[Causes and management of pediatric spontaneous tonsillar haemorrhage]

Objective: To analyze the causes and management plan of pediatric spontaneous tonsillar haemorrhage(STH). Methods: According to the criteria of STH difined by Griffies, patients with STH from December 2013 to January 2016 were included in this retrospective study. Results: A total of 11 patients were reviewed. The etiological diagnosis included 3 pediatric Epstein-Barr virus associated infectious mononucleosis(EBV-IM), 3 suspected pediatric EBV-IM to 3 acute suppurative tonsillitis, 1 acute viral tonsillitis and 1 hemophilia A. The management strategies included antiviral, antibacteria, transfusion, surgical examination followed with bipolar coagulation hemostasis under general anesthesia. No patient treated with tosillectomy. Conclusions: STH is now a rare condition, the causes of which in child are more or less different from adult.This emergency can be treated in time if a detailed management plan for pediatric STH is formulated.

[Identification of the specific topographic features of the neck vessels for the prevention of bleedings during tonsillectomy]

The objective of the present work was to study syntopy of the large neck vessels in relation to the capsule of palatine tonsils with the use of the MRI technology. A total of 109 patients (218 palatine tonsils) presenting with chronic tonsillitis were available for the examination including 64 women and 45 men at the age varying from 15 to 54 years. All of them underwent MRI-guided vascular visualization in the paratonsillar region together with the measurements of the vessels extending to the capsule of the palatine tonsils at the level of the upper and lower poles, and also close to the mid-third of each palatine tonsil. The distance from the external carotid artery to the upper and lower poles of the palatine tonsils was found to be 17.1±1.01 mm and 10.3±0.18 mm respectively and in the mid-third the palatine tonsil 10.7±0.12 mm; the distance from the internal carotid artery to the upper and low poles of the palatine tonsil amounted to 14.5±0.84 mm and 16.8±0.77 mm respectively while that to the mid-third of the palatine tonsil was 15.3±0.07 mm. The branches of the external carotid artery feeding the palatine tonsils are the most frequent sources of bleedings; the following measurements were obtained: the maxillary artery 16.4±0.43 mm (17.4%) - the upper pole 9.6±0.02 mm (46.2%), the mid-third of the palatine tonsil 18.5±0.74 mm (29.5%) - the lower pole; the lingual artery 4.7±0.02 mm (6.8%) - the mid-third of the palatine tonsil, 6.2±0.82 mm (56.8%) - the lower pole; facial artery: 4.2±0.01 mm (0.76%) - the mid-third of the palatine tonsil; the occipital artery 25.6±0.12 mm (19%) - the upper pole; 14.8±0.11 mm (18.9%) - the mid-third of the palatine tonsil 9.56±0.12 mm (3.8%) - the lower pole; the tonsillar artery 1.88±0.01 mm (9.8%) - the upper pole; 2.51±0.01 mm (23%) - the mid-third of the palatine tonsil; 2.12±0.01 mm (11%) - the lower pole. The distance from the internal jugular vein to the capsule of the palatine tonsils in the region of the upper pole of the palatine tonsil was 28.3±1.01 mm, in the lower pole region 26.6±1.54 mm, and in the region of the mid-third of the palatine tonsil 22.7±1.24 mm. It is concluded that the results of the present study may be useful for the planning of the surgical strategy for the treatment of the patients presenting with chronic tonsillitis and for the prevention of hemorrhagic complications of tonsillectomy.

Ultrastructure of the human palatine tonsil and its functional significance

The human palatine tonsils represent a mucosa-associated lymphoid tissue with a significant function in mucosal protection against alimentary and airborne pathogens. The ultrastructure of different morphological compartments in the human palatine tonsil was studied in eighteen tonsils obtained from the patients who had undergone elective tonsillectomy due to chronic tonsillitis. The tonsillar specimens were analyzed by scanning and transmission electron microscopy. The results showed the presence of tight junctions between superficial epithelial cells of the oropharyngeal tonsillar surface. The crypt epithelium is a sponge-like structure infiltrated by non-epithelial cells, mostly lymphocytes, and is characterized by the presence of small pores - microcrypts occupied by large microvillus cells and/or lymphocytes. Antigen-presenting Langerhans cells with typical intracytoplasmic Birbeck granules were also found in the crypt epithelium. The lymphoid follicles are composed of lymphocytes and two types of non-lymphoid follicular cells: small fibroblast-like cells and large cells, morphologically consistent with antigen-bearing follicular dendritic cells or macrophages. The interfollicular areas consisted of a dense network of reticular cells and reticular fibers; many lymphocytes were interspersed between the reticular fibers. In addition to arterioles and high endothelial venules in the interfollicular lymphoid tissue, some fenestrated capillaries were seen intraepithelially and subepithelially. The complex ultrastructure of the human palatine tonsil provides a microenvironment necessary for antigen uptake, antigen processing and immune response.

[Peculiarities of blood supply of palatal tonsils and the potential risk of hemorrhage during tonsillectomy: the literature review and case report]

The present review encompasses the publications concerning peculiarities of blood supply of palatal tonsils, the frequency and variants of the anomalous structure of internal carotid artery. Analysis of the literature data has shown that the anomalous vascular structure is one of the important risk factors of the development of intra- and postoperative hemorrhage, besides redundant blood supply of the oropharynx, inflammatory changes in the tissue of tonsils and peritonsillar region. Special attention is given to the peculiarities of diagnostics of such conditions. The emphasis is laid on the importance of timely diagnostics of the anomalous structural changes in the main vessels of the neck prior to the surgical intervention on the pharynx. The analysis of the anomalous structure of internal carotid artery is presented.

Evaluation of microvascular density in inflammatory lesions and carcinoma of palatine tonsil

The tonsil carcinoma with squamous cells seems to be one of the neoplastic lesions with a growing incidence worldwide, even in those geographical areas where the smoking incidence has been reduced. In the disease etiopathogenesis, more factors are incriminated. Among these, the most frequently mentioned are smoking, alcohol consumption and the infection with the Human Papilloma Virus. Among the morphological modifications incriminated for the tumoral appearance and development, there is also included the angiogenesis process that involves the apparition of new blood vessels out from the pre-existent ones, vessels that bring a plus of oxygen and nutritive substances for the tumoral cells. Taking into consideration the fact that the tumoral process is most often accompanied by an inflammatory reaction, in our study we also determined the microvascular density in the carcinoma with squamous cells in the palatine tonsil and in chronic tonsillitis, compared to the vascular density in normal tonsil stroma. We quantified the reaction of the mast cells in the stroma of the two types of lesions, too. The microvascular density in the carcinoma with squamous cells in the palatine tonsil was a lot greater than the microvascular density in chronic tonsillitis. The maximum number of blood vessels in tumoral lesions as well as their area, quantified through the "hot spot" technique on the surface unit, was around two times greater than in chronic tonsillitis. The number of mast cells was significantly larger in chronic tonsillitis and in tonsil carcinoma, too, but the reaction of these cells in the inflammatory affections was more intense than in the neoplastic lesions.

Severe delayed posttonsillectomy haemorrhage due to a pseudoaneurysm of the lingual artery

A 3.5-year-old child is presented with severe, recurrent haemorrhages after a tonsillectomy. The haemorrhages were caused by a pseudoaneurysm of the lingual artery, which was visualised more than 2 weeks postoperatively by angiography. The pseudoaneurysm was successfully embolised by coils. Coiling is an adequate therapeutic option for severe posttonsillectomy haemorrhage due to arterial damage.

Tonsillar haematoma presenting as a large oropharynx mass caused by toothbrush trauma

A 43-year-old man was referred urgently by his GP with a large mass at the back of his throat. The patient had complained of a mild foreign body sensation for the past 3 days, but was distraught to see the mass in the mirror while he was flossing. On further questioning, he recalled brushing his teeth too vigorously and having injured himself. He reported spitting out some blood into the sink but not being unduly distressed. He was a non-smoker and was had no significant past medical history.

On examination, there was a 3 cm smooth mass in the right orophapryx (Figure 1). The mass was soft and attached to the right tonsil via a pedicle. Flexible nasendoscopy was normal and there was no evidence of airway obstruction by mass effect. Under local anaesthesia, the mass was removed with the use of a snare. Full blood count and coagulation studies were entirely normal. Follow-up outpatient clinic at 4 weeks was unremarkable. The tonsillar remnant had healed completely and there was no suspicion of any underlying pathology. Histopathology was consistent with that of infarcted tonsillar tissue.

A review of porcine tonsils in immunity and disease

The porcine tonsils are a group of lymphoepithelial tissues located at the common openings of the gastrointestinal and respiratory tracts. The tonsils participate in a variety of functions involving innate, cellular and humoral immunity at the local and systemic levels. Among these immunological functions is the continuous surveillance for the presence of foreign antigens at the openings of the gastrointestinal and respiratory tracts. Within the pig, the movement of lymphocytes, cytokines and chemotactic molecules from the tonsils to other lymphoid organs confers immunity to other portals of pathogen entry and facilitates an efficient and rapid systemic immune response. In spite of the immunological nature of the tonsils, some microorganisms have acquired adaptations that allow them to circumvent the tonsillar immune defenses and utilize the tonsils as a site of entry, replication and colonization. Several bacterial and viral pathogens persist asymptomatically within the tonsils, making identification of asymptomatic carrier animals difficult in disease control and/or pathogen elimination. This paper reviews the current information on the anatomy, immunology and pathobiology of porcine tonsils and discusses the tonsils as a site of pathogen entry, replication and colonization using Salmonella spp., classical swine fever virus and porcine reproductive and respiratory syndrome virus as examples.

Plasticity of endothelial cells: rapid dedifferentiation of freshly isolated high endothelial venule endothelial cells outside the lymphoid tissue microenvironment

Endothelial cells display remarkable heterogeneity in different organs and vascular beds. Although many studies suggest that tissues “speak” to endothelial cells, endothelial cell diversity remains poorly characterized at the molecular level. Here, we describe a novel strategy to characterize tissue-specific endothelial cell phenotypes and to identify endothelial cell genes that are under the control of the local microenvironment. By comparing post-capillary high endothelial venule endothelial cells (HEVECs), freshly isolated from human tonsils without any cell culture step, with HEVECs cultured for 2 days, we found that HEVECs rapidly lost their specialized characteristics when isolated from the lymphoid tissue microenvironment. Striking changes occurred as early as after 48 hours, with complete loss of the postcapillary venule–specific Duffy antigen receptor for chemokines (DARCs) and the HEV-specific fucosyltransferase Fuc-TVII. DNA microarray analysis identified several other candidate HEV genes that were rapidly down-regulated ex vivo, including type XV collagen, which we characterized as a novel, abundant HEV transcript in situ. Together, our results demonstrate that blood vessel type–specific and tissue-specific characteristics of endothelial cells are under the control of their microenvironment. Therefore, even short-term primary cultures of human endothelial cells may not adequately mimic the differentiated endothelial cell phenotypes existing in vivo.

Adrenergic and acetylcholinesterase-positive innervation of palatine tonsils in mammals

Innervation of human, feline and rabbit palatine tonsils was investigated. Adrenergic nerve components were visualized by formaldehyde-induced fluorescence of catecholamines and 5-HT, or by glyoxylic acid fluorescence, whereas acetylcholinesterase (AChE)-positive nerve structures were demonstrated by the direct thiocholine method. The largest density of adrenergic and AChE-positive nerve profiles was found in the adventitia of arterial branches in the fibrous capsula and septa, mainly in the form of periarterial nerve plexuses of different density. Fine nerve fibres lined the wall of small arteries which penetrated into extrafollicular lymphoid tissue and marginal layers of follicles. It is concluded that there are significant species-specific differences related to density, nature and topographic relations of adrenergic and AChE-positive nerve fibres in the various structural parts of palatine tonsils.

[Atypical course of cervical vessels--2 case reports]

BACKGROUND

The atypical course of cervical arteries can be reason for vascular complications including stroke and persistent neurological deficits in surgery in the cervical region.

METHODS

Computed tomography and magnetic resonance imaging including angiographic procedures such as contrast enhanced magnetic resonance angiography are suitable to detect atypical course of cervical arteries.

RESULTS

The two cases demonstrate rare variants of atypical course of cervical arteries detected by computed tomography and magnetic resonance imaging including contrast enhanced magnetic resonance angiography. The knowledge of these variants is important for planning of surgical intervention.

CONCLUSIONS

Modern imaging techniques such as computed tomography and magnetic resonance imaging including contrast enhanced magnetic resonance angiography should be used for detection of suspected variants in the course of cervical arteries. The relevant structures and the abnormalities can be clearly defined.

Blood vascular architecture of the palatine tonsil in the musk shrew (Suncus murinus): scanning electron microscopic study of corrosion casts

The musk shrew, Suncus murinus, is one of the primitive mammals and has a pair of palatine tonsils. In the present study, we investigated the blood microvascular architecture of the tonsil in this animal by scanning electron microscopy of corrosion casts. The paranodular arterioles entered the lymph nodule to form a coarse capillary plexus within the nodule. Some of the arterioles reached the dome region to give rise to a fine meshwork of dome subepithelial capillaries. This dome subepithelial capillary network did not show any hairpin or switch-back patterns, as seen in human and rabbit tonsils. Both of the nodular and dome capillaries were drained into the postcapillary venules in the periphery of the nodular or the paranodular region. On the surface of these cast venules, oval-shaped indentations were seen corresponding to the luminal surface of the high endothelial venules. These venules were collected into the large vein at the bottom of the tonsil. The blood vascular architecture of the musk shrew tonsil is basically the same as those of other mucosa-associated lymphoid tissues in mammals.

CT angiography before embolization for hemorrhage in head and neck cancer

We present a patient with advanced head and neck carcinoma and a bleeding pseudoaneurysm diagnosed by means of CT angiography; this was not apparent on conventional digital subtraction angiograms. The information provided by CT angiography facilitated rapid identification of the pseudoaneurysm and treatment with embolization. CT angiography may be helpful before embolization in cases of hemorrhage in head and neck cancer.

Route of lymphocyte migration through the high endothelial venule (HEV) in human palatine tonsil

Eleven palatine tonsils were collected from subjects who underwent tonsillectomy in Christian Medical College Hospital and the route of migration of lymphocytes through the high endothelial vessel was studied under EM. In the interendothelial route, migration of a lymphocyte through HEV wall began with the adhesion of a lymphocyte to the surface of endothelial cells by means of a short cytoplasmic projection in the vicinity of intercellular space. The projection extended into the cleft between adjacent endothelial cells. The lymphocyte migrated through HEV by diapedesis. After the lymphocyte had traversed the interendothelial space, it occupied the subendothelial space. In the transendothelial route, migration of a lymphocyte through HEV was initiated by adherence of the lymphocyte to the endothelial cell. The adherent lymphocyte compressed or invaginated into the cytoplasm of the endothelial cell, entered the endothelial cell, was completely enclosed within the endothelial cell cytoplasm, and emerged from the endothelial cell to occupy the subendothelial space. Evidence is presented from static transmission electron microscopic pictures for the migration of lymphocytes by both interendothelial and transendothelial routes through the high endothelial venule.

Endoscopic ligature of the sphenopalatine artery for severe posterior epistaxis

OBJECTIVE

To present our experience with endoscopic ligature of the sphenopalatine artery in the treatment of severe posterior epistaxis of patients who had previously undergone conservative procedures.

METHODS

Eleven patients with severe posterior epistaxis were treated during a 25-month period with an endoscopic ligature of the sphenopalatine artery. The basic principle of the surgical technique is to identify the branches of the sphenopalatine artery through an endoscopic endonasal approach and to apply a titanium clip under direct vision.

RESULTS

The endoscopic ligature of the sphenopalatine artery was performed unilaterally in 10 patients and bilaterally in 1 patient, with a total of 12 ligatures. It was possible to identify the sphenopalatine artery in all cases with a successful outcome using this surgical technique alone.

CONCLUSION

Endonasal endoscopic ligature of the sphenopalatine artery has been an effective surgical technique for treating severe posterior epistaxis.

Endovascular treatment of hemorrhage after tonsillectomy in children

SUMMARY

Endovascular therapy for hemorrhage after tonsillectomy or adenoidectomy is an important adjunct to the definitive treatment of this life-threatening occurrence. We report two cases of hemorrhage after tonsillectomy and/or adenoidectomy and describe the endovascular management of this complication in children.

Lingual artery embolization for severe and uncontrollable postoperative tonsillar bleeding

We performed emergent angiography of the external carotid artery to evaluate a patient who experienced uncontrollable oropharyngeal bleeding 3 days following an adenotonsillectomy. Angiography demonstrated a left lingual artery disruption and hemorrhage. We then performed a coil embolization of the left lingual artery, which immediately halted the hemorrhage. We conclude that coil embolization is a rapid and effective strategy for the management of massive, uncontrollable postoperative tonsillar bleeding.

Role of transforming growth factor beta1 in microvascular endothelial cell apoptosis associated with thrombotic thrombocytopenic purpura and hemolytic-uremic syndrome

Primary human microvascular endothelial cells (MVEC) of restricted lineage undergo apoptosis when exposed to plasma from patients with thrombotic thrombocytopenic purpura (TTP) and sporadic hemolytic-uremic syndrome (HUS). This reflects the pathology and tissue distribution of lesions in vivo. As extracellular matrix (ECM) is critical to MVEC survival, and cytokines which regulate ECM, such as transforming growth factor (TGF)-beta1, have been reported anecdotally to be altered in TTP/HUS, we examined the role of TGF-beta1 and two ECM proteins, fibronectin and thrombospondin (TSP), in these disorders. Levels of active TGF-beta1 were elevated in acute but not convalescent phases of TTP/sporadic HUS, as well as TTP associated with human immunodeficiency virus infection and use of the anti-platelet drug ticlopidine. MVEC from tissues susceptible to TTP-mediated apoptosis showed little active TGF-beta1 production when exposed to TTP plasmas. In contrast, pulmonary MVEC and large-vessel EC, which are resistant to TTP-linked pathology, showed marked induction of TGF-beta1 following TTP plasma exposure. Exogenous TGF-beta1 suppressed TTP plasma-mediated apoptosis in susceptible MVEC in association with blockade of cell entry into S phase. Soluble TSP, devoid of detectable bound TGF-beta1, had a similar effect, which paralleled its ability to induce TGF-beta1 production in MVEC. In vivo, TSP deposition was diminished markedly in involved tissues of TTP patients. These data highlight the role of TGF-beta1 and ECM in TTP and suggest that differential production of TGF-beta1 by MVEC may play a role in their sensitivity or resistance to TTP/sporadic HUS-mediated apoptosis in vitro and in vivo.

Differences in lymphocyte subsets in the wall of high endothelial venules and the lymphatics of human palatine tonsils

Lymphocyte trafficking plays a critical role in disseminating specifically primed lymphocytes all over the body. Most concepts on the interaction of adhesion molecules on lymphocyte subsets and specialized endothelia such as those in high endothelial venules (HEV) are based on animal experiments as kinetic studies cannot be performed in humans. We therefore characterized lymphocyte subsets in the wall of HEV and in the lumen of lymphatics of 18 human palatine tonsils by immunohistology. All subsets studied were found in the wall of HEV (% of lymphocytes): 32% CD20+, 50% CD3+, 14% CD4+, 32% CD8+ and also 21% CD45RA+ and 39% CD45RO+. In the lymphatics, used to indicate lymphocytes emigrating from the tonsils, a different composition was found; e.g. many more T cells and three times more CD45RA+ than RO+ lymphocytes. Thus, HEV are not a selective entry site nor lymphatics an exit for specific lymphocyte subsets only, at least in these tonsils with chronic stimulation.

Culture characterization of differentiated high endothelial venule cells from human tonsils

High endothelial venules (HEV) are specialized vessels that support abundant lymphocyte emigration from peripheral blood into secondary lymphoid organs. HEV endothelial cells (HEVEC) exhibit particular structural and functional features, including secretion of the HEV-specific extracellular matrix protein hevin and an array of uniquely glycosylated counter-receptors for L-selectin expressed on lymphocytes. These ligands are collectively called the peripheral lymph node addressin (PNAd), originally defined by the monoclonal antibody MECA-79. PNAd expression was used to purify HEVEC by positive immunoselection from enzyme-digested human tonsils after negative immunoselection for other cells. Purified HEVEC maintained secretion of hevin and homogenous expression of intercellular adhesion molecule (ICAM)-1 (CD54), ICAM-2 (CD102), and CD31, at high levels following 8 days in culture. Expression of functional PNAd was maintained during the first 4 to 5 days of culture but decreased gradually and disappeared on day 8, while the expression of CD34 remained strong. However, the CD34 glycoform shifted toward the in situ phenotype of flat-walled vessels, suggesting that the observed loss of L-selectin binding determinants and MECA-79 antigen was due to down-regulation of the glycosyl- and sulfo-transferases essential for their expression. Our rapid and reproducible method to establish HEVEC cultures provides a useful mechanistic tool for identification of the factors that induce and maintain the HEV phenotype, as well as a source for isolation of HEV-specific genes.

Endoglin (CD 105) expression in human lymphoid organs and placenta

Endoglin (CD 105) is a cell surface antigen widely expressed on vascular endothelium, syncytiotrophoblast, some tissue macrophages, certain culture cells (including early leukemic B-lineage) and some endothelial cell lines. Though its relation to the transforming growth factor-beta (TGF-beta) receptor system is well documented, its function and detailed pattern of expression still remain to be clarified. We examined the differential tissue distribution of endoglin in human lymphoid organs and placenta with several anti-CD 105 monoclonal antibodies (mAbs) using an indirect immunoperoxidase technique, and performed semi-quantitative measurements using an image-analyzing system for comparison. Arterial, venous and capillary endothelia in these organs were reactive with anti-CD 105 mAbs at varying intensities. Interestingly, a distinctly stronger staining pattern was observed in the high endothelial venules (HEVs) which may indicate a special role for endoglin in lymphocyte trafficking. Syncytiotrophoblast expressed endoglin strongly on their apical cell membrane. Extravillous trophoblasts at certain locations selectively expressed endoglin on their cell membranes, suggesting a special role for this surface antigen during trophoblast differentiation.

Massive primary hemorrhage during tonsillectomy from a large venous varicosity

The internal jugular vein is derived embryologically from the anterior cardinal veins. Developmental abnormalities may result in a cavernous venous varicosity, which may be the cause of massive primary hemorrhage during tonsillectomy. An index of suspicion is required for diagnosis, which may be confirmed by retrograde venography techniques.

Enhanced expression of CD31 and CD54 on tonsillar high endothelial venules in IgA nephropathy

Abnormalities in the partition of IgA- and IgG-producing cells in the tonsils of patients with IgA nephropathy have been suggested to result from a dysregulation of cell trafficking and homing through high endothelial venules in this lymphoid tissue. In order to document such adhesion anomalies, we used the 36 monoclonal antibodies of the cell adhesion molecules subpanel of the Fifth International Workshop on Leukocyte Differentiation Antigens on frozen sections of tonsils from 10 patients and 15 controls. This allowed us to describe the partition of cell adhesion molecules in human tonsils and to demonstrate a significant enhancement of CD31 and CD54 expression on high endothelial venules of tonsils from patients with IgA nephropathy. These observations are in keeping with the hypothesis of an increased lymphocyte recruitment in tonsils in this disease.

Different forms of human vascular adhesion protein-1 (VAP-1) in blood vessels in vivo and in cultured endothelial cells: implications for lymphocyte-endothelial cell adhesion models

Vascular endothelium plays a pivotal role in controlling leukocyte extravasation from the blood into the tissues. Vascular adhesion protein-1 (VAP-1) is a novel endothelial cell molecule which mediates lymphocyte binding to the vascular lining (Salmi, M., and Jalkanen, S., Science 1992. 257:1407). In this study, we analyzed endothelial cell type-specific differences of VAP-1. In vivo, VAP-1 is a 90/170-kDa molecule which is mainly expressed on the lumenal surface and in cytoplasmic granules of peripheral lymph node-type postcapillary venules (high endothelial venules, HEV). In tonsil HEV, VAP-1 is modified with abundant sialic acids. VAP-1 is also detectable in the cytoplasm of human umbilical vein endothelial cells (HUVEC) and in an endothelial cell hybrid EaHy-926, although both cell types lack detectable surface VAP-1. Cultured endothelial cells do not express MECA-79-defined peripheral lymph node addressins either. VAP-1 was not translocated onto the endothelial cell surface after stimulation with multiple cytokines, mitogens or secretagogues which induced expression of other known endothelial adhesion molecules. Biochemical analyses revealed that VAP-1 is a approximately 180-kDa protein in these endothelial cell types. Digestions with neuraminidase, O-glycanase and N-glycanase, as well as treatment of cells with tunicamycin and benzyl-N-acetylgalactosaminide, did not alter the molecular mass of VAP-1 in EaHy-926. Pulse-chase experiments showed that VAP-1 is directly synthesized as a 180-kDa molecule without any detectable precursors. Thus, in cultured endothelial cells, VAP-1 is a 180-kDa protein which is devoid of post-translational modifications, and in particular, lacks the sialic acids crucial for the function of VAP-1 in tonsil vessels. Notably, the endothelial cell types commonly used as a model in studying lymphocyte-endothelial cell interactions lack surface expression of VAP-1 and peripheral node addressins, and hence are inherently of limited use in analyses of the initial adhesion of lymphocytes.

[A study on the tonsil with focal infections--with special reference to the newly devised tonsillar cryptscope and the architecture of vessels in crypts]

It is well known that inflamed human palatine tonsils have many surface crypts showing characteristic lymphoepithelial symbiosis, which play an important role in immune response. The cryptepithelia are rich in blood vessels. This proliferation of blood vessels is said to be the initiation of various kinds of immune responses. We devised a tonsillar cryptscope in order to observe the tonsillar crypt. Scopy with the cryptscope confirmed seven characteristic types of capillary vessels. The cryptscopic figures showed different patterns in tonsillar diseases such as hypertrophic tonsil, recurrent tonsillitis and tonsil with focal infection (palmoplantar pustulosis and psoriasis vulgaris). In this study the significances of tonsillar cryptscopic figures were investigated through the study of three dimensional structures of blood vessels and immuno-histology. In order to understand the structure of capillary vessels in details, human palatine tonsils were studied using corrosion casting techniques with a scanning electron microscope. Horseshoe type capillary vessels corresponded to the curved capillary vessels in the epithelium. This type of capillary vessel was observed in the epithelia covering the interfollicular area. The tonsillar blood vessels, along with closely related substances in the epithelium and the parenchyma, were immuno-histologically examined. Where the lymphocytes had densely infiltrated the epithelium, the basement membrane became thickened and often disrupted; the endothelial cells were also enlarged. Adrian et al reported that lymphocytes invaded from the capillary vessels within the epithelia. Thus it was suggested that the horseshoe type was related to lymphocyte invasion of the epithelia.(ABSTRACT TRUNCATED AT 250 WORDS)

Cytokine-enhanced expression of glycoprotein Ib alpha in human endothelium

Platelet glycoprotein Ib is a major platelet membrane protein composed of two disulfide-linked chains, termed the alpha and beta chains. The larger alpha chain (GpIb alpha), a platelet receptor for von Willebrand factor, plays a major role in mediating platelet adhesion to the subendothelium. Our laboratories have previously reported synthesis of a protein in human endothelial cells that is immunoprecipitated with polyclonal and monoclonal antibodies to platelet GpIb alpha. Lopez et al. (Lopez, J. A., Chung, D. W., Fujikawa, K., Hagan, F. S., Papayannopoulou, T., and Roth, G. J. (1987) Proc. Natl. Acad. Sci. U.S.A. 84, 5615-5619) have reported the cloning of GpIb alpha from a human erythroleukemia (HEL) cell cDNA library. Using this clone as probe, we have isolated two partial GpIb alpha clones from a human umbilical vein endothelial cell lambda gt11 cDNA library. These clones were localized within HEL-derived GpIb alpha cDNA by sequence and restriction enzyme analysis. Additionally, they detected the same message species in HEL and tonsilar RNA that was detected with the HEL GpIb alpha cDNA. Low level GpIb alpha mRNA expression was detected in cultured human umbilical vein endothelial cells, which was increased by treatment of the cells with tumor necrosis factor-alpha. This effect was enhanced by pretreatment with interferon-gamma. Additionally, localization of GpIb alpha in endothelium of fresh tonsilar tissue was demonstrated by immunohistochemistry and in situ hybridization. GpIb alpha may play a role in mediating platelet or other effector cell adhesion to activated endothelium.

Immunoglobulin deposits in diabetic microangiopathy. Observations in autopsy materials

Non-enzymatic glycosylation of vascular wall collagen is considered to be most important in the pathogenesis of diabetic microangiopathy, and glycosylated collagens are reported to bind immunoglobulins in vivo. We investigated the occurrence of IgG or IgM deposits in the microvasculature of certain organs of diabetics using routine autopsy materials. Glomerular capillary basement membrane/endothelium was often positive for IgM in diabetics. Endothelial cells of glomerular capillaries were positive for HLA-DR in 6 of 16 diabetics and in 2 of 11 controls. This was associated with IgM or IgG deposits in 5 cases. In the esophagus and/or tongue of diabetics, IgG was frequently deposited in the microvasculature. In total, IgG deposits were found in 13 of 16 diabetics, either in the esophagus or the tongue, but in only 3 of 16 controls. The difference was significant at p less than 0.005. These observations suggest that deposition of immunoglobulins is a component of diabetic microangiopathy. Differences in expression of HLA-DR in glomeruli between diabetics and non-diabetics remain to be explored.

[Catarrhal prodromes and pharyngotonsillar hyperemia in acute bacterial meningitis]

In the pathogenesis of acute bacterial meningitis (ABM), the direct entry of the responsible microorganism at the level of the upper respiratory tract is considered as one of the most important etiopathogenic mechanisms, occasionally presenting catarrhal symptoms in the initial stages of the disease. It appears that upper respiratory tract infections favor the penetrability of certain bacteria, such as N. meningitidis and S. pneumoniae, which constitute the most frequent causes of ABM in our medium. The rhinopharynx is the most usual entry point. The present study was designed to ascertain the frequency of these prodromic signs and symptoms in ABM. The presence of this catarrhal semiology in the days prior to hospital admission was analyzed, in addition to the existence of pharyngotonsillar hyperemia (FTH) at the moment of admission of 250 cases of community-acquired ABM. We believe that these data are of clinical interest, and were not found in the reviewed series.

Ultrastructures of the epithelial basement membrane and the subepithelial capillaries in rabbit palatine tonsils

The ultrastructure of both the epithelial basement membrane and the subepithelial capillaries in rabbit tonsils was investigated using light and transmission electron microscopy of sections, and scanning electron microscopy of alkali-water macerated tissues. The basement membrane of the crypt epithelium was seen to consist of the lamina lucida, lamina densa and lamina fibroreticularis. The lamina fibroreticularis is made up of both fine and thick collagen fibrils. The basement membrane possesses numerous pores (0.5-20 microns in diameter) through which free cells migrate. The basement membrane overlying the follicle protrudes hemispherically towards the crypt lumen, while that over the interfollicular area forms many papillary projections. The capillaries are surrounded by collagen fibrillar sheaths invariably located below the collagen fibrillar sheet of the epithelial basement membrane. The capillaries immediately below the crypt epithelium, including switch-back loops of capillaries in the papillae, are fenestrated sinusoids (20-40 microns in diameter). Plasma cells, lymphocytes and macrophages are numerously gathered around the capillaries. Possible functional relations between these free cells and the fenestrated sinusoids are discussed.

Microvascular organization of human palatine tonsils

We describe the three-dimensional organization of the microvasculature of human palatine tonsils as revealed by the vascular corrosion casting/scanning electron microscope method and light microscopy of sections. The tonsillar arteries travel in the connective tissue septa and give off many branches. They further branch into arterioles which in turn enter the follicle and the interfollicular region. These arterioles, giving off capillaries en route, reach the subepithelial region where they break up into sinusoidal capillaries. The subepithelial capillary network overlying the follicle protrudes hemispherically towards the crypt, while that overlying the interfollicular region has many switch-back loops of capillaries projected towards the crypt. The subepithelial sinusoids gather into the high endothelial venules (HEVs) which, collecting capillaries in the follicle and the interfollicular region en route, course down into the interfollicular region alongside the follicle. The HEVs surround the lateral and basal surfaces of the follicle and ultimately lead into the ordinary veins in the septa. The subepithelial sinusoids seem to be involved in taking up immunoglobulins secreted by plasma cells and any other substances released by lymphocytes and/or macrophages as well as supplying the tissues with necessary oxygen and nutrients. That the HEVs are downstream to the subepithelial sinusoids suggests that some substances which are taken up into the sinusoids and transported to the postcapillary venules induce differentiation of HEVs and maintain them.

[Aneurysms of the lingual artery as a cause of recurrent late hemorrhage following tonsillectomy]

We report on two cases of repeated secondary posttonsillectomy haemorrhage caused by aneurysms of the lingual artery. Comparing our cases with similar cases in the literature we show the typical course of such serious complications. The advantages of an early arteriography for correct diagnosis and the further diagnostic procedure are discussed.

[Hemorrhagic accidents in palatal tonsil surgery]

Here is shown that, even though tonsillectomy is the most frequently performed operation in ORL, it may sometimes cause severe hemorrhaging that could imperil the patient's life if not rapidly and competently dealt with. Tonsil hemorrhaging is favoured by the anatomical situating, tonsils being greatly vascularized, as well as by the specific of the pharyngeal wounds. There are discussed here the cases in the Bistriţa ORL Clinic between 1981-1987.

An architecture of capillary vessels of the palatine tonsils studied by scanning electron microscope--with special references to comparison with the tonsillar cryptscopic images

The three-dimensional structure of capillary vessels in the human palatine tonsil using corrosion casting techniques was investigated and compared to recently developed cryptscopic images. The postcapillary venules and arterioles were distinguishable from the nuclear impressions on their walls. The configuration of vessels around the micropores of crypts is similar to the images from the cryptscope.

Endothelial proliferation in paroxysmal nocturnal hemoglobinuria

Paroxysmal nocturnal hemoglobinuria (PNH) is a disorder of stem cells that is associated with venous thrombosis in multiple organ sites. We present a patient with necrotizing pharyngitis and intestinal infarction who has classic laboratory findings for PNH: positive complement-mediated acid and sucrose hemolysis and absence of decay accelerating factor (DAF) in peripheral blood leukocytes. Histopathologic examination of tissue from tonsil and large bowel demonstrated not only venous thrombosis but unusual proliferation of endothelial cells (papillary endothelial hyperplasia). This has not been described previously. We speculate that the endothelial cell in PNH may share in the defective regulation of complement activity. Venous thrombosis could precipitate or be a consequence of these vascular changes.

Structure of the crypt epithelium in human palatine tonsils

Material from human palatine tonsils from a group of 18 tonsillectomised patients aged 22 months to 8 years was studied by LM, TEM and SEM. Special attention was focused on the structure of the epithelium lining the tonsillar crypts. This is of a dynamic nature in the living organism. In contrast to the stratified squamous epithelium covering the oropharyngeal surface of the tonsil it was often reticulated and invaded by non-epithelial cells. However, it was not uniform throughout. When studied by LM and TEM, adjacent patches of epithelium varied in degree of reticularity. The reticulated epithelium was either covered by a thin layer of squamous cells, or this was disrupted in places where non-epithelial cells passed through. Hence the intact surface, as seen on the SEM, is not a reliable indication of the nature of the underlying structure of the epithelium. Small blood vessels were frequently observed in association with the reticulated epithelium. They formed numerous finger-like projections surrounded by a sleeve of subepithelial connective tissue, and also a fine capillary network within the epithelial thickness. It is proposed that such an organisation of the crypt epithelium offers favourable means for the capturing and processing of antigens by the palatine tonsils.

Measurement of tonsillar blood flow in normal and pathological conditions by the use of the 133Xe clearance technique

By using the 133Xe clearance technique, we measured the blood flow to the human palatine tonsil in 10 normal volunteers, 11 patients with chronic tonsillitis, and 11 with hypertrophic tonsils. We found that the mean blood flow was 30.08 +/- 5.39 ml/ 100 g per min in normal tonsils, 17.06 +/- 3.72 in chronic tonsillitis and 49.50 +/- 9.30 in hypertrophic tonsils. Our results show a statistically significant decrease in blood flow in chronic tonsillitis (P less than 0.01) and a significant increase in hypertrophic tonsils (P less than 0.01) when compared to the normal controls. The difference between the blood flow in chronic tonsillitis and hypertrophic tonsils was also statistically significant (P less than 0.01). In all three groups studied, no statistically significant difference was observed in the blood flow to the right and left tonsils (P greater than 0.05).

Microcrypt extensions of tonsillar crypts

The crypts of human palatine tonsils were examined electron microscopically. The cryptal epithelia contained three types of micropores (termed microcrypt). Type I microcrypts opened between intercellular spaced of the epithelial cells. Free cells were observed in the micropores. Type II microcrypts opened near the center of a cryptal epithelial cell. Type III microcrypts appeared after "specialized epithelial cells" degenerated and fell off. Many mature plasma cells are attached to the walls of the sinusoidal vessels in the lower boundary zone of the epithelium and subepithelial layer. Lymphocytes were observed migrating from the postcapillary venules of the subepithelial zone. The findings indicate that the microcrypts are probably orifices for tunnel-like passages of free cells and that they are located in the walls of the tonsillar crypts. The lymphocytes in the passages perhaps come from lymphoid tissues in the subepithelial layer and postcapillary venules, and the antibodies produced in the cryptal epithelia of the palatine tonsils may contribute to humoral immunity.

Blood supply in the developing and post natal rat soft palate

Foetal and post natal rats were perfused with a carbon suspension and cleared in methyl salicylate to display the blood supply of the developing and formed hard and soft palates. The arterial blood supply of the soft palate was from the pharyngeal artery, a branch of the pterygopalatine artery; and from the tonsillar artery, a branch of the external maxillary artery. The pharyngeal artery could be recognised from 14 days post insemination and reached its adult configuration on the 17th day p.i. The tonsillar artery was seen from the 18th day. In the hard palate the blood supply was as described by other authors.