PubMed Health⌕ Search

Biomedical subjects

M Härmä

Publications and source records attributed to M Härmä.

At least 19 recordsLinked to original sources
PubMed2006

The triad of shift work, occupational noise, and physical workload and risk of coronary heart disease.

BACKGROUND: Shift work, noise, and physical workload are very common occupational exposures and they tend to cluster in the same groups of workers. OBJECTIVES: To study the short and long term effects of these exposures on risk of coronary heart disease (CHD) and to estimate the joint effects of these factors. METHODS: The study population in this prospective 13 year follow up study of 1804 middle aged industrially employed men was collected at the first screening for the Helsinki Heart Study. The CHD end points (ICD-9 codes 410-414 and ICD-10 codes I20-I25) were obtained from official Finnish registers. The Finnish job-exposure matrix FINJEM provided information on occupational exposures. Relative risks (RR) of CHD for the exposures were estimated using Cox's proportional hazard models adjusting for classical risk factors of CHD. RESULTS: The RR in the five year follow up for continuous noise combined with impulse noise was 1.28; for shift work it was 1.59, and for physical workload 1.18, while in the 13 year follow up the RRs were 1.58, 1.34, and 1.31, respectively. When adjusted for white-collar/blue-collar status the RRs decreased markedly. The RR in the 13 year follow up for those exposed to two risk factors was close to 1.7 and for those exposed to all three, 1.87. CONCLUSION: Shift work and continuous noise entailed an excess risk for CHD in the shortest follow up with only a few retired workers but a decreasing risk during the longer follow up. For physical workload and impulse noise the trend was opposite: the CHD risk was increasing with increasing follow up time despite increasing numbers of retired workers.

Adult↗
PubMed2005

Red blood cell and tissue water content in experimental thermal injury.

UNLABELLED: Oedema formation and changes in local blood flow are known phenomena in burns. The relationship between these two is not clearly described. The aim of this study was firstly to examine both the contents of red blood cells and tissue water in skin and subcutaneous fat after experimental burns of different depths in pigs, and secondly, to confirm our recent findings of the increased dielectric constant of skin and subcutaneous fat reflecting considerable oedema formation, especially in fat after thermal injury. METHODS: Superficial, partial and full thickness contact burns were created to pigs and followed for 24h. Radioactive Cr-51 labelling of red cells was used to estimate the number of red cells in tissue, and the absolute amount of water was determined by lyophilization. RESULTS: A decreased number of labelled red cells in skin and an increase in tissue water in subcutaneous fat were found regardless of burn depth. The highest water amount in fat was found in the partial thickness burns. CONCLUSION: All burn depths resulted in a diminished number of labelled red blood cells in skin and a significant increase in the absolute water amount in subcutaneous fat at 24h post injury. The findings in fat support our recent findings of highly elevated dielectric constants measured by the new in vivo method of dielectric measurements.

Adipose Tissue↗
PubMed2005

Microdialysis for detection of dynamic changes in tissue histamine levels in experimental thermal injury.

Histamine is an important mediator contributing to oedema formation after thermal injury. Tissue histamine concentrations have been previously determined by analyzing tissue biopsies. The microdialysis method enables continuous collection of samples from the extracellular tissue fluid. In this experimental burn study on pigs samples from the extracellular fluid for histamine analysis were collected from superficial, partial thickness and full thickness burn sites during a 24-h period. There was a burn depth-related increase in histamine concentrations during the first 2 h post injury. Deep burns induced a more profound initial increase in tissue histamine concentration than the partial thickness and superficial burns. Histamine concentrations at all burn sites declined until 12 h post injury. There was a second rise in tissue histamine concentrations between 12 and 24 h post injury without a rise in plasma histamine concentrations. Histamine concentrations at all burn sites were higher than at the non-burned control sites. The microdialysis technique is an easily applicable method of collecting on-line samples from burned tissue. This method provides a useful tool in investigating the effects of different treatment modalities on the secretion of substances into interstitial fluid within burned tissue.

Animals↗
PubMed2005

HHV-6-DNAemia related to CMV-DNAemia after liver transplantation.

In addition to cytomegalovirus (CMV), activation of other betaherpesviruses, especially human herpesvirus 6 (HHV-6), has been reported in liver transplant patients. The purpose of this study was to investigate the posttransplant HHV-6-DNAemia in relation to CMV-DNAemia in liver transplant patients. Thirty-one adult liver allograft recipients were regularly monitored for CMV and HHV-6 during the first 3 months after transplantation. For the diagnosis of CMV infections, pp65-antigenemia assay and quantitative DNA-PCR were used. HHV-6 was demonstrated by using quantitative DNA-PCR and HHV-6 antigenemia test. Altogether 253 blood specimens of 31 recipients were analyzed. In addition, CMV and HHV-6 specific antigens were demonstrated by immunohistochemistry in liver biopsy specimens in the case of graft dysfunction. Thirteen patients (40%) developed a clinically significant CMV infection, at a mean of 33 days (range 5 to 62 days) after transplantation and were treated with intravenous ganciclovir. The peak viral loads of these symptomatic CMV infections were high (CMV-DNA 34210 +/- 37557 copies/mL plasma). Six additional asymptomatic patients demonstrated significantly lower CMV-DNAemia levels (1020 +/- 1008 copies/mL, P < .05), and were not treated. Concurrently with CMV, HHV-6 DNAemia and antigenemia were detected in 17 of 19 patients, mean 11 days (range 6 to 24 days) after transplantation. HHV-6 appeared prior to CMV in most cases (12 of 17). However, the peak viral loads were low (HHV-6-DNA <1500 copies/mL blood), even in the five patients who demonstrated HHV-6 antigens on liver biopsy. All CMV infections were successfully treated with ganciclovir and the CMV DNAemia/antigenemia subsided. HHV-6 also responded to the antiviral treatment, but more slowly and less clearly. In conclusion, HHV-6 activations were common and usually associated with CMV infection in liver transplant patients. Further investigation of the clinical significance of HHV-6 DNAemia/antigenemia is necessary.

Adult↗
PubMed2005

The shoelace method in congenital aplasia of the scalp and skull.

Aplasia cutis congenita (ACC) is an uncommon skin disorder characterised by the absence of some or all layers of the skin. It may involve any part of the body, but is most common in the scalp. Some scalp lesions are associated with a defect of the underlying skull or even dura. Small superficial lesions heal spontaneously. Options available for larger defects and those involving the skull include conservative management, skin grafts, composite grafts, local scalp or pericranial flaps, and free microvascular transplants. This case report presents a delayed primary closure of a scalp and skull defect with the shoelace method and a temporary skin graft. The method is simple, gives an excellent cosmetic result, and can be used in moderately sized defects, where a direct suture is not possible.

Diseases in Twins↗
PubMed2004

The progression of burn depth in experimental burns: a histological and methodological study.

UNLABELLED: This study was designed to create a reproducible model for experimental burn wound research in pigs. Previously, the thicker paraspinal skin has been used. We used the more human-like ventral skin to create burns of different depths. Contact burns were created to 11 pigs using a brass plate heated to 100 degrees C in boiling water. Different contact times were used to create burns of different depths. In pigs 1-6, the follow-up time was 72 h and in pigs 7-11 24 h. Burn depth was determined by histology. Histologically, samples were classified into five anatomical layers: epidermis, upper one-third of the dermis, middle third of the dermis, deepest third of the dermis and subcutaneous fat. The location of both thromboses and burn marks were evaluated, respectively. The 1 s contact time lead to a superficial thermal injury, 3 s to a partial thickness and 9 s to a full thickness injury. A progression of burn depth was found until 48 h post-injury. The intra-observer correlation after repeated histological analyses of burn depths by the same histopathologist and the repeatability of burn depth creation yielded kappa coefficients 0.83 and 0.92, respectively. CONCLUSION: a reproducible burn model for further research purposes was obtained.

Animals↗
PubMed2004

The surgical and oncological safety of immediate breast reconstruction.

AIM: The aim of our study was to (1) examine the incidence of surgical complications, (2) determine the incidence of loco-regional recurrences and (3) examine the safety of saving the nipple-areola-complex after immediate breast reconstructions in breast cancer. METHODS: Sixty-six immediate breast reconstructions were performed. Wide local excision (WLE), skin sparing mastectomy and subcutaneous mastectomy (SCM) were performed to 12, 20 and 34 patients, respectively. In all patients with WLE the reconstruction was performed with the latissimus dorsi (LD) miniflap. In other patients reconstructions were done with a free TRAM-flap (n=26) LD-flap (n=27) or with a prosthesis only (n=1). RESULTS: Major flap necrosis developed in four patients. Local recurrence rate was 8.3% in the group where nipple-areola-complex was removed and 7.1% in the group where nipple-areola-complex was saved. Metastases were found in 12.5 and 0%, respectively. CONCLUSION: SCM compared to skin sparing mastectomy may lead to an enhanced risk of immediate surgical complications, but does not threat the oncological safety. Saving the nipple-areola-complex in immediate breast reconstructions is possible in early breast cancer, if the tumour is not in the central part of the breast.

Adult↗
PubMed2002

The effect of an irregular shift system on sleepiness at work in train drivers and railway traffic controllers.

Sleepiness and fatigue are frequent problems in railway transportation with occasional monotony and irregular shift schedules. This study aimed at (1) studying the prevalence of severe sleepiness in shifts and (2) examining which shift and sleep-related factors were associated with the occurrence of severe sleepiness in an irregular shift system. A total of 126 randomly selected male train drivers (Tdrs) and 104 railway traffic controllers (Tcos) were investigated using questionnaires and sleep-wake diaries. A sleep diary was used to collect information on sleepiness at work and sleeping times during the 21 consecutive days of the study. The prevalence of severe sleepiness at work (i.e. Karolinska Sleepiness Scale 7 or higher) was modelled by a logistic regression analysis for repeated measurements (GEE) using different shift schedule related factors and sleep length as explanatory variables. Severe sleepiness was reported in 49% (Tdrs) and 50% (Tcos) of the night shifts and in 20% (Tdrs) and 15% (Tcos) of the morning shifts. The odds ratios showed that the risk for severe sleepiness was 6-14 times higher in the night shift and about twice as high in the morning shift compared with the day shift. Age affected the two occupational samples differently: with Tdrs increased age was associated with an additional 8% reduction of risk for severe sleepiness for each year of age, while the Tcos did not show any age dependency. Shift length increased the risk by 15% for each hour of the shift and main sleep period decreased the risk by 15% for each hour of the main sleep. The risk of severe sleepiness was not consistently related to the time-off period before the shifts. The results indicate that adjustments for shift timing, length and off-duty time, in addition to actions aiming at extending the main sleep period, would probably decrease severe sleepiness in railway transportation.

Adult↗
PubMed2002

Viewpoints on oncoplastic surgery in invasive breast cancer.

Breast conserving therapy is the best method to the breast cancer treatment when concerning the psychological sequelae to the patient. Cosmetic results after conservative surgery are not always acceptable: about 20% of patients need a revision operation and correcting the residual defect of the breast or asymmetry of the breasts afterwards. Oncoplastic surgery means that the methods familiar to plastic surgeon are used to increase the number of patients treated with conservative surgery without compromising the oncologic results. Even wider margins than in normal breast conservation can be gained, if local glandular flaps, musculocutaneous latissimus dorsi flaps or microvascular free TRAM flaps are used to immediately preserve the shape and symmetry of the breasts. With plastic surgery it is possible to reshape the breast, replace the nipple and gain breast symmetry. As we know every tenth woman will have a breast cancer during her lifetime, and 80% of breast cancer women will survive. It is important to operate breast cancer immediately to save costs and help a patient feel that her breasts are still a part of her own body.

Attitude of Health Personnel↗
PubMed2001

Flexible working hours and well-being in Finland.

Flexibility of working hours became more prevalent in the 1990s in Finland. According to a representative survey on Finnish wage and salary earners (n = 1790) at the beginning of 2000, a great majority of male (76%) and female (65%) employees regularly worked overtime and/or had irregular working hours every month. These employees were flexible in meeting the needs of their companies/employers. Individual flexibility of working hours was far less common, only one third of male and female employees were able to regulate their working hours. A better balance between company-controlled and individual flexibility would, however, improve the well-being of employees. Employees working overtime without being allowed to regulate their working hours felt more symptoms of distress and had more conflicts in combining workplace and family roles than those who could individually determine their working hours flexibly. An investment in individually determined flexibility, for example by means of participatory planning, would improve the well-being of employees, and thus also improve the productivity of the organization.

Adult↗
PubMed2001

Shiftwork, age and well-being: recent developments and future perspectives.

The working population is aging fast in most European countries and in the USA. The health and well-being of an elderly shift worker depends on the interaction of several individual, medical, psychosocial and job-related factors. These factors are related to the biological ageing process, but also to changes in one's individual life situation and the needs of the ageing shift worker. The evidence of good age-specific solutions in working hours is limited, but the few published intervention studies support the use of individual flexibility, rapid forward rotating shift systems, and earlier shift start-end times in three-shift work. In addition to the development of shift schedules, the counter-measures to improve the health and well-being of ageing shift workers should be focused on the improvement of occupational health care and the promotion of appropriate coping mechanisms for the aging.

Adaptation, Psychological↗
PubMed2001

Evaluation of a fast forward rotating shift schedule in the steel industry with a special focus on ageing and sleep.

The aim of this study was to explore the effect of a change in the speed and direction of shift rotation on the sleep and wakefulness of younger and older workers. A continuous three-shift schedule was changed from a slow backward rotating (EEE-MMMNNN-----) to a fast forward rotating system (MMEENN----). Sixteen subjects (mean age 42 years) were studied before and one year after the change in schedule. Two age groups were compared: ten younger men (mean age 35 years) and six older men (mean age 53 years). The effects of the new work schedule were evaluated by a questionnaire (modified SSI), and on-site registrations with an actigraph and sleep log for one shift cycle (10-15 days) before and after the new schedule. After the change in schedule, subjective sleep problems decreased and alertness increased during the morning shifts. The change in schedule influenced sleep differently in the two age-groups. Both the subjective and objective quality of sleep improved among the older workers. The results indicate that a fast forward rotating shift schedule is more suitable for older workers than a slower backward rotating system.

Adaptation, Psychological↗
PubMed1998

A dose-response study of total sleep time and the ability to maintain wakefulness.

The apparent connection between sleep debt, performance decrements and workplace accidents has generated a need for feasible vigilance tests that focus on the quantification of daytime sleepiness in occupational settings. The objective of this study was to evaluate the sensitivity of the Maintenance of Wakefulness Test (MWT) to acute sleep deprivation of various doses. Eight healthy female volunteers, mean age 28.9 years (range 23-36), participated in this laboratory study. After an adaptation night, the subjects were assigned to four counterbalanced, randomly ordered night sleep conditions. These four conditions allowed for a time in bed (TIB) of 0, 2, 4 or 8 h, producing a total sleep time of 0, 113, 218 and 427 min, respectively. The ability to sustain wakefulness was measured after the TIB period at 11.00 and 17.00 hours by the MWT. Analysis of variance with repeated measures was used to study the dependence of MWT sleep latencies on the immediately prior TIB period. Both the latency of stage 1 sleep onset and the appearance of slow eye movements reduced significantly with increased sleep loss. The quantitative relationship between the previous total sleep time and the subsequent MWT sleep latencies followed an exponentially decaying function showing a high sensitivity to acute, severe night sleep loss but low sensitivity to less severe sleep restrictions. It is concluded that the MWT seems to be a sensitive method for the estimation of acute sleep deprivation. The test results appear, however, non-linearly related to the earlier sleep debt.

Adult↗
PubMed1998

Promoting alertness with a short nap during a night shift.

The use of a short (< 1 h) nap in improving alertness during the early morning hours in the first night shift was examined under laboratory conditions. The study contained four experimental, non-consecutive night shifts with a nap of either 50 or 30 min at 01.00 or 04.00 hours. An experimental night shift without a nap served as a control condition. Each experimental shift was followed by daytime sleep. Fourteen experienced male shift workers went through all of the experimental conditions. The results showed that the naps improved the ability to respond to visual signals during the second half of the night shift. Physiological sleepiness was alleviated by the early naps, as measured 50 min after awakening, but not at the end of the shift. Subjective sleepiness was somewhat decreased by the naps. The naps produced sleep inertia which lasted for about 10-15 min. Daytime sleep was somewhat impaired by the 50 min naps. The study shows that a nap shorter than 1 h is able to improve alertness to a certain extent during the first night shift.

Adult↗