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Michael Sander

Publications and source records attributed to Michael Sander.

22 records · Page 2Linked to original sources
PubMed2003

Synthesis of stable derivatives of c(62): the first nonclassical fullerene incorporating a four-membered ring.

A rational synthetic approach to the first four-membered ring-containing derivatives of C(62) is reported. They were synthesized by an inverse electron demand Diels-Alder reaction of 3,6-diaryl-1,2,4,5-tetrazines with C(60) in o-dichlorobenzene, followed by visible light irradiation at reflux. The structure of these nonclassical fullerenes derivatives was determined by X-ray single-crystal diffraction.

Journal Article↗
PubMed2002

Combined inhibition of nitric oxide and prostaglandins reduces human skeletal muscle blood flow during exercise.

The vascular endothelium is an important mediator of tissue vasodilatation, yet the role of the specific substances, nitric oxide (NO) and prostaglandins (PG), in mediating the large increases in muscle perfusion during exercise in humans is unclear. Quadriceps microvascular blood flow was quantified by near infrared spectroscopy and indocyanine green in six healthy humans during dynamic knee extension exercise with and without combined pharmacological inhibition of NO synthase (NOS) and PG by L-NAME and indomethacin, respectively. Microdialysis was applied to determine interstitial release of PG. Compared to control, combined blockade resulted in a 5- to 10-fold lower muscle interstitial PG level. During control incremental knee extension exercise, mean blood flow in the quadriceps muscles rose from 10 +/- 0.8 ml (100 ml tissue)(-1) min(-1) at rest to 124 +/- 19, 245 +/- 24, 329 +/- 24 and 312 +/- 25 ml (100 ml tissue)(-1) min(-1) at 15, 30, 45 and 60 W, respectively. During inhibition of NOS and PG, blood flow was reduced to 8 +/- 0.5 ml (100 ml tissue)(-1) min(-1) at rest, and 100 +/- 13, 163 +/- 21, 217 +/- 23 and 256 +/- 28 ml (100 ml tissue)(-1) min(-1) at 15, 30, 45 and 60 W, respectively (P < 0.05 vs. control). In conclusion, combined inhibition of NOS and PG reduced muscle blood flow during dynamic exercise in humans. These findings demonstrate an important synergistic role of NO and PG for skeletal muscle vasodilatation and hyperaemia during muscular contraction.

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PubMed2002

Myocardial ischemia and cytokine response are associated with subsequent onset of infections after noncardiac surgery.

UNLABELLED: Postoperative myocardial ischemia (POMI) is prevalent among patients after major noncardiac surgery. Surgery, as well as POMI, may modulate the immune system, potentially worsening patient outcome. We sought to investigate the modulation of soluble interleukin (IL)-6 and IL-10 by POMI and its association with increased postoperative infection rates. Two-hundred-three patients undergoing elective major abdominal, vascular, and orthopedic surgery participated in this prospective observational study. Perioperative management was standardized. Hemodynamic variables were kept within 20% of baseline. POMI was assessed by Holter electrocardiography starting at least 8 h before the induction of anesthesia and continued until 96 h after surgery. Twelve-lead electrocardiograms, cardiac enzymes, and immune variables were obtained at the time of admission to the hospital, before surgery, before the induction of anesthesia, after surgery, at the time of admission to the intensive care unit, and 6, 12, 18, 24, 36, 48, 72, 96, 120, 144, and 168 h after surgery. Infections were diagnosed according to the Centers for Disease Control criteria. The incidence of POMI was 27%, and the majority of cases (76%) occurred within the first 24 h after surgery. IL-6 and IL-10 levels significantly increased during surgery but did not differ between the POMI and Non-POMI groups. However, in the subset of patients who developed severe infections or sepsis (n = 47) a median of 3 days (range, 1-8 days) after surgery, the intraoperative increases of IL-6 and IL-10 in the POMI group were, respectively, 3 and 10 times higher compared with the increase in the Non-POMI group. By using a multifactorial analysis in these patients with severe infections, the type of surgical trauma was associated with an increased IL-6 response, whereas the increase in IL-10 was attributed to POMI. These findings suggest that immediate cytokine responses due to POMI and type of surgery might be relevant for the later onset of severe infections and sepsis. IMPLICATIONS: Postoperative myocardial ischemia (POMI) occurred in 27% of patients after major noncardiac surgery. This was associated with an immediate augmented cytokine response in the first 12 h after surgery in patients who developed severe infections or sepsis 3 days later. POMI was associated with an increased interleukin (IL)-10 response, whereas IL-6 was associated with the type of surgery.

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