Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 14 de 14
Filter
1.
Gynecol Oncol ; 183: 15-24, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38492474

ABSTRACT

OBJECTIVE: To establish the safety and quality of ovarian cortex surrounding epithelial ovarian tumors in women eligible for fertility-sparing surgery by identifying occult malignant lesions and characterizing the ovarian follicle pool. METHODS: Multicentric retrospective study of 48 subjects (15-45 years), diagnosed with borderline ovarian tumors (BOTs) or early-stage epithelial ovarian cancers (EOCs) and eligible for fertility-sparing surgery. Histological samples of ovarian cortex surrounding tumors were analyzed to characterize the follicle pool, find any occult malignant lesion using tumor-specific markers (cytokeratin 7 and mucin 1), and quantify tumor-infiltrating lymphocytes (TILs) by CD3 and tumor associated macrophages (TAMs) by CD68. RESULTS: Occult ovarian lesions were observed in 6 out of 45 cases investigated (14.6%), including one mucinous stage-I BOT (1/14), one serous stage-I BOT (1/13), 3 advanced-stage serous BOTs (3/11) and one early-stage serous EOC (1/7). Notably, follicle density was significantly lower in subjects diagnosed with ovarian tumors compared to controls (p < 0.001) and at a younger age. Significantly higher follicle atresia was encountered in the ovarian tumor group then in controls (20.1 ± 8.8% vs 9.2 ± 9.4%, p < 0.001) at all ages. Both TILs and TAMs were found in ovarian tumors irrespective of histotype, but no link was established with the status of the ovarian reserve. CONCLUSIONS: Personalized counseling for fertility preservation is required in the event of BOTs and early-stage EOCs. Fertility-sparing surgery and adjuvant gamete preservation should be considered, balancing the oncological risks according to tumor stage and histotype and fertility potential, especially at a younger age.


Subject(s)
Carcinoma, Ovarian Epithelial , Fertility Preservation , Ovarian Neoplasms , Humans , Female , Adult , Ovarian Neoplasms/pathology , Ovarian Neoplasms/surgery , Ovarian Neoplasms/immunology , Retrospective Studies , Fertility Preservation/methods , Adolescent , Young Adult , Carcinoma, Ovarian Epithelial/pathology , Carcinoma, Ovarian Epithelial/surgery , Carcinoma, Ovarian Epithelial/immunology , Middle Aged , Neoplasm Staging , Lymphocytes, Tumor-Infiltrating/immunology , Ovary/pathology , Ovary/surgery , Ovarian Follicle/pathology
2.
Hum Reprod ; 38(1): 75-88, 2023 01 05.
Article in English | MEDLINE | ID: mdl-36346333

ABSTRACT

STUDY QUESTION: Which biological mechanisms are responsible for physiological ovarian reserve decline owing to aging, or pathological follicle depletion triggered by inflammation or a pro-oxidant environment throughout a woman's lifetime? SUMMARY ANSWER: Ovarian follicle pool size is modulated by both apoptosis and autophagy, the first responsible for its physiological decline over time and increasing in the event of prior chemotherapy in children, and the latter playing a major role in physiological ovarian follicle pool diminution before puberty. WHAT IS KNOWN ALREADY: Among the different pathways of controlled cell death, apoptosis and autophagy are implicated in follicle loss. Apoptosis participates in eliminating damaged follicles, such as those impaired by chemotherapy (CHT), but its involvement in physiological age-related follicle decline is less well understood. Autophagy has proved crucial in follicle quiescence maintenance in murine models, but its contribution to human follicle pool modulation is still unclear. STUDY DESIGN, SIZE, DURATION: This retrospective study included 84 patients with benign or malignant extra-ovarian conditions aged between 1 and 35 years, with ovarian tissue stored for histological analyses at the time of cryopreservation (between 2012 and 2021) at a tertiary care center. PARTICIPANTS/MATERIALS, SETTING, METHODS: Ovarian fragments were used for the following analyses: hematoxylin and eosin staining for follicle count and classification; cleaved caspase-3 immunostaining to identify follicle apoptosis; and microtubule-associated proteins 1A/1B light chain 3B immunolabeling to detect follicle autophagy. Transmission electron microscopy was also carried out to investigate ultrastructural features of oocytes and granulosa cells. All analyses stratified patients by age, menarchal status (premenarchal = 32; postmenarchal = 52), potentially gonadotoxic CHT before cryopreservation (n = 14), presence of endometriosis and use of hormonal treatment. MAIN RESULTS AND THE ROLE OF CHANCE: Premenarchal patients had a larger follicle pool in terms of total follicle density [mean, range 4979.98 (342.2-21789) versus 918.8 (26.18-3983), P < 0.001], but higher rates of morphologically abnormal [8.52 (0-25.37)% versus 3.54 (0-17.5)%, P < 0.001] and atretic [15.8 (0‒31.85)% versus 10.6 (0-33.33)%, P < 0.01] follicles than postmenarchal subjects. Apoptosis rates did not change with increasing age [27.94 (0-93.2)% in prepubertal subjects and 29.5 (0-100)% in postpubertal subjects], but autophagic follicles were around 10 times more common in premenarchal than postmenarchal subjects [10.21 (0-62.3)% versus 1.34 (0-25)%, P < 0.001], playing a crucial role in age-related follicle decline and elimination of 'abnormal' follicles, that are rarely seen after menarche. The impact of diagnosis and previous CHT varied according to age. In premenarchal patients with previous CHT, significantly more apoptotic [40.22 (0-100)% versus 26.79 (0-87)%, P < 0.05] and fewer abnormal [3.84 (0-10-76)% versus 9.83 (0-25.37)%, P < 0.01] follicles were detected than in subjects with no CHT prior to ovarian tissue cryopreservation, suggesting a direct effect on follicle elimination, especially of those with abnormalities. In postmenarchal subjects with previous CHT, quiescent follicle rates were lower than in patients with no CHT before tissue freezing [71.57 (0-100)% versus 85.89 (50-100)%, P < 0.05], suggesting accelerated follicle activation and growth. Moreover, increased autophagic activity was observed in the event of a cancer diagnosis compared to benign conditions after puberty [26.27 (0-100)% versus 9.48 (0-29.41)%, respectively, P < 0.05]. LIMITATIONS, REASONS FOR CAUTION: The impact of specific CHT protocols could not be investigated since the group of patients with previous CHT was highly heterogeneous. WIDER IMPLICATIONS OF THE FINDINGS: This study yields a deeper understanding of regulation of the follicle pool decline, showing for the first time that both apoptosis and autophagy pathways are involved in physiological follicle depletion, the latter being crucial before puberty. Moreover, our data showed a different response to non-physiological damage according to age, with higher apoptosis rates only in premenarchal subjects with previous CHT, confirming that this pathway is activated by drugs known to induce DNA damage in oocytes, such as alkylating agents, but not by cancer itself. STUDY FUNDING/COMPETING INTEREST(S): This study was supported by grants from the Fonds National de la Recherche Scientifique de Belgique (F.R.S.-FNRS/FRIA FC29657 awarded to L.C., CDR J.0063.20 and grant 5/4/150/5 awarded to M.M.D.), grants from the Fondation contre le Cancer (grant 2018-042 awarded to A.Ca.), the Fondazione Comunitaria del Varesotto and Provincia di Varese ('Amalia Griffini' Fellowship in Gynecology and Obstetrics awarded to A.Ce.), Fonds Spéciaux de Recherche, Fondation St Luc and donations from the Ferrero family. The authors have no competing interests to declare. TRIAL REGISTRAION NUMBER: N/A.


Subject(s)
Neoplasms , Ovarian Diseases , Child , Female , Humans , Animals , Mice , Infant , Child, Preschool , Adolescent , Young Adult , Adult , Retrospective Studies , Ovarian Follicle/metabolism , Ovarian Diseases/metabolism , Apoptosis , Autophagy
3.
Hum Reprod ; 35(12): 2793-2807, 2020 12 01.
Article in English | MEDLINE | ID: mdl-33326997

ABSTRACT

STUDY QUESTION: Can human theca cells (TCs) be differentiated in vitro? SUMMARY ANSWER: It is possible to differentiate human TCs in vitro using a medium supplemented with growth factors and hormones. WHAT IS KNOWN ALREADY: There are very few studies on the origin of TCs in mammalian ovaries. Precursor TCs have been described in neonatal mice ovaries, which can differentiate into TCs under the influence of factors from oocytes and granulosa cells (GCs). On the other hand, studies in large animal models have reported that stromal cells (SCs) isolated from the cortical ovarian layer can also differentiate into TCs. STUDY DESIGN, SIZE, DURATION: After obtaining informed consent, ovarian biopsies were taken from eight menopausal women (53-74 years of age) undergoing laparoscopic surgery for gynecologic disease not related to the ovaries. SCs were isolated from the ovarian cortex and in vitro cultured for 8 days in basic medium (BM) (G1), enriched with growth factors, FSH and LH in plastic (G2) or collagen substrate without (G3) or with (G4) a GC line. PARTICIPANTS/MATERIALS, SETTING, METHODS: To confirm TC differentiation, relative mRNA levels for LH receptor (Lhr), steroidogenic acute regulatory protein (Star), cholesterol side-chain cleavage enzyme (Cyp11a1), cytochrome P450 17A1 (Cyp17a1), hydroxy-delta-5-steroid dehydrogenase, 3 beta- and steroid delta-isomerase 1 (Hsd3b1) and hydroxy-delta-5-steroid dehydrogenase, 3 beta- and steroid delta-isomerase 2 (Hsd3b2) were assessed. Immunohistochemistry was also performed for their protein detection and a specific marker was identified for TCs (aminopeptidase-N, CD13), as were markers for theca and small luteal cells (dipeptidyl peptidase IV (CD26) and Notch homolog 1, translocation-associated (NOTCH1)). Finally, we analyzed cell ultrastructure before (Day 0) and after in vitro culture (Day 8), and dehydroepiandrosterone (DHEA) and progesterone levels in the medium using transmission electron microscopy (TEM) and ELISA, respectively. MAIN RESULTS AND THE ROLE OF CHANCE: Results obtained from qPCR showed a significant increase (P < 0.05) in mRNA levels of Lhr in F2 (floating cells in G2) and G4, Cyp17a1 in G1 and F1 (floating cells in G1) and Hsd3b2 in G1, G2, G3 and G4. Immunohistochemistry confirmed expression of each enzyme involved in the steroidogenic pathway at the protein stage. However, apart from G1, all other groups exhibited a significant (P < 0.05) rise in the number of CD13-positive cells. There was also a significant increase (P < 0.05) in NOTCH1-positive cells in G3 and G4. Ultrastructure analyses by TEM showed a distinct difference between groups and also versus Day 0. A linear trend with time revealed a significant gain (q < 0.001) in DHEA concentrations in the medium during the culture period in G1, G2, G3 and G4. It also demonstrated a statistical increase (q < 0.001) in G2, G3 and G4 groups, but G1 remained the same throughout culture in terms of progesterone levels. LARGE SCALE DATA: N/A. LIMITATIONS, REASONS FOR CAUTION: Shorter periods of in vitro culture (e.g. 2, 4 and 6 days) could have led to increased concentrations of differentiated TCs in G2, G3 and G4. In addition, a group of cells cultured in BM and accompanied by COV434 cells would be necessary to understand their role in the differentiation process. Finally, while our results demonstrate that TCs can be differentiated in vitro from cells isolated from the cortical layer of postmenopausal ovaries, we do not know if these cells are differentiated from a subpopulation of precursor TCs present in ovarian cortex or ovarian SCs in general. It is therefore necessary to identify specific markers for precursor TCs in human ovaries to understand the origin of these cells. WIDER IMPLICATIONS OF THE FINDINGS: This is a promising step toward understanding TC ontogenesis in the human ovary. Moreover, in vitro-generated human TCs can be used for studies on drug screening, as well as to understand TC-associated pathologies, such as androgen-secreting tumors and polycystic ovary syndrome. STUDY FUNDING/COMPETING INTEREST(S): This study was supported by grants from the Fonds National de la Recherche Scientifique de Belgique (FNRS) (C.A.A. is an FRS-FNRS Research Associate; grant MIS #F4535 16 awarded to C.A.A.; grant 5/4/150/5 awarded to M.M.D.; grant ASP-RE314 awarded to P.A.) and Foundation Against Cancer (grant 2018-042 awarded to A.C.). The authors declare no competing interests.


Subject(s)
Ovary , Theca Cells , Animals , Cell Differentiation , Female , Granulosa Cells , Humans , Postmenopause
6.
Acta Clin Belg ; 70(2): 133-7, 2015 Apr.
Article in English | MEDLINE | ID: mdl-25363715

ABSTRACT

BACKGROUND: Solitary extramedullary plasmacytoma (SEP) is a rare malignant neoplasm arising from plasma cells. SEP mostly occurs in the upper respiratory tract. Thyroid gland is rarely affected (<78 cases). METHODS/RESULTS: We describe the case of a 78-year-old woman presenting a rapidly enlarging palpable thyroid mass. Neck computed tomography scan showed enlargement of both thyroid lobes. Laboratory tests were normal, including serum protein level with no monoclonal gamma globulin peak. Cytology was suspicious for lymphoma. Biopsy showed an infiltrating neoplasm composed of atypical tumor cells with abundant cytoplasm and eccentric nuclei. These revealed diffuse immunoreactivity for CD138 and predominant staining for immunoglobulin kappa light chains. Clinical workup for multiple myeloma was negative. CONCLUSIONS: SEP should be considered in the differential diagnosis of a rapidly enlarging thyroid nodule and be distinguished from involvement of thyroid in multiple myeloma, mucosa-associated lymphoid tissue lymphoma, plasma cell granuloma and medullary carcinoma. Clinical correlation and immunohistochemistry are crucial in avoiding pitfalls.


Subject(s)
Plasmacytoma/pathology , Thyroid Neoplasms/pathology , Aged , Carcinoma, Neuroendocrine , Diagnosis, Differential , Female , Humans , Plasma Cells/pathology , Plasmacytoma/blood , Plasmacytoma/chemistry , Plasmacytoma/diagnosis , Thyroid Neoplasms/blood , Thyroid Neoplasms/chemistry , Thyroid Neoplasms/diagnosis
7.
Acta Clin Belg ; 70(3): 218-22, 2015 Jun.
Article in English | MEDLINE | ID: mdl-25541210

ABSTRACT

Although post-transplant lymphoproliferative disorder is a classical complication encountered after kidney transplantation, its diagnosis can still be challenging and its outcome life-threatening. Most cases are related to Epstein-Barr virus (EBV) infection and occur mainly in the first year post-transplant, favoured by the seronegative EBV status of the recipient transplanted with a kidney from a seropositive donor, and strong immunosuppression. We report the case of a young kidney-pancreas transplant recipient who developed post-transplant lymphoproliferative disorder (PTLD) early after transplantation, with a rapid fatal issue. We review the pathogenesis, clinical presentation, and management of PTLD with a focus on prevention.


Subject(s)
Epstein-Barr Virus Infections , Immunosuppressive Agents/adverse effects , Kidney Transplantation , Lymphoproliferative Disorders , Pancreas Transplantation , Postoperative Complications , Adult , Diabetes Mellitus, Type 1/complications , Diagnosis, Differential , Epstein-Barr Virus Infections/diagnosis , Epstein-Barr Virus Infections/etiology , Epstein-Barr Virus Infections/physiopathology , Fatal Outcome , Female , Humans , Immunosuppressive Agents/administration & dosage , Kidney Failure, Chronic/etiology , Kidney Failure, Chronic/surgery , Kidney Transplantation/methods , Lymphoproliferative Disorders/diagnosis , Lymphoproliferative Disorders/etiology , Lymphoproliferative Disorders/physiopathology , Lymphoproliferative Disorders/therapy , Pancreas Transplantation/adverse effects , Pancreas Transplantation/methods , Positron-Emission Tomography/methods , Postoperative Complications/diagnosis , Postoperative Complications/physiopathology , Postoperative Complications/therapy
9.
J Assist Reprod Genet ; 30(10): 1289-99, 2013 Oct.
Article in English | MEDLINE | ID: mdl-23989997

ABSTRACT

PURPOSE: To assess the safety of reimplantation of cryopreserved ovarian tissue from advanced-stage breast cancer patients. METHODS: Cryopreserved ovarian cortical fragments were obtained from 13 advanced-stage breast cancer patients aged 17-35 years. After thawing, part of the ovarian cortical tissue was grafted to severe combined immunodeficient mice for 6 months. The presence of malignant mammary cells in ovarian tissue was evaluated after thawing as well as after grafting by 1) histology and immunohistochemistry (epithelial membrane antigen, Her2/neu and gross cystic disease fluid protein 15 identification), and 2) detection of the MGB2 gene by qPCR. RESULTS: No malignant cells were evidenced by histology and immunohistochemistry. None of the mice died during the 6-month grafting period, nor developed macroscopically visible masses. MGB2 gene expression was detected by qPCR and confirmed by sequencing in frozen-thawed ovarian tissue in 4 cases and in grafts in 1 case. CONCLUSIONS: This pilot study is the first to evaluate the risk of contamination of cryopreserved ovarian tissue from advanced-stage breast cancer patients by xenotransplantation for 6 months to immunodeficient mice, associated with more conventional screening methods. Our xenografting results are reassuring, but caution needs to be exercised, as MGB2 gene expression was detected in some cases. Larger numbers of ovarian tissue samples from patients with advanced-stage breast cancer are required to confirm our findings before ovarian tissue transplantation can be contemplated in these patients.


Subject(s)
Breast Neoplasms/pathology , Fertility Preservation/methods , Ovarian Follicle/transplantation , Adolescent , Adult , Aged, 80 and over , Animals , Carrier Proteins/metabolism , Cryopreservation , Female , Glycoproteins/metabolism , Humans , Mammaglobin B/biosynthesis , Mammaglobin B/genetics , Membrane Transport Proteins , Mice , Mice, SCID , Pilot Projects , Receptor, ErbB-2/metabolism , Transplantation, Heterologous , Young Adult
11.
Cryobiology ; 67(1): 64-9, 2013 Aug.
Article in English | MEDLINE | ID: mdl-23688636

ABSTRACT

BACKGROUND: One major concern of grafting cryopreserved ovarian tissue to restore fertility in cancer patients is the possibility of reintroducing tumor cells. Cryopreservation of isolated primordial/primary follicles (PFs) may circumvent this problem. The aim of our work was to compare dimethyl sulfoxide (ME2SO) and ethylene glycol (EG) as cryoprotectants (CPAs) for slow-freezing of isolated human PFs in alginate. METHODS: Ovarian biopsies from four women were processed for follicle isolation. PFs were embedded in alginate (5-15 per group). Follicles were frozen-thawed using 1.4M ME2SO or 1.5M EG as CPAs. Fresh and cryopreserved isolated follicles were in vitro cultured (IVC) for 7 days. At different time periods (after isolation, cryopreservation and IVC), follicles were evaluated with live/dead assay (using fluorescent probes) and diameter measurement. Follicle viability was calculated according to the percentage of dead follicular cells and the presence of a live/dead oocyte. RESULTS: A total of 841 PFs were isolated, embedded in alginate and cryopreserved with ME2SO (n=424) or EG (n=259), or used as controls (n=158). After 7 days of IVC, a significant increase in follicle size was observed in the fresh and ME2SO groups, but not in the EG group. The percentage of totally viable PFs was not significantly different before or after seven days of culture in fresh (100% and 82%) or ME2SO (93.2% and 85.1%) tissue. The EG group showed significantly lower viability before (63.9%) and after IVC (66.2%) than the fresh and ME2SO groups. CONCLUSIONS: Our results show that 1.4M ME2SO yields better preservation of isolated PF viability after thawing and 7 days of IVC than 1.5M EG. Alginate constitutes an easy, safe hydrogel matrix to handle and cryopreserve isolated human follicles using ME2SO as a CPA.


Subject(s)
Alginates/pharmacology , Cryopreservation/methods , Cryoprotective Agents/pharmacology , Dimethyl Sulfoxide/pharmacology , Ethylene Glycol/pharmacology , Ovarian Follicle , Adult , Cell Survival/drug effects , Cells, Cultured , Female , Freezing , Glucuronic Acid/pharmacology , Hexuronic Acids/pharmacology , Humans , Young Adult
12.
Clin Exp Obstet Gynecol ; 36(1): 26-30, 2009.
Article in English | MEDLINE | ID: mdl-19400414

ABSTRACT

Microcolposcopy is an in vivo cytological examination of the uterine cervix allowing the localization of exoendocervical precancerous lesions. The aim of this study was to assess the diagnostic reliability of microcolposcopy by means of correlation with histology, colposcopy and Pap test results. For the study, 256 patients with abnormal Pap test results were selected and subjected to colposcopy and microcolposcopy with the aim of evaluating the presence of any intraepithelial lesions. One hundred and nine of these patients were subjected to a biopsy. Colposcopy, histology and cytology results were compared with those obtained by microcolposcopy. In low-grade squamous intraepithelial lesion (LSIL) cytology cases, the percentage agreement on lesion grade between Pap test and microcolposcopy results was 74%, while in high-grade squamous intraepithelial lesion (HSIL) cytology cases, it was equal to 80%. The comparison between colposcopy and microcolposcopy showed a level of agreement of 72% for lower grades and 68% for higher grades. Finally, histology was in agreement with microcolposcopy in 73% of cervical intraepithelial grade 1 neoplasia (CIN 1) cases and reached 71% for CIN 2-3. Microcolposcopy proved to be accurate with regard to the diagnosis of lesion grade, and showed to be definitive in patients where cytology was positive for HPV infection and colposcopy was not able to identify any lesions.


Subject(s)
Colposcopy/methods , Uterine Cervical Dysplasia/pathology , Uterine Cervical Neoplasms/pathology , Biopsy , Cervix Uteri/pathology , Cohort Studies , Female , Humans , Sensitivity and Specificity , Vaginal Smears
13.
Ital J Anat Embryol ; 110(2 Suppl 1): 117-25, 2005.
Article in English | MEDLINE | ID: mdl-16101029

ABSTRACT

Expanded polytetrafluoroethylene (PTFE) prostheses may be used in peripheral vascular surgery. Due to contradictory results on patency rate and neointimal formation, the effectiveness of this kind of prosthesis in small caliber artery reconstruction is still under discussion. In order to evaluate the effectiveness of this technique 1 mm internal diameter PTFE prosthesis (fibril length 35 microm) interposed in rabbit femoral artery, for 15 and 30 days, were studied functionally and morphologically. Doppler was performed during surgery, at day 2, 15 and 30. Arteriography was carried out at day 1. Light microscopy and scanning electron microscopy were performed on prosthesis sampled at day 15 and 30. Doppler flowmetry showed the full patency in all PTFE prosthesis. Angiography confirmed that all PTFE grafts were patent after 24 h. Doppler flowmetry, performed after 15 and 30 days, showed a reducing patency rate respectively at 70% (21 grafts) and 60% (18 grafts). Morphological studies showed that endothelial lining was not present at 15 day. After 30 days proliferation of blood cells occurred in the graft wall. Lumina presented a fibrous lining and did not show significant endothelial cell growths. These results confirm that PTFE prosthesis represents a suitable alternative to biological graft for the repair of small caliber artery when the latter are not available. Autologous vein is the vascular substitute of choice for peripheral vascular reconstruction, and PTFE prosthesis may be quite successfully used as a secondary choice, when multiple reconstruction are needed and biological grafts are not sufficient.


Subject(s)
Arteries/surgery , Blood Vessel Prosthesis Implantation/instrumentation , Blood Vessel Prosthesis Implantation/methods , Blood Vessel Prosthesis , Vascular Patency/physiology , Angiography , Animals , Arteries/injuries , Arteries/ultrastructure , Blood Vessel Prosthesis/statistics & numerical data , Femoral Artery/surgery , Femoral Artery/ultrastructure , Graft Occlusion, Vascular/physiopathology , Graft Occlusion, Vascular/prevention & control , Laser-Doppler Flowmetry , Male , Microscopy, Electron, Scanning , Polytetrafluoroethylene , Rabbits , Regional Blood Flow/physiology , Time Factors , Transplantation, Autologous/standards , Treatment Outcome , Veins/transplantation
14.
Histol Histopathol ; 17(3): 699-706, 2002.
Article in English | MEDLINE | ID: mdl-12168777

ABSTRACT

Myocardial connective tissue probably provides passive support for regulating heart tensile strength and stiffness and ultimately for controlling heart mechanics through its endomysial part. However, endomysial collagen micro-arrangement is still a matter of debate. In order to define the fine distribution of left ventricle endomysial collagen, we applied the NaOH-scanning electron microscopy (SEM) maceration method (one of the techniques of choice for studying collagen micro-arrangement) to rabbit heart. Gomori-reticulum staining was used for correlated light microscopy (LM) observations. The SEM-NaOH method allowed isolation of collagen by removing other extracellular matrix components and cells and preserved collagen structure and position. Endomysial collagen appeared arranged in laminae that delimited the lacunae that were left empty by macerated myocytes and small vessels (mostly capillaries). These laminae were formed by reticular fibers, as confirmed by LM observations of Gomorireticulum-stained samples, and were organized in irregularly meshed networks made of thin (single) and thick (composed) filaments. In longitudinal views, collagen laminae extended the entire length of lacunae. In transversal views, the cut surface of the laminae appeared to be made of collagen bundles. These observations provide an updated microanatomical view of endomysial collagen distribution, which integrates previous studies. This model is based on the evidence that collagen laminae enveloped the surface of small vessels and myocytes. Thus, a type of myocyte-myocyte or capillary-myocyte "laminar connection" anchored to the entire cell length here is emphasized, rather than a type of "strut connection" anchored to defined loci, as usually described. This structure explains better how endomysium may provide the necessary support for heart compliance and protection against overstretch.


Subject(s)
Collagen/biosynthesis , Collagen/metabolism , Myocardium/metabolism , Myocardium/ultrastructure , Animals , Extracellular Matrix/metabolism , Heart Ventricles/metabolism , Heart Ventricles/ultrastructure , Microscopy, Electron, Scanning , Rabbits , Tissue Distribution
SELECTION OF CITATIONS
SEARCH DETAIL
...