Maternal copper deficiency perpetuates altered vascular function in Sprague-Dawley rat offspring.

Little is known about the consequences of maternal copper (Cu) deficiency on the vascular function of offspring or on perpetuation of vascular effects to a second generation. We examined vascular functional responses in mesenteric arteries from Cu-deficient Sprague-Dawley rat dams and from offspring directly exposed to maternal Cu deficiency during development and lactation and perpetuation of the effects in a second generation of offspring. Dams were fed a diet with marginal (1 mg Cu/kg) or adequate (6 mg Cu/kg) Cu for 3 weeks before conception and throughout pregnancy and lactation periods. Half of the first generation (F1) litters were cross-fostered. At reproductive maturity, F1 pairs were bred within groups resulting in second generation (F2) offspring. At 9 weeks of age, mesenteric artery (200 µm) isometric tension was determined in response to vasoconstrictors and vasorelaxants using a small artery wire myograph. Cu deficiency did not alter the vascular function in dams. In F1 offspring, increased responsiveness to potassium chloride in male offspring was due to direct exposure to maternal Cu deficiency in the birth mother, while enhanced endothelium-dependent relaxation responses in female offspring resulted from postnatal exposure to maternal Cu deficiency. Increased endothelium independent and decreased endothelium-dependent relaxation responses were identified in F2 Cu-deficient male offspring. These data indicate that exposure to maternal Cu deficiency during critical windows of development alter the vascular function across two generations of offspring.

The lakes of Titan.

The surface of Saturn's haze-shrouded moon Titan has long been proposed to have oceans or lakes, on the basis of the stability of liquid methane at the surface. Initial visible and radar imaging failed to find any evidence of an ocean, although abundant evidence was found that flowing liquids have existed on the surface. Here we provide definitive evidence for the presence of lakes on the surface of Titan, obtained during the Cassini Radar flyby of Titan on 22 July 2006 (T16). The radar imaging polewards of 70 degrees north shows more than 75 circular to irregular radar-dark patches, in a region where liquid methane and ethane are expected to be abundant and stable on the surface. The radar-dark patches are interpreted as lakes on the basis of their very low radar reflectivity and morphological similarities to lakes, including associated channels and location in topographic depressions. Some of the lakes do not completely fill the depressions in which they lie, and apparently dry depressions are present. We interpret this to indicate that lakes are present in a number of states, including partly dry and liquid-filled. These northern-hemisphere lakes constitute the strongest evidence yet that a condensable-liquid hydrological cycle is active in Titan's surface and atmosphere, in which the lakes are filled through rainfall and/or intersection with the subsurface 'liquid methane' table.

The Footprint method to assess transmalleolar axis.

Torsional deformities of the lower extremities are a common reason for an orthopaedic consultation and are also part of the evaluation of a patient in gait analysis. This study assessed the level of agreement between, and the repeatability of, the Footprint method and two other methods (Prone and Jig) of measuring the transmalleolar axis (TMA) clinically. The Footprint method measures the TMA as the patient sits by projecting the position of the malleoli downwards onto lined paper while the lines of the paper are aligned with the knee axis. The Prone method projects the position of the malleoli upwards onto the sole of the foot and this is related to the visually estimated knee axis. The Jig method uses a tropometer to relate the angle between the tibial tubercle and the two malleoli. Two assessors measured twelve subjects using the three methods and six subjects were re-measured approximately 1 week later for repeatability. There was poor agreement between the three methods but the Footprint method was the most repeatable (coefficient of repeatability: 5.4). One observer then assessed the repeatability of the effect of simulated equinus on the Footprint method in 10 normal subjects on 2 separate occasions 1 week apart. Equinus was obtained by having the subjects sit and firstly extend their knee and place the foot on the floor and secondly by placing the foot under consideration on a wedge. Both conditions introduced an offset into the measurement of the TMA when compared to the measurements with the ankle at neutral in the same subjects. The reliability of the Footprint method was then assessed using 10 inexperienced observers who measured nine normal subjects each on 2 separate occasions and their results compared with those from an experienced observer. The inexperienced observers were less repeatable than an experienced observer (coefficients of repeatability 9.2 and 6.9, respectively). We recommend that different methods of measuring TMA should not be used interchangeably in clinical practice. The Footprint method was the most repeatable of the three methods tested and can be used for patients who have fixed equinus but the measurement was less repeatable when used by inexperienced observers.

Ultra-relativistic electrons in Jupiter's radiation belts.

Ground-based observations have shown that Jupiter is a two-component source of microwave radio emission: thermal atmospheric emission and synchrotron emission from energetic electrons spiralling in Jupiter's magnetic field. Later in situ measurements confirmed the existence of Jupiter's high-energy electron-radiation belts, with evidence for electrons at energies up to 20[?]MeV. Although most radiation belt models predict electrons at higher energies, adiabatic diffusion theory can account only for energies up to around 20[?]MeV. Unambiguous evidence for more energetic electrons is lacking. Here we report observations of 13.8[?]GHz synchrotron emission that confirm the presence of electrons with energies up to 50[?]MeV; the data were collected during the Cassini fly-by of Jupiter. These energetic electrons may be repeatedly accelerated through an interaction with plasma waves, which can transfer energy into the electrons. Preliminary comparison of our data with model results suggests that electrons with energies of less than 20[?]MeV are more numerous than previously believed.

Dietary copper and dimethylhydrazine affect protein kinase C isozyme protein and mRNA expression and the formation of aberrant crypts in colon of rats.

Low dietary copper has been shown to decrease the expression of various protein kinase C (PKC) isozymes and increase the risk of colon cancer development in experimental animals. The purpose of this study was to investigate the relationship between dietary copper and carcinogen administration on PKC isozyme accumulation and aberrant crypt foci (ACF) formation in rats fed 0.9 and 7.7 microg Cu/g diet. After 24 and 31 d on the diets, the rats were injected with either dimethylhydrazine (DMH) (25 mg/kg i.p.) or saline and killed at two time points (2 wk and 8 wk after DMH). Rats fed low dietary copper had significantly lower (p<0.0001) hematocrits, hemoglobin, ceruloplasmin activity and plasma and liver copper concentrations than rats fed adequate dietary copper. Ingestion of low dietary copper significantly (p<0.005) increased the formation of DMH-induced ACF (116.8 vs 59.6). Low dietary copper significantly (p<0.05) decreased the concentration of PKC alpha, delta, and zeta in the colon at 2 wk but not at 8 wk. Thus, changes in PKC isoform protein concentration may be related to increased susceptibility of copper-deficient animals to colon cancer.

Influence of hydroxyl substitution on benzyne properties. quantum chemical characterization of the didehydrophenols.

Geometries and singlet-triplet splittings for the 10 geometrical isomers of didehydrophenol are characterized at a variety of levels of electronic structure theory. The influence of the hydroxyl group is primarily to increase/decrease the weight of zwitterionic singlet mesomers that place positive/negative charge adjacent to oxygen in valence bond descriptions of the arynes. For some of the meta isomers, this interaction stabilizes distortion in the direction of a bicyclic geometry. The net effect, relative to the unsubstituted benzynes, is to increase the singlet-triplet splittings in 2,3-, 2,6-, and 3,5-didehydrophenol and to decrease that splitting in 2,4- and 2,5-didehydrophenol (3,4-didehydrophenol is essentially unaffected). As shown for other arynes, the singlet-triplet splittings can also be accurately estimated by correlation with proton hyperfine coupling constants in antecedent monoradicals, these values being accessible from very economical calculations.

Mitochondrial oxidant generation and oxidative damage in Ames dwarf and GH transgenic mice.

Aging is associated with an accumulation of oxidative damage to proteins, lipids and DNA. Cellular mechanisms designed to prevent oxidative damage decline with aging and in diseases associated with aging. A long-lived mouse, the Ames dwarf, exhibits growth hormone deficiency and heightened antioxidative defenses. In contrast, animals that over express GH have suppressed antioxidative capacity and live half as long as wild type mice. In this study, we examined the generation of H2O2 from liver mitochondria of Ames dwarf and wild type mice and determined the level of oxidative damage to proteins, lipids and DNA in various tissues of these animals. Dwarf liver mitochondria (24 months) produced less H2O2 than normal liver in the presence of succinate (p<0.03) and ADP (p<0.003). Levels of oxidative DNA damage (8ÕHdG) were variable and dependent on tissue and age in dwarf and normal mice. Forty-seven percent fewer protein carbonyls were detected in 24-month old dwarf liver tissue compared to controls (p<0.04). Forty percent more (p<0.04) protein carbonyls were detected in liver tissue (3-month old) of GH transgenic mice compared to wild types while 12 month old brain tissue had 53% more protein carbonyls compared to controls (p<0.005). Levels of liver malonaldehyde (lipid peroxidation) were not different at 3 and 12 months of age but were greater in Ames dwarf mice at 24 months compared to normal mice. Previous studies indicate a strong negative correlation between plasma GH levels and antioxidative defense. Taken together, these studies show that altered GH-signaling may contribute to differences in the generation of reactive oxygen species, the ability to counter oxidative stress and life span.

Gender influences the effect of perinatal copper deficiency on cerebellar PKC gamma content.

Change in cerebellar protein kinase C gamma (PKCgamma) content caused by perinatal copper (Cu) deficiency was determined in 22-day old rats. The offspring of dams with low Cu intake during gestation and lactation exhibited signs characteristic of Cu deficiency including anemia, greater than 90% reduction in liver Cu concentration, and undetectable serum ceruloplasmin. In addition, brain Cu concentrations were reduced 80%. No differences in the signs of Cu deficiency were observed between female and male offspring. However, cerebellar PKCgamma content was reduced 54% (P < 0.05, Tukey's test) in female offspring but only 18% (P > 0.05) in male offspring. Following 6 weeks of Cu supplementation, brain Cu concentrations remained depressed in female and male rats that experienced perinatal Cu deficiency, but cerebellar PKCgamma content was completely restored to control levels. Postnatal expression of PKCgamma in the cerebellum coincides with and regulates cerebellar maturation. The results of the present study indicate perinatal Cu deficiency may impair cerebellar maturation to a greater extent in females than in males. However, it is not clear whether suppression of PKCgamma by perinatal Cu deficiency produces permanent neuropathology in the cerebellum because the effects were reversed by Cu supplementation.

A comparison of the effects of two burs on endodontic access in all-ceramic high lucite crowns.

OBJECTIVE: The purpose of this study was to examine and compare the effects of diamond and tungsten carbide burs with respect to the preparation of access through all-ceramic crowns. STUDY DESIGN: Thirty extracted maxillary premolars were restored with all-ceramic crowns. Each specimen was assigned to one of two groups: (1) access opening prepared with a round diamond bur; (2) access opening prepared with a carbide fissure bur. Access preparations were scanned by means of scanning electron microscopy; observed were defects categorized as edge chipping, microcracks, and fractures. RESULTS: Edge chipping around the access was universal. Significant chipping (x > or = 0.1 m) was seen in 43% of access peripheries. Eleven percent of the crowns fractured. chi(2) analysis (P <.05) demonstrated no statistical difference between the bur groups. Results of a t test revealed no statistical difference in edge chipping between the two bur types. CONCLUSIONS: All-ceramic crowns bonded to extracted maxillary premolars may experience edge chipping, microcracks, and fractures at equal rates whether access is prepared with a round medium coarse diamond bur or a tungsten carbide fissure bur.

Lipid lowering explains the insulin sensitivity enhancing effects of a thiazolidinedione, 5-(4-(2-(2-phenyl-4-oxazolyl)ethoxy)benzyl)-2,4 thiazolidinedione.

AIM: Insulin resistance is a characteristic feature of type 2 diabetes and obesity. The present study examined the effects of TZD300512, a thiazolidinedione, on glucose and lipid metabolism in the fatty Zucker rat (fa/fa), a rat model of insulin resistance. METHODS: TZD300512 was administered (2.0 mg/kg/day) in the diet for 1 week to chronically catheterized Zucker fa/fa rats. We measured triglyceride clearance rate and hepatic triglyceride output. We assessed baseline glucose metabolism, and insulin-mediated glucose uptake. We also determined whether the insulin sensitivity enhancing effects of TZD300512 could be reversed by infusion of Intralipid. RESULTS: TZD300512 treatment markedly reduced fasting plasma triglyceride by 72% and nonesterified free fatty acids by 46%. Moreover, treatment significantly enhanced plasma triglyceride clearance (AUC; 60.36+/-11.50 v 131.44+/-18.45 mM/min), but hepatic triglyceride output was not altered. Drug treatment significantly reduced fasting plasma glucose by 25%, plasma insulin by 73%, and had no effect on glucagon levels. Glucose infusion rate (GIR) needed to maintain euglycemia during hyperinsulinemic clamp was significantly increased from 34.96+/-3.94 micromol/kg/min to 123.80+/-4.80 micromol/kg/min, while whole body glucose uptake was more than doubled (58.49+/-2.86 control vs. 126.97+/-3.8 treated micromol/kg/min). Insulin-induced suppression of hepatic glucose production was nearly complete with treatment. Intralipid infusion reversed drug-induced improvement in insulin sensitivity. CONCLUSIONS: These results suggest that TZD300512-favourable alterations in lipid metabolism have a significant impact on its effectiveness in enhancing insulin sensitivity in a severely insulin resistant rodent model of type 2 diabetes.

Growth stimulation of Porphyromonas endodontalis by hemoglobin and protoporphyrin IX.

Porphyromonas endodontalis, like other Porphyromonas species, has a complex set of nutritional requirements. In addition to being an obligate anaerobe, the bacterium must be grown in a complex medium consisting of amino acids, reducing agents and heme compounds. P. endodontalis accumulates high concentrations of heme pigments to the extent that colonies appear black on blood agar. This accumulation of heme and the need for these compounds has been characterized as iron requirements by these species. However, in our studies, P. endodontalis demonstrated growth dependence on hemoglobin or protoporphyrin IX but not on free iron. Iron added to other heme compounds actually decreased growth stimulation by porphyrin-containing compounds. P. endodontalis actively transported free iron, but this process did not appear to be critical for growth. The maximum stimulation of growth by protoporphyrin IX, under conditions of iron deprivation, suggests that P. endodontalis requires the porphyrin moiety as a growth factor.

Maternal Copper Deficiency Impairs the Developmental Expression of Protein Kinase C α, ß and γ Isoforms in Neonatal Rat Brain.

Although brain development and neurological function are impaired in the offspring of rodents that consume copper-deficient diets during pregnancy and lactation, the underlying mechanisms for the impairment are not well understood. Because protein kinase C (PKC) has been implicated in regulating development of the central nervous system, the present study was conducted to determine if maternal copper intake during pregnancy and lactation influences the expression of PKC in the developing brains of neonatal rats. Dams were fed diets containing either 1 µg Cu/g (Cu1), 2 µg Cu/g (Cu2), or 6 µg Cu/g (Cu6) beginning three weeks before pregnancy and ending 21 days after parturition. The α, ß, and γ isoforms of PKC increased in the cytosolic fraction of neonatal brain during the 21 days following parturition, but the rates of increase for PKCß and γ were significantly reduced in neonates of dams consuming Cu1 and Cu2. In a second experiment, PKCß content in the cytosolic fraction of the hypothalamus and PKCγ content in the cytosolic fraction of the cerebellum were significantly lowered in 21-day-old pups of dams consuming Cu1 and Cu2. These data indicate that maternal diets that are deficient in copper impair the expression of PKCß, and γ in the developing brain of neonatal rats.

Radiologic interpretation of bone striae: an experimental study in vitro.

OBJECTIVE: The purpose of this study was to determine whether the mandibular alveolar striae patterns seen in radiographs represent trabecular bone. STUDY DESIGN: Segments of human cadaver mandible were obtained. Two identical radiographs were made of each segment initially, after removal of trabecular bone, after slight smoothing of the endosteal surface, and after aggressive smoothing of the endosteal surface. The radiographs were projected in random pairs for each sample. Six dentists judged whether a difference in the amount of trabecular bone could be detected. RESULTS: Chi-square test analysis revealed no significant difference in the amount of trabecular bone judged initially and after removal of trabecular bone. A significant difference appeared to exist on radiographs made initially and after slight smoothing. A significant difference was judged to exist on radiographs made after slight removal of the endosteal surface and after aggressive removal of the endosteal surface. CONCLUSIONS: Mandibular radiographic striae patterns, interpreted as arising from trabecular bone, actually result from bone patterns on the endosteal surface.

Copper and signal transduction: platelets as a model to determine the role of copper in stimulus-response coupling.

Platelets from copper-deficient rats have been used as a model to investigate the role of copper in receptor-mediated cellular responses. Copper deficiency doubles the rate of dense granule secretion and increases myosin association with the platelet cytoskeleton following thrombin stimulation. Mechanisms underlying the effects of copper deficiency on thrombin-induced signals that elicit dense granule secretion involve suppression of protein kinase C activity and impairment of Ca2+ release from intracellular stores. Copper deficiency also reduces the cellular GTP content of platelets. This may limit receptor effector coupling through GTP-dependent regulatory proteins leading to protein kinase C activation and the release of Ca2+ from intracellular stores. The reduction in GTP content during copper deficiency results from its utilization to maintain cellular ATP levels in response to severely inhibited cytochrome c oxidase activity in platelet mitochondria. Thus, the role of copper in maintaining normal signal transduction may be indirectly related to its biological function in mitochondria.

Copper deprivation potentiates oxidative stress in HL-60 cell mitochondria.

Cytochrome-c oxidase is the copper-dependent terminal respiratory complex (complex IV) of the mitochondrial electron transport chain whose activity in a variety of tissues is lowered by copper deficiency. Because inhibition of respiratory complexes increases the production of reactive oxygen species by mitochondria, it is possible that copper deficiency increases oxidative stress in mitochondria as a consequence of suppressed cytochrome-c oxidase activity. In this study, the activities of respiratory complex I + III, assayed as NADH:cytochrome-c reductase, complex II + III, assayed as succinate:cytochrome-c reductase, complex IV, assayed as cytochrome-c oxidase, and fumarase were measured in mitochondria from HL-60 cells that were grown for seven passages in serum-free medium that was either unsupplemented or supplemented with 50 n M CuSO4. Fumarase activity was not affected by copper supplementation, but the complex I + III:fumarase and complex IV:fumarase ratios were reduced 30% and 50%, respectively, in mitochondria from cells grown in the absence of supplemental copper. This indicates that copper deprivation suppressed the electron transfer activity of copper-independent complex I + III as well as copper-dependent complex IV. Manganese superoxide dismutase (MnSOD) content was also increased 49% overall in the cells grown in the absence of supplemental copper. Furthermore, protein carbonyl groups, indicative of oxidative modification, were present in 100-kDa and 90-kDa proteins of mitochondria from copper-deprived cells. These findings indicate that in cells grown under conditions of copper deprivation that suppress cytochrome-c oxidase activity, oxidative stress in mitochondria is increased sufficiently to induce MnSOD, potentiate protein oxidation, and possibly cause the oxidative inactivation of complex I.

Metabolic and hemodynamic effects of moxonidine in the Zucker diabetic fatty rat model of type 2 diabetes.

We studied the effect of moxonidine, an imidazoline ligand, on metabolic and hemodynamic parameters in Zucker diabetic fatty rats, a model of type 2 diabetes. In one group (metabolic group), 8-week-old rats were started on a diet containing either moxonidine (3 or 10 mg x kg(-1) x day(-1)) or vehicle for 4 weeks. Body weight and food intake were monitored daily, plasma insulin and glucose were monitored weekly, and an oral glucose tolerance test (OGTT) was performed at study's end. In another group of rats (hemodynamic group), radio frequency transmitters were implanted 1 week before starting the diet, and mean blood pressure, heart rate, and motor activity were continuously monitored at baseline and for 4 weeks after beginning drug exposure. Moxonidine (10 mg x kg(-1) x day(-1)) significantly decreased elevated glucose levels and prevented the decrease in plasma insulin noted in vehicle-treated or pair-fed groups. Moxonidine also decreased fasting glucose (3 and 10 mg x kg(-1) x day(-1)) and prevented the decrease in fasting insulin (10 mg x kg(-1) x day(-1)) compared with vehicle. Fasting glucose at 10 mg x kg(-1) x day(-1) was equivalent to lean littermates. Both doses significantly increased glucose disposal and the insulin secretory response during the OGTT. Moxonidine lowered daily mean arterial pressure compared with both baseline values and vehicle and decreased daily heart rates. Motor activity was unaffected, except for an increase in the 10 mg x kg(-1) x day(-1) group during low activity periods. Moxonidine did not significantly affect body weight, fluid intake, or urine volume, but the 10 mg x kg(-1) x day(-1) dose reduced urinary protein excretion compared with vehicle-treated animals. These results demonstrate that, in an animal model of type 2 diabetes, the antihypertensive agent moxonidine induces a beneficial effect on abnormal glucose metabolism and renal protein excretion at doses that are effective in lowering arterial blood pressures and heart rate.

Visible-band testbed projector with a replicated diffractive optical element.

Raytheon has designed, fabricated, and tested a diffractive-optical-element-based (DOE-based) testbed projector for direct and indirect visual optical applications. By use of a low-cost replicated DOE surface from Rochester Photonics Corporation for color correction the projector optics bettered the modular transfer function of an equivalent commercial camera lens. The testbed demonstrates that a practical DOE-based optical system is suitable for both visual applications (e.g., head-mounted displays) and visual projection (e.g., tactical sensors). The need for and the proper application of DOE's in visual optical systems, the nature and the performance of the projector optical design, and test results are described.

Scanning electron microscopy and histologic analysis of an apexification "cap": a case report.

A maxillary permanent central incisor with a history of trauma, apexification, and internal thermocatalytic bleaching sustained a horizontal fracture at the cementoenamel junction, which necessitated extraction of the tooth. After removal, the root apex was examined histologically and by scanning electron microscopy. An apexification "cap" with unusual anatomic character and structure was observed.

Storage-phosphor computed radiography versus film radiography in the detection of pathologic periradicular bone loss in cadavers.

OBJECTIVES: The purpose of this study was to compare D-speed film, E-speed film, and the Soredex Digora system with respect to the detection of periradicular pathosis. STUDY DESIGN: Radiographic images of 100 cadaver jaws were made with E-speed film, D-speed film, and the Soredex Digora. Each set of 100 images was interpreted by four observers, with 30 days separating each of three viewing sessions from the next. The presence or absence of pathologic (inflammatory) periradicular bone resorption was determined by histologic examination of the samples. The observer performance was compared with the true histologic findings and evaluated with receiver operating characteristic and corrected receiver operating characteristic analysis. RESULTS: No statistically significant differences were found in diagnostic performance among the three radiographic techniques. In addition, no imaging technique was a good indicator of pathosis as determined by histologic analysis. CONCLUSION: Under the conditions of this study, it was determined that D-speed film, E-speed film, and the Soredex Digora were equivalent diagnostic imaging modalities with regard to the detection of pathologic periradicular bone resorption. No technique predictably indicated inflammatory resorption.

Exploratory studies on azole carboxamides as nucleobase analogs: thermal denaturation studies on oligodeoxyribonucleotide duplexes containing pyrrole-3-carboxamide.

In order to study base pairing properties of the amide group in DNA duplexes, a nucleoside analog, 1-(2'-deoxy-beta-D-ribofuranosyl)pyrrole-3-carboxamide, was synthesized by a new route from the ester, methyl 1-(2'-deoxy-3',5'-di-O-p -toluoyl-beta-D-erythro-pentofuranosyl)pyrrole-3-carboxylate, obtained from the coupling reaction between 1-chloro-2-deoxy-3,5-di-O -toluoyl-d-erythropentofuranose and methyl pyrrole-3-carboxylate by treatment with dimethylaluminum amide. 1-(2'-Deoxy-beta-D-ribofuranosyl)pyrrole-3-carboxamide was incorporated into a series of oligodeoxyribonucleotides by solid-phase phosphoramidite technology. The corresponding oligodeoxyribonucleotides with 3-nitropyrrole in the same position in the sequence were synthesized for UV comparison of helix-coil transitions. The thermal melting studies indicate that pyrrole-3-carboxamide, which could conceptually adopt either a dA-like or a dI-like hydrogen bond conformation, pairs with significantly higher affinity to T than to dC. Pyrrole-3-carboxamide further resembles dA in the relative order of its base pairing preferences (T >dG >dA >dC). Theoretical calculations on the model compound N-methylpyrrole-3-carboxamide using density functional theory show little difference in the preference for a syntau versus anti conformation about the bond from pyrrole C3 to the amide carbonyl. The amide groups in both the minimized antitau and syntau conformations are twisted out of the plane of the pyrrole ring by 6-14 degrees. This twist may be one source of destabilization when the amide group is placed in the helix. Another contribution to the difference in stability between the base pairs of pyrrole-3-carboxamide with T and pyrrole-3-carboxamide with C may be the presence of a hydrogen bond in the former involving an acidic proton (N3-H of T).