Diet creates metabolic niches in the "immature gut" that shape microbial communities

Although diet composition has been implicated as a major factor in the etiology of various gastrointestinal diseases, conclusive evidence remains elusive. This is particularly true in diseases such as necrotizing enterocolitis where breast milk as opposed to commercial formula appears to confer a "protective effect" to the "immature gut." Yet the mechanism by which this occurs continues to remain speculative. In the present study we hypothesize that the basic chemical composition of diet fundamentally selects for specific intestinal microbiota which may help explain disparate disease outcome and therapeutic direction. Complimentary animal and human studies were conducted on young piglets (21 d.)(n = 8) (IACUC protocols 08070 and 08015) and premature infants (adjusted gestational age 34-36 weeks) (n = 11) (IRB Protocol 15895A). In each study, cecal or stool contents from two groups (Breast milk-fed (BF) vs. Formula-fed (FF)) were analyzed by gas chromatography/mass spectrometry (GC/MS) and comprehensive metabolic profiles generated and compared. Concurrently, bacterial community structure was assayed and respective representative microbiota of the groups determined by 16S rRNA gene amplicon pyrosequencing. Statistical modeling and analysis was done using SIMCA-P+ and R software. GC/MS metabolomics identified clear differences between BF and FF groups in the intestinal environment of piglets and humans. Sugars, amino-sugars, fatty acids, especially unsaturated fatty acids, and sterols were identified as being among the most important metabolites for distinguishing between BF and FF groups. Joint analysis of microbiota and metabolomics pinpointed specific sets of metabolites (p < 0.05) associated with the dominant bacterial taxa. The chemical composition of diet appears to have a significant role in defining the microbiota of the immature gut. Tandem analysis of intestinal microbial and metabolic profiles is potentially a powerful tool leading to better understanding of the role of diet in disease perhaps even leading to specific strategies to alter microbial behavior to improve clinical outcome.

A mutation in the rice chalcone isomerase gene causes the golden hull and internode 1 phenotype

The biosynthesis of flavonoids, important secondary plant metabolites, has been investigated extensively, but few mutants of genes in this pathway have been identified in rice (Oryza sativa). The rice gold hull and internode (gh) mutants exhibit a reddish-brown pigmentation in the hull and internode and their phenotype has long been used as a morphological marker trait for breeding and genetic study. Here, we characterized that the gh1 mutant was a mutant of the rice chalcone isomerase gene (OsCHI). The result showed that gh1 had a Dasheng retrotransposon inserted in the 5′ UTR of the OsCHI gene, which resulted in the complete loss of OsCHI expression. gh1 exhibited golden pigmentation in hulls and internodes once the panicles were exposed to light. The total flavonoid content in gh1 hulls was increased threefold compared to wild type. Consistent with the gh1 phenotype, OsCHI transcripts were expressed in most tissues of rice and most abundantly in internodes. It was also expressed at high levels in panicles before heading, distributed mainly in lemmas and paleae, but its expression decreased substantially after the panicles emerged from the sheath. OsCHI encodes a protein functionally and structurally conserved to chalcone isomerases in other species. Our findings demonstrated that the OsCHI gene was indispensable for flux of the flavonoid pathway in rice.

ZIP4 in homologous chromosome synapsis and crossover formation in rice meiosis

In budding yeast, the ZMM complex is closely associated with class I crossovers and synaptonemal complex (SC) formation. However, the relationship between the ZMM genes remains unclear in most higher eukaryotes. Here, we identify the rice ZIP4 homolog, a member of the ZMM gene group, and explore its relationship with two other characterized ZMM genes, MER3 and ZEP1. Our results show that in the rice zip4 mutant, the chiasma frequency is greatly reduced, although synapsis proceeds with only mild defects. Immunocytological analyses of wild-type rice reveal that ZIP4 presents as punctuate foci and colocalizes with MER3 in prophase I meiocytes. Additionally, ZIP4 is essential for the loading of MER3 onto chromosomes, but not vice versa. Double-mutant analyses show that zip4 mer3 displays a greater decrease in the mean number of chiasmata than either of the zip4 or mer3 single mutants, suggesting that ZIP4 and MER3 work cooperatively to promote CO formation but their individual contributions are not completely identical in rice. Although zep1 alone gives an increased chiasma number, both zip4 zep1 and mer3 zep1 show a much lower chiasma number than the zip4 or mer3 single mutants. These results imply that the normal functions of ZIP4 and MER3 are required for the regulation of COs by ZEP1.

Somatic and reproductive cell development in rice anther is regulated by a putative glutaredoxin

The switch from mitosis to meiosis is one of the most pivotal events in eukaryotes undergoing sexual reproduction. However, the mechanisms orchestrating meiosis initiation remain elusive, particularly in plants. Flowering plants are heterosporous, with male and female spore genesis adopting different developmental courses. We show here that plant pollen mother cells contain a specific meiosis initiation machinery through characterization of a rice (Oryza sativa) gene, MICROSPORELESS1 (MIL1). The mil1 mutant does not produce microspores in anthers but has the normal female fertility. Detailed molecular and cytological investigations demonstrate that mil1 anthers are defective in the meiotic entry of sporogenous cell progenies and in the differentiation of surrounding somatic cell layers, resulting in locules filled with somatic cells instead of microspores. Furthermore, analysis of mil1 msp1 double mutants reveals that due to the absence of MIL1, the cells in their anther locule center do not activate meiotic cell cycle either, generating a similar anther phenotype to mil1. MIL1 encodes a plant-specific CC-type glutaredoxin, which could interact with TGA transcription factors. These results suggest meiotic entry in microsporocytes is directed by an anther-specific mechanism, which requires MIL1 activity, and redox regulation might play important roles in this process.

Leaving a mark: the frequency and accuracy of tattooing prior to laparoscopic colorectal surgery

AIM

Intra-operative localization of small cancers and polyps during laparoscopic colorectal surgery is difficult due to reduced tactile feedback. The consequences of failing to identify the lesion for resection can result in open conversion or removal of the wrong segment of bowel.

METHOD

Data were collected from a prospectively-kept database over a 12-month period from April 2008 to March 2009 and analysed retrospectively. Details concerning the documentation, visibility and accuracy of tattoos were recorded.

RESULTS

Eighty-five patients (88 lesions) underwent laparoscopic resection for a benign or malignant colorectal tumour during 1 year from April 2008. Eighty-one patients underwent endoscopic visualization of the tumour as a first or second procedure. Of these 81 patients, 83 lesions were visualized endoscopically and 54 (65.1%) were tattooed in 52 patients. In the 52 patients, 36 (69%) of the tattoos were carried out on the first endoscopy. At operation the tattoo was judged to be visible and accurate in 70%, visible but inaccurate in 7% and not visible in 15%. It was significantly easier to see the tattoo in women (19/21 women vs 21/29 men; P=0.03) but there was no relationship between tattoo visibility and BMI. An accurate tattoo did not reduce the conversion rate (P=0.71). No tattoo-related complications were encountered.

CONCLUSION

The practice of tattooing colorectal cancers is variable in frequency, technique and accuracy. We advocate that all colonic lesions suspicious for cancer should be tattooed during endoscopy at a defined distance below the tumour, adhering to a departmental protocol in case surgery is required.

Toxicity of hypofractionated adjuvant radiation after breast-conserving surgery for DCIS

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Background: Traditional fractionation for whole breast radiation therapy after breast-conserving surgery has been 50Gy in 25 fractions over a 5-week period, with or without a 10 Gy boost. Hypofractionation has recently been adapted for early-stage invasive breast cancer, typically treating with 42.5 Gy in 16 daily fractions. This approach has been shown to have equivalent efficacy as the more traditional schedule. Its application to patients with DCIS has been an extrapolation of these data, and warrants further examination. This retrospective analysis reviews toxicity outcomes in women with DCIS treated with hypofractionation at our institution.

Methods: 59 women with DCIS treated with lumpectomy and hypofractionated radiotherapy with or without boost between 2006 and 2010 at the Einstein-Montefiore Cancer Center were identified. Median age was 65 (39-85). Median follow-up was 13.7 months (2–37.6). Surgical margin status was negative in 55, positive in 1, and unknown in 3. Thirteen patients had high-grade DCIS, 17 intermediate-grade, and 13 low-grade nuclear features, and 16 did not have grade delineation. 68% of patients (40 women) had disease that was positive both for ER and PR receptors, 2 women were simultaneously positive for ER and PR, 5 women had ER-only positive disease, 2 women had HER2-neu-only positive disease, 1 woman was positive for both ER and HER2-neu receptors, 1 woman was positive only for PR receptors, and 6 women were negative for all receptors; receptor status of specimens from 2 patients is not known. All women were treated with whole-breast hypofractionated therapy (42.4 Gy, in 16 fractions of 2.65 Gy each). 49 women received a boost to the lumpectomy cavity consisting of 10Gy in 5 fractions or 9.6 Gy in 4 fractions at the physician’s discretion.

Results: With this regimen, no patient experienced acute RTOG grade 3 or higher skin, or other toxicity. No treatment breaks were required due to toxicity. The most common side effects were grade 1 dermatitis, followed by grade 2 dermatitis with mild edema of the treated breast.

Conclusions: Our results suggest that postoperative hypofractionated radiation to the breast is well tolerated by women with DCIS and does not result in untoward acute toxicity.

Dynamic heterogeneities, boson peak, and activation volume in glass-forming liquids

There are various arguments and models connecting the characteristic length associated with the boson peak vibrations ξ to the length scale of dynamical heterogeneity L(het). ξ is usually defined as the ratio of the transverse sound velocity to the boson peak frequency. Here we present pressure, temperature, and molecular weight dependencies of ξ, estimated using light scattering, in a few molecular and polymeric glass formers. These dependencies are compared with respective dependencies of the activation volume ΔV(#) in the same materials. Good agreement is found for the pressure and molecular weight dependencies of ξ and ΔV(#) measured at the glass transition temperature T(g). These results provide more evidence for a possible relationship between the sensitivity of structural relaxation to density (activation volume) and the heterogeneity volume. However, contrary to the expectations for L(het), ξ does not decrease with temperature above T(g) in most of the studied materials. The temperature dependence of ξ is compared to that of L(het) in glycerol and orthoterphenyl (OTP) estimated from literature data. The analysis shows a clear difference in the behavior of ξ(T) and ΔV(#)(T) at temperatures above T(g), although ΔV(#)(T)(1/3) and L(het)(T) have similar temperature dependence. Possible reasons for the observed difference are discussed.

The role of serum basic fibroblast growth factor, estradiol and urine basic fibroblast growth factor in differentiating infantile haemangiomas from vascular malformations

OBJECTIVE

To investigate the role of serum basic fibroblast growth factor (bFGF), estradiol (E2) and urine bFGF in differentiating infantile haemangiomas from vascular malformations.

METHOD

Between October 2007 and January 2009, 97 patients with haemangiomas and 25 patients with vascular malformations who had not been treated previously were included in this prospective study. Forty-eight patients with cleft lip and/or palate were selected as controls. The age of all subjects ranged from 1 to 30 months. The serum and urine levels of bFGF were determined by enzyme-linked immunosorbent assay (ELISA). The serum levels of E2 were examined via radioimmunoassay. All data were analysed with SPSS 11.5 software package.

RESULTS

The concentration of serum and urine bFGF was significantly different among the three groups (haemangiomas, vascular malformations and controls) (P = 0.027, P = 0.001). Significantly different urine bFGF levels were found in patients with proliferating and involuting haemangiomas (P = 0.04). The serum E2 levels were significantly higher in patients with haemangiomas than vascular malformations (P = 0.001) and controls (P = 0.001).

CONCLUSION

Serum bFGF and E2 as well as urine bFGF can be used to supplement the clinical diagnosis of congenital vascular anomalies. Urine bFGF combined with serum E2 may be the most potential markers for diagnosing haemangiomas and determining the proliferating stage of haemangiomas.