Multi-modality mapping of motor cortex: comparing echoplanar BOLD fMRI and transcranial magnetic stimulation. Short communication

Multiple non-invasive methods of imaging brain function are now available for presurgical planning and neurobiological research. As these new methods become available, it is important to understand their relative advantages and liabilities, as well as how the information gained compares across different methods. A current and future trend in neurobiological studies as well as presurgical planning is to combine information from different imaging techniques. Multi-modal integration may perhaps give more powerful information than each modality alone, especially when one of the methods is transcranial magnetic stimulation (TMS), with its ability to non-invasively activate the brain. As an initial venture in cross comparing new imaging methods, we performed the following 2 studies, locating motor cortex with echoplanar BOLD fMRI and TMS. The two methods can be readily integrated, with concurring results, although each have important limitations.     

Use of insulin-like growth factor I (IGF-I) and IGF-binding protein measurements to monitor feeding of premature infants

To determine whether peptides of the insulin-like growth factor (IGF) system might be useful indicators of nutritional adequacy in premature infants, we studied 50 premature (25-34 weeks gestation) infants prospectively to define the relationship between nutrient intake and serum concentrations of IGF-I, IGF-binding protein-2 (IGFBP-2), and IGFBP-3. Each infant was monitored for at least 2 weeks. Nutrient intake was quantified from daily logs; weight was determined daily, and measurements of IGF-I, IGFBP-2, and IGFBP-3 in serum were made twice weekly. Serum IGF-I correlated strongly with length of gestation, increasing 4.03 +/- 0.95 ng/mL for each additional week of gestation (P < 0.0001) and 0.36 +/- 0.07 ng/mL day each day since birth (P < 0.0001). A higher intake of calories increased IGF-I by 0.07 +/- 0.01 ng/mL for each calorie per kg ingested over the previous 3 days (P < 0.0001). IGF-I increased quadratically as protein intake increased. For each change of 1% in calories as protein squared, IGF-I increased 0.36 +/- 0.11 ng/mL (P < 0.0001). Serum IGFBP-3 concentrations also correlated with length of gestation, increasing 25.06 +/- 11.83 micrograms/L.wk (P = 0.035) and 4.14 +/- 1.33 micrograms/.day since birth (P = 0.003). Unlike IGF-I, variation in the amount of protein supplied did not change IGFBP-3. As calorie intake increased, IGFBP-3 increased by 0.54 +/- 0.17 microgram/L for each calorie per kg consumed over the previous 3 days (P = 0.0015). In contrast to IGF-I and IGFBP-3, IGFBP-2 declined as the length of gestation increased (56.12 +/- 16.92 ng/mL.week; P = 0.001) and with each additional day of life (7.57 +/- 2.44 ng/mL.day; P = 0.003). Dietary protein, the predominant regulator of IGFBP-2, caused a decrease of 33.22 +/- 9.00 ng/mL with each percent increase in dietary calories as protein (P < 0.0003). Calorie intake had less effect on IGFBP-2 than protein intake. These results indicate that each of the three peptides studied is regulated in premature infants by nutritional intake, and that their regulatory patterns are qualitatively similar to those observed in older individuals. Measurements of these peptides in premature infants may be useful indicators of nutritional status and adequacy of nutrient intake.     

Intravenous RMP-7 increases delivery of ganciclovir into rat brain tumors and enhances the effects of herpes simplex virus thymidine kinase gene therapy

Herpes simplex virus thymidine kinase (HSV-tk) gene therapy for brain tumors depends on ganciclovir (GCV) and its transport across the blood-brain tumor barrier (BBTB). We examined whether RMP-7, the bradykinin analog and potent BBTB permeabilizer, could enhance the efficacy of GCV treatment of brain tumors by increasing the BBTB delivery of GCV. In vitro, a significant bystander cytocidal effect of GCV was shown in mixed HSV-tk-transduced (HSV-tk+) and control vector-transduced (HSV-tk-) C6 glioma cultures. A dose-dependent cytotoxic effect of GCV on untransformed C6 cells was also shown. In vivo, rats with 100% HSV-tk+ or 100% HSV-tk- intracerebral C6 gliomas were treated for 7 days with intravenous infusions of GCV alone or with GCV and RMP-7 (2.5 microg/kg/day). The growth of HSV-tk+ and HSV-tk- gliomas decreased with increasing doses of GCV. A high dosage (100 mg of GCV/kg/day) eradicated all HSV-tk- and HSV-tk+ tumors. An intermediate dosage (5 mg of GCV/kg/day) reduced the growth of HSV-tk- gliomas by 42% if given alone, and by 88% in combination with RMP-7. A low dosage (0.5 mg of GCV/kg/day) in combination with RMP-7 enhanced the regression of HSV-tk+ gliomas by 87% compared with GCV alone. Low-dose GCV was ineffective in HSV-tk- tumors. RMP-7 increased [3H] GCV tumoral uptake by 2.6- and 1.7-fold in the tumor center and periphery, respectively. We conclude that RMP-7 could be an important adjunctive treatment for suicide gene therapy of brain tumors, while an RMP-7/GCV combination may also have a significant antitumor effect in untransfected gliomas.     

Cytochrome P450 and dependent activities in unexposed and PAH-exposed terrestrial annelids

The cytochrome P450 system of the oligochaetes Eisenia f. fetida (tiger worm) and Enchytraeus crypticus (pot worm) was analysed using ethoxy-, pentoxy- and benzoxyresorufin as substrates for monooxygenase activity. Whole body microsomes of the earthworm E.f. fetida displayed PentROD activity in the range from 0.26 to 1.05 pmol mg protein-1 min-1 and BenzROD activity in the range from 0.14 to 0.30 pmol mg protein-1 min-1. Exposure of the animals for up to four weeks to 100 mg fluoranthene or benzo[a]pyrene kg-1 soil (dry weight) did not induce significant changes in the activity of these monooxygenases. In E. crypticus EROD activity was in the range from 2.10 to 6.18 pmol mg protein-1 min-1 and PentROD activity in the range from 1.75 to 4.78 pmol mg protein-1 min-1. Short-term exposure to BaP by feeding reduced the EROD activity significantly by 45%, but did not effect PentROD activity. After long-term (8 weeks) exposure to BaP in the agar-agar medium EROD activity was not changed but PentROD had decreased to zero. In both species cytochrome P420 and NADPH-cytochrome C reductase activity were present. In E.f. fetida microsomes are associated with the giant haemoglobin. Both can be separated by gel filtration on a Sepharose B2 column or by hydrophobic interaction chromatography after solubilisation with cholate. NADPH-cytochrome C reductase elutes together with haemoglobin. Cytochrome P420 is eluted with Emulgen 911 and can be further purified by ion exchange chromatography using HA-Ultrogel. By SDS-PAGE of the purified microsomal proteins three protein bands are visualised in the range of cytochrome P450 displaying an apparent molecular mass of 54, 56 and 58 kDa. Only the 54-kDa protein interacts weakly with perch (Perca fluviatilis) CYP1A antibodies, while two proteins with an apparent molecular mass of 65 and 71 kDa give a strong antibody signal.     

Dynamic phenotypic restructuring of the CD4 and CD8 T-cell subsets with age in healthy humans: a compartmental model analysis

The incidence of ulcer perforation in 1480 patients treated in the Bergen area of Norway between 1935 and 1990 was analyzed for daily (circadian), weekly (circaseptan), and yearly (circannual) time effects. A circadian rhythm was found overall that was reproducible and fairly stable across seasons, decades, and days of the week. After subgrouping, a circadian rhythm was found in younger patients, males, and duodenal perforations, while a 12 h (circasemidian) rhythm characterized ulcer perforation for women and for gastric ulcers. Duodenal perforations showed highest incidence in the afternoon, while gastric perforations showed a major peak around noon and a secondary peak near midnight. For duodenal ulcer perforation, the circannual pattern was characterized by a 6-month rhythm, with significantly higher incidence in May-June-July and in November-December in most subgroups. A circaseptan rhythm was not found, but there was a significantly higher incidence on Thursday-Friday as compared to Sunday-Monday. The pathophysiological mechanisms underlying the perforation of an ulcer thus seemed to show pronounced circadian and 6-month rhythmic variations, much less so circaseptan or circannual rhythms. While it is likely that exogenous environmental and/or societal factors play a significant role, variations in ulcer perforation may be related to endogenous biological rhythms in pathophysiological factors since the circadian pattern of duodenal perforation follows that for gastric acidity. Knowledge of the temporal patterns in peptic ulcer perforation and associated pathophysiologic factors should prove useful in optimizing the chronotherapeutic management of ulcer disease.     

Dynamic kinetic asymmetric cycloadditions of isocyanates to vinylaziridines

The first examples of the use of racemic vinylaziridines in a Pd-catalyzed dynamic kinetic asymmetric transformation have been examined. Optimization studies of the Pd-catalyzed addition of vinylaziridines to isocyanates revealed that the chiral ligand between trans-1,2-diaminocyclohexane and 2-diphenylphosphino-1-naphthoic acid is superior to that involving 2-diphenylphosphino benzoic acid. Surprisingly, high ee's required the use of an acid whose pKa was about 4.7 +/- 0.1 as a cocatalyst. Both acetic acid and hydroxybenzotriazole meet this requirement. Less electrophilic isocyanates (e.g., benzyl, p-methoxyphenyl) gave higher ee's than more electrophilic ones (phenyl or benzoyl). Both N-benzyl and N-arylaziridines react well to give good yields and ee's, whereas N-tosylaziridines gave lower ee's. A 1,1-disubstituted aziridine led to the formation of a tertiary C-N bond with ee's comparable to the formation of the secondary C-N bond. The products were easily reduced almost quantitatively to the sensitive imidazolidines which can be readily hydrolyzed to the vicinal diamines. The reactivity pattern is consistent with a Curtin-Hammett situation wherein the enantiodiscriminating event is the cyclization of a rapidly equilibrating dynamic pi-allyl palladium intermediate.