[Rotational stability in intraocular lenses with C-loop haptics versus Z haptics in cataract surgery. A prospective randomised comparison]. / Rotationsstabilität monofokaler Intraokularlinsen mit C-Haptik versus Z-Haptik nach Kataraktchirurgie. Prospektiver randomisierter Vergleich.

The aim of the study was to compare the rotational stability of intraocular lenses (IOLs) with C-loop haptics and those with Z haptics. A total of 50 patients with cataracts were prospectively randomised in equal numbers using a design equivalent to IOL MS 612 S (C-loop haptic) and MS 6120 (Z haptic, both HumanOptics, Erlangen). Complete ophthalmological examinations were performed including assessment of the IOL rotation after 1 day, 1 month and 3 months postoperatively. The significances between the groups were evaluated using the Wilcoxon test. The Fisher exact test was used for the primary finding of the study (rotation of at least 10 degrees ). The IOL group with the C-loop haptics showed a median lens rotation of 0 degrees on the first day and 2 degrees clockwise after 1 month and 3 months. In the Z haptic group, there was no median rotation in the IOL group. Moreover, the range of IOL rotation of the C-loop haptics was broader (3 months postoperatively: maximum in the C-loop haptics: 21 degrees with 15.5 degrees in the Z haptics). There was no significant difference at any time. At 3 months postoperatively, 32% of the C-loop haptic IOL and 16% of the Z haptic IOL rotated at least 10 degrees (P=0.32). In 59% of the IOL with C-loop haptics, the direction of the rotation was clockwise. This was 40% for the IOL with Z haptics (P=0.33). At 3 months postoperatively, both IOLs demonstrated good rotational stability with a low mean deviation from the target axis. IOLs with Z haptics showed a tendency to greater rotational stability than C-loop haptics but without any significant difference. There was no significant difference in visual rehabilitation.

Immunogold EM reveals a close association of plectin and the desmin cytoskeleton in human skeletal muscle.

Plectin is a multifunctional cytoskeletal linker protein with an intermediate filament-binding site and sequence elements with high homology to actin-binding domains. Mutations of the human plectin gene as well as the targeted inactivation of its murine analog cause a generalized blistering skin disorder and muscular dystrophy, thus implying its essential role in cells that are exposed to mechanical stress. In the present study we report the characterization of two new domain-specific plectin antibodies as well as ultrastructural localization of plectin in normal human skeletal muscle. Using immunogold electron microscopy, we localized plectin at three prominent sites: 1) Plectin is found at regularly spaced intervals along the cytoplasmic face of the plasma membrane. 2) It is distinctly localized at filamentous bridges between Z-lines of peripheral myofibrils and the sarcolemma and 3) at structures forming the intermyofibrillar scaffold. At the latter two locations, plectin and desmin were found to colocalize. Our ultrastructural analysis suggests that plectin may have a central role in the structural and functional organization of the intermediate filament cytoskeleton in mature human skeletal muscle.

Surplus protein myopathies.

Certain muscular dystrophies are marked by absence or reduction of mutant proteins, foremost dystrophinopathies and sarcoglycanopathies. Conversely, other sporadic and familial neuromuscular conditions are marked by a surplus of proteins present in a granular or filamentous form, such as desmin-related myopathies, actinopathy and, perhaps, hyaline body myopathy. This emerging group of congenital myopathies is clinically, immunohistochemically, and genetically diverse. Clinically, early- and late-onset diseases with variable courses are described. Immunohistochemically, mutant gene-related and other proteins have been identified by immunohistochemistry. Mutations in the desmin and alpha-B crystallin genes have been discovered in desminopathies. Mutations in the actin gene, but in no other genes have been revealed in actinopathy. Surplus sarcoplasmic and/or intranuclear nemaline bodies have been related to mutant tropomyosin-3, actin and nebulin genes. This emerging concept of surplus protein myopathies will require substantial investigation to further interpret the results of present and future studies.

Nemaline myopathy with intranuclear rods--intranuclear rod myopathy.

Among the different nosological forms of nemaline/rod myopathy, one morphological variant is marked by intranuclear rods in addition to sarcoplasmic rods. Such patients fall into two categories: firstly, adults and secondly, young infants suffering from the severe form. Intranuclear rods indicate unfavourable prognosis. Recently, intranuclear rods without sarcoplasmic rods have also been encountered. Intranuclear rods, largely solitary, are often found large in size with the ultrastructural lattice pattern of sarcoplasmic rods and Z-disks. They contain alpha-actinin and actin. The origin of intranuclear rods is still enigmatic. Their presence within nuclei without sarcoplasmic rods points to a de novo formation within the respective muscle fiber nuclei.

Congenital myopathy with excess of thin myofilaments.

Three unrelated young children are reported to have suffered since birth from muscle hypotonia and two of them from fatal respiratory insufficiency. Muscle tissues were found to contain large masses of thin myofilaments, immunologically identified as containing actin, but without further morphological features. These masses of thin filaments were found in different muscles at different occasions in the three children, suggesting a disease-specific morphological and possibly nosological feature all of them justifying classification as congenital myopathy with excess of actin or actin myopathy. The lesions were dissimilar to hyaline bodies in that the latter consist of granular material which is faintly positive for ATPase activity whereas the masses of thin filaments are devoid of ATPase activity. Two of our three patients also had intranuclear rods with virtually no sarcoplasmic rods suggesting the term of this congenital myopathy as actin myopathy with intranuclear rods.

Significance of lipopigments with fingerprint profiles in eccrine sweat gland epithelial cells.

Lipopigments with fingerprint profiles in eccrine sweat gland epithelial cells are regular findings in childhood NCL. They have also been described in adult NCL (ANCL) a few times, but not consistently. However, they have been considered nonspecific when not matched by similar abnormal profiles in noneccrine sweat gland epithelial cells. These conflicting reports may pose a diagnostic dilemma as outlined in the following 2 examples. Patient 1 is a 20-year-old man who developed severe tetraparesis and dementia over 2 years. Electroencephalogram was abnormal with epileptiform discharges. The patient died at age 21 years without autopsy; no other relatives are known to have a similar disease. Patient 2, a 49-year-old woman, developed ataxia and gait abnormalities when 44 years old, and, later, psychosis and dementia. The patient is still alive; no other family members are similarly affected. Both patient lacked evidence of a retinopathy clinically, funduscopically, and by electroretinography. Both patients showed lipopigments within secretory eccrine sweat gland epithelial cells which harbored unequivocal fingerprint profiles, but not within noneccrine sweat gland cells. Regular lipofuscin was observed in other cells, including skeletal muscle fibers of patient 2.

Filamin C accumulation is a strong but nonspecific immunohistochemical marker of core formation in muscle.

Filamin C is the muscle isoform of a group of large actin-crosslinking proteins. On the one hand, filamin C is associated with the Z-disk of the myofibrillar apparatus and binds to myotilin; on the other hand, it interacts with the sarcoglycan complex at the sarcolemma. Filamin C may be involved in reorganizing the cytoskeleton in response to signalling events and in muscle it may, in addition, fulfill structural functions at the Z-disk. An examination of biopsies from patients with multi-minicore myopathy, central core myopathy and neurogenic target fibers with core-like target formations (TF) revealed strong reactivity of all the cores and target formations with two different anti-filamin C antibodies. In all three conditions, the immunoreactivity in the cores for filamin C was considerably stronger than that for desmin. Only for alphaB-crystallin were comparable levels of immunoreactivity detected. There was no difference in intensity for filamin C between the three pathological conditions. Thus, filamin C along with alphaB-crystallin is a strong and robust, but nonspecific marker of core formation. The reason why filamin C accumulates in cores is unclear at present, but we postulate that it may be critically involved in the chain of events eventually leading to myofibrillar degeneration.

Progress in desmin-related myopathies.

Desmin-related myopathies are sporadic and familial neuromuscular conditions of considerable clinical heterogeneity uniformly marked by the pathologic accretion of desmin, often in a filamentous fashion. A large variety of other proteins, some of them cytoskeletal, also accrue. Morphologically, two types may be distinguished, one characterized by inclusions such as cytoplasmic and spheroid bodies or desmin-dystrophin plaques and another marked by granulofilamentous material. The genetic spectrum of desmin-related myopathies is quite diverse in that missense mutations and deletions in the desmin gene and a missense mutation in the alpha-B crystallin gene have been detected and several genes on other chromosomes have been mapped; the encoded protein products of these genes, however, are unknown. Accumulation of desmin and other proteins appears to be due to impaired nonlysosomal proteolysis. Mutant desmin that appears to be hyperphosphorylated seems to act as a seed protein for filament aggregation, inducing formation of inclusions and granulofilamentous material in these conditions. This condition is part of the group of disorders known as "surplus protein myopathies."

Infantile intranuclear rod myopathy.

This report concerns three unrelated floppy infants, two girls and one boy, each biopsied at the age of 1 month. They were hypotonic since birth and required artificial ventilation. The two girls died at the ages of 4 and 3 1/2 months, respectively, the boy is still alive at the age of 2 years, but requires assisted ventilation. Each of the three infants showed, by muscle biopsy, abundant intranuclear rods, the boy and one girl also had sarcoplasmic rods, which were not present in the other girl's muscle. Absence of sarcoplasmic rods, but the presence of intranuclear rods could also be documented in her autopsied muscle. Using an antibody against alpha-actinin, immunoelectron microscopy showed reaction of the sarcoplasmic and intranuclear rods demonstrating their Z-band origin. To our knowledge, this is the first report on rod myopathy with intranuclear rods only and of an immunoelectron microscopic demonstration of alpha-actinin in intranuclear rods. The presence of intranuclear rods in infants with nemaline myopathy also appears to indicate a grave prognosis of their rod myopathy.

Immunohistologic and electron microscopic abnormalities of desmin and dystrophin in familial cardiomyopathy and myopathy.

A 52-year-old man had a cardiomyopathy for 22 years as had his brother. Both required pacemakers. For the past 12 years, he also suffered from increasing muscle weakness. His muscle fibres contained granulo-filamentous material as previously seen in muscle fibres of a French family with myopathy and cardiomyopathy. It was rich in desmin, alpha-B crystallin, and dystrophin, the connotation, pathogenesis, and common denominator of which, however, remain unexplained.

Gene-related protein surplus myopathies.

Numerous muscular dystrophies, such as dystrophinopathies, sarcoglycanopathies, and emerino- and laminopathies, are marked by the absence or reduction of mutant transsarcolemmal or nuclear proteins. In addition to these recently identified minus-proteinopathies, there are a growing number of plus-proteinopathies among neuromuscular disorders marked by a surplus or excess of endogenous proteins within muscle fibers of different, i.e., nontranssarcolemmal and nonnuclear types. These proteins are often filamentous; for example, desmin and actin accrue in respective desmin-related myopathies, among which are entities marked by mutant desmin, true desminopathies, and actinopathy, the latter often seen as a subgroup in nemaline myopathies. Desmin-related myopathies consist largely of those marked by desmin-containing inclusions and those characterized by desmin-containing granulofilamentous material. When mutations in the desmin gene can be identified, the mutant desmin is thought to form the major myopathological lesion. Together with desmin, other proteins often accumulate. The spectrum of these proteins is quite diverse and encompasses such proteins as dystrophin, nestin, vimentin, alphaB-crystallin, ubiquitin, amyloid precursor protein, and beta-amyloid epitopes, as well as gelsolin and alpha(1)-antichymotrypsin. Among these associated proteins, one, alphaB-crystallin, has been found mutant in one large family, justifying the term alphaB-crystallinopathy as a separate condition among the desmin-related myopathies. Other proteins accruing with desmin have not yet been identified as mutant in desmin-related myopathies. Mutations in the desmin gene entail missense mutations and small deletions. The formation of mutant actin may lead to aggregates of actin filaments which may or may not be associated with formation of sarcoplasmic and/or intranuclear nemaline bodies. A considerable number of missense mutations in the sarcomeric actin gene ACTA1 have been discovered in patients with nemaline myopathy and also in a few patients without myopathological evidence of nemaline bodies in biopsied skeletal muscle fibres. Apart from alphaB-crystallin, no other proteins coaggregating with actin in actin filament aggregates of actinopathy or the actin mutation type of nemaline myopathy have so far been identified. Two further candidates for protein surplus myopathies are hyaline body myopathy, which is marked by accumulation of granular nonfilamentous material within muscle fibers that is rich in myosin and adenosine triphosphatase activities, and hereditary inclusion body myopathies, which are marked by accumulation of tubulofilaments similar to the helical filaments of Alzheimer neurofibrillary tangles. These tubulofilaments consist of diverse proteins as well, though no mutant protein has yet been discovered. So far, no genes responsible for familial hyaline body and hereditary inclusion body myopathies have been identified. The discovery of mutant proteins, desmin, alphaB-crystallin, and actin, as components of surplus or excess proteins accumulating in muscle fibers in certain neuromuscular conditions is responsible for the recent emergence of this new concept of gene-related protein surplus myopathies.

Acute infantile spinal muscular atrophy. Muscle apoptosis as a proposed pathogenetic mechanism.

Biopsy as well as autopsy studies of a child who died 8 weeks after birth from the acute infantile form of spinal muscular atrophy revealed classical morphological changes, including degeneration and loss of motoneurons in the spinal cord, loss of large myelinated fibres in anterior roots and neurogenic atrophy in muscle. New ultrastructural findings include massive muscle cell elimination by apoptosis with the formation of membrane-bound muscle cell fragments, apoptotic bodies. In addition, numerous immature muscle fibres were observed. The morphological findings raise the possibility that in a severely growth-retarded muscle, the process of muscle cell apoptosis removes the peripheral target of anterior horn cells resulting in secondary motoneuron death.

Neonatal centronuclear myopathy with N-CAM decorated myotubes.

Muscle specimens from two baby males with fatal X-linked recessive (XLR) form of central nuclear myopathy (CNM) were studied by immunochemistry using cell surface molecules (N-CAM) and by electron microscopy. In both neonates muscle fibres with morphology of myotubes strongly expressed N-CAM. The expression of N-CAM in non regenerating postnatal human muscle suggests that neonatal X-linked fatal form of CNM is characterized by arrest or delay of maturation of muscle fibres.

Axonal pathology of the skin in infantile neuroaxonal dystrophy.

Ultrastructural studies on the skin of two patients affected by infantile neuroaxonal dystrophy (INAD) were performed to evaluate its diagnostic value and to discuss the etiology of INAD. While the majority of terminal axons around intradermal glands were dystophic consisting of tubulomembranous and tubulovesicular profiles sometimes accompanied by synaptic vesicles, there were only few dystophic axons inside intradermal nerve bundles. These observations suggest that the primary lesion of INAD is located in terminal and presynaptic axons. Therefore, terminal axons have to be investigated when a diagnostic skin biopsy is performed in INAD.

p0071, a member of the armadillo multigene family, is a constituent of sarcomeric I-bands in human skeletal muscle.

p0071 is a member of the armadillo gene family that is expressed in a wide variety of mammalian tissues and cell types with a prominent cell-cell contact association in epithelial cells. Here, we report the expression and localization patterns of p0071 in differentiating human skeletal muscle cells and in normal and diseased human skeletal muscle tissues. Northern blots revealed expression of p0071 mRNA in adult skeletal muscle tissue. RT-PCR analysis and Western blotting experiments identified two differentially spliced isoforms of p0071. The balance between these isoforms shifted during in vitro differentiation of isolated muscle cells from predominant expression of the short variant to a preponderance of the larger variant from day 6 onwards. Immunolocalization studies in mature skeletal muscle tissue revealed that p0071 is a constituent of myofibrils with a distinct localization at the level of sarcomeric N2-lines. During myofibrillogenesis, p0071 was not detected in non-striated nascent myofibrils, but became apparent shortly after the development of compact Z-discs in early myotubes. Furthermore, we studied the expression of p0071 in a wide variety of neuromuscular disorders by indirect immunofluorescence. Here, the myofibrillar staining of p0071 was preserved in all the disease entities included in our study. Our results provide the first evidence that a member of the armadillo multigene family is a constituent of the contractile apparatus in human skeletal muscle. The localization of p0071 at the level of I-bands and the timepoint of its integration into developing myofibrils suggest a possible role in the organization of thin filaments.