Lens regeneration from cornea of larval Xenopus laevis in the presence of the lens

Development ◽  
1978 ◽  
Vol 48 (1) ◽  
pp. 205-214
Author(s):  
Julie G. Reeve ◽  
Arthur E. Wild
Keyword(s):  
Xenopus Laevis ◽  
Histological Examination ◽  
Cell Layer ◽  
Stage Iv ◽  
Stage Iii ◽  
Posterior Chamber ◽  
Lens Regeneration ◽  
Lens Fibre

In Xenopus laevis tadpoles, wounding of the outer cornea failed to initiate lens regeneration. If both the outer and inner corneas were wounded or if the lens was dislocated, lens regeneration was initiated but failed to continue beyond stage III. However, lensectomy followed by re-implantation of the lens resulted in the regeneration of a fully differentiated lens in several cases, despite the presence of the re-implanted lens. Although some of the regenerates in these eyes were also arrested at stage III, those which attained full lens differentiation, i.e. stage V, developed normally and synthesized crystallins from the onsetof stage IV as indicated by a positive immunofluorescence reaction. Histological examination of the dislocated and re-implanted lenses showed the majority of them to be normal in appearance. Cornea transplanted to the posterior chamber of the eye also regenerated a lens in the presence of the re-implanted lens. All these regenerates underwent lens fibre differentiation to give stage-V regenerates. These findings show that lens regeneration from the cornea can occur in the presence of lens. Results are discussed on the basis that contrary to earlier suggestions, an inhibitory lens factor does not exist in vivo, but rather that a factor for the initiation and maintenance of regeneration emanates from the eye cup and upon wounding of the inner cornea is able to reach the inner cell layer of the outer cornea and initiate lens regeneration.

Post-transcriptional regulation of ornithine decarboxylase in Xenopus laevis oocytes

Development ◽  
1990 ◽  
Vol 110 (3) ◽  
pp. 955-962 ◽  
Author(s):  
T. Bassez ◽  
J. Paris ◽  
F. Omilli ◽  
C. Dorel ◽  
H.B. Osborne
Keyword(s):  
Xenopus Laevis ◽  
Ornithine Decarboxylase ◽  
Stage Iv ◽  
Stage I ◽  
Northern Analysis ◽  
Xenopus Laevis Oocytes ◽  
Temporal Expression ◽  
Post Transcriptional Regulation ◽  
Translational Level

The level at which ornithine decarboxylase expression is regulated in growing oocytes has been investigated. Immunoprecipitation of the in vivo labelled proteins showed that ornithine decarboxylase accumulated less rapidly in stage IV oocytes than in previtellogenic stage I + II oocytes. Quantitative Northern analysis showed that ornithine decarboxylase mRNA is abundant in oocytes (about 8 × 10(8) transcripts/cell) and this number does not significantly change during oogenesis. Polysome analysis showed that this mRNA is present in polysomes in stage I + II oocytes but has passed into puromycin-insensitive mRNP particles by stage IV of oogenesis. Therefore, during the growth phase of oogenesis, ornithine decarboxylase expression is regulated at a translational level. These results are discussed relative to the temporal expression of ornithine decarboxylase and of other proteins whose expression also decreases during oogenesis. In order to perform these experiments, the cDNA (XLODC1) corresponding to Xenopus laevis ornithine decarboxylase mRNA was cloned and sequenced.

An immuno-fluorescent study of lens regeneration in larval Xenopus laevis

Development ◽  
1965 ◽  
Vol 13 (2) ◽  
pp. 171-179
Author(s):  
John C. Campbell
Keyword(s):  
Xenopus Laevis ◽  
Cell Layer ◽  
Morphological Changes ◽  
Posterior Wall ◽  
Corneal Tissue ◽  
Lens Regeneration ◽  
Small Clump

It is well known that several species of amphibia, especially those of the genus Triturus, can regenerate a lens after removal of the original lens from the eye. In most of these species the regenerate develops from the iris (Reyer, 1954), but in larval Xenopus laevis (Overton &Freeman, 1960; Freeman & Overton, 1961, 1962; Freeman, 1963; Campbell, 1963) and possibly in early embryonic stages of Hynobius unnangso (Ikeda, 1936, 1939) the regenerating lens can be formed from corneal tissue. The morphological changes associated with regeneration of the lens from the cornea in X. laevis have been fully described by Freeman (1963), who has shown that the regenerate develops from the inner cell layer of the outer, or ectodermal, cornea, appearing initially as a small clump of cells in the midpupillary region. This aggregate organizes into a vesicle, from the posterior wall of which the primary lens fibres are formed.

scholarly journals The halo model as a versatile tool to predict intrinsic alignments

2020 ◽  
Author(s):  
Maria Cristina Fortuna ◽  
Henk Hoekstra ◽  
Benjamin Joachimi ◽  
Harry Johnston ◽  
Nora Elisa Chisari ◽  
...  
Keyword(s):  
Degrees Of Freedom ◽  
Power Spectra ◽  
Stage Iv ◽  
Stage Iii ◽  
Radial Dependence ◽  
Additional Parameter ◽  
Small Scales ◽  
Cosmic Shear ◽  
Galaxy Populations ◽  
The Impact

Abstract Intrinsic alignments (IAs) of galaxies are an important contaminant for cosmic shear studies, but the modelling is complicated by the dependence of the signal on the source galaxy sample. In this paper, we use the halo model formalism to capture this diversity and examine its implications for Stage-III and Stage-IV cosmic shear surveys. We account for the different IA signatures at large and small scales, as well for the different contributions from central/satellite and red/blue galaxies, and we use realistic mocks to account for the characteristics of the galaxy populations as a function of redshift. We inform our model using the most recent observational findings: we include a luminosity dependence at both large and small scales and a radial dependence of the signal within the halo. We predict the impact of the total IA signal on the lensing angular power spectra, including the current uncertainties from the IA best-fits to illustrate the range of possible impact on the lensing signal: the lack of constraints for fainter galaxies is the main source of uncertainty for our predictions of the IA signal. We investigate how well effective models with limited degrees of freedom can account for the complexity of the IA signal. Although these lead to negligible biases for Stage-III surveys, we find that, for Stage-IV surveys, it is essential to at least include an additional parameter to capture the redshift dependence.

Carboplatin and chlorambucil combination chemotherapy as treatment for patients with ovarian cancer

1994 ◽  
Vol 4 (1) ◽  
pp. 66-71
Author(s):  
B. D. Evans ◽  
P. Chapman ◽  
P. Dady ◽  
G. Forgeson ◽  
D. Perez ◽  
...  
Keyword(s):  
Ovarian Cancer ◽  
Small Volume ◽  
Residual Disease ◽  
Stage Iv ◽  
Complete Response ◽  
Stage Ii ◽  
Stage Iii ◽  
Actuarial Survival ◽  
Moderate Volume ◽  
Grade Iii

Fifty-six patients with ovarian cancer (three stage IC, nine stage II, 33 stage III and II stage IV) were treated with carboplatin 350 mg m−2 i.v. day 1 and chlorambucil orally 0.15 mg kgm−1 days 1–7 inclusive, repeated every 28 days for eight courses. The regimen was well tolerated and was virtually free of nephro- and neurotoxicity. Grade III or IV hematology toxicity occurred in 18 patients but only 31 or 330 courses administered were delayed. Of 40 assessable patients eight achieved a clinical/radiologic complete response and 17 a clinical/radiologic partial response. Actuarial survival at 50 months was 65% for stage II patients, 27% for stage III patients and no stage IV patients survived beyond 20 months. Forty-two per cent of patients with residual disease less 2 cm survived 50 months, compared with 44% of patients with moderate volume (2–5 cm) residual disease and 6% of patients with bulk residual disease. This is an active, well tolerated regimen. However, only patients with small volume residual disease have a significant chance of prolonged survival.

scholarly journals The gravireceptor of Phycomyces. Its development following gravity exposure.

1984 ◽  
Vol 84 (6) ◽  
pp. 845-859 ◽  
Author(s):  
D S Dennison ◽  
W Shropshire
Keyword(s):  
Spatial Relationship ◽  
Stage Iv ◽  
Development Stage ◽  
Stage Ii ◽  
Stage Iii ◽  
Mature Stage ◽  
Early Exposure ◽  
Altered Gravity

The gravitropism of a mature stage IV Phycomyces sporangiophore has a shorter and more uniform latency if the sporangiophore is exposed horizontally to gravity during its earlier development (stage II and stage III). This early exposure to an altered gravitational orientation causes the sporangiophore to develop a gravireceptor as it matures to stage IV and resumes elongation. A technique has been developed to observe the spatial relationship between the vacuole and the protoplasm of a living sporangiophore and to show the reorganization caused by this exposure to altered gravity. Possible gravireceptor mechanisms are discussed.

scholarly journals 300 Final analysis of a prospective, randomized, double-blind, placebo-controlled phase IIb trial of tumor lysate, particle-loaded, dendritic cell vaccine in stage III/IV melanoma: 36-month analysis

2020 ◽  
Vol 8 (Suppl 3) ◽  
pp. A327-A327
Author(s):  
Lexy Adams ◽  
Robert Chick ◽  
Guy Clifton ◽  
Timothy Vreeland ◽  
Patrick McCarthy ◽  
...  
Keyword(s):  
Disease Free Survival ◽  
Stage Iv ◽  
Standard Of Care ◽  
Stage Iii ◽  
Tumor Lysate ◽  
Double Blind ◽  
Free Survival ◽  
Resected Stage ◽  
Disease Free ◽  
Stage Iv Melanoma

BackgroundThe tumor lysate, particle-loaded, dendritic cell (TLPLDC) vaccine is created ex vivo by loading autologous dendritic cells (DC) with yeast cell wall particles (YCWP) containing autologous tumor lysate, thus delivering tumor antigens to the DC cytoplasm via phagocytosis. TLPLDC then activates a robust T cell response against the unique antigens for each patient. The primary analysis of the prospective, randomized, multi-center, double-blind, placebo-controlled phase IIb trial in patients with resected stage III/IV melanoma showed TLPLDC improved 24-month disease-free survival (DFS) in the per-treatment (PT) analysis (patients completing the 6-month primary vaccine series). Here, we examine the secondary endpoint of 36-month DFS and overall survival (OS).MethodsPatients with resected stage III/IV melanoma were randomized 2:1 to TLPLDC vaccine or placebo (autologous DC loaded with empty YCWP). Treatments were given at 0, 1, 2, 6, 12 and 18 months. The protocol was amended to include patients receiving concurrent checkpoint inhibitors (CPIs) to follow changes in standard of care. The co-primary endpoints were 24-month DFS by intention-to-treat (IT) analysis and per-treatment (PT) analysis, with secondary endpoints including 36-month DFS and OS by ITT and PT analysis, pre-specified analysis by stage, and safety as measured by CTCAE v4.03.ResultsOverall, 103 patients received TLPLDC and 41 placebo. In PT analysis, 65 patients received TLPLDC and 32 placebo. Total adverse events (AEs), grade 3+ AEs, and serious AEs (SAEs) were similar in placebo vs TLPLDC groups, with one related SAE per treatment arm. By ITT analysis, 36-month OS was 76.2% for TLPLDC vs 70.3% for placebo (HR 0.72, p=0.437) and 36-month DFS was 35.6% vs 27.1% (HR 0.95, p=0.841). By PT analysis, 36-month DFS was improved with TLPLDC (57.5% vs 35.0%; HR 0.50, p=0.025, figure 1). This effect was even more dramatic in resected stage IV patients (36-month DFS: 60.9% vs 0%; HR 0.12, p=0.001, figure 2).ConclusionsThis phase IIb trial again demonstrates the safety of the TLPLDC vaccine, and an improved 36-month DFS in patients with resected stage III/IV melanoma who complete the primary vaccine series, particularly in the stage IV subgroup. Next, a phase III trial will evaluate the efficacy of TLPLDC vaccine as adjuvant treatment for resected stage IV melanoma, with patients randomized to receive standard of care PD-1 inhibitors + TLPLDC versus PD-1 inhibitors + placebo.Abstract 300 Figure 136-month disease free survival for patients receiving TLPLDC vs placebo by PT analysisAbstract 300 Figure 236-month disease free survival for subset of stage IV melanoma patients receiving TLPLDC vs placebo by PT analysisTrial RegistrationThis is a phase IIb clinical trial registered under NCT02301611Ethics ApprovalThis study was approved by Western IRB, protocol 20141932.

scholarly journals Clinicopathological Profile of Wilms’ Tumour in Children

2014 ◽  
Vol 32 (1) ◽  
pp. 5-8
Author(s):  
M Mazumder ◽  
A Islam ◽  
N Farooq ◽  
M Zaman
Keyword(s):  
Wilms Tumor ◽  
Stage Iv ◽  
Abdominal Distension ◽  
Stage Ii ◽  
Stage Iii ◽  
Wilms Tumour ◽  
Female Ratio ◽  
Male Female Ratio ◽  
Clinicopathological Profile ◽  
Treatment Objective

Introduction: Wilms’ tumor is the most common primary malignant renal tumor of childhood. It is important to pick up the children with wilms’ tumor earlier as early stages has excellent outcomes after treatment. Objective : To find out the common clinical presentations and pathological profile of Wilms’ tumor in children. Methods and Materials : A hospital based prospective study done with twenty diagnosed patients of Wilms tumour enrolled from department of Pediatric haemato-oncology, BSMMU, Dhaka in the period between January to December 2008. Results- The peak incidence of Wilms’ tumor was in 1 to 5 years age group (80%,n=16). Median age at presentation was 49 months with male: female ratio 1.8:1.The most common presentation was abdominal swelling (80%,n=16),followed by flank mass (75%,n=15), abdominal pain (55%,n=11), haematuria (15%,n=3), hypertension (10%,n=2). Thirteen raised from right kidney, ratio of right to left involvement 1.8:1. Histologically 13(65%) patients had triphasic histology having blastemal, stromal and epithelial elements, 7(35%) was biphasic having blastema and epithelia. All had favourable histological pattern. Most patients presented in stage III (55%,n=11) followed by stage II (25%,n=5), Stage IV(10%,n=2), Stage I(10%,n=2). No bilateral presentation. Conclusions : Most of the patients of Wilms’ tumor presented within 1 to 5 years of age(80%) with abdominal distension(80%) and flank mass(75%), few associated with haematuria(15%) and hypertension(10%). Histologically all were favourable and maximum presented in stage III (55%) followed by stage II(25%). DOI: http://dx.doi.org/10.3329/jbcps.v32i1.21015 J Bangladesh Coll Phys Surg 2014; 32: 5-8

Sign in / Sign up

Export Citation Format

Share Document