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Two species of troglobitic false scorpions, Roncus meledae n. sp. and Neobisium oculatum n. sp. (Neobisiidae, Pseudoscorpiones), are described from inside underground habitat, i.e. the Jama Na Žutim Kokom Cave, the Island of Mljet, Dalmatia, Croatia. The analyzed pseudoscorpions prove to differ from all other congeners. It is possible that the subterranean pseudoscorpions analyzed represent relicts of an old north tropical faunal pattern of the Mediterranean. [Projekat Ministarstva nauke Republike Srbije, br. 173038]

A new genus (Punctoduvalius gen. n.) and a species of trechine ground beetles (Punctoduvalius orlovacensis sp. n.) from Bosnia and Herzegovina have been described and diagnosed. Punctoduvalius gen. n. is clearly distinct from all other phenetically close genera in many important respects, such as: the presence of depigmented reduced eyes, the presence of a pigmented eye border, the presence of deep and complete frontal furrows, the presence of tiny setae on the genae, the presence of distinct longitudinal fissures on the protibias, the ratio of length/width of the first protarsal article in males, the presence of two elytral discal setae, the presence of numerous setiferous punctures in interstrial spaces, the specific position of the humeral setae, and the specific shape of the copulatory piece. This new genus comprises four species: Punctoduvalius pilifer (Ganglbauer, 1891) (endogean from Mts. Treskavica and Bjelašnica, and from a cave on Mt. Visočica, Bosnia and Herzegovina), P. protectus (Winkler, 1926) (from the Pećina kod Ostojića Cave, Mt. Treskavica, and endogean from Mt. Jahorina, Bosnia and Herzegovina), P. brevipilosus (Knirsch, 1927) (endogean from Lupoglav Peak, Mt. Prenj, Bosnia and Herzegovina), and P. orlovacensis sp. n. (from the Orlovača Cave, village of Donje Biševo, near Pale, Bosnia and Herzegovina). The four species clearly differ in many important respects. The following three taxonomic changes are proposed: Punctoduvalius pilifer (Ganglbauer, 1891), comb. n., P. protectus (Winkler, 1926), comb. n., and P. brevipilosus (Knirsch, 1927), comb. n. The new genus and its members belong to an old separate phyletic lineage, distinct from all other existing species groups. Additionally, these forms are relict and endemic to the deep soil and caves of Bosnia and Herzegovina. [Acknowledgments. This study was financially supported by the Serbian Ministry of Education and Science (Grant No. 173038).]

A new leptodirine leiodid beetle species, Parapropus vitorogensis sp. n., from a cave in the western part of the Republic of Srpska, Bosnia and Herzegovina, is described and diagnosed. Both male and female genitalia and other taxonomically important characters are illustrated. The new species is clearly distinct from its closest congeners. The new taxon is of Tertiary or even pre-Tertiary age and originated during the Alpine Orogeny that affected vast areas of the Balkan Peninsula, including the Dinarides, its terra typica. The new species is both endemic and relict, inhabiting western Bosnia and Herzegovina only. [Projekat Ministarstva nauke Republike Srbije, br. 173038 and br. 47007]

The pseudoscorpion sample from a cave in Bosnia has been studied. Two new species have been described herein: Chthonius (Chthonius) protobosniacus n. sp. and C. (C.) kladanjensis n. sp. Both taxa are considered endemic of Bosnia and the Balkan Peninsula. In this paper, diagnostic characters of the analyzed forms are thoroughly described and figured. Taxonomic interrelationship amd geographic distribution are briefly discussed.

A new species of epigean pseudoscorpion pertaining to the genus Chthonius C. L. Koch 1843 from Macedonia is erected. Its relationship to phenetically close congeners is briefly discussed. The new species, Chthonius (Ephippiochthonius) lagadini n. sp. is a relict form presently known only from its type locality (Lagadin, nr. Ohrid, Macedonia).

A new pseudoscorpion from the family Chthoniidae - Chthonius (Chthonius) aquasanctae n. sp. from west Serbia is described. The newly erected taxon is endemic to the area studied. Its taxonomic relationship to its phenetically close congeners Chthonius (Chthonius) lesnik Ćurčić and Chthonius (Chthonius) iugoslavicus Ćurčić, as well as the comparative morphological traits, are described in detail.

A new cave-dwelling pseudoscorpion from the Badanj (or Vilišnica) Cave, nr. Sveti Filip i Jakov, Dalmatia (Croatia) is thoroughly described and illustrated. Its main morphometric characteristics and important diagnostic traits are analyzed and compared to those of its phenetically close congener Chthonius (Chthonius) absoloni Beier from Dalmatia. The new species is relict and endemic to the area studied.

Two new epigean pseudoscorpion species belonging to the family Chthoniidae - Chthonius (Ephippiochthonius) metohicus n. sp. and Chthonius (Ephippiochthonius) civitatisveti n. sp. from the UN Administered Province of Kosovo and Southern Croatia, respectively, are described. The newly erected taxa are endemic to each of the areas studied. Their taxonomic relationship with their phenetically close congeners Chthonius (Ephippiochthonius) bidentatus Beier, 1939, Chthonius (Ephippiochthonius) kemza Ćurčić, Lee et Makarov, 1993 and Chthonius (Ephippiochthonius) tetrachelatus (Preyssler, 1790) and comparative morphological traits are described.

Two new endemic cave pseudoscorpion species from the Petropavlova Pećina Cave, village Bihovi, 6 km from Trebinje, Herzegovina, are presented, thoroughly described and illustrated. These are named Chthonius (Globochthonius) petroupauli n. sp. and Roncus paulipetrou n. sp. Their main morphometric characteristics and important diagnostic features are analyzed and compared to those of their phylogenetically closest congeners.

Three new species of the pseudoscorpion genus Roncus L. Koch (Neobisiidae) are described from Croatia (from nr. Omiš, Dalmatia: R. almissae n. sp.) and Serbia (near the town of Krupanj, north-western Serbia, Lukića Pećina Cave and nr. Izvor: R. krupanjensis n. sp., and R. radji n. sp.), and their diagnostic characteristics are illustrated. Their interrelations with phenetically close congeners are analyzed; in addition, the presence/absence of microsetae proximal to the trichobothria eb and esb is established as an important taxonomic characteristic.

A new epigean pseudoscorpion, Chthonius (Chthonius) onaei n. sp. is erected from Podašpilje, nr. Omiš, Mt. Omiška Dinara, Dalmatia, Croatia. Its interrelations with two close congeners, Chthonius (C.) litoralis Hadži, 1933 and Chthonius (C.) dalmatinus Hadži, 1930 are briefly discussed.

A careful analysis of samples of pseudoscorpions (Neobisiidae, Pseudoscorpiones) from two epigean habitats, one near Split (Croatia) and the other on Mt. Orjen (Montenegro), has yielded two species of the genus Roncus L. Koch new to science: Roncus diocletiani n. sp. and R. orjensis n. sp. Both new species are described, thoroughly illustrated, and diagnosed. Some biogeographical and evolutionary characteristics of the two taxa are briefly discussed.

A new species of the endemic pseudoscorpion genus Protoneobisium Ćurčić, 1988, P. basilice sp. n. from Croatia has been found, described and diagnosed. From its phenetically close congener, P. biocovense (Müller, 1931), the new taxon differs in many respects of both qualitative and quantitative nature. Both species of Protoneobisium have a limited distribution; they inhabit Mt. Biokovo, Croatia, and are probably the remnants of some ancient Maditerranean fauna of pre-Tertiary origin.

Abstract Background The corpus luteum (CL) is a transient endocrine gland and prostaglandin F2-alpha is considered to be the principal luteolysin in pigs. In this species, the in vivo administration of prostaglandin F2-alpha induces apoptosis in large vessels as early as 6 hours after administration. The presence of the prostaglandin F2-alpha receptor (FPr) on the microvascular endothelial cells (pCL-MVECs) of the porcine corpus luteum has not yet been defined. The aim of the study was to assess FPr expression in pCL-MVECs in the early and mid-luteal phases (EL-p, ML-p), and during pregnancy (P-p). Moreover, the effectiveness of prostaglandin F2-alpha treatment in inducing pCL-MVEC apoptosis was tested. Methods Porcine CLs were collected in the EL and ML phases and during P-p. All CLs from each animal were minced together and the homogenates underwent enzymatic digestion. The pCL-MVECs were then positively selected by an immunomagnetic separation protocol using Dynabeads coated with anti-CD31 monoclonal antibody and seeded in flasks in the presence of EGM 2-MV (Microvascular Endothelial Cell Medium-2). After 4 days of culture, the cells underwent additional immunomagnetic selection and were seeded in flasks until the confluent stage. PCR Real time, western blot and immunodetection assays were utilized to assess the presence of FPr on pCL-MVEC primary cultures. Furthermore, the influence of culture time (freshly isolated, cultured overnight and at confluence) and hormonal treatment (P4 and E2) on FPr expression in pCL-MVECs was also investigated. Apoptosis was detected by TUNEL assay of pCL-MVECs exposed to prostaglandin F2-alpha. Results We obtained primary cultures of pCL-MVECs from all animals. FPr mRNA and protein levels showed the highest value (ANOVA) in CL-MVECs derived from the early-luteal phase. Moreover, freshly isolated MVECs showed a higher FPr mRNA value than those cultured overnight and confluent cells (ANOVA). prostaglandin F2-alpha treatment failed to induce an apoptotic response in all the pCL-MVEC cultures. Conclusion Our data showing the presence of FPr on MVECs and the inability of prostaglandin F2-alpha to evoke an in vitro apoptotic response suggest that other molecules or mechanisms must be considered in order to explain the in vivo direct pro-apoptotic effect of prostaglandin F2-alpha at the endothelial level.

Abstract: Cu(In,Ga)Se2 absorbers were investigated by surface photovoltage (SPV) in the Kelvin probe and fixed capacitor arrangements before and after deposition of CdS or In2S3 buffer layers as well as before and after deposition of ZnO window layers. Effects such as passivation of surface states, partial electron transfer from ZnO into In2S3, decrease of the ideality factor after deposition of ZnO and slow electron transfer through In2S3 were demonstrated. The results show that SPV measurements open opportunities for dedicated studies of charge separation at hetero-junctions between ordered and disordered semiconductors. [Copyright &y& Elsevier]

In this paper, spectrally resolved cathodoluminiscence (CL) study of hydrothermally grown ZnO crystals is presented. These crystals are characterized by good crystalline quality; however a high density of impurities is present. Different growth sectors through CL images are identified in these crystals. A Spectrally resolved analysis proves that the incorporation of impurities and non-radiative recombination centres depend on the growth sector. The surface termination should introduce band tailing states responsible for the self-absorption of the photons with the higher energy in the luminescence spectrum (free excitons). [ABSTRACT FROM AUTHOR]

Atomic force microscope has been widely used to detect surface contact potential with atomic resolution; however, incidence of geometric parameters on lateral resolution has not been studied deeply yet. In this paper, we develope a simulation model in ANSYS® using Finite Element Theory to analyze electrostatic interaction of the system through the simulation of the force and the capacitance of the system. The model has been validated based on previous models and the results obtained are coherent with them. Finally, we have found a comparative method of lateral resolution for random geometries with constant tip radii. [ABSTRACT FROM AUTHOR]

Seoda cavernicola sp. nov. and Psychoda glamocensis sp. nov., are new species and cave dwellers from Bosnia and Hercegovina, and Croatia. Adults of S. cavernicola are pale and small; the eye bridge is reduced, ommatidia irregularly arranged, epandrium with a pair of setose excrescences. The eye bridge of P. glamocensis is likewise reduced with 2 or 3 irregularly ordered facet rows, palpus segments of some individuals are malformed; its closest relative is Psychoda alticola Vaillant based on the morphology of male and female genitalia as well as on COI barcodes.

Cells constitute one of the fundamental components of any cartilage tissue engineering approach. Adipose tissue derived stem cells (ASCs) have a promising future considering the abundance of this tissue in the human body, ease of harness, and the high number of stem cells that can be isolated from small amounts of tissue. However the stromal vascular fraction of the adipose tissue that is isolated upon digestion by collagenase followed by a rough selection of the adherent cells, is composed of many different types of cells, some of which may compromise the proliferation and the differentiation of the ASCs. This manuscript reports a study on the in vivo chondrogenic potential of two ASCs specific subpopulations isolated using a method based on immunomagnetic beads coated with specific antibodies. These ASCs subpopulations, isolated using immunomagnetic beads coated with CD29 and CD105 antibodies, were subsequently transfected with green fluorescent protein (GFP), expanded, and pre-differentiated into the chondrogenic lineage, before being encapsulated in a novel hydrogel based on gellan gum, that has recently been showed to promote in vitro and in vivo cartilage tissue formation. The two ASCs subpopulations encapsulated in the gellan gum hydrogel and in vitro pre-differentiated, were then subcutaneously implanted in nude mice for 6 weeks. Explants were analyzed by various techniques, namely histology, immunohistology and real time RT-PCR that demonstrated the different behaviour of the two ASCs subpopulations under study, namely their potential to differentiate into the chondrogenic lineage and to form new cartilage tissue.

Human adipose tissue has been recently recognized as a potential source of stem cells for regenerative medicine applications, including bone tissue engineering (TE). Despite the gathered knowledge regarding the differentiation potential of human adipose tissue-derived stem cells (hASCs), in what concerns the endothelial lineage many uncertainties are still present. The existence of a cell subpopulation within the human adipose tissue that expresses a SSEA-4 marker, usually associated to pluripotency, raises expectations on the differentiation capacity of these cells (SSEA-4(+)hASCs). In the present study, the endothelial and osteogenic differentiation potential of the SSEA-4(+)hASCs was analyzed, aiming at proposing a single-cell source/subpopulation for the development of vascularized bone TE constructs. SSEA-4(+)hASCs were isolated using immunomagnetic sorting and cultured either in α-MEM, in EGM-2 MV (endothelial growth medium), or in osteogenic medium. SSEA-4(+)hASCs cultured in EGM-2 MV formed endothelial cell-like colonies characterized by a cobblestone morphology and expression of CD31, CD34, CD105, and von Willebrand factor as determined by quantitative reverse transcriptase (RT)-polymerase chain reaction, immunofluorescence, and flow cytometry. The endothelial phenotype was also confirmed by their ability to incorporate acetylated low-density lipoprotein and to form capillary-like structures when seeded on Matrigel. SSEA-4(+)hASCs cultured in α-MEM displayed fibroblastic-like morphology and exhibited a mesenchymal surface marker profile (>90% CD90(+)/CD73(+)/CD105(+)). After culture in osteogenic conditions, an overexpression of osteogenic-related markers (osteopontin and osteocalcin) was observed both at molecular and protein levels. Matrix mineralization detected by Alizarin Red staining confirmed SSEA-4(+)hASCs osteogenic differentiation. Herein, we demonstrate that from a single-cell source, human adipose tissue, and by selecting the appropriate subpopulation it is possible to obtain microvascular-like endothelial cells and osteoblasts, the most relevant cell types for the creation of vascularized bone tissue-engineered constructs.

Bone marrow has been the elected cell source of studies published so far concerning bone and cartilage tissue-engineering approaches. Recent studies indicate that adipose tissue presents significant advantages over bone marrow as a cell source for tissue engineering. Most of these studies report the use of adipose stem cells (ASCs) isolated by a method based on the enzymatic digestion of the adipose tissue and on the ability of stem cells to adhere to a cell culture plastic surface. Using this method, a heterogeneous population was obtained containing different cell types that have been shown to compromise the proliferation and differentiation potential of the stem cells. This paper reports the development and optimization of a new isolation method that enables purified cell populations to be obtained that exhibit higher osteogenic differentiation and/or proliferation potential. This method is based on the use of immunomagnetic beads coated with specific antibodies and it is compared with other methods described in the literature for the selection of stem cell populations, e.g. methods based on a gradient solution and enzymatic digestion. The results showed that the isolation method based on immunomagnetic beads allows distinct subpopulations of rat ASCs to be isolated, showing different stem cells marker expressions and different osteogenic differentiation potentials. Therefore, this method can be used to study niches in ASC populations and/or also allow adipose tissue to be used as a stem cell source in a more efficient manner, increasing the potential of this cell source in future clinical applications., (Copyright © 2011 John Wiley & Sons, Ltd.)

Recently adipose tissue has become a research topic also for the searching for an alternative stem cells source to use in cell based therapies such as tissue engineer. In fact Adipose Stem Cells (ASCs) exhibit an important differentiation potential for several cell lineages such as chondrogenic, osteogenic, myogenic, adipogenic and endothelial cells. ASCs populations isolated using standard methodologies (i.e., based on their adherence ability) are very heterogeneous but very few studies have analysed this aspect. Consequently, several questions are still pending, as for example, on what regard the existence/ or not of distinct ASCs subpopulations. The present study is originally aimed at isolating selected ASCs subpopulations, and to analyse their behaviour towards the heterogeneous population regarding the expression of stem cell markers and also regarding their osteogenic and chondrogenic differentiation potential. Human Adipose derived Stem Cells (hASCs) subpopulations were isolated using immunomagnetic beads coated with several different antibodies (CD29, CD44, CD49d, CD73, CD90, CD 105, Stro-1 and p75) and were characterized by Real Time RT-PCR in order to assess the expression of mesenchymal stem cells markers (CD44, CD73, Stro-1, CD105 and CD90) as well as known markers of the chondrogenic (Sox 9, Collagen II) and osteogenic lineage (Osteopontin, Osteocalcin). The obtained results underline the complexity of the ASCs population demonstrating that it is composed of several subpopulations, which express different levels of ASCs markers and exhibit distinctive differentiation potentials. Furthermore, the results obtained clearly evidence of the advantages of using selected populations in cell-based therapies, such as bone and cartilage regenerative medicine approaches.

In this work, the ability of gellan gum hydrogels coupled with autologous cells to regenerate rabbit full-thickness articular cartilage defects was tested. Five study groups were defined: (a) gellan gum with encapsulated chondrogenic predifferentiated rabbit adipose stem cells (ASC + GF); (b) gellan gum with encapsulated nonchondrogenic predifferentiated rabbit adipose stem cells (ASC); (c) gellan gum with encapsulated rabbit articular chondrocytes (AC) (standard control); (d) gellan gum alone (control); (e) empty defect (control). Full-thickness articular cartilage defects were created and the gellan gum constructs were injected and left for 8 weeks. The macroscopic aspect of the explants showed a progressive increase of similarity with the lateral native cartilage, stable integration at the defect site, more pronouncedly in the cell-loaded constructs. Tissue scoring showed that ASC + GF exhibited the best results regarding tissue quality progression. Alcian blue retrieved similar results with a better outcome for the cell-loaded constructs. Regarding real-time PCR analyses, ASC + GF had the best progression with an upregulation of collagen type II and aggrecan, and a downregulation of collagen type I. Gellan gum hydrogels combined with autologous cells constitute a promising approach for the treatment of articular cartilage defects, and adipose derived cells may constitute a valid alternative to currently used articular chondrocytes., ((c) 2010 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.)

In our previous work, biomimetic calcium phosphate-coated poly(caprolactone) nanofibre meshes (BCP-NMs) were demonstrated to be more effective for supporting cell attachment and proliferation under static conditions, when compared with poly(caprolactone) nanofibre meshes (PCL-NMs). In many applications, in vitro cultivation of constructs using bioreactors that support efficient nutrition of cells has appeared as an important step toward the development of functional grafts. This work aimed at studying the effects of dynamic culture conditions and biomimetic coating on bone cells grown on the nanofibre meshes. BCP-NM and PCL-NM were seeded with osteoblast-like cells (MG63--human osteosarcoma-derived cell line). The cell-seeded constructs were cultured within a rotating bioreactor that simulated microgravity, at a fixed rotating speed, for different time periods, and then characterized. Cell morphology, viability, and phenotype were assessed. PCL-NM constructs presented a higher number of dead cells than BCP-NM constructs. Under dynamic conditions, the production of proteins associated with the extracellular matrix of bone was higher on BCP-NM constructs than in the PCL-NM ones, which indicates that coated samples may provide cells with a better environment for tissue growth. It is suggested that improved mass transfer in the bioreactor in combination with the appropriate substrate were decisive factors for this highly positive outcome for generating bone.

The adipose tissue was considered a reserve of energy until the '80s, when it was found that this tissue was involved in the metabolism of sex steroids such as estrogens. From then on, the importance attributed to this tissue radically changed as it was then considered an active organ, involved in important functions of the human body. In 2001, for the first time, the existence of stem cells within this tissue was reported, and since then, this tissue has been gaining an increased importance as a stem cell source for a wide range of potential applications in cell therapies and/or tissue engineering and regenerative medicine strategies, mainly due to its wide availability and easy access. This manuscript provides an overview on adipose stem cells (i.e., adipose tissue-derived stem cells, ASCs) considering the tissue of origin, the niche of the ASCs, and their phenotype in all aspects. In this paper it is also discussed the markers that have been used for the characterization of these cells, their differentiation properties, and their immunological reactivity, reporting studies from 2001 until this date. The ASCs are also compared with bone marrow stem cells (BMSCs), until now considered as the gold standard source of stem cells, underlining the common characteristics and the differences between the stem cells obtained from these two sources, as well as the advantages and disadvantages of their potential use in different applications. Finally, this review will also focus on the potential application of ASCs in tissue engineering applications, particularly in the regeneration of bone and cartilage, commenting on the progress of this approach and future trends of the field.

Background: The corpus luteum (CL) is a transient endocrine gland and prostaglandin F2-alpha is considered to be the principal luteolysin in pigs. In this species, the in vivo administration of prostaglandin F2-alpha induces apoptosis in large vessels as early as 6 hours after administration. The presence of the prostaglandin F2-alpha receptor (FPr) on the microvascular endothelial cells (pCL-MVECs) of the porcine corpus luteum has not yet been defined. The aim of the study was to assess FPr expression in pCL-MVECs in the early and mid-luteal phases (EL-p, ML-p), and during pregnancy (P-p). Moreover, the effectiveness of prostaglandin F2-alpha treatment in inducing pCL-MVEC apoptosis was tested., Methods: Porcine CLs were collected in the EL and ML phases and during P-p. All CLs from each animal were minced together and the homogenates underwent enzymatic digestion. The pCL-MVECs were then positively selected by an immunomagnetic separation protocol using Dynabeads coated with anti-CD31 monoclonal antibody and seeded in flasks in the presence of EGM 2-MV (Microvascular Endothelial Cell Medium-2). After 4 days of culture, the cells underwent additional immunomagnetic selection and were seeded in flasks until the confluent stage.PCR Real time, western blot and immunodetection assays were utilized to assess the presence of FPr on pCL-MVEC primary cultures. Furthermore, the influence of culture time (freshly isolated, cultured overnight and at confluence) and hormonal treatment (P4 and E2) on FPr expression in pCL-MVECs was also investigated. Apoptosis was detected by TUNEL assay of pCL-MVECs exposed to prostaglandin F2-alpha., Results: We obtained primary cultures of pCL-MVECs from all animals. FPr mRNA and protein levels showed the highest value (ANOVA) in CL-MVECs derived from the early-luteal phase. Moreover, freshly isolated MVECs showed a higher FPr mRNA value than those cultured overnight and confluent cells (ANOVA). prostaglandin F2-alpha treatment failed to induce an apoptotic response in all the pCL-MVEC cultures., Conclusion: Our data showing the presence of FPr on MVECs and the inability of prostaglandin F2-alpha to evoke an in vitro apoptotic response suggest that other molecules or mechanisms must be considered in order to explain the in vivo direct pro-apoptotic effect of prostaglandin F2-alpha at the endothelial level.

A set of eight derivatives of 6,8-dichloro-3-phenyl-2H-benzoxazine-2,4(3H)-dione and nine derivatives of 6,8-dibromo-3-phenyl-2H-1, 3-benzoxazine-2,4(3H)-dione, substituted on the phenyl ring, was prepared by the reaction of the corresponding salicylanilides with ethyl chloroformate. The compounds were evaluated in vitro for antimycobacterial activity against Mycobacterium tuberculosis, Mycobacterium kansasii, and Mycobacterium avium. Their activity increases with increasing hydrophobicity and electron-withdrawing ability of the substituents on the phenyl ring.

The subcellular localization of peptide antibodies against G-protein alpha subunits was studied by the indirect immunogold technique with Lowicryl K4M embedded rat cardiac tissue. Two antibodies were used. The alpha common peptide antibody recognizes the alpha subunits of Gs, Gi and Go. The alpha i common peptide antibodies recognize the alpha subunits of all Gi alpha subtypes (G1-3). Immunoreactivity against alpha common and alpha i common antibodies was found along the cell surface of cardiomyocytes and endothelial cells. No immunoreactivity was seen on sarcoplasmic reticulum membranes. T-tubule membranes showed a little reactivity. Distribution patterns obtained with alpha common and alpha i common antibodies were identical. Immunogold was seen in cardiocytes from both atria and ventricles. In light-microscopical studies with peroxidase-conjugated secondary antibodies, heavy immunostaining was seen in SA and AV nodes.

Under physiological conditions different parts of the heart reveal superspecialization of the myocardium reflected by biochemical, functional, structural and histochemical differences, which are even more pronounced under pathological conditions. Postischemic reperfusion, Ca paradox and injury caused by reactive oxygen species were found to result in transmurally unhomogenous damage of the ventricular wall. In the present experiments isolated perfused rat hearts were subjected to damage by the above mechanism and a different vulnerability of defined parts of the heart was observed. Activities of glycogen phosphorylase, SDH, beta-HBDH, and LDH were studied histochemically in both ventricles, the atria and the specialized conductive system of the heart. Marked decreases of activities were observed in the ventricular muscle. The enzyme activities were less decreased in the atrial muscle. Conductive fibres were the least affected tissue in this respect. The differential changes were most sensitively reflected by glycogen phosphorylase. The differences in transmural distribution of damage were shown to be dependent on a complex of specific factors such as intramural pressure gradient, transmural pressure, end-diastolic intraventricular pressure, differences in transmural vessel distribution, transmural hematocrit differences, blood flow, perfusate volume, and endothelial injuries of different origin. It can be concluded that differences in ultrastructure as well as in enzyme activities in different parts of the heart reflect functional, structural and metabolic heterogeneity of the different functional parts of the heart muscle.

Polyclonal specific antisera to beta-receptors were prepared by immunization of rabbits with beta-receptors isolated from a dog myocardium according to Becker et al. (1988). Cryostat sections of the dog heart were fixed in paraformaldehyde in PBS, and incubated with polyclonal antisera to beta-receptors. Sections were then washed and incubated in peroxidase-labelled anti-rabbit antibody. After visualization of the tissue-bound peroxidase with diaminobenzidine, sections were dehydrated in graded alcohols and mounted in Canada balsam. The results demonstrate specific reaction of antibodies on the myocyte sarcolemma.