Factors associated with variability in response of diabetic macular oedema after intravitreal triamcinolone

Purpose:  To identify factors associated with variability in anatomical and functional response of diabetic macular oedema (DMO) after 4 mg of intravitreal triamcinolone acetonide (ivTA), and for recurrence of macular oedema.
Design:  Pooled analysis of individual data from two randomized controlled trials.
Methods:  This was a multicentre study involving 107 eyes with DMO administered 4 mg ivTA. Predictive factors for response to treatment were evaluated with linear regression analysis. Factors associated with time to recurrence of oedema were studied with Cox proportional hazards modelling. Main outcome measures were maximum improvement in optical coherence tomography (OCT)-measured central foveal thickness (CFT) and best-corrected visual acuity (BCVA), final CFT and BCVA at 12 months and time to oedema recurrence.
Results:  Greater reduction of retinal thickening occurred in eyes with worse baseline thickening ( P  < 0.001). There was also greater improvement of visual acuity in eyes with poorer preoperative BCVA levels ( P  < 0.001). Age, duration of oedema and previous macular laser treatment had no significant effect on maximal BCVA or CFT improvement. Eyes given 4 mg triamcinolone alone were more likely to develop recurrence of oedema at 12 months than those given a combination of 4 mg triamcinolone plus sequential laser (hazard ratio 2.60 [95% confidence interval: 1.45–4.67]).
Conclusion:  Baseline OCT-measured retinal thickening and BCVA are important predictors of maximal anatomical and functional response of DMO to ivTA, respectively. Combination treatment strategy using sequential laser therapy may have a role in delaying recurrence of oedema after triamcinolone.     

The comorbid association of migraine with osteoarthritis and hypertension: complement C3F and Berkson's bias

Migraine is known to have a major genetic component and has been associated with a wide variety of comorbid disorders including arthritis and heart disease. Since migraine and some of its comorbid disorders involve inflammation, complement C3, a protein involved in acute inflammation, was selected for analysis as a candidate gene in an ongoing study of the genetic basis of migraine. Polymorphism frequencies for complement C3F (0.19) and C3S (0.81) in a sample of 137 unrelated migraineurs were found to be consistent with a control group as well as previous population studies, indicating that this common polymorphism has no association with migraine susceptibility. However, C3F positive individuals with migraine were found to have an increased incidence of osteoarthritis (Chi square = 10.06; p < 0.0008) and hypertension (Chi square = 5.18; p < 0.01). Therefore, the data in the present study indicate that certain migraine comorbidities that have been reported in the literature may result from Berkson's bias as opposed to a shared pathophysiological variation in the C3 gene.     

Intestinal angina: percutaneous transluminal angioplasty of the celiac and superior mesenteric arteries

Percutaneous transluminal angioplasty (PTA) was performed in ten patients with chronic ischemia of the mesenteric arteries and stenoses of the celiac artery and/or the superior mesenteric artery (SMA). PTA was performed on 14 occasions, with attempted dilation of 19 arteries. PTA was technically unsuccessful in two patients. Seventeen of 19 arteries (90%) were successfully dilated in eight patients, resulting in relief of symptoms that lasted from 6 to 24 months. Symptoms recurred in five patients, and redilation in three of them relieved the symptoms. Three patients, one of them following redilation, remained asymptomatic 7-9 months following PTA. An asymptomatic intimal dissection of the SMA was the only complication attributable to the procedure. PTA of celiac and SMA stenoses is an alternative to surgical revascularization and can be repeated if symptoms recur.     

Regulation of hematopoiesis: helper and suppressor influences of the thymus

Thymocytes from normal mice strains as well as from genetically determined stem cell defective W/Wv anemic mice were cocultured with syngeneic (or congeneic) bone marrow cells. We assayed these cocultures for the proliferation of erythroid progenitor cell types (BFU-E and CFU- E) using the plasma clot technique. Results indicate that when concentrations of thymocytes were lower than bone marrow cells, significant suppression of erythroid growth was observed. However, when the concentration of thymocytes exceeded that of the bone marrow cells in culture (greater than 1:1), significant enhancement of erythroid growth was demonstrated. The W/Wv anemic bone marrow appears to respond to this interaction by enhancement at all concentrations of added normal thymocytes. The regulatory functions observed can be diminished by treatment of the thymocytes in vitro with anti-theta serum plus complement. Thus, we establish regulatory functions for anti-theta- sensitive regulatory cells (TSRC) with both positive (enhancement) and negative (suppression) components.