Length Of Blood Vessels Research Articles

Regulation of vascular growth and tone by hydrogen sulfide

Hydrogen sulfide (H2S) is a colourless, flammable gas with a characteristic pungent smell. Until recently, the H2S literature was focused in the toxicology of this agent. Exposure to H2S concentrations lower than 100 ppm lead to eye irritation, sore throat, dizziness, nausea, shortness of breath, and chest tightness, while exposure to 1000 ppm or more causes central nervous system toxicity and respiratory depression. In the past 5 years the interest for H2S biology has seen an upsurge, as it was accepted that low amounts of this gas are endogenously produced in most mammalian tissues. Increasing evidence shows that H2S acts as a signalling molecule in cells and is now considered the third member of the gasotransmitter family along with nitric oxide and carbon monoxide. Most of H2S is produced by two enzymes cystathionine-synthase (CBS) and cystathionine γ-lyase (CSE) that use L-cysteine as a substrate and pyridoxal phosphate as a co-factor. CBS is highly expressed in the central nervous system, while CSE is abundantly present in the heart, lung, blood vessels, liver and kidney. In the cardiovascular system, H2S has anti-apoptotic effects on cardiomyocytes, exerts cardioprotective actions and modifies vascular tone. We have recently shown that exogenously administered Na2S stimulates endothelial proliferation, migration and capillary-like network formation. These effects of H2S on migration are mediated through the activation of ATP-sensitive K+-channels (KATP) and activation of mitogen activated protein kinase pathways. Inhibition of CSE and reduction of endogenously produced H2S reduces vascular network length and branching of blood vessels in the chicken chorioallantoic membrane. Exposure of endothelial cells to vascular endothelial growth factor (VEGF) increased H2S production and genetic or pharmacological inhibition of CSE restricted VEGF signalling and VEGF-driven angiogenic responses (migration, sprouting). Thus, H2S is an endogenous activator of angiogenesis and modulation of its production might be useful in diseases characterized by aberrant or excessive angiogenesis. H2S exerts important biological actions in vascular smooth muscle cells. Originally H2S–induced vasorelaxation was believed to be mediated by potassium channels (including KATP channels). However, significant vasodilation can be observed after sulfonylurea treatment, suggesting that additional pathways are involved. We recently showed that H2S donors inhibit phosphodiesterase activity in vitro and that exposure to H2S increases cGMP levels in smooth muscle cells. The cGMP elevating effects of H2S are abolished following phosphodiesterase inhibition. Moreover, incubation of cells with H2S led to an increase in VASP phopshorylation on Ser239, suggesting that H2S activates PKG signalling pathways. More importantly, incubation of aortic rings with selective PKG-I inhibitors (DT-2, DT-3) attenuated H2S-induced vasorelaxation. Our results reinforce the notion that H2S plays important roles in vascular biology, by modulating vascular growth and tone.

Visualisation and stereological assessment of blood and lymphatic vessels.

The physiological processes involved in tissue development and regeneration also include the parallel formation of blood and lymphatic vessel circulations which involves their growth, maturation and remodelling. Both vascular systems are also frequently involved in the development and progression of pathological conditions in tissues and organs. The blood vascular system circulates oxygenated blood and nutrients at appropriate physiological levels for tissue survival, and efficiently removes all waste products including carbon dioxide. This continuous network consists of the heart, aorta, arteries, arterioles, capillaries, post-capillary venules, venules, veins and vena cava. This system exists in an interstitial environment together with the lymphatic vascular system, including lymph nodes, which aids maintenance of body fluid balance and immune surveillance. To understand the process of vascular development, vascular network stability, remodelling and/or regression in any research model under any experimental conditions, it is necessary to clearly and unequivocally identify and quantify all elements of the vascular network. By utilising stereological methods in combination with cellular markers for different vascular cell components, it is possible to estimate parameters such as surface density and surface area of blood vessels, length density and length of blood vessels as well as absolute vascular volume. This review examines the current strategies used to visualise blood vessels and lymphatic vessels in two- and three-dimensions and the basic principles of vascular stereology used to quantify vascular network parameters.

Photodynamic Therapy With Verteporfin Combined With Subconjunctival Injection of Bevacizumab for Corneal Neovascularization

To investigate the efficacy of combined photodynamic therapy with verteporfin and subconjunctival injection of bevacizumab for the treatment of patients with corneal neovascularization. Twelve eyes of 12 patients with stable corneal neovascularization who were refractory to conventional treatment were treated with photodynamic therapy with verteporfin (6 mg/m) and subconjunctival injection of bevacizumab (2.5 mg/0.1 mL). Anterior segment photography was performed before and after treatment. Best-corrected visual acuity, cumulative length of corneal blood vessels, and area of corneal neovascularization were measured. From 1 week to 1 month after treatment, all eyes showed a notable decrease in corneal neovascularization and evidence of vascular thrombosis. At the 6-month and 1-year follow-ups, complete vascular occlusion was achieved in 8 eyes (66.7%) and partial occlusion was achieved in 3 eyes (25.0%). One eye (8.3%) showed revascularization after temporary occlusion. No ocular complications or systemic events developed. Photodynamic therapy with verteporfin combined with subconjunctival injection of bevacizumab seems to be effective for the treatment of corneal neovascularization.

Morphine Suppresses Tumor Angiogenesis through a HIF-1α/p38MAPK Pathway

Morphine, a highly potent analgesic agent, is frequently prescribed for moderate to severe cancer pain. In this study, morphine was administered at a clinically relevant analgesic dose to assess tumor cell-induced angiogenesis and subcutaneous tumor growth in nude mice using mouse Lewis lung carcinoma cells (LLCs). Implantation of mice with a continuous slow-release morphine pellet achieved morphine plasma levels within 250-400 ng/ml (measured using a radioimmunoassay, Coat-A-Count Serum Morphine) and was sufficient to significantly reduce tumor cell-induced angiogenesis and tumor growth when compared with placebo treatment. Morphometric analysis for blood vessel formation further confirmed that morphine significantly reduced blood vessel density (P < 0.003), vessel branching (P < 0.05), and vessel length (P < 0.002) when compared with placebo treatment. Morphine's effect was abolished in mice coadministered the classical opioid receptor antagonist, naltrexone, and in mu-opioid receptor knockout mice, supporting the involvement of the classical opioid receptors in vivo. Morphine's inhibitory effect is mediated through the suppression of the hypoxia-induced mitochondrial p38 mitogen-activated protein kinase (MAPK) pathway. Our results suggest that in vitro morphine treatment of LLCs inhibits the hypoxia-induced nuclear translocation of hypoxia-inducible transcription factor 1alpha to reduce vascular endothelial growth factor transcription and secretion, in a manner similar to pharmacological blockade with the p38 MAPK-specific inhibitor, SB203585. These studies indicate that morphine, in addition to its analgesic function, may be exploited for its antiangiogenic potential.

French Maritime Pine Bark (Pinus maritima Lam.) Extract (Flavangenol®) Prevents Chronic UVB Radiation‐induced Skin Damage and Carcinogenesis in Melanin‐possessing Hairless Mice

A French maritime pine bark extract, Flavangenol, is widely used as a nutritional supplement for protection against atherosclerosis, hypertension, diabetes, etc. Chronic exposure to solar UV radiation damages skin, increasing cutaneous thickness, wrinkling and pigmentation, as well as reducing elasticity, and causes skin cancer. The aim of this study was to examine the effects of flavangenol on skin damage and the incidence of skin tumors caused by long-term UVB irradiation in melanin-possessing hairless mice. The oral administration of flavangenol (60, 200 or 600 mg kg(-1), twice daily) significantly inhibited increases in skin thickness, and the formation of wrinkles and melanin granules, as well as increases in the diameter and length of skin blood vessels. Furthermore, it prevented increases in numbers of apoptotic, Ki-67-positive and 8-hydroxy-2'-deoxyguanosine (8-OHdG)-positive cells, and the expression of skin vascular endothelial growth factor (VEGF) induced by chronic UVB irradiation. The effect on these biomarkers was associated with a reduction in the incidence of tumors in mice. The antiphotoaging and anticarcinogenetic activities of flavangenol may be due to inhibition of the expression of Ki-67, 8-OHdG and VEGF through a scavenging effect on reactive oxygen species.

Abstract 1294: Inhibition of angiogenesis in lymph node metastasis

Abstract Cancer invasion of the lymphatic system and spread to draining lymph nodes is a common occurrence and is often a first step of the metastatic pathway. Suppression of tumor angiogenesis in the lymph node should inhibit cancer growth and further spread from the lymph node. In the present study, we evaluated angiogenesis inhibitors in lymph node metastasis using GFP imaging. Transgenic nude mice expressing GFP under the control of the nestin promoter (ND-GFP mice) were used as hosts. Nascent blood vessels express GFP in these mice (Cancer Res. 65, 5352-5357, 2005). B16F10-RFP mouse melanoma cells were injected into the efferent lymph vessel of the inguinal lymph node of the transgenic ND-GFP nude mice to establish experimental metastasis in the axillary lymph node. The mice were given daily i.p. injections of doxorubicin or vehicle controls at days 0, 1, and 2 after implantation of tumor cells. The axillary lymph nodes of the mice were observed at day 8 after injection of tumor cells. Angiogenesis was quantified in the tumor-involved lymph node by measuring the total length of ND-GFP nascent blood vessels. The number of ND-GFP-expressing blood vessels in the tumor-involved lymph nodes was significantly less in the doxorubicin-treated animals than in vehicle control mice. Treatment with doxorubicin significantly decreased the volume of the metastatic axillary-node tumor as well as nascent blood vessel formation. These results show the utility of the dual-color ND-GFP-mouse and RFP-cancer-cell model to visualize and quantitate angiogenesis in tumor-involved lymph nodes and to screen for angiogenesis inhibitors at this site. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 1294.

Urokinase-type plasminogen activator regulates neurodegeneration and neurogenesis but not vascular changes in the mouse hippocampus after status epilepticus

Expression of urokinase-type plasminogen activator (uPA) is increased after brain injury, suggesting that, like in cancer tissue, uPA plays roles in brain remodeling. Here we injured brain with intrahippocampal kainic acid (KA) injection in adult Wt and uPA−/− mice. At 20 days post-injury, uPA−/− mice had more severe loss of contralateral pyramidal ( p < 0.05) and hilar neurons ( p < 0.05) than Wt mice. The number of doublecortin (DCX)-positive newly born neurons was also reduced in uPA−/− mice as compared to Wt ( p < 0.01). No difference was observed in granule cell dispersion or distribution of DCX-positive neurons in the dentate gyrus. uPA deficiency did not affect the total length of hippocampal blood vessels or vessel density. No differences were observed in the severity of status epilepticus or consequent epilepsy between the genotypes. These data indicate that uPA deficiency can unfavorably modulate both delayed neurodegeneration and neurogenesis but has little effect on post-injury neuronal migration and vascular density. Our results favor the idea that elevated uPA during the post-injury phase is neuroprotective.

Vascular changes in epilepsy: functional consequences and association with network plasticity in pilocarpine-induced experimental epilepsy

Angiogenesis and blood-brain-barrier (BBB) damage have been proposed to contribute to epileptogenesis and/or ictogenesis in experimental and human epilepsy. We tested a hypothesis that after brain injury angiogenesis occurs in the most damaged hippocampal areas with the highest need of tissue repair, and associates with formation of epileptogenic neuronal networks. We induced status epilepticus (SE) with pilocarpine in adult rats, and investigated endothelial cell proliferation (BrdU and rat endothelial cell antigen-1 (RECA-1) double-labeling), vessel length (unbiased stereology), thrombocyte aggregation (thrombocyte immunostaining), neurodegeneration (Nissl staining), neurogenesis (doublecortin (DCX) immunohistochemistry), and mossy fiber sprouting (Timm staining) in the hippocampus at different time points post-SE. As functional measures we determined BBB leakage (quantified immunoglobulin G (IgG) immunostaining), and hippocampal blood volume (CBV) and flow (CBF) in vivo (magnetic resonance imaging, MRI). The total length of hippocampal blood vessels was decreased by 17% at 2 d after status epilepticus (SE) induced by pilocarpine in adult rats ( P<0.05 as compared to controls) which was not accompanied by alterations in hippocampal blood volume (BV) and flow (BF). Number of proliferating endothelial cells peaked at 4 d post-SE and correlated with an increase in vessel length ( r=0.900, P<0.05). Vessels length had recovered to control level or even higher at 2 wk post-SE, angiogenesis being most prominent in the CA3 (128% as compared to that in controls, P<0.05), and was associated with increased BV (178% as compared to that in controls, P<0.05). Enlargement of vessel diameter in the hippocampal fissure was associated with thrombocyte aggregation in distal capillaries. BBB was most leaky during the first 4 d post-SE and increased IgG extravasation was observed for 60 d. Our data show that magnitude of endothelial cell proliferation is not associated with severity of acute post-SE neurodegeneration or formation of abnormal neuronal network. This encourages identification of molecular targets that initiate and maintain specific aspects of tissue reorganization, including preservation and proliferation of endothelial cells to reduce the risk of epileptogenesis and enhance recovery after brain injury.

Application of stereology to dermatological research

Stereology is a set of mathematical and statistical tools to estimate three-dimensional (3-D) characteristics of objects from regular two-dimensional (2-D) sections. In medicine and biology, it can be used to estimate features such as cell volume, cell membrane surface area, total length of blood vessels per volume tissue and total number of cells. The unbiased quantification of these 3-D features allows for a better understanding of morphology in vivo compared with 2-D methods. This review provides an introduction to the field of stereology with specific emphasis on the application of stereology to dermatological research by supplying a short insight into the theoretical basis behind the technique and presenting previous dermatological studies in which stereology was an integral part. Both the theory supporting stereology and a practical approach in a dermatological setting are reviewed with the aim to provide the reader with the capability to better assess papers employing stereological estimators and to design stereological studies independently.

Discrete Contributions of Elastic Fiber Components to Arterial Development and Mechanical Compliance

Even though elastin and fibrillin-1 are the major structural components of elastic fibers, mutations in elastin and fibrillin-1 lead to narrowing of large arteries in supravalvular aortic stenosis and dilation of the ascending aorta in Marfan syndrome, respectively. A genetic approach was therefore used here to distinguish the differential contributions of elastin and fibrillin-1 to arterial development and compliance. Key parameters of cardiovascular function were compared among adult mice haploinsufficient for elastin (Eln(+/-)), fibrillin-1 (Fbn1(+/-)), or both proteins (dHet). Physiological and morphological comparisons correlate elastin haploinsufficiency with increased blood pressure and vessel length and tortuosity in dHet mice, and fibrillin-1 haploinsufficiency with increased aortic diameter in the same mutant animals. Mechanical tests confirm that elastin and fibrillin-1 impart elastic recoil and tensile strength to the aortic wall, respectively. Additional ex vivo analyses demonstrate additive and overlapping contributions of elastin and fibrillin-1 to the material properties of vascular tissues. Lastly, light and electron microscopy evidence implicates fibrillin-1 in the hypertension-promoted remodeling of the elastin-deficient aorta. These results demonstrate that elastin and fibrillin-1 have both differential and complementary roles in arterial wall formation and function, and advance our knowledge of the structural determinants of vascular physiology and disease.

External magnet improves antitumor effect of vinblastine and the suppression of metastasis

The use of magnetic drug targeting (MDT) to selectively deliver chemotherapeutic drugs to tumor cells is a widely investigated approach; however, the notion of targeting tumor endothelial cells by this method is a fairly new concept. Positively-charged (cationic) liposomes have an extraordinarily high affinity for tumor vessels, but heterogeneous targeting is frequently observed. In order to improve on the overall efficiency of targeting tumor vessels, we investigated the use of an externally applied magnetic field together with magnetic cationic liposomes (MCLs) for cancer treatment. We examined the antitumor effect of the chemotherapeutic agent vinblastine loaded in MCLs, using a murine model of melanoma. Two hours following i.v. administration of MCLs, we observed significant tumor vascular uptake with use of an external magnet (15.9 +/- 6.3%) compared to no magnet (5 +/- 1.3%). The administration of vinblastine-loaded MCLs with the magnet produced a significant antitumor effect, reducing the presence of tumor nodules in preferential sites of metastasis compared to untreated and free drug control groups. CD31 immunostaining revealed a decrease in the general length of tumor blood vessels, altered vascular morphology and interruptions in the tumor vascular lining for the vinblastine-loaded MCL groups. Drug-loaded MCLs with magnetic fields may represent a promising combination approach for cancer treatment.

Effects of a turmeric extract (Curcuma longa) on chronic ultraviolet B irradiation-induced skin damage in melanin-possessing hairless mice

Turmeric (the rhizomes of Curcuma longa L., Zingiberacease) is widely used as a dietary pigment and spice, and has been traditionally used for the treatment of inflammation, skin wounds and hepatic disorders in Ayurvedic, Unani and Chinese medicine. Although the topical application or oral administration of turmeric is used to improve skin trouble, there is no evidence to support this effect. The aim of this study was to clarify whether turmeric prevents chronic ultraviolet B (UVB)-irradiated skin damage. We examined the effects of a turmeric extract on skin damage including changes in skin thickness and elasticity, pigmentation and wrinkling caused by long-term, low-dose ultraviolet B irradiation in melanin-possessing hairless mice. The extract (at 300 or 1000 mg/kg, twice daily) prevented an increase in skin thickness and a reduction in skin elasticity induced by chronic UVB exposure. It also prevented the formation of wrinkles and melanin (at 1000 mg/kg, twice daily) as well as increases in the diameter and length of skin blood vessels and in the expression of matrix metalloproteinase-2 (MMP-2). Prevention of UVB-induced skin aging by turmeric may be due to the inhibition of increases in MMP-2 expression caused by chronic irradiation.

Effects of the nonsugar fraction of brown sugar on chronic ultraviolet B irradiation-induced photoaging in melanin-possessing hairless mice

Brown sugar has been used traditionally for the treatment of skin trouble as a component of soaps or lotions. Symptoms of aging including wrinkles and pigmentation develop earlier in sun-exposed skin than unexposed skin, a phenomenon referred to as photoaging. Ultraviolet B (UVB) radiation is one of the most important environmental factors influencing photoaging. The aim of this study was to clarify whether the nonsugar fraction of brown sugar prevents chronic UVB-induced aging of the skin using melanin-possessing hairless mice. The nonsugar fraction (1% or 3% solution, 50 mul/mouse) was applied topically to the dorsal region every day for 19 weeks. Both solutions prevented an increase in skin thickness and reduction in skin elasticity caused by the UVB. The 3% solution also prevented wrinkles and melanin pigmentation as well as increases in the diameter and length of skin blood vessels. Increases in the expression of matrix metalloproteinase-2 (MMP-2) and vascular endothelial growth factor (VEGF) in UVB-irradiated skin was inhibited by the nonsugar fraction. Prevention of UVB-induced aging of the skin by topical application of the nonsugar fraction of brown sugar may be due to inhibition of increases in MMP-2 and VEGF expression.

Delayed Peripheral Administration of a GPE Analogue Induces Astrogliosis and Angiogenesis and Reduces Inflammation and Brain Injury following Hypoxia-Ischemia in the Neonatal Rat

Glycine 2-methyl proline glutamate (G-2mPE) is a proline-modified analogue to the naturally existing N-terminal tripeptide glycine-proline-glutamate that is a cleaved product from insulin-like growth factor-1. G-2mPE is designed to be more enzymatically resistant than glycine-proline-glutamate and to increase its bioavailability. The current study has investigated the protective effects of G-2mPE following hypoxic-ischemic brain injury in the neonatal brain. On postnatal day 7, Wistar rats were exposed to hypoxia-ischemia (HI). HI was induced by unilateral ligation of the left carotid artery followed by hypoxia (7.7% O₂, 36°C) for 60 min. The drug treatment started 2 h after the insult, and the pups were given either 1.2 mg/kg (bolus), 1.2 mg/ml once a day for 7 days, or vehicle. The degree of brain damage was determined histochemically by thionin/acid fuchsin staining. G-2mPE’s anti-inflammatory properties were investigated by IL-1β, IL-6, and IL-18 ELISA, and effects on apoptosis by caspase 3 activity. Vascularization was determined immunohistochemically by the total length of isolectin-positive blood vessels. Effect on astrocytosis was also determined in the hippocampus. Animals treated with multiple doses of G-2mPE demonstrated reduced overall brain injury 7 days after HI, particularly in the hippocampus and thalamus compared to vehicle-treated rats. The expression of IL-6 was decreased in G-2mPE-treated animals compared to vehicle-treated pups, and both the capillary length and astrogliosis were increased in the drug-treated animals. There was no effect on caspase 3 activity. This study indicates that peripheral administration of G-2mPE, starting 2 h after a hypoxic-ischemic insult, reduces the degree of brain injury in the immature rat brain. The normalization of IL-6 levels and the promotion of both neovascularization and reactive astrocytosis may be potential mechanisms that underlie its protective effects.

An experimental study of anti-angiogenesis with polyethylene glycol endostatin

目的 观察聚乙二醇化内皮抑素(PEG-endostatin)抑制碱烧伤诱导的兔角膜新生血管(CNV)的效果,探讨其作用机制.方法 采用碱烧伤法诱导兔角膜新生血管形成.在碱烧伤后1d,治疗1、2组和对照组分别在球结膜下注射50μg/mL PEG化内皮抑素、50μg/mL重组内皮抑素、生理盐水各0.2mL.以后隔日注射1次,共8次.动态观察CNV的生长状况.利用免疫组化方法检测血管内皮生长因子(VEGF)的表达,并在显微镜下进行微血管计数.结果 治疗1、2组CNV的长度和面积、VEGF的表达及微血管数量均明显少于生理盐水对照组(P＜0.05);而治疗1组的CNV的长度和面积、VEGF的表达及微血管数量均明显少于治疗2组(P＜0.05).结论 PEG化内皮抑素及重组内皮抑素都可有效抑制CNV的生长,但前者效果更好。

CLINICAL ANATOMICAL STUDY OF PEDICLED VASCULARISED SCAPULAR BONE GRAFT USING THE ANGULAR BRANCH

This study is an anatomical investigation of the angular branch of thoracodorsal artery, and examines the possible range of clinical targets for pedicled vascularised scapular bone graft. Forty-six cadavers were studied. The blood vessel length was calculated, and the distance required to reach the distal humerus from the lower end of the articular surface of the humeral head as reference point was compared with bone length. The length from reference point was an average of 121.7 mm. It was thought that the maximum distance to arrive in reference point to the distal humerus was a total of blood vessel length and transplantation bone length, which was an average of 246.3 mm. This was longer than the average of 240.8 mm of bone length from reference point to humeral medial condyle. This study had confirmed that a pedicled vascularised scapular bone graft using the angular branch could be transplanted to the distal humerus.

Endothelial Proliferation and Increased Blood–Brain Barrier Permeability in the Basal Ganglia in a Rat Model of 3,4-Dihydroxyphenyl-l-Alanine-Induced Dyskinesia

3,4-Dihydroxyphenyl-L-alanine (L-DOPA)-induced dyskinesia is associated with molecular and synaptic plasticity in the basal ganglia, but the occurrence of structural remodeling through cell genesis has not been explored. In this study, rats with 6-hydroxydopamine lesions received injections of the thymidine analog 5-bromo-2'-deoxyuridine (BrdU) concomitantly with L-DOPA for 2 weeks. A large number of BrdU-positive cells were found in the striatum and its output structures (globus pallidus, entopeduncular nucleus, and substantia nigra pars reticulata) in L-DOPA-treated rats that had developed dyskinesia. The vast majority (60-80%) of the newborn cells stained positively for endothelial markers. This endothelial proliferation was associated with an upregulation of immature endothelial markers (nestin) and a downregulation of endothelial barrier antigen on blood vessel walls. In addition, dyskinetic rats exhibited a significant increase in total blood vessel length and a visible extravasation of serum albumin in the two structures in which endothelial proliferation was most pronounced (substantia nigra pars reticulata and entopeduncular nucleus). The present study provides the first evidence of angiogenesis and blood-brain barrier dysfunction in an experimental model of L-DOPA-induced dyskinesia. These microvascular changes are likely to affect the kinetics of L-DOPA entry into the brain, favoring the occurrence of motor complications.

Effect of Gestational Nutrition on Vascular Integrity in the Murine Placenta

Maternal undernutrition is thought to result in smaller offspring and programme disease in later life. It is not known whether gestational nutrition affects development and functioning of placental vessels. The aim of this study was to ascertain if disturbed angiogenesis and junctional integrity were features of the labyrinthine vessels of placenta taken from transgenic Tie2-GFP mice fed either 18% (control) or 9% (low protein; MLP) casein diet.MLP animals showed a significant decrease in fetal weight at E14.5 and in placental and fetal weight at E18.5, however, maternal weight and litter size remained unaffected. Stereological analyses revealed that the fraction of components of the placenta remained similar in both study groups. There was a significant reduction in labyrinthine blood vessel length but not in luminal diameter in the E18.5 MLP group. In both MLP groups, perturbation of vascular endothelial Cadherin and β-catenin, regulators of junctional integrity, permeability and quiescence, was observed with higher percentage of vessels showing weak or no junctional immunoreactivity. The reduction in length of the labyrinthine vessels and the downregulation of the adhesion molecules suggest that gestational undernutrition causes vascular dysfunction in the murine placenta. This may play a role in the early life programming of disease risk.

Preliminary Report on Analysis of Bladder-Wall Vasculature Using Conjunctival Microvascular Analysis in Patients with and without Transitional-Cell Carcinoma

To develop a technique to analyze the bladder microvasculature during cystoscopy to assess the conjuctival microvascular morphology at the capillary level. This technique could be an adjunct to visual examination of the bladder during cystoscopy for diseases that are presumed to affect the vasculature. Subjects with transitional-cell carcinoma (TCC) were chosen because of their frequency of cystoscopy. A total of 12 male patients, ages 45 to 80 years, underwent cystoscopy: four without TCC and eight with TCC by bladder biopsy. The images were digitally recorded and enhanced using a custom image-analysis system. The blood vessel length (VL) and diameter (VD) and blood vessel volume (BVV) were measured. The VD was significantly greater in TCC than in non-TCC patients only in the lower-order vessels. The VL was significantly longer in TCC than in non-TCC, again in the lower-order vessels. In the higherorder vessels, the VL was significantly shorter in TCC than in non-TCC. The BVV in the lower-order vessels was significantly greater in TCC than in non-TCC patients. Differences exist in the morphology of surface microvessels between TCC and non-TCC bladders. Using the current technique, capillaries (VD < 10 microm) are not visible, so refinement of imaging and recording technologies is required to measure capillaries in order to simulate microvascular morphometry in the conjuctiva.

Regional and developmental variations of blood vessel morphometry in the chick embryo chorioallantoic membrane

Avian eggs contain all the necessary materials for embryonic development except for oxygen, which diffuses in from the environment via pores in the hard, calcified eggshell to the chorioallantoic membrane (CAM), the respiratory organ, which is rich in blood vessels. An air cell is formed at the blunt pole of the egg between the two membranes of the eggshell and enlarges during incubation due to water vapor loss. In this study of the CAM of chicken eggs, we compared blood vessel numerical density [N(A(v))], area fraction of blood vessels [A(A(v))], CAM thickness (D(CAM)), total length of blood vessels (L) and surface area of the CAM attached to the eggshell (CAMre) with those under the air cell (CAMac) during incubation. We found that N(A(v)), A(A(v)), D(CAM) and L of the CAM increase with embryonic age and development. The N(A(v)), A(A(v)) and L under the air cell were higher in relation to the rest of the CAM at all ages tested, while the D(CAM) under the air cell was always lower than around the rest of the egg. Since the eggshell over the air cell has a relatively greater porosity, and the respiratory gas exchange ratio there is higher than at other areas of the egg, there is a correlation between all the above morphometric data and the eggshell porosity. This suggests optimization of embryonic gas exchange in the chicken egg. We would like to propose that, during natural incubation, an increased gas diffusion under the air cell, together with increased blood vessel numerical density, may compensate for covering of the central part of the eggshell by the incubating parent.