pseudomonas or not, were prepared and fractionated by ion-exchange chromatography. The neutral fraction, which has never been studied in detail, was gel-filtered, and provided two fractions, one containing true mucin glycopeptides and the other containing a mixture of peptides and glycopeptides with a lower molecular mass. In the Pseudomonas-infected samples, the true mucin glycopeptide fraction was greatly diminished as compared to this same fraction in non-Pseudomonas-infected samples; this was not specific to cystic fibrosis secretions. In contrast, the glycopeptide fraction with a lower molecular mass was greatly increased in all the Pseudomonas-infected samples. Polyacrylamide gel electrophoresis of this second fraction showed unique glycopeptide bands between 40-50 kDa in the Pseudomonas-infected samples, regardless of the origin of the samples. These bands were revealed by an antibody directed against whole cystic fibrosis mucin. Infected chronic bronchitis sputa and cystic fibrosis samples without P. aeruginosa did not show these bands. These studies therefore suggest that there are P. aeruginosa-associated changes in mucins which may result from degradation of mucins.

Rocky Mountain spotted fever and jaundice. Two consecutive cases acquired in Florida and a review of the literature on this complication.

Rocky mountain spotted fever is increasing in Florida, a state that has had few cases in the past. The typical clinical illness has been well described, but jaundice has been rarely reported. In two patients with illnesses resembling leptospirosis, jaundice appeared on the sixth and ninth day of illness, and peak bilirubin levels were between 7 and 9 mg/100 ml. Liver biopsy specimen from one patient showed a nonspecific hepatitis. Hemolysis and renal dysfunction may have contributed to the production of jaundice in these patients. Fourteen instances of jaundice were reported in 43 autopsied cases as of 1941, but since that time only rare mention of jaundice has been made.

Clinical experience with single agent and combination regimens in the management of infection in the febrile neutropenic patient.

Choice of antibiotic therapy for the management of infection in the neutropenic patient continues to challenge the clinician. The shift toward gram-positive organisms and the continuing need to provide gram-negative coverage demands the use of an agent or agents that provide coverage for the spectrum of potential infecting organisms. Cefepime is an extended-spectrum fourth-generation cephalosporin that has good activity against gram-positive and gram-negative organisms; in addition, it resists degradation by Bush group 1 beta-lactamases. These properties make this agent a promising candidate for empiric therapy with febrile neutropenic patients. Data presented in this article are from febrile neutropenic cancer patients enrolled into two randomized, prospective, nonblinded comparative U.S. clinical trials. Patients were randomized to receive cefepime (2 g thrice daily) or a comparator regimen of either ceftazidime (2 g thrice daily) or piperacillin + gentamicin (3 g every 4 hours + 1.5 mg/kg every 8 hours). When indicated, vancomycin was added to the regimen. A total of 109 febrile episodes were treated with cefepime and 107 episodes were treated with the comparator regimens. Neutropenia (< or = 500 PMNs/mm3) persisted for > or = 10 days in >40% of episodes and severe neutropenia (< or = 100 PMNs/mm3) in >25%. More than 40% of the total number of episodes were documented bacterial infections. These characteristics did not differ among treatment groups. Duration of therapy was similar in both groups (median: cefepime, 9 days; comparators, 11 days). In >40% of episodes, patients received study therapy without addition of other antibacterials (cefepime, 46%; comparators, 41%). Vancomycin was added in almost half of all the episodes (cefepime, 45%; comparators, 53%). Patients became afebrile by the fourth day of study therapy in approximately 60% of episodes (cefepime, 58%; comparators, 60%). In approximately 75% of the episodes, patients had a satisfactory response at the end of therapy (cefepime, 74%; comparators, 76%); and following approximately 90% of episodes, patients survived for >30 days (cefepime, 90%; comparators, 92%). Eradication rates were similar for all pathogens for cefepime and comparator agents. There were similar numbers of superinfecting organisms in each treatment arm; most involved gram-positive organisms. These multiple measures of efficacy suggest that initial empiric cefepime monotherapy is comparable to the pooled experience with standard therapies and that antibacterial modifications occur with similar frequency for cefepime compared with standard empiric regimens.

Necrotizing soft-tissue infections caused by marine vibrios.

Halophilic, noncholera marine Vibrio bacteria can cause septicemia, gastroenteritis, cellulitis, and necrotizing fasciitis. We describe six patients with necrotizing fasciitis and review 12 cases described previously. The 18 patients included 14 men and four women. Their ages ranged from 32 to 79 years (average 58.1 years). Eleven patients were older than 55 years. Nine infections were caused by V. vulnificus, three by V. parahaemolyticus, and one by V. alginolyticus. In five cases the Vibrio species was not identified. Twelve patients had associated conditions that might have made them more susceptible to these infections, such as cirrhosis, steroid therapy, hemochromatosis, and multiple myeloma. These infections usually occur in apparently insignificant wounds (puncture wounds, insect bites) exposed to sea water or fish. Treatment is by debridement and antibiotic therapy. Three patients required amputation to control the infection. Six (33.3%) of the 18 patients died.

Pneumonia in the compromised host including cancer patients and transplant patients.

Pneumonia remains a major cause of morbidity and mortality in the immunocompromised host. The type and timing of immunosuppression will predispose the patient to infections with certain pathogens. This article discusses the types of immunosuppression and their infectious and noninfectious implications. Key points of the most commonly involved pathogens are mentioned. Finally, an approach to diagnosis and empiric therapy is discussed.

Comparison of the activity of two broad-spectrum cephalosporins tested against 2,299 strains of Pseudomonas aeruginosa isolated at 38 North American medical centers participating in the SENTRY Antimicrobial Surveillance Program, 1997-1998.

Pseudomonas aeruginosa is an important nosocomial pathogen. Resistance to certain beta-lactam antimicrobial agents among P. aeruginosa is increasing. The SENTRY Antimicrobial Surveillance Program was designed to employ a network of hospitals in the United States, Canada, Latin America, and Europe to monitor the predominant bacterial and fungal pathogens and antimicrobial susceptibility patterns associated with community-acquired and nosocomial bloodstream, respiratory tract, wound, and urinary tract infections. The purpose of this analysis of SENTRY results was to extract information on the current North American susceptibility pattern of P. aeruginosa for two antipseudomonal cephalosporins, ceftazidime, and cefepime. Clinical isolates were provided by 30 centers in the United States (grouped into five regions) and eight centers in Canada. Susceptibility testing was performed at a central reference laboratory by using broth microdilution methods and interpretive criteria specified by the National Committee for Clinical Laboratory Standards. Of the 34, 530 North American bacterial isolates tested during 1997 and 1998, 2299 (6.7%) were P. aeruginosa. There were no substantial differences in regional rates of P. aeruginosa susceptibility to ceftazidime (range 78.8-81.9%) or cefepime (range 80.0-83.4%) The percentage of resistant isolates among the 1784 United States isolates was 13.3% for ceftazidime versus 7.1% for cefepime (p < 0.05). It is essential to continue surveillance of the in vitro efficacy of these and other beta-lactam agents against P. aeruginosa because of the clinical importance of these safe and broad-spectrum cephems used alone or in combination in current clinical practice.

In vitro activity of selected cephalosporins and erythromycin against staphylococci and pneumococci isolated at 38 North American medical centers participating in the SENTRY Antimicrobial Surveillance Program, 1997-1998.

The SENTRY Antimicrobial Surveillance Program employs a worldwide network of hospitals to monitor the predominant bacterial and fungal pathogens and antimicrobial susceptibility patterns associated with nosocomial and community-acquired bloodstream, respiratory tract, wound, and urinary tract infections. The purpose of this analysis of SENTRY data is to extract information on the current North American susceptibility patterns of pneumococci and oxacillin-susceptible staphylococci from the comprehensive SENTRY program database. Clinical isolates were provided by 30 centers in the United States (grouped into five regions) and eight centers in Canada. Susceptibility testing was performed at a central reference laboratory using broth microdilution methods and interpretive criteria specified by the National Committee for Clinical Laboratory Standards. Of 34 530 North American bacterial isolates tested during 1997 and 1998, 565 (1.6%) were oxacillin-susceptible, coagulase-negative staphylococci (CoNS). Cefazolin, cefepime, and ceftriaxone all had excellent activity against these CoNS (97.3%-99. 3% susceptible), and 90.4% were susceptible to ceftazidime. A total of 4404 isolates (12.8%) were oxacillin-susceptible Staphylococcus aureus. Overall, 98.9% to 99.2% were susceptible to cefazolin, cefepime, and ceftriaxone; ceftazidime did not have acceptable activity against these S. aureus. Streptococcus pneumoniae accounted for 1665 (4.8%) of North American SENTRY isolates. A total of 1212 isolates (72.8%) were fully susceptible to penicillin (MIC /= 2 microg/ml). The rate of penicillin susceptibility was highest in Canada, and lowest in the South Central and South East regions of the United States. Cefepime, cefuroxime, ceftazidime, and erythromycin all demonstrated excellent efficacy (94%-99.8% susceptibility) against fully penicillin-susceptible isolates of S. pneumoniae. Among pneumococci with intermediate penicillin resistance, 88% were susceptible to cefepime, 92% to cefotaxime, and only 14% to ceftazidime. None of the antimicrobial agents in this analysis demonstrated adequate activity against fully penicillin-resistant pneumococci. In summary, the fourth-generation cephalosporin, cefepime, demonstrated consistently excellent efficacy against oxacillin-susceptible staphylococci and most pneumococci, and remains an appropriate choice for empiric therapy of serious infections.

In vitro efficacy of six cephalosporins tested against Enterobacteriaceae isolated at 38 North American medical centres participating in the SENTRY Antimicrobial Surveillance Program, 1997-1998.

The SENTRY Antimicrobial Surveillance Program is an ongoing international collaboration that monitors the predominant bacterial and fungal pathogens and antimicrobial susceptibility patterns associated with community-acquired and nosocomial infections. SENTRY data on the current cephalosporin susceptibility patterns (1997-98) of North American isolates of clinically important Enterobacteriaceae were analyzed. Susceptibility to a selection of cephalosporins was assessed at a central laboratory using reference broth microdilution methods and interpretive criteria specified by the National Committee for Clinical Laboratory Standards. The third- and fourth-generation cephalosporins tested demonstrated excellent activity against Escherichia coli and Klebsiella pneumoniae, whereas some of the older agents maintained good efficacy. Extended spectrum beta-lactamases were detected in all regions of the United States and Canada (1.8-10.7%). Cefepime was the most active agent tested against pathogens with the potential for enzyme-mediated resistance due to Amp C. The third-generation agents maintained acceptable efficacy against Serratia marcescens, but were less effective against Citrobacter and Enterobacter species. The older cephalosporins were generally inadequate against these pathogens, in contrast to cefepime, which was the widest spectrum cephalosporin overall. Some significant regional variations in spectrum were detected.

Cost effectiveness of cephalosporin monotherapy and aminoglycoside/ureidopenicillin combination therapy. For the treatment of febrile episodes in neutropenic patients.

OBJECTIVE: To assess the relative cost effectiveness of cephalosporin monotherapy options and aminoglycoside/ureidopenicillin combination therapy for the treatment of febrile episodes in adult patients with neutropenia. DESIGN AND SETTING: This was a retrospective cost-effectiveness analysis conducted from the institutional perspective. METHODS: The analysis was based on 741 febrile episodes in adult patients with neutropenia enrolled in 5 randomised trials: 3 comparing monotherapy with ceftazidime or cefepime, and 2 comparing cefepime monotherapy versus aminoglycoside/ureidopenicillin combination therapy. Resource utilisation included costs for study antibacterials, treatment of adverse effects and failures, and hospitalisation. The primary end-point was the overall cost of treatment per patient. Cost-effectiveness ratios were also analysed. RESULTS: No significant differences in clinical success rates were detected. Median per-patient costs in the monotherapy comparisons were $US7849 for cefepime and $US7788 for ceftazidime [1997 values; not significantly different (NS)]. Corresponding costs for the monotherapy versus combination therapy comparisons were $US9780 for cefepime and $US10 159 for gentamicin/ureidopenicillin (NS). Despite a higher acquisition cost for cefepime, there were no statistically significant differences in cost effectiveness compared with either ceftazidime monotherapy or gentamicin/ureidopenicillin combination therapy. Sensitivity analyses revealed that monotherapy can be cost effective compared with combination therapy in many situations. CONCLUSION: There were no economic differences between the 3 regimens tested. Therefore drug cost should not be a deciding factor when choosing antibacterial therapy for the treatment of febrile episodes in adult patients with neutropenia.

Acinetobacter calcoaceticus variety anitratus: an increasing nosocomial problem.

Acinetobacter calcoaceticus var anitratus is an increasing nosocomial problem in some institutions. Duirng a recent 16-month period, we observed 15 patients with blood isolates of this organism. Thirteen of these patients acquired the organism from the hospital environment. Eleven of these represented real disease and concurrent growth of the organism from another site was predictive of infection (P less than 0.03). A review of laboratory records showed that there was a three-fold increase in nonblood isolates of this organism from hospitalized patients in 1975 and 1976, as compared to 1972 (P less than 0.0001), and a marked seasonal effect was noted, with increased isolations during the summer. Aminoglycoside resistance had increased considerably with 25% of nonblood isolates being resistant to gentamicin and 16% resistant to tobramycin despite its restriction; blood isolates were uniformly susceptible to gentamicin and tobramycin. Reporting of A anitratus as a nosocomial pathogen and serotyping of isolates may be useful to further define its role in nosocomial infections.

Nosocomial infections and bacterial antibiotic resistance in a university equine hospital.

A base-line study of bacteria isolated from horses admitted to the Veterinary Medical Teaching Hospital during a 6-month period was performed to determine the extent of multiresistant nosocomial infections caused by gram-negative aerobic bacteria other than Salmonella spp. Results of this study indicated that 21.9% of the 105 horses from which cultures and sensitivities were available had developed nosocomial gram-negative aerobic infections, with high rates of resistance to gentamicin, kanamycin, and trimethoprim sulfadiazine, three of the most often prescribed antibiotics in this hospital. In addition, a prospective study of antibiotic-resistant bacteria of fecal origin was performed to determine whether there was a change in the degree of antibiotic resistance of a horse's intestinal flora while the horse was hospitalized. Bacterial culturing for gram-negative lactose fermenting bacteria was done on fecal specimens collected directly from the rectum on day 1 and day 7 of a horse's hospitalization. Susceptibility testing was done on each isolant. Of the 24 paired fecal specimens obtained, Escherichia coli and Klebsiella sp isolated on day 7 were resistant to a significantly higher number of antibiotics than day 1 isolants (P = 0.003, P = 0.043, respectively).

Transcriptional response of mucoid Pseudomonas aeruginosa to human respiratory mucus.

UNLABELLED: Adaptation of bacterial pathogens to a host can lead to the selection and accumulation of specific mutations in their genomes with profound effects on the overall physiology and virulence of the organisms. The opportunistic pathogen Pseudomonas aeruginosa is capable of colonizing the respiratory tract of individuals with cystic fibrosis (CF), where it undergoes evolution to optimize survival as a persistent chronic human colonizer. The transcriptome of a host-adapted, alginate-overproducing isolate from a CF patient was determined following growth of the bacteria in the presence of human respiratory mucus. This stable mucoid strain responded to a number of regulatory inputs from the mucus, resulting in an unexpected repression of alginate production. Mucus in the medium also induced the production of catalases and additional peroxide-detoxifying enzymes and caused reorganization of pathways of energy generation. A specific antibacterial type VI secretion system was also induced in mucus-grown cells. Finally, a group of small regulatory RNAs was identified and a fraction of these were mucus regulated. This report provides a snapshot of responses in a pathogen adapted to a human host through assimilation of regulatory signals from tissues, optimizing its long-term survival potential. IMPORTANCE: The basis for chronic colonization of patients with cystic fibrosis (CF) by the opportunistic pathogen Pseudomonas aeruginosa continues to represent a challenging problem for basic scientists and clinicians. In this study, the host-adapted, alginate-overproducing Pseudomonas aeruginosa 2192 strain was used to assess the changes in its transcript levels following growth in respiratory CF mucus. Several significant and unexpected discoveries were made: (i) although the alginate overproduction in strain 2192 was caused by a stable mutation, a mucus-derived signal caused reduction in the transcript levels of alginate biosynthetic genes; (ii) mucus activated the expression of the type VI secretion system, a mechanism for killing of other bacteria in a mixed population; (iii) expression of a number of genes involved in respiration was altered; and (iv) several small regulatory RNAs were identified, some being mucus regulated. This work highlights the strong influence of the host environment in shaping bacterial survival strategies.

The role of bacterial adhesion in cystic fibrosis including the staphylococcal aspect.

The bacteriology of cystic fibrosis shows a unique and predictable progression of colonizing micro-organisms. The reason for this sequence is still not known, but thought must be given to the idea that it may be related to the genetic disorder in some way. If this were to be true, an understanding of the colonization mechanisms at all stages in this progression could provide valuable insights for the development of novel therapies. As far as can be ascertained from published studies, mucus is the site of colonization in cystic fibrosis. While there is no doubt that the major pathogen, Pseudomonas aeruginosa, adheres to injured cells more avidly than to intact cells, the overwhelming evidence indicates that it also attaches more avidly to mucus than to intact airway cells by means of specific adhesin-receptor mechanisms. Studies with Staphylococcus aureus, the other major pathogen, are also in progress. These indicate that this organism also has an affinity for mucus. At this time the studies suggest a lesser affinity than P. aeruginosa, at least with adult mucins. These two organisms do not however appear to share the same receptor. In addition to these two major pathogens, Haemophilus influenzae and Streptococcus pneumoniae, pathogens of lesser importance also adhere to mucus. Therefore adhesion to mucus or mucins may be a recurring theme in all airway colonization. A knowledge of the factors which control these tropisms ought to provide insights into the bacterial specificity seen in cystic fibrosis and other diseases.

Is monotherapy for febrile neutropenia still a viable alternative?

Monotherapy for empirical treatment of febrile neutropenia is effective and often less costly than combination therapy but remains controversial. The controversy results from observations that combination therapy for Pseudomonas aeruginosa improved outcomes, and this approach became a standard. Many subsequent publications, including the Infectious Diseases Society of America guidelines for febrile neutropenia, now support monotherapy. However, changes in the pathogens involved in febrile neutropenia and in their resistance prompt a reevaluation. In the evaluation of new antibiotics, recent trials comparing either cefepime or meropenem with combination therapy or with ceftazidime confirm that monotherapy remains a viable therapeutic approach, with infectious mortality in the 5% range in all arms. The choice of monotherapy should, however, be made on the basis of resistance patterns seen in an institution. The agent selected should be very active against the organisms that are likely to cause rapidly fatal infections, and clinicians must be prepared to modify monotherapy as appropriate.

Further characterization of the tracheal receptor for Pseudomonas aeruginosa.

The purpose of this study was to obtain more information on the nature of the macromolecule to which Pseudomonas aeruginosa adheres. Acid-injured tracheal epithelium was treated with trypsin or lipase to determine whether the receptor molecule was a protein or a lipid. Lipase treatment significantly reduced adherence to these cells, whereas trypsin had no effect. Since the receptor appeared to be a lipid containing sialic acid, gangliosides were used to test whether they would inhibit adherence. Crude ganglioside preparations inhibited adherence in a dose-dependent manner when added to the bacteria before exposure to tracheal cells. Lastly, fibronectin, which presumably binds to gangliosides, significantly reduced the adherence of these organisms. According to these findings Pseudomonas aeruginosa appears to adhere to a sialic acid-containing glycolipid on cell surfaces, probably a ganglioside.

Bilateral pulmonary infiltrates in association with disseminated actinomycosis.

The most common infectious cause of bilateral upper-lobe pulmonary disease is tuberculosis. However, we recently encountered a patient with bilateral apical infiltrates and multiple soft-tissue abscesses caused by Actinomyces odontolyticus. Other findings included fever, weight loss, and leukocytosis, and the patient's only known source of immunosuppression was a long history of alcoholism. There was no history of diabetes, steroid use, or other chronic underlying disease. The diagnosis was made by culture of drainage fluid from one abscess. Therapy with intravenous penicillin G led to rapid clinical improvement and reduction in the infiltrates. To our knowledge, the presentation of pulmonary infection, with bilateral apical infiltrates due to A. odontolyticus has not been previously reported in the medical literature.