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Biomedical subjects

L Peterson

Publications and source records attributed to L Peterson.

At least 37 records · Page 2Linked to original sources
PubMed2000

Psychological and sport-specific characteristics of football players.

It is hypothesized that players of different levels of play might differ not only in their football skills but also in their way of playing football and with respect to psychological factors such as concentration, reaction time, or competitive anxiety. The psychological characteristics of a player might influence his way of playing football (in particular with respect to fair play) and also his risk of injury. A group of 588 football players were studied by questionnaire; additionally, reaction time tests were performed. Psychological characteristics were assessed by three established self-evaluation questionnaires: the Athletic Coping Skills Inventory, the State Competitive Anxiety Test, and the State-Trait-Anger-Expression-Inventory. Football-specific characteristics that were investigated included playing experience and positions played, style of play, number of training hours and games, as well as aspects of fair play. Reaction time was tested twice: without the influence of physical exercise and immediately after a 12-minute run. A significant reduction in reaction time was observed after physical exercise. In high-level players, the reaction time immediately after the 12-minute run was significantly shorter than it was in low-level players. The questionnaire answers given regarding fair play clearly indicated that fair play is not paid sufficient respect. The relationship between psychological characteristics and attitudes toward fair play was analyzed and discussed.

Adolescent↗
PubMed2000

Incidence of football injuries and complaints in different age groups and skill-level groups.

In this study, the incidence of football injuries and complaints as related to different age groups and skill levels was studied over the period of 1 year. All injuries and complaints as well as the amount of time players spent in training and games were recorded. All injured players were examined weekly by physicians, and all injuries were assessed according to the International Classification of Diseases (ICD-10), which describes them in terms of injury type and location, the treatment required, and the duration of subsequent performance limitations. A total of 264 players of different age groups and skill levels was observed for 1 year. Five hundred fifty-eight injuries were documented. Two hundred sixteen players had one or more injuries. Only 48 players (18%) had no injury. The average number of injuries per player per year was 2.1. Injuries were classified as mild (52%), moderate (33%), or severe (15%). Almost 50% of all injuries were contact injuries; half of all the contact injuries were associated with foul play. The majority of injuries were strains and sprains involving the ankle, knee, and lumbar spine. Nearly all players (91%) suffered from complaints related to football. Only 23 players reported no injuries and no complaints. Prevention programs, fair play, and continuing education in techniques and skills may reduce the incidence of injuries over time.

Adolescent↗
PubMed2000

Severe injuries in football players. Influencing factors.

The aims of this prospective study were to analyze factors related to the occurrence of severe football injuries in players of different ages (14 to 42 years) and different skill levels (local teams to first league teams). In the Czech Republic, 398 players were followed up for 1 year, during which time they sustained 686 injuries. Of these, 113 (16.5%) were severe injuries. Ninety-seven severe injuries (86%) were able to be documented in detail. Trauma was the cause of 81.5% of the injuries and overuse was the cause of 18.5%. Joint sprains predominated (30%), followed by fractures (16%), muscle strains (15%), ligament ruptures (12%), meniscal tears and contusions (8%), and other injuries. Injuries to the knee were most prevalent (29%), followed by injuries to the ankle (19%) and spine (9%). More injuries occurred during games (59%) than in practice. Twenty-four percent of the injured players had suffered a previous injury of the same body part. Forty-six percent of injuries were caused by contact and 54% involved no body contact. Thirty-one percent of severe injuries were caused by foul play. From these results and the analysis of injuries in specific body parts, the following factors were determined to influence the occurrence of severe injuries: 1) personal factors (intrinsic): age of player, previous injuries, joint instability, abnormality of the spine, poor physical condition, poor football skills, or inadequate treatment and rehabilitation of injuries; 2) environmental factors (extrinsic): subjective exercise overload during practices and games, amount and quality of training, playing field conditions, equipment (wearing of shin guards and taping) and violations of existing rules (foul play).

Adolescent↗
PubMed2000

Risk factor analysis for injuries in football players. Possibilities for a prevention program.

Review of the literature shows that information concerning risk factors for football injuries is incomplete and partly contradictory. The aim of this study was to analyze the influence of medical history, physical findings, football skills, and football performance, as well as psychosocial characteristics on the occurrence and severity of football injuries. The prospective outline of the study was as follows: after a baseline examination was performed to ascertain possible predictors of injury, all players were followed up weekly for 1 year to register subsequent injuries and complaints. Two hundred sixty-four of 398 players (67%) had complete weekly follow-ups over 1 year. A majority of the players (N = 216; 82%) were injured during the observation period. In comparing injured and uninjured players, several differences were observed. To create a multidimensional predictor score for football injuries, 17 risk factors were selected. These risk factors covered a wide spectrum, such as previous injuries, acute complaints, inadequate rehabilitation, poor health awareness, high life-event stress, playing characteristics, poor reaction time, poor endurance, and insufficient preparation for games. By summing up the individual risk factors, a predictive sum was calculated for each player. The more risk factors present at the baseline examination, the higher the probability of that player incurring an injury in the ensuing year. Using two risk factors as the cut-off score, more than 80% of the players were correctly classified as to whether they went on to incur an injury. Based on these findings, knowledge from the literature, and practical experience, possibilities for a prevention program are suggested.

Adolescent↗
PubMed2000

Medical history and physical findings in football players of different ages and skill levels.

The physical and physiologic demands of football on its participants become more pronounced as the level of competition increases. The aim of this study was to compare the medical history and physical findings in players from different levels of play as well as to analyze the relationship between pathologic findings in the joints of the lower extremities and the medical history. Five hundred eighty-eight football players from eight age and skill levels were investigated. The medical histories of the players were obtained by questionnaire. A physical examination conducted by specially trained physicians incorporated anthropometric and body fat measurements and examination of the spine and the hip, knee, foot, and great toe joints. On average, the players reported 6.6 (SD, 8.8) previous injuries. At the time of the examination, 136 players (24%) still felt the effects of a previous injury. Almost one-quarter of the players (134, 23%) had a pathologic finding in either the right or left knee, and even more players (162, 28%) had a pathologic anterior drawer sign either in the right or left ankle. A correlation was found between the location of the pathologic findings and the preferred leg for playing football. We recommend that further research should address the prevalence of pathologic findings and complaints in football players as well as the secondary structural changes that may occur as the result of playing football.

Adolescent↗
PubMed1999

Countering bullying at an australian secondary school with students as helpers.

To counter bullying at an Australian coeducational secondary school, staff and students co-operated in developing and implementing appropriate policies and procedures. Questionnaires assessing the incidence of bullying and related attitudes were completed by students in Years 7, 9, 10 and 11 in 1995 and again in 1997. Significant reductions in levels of victimization were recorded for Year 7 students only. Significantly increased support for anti-bullying initiatives was found among senior students (Years 10 and 11). Anti-bullying activities directed and undertaken by students themselves received most approval from peers.

Adolescent↗
PubMed1999

Does long-term finasteride therapy affect the histologic features of benign prostatic tissue and prostate cancer on needle biopsy? PLESS Study Group. Proscar Long-Term Efficacy and Safety Study.

OBJECTIVES: Finasteride, a common agent used to treat benign prostatic hyperplasia (BPH), inhibits 5-alpha-reductase. Testosterone is converted by 5-alpha-reductase to the more potent dihydrotestosterone, which is the primary androgen in the prostate. Leuprolide is a stronger antiandrogen that is used to downstage prostate cancer before radical prostatectomy. Leuprolide induces marked atrophy of prostate carcinoma cells, which sometimes makes pathologic diagnosis of cancer difficult, although evaluation at radical prostatectomy is easier than at biopsy. It is unknown whether finasteride produces similar changes, which would result in greater diagnostic difficulty because such changes would be seen on biopsy to rule out cancer in men with suspicious clinical findings treated for BPH. The current study investigated the histologic effects of finasteride therapy on human prostate cancer and benign prostatic tissue on needle biopsy. METHODS: In blinded manner, we reviewed 53 needle biopsy specimens showing prostate carcinoma (35 treated with finasteride, 18 with placebo). Also reviewed in blinded manner were 50 benign needle biopsy specimens (25 treated with finasteride, 25 with placebo). The Gleason score, number of cores involved, percentage cancer involvement in a core, percentage of atrophic changes in cancer cells, presence of mitoses, blue-tinged mucinous secretions, prominent nucleoli, and high-grade prostatic intraepithelial neoplasia were documented for each case in the cancer group. The percentage of atrophy, basal cell hyperplasia, transitional metaplasia, chronic inflammation, and stromal proliferation was documented for each case in the benign group. RESULTS: No significant histologic differences were present in either the benign or cancer group between cases treated with finasteride and placebo. CONCLUSIONS: We conclude that finasteride treatment for BPH does not cause difficulty in the diagnosis of cancer in prostate needle specimens. It is possible that there are severely atrophic areas resulting from finasteride treatment that are undersampled. However, the conclusion that cancer seen on needle biopsy in men treated with finasteride is unaltered and readily identified as cancer remains valid.

Aged↗
PubMed1999

Prevention of childhood injury: clinical and public policy challenges.

Injuries are the leading killer of children in the United States, at a rate significantly higher than in other industrialized countries. In this article, we outline how a behaviorally and developmentally based model of prevention may assist in determining effective interventions for various injury risks. Two conclusions emerge: (a) the strength of perceived costs and consequences for taking effective safety actions greatly influences the probability that they will be implemented; and (b) intervening at the most developmentally appropriate time is likely to result in more effective outcomes. Further, clinical psychologists are uniquely suited to assess contingencies that maintain unsafe practices, but we need to enlist the participation of citizens and other professionals to mount persuasive intervention campaigns. Despite strong demonstration projects, childhood injury reduction has lagged behind other public health endeavors. Obstacles to injury prevention include (a) the diffusion of injury threats, complicating the identification of effective targets for intervention; (b) the tendency of parents and even some health professionals to regard injuries as products of fate, which fosters complacency; (c) the failure of U.S. social service policy to support preventive strategies; and (d) an American cultural tradition of opposing regulation. Suggestions for improved public policy and intervention procedures are advanced.

Caregivers↗
PubMed1999

Advanced techniques in autologous chondrocyte transplantation.

Autologous chondrocyte transplantation (ACT) provides durable hyaline repair tissue in correctly selected patients; it is indicated for full thickness, weightbearing condyle injuries, and injuries to the trochlea of the femur. ACT results in reproducibly satisfactory results, with return to high level activities, including sports, in over 90% of these patients. Second look arthroscopies demonstrate macroscopic integrity of the grafts; and biopsies demonstrate hyaline cartilage repair, which is critical, as shown clinically, to giving durable results at two to nine years follow-up. Also discussed in this article is surgical technique which is especially important for complex reconstructions. As technical refinements and rehabilitation protocols improve, results for treating patellar and tibial injuries may improve; at this time, the response to treating bipolar focal chondral injuries is unknown and not recommended.

Arthroscopy↗
PubMed1999

Of needles and skinned knees: children's coping with medical procedures and minor injuries for self and other.

Children participated in four role-plays designed to assess what the children themselves would do and what they would suggest a friend should do when encountering a medical procedure and a minor injury. Open-ended responses were coded into an empirically derived continuum suggested by past research. Similar responses were given to cope with medical procedures and injuries. However, children suggested more reactive coping strategies (e.g., cry, pull away) for themselves and more proactive responses (e.g., think of something fun, take deep breaths) for friends. This finding questions the assumption that children choose the most effective coping strategy in their repertoire when they themselves confront an aversive stimulus, suggesting that preparation for invasive procedures should include motivational components.

Adaptation, Psychological↗
PubMed1999

Cytomegalovirus-infected cells in routinely prepared peripheral blood films of immunosuppressed patients.

We describe 4 patients identified over 5 years with large atypical cells on the feathered edge of routinely prepared peripheral blood films. Films were reviewed either as part of a blood film consultation or a bone marrow examination. The cells were 50 to 60 microns in diameter, with granular eosinophilic cytoplasmic inclusions and eccentric enlarged nuclei. Additional studies including buffy coat preparations and immunohistochemistry revealed that these were circulating cytomegalovirus (CMV)-infected cells, most likely of endothelial origin. All patients were immunocompromised (3 had HIV infection, and 1 was an organ transplant recipient) and had clinical evidence of CMV infection. The unique appearance of these cells at Wright-Giemsa staining, and their possible misidentification as malignant cells or other cells, highlights the need for pathologists to be aware of their morphologic features and possible clinical implication.

Adult↗
PubMed1999

Importance of developmental theory and investigation to research in clinical child psychology.

Focuses on the developmental periods of infancy, childhood, and adolescence to offer illustrations of the advantages of using developmental theory and research to establish targets for research on intervention, assessment and treatment planning, and evaluation of effective strategies for prevention of childhood and later adult disorders. The importance for training clinical graduate students in developmental approaches to research is stressed, and hopes for a future of mutual contributions of developmental and clinical psychology are expressed in light of the fact that, after a troubled history of isolation from one another and even active denigration of one another's goals and methods, developmental and clinical psychology are exhibiting joint recognition of the advantages of collaborative research.

Adult↗
PubMed1998

Improved gene transfer into baboon marrow repopulating cells using recombinant human fibronectin fragment CH-296 in combination with interleukin-6, stem cell factor, FLT-3 ligand, and megakaryocyte growth and development factor.

We have used a competitive repopulation assay in baboons to develop improved methods for hematopoietic stem cell transduction and have previously shown increased gene transfer into baboon marrow repopulating cells using a gibbon ape leukemia virus (GALV)-pseudotype retroviral vector (Kiem et al, Blood 90:4638, 1997). In this study using GALV-pseudotype vectors, we examined additional variables that have been reported to increase gene transfer into hematopoietic progenitor cells in culture for their ability to increase gene transfer into baboon hematopoietic repopulating cells. Baboon marrow was harvested after in vivo administration (priming) of stem cell factor (SCF) and granulocyte colony-stimulating factor (G-CSF). CD34-enriched marrow cells were divided into two equal fractions to directly compare transduction efficiencies under different gene transfer conditions. Transduction by either incubation with retroviral vectors on CH-296-coated flasks or by cocultivation on vector-producing cells was studied in five animals; in one animal, transduction on CH-296 was compared with transduction on bovine serum albumin (BSA)-coated flasks. The highest level of gene transfer was obtained after 24 hours of prestimulation followed by 48 hours of incubation on CH-296 in vector-containing medium in the presence of multiple hematopoietic growth factors (interleukin-6, stem cell factor, FLT-3 ligand, and megakaryocyte growth and development factor). Using these conditions, up to 20% of peripheral blood and marrow cells contained vector sequences for more than 20 weeks, as determined by both polymerase chain reaction and Southern blot analysis. Gene transfer rates were higher for cells transduced on CH-296 as compared with BSA or cocultivation. In one animal, we have used a vector expressing a cell surface protein (human placental alkaline phosphatase) and have detected 10% and 5% of peripheral blood cells expressing the transduced gene 2 and 4 weeks after transplantation as measured by flow cytometry. In conclusion, the conditions described here have resulted in gene transfer rates that will allow detection of transduced cells by flow cytometry to facilitate the evaluation of gene expression. The levels of gene transfer obtained with these conditions suggest the potential for therapeutic efficacy in diseases affecting the hematopoietic system.

Animals↗
PubMed1998

The MHC class I binding proteins LIR-1 and LIR-2 inhibit Fc receptor-mediated signaling in monocytes.

The MHC class I binding proteins leukocyte immunoglobulin-like receptor (LIR)-1 and -2 recognize a similar broad spectrum of HLA-A, -B and -C alleles but are differentially expressed in lymphocytes, monocytes, and dendritic cells. In monocytes, phosphorylation of LIR-1 and LIR-2 results in the binding of the tyrosine phosphatase SHP-1. Coligation of either LIR with Fcgamma receptor I (CD64) inhibits tyrosine phosphorylation of the associated Fc receptor gamma chain and Syk molecules, as well as intracellular calcium mobilization. These findings suggest that LIR-1 and LIR-2 function as unique MHC class I receptors involved in the inhibition or down-modulation of monocyte activation signals, particularly those mediated through the receptors for IgG, IgE and IgA.

Alleles↗
PubMed1998

School-age children's attributions about their own naturally occurring minor injuries: a process analysis.

OBJECTIVE: To analyze children's attribution of cause regarding their naturally occurring minor injuries in light of the pre-injury parental acceptability of children's behavior and the emotions children experienced immediately after the event. METHOD: Sixty-one 8-year-old children were interviewed biweekly for one year about their naturally occurring minor injuries. Participants monitored environmental and psychosocial elements of the injuries and later answered questions about the cause of the event. RESULTS: For a total sample of 1,037 minor injuries, children most frequently designated fate as the primary cause. Further analysis revealed that attributions varied by children's pre-injury behavior and post-injury feelings. Children were equally likely to accept primary responsibility or to assign cause to fate when they were engaged in unacceptable behavior before the event. Similarly, children assumed primary responsibility for the injury when they experienced post-injury guilt. No differences in injury attributions were revealed by gender or by the child's frequency of injuries during the year. CONCLUSIONS: Results highlight the significance of adult caregiver safety rule creation, endorsement, and ongoing communication for the socialization of children's safe behaviors.

Adult↗