Long-term retinal toxicity of intravitreal commercially available preserved triamcinolone acetonide (Kenalog) in rabbit eyes

PURPOSE: To investigate whether intravitreal Kenalog (IVTK; Bristol Meyers Squibb Company, Princeton, NJ) produces histologic or electroretinographic changes in the rabbit retina up to 3 months after injection. METHODS: Ten Dutch-belted rabbits were injected with 4 mg/0.1 mL Kenalog in one eye and 0.1 mL physiologic salt solution (PSS) in the fellow eye. Simultaneous bilateral dark-adapted electroretinography was performed 2 weeks and 12 weeks after injection in 10 and 6 rabbits, respectively. Saturated a-wave amplitude, maximal scotopic b-wave amplitude, and individual a-wave and b-wave amplitudes of IVTK-injected and control eyes were compared at 2 and 12 weeks after injection. Light microscopy was performed on both eyes of three animals 3 months after injection. Immunohistochemistry was performed with antibodies recognizing vimentin and human alveolar macrophage (HAM)-56, markers of glial cells and macrophages, respectively. RESULTS: No significant difference was observed in the saturated a-wave or maximal scotopic b-wave amplitudes between the PSS-injected eyes and the IVTK-injected eyes at 2 weeks (P = 0.95 and P = 0.56, respectively) and 12 weeks (P = 0.82 and P = 0.17) after injection. Light microscopy and immunohistochemistry disclosed only rare macrophages in the vitreous of IVTK-injected eyes. Retinal layers, retinal pigment epithelium, and choriocapillaris in treatment and control eyes were unremarkable. CONCLUSIONS: No demonstrable electroretinographic or histologic changes occurred to suggest immediate or delayed widespread retinal toxicity of IVTK.     

Inhibition of experimental corneal neovascularisation by bevacizumab (Avastin)

AIM: To evaluate the effect of topically administered bevacizumab (Avastin) on experimental corneal neovascularisation in rats. METHODS: Silver nitrate sticks (75% silver nitrate, 25% potassium nitrate) were used to perform chemical cauterisation on the corneas of 16 eyes from 16 male Long Evans rats. For the following 7 days, the 10 eyes in the treatment group were instilled with bevacizumab 4 mg/ml drops twice daily, whereas the 6 eyes in the control group received placebo (normal saline drops twice daily). Digital photographs of the cornea were analysed to determine the area of cornea covered by neovascularisation as a percentage of the total corneal area. RESULTS: In the bevacizumab-treated eyes, neovascularisation covered, on average, 38.2% (15.5%) (mean (SD)) of the corneal surface compared with 63.5% (5.0%) in the control group (p<0.02, Mann-Whitney U test). CONCLUSION: Topically administered bevacizumab (Avastin) at a concentration of 4 mg/ml limits corneal neovascularisation following chemical injury in the male Long Evans rat model.     

Angiomyxoma of umbilical cord

A rare angiomyxoma of umbilica cord occurred in a male infant. The presence of such a tumor with its vascular component arising from a hypoplastic umbilical artery supports the hypothesis that the lesions arose through improper placental vascularization.     

The common 'thermolabile' variant of methylene tetrahydrofolate reductase is a major determinant of mild hyperhomocysteinaemia

Mild hyperhomocysteinaemia is a major risk factor for vascular disease and neural tube defects (NTDs), conferring an approximately three-fold relative risk for each condition. It has several possible causes: heterozygosity for rare loss of function mutations in the genes for 5,10-methylene tetrahydrofolate reductase (MTHFR) or cystathionine-&bgr;-synthase (CBS); dietary insufficiency of vitamin co-factors B6, B12 or folates; or homozygosity for a common 'thermolabile' mutation in the MTHFR gene which has also been associated with vascular disease and NTDs. We quantified the contribution of the thermolabile mutation to the hyperhomocysteinaemic phenotype in a working male population (625 individuals). Serum folate and vitamin B12 concentrations were also measured and their relationship with homocysteine status and MTHFR genotype assessed. The homozygous thermolabile genotype occurred in 48.4, 35.5, and 23.4% for the top 5, 10 and 20% of individuals repectively) ranked by plasma homocysteine levels, compared with a frequency of 11.5% in the study population as a whole establishing that the mutation is a major determinant of homocystein levels at the upper end of the range. Serum folate concentrations also varied with genotype, being lowest in thermolabile homozygotes. The MTHFR thermolabile genotype should be considered when population studies are designed to determine the effective homocysteine-lowering dose of dietary folate supplements, and when prophylactic doses of folate are recommended for individuals.      

HIV/AIDS related mortality among adult medical patients in a tertiary health institution in South–South,Nigeria

ObjectiveTo determine the causes of death among human immunodeficiency virus/acquired immunodeficiency syndrome (HIV/AIDS) patients as a step to planning strategies to improve mortality from this condition.MethodsThis study retrospectively analyzed the mortality pattern of adult HIV/AIDS patients in the University of Calabar Teaching Hospital from January 2005 to December 2007. The data were obtained from sexually transmitted infection/acquired immunodeficiency syndrome (STI/AIDS) clinic register, admissions and discharge/death registers as well as the patients' case records and the hospitals monthly mortality reviews. Information obtained included age, sex, diagnosis and cause(s) of death. The causes of death considered were the direct causes of death, since the originating antecedent cause of death is the same in all the patients, in this case, HIV/AIDS. Data was analysed using Epi Info 2002.ResultsThe total number of mortalities during the study period was 350,100 were HIV positive representing 28.6% of all deaths. While advanced HIV/AIDS disease was the leading cause of death in our study representing 27.0%, tuberculosis was the single leading cause of deaths in HIV/AIDS patients constituting about 24.0% of deaths. This was followed by sepsis and septicaemia (13.0%), meningitis and encephalitis, and anaemia accounting for 11.0%, while respiratory diseases constituted 5.0% of the mortality burden. The highest number of deaths occurred in those aged between 21–50 years (82.0%).ConclusionsThe study has shown that HIV/AIDS is a major cause of morbidity and mortality in our hospital. The causes of death reflect the varied spectrum of infection and other forms of organ involvement that affect HIV/AIDS patients. The present dismal situation of adult patients living with HIV/AIDS calls for enhanced strategies to decrease the mortality trend observed in Nigeria and sub-Saharan Africa.     

Patient-Related and Angiographic Predictors of Restenosis After Excimer Laser Coronary Angioplasty

Excimer laser coronary angioplasty (ELCA) is a useful technique for the treatment of selected complex coronary lesions. However, this technology has been limited by significant restenosis and, to date, predictors of restenosis after use of this device are not clearly defined. In order to determine predictors of restenosis after ELCA, 43 lesions presenting with restenosis (> 50% diameter stenosis) at angiographic follow-up were compared to 46 lesions without restenosis, based on patient-related, qualitative and quantitative angiographic parameters. Univariate analysis revealed 9 variables with at least a borderline (p < 0.15) significant relation to restenosis: (1) age (p = 0.0759), (2) proximal left anterior descending site (p = 0.074), (3) presence of a restenotic lesion (p = 0.104), (4) lesion length (p = 0.0034), (5) reference diameter of the treated vessel (p = 0.0076), (6) post laser minimal luminal diameter (MLD) (p = 0.1160), (7) post-procedural MLD (p = 0.0001), (8) post-procedural stenosis (p = 0.0250) and (9) total procedural gain (p = 0.0051). After entering stepwise logistic regression analysis, only 3 variables emerged as independent predictors of restenosis: treatment of a restenotic lesion (p = 0.0255), lesion length (p = 0.0291) and post-procedural MLD (p = 0.0007). Based on these data, we conclude that post-procedural MLD is the most important predictor of restenosis after ELCA. Lesion length and the treatment of restenotic lesions are also independently associated with an increased risk of restenosis after ELCA. Therefore, achieving the best possible luminal result at the time of the first intervention should be the goal of the procedure, especially when treating high restenosis risk lesions.