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Biomedical subjects

L M Olson

Publications and source records attributed to L M Olson.

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

Motor vehicle crash characteristics and medical outcomes among older drivers in Utah, 1992-1995.

STUDY OBJECTIVE: We sought to compare the characteristics and medical outcomes of motor vehicle crashes for drivers 70 years and older with those of drivers between the ages of 30 and 39 years. METHODS: We probabilistically linked statewide motor vehicle crash and hospital discharge data between the years of 1992 and 1995 for the state of Utah. We calculated the odds of older drivers exhibiting certain motor vehicle crash characteristics compared with younger drivers. Adjusting for nighttime crash, high-speed crash, and seatbelt use, we calculated the odds of an older driver being killed or hospitalized compared with those of a younger driver. RESULTS: During the study years, there were 14,466 drivers older than 69 years and 68,706 drivers between the ages of 30 and 39 years involved in motor vehicle crashes in Utah. Older drivers were less likely to have crashes involving drug or alcohol use (odds ratio [OR] 0.1; 95% confidence interval [CI] 0.1 to 0.2) and less likely to have crashes at high speed (OR 0.6; 95% CI 0.6 to 0.7). Although older drivers were no more likely to have a crash involving a right-hand turn (OR 1.0; 95% CI 0.9 to 1.1) than younger drivers, they were over twice as likely to have a crash involving a left-hand turn (OR 2.3; 95% CI 2.2 to 2.5). Also, older drivers were more likely to be killed or hospitalized than younger drivers (OR, 3.5; P <.001). Among belted drivers, an older driver was nearly 7 times more likely to be killed or hospitalized than a younger driver (OR 6. 9; 95% CI 5.4 to 8.9). CONCLUSION: Older drivers do have distinctive motor vehicle crash patterns. Interventions must be taken to reduce the number of left-hand turn crashes involving older drivers. In addition, further research is needed to design, implement, and evaluate countermeasures that may enable older drivers to continue driving while keeping public safety in the forefront.

Accidents, Traffic↗
PubMed1999

Abnormal estrous cyclicity after disruption of endothelial and inducible nitric oxide synthase in mice.

The roles of nitric oxide (NO) and nitric oxide synthase (NOS) in reproduction were studied by examining the estrous cycle of wild-type (WT) mice, inducible NOS (iNOS)-, and endothelial NOS (eNOS)-knockout mice. We observed an average estrous cycle of 4.8 +/- 0.2 days in WT mice. While we observed no significant influence of iNOS deficiency on cycle length, eNOS-knockout females showed a significantly longer estrous cycle (6.6 +/- 0.6 days; p < 0.03) than WT females, due to an extension of diestrus (p < 0.03). There was no influence of iNOS deficiency on ovulation rate compared with that in WT females; however, eNOS-knockout mice showed a significant reduction (p < 0.05) in ovulatory efficiency relative to WT or iNOS-knockout females. In contrast to WT females, in which the highest level of estradiol (E2) was observed at 1500 h of proestrus, iNOS-knockout females reached a peak of E2 at 1830 h of proestrus. In eNOS-knockout females, the peak of E2 occurred at 1830 h, as in iNOS-knockout mice; however, E2 levels were 5-fold and 3-fold higher (p < 0.05) than levels observed in WT and iNOS-knockout females, respectively. There was no effect of genotype on the plasma LH concentrations at proestrus. On the first day of diestrus, eNOS-knockout females showed significantly higher plasma E2 and progesterone levels (p < 0.05) relative to WT and iNOS-knockout females. The dysfunction in cyclicity, ovulation rate, ovarian morphology, and steroidogenesis in eNOS-knockout female mice strongly supports the concept that eNOS/NO plays critical roles in ovulation and follicular development.

Animals↗
PubMed1999

Disturbing trends: the epidemiology of pediatric emergency medical services use.

OBJECTIVE: To compare pediatric ambulance patients transported for chief complaints of suicide, assault, alcohol, and drug intoxication (SAAD) with pediatric patients transported for all other chief complaints. METHODS: An out-of-hospital database for the primary transporting service in an urban area was analyzed for patients 0-20 years of age from 1992 to 1995. Chief complaints by age, gender, and billing status were analyzed. RESULTS: There were 17,722 transports. The SAAD group comprised 14.9% of all transports (suicide attempt 1.6%, assault 5.9%, alcohol intoxication 3.2%, and drug abuse 4.2%). The proportion of transports due to SAAD increased with age: 0-11-year-olds (4.2%); 11-16-year-olds (17.5%); and 17-20-year-olds (20.3%) (p = 0.0001). Genders were equally represented in the overall group, while males comprised 52.6% of the SAAD transports (p = 0.032). In the SAAD group, the majority of transports for assaults (55.9%) and alcohol (58.8%) involved males, while females were the majority in transports for suicide (52.3%) and drug abuse (66%) (p = 0.0001). Reimbursement sources differed, with those in the SAAD group less likely to be reimbursed by private or public (Medicaid, government) insurance (p < 0.0001) compared with the overall group. CONCLUSIONS: A substantial proportion of pediatric emergency medical services transports are for high-risk conditions. This patient population differs from the overall group by age distribution and reimbursement source.

Adolescent↗
PubMed1999

Reliability and validity of the Children's Health Survey for Asthma.

OBJECTIVE: Describe the psychometric properties of the Children's Health Survey for Asthma (CHSA)- a condition-specific, self-report, functional health measure for parents of children 5 to 12 years of age with chronic asthma. METHOD: Data from two cross-sectional and one longitudinal study were used to assess internal consistency reliability, test-retest reliability, and validity of the CHSA. Over 275 parents and guardians of children with asthma completed the CHSA in one of three studies. The combined samples included a heterogenous mix of respondents by child age and race/ethnicity and parental marital and socioeconomic status. Five domain scores were computed: physical health, activity (child), activity (family), emotional health (child), and emotional health (family). Raw scale scores were transformed from 0 to 100 with higher scores indicating better or more positive outcomes. RESULTS: Across the three samples, mean scale scores ranged from a low of 61.5 (emotional health of the child) to a high of 86.1 (activity [family]). Internal consistency reliability for each of the scales was high (Cronbach's alpha =.81-. 92), and test-retest reliability (correlation between forms) ranged from.62 to.86. Significant differences in mean scores for four of five scales were noted between those with low versus moderate to high recent symptom activity. CONCLUSION: In three tests, the CHSA displays strong reliability and validity. Descriptive statistics demonstrate a range of scale scores. Internal consistency is good to excellent and short-term test-retest reliability is good for each of the five scales. Construct validity is demonstrated by the ability of CHSA to distinguish levels of disease severity, defined by symptom activity.

Asthma↗
PubMed1998

Opposing actions of prostaglandins and oxytocin determine the onset of murine labor.

Prostaglandins (PGs) have been recently proven essential for parturition in mice. To dissect the contributions of the two cyclooxygenase (COX) isoforms to the synthesis of PGs during pregnancy, we have characterized the parturition phenotype of COX-1-deficient mice. We find that mice with targeted disruption of the COX-1 gene have delayed parturition resulting in neonatal death. Results of matings of COX-1-deficient females with COX-1 intact males, and blastocyst transfer of COX-1-deficient or -intact embryos into wild-type foster mothers, proved necessity and sufficiency of maternal COX-1 for the normal onset of labor. COX-1 expression is induced in gravid murine uterus and by in situ hybridization; this induction is localized to the decidua. Measurement of uterine PGs further confirmed that COX-1 accounted for the majority of PGF2alpha production. To evaluate the interaction of PGs with oxytocin during murine labor, we generated mice deficient in both oxytocin and COX-1. Surprisingly, the combined oxytocin and COX-1-deficient mice initiated labor at the normal time. COX-1-deficient mice demonstrated impaired luteolysis, as evidenced by elevated serum progesterone concentration and ovarian histology late in gestation, and delayed induction of uterine oxytocin receptors. In contrast, simultaneous oxytocin and COX-1 deficiency restored the normal onset of labor by allowing luteolysis in the absence of elevated PGF2alpha production. These findings demonstrate that COX-1 is essential for normal labor in the mouse, with a critical function being to overcome the luteotrophic action of oxytocin in late gestation.

Animals↗
PubMed1998

The murine tub (rd5) mutation is not associated with a primary axonemal defect.

Some genetic syndromes causing loss of hearing and vision, such as some forms of Usher's syndrome, also cause reduced sperm cell motility, bronchiectasis, and other pathologies involving cilia- and flagella-bearing cells. In some Usher's patients, ultrastructural defects of axonemes within photoreceptor ciliary bridges, nasal cilia, and sperm cell flagella have been found, indicating a primary defect of axonemal conformation. Mice homozygous for the tub (rd5) mutation exhibit progressive retinal degeneration, sensorineural hearing loss, reduced fertility, and obesity, and presently represent the only animal model with neuroepithelial degeneration of both cochlea and retina without other neurological abnormalities. They provide a good phenotypic match to human genetic sensory syndromes, particularly human sensory/obesity syndromes, such as Alstrom's and Bardet/Biedl, although no human candidate genes have been identified. Because of their unique phenotype, tubby mice are an appropriate model in which to look for a primary axonemal defect. We studied the axonemal ultrastructure of photoreceptors and sperm cells and performed functional testing of sperm in tub/tub mice before and after the onset of obesity. Approximately 15% of photoreceptor axonemes appeared abnormal in tub/tub animals, compared to 0% in controls. Both tub homozygotes and controls exhibited approximately 10% abnormal sperm cell axonemes, and no differences in sperm cell motile function were found at any age. The modest occurrence of axonemal defects in photoreceptors of tub/tub animals is likely to be a secondary effect of retinal degeneration. We conclude that the tubby phenotype is not associated with a generalized defect of cilia- and flagella-bearing cells and that the tub mutation does not primarily affect axonemal structure.

Abnormalities, Multiple↗
PubMed1998

Gene expression of nitric oxide synthase in cultured human term placental trophoblast during in vitro differentiation.

The human placental syncytiotrophoblast is derived from differentiating cytotrophoblasts and is in contact with maternal blood. This endothelial function positions the trophoblast to regulate maternal-fetal exchange and to influence circulatory dynamics through paracrine interactions in the placenta. Two isoforms of nitric oxide synthase (NOS) are expressed in placenta, and northern analysis, reverse transcription-polymerase chain reaction (RT-PCR), and immunocytochemistry were used to correlate expression of the type II, inducible NOS (iNOS) and the type III, endothelial NOS (eNOS) with state of differentiation in cultured trophoblast from term placentae. It was also tested whether cytokines known to induce NOS in other cell systems would induce iNOS in human trophoblast. The mRNA for eNOS was detected by RT-PCR, but not by Northern analysis, in cultures grown for 24 h when cytotrophoblasts were dominant. In contrast, eNOS mRNA was abundant in cultures grown for 72 h when syncytiotrophoblast was present. Immunocytochemical staining for eNOS protein showed specific fluorescence in a few cells in cultures at 24 h, but the vast majority of cells expressed eNOS at 72 h. The iNOS isoform was expressed neither basally in any trophoblast culture nor was this isoform induced in cultures exposed to interleukin-1, tumour necrosis factor-alpha, interferon-gamma and lipopolysaccharide. The in vitro pattern of trophoblast eNOS expression models the in vivo pattern of eNOS expression described for villous trophoblast. The results suggest that eNOS plays a role in human trophoblast differentiation and function.

Base Sequence↗
PubMed1998

The role of nitric oxide in oocyte meiotic maturation and ovulation: meiotic abnormalities of endothelial nitric oxide synthase knock-out mouse oocytes.

Evidence supports the involvement of nitric oxide (NO) in ovulation, steroidogenesis, and atresia-related apoptosis. This study was designed to investigate the role of endothelial nitric oxide synthase (eNOS)-derived NO in ovulation, oocyte meiotic maturation, and ovarian steroidogenesis using wild-type (WT) mice and mice in which the gene for eNOS had been deleted (eNOS knock-out). We observed that mature eNOS knock-out females have significantly fewer pups born in each litter and a higher mortality rate of pups than those born to heterozygote or WT females (P < 0.05). To determine the influence of eNOS deficiency on ovarian function, immature WT and eNOS knock-out mice were superovulated by injecting PMSG (5 IU) followed by an injection of hCG (5 IU, i.p.) 48 h later. To determine whether murine oocytes expressed eNOS before (0 and 8 h post-hCG) and after ovulation (16 h post-hCG). we performed immunofluorescent staining. Positive specific staining for eNOS was observed on the surface of ovarian and ovulated oocytes obtained from WT mice, but not on oocytes from eNOS knock-out mice. To determine the role of eNOS-derived NO in ovulation, ovulated oocytes were counted 16 h post-hCG. eNOS knock-out females showed a significant reduction (by 63%; P < 0.0001) in ovulatory efficiency compared with WT females. The reduction in the ovulation rate in eNOS-deficient mice compared with that in WT mice was also associated with a higher concentration of estradiol (P < 0.01) without significant changes in the plasma progesterone level. eNOS deficiency impaired not only ovulation, but also oocyte meiotic maturation. Ovulated oocytes were classified as being in one of the following stages of meiosis: metaphase I, metaphase II, or showing atypical (degenerative) morphology. We observed that fewer oocytes from eNOS knock-out mice had entered metaphase II of meiosis, and a greater percentage remained in metaphase I or were atypical (P < 0.002) relative to those in WT mice. Furthermore, many oocytes that showed either a delay in meiotic maturation or abnormal morphology were undergoing cell death. Our results support a role for NO in the ovulatory process. The ovarian defects observed in the eNOS knock-out mice suggest that eNOS-derived NO is a modulator of oocyte meiotic maturation.

Animals↗
PubMed1997

Pediatricians' experience with and attitudes toward firearms. Results of a national survey.

BACKGROUND: In 1992, the American Academy of Pediatrics issued statements calling for aggressive actions to reduce the dangers of firearms to children and adolescents, including removing handguns from homes with children and working toward a ban on the manufacture, sale, and private possession of handguns. OBJECTIVES: To determine the extent to which pediatricians support these positions against firearms and to describe the demographic and practice determinants of their views. INTERVENTIONS: In 1994, data were obtained from 982 pediatricians involved in direct patient care in a national, random-sample survey of American Academy of Pediatrics members (response rate, 68.9%). This article focuses on 4 areas: (1) recent experience treating gun injuries, (2) attitudes toward legislation to reduce the availability of guns, (3) attitudes toward gun safety counseling by pediatricians, and (4) current gun safety counseling practices. Wherever possible, chi 2 and t tests were used to compare responses to a similar 1988 survey of American Academy of Pediatrics members. Logistic regression was used to examine the multivariate relationships between the outcome variables and demographic and practice characteristics of the responding pediatricians. RESULTS: Almost 1 in 5 pediatricians treated a gun injury in the past 12 months. In 1988, 86.5% of pediatricians supported restricting the sale and possession of handguns; in 1994, support for such legislation increased to 92.5% (P < .01). Also in 1994, 76% supported banning the sale or possession of handguns. Most respondents (82%) believe anticipatory guidance on firearm safety can reduce injury and death; 95% support asking parents to unload and lock firearms, and 66% support encouraging parents to remove handguns from the home. Current counseling practices lag behind attitudinal support of anticipatory guidance on firearm safety (eg, half of respondents report never identifying families with firearms in the home). Demographic factors as well as professional experience were found to affect attitudes (eg, women, older pediatricians, and those who did not own guns were more likely to support gun-control legislation; and pediatricians who have recently treated gun injuries and those practicing in the inner city are more likely to counsel families about gun safety). CONCLUSIONS: The data indicate that practicing pediatrician overwhelmingly agree that handguns in the home are hazardous and that steps should be taken to reduce this hazard through legislation and patient counseling. They support the policies on firearms and handguns of the American Academy of Pediatrics; most support even the strongest recommendation, which is a ban on handguns. A substantial lag between attitudes that favor counseling about firearms and reported practices indicates the need for further training in and evaluation of firearm counseling in office settings.

Adolescent↗
PubMed1997

Role of steroidogenic-factor 1 in basal and 3',5'-cyclic adenosine monophosphate-mediated regulation of cytochrome P450 side-chain cleavage enzyme in the mouse.

The orphan receptor steroidogenic factor-1 (SF-1) plays a major role in adrenal and gonadal development and sexual differentiation, and it has been shown to interact with shared promotor elements to increase the expression of cytochrome P450 side-chain cleavage (P450scc) and other steroid hydroxylases in vitro. We took a step-wise approach to define the role of SF-1 in regulation of hormone-induced steroidogenesis. In a mouse Leydig cell line (MA-10) we show that hCG and forskolin are effective inducers of progesterone production and P450scc expression. In contrast, endogenous SF-1 expression was not increased by either hCG or forskolin. Similarly, these agents did not enhance the activity of SF-1 promoter transfected into MA-10 cells. The transcriptional activity of SF-1, measured by induction of an SF-1 synthetic reporter, was only minimally increased by forskolin. Within the context of the rat P450SCC promoter, mutation of the two SF-1-binding sites caused a dramatic decrease in constitutive activity of this promoter, but the degree of induction by 8-bromo-cAMP was only reduced from 7.9-fold to 5.9-fold. We conclude that SF-1 is required for the constitutive activity of P450scc, but that it does not play a direct role in the early induction of steroidogenesis by hCG or forskolin in MA-10 cells.

8-Bromo Cyclic Adenosine Monophosphate↗
PubMed1997

Hormonal regulation of nitric oxide synthases and their cell-specific expression during follicular development in the rat ovary.

Nitric oxide (NO) has emerged as a novel regulator of several ovarian events, such as ovulation, steroidogenesis, and apoptotic cell death. The NO synthases (NOS) are a family of enzymes that catalyze the oxidation of L-arginine to NO and L-citrulline. The purpose of the present study was to localize NOS isoforms in the rat ovary and to examine their hormonal regulation. We conducted immunohistochemistry and Western blot analysis using isoform-specific antibodies against brain NOS, endothelial NOS (eNOS), and inducible NOS (iNOS). Immature rats were superovulated by injecting PMSG (10 I.U. s.c.) followed by an injection of human CG (hCG; 10 I.U. s.c.) 48 h later. Ovaries were obtained from control rats (no PMSG), 24 h and 48 h after PMSG treatment and 2 h, 8 h, 12 h, 20 h or 6 days and 10 days after hCG injection (n = 3-5 rats/group). Rat ovaries were clearly devoid of brain NOS staining at any of the time points studied. In control ovaries, eNOS was detected in the theca cell layer, ovarian stroma, and on the surface of oocytes. During follicular development, eNOS staining was still expressed in the theca cell layer and was also present in mural granulosa cells. After ovulation, homogenous eNOS staining was observed within cells of the corpus luteum (CL). Western blots of ovarian homogenates demonstrated that during PMSG-induced follicle growth, eNOS levels increased by 2.5-fold relative to control rats (P < 0.05). eNOS levels were further increased 12 h and 20 h after hCG injection (5-fold and 7-fold, respectively, relative to control; P < 0.05). The greatest amount of eNOS was observed in ovaries 10 days after hCG injection (15-fold relative to control; P < 0.05). We also detected expression of iNOS in the ovary, but the pattern and cell-specific staining differed from that observed for eNOS. In immature ovaries and during follicular development, iNOS staining was found within the theca cell layer and stroma. After ovulation, iNOS staining was present only in the external layers of the developing CL, but in the degenerating CL (10 days post-hCG), strong staining in nonparenchymal cells was observed within the entire CL. Western blots showed no changes in levels of ovarian iNOS protein during follicular development, but a significant increase (6-fold relative to control; P < 0.05) was observed after an ovulatory dose of hCG. The highest level of iNOS was observed in ovaries 10 days after hCG injection (10-fold relative to control; P < 0.05). Our data demonstrate that ovarian eNOS and iNOS show distinct cell-specific expression patterns and are differentially regulated during follicular and luteal development.

Animals↗
PubMed1996

Identification of pseudohypacusis using speech recognition thresholds.

OBJECTIVE: To determine the extent to which procedural variations affect pure-tone average-spondee threshold (PTA-SRT) agreement in pseudohypacusis, to propose a theoretical framework to account for threshold differences due to procedural variations, and to devise an effective screening test for identification of pseudohypacusis. DESIGN: The subjects were normally hearing listeners who feigned a hearing loss. One experimental group received an ascending pure-tone (PT) technique combined with an ascending SRT procedure. A second experimental group received an ascending PT technique paired with a descending SRT procedure. A third experimental group received an ascending SRT procedure paired with a descending PT procedure. RESULTS: The group mean difference between the three-frequency PTA and the SRT was 10.6, 2.3, and 41.6 dB for the first, second, and third experimental groups, respectively. Comparison SRTs and PTAs from cooperative patients with hearing loss showed that a two-frequency PTA yielded a more effective test for pseudohypacusis than did a three-frequency PTA. CONCLUSIONS: The procedural differences noted in this study are consistent with a loudness bias. It is recommended that clinicians employ an ascending procedure to measure SRTs and a descending procedure to measure PT thresholds to maximize the effectiveness of a screening test for pseudohypacusis based on PTA-SRT differences.

Adult↗
PubMed1996

Nitric oxide decreases estradiol synthesis of rat luteinized ovarian cells: possible role for nitric oxide in functional luteal regression.

This study was designed to examine the synthesis and function of nitric oxide during follicular development and luteinization in the rat ovary. Cells were obtained from hypophysectomized diethylstilbestrol-implanted immature female rats subjected to several hormonal regimens that resulted in preantral, Graafian, ovulatory, atretic, or luteinized ovaries. Cells obtained from ovaries at all stages of follicular development synthesized nitric oxide in a linear manner over time. The basal production of nitric oxide was 6- to 14-fold higher (P < 0.009) in cells obtained from luteinized ovaries than that in cells obtained from ovaries at all other developmental stages. Inhibiting endogenous nitric oxide synthesis in cells obtained from luteinized ovaries resulted in a 3-fold increase (P < 0.007) in the estradiol level without affecting progesterone synthesis. We used isoform-specific antisera to determine the cellular location and isoform(s) of nitric oxide synthase expressed in our cell culture system and in the luteinized ovary in vivo. Positive immunofluorescent staining for both the endothelial and inducible isoforms was observed in separate cell types. Immunoblotting experiments also showed that luteinized ovaries express the endothelial and inducible isoforms of nitric oxide synthase. Nitric oxide synthesis inhibits estradiol synthesis in vitro. We suggest that nitric oxide participates in functional luteal regression by inhibiting steroidogenesis.

Animals↗
PubMed1995

Cell-specific localization of apolipoprotein E messenger ribonucleic acid in the testis and epididymis of the rat.

Apolipoprotein (apo) E, a 35-kDa protein found on the surface of several lipoproteins, has been detected in many peripheral tissues and is postulated to function in facilitating the transfer of cholesterol/lipids between cells. We examined the expression of apo E mRNA in the testes and epididymides of juvenile rats (21 days old), prepubescent rats (34-36 days old), and sexually mature rats (75-80 days old). In situ hybridization using 35S-labeled rat apo E riboprobes was used to identify cells containing apo E mRNA. Such cells were located in the interstitial area of testes obtained from rats of all ages. This cell population consisted of primarily Leydig cells with occasional macrophages, according to immunoreactivity to 3 beta-hydroxysteroid dehydrogenase and antimacrophage antibodies, respectively. Caput epididymides obtained from sexually mature and prepubescent rats contained apo E mRNA-positive cells located in the basal region of the epididymal tubules and within the interstitial stroma. Our data are consistent with the concept that locally produced apo E plays a role in the physiologic function of the rat testis and epididymis.

Aging↗
PubMed1995

Retrospective versus concurrent review on the quality of care of pediatric trauma patients.

To compare and contrast retrospective versus concurrent quality of care review processes in a Level I Trauma Center, we conducted a retrospective chart review of all pediatric trauma admissions in 1990 (n = 113) and compared it to the concurrent trauma quality assurance program for the same time period. Twenty-four percent (24%) of the patients reviewed in the retrospective study were identified by filters and reviewed through the concurrent process. In both the retrospective and concurrent review process problems in medical care problems, documentation, social and preventive elements of the case, and overall assessment of the patients' care were described. Overall, we found less than 50% agreement between the two reviews. The retrospective review identified medical care issues in 64% of cases, compared with a 44% error rate noted in the concurrent review (P < 0.07). Reviewers were more likely to note the absence of appropriate documentation, and overall assessment of the patients' care in the retrospective process (P < 0.0001). The retrospective review also highlighted issues related to the prevention of the injury and the patients' social situation, which were not considered by the concurrent review. Overall, we found the concurrent review appropriate for case by case medical management, while the retrospective review was relevant to a systems approach to the care of the injured child. To obtain a complete picture of the care of injured children, we recommend 1) a portion of charts be reviewed retrospectively in addition to ongoing concurrent review; or 2) the concurrent review add filters that are specific to pediatric issues and overall system issues.

Adolescent↗
PubMed1994

Immunolocalization of apolipoprotein E in the testis and epididymis of the rat.

Apolipoprotein (apo) E, a 35-kDa protein found on the surface of several lipoproteins, has been detected in many peripheral tissues and is postulated to function in facilitating the transfer of cholesterol/lipids between cells. We examined the expression of apo E in the testes and epididymides of juvenile rats (21 days old), prepubescent rats (34-36 days old) and sexually mature rats (75-80 days old). Apo E was localized by means of a polyclonal rabbit anti-rat apo E antibody and standard immunocytochemical techniques. Strong positive staining for apo E was observed in the interstitial space of the tests from all rats. Apo E-containing cells were identified as Leydig cells through use of a 3 beta-hydroxysteroid dehydrogenase antibody on serial sections. In contrast to sexually mature rats, the two younger groups of rats also showed positive staining for apo E within the seminiferous tubule associated with Sertoli and germ cells. In addition, strong positive staining for apo E was observed in the stroma of the caput, corpus, and cauda epididymides from rats of all ages. This study demonstrates that apo E is differentially localized during development of the tests, suggesting a regulatory and/or cholesterol transport role.

3-Hydroxysteroid Dehydrogenases↗
PubMed1993

Analysis of childhood pedestrian deaths in New Mexico, 1986-1990.

STUDY OBJECTIVE: To determine if the mechanism of fatal childhood pedestrian injuries correlated with location, injury pattern, and age of the pedestrian and to determine ethnic differences in fatality rates. DESIGN: Retrospective review of state medical investigator reports and autopsies from 1986 to 1990. Logistic regression and chi 2 were used to test for statistically significant differences between the groups in our data set. TYPE OF PARTICIPANTS: New Mexican children, 0 to 14 years old fatally injured by moving vehicles. RESULTS: Sixty-four children died for an overall fatality rate of 3.8 (per 100,000). Native American children and children younger than 5 years experienced the highest fatality rates. Children younger than 5 years were more likely to be crushed under the wheels of a slow-moving vehicle in both a nontraffic and a traffic location, whereas older children were found more often to have died from injuries from a high-speed impact event in a traffic location (P < .001). Leg fractures (P = .001) and spinal fractures (P = .02) occurred more frequently in impact than crush injuries. CONCLUSION: Young children are at risk for a crush injury in both the traffic and nontraffic environment.

Accidents, Traffic↗