Wooden hoof blocks: are we using the right wood?

AIMS: To investigate the association between the density of wooden hoof blocks and resistance to wear in pasture-based dairy herds, and to assess the density of commercially available wooden hoof blocks. METHODS: Three types of wooden hoof blocks with different densities (low, medium and high) were attached to 36 lactating dairy cows with parity ≤2 and sound locomotion (score ≤2 on a scale of 1-4). The height of wooden blocks was measured in three different regions, front, abaxial and caudal on Days 7, 11, 14, 18, 21, 25 and 28 after application. Due to the loss of low-density wooden blocks, the data for these blocks were analysed for only two measurements on Days 7 and 11. The data for medium and high-density wooden blocks were analysed from Days 7-25. A linear mixed model with repeated measures was used to analyse the repeated observations. Height, density and surface area of commercially available hoof blocks (n = 19) were measured and compared to the blocks used in this study. RESULTS: The magnitude of wear, in the front and the abaxial point of the blocks were greater in blocks made of low-density wood compared to those made of medium and high-density wood (p < 0.001). The amount of wear increased over time for all groups (p < 0.001). Wood density was negatively associated with wear and loss. Measurements of commercial wooden blocks revealed that the 13/19 (63%) had lower density and 12/19 (68%) less surface area than the wooden blocks with medium density used in this study. CONCLUSION: In this study, the density of the wood was significantly associated with the longevity of hoof blocks when applied to hooves of pasture-based dairy cows. CLINICAL RELEVANCE: The longevity of the wooden hoof blocks applied to treat lame cows plays a significant role in the healing of the claw horn lesions. The density of a wooden hoof block affects the rate of wear of the block, and this should be considered by manufacturers and those treating lame cows.

Gut Microbiota as a Target in the Pathogenesis of Metabolic Disorders: A New Approach to Novel Therapeutic Agents.

As the prevalence of metabolic disorders increases dramatically, the importance of identifying environmental factors affecting metabolism control becomes greater accordingly. Gut microbiota, a complex ecosystem inhabiting the human gastrointestinal tract, is one of these potential factors. Recently, the evidence has shown the associations between alteration in gut microbiota composition and obesity, diabetes, and osteoporosis. However, the causality of gut microbiota on metabolic health has yet to be explored in intervention studies and the underlying mechanisms need to be investigated more in depth. Gut microbiota plays critical roles in the control of immunity, food intake, lipid accumulation, production of short chain fatty acids, insulin signaling, and regulation of bone mass. The gut microbiota represents a novel potential therapeutic strategy for the treatment of metabolic disorders. In this review, we provide insights into the role of the gut microbiota in metabolic disorders and its modulating interventions such as prebiotics, probiotics, and fecal microbiota transplantation.

Identifying risk factors associated with lameness in pasture-based dairy herds.

Lameness is a significant welfare concern for dairy farmers and a major contributing economic loss to the dairy industry. Information is limited on environmental and managerial risk factors associated with lameness in Australian dairy herds. The objective of this study was to explore and quantify the environmental and management risk factors associated with lameness in pasture-based dairy herds. A cross-sectional study was conducted in 63 pasture-based dairy herds between 2011 and 2014, where all lactating cows were locomotion scored (scale 1-4) during a single visit. Environmental and management variables, such as length of main track and animal handling practices, were recorded during the visit. The prevalence of lameness was measured for each farm and associated risk factors were analyzed using a Generalized Linear Model, where farm was the unit of analysis. Estimated average prevalence of lameness was 18.9% (range 5 to 44.5%). The prevalence of lameness was associated with the amount of rainfall during the 30 d before the farm assessment, smoothness of concrete surface and available space per cow in the holding yard, and length of feed-pad available per cow. Inappropriate handling of cows on the track (e.g., causing sideways pushing among cows) was also a contributing risk factor to high prevalence of lameness in these dairy herds. The findings of this study suggest that by managing several environmental and farming practices, producers can reduce the prevalence of lameness, leading to improved productivity of their herds.

Understanding barriers to reducing antimicrobials on Australian dairy farms: A qualitative analysis.

INTRODUCTION: Reducing antibiotic use in production animal systems is one strategy which may help to limit the development of antimicrobial resistance. To reduce antimicrobial use in food-producing animals, it is important to first understand how antibiotics are used on farm and what barriers exist to decreasing their use. In dairy production systems, mastitis is one of the most common reasons for administering antimicrobials. Therefore, it is important to understand the motivations and behaviours of dairy farmers in relation to the diagnosis, treatment and prevention of mastitis. MATERIALS AND METHODS: In this study, we interviewed a sample of dairy farmers and dairy industry professionals from the major dairying regions of eastern Australia regarding their current practices used to diagnose, treat, and control subclinical and clinical mastitis. Inductive thematic analysis was used to code interview transcripts and identify the recurrent themes. RESULTS: Four overarching themes were identified: (1) the challenges associated with the detection and diagnosis of clinical mastitis, including with laboratory culture, (2) the motivations behind treatment decisions for different cases, (3) decisions around dry cow therapy and the role of herd recording, and (4) concerns regarding the development of antimicrobial resistance. DISCUSSION: This study identifies several challenges which may limit the ability of Australian dairy farmers to reduce antimicrobial use on farm, such as the need for rapid and reliable diagnostic tests capable of identifying the pathogenic causes of mastitis and the difficulties associated with conducting herd recording for the implementation of selective dry cow therapy. Industry professionals were concerned that farmers were not using individual cow records to aid in treatment decisions, which could result in unnecessary antimicrobial use. The results of this study can act as the basis for future research aimed at assessing these issues across the broader Australian dairy industry.

Alteration in Gut Microbiota Composition of Older Adults Is Associated with Obesity and Its Indices: A Systematic Review.

BACKGROUND: Obesity in the older adults is a health concern that increases the risk of several life-threatening diseases. Previous research has been revealed that alterations in the gut microbiota composition is related to obesity. So, understanding the gut microbiota changes in older adults' obesity may help to provide promising strategies for their health management. OBJECTIVES: Here we conducted a systematic review that investigate the alteration of gut microbiota composition in association with obesity and its indices in the older adults. DESIGN: Systematic review. SETTING: A comprehensive systematic search was performed through PubMed, Web of Science, Scopus and Embase databases for all relative studies up to 2023 with the main search concepts as Microbiota, Obesity and Elderly. The data about gut microbiota in association with obesity indices had been extracted. PARTICIPANTS: Older adults (≥60 years). INTERVENTION: None. MEASUREMENTS: None. RESULTS: Within 10741 recordes, 11 studies met the inclusion criteria and were included in this systematic review. Most of them indicated the gut microbiota alterations in obese compared with non-obese older adults. However, the gut microbiome composition in obese older adults is affected by other underlying diseases like diabetes and metabolic syndrome. The most important taxa that had abundance alteration in association with obesity in older adults were Christensenellaceae, Porphyromonadaceae and Rikenellaceae, Akkermansia, Blautia, Prevotella, Ruminococcus, Bacteroides and Faecalibacterium. CONCLUSION: The gut microbiota composition is associated with obesity in older adults. Considering the other factors affecting the composition of gut microbiota, such as age, underlying diseases and lifestyle, a more accurate conclusion about this matter requires more future studies.

Effect of plasma-induced oxidative stress on the glycolysis pathway of Escherichia coli.

Antibiotic resistance is one of the world's most urgent public health problems. Due to its antibacterial properties, cold atmospheric plasma (CAP) may serve as an alternative method to antibiotics. It is claimed that oxidative stress caused by CAP is the main reason of bacteria inactivation. In this work, we computationally investigated the effect of plasma-induced oxidation on various glycolysis metabolites, by monitoring the production of the biomass. We observed that in addition to the significant reduction in biomass production, the rate of some reactions has increased. These reactions produce anti-oxidant products, showing the bacterial defense mechanism to escape the oxidative damage. Nevertheless, the simulations show that the plasma-induced oxidation effect is much stronger than the defense mechanism, causing killing of the bacteria.

Farmers' perceptions and approaches to detection, treatment and prevention of lameness in pasture-based dairy herds in New South Wales, Australia.

AIMS: The objective of this study was to investigate farmers' perception of lameness in comparison to the estimated prevalence of lameness in NSW pasture-based dairies to evaluate farmers' perceptions and approaches to detection, treatment and prevention of lameness. METHODS: Across-sectional study was conducted on 62 pasture-based dairy farms across NSW, Australia. The prevalence of lameness in these farms was estimated using locomotion scoring (1-4 scale). A survey was also conducted, using a questionnaire and face-to-face interview, to explore farmers' perceived prevalence of lameness and approaches to treatment and prevention. RESULTS: The prevalence of lameness estimated by farmers was 3.7 times less (mean: 5%; range 0% to 26%) than that determined by locomotion scoring (mean: 19.1%; range 5.0%-44.5%). Approaches to treatment included antimicrobial therapy, hoof inspection with or without application of wooden blocks. In 28% of the farms, the lame cows were managed by farmers or farm staff with no official training in treatment of lame cows. The mean interval from detection of lameness to examination of the affected hoof was almost 55 hours (range 2-720 hours). A very low percentage of farms kept lameness records or implemented lameness preventive strategies such as footbaths and prophylactic foot trimming. CONCLUSIONS: Farmers and farm managers were found to underestimate the prevalence of lameness which could be due to the low level of awareness and can contribute to subsequent lack of implementation of prophylactic procedures and preventive management strategies for lameness. These findings accentuate the need to improve farmers' ability to detect lame cows and to emphasise the importance of recording in order to facilitate the management of lameness in dairy herds.

Linear body measurements and productivity of subtropical Holstein-Friesian dairy calves.

OBJECTIVE: The study aimed to describe growth parameters and to quantify the association between linear body measurements as predictors of liveweight (LW) of Holstein-Friesian (HF), and HF crossbred dairy calves in Queensland. A secondary objective was to quantify the effect of disease events on LW change. STUDY DESIGN: Longitudinal study. METHODS: Fortnightly LW, hip height (HH), hip width (HW) and heart girth (HG) measurements were recorded from 16 male and 28 female HF calves from birth until weaning. The association between linear body measurement and the effect of a disease event on LW change were explored using linear mixed-effects modelling with random intercepts and random slopes. RESULTS: HG was the best body measure used individually as a predictor of calf LW (R2 = 82%; P < 0.001), while the combined use of HG, HW and HH was the most accurate predictor of calf LW between birth and weaning (R2 = 90%; P < 0.001). HW, average feed intake and total feed intake were significantly affected by disease events (P < 0.05). On average, total average LW loss associated with a single pneumonia event was estimated at 14.6 kg (95% CI = 10.5 to 18.7 kg; P < 0.05). CONCLUSIONS: Calves of this study performed at a level consistent with the previously published reports. Growth performance was significantly compromised by pneumonia. HW was found to be the least predictive individual measure, and the combined use of HH, HW and HG had the most accurate prediction of calf liveweight from birth to weaning.

Tetrahydroquinolinone derivatives as potent P-glycoprotein inhibitors: design, synthesis, biological evaluation and molecular docking analysis.

P-glycoprotein (P-gp) is a transmembrane efflux pump that has been associated with ineffective cancer chemotherapy and multidrug resistance (MDR). Chemical inhibitors of P-gp could have potential cancer therapeutic applications by preventing or reversing MDR. To exploit this, we designed twenty-five tetrahydroquinolinone analogs bearing pyridyl methyl carboxylate at C3 and different substituents at C4 as MDR reversal agents. The inhibitory effects of the synthesized compounds against P-gp were assessed by flow cytometric determination of rhodamine 123 accumulation in P-gp over-expressing MES-SA/DX5 cells. Fluorescence imaging of intracellular rhodamine 123 accumulation in MES-SA/DX5 cells was also performed. Furthermore, the effect of active derivatives on the reduction of doxorubicin's IC50 in MES-SA/DX5 cells was evaluated using MTT assay. Molecular docking was used to confirm the binding mode of some of the synthesized compounds. Five compounds in group A, bearing a 2-pyridyl methyl ester substituent at the C3 position, significantly increased rhodamine accumulation at 25 µM comparable to verapamil, a well-established P-gp inhibitor, while only 2 compounds in group B bearing 3-pyridyl methyl ester at the same position had this effect. This study shows that tetrahydroquinolinones containing methyl pyridine esters could represent an attractive scaffold for the discovery of P-gp inhibitors as MDR reversal agents in cancer cells.

MRI-Based Texture Analysis to Differentiate Sinonasal Squamous Cell Carcinoma from Inverted Papilloma.

BACKGROUND AND PURPOSE: Because sinonasal inverted papilloma can harbor squamous cell carcinoma, differentiating these tumors is relevant. The objectives of this study were to determine whether MR imaging-based texture analysis can accurately classify cases of noncoexistent squamous cell carcinoma and inverted papilloma and to compare this classification performance with neuroradiologists' review. MATERIALS AND METHODS: Adult patients who had inverted papilloma or squamous cell carcinoma resected were eligible (coexistent inverted papilloma and squamous cell carcinoma were excluded). Inclusion required tumor size of >1.5 cm and preoperative MR imaging with axial T1, axial T2, and axial T1 postcontrast sequences. Five well-established texture analysis algorithms were applied to an ROI from the largest tumor cross-section. For a training dataset, machine-learning algorithms were used to identify the most accurate model, and performance was also evaluated in a validation dataset. On the basis of 3 separate blinded reviews of the ROI, isolated tumor, and entire images, 2 neuroradiologists predicted tumor type in consensus. RESULTS: The inverted papilloma (n = 24) and squamous cell carcinoma (n = 22) cohorts were matched for age and sex, while squamous cell carcinoma tumor volume was larger (P = .001). The best classification model achieved similar accuracies for training (17 squamous cell carcinomas, 16 inverted papillomas) and validation (7 squamous cell carcinomas, 6 inverted papillomas) datasets of 90.9% and 84.6%, respectively (P = .537). For the combined training and validation cohorts, the machine-learning accuracy (89.1%) was better than that of the neuroradiologists' ROI review (56.5%, P = .0004) but not significantly different from the neuroradiologists' review of the tumors (73.9%, P = .060) or entire images (87.0%, P = .748). CONCLUSIONS: MR imaging-based texture analysis has the potential to differentiate squamous cell carcinoma from inverted papilloma and may, in the future, provide incremental information to the neuroradiologist.

Construction of infectious SIV/HIV-2 chimeras.

OBJECTIVE: To construct SIV/HIV-2 chimeras (SHIV) that replicate in vivo. These would be valuable tools to elucidate the mechanism by which HIV-2 can bypass protection conferred by live attenuated SIV vaccines. METHOD: Novel SHIV were constructed to express either the vpx, vpr, tat, rev and env genes (SHIV-2isy env) or the gag and pol genes (SHIV-2isy gag/pol) of the infectious molecular clone HIV-2isy in an SIVmac backbone. The replication of SHIV-2isy env and SHIV-2isy gag/pol were evaluated on selected cell lines and peripheral blood mononuclear cells (PBMC) in vitro. In addition, their infectivity was assessed in vivo. RESULT: Virus stocks of SHIV-2isy env and SHIV-2isy gag/pol were prepared in vitro. For SHIV-2isy gag/pol both the 5' and 3' boundaries of the chimeric construct were critical for infectivity in vitro. The growth of each chimera on T cell lines in vitro mirrors that of the parental viruses donating the envelope gene. On PBMCs SHIV-2isy env replicated well on human and simian PBMC whereas SHIV-2isy gag/pol replicated to detectable levels on human PBMC only. In vivo, SHIV-2isy env virus was isolated from one of two cynomolgus macaques challenged intravenously, SHIV-2isy gag/pol was isolated from one of two cynomolgus macaques and both rhesus macaques challenged intravenously. CONCLUSION: This is the first report of SIV/HIV-2 chimeras that are infectious in macaques. Moreover, this is the first report of an infectious chimera in which both SIV gag and pol have been replaced with the equivalent regions of an HIV isolate.

Influence of hydrogen peroxide on the in vitro infectivity of human immunodeficiency virus.

The object of this study was to investigate the influence of reactive oxygen intermediates (ROI), such as H2O2, on HIV-1 infection of cell cultures. The CD4+ HeLa human epithelial carcinoma cell line clone pBKTRLac was infected with HIV-1MN that had been treated with 0.01-5mM H2O2. Virus infectivity was detected by 3 methods: (a) using transactivation of LTR-linked beta-Galactosidase, (b) viral core p24 antigen enzyme-linked immunoasorbent assay (ELISA), and (c) reverse transcriptase activity assay. Treatment of HIV-1MN cell free virus particles with 0.01 mM H2O2 resulted in a significant increase in virus infection. This effect declined with increasing H2O2 concentrations from 0.05 to 0.1 mM. Further increases in H2O2 concentration up to 5 mM resulted in significant suppression in virus infection. These observations indicate that H2O2 may play a role in affecting the course of HIV infection.

The construction and evaluation of SIV/HIV chimeras that express the envelope of European HIV type 1 isolates.

The molecular construction of SIV/HIV-1 chimeric viruses (or SHIVs), provides a means of infecting macaques with immunodeficiency viruses that express the envelope protein of HIV-1. However, to date, most SHIVs produced express the envelope of isolates of HIV-1 that have been passaged repeatedly in T cell lines. We have taken SHIV-4 and replaced an NheI-AvrII fragment that encompasses the gp120 region and the extracellular portion of gp41 with the equivalent region of two European isolates of HIV-1 (ACH320.3.1 and HIV-1Han-2). Neither of these viruses had been passaged in T cell lines for prolonged periods prior to molecular cloning. Virus stocks were prepared of both SHIV constructs. In vitro, the relative ability of each clone to replicate in four T cell lines mirrored closely the pattern observed with the parental virus donating the envelope sequences. In vivo, only one of the chimeric viruses was infectious in cynomolgus macaques and its recovery was transient. The factors that affect the replication of SHIVs in vitro and in vivo are discussed.

Molecular characterization of an HIV type 1 isolate from Burundi.

PIP: HIV infection is highly prevalent in Burundi. There are, however, few published reports on the envelope sequence of the prevailing HIV-1 strains in the country. The authors selected an isolate of HIV-1 from Burundi and characterize the envelope glycoprotein gp120 in detail. A sample of venous blood was taken from a 36-year-old HIV-1-positive female volunteer from Bujumbura classified as WHO stage IV, exhibiting clinical AIDS and pulmonary tuberculosis. Nine clones containing complete gp120 genes were derived from the isolate and were designated 91BU009D/1-9. The sequences have been submitted to the Los Alamos Database under accession numbers L35452-L35459 (two clones had a stop codon in their C1 regions and were not studied further). The viral sequences from the coculture closely reflect that circulating in the patient's peripheral blood mononuclear cells. That finding is in striking contrast to the rapid adaptation and evolution of HIV-1 passaged onto human T cell lines. The ability to isolate and culture virus in vitro without the rapid appearance and selection of mutants is important, because it enables relevant observations to be made with regard to the antigenic recognition of the virus by the host. The authors' study found that although 91BU009D clustered with the D subtype, it contained unique sequences noticeably divergent from other characterized proviruses of the D subtype. Further work to investigate and clarify the relationship between genotype and serotype of HIV-1 isolates is of the utmost importance if molecular epidemiology is to be of value in designing an effective AIDS vaccine.^ieng

Standard conditions of virus isolation reveal biological variability of HIV type 1 in different regions of the world. WHO Network for HIV Isolation and Characterization.

HIV-1 isolates were obtained from four countries within the framework of the WHO Network for HIV Isolation and Characterization. The use of standard HIV isolation procedures allowed us to compare the biological properties of 126 HIV-1 isolates spanning five genetic subtypes. In primary isolation cultures, viruses from Uganda and Brazil appeared early and replicated without delay, whereas the replication of Thai viruses was delayed by several weeks. Regardless of genetic subtype or country of origin, blood samples collected more than 2 years after seroconversion yielded virus that replicated efficiently in the primary isolation cultures. None of the isolates obtained from Thailand or Rwanda replicated in cell lines, whereas 5 of the 13 Brazilian isolates and 7 of the 11 Ugandan isolates replicated and induced syncytia in MT-2 cells. As expected for virus isolates obtained early in HIV-1 infection (within 2 years of seroconversion), all viruses from Brazil, Rwanda, and Thailand showed a slow/low replicative pattern. For the Ugandan samples, the time from seroconversion was known precisely for a few of the samples and only in one case was less than 2 years. This may explain why the five viruses that were able to replicate in all cell lines, and thus classified as rapid/high, were of Ugandan origin. Viruses able to induce syncytia in MT-2 cells, also induced syncytia in PBMC. However, 8 slow/low viruses (out of 27) gave discordant results, inducing syncytia in PBMC but not in MT-2 cells. Furthermore, using syncytium induction as a marker, changes in virus populations during early in vitro passage in PBMC could be observed.(ABSTRACT TRUNCATED AT 250 WORDS)

DNA damage in human T-lymphoblastoid cell line Molt-3 induced by reactive oxygen species.

In the course of studying the effect of reactive oxygen species such as superoxide anion (O2-), hydrogen peroxide (H2O2) on oxidant-sensitive human T-lymphoblastoid cell line Molt-3, O2- has been generated by the interaction of xanthine with xanthine oxidase (XOD). To confirm that H2O2 is a key intermediate for inducing DNA single-strand breaks in Molt-3 cells, studies have been carried out with pure H2O2. In the presence of xanthine + XOD or H2O2 the amount of DNA single-strand breaks has been found to increase as a function of the O2- and H2O2 concentration. Data from studies with antioxidants such as superoxide dismutase and catalase supports a mechanism of DNA damage dependent on the presence of H2O2 in Molt-3 cells. Molt-3 cells are CD4+ and sensitive to reactive oxygen stress and therefore, could be an ideal cell line for determining the relationship between oxidative stress and various diseases such as acquired immunodeficiency syndrome (AIDS).

Ultrastructural localization of the RNA of immunodeficiency viruses using electron microscopy in situ hybridization and in vitroinfected lymphocytes.

Cells infected in vitro with immunodeficiency viruses have been examined by electron microscopy in situ hybridization (EM ISH) methods for localization of viral RNA. Techniques used for preparation of specimens and probes are described. Unambiguous positive results were obtained using a mixture of two or three single negative strand DNA oligonucleotides complementary to regions of the gag, env and nef genes, each 200-300 bases and labelled with dig-11-UTP. Positive strand probes were used as a negative control. Cells were fixed with a mixture of formaldehyde and glutaraldehyde, dehydrated in ethanol with progressive lowering of temperature and embedded in Lowicryl K4M or HM20 at -35 degrees C. Permeabilization or pre-treatment of sections with proteinase K was not essential. The hybridization mixture was applied for 3-4h at 37 degrees C and probe was visualized by direct immuno-staining with sheep anti-digoxigenin antibodies conjugated to 10nm gold. This method would be suitable for future studies of the pathogenesis of retroviral infections and as a basis for further development of the EM ISH technique. EM ISH of in vitro infections of immunodeficiency viruses has shown the location of viral RNA in immature and mature viruses and its relationship to multimerized Gag protein during viral budding. The label for RNA has also been found in the cytoplasm of infected cells; it was mainly located adjacent to the plasma membrane and unassociated with visible Gag proteins. This may indicate that viral RNA migrates to the plasma membrane independently of the Gag protein and may, in some instances, arrive at the plasma membrane prior to the Gag protein. Viral RNA has also been found in the nucleus of peripheral blood mononuclear cells (PBMC) that were showing no morphological evidence of infection. The RNA was typically located in the nucleolus and in peripheral dense chromatin. These cells, which displayed morphological features of macrophage lineage, may have been the initial cell type to be infected in the PBMC.

Allergy to human insulin and specific immunotherapy with glargine; case report with review of literature.

Insulin has an important role in the treatment of diabetic patients. Further, it can result in undesirable side effects. One of the problems that are associated with insulin therapy is allergic reactions. Although insulin allergy is uncommon, especially in patients with type-2 diabetes, but when it occurs, its management can be difficult. We report a 55-year-old woman with poorly controlled type-2 diabetes and insulin allergy. She revealed hypersensitivity reactions including urticaria and respiratory symptoms, immediately after injection. So, specific immunotherapy with other insulin preparations was done. Finally, after specific immunotherapy, we were able to treat the patient with short- and long-acting analogs successfully.