Historical Profiling of Dry Eye Patients - Potential Trigger Factors and Comorbidities.

PURPOSE: Dry eye syndrome (DES) is one of the most common diseases of the ocular surface. Affected persons suffer from different subjective complaints, with sometimes severe impairment in the quality of life. The aetiology and pathogenesis are multifactorial, multifaceted, and not yet fully understood. The present study is intended to provide deeper insights into possible triggering factors and correlating comorbidities. MATERIALS AND METHODS: In German ophthalmological practices, 306 persons (174 women, 132 men, age: 18 - 87 years) were interviewed by questionnaire on concomitant diseases and possible further triggering factors. DES was diagnosed by an ophthalmologist in 170 cases. The statistical comparative analysis between persons with and without DES was carried out using the chi-squared test (SPSS statistical software). RESULTS: DES occurred with significantly (p < 0.05) increased frequency in women over 40 years of age, as well as in persons exposed to screen work, air conditioning, persons with chronic ocular inflammation, myomas (hysterectomy), dry skin, arterial hypertonicity in need of medication, cardiac arrhythmias, fatty liver, gastric ulcer, appendicitis, cholecystectomy, depression, hyperlipidaemia, hyperuricaemia, osteoporosis, and nephrolithiasis. CONCLUSION: Some of the known comorbidities and DES risk factors, e.g., computer work or depression, were confirmed. In contrast, the higher prevalence of hyperlipidaemia, hyperuricaemia, osteoporosis, nephrolithiasis, and fibroids among DES patients has not previously been reported. Additional studies should be performed on causal connections between DES and specific comorbidities.

Inverse identification of region-specific hyperelastic material parameters for human brain tissue.

The identification of material parameters accurately describing the region-dependent mechanical behavior of human brain tissue is crucial for computational models used to assist, e.g., the development of safety equipment like helmets or the planning and execution of brain surgery. While the division of the human brain into different anatomical regions is well established, knowledge about regions with distinct mechanical properties remains limited. Here, we establish an inverse parameter identification scheme using a hyperelastic Ogden model and experimental data from multi-modal testing of tissue from 19 anatomical human brain regions to identify mechanically distinct regions and provide the corresponding material parameters. We assign the 19 anatomical regions to nine governing regions based on similar parameters and microstructures. Statistical analyses confirm differences between the regions and indicate that at least the corpus callosum and the corona radiata should be assigned different material parameters in computational models of the human brain. We provide a total of four parameter sets based on the two initial Poisson's ratios of 0.45 and 0.49 as well as the pre- and unconditioned experimental responses, respectively. Our results highlight the close interrelation between the Poisson's ratio and the remaining model parameters. The identified parameters will contribute to more precise computational models enabling spatially resolved predictions of the stress and strain states in human brains under complex mechanical loading conditions.

Polytetrafluoroethylene (PTFE) suture vs fiberwire and polypropylene in flexor tendon repair.

BACKGROUND: In this study, we evaluate the value of novel suture material based on monofilamentous-extruded polyfluoroethylene (PTFE) compared to polypropylene (PPL) and Fiberwire (FW). MATERIALS AND METHODS: 60 flexor tendons were harvested from fresh cadaveric upper extremities. 4-0 sutures strands were used in the PPL, FW and PTFE group. Knotting properties and mechanical characteristics of the suture materials were evaluated. A 4-strand locked cruciate (Adelaide) or a 6-strand (M-Tang) suture technique was applied as core sutures for a tendon repair. Two-way ANOVA tests were performed with the Bonferroni correction. RESULTS: Stable knotting was achieved with 5 throws with the PPL material, 7 throws for FW and 9 throws for PTFE. In the PPL group, linear tensile strength was 45.92 ± 12.53 N, in the FW group 80.11 ± 18.34 N and in the PTFE group 76.16 ± 29.10 N. FW and PTFE are significantly stronger than PPL but show no significant difference among each other. Similar results were obtained in the subgroup comparisons for different repair techniques. The Adelaide and the M-Tang knotting technique showed no significant difference. CONCLUSION: Fiberwire showed superior handling and knotting properties in comparison to PTFE. However, PTFE allows easier approximation of the stumps. In both, M-Tang and Adelaide repairs, PTFE was equal to FW in terms of repair strength. Both PTFE and FW provide for a robust tendon repair so that early active motion regimens for rehabilitation can be applied.

[Is there a new salivary gland? - Rather not!] / Gibt es eine neue Kopfspeicheldrüse? ­ Eher nicht!

In October 2020, the lay press, but also some medical journals and websites reported the putative discovery of a new salivary gland in the nasopharynx based on prostate-specific membrane antigen positron emission tomography computed tomography (PSMA-PET/CT) examinations. As an interdisciplinary group from the fields of anatomy, pathology, nuclear medicine and otorhinolaryngology, we come to the view that an accumulation of minor salivary glands has been described here. Minor salivary glands in the nasopharynx and in the peritubar region have been described at least since 1866. The current description in PSMA-PET/CT does not justify the definition of a new, independent salivary gland. The PSMA-PET/CT could, however, be suitable to better protect salivary glands in the nasopharynx when planning radiation therapy. This should be evaluated in clinical trials.

Altered Surfactant Protein Expression in Primary Acquired Nasolacrimal Duct Obstruction.

PURPOSE: To investigate the presence and distribution patterns of 6 surfactant proteins in lacrimal drainage tissues of patients with primary acquired nasolacrimal duct (NLD) obstruction. METHODS: The presence and distribution of surfactant proteins (SP)-G and SP-H was first assessed in normal cadaveric lacrimal systems. The study was then performed in 10 samples of lacrimal sac and the respective NLDs obtained from patients suffering from primary acquired NLD obstruction who underwent either a dacryocystorhinostomy or a dacryocystectomy. The lacrimal sac samples were further divided into fundus and body, soon after their removal. Immunohistochemical labeling was performed for assessing the presence and distribution of SPs: SP-A, SP-B, SP-C, SP-D, SP-G/SFTA2, and SP-H/SFTA3. The results were then scored as positive or negative and the distribution pattern, if any, within the lacrimal sac and NLDs was assessed. Human lung tissues were used as controls. RESULTS: SP-H was demonstrated in the lining epithelia of the normal lacrimal drainage systems, whereas SP-G was uniformly negative. Immunohistochemical labeling revealed wide variations in the staining patterns of different SPs in different regions of the lacrimal sac and the NLD. SP-D and SP-G revealed uniformly negative immunoreactivity. Variable staining patterns were also noted between the superficial and basal layers of the lining epithelia. However, the goblet cells and intraepithelial mucous glands did not express any of the SPs. CONCLUSIONS: This study provides a proof of principle for the presence of SP-H and absence of SP-G in the normal lacrimal drainage systems. In cases of primary acquired nasolacrimal duct obstruction, there were alterations or loss of SP expression in the lining epithelia of the lacrimal sac and NLDs, reflecting their possible role in the etiopathogenesis of primary acquired nasolacrimal duct obstruction.In cases of primary-acquired nasolacrimal duct obstruction, the expression of multiple surfactant proteins was either deranged or lost in the lining epithelium of the lacrimal sac and nasolacrimal ducts.

Recommendations of the working group of the Anatomische Gesellschaft on reduction of formaldehyde exposure in anatomical curricula and institutes.

The practice of human and veterinary medicine is based on the science of anatomy and dissection courses are still irreplaceable in the teaching of anatomy. Embalming is required to preserve body donors, for which process formaldehyde (FA) is the most frequently used and well characterized biocidal substance. Since January 2016, a new occupational exposure limit (OEL) for FA of 0.37mg/m3 issued by the European Committee on Hazardous Substances is obligatory since FA has been classified as a human 1B carcinogen. The anatomical institutes in the German-speaking region are called upon to consolidate efforts to reduce use of FA in anatomical curricula and body donations. As a result, the Anatomische Gesellschaft (AG) has formed a "Working Group for Reduction of Formaldehyde Exposure in Dissection Courses" tasked with discussion and recommendation of measures to reduce FA. Based on the assessment of the Working Group, the AG has issued an official opinion to the effect that, at this point in time, embalming of body donors without FA completely is not feasible. Therefore, a combination of approaches are to be used to reduce FA exposure, including technical and structural (architectural) adaptations, modification of protocols for fixation and preservation as well as organizational measures. One structural measure considered unavoidable is the integration of air supply and exhaust of individual dissecting tables into the ventilation system of the anatomy building. To embalm human body donors, intra-arterial perfusion fixation with up to 4% FA and a total fluid volume of 150mL/kg body weight will suffice. For animals where body weights and biology of bodies vary widely (i.e. special needs of fixation for ruminants, large animals as horses) perfusion fixation with up to 4% FA and a quantity of fixative solution of 10-15% of the body weight may be required. Preservation of body donors in storage (immersion) can be done with 40% ethanol or in a full bath preservation containing up to 2% FA. Corpse humidification in the dissecting room is possible with 2% phenoxyethanol, in each case without FA. In veterinary anatomy, microbiological burden is often higher and therefore might lead to a need of FA in long-time storage. Compliance with the current OEL in all institutes would appear to be feasible in combination with various organizational measures.

Evaluation of surfactant proteins A, B, C, and D in articular cartilage, synovial membrane and synovial fluid of healthy as well as patients with osteoarthritis and rheumatoid arthritis.

OBJECTIVE: Surfactant Proteins (SPs) are well known from lung and form, along with phospholipids, a surface-active-layer at the liquid-air-interface of the alveolar lining. They play a major protective role by lowering surface tension, activating innate and adaptive immune defense at the lung mucosal interface, especially during infection. We analyzed the regulation of SPs in human and mouse articular chondrocytes, synoviocytes, and synovial fluid under healthy and inflammatory conditions, as well as in tissues of patients suffering from osteoarthritis and rheumatoid arthritis. METHODS: Immunohistochemistry, RT-PCR, qRT-PCR, ELISA, Western blotting were performed in cell cultures and tissue samples to determine localization, regulation, and concentration of SPs. RESULTS: All four SPs, were expressed by healthy human and mouse articular chondrocytes and synoviocytes and were also present in synovial fluid. Treatment with inflammatory mediators like IL-1ß and TNF-α led to short-term upregulation of individual SPs in vitro. In tissues from patients with osteoarthritis and rheumatoid arthritis, protein levels of all four SPs increased significantly compared to the controls used. CONCLUSION: These results show the distribution and amount of SPs in tissues of articular joints. They are produced by chondrocytes and synoviocytes and occur in measurable amounts in synovial fluid. All four SPs seem to be differently regulated under pathologic conditions. Their physiological functions in lowering surface tension and immune defense need further elucidation and make them potential candidates for therapeutic intervention.

Detection of intrinsic cholinergic system in the human lacrimal drainage system: evidence and potential implications.

PURPOSE: To investigate the presence and distribution of epithelial and non-epithelial cholinergic system and cholinergic brush cells in the human lacrimal drainage system. METHODS: The study was performed on fresh frozen human cadaveric samples of the lacrimal drainage system. Immunohistochemistry was performed for assessing the presence and distribution of cholinergic brush cell proteins-villin, acetylcholine synthesizing enzyme, choline acetyltransferase (ChAT); vesicular acetylcholine transporter (VAChT); components of canonical taste transduction signaling cascade, phospholipase C ß2 (PLCß2), and transient receptor potential cation channel, subfamily M, and member 5 (TRPM5). In addition, immunoreactivity to carbonic anhydrase 4 (CA4) was assessed. The immunoreactivity was scored as positive or negative and the distribution patterns in the canaliculi, lacrimal sac, and nasolacrimal duct were investigated. In addition, ultrastructural analysis was performed to ascertain the presence of brush cells by means of scanning electron microscopy (SEM). RESULTS: Villin revealed immunoreactivity in the superficial epithelial cells of lacrimal sac and nasolacrimal ducts. Positive immunoreactivity was also found for ChAT, VAChT, TRPM5, and PLCß2. ChAT expression was limited to the superficial epithelial layers of the lacrimal sac epithelium. TRPM5 and PLCß2 were expressed on the cell membranes, cytoplasm, and basolateral surfaces of the lacrimal sac epithelium and also showed strong expression in the submucosal glandular acinar cells. VAChT showed strong expression in the canaliculus and lacrimal sac and was expressed on the surface of the superficial epithelial cells and the submucosal glandular acinar cells and lining of the blood vessels. There was a uniformly negative immunoreactivity for CA4. SEM revealed single epithelial cells with dense tuft of rigid apical microvilli in the lacrimal sac and nasolacrimal ducts. CONCLUSIONS: This study provides a proof of principle for the presence of an intrinsic epithelial cholinergic mechanism in the lacrimal drainage system.

SFTA3 - a novel surfactant protein of the ocular surface and its role in corneal wound healing and tear film surface tension.

The study aimed to characterize the expression and function of SFTA3 at the ocular surface and in tears. Ocular tissues, conjunctival (HCjE) and human corneal (HCE) epithelial cell lines as well as tearfilm of patients suffering from different forms of dry eye disease (DED) were analyzed by means of RT-PCR, western blot, immunohistochemistry, and ELISA. A possible role of recombinant SFTA3 in corneal wound healing was investigated performing in vitro scratch assays. Tear film regulatory properties were analyzed with the spinning drop method and the regulation of SFTA3 transcripts was studied in HCE and HCjE after incubation with proinflammatory cytokines as well as typical ocular pathogens by real-time RT-PCR and ELISA. The results reveal that human ocular tissue as well as tears of healthy volunteers express SFTA3 whereas tears from patients with DED showed significantly increased SFTA3 levels. In vitro wounding of HCE cell cultures that had been treated with recombinant SFTA3 demonstrated a significantly increased wound closure rate and rSFTA3 reduced the surface tension of tear fluid. The results indicate that SFTA3 at the ocular surface seemed to be involved in wound healing and the reduction of surface tension.

Expression of Surfactant Proteins in the Human Canaliculus: Evidence and Potential Insights Into the Tear Flow Dynamics.

PURPOSE: To investigate the presence and distribution patterns of 6 surfactant proteins (SPs) in the human lacrimal canaliculus. METHODS: The study was performed on fresh frozen cadaveric samples of canaliculi. Immunohistochemical labeling was performed for assessing the presence and distribution of SP: SP-A, SP-B, SP-C, SP-D, SP-G/SFTA2, and SP-H/SFTA3. Immunofluorescence double staining was performed using the respective fluorescein-conjugated antibodies and the results were scored as positive or negative and the distribution pattern within the canalicular system was assessed. Western blot analysis was performed on the protein content which was resolved by reducing 15% sodium dodecyl sulfate-polyacrylamide electrophoresis and bands were studied following staining with primary and secondary antibodies. Human lung tissues were used as controls. RESULTS: Fluorescence double staining with 4,6-diamidino 2-pheynlindole and SPs showed strong immunostaining for SP-A, SP-B, SP-C, SP-D, and SP-H/SFTA3. The positive immunofluorescence was noticed across all the layers of the epithelium but not the subepithelial structures. The expression was noted on the surfaces and superficial cytoplasm of the superficial and deep epithelial cells. There was no expression of SP-G/SFTA2 across the canalicular system. Western blot analysis of the proteins confirmed and concurred with the immunofluorescence findings. CONCLUSIONS: This study provides a proof of principle for the presence of SPs known from lungs in the canalicular system and hypothesizes their possible functions and also their potential role in the tear flow dynamics between the ocular surface and the lacrimal drainage system.

The Cerebral Surfactant System and Its Alteration in Hydrocephalic Conditions.

INTRODUCTION: Pulmonary Surfactant reduces surface tension in the terminal airways thus facilitating breathing and contributes to host's innate immunity. Surfactant Proteins (SP) A, B, C and D were recently identified as inherent proteins of the CNS. Aim of the study was to investigate cerebrospinal fluid (CSF) SP levels in hydrocephalus patients compared to normal subjects. PATIENTS AND METHODS: CSF SP A-D levels were quantified using commercially available ELISA kits in 126 patients (0-84 years, mean 39 years). 60 patients without CNS pathologies served as a control group. Hydrocephalus patients were separated in aqueductal stenosis (AQS, n = 24), acute hydrocephalus without aqueductal stenosis (acute HC w/o AQS, n = 16) and idiopathic normal pressure hydrocephalus (NPH, n = 20). Furthermore, six patients with pseudotumor cerebri were investigated. RESULTS: SP A-D are present under physiological conditions in human CSF. SP-A is elevated in diseases accompanied by ventricular enlargement (AQS, acute HC w/o AQS) in a significant manner (0.67, 1.21 vs 0.38 ng/ml in control, p<0.001). SP-C is also elevated in hydrocephalic conditions (AQS, acute HC w/o AQS; 0.87, 1.71 vs. 0.48 ng/ml in controls, p<0.001) and in Pseudotumor cerebri (1.26 vs. 0.48 ng/ml in controls, p<0.01). SP-B and SP-D did not show significant alterations. CONCLUSION: The present study confirms the presence of SPs in human CSF. There are significant changes of SP-A and SP-C levels in diseases affecting brain water circulation and elevation of intracranial pressure. Cause of the alterations, underlying regulatory mechanisms, as well as diagnostic and therapeutic consequences of cerebral SP's requires further thorough investigations.

Somatostatin supports corneal wound healing in vivo.

PURPOSE: To evaluate the influence of somatostatin (SST) and its analog octreotid (Oct) on corneal wound healing processes. METHODS: The wound healing rate in C57BL/6 mice eyes under SST and Oct treatment was analyzed using an alkali-induced corneal wounding model. Effects of SST and Oct on cell proliferation, migration and quantified protein expression of vascular endothelial growth factor (VEGF) on human corneal epithelial cells (HCE, cell line) were evaluated by means of electric cell-substrate impedance sensing, scratch migration assays and ELISA. ERK1/2 and p38 phosphorylation was investigated by semi-quantitative western blot analysis. RESULTS: Ten nanograms per microliters of SST significantly accelerated the wound closure rate of corneal defects in vivo. SST and Oct had no influence on HCE cell proliferation and migration and did not activate ERK1/2 or p38 signaling in HCE cells. However, there was increased VEGF protein expression in cytosolic proteins and medium supernatants of HCE upon Oct stimulation for 24h. One and 10ng/ml Oct led to a 2.5-fold and 100ng/ml Oct to a 4-fold upregulation of VEGF protein expression. CONCLUSION: The data implicate that SST promotes corneal wound healing in a mouse model. However, using a HCE cell line in vitro, the wound healing mechanism does not seem to be supported by proliferation and migration processes or by activation of ERK1/2 and p38 signaling pathways. Other possible mechanisms could be the activation of other pathways and the induction of growth factors such as VEGF that modulate the observed corneal wound healing process.

Expression and Localization of Lung Surfactant Proteins in Human Testis.

BACKGROUND: Surfactant proteins (SPs) have been described in various tissues and fluids including tissues of the nasolacrimal apparatus, airways and digestive tract. Human testis have a glandular function as a part of the reproductive and the endocrine system, but no data are available on SPs in human testis and prostate under healthy and pathologic conditions. OBJECTIVE: The aim of the study was the detection and characterization of the surfactant proteins A, B, C and D (SP-A, SP-B, SP-C, SP-D) in human testis. Additionally tissue samples affected by testicular cancer were investigated. RESULTS: Surfactant proteins A, B, C and D were detected using RT-PCR in healthy testis. By means of Western blot analysis, these SPs were detected at the protein level in normal testis, seminoma and seminal fluid, but not in spermatozoa. Expression of SPs was weaker in seminoma compared to normal testicular tissue. SPs were localized in combination with vimentin immunohistochemically in cells of Sertoli and Leydig. CONCLUSION: Surfactant proteins seem to be inherent part of the human testis. By means of physicochemical properties the proteins appear to play a role during immunological and rheological process of the testicular tissue. The presence of SP-B and SP-C in cells of Sertoli correlates with their function of fluid secretion and may support transportation of spermatozoa. In seminoma the expression of all SP's was generally weaker compared to normal germ cells. This could lead to a reduction of immunomodulatory and rheology processes in the germ cell tumor.

SFTA3, a novel protein of the lung: three-dimensional structure, characterisation and immune activation.

The lung constantly interacts with numerous pathogens. Thus, complex local immune defence mechanisms are essential to recognise and dispose of these intruders. This work describes the detection, characterisation and three-dimensional structure of a novel protein of the lung (surfactant-associated protein 3 (SFTA3/SP-H)) with putative immunological features. Bioinformatics, biochemical and immunological methods were combined to elucidate the structure and function of SFTA3. The tissue-specific detection and characterisation was performed by using electron microscopy as well as fluorescence imaging. Three-dimensional structure generation and analysis led to the development of specific antibodies and, as a consequence, to the localisation of a novel protein in human lung under consideration of cystic fibrosis, asthma and sepsis. In vitro experiments revealed that lipopolysaccharide induces expression of SFTA3 in the human lung alveolar type II cell line A549. By contrast, the inflammatory cytokines interleukin (IL)-1ß and IL-23 inhibit expression of SFTA3 in A549. Sequence- and structure-based prediction analysis indicated that the novel protein is likely to belong to the family of lung surfactant proteins. The results suggest that SFTA3 is an immunoregulatory protein of the lung with relevant protective functions during inflammation at the mucosal sites.

Articular cartilage chondrocytes express aromatase and use enzymes involved in estrogen metabolism.

INTRODUCTION: Sex hormones, especially estrogens, have been implicated in articular cartilage metabolism and the pathogenesis of postmenopausal osteoarthritis. The conversion by aromatase (CYP19A1) of androstenedione into estrone (E1) and of testosterone into 17ß-estradiol (E2) plays a key role in the endogenous synthesis of estrogens in tissue. METHODS: We analyzed the expression of aromatase (CYP19A1) in immortalized C-28/I2 and T/C-28a2 chondrocytes, as well as in cultured primary human articular chondrocytes and human articular cartilage tissue, by means of RT-PCR, Western blotting and immunohistochemistry. By means of quantitative RT-PCR and enzyme-linked immunosorbent assay, we also determined whether the aromatase inhibitor letrozole influences estrogen metabolism of cultured chondrocytes in immortalized C-28/I2 chondrocytes. RESULTS: Aromatase mRNA was detected in both immortalized chondrocyte cell lines, in cultured primary human chondrocytes, and in human articular cartilage tissue. By means of Western blot analysis, aromatase was detected at the protein level in articular cartilage taken from various patients of both sexes and different ages. Cultured primary human articular chondrocytes, C-28/I2 and T/C-28a2, and human articular cartilage tissue reacted with antibodies for aromatase. Incubation of C-28/I2 chondrocytes with 10⁻¹¹ M to 10⁻7M letrozole as an aromatase inhibitor revealed significantly increased amounts of the mRNAs of the enzyme cytochrome P4501A1 (CYP1A1), which is involved in the catagen estrogen metabolism, and of the estrogen receptors ER-α and ER-ß. Concomitantly, synthesis of estrone (E1) was significantly downregulated after incubation with letrozole. CONCLUSIONS: We demonstrate that human articular cartilage expresses aromatase at the mRNA and protein levels. Blocking of estrone synthesis by the aromatase inhibitor letrozole is counteracted by an increase in ER-α and ER-ß. In addition, CYP1A1, an enzyme involved in catabolic estrogen metabolism, is upregulated. This suggests that articular chondrocytes use ERs functionally. The role of endogenous synthesized estrogens in articular cartilage health remains to be elucidated.

Detection of surfactant proteins A, B, C, and D in human nasal mucosa and their regulation in chronic rhinosinusitis with polyps.

BACKGROUND: The nasal mucosa is characterized by a multirow high prismatic ciliated epithelium representing the first barrier of the immune defense system against microbial and other environmental pathogenic influences. A number of nonspecific defense mechanisms, including the presence of lactoferrin, peroxidases, proteases, interferons, and lysozymes in nasal secretions, act to counter inflammatory processes. The surfactant proteins (SPs) known from the lungs are important components of the innate immune system. They also influence the rheology of fluids and reduce the surface tension of gas-fluid interphases. The objective of this study was to investigate the protein expression of all four SPs. A specific aim was detection and characterization of SP-C, which had previously not been confirmed in human nasal mucosa. METHODS: The expression of mRNA for SP-A, -B, -C and -D was investigated using reverse transcriptase polymerase chain reaction on samples of both healthy nasal mucosa and nasal mucosa altered by inflammatory processes (allergic rhinitis and chronic rhinosinusitis). The distribution of all four proteins was determined with monoclonal antibodies using Western blot analysis as well as immunohistochemical methods. RESULTS: The results show that all four SPs, including SP-C not detected before this, are nasal mucosa components. A shift was also observed in the expression behavior of the SP-A, -B, and -D in nasal mucosa with inflammatory changes. CONCLUSION: Based on these results, SPs appear to have an important function in immunologic and rheological process of the nasal mucosa and support the prospective therapeutic use of liposomal nasal sprays.

Expression analysis of ADAM17 during mouse eye development.

ADAM17 (a disintegrin and metallopeptidase domain 17) is crucial for eye morphogenesis. In this study we analysed the expression pattern of ADAM17 during mouse eye development. ADAM17 expression in adult retina was examined using the reverse transcription-polymerase chain reaction (RT-PCR) and verification of the RT-PCR products by DNA sequencing. Immunohistochemistry was performed to evaluate the ADAM17 expression pattern in mouse eyes at developmental stages of embryonic day (E) 12, E14, E16, E18, postnatal day (P) 0, P1, P4, P7, P14, P 30 and P175 (adult). We detected ADAM17 mRNA in adult retina tissue. ADAM17 protein was expressed in non-pigmented ciliary epithelial cells and in retinal vessels from P7 onwards during eye development. In corneal epithelial cells and endothelium, ADAM17 protein was present from P14 onwards. Although, mice in which the functional ADAM17 gene is significantly reduced develop multiple eye malformations, the expression of ADAM17 is not ubiquitous over the entire eye. Its expression pattern during development suggests that not only TNF-alpha but additional membrane-anchored substrates of ADAM17 play an important role in eye formation.

Roles of human beta-defensins in innate immune defense at the ocular surface: arming and alarming corneal and conjunctival epithelial cells.

Human beta-defensins are cationic peptides produced by epithelial cells that have been proposed to be an important component of immune function at mucosal surfaces. In this study, the expression and inducibility of beta-defensins at the ocular surface were investigated in vitro and in vivo. Expression of human beta-defensins (hBD) was determined by RT-PCR and immunohistochemistry in tissues of the ocular surface and lacrimal apparatus. Cultured corneal and conjunctival epithelial cells were stimulated with proinflammatory cytokines and supernatants of different ocular pathogens. Real-time PCR and ELISA experiments were performed to study the effect on the inducibility of hBD2 and 3. Expression and inducibility of mouse beta-defensins-2, -3 and -4 (mBD2-4) were tested in a mouse ocular surface scratch model with and without treatment of supernatants of a clinical Staphylococcus aureus (SA) isolate by means of immunohistochemistry. Here we show that hBD1, -2, -3 and -4 are constitutively expressed in conjunctival epithelial cells and also partly in cornea. Healthy tissues of the ocular surface, lacrimal apparatus and human tears contain measurable amounts of hBD2 and -3, with highest concentrations in cornea and much lower concentrations in all other tissues, especially tears, suggesting intraepithelial storage of beta-defensins. Exposure of cultured human corneal and conjunctival epithelial cells to proinflammatory cytokines and supernatants of various bacteria revealed that IL-1beta is a very strong inductor of hBD2 and Staphylococcus aureus increases both hBD2 and hBD3 production in corneal and conjunctival epithelial cells. A murine corneal scratch model demonstrated that beta-defensins are only induced if microbial products within the tear film come into contact with a defective epithelium. Our finding suggests that the tear film per se contains so much antimicrobial substances that epithelial induction of beta-defensins occurs only as a result of ocular surface damage. These findings widen our knowledge of the distribution, amount and inducibility of beta-defensins at the ocular surface and lacrimal apparatus and show how beta-defensins are regulated specifically.

Somatostatin actions via somatostatin receptors on the ocular surface are modulated by inflammatory processes.

Recent investigations support the presence of human somatostatin (SS) in the excretory system of the human lacrimal gland. To get deeper insights into a possible role of SS at the ocular surface and in the lacrimal apparatus, we investigated the distribution pattern of SS and its receptors 1-5 (SSTR1-5) by means of RT-PCR, real-time RT-PCR, Western blot and immunodot blot analysis as well as immunohistochemistry in lacrimal gland, tear fluid, conjunctiva, cornea, nasolacrimal duct epithelium, and conjunctival (HCjE) and corneal (HCE) epithelial cell lines. Cell culture experiments with HCjE and HCE were performed to analyze a possible impact of SS and inflammatory mediators on the regulation of SSTR. The results confirmed the presence of SS in lacrimal gland and tear fluid, whereas it was absent at the protein level in all other tissues and cell lines investigated. Expression of SSTR1, -2, and -5 was detectable in lacrimal gland, conjunctiva, cornea, and nasolacrimal ducts. HCjE expressed only hSSTR1 and -2, and HCE revealed only SSTR2. SSTR3 and -4 were not detected in any of the analyzed samples or cell lines. In vitro on cultured immortalized HCjE cells SS leads to a concentration-dependent down-regulation of SSTR1 mRNA but does not affect SSTR2 mRNA expression. Relative expression of SSTR1 and -2 is differentially modulated by proinflammatory cytokines and bacterial components, suggesting that the expression of both receptors is immunomodulated. Our data support an autocrine and paracrine role of SS in the lacrimal system and at the ocular surface and implicate a role of SS in corneal immunology.

Distribution of mucins and antimicrobial substances lysozyme and lactoferrin in the laryngeal subglottic region.

The subglottic region of the larynx is of high clinical relevance with regard to infections and malignancies. Little is known about the distribution of mucins and antimicrobial substances in this area. In this study, we have investigated the mucin distribution in the normal subglottis of the larynx. Moreover, we analysed the expression of lysozyme and lactoferrin in this area. Therefore, the subglottic region of 34 larynges was investigated immunohistochemically with different antibodies to mucins and antimicrobial substances. The epithelium reacted positive with antibodies to mucins MUC1 (34/34), 5AC (26/34), 5B (10/34), 7 (8/34), 8 (10/34) and 16 (19/34); submucosal glands were positive to mucins MUC1 (34/34), 5B (10/34), 7 (8/34), and 16 (19/34); high columnar epithelial cells and serous parts of subepithelial seromucous glands were also positive for lysozyme (34/34) and lactoferrin (34/34). The results show that human subglottic epithelium and subepithelial submucosal glands produce a broad spectrum of mucins that is almost comparable with that in other areas of the respiratory tract. We hypothesize that the mucin diversity of the subglottis has an impact on positive functional consequences during vocal production and antimicrobial defence. This antimicrobial defence is supported by synthesis and secretion of antimicrobial substances such as lysozyme and lactoferrin. Moreover, knowledge of the observed distribution pattern of mucins in the subglottis can be a useful tool for a classification of subglottic laryngeal carcinomas.