Corneal Sensory Experience via Transient Receptor Potential Vanilloid 1 Accelerates the Maturation of Neonatal Tearing.

Tearing maturates rapidly after birth, and external environmental challenges play a key role in promoting lacrimal functional maturation. However, little is known about the facilitative factors underlying this developmental process or the potential of application of these factors to treat hypofunction of the lacrimal gland. In this study, eye opening and the subsequent ocular surface sensory experience, which is thought to be involved in postnatal maturation of lacrimal function, were investigated. Our results demonstrated that eye opening after birth is essential for the maturation of neonatal tearing. The maturation process of lacrimal function is dependent on the ocular surface sensory experience via transient receptor potential cation channel subfamily member 1 after birth. This study provides, for the first time, important evidence of the sensory experience of the ocular surface in relation to the maturation of functional tear secretion during the postnatal period.

Intravital Two-photon Imaging of Ca2+ signaling in Secretory Organs of Yellow Cameleon Transgenic Mice.

Intracellular calcium ([Ca2+]i) signaling regulates physiological functions in most cells. In secretory organs, such as the pancreas, salivary gland, and lacrimal gland (LG), [Ca2+]i elevation in acinar cells triggers fluid secretion, which plays vital roles in the maintenance of functional health across the life-course. It is important to understand the secretory mechanism of secretory organs, but lack of analytic systems available for living animals limits the scope of research to gain deeper insights into the precise mechanism of secretion. We established an intravital imaging system for specific cell types of secretory organs to monitor the [Ca2+]i changes using mouse line expressing Yellow Cameleon 3.60, a genetically encoded Ca2+ indicator. Elevation of [Ca2+]i in specific cell types of secretory organs could be monitored after cholinergic stimulation ex vivo and intravitally. We found that a marked attenuation of LG [Ca2+]i response to cholinergic stimulation was induced under pathological conditions by postganglionic denervation. Intravital Ca2+ imaging in secretory organs will broaden our understanding of the cellular mechanisms in animal models of secretory diseases.

Restoration of Tear Secretion in a Murine Dry Eye Model by Oral Administration of Palmitoleic Acid.

Sea buckthorn (Hippophae rhamnoides)-derived products have traditionally been used as food and medicinal ingredients in Eastern countries. The purpose of this study was to investigate the effect of oral intake of sea buckthorn oil products on tear secretion using a murine dry eye model. Orally administered sea buckthorn pulp oil (not seed oil) restored aqueous tear secretion to its normal value under a dry eye condition. Palmitoleate (C16:1), a fatty acid present in sea buckthorn pulp oil, preserved tear secretion and suppressed inflammatory cytokines in the lacrimal gland to the same extent as that by pulp oil. These results suggest that an oral intake of sea buckthorn pulp oil has a potency to preserve tear secretion capacity in the dry eye state and palmitoleate, its main constituent fatty acid, is an active component of the oil. This effect may enable a potent diet-based treatment for the prevention of dry eye.

A new local variant (ST764) of the globally disseminated ST5 lineage of hospital-associated methicillin-resistant Staphylococcus aureus (MRSA) carrying the virulence determinants of community-associated MRSA.

The ST5 lineage of methicillin-resistant Staphylococcus aureus (MRSA) is one of the most globally disseminated hospital-associated MRSA (HA-MRSA) lineages. We isolated a new local variant (designated ST764) over at least 5 years that causes invasive infections, including necrotizing fasciitis, and is carried by medical students, as well as household members. Analysis of the genome sequence of one isolate compared to that of the reference ST5 strain revealed that ST764 had acquired virulence traits similar to those of community-associated MRSA (CA-MRSA) through the acquisition of two new mobile genetic elements, ACMEII and SaPInn54, which carried ACME arcA and the staphylococcal enterotoxin B gene (seb), respectively, and through enhanced expression of cytolytic peptide genes, although ST764 was negative for Panton-Valentine leukocidin. Other differences between ST764 and ST5 included the acquisition of an ACMEII-related cassette (cJR1), prophage φ2NN54, and streptococcal Tn5251 and decreased numbers of copies of Tn554. As for superantigen genes, although the two possessed seg, sei, sem, sen, and seo, ST764 lacked tst, sec, sel, and sep. The data suggest that ST764 MRSA is a novel hybrid variant of ST5 HA-MRSA with the characteristics of CA-MRSA and that the evolution of ST764 includes multiple steps, e.g., acquisition of novel or nonstaphylococcal mobile elements.

Lacrimal hypofunction as a new mechanism of dry eye in visual display terminal users.

BACKGROUND: Dry eye has shown a marked increase due to visual display terminal (VDT) use. It remains unclear whether reduced blinking while focusing can have a direct deleterious impact on the lacrimal gland function. To address this issue that potentially affects the life quality, we conducted a large-scale epidemiological study of VDT users and an animal study. METHODOLOGY/PRINCIPAL FINDINGS: Cross sectional survey carried out in Japan. A total of 1025 office workers who use VDT were enrolled. The association between VDT work duration and changes in tear film status, precorneal tear stability, lipid layer status and tear secretion were analyzed. For the animal model study, the rat VDT user model, placing rats onto a balance swing in combination with exposure to an evaporative environment was used to analyze lacrimal gland function. There was no positive relationship between VDT working duration and change in tear film stability and lipid layer status. The odds ratio for decrease in Schirmer score, index of tear secretion, were significantly increased with VDT working year (P = 0.012) and time (P = 0.005). The rat VDT user model, showed chronic reduction of tear secretion and was accompanied by an impairment of the lacrimal gland function and morphology. This dysfunction was recovered when rats were moved to resting conditions without the swing. CONCLUSIONS/SIGNIFICANCE: These data suggest that lacrimal gland hypofunction is associated with VDT use and may be a critical mechanism for VDT-associated dry eye. We believe this to be the first mechanistic link to the pathogenesis of dry eye in office workers.

Novel characteristics of community-acquired methicillin-resistant Staphylococcus aureus strains belonging to multilocus sequence type 59 in Taiwan.

Community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) strains, which often produce Panton-Valentine leucocidin (PVL), are increasingly noted worldwide. In this study, we examined 42 MRSA strains (25 PVL-positive [PVL+] strains and 17 PVL-negative [PVL(-)] strains) isolated in Taiwan for their molecular characteristics. The PVL+ MRSA strains included CA-MRSA strains with multilocus sequence type (ST) 59 (major PVL+ MRSA in Taiwan), its variants, and worldwide CA-MRSA ST30 strains. The PVL(-) MRSA strains included the pandemic Hungarian MRSA ST239 strain, the Hungarian MRSA ST239 variant, MRSA ST59 (largely hospital-acquired MRSA strains) and its variants, the pandemic New York/Japan MRSA ST5 strain (Japanese type), and the MRSA ST8 strain. The major PVL+ CA-MRSA ST59 strain possessed a tetracycline resistance-conferring (tetK positive) penicillinase plasmid and a drug resistance gene cluster (a possible composite transposon) for multidrug resistance. Moreover, it carried a novel staphylococcal cassette chromosome mec (SCCmec) with two distinct ccrC genes (ccrC2-C8). This SCCmec (previously named SCCmec type V(T)) was tentatively designated SCCmec type VII. Sequencing of the PVL genes revealed the polymorphisms, and the PVL+ CA-MRSA ST59 strain possessed the ST59-specific PVL gene sequence. The data suggest that a significant amount of clonal spread is occurring in Taiwan and that the major PVL+ CA-MRSA ST59 Taiwan strain exhibits unique genetic characteristics, such as a novel SCCmec type and an ST59-specific PVL gene sequence.

Involvement of oxidative stress on corneal epithelial alterations in a blink-suppressed dry eye.

PURPOSE: To investigate whether oxidative stress is involved in the etiology of the corneal disorder in blink-suppressed dry eye in a clinically relevant in vivo rat model. METHODS: A series of treatments were performed under continuous exposure to low-humidity airflow. Rats were placed on a jogging board (JB) made of a plastic pipe for 7.5 h/d, and for 16.5 hours, they were placed in individual cages without a JB. This protocol was repeated for up to 30 days. Corneal surface alteration was evaluated by the score of punctate fluorescein staining. To assess oxidative stress status, the levels of damaged DNA, and the protein modification by reactive aldehydes in corneal epithelia were detected by immunohistochemistry, using 8-hydroxy-2-deoxyguanosine, 4-hydroxynonenal- and malondialdehyde-specific antibodies. RESULTS: Significant increases in the fluorescein staining score were observed from days 1 to 30 compared with the initial value. The average score for the dry eye group was significantly increased compared with that for the nontreatment group at all time points throughout the experiment. Immunoreactivity of all oxidative stress markers increased in the dry eye treatment. Quantitative analysis of the positive-stained cells showed a significant increase in the number of positive cells after 10 and 30 days in the dry eye treatment group compared with the nontreatment group. CONCLUSIONS: These results suggest a relationship between the accumulation of oxidative stress and the etiology of corneal epithelial alterations in blink-suppressed dry eye.

D-beta-hydroxybutyrate protects against corneal epithelial disorders in a rat dry eye model with jogging board.

PURPOSE: The purpose of this study was to establish a rat dry eye model of corneal epithelial disorders by inducing improper tear dynamics and change in blink frequency. The protective effect of d-beta-hydroxybutyrate (HBA) on the corneal epithelia was also investigated. METHODS: A series of treatments were performed under continuous exposure to low-humidity airflow. Rats were placed on a jogging board (JB) made of a plastic pipe for 7.5 h/d, and, for 16.5 hours, they were placed in individual cages without JB treatment. The resultant changes in tear dynamics and corneal epithelial structure were then analyzed. Five days after the rats were exposed to the treatment, eyes that showed corneal fluorescein staining were examined, to investigate the effect of HBA, by administration of eye drops containing 80 mM HBA four times daily during JB treatment for 5 days. RESULTS: Significant reductions in blink frequency, Schirmer score, and tear clearance were recorded during JB treatment in eyes that showed persistent punctate staining of almost one half of the corneal surface. The application of HBA-containing eye drops significantly reduced the punctate staining compared with the initial or phosphate-buffered saline-treated eyes. CONCLUSIONS: This rat dry eye model, established by repeated JB treatment in desiccating conditions, induced abnormal tear dynamics and superficial punctate keratopathy similar to that in humans. These findings suggest the potential clinical application of HBA in corneal surface epithelial disorders in patients with moderate to mild dry eye.

Protective effect of D-beta-hydroxybutyrate on corneal epithelia in dry eye conditions through suppression of apoptosis.

PURPOSE: To investigate the effect of D-beta-hydroxybutyrate (HBA) on ocular surface epithelial disorders induced by tear fluid deficiency, the potency of HBA and serum, the efficacy of which has been well documented in clinical application, were compared. METHODS: Rat corneal epithelial erosion was induced by exposure of rat eyes to continuous low-humidity airflow, which accelerated the tear evaporation. During desiccation, one eye of each rat was treated with HBA (20, 40, or 80 mM) or rat serum (5%, 20%, or 100%), and in the other eye a drop of phosphate-buffered saline (PBS) was instilled as the control. Histopathologic examination and quantification of the epithelial defect area were performed. The apoptosis in the epithelia was determined by chromatin condensation using the Hoechst 33342 fluorescein probe. RESULTS: In PBS-treated eyes, thinning in the cell layer was seen on the periphery of the initial wound after 6 hours, and it progressed to defects after 12 hours. In the 80-mM HBA and 20% serum applications, the pathologic change in the epithelia was moderate, and the structure was maintained in an almost normal state in the 100% serum application. Significant decreases in the defect areas were observed in the 5%, 20%, and 100% serum and 40- and 80-mM HBA treatment groups compared with the PBS-treated eyes (n=12). A significant suppression of chromatin condensation was observed with HBA and serum treatment. CONCLUSIONS: These results suggest the potential clinical application of HBA for ocular surface epithelial disorders to maintain epithelial cell viability in patients with dry eye.

[Clinico-statistical analysis of renal cell carcinomas in patients on hemodialysis].

Eleven patients on hemodialysis that were surgically treated for renal cell carcinomas during the recent 10 years at our institutes were clinically analyzed. Patients' ages at presentation ranged from 35 to 70 years with an average of 54.8 years. Nine of the 11 patients were males and 2 were females. Periods between the introduction of hemodialysis and the presentation ranged from 1 to 21 years with an average of 11.7 years. The most frequent cause of hemodialysis was chronic glomerulonephritis. Five patients presented with macroscopic hematuria, which was the most frequent clinical manifestation. Transperitoneal nephrectomy through a lumbar oblique incision was performed in 9 of 12 surgical procedures. Transperitoneal resection and retroperitoneal endoscopic resection were performed on 2 patients and 1 patient, respectively. Blood transfusion was performed on 2 patients with retroperitoneal hemorrhage before or after operation and 2 patients with pre-existing renal anemia. Pathologically, 9 patients had pT1a disease. Patients were followed up for up to 7 years and 11 months. One patient died of the disease and 2 patients died of unknown causes. In conclusion, surgical removal of renal cell carcinomas was well tolerated, safe and effective treatment in patients under hemodialysis.