[Treatment-refractory anaemia in a 35-year-old heart transplant recipient on chronic hemodialysis]

Es wird über einen 35-jährigen Dialysepatienten nach Herztransplantation berichtet, der eine „pure red cell aplasia“ aufwies. Serologisch fand sich ein positiver Parvovirus-B19-Immunglobulin-M-Titer, im Direktnachweis mittels Polymerase-Kettenreaktion zeigten sich 80 Mrd. IU/ml. In der zytologischen Untersuchung des Knochenmarks gelang der Nachweis von Riesenproerythroblasten, pathognomonisch für eine Parvovirus-B19-Infektion. Zur Therapie erfolgte die hoch dosierte Gabe von Immunglobulinen über 5 Tage. Bei Wiedervorstellung nach vier Wochen zeigte sich die Anämie deutlich gebessert. Bei Patienten nach Organtransplantation mit hyporegenerativer Anämie sollte eine Parvovirus-B19-Infektion stets ausgeschlossen werden.

Dual Pharmacological Inhibition of Angiopoietin-2 and VEGF-A in Murine Experimental Sepsis

BACKGROUND

Sepsis is a pathological host response to infection leading to vascular barrier breakdown due to elevated levels of angiopoietin-2 (Angpt-2) and vascular endothelial growth factor-A (VEGF-A). Here, we tested a novel heterodimeric bispecific monoclonal IgG1-cross antibody of Angpt-2 and VEGF - termed "A2V."

METHODS

Cecal ligation and puncture was used to induce murine polymicrobial sepsis. Organs and blood were harvested for fluorescence immunohistochemistry and RT-PCR, and survival was recorded. In vitro endothelial cells were stimulated with plasma from septic shock patients costimulated with A2V or IgG antibody followed by immunocytochemistry and real-time transendothelial electrical resistance.

RESULTS

Septic mice treated with A2V had a reduced induction of the endothelial adhesion molecule ICAM-1, leading to a trend towards less transmigration of inflammatory cells (A2V: 42.2 ± 1.0 vs. IgG 48.5 ± 1.7 Gr-1+ cells/HPF, p = 0.08) and reduced tissue levels of inflammatory cytokines (e.g., IL-6 mRNA: A2V 9.4 ± 3.2 vs. IgG 83.9 ± 36.7-fold over control, p = 0.03). Endothelial permeability was improved in vivo and in vitro in stimulated endothelial cells with septic plasma. Survival was improved by 38% (p = 0.02).

CONCLUSION

Dual inhibition of Angpt-2 and VEGF-A improves murine sepsis morbidity and mortality, making it a potential therapeutic against vascular barrier breakdown.

Flunarizine suppresses endothelial Angiopoietin-2 in a calcium - dependent fashion in sepsis

Sepsis is a life-threatening organ dysfunction caused by a dysregulated host response to an infection leading to systemic inflammation and endothelial barrier breakdown. The vascular-destabilizing factor Angiopoietin-2 (Angpt-2) has been implicated in these processes in humans. Here we screened in an unbiased approach FDA-approved compounds with respect to Angpt-2 suppression in endothelial cells (ECs) in vitro. We identified Flunarizine – a well-known anti-migraine calcium channel (CC) blocker – being able to diminish intracellular Angpt-2 protein in a time- and dose-dependent fashion thereby indirectly reducing the released protein. Moreover, Flunarizine protected ECs from TNFα-induced increase in Angpt-2 transcription and vascular barrier breakdown. Mechanistically, we could exclude canonical Tie2 signalling being responsible but found that three structurally distinct T-type - but not L-type - CC blockers can suppress Angpt-2. Most importantly, experimental increase in intracellular calcium abolished Flunarizine’s effect. Flunarizine was also able to block the injurious increase of Angpt-2 in murine endotoxemia in vivo. This resulted in reduced pulmonary adhesion molecule expression (intercellular adhesion molecule-1) and tissue infiltration of inflammatory cells (Gr-1). Our finding could have therapeutic implications as side effects of Flunarizine are low and specific sepsis therapeutics that target the dysregulated host response are highly desirable.

Comparison of the SRK II formula and other second generation formulas

A simple modification of the SRK formula was developed for use with extreme axial length cases (short and long eyes) to maximize prediction accuracy in these groups. For "average" eyes (over 75% of all cases), SRK needed no modifications to maintain maximum predictive accuracy. The new, modified SRK formula (SRK II) was compared with current second generation formulas and the Binkhorst formula. The SRK II formula, while maintaining the simplicity and ease of the SRK, was comparable to and in some cases superior to the other formulas. Overall, 80.0% of 2,068 posterior chamber intraocular lenses from seven different manufacturers demonstrated less than one diopter of prediction error and only 0.5% had three or more diopters of error. In short eyes (less than 22 mm), 74.0% were corrected to within one diopter and less than 2.0% had three or more diopters of error. In long eyes (greater than or equal to 24.5 mm), 78.0% of cases demonstrated less than one diopter of error and less than 1.0% had three or more diopters of error. Although the SRK II formula is incorporated in most new A-scan units, the modifications are so simple that surgeons can take the standard SRK predictions and mentally calculate the modifications for extreme cases.

Lens cortex irrigation/aspiration in extracapsular cataract extraction

There are many good methods of removing lens cortex during extracapsular cataract extraction in use today. Features of some of these are presented. Flow volume of irrigation solution and depth of the anterior chamber are discussed, and it is recommended that adequate flow volume be used to maintain a comfortably deep anterior chamber during irrigation and aspiration.

Comparison of empirically derived and theoretical aphakic refraction formulas

A formula for predicting aphakic refraction from axial length and keratometry measurements was derived from 120 cases, using linear regression analysis, as follows: Psp = 80.4 - 1.65L -0.7K, where P indicates aphakic spectacle power in diopters; L, axial length in millimeters; and K, result of keratometry in diopters. The prediction accuracy of this simple formula was compared with that of a complex theoretic formula based on geometric optics in 205 additional cases. The prediction accuracy of the theoretic and linear regression-derived formulas was virtually identical despite their differences in complexity and derivation. The differences and similarities between theoretic-derived and regression-derived aphakic and pseudophakic prediction formulas are discussed.

Comparison of the accuracy of the Binkhorst, Colenbrander, and SRK implant power prediction formulas

The prediction accuracy of the Binkhorst, Colenbrander, and SRK formulas were compared in five series from different sources totalling 654 cases. The SRK formula was superior to both the other formulas by having a smaller average error per case, a smaller range of error from highest minus to highest plus, and a smaller proportion of cases with greater than 2 diopters (D) of error in all five series studied. In four of the five series, the SRK formula also had the greatest proportion of cases with less than 1 D of error. The Colenbrander formula was superior to the Binkhorst formula in all five series with regard to average error, proportion of cases with less than 1 D of error, and proportion of cases with more than 2 D of error. The range of error from highest minus to highest plus was equivalent with the two formulas. All available published literature on the accuracy of implant power prediction formulas was reviewed and appears to support our findings.

Posterior chamber implant power calculation: regression formulas

Data from 230 eyes with posterior chamber lens implants were used to compare the prediction accuracy of different lens power formulas. Regression formulas gave more accurate results than did theoreic formulas.

A new intraocular lens calculation formula

Data from 166 eyes with iridocapsular implants were analyzed and different prediction methods were compared. A new formula was derived which predicted implant power better than any other method. The theoretic formulas and correction factors of Fyodorov, Colenbrander, and others were examined in detail and compared to the more accurate, simpler linear regression formula derived in this study.