Intrusions in Alzheimer's disease in immediate and delayed memory as a function of presentation modality

Young and elderly participants, and participants with Alzheimer's disease (AD) were compared via the suffix paradigm, where a not-to-be-recalled item is appended onto sequences to be immediately recalled. This task was followed by delayed tasks. In immediate recall, AD subjects showed both extralist and suffix intrusions. Recall of auditorily as compared with visually presented stimuli was superior, with the difference increasing in older subjects. The auditory but not the visual suffix produced an end-of-sequence decrement, which was greater in AD than in other groups. After delay, the elderly and young showed virtually perfect performance. The AD participants showed relatively high performance; however, extralist intrusions were frequent, resulting in a relatively low hit rate. As in immediate recall, intrusions showed specificity for AD, and in this paradigm appeared to be a marker differentiating AD and normal subjects. However, the sample size limits the power and generalizability of these findings.     

Follicular thyroid cancer

Follicular thyroid cancer is the second most common thyroid malignancy after PTC. There are marked geographical variations in the relative proportions of FTC and PTC, most likely related to dietary iodine content. In iodine-deficient areas, the relative rate of FTC tends to be increased. Other risk factors for FTC include age over 50 years and female sex. Genetic factors may also have a role in determining disease susceptibility but remain ill-defined. Histologically, FTC is characterized by follicle formation and the absence of any papillary elements in the tumor. Differential diagnosis from a benign adenoma can be difficult. The degree of vascular invasiveness seems to correlate with tumor aggressiveness, and two histologic subtypes, oxyphilic FTC and insular FTC, may be associated with increased morbidity and mortality. Primary treatment for FTC is complete surgical tumor removal. Extensive bilateral surgery beyond this goal may not confer additional benefit but can facilitate adjuvant treatment and follow-up. Postoperative levothyroxine treatment is almost universally used, and patients deemed at high risk of recurrence may benefit from radioiodine remnant ablation. Treatment of metastatic disease involves operation, radioiodine, and, in selected cases, external beam radiation and chemotherapy. Prognosis for patients with metastatic disease is guarded, but most other patients have good outcomes comparable to that in PTC. For nonoxyphilic FTC, high-risk features other than initial metastases include advanced age, locally extensive disease, and the presence of marked angioinvasion. In oxyphilic FTC, DNA aneuploidy is also important. Follow-up should be most intense during the first 5 years after primary treatment and needs to be tailored to the patient's risk of disease progression. For patients at low risk of recurrence (young, small lesions, minimally invasive tumor), serum thyroglobulin measurements may largely suffice, whereas higher risk patients with elevated serum thyroglobulin levels and patients with significant titers of interfering anti-thyroglobulin autoantibodies may also need to undergo periodic diagnostic radioiodine scanning.     

Pollen of a male-sterile mutant of Arabidopsis thaliana isolated from a T-DNA insertion pool is not effectively released from the anther locule

We have isolated a male-sterile mutant from a pool of T-DNA insertional lines of Arabidopsis thaliana generated by an in planta transformation procedure [Chang et al. (1994) Plant J. 5: 551]. Pollen in this mutant is not effectively released from anther locules after cleavage of the stomium. Most mutant pollen grains are round, in contrast to the tricolpate wild-type pollen, and some pollen grains show an abnormal surface structure. Manually released mutant pollen grains are not fertile and show defects in pollen tube germination in vitro. Genetic analysis disclosed that this lesion is due to a single recessive nuclear mutation located on chromosome 3 closely linked to the gll locus. The mutation locus is tightly linked to the inserted T-DNA.