Antizyme, a mediator of ubiquitin-independent proteasomal degradation and its inhibitor localize to centrosomes and modulate centriole amplification.

The potential tumor suppressor antizyme and its endogenous inhibitor (antizyme inhibitor, AZI) have been implicated in the ubiquitin-independent proteasomal degradation of proteins involved in cell proliferation as well as in the regulation of polyamine levels. We show here that both antizyme and AZI concentrate at centrosomes and that antizyme preferentially associates with the maternal centriole. Interestingly, alterations in the levels of these proteins have opposing effects on centrosomes. Depletion of antizyme in various cell lines and primary cells leads to centrosome overduplication, whereas overexpression of antizyme reduces numerical centrosome abnormalities. Conversely, silencing of the antizyme inhibitor, AZI, results in a decrease of numerical centrosome abnormalities, whereas overexpression of AZI leads to centrosome overduplication. We further show that the numerical centrosome abnormalities are due to daughter centriole amplification. In summary, our results demonstrate that alterations in the antizyme/AZI balance cause numerical centrosomal defects and suggest a role for ubiquitin-independent proteasomal degradation in centrosome duplication.

Antizyme inhibitor: mysterious modulator of cell proliferation.

In contrast to the considerable interest in the oncogene ornithine decarboxylase (ODC) and in the family of antizymes with regard to cell proliferation and tumorigenesis, the endogenous antizyme inhibitor (AZI) has been less well studied. AZI is highly homologous to the enzyme ODC but does not possess any decarboxylase activity. Elevated ODC activity is associated with most forms of human malignancies. Antizymes bind ODC, inhibit ODC activity and promote the ubiquitin-independent degradation of ODC. Consequently they are proposed as tumor suppressors. In particular, the most studied member of the antizyme family, antizyme 1, has been demonstrated to play a role in tumor suppression. AZI inactivates all members of the antizyme family, reactivates ODC and prevents the proteolytic degradation of ODC, which may suggest a role for AZI in tumor progression.

PAS-positive loops and networks as a prognostic indicator in cutaneous malignant melanoma.

Recently, microvascular channels, as detected by PAS histochemistry, were positively correlated with poor prognosis in uveal malignant melanoma. Since uveal melanomas are not penetrated by lymphatic vessels, while cutaneous melanomas are, the question arises as to whether these loops and networks are also of prognostic relevance in cutaneous melanoma. Histochemically and immunohistochemically detected loops and networks in 100 cases of cutaneous malignant melanoma were correlated with the occurrence of metastasis in a 10-year follow-up study. To detect these patterns, the significance of various methods (PAS reaction with/without nuclear counterstain, anti-laminin immunohistochemistry) was investigated. The presence of loops and networks was a highly significant prognostic marker (p<0.0001) for metastasis in cutaneous malignant melanoma. The presence of these patterns proved to have higher prognostic relevance for metastasis than Breslow's tumour thickness, especially for stage IB and stage IIA tumours (intermediate thickness/risk). PAS reaction without nuclear counterstain proved to be the best method to detect these patterns. Compared with the conventional staging of Breslow's tumour thickness, and especially so for stage IB and IIA melanomas, the determination of PAS-positive loops and networks in cutaneous malignant melanoma provides additional prognostic information.

Identification and characterization of potential new therapeutic targets in inflammatory and autoimmune diseases.

The isoxazole derivative Leflunomide (HWA 486) is a novel immunoregulatory and anti-inflammatory drug. Affinity chromatography was used to purify and identify Leflunomide binding proteins, which might play a role as potential cellular targets in the molecular mode of action. The Leflunomide derivative A 0273 was covalently coupled to a Fractogel(R) matrix. This column was used to separate a cytosolic protein extract of the macrophage cell line RAW 264.7 by several selected and specific gradient elution steps. Proteins that were specifically eluted through the active metabolite of Leflunomide, A 1726, were identified by subsequent protein sequence analysis. This allowed us to specify 10 cytosolic proteins, which bind with high affinity to this matrix. Three of them, glyceraldehyde 3-phosphate dehydrogenase, pyruvate kinase and phosphoglycerate mutase belong to the second part of the glycolytic pathway. The binding specificity of these protein/drug interactions was further evaluated using BIAcore(R) analysis. Kd values of glyceraldehyde 3-phosphate dehydrogenase, pyruvate kinase and lactic dehydrogenase were similar to the Kd value of a known Leflunomide target protein, dihydroorotate dehydrogenase. In order to elucidate the features as well as the overall relevance of these results, cytosolic fractions of three additional cell lines MOLT-4, A20.2J, HeLa were compared using the same chromatographic protocol. The elution profiles as well as subsequent Western blot analyses confirmed the data obtained previously for the macrophage cell line RAW 264.7.

Epidermal growth factor, vascular endothelial growth factor and progesterone promote placental development in rat whole-embryo culture.

The development and survival of rat embryos in whole-embryo culture is limited by the lack of any maternal blood circulation in a purely fetal placenta. If the resulting placental insufficiency could be overcome for some time by an increase of the placental exchange area, a prolonged culture period would result and facilitate the development of embryos. In the present study, several attempts to stimulate proliferation and growth of the fetal placenta were made by the addition of vascular endothelial growth factor (VEGF), epidermal growth factor (EGF) and progesterone to the culture medium. Rat embryos were routinely explanted with their embryonic membranes at 10.5 days of gestation. Decidua, parietal yolk sac, Reichert's membrane and the layer of superficial trophoblastic giant cells were removed. The explants were cultured and gassed continuously for 24 h in rotating plastic tubes containing rat serum, diluted to 50% with modified COON's F12 medium. Either of the two growth factors or progesterone were added to each culture tube and a control group was cultured without any factor. After the addition of each of these factors the stimulatory effect on placental growth was assessed by morphometric evaluation of several placental parameters from semithin cross-sections: On adding each of the factors the whole cross-sectional area of the placenta significantly increased, as did the area of the fetal placental mesenchyme. VEGF also increased the area of the trophoblast, and the area of the blood vessels enclosed within the trophoblast, by an average of 9.4% and 23.6%, respectively. Thus, VEGF treatment resulted in a measurable extension of the exchange area of the fetal placenta.

Glioma cell adhesion and migration on human brain sections.

Within the brain, dissemination of glioma cells follows myelinated fiber tracts and extracellular matrix containing structures such as the basement membranes of blood vessels. These patterns represent the two major routes of invasion frequently observed in clinical disease. Previously, we have characterized the substrates for preferential glioma adhesion and migration on purified ECM protein. In this study sections of human brain from different anatomical regions were used as adhesive substrates and also characterized for the presence and distribution of matrix proteins. Adhesion of marker gene transfected glioma cell suspensions to different regions and anatomical structures of human brain was quantified using a computer assisted image analysis system. Monoclonal antibodies against different adhesion molecules were used to inhibit glioma cell attachment ot specific anatomical structures. In addition, glioma cell aggregates were allowed to adhere to brain sections and single cells were observed to migrate out of these aggregates. Scanning electron microscopy was used to morphologically study the preferred routes of glioma dissemination on brain sections. In brain sections different kinetics of cell adhesion to distinct structures were observed. Within 15 minutes cells adhered and spread on blood vessels and arachnoid tissue containing sections. Choroid plexus and the ventricular wall were also adhesive structures. Adhesion to cortex required 1 hour, while adhesion and spreading on myelinated fiber tracts was retarded and required several hours of incubation. The predominant matrix proteins in small vessels were found to be laminin, collagen type IV, and fibronectin. Choroid plexus and the ependyma showed a similar composition of matrix proteins. Arachnoid fibers contained different types of collagens, predominately type I and III, whereas the only matrix protein identified in the subependyma was fibronectin. Antibodies to the alpha 2, alpha 3, and beta 1 integrin subunits completely blocked adhesion to arachnoid tissue, anti-NCAM inhibited attachment to cortex. Adhesion to blood vessels in brain sections could only be inhibited to 50% by anti-integrin beta 1. Antibodies to the av containing integrin av beta 3 also blocked 50% of adhesion to vessels. Our findings indicate that adhesion of glioma cells to brain sections most rapidly takes place on ECM protein containing regions, especially blood vessels which may serve as guiding structures for glioma dissemination.

A fifth pharyngeal arch artery does not exist in rat.

The development of the caudal pharyngeal arch arteries was studied in perfused rat embryos in the interval of embryonic day 12 1/2 to embryonic day 13 3/4 using semithin serial sections and computer-aided 3-dimensional reconstructions. The fourth pharyngeal arch artery was already developed at embryonic day 12 1/2. The sixth developed from cystic enlarged vascular sprouts at embryonic day 13 1/4. A real fifth pharyngeal arch artery was not found between the fourth and sixth artery. Instead a vascular plexus was present at embryonic day 12 1/2 which was interposed between the epithelial sheets of the fourth pharyngeal pouch and the lower cervical sinus. At the onset of development this plexus arose ventrally and dorsally from the fourth pharyngeal arch artery only. Subsequent to the development of the sixth pharyngeal arch artery, vascular branches arose ventrally and dorsally from this artery, too. The plexus underwent incipient involution from embryonic day 13 1/4. It arose either from the fourth or the sixth pharyngeal arch artery only from embryonic day 13 3/4. It drained to the venous system. Branches of the plexus which ran towards the epithelial sheet of the lower cervical sinus became prominent.

Molecular Analysis and Heterologous Expression of an Inducible Cytochrome P-450 Protein from Periwinkle (Catharanthus roseus L.).

We screened cDNA libraries from periwinkle (Catharanthus roseus) cell cultures induced for indole alkaloid synthesis and selected clones for induced cytochrome P-450 (P-450) proteins by differential hybridization, size of the hybridizing mRNA, and presence of amino acid motifs conserved in many P-450 families. Four cDNAs satisfying these criteria were analyzed in detail. They were grouped in two classes (pCros1, pCros2) that represented two closely related genes of a new P-450 family designated CYP72. Antiserum against a cDNA fusion protein overexpressed in Escherichia coli recognized in C. roseus a protein band of 56 kD. Quantification of western blots showed that it represented 1.5 +/- 0.5 and 6 +/- 1 mug/mg of protein in the membranes from noninduced and induced cells, respectively, and analysis of the total P-450 content suggested that the cDNA-encoded protein was one of the dominant P-450 proteins. The pathway to indole alkaloids contains two known P-450 enzymes, geraniol-10-hydroxylase (GE10H) and nerol-10-hydroxylase (NE10H). The induction kinetics of the cloned P-450 protein and of GE10H activity were similar, but those of NE10H were different. Western blots with membranes from other plants suggested that P-450 CYP72 is specific for C. roseus and other plants with GE10H activity. A tentative assignment of CYP72 as GE10H is discussed. The cDNA was recloned for expression in Saccharomyces cerevisiae, and the presence of the protein was demonstrated by western blots. Assays for GE10H failed to detect enzyme activity, and the same negative result was obtained for NE10H and other P-450 enzymes that are present in C. roseus.

[Removal of ceramometal restorations by ultrasound]. / Das Entfernen metallkeramischer Restaurationen mittels Ultraschall.

The removal of dental ceramic restorations by aid of ultrasonic in vitro is described in a scanning electron-microscopical study of 5 crowns and 2 bridges. The ceramic surface was partly destroyed but with little expense it can be corrected in a dental laboratory.

Recognition of a positive MLR within 4 hours using a carrier free electrophoresis system.

Indicator cells--tanned, surface stabilized sheep erythrocytes--were incubated for 1 h in supernatants of 3 h MLCs. Their electrophoretic mobility was measured by an analytical, carrier free electrophoresis system. The change in their mobility compared with an appropriate control was calculated in per cent and correlated with the conventional measured MLR-cpm. The correlation of the two quantities is statistically highly significant (p less than 0.01). Furthermore, the difference of the electrophoretic mobility values of the group of HLA-D-identical and the groups of HLA-D-haploidentical or -different donors is significant beyond the 1% level (p less than 0.0005). Our method enables, therefore recognition of a positive or negative MLC after only 4 h. Typing for HLA-D-determinants seems to be possible. This could be of great importance for histocompatibility testing and organ transplantation.

6-OHDA-induced ectopia of external granule cells in the subarachnoid space covering the cerebellum. III. Morphology and synaptic organization of ectopic cerebellar neurons: a scanning and transmission electron microscopic study.

The present report describes the ultrastructure, surface morphology, and synaptic connectivity of ectopically placed cerebellar neurons after treatment of newborn rats with 100 micrograms 6-hydroxydopamine (6-OHDA), administered intracisternally. In addition to granule cells which form the majority of ectopic neurons, neurons exhibiting the ultrastructure of basket/stellate cells are found in the subarachnoid space over the cerebellum. The ectopic neurons present an almost complete spectrum of homologous efferent and afferent connections. Parallel fiber synapses are found on thorns of spiny branchlets of Purkinje cell dendrites which also have grown out into the subarachnoid space, and on the somata and dendrites of basket/stellate cells. Many ectopic parallel fibers are seen to pass into the molecular layer of the underlying cerebellar cortex through defects in the pial surface, presumably connecting with intracortical postsynaptic partners. Synapses between ectopic Purkinje cell dendrites and basket/stellate cell axons are also observed; however, the source of these axons remains uncertain. Granule cell dendrites are engaged in glomeruli with mossy fibers. Moreover, ectopic granule cell colonies are densely innervated by noradrenergic fibers. Our results show that the technique of generating ectopia of external granule cells provides an additional model for investigating influences of epigenetic factors on the development of nerve cells.

Derivation of cerebellar Golgi neurons from the external granular layer: evidence from explantation of external granule cells in vivo.

The present report provides evidence to challenge the traditional view that cerebellar Golgi cells are derived from the ventricular neuroepithelium, postulating instead that they originate from external granule cells. Supporting evidence for this assertion comes from three sources: 1) Typical Golgi cells are found in ectopic granule cell colonies, both outside the cerebellum (in the subarachnoid space) and also within the cerebellar cortex between fused folia. Because ectopic granule cell colonies are derived from external granule cells, which become displaced after treatment with 6-hydroxydopamine (6-OHDA), it was assumed that the ectopic Golgi cells also stem from such displaced external granule cells. 2) In order to demonstrate that Golgi cell precursors migrate from the external granular layer into the Purkinje cell plate, the development of the cerebellar cortex was studied over the period of Golgi cell genesis. On E19 the external granular layer in the rat is subdivided into an outer proliferative and an inner subproliferative zone. At the inner margin of the external granular layer, and in the marginal zone, radially oriented, darkly staining cells are present that exhibit all the characteristics of migrating neurons possessing a leading process oriented toward the Purkinje cell plate, a somatic cilium, and a close association with radial glia fibers. In later stages, these cells are also found deep to the Purkinje cell plate. Because Golgi cells arise during the period between E19 and postnatal day 2 in the rat (Altman and Bayer, '77, '78) and as the basket cells, the first neurons of proven origin from the external granular layer, are not produced before the second postnatal day (Altman, '72), the earlier migrating neurons are presumed to be Golgi cells. 3) Available data from cell kinetic 3H-thymidine studies show that there is no unequivocal evidence for Golgi cell genesis from the ventricular neuroepithelium, because, at the time of Golgi cell birth, ventricular and external granular stem cell populations are proliferating, and with the present methods it is not possible to decide which of these are the precursors of Golgi cells. Thus, taken together, the findings of this study show that Golgi cells are more likely to arise from the external granular layer than from the ventricular neuroepithelium. This concept would unify cerebellar histogenesis by proposing that projection neurons arise from the ventricular neuroepithelium, whereas all interneurons of the cerebellar cortex are descendants of the external granular layer.

6-Hydroxydopamine induced ectopia of external granule cells in the subarachnoid space covering the cerebellum. II. Differentiation of granule cells: a scanning and transmission electron microscopic study.

The present report describes the morphological differentiation of ectopic granule cells from external granule cells that have been induced to escape from the cerebellar cortex into the subarachnoid space by injecting neonatal rats with 100 microgram 6-hydroxydopamine (6-OHDA) into the cisterna magna. The following cell types were observed in the period between 5 and 25 days postinjection (dpi): (1) unipolar cells with one process bearing a growth cone at its tip; (2) bipolar cells with two thin beaded processes originating from opposite cell poles, bearing growth cones at their tips; (3) bipolar cells with a T-like process at one pole and a short process lacking a terminal growth cone at the opposite pole; (4) multipolar cells with one thin beaded process and two or more short processes bearing growth cones of a different morphology at their tips; (5) intermediate stages. In the late second week p.i., cell aggregates were observed that continually increased in size up to 30 dpi. On the basis of our light, transmission, and scanning electron microscopic findings, we interpret these cell types to be equivalent to the individual stages of granule cell differentiation that characterize axon formation, migration, and aggregation. In the period between 30 and 365 dpi, granule cells were almost exclusively organized into cell colonies of different sizes, but small cell clusters and single granule cells exhibited the scanning electron microscopic features of adult granule cells, i.e., a small spherical cell body, a single axon with parent axonal stem, T-junction, and parallel fiber, and dendrites engaged in synaptic glomeruli. The parallel fibers ran in fasciculi of different sizes, often parallel to each other, but without preferential orientation over the cerebellar surface. During migration and aggregation, the granule cells and their processes were associated with a substrate of glial sheets that in turn were connected to intracortical Bergmann glia fibers. Our findings indicate that (1) granule cells differentiate normally in an ectopic environment in the presence of glia, (2) ectopic Bergmann glia contain no directional information to guide aberrant migratory granule cells to their correct destination, (3) granule cells can survive outside the brain parenchyma for periods up to one year (the longest postinjection interval studied).

6-OHDA-induced ectopia of external granule cells in the subarachnoid space covering the cerebellum. Genesis and topography.

The present report describes the genesis, development and topographical distribution of ectopic cells of the external granular layer in the subarachnoid space covering the rat cerebellum. Following one intracisternal injection to newborn rats of 100 micrograms 6-hydroxydopamine (6-OHDA), the meningeal cells degenerate and are removed by phagocytosis within 24 h post injection (p.i.), leaving the cerebellar cortex without a pia-arachnoid cover. Defects appear in the basal lamina investing the cerebellar cortex 3 to 5 days p.i., and both external granule cells and 'sprouts' from Bergmann-glia endfeet grow into the subarachnoid space. The latter form large, flat glial lamellae and cover extensive areas of the denuded cerebellar surface, although they do not form a glial scar over the exposed neuropil of the cerebellar cortex. The numbers of ectopic external granule cells increase within the subarachnoid space both by proliferation and a continuous efflux of cells from the cerebellar cortex. They migrate, aggregate, and ultimately develop into granule, stellate and basket cells, the morphology of which is indistinguishable from their counterparts in situ; they make specific afferent and efferent connections, both among themselves and with the underlying cerebellar cortex and brainstem. The distribution of ectopic external granule cells and their derivatives is restricted to the anterior vermal fissures and the vermal-hemispheric junctions. The present results indicate that external granule cells and their derivatives are capable of both differentiating normally and surviving in the subarachnoid space if they become associated with glial cells and establish synaptic connections.

Experimental studies on cerebellar foliation. I. A qualitative morphological analysis of cerebellar fissuration defects after neonatal treatment with 6-OHDA in the rat.

The present report describes the natural history of defective cerebellar fissuration in the rat after neonatal treatment with 6-hydroxydopamine (6-OHDA). Within 24 hours after an intracisternal (IC) injection of 100 micrograms 6-OHDA cerebellar pial fibroblasts degenerated almost completely and were phagocytosed b macrophages within 2-5 days postinjection (dpi) leaving the cerebellar surface denuded of pia. Bergmann glia end feet at first exhibited morphological signs of gliosis and later formed new sprouts that penetrated the basal lamina and grew into the subarachnoid space covering regenerating pial fibroblasts and also invading ectopic colonies of external granular layer (EGL) cells. Breaches in the basal lamina appeared after the pial fibroblast had been destroyed and were confined to areas where Bergmann glia end feet were absent and where EGL cells were opposed to the basal lamina. EGL cells escaped through these fractures into the subarachnoid space in the fissures, where they proliferated to form large colonies of granule and stellate cells. In those fissures in which EGL ectopia featured, opposing folia fused and fissures were lost. These findings suggest that pial fibroblasts and the basal lamina have an important role in maintaining lobular partition during development of the cerebellum, in establishing cerebellar fissures, and in consolidating Bergmann glia-EGL cell relationships as a prerequisite for orderly migration of EGL cells.

[Branchial arch development in the rat and mouse. II. The existence of branchial clefts]. / Die Kiemenbogenentwicklung bei Ratte und Maus. II. Zur Existenz von Kiemenspalten.

The development of the branchial arch region was examined at 6- to 12-hour intervals in mice embryos at the age of 9.5-11.5 days after conception [middle of embryonal day (ED) 10 to middle of ED 12] and in rat embryos at the age of 10.5-12.5 days after conception (middle of ED 11 to middle of ED 13) using SEM, serial semithin sections and wax plate reconstructions. The 4th branchial groove is always separated from the corresponding pharyngeal pouch by a broad layer of mesenchyme. At no time did we find a membrana obturans in this region. However, during development of the mesenchyme disappears between the branchial grooves and pharyngeal pouches of the first four arches, allowing external ectodermal epithelium to come into contact with the internal endodermal epithelium to form a membrana obturans. In its dorsal parts this membrane is formed by two layers of epithelium, in the ventral portion frequently it consists of only one layer of epithelium. It was not possible to determine whether the latter was derived from ectoderm or endoderm. Degeneration of cells in this ventral part of the membrane leads to openings which we consider to correspond to branchial clefts. The possibility of an artefactual genesis of these membrane ruptures is discussed. The "1st branchial cleft' appears in mice embryos 15 the age of 9.75 days (second of ED 10), the "2nd branchial cleft' appears first at the age of 10.5 days (middle of ED 11), and the "3rd branchial cleft' appears at the age of 11 days (end of ED 11). In the rat, the corresponding developmental stages are seen about 24 h later. Whereas the "lst and 3rd branchial clefts' are demonstrable during a period of maximally 12 h, the "2nd branchial cleft' is present during the developmental period of about 24-36 h. This protracted existence of the "2nd branchial cleft' is possibly related to the occurrence of lateral cervical fistulas and cysts in the region of the second branchial arch.

[Branchial arch development in the rat and mouse. I. Development of the sinus cervicalis and operculum]. / Die Kiemenbogenentwicklung bei Ratte und Maus. I. Zur Entwicklung von Sinus cervicalis und Operculum.

The development of the branchial arch region was studied in mouse embryos at the age of 10-13 days after conception [end of embryonal day (ED) 10 to end of ED 13] and in rat embryos at the age oa 1-14 days after conception (end of ED 11 to nd of ED 14) using SEM and serial semithin sections. Special attention was paid to the development of the cervical sinus and the branchial operculum. In both rodents, a typical operculum was not found. Instead, the caudal branchial arch region was remodeled by a rapid growth of the second branchial arch, the retrobranchial ridge and the epipericardial ridge, thus forming a progressively deeper grove in this region, the sinus cervicalis. The epithelium of the fourth and sixth branchial arches participated in the formation of the vagus placode, which in later stages was depressed into a grove dorsally and lost its connection with the surface. Finally, the second branchial arch and the cardiac bulge fused compressing the third branchial arch, the second and third branchial grooves and the aperture of the vagus placode. A typical vesicula cervicalis, lined by ectodermal epithelium and collecting the second, third and fourth branchial grooves and the glossopharyngeal and vagus placodes, was not found. However, single or multiple slit-like lumina may persist within the epithelial remnants of the second and third branchial grooves and the vagus placode.

Transitory subependymal cysts in the developing rat rhombencephalon.

A bilaterally symmetrical cystic cavity is situated in the subependymal neuropil of the rostral rhombencephalon of the rat during the perinatal period of ontogeny. These cysts are formed by the confluence of enlarged extracellular spaces in this region between E18 and E20. The cysts are present for about 2 weeks but disappear on about P15 without trace. They have a maximal volume of about 0.004 to 0.006 mm3 on P2, with a rostrocaudal extension of about 200 microm. Their shape is characterized by a medial convexity and a lateral concavity, and they have their maximal circumference at about the middle of the rostrocaudal axis. The caudal portion is juxtaposed to the subependyma, while the rostral part lies in the neuropil of the presumptive griseum centrale pontis. In the lumen and the wall of the cysts are found numerous macrophages, glioblasts and some degenerating axons and dendrites. The significance of these cysts in the context of morphogenesis and the origin of the numerous macrophages within them are both unresolved.

[The arteries of the forehead as the basis of nasal reconstruction with forehead flaps]. / Die Arterien der Stirn als Grundlage des Nasenersatzes mit Stirnlappen.

For the reconstruction of nasal defects, paramedian forehead flaps with a small pedicel are used. The nutrition of these flaps depends on the presence of an arterial blood vessel in the pedicel. In constructing the flap it is absolutely necessary to know the position and the course of the vessles in the forehead. The branches of the ophthalmic artery - dorsal nasal artery, supratrochlear artery, and supraorbital artery - are responsible for the nutrition of the forehead. These arteries are connected with those lying next to them. Additionally, they all anastomose with the frontal branch of the superficial temporal artery. The branches of the ophthalmic artery, lying in a more lateral position, follow a diagonal course compared with those lying more medially. Considering all forehead vessels, the forehead branch of the dorsal nasal artery is widely unknown, although it is very important for the supply of the central part of the forehead. Together with the supratrochlear artery, which lies on a paramedian line passing through the medial angle of the eye, it represents the nutrition vessels of the forehead flap. In case of injury of the ophthalmic artery, the anastomosis of the angular artery with the dorsal nasal artery can be of great importance for the supply of the flap.