Acadenic Research Services at the Medical Sciences Library, Faculty of Medical Sciences Library, The University of the West Indies, St. Augustine

To profile academic library services at the Medical Sciences Library, The University of the West Indies, St. Augustine Trinidad and Tobago, highlighting reseources and initiatives that support the Faculty of Medical Sciences curriculum, research, and scholarly communication. To outline the resources and services available at the Medical Sciences Library to support teaching and learning with a focus on research.

Bidirectional modulation of anxiety-related and social behaviors by amygdala projections to the medial prefrontal cortex.

The basolateral amygdala (BLA) and the medial prefrontal cortex (mPFC) modulate anxiety and social behaviors. It remains to be elucidated, however, whether direct projections from the BLA to the mPFC play a functional role in these behaviors. We used optogenetic approaches in behaving mice to either activate or inhibit BLA inputs to the mPFC during behavioral assays that assess anxiety-like behavior and social interaction. Channelrhodopsin-2 (ChR2)-mediated activation of BLA inputs to the mPFC produced anxiogenic effects in the elevated plus maze and open field test, whereas halorhodopsin (NpHR)-mediated inhibition produced anxiolytic effects. Furthermore, activation of the BLA-mPFC pathway reduced social interaction in the resident-intruder test, whereas inhibition facilitated social interaction. These results establish a causal relationship between activity in the BLA-mPFC pathway and the bidirectional modulation of anxiety-related and social behaviors.

Detection of Yersinia enterocolitica in food: an overview.

Yersinia enterocolitica is a gastrointestinal pathogen which causes yersiniosis, an illness characterized by diarrhea, ileitis, and mesenteric lymphadenitis. Y. enterocolitica is transmitted via the feco-oral route by the consumption of contaminated food or water. Several phenotypic and genotypic methods have been developed to reliably detect Y. enterocolitica in food. However, the source of infection of many recently reported foodborne outbreaks remains obscure. The detection of this pathogen in food is a challenging task, since it shares similarities with other enteric bacteria. The presence of other microorganisms in the food samples makes it even more difficult to identify this slow-growing pathogen. Therefore, the present-day emphasis is on the development of sensitive, easily automated methods suitable for in-situ detection, allowing quick and cost-effective characterization of food samples. This review summarizes and compares the currently available cultural, immunological, and molecular methods, particularly in relation to their specific merits or demerits when implemented for the detection of Y. enterocolitica in food.

Vitrectomy with silicone oil infusion in severe diabetic retinopathy.

AIMS: To determine the results of pars plana vitrectomy (PPV) and silicone oil infusion (SOI) in severe proliferative diabetic retinopathy (PDR). METHODS: The records of 23 eyes (21 patients: 12 males, nine females) with PDR who had undergone PPV and SOI were reviewed retrospectively. RESULTS: Average follow up was 5.4 months (range 1-25). Surgical indications were tractional retinal detachment (TRD) (17.4%), traction-rhegmatogenous retinal detachment (TRRD) (8.7%), TRD with vitreous haemorrhage (VH) (48%), TRD with neovascular glaucoma (NVG) (8.6%), TRD with fibrinoid syndrome (FS) (17.3%). With one operation, the retinal reattachment rate was 17/23 (74%). Among these 23 eyes, 11 (48%) had previously failed vitrectomy, and the retina was attached in 8/11 (73%) with a single procedure. With additional surgery employing PPV and SOI, the final reattachment rate was 20/23 (87%). The only cases with intraocular pressure <5 mm Hg had retinal detachment. Postoperative visual acuity (VA) improved in 10 eyes (44%), was unchanged in three (12%), and decreased in 10 eyes (44%). CONCLUSION: SO tamponade is useful in severely diseased eyes with PDR, even in the presence of rubeosis iridis (RI) and NVG, FS, or in cases with previously failed vitrectomy, especially in the presence of RI.

Use of viscodissection and silicone oil in vitrectomy for severe diabetic retinopathy.

Improvement in surgical techniques has led to improved anatomic and functional success rates following surgery for severe complications of proliferative diabetic retinopathy (PDR). We compared the anatomic and functional outcomes of surgery in a non-randomized, consecutive case series of patients with severe PDR. We found that viscodissection using Healon provides outcomes comparable to conventional pick and scissors dissection. We also found that adjunctive use of silicone oil can salvage selected cases with particularly severe manifestations of PDR (e.g., the fibrinoid syndrome). With proper selection of patients and techniques, the anatomic success rate can exceed 80% even in the most severe cases. The goal of this paper is to show the applicability of using viscodissection and silicone oil infusion during vitrectomy in eyes with severe PDR.

Exudative retinal detachment in relapsing polychondritis : case report and literature review.

OBJECTIVE: To report the atypical ocular symptoms (arterialized conjunctival vessels, exudative retinal detachment) that can be the presenting manifestations of relapsing polychondritis. DESIGN: Observational case report and literature review. METHODS: A complete ocular and systemic evaluation was performed on a patient with relapsing polychondritis and exudative retinal detachment. MAIN OUTCOME MEASURES: Retinal, choroidal, and scleral findings. RESULTS: A 73-year-old man with relapsing polychondritis presented with a unilateral large bullous exudative retinal detachment and marked choroidal and scleral thickening bilaterally. CONCLUSIONS: Ophthalmologists should consider relapsing polychondritis in the differential diagnosis of exudative retinal detachment. A combination of echographic and laboratory findings can assist in the accurate diagnosis of this rare condition.

Rifabutin-associated hypopyon uveitis in human immunodeficiency virus-negative immunocompetent individuals.

OBJECTIVE: To report the occurrence of rifabutin-associated hypopyon uveitis in human immunodeficiency virus (HIV)-negative immunocompetent individuals. DESIGN: Retrospective case series. PARTICIPANTS: Three HIV-negative subjects on rifabutin and clarithromycin for Mycobacterium avium complex infections with hypopyon uveitis are described. One subject was iatrogenically immunosuppressed because of a prior lung transplant. Two subjects had no known immunosuppressive conditions. INTERVENTION: Topical and regional steroid therapy. Discontinuation of rifabutin was required in two subjects. MAIN OUTCOME MEASURES: Visual acuity, resolution of hypopyon, anterior uveitis, and vitreitis. RESULTS: All subjects had resolution of hypopyon after therapy, two within 24 hours of beginning topical steroids. Vitreitis resolved with the discontinuation of rifabutin in two subjects. Chronic low-grade anterior uveitis and vitreitis were observed in the remaining subject, whose rifabutin dose was lowered but not discontinued because of active Mycobacterium avium complex osteomyelitis. CONCLUSIONS: Rifabutin-associated uveitis is well described in HIV-positive individuals, but it has been reported only once in an HIV-negative individual. We report two cases of hypopyon uveitis in immunocompetent individuals and one case in an immunosuppressed HIV-negative individual. All three subjects were receiving concurrent rifabutin and clarithromycin. Awareness that this entity can occur in HIV negative and nonimmunosuppressed individuals and that it can mimic infectious endophthalmitis may spare the subject from an invasive workup of systemic infection.

Central retinal vein occlusion: report of two familial cases.

The authors report a 46-year-old father and 17-year-old son who each presented with unilateral central retinal vein occlusion (CRVO) and bilateral abnormalities of retinal vascular perfusion. The son presented with a nonperfused CRVO in the left eye, developed traction-rhegmatogenous retinal detachment treated with vitreous surgery, and developed prolonged arteriovenous filling in the retina of the fellow eye. The father presented with progressive CRVO in the right eye, developed choroido-vitreal neovascularization following laser treatment to create a chorioretinal anastomosis, underwent vitrectomy for retinal detachment and vitreous hemorrhage in that eye, and developed prolonged arm-eye and retinal arteriovenous circulation times in the fellow eye. An extensive evaluation (including hematological studies and imaging of the major vessels of the neck) failed to reveal a predisposing cause in either patient although echocardiography disclosed a mitral valve thrombus in the father. After institution of coumadin therapy, the circulatory parameters in the fellow eye of each patient improved.

Central retinal vein occlusion: review of management.

Central retinal vein occlusion is usually a disease of the elderly and is often associated with systemic vascular disease, e.g., hypertension, diabetes mellitus, arteriosclerotic vascular disease. Younger patients, especially those less than 45 years of age, with retinal vein occlusion should be evaluated carefully for the possibility of an underlying thrombotic tendency. The authors describe the ocular manifestations, pathogenesis, associated conditions, patient evaluation, and treatment of patients with central retinal vein occlusion.