Equine Melanocytic Tumors: A Retrospective Study of 53 Horses (1988 to 1991)

A study of 57 cutaneous melanocytic tumors from 53 horses revealed 4 distinct clinical syndromes: melanocytic nevus, dermal melanoma, dermal melanomatosis, and anaplastic malignant melanoma. Melanocytic nevus and anaplastic melanoma each had histopathologic features that distinguished them from dermal melanoma and dermal melanomatosis. Dermal melanoma and dermal melanomatosis were histologically similar but could be differentiated by their clinical features. Melanocytic nevi were diagnosed in 29 horses with an average age of 5 years; they were solitary, superficial masses that occurred in both grey and nongrey horses, and in which surgical excision was generally curative. Dermal melanomas were diagnosed in 20 horses with an average age of 13 years; all horses of known coat color were grey. Eight horses with an average age of 7 years had 1 or 2 discrete dermal melanomas. Follow-up information was available for 6 horses; metastases occurred in 2 horses, and surgical excision was apparently curative in 4 horses. Dermal melanomatosis was diagnosed in 12 grey horses with an average age of 17 years; all 6 of these horses evaluated had internal metastases. In 2 aged nongrey horses with anaplastic malignant melanoma, the tumors metastasized within 1 year of diagnosis. Two tumors with features of both melanocytic nevus and dermal melanoma remained unclassified.     

Single and multiple dose pharmacokinetics of a novel mirtazapine transdermal ointment in cats

Single and multiple dose pharmacokinetics (PK) of mirtazapine transdermal ointment applied to the inner ear pinna of cats were assessed. Study 1 was a randomized, cross‐over single dose study (n = 8). Cats were treated once with 0.5 mg/kg of mirtazapine transdermal ointment applied topically to the inner ear pinna (treatment) or administered orally (control) and then crossed over after washout. Plasma was collected predose and at specified intervals over 96 hr following dosing. Study 2 was a multiple dose study (n = 8). Cats were treated daily for 14 days with 0.5 mg/kg of mirtazapine transdermal ointment applied topically to the inner pinna. Plasma was collected on Day 13 predose and at specified intervals over 96 hr following the final dose. In Study 1, single transdermal administration of mirtazapine resulted in mean T_max = 15.9 hr, C_max = 21.5 ng/mL, AUC_0‐24 = 100 ng*hr/mL, AUC_0‐∞ = 260 ng*hr/mL and calculated half‐life = 26.8 hr. Single oral administration of mirtazapine resulted in mean T_max = 1.1 hr, C_max = 83.1 ng/mL, AUC_0‐24 = 377 ng*hr/mL, AUC_0‐∞ = 434 ng*hr/mL and calculated half‐life = 10.1 hr. Mean relative bioavailability (F) of transdermal to oral dosing was 64.9%. In Study 2, daily application of mirtazapine for 14 days resulted in mean T_max = 2.1 hr, C_max = 39.6 ng/mL, AUC_0‐24 = 400 ng*hr/mL, AUC_0‐∞ = 647 ng*hr/mL and calculated half‐life = 20.7 hr. Single and repeat topical doses of a novel mirtazapine transdermal ointment achieve measurable plasma concentrations in cats.     

Experimental Neospora Caninum Infection in Pregnant Dairy Heifers Raises Concentrations of Pregnancy‐Associated Glycoproteins 1 and 2 in Foetal Fluids

Plasma concentrations of PAG‐1 are used for pregnancy diagnosis and as a marker of placental/foetal well‐being, while those of PAG‐2 may be an indicator of abortion risk in Neospora caninum‐infected cows. Studies have shown that N. caninum infection modifies PAG‐1 and PAG‐2 patterns in maternal blood plasma. However, no prior work has examined the effects of N. caninum infection on concentrations of PAGs in foetal fluids. In this study, PAG‐1, PAG‐2 and pH levels were determined in the amniotic and allantoic fluids of foetuses collected at 152 days of gestation from control uninfected dams and from dams experimentally infected with N. caninum on Day 110 of gestation. Foetal fluids from infected foetuses had significantly higher PAG‐2 concentrations (p = 0.026) and pH values (p = 0.02) than fluids from non‐infected foetuses. In infected foetuses, significantly higher concentrations of PAG‐1 (p < 0.001) and PAG‐2 (p < 0.001) were detected in fluid samples showing antibodies against N. caninum than those without antibodies. Moreover, pH values were significantly higher (p = 0.011) in foetal fluid samples with antibodies than in samples from non‐infected foetuses. In conclusion, this is the first report on the effect of N. caninum infection on PAG levels in foetal fluids. Our results indicate that following the experimental infection of dams with N. caninum on Day 110 of gestation, foetal fluids collected from the infected foetuses of these dams featured higher PAG‐1 and PAG‐2 levels and pH values than fluids from non‐infected controls, provided that the samples tested showed the presence of antibodies. The clinical implications of these findings are that following infection with N. caninum, most cows will experience some level of placental damage and that this injury correlates with foetal fluid PAG levels and pH.     

Morphologic and biochemical characterization of hyperextension of the metacarpophalangeal and metatarsophalangeal joints in llamas

OBJECTIVE: To determine the morphologic and biochemical characteristics of hyperextension of the metacarpophalangeal and metatarsophalangeal joints in llamas. ANIMALS: 12 adult llamas (6 with bilateral hyperextension of the metacarpophalangeal or metatarsophalangeal joints and 6 age- and sex-matched control llamas). PROCEDURES: Llamas were evaluated by use of lameness examination, ultrasonography, and radiography. A CBC, serum biochemical analysis, and determination of concentrations of trace minerals in serum and liver samples were performed. Llamas were euthanized, and samples of the superficial digital flexor tendon, deep digital flexor tendon, and suspensory ligament were obtained from 4 areas and snap-frozen in liquid nitrogen or suspended in neutral-buffered 10% formalin. Immunohistochemical evaluation of collagen types I and III and assays for measurement of lysyl oxidase activity were performed. RESULTS: 2 affected llamas had a visible gait deficit associated with metacarpophalangeal joint hyperextension. Radiographic evidence of osteoarthritis was detected in 1 severely affected llama, and ultrasonographic changes of soft tissue mineralization and suspensory desmitis were observed in 2 llamas. Liver concentrations of copper were lower and serum concentrations of zinc higher in affected llamas, compared with values in control llamas. Lysyl oxidase activity and collagen distribution did not differ significantly between groups. CONCLUSIONS AND CLINICAL RELEVANCE: Hyperextension of the metacarpophalangeal or metatarsophalangeal joints in llamas does not appear to be the result of injury or degeneration of the suspensory ligament or flexor tendons. Lower copper concentrations coupled with higher zinc concentrations in affected llamas may be indicative of secondary copper deficiency.     

Reproductive biology of pond reared Nile tilapia, Oreochromis niloticus L.

The reproductive performance of female Nile tilapia, Oreochromis niloticus L., reared in ponds under tropical conditions was studied. The experiments used stock matured to the age of 2–4 months and a size of 30–50 g. Oocyte development proved a better indicator for the determination of the size at first maturation than the development of the gonado-somatic index. The Nile tilapia became ‘stunted' in the sense that early breeding took place, but the somatic growth of the stock still continued. This result indicates that the earlier breeding of Nile tilapia is not a real bottleneck for the expansion of this production sector. No relationship was found between the condition factor and the size at first maturation or the relative fecundity. This led to the conclusion that aggravation of the living conditions is not a major cause of earlier breeding of pond-reared O. niloticus.     

Efficient plant regeneration via organogenesis in “Egusi” melon (Colocynthis citrullus L.)

Plant regeneration protocol of “Egusi” melon (Colocynthis citrullus L.) was established using three local (“Ejagham”, “Sewere” and “Barablackedge”) and one improved (NHC1-130) cultivars. Cotyledonary explants of different lengths (1/2, 1/4 and 1/6) excised from 4- or 8-day-old seedlings germinated in vitro were cultured on MS medium supplemented with different concentrations of 6-benzylaminopurine (BA). The best results were obtained when cotyledons from 4-day-old seedlings were cut into 2 (1/2) halves. Plant regeneration was optimal on medium containing 5 mg/l BA, yielding 86.3%, 77.0% and 76.3% shoot induction frequencies amongst the three local cultivars of “Ejagham”, “Sewere” and “Barablackedge”, respectively. In NHC1-130, the highest shoot induction frequency (85%) was obtained on medium containing 2 mg/l BA. Adventitious shoots were elongated on medium containing 0.1 mg/l BA and successfully rooted on hormone-free MS medium. Flow cytometric analysis revealed 70% of the plants to be diploid.     

Rapid wastage of Alaska glaciers and their contribution to rising sea level

We have used airborne laser altimetry to estimate volume changes of 67 glaciers in Alaska from the mid-1950s to the mid-1990s. The average rate of thickness change of these glaciers was -0.52 m/year. Extrapolation to all glaciers in Alaska yields an estimated total annual volume change of -52 +/- 15 km3/year (water equivalent), equivalent to a rise in sea level (SLE) of 0.14 +/- 0.04 mm/year. Repeat measurements of 28 glaciers from the mid-1990s to 2000-2001 suggest an increased average rate of thinning, -1.8 m/year. This leads to an extrapolated annual volume loss from Alaska glaciers equal to -96 +/- 35 km3/year, or 0.27 +/- 0.10 mm/year SLE, during the past decade. These recent losses are nearly double the estimated annual loss from the entire Greenland Ice Sheet during the same time period and are much higher than previously published loss estimates for Alaska glaciers. They form the largest glaciological contribution to rising sea level yet measured.     

Effect of the Type and Number of Prostaglandin Treatments on Corpus Luteum, the Largest Follicle and Progesterone Concentration in Dairy Cows

Lactating dairy cows (n = 72) with a mature corpus luteum (CL) (diameter of > or = 17 mm) determined by ultrasonography and having a follicle with a diameter of > or = 10 mm were randomly assigned to four groups. Cows were treated with cloprostenol i.m. once or twice, or with dinoprost i.m. once or twice with an 8-h interval. The ovaries of each cow were scanned daily by transrectal ultrasonography to measure the changes in the areas of CL and the largest follicle and to determine the occurrence of ovulation. Oestrus was verified twice daily. In addition, blood sample was withdrawn from each cow daily for measuring progesterone (P4) concentrations. Significant decreases in the percentage changes relative to areas of CL and P4 concentrations or increases in the percentage changes in the area of the largest follicle on day 0 were detected in each group during the experiment. However, the type of the drug and the number of the treatments had no significant effect on those parameters. Cows ovulated with or without showing oestrus (group A) and cows exhibiting no oestrus and ovulation (group B) were also evaluated. In contrast to the mean area of the CL and the mean concentration of P4 on day 0, the mean area of the largest follicles between the two groups on day 0 differed significantly. Significant decreases in the percentage changes relative to the area of the CL and P4 concentration or increases in the percentage changes relative to the area of the largest follicle during the experiment were detected in both groups; however, there were no group differences. Treatment of dairy cows with two injections of prostaglandins (cloprostenol or dinoprost) at an 8-h interval resulted in more cows being observed in oestrus within 5 days after treatment and having significantly higher pregnancy rate than those treated with a single prostaglandin injection.     

Clinical and pathologic findings in two draft horses with progressive muscle atrophy, neuromuscular weakness, and abnormal gait characteristic of shivers syndrome

Two Belgian geldings, 4 and 14 years old, respectively, with muscle atrophy, weakness, and abnormal gait characteristic of severe advanced shivers were examined clinically and on necropsy. Neurologic examination revealed no evidence of ataxia, and the clinical diagnosis was neuromuscular weakness and shivers. Necropsies of both horses, including examination of pituitary, brain, spinal cord, spinal roots and ganglia, and peripheral nerves, revealed no gross or histologic abnormalities. Examination of multiple skeletal muscle specimens revealed chronic myopathic changes and periodic acid-Schiff positive, amylase-resistant inclusions within muscle fibers, characteristic of equine polysaccharide storage myopathy. It is suggested that underlying metabolic myopathy may be the cause of muscle weakness and cramping in horses with shivers.