Influence of sampling technique and bedding type on the milk microbiota: Results of a pilot study.

The objective of this pilot study was to evaluate the influence of sampling technique and exposure to different bedding types on the milk microbiome of healthy primiparous cows. Primiparous Holstein cows (n = 20) with no history of clinical mastitis or monthly somatic cell counts >150,000 cells/mL were selected for this study. From each enrolled cow, a composite milk sample was aseptically collected from all 4 mammary quarters (individual quarter somatic cell counts <100,000 cells/mL), 1 individual quarter milk sample was collected using conventional aseptic technique, and 2 individual quarter milk samples were collected directly from the gland cistern using a needle and vacuum tube. All milk samples were cultured using standard milk microbiological techniques and DNA was extracted. Extracted DNA was subjected to PCR and next-generation sequencing for microbiota determination. All samples yielded relatively little total DNA. Amplification of PCR was successful in 45, 40, and 83% of composite, conventional, and cisternal samples, respectively. Bacteria were successfully cultured from 35% of composite milk samples but from none of the quarter milk samples collected using conventional or cisternal sampling techniques. Bacterial DNA sequences were assigned to operational taxonomic units (OTU) based on 97% sequence similarity, and bacterial richness and diversity were determined. Most samples were dominated by low-prevalence OTU and of the 4,051 identified OTU, only 14 were prevalent at more than 1% each. These included bacteria typically recovered from environmental sources. Chao richness was greatest in composite samples and was 636, 347, and 356 for composite, conventional quarter, and cisternal milk samples, respectively. Shannon diversity was similar among sample types and ranged from 3.88 (quarter) to 4.17 (composite). Richness and diversity did not differ by bedding type among cisternal samples, but the power of this pilot study was limited due to small sample size. Despite the small sample size, for milk samples collected from the gland cistern, overall bacterial community composition differed among bedding types. These results demonstrate that sampling technique and bedding type may be associated with the microbiota detected in bovine milk, and we suggest that these variables should be considered in designing and reporting studies about the milk microbiota.

Whole genome sequencing for M/XDR tuberculosis surveillance and for resistance testing.

Whole genome sequencing (WGS) can help to relate Mycobacterium tuberculosis genomes to one another to assess genetic relatedness and infer the likelihood of transmission between cases. The same sequence data are now increasingly being used to predict drug resistance and susceptibility. Controlling the spread of tuberculosis and providing patients with the correct treatment are central to the World Health Organization's target to 'End TB' by 2035, for which the global prevalence of drug-resistant tuberculosis remains one of the main obstacles to success. So far, WGS has been applied largely to drug-susceptible strains for the purposes of understanding transmission, leaving a number of analytical considerations before transferring what has been learnt from drug-susceptible disease to drug-resistant tuberculosis. We discuss these potential problems here, alongside some of the challenges to characterizing the Mycobacterium tuberculosis 'resistome'-the optimal knowledge-base required for WGS-based assays to successfully direct individualized treatment regimens through the prediction of drug resistance and susceptibility in the future.

Contact investigations for outbreaks of Mycobacterium tuberculosis: advances through whole genome sequencing.

The control of tuberculosis depends on the identification and treatment of infectious patients and their contacts, who are currently identified through a combined approach of genotyping and epidemiological investigation. However, epidemiological data are often challenging to obtain, and genotyping data are difficult to interpret without them. Whole genome sequencing (WGS) technology is increasingly affordable, and offers the prospect of identifying plausible transmission events between patients without prior recourse to epidemiological data. We discuss the current approaches to tuberculosis control, and how WGS might advance public health efforts in the future.

Monitoring expression of HER-2 on circulating epithelial cells in patients with advanced breast cancer.

Nineteen breast cancer patients with measurable metastatic disease who were starting an initial or new line of therapy were evaluated for circulating epithelial cells (CECs) a minimum of 4 times over the course of treatment. In 7 of the 10 CEC+ patients, HER-2 expression was detected on the CECs. CECs expressing HER-2 varied among patients and in serial samples from the same patient including a shift from HER-2- to HER-2+ CECs. These results demonstrate that it is possible to quantify receptors essential for rationally designed therapy using CECs and that reliance on the immunophenotype of the primary tumor can be misleading.

Cytochrome P450 activity in control and induced long-term cultures of rat hepatocyte spheroids.

Long-term events such as enzyme induction or chronic toxicity require long-term liver culture models that maintain activity of xenobiotic metabolising enzymes. The levels of these enzyme activities and their responsiveness to chemical induction was studied in rat hepatocyte spheroids, a potential long-term hepatocyte culture model. In comparison with other long-term liver culture models, the basal metabolic activity of spheroids has not been well studied. Additionally, no existing data on the induction of CYP3A activity in spheroids could be found. The basal xenobiotic metabolising activity of rat hepatocyte spheroids was monitored over 14 days in culture, using testosterone as a probe substrate. When spheroids from days 2-14 in culture were compared to 24-h control spheroids, there was a differential maintenance of basal CYP activity. CYP2A and CYP3A activities were maintained over the culture period, while there were time-related decreases in CYP2C11 and CYP2C/CYP2B1/2 activities. The responsiveness of rat hepatocyte spheroids to chemical induction was studied following treatment with phenobarbitone (PB) or dexamethasone (DEX). PB treatment induced CYP2A, CYP2C, CYP2B1/2 and CYP3A activities. DEX treatment resulted in an induction of CYP3A and CYP2C11 activities. The results demonstrate that rat hepatocyte spheroids retained some of the liver-specific functions essential in a long-term hepatocyte culture model, thus making spheroids comparable to other long-term culture models available.

The differential cytotoxicity of methotrexate in rat hepatocyte monolayer and spheroid cultures.

It is important to assess the usefulness of long-term in vitro liver models for studying chronic toxicity, since acute assays may not reflect the in vivo situation. A potential long-term hepatocyte culture (i.e. liver spheroids) was investigated and compared to primary rat hepatocyte monolayer cultures following exposure to methotrexate (MTX), a well-documented chronic hepatotoxin. Following up to 7 days' treatment with MTX, cultures were morphologically assessed and assayed for enzyme leakage, intracellular reduced glutathione (GSH) and adenosine triphosphate (ATP). Spheroids maintained higher concentrations of GSH over the 14-day culture and ATP was maintained, but at a concentration not significantly different from monolayer cultures. Treatment of monolayer cultures resulted in concentration-related decreases in GSH and ATP, accompanied by enzyme leakage. In contrast, only ATP was affected following treatment of spheroids for 7 days. Spheroids appeared to be less sensitive to exposure to MTX, when compared with monolayer cultures. This may result from the maintenance of cellular functions, or from the lack of compound penetration into the three-dimensional spheroid structure. Therefore, the usefulness of spheroids to chronic in vitro toxicity testing may be limited.

Gallstones in sickle cell disease: observations from The Jamaican Cohort study.

The prevalence, incidence, risk factors, clinical associations, and morbidity of gallstones were studied in 311 patients with homozygous sickle cell disease and 167 patients with sickle cell-hemoglobin C disease in a cohort study from birth. Gallstones developed in 96 patients with homozygous sickle cell disease and 18 patients with sickle cell-hemoglobin C disease; specific symptoms necessitating cholecystectomy occurred in only 7 patients with homozygous sickle cell disease.

The neurotoxic effects of methylenedioxymethamphetamine (MDMA) and its metabolites on rat brain spheroids in culture.

Rat whole-brain spheroids were used to assess the intrinsic neurotoxicity of methylenedioxy-methamphetamine (MDMA, Ecstasy) and two of its metabolites, dihydroxymethamphetamine (DHMA) and 6-hydroxy-MDMA (6-OH MDMA). Exposure of brain spheroids to MDMA or the metabolite 6-OH MDMA (up to 500 micromol/L) for 5 days in culture did not alter intracellular levels of glutathione (GSH), glial fibrillary acidic protein (GFAP) or serotonin (5-HT). In contrast, exposure to the metabolite DHMA, which can deplete intracellular thiols, significantly increased GSH levels (up to 170% of control) following exposure to 50 and 100 micromol/L DHMA. There was also a significant reduction in the levels of glial fibrillary acidic protein (GFAP) and GSH by DHMA at the highest concentration tested (500 micromol/L) but there was no effect on 5HT. This may constitute a sublethal neurotoxic compensatory response to DHMA in an attempt to replenish depleted intraneural GSH levels following metabolite exposure. Rat whole-brain spheroids may thus be a useful in vitro model to delineate mechanisms and effects of this class of neurotoxin.

A redefined type of elbow dysplasia in the dog--2 cases.

Two dogs with calcified masses on the medial aspect of the elbow, resembling those previously reported as ununited medial humeral epicondyle, support proposed ideas that these masses arise due to calcification of flexer tendons at their origin, and that different pathogeneses are likely involved in their development.

The identification and differential expression of calcium-binding proteins associated with ocular melanoma.

Calcium-binding proteins may endow tumor cells with properties related to their malignancy and metastatic phenotype. Chromatographic procedures and amino acid sequence analysis were used in this study to identify seven calcium-binding proteins, annexin VI, cap g, annexin V, calmodulin, S100A11, S100B and S100A6, associated with uveal melanoma, the primary ocular tumor of adults. This series of calcium-binding proteins was identified in both primary tumors and cell lines of uveal melanoma. Several of the proteins were shown by immunochemical methods to be differentially expressed between normal uveal melanocytes and malignant melanomas of the uvea. In addition, the expression of S100A6 may correlate with the malignant properties of the tumor.

Taxol-mediated changes in fibrosarcoma-induced immune cell function: modulation of antitumor activities.

The anticancer drug taxol (paclitaxel) inhibits tumors through multiple cytotoxic and cytostatic mechanisms. Independently of these mechanisms, taxol induces distinct immunological efficacy when it acts as a second signal for activation of tumoricidal activity by interferon gamma (IFN gamma)-primed murine normal host macrophages. We reported that tumor-distal macrophages, which mediate immunosuppression through dysregulated nitric oxide (NO) and tumor necrosis factor alpha (TNF alpha) production, are differentially regulated by taxol. Because taxol influences tumor cell growth dynamics and activates immune cell populations, we assessed the ex vivo immunosuppressive and antitumor activities of taxol-treated normal host and tumor-bearing host (TBH) macrophages. Pretreatment of such cells with taxol partly reconstituted T cell alloantigen reactivity, suggesting that taxol mediates a limited reversal of TBH macrophage immunosuppressive activity. Taxol-treated TBH macrophages significantly suppressed the growth of fibrosarcoma cells (Meth-KDE) through soluble effector molecules and promoted direct cell-mediated cytotoxicity, indicating that taxol enhanced tumor-induced macrophage antitumor activities. Tumor-induced helper T cells, however, showed a higher sensitivity to direct taxol-induced suppression. These data demonstrate that taxol exerts pleiotropic effects on antitumor immune responses with the capacity to abate the immunosuppressive activities of macrophages and promote macrophage-mediated antitumor activities simultaneously, but also directly modulating T cell reactivity. Collectively, these studies suggest that the antineoplastic drug taxol may impart antitumor activity through an immunotherapeutic capacity.

Uncomplicated pregnancy following total bilateral rectus harvest: a case report.

Muscle-sparing rectus abdominis muscle harvest has been advocated to preserve abdominal wall integrity and to reduce postoperative complications and functional loss. In previous cases of pregnancy following single and bilateral rectus muscle harvest, muscle-sparing techniques were used to fortify the abdominal wall. We report a case of uncomplicated gestation and delivery following total bilateral rectus muscle harvest. While abdominal wall strength is greatly affected by rectus harvest, the fascial and tendonous components of the abdominal wall contribute substantial static integrity and elasticity. Careful repair of the donor site makes complete rectus muscle harvest an option even for women contemplating pregnancy.

Renal length in sickle cell disease: observations from a cohort study.

Renal length has been measured by ultrasound in 237 subjects with homozygous sickle cell (SS) disease, 147 with sickle cell-hemoglobin C (SC) disease, and in 78 age-matched controls with a normal hemoglobin (AA) genotype. As expected, renal length increased with age in all genotypes but mean length was significantly greater in SS disease compared with SC disease (mean difference 4.3 mm after adjustment for height) and significantly greater in both genotypes than in AA controls (SS/AA difference 9.2 mm, SC/AA difference 5.0 mm after adjustment for height). Examination of relationships between renal length and some hematological indices (hemoglobin, fetal hemoglobin, reticulocyte counts, alpha thalassemia status) in SS or SC disease showed only a significant negative correlation with hemoglobin and positive correlation with reticulocyte count in SS disease. Further analysis suggested that the stronger relationship was between renal length and high reticulocyte count. The mechanism of renal enlargement is unknown although glomerular hypertrophy and increased renal blood volume are likely contributors.

Biliary sludge in sickle cell disease.

Biliary sludge was observed in the gallbladder in 17 of 429 patients in a cohort study of sickle cell disease. Discrete gallstones later developed in 12 patients, but no stones developed in five patients; one patient with biliary sludge had no change in his condition for 5 years. None of the patients with biliary sludge had any symptoms referable to the biliary tract, and cholecystectomy has not been performed. The Jamaican experience suggests that biliary sludge may be treated conservatively, similar to our approach to asymptomatic gallstones.

Increased renal reflectivity in sickle cell disease: prevalence and characteristics.

Renal ultrasound appearances have been examined in 315 patients with sickle cell disease aged 10-20 years, followed in a cohort study from birth. There were three different echo patterns. A normal appearance (type 1) occurred in 235 (75%) of all subjects, and in 159/179 (89%) with homozygous sickle cell (SS) disease. A diffuse increase in reflectivity throughout the kidney (type 2), similar to that of adjacent liver, occurred in 17 patients (5%). Widespread confluent or focal increase in reflectivity confined to the renal medulla (type 3) occurred in 63 (20%) of the total group, and was much more common in the mild genotypes of sickle cell-haemoglobin C disease (41/111, 37%) and sickle cell-beta+ thalassaemia (15/19, 79%) than in SS disease (5/179, 3%). We speculate that type 2 changes may reflect diffuse glomerular and interstitial fibrosis, and that type 3 resembles changes seen in sub-clinical nephrocalcinosis, and could be due to iron deposition.