Asymmetric public goods game cooperation through pest control

Cooperation in a public goods game has been studied extensively to find the conditions for sustaining the commons, yet the effect of asymmetry between agents has been explored very little. Here we study a game theoretic model of cooperation for pest control among farmers. In our simple model, each farmer has a paddy of the same size arranged adjacently on a line. A pest outbreak occurs at an abandoned paddy at one end of the line, directly threatening the frontier farmer adjacent to it. Each farmer pays a cost of his or her choice to an agricultural collective, and the total sum held by the collective is used for pest control, with success probability increasing with the sum. Because the farmers' incentives depend on their distance from the pest outbreak, our model is an asymmetric public goods game. We derive each farmer's cost strategy at the Nash equilibrium. We find that asymmetry among farmers leads to a few unexpected outcomes. The individual costs at the equilibrium do not necessarily increase with how much the future is valued but rather show threshold behavior. Moreover, an increase in the number of farmers can sometimes paradoxically undermine pest prevention. A comparison with a symmetric public goods game model reveals that the farmer at the greatest risk pays a disproportionate amount of cost in the asymmetric game, making the use of agricultural lands less sustainable.

Evolutionary emergence and maintenance of horizontally transmitted mutualism that do not rely on the supply of standing variation in symbiont quality

Mutualism based on reciprocal exchange of costly services must avoid exploitation by 'free-rides'. Accordingly, hosts discriminate against free-riding symbionts in many mutualistic relationships. However, as the selective advantage of discriminators comes from the presence of variability in symbiont quality that they eliminate, discrimination and thus mutualism have been considered to be maintained with exogenous supply of free-riders. In this study, we tried to resolve the 'paradoxical' co-evolution of discrimination by hosts and cooperation by symbionts, by comparing two different types of discrimination: 'one-shot' discrimination, where a host does not reacquire new symbionts after evicting free-riders, and 'resampling' discrimination, where a host does from the environment. Our study shows that this apparently minor difference in discrimination types leads to qualitatively different evolutionary outcomes. First, although it has been usually considered that the benefit of discriminators is derived from the variability of symbiont quality, the benefit of a certain type of discriminators (e.g. one-shot discrimination) is proportional to the frequency of free-riders, which is in stark contrast to the case of resampling discrimination. As a result, one-shot discriminators can invade the free-rider/nondiscriminator population, even if standing variation for symbiont quality is absent. Second, our one-shot discriminators can also be maintained without exogenous supply of free-riders and hence is free from the paradox of discrimination. Therefore, our result indicates that the paradox is not a common feature of evolution of discrimination but is a problem of specific types of discrimination.

ARIX gene polymorphisms in patients with congenital superior oblique muscle palsy

AIM

To identify ARIX gene polymorphisms in patients with congenital superior oblique muscle palsy and to find the relation between the ARIX gene and congenital superior oblique muscle palsy.

METHODS

The three exons of the ARIX gene were sequenced by genomic DNA amplification with polymerase chain reaction (PCR) and direct sequencing in 15 patients with superior oblique muscle palsy (13 with congenital and two with acquired palsy) and 54 normal individuals. PCR products cloned into plasmids were also sequenced. A family with father and a daughter each having congenital superior oblique muscle palsy was also involved in this study.

RESULTS

Four patients with congenital superior oblique muscle palsy carried heterozygous nucleotide changes in the ARIX gene. One patient with the absence of the superior oblique muscle had T7C in the 5'-UTR of the exon 1 and C-44A in the promoter region, both of which were located on the same strand. Another unrelated patient with congenital superior oblique muscle palsy had C76G in the 5'-UTR of the exon 1 and C-9A in the promoter region on the same strand. G153A in the 5'-UTR of exon 1 was found in common in two affected members of a family with congenital superior oblique muscle palsy. This G153A in the 5'-UTR of exon 1 was also present in four unrelated normal individuals. No other heterozygous nucleotide changes were found in normal individuals.

CONCLUSIONS

The nucleotide change (G153A) in the 5'-UTR of exon 1 co-segregated with congenital superior oblique muscle palsy in one family. Four other nucleotide changes in the exon 1 or the promoter region were found only in patients with congenital superior oblique muscle palsy. These nucleotide polymorphisms may be one of the risk factors for the development of congenital superior oblique muscle palsy.

TIMP-1 production by bovine retinal pigment epithelial cells increases in response to cyclic mechanical stretch

PURPOSE

The effect of mechanical stretch was examined on cultured retinal pigment epithelial (RPE) cells in order to observe changes in their production of tissue inhibitor of metalloproteinase-1 (TIMP-1) and vascular endothelial growth factor (VEGF) in response to physiological strain.

METHODS

Bovine RPE cells in near-confluent culture were exposed to mechanical stretch of the bottom of a 6-cm petri dish at the maximum magnitude of 4500 microstrain and at a cycle of 30 seconds for 72 hours. TIMP-1 and VEGF levels in the medium following 24, 48, and 72 hours of cyclic stretch were measured by enzyme immunoassay.

RESULTS

The growth of RPE cells during the 72-hour period of stretching did not show a significant difference from that of nonstretched control cells. RPE cells in the stretched group produced a significantly larger amount of TIMP-1 at 48 and 72 hours after stretch, compared with nonstretched control (P =.044 and P =.027, respectively, Student t-test). The levels of VEGF produced by RPE cells were not significantly different between the stretched group and nonstretched control group.

CONCLUSIONS

The secretion of TIMP-1 by bovine RPE cells was enhanced by cyclic mechanical stretch. Mechanical strain is one factor in regulating the secretion of TIMP-1 by RPE cells.

Clinical, histopathological, and immunogenetic analysis of ocular adnexal lymphoproliferative disorders: characterization of malt lymphoma and reactive lymphoid hyperplasia

Malignant lymphomas and reactive lymphoid hyperplasia (RLH) in the ocular adnexa are sometimes difficult to differentiate morphologically and have often been categorized together as a lymphoproliferative disorder. Immunogenotypic characters of these diseases have not yet been well clarified. This study included 76 cases of ocular adnexal lymphoproliferative disorders. These consisted of 52 cases of malignant lymphoma (43 primary and 9 secondary), 22 of RLH, and 2 borderline cases. There were slightly more male than female subjects. Diagnoses were based on morphology and immunophenotypic characteristics. Clonalities were detected by means of polymerase chain reaction (PCR), and immunoglobulin heavy-chain variable region (VH) genes were sequenced in 10 cases of mucosa-associated lymphoid tissue (MALT) lymphoma. MALT lymphoma constituted 86% (37 cases) of the primary lymphomas. MALT lymphomas were more indolent, more rarely disseminated, and had a lower death rate than the other primary lymphomas. Two patients exhibited coexistence of MALT and diffuse large B-cell lymphoma. The average age of patients with RLH was 5.5 years younger than that of those with MALT lymphoma. One of the cases of RLH later progressed to malignant lymphoma. B-cell clonality was detected by PCR in 57%, 55%, and 0% of primary lymphomas, MALT lymphomas and RLHs, respectively. Sequencing of VH genes revealed that the VH3 family was the most commonly expressed germline VH family (70%) and that DP-63, DP-54 and DP-47 genes were frequently found in the MALT lymphomas examined. PCR analysis was useful for differentiation between MALT lymphoma and RLH. Sequence analysis of VH genes showed that an autoimmune mechanism may be involved in the lymphomagenesis of ocular adnexal MALT lymphoma.

Retinal cells produce TIMP-1 and TIMP-2 in response to cyclic mechanical stretching

PURPOSE

Tissue inhibitors of metalloproteinases (TIMPs) are crucial for the maintenance of retinal extracellular matrix such as interphotoreceptor matrix and internal limiting membrane. This study is to examine whether retinal cells respond to mechanical stretching and produce TIMPs.

METHODS

Chick retinal adherent cells in near confluency were exposed to mechanical stretching of the bottom of a 6-cm Petri dish at the maximum magnitude of 4,500 microstrain and at a cycle of 30 s for 72 h. TIMP-1 and TIMP-2 levels in the medium at 24, 48 and 72 h after the beginning of stretching were measured by enzyme immunoassay, and their expression was examined by immunohistochemistry.

RESULTS

The number of retinal cells during the 72-hour period of stretching did not change significantly both in the stretched group and in the nonstretched control group. Retinal cells in the stretched group produced significantly larger amounts of TIMP-1 and TIMP-2 at 48 h after stretching, compared with nonstretched controls (p = 0.0163 and p = 0.047, respectively, Mann-Whitney U test). Immunohistochemically, a large part of retinal cells in nonstretched Petri dishes was positive for glial fibrillary acidic protein, indicative of glial cells, while some small foci of cells were positive for neuron-specific enolase, indicative of neurons. Fluorescent double labeling demonstrated that both glial cells and neurons were positive for TIMP-1 and TIMP-2.

CONCLUSION

Chick retinal cells, most of which were glial cells mixed with a small number of neurons, produced TIMP-1 and TIMP-2. Their production was enhanced by cyclic mechanical stretching.

Heredity versus abnormalities in pregnancy and delivery as risk factors for different types of comitant strabismus

PURPOSE

To elucidate risk factors for different types of comitant strabismus, the incidence of heredity and abnormalities in pregnancy and delivery was compared among different types of strabismus.

METHODS

Between May 1998 and January 1999, a prospective clinical study of 500 consecutive patients with comitant strabismus at a referral-based university hospital was performed using data collected from questionnaires and interviews. Inclusion criteria were infantile esotropia (168 patients), accommodative and partially accommodative esotropia (97 patients), microesotropia (15 patients), acquired esotropia (12 patients), intermittent or constant exotropia (205 patients), and congenital exotropia (3 patients). Exclusion criteria were strabismus associated with systemic and central nervous system abnormalities and organic eye diseases.

RESULTS

Family history was significantly more prevalent in intermittent or constant exotropia and accommodative or partially accommodative esotropia than in infantile esotropia (P<.0001 and P=.0267, respectively, Fisher's exact test). In contrast, abnormalities in pregnancy and delivery were noted at a significantly higher rate in infantile esotropia than in accommodative or partially accommodative and in intermittent or constant exotropia (P=.003 and P=.0215, respectively). Patients with infantile esotropia were significantly younger at the survey than those with the other two types of strabismus (P=.0004 and P<.0001). No significant difference was found in the number of siblings, birthweight, maternal age at delivery, or maternal cigarette smoking or alcohol drinking among these three types of strabismus.

CONCLUSION

Heredity and abnormalities in pregnancy and delivery are two major risk factors for comitant strabismus and contribute at different levels to the development of infantile esotropia, accommodative or partially accommodative esotropia, and intermittent or constant exotropia.

TIMP-1 production by human scleral fibroblast decreases in response to cyclic mechanical stretching

PURPOSE

The effect of mechanical stretching was examined on cultured scleral fibroblasts of the human eye in order to observe changes in their production of TIMP (tissue inhibitor of metalloproteinase)-1, MMP (matrix metalloproteinase)-1 and -2 in response to physiological strain.

METHODS

Human scleral fibroblasts were cultured from scleral tissue resected during foveal translocation surgery. The fibroblasts in near confluency were exposed to mechanical stretching of the bottom of a 6-cm Petri dish at the maximum magnitude of 4500 microstrain and at a cycle of 30 s for 72 h. TIMP-1, MMP-1 and MMP-2 levels in the medium following 24, 48 and 72 h of cyclic stretching were measured by enzyme immunoassay.

RESULTS

The growth of scleral fibroblasts during the 72-hour period of stretching did not show a significant difference from that of non-stretched control fibroblasts. Scleral fibroblasts in the stretched group produced a significantly smaller amount of TIMP-1 at 72 h after stretching, compared with nonstretched control (p = 0.0353, Student t-test). The levels of MMP-1 and MMP-2 produced by scleral fibroblasts were not significantly different between the stretched group and nonstretched group.

CONCLUSION

The production of TIMP-1 by human scleral fibroblasts was suppressed by cyclic mechanical stretching. Mechanical strain would be one factor to regulate the homeostasis of extracellular matrix in the sclera.

Correction of cyclovertical strabismus induced by limited macular translocation in a case of age-related macular degeneration

PURPOSE

To report a case of strabismus surgery performed to treat cyclovertical strabismus induced by limited macular translocation.

METHODS

Case report.

RESULTS

A 62-year-old man suffering with age-related macular degeneration and subfoveal choroidal neovascularization, RE, underwent limited macular translocation surgery. The fovea was rotated downward, and his visual acuity improved from 20/100 to 20/25 postoperatively. Cyclovertical diplopia persisted for 6 months after the operation. A Hess screen test revealed a pattern that simulated an underaction of the superior oblique muscle and inferior rectus muscle with an overaction of the ipsilateral inferior oblique muscle. To treat the diplopia, advancement of the superior oblique muscle tendon and resection of the ipsilateral inferior rectus muscle were performed. Binocular single vision with 140 seconds of arc for stereopsis was obtained.

CONCLUSION

Cyclovertical strabismus after limited macular translocation is corrective with conventional surgery on the treated eye.

Prism adaptation response is useful for predicting surgical outcome in selected types of intermittent exotropia

PURPOSE

To evaluate the prevalence of prism adaptation response in Japanese patients with intermittent exotropia (X [T]) using the prism adaptation test and to assess whether patients with selected types of X [T] benefit from surgical outcome to which prism adaptation response may contribute.

METHODS

In a prospective study, 128 consecutive patients with X [T] between 1990 and 1995 were enrolled. The prism adaptation test was conducted by neutralizing the angle of deviation for 2 to 3 hours. Patients who showed an increase in exodeviation by 10triangle up or more with the prism adaptation test were defined as having a prism adaptation response. For classification of the pattern of X [T], we chose a value of 15triangle up as the difference between the distance and near measurements.

RESULTS

The percentage of patients in whom the prism adaptation response was observed at near fixation was significantly larger than those at distance fixation [35 (27%) patients versus 10 (8%) patients, P <.05]. Of 35 patients shown to have a prism adaptation response at near fixation, 21 patients (83%) had the basic type of exotropia. Fourteen patients (17%) with the basic type were changed to convergence insufficiency type because of an increase in near deviation and were defined as pseudo basic type. Patients with pseudo basic type had a significantly better surgical outcome compared with that of true basic type, whereas in the convergence insufficiency type, no definite tendency was found between the two subtypes, true and pseudo types.

CONCLUSION

Patients with the pseudo basic type of X [T] in whom a prism adaptation response was demonstrated had a more favorable surgical outcome.

Large Bielschowsky head-tilt phenomenon and inconspicuous vertical deviation in the diagnostic positions in congenital superior oblique palsy

PURPOSE

To report a case of congenital superior oblique palsy with an unusually large Bielschowsky head-tilt phenomenon (BHP) and disproportional inconspicuous vertical deviation.

METHODS

Case report.

RESULTS

An 18-year-old woman presented with slight compensatory head tilting and a Bielschowsky head-tilt phenomenon of 50 Delta on left tilting. Magnetic resonance imaging revealed atrophy of the left superior oblique muscle. A Hess screen test showed a slight underaction of the left superior oblique muscle, but neither an obvious overaction of the ipsilateral inferior oblique muscle nor inhibitory palsy of the contralateral superior rectus muscle was found. With a 3-mm recession of the ipsilateral superior rectus muscle, Bielschowsky head-tilt phenomenon decreased to 25 Delta.

CONCLUSION

A large Bielschowsky head-tilt phenomenon was possibly caused by an increased gain of the otolith-ocular reflex affecting the vertical rectus muscle.

Morphological changes in the orbital surface layer muscle of the rabbit eye produced by botulinum toxin

We quantitated the morphological changes in the orbital surface layer muscles in the rabbit following the single injection of botulinum A toxin. Experiments were performed in 9 white rabbits (1.6-3.0 kg). They were administered 5 units (5 rabbits) or 10 units (4 rabbits) of botulinum toxin injected into the superior rectus muscle of one eye. The diameter of myofibers of the orbital and intermediate layer zones was measured with an ocular micrometer on histological sections 3 days and 1, 3 and 5 weeks after injection. Quantitative changes were noted in the muscle fibers of the orbital surface layer zone following the injection of 10 units of botulinum toxin. At 1 week, the diameter of myofibers in the orbital layer was reduced, but it was increased at 5 weeks compared to that in the control eyes; in contrast, no change in the diameter of muscle fibers was found in the intermediate layer zone.

Novel sugar-binding specificity of the type XIII xylan-binding domain of a family F/10 xylanase from Streptomyces olivaceoviridis E-86

The type XIII xylan-binding domain (XBD) of a family F/10 xylanase (FXYN) from Streptomyces olivaceoviridis E-86 was found to be structurally similar to the ricin B chain which recognizes the non-reducing end of galactose and specifically binds to galactose containing sugars. The crystal structure of XBD [Fujimoto, Z. et al. (2000) J. Mol. Biol. 300, 575-585] indicated that the whole structure of XBD is very similar to the ricin B chain and the amino acids which form the galactose-binding sites are highly conserved between the XBD and the ricin B chain. However, our investigation of the binding abilities of wt FXYN and its truncated mutants towards xylan demonstrated that the XBD bound xylose-based polysaccharides. Moreover, it was found that the sugar-binding unit of the XBD was a trimer, which was demonstrated in a releasing assay using sugar ranging in size from xylose to xyloheptaose. These results indicated that the binding specificity of the XBD was different from those of the same family lectins such as the ricin B chain. Somewhat surprisingly, it was found that lactose could release the XBD from insoluble xylan to a level half of that observed for xylobiose, indicating that the XBD also possessed the same galactose recognition site as the ricin B chain. It appears that the sugar-binding pocket of the XBD has evolved from the ancient ricin super family lectins to bind additional sugar targets, resulting in the differences observed in the sugar-binding specificities between the lectin group (containing the ricin B chain) and the enzyme group.

A novel gene (retinovin) expressed selectively in the early stage of chick retinal development

To understand molecular mechanisms of retinal development, genes expressed selectively only in the early stage of retinal development were isolated by subtractive hybridization based on suppression polymerase chain reaction. The retina has no layered structure in 7-day chick embryos, in contrast with the fully developed multilayered structure of neurons in 15-day embryos. The subtraction between cDNA derived from retinal tissues at these different stages, followed by repeat rounds of 5'-RACE (rapid amplification of cDNA ends) and 3'-RACE, led to isolation of a novel gene with an open reading frame encoding a putative protein with 753 amino acids. Its specific expression in the 7-day embryonic retina was confirmed by Northern blot analysis. The gene, named "retinovin," would be used as a marker for identifying retinal stem cells present at the early stage of retinal development.

Evaluation of leukocyte dynamics in choroidal circulation with indocyanine green-stained leukocytes

PURPOSE

To develop a new method with which to visualize leukocytes moving through the choroidal vessels of pigmented animals and enable the evaluation of leukocyte dynamics in the choroidal microcirculation.

METHODS

Pigmented rabbits and monkeys were used in this study. Leukocytes, collected by centrifugal separation of autologous blood, were stained with indocyanine green (ICG) dye. The ICG-stained leukocyte fluid was injected into the vein, and the fundus image was obtained with a scanning laser ophthalmoscope. The image was recorded on videotapes and analyzed with a personal computer-based image analysis system.

RESULTS

In pigmented rabbits, fluorescent leukocytes moving in the choroidal circulation were clearly visible for more than 1 hour. In monkeys, distinct fluorescent dots were seen moving approximately 50 to 200 microm in the foveal avascular zone for more than 30 minutes after the injection of the ICG-stained leukocyte fluid. Dim fluorescent dots were seen moving in the fundus. Although the movement of these dim dots was difficult to trace, they seemed to be moving in the choroidal vessels. In the rabbits, the mean flow velocity of leukocytes moving without plugging was 0.48 +/- 0.14 mm/sec in the peripheral choriocapillaris. In the monkeys, the mean flow velocity of distinct fluorescent leukocytes without plugging was 2.45 +/- 0. 48 mm/sec in the posterior choroid.

CONCLUSIONS

In pigmented rabbits and monkeys, this method allows visualization of leukocytes passing through the choroidal vessels and provides a new way to investigate, noninvasively and in vivo, leukocyte dynamics in the choroidal microcirculation.

Comparative study of brain lesions detected by magnetic resonance imaging between strabismus and nonstrabismus in infancy

PURPOSE

To elucidate the causative factors in infantile esotropia, we evaluated morphological abnormalities in brain structures of esotropia patients showing any abnormal neurological signs in comparison to those of normal controls.

METHODS

Sixty-five developmentally normal children participated in this study. Of these 65, 38 demonstrated infantile esotropia and 27 were normal controls. All underwent magnetic resonance imaging (MRI) of the brain between 2 and 30 months.

RESULTS

Abnormal brain findings were noted in 3 (7. 9%) children in the strabismus group, whereas none of the children in the normal control group showed brain lesions. In these 3 cases, brain lesions involved periventricular leukomalacia, enlargement of the lateral ventricles with hypoplasia of the corpus callosum and myelination delay at the anterior horn adjacent to the lateral ventricles.

CONCLUSIONS

Brain lesions that may disturb normal maturation of the visuomotor system and eventually lead to strabismus could be found in some patients without any episode that would cause birth injury.

Identification of ingrowth site of idiopathic subfoveal choroidal neovascularization by indocyanine green angiography

PURPOSE

This study aimed to determine whether indocyanine green (ICG) angiography is useful to identify the ingrowth site of idiopathic choroidal neovascularization (CNV), which can predict visual outcomes after surgical removal of idiopathic CNV.

DESIGN

Consecutive, observational case series.

PARTICIPANTS

Twenty-six patients with idiopathic subfoveal CNV, of whom six underwent submacular surgery.

INTERVENTION

Indocyanine green videoangiography with a scanning laser ophthalmoscope.

MAIN OUTCOME MEASURES

We studied ICG videoangiographic images of choroidal neovascular membranes from the early phase to the late phase with special attention to abnormal findings, which can indicate the ingrowth site of CNV.

RESULTS

Early ICG angiography demonstrated distinct neovascular vessels in 24 of the 26 patients (92%). Hypofluorescent rims continuously or intermittently surrounded neovascular membranes on late ICG angiograms in 21 of the 26 patients (81%). In 22 of the 26 patients (85%), ICG angiography demonstrated hypofluorescent areas within the CNV. These hypofluorescent areas frequently became ring shaped in the middle to late phase of the ICG angiography. In 14 of 16 patients (88%) with CNV larger than half a disc area, the filling of neovascular vessels appeared from the inside of the hypofluorescent areas and branched out toward the surrounding hyperfluorescent membrane in the early phase. In all six patients who underwent surgical removal of CNV, ICG videoangiography showed these hypofluorescent areas from which neovascular vessels emanated. Three of the four surgical patients, in whom hypofluorescent areas or central fluorescent areas surrounded by ring-shaped hypofluorescence were extrafoveal or juxtafoveal, had a best postoperative visual acuity of 20/60 or better. In contrast, both surgical patients with subfoveal hypofluorescent areas had a best postoperative visual acuity of 20/70 or worse.

CONCLUSIONS

Although further observations are needed, ICG angiography may be a useful adjunct in the identification of the ingrowth site of idiopathic CNV, which can predict visual outcomes after surgery.

Prognostic factors for successful surgical outcome with preoperative prism adaptation test in patients with superior oblique palsy

PURPOSE

This study evaluated the surgical outcome of patients managed with preoperative prism adaptation test (PAT) and investigated prognostic factors for successful motor alignment in adult patients with superior oblique palsy.

METHODS

Prospective study of preoperative PAT was performed. Fifty-seven patients with superior oblique palsy, aged 16 to 81 years, participated in this study. Patients were assigned to surgery with the target angle based on either the original angle or the prism compensated angle. When the amount of neutralizing prism exceeded 4delta or more compared to the original angle of deviation, the patient was defined as having prism compensation, and the target angle for surgery was based on the amount of neutralizing prism. The motor success rate was compared between the 2 groups at the 3-month postoperative follow-up.

RESULTS

The prism responders group showed a superior outcome compared to that of the prism non-responders group (77% successful outcome compared with 46%, p = 0.0397). The presence of prism compensation and the amount of vertical deviation were significant prognostic factors for successful motor alignment.

CONCLUSION

Preoperative PAT is a useful prognostic indicator of successful surgical outcome in patients with superior oblique palsy.

Surgical treatment of submacular hemorrhage associated with idiopathic polypoidal choroidal vasculopathy

PURPOSE

To report the visual outcome of surgical treatment of submacular hemorrhage associated with idiopathic polypoidal choroidal vasculopathy.

METHODS

Eight eyes of eight consecutive patients with thick submacular hemorrhages associated with idiopathic polypoidal choroidal vasculopathy were treated with pars plana vitrectomy and tissue plasminogen activator-assisted removal of subretinal blood (December 1995 to September 1997) or intravitreal 100% sulfur hexafluoride gas injection without tissue plasminogen activator (October 1997 to March 1998).

RESULTS

Postoperatively, laser treatment was performed for active polypoidal lesions outside the foveal avascular zone in four eyes. A retinal pigment epithelial tear was seen outside the foveal avascular zone in three eyes, and one eye developed a retinal detachment. The best-corrected visual acuity improved (by 3 or more lines) or stabilized in seven of the eight eyes. Four eyes had a final best-corrected visual acuity of 20/40 or better, and three eyes had a final best-corrected visual acuity of 20/50 to 20/200. In one eye, the visual acuity decreased from 20/100 to 20/500 because of the development of a subfoveal neovascular membrane. The membrane was excised, and histologic examination showed fibrovascular tissue between the retina and retinal pigment epithelium (type 2 pattern).

CONCLUSIONS

Surgical intervention may be of benefit in eyes with submacular hemorrhage associated with idiopathic polypoidal choroidal vasculopathy.

A novel gene (oculomedin) induced by mechanical stretching in human trabecular cells of the eye

To understand molecular mechanisms underlying the response to pressure in human trabecular cells of the eye, genes induced by cyclic mechanical stretching were isolated by subtractive hybridization assisted by polymerase chain reaction. A novel gene containing an Alu repetitive element in the 5' untranslated region was identified, and its expression was confirmed by Northern blot analysis to be stretch-specific in trabecular cells. The gene was also expressed in the retina, but not in the other tissues, including the brain. The gene encoded a putative small protein with 44 amino acids, which showed homology with neuromedin K. The putative novel protein was named as "oculomedin," and would be used as a candidate gene for glaucoma.

Biometric confirmation of the Hirschberg ratio in strabismic children

PURPOSE

In the Hirschberg eye position test, the ratio of strabismic angle to decentration of the corneal reflex is dependent on two biometric parameters of the eye: the radius of the corneal curvature and the depth of the anterior chamber. This study was designed to confirm whether the Hirschberg conversion ratio (HR) previously determined for adults can be used for children of various ages despite structural growth of the eye.

METHODS

For 262 eyes of 131 children with strabismus (age range, 6 months to 11 years), the radius of the corneal curvature was measured with an auto-keratometer and the anterior chamber depth with an A-scan ultrasound unit under general anesthesia before the surgery. Using these measurements, the HR was computed on the basis of a geometric model.

RESULTS

The calculated HR was constant across the age range, and the mean+/-SD was 19.9+/-1.9 prism diopters/mm (95% confidence interval, 16.1-23.6 prism diopters/mm). The ratios for the two eyes in each subject showed good correlation (R = 0.854, P = 0.0001). Neither of the biometric measurements was significantly correlated with age, although considerable scatter of the measurements was observed.

CONCLUSIONS

These results indicate that the averaged HR can be applied in children regardless of the patient's age, although intersubject variance of the ratio should be taken into account.

Characteristics and variability of vertical phoria adaptation in normal adults

We evaluated the characteristics of phoria adaptation for vertically induced retinal disparity. An adaptive change in the fusion-free ocular alignment, phoria adaptation, was measured with a computer-aided mirror haploscope at 10, 30, and 60 minutes after the start of wearing of a 3-prism-diopter base up prism by 35 normal subjects ranging in age from 21 to 67 years (mean: 37 years). The relationships between phoria adaptation and the subjects' age, the vertical fusional amplitude, the amount of heterophoria, and the starting time of the examination were evaluated. All subjects showed phoria adaptation, with the mean (+/- SD) degree of 0.78 +/- 0.28 degree, 0.96 +/- 0.26 degree and 1.02 +/- 0.30 degrees at 10, 30, and 60 minutes, respectively, after wearing the prism. The repeatability (95% confidence interval) for the measurements was less than +/- 0.24 degree. There was a significant correlation between the vertical fusional amplitude and the gain of phoria adaptation (at 10 and 60 minutes, P < 0.05). The gain of phoria adaptation measured at 60 minutes showed a significant decrease with age (P < 0.01). The results indicate that the time course of phoria adaptation in the vertical direction is similar to that in the horizontal direction and its gain differs considerably among subjects.

Bovine trabecular cells produce TIMP-1 and MMP-2 in response to mechanical stretching

Bovine trabecular cells in growth phase were exposed to cyclic mechanical stretching of the bottom of a culture dish at a cycle of 30 seconds for 72 hours. The stretched cells produced significantly larger amounts of metalloproteinase-2 (MMP-2) and tissue inhibitor of metalloproteinase-1 (TIMP-1) after 72 hours, compared with cells in nonstretched control. In contrast, TIMP-2 and MMP-9 levels were not influenced by mechanical stretching. Trabecular cells would modify extracellular matrix in response to such mechanical stimuli as bending of trabecular meshwork or aqueous flow by the production of TIMP-1 and MMP-2.

Aqueous vascular endothelial growth factor increases in anterior segment ischemia in rabbits

Both long posterior ciliary arteries were occluded or the three extraocular muscles were tenotomized to produce anterior segment ischemia in rabbits, and the aqueous levels of vascular endothelial growth factor (VEGF) were measured. The occlusion of both long posterior ciliary arteries led to clinical and histological anterior segment ischemia in varying degrees. The aqueous VEGF levels increased significantly compared with controls on all days examined (Mann-Whitney U test: day 1, P = 0.0039; day 4, P = 0.0065; day 7, P = 0.0039; day 14, P = 0.0104), while the levels at days 7 and 14 decreased significantly compared with those at day 4 (Wilcoxon signed-rank test; day 4 to day 7 and day 4 to day 14, P = 0.0464). In contrast, tenotomy of the three extraocular muscles resulted in no histological changes. The VEGF levels increased significantly compared with controls at day 1 and day 4 decreased significantly compared with those at day 1 (Wilcoxon signed-rank test, P = 0.0499). Aqueous VEGF levels represent the severity of anterior segment ischemia and could be used as an indicator for the extent of ischemia.

Is mitomycin effective in preventing muscle migration after hang-back recession in a rabbit model?

To investigate the effect of intraoperative mitomycin C (MMC) application on muscle insertion migration after adjustable surgery, hang-back recession was bilaterally performed for 4 mm on the inferior rectus muscle in 30 rabbits. The scleral wound of the insertion site of one eye of each pair was treated with a sponge soaked with a solution cotaining mitomycin at a concentration of either 0.4 or 1.0 mg/ml for 5 min. As a control, the contralateral eye was treated with a distilled-water-soaked sponge. Three, 6 and 12 weeks later, the distance from the anterior border of the reattached muscle to the original insertion was measured with in vivo and microscopic examination. Anterior migration of the muscle insertion was observed in both the MMC-treated and control eye. The measurement by the in vivo and histologic examinations revealed that MMC treatment did not significantly reduce the anterior migration relative to the control eye. Analysis of the time course in the MMC-treated eye revealed a significant increase during the observation period in anterior migration as measured by the histologic examination (p = 0.0267 for the 0.4 mg/ml group and p = 0.0408 for the 1.0 mg/ml group). Exposure to MMC has no significant inhibitory effect on the muscle migration compared to that in the control eyes.

Predictors of postoperative binocularity in adult strabismus

We evaluated postoperative binocularity in a retrospective study of 111 adult strabismus patients in order to identify the factors which influence the success of surgery for horizontal concomitant strabismus in adults. Selection criteria included minimum age of 15 years at time of surgery, and preoperative fusion impairment with both the Bagolini lens test and synoptophore. Logistic regression analysis was used to correlate patient factors and postoperative binocularity. We found that 52 (65%) of 80 patients with exotropia and 23 (74.2%) of 31 patients with esotropia achieved post operative fusion. Significant predictive factors in exotropia were absence of previous surgery; visual acuity of the deviating eye > 0.5; an increase in the spherical equivalent of the deviating eye, and normal retinal correspondence. Significant predictive factors in esotropia were fusion during prism adaptation, absence of infantile esotropia, and an increase in vertical deviation. The majority of adults with exotropia or esotropia can achieve binocularity after surgery for horizontal concomitant strabismus.

Comparison of surgical results of responders and non-responders to the prism adaptation test in intermittent exotropia

The data for 94 consecutive patients with intermittent exotropia of basic type, ranging from 20 to 40 prism diopters (delta), who preoperatively wore neutralizing prisms for 3 to 5 days, were studied retrospectively. The surgery in 43 patients in whom the amount of increase of angle was 4delta or less was based on the original angle (Group A), while that in 51 patients in whom the magnitude of increase was 5delta or more was based on the increased angle of deviation (Group B). Patients with initial deviation less than 30delta and patients younger than 7 years of age showed an increase of deviation with prism correction. There were no significant differences in surgical results between the two groups at 1 year, and at 3 years; although at 3 years satisfactory motor alignment and binocular function for single vision at distance was higher in Group B than that in Group A.

Microvascular change of the anterior eye segment after tenotomy in the rabbit

BACKGROUND

The microvascular changes secondary to anterior segment ischemia following tenotomy of the extraocular muscles have not been studied in the rabbit.

METHODS

Using scanning electron microscopy of methyl-methacrylate ocular microvascular luminal castings, the anterior eye segment vasculature after tenotomy was documented and compared to that after occlusion of the bilateral long posterior ciliary arteries and that in the eyes that were not subjected to any surgical intervention.

RESULTS

Five days and 1 week after the surgical intervention with tenotomy, microvascular change secondary to the anterior segment ischemia was not apparent, but 2 weeks after the tenotomy subtle evidence of ischemia such as new vessels in the iris was observed. Seven weeks after tenotomy, marked microvascular change was observed where corneal new vessels arose from the superior perilimbal arteries. In contrast, we found prominent microvascular changes 2 weeks after the occlusion of the long posterior ciliary arteries.

CONCLUSIONS

Tenotomy of the rabbit eye causes microvascular change similar to that in occlusion of the long posterior ciliary arteries. This result suggests that the anterior ciliary artery of the rabbit contributes blood flow to the anterior eye segment and also has a stronger connection with the long posterior ciliary artery than previously reported.

Clinical studies of ocular motility disturbances: Part 2. Risk factors for ischemic ocular motor nerve palsy [corrected]

A case-control study of 46 Japanese patients who were diagnosed by exclusion as having ischemic ocular motor nerve palsy and who exhibited spontaneous recovery within 4 months was done to evaluate the risk factors involved. We also evaluated the association between the number of risk factors and the spontaneous recovery or recurrence periods. Ischemic ocular motor nerve palsy is closely related to diabetes mellitus and coronary artery disease. Patients tended to be obese; many had two or more risk factors. Aging, in combination with two or more risk factors, seems to increase the likelihood of developing this disease. Diabetes mellitus is a particularly significant risk factor for this type of palsy, especially in combination with hypertension.

Preoperative factors influencing effectiveness of surgery in adult strabismus

To identify preoperative factors which influence the effectiveness of strabismus surgery in adults, we retrospectively reviewed the records of 179 patients > 15 years old (131 with exotropia, 48 with esotropia) who had had combined recession and resection surgery for correction of horizontal strabismus. Eighteen preoperative variables were evaluated; those with significant influence on the surgical outcome, measured by the degree of change in deviation per millimeter of surgery, were identified by stepwise regression analysis. In patients with exotropia, preoperative distance deviation and average spherical equivalent were significant predictors of outcome at both 1 month (multiple R, 0.37) and 6 months (0.63) after surgery. In esotropic patients, significant variables at 1 month (multiple R, 0.57) and 6 months (0.77) were preoperative distance deviation and dissociated vertical deviation (DVD). Preoperative distance deviation is the common significant influence on surgical effectiveness for horizontal strabismus in adults, for both exotropia and esotropia. Additional significant predictors are average spherical equivalents in exotropic patients, and DVD in esotropic patients.

Effect of balancing-side occlusion on the ipsilateral TMJ dynamics under clenching

The effect of balancing-side occlusal contact patterns on ipsilateral TMJ dynamics was evaluated in this study. Vertical displacement of the balancing-side lower second molar during clenching at canine edge-to-edge position, with 0 and 1 mm of inter-canine distance, was measured for 42 normal subjects in relation to their balancing-side occlusal contact. Balancing-side occlusal contact was classified into four following patterns; (1) simultaneous balancing-side and working-side contact (without clenching); (2) balancing-side contact (with clenching only); (3) no balancing-side contact (with or without clenching); and (4) exclusive balancing-side contact (no working-side contact). The vertical displacement of the balancing-side condyle, calculated from the displacement of the balancing-side second molar, showed three different types of displacement pattern. These three types showed distinctive incidence in relation to the pattern of balancing-side occlusal contact. It was revealed that balancing-side occlusal contact can affect the ipsilateral TMJ dynamics.

Strabismus surgery in ocular myasthenia gravis

We evaluated the efficacy of eye muscle surgery in 4 patients with ocular myasthenia gravis with troublesome diplopia. All patients were in remission and had shown a consistently stable angle of deviation for at least 6 months preoperatively. The extent of eye muscle surgery was based on the degree of deviation in the primary position, and conventional recession and resection procedures were performed in 3 patients and hang-loose recession with an adjustable recession in 1. Single binocular vision was obtained in 3 patients in the primary position without prism correction or compensatory head posture. Electron-microscopic studies on the eye muscle specimens obtained at strabismus surgery revealed non-specific degenerative findings for the muscle fibers and sarcomeric disorganization compared to that in a control extraocular muscle.

Age-related changes in alpha-adrenoceptor-mediated blood pressure in the rat: relationship between the potency for phenylephrine and the maximum number of binding sites

To study the effects of aging on the blood pressure potency of phenylephrine, 6-, 10- and 40-week-old rats were used. In anesthetized rats, the potency (pD2 value) of phenylephrine on the blood pressure tended to increase with age from 6 to 10 weeks, but significantly decreased thereafter with age from 10 to 40 weeks. Similarly, in pithed rats, the potency of phenylephrine significantly increased, but decreased thereafter. In isolated rat thoracic aorta, the pD2 value of phenylephrine from the contractile responses significantly increased with age from 6 to 10 weeks, but decreased thereafter from 10 to 40 weeks. The change in the potency of phenylephrine on the blood pressure was proportional to the pD2 value of phenylephrine estimated in aortic preparations. The specific binding of [3H]prazosin to single smooth muscle cells of thoracic aorta from different aged rats was saturable. The maximum number of binding sites (Bmax) significantly increased with age from 6 to 10 weeks, but decreased thereafter from 10 to 40 weeks. However, the dissociation constant of [3H]prazosin (Kd) did not alter with age. The changes in the potencies (pD2 values) of phenylephrine on the pressure responses and on the contractile responses were proportional to the logarithm of the maximum number of binding sites. The present study suggests that age-related changes in blood pressure are due to changes in the maximum number of binding sites (receptor density) of alpha 1-adrenoceptors.

Clinical studies of ocular motility disturbances. Part 1. Ocular motility disturbances: causes and incidence

Between January 1985 and December 1994, 500 cases of ocular motility disturbances were encountered in our department; we analyzed these statistically. There were 48 cases of supranuclear palsy (10%), 281 of ocular motor nerve palsies (56%), 19 with myasthenia gravis (4%), 29 with myogenic palsy (6%), 57 with abnormal innervation (11%), and 63 instances of mechanical disturbances (13%). There were more men than women in all groups except myasthenia gravis. Eighty-four ocular motor nerve palsy and 15 blowout fracture patients recovered spontaneously. Spontaneous recovery occurred within 6 months in 80 (93%) patients with ocular motor nerve palsy. The abnormality detection rate, using diagnostic imaging, was high for supranuclear and myogenic palsy and the mechanical disturbance groups, but very low for the ocular motor nerve palsy groups. In 3 supranuclear palsy patients, small infarctions of the brainstem were discovered by magnetic resonance imaging (MRI) but were not found with computed tomography (CT). MRI thus proved useful in detecting abnormalities of brainstem lesions.

The reliability of a video-enhanced Hirschberg test under clinical conditions

PURPOSE

To examine the reliability and usefulness of a video-based Hirschberg test under clinical conditions.

METHODS

The authors estimated ocular deviation in 87 patients with strabismus through automated analysis of corneal reflex displacement using a video refractor. The reproducibility of measurement, the comparison with the prism and alternate cover test (PACT), and the distribution of the Hirschberg ratio were investigated.

RESULTS

The 95% limits of agreement of the video-based Hirschberg test evaluated by repeated measurements were +/- 0.18 mm (equivalent to +/- 2.2 degrees or +/- 3.8 prism diopters [PD] of calculated strabismic deviation) for the horizontal deviation and +/- 0.28 mm (equivalent to +/- 3.4 degrees or +/- 5.9 PD) for the vertical deviation. The 95% limits of agreement between the Hirschberg measures and the PACT were within +/- 7.8 degrees or +/- 13.7 PD. The average (+/- SD) Hirschberg ratio was 12.3 +/- 1.2 degrees/mm or 21.8 +/- 2.1 PD/mm.

CONCLUSIONS

The video-enhanced Hirschberg measurement shows good reproducibility and ease of application, even in the testing of infants. In quantitative analysis, however, systematic measurement error resulting from intersubject variance of the Hirschberg ratio should be taken into consideration.

The anti-emetic activity of GK-128 in Suncus murinus

In Suncus murinus, various emetic responses and the anti-emetic activity of a new 5-hydroxytryptamine3 (5-HT3) receptor antagonist, GK-128 (2-[(2-methylimidazol-1-yl) methyl benzo[f]thiochromen-1-one monohydrochloride hemihydrate), were investigated. Cancer chemotherapeutic agents, cisplatin and cyclophosphamide, dose-dependently induced emesis of long-lasting duration. The 5-HT3 receptor agonist, 2-methyl-5-HT, and copper sulfate also induced emesis of short duration. However, another 5-HT3 receptor agonist, m-chlorophenylbiguanide, was not consistently emetic. GK-128 inhibited the emetic responses induced by chemotherapeutic agents and 2-methyl-5-HT with similar potency. The anti-emetic action of GK-128 was more potent than that of ondansetron, Y-25130, granisetron and metoclopramide. The order of potency of these drugs, except granisetron, was consistent with that of their 5-HT3 receptor binding affinity in rat cortex. GK-128 failed to inhibit copper sulfate-induced emesis. These data suggest that GK-128 has a potent inhibitory effect on emesis via the 5-HT3 receptor, and that the 5-HT3 receptor involved in emesis in Suncus murinus may be different from the classically defined 5-HT3 receptor in other animals such as rats, dogs and ferrets.

The effect of the slope inclination of buccal polished surface of mandibular denture base on food retention

The accumulation of food debris in the buccal vestibule can inhibit normal mastication and appears to be a factor that can cause patient discomfort. This study focused on the effect of the slope inclination of the buccal polished surface of the mandibular denture base on the ability to expel test-food particles from the buccal vestibule. It was revealed that an inclination of the slope steeper than 80 degrees markedly inhibits the normal ability to expel foods from the vestibule. It was revealed that the most appropriate inclination of the buccal slope is approximately 60 degrees or 70 degrees. These results could be utilized for constructing a denture prosthesis.

Extraocular muscle surgery in a rabbit model: site of reattachment following hang-back and conventional recession

To determine the precise site of reattachment of recessed muscles, 4-mm conventional and hang-back recessions of the inferior rectus muscle were performed in 18 albino rabbits. Six weeks later, the distance from the anterior border of the reattached muscle to the insertion was measured both grossly and microscopically. In all cases the operated muscles had advanced minimally from the site of surgical placement. Gross observation showed that the mean forward creep was significantly greater for those rabbits which underwent hang-back recession (1.81 +/- 0.67 mm) than for those that were submitted to the conventional technique (0.83 +/- 0.38 mm). Measurements done on histological sections revealed that the mean distance of the anterior border of the muscle fiber from the reference suture was larger for conventional recession (2.73 +/- 0.75 mm) than for hang-back recession (1.91 +/- 0.72 mm).

Critical period for restoration of normal stereoacuity in acute-onset comitant esotropia

We conducted a retrospective study of 25 patients with acute-onset comitant esotropia to evaluate whether the timing of the start of treatment is a critical factor in the development of normal stereopsis. The mean age at onset was 12 years 4 months, and mean age at the start of treatment was 17 years 9 months. Bifixation was defined as a stereoacuity threshold score that was numerically lower than 60 seconds of arc on stereotesting. An operation was performed on the nonfixating eye for the prism-adapted angle. At the final examination, bifixation was observed in four patients (16%) with the Randot test and in 15 patients (60%) with the Titmus test. No relationship was found between the time of the start of treatment and the postoperative development of stereopsis, nor was there a significant (P > .10) difference between the two groups with early and delayed start of treatment in the proportion of patients with bifixation.

Intraoperative adjustable suture surgery for bilateral superior oblique palsy

BACKGROUND

The modified Harada-Ito procedure has been reported to be an effective treatment for correction of cyclotorsion in bilateral superior oblique palsy. However, there are no reports regarding its use in intraoperative adjustable suture surgery.

METHODS

The authors performed a retrospective study of 12 patients with traumatic bilateral superior oblique palsy who were classified as having either symmetric or asymmetric palsy according to the symmetry of the alternate hyperdeviation on side gazes. Cyclotorsion and vertical and horizontal deviation in the nine diagnostic positions were measured preoperatively and postoperatively.

RESULTS

Of the 12 patients, 6 were determined to have symmetric palsy and 6 asymmetric palsy. Intraoperative adjustable suture surgery with the modified Harada-Ito procedure was performed bilaterally in the six patients with symmetric palsy and unilaterally in those with asymmetric palsy. The median measured value of extorsion in the primary position was reduced from 14.5 degrees to 2.5 degrees in patients with symmetric palsy and from 9.5 degrees to 2.0 degrees in those with asymmetric palsy. In downgaze, some degree of residual extorsion remained, and there was no significant change in esodeviation after surgery. In five patients with symmetric palsy and in all of those with asymmetric palsy, normal single binocular vision in the primary position but did not that in downgaze was restored after surgery.

CONCLUSION

Intraoperative adjustable suture surgery is an effective treatment in correcting torsion, but may not be as effective for esodeviation in downgaze.

Advancement of medial rectus muscle to the original insertion for consecutive exotropia

Twenty-four patients who underwent surgery to correct consecutive exotropia that developed iatrogenically after surgical overcorrection were studied retrospectively. All patients underwent single or bilateral advancement of the medial rectus muscle to the original muscle insertion. The mean preoperative exodeviation was 26.7 prism diopters at distance and 35.2 delta at near. Postoperatively, in cases receiving advancement of a single medial rectus, the mean amount of correction was 23.2 delta at distance and 29.6 delta at near. In cases receiving bilateral medial rectus advancement, the mean amount of postoperative correction was 26.3 delta at distance and 39.8 delta at near. Adduction deficiency was normalized in five patients (71%), while convergence insufficiency was improved in only nine patients (45%) after surgery. Twelve (50%) patients had binocular single vision at distance on a normal or abnormal basis as determined by the Bagolini lens test.

Preoperative prism correction in patients with acquired esotropia

We performed a prospective study of preoperative prism adaptation in 77 patients with acquired esotropia. Sixty-three of them increased their angle of squint when wearing Fresnel press-on prisms for 5-7 days. After the angle had stabilized to a point that did not exceed the press-on prisms by more than 10 prism D, they were randomly divided into two groups. Thirty-two patients underwent surgery based on the prism-adapted angle. The other 31 patients underwent surgery based on their initially measured angle. Fourteen patients who did not respond to prism correction underwent surgery based on the angle before prism correction. Success rates with deviations between 0 and 10 prism diopters measured 1 year after surgery were highest in those in whom surgery was based on the prism-determined angle and were lowest in the nonresponders, who had no fusion response to the prisms.

Intraoperative suspension-recession technique for treatment of vertical strabismus in thyroid myopathy

Ten patients underwent extraocular muscle surgery with an intraoperative suspension-recession technique for diplopia induced by vertical strabismus in thyroid myopathy. The average ratio of the reduction of vertical deviation to the amount of surgery was 1.8 degrees/mm (range, 1.0 degrees/mm-2.8 degrees/mm). Eight (80%) patients had single binocular vision restored in the primary position without prism or compensatory torticollis after surgery. One patient who showed evidence of abnormal thyroid function at surgery developed an overcorrection postoperatively.

[Vertebral artery occlusion therapy for a VA-PICA giant aneurysm: hemodynamic analysis by hydraulic vascular model]

Although therapeutic occlusion of the vertebral artery has been an accepted treatment for an inaccessible VA giant aneurysm, several problems have been reported such as incomplete thrombosis, growth or rupture of the aneurysms, and cerebral embolism originating from the aneurysmal cavity. Hemodynamic changes after occlusion therapy are suspected to be responsible for these phenomena. It is usually difficult to solve these problems or to predict them before operation because multiple factors are related in a complex fashion in a living body. One of the effective means is to simulate these hemodynamic conditions by a hydraulic vascular model. To evaluate hemodynamics after gradual therapeutic occlusion of the vertebral artery, a glass sphere of 2.5 cm in diameter was placed in a hydraulic model and regarded as a VA-PICA aneurysm. 40% glycerol solution at 25 degrees C, having similar viscosity and specific gravity to human whole blood at 37 degrees C, was used as a perfusate in this study. The dye was injected into the aneurysm and intensity change of the transmitted light was measured. Half-life of the dye was calculated from the thus-obtained clearance curve and was regarded as an index of intra-aneurysm stagnation. The flow volumes of each arterial site have been estimated in our previous study: 60 ml/min to the territory of one posterior cerebral artery, and 80 ml/min to the cerebellum and the brain stem. Clearance curves were recorded in the following various conditions. The flow value of the PICA was set to be 5, 10, 15, 20, 25, and 30 ml/min.(ABSTRACT TRUNCATED AT 250 WORDS)

Photoreceptor outer segments in the aqueous humor of patients with atopic dermatitis and retinal detachment

We examined the aqueous humor by electron microscopy of four patients with atopic dermatitis and retinal detachment. All the patients had a moderate number of cells in the aqueous humor. Cataract impaired fundus visualization except for one patient with aphakia. A flat retinal detachment involved a wide area detected by echography. The intraocular pressure in the eyes with retinal detachment demonstrated a marked diurnal fluctuation compared with that of the fellow eye. The aqueous cells consisted predominantly of photoreceptor outer segments. This finding does not support the theory that aqueous cells in atopic dermatitis are of inflammatory origin. Photoreceptor outer segments in aqueous humor are indicative of rhegmatogenous retinal detachment in patients with atopic dermatitis.

[Basilar artery occlusion therapy for giant aneurysm: hemodynamic analysis by hydraulic vascular model]

Therapeutic occlusion of the basilar artery has been one of the alternative treatments for surgically or intravascularly inaccessible basilar bifurcation giant aneurysms. However, several problems have been reported, such as incomplete thrombosis of the aneurysms, their growth or rupture, and cerebral embolism originating from their cavities. Since hemodynamic changes after occlusion therapy are suspected to be responsible for these phenomena, they were investigated by a hydraulic vascular model. A hydraulic vascular model of the vertebrobasilar artery was constructed with silicone and glass tubes. A glass-made sphere of 2.5 cm in diameter was attached to the model and was regarded as a basilar head aneurysm. A 40% glycerol solution at 25 degrees C was found to be of similar viscosity and specific gravity to those of human whole blood at 37 degrees C and was perfused in the model. A device to measure intra-aneurysmal clearance was made from a stable luminous source and a Cds photocell. Good correlation was found between the output and an intra-aneurysmal dye concentration. The dye was injected into the aneurysm and its half-life was calculated from clearance curves. It was then regarded as an index of stagnation in an aneurysmal cavity. The flow volumes were estimated as: 60ml/min to the territory of one posterior cerebral artery (PCA) and 80ml/min to the cerebellum and the brain stem. Half-life was recorded in the following conditions: 120ml/min of flow in the basilar artery (BA) into bilateral PCAs stimulating the condition before BA occlusion, and various flow values (60ml/min to 10ml/min) of P1 segment simulating the conditions after BA occlusion distal to the superior cerebellar artery.(ABSTRACT TRUNCATED AT 250 WORDS)

Involvement of Ca2+ entry and inositol trisphosphate-induced internal Ca2+ mobilization in muscarinic receptor-mediated catecholamine release in dog adrenal chromaffin cells

Catecholamine (CA) release from adrenal medulla evoked by muscarinic receptor stimulation has been studied using isolated perfused adrenal gland and cultured chromaffin cells from dogs. Muscarine and oxotremorine (1-100 microM), and bethanechol (0.1-1 mM) dose-dependently stimulated CA release. Muscarine-evoked CA release was antagonized with M1-antagonist, pirenzepine and, to a lesser extent, with atropine; and was reduced either by removal of extracellular Ca2+ or treatment with Ca2+ channel blockers. Muscarine caused an increase of 45Ca uptake and 22Na uptake. Tetrodotoxin (TTX) did not affect muscarine-evoked increase of 22Na uptake and CA release. Under the absence of extracellular Ca2+, muscarine stimulated a 45Ca efflux. Muscarine-induced CA release was attenuated by treating the cells with 8-(N,N-diethylamino)-octyl-3,4,5-trimethoxybenzoate-HCl (TMB-8) which blocks Ca2+ release from the intracellular store. A phospholipase C inhibitor, neomycin, markedly reduced muscarine-induced CA release but not nicotine- and high K(+)-evoked release. Cinnarizine, a Ca2+ channel blocker, attenuated muscarine-evoked but not caffeine-induced CA release and 45Ca efflux in the absence of extracellular Ca2+. Muscarine caused an increase in intracellular free Ca2+ concentration ([Ca2+]i) in the presence of extracellular Ca2+. It caused a similar increase, but to a lesser extent, in the absence of extracellular Ca2+. The increase of [Ca2+]i induced by muscarine without extracellular Ca2+ was reduced by neomycin and cinnarizine. Polymixin B and retinal, which reduced 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced CA release, had little effect on muscarine-induced CA release. Muscarine increased cellular Ins(1,4,5)P3 production, and atropine inhibited this increase.(ABSTRACT TRUNCATED AT 250 WORDS)

[Motor adaptation in the Bielschowsky head-tilt test in cases of superior oblique palsy]

To elucidate a motor adaptation phenomenon in the Bielschowsky head-tilt test in cases of superior oblique palsy, a gain of the otolith-ocular reflex was studied. The amplitude of ocular counter-rolling (OCR) of the non-paretic eye was measured with a photographic method, using limbal conjunctival marks as landmarks which were marked with indigo carmine. The average preoperative OCR of the non-paretic eye was 10.49 degrees at 30 degrees of head tilt to both sides, but after corrective surgery in the paretic eye the OCR of the non-paretic eye decreased to 8.43 degrees. To clarify the relation between OCR, duration of palsy and vertical deviation of the Bielschowsky head-tilt test (BHP), which was the difference of vertical deviation measured with the head tilted to the left and right shoulders at an angle of 30 degrees, the BHP/OCR ratio was calculated. We found no relation between BHP and OCR, but the BHP/OCR ratio increased proportionally in cases of long-standing palsy, From these results an increased BHP/OCR ratio could be an adaptive phenomenon caused by secondary innervational changes or muscle contracture to minimizing the contralateral head tilt to maintain binocular single vision.