Developmental changes in tritium autoabsorption

Developmental changes in autoabsorption of tritium emissions were examined in 30 brain regions in the rat at Postnatal Days 0, 4, 7, 10, 14, 21, and 28 and adulthood. Rats received tritiated 2-deoxyglucose in vivo. Alternate brain sections were extracted in chloroform, and autoradiographs were developed from extracted and nonextracted sections. The ratio of optical density values in extracted vs nonextracted sections was used to determine autoabsorption for each structure. Three principal temporal patterns in the development of adult levels of autoabsorption, determined by the optical density ratios, were identified: (1) a minimal increase pattern in which autoabsorption rose only slightly between birth and adulthood; (2) a plateau pattern in which a rapid early increase was followed by stable values; and (3) a late increase pattern in which autoabsorption remained relatively constant until Postnatal Day 28, with a large increase between Day 28 and adulthood. In addition, optical density ratios fluctuated during the second postnatal week in close to one-third of the structures. The data suggest that developmental events affecting the ratio of gray to white matter produce substantial local variations in the development of adult levels of autoabsorption that are distinct for each structure. To correct for autoabsorption effects in ontogenetic studies using tritium autoradiography, it is necessary to determine directly the degree of autoabsorption at a particular time point for the structure of interest. Our results indicate that the technique of in vivo administration of tritiated 2-deoxyglucose followed by chloroform extraction appears to be a sensitive and reproducible method for assessing autoabsorption at all ages.     

Angiographic evidence of hemorrhagic myocardial infarction after intracoronary thrombolysis with streptokinase

The reperfusion of acutely ischemic myocardium by intracoronary streptokinase thrombolysis is an exciting new therapy for acute myocardial infarction (MI). It appears that successful thrombolysis and reperfusion in the first few hours after acute coronary occlusion may salvage myocardium and possibly improve prognosis. A potential adverse effect of reperfusion is the production of hemorrhage in the area of myocardial necrosis. We report on a patient with prompt, successful coronary thrombolysis by streptokinase infusion who showed angiographic evidence of a hemorrhagic MI.     

Concentration of tissue inhibitor of metalloproteinases (TIMP)-1 in ovine follicular fluid and serum

Tissue inhibitor of metalloproteinases (TIMP)-1 mRNA and protein localize within granulosal cells of post-gonadotropin-surge follicles and luteal tissue in ewes. Our objectives were to test the hypotheses that 1) follicular fluid concentration of TIMP-1 increases following a gonadotropin surge induced by LHRH agonist (Exp. 1) and 2) luteal status affects peripheral serum concentration of TIMP-1 (Exp. 2 and 3). In Exp. 1, the concentration of TIMP-1 within antral fluid from post-surge follicles (28.7 +/- 6.65 microg/mL) was greater (P < .02) than from pre-surge follicles (2.37 +/- 2.47 microg/mL). In Exp. 2, serum concentration of TIMP-1 did not differ among d 0 to 6 (1.27 +/- .55 microg/mL) of the estrous cycle or among periods of luteal maintenance (1.29 +/- .06 microg/mL), spontaneous luteal regression (1.19 +/- .09 microg/mL), or luteal development (1.22 +/- .08 microg/mL). However, serum concentration of TIMP-1 was greater ( P < .001) during the period of luteal maintenance (1.14 +/- .04 microg/mL) than during PGF2alpha-induced luteolysis (d 26; .85 +/- .06 microg/mL) and induced luteal absence (d 27 to 33; .95 +/- .05 microg/mL). In Exp. 3, ewes (n = 14) were bled daily from d 1 to 19 (d 0 = estrus) and at 12-min intervals for 6 h on d 3, 10, and 17. Although concentration of TIMP-1 varied considerably within and among ewes, mean concentration of TIMP-1 per ewe per day increased ( P < .05) from d 3 to 17. These data indicate that follicular fluid concentration of TIMP-1 increases following a gonadotropin surge, but the contribution of ovarian derived TIMP-1 to peripheral serum concentration is negligible.     

Motor development and the mind: the potential role of motor abilities as a determinant of aspects of perceptual development

Recent advances in the science of human movement have enabled developmental psychologists to discover unique patterns of organization and control in infant motor behavior and development, provoking a resurgence of interest in this topic. In this article, we emphasize the role that motor development may play in determining developmental sequences or "timetables" in other domains. Specifically, we argue that particular motor achievements may be integral to developments in the domains of haptic perception and depth perception. In both cases, there is a high degree of fit between the developmental sequence in which certain perceptual sensitivities unfold and the ages at which the corresponding motor abilities onset. The discussions may provide new contexts in which to consider the developments of haptic perception and depth perception. The general purpose, however, is to highlight the wide-ranging influence of motor development during infancy.     

Synthesis and solid state (13)c and (19)f NMR characterization of aliphatic and aromatic carboxylic Acid fluoride polymers

A new chemical/spectroscopic couple that differentiates aromatic from aliphatic carboxylic acid polymers was developed. The method is complementary to more traditional methods of identification (IR) and is applicable to the analysis of complex mixtures where IR determinations are complicated by extensive vibrational band overlap. The method entails (1) conversion of carboxylic acids into acid fluorides and (2) specific detection of the resonances of the acid fluoride carbon and of the carbon directly attached to the carbonyl carbon by solid state (19)F-(13)C cross polarization (CP)/MAS (13)C NMR. The assignment of the chemical shift of the latter resonance to either the sp(2) or sp(3) carbon resonance manifold specifies the nature of the acid functionality. The preparation of the acid fluoride derivatives of several polymers containing aliphatic and aromatic carboxylic acid functionality was evaluated using sulfur tetrafluoride (SF(4)), diethylaminosulfur trifluoride (DAST), cyanuric fluoride, and thionyl fluoride. Room temperature reactions using DAST in methylene chloride or neat SF(4) gave the acid fluorides in yields ≥90% for the acids studied. Aromatic acid fluoride yields were essentially quantitative. Aliphatic acid fluorides were contaminated with the anhydride of the acid. The acid fluoride polymers were characterized by solid state (13)C and (19)F MAS/NMR.     

Survival of patients with glioblastoma multiforme is not influenced by altered expression of p16, p53, EGFR, MDM2 or Bcl-2 genes

Deregulated expression of one or more growth control genes including p16, p53, EGF receptor (EGFR), MDM2 or Bcl-2 may contribute to the treatment resistance phenotype of GBM and generally poor patient survival. Clinically, GBM have been divided into two major groups defined by (1) histologic progression from a low grade tumor ("progressive" or "secondary" GBM) contrasted with (2) those which show initial clinical presentation without a prior history ("de novo" or "primary" GBM). Using molecular genetic analysis for p53 gene mutations together with immunophenotyping for overexpression of EGFR, up to four GBM variants can be distinguished, including the p53+/EGFR- progressive or the p53-/EGFR+ de novo variant. We examined the survival of 80 adult patients diagnosed with astrocytic GBM stratified by age category (>40, 41-60 or 61-80) to determine whether alterations in any one given growth control gene or whether different genetic variants of GBM (progressive versus de novo) were associated with different survival outcomes. Survival testing using Kaplan-Meier plots for GBM patients with or without altered expression of p16, p53, EGFR, MDM2 or Bcl-2 showed no significant differences by age group or by gene expression indicating a lack of prognostic value for GBM. Also the clinical outcome among patients with GBM showed no significant differences within each age category for any GBM variant including the progressive and de novo GBM variants indicating similar biologic behavior despite different genotypes. Using a pairwise comparison, one-third of the GBM with normal p16 expression showed accumulation of MDM2 protein and this association approached statistical significance (0.01 < P < 0.05) using the Bonferroni procedure. These GBM may represent a variant in which the p19ARF/MDM2/p53 pathway may be deregulated rather than the p16/cyclin D-CDK4/Rb pathway.     

Chronic solvent neurotoxicity in New Zealand: notified cases between 1993 and 1997

AIM: To report on cases of chronic solvent neurotoxicity notified to the Department of Labour between 1993 and 1997. METHODS: Previously published diagnostic criteria were used to classify notified cases as "verified", "not verified" or "not proven". Verified cases were further classified as Type 1 or 2(2) and analysed according to occupation, solvent type and length of exposure. RESULTS: Of 193 notified cases, 76 were classified as "verified". The majority were male (74/76) and European (69/76). Mean length of exposure to solvents for Type I cases was 10.6 years (SD 4.7) and for Type II cases 19.8 years (SD 8.4). Forty-three cases were classified as "mild" and 33 as "moderate". The most frequent occupation was spraypainting (39%), followed by printing (16%) and boatbuilding (9%). There was no correlation between severity of symptoms and type of solvent. There was a non-significant trend of increasing severity of symptoms with length of exposure. CONCLUSION: Exposure to solvents is an important health hazard in New Zealand workplaces.     

Reproduction of nuclei in Pelomyxa palustris

Light and electron micrographs were made of nuclei in Pelomyxa palustris, a unicellular, multinucleated giant amoeboid organism. We analyzed 1019 pelomyxae and classified their nuclei according to their location in the nuclear cycle. The majority of organisms (56.3%) had interphase nuclei, some of which contained spores of mostly 1-3 microns in diameter. The nuclei had disintegrated in 1.3% of organisms that appeared to have no nuclei. The remainder (42.4%) had nuclei in the form of spores (1 to 10 microns spheroids) that were in various stages of development and growth. Mitotic figures were seen in some of them, with several chromosome pairs per nucleus. Interchromosomal fibers were seen at anaphase, and newly formed "young" interphase nuclei were observed.