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Biomedical subjects

L Peterson

Publications and source records attributed to L Peterson.

At least 19 recordsLinked to original sources
PubMed2001

Sustained multilineage gene persistence and expression in dogs transplanted with CD34(+) marrow cells transduced by RD114-pseudotype oncoretrovirus vectors.

Previous studies have shown that the choice of envelope protein (pseudotype) can have a significant effect on the efficiency of retroviral gene transfer into hematopoietic stem cells. This study used a competitive repopulation assay in the dog model to evaluate oncoretroviral vectors carrying the envelope protein of the endogenous feline virus, RD114. CD34-enriched marrow cells were divided into equal aliquots and transduced with vectors produced by the RD114-pseudotype packaging cells FLYRD (LgGLSN and LNX) or by the gibbon ape leukemia virus (GALV)-pseudotype packaging cells PG13 (LNY). A total of 5 dogs were studied. One dog died because of infection before sustained engraftment could be achieved, and monitoring was discontinued after 9 months in another animal that had very low overall gene-marking levels. The 3 remaining animals are alive with follow-ups at 11, 22, and 23 months. Analyses of gene marking frequencies in peripheral blood and marrow by polymerase chain reaction revealed no significant differences between the RD114 and GALV-pseudotype vectors. The LgGLSN vector also contained the enhanced green fluorescent protein (GFP), enabling us to monitor proviral expression by flow cytometry. Up to 10% of peripheral blood cells expressed GFP shortly after transplantation and approximately 6% after the longest follow-up of 23 months. Flow cytometric analysis of hematopoietic subpopulations showed that most of the GFP-expressing cells were granulocytes, although GFP-positive lymphocytes and monocytes were also detected. In summary, these results show that RD114-pseudotype oncoretroviral vectors are able to transduce hematopoietic long-term repopulating cells and, thus, may be useful for human stem cell gene therapy.

Amino Acid Transport System ASC↗
PubMed2001

Health economics benefits following autologous chondrocyte transplantation for patients with focal chondral lesions of the knee.

Autologous chondrocyte transplantation (ACT) for the treatment of cartilage injuries has been in clinical use for several years. Since this new technique is potentially more costly and invasive than traditional conservative therapies, we evaluated the effect of ACT on clinical outcome, absenteeism, disability status, and total direct economic burden in 57 patients with full-thickness chondral lesions of the knee treated between 1987 and 1996. Patients graded good or excellent following ACT in the treatments groups were: femoral condyles (28/33), femoral condyles with anterior cruciate ligament (ACL) repair (5/5), osteochondritis dissecans (7/8), and patellar lesions (9/11). Pre-ACT, 57/57 patients were disabled and post-ACT (mean follow-up 7.3 years) 44/57 had no sickness, 10/57 had minor disability, and 1/57 was disabled. Two of the 57 patients suffered re-injury during the follow-up time. In the 10-year period prior to ACT, the average cost of absenteeism and surgery was SEK 982,457 ($ 122,807) and SEK 47,000 ($ 5,875), respectively, compared to the post-ACT period where both absenteeism and medical costs were dramatically reduced: SEK 9,508 ($ 1,189) and SEK 7,050 ($ 881), respectively. In conclusion, 49 of the 57 patients improved clinically as a result of the ACT treatment. A dramatic cost-saving effect was demonstrated over a projected 10-year period due to reduced absenteeism and disability.

Absenteeism↗
PubMed2001

Follicular dendritic cell tumor presenting in the lung: a case report.

An example of extranodal follicular dendritic cell sarcoma (FDCS) presenting in the lung, a heretofore unreported site, is described. Macroscopically, a 9.5-cm, tan-white, dominant mass and multiple smaller parenchymal and pleural nodules were identified. Microscopically, the tumor was composed of spindled cells with uniform cytologic features arranged in short, intersecting fascicles and intermixed small lymphocytes and plasma cells. One of 4 peribronchial and hilar lymph nodes evaluated microscopically was focally involved by the process. Immunohistochemically, the neoplastic spindled cells expressed complement receptors CD21 and CD35 and low-affinity nerve growth factor receptor but did not express keratin (AE1/AE3 and CAM5.2), CD45 (leukocyte common antigen), CD20 (L26), S-100 protein, muscle-specific actin, or gp100 protein (HMB45). Ultrastructurally, the tumor cells have complex interdigitating cell surface processes and desmosomes. Epstein-Barr virus (EBV) was not detected in the tumor cells by in situ hybridization for EBV-encoded RNA or by polymerase chain reaction for viral DNA. FDCS should be considered in the differential diagnosis of any spindled-cell tumor with interspersed chronic inflammatory cells occurring in the lung. An immunohistochemical panel, including anti-CD21 and -CD35, can assist in its diagnosis, especially with small bronchial biopsy specimens. 2001 by W.B. Saunders Company.

Adult↗
PubMed2001

Compliance with fecal occult blood test screening among low-income medical outpatients: a randomized controlled trial using a videotaped intervention.

BACKGROUND: Morbidity and mortality from colorectal cancer (CRC) are heightened among the socioeconomically disadvantaged. METHOD: A randomized controlled trial was conducted to evaluate the efficacy of a videotaped intervention using peer educators as well as a health professional to increase compliance with fecal occult blood test (FOBT) screening. Participants were 160 older individuals attending a medical outpatient clinic. Compliance with FOBT use was the dependent measure. Demographic variables, family history of CRC, viewing the videotape, perceived risk, self-efficacy, physician recommendation, knowledge about CRC screening, and intent to use the FOBT were independent measures. RESULTS: Approximately 41% of participants complied with FOBT screening. Significant relationships were found between intent and family history of CRC, viewing the video, perceived risk, self-efficacy, and CRC knowledge. However, none of these variables was significantly related to compliance with FOBT use. CONCLUSIONS: Although modest compliance rates were shown for both experimental and control groups, their compliance did not differ significantly. Further investigation of the impact of a video as part of an enhanced intervention program should be considered.

Analysis of Variance↗
PubMed2001

Autologous chondrocytes used for articular cartilage repair: an update.

Articular cartilage in adults has a poor ability to self-repair after a substantial injury; however, it is not known whether there is a cartilage resurfacing technique superior to the existing techniques. It is not satisfactory that at the beginning of the new millennium, there still is a lack of randomized studies comparing different cartilage repair techniques and there still is little knowledge of the natural course of a cartilaginous lesion. To date, various articular cartilage resurfacing techniques have the potential to improve the repair of cartilage defects and reduce the patient's disability. One such cartilage repair technique is autologous chondrocyte transplantation combined with a periosteal graft. Since the first patient was operated on in 1987, much interest in cartilage repair and cell engineering has emerged. The experience with autologous chondrocyte transplantation during the past 13 years with in vitro chondrocyte expansion, cartilage harvest, and postoperative biopsy technique is discussed, and the latest followup of 213 consecutive patients in different subgroups with 2 to 10 years followup is presented. The technique gives stable long-term results with a high percentage of good to excellent results (84%-90%) in patients with different types of single femoral condyle lesions, whereas patients with other types of lesions have a lower degree of success (mean, 74%).

Adult↗
PubMed2001

Maternal use of baby walkers with young children: recent trends and possible alternatives.

OBJECTIVES: To examine recent trends in baby walker and exersaucer use, and to assess maternal motivations for choosing to use or not use these devices with children. SETTING: Small, Midwestern city in the United States. METHODS: Retrospective telephone survey with a sample of 329 mothers who provided information about their use of walkers and exersaucers with 463 children born in Columbia, Missouri between January 1994 and April 1999. RESULTS: Baby walker use in the sample declined fairly steadily from 1994 to 1999, whereas exersaucer use increased during the same period. Altogether 88% of mothers were aware of the injury risks associated with walkers, and this knowledge was the most commonly reported reason for abstaining from walker use. Remarkably, 38% of participants with knowledge of walker risks nevertheless used these devices. Participants reported many reasons for using walkers and exersaucers, including child entertainment, perceived developmental benefit, easy availability, and improved safety of exersaucers. CONCLUSIONS: Public knowledge of the hazards of walkers seems to be high, and this awareness is a likely factor in many caregivers' decisions not to use them. Future interventions should focus particular attention on those caregivers who continue to use walkers despite knowledge of the associated risks. In addition to persuasive interventions, alternatives to walkers should be encouraged. Exersaucers represent one viable alternative, and should be promoted as such by the media, pediatricians, and other child care professionals.

Chi-Square Distribution↗
PubMed2001

Simvastatin has anti-inflammatory and antiatherosclerotic activities independent of plasma cholesterol lowering.

Inhibitors of 3-hydroxy-3-methyl-glutaryl-CoA (HMG-CoA) reductase, such as simvastatin, lower circulating cholesterol levels and prevent myocardial infarction. Several studies have shown an unexpected effect of HMG-CoA reductase inhibitors on inflammation. Here, we confirm that simvastatin is anti-inflammatory by using a classic model of inflammation: carrageenan-induced foot pad edema. Simvastatin administered orally to mice 1 hour before carrageenan injection significantly reduced the extent of edema. Simvastatin was comparable to indomethacin in this model. To determine whether the anti-inflammatory activity of simvastatin might affect atherogenesis, simvastatin was tested in mice deficient in apoE. Mice were dosed daily for 6 weeks with simvastatin (100 mg/kg body wt). Simvastatin did not alter plasma lipids. Atherosclerosis was quantified through the measurement of aortic cholesterol content. Aortas from control mice (n=20) contained 56+/-4 nmol total cholesterol/mg wet wt tissue, 38+/-2 nmol free cholesterol/mg, and 17+/-2 nmol cholesteryl ester/mg. Simvastatin (n=22) significantly (P<0.02) decreased these 3 parameters by 23%, 19%, and 34%, respectively. Histology of the atherosclerotic lesions showed that simvastatin did not dramatically alter lesion morphology. These data support the hypothesis that simvastatin has antiatherosclerotic activity beyond its plasma cholesterol-lowering activity.

Administration, Oral↗
PubMed2001

Decreasing children's risk taking on the playground.

Playground mishaps are some of the most common sources of injury and are the leading killer of children. The present study used a multiple baseline design across three classrooms (N = 379 children). With minimal teaching and rewards, children decreased and maintained decreased risky playground behaviors on slides. Floor effects on climbers prevented the demonstration of similar effects. The decreases seen in risky slide behavior are discussed within the context of preventive safety training for playground injuries.

Child↗
PubMed2000

Expansions of clonal and oligoclonal T cells in B-cell chronic lymphocytic leukemia are primarily restricted to the CD3(+)CD8(+) T-cell population.

B-cell chronic lymphocytic leukemia (B-CLL) is characterized by the accumulation of mature-appearing clonal B cells exhibiting coexpression of CD5 and CD23. In addition to the accumulation of neoplastic B cells, numerous T-cell abnormalities also occur in B-CLL patients. In this study, the presence, and distribution within the T-cell subsets, of clonal/oligoclonal T cells was studied. Multicolor flow cytometric techniques were employed using combinations of anti-CD3, anti-CD4, and anti-CD8 antibodies coupled with antibodies specific for V(alpha) and V(beta) T-cell receptor (TCR) epitopes. Molecular studies of TCR gene sequences were done to confirm the presence of clonal/oligoclonal T-cell populations. In the flow cytometric studies, examination of V(alpha)/V(beta)expression found evidence of clonal/oligoclonal expansion in 9 of 19 patients studied. In eight of the nine patients, the expansions were restricted to the CD3(+)CD8(+) cell population. Molecular analyses were performed in 16 patients, 12 of whom showed a clonal or oligoclonal pattern. Of the four patients who were negative in the molecular analyses, all demonstrated flow cytometric evidence of clonal/oligoclonal expansions. Thus, when the flow cytometric and molecular analyses were considered together, all 16 patients for whom parallel analyses were done showed evidence of clonal/oligoclonal expansions. These results confirm previous work demonstrating that the majority of B-CLL patients harbor clonal/oligoclonal expansions within the T-cell population. Additionally, based on the relative numbers of cells expressing specific V(alpha) or V(beta)epitopes, these results show that these expansions occur primarily within the CD3(+)CD8(+) T-cell population.

Aged↗
PubMed2000

Linking childhood sexual abuse and abusive parenting: the mediating role of maternal anger.

OBJECTIVE: This study had two primary objectives: First, to examine the association between childhood sexual abuse (CSA) and later parenting characteristics, particularly physical abuse potential, and second, to explore maternal anger as a mediator of the relationship between CSA and adult physical abuse potential. METHOD: Utilized a community sample of low SES participants that included 138 mothers classified as having experienced CSA, and a comparison group of 152 non-sexually abused mothers. Parenting variables examined included the mothers' physical abuse potential, nurturance toward their children, unrealistic developmental expectations of children, as well as frequencies of spanking and general punishment. Data was collected via interview and other self-report measures. RESULTS: Even after controlling for mothers' childhood experience of Physical abuse, CSA significantly predicted adult risk of physically abusing one's own children. Further, maternal anger was confirmed as a mediator of the relationship between having been sexually abused as a child and the potential for physically abusing one's own children. CONCLUSIONS: CSA may be a risk factor for subsequent physically abusive parenting, while anger appears to play a significant role in mediating this relationship. Findings are discussed in the context of current knowledge concerning the impact of child sexual abuse and the processes contributing to abusive parenting.

Adult↗
PubMed2000

Two- to 9-year outcome after autologous chondrocyte transplantation of the knee.

Autologous cultured chondrocyte transplantation was introduced in Sweden in 1987 for the treatment of large (1.5-12.0 cm2) full thickness chondral defects of the knee. The clinical, arthroscopic, and histologic results from the first 101 patients treated using this technique are reported in this study. Patients were assessed retrospectively using three types of endpoints: patient and physician derived clinical rating scales (five validated and two new); arthroscopic assessment of cartilage fill, integration, and surface hardness; and standard histochemical techniques. Ninety-four patients with 2- to 9-years followup were evaluable. Good to excellent clinical results were seen in individual groups as follows: isolated femoral condyle (92%), multiple lesions (67%), osteochondritis dissecans (89%), patella (65%), and femoral condyle with anterior cruciate ligament repair (75%). Arthroscopic findings in 53 evaluated patients showed good repair tissue fill, good adherence to underlying bone, seamless integration with adjacent cartilage, and hardness close to that of the adjacent tissue. Hypertrophic response of the periosteum or graft or both was identified in 26 arthroscopies; seven were symptomatic and resolved after arthroscopic trimming. Graft failure occurred in seven (four of the first 23 and three of the next 78) patients. Histologic analysis of 37 biopsy specimens showed a correlation between hyalinelike tissue (hyaline matrix staining positive for Type II collagen and lacking a fibrous component) and good to excellent clinical results. The good clinical outcomes of autologous chondrocyte transplantation in this study are encouraging, and clinical trials are being done to assess the outcomes versus traditional fibrocartilage repair techniques.

Activities of Daily Living↗
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↗