Nanostructure formation in aqueous solution of amphiphilic copolymers of 2-(N,N-dimethylaminoethyl)methacrylate and alkylacrylate: Characterization, antimicrobial activity, DNA binding, and cytotoxicity studies

Three amphiphilic random copolymers poly(2-(dimethylaminoethyl)methacrylate-co-alkylacrylate) (where, alkyl = hexyl, octyl, dodecyl) with 16 mol% hydrophobic substitution were synthesized. Surface tension, viscosity, fluorescence probe, dynamic light scattering (DLS), as well as transmission electron microscopic (TEM) techniques were utilized to investigate self-assembly formation by the hydrophobically modified polymers (HMPs) in pH 5. Formation of hydrophobic domains through inter-polymer chain interaction of the copolymer in dilute solution was confirmed by fluorescence probe studies. Average hydrodynamic diameter of the copolymer aggregates at different polymer concentration was measured by DLS studies. The copolymer with shorter hydrophobic chain exhibits larger hydrodynamic diameter in dilute solution, which decreased with either increase of concentration or increase of hydrophobic chain length. TEM images of the dilute solutions of the copolymers with shorter as well as with longer hydrophobic chain exhibit spherical aggregates of different sizes. The antimicrobial activity of the copolymers was evaluated by measuring the minimum inhibitory concentration value against one Gram-positive bacterium Bacillus subtilis and one Gram-negative bacterium Escherichia coli. The copolymer with the octyl group as pendent hydrophobic chain was found to be more effective in killing these microorganisms. The interaction of the cationic copolymers with calf-thymus DNA was studied by fluorescence quenching method. The polymer-DNA binding was found to be purely electrostatic in nature. The hydrophobes on the polymer backbone were found to have a significant influence on the binding process. Biocompatibility studies of the copolymers in terms of cytotoxicity measurements were finally performed at different concentrations of the HMPs to evaluate their potential application in biomedical fields.     

Prevalence and Role of Candida in Acute Gastroenteritis (Choleraic and non-choleraic)

Candida species were isolated and identified from the stool samples of cholera and non-dioleraic acute gastroenteritis (GE) cases. From 500 samples (398 from GE and 102 from cholera cases) 129 strains of Candida were isolated. The total rate percentage of Candida in both the groups varied from 25–26 %.
The incidence of Candida in GE was higher in children from 1–4 years whereas in cholera cases the incidence was higher in the group from 5–9 years.
On statistical analysis it was found that the association of C. albicans and C. tropicalis with gastroenteritis, either choleraic or non-choleraic, bears no significance to the disorder. Complete dissociation of the species of C. albicans and C. tropicalis was found in the stool samples of the two groups of gastroenteritis cases.

Zusammenfassung

Candida -Arten — 129 Stämme — wurden aus Stuhlproben von Patienten, die an Cholera (102 Fälle) oder an einer akuten Gastroenteritis (398 Fälle) erkrankt waren, isoliert und identifiziert. Bei beiden Patientengruppen lag der Prozentsatz des Candida -Nachweises zwischen 25 bis 26 %. Das Sproßpilzvorkommen lag bei 1–4 Jahre alten Kindern nit einer Gastroenteritis höher. Bei der Vergleichsgruppe der Cholera-Kranken waren vermehrt Sproßpilze bei 5–9 Jahre alten Kindern nachzuweisen.
Statistische Berechnungen zeigten keine Verbindung zwischen Candida albicans - und Candida tropicalis -Nachweis zu den Cholera- oder nicht Cholera-bedingten Gastro-enteritiden. Die beiden Candida -Arten wurden in keinem Fall gemeinsam aus einer der Stuhlproben gezüchtet.     

X-linked Ichthyosis Presenting as Erythroderma: A Rare Case

X-linked ichthyosis is a rare form of dermatological disease and when it presents as erythroderma it is even rarer. History of consanguineous marriage and prolonged labor during birth of patient, generalized scaling which gets better in summer months, flexural involvement, cryptorchidism made a diagnosis of X-linked ichthyosis. We report this case because of its rarity as erythroderma.     

CoMFA, CoMSIA, and docking studies on thiolactone-class of potent anti-malarials: identification of essential structural features modulating anti-malarial activity

The integrated ligand‐ and structure‐based drug design techniques have been applied on a homogeneous dataset of thiolactone‐class of potent anti‐malarials, to explore the essential structural features for the inhibition of Plasmodium falciparum. Developed CoMFA (q² = 0.716) and CoMSIA (q² = 0.632) models well explained structure–activity variation in both the training (CoMFA R² = 0.948 & CoMSIA R² = 0.849) and test set (CoMFA R²_pred = 0.789 & CoMSIA R²_pred = 0.733) compounds. The docking and scoring of the most active compound 10 into the active site of high‐resolution (2.35 Å) structure of FabB‐TLM binary complex (PDB‐ID: 1FJ4) indicated that thiolactone core of this compound forms bifurcated H‐bonding with two catalytic residues His298 and His333, and its saturated decyl side group is stabilized by hydrophobic interactions with the residues of a small hydrophobic groove, illustrating that the active site architecture, including two catalytic histidines and a small hydrophobic groove, is vital for protein–ligand interaction. In particular, the length and flexibility of the side group attached to the position 5 of thiolactone have been observed to play a significant role in the interaction with FabB enzyme. These results present scope for rational design of thiolactone‐class of compounds that could furnish improved anti‐malarial activity.     

Perianal verrucous epidermal nevus masquerading as warts

Verrucous epidermal naevus(VEN) is a rare form of epidermal naevus. We present a case of VEN occurring over the perianal region of a 7-year-old boy. The lesion was initially thought to be an area of chronic dermatitis; however it was refractory to treatment. Histopathology confirmed the diagnosis of VEN. VEN in the inguinogenital region may be misdiagnosed as flexural psoriasis, genital warts or sexual abuse. This is what precisely happened to our patient for a duration of more than 1 year.