Impaired control of visual attention in schizophrenia.

To investigate attentional impairment in schizophrenia, the authors examined the performance of 22 patients with schizophrenia and 16 healthy control subjects in 4 visual search tasks that varied in perceptual requirements and in the need for precise attentional control. The rate of search was slowed in the patients in all tasks. However, the degree of slowing was largest in tasks requiring precise attentional control and smallest in tasks that were perceptually difficult but required less attentional control. This pattern of results indicates that the primary impairment of attention in schizophrenia lies in the control of attention and not in the selection processes that operate once attention has been directed to an object. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Primary leiomyosarcoma of the fallopian tube

Chronic renal failure occurs in about 20% of long-term survivors treated with bone marrow transplant (BMT) regimens that include total-body irradiation (TBI); this syndrome is called BMT nephropathy. In a previous study in a syngeneic rat BMT model it was shown that captopril (an inhibitor of angiotensin-converting enzyme) could be used to treat experimental BMT nephropathy. Current studies were designed to determine whether captopril could also be used to prevent BMT nephropathy. Rats received 14 to 18.5 Gy TBI in six fractions over 3 days followed by syngeneic BMT. Seven days before TBI half the rats were started on captopril (500 mg/liter in the drinking water). Blood urea nitrogen, ratios of urine protein to creatinine, serum creatinine, and blood pressure were used to assess renal function. In animals receiving TBI alone, BMT nephropathy developed 3 to 6 months after transplant. At 6 months after TBI, captopril-treated animals had lower systolic blood pressure and better-preserved renal function than animals receiving TBI alone, with dose-modifying factors of about 1.3. The captopril treatment had no effect on bone marrow ablation by TBI. Captopril appears to be safe and effective in the prophylaxis of BMT nephropathy.     

Magnetic resonance imaging in the staging of solitary plasmacytoma of bone

PURPOSE: To assess prospectively the role of magnetic resonance (MR) imaging in the staging of patients with a solitary bone plasmacytoma (SBP). PATIENTS AND METHODS: Twelve consecutive patients with an apparent SBP underwent MR imaging of both the primary tumor and the thoracic and lumbosacral spine to seek additional foci of marrow involvement that might have been undetected by standard skeletal survey. All patients received megavoltage irradiation (total dose, 40 Gy) to the primary lesion. RESULTS: MR imaging of the thoracic and lumbosacral spine showed additional foci of marrow replacement in four of 12 patients, with signal characteristics identical to those of the primary tumor. In all four patients, the abnormal protein persisted at greater than 50% of the pretreatment value following radiation treatment. In contrast, the myeloma protein disappeared or was reduced by greater than 50% in five of the six patients with secretory disease and without additional marrow abnormalities. One of four patients progressed to multiple myeloma 10 months after diagnosis with new lesions on conventional radiographs in the same areas as detected previously by MR imaging. CONCLUSION: Four of 12 patients considered to have a SBP by standard criteria may have been understaged, because MR imaging showed additional marrow abnormalities consistent with myeloma. MR imaging of the spine may contribute to the initial staging of SBP, especially since some patients may be cured with radiotherapy.     

Effect of pentobarbital on normal brain protection and on the response of 9L rat brain tumor to radiation therapy

The authors attempted to confirm published reports that pentobarbital protects against radiation-induced damage to normal rat brain, as well as enhances radiotherapeutic efficacy in a rat brain tumor model. They evaluated animal survival in 9L gliosarcoma-burdened rats that received whole-brain radiation therapy (16, 24, 32, or 40 Gy) while under intraperitoneal pentobarbital (60 mg/kg) or intramuscular ketamine (60 mg/kg) sedation. The animals were examined at autopsy to attribute death to either intracranial tumor growth or normal brain toxicity in the absence of discernible tumor. There was no difference between the two anesthesia groups regarding the survival of unirradiated animals. Radiation therapy produced a significant dose-dependent prolongation in animal survival, which was limited by the development of normal tissue toxicity at the higher doses. When compared to ketamine anesthesia, pentobarbital anesthesia appeared to offer some protection (not statistically significant) against early (but not late) toxicity at selected radiation doses. A reduction in the number of deaths from tissue toxicity suggested an increased antitumor effect, but again this was not statistically significant. Only in one case was there even a marginal significant difference (p = 0.045) between overall therapeutic efficacy in rats sedated with pentobarbital versus ketamine. While there may be a radioprotective effect of pentobarbital in rat brains without intracranial tumor, there is no conclusive evidence for either radioprotection or significant improvement of radiotherapeutic efficacy in this 9L rat brain tumor model.     

Facilitating outpatient treatment entry following detoxification for injection drug use: A multisite test of three interventions.

A multisite, randomized trial within the National Drug Abuse Treatment Clinical Trials Network (CTN) was conducted to test 3 interventions to enhance treatment initiation following detoxification: (a) a single session, therapeutic alliance intervention (TA) added to usual treatment; (b) a 2-session, counseling and education, HIV/HCV risk reduction intervention (C&E), added to usual treatment; and (c) treatment as usual (TAU) only. Injection drug users (n = 632) enrolled in residential detoxification at 8 community treatment programs were randomized to 1 of the 3 study conditions. TA participants reported entering outpatient treatment sooner and in greater numbers than TAU participants. Reported treatment entry for C&E fell between TA and TAU with no significant differences between C&E and the other conditions. There were no differences among the interventions in retention, as measured by weeks of outpatient treatment for all participants who reported treatment entry. Alliance building interventions appear to be effective in facilitating transfer from detoxification to outpatient treatment, but additional treatment engagement interventions may be necessary to improve retention. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Towards ultrathick battery electrodes: aligned carbon nanotube-enabled architecture

Vapor deposition techniques were utilized to synthesize very thick (～1 mm) Li-ion battery anodes consisting of vertically aligned carbon nanotubes coated with silicon and carbon. The produced anode demonstrated ultrahigh thermal (>400 W·m(-1) ·K(-1)) and high electrical (>20 S·m(-1)) conductivities, high cycle stability, and high average capacity (>3000 mAh·g(Si) (-1)). The processes utilized allow for the conformal deposition of other materials, thus making it a promising architecture for the development of Li-ion anodes and cathodes with greatly enhanced electrical and thermal conductivities.     

Fractography as well as fatigue and fracture of 25 wt% silicon carbide whisker reinforced alumina ceramic composite

Fatigue cracked and fast fractured regions in four-point bend specimens prepared from 25 wt% silicon carbide whisker reinforced alumina composite were examined by scanning electron microscopy. This composite was found to be susceptible to a fatigue crack growth phenomenon similar to that in the case of metallic materials, but with a higher crack growth exponent. In the fatigue region, the alumina matrix failed mainly in a transgranular mode and the whiskers mainly failed with a flat fracture surface but without their pullout. On the other hand, in the fast fracture region, the whiskers failed predominantly by pullout and the alumina matrix failed in a mixed mode with about half in transgranular and the other half in intergranular mode. Thus, to improve the fracture toughness of the material, the grain boundary strength of alumina and the matrix whisker interfacial bonding should be improved. To increase the resistance to fatigue, the fracture strength of the alumina grains should be improved by using finer α-alumina particles and the fatigue strength of the whisker have to be increased by improving the uniformity in distribution of β-SiC whiskers during hot pressing.     

Three DNA sequencing methods using capillary gel electrophoresis and laser-induced fluorescence.

Capillary gel electrophoresis is demonstrated for the four-spectral-channel sequencing technique of Smith, the two-spectral-channel sequencing technique of Prober, and the one-spectral-channel sequencing technique of Richardson and Tabor. Sequencing rates up to 1000 bases/h are obtained at electric field strengths of 465 V/cm. At lower electric field strengths, capillary electrophoresis produces useful data for fragments greater than 550 nucleotides in length with 2 times better resolution than slab gel electrophoresis. An on-column detector produces detection limits of 200 zmol (1 zmol = 10(-21) mol = 600 molecules) for the four-spectral-channel technique. A postcolumn detector, based on the sheath flow cuvette, produces detection limits of 20 and 2 zmol for the two- and one-spectral-channel techniques, respectively.     

Intact attentional control of working memory encoding in schizophrenia.

This study reports evidence that individuals with schizophrenia (SC) demonstrate intact attentional selection for visual working memory (WM) storage. A group of 62 participants with SC and 55 control participants without SC were studied in a series of 5 experiments that examined the ability to use top-down and bottom-up cues to guide WM encoding, as well as the ability to spontaneously select a subset of representations for storage. Participants with SC exhibited a consistent and robust ability to use selective attention in the control of WM in all 5 experiments, demonstrating a remarkable island of preserved functioning given the broad spectrum of impairments of attention and WM that have been widely reported in those with SC. These findings indicate that attention is not globally impaired in SC and make it possible to delineate more precisely the nature of the specific impairment of attention in this disorder. (PsycINFO Database Record (c) 2010 APA, all rights reserved)