W. Firbas

Arterial blood supply of the maxillary sinus.

Knowledge of the arterial supply of the maxillary sinus region is essential for surgical treatment in this area (e.g., implantation of grafting materials, repair of injuries, sinus floor elevation). The goal of this study was to describe the arterial architecture of the maxillary sinus region in respect to sinus lift procedures. In 18 unfixed human cadavers, the arterial vessels of the head were injected with a mixture of latex and bariumsulfate. Afterward, the arteries entering the maxilla were prepared. The number and calibers as well as anastomoses were carefully documented. In addition, we measured the distance between the alveolar ridge and the lower main branches.

Morphology and histochemistry of myogelosis

Myogelosis is a common diagnosis in the case of chronic pain conditions, especially in the region of the pectoral girdle musculature, the glutei muscles, and the erector spinae muscle. Although such indurative areas continue to be palpable even on the cadaver, few studies concerning the morphological substrate of these areas have been undertaken. Selected biopsies as well as larger tissue samples were taken from 11 corpses and prepared for histological study. Following staining, the frozen sections were examined morphometrically. A histologically constant, significant morphological alteration was found in the areas of concern. The spaces between the individual muscle fibers of healthy muscle tissue appear relatively wide, the endomysium of the myogelotic area are clearly narrowed. Split fibers, ragged red fibers, Type II fiber atrophy, and fibers with a moth‐eaten appearance have been detected. The morphometry shows considerable increase in thickness of the affected muscle fibers, suggestive of a pathological, local hypertrophy. The changes described may well represent a fixed condition, so that it should not be surprising that myogelosis therapy is difficult and protracted. Clin. Anat. 12:266–271, 1999.

Radiation induced alterations in rabbit aortic prostacyclin formation

Earlier studies have demonstrated very severe vascular lesions occuring after irradiation in human and experimental animals as well. We examined the rabbit aortic PGI2-formation using the platelet bioassay technique in one year aged rabbits after different irradiation doses and a time course. The findings demonstrate a significant increase in prostacyclin formation, which might be due to the damage of endothelial cells. This stage is followed by a long lasting severe depression. This behaviour in addition demonstrates a dose dependent manner, The findings of a long lasting decrease in vascular PGI2-formation might contribute to the understanding of the high incidence of vascular lesions being found at the site of irradiation.

Long-lasting depression of rabbit aortic prostacyclin formation by single-dose irradiation

Male rabbits were exposed to a single irradiation dose of 1000-5000 rad when 12, 15, 16, and 17 months old and were killed when 18 months old (i.e., 1, 2, 3, and 6 months after irradiation). Even after this long interval after irradiation, abdominal aortic prostacyclin formation was significantly depressed, whereas the nonirradiated thoracic aortic segment exhibited no significant alteration in vascular PGI2 generation. The data show that the severe decrease in PGI2 synthesis was not caused by deendothelialization induced by irradiation alone. The data support the view that a deterioration in the prostaglandin system regulating hemostatic balance is an important determinant in the development of radiation-induced vasculopathy.

Superficial branch of the radial nerve emerging between two slips of a split brachioradialis muscle tendon : a variation of possible clinical relevance

One hundred and fifty upper extremities of 75 nonrandomized human cadavers were dissected to study the topographical relationship between the brachioradialis muscle tendon (BRMT) and the superficial branch of the radial nerve (SBRN). A split BRMT was found in nine arms, while in five of those nine arms the SBRN emerged from under the brachioradialis muscle between the two slips of a divided BRMT to become superficial. This topographical relationship is mentioned sparsely in very old literature, yet its frequency has not been studied before. Further clinical investigations should be undertaken to study the clinical relevance of the above-mentioned topographical relationship.

Irradiation depresses prostacyclin generation upon stimulation with the platelet-derived growth factor

Experimental and clinical findings demonstrated rather severe arterial lesions occurring in irradiated arteries. It is suggested that a local haemostatic imbalance might be one causative factor. Liberation of PDGF causes smooth-muscle cell proliferation and PGI2 formation by the arterial wall cells, inhibiting in turn further release of PDGF from the alpha granules of the platelets. A decreased ability of irradiated vascular segments to generate PGI2 upon PDGF stimulation described here might cause haemostatic imbalance and subsequent radiation-induced lesions.

Rare variant of the brachial artery: superficial lateral inferior type VII EAB.

This study concerns a variant of the brachial artery with a modified origin and course. The artery was studied in 418 upper limbs removed from cadavers. In one upper limb the left brachial artery bifurcated into: (1) a superficial brachial a. (the variant) crossing superficially to the bicipital aponeurosis in the cubital region and assuming the course, position, and supply area of the radial artery, and (2) the deep brachial a. (another variant). An embryologic interpretation of this anomaly is based on a variant vascular development derived from the eighth intersegmental artery. The variant is termed according to Adachis classification schedule as arteria brachialis superficialis lateralis inferior Type VII with the addition EAB (epiaponeurosis bicipitalis, i.e., superficial to the bicipital aponeurosis). Accurate information concerning unusual patterns of the arteries in the upper limbs is clinically relevant, especially in the avoidance of accidental intra‐arterial injection with reflectory vascular occlusion leading to necrosis. Clin. Anat. 13:216–222, 2000.

The microvenous valvular anatomy of the human dorsal thoracic fascia.

&NA; The use of free scapular fasciocutaneous flaps for reconstruction of recalcitrant grade 6 venous stasis ulcers has shown excellent early success rates. Venous refilling times measured postoperatively over the flaps by photoplethysmography have noted improvements to normal levels. Preliminary anatomic studies have demonstrated valves in the circumflex scapular veins of flaps used in reconstruction. The purpose of this study was to investigate and document the number, morphology, size, and location of valves in the human dorsal thoracic fascia. Ten scapular flaps were obtained from unembalmed cadavers and injected with methyl methacrylate. Each flap cast was divided into four parts: proximal, right and left, and distal, right and left. We reduced the size of specimens (the largest being 24 × 11 mm) and studied them in a scanning electron microscope. We identified all valves, estimated the diameter of the corresponding vein, calculated the depth of the valvular sinus, and related it to the corresponding venous size. Light microscopy and transmission electron microscopy were used as assisting tools applied to glutaraldehyde‐fixed specimens. Analysis of injected specimens showed that valves were most abundant in veins with a luminal diameter of 30 to 120 μm (59.3 percent of 905 valves). The depth of valves became larger with increasing venous diameter. The sizes of valve sinuses were not different for individual valves. Except for veins larger than 1000 μm in diameter, there was no significant difference between the number of valves in different parts of an individual flap, nor were there significant differences between the valve numbers in different flaps. Most valves were bicuspid; only in the vein category of 30 to 120 μm were unicuspid valves encountered. Valves sometimes were located in series in a short segment of a vein; occasionally, they were found at the merging site of two veins. Transmission electron microscopy showed that valve leaflets had collagen fibers that ascended toward the tip of the leaflet and occasionally were accompanied by elastic fibers. Myofibroblasts were regularly present in the valve leaflets. These data show that fasciocutaneous flaps from the scapular region have numerous valves (90 valves on average in each flap) in the venous microcirculation. The microvenous valves in the dorsal thoracic fascia appear to be structurally similar to valves in larger veins. These valves may play a role in the improved hemodynamics and promising clinical outcome of patients with chronic venous insufficiency who have undergone free scapular flap reconstruction.

Melanocytes in the modiolus of the guinea pig cochlea

The cochleae of pigmented and albinotic guinea pigs aged 6-8 weeks were examined by electron microscopy for melanocytes in the modiolus. Two different types of melanocyte were observed: i) The first (Type A) was characterized by spherical, uniformly pigmented stage IV melanosomes. No signs of melanogenesis were seen in this perivascular pigment cell form, which is found mainly in the region of the cochlear plexus. ii) The second, very rarely observed type of melanocyte (Type B) was characterized by fusiform to oval melanosomes in various stages of maturation. Connective tissue cells containing fusiform to oval melanosomes enclosed in membrane-bound vacuoles were frequently found. These two types can be regarded as corresponding to uveal (Type A) and dermal (Type B) melanocytes. The connective tissue of the cochlear plexus seems to be derived from the leptomeninx.

Über die Verteilung der Acetylcholinesterase-Aktivität im Corti'schen Organ von Fledermäusen

Abstrakt. Es wurde die Acetylcholinesterase Aktivitat in der Cochlea von Microchiroptera nachgewiesen. Damit wurden der Verlauf und die Verteilung der efferenten Fasern dargestellt. Das Ergebnis stimmt im wesentlichen mit den histochemischen und elektronenmikroskopischen Befunden an anderen Saugetierspezies Uberein. Auffallend war die geringere Zahl efferenter Nervenendungen an den auseren Haarzellen am Beginn der Basalwindung.