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Biomedical subjects

R B Brauer

Publications and source records attributed to R B Brauer.

At least 19 recordsLinked to original sources
PubMed2003

External fixation of distal radial fractures: four compared with five pins: a randomized prospective study.

BACKGROUND: The purpose of this study of distal radial fractures was to compare the radiographic and clinical results after use of a standard four-pin external fixator with those after use of a five-pin fixator with the fifth pin stabilizing the distal radial articular fragment. METHODS: In an open prospective trial, fifty patients with an unstable distal radial fracture were randomized for treatment with closed reduction and either a standard small Association for the Study of Internal Fixation (ASIF) four-pin fixator (twenty-five patients) or a five-pin external fixator (twenty-five patients). The fixators were removed at nine weeks, and all patients were assessed radiographically and clinically at six months. RESULTS: Follow-up radiographs demonstrated significantly less loss of alignment and length with the five-pin external fixator. Pin site infections were more prevalent with the four-pin fixator. The range of motion of the wrist and forearm, the grip strength, and the Lidstrom functional ratings at six months were all significantly better after use of the five-pin fixator. CONCLUSIONS: The use of a five-pin external fixator, with the fifth pin stabilizing the distal radial articular fragment, yields better radiographic and functional results than does a four-pin fixator.

Adult↗
PubMed2001

Urgent carotid endarterectomy for stroke in evolution.

BACKGROUND: Carotid endarterectomy (CEA) is well established as the elective treatment for moderate or severe carotid stenoses with a history of neurologic symptoms. In contrast, the merits of carotid revascularisation performed in emergency in patients with acute stroke or fluctuating neurological deficit remain controversial. PATIENTS AND METHODS: A total of 445 CEAs were performed on 424 patients for 212 (48%) asymptomatic and 233 (52%) symptomatic carotid stenoses within a 5 years period between January, 1995, and December, 1999. Of the latter, CEA was performed in emergency on 16 patients (3.8%) within 4 to 24 hours after the onset of symptoms. Patients selected for urgent surgery fulfilled the following criteria: acute onset of fluctuating hemispheric neurological symptoms, significant carotid pathology, absence of cerebral hemorrhage, uncompromised vigilance and stable cardiopulmonary conditions. Selected patients presented with a crescendo-TIA (n = 7) or fluctuating neurological deficits (n = 9) corresponding to a contralateral carotid stenosis. RESULTS: Following CEA, the neurological deficits improved instantaneously to complete recovery in 9 patients. The symptoms of 4 patients improved to non-disabling deficits, remained unchanged in one and worsened in 2 patients from hemihypaesthesia to hemiparesis. 14/16 patients were discharged within 8 days after admission. The neurologic status after discharge did not deteriorate in any of the patients during follow up of 19.3 +/- 13 months, but improved in 4 of the patients. CONCLUSION: Our retrospective study suggests that rescue CEA may be beneficial for selected patients with stroke in evolution and fluctuating neurological deficits. Careful adherence to selection criteria, intraoperative shunting, intensive care post surgery surveillance and an experienced team are recommended.

Aged↗
PubMed2000

Osseous integration of bovine hydroxyapatite ceramic in metaphyseal bone defects of the distal radius.

Hydroxyapatite ceramic made of bovine spongiosa was used as structural support material in a prospective study to correct bone defects experienced after reduction in distal radius fractures. The study took place over a 3-year period (1992-1999) and comprised 14 patients. Osseous integration was analyzed via biopsies and magnetic resonance imaging. Long-term follow-up monitoring involving magnetic resonance imaging in 13 of the 14 patients showed fibrovascular growth within incorporated hydroxyapatite material. Osseous integration was demonstrated in magnetic resonance images by gadolinium uptake and by the presence of osteoid layers and endothelialized vessels. Hydroxyapatite ceramic offers a biologically acceptable alternative to autologous bone when augmenting distal radius fracture fixation.

Adult↗
PubMed2000

Endotoxin-induced lung inflammation is independent of the complement membrane attack complex.

Several products of the activated complement system are known to modulate endothelial cell function in vitro. It has been shown that the membrane attack complex (MAC) (C5b-C9) can enhance tumor necrosis factor alpha (TNF-alpha)-induced expression of P- and E-selectin and intercellular adhesion molecule type 1 in cell cultures of human umbilical vein endothelial cells. In the present study the potential role of this synegism for lung injury during endotoxin-mediated septic shock in vivo was examined using a model of C6-deficient PVG (C-) (RT1(C)) rats and the congenic PVG (C+) (RT1(C)) strain. Following administration of a high (5 mg/kg) or low (0.5 mg/kg) dose of lipopolysaccharide (LPS) (Escherichia coli O55:B5), we determined the expression of cytokines, chemokines, and adhesion molecules as well as the recruitment of leukocytes in the lung. Challenge with intraperitoneal i.p. injections of LPS resulted in a strong induction of TNF-alpha, interleukin-1alpha/beta, cytokine-induced neutrophil chemoattractant, interferon-inducible protein 10, macrophage inflammatory proteins 1alpha and 2, macrophage chemotactic protein 1, and P-selectin. However, there were no significant differences between PVG (C-) and PVG (C+) rats. Immunoperoxidase staining showed a similar increase of lung infiltration by CD11b/c(+) leukocytes in both rat strains. We therefore conclude that the described synergism between TNF-alpha and the MAC of the complement system on the induction of endothelial adhesion molecules is dispensable for inflammatory processes during endotoxin-mediated septic shock in vivo.

Animals↗
PubMed2000

[Surgical and interventional therapeutic possibilities in aneurysms of the subclavian artery].

Aneurysms of the subclavian artery are extremely rare and most commonly caused by arteriosclerosis, trauma or thoracic outlet syndrome. Less frequently seen causes also include syphilis, cystic media necrosis or tuberculosis or congenital anomalies. The presence of a subclavian aneurysm can give rise to various symptoms such as a pulsating supraclavicular mass, peripheral embolism or brachial plexus compression. Generally, surgical intervention is undertaken involving ligation and extirpation of the aneurysm followed by interposition of either a saphenous vein- or synthetic vascular graft. Recent diversifications in potential therapeutic strategies include the clinical application of transluminally positioned stents for the treatment of vascular lesions. In the literature review we found more than 260 published cases of surgically treated subclavian aneurysms and additional 17 subclavian aneurysms treated by endoluminal stent application. From 1992-1997 5 subclavian aneurysms were resected in our hospital. In four cases a vein graft of the vena saphena magna and in one case a PTFE graft were used. The sensory ischaemic deficit regressed in the further follow up in four of the five cases. Patency was checked postoperatively by ultrasound sonography, angiography or MR-angiography.

Adult↗
PubMed1997

[Use of the Herbert screw with the freehand method for osteosynthesis of acute scaphoid fracture].

Scaphoid fracture is, in most cases, usually still treated conservatively. The disadvantages of long-term immobilization are stiffness of the wrist joint, loss of strength and higher costs. The osteosynthesis of the scaphoid fracture with the Herbert bone screw restores the exact form and length and the normal position of the scaphoid to the other carpal bones. It prevents non-unions, arthrosis and other late complications. The Freehand method is used as a percutaneous technique without utilization of a jig. The scaphoid fracture is treated with closed reduction and osteosynthesis is performed with the Herbert bone screw. The percutaneous technique preserves the inter- and intracarpal ligaments, the vascular supply and the articular surfaces of the scaphoid. Osteosynthesis by the Freehand method is sufficiently stable to withstand early functional moves on the first postoperative day.

Adult↗
PubMed1997

Liver transplantation for the treatment of fulminant hepatic failure induced by the ingestion of ecstasy.

Methylenedimethoxymethamphetamine (MDMA), more commonly known as ecstasy, is a synthetic amphetamine derivative used by teenagers and young adults in the United States as well as in Western Europe as a "dance drug". Though a number of complications associated with this drug have been reported, there is little information pertaining to hepatoxity as a result of MDMA ingestion. This case report is about an 18-year-old female patient who regularly used ecstasy on weekends over a 2-month period. Within 2 days after accepting a "hit" of the substance at a party, she was admitted to the hospital because of lethargy, vomiting, abdominal pain, stool discoloration, icterus, and darkened urine. On day 7 she developed fulminant hepatic failure with reduced hepatic coagulation factors and grade IV encephalopathy. Orthotopic liver transplantation was carried out 10 days following the ingestion. The patient made a full recovery within 72 h and was released from the hospital 6 weeks later. Histopathological examination of the removed liver revealed a nutritive-toxic liver necrosis. This case demonstrates that the ingestion of ecstasy, even on an infrequent basis, can lead to acute fulminant liver necrosis, and that this life-threatening complication can be treated successfully by liver transplantation.

Adolescent↗
PubMed1997

Boerhaave's syndrome: analysis of the literature and report of 18 new cases.

Postemetic spontaneous rupture of the esophagus is an intrathoracic disaster which is generally lethal if untreated. The tragedy seems to strike more often than commonly suspected. The current literature review focuses on publications since 1980 and includes the retrospective review of 18 additional patients treated in our hospital for spontaneous rupture of the esophagus. Frequently, a wide variety of unspecific symptoms has led to the mistaken diagnosis of an acute abdomen, pancreatitis or cardiac arrest. About 40% of the patients with spontaneous rupture of the esophagus presented a history of alcoholism or heavy drinking and 41% suffered from gastroduodenal ulcer disease. Pain (83%) and vomiting (79%) often associated with dyspnea (39%) and shock (32%) are the major symptoms. This unspecific symptomatology delayed the correct diagnosis of the Boerhaave's syndrome and resulted in a significant complication rate. The mortality rate associated with Boerhaave's syndrome was 50% from the first successful surgical repair in 1947 by Barrett to 1980. After 1980, however, the mortality rate dropped to 31%, because of earlier diagnosis, surgical repair and improvement in intensive care. When surgery is delayed, the prognosis of patients with spontaneous rupture of the esophagus is in general severe.

Abdomen, Acute↗
PubMed1996

Requirement and role of C5a in acute lung inflammatory injury in rats.

The complement activation product, C5a, may play a key role in the acute inflammatory response. Polyclonal antibody to rat C5a was used to define the requirements for C5a in neutrophil-dependent inflammatory lung injury after systemic activation of complement by cobra venom factor (CVF) or after intrapulmonary deposition of IgG immune complexes. In the CVF model, intravenous infusion (but not intratracheal instillation) of anti-C5a produced a dose-dependent reduction in lung permeability and in lung content of myeloperoxidase. In C6-deficient rats, CVF infusion caused the same level of lung injury (measured by leak of 125I-albumin) as found in C6-sufficient rats. In the IgG immune complex model of lung injury, anti-C5a administered intratracheally (but not intravenously) reduced in a dose-dependent manner both the increase in lung vascular permeability as well as the buildup of lung myeloperoxidase. Treatment with anti-C5a greatly suppressed upregulation of lung vascular intercellular adhesion molecule-1 (ICAM-1). This was correlated with a substantial drop in levels of TNFalpha in bronchoalveolar fluids. These data demonstrate the requirement for C5a in the two models of injury. In the IgG immune complex model, C5a is required for the full production of TNFalpha and the corresponding upregulation of lung vascular ICAM-1.

Animals↗
PubMed1996

Functional activity of anti-C6 antibodies elicited in C6-deficient rats reconstituted by liver allografts. Ability to inhibit hyperacute rejection of discordant cardiac xenografts.

A critical role of the complement membrane attack complex (C5b-9) in mediating hyperacute rejection has been demonstrated previously in fully C6-deficient PVG (C-)(RT1c) rats that reject guinea pig cardiac xenografts at a delayed tempo (45 +/- 9 hr; n=16) compared with C6-sufficient PVG (C+)(RT1c) hosts (0.5 +/- 2 hr; n=6). We have investigated whether selective depletion of C6 from Lewis rats by antibody therapy prevents hyperacute rejection. A polyclonal rat-antirat C6 antibody was induced in PVG (C-) recipients by orthotopic liver transplants from congenic PVG (C+) donors. These liver grafts produced high levels of C6 that reconstituted the complement function of PVG (C-) hosts by 7 days, but the recipients responded within 28 days with the synthesis of an IgG1 antibody to rat C6. The antiserum inhibited hemolytic complement activity of Lewis (RT1(1)) rats in vivo and in vitro. The effect of C6 depletion on Xg survival was investigated by injecting Lewis rats with 2 ml of rat-antirat C6 antiserum before and 1 ml after reperfusion of the guinea pig cardiac xenograft. Lewis rats rejected guinea pig cardiac xenografts after treatment with this rat-antirat C6 antiserum in 38 +/ -11 hr (n=3). Treatment with normal control sera from PVG (C-) rats did not prolong guinea pig cardiac xenograft survival in the Lewis rats (1 +/- 0.7 hr; n=3)(P<0.0043). Injection of 3 ml of the IgG fraction purified from the rat-antirat C6 antibody (33 mg/ml) prolonged xenograft survival to 13.6 +/- 4 hr (n=4) compared with the survival of 0.61 +/- 0.3 hr (n=4) after injection of control rat IgG (33 mg/ml) (P<0.005). These results demonstrate that specific depletion of C6 by antibody therapy has a significant effect on guinea pig cardiac xenograft survival in the Lewis rat. These findings further suggest that C6 depletion may be beneficial to patients undergoing hyperacute rejection of xenografts or allografts.

Animals↗
PubMed1995

Extrahepatic synthesis of C6 in the rat is sufficient for complement-mediated hyperacute rejection of a guinea pig cardiac xenograft.

The liver is the major source of complement (C) components, but extrahepatic sources of C, such as macrophages and endothelial cells, have been hypothesized to contribute to inflammation. Our experiments demonstrate that extrahepatically produced C6 can contribute to hyperacute rejection. PVG (RT1c) rats with normal C activity (PVG (C+)) reject guinea pig cardiac xenografts in 0.5 +/- 0.2 hr, but fully C6-deficient PVG (RT1c) rats (PVG (C-)) reject guinea pig cardiac xenografts in 45 +/- 9 hr. PVG (C+) rats, which received liver transplants from PVG (C-) rats and retained all extrahepatic sources of C6, rejected guinea pig cardiac xenografts in 0.6 +/- 0.03 hr (n = 3). PVG (C-) rats, which received bone marrow transplants from PVG (C+) rats, had C6 levels restored to 10% of that of the donor and rejected guinea pig cardiac xenografts in 9 +/- 3.2 hr (n = 5). Thus, extrahepatic sources of C6 can contribute to xenograft rejection.

Animals↗
PubMed1995

The contribution of terminal complement components to acute and hyperacute allograft rejection in the rat.

Acute rejection and antibody-mediated hyperacute allograft rejection are affected by activation of the complement cascade. Split products of early complement components influence the localization, activation, and effector functions of platelets, granulocytes, monocytes, and lymphocytes, while the formation of membrane attack complex (C5b-C9) can lead to rapid cell destruction. Therefore, we compared acute and Ab-mediated hyperacute allograft rejection in a recently described model of C6 deficient PVG (C-) (RT1c) rats and their normal counterpart PVG (C+) (RT1c) rats. Cardiac allografts from fully MHC disparate ACI donors were heterotopically grafted into naive and skin graft sensitized PVG (C-) and PVG (C+) rats. ACI cardiac allografts were rejected acutely (8.3 +/- 2 days; n = 7) by naive PVG (C+) recipients, but survived significantly longer in PVG (C-) recipients (22 +/- 10 days; n = 10). Presensitized PVG (C+) rats rejected ACI cardiac allografts hyperacutely in 6.1 +/- 2.4 hr (n = 5). In contrast, ACI cardiac allografts transplanted into presensitized (PVG (C-) rats had markedly longer survival of 91 +/- 14 hr (n = 5). The alloantibody responses of naive PVG (C+) and PVG (C-) recipients 7 days after cardiac allografting, and of presensitized PVG (C+) and PVG (C-) recipients at time of cardiac allografting were not significantly different as measured by flow cytometry against ACI lymphocytes. Immunofluorescence demonstrated deposition of IgM, IgG and C3 in ACI allografts in PVG (C-) as well as in PVG (C+) recipients. Deposition of C6 was only found in grafts rejected by PVG (C+). The significantly longer survival of ACI cardiac allografts in C6-deficient PVG (C-) rats indicates that the membrane attack complex contributes to acute as well as antibody-mediated hyperacute allograft rejection.

Acute Disease↗
PubMed1994

Hepatic and extrahepatic biosynthesis of complement factor C6 in the rat.

The relative contributions of liver and bone marrow (BM) constituents to systemic C6 production were compared in a rat model. Liver grafts were transplanted from C6-sufficient PVG (RT1c) rats (PVG (C+)) to profoundly C6-deficient PVG rats (PVG (C-)). C6 levels were restored to 32% within 24 h and reached more than 80% of that of the PVG (C+) donor within 7 days post-grafting, which indicates that the liver is a primary source of systemic C6 production. When livers were transplanted from PVG (C-) to PVG (C+) rats (n = 3), levels of C6 dropped to 42% of pretransplant levels within 24 h and remained between 30 and 40% for more than 100 days after grafting. To determine the source of extrahepatic C6 production, BM was transplanted from PVG (C+) to PVG (C-) rats after total body irradiation. Levels of C6 increased from undetectable levels to 5% of C6 levels of the donor PVG (C+) rat within 60 days. Replenishing PVG (C-) recipients with BM after treatment of recipients with busulfan, which preferentially allows reconstitution with donor myelomonocyte stem cells, resulted in restoration of C activity. Treatment with cyclophosphamide before BM transplantation, which preferentially allows reconstitution of lymphoid stem cells, did not restore hemolytic C activity in PVG (C-) rats. These results were confirmed directly by the successful restoration of C activity with BM depleted of lymphocytes by counterflow centrifugal elutriation from PVG (C+) rats. These in vivo experiments demonstrate that the liver is a primary, but not the sole, source of C6 in the rat and that extrahepatic sources, such as myelomonocytes, and not lymphoid cells in the BM produce a significant amount of systemic C6 in the rat.

Animals↗
PubMed1993

Use of C6-deficient rats to evaluate the mechanism of hyperacute rejection of discordant cardiac xenografts.

C plays a critical role in the hyperacute rejection (HAR) of discordant xenografts (Xg), but the relative contribution of early vs late C components is unknown. In this study, genetic differences in C6 activity were correlated with HAR of guinea pig cardiac Xg by the rat. Seven rat strains were tested for C activity. Six strains (PVG.R1 (R1), PVG.1A (1A), DA, W/F, F344, LEW) had readily detectable C activity in the total and alternative pathways. Some PVG rats also had adequate C activity [PVG (C+)] but others [PVG (C-)] had a profound C6 deficiency. All rats with adequate C activity (n = 35) rejected cardiac Xg between 15 and 80 min. PVG (C+) (n = 6) rats also rejected cardiac Xg hyperacutely (26 +/- 12 min), whereas PVG (C-) (n = 16) rats, which had high preformed IgM natural antibody titers, rejected cardiac Xg in 1 to 2 days (2678 +/- 542 min). Transfer of serum from R1 rats to PVG (C-) recipients with vigorously beating Xg caused HAR of cardiac Xg within 116 +/- 75 min. Transfer of fresh PVG (C-) serum or heat-inactivated R1 serum did not induce HAR. HAR was characterized by intravascular platelet aggregation and interstitial hemorrhage, whereas Xg transplanted to PVG (C-) recipients had patent vessels at 30 min but were heavily infiltrated by granulocytes and monocytes at 2 days. These findings indicate that a deficiency in C6 prevents HAR but allows an accelerated acute rejection that may be mediated by the generation of vasoactive and chemotactic C3a and C5a.

Animals↗