Are crash causation studies the best way to understand system failures - Who can we blame?

The search for common and serious single causes of road crashes naturally leads to a concentration on the road user. This is supported by a legal framework in the search for the main cause and the suspect for this cause. In prevention, we havefor decades been more inclined to look for systematic improvements of all elements of the road transport system, and we direct the recommendations for actions towards system designers, organizations, products and services. In this paper the discussion about causation and prevention is broadened in the light of Vision Zero and its approach to prevention of serious and fatal injuries. We also discuss the Swedish judicial system and why the prevention approach has not been legislated or even generally accepted. Occupational health and safety legislation and road rules are compared, as well as how sustainability practices and reporting are tools to apply prevention where organizations have a natural sphere of influence that could mitigate deaths and serious injuries within value chains. It is recommended that we stop using the term causation as it is only directing actions in one direction. There is a risk that the focus on causation, in particular single causes, will deviate actions away from robust prevention countermeasures such as increased seat belt use, relevant speed limits, and well functioning roundabouts and median barriers. Furthermore, there is also a risk that important preventative actions from organizations are overlooked.

Systematic review of the cardiovascular effects of occupational noise

BACKGROUND

Cross-sectional studies of occupational noise and cardiovascular effects show an association between noise and hypertension but for coronary heart disease or other cardiovascular diseases (CVDs) the evidence is not convincing.

AIMS

To assess possible associations between occupational noise exposure and the risk for cardiovascular effects in follow-up studies published after 1999.

METHODS

We performed a systematic critical literature review of original articles from key literature databases of associations between workplace noise and health. The studies were identified by search in Ovid Medline, Ovid Embase, Web of Science, Scopus and ProQuest Health and Safety Sciences Abstracts. We selected prospective studies of adequate quality with a measure of association between occupational noise exposure and cardiovascular health for the meta-analysis.

RESULTS

Twelve papers, all prospective and mostly with high quality but with methodological shortcomings in exposure assessment, were included in the review and meta-analysis. Exposure to noise at work was consistently positively associated with hypertension [Hazard ratio (HR) = 1.68; 95% confidence interval (CI) 1.10-2.57] and CVD [relative risk (RR) = 1.34; 95% CI 1.15-1.56]. In addition, we found a trivial effect of noise exposure on CVD mortality (HR = 1.12; 95% CI 1.02-1.24).

CONCLUSIONS

Occupational noise exposure is strongly associated with hypertension. For other cardiovascular effects, this meta-analysis suggests a weak association, but the evidence is limited. More longitudinal studies on the effects of occupational noise on the cardiovascular system are warranted.

Simplified risk assessment of noise induced hearing loss by means of 2 spreadsheet models

OBJECTIVES

The objective of this study has been to test 2 spreadsheet models to compare the observed with the expected hearing loss for a Norwegian reference population.

MATERIAL AND METHODS

The prevalence rates of the Norwegian and the National Institute for Occupational Safety and Health (NIOSH) definitions of hearing outcomes were calculated in terms of sex and age, 20-64 years old, for a screened (with no occupational noise exposure) (N = 18 858) and unscreened (N = 38 333) Norwegian reference population from the Nord-Trøndelag Hearing Loss Study (NTHLS). Based on the prevalence rates, 2 different spreadsheet models were constructed in order to compare the prevalence rates of various groups of workers with the expected rates. The spreadsheets were then tested on 10 different occupational groups with varying degrees of hearing loss as compared to a reference population.

RESULTS

Hearing of office workers, train drivers, conductors and teachers differed little from the screened reference values based on the Norwegian and the NIOSH criterion. The construction workers, miners, farmers and military had an impaired hearing and railway maintenance workers and bus drivers had a mildly impaired hearing. The spreadsheet models give a valid assessment of the hearing loss.

CONCLUSIONS

The use of spreadsheet models to compare hearing in occupational groups with that of a reference population is a simple and quick method. The results are in line with comparable hearing thresholds, and allow for significance testing. The method is believed to be useful for occupational health services in the assessment of risk of noise induced hearing loss (NIHL) and the preventive potential in groups of noise-exposed workers. Int J Occup Med Environ Health 2016;29(6):991-999.

Occupational noise exposure, hearing loss, and notched audiograms in the HUNT Nord-Trøndelag hearing loss study, 1996-1998

Objectives/Hypothesis

To study the prevalence and usefulness of audiometric notches in the diagnosis of noise‐induced hearing loss (NIHL).

Study Design

Audiograms and data on noise exposure from 23,297 men and 26,477 women, aged 20 to 101 years, from the Nord‐Trøndelag Hearing Loss Study, 1996–1998.

Methods

The prevalence of four types of audiometric notches (Coles, Hoffman, Wilson) and 4 kHz notch were computed in relation to occupational noise exposure, age, sex, and report of recurrent ear infections.

Results

The prevalence of notches in the 3 to 6 kHz range (Wilson, Hoffman, and Coles) ranged from 50% to 60% in subjects without occupational noise exposure, and 60% to 70% in the most occupationally noise‐exposed men. The differences were statistically significant only for bilateral notches. For 4 kHz notches, the prevalence varied from 25% in occupationally nonexposed to 35% in the most occupationally exposed men, and the differences were statistically significant for both bilateral and unilateral notches. For women, the prevalence of notches was lower than in men, especially for 4 kHz notches, and the differences between occupationally noise exposed and nonexposed were smaller. Recreational exposure to high music was not associated with notched audiograms.

Conclusions

The detection of bilateral notches and unilateral 4 kHz notches is of some value in diagnosing NIHL, especially in men.

Level of Evidence

4 Laryngoscope, 127:1442–1450, 2017

Associations between long commutes and subjective health complaints among railway workers in Norway

Commuting is an important aspect of daily life for many employees, but there is little knowledge of how this affects individual commuters' health and well-being. The authors investigated the relationship between commuting and subjective health complaints, using data from a web-based questionnaire. In a sample of 2126 railway employees, 644 (30.3%) had long commute times. A 29-item inventory was used to measure the number and degree of the subjective health complaints. Those who commuted 60 min or more each way were characterized by significantly higher numbers and degrees of subjective health complaints compared with their peers with short commutes. The mean number of complaints was 7.5 among the former group and 6.4 for the latter group (p = 0.009). In a regression model, in which the authors controlled for age, gender, education, self-rated health, and coping, the employees with long commutes reported more complaints than those with short commutes. Significant associations were found between those with long commutes and the number and degree of incidences of self-reported musculoskeletal pain, pseudo-neurologic complaints, and gastrointestinal problems. Commuters who had had long commutes for more than 10 years reported more gastrointestinal and musculoskeletal complaints than those with long commutes for less than 2 years. Also, commuters with long commutes spent less time with their families and leisure activities compared with those with short commutes. The authors conclude that the association between long commute times and higher levels of subjective health complaints should attract the attention of transport planners, employers, and public health policymaker.

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Long commuters reported more subjective health symptoms than short commuters.

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Musculoskeletal, gastrointestinal and pseudo neurological complaints were most frequent.

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Long commuters spent less time with their families and on leisure activities than short commuters.

Noise-induced hearing loss in a longitudinal study of Norwegian railway workers

OBJECTIVE

The aim of this study was to analyse longitudinal data to assess the risk of noise-induced hearing loss (NIHL) in Norwegian railway workers.

DESIGN

Longitudinal.

SETTING

A major Norwegian railway company.

METHODS

We examined data from the first and last audiograms for the period 1991-2014, from 9640 railway workers with varying occupational noise exposure and with an average observation period of 10 years. The course of hearing acuity in seven groups of railway workers (train drivers, conductors, bus drivers, traffic controllers, train maintenance workers, track maintenance workers and others) were compared with each other and with ISO standards (ISO 1999).

RESULTS

The change in hearing threshold during the observation period was 2-3 dB in the 0.5-4 kHz range and 6-7 dB in the 3-6 kHz range adjusted for age and sex, for all occupational groups, which is slightly less than expected (8 dB) according to ISO 1999.

CONCLUSIONS

The risk of NIHL in Norwegian railway workers during the period 1991-2014 has been negligible.

Cardiovascular risk factors and hearing loss: The HUNT study

OBJECTIVE

The purpose of the present paper was to examine the association between prospectively and cross-sectionally assessed cardiovascular risk factors and hearing loss.

DESIGN

Hearing was assessed by pure-tone average thresholds at low (0.25-0.5 kHz), middle (1-2 kHz), and high (3-8 kHz) frequencies. Self-reported or measured cardiovascular risk factors were assessed both 11 years before and simultaneously with the audiometric assessment. Cardiovascular risk factors were smoking, alcohol use, physical inactivity, waist circumference, body mass index, resting heart rate, blood pressure, triglycerides, total serum cholesterol, LDL cholesterol, HDL cholesterol, and diabetes.

STUDY SAMPLE

A population-based cohort of 31 547 subjects.

RESULTS

After adjustment for age, sex, level of education, income, recurrent ear infections, and noise exposure, risk factors associated with poorer hearing sensitivity were smoking, diabetes, physical inactivity, resting heart rate, and waist circumference. Smoking was only associated with hearing loss at high frequencies. The effects were very small, in combination explaining only 0.2-0.4% of the variance in addition to the component explained by age and the other cofactors.

CONCLUSION

This cohort study indicates that, although many cardiovascular risk factors are associated with hearing loss, the effects are small and of doubtful clinical relevance.

Accreditation of occupational health services in Norway

Background

In 2010, an accreditation system for occupational health services (OHS) in Norway was implemented.

Aims

To examine OHS experiences of the accreditation system in Norway 4 years after its implementation.

Methods

A web-based questionnaire was sent to all accredited OHS asking about their experiences with the accreditation system. Responses were compared with a similar survey conducted in 2011.

Results

The response rate was 76% (173/228). OHS reported that the most common changes they had had to make to achieve accreditation were: improvement of their quality assurance system (53%), a plan for competence development (44%) and increased staffing in occupational hygiene (36%) and occupational medicine (28%). The OHS attributed improved quality in their own OHS (56%) and in OHS in Norway (47%), to the accreditation process.

Conclusions

The accreditation system was well accepted by OHS, who reported that it had improved the quality of their OHS and of OHS in Norway. The results are similar to the findings of a 2011 survey.

Effectiveness of low speed autonomous emergency braking in real-world rear-end crashes

This study set out to evaluate the effectiveness of low speed autonomous emergency braking (AEB) technology in current model passenger vehicles, based on real-world crash experience. The validating vehicle safety through meta-analysis (VVSMA) group comprising a collaboration of government, industry consumer organisations and researchers, pooled data from a number of countries using a standard analysis format and the established MUND approach. Induced exposure methods were adopted to control for any extraneous effects. The findings showed a 38 percent overall reduction in rear-end crashes for vehicles fitted with AEB compared to a comparison sample of similar vehicles. There was no statistical evidence of any difference in effect between urban (≤60 km/h) and rural (>60 km/h) speed zones. Areas requiring further research were identified and widespread fitment through the vehicle fleet is recommended.

Duties performed by occupational physicians in Norway

BACKGROUND

Occupational health care for all is a global aim but has not yet been achieved. Further development should be based on knowledge of specific alternative models of occupational health services (OHS). Little is published on different OHS models and work as a physician in these services.

AIMS

To describe duties for Norwegian physicians working in two different OHS models: internal and external. In the internal model, the physician is employed in an OHS located at the company served, whereas in the external model, OHS time is shared between several companies and the physician is often located outside the companies.

METHODS

A web-based survey was sent to all members of the Norwegian Occupational Medicine Association.

RESULTS

There were 206 responses (response rate of 73%). Only those working as OHS physicians were included (54%). Physicians in external OHS performed individual health examinations to a greater extent, otherwise few differences between physicians working in internal and external OHS were found. Changes in the priority of the physicians' duties through a period of 20 years seem to be related to changes in legislation and official guidelines related to OHS practice.

CONCLUSIONS

In this study, OHS physicians in Norway performed a large number of individual-based health examinations but this was seen more in the external OHS model. Otherwise physicians' duties had similar priority in the external and internal models. Legislation and official guidelines seem to be of major importance to the duties performed.

A cross-sectional study of hearing thresholds among 4627 Norwegian train and track maintenance workers

OBJECTIVE

Railway workers performing maintenance work of trains and tracks could be at risk of developing noise-induced hearing loss, since they are exposed to noise levels of 75-90 dB(A) with peak exposures of 130-140 dB(C). The objective was to make a risk assessment by comparing the hearing thresholds among train and track maintenance workers with a reference group not exposed to noise and reference values from the ISO 1999.

DESIGN

Cross-sectional.

SETTING

A major Norwegian railway company.

PARTICIPANTS

1897 and 2730 male train and track maintenance workers, respectively, all exposed to noise, and 2872 male railway traffic controllers and office workers not exposed to noise.

OUTCOME MEASURES

The primary outcome was the hearing threshold (pure tone audiometry, frequencies from 0.5 to 8 kHz), and the secondary outcome was the prevalence of audiometric notches (Coles notch) of the most recent audiogram.

RESULTS

Train and track maintenance workers aged 45 years or older had a small mean hearing loss in the 3-6 kHz area of 3-5 dB. The hearing loss was less among workers younger than 45 years. Audiometric notches were slightly more prevalent among the noise exposed (59-64%) group compared with controls (49%) for all age groups. They may therefore be a sensitive measure in disclosing an early hearing loss at a group level.

CONCLUSIONS

Train and track maintenance workers aged 45 years or older, on average, have a slightly greater hearing loss and more audiometric notches compared with reference groups not exposed to noise. Younger (<45 years) workers have hearing thresholds comparable to the controls.

Work-related post-traumatic stress disorder

BACKGROUND

Work-related post-traumatic stress disorder (PTSD) is an important condition encountered by many occupational health practitioners.

AIMS

To carry out an in-depth review of the research on occupational groups that are at particular risk of developing work-related PTSD.

METHODS

A literature search was conducted in the databases OVID MEDLINE, OVID Embase, Ovid PsycINFO, ISI Web of Science and CSA Health and Safety Science Abstracts.

RESULTS

Professionals such as police officers, firefighters and ambulance personnel often experience incidents that satisfy the stressor criterion for the PTSD diagnosis. Other professional groups such as health care professionals, train drivers, divers, journalists, sailors and employees in bank, post offices or in stores may also be subjected to work-related traumatic events. Work-related PTSD usually diminishes with time.

CONCLUSIONS

Mental health problems prior to the traumatic event and weak social support increase the risk of PTSD. Prevention of work-related PTSD includes a sound organizational and psychosocial work environment, systematic training of employees, social support from colleagues and managers and a proper follow-up of employees after a critical event.

Hearing status among Norwegian train drivers and train conductors

Background

There is a general perception that train drivers and conductors may be at increased risk of developing noise-induced hearing loss.

Aims

To study job-related hearing loss among train drivers and train conductors.

Methods

Audiograms from train drivers and train conductors were obtained from the medical records of the occupational health service of the major Norwegian railway company. The results were compared with audiograms from an internal control group of railway workers and an external reference group of people not occupationally exposed to noise. The monaural hearing threshold level at 4kHz, the mean binaural value at 3, 4 and 6kHz and the prevalence of audiometric notches (≥25 dB at 4kHz) were used for comparison.

Results

Audiograms were available for 1567 drivers, 1565 conductors, 4029 railway worker controls and 15 012 people not occupationally exposed to noise. No difference in hearing level or prevalence of audiometric notches was found between study groups after adjusting for age and gender.

Conclusions

Norwegian train drivers and conductors have normal hearing threshold levels comparable with those in non-exposed groups.

Stimulation of IL-6 Cytokines in Fibroblasts by Toll-like Receptors 2

The osteotropic interleukin-6 (IL-6) types of cytokines IL-6, IL-11, and leukemia inhibitory factor (LIF), but not oncostatin M, are expressed by human gingival fibroblasts, and their expressions are regulated by IL-1 and tumor necrosis factor-α (TNF-α). In the present study, we investigated whether signaling through Toll-like receptor 2 (TLR2) can affect the expression of these cytokines in human gingival fibroblasts. Lipopolysac-charide (LPS) from P. gingivalis was found to stimulate IL-6 and LIF mRNA and protein, but not IL-11 or OSM mRNA. Using two synthetic ligands acting specifically at TLR2 and siRNA knockdown of TLR2, we demonstrated the important role of TLR2 in the stimulation of IL-6 and LIF in gingival fibroblasts. Analysis of these data suggests that signaling through the innate immune system controls the expression of osteotropic cytokines in human gingival fibroblasts.

The properties of Safety Performance Indicators in target setting, projections and safety design of the road transport system

Road traffic Safety Performance Indicators (SPIs) are becoming increasingly used as an instrument for the planning and monitoring of safety progress. SPIs form an intermediate step between actions and final outcome in terms of casualties in road crashes. It is understood that SPIs are closely related to outcome; and that it is also possible to use them in calculations and predictions of both actions and final outcome. In the present study, it was found that some of the properties assigned to SPIs could be questioned. An assumption of linearity between SPIs and final outcome was partly rejected. It was also found that 100% fulfillment of a set of SPIs could lead to very low mortality, demonstrating the importance of handling SPIs simultaneously.

"Inclusive Working Life" in Norway--experience from "Models of Good Practice" enterprises

AIM

To determine whether enterprises belonging to the Bank of Models of Good Practice were more successful than average Norwegian enterprises in the reduction of sickness absence, promotion of early return to work, and prevention of early retirement.

METHODS

In 2004 we selected 86 enterprises with a total of approximately 90000 employees from the Inclusive Working Life (IWL) Bank of Models of Good Practice. One representative of workers and one of management from each enterprise received a questionnaire on the aims, organization, and the results of the IWL program by mail. Data on sickness absence, use of early retirement, and disability retirement in the 2000-2004 period were collected from the National Insurance Registry. Data on comparable enterprises were obtained from the National Bureau of Statistics.

RESULTS

The response rate was 65%. Although the IWL campaign was directed at reducing sickness absence, preventing early retirement, and promoting employment of the functionally impaired, most attention was paid to reducing sickness absence. Sickness absence rate in Models of Good Practice enterprises (8.2%) was higher than in comparable enterprises that were not part of the Models of Good Practice (6.9%). Implementation of many IWL activities, empowerment and involvement of employees, and good cooperation with the occupational health service were associated with a lower rate of sickness absence. On average, 0.7% new employees per year received disability pension, which is a significantly lower percentage than expected on the basis of the rate of 1.3% per year in comparable enterprises. Frequent use of disability pensioning was associated with high rate of sickness absence and having many employees older than 50 years. On average, 0.4% employees per year received early retirement compensation, which was expected on the basis of national estimates. Frequent use of early retirement was associated with having many employees older than 50 years.

CONCLUSION

Models of Good Practice enterprises had a higher than expected sickness absence rate. This indicates that it is difficult to identify Models of Good Practice enterprises and that they cannot be treated as role model enterprises. Good cooperation with the occupational health service and the empowerment and involvement of the employees is associated with a low sickness absence rate.

Efficacy and side effects of ‘swinging eyelid’ orbital decompression in Graves' orbitopathy: a proposal for standardized evaluation of diplopia

OBJECTIVES

To evaluate the efficacy and side effects of 'swinging eyelid' orbital decompression in patients with Graves' orbitopathy (GO). To calculate the incidence of postoperative new-onset diplopia (NOD) using a newly proposed scoring system for diplopia.

METHODS

We reviewed the clinical data on proptosis, visual acuity, and diplopia in 104 consecutive patients (198 orbits) with GO, who underwent orbital decompression. A combined lateral canthal and inferior fornix incision ('swinging eyelid' approach) was used for removal of the medial wall, the orbital floor and, if indicated, the lateral wall. Indications for surgery were disfiguring/congestive GO (DGO) in 79 patients (149 orbits) and compressive optic neuropathy (CON) in 25 patients (49 orbits). Diplopia was scored according to four grades. In both groups, the incidence of new-onset (continuous) diplopia (NOD), deterioration of diplopia (DOD), and improvement of diplopia (IOD) were calculated, using strictly defined criteria. Our data on NOD were compared to those from other series, after recalculation according to our criteria.

RESULTS

The mean proptosis reduction was 4.6 mm (range 0-9.5 mm) after three-wall decompression (95 patients, 180 orbits) vs 3.1 mm (range 0-7 mm) after two-wall decompression (nine patients, 18 orbits). The visual acuity improved in 98% of the patients with CON. In patients with DGO, NOD occurred in 14%. In patients with CON, NOD was not observed, but DOD occurred in 41%. Our data compare favourably to the reported incidence of NOD after either transantral or transnasal decompression.

CONCLUSIONS

"Swinging eyelid' orbital decompression is efficacious for proptosis reduction as well as for optic nerve decompression. A scoring system for standardized evaluation of diplopia is proposed.

Trends and development of occupational health services in Norway

Occupational Health Services (OHS) in Norway cover approximately 1.2 million employees, equivalent to 60% of the total work force. They employ nurses (800), physicians (500), physiotherapists (360), safety engineers (400), psychologists (30) and others (400), a total of 2500 full time employmancy. The average cost of the OHS amounts to 150 euros per employee, a total cost of 180 million euros per year. In 1998, the OHS in Norway were evaluated. The evaluation, initiated by the Ministry, revealed that although 80% of the enterprises are fairly satisfied with their OHS, there is still much to be improved, in particular quality development and customer focus. By 2000 the National Practice Guidelines. ("Good OHS") were developed as a joint effort of the professional OHS associations, representatives from the social partners and the NIOH. These guidelines have been evaluated and well accepted by the OHS. Last year the Ministry of Labour appointed an advisory group of experts on OHS. The group was asked to examine: the "branch provision" on obligatory OHS and the availability of health resources; the legislation on OHS tasks; the quality improvement of OHS; and the OHS in small enterprises The report was ready in May 2001 stating that the OHS may be a useful contributor to the improvement of the health, environment and safety in enterprises and included the following recommendations: to establish the OHS for all within 10 years and to ratify relevant ILO convention; to develop a certification system for the OHS; to ensure financial public support of the OHS for the small enterprises; and to expand the OH hospital departments as important supportive agents for the OHS. The report will be a background document for the revision process of the Work Environment Act to be soon put into force.

Functional and molecular analysis of transient voltage-dependent K+ currents in rat hippocampal granule cells

1. We have investigated voltage-dependent outward K+ currents of dentate granule cells (DGCs) in acute brain slices from young and adult rats using nucleated and outside-out patch recordings. 2. In adult DGCs, the outward current pattern was dominated by a transient K+ current component. One portion of this current (approximately 60%) was blocked by micromolar concentrations of tetraethylammonium (TEA; IC50 42 microM) and BDS-I, a specific blocker of Kv3.4 subunits (2.5 microM). A second component was insensitive to tetraethylammonium (10 mM) and BDS-I. The transient outward current could be completely blocked by 4-aminopyridine (IC50 296 microM). 3. The TEA- and BDS-I-sensitive and the TEA-resistant current components were isolated pharmacologically. The current component that was blocked by BDS-I and TEA showed a depolarized threshold of activation (approximately -30 mV) reminiscent of Kv3.4 subunits, while the current component resistant to TEA activated at more hyperpolarized potentials (approximately -60 mV). 4. In nucleated patches obtained by placing the patch pipette adjacent to the apical dendrite, only small Na+ currents and small BDS-I-sensitive transient currents were detected. Nucleated patches obtained from either the cell soma (see above) or the axon hillock showed significantly larger amplitude Na+ currents as well as larger BDS-I-sensitive currents, indicating that this current was predominantly localized within the axosomatic compartment. This result was in good agreement with the distribution of Kv3.4 protein as determined by immunohistochemistry. 5. Current-clamp as well as mock action potential-clamp experiments revealed that the BDS-sensitive current component contributes to action potential repolarization. 6. A comparison of the two age groups (4-10 days and 60-100 days) revealed a marked developmental up-regulation of the BDS-I-sensitive component. These functional changes are paralleled by a developmental increase in Kv3.4 mRNA expression determined by quantitative real-time RT-PCR, as well as a pronounced up-regulation of Kv3.4 on the protein level determined by immunohistochemistry. 7. These functional and molecular results argue that Kv3.4 channels located predominantly in the axosomatic compartment underlie a transient K+ current in adult DGCs, and that these channels are functionally important for regulating spike repolarization. The marked developmental regulation suggests an important role of Kv3.4 in neuronal maturation.

Vasoactive intestinal peptide regulates osteoclast activity via specific binding sites on both osteoclasts and osteoblasts

Clinical and experimental observations, together with immunohistochemical findings, suggest that neuro-osteogenic interactions may occur in the skeleton. In this study, we have examined the effect of vasoactive intestinal peptide (VIP), one of the neuropeptides present in bone, on the activity of the bone-resorbing osteoclast. Effects on bone resorption were assessed by counting the number of pits formed by rat osteoclasts incubated on devitalized slices of bovine cortical bone. Under conditions with an initially sparse density of stromal cells/osteoblasts, VIP caused a rapid cytoplasmic contraction and decreased motility of osteoclasts. This was coupled with a decrease in the number of resorption lacunae and a decrease in the total area resorbed by the osteoclasts in 48-h cultures. Time-course experiments revealed that the inhibitory effects on contraction and motility were transient and that the cells gradually regained their activity, such that, when culture time was prolonged to 120 h, a stimulatory effect by VIP on bone resorption was observed. When osteoclasts were incubated on bone slices, in the presence of an initially large number of stromal cells/osteoblasts, VIP treatment increased the number of resorption pits and total bone area resorbed in 48-h cultures. Using atomic force microscopy, we provide direct evidence that both osteoclasts and stromal cells/osteoblasts bind VIP. Also, VIP was shown to cause a rapid rise of intracellular calcium in osteoclasts and in a proportion (20%) of stromal cells/osteoblasts. Taken together, these data suggest that differentiated osteoclasts are equipped with receptors for VIP that are linked to a transient inhibition of osteoclast activity and, in addition, that stromal cells/osteoblasts have VIP receptors coupled to a delayed stimulation of osteoclastic resorption.

Prevalence of hepatitis A, B, C, and E antibody in flying airline personnel

OBJECTIVES

The aim of the study was to detect the prevalence of antibodies against hepatitis A, B, C, and E viruses in flying airline personnel, and to determine the necessity of hepatitis A vaccination to prevent such infections related to occupational exposure.

METHODS

Antibodies against hepatitis A (HAV), B (HBV), C (HVC), and E (HEV) were tested for using standard enzyme immunoassay in airline personnel, 208 flying personnel, 199 ground crew, and 204 employees from companies not involved in travel activities.

RESULTS

Prevalence of antibodies against HAV was less than 5% in each group, and there was no significant difference between the three groups. Prevalence of antibodies against HEV was significantly higher in flying personnel (3.4%) than in the control groups. Prevalence of antibodies against HBV and HCV was low in each of the three groups and there were no differences between the three groups.

CONCLUSIONS

Infection with HAV, HBV and HCV does not seem to represent an occupational hazard to flying personnel. It is possible that flying personnel are exposed to infection with HEV, however, presently no vaccine is available.

Synaptic plasticity in the human dentate gyrus

Activity-dependent plasticity is a fundamental feature of most CNS synapses and is thought to be a synaptic correlate of memory in rodents. In humans, NMDA receptors have been linked to verbal memory processes, but it is unclear whether NMDA receptor-dependent synaptic plasticity can be recruited for information storage in the human CNS. Here we have for the first time analyzed different forms of synaptic plasticity in human hippocampus. In human subjects who show a morphologically intact hippocampus that is not the primary seizure focus, NMDA receptor-dependent long-term potentiation (LTP) and forskolin-induced long-lasting potentiation are readily induced at the perforant path-dentate gyrus synapse. In this group, long-term potentiation could be partially depotentiated by low-frequency stimulation. Because patients with a hippocampal seizure focus showed a marked reduction in verbal memory performance in previous studies, we asked whether synaptic plasticity is similarly affected by the presence of a hippocampal primary seizure focus. We found that the amount of potentiation induced by high-frequency stimulation or perfusion of forskolin is dramatically reduced in this patient group. In addition, low-frequency stimulation is not effective in inducing synaptic depression. In summary, we show that activity-dependent synaptic plasticity with properties similar to the rodent is available for information storage in the human hippocampus. Because both verbal memory processes and synaptic plasticity are impaired by a hippocampal seizure focus, we suggest that impaired synaptic plasticity may contribute to deficient declarative memory in human temporal lobe epilepsy.

Microisolated mouse osteoclasts express VIP-1 and PACAP receptors

Skeletal tissue contains a network of nerve fibers expressing several neuropeptides, including vasoactive intestinal peptide (VIP) and the related peptide pituitary adenylate cyclase activating peptide (PACAP). These peptides have been demonstrated to regulate osteoclast formation and osteoclast activity. Using atomic force microscopy and by analysing changes of the intracellular calcium concentrations, we have recently demonstrated that multinucleated rat osteoclasts have cell membrane binding sites recognising VIP and PACAP. In the present study, we have further studied the expression of VIP receptor subtypes in mouse bone marrow cultures and isolated osteoclasts. A micromanipulation technique was used to isolate pure populations of osteoclasts formed in PTH-stimulated mouse bone marrow cultures. By reverse transcriptase polymerase chain reaction (RT-PCR), we studied the expression of mRNA for VIP-1, VIP-2, and PACAP receptors. The purity of the microisolated osteoclasts was determined by studying the expression of specific mRNA associated with the phenotypic trait of osteoclasts or osteoblasts/stromal cells. In this study, we show that mouse osteoclasts express VIP-1 and PACAP, but not VIP-2, receptor mRNA.

Loss of dynorphin-mediated inhibition of voltage-dependent Ca2+ currents in hippocampal granule cells isolated from epilepsy patients is associated with mossy fiber sprouting

The endogenous kappa receptor selective opioid peptide dynorphin has been shown to inhibit glutamate receptor-mediated neurotransmission and voltage-dependent Ca2+ channels. It is thought that dynorphin can be released from hippocampal dentate granule cells in an activity-dependent manner. Since actions of dynorphin may be important in limiting excitability in human epilepsy, we have investigated its effects on voltage-dependent Ca2+ channels in dentate granule cells isolated from hippocampi removed during epilepsy surgery. One group of patients showed classical Ammon's horn sclerosis characterized by segmental neuronal cell loss and astrogliosis. Prominent dynorphin-immunoreactive axon terminals were present in the inner molecular layer of the dentate gyrus, indicating pronounced recurrent mossy fiber sprouting. A second group displayed lesions in the temporal lobe that did not involve the hippocampus proper. All except one of these specimens showed a normal pattern of dynorphin immunoreactivity confined to dentate granule cell somata and their mossy fiber terminals in the hilus and CA3 region. In patients without mossy fiber sprouting the application of the kappa receptor selective opioid agonist dynorphin A ([D-Arg6]1-13, 1 microM) caused a reversible and dose-dependent depression of voltage-dependent Ca2+ channels in most granule cells. These effects could be antagonized by the non-selective opioid antagonist naloxone (1 microM). In contrast, significantly less dentate granule cells displayed inhibition of Ca2+ channels by dynorphin A in patients with mossy fiber sprouting (Chi-square test, P < 0.0005). The lack of dynorphin A effects in patients showing mossy fiber sprouting compares well to the loss of kappa receptors on granule cells in Ammon's horn sclerosis but not lesion-associated epilepsy. Our data suggest that a protective mechanism exerted by dynorphin release and activation of kappa receptors may be lost in hippocampi with recurrent mossy fiber sprouting.

Cholera toxin and forskolin stimulate formation of osteoclast-like cells in mouse marrow cultures and cultured mouse calvarial bones

Osteoclasts are hematopoietic in origin and formed by proliferation, differentiation and fusion of osteoclast progenitor cells. However, the signal transducing mechanisms involved in generation of osteoclasts are not clear. We have used two well-known adenylate cyclase stimulators to examine the effect of cyclic AMP (cAMP) on the number of tartrate-resistant acid phosphatase (TRAP)-positive multinucleated cells in cultured mouse calvarial bones and in mouse bone marrow cultures. The effects of forskolin and cholera toxin were compared with those of parathyroid hormone (PTH) and 1,25(OH)2vitaminD3 (1,25(OH)2D3). PTH, as well as forskolin and cholera toxin, increased the number of osteoclast profiles/mm bone in 24-h and 120-h cultures of mouse calvarial bones. In mouse bone marrow cultures, 1,25(OH)2D3 or PTH stimulated formation of TRAP-positive multinucleated cells. Moreover, forskolin or cholera toxin produced dose-dependent stimulation of these cells at a range of concentrations correlating with their effect on cAMP production. The osteoclastic phenotype of the TRAP-positive cells was demonstrated by autoradiography of 125I-labelled calcitonin binding and by the bone-resorbing activity of the cells. The sustained presence (0-9 d) of forskolin or PTH was required to obtain maximal formation of osteoclasts. However, the presence of 1,25(OH)2D3 was required only for the last 3 d of culture for maximal osteoclast formation. We conclude that PTH may stimulate osteoclast generation using the adenylate cyclase cAMP system as a signal transduction mechanism.

[Occupational diseases in an airline company]

617 cases of occupational health disorders in an average population of approximately 4,400 were reported by the Occupational Health Services of the Norwegian section of SAS during the period 1985 to 1996. Musculoskeletal disorders accounted for approximately 75% of all registered disorders. Wherever possible, occupational disorders should be registered and preventive measures initiated by the company. It is therefore of great importance that a registration system should include all occupational disorders. If we compare our figures with the official Norwegian figures from the Labour Inspectorate, we may conclude that only 3-4% of occupational disorders are reported to the Authorities. In particular it seems that many disorders which do not yield economic compensation (musculoskeletal disorders, and mental stress and burnout syndromes) are not reported at all, making it less likely that preventive measures are implemented. The Nordic figures indicate that inadequate reporting occurs more frequently in Norway than in Sweden, Denmark and Finland.

'Superwarfarin' poisoning leading to prolonged coagulopathy

An elderly Chinese was admitted for haemetemesis. Investigations revealed markedly prolonged clotting times that recurred every few days despite administration of fresh frozen plasma and vitamin K. The derangement in coagulation lasted more than 3 months. In view of the absence of liver disease or malabsorption syndromes, long-acting anticoagulant ('superwarfarin') ingestion was suspected. The diagnosis of rodenticide poisoning was hampered by the lack of available assays. Diagnosis of brodifacoum intoxication using HPLC was confirmed only months after prolonged treatment with high dose vitamin K1. Superwarfarin poisoning should be suspected in cases of deranged coagulation refractory to treatment since these over-the-counter rodenticides are easily available.

Crash pulse recorder--validation in full scale crash tests

Estimation of the accident severity is a fundamental requirement in accident reconstruction and analysis. Accident severity can be measured in many different ways, but in frontal collisions change of velocity, energy equivalent speed or equivalent barrier speed are frequently used parameters. These parameters are most often estimated from vehicle deformation. It is known, however, that the quality of these estimates is limited if compared with these obtained in laboratory test conditions. To be able to achieve almost the same measurements and measurement accuracy in real-life accidents as in the laboratory, where the acceleration time history is measured, an on-board measurement technique is required. This presentation gives results of tests of a low cost device for measuring the crash pulse for a car involved in an accident, concerning systematic and random error. The device, called the Crash Pulse Recorder (CPR), has been tested previously in several sled tests. The CPR is based on measurement of the movement of the mass in a spring mass system in a collision. A brief description of its construction is also included. The CPR is an integral part of a large accident data collection system including interior and exterior deformation measurements and evaluation of injury outcome. This report presents the results of several full-scale crash tests, undertaken to evaluate the accuracy and precision of the CPR in cars in different impact modes. The tests comprised both offset and angled collisions. Most of the tests were car to car collisions, but barrier tests were also performed. The random error of the CPR was found to be 2.2 km/hr for the delta V measurements and 0.6 g for mean acceleration.

Accuracy of implant-supported prostheses in the edentulous jaw: analysis of precision of fit between cast gold-alloy frameworks and master casts by means of a three-dimensional photogrammetric technique

Distortions of 15 routine implant-supported prostheses were measured in relation to the master casts after completion by means of a 3-dimensional (3-D) photogrammetric technique. All prostheses were designed as one-piece gold-alloy castings with resin teeth. Five of the prostheses were placed in the edentulous maxilla, and the remaining were placed in the lower jaw. Distortion of the cylinders was mostly observed in the horizontal plane (x- and y-axis) while the vertical aspect seemed to be more stable. The mean 3-D center point distortion was 42 (SD 15) and 74 (SD 38) microns for the upper and lower jaws, respectively. The measurements revealed a range of 3-D center point distortion from 16 to 80 and 15 to 165 microns for the different jaws, respectively. The corresponding 3-D mean angular distortion of the cylinders was 51 (SD 35) microns in lower and 70 (SD 75) microns in the upper jaws. A correlation was found between 3-D center point distortion and the width as well as the curvature of the implant arch, indicating more displacement the wider and the more curved the arch was. The 3-D center point distortion was also significantly higher in the upper jaws which could possibly be explained by the curvature of the implant arch and higher numbers of implants in the upper jaws. Further problems with the fit of upper jaw castings could be related to more alloy in the castings and poor alignment of implants.

Prognostic factors for primary gastrointestinal lymphoma

The gastrointestinal tract is a common primary extranodal site for non-Hodgkin's lymphoma. There is however no uniform consensus on its pathological classification, clinical staging system and management. This paper reports the experience in the management of 425 Chinese patients with primary gastrointestinal lymphoma in Hong Kong from January 1975 to June 1993. There were 230 (54 per cent) males and 195 (46 per cent) females. Their median age was 53 years. The primary sites were: the esophagus in three (1 per cent), stomach in 238 (56 per cent), small intestine in 131 (31 per cent) and large intestine in 53 (12 per cent). According to the Working Formulation, there were 20 (4.7 per cent) small lymphocytic, 10 (2.4 per cent) follicular small cleaved cell, 15 (3.5 per cent) follicular mixed, five (1.2 per cent) follicular large cell, 40 (9.4 per cent) diffuse small cleaved cell, 50 (12 per cent) diffuse mixed, 181 (43 per cent) diffuse large cell, 30 (7.1 per cent) immunoblastic, five (1.2 per cent) lymphoblastic, 10 (2.4 per cent) diffuse small non-cleaved cell and 50 (14 per cent) unclassifiable lymphoma. Immunophenotyping was performed in 199 (47 per cent) patients: 90 per cent B-cell, 7 per cent T-cell and 3 per cent uncertain. According to a Manchester system, 81 (19 per cent) patients had stage I disease, 44 (10 per cent) stage II, 85 (20 per cent) stage III and 215 (51 per cent) stage IV. B symptoms were present in 275 (65 per cent) patients and bulky disease in 104 (25 per cent). Surgery followed by chemotherapy was the mainstay of treatment. Of the 408 patients treated, 63 per cent had a complete remission with relapse rate of 42 per cent. For those with complete remission, 47 per cent were free from disease at 5 years. The overall median survival of all patients was 45 per cent at 5 years. Multivariate analysis revealed that significant independent prognostic factors predicting better survival were young age of < 60 years, low grade histology, stage I and II disease and absence of bulky tumour. For gastric lymphoma, aggressive surgery did not significantly improve their outcome. Chemotherapy appears to play an important role in the management of gastrointestinal lymphoma. Better classification of the primary gastrointestinal lymphoma and more refined stratification of the patients according to the prognostic variables may allow individualization of treatment. Prospective randomized studies are essential to define the relative roles of surgery, chemotherapy and radiotherapy.

Intensive consolidation chemotherapy for newly diagnosed acute myeloid leukemia using a regime containing moderate dose cytosine arabinoside and mitoxantrone

Fifty patients with previously untreated acute myeloid leukemia were treated with an induction regimen consisting of cytosine arabinoside 100 mg/m2 per day by 18 h i.v. infusion for 7 days, daunorubicin 50 mg/m2 per day by i.v. bolus injection for 3 days and etoposide 75 mg/m2 per day by 1 h i.v. infusion for 7 days. Thirty seven of them (74%) went into complete remission (CR) and they all then received two consecutive courses of consolidation chemotherapy consisting of cytosine arabinoside 500 mg/m2 per day by 1 h i.v. infusion every 12 h for 4 days (total eight doses) and mitoxantrone 12 mg/m2 daily by 30 min i.v. infusion for 3 days. They were followed by maintenance chemotherapy with cytosine arabinoside and thioguanine 2 monthly. With a median follow up time of 24 months, 20 of the 37 complete responders had relapsed (54%). The disease-free survival (DFS) of 37 CR patients and the overall survival of all patients at 24 months were 37 and 44%, respectively. Age of patients and number of courses of induction chemotherapy to achieve CR were significant factors predicting DFS. Myelosuppression was the major toxic side effects. Ten patients had prolonged marrow suppression following consolidation chemotherapy. In conclusion, despite the significant myelosuppression observed, overall improvement in treatment outcome was not demonstrable with the use of this intensive consolidation therapy.

Treatment outcome and prognostic factors for primary nasal lymphoma

PURPOSE

To report our experience managing a large series of Chinese patients with primary nasal lymphoma.

PATIENTS AND METHODS

From January 1975 to December 1993, 100 patients (median age, 50 years) with newly diagnosed primary nasal lymphoma were studied. There were four low-grade, 62 intermediate-grade, nine high-grade, and 25 unclassifiable lymphomas. Immunophenotyping was performed in 45 patients: eight B cell, 35 T cell, and two uncertain. All cases of angiocentric lymphoma that were typed were T cell. Fifty-two patients had stage I disease, 15 had stage II, four had stage III, and 29 had stage IV. Only 15 patients had B symptoms (weight loss, night sweats, and/or fever), and 11 had bulky disease. Thirty-nine patients with clinically localized stage I and II disease received local radiotherapy alone (before 1980), and the remaining 28 stage I and II patients received combination chemotherapy followed by local radiotherapy. The 33 patients with advanced stage III and IV disease were given combination chemotherapy, and additional radiotherapy was given to five of them who had bulky local disease.

RESULTS

Significantly higher complete remission rates were observed in patients with early stages of disease and those without B symptoms. Superior disease-free survival after complete remission was observed in patients with stage I/II disease. Univariate factors associated with a better overall survival included age less than 60 years, stage I disease, and absence of B symptoms. Survival was significantly better in the subgroup of patients with stage I disease.

CONCLUSION

Patients with nasal lymphoma, especially those with advanced disease, seemed to have a poor prognosis, and their clinical outcome was not improved significantly by the use of chemotherapy instead of radiotherapy or the use of doxorubicin-containing chemotherapeutic regimens.

Mucosal topography around implants in edentulous upper jaws. Photogrammetric three-dimensional measurements of the effect of replacement of a removable prosthesis with a fixed prosthesis

A photogrammetric technique was tested to measure the topography of the mucosa around implants, placed in edentulous upper jaws. Photographs were taken of casts from 6 patients, who all had used a removable overdenture for one year. Another series of photographs was taken on new casts after the use of a fixed prosthesis for a second year. The 6 pairs of photographs were measured and compared in an analytical stereo plotter for surface contour and implant positions. The results from the measurements indicated a trend of general recession of the mucosa after one year with fixed prosthesis, both on the buccal as well as on the palatal side. The mean volume of recession was 222.4 mm3, corresponding to an average of 0.4 mm3/mm2 of mucosa. More recession was generally observed on the palatal side, but obvious variations between the patients were present. In conclusion, the photogrammetric technique was considered to be well suited for analysing tissue contours in various dental situations.

Poor outcome of intensive chemotherapy for adult acute lymphoblastic leukemia: a possible dose effect

Fifty consecutive adult patients with acute lymphoblastic leukemia (ALL) were treated with an intensive cyclical chemotherapy and the mean received dose of individual cytotoxic drug was retrospectively studied. The median age was 28 years. Twenty-one (43%) had white blood cell (WBC) count over 30 x 10(9)/l. Of the 26 patients with successful cytogenetic studies, ten (28%) had unfavorable clonal chromosomal abnormalities (four Philadelphia chromosome, six others). A high complete remission (CR) rate (86%) was achieved. This was associated with delivery of 100% of the planned dosage of vincristine, prednisone, and daunorubicin at induction. Dose reduction of asparaginase, the fourth drug in the induction protocol, was recorded in 20 (40%) patients. The CR rate of these patients was not adversely affected. Dose reduction was recorded during consolidation (38 of 43 remitters) and maintenance (18 of 20 remitters) as a result of treatment toxicity. The mean received dose of teniposide, Ara-C, asparaginase, mercaptopurine, and methotrexate was 73% (SD 7%), 73% (SD 7%), 62% (SD 41%), 65% (SD 15%) and 73% (SD 17%) of the planned dosage, respectively. The 5-year overall survival and leukemia-free survival (LFS) were 11% (95% CI: 0-27%) and 13% (95% CI: 0-26%), respectively. Even standard-risk patients had 4-year LFS of only 26% (95% CI: 0-57%). Among 36 remitters not withdrawn from consolidation, there were 29 treatment failures after a median follow-up of 42 months; 25 (86%) of these were leukemia relapse, three (10%) were toxic death during consolidation, and one patient (4%) died from therapy-related myelodysplastic syndrome. We postulate inadequate drug delivery during postremission therapy contributed to the high relapse rate in the whole group as well as the standard-risk patients.

Photogrammetric measurements of implant positions. Description of a technique to determine the fit between implants and superstructures

A photogrammetric technique was designed to measure the position of dental implants in 3 dimensions to enable assessment of the fit of superstructures placed on the implants. A relatively simple camera set-up was developed and tested. Calibration of the camera was performed in a high-precision analytical plotter and revealed a film measurement accuracy of 0.005 mm. The achieved measuring accuracy for clear and well defined points on clinical components was found to be around 0.02 mm. To find the center points of the implants, points on the circumference were measured. These points are not well defined, which resulted in an estimation of the center point of the implant with a precision of 0.05 mm. Independent measurements of a prosthesis with 5 implants were also within the precision of 0.05 mm. The angular orientation of the top surface of the implant cylinder (abutment, brass replica of gold alloy cylinder of the framework) was measured with a precision of 0.01 radians, which corresponded to an error with a peripheral gap of about 0.03 mm. This value was about 5-10 times lower than the clinical fit between frameworks and abutments, measured in 3 randomly selected clinical cases.

Photogrammetry for documentation of vehicle deformations--a tool in a system for advanced accident data collection

Vehicle deformations are important sources for information about the performance of safety systems. Photogrammetry has developed vastly under recent years. In this study modern photogrammetrical methods have been used for vehicle deformation analysis. The study describes the equipment for documentation and recording in the field (semi-metric camera), and a system for photogrammetrical measurements of the images in laboratory environment (personal computer and digitizing tablet). The material used is approximately 500 collected and measured cases. The study shows that the reliability is high and that accuracies around 15mm can be achieved even if the equipment and routines used are relatively simple. The effects of further development using video cameras for data capture and digital images for measurements are discussed.

Expression of decorin mRNA in the nervous system of rat

A rat cDNA clone (pCD67) isolated from a cDNA library of regenerating sciatic nerve by differential hybridization screening revealed 75% homology on the nucleic acid level and 81% homology (including conservative amino acid changes) to the deduced amino acid sequence of the core protein of human dermatan/chondroitin sulfate proteoglycan decorin (PGII, PG40, PG-S2). Two transcripts of 1.3 and 1.75 KB very similar in size to the two decorin mRNA species previously identified in connective tissue were detected by Northern blotting in both normal and injured sciatic nerve and in the mature and embryonic rat brain. The steady-state level of the decorin 1.3 KB mRNA was very much higher in peripheral nerve than in the central nervous system or in other non-neural tissues (skeletal muscle, heart, colon, kidney). In situ hybridization experiments indicated that decorin mRNA is expressed by Schwann cells and vascular cells in peripheral nerve. In the spinal cord the ventral horn motor neurons and other neurons in gray matter showed specific hybridization signals. Furthermore, in situ hybridization indicated decorin expression in Purkinje neurons and cells of the molecular layer in cerebellum, and in neurons of the primary olfactory cortex and brainstem (pons). Our data clearly demonstrate decorin mRNA expression in distinct neural cell populations, suggesting yet unknown functions of this proteoglycan in the peripheral and central nervous system.

Coexpression of PMP22 gene with MBP and P0 during de novo myelination and nerve repair

The recently cloned PMP22 gene, the rat variant of the murine growth arrest-specific gene gas3, encodes a new 22 kD integral membrane glycoprotein of peripheral myelin. By means of in situ hybridization and immunohistochemistry, we have (1) analyzed PMP22 expression in myelinated and nonmyelinated peripheral nerves, and (2) compared the spatio-temporal changes in the expression of PMP22 mRNA with the expression of the myelin genes P0 and MBP (myelin basic protein) in developing as well as degenerating and regenerating sciatic nerve of rat. (3) We further investigated the expression of PMP22 mRNA by Northern blot in cultured Schwann cells maintained under different conditions of cell growth and arrest. Expression of PMP22 mRNA is restricted to Schwann cells of myelinated peripheral nerve. Transection of sciatic nerve in adult rat leads to a simultaneous and rapid decline in both PMP22 and P0 mRNA to nondetectable levels in the degenerating distal stump. When a demyelinated and axon-free distal stump, as indicated by the lack of MBP and neurofilament immunoreactivity, was reanastomosed to its proximal counterpart, the coordinated reexpression of PMP22 and MBP succeeded axonal regeneration through the distal segment with a delay of 1-2 weeks. As in regenerating nerve, a striking synchrony of expression of PMP22 and P0 transcripts, as well as MBP immunoreactivity, could be observed during sciatic nerve development. Further, in vitro evidence suggests that, unlike NIH3T3-fibroblasts, expression of PMP22/gas3 is not strictly growth arrest-specific in Schwann cells.(ABSTRACT TRUNCATED AT 250 WORDS)

Effective salvage therapy using all-trans retinoic acid for relapsed and resistant acute promyelocytic leukemia

All-trans retinoic acid (ATRA) has been shown to be active against acute promyelocytic leukemia (APL). Six patients with APL, either in relapse or resistant to initial chemotherapy were reinduced with ATRA 100 g/m2/day for 6 weeks. Complete remission was achieved in all six of them. Side effects were seen in two of them. ATRA appears to provide a relatively safe and reliable means to induce a complete remission in patients with refractory or relapsed APL.

Detection of immunoglobulin gene rearrangement in lymphoid malignancies of B-cell lineage by seminested polymerase chain reaction gene amplification

Seminested polymerase chain reaction (PCR) was used to amplify the DNA fragments of the complementarity-determining region 3 of the immunoglobulin (Ig) gene heavy chain from the malignant cell specimens of patients with leukemias and lymphomas of B-cell lineage. Two different pairs of primers were used sequentially. Twenty of the 27 (74%) acute lymphoblastic leukemia (ALL) patients, 14 of 19 (74%) chronic lymphocytic leukemia (CLL) patients and eight of 20 (40%) non-Hodgkin's lymphoma (NHL) patients, who had rearrangement of the Ig gene heavy chain by Southern analysis, were positive by the seminested PCR. False-negative results appeared to occur more commonly in cases of lymphoma. The PCR analysis was also less likely to be positive if one-stage PCR studies with either pair of primers were both negative. The seminested PCR technique was found to have a high sensitivity of detecting malignant cells at the level of 0.02%. The clinical application of this assay needs to be investigated further.

COPP chemotherapy for elderly patients with intermediate and high grade non-Hodgkin's lymphoma

One hundred and forty-one consecutive patients above and 231 below the age of 60 years with previously untreated intermediate or high grade non-Hodgkin's lymphoma were included in this study. Patients above the age of 60 years were treated with the COPP chemotherapy regimen. The younger patients, at or below the age of 60, received a doxorubicin-containing regimen (119 had CHOP, 65 had BACOP and 47 had m-BACOD). For stage I patients, the clinical results were similar but for stage II, III or IV disease, those receiving COPP had significantly worse CR rate and survival than those who had a doxorubicin-containing regimen. Multivariate analysis on patients receiving the COPP chemotherapy revealed that the independent prognostic variables significantly determining CR rate and survival included clinical stage (p = 0.04) and serum lactate dehydrogenase level (p = 0.001). Myelosuppression was the major toxicity following COPP chemotherapy in this group of patients. There were 10 (7 per cent) treatment-related deaths. Compared to the reported results using doxorubicin-containing regimens to treat elderly patients with aggressive NHL in the literature, the more aggressive treatment does not appear to improve significantly the clinical outcome of this group of patients and seems to produce treatment results very much similar to COPP. However, accurate comparison is difficult because of the variation in the patient characteristics. Further prospective controlled randomized trials will be necessary to determine the optimal therapy for these patients.

Intensive chemotherapy for peripheral T-cell lymphomas

Forty-two patients with previously untreated peripheral T-cell lymphomas (PTCL) were treated with an intensive chemotherapy protocol. Either the BACOP or the m-BACOD regimen was used for induction. Patients achieving complete clinical remission after three courses were given intensive consolidation and maintenance chemotherapy similar to the L10/L17M protocol designed by the Memorial Sloan-Kettering Group for acute lymphoblastic leukemia and lymphoblastic lymphoma. There were 27 (64 per cent) males and 15 (36 per cent) females. The median age was 54 years (mean 53, range 15 to 68). Seven of them (17 per cent) had stage I disease, four (10 per cent) stage II, seven (17 per cent) stage III and 24 (57 per cent) stage IV. Eighteen patients (43 per cent) had B symptoms and four (10 per cent) had bulky disease. According to the Working Formulation, the histology was diffuse mixed in 16 patients (38 per cent), diffuse large cell in 18 (43 per cent), diffuse immunoblastic in four (10 per cent) and unclassifiable in four (10 per cent). According to a modified Japanese Lymphoma Study Group's classification, the histology in 24 patients (57 per cent) was the pleomorphic type, in 13 (31 per cent) immunoblastic-lymphadenopathy-like (IBL-like), and in five (12 per cent) unclassifiable. The overall complete remission rate was 67 per cent. Twenty-five per cent of the complete responders relapsed and the DFS of the CR patients was 62 per cent at three years. The overall survival of all patients at three years was 52 per cent. Patients with stage I, II and III disease had significantly better CR rate (100 per cent versus 42 per cent, p = 0.001) and overall survival (82 per cent versus 35 per cent at three years, p = 0.01) than those with stage IV disease but the relapse rate and DFS of CR patients were similar. This study shows that the prognosis of patients with PTCL can be improved by intensive therapy.

Intensive chemotherapy for adult lymphoblastic lymphomas

A total of 20 adults patients presenting with previously untreated lymphoblastic lymphoma underwent an intensive chemotherapy protocol. Either the BACOP or the m-BACOD regimen was used for induction. If the patients achieved a complete clinical remission (CR) after three courses, they were given intensive consolidation and maintenance chemotherapy based on a protocol that was modified from the L10/L17M regimen of the Memorial Sloan-Kettering group for acute lymphoblastic leukaemia and lymphoblastic lymphoma. Patients exhibiting localised areas of bulky disease were given additional involved-field radiotherapy. In all, 15 (75%) men and 5 (25%) women were entered in this study. Their median age was 28 years (mean, 30 years; range, 12-64 years). Overall, 3 (15%) had stage II disease, 3 (15%) had stage III disease and 14 (70%) had stage IV disease; 7 (35%) patients exhibited B symptoms and 4 (20%) had bulky disease. The overall (CR) rate was 10/20 (20%), and that following BACOP and m-BACOD therapy was 4/8 (50%) and 6/12 (50%), respectively. In all, 7 of the 10 complete responders (70%) relapsed. The disease-free survival of the ten who achieved a CR was 23% at 3 years. The overall survival of all 20 patients at 3 years was only 37%, and there were very few long-term survivors. More effective treatment for adult lymphoblastic lymphoma is required.