Helios: A 15 TW carbon dioxide laser-fusion facility

Helios is an eight-beam carbon dioxide laser and target facility for the study of laser-fusion processes. The design of file laser is based on the principle of the electron-beam controlled high-pressure electrical discharge. The eight beams deliver a total of 9 kJ to targets in subnanosecond pulses and the peak intensity at focus exceeds 10¹⁶W/cm²/beam. The laser can be fired at 5 min intervals but the system shot rate is restricted to 2/h because of target insertion, alignment, and preparation of diagnostic systems.     

Craig-Scott orthosis: a biochemical and functional evaluation

The Craig-Scott double upright knee ankle orthosis was subjected to a biomechanical evaluation which included analysis of the force interaction with the supported limb and a functional evaluation. The results were compared with data previously determined from biomechanical evaluations of other common orthoses. In the Craig-Scott design, the single application of the knee stabilizing force below the knee concentrates this force in a relatively small bony area, sometimes exceeding tolerance. This might be avoided by using a tibial closure with patellar tendon bearing features. The design was found to produce relatively low anatomic knee shear. In functional aspects such as donning, doffing, transfers and ambulation, the orthosis is essentially equivalent to other double upright designs. The rigidity of the orthosis with only a tibial band closure and a bail connecting the uprights was determined to be adequate. The limited number of bands and closures provides some advantages in reduced donning and doffing time; however, in the absence of posterior closures below the knee, the orthosis had a tendency to slide forward off the leg when transferring. This disadvantage was eliminated by adding a soft posterior closure below the knee, which produced a minimal increase in donning and doffing times.     

Effect of excess thymidine on the growth of human melanoma cells transplanted in thymus deficient nude mice

The effect of thymidine (TdR) on the growth of a human melanoma transplanted in nude mice has been studied. It was found that the injection of 1 g/kg/h of TdR for at least 72 h is sufficient to suppress the growth of the melanoma cells. This inhibition lasts for the duration of the treatment, and causes no apparent toxicity to the host. Nude mice treated for 6--9 days with TdR survived 158 days after melanoma transplant versus 126 days for the controls.     

Diagnosis of prostatic carcinoma: value of random transrectal sonographically guided biopsies

OBJECTIVE: We studied the efficacy of random, transrectal sonographically guided biopsies in the diagnosis of prostatic carcinoma in a high-risk population. SUBJECTS AND METHODS: During a 2-year period, 570 transrectal sonographically guided prostatic biopsies were done because of clinical findings suggestive of prostatic carcinoma. Biopsies of hypoechoic lesions that were suggestive of carcinoma and segmental random biopsies of normal-appearing lobes of the prostate were performed. Transrectal sonographic findings were correlated with results of pathologic examination of the biopsy specimen and with surgical results, when available. RESULTS: Of the 202 patients found to have carcinoma, the carcinoma was detected with directed biopsy in 145 patients (72%). One hundred twenty (71%) of 169 carcinomas were detected with random biopsy when that procedure was performed. Random biopsies were the only method of diagnosing 57 (28%) of the 202 carcinomas, increasing the yield by 39%. CONCLUSION: Yield of carcinoma on transrectal sonographically guided biopsies increases significantly when segmental random biopsies are performed. Transrectal sonographically guided biopsies should include cores through hypoechoic lesions that are suggestive of carcinoma and bilateral segmental random biopsies.     

Teaching preschool children with disabilities to respond to the lures of strangers

An investigation was conducted to determine the effectiveness of a constant-time-delay procedure used in combination with multiple exemplars of strangers, lures, and sites to teach a generalized response to the lures of strangers to four preschool children with disabilities. Although the correct response was quickly acquired in the training site, the response failed to generalize to the probe sites until training was conducted in vivo. Instruction in vivo resulted in acquisition, maintenance, and generalization of the response to strangers' lures. Generalization occurred across probes with novel exemplars of lures, strangers, and sites.     

A somatodendritic distribution of Rab11 in rabbit brain neurons

Comparisons of subcellular targeting in neurons and epithelial cells have led to suggestions that apical epithelial antigens localize to axons and nerve terminals. We have studied the distribution in brain of the small GTP-binding protein, Rab11, which is localized to apical vesicular populations in epithelial cells. Sections of rabbit brain were examined by immunohistochemistry using a monoclonal antibody against rabbit Rab11. Rab11 immunoreactivity was present exclusively in neurons. In all regions examined, including forebrain, cerebellum, thalamus and brainstem, Rab11 immunoreactivity was observed in cell bodies and dendrites. No staining was observed in hippocampal neurons. These results indicate that the distribution of Rab11 does not support previous suggestions that apical epithelial markers should localize to axons and synaptic endings.     

Influence of subchronic exposure to lindane on humoral immunity in mice

Lindane suppressed both primary and secondary antibody responses to sheep red blood cell (SRBC) in albino mice, the effects being more pronounced on the secondary than the primary response. However, a longer duration of pesticide exposure induced similar degrees of immunosuppression on both responses. The sequential study of plaque forming cells (PFC) kinetics revealed that suppression of plaque formation not only occurred at peak days but also on pre and post peak days, and there was no delay in peak antibody formation. Moreover, reduction in the primary PFC was not associated with decrease in the antibody response to SRBC. The results indicate that lindane suppresses both primary and secondary humoral immune responses in a time and dose dependent manner, and suggest a threshold susceptibility to exposure.     

Controlled reopen suture technique for pyloric exclusion

The aim of this prospective, randomized study was to investigate the possibility of performing pleurodesis using a small percutaneous catheter (Cystofix catheter, CH10, 65 cm) inserted at bedside in patients with recurrent malignant pleural effusion and to compare this catheter with a conventional large bore chest tube (CH24) placed in connection with diagnostic thoracoscopy. After drainage pleurodesis was performed with tetracycline as sclerosing agent. Of 18 evaluable consecutive patients (mean age 67.8 years) nine were randomized for pleurodesis with the small and nine for the large catheter. In the former group, the majority (seven of nine) did not find insertion of the catheter more unpleasant than thoracentesis. In the latter group only a few (two of nine) found insertion comparable with thoracentesis (P < 0.05). All patients found the presence of the large catheter very or somewhat unpleasant (two and seven patients), whereas this was only the case for a few (no and two patients) treated with the small catheter (P < 0.05). In the former group three patients required new thoracentesis, whereas this was only the case for two patients in the latter group (P > 0.05). No complications were seen. We conclude that pleurodesis in patients with recurrent malignant pleural effusion can be performed with a small percutaneous catheter (Cystofix) with an effect similar to that obtained with a large-bore chest tube and with less discomfort for the patient.