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Biomedical subjects

E Schaller

Publications and source records attributed to E Schaller.

At least 19 recordsLinked to original sources
PubMed1999

The resistance against Listeria monocytogenes and the formation of germinal centers depend on a functional death domain of the 55 kDa tumor necrosis factor receptor.

The biological functions mediated by the death domain of the 55-kDa tumor necrosis factor receptor (TNFRp55) in vivo are still elusive. TNFRp55 mutants lacking a functional death domain were expressed in TNFRp55-/- and in TNFRp55+/- mice as transgenes under control of the H-2Kb promoter. Analysis of these animals revealed that signals originating from the TNFRp55 death domain are indispensable for the protection against Listeria monocytogenes, the expression of mucosal addressin cell adhesion molecule-1 (MAdCAM-1) in the spleen and the development of splenic germinal centers. Furthermore, the transgenic coexpression of the TNFRp55 mutants in TNFRp55+/- mice exerts a dominant negative effect on the signaling of the endogenous receptor chains in vivo.

Animals↗
PubMed1999

The use of low-level jets by migrating birds.

Birds flying at high altitudes have occasionally been observed above mountain areas and the open sea. For the first time the regular occurrence of migrating birds flying within a low-level jet at heights of 5000 to almost 9000 m asl. have now been verified by radar above the Negev desert in southern Israel. Tracks of rather large birds with wing-beat frequencies of 5-6 Hz were measured to have horizontal flight speeds up to 50 m/s. Visual observations, seasonal occurrence, and wing-beat frequencies allowed to associate them with small species of the order Ciconiiformes (mainly Ardeidae) and possibly with members of the Laro-Limicolae group. These wading birds seem prone to continuing nocturnal migration into daytime under favorable conditions and to make use of high wind speeds at sometimes extreme altitudes.

Altitude↗
PubMed1998

Use of beta-hydroxybutyric acid levels in the emergency department.

UNLABELLED: The impact of a new test on the market, the beta-hydroxybutyric acid (BOH) assay, on clinical decision-making in the emergency department (ED) has not been well studied. In this retrospective analysis, we studied the potential benefit of this new test in the ED decision-making process in diabetic patients. BOH levels were measured on all patients who had glucose and acetone levels ordered by the emergency physician during a 3-month period in the ED of a university tertiary referral center. Two groups were analyzed: group 1 was acetone-positive and BOH-positive (n = 13); group 2 was acetone-negative BOH-positive (n = 31). There was no difference between the two groups in terms of gender (p = 0.55) or age (p = 0. 47). The length of stay (p = 0.97) and number of complications (p = 0.89) were also similar between the two groups. CONCLUSION: This study suggests that in those diabetic patients with a negative acetone test and a positive BOH test, the addition of the positive result on the BOH test may provide additional prognostic information for predicting hospital length of stay and number of in-hospital complications.

3-Hydroxybutyric Acid↗
PubMed1997

Multicenter study of Abbott AxSYM Digoxin II assay and comparison with 6 methods for susceptibility to digoxin-like immunoreactive factors.

Performance characteristics of the Abbott nonpretreatment AxSYM Digoxin II assay were evaluated for quantification of digoxin at four independent sites. Correlation of digoxin measurements with the Abbott pretreatment AxSYM, Baxter Stratus II, Abbott TDx/ TDxFLx II, Abbott IMx, Emit 2000, and Beckman Synchron CX digoxin assays showed acceptable agreement, as indicated by: slope values > 0.84, r > 0.90, y-intercepts for all comparisons at or below the assay detection limit, and Sy/x ranging between 7.5% and 15.4% of the average digoxin value. Susceptibility to interference from digoxin-like immunoreactive factors (DLIFs) was examined in 233 samples from renal patients, liver disease patients, cord blood, and third-trimester pregnancies; the AxSYM Digoxin II assay demonstrated the least DLIFs interference. DLIF susceptibility for four of the methods was significantly greater (P < 0.05) than in the AxSYM Digoxin II assay; susceptibilities of the Stratus II and Emit 2000 methods were similar to the AxSYM Digoxin II assay.

Autoanalysis↗
PubMed1996

Technetium-99m human immunoglobulin (HIG): a new substance for scintigraphic detection of bone and joint infections.

Technetium (99m-Tc)-labelled, polyclonal human immunoglobulin (HIG) has been described as a new agent to detect local infection and inflammation. In this study, we tested 99m-Tc HIG in 55 patients with suspected chronic (n = 42) and acute (n = 13) skeletal infection. Diagnosis was proven operatively (n = 44) and clinically (n = 11), including microbiological culture tests (n = 46). A gamma camera scan was performed 4 and 24 hours after I.v. injection of 500 MBq 99m-Tc-HIG. 99m-Tc-HIG scanning achieved a sensitivity of 91% and a specificity of 93%. We found one false negative and five false positive scintigraphic results in 55 patients. No clinical or biochemical side effects were encountered after 99m-Tc-HIG injection. We recommend this technique especially for localisation of low-grade, chronic osteomyelitis. The mechanisms and kinetics of 99m-Tc-HIG, however, are worth investigating more extensively.

Acute Disease↗
PubMed1995

Frequency of toxic shock syndrome toxin- and enterotoxin-producing clinical isolates of Staphylococcus aureus.

In 183 clinical isolates of Staphylococcus aureus, toxic shock syndrome toxin was detected in 13.7%, enterotoxin A in 20.2%, enterotoxin B in 7.7%, enterotoxin C in 5.5% and enterotoxin D in 3.3%. Seventy-three (39.9%) of the strains were found to produce one or more toxins. Multiple secretion of toxins was rare (< 1% of all strains) except for the combinations enterotoxin A with toxic shock syndrome toxin and enterotoxin A with enterotoxin D. These combinations were observed at significantly higher frequencies (4.9% and 2.2%, respectively) than would have been expected from values calculated from respective individual frequencies (0.88% and 0.06%) (p < 0.0001). In comparison with Staphylococcus aureus strains isolated from miscellaneous material, Staphylococcus aureus blood culture isolates produced enterotoxin D in significantly larger amounts and at higher frequencies (p = 0.01 in both cases). These toxins might play an important pathogenic role in Staphylococcus aureus infections.

Bacterial Toxins↗
PubMed1994

[The Dellon tube in injuries of peripheral nerves].

Experimental efforts are being undertaken to improve nerve transplantation as a method for peripheral nerve repair. Major disadvantages of nerve transplantation are the creation of neurologic deficits at the donor site and the limited availability of nerve grafts. Mackinnon and Dellon propose the interposition of synthetic, biodegradable tubes as a nerve conduit for clinical use. This method is described according to its theoretical background and the surgical technique. The interposition of synthetic tubes seems possible for short defects in finger nerves, but will render unfavourable results in long defects of peripheral mixed nerves.

Animals↗
PubMed1994

[Pulley for strengthening a muscle replacement operation across two joints in brachial plexus lesion: description of the surgical technique].

The reconstruction of lost muscle functions in cases of brachial plexus lesion is possible even in those cases where primary nerve reconstruction was not performed or unsuccessful. If there are only few motor nerves available, we prefer free latissimus dorsi transplantation or pedicled latissimus dorsi transposition for replacement of biceps and finger flexors. The combination of elbow flexion and finger flexion becomes possible when the transposed motor is passed around a suitable pulley in the elbow region like the flexor carpi ulnaris or carpi radialis.

Adult↗
PubMed1993

Enzymhistochemical evaluation of ulnar nerve grafts in brachial plexus lesions.

Our concept for the reconstruction of brachial plexus injuries includes an intercostal nerve transfer to the vascularized ulnar nerve graft. A free neurovascular latissimus dorsi is then transferred in a second stage operation. For optimization of the regeneration result, the operative planning of the second step includes nerve biopsies and enzymhistochemical evaluation for the distribution of motor axons. The staining method according to Scabolcz et al. is described and clinical cases are presented.

Brachial Plexus↗
PubMed1993

Preservation of peripheral nerve grafts with Schwann cell culture medium.

Preservation of peripheral nerves may, in the near future, play an important role in reconstructive surgery, especially if recent advances in immunosuppressive therapy are taken into account. Therefore, it has to be investigated whether peripheral nerves can be stored for some time after harvesting without diminishing their regenerative potential. Previous experiments of our group could demonstrate only little benefit of organ storage solution (HTK) or normal saline (NaCl 0.9%) to peripheral nerves when kept at cold ischaemia of 4 degrees C for 32 and 72 hours. In this presentation, we are reporting the results of peripheral nerve storage in Dulbecco's Modified Eagle Medium which has been used for Schwann cell culture. In 30 adult Sprague-Dawley rats, a 2.5 cm segment of the right sciatic nerve was harvested and kept at 4 degrees C for 14, 32, 72, and 120 hours. It was then reimplanted into the donor animal; regeneration quality was assessed clinically, histologically and morphometrically after 6 weeks. Best regeneration results were obtained in the 32 and 72 hour groups; regeneration here was comparable to the normal controls. These results are explained with the positive effect of nerve predegeneration.

Animals↗
PubMed1993

[Opposition-plasty after brachial plexus lesions by osteosynthesis].

Secondary reconstruction of lost muscle function in brachial plexus injuries is performed by dynamic muscle and tendon transposition, by free microvascular muscle transplantation and by static surgical procedures. In cases of weak function of the finger flexors, static opponensplasty is required. In these cases our procedure is the internal fixation of the base of the metacarpal I to the base of the metacarpal II without stabilisation of cancellous bone. From 1987 to 1992 we operated 15 patients by this procedure. Results are showing sufficient stabilisation and good function.

Bone Screws↗
PubMed1993

[A comparison of different treatment methods of pseudarthroses and recurrent pseudarthroses of the scaphoid].

From 1981 to 1990 110 scaphoid non-unions were operated on in our clinic. The period from 1986 to 1990 was followed up. During this time, 45 cases were surgically treated: 27 by Matti-Russe plasty, 11 by Herbert screw, and 7 by vascularized radial bone graft. The following criteria were compared: 1. Radiological signs of healing; 2. Period of immobilization; 3. Clinical results. The shortest period of immobilization and best wrist function was observed in patients treated by Herbert screw.

Adult↗
PubMed1991

Regeneration of autologous and allogenic nerve grafts in a rat genetic model: preliminary report.

The authors report observations concerning rejection and regeneration processes of allogenic peripheral neural tissue, depending on different genetic mismatches in a rat model. Five groups representing different rat strains (n = 100) were subjected to orthotopic grafting of 2.5-cm segments of sciatic nerve. Combinations represented different genetic barriers, including the Major Histocompatibility Complex (MHC), a non-MHC, a subgroup (A) of the MHC, a group representing MHC plus non-MHC, and an autologous control group. Animals were examined after one, two, and 12 weeks; additional evaluations in some of the experimental groups were done at six and eight weeks. Regeneration in varying degrees was evident in all groups at 12 weeks.

Animals↗
PubMed1991

Brachial plexus injuries: an integrated treatment concept.

An integrated concept is presented for the treatment of lesions of the brachial plexus. In such patients, nerve repair is useless as a single method of therapy. Only the combination of nerve repair with both conventional and new methods of muscle and tendon transfer, including the free muscle transplant innervated by vascularized nerve grafts, can give the patient functional use of the paralyzed arm.

Arm↗
PubMed1991

[The value of early intervention in hand infections].

The question whether delayed surgical treatment has any effect on recovery and invalidity in severe infections of the hand was evaluated in 91 cases. Immediate surgical treatment led to complete recovery in 90% of the cases, whereas surgical intervention one week later led to a significantly higher complication and amputation rate.

Adolescent↗
PubMed1990

Muscle transfers in brachial plexus lesions.

The concept of reconstruction to regain lost function after brachial plexus lesions has to be as broad and complex as possible. We have been exploring wider and more novel clinical concepts at the Clinic of Plastic, Hand, and Reconstructive Surgery at the Medical School of Hannover. Our ideas are supported by experience in 160 patients. We have attempted to combine the use of a vascularized nerve graft and a microvascularly-transferred autologous muscle. Patients undergoing the procedures have included those with late complete root avulsions and no functional return, as well as previously operated cases with poor recovery of biceps, wrist, and forearm function. The surgery is divided into two stages. In the first stage, the ulnar nerve is prepared as a vascularized nerve graft and is sutured to intercostal nerves 3 to 5 or 6. In stage 2, when the Tinel sign reaches the distal ends of the ulnar nerve graft (about six to eight months later), the latissimus dorsi muscle is harvested. The muscle is then placed as far distally as possible in the forearm and sutured to the deep finger flexors and flexor pollicis longus. Proximally, the insertion is performed similarly to Steindler's method. The vessels are connected to the brachial artery and vein and the thoracodorsal nerve is sutured to the graft. This method provides flexion of both the fingers and the elbow.

Adult↗
PubMed1990

[Adverse effects of cyclosporin A with special reference to the peripheral nervous system].

Since the introduction of Cyclosporine A (CsA) in 1972, several studies have focused on its effects on experimental autologous peripheral nerve transplants. Although several studies have reported neurotoxicity of CsA in the central nervous system, no such data exist regarding the peripheral nervous system. The present study focuses on the effects of CsA in the therapeutic and toxic doses on axon regeneration, particularly the rate and quality of axon regeneration. Autologous nerve transplantation was performed in Lewis rats and axon regeneration evaluated clinically (motor function, body weight), electroneurographically and histologically. In transplanted nerves, even high doses of CsA (30 mg/kg bodyweight) did not lead to delayed or impaired axon regeneration. Long-term application in normal peripheral nerves did however cause axon degeneration with edema and vacuolisation of myelin sheaths, retraction of myelin sheaths from the node of Ranvier, and marked enhancement of the Schmidt-Lantermann incisures. As neurological side effects such as tremor and paresthesia have been reported under application of CsA in man, the above data might be of clinical relevance.

Animals↗