The clinical, cerebrospinal fluid, and histopathologic effects of epidural ketorolac in dogs.

OBJECTIVE: To evaluate the clinical, cerebrospinal fluid (CSF), and histopathologic effects of epidural ketorolac. STUDY DESIGN: Blinded, randomized, placebo controlled study. ANIMALS: Twenty-two adult mixed breed dogs with 16 treatment and 6 control dogs, weighing 14.4 to 29.8 kg. METHODS: Dogs were anesthetized and epidural catheters were placed at the lumbosacral space. Catheter placement was evaluated fluoroscopically. Ketorolac (0.4 mg/kg) or placebo (5% ethanol) was administered epidurally over a 52-hour period, with 5 injections given at 12-hour intervals. At 1, 2, 4, or 8 hours after the first and last injection of ketorolac, dogs were anesthetized and CSF was obtained. Control dogs had CSF sampled 1 hour after the first and last ethanol injection. Neurologic function and pain responses were evaluated before and during the study. Selected dogs were then killed and necropsies performed. RESULTS: None of the dogs exhibited any clinical or neurologic abnormalities during the study. No statistical difference was noted in pain response or CSF analysis between treatment and control dogs. Gross necropsy revealed gastrointestinal ulceration of varying degrees in all treatment dogs. Histopathologic analysis of the spinal cord and meninges revealed minimal focal leptomeningeal phlebitis in 2 of 8 treatment dogs and minor subdural inflammation in 1 control dog. No changes to the neural structures were noted in any dogs. CONCLUSIONS: Epidural administration of ketorolac did not cause clinical signs, alteration in CSF values, or pathologic changes to the spinal cord when used for short duration. Gastrointestinal ulceration was common when ketorolac was administered epidurally at 0.4 mg/kg every 12 hours for 5 treatments. CLINICAL RELEVANCE: This study documented the neurologic safety of epidural ketorolac in dogs before an efficacy trial can be performed. Gastrointestinal ulceration may limit use to short duration or a single injection.

The effect of long-term treatment with granulocyte colony-stimulating factor on hematopoiesis in HIV-infected individuals.

This randomized, placebo-controlled trial examine the long-term effect of granulocyte colony-stimulating factor (G-CSF) on absolute numbers of CD34+ progenitor cells and progenitor cell function in human immunodeficiency virus (HIV)-infected patients. G-CSF (300 microg filgrastim) or placebo was given three times weekly for 12 weeks to 30 HIV-infected patients that had been treated with HAART for at least 24 weeks and not yet achieved CD4 counts above 350 CD4+ cells/microl. Blood samples were collected at weeks 0, 2, 4, 8, and 12, and again 12 weeks after termination of the G-CSF treatment. Significant increase in absolute numbers of circulating CD34+ cells was detected in the treatment group (P = 0.006). The function of progenitor cells was examined in vitro using a colony-forming unit (CFU) assay, and increase in the number of CFU/ml was detected (P = 0.005). In order to estimate the effect of G-CSF on in vivo function of progenitors the white-blood count was determined. Significant increase in white-blood count was found (P < 0.001), while hemoglobin and platelet count decreased (P = 0.001 and P = 0.013, respectively). Significant increase in the CD4 count occurred, but correlation between the numbers of progenitors and the CD4 count was not found. These data suggest that G-CSF mainly increases the number and differentiation of myeloid progenitors.

A dose-ranging study of pegylated interferon alfa-2b and ribavirin in chronic hepatitis C. The Hepatitis C Intervention Therapy Group.

The objectives of this study were to assess the safety, pharmacokinetics, and efficacy of pegylated interferon alfa-2b (PEG-Intron) plus ribavirin in patients with chronic hepatitis C. A total of 72 patients (35 men/37 women, age range 20-68 years) with clinically compensated chronic hepatitis C virus (HCV) were enrolled into this open-label, randomized, active controlled study. Patients received either PEG-Intron 0.35, 0.7, or 1.4 microg/kg subcutaneously weekly for 24 weeks alone, or in combination with ribavirin 600, 800, or 1,000 to 1,200 mg orally daily. Patients were evaluated during treatment and after a 24-week follow-up period for safety and efficacy. Detailed pharmacokinetic assessments were performed at weeks 1 and 4. PEG-Intron alone produced expected dose-related reductions in white cells, neutrophils and platelets. Addition of ribavirin reduced hemoglobin levels in a dose-related manner, did not further reduce PEG-Intron-induced decreases in neutrophil or white cell count, and increased platelet counts. Neutrophil function tests (C5a and FMLP migration, killing curves) were unaltered. Reported adverse events (flu-like symptoms, asthenia) were qualitatively similar in all dose groups. Anti-HCV activity, as measured by loss of detectable serum HCV RNA (i.e. <100 copies/mL) at the end of treatment (week 24) and after 24 weeks of follow-up (week 48) showed dose-response trends for PEG-Intron. At each PEG-Intron dose level, anti-HCV activity was higher in patients coadministered ribavirin than in patients treated with PEG-Intron monotherapy. There was no evidence of pharmacokinetic interactions with either drug. We conclude that the safety and tolerability of combined PEG-Intron/ribavirin and PEG-Intron alone were comparable. Combined PEG-Intron/ribavirin showed dose-related synergistic anti-HCV effects, which were numerically superior to those obtained with PEG-Intron monotherapy.

Efficacy of the cation exchange resin, sodium polystyrene sulfonate, to decrease iron absorption.

BACKGROUND: Iron is not bound by charcoal; therefore, a method of binding iron in the gastrointestinal tract to prevent absorption in iron overdose is needed. This study investigated the efficacy and safety of sodium polystyrene sulfonate to prevent absorption of iron in human volunteers. METHODS: Six adult volunteers completed this prospective crossover trial. Following an oral dose of elemental iron 10 mg/kg, each subject received sodium polystyrene sulfonate 30 g or water as control. Baseline and serial serum iron samples were drawn to determine pharmacokinetic parameters. RESULTS: A trend toward increased time to peak following sodium polystyrene sulfonate compared to the control arm (5.7 vs 3.6 hours) was observed but was not statistically significant (p = 0.517). A trend toward smaller area-under-the-curve for the sodium polystyrene sulfonate was evident but was not statistically significant (p = 0.77). Iron concentration increased on average 298 mcg/dL and 370 mcg/dL above baseline in the treatment and control arms (p = 0.44). Sodium polystyrene sulfonate is not an effective method of decontamination for iron overdose.

Thirteen-week dietary intake of rapeseed oil or soybean oil as the only dietary fat in Wistar Kyoto rats-change in blood pressure.

Wistar Kyoto (WKY) rats were fed a diet containing 10% rapeseed (canola) oil or soybean oil as the only dietary fat for 13 weeks. From week 5 of feeding, systolic blood pressure of the canola oil group became higher than that of the soybean oil group. The 13-week canola oil intake increased plasma levels of Na(+) and lipids, and decreased the level of K(+) compared to those in the soybean oil group. The canola oil group also showed a high density of neutrophils and a low density of platelets compared to the soybean oil group. Moreover, the activities of catalase and superoxide dismutase in the hepatic cytosol were depressed in the canola oil group. The mechanisms for the higher blood pressure are unclear. However, an increase in body fluid via activation of Na(+) pump or Na(+), K(+)-ATPase and/or a blunt endothelium-dependent vasodilation by increased superoxide might have relevance to the elevated blood pressure. The increased plasma lipids and the changes in the densities of platelets and neutrophils appear not to be critical in WKY rats. However, these would tend to promote peripheral vascular lesions in the strains, such as spontaneously hypertensive rats and stroke-prone spontaneously hypertensive rats, which are prone to present atheroscrelotic vascular injury.

Immunomodulatory activity of Withania somnifera.

Administration of an extract from the powdered root of the plant Withania somnifera was found to stimulate immunological activity in Babl/c mice. Treatment with five doses of Withania root extract (20 mg/dose/animal; i.p.) was found to enhance the total WBC count (17125 cells/mm(3)) on 10th day. Bone marrow cellularity (27x10(6) cells/femur) as well as alpha-esterase positive cell number (1800/4000 cells) also increased significantly (P<0.001) after the administration of Withania extract. Treatment with Withania extract along with the antigen (SRBC) produced an enhancement in the circulating antibody titre and the number of plaque forming cells (PFC) in the spleen. Maximum number of PFC (985 PFC/10(6) spleen cells) was obtained on the fourth day. Withania extract inhibited delayed type hypersentivity reaction in mice (Mantoux test). Administration of Withania extract also showed an enhancement in phagocytic activity of peritoneal macrophages (76.5 pigmented cells/200) when compared to control (31.5/200 cells) in mice. These results confirm the immunomodulatory activity of W. somnifera extract, which is a known immunomodulator in indigenous medicine.

Effect of methanolic extract of Enicostemma littorale on Dalton's ascitic lymphoma.

The antitumour activity of methanolic extract of Enicostemma littorale (MEL) has been evaluated against Dalton's ascitic lymphoma (DAL) in swiss albino mice. A significant enhancement of mean survival time of MEL treated tumour bearing mice was found with respect to control group. MEL treatment was found to enhance peritoneal cell counts. When these MEL treated animals underwent i.p. inoculation with DAL cells, tumour cell growth was found to be inhibited. After 14 days of inoculation, MEL is able to reverse the changes in the haemotological parameters, protein and PCV consequent to tumour inoculation.

Growth hormone and markers of immune function in children with renal transplants.

Lymphocyte subsets and T cell activation markers were measured in ten children with renal transplants for up to 1 year before and during their 1st year of recombinant human growth hormone (rhGH) treatment. The number of lymphocytes, helper or cytotoxic T cells or natural killer cells, and the T cell expression of CD25, CD26 and HLA-DR antigens were not altered by rhGH. B cell numbers declined both before and during treatment. There was no difference in lymphocyte subset numbers between children with and without rejection episodes.

Effects of high nitrate intake in rats.

The purpose of this study was to determine the effects of administration of high dose nitrate in drinking water on weight gain, hematological parameters and osmotic fragility in rats. We compared these parameters in 40 rats divided into four groups (one control and three treatment groups). Control animals drank filtered tap water containing a maximum of 10 mg/l nitrate while the treatment groups drank 100 mg/l, 200 mg/l and 400 mg/l nitrate-containing water ad libitum for 60 days. Animals in the treatment groups gained less weight than the control group and the differences between the control and treatment groups were statistically significant (p < 0.05). At the concentration of 100 mg/l nitrate, platelet counts and hemoglobin levels were significantly increased compared with the control group (p < 0.05). At the concentration of 200 mg/l nitrate, erythrocyte counts, hemoglobin and hematocrit levels were significantly increased compared with the control group (p < 0.05). At the concentration of 400 mg/l nitrate, platelet counts were decreased significantly when compared with the first two treatment groups (p < 0.05). There were statistically significant differences in osmotic fragility ratios between treatment groups and the control group (p < 0.05). We concluded that high nitrate intake in drinking water decreases weight gain, affects hematological parameters by inducing bone marrow activity at low doses and inhibiting it at high doses, and increases erythrocyte osmotic fragility.

Hemostatic effects of low-dose protamine following cardiopulmonary bypass.

Twenty-eight patients undergoing cardiac surgery were prospectively studied and were assigned to two groups. The patients received 0.8- (Group L) or 2.0-fold (Group H) dose of protamine for the neutralization after cardiopulmonary bypass (CPB) which was determined by Hepcon HMS(R) assay system in which the reagent chamber containing the concentration of protamine that completely neutralized the heparin had the shortest clotting time. Mean dose of protamine was 1.60 +/- 0.50 mg kg(-1) in Group L, and 3.56 +/- 1.48 mg kg(-1), respectively. Activated clotting times (ACT) were comparable between the two groups through this study period. In Group H, platelet counts significantly decreased to 69% of that before protamine administration, and plasma platelet factor 4 level significantly increased to approximate 2-fold of that before protamine administration just after protamine administration, respectively. However, these phenomena were not observed in Group L. In addition, these hemostatic changes occurred transiently just after protamine administration. We conclude that the low-dose protamine may prevent transient platelet depletion following CPB. Low-dose protamine can neutralize anticoagulation effect of heparin sufficiently and may mitigate protamine-induced platelet dysfunction.

Dental pulp infarction in female rats following inhalation exposure to 2-butoxyethanol.

Female Fischer 344 (F344)/N rats (10 per exposure group) were exposed to 2-butoxyethanol (BE) vapors (0, 31, 62.5, 125, 250, or 500 ppm 6 h/d, 5 d/wk, for 13 weeks) to characterize its prechronic toxicity. Dental lesions consisting of bilateral multifocal dental pulp thrombosis, pulp infarction, and odontoblast infarction were noted in the maxillary incisors of 3 of 4 rats from the 500-ppm group that were sacrificed when moribund during the first week of exposure. In addition, 1 rat from the 500-ppm group that was sacrificed on day 32 had similar unilateral incisor lesions but with additional findings consistent with a unilateral maxillary incisor fracture. In contrast, rats sacrificed after 13 weeks of exposure lacked dental lesions. In conclusion, BE has the potential to cause pulp thrombosis and odontoblast infarction in female rats. The apparent variability in response to BE noted in moribund sacrificed vs terminally sacrificed rats was attributed to development of tolerance to BE-induced hemolysis and subsequent incisor regeneration.

Acute parietal and chief cell changes induced by a lethal dose of lipopolysaccharide in mouse stomach before thrombus formation.

The common lipopolysaccharide (LPS)-induced gastric lesions, such as erosions or ulcers, have been investigated in depth. Little is known, however, about the acute gastric lesions following a high dose of LPS. In a time-course study, ICR female mice were given a high subcutaneous dose of LPS (50 mg/kg). Mice were sacrificed at 4, 6, 12, and 24 hours after dosing and were assessed histopathologically for acute gastric lesions. The major gastric changes were seen in the fundic region and included vacuolar degeneration of parietal cells and apoptosis of chief cells. The vacuole in parietal cells was apparent as early as 4 hours postinjection (PI), and apoptosis of chief cells was apparent at 12 hours PI. Thrombus formation, in contrast, was not seen until 24 hours PI. No erosion, ulcer, or hemorrhage was seen in any gastric region in any of the treated animals at 24 hours PI. These results indicate that a subcutaneous high dose of LPS in mice causes vacuolar degeneration of parietal cells and apoptosis of chief cells before thrombus formation or subsequent ulcerative lesions.

Effect of coadministration of clozapine and fluvoxamine versus clozapine monotherapy on blood cell counts, plasma levels of cytokines and body weight.

RATIONALE: Clozapine treatment is associated with side-effects such as blood cell dyscrasias and weight gain. Increased plasma levels of the cytokines and soluble cytokine receptors leptin, tumor necrosis factor-alpha (TNF-alpha), soluble TNF receptors p55 and p75, as well as toxic metabolites of clozapine, have been suggested as the basis for these side-effects, OBJECTIVES: This study examined whether the coadministration of the selective serotonine reuptake inhibitor fluvoxamine, which interferes with clozapine's hepatic metabolism, affects the immunomodulation by clozapine and some of its side-effects. METHODS: The following parameters were measured: circulating levels of the cytokines and soluble receptors, plasma concentrations of clozapine and its metabolite N-desmethylclozapine, body weight and blood cell counts in 11 and 12 schizophrenic inpatients on combined and monotherapy, respectively, before and during the first 6 weeks of medication. RESULTS: On the basis of comparable plasma levels of clozapine and N-desmethylclozapine, the coadministration of fluvoxamine 1) attenuated and delayed the clozapine-induced increase in TNF-alpha plasma levels, 2) enhanced and accelerated the clozapine-induced increase in leptin plasma levels without significant effect on clozapine-induced weight gain, and 3) decreased granulocyte counts. CONCLUSIONS: As clozapine, its metabolite N-desmethylclozapine and fluvoxamine are unlikely to make these differences, other metabolites might be responsible. The coadministration of clozapine and fluvoxamine offers the opportunity to investigate further the putative associations between certain metabolites, immunomodulation and these side-effects.

Amifostine in the treatment of low-risk myelodysplastic syndromes.

BACKGROUND AND OBJECTIVE: The phosphorylated aminothiol agent amifostine (Ethyol) protects bone marrow and other tissues from toxicity due to ionizing radiation and antineoplastic drugs, and stimulates progenitors from normal and myelodysplastic bone marrow. Contrasting results have been published so far on the effectiveness of amifostine in correcting cytopenia in patients with myelodysplastic syndromes (MDS). DESIGN AND METHODS: In a pilot phase II study we treated 26 patients with low risk MDS (13 RA, 2 RARS, 2 CMML, 9 RAEB with blasts < 10%) with amifostine (200 mg/m(2 )x 3/week for 4 weeks). RESULTS: Hemoglobin concentration, reticulocyte, neutrophil and platelet counts increased respectively in 6 (23%), 11 (42%), 13 (50%) and 9 (34%) of patients. Red cell transfusions were reduced (> 50%) in 4/26 patients and abolished in 1/26. Unexpectedly a significant decrease in soluble transferrin receptor level at week 4 of therapy, compared to the basal level (p<0.04), was observed in the whole population of patients. INTERPRETATION AND CONCLUSIONS: Amifostine can ameliorate cytopenia in some patients with MDS, with few and mild side effects. Neutropenia is more likely to be corrected than anemia or thrombocytopenia. Mechanisms underlying this biological effect remain to be clarified.

Toxicity and mutagenicity studies of DN-50000((R)) and RP-1((R)) enzymes.

Improved yields of 5'-nucleotides from yeast extract for food flavouring purposes is possible through use of microbial nucleotidases, which will be available to food processors as the flavour enhancer Aromild. The safety of these enzymes, 5'-phosphodiesterase (RP-1) and the 5'-adenylic deaminase (DN-50000) was investigated in male and female rats. Feeding rats a diet admixed with 500, 2000 and 8000 mg/kg body weight of DN-50000 for 35 days resulted in no significant dose-related changes in body weight, water consumption, urinalysis, haematological profiles, blood chemistry or histopathological profiles of either male or female rats from consumption of the enzyme preparation. There was an increase in the absolute and/or relative organ weights of the submaxillary (salivary) glands in both sexes at 8000 mg/kg. The no-observed-effect level (NOEL) for DN-50000 was clearly evident at 2000 mg/kg. Consumption of RP-1 enzyme for 35 days at dietary levels of 500, 2000 and 8000 mg/kg body weight resulted in no significant changes in the above mentioned parameters, which could be directly attributed to a dose-related effect, with the exception of an increase in the absolute and relative weights of submaxillary glands of both male and female rats in the 2000 and 8000 mg/kg groups. The increase in weight of the submaxillary glands was associated with histological evidence of acinar cell hypertrophy. The NOEL for dietary consumption of RP-1 was clearly evident at 500 mg/kg. In a follow-up study in which rats were gavaged with 2000 mg/kg RP-1, submaxillary gland hypertrophy did not occur. These studies suggest that DN-50000 and RP-1 exert an action on submaxillary glands similar to that which has been previously reported for the enzyme pancreatin. Neither DN-50000 nor RP-1 were mutagenic in the Ames assay using Salmonella typhimurium strains TA100, TA1535, TA98, TA1537 or Escherichia coli strain WP2uvrA, in the presence or absence of S9 mix.

Immunopathology of a two-hit murine model of acid aspiration lung injury.

In a two-hit model of acid aspiration lung injury, mice were subjected to nonlethal cecal ligation and puncture (CLP). After 48 h, intratracheal (IT) acid was administered, and mice were killed at several time points. Recruitment of neutrophils in response to acid was documented by myeloperoxidase assay and neutrophil counts in bronchoalveolar lavage (BAL) fluid and peaked at 8 h post-IT injection. Albumin in BAL fluid, an indicator of lung injury, also peaked at 8 h. When the contributions of the two hits were compared, neutrophil recruitment and lung injury occurred in response to acid but were not greatly influenced by addition of another hit. Neutrophil sequestration was preceded by elevations in KC and macrophage inflammatory protein-2alpha in plasma and BAL fluid. KC levels in BAL fluid were higher and peaked earlier than macrophage inflammatory protein-2alpha levels. When KC was blocked with specific antiserum, neutrophil recruitment was significantly reduced, whereas albumin in BAL fluid was not affected. In conclusion, murine KC mediated neutrophil recruitment but not lung injury in a two-hit model of aspiration lung injury.

Modulation of endocrine systems and food intake by green tea epigallocatechin gallate.

Green tea polyphenols, especially the catechin, (-)-epigallocatechin gallate (EGCG), have been proposed as a cancer chemopreventative based on a variety of laboratory studies. For clear assessment of the possible physiological effects of green tea consumption, we injected pure green tea catechins ip into rats and studied their acute effects on endocrine systems. We found that EGCG, but not related catechins, significantly reduced food intake; body weight; blood levels of testosterone, estradiol, leptin, insulin, insulin-like growth factor I, LH, glucose, cholesterol, and triglyceride; as well as growth of the prostate, uterus, and ovary. Similar effects were observed in lean and obese male Zucker rats, suggesting that the effect of EGCG was independent of an intact leptin receptor. EGCG may interact specifically with a component of a leptin-independent appetite control pathway. Endocrine changes induced by parenteral administration of EGCG may relate to the observed growth inhibition and regression of human prostate and breast tumors in athymic mice treated with EGCG as well as play a role in the mechanism by which EGCG inhibits cancer initiation and promotion in various animal models of cancer.

Hematological toxicity associated with tiazofurin-influence on erythropoiesis.

In this study hematological toxicity was analyzed after the single and repeated applications of tiazofurin (TZF). Cellularity of bone marrow, spleen and peripheral blood was examined, spanning the period of fifty days after the initial application. Analysis of hematological parameters was performed by slightly modified conventional techniques. The fraction of erythroid series was monitored during the experiment. Presented data describe kinetics of damage and recovery of hemopoietic tissue. Our results indicate that the effect of tiazofurin on cellularity of bone marrow and spleen and on erythropoiesis is reversible and dose dependent within tested dose range and therapeutic regimes. Twenty days after the application normal function of hemopoietic tissues was restored. This approach and results can be useful in defining the timing for sequencing and combination therapy with tiazofurin.