Division of viscoelastic substances for ophthalmological surgery

Individual properties of a viscoelastic substance for ophthalmologic applications are intimately tied to its chemical and rheologic characteristics. Independent comparative data for vicoelastic substances are not readily available or interpretable. Material and methods: Twenty-six different commercially available viscoelastic substances were investigated using the Advanced Rheometric Expansion System and the Rheometric Scientific 800 device to analyze elastic and viscous modulus, complex viscosity (dynamic frequency dependance) and viscosity at the zero shear rate by extrapolation using the Ellis fit. Results: Viscosity (cps) at zero shear rate (s^–1, mean of six different samples): Sodium hyaluronate products: Amivisc Plus: 128; AMO Vitrax: 41; Biolon: 243; Dispasan: 130; Dispasan Plus: 782; Healon: 243; Healon GV: 2451; Healon 5: 5525; Microvisc (Morcher Oil): 1162; Microvisc Plus: 3663; Morcher Oil: 1253; Provisc: 207; Rayvisc: 78; Viscoat: 58; Viscorneal (Allervisc): 733; Viscorneal Plus (Allervisc Plus): 1176; Visko: 206; Visko Plus: 1683. Hydroxypropylmethylcellulose (HPMC) products: Acrivisc: 7; Adatocel: 8; Coatel: 6; HPMC Ophthal H: 94; HPMC Ophthal L: 7; Ocucoat: 6; PeHa-Visko: 5; Visco Shield: 60. Conclusion: Sodium hyaluronate as well as HPMC viscoelastic substances demonstrated remarkable differences in rheological properties from each other. In some cases, the results of this independent investigation differed from the values provided by the companies. A new division of commercially available viscoelastic substances into subgroups is presented, which provides a scientific base for various practical viscosurgical aspects. These real rheologic properties of each substance allow the ophthalmic surgeon to choose the viscoelastic substance that is most suitable for the surgical situation.     

Nonsteroidal drugs for the treatment of noninfectious posterior and intermediate uveitis

PURPOSE OF REVIEW: This review summarizes current nonsteroidal drug therapies for noninfectious posterior and intermediate uveitis. RECENT FINDINGS: Continuing evidence shows that second-line agents including antimetabolites, T-cell inhibitors and alkylating agents, are effective in many patients, allowing reduction in steroid dose and preservation of visual function. There is an increased use of mycophenolate mofetil. Biologic therapies, including the antitumour necrosis factor-alpha agents and interferons, have demonstrated a high degree of efficacy in controlling uveitis refractory to immunosuppressants. SUMMARY: There are an increasing number of treatment options. As the vast majority of published studies in uveitis are case series or nonrandomized trials, there remains a lack of level 1 evidence to guide the choice and duration of therapy. Standard initial treatment for steroid-resistant disease is to add a single immunosuppressant to the regime, with additional agents being substituted or added as required. Combination of two immunosuppressants in addition to steroids may be indicated especially in chronic uveitis. High cost and limited long-term experience with biologic agents have restricted their use to uveitis refractory to immunosuppressants, but evidence suggests a potential therapeutic role earlier in Bechet's disease.     

Long-term fluvastatin reduces the hazardous effect of renal impairment on four-year atherosclerotic outcomes (a LIPS substudy)

Mild renal impairment is an important risk factor for late cardiovascular complications. This substudy of the Lescol Intervention Prevention Study (LIPS) assessed the effect of fluvastatin on outcome of patients who had renal dysfunction and those who did not. Complete data for creatinine clearance calculation (Cockcroft-Gault formula) were available for 1,558 patients (92.9% of the LIPS population). Patients were randomized to fluvastatin or placebo after successful completion of a first percutaneous coronary intervention. Follow-up time was 3 to 4 years. The effect of baseline creatinine clearance on coronary atherosclerotic events (cardiac death, nonfatal myocardial infarction, and coronary reinterventions not related to restenosis) was evaluated. Baseline creatinine clearance (logarithmic transformation) was inversely associated with an incidence of adverse events among patients who received placebo (hazard ratio 0.99, 95% confidence interval 0.982 to 0.998, p = 0.01). However, no association was noted between creatinine clearance and the incidence of adverse events among patients who received fluvastatin (hazard ratio 1.0, 95% confidence interval 0.99 to 1.0, p = 0.63). No further deterioration in creatinine clearance was observed during follow-up, regardless of baseline renal function or allocated treatment. Occurrence of adverse events was not related to changes in renal function during follow-up. Fluvastatin therapy markedly decreased the risk of coronary atherosclerotic events after percutaneous intervention in patients who had lower values of creatinine clearance at baseline. The benefit of fluvastatin was unrelated to any effect on renal function.     

Antiphospholipid antibodies and platelets

The most distinguishing serologic feature of antiphospholipid syndrome (APS) is the moderate to high blood titers of antiphospholipid-binding antibodies (aPL). The pathogenic mechanisms of APS are poorly understood, but may occur as a result of the interaction between anticardiolipin antibodies (aCL), beta-2 glycoprotein-I (β₂GP-I) (the aCL cofactor) and blood platelets. However, the relationship between aCL/β₂GP-I complexes and platelet aggregation has yet to be clearly elucidated. This article will briefly review aPL, β₂GP-I and platelet physiology with respect to recent hypotheses relating aCL/β₂GP-I complexes and platelets.     

Blood Pressure Variations During a Working Day at Age 28: Effects of Different Types of Work and Blood Pressure Level at Age 18

Abstract

During an ordinary work day blood pressure was self-monitored once every hour in two samples of asymptomatic nonmedicating 28-year-old men. They were selected on the basis of previous compulsory blood pressure recordings made at the age of 18 when they had been drafted for military service. Subjects in the ?original hypertensive sample” with ?strain” occupations (hectic and uncontrollable, such as waiter, driver and cook) had more marked elevations of systolic blood pressure during work hours than other subjects.     

Developing a behavioral model for mobile phone-based diabetes interventions

Objectives

Behavioral models for mobile phone-based diabetes interventions are lacking. This study explores the potential mechanisms by which a text message-based diabetes program affected self-management among African-Americans.

Methods

We conducted in-depth, individual interviews among 18 African-American patients with type 2 diabetes who completed a 4-week text message-based diabetes program. Each interview was audio-taped, transcribed verbatim, and imported into Atlas.ti software. Coding was done iteratively. Emergent themes were mapped onto existing behavioral constructs and then used to develop a novel behavioral model for mobile phone-based diabetes self-management programs.

Results

The effects of the text message-based program went beyond automated reminders. The constant, daily communications reduced denial of diabetes and reinforced the importance of self-management (Rosenstock Health Belief Model). Responding positively to questions about self-management increased mastery experience (Bandura Self-Efficacy). Most surprisingly, participants perceived the automated program as a “friend” and “support group” that monitored and supported their self-management behaviors (Barrera Social Support).

Conclusions

A mobile phone-based diabetes program affected self-management through multiple behavioral constructs including health beliefs, self-efficacy, and social support.

Practice implications

Disease management programs that utilize mobile technologies should be designed to leverage existing models of behavior change and can address barriers to self-management associated with health disparities.