Minimally invasive strabismus surgery (MISS) for inferior obliquus recession

PURPOSE: To present a novel, minimally invasive strabismus surgery (MISS) technique for inferior obliquus recessions. METHODS: Graded MISS inferior obliquus recessions were performed in 20 eyes of 15 patients by applying two small conjunctival cuts, one at the insertion of inferior obliquus and another where the scleral anchoring of the muscle occurred. RESULTS: The amount of recession was 12.2 +/- 2.3 mm (range 6 to 14 mm). The vertical deviation, which was measured in 25 degrees of adduction, decreased from preoperatively 12.8 degrees +/- 5.6 degrees to 2.7 degrees +/- 2.2 degrees (p < 0.0001) at 6 months. LogMAR visual acuity was preoperatively -0.10 +/- 0.17 and at 6 months -0.14 +/- 0.22 (p > 0.1). In one eye (2.5%) the two cuts had to be joined because of excessive bleeding. Binocular vision improved in eight patients, remained unchanged in six patients, and decreased from 30 to 60 arcsec in one patient (p > 0.1). Conjunctival and lid swelling were hardly visible on the first postoperative day in primary gaze position in 10/20 (50%) of eyes. Five of the eyes (25%) had mild and five (25%) moderate visibility of surgery. One patient out of 15 (7%) needed repeat surgery because of insufficient reduction of the sursoadduction within the first 6 months. The dose-effect relationship 6 months postoperatively for an accommodative near target at 25 degrees adduction was 0.83 degrees +/- 0.43 degrees per mm of recession. CONCLUSIONS: This study demonstrates that small-incision, minimal dissection inferior obliquus graded recessions are feasible and effective to improve ocular alignment in patients with strabismus sursoadductorius.

Minimally invasive strabismus surgery for rectus muscle posterior fixation

AIMS: To present a novel, minimally invasive strabismus surgery (MISS) technique for rectus muscle posterior fixation. METHODS: This study reports the results of 32 consecutive MISS rectus muscle posterior fixation surgeries performed on 19 patients by applying only two small L-shaped openings where the two retroequatorial scleromuscular sutures were placed. RESULTS: On the first postoperative day, in primary position, redness was hardly visible in 16 eyes (50%) and only moderate redness was visible in 6 eyes (19%). No serious complication occurred. Preoperative visual acuity and refraction remained unchanged at 6 months (p > 0.1). The preoperative convergence excess (n = 13) decreased from 10.3 +/- 4.1 to 5.2 +/- 4.0 degrees at 6 months (p < 0.005). In all patients operated on for gaze incomitance (n = 6) improvement was achieved at 6 months. CONCLUSIONS: This study shows that keyhole minimal-dissection rectus muscle posterior fixation surgery is feasible and effective to improve ocular alignment. The MISS technique seems to be superior in the direct postoperative period since only minimal conjunctival swelling and no corneal complications were observed.

Minimally invasive strabismus surgery for horizontal rectus muscle reoperations

AIMS: To study if minimally invasive strabismus surgery (MISS) is suitable for rectus muscle reoperations. METHODS: The study presents a series of consecutive patients operated on by the same surgeon at Kantonsspital St Gallen, Switzerland with a novel MISS rectus muscle reoperation technique. Surgery is done by applying two small radial cuts along the muscle insertion. Through the tunnel obtained after muscle separation from surrounding tissue, a recession, advancement or plication is performed. RESULTS: In 62 eyes of 51 patients (age 35.4 (SD 16.3) years) a total of 86 horizontal rectus muscles were reoperated. On the average, the patients had 2.1 strabismus surgeries previously. Preoperative logMAR visual acuity was 0.38 (0.82) compared with 0.37 (0.83) at 6 months (p>0.1). On the first postoperative day, in the primary gaze position conjunctival and lid swelling and redness was hardly visible in 11 eyes, discrete in 15 eyes, moderate in 11 eyes and severe in 15 eyes. One corneal dellen and one corneal erosion occurred, which both quickly resolved. The preoperative deviation at distance for esodeviations (n = 15) of 12.5 (8.5) degrees decreased to 2.6 (7.8) degrees at 6 months (p<0.001). For near, a decrease from 12.0 (10.1) degrees to 2.9 (1.6) degrees was observed (p<0.001). The preoperative deviation at distance for exodeviations (n = 35) of -16.4 (8.5) degrees decreased to -7.9 (6.5) degrees at 6 months (p<0.005). For near, a decrease from -16.5 (11.4) degrees to -2.9 (1.5) degrees was observed (p<0.005). Within the first 6 months, only one patient had a reoperation. At month 6, in four patients a reoperation was planned or suggested by us because of unsatisfactory alignment. No patient experienced persistent diplopia or necessitated a reoperation because of double vision. Stereovision improved at month 6 compared with preoperatively (p<0.01). CONCLUSIONS: The study demonstrates that a small-cut, minimal dissection technique allows to perform rectus muscle reoperations. The MISS technique seems to reduce conjunctival and lid swelling in the direct postoperative period.

Comparison of a new, minimally invasive strabismus surgery technique with the usual limbal approach for rectus muscle recession and plication

AIM: To present a novel, minimally invasive strabismus surgery (MISS) technique for rectus muscle operations. METHODS: In this prospective study with a non-concurrent, retrospective comparison group, the first 20 consecutive patients treated with MISS were matched by age, diagnosis and muscles operated on, with 20 patients with a limbal opening operated on by the same surgeon at Kantonsspital, St Gallen, Switzerland. A total of 39 muscles were operated on. MISS is performed by applying two small radial cuts along the superior and inferior muscle margin. After muscle separation from surrounding tissue, a recession or plication is performed through the resulting tunnel. Alignment, binocular single vision, variations in vision, refraction, and number and types of complications during the first 6 postoperative months were registered. RESULTS: Visual acuity decreased at postoperative day 1 in both groups. The decrease was less pronounced in the group operated on with MISS (difference of decrease 0.14 logMAR, p<0.001). An abnormal lid swelling at day 1 was more frequent in the control group (21%, 95% confidence interval (CI) 9% to 41%, 5/24 v 0%, 95% CI 0 to 13%, 0/25, p<0.05). No significant difference was found for final alignment, binocular single vision, other visual acuities, refractive changes or complications (allergic reactions, dellen formation, abnormal conjuctival findings). A conversion to a limbal opening was necessary in 5% (95% CI 2% to 17%, 2/39) of muscles. CONCLUSIONS: This study shows that this new, small-incision, minimal dissection technique is feasible. The MISS technique seems to be superior in the direct postoperative period as better visual acuities and less lid swelling were observed. Long-term results did not differ in the two groups.

Radiation metabolomics. 1. Identification of minimally invasive urine biomarkers for gamma-radiation exposure in mice

Gamma-radiation exposure has both short- and long-term adverse health effects. The threat of modern terrorism places human populations at risk for radiological exposures, yet current medical countermeasures to radiation exposure are limited. Here we describe metabolomics for gamma-radiation biodosimetry in a mouse model. Mice were gamma-irradiated at doses of 0, 3 and 8 Gy (2.57 Gy/min), and urine samples collected over the first 24 h after exposure were analyzed by ultra-performance liquid chromatography-time-of-flight mass spectrometry (UPLC-TOFMS). Multivariate data were analyzed by orthogonal partial least squares (OPLS). Both 3- and 8-Gy exposures yielded distinct urine metabolomic phenotypes. The top 22 ions for 3 and 8 Gy were analyzed further, including tandem mass spectrometric comparison with authentic standards, revealing that N-hexanoylglycine and beta-thymidine are urinary biomarkers of exposure to 3 and 8 Gy, 3-hydroxy-2-methylbenzoic acid 3-O-sulfate is elevated in urine of mice exposed to 3 but not 8 Gy, and taurine is elevated after 8 but not 3 Gy. Gene Expression Dynamics Inspector (GEDI) self-organizing maps showed clear dose-response relationships for subsets of the urine metabolome. This approach is useful for identifying mice exposed to gamma radiation and for developing metabolomic strategies for noninvasive radiation biodosimetry in humans.

Acute lower gastrointestinal hemorrhage: minimally invasive management with microcatheter embolization

PURPOSE: To evaluate the efficacy of superselective embolization therapy in the management of acute lower gastrointestinal (LGI) hemorrhage, including any bleeding distal to the ligament of Treitz. MATERIALS AND METHODS: Between June and August 2007, 20 patients with acute LGI bleeding underwent superselective transcatheter arterial embolization (TAE) at the authors' institution. The bleeding had different causes. All patients were treated with use of microcatheters. The following embolic agents were used: microcoils (n = 16), polyvinyl alcohol (PVA) particles (n = 2), and a combination of microcoils and PVA particles (n = 2). Outcome measures included technical success (complete cessation of bleeding as documented at completion angiography), clinical success (resolution of signs or symptoms of LGI bleeding within 30 days after TAE), and the rate of major and minor complications. RESULTS: The identified bleeding sources were as follows: jejunal branch, branch of middle colic artery, branch of ileocolic artery, ileal branch, branch of left colic artery, branch of sigmoid artery, branch of the superior rectal artery, and branch of the middle rectal artery. Technical success with effective control of active bleeding was achieved in all patients (100%). Clinical success attributed to TAE was documented in 18 of the 20 patients (90%). Major complications included death due to pulmonary embolism, heart infarction, and multiorgan failure in the 3rd week after TAE; a procedure-related colonic infarction occurred in one patient. A minor complication occurred in one patient who developed a groin hematoma. CONCLUSIONS: Superselective embolization may be used for effective, minimally invasive control of acute LGI bleeding.

The Role of Science in Controlling Invasive Species: A Case Study on Wild Pigs

Presentation by Dr. Stephen Ditchkoff.

Are Native and Non-native Populations of an Invasive Plant Really Different?

This presentation provides an overview of his transcontinental research on giant goldenrod an invasive plant species in Europe that originates from North America. He investigated the effects of reintroduction on the plant’s performance, the plant’s effect on species richness and the relationship between the plant’s competitive effects and its ecotypic variation.

Selection of preadapted populations allowed Senecio inaequidens to invade Central Europe

Invasive species often evolve rapidly in response to the novel biotic and abiotic conditions in their introduced range. Such adaptive evolutionary changes might play an important role in the success of some invasive species. Here, we investigated whether introduced European populations of the South African ragwort Senecio inaequidens (Asteraceae) have genetically diverged from native populations. We carried out a greenhouse experiment where 12 South African and 11 European populations were for several months grown at two levels of nutrient availability, as well as in the presence or absence of a generalist insect herbivore. We found that, in contrast to a current hypothesis, plants from introduced populations had a significantly lower reproductive output, but higher allocation to root biomass, and they were more tolerant to insect herbivory. Moreover, introduced populations were less genetically variable, but displayed greater plasticity in response to fertilization. Finally, introduced populations were phenotypically most similar to a subset of native populations from mountainous regions in southern Africa. Taking into account the species' likely history of introduction, our data support the idea that the invasion success of Senecio inaequidens in Central Europe is based on selective introduction of specific preadapted and plastic genotypes rather than on adaptive evolution in the introduced range.

Novel weapons: Invasive plant suppresses fungal mutualists in America but not in its native Europe

Why some invasive plant species transmogrify from weak competitors at home to strong competitors abroad remains one of the most elusive questions in ecology. Some evidence suggests that disproportionately high densities of some invaders are due to the release of biochemicals that are novel, and therefore harmful, to naive organisms in their new range. So far, such evidence has been restricted to the direct phytotoxic effects of plants on other plants. Here we found that one of North America's most aggressive invaders of undisturbed forest understories, Alliaria petiolata (garlic mustard) and a plant that inhibits mycorrhizal fungal mutualists of North American native plants, has far stronger inhibitory effects on mycorrhizas in invaded North American soils than on mycorrhizas in European soils where A. petiolata is native. This antifungal effect appears to be due to specific flavonoid fractions in A. petiolata extracts. Furthermore, we found that suppression of North American mycorrhizal fungi by A. petiolata corresponds with severe inhibition of North American plant species that rely on these fungi, whereas congeneric European plants are weakly affected. These results indicate that phytochemicals, benign to resistant mycorrhizal symbionts in the home range, may be lethal to naive native mutualists in the introduced range and indirectly suppress the plants that rely on them.

Adaptive rather than non-adaptive evolution of Mimulus guttatus in its invasive range

Adaptive and non-adaptive evolutionary processes are likely to play important roles in biological invasions but their relative importance has hardly ever been quantified. Moreover, although genetic differences between populations in their native versus invasive ranges may simply reflect different positions along a genetic latitudinal cline, this has rarely been controlled for. To study non-adaptive evolutionary processes in invasion of Mimulus guttatus, we used allozyme analyses on offspring of seven native populations from western North America, and three and four invasive populations from Scotland and New Zealand, respectively. To study quantitative genetic differentiation, we grew 2474 plants representing 17 native populations and the seven invasive populations in a common greenhouse environment under temporarily and permanently wet soil conditions. The absence of allozyme differentiation between the invasive and native range indicates that multiple genotypes had been introduced to Scotland and New Zealand, and suggests that founder effects and genetic drift played small, if any, roles in shaping genetic structure of invasive M. guttatus populations. Plants from the invasive and native range did not differ in phenology, floral traits and sexual and vegetative reproduction, and also not in plastic responses to the watering treatments. However, plants from the invasive range produced twice as many flower-bearing upright side branches than the ones from the native populations. Further, with increasing latitude of collection, vegetative reproduction of our experimental plants increased while sexual reproduction decreased. Plants from the invasive and native range shared these latitudinal clines. Because allozymes showed that the relatedness between native and invasive populations did not depend on latitude, this suggests that plants in the invasive regions have adapted to the local latitude. Overall, our study indicates that quantitative genetic variation of M. guttatus in its two invasive regions is shaped by adaptive evolutionary processes rather than by non-adaptive ones. (C) 2007 Gesellschaft fur Okologie. Published by Elsevier GmbH. All rights reserved.

Human and feline invasive cervical resorptions: the missing link?--Presentation of four cases

This report describes 4 patients presenting with multiple teeth affected by invasive cervical resorption (ICR). The cases came to our attention between 2006 and 2008; previously, no cases of multiple ICR (mICR) had been reported in Switzerland. Characteristics common to all 4 cases included progression of disease over time, similar clinical and radiographic appearance of lesions, and obscure etiology. The histologically assessed teeth showed a similar pattern of tooth destruction, with resorptive lesions being confined to the cervical region. Howship's lacunae and multinucleated, tartrate-resistant acid phosphatase-positive odontoclasts were detected. None of the teeth presented with internal resorption. The positive pulp sensitivity corresponded to the histologic findings, indicating that the pulp tissue resisted degradation even in advanced stages of resorptive lesions. Although mICR is rare in humans, a similar disease known as feline odontoclastic resorptive lesions (FORL) is common in domestic, captive, and wild cats. The etiology of FORL, like that of mICR, remains largely unknown. Because FORL has been associated with feline viruses, we asked our mICR patients whether they had had contact with cats, and interestingly, all patients reported having had direct (2 cases) or indirect (2 cases) contact. In addition, blood samples were taken from all patients for neutralization testing of feline herpes virus type 1 (FeHV-1). Indeed, the sera obtained were able to neutralize (2 cases) or partly inhibit (2 cases) replication of FeHV-1, indicating transmission of feline viruses to humans. Future studies on mICR (and FORL) should evaluate the possible role of a (feline) virus as an etiologic (co-)factor in this disease.

Major surface glycoproteins of insect forms of Trypanosoma brucei are not essential for cyclical transmission by tsetse

Procyclic forms of Trypanosoma brucei reside in the midgut of tsetse flies where they are covered by several million copies of glycosylphosphatidylinositol-anchored proteins known as procyclins. It has been proposed that procyclins protect parasites against proteases and/or participate in tropism, directing them from the midgut to the salivary glands. There are four different procyclin genes, each subject to elaborate levels of regulation. To determine if procyclins are essential for survival and transmission of T. brucei, all four genes were deleted and parasite fitness was compared in vitro and in vivo. When co-cultured in vitro, the null mutant and wild type trypanosomes (tagged with cyan fluorescent protein) maintained a near-constant equilibrium. In contrast, when flies were infected with the same mixture, the null mutant was rapidly overgrown in the midgut, reflecting a reduction in fitness in vivo. Although the null mutant is patently defective in competition with procyclin-positive parasites, on its own it can complete the life cycle and generate infectious metacyclic forms. The procyclic form of T. brucei thus differs strikingly from the bloodstream form, which does not tolerate any perturbation of its variant surface glycoprotein coat, and from other parasites such as Plasmodium berghei, which requires the circumsporozoite protein for successful transmission to a new host.