Observational study on dry period length and its associations with milk production, culling risk, and fertility in Italian dairy farms.

From an initial data set involving 84,189 lactations, this research evaluated the relationship between dry period length (DPL) and milk production, culling risk, and fertility. The data set included a total of 48,297 multiparous cow lactation records, with a calving event occurring in 2019 and 2020, belonging to 62 Italian herds with at least 150 cows. The DPL was classified into 5 categories (<40, 40-49, 50-60, 61-70, and >70 d) and these categories were used to establish the association between DPL and the outcome variables. All data obtained were assessed with simple and multiple linear regressions and Cox proportional hazard models. Cumulative milk production at 60 d in milk (DIM) was the highest in DPL categories of 61 to 70 d (2,480.29 kg/cow) and 50 to 60 d (2,474.39 kg/cow), and the lowest in <40 d (2,281.29 kg/cow). Similarly, DPL categories 61 to 70 d (10,830.94. kg/cow) and 50 to 60 d (10,817.48 kg/cow) had the highest 305-d milk production, whereas the <40 d (10,200.96 kg/cow) had the lowest one. The groups with a DPL of 40 to 49 d and >70 d had slightly, but significant, lower milk production both as cumulative 60 DIM and predicted 305-d milk production. Culling risk had a curvilinear behavior, with DPL <40 d and DPL >70 d showing significantly higher odds for culling during the first 60 DIM compared with DPL of 50 to 60 d [relative risk (RR): 1.53; RR: 1.46]. Within the same comparison, DPL of 61 to 70 d also had a slightly higher risk for culling (RR: 1.13). The DPL was associated also with fertility, with DPL of 40 to 49 d and 50 to 60 d having the greatest odds for pregnancy within the first 200 DIM. The DPL of <40, 61 to 70, and >70 d were negatively associated with fertility and showed pregnancy risks of 0.87, 0.95, and 0.94, respectively. This paper reinforces the importance of DPL as we demonstrated its association with milk production, culling, and fertility. Despite being attractive for high production dairy cows, very short dry periods are at the same time also associated with higher culling risk, lower milk production and fertility. Long DPL is detrimental, especially regarding culling and fertility. In summary, reducing variability in DPL and avoiding extremes by improving reproductive performance, maximizing late lactation milk production and making wise decisions on dry-off timing, may lead to better performances and lower early culling under Italian dairy conditions.

Taste and smell in aquatic and terrestrial environments.

Covering: up to 2017The review summarizes results up to 2017 on chemosensory cues occurring in both aquatic and terrestrial environments. The chemicals are grouped by their physicochemical properties to compare their potential mobility in the different media. In contrast to what is widely asserted in the literature, the report emphasizes that living organisms encounter and sense molecules of various degrees of solubility and volatility both on land and in aquatic environments. The picture that emerges from the review suggests a substantial revision of the traditional definitions of the chemical senses based on their spatial range, which is currently orienting the literature on chemosensory signaling, in favor of a new vision based on the natural products that are the actual mediators of the chemosensory perceptions. According to this perspective, natural product chemistry is a powerful tool with which to explore the evolutionary history of the chemical senses.

2-pentadecyl-2-oxazoline prevents cognitive and social behaviour impairments in the Amyloid ß-induced Alzheimer-like mice model: Bring the α2 adrenergic receptor back into play.

The 2-pentadecyl-2-oxazoline (PEA-OXA) is a natural compound with protective action in neuro-inflammation. We have previously shown that PEA-OXA behaves as an α2 adrenergic receptor (α2AR) antagonist and a putative protean agonist on histamine H3 receptors. Recently, neuroinflammation and monoaminergic neurotransmission dysfunction has drawn particular attention in Alzheimer Disease (AD) pathophysiology. In this context, the objective of this study was to investigate the effects of the dual-acting PEA-OXA in an AD-like model in mice. A combined computational and experimental approach was used to evaluate the ability of PEA-OXA to bind α2A-AR subtype, and to investigate the effects of PEA-OXA treatment on neuropathological (behavioural and functional) effects induced by soluble Amyloid ß 1-42 (sAß1-42) intracerebroventricular injection. Computational analysis revealed the PEA-OXA ability to bind the α2A-AR, a pharmacological target for AD, in two alternative poses, one overlapping the Na+ binding site. In vivo studies indicated that chronic treatment with PEA-OXA (10 mg/kg, os) restored the cognitive (discriminative and spatial memory) deficits and social impairments induced by sAß injection. Consistently, electrophysiological analysis showed a recovery of the long-term potentiation in the hippocampus (Lateral Entorhinal Cortex-Dentate Gyrus pathway), while neuroinflammation, i.e., increased pro-inflammatory cytokines levels and microglia cells density were reduced. These data provide the basis for further investigation of the pro-cognitive aptitude of PEA-OXA by proposing it as an adjuvant in the treatment in AD, for which the available pharmacological approaches remain unsatisfactory. Moreover, this study offers new future direction in research investigating the role of α2AR in neuropsychiatric illness and therapies.

A new triple-stranded alpha-helical bundle in solution: the assembling of the cytosolic tail of MHC-associated invariant chain.

BACKGROUND: The invariant chain (li) is a transmembrane protein that associates with the major histocompatibility complex class II (MHC II) molecules in the endoplasmic reticulum. The cytosolic tail of li contains two leucine-based sorting motifs and is involved in sorting the MHC II molecules to the endosomal pathway where the peptide antigen is bound. This region of li also contributes to phenotypical changes in cells, such as the formation of large endocytic structures. RESULTS: We report here the three-dimensional structure of a 27 amino acid peptide corresponding to the cytosolic tail of li. The structure was determined by nuclear magnetic resonance (NMR) spectroscopy using a computational strategy. At high concentration, this structure reveals a new triple-stranded alpha-helical bundle in which the helices, two parallel and one antiparallel, are almost coplanar. Trimerization is mediated by electrostatic interactions intercalated by three hydrophobic layers. CONCLUSIONS: The new trimer fold, the first to be identified by NMR data alone, can be used to improve understanding of protein-protein interactions and to model multiple-helical transmembrane proteins and receptors. We suggest that interactions of the li cytosolic tails may form part of a mechanism that could cause the endosomal retention and enlarged endosomes induced by li.

Modularity and homology: modelling of the titin type I modules and their interfaces.

Titin is a giant muscle protein with a highly modular architecture consisting of multiple repeats of two sequence motifs, named type I and type II. Type I motifs are homologous to members of the fibronectin type 3 (Fn3) superfamily, one of the motifs most widespread in modular proteins. Fn3 domains are thought to mediate protein-protein interactions and to act as spacers. In titin, Fn3 modules are present in two different super-repeated patterns, likely to be involved in sarcomere assembly through interactions with A-band proteins. Here, we discuss results from homology modelling the whole family of Fn3 domains in titin. Homology modelling is a powerful tool that will play an increasingly important role in the post-genomic era. It is particularly useful for extending experimental structure determinations of parts of multidomain proteins that contain multiple copies of the same motif. The 3D structures of a representative titin type I domain and of other extracellular Fn3 modules were used as a template to model the structures of the 132 copies in titin. The resulting models suggest residues that contribute to the fold stability and allow us to distinguish these from residues likely to have functional importance. In particular, analysis of the models and mapping of the consensus sequence onto the 3D structure suggest putative surfaces of interaction with other proteins. From the structures of isolated modules and the pattern of conservation in the multiple alignment of the whole titin Ig and Fn3 families, it is possible to address the question of how tandem modules are assembled. Our predictions can be validated experimentally.

Kinase recognition by calmodulin: modeling the interaction with the autoinhibitory region of human cardiac titin kinase.

Calmodulin (CaM)-protein interactions are usually described by studying complexes between synthetic targets of ca 25 amino acids and CaM. To understand the relevance of contacts outside the protein-binding region, we investigated the complex between recombinant human CaM (hCaM) and P7, a 38-residue peptide corresponding to the autoinhibitory domain of human cardiac titin kinase (hTK). To expedite the structure determination of hCaM-P7 we relied upon the high degree of similarity with other CaM-kinase peptide complexes. By using a combined homonuclear NMR spectroscopy and molecular modeling approach, we verified for the bound hCaM similar trends in chemical shifts as well as conservation of NOE patterns, which taken together imply the conservation of CaM secondary structure. P7 was anchored to the protein with 52 experimental intermolecular contacts. The hCaM-P7 structure is very similar to known CaM complexes, but the presence of NOE contacts outside the binding cavity appears to be novel. Comparison with the hTK crystal structure indicates that the P7 charged residues all correspond to accessible side-chains, while the putative anchoring hydrophobic side-chains are partially buried. To test this finding, we also modeled the early steps of the complex formation between Ca(2+)-loaded hCaM and hTK. The calculated trajectories strongly suggest the existence of an "electrostatic funnel", driving the long-range recognition of the two proteins. On the other hand, on a nanosecond time scale, no intermolecular interaction is formed as the P7 hydrophobic residues remain buried inside hTK. These results suggest that charged residues in hTK might be the anchoring points of Ca(2+)/hCaM, favoring the intrasteric regulation of the kinase. Furthermore, our structure, the first of CaM bound to a peptide derived from a kinase whose three-dimensional structure is known, suggests that special care is needed in the choice of template peptides to model protein-protein interactions.

Topology of the calmodulin-melittin complex.

The topology of the Ca2+-calmodulin-melittin ternary complex has been investigated by a combined strategy which integrates limited proteolysis and cross-linking experiments with mass spectrometric methodologies. The rationale behind the methods is that the interface regions of two interacting proteins are accessible to the solvent in the isolated molecules, whereas they become protected following the formation of the complex. Therefore, when limited proteolysis experiments are carried out on both the isolated proteins and the complex, differential peptide maps are obtained from which the interface regions can be inferred. Alternatively, cross-linking reactions performed under strictly controlled conditions lead to the identification of spatially closed amino acid residues in the complex. Mass spectrometry can be employed in both procedures for the definition of the cleavage sites and to identify covalently linked residues. Our results show that melittin interacts with calmodulin by adopting a parallel orientation, i.e. the N and C-terminal halves of the peptide are anchored to the amino and carboxy-terminal domains of the protein, respectively. This orientation is inverted with respect to all the peptide substrates examined so far. A model of the complex was designed and refined on the basis of the experimental results, supporting the above conclusions. This finding reveals a further dimension to the already remarkable capability of calmodulin in binding different protein substrates, providing this protein with the capability of regulating an even larger number of enzymes.

Structural determination of the active site of a sweet protein. A 1H NMR investigation of pMNEI.

pMNEI, a single chain sweet protein related to monellin, has been studied by means of 1H NMR at 500 MHz. A partial sequential assignment performed by means of the MCD method allowed the determination of the secondary structure of a large portion of the beta-sheet of pMNEI that contains a likely 'sweet finger': the loop connecting the beta-strands from residue 59 to residue 78, corresponding to segment 16-35 of the A chain of monellin. The detailed three-dimensional structure of the loop (Tyr66-Ala67-Ser68-Asp69), determined from several interresidue and intraresidue NOEs and subsequent energy minimization, shows that the side chains of Tyr66 and Asp69 fit our model of the sweet receptor in a manner very similar to that of the side chains of Phe and Asp of aspartame.

Pain peptides. Solution structure of orphanin FQ2.

Orphanin FQ2 (OFQ2) is a novel heptadecapeptide generated from prepronociceptin (PPNOC), the same precursor of nociceptin/orphanin FQ and nocistatin. OFQ2 is a potent analgesic when administered both supraspinally and spinally. In order to clarify the structural relationship with all peptides generated from PPNOC, we have undertaken the conformational study of OFQ2 in water and in structure-promoting solvent media. Nuclear magnetic resonance data and theoretical calculations are consistent with a well defined helical structure from Met(5) to Ser(16). The uniform distribution of hydrophobic residues along the helix suggests that OFQ2 may interact with the transmembrane helices of a receptor akin to those of nociceptin and opioids.

Design of mu selective opioid dipeptide antagonists.

We have recently designed potent delta selective opioid antagonist dipeptides on the basis of a simple conformational analysis. Following a similar procedure we found a mu selective dipeptide antagonist, 2,6-dimethyl-Tyr-D-Phe-NH2. Although its selectivity is not as high as those of the quoted delta selective dipeptides it has good in vitro activity and looks very promising for further development since the 2,6-dimethyl-Tyr-D-Phe message, like the delta selective 2,6-dimethyl-Tyr-1,2,3,4-tetrahydroisoquinoline-3-carboxylic acid counterpart, seems able to impart antagonism to longer peptides.

Conformational analysis of potent and very selective delta opioid dipeptide antagonists.

The delta selectivity and antagonism of peptides containing L-tetrahydro-3-isoquinoline carboxylic acid (Tic) in second position can be attributed mainly to the Tyr-Tic unit. These properties can be further enhanced by substituting Tyr1 with 2,6-dimethyl-L-tyrosyl (Dmt). Dmt-Tic-NH2, Dmt-Tic-OH, Dmt-Tic-Ala-NH2 and Dmt-Tic-Ala-OH are all more active and/or selective than the corresponding [Tyr1]-parent peptides. In fact the selectivities of Dmt-Tic-OH and Dmt-Tic-Ala-OH are the highest ever recorded for opioid molecules. 1H NMR spectra in a DMSO/water mixture at 278 K reveal the presence of two similar conformers, characterised by a cis or trans Dmt-Tic bond, in all four peptides. A detailed conformational analysis in solution of Dmt-Tic-NH2 shows that these conformers have a shape very similar to that of the bioactive conformation of Tyr-Tic-NH2 and to that of naltrindole.

Circulating platelet aggregates in an adult population sample. Relationships with the main coronary risk factors and cardiovascular diseases.

We have determined the reversible circulating platelet aggregates (CPA) in a sample taken from the general population (414 consecutive individuals of both sexes, aged 20--60 years), examined during the initial screening of a multifactor primary prevention trial for coronary heart disease. Our findings show that in the overall population, less than 10% of circulating platelets occur as reversible aggregates. No differences were observed with regard to sex, age or presence of non-acute cardiovascular disease. No significant correlations were found between the extent of CPA and the main coronary risk factors.

Individual serum bile aids in patients with primary hyperlipoproteinemias.

Fasting serum concentrations of the individual bile acids were measured by gas chromatography in 27 patients with primary hyperlipoproteinemia (8 type IIa, 7 type IIb and 12 type IV) and in 14 healthy subjects. Total serum bile acid levels were 1618 +/- 244 ng/ml (SE) in type IIa, 1296 +/- 251 ng/ml in type IIb and 15609 +/- 263 ng/ml in type IV hyperlipoproteinemia. These values did not differ significantly from values in the control group (1505 +/- 200 ng/ml). Serum levels of cholic acid were significantly higher in patients with type IIa (551 +/- 78 ng/ml) than in those with type IIb (190 +/- 57 ng/ml, P < 0.01) and type IV (240 +/- 57 ng/ml, P < 0.02), while intermediate values were recorded in the control group (384 +/- 49 ng/ml). Ursodeoxycholic acid was found in larger amounts in hyperlipidemic patients than in controls. No significant differences with respect to other bile acids were observed between the groups examined. According to the current concepts on the enterohepatic circulation of bile acids, the findings support the hypothesis that the intestinal absorption of cholic acid may differ in various types of hyperlipoproteinemia.

Comparative tissue reactivity to topical hemostatic agents in the periureteral area.

Application of the topical hemostatic agents microfibrillar collagen hemostat (Avitene), oxidized cellulose (Surgicel), and absorbable gelatin sponge (Gelfoam) to the periureteral regions in dogs did not incite an adverse inflammatory or fibrotic reaction when used in standard, recommended fashion. No instances of ureteral obstruction resulted from such application. The addition of a small amount of sterile urine in the same area with the topical agent did not influence the degree of reaction. We concluded that these useful hemostatic agents, when used properly, are absorbed with only slight or no residual tissue reaction. The adverse tissue reaction occasionally reported probably can be ascribed to either improper use of the hemostatic agent, other concomitant noxious influences such as infection, or admixture with abnormal collections of body fluids.

Melanosis coli. Changes in appearance when associated with colonic neoplasia.

In 30 cases of colonic neoplasia associated with melanosis coli, proliferating or neoplastic colonic epithelium was notable within the melanotic colons by virtue of a striking absence of pigmentation. Microscopically this characteristic was found to be due to an absence or diminution of pigment-laden macrophages in the lamina propria underlying such lesions. Therefore, the absence of pigment-laden macrophages can be considered a marker for abnormally proliferating epithelium. This characteristic may denote a cellular or humoral change mediated by macrophages in association with neoplastic epithelium.

Red blood cell fatty acid composition in a sample of Italian middle-aged men on free diet.

Within the framework of a project of primary prevention of coronary heart disease the erythrocyte fatty acid composition was determined in 140 Italian middle-aged men on free diet. The linoleic/oleic ratio ranged from 0.27 to 0.96 pointing out remarkable differences in dietary fat intake. A negative correlation was observed between erythrocyte linoleic/oleic ratio and plasma cholesterol levels. This gives indirect support to the validity of this ratio as an index of adherence to cholesterol-lowering diets in long-term studies.

Effect of preoperative irradiation on healing of low colorectal anastomoses.

The effect of preoperative irradiation on the healing of low colorectal anastomoses was studied experimentally. In 12 dogs in whom preoperative irradiation of 4,000 rads was given before low colorectal stapled anastomosis was performed, anastomotic leakage occurred in 66 percent. More than half of the anastomotic leaks were associated with either severe sepsis or death. In a matched group of control animals that underwent stapled anastomoses without irradiation, no anastomotic complications occurred. The clinical implications of this study are that stapled anastomoses in irradiated colon are at serious risk of anastomotic dehiscence and, therefore, should be protected with a proximal colostomy.

Modulation of aldose reductase activity through S-thiolation by physiological thiols.

The glutathionyl-modified aldose reductase (GS-ALR2) is unique, among different S-thiolated enzyme forms, in that it displays a lower specific activity than the native enzyme (ALR2). Specific interactions of the bound glutathionyl moiety (GS) with the ALR2 active site, were predicted by a low perturbative molecular modelling approach. The outcoming GS allocation, involving interactions with residues relevant for catalysis and substrate allocation, explains the rationale behind the observed differences in the activity between GS-ALR2 and other thiol-modified enzyme forms. The reversible S-glutathionylation of ALR2 observed in cultured intact bovine lens undergoing an oxidative/non oxidative treatment cycle is discussed in terms of the potential of ALR2/GS-ALR2 inter-conversion as a response to oxidative stress conditions.

Effects of choledochojejunostomy with Roux-en-Y exclusion on dimethylhydrazine induced neoplasms in rats.

The role of biliary secretions was studied in the development of neoplasms in the small intestine and colon of rats treated with 1,2-dimethylhydrazine (DMH). Sixty-eight female Sprague-Dawley rats underwent either no operative procedure or choledochojejunostomy with or without a Roux-en-Y exclusion. All animals then received weekly subcutaneous injections of DMH at 20 mg/kg for 26 weeks and were subsequently sacrificed. The largest number of neoplasms was found in the proximal duodenum, within 3 cm distal to the pylorus, in the control as well as both operative groups. In addition, only six neoplasms developed in relation to the choledochojejunostomy site in rats undergoing choledochojejunostomy only, and no neoplasms were noted at this location in the animals undergoing choledochojejunostomy with Roux-en-Y exclusion. These results suggest that the distribution of enteric neoplasms in DMH treated rats does not depend on excretion of active carcinogen in bile.