Association of milk components with intra-mammary inflammation in Jaffrabadi buffaloes.

AIM: To study the alteration of major milk components such as milk fat, protein, lactose, solid not fat (SNF) and total solids (TS) and their association with different degree of intra-mammary inflammation (IMI) in Jaffrabadi buffaloes. MATERIALS AND METHODS: Milk samples (n=1516) were collected from Jaffrabadi buffaloes separately from each quarter. Milk samples were analyzed for milk fat, protein, lactose, SNF and TS percent on the same day using milk analyzer "LACTOSCAN." Milk samples were checked for IMI by California mastitis test (CMT), and the results were expressed as negative (0), +, ++, and +++ CMT score. The traits of milk components which showed significant difference (p<0.05) between samples from inflamed and non-inflamed quarters were analyzed by receiver operating characteristic (ROC) analysis to see the accuracy and degree of association with IMI. RESULTS: Among several milk components, milk protein and lactose percent showed a significant difference (p<0.05) between milk samples from normal and inflamed quarters. Though, during the early stage of mammary gland inflammation milk protein percent remained significantly high (p<0.05), later with an increase in the degree of severity of inflammation it did not show any difference. Milk samples from normal udder quarters had significantly higher lactose percent than inflamed quarters (p<0.05). Milk lactose percent decreased gradually with an increase in the degree of severity of inflammation. ROC analysis revealed that milk samples having lactose content below the threshold values had significantly higher chances to come from inflamed udder quarters (p<0.05). Though, the value of the area under curve (AUC) indicated that milk lactose was significantly associated with IMI (p<0.05), the accuracy was moderate (AUC=0.71-0.75). CONCLUSIONS: The results of the present study indicated that milk lactose percent gradually and significantly reduced during IMI and can be used as a marker for identification of IMI in buffaloes. However, ROC analysis further confirmed that using milk lactose IMI can be identified with moderate accuracy.

Panoramic-based mandibular indices and bone mineral density of femoral neck and lumbar vertebrae in women.

OBJECTIVE: The aim of this cross-sectional analytic study was to evaluate the diagnostic efficacy of panoramic-based indices of the mandible (Mental Index-MI, Mandibular Cortical Index-MCI and Panoramic Mandibular Index-PMI) and to determine their correlation with bone mineral density (BMD) of the femoral neck and lumbar vertebrae (L2-L4) in order to assess the possibility of using these parameters as indicators of osteoporosis. MATERIALS AND METHODS: The mandibular indices of 67 women over 35 years old were measured from panoramic radiographs, and bone densitometry was performed in the femoral neck and lumbar vertebrae (L2-L4), using DXA (Dual Energy X-ray Absorptiometry) technique. The patients were divided into three categories of normal, osteopenic and osteoporotic in each skeletal region. One-way ANOVA and ROC curve analyses were applied. The results were considered statistically significant when the P-value was less than 0.05. RESULTS: Comparing the mean BMD in the femoral neck in women between C1 and C3 subgroups of MCI, a significant difference was detected (P=0.04). The mean PMI in the three skeletal subgroups was not different according to the skeletal region (P>0.05). We found a significant difference in mean MI between normal and osteopenic subgroups in the femoral neck (P=0.042). CONCLUSION: Using radiomorphometric indices of the mandible (MCI-MI) may be useful in determining the skeletal status of the patients, but is not sufficient for precise evaluation.

Insulin signal transduction in rat small intestine: role of MAP kinases in expression of mucosal hydrolases.

The postreceptor events regulating the signal of insulin downstream in rat intestinal cells have not yet been analyzed. Our objectives were to identify the nature of receptor substrates and phosphorylated proteins involved in the signaling of insulin and to investigate the mechanism(s) by which insulin enhances intestinal hydrolases. In response to insulin, the following proteins were rapidly phosphorylated on tyrosine residues: 1) insulin receptor substrates-1 (IRS-1), -2, and -4; 2) phospholipase C-isoenzyme-gamma; 3) the Ras-GTPase-activating protein (GAP) associated with Rho GAP and p62(Src); 4) the insulin receptor beta-subunit; 5) the p85 subunits of phosphatidylinositol 3-kinase (PI 3-kinase); 6) the Src homology 2 alpha-collagen protein; 7) protein kinase B; 8) mitogen-activated protein (MAP) kinase-1 and -2; and 9) growth receptor-bound protein-2. Compared with controls, insulin enhanced the intestinal activity of MAP kinase-2 and protein kinase B by two- and fivefold, respectively, but did not enhance p70/S6 ribosomal kinase. Administration of an antireceptor antibody or MAP-kinase inhibitor PD-98059 but not a PI 3-kinase inhibitor (wortmannin) to sucklings inhibited the effects of insulin on mucosal mass and enzyme expression. We conclude that normal rat enterocytes express all of the receptor substrates and mediators involved in different insulin signaling pathways and that receptor binding initiates a signal enhancing brush-border membrane hydrolase, which appears to be regulated by the cascade of MAP kinases but not by PI 3-kinase.

Saccharomyces boulardii upgrades cellular adaptation after proximal enterectomy in rats.

BACKGROUND: Saccharomyces boulardii is a non-pathogenic yeast which exerts trophic effects on human and rat small intestinal mucosa. AIMS: To examine the effects of S boulardii on ileal adaptation after proximal enterectomy in rats. METHODS: Wistar rats, aged eight weeks, underwent 60% proximal resection or transection and received by orogastric intubation either 1 mg/g body wt per day lyophilised S boulardii or the vehicle for seven days. The effects on ileal mucosal adaptation were assessed eight days after surgery. RESULTS: Compared with transection, resection resulted in mucosal hyperplasia with significant decreases in the specific and total activities of sucrase, lactase, and maltase. Treatment of resected animals with S boulardii had no effect on mucosal hyperplasia but did upgrade disaccharidase activities to the levels of the transected group. Enzyme stimulation by S boulardii was associated with significant increases in diamine oxidase activity and mucosal polyamine concentrations. Likewise, sodium dependent D-glucose uptake by brush border membrane vesicles, measured as a function of time and glucose concentration in the incubation medium, was significantly (p<0.05) increased by 81% and three times respectively in the resected group treated with S boulardii. In agreement with this, expression of the sodium/glucose cotransporter-1 in brush border membranes of resected rats treated with S boulardii was enhanced twofold compared with resected controls. CONCLUSION: Oral administration of S boulardii soon after proximal enterectomy improves functional adaptation of the remnant ileum.

Premature stimulation of rat sucrase-isomaltase (SI) by exogenous insulin and the analog B-Asp10 is regulated by a receptor-mediated signal triggering SI gene transcription.

The mechanism(s) by which insulin enhance prematurely the activity of brush border membrane (BBM) hydrolases in rat immature intestine is unknown. Therefore, we have compared the responses of four BBM enzymes [sucrase-isomaltase (SI), maltase, lactase-phloridzine hydrolase (LPH), and aminopeptidase] with exogenous insulin, the analog B-Asp10, IGF-I, and antireceptor MAb [insulin-receptor (IR) MAb] given to preweaning pups. Low doses of insulin caused a precocious induction of SI and of SI mRNA and stimulated maltase activity without effect on LPH nor on aminopeptidase activities. IGF-I given at the same dose as that of insulin had no detectable effect on these enzymes. Administration to sucklings of IR MAb prevented the effect of endogenous insulin by inhibiting the expression of SI and maltase without effect on LPH activity. B-Asp10, an insulin analogue that exhibits in vitro a 3.5-fold increase in receptor affinity with sustained signaling of the receptor tyrosine kinase, caused an overexpression of SI by 3.5-fold and of maltase by 1.5-fold compared with equivalent doses of normal insulin. The premature increases in SI activity, SI mRNA, and maltase activity in response to insulin were dose-dependent and were associated with dose-dependent increases in intracellular spermine and spermidine concentrations. In conclusion, these data suggest that the premature induction of SI by insulin is mediated by a dose-dependent signal initiated by binding of the hormone to its intestinal receptor, which after transduction into the cell indirectly triggers the transcription of the SI gene, possibly by changes in intracellular polyamine concentrations.

Expression of insulin receptors and of 60-kDa receptor substrate in rat mature and immature enterocytes.

The mechanism(s) by which rat immature enterocytes exhibit increased responsiveness to insulin before weaning is unknown. Therefore, we have analyzed the distribution, ontogeny, and molecular properties of insulin receptors (IR) and of related substrates in immature and mature enterocytes. IR were studied by radioligand binding assays, cross-linking labeling, immunohistochemistry, and in vitro phosphorylated substrates by immunoprecipitation. Regardless of age, 125I-insulin binding to IR was five times higher in crypt cells than in villus cells and two times higher in the ileum than in the jejunum. Binding capacity to villus cells from sucklings (day 14) exceeded three times that of older animals (day 30 and day 60). Scatchard analysis of equilibrium binding data confirmed an age-related decrease in low- and high-affinity receptor classes without change in affinity constants. In concordance, both alpha- and beta-IR subunits were more abundant in immature than in mature membranes. In vitro, insulin elicited the phosphorylation of three membrane proteins (96, 60 and 42 kDa), whose signals were virtually inhibited by preincubating membranes with antireceptor monoclonal antibodies. By immunoprecipitation, the 60-kDa signal was rapidly detected as a tyrosine-phosphorylated protein, expressed in mature and immature membranes, and identified as a receptor substrate phosphorylated in vitro by the IR tyrosine kinase. In conclusion, 1) increased responsiveness of rat immature enterocytes to insulin could be related to high membrane concentrations of IR and 2) normal rat enterocytes express a 60-kDa phosphotyrosine protein identified as a direct substrate of the IR tyrosine kinase.