Regimes of cosmic-ray diffusion in Galactic turbulence.

Cosmic-ray transport in astrophysical environments is often dominated by the diffusion of particles in a magnetic field composed of both a turbulent and a mean component. This process, which is two-fold turbulent mixing in that the particle motion is stochastic with respect to the field lines, needs to be understood in order to properly model cosmic-ray signatures. One of the most important aspects in the modeling of cosmic-ray diffusion is that fully resonant scattering, the most effective such process, is only possible if the wave spectrum covers the entire range of propagation angles. By taking the wave spectrum boundaries into account, we quantify cosmic-ray diffusion parallel and perpendicular to the guide field direction at turbulence levels above 5% of the total magnetic field. We apply our results of the parallel and perpendicular diffusion coefficient to the Milky Way. We show that simple purely diffusive transport is in conflict with observations of the inner Galaxy, but that just by taking a Galactic wind into account, data can be matched in the central 5 kpc zone. Further comparison shows that the outer Galaxy at > 5  kpc, on the other hand, should be dominated by perpendicular diffusion, likely changing to parallel diffusion at the outermost radii of the Milky Way.

[A new total knee arthroplasty with physiologically shaped surfaces. Part 2: First clinical results]. / Eine neuartige Kniegelenksendoprothese mit physiologischer Gelenkform. Teil 2: Erste klinische Ergebnisse.

The human medial tibial plateau is concave, whereas the lateral tibial plateau is convex. In a normal knee, the convex femoral condyles roll and glide on the tibia during the standing phase of walking. The designs of most commercially available knee prostheses do not take this morphological feature into consideration. The novel design of the AEQUOS G1 knee replacement prosthesis is based on the natural anatomy of the knee joint, with a convex lateral tibia plateau and a sagittal offset of the medial and lateral compartments. Following extensive development and testing, initial clinical results of the AEQUOS G1 prosthesis in a mulitcenter study are presented. From Mai 2005 to March 2007, 158 patients in 4 clinics underwent total knee arthroplasty with the AEQUOS G1 and agreed to participate in the study. Patients were evaluated preoperatively and at 3, 6 and 12 months of follow-up using a standardized protocol that included the American Knee Society Score (AKSS), the Oxford Knee Score (OKS) and the Visual Analog Scale (VAS) for pain. After 3 months, 151 patients appeared for follow up appointments, after 6 months, 134, and after 12 months, 127. The mean range of motion preoperatively was 97.0 degrees (+/-19.9 degrees ) and 107.5 degrees (+/-15.9 degrees ) 12 months after surgery. The AKSS, as well as the modified OKS, significantly improved (p<0.0001) from preoperative scores of 98.8 (+/-35.8) and 37.3 (+/-6.9) points, respectively, to 165.8 (+/-34.1) and 21.9 (+/-7.8) points, preoperatively, and 12 months postoperatively. The VAS score significantly decreased (p<0.001) from 7.4 (+/-1.8) points preoperatively to 1.9 (+/-2.2) points 12 months postoperatively.One implant was revised because of arthrofibrosis and another due to patellar luxation. Two patients required revision because their implants revealed malalignement with ligamentous instability. No infections, aseptic loosening or other implant-specific complications were observed at this early follow-up. Good clinical results were observed at early follow-up with the AEQUOS G1 knee arthroplasty. However, longer follow-up is necessary for a general evaluation of the implant.

Up-regulation of GLT1 expression increases glutamate uptake and attenuates the Huntington's disease phenotype in the R6/2 mouse.

The striatum, which processes cortical information for behavioral output, is a key target of Huntington's disease (HD), an autosomal dominant condition characterized by cognitive decline and progressive loss of motor control. Increasing evidence implicates deficient glutamate uptake caused by a down-regulation of GLT1, the primary astroglial glutamate transporter. To test this hypothesis, we administered ceftriaxone, a beta-lactam antibiotic known to elevate GLT1 expression (200 mg/kg, i.p., for 5 days), to symptomatic R6/2 mice, a widely studied transgenic model of HD. Relative to vehicle, ceftriaxone attenuated several HD behavioral signs: paw clasping and twitching were reduced, while motor flexibility, as measured in a plus maze, and open-field climbing were increased. Assessment of GLT1 expression in striatum confirmed a ceftriaxone-induced increase relative to vehicle. To determine if the change in behavior and GLT1 expression represented a change in striatal glutamate handling, separate groups of behaving mice were evaluated with no-net-flux microdialysis. Vehicle treatment revealed a glutamate uptake deficit in R6/2 mice relative to wild-type controls that was reversed by ceftriaxone. Vehicle-treated animals, however, did not differ in GLT1 expression, suggesting that the glutamate uptake deficit in R6/2 mice reflects dysfunctional rather than missing GLT1. Our results indicate that impaired glutamate uptake is a major factor underlying HD pathophysiology and symptomology. The glutamate uptake deficit, moreover, is present in symptomatic HD mice and reversal of this deficit by up-regulating the functional expression of GLT1 with ceftriaxone attenuates the HD phenotype.

A comparison of canine normal hepatic alkaline phosphatase and variant alkaline phosphatase of serum and liver.

The isoenzyme of alkaline phosphatase from normal liver, the corticosteroid induced isoenzyme of alkaline phosphatase from serum and liver and a hepatocellular variant isoenzyme of alkaline phosphatase induced by lymphosarcoma have been partially purified and their the present modification incorporates Polybrene into buffer to eliminate this heparin interference. The proposed method shown excellent agreement with a reference procedure based on clottable protein, and excellent day-to-day precision (C.V.3.5%). The present method is easily adaptable to semi-automated measurements.

Effects of cyclopiazonic acid on the ultrastructure of rat liver.

Groups of Sprague-Dawley rats were dosed per os for 4 consecutive days with 0.0, 0.2, 2.0 or 4.0 mg cyclopiazonic acid (CPA)/kg body weight/day, and killed on the fifth day. Sections of liver were prepared for electron microscopic examination. Dilatation of the rough endoplasmic reticulum was observed in all hepatocytes examined from the 2 highest dose groups, and in about 25% of liver cells from the 0.2 mg CPA/kg/day group. Vesiculation of the rough endoplasmic reticulum also occurred in these groups, an increasing amount of vesiculation being observed with increasing dosage. Control sections exhibited neither of these characteristics. No proliferation of smooth endoplasmic reticulum, or blockage of bile canaliculi was observed in any group. Lysing cells were present only in the 4.0 mg CPA/kg/day group; mitochondria in the 2.0 and 4.0 mg CPA/kg/day dose groups were swollen. Nuclei were ultrastructurally normal in all groups. The primary cellular effect of CPA was on the endoplasmic reticulum, even at relatively low doses. Possible interactions of CPA with other toxins likely to be produced by the same fungus, such as aflatoxin, are considered.

Toxicity and neuropharmacology of cyclopiazonic acid.

Cyclopiazonic acid (CPA) was found to have many pharmacological properties in common with the antipsychotic drugs chlorpromazine and reserpine. Thus, in mice CPA at ip doses of 5-14 mg/kg body weight produced hypokinesia, hypothermia, catalepsy, ptosis, sedation without loss of righting reflex, tremor, gait disturbance, dyspnoea, opisthotonus, atypical convulsion and prolonged barbiturate-induced sleep. The ip LD50 of CPA was found to be 13 +/- 0.05 mg/kg. The tremors induced by near-lethal doses of CPA were associated with voluntary or forced movements (action tremors); they worsened during the days following treatment, but they were weak compared with the exhausting and continuous tremors of the whole body caused by 20 mg tremorine/kg (used for comparison). When death occurred only 24-259 min after administration of CPA (11-14 mg/kg), it was preceded by dypsnoea, cyanosis, opisthotonus and clonic leg movements and tonic extension of hind legs (convulsions). When death was delayed (2-6 days after CPA administration), it was preceded by prostration, ptosis, hypothermia, tremor and cessation of food and water intake resulting in cachexia; convulsions were not seen in this group of mice. CPA did not affect the rate of convulsion or death caused by either maximal electroshock or metrazol administration but it did delay the onset of metrazol-induced seizures. In rabbits, 10 mg CPA/kg body weight initially produced tachycardia, tachypnoea and sedation with an activated electroencephalogram. Of three rabbits given 10 mg CPA/kg one died, and in this rabbit slow delta waves were seen just before and during a brief period with clonic leg movements. In this animal death was accompanied by tonic extension of the hind legs, respiratory arrest and cardiac fibrillation; and epileptiform EEG was not seen at any time. The unexpected EEG activation with sedation in rabbits treated with CPA was similar to the effect of reserpine on EEG.

Combined effects of the mycotoxins aflatoxin B1 and cyclopiazonic acid on Sprague-Dawley rats.

This study was conducted to determine whether exposure to cyclopiazonic acid (CPA) and aflatoxin B1 (AFB1) would alter the toxicity associated with exposure to either toxin individually. Groups of male rats were administered 0, 0.1 or 4.0 mg CPA/kg body weight/day intragastrically (three groups per dose level) for three consecutive days and 30 min after each of these CPA doses the rats were dosed by gavage with 0, 0.1 or 2.0 mg AFB1/kg body weight/day. Six of the 12 rats given each of these nine treatments were killed on day 4 after the initial dosing, and the rest were allowed a recovery period of 4 days prior to being killed. Weight loss in the three groups receiving 2.0 mg AFB1/kg/day occurred within 24 hr of the first doses. Feed consumption by these rats was about 60% of that in the other groups. By the end of the recovery period, rats in these three groups had lost an average of 31-38 g. Feed consumption throughout the recovery period by rats in the 2.0-mg AFB1 groups was about 50% of the control value, except in the group that also received the high dose of CPA, in which it was 75%. Gross pathological findings were primarily limited to rats in the high AFB1 group, and included icterus, shrunken liver and lesions in the kidney at the cortico-medullary junction. Microscopic changes were characteristic of aflatoxicosis in rats. Glycocholic acid assays indicated liver damage only in those groups that received the high AFB1 dose. We conclude that neither toxin potentiates the action of the other at the dose levels used in this study.

Distribution, excretion and skeletal muscle effects of the mycotoxin [14C]cyclopiazonic acid in rats.

The distribution of the mycotoxin, cyclopiazonic acid (CPA), in tissues and its excretion in urine and faeces was studied in male Sprague-Dawley rats. Radiolabelled CPA was biosynthetically produced by cultures of Penicillium griseofulvum and was administered to rats either intraperitoneally (ip) or intragastrically (ig). Radiolabelled material was excreted in both urine and faeces from rats dosed by either route. There was no excretion of radioactivity as expired 14CO2. Biliary excretion apparently had a major role in the disposition of CPA, since 38% of the dose of radioactivity was excreted in the faeces of ip-dosed rats within 72 hr. Skeletal muscle tissue contained 48% of the radioactive dose 6 hr after either ip or ig administration. At 72 hr, skeletal muscle of the ip-dosed rats contained 3% of the dose, whereas rats dosed ig retained 8% of the dose in muscle. Degeneration was observed in muscle from rats treated with 8 mg CPA/kg/day for 4 days. The results indicate that some of the toxic effects observed in animals exposed to CPA (hyperaesthesia, hypokinesis, abnormal posture, opisthotonos and convulsions) may be due in part to direct effects of the toxin on muscle. Furthermore, if CPA or its metabolic products distributes in the tissues of other animals as it does in the rat, the potential exists for the exposure of humans to this mycotoxin by consumption of the meat of domestic animals fed contaminated feed.

67Ga-citrate and 99Tcm-MDP for estimating the severity of vertebral osteomyelitis.

The aim of this study was to evaluate the roles of 67Ga-citrate and 99Tcm-methylene diphosphonate (99Tcm-MDP) planar and single photon emission tomographic (SPET) imaging in patients with vertebral osteomyelitis. Thirty patients (22 females, 8 males) aged 62.7 +/- 16.4 years (mean +/- s) were enrolled prospectively between May 1995 and May 1998. The patients had been on antibiotics for 7 +/- 4 weeks prior to the study. Histology was available for all but nine patients with mild infections, who were evaluated by a combination of magnetic resonance imaging (MRI), clinical and laboratory tests. 67Ga-citrate (185 MBq) and three-phase bone (555 MBq 99Tcm-MDP) planar and SPET imaging were performed in all patients, together with MRI as a comparison. In total, 67 infectious foci were detected. Based on histology, there were four cases of severe, 13 cases of moderate and four cases of mild osteomyelitis; nine mild infections were also classified by the combination of MRI, clinical and laboratory results. Combined MRI and 67Ga-citrate SPET correctly classified all patients; MRI detected all 67 infectious foci, whereas 67Ga-citrate SPET identified 54 only. False-negative results were seen with all other modalities, especially in cases of mild and moderate infection. 67Ga-citrate SPET identified unsuspected cases of endocarditis (n = 2), paravertebral abscess (n = 1), subaxillary soft tissue abscess (n = 1) and rib osteomyelitis (n = 1). For 67Ga-citrate SPET, the target-to-background ratio was 2.24 +/- 0.31, 1.76 +/- 0.07 and 1.30 +/- 0.18 for severe, moderate and mild osteomyelitis, respectively. Significant differences were noted between severe and moderate infection (P = 0.0051) and between severe and mild infection (P < 0.0001); that between moderate and mild infection was non-significant. For 99Tcm-MDP planar and SPET imaging, and for planar 67Ga-citrate imaging, there was no correlation with severity. We conclude that 67Ga-citrate SPET is able to identify vertebral osteomyelitis and detect additional sites of infection. It can also aid in determining the severity of infection and, potentially, the response to therapy.

Aflatoxin reduction in corn through field application of competitive fungi.

Soil in corn plots was inoculated with nonaflatoxigenic strains of Aspergillus flavus and A. parasiticus during crop years 1994 to 1997 to determine the effect of application of the nontoxigenic strains on preharvest aflatoxin contamination of corn. Corn plots in a separate part of the field were not inoculated and served as controls. Inoculation resulted in significant increases in the total A. flavus/parasiticus soil population in treated plots, and that population was dominated by the applied strain of A. parasiticus (NRRL 21369). In the years when weather conditions favored aflatoxin contamination (1996 and 1997), corn was predominately colonized by A. flavus as opposed to A. parasiticus. In 1996, colonization by wild-type A. flavus was significantly reduced in treated plots compared with control plots, but total A. flavus/parasiticus colonization was not different between the two groups. A change to a more aggressive strain of A. flavus (NRRL 21882) as part of the biocontrol inoculum in 1997 resulted in a significantly (P < 0.001) higher colonization of corn by the applied strain. Weather conditions did not favor aflatoxin contamination in 1994 and 1995. In 1996, the aflatoxin concentration in corn from treated plots averaged 24.0 ppb, a reduction of 87% compared with the aflatoxin in control plots that averaged 188.4 ppb. In 1997, aflatoxin was reduced by 66% in treated corn (29.8 ppb) compared with control corn (87.5 ppb). Together, the data indicated that although the applied strain of A. parasiticus dominated in the soil, the nonaflatoxigenic strains of A. flavus were more responsible for the observed reductions in aflatoxin contamination. Inclusion of a nonaflatoxigenic strain of A. parasiticus in a biological control formulation for aflatoxin contamination may not be as important for airborne crops, such as corn, as for soilborne crops, such as peanuts.

Quantitative determination of equine alkaline phosphatase isoenzymes in foal and adult serum.

Automated and semiautomated assays were developed and validated for the determination of equine alkaline phosphatase isoenzymes including intestinal (IALP), bone (BALP), and liver (LALP). The addition of levamisole selectively inhibited more than 97% of LALP while inhibiting only 55% of IALP. Because these percentages were highly reproducible in an automated system, the IALP activity could be calculated in a sample. Bone alkaline phosphatase isoenzyme was selectively precipitated by adding an equal volume of wheat germ agglutinin (5 mg/mL), incubating for 30 minutes at 37 degrees C, and centrifugating. The LALP activity was determined from the supernatant fluid and BALP activity was calculated by subtraction from total ALP activity. The within-run coefficient of variation for determination of BALP activity was 4.7%. These assays were used to identify and quantify the isoenzymes present in pony foal sera through the first 21 days of life, in horse foal sera before colostrum ingestion and during the first 21 days of life, and in adult horse and pony sera. Intestinal ALP activity was not found in sera of any of the foals or adult ponies or horses. A majority of serum ALP activity of newborn foals is of bone origin (80 to 92%) which decreases markedly over the first 21 days. In adults, only 17.9% (51.2 +/- 18.1 U/L) of serum ALP is derived from bone. The absolute LALP activity in foal serum is similar to that in adults.

Safety of L-tryptophan for pigs.

Epidemic eosinophilia-myalgia syndrome (EMS) associated with excess L-tryptophan (Trp) consumption in humans has been declared a major public health problem. The EMS problem has not been observed in pigs, nor has comprehensive pathology associated with EMS in humans been described. Experiments were therefore conducted to evaluate the pathology and effects of excess dietary L-Trp for finishing (79 to 119 kg) pigs and to determine an LD50 of Trp for pigs. In Exp. 1, addition of .1 or 1% Trp to corn-soybean meal diets had no effect on growth performance or leukocyte and relative eosinophil counts or on plasma aspartate transferase, creatine phosphokinase, and lactate dehydrogenase activities. Likewise, untoward pathological effects of Trp feeding were not observed in the animals under study. In Exp. 2, supplementing the basal diet with 0, 2, and 4% Trp caused linear (P less than .05) decreases in weight gain, feed intake, and gain:feed ratio. Mortality could not be produced by acute oral dosing in the LD50 study (Exp. 3), wherein Trp doses between 2.00 and 5.71 g/kg of BW were administered by stomach tube. Vomiting occurred at oral doses greater than 5.71 g/kg of BW. These results suggest that oral ingestion of Trp in pigs is safe and that pigs can tolerate considerable excesses of Trp.

Extraction of aflatoxins from naturally contaminated peanuts with different solvents and solvent/peanut ratios.

A study was conducted to compare the extraction efficiencies of aflatoxins (B1, B2, G1, and G2) from low, medium, and high concentrations (approximately 10, 100, and 1000 ppb, respectively) of naturally contaminated peanut samples by using different solvents and solvent-to-peanut sample ratios. Solvents used were 80:20 methanol/water at 2:1, 3:1, and 5:1 solvent to sample ratios; 60:40 methanol/water at 5:1 solvent to sample ratio; and 90:10 acetonitrile/water at 2:1 and 4:1 solvent to sample ratios. The solvents 80:20 methanol/water at a 3:1 ratio of solvent to sample and 90:10 acetonitrile/water at a 2:1 ratio were consistently more efficient than all other solvents, regardless of the aflatoxin concentration. The solvent 90:10 acetonitrile/water at a 4:1 solvent-to-sample ratio was consistently the least efficient regardless of aflatoxin concentration based on analytical results with liquid chromatography (LC). The results are relevant in selecting an appropriate extraction solvent for use at peanut grading points.

Variability among peanut subsamples prepared for aflatoxin analysis with four mills.

The variability in aflatoxin concentration among peanut subsamples ground with 4 different mills was evaluated. Twenty 2 kg samples of naturally contaminated peanuts were ground in a Dickens subsampling mill (DM), a Stephan model UM-12 vertical cutter mixer (SM), and a Robot Coupe model RS16Y-1 vertical cutter mixer (RC1). Twenty 4 kg samples were ground in the DM, SM, and a Robot Coupe model R10P vertical cutter mixer (RC2). From each 2 kg sample, ten 100 g subsamples were withdrawn, and from each 4 kg samples, ten 200 g subsamples were withdrawn. Subsamples were analyzed for aflatoxin by liquid chromatography. The coefficient of variation (CV) among each set of 10 subsamples was determined for each sample, and the CVs for each sample size were ranked and analyzed by the Kruskal-Wallis test of ranks. For 2 kg samples, the CVs for the samples ground in RC1 ranked significantly lower than those for samples ground in DM and SM. For 4 kg samples, the CVs for samples ground in RC2 and SM were significantly lower than that for samples ground in DM. The averages of the CVs for 2 kg samples were 17.2% (RC1), 32.8% (SM), and 40.6% (DM). The averages of the CVs for 4 kg samples were 21.2% (RC2), and 26.0% (SM), and 47.0% (DM).

Immunoaffinity column as cleanup tool for a direct competitive enzyme-linked immunosorbent assay of cyclopiazonic acid in corn, peanuts, and mixed feed.

An immunoaffinity column (IAC) for cyclopiazonic acid (CPA) was prepared by coupling a CPA-specific monoclonal antibody to CNBr-activated sepharose 4B. A direct competitive enzyme-linked immunosorbent assay (dc-ELISA) was used to study the chromatographic behavior of a 0.2 mL gel column with a binding capacity of 4 micrograms CPA/column as well as to evaluate its efficacy as a cleanup tool for analysis of naturally occurring CPA. Sample extract either in buffer solution or in a solution containing up to 35% methanol could be loaded onto the column. After the column is washed with 5 mL deionized water and 5 mL 50% methanol, CPA could be quantitatively eluted with 2 mL 100% methanol. The column could be regenerated at least 10 times by washing with 10 mL equilibrating buffer and then storing in a cold room overnight before reuse. Recoveries of CPA added to corn, peanut, and mixed feed extracts in the range 10-200 ng/g were 88-105, 86-100, and 90-110%, respectively. Detection limits were 2.0, 4.4, and 4.7 ng/g for corn, mixed feed, and peanuts, respectively. Twenty-two peanut samples naturally contaminated with CPA were subjected to both IAC and solvent partition cleanup followed by dc-ELISA. Although a good correlation between data obtained from IAC-dc-ELISA and from SP-dc-ELISA (r = 0.75, p < 0.0001) was obtained, the slope of the linear regression was low (0.67), indicating loss during solvent partition cleanup. The overall data showed that the combination of IAC and dc-ELISA is an effective method for CPA analysis.

Performance of two immunochemical assays in the analysis of peanuts for aflatoxin at 37 field laboratories.

A study was conducted to measure the precision of 2 rapid aflatoxin assay systems in use at 37 peanut buying points during the 1991 harvest season. Aflatoxin laboratories were established at the 37 buying points to analyze peanut samples from all incoming farmers' stock loads as part of a joint project sponsored by various segments of the U.S. peanut industry and the U.S. Department of Agriculture. Eighteen laboratories were equipped with Neogen's veratox FSP rapid assay system, whereas 19 laboratories used Vicam's Aflatest rapid assay system. To monitor the performance of the field laboratories during the project, 3 portions of each of six 27 kg samples of ground peanuts were sent to each laboratory for analysis over a period of 6 weeks. Aflatoxin concentrations ranged from 0 to 300 ng/g when eight 200 g subsamples of each sample were analyzed by liquid chromatography (LC). For the 5 samples contaminated with aflatoxin, relative standard deviations for repeatability (RSDr) for laboratories using veratox FSP ranged from 18.66 to 53.29%, and the relative standard deviations for reproducibility (RSDR) ranged from 22.79 to 59.29%. For laboratories using the Aflatest system, RSDr values ranged from 18.70 to 41.48%, and RSDR values ranged from 23.84 to 47.56%. Horwitz ratios < 2.0 were found for 4 of the 5 contaminated samples for both methods, indicating that the overall precision of the 2 methods used in the project was good. Mean aflatoxin concentrations, as determined with the rapid assay systems, were generally lower than those determined by LC, particularly for more highly contaminated samples.(ABSTRACT TRUNCATED AT 250 WORDS)

Application of short-lived radionuclides in neutron activation analysis of biological and environmental samples.

The application of short-lived nuclides, especially in connection with the 6LiD-converter, in biological and environmental samples is demonstrated on I and Br determination in human urine, on I in pet food, and on the analysis of all the halogens in volcanic gases in a single activation. Trace element determination in lichens indicates polluted and unpolluted areas. The use of the .74-s 38mCl enables the rapid screening of great number of samples.

Estimating aflatoxin in farmers' stock peanut lots by measuring aflatoxin in various peanut-grade components.

Five, 2 kg test samples were taken from each of 120 farmers' stock peanut lots contaminated with aflatoxin. Kernels from each 2 kg sample were divided into the following grade components: sound mature kernels plus sound splits (SMKSS), other kernels (OK), loose shelled kernels (LSK), and damaged kernels (DAM). Kernel mass, aflatoxin mass, and aflatoxin concentration were measured for each of the 2400 component samples. For 120 lots tested, average aflatoxin concentrations in SMKSS, OK, LSK, and DAM components were 235, 2543, 11,775, and 69,775 ng/g, respectively. Aflatoxins in SMKSS, OK, LSK, and DAM components represented 6.9, 7.9, 33.3, and 51.9% of the total aflatoxin mass, respectively. Cumulatively, 3 aflatoxin risk components--OK, LSK, and DAM--accounted for 93.1% of total aflatoxin, but only 18.4% percent of test sample mass. Correlation analysis suggests that the most accurate predictor of aflatoxin concentration in the lot is the cumulative aflatoxin mass in the high 3 risk components OK + LSK + DAM (correlation coefficient, r = 0.996). If the aflatoxin in the combined OK + LSK + DAM components is expressed in concentration units, r decreases to 0.939. Linear regression equations relating aflatoxin in OK + LSK + DAM to aflatoxin concentration in the lot were developed. The cumulative aflatoxin in the OK + LSK + DAM components was not an accurate predictor (r = 0.539) of aflatoxin in the SMKSS component. Statistical analyses of 3 other data sets published previously yielded similar results.

Disappearance rates of intravenously injected canine alkaline phosphatase isoenzymes.

The serum half-life of various canine alkaline phosphatase isoenzymes has been determined. Isoenzymes can be divided into 2 groups with regard to their half-life. Isoenzymes with a half-life of approximately 3 days include the hepatic alkaline phosphatase and the steroid-induced alkaline phosphatase. Those with a half-life of under 6 minutes include the alkaline phosphatase from placenta, kidney, intestine, and the hepatic and steroid-induced iosenzymes after removal of sialic acid. The inability to demonstrate some of the isoenzymes of alkaline phosphatase in serum of diseases animals is attributed to their short half-life. The relationship of the short half-life to the sialic acid moiety of the protein is discussed.

Serum half-life of intravenously injected intestinal and hepatic alkaline phosphatase isoenzymes in the cat.

The serum half-life of feline intestinal alkaline phosphatase (ALP) in the cat was 2 minutes, and that of feline hepatic ALP, 5.8 hours. The feline hepatic ALP could not be identified in the urine of the cats, nor was the clearance rate affected by bilateral nephrectomy. These data indicated the shor serum half-life of hepatic ALP was not a reusult of renal excretion. Since canine hepatic ALP cleared from feline blood at the same rate as the feline hepatic ALP, possibly the discrepancy in hepatic ALP half-life between the species was related to the cats' ability to clear the blood of the enzyme.