Impact of thermal effects induced by ultrasound on viability of rat C6 glioma cells

In order to have consistent and repeatable effects of sonodynamic therapy (SDT) on various cancer cells or tissue lesions we should be able to control a delivered ultrasound energy and thermal effects induced. The objective of this study was to investigate viability of rat C6 glioma cells in vitro depending on the intensity of ultrasound in the region of cells and to determine the exposure time inducing temperature rise above 43 °C, which is known to be toxic for cells. For measurements a planar piezoelectric transducer with a diameter of 20 mm and a resonance frequency of 1.06 MHz was used. The transducer generated tone bursts with 94 μs duration, 0.4 duty-cycle and initial intensity ISATA (spatial averaged, temporal averaged) varied from 0.33 W/cm(2) to 8 W/cm(2) (average acoustic power varied from 1 W to 24 W). The rat C6 glioma cells were cultured on a bottom of wells in 12-well plates, incubated for 24h and then exposed to ultrasound with measured acoustic properties, inducing or causing no thermal effects leading to cell death. Cell viability rate was determined by MTT assay (a standard colorimetric assay for assessing cell viability) as the ratio of the optical densities of the group treated by ultrasound to the control group. Structural cellular changes and apoptosis estimation were observed under a microscope. Quantitative analysis of the obtained results allowed to determine the maximal exposure time that does not lead to the thermal effects above 43 °C in the region of cells for each initial intensity of the tone bursts used as well as the threshold intensity causing cell death after 3 min exposure to ultrasound due to thermal effects. The averaged threshold intensity was found to be about 5.7 W/cm(2).

Diverging oxidative damage and heat shock protein 72 responses to endurance training and chronic testosterone propionate treatment in three striated muscle types of adolescent male rats

The aim of the study was to assess the effects of a combination of anabolic-androgenic steroid abuse and endurance training during adolescence on selected aspects of oxidative stress and antioxidant defenses in various striated muscle types. The effects were studied of testosterone propionate (TP) treatment (8 and 80 mg/kg/week, for 6 weeks), given alone or in combination with moderate-intensity endurance training, starting at adolescence, on thiobarbituric acid-reactive substances and heat shock protein 72 (Hsp72) contents, and androgen receptorm(AR) mRNA level in the heart left ventricle, soleus and extensor digitorum longus of male Wistar rats. TP treatment alone markedly elevated thiobarbituric acid-reactive substances only in the left ventricle and soleus; this effect was but marginally enhanced by endurance training. The training alone markedly elevated Hsp72 content in all muscles studied. TP treatment alone dose-dependently upregulated Hsp72, while the lower TP dose slightly curtailed the effect of the training. Low-dose TP treatment alone elevated, whereas high-dose TP treatment alone lowered androgen receptor mRNA level in the soleus and extensor digitorum longus. Endurance training alone elevated AR mRNA in all muscles studied, whereas TP treatment dose-dependently counteracted this effect. Exercise-associated rise in body temperature was significantly less in the TP-treated rats. We came to the conclusion that chronic suprapharmacological TP treatment might exert a protective effect on muscle cell proteins in adolescent sedentary rats, but it markedly enhanced lipid peroxidation. These effects were unlikely to result from an androgen receptor-mediated genomic action of testosterone. Exercise-related heat stress, and not oxidative stress, was mainly responsible for Hsp72 upregulation in striated muscles of chronic TP-treated endurance-trained adolescent male rats.

Metabolic changes in rat brain following intracerebroventricular injections of streptozotocin: a model of sporadic Alzheimer's disease

A decrease in cerebral glucose metabolic uptake is an early and characteristic sign of Alzheimer's disease (AD). Streptozotocin (STZ) is a bacterial toxin which damages insulin-producing cells and insulin receptors. Intracerebroventricular (icv) application of STZ in rats has been found to chronically decrease cerebral glucose uptake and produce other effects that bear a resemblance to several other molecular and pathological features of AD. In the present experiments in vivo (1)H MR Spectroscopy with short echo time (3 ms) was used to non-invasively obtain a neurochemical profile of rat brains, 3 weeks and 2 months after double icv injections of STZ or vehicle. Seventeen metabolites were quantified from 27 microL tissue volume which included hippocampus and a part of cerebral cortex, using the LCModel and unsuppressed water signal as an internal reference. Three weeks after icv STZ several metabolites were significantly decreased, the most prominent changes noted in glycerophosphocholine and phosphocholine (-38 +/- 5%), glutathione (-37 +/- 4%), taurine (-30 +/- 19%), glutamate (-26 +/- 14%), phosphocreatine (-23 +/- 15%) and N-acetylaspartate (-16 +/- 6%). On the contrary, the concentration of N-acetylaspartylglutamate was found significantly increased (+38 +/- 18%). After 2 months some of these changes were even more pronounced. We conclude that in vivo (1)H MRS of rat brain following icv STZ injections provides a new input into a better understanding of the critical dependency of neural function and structure on brain glucose consumption, and may be of relevance in further studies of AD pathomechanism.

Effect of parenteral cladribine on relapse rates in patients with relapsing forms of multiple sclerosis: results of a 2-year, double-blind, placebo-controlled, crossover study

Objective

This randomized, 2-year, double-blind, placebo-controlled, crossover study evaluated cladribine for relapsing forms of multiple sclerosis.

Design

Patients ( n = 84) received seven 5-day courses of subcutaneous cladribine at 5 mg/day (group A) or placebo (group B) in year 1; treatment was reversed in year 2.

Results

Cladribine was well tolerated and associated with a favorable safety profile. Mean Expanded Disability Status Scale scores remained stable. In group A, mean relapse rates were 0.15 in year 1 (cladribine) and 0.42 in year 2. In group B, relapse rates were 0.61 in year 1 and 0.50 in year 2 (cladribine). Patients required fewer steroid courses during cladribine periods. The therapeutic efficacy of cladribine was associated with a sustained reduction in lymphocyte count.

Astrocytic activation in relation to inflammatory markers during clinical exacerbation of relapsing-remitting multiple sclerosis

The study aimed to assay the cerebrospinal fluid (CSF) levels of protein S100B, a biomarker of astrocyte activation in relation to kynurenic acid (KYNA) and nitric oxide (NO) metabolites, nitrate/nitrite (NOx) concentrations in acute relapse multiple sclerosis (MS) patients. Twenty relapsing-remitting MS (RR-MS) patients and 10 controls were enrolled. RR-MS patients were assessed on the expanded disability status scale (EDSS) and underwent lumbar puncture. The CSF KYNA, NOx and S100B levels were significantly higher in RR-MS group compared to controls (p = 0.01, 0.001, 0.04, respectively). There was a significant correlation between CSF S100B and KYNA (p = 0.01) but not NOx (p > 0.05) in RR-MS. CSF KYNA, NOx or S100B concentrations did not correlate with disease characteristics of MS patients. Our study suggests the activation of the kynurenine pathway leading to the increase of neuroprotective KYNA in the CSF of MS patients during acute relapse what contrasts with chronic phases of the disease.

ESR and monolayer study of the localization of coenzyme Q10 in artificial membranes

The data obtained from the ESR experiments show a complex, depth dependent effect of CoQ10 on the lipid molecules mobility in the bilayer. These effects depend both on its concentration and the temperature. CoQ10 disturbs not only the hydrophobic core of the membrane but also the region close to the hydrophilic headgroups of phospholipids. Both these effects could be explained by the fact that the high hydrophobicity of CoQ10 causes the molecules to position itself in the interior of the bilayer, but at the same time its water seeking headgroup is located close to the region of the polar headgrops of membrane lipids. The presence of CoQ10 in the hydrophobic core has further implications on the properties of membrane intrinsic domain. Results of monolayer experiments indicate that CoQ10 may form aggregates when mixed with PC molecules in the lipid hydrocarbon chain-length dependent manner. CoQ10 is not fully miscible with DMPC or DPPC but it is well miscible with the long-chain DSPC molecules. Our suggestion is that CoQ10 when present in long-chain phospholipid bilayer, interacts with saturated fatty acyl-chains and adapt the structure which allows such interactions: either parallel to the saturated acyl chains or "pseudo-ring" conformation resembling sterol structure.

CDP-choline, but not cytidine, protects hippocampal CA1 neurones in the gerbil following transient forebrain ischaemia

The effects of CDP-choline (citicoline), cytidine monophosphate or cytidine on the number of CA1 hippocampal neurones surviving five-minute forebrain ischaemia have been evaluated in gerbils. The substances tested were given in daily doses equivalent on a molar basis to 500 mg/kg CDP-choline, starting immediately after ischaemia. On day five the brains were perfused, postfixed, cut into 10 microm slices and stained with cresyl violet, and the number of neurones in the CA1 sectors was counted manually under a light microscope at magnification x 400. The results indicate a significant degree of protection provided by citicoline, but no protection by cytidine monophosphate or cytidine. The choline moiety of CDP-choline appears to be essential for the neuroprotective properties of the drug.

[The mechanisms of neuronal death and advances in the neural protection in epilepsy]

Epilepsias are chronic central nervous system diseases which manifest by recurrent seizures. They may be classified into channelopathies resulting from mutations of ionic channels or receptors for neurotransmitters, and epilepsias which are secondary to cortical damage and result from the reconstruction of cortical neural networks. Chronic or generalized seizures initiate processes called the "excititoxic cascade" the effector side of which, quite similar to that of the "ischemic cascade", may lead to neuronal death through either apoptosis or necrosis. Therefore, complementing pharmacological treatment of epilepsia with neuroprotective substances such as free radical scavenger or CDP-choline which blocks the activation of phospholipase A2 may be indicated.

Metabolite ratios measured with a short echo time 1H-MRS in the frontal lobe of young healthy subjects: an approach to generate reference 1H-MRS data

Proton magnetic resonance spectroscopy (1H-MRS) performed with a semi-automated Elscint Prestige 2 Tesla tomograph/spectroscope was used to determine the ratios of the most prominent resonances recorded from the 2 x 2 x 2 cm voxels located in the frontal lobe of healthy young males and females. The values of major metabolite ratios (NAA/Cr, Cho/Cr and ml/Cr) were normally distributed and comparable to results reported by other groups using advanced automated equipment. The coefficients of variation were smaller when the composed metabolite ratios (i.e. the ratios of a given resonance signal to the sum of all signals considered) were calculated. The composed metabolite ratios approach may be more sensitive for discrimination between normal and pathologically changed brain.

Hematological effects of intermittent 2-hour infusions of cladribine in multiple sclerosis patients: a comparison of 2 dosage patterns

Cladribine is a lymphocytotoxic purine nucleoside with potential for treatment of autoimmune diseases. However, optimal administration regimens remain to be established. Twenty multiple sclerosis patients enrolled into this study were given 30 intermittent 2-hour cladribine infusions (0.07 mg/kg per infusion) each. Ten patients received cycles of 5 consecutive daily infusions at 5-week intervals (clustered dosage) on an inpatient basis; the other 10 patients received 1 infusion weekly (nonclustered dosage) on an outpatient basis. Red blood cell (RBC), platelet, and total white blood cell (WBC) counts were assessed at 5-week intervals during the treatment and at 13-week intervals during a 26-week follow-up period. Major WBC and lymphocyte subsets were assessed cytometrically at 15-week intervals during the treatment and at 13-week intervals thereafter. The clustered dosage produced a lasting decline in granulocyte count, a delayed decrease in monocyte count, and a transient decrease in RBC count. The nonclustered dosage caused a larger and persistent decline in RBC count, a smaller (P = .051. compared over the study period) decrease in monocyte count, and no change in granulocyte count. Both regimens transiently reduced natural killer and B-cell subsets (by 40%-60% and >80%, respectively) and caused lasting declines in CD4+ T-cell subsets (by >50%). No significant change was found in CD8+ T-cell subsets. These results show similar potency of these regimens with respect to major lymphocyte subsets, while suggesting that the nonclustered dosage is less toxic to myeloid precursors and more toxic to erythroid lineage precursors.

The effects of citicoline and/or MK-801 on survival, neurological and behavioral outcome of mice exposed to transient hyperglycemia and oligemic hypoxia

The effects of citicoline and/or low dose of MK-801 (sufficient to prevent the development of seizures) on survival, neurological and behavioral recovery following transient hyperglycemic-oligemic-hypoxic insult have been evaluated in mice. Neurological recovery was assessed semi-quantitatively on the third and the 10th day after the insult, and behavioral tests evaluating spontaneous locomotor activity, motor coordination and spontaneous alternation performance were performed on day 10. Neither drug given alone did influence survival rate, but the combination of MK-801 and higher citicoline dose decreased mortality on day 10. Behavioral performance was markedly compromised by the insult. Citicoline, but not MK-801, slightly but significantly improved behavioral outcome in all three tests.

CONCLUSION

when brain ischemic insult is complicated with acute hyperglycemia, post-treatment with citicoline combined with MK-801 in low anti-convulsive dose improves survival and neurological recovery, and citicoline but not MK-801 enhances behavioral recovery.

Malignancy of brain tumors evaluated by proton magnetic resonance spectroscopy (1H-MRS) in vitro

Biopsies of 6 malignant gliomas (grade 3 or 4) and 11 low-grade meningiomas were extracted with perchloric acid or methanol/water, and the fully-relaxed 1H-MRS spectra of the extracts containing water-soluble metabolites and a concentration and chemical shift standard were recorded at 11.4 T. The resonance signals assigned to inositol (Ino), glycerophospho- and phosphocholine (GPC + PC), choline (Cho), creatine and phosphocreatine (Cr + PCr), glutamate (Glu), acetate (Ac), alanine (Ala) and lactate (Lac) were integrated, and analyzed by two methods. First, the concentrations of the aforementioned substances in the bioptates were estimated from their resonance signals in the extracts. Second, these signals were normalized to the Cr + PCr resonance signal. The Mann-Whitney U-test was used to verify statistical significance between the data sets obtained for gliomas and meningiomas. When the first method of analysis was used, the only difference was in the Ala concentration, which in meningiomas was on average 4 times higher than in gliomas (P < 0.01). However, when the second method of analysis was applied, gliomas expressed lower normalized resonance signals of Ala and Glu (P < 0.001, ranges not overlapping), Lac (P < 0.005), as well as Ino and GPC + PC (P < 0.05). In proton MR spectra of brain tumor tissue extracts containing water soluble metabolites, the resonance signals normalized to that of total creatine may provide a very good discrimination between malignant gliomas and low-grade meningiomas.

2-deoxyglucose enhances epileptic tolerance evoked by transient incomplete brain ischemia in mice

The aim of the study was to assess the influence of chronic treatment with a non-metabolisable glucose analogue, 2-deoxyglucose (2-DG) at a 150 mg/kg dose on long-term epileptic tolerance (ET) evoked by 30 min bilateral carotid artery clamping (BCCA) in mice. The effects of protein synthesis inhibition with cycloheximide (CHX), given in three daily doses of 2.5 mg/kg starting either 1 day before (peri-insult regimen) or 1 day after the priming insult (post-insult regimen), on ET development was also studied. Seizures were induced 14 days after BCCA with 3.5 mg/kg of bicuculline; this dose (CD97) evokes convulsions in 97% of normal untreated mice. BCCA resulted in decreased mortality, prolonged latency to the onset of generalised convulsions and decreased overall seizure score. CHX given in the post-insult regimen did not influence, while the peri-insult regimen abolished, all signs of BCCA-evoked ET. 2-DG treatment of sham-operated animals resulted in a moderate but significant decrease in mortality rate and a tendency toward a lower seizure score. BCCA combined with 2-DG treatment resulted in a marked decrease in mortality rate, as well as reduction in all indicators of seizure susceptibility. CHX abolished the antiepileptic effects of BCCA alone, as well as BCCA combined with 2-DG, while it did not influence the 2-DG-related decrease in mortality. We conclude that the development of BCCA-induced epileptic tolerance, as well as unmasking antiepileptic effects of 2-DG by BCCA, is dependent on protein synthesis.

Kinetics of a nucleoside release from lactide-caprolactone and lactide-glycolide polymers in vitro

We assessed the rate of release of a model nucleoside (adenosine, 5%, w/w) from nine different lactide-glycolide or lactide-caprolactone polymers. The polymer discs were eluted every second day with an artificial cerebrospinal fluid at the elution rate roughly approximating the brain extracellular fluid formation rate. Adenosine in eluate samples was assayed by HPLC. Three polymers exhibited a relatively constant release of adenosine for over four weeks, resulting in micromolar concentrations of nucleoside in the eluate. This points to the necessity of further development of polymers of this types as intracerebral nucleoside delivery systems for local treatment of brain tumors.

Brain tolerance and preconditioning

In this review article the authors describe a phenomenon of "brain tolerance" which represents transient resistance of brain tissue to a lethal insult established by preconditioning with a mild insult of short duration. Tolerance evoked by brief ischemia resembles transient ischemic attack(s) (TIA) often preceding full-blown ischemic stroke in a clinical setting. A series of recent studies have described another relevant phenomenon termed "chemical preconditioning". Several substances interfering with cellular energy metabolism applied in subtoxic doses may provide protection against lethal insults of a different type. For example, 3-nitropropionic acid (3-NP), antibiotics erythromycin and kanamycin, acetylsalicylic acid, and 2-deoxyglucose have been shown to evoke tolerance. Recently, we have reported that NMDA receptor antagonists and 2-deoxyglucose used at relatively low doses were potent agents to potentiate the protective anticonvulsant effect induced by transient brain mild ischemia. Further studies are expected to prove similar action of these drugs in other experimental models. Based on the accumulated experimental and clinical data the brain tolerance subsequently reinforced by pharmacological intervention might become a successful prophylactic strategy against serious brain insults in patients.

Cladribine with prednisone versus chlorambucil with prednisone as first-line therapy in chronic lymphocytic leukemia: report of a prospective, randomized, multicenter trial

The efficacy and toxicity of cladribine (2-CdA) + prednisone (P) versus chlorambucil (Chl) + P were compared in previously untreated patients with progressive or symptomatic chronic lymphocytic leukemia (CLL) in a randomized, multicenter prospective trial. Eligible patients were assigned to either 2-CdA 0.12 mg/kg per day in 2-hour infusions and P 30 mg/m(2) per day for 5 consecutive days or Chl 12 mg/m(2) per day and P 30 mg/m(2) per day for 7 consecutive days. Three courses were administered at 28-day intervals or longer if myelosuppression developed. The therapy was finished if complete response (CR) was achieved. Of 229 available patients 126 received 2-CdA+P and 103 received Chl+P as a first-line treatment. CR and overall response rates were significantly higher in the patients treated with 2-CdA+P (47% and 87%, respectively) than in the patients treated with Chl+P (12% and 57%, respectively) (P = .001). Progression-free survival was significantly longer in the 2-CdA-treated group (P = .01), but event-free survival was not statistically different. Thirteen percent of patients were refractory to 2-CdA+P and 43% to Chl+P (P = .001). Drug-induced neutropenia was more frequently observed during 2-CdA+P (23%) than Chl+P therapy (11%) (P = .02), but thrombocytopenia occurred with similar frequency in both groups (36% and 27%, respectively). Infections were seen more frequently in the 2-CdA+P-treated group (56%) than in the Chl+P-treated group (40%; P = .02). Death rates have so far been similar in patients treated with 2-CdA (20%) and with Chl (17%). The probability of overall survival calculated from Kaplan-Meier curves at 24 months was also similar for both groups (78% and 82%, respectively). (Blood. 2000;96:2723-2729)

Immune abnormalities in aneurysmal subarachnoid haemorrhage patients: relation to delayed cerebral vasospasm

Peripheral blood CD3+, CD19+, CD4+, CD8+ and CD45RO+ mononuclear cell subsets, T-cell proliferative responses to combinations of coimmobilized OKT3 antibody and an ECM protein (collagen I, collagen IV, fibronectin or elastin), and T-cell adhesion to collagen IV, fibronectin and elastin were studied in patients with aneurysmal subarachnoid haemorrhage. No significant difference was found in the major lymphocyte subsets between subarachnoid haemorrhage patients receiving no dexamethasone for brain oedema treatment and healthy blood donors. Compared with the latter, both the dexamethasone-untreated and -treated subarachnoid haemorrhage patients showed decreased relative proliferative responses of circulating T cells to OKT3 combinations with collagen IV and fibronectin, and an increased PHA-activated T-cell adhesion to elastin. CD45RO+, CD4+ and CD19+ peripheral blood cell subsets, CD4+/CD8+ cell ratio, PHA-activated T-cell adhesion to fibronectin and collagen IV, and OKT3-triggered T-cell costimulatory responses to elastin, collagen IV and fibronectin were significantly higher in subarachnoid haemorrhage patients presenting with delayed cerebral vasospasm (DCV) than in their DCV-free counterparts. The DCV-related differences in circulating lymphocyte subsets showed no apparent relationship to the glucocorticoid treatment, whereas the differences in the other indices were confined to the dexamethasone-untreated subarachnoid haemorrhage patients. The above results suggest that the CD4+/CD8+ ratio and T cell-ECM interactions play a role in the emergence of subarachnoid haemorrhage/DCV and may represent potential targets for subarachnoid haemorrhage therapy.

Kinetics of a nucleoside release from lactide-caprolactone and lactide-glycolide polymers in vitro

We assessed the rate of release of a model nucleoside (adenosine, 5%, w/w) from nine different lactide-glycolide or lactide-caprolactone polymers. The polymer discs were eluted every second day with an artificial cerebrospinal fluid at the elution rate roughly approximating the brain extracellular fluid formation rate. Adenosine in eluate samples was assayed by HPLC. Three polymers exhibited a relatively constant release of adenosine for over four weeks, resulting in micromolar concentrations of nucleoside in the eluate. This points to the necessity of further development of polymers of this types as intracerebral nucleoside delivery systems for local treatment of brain tumors.

Cladribine with or without prednisone in the treatment of previously treated and untreated B-cell chronic lymphocytic leukaemia - updated results of the multicentre study of 378 patients

Between January 1992 and January 1999, we treated 378 B-chronic lymphocytic leukaemia (CLL) patients with cladribine (2-CdA), and 255 of the patients were also treated with prednisone. A total of 194 patients were previously untreated, and 184 had relapsed or refractory disease after previous other therapy. Complete response (CR) was obtained in 111 (29.4%) and partial response (PR) in 138 (36.5%) patients, giving an overall response (OR) rate of 65.9%. CR and OR were achieved more frequently in patients in whom 2-CdA was a first-line treatment (45.4% and 82.5% respectively) than in the pretreated group (12.5% and 48.4% respectively) (P < 0.0001). The median duration of OR for previously untreated patients was 14.7 months and for pretreated patients 13.5 months (P = 0.09). The median survival evaluated from the beginning of 2-CdA treatment was shorter in the pretreated group (16.3 months) than in the untreated group (19.4 months) (P < 0.0001). A total of 117 (63.9%) patients died in the pretreated group and 63 (32.6%) in the untreated group. In pretreated patients, 2-CdA + prednisone (P) and 2-CdA alone resulted in similar OR (51.0% and 45.0% respectively; P = 0.4). In contrast, in untreated patients, 2-CdA + P produced a higher OR (85.4%) than 2-CdA alone (72.1%) (P = 0.04). Infections and fever of unknown origin, observed in 91 (49.4%) pretreated and 74 (38.1%) untreated patients (P = 0.03), were the most frequent toxic effects. Our results indicate that 2-CdA is an effective, relatively well-tolerated drug, especially in previously untreated CLL.

Effect of FMdC on the cell cycle of some leukemia cell lines

BACKGROUND

(E)-2'-deoxy-2'-(fluoromethylene)-cytidine (FMdC), an irreversible inhibitor of ribonucleotide reductase, displays a strong toxicity towards many cell lines derived from human solid tumors, while its activity on leukemia lines is less well-known. The aim of this study was to assess the effect of FMdC on the cell cycle and cell death of human leukemia lines HL-60 and MOLT-4, and murine leukemia L-1210 in vitro. It has been assumed that a prerequisite of FMdC cytotoxicity is intracellular phosphorylation by deoxycytidine kinase (dCK).

METHODS

Cell cultures in the exponential phase of growth were exposed to different concentrations of FMdC (10 nM to 10 microM) for 6 and 24 hours. In a parallel set of experiments 1 mM deoxycytidine was added to prevent phosphorylation of the drug by dCK. The DNA and protein content in the cells, as well as Annexin V/PI binding were assessed by flow cytometry. The cell cycle was analyzed by the MacCycle software.

RESULTS

The cytotoxic effects of FMdC, i.e., G(1)/S block and cell death were observed, associated with pronounced changes in the protein content. These effects were of variable intensity among the cell lines studied (HL-60 being the most susceptible), and in some cases, were not completely reversed by deoxycytidine excess.

CONCLUSIONS

FMdC is a potent cytotoxic/cytostatic agent against human leukemia cell lines in vitro. It also changes the cellular protein content. Unphosphorylated FMdC may slightly influence the cell cycle of some leukemic lines.

Role of short TE 1H-MR spectroscopy in monitoring of post-operation irradiated patients

Post-surgical radiation therapy is a routine procedure in the treatment of primary malignant brain tumors. Along with modest therapeutic effects conventional fractionated radiotherapy, in spite of any modifications, produces damage to non-malignant brain tissues lying within the treatment volume, the extent of which depends on radiation dose. Serial 1H-MRS allows non-invasive investigation of tissue metabolic profiles. In the present study the ratios of resonance signals assigned to the major 1H-MRS-visible metabolites (N-acetylaspartate, choline, creatine, inositol, lactate and lipid methylene group) were evaluated before, during and after post-surgical fractionated radiotherapy in brain regions close to and more distant from the tumor bed, receiving different radiation exposures (60 and < 40 Gy, respectively). The study group consisted of ten patients (aged 28-51). A MRI/MRS system (Elscint 2T Prestige) operating at the field strength of 2 T and the proton resonance frequency of 81.3 MHz has been used and the 1H-MR spectra were acquired using single voxel double-spin-echo PRESS sequence with a short TE. The spectra were post-processed with automatic fitting in the frequency domain. It was found that although the metabolite profiles depend on the dose obtained, but other stress factors (like surgery) seem to contribute to the overall picture of the metabolic status of the brain as well. In studies of early irradiation injuries, an increase of choline related ratios may serve rather as cell proliferation indictors than as cell injury ones, whereas the mI/Cr ratio appears as one of the first indicators of local irradiation injury. In order to establish the prognostic marker for early radiation damage, however, it seems necessary to analyze all visible metabolites as well. None of the metabolites separately may serve as such an indicator due to the complexity of tissue metabolism. Interestingly, MRI reveals no changes during the therapy process, whereas the metabolite ratios are being affected in the course of time, thus supporting the presumption that the 1H-MRS is a valuable method of radiation therapy monitoring.

Serum cholesterol in cerebral malignancies

Reduced blood cholesterol levels were reported in patients with a variety of malignant peripheral tumors. This fact is likely related to increased cholesterol demand by proliferating tumor cells. The question arises whether this 'tumor-associated hypocholesterolemia' occurs also in patients with brain tumors, and--if it does not--whether its absence can be related to the location of the tumors. We have compared fasting serum total cholesterol levels among three groups of patients: 52 patients with gliomas, 56 patients with symptomatic metastatic brain tumors, and 50 patients harboring malignant tumors of peripheral location but showing no clinical signs of brain metastases. Patients in the last group, despite being--on an average--more age-advanced, had lower total serum cholesterol levels than either the patients with gliomas, or the patients with brain metastases. No difference in the cholesterol levels was found between the two latter groups, and a majority of these patients had borderline or elevated cholesterol levels. This apparent absence of 'tumor-associated hypocholesterolemia' in brain tumor patients may be related to either brain tumors' ability to synthesize cholesterol de novo and their reduced dependence on peripheral cholesterol supply, the existence of brain tumor-blood barrier, effect of medications used to counteract brain edema and seizures, or a combination of these factors.

The application of microspheres from the copolymers of lactide and epsilon-caprolactone to the controlled release of steroids

The microspheres made of the copolymers of lactide and epsilon-caprolactone were used for the controlled release of progesterone and beta-estradiol. The copolymers contained 83-94% of l or d,l-lactide. The influence of the microstructure of lactidyl blocks in the copolymer chains on the drug release rate was studied. More uniform release rate was observed in the case of the copolymer derived from d,l-lactide as composed to l-lactide. For the copolymer containing 83-94% of d,l-lactide units the progesterone and beta-estradiol release rate in vitro was found to be practically constant within over 40 days. The in vivo studies performed on rats revealed that the period of constant release rate of beta-estradiol can be prolonged to about 70 days. The microspheres made of the applied poly-(d,l-lactide-co-epsilon-caprolactone) are the convenient system for long time release of steroids.

Changes in oxidative stress in the rat brain during post-cardiac arrest reperfusion, and the effect of treatment with the free radical scavenger idebenone

The study was designed to determine the effect of idebenone, an electron-trapping agent and free radical scavenger capable of crossing the blood-brain barrier, on cardiac arrest-induced oxidative brain stress. Stress indices used were the brain contents of thiobarbituric acid-reactive material (TBAR), conjugated dienes and protein and non-protein thiols. Twenty-four hours after receiving one oral dose of placebo or 100 mg kg(-1) idebenone, the rats were anaesthetized with diethyl ether and either decapitated immediately, or subjected to 7.5 min cardiac arrest induced by compression of the heart vessel bundle. The next groups of rats were sacrificed at the end of the cardiac arrest session, or resuscitated by external chest compression and artificial ventilation with air and sacrificed 15 min, 60 min, 24 h, and 72 h later while re-anesthetized with diethyl ether. Subsequent placebo or idebenone (100 mg kg(-1)) doses were given to the appropriate surviving rats once daily, beginning 8-10 min after the end of cardiac arrest session. Compared to pre-arrest values, TBAR and conjugated dienes' contents increased, respectively, by 339 and 286%, and protein and non-protein thiol contents decreased, respectively, by 69 and 85% within 60 min after the resuscitation in placebo-treated rats. Normalization of all oxidative stress indices in these rats was slow and incomplete even at 72 h. Idebenone treated rats showed no increase in TBAR contents, and a marked attenuation of changes in the other indices. These results show that oral idebenone greatly reduces oxidative brain stress following transient circulatory arrest in the rat. This effect could not be explained by simple stoichiometric scavenging of free radicals. Possible mechanisms of idebenone action are discussed.

Oral coenzyme Q10 administration prevents the development of ischemic brain lesions in a rabbit model of symptomatic vasospasm

Treatment with oral coenzyme Q10 (CoQ10, 10 mg/kg per day for 6 days) was compared with no treatment in a previously described rabbit model of symptomatic cerebral vasospasm [Endo et al. (1988) Stroke 19: 1420-1425]. The treatment was initiated within 1-2 h after injection of autologous blood into the subarachnoid space. In CoQ10-untreated rabbits, moderate to severe neurological deficits developed, and multiple focal ischemic lesions were found in the brain regions with compromised blood supply, i.e., in the regions normally supplied by common carotid arteries which are subject to ligation in this model. CoQ10 treatment prevented the development of both the neurological deficits and histologically detectable brain tissue damage. In both CoQ10-treated and -untreated rabbits, infiltration of mononuclear cells was evident in the brain stem, although this region did not show signs of ischemic damage. The findings indicate that the histological and neurological correlates of brain tissue damage in this rabbit model of symptomatic cerebral vasospasm develop via mechanism(s) involving free radical-mediated oxidation of plasma lipoproteins. Similar mechanisms may play a role in the development of brain damage attributed to cerebral atherosclerosis.

Activity of 2-chlorodeoxyadenosine (Cladribine) in 2-hour intravenous infusion in 94 previously treated patients with low grade non-Hodgkin's lymphoma

The purpose of our study was to determine the efficacy of 2-chlorodeoxyadenosine (2-CdA) administered in 2-hour intravenous infusions in previously treated patients with low grade non-Hodgkin's lymphoma (LGNHL). We treated 94 LGNHL patients with 2-CdA at a dosage of 0.12 mg/kg/24h in 2-hour intravenous infusion for 5 consecutive days. The treatment consisted of from 1 to 7 courses (median 3), repeated usually at monthly intervals. All patients were refractory to or relapsed after standard chemotherapy. Of these 94 patients 78 (83%) had clinical stage IV of the disease. Complete response (CR) was obtained in 12 (12.8%) and partial response (PR) in 36 (38.3%) giving an overall response rate of 51.1%. In 12 (12.8%) grade 4 thrombocytopenia with haemorrhagic diathesis was noted, grade 4 neutropenia was observed in 12 (12.8%) and infections complicated the course of treatment in 38 (40.4%) patients. 2-CdA treatment was the cause of death of 3 patients. The results of our study show that 2-CdA given in 2-hour infusions is an effective agent in advanced, heavily pretreated patients with LGNHL.

Intermittent 2-hour intravenous infusions of 2-chlorodeoxyadenosine in the treatment of 110 patients with refractory or previously untreated B-cell chronic lymphocytic leukemia

The purpose of our study was to determine the effectiveness of 2-CdA in 2-hour intravenous infusions in the treatment of B-CLL. One hundred and ten patients with B-CLL received 1 to 10 courses of 2-CdA (median 2.5) at a dosage of 0.12 mg/kg daily for 5 consecutive days. Eighteen of them were untreated and 92 relapsed or became refractory to previous therapeutic modalities. Complete remission (CR) was achieved in 8 (7.3%) and partial remission (PR) in 35 patients (31.8%) giving an overall response rate of 39.1%. In 3 patients, cross-resistance to fludarabine was noticed. Toxic effects of 2-CdA were more frequently observed in previously treated patients. Hemorrhagic complications due to drug-induced thrombocytopenia were noticed in 25 (22.7%) and severe infections including sepsis in 14 (12.7%) patients.

2-chlorodeoxyadenosine (2-CdA) in 2-hour versus 24-hour intravenous infusion in the treatment of patients with hairy cell leukemia

Forty one patients with hairy cell leukemia (HCL) were treated with 2-chloro-deoxyadenosine (2-CdA) administered in various schedules. Complete remission (CR) was achieved in 31 (76%) patients and partial remission (PR) in 9 (22%). The mean duration of remission (CR + PR) was 25.2 months (range 9-45 months). One patient did not respond to therapy. Twelve out of 16 patients (75%) achieved CR after 5-day intravenous infusions of 2-CdA and 19 out of 25 patients (76%) after 7-day courses. In 19 out of 23 patients (82.6%) CR was achieved after intermittent 2-hour infusions and in 12 out of 18 (66.7%) after continuous 24-hour infusion. The differences were not statistically significant. Side effects of 2-CdA were similar in both groups except for infections, which were less frequently observed in the group treated for 5 days. The results of our study suggest that 2-CdA can be effectively administered to patients with HCL using 5-day courses and a 2-hour daily infusion.

Survival and maturation of heterotopic fetal brain stem xenografts after treatment with 2-chlorodeoxyadenosine and cyclosporine A

Brain stem halves from fetal rabbits were transplanted to the caudate nucleus area of adult rats. The animals were treated postoperatively with cyclosporine A (CsA) and 2-chlorodeoxyadenosine (CdA) for three days, and with CdA alone for the next 13 days. The treatment started at the day of implantation, and in some animals it was repeated starting at day 36 after grafting (at the time when signs of a light inflammatory reaction appeared in some grafts). Grafts survived and matured histologically, and no signs of acute rejection were observed up to the 90th day. In some grafts we recorded phasic neuronal activities similar to the respiratory-related neural activities characteristic for the adult brain stem. Immunosuppressive with CdA and CsA deserves further evaluation in fetal brain grafting.

[Treatment of multiple sclerosis with cladribine (2-CDA), a new immunosuppressant agent. Theoretical basis and preliminary results]

The rationale for immunosuppressive treatment of multiple sclerosis comes from current concepts of pathogenesis of this disease. However, clinical effects of immunosuppression have been largely disappointing. Cladribine (chloro-2'-deoxyadenosine, 2CdA) is a new antileukaemic drug which also shows a strong immunosuppressive activity in vitro and in vivo. Being successfully used to treat lymphoproliferative diseases during last few years, cladribine is currently tested in multiple sclerosis. Preliminary results of two independent randomized, placebo-controlled trials are very promising. The indicate that treatment with cladribine may halt the progression of chronic progressive MS, and decrease the frequency of relapses and improve neurological status in remitting-relapsing stage of the disease.

Depressed immune surveillance against cancer: role of deficient T cell: extracellular matrix interactions

Although T cells infiltrate malignant tumors, the local immune response is usually inefficient and tumors escape destruction. While extracellular matrix proteins strongly costimulate T cell responses in normal individuals, our studies indicate that peripheral blood T cells from cancer patients and tumor infiltrating cells respond poorly or are resistant to stimulative signals mediated by collagen I and IV and fibronectin. Moreover, the adhesive properties of cancer T cells are markedly depressed. Those functional deficiencies are paralleled by variable deficits in integrin and non-integrin T cell receptors for extracellular matrix. Immunotherapy with BCG causes a dramatic but transient increase in T cell: ECM interactions.

Cladribine (2-chloro-deoxyadenosine, CDA): an inhibitor of human B and T cell activation in vitro

We have previously shown that the novel immunosuppressive agent cladribine (CDA) inhibits human T and B cell lymphoproliferative responses and immunoglobulin synthesis in vitro, yet appears to be particularly efficacious as an inhibitor of B cell responses. We now report the effects of CDA on the human mixed lymphocyte reaction and on expression of T and B cell activation markers. CDA produced a significant inhibition of lymphocyte proliferation in human mixed lymphocyte reactions at a concentration of 10 nM. At concentrations of 10-100 nM the drug inhibited phytohaemagglutinin-induced expression of CD25 and HLA-D (by approximately 50%), but not phorbol myristate acetate-induced expression of CD69 on purified human T cells. At a concentration of 10 nM CDA totally abolished Staphylococcus aureus Cowan-induced expression of CD25 on purified B cells. These findings confirm that CDA is a potent immunosuppressive agent with some selectivity towards B cells. The drug may have potentially wide applications in clinical immunosuppression.

Impaired in vitro proliferative response of suppressor lymphocytes in patients with subarachnoid haemorrhage from ruptured intracranial aneurysm

Proliferative response to mitogens concanavalin A, phytohemagglutinin and pokeweed mitogen, and other chosen indicators of the activity of the immune system were assayed in peripheral blood mononuclear cells isolated from blood of patients with subarachnoid haemorrhage from ruptured aneurysm. Healthy blood donors served as control group. The SAH group displayed impaired response to concanavalin A, which is a mitogen specific for suppressor cells. It is suggested that the impaired activity of suppressor cells pre-existed in patients with subarachnoid haemorrhage, and after intracranial bleeding it might have contributed to the development of late neurological deficits.

Successful prevention of neurological deficit in SAH patients with 2-chlorodeoxyadenosine

Twenty patients suffering from subarachnoid haemorrhage due to ruptured intracranial aneurysm and operated on within 72 h after SAH were treated with an experimental immunosuppressive drug 2-chlorodeoxyadenosine (2-CDA), dose 0.05 mg/kg/day i.v. for 7 days. The 2-CDA treatment was started immediately after angiographic confirmation of ruptured aneurysm, and the standard pharmacological treatment (nimodipine and steroids) was also given. 50% of patients were severely threatened by "delayed vasospasm" or late neurological deficit (Fisher's score 3 or 4). The neurological outcome (assessed 8-12 weeks after SAH) was good (GOS = 1) in 70%, and fair (moderate disability, GOS = 2) in 25%. A single case of severe disability (GOS = 3), as well as two cases of less than perfect outcome (GOS = 2), were related to unusual pre- or intraoperative complications. We conclude that the low doses of 2-CDA can be considered as a valuable adjunct to the standard pharmacotherapy of SAH patients operated on early.

2-Chloro-2' deoxyadenosine prevents angiopathic changes in cerebral arteries in experimental SAH in rabbits

We compared the morphology of the basilar artery walls in rabbits with experimental subarachnoid haemorrhage (SAH) without and with concomitant treatment with a novel immunosuppressive drug, 2-chloro-2'-deoxyadenosine (2 CdA). The treatment was successful in the prevention of the angiopathic changes, most likely due to its ability to inhibit lymphocyte activation in response to mitogenic signals. Since lymphocyte (and monocyte?) activation may play an important role in the development of the delayed neurological deficits in patients following SAH, the use of 2 CdA to prevent these deficits shall be considered.

Adsorption therapy with tryptophan-conjugated polyvinyl alcohol gels in 10 patients with acute Guillain-Barré syndrome

In 10 cases of acute Guillain-Barré syndrome selection adsorption (SEA) of immunoglobulins was performed with IM TR350 columns (Asahi Medical, Japan). During this therapy the symptoms of 8 patients were reduced. Side effects were moderate and not specific for SEA. The columns removed large amounts of immunoglobulins, but also eliminated other plasma components.

Plasma exchange and selective adsorption in Guillain-Barré syndrome--a comparison of therapies by clinical course and side effects

Selective adsorption is a new method of treating Guillain-Barré syndrome. Its therapeutic effects and its concomitant side effects were compared between plasma exchange and symptomatic treatment only. The clinical study of three groups of 10 Guillain-Barré patients, each matched for age and maximal disability, was analyzed. Selective adsorption compared favorably with plasma exchange in shortening the time to first improvement and duration of in-hospital treatment. Side effects were similar in both groups. Symptomatic arteriosclerosis should be considered a relative contraindication for selective adsorption.

Antioxidant systems--physiology and pharmacotherapy trends

Metabolic processes connected with the effects of oxidation and antioxidation with participation of cellular energy are presented and therapeutic possibilities connected with coenzyme Q and N-acetylcysteine are discussed.

Evidence for sex steroid receptors in feline brainstem

Specific binding sites for estrogens, androgens, and progestins were found in cytosol from perfused cat brainstem with the use of a steroid binding assay. These sites resemble 'classical' steroid receptors in ligand specificity as well as in sedimentation properties (sedimentation constant 8-10S on sucrose density gradient). The presence of estrogen receptor in brainstem extracts was also confirmed by an enzyme immunoassay employing monoclonal antibodies directed against human estrogen receptor. This finding may be relevant to known influences of sex steroids on respiration.

HLA antigens and intracranial aneurysms

The frequencies of the HLA-A, -B and -DR were determined in a group of 59 transplant donors who died from subarachnoid haemorrhage within three days following the rupture of intracranial aneurysm (the SAH group) and compared with those of a control group consisting of 389 donors who died from other causes. The only significant difference was in the increased frequency in the SAH group of non-typed ("empty")-DR loci in association with the DR7 phenotype. The most probable explanation of this finding is that in the SAH group the frequency of DR7 homozygotes is several times higher than in the general population, and that bearing the DR7 allele in homozygotic form is associated with a very high risk of developing potentially fatal intracranial aneurysmal haemorrhage.