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Healthy aging is characterized by frontal and diffuse brain changes, while certain age-related pathologies such as semantic dementia will be associated with more focal brain lesions, particularly in the temporo-parietal regions. These changes in structural integrity could influence functional brain networks. Here we use multilayer brain network analysis on structural (DWI) and functional (fMRI) data in younger and older healthy individuals and patients with semantic dementia. Relative to younger adults, results revealed lower levels of similarity of connectivity patterns between brain structure and function, and an increased network clustering in frontal regions in healthy older individuals. These changes were either associated with a preservation (similarity) and a decrease (clustering) in cognitive performance. Patients with semantic dementia showed an increase in the similarity of structural and functional connectivity patterns, as well as an increase in clustering in temporo-parietal regions. These changes were respectively associated with a preservation and a decrease in cognitive performance. These results provide a better characterization of distinct profiles of age- and pathology-brain network changes and their association with the preservation or the decline of cognitive functions., Competing Interests: Conflict of interest None., (Copyright © 2024 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

Does it still make clinical sense to talk about semantic dementia? For more than 10 years, some researchers and clinicians have highlighted the need for new diagnostic criteria, arguing for this entity either to be redefined or, more recently, to be divided into two partially distinct entities, each with its own supposed characteristics, namely the semantic variant primary progressive aphasia and the semantic behavioral variant frontotemporal dementia. Why such a shift? Is it no longer appropriate to talk about semantic dementia? Is it really useful to divide the concept of semantic dementia into verbal and socioemotional semantic subcomponents? Does this proposal have any clinical merit or does it solely reflect theoretical considerations? To shed light on these questions, the purpose of the present review was to explore theoretical considerations on the nature of the knowledge that is disturbed in this disease which might justify such terminological changes., Competing Interests: Declaration of competing interest The authors have no disclosure and they have no conflict of interest., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Background: People with neurodegenerative diseases may have difficulty learning new information, owing to their cognitive impairments. Teaching them techniques for learning in social contexts could alleviate this difficulty. The present study will examine the performances of patients with Alzheimer's disease and patients with the semantic variant of primary progressive aphasia on a memory test administered in three social contexts. The protocol will make it possible to identify determinants of social interactions, social abilities, cognition, and personality that can explain the potentially beneficial effect of social context on learning in these patients., Methods: Thirty dyads (patient with primary memory impairment who meets criteria for Alzheimer's disease paired with caregiver), 16 dyads (patient meeting criteria for semantic variant of primary progressive aphasia paired with caregiver), and 46 dyads (healthy controls with no cognitive complaints) will be recruited. A nonverbal memory test (social memory task) will be administered to each dyad in three different social contexts (presence-only, observation, collaboration). Patients and healthy controls will also undergo a neuropsychological assessment to measure social (interactions and abilities), cognitive and personality aspects. Patients will be compared with controls on differential social scores calculated between the presence-only and collaboration contexts, and between the presence-only and observation contexts. A multiple comparative case study will be conducted to identify social, cognitive and personality variables that potentially explain the differential scores in the collaboration and observation contexts., Discussion: For the first time, memory will be assessed in patients with Alzheimer's disease and patients with the semantic variant of primary progressive aphasia in three different contexts (presence-only, observation, collaboration). The multiple comparative case study will make it possible to identify the determinants of memory performance in the social context, in order to create the most beneficial learning context for individual patients, according to their profile., Trial Registration: This study was approved by the Ile de France XI institutional review board (2022-A00198-35), and registered on ClinicalTrials.gov (no. NCT05800028), on April 27, 2023., (© 2024. The Author(s).)

Objective: Semantic tool knowledge underlies the ability to perform activities of daily living. Models of apraxia have emphasized the role of functional knowledge about the action performed with tools (e.g., a hammer and a mallet allow a "hammering" action), and contextual knowledge informing individuals about where to find tools in the social space (e.g., a hammer and a mallet can be found in a workshop). The goal of this study was to test whether contextual or functional knowledge, would be central in the organization of tool knowledge. It was assumed that contextual knowledge would be more salient than functional knowledge for healthy controls and that patients with dementia would show impaired contextual knowledge., Methods: We created an original, open-ended categorization task with ambiguity, in which the same familiar tools could be matched on either contextual or functional criteria., Results: In our findings, healthy controls prioritized a contextual, over a functional criterion. Patients with dementia had normal visual categorization skills (as demonstrated by an original picture categorization task), yet they made less contextual, but more functional associations than healthy controls., Conclusion: The findings support a dissociation between functional knowledge ("what for") on the one hand, and contextual knowledge ("where") on the other hand. While functional knowledge may be distributed across semantic and action-related factors, contextual knowledge may actually be the name of higher-order social norms applied to tool knowledge. These findings may encourage researchers to test both functional and contextual knowledge to diagnose semantic deficits and to use open-ended categorization tests.

Objective: This study aimed to assess the effect of normal aging on the processing of taxonomic and thematic semantic relations., Method: We used the Visual-World-Paradigm coupled with eye-movement recording. We compared performance of healthy younger and older adults on a word-to-picture matching task in which participants had to identify each target among semantically related (taxonomic or thematic) and unrelated distractors., Results: Younger and older participants exhibited similar patterns of gaze fixations in the two semantic conditions. The effect of aging took the form of an overall reduction in sensitivity to semantic competitors, with no difference between the taxonomic and thematic conditions. Moreover, comparison of the proportions of fixations between the younger and older participants indicated that targets were identified equally quickly in both age groups. This was not the case when mouse-click reaction times were analyzed., Conclusions: Findings argue in favor of nonspecific effects of normal aging on semantic processing that similarly affect taxonomic and thematic processing. There are important clinical implications, as pathological aging has been repeatedly shown to selectively affect either taxonomic or thematic relations. Measuring eye-movements in a semantic task is also an interesting approach in the elderly, as these seem to be less impacted by aging than other motor responses.

The aim of the present study was to compare patients with mild to moderate Alzheimer's disease (AD) or semantic dementia (SD) on their cognitive processes and the severity of their daily life activity impairments. Three types of tasks were administered to patients (SD = 15; AD = 31) and 30 healthy controls (HC): 1) informant-based scales and questionnaires, 2) a neuropsychological assessment exploring executive functions, episodic and semantic memory, and 3) a new original test featuring multi-step naturalistic actions and multitasking: the Sequential Daily Life Multitasking (SDLM). We predicted that patients with AD would mainly exhibit task perplexity, associated with episodic and executive deficits on the SDLM, while the behavior of patients with SD would mostly be characterized by object perplexity, associated with semantic memory deficits. Results showed that patients with AD or SD were impaired across all neuropsychological tests, particularly episodic memory in AD and semantic memory in SD. General performance on the SDLM also appeared dramatically impaired in both patient groups, and correlated with results of questionnaires about instrumental activities and memory impairments. However, specific qualitative measurements on the SDLM did not allow us to pinpoint different patterns of errors and behavior in patients with AD versus SD. We suggest that the inability of patients in both groups to perform the SDLM may derive from a constellation of disorders or else from more subtle impairment of cognitive and conative processes that requires further exploration., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

The most recent theories of emotions have postulated that their expression and recognition depend on acquired conceptual knowledge. In other words, the conceptual knowledge derived from prior experiences guide our ability to make sense of such emotions. However, clear evidence is still lacking to contradict more traditional theories, considering emotions as innate, distinct and universal physiological states. In addition, whether valence processing (i.e. recognition of the pleasant/unpleasant character of emotions) also relies on semantic knowledge is yet to be determined. To investigate the contribution of semantic knowledge to facial emotion recognition and valence processing, we conducted a behavioural and neuroimaging study in 20 controls and 16 patients with the semantic variant of primary progressive aphasia, a neurodegenerative disease that is prototypical of semantic memory impairment, and in which an emotion recognition deficit has already been described. We assessed participants' knowledge of emotion concepts and recognition of 10 basic (e.g. anger) or self-conscious (e.g. embarrassment) facial emotional expressions presented both statically (images) and dynamically (videos). All participants also underwent a brain MRI. Group comparisons revealed deficits in both emotion concept knowledge and emotion recognition in patients, independently of type of emotion and presentation. These measures were significantly correlated with each other in patients and with semantic fluency in patients and controls. Neuroimaging analyses showed that both emotion recognition and emotion conceptual knowledge were correlated with reduced grey matter density in similar areas within frontal ventral, temporal, insular and striatal regions, together with white fibre degeneration in tracts connecting frontal regions with each other as well as with temporal regions. We then performed a qualitative analysis of responses made during the facial emotion recognition task, by delineating valence errors (when one emotion was mistaken for another of a different valence), from other errors made during the emotion recognition test. We found that patients made more valence errors. The number of valence errors correlated with emotion conceptual knowledge as well as with reduced grey matter volume in brain regions already retrieved to correlate with this score. Specificity analyses allowed us to conclude that this cognitive relationship and anatomical overlap were not mediated by a general effect of disease severity. Our findings suggest that semantic knowledge guides the recognition of emotions and is also involved in valence processing. Our study supports a constructionist view of emotion recognition and valence processing, and could help to refine current theories on the interweaving of semantic knowledge and emotion processing., (© The Author(s) (2020). Published by Oxford University Press on behalf of the Guarantors of Brain.)

Two studies examined how memories are formed around championship sporting events, which we classify as media events . The first study employed a test-retest methodology to assess how fans of a sport recall a championship sporting event. The second study examined how fans of specific sports teams recalled two championship sporting events in which their team either won or lost. Of particular interest was the emergence of a collective memory within fan communities. We assessed memory for the event itself (event memory), with an emphasis on the emergence of a collective memory, and memory for the context in which one experienced the event (personal circumstance memory). In contrast to fans of a sport more generally, fans of a particular team recalled events involving their team with detail, converged on collective memories, and provided personal circumstance memories that met the criteria for flashbulb memories. We discuss these results in the context of social identities and the elements involved in narratives of media events. Different types of fandom, our measure of social identity, uniquely influenced the collective memories formed for essential and ancillary elements of narratives surrounding championship sporting events.

Objective: The present study explored two types of semantic relationships in semantic dementia (SD), that rely on functionally and neuroanatomically distinct semantic systems (taxonomic vs. thematic)., Method: We used the visual world paradigm coupled with eye-movement recordings, to gain an implicit, fine-grained and dynamic measure of semantic processing. Nine patients with SD and 15 healthy controls performed a simple word-to-picture matching task in which they had to identify each target among semantically related (taxonomic or thematic) competitors and unrelated distractors., Results: We demonstrated different patterns of gaze fixations between patients with SD and controls: while patients with SD and controls were similarly sensitive to competition from taxonomically related pictures, patients with SD were far more sensitive than controls to thematically related competitors before identifying the targets. Moreover, most of the confusion errors made by patients with SD involved taxonomic distractors rather than thematic ones., Conclusions: We interpreted these findings as reflecting a semantic disequilibrium in SD, with increasing overreliance on thematic knowledge as taxonomic knowledge gradually deteriorates. We concluded that thematic relationships constitute a set of residual semantic knowledge and that their exaggerated activation in SD might certainly deserve further explorations to determine their specific role in this disease and notably, their influence on patients' abilities to deal with daily living activities. (PsycINFO Database Record (c) 2020 APA, all rights reserved).

Introduction : Disequilibrium between the taxonomic and thematic semantic systems was previously hypothesized in participants with semantic dementia (SD), without rigorously assessing their ability to identify the two types of semantic relationships. Therefore, the aim of the present study was to directly compare the ability of 10 participants with SD, 10 participants with Alzheimer's disease (AD), and 20 controls to identify thematic versus taxonomic relationships. Methods : Participants performed an explicit forced-choice picture-matching task in which they had to determine which of two pictures of choice was semantically related to the target picture. Target pictures could display natural or artifact objects. Each target was presented once with a taxonomically related picture and once with a thematically related picture. Results : Analyses of correct thematic and taxonomic matches as a function of target domain showed that the performance of the two groups of patients differed in the taxonomic conditions but not in the thematic conditions, demonstrating a relative preservation of thematic knowledge in SD. Additional correlation analyses further indicated that the particular status of thematic relationships in SD was even stronger for artifact concepts. Conclusions : Results provide evidence of the heterogeneous nature of semantic knowledge disruption in SD, and could be regarded as being consistent with the existence of two neuroanatomically and functionally distinct semantic systems. Results further stress the relevance of performing a more detailed and complete assessment of semantic performance in participants with SD, in order to capture the impaired but also preserved aspects of their knowledge.

The jury is a defining component of the American criminal justice system, and the courts largely assume that the collaborative nature of jury deliberations will enhance jurors' memory for important trial information. However, research suggests that this kind of collaboration, although sometimes improving memory, can also lead to incomplete and inaccurate "collective" memories. The present research examines whether jury deliberations, where individuals collaboratively recall and discuss trial evidence to render unanimous verdicts, might shape jurors' memories through the robust phenomena of Within-Individual and Socially Shared Retrieval-Induced Forgetting (WI-RIF and SS-RIF, respectively). The results revealed no WI-RIF or SS-RIF. However, we did find evidence in the direction of Within-Individual and Socially-shared Retrieval Induced Facilitation (WI-RIFA and SS-RIFA, respectively) in speakers' and listeners' narrative and open-ended recall of evidentiary details. The present results are discussed in terms of whether jurors' goals during deliberation and the deliberation structure (e.g., six or more discussants) protect against forgetting, or whether possible methodological issues (e.g., the vast amount of information presented) eliminated WI-RIF and SS-RIF and, in turn, make drawing conclusions surrounding the mnemonic impact of jury deliberation difficult. Regardless, the present results suggest jury deliberations are quite limited in terms of how much evidence is actually discussed compared to the total of what could be discussed, and our methodology provides an ecologically valid baseline for future research to better understand the mnemonic consequences associated with jury deliberations and, in turn, jury decision making., (© 2019 Cognitive Science Society, Inc.)

Objective: Although tool use disorders are frequent in neurodegenerative diseases, the question of which cognitive mechanisms are at stake is still under debate. Memory-based hypotheses (i.e., the semantic knowledge hypothesis and the manipulation knowledge hypothesis) posit that tool use relies solely on stored information about either tools or gestures whereas a reasoning-based hypothesis (i.e., the technical-semantic hypothesis) suggests that loss of semantic knowledge can be partially compensated by technical reasoning about the physical properties of tools and objects., Method: These three hypotheses were tested by comparing performance of 30 healthy controls, 30 patients with Alzheimer's disease and 13 patients with semantic dementia in gesture production tasks (i.e., pantomime of tool use, single tool use, real tool use) and tool or gesture recognition tasks (i.e., functional and contextual matching, recognition of tool manipulation). Individual, item-based patterns of performance were analyzed to answer the following question: Could participants demonstrate the use of tools about which they had lost knowledge? With this aim in mind, "validation" and "rebuttal" frequencies were calculated based on each prediction., Results: Predictions from the technical-semantic hypothesis were more frequently observed than memory-based predictions. A number of patients were able to use and demonstrate the use of tools for which they had lost either semantic or manipulation knowledge (or both)., Conclusions: These data lead to question the role of different types of memory in tool use. The hypothesis of stored, tool-specific knowledge does not predict accurately clinical performances at the individual level. This may lead to explore the influence of either additional memory systems (e.g., personal/impersonal memory) or other modes of reasoning (e.g., theory of mind) on tool use skills., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Research in photobiology is currently limited by a lack of devices capable of delivering precise and tunable irradiation to cells in a high-throughput format. This limits researchers to using expensive commercially available or custom-built light sources which make it difficult to replicate, standardize, optimize, and scale experiments. Here we present an open-source Microplate Photoirradiation System (MPS) developed to enable high-throughput light experiments in standard 96 and 24-well microplates for a variety of applications in photobiology research. This open-source system features 96 independently controlled LEDs (4 LEDs per well in 24-well), Wi-Fi connected control and programmable graphical user interface (GUI) for control and programming, automated calibration GUI, and modular control and LED boards for maximum flexibility. A web-based GUI generates light program files containing irradiation parameters for groups of LEDs. These parameters are then uploaded wirelessly, stored and used on the MPS to run photoirradiation experiments inside any incubator. A rapid and semi-quantitative porphyrin metabolism assay was also developed to validate the system in wild-type fibroblasts. Protoporphyrin IX (PpIX) fluorescence accumulation was induced by incubation with 5-aminolevulinic acid (ALA), a photosensitization method leveraged clinically to destroy malignant cell types in a process termed photodynamic therapy (PDT), and cells were irradiated with 405nm light with varying irradiance, duration and pulsation parameters. Immediately after light treatment with the MPS, subsequent photobleaching was measured in live, adherent cells in both 96-well and a 24-well microplates using a microplate reader. Results demonstrate the utility and reliability of the Microplate Photoirradiation System to irradiate cells with precise irradiance and timing parameters in order to measure PpIx photobleaching kinetics in live adherent cells and perform comparable experiments with both 24 and 96 well microplate formats. The high-throughput capability of the MPS enabled measurement of enough irradiance conditions in a single microplate to fit PpIX fluorescence to a bioexponential decay model of photobleaching, as well as reveal a dependency of photobleaching on duty-cycle-but not frequency-in a pulsed irradiance regimen., Competing Interests: We have the following interests: Chris Merck is affiliated with his own LLC (Merck Engineering LLC). Merck Engineering LLC did not contribute funding to the development of the MPS or its biological validation and has no pecuniary interest in this study. Chris Merck worked as a volunteer collaborator not representing any company or institution. There are no patents, products in development or marketed products to declare. This does not alter our adherence to all the PLOS ONE policies on sharing data and materials.

After demonstrating the relative preservation of fruit and vegetable knowledge in patients with semantic dementia (SD), we sought to identify the neural substrate of this unusual category effect. Nineteen patients with SD performed a semantic sorting task and underwent a morphometric 3T MRI scan. The grey-matter volumes of five regions within the temporal lobe were bilaterally computed, as well as those of two recently described areas (FG1 and FG2) within the posterior fusiform gyrus. In contrast to the other semantic categories we tested, fruit and vegetable scores were only predicted by left FG1 volume. We therefore found a specific relationship between the volume of a subregion within the left posterior fusiform gyrus and performance on fruits and vegetables in SD. We argue that the left FG1 is a convergence zone for the features that might be critical to successfully sort fruits and vegetables. We also discuss evidence for a functional specialization of the fusiform gyrus along two axes (lateral medial and longitudinal), depending on the nature of the concepts and on the level of processing complexity required by the ongoing task., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

Using structural MRI, we investigated the brain substrates of both affective and cognitive theory of mind (ToM) in 19 patients with semantic dementia. We also ran intrinsic connectivity analyses to identify the networks to which the substrates belong and whether they are functionally disturbed in semantic dementia. In line with previous studies, we observed a ToM impairment in patients with semantic dementia even when semantic memory was regressed out. Our results also highlighted different neural bases according to the nature (affective or cognitive) of the representations being inferred. The affective ToM deficit was associated with atrophy in the amygdala, suggesting the involvement of emotion-processing deficits in this impairment. By contrast, cognitive ToM performances were correlated with the volume of medial prefrontal and parietal regions, as well as the right frontal operculum. Intrinsic connectivity analyses revealed decreased functional connectivity, mainly between midline cortical regions and temporal regions. They also showed that left medial temporal regions were functionally isolated, a further possible hindrance to normal social cognitive functioning in semantic dementia. Overall, this study addressed for the first time the neuroanatomical substrates of both cognitive and affective ToM disruption in semantic dementia, highlighting disturbed connectivity within the networks that sustain these abilities.

In the field of apraxia, it has been suggested that the ability to use tools and objects in daily life depends not only on semantic knowledge about tool function and context of use but also on technical reasoning about mechanical properties of tools and objects. The aim of the present work was to assess tool use abilities regarding these hypotheses in patients with neurodegenerative diseases and reduced autonomy. Performance of patients with Alzheimer's disease (AD) (n = 31), semantic dementia (SD) (n = 16) and corticobasal syndrome (CBS) (n = 7) was compared to that of healthy control participants (n = 31) in familiar tool use tasks, functional/contextual associations and mechanical problem solving (MPS). A conversion method was applied to data in order to avoid ceiling effects. Tool use disorders were found in all patient groups but the underlying reasons were different. Patients with SD had difficulties in imagining and selecting familiar tools due to the semantic loss but they performed in normal range in MPS tasks. Interestingly, they performed better with only one tool and its corresponding object, which is interpreted as a partial compensation of semantic loss by spared technical reasoning. Patients with CBS exhibited the reverse pattern, that is, MPS deficits without semantic loss. However, additional qualitative research is needed to disentangle the relative contributions of motor and technical reasoning deficits to this pattern. Both of these profiles were found in patients with AD. For all that, these patients did not commit the same errors as stroke patients with left brain-damage documented in previous works. Several hypotheses are proposed to account for the specificity of tool use disorders in neurodegenerative diseases, and recommendations are provided to caregivers., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

Studies using semantic priming paradigms to measure the integrity of the features underlying concepts in semantic dementia (SD) reported differential impairment, in that functional features appeared to be more robust to brain damage than other features, such as perceptual ones. However, these prior studies were single case reports and the inclusion of too many heterogeneous features under the "functional features" heading casts doubts on their apparent preservation. To verify the robustness of functional features compared with perceptual ones, we carried out a group study where we deliberately restricted the exploration of semantic features to two clearly defined types of attribute: visuoperceptual ("visual") versus contextual-functional ("contextual"). We administered an implicit lexical-decision priming task to 8 SD patients and 31 healthy matched controls, at baseline. Four of the patients underwent a follow-up assessment at one year. For controls, we found a significant priming effect in the visual condition, but not in the contextual one, whereas the SD group exhibited the reverse pattern of performances. The follow-up data provided evidence of the robustness of the dissociation between priming performances in the two attribute conditions. The fact that a particular priming effect was observed in the SD patients but not in controls could be regarded as a sign of semantic disequilibrium. Since perceptual features have been shown to be a core determinant of similarity-based/taxonomic relationships, whereas complementary-based/thematic processing relies mainly on contextual relationships, we interpreted our findings in terms of the differential recruitment of one of the two systems of semantic relationships (taxonomic vs. thematic). Moreover, these two distinct and parallel systems have previously been reported to coexist - and compete - in healthy adults. We thus argue that controls automatically drew on similarity-based/taxonomic relationships, leading to a significant priming effect for visual features but not for contextual ones. By contrast, their impaired perceptual features forced the SD patients to resort to the system of thematic relationships., (© 2013 Published by Elsevier Ltd.)

Semantic dementia is a lobar atrophy syndrome, related to a degeneration of anterior temporal regions, and characterized by a very predominant impairment of semantic memory. Whereas the diagnosis is relatively easy to establish in the typical form and if the patient is seen early, the emergence of possible additional cognitive or psycho-behavioural disorders can lead to a misdiagnosis in favour of a frontotemporal dementia syndrome or even probable Alzheimer's disease., (Copyright © 2013 Elsevier Masson SAS. All rights reserved.)

Category-specific deficits have rarely been reported in semantic dementia (SD). To our knowledge, only four previous studies have documented category-specific deficits, and these have focused on the living versus non-living things contrast rather than on more fine-grained semantic categories. This study aimed to determine whether a category-specific effect could be highlighted by a semantic sorting task administered to 35 SD patients once at baseline and again after 2 years and to 10 Alzheimer's disease patients (AD). We found a relative preservation of fruit and vegetables only in SD. This relative preservation of fruit and vegetables could be considered with regard to the importance of color knowledge in their discrimination. Indeed, color knowledge retrieval is known to depend on the left posterior fusiform gyrus which is relatively spared in SD. Finally, according to predictions of semantic memory models, our findings best fitted the Devlin and Gonnerman's computational account., (Copyright © 2013 Elsevier Inc. All rights reserved.)

The phenomenon of sunglint, well known in satellite remote sensing, lacks a fundamental characterization under controlled laboratory conditions. Exploiting an apparatus specifically assembled for the purpose, we examine the signal collected by a photopolarimeter, pointed at a wavy water surface with measurable statistics and illuminated by a laser source. We also analyze the wave slope distributions, retrieved with an imaging system, and correlate them with the time series of glints. More particularly, we investigate the link between the occurrence of glints and that of the slopes from which they originate. In this context, the results obtained by applying the Hilbert-Huang transform technique to the slope time series are compared with those obtained through a traditional Fourier transform. This novel study first identifies the individual atomic glints as Fresnel reflection originating from a single wave facet. It then discusses the periodic character of a sequence of glints generated by a gravity wave state, as opposed to the erratic behavior of glints typical of capillary wave states. In mixed gravity-capillary conditions, it is shown that the glint properties are governed mainly by the capillary regime.

Microquasars are binary star systems with relativistic radio-emitting jets. They are potential sources of cosmic rays and can be used to elucidate the physics of relativistic jets. We report the detection of variable gamma-ray emission above 100 gigaelectron volts from the microquasar LS I 61 + 303. Six orbital cycles were recorded. Several detections occur at a similar orbital phase, which suggests that the emission is periodic. The strongest gamma-ray emission is not observed when the two stars are closest to one another, implying a strong orbital modulation of the emission or absorption processes.

A multiplex PCR based assay was developed for the highly sensitive and specific detection of Coxiella (C.) burnetii in cow's milk. The assay simultaneously amplifies a diagnostic target within the C. burnetii IS1111 sequence and a control target within the bovine CD18 gene. The internal PCR amplification control allows the discrimination of false negative results (single tube reaction failures) from negative results due to true absence of target sequences. In order to maximize the sensitivity of the assay, a sample preparation method including a centrifugation step to concentrate the bacterium was developed. In milk samples artificially contaminated with serial dilutions of C. burnetii, about four particles per ml could reproducibly be detected. The sensitivities of both assays, multiplex PCR and PCR with only a single pair of primers ('simplex' PCR), were observed to be similar.

A longitudinal study of altogether 1462 women aged 38 to 60 years started in Gothenburg, Sweden in 1968-69. Based on information from the population study and from the Swedish Cancer Registry 35 women had a history of malignant disease when initially examined in 1968-69. During a 12-year follow-up period a total of 79 malignant tumours developed in 73 women. A comparison was made between the 1988 Cancer Registry listing and the observations made in the population study. All but one out of 103 cases (99%) were registered in the Cancer Registry and all but one (99%) in the population study. It may be concluded that the accuracy of the population study registration as well as that of the Cancer Registry at that time were very high. This enables us to draw relatively safe conclusions from our own material when testing for risk factors.

Passage of benzylpenicillin across the mammary gland epithelium was studied both after systemic administration of benzylpenicillin in four goats and after intramammary infusion in three goats and two cows. The results after benzylpenicillin administration alone were compared with the results after combined administration of benzylpenicillin and probenecid. The studies on passage of benzylpenicillin through the blood-milk barrier showed, when milk to plasma ultrafiltrate ratios of benzylpenicillin were plotted versus time for each half of the udders, that active transport takes place from blood to milk during steady-state plasma concentrations. Active transport was demonstrated by inhibition with probenecid: (1) The entry of benzylpenicillin into milk was slowed down under the influence of probenecid. The AUC (area under the curve)-values during the first 30 min. were reduced by 66 +/- 9% compared with the AUC-values found without coadministration of probenecid. (2) In the presence of probenecid and during equilibrium between blood and milk concentrations, benzylpenicillin reached concentration ratios in the ultrafiltrates of milk and plasma which corresponded to those expected for diffusion alone. Without probenecid these ultrafiltrate concentration ratios were more than two times higher indicating an active transport of benzylpenicillin from blood to milk. After intramammary infusion of benzylpenicillin, active transport was demonstrated from milk into blood. The absorption rate for benzylpenicillin from the mammary gland was reduced by probenecid, as measured by the ratio of benzylpenicillin to urea absorption half-life, which was increased by 40-50% in the presence of probenecid.

A method for hysteroscopy in cattle, using a rigid tube for passage through the cervical canal, is described. Using this method, passage through the cervical canal is possible independent of the stage of the gynaecological cycles. The hysteroscopic findings of 105 examinations in cows are described and discussed.

This study refers to a longitudinal population study of women in Gothenburg, Sweden. The prevalences of malignant neoplastic disease in two cross-sectional studies in 1968-1969 and in 1980-1981, respectively, and incidence figures for the 12-year period between these cross-sectional studies are presented. The data on malignant neoplasms were based on interview of the participants in the population study, on information from the Cancer Registry of the Swedish National Board of Health and Welfare and from the Swedish National Bureau of Statistics and were confirmed by death certificates, inpatient and outpatient records and reexaminations of tissue specimens from the tumor tissue. The prevalences of malignant neoplastic disease increased with age from 0.3% at the age of 38 to 9.9% in women aged 60. The incidence rates during the 12-year period increased with age from about 2% in women aged 38 at the beginning of the study to be about 10% in women initially aged 60. Breast cancer was found to be the most common single malignant neoplasm followed by cancer of uterus and cancer of the ovaries.

A correlated angiographic, microangiographic and histological study of eight myxofibrosarcomas is presented. Myxofibrosarcoma is a very recently described type of malignant soft tissue tumour characterized by a mucoid and nodular appearance, predominantly arising superficially in the extremities and trunk in elderly people. Microscopically, the lobulated and myxoid tumours in the present series showed a characteristic plexiform network of fine capillary-like vessels and occasional wide, sinusoidal, angulated vessels. On plain radiographs they were all dense and well demarcated. Angiographically the tumours appeared highly vascular, with irregular tumour vessels often arranged in a patchy or nodular fashion. All revealed signs of a rapid circulation. The microscopic and angiographic appearances were correlated, in two cases utilizing microangiography. In the presence of a superficially located tumour with high density on plain radiographs, marked vascularity, patchy or nodular opacities, and signs of rapid circulation on angiogram one should suspect this diagnosis.

A 15-year-old girl was operated for gastric leiomyoblastoma (epithelioid leiomysocarcoma) with metastasis to a regional lymph node. She has subsequently been operated on twice: once for local recurrence and metastases 9 years after her initial operation and once for an intraabdominal lymph node metastasis. Now, 13 years after her first operation for gastric leiomyoblastoma she is free from symptoms and signs of disease. Preoperative angiography was helpful in diagnosing the recurrence and planning the second operation. Our observations speak in favor of surgical treatment of recurrent and metastasizing gastric leiomyoblastoma. This patient was also operated for multiple pulmonary chondro-hamartomas, primarily suspected to be metastases. Coincidence of gastric leiomyoblastoma and pulmonary chondro-hamartoma does not seem to be due to chance alone.

A clinical, angiographic, pathologic-anatomic, and cytologic study of 12 cases of malignant giant cell tumor of soft tissues is presented. Preoperative angiography was performed in five cases, one of which was also studied by microangiography. Aspiration cytologic examination was performed in five cases and electron microscopy in one case. In nine cases the tumors were deeply situated and in three they were subcutaneous. In six cases the tumors were located within the lower extremity, in four cases in the upper extremity and shoulder, in one case retroperitoneally and in one case in the neck. Except for one case, the follow-up period was 1--14 years. Seven of the patients had died from metastasizing tumor disease at the time of follow-up. High vascularity and rapid circulation characterized the tumors at preoperative angiography. Conventional histology, aspiration cytology, and electron microscopy disclosed histiocyte-like cells, fibroblast-like cells, and multinucleated giant cells of both osteoclast-like benign and pleomorphic malignant type, in varying proportions. The histiocyte-like cells and the giant cells exhibited phagocytic activity at these examinations. The finding of phagocytosing pleomorphic malignant cells and giant cells of osteoclast type in aspiration cytologic material strongly favors the diagnosis of malignant giant cell tumor of soft tissues.

The general principles of homeopathic therapy are described together with a number of homeopathic drugs used for the treatment of acute bovine mastitis. Fifty cows with acute mastitis were used in the study. The initial treatment comprised aconitum D 4, phytolacca D 1 and bryonia D 4. In subsequent treatments phytolacca D 1, bryonia D 4 and lachesis D 8 either singly or in combination were used; mercurius solubilis D 4 was also used. Encouraging results, especially in the treatment of cases of E.coli mastitis, were achieved.

A series of 30 myxofibrosarcomas is described. These malignant soft tissue tumours are characterized by a mucoid and nodular appearance, a coarse plexiform capillary pattern, and they are mostly seen subcutaneously (26 out of 30) in the extremities (24 out of 30) and trunk (4 out of 30) elderly people. Histochemical studies, comprising staining with Alcian blue and toluidine blue at different pH's with and without preceding digestion with testicular hyaluronidase and with the Scott technique, indicated the presence of hyaluronic acid but not sulphated glycosaminoglycans as chondroitinsulphates. Myxofibrosarcoma is believed to belong to the general category of fibroblastic and histiocytic malignant soft tissue tumours. The median diameter of the tumours was 7 cm. They were divided into 4 grades according to cellularity, cell atypia and mitotic activity. The grade III and IV tumours showed pronounced atypia, often with the bi- and multinucleated giant tumour cells and occasionally with giant cells of Touton's type, suggesting a relationship to malignant fibroxanthoma. All of the patients were treated surgically and one received also pre- and post-operative irradiation. None of the 2 grade I myxofibrosarcomas recurred, while 2 out of 7 grade II tumours, 6 out of 10 grade III tumours, and 7 out of 11 grade IV tumours recurred once and up to 9 times. Metastasis appeared in 7 out of 30 patients; grade I tumours were not seen in any of these cases. By the time of follow-up after intervals ranging from 1 month up to 27 years, 14 patients had died; 6 of these had died post-operatively or of intercurrent disease. The differential diagnosis between myxofibrosarcoma and other myxoid soft tissue tumours is discussed.

The effect of a 3-day course of nalidixic acid was studied in 82 women, presenting with the dysuria-frequency syndrome and significant bacteriuria, mostly Escherichia coli sensitive to nalidixic acid. 62/76 patients (82%) that could be evaluated about 1 week after initiation of therapy were subjectively cured. Negative urinary cultures were found in 64/76 patients (84%). Two patients (2.4%) developed resistance to nalidixic acid. Bacteriological cure rate was 76% of 71 patients that could be controlled 1 month after the initiation of therapy. Nalidixic acid in the used granulate preparation initiated only mild side-effects.

A longitudinal population study of 1462 women, aged 38-60 years, was carried out in Gothenburg, Sweden, in 1968-69. In univariate analysis anthropometric variables indicating centrally localized adipose tissue (waist circumference, the ratio of waist to hip circumference and the subscapular skinfold) showed significant age-standardized positive associations with the occurrence (prevalence + incidence data) of endometrial carcinoma. Incidence data suggested that measurements of centrally localized adipose tissue might be of predictive value for this malignancy as well as for ovarian carcinoma. In contrast, measurements of generalized obesity (body weight or body mass index) or peripherally localized adipose tissue (triceps skinfold) showed no associations to these malignancies. No relationship was observed between the anthropometric variables studied and breast carcinoma. The association observed between endometrial and ovarian carcinomas with central adipose tissue did, however, not remain in multivariate analysis when generalized obesity was taken into account. Centrally localized adipose tissue is known to be associated with endocrine abberations including irregular ovulation and menstruation, re-emphasizing the importance of endocrine factors for the pathogenesis of endometrial and ovarian carcinomas. No positive association was found between development of the carcinomas and initial measurements of blood glucose, serum lipids or blood pressure, found to be elevated in cross-sectional studies. An increase in these variables therefore probably are parallel phenomena rather than predictors. The women with endometrial or breast carcinomas smoked more than the remaining women. Although the number of end-points observed was limited these results suggest that measurements of adipose tissue distribution might be a valuable addition to the predictors of endometrial and ovarian carcinomas.(ABSTRACT TRUNCATED AT 250 WORDS)

A correlative cytologic and histologic study of 13 myxofibrosarcomas is presented. The myxofibrosarcomas were grouped histologically into four grades (I to IV) according to the degree of cellularity, atypica and prevalence of mitotic figures. Cytologically, the neoplasms exhibited two types of malignant cells: an elongated, spindle-shaped, fibroblast-like cell and a larger, histocyte-like cell, often embedded in myxoid material. Some aspirates contained small capillary-like fragments. The degree of cellular and nuclear polymorphism and the quantitative distribution between the two types of cells in the different grades corresponded to the histologic classification. The differential diagnosis between myxofibrosarcoma and other myxoid soft tissue neoplasms is discussed. Staining the aspirated material with Alcian blue at different pHs helps to distinguish between myxomatous mesenchymal neoplasms containing nonsulphated glucosaminoglycans, such as myxofibrosarcoma, and those containing sulphated ones, such as myxoid chondrosarcoma and chordoma.