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Biomedical subjects

L Peterson

Publications and source records attributed to L Peterson.

At least 91 records · Page 5Linked to original sources
PubMed1994

Assessment of complete remission after 2-chlorodeoxyadenosine for hairy cell leukemia: utility of marrow immunostaining and measurement of splenic index.

2-Chlorodeoxyadenosine (2-CdA) yields high complete remission (CR) rates in patients with hairy cell leukemia (HCL) Two approaches were used to detect minimal residual disease. We studied two B-lineage antibodies, L26 and MB2, and a T-lineage antibody, UCHL-1, in fixed marrow core biopsies from 34 patients with HCL before and after 2-CdA to detect minimal residual in the marrow. In addition, the splenic index was calculated before and after treatment to detect residual splenomegaly. Prior to therapy, hairy cells exhibited intense cytoplasmic membrane reactivity with L26 and strong intracytoplasmic reactivity with MB2. UCHL-1 did not react with hairy cells. Thirty-one patients were assessable 3 months after therapy. Five of 24 (21%) patients in CR by routine evaluation had residual HCL detected by immunostaining. Four of these 5 patients have been reevaluated at 1 year. One patient relapsed by routine evaluation, 2 remained positive by immunostaining alone, and 1 patient became negative by immunostaining. A total of 19 patients have been evaluated at 1 year and 17 remain in CR. Three of these 17 were positive by immunostaining, 2 of whom had been positive at 3 months and 1 additional patient who became positive by immunostaining at 1 year. Of 9 patients evaluated at 2 years, an additional 2 of 3 patients with minimal residual disease detected previously by immunostaining at 3 months relapsed by routine morphology and 1 had persistent positive immunostaining. Only 1 patient in remission by morphology and immunostaining has relapsed.(ABSTRACT TRUNCATED AT 250 WORDS)

Antibodies↗
PubMed1994

Carbon fiber scaffolds in the treatment of early knee osteoarthritis. A prospective 4-year followup of 37 patients.

A common treatment for deep cartilage lesions on the patella and on the femoral condyles in young and middle-aged patients is the placement of drill-holes down to the vascular subchondral bone to stimulate fibrocartilage ingrowth. The present prospective study describes experience with woven carbon fibers used as scaffolds in the drilled lesions to enhance ingrowth of a regenerative tissue. Surgery was performed on 37 patients with an average age of 39 years (range, 25-53 years) and an average followup of 48 months (range, 33-63 months). The results were assessed by 4 evaluation systems. Thirty (83%) of the 36 patients who could be observed were rated good or excellent. The most striking result was good pain relief. In conclusion, carbon fiber implants could be a promising alternative to other operative procedures for young and middle-aged patients with cartilage lesions.

Adult↗
PubMed1993

Detection of minimal residual disease by immunostaining of bone marrow biopsies after 2-chlorodeoxyadenosine for hairy cell leukemia.

2-Chlorodeoxyadenosine (2-CdA) yields high complete remission (CR) rates in patients with hairy cell leukemia (HCL). In an effort to detect minimal residual disease, we studied two B-lineage antibodies, L26 and MB2, and a T-lineage antibody, UCHL-1, in fixed marrow core biopsies from 34 patients with HCL before and after 2-CdA. Before therapy, hairy cells exhibited intense cytoplasmic membrane reactivity with L26 and strong intracytoplasmic reactivity with MB2. UCHL-1 did not react with hairy cells. Thirty-one patients were assessable 3 months after therapy. Five of 24 (21%) patients in CR by routine evaluation had residual HCL detected by immunostaining. Four of these 5 patients have been reevaluated at 1 year. One patient relapsed by routine evaluation, 2 remained positive by immunostaining alone, and 1 patient became negative by immunostaining. A total of 19 patients have been evaluated at 1 year. Only 1 additional patient has become positive by immunostaining alone. Immunostaining using the B-lineage antibodies highlighted the presence of hairy cells with preservation of morphology. This assisted in quantifying the extent of disease, particularly when hairy cells were interstitial and blended with surrounding hematopoietic tissue, when hairy cells were present in hypocellular marrows, when hairy cells were spindle-shaped, and when marrows were markedly fibrotic. Because immunostaining can be easily performed on routinely processed marrows, it is an attractive method to detect minimal residual disease. Our data suggest that some patients in apparent CR after 2-CdA may have minimal residual disease. Patients will need to be observed prospectively to determine if residual disease will be predictive of relapse.

Antibodies, Monoclonal↗
PubMed1993

Measures of children's injuries: self-reported versus maternal-reported events with temporally proximal versus delayed reporting.

Although attention has recently been focused on understanding and preventing children's injuries, much controversy exists over the best data collection methods for examining child injuries. This study examined three methodological issues relevant to childhood injury data collection including the length of time children and parents can be expected to meaningfully recall injuries, whether the parent or child is a preferred informant about the injury, and the potential use of near injuries as a proxy measure for actual child injuries. Both children and their mothers were individually interviewed every 2 weeks for a total of 6 months about both injuries and near injuries. In addition, at the end of the 6-month period, they were asked to recall all injuries that occurred during those 6 months. Overall, children reported more injuries than mothers. Children recalled far fewer and mothers recalled slightly fewer events than had been reported in the biweekly interviews. There were fewer near injury than actual injury events reported, although this varied across categories, with some categories (e.g., car passenger injuries) having more near than actual injuries, and other categories (e.g., cuts, bumps, and bruises) having many more actual than near injuries reported. Limitations of the project are discussed and implications for future research advanced.

Accident Proneness↗
PubMed1993

Society of Pediatric Psychology Task Force Report: pediatric psychology and injury control.

Injuries are the major causes of death for children. Pediatric psychology offers significant contributions to the multidisciplinary efforts necessary to prevent injuries and reduce harm to children. This Task Force Report reviews epidemiological data, characteristics of children's injuries, passive and active interventions for reducing injuries, and research, policy, and evaluation issues for individual and community injury control efforts. Directions for future pediatric psychology efforts are identified and placed in a context of collaborative efforts required to advance the control of children's injuries.

Adolescent↗
PubMed1993

Empirically derived injury prevention rules.

This study describes a set of empirically derived safety rules that if followed, would have prevented the occurrence of minor injuries. Epidemiologists have criticized behavioral interventions as increasing "safe" behavior but failing to demonstrate a decrease in injury. The present study documents retrospectively the link between safe behavior and injury. It demonstrates that these empirically derived rules are very similar to rules for the prevention of serious injury. The study also shows that these rules are not widely accepted and implemented by parents. Suggestions for future research in this area are advanced.

Accident Prevention↗
PubMed1993

Benign lymphocytosis and reactive neutrophilia. Laboratory features provide diagnostic clues.

Peripheral blood leukocytoses are some of the most common abnormalities observed in the clinical hematology laboratory. This article discusses both benign lymphocytosis and reactive neutrophilia. Laboratory features and clinical syndromes associated with each of these specific leukocytoses and diagnostic considerations including differentiation from malignant disorders are addressed.

Diagnosis, Differential↗
PubMed1993

Judgments regarding appropriate child supervision to prevent injury: the role of environmental risk and child age.

Parents, social service workers, and medical personnel failed to differ in the amount of time they estimated that children of 11 differing ages should be left without adult supervision within 5 different supervision domains. More hazardous circumstances dramatically reduced the amount of time respondents said children should be left unsupervised. Amount of unsupervised time increased with age, with clear developmental cutoffs that varied by level and type of risk. When the moderate center of the distribution was examined, 3 clear areas of consensus emerged. For most domains, constant supervision was recommended for preschool children. For early elementary school children, nearly constant (0-5 min without supervision) or close (0-15 min without supervision) supervision was recommended in safer locations, with constant supervision still recommended in high-risk situations. Only with older children was there an absence of consensus regarding supervision. The implications of these results for future injury prevention research are discussed.

Adult↗
PubMed1992

Complacency, misdirection, and effective prevention of children's injuries.

Injuries are the leading killer of children in the United States, yet most parents, communities, and legislatures remain uncommitted to effective injury prevention. Possible reasons for this complacency are described, and effective methods, likely targets, and useful tactics for prevention are reviewed. The greatest challenges to injury preventionists are to persuade those who remain uninformed concerning the importance of injury prevention, to redirect those efforts currently devoted to ineffective interventions, to continue to evaluate and implement effective preventive interventions, and to search for improved prevention strategies.

Attitude to Health↗
PubMed1992

Analogs of cyclosporin A modified at the D-Ala8 position.

The conversion of [2-deutero-3-fluoro-D-Ala8]cyclosporin A (1) to a dehydroalanine analog [delta-Ala8]cyclosporin A (2) was achieved with lithium diisopropylamide in THF at low temperature. This dehydro compound is a useful intermediate for the preparation of position 8 analogs of cyclosporin A formed from it by the conjugate addition of thiol compounds. NMR conformational studies have provided evidence for the restoration of D-stereochemistry in the modified Ala8 residues. The preparation of several of these cyclosporin analogs and their bioactivities are described.

Animals↗
PubMed1992

Health consequences of behaviors: injury as a model.

Injury is the third leading cause of death in the United States and the leading cause for children, adolescents, and young adults. Injury results from multiple factors and so may its prevention. The first and simplest approach toward preventing injuries has been to innovatively and aggressively apply a traditional public health model. Strategically, the goal has been to remove harmful agents of injury and to make the environment safer. Tactics such as public information, product regulation, legislative action, and the like have been credited with reductions in mortality and morbidity. To expand our understanding and our prevention strategies across multiple injuries, other scientific knowledge bases and intervention models from fields such as psychology and child development are being used to study childhood injury. These approaches show that in addition to environmental determinants, psychosocial factors involving both the care giver and the child are related to injury. The research programs described here illustrate the advantage of investigating psychosocial factors at both molar and molecular levels. General characteristics of mothers and children related to injury help define families at risk, as well as suggesting vehicles for intervention. Behavioral factors influencing risk perception highlight the etiology of increased risk in adolescence. Injury episodes, even slight, as well as "near injuries" and dangerous and risky behavior can be quantified and analyzed by retrospective ("postmortem") approaches yielding data on commonly occurring consequences (and the lack thereof) for minor injury. Finally, approaches that simulate dangerous situations can identify interaction patterns that result in childhood injury. Based on such research, we are coming to view injuries as the result of patterns of behaviors that develop and persist over time, and as such these patterns can be detected and, one hopes, altered before a serious medical event occurs. The role of the pediatrician after injury occurs is clear. With regard to prevention of injuries, pediatricians' roles are being defined by those individuals who have begun to investigate causes, educate families, and advocate for regulation and prevention. However, like the causes and methods for prevention, the disciplines involved in the study and prevention of injury are multiple. Such a multidisciplinary approach that considers multiple factors, theories, models, and interventions to prevent injury may be the approach that is as simple as possible.

Adolescent↗
PubMed1992

Elephants dancing in my head: a developmental approach to children's concepts of specific pains.

The present study produced an empirically derived, developmental continuum of children's understanding of specific pains. Subjects of 5 age groups: preschool (ages 3-4), first grade (ages 6-7), third grade (ages 8-10), sixth grade (ages 11-12) and college freshmen (ages 18-23) were interviewed with open-ended questions. The subjects were questioned extensively about 3 specific types of pain: an injury (skinned knee), a medical intervention (injection), and an illness (headache). Subjects were asked to describe each pain, tell why the pain hurt, and state the value of the pain. Their answers were then categorized and the categories ordered developmentally by experts in pediatric pain who were unaware of the children's ages. Then children's specific answers were given developmental scores. Multivariate analyses revealed that older children had more complex and precise understandings of pain, and this pattern differed by type of pain and by aspect of pain being considered. The subjects were also asked to report the frequency of their own pains and their parents' pain; parental and self-reported pains were closely related.

Adolescent↗
PubMed1992

Inversion of chromosome 16 and dysplastic eosinophils in accelerated phase of chronic myeloid leukemia.

Abnormalities of chromosome 16, including inv(16)(p13q22), del(16)(q22), and t(16;16)(p13;q22), have been reported almost exclusively in association with acute myelomonocytic leukemia and are characteristically accompanied by abnormal eosinophils with dysplastic granules in the bone marrow. We observed an inv(16)(p13q22) in two patients with typical Philadelphia chromosome positive chronic myeloid leukemia (CML). The appearance of the abnormality of chromosome 16 was associated with acceleration of disease or onset of blast crisis and with the appearance in the bone marrow of abnormal eosinophils. In both cases the marrow karyotypes were 46,XY,t(9;22)(q34;q11)/46,XY,inv(16)(p13q22),t(9;22)(q34;q11). In these two patients the temporal association of the acquisition of the inversion 16 and the appearance of monocytoid cells and dysplastic eosinophils in the bone marrow further supports the relationship of this karyotypic abnormality with leukemic monocytoid and eosinophilic evolution. This secondary cytogenetic change appears to be an infrequent manifestation of specific phenotypic disease progression in CML.

Adult↗
PubMed1991

Is cyclophilin involved in the immunosuppressive and nephrotoxic mechanism of action of cyclosporin A?

In this report we have approached two questions relating to the mechanism of action of cyclosporin A (CsA). First, we address whether the major cytosolic protein for CsA, cyclophilin, is directly involved in mediating the immunosuppressive activity of this drug, and, in particular, whether inhibition of this protein's peptidyl-prolyl cis-trans isomerase (PPIase) activity results in inhibition of murine T cell activation. Second, we ask whether the nephrotoxicity observed with CsA is related to inhibition of PPIase-dependent pathways in cells other than lymphocytes. Using a series of 61 cyclosporin analogues, we generally found a good correlation between cyclophilin binding and immunosuppressive activity for the majority of analogues analyzed. However, a number of compounds of distinct structural classes were found that could interact with cyclophilin but were much less immunosuppressive than expected. The inability of these analogues to inhibit lymphocyte activation could not be explained by their failure to enter the cell and bind to cyclophilin under the conditions used in the cellular assays. Surprisingly, a nonimmunosuppressive analogue, MeAla-6, which bound well to cyclophilin and was active as a PPIase inhibitor, did not induce renal pathology in vivo. Furthermore, another analogue, MeBm2t, which was immunosuppressive in vitro, possessed little or no activity as a PPIase inhibitor. These findings pose serious questions concerning a direct role of cyclosporin in mediating CsA's immunosuppressive and nephrotoxic activities. In addition, they raise doubts about whether PPIase has a direct function in lymphocyte signal transduction.

Amino Acid Isomerases↗