A global assessment of freshwater mollusk shell oxygen isotope signatures and their relation to precipitation and stream water.

Records of δ18O in stream flow are critical for understanding and modeling hydrological, ecological, biogeochemical and atmospheric processes. However, the number of such records are extremely limited globally and the length of such time series are usually less than a decade. This situation severely handicaps their use in model testing and evaluation. Here we present a global assessment of freshwater mollusk (bivalves & gastropods) isotope data from 25 river basins that have stream water isotope values, water temperature data and shell material isotope signatures. Our data span a latitude range of 37.50°S to 52.06°N. We show that δ18O signatures in freshwater mollusks are able to explain 95% of the variance of stream water δ18O. We use shell δ18O values and water temperature data to reconstruct stream water δ18O signatures. With freshwater mussel life expectancy ranging from a few years up to 200 years, this translation of mollusk metabolic properties into long term stream water isotope records is a promising approach for substantially extending global stream water isotope records in time and space.

Feline leukemia virus-associated myelopathy in cats.

Feline leukemia virus (FeLV) infection is associated with distinct neoplastic, hematologic, and immunosuppressive diseases. Here we report on a novel neurologic syndrome in 16 cats infected with FeLV for more than 2 years. Clinical signs consisted of abnormal vocalization, hyperesthesia, and paresis progressing to paralysis. The clinical course of affected cats involved gradually progressive neurologic dysfunction invariably resulting in euthanasia. Microscopically, white-matter degeneration with dilation of myelin sheaths and swollen axons was identified in the spinal cord and brain stem of affected animals. Neither neoplastic nor hematologic diseases commonly associated with FeLV infection were present. Fungal and protozoal infection in one animal was suggestive of impaired immune competence. Immunohistochemical staining of affected tissues revealed consistent expression of FeLV p27 antigens in neurons, endothelial cells, and glial cells. Furthermore, proviral DNA was amplified from multiple sections of spinal cord as well as intestine, spleen, and lymph nodes. These findings suggest that in a proportion of chronically FeLV-infected cats, a virus evolved with cytopathic potential for cells in the central nervous system.

The prognostic value of the modified Glasgow Coma Scale in head trauma in dogs.

A clinical coma scale modified from the Glasgow Coma Scale used for humans has been suggested as a useful predictor of outcome in the head trauma patient. The objective of this study was to correlate the modified Glasgow Coma Scale (MGCS) score of dogs with head trauma with their probability of survival. Thirty-eight dogs with head trauma were selected and retrospectively evaluated. The information retrieved from the medical record of each dog included signalment, body weight, cause of head trauma, MGCS, presence of concurrent neck pain, and outcome (dead or alive) after 48 hours. Logistic regression was used to model survival in the 1st 48 hours as a function of MGCS, gender, weight, and calvarial fractures. The MGCS ranged from 5 to 18. Seven dogs died within 48 hours of the head trauma. The MGCS could predict the probability of survival in the 1st 48 hrs after head trauma with 50% probability in a patient with a score of 8. Gender, weight, and presence of skull fractures did not predict survival. In conclusion, the MGCS is a useful index for prediction of outcome in dogs with head trauma.

Neurologic conditions causing lameness in companion animals.

Animals presented with non-weight-bearing lameness are a diagnostic challenge for the veterinarian. It is extremely important to distinguish between orthopedic and neurologic causes of lameness, because the diagnostic and therapeutic plans can be quite different. Myopathies can be confused with orthopedic disease because of gait abnormalities and associated muscle pain. Common myopathies seen in companion animal medicine include polymyositis, muscular dystrophy, endocrine and infectious myopathies, and myasthenia gravis. Lameness caused by disease of the nerve root or nerve is confused with orthopedic disease because of the disturbances of a nerve's sensory distribution (nerve-root signature) or disruption of the motor innervation. The diseases of the nerve root or nerve discussed are lateralized intervertebral disk disease, spinal cord neoplasia, malignant peripheral nerve sheath tumors, and traumatic neuropathies. The diagnosis of these diseases requires careful attention to the signalment, a complete history, and a thorough physical examination focusing on the neurologic and orthopedic components. Ancillary testing should be selected based on these results and a minimum database. Electrodiagnostic testing, radiography, and advanced imaging may help to localize the lesion more precisely and sometimes to confirm the diagnosis. Surgical exploration and histopathology often provide the definitive diagnosis. These cases of non-weight-bearing lameness are a diagnostic challenge, but when successful resolution can be reached, it is gratifying to the clinician, client, and patient.

Analysis of cerebrospinal fluid from dogs and cats after 24 and 48 hours of storage.

OBJECTIVE: To compare differential cell counts and cell characteristics of CSF samples analyzed immediately or after storage for 24 and 48 hours at 4 C with and without the addition of autologous serum. DESIGN: Prospective study. ANIMALS: 36 dogs and 6 cats. PROCEDURE: CSF samples were collected from the cerebellomedullary cistern and divided into 250-microliter aliquots. Slides of CSF samples were prepared by use of cytocentrifugation immediately and after 24 and 48 hours of storage with addition of autologous serum (final concentrations, 11 and 29%). Differential cell counts and number of unrecognizable cells were compared among preparations. RESULTS: Significant differences in the differential cell counts were not detected among samples analyzed before or after storage. Although the number of unrecognizable cells increased with storage time, this did not result in a significant effect on cell distribution or diagnosis. Cells in CSF samples stored with 11% serum more closely resembled cells in fresh samples than did cells in samples stored with 29% serum. CONCLUSIONS AND CLINICAL RELEVANCE: CSF samples collected at veterinary clinics remote from a diagnostic laboratory or during nonoperational hours may be preserved through the addition of autologous serum. Evaluation of such samples is likely to result in an accurate diagnosis for at least 48 hours after collection.

Anatomical localization of immunoreactive oxytocin and beta-endorphin in the bovine neurointermediate lobe.

BACKGROUND: Beta-endorphin and oxytocin immunocytochemical localization were examined in the neurointermediate lobe (lobus nervosus and pars intermedia) of the bovine hypophysis in order to describe the anatomical distribution of these two neurointermediate lobe hormones. METHODS: Twenty-seven bovine hypophyses were collected from slaughterhouse animals (seven mature lactating cows, eleven mature nonlactating cows, three nulliparous heifers, and six steers). Hypophyses were immunostained for oxytocin-containing fibers and beta-endorphin-secreting cells by using the avidin biotin-immunoperoxidase method. The distributions of beta-endorphin-positive cells and oxytocin-positive nerve fibers were plotted on projected outlines of the hypophyses. Immunoreactive staining intensity was graded numerically as weak, moderate, or heavy by three individuals who had no knowledge of the animals' physiological status. RESULTS: Oxytocin immunoreactivity was confined to the lobus nervosus while beta-endorphin staining was confined to the pars intermedia and the pars distalis. However, oxytocin immunopositive neurosecretory terminals were distributed more heavily in that part of the lobus nervosus bordering the pars intermedia than in the center of the lobe. CONCLUSIONS: These results were similar to those previously reported for the rat (Swaab et al., 1975; J. Neural Transm., 36:195-215; Deftos and Catherwood, 1980; Life Sci., 27:223-228).

The retinol-binding protein of the expanding pig blastocyst: molecular cloning and expression in trophectoderm and embryonic disc.

Retinol-binding protein (RBP) is a major secretory product of the porcine conceptus. Using an oligonucleotide probe corresponding to a highly conserved region of all known mammalian RBP, we have isolated an apparently full-length cDNA clone for porcine conceptus RBP from a cDNA library constructed from pig conceptuses collected between days 13-17 of pregnancy. The cDNA was 937 base-pairs in length and coded for a protein whose inferred amino-terminal sequence was identical to that reported for both porcine conceptus RBP and porcine serum RBP. Its length was consistent with the size (approximately 1 kilobase) of the RBP message in porcine conceptuses. Porcine conceptus RBP and human serum RBP share 91% amino acid sequence identity. The inferred differences in sequence were evenly distributed throughout the length of the polypeptide. RBP mRNA was detectable within the trophoblast of day 11 porcine conceptuses by in situ hybridization with a 618-basepair 35S-labeled probe corresponding to the 3' end of porcine RBP. Silver grain density was distributed relatively uniformly over the trophoblast and the inner cell mass. Western blot analysis of conceptus culture medium demonstrated that the conceptuses of cattle (on day 19) and sheep (on day 15) as well as pigs secrete RBP during early pregnancy. Secretion of large quantities of RBP by the trophoblast of preimplantation pig conceptuses suggests important roles for vitamin A and RBP near the time of conceptus elongation.

Expression of trophoblastic interferon genes in sheep and cattle.

The trophoblastic interferons ovine and bovine trophoblast protein-1 (oTP-1 and bTP-1, respectively) have been implicated as mediators of maternal recognition of pregnancy in sheep and cattle. The objective of this study was to describe the onset and duration of gene expression for oTP-1 and bTP-1 in preimplantation ovine and bovine conceptuses by in situ hybridization and Northern analysis. Sections from paraffin-embedded ovine conceptuses, collected on Days 10, 11, 12, 13, and 15 of gestation (n = 1, 3, 3, 2, 2), and bovine conceptuses, collected on Days 12/13, 15/16, and 19 (n = 2, 4, 5), were hybridized to specific [35S]-labeled cDNA probes. Two different probes, one encompassing bases 442-918 and representing both coding and 3'-untranslated regions, and a second 3'-specific probe (bases 650-912) were used to detect oTP-1 mRNA. At all stages examined, oTP-1 mRNA was confined to trophectoderm of ovine conceptuses. Consistent with earlier studies, expression increased markedly at Day 13. oTP-1 mRNA was detected at low levels in seven of seven ovine conceptuses prior to Day 13 when the longer probe was employed. With the 3'-specific probe, however, oTP-1 mRNA was detected in only one of the seven ovine conceptuses prior to Day 13. Thus, although low amounts of oTP-1 mRNA may be present in ovine conceptuses prior to Day 13, massive induction of this mRNA occurs on Day 13 coincident with the initiation of maternal recognition of pregnancy.(ABSTRACT TRUNCATED AT 250 WORDS)

The Arthus reaction in cats deficient in Hageman factor (factor XII).

A study was made of the Arthus reaction in an animal model of Hageman-factor deficiency, namely Hageman trait cats, and in control cats with normal Hageman-factor activity. At three time points, there was a significant decrease (P less than 0.01) in the size of the cutaneous Arthus reaction to chicken red blood cells in biopsies from Hageman trait cats compared with the reaction in biopsies from control animals. Injection of a positive control, histamine, and a negative control, phosphate-buffered saline, produced no significant differences between the two groups. Hageman trait cats had a significant decrease (P less than 0.001) in the number of neutrophils in the skin lesions compared with controls. When Hageman trait cats were injected intravenously with purified cat Hageman factor, Arthus reactions were similar to those observed in control cats.

Progesterone induction of the uterine milk proteins: major secretory proteins of sheep endometrium.

Progesterone induction of the uterine milk proteins (UTMP), the major secretory products of the ovine uterus during pregnancy, was studied in ovariectomized ewes given physiological levels of progesterone for 0, 2, 6, 14, or 30 days. Western blotting of uterine flushes and of endometrial explant culture medium, endometrial RNA analyses on dot and Northern blots, and immunocytochemistry performed on uterine tissue sections demonstrated the presence of low levels of UTMP mRNA and UTMP protein after 6 days of progesterone therapy, and increasing levels of UTMP production and secretion after 14 days. Highest activity was observed at Day 30. The induction of the UTMP progressed from small amounts of antigen present in the supranuclear region of a few epithelial cells in deep and middle-depth regions of uterine glands in the Day 6 progesterone-treatment group to large amounts detected in epithelial cells spread throughout the length of the glands in later groups. UTMP production was also identified in the uteri of intact ewes at Day 16 (but not earlier) of the estrous cycle and during early pregnancy (Days 14 to 22). Production of a protein similar to the UTMP was also noted in the uterus of a pregnant cow. The UTMP provide a good model of a progesterone-responsive secretory protein in a mammal whose synthesis is increased gradually over a period of weeks.

The Arthus reaction in domestic cats.

A classic Arthus reaction was elicited in normal domestic cats using chicken red blood cells as antigen. The response was quantitated grossly by measuring the area of the resulting skin bleb at several set time intervals and by microscopic examination of biopsies taken at the conclusion of each of the trials. This method produced an intense Arthus reaction in each of the cats tested.