Optic Nerve Size in Blind and Normal Mice

Measurements of eyes and optic nerves of blind and normal mice were taken at ages ranging from 1-60 days. The mice used were from a Bagg albino strain in which a dominant mutation for blindness had occurred. The size of the optic nerve appears to be dependent upon the development of the eye. Optic nerves from blind eyes are smaller than those from normal eyes, and optic nerves from blind eyes without a lens and with a folded retina are smaller than those from eyes with a lens, even though the lens is vacuolated and the cornea is thickened

Sampling Local Fungal Diversity in an Undergraduate Laboratory using DNA Barcoding

Traditional methods for fungal species identification require diagnostic morphological characters and are often limited by the availability of fresh fruiting bodies and local identification resources. DNA barcoding offers an additional method of species identification and is rapidly developing as a critical tool in fungal taxonomy. As an exercise in an undergraduate biology course, we identified 9 specimens collected from the Hendrix College campus in Conway, Arkansas, USA to the genus or species level using morphology. We report that DNA barcoding targeting the internal transcribed spacer (ITS) region supported several of our taxonomic determinations and we were able to contribute 5 ITS sequences to GenBank that were supported by vouchered collection information. We suggest that small-scale barcoding projects are possible and that they have value for documenting fungal diversity

Macrocyclic colibactin induces DNA double-strand breaks via copper-mediated oxidative cleavage.

Colibactin is an assumed human gut bacterial genotoxin, whose biosynthesis is linked to the clb genomic island that has a widespread distribution in pathogenic and commensal human enterobacteria. Colibactin-producing gut microbes promote colon tumour formation and enhance the progression of colorectal cancer via cellular senescence and death induced by DNA double-strand breaks (DSBs); however, the chemical basis that contributes to the pathogenesis at the molecular level has not been fully characterized. Here, we report the discovery of colibactin-645, a macrocyclic colibactin metabolite that recapitulates the previously assumed genotoxicity and cytotoxicity. Colibactin-645 shows strong DNA DSB activity in vitro and in human cell cultures via a unique copper-mediated oxidative mechanism. We also delineate a complete biosynthetic model for colibactin-645, which highlights a unique fate of the aminomalonate-building monomer in forming the C-terminal 5-hydroxy-4-oxazolecarboxylic acid moiety through the activities of both the polyketide synthase ClbO and the amidase ClbL. This work thus provides a molecular basis for colibactin's DNA DSB activity and facilitates further mechanistic study of colibactin-related colorectal cancer incidence and prevention

Open Problems on Central Simple Algebras

We provide a survey of past research and a list of open problems regarding central simple algebras and the Brauer group over a field, intended both for experts and for beginners.Comment: v2 has some small revisions to the text. Some items are re-numbered, compared to v

A systematic review of non-invasive modalities used to identify women with anal incontinence symptoms after childbirth

© 2018, The International Urogynecological Association. Introduction and hypothesis: Anal incontinence following childbirth is prevalent and has a significant impact upon quality of life (QoL). Currently, there is no standard assessment for women after childbirth to identify these symptoms. This systematic review aimed to identify non-invasive modalities used to identify women with anal incontinence following childbirth and assess response and reporting rates of anal incontinence for these modalities. Methods: Ovid Medline, Allied and Complementary Medicine Database (AMED), Cumulative Index of Nursing and Allied Health Literature (CINAHL), Cochrane Collaboration, EMBASE and Web of Science databases were searched for studies using non-invasive modalities published from January 1966 to May 2018 to identify women with anal incontinence following childbirth. Study data including type of modality, response rates and reported prevalence of anal incontinence were extracted and critically appraised. Results: One hundred and nine studies were included from 1602 screened articles. Three types of non-invasive modalities were identified: validated questionnaires/symptom scales (n = 36 studies using 15 different instruments), non-validated questionnaires (n = 50 studies) and patient interviews (n = 23 studies). Mean response rates were 92% up to 6 weeks after childbirth. Non-personalised assessment modalities (validated and non-validated questionnaires) were associated with reporting of higher rates of anal incontinence compared with patient interview at all periods of follow-up after childbirth, which was statistically significant between 6 weeks and 1 year after childbirth (p < 0.05). Conclusions: This systematic review confirms that questionnaires can be used effectively after childbirth to identify women with anal incontinence. Given the methodological limitations associated with non-validated questionnaires, assessing all women following childbirth for pelvic-floor symptomatology, including anal incontinence, using validated questionnaires should be considered

Obesity Associated Hypertension In Admitted Patients: Treating Isolated Systolic Hypertension May Be Short Sighted

The close association of excess adiposity and elevated blood pressure is well documented. The role of obesity as a contributing factor for resistant hypertension, cardiovascular disease, and cerebrovascular disease is recognized. Given that exercise training could be used to treat both obesity and elevated blood pressure when patients are admitted for trauma care, identifying obesity-associated systolic hypertension may help with long-term control of the root causes for these illnesses. PURPOSE: To examine the relationship between body composition, blood pressure, and other measures collected on patient admittance. METHODS: Data were collected from 2,306 consecutive patients admitted to a Level 1 trauma center between July, 2012 and June 2015. Patients with head trauma or traumatic brain injury were not analyzed. Patients were considered obese if their BMI was ≥ 30. Multiple linear regression was used to examine the effect of obesity on blood pressure. Other significant variables were examined from the database that contributed to the prediction model. RESULTS: Significant predictors of systolic hypertension included blood lactate, age, obesity, pulse pressure, pH, %O2 saturation and hemoglobin levels (R=0.464; p\u3c0.001). Holding all other variables constant, obesity was associated with a 9.7 mmHg increase in systolic blood pressure (p=0.009). A mild (3 mmHg) increase in diastolic blood pressure was noted, but was not found to be statistically significant (p=0.172). CONCLUSIONS: The demonstrated relationship between obesity and systolic blood pressure illustrates the need for integrated blood pressure and obesity treatment with exercise training. Therapeutic exercise focused on weight loss goals will likely ameliorate elevated systolic blood pressure. Weight management discussions are challenging, and often avoided by health professionals, but these data show that concomitant antihypertensive medication with therapeutic exercise training may be warranted for prevention of subsequent cardiovascular and cerebrovascular diseases

Total Synthesis Establishes the Biosynthetic Pathway to the Naphterpin and Marinone Natural Products

The naphterpins and marinones are naphthoquinone meroterpenoids with an unusual aromatic oxidation pattern that is biosynthesized from 1,3,6,8‐tetrahydroxynaphthalene (THN). We propose that cryptic halogenation of THN derivatives by vanadium‐dependent chloroperoxidase (VCPO) enzymes is key to this biosynthetic pathway, despite the absence of chlorine in these natural products. This speculation inspired a total synthesis to mimic the naphterpin/marinone biosynthetic pathway. In validation of this biogenetic hypothesis, two VCPOs were discovered that interconvert several of the proposed biosynthetic intermediates.Lauren A. M. Murray, Shaun M. K. McKinnie, Henry P. Pepper, Reto Erni, Zachary D. Miles, Michelle C. Cruickshank, Borja López‐Pérez, Prof. Bradley S. Moore, Jonathan H. Georg

Total synthesis establishes the biosynthetic pathway to the naphterpin and marinone natural products

The naphterpins and marinones are naphthoquinone meroterpenoids with an unusual aromatic oxidation pattern that is biosynthesized from 1,3,6,8‐tetrahydroxynaphthalene (THN). We propose that cryptic halogenation of THN derivatives by vanadium‐dependent chloroperoxidase (VCPO) enzymes is key to this biosynthetic pathway, despite the absence of chlorine in these natural products. This speculation inspired a total synthesis to mimic the naphterpin/marinone biosynthetic pathway. In validation of this biogenetic hypothesis, two VCPOs were discovered that interconvert several of the proposed biosynthetic intermediates.Lauren A. M. Murray, Shaun M. K. McKinnie, Henry P. Pepper, Reto Erni, Zachary D. Miles, Michelle C. Cruickshank, Borja López‐Pérez, Prof. Bradley S. Moore, Jonathan H. Georg

Biosynthesis of Guanitoxin Enables Global Environmental Detection in Freshwater Cyanobacteria

Harmful cyanobacterial blooms (cyanoHABs) cause recurrent toxic events in global watersheds. Although public health agencies monitor the causal toxins of most cyanoHABs and scientists in the field continue developing precise detection and prediction tools, the potent anticholinesterase neurotoxin, guanitoxin, is not presently environmentally monitored. This is largely due to its incompatibility with widely employed analytical methods and instability in the environment, despite guanitoxin being among the most lethal cyanotoxins. Here, we describe the guanitoxin biosynthesis gene cluster and its rigorously characterized nine-step metabolic pathway from l-arginine in the cyanobacterium Sphaerospermopsis torques-reginae ITEP-024. Through environmental sequencing data sets, guanitoxin (gnt) biosynthetic genes are repeatedly detected and expressed in municipal freshwater bodies that have undergone past toxic events. Knowledge of the genetic basis of guanitoxin biosynthesis now allows for environmental, biosynthetic gene monitoring to establish the global scope of this neurotoxic organophosphate