Airway Epithelium: A Neglected but Crucial Cell Type in Asthma Pathobiology

The features of allergic asthma are believed to be mediated mostly through the Th2 immune response. In this Th2-dominant concept, the airway epithelium is presented as the helpless victim of Th2 cytokines. However, this Th2-dominant concept is inadequate to fill some of the vital knowledge gaps in asthma pathogenesis, like the poor correlation between airway inflammation and airway remodeling and severe asthma endotypes, including Th2-low asthma, therapy resistance, etc. Since the discovery of type 2 innate lymphoid cells in 2010, asthma researchers started believing in that the airway epithelium played a crucial role, as alarmins, which are the inducers of ILC2, are almost exclusively secreted by the airway epithelium. This underscores the eminence of airway epithelium in asthma pathogenesis. However, the airway epithelium has a bipartite functionality in sustaining healthy lung homeostasis and asthmatic lungs. On the one hand, the airway epithelium maintains lung homeostasis against environmental irritants/pollutants with the aid of its various armamentaria, including its chemosensory apparatus and detoxification system. Alternatively, it induces an ILC2-mediated type 2 immune response through alarmins to amplify the inflammatory response. However, the available evidence indicates that restoring epithelial health may attenuate asthmatic features. Thus, we conjecture that an epithelium-driven concept in asthma pathogenesis could fill most of the gaps in current asthma knowledge, and the incorporation of epithelial-protective agents to enhance the robustness of the epithelial barrier and the combative capacity of the airway epithelium against exogenous irritants/allergens may mitigate asthma incidence and severity, resulting in better asthma control.

International Nosocomial Infection Control Consortium (INICC) report, data summary of 45 countries for 2012-2017: Device-associated module

BACKGROUND

We report the results of International Nosocomial Infection Control Consortium (INICC) surveillance study from January 2012 to December 2017 in 523 intensive care units (ICUs) in 45 countries from Latin America, Europe, Eastern Mediterranean, Southeast Asia, and Western Pacific.

METHODS

During the 6-year study period, prospective data from 532,483 ICU patients hospitalized in 242 hospitals, for an aggregate of 2,197,304 patient days, were collected through the INICC Surveillance Online System (ISOS). The Centers for Disease Control and Prevention-National Healthcare Safety Network (CDC-NHSN) definitions for device-associated health care-associated infection (DA-HAI) were applied.

RESULTS

Although device use in INICC ICUs was similar to that reported from CDC-NHSN ICUs, DA-HAI rates were higher in the INICC ICUs: in the medical-surgical ICUs, the pooled central line-associated bloodstream infection rate was higher (5.05 vs 0.8 per 1,000 central line-days); the ventilator-associated pneumonia rate was also higher (14.1 vs 0.9 per 1,000 ventilator-days,), as well as the rate of catheter-associated urinary tract infection (5.1 vs 1.7 per 1,000 catheter-days). From blood cultures samples, frequencies of resistance, such as of Pseudomonas aeruginosa to piperacillin-tazobactam (33.0% vs 18.3%), were also higher.

CONCLUSIONS

Despite a significant trend toward the reduction in INICC ICUs, DA-HAI rates are still much higher compared with CDC-NHSN's ICUs representing the developed world. It is INICC's main goal to provide basic and cost-effective resources, through the INICC Surveillance Online System to tackle the burden of DA-HAIs effectively.

Machine vision based evaluation of impact of light emitting diodes (LEDs) on shoot regeneration and the effect of spectral quality on phenolic content and antioxidant capacity in Swertia chirata

The present study demonstrates the influence of LED irradiance of various wavelengths on shoot regeneration, biomass accumulation, photosynthetic pigment contents, and antioxidant potentials of Swertia chirata - a critically endangered medicinal plant. Mixed treatment of blue (BL) and red LEDs (RL) in equal proportion (1:1) significantly improved the shoot regeneration response. A machine vision system was developed to assess the shoot regeneration potential under different lighting treatments. Regenerated shoots exposed under BL:RL (1:1) exhibited higher biomass accumulation and canopy development compared to other lighting treatments. Improved canopy growth was evident from the increase in the area, major axis, minor axis, convex area, equivalent diameter and perimeter of regenerated shoot clusters. A higher correlation of dry weight (DW) was noted with the image feature, weighted density (WD) than the fresh weight (FW) in all the LED treated cultures. The significant correlation between DW and WD implies that the image feature WD can be adopted as a non-invasive approach for measuring biomass accumulation as well as detecting hyperhydricity. The developed machine vision approach provides a new direction in the evaluation of shoot organogenesis that displayed features including both shoot multiplication and canopy development. Chlorophyll and carotenoid contents of the regenerated shoots were found to be higher under BL:RL (1:1) than the other treatments. Supplementation of RL led to a reduction in the pigment contents. Spectral quality of lights also significantly influenced the accumulation of total phenolics, flavonoids and flavonols. Cultures exposed under BL exhibited the maximum accumulation of polyphenols. A similar effect of spectral quality was observed with the antioxidant capacity and reducing power potential of leaf extract. The findings demonstrate the ability of LEDs in inducing shoot regeneration as well as accumulation of phenolic antioxidants and suggest that the proportion of blue and red LEDs is an important factor in achieving the optimum response.

Laser-plasma-based Space Radiation Reproduction in the Laboratory

Space radiation is a great danger to electronics and astronauts onboard space vessels. The spectral flux of space electrons, protons and ions for example in the radiation belts is inherently broadband, but this is a feature hard to mimic with conventional radiation sources. Using laser-plasma-accelerators, we reproduced relativistic, broadband radiation belt flux in the laboratory, and used this man-made space radiation to test the radiation hardness of space electronics. Such close mimicking of space radiation in the lab builds on the inherent ability of laser-plasma-accelerators to directly produce broadband Maxwellian-type particle flux, akin to conditions in space. In combination with the established sources, utilisation of the growing number of ever more potent laser-plasma-accelerator facilities worldwide as complementary space radiation sources can help alleviate the shortage of available beamtime and may allow for development of advanced test procedures, paving the way towards higher reliability of space missions.

Nanodelivery of Parthenolide Using Functionalized Nanographene Enhances its Anticancer Activity

Advances in anticancer chemotherapy have been hindered by the lack of biocompatibility of new prospective drugs. One significant challenge concerns water insolubility, which compromises the bioavailability of the drugs leading to increased dosage and higher systemic toxicity. To overcome these problems, nanodelivery has been established as a promising approach for increasing the efficacy and lowering the required dosage of chemotherapeutics. The naturally derived compound, parthenolide (PTL), is known for its anti-inflammatory and anticancer activity, but its poor water solubility limits its clinical value. In the present study, we have used carboxyl-functionalized nanographene (fGn) delivery to overcome the extreme hydrophobicity of this drug. A water-soluble PTL analog, dimethylamino parthenolide (DMAPT), was also examined for comparison with the anticancer efficacy of our PTL-fGn complex. Delivery by fGn was found to increase the anticancer/apoptotic effects of PTL (but not DMAPT) when delivered to the human pancreatic cancer cell line, Panc-1. The IC50 value for PTL decreased from 39 µM to 9.5 µM when delivered as a mixture with fGn. The IC50 of DMAPT did not decrease when delivered as DMAPT-fGn and was significantly higher than that for PTL-fGn. There were significant increases in ROS formation and in mitochondrial membrane disruption in Panc-1 cells after PTL-fGn treatment as compared to PTL treatment, alone. Increases in toxicity were also seen with apoptosis detection assays using flow cytometry, ethidium bromide/acridine orange/DAPI staining, and TUNEL. Thus, fGn delivery was successfully used to overcome the poor water solubility of PTL, providing a strategy for improving the effectiveness of this anticancer agent.

Potential contribution of monoamine oxidase a gene variants in ADHD and behavioral co-morbidities: scenario in eastern Indian probands

Attention deficit hyperactivity disorder (ADHD) is the most frequently diagnosed behavioral disorder in children with a high frequency of co-morbid conditions like conduct disorder (CD) and oppositional defiant disorder (ODD). These traits are controlled by neurotransmitters like dopamine, serotonin and norepinephrine. Monoamine oxidase A (MAOA), a mitochondrial enzyme involved in the degradation of amines, has been reported to be associated with aggression, impulsivity, depression, and mood changes. We hypothesized that MAOA can have a potential role in ADHD associated CD/ODD and analyzed 24 markers in a group of Indo-Caucasoid subjects. ADHD probands and controls (N = 150 each) matched for ethnicity and gender were recruited following the Diagnostic and Statistical Manual for Mental Disorders-IV. Appropriate scales were used for measuring CD and ODD traits. Markers were genotyped by PCR-based methods and data obtained analyzed using the Cocaphase program under UNPHASED. Only eight markers were found to be polymorphic. rs6323 "G" allele showed higher frequencies in ADHD (P = 0.0023), ADHD + CD (P = 0.03) and ADHD + ODD (P = 0.01) as compared to controls. Haplotype analysis revealed statistically significant difference for three haplotypes in ADHD cases (P < 0.02). Statistically significant differences were also noticed for haplotypes in ADHD + CD and ADHD + ODD cases (P < 0.01). LD analysis showed significant variation in different groups. Multidimensionality reduction analysis showed independent as well as interactive effects of markers. Genotypes showed correlation with behavioral problems in ADHD and ADHD + CD. We interpret that MAOA gene variants may contribute to the etiology of ADHD as well as associated co-morbid CD and ODD in this ethnic group.

Observation of gigawatt-class THz pulses from a compact laser-driven particle accelerator

We report the observation of subpicosecond terahertz (T-ray) pulses with energies ≥460 μJ from a laser-driven ion accelerator, thus rendering the peak power of the source higher even than that of state-of-the-art synchrotrons. Experiments were performed with intense laser pulses (up to 5×10(19) W/cm(2)) to irradiate thin metal foil targets. Ion spectra measured simultaneously showed a square law dependence of the T-ray yield on particle number. Two-dimensional particle-in-cell simulations show the presence of transient currents at the target rear surface which could be responsible for the strong T-ray emission.

A Griffiths-like phase in antiferromagnetic R0.5Eu0.5MnO3 (R = Pr, Nd, Sm)

We report a Griffiths-like phase in isovalent doped rare-earth manganites R(0.5)Eu(0.5)MnO(3) (R = Pr, Nd, Sm). Rietveld refinement of the structural data reveals strong orthorhombic and Jahn-Teller distortions. The dc and ac magnetic studies nicely demonstrate aspects of Griffiths phase-like behaviour. The presence of short range ferromagnetically correlated spin clusters is observed above the antiferromagnetic transition temperature. A disorder driven phase inhomogeneity arising from strong structural distortion is the possible origin of this behaviour.

Carbon nanotubes enhance the internalization of drugs by cancer cells and decrease their chemoresistance to cytostatics

Etoposide is a semisynthetic, chemotherapeutic drug widely recommended to treat an extensive range of human cancers. Our studies indicate that, while etoposide is capable of killing human cancer cells, exposure to single-walled carbon nanotubes (SWCNTs) and etoposide results in enhanced cell death that appears to be synergistic and not merely additive. In this study, we used high pressure liquid chromatography and mass spectrometry to quantify the internal effective dose of etoposide when the human pancreatic cancer cell (PANC-1) was exposed to the combination of these agents. Our results unequivocally indicate that SWCNTs improve etoposide uptake and increase its capacity to kill cancer cells. We suggest that a combination of SWCNTs and etoposide may prove to be a more efficient chemotherapeutic protocol, especially because of the potential to lower toxic drug doses to levels that may be useful in decreasing adverse side effects, as well as in lowering the probability of inducing chemoresistance in exposed cancer cells.

Nonlinearity exponent of ac conductivity in disordered systems

We measured the real part of ac conductance Σ(x,f) or Σ(T,f) of iron-doped mixed-valent polycrystalline manganite oxides LaMn(1-x)Fe(x)O(3) as a function of frequency f by varying initial conductance Σ(0) by quenched disorder x at a fixed temperature T (room) and by temperature T at a fixed quenched disorder x. At a fixed temperature T, Σ(x,f) of a sample with fixed x remains almost constant at its zero-frequency dc value Σ(0) at lower frequency. With increase in f, Σ(x,f) increases slowly from Σ(0) and finally increases rapidly following a power law with an exponent s at high frequency. Scaled appropriately, the data for Σ(T,f) and Σ(x,f) fall on the same universal curve, indicating the existence of a general scaling formalism for the ac conductivity in disordered systems. The characteristic frequency f(c) at which Σ(x,f) or Σ(T,f) increases for the first time from Σ(0) scales with initial conductance Σ(0) as f(c) ~ Σ(0)(x(f)), where x(f) is the onset exponent. The value of x(f) is nearly equal to one and is found to be independent of x and T. Further, an inverse relationship between x(f) and s provides a self-consistency check of the systematic description of Σ(x,f) or Σ(T,f). This apparent universal value of x(f) is discussed within the framework of existing theoretical models and scaling theories. The relevance to other similar disordered systems is also highlighted.

A new unstable hemoglobin variant Hb Acharnes or [β53(D4) Ala - Thr]: a case report

Hb Acharnes or [β53(D4) Ala - Thr] is a newly discovered unstable hemoglobin variant. It has been reported in very few literatures across the world and no cases have been reported from India till date. Hb Acharnes is known to interact with β°-thalassemia to produce thalassemia intermedia and heterozygotes may present with borderline HbA2 levels. Here we report a rare case discovered during routine screening of thalassemia and hemoglobinopathies in a 19 year old pregnant lady. To emphasize the diagnostic difficulties and importance of detection of a rare hemoglobin variant Hb Acharnes [β53(D4) Ala - Thr] in an asymptomatic patient in West Bengal, India. The 19 year old asymptomatic pregnant lady P1+0, LMP - 21.01.2011 reported in antenatal OPD of Burdwan Medical College & Hospital, Burdwan, West Bengal, India for routine follow up. After proper antenatal check up her blood was collected as a routine screening for Thalassemia, EDTA blood was taken on 5th April 2011 and was subjected to Hemoglobin estimation by Cyanmethemoglobin method, Cell parameters in automated cell counter (SYSMEX KX21) and Hemoglobin analysis by HPLC in BIORAD VARIANT system. The patient was normal with respect to clinical examination and urinalysis. Routine blood counts revealed mild microcytic hypochromic anemia and on HPLC an unknown band (retention time 2.2 minutes, 21.2%, appearing as a shoulder of HbA0 band) of hemoglobin variant was discovered with normal level of HbF and HbA2. Hemoglobin analysis of her mother showed similar pattern while her father and her husband had normal Hb-HPLC pattern. The unknown hemoglobin variant was identified as Hemoglobin Acharnes or [β53 (D4) Ala - Thr] by the Biorad laboratories upon consulting the standard chromatogram patterns for this particular hemoglobin variant. Only Haemoglobin Electrophoresis by conventional gel technique may miss the case and the HPLC pattern may be used as a standard control for identification.

Observation of Griffiths phase in antiferromagnetic La(0.32)Eu(0.68)MnO3

We report the Griffiths phase (GP) scenario for isovalent doping in antiferromagnetic La(0.32)Eu(0.68)MnO(3). Rietveld refinement of structural data displays strong crystal structural distortion. The dc and ac magnetic studies nicely demonstrate unambiguous aspects of robust GP. The presence of ferromagnetically correlated spin clusters is found above the transition temperature, T(N). The disorder-driven phase inhomogeneity is correlated to strong structural distortion, giving rise to the GP. This is an unique example in manganite where double exchange interaction does not play any role for the observed phenomenon.

Tuning A-site ionic size in R(0.5)Ca(0.5)MnO3 (R = Pr, Nd and Sm): robust modulation in dc and ac transport behavior

Structural investigations on Pr(0.5)Ca(0.5)MnO(3), Nd(0.5)Ca(0.5)MnO(3) and Sm(0.5)Ca(0.5)MnO(3) display a systematic tuning in orthorhombic distortion which appears due to a change in A-site ionic size. Comprehensive investigations on dc conduction using various models indicate strong correlation with structural changes. Careful analysis of the ac conductivity mechanism as a function of frequency and temperature brings out a pronounced effect of structural modifications on the polaron conduction mechanism. Contrary to typical manifestations, dc conductivity and relaxation of charge carriers reveal non-Arrhenius behavior. This work provides a detailed and systematic addition to the phase diagram of electronic transport in the rare-earth manganite system doped with a divalent alkali atom.

Charge carrier dynamics and relaxation in (polyethylene oxide-lithium-salt)-based polymer electrolyte containing 1-butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide as ionic liquid

In this paper we report the dynamics of charge carriers and relaxation in polymer electrolytes based on polyethylene oxide (PEO), lithium bis(trifluoromethylsulfonyl)imide (LiTFSI) and 1-butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide (BMPTFSI) ionic liquid prepared by solution cast technique. It has been observed that the incorporation of BMPTFSI into PEO-LiTFSI electrolyte is an effective way for increasing the amorphous phase to a large extent. It has also been observed that both the glass transition and melting temperatures decrease with the increase of BMPTFSI concentration. The ionic conductivity of these polymer electrolytes increases with the increase of BMPTFSI concentration. The highest ionic conductivity obtained at 25 °C is ~3×10(-4) S cm(-1) for the electrolyte containing 60 wt % BMPTFSI and ethylene oxide (EO)/Li ratio of 20. The temperature dependence of the dc conductivity and the hopping frequency show Vogel-Tamman-Fulcher type behavior indicating a strong coupling between the ionic and the polymer chain segmental motions. The frequency dependence of the ac conductivity exhibits a power law with an exponent n which decreases with the increase of temperature. The scaling of the ac conductivity indicates that relaxation dynamics of charge carriers follows a common mechanism for all temperatures and BMPTFSI concentrations. We have also presented the electric modulus data which have been analyzed in the framework of a Havriliak-Negami equation and the shape parameters obtained by the analysis show slight temperature dependence, but change sharply with BMPTFSI concentration. The stretched exponent β obtained from Kohlrausch-Williams-Watts fit to the modulus data is much lower than unity signifying that the relaxation is highly nonexponential. The decay function obtained from analysis of experimental modulus data is highly asymmetric with time.

Structural and magnetic properties of spontaneously phase-separated Eu0.5Sm0.5MnO3

We have studied structural and magnetic properties of Eu(0.5)Sm(0.5)MnO(3). The system shows strong orthorhombic distortion. The static Jahn-Teller effect modifies the low temperature magnetic properties, creating a complicated anisotropic magnetic ground state. A low temperature magnetic phase separation has also been realized that builds magnetic interfaces exhibiting strong exchange bias. Careful analysis of the magnetic behaviour indicates the origin of the exchange bias to be a phase separation between an A-type antiferromagnetic phase and a low temperature highly anisotropic phase originating from another ordering at the rare-earth sublattice.

Radiation-pressure acceleration of ion beams from nanofoil targets: the leaky light-sail regime

A new ion radiation-pressure acceleration regime, the "leaky light sail," is proposed which uses sub-skin-depth nanometer foils irradiated by circularly polarized laser pulses. In the regime, the foil is partially transparent, continuously leaking electrons out along with the transmitted laser field. This feature can be exploited by a multispecies nanofoil configuration to stabilize the acceleration of the light ion component, supplementing the latter with an excess of electrons leaked from those associated with the heavy ions to avoid Coulomb explosion. It is shown by 2D particle-in-cell simulations that a monoenergetic proton beam with energy 18 MeV is produced by circularly polarized lasers at intensities of just 10¹⁹  W/cm². 100 MeV proton beams are obtained by increasing the intensities to 2 × 10²⁰  W/cm².

Characterization of two distinct, simultaneous hot electron beams in intense laser-solid interactions

The transport of energetic electron beams generated from aluminum foils irradiated by ultraintense laser pulses has been studied by imaging coherent transition radiation from the rear side of the target. Two distinct beams of MeV electrons are emitted from the target rear side at the same time. This measurement indicates that two different mechanisms, namely resonance absorption and jxB heating, accelerate the electrons at the targets front side and drive them to different directions, with different temperatures. This interpretation is consistent with 3D-particle-in-cell simulations.

Directed acceleration of electrons from a solid surface by Sub-10-fs laser pulses

Electrons have been accelerated from solid target surfaces by sub-10-fs laser pulses of 120 microJ energy which were focused to an intensity of 2x10;{16} W/cm;{2}. The electrons have a narrow angular distribution, and their observed energies exceed 150 keV. We show that these energies are not to be attributed to collective plasma effects but are mainly gained directly via repeated acceleration in the transient field pattern created by incident and reflected laser, alternating with phase-shift-generating scattering events in the solid.

Screening for Barrett's esophagus by balloon cytology

OBJECTIVE

to determine whether balloon cytology would allow a nonendoscopic diagnosis of Barrett's esophagus.

METHODS

In 10 unselected patients with Barrett's esophagus, balloon cytology was performed with a Brandt esophageal cytology balloon catheter prior to endoscopy/esophageal biopsy. Specimens were cytologically evaluated for the presence of goblet cells and/or dysplasia.

RESULTS

No patient had goblet cells or definitive columnar cell dysplasia.

CONCLUSION

This technique with a commercially available balloon catheter does not allow for a nonendoscopic diagnosis of Barrett's esophagus.

Mutations of p53 and human papillomavirus infection in cervical carcinoma

BACKGROUND

Oncogenic human papillomavirus (HPV) infection has been implicated in the pathogenesis of cervical carcinoma. The HPV oncoproteins E6 and E7 are though to play a crucial role in this process by their interactions with the p53 protein and the retinoblastoma susceptibility gene product, respectively. The E6 protein binds to and stimulates the degradation of the p53 protein. Mutations involving evolutionary conserved regions of the p53 gene also can alter p53 function. Point mutations of p53 frequently have been identified in a wide variety of human tumors.

METHODS

Forty-five cervical carcinoma samples were evaluated for the presence of mutations involving exons 5-8 of the p53 gene with polymerase chain reaction (PCR) amplification of genomic DNA, followed by single-stranded conformation polymorphism analysis and/or direct sequencing. The status of oncogenic HPV infection in the tumor tissues was analyzed by Southern blot and PCR.

RESULTS

Forty-two of 45 cervical carcinomas showed oncogenic HPV DNA: Of three HPV-negative samples, one harbored a missense point mutation of the p53 gene. An additional p53 point mutations was identified in a tumor with HPV 18 infection.

CONCLUSIONS

Oncogenic HPV DNA can be identified in most cervical carcinomas. Mutations involving conserved regions of p53, although infrequent in cervical cancer, occur preferentially in tumors without HPV infection. Inactivation of p53 function is important in the pathogenesis of cervical carcinoma.

Regulation of manganese superoxide dismutase and other antioxidant genes in normal and leukemic hematopoietic cells and their relationship to cytotoxicity by tumor necrosis factor

Myeloid cells are a major source of superoxide and other oxygen metabolites. As a protective mechanism, cells express antioxidant enzymes including manganese superoxide dismutase (Mn-SOD), copper-zinc SOD (Cu/Zn-SOD), and glutathione peroxidase (GSX-PX). Even though hematopoietic cells are a major source of oxidants, little is known of their expression of antioxidants. We found that seven myeloid leukemic cell lines blocked at different stages of differentiation constitutively expressed Mn-SOD, Cu/Zn-SOD, and GSX-PX RNAs. Level of Mn-SOD activities paralleled levels of Mn-SOD RNA. Terminal differentiation of native HL-60 cells to either granulocytes or macrophages did not alter levels of Mn-SOD RNA but markedly decreased cell division. Myeloid leukemic lines sensitive to cytotoxic effects of tumor necrosis factor (TNF) as well as normal peripheral blood lymphocytes and monocytes, dramatically increased their levels of Mn-SOD RNA in the presence of TNF. In contrast, Cu/Zn-SOD and GSX-PX RNA levels did not increase in these same cells. TNF-resistant leukemic lines had higher constitutive levels of Mn-SOD RNA and activity; and these levels did not change in the presence of TNF. Antisense but not random oligonucleotides to Mn-SOD markedly increased the sensitivity to the inhibitory effects of TNF for both the native HL-60 (TNF-sensitive) and K562 (TNF-resistant) cell lines. Further studies showed that the antisense oligonucleotides entered the cells and resulted in decreased levels of Mn-SOD RNA. The data suggest that Mn-SOD may provide protection against cytotoxicity of TNF in hematopoietic cells.

Mutations of p53 and human papillomavirus infection in cervical carcinoma

BACKGROUND

Oncogenic human papillomavirus (HPV) infection has been implicated in the pathogenesis of cervical carcinoma. The HPV oncoproteins E6 and E7 are though to play a crucial role in this process by their interactions with the p53 protein and the retinoblastoma susceptibility gene product, respectively. The E6 protein binds to and stimulates the degradation of the p53 protein. Mutations involving evolutionary conserved regions of the p53 gene also can alter p53 function. Point mutations of p53 frequently have been identified in a wide variety of human tumors.

METHODS

Forty-five cervical carcinoma samples were evaluated for the presence of mutations involving exons 5-8 of the p53 gene with polymerase chain reaction (PCR) amplification of genomic DNA, followed by single-stranded conformation polymorphism analysis and/or direct sequencing. The status of oncogenic HPV infection in the tumor tissues was analyzed by Southern blot and PCR.

RESULTS

Forty-two of 45 cervical carcinomas showed oncogenic HPV DNA: Of three HPV-negative samples, one harbored a missense point mutation of the p53 gene. An additional p53 point mutations was identified in a tumor with HPV 18 infection.

CONCLUSIONS

Oncogenic HPV DNA can be identified in most cervical carcinomas. Mutations involving conserved regions of p53, although infrequent in cervical cancer, occur preferentially in tumors without HPV infection. Inactivation of p53 function is important in the pathogenesis of cervical carcinoma.

High prevalence of mutations of the p53 gene in poorly differentiated human thyroid carcinomas

The development and progression of thyroid tumors is signaled by phenotype-specific mutations of genes involved in growth control. Molecular events associated with undifferentiated thyroid cancer are not known. We examined normal, benign, and malignant thyroid tissue for structural abnormalities of the p53 tumor suppressor gene. Mutations were detected by single-strand conformation polymorphisms of PCR-amplified DNA, using primers bracketing the known hot spots on either exons 5, 6, 7, or 8. The prevalence of mutations was as follows: normal thyroid 0/6; follicular adenomas 0/31; papillary carcinomas 0/37; medullary carcinomas 0/2; follicular carcinomas 1/11; anaplastic carcinomas 5/6; thyroid carcinoma cell lines 3/4. Positive cases were confirmed by direct sequencing of the PCR products. All five anaplastic carcinoma tissues and the anaplastic carcinoma cell line ARO had G:C to A:T transitions leading to an Arg to His substitution at codon 273. In both tumors and cell lines, examples of heterozygous and homozygous p53 mutations were identified. The only thyroid carcinoma cell line in which p53 mutations were not detected in exons 5-8 had markedly decreased p53 mRNA levels, suggesting the presence of a structural abnormality of either p53 itself or of some factor controlling its expression. The presence of p53 mutations almost exclusively in poorly differentiated thyroid tumors and thyroid cancer cell lines suggests that inactivation of p53 may confer these neoplasms with aggressive properties, and further loss of differentiated function.

1,25-Dihydroxyvitamin D3 receptor RNA: expression in hematopoietic cells

1,25-Dihydroxyvitamin D3 [1,25(OH)2D3] induces differentiation and inhibits proliferation of myeloid leukemic cells from various lines and patients; these effects are probably mediated through the 1,25(OH)2D3 receptor. Little is known of expression of 1,25(OH)2D3 receptor RNA in hematopoietic cells. We examined the expression and modulation of expression of 1,25(OH)2D3 receptor RNA in various proliferating and nonproliferating hematopoietic cells. Constitutive expression of 1,25(OH)2D3 receptor RNA was detected in various kinds of hematopoietic cells, including macrophages and activated T lymphocytes, as well as in cell lines KG-1 (myeloblasts), HL-60 (promyelocytes), ML-3 (myelomonoblasts), U937, THP-1 (monoblasts), K562 (erythroblasts), and S-LB1 (HTLV-1-transfected T lymphocytes). Receptor transcripts were 4.6 kilobases (kb), and no variant sizes were observed. All cell lines examined in this group also expressed 1,25(OH)2D3 receptors. Most B lymphocyte lines expressed negligible levels of 1,25(OH)2D3 receptor RNA and protein; however; analysis of a lymphoid/myeloid somatic hybrid suggested that suppression of expression of 1,25(OH)2D3 receptor RNA in B lymphocytes may be a dominant characteristic. HL-60 cells were cultured with 10(-7) mol/L 1,25(OH)2D3 for 24 to 72 hours, and levels of expression of 1,25(OH)2D3 receptor and its RNA were examined. Levels of RNA coding for the receptor were not modulated by exposure to high levels of ligand. Levels of occupied 1,25(OH)2D3 receptor protein increased in these HL-60 cells; but the total number of 1,25(OH)2D3 receptors decreased about 50% at 24 hours and returned toward normal at 72 hours. Steady-state levels of 1,25(OH)2D3 receptor RNA were not affected by terminal differentiation of HL-60 toward either granulocytes or macrophages. Nondividing macrophages from normal individuals also expressed 1,25(OH)2D3 receptor RNA. In contrast, nondividing peripheral blood lymphocytes from normal individuals did not express 1,25(OH)2D3 receptor RNA; with stimulation of proliferation of these cells, accumulation of 1,25(OH)2D3 receptor RNA increased markedly. Half-life (t1/2) of 1,25(OH)2D3 receptor RNA in T lymphocytes was short (1 hour) as determined by measuring decay of the message after addition of actinomycin D. Consistent with this short t1/2, accumulation of 1,25(OH)2D3 receptor RNA increased in cells as their protein synthesis was inhibited. Further studies are required to understand the physiologic role of 1,25(OH)2D3 receptors in myeloid cells and proliferating T lymphocytes.

Bilateral tubercular abscess of breast in axillary tail in a 21 year old puerperal lady

Tuberculosis is a very common disease in the Indian subcontinent. Though it can affect any system of the body, primary involvement of the breast is relatively rare even in India. Involvement of the axillary tail is even rarer. Bilateral involvement is also a rare phenomenon (3%). Moreover the disease is often overlooked and misdiagnosed as carcinoma or pyogenic abscess. Here we report a case of bilateral tubercular abscess of breast in the axillary tail in a 21 year old puerperal lady diagnosed by FNAC and AFB stains and further confirmed retrospectively by response to anti-tubercular drugs. Keywords: Tuberculosis; Breast. DOI: 10.3329/bjms.v10i1.7323 Bangladesh Journal of Medical Science Vol.10 No.1 Jan 2010 pp.60-63