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Siltari A, Korhonen O, Raittinen P, Bläuer M, Syvälä H, Tammela TL, Murtola TJ. Abstract 3904: Simvastatin intensifies anti-androgen efficacy against treatment-resistant prostate cancer cells. Cancer Res 2023. [DOI: 10.1158/1538-7445.am2023-3904] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/07/2023]
Abstract
Abstract
Androgen receptor (AR) signaling inhibitors (ARSIs) bicalutamide (Bic) and enzalutamide (Enza) are used in the treatment of castration resistant prostate cancer (CRPC). Prostate cancer (PCa) cells eventually develop treatment resistance against these drugs causing clinical challenges. The mechanisms behind treatment resistance are complex and only partially known. Androgen signaling is linked to lipid and cholesterol metabolism, and they likely play a role in the development of treatment resistance. Cholesterol producing mevalonate pathway can be inhibited by statins, but it is unknown whether statin treatment could enhance effects of ARSIs. We studied combined effects of simvastatin (Sim) with or without Bic or Enza in VCaP originated PCa cell lines resistant to these ARSIs. Unique treatment resistant cell lines were created with long-term cultures of VCaP cells. The cells were kept under anti-androgen influence until the cells were growing normally despite the ARSIs. We analyzed changes in cell growth, RNA expression, and relevant AR signaling and cholesterol metabolism protein expression. Prostate-specific antigen (PSA) secretion was measured as a marker of AR signaling activity. In Bic or Enza resistant cell lines, combination of 2.5 or 5 μM simvastatin + 10 μM Bic/Enza decreased cell growth more than Sim alone, i.e., ARSIs demonstrated efficacy in combination therapy against ARSI resistant cells. In Bic and Enza resistant cells, combination treatment increased the expression of 60 and 26 and decreased the expression of 33 and 48 genes, respectively, compared with simvastatin alone. Altogether, 16 genes expression changed similarly in both cell lines in response to combination therapy. In both cell lines, over 70% of all gene changes were seen on AR-regulated genes. In Bic resistant cells, Sim decreased PSA levels with or without Bic. On the contrary, in Enza resistant cells PSA levels were increased with combination of Sim and Enza. We showed that combined treatment with ARSI and Sim inhibited cell growth more than Sim alone in ARSI resistant cell lines. This suggests that inhibition of the mevalonate pathway could enhance androgen signaling inhibition and potentially circumvent ARSI resistance mechanisms. This phenomenon is supported by epidemiological studies as patients treated with anti-androgens responded better during simultaneous statin treatment. Gene expression differed in combination treatment compared to Sim alone. Future studies are needed on whether interventions on lipid and cholesterol metabolism could enhance treatment of CRPC. Knowledge about the precise mechanisms behind the treatment responses and resistance might lead to new therapeutic applications.
Citation Format: Aino Siltari, Olga Korhonen, Paavo Raittinen, Merja Bläuer, Heimo Syvälä, Teuvo L. Tammela, Teemu J. Murtola. Simvastatin intensifies anti-androgen efficacy against treatment-resistant prostate cancer cells. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 3904.
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Herberts C, Annala M, Sipola J, Ng SW, Chen XE, Nurminen A, Korhonen O, Munzur AD, Beja K, Schönlau E, Bernales CQ, Ritch E, Bacon JV, Lack NA, Nykter M, Aggarwal R, Small EJ, Gleave ME, Quigley DA, Feng FY, Chi KN, Wyatt AW. Abstract 3625: Clonal architecture and evolution of treatment-resistant prostate cancer via deep whole-genome ctDNA sequencing. Cancer Res 2022. [DOI: 10.1158/1538-7445.am2022-3625] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
Background: Circulating tumor DNA (ctDNA) in blood plasma is an emerging tool for clinical cancer genotyping and longitudinal disease monitoring. However, integration of ctDNA tests into clinical management is critically impeded by the poor understanding of the distinct somatic populations comprising bulk ctDNA—including their relationship to synchronous metastatic tissue, and their temporal dynamics during standard-of-care treatment. Prior approaches relying on targeted and/or low-resolution techniques (e.g. targeted exon sequencing, low-pass (shallow) whole-genome sequencing; WGS) do not permit comprehensive dissection of clonal architecture and unbiased analysis of putative resistance mechanisms.
Methods: We performed deep WGS on serial plasma ctDNA (median depth: 185×) and synchronous metastatic tissue biopsies with high tumor purity from 35 patients with metastatic castration-resistant prostate cancer. We developed a subclonal reconstruction algorithm optimized for our data enabling resolution of per-patient evolutionary histories and ctDNA clonal composition. ctDNA nucleosome footprinting was used to infer mRNA abundance in synchronously biopsied metastases and androgen receptor (AR) transcription factor activity at 3224 AR binding sites (ARBS).
Results: We comprehensively assess all classes of genomic alterations and demonstrate that ctDNA harbors greater populational heterogeneity than metastatic tissue (p<0.001). The evolutionary histories of ctDNA populations indicate frequent whole-genome doubling and attenuation of C>T aging-associated mutation signature during subclonal differentiation. Although driver alterations were largely concordant between tissue and ctDNA, each individual metastasis contributed only a minor share of total ctDNA (average ctDNA contribution: 17%). By comparing serial ctDNA before and after clinical progression on potent AR pathway inhibitors, we reveal population restructuring converging solely on AR copy augmentation as the dominant genomic driver of acquired treatment-resistance. Nucleosome depletion at transcription start-sites is highly correlated with same-patient metastatic tissue mRNA abundance, indicating that ctDNA fragmentomics can recapitulate transcriptomic patterns in metastatic lesions. Most ctDNA samples exhibited strong ARBS nucleosome depletion which correlated with AR gene copy number (R=0.36, p=0.003). Finally, serial ctDNA nucleosome profiling at ARBS revealed adaptive transcriptomic resistance to AR pathway inhibitors, including lineage switch to a neuroendocrine-like (AR-low) state.
Conclusions: We show that the populations comprising ctDNA are typically complex and more heterogeneous than those found in bulk WGS of a synchronous metastasis. Our work advocates for liquid biopsy as a comprehensive multi-omic discovery tool for cancers with high ctDNA fractions.
Citation Format: Cameron Herberts, Matti Annala, Joonatan Sipola, Sarah W. Ng, Xinyi E. Chen, Anssi Nurminen, Olga Korhonen, Aslı D. Munzur, Kevin Beja, Elena Schönlau, Cecily Q. Bernales, Elie Ritch, Jack V. Bacon, Nathan A. Lack, Matti Nykter, Rahul Aggarwal, Eric J. Small, Martin E. Gleave, David A. Quigley, Felix Y. Feng, Kim N. Chi, Alexander W. Wyatt. Clonal architecture and evolution of treatment-resistant prostate cancer via deep whole-genome ctDNA sequencing [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 3625.
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Affiliation(s)
- Cameron Herberts
- 1University of British Columbia, Vancouver, British Columbia, Canada
| | - Matti Annala
- 2Tampere University and Tays Cancer Center, Tampere, Finland
| | - Joonatan Sipola
- 2Tampere University and Tays Cancer Center, Tampere, Finland
| | - Sarah W. Ng
- 1University of British Columbia, Vancouver, British Columbia, Canada
| | - Xinyi E. Chen
- 1University of British Columbia, Vancouver, British Columbia, Canada
| | - Anssi Nurminen
- 2Tampere University and Tays Cancer Center, Tampere, Finland
| | - Olga Korhonen
- 2Tampere University and Tays Cancer Center, Tampere, Finland
| | - Aslı D. Munzur
- 1University of British Columbia, Vancouver, British Columbia, Canada
| | - Kevin Beja
- 1University of British Columbia, Vancouver, British Columbia, Canada
| | - Elena Schönlau
- 1University of British Columbia, Vancouver, British Columbia, Canada
| | | | - Elie Ritch
- 1University of British Columbia, Vancouver, British Columbia, Canada
| | - Jack V. Bacon
- 1University of British Columbia, Vancouver, British Columbia, Canada
| | - Nathan A. Lack
- 1University of British Columbia, Vancouver, British Columbia, Canada
| | - Matti Nykter
- 2Tampere University and Tays Cancer Center, Tampere, Finland
| | - Rahul Aggarwal
- 3University of California San Francisco, San Francisco, CA
| | - Eric J. Small
- 3University of California San Francisco, San Francisco, CA
| | - Martin E. Gleave
- 1University of British Columbia, Vancouver, British Columbia, Canada
| | | | - Felix Y. Feng
- 3University of California San Francisco, San Francisco, CA
| | - Kim N. Chi
- 4BC Cancer, Vancouver, British Columbia, Canada
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Karttunen AP, Poms J, Sacher S, Sparén A, Ruiz Samblás C, Fransson M, Martin De Juan L, Remmelgas J, Wikström H, Hsiao WK, Folestad S, Korhonen O, Abrahmsén-Alami S, Tajarobi P. Robustness of a continuous direct compression line against disturbances in feeding. Int J Pharm 2020; 574:118882. [DOI: 10.1016/j.ijpharm.2019.118882] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2019] [Revised: 11/12/2019] [Accepted: 11/13/2019] [Indexed: 11/29/2022]
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Korhonen O, Forsman N, Osterberg M, Budtova T. Eco-friendly surface hydrophobization of all-cellulose composites using layer-by-layer deposition. EXPRESS POLYM LETT 2020. [DOI: 10.3144/expresspolymlett.2020.74] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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Martinetz M, Karttunen AP, Sacher S, Wahl P, Ketolainen J, Khinast J, Korhonen O. RTD-based material tracking in a fully-continuous dry granulation tableting line. Int J Pharm 2018; 547:469-479. [DOI: 10.1016/j.ijpharm.2018.06.011] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2018] [Revised: 05/30/2018] [Accepted: 06/04/2018] [Indexed: 11/28/2022]
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Pajula K, Lahtela-Kakkonen M, Korhonen O. In silico screening of potential crystal growth inhibitors for the stabilization of amorphous structures. Eur J Pharm Sci 2008. [DOI: 10.1016/j.ejps.2008.02.115] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Suihko E, Korhonen O, Järvinen T, Ketolainen J, Jarho P, Laine E, Paronen P. Complexation with tolbutamide modifies the physicochemical and tableting properties of hydroxypropyl-beta-cyclodextrin. Int J Pharm 2001; 215:137-45. [PMID: 11250099 DOI: 10.1016/s0378-5173(00)00682-7] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
The physicochemical and tableting properties of hydroxypropyl-beta-cyclodextrin (HP-beta-CD) and its tolbutamide (TBM) complex were studied. The kinetics of TBM/HP-beta-CD inclusion complex formation in solution were determined by the phase solubility method. Solid complexes were prepared by freeze-drying and spray-drying. Water sorption-desorption behaviour of the materials were studied and compacts were made using a compaction simulator. TBM and HP-beta-CD formed 1:1 inclusion complexes in aqueous solution with an apparent stability constant of 63 M(-1). HP-beta-CDs and TBM/HP-beta-CD complexes were amorphous whereas the freeze-dried and spray-dried TBMs were polymorphic forms II and I, respectively. Sorption-desorption studies showed that HP-beta-CDs were deliquescent at high relative humidities. TBM/HP-beta-CD complexes had slightly lower water contents at low relative humidities than the physical mixtures. However, at high humidities their water sorption and desorption behaviours were similar to those of corresponding physical mixtures, indicating a glass transition of the complexed materials. TBM/HP-beta-CD complexes demonstrated a worse compactability than similarly prepared HP-beta-CDs or physical mixtures. Also particle properties that resulted from these preparation methods affected the compactability of the materials. In conclusion, the physicochemical and tableting properties of HP-beta-CD were modified by complexation it with TBM.
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Affiliation(s)
- E Suihko
- Department of Pharmaceutics, University of Kuopio, PO Box 1627, FIN-70211, Kuopio, Finland.
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Korhonen O, Raatikainen P, Harjunen P, Nakari J, Suihko E, Peltonen S, Vidgren M, Paronen P. Starch acetates--multifunctional direct compression excipients. Pharm Res 2000; 17:1138-43. [PMID: 11087048 DOI: 10.1023/a:1026470032434] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- O Korhonen
- Department of Pharmaceutics, University of Kuopio, Finland
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Suihko E, Poso A, Korhonen O, Gynther J, Ketolainen J, Paronen P. Deformation behaviors of tolbutamide, hydroxypropyl-beta-cyclodextrin, and their dispersions. Pharm Res 2000; 17:942-8. [PMID: 11028939 DOI: 10.1023/a:1007523103979] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
PURPOSE The deformation behaviors of compressed freeze-dried and spray-dried tolbutamide/hydroxypropyl-beta-cyclodextrin molecular dispersions were evaluated and compared with similarly prepared tolbutamides (TBM), hydroxypropyl-beta-cyclodextrins (HP-beta-CD) and as their physical dispersions. METHODS TBM, HP-beta-CD, and their 1:1 molecular dispersions were prepared by freeze-drying and spray-drying, and physical dispersions of TBM and HP-beta-CD were blended. Deformation properties of the prepared materials were evaluated by using a compaction simulator and constants derived from Heckel plots. Molecular dynamics (MD) simulations were performed in order to gain a molecular-level view on the deformation behavior of TBM-HP-beta-CD inclusion complex. RESULTS The freeze-dried TBM polymorphic form II was less prone to overall particle deformation than the spray-dried stable form I. Formation of molecular dispersions decreased the plastic and elastic behaviors of these materials. Also, the MD simulations showed a reduced molecular flexibility of the TBM-HP-beta-CD inclusion complex, as compared to HP-beta-CD. CONCLUSIONS The formation of TBM and HP-beta-CD molecular dispersion resulted in more rigid molecular arrangements, which were less prone to deformation than either HP-beta-CDs or physical dispersions. The results showed how differing molecular, solid, particle, and powder state properties affect the deformation properties of the materials studied.
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Affiliation(s)
- E Suihko
- Department of Pharmaceutics, University of Kuopio, Finland.
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Louhevaara V, Smolander J, Aminoff T, Korhonen O, Shen N. Cardiorespiratory responses to fatiguing dynamic and isometric hand-grip exercise. Eur J Appl Physiol 2000; 82:340-4. [PMID: 10958378 DOI: 10.1007/s004210000200] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
In occupational work, continuous repetitive and isometric actions performed with the upper extremity primarily cause local muscle strain and musculoskeletal disorders. They may also have some adverse effects on the cardiorespiratory system, particularly, through the elevation of blood pressure. The aim of the present study was to compare peak cardiorespiratory responses to fatiguing dynamic and isometric hand-grip exercise. The subjects were 21 untrained healthy men aged 24-45 years. The dynamic hand-grip exercise (DHGE) was performed using the left hand-grip muscles at the 57 (SD 4)% level of each individual's maximal voluntary contraction (MVC) with a frequency of 51 (SD 4) grips x min(-1). The isometric hand-grip exercise (IHGE) was done using the right hand at 46 (SD 3)% of the MVC. The endurance time, ventilatory gas exchange, heart rate (HR) and blood pressure were measured during both kinds of exercise. The mean endurance times for DHGE and IHGE were different, 170 (SD 62) and 99 (SD 27) s, respectively (P < 0.001). During DHGE the mean peak values of the breathing frequency [20 (SD 6) breaths x min(-1)] and tidal volume [0.89 (SD 0.34) l] differed significantly (P < 0.01) from peak values obtained during IHGE [15 (SD 5) breaths x min(-1) and 1.14 (SD 0.32) l, respectively]. The corresponding peak oxygen consumptions, pulmonary ventilations, HR and systolic blood pressures did not differ, and were 0.51 (SD 0.06) and 0.46 (SD 0.11) l x min(-1), 17.1 (SD 3.0) and 16.7 (SD 4.7) l x min(-1), 103 (SD 18) and 102 (SD 17) beats x min(-1), and 156 (SD 17) and 161 (SD 17) mmHg, respectively. The endurance times of both DHGE and IHGE were short (< 240 s). The results indicate that the peak responses for the ventilatory gas exchange, HR and blood pressure were similar during fatiguing DHGE and IHGE, whereas the breathing patterns differed significantly between the two types of exercise. The present findings emphasize the importance of following ergonomic design principles in occupational settings which aim to reduce the output of force, particularly in tasks requiring isometric and/or one-sided repetitive muscle actions.
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Affiliation(s)
- V Louhevaara
- Finnish Institute of Occupational Health, Helsinki.
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Sörensen L, Smolander J, Louhevaara V, Korhonen O, Oja P. Physical activity, fitness and body composition of Finnish police officers: a 15-year follow-up study. Occup Med (Lond) 2000; 50:3-10. [PMID: 10795384 DOI: 10.1093/occmed/50.1.3] [Citation(s) in RCA: 83] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
This study evaluated changes in the physical activity, fitness and body composition of 103 police officers during a 15-year follow-up. The absolute aerobic capacity was similar in 1981 and 1996, muscular performance had declined, and body weight had increased approximately 0.5 kg/year. More than half the subjects (53%) had increased their leisure-time physical activity in 1996. The correlation was significant between physical activity in 1981 and physical fitness in 1996, but weak between physical activity in 1996 and fitness in 1996. It was also significant between waist circumference and waist/hip ratio in 1996 and physical activity during the previous 5 and 15 years. No significant correlations were found between physical activity and work ability or perceived physical or mental job stress. The physical fitness of middle-aged police officers seems to be predicted strongly by physical activity in early adulthood. Therefore health and fitness promotion measures should start at that time. This, together with regular systematic training, should help to sustain work ability of middle-aged police officers.
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Affiliation(s)
- L Sörensen
- Medical Rehabilitation and Physical Exercise Centre Peurunka, Laukaa, Finland.
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Aminoff T, Smolander J, Korhonen O, Louhevaara V. Physiological strain during kitchen work in relation to maximal and task-specific peak values. Ergonomics 1999; 42:584-592. [PMID: 10204422 DOI: 10.1080/001401399185496] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Six female and three male subjects from a hospital kitchen volunteered for the study. The subjects were working on a conveyor belt collecting and sorting dirty plates, glasses and cutlery for cleaning. In the study, a medical examination, a maximal clinical exercise test with a 12-lead electrocardiogram (ECG) and a maximal arm cranking test were performed in the laboratory. Further, each subject was studied for 30 min during a normal work shift in the kitchen. Oxygen uptake (VO2) and heart rate (HR) were continuously registered. During the work period, a rating of perceived exertion (RPE) was asked at the 5th, 15th and 30th minute. Physiological responses were measured by a portable system (K4) both in the laboratory and in the field. VO2 and HR measured in the field were proportioned to corresponding maximal values during cycling and to peak values during arm-cranking. The mean VO2 for the male and the female subjects during kitchen work was 0.65 +/- 0.16 l min-1. This corresponded to 24% of VO2max and to 41% of VO2peak during arm-cranking. The difference was significant (p < 0.001). Owing to a magnetic field at the conveyor belt, reliable HR values were obtained only from the female subjects. The mean HR during work among the female subjects was 101 beats min-1. It corresponded to 55% of HRmax and 67% of HRpeak during arm-cranking (p < 0.05). The present study shows that the relative work intensity is markedly higher when it is expressed relative to the corresponding muscle group's VO2peak instead of the VO2max. Similar difference was also seen in the HR response. More task-specific testing of physical capacity may provide improved evaluation of physical strain in a job.
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Affiliation(s)
- T Aminoff
- Department of Physiology, Finnish Institute of Occupational Health, Vantaa, Finland
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Smolander J, Aminoff T, Korhonen I, Tervo M, Shen N, Korhonen O, Louhevaara V. Heart rate and blood pressure responses to isometric exercise in young and older men. Eur J Appl Physiol Occup Physiol 1998; 77:439-44. [PMID: 9562295 DOI: 10.1007/s004210050357] [Citation(s) in RCA: 59] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The aim of this study was to examine the isometric endurance response and the heart rate and blood pressure responses to isometric exercise in two muscle groups in ten young (age 23-29 years) and seven older (age 54-59 years) physically active men with similar estimated forearm and thigh muscle masses. Isometric contractions were held until fatigue using the finger flexor muscles (handgrip) and with the quadriceps muscle (one-legged knee extension) at 20%, 40%, and 60% of the maximal voluntary contraction (MVC). Heart rate and arterial pressure were related to the the individual's contraction times. The isometric endurance response was longer with handgrip than with one-legged knee extension, but no significant difference was observed between the age groups. The isometric endurance response averaged 542 (SEM 57), 153 (SEM 14), and 59 (SEM 5) s for the handgrip, and 276 (SEM 35), 94 (SEM 10) and 48 (SEM 5) s for the knee extension at the three MVC levels, respectively. Heart rate and blood pressure became higher during one-legged knee extension than during handgrip, and with increasing level of contraction. The older subjects had a lower heart rate and a higher blood pressure response than their younger counterparts, and the differences were more apparent at a higher force level. The results would indicate that increasing age is associated with an altered heart rate and blood pressure response to isometric exercise although it does not affect isometric endurance.
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Affiliation(s)
- J Smolander
- Department of Physiology, Finnish Institute of Occupational Health, Vantaa
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Aminoff T, Smolander J, Korhonen O, Louhevaara V. Prediction of acceptable physical work loads based on responses to prolonged arm and leg exercise. Ergonomics 1998; 41:109-120. [PMID: 9468809 DOI: 10.1080/001401398187350] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Nine healthy men (aged 54-59 years) performed arm crank and leg cycle exercises for 30 min at relative work loads of 50 and 75% of peak oxygen uptake (VO2) for the corresponding muscle group, and for 60 min at a relative work load of 30% of peak VO2 for the corresponding muscle group. In the tests, heart rate (HR), blood pressure, gas exchange variables, rating of perceived exertion (RPE) and blood lactate were measured. At the 75% target exercise level, four subjects interrupted the arm-cranking test, and one subject interrupted the leg-cycle test. Owing to differences in peak values during arm-cranking and leg-cycling, the work load and the VO2 were higher during leg-cycling than during arm-cranking. There was no difference in HR between the work modes, but the HR increased to a greater extent during arm-cranking compared to leg-cycling at the 30% (NS) and 50% (P < 0.05) exercise levels. Similarly, the RPE increased more during arm-cranking compared to leg-cycling at each exercise level. The blood lactate concentration was higher after arm-cranking than after leg-cycling; at the 50% exercise level the difference was statistically significant. The results indicate a higher physiological strain with time during arm exercise than during leg exercise at the same muscle group-specific relative work load. The acceptable physical work load, expressed as the percentage peak VO2 for the corresponding muscle group, should thus be lower during arm exercise than during leg exercise. The RPE and the relative HR, expressed as percentage of peak HR for the corresponding muscle group, however, seem to be comparable indicators for the physiological strain during arm and leg exercise.
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Affiliation(s)
- T Aminoff
- Department of Physiology, Finnish Institute of Occupational Health, Vantaa, Finland
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Aminoff T, Smolander J, Korhonen O, Louhevaara V. Cardiorespiratory and subjective responses to prolonged arm and leg exercise in healthy young and older men. Eur J Appl Physiol Occup Physiol 1997; 75:363-8. [PMID: 9134369 DOI: 10.1007/s004210050173] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Ten young (aged 23-30 years) and nine older (aged 54-59 years) healthy men with a similar size of limb muscle mass performed arm crank and leg cycle exercise for 30 min at relative exercise intensities of 50% and 75% of maximal oxygen uptake for the corresponding muscle group. In the tests, heart rate, blood pressure, gas exchange variables, rating of perceived exertion and blood lactate concentration were measured. The limb muscle mass was determined by anthropometric measurements. At the 75% target exercise level, four of the older men and two of the young men could not complete the arm-cranking test, and one of the older men and two of the young men could not complete the leg-cycle test. During arm-cranking the absolute exercise intensity was similar for the young and older men because of similar maximal values during arm-cranking. But during leg-cycling the absolute exercise intensity was higher for the young men than for the older men due to the difference in corresponding maximal values. During arm-cranking there were no significant differences in the physiological responses between the age groups except that a higher ventilatory response was noted among the older compared to the young men. During leg-cycling the heart rate values were higher among the young compared to the older men. But, when the heart rate values were expressed as a percentage of maximal heart rate in the corresponding maximal tests, no significant differences between the age groups were found. The results indicated that 30-min of arm or leg exercise at the same relative submaximal exercise intensity produces a similar degree of physiological strain in healthy older compared to young men. During armcranking, the young and the older men exercised at the same external intensity, indicating a similar ability to perform prolonged excercise using smaller muscle groups expressed both in absolute and relative terms.
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Affiliation(s)
- T Aminoff
- Finnish Institute of Occupational Health, Department of Physiology, Vantaa, Finland
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Aminoff T, Smolander J, Korhonen O, Louhevaara V. Physical work capacity in dynamic exercise with differing muscle masses in healthy young and older men. Eur J Appl Physiol Occup Physiol 1996; 73:180-5. [PMID: 8861689 DOI: 10.1007/bf00262829] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Ten young (aged 23-30 years) and nine older (aged 54-59 years) healthy men with similar estimated limb muscle volumes performed, in random order, three different types of ergometer exercise tests (one-arm cranking, two-arm cranking, and two-leg cycling) up to the maximal level. Values for work load (WL), peak oxygen consumption (V0(2)), peak heart rate (HR), peak ventilation (V(E)), respiratory gas exchange ratio (R), recovery blood lactate concentration [La-], and rating of perceived exertion (RPE) were compared between the age-groups in the given exercise modes. No significant age-related differences in WL, peak V0(2), peak HR, R, [La-], or RPE were found in one-arm or two-arm cranking. During one-arm cranking the mean peak V0(2) was 1.65 (SD 0.26)1*min(-1) among the young men and 1.63 (SD 0.10)l*min(-1) among the older men. Corresponding mean peak V0(2) during two-arm cranking was 2.19 (SD 0.32)1*min(-1) and 2.09 (SD 0.18)1*min(-1), respectively. During one-arm cranking peak V(E) was higher (P <0.05) among the older men compared to the young men. During two-leg cycling the young men showed higher values in WL (P <0.001), peak V0(2) (P <0.001), and peak HR (P <0.001). The mean peak V0(2) was 3.54 (SD 0.24)1*min(-1) among the young men and 3.02 (SD 0.20)1 . min(-1) among the older men. Corresponding mean peak HR was 182 (SD 5) beats*min(-1) and 170 (SD 8) beats*min(-1), respectively. During two-leg cycling, peak V(E), R, [La-], and RPE did not differ between the two age-groups. In summary, the older men with similar sizes of estimated arm and leg muscle volumes as the young men had a reduced physical work capacity in two-leg cycling. In one-arm or two-arm cranking, no significant difference in work capacity was found between the age-groups. These results indicate, that in healthy men, age, at least up to the 6th decade of life, is not necessarily associated with a decline in physical work capacity in exercises using relatively small muscle groups, in which the limiting factors are more peripheral than central.
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Affiliation(s)
- T Aminoff
- Finnish Institute of Occupational Health, Department of Physiology, Laajaniityntie, Vantaa, Finland
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Smolander J, Ilmarinen J, Korhonen O, Louhevaara V, Nygard CH. 998 A 10-YEAR FOLLOW-UP OF MAXIMAL OXYGEN UPTAKE IN AGING WORKERS WITH DIFFERING JOB DEMANDS. Med Sci Sports Exerc 1994. [DOI: 10.1249/00005768-199405001-01000] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Lusa S, Louhevaara V, Smolander J, Kivimäki M, Korhonen O. Physiological responses of firefighting students during simulated smoke-diving in the heat. Am Ind Hyg Assoc J 1993; 54:228-31. [PMID: 8498358 DOI: 10.1080/15298669391354603] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
While wearing a self-contained breathing apparatus and fire-protective clothing, 35 healthy firefighting students aged 19-27 years performed smoke-diving (entry into a smoke-filled room) during a simulated shipboard fire. The mean (+/- SD) ambient temperature inside the simulator was 119 +/- 12 degrees C, and the task lasted 17 +/- 4 min. All subjects were fit according to their maximal oxygen consumption, which was 52.4 +/- 5.2 mL/min/kg (4.08 +/- 0.45 l/min). During the smoke-diving the average heart rate was 150 +/- 13 beats/min (79 +/- 6% of maximal heart rate attained in a cycle-ergometer test), and the peak heart rate was 180 +/- 13 beats/min (95 +/- 6% of maximal heart rate). The estimated oxygen consumption was 2.4 +/- 0.5 L/min (60 +/- 12% of maximal oxygen consumption). Neither ability to tolerate stress (as determined by the instructors) nor previous experience in smoke-diving tasks seemed to influence the heart rate or estimated oxygen consumption during experiment. Smoke-diving was physically very demanding even for the young and fit subjects, showing the importance of regular evaluation of the health and physical fitness of every firefighter who has to carry out smoke-diving tasks.
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Affiliation(s)
- S Lusa
- Department of Physiology, Institute of Occupational Health, Vantaa, Finland
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Smolander J, Bar-Or O, Korhonen O, Ilmarinen J. Thermoregulation during rest and exercise in the cold in pre- and early pubescent boys and in young men. J Appl Physiol (1985) 1992; 72:1589-94. [PMID: 1592752 DOI: 10.1152/jappl.1992.72.4.1589] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Eight minimally dressed pre- and early pubescent boys (age 11-12 yr) and 11 young adult men (age 19-34 yr) rested for 20 min and exercised on a cycle ergometer for 40 min at approximately 30% of their maximum oxygen consumption (VO2max) at 5 degrees C. To quantify the added increase in metabolic rate because of cold, a separate test was carried out at 21 degrees C at rest and at equal work rates as in the cold. Both groups were similar in subcutaneous fat thickness and VO2max per kilogram body weight. Rectal temperature increased slightly during the exposure to the cold, but no significant difference was observed between the boys and men. In the cold, the boys had lower skin temperatures than the adults in their extremities but not in the trunk. The boys increased their metabolic rates in the cold more than did the men. As a result, the boys maintained their core temperature as effectively as the adults. Similar age-related differences in thermoregulatory responses to cold were observed when two boys and two men with equal body sizes were compared. Our results suggest that there may be maturation-related differences in thermoregulation in the cold between children and adults.
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Affiliation(s)
- J Smolander
- Department of Physiology, Institute of Occupational Health, Vantaa, Finland
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Abstract
The purpose of the present study was to examine whether intensity of exercise affects skin blood flow response to exercise. For this purpose, six healthy men cycled, in a random order on different days, for 15 min at 50, 60, 70, 80, and 90% of their maximum oxygen consumption (VO2max) at a room temperature of 25 degrees C. At the end of exercise, esophageal temperature (Tes) averaged 37.4 +/- 0.2, 37.7 +/- 0.2, 37.9 +/- 0.2, 38.6 +/- 0.3, and 38.9 +/- 0.4 degrees C (SE) at the 50, 60, 70, 80, and 90% work loads, respectively. At the two highest work loads, no steady state was observed in Tes. Skin blood flow was estimated by measuring forearm blood flow (FBF) with strain-gauge plethysmography and by laser-Doppler flowmetry on the upper back. Both techniques showed that skin blood flow response to rising Tes was markedly reduced at the 90% work load compared with other work loads. At the end of exercise, FBF averaged 7.5 +/- 1.7, 10.7 +/- 3.1, 9.6 +/- 2.1, 11.3 +/- 2.6, and 5.4 +/- 1.3 (SE) ml.min-1.100 ml-1 (P less than 0.01) at the 50, 60, 70, 80, and 90% VO2max work loads, respectively. The corresponding values for Tes threshold for cutaneous vasodilation (FBF) were 37.42 +/- 0.16, 37.48 +/- 0.13, 37.59 +/- 0.13, 37.79 +/- 0.19, and 38.20 +/- 0.22 degrees C (P less than 0.05) at 50, 60, 70, 80, and 90% VO2max, respectively. In two subjects, no cutaneous vasodilation was observed at the 90% work load.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- J Smolander
- Department of Physiology, Institute of Occupational Health, Vantaa, Finland
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Smolander J, Ilmarinen R, Korhonen O. An evaluation of heat stress indices (ISO 7243, ISO/DIS 7933) in the prediction of heat strain in unacclimated men. Int Arch Occup Environ Health 1991; 63:39-41. [PMID: 1856022 DOI: 10.1007/bf00406196] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The ISO 7243 heat stress standard based on the wet bulb globe temperature (WBGT) heat stress index and the analytical standard proposal ISO/DIS 7933 were evaluated in eight physically trained and eight untrained, unacclimated men during prolonged light exercise carried out while wearing industrial work clothing. The exercise tests were done in a thermoneutral (20 degrees C/40%), a warm humid (30 degrees C/80% humidity), and a hot dry (40 degrees C/20% humidity) environment. Both of the standards were effective in predicting the excessive thermal strain observed in the dry and humid heat (WBGT, 28 degrees C). In dry heat, neither of the standards took into account the higher sweating capacities of the physically trained men. The large inter-individual variability in the physiological responses to heat stress questioned the calculations of definite allowable exposure times (ISO/DIS 7933).
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Affiliation(s)
- J Smolander
- Institute of Occupational Health, Laajaniityntie, Vantaa, Finland
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Hurri H, Mellin G, Korhonen O, Harjula R, Härkäpää K, Luoma J. Aerobic capacity among chronic low-back-pain patients. J Spinal Disord 1991; 4:34-8. [PMID: 1839667] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The role of aerobic capacity (maximal oxygen uptake, VO2max) in connection with chronic low-back pain was assessed in a study mainly designed to evaluate the outcome of inpatient and outpatient treatment of low-back pain. A total of 245 subjects (ages 35-54 years, 71% men)--81 inpatients, 88 outpatients, and 76 controls--who had chronic low-back pain but who were still working, performed maximal graded bicycle ergometer tests four times during the follow-up of 30 months. In every group the estimated VO2max was on the level of the reference values of healthy persons. There were no significant changes in the VO2max in any of the intervention groups during the follow-up period. The correlation analyses showed no connection between aerobic capacity and pain or disability caused by chronic low-back pain. Among several components of physical fitness, aerobic capacity had no predictive value in the course of low-back pain.
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Affiliation(s)
- H Hurri
- Rehabilitation Foundation, Helsinki, Finland
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Smolander J, Korhonen O, Ilmarinen R. Responses of young and older men during prolonged exercise in dry and humid heat. Eur J Appl Physiol Occup Physiol 1990; 61:413-8. [PMID: 2079060 DOI: 10.1007/bf00236061] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Eight young, sedentary men (aged 34 years, SD 3) and six older moderately active, unacclimated men (aged 57 years, SD 2) walked on a treadmill at 30% of their maximum oxygen consumption up to 3.5 h in a thermoneutral [dry bulb temperature (Td) 21 degrees C, relative humidity (r.h.) 43%)], a warm humid (Tdb 30 degrees C, r.h. 80%) and a hot dry (Tdb 40 degrees C, r.h. 20%) environment while wearing ordinary working clothes (0.7 clo). Their oxygen consumption, heart rate (fc), rectal (Tre) and mean skin temperature (Tsk), sweat rate (SR), and evaporative rate (ER) were measured during the tests. The ratings of thermal sensation (TS) and perceived exertion (RPE) were assessed using standard scales. In the heat stress tests, the number of experiments discontinued did not significantly differ between the two groups. The mean levels and end-exercise values of Tre, Tsk, fc, TS and RPE were not significantly different between the young and older subjects in any of the environments. In the warm humid environment, however, the Tre and RPE of the older subjects increased continuously (P less than 0.05) during the test compared to the young subjects. No significant difference between the groups was observed in SR or in ER. In the hot dry environment, however, the ER of older men increased more slowly compared to the young men. In spite of some time-related differences observed in Tre, RPE, and ER, the older subjects did not exhibit higher fc during exercise in the heat, they were not more hyperthermic and their performance times were similar to the young subjects.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- J Smolander
- Institute of Occupational Health, Department of Physiology, Vantaa, Finland
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Aatola S, Färkkilä M, Pyykkö I, Korhonen O, Starck J. Vibration perception threshold of forest worker's finger during temporary obstructed blood circulation. Int Arch Occup Environ Health 1990; 62:451-3. [PMID: 2246063 DOI: 10.1007/bf00379062] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Vibration detection threshold (VPT) of 149 professional forest workers was measured during a compulsory annual health examination. The authors' earlier developed measuring method for VPT of finger was modified. The blood circulation of the hand was obstructed for 6 min and VPT was measured 4 min after releasing the obstruction. VPTs of all forest workers increased during obstruction. In forest workers suffering from decreased hand grip force (decreased HGF) the increase of VPT differed significantly from forest workers without symptoms, and VPT in the former group still increased after releasing the obstruction. VPT remained also at the raised level after releasing the obstruction with forest workers suffering from vibration-induced white finger (VWF). Nevertheless, on an individual basis even the modified measuring method failed to discriminate subjects without symptoms from those with symptoms of hand-arm vibration syndrome. The raised VPT and sensitivity for obstruction of blood circulation suggest that the reason for decreased HGF in forest workers may be a consequence of an injury in the peripheral nerves.
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Affiliation(s)
- S Aatola
- Instrument Laboratory, Technical Research Centre of Finland, Espoo
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Aatola S, Färkkilä M, Pyykkö I, Korhonen O, Starck J. Measuring method for vibration perception threshold of fingers and its application to vibration exposed workers. Int Arch Occup Environ Health 1990; 62:239-42. [PMID: 2347647 DOI: 10.1007/bf00379440] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
A measuring method for the vibration perception threshold (VPT) of fingers has been developed. The VPTs of 118 and 149 professional forest workers were measured during a compulsory annual health examination in 1979 and 1983, respectively. Also the VPTs of eight pedestal grinders, who were suffering vibration-induced white finger (VWF), were measured in 1979 and 1983. The control group consisted of 20 research workers who had no vibration exposure in the past and no symptoms in their hands. The measuring system for VPT gave repeatable results. The frequency of the most sensitive VPT of vibration exposed workers alternated between 63 and 125 Hz instead of 125 Hz of subjects without vibration exposure. The VPT of the pedestal grinders and forest workers with decreased hand grip force and with vibration-induced white finger were significantly higher than those of the controls. The VPTs of the forest workers decreased slightly and that of the grinders increased from 1979 to 1983. In spite of long vibration exposure in the past and continuing lower level vibration exposure, the increased VPT of forest workers does not seem to be permanent.
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Affiliation(s)
- S Aatola
- Technical Research Centre, Espoo, Finland
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Abstract
Neurological findings were examined in 186 forestry workers with a mean exposure to chain saw vibration of 16.6 hours. The prevalence of active vibration induced white fingers was 5%, parethaesias of the hands 53%, and muscle weakness 13%. Clinical polyneuropathy was observed in 16 forestry workers in the hands (7.5%) which did not correlate with alcohol consumption. Seventy nine forestry workers of the total population were selected for electromyographic examination. Generalised EMG based polyneuropathy in the hands was observed in only two of the 79 forestry workers (2.5%). The carpal tunnel syndrome was found in 20 of the 79 forestry workers (26%). Headache and vertigo were not linked with exposure to vibration in forestry and a significant part of the numbness reported may be due to the carpal tunnel syndrome. Sensorimotor polyneuropathy is rare among forestry workers. The rise in the vibration detection thresholds was linked to the carpal tunnel syndrome.
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Affiliation(s)
- M Färkkilä
- Department of Neurology, University Hospital of Helsinki, Finland
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Heinonen E, Färkkilä M, Forsström J, Antila K, Jalonen J, Korhonen O, Pyykkö I. Autonomic neuropathy and vibration exposure in forestry workers. Br J Ind Med 1987; 44:412-6. [PMID: 3606971 PMCID: PMC1007843 DOI: 10.1136/oem.44.6.412] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
The variation in heart rate (HRV) at rest and during deep breathing (6 cycles a minute) of 88 professional lumber jacks was studied using a computer technique. The traditional indexes of HRV (CV, CVS, MEAN) were calculated and the spectral components of the HRV were also computed. There was a significant difference (p less than 0.001) between the HRV indexes during the deep breathing test in those with the shortest (CV = 10.1 +/- 1.1) and those with the longest (CV V 6.2 +/- 0.4) exposures to vibration. The values of the HRV indexes decreased with age, but multiple regression analysis showed that the total exposure time to vibration had an independent negative association with the HRV. There were significant differences in all the frequency bands (frequency related power, FRP) of the heart rate between those with the longest and those with the shortest exposures. The HRV during a deep breathing test is associated with the activity of the parasympathetic nervous system and is decreased in autonomic neuropathies. Our results suggest that prolonged exposure to the vibration caused by a chain saw has a negative effect on the parasympathetic activity and thus causes autonomic dysfunction.
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Smolander J, Ilmarinen R, Korhonen O, Pyykkö I. Circulatory and thermal responses of men with different training status to prolonged physical work in dry and humid heat. Scand J Work Environ Health 1987; 13:37-46. [PMID: 3576143 DOI: 10.5271/sjweh.2083] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Eight physically trained and eight untrained, unacclimated men walked on a treadmill at 30% of their maximum oxygen consumption up to 3.5 h in a thermoneutral [20 degrees C/40% relative humidity (RH)], a warm humid (30 degrees C/80% RH), and a hot dry (40 degrees C/20% RH) environment while wearing industrial work clothing. Their oxygen consumption, rectal and skin temperatures, sweating, cardiac output, heart rate, stroke volume, and peripheral blood pressure were measured during the tests. Thirteen of the 32 heat stress tests were prematurely stopped due to high rectal temperature, high heart rate, subjective fatigue, or heat syncope. The physiological strain, as indicated by the rectal temperature and heart rate, was not significantly different between the warm humid and hot dry environments (wet bulb globe temperature approximately 28 degrees C). The rectal temperature and heart rate responses of the physically trained and untrained subjects did not differ in any of the environments. In the heat, the heart rate was significantly higher than in the thermoneutral environment, but because of the markedly reduced stroke volume the average cardiac output was not different between the three environments. The impaired work performance in the heat seemed mainly to be related to the circulatory instability accompanying the increased cutaneous circulation.
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Smolander J, Kolari P, Korhonen O, Ilmarinen R. Skin blood flow during incremental exercise in a thermoneutral and a hot dry environment. Eur J Appl Physiol Occup Physiol 1987; 56:273-80. [PMID: 2952497 DOI: 10.1007/bf00690892] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Eight physically fit men performed two incremental bicycle ergometer tests, one in an ambient temperature of 25 degrees C and the other at 40 degrees C. Oesophageal temperature (Tes) increased continuously throughout the tests up to 38.0 and 38.3 degrees C, respectively. In both environments, forearm blood flow (plethysmography) was linearly related to Tes above the Tes threshold for vasodilation, but at the heaviest work loads this relationship was clearly attenuated and therefore indicated skin vasoconstriction, which tended to be more pronounced at 25 degrees C. During recovery at 25 degrees C, in some subjects the forearm blood flow increased above the levels observed at the end of the graded exercise in spite of a decreasing Tes. Skin blood flow, measured by laser Doppler flow meter at the shoulder, was quantitatively different but, on average, seemed to reveal the same response pattern as the forearm blood flow. In spite of the higher level of skin blood flow in the heat, blood lactate accumulation did not differ between the two environments. The present results suggest that there is competition between skin vasoconstriction and vasodilation at heavy work rates, the former having precedence in a thermoneutral environment to increase muscle perfusion. During short-term graded exercise in a hot environment, skin vasoconstriction with other circulatory adjustments seems to be able to maintain adequate muscle perfusion at heavy work levels, but probably not during maximum exercise.
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Smolander J, Kolari P, Korhonen O, Ilmarinen R. Aerobic and anaerobic responses to incremental exercise in a thermoneutral and a hot dry environment. Acta Physiol Scand 1986; 128:15-21. [PMID: 3766171 DOI: 10.1111/j.1748-1716.1986.tb07944.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
In an investigation of the effect of acute heat exposure on aerobic and anaerobic metabolism, eight unacclimated men performed two incremental bicycle ergometer tests in random order, once under thermoneutral conditions (25 degrees C) and once in a hot dry (40 degrees C) environment. Oxygen consumption (VO2) and pulmonary ventilation were measured every minute. Fingertip blood samples were taken at each work level for blood lactate (LA) determination. Compared to the results at 25 degrees C, the mean VO2 was significantly (P less than 0.01) lower during exercise at 40 degrees C. In the hot dry environment the blood lactate threshold was slightly reduced in four subjects, but neither the average peak nor the post-exercise blood LA values differed from the findings at 25 degrees C. During the exercise-heat stress, the ventilatory threshold did not change significantly. The results indicated that, during relatively short-term incremental exercise in a hot environment, almost adequate muscle metabolism can be maintained.
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Abstract
Hand-grip force was measured in 63 professional lumberjacks in 1978 and again in 1980. Lumberjacks with vibration-induced white fingers (VWF) had lost 21% of their muscle force during the two years. Lumberjacks with no hand-arm symptoms had lost 5% of their muscle force in the same time period. Lumberjacks with subjectively diminished hand muscle force had a slight increase in muscle force during the follow-up time. These results suggest that long-term exposure to vibration causes a decrease in muscle force.
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Pyykkö I, Färkkilä M, Korhonen O, Starck J, Jäntti V. Cold provocation tests in the evaluation of vibration-induced white finger. Scand J Work Environ Health 1986; 12:254-8. [PMID: 3775310 DOI: 10.5271/sjweh.2142] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Two types of cold provocation tests, a classical test with immersion of the hand in cold water and the evaluation of finger systolic blood pressure (FSBP) during local cooling, were administered to forest workers. Raynaud's phenomenon in the classical test correlated positively with the number of disabled phalanges, recovery time, and frequency of attacks. It did not correlate with the severity of paresthesia of the hands and arms. Repetition of the test enhanced the number of positive results. A significant reduction in the FSBP was observed in 22 and 25% of the subjects with inactive and active forms of vibration-induced white finger (VWF), respectively. In the same groups of subjects the classical cold provocation test yielded positive results in 7 and 25% of the subjects, respectively. A cold provocation test was found to produce a positive result even some years after the cessation of VWF attacks. The rather low severity of VWF among the examined subjects may explain the lack of positive test results. FSBP measurement was not superior to cold provocation by water immersion, but it is recommended because it is easier to standardize and more convenient for the test subject.
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Pyykkö I, Kolari P, Färkkilä M, Starck J, Korhonen O, Jäntti V. Finger peripheral resistance during local cold provocation in vasospastic disease. Scand J Work Environ Health 1986; 12:395-9. [PMID: 3775329 DOI: 10.5271/sjweh.2123] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Finger systolic blood pressure (FSBP), finger arterial inflow (FAI), finger venous opening pressure (FVOP), and finger peripheral resistance (FPR) were evaluated in 56 workers exposed to chain-saw vibration. Twenty-one of the workers were free from vibration-induced white finger (VWF). In 17 subjects VWF had ceased; 12 of the subjects had active VWF; 6 subjects had Raynaud's disease. The subjects were examined in a supine position under thermoneutral conditions with strain-gauge plethysmography. Cold provocation of the finger caused a significant reduction in FSBP in the groups with Raynaud's disease and active VWF. The finger circulation of the subjects with active VWF and that of those with Raynaud's disease showed a significantly reduced FAI when compared with that of the symptom-free referents. Finger cooling produced a gradual reduction in the FVOP and a significantly increased FPR of the subjects with active VWF and in those with Raynaud's disease. FPR was already increased in the Raynaud's disease group at the beginning of the test, whereas it increased in the VWF group as the temperature fell. The results suggest that in Raynaud's disease the fault is in the level of activity of the sympathetic outflow and in VWF it is peripheral mechanisms controlling the vessel tone.
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Pyykkö I, Korhonen O, Färkkilä M, Starck J, Aatola S, Jäntti V. Vibration syndrome among Finnish forest workers, a follow-up from 1972 to 1983. Scand J Work Environ Health 1986; 12:307-12. [PMID: 3490688 DOI: 10.5271/sjweh.2148] [Citation(s) in RCA: 35] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
A longitudinal survey on the prevalence of vibration syndrome among professional forest workers was conducted from 1972 (118 workers) to 1983 (206 workers). The prevalence of vibration-induced white finger (VWF) was 40% among the workers in 1972; it gradually declined to 5% in 1983. Three new workers developed VWF symptoms during the follow-up period. They had only used saws equipped with antivibration handles. The prevalence of VWF has decreased mainly due to the reduction of chain-saw vibration. The prevalence of paresthesias of the hands and arms declined from 78% in 1972 to 37% in 1976, and then increased to 51% in 1983. The recent increase was thought to be due to static muscle load and the ageing of the workers. No correlation was found between the severity of VWF and peripheral nerve symptoms. No significant changes in muscle fatigue occurred during the follow-up period; it was present in about 10-15% of the workers. The forest workers subjectively assessed musculoskeletal load and strain as being more harmful than the symptoms of vibration syndrome. The preventive measures aimed at reducing chain-saw vibration, implemented since 1970, have been beneficial and explain the decreased prevalence of VWF.
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Louhevaara V, Smolander J, Korhonen O, Tuomi T. Effects of industrial respirators on breathing pattern at different work levels. Eur J Appl Physiol Occup Physiol 1986; 55:142-6. [PMID: 3457704 DOI: 10.1007/bf00714996] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
The effects of a filtering device and an air-line apparatus on breathing pattern were studied in healthy men with different physical characteristics and work capacity. The subjects comprised nine construction workers aged 35-44, and nine firemen aged 21-35. The construction workers' mean maximal oxygen consumption (VO2max) was 34.5 ml min-1 kg-1, the firemen's 66.9 ml min-1 kg-1. Breathing pattern was analyzed for its components, inspiratory time, expiratory time, breathing frequency, tidal volume, and pulmonary ventilation at rest, during two submaximal treadmill walks when the subjects' absolute work load was equal, and during recovery. Neither the filtering device nor the air-line apparatus had a significant effect on breathing pattern when compared with the control values measured twice with a low-resistance breathing valve. A significantly longer expiratory time, lower breathing frequency, and smaller pulmonary ventilation were found for the firemen with the breathing valve and the industrial respirators. The breathing pattern of the construction workers and the firemen differed, but the alterations were not induced by the use of the filtering device or the air-line apparatus when studied at aerobic work levels up to 60% VO2max.
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Smolander J, Louhevaara V, Korhonen O. Physiological strain in work with gas protective clothing at low ambient temperature. Am Ind Hyg Assoc J 1985; 46:720-3. [PMID: 4083254 DOI: 10.1080/15298668591395625] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Wearing an impermeable gas protective suit (Dräger 500 or 600) and a self-contained breathing apparatus (Dräger PA 80; total weight 27 kg (59.5 lb], seven experienced firemen and one mechanic performed simulated repair and rescue tasks in a chemical plant. The subjects' mean (+/- SD) age, height, weight and estimated maximal oxygen consumption were: 36 +/- 4 years; 181 +/- 6 cm; 83 +/- 8 kg; and 42 +/- 5 mL/min/kg, respectively. The operations took place outdoors (ambient temperature 2.0 degrees C (35.6 degrees F), wind velocity 0-4 m/s). The total work time averaged 37 minutes. During tasks of search, handling vents, and sawing and replacing bolts, the mean (+/- SE) heart rates measured by a Depex recording device were 146 +/- 2, 148 +/- 2, and 147 +/- 5 beats/min, respectively. The mean rectal temperature increased 0.8 degrees C during the whole work period. Weight loss due to sweat averaged 300 g. In conclusion, typical tasks with gas protective clothing caused marked physiological strain among subjects in average physical condition even though the thermal strain was relatively low because the weather was cool. The results emphasized the need to evaluate physical fitness during the periodic check-ups of workers who may have to use gas protective clothing.
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Louhevaara V, Tuomi T, Smolander J, Korhonen O, Tossavainen A, Jaakkola J. Cardiorespiratory strain in jobs that require respiratory protection. Int Arch Occup Environ Health 1985; 55:195-206. [PMID: 3997263 DOI: 10.1007/bf00383753] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Twenty-one workers in the construction, foundry, shipyard, and metal industries, and nine firemen were studied in jobs that require the regular use of various industrial respirators. The subjects' heart rates (HR) were continuously recorded during 1 to 2 workshifts or during special tasks. Their oxygen consumption (VO2) and ventilation rates were measured during main work phases. The subjects' VO2max were determined by a submaximal bicycle-ergometer test. In construction and industrial jobs, when a filtering device or an air-line apparatus was worn, the subjects' mean HR-values ranged from 66 to 132 beats min-1, which is equivalent to a relative aerobic strain of 12 to 57% VO2max. In smog-diving and repair and rescue tasks with self-contained breathing apparatus and protective clothing, the corresponding mean values were 142 to 160 beats min-1 and 54-74% VO2, respectively. The field results were compared with those measured in the laboratory with the same type of respirator. The suitability of different respirators in practical work situations was then evaluated, as were the physical qualifications required of the wearer.
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Abstract
The neurological findings of 217 forestry workers were evaluated during a compulsory annual health examination. Vibration detection thresholds were determined for the left hand and foot. The handgrip forces were measured for both hands. A reduction in the vibration detection threshold or handgrip force was not associated with clinical neuropathy. Polyneuropathy was found in 4% of the lumberjacks whereas neuropathy restricted to the arms was found in 7.5% of the lumberjacks. The neuropathic findings were not linked with alcohol consumption but were associated with a history of numbness in the hands and diminished muscle force. The findings support the concept that local vibration can cause neuropathy in the arms, but the mechanism of vibration-induced neuropathy still remains uncertain.
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Louhevaara V, Smolander J, Tuomi T, Korhonen O, Jaakkola J. Effects of an SCBA on breathing pattern, gas exchange, and heart rate during exercise. J Occup Med 1985; 27:213-6. [PMID: 3981278] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The effects of a pressure demand-type self-contained breathing apparatus (SCBA) (total weight, 15.5 kg) on breathing pattern, gas exchange, and heart rate were studied in 13 firemen. The subjects performed sequential progressive exercise tests on a treadmill both without and with an SCBA. The use of an SCBA consistently limited tidal volume. During submaximal exercise oxygen consumption and heart rate increased remarkably more with the SCBA than without it. Four subjects reached their maximal heart rate with the SCBA. Their mean ventilation rate was 68% and oxygen consumption was 83% of the maximal values attained without the SCBA. The shoulder harness of the heavy SCBA prevented free motion of the thorax, affecting the regulation of breathing, and thus seriously disturbed ventilation and gas exchange, particularly at heavier exercise levels.
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Louhevaara V, Tuomi T, Korhonen O, Jaakkola J. Cardiorespiratory effects of respiratory protective devices during exercise in well-trained men. Eur J Appl Physiol Occup Physiol 1984; 52:340-5. [PMID: 6539691 DOI: 10.1007/bf01015224] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
The effects of a filtering device, an air-line breathing apparatus and a self-contained breathing apparatus ( SCBA ) on pulmonary ventilation, oxygen consumption and heart rate were studied in 12 well-trained firemen aged 21-35 years. Their average maximal oxygen consumption (VO2 max) was 64.9 ml X min-1 X kg-1. Sequential tests without and with the respirator were performed on a treadmill. The continuous test contained five components, each of which lasted 5 min: sitting at rest, walking at 20%, 40%, and 60% of the individual VO2 max, and recovery sitting. During the higher submaximal work levels and recovery, ventilation, heart rate, and oxygen consumption in particular increased more with respirators than without them. At the highest work level the increments in oxygen consumption caused by the respirators were 13%, (8.7 ml X min-1 X kg-1), 7% (4.4 ml X min-1 X kg-1), and 20% (12.7 ml X min-1 X kg-1) of VO2 max. All three respirators hampered respiration, resulting in hypoventilation. The additional effort of breathing and the weight of the apparatus (15 kg with the SCBA ) increased the subjects' cardiorespiratory strain so clearly that the need for rest periods and the individual's work capacity when the respirators are worn must be carefully considered, particularly with the SCBA .
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Smolander J, Louhevaara V, Tuomi T, Korhonen O, Jaakkola J. Cardiorespiratory and thermal effects of wearing gas protective clothing. Int Arch Occup Environ Health 1984; 54:261-70. [PMID: 6490185 DOI: 10.1007/bf00379055] [Citation(s) in RCA: 31] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Six healthy men aged 25 to 37 walked on a treadmill at work levels of 21 and 41% of their VO2max for 25 to 30 min wearing gas protective clothing (GPC) consisting of an impermeable suit with a self-contained breathing apparatus (total weight 25 kg) or shorts (control tests, CT) in a temperate environment (ta 24.3 degrees C +/- 1.0 degrees C, rh 30-50%). When the GPC was worn at 21 and 41% VO2max, the most prominent increases, compared with the CT, were noted in the heart rate (means +/- SE, 120 +/- 5 vs 76 +/- 3 beats min-1 and 171 +/- 5 vs 103 +/- 3 beats min-1), mean skin temperature (36.1 +/- 0.2 vs 31.3 degrees C +/- 0.1 degree C and 36.9 +/- 0.3 vs 30.9 degrees C +/- 0.4 degrees C) and sweat rate (473 +/- 51 vs 70 +/- 23 g m-2 h-1 and 766 +/- 81 vs 135 +/- 18 g m-2 h-1) indicating a high cardiovascular and thermoregulatory strain, which was not decreased by ventilating the suit with an air flow of 281 min-1 at 41% VO2max. The ventilation, oxygen consumption and production of carbon dioxide increased in relation to the extra weight of the GPC, partly dependent on the dynamic work level. It was concluded that the increase in the physiological load caused by the GPC was so high that the work-rest regimens, workers' level of physical fitness, cardiovascular health and heat tolerance should be considered whenever gas protective clothing is used.
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Juntunen J, Huuskonen MS, Matikainen E, Kemppainen R, Suoranta H, Tukiainen P, Korhonen O, Järvisalo J, Partanen T. Asbestosis, the nervous system and cancer. Ann Acad Med Singap 1984; 13:353-60. [PMID: 6497337] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Asbestosis patients have a high cumulative risk of cancer: four of ten asbestosis patients develop cancer. Paraneoplastic involvement of the nervous system, peripheral neuropathy in particular, is often encountered in cancer patients, even at very early stages of the disease. In order to estimate the occurrence of paraneoplastic neuropathy among asbestosis patients, we formed a small cohort (115 asbestosis patients, mean age 56 years, mean duration of exposure to asbestos 21 years) in 1979. Neurological examination revealed slight peripheral neuropathy in 44 (39%) of the patients, 24 (22%) of whom also had central nervous system signs (disturbances in gait and posture, memory and fine movements). The prevalence of peripheral neuropathy among asbestosis patients was higher than among various referent patients (fibrosing alveolitis, diagnosed solvent poisoning and gynaecological carcinoma). No significant differences were found between the patients with and without peripheral neuropathy regarding the following parameters: pulmonary function tests, tumour markers (CEA, ferritin, beta-2-microglobulin), antinuclear antibodies, C3, C4 and circulating immune complexes. Nevertheless, at group level, the asbestosis patients had increased levels of the three tumour markers. Estimates based on the data accumulated so far (10 cancer patients) show that within three years we shall probably have a sufficient number of cancer cases to draw some conclusions about the value of neuropathy in the early diagnosis of occupational cancer.
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Huuskonen MS, Husman K, Järvisalo J, Korhonen O, Kotimaa M, Kuusela T, Nordman H, Zitting A, Mäntyjärvi R. Extrinsic allergic alveolitis in the tobacco industry. Br J Ind Med 1984; 41:77-83. [PMID: 6318802 PMCID: PMC1009239 DOI: 10.1136/oem.41.1.77] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
A total of 57 subjects who had been exposed to mould dust in the tobacco industry were studied. Their working environment showed exposure to spores of different moulds, and 29 subjects (51%) showed antibodies against one or more of the microbes. Fifteen (26%) had work related respiratory symptoms. Eight (14%) showed slight radiographic pulmonary fibrosis. Spirometry showed a tendency toward restriction and obstruction, especially in small airways. Diffusion capacity was decreased in 18% of the workers. Three clinical cases of typical allergic alveolitis were also found. All this suggests that exposure of spores of different moulds (especially Aspergillus fumigatus) in the manufacture of tobacco products may induce symptoms and signs relating to extrinsic allergic alveolitis.
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Smolander J, Louhevaara V, Tuomi T, Korhonen O, Jaakkola J. Reduction of isometric muscle endurance after wearing impermeable gas protective clothing. ACTA ACUST UNITED AC 1984; 53:76-80. [PMID: 6542505 DOI: 10.1007/bf00964694] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The isometric endurance of forearm muscles at 40% maximum voluntary contraction was measured in six healthy male subjects, after they had walked for 25-30 min on a treadmill while wearing an impermeable gas protective suit and a self-contained breathing apparatus at a light (21% VO2 max), and a moderate 41% VO2 max) work level. The mean endurance times were 12% (NS) and 24% (P less than 0.01) shorter than the average control value after exercise for the light and moderate work levels, respectively. These changes were accompanied by an increased heart rate, and rectal and skin temperatures. Ventilating the suit with an air flow of 181 . min-1 at the moderate work level did not significantly affect isometric endurance (decreased 27%), heart rate or body temperatures. It was concluded, that muscular performance capacity is reduced after wearing gas-protective clothing in a temperate environment, presumably due to the increased muscle temperature, and this should be considered in scheduling work times and rest periods.
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Futatsuka M, Pyykkö I, Färkkilä M, Korhonen O, Starck JP. Blood pressure, flow, and peripheral resistance of digital arteries in vibration syndrome. Br J Ind Med 1983; 40:434-41. [PMID: 6626472 PMCID: PMC1009217 DOI: 10.1136/oem.40.4.434] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
The peripheral circulation was studied in 19 lumberjacks and in 12 control subjects. Twelve of the lumberjacks were free from vascular symptoms and seven had vibration induced white finger (VWF). Using the strain-gauge plethysmographic technique, the digital circulation was examined at rest, during cooling of the upper body, and during heating of the upper body. At rest and during vasodilatation no significant differences were found between the lumberjacks and the controls. During reflexive vasoconstriction, digital blood flow in the upper body was more reduced in lumberjacks with VWF than in control subjects. Furthermore, digital blood pressure of the lumberjacks with VWF fell more than in the control group. The peripheral resistance also increased more, but this difference was not statistically significant. There was no evidence that the exaggerated vasoconstriction of VWF resulted from a narrowing of the lumen of arterioles due to hypertrophy of the vessel wall. The present findings suggest that VWF is produced by the highly sensitive responsiveness of the affected vessel to normal vasoconstrictor stimuli.
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Härkönen H, Nordman H, Korhonen O, Winblad I. Long-term effects of exposure to sulfur dioxide. Lung function four years after a pyrite dust explosion. Am Rev Respir Dis 1983; 128:890-3. [PMID: 6638677 DOI: 10.1164/arrd.1983.128.5.890] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
The lung function of 7 men accidentally exposed to sulfur dioxide (SO2) in a pyrite dust explosion was followed for 4 yr. The greatest decrease in forced vital capacity, forced expiratory volume in one second, and maximal midexpiratory flow was observed 1 wk after the accident. After about 3 months no further decrement occurred. The pattern of spirometric findings was obstructive in 6 and restrictive in 1 of the patients. Four years after the accident a reversible obstruction of the bronchi was still observable in 3. Four patients reacted positively to the histamine challenge test. Two patients either did not respond to bronchodilator or did not react to histamine. The results suggest that bronchial hyperreactivity is a frequent sequela after exposure to high concentrations of SO2. The hyperreactivity may persist for several years.
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Abstract
At one Finnish foundry all the workers had typical symptoms of vibration induced white finger (VWF) after they began using a new type of pedestal grinding machine. The objectives of this study were to establish the severity of the symptoms and the difference in vibration exposure between the new and the old machines. Vibration detection thresholds and grip forces were measured, as well as the vibration in the casting and in the wrist simultaneously. The mean latency for VWF among the grinders was 10.3 months after the change of pedestal grinding machines. All the grinders had numbness in their hands. The vibration detection threshold was significantly higher for the grinders than for their referents. At the same circle speed, the new wheels caused vibration levels up to 12 dB more than the old wheels. The circle speed had a slight influence on the vibration. The vibration levels of light (0.5 kg) casting were up to 25 dB higher than the heavy (5 kg) casting. The use of a pneumatic pressing device decreased the vibration levels in the wrist by 5-10 dB. The increase in vibration, which occurred when the new wheels were taken into use, was too small to explain such a dramatic outbreak of VWF. This led to the conclusion that some other feature such as the impulse character of the vibration also contributed to the effects of vibration.
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Huuskonen MS, Tossavainen A, Koskinen H, Zitting A, Korhonen O, Nickels J, Korhonen K, Vaaranen V. Wollastonite exposure and lung fibrosis. Environ Res 1983; 30:291-304. [PMID: 6299727 DOI: 10.1016/0013-9351(83)90215-3] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Wollastonite is a naturally occurring acicular or fibrous metasilicate used in ceramics and as a substitute for asbestos in some applications. Wollastonite fibers are rather similar in form, length, and diameter to amphibole asbestos fibers but mineralogically they are different. Dust measurements in both the Finnish limestone--wollastonite quarry and in the flotation plant yielded high concentrations of both total dust and respirable fibers in some operational stages. The clinical study comprised a total of 46 men who had been exposed to wollastonite at the quarry for at least 10 years. Three of the fifteen nonsmokers showed chronic bronchitis. Radiographs revealed slight lung fibrosis among fourteen men, and slight bilateral pleural thickening among thirteen men. Their sputum specimens were normal. Spirometry and nitrogen single breath tests indicated the possibility of small airways disease.
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Grahne B, Poppius H, Viljanen AA, Korhonen O, Rinne J. Surgical treatment of chronic laryngeal stenosis secondary to vocal cord paralysis: pre and postoperative evaluation of ventilatory function. Laryngoscope 1983; 93:163-7. [PMID: 6823184 DOI: 10.1288/00005537-198302000-00006] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Thirteen patients with chronic laryngeal stenosis were operated upon with total excision of stenotic scar tissue, enlargement of the lumen by sectioning the back and front wall of the larynx, and application of an indwelling Teflon prosthesis for 4 months. The stenosis was in many cases caused by long-standing recurrent paralysis complicated by attempted surgical correction of the stenosis. Following operation, the specific airway conductance increased in all patients (mean +/- SD pre and postoperative values 0.51 +/- 0.30 and 1.12 +/- 0.51 kPa-1.s-1, respectively). The FIV1/FVC ratio was determined in 9 patients and an increase was postoperatively noted in all of them (mean +/- SD pre and postoperative values 43 +/- 17 and 76 +/- 13%, respectively). The physiological findings confirmed the excellent clinical results of the treatment.
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Korhonen O, Juntunen J, Huuskonen M. Lung function and nervous system involvement in asbestosis. Eur J Appl Physiol Occup Physiol 1983; 50:207-12. [PMID: 6297883 DOI: 10.1007/bf00422159] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
A group of 115 patients with asbestosis of the lungs was tested in detail for neurological functions and lung functions in order that any possible impaired pulmonary function and neurological signs (especially peripheral neuropathy) could be discovered. Attention was also paid to finding out whether peripheral neuropathy, which is frequently encountered among asbestosis patients, had any role in decreased pulmonary function. A slight trend towards lowered spirometrical values (vital capacity, forced expiratory volume in one second, maximal mid-expiratory flow and maximal expiratory flow at 25% of vital capacity) was found for the group of patients with peripheral neuropathy. No differences in diffusing capacity were found between the groups of patients either with or without peripheral neuropathy. We concluded that the spirometrical findings are more indicative of a parallel phenomenon than a causal factor. Nor was the involvement of the central nervous system associated with decreased pulmonary function. In short, the pulmonary dysfunction of our asbestosis patients did not appreciably contribute to the occurrence of nervous system involvement, whether central or peripheral.
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