Avoiding Dislocation Formation for B, P, and As Implants in Silicon

1991 ◽  
Vol 235 ◽  
Author(s):  
J. R. Liefting ◽  
V. Raineri ◽  
R. J. Schreutelkamp ◽  
J. S. Custer ◽  
F. W. Saris
Keyword(s):  
Higher Doses ◽  
Dislocation Formation

ABSTRACTImplants of B, P, and As in Si lead to dislocation formation after 900°c annealing if a critical amount of implant damage is exceeded. However, it is possible to implant higher doses without forming dislocations if the dose is implanted in several sub-critical steps. Annealing between each step removes the (sub-critical) implant damage and dislocations do not form. Such avoidance of dislocation formation is demonstrated for 80 keV implants of B and MeV implants of B, P, and As.

Pro-oxidant effects of a high α-tocopherol dose on kidney antioxidant biomarkers and histopathological aspects

2017 ◽  
Vol 87 (3-4) ◽  
pp. 179-190
Author(s):  
Amel Kanane ◽  
Fayrouz Rouaki ◽  
Mohamed Brahim Errahmani ◽  
Abdenour Laraba ◽  
Hayet Mesbah ◽  
...  
Keyword(s):  
Sunflower Oil ◽  
Antioxidant Status ◽  
Basal Diet ◽  
Inflammatory Cells ◽  
Significant Rise ◽  
Control Group ◽  
Histopathological Changes ◽  
Group 5 ◽  
Oxidant Effect ◽  
Higher Doses

Abstract. The aim of this study is to evaluate the effect of α-tocopherol supplementation at two doses (600 and 1200 mg × kg–1) on kidney antioxidant status and the histopathological changes in Wistar rats after 12 weeks of exposure at different diets. Forty rats has been divided into 4 groups of 10 rats each, the control group received basal diet with 5 % fresh sunflower oil (FSO), the second group: 5 % oxidized sunflower oil (OSO), the third group: 5 % OSO supplemented with 600 mg × kg–1 α-tocopherol and the fourth group: 5 % OSO supplemented with 1200 mg × kg–1 α-tocopherol. In OSO groups, the results showed highly significant increases of LPO (from 31.3 ± 0.9 to 53.8 ± 1.2 nmol of MDA formed/min/mg protein, p < 0.0001) with a significant decrease (p < = 0.001) of the antioxidant enzymatic activities (CAT, SOD, GPX, GR and G6PDH), body weight (339 ± 9 to 290 ± 3 g) and α-tocopherol levels (13.6 ± 0.6 to 6.5 ± 0.4 μg/mg protein). In OSO groups with 600 mg × kg–1 α-tocopherol, an antioxidant effect was found, reflected by a return of the parameters to values similar to those of the control group. However, higher doses of α-tocopherol (1200 mg × kg–1) induced a depletion of antioxidant status, α-tocopherol levels (6.0 ± 0.3 μg/mg protein, p < 0.001) and a very highly significant rise (p < 0.0001) of LPO content (54.86 ± 0.01 nmol of MDA formed/min/mg protein). The kidney tissues also showed changes in glomerular, severe inflammatory cells infiltration, and formation of novel vessels. So, we can conclude that the oxidative stress is attenuated by a moderate administration of 600 mg × kg–1 α-tocopherol, while a pro-oxidant effect occurs at 1200 mg × kg–1 α-tocopherol.

Involvement of 5-Hydroxytryptamine in Platelet Aggregation In Vivo in Rats and Guinea Pigs

1989 ◽  
Vol 61 (03) ◽  
pp. 463-467 ◽  
Author(s):  
G M Smith
Keyword(s):  
Platelet Count ◽  
Guinea Pigs ◽  
Platelet Adhesion ◽  
Adenosine Diphosphate ◽  
Rate Of Return ◽  
Low Doses ◽  
Dose Dependent ◽  
Higher Doses ◽  
Rat Platelets

SummaryIn this study, 5-hydroxytryptamine (5-HT) caused a dose- dependent fall in the circulating platelet count suggesting that 5-HT receptors are activated in rat platelets to cause platelet adhesion and aggregation. When low doses of adenosine diphosphate (ADP) were simultaneously injected with 5-HT, there was a significant potentiation of the responses to ADR Ketanserin significantly reduced the potentiated responses. When higher doses of ADP were infused with bolus injections of 5-HT there was no potentiation and ketanserin did not reduce these responses. Ketanserin did not inhibit the collagen-induced fall in circulating platelet count, but did significantly increase the rate of return to the basal platelet count compared with control. 5-HT did not cause a fall in platelet count in guinea-pigs

The Interrelationship between Thromboxane Biosynthesis, Aggregation and 5-Hydroxytryptamine Secretion in Human Platelets in Vitro

1980 ◽  
Vol 43 (01) ◽  
pp. 038-040 ◽  
Author(s):  
L C Best ◽  
T K Holland ◽  
P B B Jones ◽  
R G G Russell
Keyword(s):  
Human Platelet ◽  
Human Platelets ◽  
Dense Granule ◽  
Thromboxane B2 ◽  
Essential Requirement ◽  
Direct Mechanism ◽  
Thromboxane Synthetase ◽  
Thromboxane Production ◽  
Higher Doses

SummaryPlatelet aggregation, secretion of 5-hydroxy tryptamine and production of thromboxane B2 were monitored simultaneously in human platelet suspensions in the absence and presence of cyclooxygenase or thromboxane synthetase inhibitors. Aggregation, secretion and thromboxane B2 formation in response to either sodium arachidonate or epinephrine were blocked by aspirin or by 1-N-butyl imidazole suggesting that thromboxane biosynthesis was an essential requirement for platelet activation by these agents. In contrast, thrombin and collagen could apparently induce aggregation and secretion via two pathways: at low doses involving thromboxane production, but at higher doses by a direct mechanism independent of thromboxane biosynthesis. In the case of ADP, inhibition of thromboxane production blocked secretion but had little effect on aggregation, indicating that secretion was probably dependent on thromboxane biosynthesis which probably occurred as a result of aggregation. Thus it appears that although the processes of thromboxane production, release of dense granule constituents and aggregation may often be intimately linked, each process can occur independently of the other, depending upon the stimulus used.

Outcome of Treatment of Deep-Vein Thrombosis with Urokinase: Relationship to Dosage, Duration of Therapy, Age of the Thrombus and Laboratory Changes

1984 ◽  
Vol 51 (02) ◽  
pp. 236-239 ◽  
Author(s):  
A D’Angelo ◽  
P M Mannucci
Keyword(s):  
Degradation Products ◽  
High Rate ◽  
Bleeding Complications ◽  
Vein Thrombosis ◽  
Treatment Regimens ◽  
Duration Of Therapy ◽  
Laboratory Changes ◽  
Deep Vein ◽  
Dose Dependent ◽  
Higher Doses

SummaryForty-one patients with phlebographically proven DVT of the popliteal, femoral or iliac veins were treated with different regimens of urokinase (UK) given by continuous intravenous infusion. The four groups were comparable with respect to localization, extension and estimated age of the thrombi. Another phlebographic picture was taken within 48 hr after the end of UK infusion. Substantial lysis had occurred in 2 of 10 patients treated with 1500 U/kg/h for 2 days, in 4 of 11 treated with 2500/U/kg/h for 3 days, in 2 of 10 treated with 2500 U/kg/h for 7 days and in 4 of 10 treated with 4000 U/kg/h for 4 days. Only thrombi younger than 8 days could be lysed, with 61% (8/13) rate of lysis for thrombi less than 5 days old. Bleeding complications were observed more frequently with the higher doses and longer durations of therapy. The four treatment regimens all induced dose-dependent changes in fibrinogen, fibrin(ogen) degradation products, plasminogen and antiplasmin. Neither pre- nor postinfusion values of these parameters could differentiate patients with lysis from those without lysis. It is concluded that UK can provoke a high rate of thrombolysis of DVT treated early after the appearance of symptoms but that there is no relationship between UK-induced modifications of fibrinolysis and the outcome of therapy.

The Effect of Agents which Modify Platelet Behaviour and of Magnesium Ions on Thrombus Formation In Vivo

1979 ◽  
Vol 42 (02) ◽  
pp. 603-610 ◽  
Author(s):  
J H Adams ◽  
J R A Mitchell
Keyword(s):  
Thrombus Formation ◽  
Cerebral Arteries ◽  
Magnesium Ions ◽  
Body Formation ◽  
Inflammatory Agent ◽  
Platelet Thrombus ◽  
Magnesium Salts ◽  
Higher Doses ◽  
Do So

SummaryThe ability of potential anti-thrombotic agents to modify platelet-thrombus formation in injured cerebral arteries in the rabbit was tested. Low doses of heparin were without effect, while higher doses produced variable suppression of white body formation but at the expense of bleeding. Aspirin did not inhibit white body formation but another non-steroid anti-inflammatory agent, flurbiprofen was able to do so, as was the anti-gout agent, sulphinpyrazone. Magnesium salts both topically and parenterally, suppressed thrombus formation and increased the concentration of ADP which was required to initiate thrombus production at minor injury sites.

Neutralization of a Low Molecular Weight Heparin (LHN-1) and Conventional Heparin by Protamine Sulfate in Rats

1986 ◽  
Vol 56 (03) ◽  
pp. 318-322 ◽  
Author(s):  
V Diness ◽  
P B Østergaard
Keyword(s):  
Molecular Weight ◽  
Low Molecular Weight Heparin ◽  
Thrombus Formation ◽  
Experimental Models ◽  
Protamine Sulfate ◽  
Low Molecular Weight ◽  
Antithrombotic Effect ◽  
Higher Doses

SummaryThe neutralization of a low molecular weight heparin (LHN-1) and conventional heparin (CH) by protamine sulfate has been studied in vitro and in vivo. In vitro, the APTT activity of CH was completely neutralized in parallel with the anti-Xa activity. The APTT activity of LHN-1 was almost completely neutralized in a way similar to the APTT activity of CH, whereas the anti-Xa activity of LHN-1 was only partially neutralized.In vivo, CH 3 mg/kg and LHN-1 7.2 mg/kg was given intravenously in rats. The APTT and anti-Xa activities, after neutralization by protamine sulfate in vivo, were similar to the results in vitro. In CH treated rats no haemorrhagic effect in the rat tail bleeding test and no antithrombotic effect in the rat stasis model was found at a protamine sulfate to heparin ratio of about 1, which neutralized APTT and anti-Xa activities. In LHN-1 treated rats the haemorrhagic effect was neutralized when APTT was close to normal whereas higher doses of protamine sulfate were required for neutralization of the antithrombotic effect. This probably reflects the fact that in most experimental models higher doses of heparin are needed to induce bleeding than to prevent thrombus formation. Our results demonstrate that even if complete neutralization of APTT and anti-Xa activities were not seen in LHN-1 treated rats, the in vivo effects of LHN-1 could be neutralized as efficiently as those of conventional heparin. The large fall in blood pressure caused by high doses of protamine sulfate alone was prevented by the prior injection of LHN-1.

INTERACTIONS OF OESTRONE AND TESTOSTERONE ON MAMMARY GLANDS OF MALE RABBITS

1961 ◽  
Vol 36 (1) ◽  
pp. 141-156 ◽  
Author(s):  
B. Bengtsson ◽  
A. Norgren
Keyword(s):  
Mammary Gland ◽  
Testosterone Propionate ◽  
Mammary Glands ◽  
List Type ◽  
Stunted Growth ◽  
Abnormal Growth ◽  
Growth Reaction ◽  
Extensive Growth ◽  
Higher Doses

ABSTRACT The effect of testosterone and oestrone on the mammary glands of castrated male rabbits was studied. Testosterone propionate was used in daily doses from 0.5 to 80 mg. The doses of oestrone ranged from 0.05 to 25 μg per day. Mammary glands were examined after 14, 28 or 56 days of injections. 1) Testosterone in doses below 20 mg failed to affect the mammary glands. With 40 or 80 mg a distinct, though abnormal growth reaction was consistently obtained. 2) Oestrone in doses lower than 0.5 μg did not stimulate mammary growth. With 0.5 μg and higher doses extensive growth of the mammary glands occurred. Stunted growth and secretion were found in the mammary glands of rabbits injected with 12.5 or 25 μg oestrone. 3) Testosterone in doses of 1 or 5 to 10 mg depressed or abolished the response of the mammary glands to 0.5 μg oestrone. When testosterone, in doses ineffective when given alone, was added to at least 3.125 μg oestrone, the mammary glands developed alveoli. The abnormalities produced by the highest doses of oestrone studied were exaggerated by the addition of testosterone. 4) The observations indicate a complicated interplay between the actions of testosterone and oestrone on the mammary gland of the rabbit. The interactions between testosterone and oestrone are presumably different from those observed between progesterone and oestrone.

FEEDBACK CONTROL OF FSH IN THE MALE: ROLE OF OESTROGEN

1973 ◽  
Vol 74 (3) ◽  
pp. 449-460 ◽  
Author(s):  
Patrick C. Walsh ◽  
Ronald S. Swerdloff ◽  
William D. Odell
Keyword(s):  
Luteinizing Hormone ◽  
Follicle Stimulating Hormone ◽  
Oestrogen Therapy ◽  
Serum Concentrations ◽  
Elderly Men ◽  
Normal Range ◽  
Oestrogen Treatment ◽  
Serum Lh ◽  
Higher Doses

ABSTRACT Serum follicle stimulating hormone (FSH) and luteinizing hormone (LH) were measured by radioimmunoassay in a group of elderly men following castration and oestrogen therapy. Prior to orchiectomy, mean serum concentrations of LH and FSH were within the normal range. Two days following castration, serum LH concentrations increased in all eight patients; higher levels of LH were subsequently measured in all but one patient after periods of time ranging from 49 to 210 days. Serum FSH levels, measured in three patients following castration, increased in a pattern parallel to LH changes. Ethinyl oestradiol (EOe) in doses ranging from 5 to 300 μg/day was administered to ten men who had been castrated 3 to 72 months earlier. Oestrogen treatment suppressed both LH and FSH in a parellel manner in nine of ten patients. LH was first suppressed to intact levels in one of eight patients treated with 20 μg/day of EOe, in two of six patients treated with 50 μg/day, and in one patient by 80 μg/day. FSH was not suppressed to precastration levels until 50 μg/day of EOe was administered; this dose suppressed three of six patients. Higher doses of EOe (150–300 μg/day) suppressed both LH and FSH to levels below the sensitivity of the assay. These data fail to demonstrate any differential effect of oestrogen on LH and FSH release.

EFFECT OF OESTRONE-PELLET IMPLANTATION ON PLASMA LEVELS OF PROLACTIN

1970 ◽  
Vol 64 (2) ◽  
pp. 265-272 ◽  
Author(s):  
A. A. van der Gugten ◽  
M. Sala ◽  
H. G. Kwa
Keyword(s):  
Plasma Levels ◽  
Male Rats ◽  
Mean Values ◽  
The Mean ◽  
Dose Levels ◽  
Higher Doses ◽  
Primary Break

ABSTRACT Eight female and eight male rats were castrated at the age of 8 to 10 weeks. Four spayed and four orchidectomized rats received one oestrone/cholesterol pellet (200 μg oestrone) on the day of operation (day 0), a second pellet on day 11 and a third on day 23. The remaining animals received four oestrone/cholesterol pellets at these times. The fluctuations in the prolactin levels in the circulation induced by the oestrogen challenges in these animals were followed during 31 days by radioimmunoassays performed on days 3, 7, 9, 14, 15, 17, 23, 24, 25, 28 and 31. The results suggested that the homoeostatic mechanism regulating plasma levels of prolactin was capable of withstanding the three time-spaced oestrogen challenges only in the spayed animals receiving the lower doses of oestrogen, since it allowed the mean values of the prolactin levels to remain fairly constant during the first 4 weeks. The levels in this group rose to much higher levels only on day 31. The higher doses of oestrone in the spayed rats and both dose levels of oestrone in the orchidectomized animals apparently resulted in a primary break-down of the homoeostatic mechanism, since the prolactin levels in the animals of these groups rose to much higher levels either on day 7 or on day 9. This was followed by a period during which the prolactin levels appeared to be more or less under control, until a second and probably definitive failure of the homoeostatic mechanism allowed the mean levels to rise sharply again.

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