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Biomedical subjects

Z Halata

Publications and source records attributed to Z Halata.

At least 55 records · Page 3Linked to original sources
PubMed1990

Age-related osteo-arthrotic degeneration of the temporomandibular joint in the mouse.

The light-microscopic and ultrastructural characteristics of the temporomandibular joints (TMJs) of female STR/IN mice, aged from 3 to 12 months, were studied. Every TMJ of an adult mouse starts to degenerate in early adulthood and subsequently suffers from osteo-arthrosis. Ageing of the TMJ is characterized by thinning out of its cartilaginous components. The chondrocytes are no longer distributed regularly in the ground substance but form clusters. Cracks and fissures invade the condylar cartilage and lead to the formation of cartilage islands, which finally become loose as free bodies in the lower joint chamber and joint capsule. The lower joint chamber diminishes, but no ankylosis is observed. Ultrastructurally, the number of vesicles around the degenerated chondrocytes increases. Aged chondrocytes contain more lysosomes. The condylar surface becomes irregular and reveals microscars. Its surface is covered by an electron-dense fine granular material, considered to be built up by proteoglycans. Compared to the male ICR mouse, the osteo-arthrotic destruction of the cartilage, the subchondral sclerosis and the deformation of the underlying bone exhibit only minor states in the female STR/IN mouse. Concerning the aetiology and pathogenesis, the very early degeneration of the mostly unloaded TMJ seems to be based on a genetically altered composition of the articular cartilage, possibly due to failing articular chondrocyte responses to stimuli connected with degeneration and repair.

Aging↗
PubMed1990

Sensory innervation of the temporomandibular joint in the mouse.

The sensory innervation of the temporomandibular joints (TMJs) of 8 STR/IN mice was investigated by means of light and electron microscopy. Through the cutting of complete semithin sections in series it was possible to investigate the joints thoroughly. Additionally, one joint with its nerve supply was reconstructed three-dimensionally with a computerized three-dimensional programme. The reconstruction was based on one complete semithin section series. The joint's nerve supply originates from the nervus auriculotemporalis and additionally from motor branches of the n. mandibularis: n. massetericus, n. pterygoideus lateralis and the nn. temporales posteriores. The greatest number of nerve fibres and endings is located in the dorsolateral part of the joint capsule. They lie only in the stratum fibrosum and subsynovially. Neither the stratum synoviale nor the discus articularis contain any nerve fibres or endings, whereas the peri-articular loose connective tissue is richly innervated. The only type of nerve ending observed within the joint was the free nerve ending, which is assumed to serve not only as a nociceptor but also as a polymodal mechanoreceptor. Merely within the insertion of the musculus pterygoideus lateralis at the collum mandibulae single stretch receptors of the Ruffini type were observed. Ultrastructurally, they correspond to those described in the cat's knee joint. Neither lamellated nor nerve endings of the Golgi or Pacini type were observed in the joint or in the peri-articular connective tissue. The unexpected paucity of nerve fibres and endings in the TMJ itself of the mouse suggests that the afferent information from the joint is less important for position sense and movement than the afferent information from muscles, tendons and periodontal ligaments.

Animals↗
PubMed1990

Cholinesterase activity in sensory-nerve endings, capillaries and motor end plates of the facial skin of the brush-tailed possum (Trichosurus vulpecula).

The facial skin of two adult and one 50-day-old pouch animal of the marsupial mammal Trichosurus vulpecula was removed after the animals has been suitably anesthetized and perfused for electron microscopy. Small blocks of tissue (1 x 0.5 mm) were cut and incubated in acetylthiocholine iodide substrate for cholinesterase studies. The blocks were then subsequently postfixed in osmium tetroxide. Thin sections were cut and stained with lead acetate. Specific cholinesterase was found within the nerves of both the adult and the 50-day-old pouch animal, and in the motor end plates. Nonspecific cholinesterase was present in pinocytotic vesicles and interlamellar spaces of terminal Schwann cells associated with nerve end organs in the adult, and in the same areas in Schwann cells of nonmyelinated nerves in the pouch animal. It was also present in the pinocytotic vesicles of the capillary endothelium.

Animals↗
PubMed1990

[The coxal end of the femur. An architecture following strict rules].

In order to combine the dynamic hip screw with a plate that anchors the greater trochanter, detailed measurements of the greater trochanter are necessary and its relation to the femoral head and neck must be studied. The hips in 200 X-ray films in the AP view were measured. The radiographs were obtained from 46 males and 87 females (69.2 +/- 16.9 years old) without hip disease. Concerning the neck shaft angle, no selection was done. The axis of the femoral head and neck was drawn; a second horizontal line passed through the apex of the lesser trochanter. Both lines intersected the lateral cortex of the femur. The distance between those two intersections was measured: d = 0.41 +/- 0.28 cm. In the next step, 74 human femora were obtained from 21 females and 17 males (79.9 +/- 9.0 years old). A special gauge was fixed at the lateral site of the femur. Using this gauge, the size and shape of the greater trochanter were measured: (1) the apex of the greater trochanter lay exactly on the line, which was determined by the lateral cortex of the femoral shaft (+/- 0.4 cm); (2) the maximum lateral extension of the greater trochanter was measured half-way from the lesser trochanter niveau to the apex of the greater trochanter (minor-major distance: 6.09 +/- 0.82 cm; minor-lateral maximum distance: 3.03 +/- 0.59 cm); (3) the maximum lateral extension of the greater trochanter measured 11.4 +/- 3 mm.

Aged↗
PubMed1989

The ultrastructure of sensory nerve endings in human anterior cruciate ligament.

The sensory innervation of the anterior cruciate ligament (ligamentum cruciatum anterius) of the human knee joint was studied by light- and electron microscopy. The connective tissue between the synovial membrane and the cruciate ligament contains small Ruffini corpuscles and lamellar corpuscles with several inner cores. The connective tissue septa between the individual fascicles of the cruciate ligament contain Ruffini corpuscles and free nerve endings. The free nerve endings are innervated by C-fibres and myelinated A-delta fibres. The afferent axons of Ruffini corpuscles are myelinated and measure 4-6 microns in diameter, those of the lamellar corpuscles with several inner cores measure about 6 microns in diameter. It is discussed, whether these receptors of the anterior cruciate ligament may influence the muscle tone via polysynaptic reflexes.

Adolescent↗
PubMed1989

The structure of physiologically located periodontal ligament mechanoreceptors of the cat canine tooth.

A correlative morphological study was carried out on physiologically located periodontal mechanoreceptors in anaesthetised cats. Three periodontal mechanoreceptors were electrophysiologically identified from functionally single fibres teased from the inferior alveolar nerve. One receptor was studied by recording in the mesencephalic nucleus. The four receptors were located by punctate stimuli in the labial aspect of the periodontal ligament of the left mandibular canine tooth in three cats. The receptors were within the intermediate to rapidly adapting part of the range of adaptation rates with conduction velocities of 39.6 ms-1 +/- 4.7 ms-1 and were typical of those recorded in previous studies. The receptor loci were marked and these regions were studied in silver-stained sections and ultrastructurally. Under each ink-marked region Ruffini terminals and smaller terminals resembling free nerve endings were observed. The Ruffini terminals were unencapsulated and the majority had diameters of 2-3 microns. The terminals were observed near the junction of the inner (cemental) and middle zones of the periodontal ligament with the axons running from the alveolar aspect. The results support the view that periodontal mechanoreceptors, even those with more rapidly adapting properties, are Ruffini terminals.

Action Potentials↗
PubMed1987

Topography and ultrastructure of sensory nerve endings in the joint capsules of the Kowari (Dasyuroides byrnei), an Australian marsupial.

The present investigation in concerned with the topography and ultrastructure of sensory nerve endings in the joint capsules of the Kowari (Dasyuroides byrnei), an Australian marsupial. Material for light and electron microscopy was obtained from shoulder, elbow and knee joint capsules. On the basis of differences in the organization of the connective tissue belonging to the fibrous layer, 3 variants of capsule structure have been distinguished: a rigid, a flaccid and an intermediate type. Whilst the rigid type is characterized by dense connective tissue in the clearly demarcated fibrous layer, the flaccid type shows loose, irregularly arranged connective tissue in the fibrous layer which merges into the synovial layer of the joint capsule. The morphology of the intermediate type corresponds to an intermediate stage between the former two types. In the fibrous layer of the joint capsules three different types of sensory nerve endings were observed: free nerve endings, Ruffini corpuscles and lamellated corpuscles. The free nerve endings are supplied by myelinated afferent axons (1-2 microns in diameter); the terminal thickenings of which are incompletely surrounded by a terminal Schwann cell. Ruffini corpuscles are present in three different varieties: small corpuscles without a perineural capsule predominantly within the flaccid part of the capsule; slightly larger corpuscles with an incomplete perineural capsule and large corpuscles resembling Golgi tendon organs which predominantly occur in the rigid parts of the capsule. The afferent myelinated axons measure 2-4 microns in diameter. The lamellated corpuscles show two variants: small corpuscles with a 2 to 4-layered perineural capsule in the rigid parts of the joint capsules and large corpuscles with two longitudinal clefts of the inner core in the flaccid parts. Both types are supplied by myelinated axons of 3-5 microns in diameter. Thus, in the fibrous layer of the rigid type of joint capsules large Ruffini and small lamellated corpuscles predominate, whereas the fibrous layer of the flaccid type coincides with small Ruffini and large lamellated corpuscles. The present data, therefore, corroborate the concept that the morphology of mechanoreceptors depends upon the texture of the surrounding connective tissue.

Animals↗
PubMed1986

The neuroanatomical basis for the protopathic sensibility of the human glans penis.

The human glans penis is covered by stratified squamous epithelium and a dense layer of connective tissue equivalent to the dermis of typical skin. Rete ridges of the epidermis are irregular and vary in height depending on location, age, and presence or absence of a foreskin. The papillary layer of the dermis blends into and is continuous with the dense connective tissue forming the tunica albuginea of the corpus spongiosum of the glans penis. The most numerous nerve terminals are free nerve endings (FNEs) present in almost every dermal papilla, as well as scattered throughout the deeper dermis. FNEs are characterized by an incomplete Schwann cell investment, and contain irregularly scattered neurofilaments and neurotubules, clusters of mitochondria, vesicles of variable size and various inclusions. The ratio of FNEs to corpuscular receptors is approximately 10:1 and a similar ratio of small to large axons is seen in dermal nerves. Genital end bulbs are present throughout the glans, but are most numerous in the corona and near the frenulum. The unique corpuscular receptor of the glans penis consists of axon terminals that at an ultrastructural level resemble a tangled skein of FNEs. Simple, Pacinian and Ruffini corpuscles were occasionally identified predominantly in the corona glandis. Epidermal Merkel nerve endings and other types of mechanoreceptors typically found in primate glabrous skin (lip or digit) are not present. Rarely, dermal Merkel cells have been identified associated with genital end bulbs. The abundance of FNEs in isolated as well as corpuscular form can be correlated with the embryogenesis and known neurophysiologic and psychophysical parameters of sensory function of the glans penis. Finally, the divergence in reported values for the threshold of tactile and painful stimuli when applied to glabrous skin of fingertip and glans penis can be considered as an example of dissociated sensibility. The anatomical basis for this dissociation is the abundance of FNEs and absence of Merkel terminals and typical Meissner corpuscles in the covering of the glans, and the converse in glabrous skin of the digit.

Adolescent↗
PubMed1986

The sensory innervation of the rat rhinarium.

The present study documents the characteristics of innervation of the rhinarium or hairless rat snout skin by light and electron microscopy. The outer glabrous surface is covered with a stratified squamous epithelium that forms both rete pegs and rete ridges, the latter on the inferior border near the philtrum. The glabrous skin contains numerous presumptive epidermal and dermal free nerve endings (FNE's), Merkel terminals at the base of the rete ridges and pegs, and simple, nonencapsulated corpuscles. A second region of dense innervation, found on an elevation of the inner wall of the vestibule, contains similar components of innervation, with the exception that no Merkel terminals were identified. Since no Merkel terminals were present in this area of the vestibule, intraepidermal as well as dermal FNE's could be identified with certainty. This skin is covered by a thin squamous epithelium overlying dense connective tissue. The simple corpuscles are similar to those in the rhinarium, as well as resembling those described in other species. FNE's were frequently observed intimately associated with simple corpuscles. Several examples of large FNE's with two to three layers of cytoplasmic lamellae were found, suggestive of transitional forms between FNE's and simple corpuscles. Thus, the pattern of sensory innervation in the glabrous rat snout skin is similar to that found in other furred species described to date, but in addition, the sensory innervation of ridged skin in the rat also resembles that of epidermis organized into rete pegs. This dense sensory innervation may be correlated with whisking behavior of the predominantly nocturnal rat.

Animals↗
PubMed1985

The terminal myelin segments of afferent axons to cutaneous mechanoreceptors.

The present study documents reductions in thickness of the myelin sheath without change in axonal diameter in a series of fortuitous longitudinal sections of axons innervating mechanoreceptors. These findings are interpreted to mean that we must indicate that caution should be expressed in the evaluation of quantitative data on myelinated axons in close proximity to their termination as sensory receptors.

Animals↗
PubMed1985

The ultrastructure of sensory nerve endings in the human knee joint capsule.

The ultrastructure of sensory nerve endings in the human knee joint capsule was studied. Three types of nerve endings were found: free nerve endings (FNE), Ruffini corpuscles and Pacini corpuscles. In the joint capsule, FNE are located below the synovial layer and within the fibrous layer near blood vessels. These nerve terminals derive from myelinated A delta-fibres or from unmyelinated C-fibres. Their structure is almost identical to FNE in human hairy and non-hairy skin. Ruffini corpuscles are present within the fibrous layer and the ligaments of the capsule in three variations: small Ruffini corpuscles without a capsule, small with a connective tissue capsule, and large Ruffini corpuscles with an incomplete perineural capsule. Their afferent axons are myelinated and measure 3-5 micron in diameter. Inside the corpuscle, nerve terminals are anchored in the connective tissue belonging to the fibrous layer or to the ligaments respectively. The presence of an incomplete perineural capsule depends on the structure of the surrounding connective tissue. In ligaments with collagenous fibrils oriented in a parallel fashion, the perineural capsule is well-developed and the Ruffini corpuscle resembles a Golgi tendon organ; in areas where the fibrils show no predominant orientation, Ruffini corpuscles lack a capsule. Small Pacini corpuscles are situated within the fibrous layer near the capsular insertion at the meniscus articularis or at the periost. They consist of one or several inner cores and a perineural capsule of 1-2 layers. Larger Pacini corpuscles with one or several inner cores and a perineural capsule consisting of 20-30 layers are found on the outer surface of the fibrous layer. The ultrastructure of these nerve endings is compared with the ultrastructure of articular receptors of various animals and with the ultrastructure of sensory nerve endings in the skin of several mammalian species including man.

Adult↗
PubMed1985

The sensory innervation of the nasal glabrous skin in the short-nosed bandicoot (Isoodon macrourus) and the opossum (Didelphis virginiana).

The glabrous skin at the anterior end of the snout of the short-nosed bandicoot and the American opossum was investigated by electron microscopy. In both species of animals, this region was lined by skin with broad epidermal pegs, innervated by three types of intraepidermal nerves. These were intraepidermal nerves which penetrated the epidermis up to the level of the stratum spinosum or the stratum granulosum, intraepidermal nerves in the basal layer of the epidermis partially surrounded by Schwann cell lamellae and intraepidermal nerves associated with Merkel cells. There were two types of free nerve endings in the dermis. The first type was derived from the deep dermal nerve plexus and had the typical characteristics of nerve terminals such as mitochondria, vesicles, irregularly arranged neurotubules and neurofilaments, and glycogen granules. There was a one-to-one relationship between Schwann cell lamellae and these nerve terminals. The second type of nerve ending was brush-like and the ends of the 'brushes' were enclosed in groups by a single Schwann cell lamella. Encapsulated nerve endings in the two types of animals differed in their structure. In the bandicoot, they consisted of a nerve terminal which had one to three branches. These terminals were rounded in profile and were surrounded by Schwann cell lamellae in a stack-like arrangement. An unusual finding was that the terminal sometimes left the corpuscle and made contact with the basal lamina of the epidermis before passing into its basal layer. These corpuscles did not have a perineural capsule. In the opossum, however, simple corpuscles with inner cores completely surrounded by a perineural capsule were seen. The glabrous skin of both types of animals was innervated with Eimer's organs consisting of intraepidermal nerves, Merkel cell nerve endings and encapsulated end-organs, as well as two types of dermal nerve endings.

Animals↗
PubMed1984

The sensorineural apparatus of the human eyelid.

The present study describes a complex array of sensory nerve terminals in the human eyelid. In many respects this pattern of innervation resembles that previously described in the rhesus monkey, but in other respects it is unique to man. The most prominent nerve terminals are a complex array of lanceolate and circular Ruffini and free nerve endings that envelop the eyelashes. In addition, Merkel cells have not been conclusively identified to date in other nonhuman primate nonsinus hairs. The external root sheath collar contains Merkel cells, and dermal Merkel cells have also been identified close to the collar. The anterior cutaneous surface of the eyelid contains small vellus hairs with typical lanceolate, Ruffini, and free nerve endings resembling those of primate facial skin. Scattered Meissner and scant simple corpuscles as well as scattered free nerve endings (FNEs) can be identified on the occlusal surface of the eyelid. Intraepithelial as well as dermal FNEs were most easily identified in this region in areas lacking other corpuscular receptors. Corpuscular receptors are especially common at the occlusal/conjunctival angle. The inner or conjunctival surface of the eyelid appears to be a glandular epithelium, whereas in the rhesus monkey it is stratified squamous epithelium. This epithelium needs additional study. In summary, the present study confirms the unique sensory neural status of the human eyelid and verifies the presence of Ruffini nerve terminals by light and electron microscopy and of free nerve ending terminals at least by light microscopy, as well as a unique pattern of innervation of the human eyelash.

Adolescent↗
PubMed1984

Ultrastructure of sensory nerve endings in monkey (Macaca fascicularis) knee joint capsule.

Ultrastructural studies of sensory endings in monkey posterior medial knee joint capsule were undertaken. Three distinct sensory nerve endings have been identified: free nerve endings, Ruffini corpuscles, and Pacinian corpuscles. The free nerve endings are present in all layers of the joint capsule excluding the synovium. Two types of Ruffini corpuscles have been found in the fibrous layer. The first type is characterized by a thin perineurial capsule, the second type by a thicker perineurial capsule and extensive intra-capsular space. Both types of Ruffini corpuscles are innervated by approximately one to four myelinated axons which lose their sheaths as they course through the corpuscle. They terminate on collagen fiber bundles as distinct swellings with spiny membrane projections that are covered by a thin basal lamina. These terminals contain abundant mitochondria, agranular vesicles, and irregularly arranged neurofilaments and neurotubules. Two types of Pacinian corpuscles were occasionally observed. The first was a small, typically laminated structure with an inner core at the layer between the synovium and the fibrous layer and between the fibrous layer and muscle/ligament; larger Vater-Pacinian corpuscles were noted only at the boundary between the fibrous layer and the muscle/ligament layer.

Animals↗
PubMed1981

Identification of the Ruffini corpuscle in human hairy skin.

A Ruffini corpuscle was identified in the dense reticular dermis of the human scalp from a patient with alopecia areata. The corpuscle measured approximately 50 micrometer in diameter. One afferent myelinated axon with a diameter of 4-6 micrometer supplies the corpuscle. Branched axon terminals and the associated Schwann cells tightly envelop parallel bundles of collagen fibrils. Axon terminals evidenced focal swellings, and small finger-like protrusions projected into the endoneural connective tissue. The terminals are characterized by the presence of abundant mitochondria, numerous vesicles, particles of glycogen and electron-opaque lipid material. A thin perineural capsule envelops the bundles of collagen fibrils and associated terminals. The present study provides the first electron-microscopic characterization of a Ruffini corpuscle in human hairy skin.

Adult↗