Brown Syndrome Research Articles

Accuracy of the Image Interpretation Capability of ChatGPT-4 Vision in Analysis of Hess Screen and Visual Field Abnormalities.

OpenAI, the owner of ChatGPT, publicly released the GPT-4 Vision in September 2023. This multimedia chatbot has the capability to receive and analyze various images presented to it by the user. We assessed the accuracy of its interpretation of 2 of the images commonly used in neuro-ophthalmology, namely Hess screen and automated visual field images. We separately uploaded typical images of 5 abnormal Hess screen charts related to third, fourth, and sixth cranial nerve palsy, Brown syndrome, and inferior orbital wall fracture with entrapment of the inferior rectus muscle. Likewise, 5 classic images of automated visual field grayscale maps related to lesions of the optic nerve, the chiasma, the optic tract, the optic radiations, and the occipital lobe were presented. The chatbot was instructed to select the best option among the 5 choices presented in each question. The GPT-4 Vision was able to select the right choice in 2/5 questions on Hess screens and 3/5 of the visual field questions. Despite selection of the correct option, qualitative evaluation of GPT-4 responses revealed flawed analysis of certain aspects of some image findings, such as the side of involvement or the misinterpretation of the physiologic blind spot as a central scotoma. The performance of GPT-4 Vision in the interpretation of abnormalities of Hess screen and visual field involvement was highly variable, even with simple typical cases of classic disorders. As the chatbot's image recognition is currently evolving, its capacity to accurately interpret ophthalmologic images is still limited at this time.

European brown hare syndrome virus and other lagoviruses of interest.

This focus article was prepared by Paul Duff of the APHA Wildlife Expert Group, with support from David Everest (APHA Pathology Department), Lucy Martindale (APHA Surveillance Intelligence Unit), Alex Barlow (Wildlife Network for Disease Surveillance), Mara Rocchi (Moredun Research Institute) and Antonio Lavazza (Istituto Zooprofilattico Sperimentale della Lombardia e dell'Emilia Romagna, Italy).

S3095 Vitamin E Supplementation in Brown Bowel Syndrome: A Case of Diagnostic Challenge and Therapeutic Success

S3095 Vitamin E Supplementation in Brown Bowel Syndrome: A Case of Diagnostic Challenge and Therapeutic Success

Traumatic superior oblique tendon rupture with ptosis: A case report

The traumatic rupture of the superior oblique tendon with ptosis is extremely rare, and the surgical treatment is very challenging. We reported a case of a 41-year-old man with superior oblique tendon rupture and ptosis due to an iron hook injury. The ocular movement disorders were not obvious except for mild superior oblique underaction but were accompanied by severe extorsion. The distal stump of the superior oblique tendon was shortened and anchored to the periosteum of the supra-nasal orbital margin near the trochlea. Post-operative follow-up revealed the surgical outcome was better than expected, which resulted in significant improvement in binocularity and cosmetic outcomes without complication in the present case. The exploration of the levator palpebral superioris (LPS) in the early post-traumatic stage might not be necessary in circumstances without eyelid laceration. Shortening and anchoring of the ruptured superior tendon could restore almost normal binocularity, decrease the extorsion, and avoid acquired Brown syndrome.

Small tuck for superior oblique palsy

PurposeTo investigate the surgical outcomes of small superior oblique (SO) tuck—denoting minimal tendon laxity—in patients with unilateral SO palsy. MethodsThe medical records of consecutive patients treated with ≤6 mm SO tuck from 2000 to 2018 at Kellogg Eye Center, University of Michigan, were reviewed retrospectively. Tendon tucks were performed to a fairly uniform tension in an amount that just eliminated slack in the tendon. Pre- and postoperative motility measurements were compared. Patients were excluded if they had a history of prior strabismus surgery or concurrent vertical rectus or inferior oblique surgery. ResultsA total of 27 cases (14 males) met inclusion criteria. The median age at surgery was 47 years (range 3–74 years). The mean SO tuck (total, both arms of tuck) was 4.9 mm (range, 2–6 mm). After surgery, median hypertropia decreased from 9Δ to 1Δ in primary position and from 20Δ to 4Δ in the SO field of action (contralateral downgaze). Lateral incomitance (difference in hypertropia between contralateral and ipsilateral gaze) decreased from 10Δ to 2Δ (P < 0.001 in each case). Six patients had diplopia in upgaze postoperatively that was not symptomatic enough to require reoperation. Six patients had residual hypertropia requiring additional surgery. ConclusionsSmall SO tuck provided disproportionate correction of hypertropia in the SO field of action and nearly eliminated lateral incomitance without producing unacceptable iatrogenic Brown syndrome. Even in the absence of tendon laxity, SO tuck was a good surgical option for SO palsy in our cohort where there was marked lateral incomitance and the greatest deviation was in the SO field of action.

Overview of Brown-Sequard Syndrome.

A neurologic syndrome called Brown-Séquard syndrome is brought on by spinal cord hemisection. On the side of the body, ipsilateral to the lesion, it presents as weakness or paralysis, proprioceptive abnormalities, and loss of pain and temperature perception. Brown-Séquard syndrome is an incomplete spinal cord syndrome with a range of severity in its clinical presentation.&#x0D; One of the most intricate and fascinating areas of the nervous system to study is the spinal cord. Its overwhelming clinical presentation, development problems, lesions, and intricate connections call for a deeper comprehension of its anatomical and physiological makeup.&#x0D; Like the brain, the extremely fragile and sensitive spinal cord is well-protected by the robust bony cage comprising the vertebral arch and vertebral bodies. Together, they create the spinal hollow, or long spinal column, which houses the spinal cord. Millions of neurons reside in the spinal cord, and their bundled fibers run as ascending or descending tracts. Thirty-one pairs of spinal nerves, primarily supplying the trunk and limbs, emerge from the spinal cord. These are mixed spinal nerves with a motor component that assists in controlling the trunk and voluntary muscles in all limbs. Additionally, they have a sensory component that aids in taking in the sensory data from these regions. Therefore, for a better understanding of the clinical presentation and its pathology in any spinal cord lesion, it is imperative to grasp the fundamentals of anatomy.&#x0D; In this short review, we have discussed the symptoms, management, and prevention of brown syndrome.

The algorithm of diagnosis and surgical treatment of Brown’s syndrome

Introduction. Brown’s syndrome (BS) is a rare type of unconcomitant strabismus, which is often interpreted by practicing ophthalmologists as a paralytic form. The difficulty of diagnosis is due to the similarity of clinical manifestations with a number of other oculomotor disorders. This leads to a late, and most importantly, tactically incorrect choice of surgical treatment method. Purpose: Development of an algorithms for differential diagnosis and surgical treatment of Brown syndrome. Materials and methods. The authors analyzed the experience of diagnosing and treating 99 patients with Brown’s syndrome. The follow-up period was 13 years, from May 2010 to May 2023. Among the examined patients, 35 (35 %) were male and 64 (65 %) were female. The median age was 7.19 ± 0.87 years, the oldest at the time of the study was 45 years old, and the youngest was 1.5 years old. All patients underwent standard ophthalmologic and strabismal examinations. In patients of verbal age, the nature of vision was examined (Worth test, Bagolini test, double Maddox test). All operated patients underwent a cyclotorsion test intraoperatively under general anesthesia to confirm the diagnosis and choose a surgical method. Surgical treatment was carried out in 60 cases of unilateral and 5 cases of bilateral BS (a total of 65 patients aged 2 to 45 years; 69 eyes). Tenotomy and tenectomy of the superior oblique muscle (ECM) were performed in 53 cases, prolongation and recession with prolongation of the ECM in 16 cases. Results. Clinical signs have been systematized, algorithms for differential diagnosis and surgical treatment have been developed, which make it possible to timely identify Brown’s syndrome and carry out stage-by-stage pathogenetically based surgical treatment. The results are presented in the form of sequential action schemes (algorithms) that will help practitioners in making a diagnosis and determining the correct tactics of surgical treatment. Conclusions. Brown syndrome has characteristic differential features and requires staged surgical treatment. Developed algorithms to obtain high functional and cosmetic results.

Clinical effect of superior oblique re-tucking for recurrent or residual compensatory head position

Objective: To evaluate the effects of re-tucking the superior oblique muscle on recurrent or residual compensatory head position. Methods: A retrospective case series study was conducted. 12 recurrent or residual compensatory head position patients (12 eyes) with congenital superior oblique palsy who underwent superior oblique re-tucking in Tianjin Eye Hospital from March 2015 to February 2021 were included. All patients had a history of superior oblique tucking procedure and showed signs of superior oblique muscle palsy without inferior oblique muscle overaction. During surgery, the Guyton forced duction test is used to evaluate the relaxation of the superior oblique muscle tendon, which affects the re-tucking length of the muscle.Their head position, vertical deviation, eye movement, fovea-disa angle, and Bielschowsky head tilt test were assessed pre-and post-surgery. Statistical analysis was performed using ttest and paired samples Wilcoxon signed rank test. Results: Out of the 12 patients, 8 were male and 4 were female, aged between 2 and 9 years. The initial surgery was done at age 6, with a superior oblique recession length of (7.17±1.03) mm. Recurrent head tilt occurred in 11 patients after (3.82±0.98) months postoperatively, and 1 patient had residual head tilt, with a followup period of six months or more. Ocular motility examination revealed underaction of the superior oblique muscle, positive Bielschowsky's head tilt test, and Guyton forced duction tese indicating relaxation of the paralyzed superior oblique muscle tendon. Scar adhesion was observed at the stop of the superior oblique muscle, as well as the previous sutures. The scar and the sutures around the stop of the superior oblique muscle were released, the mean re-tucking amount was(7.83±1.59)mm. Follow-up at 12 to 18 months postoperatively showed disappearance of compensatory head position, significant improvement in superior oblique muscle lag, normal ocular motility, and no occurrence of Brown syndrome. The results of Bielschowsky head tilt were negative in 9 cases and still positive in 3 cases after superior oblique re-tucking. The primary vertical deviation was 2.5 (2.0, 5.3) prism diopter pre-operatively and 1 (0, 1) prism diopter post-operatively, respectively. The difference was statistically significant (U=6.00, P<0.001). The total amount of FDA in both eyes was (-22.04±5.47)° and (-15.27±6.08)° pre-and post-operatively, respectively. The difference was statistically significant (t=2.87, P=0.009). All 12 patients have normal eye movement after superior oblique re-tucking procedure. All patients had no compensatory head position at last follow-up. Conclusions: Superior oblique re-tucking is suitable for patients with relaxation of the superior oblique muscle tendon and extrocular rotation as the main sign. It can effectively and safely correct the recurrent or residual compensatory head position after re-tucking the superior oblique muscle.

Serological characterisation of Lagovirus virus-like particles originating from native and mutated VP60 of rabbit haemorrhagic disease virus 2 and European brown hare syndrome virus.

Since lagoviruses cannot be cultivated in vitro, using expression systems is an alternative and promising way of producing diagnostic viral antigens. It opens up their use as active immunogens for vaccine production. Virus-like particles (VLPs) were produced in a baculovirus expression system in Spodoptera frugiperda 9 (Sf9) insect cells based on wild-type and mutated variants of the virus capsid VP60 protein from a Polish strain of European brown hare syndrome virus (EBHSV) and wild-type and mutated versions of this protein from a Polish strain of rabbit haemorrhagic disease virus 2 (RHDV2). The mutations were the substitution of an arginylglycylaspartic acid (Arg-Gly-Asp/RGD) motif in the P2 subdomain and, in the S or P2 domain, the substitution of three lysines. The VLPs were purified with sucrose gradient ultracentrifugation. Protein production was confirmed by Western blot analysis using rabbit or hare sera and ELISA tests with different types of monoclonal antibody. The haemagglutination properties of some VLPs were also evaluated. Electron microscopy of wild-type EBHSV, wild-type RHDV2 and the four VP60 variants produced in this experiment revealed the formation of characteristic VLP structures. For the first time, mutated VLPs of RHDV2 with an RGD motif in the VP60 sequence were obtained, which could potentially be used to deliver cargo to eukaryotic cells. Virus-like particles based on the VP60 proteins of EBHSV and RHDV with a three-lysine substitution in the S or P2 domains were also obtained. Potential exists for VLPs of EBHSV and RHDV2 as vaccine candidates.

Effect of vertical central plication on vertical deviations

PurposeTo evaluate the surgical effect of the Wright central plication on vertical rectus muscles to correct vertical strabismus. MethodsIn this multicenter, retrospective, observational outcomes study, data were collected from two surgeons in different practice settings (2017-22). All patients who underwent vertical rectus central plication were included; those undergoing any concurrent strabismus surgery for vertical strabismus were excluded. Primary outcome was amount of strabismus correction in prism diopters per vertical rectus central plication. Secondary outcome was to determine factors associated with better or worse surgical outcomes and patient and patient responses. Data were analyzed using descriptive and bivariate statistics. ResultsA total of 36 patients were included. Mean age was 60 years. Mean follow-up was 8.4 months. Of the 36 patients, 11 (31%) had idiopathic strabismus, and 7 (19%) had congenital superior oblique palsy. The remainder had a history that included prior ocular surgery, trauma, and Brown syndrome; 16 (44 %) had prior strabismus surgery. Of 31patients with preoperative diplopia, 23 (74%) had postoperative resolution of diplopia, and 10 of 16 patients with preoperative prisms (63%) no longer required prisms postoperatively. Mean vertical deviation change was 4.7Δ. Subgroup analysis removing patients with congenital superior oblique palsy showed a larger response of 5.5Δ. 78% of patients had a final deviation <5Δ. No complications or induced postoperative diplopia was reported. ConclusionsIn our study cohort, vertical rectus central plication corrected approximately 5Δ (range, 4.5Δ-5.5Δ) of vertical strabismus due to a variety of causes.

The ‘brown envelope syndrome’: Culture of bribery and ethics at the crossroads

This article unravels the destructive practice of bribery, which is ingrained in South African culture. Through the scenarios in the public transport industry and literature review, the article reveals that indeed bribery is a reality to reckon with. It is observed in all tiers of society such as politics, businesses and religious circles. Bribery explained as a ‘brown envelope syndrome’ is rife in the South African socio-political landscape. The objective of this article is to enlighten the readers that bribery from socio-theological perspectives is ethically unacceptable. It promotes corrupt political accountability, economic inequality, social disrespect and religious hypocrisy. The article starts with personal scenarios and then delves into the definition of bribery as payment in a form of money, favours or gifts, to influence a decision, to receive favours in turn, facilitate fast delivery of goods, gain an unfair advantage, avoid legal prosecution or to supply substandard products or services. The second part of the artilce discusses how bribery clashes with Christian ethics as pointed by Jesus in Mark 7:21–22, as bribery lies buried in human hearts and manifests itself in different sins. There is a clear biblical condemnation of bribery as detestable, and that by all means possible, it should be proscribed. Bribery in political circles is known as ‘brown envelope’, which means the currency exchanges between the corrupt and the corrupted. Solutions suggested is that citizens in their national democracies should break out of the shell and become vocal against bribery. The church should emerge behind the trees and come up with prophetic discernment, wisdom and be vocal against bribery. Personally, those exposed to bribery situations must maintain wisdom and learn how to refuse offers without endangering themselves. This research unravels bribery and its devastating effects of promoting corrupt political accountability, economic inequality, social disrespect and religious hypocrisy.Contribution: This article calls for communities and churches to be vocal against bribery and encourages personal accountability when confronted with bribery offers.

A new HaCV-EBHSV recombinant lagovirus circulating in European brown hares (Lepus europaeus) from Catalonia, Spain

In 2020/2021, several European brown hare syndrome virus (EBHSV) outbreaks were recorded in European hares (Lepus europaeus) from Catalonia, Spain. Recombination analysis combined with phylogenetic reconstruction and estimation of genetic distances of the complete coding sequences revealed that 5 strains were recombinants. The recombination breakpoint is located within the non-structural protein 2C-like RNA helicase (nucleotide position ~ 1889). For the genomic fragment upstream of the breakpoint, a non-pathogenic EBHSV-related strain (hare calicivirus, HaCV; GII.2) was the most closely related sequence; for the rest of the genome, the most similar strains were the European brown hare syndrome virus (EBHSV) strains recovered from the same 2020/2021 outbreaks, suggesting a recent origin. While the functional impact of the atypical recombination breakpoint remains undetermined, the novel recombinant strain was detected in different European brown hare populations from Catalonia, located 20–100 km apart, and seems to have caused a fatal disease both in juvenile and adult animals, confirming its viability and ability to spread and establish infection. This is the first report of a recombination event involving HaCV and EBHSV and, despite the recombination with a non-pathogenic strain, it appears to be associated with mortality in European brown hares, which warrants close monitoring.

Brown syndrome: a literature review.

The current data on various aspects of Brown syndrome are limited and sporadic. This review provides a coherent and comprehensive review of basic features, etiology, classification, differential diagnosis, and different management strategies of patients with Brown syndrome. In this topical review, PubMed, Scopus, and Google Scholar search engines were searched for papers, published between 1950 and January 2023 based on the keywords of this article. The related articles were collected, summarized, categorized, assessed, concluded, and presented. Brown syndrome is identified by restricted passive and active elevation of the eye in adduction. The condition is divided into congenital and acquired causes. The clinical features result from a restricted motion of the superior oblique tendon sheath through the trochlea while trying to look up in adduction. The newest explanation of the underlying pathophysiology has been explained as the presence of a fibrotic strand in the superior oblique muscle tendon with variable insertion sites which creates various elevation deficits seen in Brown syndrome. The most common clinical features include the presence of an abnormal head posture, V-pattern strabismus, and hypotropia in the primary position. Management of Brown syndrome includes watchful observation, surgical, and non-surgical procedures. Some cases might resolve spontaneously without any intervention; however, some acquired cases might require systemic and/or intra-trochlear steroid administration to treat the underlying causes. Surgical procedures such as superior oblique tenectomy and using a silicon tendon expander are indicated in the presence of hypotropia and significant abnormal head posture in the primary position.

Ocular manifestations in Koolen–de Vries syndrome: an international study

ObjectivesKoolen–de Vries Syndrome (KdVS) is a rare multisystem neurodevelopmental disorder. Ocular manifestations, including strabismus, ptosis, and hyperopia, have been reported in KdVS patients, but detailed clinical data are limited. This study aims to investigate the already known ocular malformations and their frequency while uncovering novel ocular associations. MethodsThis was an international cross-sectional study. An anonymous questionnaire was sent to 237 KdVS patients registered in the GenIDA database. The questionnaire inquired about demographic data, ocular symptoms, findings reported by ophthalmologists, and ophthalmologic surgical interventions. The main outcome measures included ocular findings and surgical interventions. ResultsSixty-seven respondents worldwide completed the questionnaire, most (n = 53; 79%) under 18 years of age. Ophthalmologic abnormalities, noted in 79% of patients, included refractive errors (n = 35; 52.2%), strabismus (n = 23; 34.3%), amblyopia (n = 13; 19.5%), and eyelid ptosis (n = 9; 13.4%). Lacrimal disorders were present (n = 6; 9.0%), as were retinal findings (n = 7; 10.4%), including retinal hyperpigmentation or hypopigmentation (n = 4; 7.5%), Sjögren's pigment epithelial reticular dystrophy (n = 1; 1.5%), and macular chorioretinal coloboma (n = 1; 1.5%). Other manifestations included ocular surface disorders (n = 5; 7.5%), cataracts (n = 3; 4.5%), Brown syndrome (n = 1; 1.5%), glaucoma (n = 1; 1.5%), cerebral visual impairment (n = 1; 1.5%), and optic atrophy (n = 1; 1.5%). Fourteen patients (20.8%) had undergone surgical interventions. ConclusionsKdVS is associated with various ophthalmic findings, such as amblyopia, refractive errors, strabismus, and eyelid ptosis. We describe, for the first time, a high rate of nasolacrimal disorders and retinal abnormalities consisting mainly of pigmentary findings, including a rare case of Sjögren's pigment epithelial reticular dystrophy. A comprehensive ophthalmic evaluation is therefore recommended for all KdVS patients at initial diagnosis or at 4–6 months of age for diagnosed newborns.

The Frequency and Manifestations of Ocular Causes of Abnormal Head Posture

ABSTRACT Purpose To determine the frequency and manifestations of different ocular causes of abnormal head posture (AHP). Method This prospective, consecutive case series study was performed on 149 patients with ocular AHP at Farabi hospital, Iran, from February 2020 to June 2021. All patients underwent routine ophthalmic examinations. The manifestation of AHP was determined by direct observation from three viewing angles, while the patient read the smallest line on the vision chart that they could see. In front, above, and lateral gazes, observations were performed to find head tilt, head turn, and chin abnormal position, respectively. A picture with habitual AHP was taken from all patients. The amount of head tilt was measured by calculating the angle between the line that connects the lips center to the center of the eyebrows and the vertical line using the Corel Draw X7 computer software. Results The mean age of 149 patients with ocular AHP [101 (67.8%) males and 48 (32.2%) females] was 16.2 ± 12.2 (range, 2–57) years. The most common ocular sources of AHP were found to be superior oblique palsy (SOP) in 66 (44.3%) patients, 54 (36.2%) cases with Duane’s retraction syndrome (DRS), and 12 (8.1%) patients with nystagmus. Other frequent causes of ocular AHP were dissociated vertical deviation (DVD) in 5 (3.4%), A and V pattern strabismus in 3 (2.0%), and 2 cases (1.3%) in each of Brown syndrome, inferior rectus (IR) palsy, and congenital fibrosis of the extraocular muscles (CFEOM). The most common manifestations of AHP in all cases were “pure head turn” (48.3%), followed by “pure head tilt” (24.8%), “simultaneous head tilt and head turn” (20.8%), and “chin up” (6.0%). The mean head tilt among all patients with head tilt was 10.4° ± 8.9° (range, 5.0°−31.7°). Conclusion The most frequent ocular sources of AHP were SOP, DRS, and nystagmus, followed by DVD, A and V pattern strabismus, IR palsy, CFEOM, and Brown syndrome. In addition, pure head turn and pure head tilt were the most common manifestations of ocular AHP but were not always seen in the same direction or combination as previously reported with these etiologies.

Pathomorphological Findings and Infectious Diseases in Selected European Brown Hare (Lepus europaeus Pallas, 1778) Populations from Schleswig-Holstein, Germany.

In the northernmost German federal state Schleswig-Holstein, populations of European brown hares (Lepus europaeus Pallas, 1778) show diverse densities and varying courses over the years. To examine differences in pathomorphological findings and infectious diseases as possible reasons for varying population dynamics, we assessed 155 hunted hares from three locations in Schleswig-Holstein from 2016 to 2020. We investigated the association of location, year, age, and sex of animals to certain pathomorphological findings and infectious diseases. Frequent pathomorphological findings were intestinal parasites (63.9%), hepatitis (55.5%), nephritis (31.0%), steatitis (23.2%), enteritis (13.5%), and pneumonia (5.2%). Body condition differed significantly between locations, and the prevalence of pneumonia was significantly higher in females. Enteritis was not detected in 2019, when much more juveniles were sampled. Hepatitis and nephritis occurred significantly more often in 2016 and among adults. Additionally, more adults showed hepatitis with concurrent serotitre for European brown hare syndrome virus (EBHSV), while intestinal parasitosis as well as high excretion rates of coccidia were more common in juveniles. Sampled animals showed high infection rates with Eimeria spp. (96.1%), Trichostrongylus spp. (52.0%), Graphidium strigosum (41.2%), and a high seroprevalence (90.9%) for EBHSV, without severe symptoms. This study revealed a low prevalence of infectious pathogens, but a high prevalence of chronic inflammations of unknown origin in the tested brown hare populations. Overall, our results indicate a rather minor importance of infectious diseases for observed population dynamics of analysed hare populations in Schleswig-Holstein.

Recombination between non-structural and structural genes as a mechanism of selection in lagoviruses: The evolutionary dead-end of an RHDV2 isolated from European hare

The genus Lagovirus, belonging to the family Caliciviridae, emerged around the 1980s. It includes highly pathogenic species, rabbit hemorrhagic disease virus (RHDV/GI.1) and European brown hare syndrome virus (EBHSV/GII.1), which cause fatal hepatitis, and nonpathogenic viruses with enteric tropism, rabbit calicivirus (RCV/GI.3,4) and hare calicivirus (HaCV/GII.2). Lagoviruses have evolved along two independent genetic lineages: GI (RHDV and RCV) in rabbits and GII (EBHSV and HaCV) in hares. To be emphasized is that genomes of lagoviruses, like other caliciviruses, are highly conserved at RdRp-VP60 junctions, favoring intergenotypic recombination events at this point. The recombination between an RCV (genotype GI.3), donor of non-structural (NS) genes, and an unknown virus, donor of structural (S) genes, likely led to the emergence of a new lagovirus in the European rabbit, called RHDV type 2 (GI.2), identified in Europe in 2010. New RHDV2 intergenotypic recombinants isolated in rabbits in Europe and Australia originated from similar events between RHDV2 (GI.2) and RHDV (GI.1) or RCV (GI.3,4). RHDV2 (GI.2) rapidly spread worldwide, replacing RHDV and showing several lagomorph species as secondary hosts. The recombination events in RHDV2 viruses have led to a number of viruses with very different combinations of NS and S genes. Recombinant RHDV2 with NS genes from hare lineage (GII) was recently identified in the European hare. This study investigated the first RHDV2 (GI.2) identified in Italy in European hare (RHDV2_Bg12), demonstrating that it was a new virus that originated from the recombination between RHDV2, as an S-gene donor and a hare lagovirus, not yet identified but presumably nonpathogenic, as an NS gene donor. When rabbits were inoculated with RHDV2_Bg12, neither deaths nor seroconversions were recorded, demonstrating that RHDV2_Bg12 cannot infect the rabbit. Furthermore, despite intensive and continuous field surveillance, RHDV2_Bg12 has never again been identified in either hares or rabbits in Italy or elsewhere. This result showed that the host specificity of lagoviruses can depend not only on S genes, as expected until today, but potentially also on some species-specific NS gene sequences. Therefore, because RHDV2 (GI.2) infects several lagomorphs, which in turn probably harbor several specific nonpathogenic lagoviruses, the possibility of new speciation, especially in those other than rabbits, is real. RHDV2 Bg_12 demonstrated this, although the attempt apparently failed.

Атипичное косоглазие – синдром Брауна. Диагностика и хирургическое лечение

Purpose. Clarification of indications for surgical treatment of Brown syndrome, choice of the optimal type of surgery and tactics of treatment of secondary overaction of the ipsilateral inferior oblique muscle (IO). Material and methods. Authors evaluate the effectiveness of various types of the superior oblique muscle (SO) weakening procedures based on the analysis of the results of surgical treatment of 65 patients (69 eyes) with Brown syndrome. In 53 cases, tenectomy was performed, and in 16 cases, recession/prolongation of SO. Results. Tenectomy of SO is more effective in surgical treatment of Brown syndrome. In 60 out of 65 (92%) operated patients it was possible to significantly improve the mobility of the operated eye upwards. Secondary overaction of the inferior oblique muscle was eliminated in next step of surgery. Conclusions. Surgical treatment of Brown's syndrome is staged. Indications for surgical treatment are: significant head abnormal position, hypotropia in the primary gaze and in adduction, binocular vision disturbance. The SO tenectomy has provided good functional results in treatment of patients with Brown's syndrome. Key words: Brown's syndrome, incomitant strabismus, superior oblique muscle, surgical treatment, tenectomy, recession, anterior transposition

Pathological and virological insights from an outbreak of European brown hare syndrome in the Italian hare (Lepus corsicanus).

European brown hare syndrome (EBHS) is a highly contagious and fatal viral disease, mainly affecting European brown hares (Lepus europaeus). The etiological agent, EBHS virus (EBHSV), belongs to the Lagovirus genus within the Caliciviridae family. The Italian hare (Lepus corsicanus) is endemic to Central-Southern Italy and Sicily and is classified as a vulnerable species. L. corsicanus is known to be susceptible to EBHS, but virological data available is scarce due to the few cases detected so far. In this study, we describe the occurrence of EBHS in two free-ranging L. corsicanus, found dead in a protected area of Central Italy. The two hares were identified as L. corsicanus using phenotypic criteria and confirmed through mitochondrial DNA analysis. Distinctive EBHS gross lesions were observed at necropsy and confirmed by subsequent histological examination. EBHSV was detected in the livers of the two animals initially using an antigen detection ELISA, followed by an EBHSV-specific reverse transcription-PCR, thus confirming the viral infection as the probable cause of death. The EBHS viruses detected in the two hares were identical, as based on blast analysis performed for the VP60 sequences and showed 98.86% nucleotide identity and 100% amino acid identity with strain EBHSV/GER-BY/EI97.L03477/2019, isolated in Germany in 2019. Phylogenetic analysis places our virus in group B, which includes strains that emerged after the mid-1980s. This study supports previous reports of EBHS in L. corsicanus and further expands the knowledge of the pathological and virological characteristics of the etiological agent. The ability of EBHSV to cause a fatal disease in the Italian hare represents a serious threat to the conservation of this vulnerable species, especially in populations kept in enclosed protected areas.

Lagovirus infections of hares and rabbits: review of literature and epizootic situation in the World and Russia

Rabbit viral hemorrhagic disease (RHD) and European hare brown liver syndrome (EBHS) are two similar diseases affecting animals of the hare family, caused by closely related lagoviruses and manifesting as an acute and fatal form of hepatitis and thrombohemorrhagic syndrome in all organs, especially the lungs and liver. The two viruses are closely related genetically and antigenically and share approximately 76% identity. The causative agent of EBHS is a virus of genotype GII.1. Various species of hares and Florida rabbits are susceptible to it. VGBV is caused by viruses of two genotypes: RHDV-GI.1 and RHDV-GI.2. The first genotype (RHDV-GI.1) is strictly specific for rabbits. In contrast, the second (RHDV-GI.2) has a broader range of susceptible animals and affects not only hares but also common badgers and red-bellied musk deer. In addition, due to the lack of crossimmunity between RHDV-GI.1 and RHDV-GI.2 and a wide range of hosts, the second genotype displaces the first of the susceptible populations, which makes it more dangerous in epidemiological terms. The diseases have high morbidity and high mortality - up to 90%. Given the high persistence of the virus in the environment, the disease can cause severe economic damage. Disease control is effectively achieved through vaccination, general quarantine, and preventive measures. However, this only applies to VGBV types 1 and 2, for which vaccines exist. Currently, no vaccines are developed against brown liver syndrome in the European hare.