What's inside the art? The influence of frontotemporal dementia in art production.

We evaluated the productions of an artist with frontotemporal lobar degeneration from before dementia onset until she was fully symptomatic. We noted an improvement of technique that might be related to sparing and disinhibition of the right posterior neocortex. There was a reduction of closure (completeness of the painting), possibly induced by impersistence and a decrease in evocative impact that might be explained by frontal and anterotemporal-limbic dysfunction.

Language dominance determined by whole brain functional MRI in patients with brain lesions.

BACKGROUND: Functional MRI (fMRI) is of potential value in determining hemisphere dominance for language in epileptic patients. OBJECTIVE: To develop and validate an fMRI-based method of determining language dominance for patients with a wide range of potentially operable brain lesions in addition to epilepsy. METHODS: Initially, a within-subjects design was used with 19 healthy volunteers (11 strongly right-handed, 8 left-handed) to determine the relative lateralizing usefulness of three different language tasks in fMRI. An automated, hemispheric analysis of laterality was used to analyze whole brain fMRI data sets. To evaluate the clinical usefulness of this method, we compared fMRI-determined laterality with laterality determined by Wada testing or electrocortical stimulation mapping, or both, in 23 consecutive patients undergoing presurgical evaluation of language dominance. RESULTS: Only the verb generation task was reliably lateralizing. fMRI, using the verb generation task and an automated hemispheric analysis method, was concordant with invasive measures in 22 of 23 patients (12 Wada, 11 cortical stimulation). For the single patient who was discordant, in whom a tumor involved one-third of the left hemisphere, fMRI became concordant when the tumor and its reflection in the right hemisphere were excluded from laterality analysis. No significant negative correlation was obtained between lesion size and strength of laterality for the patients with lesions involving the dominant hemisphere. CONCLUSION: This fMRI method shows potential for evaluating language dominance in patients with a variety of brain lesions.

Location of language in the cortex: a comparison between functional MR imaging and electrocortical stimulation.

PURPOSE: To determine the accuracy of functional MR imaging in locating language areas for planning surgical resection. METHODS: Intraoperative photographs were digitized and overlaid on functional MR language maps. The sensitivity and specificity of functional MR imaging for identifying language areas were determined for five different language tasks by comparing functional MR areas of language activation with results of electrocortical stimulation. A match was considered to occur if an activated area contacted overlapped, or surrounded a language tag. The borders of the activation areas were extended by 1 and 2 cm to determine whether the number of matches changed. Language and nonlanguage tag matches were tabulated separately. RESULTS: Sensitivity/specificity for all patients and all language tasks ranged from 81%/53% for areas that touched to 92%/0% for areas separated by 2 cm. Individual language tasks were not as sensitive as a battery of language tasks combined. Location of language areas varied among subjects for a given task and among tasks for a given subject. CONCLUSION: Functional MR imaging should be considered a useful presurgical planning tool for mapping cortical language areas, because it is sensitive, it provides increased time for planning before surgery, and it is noninvasive.

Spontaneous hemoperitoneum in two patients with myeloproliferative disorders.

Spontaneous hemoperitoneum developed in two patients with hitherto undiagnosed myeloproliferative disorders. No other known etiology could be attributed to the two patients described. The report of these two patients suggests that the diagnosis of a myeloproliferative disorder should be considered in the evaluation of patients with spontaneous hemoperitoneum.

Effects of chlorhexidine gluconate in drinking water on dental caries and oral microorganisms in the Syrian hamster.

Hamsters infected with Streptococcus sobrinus (formerly Streptococcus mutans) strain 6715-1119 were given high-sucrose diet 2000. After 5 days, they were presented with 0.05 or 0.1 per cent w/v chlorhexidine gluconate (CHX) continuously in their drinking water, which was well-tolerated. Compared to infected but untreated controls, their caries scores were less by 84 and 97 per cent respectively after 42 days. Coronal dental plaque deposits were reduced in a dose-related fashion. Culture plates of oral swabs showed reductions in Strep. sobrinus and total streptococci after 10 and 35 days of CHX. Hamster oral streptococci were more sensitive to CHX than were lactobacilli but neither was completely eliminated. The incidence of stained tooth deposits after 0.1 per cent CHX was slightly but not significantly greater than in controls.

Reversal of pentamidine-induced hypoglycaemia with oral diazoxide.

Hypoglycaemia is a common and occasionally life-threatening complication of therapy with pentamidine isethionate. We observed inappropriately elevated insulin levels in a patient with Pneumocystis carinii pneumonia and pentamidine-induced hypoglycaemia. Oral diazoxide was effective in reversing the marked hypoglycaemia. Pentamidine may exert its hypoglycaemic effect by stimulating insulin secretion from the pancreas.

Prevalence, distribution of serotypes, and cariogenic potential in hamsters of mutans streptococci from elderly individuals.

The prevalence of mutans streptococci (Streptococcus mutans, Streptococcus cricetus, Streptococcus sobrinus, and Streptococcus rattus) was determined in the salivas of 169 elderly individuals ranging in age from 60 to 87 years. Approximately 40% of these individuals were edentulous and wore full upper and lower dentures. With the exception of a higher proportion of saliva counts below 1,000 CFU/ml in the full-denture wearers, the prevalence and the serotype and species distributions of the mutans streptococci were similar in the denture wearers and individuals with natural teeth only. The species and serotype distributions of mutans streptococci in this elderly population were also consistent with reported observations of other workers on younger, more caries-prone populations. A total of 87 representative isolates of the mutans streptococci were tested for cariogenic potential in a hamster model system. A considerable degree of variation in virulence between different strains was observed. However, these differences were not relatable to individual species or serotypes or to whether the organisms were isolated from denture wearers or naturally dentate subjects. The results of our studies indicate that elderly individuals with either natural or artificial dentitions may be a hitherto unrecognized reservoir of mutans streptococci having varying degrees of potential cariogenicity. Hence, in close family situations they could serve, along with parents and siblings, as vectors in the initial transmission of cariogenic microorganisms to young children.

Cariogenicity of human plaque lactobacilli in gnotobiotic rats.

Thirty-two strains of Lactobacilli, comprising eight species and obtained from human dental plaque or other sources, were tested for cariogenic potential in gnotobiotic Sprague-Dawley rats receiving modified cariogenic Diet 2000. Seventeen of these strains were moderately to highly cariogenic, and only one, a strain of Lactobacillus lactis, was scored as non-cariogenic. The molar fissures were the predominant site of caries attack. Primary lesions of the smooth surfaces were infrequently seen, although these surfaces were often secondarily involved by the extension of fissure lesions. . The preferential location of caries in the sheltered fissure sites was attributed to their inability to form adherent plaque deposits on the smooth surfaces of the teeth. Caries production by a strain of L. salivarius was equally severe on sucrose- or glucose-containing versions of Diet 2000, but glucose was less supportive of caries development than sucrose for a strain of L. fermentum. It is concluded that a wide variety of lactobacilli may be cariogenic under favorable environmental conditions.

Cariogenicity of human oral lactobacilli in hamsters.

Of 50 strains of lactobacilli isolated from dental plaque of school children, two strains, provisionally identified as Lactobacillus salivarius, and one strain, provisionally identified as Lactobacillus fermentum, induced significant caries activity in conventional hamsters. Sucrose was a required dietary cariogenic substrate and could not be replaced with glucose or starch. In contrast to cariogenic strains of Streptococcus mutans the active lactobacilli did not form adherent sucrose-mediated plaques in vitro, did not form intracellular iodophilic polysaccharides and did not form detectable insoluble extracellular polyglucans.