The role of the genome in the development of the haploid syndrome in Anura

Development ◽  
1966 ◽  
Vol 16 (3) ◽  
pp. 559-568
Author(s):  
Louie Hamilton
Keyword(s):  
Good Evidence ◽  
Contributory Factor ◽  
Diploid Nucleus ◽  
Haploid Nucleus ◽  
Recessive Lethal ◽  
Partial Failure ◽  
Lethal Genes

The problem of the factors involved in the development of the haploid syndrome in anuran embryos is as yet unsolved. It is known that about 90 % of all haploid frog embryos develop the haploid syndrome, which is characterized by the presence of oedema and sluggishness, by reduction in pigmentation and in the efficiency of the heart and circulation, and by a partial failure of the gut to coil and of muscle to differentiate. The two most favoured explanations of the development of the haploid syndrome have been nucleocytoplasmic imbalance, since a haploid nucleus is only half the size of a diploid nucleus in the same-sized egg, and unmasked recessive lethal genes. There is good evidence that an abnormal nucleocytoplasmic ratio is an important contributory factor in the development of the haploid syndrome. Briggs (1949) compared populations of haploids developing from large and small eggs and Subtelny (1958) compared the development of haploids and homozygous diploids which possessed a reduplicated set of haploid chromosomes.

scholarly journals Steroid Sulphatase and Its Inhibitors: Past, Present and Future

Molecules ◽  
2021 ◽  
Vol 26 (10) ◽  
pp. 2852
Author(s):  
Paul A. Foster
Keyword(s):  
Good Evidence ◽  
The Past ◽  
Steroid Sulphatase ◽  
University Of Oxford ◽  
Therapeutic Value ◽  
Breast And Prostate Cancer ◽  
The University ◽  
Further Development ◽  
Hydrolysis Of

Steroid sulphatase (STS), involved in the hydrolysis of steroid sulphates, plays an important role in the formation of both active oestrogens and androgens. Since these steroids significantly impact the proliferation of both oestrogen- and androgen-dependent cancers, many research groups over the past 30 years have designed and developed STS inhibitors. One of the main contributors to this field has been Prof. Barry Potter, previously at the University of Bath and now at the University of Oxford. Upon Prof. Potter’s imminent retirement, this review takes a look back at the work on STS inhibitors and their contribution to our understanding of sulphate biology and as potential therapeutic agents in hormone-dependent disease. A number of potent STS inhibitors have now been developed, one of which, Irosustat (STX64, 667Coumate, BN83495), remains the only one to have completed phase I/II clinical trials against numerous indications (breast, prostate, endometrial). These studies have provided new insights into the origins of androgens and oestrogens in women and men. In addition to the therapeutic role of STS inhibition in breast and prostate cancer, there is now good evidence to suggest they may also provide benefits in patients with colorectal and ovarian cancer, and in treating endometriosis. To explore the potential of STS inhibitors further, a number of second- and third-generation inhibitors have been developed, together with single molecules that possess aromatase–STS inhibitory properties. The further development of potent STS inhibitors will allow their potential therapeutic value to be explored in a variety of hormone-dependent cancers and possibly other non-oncological conditions.

Pressure-flow relations in coronary circulation

1990 ◽  
Vol 70 (2) ◽  
pp. 331-390 ◽  
Author(s):  
J. I. Hoffman ◽  
J. A. Spaan
Keyword(s):  
Coronary Vessels ◽  
Good Evidence ◽  
The Body ◽  
Vascular Compression ◽  
Exact Nature ◽  
Coronary Veins ◽  
Collapsible Tubes ◽  
External Pressures ◽  
Flow Through

The blood vessels that run on the surface of the heart and through its muscle are compliant tubes that can be affected by the pressures external to them in at least two ways. If the pressure outside these vessels is higher than the pressure at their downstream ends, the vessels may collapse and become Starling resistors or vascular waterfalls. If this happens, the flow through these vessels depends on their resistance and the pressure drop from their inflow to the pressure around them and is independent of the actual downstream pressure. In the first part of this review, the physics of collapsible tubes is described, and the possible occurrences of vascular waterfalls in the body is evaluated. There is good evidence that waterfall behavior is seen in collateral coronary arteries and in extramural coronary veins, but the evidence that intramural coronary vessels act like vascular waterfalls is inconclusive. There is no doubt that in systole there are high tissue pressures around the intramyocardial vessels, particularly in the subendocardial muscle of the left ventricle. The exact nature and values of the forces that act at the surface of the small intramural vessels, however, are still not known. We are not certain whether radial (compressive) or circumferential and longitudinal (tensile) stresses are the major causes of vascular compression; the role of collagen struts in modifying the reaction of vessel walls to external pressures is unknown but possibly important; direct examination of small subepicardial vessels has failed to show vascular collapse. One of the arguments in favor of intramyocardial vascular waterfalls has been that during a long diastole the flow in the left coronary artery decreases and reaches zero when coronary arterial pressure is still high: it can be as much as 50 mmHg in the autoregulating left coronary arterial bed and approximately 15-20 mmHg even when the vessels have been maximally dilated. These high zero flow pressures, especially during maximal vasodilatation, have been regarded as indicating a high back pressure to flow that is due to waterfall behavior of vessels that are exposed to tissue pressures.(ABSTRACT TRUNCATED AT 400 WORDS)

scholarly journals Protective role of methanol extracts of Gentiana asclepiadea L. and G. cruciata L. against genotoxic damage induced by ethyl methanesulfonate

Genetika ◽  
2013 ◽  
Vol 45 (2) ◽  
pp. 329-340 ◽  
Author(s):  
Sanja Matic ◽  
Snezana Stanic ◽  
Slavica Solujic ◽  
Nevena Stankovic ◽  
Milan Mladenovic ◽  
...  
Keyword(s):  
Aerial Part ◽  
Protective Role ◽  
Negative Control ◽  
Ethyl Methanesulfonate ◽  
Recessive Lethal ◽  
Methanol Extracts ◽  
Strong Mutagen ◽  
Gentiana Cruciata

The methanol extracts from the underground and aerial part of the two species of Gentiana genus, Gentiana asclepiadea L. and Gentiana cruciata L. from Serbia, were investigated for their antigenotoxic activity against wellestablished mutagenic agent ethyl methanesulfonate (EMS) using the in vivo sexlinked recessive lethal (SLRL) test on Drosophila melanogaster. For this purpose, three days old Canton S males were treated with the potent mutagen EMS in concentration of 0.75 ppm, alone and combined with methanol extracts obtained from underground or aerial part of G. asclepiadea and G. cruciata in concentration of 5%, separately. Although EMS in concentration of 0.75 ppm increased the mutation frequency in all three broods, post-treatments with methanol extracts obtained from the underground and aerial part of G. asclepiadea and G. cruciata in concentration of 5%, respectively, drastically reduced the frequency of sex-linked recessive lethal mutations induced by EMS. Compared to the sucrose, as a negative control, methanol extract obtained from underground part of G. cruciata showed the most potent antigenotoxic activity. Extracts from the underground and aerial part of the two species of Gentiana genus, G. asclepiadea L. and G. cruciata L. from Serbia used in our experiments showed a clear antimutagenic effect, reducing the frequency of mutations induced by a strong mutagen such as EMS.

scholarly journals Family Dyadic: Anima Animas

2020 ◽  
Author(s):  
Naveed Shibli ◽  
Momna Rizwan
Keyword(s):  
Significant Relationship ◽  
Dyadic Adjustment ◽  
Contributory Factor ◽  
Self Disclosure ◽  
Dyadic Adjustment Scale ◽  
Nuclear Families ◽  
Masculinity And Femininity ◽  
Family Types ◽  
Feminine Self

<p>In a randomized groups design 50 couples including 50 husbands and 50 wives belonging to joint and nuclear families were tested to study the presence of anima and animas contributory role in both spouses towards family dyadic and it relationship with joint and nuclear families. Dyadic Adjustment Scale (DAS) for family dyadic and The Masculine and Feminine Self-Disclosure Scale (MFSDS) were used to measure participants’ masculinity (anima) and femininity (animus) role in both spouses as contributory factor toward family dyadic in both family types. It was assumed that some useful information would emerge? SPSS was used for responses analysis. Significant .correlation between MFSDS .532<sup>**</sup>and DAS.657<sup>**</sup> found. MFSDS predicted DAS significantly <i>F</i> (<i>df</i> = 97) = 54.37,<i> p </i><.001. Traditional binary role were not much clear, a non significant relationship was found between family types and participants scores on both tests. The findings pointed toward further dyadic focus for contributory role of masculinity and femininity levels of spouses in both family types. </p>

Abstract WP164: Role of Risk Factors in the Paradoxical Effect of Smoking on Peri-procedural Stroke in SAMMPRIS

Stroke ◽  
2013 ◽  
Vol 44 (suppl_1) ◽  
Author(s):  
Christine A Holmstedt ◽  
Tanya N Turan ◽  
Michael J Lynn ◽  
Bethany F Lane ◽  
Jean Montgomery ◽  
...  
Keyword(s):  
Risk Factors ◽  
Odds Ratio ◽  
Multivariate Analyses ◽  
Smoking Status ◽  
Active Form ◽  
Intracranial Stenosis ◽  
Contributory Factor ◽  
Increased Risk ◽  
Never Smokers

Background: A previous SAMMPRIS analysis of patients randomized to stenting showed that peri-procedural ischemic infarcts were significantly associated with diabetes, basilar stenosis, age, and smoking status with never smokers having a higher risk (odds ratio = 8.8, p< 0.001). We sought to determine if this finding could be due to a higher burden of other risk factors in never smokers. Method: Baseline features in 213 patients undergoing stenting in SAMMPRIS were compared between never smokers vs. former and current smokers in univariate and multivariate analyses. Logistic regression was used to determine the effect of smoking on peri-procedural ischemic infarcts after adjusting for factors related to smoking. Data: Univariate results are shown in Table 1. Never smokers were significantly (P<0.05) more likely to be female, diabetic, hypertensive, and have another intracranial stenosis, but in multivariate analyses only hypertension and another intracranial stenosis remained significantly (P<0.05) associated with smoking status. In a multivariate model that incorporated hypertension and another intracranial stenosis along with smoking status, diabetes, basilar stenosis, and age, smoking status remained significant with an increased risk among patients who never smoked (odds ratio = 5.3, p = 0.005). Conclusion: While never smokers had significantly higher rates of some risk factors compared to active or previous smokers, these risk factors do not explain all the increased risk of early stroke in never smokers after stenting in SAMMPRIS. Another contributory factor may be that smoking accelerates the conversion of clopidogrel to its active form.

Biosystematic studies in the Stylidium crassifolium species complex (Stylidiaceae)

1979 ◽  
Vol 27 (1) ◽  
pp. 27 ◽  
Author(s):  
BJ Banyard ◽  
SH James
Keyword(s):  
Species Complex ◽  
Genetic System ◽  
Lethal Gene ◽  
Great Efficiency ◽  
Intermediate Species ◽  
Gene Arrays ◽  
Recessive Lethal ◽  
Tetraploid Form ◽  
Diploid Populations ◽  
Lethal Genes

Stylidium elongatum Benth. (n = 13, 26) and Stylidium crassifolium R. Br. (n = 14, 28) have been restored to specific status and a morphologically intermediate species, Stylidium confluens sp. nov. (n = 14), is described. Polyploid entities in the complex have not been given taxonomic ranks although the tetraploid form of elongatum may be considered worthy of subspecific rank, as it is ecologically distinct and contiguously allopatric to its progenitor and to confluens, forming a buffer between these two diploid entities. Tetraploid populations in crassifolium occur within the distributional range of the diploid. All three species carry recessive lethal gene arrays which eliminate the products of self-pollination with great efficiency and result in crosses between close populations yielding seed more effectively than crosses within populations. There is evidence that interpopulational coadaptation may break down with increasing distance between populations. Polyploidy in crassifolium is probably a conservative response in the genetic system of a species where concentrations of lethal genes in small diploid populations became disadvantageous.

scholarly journals The venous ulcer continues to be a clinical challenge: an update

2018 ◽  
Vol 6 ◽  
Author(s):  
Ting Xie ◽  
Junna Ye ◽  
Kittipan Rerkasem ◽  
Rajgopal Mani
Keyword(s):  
Microvascular Dysfunction ◽  
Venous Ulcer ◽  
Good Evidence ◽  
Venous Hypertension ◽  
Diagnostic Methods ◽  
Systematic Analysis ◽  
Venous Ulcers ◽  
Clinical Challenge ◽  
Treatment Procedures

Abstract Venous ulcers are a common chronic problem in many countries especially in Northern Europe and USA. The overall prevalence of this condition is 1% rising to 3% in the over 65 years of age. Over the last 25 years, there have been many developments applicable to its diagnosis and treatment. These advances, notwithstanding healing response and recurrence, are variable, and the venous ulcer continues to be a clinical challenge. The pathogenesis of venous ulcers is unrelieved or ambulatory venous hypertension resulting mostly from deep venous thrombosis leading to venous incompetence, lipodermatosclerosis, leucocyte plugging of the capillaries, tissue hypoxia and microvascular dysfunction. It is not known what initiates venous ulcers. Triggers vary from trauma of the lower extremity to scratching to relieve itchy skin over the ankle region. Venous ulcers can be painful, and this condition presents an increasing burden of care. A systematic analysis of the role of technology used for diagnosis and management strongly supports the use of compression as a mainstay of standardised care. It further shows good evidence for the potential of some treatment procedures to accelerate healing. This article reviews the pathogenetic mechanisms, current diagnostic methods and standard care and its limitations.

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