Translation, cross-cultural adaptation, reliability, and validity of the Turkish version of the Duke Activity Status Index in patients with pulmonary hypertension.

BACKGROUND AND OBJECTIVES: In patients with pulmonary hypertension (PH), shortness of breath, fatigue, chest pain, and syncope limit exercise capacity. Exercise tests are often time-consuming, expensive, and some patients may not be able to perform such procedures and they are also difficult to apply in the studies including large samples. The aim of this study was to translate and culturally adapt the DASI into Turkish and to investigate its reliability and validity in patients with PH. METHODS: The final Turkish version of the DASI questionnaire was applied to 109 clinically stable patients with a diagnosis of PH. Exercise capacity of the patients was determined by maximal VO 2 achieved in the 6-minute walk test (6MWT) and quality of life by the EmPHasis-10 questionnaire. Cronbach alpha (internal consistency) was used to assess the questionnaire's reliability. The validity assessment was performed by using Spearman correlation. RESULTS: Internal consistency of the DASI was high (Cronbach's alpha = 0.99) and the test-retest reliability was excellent (ICC = 0.98). Validity was supported by significant correlations of DASI-VO 2 scores with estimated VO 2 (6MWT) scores (r = 0.58, p < 0.0001) and EmPHasis-10 (= -0.62, p < 0.0001). No floor or ceiling effect was present for the questionnaire. CONCLUSIONS: The Turkish version of the culturally adapted DASI questionnaire was found to be a valid and reliable assessment tool. It is a rapidly administered, simple-toscore questionnaire for assessing the functional ability of individuals with PH. The use of the DASI to assess exercise capacity in patients with PH may assist researchers and clinicians detecting functional impairment in these patients.

Exercise capacity, lung and respiratory muscle function in substance use disorders.

BACKGROUND: Substance use disorder (SUD) causes conditions such as cognitive and behavioral disorders, anxiety, depression, and social isolation it also causes acute airway inflammation by affecting airway bronchial dynamics. The current study aimed to investigate the lung function, respiratory muscle strength, and exercise capacity in patients with SUD. METHODS: One hundred-eighty three patients with SUD, a total of 119 healthy controls, 54 of whom were cigarette smokers and 65 of whom were non-smokers were included in the study. Spirometric tests, respiratory muscle strength (MIP and MEP), and the 6-Minute Walk Test (6-MWT) were assessed. The III National Health and Nutrition Examination Survey were used to evaluate respiratory symptoms in patients with SUD and cigarette smokers. RESULTS: 86.3% of the SUD patients included in the study were using heroin, 9.2% were cannabis, and 5.5% were spice. The most common symptom in both SUD patients and cigarette smokers was shortness of breath, wheezing, and sputum production. After post-hoc tests, the FVC (p = 0.002), FVC (%predicted) (p < 0.0001), FEV1 (p = 0.002), FEV1 (%predicted) (p < 0.0001), FEV1/FVC (%) (p < 0.0001), PEF (p < 0.0001) and FEF%25-75 (p < 0.0001) lung function parameters were significantly lower in SUD patients than non-smokers. In addition, it was found that MIP (p < 0.0001), MIP (%predicted) (p < 0.0001), MEP (p < 0.0001), and MEP (%predicted) (p < 0.0001) values of SUD patients were significantly lower than non-smokers. CONCLUSION: The study findings indicate that substance use has an effect on lung functions and the most commonly reported symptoms are shortness of breath, wheezing, and sputum production. In addition, respiratory muscle strength and exercise capacity were decreased in SUD patients compared to non-smokers.

Heavy metal and essential elements in beers from turkey market: A risk assessment study.

In this study, the level of arsenic (As), lead (Pb) and cadmium (Cd) and also essential elements in beer samples consumed in Turkey were investigated using the inductively coupled plasma mass spectrometry (ICP-MS) method. The heavy metal-induced non-carcinogenic and carcinogenic risks were calculated. For essential elements, the calculated estimated daily intake of iron (Fe), copper (Cu), selenium (Se) and cobalt (Co) from beer consumption were compared with their toxicity reference values. Tukey post-hoc test showed that As was found at a significantly higher level when compared to Pb. Also, a significant correlation was found between As level and alcohol by volume percent. All samples had a hazard quotient and hazard index <1, indicating no non-carcinogenic risk from exposure to single or multiple heavy metals. Some samples exceeded the threshold limit of acceptable cancer risk for As in the high beer consumer group. This assessment showed that in addition to health implications based on the alcohol content of beer, there might be a carcinogenic risk associated with the heavy metals content of these beverages.

The effect and safety of the treatment of recurrent hepatitis C infection after orthotopic liver transplantation with pegylated interferon α2b and ribavirin.

INTRODUCTION: Recurrent hepatitis C infection in the posttransplant setting is a serious problem. The aim of this study was to evaluate the efficacy, safety, indications, optimal time of administration and adequate duration of antiviral therapy with pegylated interferon alpha 2 b (PEG-IFN) and ribavirin (RIB). PATIENTS AND METHODS: Between 2003 and 2009, 16 patients received antiviral therapy (PEG-IFN: 0.8-1.6 µg/kg/wk, RIB 800-1200 mg/d) for at least 6 months. Patients with a biochemical without a virologicalresponse after 12 months of therapy received antiviral treatment for a further 6 months. Hepatitis C virus load was determined at 1, 3, 6, and 12 months after start of therapy. Liver biopsy was performed in all patients before the beginning and after the end of treatment. RESULTS: The mean period of antiviral therapy was 14 months. The four patients who received the full-length treatment (12 months, 33%) showed sustained virological responses (SVR) and 8 showed virological and biochemical responses (VR, BR). Patients with SVR showed significant improvement in the grading and staging of HAI (histological activity index; P=.03). Nine patients had several side effects under antiviral treatment. Acute rejection episodes were not observed. CONCLUSION: The antiviral treatment combination using PEG-IFN and RIB for recurrent hepatitis C is effective procedure. The SVR of 33% after 12 months of treatment with significant improvement in HAI grading and staging and stable HAI in all treated patients favor early initiation and 12-month administration of antiviral treatment. Furthermore, all patients with BR without VR, who underwent antiviral treatment for a further 6 months, achieved a VR. However, the optimal duration of treatment needs to be investigated in large prospective studies.

The presence of kinesin superfamily motor proteins KIFC1 and KIF17 in normal and pathological human placenta.

Kinesin superfamily proteins (KIFs) are motor proteins that participate in chromosomal and spindle movements during mitosis and meiosis, and transport membranous organelles and macromolecules fundamental for cellular functions. Although the roles of KIFs in axonal and dendritic transports have been studied extensively, their role in intracellular transport in general is less well known. The diversity of kinesins suggests that each kinesin may have a specific function. Therefore, in this study we aimed to investigate the presence and cellular localization of KIFC1 and KIF17 in normal and pathological human placentas. First-trimester (22-56 days) and normal, preeclamptic (PE), and diabetic-term placental tissues were obtained and further studied by immunohistochemistry (IHC) and Western blot methods. KIFC1 was mainly localized to the syncytiotrophoblast both in early and term placental samples. However, a stronger immunoreactivity was observed both in PE and diabetic placentas compared to normal-term placentas. KIF17 was most intensively localized in developing vascular endothelium in early pregnancy. Even though KIF17 was moderately stained in the endothelium of villi from normal human-term placentas, stronger immunoreactivity was observed in all types of villi of both PE and diabetic placentas. Western blotting of tissue extracts confirmed the IHC results. Here, we demonstrate the presence of KIFC1 and KIF17 in human placenta for the first time. The intense expression of KIFC1 in syncytiotrophoblast and KIF17 in vascular endothelium suggests that both the proteins might be important in a cargo-transport system. An increased expression pattern of both KIFC1 and KIF17 in PE and diabetes might suggest that these proteins may be involved in complex trophoblast functions and placental pathologies. Further studies will clarify the physiological role of KIFs in human placental transport and development.

Changes in the brain cortex of rabbits on a cholesterol-rich diet following supplementation with a herbal extract of Tribulus terrestris.

Extracts of the medicinal herb Tribulus terrestris (TT) are used for treating various diseases. The saponins, a component of TT, play a role in regulating blood pressure and in treatment of hyperlipidemia. The aim of the study was to investigate the immunohistochemical and ultrastructural alterations in the cerebral cortex of experimental rabbits on a cholesterol rich diet treated with TT. The rabbits were divided into three groups and followed for 12 weeks as control group (CG); experimental group I (EG-I), fed with a cholesterol-rich diet; experimental group II (EG-II), treated with an extract of TT (5 mg/kg/day) after a cholesterol-rich diet of 4 weeks. In EG-I there were ultrastructural changes, including mitochondrial degeneration, increased lipofuscin pigments, myelin sheath damage with axoplasmic shrinkage and electron dense granules in the neurovascular unit. The number of synapses apparently decreased in both experimental groups. Administration of TT extract in EG-II led to marked ultrastructural alterations in neurons, including decreased mitochondrial degeneration (P<0.001) and extensive oedematous areas in the neurovascular unit. However, in EG-II, lamellar myelin, axonal structures and mitochondria were well protected. These alterations possibly indicate that saponins have an effect on the neurons either directly or by its conversion to steroidal saponins. Therefore, these findings add further evidence supporting the protective claims of TT in cerebral architecture in dietary induced hyperlipidemia.

Type-2 diabetes down-regulates glucose transporter proteins and genes of the human blood leukocytes.

OBJECTIVE: White blood cells are essential in mediating immune and inflammatory responses. A prominent feature of these cells during activation of the immune function is increased glucose utilization, and this is dependent on the functioning of specific glucose transporter (GLUT) isoforms. The few data available on leukocyte glucose transporter expression are limited to type-2 diabetes mellitus, and nothing is known about its regulation. MATERIAL AND METHODS: Peripheral blood was drawn from 35 healthy controls and 35 diabetic subjects. Expression of GLUT1, GLUT3 and GLUT4 was determined in the leukocytes of healthy individuals and diabetic patients by flow cytometry, Western blot and semi-quantitative RT-PCR. RESULTS: GLUT 3 was decreased in granulocytes, lymphocytes and monocytes from diabetic patients. In monocytes, GLUT3 and GLUT4 were reduced in type-2 diabetic patients. In leukocytes of diabetic patients, GLUT1 and GLUT4, protein and mRNA were unchanged, but GLUT3 protein and mRNA levels were down-regulated compared to those of healthy controls. CONCLUSION: Elevated glucose concentration affects leukocyte GLUT expression. Decreased expression of GLUT isoforms in leukocytes may be responsible for diminished activation of diabetic leukocytes. These situations possibly contribute to a predisposition to infection and to a decreased immune response in diabetes.

The distribution of angiopoietin-1, angiopoietin-2 and their receptors tie-1 and tie-2 in the very early human placenta.

Angiopoietins are integral to vasculogenesis and angiogenesis, which play crucial roles in the growth and development of the placenta. The current study assessed expression of angiopoietins (Ang-1 and Ang-2) and their receptors (Tie-1 and Tie-2) during development of the early human placenta. First-trimester placental tissues were obtained from women undergoing curettage during normal pregnancies. The use of immunohistochemistry (IHC) showed that Ang-1 was primarily localized to syncytiotrophoblasts where it displayed moderate immunoreactivity, whereas weak immunoreactivity for Ang-1 was observed in endothelial cells and angiogenic cell cords (ACC). Strong immunoreactivity for Ang-2 was also found predominantly in syncytiotrophoblasts with lower immunostaining levels evident in cytotrophoblasts. Moderate immunoreactivity for Ang-2 was observed in endothelial cells, ACC and Hofbauer cells. By contrast, the trophoblastic shell, as well as endothelial cells and ACC exhibited strong staining intensity for Tie-1 with the strongest immunoreactivity for Tie-2 observed in cytotrophoblasts, ACC and endothelial cells. Western blotting of tissue extracts confirmed the IHC results. Previous studies focused on VEGF and its receptors in controlling vasculogenesis and angiogenesis in human placenta. However, the specific localization patterns of angiopoietins and their receptors revealed by the current study emphasize the importance of these molecules in placental vascular development. Functional studies aimed at identifying the molecular mechanisms of actions of these factors and receptors may prove essential in elucidating the pathophysiology of placental disorders such as intrauterine growth restriction and pre-eclampsia.

Breathing-enhanced upper extremity exercises for patients with multiple sclerosis.

OBJECTIVE: To explore the effectiveness of breathing-enhanced upper extremity exercises on the respiratory function of patients with multiple sclerosis. DESIGN: Randomized controlled study of six-week duration. SUBJECTS: Forty patients with multiple sclerosis (age 39.2 +/- 7 years; Kurtzke Expanded Disability Status Scale scores: 4.51 +/- 1.55) randomly divided into two groups. METHODS: The training group followed a six-week home training programme designed to strengthen accessory respiratory muscles. Controls performed no exercises. All subjects submitted to baseline and post-training tests of spirometry, respiratory muscle strength and 6-minute walking. They were also assessed with pulmonary dysfunction and exertion fatigue indices. RESULTS: Spirometry revealed clear improvement in forced expiratory volume in 1 second (FEV1) (+13%, P = 0.003) resulting in higher FEV1/FVC (forced vital capacity) (+8.5%, P = 0.03). Maximal inspiratory pressure (P (Imax)) increased by +7.1% but not significantly. Maximal expiratory pressure (P(Emax)) and FVC were significantly higher (by +7.1%, P = 0.0066 and +4.8%, P = 0.036 respectively) with respect to baseline measures. Pulmonary dysfunction was reduced (-9%, P = 0.002) while 6-minute walking distance was longer (+16%, P = 0.029) at equal exertion fatigue level. CONCLUSIONS: The programme improved most pulmonary performance measures and had clinical significance. Its sustained application may prevent respiratory complications frequently observed in the later stages of multiple sclerosis.

The distribution of transglutaminase in the rat oocytes and embryos.

Transglutaminases (TGs) are calcium-dependent enzymes that catalyze the transamidation of glutamine residues of a protein substrate to form intermolecular isopeptide bonds. The zona pellucida (ZP) is an extracellular, glycoprotein matrix that surrounds the oocytes of all Eutherian mammals. We aimed to identify the immunoreactivity of tissue transglutaminase (tTG) and ultrastructural changes occuring in rat oocytes before and after fertilization. Female rats were stimulated to superovulate, then mated with males. Oocytes and embryos were collected and examined by immunohistochemistry and electron microscopy. Before fertilization, tTG was present only in the oolemma and the cortical cytoplasm. After fertilization, tTG reactivity increased in the ZP of the early zygote and the preimplantation embryos, but decreased in the cytoplasm and perivitelline space (PVS). After fertilization, the PVS ultrastructure became asymmetrical and large around the polar bodies with many cortical granule contents. In conclusion, tTG immunoreactivity was found to be spatially and temporarily heterogeneous in the rat oocytes and embryos, especially in the ZP.

Distribution of laminin, vimentin and desmin in the rat uterus during initial stages of implantation.

The aim of this study was to investigate the immunohistochemical distribution of laminin, vimentin and desmin during the implantation period in the rat since ECM remodelling and the expression of intermediate filaments (Ifs) is essential for successful decidualization and implantation. On day 4 of pregnancy, laminin was found in a few endometrial stromal cells (ESC), the basement membrane of the numerous endometrial blood vessels, in endometrial glands and as well as in the uterine epithelium. The localization of vimentin on day 4 of pregnancy was widespread in the ESC. However, desmin immunoreactivity was low in ESC on this day of pregnancy. On day 6 of pregnancy, laminin and vimentin were localized in the decidual area underlying luminal epithelium and around the implanting embryo. Additionally, desmin was found to be present densely in decidual cells of the anti-mesometrial region where implantation takes place. Finally, on day 8 of pregnancy, laminin was present in decidual and parietal endodermal cells, whereas vimentin was immunolocalized in primary and secondary decidual regions in the endometrium. In contrast, desmin was detected in some parts of the secondary decidual zone. In conclusion, these proteins could have crucial roles in decidualization and implantation.

Do contrast media (iomeprol, gadopentetate dimeglumine) deteriorate ischemia/reperfusion injury of the liver?

BACKGROUND: Hepatic microcirculation is a main determinant of reperfusion injury and graft quality in liver transplantation. One of the important diagnostic procedures to recognize reperfusion failure is contrast-enhanced computed tomography or magnetic resonance imaging. PURPOSE: To examine the additional effect of contrast media (iomeprol and gadopentetate dimeglumine) on hepatic microcirculation and hepatic cellular damage in the phase of early ischemia/reperfusion injury of the rat liver. MATERIAL AND METHODS: The partial warm ischemia-reperfusion injury model of rat liver was used. Microcirculation and leukocyte-endothelium interaction were measured by intravital microscopy. Hepatic cellular damage was indicated by liver enzyme activity in the sera. The evaluation parameters were measured at baseline and at 30, 60, and 90 min after reperfusion. The contrast media (iomeprol group, n = 6; gadopentetate dimeglumine group, n = 6) or Ringer's solution (control group, n = 8) were applied after 30 min of reperfusion. RESULTS: No additional injury to the ischemia/reperfusion injury of the liver after intravenous application of radiographic contrast media was found. Some protective effect was even recorded after application of iodinated contrast media. CONCLUSION: The use of contrast media during diagnostic procedure of the liver seems to be relatively safe, even in the stage of early reperfusion after liver transplantation.

Hofbauer cells in early human placenta: possible implications in vasculogenesis and angiogenesis.

The stroma of the placental villi contain numerous macrophages, so-called Hofbauer cells which are of mesenchymal origin and are thought to function in many processes. Although there are many studies concerning placental vasculogenesis and angiogenesis, there has been a lack of evidence on the possible roles of Hofbauer cells in these processes. In this study we hypothesized that Hofbauer cell locations and numbers might be correlated with the vascular structures within the placental villi core and therefore may be implicated to play roles in placental vasculogenesis and angiogenesis. Placental tissues were obtained from normal first-trimester pregnancies. Tissues were prepared for light microscopic investigations. Double immunohistochemistry staining with CD31/PECAM1 and CD68 was applied to placental tissues. In placental villous core, majority of the Hofbauer cells were found to be either in close contact with angiogenic cell cords and primitive vascular tubes or located in between them. Moreover, the number of Hofbauer cells and vasculogenic structures were found to be significantly correlated. The findings of this study suggest for the first time that Hofbauer cells might be involved in the processes of vasculogenesis and angiogenesis in the placenta.

Immunolocalizations of VEGF, its receptors flt-1, KDR and TGF-beta's in epithelial ovarian tumors.

OBJECTIVE: Angiogenesis is an essential factor for growth, differentiation, invasion and metastasis of tumors. In this study, we aimed to evaluate the immunolocalizations of vascular endothelial growth factor (VEGF), its receptors flt-1, KDR/flk-1, and transforming growth factor-beta's (TGF-beta) in epithelial ovarian tumors, utilizing indirect immunohistochemistry to understand the role of the angiogenic events in ovarian neoplasia. METHODS: Tissue blocks from 40 patients who had ovarian pathology (borderline serous-mucinous tumor and malignant serous-mucinous adenocarcinoma of the ovary) were included in this study. All formalin-fixed, paraffin-embedded tissue sections were stained with hematoxylin-eosin or primary antibodies against VEGF, flt-1, KDR/flk-1, TGF-beta1, TGF-beta2 and TGF-beta3 using the avidin-biotin-peroxidase method. H-SCORE, a semi-quantitative grading system, was used to compare immunohistochemical staining intensities. RESULTS: Positive VEGF immunoreactivity was concentrated in the epithelial and stromal parts of all the ovarian samples and the endothelial cells in the stroma were also stained. Increased immunoreactivity of VEGF was observed in malignant ovarian adenocarcinomas compared to the borderline tumors of the ovary. VEGF receptors, flt-1 and KDR/flk-1 immunoreactivities were detected not only in vascular endothelial cells, but also in tumor cells at malignant sites. Immunoreactivities of VEGF and its receptors were coexpressed in tumor cells of the ovarian carcinoma. While immunoreactivities of TGF-beta1 and TGF-beta2 were both overexpressed in malignant ovarian carcinomas, immunoreactivity of TGF-beta3 was still mild. CONCLUSION: Our results suggest that overexpression of VEGF, its receptors flt-1, KDR/flk-1 and TGF-beta interaction may play an important role in the ovarian cancer biology, with potential effects on tumor growth and angiogenesis. New therapeutic strategies using VEGF and TGF-beta antagonists could obtain an additional approach to the treatment ovarian carcinoma by inhibiting angiogenesis.

Spatial and temporal distribution of Tie-1 and Tie-2 during very early development of the human placenta.

Vasculogenesis in the human placenta comprises differentiation and growth of newly forming blood vessels derived from hemangiogenic stem cells within the mesenchymal core of villi. In a second stage, angiogenesis leads to the expansion and remodeling of the already existing vessels. At present, relatively little is known about the regulatory mechanisms of vasculogenesis and angiogenesis during very early placentation. Using placental villous tissues from days 22 to 48 of pregnancy, we analyzed the spatial and temporal expression of Tie-1 and Tie-2 in parallel to vascular maturation in the human placenta. In immunohistochemistry both receptors, Tie-1 and Tie-2 show a cell and villous type specific expression during this early phase of placental development. Especially, cytotrophoblast and hemangiogenic cell cords in mesenchymal villi and Hofbauer cells in immature intermediate villi have the strongest immunoreactivities. Western blot analysis showed that no significant changes were detected for Tie-1 and Tie-2 as pregnancy advanced. Moreover, phospho-Tie-2 levels did not change significantly in parallel to pregnancy ages. We conclude that both receptors are involved in angiogenesis as well as vascular modulation of early vessels. Due to their spatial distribution we speculate on an additional role in regulation of villous and extravillous trophoblastic behavior.

Sequential steps during vasculogenesis and angiogenesis in the very early human placenta.

Development of blood vessels takes place via two subsequent processes, vasculogenesis and angiogenesis. During vasculogenesis, formation of first blood vessels is achieved by differentiation of hemangiogenic stem cells from pluripotent mesenchymal cells, while during angiogenesis new blood vessels form from already existing vessels. The combination of our data with those from the literature leads us to depict the chronological steps of cell differentiation in the mesenchymal core of placental villi during vasculogenesis and angiogenesis. This current opinion will focus on the temporal and spatial expression of VEGF and its receptors VEGFR-1 and VEGFR-2, and the angiopoietin receptors Tie-1 and Tie-2 in parallel to vascular maturation in human placental villi during very early stages of placental development. There is evidence that the interplay of a variety of growth factors secreted from different cell types during development is needed to trigger as well as maintain placental vasculogenesis and angiogenesis.

Immunocytochemical detection of synaptophysin in enteric neurones during prenatal development in the rat stomach.

Summary In this study, the localization and appearance of synaptophysin-immunoreactive (IR) nerve cells and their relationships with the developing gastric layers were studied by immunocytochemistry and light microscopy in the embryonic rat stomach. The stomachs of Wistar rat embryos aged 13-21 days were used. The first neuronal bodies and their processes containing synaptophysin-immunoreactivity were observed on embryonic day 13. In contrast, synaptophysin-IR nerve terminals were first observed between mesenchymal cells on embryonic day 14. These results indicate that synaptophysin is expressed in growing neurits and neuronal cell bodies before these neurones have established synaptic connections. The occurrences of mesenchymal cell condensation near synaptophysin-IR neuroblasts on embryonic day 15 reflect an active nerve element-specific mesenchymal cell induction resulting in the morphogenesis of muscle cells. Similarly, the appearance of glandular structures after synaptophysin-IR neuroblasts, on embryonic day 18, suggests that the epithelial differentiation may be closely related to the neuronal maturation as well as other factors. Finally, synaptophysin is functionally important in neuronal development and maturation, together with the establishment of neuroneuronal and neuromuscular contacts and in epithelial differentiation.

Sequential expression of VEGF and its receptors in human placental villi during very early pregnancy: differences between placental vasculogenesis and angiogenesis.

Vascularization within the human placenta is the result of the de novo formation of vessels derived from pluripotent precursor cells in the mesenchymal core of the villi. Vascularization of placental villi starts at around day 21 post conception (p.c.) with a four somite embryo. At this stage progenitors of haemangiogenic cells differentiate to form first vessels. These progenitor cells are thought to be directly derived from mesenchymal cells rather than originating from fetal blood cells. We investigated the relation between differentiation of stromal cells towards endothelial cells and vascular structures and the expression pattern of the respective growth factors. Using transmission electron microscopy and immunohistochemistry (for VEGF, Flt-1, Flk-1, CD14, CD34, and CD68) the development of placental vasculogenesis during very early stages of pregnancy (days 22-48 p.c.) was studied. We found that VEGF is strongly expressed in villous cytotrophoblast cells and subsequently in Hofbauer cells while its receptors Flt-1 and Flk-1 are found on vasculogenic and angiogenic precursor cells. The developmental expression and secretion of VEGF suggests its involvement in recruitment, maintenance and formation of first angiogenic cells and vessels. Interactions between VEGF and Flk-1 and Flt-1 may regulate placental vasculogenesis and angiogenesis in a paracrine and autocrine manner. The sequential expression of growth factors in different cell types may point to the fact that placental vasculogenesis and angiogenesis are clearly distinct events.

The zonal distributions of alkaline phosphatase, adenosine triphosphatase, laminin, fibronectin and chondroitin 4-sulphate in growing rat humerus proximal epiphyseal cartilage: a histochemical and an immunohistochemical study.

Although there are many studies about epiphyseal cartilage extracellular matrix (ECM) macromolecules in bone formation, studies of their distribution and role in the mineralization of these components in growing rat humerus proximal epiphyseal cartilage have not been sufficiently detailed. The aim of this study was to determine the distributions of alkaline phosphatase (ALP), adenosine triphosphatase (ATPase), laminin, fibronectin and chondroitin 4-sulphate in growing rat humerus proximal epiphyseal cartilage. The rats were killed by cervical dislocation, and the humeri were removed, sectioned (6 and 10 microm) on a cryotome or paraffin microtome, and stained using histochemical and immunohistochemical methods. ALP and ATPase were markedly observed in the hypertrophy and calcifying cartilage. In addition, ATPase was found to be very strongly positive in the tangential zone of articular cartilage. Results of immunohistochemical staining for laminin, fibronectin and chondroitin 4-sulphate showed that the immunostaining was the heaviest in the tangential zone of articular cartilage. In growing epiphyseal plates, there were differences in the density of these macromolecules of chondrocytes as a function of the maturation process. In conclusion, these ECM macromolecules of epiphyseal cartilage may regulate the cell-cell and cell-matrix interactions as well as the matrix calcification during the ossification of epiphyseal cartilage.