Hyperspectral signals in the soil: Plant-soil hydraulic connection and disequilibrium as mechanisms of drought tolerance and rapid recovery.

Predicting soil water status remotely is appealing due to its low cost and large-scale application. During drought, plants can disconnect from the soil, causing disequilibrium between soil and plant water potentials at pre-dawn. The impact of this disequilibrium on plant drought response and recovery is not well understood, potentially complicating soil water status predictions from plant spectral reflectance. This study aimed to quantify drought-induced disequilibrium, evaluate plant responses and recovery, and determine the potential for predicting soil water status from plant spectral reflectance. Two species were tested: sweet corn (Zea mays), which disconnected from the soil during intense drought, and peanut (Arachis hypogaea), which did not. Sweet corn's hydraulic disconnection led to an extended 'hydrated' phase, but its recovery was slower than peanut's, which remained connected to the soil even at lower water potentials (-5 MPa). Leaf hyperspectral reflectance successfully predicted the soil water status of peanut consistently, but only until disequilibrium occurred in sweet corn. Our results reveal different hydraulic strategies for plants coping with extreme drought and provide the first example of using spectral reflectance to quantify rhizosphere water status, emphasizing the need for species-specific considerations in soil water status predictions from canopy reflectance.

Ulcerative Dermatitis in C57BL/6NCrl Mice on a Low-Fat or High-Fat Diet With or Without a Mineralized Red-Algae Supplement.

Ulcerative dermatitis (UD) is a spontaneous idiopathic disease that often affects C57BL/6 mice or mice on a C57BL/6 background. UD is characterized by intense pruritus and lesion formation, most commonly on the head or dorsal thorax. Self-trauma likely contributes to wound severity and delayed wound healing. Histologically, changes are nonspecific, consisting of ulceration with neutrophilic and mastocytic infiltration and epithelial hyperplasia and hyperkeratosis. Diet appears to have a profound effect on the development and progression of UD lesions. We investigated the incidence and severity of UD in C57BL/6NCrl mice on a high-fat western-style diet (HFWD) compared with a standard rodent chow. In addition, we examined the protective effects of dietary supplementation with a multimineral-rich product derived from marine red algae on UD in these 2 diet groups. HFWD-fed mice had an increased incidence of UD. In addition, mice on a HFWD had significantly more severe clinical and histologic lesions. Dietary mineral supplementation in mice on a HFWD decreased the histologic severity of lesions and reduced the incidence of UD in female mice in both diets. In conclusion, a high-fat western-style diet may potentiate UD in C57BL/6NCrl mice. Insufficient mineral supply and mineral imbalance may contribute to disease development. Mineral supplementation may be beneficial in the treatment of UD.

A multimineral natural product from red marine algae reduces colon polyp formation in C57BL/6 mice.

The goal of this study was to determine if a multimineral natural product derived from red marine algae could reduce colon polyp formation in mice on a high-fat diet. C57BL/6 mice were maintained for up to 18 mo either on a high-fat "Western-style" diet or on a low-fat diet (AIN 76A), with or without the multimineral-supplement. To summarize, colon polyps were detected in 22 of 70 mice (31%) on the high-fat diet but in only 2 of 70 mice (3%) receiving the mineral-supplemented high-fat diet (P < 0.0001). Colon polyps were detected in 16 of 70 mice (23%) in the low-fat group; not significantly different from high-fat group but significantly higher than the high-fat-supplemented group (P = 0.0006). This was in spite of the fact that the calcium level in the low-fat diet was comparable to the level of calcium in the high-fat diet containing the multimineral-product. Supplementation of the low-fat diet reduced the incidence to 8 of 70 mice (11% incidence). Taken together, these findings demonstrate that a multimineral natural product can protect mice on a high-fat diet against adenomatous polyp formation in the colon. These data suggest that increased calcium alone is insufficient to explain the lower incidence of colon polyps.

A multi-mineral natural product inhibits liver tumor formation in C57BL/6 mice.

C57BL/6 mice were maintained for up to 18 months on high-fat and low-fat diets with or without a multi-mineral supplement derived from the skeletal remains of the red marine algae Lithothamnion calcareum. Numerous grossly observable liver masses were visible in animals on the "western-style" high-fat diet sacrificed at 12 and 18 months. The majority of the masses were in male mice (20 out of 100 males versus 3 out of 100 females; p = 0.0002). There were more liver masses in animals on the high-fat diet than on the low-fat diet (15 out of 50 on high-fat versus 5 out of 50 on low-fat; p = 0.0254). The multi-mineral supplement reduced the number of liver masses in mice on both diets (3 out of 25 male mice in the low-fat diet group without the supplement versus 1 out of 25 mice with supplement; 12 of 25 male mice in the high-fat diet group without the supplement versus 3 of 25 mice with supplement [p = 0.0129]). Histological evaluation revealed a total of 17 neoplastic lesions (9 adenomas and 8 hepatocellular carcinomas), and 18 pre-neoplastic lesions. Out of eight hepatocellular carcinomas, seven were found in unsupplemented diet groups. Steatosis was widely observed in livers with and without grossly observable masses, but the multi-mineral supplement had no effect on the incidence of steatosis or its severity. Taken together, these findings suggest that a multi-mineral-rich natural product can protect mice against neoplastic and pre-neoplastic proliferative liver lesions that may develop in the face of steatosis.

Progression of ulcerative dermatitis lesions in C57BL/6Crl mice and the development of a scoring system for dermatitis lesions.

Ulcerative dermatitis (UD) is a common, spontaneous condition in mice with a C57BL/6 background. Although initial lesions may be mild, UD is a progressive disease that often results in ulcerations or debilitating fibrotic contractures. In addition, lesions typically are unresponsive to treatment. Euthanasia is often warranted in severe cases, thereby affecting study outcomes through the loss of research subjects. Because the clinical assessment of UD can be subjective, a quantitative scoring method and documentation of the likely time-frame of progression may be helpful in predicting when animals that develop dermatitis should be removed from a study. Such a system may also be helpful in quantitatively assessing success of various treatment strategies and be valuable to clinical laboratory animal veterinarians. In this 1.5-y, prospective cohort study, we followed 200 mice to monitor the development and course of UD. Mice were examined every 2 wk. A clinical sign (alopecia, pruritus, or peripheral lymphadenopathy) was not identified that predicted development of UD lesions in the subsequent 2-wk period. Once UD developed, pruritus, the character of the lesion (single or multiple crust, coalescing crust, erosion, or ulceration), and the size of the lesion were the only parameters that changed (increased) over the course of the disease. Pruritus was a factor in the rapid progression of UD lesions. We used these findings to develop a quantitative scoring system for the severity of UD. This enhanced understanding of the progression of UD and the quantitative scoring system will enhance the monitoring of UD.

Myeloid cell tissue factor does not contribute to venous thrombogenesis in an electrolytic injury model.

INTRODUCTION: Tissue factor (TF) is a potent initiator of the extrinsic coagulation cascade. The role and source of TF in venous thrombotic disease is not clearly defined. Our study objective was to identify the contribution of myeloid cell TF to venous thrombogenesis in mice. MATERIALS AND METHODS: The mouse electrolytic inferior vena cava model was used to induce thrombosis. The following groups of mice were used (1) TF(flox/flox)LysMCre(+) mice that have reduced TF expression in myeloid cells, (2) TF(flox/flox)LysMCre(-) littermate controls, (3) Wild type mice given a monoclonal anti-mouse TF antibody (1H1) to inhibit TF activity, and (4) Wild type mice given rat IgG. Evaluations at baseline, day 2, and day 6 post thrombosis included thrombus weight, vein wall inflammatory cell migration, vein wall TF mRNA, and plasma D-dimer levels. RESULTS: Inhibition of TF significantly decreased thrombus weight 2days post venous thrombosis. In contrast, TF(flox/flox)LysMCre(+) had no change in thrombus weight when compared to littermate controls. The absence of myeloid cell TF did not affect infiltration of neutrophils or monocytes into the vein wall. TF mRNA expression in the vein wall decreased at 2days but then returned to baseline levels by 6days post thrombosis. D-dimer levels peaked at 2days post thrombosis in mice with or without myeloid cell TF. CONCLUSIONS: TF is important in the formation of venous thrombi in the macrovasculature. However, TF expression by myeloid cells does not significantly contribute to venous thrombogenesis in this model.

Facial paralysis and lymphocytic facial neuritis in a rhesus macaque (Macaca mulatta) positive for simian retrovirus type D2.

Simian retrovirus type D (SRVD) is a naturally occurring betaretrovirus in nonhuman primates of the genus Macaca. Infection can lead to a variety of clinical, hematologic, and histopathologic abnormalities. We report an unusual clinical presentation of facial paralysis and histologic lymphocytic neuritis in an SRVD type 2 (SRVD2)-infected rhesus macaque (Macaca mulatta) with a catheter-associated vena caval thrombus, anemia, thrombocytopenia, and multisystemic lymphoid hyperplasia. At initial presentation, a right atrial mass was detected by echocardiography. The macaque was clinically asymptomatic but had persistent anemia, thrombocytopenia, hyperglobulinemia, and later neutropenia. It was seropositive for SRV and PCR-positive for SRVD 2. Approximately 1 mo after initial presentation, the macaque developed right facial paralysis and was euthanized. Histologic lesions included lymphoplasmacytic aggregates affecting multiple organs, consistent with SRV-related lymphoid hyperplasia. The right facial nerve showed lymphoplasmacytic inflammation. The nerve itself was negative immunohistochemically for SRV antigen, but antigen was present infrequently in pericapillary lymphoid cells within the facial nerve and abundantly within lymphoid aggregates in the adjacent parotid salivary gland, bone marrow, and soft tissue. Known neurotropic viruses could not be identified. Given the widespread inflammation in this macaque, particularly in the area surrounding the facial nerve, lymphocytic neuritis and facial paralysis likely were an indirect effect of SRV infection due to local extension of SRV-related inflammation in the surrounding tissue.

Evaluation of a porcine zona pellucida vaccine for the immunocontraception of domestic kittens (Felis catus).

With a seasonally polyestrus breeding structure, the unwanted domestic cat population has proven difficult to control. Various lethal methods have been used in an attempt to lower this population of cats. Recently, humane attempts to control "pest species," such as the feral cat, have focused on immunocontraception. SpayVacTM is a vaccine that uses antibodies raised against porcine (ZP) antigens to prevent fertilization of the ovum. SpayVac, delivered in a single dose, has been evaluated in fallow deer and several species of seals with >90% reduction in fertility and no adverse reactions. This study evaluated the effectiveness of SpayVac in reducing fertility in domestic kittens. Thirty female kittens were treated with SpayVac containing either Freund's complete adjuvant (FCA) or alum, or with a control vehicle. Kittens were monitored for side effects, estrus cycling at maturity, and fecundity. Anti-porcine ZP antibodies were quantified by ELISA. Immunohistochemical assays measured the species specificity of the antibodies produced and IgG binding in vivo. Despite high anti-porcine ZP antibody titers, neither formulation of SpayVac prevented estrus cycling at maturity or reduced fecundity. Immunohistochemical assays indicated that antibodies produced by cats treated with SpayVac recognized porcine ZP, but not feline ZP.