Pulmonary actions of anandamide, an endogenous cannabinoid receptor agonist, in guinea pigs

Anandamide (arachidonylethanolamide), 5,8,11,14-eicosatetraenamide, (N-2-hydroxyethyl), was tested for bronchodilator and anti-inflammatory activities. Conscious guinea pigs were given cumulative i.v. doses of anandamide (1.0, 3.0, and 10.0 mg/kg) to assess its effect on dynamic compliance (Cdyn), total pulmonary resistance (RL), tidal volume (VT) and breathing frequency (f). Other guinea pigs were exposed to an aerosol of A23187 (6S-[6alpha(2S*,3S*),8beta(R*),9beta,11alpha]-5- (methylamino)-2-[[3,9,11-trimethyl-8-[1-methyl-2-oxo-2-(1H-pyrrol-2-yl)e thyl]-1,7-dioxaspiro[5.5]undec-2-yl]methyl]-4-benzoxazole carboxylic acid) until Cdyn decreased by 50% (approximately 5 min) and at 20 min, cumulative i.v. doses of anandamide (1.0, 3.0, and 10.0 mg/kg) were administered and reversal of Cdyn examined. After the final dose of anandamide, the animals were killed and excised lung gas volumes (ELGV), i.e., pulmonary gas trapping, measured. Other animals were treated i.v. with anandamide (10.0 mg/kg), exposed to an aerosol of A23187 until labored breathing began, and then killed 1 h later. Anandamide did not significantly affect Cdyn, RL, VT and f. ELGV values of anandamide-treated guinea pigs were not different from those of vehicle-treated animals. Anandamide failed to reverse A23187-induced decreases in Cdyn and to reduce A23187-associated ELGV increases. Also, it did not prevent the prolonged airway obstruction caused by A23187. Histological evaluation revealed that anandamide significantly reduced A23187-related airway epithelial injury and pulmonary leukocytosis. However, it did not prevent A23187-induced peribronchiolar granulocytic accumulation. Our results suggest that in vivo anandamide has minimal direct airway smooth muscle-related actions, however it may possess modest anti-inflammatory properties.

Rabbit urethral regeneration using small intestinal submucosa onlay grafts

OBJECTIVES

To determine if small intestinal submucosa (SIS) can evoke urethral regeneration.

METHODS

Twenty male white New Zealand rabbits were assigned to one of three experimental groups. Group 1 (n = 4) underwent simple urethrotomy and closure. Group 2 (n = 8), a second control group, underwent an onlay urethroplasty with a graft of full-thickness preputial skin from the host rabbit. Group 3 (n = 8) underwent an onlay urethroplasty with an SIS graft.

RESULTS

All eight SIS onlay grafts promoted regeneration of the normal rabbit epithelium supported by a well-vascularized collagen and smooth muscle backing. Preputial free onlay grafts maintained a keratinizing squamous cell epithelium with a poor supportive backing, which resulted in the formation of urethral diverticulum.

CONCLUSIONS

SIS onlay patch grafts for urethroplasty promote rabbit urethral regeneration.

Identification of rhesus macaques with spontaneous endometriosis

Rhesus macaques (Macaca mulatta) with endometriosis were identified using reproductive histories, serum levels CA-125, pelvic ultrasonography, laparoscopy, and histopathology. All animals were evaluated from a large breeding colony and had a history of infertility and/ or spontaneous abortions. Laparoscopy and ultrasonography were performed on 40 macaques: 27 macaques from the breeding colony with elevated CA-125 levels, ten macaques from the breeding colony with normal or low serum CA-125 levels, and three macaques from another facility with previously diagnosed spontaneous endometriosis. Clinical endometriosis was diagnosed by laparoscopy in 16/37 (43%) macaques from the breeding colony and was confirmed by histologic examination in all animals biopsied. The disease was classified as minimal (40%), mild (25%), moderate (10%), or severe (25%). The most common sites of endometriosis were the serosal surface of the uterus (75%) and the posterior cul-de-sac (75%). In this study, CA-125 levels were useful in identifying animals from the breeding colony with endometriosis. The rhesus macaque provides a valuable animal model to study endometriosis and potentially to assess efficacy of therapeutic agents for this disease condition.

Development and characterization of a porcine model to study osteoclast differentiation and activity

The study of osteoclast differentiation, function, and fate has been hampered by the lack of nonavian, nonrodent models in which biochemical and molecular studies can be conducted. The present study was undertaken to determine if osteoclasts could be generated from porcine bone marrow cells. Bone marrow from the long bones of neonatal female pigs was enriched for mononuclear cells and cultured in the presence or absence of 1,25-(OH)2D3, rhIL-11, or PGE2. A confluent layer of stromal cells was observed after 4-8 days in culture and multinucleated giant cells formed after 6-10 days of culture. The multinucleated cells stained positively for tartrate-resident acid phosphatase and formed resorption lacunae when exposed to bovine cortical bone slices. When examined by transmission electron microscopy, abundant mitochondria, perinuclear Golgi complexes, numerous variably sized vacuoles, prominent rough endoplasmic reticulum, and free polysomes were observed in the multinucleated cells. Stimulation of the in vitro generated osteoclasts with 10(-8) mol/L salmon calcitonin resulted in a three to fivefold increase in cAMP production and in cell retraction. Although the osteoclasts formed in the presence or absence of 1,25-(OH)2D3, 10-50-fold more osteoclasts were observed in the cultures treated with 1,25-(OH)2D3 in comparison to cultures without 1,25-(OH)2D3. Osteoclast differentiation was also stimulated by rhIL-11 and PGE2; although, the number of cells generated in 6-7 days was significantly less than the number obtained with 1,25-(OH)2D3, treatment. In addition, these multinucleated cells expressed high levels of Src kinase activity and responded to bafilomycin A1, an inhibitor of the vacuolar type H(+)-ATPase, treatment with a decrease in osteoclastic bone resorption. In summary, the porcine cells possess the major distinguishing characteristics of osteoclasts and provide an alternative mammalian model to study osteoclast differentiation and resorptive activity.

Characterization of small intestinal submucosa regenerated canine detrusor: assessment of reinnervation, in vitro compliance and contractility

PURPOSE

We characterized small intestinal submucosa regenerated canine bladder.

MATERIALS AND METHODS

We subjected 15-month small intestinal submucosa regenerated canine bladder strips to in vitro muscle bath compliance, contractility testing and immunohistochemical staining.

RESULTS

Compliance studies demonstrated no significant difference between small intestinal submucosa regenerated and control bladders, which were 30-fold more compliant than native small intestinal submucosal graft material. Contractility studies demonstrated contractile responses and innervation similar to those of normal canine bladder. Afferent nerves were demonstrated through immunohistochemical techniques.

CONCLUSIONS

These characteristics further support the regenerative capacity of small intestinal submucosa and its potential use as a bladder augmentation material.

Raloxifene, tamoxifen, nafoxidine, or estrogen effects on reproductive and nonreproductive tissues in ovariectomized rats

For the first time, four well-characterized compounds from four distinct chemical classes were directly compared for efficacy and potency in hone, uteri, lipids, and adipose tissues in an ovariectomized model with 6 month old rats. Five weeks of oral dosing confirmed that ethynyl estradiol, tamoxifen, and raloxifene are potent inhibitors of the loss in volumetric bone mineral density (BMD, mg/cc) induced by ovariectomy, as measured by computed tomography. In the metaphysis of distal femora from ovariectomized rats, analysis showed a significant 12-20% decrease (P< 0.01) in the BMD. Linear regression analysis was used to calculate half-maximal efficacious doses for ethynyl estradiol ED(50) =0.04mg /kg, which was threefold more potent than tamoxifen, which in turn was threefold more potent than raloxifene, which was more efficacious than nafoxidine. In the uterus, raloxifene had minimal effects on the endometrium and smaller effects on uterine eosinophil peroxidase activity than nafoxidine, tamoxifen, or estrogen, respectively. Estrogen was the most potent in reducing cholesterol levels in ovariectomized rats, whereas tamoxifen and nafoxidine were more effective than raloxifene in blocking gain in body weight. Distinct compounds had advantages in the management of bone, uterine, serum cholesterol, and adipose tissues after ovariectomy. The distinct pattern of pharmacological effects may be best understood in terms of their respective chemical structure, specifically estrogens, benzothiophenes (raloxifene), dihydronapthylenes (nafoxidine), and triphenylethylenes (tamoxifen). These data point to advantages of separate compounds in the management of bone, uterine, serum cholesterol, and adipose tissues after estrogen deficiency, and show that the benzothiophene raloxifene has potentially important advantages over estrogen, tamoxifen, or nafoxidine in the uterus.

Regenerative urinary bladder augmentation using small intestinal submucosa: urodynamic and histopathologic assessment in long-term canine bladder augmentations

PURPOSE

To evaluate small intestinal submucosa (SIS) as a possible bladder augmentation material.

MATERIALS AND METHODS

Nineteen male dogs underwent 35 to 45% partial cystectomy with immediate augmentation with SIS grafts. All dogs were evaluated pre- and postoperatively with blood chemistries, urine cultures, intravenous urograms, cystograms and cystometrograms. Postoperatively (1 to 15 months), bladders were examined with routine histology and image analysis.

RESULTS

All dogs survived their intended survival period without morbidity. All results were normal. Histologically, all 3 layers (mucosa, smooth muscle, serosa) of the normal bladder showed evidence of regeneration.

CONCLUSIONS

Small intestinal submucosa acts as a scaffold for bladder augmentation through regeneration and could be a potential option for bladder reconstruction.

Aerosolized LTB4 produces delayed onset increases in pulmonary gas trapping

Airway obstruction, as measured by increases in postmortem pulmonary gas trapping, and lung inflammatory changes were examined in guinea pigs exposed for up to 4 h to aerosols of leukotriene B4 (LTB4) or its non-chemotactic isomer, 6-trans-12-epi-LTB4. Airway obstruction and cytological responses in isomer-exposed animals were similar to those of unexposed control animals. LTB4-exposed animals had minimal inflammatory changes at 0.5 h but became dyspneic by 2 h and had increased airway obstruction, bronchoalveolar lavage neutrophils and eosinophils, and pulmonary tissue granulocyte scores. The LTB4-induced effects at 4 h were similar to those 2 h, except for further increase in BAL neutrophils and eosinophils. LTB4-induced airway obstructive and inflammatory changes were prevented by pretreatment with the LTB4 receptor antagonist SC-41930, but were unaffected by indomethacin. Thus, prolonged LTB4 inhalation can produce delayed onset airway obstruction that is stereospecific, cyclooxygenase-independent, and temporally associated with the influx of granulocytes into lung airways.

Detrusor regeneration in the rat using porcine small intestinal submucosal grafts: functional innervation and receptor expression

PURPOSE

To evaluate functional characteristics of regenerated bladder induced by small intestinal submucosa (SIS).

MATERIALS AND METHODS

Strips from bladder regenerated from SIS and normal rat bladder were evaluated by in vitro muscle bath contractility studies.

RESULTS

The present results indicate that SIS-regenerated bladder 1) demonstrates contractile activity; 2) expresses muscarinic, purinergic and beta adrenergic receptors; and 3) exhibits functional cholinergic and purinergic innervation that is similar to the normal rat urinary bladder muscle.

CONCLUSIONS

These functional characteristics of SIS-regenerated tissue demonstrated in the present study further support use of SIS material as a bladder augmentation material.

Experimental assessment of small intestinal submucosa as a bladder wall substitute

OBJECTIVES

This study determined the feasibility of promoting urinary bladder regeneration with porcine-derived small intestinal submucosa (SIS).

METHODS

Twenty-two Sprague-Dawley rats underwent partial cystectomy with immediate bladder augmentation with SIS. Bladders were harvested for histologic evaluation at 2, 4, 8, 12, 24, and 48 weeks.

RESULTS

Histologically at 2 weeks, there was infiltration of the graft material with viable host cells consisting of fibroblasts, macrophages, and blood vessels covered by complete mucosal urothelium comprised of transitional cells. During the next 10 weeks, collagen formation and maturation were noted, and by the end of 12 weeks, the SIS graft was comprised of a mature collagen matrix admixed with thinly scattered disorganized smooth muscle bundles and covered by normal urothelium. At 48 weeks, all three layers of the normal bladder (urothelium, smooth muscle, and serosa) were present and were grossly and microscopically indistinguishable from the normal rat urinary bladder.

CONCLUSIONS

This study further supports the concept of bladder regeneration and suggests that SIS may be a viable material for bladder augmentations.

Experimental hepatitis E in pregnant rhesus monkeys: failure to transmit hepatitis E virus (HEV) to offspring and evidence of naturally acquired antibodies to HEV

In an attempt to reproduce experimentally the fulminant hepatitis of pregnant women infected with hepatitis E virus (HEV), 4 nonpregnant and 6 pregnant rhesus monkeys in the first, second, or third trimester of pregnancy were inoculated intravenously with approximately 10(5.5) ID50 of HEV. Comparison of biochemical, histopathologic, and serologic profiles in pregnant and nonpregnant monkeys did not reveal an increase in the severity of hepatitis in the pregnant animals. Hematology and serum clinical chemistry values were in the normal range in all animals during the study. No evidence of neonatal infection with HEV was found in offspring. Two rhesus monkeys (1 pregnant, 1 nonpregnant) had naturally occurring anti-HEV antibodies prior to inoculation as detected by a standard ELISA and confirmed by a competition ELISA with hyperimmune chimpanzee serum. These animals demonstrated an anamnestic response when they were challenged with HEV.

Characterization of simian immunodeficiency virus (SIV) infected AA-2 cells by SEM and immunoelectron microscopy

The ultrastructural features of AA-2 cells infected with either of two strains of simian immunodeficiency virus (SIVMne-E11S or SIVSMM-PBj) were examined by scanning electron microscopy (SEM). Transformed CD4+ human B lymphocytes (AA-2) were inoculated with SIV and observed at 2, 4, and 7 days post-inoculation (dPI). Infected AA-2 cells were distinguished by the progressive loss of microvilli, and variable numbers of free or protruding spherical particles measuring 90-120nm in diameter along the cell surface. Syncytial cell formation (complexes of fused cells) and necrotic cells were evident at each time point with the most numerous observations at 7 dPI. While the distribution and severity of the viral induced changes increased with time and affected virtually all cells by 7 dPI, the alterations were detected sooner and were more pronounced in SIVSMM-PBj infected cells. This finding is consistent with the in vivo data from primate studies using the same strains of SIV. Syncytial cells exhibited slight to moderate indentations which appeared to coincide with the boundaries of individual cells forming the complex. The plasma membrane of syncytial cells was relatively smooth and lacked microvilli. Spherical particles and buds protruding from the plasma membrane were predominate features of syncytial cell surfaces. By the employment of antisera generated against whole SIVMne-E11S, both transmission and scanning immunoelectron microscopy confirmed the identity of the spherical structures as free and budding SIV virions.

Protection of mice from inhaled ricin by vaccination with ricin or by passive treatment with heterologous antibody

Mice were vaccinated subcutaneously with 25 micrograms kg-1 of ricin in the presence of Freund's complete adjuvant or Ribi adjuvant, followed by a boost 14 days later with 50 micrograms kg-1 ricin in Freund's incomplete adjuvant or Ribi adjuvant, respectively. Three subsequent boosts at 28-day intervals with 25 micrograms kg-1 ricin yielded high anti-ricin antibody titres as determined by ELISA. Vaccinated animals were exposed to an aerosolized LD99 dose of ricin. With the exception of one death not attributable to ricin intoxication, all vaccinated mice survived the lethal aerosol exposure. In addition, a passive protection regimen was evaluated in mice pretreated with 100 micrograms purified goat anti-ricin IgG administered intravenously, and then challenged with ricin intravenously. All were resistant to 125 micrograms kg-1 of ricin, a dose greater than 25 times the intravenous lethal dose. Mice injected intravenously with 5 mg of the same IgG were protected from a lethal aerosol challenge. These results indicated that it is possible to protect animals from inhaled ricin by vaccination or passive administration of specific antibodies.

Infection of Macaca radiata with viruses of the tick-borne encephalitis group

Our studies confirmed the susceptibility of Macaca radiata (bonnet macaques) to Kyasanur Forest disease (KFD) and enabled us to demonstrate KFD virus-specific gastrointestinal and lymphoid lesions. Significant histopathological changes occurred in the small and large intestine, spleen and lymph nodes; and viral antigens were found in these same organs by immunohistochemistry. Viral antigen-positive cells were always associated with histological evidence of necrosis, which suggests that cell death occurred directly from viral replication or secondarily from attack by immune mechanisms. In contrast, M. radiata infected with Omsk virus did not show any signs of clinical disease, and no virus could be isolated from tissues or blood at the end of the experiment. However, M. radiata infected with Russian spring-summer encephalitis (RSSE) developed clinical signs in the central nervous system; and, in one monkey, RSSE virus was isolated from the brain, and viral antigen was localized in neurons. Our data indicate that M. radiata is an excellent model to study human disease caused by KFD virus and could serve as a model for human disease caused by other, related strains of this group of viruses.

Rift Valley fever virus-induced encephalomyelitis and hepatitis in calves

Three calves (Nos. 1, 2 = 7 days old; No. 3 = 21 days old) were inoculated subcutaneously with virulent Rift Valley fever (RVF) virus. All calves became viremic and clinically ill, but the two 7-day-old calves were moribund and were euthanatized subsequently on post-inoculation day (PID) 3. Highest viral titers were measured in the serum, with lesser concentrations in the brain, heart, spleen, and liver of these animals. Viral antigens were detected by immunohistochemical analysis only in the livers, where positive staining was localized in coalescing foci of hepatocellular necrosis. The 21-day-old calf appeared to recover after viremia and pyrexia but became lethargic and ataxic and was euthanatized on PID 9. The calf was no longer viremic, and RVF virus was isolated only from the brain. Microscopic examination of the central nervous system revealed diffuse perivascular infiltrates of lymphocytes and macrophages, multifocal meningitis, and focal areas of neuronal necrosis and aggregates of macrophages, lymphocytes, and neutrophils throughout all regions of the brain and cervical spinal cord. There was positive immunohistochemical staining for viral antigens within the cytoplasm of neurons and glial cells throughout the central nervous system. Thus, RVF virus can cause encephalomyelitis in calves, and the specific virologic diagnosis can be made by immunohistochemical localization of viral antigens in formalin-fixed tissues.

Aerosol infection of rhesus macaques with Junin virus

The purpose of our work was to determine if aerosols of Junin virus can infect rhesus macaques and if the disease is the same as that produced by virus inoculated parenterally. The 6 macaques exposed to the virus by aerosol became acutely ill during the 3rd week after exposure, and all died. Three died by day 21, while the remainder died after 1 month. Junin virus was found primarily in visceral organs of those animals dying before 21 days after infection and in the central nervous system tissues from animals dying later. Histological changes were similar to those reported in rhesus monkeys after parenteral Junin viral infection. Gastrointestinal necrosis, however, was less severe in aerosol-infected animals and the associated septicemia was not seen. High levels of alpha interferon were detected by the 3rd day in all infected macaques. Experimental Argentine hemorrhagic fever induced by aerosol infection in rhesus macaques was similar to that seen after parenteral challenge and mimicked closely the clinical syndrome observed in humans.

Glucocorticoid hepatopathy: effect on receptor-mediated endocytosis of asialoglycoproteins

Histologic and electron microscopic examination of liver tissue from glucocorticoid-treated dogs (GT dogs) showed a markedly abnormal hepatocellular morphology which consisted of severe hepatocellular swelling, vacuolation, and peripheral displacement of subcellular organelles. The abnormal cell morphology was typical of that seen in clinical cases of canine Cushing's Syndrome. The hepatocyte isolation procedure used here works equally well for the preparation of viable hepatocytes from both normal and GT dogs even though GT dogs displayed a pronounced hepatopathy. Cell yields (10(9) cells from a 30-cm3 section of liver) are similar to those reported for rat hepatocytes using whole liver in situ perfusion and cell viability is routinely greater than 85%. The isolation procedure preserved the "abnormal" state or swollen morphology of the hepatocytes from GT dogs and thus can be used in pathophysiological studies of glucocorticoid-induced hepatopathy. The isolated hepatocytes were 3.2 times greater in cell volume than normal hepatocytes. We also observed over a 12.3-fold increase in alkaline phosphatase activity and the appearance in both the liver and the serum of GT dogs of the unique, corticosteroid alkaline phosphatase isozyme (CALP). In spite of the obvious abnormal liver morphology and elevated serum and liver alkaline phosphatase activities, the function of the hepatic cell surface carbohydrate binding protein, the Gal/GalNAc or asialoglycoprotein receptor, was not impaired. We found a trend of about a 1.5-fold increase in the initial rate of ligand uptake as well as 1.6-fold more receptors on GT dog hepatocytes compared to normal hepatocytes. The ligand binding affinity of these receptors, as well as the rate of ligand degradation, was identical in hepatocytes isolated from normal and diseased dogs. When intestinal alkaline phosphatase (IALP) is used as the ligand, approximately 25% was exocytosed intact following endocytosis. These results demonstrate that dogs with glucocorticoid hepatopathy possess a normally functioning Gal/GalNAc receptor. Furthermore, these data are consistent with the hypothesis that structurally related IALP and CALP isozymes may also be metabolically related through the Gal/GalNAc receptor endocytosis pathway. That is, a portion of the IALP normally endocytosed through the Gal/GalNAc receptor pathway in glucocorticoid-treated dogs may be recycled and converted (hyperglycosylated) to the abnormal serum CALP isozyme rather than being degraded.