Under-reporting bicycle accidents to police in the COST TU1101 international survey: Cross-country comparisons and associated factors.

Police crash reports are often the main source for official data in many countries. However, with the exception of fatal crashes, crashes are often underreported in a biased manner. Consequently, the countermeasures adopted according to them may be inefficient. In the case of bicycle crashes, this bias is most acute and it probably varies across countries, with some of them being more prone to reporting accidents to police than others. Assessing if this bias occurs and the size of it can be of great importance for evaluating the risks associated with bicycling. This study utilized data collected in the COST TU1101 action "Towards safer bicycling through optimization of bicycle helmets and usage". The data came from an online survey that included questions related to bicyclists' attitudes, behaviour, cycling habits, accidents, and patterns of use of helmets. The survey was filled by 8655 bicyclists from 30 different countries. After applying various exclusion factors, 7015 questionnaires filled by adult cyclists from 17 countries, each with at least 100 valid responses, remained in our sample. The results showed that across all countries, an average of only 10% of all crashes were reported to the police, with a wide range among countries: from a minimum of 0.0% (Israel) and 2.6% (Croatia) to a maximum of a 35.0% (Germany). Some factors associated with the reporting levels were type of crash, type of vehicle involved, and injury severity. No relation was found between the likelihood of reporting and the cyclist's gender, age, educational level, marital status, being a parent, use of helmet, and type of bicycle. The significant under-reporting - including injury crashes that do not lead to hospitalization - justifies the use of self-report survey data for assessment of bicycling crash patterns as they relate to (1) crash risk issues such as location, infrastructure, cyclists' characteristics, and use of helmet and (2) strategic approaches to bicycle crash prevention and injury reduction.

A portable bio-impedance system for monitoring lung resistivity.

The principles of a hybrid bio-impedance technique are implemented in a novel, lung resistivity monitoring system ("CardioInspect" Tel-Aviv University, Israel). The system is to be utilized in the clinic or at home, for daily monitoring of patients suffering from pulmonary edema. The developed system consists of an eight-electrode belt worn around the thorax, an electronic unit containing analog and digital boards, and a stand-alone DSP based system with a designated software to analyze the data. A Newton-Raphson algorithm based on the finite-volume method is employed for the optimization of the left and right lung resistivity values, making use of the voltage measurements retrieved from opposite current injections. In this preliminary study, 33 healthy volunteers were measured with the system during tidal respiration, yielding symmetric mean left and right lung resistivity values of (1205+/-163, 1200+/-165) (Omega cm). The system reproducibility was better than 2% for both within and between tests measurements, and no dependency between the reconstructed values and various anthropometric parameters was found.

Symmetrical distribution and rapid transbilayer movement of cholesterol in Mycoplasma gallisepticum membranes.

The exchange of cholesterol between [14C]cholesterol-labeled Mycoplasma gallisepticum cells and an excess of sonicated egg phosphatidylcholine/cholesterol vesicles (molar ratio of 0.9) was measured. More than 90% of the radioactive cholesterol underwent transfer from intact cells to the vesicles. The kinetics of the transfer was biphasic. About 50% of the radioactive cholesterol was exchanged with a half-time of about 4 h. The residual was exchanged at a slower rate with a half-time of about 9 h at 37 degrees C. Bovine serum albumin had a pronounced effect in enhancing both the fast and slow rates of cholesterol exchange, but did not affect the pool sizes significantly. The half-time for equilibration of the two pools in the presence of 2% albumin, calculated using a reversible two-pool method of analysis, was 6.2 h. The effect of albumin was also obtained with isolated membrane preparations and with cells treated with growth inhibitors, suggesting that this effect is independent of albumin preservation of cell viability. The rate enhancement of albumin was concentration dependent with maximal effects observed with greater than or equal to 2%, where the rates of exchange of both the rapidly and slowly exchanging pools were twice as fast. The mechanism by which albumin may affect the exchange rates is discussed.

Identification of a new member of the steroid hormone receptor superfamily that is activated by a peroxisome proliferator and fatty acids.

We have identified a novel member of the steroid hormone receptor superfamily by cDNA cloning from a human osteosarcoma SAOS-2/B10 cell library. Sequence analysis predicts a protein of 441 amino acids, which includes the conserved amino acid residues characteristic of the DNA- and ligand-binding domains of nuclear receptors. Amino acid sequence alignment and transcriptional activation experiments revealed that the new protein is closely related to the mouse peroxisome proliferator activated receptor. The overall homology is 62%, and the highest similarity is seen in the DNA- and ligand-binding domains, 86% and 71%, respectively. Northern blot analysis showed that in mature rats, the receptor is highly expressed in heart, kidney, and lung as a transcript of approximately 3500 nucleotides. In human cells, the size of the mRNA is approximately 4000 nucleotides. Transcription assays using hybrid receptors consisting of the ligand-binding domain of the new protein and the DNA-binding domain of the glucocorticoid receptor showed weak stimulation by the peroxisome proliferator activator WY14643, suggesting a relationship to that receptor. Similar stimulation was observed with arachidonic and oleic acid (100-250 microM).

Different pattern of alkaline phosphatase, osteopontin, and osteocalcin expression in developing rat bone visualized by in situ hybridization.

Alkaline phosphatase (AP), osteopontin (OP), and osteocalcin (OC) are expressed during osteoblastic differentiation. However, previous studies suggested differences in the timing and possibly the site of their expression. In this study we used in situ hybridization to follow the distribution of these osteoblastic markers during bone development. Frozen sections of neonatal rat long bones and calvariae were hybridized with 35S-labeled RNA probes complementary to the AP, OP, and OC mRNAs. Controls included sections hybridized with the sense (mRNA) probes or pretreated with RNase. Positive cells were identified in all areas of bone formation of the long bones and calvariae. Based on quantitative silver grain distribution and density, high levels of OP expression were present only in osteoblasts in close proximity to bone (one to two cell layers). OC expression, apparently at lower levels than OP, was also localized to osteoblasts in contact with bone. In contrast AP, which was expressed at lower levels than OP, was present in a large number of cells, including preosteoblasts that were many layers removed from the bone-forming surface. These findings are consistent with the asynchronous expression of phenotypically related genes and suggest that AP is an earlier differentiation marker than OP and OC during the formation of endochondral and membranous bone.

Expression of alpha v and beta 3 integrin subunits in rat osteoclasts in situ.

Recent findings suggest that the vitronectin receptor, a member of the integrin family, plays an important role in the attachment of osteoclasts to bone matrix. We report here the localization by in situ hybridization of the mRNA for the alpha and beta subunits of the vitronectin receptor in rat bone sections. To generate the rat-specific RNA probes used in this study, we cloned cDNA fragments of integrin chains alpha v, beta 3, and beta 5 by the polymerase chain reaction from rat cDNA. These fragments share 86-91% homology with the respective human sequences. In situ hybridization localized the alpha v and beta 3 mRNAs to regions undergoing extensive bone resorption. The histologic appearance and prestaining of bone sections for tartrate-resistant acid phosphatase (TRAP) indicated the presence of these mRNAs in osteoclasts. These observations support immunohistochemical findings that osteoclasts express high levels of the vitronectin receptor, confirm the identity of this receptor as integrin alpha v/beta 3, and suggest that osteoclasts may actively synthesize these molecules.

Biphasic effects of transforming growth factor-beta on the production of osteoclast-like cells in mouse bone marrow cultures: the role of prostaglandins in the generation of these cells.

Osteoclast-like multinucleated giant cells are induced in bone marrow cultures by 1,25-dihydroxyvitamin D3 and other agents. These cells resemble osteoclasts in their morphology, their ability to resorb bone, and the possession of calcitonin receptors. We report here a biphasic effect of transforming growth factor-beta (TGF beta) on the generation of these cells in mouse bone marrow cultures. At low concentrations (10-100 pg/ml) TGF beta enhanced 1,25-dihydroxyvitamin D3-dependent production of osteoclast-like cells, while at higher concentrations TGF beta was inhibitory. Complete inhibition was seen at 4 ng/ml. Antibodies directed against TGF beta significantly reduced the generation of osteoclast-like cells in 1,25-dihydroxyvitamin D3-treated cultures, indicating the contribution of endogenous TGF beta activity. TGF beta also enhanced the accumulation of prostaglandin E2 (PGE2) in a dose-dependent manner. Moreover, we found that the generation of these cells in response to 1,25-dihydroxyvitamin D3 was also dependent on PG accumulation, since it was inhibited by indomethacin (250 ng/ml), and this inhibition could be reversed by exogenous PGE2. It is, thus, suggested that PG activity, probably PGE2, mediates the enhancing effect of low TGF beta concentrations and is required for the generation of osteoclast-like cells in this system.

The effect of hemopoietic growth factors on the generation of osteoclast-like cells in mouse bone marrow cultures.

Multinucleated cells containing tartrate-resistant acid phosphatase were produced in mouse bone marrow cultures in response to 1,25-dihydroxyvitamin D3. These cells resemble osteoclasts in their morphology, possess receptors for calcitonin, and resorb bone in culture. The effects of several hemopoietic regulatory proteins on the generation of these cells were examined in this study. Interleukin-3, granulocyte-macrophage-stimulating factor (GMCSF), and macrophage-stimulating factor strongly inhibited generation of the tartrate-resistant acid phosphatase-containing multinucleated cells with approximate EC50 values of 3, 6, and 3 colony-forming units/ml, respectively. Granulocyte colony stimulating factor, interleukin-6, and leukemia inhibitory factor had no effect on the generation of these cells. In addition, we observed that the number of these cells was reduced when the bone marrow was plated at high cell density, and that this inhibitory effect was reversed by the addition of neutralizing antibodies directed against GMCSF. These findings suggest that GMCSF and other hemopoietic factors secreted by cells in the bone marrow regulate development of the osteoclast-like cells, possibly by diverting common precursor cells to alternate pathways.

Differential expression of insulin-like growth factor-I (IGF-I) and IGF-II messenger ribonucleic acid in growing rat bone.

Insulin-like growth factors (IGF-I and IGF-II) are among the most abundant growth factors found in bone. Although their local production has been implicated in growth and development, localization of the cells that express these proteins is not well documented. We have studied, by in situ hybridization, the temporal and spatial expression of IGF-I and IGF-II mRNA in rat long bones at different stages of postnatal bone development. In 2-day-old rats, IGF-II was highly expressed in cartilage and in the mesodermal structures that surround the bone. At later stages of bone development, the IGF-II signal decreased in intensity, but could still be detected in the growth plate of tibial bones at 3 and 5 weeks. At this stage, the IGF-II signal in the epiphyseal growth plate was unevenly distributed and was stronger in the periphery than in the center, where it was mainly concentrated in the germinal layer and in some, but not all, cartilage columns. IGF-I, on the other hand, was only faintly detected in the periosteum at the early cartilaginous stage of bone development. At later stages, IGF-I was strongly associated with regions of ossification in the trabecular bone of the metaphysis and epiphysis and along the endosteal and periosteal surfaces. Surprisingly, we did not detect at any time IGF-I mRNA in chondrocytes of the epiphyseal growth plate. These results suggest that in the rat, IGF-II plays a role in early development of bone and in the longitudinal growth of the epiphyseal plate. IGF-I is more closely associated with the osteogenic regions and does not replace the declining levels of IGF-II in the growth plate.

NER, a new member of the gene family encoding the human steroid hormone nuclear receptor.

NER, a new member of the steroid hormone nuclear receptor (NR)-encoding gene family, was isolated from a human osteosarcoma SAOS/B10 cell line cDNA library. NER codes for a polypeptide of 461 amino acids which contains the conserved sequences of the DNA-binding and ligand-binding domains of typical steroid hormone NR. It has highest homology with the retinoic acid receptors: 55% at the DNA-binding domain and 38-40% at the ligand-binding domain. A single transcript of 2.3 kb was detected in all cells and tissues tested. Although no ligand was identified for NER-I, its wide distribution may indicate that this novel steroid hormone NR may play a basic role in cell function.

Interobserver reliability in the interpretation of computed tomographic scans of stroke patients.

Interobserver reliability in interpretation of computed tomographic images was studied by six senior neurologists who independently evaluated on a standardized Stroke Data Bank form the brain lesions of 17 patients. The results analyzed with kappa statistics yielded moderate to substantial agreement on most items of interest including the stroke pathology and anatomy. In general, the levels of agreement were as high as previously reported for the diagnosis of the mechanism of the stroke, and much higher than on many stroke history items and items of neurologic examination. Excellent agreement was obtained for the detection of infarcts and intracerebral hemorrhage, and substantial agreement was obtained on whether the computed tomographic images were normal or indicative of small deep infarcts, superficial and deep infarcts, and aneurysms. The level of agreement on anatomy of the lesions was best for the frontal, parietal, and temporal lobes, putamen, cerebellum, and subarachnoid space. Implications for clinical research and diagnosis are discussed.

Interobserver variability in the assessment of neurologic history and examination in the Stroke Data Bank.

Interobserver reliability in obtaining neurologic histories and examinations was investigated among neurologists collaborating in the Stroke Data Bank (SDB). Seventeen in-hospital stroke patients were examined by six neurologists experienced in stroke over the course of three days. Patients were examined twice a day for two successive days, with each patient seen by four different neurologists. Data were recorded on SDB forms, according to definitions and procedures established for the SDB. Percent agreement and kappa coefficients were calculated to assess the levels of agreement for each item. Important differences in levels of agreement were found among items on both neurologic history and examination. Agreement among neurologists was higher for neurologic examination than for history. Patterns of agreement for items with low prevalence or with numerous unknown ratings are discussed. Improvement in interobserver agreement due to data editing for intra-observer consistency was shown.

Interobserver agreement in the diagnosis of stroke type.

Interobserver agreement is essential to the reliability of clinical data from cooperative studies and provides the foundation for applying research results to clinical practice. In the Stroke Data Bank, a large cooperative study of stroke, we sought to establish the reliability of a key aspect of stroke diagnosis: the mechanism of stroke. Seventeen patients were evaluated by six neurologists. Interobserver agreement was measured when diagnosis was based on patient history and neurologic examination only, as well as when it was based on results of a completed workup, including a computed tomographic scan. Initial clinical impressions, based solely on history and one neurologic examination, were fairly reliable in establishing the mechanism of stroke (ie, distinguishing among infarcts, subarachnoid hemorrhages, and parenchymatous hemorrhages). Classification into one of nine stroke subtypes was substantially reliable when diagnoses were based on a completed workup. Compared with previous findings for the same physicians and patients, the diagnosis of stroke type was generally more reliable than individual signs and symptoms. These results suggest that multicentered studies can rely on the independent diagnostic choices of several physicians when common definitions are employed and data from a completed workup are available. Furthermore, reliability may be less for individual measurements such as signs or symptoms than for more-complex judgments such as diagnoses.

Impact of court monitoring on the adjudication of driving while intoxicated (DWI).

Court monitoring of driving while intoxicated (DWI) cases is a labor-intensive effort conducted by over 300 concerned citizen groups across the United States. The present study assessed the impact of court monitoring by analyzing the difference in court dispositions (guilty, not guilty, and dismissed) and case outcomes (jail, fine, and license suspension) between monitored cases and non-monitored cases. The data base for this study consisted of all 9,137 DWI arrests made in the state of Maine in one calendar year. The results demonstrated that court monitoring is an effective tool in affecting the adjudication process. In the presence of court monitors the conviction rates of DWI offenders were higher and their case dismissal rates were lower than those of drivers not court-monitored. Furthermore, once convicted, the likelihood of a jail sentence was higher and the length of the jail sentence was longer for court-monitored DWI drivers than for non-monitored drivers. Monitoring impact was most pronounced for first-time offenders with BAC levels of .10-.11, and those refusing the BAC test.

Drinking and driving of pub patrons in Israel.

A chance sample of people exiting pubs in Israel were interviewed and their blood alcohol concentration (BAC) was measured with a portable breathalizer. Approximately 50% of the people intended to drive away themselves, while 50% were driven by others. People's decision whether or not to drive was unrelated to their BAC and to the number of drinks they reportedly had, and only marginally related to whether or not they felt drunk. Thirty percent of those who felt drunk still intended to drive. Although three-quarters of the respondents felt there is a driving and drinking problem in Israel, their knowledge about the effects of alcohol and the number of drinks they need to consume in order to get drunk reflected an alarming ignorance. The results demonstrate a dangerous trend in alcohol consumption that is not coupled with adequate specific knowledge about alcohol's effects.

Demographic and socioeconomic correlates of safety belt use.

This study analyzed the relationship between safety belt use rates--as measured by observational surveys at preselected sites--and demographic and socioeconomic characteristics--as reflected by the U.S. Census Bureau data for the sites. The results showed consistent and moderately high associations between observed safety belt use rates and socioeconomic status indicators, primarily home value. Once redundancies among variables were removed, other variables that contributed significantly to explaining differences between high- and low-belt use sites were the percentage of elderly people (55+ years old) and the mix of blue and white collar workers. Sites having high safety belt use rates had higher average home values, a higher percentage of elderly people, and a lower percentage of blue collar workers than sites having low use rates. Simple correlations with belt use rates were also obtained for race, marital status, presence of children in household, education, and income.

Self-reports of safe driving behaviors in relationship to sex, age, education and income in the US adult driving population.

This study analyzed the data of a health and safety survey conducted on a representative sample of the adult driving population. The analysis focused on the relationships between self-reported safe driving behaviors (including belt use, observing speed limits, and abstaining from drinking and driving), and demographic characteristics (including sex, age, education and income). The results showed that the three behaviors are quite independent of each other, and, contrary to some stereotypes, there is no single high-risk group that is most likely to violate all three safe driving behaviors. The only consistent effect was that of sex: women reported higher observance rates of all three behaviors. Reported use of safety belts increases with age and education for both men and women. However while for women the reported use increases with income, for males the reported use does not change with income. Complete avoidance of drinking and driving was reported by most drivers in all groups, and the high rates hardly varied across the different age, education, and income groups. The number of people who reported that they observe the speed limit all the time increased with age, but decreased with increasing education and income. The results have implications for identifying violation-specific high-risk groups, and stressing different factors for each.

Trends in safe driving behaviors and in relation to trends in health maintenance behaviors in the USA: 1985-1995.

Specific health and safe driving behaviors of the American adult population during the period 1985-1995, were examined for trends and for consistencies in observing them. The data base consisted of the results of annual surveys conducted on representative samples of 1250 people of the US adult population. Two indices were developed: a Health Index (HI) and a Safety Index (SI). The Health Index reflects the level of practice of six health and disease preventing behaviors (in order of decreasing importance: not smoking, frequent exercises, avoiding fat foods, having an annual blood pressure test, avoiding high-cholesterol foods, and having an annual dental exam). The Safety Index reflects the level of practice of three safe driving behaviors (in order of decreasing importance: wearing safety belts, avoiding drinking and driving, and observing the speed limit). Only a weak association was found among the individual safe driving behaviors, among the individual health maintenance behaviors, and between the two sets of behaviors. Over the 11-year study period the change in the Health Index has been practically and statistically insignificant, whereas the change in the Safety Index was both statistically and practically significant. The small improvement in the Safety Index actually masked a complex pattern of changes in safe driving habits. The three component Safety Index behaviors did not change in the same manner over the 11-year period. The greatest and most consistent increase was in the use of safety belts, with the reported percent who use it all the time increasing from 41.5% in 1985 to 74.1% in 1995 (an increase of 80%). There was also a consistent positive trend in refraining from drinking and driving, but the overall improvement was less dramatic than that reported for use of safety belts: from 71.6% reporting they never drink and drive in 1985 to 79.1% in 1995 (an increase of 10%). Still, it is noteworthy that by 1995 nearly 80% of the people reported they never drink and drive. Finally, obeying the speed limit did not improve over the 11-year period.

The visual and driving performance of monocular and binocular heavy-duty truck drivers.

This study compared the performance of 40 monocular and 40 binocular tractor-trailer drivers on measures of both visual and driving performance. On the visual measures, the mononuclear drivers were significantly deficient in contrast sensitivity, visual acuity under low illumination and glare, and binocular depth perception. They were not significantly deficient in static or dynamic visual acuity, visual field of individual eyes, or glare recovery. Driving measures of visual search, lane keeping, clearance judgment, gap judgment, hazard detection, and information recognition showed no differences between monocular and binocular drivers. Monocular drives were poorer than binocular drivers only in sign reading distance in both daytime and nighttime driving. This decrement correlated significantly with the binocular depth perception measure. There were large individual differences within each group for most of the visual and driving performance measures. It was concluded that monocular drivers have some significant reductions in selected visual capabilities and in certain driving functions dependent on these abilities, compared with binocular drivers. However, monocular drivers are not significantly worse than binocular drivers in the safety of most day-to-day driving functions. Implications of these findings and the large individual differences within each group are discussed.

Thoracoscopic upper thoracic sympathectomy for primary palmar hyperhidrosis in children and adolescents.

After 20 years of experience with the "open" transaxillary approach, the authors are presently performing the thoracoscopic technique for upper thoracic sympathectomy in severe primary hyperhidrosis. During a period of 14 months, 23 operations were performed and 22 patients had immediate and permanent relief of palmar sweating. The immediate postoperative course was uneventful in all cases. Hospitalization was short, and all patients returned to school and full activity 3 to 5 days after operation. These initial results compare favorably to the "open" method and, pending further experience, are actually better in terms of less pain, early discharge, quicker return to normal activity, and a smaller, less conspicuous scar.