Brain scintigraphy (SPECT) with thallium-201 in primary brain tumors]

We evaluated the role of thallium-201 single-photon emission-computed tomography (SPECT) in diagnosis, differential diagnosis and follow-up of 33 patients with primary brain tumors. 27 of 33 lesions were detectable by Tl-201 SPECT because only two of eight low-grade (grade 1 and 2) astrocytomas showed Tl-201 accumulation up to a tumor to nontumor ratio of 2.6. High grade (grade 3 and 4) astrocytomas showed Tl-201 accumulation in the range of 2.2 up to 13.0 and were different from low-grade astrocytomas. Noninvasive grading of astrocytomas is therefore possible, whereas differential diagnosis of oligodendrogliomas and astrocytomas or meningiomas was not possible with Tl-201. In the follow-up of six patients, we could demonstrate, that tumor progression is correlated with increasing and tumor regression with decreasing Tl-201 accumulations. This functional changing proceed morphological findings in CT. But vanishing of Tl-201 accumulation during therapy does not mean vanishing of tumor as could be demonstrated by follow-up.     

FASCIOCUTANEOUS ISLAND FLAPS FOR ORTHOPAEDIC MANAGEMENT IN LOWER LIMB RECONSTRUCTION USING DERMATOMAL PRECINCTS

This paper describes a technique of fasciocutaneous island flaps used in reconstruction of the lower limb. It is very versatile and some 26 individual flaps in 22 patients have been used to reconstruct skeletal and soft tissue problems from the popliteal fossa to the ankle joint. These longitudinally designed flaps made up of a trilaminate of skin, subcutaneous fat and fascia are aligned within the dermatomal precincts. The most important location for such flap design is along the peroneal compartment sitting within the L5 dermatome and incorporating the superficial peroneal nerve. It can be lengthened as far as the lateral malleolus and is an excellent reconstructive method to close defects over the lower third of the tibia. The medial compartment of the leg employing the saphenous nerve (L4 dermatome) is another area for fasciocutaneous island flap reconstruction, but use is restricted to the upper two-thirds of the tibial area. Posteriorly the island flap design sits along the S2 dermatome, this time incorporating the sural nerve to reconstruct defects of the calf and can be extended to include problems of the popliteal fossa. In the overall flap technique, the age of the patient is not a contraindication and cases with peripheral vascular disease have been treated successfully. The flaps may extend up to a 5:1 ratio in dimension. The operating time can be considerably shortened.     

Passive Pneumatic Stabilization Device for Assisting in Reduction of Femoral Shaft Fractures

Abstract During treatment of femoral shaft fractures, not only the actual fracture reduction but also the retention of the achieved reduction is essential. Substantial forces may apply to the bone fragments, due to multidirectional muscular contraction. Furthermore, forces from manipulation of one bone fragment may be transferred over the soft tissues onto the other fragments, thus hindering accurate fracture reduction. Once a sufficient reduction has been achieved, this position must be retained whilst definitive internal fixation is performed. Conventional methods comprise mounting patients on a traction table and applying manual distraction or employing special distraction devices, such as the AO distractor device. These approaches, however, only insufficiently stabilize both main fragments. For example, on the traction table the proximal femoral fragment can pivot around the hip joint thus complicating precise reduction. A novel pneumatic stabilization device to assist surgeons during operative procedures is described. This passive holding device “Passhold” connects to one main fragment through a minimally invasive bone interface and statically locks the fragment’s position. Thereafter, only the other main fragment is manipulated to achieve reduction. Mutual interference of the reciprocal fragment positions, due to soft-tissue force transfer during manipulation, is avoided. The authors examined the stability of the novel retention device on a test rig and proved its functionality under sterile settings using cadaver tests. It is concluded that this device largely facilitates the operative procedure in femoral shaft fractures, is sufficiently stable and ergonomically suitable for intraoperative deployment.     

Acute radiation reactions in oral and pharyngeal mucosa: tolerable levels in altered fractionation schedules.

PURPOSE:To investigate whether a predictive estimate can be obtained for a 'tolerance level' of acute oral and pharyngeal mucosal reactions in patients receiving head and neck radiotherapy, using an objective set of dose and time data. MATERIALS AND METHODS:Several dozen radiotherapy schedules for treating head and neck cancer have been reviewed, together with published estimates of whether they were tolerated or (in a number of schedules) not. Those closest to the borderline were given detailed analysis. Total doses and biologically effective doses (BED or ERD) were calculated for a range of starting times of cellular repopulation and rates of daily proliferation. Starting times of proliferation from 5 to 10 days and daily cellular doubling rates of 1-3 days were considered. The standard published form of BED with its linear overall time factor was used: BED=nd(1 + d/(alpha/beta) - Ln2(T - T(k))/alpha T(p) (see text for parameters). RESULTS: A clear progression from acceptable to intolerable mucosal reactions was found, which correlated with total biologically effective dose (BED in our published modeling), for all the head and neck cancer radiotherapy schedules available for study, when ranked into categories of 'intolerable' or 'tolerable'. A review of published mechanisms for mucosal reactions suggested that practical schedules used for treatment caused stimulated compensatory proliferation to start at about 7 days. The starting time of compensatory proliferation had little predictive value in our listing, so we chose the starting time of 7 days. Very short and very long daily doubling rates also had little reliability, so we suggest choosing a doubling time of 2.5 days as a datum. With these parameters a 'tolerance zone of uncertainty' could be identified which predicted acute-reaction acceptability or not of a schedule within a range of about 2-10 Gy in total BED. If concurrent chemoradiotherapy is used, our provisional suggestion is that this zone should be reduced by up to roughly 3-5 Gy10 in BED, with a request for further evidence. CONCLUSIONS:It is suggested that total BED should be used, as specified above. Parameters of alpha=0.35 Gy-(1), alpha/beta=10 Gy, Tk=7 days and Tp=2.5 days are suggested. The 'acute/ tolerance zone' then turns out to be 59-61 Gy10 for radiation-only treatments. Further information about the decrement caused by concurrent head-and-neck cancer chemoradiotherapy, possibly 3-5 Gy10, is required.     

Electrophysiological characterization of a novel potent and orally active NMDA receptor antagonist: CGP 37849 and its ethylester CGP 39551

The selectivity and potency of the novel competitive N-methyl-D-aspartate (NMDA) receptor antagonists, CGP 37849 and CGP 39551, were investigated in vitro and in vivo using electrophysiological approaches. Like the reference blocker DL-AP5, both compounds acted in vitro (hippocampus, substantia nigra, spinal cord) to antagonize the excitatory actions of exogenously administered NMDA as well as the synaptically elicited, physiological NMDA receptor responses in hippocampus and spinal cord. In all isolated preparations CGP 37849 was more potent than CGP 39551, and 5- to 10-fold more potent than DL-AP5. Neither compound showed any marked effect on responses evoked by quisqualate and kainate. NMDA excited dopaminergic cells in the pars compacta region of the substantia nigra in a concentration-dependent manner. This effect also could be selectively antagonized by CGP 37849 and CGP 39551. In the anaesthetized rat, excitatory responses of hippocampal pyramidal cells evoked by iontophoretic application of NMDA were antagonized by CGP 37849 and CGP 39551 following their oral administration without reducing quisqualate or kainate responses. In contrast to the in vitro situation, CGP 39551 was more potent than CGP 37849 in vivo. Effective doses were 30 mg/kg p.o. for CGP 39551 and 100 mg/kg p.o. for CGP 37849. In conclusion, it is demonstrated that CGP 37849 and CGP 39551 selectively antagonize NMDA evoked neuronal responses in vivo and in vitro and that the drugs are centrally active following their oral administration.     

New perspectives of avalanche disasters. Phase classification using pathophysiologic considerations]

This study comprises an analysis of the data on 332 persons totally buried by avalanches in Switzerland between 1981 and 1989. The survival rate was calculated with the aid of a computer-assisted estimation procedure according to Turnbull. The curve pattern was interpreted according to pathophysiological considerations, on the basis of which the time course of the battle for survival was divided into 4 phases: 1) Survival phase: until 15 minutes after burial under the snow masses. The survival probability amounts to 93% and is, thus, higher than so far assumed. Almost all those buried survived this period of the time provided they were not fatally injured and received first aid. 2) Asphyxia phase: duration of burial under the avalanche from 15 to 45 minutes. The probability of survival sank dramatically during this period from 93% to about 25% (fatal kink of the survival probability curve). Those buried under the snow without an air pocket die of acute asphyxia (the point of no return) and the mortality rate reaches its maximum in this phase. 3) Latent phase: the period as from 45 minutes following the avalanche until the time of rescue. This phase is survived only in the presence of an air pocket. With sufficient oxygen reserves and freedom of thoracic movement a "phase of relative safety" occurs, whereby the survival probability diminishes further only slowly. The first deaths due to hypothermia arise after 90 minutes. 4) Rescue phase: from the time of extrication from the snow until arrival in hospital. There is an increased risk of a fatal outcome during the rescue procedure and immediately afterwards through augmented hypothermia.(ABSTRACT TRUNCATED AT 250 WORDS)