Abnormal cranial magnetic resonance imaging scans in sickle-cell disease. Neurological correlates and clinical implications.

OBJECTIVE: Eight asymptomatic patients with sickle-cell disease (SCD) with magnetic resonance imaging (MRI) abnormalities consistent with cerebral infarcts (group 1) and eight asymptomatic patients with SCD with normal MRI scans (group 2) were followed up to assess the neurological correlates and the clinical outcome. DESIGN: Patients in the two cohorts underwent clinical evaluations and xenon 133 regional cerebral blood flow (rCBF) studies within 1 month of the entry MRI. This study sequence was repeated up to 5 years later. Neuropsychological studies also were performed in six group 1 patients and eight group 2 patients at the end of the study. SETTING: The patients were recruited from the Comprehensive Sickle Cell Center at Columbia University, New York, NY. PATIENTS: All patients had SCD, hemoglobin SS, and normal findings on clinical evaluation at entry. The group 1 cohort had clinically silent MRI abnormalities consistent with cerebral infarction. The group 2 cohort was age matched to group 1 and had normal MRI studies. INTERVENTIONS: None. MAIN OUTCOME MEASURE: The natural history of MRI abnormalities and the neurological correlates were assessed to determine the predictive value of subclinical MRI lesions as a risk factor for clinically apparent stroke. RESULTS: The mean duration of MRI follow-up was 3.7 years. In group 1, four patients (50%) demonstrated progressive MRI abnormalities and three patients (38%) became clinically symptomatic. In group 2, findings for all patients remained normal on clinical and radiological examination. Both groups had markedly elevated rCBF values. Individual rCBF differences correlated with the specific MRI abnormalities. The psychometric study results were similar in the two cohorts. Eighty-three percent of group 1 and 88% of group 2 patients had defective scores in one or more areas of cognitive functioning. Three patients met cognitive criteria for dementia. CONCLUSIONS: Cranial MRI abnormalities have important prognostic implications even when detected in clinically asymptomatic patients. Cognitive abnormalities exist in patients with SCD even in the absence of MRI abnormalities or clinical stroke.

Child health 2000: new pediatrics in the changing environment of children's needs in the 21st century.

Pediatric practice in the next millennium will require greater knowledge of new morbidities, such as acquired immunodeficiency syndrome and social and behavioral disorders, reemergent old disorders, such as tuberculosis, and disorders rarely seen of late in the United States but now being brought here by recent immigrants, such as malaria and other parasitic diseases. Diversity in ethnic and cultural backgrounds and beliefs will continue to increase, and it will need to be understood to prevent and treat diseases of children effectively. Although the current antagonism toward immigrants may lead to a decrease in this particular source of diversity, changes in family structure--such as divorce, gay and lesbian couples as parents, and corporate pressure on families--will continue, requiring pediatricians to understand and to accept this diversity if they are to be the health care providers of children. The increased isolation of individuals from society and separation from families of origin will require pediatricians to be more active in communities and schools and to participate with other disciplines and social support groups. At the same time, the advancement of science and technology will continue to drive what the pediatrician does. Increased survival of children who previously had fatal illnesses will mean more emphasis on care of children who have chronic illnesses. Pediatricians will need to be partners with others in the exciting new fields of risk assessment and prevention of psychosocial disorders.

The academic generalist: an endangered species revived.

The role of a generalist in academic medicine has been diminished because of the proliferation of specialized research and treatment in the hands of the subspecialist. Yet many observers believe that this has resulted in gaps in research and teaching concerning common health problems, especially those seen in office practice. To correct this trend, The Robert Wood Johnson Foundation has supported for 10 years a fellowship program to prepare academic pediatric generalists. A total of 111 pediatricians have completed the fellowship. Two thirds are now in full-time academic positions. By late 1988, they had published 332 papers and had received more than $20 million in grant support. A majority of departments of pediatrics have relabeled their divisions of ambulatory pediatrics as divisions of general pediatrics and have broadened these divisions' responsibilities. In spite of some difficulty obtaining research support, the carers of these fellows and the changes in pediatric departments support the thesis that there is a need for and a rebirth of academic general pediatrics.

The academic general pediatrician: is the species still endangered?

OBJECTIVE: To determine the careers of graduates of the General Pediatrics Academic Development Program (GPADP) and the pediatricians from the Clinical Scholars (CS) Program 8 to 16 years after completion of their fellowship to assess the current state of the academic general pediatrician and to determine the current activities of divisions of General Pediatrics in US medical schools. DESIGN: Analysis of questionnaire data from former fellows of the two programs, who trained during the years 1978 to 1988, as well as of data from questionnaires to all divisions of General Pediatrics (or their equivalent) in all medical schools in the United States. POPULATION: Surveys were conducted of the 111 graduates of the GPADP and the 39 pediatricians from the CS program and all 127 US medical schools. RESULTS: Of the 111 GPADP graduates, 101 were located, and 85 completed the questionnaire. Of 39 CS graduates, 36 were located, of whom 27 completed the questionnaire. Similarities were found between the two groups in percent being in academic positions (74%, GPADP vs 70.4%, CS), percent having achieved tenure (17.8%, GPADP vs 14.3%, CS), and percent of time spent in research (17%, GPADP vs 25%, CS). Considerable differences, however, were found in percent of time spent in direct patient care (35.7% time for GPADP and only 17. 8% time for CS) and in direct teaching (25.1% time for GPADP and only 17.6% time for CS). The mean number of articles published was greater among CS professionals (21.4 vs 14 for GPADP, but not statistically significant), as was the mean number of research grants (6.75 by CS vs 4.02 by GPADP). The GPADP fellows had obtained more education grants and more service grants. Both groups were concerned about the lack of time and support for research. Few General Pediatrics divisions had ongoing academic fellowship programs. The current number of new fellows by divisions of General Pediatrics who are educated to do research is small. Only 30 related programs exist in all the medical schools in the United States. However, large divisions of General Pediatrics, responsible for large teaching and clinical service programs, are now in place in the majority of medical schools. This represents progress since 1978, when few generalists were in full-time academia. CONCLUSION: More than two thirds of both the GPADP graduates and CS professionals are now in academic departments. They have had modest success in obtaining grants, publishing articles, and achieving tenure, but large teaching and service demands and lack of research funds have made it difficult for both groups to be as productive in research as originally hoped. The field of Academic General Pediatrics now is established. It is the responsibility of graduates of these and similar programs to produce creative research and expand fellowship programs, as well as to do good clinical care, if a vigorous field of Academic General Pediatrics is to be achieved.

Delivery of health care for children: report of an experiment.

This paper summarizes an experiment evaluating the effectiveness of primary pediatric care delivered to a sample of low-income inner-city families. Primary pediatric care in this study was similar to pediatric group practice. The study findings indicated that the effects of primary care compared with the episodic care received by the control families were appreciable. This included the decreasing of hospitalizations, operations, illness visits, and appointment breaking; increasing of health supervision visits, preventive services, and patient satisfactions; and accomplishing these changes at a lower cost. Patient morbidity was not altered. Medicaid made no difference in the care patterns of the experimental families and apparently benefited only those control families who were white. The controlled clinical trial offers the best opportunity to compare different models of priervices for children.

Cerebral dysfunction after cardiac operations in elderly patients.

BACKGROUND: Cerebral injury remains a significant complication of cardiac operations. We determined the incidence of cerebral dysfunction in a population of elderly patients undergoing open chamber cardiac operations (group 1) as compared with a younger population (group 2) and an age-matched group of elderly patients undergoing major noncardiac operations (group 3). METHODS: Sixty-eight patients (55 for open chamber cardiac operations and 13 for noncardiac operations) were prospectively studied. Patients were evaluated preoperatively and postoperatively before hospital discharge using a complete neurologic examination and a battery of standard neuropsychometric tests, and at surgical follow-up with neuropsychometric tests only. RESULTS: Postoperative changes detected by neurologic examination consisted of the appearance of new primitive reflexes in all groups. No statistically significant differences in incidence were found. The neuropsychometric performance of group 1 patients was statistically different from that of patients in groups 2 and 3 only in the early follow-up period. CONCLUSIONS: Elderly patients having open chamber cardiac operations exhibit significantly more cerebral dysfunction in the early postoperative period than those undergoing major noncardiac operations and younger patients after open chamber procedures. These changes do not persist into the late follow-up period.

Institute of Medicine report on prevention of mental disorders. Summary and commentary.

A comprehensive report mandated by the U.S. Congress on the state of the science of prevention recommends a stricter definition of the term prevention; summarizes specific preventive intervention research programs across the life span; and specifies funding, personnel, and coordination priorities to build a national prevention research infrastructure. A major conceptual recommendation is a focus on reducing risk for mental disorders, which has been a fruitful strategy in the prevention of physical illness. The report argues that the prevention field should also draw from advances in mental disorder treatment research and from the major contributions to the knowledge base occurring in the behavioral and biological core sciences. Relevant advances in neuroscience, genetics, epidemiology, and developmental psychopathology are examined in detail. Five major disorders are chosen to illustrate possible approaches to prevention: conduct disorder, depressive disorders, alcohol abuse and dependence, schizophrenia, and Alzheimer's disease.

Transport with multiple-rate exchange in disordered media.

We investigate transport of particles subject to exchange using the continuous-time random-walk framework. Transition is controlled by macroscale, and exchange by both macroscale and microscale disorder. A wide class of exchange mechanisms is represented using the multiple-rate exchange model. Particles are transported along random trajectories viewed as one-dimensional lattices. The solution of the transport problem is obtained in the form of the crossing-time density, h(t;L), at an exit surface L; h is dependent on two functions, g and f. g characterizes exchange controlled by microscale disorder. The joint density f is central for the solution as it relates the microscale and macroscale disorder along random trajectories. For the case of transition and exchange disorder, we show that power-law exponent eta (characterizing microscale disorder) and power-law exponents alpha(tau) and alpha(mu) (characterizing macroscale disorder), define two regions delimited by a line alpha(tau)=alpha(mu)(eta+1): One in which the asymptotic transport is dominated by transition, and one in which it is dominated by the exchange. For the case of transition disorder with uniform exchange, both transition and exchange can influence the late-time behavior of h(t). Microscale exchange processes will unconditionally influence the late-time behavior of h(t) only if eta<0. If eta>0, exchange will dominate at late time provided that transition is asymptotically Gaussian.

Youth and America's future: the forgotten half.

The William T. Grant Foundation's Commission on Youth and America's Future was created to review existing research on problems facing young people in America today, and to make policy recommendations based upon the results of that research. The Commission found that fewer economic opportunities are available today, especially to non-college-bound young people, than was the case even a decade ago. This situation has had an adverse effect on the youths themselves, their families, and ultimately, on American society as a whole. Many problem behaviors have their origin in the reduced opportunities which young people face today. The Commission cites a number of programs that show promise to ameliorate behavioral and economic problems of youth, and urges government, business, and other private agencies to join together in implementing and expanding existing programs (such as the Job Training Partnership Program) and in creating new ones (such as the Youth Opportunities Demonstration Act). Society needs to recognize the important role which youth can play as good citizens by providing opportunities for them to give needed services to the community.

Modeling solute diffusion in the presence of pore-scale heterogeneity: method development and an application to the Culebra dolomite member of the Rustler Formation, New Mexico, USA.

Previous studies have revealed the presence of pore-scale variability in diffusivity in the Culebra (dolomite) member of the Rustler Formation, NM. In this study, eight laboratory-scale diffusion experiments on five Culebra samples were analyzed using a methodology for modeling solute diffusion through porous media in the presence of multiple matrix diffusivities, Dp. A lognormal distribution of Dp is assumed within each of the lab samples. The estimated standard deviation (sigma d) of ln(Dp) within each sample ranges from 0 to 1, with most values lying between 0.5 and 1. The variability over all samples leads to a combined sigma d in the range of 1.0-1.2, which is consistent with the distribution of independently determined formation factor measurements for similar Culebra samples. A comparison of our estimation results to other rock properties suggests that, at the lab-scale, the geometric mean of Dp increases with bulk porosity and the quantity of macroscopic features such as vugs and fractures. However, sigma d appears to be determined by variability within such macroscopic features and/or by micropore-scale heterogeneity. In addition, comparison of these experiments to those at larger spatial scales suggests that increasing sample volume results in an increase in sigma d.

Breaking the link between stress and illness in children. What role can physicians play?

Six-year-old Mary has a new baby sister, and her father, who recently lost his job, is talking about moving to another city where employment opportunities are better. Mary is worried about leaving her friends and going to a new school. With her mother preoccupied with the baby and her father job hunting, Mary responds to the stress in her life by having a sore throat. In this article, Dr Haggerty urges that children like Mary must be taught to deal with stress in ways that lessen susceptibility to illness but retain the motivating and life-enhancing virtues of stress and suggests that health care providers take on the role of teacher.