Canine Pancreatic‐Specific Lipase Concentrations in Dogs with Heart Failure and Chronic Mitral Valvular Insufficiency

Background

Chronic mitral valvular insufficiency (CMVI) in dogs is very common and might cause clinical signs of congestion and poor tissue perfusion.

Hypothesis

Poor tissue perfusion from CMVI causes pancreatitis in dogs, as indicated by serum pancreatic lipase concentrations.

Animals

Sixty‐two client‐owned dogs consisting of 40 dogs with different stages of heart failure from CMVI and 22 age‐matched healthy dogs, based on full cardiac exam and routine laboratory tests.

Methods

Prospective, controlled, observational study. Serum canine pancreatic lipase immunoreactivity (cPLI) concentrations were determined by quantitative cPLI test in healthy and CMVI groups.

Results

Serum cPLI concentrations were 54.0 μg/L (IQR: 38.0–78.8 μg/L) in control, 55.0 μg/L (IQR: 38.3–88.8 μg/L) in ISACHC I, 115.0 μg/L (IQR: 45.0–179.0 μg/L) in ISACHC II and 223.0 μg/L (IQR: 119.5–817.5 μg/L) in ISACHC III. Close correlation to serum cPLI concentration was found in the left atrial to aorta (LA/Ao) ratio (r = 0.597; P = .000) and the severity of heart failure (r = 0.530; P = .000).

Conclusions and Clinical Importance

This study found CMVI is associated with pancreatic injury in congestive heart failure caused by CMVI. Therefore, periodic monitoring on cPLI could be useful in monitoring dogs in heart failure.     

In vivo confocal microscopy of the normal equine cornea and limbus

Objective  To describe morphologic features, pachymetry and endothelial cell density of the normal equine cornea and limbus by in vivo confocal microscopy.
Animals studied  Ten horses without ocular disease.
Procedure  The central and peripheral corneas were examined with a modified Heidelberg Retina Tomograph II and Rostock Cornea Module using a combination of automated and manual image acquisition modes. Thickness measurements of various corneal layers were performed and endothelial cell density determined.
Results  Images of the constituent cellular and noncellular elements of the corneal epithelium, stroma, endothelium, and limbus were acquired in all horses. Corneal stromal nerves, the subepithelial nerve plexus, and the sub-basal nerve plexus were visualized. Cells with an appearance characteristic of Langerhans cells and corneal stromal dendritic cells were consistently detected in the corneal basal epithelium and anterior stroma, respectively. Median central total corneal thickness was 835 μm (range 725–920 μm) and median central corneal epithelial thickness was 131 μm (range 115–141 μm). Median central endothelial cell density was 3002 cells per mm² (range 2473–3581 cells per mm²).
Conclusions  In vivo corneal confocal microscopy provides a noninvasive method of assessing normal equine corneal structure at the cellular level and is a precise technique for corneal sublayer pachymetry and cell density measurements. A resident population of presumed Langerhans cells and corneal stromal dendritic cells was detected in the normal equine cornea. The described techniques can be applied to diagnostic evaluation of corneal alternations associated with disease and have broad clinical and research applications in the horse.     

Ultrastructural study of globidian parasites infecting the abomasum of sheep in Germany.

Globidian parasites infecting the abomasum of sheep in Germany were investigated by means of electron microscopy. The frequency of infection was found to be 93 %. The globidian cyst-like bodies contained multinucleate schizonts, developing merozoites or fully developed merozoites. Among the latter there were two different types, namely short and long forms. The process of merozoite formation was described in detail. The giant schizonts were subdivided into multinucleate cell portions of irregular size and shape. Their nuclei were then arranged at the periphery of the cell portions and underwent their last division which was combined with the differentiation of merozoites. The long form merozoites were elongated cylindrical in shape with terminal nucleus. They measured 7.7 μm in length and 1.0 μm in width. The merozoites of the short type were spindle-shaped with a central nucleus. They were 5.0 μm long and 1.0 μm wide. The globidian parasites were located in a parasitophorous vacuole of an intact host cell.     

Ultrastructure features of camel cornea--collagen fibril and proteoglycans

Introduction The uniform distribution of collagen fibrils and proteoglycans maintain the transparency of normal cornea. We describe the ultrastructural features of camel cornea including collagen fibrils and proteoglycans (PGs). Methods Camel corneas (of 6‐, 8‐, and 10‐month‐old animals) were fixed in 2.5% glutaraldehyde containing cuprolinic blue in sodium acetate buffer and processed for electron microscopy. The ‘AnalySIS LS Professional’ program was used to analyze the collagen fibril diameter. Results The camel cornea consists of four layers: the epithelium (227 μm), stroma (388 μm), Descemet’s membrane (DM), and endothelium. The epithelium constituted 36% of the camel cornea, whereas corneal stroma constituted 62% of the corneal thickness (629 μm). The PGs in the posterior stroma were significantly larger in number and size compared with the anterior and middle stroma. The collagen fibril diameter was 25 nm and interfibrillar spacing 40 nm. Fibrillar structures are present throughout the DM. Conclusion The structure of the camel cornea is very different from human and other animals. The unique structure of the cornea might be an adaptation to help the camel to survive in a hot and dry climate. The camel cornea may also be a good model to study the effect of hot and dry climates on the cornea.     

Comparative observation of freeze–thaw‐induced damage in pig,rabbit, and human corneal stroma

Objective Although variations exist between species with respect to outcomes after cryopreservation, little is known about the differences in the susceptibility of the corneal stroma to cryoinjury. We performed this study to investigate freeze–thaw‐induced damage in keratocytes and collagen in rabbit, pig, and human corneas. Animals studied Rabbit, pig, and human. Procedures We prepared 250‐μm‐thick anterior stroma from rabbit, pig, and human corneas after scraping off the epithelium and endothelium. Each 250‐μm‐thick corneal stroma without epithelium was placed in a 50‐mL tube, frozen with liquid N₂ for 15 min and taken out to thaw rapidly at 37 °C. This procedure of rapid freezing and thawing was repeated three times. Differences between the species with respect to cells and collagen structures were examined using hematoxylin–eosin (H&E) staining, terminal deoxynucleotidyl transferase‐mediated nick end labeling (TUNEL) assay, and transmission electron microscopy (TEM). We orthotopically transplanted the pig and rabbit corneal transplants after the triple freeze–thaw cycle into rabbit eyes and evaluated graft survival. Results On gross examination, rabbit corneas became opaque after the triple freeze–thaw procedure, while pig and human corneas remained transparent. Histologically, keratocytes were apoptotic on TUNEL assay and TEM in rabbit, pig, and human corneas. Collagen fibrils were fragmented and the arrangement of collagen fibrils was severely disturbed in rabbit corneas on H&E staining and TEM; collagen was well preserved in pig and human corneas. Rabbit corneal stroma underwent autolysis after transplantation, whereas the pig corneal stroma remained clear for 1 month. Conclusions Our study showed that rabbit corneal stroma was more susceptible to freeze–thaw injury than pig and human corneas.     

Major histocompatibility class II expression in the normal canine cornea and in canine chronic superficial keratitis

OBJECTIVE: To compare the expression of major histocompatibility complex (MHC) class II antigen in the corneas of normal dogs and dogs affected with chronic superficial keratitis (CSK). METHODS: MHC class II expression was determined in frozen sections of normal canine cornea and cornea from lesions of CSK by immunohistochemistry using a monoclonal antibody directed against the canine MHC class II molecule. Langerhans cell phenotype was determined morphologically and by histochemical determination of ATPase activity. To determine the influence of gamma interferon on expression of MHC class II molecules by corneal cells, corneal explants were cultured with the cytokine and MHC class II expression determined as above. RESULTS: Numerous MHC class II-expressing cells were demonstrated within the stroma and epithelium of the normal corneal limbus and conjunctival epithelium while very little MHC class II expression was detected in the central region of normal canine cornea. In limbal and conjunctival epithelium, cells expressing MHC class II antigen showed ATPase activity, suggesting that they were Langerhans cells. Corneas from dogs with CSK showed MHC class II expression associated with stromal cells, some of which exhibited a dendritic morphology while most were lymphocytic. Corneal epithelial cells within the lesion also aberrantly expressed MHC class II. Corneal explants expressed MHC class II to varying degrees after differing periods of incubation with the cytokine gamma interferon. CONCLUSIONS: While the normal central cornea has little MHC class II expression, aberrant expression occurs in CSK, associated with secretion of gamma interferon by infiltrating CD4-expressing lymphocytes. Although this change is likely to be a secondary feature of the CSK lesion, increased MHC class II expression may play a part in perpetuating the corneal inflammation seen in the disease.     

Angiostatin and integrin alphavbeta3 in the feline, bovine, canine, equine, porcine and murine retina and cornea

PURPOSE: Angiogenesis is tightly controlled in the ocular tissues of domestic animals but its mechanisms are not fully understood. This is largely because of insufficient data on the expression of molecules that impact angiogenesis. Because angiostatin and one of its receptors integrin alphavbeta3 inhibit and promote angiogenesis, respectively, we hypothesized that the normal retina and cornea of domestic animals would express angiostatin but not integrin alphavbeta3. PROCEDURE: Normal eyes of the cat, cow, dog, horse, pig and rat were evaluated for angiostatin and integrin alphavbeta3 by light and electron immunocytochemistry and estern blots. RESULTS: Angiostatin was detected in the corneal epithelium of the cat, dog, horse, pig and rat, but was not found in cow corneal epithelium. Angiostatin was localized in the nerve fiber layer, ganglion cell layer, inner and outer plexiform layers, and the photoreceptor layer of the cat, cow, dog and rat. Horse and pig retinas showed additional staining in the matrix of the inner nuclear layer. Immunogold electron microscopy further confirmed angiostatin in cat retina. Western blots showed angiostatin in corneal and retinal homogenates. Integrin alphavbeta3 was absent in cornea and retina of all the species studied. CONCLUSION: These data show that angiostatin, an inhibitor of angiogenesis, is present while integrin alphavbeta3, which promotes angiogenesis, is absent in normal cornea and retina of the domestic animals in this study with the exception being angiostatin absence in cow corneal epithelium. Therefore, angiostatin may contribute to the anti-angiogenic environment in the normal domestic animal eye while its absence in the cow may contribute to greater propensity for corneal vascularization. Because integrin alphavbeta3 is one of the receptors for angiostatin, its absence may prevent angiostatin from killing normal retinal and corneal cells.     

Evaluation of Iron Deficiency Using Reticulocyte Indices in Dogs Enrolled in a Blood Donor Program

Background

People donating blood more than twice annually are at risk of developing iron deficiency. Little is known about the iron status of dogs enrolled in blood donor programs.

Hypothesis

Dogs donating blood ≥6 times annually will show evidence of iron deficiency based on their reticulocyte indices.

Animals

Thirteen dogs enrolled in a blood donor program donating ≥6 times over the preceding 12 months and 20 healthy nondonor control dogs.

Methods

Prospective observational study. Mature red blood cell (RBC) indices, reticulocyte indices, serum iron, serum ferritin, and total iron‐binding capacity (TIBC) were compared between groups.

Results

Packed cell volume (median 47%, range 40–52%, P < .01), hematocrit (median 46.4%, range 40.3–52.5%, P < .01), and reticulocyte count (median 16,000/μL, range 9,000–38,000/μL, P < .01) were significantly lower in the blood donor dogs. No statistically significant differences were noted in the mature RBC indices between groups. Both reticulocyte mean corpuscular volume (median 88.8 fL, range 83.4–95.5 fL, P = .03) and reticulocyte hemoglobin content (median 24.6 pg, range 23.1–26.6 pg, P < .01) were significantly lower in the blood donor group. Serum iron and ferritin were similar between groups; however, TIBC was significantly higher in the control group (median 403 μg/dL, range 225–493 μg/dL, P = .02).

Conclusions

The findings in dogs donating ≥6 times annually suggest the presence of iron‐deficient erythropoiesis in this population.     

Effect of bovine freeze-dried amniotic membrane (Amnisite-BA™) on uncomplicated canine corneal erosion

Objective   To evaluate the effectiveness of bovine freeze-dried amniotic membrane (FD-AM) (Amnisite-BA™) in the surgical treatment of corneal ulceration in dogs.
Animals studied   Eight normal Shih-tzu dogs.
Procedures   The corneas of 16 eyes were scored with an 8.0-mm trephine under general anesthetic and 100% ethanol was applied to remove a standardized button of corneal epithelium. The eyes were treated as described below and the corneas were evaluated 48 h later. The dogs were divided into four treatment groups: (i) control, (ii) amniotic membrane transplantation (AMT), (iii) nictitating membrane flap and (iv) contact lens. The proportion of the corneal wound that healed was calculated and all eyes were enucleated. Histological sections of cornea were assessed with the proliferating cell nuclear antigen (PCNA) assay.
Results   The proportion of corneas healed in the different treatment groups was (i) 38.02%, (ii) 89.15%, (iii) 52.31%, and (iv) 60.56%. Epithelial healing was significantly increased in the AMT group (ii) ( P  = 0.001) while groups (iii) and (iv) were not significantly different from the control group ( P  = 0.537 and P  = 0.198, respectively). The number of PCNA positive cells was (i) 275.00, (ii) 740.50, (iii) 285.75 and (iv) 420.59, these varying compared with the control group with statistical significance of (ii) P  = 0.002, (iii) P  = 0.999, and (iv) P  = 0.467. The greatest healing rate and epithelial cell proliferation was achieved with AMT compared to the other treatment regimes.
Conclusions  The results of this study show that FD-AM transplantation is an effective treatment for enhancing canine corneal wound healing and suggest that the approach will provide superior results compared to conventional treatments for the condition.     

茉莉酸甲酯对匍枝筋骨草细胞生长和β-蜕皮甾酮积累的影响

匍枝筋骨草悬浮细胞中含有较高β-蜕皮甾酮,为了进一步提高其β-蜕皮甾酮含量,通过添加茉莉酸甲酯(MeJA)进行一系列试验研究。以4~10代筋骨草悬浮细胞为试验材料,测定不同处理浓度和处理时间的MeJA对细胞生长、β-蜕皮甾酮积累的影响,细胞生长量采用称量计数,β-蜕皮甾酮含量则使用高效液相进行检测。结果表明:匍枝筋骨草悬浮细胞生长曲线及β-蜕皮甾酮积累曲线符合Logistics模型。在细胞快速生长的初始期(第4天)或中期(第7天)添加不同浓度的MeJA,对细胞生长影响相对较小,生长曲线均有小高峰,分别出现在处理后第5天和第3天,干物质积累量分别达到0.60和0.62 g。而在细胞快速生长的高峰期添加MeJA,细胞生长曲线呈下降趋势,细胞鲜重和干重显著低于CK(P<0.05)。在细胞快速生长的初始期或中期添加MeJA后细胞鲜重与β-蜕皮甾酮积累量呈显著相关。在细胞快速生长的初始期或中期添加10~50 μmol·L^-1 MeJA后,细胞鲜重与CK对比表现为显著增加,其中添加50 μmol·L^-1 MeJA后细胞鲜重最佳,最高可达到35.90 g,显著高于其他处理(P<0.05)。而同样条件下β-蜕皮甾酮表现为积累量小幅增加,最高量为0.5095 mg·g^-1。添加100~200 μmol·L^-1 MeJA均会抑制细胞的生长,其中添加200 μmol·L^-1 MeJA细胞鲜重与CK相比显著下降,抑制率最高可达到38.88%。而添加100~200 μmol·L^-1 MeJA后β-蜕皮甾酮积累量表现为大幅提升,最高可达3.5315 mg·g^-1,为同期CK的14.44倍(P<0.01)。在细胞快速生长的高峰期添加10~200 μmol·L^-1 MeJA后,细胞鲜重与CK相比都表现为下降,说明在此时添加这些浓度MeJA可抑制细胞的生长,最高抑制率可达31.01%。而在细胞快速生长的高峰期添加10~50 μmol·L^-1 MeJA后,β-蜕皮甾酮积累量可在短时间内大量激增,β-蜕皮甾酮积累量最高达到1.4136 mg·g^-1,是CK的5.06倍(P<0.01)。添加100~200 μmol·L^-1 MeJA则积累量较少。在细胞快速生长的中期添加100 μmol·L^-1 MeJA条件下对细胞的刺激较小,β-蜕皮甾酮积累量最高,达到3.5315 mg·g^-1。     

Cortisol Concentrations in Well‐Regulated Dogs with Hyperadrenocorticism Treated with Trilostane

Background

There are no clear treatment guidelines for dogs with clinically well‐regulated hyperadrenocorticism in which serum cortisol concentrations before and after an ACTH stimulation test performed 3–6 hours after trilostane administration are < 2.0 μg/dL.

Objective

To determine if serum cortisol concentrations measured before (Pre1) and after (Post1) ACTH stimulation at 3–6 hours after trilostane administration are significantly lower than cortisol concentrations measured before (Pre2) and after (Post2) ACTH stimulation 9–12 hours after trilostane administration, in a specific population of dogs with clinically well‐regulated hyperadrenocorticism and Pre1 and Post1 <2 μg/dL.

Animals

Thirteen client‐owned dogs with clinically well‐regulated hyperadrenocorticism and Pre1 and Post1 serum cortisol concentrations <2.0 μg/dL 3–6 hours after trilostane administration.

Methods

Prospective study. Dogs had a second ACTH stimulation test performed 9–12 hours after trilostane administration, on the same day of the first ACTH stimulation test. Cortisol concentrations before and after ACTH stimulation were compared using a paired t‐test.

Results

Cortisol concentrations before (1.4 ± 0.3 μg/dL) and after the first stimulation (1.5 ± 0.3 μg/dL, mean ± SD) were significantly lower than cortisol concentration before the second stimulation (3.3 ± 1.6 μg/dL, P = .0012 each). Cortisol concentration before the first stimulation was also significantly lower than cortisol concentration after the second stimulation (5.3 ± 2.4 μg/dL, P = .0001).

Conclusions and clinical importance

In dogs with clinically well‐regulated, trilostane‐treated, hyperadrenocorticism, and cortisol concentrations <2 μg/dL before and after the first stimulation, a second ACTH stimulation test performed 9–12 hours after treatment can result in higher cortisol concentrations that could support continued trilostane treatment.     

Hematoxylin Staining Reveals a Decrease in Nucleolar Diameter of Pig Oocytes Before Germinal Vesicle Breakdown

During oocyte growth, the morphology of the nucleolus changes into a compact and homogenous structure. The compact nucleoli in full-grown oocytes are not stained by aceto-orcein staining or immunofluorescence staining. In this study, we developed a hematoxylin staining method for pig oocytes in whole-mount preparations to visualize the nucleoli. Nucleoli of growing and full-grown oocytes were stained blue with hematoxylin. Using this staining method, the changes in the oocyte nucleolus during maturation were examined. The nucleolar diameter gradually decreased in maturing oocytes (10.7 ± 0.1 μm to 9.0 ± 0.7 μm, P<0.05) before germinal vesicle breakdown (GVBD). The results suggest that the nucleolar volume of oocytes decreases before GVBD.     

Minimum Inhibitory Concentrations of Equine Corynebacterium pseudotuberculosis Isolates (1996–2012)

Background

Few studies report the minimum inhibitory concentrations for antimicrobials against equine Corynebacterium pseudotuberculosis isolates.

Hypothesis/Objectives

To evaluate trends in the in vitro activities of 20 antimicrobials against equine Corynebacterium pseudotuberculosis isolates from 1996 to 2012 and to determine if a relationship exists between the minimum inhibitory concentration (MIC) and location of the abscess.

Animals

Corynebacterium pseudotuberculosis isolates from 196 horses with naturally occurring disease.

Methods

Retrospective and cross‐sectional design. Medical records were reviewed to obtain clinical and MIC data. Minimum inhibitory concentrations were determined by the microdilution technique. The MIC results over 3 periods were compared (1996–2001, 2002–2006, 2007–2012).

Results

The MIC₉₀ values for clinically relevant antimicrobials were as follows: chloramphenicol ≤4 μg/mL, enrofloxacin ≤0.25 μg/mL, gentamicin ≤1 μg/mL, penicillin =0.25 μg/mL, rifampin ≤1 μg/mL, tetracycline ≤2 μg/mL, trimethoprim‐sulfamethoxazole (TMS) ≤0.5 μg/mL, ceftiofur =2 μg/mL, and doxycycline ≤2 μg/mL. There were no significant changes in MIC results over the study period. There was no relationship between MIC patterns and abscess location.

Conclusions and Clinical Importance

The MIC ₅₀ and MIC ₉₀ values of antimicrobials evaluated in this study for equine isolates of C. pseudotuberculosis did not vary over time. Abscess location was not associated with different MIC patterns in cultured isolates. Several commonly used antimicrobials are active in vitro against C. pseudotuberculosis in vitro.     

Comparative observation of freeze–thaw-induced damage in pig, rabbit, and human corneal stroma

Objective  Although variations exist between species with respect to outcomes after cryopreservation, little is known about the differences in the susceptibility of the corneal stroma to cryoinjury. We performed this study to investigate freeze–thaw-induced damage in keratocytes and collagen in rabbit, pig, and human corneas.
Animals studied  Rabbit, pig, and human.
Procedures  We prepared 250-μm-thick anterior stroma from rabbit, pig, and human corneas after scraping off the epithelium and endothelium. Each 250-μm-thick corneal stroma without epithelium was placed in a 50-mL tube, frozen with liquid N₂ for 15 min and taken out to thaw rapidly at 37 °C. This procedure of rapid freezing and thawing was repeated three times. Differences between the species with respect to cells and collagen structures were examined using hematoxylin–eosin (H&E) staining, terminal deoxynucleotidyl transferase-mediated nick end labeling (TUNEL) assay, and transmission electron microscopy (TEM). We orthotopically transplanted the pig and rabbit corneal transplants after the triple freeze–thaw cycle into rabbit eyes and evaluated graft survival.
Results  On gross examination, rabbit corneas became opaque after the triple freeze–thaw procedure, while pig and human corneas remained transparent. Histologically, keratocytes were apoptotic on TUNEL assay and TEM in rabbit, pig, and human corneas. Collagen fibrils were fragmented and the arrangement of collagen fibrils was severely disturbed in rabbit corneas on H&E staining and TEM; collagen was well preserved in pig and human corneas. Rabbit corneal stroma underwent autolysis after transplantation, whereas the pig corneal stroma remained clear for 1 month.
Conclusions  Our study showed that rabbit corneal stroma was more susceptible to freeze–thaw injury than pig and human corneas.     

Plasma Peak and Trough Gentamicin Concentrations in Hospitalized Horses Receiving Intravenously Administered Gentamicin

Background

Gentamicin is an aminoglycoside antimicrobial commonly used in horses at 6.6 mg/kg IV once daily. Therapeutic drug monitoring (TDM) can confirm desired peak concentration is reached for common bacterial isolates, and detect toxicosis associated with high trough values.

Objectives

Determine the relationship between gentamicin dose and plasma concentration in hospitalized horses, and identify a starting dose range to achieve peaks > 32 μg/mL.

Animals

Sixty‐five horses (2002–2010) receiving once‐daily gentamicin with TDM performed (N = 99 sets).

Methods

Retrospective study. Data from hospitalized horses including weight, dose, plasma peak, and trough gentamicin concentration, creatinine concentrations and presence of focal or systemic disease were collected from medical records. Peak concentrations measured 25–35 minutes after administration were included (N = 77). Data were divided into low (<7.7 mg/kg), medium (7.7–9.7 mg/kg) and high (>9.7 mg/kg) dose groups, and were grouped by the horse having focal or systemic disease.

Results

Peak concentrations resulting from doses ≥7.7 mg/kg were 5.74 μg/mL (SE 2.1 μg/mL) greater than peaks from doses <7.7 mg/kg (P = .007). Peak concentrations was 3.6 times more likely to be >32 μg/mL if dose was ≥7.7 mg/kg (P = .04). There were no significant effects of dose on trough or creatinine concentration. At a given dose, horses with focal disease had higher peaks than those with systemic disease (P = .039).

Conclusions and Clinical Importance

These data suggest gentamicin dosage should be individually determined in horses using TDM, but support an initial once‐daily dose of 7.7–9.7 mg/kg IV to achieve peaks >32 μg/mL and trough concentrations <2 μg/mL. Further studies evaluating the safety of doses >6.6 mg/kg are required.     

Use of malathion against ectoparasites on lactating cows

The clinical effect, residues in milk and toxicological properties of a non-commercial formulation of malathion used as an ectoparasitic agent on cattle were investigated. The results show that the malathion preparation has a desired clinical effect. The maximum concentration of malathion in milk after topical application of 5 g malathion was 0.054 μg/ml 4–6 h post-treatment, and declined to 0.005 and 0.002 μg/ml 24 and 48 h post-treatment, respectively. Totally 0.006–0.03 % of the applied dose was excreted in the milk. No toxic effect, measured as inhibition of the cholinesterases in erythrocytes and plasma, could be detected after therapeutic use of malathion.The pharmacokinetic evaluation after 2.5 g intravenous administration of malathion, indicated that the kinetics could probably be described by a multicompartment model.     

Structure of the Cornea in Some Cervidae

The structure of the corneas of adult and young reindeer, roedeer and elk was studied. The corneas were strikingly similar in general appearance. The number of squamous cells was found to be the main difference. The thickness of the cornea and that of the membrane of Descemet was found to be greater in older animals.     

Ultrastructure of the cysts of Sarcocystis tarandivulpes from skeletal muscle of reindeer (Rangifer tarandus tarandus)

The cysts of S. tarandivulpes were found to be limited by a unit membrane which has been called the cyst membrane. The surface of the cysts was covered by closely packed and hexagonally arranged knob-like protrusions. The protrusions were 0.6–1.2 μm long and had an elliptical cross section. At the base of and between the bases of the protrusions the cyst mem brane was raised into low anastomosing folds which delineated shallow compartments. Between the folds the cyst membrane formed small vesicle-like invaginations into the cyst. On the apical part of the protrusions the cyst membrane had a smooth contour and was underlined by 2 layers of electron-dense material. Cyst ground substance divided the interior of the cyst into compartments containing either metrocytes or cystozoites. Cystozoites undergoing endodyogeny were present among the nondividing cystozoites. Some new terms were introduced to denote structures at the border of the cyst. The old terms are reviewed and the structural resemblance between S. tarandivulpes and S. odocoileocanis from Odocoileus virginianus is discussed.     

Subjective vs. objective analysis of the corneal endothelial cells in the rabbit cornea by scanning electron microscopy - a comparison of two different methods of corneal fixation

OBJECTIVE: To illustrate a method of quantitative scanning electron microscopy (SEM) for the evaluation of the corneal endothelia of small animals by comparing two commonly used fixation methods. ANIMALS STUDIED: Female New Zealand white rabbits, aged 10-12 weeks. PROCEDURES: The corneas were either dissected from the eye and placed in fixative (2% glutaraldehyde in 80 mm cacodylate, pH 7.4) or the whole eyeball immersed in fixative solution and the cornea dissected later. Lower (x 200) and high magnification (x 1,000-5,000) images were inspected for overall appearance. Magnification images (x 500) were used to measure the areas of 100 cells, and cell density (CD) calculated from the average area. RESULTS: Both fixation protocols yielded an intact endothelial surface, but the dissect- then-fix protocol resulted in more creasing and distortion artifacts that were avoided with the whole-eyeball fixation. Overall, the CD values were higher if the dissect-then-fix method was used, and the uniformity of the cell mosaic was less. The median CD values for the central, mid-peripheral and peripheral regions following dissect-then-fix protocols were 7,693, 7,353, and 7,071 cells/mm(2) (average eight corneas at each location). If the whole-globe fixation was used, the median CD values were 6,098, 5,747, and 4,785 cells/mm(2). CONCLUSION: Cell density values in SEM can be very different according to the fixation method used. A distinct regional difference in CD was evident, which was more pronounced if the cornea was fixed prior to being dissected from the eye.     

The effect of a bacterial endotoxin or cloprostenol on the clinical status and hormonal levels in 80-100 days pregnant gilts

An experiment was conducted to examine the effect of a lipopoly-saccharide (LPS) of Salmonella typhimurium on the luteal function in 80 days pregnant gilts. Four animals were i.v. injected with 2 μg LPS/kg body weight and 3 animals were i.m. injected with 500 μg cloprostenol (CP). Gilts which maintained pregnancy after the initial injection were reinjected with GP around day 100. Clinical observations were made and plasma levels of 15-keto-13,14-dihydro-PGF₂α, progesterone, oestradiol-17β and oestrone sulphate were analysed by radioimmunoassay.The LPS induced a characteristic clinical endotoxemia. All LPS treated gilts maintained pregnancy until day 100 when 1 gilt aborted, 1 was emergency slaughtered and 2 reinjected. The comparative injections of CP induced abortion! within 48 h in 2 of 3 gilts at 80 days and in all reinjected animals at 100 days of pregnancy. Progesterone decreased immediately after both LPS and CP injections. In non-aborting gilts, the progesterone decrease had a transient character. The PGF_2α metabolite levels responded to LPS by a dramatic surge of approximately 4 h duration. All abortions were accompanied by a massive release of PGF_2α reaching peak levels during expulsion of the foetuses. Oestradiol-17ß and oestrone sulphate followed an ascendent pattern between days 80 and 100. Occasional transient decreases in oestradiol-17ß or increases in oestrone sulphate levels after LPS and CP injections were observed in several animals. Abortions were followed by a sharp decrease of both oestrogens. Post-abortum reproductive disorders occurred frequently. Endocrine changes associated with post-abortum ovarian activity were relevant to the clinical and morphological observations. The relationship between the stage of pregnancy in the pig and its endocrine response to abortifacient agents as well as some foetopathic effects of the endotoxin are discussed.