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1.
Two dosages of Smokeless Tobacco (ST) extract were given to gravid Sprague-Dawley rats by oral gavage on gestational days (GD) 6-20. The low dosage contained ST extract equivalent to 1.33 mg/kg nicotine (STD-1), and the high dosage contained ST extract equivalent to 4.0 mg/kg nicotine (STD-2). Dams were dosed three times daily at 8 a.m., 11 a.m., and 2 p.m., thus providing total daily nicotine equivalent dosages of 4 mg/kg/day and 12 mg/kg/day. Controls received equivalent amounts of distilled water by gavage. Dams were allowed to deliver and all experimental pups were fostered to control mothers. On postnatal day 1 (PND 1) litters were culled to 4 +/- 1 females and 4 +/- 1 males. Weights, physical landmark development, and behavioral performance of pups were monitored during pre- and post-weaning periods. Behavioral tests included: surface righting, negative geotaxis, swimming development, open-field activity, active avoidance in shuttle box, and Cincinnati swimming maze. Our results show that the STD-2 dose resulted in reduced maternal weight gain. Offspring weights were reduced in a dose-related manner, with the most consistent weight deficits seen in the STD-2 group until PND29. Consistent STD-1 weight deficits were seen up to PND 8. The incidence of deaths was increased in the STD-2 dosage group. No significant treatment-related differences were observed in development of physical landmarks. Male STD-2 pups righted faster than controls, and significant differences were noted in swimming development with the STD-1 group of pups performing less effectively than controls. Activity levels, assessed during both pre- and post-weaning periods were not affected. No treatment-related differences were seen in the active avoidance shuttle box or Cincinnati swimming maze tests, which assessed learning. Female brain weights were reduced in the STD-1 treatment group. 相似文献
2.
Julian Daniels Dan G. Blumberg Leonid D. Vulfson Alex L. Kotlyar Valentin Freiliker Gefen Ronen Jiftah Ben-Asher 《Remote sensing of environment》2003,86(2):243-256
We report remote detections of physically buried specularly reflecting objects using microwave radar at two sites: Ashalim and Tseelim in the northern region of the Negev Desert, Israel. These detections provide confirmation that microwave subsurface remote sensing is a genuine phenomenon. At Ashalim, a scatterometer operating in the P-band (441 MHz, 68 cm) was mounted on a cherry picker truck at a height of 8 m and used to detect two triangular aluminum mesh reflectors (forming a 1-m square area reflector) buried down to a depth of 8 cm in dry sand. At Tseelim, the same scatterometer was mounted on an airplane flying at an altitude of 70 m and used to detect 1-m square aluminum reflectors (each one submerged at a different location along the airplane flight path) buried down to a depth of 20 cm. The experimental results compare favorably with a theoretical model that incorporates radar absorption effects arising in the sandy subsurface layer and radar interference effects arising from phase differences between reflections from the surface and buried reflector. The theoretical modeling also predicts the detection of a subsurface reflector down to a depth of about 4.4 m. This experiment and the associated modeling approach is the first of a series of planned experiments, which we outline for the detection and the theoretical evaluation of buried reflectors using remote microwave and VHF radar. We identify potential subject areas for environmental research. 相似文献
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Andreas Zehnsdorf Norman Stock Juliane Richter Michael Blumberg Roland A. Müller 《化学,工程师,技术》2016,88(8):1138-1144
There is increasing interest worldwide in the decentralized treatment of gray water. Since ground‐level areas are generally costly, gray‐water treatment can also be carried out using helophyte mats on the roofs of buildings as an alternative. Alongside the water treatment itself, this process also has a positive effect on the indoor climate in the building. In a test carried out under realistic conditions, it was shown that a helophyte mat with a root‐layer depth of 0.1 m and with hydraulic loads per unit up to 15 L m?2d?1 is suitable for treating typical gray water from a residential building. 相似文献
5.
Simin Nikbin Meydani Alice C. Shapiro Mohsen Meydani John B. Macauley Jeffrey B. Blumberg 《Lipids》1987,22(5):345-350
The effect of age and dietary fat type on tocopherol status was investigated using young and old C57BL/6Nia mice fed semipurified
diets containing 5% (by weight) fish, corn or coconut oils and supplemented with 30, 100 or 500 ppm dl-α-tocopheryl acetate
for 6 wk. Tocopherol levels in the diets, plasma, liver, kidney and lung were measured by high performance liquid chromatography
following appropriate extractions. The results indicate that mice fed fish oil maintain lower plasma and tissue tocopherol
concentrations than those fed corn and cononut oils (fish<corn oil<coconut oil). The difference was not due to a loss of tocopherol
prior to consumption, but rather appeared to occur during the absorption process. Old mice had lower plasma and liver tocopherol
concentrations than young mice. Old mice fed fish oil, however, maintained plasma tocopherol levels better than young mice
fed fish oil, presumably due to their larger tocopherol pool. No age effect was detected on kidney and lung tocopherol levels.
It is concluded that tocopherol status is affected by age and dietary fat type, especially fish oil. 相似文献
6.
Dr. Jessica S. Kelsey Dr. Tamas Geczy Nancy E. Lewin Dr. Noemi Kedei Colin S. Hill Julia S. Selezneva Christopher J. Valle Wonhee Woo Dr. Inna Gorshkova Dr. Peter M. Blumberg 《Chembiochem : a European journal of chemical biology》2014,15(8):1131-1144
The C1 domain, which represents the recognition motif on protein kinase C for the lipophilic second messenger diacylglycerol and its ultrapotent analogues, the phorbol esters, has emerged as a promising therapeutic target for cancer and other indications. Potential target selectivity is markedly enhanced both because binding reflects ternary complex formation between the ligand, C1 domain, and phospholipid, and because binding drives membrane insertion of the C1 domain, permitting aspects of the C1 domain surface outside the binding site, per se, to influence binding energetics. Here, focusing on charged residues identified in atypical C1 domains which contribute to their loss of ligand binding activity, we showed that increasing charge along the rim of the binding cleft of the protein kinase C δ C1 b domain raises the requirement for anionic phospholipids. Correspondingly, it shifts the selectivity of C1 domain translocation to the plasma membrane, which is more negatively charged than internal membranes. This change in localization is most pronounced in the case of more hydrophilic ligands, which provide weaker membrane stabilization than do the more hydrophobic ligands and thus contributes an element to the structure–activity relations for C1 domain ligands. Coexpressing pairs of C1‐containing constructs with differing charges each expressing a distinct fluorescent tag provided a powerful tool to demonstrate the effect of increasing charge in the C1 domain. 相似文献
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E Straumann O Bertel B Meyer P Weiss M Misteli A Blumberg H Jenzer 《Canadian Metallurgical Quarterly》1998,21(9):672-678
BACKGROUND: Patients with end-stage renal disease on regular hemodialysis have an increased prevalence of left ventricular (LV) hypertrophy that is associated with morbidity and mortality. Asymmetric septal hypertrophy and impairment of LV outflow can occur in these patients and may contribute to adverse outcomes. More insight into the prevalence, extent, geometry, and promoting factors of LV hypertrophy is important. METHODS: An unselected group of 62 patients (31 women), aged 55 +/- 14 years, on maintenance hemodialysis was investigated by Doppler echocardiography. Eight patients with valvular heart disease were excluded from further analysis. We assessed prevalence of LV hypertrophy and asymmetric septal hypertrophy, as well as parameters of LV geometry and LV filling and outflow dynamics. RESULTS: Prevalence of LV hypertrophy was 65%. Patients were analyzed according to LV mass and geometry. Mean LV mass index was normal (105 +/- 17 g/m2) in Group 1 without LV hypertrophy (n = 19); it was markedly elevated in Group 2 (symmetric hypertrophy, n = 22) and Group 3 (asymmetric hypertrophy with systolic anterior movement of mitral valve, n = 7), and highest (191 +/- 54 g/m2) in Group 4 (asymmetric hypertrophy without systolic anterior movement of mitral valve, n = 6, p < 0.001). Age, body mass index, and duration of hypertension were associated with LV hypertrophy and asymmetric septal hypertrophy (p = 0.01). Group 3 with systolic anterior motion of mitral valve had the smallest end-diastolic LV diameters (p = 0.02); increased heart rates, and increased ejection velocities in the LV outflow tract (p = 0.03, and p = 0.005, respectively, vs. Groups 1, 2, and 4) which pointed to an impairment of LV outflow. CONCLUSIONS: Symmetric LV hypertrophy and asymmetric septal hypertrophy are frequent in patients on maintenance hemodialysis. Predictors for LV hypertrophy were age and body mass index, and, particularly for asymmetric septal hypertrophy, age and hypertension duration. Volume withdrawal during hemodialysis may lead to symptomatic hypotension due to dynamic obstruction in some patients with severe asymmetric septal hypertrophy. 相似文献
9.
The central role of protein kinase C (PK-C) in cellular signal transduction has established it as an important therapeutic target for cancer and other diseases. We have developed a series of 4,4-disubstituted-gamma-butyrolactones, which contain a constrained glycerol backbone (DAG-lactones) and behave as potent and selective activating ligands of PK-C with affinities that approach those of the structurally complex natural product agonists, such as the phorbol esters. This Account traces the design and construction of these molecules. Initially, we examined the consequences of reducing the entropic penalty associated with the transformation of a DAG into a DAG-lactone. Then, using molecular modeling to extend insights arising from the newly solved crystal structure of a C1 domain complexed with phorbol ester, we incorporated amino acid-specific branched hydrophobic chains to provide a new generation of DAG-lactones that have the capacity to bind to PK-C with low nanomolar affinity. Depending on the specific pattern of hydrophobic substitution, some DAG-lactones are able to induce selective translocation of individual PK-C isozymes to different cellular compartments, and since the specific nature of these hydrophobic interactions influences biological outcome, some of these compounds exhibit cell-specific antitumor activity. The ability to direct specific PK-C isozyme translocation with sets of structurally simple, yet highly potent molecules provides a powerful tool for engineering a plethora of molecules with novel biological functions. 相似文献
10.