Increased signs of acute rejection with ischemic time in a rat musculocutaneous allotransplant model.

BACKGROUND: Composite tissue allotransplantation (CTA) may restore a variety of tissue defects, but carries the potential risks of graft failure and/or immunosuppression-related complications. Ischemia-reperfusion injury has been documented in CTA is known to contribute to acute rejection of solid organ grafts. This study describes the influence of subcritical ischemic time (ie, ischemia sufficient to generate reversible cell damage) on signs of rejection of musculocutaneous allograft components of subcritical ischemic time, namely, ischemia sufficient to generate reversible cell injury. Although skin is considered the most antigenic component of a composite allograft and is currently used for rejection surveillance, muscle and adipose are more susceptible to ischemia-related injury. METHODS: Vascularized epigastric flaps were transplanted from WKY to Fisher 344 rats after 1 or 3 hours of ischemia. Biopsies taken on postoperative day 6 were graded for signs of acute rejection according to criteria modified from previously published grading systems for CTA rejection. RESULTS: Skin and muscle exposed to 3 hours of ischemia showed significantly higher rejection scores than after 1 hour of ischemia, as evidenced by a more aggressive diffuse lymphocytic infiltration with disruption of tissue architecture. The rejection score in skin with 3-hour ischemia was 5.0 +/- 0.1 versus 3.7 +/- 0.2 with 1-hour (Mann-Whitney U test; P < .05). The rejection score in muscle exposed to 3-hour ischemia was 3.6 +/- 0.3 versus 2.5 +/- 0.1 with 1-hour (P < .05). CONCLUSIONS: Muscle and skin demonstrated increased acute rejection of allotransplants with increased subcritical ischemic time. This study supports the use of aggressive methods to reduce subcritical ischemic injury during allotransplantation of composite tissue and inclusion of muscle in postoperative biopsies in this early investigational period of CTA.

[Facial allograft transplantation: fiction or reality? Surgical techniques in a fresh human cadaver model]. / Allogene Gesichtstransplantation: Fiktion oder Realität? : Darstellung chirurgischer Techniken am Leichenmodel.

BACKGROUND: The aim of this study was to describe two methods of face-harvesting techniques -- a skin and soft tissue flap and a combined osteocutaneous flap -- and to demonstrate the compatibility between donor and recipient in a human fresh cadaver model. METHODS: In fresh human cadavers the skin and soft tissue of the face (type 1) and a combined osteocutaneous flap (including a le Fort III segment, type 2) were harvested. The faces were subsequently exchanged among the donor crania, simulating full-face transplantation. RESULTS: Both flaps are based on the external blood supply of the faciotemporal vessels and the external jugular vein. The end branches of the trigeminal nerve could potentially be used for restoration of sensation (type 1 flap). With type 2 flaps the facial expression may be restored with the inclusion of the facial nerve. Four morphological parameters determine the donor/recipient compatibility: skin color and texture, anthropometric head dimensions, specific soft tissue components (nose, lip, cheek, and eyebrow), and gender. CONCLUSION: Apart from ethical considerations, long-term immunosuppression will remain the limiting factor of full facial transplantation in the near future.

Limb salvage with tumor endoprostheses for malignant tumors of the knee.

Data of 64 consecutive patients with malignant tumors of the knee treated with tumor endoprostheses between 1976 and 1996 were reviewed. The study was retrospective before 1990 and prospective since then. Four patients were lost to followup and are not included in the study. The average age of the remaining 60 patients was 33.2 years (range, 9-72 years). Fifty patients had surgery for primary sarcoma and 10 patients had surgery for metastases of carcinoma. In the patients in the sarcoma group, the probability of 5 years survival was 72% and 10 years survival was 69%. The overall clinical score of 47 patients with a followup more than 9 months was 81% using the evaluation system of the International Society of Limb Salvage. Fifty-eight reoperations were done in 29 patients because of complications. Twenty reoperations were attributable to soft tissue complications, 34 reoperations were because of mechanical problems related to the prostheses, and four were because of local tumor recurrence. The probability of survival of the leg of the patient after 10 years was 95%. Despite a high rate of complications after limb salvage with endoprostheses, the final clinical outcome usually was good.

Prolonged iron depletion after allogeneic 2-unit RBC apheresis.

BACKGROUND: Allogeneic 2-unit RBC apheresis is a safe procedure offering many advantages for donors and blood banks. A controlled study was performed to determine whether the recommended minimum interval of 4 months between 2-unit RBC apheresis donations is appropriate in terms of the recovery of RBCs and the regeneration of iron stores. STUDY DESIGN AND METHODS: Twenty male subjects each donated 2 units of RBCs by apheresis. The RBC count, reticulocyte count, EPO, and measures of iron status were analyzed before and during the 4 months after donation. RESULTS: A significant decrease in Hb (15.89 +/- 0.82 [mean +/- SD] vs. 14.08 +/- 0.97 mg/dL, baseline vs. Day 7; p<0.001) was equalized within 2 months. In contrast, ferritin values declined significantly from 54.2 +/- 33.7 to 23.42 +/- 21.94 microg per L (predonation vs. Day 30) and remained significantly below predonation values, but within the normal range, until the end of the study period. CONCLUSION: A donation interval of 4 months is appropriate in terms of RBC recovery, but may not be appropriate in terms of iron store regeneration. The tendency to shorten the donation interval should be reconsidered in light of the measurements of iron storage. The use of ferritin levels is recommended as a preselection criterion for allogeneic 2-unit RBC apheresis.

[Conservative treatment of cruciate ligament rupture. Magnetic resonance tomography provides prognostic information for conservative healing]. / Konservative Behandlung der Kreuzbandruptur. Die Kernspintomographie ermöglicht prognostische Aussagen zur conservativen Heilung.

Ruptures of the cruciate ligaments continue to pose both diagnostic and therapeutic problems. On the basis of structural analysis of MR images obtained after the accident and the results of conservative treatment, it can be shown that function healing of the rupture can result, when, for example, the synovial membrane (capsule) is preserved (70%). It proved possible to show and objectify this using MRI and measurements.

Influence of betaxolol and timolol on the visual fields of patients with glaucoma.

In a double-masked study, 40 patients with primary open-angle glaucoma were randomly assigned to treatment with betaxolol 0.5% or timolol 0.5% in both eyes twice daily. Visual fields and intraocular pressures were studied. Perimetry was performed with the Octopus G1 program two weeks after a washout period and three, six, 12, and 18 months after initiation of treatment. Both drugs reduced intraocular pressure. The reduction in intraocular pressure in the timolol-treated group was more pronounced than that in the betaxolol-treated group; the difference, however, was not statistically significant. In both treatment groups, the visual fields tended to improve during the first six months of treatment and remained stable or tended to deteriorate thereafter. The treatment effect on the visual field was better in the betaxolol-treated group than it was in the timolol-treated group (P = .041).

[Effect of betaxolol and timolol on visual fields in glaucoma patients]. / Einfluss von Betaxolol und Timolol auf das Gesichtsfeld bei Glaukompatienten.

In a prospective, randomized, double-masked study, primary open-angle glaucoma patients were treated twice daily with either betaxolol 0.5% or timolol 0.5%. Patients received a pretreatment baseline examination following a 2 week washout period; they were then examined after 3 and 6 months of treatment. Each examination included visual field measurements with an Octopus automated perimeter and intraocular pressure measurement. The visual fields of the betaxolol group showed on the average a pronounced tendency toward improvement (MD decrease of 2.05 dB); visual fields in the timolol group showed a slight tendency toward improvement (MD decrease of 1.56 dB). The difference between these 2 trends after 6 months was statistically not significant (p greater than or equal to 0.05, U-test). Both drugs lowered intraocular pressure, there was no significant difference between the two drugs (p greater than or equal to 0.05, U-test).

Octopus program G1X.

The glaucoma program G1 is widely employed by Octopus users. In addition to a specific distribution of test locations, its main advantages are the quick comparison of results with normal values and an easy follow-up. The program, however, is relatively time consuming and, therefore, tiring for some patients. For this reason, the program was modified to 'G1X'. This program is interruptable at any time and provides information, including statistical analysis based on the available data. The test sequence is rearranged in accordance with the importance of the information. The available information, including the confidence limits, is continuously calculated and presented on the screen of the Octopus 1-2-3 during the test procedure. This provides the possibility of adapting the measurement to the patients and their state of health. The principal features as well as clinical applications are described.

[The Opacity Lens Meter 701: clinical experiences]. / Opacity Lens Meter 701: Klinische Erfahrungen.

The quantitative influence of cataracts on visual fields was studied in 11 patients before and after cataract extraction with intraocular lens implantation. Lens opacity, measured with the Opacity Lens Meter 701, correlated closely with the visual field changes. Measurement of stray light backscattered from the cataractous lens permits quantitative prediction of the influence of cataract on the visual field.

Tryptophan residues of creatine kinase: a fluorescence study.

Spectroscopic studies of rabbit skeletal muscle creatine kinase (CPK) and its complexes with adenosine phosphates have long suggested the occurrence of a tryptophan residue at or near the coenzyme binding sites [Kägi, J. H. R., Li, T.-K., & Vallee, B. L. (1971) Biochemistry 10, 1007-1015; Price, N. C. (1972) FEBS Lett. 24, 21-23]. This conjecture was further supported by nuclear Overhauser effect (NOE) 1H NMR studies indicating through-space interactions between protons of the adenine ring of bound ADP and one or more aromatic side chains of the proteins [Vasák, M., Nagayama, K., Wüthrich, K., Mertens, M. L., & Kägi, J. H. R. (1979) Biochemistry 18, 5050-5055]. Further evidence for a tryptophan residue in the environment of the active site has now been obtained by fluorescence-quenching studies using iodide and acrylamide as external quenchers. Thus, while by the addition of iodide the tryptophan fluorescence of unliganded CPK is reduced to about 75% of the unquenched control, no such effect is manifested upon addition of this quencher to the CPK.ADP and CPK.ATP complexes. Similarly, the relative effectiveness of quenching of the CPK-coenzyme complexes by acrylamide is only about 60% of that measured in the unliganded enzyme. Both these data and the spectral characteristics of the quenched fluorescence suggest that coenzyme binding perturbs a tryptophan residue that is close to the active site and that is partially exposed to the solvent. The differential effectiveness of external quenchers on unliganded and liganded CPK allows the determination of the ligand binding equilibria by fluorescence-quenchability titration.(ABSTRACT TRUNCATED AT 250 WORDS)