Identification of infrared absorption spectral characteristics of synovial fluid of horses with osteochondrosis of the tarsocrural joint

OBJECTIVE: To determine the feasibility of the use of Fourier-transform infrared (FTIR) spectroscopy within the midinfrared range to differentiate synovial fluid samples of joints with osteochondrosis from those of control samples. ANIMALS: 33 horses with osteochondrosis of the tarsocrural joint and 31 horses free of tarsocrural joint disease. PROCEDURES: FTIR spectroscopy of synovial fluid was used. Sixty-four synovial fluid samples from the tarsocrural joint were collected. Of these, 33 samples were from horses with radiographic evidence of osteochondrosis of the tarsocrural joint and 31 from control joints. Disease-associated features within infrared spectra of synovial fluid were statistically selected for spectral classification, and the variables identified were used in a classification model. Linear discriminant analysis and leave-one-out cross-validation were used to develop a classifier to identify joints with osteochondrosis. RESULTS: 12 significant subregions were identified that met the selection criteria. The stepwise discriminant procedure resulted in the final selection of 6 optimal regions that most contributed to the discriminatory power of the classification algorithm. Infrared spectra derived from synovial fluid of joints with osteochondrosis were differentiated from the control samples with accuracy of 77% (81% specificity and 73% sensitivity). CONCLUSIONS AND CLINICAL RELEVANCE: The disease-associated characteristics of infrared spectra of synovial fluid from joints with osteochondrosis may be exploited via appropriate feature selection and classification algorithms to differentiate joints with osteochondrosis from those of control joints. Further study with larger sample size including age-, breed-, and sex-matched control horses would further validate the clinical value of infrared spectroscopy for the diagnosis of osteochondrosis in horses.     

Photodynamic therapy for the treatment of periocular squamous cell carcinoma in horses: a pilot study

Objective  Local photodynamic therapy (PDT) is a novel cancer therapy in veterinary ophthalmology. A prospective pilot study seeking to demonstrate proof of principle and safety for the treatment of equine periocular squamous cell carcinoma (PSCC) was therefore conducted. We hypothesized that surgical excision with adjunctive local PDT is an effective and safe treatment for equine PSCC.
Procedures  Nine horses (10 eyes) with PSCC were treated with surgical resection, local infiltration of resulting wound beds with 2-[1-hexyloxyethyl]-2-devinylpyropheophorbide-a (HPPH) and irradiation with 665-nm wavelength diode laser. Regular follow-up ophthalmic examinations were performed.
Results  Surgical resection and PDT yielded disease-free intervals of 25–68 months in our study horses as of January, 2008. These results were obtained following a single treatment in seven horses and two treatments in one horse. In one horse, carcinoma in situ developed 2.5 months after partial surgical excision and PDT, requiring local excision under standing sedation.
Conclusions  Preliminary results suggest that surgical resection and adjunctive local PDT is a safe and effective novel treatment for PSCC in horses. More research is needed before PDT for the treatment of equine PSCC can be adequately compared with other current modalities. Important to future investigations regarding PDT, tumor recurrence rate, length of hospitalization, number of treatment episodes required to effect tumor remission, and total treatment costs should be examined in a controlled manner. Our present results and experiences suggest that this treatment may be useful in the treatment of equine PSCC.     

Effect of premedication with acetylpromazine on the disposition kinetics of thiopental

This study was performed to determine whether premedication with acetylpromazine alters the disposition kinetics of thiopental in normal dogs. Based on nonlinear least squares regression analysis of the plasma concentration-time data obtained in individual dogs, a three-compartment open model was selected to describe the pharmacokinetic behavior of thiopental. While clinically premedication appears to delay time of awakening from thiopental anesthesia, statistical comparison (Student's t-test for paired data) of pharmacokinetic terms showed no significant difference. This may be largely attributed to wide individual variation in each parameter. The rate of change in volume of distribution at zero time (mean +/- SD, n = 7), which is a parameter that might have been expected to vary significantly, was 97 +/- 106 ml/min X kg for thiopental alone and 77 +/- 60 ml/min X kg following acetylpromazine premedication. Body clearance of thiopental was 1.96 +/- 0.59 ml/min X kg in dogs without premedication and 1.55 +/- 0.49 ml/min X kg following acetylpromazine. By relating observed time of awakening to plasma concentrations of thiopental it was determined that awakening from anesthesia occurred at a concentration of 20 micrograms/ml whether or not the dogs were premedicated. It can only be concluded that while premedication with acetylpromazine appears to delay time of awakening from anesthesia, it does not change the disposition kinetics of thiopental or affect the plasma concentration at the observed time of awakening.     

Growth and reproductive development in freemartins hormonally treated from 1 to 79 weeks of age

Postnatal growth, steroid hormone profiles and response to steroid hormone treatment were studied in 18 freemartins and one normal female born co-twin with a bull. They were either treated postnatally with testosterone or estrone at one week of age, or left untreated until 50 weeks of age when they received silastic implants calculated to release either 12.9 microgram of estrone or 2.6 microgram of estradiol per day per kg of body weight. Later a dihydrotestosterone-treated group was added. Reproductive development was studied by palpation per rectum and by examination when animals were slaughtered at 79 weeks of age. Treated animals grew slightly faster than untreated animals. Testosterone in untreated freemartins averaged 76 and 87 pg/ml of blood plasma during weeks 1 to 48 and 52 to 56. Corresponding values for those animals with small testosterone implants (weeks 1 to 48) and with larger implants (weeks 52 to 56) were 130 and 272 pg/ml. Estrone and estradiol values appeared to fluctuate between 10 and 50 pg/ml but values are uncertain because they were below the sensitivity of the assay then available. Thus, circulating steroid hormone concentrations were similar to those reported for castrates. Testosterone stimulated clitoral development prenatally and postnatally. None of the treatments influenced vaginal depth, which averaged 4.0, 9.0 and 10.9 cm at 1, 24 and 52 weeks of age. Vaginal depth at birth was not a reliable indicator of freemartinism. Androgen may have inhibited udder development, whereas estrogen appeared to be stimulatory. The reproductive organs of the freemartin were characterized by differences in underdevelopment and the general presence of seminal vesicles. The latter structures, plus clitoral development at birth in 3 animals and postnatal response of the clitoris to testosterone is interpreted to indicate that the presence of androgens is one factor in abnormal development. Otherwise, gross morphology of the reproductive tract was not related to hormone treatment, postnatal gonadal histology, endocrinology or lymphocyte chromosomal karyotypes.     

Volatile N-nitrosamines in infant pacifiers sold in the United States as determined by gas chromatography/thermal energy analysis

Volatile N-nitrosamines in infant latex rubber pacifiers were determined using a modification of a previously described dichloromethane extraction procedure, followed by gas chromatography/thermal energy analysis. Under an interagency agreement between the National Center for Toxicological Research and the Consumer Product Safety Commission (CPSC), data were obtained on the baseline and compliance concentrations of volatile N-nitrosamines in infant pacifiers sold in the United States. Pacifiers made by 18 different manufacturers before and after the January 1, 1984 action level of 60 ppb was set by the CPSC were analyzed for volatile N-nitrosamines. N-Nitrosodibutylamine was the principal N-nitrosamine found, along with trace amounts of N-nitrosodimethylamine, N-nitrosodiethylamine, and N-nitrosopiperidine. Mean total volatile N-nitrosamine levels for baseline and compliance samples were 63.9 and 21.2 ppb, respectively. The pacifier lots sampled after January 1, 1984 showed a significant decrease in contamination levels, indicating that at least 98% of the market share is in compliance with the CPSC enforcement policy for N-nitrosamines in infant pacifiers sold in the United States.     

Non-ideal Behavior During Complete Dissolution of Organic Immiscible Liquid: 2. Ideal Porous Media

Column experiments were conducted using ideal natural sands and stainless-steel beads to examine the complete dissolution behavior of an organic immiscible liquid. Trichloroethene was used as the representative organic liquid. The elution curves exhibited multi-step behavior, with multiple extended periods of relatively constant contaminant flux. These secondary steady-state stages occurred at concentrations several orders-of-magnitude below aqueous solubility for the well-sorted sands. In contrast, the secondary steady-state stages occurred within 1 log of aqueous solubility for the poorly sorted sand. The non-ideal behavior is hypothesized to result from constraints to hydraulic accessibility of the organic liquid to flowing water, which may be expected to be mediated by the pore-scale configuration of the flow field and the fluid phases.     

Phoma stem canker (<Emphasis Type="Italic">Leptosphaeria maculans/L. biglobosa</Emphasis>) of oilseed rape (<Emphasis Type="Italic">Brassica napus</Emphasis>): is the G<Subscript>2</Subscript> Disease Index a good indicator of the distribution of observed canker severities?

Several disease indices (DI) have been proposed to assess the severity of phoma stem canker at late growth stages. The DI commonly used in France (called G₂ DI) consists of integrating the distribution of the proportions of plants observed within six canker severity classes into a single index. This index uses arbitrarily chosen coefficients associated to each class of canker severity. A given value of this DI can therefore be obtained with different distributions among the canker severity classes. Consequently, it is important to assess to what extent the G₂ DI is representative of the distribution of plants in canker severity classes. We show in this study that the G₂ DI is a good indicator of the distribution of the observed canker severities, using a dataset from different years, sites and cultivars; this illustrates the robustness of the G₂ DI.     

Cotton-root distribution as a function of trickle irrigation emitter depth

Summary The objective of this study was to evaluate the distribution of cotton (Gossypium hirsutum cv GSA 71) root system under four depths of trickle irrigation emitter. Cotton was grown on an Amarillo fine sandy loam (fine loamy, mixed thermic Aridic Paleustalf) at Lubbock, Texas. Trickle irrigation was applied at the surface (0), 0.15, 0.3, or 0.45 m depths in amounts calculated using daily pan evaporation, crop coefficient, and crop development stage. Effects of depth of trickle irrigation were evaluated by measuring the cotton root-length density in 0.15 m increments to the 0.90 m depth at distances of 0, 0.25, and 0.5 m perpendicular to the cotton rows. The root-length distributions were not significantly (0.05%) different in the top 0.15 m when the surface irrigated treatment was compared with the 0.45 m irrigation depth treatment. Root-length densities for the 0.15 and 0.3 m treatments were not significantly different from one another nor were they different from treatments within the evaluated zones (0 to 0.3 m or 0.15 to 0.45 m). Root-length density within the 0.3 to 0.6 m zone, was not significantly different for the 0.45 m treatment compared with the surface irrigation treatment. Root-length density in the 0.6 to 0.9 m zone was not significantly different for any treatment. Emitter depth of trickle irrigation did not significantly influence the depth or distribution of cotton-root development.