Changes in the frequency of benign focal spikes accompany changes in central information processing speed: a prospective 2-year follow-up study.

We prospectively examined whether changes in the frequency of benign focal spikes accompany changes in cognition. Twenty-six children with benign focal spikes (19 with Rolandic epilepsy) and learning difficulties were examined with repeated 24-hour EEG recordings, three cognitive tests on central information processing speed (CIPS), and questionnaires on cognition and behavior at baseline, 6months, and 2years. Antiepileptic drug changes were allowed when estimated necessary by the treating physician. At baseline, a lower CIPS was correlated with a higher frequency of diurnal interictal epileptiform discharges (IEDs) and with worse academic achievement. At follow-up, there was a significant correlation between changes in CIPS and EEG changes in wakefulness (in the same direction) when the EEG outcome was dichotomized in IED frequency "increased" or "not increased". Behavioral problems were more often observed in patients with higher frequency of IEDs in sleep at baseline and in those with ongoing IEDs compared with those with EEG remission (without or with sporadic IEDs in the recording) at the end of the study period. No changes were observed in the results of the questionnaires. A lower diurnal IED frequency at baseline, lack of serial IEDs, and occurrence of only unilateral IEDs were correlated with a higher chance of EEG remission at 2-year follow-up. Electroencephalography remission could not be predicted from other epilepsy variables except from seizure freedom in the last six months. Our results confirm the nonbenign character of 'benign' focal spikes. Whether an early and stable EEG remission can be achieved through antiepileptic treatment and whether this is of benefit for cognitive development should be examined in prospective placebo-controlled randomized trials.

Follow-up of cognitive functioning in patients with small cell lung cancer.

PURPOSE: Study of the course of possible treatment-related cognitive impairment in patients with small cell lung cancer. METHODS AND MATERIALS: Thirty-two consecutive patients with small cell lung cancer underwent successive neurologic and neuropsychologic examinations until 5 months after prophylactic cranial irradiation, and in their pretherapeutic condition were compared to matched controls. Patients with brain metastases were excluded from this study. RESULTS: Neurologic examination revealed central nervous system (CNS) abnormalities only in the 14 patients with brain metastases. In the remaining patients, neuropsychologic tests showed clear differences between the pretherapeutic performance of patients and that of matched controls (p < 0.001), but no significant deterioration either during or after therapy (0.1 < p < 0.8). CONCLUSION: The difference between the pretherapeutic performance of patients and that of matched controls may indicate disease-related cognitive impairment. Within the observation period, no adverse effects of the used therapy were found. Our observations underline the importance of a pretherapeutic assessment in neurotoxicity research.

beta-thromboglobulin in antecubital vein blood--the influence of age, sex and blood group.

Samples of blood for estimation of beta-thromboglobulin (B.T.G.) in normal subjects have been obtained both from blood donors at the end of their donation and from other volunteers by standard venepuncture. The former was a satisfactory method in males only. By standard venepuncture females have on average lower values than males and in the pre-menopausal age groups the difference is statistically significant. Mean values vary little up to 59 years after which they rise slowly but steadily. There is no significant difference in the mean B.T.G. values between the ABO blood groups.

Neuropsychiatric and neuropsychological manifestations of central pontine myelinolysis.

A patient with central pontine myelinolysis (CPM) underwent neurological and mental status examination, as well as neuropsychological testing, during the acute stage of the disease. After correction of the hyponatremia, a gross change in his neuropsychiatric status was observed. The patient underwent extensive neurological, psychiatric, and neuropsychological testing during the acute phase of the disease and at follow-up 4 months later. All major neurological and neuropsychiatric symptoms present at onset were fully reversible. Neuropsychological examination revealed deficits in the domains of attention and concentration, short-term memory and memory consolidation, visual motor and fine motor speeds, and learning ability. Although improved, neuropsychological testing still revealed remarkable deficits at follow-up. We conclude that neuropsychological deficits can accompany CPM, and that these deficits do not necessarily diminish simultaneously with the radiological or clinical neurological findings but may persist for a longer period of time, or even become permanent. In his recovery the patient started to manifest new neurological symptoms consisting of a mild resting tremor of both hands and slow choreoathetotic movements of the trunk and the head, which we considered to be late neurological sequelae of CPM. The significance of CPM in the differential diagnosis of acute behavioral changes after correction of hyponatremia is stressed, even if correction is achieved slowly and carefully.

Can spikes predict seizure frequency? Results of a pilot study in severe childhood epilepsies treated with vagus nerve stimulation.

We evaluated whether spike-rates are useful as an outcome parameter following vagus nerve stimulation (VNS). Spikes/minute and spikebursts/minute were counted in serial electroencephalograms before and after implantation of a vagus nerve stimulator in n = 19 patients with severe childhood epilepsies. In the period of 2 years post VNS, spike-rate and reported seizure frequency were significantly correlated (Spearman's R = 0.61); spikebursts and seizures were correlated with R = 0.74. The response rate, counted after 6 months, was too small to detect differences in responders and non-responders as to spike-reduction. Larger samples and effect sizes are necessary to prove the hypothesis that spike reduction is useful as outcome parameter after VNS or other interventions.

Protection and deprotection of horse cytochrome c.

The last step in the semisynthesis of horse cytochrome c analogues (formation of the bond 65-66) requires the conformation of the complex between two complementary fragments, (1-65) lactone and (66-104). The fragments can be obtained from a limited degradation with cyanogen bromide. The amino component in this reaction can also be obtained from organo chemical synthesis in which the C-terminal fragment (81-104) is required in a selectively protected form. The latter is available from a cyanogen bromide degradation of ubiquitously protected cytochrome c. The details of the protection/deprotection reaction and the properties of nonadecamethylsulfonylethyloxycarbonyl cytochrome c are described.

Semisynthetic horse heart [65-homoserine]cytochrome c from three fragments.

Horse heart cytochrome c was treated with methylsulfonylethyloxycarbonyl succinimide (Msc-ONSu) to give fully N(epsilon)-protected cytochrome c. Treatment of this derivative with a hard base for 15 sec regenerated the native tetrahectapeptide chain. CNBr degradation of the protected compound produced three fragments bearing only protective Msc functions on epsilon-amino groups. The fragment comprising the sequence 81-104 was isolated from the mixture and acylated with N-hydroxysuccinimidyl-t-butyloxycarbonyl-L-methioninate. The resulting pentacosapeptide derivative was partially deprotected by treatment with acid and condensed in good yield (65%) with fully synthetic N(alpha66), N(epsilon72,73,79)- tetra-Msc-cytochrome-c-(66-79)-tetradecapeptide azide. This pathway is preferred because the pentadecapeptide azide derivative 66-80 acylated the N(epsilon)-protected tetracosapeptide sequence 81-104 in an unpredictable manner. Subsequent treatment of the product with a base produced unprotected semisynthetic cytochrome-c-(66-104)-nonatriacontapeptide, which is known to undergo acylation by unprotected [Hse(65)]cytochrome-c-(1-65)-pentahexacontapeptide lactone. The high specificity of this condensation is ascribed to "conformation direction." Semisynthetic [Hse(65)]cytochrome c thus prepared reacts like native cytochrome c with a succinate cytochrome c reductase preparation and with cytochrome c oxidase (ferrocytochrome c:oxygen oxidoreductase, EC 1.9.3.1). This semisynthetic strategy may provide a rapid route for the production of cytochrome c analogs modified in the highly conservative sequence 66-80.

Beta-thromboglobulin in antecubital vein blood in relation to history of a stroke.

The levels of beta-thromboglobulin (BTG) have been measured in the blood of 22 male and 22 female elderly patients who gave a past history of stroke, and in 31 males and 88 females of comparable age who gave no such history. Comparisons were made within and between the groups. In the stroke patients the relationship between BTG and age was not significant for either sex, nor was there a difference between the sexes. In the BTG/time from stroke relationship the females showed significantly higher levels the longer the time that had elapsed since the stroke, and this could not be explained solely by the factor of ageing. For males, on the other hand, there was a non-significant fall in BTG with days from stroke. In 'normal' subjects the BTG/age relationship was significant in females but not in males. No significant differences were demonstrated between the BTG/age relationships between the stroke and control groups and this was true for both sexes. The potential value of estimations of BTG in the elderly is discussed.

Semisynthesis of the native sequence of horse heart cytochrome c-(66-104)-nonatriacontapeptide.

The syntheses of some derivatives of horse cytochrome c-(66-79)-tetradecapeptide are presented. The syntheses are so designed that analogues of this phylogenetically well preserved sequence can be obtained also. The compounds were intended as synthons for the semisynthesis of 65-homoserine-cytochrome c, which we described earlier. A requisite for this project was the C-terminal tetracosapeptide fragment of the protein, accessible through degradation of cytochrome c with cyanogen bromide. The five epsilon amino groups in this compound are reversibly protected with the 2-(methylsulfonyl)ethyloxycarbonyl function, which is resistant to acid and causes little impairment of solubility. The condensation of the fragments leading to the native sequence of horse cytochrome c-(66-104)-nonatriacontapeptide is presented also. The syntheses were performed using the solution strategy. Some unexpected ring closing reactions involving tyrosine and tert.-butyl prolylasparaginylcarbazate, are described.

Neurotoxicity of prophylactic cranial irradiation in patients with small cell carcinoma of the lung.

This study is concerned with effects of prophylactic cranial irradiation on neurological and mental functioning of patients with small cell cancer of the lung. Results are reported of a pilot study in two parts. In a prospective clinical-neurological study, 14 patients with small cell cancer of the lung were evaluated with standard neurological and bedside mental status examinations, before and after irradiation. Their performance was compared with evaluation results of seven small cell cancer of the lung patients who received no irradiation. Dysfunctions were exclusively found in the irradiated patients, which are interpreted as a contributional effect of prophylactic cranial irradiation. Results are reported of further neuropsychological investigation in a sample of five prophylactic cranial irradiation patients. The presence of a rather specific pattern of neuropsychic deficits was confirmed. Areas of malfunctioning were described with some clinical and research implications.

Glutathione conjugation of 4-hydroxy-trans-2,3-nonenal in the rat in vivo, the isolated perfused liver and erythrocytes.

The formation of glutathione (GSH) conjugates of racemic 4-hydroxy-trans-2,3-nonenal (4-HNE) in the rat in vivo in the perfused rat liver and rat erythrocytes has been studied. An HPLC system was developed for the assay of 4-HNE-glutathione conjugates (HNE-SG). The very sensitive electrochemical detection method (detection limit 5 pmol) can also be used to study endogenously formed HNE-SG. Three diastereomeric HNE-SG conjugates could be separated by this system. Rat liver cytosol catalyzed the formation of 2 of the 3 conjugates. When 17 micromol/kg [(3)H] 4-HNE was injected intravenously in the rat, 21% of the radioactivity was excreted within 90 min in bile and 37% in urine. Most of the 4-HNE in bile was present as 2 of the HNE-SG conjugates (molecular mass 463). In addition, 25% was excreted as a third GSH conjugate (molecular mass of 461), which was identified as the lactone of the 4-hydroxynonenoic acid glutathione conjugate. Erythrocytes in vitro eliminated 4-HNE very rapidly, in part by GSH conjugation, suggesting that they may also play an important role in vivo. To study the role of the liver selectively, we used the recirculating perfused rat liver without erythrocytes in the perfusion medium; the same conjugates were found, but the third conjugate was a minor component. These results present direct evidence for the in vivo formation of 4-HNE glutathione conjugates in which the liver may play an important role.

Cytotoxicity and biotransformation of the anticancer drug perillyl alcohol in PC12 cells and in the rat.

The cytotoxic monoterpene perillyl alcohol (POH) has anticancer properties. We investigated its cytotoxicity in PC12 cells in relation to its biotransformation. POH is oxidized by alcohol dehydrogenase and aldehyde dehydrogenase to perillaldehyde (PCO) and perillic acid (PCOOH), respectively. Apoptosis was determined by cell cycle (subG(0)G(1)) analysis and AnnexinV staining followed by flow cytometry. PCO caused apoptosis at 200 microM, POH caused apoptosis from 500 microM on, while PCOOH had no effect. The caspase inhibitor zVAD prevented apoptosis. Inhibition of POH oxidation by 4-methylpyrazol did not prevent the apoptotic effect of POH indicating that POH itself is also apoptotic. To find out to what extent POH is metabolized to PCO, the metabolism of POH, PCO, and PCOOH was determined after intravenous injection in the rat and in isolated hepatocytes. Although PCO can form a glutathione conjugate(s), no indication of the formation of GSH conjugates was found either in vivo or in hepatocytes. About 70% of the dose was recovered as glucuronides in bile and urine. PCOOH generated only the acyl glucuronide, while POH and PCO formed both acyl and ether glucuronides. These results indicate that PCO is a major intermediary metabolite of POH in the rat in vivo and suggest that PCO may contribute to the anticancer effect of POH.

Structural studies of eukaryotic cytochrome c modified at methionine-65.

1H n.m.r. spectra were recorded in both oxidation states for the following species: tuna cytochrome c, tuna [carboxymethylmethionine-65]cytochrome c, horse cytochrome c and horse [homoserine-65]cytochrome c. The experiments give the assignments of the singlet methyl resonances of methionine-65 and the N-terminal acetyl group. The modification at methionine-65 is shown to cause an extremely small structural perturbation to one part of the molecule close to the site of modification.

Structural role of the tyrosine residues of cytochrome c.

The tertiary structures of horse, tuna, Neurospora crassa, horse [Hse65,Leu67]- and horse [Hse65,Leu74]-cytochromes c were studied with high-resolution 1H n.m.r. spectroscopy. The amino acid sequences of these proteins differ at position 46, which is occupied by phenylalanine in the horse proteins but by tyrosine in the remaining two, and at positions 67, 74 and 97, which are all occupied by tyrosine residues in horse and tuna cytochrome c but in the other proteins are substituted by phenylalanine or leucine, though there is only one such substitution per protein. The various aromatic-amino-acid substitutions do not seriously affect the protein structure.