Inhibition of endogenous human dentin MMPs by Gluma.

OBJECTIVE: The objective of this study was to determine if Gluma dentin desensitizer (5.0% glutaraldehyde and 35% HEMA in water) can inhibit the endogenous MMPs of dentin matrices in 60 s and to evaluate its effect on dentin matrix stiffness and dry mass weight. METHODS: Dentin beams of 2 mm×1 mm×6 mm were obtained from extracted human third molars coronal dentin. To measure the influence of Gluma treatment time on total MMP activity of dentin, beams were dipped in 37% phosphoric acid (PA) for 15 s and rinsed in water. The acid-etched beams were then dipped in Gluma for 5, 15, 30 or 60 s, rinsed in water and incubated into SensoLyte generic MMP substrate (AnaSpec, Inc.) for 60 min. Controls were dipped in water for 60 s. Additional beams of 1 mm×1 mm×6 mm were completely demineralized in 37% PA for 18 h, rinsed and used to evaluate changes on the dry weight and modulus of elasticity (E) after 60 s of Gluma treatment followed by incubation in simulated body fluid buffer for 0, 1 or 4 weeks. E was measured by 3-pt flexure. RESULTS: Gluma treatment inhibited total MMP activity of acid-etched dentin by 44, 50, 84, 86% after 5, 15, 30 or 60 s of exposure, respectively. All completely demineralized dentin beams lost stiffness after 1 and 4 weeks, with no significant differences between the control and Gluma-treated dentin. Gluma treatment for 60 s yielded significantly less dry mass loss than the control after 4 weeks. SIGNIFICANCE: The use of Gluma may contribute to the preservation of adhesive interfaces by its cross-linking and inhibitory properties of endogenous dentin MMPs.

Stabilization of dentin matrix after cross-linking treatments, in vitro.

OBJECTIVES: To evaluate the effect of EDC on elastic modulus (E), MMPs activity, hydroxyproline (HYP) release and thermal denaturation temperature of demineralized dentin collagen. METHODS: Dentin beams were obtained from human molars and completely demineralized in 10 wt% H3PO4 for 18 h. The initial E and MMP activity were determined with three-point bending and microcolorimetric assay, respectively. Extra demineralized beams were dehydrated and the initial dry mass (DM) was determined. All the beams were distributed into groups (n=10) and treated for 30 s or 60 s with: water, 0.5 M, 1 M or 2 M EDC or 10% glutaraldehyde (GA). After treatment, the new E and MMP activity were redetermined. The beams submitted to DM measurements were storage for 1 week in artificial saliva, after that the mass loss and HYP release were evaluated. The collagen thermal denaturation temperature (TDT) was determined by DSC analysis. Data for E, MMP activity and HYP release were submitted to Wilcoxon and Kruskal-Wallis or Mann-Whitney tests. Mass loss and TDT data were submitted to ANOVA and Tukey tests at the 5% of significance. RESULTS: EDC was able to significantly increase collagen stiffness in 60s. 10% GA groups obtained the highest E values after both 30 and 60s. All cross-linking agents decreased MMP activity and HYP release and increased TDT temperature. Significant differences were identified among EDC groups after 30 or 60 s of cross-linking, 1M or 2M EDC showed the lowest MMP activity. SIGNIFICANCE: Cross-linking agents are capable of preventing dentin collagen degradation. EDC treatment may be clinically useful to increase resin-dentin stability.

Iodine-131 pharmacokinetics in patients on hemodialysis for end stage renal disease: clinical implications.

AIM: Curative treatment of thyroid cancer is a major issue for patients with end stage renal disease (ESRD) undergoing dialysis because they might not be included in a renal transplant protocol once they have overcome this disease. Since 131I is mostly eliminated by the kidneys, there is concern regarding the toxicity, efficacy and feasibility of 131I-therapy of anuric dialyzed patients. METHODS: This paper reports on 131I uptake and elimination from remnant thyroid tissue (T), salivary glands (SG), stomach (S) and blood, after administration of 3.7 GBq of 131I for 2 patients on twice weekly dialysis for ESRD. RESULTS: Compared to normal renal function patients, radio-iodine recirculation is observed, and SG and blood irradiation is about 6 times higher, but the dose delivered to the thyroid is not significantly enhanced. Dialysis removes more 131I from SG, S and blood than from T. Anticipated dialysis will reduce irradiation by 38% for the blood, 45% for SG and 34% for T. CONCLUSIONS: Therefore, a higher 131I amount could then be used, providing that accurate personalized dosimetry is previously performed using 131I pharmacokinetic models. Concerning radiation protection issues, no significant dialysis equipment contamination is noted, and nurses and medical staff exposure remains below 0.2 mSv.

Immunoradiometric assay of thyroglobulin in patients with differentiated thyroid carcinomas: need for thyroglobulin recovery tests.

As interference from thyroglobulin autoantibodies appears to have been overcome in new commercial thyroglobulin assays by the use of monoclonal antibodies, the need for thyroglobulin recovery tests became uncertain. Sera (n=45) from patients with differentiated thyroid carcinomas were selected on the basis of a thyroglobulin recovery value below 70% in the Dynotest Tg immunoradiometric assay (Brahms) routinely used in our laboratory. Serum thyroglobulin levels were then measured using three other commercial immunoradiometric assays: thyroglobulin ERIA (Pasteur), HTGK (Sorin) and ELSA HTG (Cis Bio International). Thyroglobulin autoantibodies were measured using the Thyrak assay (Brahms). Although many patients were thyroglobulin antibodies-negative (< 200 U/ml, n=26), most immunoradiometric assays failed to detect thyroglobulin in patients with evidence of recurrence. Low thyroglobulin values associated with low thyroglobulin recovery in thyroglobulin antibody-negative patients appear to be more biologically relevant than a single low thyroglobulin value, which can lead to lack of medical intervention. We conclude that the thyroglobulin recovery test is a prerequisite for the correct interpretation of serum thyroglobulin levels determined with immunoradiometric assays in the follow-up of thyroglobulin autoantibody-negative patients treated for differentiated thyroid carcinomas.

First selective amygdalohippocampal radiosurgery for 'mesial temporal lobe epilepsy'.

All the well-documented radiosurgery of epilepsy cases are secondary epilepsies with space-occupying lesions. These results have prompted the idea of testing radiosurgery as a new way of treating epilepsy without space-occupying lesions. We have treated 4 patients with 'mesial temporal lobe epilepsy'. The preoperative evaluation programme was one we usually perform for patients selected for microsurgery of epilepsy. We report the baselines of this treatment, the radiosurgical protocol details, and preliminary results for the first patient treated (follow-up 16 months). Since treatment, the patient has been seizure free, but it is too soon to draw long-term conclusions about the efficiency of the radiosurgery of epilepsy. Morphological (MRI) and functional (PET scan) changes are discussed in relation to our technical choices. Our amygdaloentorhinohippocampal target has been selectively injured.

Effect of drug transit time between exchange locus with plasma and sampling site.

In pharmacokinetic models used to describe the behavior of drugs in living organisms, generally neither the amount of drug flowing in pipes between compartments nor the transfer delay between the plasma-lymph exchange areas and a site of measurement are taken into account. Several former publications dealt with exchanges between two or more different organs assuming that the blood flow was constant or that the variation of the lymphatic flow was negligible or noting that the amount of drug present in pipes was not easily taken into account. In this article, we deal with concentration in a site of interstitial exchanges with regard to concentration in a sampling site with a varying blood flow, assuming that the transit time depends both on the fluid flow and the path length through pipes. In all considered cases, the plasma concentration profile may be highly altered by a change in the flow rate.

Sleep electroencephalogram at the early stage of Creutzfeldt-Jakob disease.

We describe sleep EEG studies in three patients at the early stage of Creutzfeldt-Jakob disease. Little work has been devoted to the study of the sleep EEG in the course of the CJ disease: disorganized sleep architecture was noted, associated with a decrease in stage 4 and an almost complete disappearance of the REM stage. Our patients were considered to have normal stage 2; yet spindles and K complexes were rare at this stage. No evolution towards stage 4 was noted. The percentage of rapid eye movement sleep was significantly low in two cases and normal in one case. Sleep disturbances in the other dementing disorders are reported.

Kufs' disease presenting as progressive dementia with late-onset generalized seizures: a clinicopathological and electrophysiological study.

A 32-year-old woman presented with increasing motor difficulties and memory disturbances. Neurological examination only showed mild cerebellar and extrapyramidal symptoms, whereas neuropsychological evaluation disclosed severe cognitive changes consistent with dementia. Her motor and mental status progressively deteriorated until death, which occurred 5 years after the first admission. One year before death, while she was almost bedridden, symptoms of myoclonic epilepsy first appeared, with frequent generalized seizures and generalized myoclonus, occurring especially upon sensory stimulation or passive joint movements. Pathological examination showed neuronal inclusions typical of Kufs' disease. This case, with primary progressive dementia and late-onset myoclonic epilepsy, differs from previously reported cases. Three special electrophysiological features were abnormal, "giant", evoked potentials; unusually marked photosensitivity; and seizure induction by any sensory stimulation.

[Musical hallucinations]. / Les hallucinations musicales.

Musical hallucinations are rarely reported. Acquired deafness play an important role in their development. The anatomical and neurophysiological substrates for the musical hallucinations are unknown. Most authors related the perceptual disturbance to organic origin (central or peripheral).

[Detection of respiratory allergies using the Phadiatop test in children 1 to 6 years of age]. / Le dépistage de l'allergie respiratoire par le Phadiatop chez l'enfant de un à six ans.

Phadiatop, a new test for detecting hypersensitivity to airborne allergens, was used in 83 children aged 9 months to 6 years with recurrent respiratory manifestations, i.e. recurrent expiratory obstruction and/or recurrent respiratory infections. A good correlation was found between this test and both the prick tests (95%) and the specific IgE assays (91% for RASTS of classes greater than or equal to 1, and 95% for RASTS of classes greater than or equal to 2). However, the correlation was less strong with the total IgE level (68%). The overall correlation with the specialist's prediction based on history and physical evaluation was excellent (94%). In this study, Phadiatop was found to have a 90% sensitivity and a 98% specificity. Furthermore, this test costs 40% less than the often used strategy combining skin tests and determinations of total and specific IgE levels. In the age group studied, Phadiatop is most useful above the age of two, since in younger patients true respiratory allergies are fairly infrequent in recurrent ENT and lower respiratory tract infections, whereas infections are far more common.

[Diagnostic criteria of depressive pseudodementia]. / Critères pour le diagnostic de pseudodémence dépressive.

Ten patients fulfilling the DSM III (A, B, C, D) criteria for both dementia and major depression and presenting the diagnostic dilemma of depressive pseudodementia were included in a prospective study in search of indices for the differential diagnosis of depressive pseudodementia (DPSD) and organic dementia (OD). Patients were assessed with the Hamilton Depression Rating Scale (HDRS), the Blessed Dementia Rating Scale (BDRS), the Wells's criteria, the Mini Mental State (MMS), computerized tomography (CT scan) of the brain, the dexamethasone suppression test (DST), total plasma 3-methoxy-4-hydroxyphenylglycol (MHPG) and sleep electroencephalograms (EEG). Patients suffering from DPSD were defined as showing an improvement higher than 50% in both the HDRS et BDRS scores following adequate antidepressant treatment. Wells's criteria, MMS scores, CT scan and DST do not contribute to the separation of DPSD (n = 6) and OD (n = 4). On the contrary, plasma MHPG levels higher than 35 ng/ml and EEG measures of sleep structure and REM sleep significantly differentiate the two groups.

[Multimodal evoked potentials in human immunodeficiency virus infection]. / Potentiels évoqués multimodaux dans l'infection par le virus de l'immunodéficience humaine.

We have studied 95 HIV seropositive patients (77 males and 18 females; mean age: 31 years): 67 had no neurological symptoms or signs, 28 had various neurological symptoms and signs. This study included a full multimodal evoked potentials (MEP) assessment: visual evoked potentials by flash and reversal checkerboard; brainstem auditory evoked potentials; somatosensory evoked potentials obtained by stimulation of the median nerve. Patient evaluation further included: electroencephalography, electromyography with measurement of conduction velocities and neuroimaging (brain CT scan and/or MRI). We found abnormal MEP for all modalities. The prevalence of abnormal results was high in neurological symptomatic patients; in non neurological ones, the changes tended to be more frequent with the progression of the HIV infection. Whatever the stage of the disease, the various modes were equally affected. MEP were abnormal in 54.7 p. 100 of the cases: in 41.8 p. 100 (28/67) of patient without neurological signs (in 4/12 of fully asymptomatic subjects, 11/34 ARC patients and 13/21 AIDS patients) vs 85.7 p. 100 of neurological symptomatic patients. In neurological asymptomatic patients, a similar proportion of abnormal MEP was found in asymptomatic and ARC patients, while the evolution into AIDS was associated with a higher prevalence of abnormal MEP. In the latter group, MEP changes were nearly as frequent as in neurological symptomatic patients. Comparison between MEP and other electrophysiological procedures (EEG, EMG) and with neuroimaging techniques (CT Scan, MRI) showed the high sensitivity of the MEP technique at all stages of the disease. EMG was a sensitive method and complementary to MEP. The EEG and neuroimaging techniques showed abnormalities principally at the neurological symptomatic stage. Previous studies could not be properly compared.(ABSTRACT TRUNCATED AT 250 WORDS)

Sensory evoked potentials in Creutzfeldt-Jakob disease.

Eight patients presenting with intermediate or terminal evolution of Creutzfeldt-Jakob disease (CJD) were investigated by means of evoked potentials. Fifteen age-matched healthy subjects served as controls. The 8 patients had well-recognizable but simplified flash evoked potentials (FEPs) consisting of P1 and N2 waves followed by a single late positive (P2) deflection. Enlarged FEPs were found in 2 of the 8 patients. The somatosensory central conduction time was normal in 3 of 5 patients, and it resulted in upper normal limits or was moderately slowed in 2 patients. No enlarged somatosensory scalp potentials were recorded. Cortical somatosensory responses were characterized by an unrecognizable (4 patients) or delayed (2 patients) N33 wave. Brainstem auditory evoked responses, recorded in 6 patients, were normal. In CJD very important functional impairment of the sensory cortical areas is associated with absent or mild dysfunction of the subcortical sensory pathways.

[Multimodal evoked potentials in partial epilepsy in children]. / Etude des potentiels évoqués multimodalitaires dans les épilepsies partielles de l'enfant.

A multimodal evoked potential study was realised in three groups of children or adolescents 5 to 15 years old. The first group included 25 normal non-epileptic subjects; the second group was composed of 27 subjects with partial idiopathic epilepsy (PIE) (benign childhood epilepsy with centro-temporal spike; childhood epilepsy with occipital paroxysms); the third group was formed of 20 subjects with partial symptomatic epilepsy (PSE) without patent anatomical lesion or with anatomical lesion. Recording for each subject included: flash visual evoked potentials, pattern visual evoked potentials, brainstem auditory evoked potentials and somatosensory evoked potentials. Each curve obtained was studied for the response morphology, the measure of the different wave latencies, the inter-peak latencies (conduction time) and the amplitudes. A statistical treatment of the data was performed to evaluate the significance of variation of the different parameter values obtained for the various groups. Among the significantly modified parameters, we found: an increase of the amplitudes in the PIE and a decrease in the PSE, specially when an anatomical lesion exists; an asymmetrical amplitude of the somatosensory responses in the PIE with centro-temporal spike; an increase of the central somatosensory conduction time in the PSE with anatomical lesion.

[Somatosensory evoked potentials and action myoclonus]. / Potentiels évoqués somesthésiques et myoclonus d'action.

The authors studied the somatosensory evoked potentials (SEPs) in 16 cases of myoclonic encephalopathies: 8 cases of dyssynergia cerebellaris myoclonica (DCM); 2 cases of dyssynergia cerebellaris progressiva (DCP); 2 cases of Lafora's disease; 1 case of ceroid lipofuscinosis; 3 unclassifiable myoclonic syndromes. The mean age of the patients was 18 years and the mean duration of pre-study evolution was 10 years. All the patients had been treated by anticonvulsant drugs (phenobarbital, valproic acid, benzodiazepines). The amplitude of the complex P1N2 at the level of the contralateral parietal cortex, with stimulation of the median nerve at the wrist, was found to be enlarged in only 6 cases and giant responses (over 40 microV) were obtained in 2 cases. Only half of the patients with DCM presented a high amplitude response. There was no correlation either with clinical parameters (and in particular, certain patients with marked action myoclonic jerks have a normal SEP), or with the EEG data: on the contrary, the amplitude variations of the SEPs are most often similar to variations of the visual evoked potentials.

[Changes in sleep pattern in presenile and senile dementia (author's transl)]. / Altérations du sommeil dans le cours des démences préséniles et séniles.

Analysis of polygraphic recordings of nocturnal sleep in 21 patients with "degenerative" dementia led to the identification of two types of tracing. The first type was characterised by morphologically normal sleep with more marked quantitative changes than those caused by simple aging. In the second type, the criteria of identification of the physiological stages of sleep disappeared, requiring special definition of the E.E.G. appearances seen. These two types corresponded to two different stages of advancement and probably were indicative of the progressive extension of lesions.

Regional femur blood flow measurements with radiolabelled microspheres in fatty liver-induced or corticosteroid treated animals: preliminary report.

Using radio-labelled microspheres, the authors studied bone blood flows in various segments of goose femurs (femoral head, trochanter, condyles). Experiments were conducted on three groups of geese: control, fatty liver induced and corticosteroid-treated animals. The preliminary results suggest that hyperlipemia and fatty liver conditions do not seem to obviously disturb intra osseous blood circulation in fatty geese, although corticosteroids might affect bone blood flows in condyles.