bluuebunny/crossref_metadata_2025 huggingface dataset:
Highly symptomatic adult polycystic liver disease: options and results of surgical management
Authors: Tan Yu Meng , Ooi London Lucien
Published: August 2004

Background:  The majority of patients afflicted with adult polycystic liver disease (APLD) are asymptomatic. For those who are symptomatic, there are a variety of treatment procedures that have been proposed but these lack verification through long‐term studies with respect to safety and long‐term effectiveness. Choice of surgical procedure is related to the severity of APLD and morphology of the cysts within the liver. The aim of the present study was to analyse the immediate and long‐term results of fenestration and combined resection−fenestration at Singapore General Hospital.

Methods:  A retrospective analysis of clinical, operative, imaging and follow‐up data was carried out for 12 patients (10 women and two men) with symptomatic APLD who underwent surgery from January 1992 to December 2000. The primary outcome measures assessed were postoperative alleviation of symptoms, performance status, complications, mortality and long‐term recurrence of symptoms.

Results:  Nine patients underwent 12 fenestration procedures and three patients had combined resection−fenestration. Fenestration was carried out for eight of nine patients with a dominant cyst morphology and combination resection−fenestration was carried out for those three patients with diffuse cyst morphology. There was no operative mortality and all patients were discharged from hospital free of their preoperative symptoms. Overall morbidity rate was 58%. The mean follow up for the present cohort was 29.3 months. Only two patients had recurrence of symptoms. One patient with dominant cyst morphology who underwent laparoscopic fenestration had recurrence at 26 and 43 months but this was successfully treated finally with open fenestration. The other patient had diffuse cyst morphology and was treated with fenestration for recurrent cyst infection that recurred 1 month postoperatively. This required subsequent intravenous antibiotics and percutaneous drainage for resolution of symptoms.

Conclusion:  Treatment for symptomatic APLD should be based on the morphology of the liver cysts. Fenestration is a safe and acceptable procedure for patients with a dominant cyst pattern where liver size can be reduced after the cysts collapse. A combination of resection−fenestration is suitable for those with a diffuse cyst pattern where grossly affected segments are resected in combination with fenestration to allow for reduction in liver size.
Magnetic resonance imaging of the common bile duct to exclude choledocholithiasis
Authors: Kejriwal Ritwik , Liang Jennifer , Anderson Graeme , Hill Andrew
Published: August 2004

Background:  Prior to cholecystectomy it is important to assess the common duct for choledocholithiasis. Given that a proportion of common duct stones will pass without incident and that methods of removal of these stones are potentially morbid, it would be very useful to have a test that identified only those stones that need intervention. The present study was designed to assess whether a negative magnetic resonance cholangiopancreaticogram (MRCP) is able to reliably exclude clinically relevant common duct stones.

Methods:  A retrospective analysis on all patients with cholelithiasis, who underwent MRCP, between November 2001 and May 2003, for suspected choledocholithiasis, was performed. Patients were considered to have no clinically relevant choledocholithiasis if they had a negative MRCP for choledocholithiasis, and were not readmitted to the hospital with complications of choledocholithiasis within a minimum of 3 months after treatment for their cholelithiasis.

Results:  The MRCP was negative for choledocholithiasis in 74% of patients (60/81). The MRCP missed clinically relevant choledocholithiasis in only two patients, and had a positive predictive value of 0.95 and a negative predictive value of 0.97 for choledocholithiasis.

Conclusion:  In patients with strong indications for choledocholithiasis MRCP is able to reliably exclude clinically relevant choledocholithiasis and is therefore recommended as the preoperative diagnostic imaging tool of choice.
Management of postoperative urinary retention: a randomized trial of in−out versus overnight catheterization
Authors: Lau Hung , Lam Becky
Published: August 2004

Background:  There has been no consensus on the best catheterization strategy for the management of postoperative urinary retention. A prospective randomized trial was undertaken to establish the best practice guidelines for the management of postoperative urinary retention. The authors also evaluated the contemporary incidence of urinary retention following different categories of general surgery and examined risk factors associated with its occurrence.

Methods:  All patients who underwent elective inpatient surgery between January 2002 and June 2003 were recruited into the study. Patients who developed postoperative urinary retention were randomized to either having in−out catheterization or placement of an indwelling catheter for 24 h after surgery.

Results:  A total of 1448 patients was recruited. The overall incidence of urinary retention was 4.1% (n = 60). Significant risk factors associated with postoperative urinary retention included old age, anorectal procedures and use of spinal anaesthesia. Comparison of re‐catheterization and urinary tract infection rates between patients who were treated with in−out versus overnight catheterization found no significant differences.

Conclusions:  Postoperative urinary retention should be managed by in−out catheterization. Indwelling catheterization for 24 h appeared to bestow no additional benefits. The incidence of urinary retention increases with age, anorectal procedures and the use of spinal anaesthesia.
Blood loss and transfusion in elective abdominal aortic aneurysm surgery
Authors: Ho Pei , Ting Albert C. W. , Cheng Stephen W. K.
Published: August 2004

Background:  Intraoperative blood loss and transfusion are known determinants of mortality and morbidity of elective abdominal aortic aneurysm (AAA) repair. The present study analysed the pattern of blood loss and transfusion and evaluated the risk factors of blood loss during open repair of infrarenal AAA.

Methods:  Blood loss, transfusion and fluid replacement during elective open repair operation for patients with infrarenal AAA were correlated to demographic data, operative findings and procedural information.

Results:  A total of 129 patients with a mean age of 71 years was analysed. The mean blood loss was 1000 ± 887 mL (200−6000 mL). Blood transfusion, with a mean transfusion volume of 400 ± 591 mL (0−3000 mL), was required in 46% of patients. Univariate analysis showed that bodyweight, renal impairment, low haemoglobin and platelet counts, iliac artery involvement, large aneurysm, bifurcated graft, large graft diameter, prolonged aortic clamp time and long operation time were associated with a higher blood loss. A haemoglobin level of <10.5 g/dL (relative risk (RR): 4.6), platelet count <130 × 109/L (RR: 3.9), aortic clamp time >50 min (RR: 15), total operation time >200 min (RR: 11) and type of graft (RR: 3.5) were identified as independent determinants of blood loss on multivariate analysis.

Conclusion:  Intraoperative blood loss in elective infrarenal aneurysm surgery is influenced by patients’ haematological parameters, distal involvement of aneurysm and degree of difficulty of operation.
Sutureless intestinal plication
Authors: Wong Shing Wai , King Denis
Published: August 2004

Background:  Adhesions form between damaged mesothelial surfaces and can cause recurrent small bowel obstruction. Repeat laparotomies may be required in some cases, which can be associated with significant morbidities.

Methods:  A technique is described for plication of the small bowel in an orderly manner with the use of two silicone indwelling urinary catheters.

Conclusions:  This plication technique, a modification of the Noble and Childs–Phillips operations, is effective, safe, quick and cost‐effective.
Refinements in the lotus petal flap repair of the vulvo‐perineum
Authors: Warrier Satish K. , Kimble Frank W. , Blomfield Penelope
Published: August 2004

Background:  Many reconstructive techniques have been used to repair the vulval, vaginal and perianal areas after excision. These range from grafts to various types of flap repair. The authors have modified a procedure called the lotus petal flap repair to provide a simpler, equally reliable, yet aesthetically enhanced technique for vulvo‐perineal reconstruction.

Methods:  Where primary closure was not possible the modified lotus petal flap was employed. The present flap design was based on the dense perforators supplying the perineum. The flap resembles the petals of a lotus flower as in the design of Yii and Niranjan. However, the present modification uses a thinned cutaneous flap without identification of the blood supply. The flap is sited over an area of dense perforators. Transpostion with this thinner design allows for easy coverage of the defects.

Results:  In the present series of eight patients and 12 flaps no cases of partial or complete flap failure were recorded. The only complications encountered in the series were one case of cellulitis after discharge from hospital, and a single case of urethral incontinence.

Conclusions:  The modified lotus flap repair is a reliable, simple, and aesthetically appealing alternative to those already available to the plastic surgeon for vulval repair.
Use of a disposable tunneller for arterial bypass to the foot
Authors: Beiles C. Barry
Published: August 2004

Background:  Performance of pedal artery bypass for limb salvage is well described. A tunneller is required to place the vein graft subcutaneously, but a suitable instrument to achieve this is not always available.

Methods:  A disposable catheter passer used for ventriculo‐peritoneal shunts is ideally suited to this purpose, and the technique of its use is described.

Conclusions:  Placement of the vein graft in a subcutaneous tunnel with minimal trauma is easily achieved using this instrument.
Inexpensive home‐made laparoscopic trainer and camera
Authors: Pokorny Morgan R. , McLaren Scott L.
Published: August 2004

Laparoscopic surgery is a well‐established and important component of modern surgical practice across a range of surgical specialties. However, training in this modality is hampered by the nature of the equipment and its cost, and the difficulty of much of the surgery undertaken. Hence it can take some time for advanced and especially basic trainees to attain competency in laparoscopic techniques, and it remains difficult to practise or refine techniques. A solution to one half of this problem has been investigated by designing an inexpensive home‐made laparoscopic camera and trainer system that can be assembled and used by one or more trainees either in a skills lab or at home. The components are readily available and the present system comprises a CMOS spy camera mounted on a rigid plastic tube that is used within a translucent plastic training box, obviating the need for an inbuilt light source. The costs were successfully constrained to under NZ$200.
G. T. 1878−1960: master of language and surgery
Authors: Mellick Sam
Published: August 2004

Sir Gordon Gordon‐Taylor was the pre‐eminent British surgeon of the first half of the twentieth century. He became known for his daring cancer surgery which he perfected at the Middlesex Hospital, and he promoted early operation for abdominal gunshot wounds in World War I. During World War II, as a surgeon rear admiral, he was not only an active surgeon in the London region, but he also acted as a significant ambassador for Allied surgery. After the War he was in great demand as an eponymous orator throughout the length and breadth of Great Britain and abroad, and he encouraged many Commonwealth surgeons, particularly those from Australia and New Zealand, to further their training in Britain and then he actively supported them in their later careers. His death following an accident in 1960 was mourned through the surgical world.
Metastatic basal cell carcinoma: rapid symptomatic response to Cisplatin and Paclitaxel
Authors: Jefford Michael , Kiffer John D. , Somers Gino , Daniel Fredy J. , Davis Ian D.
Published: August 2004

Background:  Basal cell carcinoma (BCC) is the most common cancer in the community, although it rarely metastasizes. The literature reports less than 100 patients who have received chemotherapy for metastatic BCC. A further case of this rare disease is reported here. The pattern of disease in the reported patient was similar to that described in the literature, but the patient experienced a long period with untreated metastatic disease compared with that in the literature.

Method:  The patient was treated with cisplatin in combination with paclitaxel. Literature review suggests this to be the first report of this combination.

Results:  Rapid symptomatic response was achieved though late neurotoxicity occurred.

Conclusion:  This regimen is an active combination for the rare patient with metastatic BCC. The combination of carboplatin and paclitaxel causes less neurotoxicity and may therefore be a superior regimen.
Stress‐induced assortative mating and the evolution of stress resistance
Authors: Winterer Juliette , Weis Arthur E.
Published: August 2004

We show with a model that variation in environmental stress between generations facilitates the evolution of stress resistance through assortative mating. Stress induces delayed maturation of susceptible phenotypes, segregating their fertile period from resistant phenotypes. Assortment of mates enhances the responsiveness of populations to natural selection by inflating genetic variance. Thus, positive selection and inflated genetic variance in stressful environments can cause a strong evolutionary increase in resistance. By contrast, benign environments do not segregate phenotypes, and the random mating among phenotypes deflates genetic variance, leading to a weaker response to selection against resistance, assuming that resistance is costly. When environments vary randomly from benign to stressful, populations respond asymmetrically to negative and positive selection. This asymmetry (1) accelerates fixation of a resistance allele if resistance is generally favoured (stressful generations more frequent) but delays the loss of the allele if it is generally disfavoured (benign generations more frequent), and (2) it can push a resistance allele to fixation even when long‐term costs modestly exceed benefits. When resistance alleles pleiotropically delay mating, stress‐induced random mating has complementary effects. Serial autocorrelation in the stressor amplifies these effects. These results suggest a novel mechanism for the persistence of resistance polymorphisms.
Symbolic dynamics for identifying similarity between rhythms of ecological time series
Authors: Cazelles Bernard
Published: August 2004

Explaining the associations between animal populations or between population and environmental signals is an important challenge. The time series that quantify animal populations are often complex, nonlinear, noisy and non‐stationary. These characteristics may make it inappropriate to use traditional techniques when analysing these time series and their mutual dependencies. Here I propose to use symbolic dynamics and techniques from Information Theory to evaluate the degree of dynamic cohesion between time series fluctuations. The main idea is to check whether two (or more) signals tend to oscillate simultaneously, rising and falling together with the same rhythm. Based on synthetic and real time series, I demonstrate that this method is robust to the presence of noise and to the short length of the analysed time series and gives relevant information about the weak relationships between different series. Furthermore, this method appears as simple as classical cross‐correlation and outperforms it in the analysed examples.
Allee effects, mating systems and the extinction risk in populations with two sexes
Authors: Bessa‐Gomes Carmen , Legendre Stéphane , Clobert Jean
Published: August 2004

The Allee effect is one of the population consequences of sexual reproduction that has received increased attention in recent years. Due to its impact on small population dynamics, it is commonly accepted that Allee effects should render populations more extinction prone. In particular, monogamous species are considered more susceptible to the Allee effect and hence, more extinction prone, than polygamous species. Although this hypothesis has received theoretical support, there is little empirical evidence. In this study, we investigate (1) how variation in tertiary sex ratio affects the presence and intensity of the Allee effect induced by mating system, as well as (2) how this effect contributes to extinction risk. In contrast with previous predictions, we show that all mating systems are likely to experience a strong Allee effect when the operational sex ratio (OSR) is balanced. This strong Allee effect does not imply being exceptionally extinction prone because it is associated with an OSR that result in a relatively small extinction risk. As a consequence, the impact of Allee effects on overall extinction risk is buffered. Moreover, the OSR of natural populations appears to be often male biased, thus making it unlikely that they will suffer from an Allee effect induced by mating system.
Generalist and specialist lepidopteran larvae elicit different transcriptional responses in Nicotiana attenuata, which correlate with larval FAC profiles
Authors: Voelckel Claudia , Baldwin Ian T.
Published: August 2004

Unlike generalist herbivores, specialists are believed to share a history of evolutionary interactions with their host plants. We determine whether a specialist lepidopteran species alters plant metabolism differently from two generalist species despite similarities in feeding mode and larval elicitors. With a cDNA microarray enriched in defence‐related genes, we compared the transcriptional responses elicited in the native tobacco Nicotiana attenuata by the oligophagous larvae of Manduca sexta and the polyphagous larvae of Heliothis virescens and Spodoptera exigua, which are all members of N. attenuata's natural herbivore community. We found the differences in plant responses to be correlated with the profile of larval elicitors [fatty acid–amino acid conjugates (FAC)] and discuss how variation in FAC composition may shape the interaction between generalist or specialist lepidopteran larvae and plants.
Biodiversity response to climate change in a warm deep sea
Authors: Danovaro Roberto , Dell'Anno Antonio , Pusceddu Antonio
Published: August 2004

Climate changes are expected to induce significant modifications in biodiversity on the global scale, but little is known as to how biodiversity has been affected by recent changes in the deep sea. We have used nematodes to investigate the response of deep‐sea biodiversity to an extensive climate anomaly that modified the physico‐chemical characteristics of the deep waters of the Eastern Mediterranean. Using a decadal data set (from 1989 to 1998), we provide evidence that deep‐sea nematode diversity can be strongly and rapidly affected by temperature shifts. The abrupt decrease in temperature (of about 0.4 °C) and modified physico‐chemical conditions that occurred between 1992 and 1994 caused a significant decrease in nematode abundance and a significant increase in diversity. This temperature decrease also resulted in decreased functional diversity and species evenness, and in an increase in the similarity to colder deep‐Atlantic fauna. When the temperature recovered (after 1994–1995), the biodiversity only partially returned to previous values. We conclude that deep‐sea fauna is highly vulnerable to environmental alteration, and that deep‐sea biodiversity is also significantly affected by very small temperature changes. The results presented here provide new elements towards a better understanding of the potential large‐scale consequences of climate change.
Invasion impacts local species turnover in a successional system
Authors: Yurkonis Kathryn A. , Meiners Scott J.
Published: August 2004

Exotic plant invasions are often associated with declines in diversity within invaded communities. However, few studies have examined the local community dynamics underlying these impacts. Changes in species richness associated with plant invasions must occur through local changes in extinction and/or colonization rates within the community. We used long‐term, permanent plot data to evaluate the impacts of the exotic vine Lonicera japonica. Over time, species richness declined with increasing L. japonica cover. L. japonica reduced local colonization rates but had no effect on extinction rates. Furthermore, we detected significant reductions in the immigration of individual species as invasion severity increased, showing that some species are more susceptible to invasion than others. These findings suggest that declines in species richness associated with L. japonica invasion resulted from effects on local colonization rates only and not through the competitive displacement of established species.
Effects of fine grain environmental variability on morphological plasticity
Authors: Miner Benjamin G. , Vonesh James R.
Published: August 2004

Virtually all studies investigating morphological plasticity have focused on how organisms change in response to treatments that are constant throughout the experiment but which have different means. In this study, we investigated the possibility that organisms can morphologically respond to other environmental parameters like the amount of environmental variability or environmental maximum. Sea urchin larvae adjust the length of their feeding structure, a band of cilia, in response to different mean food concentrations. We investigated whether sea urchin larvae are also capable of responding to environmental variability or maxima by rearing larvae on four fluctuating diets, where all treatments had the same mean concentration of food. Larvae reared on a low variable diet produced longer larval arms (i.e. a longer ciliary band) than larvae reared on more variable diets. This response is similar to the morphological change that occurs when the mean food concentration is reduced (small mean = long arms), and indicates that organisms can morphologically respond to environmental parameters other than the environmental mean – such as the amount of environmental variability or the environmental maxima. We also quantified the shape of the relationship between larval arm length and fixed food concentrations to determine whether our results might be explained by nonlinearity in this relationship (i.e. Jensen's inequality). The shape of the relationship was inconsistent with a Jensen's inequality explanation. In addition, sea urchin larvae were unable to track fluctuations in food concentrations. This inability to track our imposed environmental fluctuations indicates that there was a time delay greater than 2 days in the response of larvae to changes in food concentrations. Since plutei likely experience fluctuations in food concentrations at least once a day, it is possible that larvae cannot track natural fluctuations in food concentration. We discuss the importance of our results in light of adaptive interpretations of plasticity and predictions of morphological response.
Protein accumulation and distribution in floodplain soils and river foam
Authors: Harner Mary J. , Ramsey Philip W. , Rillig Matthias C.
Published: August 2004

Many processes contribute to nutrient transfer from terrestrial to aquatic systems, but in most cases the contribution of particular organisms is unknown. In this study, we explore how a Bradford‐reactive soil protein (BRSP) produced by arbuscular mycorrhizal fungi may provide nutrients to river ecosystems. Along a floodplain in Montana, we extracted BRSP from soils and related the protein concentrations to the age of soil surfaces. We identified BRSP in surface soils, as well as to a depth of 1.4 m, and found that the protein accumulates through time. We also detected BRSP in foam from five rivers in the western United States. Experiments were conducted that demonstrate that the protein may be leached or washed from soils and become a constituent of foam when mixed into turbulent water. We propose that terrestrially derived soil protein may enter rivers via erosion and leaching and serve as a nutrient source for aquatic organisms.
The effect of a pathogen epidemic on the genetic structure and reproductive strategy of the crustacean Daphnia magna
Authors: Mitchell Suzanne E. , Read Andrew F. , Little Tom J.
Published: August 2004

Host–parasite coevolution is potentially of great importance in producing and maintaining biological diversity. However, there is a lack of evidence for parasites directly driving genetic change. We examined the impact of an epidemic of the bacterium Pasteuria ramosa on a natural population of the crustacean Daphnia magna through the use of molecular markers (allozymes) and laboratory experiments to determine the susceptibility of hosts collected during and after the epidemic. Some allozyme genotypes were more heavily infected than others in field samples, and the population genetic structure differed during and after the epidemic, consistent with a response to parasite‐mediated selection. Laboratory studies showed no evidence for the evolution of higher resistance, but did reveal an intriguing life‐history pattern: host genotypes that were more susceptible also showed a greater tendency to engage in sex. In light of this, we suggest a model of host–parasite dynamics that incorporates the cycles of sex and parthenogenesis that Daphnia undergo in the field.
Distinctiveness magnifies the impact of biological invaders in aquatic ecosystems
Authors: Ricciardi Anthony , Atkinson Susanna K.
Published: August 2004

There exist few empirical rules for the effects of introduced species, reflecting the context‐dependent nature of biological invasions. A promising approach toward developing generalizations is to explore hypotheses that incorporate characteristics of both the invader and the recipient system. We present the first general test of the hypothesis that an invader's impact is determined by the system's evolutionary experience with similar species. Through a meta‐analysis, we compared the taxonomic distinctiveness of high‐ and low‐impact invaders in several aquatic systems. We find that high‐impact invaders (i.e. those that displace native species) are more likely to belong to genera not already present in the system.
Having the guts to compete: how intestinal plasticity explains costs of inducible defences
Authors: Relyea Rick A. , Auld Josh R.
Published: August 2004

Predators commonly induce phenotypic changes that make prey better at surviving predation at the cost of reduced growth. While we have a good understanding of how trait changes affect predation risk, we lack a mechanistic understanding of why predator‐induced phenotypes differ in growth. Using two mesocosm experiments, we combined phenotypic plasticity theory with predictions from optimal digestion theory to demonstrate that intra‐ and interspecific competition induced relatively long guts while predators induced relatively short guts. The longer guts induced by competition appear to be an adaptive response that allows more efficient digestion and more rapid growth whereas the shorter guts induced by predators appear to result from a tradeoff of building larger tails in predator environments at the cost of smaller bodies. By combining these two bodies of theory, we now have a much better understanding of the mechanisms that cause the phenotypic trade‐offs that select for inducible defences.
Stoichiometry and population dynamics
Authors: Andersen Tom , Elser James J. , Hessen Dag O.
Published: August 2004

Population dynamics theory forms the quantitative core from which most ecologists have developed their intuition about how species interactions, heterogeneity, and biodiversity play out in time. Throughout its development, theoretical population biology has built on variants of the Lotka–Volterra equations and in nearly all cases has taken a single‐currency approach to understanding population change, abstracting populations as aggregations of individuals or biomass. In this review, we explore how depicting organisms as built of more than one thing (for example, C and an important nutrient, such as P) in stoichiometrically explicit models results in qualitatively different predictions about the resulting dynamics. Fundamentally, stoichiometric models incorporate both food quantity and food quality effects in a single framework, allow key feedbacks such as consumer‐driven nutrient recycling to occur, and generally appear to stabilize predator–prey systems while simultaneously producing rich dynamics with alternative domains of attraction and occasionally counterintuitive outcomes, such as coexistence of more than one predator species on a single‐prey item and decreased herbivore performance in response to increased light intensity experienced by the autotrophs. In addition to the theoretical background, we also review recent laboratory and field studies considering stoichiometric effects on autotroph–herbivore systems, emphasizing algae–Daphnia interactions. These studies support the predictions of stoichiometric theory, providing empirical evidence for alternative stable states under stoichiometric constraints, for negative effects of solar radiation on herbivores via stoichiometric food quality, and for diversity‐enhancing effects of poor food quality. Stoichiometric theory has strong potential for both quantitative and qualitative improvements in the predictive power of population ecology, a major priority in light of the multivariate anthropogenic and natural perturbations experienced by populations. However, full development and testing of stoichiometric population dynamics theory will require greater intellectual tolerance and exchange between researchers working in ecosystem and population ecology.
Elevated CO2 and herbivory influence trait integration in Arabidopsis thaliana
Authors: Gabriela Bidart‐Bouzat M. , Portnoy Stephen , DeLucia Evan H. , Paige Ken N.
Published: August 2004

We lack information on how elevated CO2, and its interaction with other factors like herbivory, affect levels and patterns of trait integration in plants. We experimentally tested the hypothesis that elevated CO2 disrupts and restructures functional associations among plant traits, in the selfing annual, Arabidopsis thaliana. We tested for these effects both in the presence and absence of herbivory by larvae of the diamondback moth, Plutella xylostella. Elevated CO2, both alone and combined with moth herbivory, modified integrated trait responses. In addition, integration under different environments was genotype‐specific. These results imply that global changes in CO2 are likely to cause divergent evolutionary outcomes among populations of plants that differ in the initial structure of their quantitative genetic variation.
Increased susceptibility to enemies following introduction in the invasive plant Silene latifolia
Authors: Wolfe Lorne M. , Elzinga Jelmer A. , Biere Arjen
Published: August 2004

One of the influential hypotheses invoked to explain why species become invasive following introduction is that release from natural enemies favours a shift in investment from defence to traits enhancing growth and reproduction. Silene latifolia was introduced from Europe (EU) to North America (NA) c. 200 years ago where it experiences lower damage by natural enemies. A common garden experiment in EU using seeds from 20 EU and 20 NA populations revealed (1) genetically‐based differences in life history between plants from EU and NA; plants from NA have evolved a weedy phenotype that flowers earlier, and has a two‐ to threefold higher reproductive potential; (2) higher susceptibility of NA plants to fungal infection, fruit predation, and aphid infestation. These results suggest that the invasive NA phenotype has evolved at the expense of defensive abilities. Despite this increased susceptibility to enemies, NA populations still outperformed EU populations in this common garden.
Cullen frontal sinus valved glaucoma shunt: preliminary findings in dogs with primary glaucoma
Authors: Cullen Cheryl L.
Published: August 2004

Purpose To evaluate the efficacy of a novel, professionally manufactured, frontal sinus valved glaucoma shunt in maintaining normal intraocular pressure (IOP) and vision in dogs with primary glaucoma.

Methods Three eyes of three dogs diagnosed with primary glaucoma were included in this prospective clinical study. A Cullen frontal sinus valved glaucoma shunt was implanted into each glaucomatous globe. Dogs were treated postoperatively with topical neomycin/polymyxin B/0.1% dexamethasone and 0.03% flurbiprofen every 6 h tapered over 8–12 weeks, and meloxicam at 0.1 mg/kg orally every 24 h for 7–10 days. IOP, intracameral shunt position and apparent patency, and vision were assessed twice daily for up to 4 (n= 3 eyes) and 10 (n= 2 eyes) days postoperatively, and then at re‐examination periods of up to 36 weeks (n= 1 eye). Postoperative complications were recorded and documented photographically.

Results Normal IOP was maintained in all shunted globes (range 10–29 mmHg; mean = 16.7 mmHg at 24 h; IOP = 23 mmHg at 36 weeks) postoperatively for 2 days (3/3 eyes), 8 weeks (2/2 eyes), and 36 weeks (1/1 eye) without additional antiglaucoma therapies. Photopic vision and shunt position and patency were maintained in all shunted globes for all follow‐up periods. Postoperative complications included mild aqueous flare and fibrin (n= 3 eyes for 3–10 days postoperatively); intracameral shunt occlusion with fibrin (n= 1 eye at days 2 and 4); partial anterior chamber tube extrusion (n= 1 eye at day 4), and focal corneal edema (n= 1 eye at 18 weeks). Tissue plasminogen activator injected intracamerally through the silicone tube near the frontal sinus effectively resolved the fibrinous shunt occlusion.

Conclusions The Cullen frontal sinus valved glaucoma shunt shows promise for the management of canine primary glaucoma.
Clinical experience with butyl‐2‐cyanoacrylate adhesive in the management of canine and feline corneal disease
Authors: Watté Christine M. , Elks Rebecca , Moore Denise L. , McLellan Gillian J.
Published: August 2004

Purpose  To examine and evaluate clinical indications and postoperative outcome in a series of small animal patients in which corneal disease was managed by the application of butyl 2‐cyanoacrylate adhesive.

Materials and methods  In this retrospective study all small animal patients were identified that presented to the Royal Veterinary College, University of London over a 2‐year period, in which corneal disease was managed by the application of butyl 2‐cyanoacrylate. Indications for application, complicating factors prior to gluing, glue retention time, postoperative comfort, and extent of subsequent corneal reaction and scarring were noted for each case. Long‐term follow‐up data concerning visual and cosmetic outcome were obtained from owners and referring veterinarians.

Results  Thirty‐seven patients (28 dogs and 9 cats), in which 39 eyes were treated, were identified. Indications for corneal gluing in this series included stromal ulceration (26/39 eyes); descemetocele (4/39 eyes); corneal laceration/foreign body (5/39 eyes); lamellar keratectomy (3/39 eyes) and superficial ulceration (1/39 eyes). At least one factor responsible for initiation, persistence or progression of the ulcer was identified in 66.7% of eyes prior to corneal gluing. These included keratomalacia; confirmed bacterial keratitis; corneal edema related to endothelial disease and keratoconjunctivitis sicca. Cyanoacrylate was generally well tolerated by patients with only 8/34 eyes demonstrating transient blepharospasm and increased lacrimation postoperatively. Retention time of cyanoacrylate varied widely from < 1 week to approximately 6 months, but was < 2 months in the majority (89%) of eyes. Exaggerated corneal vascularization was an infrequent postoperative complication, noted in only six canine eyes, and did not appear to be related to initial corneal disease, glue retention time or breed.

Conclusions  Butyl 2‐cyanoacrylate offers a convenient, economical and effective alternative to other treatment modalities, such as conjunctival grafts, in the management of corneal defects in canine and feline patients.
The use of semiconductor diode laser for deflation and coagulation of anterior uveal cysts in dogs, cats and horses: a report of 20 cases
Authors: Gemensky‐Metzler Anne J. , Wilkie David A. , Cook Cynthia S.
Published: August 2004

Objective To describe semiconductor diode laser use for anterior uveal cyst deflation and coagulation in dogs, horses and cats.

Animals studied The presenting clinical signs, surgical technique and postoperative results for four dogs, nine horses and seven cats with anterior uveal cysts treated with diode laser are described. Treated cysts were of sufficient size and/or number to potentially impair vision, damage the corneal endothelium, or increase intraocular pressure (IOP). One dog with free‐floating cysts exhibited ‘fly biting’ behavior. Cysts were suspected of causing shying on the affected side and/or head‐shaking behavior in seven horses. Cysts were free floating within the anterior chamber in dogs, occurred in the corpora nigrum in horses and were attached to the posterior iris surface in cats. In cats, shallowing of the anterior chamber and dyscoria were observed. In all cats prior to cyst deflation, IOP increased after pharmacologic pupil dilation. Cats were more likely than dogs and horses to have bilateral and multiple cysts.

Procedure Two dogs and all horses were treated without general anesthesia and two dogs and all cats were treated under general anesthesia. Diode laser was used to perforate, deflate and coagulate the cysts.

Results Postoperatively, all eyes were free of discomfort or significant inflammation and minimal or no topical or systemic anti‐inflammatory therapy was required. Abnormal behavior improved or resolved in all cases. In all cats, IOP 24 h after photocoagulation was lower than the postdilation IOP. Cysts did not recur, but new cysts were discovered in several cases.

Conclusion Semiconductor diode laser coagulation of anterior uveal cysts is safe, effective and noninvasive.
Microbial contamination of the anterior chamber during cataract phacoemulsification and intraocular lens implantation in dogs
Authors: Ledbetter Eric C. , Millichamp Nicholas J. , Dziezyc Joan
Published: August 2004

The objective of this study was to determine the frequency of intraoperative contamination of the anterior chamber with viable microorganisms during cataract phacoemulsification and intraocular lens implantation, and to evaluate the relationship of contaminant microorganisms to patients’ extraocular and nasal cavity floras. Also, the impact of various aspects of the patient history and phacoemulsification procedure on the incidence of positive postoperative anterior chamber cultures was investigated. Twenty‐two eyes from 13 dogs presented for elective cataract phacoemulsification and intraocular lens implantation were studied. Preoperatively, microbiologic samples of the conjunctiva, eyelid margins, nares, and rostral nasal cavity were collected. Postoperatively, anterior chamber fluid was aspirated. Samples were submitted for aerobic/anaerobic bacteriologic culture and antimicrobial susceptibility, Mycoplasma culture, and fungal culture. Anterior chamber aspirates collected at the conclusion of surgery were culture positive for at least one organism in 22.7% of eyes. Three aerobic bacteria and three fungi were isolated from the anterior chamber aspirates. Two fungi and one bacterium isolated from the anterior chamber were typed identically, and the bacterium had a similar antibiogram to organisms recovered from the patient's conjunctiva and eyelid margin. No statistically significant difference in contamination frequency was found for the investigated patient and surgical variables. We conclude that intraoperative contamination of the anterior chamber with viable bacterial and fungal organisms is a common occurrence in canine patients undergoing cataract phacoemulsification and intraocular lens implantation, and the external ocular flora is a likely source of some of these contaminating microorganisms. This contamination is independent of the patient and surgical variables investigated.
Use of topical mitomycin C in myoplasty of the medial rectus muscle of rabbits
Authors: Mamede Fabrício V. , Laus José L. , Cabral Vânia P. , Vicenti Felipe A. M. , Barbieri‐Neto José
Published: August 2004

To possibly reduce postoperative adhesions that occur after ocular myoplasties, we investigated the topical effects of 0.04% mitomycin C on the repaired areas of the medial rectus muscle using an equine renal capsule preserved in 98% glycerin for reinforcement of the sutures. Twenty‐four rabbits, divided into two groups of 12 animals each [untreated (control) and treated group (MMC)], were submitted to surgical rupture of the medial rectus muscle of one eye and repair of the defect 24 h later with sutures and an equine renal capsule. Post‐operative prophylactic treatment of the two groups consisted of the administration of eye drops containing neomycin, polymyxin B and dexamethasone at regular 6‐h intervals for eight consecutive days and daily rinsing with physiological saline. MMC animals received additional treatment with topical 0.04% mitomycin C every 6 h for 14 consecutive days. Slit lamp biomicroscopy showed greater irritation of the ocular surface in MMC animals during the first days post operatively. Adhesions were observed at 15 and 30 days of assessment in the two groups, but were more extensive in control animals at 60 days. Histopathology revealed inflammatory exudation in both groups, which was greater in MMC animals. Mitomycin C (0.04%) instilled at 6‐h intervals for 14 consecutive days reduced the occurrence of fibrosis in the myoplastic areas. However, the equine renal capsule was found to be of little benefit for the reinforcement of myoplasties.
Surgical management and histologic and immunohistochemical features of a cataract and retrolental plaque secondary to persistent hyperplastic tunica vasculosa lentis/persistent hyperplastic primary vitreous (PHTVL/PHPV) in a Bloodhound puppy
Authors: Gemensky‐Metzler Anne J. , Wilkie David A.
Published: August 2004

The objective of this study was to describe the clinical, histologic and immunohistochemical features, the surgical treatment, and outcome of a cataract secondary to persistent hyperplastic tunica vasculosa lentis/persistent hyperplastic primary vitreous (PHTVL/PHPV) in a dog. A 4‐month‐old male Bloodhound dog presented for evaluation of a cataract. A complete ophthalmic examination and ocular ultrasonography were performed. A resorbing cataract with intralenticular hemorrhage, lens induced uveitis, and PHTVL/PHPV were diagnosed. Extracapsular cataract extraction using phacoemulsification was performed. A primary posterior capsulectomy was performed to remove a retrolental plaque with the posterior capsule; the excised plaque was submitted for histopathology and immunohistochemical staining. A 41‐Diopter intraocular lens (IOL) was implanted. Functional vision was maintained postoperatively during the 21‐month follow‐up period. Histologically, the posterior capsule was coiled and exhibited duplication. The retrolental plaque was comprised of dense fibrous connective tissue, blood vessels, free red blood cells, hemosiderin‐laden macrophages, a pocket of neural tissue and numerous perivascular mast cells. With immunohistochemical staining, the neural elements were determined to be glial cells compatible with astrocytes. Cataract secondary to PHTVL/PHPV can be successfully treated using phacoemulsification and planned posterior capsulectomy. Posterior lens capsule duplication, mast cells and astrocytic glial cells may be normal components of the fibrovascular retrolental plaque associated with PHTVL/PHPV.
Adnexal surgery in dogs and cats
Authors: Van Der Woerdt Alexandra
Published: August 2004

Abnormalities in eyelid position and function can lead to chronic irritation of cornea and conjunctiva. Corneal ulceration, vascularization and pigmentation are common consequences. Loss of vision, or loss of the globe may be the end result. The combination of ptosis and entropion of the upper eyelid is commonly seen in breeds with abundant forehead skin folds. Treatment options include surgical reduction of skin folds, suspending the brows, enforced secondary granulation of the upper eyelid, or a combination of procedures. Lid‐shortening procedures reduce corneal exposure, improve functional blinking and reduce likelihood of traumatic proptosis. Although a lateral canthoplasty is technically easier to perform, a medial canthoplasty is the preferred method of eyelid shortening. An involuted lateral canthus with entropion is seen in certain dog breeds with a broad skull base and redundant facial skin. Surgical correction is by either applying traction to the lateral canthus, or by resection of the lateral canthal ligament. A combination of entropion, ectropion and macroblepharon may result in the presence of diamond shaped eyelids. Surgical correction involves the combination of several procedures. Upper eyelid agenesis is a congenital absence of part of the upper eyelid in cats. Treatment options include a skin–orbicularis flap from the lower eyelid with a conjunctival pedical graft, the transposition of the lower eyelid to the upper eyelid, cross lid flap and subdermal plexus flap, and subdermal collagen injection. Several techniques for reconstruction of upper and lower eyelid defects are described.
Retrospective study of prophylactic random transscleral retinopexy in the Bichon Frise with cataract
Authors: Schmidt Gretchen M. , Vainisi Samuel J.
Published: August 2004

The objective of this study was to determine the efficacy of prophylactic random transscleral retinopexy (PRTR) in preventing rhegmatogenous retinal detachment (RRD) in the Bichon Frise with juvenile cataract. The medical records were reviewed from a private veterinary ophthalmology practice of nondiabetic Bichon Frise dogs younger than 11 years that had inherited cortical cataracts in one or both eyes and that had a follow‐up examination after at least 9 months. Eyes were included in the study if the fundus could be visualized by indirect ophthalmoscopy at the last examination either because of phacoemulsification or resorption of the cataract. Four groups of eyes were identified. In group 1, no PRTR was performed and there was resorption of the cataract; in group 2, eyes had no PRTR performed and phacoemulsification of the cataract. Group 3 had PRTR performed and resorption of the cataract. In group 4, PRTR was performed as was phacoemulsification of the cataract. In group 1, 20 eyes had resorbed cataracts, and 12 (60%) of these had RRD. In group 2, 18 eyes had phacoemusification of the cataract, and 10 (55%) of these had RRD. In group 3, 19 eyes had PRTR and resorbed cataracts, and 2 (10%) of them had RRD. In group 4, 39 eyes had PRTR and phacoemulsification of the cataract; of these 5 (12%) had RRD. The Bichon Frise dog with inherited cataract is at high risk of RRD. PRTR reduces this risk.