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H-J Schäfers

Publications and source records attributed to H-J Schäfers.

10 recordsLinked to original sources
PubMed2006

The cervical lymph node preparation: a novel approach to study lymphocyte homing by intravital microscopy.

OBJECTIVE: Lymphocyte recirculation constitutes an integral part of the adaptive immune system. Blood-borne lymphocytes migrate into secondary lymphoid organs, crossing the vascular wall of site-specific high endothelial venules (HEVs). We created a preparation of the cervical lymph node in mice to study lymphocyte homing in vivo. METHODS AND RESULTS: Our novel approach allowed the detailed analysis of hemodynamics and lymphocyte-HEV endothelium interactions by means of intravital fluorescence microscopy. We confirm the key roles of L-selectin and LFA-1 for lymphocyte homing. Blockade of L-selectin function inhibited lymphocyte rolling and firm adhesion by 92% and 66%. In LFA-1-deficient mice, lymphocyte firm adhesion was reduced by 70%. In addition to the microcirculation studies, the cervical lymph node preparation allowed for visualization of afferent lymphatic transport, which is mainly derived from the oral mucosa. CONCLUSION: This study reports a novel technical tool for the detailed in vivo analysis of adaptive immune responses.

Animals↗
PubMed2006

[Acute aortic dissection. Differential diagnosis of a thoracic emergency].

Acute aortic dissection is an infrequent but important differential diagnosis of acute chest pain. The variability of presenting symptoms makes it difficult to diagnose correctly. Important clinical indicators - besides chest pain - are symptoms related to acute aortic insufficiency and/or pericardial tamponade, variable acute neurologic alterations, or signs of peripheral or visceral malperfusion. The spontaneous prognosis depends on the location and extent of the dissection, and left untreated dissection carries a high mortality. The key goal of preclinical treatment is stabilization with analgesia, mild sedation (opioids, benzodiazepines) and treatment of hypertension (beta-blockers) or hypotension (fluid administration). If the patient presents with a high probability of dissection, early transfer to a specialized center appears advisable. Initial clinical diagnostic studies include transthoracic echocardiogram and computed tomography. If the ascending aorta is involved (Stanford type A) immediate replacement of the proximal aorta is necessary. Isolated dissections of the descending aorta (type B) require aggressive blood pressure control, but can be managed conservatively in most cases. A high level of vigilance is necessary in all patients to detect and treat visceral ischemia.

Acute Disease↗
PubMed2006

Valve repair in aortic regurgitation without root dilatation--aortic valve repair.

BACKGROUND: Aortic valve repair was established in the context of aortic root remodeling. Variable results have been reported for isolated valve repair. We analyzed our experience with isolated valve repair and compared the results with those of aortic root remodeling. METHODS: Between October 1995 and August 2003, isolated repair of the aortic valve was performed in 83 patients (REP), remodeling of the aortic valve in 175 patients (REMO). The demographics of the two groups were comparable (REP: mean age 54.4 +/- 20.7 yrs, male-female ratio 2.1 : 1; REMO: mean age 60.8 +/- 13.6 yrs, male-female ratio 2.4 : 1; p = ns). In both groups the number of bicuspid valves was comparable (REP: 41 %, REMO: 32 %; p = ns). All patients were followed by echocardiography for a cumulative follow-up of 8204 patient months (mean 32 +/- 23 months). RESULTS: Overall in-hospital mortality was 2.4 % in REP and 4.6 % in REMO ( p = 0.62). Systolic gradients were comparable in both groups (REP: 5.8 +/- 2.2, REMO: 6.5 +/- 3.1 mm Hg, p = 0.09). The mean degree of aortic regurgitation 12 months postoperatively was 0.8 +/- 0.7 after REP and 0.7 +/- 0.7 after REMO ( p = 0.29). Freedom from significant regurgitation (> or = II degrees ) after 5 years was 86 % in REP and 89 % in REMO ( p = 0.17). Freedom from re-operation after 5 years was 94.4 % in REP and 98.2 % in REMO ( p = 0.33). CONCLUSIONS: Aortic regurgitation without concomitant root dilatation can be treated effectively by aortic valve repair. The functional results are equivalent to those obtained with valve-preserving root replacement. Aortic valve repair appears to be an alternative to valve replacement in aortic regurgitation.

Adult↗
PubMed2006

Heparin-protamine does not aggravate local LPS-provoked leukocytic inflammation in vivo.

OBJECTIVE: Secondary complications involving inflammation limit postoperative results in cardiac surgery. Because heparin-protamine can elicit inflammatory reactions, this study evaluates in vivo whether treatment with heparin-protamine aggravates local endotoxin-induced injury. METHODS: Mice received intravenous injections of either heparin-protamine, protamine alone or PBS for controls, before local air pouch challenge with LPS. Leukocytes recruited within the air pouches were collected and analyzed by flow cytometry. RESULTS: LPS provoked a local leukocytic infiltration in a dose- and time-dependent manner with significantly elevated numbers of 1.75 +/- 0.29 x 10 (6) cells after four hours compared to non-LPS-stimulated controls (0.55 +/- 0.08 x 10 (6) cells). Recruited cells comprised of 74 +/- 4 % PMNLs and 26 +/- 4 % MNLs. The largest fraction of MNLs was positive for the T cell-specific marker CD90.2 (59 +/- 6 %). B cells were only rarely observed (4 +/- 1 %). In non-LPS-challenged air pouches, heparin-protamine provoked a leukocytic infiltration, which was comparable to that observed after LPS (1.51 +/- 0.22 x 10 (6) cells). However, neither heparin-protamine nor protamine alone aggravated the LPS-mediated leukocyte recruitment (2.25 +/- 0.25 x 10 (6) and 1.77 +/- 0.23 x 10 (6) cells). Neither treatment influenced the distribution of leukocyte subpopulations compared to PBS-treated controls. Furthermore, surface expression of CD11a and CD11b on blood leukocytes did not differ between the groups, indicating that protamine does not increase the activation of circulating leukocytes during LPS-induced local inflammation. CONCLUSIONS: Our data indicate that heparin-protamine, although pro-inflammatory in nature, does not aggravate local inflammation provoked by LPS. Thus, enhanced inflammation during the perioperative course of cardiac surgery patients seems not to be attributable to the intraoperative use of heparin-protamine.

Animals↗
PubMed2005

[Cystic lesion of the dorsal mediastinum].

We present the case of a 52-year-old male who underwent thoracotomy for resection of a suspected bronchogenic cyst in the right posterior mediastinum. The size of the tumor had increased over years, according to repeated X-rays, and the cyst became symptomatic with obstruction of the right subclavian and jugular veins. To our surprise, histopathology revealed a hydatid cyst.

Bronchogenic Cyst↗
PubMed2004

[Iloprost and selective pulmonary vasodilation. Clinical results of intraoperative and postoperative inhalation of iloprost].

Pulmonary hypertension is a major risk factor in cardiac surgery and has significant impact on morbidity and mortality in the perioperative period. Nitric oxide (NO) is considered to be the gold standard for treatment of pulmonary hypertension in the perioperative setting. The aerosolized administration of the prostacyclin analogue iloprost is a new alternative with similar pulmonary-selective vasodilation and virtually no systemic side-effects. Relevant complications including increased postoperative bleeding have not been observed.

Administration, Inhalation↗
PubMed2004

[Pulmonary thromboendarterectomy].

Chronic thromboembolic pulmonary hypertension with concomitant right heart failure may develop as a sequela of acute pulmonary embolism with organization instead of thrombolysis of intravascular clots. Medical therapy aims at prevention of recurrent embolism by anticoagulation and vascular remodelling using vasodilator therapy. Lung transplantation or combined heart-lung transplantation is associated with unsatisfactory long-term results and comorbidity and therefore remains justified only in selected patients. Pulmonary thromboendarterectomy allows specific treatment of intravascular obstruction. This closed endarterectomy of the pulmonary arteries requires deep hypothermic circulatory arrest and can be performed with a perioperative mortality of less than 10%. The procedure significantly decreases pulmonary vascular resistance and often normalizes pulmonary hemodynamics and gas exchange. Postoperatively the patients' clinical condition improves and the majority have normal exercise capacity and activity.

Animals↗
PubMed2002

Mid-term results of aortic valve preservation: remodelling vs. reimplantation.

OBJECTIVE: Valve-preserving root replacement has become an accepted alternative to composite replacement both in dissection and in aneurysmal disease. We retrospectively analysed 5-year results comparing root remodelling and reimplantation procedures. METHODS: From October 1995 to January 2001, 119 patients underwent either root remodelling (group A; n = 98; age: 61 +/- 14 years) or valve reimplantation within a vascular graft (group B; n = 21; age: 47 +/- 17 years). In group A, 26 patients were operated for aortic dissection type A and 72 for aortic valve regurgitation and aneurysmal disease. In group B, 8 patients were operated for aortic dissection type A, 13 for aortic valve regurgitation and aneurysm. Concomitant arch surgery was performed in 65 patients (group A: 57; group B: 8). RESULTS: Time on cardiopulmonary bypass was 121 +/- 30 min in group A, 143 +/- 24 min in group B, and aortic cross-clamp time was 87 +/- 19 min in group A and 113 +/- 24 min in group B. Average duration was therefore longer in group B (p = n.s.) Hospital mortality was 3.1 % in group A and 0 % in group B. Following elective procedures, hospital mortality was 1.1 % in group A. Freedom from aortic regurgitation over grade 2 at 4 years was 86 % in group A and 94.7 % in group B. At 4 years, freedom from proximal reoperation was 97.8 % in group A and 100 % in group B. There was no deterioration of valve function or need for reoperation observed after 1 year in either group. CONCLUSION: Five-year results are comparable and encouraging for remodelling and reimplantation procedures. If the initial valve function and geometry is adequate, the chance of secondary failure beyond the first year is minimal.

Adult↗