Detection of airborne carbon nanotubes based on the reactivity of the embedded catalyst

A previously described method for detecting catalyst particles in workplace air((1,2)) was applied to airborne carbon nanotubes (CNT). It infers the CNT concentration indirectly from the catalytic activity of metallic nanoparticles embedded as part of the CNT production process. Essentially, one samples airborne CNT onto a filter enclosed in a tiny chemical reactor and then initiates a gas-phase catalytic reaction on the sample. The change in concentration of one of the reactants is then determined by an IR sensor as measure of activity. The method requires a one-point calibration with a CNT sample of known mass. The suitability of the method was tested with nickel containing (25 or 38% by weight), well-characterized multi-walled CNT aerosols generated freshly in the lab for each experiment. Two chemical reactions were investigated, of which the oxidation of CO to CO2 at 470°C was found to be more effective, because nearly 100% of the nickel was exposed at that temperature by burning off the carbon, giving a linear relationship between CO conversion and nickel mass. Based on the investigated aerosols, a lower detection limit of 1 μg of sampled nickel was estimated. This translates into sampling times ranging from minutes to about one working day, depending on airborne CNT concentration and catalyst content, as well as sampling flow rate. The time for the subsequent chemical analysis is on the order of minutes, regardless of the time required to accumulate the sample and can be done on site.

[Cognitive-psychoeducational group programme for bipolar disorder: pilot study with two-year follow-up]

52 patients with bipolar disorder were treated with psychopharmacotherapy and a cognitive psychoeducational group programme that was established at the Department of Psychiatry and Psychotherapy of the Ludwig Maximilian University, Munich, Germany. The programme covers psychoeducation, identifying and coping with depressive and manic symptoms, relapse prevention and establishing a stable life style. 96 % rated the group to be helpful and felt well informed about their illness. There were significant gains in knowledge (F = 25,714, p < 0.001) and improvements in the severity of the illness (CGI; F = 68,255, p < 0.001) post-treatment. With regard to sociodemographic and clinical variables, only the level of work qualification showed a differential treatment response: patients with higher qualifications had a more favourable course of the illness (F = 4,125, p = 0.048). At one and two year follow-up 25 % and, respectively, 30 % of the sample had to be readmitted. A higher number of previous hospitalisations (p = 0.010) and male sex (p = 0.031) turned out to be significant predictors of relapse (R² = 0.358, p = 0.004) at two year follow-up. This disorder-specific group programme represents a key component of treatment offering emotional support for patients and their relatives. Patients are to be involved in the treatment process and need information about the illness, its psychosocial and pharmacological treatment as well as help in learning practical skills to improve their living with the disease. Being integrated and committed to a supporting network may increase their quality of life.

[Psychotherapeutic interventions in bipolar disorders--treatment programmes, their contents and effectiveness]

Cognitive-behavioural interventions combined with pharmacotherapy have gained importance in the treatment of bipolar disorders. Based on the vulnerability-stress instability model psychoeducational, cognitive-behavioural, interpersonal and family interventions are provided. This paper gives an overview of treatment programmes and their foci. They include providing knowledge about the illness and its treatment, modifying dysfunctional cognitions and symptom management as well as relapse prevention by promoting a stable life style. There are several English- and German-based randomised controlled follow-up studies in English-speaking countries which provide support for the efficacy of combined treatment. Since 2004 German-based manualised treatment programmes have become available and have been shown to be clinically feasible and promising.

[Concomitant injuries after upper ankle joint dislocations]

Functional treatment with the Air Stirrup Ankle Brace recommended by C. N. Stover in 1979 can reduce pathological inversion of the ankle joint. In our retrospective study of 109 patients treated by this kind of ankle brace we found 96 patients (88%) with excellent results. Only 13 patients (12%) reported moderate to good results. To detect and characterize their painful conditions of ankles we did a clinical, radiological and MRI-Investigation. In only 2 cases we found a moderate instability after clinical investigation, anterior stress roentgenogram and talar tilt. By using the MRI-investigation 1.0 Tesla with a 512 x 360 Matrix we could find 10 cases with osteochondral lesions of the ankle. In 7 cases there was separated ossicle in the fibulotalar joint, in 1 case we detected a fracture of the processus anterior tali, in another case we could see a posttraumatic lesion of the talus and calcaneus with bone bruise and at least one osteochondral fracture of the distal tibia. The capability of the MRI to detect particularly osteo-chondral lesions of the talus and the tibiofibular joint was shown in 10 of 13 cases. Therefore we recommend to do an MRI-investigation on all patients after ankle sprain if there are painful conditions within the ankle after conservative treatment.

MAG3 renal transplant tomography SPECT with a non-SPECT agent

The authors encountered a renal transplant patient in whom tubular stasis permitted sufficient time to perform SPECT using Tc-99m MAG3. SPECT revealed a defect that was not apparent on the planar study. Renal biopsy showed acute vascular rejection. On a subsequent Tc-99m MAG3 SPECT study the defect had resolved.

[A cerebral air embolism due to a central venous catheter in the computed tomogram]

A case of air embolism to the brain occurred via a disconnected central venous catheter. Computed tomography disclosed a number of small air bubbles in the right hemisphere. If the clinician suspects air embolism a CT scan should be obtained immediately to verify the presence of intracerebral air. On later CT scans only secondary effects like in any embolism will be seen.

Bone mineral content after renal transplantation. Placebo-controlled prospective study with 1,25-dihydroxy vitamin D3

Forearm bone mineral content (BMC), as evaluated by photonabsorption densitometry, was measured in 28 cadaver kidney donor recipients who entered the study 8 weeks postoperatively and were followed up for 18 months. BMC decreased significantly (p less than 0.05) but marginally in placebo-treated patients (n = 14) (initial BMC 1.09 +/- 0.25 g/cm; final BMC 1.05 +/- 0.24). Fourteen patients were prophylactically given 1,25(OH)2 vitamin D3 in a dose which avoided hypercalcemia and hypercalciuria (approximately 0.25 microgram/day); under 1,25(OH)2 vitamin D3 prophylaxis a significant decrease of forearm BMC was observed no longer (initial BMC 0.94 +/- 0.21 g/cm; final BMC 0.95 +/- 0.21), but the difference between placebo and 1,25(OH)2 vitamin D3 narrowly missed statistical significance (p = 0.066). It is concluded that the decrease of forearm BMC is negligible in transplant recipients with low steroid regimens. The data suggest a trend for prophylaxis with 1,25(OH)2 vitamin D3 to slightly ameliorate forearm (cortical) BMC loss.