A unique immuno-stimulant steroidal sapogenin acid from the roots of Asparagus racemosus

A new steroidal sapogenin molecule 1 having unique characteristics, 21-nor and unusual C19 carboxylic acid has been isolated from the roots of Asparagus racemosus. On the basis of chemical evidence, extensive spectroscopic analysis including two dimensional (2D) NMR and X-ray studies of single crystal, the structure of 1 was determined as (1S,2R,3S,8S,9S,10S,13S,14S,16S,17R,22R,25R)-21-nor-18β,27α-dimethyl-1β,2β,3β-trihydroxy-25-spirost-4-en-19β-oic acid. 1 crystallizes in monoclinic space group P2₁ with a = 9.295(2), b = 11.238(2), c = 11.376(2) Å; β = 91.993(4)°, Z = 2, D_cal = 1.344 Mg/m³. The structure was solved by direct methods and refined by full-matrix least-squares procedure to a final R-value of 0.0561 for 4064 observed reflections. 1 was tested against the type of immune responses generated during treatment in normal and immune-suppressed animals and detailed biological activity evaluation suggests it to be a potent immunostimulator.     

Weekly osimertinib dosing prevents EGFR mutant tumor cells destined to home mouse lungs

The recently conducted ADAURA trial concludes daily dosing of adjuvant osimertinib, a third-generation EGFR tyrosine kinase inhibitor (TKI), improves disease-free survival with stage IB/II/IIIA EGFR -mutated non-small cell lung cancer patients in comparison to placebo. We have developed a preclinical orthotopic mouse model, using luciferase tagged lung adenocarcinoma cells harboring EGFR TKI sensitive exon 19 deletion to model and extend trial implications comparing a weekly vs daily dosing outcome of osimertinib to a first-generation TKI- erlotinib. We find that 100% of mice in both the groups receiving osimertinib daily or weekly before injection of cells show a complete absence of homing of cells in mice''s lungs from day three until day 18 post-injection of cells. On the other hand, 25% and 75% of mice receiving erlotinib daily and weekly before injecting cells show homing of cells to the lungs. The tumors observed in the lungs, when dissected at day 30, confirmed the colonization of the injected cells homing to the organ. Thus, our study establishes the efficacy of pretreatment with osimertinib in reducing tumor cells'' homing to mouse lungs in an in vivo mouse model.     

Ciliary neurotrophic factor: a survival and differentiation inducer in human retinal progenitors

Retinitis pigmentosa, age-related macular degeneration, and Parkinson’s disease remain major problems in the field of medicine. Some of the strategies being explored for treatment include replacement of damaged tissue by transplantation of healthy tissues or progenitor cells and delivery of neurotrophins to rescue degenerating tissue. One of the neurotrophins with promise is the ciliary neurotrophic factor (CNTF). In this study, we report the role played by CNTF in retinal cell differentiation and survival in retinal progenitors. We found that CNTF is a survival factor for multipotential human retinal cells and increased cell survival by 50%, over a 7-d period, under serum-free conditions, as determined by apoptotic assays (immunohistochemistry and flow cytometry). This effect is dose dependent with a maximum survival at a CNTF concentration of 20 ng/ml. We also report that CNTF might be a cell commitment factor, directing the differentiation mainly toward large multipolar cells with ganglionic and amacrine phenotype. These cells express tyrosine hydroxylase (amacrine cells) as well as, thy 1.1 and neuron-specific enolase (ganglionic cells). Additionally, there was also an increase in protein kinase C alpha, a protein expressed in rod and cone bipolars as well as cone photoreceptors and calbindin, a protein expressed in cone photoreceptors and horizontal cells. In our studies, CNTF doubled the number of cells with ganglionic phenotypes, and basic fibroblast growth factor doubled the number of cells with photoreceptor phenotype. Additionally, CNTF induced a subset of progenitors to undergo multiple rounds of cell division before acquiring the large multipolar ganglionic phenotype. Our conclusion is that CNTF could be an agent that has therapeutic potential and possibly induces differentiation of large multipolar ganglionic phenotype in a subset of progenitors.     

Uses and limitations of monoclonal antibodies to Giardia lamblia-specific 66-kDa copro-antigen in copro-immunodiagnosis of giardiasis

Abstract Antigen-capture enzyme-linked immunosorbent assay for the detection of Giardia lamblia -specific antigen in stool eluates from clinical subjects employing monoclonal antibody directed at 66-kDa G. lamblia copro-antigen has been evaluated. The G. lamblia copro-antigen was detected in 67% (31 of the 46 cases) of stool eluates from clinical cases, while none of the stool eluates from subjects with other intestinal parasites or from apparently healthy individuals, had detectable levels of G. lamblia copro-antigen. Monoclonal antibodies secreted by clones B4C5 and D3F4 recognised the periodate-sensitive and -insensitive epitopes of 66-kDa G. lamblia specific copro-antigen, respectively. Eight (73%) of the 11 symptomatic cases of giardiasis had trypsin-/periodate-sensitive epitopes of 66-kDa copro-antigen while 9 (92%) of 11 of the symptomatic cases and asymptomatic G. lamblia cyst carriers had trypsin-sensitive periodate-insensitive G. lamblia specific copro-antigen. The data tend to suggest that detection of periodate-insensitive epitopes of G. lamblia copro-antigen would indicate the presence of the parasite while the detection of periodate sensitive epitopes of G. lamblia copro-antigen would suggest symptomatic active giardial infection.     

Glutamine synthetase induction in chick embryo retina monolayers

Induction of glutamine synthetase (GS) by cortisol has been shown to occur in monolayer cultures of cells obtained by enzymatic dissociation of retinas from 8- and 12-day-old chick embryos with papain (0.1%) or trypsin (0.25%). Although essentially single cells when plated, monolayers obtained by enzymatic dissociation show significant aggregation by 4--6 h. Monolayers prepared by mechanical dispersion (cells forced through successively smaller gage needles) are minimally inducible, perhaps owing to poor viability in such cultures. Storage at 4 degrees C for 24 h prior to treatment with cortisol significantly elevated both basal GS activity and inducibility in whole (but not in monolayer) retina cultures.     

Cyclical changes in the pituitary gonadotrophs (GTH cells) in relation to the testicular cycle in Puntius sarana (Hamilton)

The pituitary gland of Puntius sarana is of the leptobasic type and has three subdivisions--a proximal pars distalis (PPD), a rostral pars distalis (RPD) and a pars intermedia (PI) arranged vertically one below the other. The gonadotrophs (GTH cells) of the PPD were identified by their PAS, ATh, AF, aniline blue and alcian blue positivity and by their immunoreactivity to ovine anti-LH beta-subunit, anti-salmon GTH and anti-silver carp GTH. The testes of Puntius sarana have been classified as the "unrestricted type". The morphological, histological and histometric findings indicate that the testing passes through four distinct stages--preparatory, fully mature, spawning and spent. Spermatogenesis begins in January and continues up to July. The spawning season lasts from late July until October. Cyclical changes in the gonadotrophs correlate well with changes in the testes. The histometric data show that the GTH cells attain maximum values (size and number) during the breeding season. The peak values for testicular weight, lobule diameter, the gonadosomatic index (GSI) and the sperm concentration in the testes, and the number, size and amount of secretory material in the cytoplasm of the gonadotrophs, coincide with the time of maximum environmental temperature and the longest days.