Lecithin organogels as a potential phospholipid-structured system for topical drug delivery: A review

The purpose of this review is to give an insight into the considerable potential of lecithin organogels (LOs) in the applications meant for topical drug delivery. LOs are clear, thermodynamically stable, viscoelastic, and biocompatible jelly-like phases, chiefly composed of hydrated phospholipids and appropriate organic liquid. These systems are currently of interest to the pharmaceutical scientist because of their structural and functional benefits. Several therapeutic agents have been formulated as LOs for their facilitated transport through topical route (for dermal or transdermal effect), with some very encouraging results. The improved topical drug delivery has mainly been attributed to the biphasic drug solubility, the desired drug partitioning, and the modification of skin barrier function by the organogel components. Being thermodynamically stable, LOs are prepared by spontaneous emulsification and therefore posses prolonged shelf life. The utility of this novel matrix as a topical vehicle has further increased owing to its very low skin irritancy potential. Varied aspects of LOs viz formation, composition, phase behavior, and characterization have been elaborated, including a general discussion on the developmental background. Besides a comprehensive update on the topical applications of lecithin organogels, the review also includes a detailed account on the mechanistics of organogelling. Published: October 6, 2005     

Precise blood lead analysis using a combined internal standard and standard addition approach with disposable screen-printed electrodes

We report here a highly accurate and efficient method for blood lead analysis (BLA) through the use of a disposable electrode. A new type of mercury-plated preanodized screen-printed carbon electrode, together with a thallium(III) internal standard, simplifies calibration and gives easily quantifiable signals for accurate BLA. A preanodization procedure improves the preconcentration ability of the working electrode through the effect of lead (Pb) complexing with an electrogenerated surface functional group, mainly >C=O. Under optimized conditions, the ratio of the anodic stripping peak currents of Pb and Tl (i.e., i(Pb)/i(Tl)) is linear against [Pb] in the window of 1-300 ppb with a correlation coefficient and detection limit (signal-to-noise ratio=3) of 0.999 and 0.23 ppb, respectively. This approach was used to analyze blood samples (n=55) from workers at a local battery factory. The results are consistent with those obtained from graphite furnace atomic absorption spectroscopy and confirm the applicability of the proposed method.     

Diagnostic considerations in prolymphocytes in pleural fluid: a case report

BACKGROUND: Prolymphocytes are nucleolated cells that are the defining features of the 2 chronic lymphoproliferative disorders, prolymphocytic leukemia (PLL) and chronic lymphocytic leukemia (CLL) with increased prolymphocytes. Prolymphocytes appear relatively unfamiliar in cytopathology practice, and, particularly when present in body fluids, may resemble blasts or adult T-cell leukemia/ lymphoma (ATLL) cells. CASE: A 32-year-old man, referred to us with a diagnosis of acute leukemia, presented with shortness of breath for 2 months and loss of appetite for 3 months. He had enlarged liver and spleen, 6 and 8 cm, respectively, below the costal margin and pleural effusion. The raised total leukocyte count chiefly comprised prolymphocytes that, especially in the pleural fluid, had prominent nucleoli and significant pleomorphism, raising the possibility of blasts or ATLL. CONCLUSION: Prolymphocytes in body fluids can be misinterpreted as blasts or even ATLL cells. Better awareness among cytopathologists about prolymphocytes and the disease states in which they occur, as well as insistence, in a clinical setting of leukemia, on interpreting the pleural fluid in relation to the clinical and laboratory findings, especially those of the peripheral blood and bone marrow, can prevent misdiagnosis. Equally importantly, immunophenotyping must be done in such situations.     

Synthesis and biological activity of fluoroquinolone-pyrrolo[2,1-c][1,4]benzodiazepine conjugates

Fluoroquinolones have been synthesized and linked to DC-81 at C8 position through different alkyl chain spacers. These PBD conjugates have exhibited good DNA binding affinity, and a representative compound shows promising in vitro anticancer activity.     

Synthetic studies of cis-4-Amino-L-proline derivatives as novel lipid lowering agents

cis-4-Amino-L-proline derivatives 1 and 2 derived from quinazolinone and pyrazolo pyrimidone respectively were designed as novel lipid lowering agents. A preliminary in vivo screening indicates that 1b and 2a have moderate triglyceride lowering activity.     

Improved multiple displacement amplification with phi29 DNA polymerase for genotyping of single human cells

The ability to genotype multiple loci of single cells would be of significant benefit to investigations of cellular processes such as oncogenesis, meiosis, fertilization, and embryogenesis. We report a simple two-step, single-tube protocol for whole-genome amplification (WGA) from single human cells using components of the GenomiPhi V2 DNA Amplification kit. For the first time, we demonstrate reliable generation of 4-7 microg amplified DNA from a single human cell within 4 h with a minimum amount of artifactual DNA synthesis. DNA amplified from single cells was genotyped for 13 heterozygous short tandem repeats (STRs) and 7 heterozygous single nucleotide polymorphisms (SNPs), and the genotyping results were compared with purified genomic DNA. Accuracy of genotyping (percent of single-cell amplifications genotyped accurately for any particular STR or SNP) varied from 37% to 100% (with an average of 80%) for STRs and from 89% to 100% (averaging 94%) for SNPs. We suggest that the method described in this report is suitable for WGA from single cells, the product of which can be subsequently used for many applications, such as preimplantation genetic analysis (PGD).     

Molecular cloning,characterization and expression of a nitrofuran reductase gene ofescherichia coli

Mini-mu derivatives carrying plasmid replicons can be used to clone genesin vivo. This method was adopted to generate phasmid clones which were later screened for their ability of restore nitrofurantoin sensitivity of a nitrofuran-resistant host by eliciting nitroreductase activity. One phasmid-derived clone (pAJ101) resulted in considerable increase in nitroreductase activity when introduced into a nitrofurantoin-resistant mutant ofEscherichia coli with reduced nitroreductase activity. Subsequently, a 1.8 kb fragment obtained from pAJ101 by partial digestion with 5au3A, was subcloned into pUC18 to yield pAJ102. The nitroreductase activity attributable to pAJ102 was capable of reducing both nitrofurantoin and nitrofurazone. The polypeptides encoded by pAJ102 were identified by the minicell method. A large, well-defined band corresponding to 37 kDa and a smaller, less-defined band corresponding to 35 kDa were detected. Tnl000 mutagenesis was used to delineate the coding segment of the 1.8 kb insert of pAJ102. A 0.8 kb stretch of DNA was shown to be part of the nitroreductase gene. The gene was mapped at 19 min on theEscherichia coli linkage map.     

A report on <Emphasis Type="Italic">Penicillium</Emphasis> in the intramural and extramural air of residential areas of Nagpur city (India)

Prevalence of different species of Penicillium and their concentrations per cubic meter of air were evaluated with the use of Hi-Air sampler system Mark II (Hi-Media Laboratories Ltd., India) in the air of homes (bed-rooms) at four different sites in Nagpur. At each of these sites, air sampling was done fortnightly in triplicate for 2 years duration from June 2000 to May 2002. The sampling was also done in triplicate for the outdoor air in the vicinity of each home on the same day immediately after the indoor sampling was over. The mean concentration of Penicillium colony forming units at four different sites in the indoor air was 32, 46.9, 35 and 35.4 CFU/m³, respectively, whereas in the outdoor air at these same four sites, the mean concentration was 24, 28, 25 and 25.8 CFU/m³ respectively. The Penicillium concentration in the indoor air was found to be higher in winter than in other seasons (ANOVA, p < 0.05). Concentration of Penicillium spp. in intramural environment was always higher than that in extramural environment. Statistically significant difference existed between intramural and extramural environments at all the sites, with maximum difference at a site, which is old crowded area of the city. During the 2-years investigations, 11 species of Penicillium were isolated from the indoor air while nine species were isolated from the air outside the homes. The dominant species of Penicillium in indoor as well as outdoor air were P. citrinum (33.78 and 32.81), P. oxalicum (19.70 and 22.60), and P. chrysogenum (17.64 and 14.50). The percentage of the Penicillium in the indoor air was 10.70 while it was 8.36 in outdoor air. Indoor air showed the presence of P. glaber and P. sclerotiorum, which were absent in the outdoor air.