Polarization and electron microscopic studies on the collagen of intact and ruptured human tendons

The intact and degenerated tendons were studied by the Picrosirius polarization microscopic method and by transmission and scanning electron microscopy. In the intact tendon, type I collagen were found as sole component. In the degenerated tendon, the collagen revealed histochemical and ultrastructural aspects with are typical of collagen type III. The formation of type III collagen must be an integral part of the disease process.

Muscle capillaries in tenotomized human muscles

The capillaries were studied in tenotonized human muscles after tenotomy or spontaneous rupture of the tendon. The mean capillary area was not significantly different in the patients with tenotomy, or with spontaneous rupture of the tendon, as compared to intact muscles. The mean basement membrane area as a percentage of total capillary area was significantly larger and the size capillary lumen significantly smaller in the injured than in the intact muscles. The alterations of the capillaries were time-dependent.

Ultrahistochemical localization of the glutamate-oxaloacetate transaminase (GOT) enzyme in hepatic and skeletal muscle cells in rat

The ultrastructural localization of the glutamate-oxaloacetate transaminase (GOT) enzyme in hepatic and skeletal muscle cells has been studied. The GOT activity localized first on the cristae of mitochondria both in hepatic and skeletal muscle cells. Further activity of the enzyme was observed in the endoplasmic reticulum and in sarcoplasmic reticulum but not in other cell components.

The lactate dehydrogenase activity and isoenzyme pattern of normal and hypokinetic human tendons

The LDH specific activity and the LDH isoenzyme pattern of eleven pairs of different normal tendons were compared with hypokinetic tendons. The LDH specific activity of hypokinetic tendons was 13--66% of the specific activity of normal tendons. The isoenzyme pattern of hypokinetic tendons altered in such a way that--with one exception--the ratio of LDH-5 and LDH-4 decreased and the ratio of LDH-1, LDH-2, and LDH-3 increased and, as a consequence, the amount of the M subunit decreased.

Hypoxic alterations of tenocytes in degenerative tendinopathy

The authors examined 34 tendons under the electron microscope, excised within 48 h after rupture of the tendons. The tendons did not exhibit any signs of inflammation or lipomatosis, but fine-structurally marked hypoxic alterations in the tenocytes could be seen. The degenerative (hypoxic tendinopathy appears in three phases, and the hypoxic lesions of the tendon occur at multiple foci or diffusely, and the various phases can exist simultaneously.

Ultrastructural changes in human liver cells due to reversible acute hypoxia

The ultrastructural alterations in human liver cells have been studied in reversible acute hypoxia. After thoracic and/or craniocerebral injury, the arterial oxygen saturation was under 60 mm Hg, and the circulation was intact, in all 20 patients. The hepatic cells were characterized by depletion of glycogen, swelling of the mitochondria with some irregularity of their membranes, and swelling of the endoplasmic reticulum, as well as by the appearance of large hypoxic vacuoles.

Calcifying tendinopathy

The authors examined 119 tendons with light-, and 34 tendons with electron microscope, excised within 48 h after spontaneous rupture of tendon. By light microscopic study 9, and by electron microscopic examination 18 cases of calcifying tendinopathy could be detected. The calcification occurred without necrosis or inflammation. The authors concluded, that calcifying tendinopathy is a hypoxic alteration of the tendon.

The effect of tourniquet ischaemia on intact, tenotomized and motor nerve injured human hand muscles

Ultrastructural examination of the intrinsic hand muscles was performed on young healthy patients undergoing reconstructive operation following tendon or nerve lesions. The muscle specimens were taken at the start and then every fifteen to twenty minutes until the end of the tourniquet ischaemia. The authors have not found any morphological alterations following the use of a tourniquet up to two hours in either the intact or previously injured muscles.

Capillary density of tenotomized skeletal muscles. II. Observations on human muscles after spontaneous rupture of tendon

Alterations in the capillary density of the M. biceps brachii was studied in 20 cases during 2 months after spontaneous rupture of the tendon. The fiber typing was done using succinic dehydrogenase and myofibrillar ATP-ase at pH 9.4 for the staining, the capillaries were visualized with alkaline phosphatase and PAS reactions, and in each case 1,000 muscle fibers with their capillaries were estimated. In the intact muscles the capillary count ranged from 1,500 to 1,910 (mean 1,740) per 1,000 fibers. During the 1st month following the rupture the decrease in the capillary count of the muscle occurred rapidly, being after 4-7, 8-10, and 18-29 days 36%, 52%, and 66%, respectively, as compared to the contralateral muscles. After 2 months a decrease of approx. 70% was found in the amount of capillaries compared with the contralateral muscles. The obliteration of the capillaries was particularly pronounced in the amount of anastomoses. These results indicate that the capillary supply of the human M. biceps brachii decreases enormously during the 1st month after a tenotomy.

Capillary density of tenotomized skeletal muscles. I. Experimental study in the rat

Our purpose was to study the capillary density of rat gastrocnemius muscle by microangiography 7-21 days after achillotenotomy or immobilization in a plaster cast. Sixteen animals were tenotomized, 12 immobilized in a plaster cast, and 4 served as controls. The number of capillaries was counted per 1,000 muscle fibres from each sample. No site differences were found in control muscles, where on an average 1,250 capillaries per 1,000 muscle fibers were found. After tenotomy the number of capillaries was decreased 35%, 31%, and 32% on days 7, 14, and 21, respectively. In immobilized muscles the decrease in capillary density occurred slowly, the corresponding decrease being 23%, 33%, and 28% on days 7, 14, and 21, respectively. These results indicate that the capillary density of muscular tissue is greatly decreased following the disuse produced by tenotomy or immobilization.

Alterations of oxygen and carbon dioxide tensions in crush-injured calf muscles of rat

The alterations of oxygen and carbon dioxide tensions in crush-injured muscles were determined by means of a Silastic-tonometer. Immediately after crush-injury the oxygen tension was elevated, then declined and 2 hours after trauma a value of 10 to 14 mmHg was reached. The oxygen tension was 8 to 15 mmHg the next four days after injury, from 5th day the tissue pO2 elevated rapidly. On 14th day the tissue oxygen tension was 60-72 mmHg, thereafter decreased gradually to 40-50 mmHg by the 19th day. The tissue pCO2 elevated within 2 hours after injury to 95-105 mmHg. From 5th day decreased gradually to 50 mmHg by the 21st day.

Oxygen and carbon dioxide tensions in calf muscles of rat

The oxygen and carbon dioxide tension were studies with Silastic tonometer technique in skeletal muscle and subcutaneous tissue of rat. The high initial pO2 was caused by airborne contamination during implantation and declined rapidly. Tissue gas tensions measured with a Silastic tonometer reflect the healing sequences of implantation trauma and stable readings are not obtained until 14 days after implantation. After healing of implantation injury 42 to 47 mmHg pO2 and 50 to 57 mmHg pCO2 were measured in muscle and 23 to 26 mmHg pO2 and 51 to 57 mmHg pCO2 in subcutaneous tissue of rat.

A new preparation technique for scanning electron microscopy of skeletal muscle

The authors describe a new preparation technique for scanning electron microscopic study of the internal structure of skeletal muscle cells. The specimens were fixed, dehydrated and imbibed with Epon or Durcupan--without polymerisation--and thereafter they were freeze-fractured.

The Ehlers-Danlos syndrome causing lacerations in tendons and muscles

A case of a 20 year old patient with an Ehlers-Danlos syndrome is described, in which a rupture of the Achilles tendon is repaired by a segmental tendon homograft. The function of the triceps surae returned to normal gradually and the plantar flexion was even weaker after 2 years. The technique and importance of the special radiography of the soft tissue is discussed with regard to the clinical diagnosis. Radiographs, histomorphologic and histologic results illustrate the course of the healing.

[Changes in the skeletal musculature due to tendon rupture]

Alterations of the sceletal muscles after spontaneous rupture of the tendon were studied. It was established that after the rupture of the tendon in the muscle activity of the succinedehydrogenase, myofibrillar ATP-ase, creatinphosphokinase and aldolase markedly decreases. After the rupture of the tendon alteration of the proportion of various types of fibers may also be observed i.e. the rate of the fibres of type I considerably decreases. Electron microscopic findings indicate that alterations of the musculature are diffuse first of all elements of contractility are damaged: atrophy and rupture of them can be seen. Fibres of normal ultrastructure were not found at all, which indicates that both types of fibres I and II are equally damaged.

Histochemical and ultrastructural study of adult human tendon

The authors have studied the enzymhistochemical and ultrastructural pictures of tenocytes of adult human tendons. High succinate dehydrogenase, cytochrome oxidase, TPN-diaphorase, lactate dehydrogenase and glucose-6-phosphate dehydrogenase activity were found, as indicated both oxidativ, anaerobic and pentose-phosphate shung activity. Phosphorylase and glutamate dehydrogenase activity was medial, lipase and alcaline phosphatase activity was slight. In tenocytes well developed rough endoplasmic reticulum and GOLGI apparatus, large amount of free ribosomes were found.