Resistance to silica-induced lung fibrosis in senescent rats: role of alveolar macrophages and tumor necrosis factor-alpha (TNF)

The purpose of the present study was to investigate the effect of aging on silica-induced lung toxicity. In young animals silica induced a significant increase in bronchoalveolar lavage tumor necrosis factor-alpha (TNF), lactate dehydrogenase as well as in cell numbers, which correlate with increased collagen deposition and silicotic nodules formations. In old rats, however, no changes in bronchoalveolar lavage or lung parameters were observed following silica instillation. These in vivo results were also confirmed in vitro, where silica failed to induce TNF release in alveolar macrophages obtained from old animals. This defective response to silica could be explained with defective protein kinase C translocation, due to a reduction in its anchoring protein RACK-1 with aging. Overall, these data indicate that the understanding of the molecular mechanisms undelaying toxicity is crucial to define the influence of age on the toxic response and progression of the disease.

Effect of natural antioxidants and apocynin on LPS-induced endotoxemia in rabbit

The objective of this study was to compare the prophylactic effects of the natural antioxidant from spinach (NAO) and apocynin, on the hepatic oxidative stress and liver damage induced by lipopolysaccharide (LPS). Male New Zealand rabbits were challenged with LPS with or without 8 days of antioxidant pretreatment. Pretreatment with NAO, but not apocynin, significantly (p < 0.05) decreased the levels of hydroperoxides and malondialdehyde (MDA) in the liver cytosolic fraction and the activity of NADPH oxidase-generated superoxide in the microsomal fraction, compared to LPS alone. The activity of glutathione peroxidase (G-POX) was significantly (p < 0.05) increased in the LPS-treated group, whereas treatment with NAO, but not apocynin, significantly (p < 0.05) decreased G-POX activity. Pretreatment with the same antioxidants had no significant effects on superoxide dismutase (SOD) activity, whereas an increased level of catalase (CAT) was obtained in all LPS-treated groups. TUNEL immunohistochemical staining in the LPS-treated animals indicated that there was no increase in apoptosis outside of necrotic foci. However, apoptotic hepatocytes were observed within areas of focal necrosis in animals exposed to LPS alone or LPS plus apocynin. Hepatocyte cell proliferation was tested by the proliferating-cell nuclear antigen (PCNA) tool, which indicated a proliferative effect in the LPS group, whereas the effect disappeared in the antioxidant-treated groups. The prophylactic effect of NAO on liver pathology and the significant decreases in lipid peroxidation products and NADPH oxidase activity suggest the use of NAO as an efficient strategy for treatment of endotoxemia.

Ability of recombinant human TNF binding protein-1 (r-hTBP-1) to inhibit the development of experimentally-induced endometriosis in rats

The aim of this study was to assess whether r-hTBP-1 (recombinant human tumor necrosis factor binding protein-1), the soluble form of tumor necrosis factor-alpha (TNF) receptor type 1 might be effective in counteracting the proliferation of ectopic endometrium using an in vivo experimental model of endometriosis. The in vivo model involved transplanting a square fragment of autologus uterine tissue onto the inner surface of the abdominal wall in rats. r-hTBP-1 was administered for 1 week at 10 mg/kg, s.c. divided into two daily injections. The gonadotropin-releasing hormone antagonist antide was used for reference and given at the dose of 2 mg/kg, s.c. every 3 days for 1 week. The animals were killed 2 and 9 days after the last treatment and the size of endometriotic implants measured. Blood samples and spleens were also taken for assessment of estradiol-17beta levels and natural killer (NK) activity in vitro against murine YAC cells, respectively. The results of this study indicate that r-hTBP-1 is effective in reducing the size of the endometriotic-like foci mainly at the later sacrifice time-point when they were significantly decreased by 64% as compared to control animals. As expected, antide induces an almost complete and statistically significant remission both at the 2-day (94%) and the 9-day (88%); sacrifice time-point. Histological examination indicates that, compared to controls, r-hTBP-1 induces a slightly increased degeneration of the stromal tissues of the implants at both examination times and, limitedly to the earlier observation time, of the mucosal epithelium. No differences in the spleen cell NK activity were observed at either sacrifice time-points in any treatment group. Estradiol-17beta concentrations are significantly decreased in the antide-treated groups only at 9 days while no statistically significant changes are found in the animals receiving r-hTBP-1. The results of this study carried out in a rat experimental model of endometriosis provide evidence of the potential effectiveness of r-hTBP-1 in this pathological condition and support the role of TNF in its development.

[Dexketoprofen trometamol in the treatment of acute migraine attack]

BACKGROUND

Migraine is a common, very disabling pain condition: the occurrence of an acute attack often requires bedrest and prevents from participating in normal activities. Nonsteroidal anti-inflammatory drugs are widely used in the symptomatic treatment of migraine. Aim of this study was to evaluate the efficacy and safety of a potent new formulation, dexketoprofen trometamol (DT), in the treatment of migraine pain.

METHODS

The study enrollment was 42 women (mean age 37.2 +/- 12.2, range 21-65) suffering from migraine, with (n = 6) and without (n = 36) aura, diagnosed according to the International Headache Society criteria. Patients were asked to treat a single attack with a 25 mg dose of DT. The primary efficacy criterion was the change in migraine pain, recorded on a Visual Analogue Scale (VAS) immediately before and at 30, 60, 120, 240 minutes after assumption. The presence of accompanying symptoms and the onset of side effects were also considered.

RESULTS

Pain intensity significantly decreased after drug intake, showing a tendency toward a reduction along the time. The drop in mean VAS values resulted already significant at 30 minutes after DT assumption. Also the reported incidence of accompanying symptoms (nausea, vomiting, photophobia and phonophobia) significantly decreased after treatment. No serious adverse event was reported during the study. All the adverse events recorded were of mild severity and did not require any specific medical treatment.

CONCLUSIONS

DT proved to be an effective and safe oral therapy for the treatment of migraine attack.

The prophylactic effects of natural water-soluble antioxidant from spinach and apocynin in a rabbit model of lipopolysaccharide-induced endotoxemia

Radical-scavenging antioxidants, as part of the cellular defense system, function to inhibit the formation and propagation of free radicals and active oxygen species formation. In previous studies we demonstrated that endotoxin lipopolysaccharide (LPS) promotes oxidative stress and associated pathological changes in a rat model and that use of selected antioxidants was effective in reducing LPS-related lipid peroxidation product formation in the liver, as well as LPS-related pathological changes in different organs. In this study, several toxicological parameters (ie, clinical signs, blood chemistry, and histopathological changes) were compared among groups of male New Zealand rabbits injected with LPS following prophylactic pretreatment with either of 2 antioxidants, a group injected with LPS without pretreatment with antioxidants, groups injected with either of the 2 antioxidants only, and an untreated control group. The antioxidants used were a water-soluble natural antioxidant (NAO) from spinach and the NADPH oxidase inhibitor, apocynin. Exposure to LPS alone was associated clinically with depression, tachypnea, outer ear vasodilation, and iris congestion; biochemically with a significant increase in blood total bilirubin, transaminase activity, and glucose, total cholesterol, and triglyceride levels; macroscopically with multiple whitish areas in the liver; and histologically with hepatocellular focal necrosis and acute inflammation, thymic and splenic lymphoid necrosis and depletion, acute uveitis and hemorrhages in the ciliary processes, and decreased adrenal cortical cytoplasmic vacuolation considered consistent with depletion of steroidal hormone contents. The NAO had more effective prophylactic capacities than the apocynin. The protective effects were obvious in all investigated parameters. The results indicate the possible therapeutic efficacy of NAO in the treatment of clinical endotoxemia associated with gram-negative bacterial sepsis that is known to be associated with oxidative stress.

Determination of the clearance factor for transmissible spongiform encephalopathy agents during the manufacturing process of polygeline

OBJECTIVE

To determine the safety of polygeline, a gelatine-derived plasma substitute produced from bovine bones, in terms of safety for bovine spongiform encephalopathy (BSE) by evaluating the ability of the manufacturing process of polygeline to eliminate agents related to transmissible spongiform encephalopathy (TSE) through the validation of three main production steps.

DESIGN

Laboratory scale experimental process (in duplicate) using 20% hamster-adapted 263K scrapie-infected brain homogenate as infective titrated source (10(9) LD50/2 ml), added to each material before being processed and titrated in hamsters. Experiment 1: time/temperature dependency of gelatine autoclaving. Experiment 2: cross-linking and distillation. Experiment 3: final sterilization. Monitoring period: 1 year with daily animal clinical observation. Histology of all brains.

SETTING

LCG-RBM laboratories, Italy; strict GLP compliance.

MEASUREMENTS AND RESULTS

Heating the gelatine (at conditions lower than those used in production process) was very effective in inactivating the infectivity of TSE agents. Clearance factors were reproducible, dependent upon time and temperature, reaching a total theoretical process clearance in the range of 9.2-13.8 [6.9 + 2.3 (+ 4.6)] log10 LD50.

CONCLUSIONS

These experimental results provide further important data confirming the safety of the procedural steps; this complements the safety due to the careful sourcing of the raw material. There is high assurance that there is no significant risk of TSE transmission to humans by the therapeutic administration of polygeline.

Atriocaval mesothelioma in a male Sprague-Dawley rat

The histological, immunohistochemical, and electron microscopic characteristics of a spontaneous case of atriocaval mesothelioma are described in a 102-wk-old male Sprague-Dawley rat. The immunohistochemical characteristics of the tumor are compared with those of a pericardial mesothelioma in a female Sprague-Dawley rat.

Nasal formulations of ketorolac tromethamine: technological evaluation--bioavailability and tolerability in rabbits

This paper describes the development of a novel formulation of the powerful non narcotic analgesic ketorolac tromethamine. This drug is given orally three to four times/day to deliver a total of 30 to 60 mg of drug. Higher doses cannot be given orally because of gastrointestinal side effects and intramuscular injections, three times/day must then be used. The need for injections limits the drug to a clinical setting. Nasal delivery offers a method of achieving the high blood levels of repeated intramuscular injections in a formulation that can be easily applied by the patients. Four formulations were evaluated in "in vitro" and "in vivo" rabbit tests. The best formulation consisted of a 5% solution of ketorolac tromethamine containing 0.3% sodium glycocolate as a known mucosal drug absorption enhancer. Ketorolac applied in this way had a bioavailability greater than 80%. The controlled release nature of nasal delivery also doubled the drug's apparent half life. The drug formulation was stable in three-months stability tests and produced minimal nasal irritation.

Combination ultrafiltration and 6 M urea treatment of human growth hormone effectively minimizes risk from potential Creutzfeldt-Jakob disease virus contamination

Although genetically engineered human growth hormone (hGH) is now commercially available, native pituitary-derived hGH is still used by physicians in many countries for the treatment of hormone deficiency states. We describe a method using ultrafiltration and 6 M urea that reduced infectivity in human pituitary tissue that had been deliberately contaminated with scrapie virus (an animal analogue of human Creutzfeldt-Jakob disease virus) from an initial level of 10(9.7) infectious units to just 5 infectious units. Based on estimates of the frequency of contamination and infectivity levels in batches of human pituitaries, the use of this protocol to prepare GH from cadaveric human glands yields a calculated probability of exposure to a contaminated vial of not greater than 1 in 3.2 million recipients; therefore, native hormone prepared by this method may be considered to be essentially risk-free. The same methodology may be useful in the preparation of other hormones, such as prolactin, for which no synthetic substitutes are currently available, as well as biological products derived from sheep or cattle, that may be infected with scrapie or bovine spongiform encephalopathy.

Can potential hazard of Creutzfeldt-Jakob disease infectivity be reduced in the production of human growth hormone? Inactivation experiments with the 263K strain of scrapie. Rapid communication

Scrapie infectivity is reduced 5-6 logs following filtration through 100,000 MW cut-off filter plus overnight treatment with 6 M urea. These steps, applied to purified human Growth Hormone (hGH), increase the margin of safety of hGH.