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Biomedical subjects

P Frankel

Publications and source records attributed to P Frankel.

At least 19 recordsLinked to original sources

Pharmacogenetic analysis of paclitaxel transport and metabolism genes in breast cancer.

Paclitaxel is commonly used in the treatment of breast cancer. Variability in paclitaxel clearance may contribute to the unpredictability of clinical outcomes. We assessed genomic DNA from the plasma of 93 patients with high-risk primary or stage IV breast cancer, who received dose-intense paclitaxel, doxorubicin and cyclophosphamide. Eight polymorphisms in six genes associated with metabolism and transport of paclitaxel were analyzed using Pyrosequencing. We found no association between ABCB1, ABCG2, CYP1B1, CYP3A4, CYP3A5 and CYP2C8 genotypes and paclitaxel clearance. However, patients homozygous for the CYP1B1*3 allele had a significantly longer progression-free survival than patients with at least one Valine allele (P=0.037). This finding could reflect altered paclitaxel metabolism, however, the finding was independent of paclitaxel clearance. Alternatively, the role of CYP1B1 in estrogen metabolism may influence the risk of invasive or paclitaxel resistant breast cancer in patients carrying the CYP1B1*3 allele.

Adult↗

Maintenance thalidomide following single cycle autologous peripheral blood stem cell transplant in patients with multiple myeloma.

Although autologous stem cell transplant is an effective therapy for patients with multiple myeloma and extends progression-free survival (PFS) and overall survival (OS), patients show a continued pattern of recurrent disease. Twenty-nine patients were enrolled in a phase II study investigating the tolerability and efficacy of maintenance thalidomide following single autologous peripheral blood stem cell transplant. Six to eight weeks after transplant, patients were started on maintenance thalidomide at 50 mg a day. The dose was gradually escalated to a target dose of 400 mg a day and continued until disease progression or 6 months after achieving complete remission (CR) for a maximum total duration of 18 months. At 6 months, 13 patients (45%) achieved CR or near complete remission (positive immunofixation without any evidence of disease). The estimated 2-year OS was 83% and PFS was 49%. Median tolerated dose of thalidomide was 200 mg a day. In conclusion, thalidomide as maintenance therapy is feasible and may improve outcome after single autologous stem cell transplant.

Aged↗

The tomato dark green mutation is a novel allele of the tomato homolog of the DEETIOLATED1 gene.

A comprehensive, multi-generation, allele test, carried out in this study, suggests that the tomato mutations dark-green (dg) and high pigment 2(j) (hp-2(j)) are allelic. The hp-2(j) mutant is caused by a mutation in the tomato homolog of the DEETIOLATED1 (DET1) gene, involved in the signal transduction cascade of light perception and morphogenesis. This suggestion is in agreement with the exaggerated photomorphogenic de-etiolation response of homozygous dg mutants grown under modulated light conditions. Sequence analysis of the DET1 gene was carried out in dg mutants representing two different lines, and revealed a single A-to-T base transversion in the second exon of the DET1 gene in comparison with the normal wild-type sequence. This transversion results in a conserved Asparagine(34)-to-Isoleucine(34) amino-acid substitution, and eliminates a recognition site for the AclI restriction endonuclease, present in the wild-type and in the other currently known tomato mutants at the DET1 locus. This polymorphism was used to develop a PCR-based DNA marker, which enables an early genotypic selection for breeding lycopene-rich tomatoes. Using this marker and sequence analysis we demonstrate that an identical base transversion also exists in dg mutants of the cultivar Manapal, in which the natural dg mutation was originally discovered. A linkage analysis, carried out in a F(2) population, shows a very strong linkage association between the DET1 locus of dg mutant plants and the photomorphogenic response of the seedlings, measured as hypocotyl length (12 < LOD Score < 13, R(2) = 51.1%). The results presented in this study strongly support the hypothesis that the tomato dg mutation is a novel allele of the tomato homolog of the DET1 gene.

Alleles↗

Predictors of long-term outcome following high-dose chemotherapy in high-risk primary breast cancer.

We report on a predictive model of long-term outcome in 114 high-risk breast cancer patients treated with high-dose chemotherapy between 1989 and 1994. Paraffin-blocks from 90 of the 114 primaries were assessed for the presence of five risk factors: grade, mitotic index, protein expression of p53, HER2/neu, and oestrogen/progesterone receptor status; we could analyse the effect of risk factors in 84 of these 90 tumours. Seven-year relapse-free and overall survival was 58% (95% confidence interval 44-74%) and 82% (95% confidence interval 71-94%) vs 33% (95% confidence interval 21-52%) and 41% (95% confidence interval 28-60%) for patients whose primary tumours displayed > or =3 risk factors vs patients with < or =2 risk factors. For the entire group of 168 high-risk breast cancer patients, inflammatory stage IIIB disease and involved post-mastectomy margins were associated with decreased relapse-free survival and overall survival; patients treated with non-doxorubicin containing standard adjuvant therapy experienced worse overall survival (RR, 2.08; 95% confidence interval 1.04 to 4.16; P=0.04), while adjuvant tamoxifen improved overall survival (RR, 0.65; 95% confidence interval 0.41-1.01; P=0.054). Future trial designs and patient selection for studies specific for high-risk breast cancer patients should include appropriate prognostic models. Validation of such models could come from recently completed randomised, prospective trials.

Adult↗

RalA mediates v-Src, v-Ras, and v-Raf regulation of CD44 and fibronectin expression in NIH3T3 fibroblasts.

Oncogenic transformation of fibroblasts by v-Src and v-Ras is often associated with downregulation of fibronectin (FN) and increased expression of CD44, a receptor for hyaluronan. Both v-Src and v-Ras as well as v-Raf activate phospholipase D through the small GTPase, RalA, an important mediator of transformation and tumorigenesis in vivo. We have therefore investigated whether RalA is involved in the downregulation of FN and overproduction of CD44 upon oncogenic transformation. We report here that compared to untransfected cells NIH3T3 cells transformed by v-Src, v-Ras, or v-Raf have reduced levels of FN and increased levels of CD44. Moreover, the ability to form extracellular FN fibrils was significantly reduced in the oncogene-transformed cells compared to parental controls. Coexpression of the dominant negative S28N-RalA mutant restored the levels of CD44 and FN and the capacity of v-Src-, v-Ras-, and v-Raf-expressing cells to form extracellular FN fibrils, to those observed in NIH3T3 cells. The data presented here show a novel regulatory role for RalA, which is required for tumor formation in transformed NIH3T3 cells, in mediating the signal transduction pathway activated by v-Src, v-Ras, and v-Raf, that leads to FN downregulation and CD44 overexpression.

3T3 Cells↗

Activity of high-dose toremifene plus cisplatin in platinum-treated non-small-cell lung cancer: a phase II California Cancer Consortium Trial.

PURPOSE: Although cisplatin is an important agent in non-small-cell lung cancer (NSCLC), de novo resistance is common and acquired resistance emerges rapidly during therapy. Proposed mediators of platinum resistance include the protein kinase C (PKC) signal transduction pathway and associated c-FOS overexpression. While estrogen administration has been reported to upregulate PKC and c-FOS expression, the triphenylethylenes tamoxifen and toremifene potentiate platinum cytotoxicity by inhibition of PKC. Downregulation of c-FOS expression has been reported to result from PKC inhibition. In view of these findings, we hypothesized that toremifene would reverse platinum resistance and that this interaction would be influenced by tumor estrogen receptor (ER) status. MATERIALS AND METHODS: A phase II trial of high-dose toremifene (600 mg orally daily on days 1-7) plus cisplatin (50 mg/m2 intravenously on days 4 and 11) every 28 days in NSCLC patients was conducted. A group of 30 patients with metastatic NSCLC who had been previously treated with platinum-based therapy were enrolled. RESULTS: All of the 30 patients were assessable for toxicity and 28 for tumor response. Therapy was well tolerated with minimal hematologic and non-hematologic toxicity. Common toxicity criteria grade 3 hematologic toxicity was seen in only three patients. Five patients achieved a partial response for an overall response rate of 18% (95% CI 6-37). Median overall survival was 8.1 months (95% CI 5.4-17). To assess PKC, ER, and c-Fos expression by immunohistochemistry, 12 informative pretreatment patient tumor specimens were obtained. Four patient tumor specimens were positive for one or both PKC isoforms (alpha and epsilon) while c-Fos was overexpressed in three. None of the responding patient tumors exhibited c-FOS or PKC-epsilon overexpression. ER expression was found to be infrequent (8%), contrasting with previous reports in this tumor type. CONCLUSION: While this phase II study indicates that high-dose toremifene plus cisplatin is feasible, active, and well tolerated in NSCLC patients previously treated with platinum compounds, the mechanism of action remains unclear. Further study of this regimen is warranted.

Adult↗

Tandem-cycle high-dose melphalan and cisplatin with peripheral blood progenitor cell support in patients with breast cancer and other malignancies.

We evaluated the feasibility of tandem-cycle high-dose chemotherapy (HDCT) with cisplatin, melphalan, and peripheral blood progenitor cells (PBPCs). Fifty patients with high-risk primary (n = 17) or stage IV breast cancer (n = 29) or other malignancies (n = 4) received 2 cycles of intravenous melphalan, 20 to 151.8 mg/m2, and cisplatin, 200 mg/m2, followed by granulocyte-macrophage colony-stimulating factor (GM-CSF) or G-CSF. Starting at 40 mg/m2 of melphalan, patients also received PBPCs. Delayed platelet recovery defined the maximum tolerated dose (MTD) for melphalan at 101.2 mg/m2 per cycle. There were no treatment-related deaths. Cycle 2 was delivered at a median of 1.7 months after cycle 1; 72% of patients treated at the MTD received both cycles. Cycle 2 was omitted when patients refused it or had disease progression or toxicities, primarily prolonged thrombocytopenia. Complete response rates in stage IV breast cancer patients increased from 28% pre-HDCT to 55% after cycle 2. At a median follow-up of 4.6 years (range, 1.5-8.1 years), 11 of 29 patients with stage IV breast carcinoma were alive with 5-year projected progression-free and overall survival rates of 19% (95% confidence interval [CI], 7%-41%) and 39% (95% CI, 20%-62%), respectively. Five-year projected progression-free and overall survival rates for patients with stage IV breast cancer in complete response following HDCT versus all others were 35% (95% CI, 15%-70%) versus 0% (P = .01) and 61% (95% CI, 35%-91%) versus 10% (95% CI, 2%-60%) (P = .003; log-rank test), respectively. Estrogen-receptor positivity was predictive of reduced risk of progression (relative risk [RR], 0.25; 95% CI, 0.10-0.65; P = .003) and death (RR, 0.27; 95% CI, 0.10-0.72; P = .009) after adjusting for response status. Five-year projected relapse-free and overall survival rates were 71% (95% CI, 43%-96%) and 82% (95% CI, 56%-100%), respectively, for the 17 patients with high-risk primary breast cancer. Tandem-cycle high-dose melphalan and cisplatin with PBPCs is feasible. Preliminary data suggest significant activity in selected patients with stage IV responding breast carcinoma.

Adult↗

Mitogenic phospholipase D activity is restricted to caveolin-enriched membrane microdomains.

Phospholipase D (PLD) activity is elevated in response to the oncogenic stimulus of several signaling oncogenes. PLD activity is also elevated in response to peptide growth factors, indicating that PLD likely plays an important role in mitogenic signaling. Many proteins that mediate mitogenic signaling are localized in caveolin-enriched membrane microdomains (CEMMs). We report here that the elevated PLD activity in NIH 3T3 cells transformed by activated oncogenic forms of Src, Ras, and Raf is largely restricted to the CEMMs. Likewise, the PLD activity stimulated by epidermal growth factor is also restricted to the CEMMs. Although both PLD1 and PLD2 were found in CEMMs, neither was particularly enriched in the CEMMs of the transformed relative to the parental cells, indicating that it is the specific activity of PLD that is increased in the CEMMs. An apparent PLD substrate specificity in transformed cells for phosphatidylcholine lacking arachidonate acyl groups is also explained by the localization of activity in the CEMMs where [(3)H]arachidonate-labeled PC was excluded. These data indicate that mitogenic signals through PLD are initiated in CEMMs where many signaling molecules colocalize.

3T3 Cells↗

Phospholipase D and RalA cooperate with the epidermal growth factor receptor to transform 3Y1 rat fibroblasts.

3Y1 rat fibroblasts overexpressing the epidermal growth factor (EGF) receptor (EGFR cells) become transformed when treated with EGF. A common response to oncogenic and mitogenic stimuli is elevated phospholipase D (PLD) activity. RalA, a small GTPase that functions as a downstream effector molecule of Ras, exists in a complex with PLD1. In the EGFR cells, EGF induced a Ras-dependent activation of RalA. The activation of PLD by EGF in these cells was dependent upon both Ras and RalA. In contrast, EGF-induced activation of Erk1, Erk2, and Jun kinase was dependent on Ras but independent of RalA, indicating divergent pathways activated by EGF and mediated by Ras. The transformed phenotype induced by EGF in the EGFR cells was dependent upon both Ras and RalA. Importantly, overexpression of wild-type RalA or an activated RalA mutant increased PLD activity in the absence of EGF and transformed the EGFR cells. Although overexpression of PLD1 is generally toxic to cells, the EGFR cells not only tolerated PLD1 overexpression but also became transformed in the absence of EGF. These data demonstrate that either RalA or PLD1 can cooperate with EGF receptor to transform cells.

Animals↗

RalA requirement for v-Src- and v-Ras-induced tumorigenicity and overproduction of urokinase-type plasminogen activator: involvement of metalloproteases.

Overproduction of urokinase-type plasminogen activator (uPA) and metalloproteases (MMPs) is strongly correlated with tumorigenicity and with invasive and metastatic phenotypes of human and experimental tumors. We demonstrated previously that overproduction of uPA in tumor cells is mediated by a phospholipase D (PLD)- and protein kinase C-dependent mechanism. The oncogenic stimulus of v-Src and v-Ras results in the activation of PLD, which is dependent upon the monomeric GTPase RalA. We have therefore investigated whether RalA plays a role in uPA and MMP overproduction that is observed in response to oncogenic signals. We report here that NIH3T3 cells transformed by both v-Src and v-Ras, constitutively overproduce uPA and that expression of a dominant negative RalA mutant (S28N) blocks overproduction of uPA in both the v-Src-and v-Ras-transformed cells. v-Src and v-Ras also induced an upregulation of the activity of MMP-2 and MMP-9 as detected by zymograms, however only the v-Src induction correlated with MMP protein levels detected by Western blot analysis. The dominant negative RalA mutant blocked increased MMP-2 and 9 overproduction induced by v-Src, but not the increased activity of MMP-2 and 9 induced by v-Ras. And, consistent with a role for the RalA/PLD pathway in mitogenesis and tumor development, the dominant negative RalA mutant completely blocked tumor formation by v-Src- and v-Ras-transformed NIH3T3 cells injected subcutaneously in syngeneic mice. The data presented here implicate RalA and PLD as signaling mediators for tumor formation and protease production by transformed cells.

3T3 Cells↗

Ral and Rho-dependent activation of phospholipase D in v-Raf-transformed cells.

Phospholipase D (PLD) activity is commonly elevated in response to mitogenic signals. We reported previously that although the transformed phenotype induced by v-Src was dependent upon Raf-1, the PLD activity induced by v-Src was independent of Raf-1. This observation suggested to us that Raf would not likely be an activator of PLD. However, upon examination of PLD activity in v-Raf-transformed cells, surprisingly, we found that PLD activity is elevated to levels that were even higher than that observed in v-Src-transformed cells. To characterize the mechanism of v-Raf-induced PLD activity, we examined the dependence of v-Raf-induced PLD activity upon protein kinase C (PKC) the small GTPases Ral and Rho, which have all been implicated in the activation of PLD. The v-Raf-induced PLD activity was inhibited by dominant negative mutants for both Ral and Rho. The dependence upon Ral was particularly surprising since Ral is a downstream target of Ras, which is an upstream activator of Raf. Depleting cells of PKC by long term phorbol ester treatment actually increased PLD activity in v-Raf-transformed cells, indicating that v-Raf-induced PLD activity is not dependent on PKC. These data describe a novel mechanism for PLD activation by v-Raf that is independent of PKC, but dependent upon both Ral and Rho GTPases.

3T3 Cells↗

Antagonistic effects of protein kinase C alpha and delta on both transformation and phospholipase D activity mediated by the epidermal growth factor receptor.

Downregulation of protein kinase C delta (PKC delta) by treatment with the tumor-promoting phorbol ester 12-O-tetradecanoylphorbol-13-acetate (TPA) transforms cells that overexpress the non-receptor class tyrosine kinase c-Src (Z. Lu et al., Mol. Cell. Biol. 17:3418-3428, 1997). We extended these studies to cells overexpressing a receptor class tyrosine kinase, the epidermal growth factor (EGF) receptor (EGFR cells); like c-Src, the EGF receptor is overexpressed in several human tumors. In contrast with expectations, downregulation of PKC isoforms with TPA did not transform the EGFR cells; however, treatment with EGF did transform these cells. Since TPA downregulates all phorbol ester-responsive PKC isoforms, we examined the effects of PKC delta- and PKC alpha-specific inhibitors and the expression of dominant negative mutants for both PKC delta and alpha. Consistent with a tumor-suppressing function for PKC delta, the PKC delta-specific inhibitor rottlerin and a dominant negative PKC delta mutant transformed the EGFR cells in the absence of EGF. In contrast, the PKC alpha-specific inhibitor Go6976 and expression of a dominant negative PKC alpha mutant blocked the transformed phenotype induced by both EGF and PKC delta inhibition. Interestingly, both rottlerin and EGF induced substantial increases in phospholipase D (PLD) activity, which is commonly elevated in response to mitogenic stimuli. The elevation of PLD activity in response to inhibiting PKC delta, like transformation, was dependent upon PKC alpha and restricted to the EGFR cells. These data demonstrate that PKC isoforms alpha and delta have antagonistic effects on both transformation and PLD activity and further support a tumor suppressor role for PKC delta that may be mediated by suppression of tyrosine kinase-dependent increases in PLD activity.

Acetophenones↗

Functional association between Arf and RalA in active phospholipase D complex.

Activation of phospholipase D1 (PLD1) by Arf has been implicated in vesicle transport and membrane trafficking. PLD1 has also been shown to be associated with the small GTPase RalA, which functions downstream from Ras in a Ras-RalA GTPase cascade that facilitates intracellular signal transduction. Although PLD1 associates directly with RalA, RalA has no effect upon the activity of PLD1. However, PLD1 precipitated from cell lysates with immobilized glutathione S-transferase-RalA fusion protein is active. This suggests the presence of an additional activating factor in the active RalA-PLD1 complexes. Because Arf stimulates PLD1, we looked for the presence of Arf in the active RalA-PLD1 complexes isolated from v-Src- and v-Ras-transformed cell lysates. Low levels of Arf protein were detected in RalA-PLD1 complexes; however, if guanosine 5'-[gamma-thio]triphosphate was added to activate Arf and stimulate translocation to the membrane, high levels of Arf were precipitated by RalA from cell lysates. Interestingly, deletion of 11 amino-terminal amino acids unique to Ral GTPases, which abolished the ability of RalA to precipitate PLD activity, prevented the association between RalA and Arf. Brefeldin A, which inhibits Arf GDP-GTP exchange, inhibited PLD activity in v-Src- and v-Ras-transformed cells but not in the nontransformed cells, suggesting that the association of Arf with RalA is required for the increased PLD activity induced by v-Src and v-Ras. These data implicate Arf in the transduction of intracellular signals activated by v-Src and mediated by the Ras-RalA GTPase cascade. Because both Arf and PLD1 stimulate vesicle formation in the Golgi, these data raise the possibility that vesicle formation and trafficking may play a role in the transduction of intracellular signals.

3T3 Cells↗

Novel recruitment of Shc, Grb2, and Sos by fibroblast growth factor receptor-1 in v-Src-transformed cells.

In response to fibroblast growth factor (FGF), FGF receptor-1 (FGFR-1) (flg) becomes tyrosine phosphorylated and associates with phospholipase C gamma (PLC gamma) and a 90 kDa protein. We report here that in cells transformed by v-Src, FGFR-1 becomes phosphorylated on tyrosine; however, neither PLC gamma nor p90 was found to be associated with tyrosine-phosphorylated FGFR-1. Instead, there was a strong constitutive association of FGFR-1 with the adaptor proteins Shc and Grb2 and the Ras guanine nucleotide exchange factor Sos. Association with Shc and Grb2 and Sos was not observed in response to FGF. Suramin did not prevent either tyrosine phosphorylation or Shc/Grb2/Sos association, indicating a non-autocrine mechanism. Thus, in cells transformed by v-Src, tyrosine phosphorylation of FGFR-1 results not in the expected association with PLC gamma and p90, but rather in the recruitment of the Ras activating Shc/Grb2/Sos complex. These data suggest a mechanism for Ras activation by v-Src involving phosphorylation of novel tyrosine(s) on FGFR-1.

3T3 Cells↗

Activation of gene expression by a non-transforming unmyristylated-SH3-deleted mutant of Src is dependent upon Tyr-527.

v-Src transcriptionally induces gene expression by activating several transcriptional response elements such as the serum response element (SRE), the 12-O-tetradecanoylphorbol-13-acetate (TPA) response element (TRE), and the c-AMP response element (CRE) found in the promoters of several proliferation-related immediate early genes. We report here that a Src protein, with a deletion in the SH3 domain and lacking a membrane localization signal, strongly activates gene expression mediated by SRE, TRE and CRE transcriptional control elements. This mutant was unable to cause cellular transformation, suggesting that activation of these transcriptional control elements is not sufficient for the induction of a transformed phenotype by Src. Interestingly, the ability of the membrane localization and SH3 deletion mutant to activate gene expression was abolished upon conversion of the C-terminal inhibitory Tyr-527 to Phe. These data suggest the existence of previously unreported Tyr-527-dependent activation of intracellular signals that activate gene expression. These data raise the possibility that Src may exert physiological effects via an interaction between Tyr-527 and an SH2-containing protein that would interact with the phosphorylated form of Tyr-527.

3T3 Cells↗

Involvement of Ral GTPase in v-Src-induced phospholipase D activation.

An early response to the tyrosine kinase activity of v-Src is an increase in phospholipase D (PLD) activity, which leads to the generation of biologically active lipid second messengers, including phosphatidic acid, lysophosphatidic acid and diacylglycerol. We have recently demonstrated that v-Src-induced PLD activity is mediated by Ras, although Ras involvement was indirect, requiring a cytosolic factor for PLD activation. Ras interacts with and activates Ral-GDS, the exchange factor responsible for the activation of Ral GTPases. Here we report that this newly identified Ras/Ral signalling pathway mediates PLD activation by v-Src. PLD activity could be precipitated from v-Src-transformed cell lysates with immobilized RalA protein and with an anti-Ral antibody. A mutation to the region of RalA analogous to the 'effector domain' of Ras did not reduce the ability of RalA to complex with PLD, although deletion of a Ral-specific amino-terminal region did. Overexpression of RalA potentiated PLD activation by v-Src, and expression of dominant negative RalA mutants inhibited both v-Src- and v-Ras-induced PLD activity. Thus RalA is involved in the tyrosine kinase activation of PLD through its unique N terminus, and that PLD is a downstream target of a Ras/Ral GTPase cascade.

3T3 Cells↗

C5-6 cervical dislocation resulting from improper seat belt use.

Motorists may improperly use the diagonal shoulder belt of newer passive restraint systems by failing to use the lap belt. An unusual case of patient who did not wear a lap belt and who sustained a cervical C5-6 distraction injury resulting in quadriplegia is reported. Emergency physicians should be aware of this injury mechanism and should reinforce proper passive restraint use.

Accidents, Traffic↗

Injuries resulting from bicycle collisions.

OBJECTIVE: To review all bicycle crash-related injuries reported to the Oregon Injury Registry for 1989 to compare patterns of injury and other features in adults vs children and adolescents. METHODS: A retrospective descriptive study was conducted using data from the Oregon Injury Registry. For 1989, this registry included all injury-related deaths and approximately 75% of hospital admissions of 24 hours or more for injury in the State of Oregon. Deaths, helmet use, neurologic injuries, and concurrent ethanol use were evaluated for all patients and for the two age groups. RESULTS: There were 311 bicycle-related injured patients in the registry for 1989; 122 (40%) were adults (age > or = 21 years) and 189 (60%) were children/adolescents (age < 21 years). Approximately 69% of both age groups were male. All of the 15 deaths involved male patients and most deaths [10/15 (67%)] involved injured adults. Bicycle vs motor vehicle collisions accounted for 14 (93%) deaths and 106 (34%) of all registry entries. While only 19 (15%) of the injured adults had elevated blood alcohol levels, half the adults who died had been intoxicated. Helmet use was rare with only 12 (4%) of all the injured riders known to have been helmeted; no rider who died was known to have been helmeted. Neurologic injuries were common. In children, 27 (14%) had sustained skull fractures, 36 (19%) intracranial injuries, and one (0.5%) a spinal injury. In adults, 13 (10%) had sustained skull fractures, 32 (26%) intracranial injuries, and three (2%) spinal injuries. CONCLUSIONS: Although children account for 60% of the serious bicycle injuries in Oregon, adults account for 67% of the deaths. Helmet use is rare, brain injuries are frequent, and alcohol use appears to be a contributing factor in cycling deaths among adults. Public education efforts should be directed to both adult and pediatric populations, emphasizing safe cycling practices and helmet use.

Accidents, Traffic↗