Meningeal lymphatic vessel crosstalk with central nervous system immune cells in aging and neurodegenerative diseases

Meningeal lymphatic vessels form a relationship between the nervous system and periphery, which is relevant in both health and disease. Meningeal lymphatic vessels not only play a key role in the drainage of brain metabolites but also contribute to antigen delivery and immune cell activation. The advent of novel genomic technologies has enabled rapid progress in the characterization of myeloid and lymphoid cells and their interactions with meningeal lymphatic vessels within the central nervous system. In this review, we provide an overview of the multifaceted roles of meningeal lymphatic vessels within the context of the central nervous system immune network, highlighting recent discoveries on the immunological niche provided by meningeal lymphatic vessels. Furthermore, we delve into the mechanisms of crosstalk between meningeal lymphatic vessels and immune cells in the central nervous system under both homeostatic conditions and neurodegenerative diseases, discussing how these interactions shape the pathological outcomes. Regulation of meningeal lymphatic vessel function and structure can influence lymphatic drainage, cerebrospinal fluid-borne immune modulators, and immune cell populations in aging and neurodegenerative disorders, thereby playing a key role in shaping meningeal and brain parenchyma immunity.

Quantifying peripapillary vessel density and retinal nerve fibre layer in type 1 diabetic children without clinically detectable retinopathy using OCTA

AIM:To quantify changes in radial peripapillary capillary vessel density(ppVD)and the peripapillary retinal nerve fiber layer(pRNFL)in children with type 1 diabetes without clinical diabetic retinopathy by optical coherence tomography angiography(OCTA),providing a basis for early retinopathy in children with type 1 diabetes.METHODS:This was a retrospective study.A total of 30 patients(3–14y)with type 1 diabetes without clinical diabetic retinopathy(NDR group)were included.A total of 30 age-matched healthy subjects were included as the normal control group(CON group).The HbA1c level in the last 3mo was measured once in the NDR group.The pRNFL thickness and ppVD were automatically measured,and the mean pRNFL and ppVD were calculated in the nasal,inferior,temporal,and superior quadrants.The changes in ppVD and pRNFL in the two groups were analyzed.RESULTS:Compared with CON group,the nasal and superior ppVDs decreased in the NDR group(all P<0.01).The thickness of the nasal pRNFL decreased significantly(P<0.01),while the inferior,temporal and superior pRNFLs slightly decreased but not significant in the NDR group(all P>0.05).Person and Spearman correlation analysis of ppVD and pRNFL thickness in each quadrant of the NDR group showed a positive correlation between nasal and superior(all P<0.01),while inferior and temporal had no significant correlation(all P>0.05).There was no significant correlation between the HbA1c level and ppVD and pRNFL in any quadrant(all P>0.05).There was no significant correlation between the course of diabetes mellitus and ppVD and pRNFL in any quadrant(all P>0.05).CONCLUSION:ppVD and pRNFL decrease in eyes of children with type 1 diabetes before clinically detectable retinopathy and OCTA is helpful for early monitoring.

Repeatability,interocular correlation and agreement of optic nerve head vessel density in healthy eyes:a sweptsource optical coherence tomographic angiography study

AIM:To assess the repeatability,interocular correlation,and agreement of quantitative swept-source optical coherence tomography angiography(OCTA)optic nerve head(ONH)parameters in healthy subjects.METHODS:Thir ty-three healthy subjects were enrolled.The ONH of both eyes were imaged four times by a swept-source-OCTA using a 3 mm×3 mm scanning protocol.Images of the radial peripapillary capillary were analyzed by a customized Matlab program,and the vessel density,fractal dimension,and vessel diameter index were measured.The repeatability of the four scans was determined by the intraclass correlation coefficient(ICC).The most well-centered optic disc from the four repeated scans was then selected for the interocular correlation and agreement analysis using the Pearson correlation coefficient,ICC and Bland-Altman plots.RESULTS:All swept-source-OCTA ONH parameters exhibited certain repeatability,with ICC>0.760 and coefficient of variation(CoV)≤7.301%.The obvious interocular correlation was observed for papillary vessel density(ICC=0.857),vessel diameter index(ICC=0.857)and fractal dimension(ICC=0.906),while circumpapillary vessel density exhibited moderate interocular correlation(ICC=0.687).Bland-Altman plots revealed an agreement range of-5.26%to 6.21%for circumpapillary vessel density.CONCLUSION:OCTA ONH parameters demonstrate good repeatability in healthy subjects.The interocular correlations of papillary vessel density,fractal dimension and vessel diameter index are high,but the correlation for circumpapillary vessel density is moderate.

Functional aspects of the brain lymphatic drainage system in aging and neurodegenerative diseases

The phenomenon of an aging population is advancing at a precipitous rate.Alzheimer's disease(AD)and Parkinson's disease(PD)are two of the most common age-associated neurodegenerative diseases,both of which are primarily characterized by the accumulation of toxic proteins and the progressive demise of neuronal structures.Recent discoveries about the brain lymphatic drainage system have precipitated a growing body of investigations substantiating its novel roles,including the clearance of macromolecular waste and the trafficking of immune cells.Notably,aquaporin 4-mediated glymphatic transport,crucial for maintaining neural homeostasis,becomes disrupted during the aging process and is further compromised in the pathogenesis of AD and PD.Functional meningeal lymphatic vessels,which facilitate the drainage of cerebrospinal fluid into the deep cervical lymph nodes,are integral in bridging the central nervous system with peripheral immune responses.Dysfunction in these meningeal lymphatic vessels exacerbates pathological trajectory of the age-related neurodegenerative disease.This review explores modulatory influence of the glymphatic system and meningeal lymphatic vessels on the aging brain and its associated neurodegenerative disorders.It also encapsulates the insights of potential mechanisms and prospects of the targeted non-pharmacological interventions.

Structural measurements and vessel density of spectraldomain optic coherence tomography in early,moderate,and severe primary angle-closure glaucoma

AIM:To compare the macular ganglion cell-inner plexiform layer(GCIPL)thickness,retinal nerve fiber layer(RNFL)thickness,optic nerve head(ONH)parameters,and retinal vessel density(VD)measured by spectral-domain optical coherence tomography(SD-OCT)and analyze the correlations between them in the early,moderate,severe primary angle-closure glaucoma(PACG)and normal eyes.METHODS:Totally 70 PACG eyes and 20 normal eyes were recruited for this retrospective analysis.PACG eyes were further separated into early,moderate,or severe PACG eyes using the Enhanced Glaucoma Staging System(GSS2).The GCIPL thickness,RNFL thickness,ONH parameters,and retinal VD were measured by SD-OCT,differences among the groups and correlations within the same group were calculated.RESULTS:The inferior and superotemporal sectors of the GCIPL thickness,rim area of ONH,average and inferior sector of the retinal VD were significantly reduced(all P<0.05)in the early PACG eyes compared to the normal and the optic disc area,cup to disc ratio(C/D),and cup volume were significantly higher(all P<0.05);but the RNFL was not significant changes in early and moderate PACG.In severe group,the GCIPL and RNFL thickness were obvious thinning with retinal VD were decreasing as well as C/D and cup volume increasing than other three groups(all P<0.01).In the early PACG subgroup,there were significant positive correlations between retinal VD and GCIPL thickness(except superonasal and inferonasal sectors,r=0.573 to 0.641,all P<0.05),superior sectors of RNFL thickness(r=0.055,P=0.049).More obvious significant positive correlations were existed in moderate PACG eyes between retinal VD and superior sectors of RNFL thickness(r=0.650,P=0.022),and temporal sectors of RNFL thickness(r=0.740,P=0.006).In the severe PACG eyes,neither GCIPL nor RNFL thickness was associated with retinal VD.CONCLUSION:The ONH damage and retinal VD loss appears earlier than RNFL thickness loss in PACG eyes.As the PACG disease progressed from the early to the moderate stage,the correlations between the retinal VD and RNFL thickness increases.

Relationship between peritumoral lymphatic microvessel density and the clinical and pathological characteristics of invasive breast cancer

Objective The aim of the study was to determine the morphological characteristics of lymphatic microvessels and the relationship between lymphatic microvessel density(LMVD) and clinical and pathological characteristics of invasive breast cancer.Methods Tissue specimens and clinical pathological data of 51 cases of female breast cancer were collected in the General Hospital of Shenyang Military Region(Shenyang, China) from January 2007 to October 2011. Another 20 breast fibroadenoma tissue samples were used as controls. All specimens were cut into 4-μm slices, and immunohistochemically stained using streptomycin-resistant avidin peroxidase antibody D2-40. SPSS 17.0 for Windows was used to perform all analyses.Results A total of 38 breast cancer tissue specimens showed varied staining with monoclonal antibody D2-40. The rate of positive staining was in these tissues was 74.5%(38/51), which is significantly higher than that observed in breast fibroadenoma tissues(chi-square = 35.197, P = 0.000). The average LMVD in 38 cases of breast cancer was(26.46 ± 10.06) microvessels/100× magnification field, which was higher than that in the control group(t = 10.74, P = 0.000). Microvessels in peritumoral tissues were abundant, with an average LMVD of(38.42 ± 11.38) microvessels/100× magnification field. Based on layered analysis, the expression level of peritumoral LMVD was correlated with metastasis of lymph nodes, tumor size, and the expression of C-erb B-2(P < 0.05); however, there was no correlation with age or expression of estrogen receptors or progesterone receptors(P > 0.05).Conclusion Lymphatic microvessels detected using D2-40 antibody are mainly present in the peritumoral region of breast cancer tissues, and LMVD showed a correlation with lymph node metastasis and the expression of C-erb B-2. Positive lymphatic vessels, especially in the peritumoral region, may provide a path for lymphatic metastasis in breast cancer. Peritumoral LMVD may be used to estimate the prognosis of patients with breast cancer and may aid in research on treatment methods.

The lymphatic drainage systems in the brain:a novel target for ischemic stroke?

Recent studies have proposed three lymphatic drainage systems in the brain,that is,the glymphatic system,the intramural periarterial drainage pathway,and meningeal lymphatic vessels,whose roles in various neurological diseases have been widely explored.The glymphatic system is a fluid drainage and waste clearance pathway that utilizes perivascular space and aquaporin-4 protein located in the astrocyte endfeet to provide a space for exchange of cerebrospinal fluid and interstitial fluid.The intramural periarterial drainage pathway drives the flow of interstitial fluid through the capillary basement membrane and the arterial tunica media.Meningeal lymphatic vessels within the dura mater are involved in the removal of cerebral macromolecules and immune responses.After ischemic stroke,impairment of these systems could lead to cerebral edema,accumulation of toxic factors,and activation of neuroinflammation,while restoration of their normal functions can improve neurological outcomes.In this review,we summarize the basic concepts of these drainage systems,including drainage routes,physiological functions,regulatory mechanisms,and detection technologies.We also focus on the roles of lymphatic drainage systems in brain injury after ischemic stroke,as well as recent advances in therapeutic strategies targeting these drainage systems.These findings provide information for potential novel strategies for treatment of stroke.

Perimuscular connective tissue contains more and larger lymphatic vessels than the shallower layers in human gallbladders

AIM： To clarify whether perimuscular connective tissue contains more lymphatic vessels than the shallower layers in human gallbladders. METHODS： Lymphatic vessels were stained immunohistochemically with monoclonal antibody D2-40, which is a specific marker of lymphatic endothelium, in representative sections of 12 normal human gallbladders obtained at the time of resection for colorectal carcinoma liver metastases. In individual gallbladder specimens, nine high-power （×200） fields with the highest lymphatic vessel density （LVD）, termed ＂hot spots＂; were identified for each layer （mucosa, muscle layer, and perimuscular connective tissue）. In individual hot spots, the LVD and relative lymphatic vessel area （LVA） were measured microscopically using a computer-aided image analysis system. The mean LVD and LVA values for the nine hot spots in each layer were used for statistical analyses. RESULTS： In the mucosa, muscle layer, and perimuscular connective tissue, the LVD was 16.1 ± 9.2, 35.4 ± 15.7, and 65.5 ± 12.2, respectively, and the LVA was 0.4 ± 0.4, 2.1 ± 1.1, and 9.4 ± 2.6, respectively. Thus, both the LVD and LVA differed significantly （P 〈 0.001 and P 〈 0.001, respectively; KruskaI-Wallis test） among the individual layers of the wall of the gallbladder, with the highest LVD and LVA values in the perimuscular connective tissue. Most （98 of 108） of the hot spots within the perimuscular connective tissue were located within 500 μm of the lower border of the muscle layer. CONCLUSION： The perimuscular connective tissue contains more and larger lymphatic vessels than the shallower layers in the human gallbladder. This observation partly explains why the incidence of lymph node metastasis is high in T2 （tumor invading the perimuscular connective tissue） or more advanced gallbladder carcinoma.

The lymphatic system:a therapeutic target for central nervous system disorders

The lymphatic vasculature forms an organized network that covers the whole body and is involved in fluid homeostasis,metabolite clearance,and immune surveillance.The recent identification of functional lymphatic vessels in the meninges of the brain and the spinal cord has provided novel insights into neurophysiology.They emerge as major pathways for fluid exchange.The abundance of immune cells in lymphatic vessels and meninges also suggests that lymphatic vessels are actively involved in neuroimmunity.The lymphatic system,through its role in the clearance of neurotoxic proteins,autoimmune cell infiltration,and the transmission of pro-inflammatory signals,participates in the pathogenesis of a variety of neurological disorders,including neurodegenerative and neuroinflammatory diseases and traumatic injury.Vascular endothelial growth factor C is the master regulator of lymphangiogenesis,a process that is critical for the maintenance of central nervous system homeostasis.In this review,we summarize current knowledge and recent advances relating to the anatomical features and immunological functions of the lymphatic system of the central nervous system and highlight its potential as a therapeutic target for neurological disorders and central nervous system repair.

Retrospective evaluation of lymphatic and blood vessel invasion and Borrmann types in advanced proximal gastric cancer

BACKGROUND The Borrmann classification system is used to describe the macroscopic appearance of advanced gastric cancer,and Borrmann typeⅣdisease is independently associated with a poor prognosis.AIM To evaluate the prognostic significance of lymphatic and/or blood vessel invasion(LBVI)combined with the Borrmann type in advanced proximal gastric cancer(APGC).METHODS The clinicopathological and survival data of 440 patients with APGC who underwent curative surgery between 2005 and 2012 were retrospectively analyzed.RESULTS In these 440 patients,LBVI+status was associated with Borrmann typeⅣ,low histological grade,large tumor size,and advanced pT and pN status.The 5-year survival rate of LBVI+patients was significantly lower than that of LBVI– patients,although LBVI was not an independent prognostic factor in the multivariate analysis.No significant difference in the prognosis of patients with Borrmann typeⅢ/LBVI+disease and patients with Borrmann typeⅣdisease was observed.Therefore,we proposed a revised Borrmann typeⅣ(r-BorⅣ)as Borrmann typeⅢplus LBVI+,and found that r-BorⅣwas associated with poor prognosis in patients with APGC,which outweighed the prognostic significance of pT status.CONCLUSION LBVI is related to the prognosis of APGC,but is not an independent prognostic factor.LBVI status can be used to differentiate Borrmann typesⅢandⅣ,and the same approach can be used to treat r-BorⅣand Borrmann typeⅣ.

A Meta-Analysis of Lymphatic Vessel Invasion Correlated with Pathologic Factors in Invasive Breast Cancer

Objectives: The invasive breast cancer is divided into four clinical subtypes: Luminal A-like, Luminal B-like, HER-2 positive, and triple-negative according to the expression status of estrogen receptor (ER), progesterone receptor(PR), human epidermal growth factor receptor-2 (HER-2) and Ki-67. The prognosis and treatment strategy vary with subtypes. The current studies have reported the relation between lymphatic vessel invasion (LVI) and the expression status of ER, PR, HER-2, Ki-67 in invasive breast cancer, but the results were debatable. So the meta-analysis was conducted to confirm the relation between LVI and the four factors. Methods: Literature was searched by entering the terms: breast AND (neoplasm OR cancer OR carcinoma) AND (lymphovascular OR “lymph vessel” OR “lymphatic vessel” invasion OR carcinoma embolus) AND (ER OR estrogen receptor OR PR OR progesterone receptor OR HER-2 OR human epidermal growth factor receptor-2 OR Ki-67 OR clinicopathological) in Pubmed. The merged odds ratio (OR) and 95% confidence interval (CI) were estimated using fixed-effect model. Review Manager 5.2 was used to analysis the relation between LVI and the expression status of ER, PR, HER-2, Ki-67 in invasive breast cancer respectively. The fail-safe number was used to estimate publication bias. Results: The analysis included 5 studies, LVI positive rate was significant lower in ER positive, PR positive, HER-2 negative, low Ki-67 expression group statistically. The OR and 95% CI were 0.6(0.44 - 0.81), 0.64(0.43 - 0.95), 1.52(1.03 - 2.24), 5.29(1.53 - 18.35) respectively.Conclusions:?LVI was significantly correlated with the expression status of ER, PR, HER-2 and Ki-67 in invasive breast cancer. Furthermore, LVI was consistent with poor prognostic expression status of the four factors.

Detection of D2-40 monoclonal antibody-labeled lymphatic vessel invasion in esophageal squamous cell carcinoma and its clinicopathologic significance

Objective： This study aims to investigate the clinicopathologic significance of lymphatic vessel invasion （LVI） labeled by D2-40 monoclonal antibody in esophageal squamous cell carcinoma （ESCC）. Methods： Immunohistochemical assay was used to detect the expression of D2-40 and LVI in 107 ESCC patients. Then, the correlation between the clinicopathologic feature and the overall survival time of the patients was analyzed. Results： The lymph node metastasis rates were 70% and 21% in the LVI-positive and LVI-negative groups, respectively. The nodal metastasis rate was higher in the LVI-positive group than in the LVI-negative group. Multivariate regression analysis showed that LVI was related to nodal metastasis （P〈0.001）. The median survival time of the patients was 26 and 43 months in the LVI-positive and LVI-negative groups, respectively. Mthough univariate regression analysis showed significant difference between the two groups （P=0.014）, multivariate regression analysis revealed that LVI was not an independent prognostic factor for overall survival in the ESCC patients （P=0.062）. Lymphatic node metastasis （P=0.031）, clinical stage （P=0.019）, and residual tumor （P=0.026） were the independent prognostic factors. Conclusion： LVI labeled by D2-40 monoclonal antibody is a risk factor predictive of lymph node metastasis in ESCC patients.

Latanoprost eye drops induce conjunctival lymphatic vessel development

AIM:To investigate the effect of latanoprost eye drops on the conjunctival lymphatics.METHODS:Twenty-four healthy New Zealand White rabbits weighing 1.5 to 2.0 kg were randomly divided into three groups:latanoprost group(n=8)administered with latanoprost eye drops once a day for 2 mo,carteolol group(n=8)administered with carteolol eye drops once a day for 2 mo,and control group(n=8)without any treatment.The conjunctival tissues in the three groups were extracted to investigate the expression levels of 5’-nucleotidase(5’-Nase)by Western blot,reverse transcription-polymerase chain reaction(RT-PCR),and immunofluorescence staining,respectively.RESULTS:The protein expression level of 5’-Nase was significantly higher in latanoprost group than carteolol group(F=231.175,P<0.001)and control group(P<0.001),while there was no significant difference between the carteolol group and the control group(P>0.05).The m RNA expression level of 5’-Nase in the latanoprost group was also significantly higher than carteolol group(F=71.169 P<0.005)and control group(P<0.005).The conjunctival lymphatics were positive immunofluorescence stained with the 5’-Nase antibodies in the latanoprost group and not stained in the control group.CONCLUSION:Latanoprost eye drops can induce conjunctival lymphangiogenesis which may be concerned in clinical implications.

Tumor-Associated Lymphatic and Venous Vessels in Medullary Thyroid Carcinomas

Objective: Medullary thyroid carcinomas (MTCs) invade local lymph node through lymphatic vessels and metastasize to distant organs hematogenously and account for a significant mortality. There are possibly increased lymphatic and venous vessels, through which the tumor spreads to lymph nodes and distant organs. Materials and Methods: By immunocytochemical staining for lymphatic and venous vessels, MTC lesions with adjacent normal thyroid and both normal and metastatic lymph nodes were studied for the peritumoral lymphatic and venous vessels, which were morphometrically compared with those of normal thyroid and lymph nodes. Sixteen cases of MTC cases with adjacent thyroid tissues and attached lymph nodes were immunocytochemically stained for lymphatic vessels using lymphatic vessel hyaluronan receptor (LYVE-1) and venous vessels for factor VIII (F-8). The immunostained sections of MTC lesions and metastatic lymph nodes were morphometrically compared for the number and sizes of the vessels with those of normal thyroid tissues and lymph nodes. Results: Significantly increased lymphatic vessels and markedly increased blood vessels were identified in many MTC cases at the peritumoral tissues and metastatic lymph nodes whereas a few lymphatic vessels and no venous vessels were identified in midst of MTCs. The irregular peritumoral lymphatic vessels resembled that of immature lymphatic vessels observed in papillary thyroid carcinomas and increased irregularly, entrapped venous vessels in peritumoral tissues resembled those observed in follicular thyroid carcinomas. Conclusion: The significantly increased lymphatic vessels and markedly increased venous vessels in the peritumoral thyroid tissue support a propensity of MTCs for providing an easy access of tumor cells to both lymphatic spread to the regional lymph nodes and venous spread to distant organs with further tumor spread through metastatic lymph nodes by moderately increased lymphatic and venous vessels.

Cancer-Associated Lymphatic and Venous Vessels in Colonic Carcinomas

Objective: Colonic carcinomas spread to regional lymph nodes and liver. There are cancer-associated lymphatic and venous vessels at the margin of colonic carcinomas, which facilitate spreading carcinoma through lymphatic and venous vessels. This study aimed to examine cancer-associated lymphatic and venous vessels in TNM T1 to T3 carcinomas using lymphatic vessel hyaluronan receptor for lymphatic vessels and von Willebrand factor for venous vessels by immunocytochemical staining. Materials and Methods: A total of 40 cases of moderately differentiated colonic carcinoma were studied using routinely formalin-fixed and paraffin-embedded sections. The cases consisted of 10 cases of TNM T1, 15 cases each of T2 and T3 cases. Immunocytochemical staining was performed using goat antihuman LYVE-1for lymphatic vessels and rabbit antihuman von Willebrand factor for venous vessels. Results: In TNM T1 carcinoma, increased, irregular and narrow lymphatic and venous vessels were present in the adjacent normal mucosa to the carcinoma, some of which penetrated cancerous lesion. There were no tumor emboli in lymphatic and venous vessels. In TNM T2 carcinoma, there were few lymphatic and venous vessels in midst of the carcinoma whereas numerous small lymphatic and venous vessels were present within muscle layers adjacent to the invading carcinoma. Extramural tumor embolus was present in submucosa in one case. In TNM T3 carcinoma, cancer has invaded through the muscle layers where dilated lymphatic and venous vessels were present adjacent to cancerous nests. Tumor emboli were identified in two cases by immunocytochemical staining. Conclusion: The current study showed cancer-associated lymphatic and venous vessels at the interface in TNM T1 carcinoma to dilated intramuscular lymphatic and venous vessels adjacent to invading cancerous nests in TNM T3 carcinoma, and supports cancerous cells spread via lymphatic and venous vessels through muscle layers to subserosa as supported by tumor emboli in the lymphovascular system.

Cyclic Changes of Lymphatic and Venous Vessels in Human Endometrium

Context: Cyclic changes of endometrial arteries are well established but possible cyclic changes of lymphatic and venous vessels have not been fully documented. There are no published morphological reports to support cyclic changes of endometrial lymphatic and venous vessels. Objective: Using cryosections of human endometrium, this study aimed to unveil possible cyclic changes of lymphatic and venous vessels. We previously reported cyclic changes of lymphatic vessels in human endometrium using D2-40. Design: A total of 16 cases representing menstrual, proliferative and mid and late secretary phase were studied. For Immunocytochemical staining, lymphatic vessel endothelial hyaluronan receptor 1 and von Willebr and factor were used for lymphatic and venous vessels, respectively. We used polyclonal LYVE-1 in this study, which revealed more lymphatic vessels than using D2-40. Results: Residual lymphatic and venous vessels were present in menstrual basalis. In Day 5 - 9 endometrium, there were sparse lymphatic vessels but were numerous growing venous vessels in thin proliferating functionalis. In Day 14 - 22 endometrium, there were scattered lymphatic vessels and numerous venous vessels in functionalis. In Day 25 - 26 endometrium, there were many dilated lymphatic vessels and numerous dilated, disintegrating venous vessels in upper functionalis than lower functionalis. Conclusion: The above findings support that lymphatic vessels are sparse but venous vessels are numerous in early proliferative functionalis. Lymphatic vessels grow from basalis to thin functionalis. In premenstrual phase, lymphatic vessels proliferate from lower to upper functionalis, and both lymphatic and venous vessels disintegrate for shedding by this immunocytochemical study using lymphatic and venous markers. Thus, all lymphatic, venous and arterial vessels undergo menstrual cyclic changes and shed for menstruation.

Cyclic Changes of Lymphatic Vessels in Human Endometrium

Objective: The presence of lymphatic vessels in endometrium has been controversial and recent immunocytochemical studies with routinely paraffin embedded sections revealed lymphatic vessels in basalis and occasionally in functionalis. We aimed to investigate endometrial lymphatic vessels by immunocytochemical staining using cryosections, which provided better and consistent immunostaining for lymphatic vessels with a lymphatic marker, D2-40. We aimed further to explore the structure-function relationship of lymphatic vessels in the menstrual cycle. Materials and Methods: Sixteen cases of endometrium from menstrual, early-proliferative to latesecretary phase were immunostained for D2-40 and lymphatic vessels were morphometrically analyzed for functionalis, basalis and myometrium, respectively. Results: Lymphatic vessels were consistently most numerous in myometrium, followed by basalis in all phases whereas menstrual endometrium showed small, fragmented aggregates of lymphatic vessels in thin basalis. Earlyto mid-secretary endometrium revealed many lymphatic vessels in basalis and lower-functionalis with few lymphatic vessels in upper-functionalis. Late-secretary endometrium revealed more lymphatic vessels in upper-functionalis with dilated walls, which then burst at the surface of functionalis. Conclusions: These degenerating lymphatic vessels with markedly dilated lumen in upper-functionalis may contribute to lymphatic leakage in late-secretary phase. These immunostained lymphatic vessels in functionalis support proliferating and degenerating lymphatic vessel cycle synchronized with the menstrual cycle of endometrial arteries to maintain adequate fluid leakage.

Peripapillary vessel density and retinal nerve fiber layer thickness changes in early diabetes retinopathy

·AIM:To perform a quantitative analysis of the peripapillary vessel density(VD)and retinal nerve fiber layer(RNFL)thickness changes in patients with early stage of diabetic retinopathy(DR).·METHODS:In this case-control study,swept-source optical coherence tomography angiography(SS-OCTA)imaging was used to examine diabetic and age-matched healthy subjects.The optic disc HD 6×6 mm^(2) blood flow imaging scan mode was selected.Automatic software was used to measure the peripapillary VD,capillary vessel density(CVD),and RNLF in an optic nerve head(ONH)filed based on the Garway-Heath map.In addition,the correlation between peripapillary VD,CVD,and RNFL was further investigated.·RESULTS:The cohort consisted of 32 healthy individuals and 72 patients with diabetes(34 eyes with no DR and 38 eyes with mild-moderate NPDR).Peripapillary VD decreased in the mild-moderate NPDR group compared to the control group in most regions(P<0.05).Peripapillary CVD and RNFL thickness were significantly lower in the mild-moderate NPDR group in the superior temporal(ST)quadrants(P=0.018.P=0.030).In the correlation analysis of each region,the RNFL thickness in the NS region was positively correlated with the peripapillary VD and CVD(r=0.233,P=0.05;r=0.288.P=0.015).In the TI region,the RNFL thickness was positively correlated with the peripapillary CVD(r=0.237,P=0.047).·CONCLUSION:The measurement based on the ONH topographic map may be helpful in detecting functional and structural impairments in DR.The peripapillary VD,CVD and RNFL decrease in early DR,and the RNFL thickness altered in association with the CVD or/and VD in some regions.

Evaluation of macular vessel density changes after vitrectomy with silicone oil tamponade in patients with rhegmatogenous retinal detachment

AIM:To evaluate macular microvasculature changes in eyes after pars plana vitrectomy(PPV)and intraocular silicone oil(SO)tamponade for macula-off rhegmatogenous retinal detachment(RRD)using optical coherence tomography angiography(OCTA).METHODS:Totally 19 eyes(19 patients)with maculaoff RRD who underwent PPV and intraocular SO tamponade were retrospectively reviewed.The parafoveal superficial capillary plexus(SCP)vessel density(VD),deep capillary plexus(DCP)VD,choriocapillaris plexus(CCP)VD,and foveal macular thickness were evaluated using OCTA throughout 16 wk postoperatively.The values of healthy fellow eyes were used as control.RESULTS:The parafoveal SCP,DCP,and CCP VDs were significant increased over time in RRD eyes during the 12 wk postoperatively,then decreased at 16 wk postoperatively(all P<0.01).The ratios of RRD eyes and fellow healthy eyes(r/f ratios)of the SCP and DCP VDs were lower than those of the CCP VD postoperatively(all P<0.05).There were not significant differences in the r/f ratios between SCP and DCP VDs postoperatively(all P>0.05).CONCLUSION:The parafoveal SCP,DCP,and CCP VDs gradually recover over time after PPV surgery with SO tamponade.Long-time SO tamponade might decrease postoperative macular VDs.Compared to parafoveal CCP VD,the parafoveal SCP and DCP VDs were more vulnerable in RRD eyes postoperatively.

Relationship between LYVE-1, VEGFR-3 and CD44 gene expressions and lymphatic metastasis in gastric cancer

AIM: To investigate the expression levels of lymphatic vessel endothelial hyaluronan receptor-1 (LYVE-1), vascular endothelial growth factor receptor-3 (VEGFR-3) and CD44 genes and the relationship between their lev- els and clinicopathological parameters in gastric cancer.METHODS: Tissue samples were obtained from 33 patients (8 females) with gastric cancer. mRNA levels of LYVE-1, VEGFR-3 and CD44 in normal and tumor tissues were quantitatively measured using real time polymerase chain reaction. The results were correlated with lymph node metastasis, histological type and differentiation of the tumor, T-stage, and presence of vascular, perineural and lymphatic invasions. The distribution of molecules in the tissue was evaluated using immunohistochemistry. RESULTS: LYVE-1, CD44 and VEGFR-3 gene expression levels were significantly higher in gastric cancer than in normal tissue. While there was no correlation between gene expressions and clinicopathologic fea- tures such as histologic type, differentiation and stage, gene expression levels were found to be increased in conjunction with positive lymph node/total lymph node ratio and the presence of perineural invasion. A significant correlation was also found between LYVE-1 and CD44 over-expressions and perineural invasion and lymph node positivity in gastric cancers. When the dis- tribution of LYVE-1 antibody-stained lymphatic vessels in tissue was evaluated, lymphatic vessels were located intra-tumorally in 13% and peri-tumorally in 27% of the patients. Moreover, lymph node metastases were also positive in all patients with LYVE-1-staining. CONCLUSION: LYVE-1, VEGFR-3 and CD44 all play an important role in lymphangiogenesis, invasion and metastasis. LYVE-1 is a perfectly reliable lymphatic vessel marker and useful for immunohistochemistry.