Fine-needle aspiration cytology of lobular carcinoma in situ

Fine-needle aspiration cytology (FNAC) plays a key role in the preoperative diagnosis of breast carcinoma but is less reliable in the diagnosis of in situ lesions. The objective of the present study was to investigate the cytological features of lobular carcinoma in situ (LCIS), regarding which little data is available to date. Cytological features of FNAC of the breast from 21 patients with histology-proven LCIS were described and compared with surgical specimens. Aspirates from 8/21 cases had cell groups diagnostic for or compatible with LCIS. Aspirates from an additional two cases demonstrated hypercellular, dissociated, and more pleomorphic tumor cells, which were originally diagnosed as invasive lobular carcinoma (ILC). The remaining 11 aspirates were diagnosed as benign or nondiagnostic. FNAC from the eight diagnostic specimens were characterized by loosely cohesive cell groups composed of uniform cells with occasional intracytoplasmic lumina, slightly irregular and eccentric nuclei. We conclude that the main difficulty in diagnosing LCIS by FNAC is sampling rather than recognition of the lesions. However, one should be aware of the cytological features of LCIS in order to reach a correct diagnosis. There are no reliable cytological criteria that help in differentiating pleomorphic and dissociated LCIS from ILC.     

Effects of conditioned stimulus pre-exposure on human electrodermal conditioning to fear-relevant and fear-irrelevant stimuli

The effects of conditioned stimulus (CS) pre-exposure and fear-relevance of the CS on human Pavlovian electrodermal conditioning were investigated. A differential delayed conditioning paradigm was used with a CS-unconditioned stimulus (US; shock) interval of 8 s. In Experiment 1, 64 subjects were randomized into four groups, two of which received fear-relevant stimuli and the other two fear-irrelevant stimuli. Half of the subjects were pre-exposed to the to-be-CSs and the other half to two not-to-be-CSs, with 15 exposure of each stimulus. During acquisition, subjects received 8 reinforced and 8 nonreinforced CS+ and CS- trials, and during the extinction phase 15 nonreinforced trials of each CS. Pre-exposure to the to-be-CSs retarded conditioning for the first and second interval anticipatory responses (FIRs and SIRs); that is, a latent inhibition effect was demonstrated, although the results for the FIR were inconclusive. The expected effects of fear-relevance were not revealed. Experiment 2 addressed the question whether the long pre-exposure period interfered with the frequently observed "preparedness effect" of higher resistance to extinction to fear-relevant stimuli. The design was similar to that of Experiment 1, but for half of the subjects the acquisition phase was initiated immediately after a short rest period, and for the other half acquisition started after an extended rest period, equal to the duration of the pre-exposure phase in Experiment 1. Twenty extinction trials of each CS were presented. A reliable difference in arousal in terms of spontaneous fluctuations was produced by the rest periods, but although differential conditioning was observed, no effect of fear-relevance was seen during extinction.     

A simple statistical model for prediction of acute coronary syndrome in chest pain patients in the emergency department

Background  

Several models for prediction of acute coronary syndrome (ACS) among chest pain patients in the emergency department (ED) have been presented, but many models predict only the likelihood of acute myocardial infarction, or include a large number of variables, which make them less than optimal for implementation at a busy ED. We report here a simple statistical model for ACS prediction that could be used in routine care at a busy ED.     

Decline in visual attention and spatial memory in aged rats

The present study was a longitudinal study of age-related changes in performance of the 5-choice serial reaction time task, a test of visual attention. Following acquisition of the task, animals were tested on two occasions on their ability to perform the 5-choice task. In Test 1 (Young: 7 months; Aged: 13–14 months) no age-related effects on baseline performance were revealed. However, increasing the attentional load of the task revealed an impairment in choice accuracy by animals of the Aged group. In Test 2 (Young: 10–11 months; Aged 23–24 months), animals of the Aged group were significantly impaired on the baseline schedule of the task compared to the Young group. The deficit in accuracy on the task could be improved in the Aged animals by decreasing the attentional load. The results of the present study suggest a deficit in attentional function as a result of the aging process, markedly similar to that observed following lesions of the basalo-cortical cholinergic system.     

In vitro appearance of large human histamine-containing basophilic cells

The appearance of large human basophilic cells containing histamine was followed to reflect cell maturation in cultures of peripheral blood leukocytes. Aliquots were taken on day 0 and after 7, 9-10 and 14 days in culture, and the basophilic cell numbers were determined in 200 microliter cytospin specimens stained with Wright's stain. The number of small basophils initially present declined during the culture period. The number of spontaneously appearing large basophilic cells varied among the cultures from different individuals and was slightly, though not significantly, higher in atopic individuals than in normals. In cultures of cells from atopic individuals, the number of large basophilic cells was reproducibly increased by the addition of appropriate allergen to the cultures. In cultures of cells from normal individuals, the number was increased two- to six-fold by adding conditioned medium (CM), either from 3-day cultures of cells from atopic individuals stimulated with allergen or with CM from the Mo T cell leukemic line. The addition of mitomycin C decreased the number of large basophilic cells and cycloheximide abrogated their appearance.     

Familial occurrence of histiocytosis.

The clinical and histological findings of four children with lethal histiocytosis are reported. The children belonged to two sibships and originated from a Swedish geographical isolate. Consanguinity between the parents was established for one of the sibships, belonging to a pedigree in which malignant disease occurred in two generations. The observations indicate that the type of histiocytosis investigated is caused by homozygosity for a single recessive gene. The association between histiocytosis and malignancy is discussed.     

Arterial and venous measurement in resting forearm of metabolic indicators during rest and leg exercise

We compared the levels of various metabolic indicators in arterial and venous forearm blood during maximal treadmill leg exercise, and the subsequent 9 min in nine volunteers aged 31-56 years. At maximal exercise plasma lactate was 13.2 +/- 3.1 mmol l-1 arterially, while venous was 41% lower, but increased more than arterial after exercise. There was a linear relationship between arterial and venous samples during and after exercise, but not at baseline. Plasma pyruvate increased on the arterial side from 49 +/- 8 to 172 +/- 30 mumol l-1 at maximal exercise, maximal venous was 21% lower. Free fatty acids were not different at rest, but decreased during exercise by 52 and 38% on the arterial and venous side. There was no relationship between arterial and venous levels. Changes in these three variables occurred significantly earlier on the arterial side. Arterial cyclic AMP rose from 97.3 +/- 28.4 to 262.7 +/- 67.5 nmol l-1 from rest to exercise, and was linearly inversely related to the decrease in free fatty acids. The mean venous pH was lower than arterial at rest, but was the same as arterial at maximal exercise and after. Thus, venous plasma lactate and pyruvate, but not free fatty acids, are linearly related to arterial measurements during maximal exercise, while pH is identical. Non-working muscle modifies exercise-induced changes, and therefore venous and arterial forearm blood sampling give more information than either alone.     

Spatial learning and memory following fimbria-fornix transection and grafting of fetal septal neurons to the hippocampus

Summary The ability of intrahippocampal grafts of fetal septal-diagonal band tissue, rich in developing cholinergic neurons, to ameliorate cognitive impairments induced by bilateral fimbria-fornix transections in rats was examined in three experiments using the Morris water-maze to test different aspects of spatial memory. Experiment 1. Rats with fimbria-fornix lesions received either septal cell suspension grafts or solid septal grafts; normal rats and rats with lesions alone were used as controls. Sixteen weeks after surgery, the rats' spatial learning and memory were tested in the water-maze using a place test, designed to investigate place navigation performance, in which rats learned to escape from the water by swimming to a platform hidden beneath the water's surface. After 5 days of training, the rats were given a spatial probe test in which the platform was removed from the tank to test spatial reference memory. Experiment 2. The same rats used in Exp. 1 were tested in a delayed-match-to-sample, working memory version of the water-maze task. The platform was located in one of two possible locations during each trial, which was composed of 2 swims. If the rat remembered the location of the platform on the 2nd swim of a trial, it should find the platform more quickly on that swim, and thereby demonstrate working memory. Experiment 3. Prior to receiving fimbria-fornix lesions, normal rats were trained in a modification of the water-maze task using alternating cue navigation and place navigation trials (i.e., with visible or non-visible escape platforms). The retention and reacquisition of the place task and the spatial probe test were examined in repeated tests up to 6 months after the lesion and intrahippocampal grafting of septal cell suspensions. The effects of central muscarinic cholinergic receptor blockade with atropine were also tested. Normal rats performed well in both the place and spatial probe tests. In contrast, rats with fimbria-fornix lesions only were unable to acquire or retain spatial information in any test. Instead, these rats adopted a random, nonspatial search strategy, whereby their latencies to find the platform decreased in the place navigation tasks. Sixty to 80% of the rats with septal suspension or solid grafts had recovered place navigation, i.e., the ability to locate the platform site in the tank, in Exp. 1 and 3, and they showed a significantly improved performance in the working memory test in Exp. 2. Atropine abolished the recovered place navigation in the grafted rats, whereas normal rats were impaired to a lesser extent. In contrast, atropine had no effect on the non-spatial strategy adopted by rats with fimbria-fornix lesions only. The results show that: (1) fimbria-fornix lesions disrupt spatial learning and memory in both naive and pretrained rats; (2) with extended training the fimbria-fornix lesioned rats develop an efficient non-spatial strategy, which enables them to reduce their escape latency to levels close to those of intact controls; (3) intrahippocampal septal grafts can restore the ability of the lesioned rats to use spatial cues in the localization of the platform site; and (4) the behavioural recovery produced by grafts is dependent upon an atropine sensitive mechanism.