Whole-genome sequencing of carbapenem-resistant Enterobacterales isolates in southeast Louisiana reveals persistent genetic clusters spanning multiple locations

BACKGROUND

We investigated 51 g-negative carbapenem-resistant Enterobacterales (CRE) isolates collected from 22 patients over a five-year period from six health care institutions in the Ochsner Health network in southeast Louisiana.

METHODS

Short genomic reads were generated using Illumina sequencing and assembled for each isolate. Isolates were classified as Enterobacter spp. (n = 20), Klebsiella spp. (n = 30), and Escherichia coli (n = 1) and grouped into 19 different multi-locus sequence types (MLST). Species and patient-specific core genomes were constructed representing ∼50% of the chromosomal genome.

RESULTS

We identified two sets of patients with genetically related infections; in both cases, the related isolates were collected > 6 months apart, and in one case, the isolates were collected in different locations. On the other hand, we identified four sets of patients with isolates of the same species collected within 21 days from the same location; however, none had genetically related infections. Genes associated with resistance to carbapenem drugs (blaKPC and/or blaCTX-M-15) were found in 76% of the isolates. We found three blaKPC variants (blaKPC-2, blaKPC-3, and blaKPC-4) associated with four different Enterobacter MLST variants, and two blaKPC variants (blaKPC-2, blaKPC-3) associated with seven different Klebsiella MLST variants.

CONCLUSIONS

Molecular surveillance is increasingly becoming a powerful tool to understand bacterial spread in both community and clinical settings. This study provides evidence that genetically related infections in clinical settings do not necessarily reflect temporal associations, and vice versa. Our results also highlight the regional genomic and resistance diversity within related bacterial lineages.

Comparing antimicrobial resistant genes and phenotypes across multiple sequencing platforms and assays for Enterobacterales clinical isolates

INTRODUCTION

Whole genome sequencing (WGS) of bacterial isolates can be used to identify antimicrobial resistance (AMR) genes. Previous studies have shown that genotype-based AMR has variable accuracy for predicting carbapenem resistance in carbapenem-resistant Enterobacterales (CRE); however, the majority of these studies used short-read platforms (e.g. Illumina) to generate sequence data. In this study, our objective was to determine whether Oxford Nanopore Technologies (ONT) long-read WGS would improve detection of carbapenem AMR genes with respect to short-read only WGS for nine clinical CRE samples. We measured the minimum inhibitory breakpoint (MIC) using two phenotype assays (MicroScan and ETEST) for six antibiotics, including two carbapenems (meropenem and ertapenem) and four non-carbapenems (gentamicin, ciprofloxacin, cefepime, and trimethoprim/sulfamethoxazole). We generated short-read data using the Illumina NextSeq and long-read data using the ONT MinION. Four assembly methods were compared: ONT-only assembly; ONT-only assembly plus short-read polish; ONT + short-read hybrid assembly plus short-read polish; short-read only assembly.

RESULTS

Consistent with previous studies, our results suggest that the hybrid assembly produced the highest quality results as measured by gene completeness and contig circularization. However, ONT-only methods had minimal impact on the detection of AMR genes and plasmids compared to short-read methods, although, notably, differences in gene copy number differed between methods. All four assembly methods showed identical presence/absence of the blaKPC-2 carbapenemase gene for all samples. The two phenotype assays showed 100% concordant results for the non-carbapenems, but only 65% concordance for the two carbapenems. The presence/absence of AMR genes was 100% concordant with AMR phenotypes for all four non-carbapenem drugs, although only 22%-50% sensitivity for the carbapenems.

CONCLUSIONS

Overall, these findings suggest that the lack of complete correspondence between CRE AMR genotype and phenotype for carbapenems, while concerning, is independent of sequencing platform/assembly method.

COVID-19 vaccination hesitancy in Kazakhstan

Background

COVID-19 vaccine hesitancy is a major problem worldwide that impedes vaccine uptake. We explored factors associated with vaccine hesitancy in Kazakhstan.

Methods

We conducted a cross-sectional face-to-face survey of 991 adults in Kazakhstan in July 2021, using quota sampling of respondents over 18 years old reflecting the distribution of gender, age, residence type, and geographical regions of Kazakhstan, according to the 2020 census.

Results

Over two third (68.4%) of the sample was vaccine hesitant; 22.11% - received a vaccine (18.6%-Sputnik V, 2%-Hayat-Vax, 0.9%-QazCovid and 0.6%- CoronaVac). We used logistic regression to explore factors that were associated with vaccine hesitancy, adjusting age, education, employment, type of residence, self-reported COVID-19. The odds of not being vaccine hesitant were higher among those who had a higher perception that the COVID-19 vaccine was important for health OR = 2.66 (95%CI:2.24,3.17), higher belief in vaccine safety/effectiveness OR = 3.16 (95%CI:2.57,3.89), higher trust in government/health providers OR = 3.32 (95%CI:2.72,4.05), higher trust in official sources of information OR = 1.16 (95%CI:1.12,1.21), higher adherence to preventive measures OR = 1.05 (95%CI:1.03,1.08), knew someone diagnosed with COVID-19 OR = 1.36 (95%CI:1.01,1.82), or who died of COVID-19 OR = 1.47 (95%CI:1.04,2.08), had been ever tested for COVID-19 OR = 1.75 (95%CI:1.30,2.35), had ever received flu vaccine OR = 2.16 (95%CI:1.62,2.88), among health professionals OR = 2.76 (95%CI:1.38,5.51), and who had lower vaccine conspiracy beliefs OR = 0.48 (95% CI:0.40,0.58).

Conclusions

Vaccine accepting individuals held positive beliefs about the COVID-19 vaccine, had greater trust in government/official sources of information/health care workers, had greater exposure to COVID-19. Interventions aimed at reducing vaccine hesitancy need to address sources people find credible and may need to target individuals who have had limited exposure to the risks of COVID-19.

Key messages

• Strategies to increase trust in government/ health care workers and official sources of information can be an effective approach to reduce COVID-19 vaccination hesitancy.

• Interventions to reduce COVID-19 vaccination hesitancy should target individuals who have had limited exposure to the risks of COVID-19.

Arrhythmogenic right ventricular cardiomyopathy in Bulldogs: Evaluation of clinical and histopathologic features, progression, and outcome in 71 dogs (2004-2016)

OBJECTIVES

This study aimed to characterize the clinical and histopathological features of arrhythmogenic right ventricular cardiomyopathy (ARVC) in English Bulldogs, American Bulldogs, and Bulldog-type mixed breed dogs and assess affected Bulldogs for a striatin gene mutation previously reported in Boxers with ARVC.

ANIMALS

Seventy-one Bulldogs fit the inclusion criteria. Genetic analysis was performed on five dogs. Cardiac post-mortem evaluations were performed on two dogs.

METHODS

Medical records from a single veterinary cardiology group (CVCA) were retrospectively evaluated. Tissue and blood samples were submitted for histopathological analysis and genetic testing in select patients.

RESULTS

Presenting complaints included syncope (38%), arrhythmia (81.7%), or murmur (34.2%) documented on examination. On presentation, congestive heart failure (CHF) was diagnosed in 22 (31%) dogs, and 58 (81.7%) had ventricular arrhythmias. On bivariable analyses, the two-dimensional (2D) left atrial-to-aortic root ratio (LA:Ao) was the only prognostic variable significantly associated with survival time. Dogs with 2D LA:Ao below the mean (1.41) had longer median survival to all-cause mortality (12 months; 95% confidence interval [CI] 6.0-15.0 months) than those with 2D LA:Ao above the mean (four months; 95% CI 2.0-6.0 months; p=0.0384). Most dogs (54%) died from cardiac disease, with 42.1% experiencing sudden death. The median time from diagnosis to cardiac death was four months.

CONCLUSIONS

Arrhythmogenic right ventricular cardiomyopathy affects Bulldogs with both arrhythmogenic and dilated-type phenotypes. Despite variable arrhythmia severity and predominantly right-sided involvement in many dogs, an increase in left atrial size was the only significant predictor of mortality in this sample of dogs.

The Longitudinal Outcome Of Canine (K9) myxomatous mitral valve disease (LOOK-Mitral registry): Baseline characteristics

INTRODUCTION

The Longitudinal Outcome Of Canine (K9) myxomatous mitral valve disease (MMVD) registry (LOOK-Mitral registry) was established to describe the natural history and predictors of outcome in dogs affected by MMVD. This study was intended to describe the baseline characteristics of dogs in the LOOK-mitral registry.

ANIMALS

Dogs with echocardiographic evidence of MMVD were prospectively enrolled by thirteen referral centers.

RESULTS

A total of 6102 dogs with MMVD were included. The median age was 10 years (1-19 years), and mixed breed was the most common breed (n = 1,360, 22%). Concomitant diseases were reported in 2459 dogs with chronic respiratory diseases occurring most frequently (14%), followed by the presence of azotemia (6%) and orthopedic diseases (5%). Regarding disease severity, 65% of dogs were in ACVIM Stage-B1, 15% in Stage-B2, and 20% in Stage-C. Dogs in Stage-B1 were younger (p<0.001) than dogs in other stages. Murmur intensity, heart rate during physical examination, and radiographic vertebral heart score were positively associated with the stage. Dogs in Stage-C were more likely to have tachypnea (p<0.001), dyspnea (p<0.001), cough (p<0.001), syncopal episodes (p<0.001), and tachyarrhythmias (p<0.001) compared to dogs in Stage-B1 and B2. Echocardiographic indices of left atrial and ventricular size were positively correlated with the ACVIM stage. Interestingly, 4% of dogs that weighed <20 kg had an increased normalized end-systolic left ventricle internal diameter (>1.26).

CONCLUSIONS

This study contributes to a better understanding of the clinical characteristics of dogs affected by MMVD and provides new findings that may be of clinical relevance.

Predictors of reoccurrence of congestive signs within 180 days after successful treatment of the first episode of congestive heart failure in dogs with myxomatous mitral valve disease

INTRODUCTION

Myxomatous mitral valve disease (MMVD) is the most common cause of left-sided congestive heart failure in dogs. We sought to identify predictors of first reoccurrence of congestive signs (CS) within 180 days in dogs with MMVD and clinically stable heart failure.

ANIMALS

A total of 445 dogs affected by stable American College of Veterinary Internal Medicine (ACVIM)-Stage-C MMVD were included, 106 in the reoccurrence group (RG) and 339 in no reoccurrence group (NRG). Patients were considered "stable" if medical treatment had been unchanged for at least 4 weeks since the first identification of CS.

METHODS

Medical records of dogs with stable ACVIM-Stage-C MMVD included in a registry of dogs affected by MMVD were reviewed. Follow-up was required for inclusion in this investigation. Logistic regression was used to identify clinical and echocardiographic variables that independently predict first reoccurrence of CS.

RESULTS

Baseline left atrial-aortic ratio (p=0.022, OR: 1.89, 90% CI: 1.20-2.98), left ventricular internal diameter at end-diastole (LVIDd_N) (p=0.014, OR: 2.84, 90% CI: 1.41-5.77), peak velocity of early diastolic transmitral flow (p=0.049, OR: 1.81, 90% CI: 1.10-3.00) and furosemide daily dosage (p=0.039, OR: 1.19, 90% CI: 1.04-1.37) were associated with reoccurrence of CS in univariable analyses. The LVIDd_N (p=0.014) remained significant in the multivariable analysis, but the area under the receiver operator characteristic curve was 0.57.

CONCLUSION

This study failed to identify accurate predictors of reoccurrence of CS. However, dogs with larger value of LVIDd_N are more likely to have reoccurrence of CS within 180 days.

Association of APOE polymorphisms and stressful life events with dementia in a Pakistani population

Dementia is a major public health problem worldwide. Alzheimer's disease (AD) is a major form of dementia and the APOE 4 allele is an established genetic risk factor for AD. Similarly, stressful life events are also associated with dementia. The objective of this study was to examine the association of APOE 4 and stressful life events with dementia in a Pakistani sample, which to our knowledge has not been reported previously. We also tested for an interaction between stressful life events and APOE 4 on dementia risk. A total of 176 subjects (61 cases and 115 controls) were recruited. All cases and healthy controls were interviewed to assess cognition, co-morbidities, history of stressful life events and demographics. Blood genotyping for the APOE polymorphism (E2/E3/E4) was performed. APOE 4 and stressful life events were each independently and significantly associated with the risk of dementia (APOE 4: P=0.00697; stressful life events: P=5.29E-09). However, we did not find a significant interaction between APOE 4 carrier status and stressful life events on risk of dementia (P=0.677). Although the sample size of this study was small, the established association of APOE 4 with dementia was confirmed the first time in a Pakistani sample. Furthermore, stressful life events were also found to be significantly associated with dementia in this population.

Low‐dose radiotherapy (LD‐RT) and the modulation of iNOS expression in adjuvant‐induced arthritis in rats

PURPOSE

Low-dose radiotherapy (LD-RT) of arthritic joints applied during the peak of the acute inflammatory response improves the clinical and histomorphological development of adjuvant arthritis. The study was undertaken to investigate the cellular composition of the inflammatory infiltrate and the expression of the pro-inflammatory and anti-inflammatory enzymes, inducible nitric oxide synthase (iNOS), cyclo-oxygenase 2 (COX-2) and haem-oxygenase 1 (HO-1), in response to LD-RT.

MATERIALS AND METHODS

Adjuvant arthritis in female Lewis rats was induced by intradermal injection of heat-inactivated mycobacterium tuberculosis on day 0. Both arthritic hind paws were sham irradiated (group 1) or X-irradiated with either 5 x 1.0 Gy (group 2) or 5 x 0.5 Gy (group 3) from days 15 to 19 after induction (15 animals/group). On days 21 (n=12 joints/group) and 30 (n=18 joints/group), cryostat sections were analysed histologically and immunohistologically after specific staining for macrophages, iNOS, COX-2 and HO-1.

RESULTS

A total of 5 x 1.0 Gy or 5 x 0.5 Gy led to a significant reduction of clinical symptoms from days 21 to 29, and a highly significant reduction of cartilage and bone destruction on day 30. Macrophage-positive areas could be detected continuously throughout the periarticular infiltrate, and were slightly reduced after LD-RT on days 21 and 30. This reduction was more pronounced after 5 x 1.0 Gy. Following LD-RT, the iNOS score was reduced by about 45-50% on days 21 (p<0.05) and 30 (p<0.001). In contrast, the HO-1 score was increased by about 50% on days 21 (p=0.08) and 30 (p=0.03).

CONCLUSIONS

The clinically and histologically observed prevention of the progression of adjuvant arthritis after LD-RT given during the peak of the acute inflammatory response and the reduction of cartilage and bone destruction in the chronic phase appears to be related to the modulation of iNOS activity by low X-ray doses.

Adolescents anticipated experience of screening for genital herpes

Screening asymptomatic adolescents for genital herpes will require sensitivity to adolescents' developmental needs. Twenty-four adolescents (age range 1619 years) were interviewed to explore their perceptions of screening. In general, adolescents thought screening for genital herpes would be viewed as taking care of themselves, although there were concerns that their peers might view getting screened as implying that the adolescent was infected or sexually promiscuous. Most adolescents expected their parents to respond positively, but typically thought that younger adolescents should obtain parental consent for screening, and that adolescents should inform their parents of positive test results. Adolescents wanted to be screened in settings that provided confidentiality and by non-judgemental care providers, but they differed on the setting which they believed would accomplish this. Some recommended mass screening (for example, screening all of those in a certain year at school), presumably as a way to reduce embarrassment and/or stigma. Screening programmes that are adolescent-friendly and accessible, and address adolescents' specific concerns regarding managing the information, can be created.

A simulated reality scenario compared with the computerized Wisconsin card sorting test: an analysis of preliminary results

Neuropsychologists and other clinicians often comment on the minimal relationship that frequently exists between formal assessments of executive functions, analysis of findings, recommendations, and the person's real-life functioning. The authors' believe that current assessments of executive functions do not transfer easily to real-world behavior. There are limitations in the current examinations and in the settings in which they are given. The tests are artificial and the test settings lack the usual stresses, distractions, and multiple demands common to real life. The interactions are unlike what they experience in everyday life. The examiner often, but unintentionally orients the participant to relevant information that in turn can help the person compensate for the difficulties with executive control processes and bias the findings. We believe that virtual reality (VR) more closely approximates real life settings, the distractions, and the common interchanges (VR) provides a "life-like," three-dimensional (3-D) highly interactive environment, and safety from potential dangers that could arise in actual situations. VR can increase motivation because of its gaming, interactive, and immersive qualities and features are easily modified and allow for multiple applications. Our goal is to develop VR assessments that can be administered under controlled and safe conditions, but which are more sensitive to difficulties with executive control processes critical to safe, independent living. This initial study compares several functions assessed by the Wisconsin Card Sorting Test (WCST) with our three-dimensional, stereographic scenario, Look for a Match (LFAM) Study participants completed questionnaires, alternately began with either the WCST or LFAM, and then took the second test. All participants completed motion sickness and follow-up questionnaires. The results demonstrated that the study participants found LFAM to be more enjoyable and interesting, but found the WCST to be easier. While there is an effect of order with participants doing relatively better on the assessment tool administered second, overall the LFAM performance was inferior to that on the WCST. However, even considering the order effect, LFAM seemed to be more difficult than the WCST.

To make a difference: the founding of the Crohn's and Colitis Foundation of America

In 1965, with the help of Dr. Henry D. Janowitz, Irwin M. Rosenthal established the Foundation for Research in Ileitis, Inc., now known as the Crohn's and Colitis Foundation of America, Inc. He was joined shortly thereafter by William D. Modell. At that time, the entire annual NIH budget for research on inflammatory bowel disease was only $25,000. Successful fund raising made it possible to recruit a research fellow at The Mount Sinai Hospital in the Division of Gastroenterology to study ileitis. Thereafter, the efforts of the foundation expanded nationwide. It supported a nationally coordinated research program and sponsored education for physicians, patients and the public. In addition, it established support groups to help patients and their families cope with Crohn's disease and ulcerative colitis. With the energy and philanthropy of the foundation's many lay leaders, tens of millions of dollars have been raised for research and education in inflammatory bowel disease.

Stigmatization and the development of friendship and romantic relationships in adolescent victims of sexual abuse

This study examines same- and other-sex friendship networks and perceptions of peer competence as functions of stigmatization, defined as shame and a self-blame attributional style. Fifty-six sexually abused adolescents were seen at the time of abuse discovery and 1 year later. Higher self-blame attributional style for the abuse was related to more satisfaction with other-sex friends and less satisfaction with same-sex friends. More shame was related to less satisfaction with same-sex friends and to having a larger number of other-sex friends. Higher self-blame attributional style was related to perceptions of poorer peer acceptance and close friendship and to perceptions of poorer romantic appeal. More shame was related to lower perceptions of peer acceptance and close friendship. The results support the idea that abuse victims who experience higher levels of shame and self-blame attributional style feel less capable of forming satisfying relationships with peers, friends, and potential romantic partners.

The use of oral contraceptive pharmaceutical sample packs by adolescent health care providers

STUDY OBJECTIVE

The purpose of this study was to understand how health care providers use and distribute oral contraceptive pill (OCP) sample packs to adolescents.

DESIGN

Qualitative study involving face-to-face structured interviews.

SETTING

Interviews lasted approximately 20-30 minutes and were done in the health care provider's office setting.

PARTICIPANTS

A convenience sample of fourteen health care providers (pediatricians, family practitioners, nurse practitioners, and midwives) who have practices that include adolescents were interviewed.

MAIN OUTCOME MEASURES

Interviews were audio-recorded and transcribed. Two independent reviewers read the transcripts for themes. Transcripts were then coded and frequency counts were done.

CONCLUSIONS

OCP sample packs are an important tool for education and compliance. The pharmaceutical OCP sample supply may influence the health care provider's OCP choice for a teen.

Longitudinal risk of std acquisition in adolescent girls using a generalized estimating equations model

Background: To date, few studies have used a longitudinal approach in examining risk factors for STD acquisition in teenage girls. In the present study, we examined risk of STD acquisition in adolescent girls over a three-year period using longitudinal analyses.Methods: One hundred and seventy-four girls between the ages of 12 and 16 (mean age = 14.5) participated in a longitudinal study of adolescent romantic relationships. The racial composition of the subject pool was 80% African-American and 20% Caucasian. These girls were followed for three years at six-month intervals. By the end of the study, 127 of the girls were sexually experienced, and thus, were included in the analyses regarding risk for STDs. The risk for history of STD was evaluated using a generalized estimating equations (GEE) model, which allows for the inclusion of data from subjects with missing visits. The following independent variables were entered into the model: age, race, screening IQ score, qualitative cognitive functioning, perceptions of STD prevalence among female friends, and whether a condom was used at last intercourse. Additional independent variables included number of lifetime partners (4 or more lifetime partners, 2 to 3 lifetime partners, only one partner) and age of sexual debut (less than 14 years, 14-16 years, and 17 years and older), five factors from the Family Environment Scale, and three types of parental monitoring (direct, direct when with peers, and indirect).Results: The results of the longitudinal (GEE) model indicated that having a history of an STD was significantly related to a younger age of sexual debut (p <.01), having more partners (p <.0001), being African-American (p =. 01), and having a lower screening IQ score (p <.01).Conclusions: These results suggest that risk of STD is associated with both modifiable and non-modifiable variables. Race and intellectual functioning independently contributed to STD risk, stressing the importance of utilizing prevention programs that are culturally and developmentally specific. For example, less intelligent girls may need to have information presented in a more concrete manner, with a focus on the present rather than the future. The targets of these prevention programs should continue to emphasize delaying initiation, as well as partner selection. Finally, the fact that variables for STD acquisition in this longitudinal model are comparable to previous cross-sectional studies of STD acquisition suggests that these are potent predictors of risk.

Attachment over time

Continuity in attachment classification from infancy to late adolescence was examined and related to autobiographical memories of childhood, divorce, and maladjustment. Eighty-four White middle-class children (48 girls) were seen in a modified Strange Situation at 12 months and given the Adult Attachment Interview at 18 years. In addition, data were collected on 13-year-olds' childhood recollections as well as adolescent, mother, and teacher ratings of maladjustment at 13 and 18 years of age. Divorce status of parents also was obtained. Results indicated no continuity in attachment classification from 1 to 18 years of age and no relation between infant attachment status and adolescent maladjustment. Divorce was related to 13-year-olds' childhood recollections as well as to insecure attachment status at 18 years. Eighteen-year-olds with insecure attachment classification were more likely to rate themselves as maladjusted. The results support the idea of attachment as an evolving representation dependent upon the nature of the family environment as indexed by divorce.

Estimating the prevalence of chronic fatigue syndrome among nurses

The present study assessed the prevalence of chronic fatigue syndrome (CFS) in a sample of nurses. There is a paucity of studies on the prevalence of CFS in healthcare professionals. Two samples of nurses were recruited through mailed questionnaires. Data were collected on demographic characteristics and symptoms. In addition from the sample, those nurses with CFS-like symptoms were more comprehensively evaluated using a structured clinical interview and reviewing their medical records. A physician review team estimated the prevalence of CFS to be 1,088 per 100,000. These findings suggest that nurses might represent a high-risk group for this illness, possibly due to occupational stressors such as exposure to viruses in the work setting, stressful shift work that is disruptive to biologic rhythms, or to other possible stressors in the work settings (e.g., accidents).

A pencil beam algorithm for proton dose calculations

The sharp lateral penumbra and the rapid fall-off of dose at the end of range of a proton beam are among the major advantages of proton radiation therapy. These beam characteristics depend on the position and characteristics of upstream beam-modifying devices such as apertures and compensating boluses. The extent of separation, if any, between these beam-modifying devices and the patient is particularly critical in this respect. We have developed a pencil beam algorithm for proton dose calculations which takes accurate account of the effects of materials upstream of the patient and of the air gap between them and the patient. The model includes a new approach to picking the locations of the pencil beams so as to more accurately model the penumbra and to more effectively account for the multiple-scattering effects of the media around the point of interest. We also present a faster broad-beam version of the algorithm which gives a reasonably accurate penumbra. Predictions of the algorithm and results from experiments performed in a large-field proton beam are presented. In general the algorithm agrees well with the measurements.

A pencil beam algorithm for proton dose calculations

The sharp lateral penumbra and the rapid fall-off of dose at the end of range of a proton beam are among the major advantages of proton radiation therapy. These beam characteristics depend on the position and characteristics of upstream beam-modifying devices such as apertures and compensating boluses. The extent of separation, if any, between these beam-modifying devices and the patient is particularly critical in this respect. We have developed a pencil beam algorithm for proton dose calculations which takes accurate account of the effects of materials upstream of the patient and of the air gap between them and the patient. The model includes a new approach to picking the locations of the pencil beams so as to more accurately model the penumbra and to more effectively account for the multiple-scattering effects of the media around the point of interest. We also present a faster broad-beam version of the algorithm which gives a reasonably accurate penumbra. Predictions of the algorithm and results from experiments performed in a large-field proton beam are presented. In general the algorithm agrees well with the measurements.

The safety of acellular pertussis vaccine vs whole-cell pertussis vaccine. A postmarketing assessment

OBJECTIVE

To determine the impact of the introduction of acellular pertussis vaccine for the fourth and fifth doses of the diphtheria and tetanus toxoids and pertussis vaccine series in children on rates of reported vaccine-associated adverse events in the United States.

DESIGN

Analysis of postmarketing vaccine adverse event data from the Vaccine Adverse Event Reporting System during the years 1991 to 1993.

POPULATION STUDIED

Approximately 27 million doses of diphtheria and tetanus toxoids and pertussis vaccine and 5 million doses of diphtheria and tetanus toxoids and acellular pertussis vaccine were distributed from 1991 to 1993 to children 15 months to 7 years of age.

MAIN OUTCOME MEASURES

Rates of reported fever, seizures, and hospitalizations after pertussis vaccination.

RESULTS

Rates of reported adverse events per 100,000 vaccinations were significantly lower after administration of diphtheria and tetanus toxoids and acellular pertussis vaccine than diphtheria and tetanus toxoids and pertussis vaccine for the following outcomes: all reports, 2.9 vs 9.8; fever, 1.9 vs 7.5; seizures, 0.5 vs 1.7; and hospitalizations, 0.2 vs 0.9.

CONCLUSIONS

These results confirm that minor adverse events are less frequent after administration of the acellular pertussis vaccine. In addition, these data suggested that seizures and hospitalizations associated with pertussis vaccination are less frequent after administration of the acellular pertussis vaccine in age groups for which it is now recommended.

Management of dyspnea and cough in patients with cancer

The understanding and treatment of dyspnea in the cancer patient are where the science of pain management was 15 or 20 years ago. Very few studies have examined the pathophysiologic mechanisms that cause dyspnea in cancer patients, and few investigators have evaluated therapeutic strategies to control dyspnea in this patient group. The optimal therapy for dyspnea is treatment of the underlying cause. When this is not possible, opioids and phenothiazines provide effective symptomatic relief in most cases, but many unanswered questions remain. Are these the optimal drugs, and what are their optimal doses? What are the effects of chronic dosing? Which is the best route of administration? How serious are the risks of respiratory depression? A clear consensus supports the aggressive treatment of pain in terminally ill cancer patients, even if death is hastened as an unintended consequence. No such position has yet been reached in the management of dyspnea in the same population. As a result, dyspnea is addressed only very late in the course of the disease, perhaps reducing the patient's quality of life and function at earlier stages and resulting in a very small "therapeutic window" in the terminal phase. Clearly, a need exists for more research to determine the most effective management of this common and very distressing symptom.

The reporting sensitivities of two passive surveillance systems for vaccine adverse events

To evaluate reporting sensitivities for vaccine adverse events, reporting rates were estimated by dividing the number of events reported to the Monitoring System for Adverse Events Following Immunization and the Vaccine Adverse Event Reporting System in a given period by the number of doses administered or distributed during the same period. Reporting sensitivity was calculated as the ratio of the rates at which events were reported to each passive surveillance system (numerator) and occurred in controlled studies (denominator). Reporting sensitivities were generally better in the public sector than in the private sector. The significant underreporting of known outcomes, together with the nonspecific nature of most adverse event reports, highlights the limitations of passive surveillance systems in assessing the incidence of vaccine adverse events.

Effects of electrocardiograph frequency filters on P-QRS-T amplitudes of the feline electrocardiogram

OBJECTIVE--To determine whether standard manual frequency filters in the ON and OFF settings affected P-QRS-T voltages, discover whether recorded P-QRS-T voltages vary between commercial electrocardiographs, assess effects of frequency filters on base-line artifact, and evaluate ECG frequency content by high-fidelity recordings subjected to digital filters with variable frequencies. DESIGN--Sequential 10-lead ECG were recorded in 30 cats, using 3 commercial electrocardiographs to assess effects of manual frequency filters on the P-QRS-T wave forms. Three clinically normal cats were evaluated for ECG frequency content. ANIMALS--Thirty cats (13 with hypertrophic cardiomyopathy; 4 with restrictive cardiomyopathy; 3 hyperthyroid; 1 with ventricular septal defect; 1 with aortic stenosis; and 8 with no detectable cardiovascular disease). Three additional clinically normal cats were studied for effects of frequency filters on the ECG frequency content. PROCEDURES--Ten-lead ECG were recorded on each cat by use of 3 commercial electrocardiographs sequentially. For each machine, a recording was made with manual filters ON, immediately followed by a recording with manual filters OFF. High-fidelity lead-II ECG recordings were made with filters set with their rolloff frequency at 0.1 Hz and 3.0 kHz; output voltage (0.2 mV/V) was fed to an analog-to-digital converter, then to attendant software, which sampled the signal at 6 kHz with a 12-bit sampler, and were digitally filtered at various corner frequencies. RESULTS--Voltages recorded by all 3 electrocardiographs were greatest when filters were OFF (most prominent on R- and S-wave voltages). In all recorded leads, R-wave voltage was significantly greater when filters were OFF than ON. Comparison of voltages indicated significant (P < 0.05) differences between R-wave voltages recorded in all leads with manual filters ON, but not with filters OFF. With filters ON, each electrocardiograph produced a smaller percentage of recordings with moderate to severe baseline artifact than with filters OFF. R-Wave amplitudes of high-fidelity lead-II ECG were significantly decreased with digital filters set at corner frequencies < 150 Hz. CONCLUSIONS--Significant (P < 0.05) voltage attenuation was recorded by each of the 3 commercial electrocardiographs when frequency filters were ON, compared with OFF. Comparison of waveform voltages among electrocardiographs with filters ON indicated significant variation in R-wave amplitudes in all leads. With manual filters ON, each electrocardiograph recorded a smaller percentage of recordings with baseline artifact than with filters OFF. Substantial frequency components > or = 150 Hz are present in the feline ECG waveform. Thus, filters with frequencies < 150 Hz markedly attenuate the feline R wave. CLINICAL RELEVANCE--Attenuation of feline ECG signals occurs with use of commercial electrocardiographs and varies greatly between manufacturers. This is attributable largely to internal manual frequency filters. These consequences may be important when applying standard feline reference values or when equivocal voltage measurements are recorded.

Pertussis infection among adults during the 1993 outbreak in Chicago

To evaluate the role of adults in the transmission of pertussis during an epidemic, persons presenting with unexplained cough to ambulatory care clinics were evaluated for evidence of pertussis infection. Nasopharyngeal specimens for culture and serum samples for IgG and IgA antibodies to filamentous hemagglutinin and pertussis toxin antigens of Bordetella pertussis were obtained. Thirty-eight adults were enrolled in the study; 10 (26%) had serologic evidence of B. pertussis infection. Clinical findings were not significantly different among persons with and without evidence of pertussis infection. Pertussis should be considered in the differential diagnosis of persistent cough in all age groups. Future use of new acellular pertussis vaccines in adults may substantially impact the control of the infection.

Adjuvant chemotherapy does not affect employment in patients with early-stage breast cancer

OBJECTIVE

To assess the impact of adjuvant chemotherapy for the management of breast cancer on subsequent patient employment.

DESIGN

Retrospective cohort study.

SETTING

University-affiliated community hospital cancer center.

PATIENTS

Patients who were 18 to 65 years old and were diagnosed as having breast cancer stages 0, I, II, and IIIa between January 1986 and January 1991 were contacted and asked whether they had been employed at the time of the diagnosis. The 145 patients who had breast cancer and who had been working at the time of diagnosis completed a questionnaire, which included questions regarding demographic characteristics, employment history, and the reasons for any period of unemployment. The 76 patients who had received adjuvant chemotherapy were compared with the 69 who had not.

MEASUREMENTS AND RESULTS

The main endpoint was return to work by one, three, six, and 12 months after surgery. Of the 76 patients who had received chemotherapy, 70 (92%) had resumed work by 12 months after treatment began. Of the 69 who had not been treated with chemotherapy, 65 (94%) had resumed work in 12 months. The proportions of patients who had returned to work by one, three, and six months were similar in the two groups. Regression analyses demonstrated no significant confounding or interaction of adjuvant treatment with age, menopausal status, marital status, years of education, or type of job in regard to return to work.

CONCLUSIONS

Adjuvant chemotherapy does not delay or prevent return to work in women treated for early-stage breast cancer.

Supervised interpretation of echocardiograms with a psychological model of expert supervision

We have developed a collaborative scheme that facilitates active human supervision of the binary segmentation of an echocardiogram. The scheme complements the reliability of a human expert with the precision of segmentation algorithms. In the developed system, an expert user compares the computer generated segmentation with the original image in a user friendly graphics environment, and interactively indicates the incorrectly classified regions either by pointing or by circling. The precise boundaries of the indicated regions are computed by studying original image properties at that region, and a human visual attention distribution map obtained from the published psychological and psychophysical research. We use the developed system to extract contours of heart chambers from a sequence of two dimensional echocardiograms. We are currently extending this method to incorporate a richer set of inputs from the human supervisor, to facilitate multi-classification of image regions depending on their functionality. We are integrating into our system the knowledge related constraints that cardiologists use, to improve the capabilities of our existing system. This extension involves developing a psychological model of expert reasoning, functional and relational models of typical views in echocardiograms, and corresponding interface modifications to map the suggested actions to image processing algorithms.

Progress report on multicenter study of laser-assisted liposuction

Fifty-one patients underwent an FDA-approved study of laser-assisted liposuction in five plastic surgery centers. The YAG laser fiber is contained within the cannula and shears off the fat cleanly and coagulates blood vessels as the fat is drawn into the cannula. The drop in hemoglobin was relatively modest after surgery. Patients were able to return to work at six days and to light exercise at seven days. Contralateral studies showed a slight benefit for the laser side at both one and eight weeks for ecchymosis, pain/discomfort, and edema. Lipocrit studies were inconsistent.

Zygomycosis and HIV infection

The severe immunosuppression associated with HIV infection increases susceptibility to opportunistic fungi. We describe a primary gangrenous cutaneous infection caused by Rhizopus arrhizus in an HIV-infected intravenous narcotic user. In addition, we review nine reported cases of zygomycosis in HIV-infected patients and discuss the frequency and outcome of zygomycosis in HIV infection. Eight of 10 patients were intravenous drug users. Cutaneous infection occurred in four patients. Another case was associated with drug-induced neutropenia. With treatment, 60% of the patients recovered. HIV-induced immunosuppression rarely predisposes to zygomycosis except in intravenous drug users or persons with other risk factors for this fungal infection.

Gastrointestinal obstruction due to Mycobacterium avium intracellulare associated with the acquired immunodeficiency syndrome

Three patients with the acquired immunodeficiency syndrome (AIDS) had complete or incomplete gastrointestinal obstruction resulting from infection with Mycobacterium avium intracellulare. The pathophysiologic mechanisms of the obstruction in the three cases were ileal volvulus due to adhesions from matted infected mesenteric lymph nodes, ileal intussusception due to engorged infected ileal mucosa, and small bowel displacement and compression by massively enlarged infected intraabdominal lymph nodes. These reports extend the clinical manifestations of Mycobacterium avium intracellulare infection in patients with AIDS to include partial and complete gastrointestinal obstruction.