Additional booster doses in patients with chronic lymphocytic leukemia induce humoral and cellular immune responses to SARS-CoV-2 similar to natural infection regardless ongoing treatments: A study by ERIC, the European Research Initiative on CLL

Profound immune dysregulation and impaired response to the SARS-CoV-2 vaccine put patients with chronic lymphocytic leukemia (CLL) at risk of severe COVID-19. We compared humoral memory and T-cell responses after booster dose vaccination or breakthrough infection. (Green) Quantitative determination of anti-Spike specific antibodies. Booster doses increased seroconversion rate and antibody titers in all patient categories, ultimately generating humoral responses similar to those observed in the postinfection cohort. In detail, humoral response with overscale median antibody titers arose in >80% of patients in watch and wait, off-therapy in remission, or under treatment with venetoclax single-agent. Anti-CD20 antibodies and active treatment with BTK inhibitors (BTKi) represent limiting factors of humoral response, still memory mounted in ~40% of cases following booster doses or infection. (Blue) Evaluation of SARS-CoV-2-specific T-cell responses. Number of T-cell functional activation markers documented in each patient. The vast majority of patients, including those seronegative, developed T-cell responses, qualitatively similar between treatment groups or between vaccination alone and infection cases. These data highlight the efficacy of booster doses in eliciting T-cell immunity independently of treatment status and support the use of additional vaccination boosters to stimulate humoral immunity in patients on active CLL-directed treatments.

A new understanding of somatic coliphages belonging to the Microviridae family in urban wastewater

Somatic coliphages (SC) and F-specific RNA coliphages (FRNAPH) have been included in regulations or guidelines by several developed countries as a way of monitoring water safety and the microbiological quality of shellfish harvesting waters. SC are highly diverse in their morphology, size and genome. The Microviridae family contains three genera of phages (Alphatrevirus, Gequatrovirus, and Sinsheimervirus), all having a capsid of similar morphology (icosahedral) and size (25-30 nm in diameter) to that of common pathogenic enteric viruses. Three PCR assays specific for each genus of Microviridae were designed to study these phages in raw and treated wastewater (WW) in order to gain knowledge about the diversity and prevalence of Microviridae among SC, as well as their inactivation and removal during WW treatments. Among the four wastewater treatment plants (WWTPs) monitored here, two WWTPs applied disinfection by UV light as tertiary treatment. First, we noticed that Microviridae represented 10 to 30 % of infectious SC in both raw and treated WW. Microviridae appeared to behave in the same way as all SC during these WW treatments. As expected, the highest inactivation, at least 4 log10, was achieved for infectious Microviridae and SC in both WWTPs using UV disinfection. PCR assays showed that the highest removal of Microviridae reached about 4 log10, but the phage removal can vary greatly between WWTPs using similar treatments. This work forms the basis for a broader evaluation of Microviridae as a viral indicator of water treatment efficiency and WW reuse.

Toward better monitoring of human noroviruses and F-specific RNA bacteriophages in aquatic environments using bivalve mollusks and passive samplers: A case study

Monitoring pathogenic enteric viruses in continental and marine water bodies is essential to control the viral contamination of human populations. Human Noroviruses (NoV) are the main enteric viruses present in surface waters and foodstuff. In a context of global change, it is currently a challenge to improve the management of viral pollutions in aquatic environments and thereby limit the contamination of vulnerable water bodies or foodstuffs. The aim of this study is to evaluate the potential of specific accumulation systems for improving the detection of NoV in water bodies, compared to direct water analyses. Passive samplers (Zetapor filters) and three species of bivalve molluscan shellfish (BMS) (Dreissena polymorpha, Mytilus edulis and Crassostreas gigas) were used as accumulation systems to determine their performance in monitoring continental and marine waters for viruses. F-specific RNA bacteriophages (FRNAPH) were also analyzed since they are described as indicators of NoV hazard in many studies. During a one-year study in a specific area frequently affected by fecal pollution, twelve campaigns of exposure of passive samplers and BMS in continental and coastal waters were conducted. Using suitable methods, NoV (genome) and FRNAPH (infectious and genome) were detected in these accumulation systems and in water at the same time points to determine the frequency of detection but also to gain a better understanding of viral pollution in this area. The reliability of FRNAPH as a NoV indicator was also investigated. Our results clearly showed that BMS were significantly better than passive samplers and direct water analyses for monitoring NoV and FRNAPH contamination in water bodies. A dilution of viral pollution between the continental and the coastal area was observed and can be explained by the distance from the source of the pollution. Viral pollution is clearly greater during the winter period, and stakeholders should take this into consideration in their attempts to limit the contamination of food and water. A significant correlation was once again shown between NoV and FRNAPH genomes in BMS, confirming the reliability of FRNAPH as a NoV indicator. Moreover, a strong correlation was observed between NoV genomes and infectious FRNAPH, suggesting recent viral pollution since infectious particles had not been inactivated at sufficient levels in the environment. More generally, this study shows the value of using BMS as an active method for improving knowledge on the behavior of viral contamination in water bodies, the ranking of the contamination sources, and the vulnerability of downstream water bodies.

TGFα and AVP in the mouse suprachiasmatic nucleus: Anatomical relationship and daily profiles

Daily rhythms in behavior and physiology are under control of the suprachiasmatic nucleus (SCN), the main mammalian circadian pacemaker located in the hypothalamus. The SCN communicates with the rest of the brain via various output systems. The aim of the present study was to determine the neuroanatomical and temporal relationship between two output systems, arginine-vasopressin (AVP) and transforming growth factor alpha (TGFalpha), in the mouse SCN. TGFalpha-positive cells were found throughout the SCN, but more abundantly in the core than the shell area, while AVP was predominantly found in the shell. Fluorescent double labeling revealed a total lack of co-expression for the two proteins in SCN cells. The circadian profile, studied by way of optical density in immunostaining at 3 h intervals, showed peak values for AVP shortly after the LD transitions. Immunoreactivity for TGFalpha was highly variable, especially at time points before the LD transitions. In addition, strong lateralization in TGFalpha immunostaining in the SCN was found in some individuals. Daily fluctuations in the paraventricular nucleus were absent for TGFalpha, and only weakly present for AVP. The main conclusion derived from this study is that these two output systems of the biological clock are anatomically separated with different daily profiles in expression.

Detection of pesticide model compounds in ethanolic and aqueous microdroplets by nonlinear Raman spectroscopy

Pesticide model compounds are detected in microdroplets by means of in situ nonlinear Raman spectroscopy. The chloro- and nitro-substituted aromatics are dissolved in ethanol as well as in water. Their vibrational spectroscopic fingerprint, that is, Raman bands characteristic of the functional groups attached to the aromatic system, is determined in bulk medium by linear Raman spectroscopy. As a result of the concept of group vibrations, the chosen compounds can be regarded as representatives for a whole class of pesticides containing these residues. External seeding of stimulated Raman scattering (SRS) is applied for the detection of these group vibrations of the pesticide model compounds. This technique can be utilized for in situ diagnostics and a noninvasive vibrational spectroscopic analysis of the chemical composition of microdroplets with natural or anthropogenic origin.

Contribution of nitric oxide to the apoptotic process in human B cell chronic lymphocytic leukaemia

B cell chronic lymphocytic leukaemia (B-CLL) is characterised by defective apoptosis that cannot be explained solely on the basis of the known chromosomal abnormalities. We and other have now reported that the leukemic cells spontaneously display the inducible isoform of nitric oxide synthase, iNOS. Inhibition of the iNOS pathway leads to increased apoptosis of the tumoral cells in vitro, indicating that the endogenous release of NO contributes to their resistance to the normal apoptotic process. The factors that induce the expression of iNOS in vivo in the leukemic cells are not yet identified. Yet, as interaction of B-CLL leukemic cells with bone marrow stromal cells promotes their survival, the involvement of adhesion molecules and integrins may be suspected. The engagement of CD23 stimulates iNOS activation in the tumoral cells, suggesting that in vivo interaction of CD23 with one of its recognised ligands may contribute to iNOS induction. A role for CD40-CD40 ligand interaction may also be hypothesised. The mechanisms involved in the anti-apoptotic role of NO are not fully understood, but may implicate the inhibition of caspase activity, hence the impairment of the Fas pathway. In addition, the mitochondrial membrane potential disruption appears to be a NO-sensitive step in the apoptosis cascade. The presence of a NOS displaying anti-apoptotic properties has now been recognised in different cell types, including various leukaemia. A better knowledge of the mechanisms governing the ultimate fate of NO, anti- versus pro-apoptotic would allow the development of new therapeutic approaches for the treatment of these diseases.

Expression of a functional inducible nitric oxide synthase in hairy cell leukaemia and ESKOL cell line

The expression of nitric oxide synthase (NOS) isoforms was investigated in the established ESKOL hairy cell line and in leukemic cells of patients with hairy cell leukemia (HCL). By reverse transcription-polymerase chain reaction (RT-PCR), these cells were found to spontaneously express inducible NOS (iNOS)-specific mRNA, but not endothelial constitutive NOS (ecNOS) mRNA. The iNOS protein was detected by immunofluorescence in the cytoplasm of permeabilized leukemic cells and ESKOL cells, using different anti-iNOS monoclonal antibodies. A protein of 135 kDa was identified by Western blotting in ESKOL and HCL lysates, confirming the presence of an iNOS in these cells. Cytosolic homogenates displayed NOS catalytic activity, as measured by the conversion of 14C-labelled L-arginine into 14C L-citrulline and by detection in situ using the DAF-2DA (diaminofluorescein diacetate) NO-sensitive fluorescent probe. Ligation of CD23 (low affinity IgE receptor) was found to increase iNOS expression in ESKOL and conversely to decrease the percentage of cells undergoing apoptosis, as measured by the percentage of cells expressing annexin V. These results indicate that, as in chronic B cell lymphocytic leukemia cells (B-CLL) a functional iNOS is expressed constitutively in hairy cells that contributes to protecting these tumoral cells from apoptosis.

Anti-emetic effect of ondansetron and granisetron after exposure to mixed neutron and gamma irradiation

The anti-emetic efficiency of orally administered ondansetron and granisetron has been tested in macaques exposed to a mixed y and neutron radiation (6 Gy) with a high neutron/gamma-ray ratio. Our experiments reveal that a single delivery of ondansetron (1 or 2 mg kg(-1)) or of granisetron (0.25 mg kg(-1)) 45-90 min before irradiation or 35-45 min after irradiation was not totally effective. Conversely, the delivery of two doses with the same delay prior to and after exposure led to a complete prevention of vomiting and retching. These observations can be explained by the dual mechanism of radiation-induced emesis: an early peripheral mechanism and a later central mechanism. Two deliveries of 5-HT3 receptor antagonists seem to disrupt serotonergic transmission at the brain stem structures and to affect the peripheral release of serotonin from the gut, thus completely preventing radiation-induced vomiting. This study confirms that the 5-HT3-dependent mechanisms that mediate emesis are similar for both neutron and gamma radiation.

Idiopathic palmoplantar hidradenitis. Report of three cases and literature review

Idiopathic palmoplantar hidradenitis is a new entity consisting of plantar or palmoplantar painful erythematous nodules which affect children in good health. The histopathologic study shows a neutrophilic hidradenitis. We report on 3 new cases of idiopathic plantar hidradenitis and review the literature.

Characterization of a constitutive type III nitric oxide synthase in human U937 monocytic cells: stimulation by soluble CD23

The soluble cleavage fragment of the low-affinity immunoglobulin E (IgE) receptor/CD23 (sCD23 25000 MW) and antibodies directed against their receptors on monocytes, CD11b and CD11c, stimulate the production of nitric oxide (NO) by these cells and we have suggested that the enzyme involved could be related to the endothelial constitutive type III nitric oxide synthase (ecNOS). In the present work, we have analysed the characteristic properties of this NOS isoform in the model of the human promonocytic cells U937 By reverse-transcription polymerase chain reaction (RT-PCR), the presence of an mRNA coding for type III NOS was found in U937 cells and the corresponding protein was detected by immunofluorescence in permeabilized cells with a specific anti-ecNOS monoclonal antibody (mAb). Membrane extracts displayed a NOS activity dependent on the presence of calcium and calmodulin in the reaction medium and that was abrogated in the presence of EGTA. Recombinant soluble CD23 (25000 MW) was found to trigger an NO-dependent cGMP accumulation in these cells, which was abrogated by calcium chelators and inhibitors of the calcium/calmodulin complex. Moreover, sCD23 elicited a transient augmentation of intracytoplasmic free calcium concentration [Ca2+]i that was dependent on the presence of calcium in the external buffer and was prevented in the presence of EGTA, indicating that it was due to a calcium influx. In conclusion, human promonocytic cells such as U937 exhibit a functional type III NOS that can be stimulated by calcium-raising agents, such as sCD23.

Computerized electroencephalographic, polysomnographic, transcranial ultrasound and morphopathological research in vertebro-basilar strokes

This paper contains a clinical, classical electroencephalographic and computerized electroencephalographic (by original methods) study of 271 cases with vertebro-basilar strokes, all the cases being verified by transcranial Doppler ultrasound investigations and some of the patients by morphopathological studies. In the first part, the standard EEG modifications in relation with the clinical pictures and with the affected arterial field are presented. In the second part, the aspects of the computerized EEG recordings with the carrying out of the cortical EEG mappings which have brought important contributions in setting down the topography of the infarctions are discussed. The third part presents the results of the polysomnographic recordings of the 70 selected cases with ischaemic vertebro-basilar attacks without disorders of consciousness (32 cases), with attacks accompanied by symptomatic hypersomnias (13 cases), with ischaemic attacks accompanied by insomnia (5 cases) and with ischaemic attacks with disorders of consciousness (20 cases). The opinion of the authors on the possible relations between the disturbances of the vigilance, the perturbations of the polysomnographic organization of sleep-wakefulness cycles (with the realisation of some interesting competitive dysfunctions between the three states of vigilance) and the electrographic anomalies are discussed.

Clinical, polysomnographic and computerized electroencephalographic research in temporal lobe epilepsies

The present study has selected 125 cases with psychomotor attacks (sometimes secondarily generalized). Polysomnographic recordings were carried out for a continuous period of eight hours. All this time, the patients have been observed by video-monitorization on a closed infrared circuit screen. The diagnostic procedure was supported by several computerized EEG mappings (CEM) according to a model achieved by us, transcribing the primary data which were obtained by Hjorth's NSD parameters (activity and ability) from the Siemens-Elema Mingograph to a microcomputer. In many cases, we have employed an interface which had been envisaged by us for analog-digital conversion of amplitudes and frequencies from the Mingograph to the microcomputer. Sleep organization anomalies were found: increase of the percentages of light slow-wave sleep (LSWS) and of REM sleep and reduction of the percentages of deep slow-wave sleep (DSWS). The temporal foci appeared with the greatest frequency and with a clear-cut evidence during LSWS, especially in REM sleep and in the transitional states of SWS to REM sleep and from REM sleep to wakefulness. Our researches supplemented with CEM, demonstrate a peculiar activation of the temporal foci during REM sleep, during the states of LSWS and during the transitional states, showing that many psychomotor attacks appear predominantly during these sleep states and that many cases initially clinically misinterpreted as grand mal seizures are, in fact, focal temporal epilepsies secondarily generalized.

Polysomnographic and computerized electroencephalographic studies in myoclonic petit mal epilepsies

The study included 203 epileptic absences: 1. Simple; (30 cases); 2. Myoclonic petit mal absences (62 cases); 3. Amyotonic-akinetic absences (41 cases); 4. Temporal lobe absences (62 cases); 5. "Hybrid" absences in Lennox-Gastaud disease (13 children). This paper presents only the myoclonic petit mal absences (57 cases). Correlations of the clinical, EEG and polysomnographic data were found by several methods: a. The patients were video-monitored on an infrared closed-circuit TV screen: b. The Hjorth's NSD parameters were computed on a Siemens-Elema Mingograph; c. The EEG graphoelements were morphologically analyzed every second throughout the discharges, by means of an original technique; d. Computerized EEG mappings (CEM) were performed for various periods, also including the sequential ones, second by second, all along the epileptic discharges; e. 8 hours of continuous polysomnographic recordings. The peculiar electroclinical features of the five types of absences have been emphasized. Regarding the myoclonic petit mal absences, the discharges of polyspikes and waves manifested an evident increase in the number and duration within the LSWS stages and during the transition from the wakefulness state to sleep and from the LSWS to the wakefulness, and a transformation in slow polyspikes and waves complexes during the stages III and IV. The CEM were always asymmetrical during sleep and the maximal amplitudes were seen on the anterior and posterior temporal regions. In all the REM stages, the polyspikes and waves disappeared.

Some recent data on chemical protection against ionizing radiation

Once introduced in the organism, the radioprotectors are fastly degraded and that increases their toxicity, shortens their duration of action and renders them inactive after oral delivery. So, it was tried to protect them by their incorporation in vectors. When a cysteamine-liposomal suspension was orally delivered, it showed a radioprotective activity for about 4 hours. By using 35S cysteamine, it was noted that its plasmatic concentration was increased. Freeze-drying of these preparations was a good mean of conservation if the samples were stored at 4 degrees C. A good and sustained activity was also obtained after oral delivery of WR-2721 entrapped in microspheres. Otherwise, it was shown that after interacting with the polar heads of phospholipids, under determined conditions of pH and in fluid phase, aminothiols can penetrate inside the membrane and be entrapped in the internal medium of liposomes and as they penetrate, they can lessen the diffusion of oxygen in the lipidic bilayers.

Electroclinical correlations in temporal lobe epilepsy

2,698 epileptic patients were studied, 2,019 cases (64.3%) presenting temporal lobe epileptic attacks. Besides the routine EEG recordings and the corroboration of the clinical data with the meticulous observations by video monitoring on a closed circuit TV-screen (the patients being observe in a specially arranged room, provided with infra-red cameras), the diagnostic procedure was supported in all cases by several computerized EEG mappings, according to a model achieved by us, transcribing the primary data obtained by Hjorth's NSD parameters from the Siemens-Elema Mingograph to a Romanian M-118 microprocessor. In many cases we utilized an interface--built by us--for analog-digital conversion which allowed the direct introduction and conversion of amplitudes and frequencies from the Mingograph to the micro-computer. These were isolated to analyse the following electroclinical forms: 1. temporal absences: 360 cases (17.8%); 2. psychomotor attacks: 439 cases (21.7%) 3. psychosensory attacks: 77 cases (3.8%); 4. attacks with cognitive symptomatology: 260 cases (12.8%); 5. crises with ideative-affective symptomatology: 76 cases (3.8%); 6. vegetative attacks: 51 cases (2.5%); 7. akinetic attacks: 89 cases (4.4%); 8. focal temporal attacks secondarily generalized: 667 cases (33.0%). In 112 patients with nocturnal attacks, polysomnographic recordings were performed with sequential computerized EEG mappings during the various stages of sleep (concomitantly with the infrared video-TV monitoring).

Polysomnographical researches in patients with temporal lobe epilepsy

One hundred and twelve patients with temporal lobe epilepsy were studied. Continuous polysomnographical recordings were performed for eight hours, the patients being video-monitored all the time. These researches, completed with computerized EEG cortical mappings demonstrated a peculiar activation of the temporal foci during REM phases and during some stages of LSWS.

Spectral analysis of Doppler signal in the prophylaxis of ischemic cerebrovascular accidents in extra- and/or intracranial carotid and vertebral systems

Using continuous-wave spectral analysis of Doppler signal (SADS) and/or pulsed-wave transcranial Doppler ultrasonography (TCD-US) we examined 263 patients with ischemic cerebrovascular diseases (ICVD) symptoms in the carotid and vertebrobasilar (V-B) systems. The degree of stenosis was established by taking into consideration the parameters of the spectrum of frequency (systolic peak velocity--SV; end-diastolic velocity--DV); the ratio between SV of internal carotid artery (ICA) and common carotid artery (CCA); the ratio between DV of ICA and CCA as well as the value of the spectral broadening (SB) index. The diminution of DV in CCA with increased values of Pourcelot's circulatory resistance index (RP) and spectral broadening index (SB) as compared with the controlateral part, but with apparent increase (over 3.5 kHz) of SV in ICA was constantly observed in significant stenoses of extracranial ICA. Our observations have pointed out that when proximal ICA occlusion is being formed slowly and progressively, ECA (whose increased circulatory resistance under normal conditions reflects diminished diastolic velocities) gradually takes over the hemodynamic characteristics of ICA which is expressed by increased DV, approximating DV and ICA. This situation may give rise to erroneous interpretations.

Polysomnographic and computerized waking-sleep research in epileptic petit mal absences

The authors carried out 8 hours of continuous night polysomnographic recordings in 40 selected cases with various forms of absences. In all these patients, the computerized electroencephalographic mappings were performed according to several methods achieved by the authors. The nocturnal electrographic abnormalities, the morphological patterns of the epileptic discharges during different sleep stages and the cortical computerized cartography were comparatively analysed in the five groups of patients: 1) genuine (pure, classical or simple) petit mal (PM) absences: 8 cases; 2) myoclonic PM absences: 10 cases; 3) amyotonic-akinetic PM absences: 6 cases; 4) "false" temporal epileptic absences: 10 cases; 5) "hybrid" (or "bastard") PM absences in 6 cases with Lennox-Gastaut disease.

A radioprotector: cysteamine, inhibits oxygen transport in lipidic membranes

Spin labeling techniques make possible the observation of oxygen diffusion or concentrations in phospholipid membranes. In such a system, cysteamine, depending upon the molecular cysteamine/DPPC ratio and the pH conditions, inhibits oxygen transport, and this result provides an original explanation for cellular hypoxia after cysteamine administration.

Radioprotective activity of ethylcellulose microspheres containing WR 2721, after oral administration

Ethylcellulose microspheres containing WR 2721 were prepared by the emulsion-solvent evaporation technique. No significant loss or degradation of this phosphorothioate was noted during preparation. Oral administration of these microspheres to mice gave an important lowering of WR 2721 toxicity and an enhancement of its radioprotective activity with a D.R.F. of about 1.7-1.8 over 2-3 h. This action is explained by the protection of WR 2721 from acid hydrolysis and degradation in the gastro-intestinal tract. The adsorption of a fraction of WR 2721 onto the surface of microspheres constitutes an inconvenience. This study confirms the interest of such carriers for providing important sustained radioprotection after oral administration.

The binding of the radioprotective agent cysteamine with the phospholipidic membrane headgroup-interface region

The interaction of the aminothiol radioprotector cysteamine (beta-mercaptoethylamine) (CYST) with dipalmitoylphosphatidylcholine (DPPC) artificial membranes has been studied by differential scanning calorimetry (DSC), turbidimetry and spin labeling. This hydrophilic molecule displays a biphasic, concentration-dependent binding to the phospholipidic head groups at neutral pH. In the CYST/DPPC molar ratio 1:160-1:2 (mole/mole) an increasing ordering effect is observed. At high concentrations (over 3:1 ratio), this ordering effect decreases. With the symmetric disulfide dimer cystamine, the biphasic effect is not shown and the membrane rigidity decrease is obtained only at concentration ratio higher than 1:1. The charge repartition of the cysteamine molecule has been shown to be disymmetric, +0.52 e on the NH3 group and +0.19 e on the SH extremity, [38] whereas the cystamine molecule is electrostatically symmetrical. These properties could be related to their membrane effects. With cysteamine, at a low concentration, an electrostatic bridging between the negatively charged phosphate groups of the polar heads induces the increase in membrane stability: the molecules behave like a divalent cation. At high concentrations a displacement of the slightly charged SH extremity by the amine disrupts the bridges and induces the decrease in rigidity: the drug behaves like a monovalent cation. Due to its symmetric charge and its double length, such an effect is not observed with cystamine. This study could bring further information about the interactions between cysteamine and polyelectrolytic structures (ADN for example) and about the radioprotective properties of this drug.

Interaction of vinblastine sulfate with artificial phospholipid membranes. A study by differential scanning calorimetry and spin labeling

The effect of the antimitotic drug vinblastine sulfate has been studied on fully hydrated dipalmitoylphosphatidylcholine (DPPC) liposomes in the temperature range 0 degrees to 60 degrees using differential scanning calorimetry and electron spin resonance spectroscopy with two fatty acid spin labels. In the gel phase, vinblastine interacts essentially with the DPPC polar heads and induces an important disorganization of the phospholipidic bilayer. The co-operativity of the main thermal transition is decreased. In the crystal-liquid phase, the drug penetrates inside the artificial membrane and induces the formation of domains which increased thermal stability. These effects are opposite to those observed with the drug isaxonine which is used to reduce the axonal degenerating effects due to vinblastine.

Oral administration of liposome-entrapped cysteamine and the distribution pattern in blood, liver and spleen

Oral administration of liposome-entrapped cysteamine induces an increase in the concentration of exogenous sulphur compounds in blood (plasma), liver and spleen. Among those sulphur compounds, an important amount of plasma thiols can be related to a protection of cysteamine in the digestive tract. This can account for the radioprotective effect of a liposomal-cysteamine suspension in rodents, and clearly demonstrates the interest of such a preparation in radioprotection.

A study of the mechanism of cerebral hyperexcitability after irradiation

Whole-body irradiation at a lethal dose induced an early and transient perturbation of 3H-Muscimol specific binding in the mouse cerebellum. The density of high affinity binding sites was decreased and was associated with an increased affinity. This effect can explain early radio-induced cerebral hyperexcitability. Previous injection of cysteamine, which protects against cerebral hyperexcitability, also offers a good protection against this effect.

Isaxonine base is a strong perturber of phospholipid bilayer order and fluidity--a differential scanning calorimetry and spin labeling study

The effects of the neurotropic drug isaxonine on fully hydrated dipalmitoyl-phosphatidyl-choline (DPPC) bilayers has been studied in the temperature range 0 degree-60 degrees, using differential scanning calorimetry and electron spin resonance spectroscopy, with two stearic acid spin labels. At low concentration (1% mol/mol), isaxonine is trapped in the polar interface and enhances the phospholipid multibilayers organization in the gel state. In contrast, at high concentration (30% mol/mol), the drug disorganizes the phospholipidic structures and may induce domain formation by phase separation. The strong interactions of isaxonine at the lipid-water interface change the ionization state of the stearic acid spin labels which become totally ionized. Then isaxonine acts as a modifier of the surface pH of the bilayer. The strong membrane effects of isaxonine may explain in part its pharmacological properties in vivo.

[Radioprotective effect of cysteamine entrapped in liposomes orally administered to the mouse]

Cysteamine entrapped in liposomes was orally delivered to Mice and its radioprotective effect observed as a function of the time elapsed between its administration and 60Co gamma irradiation. A protection is manifest up to 3 hrs after administration. This result contrasts with the absence of protection afforded by cysteamine when orally given as an aqueous solution, and with the short lasting activity of its parenteral administration.

Bone and joint changes in lower limb amputees

A clinical and radiological survey of bone and joint changes in 42 lower limb amputees is reported. There was a significant increase in osteoarthrosis in the knee of the unamputated legs compared with the amputated side. The amputated side characteristically showed osteoporosis. Comparing the prevalence of osteoarthrosis in this study with figures in the population, it is more likely that the osteoporosis of the amputated limb had a protective effect on that side than that mechanical factors produced more osteoarthrosis on the contralateral side. Backache occurred in about half the patients, and was severe in 19%. It did not appear to be related to disc degeneration, but scoliosis was observed in 64% of patients.