Suppression of experimental zymosan‐induced arthritis by intraperitoneal administration of adenosine

The anti‐inflammatory effect of methotrexate (MTX) is mediated by the increasing extracellular concentration of adenosine. The response of the immune system to activation of cell membrane subclass receptors for adenosine initiates intracellular signaling pathways, which causes immunomodulatory responses. To test the direct immunomodulatory effects of systemic administration of adenosine on animal model of inflammation, zymosan induced arthritis (ZIA) in mice was employed. Sterile zymosan (30 µg) was injected directly into the knee cleft of 60 mice, divided into 3 equal groups. The experimental groups received, every second day, 0, 0.25, and 0.5 mg/kg adenosine intraperitoneally. Inflammatory intensity was evaluated clinically by knee swelling measurement, histology, the total white blood cell (WBC) count, and serum tumor necrosis factor‐alpha (TNF‐α) levels served as markers of systemic inflammatory reaction. As observed, only the mice that received the higher dose of 0.5 mg/kg adenosine developed a significantly milder arthritis. A 23.9% reduction (P < 0.004) of the mean knee diameter swelling was noted. The histological inflammatory parameters and WBC count in the 0.5 mg/kg adenosine‐treated mice were also decreased (6,555 ± 510/mm³ vs. 9,250 ± 530 WBC/mm³ in the untreated mice, P > 0.006; 9,188 ± 588 WBC/mm³ in the 0.25 mg/kg adenosine‐treated group). Serum TNF‐α levels were significantly reduced (78.1 pg/ml in the 0.5 mg/kg adenosine‐treated group vs. 124.3 pg/ml, in the control group, P < 0.004). The data indicate a remarkable clinical beneficial effect, as well as a local and systemic anti‐inflammatory response that was noted on administration of 0.5 mg/kg adenosine every alternate day to mice with inflammatory arthritis. Drug Dev. Res. 57:182–186, 2002. © 2003 Wiley‐Liss, Inc.     

Continuous rat intravenous infusion

Hypovolemic shock and ischemic injury to the graft commonly cause death in small animals after organ transplantation. A venous line must be readily available to replace fluids before fatal complications occur. To establish a venous line, researchers expose a vein by preliminary surgery. This time-consuming procedure adds unnecessary trauma to the recipient and worsens the results. The possibility of long-term fluid transfusion in small animals by serial injections at close intervals is quite limited. We describe a simple technique of continuous IV infusion by catheterization of the rat dorsal penile vein with a 24-gauge, 3/4-inch catheter. This easy-to-learn technique has permitted us to establish a venous line quickly without trauma in 148 rats while doing donor and recipient procedures for small bowel and ileocecal segment transplantation. The technique we describe has eliminated one of the most frequent causes of postoperative mortality after organ transplantation—hypovolemic shock. We would like to emphasize that other measures, including avoiding massive bleeding and reducing operative and warm ischemic time, are also very important in preventing this complication. The massive IV infusion alone may not totally eliminate hypovolemic shock if other factors are neglected. The use of this technique has allowed us to perform small bowel transplantation with 90% success. © 1994 Wiley-Liss, Inc.     

CLEAVAGE OF HUMAN SERUM TRANSFERRIN WITH N-BROMOSUCCINIMIDE*

Human serum transferrin was fragmented by N-bromosuccinimide and reduction-alkylation. It was observed that there were at least two each of tryptophanyl-serine and tryptophanyl-aspartic acid, and one each of tryptophanyl-alanine and trypto-phanyl-glutamic acid bonds. The size of fragments detected by polyacrylamide gel electrophoresis ranged from 8,000 to 70,000 daltons. Several of the fragments were isolated in a homogeneous form with respect to molecular weight, but were shown to be mixtures of at least five molecular species each by end group analysis.     

Pulmonary Targeting of Liposomal Triamcinolone Acetonide Phosphate

Purpose. To explore the use of triamcinolone acetonide phosphate liposomes as a pulmonary targeted drug delivery system. Methods. Triamcinolone acetonide phosphate liposomes composed of 1,2-distearoyl phosphatidylcholine and 1,2-distearoyl phosphatidyl glycerol and triamcinolone acetonide 21-phosphate dipotassium salt were prepared by dispersion and extruded through polycarbonate membranes. Encapsulation efficiency and in vitro stability at 37°C were assessed after size exclusion chromatography. TAP liposomes (TAP-lip) or TAP in solution (TAP-sol) were delivered to rats either by intratracheal instillation (IT) or intravenous (IV) administration. Pulmonary targeting was assessed by simultaneous monitoring of glucocorticoid receptor occupancy over time in lung (local organ) and liver (systemic organ) using an ex vivo receptor binding assay as a pharmacodynamic measure of glucocorticoid action. Results. In vitro studies in different fluids over 24 hours, showed that more than 75% of the TAP remained encapsulated in liposomes. Cumulative pulmonary effects after IT administration of TAP-lip were 1.6 times higher than liver receptor occupancy. In contrast, there was no difference in the pulmonary and hepatic receptor occupancy time profiles when TAP was administered intratracheally as a solution. No preferential lung targeting was observed when TAP-lip was administered IV. As indicated by the mean effect times, lung receptor occupancy was sustained only when TAP-lip was administered IT. Conclusions. Intratracheal administration of TAP-lip provided sustained receptor occupancy, and increased pulmonary targeting which was superior to IT administration of TAP-sol or IV administration of TAP-lip. The use of liposomes may represent a valuable approach to optimize sustained delivery of glucocorticoids to the lungs via topical administration.     

Occupational exposure to Cr(VI): comparison between chromium levels in lymphocytes,erythrocytes, and urine

 The relationships between chromium (Cr) levels in lymphocytes, erythrocytes, urine, and ambient air were compared among 14 chrome-platers from a metallurgic plant in Bulgaria and two groups of local controls, one from the same heavily polluted industrial town as the chrome-platers (n=11) and one from a seaside resort town 100 km away (n=6). Among the chrome-platers, the Cr concentration in peripheral lymphocytes was positively correlated with total Cr and Cr(VI) levels in ambient air and with Cr excretion in urine. As compared to the controls, the chrome-platers had mean Cr levels in lymphocytes twice as high, in erythrocytes ninefold higher, and in urine fourfold to eightfold higher. Although Cr levels in urine and lymphocytes were similar between the two control groups, levels in erythrocytes were 3 times higher among subjects from the industrial area than among those from the seaside town. The study suggests that lymphocyte Cr could be a good indicator of the Cr body burden caused by high exposures to Cr(VI), such as in electroplating operations. In these conditions, erythrocyte Cr may be less useful, possibly owing to increased toxicity due to the high affinity of erythrocytes for Cr. However, when exposure is lower, such as in most environmental situations, erythrocyte Cr should provide a better and more sensitive index than lymphocyte Cr. By contrast, urinary Cr, which provides information on total Cr exposure, including Cr(III) from dietary and environmental sources, does not seem to be of value for studying occupational exposure to Cr(VI). Received: 22 September 1995/Accepted: 2 January 1996     

TP53 codon 72 polymorphism in radiation-associated human papillary thyroid cancer

The study investigated an association between the germline polymorphism at TP53 codon 72 and the development of papillary thyroid cancer (PTC) following exposure to radiation from the Chernobyl accident. TP53 genotype was examined in 48 pediatric/adolescent (age at diagnosis <18 years) and 68 adult post-Chernobyl patient with PTC, 53 adult patients with sporadic PTC and 313 healthy individuals from Russian-Ukrainian population. In addition, we evaluated loss of heterozygosity for TP53 and the allele expression ratio. The genotype of the patients was correlated with clinicopathological data. Arg TP53 homozygotes were found to be significantly underrepresented among adults with post-Chernobyl PTC, but not in children and adolescents when compared with sporadic PTC cases and the general population. In the tumors, cell transformation did not lead to allelic loss or biased TP53 allele expression in heterozygous individuals. None of TP53 genotypes specifically associated with tumor stage and morphology, however there were particular correlations with lymph node status in certain age groups of radiation-associated cases not seen in sporadic PTCs. The findings suggest TP53 allele combinations other than Arg/Arg may contribute to the risk of development of PTC in individuals exposed to radiation during their late childhood, adolescence or in young adulthood.     

Amisulpride treatment of clozapine-induced hypersalivation in schizophrenia patients: a randomized, double-blind, placebo-controlled cross-over study

The beneficial effect of sulpiride augmentation of clozapine therapy for treatment-resistant schizophrenia patients is enhanced by its antisalivatory effect on clozapine-induced hypersalivation (CIH). Amisulpride, similar to sulpiride, is a substitute benzamide derivative with higher selective binding to the D2/D3 dopamine receptor. We hypothesized that add-on amisulpride would also be beneficial in controlling CIH. In a randomized, double-blind, placebo-controlled cross-over study, 20 clozapine-treated schizophrenia (DSM-IV criteria) inpatients with CIH were randomly initially assigned to add-on amisulpride (nine patients; 400 mg/day up-titrated from 100 mg/day over 1 week) or placebo (11 patients). Primary outcome was change in the five-point Nocturnal Hypersalivation Rating Scale (NHRS). Other measures included the Positive and Negative Syndrome Scale (PANSS), Clinical Global Impression scale (CGI) and Simpson-Angus Scale (SAS). Mean NHRS indices were considerably lower with amisulpride (1.79 +/- 1.25) than with placebo (2.63 +/- 1.33) [F(1,38) = 5.36, P < 0.05]. With amisulpride treatment, there was a significant improvement on the negative symptoms subscale of the PANSS [F(3,57) = 3.76, P < 0.05], but not on the SAS, CGI or other subscales of the PANSS (all F < 1). Short-term amisulpride augmentation has a strong ameliorating effect on CIH. A long-term, large-scale study with a broader dose range is warranted to evaluate the stability of this effect across time.