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1.
Ecol Evol ; 11(10): 5204-5219, 2021 May.
Article in English | MEDLINE | ID: mdl-34026001

ABSTRACT

Body condition in mammals fluctuates depending on energy intake and expenditure. For brown bears (Ursus arctos), high-protein foods facilitate efficient mass gain, while lipids and carbohydrates play important roles in adjusting dietary protein content to optimal levels to maximize energy intake. On the Shiretoko Peninsula, Hokkaido, Japan, brown bears have seasonal access to high-lipid pine nuts and high-protein salmon. To assess seasonal and annual fluctuation in the body condition of adult female brown bears in relation to diet and reproductive status, we conducted a longitudinal study in a special wildlife protection area on the Shiretoko Peninsula during 2012-2018. First, analyses of 2,079 bear scats revealed that pine nuts accounted for 39.8% of energy intake in August and salmon accounted for 46.1% in September and that their consumption by bears varied annually. Second, we calculated the ratio of torso height to torso length as an index of body condition from 1,226 photographs of 12 adult females. Results indicated that body condition continued to decline until late August and started to increase in September when salmon consumption increased. In addition, body condition began to recover earlier in years when consumption of both pine nuts and salmon was high. Furthermore, females with offspring had poorer body condition than solitary females, in particular in late August in years with low salmon consumption. Our findings suggest that coastal and subalpine foods, which are unique to the Shiretoko Peninsula, determine the summer body condition of female brown bears, as well as their survival and reproductive success.

2.
PeerJ ; 8: e9982, 2020.
Article in English | MEDLINE | ID: mdl-32999770

ABSTRACT

Body condition is an important determinant of health, and its evaluation has practical applications for the conservation and management of mammals. We developed a noninvasive method that uses photographs to assess the body condition of free-ranging brown bears (Ursus arctos) in the Shiretoko Peninsula, Hokkaido, Japan. First, we weighed and measured 476 bears captured during 1998-2017 and calculated their body condition index (BCI) based on residuals from the regression of body mass against body length. BCI showed seasonal changes and was lower in spring and summer than in autumn. The torso height:body length ratio was strongly correlated with BCI, which suggests that it can be used as an indicator of body condition. Second, we examined the precision of photograph-based measurements using an identifiable bear in the Rusha area, a special wildlife protection area on the peninsula. A total of 220 lateral photographs of this bear were taken September 24-26, 2017, and classified according to bear posture. The torso height:body/torso length ratio was calculated with four measurement methods and compared among bear postures in the photographs. The results showed torso height:horizontal torso length (TH:HTL) to be the indicator that could be applied to photographs of the most diverse postures, and its coefficient of variation for measurements was <5%. In addition, when analyzing photographs of this bear taken from June to October during 2016-2018, TH:HTL was significantly higher in autumn than in spring/summer, which indicates that this ratio reflects seasonal changes in body condition in wild bears. Third, we calculated BCI from actual measurements of seven females captured in the Rusha area and TH:HTL from photographs of the same individuals. We found a significant positive relationship between TH:HTL and BCI, which suggests that the body condition of brown bears can be estimated with high accuracy based on photographs. Our simple and accurate method is useful for monitoring bear body condition repeatedly over the years and contributes to further investigation of the relationships among body condition, food habits, and reproductive success.

3.
PLoS One ; 12(4): e0176251, 2017.
Article in English | MEDLINE | ID: mdl-28441423

ABSTRACT

Knowing the reproductive characteristics of a species is essential for the appropriate conservation and management of wildlife. In this study, we investigated the demographic parameters, including age of primiparity, litter size, inter-birth interval, reproductive rate, and cub survival rate, of Hokkaido brown bears (Ursus arctos yesoensis) in the Rusha area on the Shiretoko Peninsula, Hokkaido, Japan, based on a long-term, individual-based monitoring survey. A total of 15 philopatric females were observed nearly every year from 2006 to 2016, and these observations were used to estimate reproductive parameters. The mean age of primiparity was 5.3 ± 0.2 (SE) years (n = 7, 95% CI = 5.0-5.6). We observed 81 cubs in 46 litters from 15 bears. Litter size ranged from one to three cubs, and averaged 1.76 ± 0.08 (SE) cubs/litter (95% CI = 1.61-1.91). Inter-birth intervals ranged from 1 to 4 years, and the mean value was estimated as 2.43 (95% CI = 2.16-2.76) and 2.53 (95% CI = 2.26-2.85) years in all litters and in litters that survived at least their first year, respectively. The reproductive rate was estimated from 0.70 to 0.76 young born/year/reproductive adult female, depending on the method of calculation. The cub survival rate between 0.5 and 1.5 years ranged from 60 to 73%. Most cub disappearances occurred in July and August, suggesting that cub mortality is mainly due to poor nutrition in the summer. All reproductive parameters observed in the Rusha area on the Shiretoko Peninsula fell within the range reported in Europe and North America, and were among the lowest or shortest age of primiparity, litter size, and inter-birth intervals, and ranked at a high level for reproductive rate.


Subject(s)
Litter Size , Reproduction/physiology , Ursidae/physiology , Animals , Animals, Newborn , Animals, Wild , Female , Japan , Parturition/physiology , Pregnancy , Survival Rate
4.
Nippon Ganka Gakkai Zasshi ; 113(9): 906-12, 2009 Sep.
Article in Japanese | MEDLINE | ID: mdl-19882928

ABSTRACT

PURPOSE: To compare the affect upon bacterial flora found in the conjunctival sacs and the microbial sensitivity of a gatifloxacin (GFLX) ophthalmic solution prospectively with two instillation method groups. METHODS: In one group (group A) GFLX solution was instilled postoperatively eight times/day for 2 days and subsequently four times/day for 12 days. In the other group (group B) the solution was instilled four times/day for 28 days. We investigated bacterial flora in the conjunctival sacs of patients who were to undergo cataract surgery, and tested for microbial sensitivity. RESULTS: There was no significant difference in the detection rate of bacterial flora in the conjunctival sacs. One bacterial isolate resistant to LVFX was identified in group A, and one resistant to GFLX and LVFX in group B. CONCLUSION: There is a possibility that the application of topical antibiotics may have little influence on positive culture. However, the occurrence of a resistance to GFLX indicates that the aimless use of antibiotics should be avoided during ophthalmic perioperative periods.


Subject(s)
Anti-Infective Agents/administration & dosage , Anti-Infective Agents/pharmacology , Antibiotic Prophylaxis , Bacteria/drug effects , Conjunctiva/microbiology , Fluoroquinolones/administration & dosage , Fluoroquinolones/pharmacology , Anti-Bacterial Agents/pharmacology , Gatifloxacin , Humans , Microbial Sensitivity Tests , Perioperative Care
5.
Nippon Ganka Gakkai Zasshi ; 113(6): 672-4, 2009 Jun.
Article in Japanese | MEDLINE | ID: mdl-19606809

ABSTRACT

PURPOSE: To study the effect of intravitreal bevacizumab on macular edema secondary to branch retinal vein occlusion (BRVO). SUBJECTS AND METHODS: 6 eyes of 5 patients averaging 70 years, who had received either retinal photocoagulation or trans-tenon retrobulbar triamcinolone injections or both, but in whom the macular edema remained. There was an average of 337 days from BRVO onset to injection of bevacizumab. Corrected vision and foveal thickness were measured. RESULTS: Visual acuity and foveal thickness improved significantly one month after injection. CONCLUSION: Intravitreal injection of bevacizumab is effective for a short time.


Subject(s)
Angiogenesis Inhibitors/administration & dosage , Antibodies, Monoclonal/administration & dosage , Macular Edema/drug therapy , Retinal Vein Occlusion/complications , Aged , Aged, 80 and over , Antibodies, Monoclonal, Humanized , Bevacizumab , Female , Humans , Injections , Macular Edema/complications , Male , Middle Aged , Vitreous Body
6.
J Ocul Pharmacol Ther ; 24(5): 521-6, 2008 Oct.
Article in English | MEDLINE | ID: mdl-18808364

ABSTRACT

PURPOSE: The aim of this study was to determine the short-term effects of topical tafluprost, a novel prostaglandin F(2) derivative, on feline retinal circulation. METHODS: Seventeen (17) adult cats were anesthetized with enflurane and mechanically ventilated. One (1) drop of tafluprost (0.0015%; n = 8), latanoprost (0.005%; n = 5), or control vehicle (n = 4) was instilled in 1 eye and the fellow eye was untreated. We measured the intraocular pressure (IOP), vessel diameter, and blood velocity simultaneously for 120 min in the large retinal arterioles and calculated the retinal blood flow (RBF) with a laser Doppler velocimetry system. RESULTS: Tafluprost 0.0015% significantly increased RBF (maximum change, 42.8 +/- 4.2% [mean +/- standard error of the mean; P < 0.01) and blood velocity (maximum change, 24.1 +/- 3.3%; P < 0.01) for 120 min after instillation; there was no significant change in vessel diameter. Latanoprost 0.005% significantly increased RBF (maximum change, 31.7 +/- 3.4%; P < 0.05); there was no significant change in vessel diameter and blood velocity. There were no significant differences in the IOP reduction among the three groups. CONCLUSIONS: We observed, for the first time, that topical tafluprost significantly increased RBF in cats, suggesting that dual-action tafluprost may be a beneficial antiglaucomatous agent for reducing IOP and increasing RBF.


Subject(s)
Antihypertensive Agents/administration & dosage , Prostaglandins F/administration & dosage , Retinal Vessels/drug effects , Administration, Topical , Animals , Antihypertensive Agents/pharmacology , Blood Flow Velocity/drug effects , Cats , Female , Intraocular Pressure/drug effects , Laser-Doppler Flowmetry , Latanoprost , Male , Ophthalmic Solutions , Prostaglandins F/pharmacology , Prostaglandins F, Synthetic/administration & dosage , Prostaglandins F, Synthetic/pharmacology , Regional Blood Flow/drug effects , Retinal Vessels/physiology , Time Factors
8.
Am J Ophthalmol ; 143(3): 531-3, 2007 Mar.
Article in English | MEDLINE | ID: mdl-17317409

ABSTRACT

PURPOSE: To evaluate serum prorenin levels in preterm infants with or without retinopathy of prematurity (ROP). DESIGN: Noncomparative retrospective case control study. METHODS: Serum prorenin levels in children with a gestational age younger than 36 weeks were measured with antibody-activating direct enzyme kinetic assay. RESULTS: The mean prorenin concentrations were higher in preterm infants with ROP than in infants without ROP at every time point: from 26 to 30 weeks, 2326 +/- 334 microg/ml (mean +/- SE [standard error]) (n = 3) and 1164 +/- 234 microg/ml (n = 3), respectively (P < .05); from 31 to 35 weeks, 1760 +/- 496 microg/ml (n = 10) and 957.1 +/- 139 microg/ml (n = 25) (P < .05); from 36 to 40 weeks, 958.2 +/- 194.2 microg/ml (n = 23) and 470.1 +/- 32.6 microg/ml (n = 67) (P < .01); and from 41 to 45 weeks, 575.8 +/- 148.4 (n = 9) and 385.6 +/- 47.9 (n = 13), which is not significantly different. CONCLUSIONS: Prorenin levels in preterm infants can predict which infants will develop ROP.


Subject(s)
Renin/blood , Retinopathy of Prematurity/blood , Case-Control Studies , Gestational Age , Humans , Infant, Newborn , Infant, Premature/blood , Retinopathy of Prematurity/classification , Retrospective Studies
9.
Jpn J Ophthalmol ; 50(5): 465-468, 2006.
Article in English | MEDLINE | ID: mdl-17013701

ABSTRACT

PURPOSE: Nitric oxide (NO) plays an important role in homeostatic vasodilation and the regulation of blood flow. On the other hand, excess release of NO causes various vascular complications. There are only a few reports on the relationship between plasma NO levels and microvascular complications, especially diabetic retinopathy (DR) in patients with type 2 diabetes. The purpose of this study was to determine the relationship between plasma NO levels and DR. METHODS: In a prospective study, blood samples were obtained from 36 patients with diabetes and no diabetic retinopathy (NDR), 43 patients with nonproliferative diabetic retinopathy (NPDR), 18 patients with proliferative diabetic retinopathy (PDR), and 40 subjects without diabetes mellitus, who served as controls. The levels of plasma NOx (nitrite and nitrate), the stable metabolites of NO, were measured by high-performance liquid chromatography with the Griess method. RESULTS: The plasma NOx levels were 92.8 +/- 16.0, 70.2 +/- 6.8, 90.3 +/- 9.1, and 53.8 +/- 6.1 micromol/l in patients with NDR, NPDR, or PDR, and in the controls, respectively. The plasma NOx levels in the three diabetic groups were significantly higher than those in the control group (P < 0.05 in each case). CONCLUSION: The increased plasma NO levels in patients with type 2 diabetes indicate that NO may be associated with the pathogenesis of DR.


Subject(s)
Diabetic Retinopathy/blood , Nitric Oxide/blood , Adolescent , Adult , Aged , Aged, 80 and over , Biomarkers/blood , Female , Follow-Up Studies , Humans , Male , Middle Aged , Prognosis , Prospective Studies , Severity of Illness Index
10.
Jpn J Ophthalmol ; 50(4): 377-379, 2006.
Article in English | MEDLINE | ID: mdl-16897225

ABSTRACT

PURPOSE: To evaluate quantitatively the effects of bucillamine on the entrapment of leukocytes in the retinal microcirculation of diabetic rats. METHODS: 13 male Brown Norway rats were injected with streptozotocin (STZ). After the animals developed diabetes, they were divided into two groups. Group 1 (n=7) received fresh drinking water without bucillamine, and group 2 (n=6) received fresh drinking water supplemented with bucillamine (200 mg/kg per day). Rats that were not injected with STZ and received water without bucillamine served as controls (n=6). Four weeks after the injection of STZ, the leukocytes in the retina were observed by acridine orange digital fluorography. The number of leukocytes trapped in the retinal vessels was compared among the three groups. RESULTS: In the untreated diabetic rats, the number of trapped leukocytes was significantly higher than in control rats or bucillamine-treated diabetic rats (P<0.05). CONCLUSIONS: We demonstrated an inhibitory effect of bucillamine on leukocyte entrapment in the retinal vessels of diabetic rats. Bucillamine may have therapeutic efficacy in preventing the development of diabetic retinopathy.


Subject(s)
Antioxidants/therapeutic use , Cysteine/analogs & derivatives , Diabetic Retinopathy/drug therapy , Leukocytes/pathology , Microcirculation/drug effects , Retina/pathology , Animals , Cysteine/therapeutic use , Diabetes Mellitus, Experimental/complications , Diabetic Retinopathy/etiology , Diabetic Retinopathy/physiopathology , Male , Rats , Rats, Inbred BN , Retina/drug effects , Retina/physiopathology , Streptozocin/toxicity
11.
Jpn J Ophthalmol ; 49(2): 162-5, 2005.
Article in English | MEDLINE | ID: mdl-15838736

ABSTRACT

PURPOSE: To determine the changes in the pulse amplitude (PA) and the pulsatile ocular blood flow (POBF) after scleral buckling (SB). METHODS: Retrospectively, we studied 24 patients (average age, 52 years) who had undergone SB to repair a retinal detachment in one eye. The patients were divided into two groups: those in whom SB had been performed less than 6 months earlier (n = 10), and those in whom the procedure had been performed more than 6 months previously (n = 14). In each group, the PA and the POBF were determined with a computerized tonometry system, and the values in the SB eyes were compared with those in the control fellow eyes. RESULTS: Within 6 months postoperatively, the mean PA in the SB eyes (0.66 +/- 0.30 mmHg) was significantly lower than that in the control eyes (1.43 +/- 0.34 mmHg; P < 0.05). The mean POBF in the SB eyes (349.5 +/- 154.1 microl/min) was also significantly lower than that in the control eyes (631.0 +/- 226.6 microl/min; P < 0.05). After more than 6 months postoperatively, there were no significant differences in the PA or the POBF between the SB eyes (1.08 +/- 0.49 mmHg and 612.4 +/- 341.2 microl/min, respectively) and the control eyes (1.50 +/- 0.51 mmHg and 589.5 +/- 278.4 microl/min, respectively). CONCLUSIONS: These results indicate that the choroidal blood flow decreases after SB but returns to normal levels after 6 months.


Subject(s)
Choroid/blood supply , Pulsatile Flow/physiology , Retinal Detachment/physiopathology , Scleral Buckling , Blood Flow Velocity/physiology , Humans , Intraocular Pressure/physiology , Middle Aged , Regional Blood Flow/physiology , Retinal Detachment/surgery , Retrospective Studies , Tonometry, Ocular
12.
Exp Eye Res ; 80(4): 493-9, 2005 Apr.
Article in English | MEDLINE | ID: mdl-15781276

ABSTRACT

To investigate the effect of an adenosine agonist, 2-5'-N-ethylcarboxamidoadenosine (NECA), on the outward active transport of fluorescein across the retinal pigment epithelium (RPE) in rabbits. High (5x10(-4)-2x10(-3) M) and low (1x10(-5)-1x10(-4) M) concentrations of NECA or phosphate buffered saline (PBS) were intravitreously injected into Dutch-belted rabbits. Sodium fluorescein was injected intravenously 180 min after NECA. Differential vitreous fluorophotometry was performed 3 hr after the sodium fluorescein injection and the vitreal fluorescein/fluorescein monoglucuronide (F/FG) ratio then was calculated. The F/FG ratios are inversely proportional to the outward active transport of fluorescein across the RPE. Retinal detachments were induced by injection of PBS into the subretinal space after the intravitreous injection of low- or high-dose NECA or PBS, and the size of the blebs was monitored. In eyes that received a low-dose injection of NECA, the F/FG ratio was higher compared with controls (P<0.05); in eyes that received a high-dose intravitreal injection, the F/FG ratio was significantly lower compared with controls (P<0.05). The effect of low-dose NECA on the F/FG ratio was suppressed by the A2 receptor antagonist, ZM241385, and the effect of high-dose NECA was suppressed by the A1 receptor antagonist, 8-cyclopentyl-1, 3-dipropylxanthine. The A3 receptor antagonist MRS1191 did not influence the effect of low- or high-dose NECA. Intravitreal injection of high-dose NECA enhanced the reabsorption of subretinal fluid compared with PBS; however, low-dose NECA inhibited reabsorption of subretinal fluid (P<0.02 and 0.05, respectively). Intravitreous injection of high-dose NECA accelerates the active outward transport across the RPE via A1 receptors and low-dose NECA decelerates it via A2 receptors.


Subject(s)
Adenosine-5'-(N-ethylcarboxamide)/pharmacology , Fluorescein/pharmacokinetics , Pigment Epithelium of Eye/metabolism , Adenosine/metabolism , Adenosine A1 Receptor Antagonists , Adenosine A2 Receptor Antagonists , Adenosine A3 Receptor Antagonists , Animals , Biological Transport, Active , Dihydropyridines/administration & dosage , Fluorescein/administration & dosage , Fluorescein/analysis , Fluoresceins/analysis , Fluorophotometry/methods , Injections, Intravenous , Male , Purinergic P1 Receptor Antagonists , Rabbits , Retinal Detachment/metabolism , Triazines/administration & dosage , Triazoles/administration & dosage , Xanthines/pharmacology
13.
Exp Eye Res ; 78(1): 103-8, 2004 Jan.
Article in English | MEDLINE | ID: mdl-14667832

ABSTRACT

BACKGROUND: To evaluate the effect of nucleotide P2Y(2) receptor agonists INS542 and uridine 5'-triphosphate (UTP) on the outward active transport of fluorescein across rabbit blood-retina barrier (BRB) in vivo. METHODS: Injection (0.1 ml) of INS542 (0.1 or 1mM), phosphate buffered solution, or UTP (1 or 10mM) was made in Dutch-belted rabbits. Differential vitreous fluorophotometry (DVF) was performed 3hr later and the fluorescein (F)/fluorescein monoglucuronide (FG) ratio was then calculated. F/FG ratios are inversely proportional to outward active transport of F across BRB at the level of the retinal pigment epithelium (RPE). In another set of experiments, the effect of 0.1 ml vitreous injection of INS542 (1mM) on F/FG ratios was evaluated at different time points ranging from 0.5 to 48hr before conducting DVF. RESULTS: F/FG ratios obtained 3hr after intravitreal injection were as follows (mean+/-standard error): 0.49+/-0.14 (0.1mM INS542), 0.19+/-0.04 (1mM INS542), 0.48+/-0.09 (PBS), 0.40+/-0.08 (1mM UTP) and 0.36+/-0.05 (10mM UTP). The F/FG ratio for 1mM INS542 was significantly lower than in the other groups (P<0.05). In the time course experiments, a significant decrease in the F/FG ratios was observed between 1 and 12hr following administration of INS542 when compared with F/FG ratios obtained in the contralateral (untreated) eye. CONCLUSION: Intravitreal administration of INS542 (but not UTP) enhances outward active transport of F across RPE in intact rabbit eye, indicating that activation of P2Y(2) receptors in vivo directly stimulates RPE active transport.


Subject(s)
Blood-Retinal Barrier/drug effects , Purinergic P2 Receptor Agonists , Animals , Biological Transport, Active/drug effects , Biological Transport, Active/physiology , Blood-Retinal Barrier/physiology , Fluorescein/pharmacokinetics , Fluorophotometry/methods , Male , Pigment Epithelium of Eye/metabolism , Rabbits , Receptors, Purinergic P2/physiology , Receptors, Purinergic P2Y2 , Uridine Triphosphate/pharmacology
14.
Nippon Ganka Gakkai Zasshi ; 107(11): 674-7, 2003 Nov.
Article in Japanese | MEDLINE | ID: mdl-14661540

ABSTRACT

BACKGROUND: The determination of pulsatile ocular blood flow (POBF) by measuring intraocular pressure pulse is a reliable way of evaluating choroidal blood flow. METHODS: We studied ocular haemodynamic abnormalities by examining the choroidal blood flow using POBF in patients with age-related macular degeneration (AMD). RESULTS: POBF was lower in patients with exudative AMD than in patients with non-exudative AMD and normal subjects. CONCLUSION: The decreased choroidal blood flow may induce choroidal neovascularization via angiogenic factor induced by hypoxia in patients with exudative AMD. Further studies of choroidal circulation, which may be important for the understanding the mechanism of AMD, are needed.


Subject(s)
Choroid/blood supply , Eye/blood supply , Macular Degeneration/physiopathology , Female , Humans , Male , Pulsatile Flow/physiology
16.
Invest Ophthalmol Vis Sci ; 44(11): 4947-53, 2003 Nov.
Article in English | MEDLINE | ID: mdl-14578421

ABSTRACT

PURPOSE: To investigate whether nitric oxide (NO) contributes to the regulation of retinal circulation during hypercapnia in cats. METHODS: NG-nitro-L-arginine-methylester (L-NAME; n=8), a NOS inhibitor; NG-nitro-D-arginine-methylester (D-NAME; n=6), the inactive isomer; or phosphate-buffered saline (PBS; n=8) was injected intravitreously into the cat's eye. A selective neuronal nitric oxide synthase (nNOS) inhibitor, 7-nitroindazole (7-NI; n=6), was injected intraperitoneally. Hypercapnia was induced for 10 minutes by inhalation of 5% carbon dioxide with 21% oxygen and 74% nitrogen. The vessel diameter and blood velocity were measured simultaneously in large retinal arterioles in cats by laser Doppler velocimetry and the retinal blood flow (RBF) calculated. Retinal vascular resistance (RVR) was also estimated. RESULTS: In the PBS group, the vessel diameter (9.5% +/- 2.7%, P<0.05), blood velocity (15.6% +/- 4.4%, P<0.05), and RBF (37.2% +/- 3.7%, P<0.05) increased, and the RVR decreased (-26.0% +/- 2.7%, P<0.05) during hypercapnia. In the L-NAME group, those changes were greatly suppressed in response to hypercapnia. D-NAME was inactive with regard to RBF during hypercapnia. The RBF responses to hypercapnia after the 7-NI injection were significantly attenuated compared with those before 7-NI injection (P<0.05). CONCLUSIONS: These results indicate that NO contributes to the increase in RBF during hypercapnia. Furthermore, the NO synthesized by the action of nNOS may participate in regulation of RBF during hypercapnia.


Subject(s)
Hypercapnia/physiopathology , Nitric Oxide/physiology , Retinal Artery/physiology , Animals , Blood Flow Velocity , Cats , Enzyme Inhibitors/pharmacology , Indazoles/pharmacology , Injections , Injections, Intraperitoneal , Laser-Doppler Flowmetry , NG-Nitroarginine Methyl Ester/pharmacology , Nitric Oxide Synthase/antagonists & inhibitors , Nitric Oxide Synthase Type I , Nitric Oxide Synthase Type II , Regional Blood Flow/physiology , Vitreous Body
17.
Ophthalmic Res ; 35(5): 276-80, 2003.
Article in English | MEDLINE | ID: mdl-12920341

ABSTRACT

PURPOSE: To investigate the effect of latanoprost (LP) on the inward and outward permeability (Pin and Pout) of the blood-retinal barrier (BRB). METHODS: Four New Zealand white rabbits received topical LP (0.005%) once daily for 3 weeks in one eye and phosphate-buffered saline (PBS) in the fellow eye (topical group). Five New Zealand white rabbits were injected intravitreously with LP (0.1 ml, 0.005%) in one eye and PBS (0.1 ml) in the fellow eye (injection group). In the injection group, vitreous fluorophotometry (VFP) to estimate the Pin and differential vitreous fluorophotometry (DVF) to estimate the Pout were performed 60 min after LP was injected. After the baseline measurements, VFP and DVF were performed 60 and 180 min after intravenous injection of sodium fluorescein, respectively. Fluorescein (F) and fluorescein monoglucuronide (FG) concentrations were obtained by DVF, and the F/FG ratio was calculated as an index of the Pout. RESULTS: In the topical group, there were no significant differences in the Pin or F/FG ratio between the LP- and the PBS-treated eyes. In the injection group, the Pin in the LP-treated eyes was significantly higher than in PBS-treated eyes (p < 0.05). There was no significant difference in the F/FG ratio between the two groups. CONCLUSION: Although we cannot exclude the effect of differences in species, the physiologic effect of LP, which increased the Pin, was seen in experimental studies. Because antiglaucoma drugs are generally used over an extended period, further clinical studies of the effect of LP on the BRB should be performed in patients who have BRB breakdown, such as in uveitis, and in patients who are pseudophakic and aphakic.


Subject(s)
Antihypertensive Agents/pharmacology , Blood-Retinal Barrier/physiology , Prostaglandins F, Synthetic/pharmacology , Retinal Vessels/physiology , Administration, Topical , Animals , Biological Transport, Active/drug effects , Capillary Permeability/drug effects , Contrast Media/metabolism , Fluorescein/metabolism , Fluorophotometry/methods , Injections , Latanoprost , Rabbits , Vitreous Body/metabolism
18.
Am J Ophthalmol ; 135(3): 356-61, 2003 Mar.
Article in English | MEDLINE | ID: mdl-12614754

ABSTRACT

PURPOSE: To describe a newly developed stabilized retinal laser Doppler instrument, to report the reproducibility of retinal blood flow measurements, and to present examples of its clinical application. DESIGN: Experimental study. METHODS: The intrasession, intersession, and interobserver reproducibility of retinal blood flow measurements obtained using the Canon Laser Blood Flowmeter model CLBF 100 was assessed. Intrasession: the coefficients of variation (CV) for repeated measurements (5X) of retinal vessel diameter (D), time-average centerline blood velocity (V(av)), and blood flow (F) were calculated at 18 sites along temporal retinal arteries and 18 sites along temporal retinal veins using both eyes in six healthy volunteers. Intersession: the correlation coefficients and average differences between two sets of measurements at the same 36 retinal sites made by one examiner on two different days were calculated. Interobserver: the correlation coefficients and average differences between two sets of measurements at nine sites (five arterial and four venous) in five eyes of five of the volunteers made by two examiners on the same day were calculated. Results from two patients, one with branch retinal vein occlusion (BRVO), and one with central retinal vein occlusion (CRVO), are used to illustrate abnormal retinal circulatory characteristics. RESULTS: intrasession: CV (mean +/- SD) for D, V(av), and F were 5.5% +/- 2.2%, 13.1% +/- 6.3%, and 13.8% +/- 4.7% in arteries and 3.5% +/- 2.1%, 11.9% +/- 5.9%, and 12.7% +/- 5.5% in veins. Intersession/interobserver: strong correlations between measurements made by one examiner on two different days and by two examiners on the same day were found in D, V(av), and F. Average differences in F were 16.4% +/- 12.8% for intersession and 12.6% +/- 7.0% for interobserver comparisons. Results from the patient with BRVO show marked differences in flow characteristics in the affected quadrant compared with an unaffected quadrant in the same eye, and to the fellow eye. Results from the patient with CRVO show a dramatic improvement in flow characteristics after clearing of the occlusion. CONCLUSIONS: The reproducibility results and the fact that blood flow is measured in actual units of microl/min indicate that the instrument can be used for reliable comparison of blood flow characteristics at different retinal vascular sites in the same eye, at comparable sites in both eyes, and for comparison between patients and healthy control subjects.


Subject(s)
Laser-Doppler Flowmetry/methods , Retinal Artery Occlusion/physiopathology , Retinal Artery/physiology , Retinal Vein Occlusion/physiopathology , Retinal Vein/physiology , Adult , Blood Flow Velocity , Diagnostic Techniques, Ophthalmological/instrumentation , Female , Humans , Laser-Doppler Flowmetry/instrumentation , Male , Middle Aged , Observer Variation , Regional Blood Flow/physiology , Reproducibility of Results
19.
J Colloid Interface Sci ; 264(2): 378-84, 2003 Aug 15.
Article in English | MEDLINE | ID: mdl-16256654

ABSTRACT

A peroxo niobic acid sol was prepared by peptization of the niobic acid precipitate (Nb2O5.nH2O) with a H2O2 aqueous solution. Crystallized Nb2O5 nanoparticles and niobic acid nanoparticles were obtained by heating the peroxo niobic acid sol. When peroxo niobic acid sol prepared by peptization of the niobic acid precipitate ([NH3]=0.3 mol/l) was heated at 348 K for 1 week, Nb2O5 nanoparticles with a diameter of 4.5 nm and a S(BET) of 275 m2/g were obtained. When peroxo niobic acid sol prepared by peptization of the niobic acid precipitate ([NH3]=1 mol/l) was heated at 348 K for 1 week, niobic acid nanoparticles with a diameter of less than 2 nm were obtained. The pore structure and degree of crystallinity of the nanoparticles prepared by heating the peroxo niobic acid sol greatly depended on the concentration of the ammonia solution used for preparing the niobic acid precipitate.

20.
Ophthalmology ; 109(11): 2160-4, 2002 Nov.
Article in English | MEDLINE | ID: mdl-12414433

ABSTRACT

OBJECTIVE: To investigate the relationship between preoperative photoreceptor displacement and postoperative scotoma after unilateral idiopathic macular hole surgery. DESIGN: Prospective nonrandomized comparative self-controlled trial. PARTICIPANTS: Twenty patients who underwent successful surgery for unilateral idiopathic macular hole participated in the study. METHODS: Kinetic perimetry using red and green filter glasses, black binocular fixation targets, and red and green selective monocular stimuli was performed preoperatively. Scanning laser ophthalmoscope (SLO) microperimetry was performed preoperatively and postoperatively. RESULTS: Sixteen patients had photoreceptor displacement preoperatively. In preoperative SLO microperimetry, all eyes with a macular hole had a scotoma; postoperatively, 12 of 16 had no scotoma. All four eyes with no preoperative photoreceptor displacement were noted to have a postoperative scotoma. The prevalence of postoperative scotoma in patients with preoperative photoreceptor displacement (4 of 16; 25%) was significantly lower than that in patients without preoperative photoreceptor displacement (4 of 4; 100%) (P = 0.03). CONCLUSIONS: The presence or absence of photoreceptor displacement preoperatively should affect postsurgical visual function. Photoreceptor damage may occur in eyes without photoreceptor displacement preoperatively, resulting in scotoma postoperatively.


Subject(s)
Photoreceptor Cells, Vertebrate/physiology , Retinal Perforations/physiopathology , Retinal Perforations/surgery , Scotoma/physiopathology , Aged , Female , Humans , Male , Middle Aged , Preoperative Care , Vision, Binocular , Visual Acuity/physiology , Visual Field Tests , Visual Fields/physiology
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