100 research outputs found
Some observations on Spanner's conception of the placental vascular arrangement and the maternal blood circulation through it
While the development of the vascular system in
other organs is regulated by functional influences
and hereditary factors; in the case of the placenta
the site of implantation in the uterus and the
characteristics of the maternal circulation also
play an important role.
The maternal and foetal blood circulatory paths
within the placenta are regarded from the haemodynamic
point of view as most complicated because the
placental structure is looked upon as being most
complex. Many contradicting views are held in that
respect and many theories are formulated regarding
the placental structure and maternal blood circulation
through it. It is clear that in order to understand
these questions the placental connections with the
uterus and foetus must be studied both with the naked
eye and microscope.
The human placenta according to Grosser is
described as a placenta haemochorialis, thereby
meaning that the foetal chorion is in direct
relationship with the maternal blood.
This fact underlies many risks that the pregnant,
parturient, and puerperal woman undergoes and it
follows that a sound knowledge of the vascular
conditions in the pregnant uterus underlies the
pathology of reproduction. For instance: is the
mechanism of antepartum and postpartum haemorrhage
really understood? or the factors that are
associated with embolus complicating child birth
known? - advancement in obstetrics depends to some
extent on the complete knowledge of this subject.
In 1935 Rudolf Spanner of Kiel brought forward
a new conception formulating a new idea not only of
the structure of the placenta but of the circulation
of the maternal blood through that organ and back to
the uterine veins. His work depended on injection
experiments on the pregnant uterus and placenta.
In the present scope of this work Spanner's work on
the subject has been studied and experiments done
to compare with his results
Morphological and molecular characterization of somaclonal variations in tissue culture-derived banana plants
AbstractIn this study, 40000 tissue culture-derived banana plants (vitroplants) at different growth stages, i.e. acclimatization, nursery and open field of banana (Musa spp.) cultivar ‘Grand Naine’ were screened for somaclonal variations using morphological investigations and molecular characterization. The total detected variants were grouped into 25 off-types (two of them died) in addition to the normal plant. Random Amplified Polymorphic DNA (RAPD) was carried out to study the differences among the normal cultivar ‘Grand Naine’ and its 23 variants using 17 arbitrary primers. Cluster analysis results revealed that ‘winged petiole’ and ‘deformed lamina’ were more related to the normal plant. However, ‘Giant plant’ and ‘weak plant’ related to each other and clustered with normal plant. According to principal coordinate analysis, most of the variants were aggregated nearly, whereas ‘variegated plant’ was separated apart from the other variants. This may reflect the genetic difference between ‘variegated plant’ and the other variants. The results obtained from both molecular and morphological analyses were in contiguous with better resolution when using the PCOORDA analysis than cluster analysis. Thus, it can be said that molecular markers can be used to eliminate the undesirable somaclonal variants from the lab without additional culture of the vitroplants in the field in order to save time and efforts
Fractional calculus model of GATA-switching for regulating the differentiation of a hematopoietic stem cell
This paper deals with the fractional order model for GATA-switching for regulating the differentiation of a hematopoietic stem cell. We give a detailed analysis for the asymptotic stability of the model. The Adams-Bashforth-Moulton algorithm has been used to solve and simulate the system of differential equations
Enhancement of clavulanic acid production by Streptomyces sp MU-NRC77 via mutation and medium optimization
Purpose: To enhance clavulanic acid production using UV-mutagenesis on Streptomyces sp. NRC77.Methods: UV-mutagenesis was used to study the effect of Streptomyces sp. NRC77 on CA production. Phenotypic and genotypic identification methods of the promising mutant strain were characterized. Optimization of the fermentation medium and culture conditions were investigatedResults: Out of the screened mutants, 120A3 mutant isolate was selected as promising. The phenotypic properties of 120A3 mutant showed culture characteristics similar to those of Streptomyces species. Phylogenetic analysis of 16S rRNA gene sequence indicate that this strain has similarity (99 %) to Streptomyces sp.T2-7; therefore it was suggested as Streptomyces sp. MU-NRC77 and has Gen Bank accession no. KT953342.Conclusion: Improvement of CA yield by 48 % was obtained from fermentation medium and culture condition optimization. Further optimization by addition of H2O2 and activated charcoal to the production medium increased CA yield to 646.12 and 682.94 mg/L respectively, i.e., 83 % more than that obtained prior to addition.Keywords: Clavulanic acid, Medium optimization, Phenotypic and Genotypic identification, Streptomyces sp. MU-NRC77, UV-Mutagenesi
Comparative studies of antifugal potentialities for some natural plant oils against different fungi isolated from poultry
Monotone iterative procedure and systems of a finite number of nonlinear fractional differential equations
The aim of the paper is to present a nontrivial and natural extension of the
comparison result and the monotone iterative procedure based on upper and lower
solutions, which were recently established in (Wang et al. in Appl. Math. Lett.
25:1019-1024, 2012), to the case of any finite number of nonlinear fractional
differential equations.The author is very grateful to the reviewers for the remarks, which improved the final version of the manuscript. This
article was financially supported by University of Łódź as a part of donation for the research activities aimed at the
development of young scientists, grant no. 545/1117
Existence of solutions for nonlinear second-order q-difference equations with first-order q-derivatives
A first-in-human clinical study of a new SP-B and SP-C enriched synthetic surfactant (CHF5633) in preterm babies with respiratory distress syndrome
Objective CHF5633 (Chiesi Farmaceutici S.p.A., Parma, Italy) is the first fully synthetic surfactant enriched by peptide analogues of two human surfactant proteins. We planned to assess safety and tolerability of CHF5633 and explore preliminary efficacy. Design Multicentre cohort study. Patients Forty infants from 27+0 to 33+6 weeks gestation with respiratory distress syndrome requiring fraction of inspired oxygen (FiO2) ≥0.35 were treated with a single dose of CHF5633 within 48 hours after birth. The first 20 received 100 mg/kg and the second 20 received 200 mg/kg. Outcome measures Adverse events (AEs) and adverse drug reactions (ADRs) were monitored with complications of prematurity considered AEs if occurring after dosing. Systemic absorption and immunogenicity were assessed. Efficacy was assessed by change in FiO2 after dosing and need for poractant-alfa rescue. Results Rapid and sustained improvements in FiO2 were observed in 39 (98%) infants. One responded neither to CHF5633 nor two poractant-alfa doses. A total of 79 AEs were experienced by 19 infants in the 100 mg/kg cohort and 53 AEs by 20 infants in the 200 mg/kg cohort. Most AEs were expected complications of prematurity. Two unrelated serious AEs occurred in the second cohort. One infant died of necrotising enterocolitis and another developed viral bronchiolitis after discharge. The single ADR was an episode of transient endotracheal tube obstruction following a 200 mg/kg dose. Neither systemic absorption, nor antibody development to either peptide was detected. Conclusions Both CHF5633 doses were well tolerated and showed promising clinical efficacy profile. These encouraging data provide a basis for ongoing randomised controlled trials
Three-point boundary value problems for nonlinear second-order impulsive q-difference equations
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