Author
Björn A. Afzelius
Bio: Björn A. Afzelius is an academic researcher from Stockholm University. The author has contributed to research in topics: Axoneme & Sperm. The author has an hindex of 34, co-authored 127 publications receiving 4441 citations.
Topics: Axoneme, Sperm, Spermatozoon, Cilium, Mucociliary clearance
Papers published on a yearly basis
Papers
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TL;DR: The results support the hypothesis that a congenital defect in the cilia and sperm tails will cause chronic respiratory-tract infections and male sterility--the immotile-cilia syndrome.
Abstract: We investigated six men and a woman suspected of suffering from congenital immotility of cilia. All had chronic airway infections, and the men had immotile spermatozoa. The woman and three men had Kartagener's syndrome. The investigations included measurements of the mucociliary transport in the lower airways and ultrastructural studies of the sperm tails or respiratory cilia (or both). Mucociliary transport was significantly delayed. Sperm tails lacked dynein arms in five patients. Respiratory cilia from the women and two men lacked dynein arms and were irregularly oriented. The results support the hypothesis that a congenital defect in the cilia and sperm tails will cause chronic respiratory-tract infections and male sterility--the immotile-cilia syndrome. In about half these patients there will also be a situs inversus--i.e., Kartagener's syndrome.
571 citations
Book•
01 Jan 1999
TL;DR: Taxonomic summary and phylogenetic analysis of the fertilizing spermatozoon phylogeny of the hexapod orders superclass hexapoda class insecta (ectognathous hexapods) and the hemipteroid orders.
Abstract: Development of the insect spermatozoon - spermatogenesis the fertilizing spermatozoon phylogeny of the hexapod orders superclass hexapoda class insecta (ectognathous hexapods) subclass apterygota subclass pterygota (introduction) infraclass palaeopter infraclass neoptera orthoptera and phasmatodea orders embioptera, dermapter, plecoptera and grylloblattodea the hemipteroid (rhynchotoid) orders the hemipteroid orders - hemiptera suborder heteroptera the endopterygota (holometabola) order coleoptera orders mecoptera and siphonaptera orders diptera and strepsiptera superorder amphiesmenoptera order hymenoptera taxonomic summary and phylogenetic analysis.
250 citations
TL;DR: Mitochondrial fibers with DNA-characteristics are described from a large number of cell types, representing different tissues taken from animals of eight phyla, showing that the DNA is an integral part of most and probably all mitochondria, although the fibers in some cases are difficult to visualize.
205 citations
TL;DR: It is concluded that spermatids can effect specification of different protofilament numbers with numerical exactitude for the different types of microtubules.
161 citations
TL;DR: 14 cases of sperm tails from men who have spermatozoa that are immotile but living are described, which belong to five distinct groups and three men from this fifth category did not suffer from the immotiles-cilia syndrome.
134 citations
Cited by
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TL;DR: The development of brown adipose tissue with its characteristic protein, uncoupling protein-1 (UCP1), was probably determinative for the evolutionary success of mammals, as its thermogenesis enhances neonatal survival and allows for active life even in cold surroundings.
Abstract: Cannon, Barbara, and Jan Nedergaard. Brown Adipose Tissue: Function and Physiological Significance. Physiol Rev 84: 277–359, 2004; 10.1152/physrev.00015.2003.—The function of brown adipose tissue i...
5,470 citations
TL;DR: The hypothesis is that slowed growth within certain zones of the left hemisphere is likely to result in enlargement of other cortical regions, in particular, the homologous contralateral area, but also adjacent unfaffected regions.
Abstract: Part two of this three-part series commences with anomalous dominance and special talents. Part one appears in a previous issue of theArchives. 1 ANOMALOUS DOMINANCE AND SPECIAL TALENTS According to our hypothesis, slowed growth within certain zones of the left hemisphere is likely to result in enlargement of other cortical regions, in particular, the homologous contralateral area, but also adjacent unfaffected regions. The influences that favor anomalous dominance may thus favor talents associated with superior development of certain regions either in the right hemisphere or in adjacent parts of the left hemisphere. Even with excessive retardation of growth and the resultant migration abnormalities and learning disorders (LD), high talents may exist as a result of compensatory enlargement of other cortical regions. Several types of data are in concordance with these conclusions. Several studies have claimed that the average level of spatial talents is higher in male subiects. 2 Hier
1,888 citations
TL;DR: The data suggest that KIF3B is essential for the left-right determination through intraciliary transportation of materials for ciliogenesis of motile primary cilia that could produce a gradient of putative morphogen along the left–right axis in the node.
1,418 citations
TL;DR: These transcriptional paradigms provide a basic framework for understanding the integration of mitochondrial biogenesis and function with signaling events that dictate cell- and tissue-specific energetic properties.
Abstract: Mitochondria contain their own genetic system and undergo a unique mode of cytoplasmic inheritance. Each organelle has multiple copies of a covalently closed circular DNA genome (mtDNA). The entire...
1,401 citations
TL;DR: It is reported here that chronic treatment with the peroxisome proliferator-activated receptor γ agonist rosiglitazone promotes not only the expression of PGC-1α and mitochondriogenesis in these cells but also a norepinephrine-augmentable UCP1 gene expression in a significant subset of the cells, providing these cells with a genuine thermogenic capacity.
1,225 citations