Predictive value of ex vivo biodynamic imaging in determining response to chemotherapy in dogs with spontaneous non-Hodgkin's lymphomas: a preliminary study

Biodynamic imaging (BDI) is a novel phenotypic cancer profiling technology which optically characterizes changes in subcellular motion within living tumor tissue samples in response to ex vivo treatment with cancer chemotherapy drugs. The purpose of this preliminary study was to assess the ability of ex vivo BDI to predict in vivo clinical response to chemotherapy in ten dogs with naturally-occurring non-Hodgkin's lymphomas. Pre-treatment tumor biopsy samples were obtained from all dogs and treated ex vivo with doxorubicin (10 μM). BDI measured six dynamic biomarkers of subcellular motion from all biopsy samples at baseline and at regular intervals for 9 h following drug application. All dogs subsequently received doxorubicin to treat their lymphomas. Best overall response to and progression-free survival time following chemotherapy were recorded for all dogs. Receiver operating characteristic (ROC) curves were used to determine accuracy and identify possible cut-off values for the BDI-measured biomarkers which could accurately predict those dogs' cancers that would and would not respond to doxorubicin chemotherapy. One biomarker (designated 'MEM') showed 100% discriminative capability for predicting clinical response to doxorubicin (area under the ROC curve = 1.00, 95% CI 0.692-1.000), while other biomarkers also showed promising predictive capability. These preliminary findings suggest that ex vivo BDI can accurately predict treatment outcome following doxorubicin chemotherapy in a spontaneous animal cancer model, and is worthy of further investigation as a technology for personalized cancer medicine.

Three-dimensional holographic imaging of living tissue using a highly sensitive photorefractive polymer device

Photorefractive materials are dynamic holographic storage media that are highly sensitive to coherent light fields and relatively insensitive to a uniform light background. This can be exploited to effectively separate ballistic light from multiply-scattered light when imaging through turbid media. We developed a highly sensitive photorefractive polymer composite and incorporated it into a holographic optical coherence imaging system. This approach combines the advantages of coherence-domain imaging with the benefits of holography to form a high-speed wide-field imaging technique. By using coherence-gated holography, image-bearing ballistic light can be captured in real-time without computed tomography. We analyzed the implications of Fourier-domain and image-domain holography on the field of view and image resolution for a transmission recording geometry, and demonstrate holographic depth-resolved imaging of tumor spheroids with 12 microm axial and 10 microm lateral resolution, achieving a data acquisition speed of 8 x 10(5) voxels/s.

Time-dependent speckle in holographic optical coherence imaging and the health of tumor tissue

Holographic optical coherence imaging acquires en face images from successive depths inside scattering tissue. In a study of multicellular tumor spheroids the holographic features recorded from a fixed depth are observed to be time dependent, and they may be classified as variable or persistent. The ratio of variable to persistent features, as well as speckle correlation times, provides quantitative measures of the health of the tissue. Studies of rat osteogenic sarcoma tumor spheroids that have been subjected to metabolic and cross-polymerizing poisons provide quantitative differentiation among healthy, necrotic, and poisoned tissue. Organelle motility in healthy tissue appears as super-Brownian laser speckle, whereas chemically fixed tissue exhibits static speckle.

Endogenous generation of cyanide in neuronal tissue: involvement of a peroxidase system

In a study of the mechanism by which cyanide is produced in neural tissue, it was hypothesized that nerve cells generate cyanide in a manner similar to that in leukocytes. As in white blood cells, glycine addition enhanced cyanide production in rat pheochromocytoma cells. Because myeloperoxidase catalyses cyanide production in leukocytes, a selective myeloperoxidase inhibitor (aminobenzoic acid hydrazide) was tested and found to inhibit opiate agonist-induced cyanide production in pheochromocytoma cells and also in rat brain. In addition, hydrogen peroxide enhanced cyanide release in pheochromocytoma cells, further suggesting that the process is oxidative in nature. Sonicated rat pheochromocytoma cells did not generate cyanide in response to an agonist acting on surface receptors even though disrupted cells responded to glycine. The mitochondrial fraction from rat brain produced more cyanide in response to glycine than any other fraction. Thus glycine seems to act at an intracellular site to enhance cyanide production and the process seems to involve a peroxidase mechanism similar to that reported for white blood cells.

The macrophage in acute neural injury: changes in cell numbers over time and levels of cytokine production in mammalian central and peripheral nervous systems

We evaluated the timing and density of ED-1-positive macrophage accumulation (ED 1 is the primary antibody for the macrophage) and measured cytokine production by macrophages in standardized compression injuries to the spinal cord and sciatic nerves of individual rats 3, 5, 10 and 21 days post-injury. The actual site of mechanical damage to the nervous tissue, and a more distant site where Wallerian degeneration had occurred, were evaluated in both the peripheral nervous system (PNS) and the central nervous system (CNS) at these time points. The initial accumulation of activated macrophages was similar at both the central and peripheral sites of damage. Subsequently, macrophage densities at all locations studied were statistically significantly higher in the spinal cord than in the sciatic nerve at every time point but one. The peak concentrations of three cytokines, tumor necrosis factor α (TNF α), interleukin-1 (IL-1) and interleukin-6 (IL-6), appeared earlier and were statistically significantly higher in injured spinal cord than in injured sciatic nerve. We discuss the meaning of these data relative to the known differences in the reparative responses of the PNS and CNS to injury.

Porcine anterior cruciate ligament fibroblasts are similar to cells derived from the ligamentum teres, another non-healing intra-articular ligament

Porcine ligament fibroblasts were cultured from the anterior cruciate (ACL), medial collateral (MCL), and ligamentum teres (LT). There were no apparent differences in confluent cellular morphology among the ligament cell types as evaluated by phase contrast microscopy. The proliferation rate of MCL cells from 24-120 h was significantly higher (p < 0.05) than that of cells from either the LT or the ACL. MCL cells produced more collagen and less non-collagenous protein than the LT and ACL as determined by [3H]proline incorporation. This resulted in MCL cells producing a higher percentage (37%, p < 0.05) of collagen relative to total protein than either the ACL (28%) or the LT (32%). The MCL cells produced a significantly higher percentage (34.7%, p < 0.05) of type-III collagen relative to total type-I and III collagen than either the ACL (29.2%) or the LT (29.5%). The LT and MCL cells had similar and significantly greater coverage of in vitro wounds than the ACL. This study provides the first in vitro study of the LT and demonstrates that fibroblasts from the LT and ACL, two ligaments that heal poorly, have similar in vitro characteristics, with the exception of wound healing.

Identification of some components of basal lamina of avian ovarian follicle

Experiments were conducted to identify components of the basal lamina of the ovarian follicle. Pure and intact basal lamina was isolated from preovulatory follicles of the chicken ovary. Some components of the basal lamina could be solubilized with guanidine-HCl (designated Fraction 1) and remaining components with beta-mercaptomethanol containing guanidine-HCl (designated Fraction 2). With Western blot analysis, monoclonal and polyclonal antibodies raised against avian, mammalian, and human proteins recognized proteins in Fractions 1 and 2 of solubilized basal lamina. Thus, antibodies raised against extracellular matrix proteins, laminin, fibronectin, entactin or nidogen, tenascin, heparan sulfate proteoglycan, osteonectin, and Type IV collagen reacted positively with basal lamina proteins. Antibodies raised against the growth factors; epidermal growth factor; acidic and basic fibroblast growth factors; platelet-derived growth factor-AA; transforming growth factor-alpha; transforming growth factor-beta1, -beta2, -beta3, and -beta5; and insulin-like growth factor-I and -II cross-reacted with basal lamina proteins. Similarly, antibodies raised against insulin-like growth factor-binding proteins-2, -3, -4, -5, -6, and -7 cross-reacted with basal lamina proteins. In addition, antibodies generated against matrix metalloproteinases-1, -2, -3, -4, -8, -9, and -13 reacted positively with basal lamina proteins. Furthermore, antibodies produced against tissue inhibitors of matrix metalloproteinases-1, -2, -3, and -4 also reacted positively with basal lamina proteins. Moreover, interleukin-3, granulocyte macrophage-colony-stimulating factor, interferon-gamma antibodies recognized proteins in basal lamina. These observations are consistent with the view that the basal lamina of avian ovarian follicle is a store or source of biologically active molecules, namely growth factors, growth factor-binding proteins, cytokines, matrix metalloproteinases, and their tissue inhibitors. The growth factors could exert major effects on ovarian cell behavior and function, and the enzymes could participate in tissue remodeling during follicular development.

Effect of basal lamina on progesterone production by chicken granulosa cells in vitro--influence of follicular development

Experiments were conducted in vitro to study the regulation of progesterone production in chicken granulosa cells by homologous basal lamina isolated from preovulatory follicles of chicken ovary. The majority of components of the basal lamina (90-95% by weight) were solubilized with guanidine-HCl (and designated fraction 1); the remaining components were solubilized with beta-mercaptoethanol containing guanidine-HCl (and designated fraction 2). The ability of fraction 1 to regulate progesterone production in granulosa cells obtained from the largest (F(1), mature), third largest (F(3), growing), fifth to seventh largest (F(5-7), growing) follicles and a pool of small yellow follicles (SYF, immature) of chicken ovary was assessed. Granulosa cells isolated from SYF follicles were in the least differentiated (undifferentiated) and those obtained from F(1) follicles were in the most differentiated state. The ability of fraction 1 to regulate progesterone production by chicken granulosa cells was influenced both by the state of cell differentiation and the form of the matrix material (whether solid or liquid). When fraction 1 was added as liquid to the incubation mixture, it promoted progesterone production by granulosa cells at all stages of differentiation; however, it caused a greater relative increase in the amount of progesterone produced by undifferentiated (SYF) and differentiating (F(3)) granulosa cells than by differentiated (F(1)) ones. In the presence of the liquid-form of fraction 1, luteinizing hormone (LH) stimulated progesterone production in differentiated (F(1)) and differentiating (F(5-7)) granulosa cells. Similarly, follicle-stimulating hormone (FSH) stimulated progesterone production by differentiating (F(3)) and undifferentiated (SYF) granulosa cells in the presence of the liquid-form of fraction 1 protein. In culture wells that had been pre-coated with fraction 1 (solid-form), progesterone production by less differentiated (SYF, F(5-7)) granulosa cells was enhanced, whereas progesterone production by differentiated (F(1)) cells was reduced. The solid-form of fraction 1 augmented LH-stimulated progesterone production by less differentiated (F(5-7)) granulosa cells however, it attenuated LH-induced progesterone production in differentiated (F(1)) cells. FSH-promoted progesterone production in granulosa cells from immature follicles (SYF) was augmented by solid-form of fraction 1 whereas the effect of FSH on cells obtained from older follicle (F(3)) was suppressed by solid-form of fraction 1. In experiments in which gonadotropin action was attenuated by solid-form of fraction 1, the amount of progesterone produced in the presence of maximally inhibiting concentrations of fraction 1 protein was greater than control values (no fraction 1, no gonadotropin). These results show that basal lamina of the ovarian follicle can regulate progesterone production by granulosa cells. The data demonstrate that the interactions between the components of basal lamina and LH or FSH on granulosa cell function were dependent on the stage of follicular development and were influenced by the form of the matrix material. It is concluded that the basal lamina of the chicken ovarian follicle is biologically active and regulates granulosa cell function.

Basal lamina of avian ovarian follicle: influence on morphology of granulosa cells in-vitro

Experiments were conducted to determine the influence of basal lamina on the morphology of ovarian granulosa cells in vitro. Pure and intact basal lamina was isolated from the large preovulatory follicles of the chicken ovary and designated basal lamina of avian ovarian follicle (BLAOF). Examination of the isolated basal lamina with electron microscope revealed an ultrastructure that is similar to that of basal lamina in the intact ovarian follicle. Pieces of the intact basal lamina were attached to the bottom of 32 mm culture dishes (BLAOF-coated dishes) in which differentiated granulosa cells isolated from the largest preovulatory follicle or undifferentiated granulosa cells isolated from immature small yellow chicken ovarian follicles were cultured; uncoated dishes served as controls. Granulosa cells incubated on intact basal lamina assumed spherical shape, whereas granulosa cells incubated directly on plastic in control dishes became highly flattened. Interestingly, granulosa cells that attached to plastic close to BLAOF (in BLAOF-containing dishes) became rounded. The storage of BLAOF-coated culture dishes at 4 degrees C for 2 years had no apparent effect on its ability of the matrix material to induce changes in granulosa cell shape. Some components of the basal lamina could be solubilized with guanidine-HCl alone (fraction 1; 90-95% of total protein in BLAOF) with the remaining components solubilized with beta-mercaptoethanol containing guanidine-HCl (fraction 2; 5-10% of total protein in BLAOF). Differentiated and undifferentiated chicken granulosa cells became rounded when incubated in fraction 1-pre-coated wells; whereas those incubated directly on plastic in control wells were flattened. Similarly, when fraction 1 of solubilized basal lamina was added as liquid to incubation mixture, it caused both differentiated and undifferentiated granulosa cells to assume spherical shapes. The storage of fraction 1-coated culture dishes at 4 degrees C for 12 or more months had no apparent effect on its ability to influence granulosa cell shape. Fraction 1-induced changes in granulosa cell shape were similar to those observed for complete and intact basal lamina (BLAOF). These findings demonstrate that intact homologous basal lamina (BLAOF) or its solubilized (fluidized) form can induce normal (in vivo) morphology in granulosa cells. It is suggested that BLAOF or its solubilized form can be used to culture cells in experiments designed to examine the influence of the natural basal lamina microenvironment on cellular behavior and function.

Methodological aspects of measuring amino acid uptake in studies with porcine jejunal brush border membrane vesicles

With L-glutamine, as a representative amino acid this study was undertaken to examine the effects of substrate concentrations on initial and equilibrium amino acid uptake and intravesicular volume determined with porcine jejunal brush border membrane vesicles prepared by Mg2+-aggregation and differential centrifugation. Transport measurements (24 degrees C) were conducted by the rapid filtration manual procedure. Glutamine uptake was shown to occur into an osmotically-active space ranging between 1.09-1.58 microl/mg protein with little non-specific membrane binding. At different concentrations (in parentheses), the duration of initial glutamine uptake in both Na+ gradient and Na+-free conditions was 10 s (0.01 mM), 15 s (0.17 mM), and 20 s (1.9 and 9.4 mM), respectively. Substrate concentrations affected the duration of initial uptake, with lower substrate concentrations giving shorter duration for initial amino acid uptake. At different substrate concentrations (in parentheses), the time required to reach equilibrium glutamine uptake was 5 min (0.01 mM), 10 min (0.17 mM), and 60 min (1.9 and 9.4 mM), respectively. Thus, substrate concentrations also affected the time required to reach equilibrium uptake. The higher the substrate concentration, the longer the incubation time needed to reach equilibrium amino acid uptake. At the glutamine concentrations of 0.01, 0.17, 1.9, and 9.4 mM, the average intravesicular volume was estimated to be 1.58+/-0.21, 1.09+/-0.28, 1.24+/-0.18, and 1.36+/-0.21 microl/mg protein, respectively. Substrate concentrations had no effect (p>0.05) on the intravesicular volume of membrane vesicles. In conclusion, in the experiments on amino acid transport kinetics measured with the rapid filtration manual procedure, the incubation time used for measuring the initial uptake rate should be determined from the time course experiments conducted at the lowest substrate concentration used, whereas the intravesicular volume can be obtained from equilibrium uptake measured at any substrate concentrations.

Omega-3 fatty acids enhance ligament fibroblast collagen formation in association with changes in interleukin-6 production

Altering dietary ratios of n-3 and n-6 polyunsaturated fatty acids (PUFA) represents an effective nonpharmaceutical means to improve systemic inflammatory conditions. An effect of PUFA on cartilage and bone formation has been demonstrated, and the purpose of this study was to determine the potential of PUFA modulation to improve ligament healing. The effects of n-3 and n-6 PUFA on the in vitro healing response of medial collateral ligament (MCL) fibroblasts were investigated by studying the cellular coverage of an in vitro wound and the production of collagen, PGE2, IL-1, IL-6, and TNF. Cells were exposed to a bovine serum albumin (BSA) control or either eicosapentaenoic acid (EPA, 20:5n-3) or arachidonic acid (AA, 20:4n-6) in the form of soaps loaded onto BSA for 4 days and wounded on Day 5. AA and EPA improved the healing of an in vitro wound over 72 hr. EPA increased collagen synthesis and the overall percentage of collagen produced, but AA reduced collagen production and total protein. PGE2 production was increased in the AA-treated group and decreased in the EPA-treated group, but was not affected by wounding. IL-1 was not produced at the time point evaluated, but TNF and IL-6 were both produced, and their levels varied relative to the PUFA or wounding treatment. There was a significant linear correlation (r2 = 0.57, P = 0.0045) between IL-6 level and collagen production. These results demonstrate that n-3 PUFA (represented by EPA in this study) positively affect the healing characteristics of MCL cells and therefore may represent a possible noninvasive treatment to improve ligament healing. Additionally, these results show that MCL fibroblasts produce PGE2, IL-6, and TNF and that IL-6 production is related to MCL collagen synthesis.

Effect of age, breed and dietary omega-6 (n-6): omega-3 (n-3) fatty acid ratio on immune function, eicosanoid production, and lipid peroxidation in young and aged dogs

The focus of this study was to examine the influence of age and diet on various parameters of immune function in young and old Fox Terriers and Labrador Retrievers. Eighteen young and old dogs were utilized for this study. Young and old dogs were fed a basal diet containing an (n-6):(n-3) ratio of 25:1 for sixty days (Phase I). Half of the dogs were then switched to a diet with an (n-6):(n-3) ratio of 5:1, and all were maintained on their respective diets for an additional sixty days (Phase II). Results from these studies revealed an age-associated decline in several immune parameters measured. Both these breeds demonstrated a reduction in sheep red blood cell titers, as well as in their ability to respond to different mitogens. Interestingly, this decline was greater in Fox Terriers, suggesting a decrease in cellular proliferative capacity in lymphocytes isolated from the larger breed. Neither cytokine production or DTH response was affected by age. Diet and breed interactions resulted in a significant increase in T- and B-cell mitogen responsiveness. In contrast, supplementation with n-3 fatty acids did not affect IL-1, IL-6 or TNF-alpha production. Supplementation with n-3 fatty acids resulted in increased PGE3 production from peritoneal macrophages but had no effect on PGE2 production from peripheral blood mononuclear cells or peritoneal macrophages. The n-3 fatty acid supplementation did not influence alpha-tocopherol status although older dogs had significantly lower serum alpha-tocopherol concentrations. Oxidative status of these dogs was assessed by serum levels of malondialdehyde (MDA) and 4-hydroxynonenal (4-HNE). Feeding an n-3-enriched diet did not affect 4-HNE levels but significantly decreased MDA levels in old dogs. In summary, this study indicates that feeding a diet containing an (n-6):(n-3) fatty acid ratio of 5:1 had a positive, rather than a negative, effect on the immune response of young or geriatric dogs.

Select 3-hydroxy-3-methylglutaryl-coenzyme A reductase inhibitors vary in their ability to reduce egg yolk cholesterol levels in laying hens through alteration of hepatic cholesterol biosynthesis and plasma VLDL composition

The inability to markedly attenuate cholesterol levels in chicken eggs has led to speculation that cholesterol is essential for yolk formation and that egg production would cease when yolk cholesterol deposition was inadequate for embryonic survival. However, this critical level hypothesis remains unproven. Here, we determine the relative responsiveness of laying hens to three select inhibitors of 3-hydroxy-3-methylglutaryl-coenzyme A reductase (HMGR), the rate-limiting enzyme of cholesterol biosynthesis. A control diet, either alone or supplemented with one of two dietary levels (0.03 or 0.06%) of atorvastatin, lovastatin, or simvastatin, was fed to White Leghorn hens for 5 wk. Liver cholesterol concentrations (mg/g tissue) were decreased (P </= 0.05) by each HMGR inhibitor; however, total liver cholesterol (mg) did not differ among treatments. Microsomal hepatic HMGR activities were increased one- to twofold in all HMGR inhibitor-treated groups, while HMGR mRNA levels were unaffected. Diameters of plasma VLDL particles, the main cholesterol-carrying yolk precursor macromolecules, were reduced (P </= 0.05) only in hens fed 0.06% atorvastatin, and the particles contained 38% less total cholesterol (P </= 0.05) than controls. Plasma total cholesterol concentrations were lowered (P </= 0.05) by both doses of atorvastatin (-56, -63%) and simvastatin (-36,-45%). Egg cholesterol contents were maximally reduced by 46% (P </= 0.05), 7% (P > 0.05), and 22% (P </= 0.05) in hens fed the 0.06% level of atorvastatin, lovastatin, and simvastatin, respectively, while overall egg production [-19% (P </= 0.05), +4% (P > 0.05), and -3% (P > 0.05)], was much less affected. We concluded that cholesterol per se may not be an obligatory component for yolk formation in chickens and, as such, may be amenable to further pharmacological manipulation

Push-pull sorbent-based pheresis treatment in an experimental canine endotoxemia model: preliminary report

The Biologic-DTPF System (DTPF), an extracorporeal blood treatment device with potential to treat sepsis, was tested in a preliminary study using a canine endotoxemia model. Six dogs were used and they formed four treatment groups, as control group (n=1) and three groups based on the type of sorbent present in the plasma filter (PF) system: sham treatment with no sorbent (n=1), charcoal as sorbent (n=2), and charcoal/silica as sorbent ("silica" group, n=2). Cardiodynamic data were recorded before treatment and every 30 minutes, and blood samples were collected to determine blood chemistry and to detect the levels of endotoxin and selected plasma cytokines: interleukin-1 (IL-1), interleukin-6 (IL-6), and tumor necrosis factor (TNF). The dogs were given Escherichia coli endotoxin (2 mg/kg) as an intravenous drip (extended over a period of 30 minutes). Thirty minutes after the end of infusion all animals except the control were treated with the DTPF system for four hours. To determine the effect of treatment, data collected at one hour from the initiation of treatment until the end of treatment were compared between control and treated dogs. The endotoxin levels in the control dog were higher (P < 0.05) than other groups. The control dog had lower levels of TNF than other groups. The control dog had similar levels of IL-1 (P > 0.05) and higher levels (P < 0.05) at 4 hours into treatment compared to other groups. The control dog had similar levels of IL-6 as other groups (P > 0.05). In the control dog, the mean arterial pressure (MAP) fell and then remained low but stable at 1-4 hours. The charcoal group had lower MAP than the control dog at 1-4 hours (P < 0.05). The silica group had higher MAP levels similar to the control dog. After treatment, the control dog had higher (P < 0.05) values of hematocrit, hemoglobin, calcium, potassium, and albumin compared to the treated groups. As expected for a system removing plasma during sepsis, the DTPF System had some adverse effects on the physiologic status of the dogs, especially when loaded with charcoal sorbent only. The findings of the present study suggest that the filters are capable of eliminating endotoxin and there is some evidence of cytokine removal. Although the charcoal dogs did poorly, addition of silica to the sorbent offset any negative effects. Further work is underway to improve the efficiency of the system, primarily to enhance the capacity of the sorbents for cytokines. A more realistic canine sepsis model with mortality after several days (the Escherichia coli- infected intraperitoneal clot) will also be considered in future studies.

Indium-111-DTPA-folate as a potential folate-receptor-targeted radiopharmaceutical

Indium-111-labeled diethylenetriamine pentaacetic acid (DTPA)-folate was evaluated as a radiopharmaceutical for targeting tumor-associated folate receptors.

METHODS

Athymic mice were subcutaneously inoculated with approximately 1.8 x 10(6) folate receptor-positive KB (human nasopharyngeal carcinoma) cells, yielding 0.2- to 0.6-g tumors in 15 days, at which time (111)In-DTPA-folate, (111)In-DTPA or (111)In-citrate was administered by intravenous injection.

RESULTS

The (111)In-DTPA-folate conjugate afforded marked tumor-specific (111)In deposition in vivo using this mouse model. The involvement of the folate receptor in mediating tumor uptake of (111)In-DTPA-folate was demonstrated by the blocking of tumor uptake by coadministration of free folic acid (intravenous). The (111)In-DTPA-folate also shows folate receptor-mediated uptake and retention in the kidneys, presumably reflecting radiotracer binding to folate receptors of the proximal tubules. In control experiments, the (111)In-citrate radiopharmaceutical precursor was also shown to afford significant tumor uptake of (111)In, but with much poorer tumor-to-background tissue contrast than that obtained with (111)In-DTPA-folate. Unconjugated (111)In-DTPA showed no tumor affinity.

CONCLUSION

Indium-111-DTPA-folate appears suitable as a radiopharmaceutical for targeting tumor-associated folate receptors.

Linoleate impairs collagen synthesis in primary cultures of avian chondrocytes

The effects of supplemental fatty acids, vitamin E (VIT E), and iron-induced oxidative stress on collagen synthesis, cellular injury, and lipid peroxidation were evaluated in primary cultures of avian epiphyseal chondrocytes. The treatments included oleic and linoleic acids (O or 50 microM) complexed with BSA and dl-alpha-tocopheryl acetate (VIT E at 0 or 100 microM). After 14 days of preculture, the chondrocytes were enriched with fatty acids for 8 days then cultured with VIT E for 2 days. The chondrocytes were then treated with ferrous sulfate (O or 20 microM) for 24 hr to induce oxidative stress. Collagen synthesis was the lowest and the activity of lactate dehydrogenase (LDH) was the highest in chondrocyte cultures treated with 50 microM linoleic acid and 0 VIT E. In contrast, VIT E supplemented at 100 microM partially restored collagen synthesis in the chondrocytes enriched with linoleic acid and lowered LDH activity in the media. The iron oxidative inducer significantly increased the values of thiobarbituric acid-reactive substances (TBARS) in the culture medium. The data showed that linoleic acid impaired chondrocyte cell function and caused cellular injury but that VIT E reversed these effects. Results from a previous study demonstrated that VIT E stimulated bone formation in chicks fed unsaturated fat, and the present findings in cultures of epiphyseal chondrocytes suggest that VIT E is important for chondrocyte function in the presence of polyunsaturated fatty acids. VIT E appears to be beneficial for growth cartilage biology and in optimizing bone growth.

Dietary polyunsaturated fatty acids modulate responses of pigs to Mycoplasma hyopneumoniae infection

Polyunsaturated fatty acids (PUFA) are immunomodulators, but few studies have examined how these dietary components influence infectious respiratory disease. Groups of nine pigs were fed casein and corn starch-based diets containing 10.5 g/100 g corn oil (CO), linseed oil (LO), menhaden oil (MO), linseed + corn oil (LC, 1:1) and menhaden + corn oil (MC, 1:1). As a methodological control, one group of pigs (n = 15) was fed a commercial ration (control diet; C). Pigs inoculated intratracheally with Mycoplasma hyopneumoniae after 4 wk of consuming the diets were killed 3 wk later. Gross lung lesions in MO-fed pigs were less (P < 0.05) than those in LC- and MC-fed pigs. Pigs fed MO had less peribronchial inflammation (P < 0.05) than all other groups. Gross lung lesions correlated negatively with basal in vitro alveolar macrophage tumor necrosis factor (TNF) production in pigs fed diets that contained negligible levels of (n-3) PUFA (C and CO). Basal macrophage TNF production did not correlate with lung lesion scores for diets containing more (n-3) PUFA than C or CO (LO, MO, LC and MC). For pigs fed the LO, MO, LC and MC diets, mean gross lung lesions increased as the mean ratio of (n-3):(n-6) PUFA in alveolar macrophage lipids decreased. Serum levels of alpha1 acid glycoprotein (AGP) were less (P < 0.05) in pigs fed MO, and there was a rise in mean lung lesions scores for each PUFA-fed group as mean AGP levels increased. These results indicate that dietary PUFA can affect disease pathogenesis and that the (n-3):(n-6) PUFA ratio may modulate the host response.

Early ultrastructural lesions of diphenylamine-induced renal papillary necrosis in Syrian hamsters

The ultrastructural lesions of diphenylamine-induced renal papillary necrosis in Syrian hamsters were characterized by transmission electron microscopy. Twenty-four male Syrian hamsters were orally administered 600 mg diphenylamine/kg body weight as a single dose. At 30 minutes and at 1, 2, 4, 8, 16 and 24 hours after administration of diphenylamine, three hamsters were anesthetized with pentobarbital, perfused via the left ventricle with half-strength KARNOVSKY's fixative, and the renal papilla and outer medulla collected. Three hamsters administered 0.5 ml peanut oil/kg body weight (vehicle controls) were anesthetized at 24 hours, perfused, and the renal papilla and outer medulla collected. Initial ultrastructural lesions were observed in the endothelial cells of the ascending vasa recta in the proximal portion of the renal papilla at 1 hour after diphenylamine administration. The endothelial cell basal plasma membrane was elevated from the basal lamina, forming large subendothelial vacuoles. Alterations in inner medullary interstitial cells, endothelial cells of the descending vasa recta, and the epithelial cells of the thin limbs of Henle and the medullary collecting tubules were observed subsequent to the lesion in the ascending vasa recta. It was concluded that the endothelial cell of the ascending vasa recta is the target cell in diphenylamine-induced renal papillary necrosis in Syrian hamsters.

Ultrastructure and cytochemical staining characteristics of canine natural killer cells

BACKGROUND

The purpose of this work was to describe the ultrastructure and cytochemical staining characteristics of canine peripheral blood lymphocytes with natural killer (NK) cell activity, with comparison made to non-NK lymphocytes.

METHODS

Canine lymphocyte populations evaluated for ultrastructure, cytochemical staining, and NK function (by 51chromium release assay) included: peripheral blood lymphocytes; lymphocytes from band 1 (NK-enriched), band 2, and the pellet of a 45/50% percoll gradient; lymphocytes from the supernatant fluid (non-conjugated lymphocytes) and pellet (lymphocytes conjugated to tumor cell targets) of a 17% percoll gradient; and null (CD4-CD8-) and CD4-CD8+ lymphocytes.

RESULTS

NK activity was concentrated in band 1 lymphocytes of the 45/50% percoll gradient with further enhancement of activity occurring in sorted null cells. Canine NK cells were 5.5 to 6.5 microns in diameter with a reniform (kidney bean shape) nucleus, and electron-dense cytoplasmic granules. NK cells (percoll band 1 cells and null cells) had larger cell and nuclear area, and less round nuclei when compared to non-NK lymphocytes. The overall cytochemical staining (chloracetate esterase, peroxidase, sudan black B, naphthyl acetate esterase, naphthyl butyrate esterase periodic acid-Schiff stain, and acid phosphatase with and without tartrate) pattern was similar in all the lymphocyte populations evaluated.

CONCLUSIONS

This work confirms the usefulness of a 45/50% percoll gradient in obtaining a NK-enriched fraction of canine lymphocytes, and shows further enhancement of NK activity in sorted CD4- CD8- cells. The ultrastructure of canine NK cells is similar to that reported for human NK cells, but is different from that of other canine peripheral blood lymphocytes. Standard cytochemical staining does not discriminate canine NK cells from other lymphocytes.

Dietary polyunsaturated fatty acid effects on immune cells of the porcine lung

The effects of various dietary polyunsaturated fatty acids (PUFAs) on the function of immune cells of the porcine lung was studied. Groups of six pigs were fed diets containing 10.5% corn oil [CO; enriched in linoleic acid (18:2, n-6)], linseed oil (LO; enriched in alpha-linolenic acid (18:3, n-3)], menhaden oil (MO; enriched in eicosapentaenoic (20:5; n-3) and docosahexaenoic (22:6; n-3) acids], linseed + corn oil (1:1; LC), and menhaden + corn oil (1:1; MC) for 28-30 days. Basal levels of alveolar macrophage (m phi) tumor necrosis factor-alpha (TNF-alpha) production were higher (P < .05) for LC- and MC-fed pigs than for CO- and LO-fed pigs. Lipopolysaccharide (LPS)-stimulated LC and MC m phi s produced more TNF than m phi s from pigs fed CO, LO, and MO diets. Macrophages from pigs receiving the CO and LC diets had higher (P < .05) levels of leucine aminopeptidase than m phi s from the other dietary groups. Lipopolysaccharide did not increase m phi nitrite production over basal levels except in the MO diet group. However, LPS-stimulated m phi s from the CO, MO, and LC dietary groups produced more nitrite than m phi s from MC-fed pigs. Alveolar lymphocytes from pigs receiving the MC diet produced more T cell growth factors than LO and MO m phi s. Alveolar m phi s from the different dietary groups did not differ in their capacity for non-immune-mediated phagocytosis of fluorescent latex beads. These results indicate that dietary PUFAs can modulate some functions of porcine alveolar immune cells and that this may prove significant for host response to respiratory disease agents.

Endocytosis of folate-protein conjugates: ultrastructural localization in KB cells

It has been demonstrated that proteins covalently conjugated to folic acid may be taken up by cells via endocytosis after binding to a folate binding protein (FBP) in the cell membrane. The proteins taken up in this manner remain catalytically active and they may modify physiological processes occurring in the cytosol. Confocal fluorescence microscopy of KB cells incubated with FITC-bovine serum albumin-folic acid conjugates showed that after uptake, the conjugates resided in large vesicular structures. The purpose of the present study was to determine the subcellular localization of protein-folic acid conjugates in KB cells using folic acid-bovine serum albumin-colloidal gold (F-BSA-CG) as a tracer. F-BSA-CG conjugates were taken up via uncoated pits or caveolae, and resided primarily in multivesicular bodies (MVBs) and other tubular endosomes at early time points (15-60 min). At later time points (6 hours), conjugates were still contained in MVBs but some were also found in secondary lysosomes or free in the cytoplasm. Coincubation of KB cells with transferrin-colloidal gold (TF-CG) and F-BSA-CG resulted in colocalization of TF-CG and F-BSA-CG within endosomal elements at times later than 15 minutes, indicating that the caveolae-mediated F-BSA-CG endocytic pathway converged with a pathway utilized by clathrin-coated pits.

Indomethacin-induced gastrointestinal ulcers in rats: effects of dietary fatty acids and endotoxin

The purpose of this study was to determine how dietary n-3 and n-6 polyunsaturated fatty acids (PUFA) affected the gastrointestinal response to lipopolysaccharide (LPS) and indomethacin (INDO) in the rat. Rats were fed diets containing 12.5% linseed oil (LO-enriched in short-chain n-3 PUFA) or corn oil (CO-enriched in n-6 PUFA). After 30 days on the diets, rats were given one of three treatments 1:10 mg/kg O55:B5 Escherichia coli LPS intraperitoneally (i.p.), 2:25 mg/kg INDO subcutaneously (s.c.), 3: a combination of 10 mg/kg i.p. LPS and 25 mg/kg (s.c.) INDO given 30 min before LPS. 20 h after challenge, rats were given an intravenous injection of Monastral Blue B to stain ulcer areas in the gastrointestinal tract. Lipopolysaccharide did not result in any Monastral Blue B vascular leakage in the gastrointestinal tract. Rats on the LO diet had significantly increased stomach and intestinal ulcers compared to CO fed rats. When rats were challenged with LPS and INDO, the LPS almost completely eliminated small intestinal ulcers, but enhanced ulcer development in the stomach.

Measurement of NK activity in effector cells purified from canine peripheral lymphocytes

Natural killer (NK) cells spontaneously lyse a variety of tumor cells in vitro, and are believed to play an important role in host resistance to tumor growth and metastasis in vivo. As part of our work in comparative oncology, we have designed and validated a canine NK cell assay. Of several lymphocyte isolation techniques evaluated, sedimentation of whole blood through a two-step Ficoll/Hypaque gradient (sp. gr. 1.066/1.119) followed by plastic adherence of monocytes resulted in the most pure lymphocyte population (> 95% lymphocytes). Of four cell lines evaluated as targets in the NK assay, a canine thyroid adenocarcinoma (CTAC) cell line was determined to be most sensitive, and a lymphoblastoid (CT45-S) cell line was determined to be most resistant to NK lysis. A 15 h effector-target incubation period using these targets resulted in reproducible measurement of cell specific lytic activity. Passage of canine lymphocytes through nylon wool columns did not result in a significant increase in NK activity. A final sedimentation of purified lymphocytes through a 45/50% Percoll gradient concentrated NK activity into a single band of lymphocytes. Lymphocytes forming conjugates with CTAC target cells were 5.5-6.5 microns in diameter, and were characterized by a reniform nucleus and varying numbers of electron-dense cytoplasmic granules.

Early sequential ultrastructural renal alterations induced by 2-bromoethylamine hydrobromide in the Swiss ICR mouse

Thirty-two male Swiss ICR mice were injected intraperitoneally with 300 mg 2-bromoethylamine hydrobromide/kg body weight, anesthetized, and perfused with glutaraldehyde-paraformaldehyde solution at 5, 15, 30, 60, 90, 120, 150, and 180 minutes after treatment. Eight control mice were injected intraperitoneally with sterile diluent, and one was perfused at each of the same time periods as the treated mice. Proximal tubule epithelial alterations progressed over time from increased secondary lysosome and myeloid body formation to cellular and mitochondrial swelling and eventually cell necrosis. The glomerular, peritubular, and vasa recta capillaries had endothelial cell swelling and desquamation and platelet aggregation. Bromoethylamine nephrotoxicosis in the male Swiss ICR mouse is an ischemic necrosis of the proximal tubules and papilla initiated by endothelial cell damage and makes an excellent model of chemically induced damage to endothelial cells and tubular necrosis.

Ultrastructural changes in articular cartilages of immature beagle dogs dosed with difloxacin, a fluoroquinolone

The ultrastructural features of quinolone-induced arthropathy were studied in the humeral and femoral heads of nine skeletally immature Beagle dogs (3 months old) that were dosed orally with difloxacin at 300 mg/kg body weight and euthanatized 24, 36, or 48 hours later in groups of three. Three age-matched dogs were given a placebo and euthanatized after 48 hours. Mitochondria in chondrocytes had significantly greater cross-sectional areas (P less than 0.05) in electron micrographs from dogs euthanatized after 48 hours of treatment than did those in other groups. There was also a significantly greater percentage of chondrocytes with swollen mitochondria in treated dogs than in the controls (P less than 0.05). These changes preceded the necrosis observed in some chondrocytes in the dogs of the 48-hour group. Disruption of extracellular matrix was first observed in the pericellular matrix of necrotic chondrocytes, indicating that this change was secondary to the changes in chondrocytes. Fissures within cartilages apparently resulted from the loss of the normal association of proteoglycans with collagen fibrils.

Experimental renal papillary necrosis in the Mongolian gerbil (Meriones unguiculatus)

Sequential light microscopic and ultrastructural examination of kidneys from male and light microscopic examination of female Mongolian gerbils given 250 mg 2-bromoethylamine hydrobromide (BEA)/kg body weight ip were performed. In addition, male Mongolian gerbils were treated with both BEA and ip injections of either water, dimethyl sulfoxide, piperonyl butoxide, or reserpine. Light microscopic renal lesions in male Mongolian gerbils progressed from congestion of the vasa recta of the proximal inner medulla at 6 hr post-treatment to total renal papillary necrosis (RPN) at 24 hr post-treatment. There was no sex difference in sensitivity to BEA. Ultrastructural alterations in male gerbils were restricted to the vasa recta. Vascular lesions of endothelial swelling and pericapillary edema in the vasa recta of the proximal inner medulla was observed 2 hr post-treatment and progressed to occlusion by platelets adherent to exposed basement membranes at 6 hr post-treatment. Diuresis induced by injections of saline and injections of dimethyl sulfoxide or piperonyl butoxide did not affect the development of BEA-induced RPN. Reserpine slowed the development of BEA-induced RPN by its vasodilatory effect on the renal vasculature, not by blocking the endothelial toxicity of BEA. RPN induced by BEA in the Mongolian gerbil is apparently an ischemic necrosis of the inner medulla that develops secondary to endothelial damage of the vasa recta.

Endothelial superoxide production in the isolated rat heart during early reperfusion after ischemia. A histochemical study

This paper describes a histochemical study of superoxide generation in buffer-perfused, isolated rat hearts during the first 2 minutes of reperfusion after 60 minutes of warm ischemia. Superoxide radical production was demonstrated by a modification of Karnovsky's manganese/diaminobenzidine technique, in which superoxide oxidizes Mn++ to Mn ions, which in turn oxidize diaminobenzidine to form amber, osmiophilic polymers, observable by light or electron microscopy. Isolated hearts were rendered ischemic, reperfused with oxygen equilibrated buffer containing Mn++ and diaminobenzidine, fixed by perfusion with Trump's solution, and processed for light and electron microscopy. The method consistently demonstrated evidence of superoxide generation near the luminal surfaces of arterial, capillary, and venular endothelial cells during the first 2 minutes of reoxygenation after ischemia. The histochemical reaction was absent or markedly reduced in non-manganese-treated or nonischemic hearts, as well as in hearts perfused with calcium-free or oxygen-free buffers. The histochemical differences were statistically significant on quantitative morphometric analysis. These results provide direct, visual evidence of the existence and endothelial localization of a burst of superoxide radicals in intact, postischemic myocardium and suggest the pathophysiologic importance of calcium-dependent endothelial cell activation in the initiation of reperfusion injury.

Endothelial superoxide production in buffer perfused rat lungs, demonstrated by a new histochemical technique

This paper describes a new approach to the histochemical demonstration of superoxide generation by pulmonary vascular endothelial cells using a supravital high manganese/diamine technique, in which nascent superoxide radicals induce formation of amber, osmiophilic polymers of diaminobenzidine (DAB), detectable by light or electron microscopy. Superoxide oxidizes Mn2+ ions to the Mn3+ valence state. In turn trivalent manganese readily initiates formation of the polymerized DAB reaction product. Isolated rat lungs were perfused in situ with bloodless, buffered high manganese/DAB salt solution via the pulmonary artery. The aortic root was ligated to minimize outflow from the left heart, so that perfusate shunted across pulmonary capillary endothelium, to fill the alveolar spaces and drain via the trachea. Lungs were perfused for 3 min with oxygen equilibrated buffer, with or without 60 min prior warm anoxia, induced by initial perfusion with argon sparged buffer. After aldehyde fixation and tissue processing DAB reaction product was detected on the inner, luminal surface of the vascular endothelium by both light and electron microscopy. Bronchi and epithelial cells never stained positively. The histochemical reaction was absent or markedly reduced in non-manganese treated or superoxide dismutase treated lungs, as well as in lungs perfused with calcium free buffer. The histochemical reaction was not prevented by the xanthine oxidase inhibitors allopurinol or methylene blue. The high manganese/diamine technique provides direct visual evidence of a calcium dependent mechanism by which pulmonary vascular endothelial cells can generate superoxide radicals.

The effect of dietary n-3 and n-6 fatty acids on tumor necrosis factor-alpha production and leucine aminopeptidase levels in rat peritoneal macrophages

The purpose of this study was to determine the effect of dietary n-3 and n-6 fatty acids on tumor necrosis factor-alpha (TNF-alpha) production and macrophage (MO) activation state. Rats were fed diets containing 12.5% linseed oil (LO) or corn oil (CO) that are high in n-3 and n-6 fatty acids respectively. The LO diet resulted in a significant increase in basal and endotoxin (LPS)-induced levels of TNF-alpha from resident MO cultured in vitro. There was no difference between the diets in LPS-induced TNF-alpha production by complete Freund's adjuvant (CFA) elicited macrophages. Variable responses were also observed between LO and CO MO in response to prostaglandin E2, indomethacin (INDO), and the prostaglandin E receptor antagonist SC-19220. This may indicate differences in signal transducing secondary messengers due to different activation states, receptor expression or ligand binding. Fluorescence due to leucine aminopeptidase (LAP) staining was determined by flow cytometry. Resident LO MO had a 15% increase in LAP fluorescence compared to CO MO. In CFA-elicited MO, the CO MO had a 43% increase in fluorescence compared to LO MO. Resident LO MO increased in LAP fluorescence by 35% to the activated state whereas resident CO MO increased in LAP fluorescence by 93%. The smaller window of activation for the LO MO may explain some of the antiinflammatory properties of dietary n-3 fatty acids.

Cytochemical studies of hydrogen peroxide generation in postischemic hepatocytes

Reoxygenation injury that occurs when blood circulation is restored to previously ischemic tissues is currently discussed as a pathophysiological entity distinct from the primary anoxic injury that develops during ischemia per se. To test the hypothesis that reoxygenation injury in hepatocytes is caused by a postischemic burst of reactive oxygen species (ROS), including superoxide radicals, O2-., and hydrogen peroxide, H2O2, we performed a cytochemical study exploiting the peroxidase activity within peroxisomes as a sensitive ultrastructural detector of intracellular H2O2 generation. The osmiophilic polymer formed when tissue peroxidase is incubated with 3,3'-diaminobenzidine (DAB) and H2O2 was used as a marker for endogenous H2O2 in rat liver slices in short-term organ culture subjected to a cycle of 60-min ischemic anoxia and 30-min reoxygenation in the presence of DAB without exogenous H2O2. Peroxisomal reaction product was quantitatively evaluated in transmission electron micrographs of systematically sampled hepatocytes. Mean densities of positive peroxisomes per 1,000 micron2 (+/- SE) in liver slices subjected to various treatments were as follows: continuous anoxia (negative control) 0 +/- 0; normoxia + exogenous H2O2 (positive control) 45 +/- 12; normoxia only 26 +/- 2; ischemia-reoxygenation 13 +/- 6; ischemia-reoxygenation + xanthine oxidase inhibitor, oxypurinol 5 +/- 3; ischemia-reoxygenation + peroxidase inhibitor, aminotriazole 7 +/- 3. Endogenous H2O2 can be detected in hepatocytes by electron microscopic cytochemistry and may in part derive from xanthine oxidase, but it is not substantially increased in the postischemic state. We conclude that hepatocytes do not exhibit a postischemic burst of reactive oxygen species that could cause reoxygenation injury.

Cyanide-induced neurotoxicity: calcium mediation of morphological changes in neuronal cells

Calcium channel blockade decreases the elevation of brain calcium as well as the tremors produced by cyanide in mice. To determine if cyanide-induced morphological changes could also be inhibited by calcium channel blockade, the effect of diltiazem was studied in cultured rat pheochromocytoma (PC12) cells, a neuronal model. Incubation with KCN (1 to 10 mM for 1 to 2 hr) caused depletion of secretory granules, alignment of remaining granules along the plasma membrane, and mitochondrial swelling. All these effects were inhibited by pretreatment with 0.01 mM diltiazem. Scanning electron microscopy revealed that cyanide (1 to 10 mM for 1 to 2 hr) produced loss of microvilli and bleb formation in PC12 cells. These changes were partially inhibited by preincubation with 0.01 mM diltiazem. Incubation of cells with 10 mM cyanide increased release of lactic dehydrogenase (LDH) into the culture media at 60 and 120 min. A decrease in cell viability, as determined by trypan blue dye exclusion, paralleled the release of LDH. At 120 min of cyanide incubation, 24% of the cells excluded dye. Both the release of LDH and decreased cell viability were attenuated by pretreatment with diltiazem. The results indicate that the influx of extracellular calcium is an important factor mediating cyanide-induced morphologic changes in neuronal cells.

Lectin binding to small intestinal goblet cells of newborn, suckling, and weaned pigs

Lectin binding of small intestinal goblet cells was examined in newborn, suckling, and weaned pigs. Sections of duodenum, proximal portion of the jejunum, distal portion of the jejunum, and ileum were embedded in a hydrophilic acrylic resin and treated with each of the following lectins: Canavalia ensiformis, Ricinus communis I, Glycine max, Ulex europaeus I, and Triticum vulgaris. Percentages of goblet cells binding each lectin were calculated within intestinal regions. Differences in lectin-binding affinity were detected among pigs of various ages and among various intestinal regions within pig age groups.

Naturally occurring mucocutaneous histoplasmosis in a rabbit

Mucocutaneous histoplasmosis was diagnosed in a pet rabbit. A mass protruding through the anal opening was histologically composed of a densely cellular infiltrate of macrophages which expanded the anorectal submucosa. Macrophages contained abundant yeast forms of fungi morphologically consistent with Histoplasma capsulatum. Infection appeared to be localized. Histoplasmosis should be considered in the differential diagnosis of granulomatous inflammatory disease in the rabbit.

Scanning electron microscopy of sarcoptic mange lesions in swine

Scanning electron microscopy revealed that lesions of sarcoptic mange in swine, pass through 3 different stages. During the first 3 weeks of infestation, adult female mites tunnel into the epidermis. During the following 3 or 4 weeks, the surface openings of these tunnels become covered with keratinized epidermal crust which increases in thickness. After 7 weeks of infestation, the crust falls off, the tunnel openings become apparent again and most of the mites vacate these tunnels.

Etiologic studies on late-term swine abortions

One hundred thirty-eight swine abortions were studied in detail in an effort to identify an etiologic agent. A viral agent was implicated in 7 cases. Bacteria were isolated in less than half of the examined cases: however, in 61% of the cases, motile, filamentous organisms were observed in tissues and fluids. Although swine sera from farms experiencing reproductive problems had a high reactor rate to Leptospira bratislava antigen, electron microscopy of the observed organism revealed a wall-free prokaryote morphologically typical of the class Mollicutes.

Effect of zearalenone on the growth of mouse embryos from blastocysts to the egg cylinder stage in vitro

Embryos were harvested at the blastocyst stage from nontreated outbred mice and were grown in vitro for 4 days. Embryos cultured in control medium hatched and grew to the egg cylinder stage. Purified zearalenone (ZEN) added to the culture medium at concentrations of 8.5 to 68 micrograms/ml decreased the number of embryos growing, with a 50% decrease in the number growing in 32 micrograms of ZEN/ml of medium. Embryos growing in ZEN had decreased numbers of cells derived from the inner cell mass, normal growth of the trophoblast, less cellular differentiation than was seen in control embryos, and increased numbers of phagosomes. Undifferentiated cells of the inner cell mass of control and treated embryos were of the same size, as determined by morphometric analysis. Addition of 25 micrograms of estradiol/ml of culture medium caused no decrease in number of embryos growing or in embryonic size. Saturation of culture medium with ZEN (68 micrograms/ml) did not inhibit the growth of a tissue culture line of goat synovial cells. Seemingly, ZEN at concentrations near saturation inhibited the growth of mouse embryos in vitro. This effect was not duplicated with similar concentrations of estradiol and was not manifested in culture-adapted cells.

Hemodynamics, plasma eicosanoid concentrations, and plasma biochemical changes in calves given multiple injections of Escherichia coli endotoxin

Twelve male neonatal calves (39 to 50 kg) were allotted to 3 groups of 4 calves each. All calves were anesthetized with halothane, and then Escherichia coli endotoxin was given intravenously (3 times) and intraperitoneally (3 times) during a 6-hour period. Group-1 calves were untreated, group-2 calves were pretreated with a low dose of flunixin meglumine (1.1 mg/kg of body weight), and group-3 calves were pretreated with a high dose of flunixin meglumine (4.4 mg/kg). In calves of group 1, the mean systemic arterial blood pressure (MABP) and cardiac output (CO) decreased, but pulmonary arterial pressure increased after the initial intravenous and intraperitoneal injections of endotoxin. In calves of this group, these changes were accompanied by increased plasma thromboxane B2 (TxB2) concentration. During this period, increased plasma TxB2 concentration or hemodynamic changes were not detected in calves of groups 2 and 3. Only calves of group 1 had altered hemodynamics early in the experiment; however, after 6 hours, calves of all 3 groups had similarly decreased CO and MABP. In calves of the untreated group, plasma 6-keto-prostaglandin (PG)F1 alpha concentration increased steadily from the beginning of the experiment until 3 hours later. The CO and MABP were low at the time when serum 6-keto-PGF1 alpha concentration was high; however, these 2 measurements also were low in treated calves who did not have correspondingly high plasma 6-keto-PGF1 alpha concentration. Regional blood flow analysis did not reveal correlations between prostanoid concentrations and altered blood flow to selected tissues.(ABSTRACT TRUNCATED AT 250 WORDS)

Ultrastructure of equine endothelial cells exposed to endotoxin and flunixin meglumine and equine neutrophils

An in vitro system of cultured equine endothelial cells was evaluated as a model for endotoxin (ET) exposure in the horse. Primary cell lines from pulmonary vessels and aortas were cultured from tissues of 6 horses. Effects of ET alone with and without serum and in combination with the cyclo-oxygenase inhibitor flunixin meglumine and isolated equine neutrophils were evaluated by transmission electron microscopy. Cells plus serum were incubated with 10, 25, 50, or 100 micrograms of ET/ml of incubation medium for 1, 3, 8, or 24 hours. Cells without serum were cultured for 1 and 3 hours. Flunixin meglumine was used at a concentration of 20 micrograms/ml. Cells also were incubated in the presence of 1,000, 5,000, or 20,000 neutrophils/ml plus ET and in the presence of a combination of ET and flunixin meglumine for 1 or 3 hours. Endotoxin alone did not cause cell damage, and the only evidence of an effect was an increased number of secondary lysosomes at incubation hour 8. At incubation hour 24, cells appeared normal. Endotoxin plus neutrophils caused cells to become round and detach from the growth substrate. Cell pathologic changes included swollen and distorted mitochondria and cytoplasmic vacuolization. Response to the ET plus neutrophil combination was variable and ranged from 5% to 50% of the cells being affected. The variability appeared to have some correlation with cell age, as well as individual preparation of neutrophils.

The effect of chlorphentermine pretreatment on the toxicity of nitrogen dioxide in mice

Chlorphentermine HCl (CP) was used to induce preexisting alveolar alterations resembling a pulmonary lipidosis in mice to study these effects on the severity and duration of nitrogen dioxide (NO2) toxicity. Results indicated that a daily dose of 120 mg/kg for 14 days produced consistent histopathologic changes characterized by an accumulation of large foamy macrophages. Male Swiss-Webster mice were divided into a control and three treatment groups. Group 1 received 120 mg/kg CP po daily for 2 weeks followed by exposure to air for 48 hr. Group 2 received 20 ppm NO2 for 48 hr via whole-body inhalation, and group 3 received 120 mg/kg CP daily for 2 weeks followed by 20 ppm NO2 for 48 hr. The fourth group served as a nontreated control and received water in place of CP and air in place of NO2. All groups were compared by morphologic evaluation of pulmonary tissues at the light and electron microscopic levels at Days 0, 1, 3, 5, and 7 after the 48-hr exposure to air or NO2. In a second experiment using the same treatment groups, thin-section light microscopy was used to count the number of type I and type II cells and macrophages. NO2 exposure alone caused deaths in 20.8 and 18.5% of the mice in the two studies, but no deaths were seen in the combination groups from both experiments. Histopathologic evaluation showed a typical cellular response to the NO2 exposure, but differences were noted between the two groups receiving NO2 on this treatment. There was increased type II cell hyperplasia and terminal bronchiolitis on Days 0 and 1 but less on Days 3 to 7 in the combination group compared to the NO2 alone group. CP treatment prior to NO2 exposure caused less terminal bronchiolar epithelial hyperplasia and less pulmonary edema than was seen in the NO2 along group. The CP treatment appeared to protect against the lethal effects of NO2 at the concentration and time of exposure used and altered the cellular repair mechanism that occurs in response to NO2 toxicity. CP treatment prior to NO2 exposure caused significantly less loss of type I cells and less increase in type II cells due to NO2 damage. The combination treatment also caused an increase in macrophages greater than that seen in either individual treatment, and this number remained increased through 5 days post-NO2 exposure, whereas the NO2 alone caused a steady increase in macrophages following the exposure until Day 3.(ABSTRACT TRUNCATED AT 400 WORDS)

In vitro characterization of porcine juvenile articular cartilage

Dispersed cell cultures were established from the articular cartilage of the proximal portion of the humerus of young pigs. Articular and epiphyseal portions of the cartilage were separated, minced, and enzymatically dispersed, using bacterial collagenase. Morphologically, 2 cell types were observed, using phase-contrast microscopy. Smaller polygonal cells (32.5 +/- 3.5 microns diameter) containing cytoplasmic granules were found in both areas of the cartilage. In cultures from the articular region, cells grew as monolayer cultures and initially did not demonstrate contact inhibition. In cultures from the epiphyseal region, cells grew in a multilayered manner in a colonial arrangement with cells being released from the center of the colony into the culture medium. Small granular particles (0.03 to 0.08 micron diameter) were secreted by cells in both culture systems. Particle secretion was greater in epiphyseal cultures than in articular cultures with the rate decreasing as confluency was approached. These particles stained positively for lipid and alkaline phosphatase. Acridine orange was also incorporated into the granules. The 2nd cell type, a stellate-shaped cell (60 +/- 7.6 micron diameter), was found mainly surrounding the outside of colonial areas in epiphyseal cultures. These cells did not secrete small granular particles and stained positive for factor VIII. Evaluation of cultures by scanning and transmission electron microscopy further supported the presence of 2 cell types. With scanning electron microscopy, the smaller polygonal cell was characterized by varying sizes of blebs (0.03 to 0.1 micron diameter) associated with the cell membrane and small cytoplasmic processes projecting from the cell's surface.(ABSTRACT TRUNCATED AT 250 WORDS)

A neoplasm of globule leukocytes in a cat

A neoplasm involving the ileo-cecal-colic junction, thymus, and tracheobronchial lymph nodes of a 7-year-old domestic cat was composed of dense sheets of round to oval mononuclear cells with oval to indented nuclei, moderate amounts of cytoplasm, and variable numbers of round eosinophilic granules. These granules are brown to black in phosphotungstic acid hematoxylin-stained sections and stain variably with the periodic acid-Schiff stain. They are 0.8 to 1.5 micron in diameter, limited by a single unit membrane, and have variable electron density. Light microscopic cellular morphology and staining characteristics as well as ultrastructural features of these cells are consistent with feline globule leukocytes. Morphologic features of the neoplastic cells in the present case are similar to those of the only other reported neoplasm of globule leukocytes which also involved the intestine of a cat.

Equine endothelial cells in vitro

Certain in vitro culture conditions were determined for equine endothelial cells obtained from the aorta and pulmonary arteries. Cells were enzymatically isolated from the vessel lumen, using clostridial collagenase (2.5 mg/ml of Hanks's balanced salt solution) incubated at 37 C for 30 minutes. Cells were cultured in alpha minimum essential medium supplemented with plasma-derived and nonplasma-derived bovine fetal sera, endothelial cell-growth supplement, heparin, and antibiotics. Smooth muscle cell growth was not inhibited with nonplasma-derived animal sera, plasma-derived equine serum, or heparin. Heparin and a serum replacement were toxic to the cells used in the present study. Statistically significant differences were not found between the various media supplements.

Electron microscopic studies on the interaction between normal mice peritoneal phagocytes and Treponema hyodysenteriae, Treponema innocens and Bacteroides vulgatus

One hundred and twenty female mice (CF1 strain) were divided into three groups of 40. The first group was injected intraperitoneally with broth cultures of Treponema hyodysenteriae. The second group was injected with a combination of T. hyodysenteriae and Bacteroides vulgatus. The third group was injected with Treponema innocens. Peritoneal wash from four mice of each group was collected at eight time intervals postinjection, then prepared for and examined by light and electron microscopy. Peritoneal wash from one mouse at each time interval was prepared for microbiological examination. Treponema hyodysenteriae produced peritoneal macrophage aggregation, transient neutrophilia and macrophage cytolysis. Cytolysis was characterized by rarefaction of the cytoplasm, vesiculation of the endoplasmic reticulum, mild swelling of the mitochondria and disruption of the nuclear and ctyoplasmic membranes. The combination of T. hyodysenteriae and B. vulgatus produced macrophage aggregation and marked neutrophil necrosis. Peritoneal macrophages phagocytized more T. hyodysenteriae than B. vulgatus during early postinjection intervals. Treponema innocens failed to produce cytotoxicity of peritoneal macrophages but did produce macrophage aggregation and transient neutrophilia. Treponema hyodysenteriae and T. innocens did not multiply in the mice peritoneal cavity and were reisolated up to 16 hours postinjection. Bacteroides vulgatus was reisolated up to 24 hours postinjection.

Ultrastructural characterization of colonic lesions in pigs inoculated with Treponema hyodysenteriae

Twelve pigs were inoculated orally with pure cultures of Treponema hyodysenteriae. Pigs were necropsied at different time intervals postinoculation; colonic specimens were collected and prepared for light and electron microscopy. The earliest colonic lesion detected by electron microscopy consisted of superficial vascular congestion and dilatation, edema of the lamina propria and intercellular separation of the epithelial cells at the crypt shoulders. This lesion progressed to epithelial cell necrosis and extrusion into the lumen and extravasation of red cells. Large numbers of spirochetes were present and free, between, over and under necrotic epithelial cells whether in place or partially extruded. Spirochetal penetration of colonic enterocytes and intracytoplasmic multiplication were confirmed in this study. The spirochetes were found to invade the epithelial cells only from their lateral borders. The relationship between T. hyodysenteriae and the colonic anaerobes was not determined.