The Effect of Glucocorticoids on the Expression of L-Selectin on Polymorphonuclear Leukocyte

Blood ◽  
1999 ◽  
Vol 93 (8) ◽  
pp. 2730-2737 ◽  
Author(s):  
Motohito Nakagawa ◽  
Gregory P. Bondy ◽  
Dan Waisman ◽  
Diane Minshall ◽  
James C. Hogg ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Single Dose ◽  
New Zealand ◽  
Polymorphonuclear Leukocyte ◽  
Glucocorticoid Treatment ◽  
Thymidine Analogue ◽  
New Zealand White Rabbits ◽  
Inflammatory Stimuli ◽  
Baseline Levels ◽  
Glucocorticoid Effect

Abstract When active bone marrow release is induced by inflammatory stimuli, it is associated with an increase in L-selectin expression on circulating polymorphonuclear leukocyte (PMN). This contrasts sharply with glucocorticoid-induced granulocytosis that is associated with decreased L-selectin expression on PMN. The present study was designed to determine if the reduced L-selectin expression observed after glucocorticoid treatment is the result of suppression of L-selectin synthesis in the bone marrow. New Zealand white rabbits treated with dexamethasone (2.0 mg/kg, a single dose intravenously) were shown to have decreased L-selectin expression on circulating PMN 12 to 24 hours after treatment (P < .01) with a return to baseline levels by 48 hours. When dexamethasone was administered 48 hours after the bone marrow PMN were pulse labeled with the thymidine analogue, 5′-bromo-2′-deoxyuridine (BrdU), L-selectin expression on BrdU-labeled PMN released from the bone marrow was decreased (P< .01). Dexamethasone decreased L-selectin expression on segmented PMN in the bone marrow (P < .05) but not on PMN already in the circulation. We conclude that glucocorticoids decrease L-selectin expression on circulating PMN by downregulating L-selectin expression in the maturation pool of bone marrow and speculate that this is an important glucocorticoid effect that influences the recruitment of PMN into inflammatory sites.

The Effect of Glucocorticoids on the Expression of L-Selectin on Polymorphonuclear Leukocyte

Blood ◽  
1999 ◽  
Vol 93 (8) ◽  
pp. 2730-2737 ◽  
Author(s):  
Motohito Nakagawa ◽  
Gregory P. Bondy ◽  
Dan Waisman ◽  
Diane Minshall ◽  
James C. Hogg ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Single Dose ◽  
New Zealand ◽  
Polymorphonuclear Leukocyte ◽  
Glucocorticoid Treatment ◽  
Thymidine Analogue ◽  
New Zealand White Rabbits ◽  
Inflammatory Stimuli ◽  
Baseline Levels ◽  
Glucocorticoid Effect

When active bone marrow release is induced by inflammatory stimuli, it is associated with an increase in L-selectin expression on circulating polymorphonuclear leukocyte (PMN). This contrasts sharply with glucocorticoid-induced granulocytosis that is associated with decreased L-selectin expression on PMN. The present study was designed to determine if the reduced L-selectin expression observed after glucocorticoid treatment is the result of suppression of L-selectin synthesis in the bone marrow. New Zealand white rabbits treated with dexamethasone (2.0 mg/kg, a single dose intravenously) were shown to have decreased L-selectin expression on circulating PMN 12 to 24 hours after treatment (P < .01) with a return to baseline levels by 48 hours. When dexamethasone was administered 48 hours after the bone marrow PMN were pulse labeled with the thymidine analogue, 5′-bromo-2′-deoxyuridine (BrdU), L-selectin expression on BrdU-labeled PMN released from the bone marrow was decreased (P< .01). Dexamethasone decreased L-selectin expression on segmented PMN in the bone marrow (P < .05) but not on PMN already in the circulation. We conclude that glucocorticoids decrease L-selectin expression on circulating PMN by downregulating L-selectin expression in the maturation pool of bone marrow and speculate that this is an important glucocorticoid effect that influences the recruitment of PMN into inflammatory sites.

Polymorphonuclear leukocyte cytoplasts mediate acute lung injury

1988 ◽  
Vol 65 (2) ◽  
pp. 706-713 ◽  
Author(s):  
V. B. Antony ◽  
C. L. Owen ◽  
D. English
Keyword(s):  
Acute Lung Injury ◽  
New Zealand ◽  
Lung Injury ◽  
Polymorphonuclear Leukocyte ◽  
Lung Lavage ◽  
Lung Weight ◽  
Endothelial Monolayers ◽  
New Zealand White Rabbits

Injection of phorbol 12-myristate 13-acetate (PMA) into polymorphonuclear leukocyte (PMN)-depleted, PMN cytoplast-repleted New Zealand White rabbits caused the development of acute lung injury in vivo. PMN cytoplasts are nucleus- and granule-free vesicles of cytoplasm capable of releasing toxic O2 radicals but incapable of releasing granule enzymes. PMN cytoplasts when activated by PMA reduced 66 +/- 12.7 nmol of cytochrome c compared with 2.6 +/- 0.7 nmol in their resting state and did not release a significant quantity of granule enzymes (P greater than 0.05). Injection of PMA into New Zealand White rabbits caused a significant decrease (P less than 0.05) in the number of circulating cytoplasts. Increases in lung weight-to-body weight ratios in PMA-treated rabbits (9.8 +/- 0.5 X 10(-3] compared with saline-treated rabbits (5.3 +/- 0.2 X 10(-3] were also noted. Levels of angiotensin-converting enzyme in lung lavage as well as the change in alveolar-arterial O2 ratio correlated with the numbers of cytoplasts in lung lavage (P = 0.001, r = 0.84 and P = 0.0166, r = 0.73, respectively). Albumin in lung lavage increased to 1,700 +/- 186 mg/ml in PMA-treated rabbits from 60 +/- 30 mg/ml in saline-treated rabbits. These changes were attenuated by pretreatment of rabbits with dimethylthiourea (DMTU). In vitro, cytoplasts were able to mediate increases in endothelial monolayer permeability. This was evidenced by increases in fractional transit of albumin across endothelial monolayers when treated with PMA-activated cytoplasts (0.08 +/- 0.01 to 0.28 +/- 0.02).(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals Toxicological Assessment of a Standardized Boswellia serrata Gum Resin Extract

2019 ◽  
Vol 38 (5) ◽  
pp. 423-435 ◽  
Author(s):  
Venkata Krishnaraju Alluri ◽  
Sundararaju Dodda ◽  
Eswar Kumar Kilari ◽  
Trimurtulu Golakoti ◽  
Krishanu Sengupta
Keyword(s):  
Bone Marrow ◽  
New Zealand ◽  
Wistar Rats ◽  
Clinical Chemistry ◽  
Micronucleus Assay ◽  
Female Rats ◽  
Mouse Bone Marrow ◽  
Boswellia Serrata ◽  
Male And Female Rats ◽  
New Zealand White Rabbits

The acidic and non-acidic fractions of Boswellia serrata gum resin extracts were combined to prepare a unique product, LI13019F1 (Serratrin). The present series of studies evaluated LI13019F1 for acute and subchronic (28-day) toxicity in Wistar rats and acute dermal and eye irritation in New Zealand white rabbits. The mutagenicity and clastogenicity of LI13019F1 were evaluated in bacteria and mouse bone marrow erythrocytes, respectively. All studies were performed following the Organization for Economic Co-operation and Development guidelines. Acute oral and acute dermal toxicity studies did not show mortality or signs of toxicity in Wistar rats at a limit dose of 2,000 mg/kg LI13019F1. LI13019F1 did not cause irritation to the skin or the eyes of New Zealand white rabbits. In a repeated dose 28-day oral toxicity study, LI13019F1-treated Wistar rats did not show dose-related signs of toxicity on their body weights, organ weights, and on the hematology and clinical chemistry parameters. The estimated no observed adverse effect level for LI13019F1 was 1,000 mg/kg/day in both male and female rats. The bacterial reverse mutation test and a micronucleus assay in mouse bone marrow erythrocytes revealed that LI13019F1 was neither mutagenic nor clastogenic. Together, the present observations demonstrate a broad-spectrum safety of LI13019F1.

scholarly journals Steroid metabolism in the rabbit. Biliary and urinary excretion of metabolites of [4-14C]progesterone

1965 ◽  
Vol 97 (1) ◽  
pp. 89-94 ◽  
Author(s):  
W Taylor ◽  
T Scratcherd
Keyword(s):  
Single Dose ◽  
New Zealand ◽  
Urinary Excretion ◽  
Alkaline Solution ◽  
Single Injection ◽  
Steroid Metabolism ◽  
Apparent Difference ◽  
Total Recovery ◽  
Male And Female ◽  
New Zealand White Rabbits

1. [4-(14)C]Progesterone was administered intravenously to anaesthetized male and female New Zealand White rabbits as a single injection or as a 45-60min. infusion. 2. After a single dose about 60% of the radioactivity was recovered in 6hr., and twice as much radioactivity was present in bile as in urine. After infusion total recovery of radioactivity was only about 40% in 6hr., but the relative proportions of metabolites in bile and urine were about the same as after a single dose. 3. Bile and urine samples were hydrolysed successively by beta-glucuronidase, cold acid and hot acid. 4. In bile the major proportion of metabolites appeared in the glucuronide fraction; in urine beta-glucuronidase hydrolysis yielded the greatest amounts of ether-extractable radioactivity, but the greatest proportion of radioactivity could not be extracted by ether from an alkaline solution of the hydrolysed urine. 5. There was no apparent difference in the quantity or distribution of metabolites excreted by male and female animals.

A trial of doramectin injection and ivermectin spot-on for treatment of rabbits artificially infested with the ear mite “Psoroptes cuniculi”

2017 ◽  
Vol 20 (3) ◽  
pp. 521-525 ◽  
Author(s):  
N.M. Elhawary ◽  
Sh. S.G.H. Sorour ◽  
M.A. El-Abasy ◽  
E.K. Bazh ◽  
K. Sultan
Keyword(s):  
Single Dose ◽  
New Zealand ◽  
Great Improvement ◽  
Skin Disease ◽  
Positive Control ◽  
Control Group ◽  
Therapeutic Trial ◽  
Psoroptes Cuniculi ◽  
New Zealand White Rabbits ◽  
The World

Abstract The ear mite “Psoroptes cuniculi” is the main cause of ear mange, a highly contagious parasitic skin disease in rabbits all over the world. In the current work, a preliminary therapeutic trial to study the effect of the broad use acaricides doramectin and ivermectin on P. cuniculi was performed on artificially infested rabbits. Twenty five adult New Zealand white rabbits were used in this study. The rabbits were assigned randomly into five groups/ 5 rabbits in each group. Each rabbit was experimentally infested with 100 mites/ ear. The first group was designated the positive control group and was not treated. The second and third groups were treated with doramectin 200 and 400 μg/kg bw, respectively. Groups 4 and 5 were treated by dressing with ivermectin in one dose and 2 doses with a 1 week interval. After the therapy, all rabbits were examined microscopically on the 7th, 14th, and 28th day post treatment and the number of live mites (larvae, nymphs, and adults) on each rabbit was counted at the end of the experiment (28th day). The results showed that the rabbits treated subcutaneously with doramectin at a single dose of 200 μg /kg bw showed a very low effect, although there was significant improvement when the dose was doubled to 400 μg /kg bw, with the number of mites counted decreasing significantly. Rabbits treated topically with ivermectin spot-on, a single dose or 2 doses, showed great improvement of the lesion: the number of mites was reduced to zero. In conclusion, this work showed that ivermectin spot-on applied locally on infested ears proves to be more effective against P. cuniculi than doramectin injected subcutaneously. Further trials on ear mange therapeutics in rabbits are to be encouraged.

Use of Platelet-Rich Plasma Immediately After an Injury Did Not Improve Ligament Healing, and Increasing Platelet Concentrations Was Detrimental in an In Vivo Animal Model

2017 ◽  
Vol 46 (3) ◽  
pp. 702-712 ◽  
Author(s):  
Robert F. LaPrade ◽  
Laurie R. Goodrich ◽  
Jennifer Phillips ◽  
Grant J. Dornan ◽  
Travis Lee Turnbull ◽  
...  
Keyword(s):  
Single Dose ◽  
New Zealand ◽  
Platelet Rich Plasma ◽  
Maximum Load ◽  
Ligament Injuries ◽  
Sham Surgery ◽  
New Zealand White Rabbits ◽  
Histological Characteristics ◽  
Ligament Healing

Background: Limited information in basic science and clinical trials exists to determine if ligament healing may be accelerated with the use of biological adjuvants, such as platelet-rich plasma (PRP). However, there has been widespread acceptance of PRP for use in clinical practice, despite an inadequate understanding of its biological mechanism of action. Purpose: To determine whether a single dose of PRP could accelerate ligament healing and correspondingly improve histological characteristics and biomechanical properties when injected immediately postoperatively into the injured medial collateral ligament (MCL) of New Zealand White rabbits. Study Design: Controlled laboratory study. Methods: Eighty skeletally mature New Zealand White rabbits (160 knees) were used. The MCL was torn midbody to simulate a grade 3 tear. After an acute injury of the MCL, the administration of autologous PRP at 3 different platelet concentrations (0 million/uL, platelet-poor plasma [PPP]; 0.6 million/uL, 2 times the baseline [2× PRP]; and 1.2 million/uL, 4 times the baseline [4× PRP]) was performed and compared with a saline injection control in the contralateral knee. Histological analysis and a biomechanical endpoint characterization were utilized to assess ligamentous healing and compare it to a sham surgery group. Results: The PPP ( P = .001) and 4× PRP ( P = .002) groups had a significantly lower collagen subscore than the sham surgery group. No other differences were observed among the treatment groups, including the vascularity subscore and overall ligament tissue maturity index score. Compared with saline-injected contralateral knees, the maximum load for PPP and 2× PRP was not significantly different ( P = .788 and .325, respectively). The maximum load and stiffness for knees treated with 4× PRP were significantly less than for the saline-treated contralateral knees ( P = .006 and .001, respectively). Conclusion: One single dose of PPP or 2× PRP at the time of injury did not improve ligament healing. In addition, 4× PRP negatively affected ligament strength and histological characteristics at 6 weeks after the injury. Clinical Relevance: The current practice of treating knee ligament injuries with PRP may not improve healing at low doses of PRP. The decreased mechanical properties and histological appearance of the torn MCL suggest that high doses of PRP decrease the quality of repair tissue. Further in vivo studies are necessary to determine the dosing and timing of PRP administration after a ligament injury before the widespread use of PRP to treat ligament injuries is recommended.

A Cytochemical Study of Glucose-6-Phosphatase (G-6-PASE) in Cells Participating in Atherogenesis of Rabbit Aorta

1975 ◽  
Vol 33 ◽  
pp. 460-461
Author(s):  
Sidney D. Kobernick ◽  
Edna A. Elfont ◽  
Neddra L. Brooks
Keyword(s):  
Lipid Metabolism ◽  
New Zealand ◽  
Aortic Wall ◽  
Rabbit Aorta ◽  
Plaque Formation ◽  
Metabolic Changes ◽  
Atherosclerotic Plaques ◽  
Cytochemical Study ◽  
Cellular Alteration ◽  
New Zealand White Rabbits

This cytochemical study was designed to investigate early metabolic changes in the aortic wall that might lead to or accompany development of atherosclerotic plaques in rabbits. The hypothesis that the primary cellular alteration leading to plaque formation might be due to changes in either carbohydrate or lipid metabolism led to histochemical studies that showed elevation of G-6-Pase in atherosclerotic plaques of rabbit aorta. This observation initiated the present investigation to determine how early in plaque formation and in which cells this change could be observed.Male New Zealand white rabbits of approximately 2000 kg consumed normal diets or diets containing 0.25 or 1.0 gm of cholesterol per day for 10, 50 and 90 days. Aortas were injected jin situ with glutaraldehyde fixative and dissected out. The plaques were identified, isolated, minced and fixed for not more than 10 minutes. Incubation and postfixation proceeded as described by Leskes and co-workers.

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