Histochemical study on rat tear film and ocular surface epithelial cells

Fibroblasts of healthy and granulation gingiva are phenotypically heterogeneous with regard to binding C1q collagen-like (cC1qR) or C1q globular-heads (gC1qR) regions, respectively. Here, isolated fibroblast subsets, expressing either the cC1qR or the gC1qR phenotype, were stimulated with C1q, and assessed for changes in cytosolic free calcium [Ca2+]i, accumulation of inositol trisphosphate (IP3), and redistribution of Ca2+-dependent protein kinases-C (cPKCs) from cytosol to membranes. Changes in [Ca2+]i were determined using Indo-1 fluorescence in combination with adhering cell analysis and sorting (ACAS) cytometry. Accumulation of IP3 was quantified using a competitive radioreceptor binding assay. Redistribution of cPKCs was evaluated by immunoblotting with antibodies to PKCalpha/betaI-betaII/gamma. Subsets manifested different fluctuations in [Ca2+]i levels 20 seconds after C1q-stimulation in the presence of millimolar concentrations of external calcium. Whereas cC1qR fibroblasts responded with a 38% over baseline [Ca2+]i increase which was sustained for 20 to 30 minutes, gC1qR fibroblasts responded with a higher (264% over baseline) and more rapid (2 to 3 minutes) transient. Likewise, subsets exhibited different kinetics of IP3 accumulation. Whereas cC1qR fibroblasts responded with an IP3 increase of 32 +/- 3 pmol/10(4) cells over baseline after 5 seconds stimulation, gC1qR fibroblasts responded after 15 to 20 seconds with a lower increase (13 +/- 0.8 IP3 pmol/10(4) cells over baseline). Subsets differed in cPKCs redistribution which peaked in gC1qR-membranes 30 seconds after stimulation and remained sustained between 10 and 30 minutes. No cPKC redistribution was detectable in stimulated cC1qR-cells. We conclude that fibroblasts are heterogeneous in phosphoinositide-Ca2+ signaling and cPKC redistribution to C1q, and suggest that these differences may affect activities of normal and granulation gingiva.     

Sodium hyaluronate eyedrops enhance tear film stability

Coeliac disease, also known as gluten-sensitive enteropathy or non-tropical sprue, is a relatively uncommon condition. The dietary presence of gliadin, an alcohol-soluble subfraction of gluten, in immunologically susceptible hosts will lead to small intestinal mucosal inflammation and subsequent mucosal villous atrophy which results in nutrient and vitamin malabsorption. The symptomatic presentations of patients with coeliac disease are related to this malabsorption process which can be reversed in the vast majority of patients with a gluten-free diet.     

Temporal sequence of changes in tear film composition during sleep

Overnight eye closure induces a shift in the nature and composition of the tear film, from a dynamic reflex tear-rich to a stagnant secretory IgA-rich layer. This is accompanied by the induction of a state of sub-clinical inflammation, as evidenced by increases in albumin levels, plasminogen activation, conversion of complement C3 to C3c, and the recruitment of polymorphonuclear (PMN) cells into the tear film. To determine the time course and functional relationship between these potentially interdependent processes, tear samples were collected from ten non-contact lens wearers after 1, 2, 3 and 5 hours of sleep. A subgroup of 6 subjects also self-collected tear samples after 8 hours of sleep. Tear samples were analysed for albumin by quantitative immunofixation assay, secretory IgA (sIgA) by radial immunodiffusion assay, plasmin-like activity using a chromogenic substrate, and complement C3 to C3c conversion by immunoblot assay. Epithelial and PMN cells in the precorneal tear film were recovered from corneal washings from the same subjects after 1, 3, 5 and 8 hours of sleep, and quantified. Results revealed that, unlike epithelial cells which exhibited a slow progressive accumulation as a function of the period of sleep, PMN cell concentration exhibited a lag phase, with recruitment occurring after between 3 and 5 hours of eye closure. This was preceded by plasminogen activation, increases in albumin and sIgA levels, and complement C3 to C3c conversion, all of which occurred within 1 to 3 hours after eye closure. Plasmin-like activity appeared to plateau after 3 hours and then decreased.(ABSTRACT TRUNCATED AT 250 WORDS)     

The modified Schirmer tear test in birds--a method for checking lacrimal gland function

A treatment against osteoporosis can be considered efficacious only when its beneficial effects on bone remodeling, bone mass, and osteoporotic fracture incidence are proven. As for any treatment, proven efficacy must be combined with proven safety. This review analyzes published data on efficacy and safety of alendronate, clodronate and etidronate, the bisphosphonates currently marketed in Italy for osteoporosis treatment. Different studies have shown that alendronate, clodronate and etidronate reduce bone turnover, and increase bone mineral density in postmenopausal osteoporotic patients. Prospective, double blind, multicenter studies reported a reduction in osteoporotic fracture incidence for alendronate and etidronate. Fracture incidence reduction by clodronate, on the other hand, was shown only in an open label study. Finally, a reduction in fracture incidence by etidronate was shown in a large retrospective postmarketing study. Postmarketing surveillance evidenced that osteomalacia, a suspected side effect of etidronate treatment, does not occur at the currently used dose regimens. Postmarketing surveillance of alendronate has recently raised some concern regarding possible severe esophageal damage during alendronate treatment, especially when the drug is not taken according to the manufacturer's instructions.     

人工泪液联合性激素对围绝经期白内障患者超声乳化术后泪膜功能恢复的影响

目的 观察人工泪液联合性激素对围绝经期白内障患者超声乳化术后泪膜功能恢复的影响.方法 64例接受白内障超声乳化联合人工晶状体植入术的围绝经期白内障患者随机分为对照组和实验组2组.对照组术后采用妥布霉素地塞米松点眼,实验组在此基础上联用人工泪液和性激素,观察两组患者术前及术后3、7、30、90d的干眼症状评分、基础泪液分泌试验(SIT)、泪膜破裂时间(BUT)、角膜荧光素染色(CFS)情况.结果 术后3、7、30、90d,实验组干眼症状评分、CFS评分均小于对照组,SIT试验和BUT较时照组长,差异有统计学意义(P＜0.05).结论 围绝经期白内障超声乳化联合人工晶状体植入术患者术后早期使用人工泪液联合性激素治疗有利于泪膜恢复,改善干眼症.     

Effect of hormone replacement therapy on postmenopausal ocular function]

The effects of lung volume and involuntary breathing movements on the human diving response were studied in 17 breath-hold divers. Each subject performed maximal effort apnoeas and simulated dives by apnoea and cold water face immersion, at lung volumes of 60%, 85%, and 100% of prone vital capacity (VC). Time of apnoea, blood pressure, heart rate, skin capillary blood flow, and fractions of end-expiratory CO2 and O2 were measured. The length of the simulated dives was the shortest at 60% of VC, probably because at this level the build up of alveolar CO2 was fastest. Apnoeas with face immersion at 100% of VC gave a marked drop in arterial pressure during the initial 20 s, probably due to high intrathoracic pressure mechanically reducing venous return. The diving response was most pronounced at 60% of VC. We concluded that at the two larger lung volumes both mechanical factors and input from pulmonary stretch receptors influenced the bradycardia and vasoconstriction, resulting in a nonlinear relationship between the breath-hold lung volume and magnitude of the diving response in the near-VC range. Furthermore, the involuntary breathing movements that appeared during the struggle phase of the apnoeas were too small to affect the diving response.     

Correlation of tear clearance rate and fluorophotometric assessment of tear turnover

BACKGROUND: The study sought to determine dynamic changes and theoretical bases of a clinical diagnostic test, the tear clearance rate. METHODS: Thirty four healthy subjects ranging in age from 22 to 84 years underwent examination of tear clearance rate, the Schirmer test with anaesthesia, as well as fluorophotometric measurement of tear turnover, tear volume, and tear flow. By applying 0.5% fluorescein into the conjunctival sac and subsequently measuring colour fades on a Schirmer strip, the tear clearance rate for assessing tear drainage was divided into nine grades. The results of the tear clearance rate were compared with those of the basal tear turnover and tear flow obtained from fluorophotometry. RESULTS: Significant relations were found between the tear clearance rate and the basal tear turnover or tear flow (r = 0.91 and 0.79, respectively, p = 0.0001). Considering the grades of progression from low to high, each grade of tear clearance rate showed a 12.5% increase in basal tear turnover (3.59%/min) and tear flow (0.38 microliter/min). There was no significant correlation between age and the basal tear turnover, tear volume, tear flow, or the tear clearance rate. CONCLUSION: The tear clearance rate is proposed as a simple and useful way to estimate basal tear turnover and tear flow, and measure tear drainage indirectly.     

Long-term course of tear gland function in patients with keratoconjunctivitis sicca and Sj?gren''s syndrome

The reliability and validity of a Confidence of Dental Hygienist in Child Management Scale were examined. Forty-eight dental hygiene students, nine dental staff, and thirty-one dentists were subjects for the reliability and validity scale. The acceptable level of the reliability on the Scale was shown by internal consistency and stability. The confidence scores of the clinician's group were significantly higher than the confidence scores of the students. The reliability and validity of the Confidence Scale were established. Next, we evaluated the effect of behavioral science training, using videotape feedback and role playing on twelve dental hygiene students. Six students received the training, the other six students, the controls, had no training. The confidence scores of the training group were significantly higher than those of the control group, demonstrating that the training was effective for dental hygiene students.     

立式旋风水膜除尘器的除尘性能与设计计算

本文借助于Ｌｅｉｔｈ和Ｌｉｃｈｔ的边界层分离理论，对轴向出风的立式旋风水膜除尘器的除尘性能进行了分析，并得出了除尘效率的理论公式的一些有意义的结果。     

Bioerodible polymers for ocular drug delivery

Development of ophthalmic drug-delivery systems has always been challenging. The commonly used route for drug delivery to the anterior segment of the eye has been the conjunctival cul-de-sac. Because of drawbacks associated with this route, new approaches have been investigated for delivery of drugs to the eye by means of polymeric delivery systems. Development of controlled drug-release devices has been a major step forward in this respect. Bioerodible polymers have been at the forefront of such systems. They are very important because they eliminate the need for removing the implant after complete drug release. Bioerodible polymers have been divided into three classes based on their mechanism of hydrolysis: Type I--hydrolysis of crosslinked hydrogels; Type II--solubilization by ionization or hydrolysis of linear polymers; and Type III--biodegradation by backbone cleavage. Polymers from all three classes are discussed in detail in this review.     

Detection system for ocular refractive error measurement

An automatic and objective system for measuring ocular refractive errors (myopia, hyperopia and astigmatism) was developed. The system consists of projecting a light target (a ring), using a diode laser (lambda = 850 nm), at the fundus of the patient's eye. The light beams scattered from the retina are submitted to an optical system and are analysed with regard to their vergence by a CCD detector (matrix). This system uses the same basic principle for the projection of beams into the tested eye as some commercial refractors, but it is innovative regarding the ring-shaped measuring target for the projection system and the detection system where a matrix detector provides a wider range of measurement and a less complex system for the optical alignment. Also a dedicated electronic circuit was not necessary for treating the electronic signals from the detector (as the usual refractors do); instead a commercial frame grabber was used and software based on the heuristic search technique was developed. All the guiding equations that describe the system as well as the image processing procedure are presented in detail. Measurements in model eyes and in human eyes are in good agreement with retinoscopic measurements and they are also as precise as these kinds of measurements require (0.125D and 5 degrees).     

Cryotherapy for trichiasis in ocular cicatricial pemphigoid

Trichiasis is a common and potentially sight threatening complication of ocular cicatricial pemphigoid and is usually secondary to cicatricial entropion. This study aimed to assess the success and complications of eyelid cryotherapy for trichiasis in a group of patients with long term follow up. The case records of all patients with ocular cicatricial pemphigoid that attended the external disease clinic at Moorfields Eye Hospital from 1980 to 1992 were reviewed. Each eyelid was divided into three horizontal zones. Cryotherapy was delivered with an Amoilette cryoprobe for approximately 30 seconds. Failure of the cryotherapy was defined as a regrowth of the eyelashes within the treated zone that either required epilation for symptom control or caused keratopathy. Ninety two lid zones were treated, involving 25 lids of 12 patients. The cumulative chance of success decreased rapidly to 40% over the first year. Thereafter, the chance of success declined slowly to 34% at 4 years. Complications included lid notching (n = 2), tarsal atrophy (n = 1), altered lid contour (n = 1), and temporarily raised intraocular pressure (n = 1). All patients had quiescent disease at the time of the cryotherapy and no patients showed increased conjunctival disease activity after treatment. Six patients were taking systemic immunosuppression medication. When ocular cicatricial pemphigoid is quiescent, lid cryotherapy has an acceptable complication rate. The major reason for recurrence of the trichiasis was attributed to inadequate follicle freezing.     

A new technique for arthroscopic resection of a bucket handle tear

The authors present a previously undescribed technique for excision of a bucket handle tear. The technique uses a Caspari suture punch to pass a suture through the meniscus and use the suture as a tool to maneuver the meniscus so that its posterior horn attachment can be cut. The technique is noteworthy in that it eliminates the need for establishing an additional portal.     

Functional anatomy of the human efferent tear ducts: a new theory of tear outflow mechanism

BACKGROUND: The mechanism of lacrimal drainage under physiological conditions is controversial. The aim of this study was to analyze the three-dimensional architecture of human efferent tear ducts from functional and clinical points of view. A new theory of tear outflow is discussed. METHODS: Thirty-two prepared lacrimal systems of adults were examined by histological, immunohistochemical and scanning electron microscopic techniques. RESULTS: The wall of the lacrimal sac is made up of collagen bundles, elastic and reticular fibers arranged in a helical pattern. Wide luminal vascular plexus are embedded in this helical system and connected to the cavernous tissue of the inferior turbinate in the region of Hasner's valve. Immunohistochemical analysis showed evidence of type I and type III collagen as well as chondroitin 4- and 6-sulfate. CONCLUSION: With blinking, the lacrimal part of the orbicularis muscle contracts. The fornix of the sac moves in a cranial-lateral direction. Thus the lacrimal sac distends and may be "wrung out" due to its medial attachment and helically arranged fibrillar structures. The vascular plexus may play an important role in the absorption and drainage of lacrimal fluid.     

Immunohistochemical localization of human tear lysozyme

Possible local sources of human tear lysozyme were investigated using an indirect immunofluorescence technique. Lysozyme was identified in 20% to 50% of acinar and ductular epithelial cells of both main and accessory lacrimal glands. The staining was granular in character and confined to the apices of the cells. Cells that stained positive tended to be grouped. Interstitial tissues of main and accessory lacrimal tissues did not stain. Conjunctiva and all other ocular tissues examined were unstained by antilysozyme antisera. Our findings are compatible with lysozyme either being produced in lacrimal tissue or being concentrated from plasma. The absence of any other lysozyme-specific fluorescence in the interstitial elements of the lacrimal tissues supports the notion of local synthesis by acinar lacrimal tissue.