Improved metabolic control results in better myogenic response of retinal arterioles in patients with diabetes mellitus type 1

AIMS

The retina is protected against high blood pressure by the myogenic constriction of arterioles (the Bayliss effect). Hyperglycemia impairs this retinal autoregulation by endothelial dysfunction. The purpose of this prospective pilot study was to test whether improved metabolic control results in a measurable effect on the myogenic response of human retinal arterioles to acute increases in blood pressure.

METHODS

The Bayliss effect was measured in 25 patients with diabetes mellitus by the Retinal Vessel Analyzer (RVA), both before and after participation in a treatment and teaching program for intensified insulin therapy with the goal of improved metabolic control. After 12 months, 17 subjects still fulfilled the inclusion criteria and underwent an identical measurement. The Wilcoxon test was used for statistical analysis.

RESULTS

During the first session, a rise in mean arterial pressure (MAP) of 20.2 +/- 8.6 mm Hg was followed by an arterial vasoconstriction of -3.2 +/- 2.9%. The educational program resulted in a significant drop in Hb(A1c) levels (9.4 +/- 1.9 vs. 6.9 +/- 0.98%). Eight subjects did not meet the inclusion criteria after 12 months. Seventeen subjects were remeasured and a rise in blood pressure of 19.5 +/- 9.9 mm Hg in the second session was associated with a significantly improved arterial vasoconstriction of -5.9 +/- 2.7% (session I vs. session II, p = 0.006).

CONCLUSION

The myogenic response of the arterial wall in human retinal arterioles was significantly improved by the therapeutic intervention.

Isotope and temperature effects in liquid water probed by x-ray absorption and resonant x-ray emission spectroscopy

High-resolution x-ray absorption and emission spectra of liquid water exhibit a strong isotope effect. Further, the emission spectra show a splitting of the 1b1 emission line, a weak temperature effect, and a pronounced excitation-energy dependence. They can be described as a superposition of two independent contributions. By comparing with gas phase, ice, and NaOH/NaOD, we propose that the two components are governed by the initial state hydrogen bonding configuration and ultrafast dissociation on the time scale of the O 1s core hole decay.

Isotope and temperature effects in liquid water probed by x-ray absorption and resonant x-ray emission spectroscopy

High-resolution x-ray absorption and emission spectra of liquid water exhibit a strong isotope effect. Further, the emission spectra show a splitting of the 1b1 emission line, a weak temperature effect, and a pronounced excitation-energy dependence. They can be described as a superposition of two independent contributions. By comparing with gas phase, ice, and NaOH/NaOD, we propose that the two components are governed by the initial state hydrogen bonding configuration and ultrafast dissociation on the time scale of the O 1s core hole decay.

[Prevalence of diabetic retinopathy. Check-up program of a public health insurance company in Germany 2002-2004]

OBJECTIVES

Population based studies have reported a prevalence of diabetic retinopathy (DR) at the time of diagnosis in up to 30% of the patients. In the context of a general diabetes check-up program (so called "Diabetes-TUV"), the prevalence of diabetic retinopathy in Germany was examined in all diabetes patients insured in a public health insurance company.

METHODS

Patients were screened in the offices of 181 ophthalmologists according to a standardized protocol formulated by Prof. Kroll, Marburg. A total of 6,500 sheets were analysed out of which 14.5% were multiply documented. The latest protocols of 5,596 patients were evaluated; the mean age was 64.7 years with an average duration of diabetes of 10.2 years.

RESULTS

Some 86.3% of the eyes examined had no DR, in 3.1% no evaluation was possible. Of the patients checked, 10.6% had DR. Mild/moderate DR was reported in 8.3%, severe non-proliferative DR in 1.7% and proliferative DR in 0.5%. Macular edema was reported in 0.85% of cases, vitreous hemorrhage in 0.2%. There was 0.1% iris neovascularisation and 0.1% retinal detachment. Visual impairment due to cataract or secondary cataract was found in 25.2% of patients with an 8.3% pseudophakia rate.

CONCLUSION

Documentation of the eye examination in the diabetes check-up program was good. The 10.6% prevalence of DR in Germany, even after long standing diabetes, seems to be lower than in earlier population based studies in the US or UK. The data reported here could be an indication of better diabetes care in Germany. However, not all patients were examined with dilated pupils, and in the case of severe changes, the ophthalmologist might have decided not to fill in the report form and to have chosen another form of communication.

Prognostic role of VEGF, EGFR, COX-2, cERB-b2 and ER-alpha in stage 1 non-small cell lung cancers

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Introduction: Five-year survival rates for pathologic stage one NSCLC are between 57–67%. We looked at VEGF, EGFR, COX-2, cERB-b2 and ER-a in relationship to predicting recurrence. Methods: Tumors from 65 consecutive patients with stage I NSCLC were included. After marking representative areas on the slides, tissue microarrays were prepared and stained immunohistochemically using commercially available antibodies. The scoring was done by the pathologist and the principal investigator and is calculated as the product of staining intensity, the percentage of positively stained tumor cells and extent of membrane involvement. Results: 27 (42%) males/38 (58%) females. 75% stage IA/25% stage IB. Median smoking history was 40 pack-years (range 0–160pyr). 77% adenocarcinomas/23% squamous cell carcinomas. 19 (29%) patients had a recurrence of which 14 (74%) recurred locally and 5 (26.%) recurred at distant sites. The most common site of recurrence was the lung. Median time to recurrence was 30 months (range 4–97 mos). Scores for the molecular markers are reported in table 1 . Logistic regression of all the variables on multivariate analysis showed that VEGF scores predicted recurrence (p=0.021, Odds Ratio of 1.021). Scores of >200 for VEGF were even more discriminatory. (p =0.034, Odds Ratio of 7.22). The rate of recurrence in this subgroup of patients was 39.5% as opposed to a rate of 14.8% among those with scores of less than 200. EGFR, COX-2, cERB-B2 and ER alpha were not found to be significant predictors of recurrence. Table 1 . Univariate analysis: Conclusion: VEGF scores predict risk of recurrence in stage I Non Small Cell Lung Cancers. We propose the use of high scores of VEGF, in Stage I Non Small Cell Carcinoma using immunohistochemistry to select those patients who are likely to recur.

No significant financial relationships to disclose.

[Table: see text]

Presbyopietherapie mit Femtosekundenlaser

Presbyopia is by far the most common refractive error worldwide, with no permanent therapeutic option available. All efforts to restore accommodation by the use of surgery have not led to a generally accepted therapy. However, there is evidence from an animal model that the use of a femtosecond (fs) laser might influence the modulus of elasticity in the lens. Fs-laser impulses can create intralenticular disruption in animal eyes as well as human cadaver lenses and improve elasticity. The concept of treating presbyopia with fs-laser requires a new, complex theory combining the optical and the mechanical aspects of accommodation in the eye. Diagnostic tools for measuring optical change in power and geometrical modification as the eye views from far to near are needed to obtain objective clinical data. A non-invasive treatment of presbyopia to restore accommodation might be possible in the future.