Physical Resilience as a Predictor of Lifespan and Late-Life Health in Genetically Heterogeneous Mice

Dynamic measures of resilience-the ability to resist and recover from a challenge-may be informative of the rate of aging before overt manifestations such as chronic disease, disability, and frailty. From this perspective mid-life resilience may predict longevity and late-life health. To test this hypothesis, we developed simple, reproducible, clinically relevant challenges, and outcome measures of physical resilience that revealed differences between and within age groups of genetically heterogeneous mice, and then examined associations between mid-life resilience and both lifespan and late-life measures of physiological function. We demonstrate that time to recovery from isoflurane anesthesia and weight change following a regimen of chemotherapy significantly differed among young, middle-aged, and older mice, and were more variable in older mice. Females that recovered faster than the median time from anesthesia (more resilient) at 12 months of age lived 8% longer than their counterparts, while more resilient males in mid-life exhibited better cardiac (fractional shortening and left ventricular volumes) and metabolic (glucose tolerance) function at 24 months of age. Moreover, female mice with less than the median weight loss at Day 3 of the cisplatin challenge lived 8% longer than those that lost more weight. In contrast, females who had more weight loss between Days 15 and 20 were relatively protected against early death. These data suggest that measures of physical resilience in mid-life may provide information about individual differences in aging, lifespan, and key parameters of late-life health.

A spatial sequencing atlas of age-induced changes in the lung during influenza infection

Influenza virus infection causes increased morbidity and mortality in the elderly. Aging impairs the immune response to influenza, both intrinsically and because of altered interactions with endothelial and pulmonary epithelial cells. To characterize these changes, we performed single-cell RNA sequencing (scRNA-seq), spatial transcriptomics, and bulk RNA sequencing (bulk RNA-seq) on lung tissue from young and aged female mice at days 0, 3, and 9 post-influenza infection. Our analyses identified dozens of key genes differentially expressed in kinetic, age-dependent, and cell type-specific manners. Aged immune cells exhibited altered inflammatory, memory, and chemotactic profiles. Aged endothelial cells demonstrated characteristics of reduced vascular wound healing and a prothrombotic state. Spatial transcriptomics identified novel profibrotic and antifibrotic markers expressed by epithelial and non-epithelial cells, highlighting the complex networks that promote fibrosis in aged lungs. Bulk RNA-seq generated a timeline of global transcriptional activity, showing increased expression of genes involved in inflammation and coagulation in aged lungs. Our work provides an atlas of high-throughput sequencing methodologies that can be used to investigate age-related changes in the response to influenza virus, identify novel cell-cell interactions for further study, and ultimately uncover potential therapeutic targets to improve health outcomes in the elderly following influenza infection.

Autoreactive CD8 T cells in NOD mice exhibit phenotypic heterogeneity but restricted TCR gene usage

Paired scRNA-seq and scTCR-seq reveals that diabetogenic CD8 T cells in the islets and spleens of NOD mice exhibit phenotypic and clonal heterogeneity despite restricted TCR gene usage. Expression of certain TCR genes correlates with clonal proliferation and effector phenotype.

Type 1 diabetes (T1D) is an autoimmune disorder defined by CD8 T cell–mediated destruction of pancreatic β cells. We have previously shown that diabetogenic CD8 T cells in the islets of non-obese diabetic mice are phenotypically heterogeneous, but clonal heterogeneity remains relatively unexplored. Here, we use paired single-cell RNA and T-cell receptor sequencing (scRNA-seq and scTCR-seq) to characterize autoreactive CD8 T cells from the islets and spleens of non-obese diabetic mice. scTCR-seq demonstrates that CD8 T cells targeting the immunodominant β-cell epitope IGRP_206-214 exhibit restricted TCR gene usage. scRNA-seq identifies six clusters of autoreactive CD8 T cells in the islets and six in the spleen, including memory and exhausted cells. Clonal overlap between IGRP_206-214–reactive CD8 T cells in the islets and spleen suggests these cells may circulate between the islets and periphery. Finally, we identify correlations between TCR genes and T-cell clonal expansion and effector fate. Collectively, our work demonstrates that IGRP_206-214–specific CD8 T cells are phenotypically heterogeneous but clonally restricted, raising the possibility of selectively targeting these TCR structures for therapeutic benefit.

Suppressive neutrophils require PIM1 for metabolic fitness and survival during chronic viral infection

The immune response to a chronic viral infection is uniquely tailored to balance viral control and immunopathology. The role of myeloid cells in shaping the response to chronic viral infection, however, is poorly understood. We perform single-cell RNA sequencing of myeloid cells during acute and chronic lymphocytic choriomeningitis virus (LCMV) infection to address this question. Our analysis identifies a cluster of suppressive neutrophils that is enriched in chronic infection. Furthermore, suppressive neutrophils highly express the gene encoding Proviral integration site for Moloney murine leukemia virus-1 (PIM1), a kinase known to promote mitochondrial fitness and cell survival. Pharmacological inhibition of PIM1 selectively diminishes suppressive neutrophil-mediated immunosuppression without affecting the function of monocytic myeloid-derived suppressor cells (M-MDSCs). Decreased accumulation of suppressive neutrophils leads to increased CD8 T cell function and viral control. Mechanistically, PIM kinase activity is required for maintaining fused mitochondrial networks in suppressive neutrophils, but not in M-MDSCs, and loss of PIM kinase function causes increased suppressive neutrophil apoptosis.

The senescence-associated secretome as an indicator of age and medical risk

Produced by senescent cells, the senescence-associated secretory phenotype (SASP) is a potential driver of age-related dysfunction. We tested whether circulating concentrations of SASP proteins reflect age and medical risk in humans. We first screened senescent endothelial cells, fibroblasts, preadipocytes, epithelial cells, and myoblasts to identify candidates for human profiling. We then tested associations between circulating SASP proteins and clinical data from individuals throughout the life span and older adults undergoing surgery for prevalent but distinct age-related diseases. A community-based sample of people aged 20-90 years (retrospective cross-sectional) was studied to test associations between circulating SASP factors and chronological age. A subset of this cohort aged 60-90 years and separate cohorts of older adults undergoing surgery for severe aortic stenosis (prospective longitudinal) or ovarian cancer (prospective case-control) were studied to assess relationships between circulating concentrations of SASP proteins and biological age (determined by the accumulation of age-related health deficits) and/or postsurgical outcomes. We showed that SASP proteins were positively associated with age, frailty, and adverse postsurgery outcomes. A panel of 7 SASP factors composed of growth differentiation factor 15 (GDF15), TNF receptor superfamily member 6 (FAS), osteopontin (OPN), TNF receptor 1 (TNFR1), ACTIVIN A, chemokine (C-C motif) ligand 3 (CCL3), and IL-15 predicted adverse events markedly better than a single SASP protein or age. Our findings suggest that the circulating SASP may serve as a clinically useful candidate biomarker of age-related health and a powerful tool for interventional human studies.

Late-life time-restricted feeding and exercise differentially alter healthspan in obesity

Aging and obesity increase multimorbidity and disability risk, and determining interventions for reversing healthspan decline is a critical public health priority. Exercise and time‐restricted feeding (TRF) benefit multiple health parameters when initiated in early life, but their efficacy and safety when initiated at older ages are uncertain. Here, we tested the effects of exercise versus TRF in diet‐induced obese, aged mice from 20 to 24 months of age. We characterized healthspan across key domains: body composition, physical, metabolic, and cardiovascular function, activity of daily living (ADL) behavior, and pathology. We demonstrate that both exercise and TRF improved aspects of body composition. Exercise uniquely benefited physical function, and TRF uniquely benefited metabolism, ADL behavior, and circulating indicators of liver pathology. No adverse outcomes were observed in exercised mice, but in contrast, lean mass and cardiovascular maladaptations were observed following TRF. Through a composite index of benefits and risks, we conclude the net healthspan benefits afforded by exercise are more favorable than those of TRF. Extrapolating to obese older adults, exercise is a safe and effective option for healthspan improvement, but additional comprehensive studies are warranted before recommending TRF.

Corticohippocampal Dysfunction In The OBiden Mouse Model Of Primary Oligodendrogliopathy

Despite concerted efforts over decades, the etiology of multiple sclerosis (MS) remains unclear. Autoimmunity, environmental-challenges, molecular mimicry and viral hypotheses have proven equivocal because early-stage disease is typically presymptomatic. Indeed, most animal models of MS also lack defined etiologies. We have developed a novel adult-onset oligodendrogliopathy using a delineated metabolic stress etiology in myelinating cells, and our central question is, “how much of the pathobiology of MS can be recapitulated in this model?” The analyses described herein demonstrate that innate immune activation, glial scarring, cortical and hippocampal damage with accompanying electrophysiological, behavioral and memory deficits naturally emerge from disease progression. Molecular analyses reveal neurofilament changes in normal-appearing gray matter that parallel those in cortical samples from MS patients with progressive disease. Finally, axon initial segments of deep layer pyramidal neurons are perturbed in entorhinal/frontal cortex and hippocampus from OBiden mice, and computational modeling provides insight into vulnerabilities of action potential generation during demyelination and early remyelination. We integrate these findings into a working model of corticohippocampal circuit dysfunction to predict how myelin damage might eventually lead to cognitive decline.

Abstract 4318: Mycoplasma arginini infection shifts the energy catabolism ratio of metastatic macrophages towards fermentation and is associated with an increase in primary tumor size, metastasis and malignancy

Mycoplasma are the smallest self-replicating prokaryotes and are burdened by their notoriety. It is widely unknown that mycoplasma are readily detected in many primary human cancer tissues and can influence tumorigenesis. Some mycoplasma species such as M. fermentans and M. hyorhinis can transform normal murine and human cell lines into tumorigenic cells. Mycoplasma infection can inactivate tumor suppressor genes and activate oncogenes. These observations suggest that mycoplasma can be both carcinogenic and or onco-modulators. We found that M. arginini was present in the metastatic macrophage cell line VM-M3 (referred to as M3myco+). Antibiotic was used to eradicate M. arginini (verified by mycoplasmal 16S rDNA PCR amplification) from the M3 cells (M3myco- cells). Oxygen consumption rate was higher in the than the M3myco- cells than in the M3myco+ cells, whereas lactate production was similar in both the M3myco+ and M3myco- cells. Glucose suppressed oxygen consumption in both cell lines indicating a Crabtree effect. The in-vitro proliferation rate was similar in both cell lines when seeded at low density, but was higher in the M3myco+ cells than in the M3myco- cells at higher cell densities. Tumor size at the primary inoculation site in flank was notably smaller and systemic metastasis in the syngeneic inbred VM mouse host was qualitatively less for the M3myco- cells than for the M3myco + cells, respectively. Survival was also longer in VM mice inoculated with the M3myco- cells compared to the M3myco+ cells. Our data indicate that M. arginini is an onco-modulator that might influence tumor growth through an effect tumor cell energy metabolism. (Supported by Boston College Research Expense fund).

Citation Format: Roberto Flores, Ashley K. Brown, Zeynep Akgoc, Thomas N. Seyfried. Mycoplasma arginini infection shifts the energy catabolism ratio of metastatic macrophages towards fermentation and is associated with an increase in primary tumor size, metastasis and malignancy. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 4318. doi:10.1158/1538-7445.AM2014-4318

The effect of group-based exercise on cognitive performance and mood in seniors residing in intermediate care and self-care retirement facilities: a randomised controlled trial

OBJECTIVE

To determine the effect of a general group-based exercise programme on cognitive performance and mood among seniors without dementia living in retirement villages.

DESIGN

Randomised controlled trial.

SETTING

Four intermediate care and four self-care retirement village sites in Sydney, Australia.

PARTICIPANTS

154 seniors (19 men, 135 women; age range 62 to 95 years), who were residents of intermediate care and self-care retirement facilities.

INTERVENTION

Participants were randomised to one of three experimental groups: (1) a general group-based exercise (GE) programme composed of resistance training and balance training exercises; (2) a flexibility exercise and relaxation technique (FR) programme; or (3) no-exercise control (NEC). The intervention groups (GE and FR) participated in 1-hour exercise classes twice a week for a total period of 6 months.

MAIN OUTCOME MEASURES

Using standard neuropsychological tests, we assessed cognitive performance at baseline and at 6-month re-test in three domains: (1) fluid intelligence; (2) visual, verbal and working memory; and (3) executive functioning. We also assessed mood using the Geriatric Depression Scale (GDS) and the Positive and Negative Affect Schedule (PANAS).

RESULTS

The GE programme significantly improved cognitive performance of fluid intelligence compared with FR or NEC. There were also significant improvements in the positive PANAS scale within both the GE and FR groups and an indication that the two exercise programmes reduced depression in those with initially high GDS scores.

CONCLUSIONS

Our GE programme significantly improved cognitive performance of fluid intelligence in seniors residing in retirement villages compared with our FR programme and the NEC group. Furthermore, both group-based exercise programmes were beneficial for certain aspects of mood within the 6-month intervention period.

Abnormal T cell differentiation persists in patients with rheumatoid arthritis in clinical remission and predicts relapse

OBJECTIVES

An abnormal CD4+ T cell subset related to inflammation exposure (inflammation-related cells, IRC) has been identified in rheumatoid arthritis (RA). Patients with inflammatory and non-inflammatory diseases were used to examine the relationship between inflammation and this T cell subset in vivo.

METHODS

Blood was collected from healthy controls and patients with RA (active disease or in clinical remission), Crohn's disease and osteoarthritis. IRC and chemokine receptors were quantified by flow cytometry. Thymic activity and apoptotic factors were measured by real-time polymerase chain reaction. Circulating cytokines were measured by enzyme-linked immunosorbent assay. CXCR4 and SDF1 in synovial biopsies were measured using immunohistochemistry.

RESULTS

IRC were identified in patients with RA (p<0.0001) and Crohn's disease (p = 0.005), but not in those with osteoarthritis. In RA in remission, IRC persisted (p<0.001). In remission, hyperproliferation of IRC was lost, chemokine receptor expression was significantly lowered (p<0.007), Bax expression dropped significantly (p<0.001) and was inversely correlated with IRC (rho = -0.755, p = 0.03). High IRC frequency in remission was associated with relapse within 18 months (OR = 6.4, p<0.001) and a regression model predicted 72% of relapse.

CONCLUSIONS

These results suggest a model in which, despite the lack of systemic inflammation, IRC persist in remission, indicating that IRC are an acquired feature of RA. They have, however, lost their hyper-responsiveness, acquired a potential for survival, and no longer express chemokine receptors. IRC persistence in remission confirms their important role in chronic inflammation as circulating precursors of pathogenic cells. This was further demonstrated by much higher incidence of relapse in patients with high IRC frequency in remission.

Lower uterine segment involvement as a predictor for lymph node spread in endometrial carcinoma

OBJECTIVES

Several predictive factors for lymph node spread in endometrial cancer have been identified including tumor grade, depth of invasion, lymphatic or vascular-space invasion, and histologic subtype. Lower uterine segment involvement may also be predictive of lymph node spread. The objective of this study was to investigate the relationship between lower uterine segment involvement in endometrial carcinoma and lymph node spread.

METHODS

This was an IRB approved retrospective study. Data were collected for all patients diagnosed with endometrial cancer from June 1999 to December 2004. The primary end point was the presence of nodal involvement. Subset analysis was performed by histologic subtype. Univariate and multivariate nominal logistic regression was performed. Categorical variables were compared using Chi-square and Fischer's Exact Test.

RESULTS

Two-hundred and ninety-nine subjects were eligible for review. One-hundred seventy four (58%) had lower uterine segment involvement. Forty-four (25%) of those with lower uterine segment involvement had positive nodes compared to 10 (8%) of those without (p=0.0001). On univariate analysis, lower uterine segment involvement, lymphovascular-space invasion, and deep invasion predicted nodal disease. On multivariate analysis, lower uterine segment remained predictive of nodal spread for the endometrioid subset. For high-risk histologies, only lymphovascular-space invasion and deep myometrial invasion were predictive of nodal spread.

CONCLUSIONS

Lower uterine segment involvement in endometrial carcinoma is an important predictor of lymph node involvement for patients with endometrioid histologies. Tumor within the lower uterine segment may be an important factor to consider in intraoperative decision making regarding staging.

The development of an evidence-based educational framework to facilitate the training of competent rheumatologist ultrasonographers

OBJECTIVES

Musculoskeletal ultrasonography (MSKUS) has been described by some rheumatologists as the 'stethoscope of the joint'. Such enthusiasm is supported by evidence confirming validity and clinical utility in evaluation of musculoskeletal diseases. But if rheumatologist-performed MSKUS is to emulate the impact of cardiologist-performed echocardiography, a number of educational challenges need be addressed. Evaluation of current training reveals the absence of a unified educational structure, ad hoc teaching and assessment and published data are insufficient to make practice and training recommendations specific to rheumatology.

METHODS

Informed by developments in adult-learning theory, we have utilized a competency-based approach to develop an educational programme for rheumatologist ultrasonographers. Fundamental to this process has been accurate functional analysis of the role of the rheumatologist ultrasonographer and precise translation of these data into educational outcomes. This involved a thorough, transparent, iterative, curriculum-defining approach, employing quantitative and qualitative research techniques including interview, questionnaire, Delphi and standard setting methodologies. All relevant stakeholders were engaged, including international US experts and clinical rheumatologists.

RESULTS

Outcomes include clarification of the role of a rheumatologist ultrasonographer; definition of appropriate knowledge and skills; establishment of competency standards; a balanced, clearly defined, clinically relevant educational outcome blueprint. Teaching and assessment approaches have been piloted as part of an accessible modular curriculum strategy. Thorough validation and evaluation confirms effectiveness, efficiency and suitability.

CONCLUSIONS

A comprehensive evidence-based, expert consensus-defined educational framework is proposed that provides a template for teaching and learning and standards for competency assessment. This should facilitate common principles of training, uniform professional practice and a justifiable governance structure.

The challenges of integrating ultrasonography into routine rheumatology practice: addressing the needs of clinical rheumatologists

OBJECTIVES

The practice of musculoskeletal ultrasonography (MSKUS) by UK rheumatologists remains limited, despite their reported enthusiasm. This study aimed to investigate factors that may encourage or limit future dissemination of rheumatologist-performed MSKUS and provide insights into perceived clinical importance and learning motivation relating to published recommendations by MSKUS experts.

METHODS

A written questionnaire study was conducted, involving 48 rheumatologists. Questions included the potential role of self-performed MSKUS, skills that they would be willing to learn and factors that may encourage or limit learning and practice. Competency recommendations proposed by imaging experts (142 skills in 7 anatomical areas) were reviewed, and quantitative and qualitative data collected regarding 'value to their practice' and 'learning motivation'.

RESULTS

Eighty-nine percent wished to learn MSKUS. Factors influencing learning and practice included time to achieve competency; relative-added clinical value of MSKUS examination; limited training infrastructure; access to existing imaging service; equipment funding. Skills offering greatest clinical utility were inflammatory arthritis assessment and guided procedures; least useful were evaluation of ligament/muscle lesions and soft tissue masses. There was a close correlation between clinical utility, learning motivation and competency standard.

CONCLUSIONS

A trade-off between added clinical value and time to achieve competency is the major factor influencing practice and training in MSKUS. Most rheumatologists report limited time to devote to training and therefore need to prioritize areas of importance for dedicated learning. Educational programmes need to be highly focused and relevant to clinical and job-plan requirements in order to encourage future dissemination of MSKUS practice by rheumatologists.

The prognostic significance of lower uterine segment involvement in surgically staged endometrial cancer patients with negative nodes

OBJECTIVES

Endometrial cancer is the most common female genital malignancy in the United States. Stage is the most important prognostic factor. Other factors include grade, lymph-vascular space invasion (LVI), and myometrial invasion. Tumor location in the lower uterine segment (LUS) may also be important. LUS involvement correlates with nodal involvement, and nodal involvement is an important prognostic indicator. This study investigates the importance of LUS involvement in patients with pathologically negative nodes.

METHODS

This was an IRB approved retrospective study. Data were collected for patients diagnosed with endometrial cancer from June 1999 to September 2004. Patients who underwent nodal evaluation with no evidence of nodal disease were eligible for analysis. The primary endpoint was progression-free survival. Secondary endpoints included recurrence rate and overall survival. Analysis was performed with the JMP5.1 statistical program.

RESULTS

285 patients were identified. 85 were excluded because they received postoperative care elsewhere. 3 charts were missing, and 15 pathology reports did not mention LUS. 147 of the remaining 182 subjects had negative nodes and formed the study population. 57% of these subjects had LUS involvement. Follow-up was similar for those with and without LUS involvement at 74 vs. 73 months respectively. PFS was similar at 70 and 63 months in those with and without LUS involvement (p=0.2). Recurrence correlated with LUS involvement on univariate analysis, however, not on multivariate analysis.

CONCLUSIONS

In endometrial cancer patients with negative nodes, disease within the lower uterine segment does not imply a worse prognosis. The previously described implications of LUS involvement are likely due to the strong association of LUS disease with lymph node spread.

Ultrasonography for rheumatologists: the development of specific competency based educational outcomes

BACKGROUND

A competency based approach to the education of rheumatologists in musculoskeletal ultrasonography (MSK US) ensures standards are documented, transparent, accountable, and defensible, with clear benefit to all stakeholders. Specific competency outcomes will facilitate informed development of a common curriculum and structured programme of training and assessment.

OBJECTIVE

To determine explicit competency based learning outcomes for rheumatologists undertaking MSK US.

METHODS

International experts in MSK US, satisfying specific selection criteria, were asked to define the minimum standards required by a rheumatologist to be judged competent in MSK US. They reviewed 115 MSK US skills, comprising bone and soft tissue pathology, in seven joints regions of the upper and lower limbs, and rated their relative importance according to specific criteria. These data are presented as specific educational outcomes within designated competency categories.

RESULTS

57 expert MSK US practitioners were identified and 35 took part in this study. Ten generic core competency outcomes were recognised including physics, anatomy, technique, and interpretation. Regarding specific regional competencies, 53% (61/115) were considered "must know" core learning outcomes, largely comprising inflammatory joint/tendon/bone pathology and guided procedures; 45% (52/115) were required at an intermediate/advanced level (18/115 "should know", 34/115 "could know"), and 2% (2/115) were deemed inappropriate/unnecessary for rheumatologist ultrasonographers.

CONCLUSIONS

This is the first study to developing a competency model for the education of rheumatologists in MSK US based on the evidence of international experts. A specific set of learning outcomes has been defined, which will facilitate future informed education and practice development and provide a blueprint for a structured rheumatology MSK US curriculum and assessment process.

Early rheumatoid arthritis is associated with a deficit in the CD4+CD25high regulatory T cell population in peripheral blood

OBJECTIVE

Our aim was to test the hypothesis that there is a deficit in the CD4+CD25high regulatory T-cell population in early rheumatoid arthritis (RA), either in size or functional activity.

METHODS

Peripheral blood mononuclear cells were examined from subjects with early active RA who had received no previous disease-modifying therapy (n = 43), from individuals with self-limiting reactive arthritis (n = 14), from subjects with stable, well-controlled RA (n = 82) and from healthy controls (n = 72). The frequencies of CD4+CD25high T-cells were quantified using flow cytometry, and function was assessed by the ability to suppress proliferation of CD4+CD25- T-cells. Paired blood and synovial fluid was analysed from a small number of RA and reactive arthritis patients.

RESULTS

There was a smaller proportion of CD4+CD25high T-cells in the peripheral blood of early active RA patients (mean 4.25%) than in patients with reactive arthritis or in controls (mean 5.90 and 5.30%, respectively, P = 0.001 in each case). Frequencies in stable, well-controlled RA (mean 4.63%) were not significantly different from early active RA or controls. There were no differences in suppressor function between groups. Higher frequencies of CD4+CD25high T-cells were found in synovial fluid than blood in both RA and reactive arthritis.

CONCLUSIONS

These data demonstrate a smaller CD4+CD25high regulatory T-cell population in peripheral blood of individuals with early active RA prior to disease-modifying treatment. This may be a contributory factor in the susceptibility to RA and suggests novel approaches to therapy.

Presence of significant synovitis in rheumatoid arthritis patients with disease-modifying antirheumatic drug–induced clinical remission: Evidence from an imaging study may explain structural progression

OBJECTIVE

More timely and effective therapy for rheumatoid arthritis (RA) has contributed to increasing rates of clinical remission. However, progression of structural damage may still occur in patients who have satisfied remission criteria, which suggests that there is ongoing disease activity. This questions the validity of current methods of assessing remission in RA. The purpose of this study was to test the hypothesis that modern joint imaging improves the accuracy of remission measurement in RA.

METHODS

We studied 107 RA patients receiving disease-modifying antirheumatic drug therapy who were judged by their consultant rheumatologist to be in remission and 17 normal control subjects. Patients underwent clinical, laboratory, functional, and quality of life assessments. The Disease Activity Score 28-joint assessment and the American College of Rheumatology remission criteria, together with strict clinical definitions of remission, were applied. Imaging of the hands and wrists using standardized acquisition and scoring techniques with conventional 1.5T magnetic resonance imaging (MRI) and ultrasonography (US) were performed.

RESULTS

Irrespective of which clinical criteria were applied to determine remission, the majority of patients continued to have evidence of active inflammation, as shown by findings on the imaging assessments. Even in asymptomatic patients with clinically normal joints, MRI showed that 96% had synovitis and 46% had bone marrow edema, and US showed that 73% had gray-scale synovial hypertrophy and 43% had increased power Doppler signal. Only mild synovial thickening was seen in 3 of the control subjects (18%), but no bone marrow edema.

CONCLUSION

Most RA patients who satisfied the remission criteria with normal findings on clinical and laboratory studies had imaging-detected synovitis. This subclinical inflammation may explain the observed discrepancy between disease activity and outcome in RA. Imaging assessment may be necessary for the accurate evaluation of disease status and, in particular, for the definition of true remission.

Abnormal cervical cytology: a risk factor for endometrial cancer recurrence

The objective of this study was to evaluate the relationship between cervical cytology, histologic type, and risk of endometrial cancer recurrence. We performed a retrospective study of patients undergoing surgery for endometrial carcinoma. Risk factors for recurrence including histology, tumor grade, nodal status, myometrial invasion, peritoneal washings, stage, and cervical cytology were assessed. Abnormal cervical cytology was defined as the presence of any endometrial cells on Pap smear. Papillary serous and clear cell carcinomas were considered high-risk histologies. Univariate and multivariate analyses of risk factors for recurrence were performed. Thirty-nine (9%) patients developed recurrent endometrial cancer. More patients with abnormal Pap smears recurred (12% versus 4%, P < 0.05). For endometrioid adenocarcinoma, abnormal cervical cytology occurred in 61% and 7% recurred, while with high-risk histologies, 84% had abnormal cervical cytology and 19% recurred (P < 0.05). Other significant predictors of recurrence on univariate analysis were myometrial invasion, nodal status, washings, stage, and histology. On multivariate analysis, only nodal status remained a significant predictor of recurrence. Abnormal cervical cytology is associated with increased risk of endometrial cancer recurrence. Abnormal cervical cytology occurs more frequently in high-risk histologies, which are known to have a higher risk of recurrence. On multivariate analysis, only nodal spread remains a significant predictor of recurrence.

New approaches to imaging early inflammatory arthritis

Imaging techniques such as musculoskeletal ultrasonography (MUS) and magnetic resonance imaging (MRI) are playing an increasingly important role in the assessment of patients with inflammatory arthritis. Such modalities are now used routinely in the evaluation of joint, tendon and soft tissue inflammation and bone damage in many early arthritis clinics. They have the ability to directly visualise, characterise and quantify the earliest inflammatory changes and have proved not only to be useful additional complimentary clinical tools to improve the speed and accuracy of diagnosis, direct appropriate treatment, monitor response to therapy, measure disease progression and outcome but also continue to contribute to our understanding of disease pathogenesis. These imaging methods may therefore offer a significant advantage as they endorse the principles of early diagnosis and optimal targeted therapy essential to providing the most favourable long term outcome for patients with inflammatory arthritis. This article reviews the current evidence supporting the role of MUS and MRI in the assessment of patients with inflammatory arthritis.

Validation and reproducibility of ultrasonography in the detection of synovitis in the knee: A comparison with arthroscopy and clinical examination

OBJECTIVE

Accurate detection of synovitis is important in both the diagnosis and outcome assessment of arthritis. This study was undertaken to assess the validity and reproducibility of ultrasonography (US) as a means of detecting synovitis in the knee, by comparing US findings with findings of arthroscopy and clinical examination.

METHODS

Sixty consecutive patients with knee pain due to various arthritides had a clinical examination and US of their knee performed immediately prior to arthroscopy. All 3 assessments were performed by different clinicians who were blinded to the results obtained with the other modalities. US and clinical examination were compared with arthroscopically detected synovitis as the gold standard. Data from a subset of patients were used for calculating the inter- and intrareader reproducibility of US results, using a standard dichotomous (absence/presence of synovitis) as well as a graded (absence/grade of synovitis) scoring system.

RESULTS

With the use of arthroscopy as the gold standard, US had a higher sensitivity (98% versus 85%), specificity (88% versus 25%), accuracy (97% versus 77%), positive predictive value (98% versus 88%), and negative predictive value (88% versus 20%) compared with clinical examination. The Cohen kappa values for inter- and intrareader reproducibility of US for distinguishing between presence and absence of synovitis were 0.71 and 0.85, respectively (P < 0.05 for both). The weighted kappa values for distinguishing grade of synovitis were 0.65 for inter- and 0.74 for intrareader reproducibility. The kappa value for intrareader reproducibility of arthroscopy results was 0.88.

CONCLUSION

Ultrasonography is a valid and reproducible technique for detecting synovitis in the knee, and is more accurate than clinical examination. It may be valuable as a tool in studies investigating pain, diagnosis, and treatment response in knee arthritis.

The role of ultrasonography and magnetic resonance imaging in early rheumatoid arthritis

Advances in ultrasound (US) and magnetic resonance imaging (MRI) techniques have provided new methods for evaluating early rheumatoid arthritis (RA). Their diagnostic properties in terms of detecting primary pathology of RA (i.e., erosions, bone changes, synovitis, tenosynovitis, and effusion) are reviewed. High-resolution US plays a significant role in therapeutic and diagnostic procedures. MRI also assists in the understanding of RA pathogenesis and joint mechanics.

Normative data on neuropsychological tests for very old adults living in retirement villages and hostels

Normative data on neuropsychological tests for very old adults living in retirement villages and hostels are under-represented in the literature. This study reports normative data on the Mini-Mental State Examination, Digit Span Forwards, Digit Span Backwards, the Digit Symbol Substitution Test, the Controlled Oral Word Association Test, the Stroop Neuropsychological Screening Test and the National Adult Reading Test. Age and education showed moderate correlations with neuropsychological test performance. For all tests except the Stroop, differences between residents of retirement villages and hostels were explained by age and education. Men performed better on the NART than women, but this difference was eliminated when education was controlled for statistically.

Factors relating to readmission of term and near-term neonates in the first two weeks of life. Early Discharge Survey Group of the Health Professional Advisory Board of the Greater New York Chapter of the March of Dimes

AIMS

A multisite study of term and near term infants readmitted in the first two weeks of life to 9 New York City area hospitals in 1995 was conducted to evaluate factors related to readmission, including length of newborn stay.

RESULTS

Of the 30,884 infants born at the 9 study hospitals 391 newborns were readmitted. The major admission diagnoses were infection, 40.7%, hyperbilirubinemia, 39.1%, and feeding and/or gastrointestinal problems, 10.5%. In the first week, 65.1% of readmissions were for hyperbilirubinemia and 19.1% were for infection or suspected sepsis. In the second week, 67.8% of readmissions were for infection and 7.6% were for hyperbilirubinemia. Hyperbilirubinemia was the most frequent diagnosis for White and Asian infants, while infection was most frequent for African-American and Hispanic infants. Age at readmission was younger and the interval from discharge was shorter for infants with hyperbilirubinemia. Abnormalities which should have precluded early discharge included feeding difficulties, cyanotic congenital heart defects, hemolytic disease of the newborn, early jaundice or early high bilirubin levels.

CONCLUSION

Attention to identification of infants at risk and programs such as lactation counseling and universal screening for bilirubin (with appropriate interpretation) prior to discharge could have reduced the necessity for readmission regardless of the newborn length of stay.

Oesophageal atresia, related malformations, and medical problems: a family study

Oesophageal atresia (OA) and tracheo-oesophageal fistula (TOF) are life-threatening malformations of generally undefined cause. Previous reports of familial cases suggest a genetic contribution. The pattern of inheritance appears non-Mendelian, i.e., multifactorial. Individuals with OA/TOF often have other malformations and medical problems. The aim of this study was to determine the association in OA/TOF cases and healthy control subjects of associated malformations, midline defects, and medical conditions. We also investigate the relationships of these conditions in the relatives of the cases and controls. The results show that infants with OA/TOF frequently have VACTERL anomalies (vertebral, 17%; anal, 12%; cardiac, 20%; renal, 16%; limb, 10%) and other midline defects (cleft lip and palate, 2%; sacral dysgenesis, 2%; urogenital anomalies, 5%). The following medical problems were also reported: oesophageal dysmotility, 21%; gastro-oesophageal reflux, 22%; chest infections, 6%; and autonomic dysfunction, 0.5%. The first-degree relatives of children with OA are much more likely to have one of the aforementioned malformations or medical conditions when compared with the control group: one or more VACTERL anomalies (P < 0.01), gastro-oesophageal reflux (P < 0.05), recurrent respiratory infections (P < 0.05), and autonomic dysfunction (P < 0.001). The more distant relatives also show an increased incidence of such problems although in this case the data must be viewed with caution. The results confirm that the associated malformations and related medical problems occur significantly more frequently in the relatives of individuals with OA/TOF. These families may prove valuable for linkage analysis in an attempt to determine the genetics of OA/TOF.

Continuous foaming for protein recovery: part I. Recovery of beta-casein

Foam separation is known to have potential for separation of biological molecules with a range of surface activities. A statistical study (factorial design) was carried out to establish the optimum operating conditions for the continuous foam separation of beta-casein. Maximum values of enrichment of beta-casein into the foam phase were found for low levels of initial feed protein concentration, gas flow rate, feed-flow rate, and high foam heights. Maximum values of protein recovery, were generally found at high levels of initial feed protein concentration, gas-flow rate, feed-flow rate, and low foam heights. The highest values obtained for enrichment and separation ratio were 54.7 and 181.3, respectively, with a simultaneous protein recovery of 62%; thus, illustrating the potential effectiveness of this technique. The effect of foaming on protein conformation is also important, and in this study protein structure was analyzed before and after foam separation experiments. Techniques used were: native polyacrylamide gel electrophoresis (PAGE), UV absorbance spectroscopy, circular dichroism, and fluorescence. Native PAGE showed no detectable changes in protein structure. However, absorbance scanning, fluorimetry, and circular dichroism revealed some conformational changes over a range of concentration effects.

Continuous foaming for protein recovery: part II. Selective recovery of proteins from binary mixtures

Foam separation may have potential for protein recovery. However, for foam separation to be a viable protein recovery technique it is important to demonstrate, not only that high enrichments and recoveries can be achieved for single proteins, but also that high enrichments and recoveries, together with selectivity of partition, can be achieved for recovery from multi-component mixtures. Most process streams which require purification are indeed complex multi-component mixtures, for example, fermentation broths. In this study, three binary protein mixtures were chosen for continuous foam separation: beta-casein:lysozyme; Bovine serum albumin (BSA):lysozyme and beta-casein:BSA (mixtures 1, 2, and 3, respectively). For each of these mixtures, the expected outcome of each experiment, based on a previous knowledge and determination of relevant protein physical properties, was that the first protein should be preferentially separated into the foam phase. On the basis of results reported in Part I of this study for the continuous foam separation of beta-casein, conditions found to favor maximum enrichment were selected. For each mixture a range of concentrations of both proteins was considered. For mixture 1, maximum protein recoveries in the foam phase were 85.6% and 25% for beta-casein and lysozyme, respectively; and for mixture 2, maximum recoveries of 77. 6% and 18.9% were obtained for BSA and lysozyme, respectively. Maximum enrichment ratios in the foam phase were 79.4 and 2.5 for beta-casein and lysozyme respectively in mixture 1; and 74.0 and 1.4 for BSA and lysozyme respectively in mixture 2. Selective partitioning of beta-casein and BSA into the foam phase was obtained in mixtures 1 and 2, respectively, particularly for protein concentrations at which dilute protein films are known to form at the gas-liquid interface in the foam. Maximum partition ratios for mixtures 1 and 2 were 31.8 and 52.8, respectively. For mixture 3, both BSA and beta-casein were enriched into the foam phase. Maximum enrichments were 42.9 and 24.7 for BSA and beta-casein, respectively; however, selective partitioning in mixture 3 was limited (maximum partition ratio being 1.8).

A randomized trial of a consultation service to reduce falls in nursing homes

CONTEXT

Falls are a major health problem in nursing homes, but no interventions have been shown to prevent falls in nursing home residents.

OBJECTIVE

To evaluate an intervention program designed to prevent falls and associated injuries in high-risk nursing home residents.

DESIGN

Randomized controlled trial.

SETTING AND PARTICIPANTS

Seven pairs of middle Tennessee nursing homes with 1 facility in each pair randomly assigned to the intervention. Facilities had 482 (261 control, 221 intervention) residents who qualified for the study because they had high risk of falls and a potential safety problem that could be addressed by the intervention.

INTERVENTION

Comprehensive structured individual assessment with specific safety recommendations that targeted suboptimal practices for environmental and personal safety, wheelchair use, psychotropic drug use, and transferring and ambulation. Facility staff were encouraged to implement the individual recommendations and to improve overall facility safety.

MAIN OUTCOME MEASURES

The mean proportion of recurrent fallers and incidence rate of injurious falls in the facility in the year following the intervention.

RESULTS

The mean proportion of recurrent fallers in intervention facilities (43.8%) was 19.1% (95% confidence interval, 2.4%-35.8%) lower than that in control facilities (54.1%, P=.03). Intervention facilities had a nonsignificant trend toward a lower mean rate of injurious falls (13.7 vs 19.9 per 100 person-years, reduction of 31.2%, P=.22). Subgroup analyses suggested greatest benefits for residents for whom the recommended interventions were carried out or who had 3 or more falls in the preceding year.

CONCLUSION

The high rate of falls and related injuries in nursing homes should not be viewed as inevitable, but as outcomes that can be substantially improved through structured safety programs.

Pregnancy in sickle cell disease: experience of the Cooperative Study of Sickle Cell Disease

OBJECTIVE

To determine the maternal and fetal outcomes of pregnancy in women with sickle cell disease.

METHODS

The subjects were part of a cohort recruited from 19 centers for a prospective study of the clinical course of sickle cell disease. Each participant was evaluated using a structured protocol in which steady-state data and information on both sickle- and non-sickle-related events were collected. The rates of antepartum and intrapartum complications were tallied for pregnancies carried to delivery. Fetal outcome was assessed according to gestational age, birth weight, and Apgar score. Differences among genotypes in event rates were assessed using Fisher exact test. Differences in gestational age and birth weight, and predictors of these outcomes, were assessed using analyses of covariance.

RESULTS

Two hundred eighty-six of the 445 reported pregnancies proceeded to delivery. Non-sickle-related antepartum and intrapartum complication rates were comparable with those of African-American women who did not have sickle cell disease. One of the two deaths observed during this study was directly related to the presence of sickle cell disease. Rates of maternal morbidity from sickle cell disease were the same during pregnancy as during the nonpregnant state. Ninety-nine percent of those pregnancies carried to delivery resulted in a live birth. Twenty-one percent of the infants born to women of the SS genotype were small for gestational age (SGA). Preeclampsia and acute anemic events were identified as risk factors for SGA infants.

CONCLUSIONS

Those caring for women with sickle cell disease should support them if they desire to have children.

Measurement of gap length in esophageal atresia: a simple predictor of outcome

BACKGROUND

Previous classifications of esophageal atresia (EA) and tracheoesophageal fistula (TEF) have concentrated on associated medical conditions that influence survival. We propose a classification based on gap lengths to define the magnitude of the surgical problems in EA and TEF and correlate them with outcome.

STUDY DESIGN

Gaps between the esophageal ends were classified as long (greater than 3 cm), intermediate (greater than 1 cm but less than or equal to 3 cm) or short (less than or equal to 1 cm). A series of 66 consecutive patients with EA and TEF were studied.

RESULTS

The outcomes of patients with long (n = 16), intermediate (n = 16), and short (n = 34) gaps were respectively: death (18 percent, 6 percent, 3 percent), anastomotic leak (31 percent, 25 percent, 6 percent), stricture (44 percent, 31 percent, 17 percent), recurrent TEF (6 percent, 6 percent, 6 percent), gastroesophageal reflux (56 percent, 37 percent, 36 percent), and failure to thrive (56 percent, 43 percent, 18 percent). The mean hospital stay at first admission was (97, 54, 24 days, respectively) and the mean number of readmissions was (6.9, 5.2, 3.4, respectively).

CONCLUSIONS

This classification, which is based on easily measurable criteria, provides a useful method to predict morbidity, long-term outcome, and health costs associated with EA and TEF surgery.

Surgery and anesthesia in sickle cell disease. Cooperative Study of Sickle Cell Diseases

From 1978 to 1988, The Cooperative Study of Sickle Cell Disease observed 3,765 patients with a mean follow-up of 5.3 +/- 2.0 years. One thousand seventy-nine surgical procedures were conducted on 717 patients (77% sickle cell anemia [SS], 14% sickle hemoglobin C disease [SC], 5.7% S beta zero thalassemia, 3% S beta zero + thalassemia). Sixty-nine percent had a single procedure, 21% had two procedures, and the remaining 11% had more than two procedures during the study follow-up. The most frequent procedure was abdominal surgery for cholecystectomy or splenectomy (24% of all surgical procedures, N = 258). Of these, 93% received blood transfusion, and there was no association between preoperative hemoglobin A level and complication rates (except reduction in pain crisis). Overall mortality within 30 days of a surgical procedure was 1.1% (12 deaths after 1,079 surgical procedures). Three deaths were considered to be related to the surgical procedure and/or anesthesia (0.3%). No deaths were reported in patients younger than 14 years of age. Sickle cell diseases (SCD)-related complications after surgery were more frequent in SS patients who received regional compared with general anesthesia (adjusted for risk level of the surgical procedure, patient age, and preoperative transfusion status, P = .058). Non-SCD-related postoperative complications were higher in both SS and SC patients who received regional compared with those who received general anesthesia (P =.095). Perioperative transfusion was associated with a lower rate of SCD-related postoperative complications for SS patients undergoing low-risk procedures (P = .006, adjusted for age and type of anesthesia), with crude rated of 12.9% without transfusion compared with 4.8% with transfusion. In SC patients, preoperative transfusion was beneficial for all surgical risk levels (P = .009). Thus, surgical procedures can be performed safely in patients with SCD.

Clinical events in the first decade in a cohort of infants with sickle cell disease. Cooperative Study of Sickle Cell Disease

Within the Cooperative Study of Sickle Cell Disease, 694 infants with confirmed sickle cell disease were enrolled at less than 6 months of age. Information about the nature and frequency of complications was collected prospectively over a 10-year period. Painful crises and acute chest syndrome were the most common sickle cell-related events in homozygous sickle cell anemia (SS), hemoglobin SC disease (SC), and S beta thalassemia patients (overall incidence in SS patients of 32.4 and 24.5 cases per 100 person-years, respectively). Bacteremia occurred most frequently in SS children under 4 years of age and in SC patients less than 2 years of age. The mortality rate was low in this cohort compared with that found in previous reports. Twenty children, all with Hb SS, died (1.1 deaths per 100 person-years among SS patients). Infection, most commonly with Streptococcus pneumoniae and Hemophilus influenzae, caused 11 deaths. Two children died of splenic sequestration, 1 of cerebrovascular accident, and 6 of unclear causes. Two patients underwent cholecystectomies, and 17 underwent splenectomies after one or more splenic sequestration crises. The experience of this cohort should reflect closely the true clinical course of those children with Hb SS and Hb SC disease who are observed in sickle cell centers in the United States.

Glucose-6-phosphate dehydrogenase deficiency and carboxyhemoglobin concentrations associated with bilirubin-related morbidity and death in Nigerian infants

Our objective was to determine whether glucose-6-phosphate dehydrogenase (G6PD) deficiency and elevated carboxyhemoglobin (COHb) levels correlated with bilirubin-related morbidity and mortality rates. For this purpose, we studied 55 clinically jaundiced infants admitted to a rural mission hospital in southern Nigeria. Total serum bilirubin levels (range, 80 to 1016 mumol/L (4.7 to 59.4 mg/dl)) correlated with the percentage COHb concentrations (COHb = 0.45 + 0.08 Total serum bilirubin; r = 0.72). Infants were divided into two groups of equal size around the median COHb concentration (COHb range, 0.43% to 5.93% (median = 1.40%), with ambient carbon monoxide of 0.65 +/- 0.03 microL/L). The COHb levels > or = 1.40% were associated with the need for exchange transfusion (15/28, or 54%, vs 5/27, or 19%; p < 0.01) and with an increased incidence of clinical findings compatible with kernicterus (9/28, or 32%, vs 0/27, or 0%; p < 0.01). Mortality rate was 29% (8/29) among infants with higher COHb levels, and 7% (2/28) in those with lower levels (p = 0.08). Thirty-one percent (14/45) of the clinically jaundiced infants tested had G6PD deficiency. Thirty-six percent of the infants with G6PD deficiency died with presumed kernicterus, compared with only 3% (1/31) of the infants with a normal G6PD screening test result (p < 0.01). These data suggest that G6PD deficiency and increased bilirubin production, as indexed by COHb, are associated with jaundice-related morbidity and death in Nigerian infants.

The influence of infant and maternal sickle cell disease on birth outcome and neonatal course

OBJECTIVE

To compare the influence of maternal hemoglobin phenotype as well as that of the infant on birth outcome and neonatal complications.

RESEARCH DESIGN

Prospective, natural history study with retrospective chart review for neonatal complications.

SETTING

Nineteen pediatric sickle cell centers across the United States.

PATIENTS

Four hundred eighty infants with sickle cell disease (SCD) who were enrolled in the Cooperative Study of Sickle Cell Disease at less than 6 months of age, as well as a comparison cohort of 118 infants with sickle cell trait born to women with sickle cell anemia in the Cooperative Study.

RESULTS

In the SCD cohort, overall rates of preterm (< 37 weeks), low-birth-weight (< 2500 g), and small-for-gestational age births were 9%, 10%, and 8%, respectively; no significant differences were found according to infant hemoglobin phenotype. Term births accounted for 59% of the infants with low birth weight, significantly higher than the 41% US rate for black low-birth-weight infants (P = .014). Expectant mothers with sickle cell anemia are 2.5 times more likely to bear newborns who are small for gestational age than are women with other types of sickle cell disease, sickle trait, or C-trait. The most common prepartum and neonatal complications in infants with SCD were jaundice (25%), fetal distress (13%), anemia (10%), and respiratory distress (6%). Complication rates did not differ significantly by hemoglobin phenotype in the infants with SCD, but infants born to women with sickle cell anemia had higher rates of jaundice (P < .0001).

CONCLUSIONS

Rates of adverse birth outcomes and neonatal complications in infants with SCD are similar to the rates for normal infants, although preterm birth accounts for fewer of the low-birth-weight outcomes among newborns with SCD relative to US black newborns. The hemoglobin phenotype of infants with SCD does not influence birth outcome and neonatal course, but infants born to women with sickle cell anemia are at greater risk of preterm birth, low birth weight, being small for gestational age, and neonatal jaundice.

Reference values and hematologic changes from birth to 5 years in patients with sickle cell disease. Cooperative Study of Sickle Cell Disease

OBJECTIVE

To examine hematologic changes from birth to 5 years of age and establish hematologic reference values for infants and children with sickle cell disease.

RESEARCH DESIGN

Prospective natural history study.

SETTING

Nineteen pediatric sickle cell centers across the United States.

PATIENTS

Six hundred ninety-four infants with sickle cell disease (sickle cell anemia, sickle cell-hemoglobin C disease, and sickle-beta-thalassemia) who were enrolled in the Cooperative Study of Sickle Cell Disease at younger than 6 months of age. Median follow-up time through 5 years of age was 4.1 years.

MEASUREMENTS AND RESULTS

We present longitudinal analyses of total hemoglobin concentration, percent fetal hemoglobin values, mean corpuscular volumes, total bilirubin concentration, and red blood cell (RBC), "pocked" RBC, white blood cell, platelet, and reticulocyte counts. Anemia was apparent by 10 weeks of life in infants with sickle cell anemia (SS infants). This anemia was associated with a rising reticulocyte count consistent with a hemolytic process. The reticulocyte count of SS infants increased steadily, exceeding 12% at 5 years of age. The fetal hemoglobin concentration of SS infants declined more slowly than that of infants with sickle cell hemoglobin C disease (SC infants). Pocked RBC counts rose sharply after 6 months of age, and by 1 year, 28% of SS infants had abnormal counts, above 3.5%, indicating poor splenic function. At 3 years of age, 78% of SS patients and 32% of SC patients had abnormal pocked RBC counts. The SS patients with concurrent alpha-thalassemia had, after 6 months of age and throughout early childhood, a slightly higher mean total hemoglobin concentration and lower mean pocked RBC and reticulocyte counts than SS patients without alpha-thalassemia. The hematologic profile of SC infants more closely resembled that of normal black infants, but there was mild anemia (10.5 g/dL) and slightly elevated mean values for reticulocytes (3%) and fetal hemoglobin (3%) during early childhood.

Effects of delayed reinforcement on infant vocalization rate

Three previous studies have failed to demonstrate conditioning in infants using a 3-s delay of reinforcement. The effects of a delayed reinforcement schedule on vocalization rates therefore were explored in a single-subject repeated-reversal experimental design for 3 4- to 6-month-old normally developing infants. Each infant received delayed social reinforcement from his or her parent for vocalizing. The comparison condition was a schedule of differential reinforcement of behavior other than vocalizations to control for elicitation by social stimulation. An operant level of infant vocalizations was the initial condition, after which the differential reinforcement schedule was implemented in an across-subjects multiple baseline design. Infants' vocalization rates increased above levels measured during differential reinforcement following onset of the delayed reinforcement condition. Also, vocalization rates decreased during differential reinforcement compared to operant levels. The successful use of delayed reinforcement schedules with infants in this study, as opposed to others, is discussed in terms of procedural differences among them.