Forskning och publikationer

 

A. Publications

  1. Eriksson, P-O., Eriksson, A., Johansson, I., Monemi, M., and Thornell, L-E. (1994). Region dependent distribution of muscle fibre types and muscle spindles in the human masseter muscle, studied in cross-sections of whole muscle. In: Alpha and gamma motor systems (eds. Taylor, A. and Gladden, M.), Plenum press, London.
  2. Monemi, M., Eriksson, P-O., Ihari, D., Butler-Browne, G.S., and Thornell, L-E., (1996) Fetal myosin heavy chain increases in the human masseter muscle during aging. FEBS Letters 386, 87-90.
  3. Monemi, M., Eriksson, P.-O., Eriksson, A., and Thornell, L.-E. (1998) Adverse changes in fibre type composition of the human masseter muscle versus biceps brachii muscle during aging. J. Neurol. Sci. 154: 35-48.
  4. Monemi, M., Eriksson, P.-O., Kadi, F., Butler-Browne, G.S., and Thornell, L.-E. (1999a) Opposite changes in myosin heavy chain composition of human masseter and biceps brachii muscles during aging. J. Muscle Res. Cell Motil. 20: 351-61.
  5. Monemi, M., Thornell, L.-E. and Eriksson, P.-O. (1999b) Diverse changes in fibre type composition of the human lateral pterygoid and digastric muscles during aging J. Neurol. Sci. 171; 38-48.
  6. Monemi, M., Liu, J.-X., Thornell, L.-E., and Eriksson, P.-O. (1999c) Myosin heavy chain composition of the human lateral pterygoid and digastric muscle of elderly. J. Muscle Res. Cell Motil. 21; 303-12.
  7. Monemi, M., Kadi, F, Liu, J.-X., Thornell, L.-E., and Eriksson, P.-O. (1999d) Adverse changes in fibre type and myosin heavy chain compositions of human jaw muscle versus limb muscle during aging. Acta Physiol Scand ,167, 339-45.
  8. Monemi, M. (1999) Age -related changes in fibre type and myosin heavy chain compositions of human jaw muscles. Morphological, enzyme-histochemical, immuno-cytochemical and biochemical investigations. PhD Thesis.

 

B. Abstracts and presentations

  1. Monemi M, Eriksson P-O, Eriksson A and Thornell, L-E (1990) Human jaw muscle morphology in old age. Effects of ageing and of deterioration of the dentition on the enzyme-histochemical profile. Presented at Swedish odontological national meeting (Riksstämma).Stockholm.
  2. Monemi M, Eriksson P-O, Butler-Browne G and Thornell, L-E (1991) Myosin heavy chain composition of human jaw muscle in elderly. Enzyme- and immunocytochemical studies. Presented at Swedish odontological national meeting (Riksstämma). Stockholm.
  3. Monemi M, Eriksson P-O, Eriksson A and Thornell, L-E (1991) Human jaw muscle morphology in old age. Presented at Nordic odontological assembly (NOF).Helsinky, (Finland).
  4. Eriksson P-O, Johansson I, Eriksson A, Monemi M and Thornell, L-E (1993) Region dependent distribution of fibre types and muscle spindles in the human masseter, studied in cross-sections of whole muscle. Presented at The Society of Oral Physiology Conference. Gentofte, (Denmark).
  5. Monemi M, Eriksson P-O, Butler-Browne G and Thornell, L-E (1994) Myosin heavy chain (MyHC) composition of the human masseter, temporal and biceps brachii muscles in elderly. Presented at European Society of Muscle Research Congress: ” Sarcomeric myosins: structure, function and dysfunction”. Venice (Italy).
  6. Monemi M, Eriksson P-O, Butler-Browne G and Thornell, L-E (1994) Myosin heavy chain (MyHC) composition of the human jaw muscles following aging. Presented at the Faculty of Odontology, Umeå University.
  7. Monemi M, Eriksson P-O, Butler-Browne G and Thornell, L-E (1996) Adverse changes in fibre type composition in the human masseter versus biceps brachii muscle during aging. Presented at ” XXV European Society of Muscle Research Congress”. Montpellier, (France).
  8. M. Monemi, P-O Eriksson, A. Eriksson and L-E Thornell (1997) Age-related changes in fibre composition of the human masseter muscle of elderly. Presented at ”The Society of Oral Physiology, 20th Biennial Kro meeting”. Groningen. The Netherlands.
  9. Monemi M, Eriksson P-O, Butler-Browne G and Thornell, L-E (1997) Age-related changes in fibre composition of the human masseter muscle of elderly. Presented at ” Scandinavian Physiological Society”. Oslo. Norway.
  10. Monemi M, Eriksson P-O, Kadi, F, Butler-Browne G and Thornell, L-E (1998) Changes in fibre composition of the human masseter muscle following aging. Presented at Swedish odontological national meeting (Riksstämma). Stockholm
  11. Monemi M, Eriksson P-O, Kadi, F, Butler-Browne G and Thornell, L-E (1998) Muscle specific age related changes in fibre composition of the human masseter and biceps brachii muscles of elderly. Presented at the Faculty of Odontology, UmeåUniversity.
  12. Monemi M, Eriksson P-O, Kadi, F, Butler-Browne G and Thornell, L-E (1998) Age- related changes in fibre type and myosin heavy chain compositions of the human masseter versus biceps brachii muscles. Presented at the department of Integrative Medical Biology, Anatomy, Umeå University.
  13. Monemi M, Eriksson P-O, Kadi, F, Butler-Browne G and Thornell, L-E (1998) Aging alters differently the fibre type and myosin heavy chain compositions of the human lateral pterygoid and digastric muscles. Presented at ” XXVII European Society of Muscle Research Congress ”. Lund, (Sweden).
  14. Monemi M, Eriksson P-O, Kadi, F, Butler-Browne G and Thornell, L-E (1999) fibre type and myosin heavy chain compositions of the human lateral pterygoid and digastric muscles alter differently with aging. ”The Society of Oral Physiology, 21th Biennial Kro meeting”. Göteborg. Sweden.
  15. Monemi M, Eriksson P-O, Kadi, F, Butler-Browne G and Thornell, L-E (1999) Age- related changes in fibre type and myosin heavy chain compositions of human jaw muscles. Presented at the department of Odontology, Clinical Oral Physiology, Umeå University.
  16. Monemi M, Thornell, L-E and Eriksson P-O (1998) Changes in fibre composition of the human masseter muscle following aging. Presented at Swedish odontological national meeting (Riksstämma). Stockholm.
  17. Monemi M, Thornell, L-E and Eriksson P-O (2000) Human jaw closing muscles differs in phenotypic changes in fibre types during aging. Presented at Swedish odontological national meeting (Riksstämma). Stockholm.

 

1: J Muscle Res Cell Motil. 2000 May;21(4):303-12.,

Myosin heavy chain composition of the human lateral pterygoid and digastric muscles in young adults and elderly.

  • Monemi M,
  • Liu J-X,
  • Thornell LE,
  • Eriksson PO.
Department of Odontology, Umea University, Sweden. Mehrdad.Monemi@ftv.sll.se

The myosin heavy chain (MyHC) content in different parts of, two jaw opening muscle, the human lateral pterygoid and the digastric muscles of five young adult and five elderly subjects (mean age 22 and 73 years, respectively) was determined, using gel electrophoresis and immunohistochemical methods. The lateral pterygoid of both young and elderly contained predominantly slow MyHC, and fast A MyHC was the major fast isoform. In contrast, the digastric was composed of slow, fast A and fast X MyHCs in about equal proportions in both age groups. About half of the lateral pterygoid fibres contained mixtures of slow and fast MyHCs, often together with alpha-cardiac MyHC. In the digastric, co-existence of slow and fast MyHCs was rare, and alpha-cardiac MyHC was lacking. On the other hand, co-expression of fast A and fast X MyHCs was found more often in the digastric than in the lateral pterygoid. In both age groups about half of the digastric IIB fibres contained solely fast X MyHC. In the lateral pterygoid, type IIB fibres with pure fast X MyHC was found in only one subject. The lateral pterygoid in elderly showed a significant amount of fibres with solely fast A MyHC, which were occasionally found in young adults. In the digastric, no significant differences were found between young and elderly, although the muscles of elderly contained lower mean value of slow MyHC, as compared to that of young muscles. It is concluded that the lateral pterygoid and the digastric muscles differ not only in the MyHC composition but also in modifications of the MyHC phenotypes during aging, suggesting that they have separate roles in jaw opening function.

 

1: Acta Physiol Scand. 1999 Dec;167(4):339-45.,

Adverse changes in fibre type and myosin heavy chain compositions of human jaw muscle vs. limb muscle during ageing.

  • Monemi M,
  • Kadi F,
  • Liu J-X,
  • Thornell LE,
  • Eriksson PO.
Departments of Odontology, Clinical Oral Physiology, Ume inverted question marka University, Sweden.

This review shows that human jaw muscles not only have unique fibre type and myosin heavy chain (MyHC) compositions but also undergo muscle and region-specific changes in fibre composition during ageing. Alterations in the masseter and the lateral pterygoid muscles in the elderly are opposite to those reported for limb and trunk muscles, whereas changes in the anterior and posterior bellies of the digastric muscle resemble those of limb and trunk muscles. We conclude that age-related alterations in fibre type composition and MyHC expression are muscle and region specific, probably reflecting muscular differences in genetic programs and epigenetic influences.

 

1: J Neurol Sci. 1999 Dec 1;171(1):38-48.,

Diverse changes in fibre type composition of the human lateral pterygoid and digastric muscles during aging.

  • Monemi M,
  • Thornell LE,
  • Eriksson PO.
Departments of Odontology and Clinical Oral Physiology, Umea University, S-901 87, Umea, Sweden.

The fibre type composition of the superior and inferior portions of the human lateral pterygoid and the anterior and posterior bellies of the digastric muscles of five elderly subjects (mean age 73 years) was studied by morphological and enzyme-histochemical methods. Both muscles showed significant age-related changes in fibre type composition as compared with previous data for young adults. In the lateral pterygoid we observed a large proportion of type IIA fibres, which are rare or absent in young adults, and muscle fibre atrophy and an increased variability in fibre diameter. The digastric muscle of elderly showed a decrease in the proportion of type IIB fibres. The only difference in age-related changes between muscle portions was found in the lateral pterygoid with fibre atrophy in its inferior portion. Both the lateral pterygoid and digastric muscles are known to be active in mandibular depression (jaw opening) and horizontal positioning of the mandible. The present results and previous data from young adults show that the lateral pterygoid and digastric muscles differ not only in fibre type composition, but also in muscular changes following aging. This suggests that, even if they are simultaneously active, they fulfill different, specific tasks in natural jaw function. The differences in age-related changes in fibre type composition between these two muscles indicate that mechanisms underlying their alterations during aging are muscle specific. The results indicate that, although nerve supply and developmental history are essential for fibre composition of skeletal muscles, functional tasks and demands are of major importance.

 

1: J Muscle Res Cell Motil. 1999 May;20(4):351-61.,

Opposite changes in myosin heavy chain composition of human masseter and biceps brachii muscles during aging.

  • Monemi M,
  • Eriksson PO.
  • Kadi F,
  • Butler-Browne GS,
  • Thornell LE,
Department of Clinical Oral Physiology, Umea University, Sweden. mehrdad.monemi@oralphys.umu.se

The myosin heavy chain (MyHC) content in functionally different parts of the human masseter muscle of six elderly and five young adult subjects (mean age 74 and 22 years, respectively) was determined, using gel electrophoresis. The MyHC composition of the old masseter was also studied by enzyme- and immunohistochemical methods and compared with previous data for young adults. For comparison, the biceps brachii muscle of the same subjects was also analysed. The old masseter contained smaller amounts of slow and larger amounts of fast and fetal MyHCs. These differences were region-dependent and were more pronounced in the superficial portion. There was also a larger proportion of ”hybrid” fibres, containing two to four MyHC isoforms (42%), compared with the young adult masseter (23%). No such differences were observed between old and young biceps. In contrast to the masseter, the old biceps contained more slow MyHC and less fast MyHC. This investigation demonstrates that the aging process in human skeletal muscle is accompanied by a modification in the muscle phenotype which is both muscle and region specific; a transformation towards a fast and fetal phenotype concomitant with an increased number of fibres with a mixture of different MyHC isoforms in the masseter; and an opposite shift towards a slower phenotype in the biceps brachii. The results might reflect differences between jaw and limb muscles in genetic programs and adaptive responses to changed functional demands following aging.

 

J Neurol Sci. 1998 Jan 21;154(1):35-48.,

Adverse changes in fibre type composition of the human masseter versus biceps brachii muscle during aging.

  • Monemi M,
  • Eriksson PO.
  • Eriksson A.
  • Thornell LE,
Department of Clinical Oral Physiology, Umea University, Sweden. Mehrdad.Monemi@oralphys.umu.se

The fibre composition of functionally different regions, the superficial and the deep portions, of the human masseter and the biceps brachii muscles of six elderly subjects (mean age 74 years) was studied by morphological and enzyme-histochemical methods. When compared to previous data for young adults, the masseter muscle from elderly subjects showed a significant decrease in the proportion of type I fibres and an increase of type IM and II fibre types, concomitant with muscle fibre atrophy. In the old biceps, there were no changes in the type I fibre proportion and fibre diameter, but a significant decrease in the type IIB fibre content. The present results of changes in fibre composition, in addition to previous findings of functional deterioration of the old masseter, probably reflect a combination of age related degenerative and adaptive processes within the trigeminal neuromuscular system. When compared with previous findings in young adult masseter, it can be concluded that the human masseter muscle differs from limb muscles both in fibre composition and in structural response of the muscle during aging. These differences between the masseter and the biceps brachii muscle suggest muscle specific alterations during aging probably due to differences in genetical control, functional performance and nerve and hormonal influences.