Management of obstructive urolithiasis and concurrent urethral rupture in a goat.

A 4-month-old, male castrated Alpine White goat presented to the University of Guelph, Veterinary Teaching Hospital, with urolithiasis and a ruptured urethra. A tube cystostomy was performed using an indwelling Foley catheter. Postoperatively, the goat remained in good health, and was discharged with the cystostomy catheter in situ. Five weeks following surgery, the goat was noted to pass urine through its urethra. Seven weeks following surgery, the catheter became dislodged and the goat was observed to urinate normally. Six months following surgery, the goat was apparently healthy and urinating normally. Tube cystostomy may be a useful therapeutic option in the management of small ruminants with obstructive urolithiasis with concurrent rupture of the urethra, especially for cases in which treatment cost is a limiting factor.

In situ analysis of trifluorothymidine-resistant (TFTr) mutants of L5178Y/TK+/- mouse lymphoma cells.

TFTr mutants of L5178Y/TK+/- mouse lymphoma cells are analyzed as they appear in situ following cloning and incubation for 9-11 days in soft agar cloning medium. These TFTr mutants can be divided by colony size into sigma, small colony, and lambda, large colony, mutants. The use of a size discriminator on an automatic colony counter allows the production of histograms to evaluate the size distribution of colonies on a plate. The evaluation of these size distribution curves provides insight into the properties of sigma and lambda mutants. From these analyses several conclusions may be drawn. The sigma phenotype is preferentially associated with the TFTr subpopulation of a treated culture. The sigma phenotype is not an artifact of delayed toxicity following treatment. The frequency of quantifiable sigma mutants is not affected by agar concentrations between 0.20% and 0.45% in the cloning medium. TFTr sigma mutants are produced spontaneously and can be induced by a variety of mutagens. The decline in overall detectable mutants frequency observed for some mutagens with increasing time after treatment is due to the decline in sigma mutant frequency. The quantitation of both sigma and lambda mutants is thus useful in obtaining maximum utility of the information provided by the L5178Y/TK+/- mouse lymphoma assay.

Analysis of trifluorothymidine-resistant (TFTr) mutants of L5178Y/TK+/- mouse lymphoma cells.

Three classes of TFTr variants of L5178Y/TK+/- -3.7.2C mouse lymphoma cells can be identified--large colony (lambda), small colony (sigma), and tiny colony (tau). The sigma and lambda mutants are detectable in the routine mutagenesis assay using soft agar cloning. The tau mutants are extremely slow growing and are quantitated only in suspension cloning in microwells. Variants of all three classes have been analyzed in the process of evaluating the usefulness of the thymidine kinase locus in L5178Y/TK+/- mouse lymphoma cells for detecting induced mutational damage. 150 of 152 variants from mutagen treated cultures and 163 of 168 spontaneous mutants were TFTr when rechallenged approximately 1 week after isolation (3 weeks after induction). All of the 41 mutants assayed for enzyme activity were TK-deficient. The sigma and tau phenotypes were found to correlate with slow cellular growth rates (doubling time greater than 12 h), rather than from effects of the TFT selection or mutagen toxicity. Cytogenetic analysis of sigma mutants approximately 3 weeks after induction shows an association between the sigma phenotype and readily observable (at the 230-300 band level) chromosomal abnormalities (primarily translocations involving that chromosome 11 carrying the functional TK gene) in 30 of 51 induced mutants studied. Using an early clonal analysis of mutants (approximately 2 weeks after induction) 28 of 30 sigma mutants showed chromosome 11 rearrangements. All lambda mutants studied (17 of 17 evaluated 3 weeks after induction and 8 of 8 evaluated 2 weeks after induction) showed normal karyotypes (at the 230-300 band resolution level), including the chromosome 11s. These observations support the hypothesis that sigma (and likely tau) mutants represent chromosomal mutations and lambda mutants represent less extensive mutations affecting the TK locus. The inclusion of sigma mutants in the total induced mutant frequency, as well as distinguishing them as a separate subpopulation of TK-deficient mutants, is, therefore, essential in obtaining maximum utility of the information provided by the L5178Y/TK+/- mouse lymphoma assay.

Emission tomographic measurement of local cerebral blood flow in humans by an in vivo autoradiographic strategy.

An in vivo autoradiographic strategy is described for the measurement of local cerebral blood flow in humans by positron emission tomography, based on an application of the single-compartment model originally proposed by Kety. A variety of factors are considered upon which the successful quantitation of local blood flow depends. These factors include the mode of tracer administration and the definition of the arterial input function; the choice of scan parameters to assure unique and sensitive values of flow throughout the physiological range of interest; the influence of these parameters on the stability and signal/noise characteristics of the computed flow; the error introduced by the presence of heterogeneity of flow within a volume element; and factors related to the choice of the radiotracer itself. The in vivo autoradiographic method is compared to an alternative local cerebral blood flow method employing continuous inhalation of oxygen-15-labeled carbon dioxide. The general relevance of these issues to all local blood flow methods intended for emission tomographic application is emphasized.

On the uniqueness of cerebral blood flow measured by the in vivo autoradiographic strategy and positron emission tomography.

Factors are examined in this report which govern the uniqueness and sensitivity of regional cerebral blood flow (rCBF), as determined by an in vivo autoradiographic strategy and positron emission tomography (PET), and a series of theorems is derived which specify conditions under which a unique relationship between cumulative cranial activity of the tracer (C) and regional blood flow (f) may be assured. It is demonstrated that, independent of the specific form of the arterial tracer input function, flow is a unique function of C whenever the start time (T1) of the PET scan is coincident with the start of tracer infusion. Other theorems state that, even for nonzero T1S, a unique solution for flow may be expected, as long as the duration of the scan is sufficiently short. The implementation of this theory is illustrated using arterial tracer activity curves obtained in three normal subjects by a multiple arterial sampling procedure following the bolus i.v. infusion of 20-30 microCi of [15O]water. Based on these arterial curves, it is confirmed that the C vs. f relationship resulting from scan parameters T1 = 0 and T2 = 1.5 min (i.e., a PET scan of 90 s commencing with tracer infusion) has an excellent separation of flow values within the range of physiological interest, whereas a 90-s scan beginning at time T1 = 1.7 min results in poorer separation of flow values and loss of the monotonic relationship between C and f at higher flows. The results of this study serve to clarify the in vivo autoradiographic method for measuring rCBF in humans and help to define favorable study parameters for assuring uniqueness and sensitivity of the flow measurement.

Effectiveness of cognitive skill remediation in acute stroke patients.

The purpose of this study was to determine whether a cognitive skills remediation program could help acute stroke patients regain important thinking skills. Patients in a community hospital stroke program were pre-tested in three skill areas--visual scanning, visual-spatial orientation, and time judgment--and randomly assigned to a treatment (n = 16) or control (n = 17) group. The treatment group received cognitive skill retraining on a one-to-one basis for 30 minutes per day, 3 days per week, for 3 weeks. The retraining involved the use of paper and pencil tasks, simple cuing procedures, positive reinforcement, and immediate feedback. Although the control group did not receive this treatment, conventional therapies continued for both groups. Patients receiving treatment had overall and separate skill improvement scores that were significantly higher than those for control patients. The implications of this type of treatment program are discussed.

The utilization of trifluorothymidine (TFT) to select for thymidine kinase-deficient (TK-/-) mutants from L5178Y/TK+/- mouse lymphoma cells.

Trifluorothymidine (TFT), a thymidine analog, was analyzed for its ability to select for thymidine kinase-deficient (TK-/-) mutants. In comparison with BUdR, the traditional selective agent for TK-/- cells, it was determined that TFT at 1/50th the dose (1 microgram/ml vs. 50 microgram/ml) is a more effective and versatile selective agent for TK-/- mutants arising from the TK+/- -3.7.2C heterozygote of L5178Y mouse lymphoma cells. Since TFT acts more rapidly than BUdR, it can be utilized in procedures (such as the analysis of the phenotypic lag) requiring the fast arrest of cell division. Reconstruction analyses of effective TK-/- mutant recovery indicate that TFT can be used to recover mutants from significantly higher densities of TK+/- cells than can BUdR. In addition, TK-/- mutants can attain larger colony size in TFT than in BudR where severe stunting of growth occurs at high TK-/- cell densities. 190 of 194 isolated TFT-resistant large and small colony mutants (both spontaneous and induced).

Adenovirus antibody measured by the passive hemagglutination test.

Lefkowitz, Stanley S. (Variety Children's Research Foundation, Miami, Fla.), Julia A. Williams, Bernard E. Howard, and M. Michael Sigel. Adenovirus antibody measured by the passive hemagglutination test. J. Bacteriol. 91:205-212. 1966.-Rabbits immunized intravenously with adenovirus type 5 antigen were tested for antibody titers by use of the passive hemagglutination test (PHA). Primary and secondary responses were studied, and the class of antibody was determined by means of density gradient centrifugation and reduction with 2-mercaptoethanol (ME). It was found that the PHA was 10 to 100 times more sensitive than complement-fixation and neutralization tests for the detection of antibodies to adenovirus. The immunological response to primary immunization was dependent on the dose of antigen, with antibody appearing in as early as 3 days. After secondary stimulation with the same antigen, there was a rapid response which appeared to be less dose-dependent. It was found that a heavy 19S antibody sensitive to ME was produced early and was followed by a lighter, presumably 7S, ME-resistant antibody. Upon secondary stimulation, both 7S and 19S antibody increased to levels greater than those of the primary injection.