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Hyperammonemia is a consistent finding in many metabolic disorders. The excess ammonia (NH4Cl) interferes with brain energy metabolism possibly in part by inhibiting the tricarboxylic acid (TCA) cycle. Inhibition of the TCA cycle may result in depletion of ATP in the brain cells. In this study, the acute and chronic effect of NH4Cl (7.5 mM and 15 mM) on the metabolism of isolated neurons and neuroblastoma cells was examined. These cells were treated with NH4Cl for 15 minutes and 24 hours. Morphologic and metabolic toxicity were greater in neuroblastoma cells than in primary neurons. Following 15 minutes treatment, concentration of lactate increased significantly in neuroblastoma cells but, the concentration of other metabolites did not change significantly in neuroblastoma cells and in primary neurons. Following 24 hours treatment, the glucose utilization increased in both cell types. This high utilization of glucose in neuroblastoma cells was in concert with an increase in lactate and decrease in glutamate and ATP. In primary neurons, following 24 hours treatment, the glucose utilization significantly increased, but the concentration of the other metabolites did not change significantly. Neuroblastoma cells consumed more glucose than primary neurons in absence of NH4Cl, but generated the same amount of lactate as neurons. [ABSTRACT FROM AUTHOR]

The El Niño-Southern Oscillation is the dominant mode of interannual climate variability across the Pacific Ocean basin, with influence on the global climate. The two end members of the cycle, El Niño and La Niña, force anomalous oceanographic conditions and coastal response along the Pacific margin, exposing many heavily populated regions to increased coastal flooding and erosion hazards. However, a quantitative record of coastal impacts is spatially limited and temporally restricted to only the most recent events. Here we report on the oceanographic forcing and coastal response of the 2015-2016 El Niño, one of the strongest of the last 145 years. We show that winter wave energy equalled or exceeded measured historical maxima across the US West Coast, corresponding to anomalously large beach erosion across the region. Shorelines in many areas retreated beyond previously measured landward extremes, particularly along the sediment-starved California coast.

As the number of persons chronically prescribed antiretrovirals has grown and the realization that antiretrovirals are required to be continued for life, pharmaceutical manufacturers have developed new classes of agents, improved the pharmacokinetics of marketed products through dosing reformulations, and in an effort to maximize success with respect to adherence, compiled into a single dosing unit all necessary elements for an antiretroviral regimen. Atriplatrade mark represents the first ever fixed-dose combination antiretroviral available. This article reviews currently available data on this agent, the impact of resistance on clinical use and implementation, as well as extensive descriptions of the pharmacokinetics, adverse effects and drug-interactions warranting consideration. Whether beginning in a naïve patient or switching from other regimens for tolerability issues, Atriplatrade mark represents a viable option. Its demonstrated advantages with respect to lipid and hematologic parameters and equivalent incidence of renal toxicity are tempered by the findings of bone mineral density decreases, however. Combining multiple mechanisms of action in a single dosing unit appears to improve efficacy, increase the likelihood for adherence and maintain viral suppression compared to administering these agents independently. It is suggested other pharmaceutical companies assess the potential to replicate this for the remaining antiretrovirals.

Objective: To assess laboratory performance, use, and limitations in the joint College of American Pathologists and American College of Medical Genetics proficiency testing program for laboratories performing cytogenetic tests based on fluorescence in situ hybridization (FISH)., Data Sources: Eight proficiency surveys dealing with FISH detection of microdeletions or microduplications, aneuploidy in interphase cells, gene amplification, and neoplasm-specific translocations. Participating laboratories used their own DNA probes (commercial or home-brew), hybridization methods, and analytic criteria to answer clinical questions about cases represented by slides included in the survey materials. They also described their test results according to the International System for Human Cytogenetic Nomenclature (ISCN) and answered supplementary questions relating to their experience with the subject test systems., Data Extraction: In addition to evaluating diagnostic accuracy, we evaluated survey use, laboratory experience, variation in methodologic approach, and the practicality of using ISCN nomenclature for describing test results., Synthesis and Conclusions: With the exception of one challenge, at least 80% of the participants reached the correct diagnostic conclusion. In the sole exception, there was still a consensus of 91.7% of participants with the same (albeit erroneous) diagnostic conclusion. The overall outstanding performance of participating laboratories clearly shows the reliability of current FISH methods. Despite the fact that a large number of laboratories reported little or no experience with the specific test systems, the overwhelming majority performed very well. This result shows that the program's strategy of targeting classes of abnormalities (vs a single abnormality associated with a specific disease) did not put at a disadvantage participants who did not routinely perform all of the potential tests in the class. The extraordinary variation in ISCN descriptions submitted by participants showed that the existing system for human cytogenetic nomenclature is not suitable for facile communication of FISH test results.

We report on an infant with Weaver syndrome, neoplasia and cardiovascular anomalies. Stage 4S neuroblastoma underwent spontaneous resolution. Three neoplasms have been reported in Weaver syndrome: another stage 4S neuroblastoma [Muhonen and Menezes, 1990: J Pediatr 116:596-599], an ovarian endodermal sinus tumor [Derry et al., 1999: J Med Genet 36:725-728], and a sacrococcygeal teratoma [Kelly et al., 2000: Am J Med Genet 95:492-495]. No case was associated with cardiovascular anomalies. Our patient had VSD and PDA, and although several other patients with Weaver syndrome have had cardiovascular anomalies, they were shown not to have neoplasia., (Copyright 2001 Wiley-Liss. Inc.)

The present experiments were conducted to investigate the direct effects of ethanol on the energy metabolism of astrocytes and C6-glioma cells. Primary astrocytes were prepared from cerebral cortices of neonatal rats, and C6-glioma cells were purchased from American Type Culture Collection (ATCC). These cells were exposed to different concentrations of alcohol (100 mM, 200 mM, and 300 mM) for 15 minutes and 24 hours. The amount of ATP and PCr was measured by the method of Lowry and Passonneau (1972). Following 15 minutes treatment with different doses of ethanol the amount of ATP and PCr increased, in both cell types. Only the increase of ATP concentration with varying doses of ethanol (100 mM, 200 mM, and 300 mM) was statistically significant. Following 24 hours treatment of astrocytes with different doses of ethanol the concentration of ATP and PCr decreased. The decrease in concentration of ATP was significant with all three doses of ethanol, but the decrease of PCr concentration was only statistically significant with 300 mM ethanol. Following 24 hours treatment of C6-glioma cells to varying doses of ethanol, the concentration of PCr and ATP decreased. The decrease of PCr was statistically significant with all three doses of ethanol and the decrease of ATP concentration was only significant with 300 mM ethanol.

Inflammatory liposarcoma is an unusual variant of well-differentiated liposarcoma. We report on the fine-needle aspiration (FNA) cytology findings of a retroperitoneal well-differentiated inflammatory liposarcoma from a 63-yr-old white female. The smears showed numerous dispersed inflammatory cells, with the majority being reactive lymphoid cells and plasma cells. There were scattered, large, atypical cells containing multiple or hyperlobated nuclei with coarse chromatin and abundant ill-defined cytoplasm. The large atypical cells, as well as the inflammatory cells, were also found within the fibrous tissue fragments. The follow-up surgical resection of the tumor demonstrated a well-differentiated inflammatory liposarcoma with coexistent dedifferentiated areas and lipoma-like, well-differentiated liposarcoma. With the appropriate anatomic and radiographic settings, the FNA cytology findings of abundant, reactive inflammatory cells and scattered, large, atypical tumor cells that are CD15-, CD30-, and cytokeratin-negative are highly suggestive of a well-differentiated inflammatory liposarcoma.

Valproic acid (VPA) is a commonly used antiepileptic agent that recently has been found useful in the treatment of affective disorders and prophylaxis of migraine. VPA induces congenital malformations, especially spina bifida, in the offspring of women treated with this agent during early pregnancy. The mechanism by which VPA induces abnormal development remains unknown despite many studies in experimental animals in which VPA causes malformations similar to those seen in human infants. Because of its chemical structure as a weak organic acid and its capability to induce postaxial forelimb ectrodactyly in C57BL/6 mice, we postulated that VPA acts to perturb limb morphogenesis by reducing embryonic intracellular pH (pHi). We administered VPA, 200 to 400 mg/kg, to C57BL/6 mice on day 9 of gestation. A dose-dependent incidence of postaxial forelimb ectrodactyly was observed. Forelimb bud pHi was estimated by computer-assisted image analysis from the transplacental distribution of 14C-DMO. At the highest doses, 300 and 400 mg/kg, a decrease of pHi of 0.2 to 0.3 pH units was observed uniformly throughout the limb bud 1 h after VPA treatment. None of these changes were seen after treatment with 2-en VPA, a nonteratogenic analog of VPA. Furthermore, the capability of VPA to induce postaxial forelimb ectrodactyly was greatly enhanced by coadministration of agents that inhibit pHi regulatory processes. These data support the hypothesis that VPA-induced postaxial ectrodactyly in murine fetuses can be attributed to reduction in limb bud pHi.

Brain tissue cells have been shown to use two predominant pathways for energy production. The first of these is the pentose phosphate shunt, and the second is glycolysis, followed by the TCA cycle. Inhibition of these pathways can result in a reduction of ATP, and changes in the concentration of various metabolites. In the present study, the acute and chronic effect of 6-aminonicotinamide (6-AN) (0.01, 0.02, and 0.03 mg/ml) was examined on astrocytes and C6-glioma cells. Following this treatment, glucose, lactate, glutamate, ATP, and PCr were assayed according to the procedures of Lowry and Passonneau. Our data indicated that following 15 minutes treatment of astrocytes and C6-glioma with 6AN there was no significant difference in the concentration of metabolites measured. However, following 24 hours treatment there was a significant increase in glucose concentration and significant reduction in the concentration of ATP, PCr, lactate and glutamate in both cell types. Morphological changes appeared later following 48 hours treatment with 6-AN in both cell types. Glucose accumulation can be explained by the fact that it is the precursor to both glycolysis and the pentose phosphate shunt. If these processes are inhibited, glucose will obviously accumulate and products like ATP, PCr, lactate and glutamate will decrease. Additionally, there was significant differences in concentration of glucose and lactate between astrocytes and C6-glioma cells. The significance of these differences has been discussed.

Using the transplacental distribution of the weak acid 5,5-dimethyloxazolidine-2,4-dione (DMO), a computer assisted imaging technique has been developed to permit the estimation of intracellular pH (pHi) in very specific areas of the developing rodent embryo. The study reported here demonstrates the heterogeneity of radiolabeled DMO distribution in the developing mouse forelimb. The pattern of pHi distribution shifts from one of high pHi values in the proximal core of the mesoderm on day 10 of gestation to one of higher pHi values in the mesoderm just underlying the ectoderm on day 11. Studies [Scott et al. (1990) Toxicol. Appl. Pharmacol. 103:238-254] in which DMO concentration was monitored following treatment with acetazolamide or acetazolamide plus amiloride were done in whole embryo homogenates or pooled limb samples which allow for the calculation of an average pHi but may not reflect the pHi in very specific locations of the limb. Two hours after acetazolamide administration, the pHi pattern was not significantly changed from control. Intracellular pH was raised above control levels but was not significant statistically except in the peripheral mesoderm in the ventral third of the forelimb. Fifteen hours after acetazolamide treatment, there was a significant decrease in pHi values with no change in pattern. However, treatment with acetazolamide plus amiloride for 15 hr produced a marked reduction of pHi values throughout the forelimb bud. Changes in bromodeoxyuridine labeling index (an indication of proliferative activity) following treatment with acetazolamide or acetazolamide plus amiloride are reported. The combination treatment reduced the labeling index by approximately 15% below that of control embryos in the limb region where absence of digit(s) will occur. However, we found no overall correlation of proliferative rate and pHi of limb bud mesoderm in treated embryos. Consequently, we were unable to causally associate reduced pHi with decreased proliferative rate.

Methoxyacetic acid (MAA), a weak acid with a pKa of 3.57, was used to test the broad hypothesis that distribution of weak acids in maternal and fetal tissues is determined principally by the pKa of the acid and the pH values of tissue and fluid compartments and to examine tissue dose-teratogenesis relationships, as well as administered dose-teratogenesis relationships. Five related experimental studies were conducted in pregnant C57BL/6CrIBR mice: a conventional dose-response study of developmental toxicity and transplacental pharmacokinetics in mice, a second dose-response study in which reproductive outcomes in litters from individual dams were related to individual pharmacokinetic behavior, a protein-binding experiment, an embryo tissue localization study, and determination of pH in maternal and embryonic compartments after exposure to MAA. MAA was administered intraperitoneally at 9:00 a.m. on day 10 of gestation, at doses ranging from 88 to 164 mg/kg. Localization within the forelimb bud of the embryo, an MAA target site, was determined by computerized image analysis of the distribution of radiolabeled MAA. The kinetic predictions of a physiologically based model incorporating tissue pH values and MAA pKa agreed well with observed concentrations at the lowest dose. However, at intermediate and higher doses, concentrations in both maternal and embryonic tissues were consistently underestimated. MAA was bound neither to maternal plasma proteins nor to embryonic proteins. Intermediate and higher doses of MAA caused dose-dependent transient depressions in tissue pH, but these were not of sufficient duration to bring predicted tissue concentrations into congruence with the concentrations observed. Distribution of MAA within the forelimb bud was broadly consistent with the pH hypothesis, but MAA concentration was not increased in the distal postaxial sector that is the site of the precursor cells of the missing digits. Internal exposure to MAA, defined as the area under the maternal plasma or embryo concentration curve (AUC), was not proportional to administered dose, but AUC-response relationships generated by the group and individual dose-response studies were comparable. While AUC may be a useful measure of effective MAA dose, it cannot be accurately predicted at teratogenic doses of this agent by the model as it is presently structured.

Bilateral ischemia has been shown to alter the net brain levels of energy metabolites such as ATP, phosphocreatine, glucose, and glycogen. The amino acid neurotransmitter gamma-aminobutyric acid (GABA) exerts a tonic inhibitory influence on neural activity. The present studies were designed to evaluate the influence of elevated GABA levels on the metabolic sequelae of ischemia. The GABA transaminase inhibitor gamma-vinyl-GABA (GVG; vigabatrin) was administered to Mongolian gerbils before the production of a bilateral ischemic incident. GABA levels were elevated in all regions assayed. Levels of energy metabolites were also increased, an indication of reduced energy utilization. In control animals, in the absence of GVG, 1 min of bilateral ischemia produced decreases in the levels of all metabolites. In animals pretreated with GVG, the effects of 1 min of bilateral ischemia were attenuated. These data suggest that the level of ongoing activity may affect the response to an ischemic insult. Furthermore, GVG may have a clinical indication in reducing the effect of minor ischemic incidents.

The hippocampus exhibits a post-ictal phenomenon in which it is unresponsive to further stimulation. It has been suggested that this loss of excitability is the basis of post-seizure amnesia. The biochemical events associated with this phenomenon are unclear. In the present study, energy metabolites were measured in the stratum oriens, stratum pyramidale and stratum radiatum in rat hippocampus, and correlated with field potential recordings. Wistar rats were anesthetized and the calvarium removed. Following removal of the cortex by aspiration, the hippocampus was covered with oil, and stimulating and recording electrodes were placed. Stimulation consisted of a train of stimuli at 100 Hz (10-20 m Amps). This stimulation was found to be effective in evoking self-sustaining after-discharges and post-ictal depression. Tissues for metabolite analysis were taken from a series of controls, from animals during active self-sustaining seizures, and from animals which were totally unresponsive to further electrical stimulation. Hippocampal tissue for metabolite analysis was obtained by pouring liquid N2 on the exposed tissue, then removing the frozen tissue. Glucose, ATP, and phosphocreatine were measured in hippocampal layers of CA1 using fluorescence techniques and enzymatic cycling. Results showed that during seizure activity, glucose, ATP, and phosphocreatine were all decreased from 40-80% in the three layers of the hippocampus, whereas from 60 seconds after the onset of hippocampal shutdown, energy metabolites had returned toward normal. Thus, at a time when the hippocampus was unresponsive, energy metabolites were at control levels. These data suggest that the shutdown phenomenon occurs in the presence of adequate energy stores.