Multifunctional soft hybrid bio-platforms based on nano-silver and natural compounds.

Novel nanohybrids consisting of nano-Ag, chitosan, lipids and phyto-compounds (chlorophyll a and curcumin) have been achieved through a simple bottom-up strategy, resulting in stable (ZP=-30.9mV) and spherical-shaped nano-entities with size <200nm (estimated by AFM analysis and DLS measurements). The formation of these biohybrids was monitored by absorption and emission spectroscopy, exploiting the spectral fingerprint of chlorophyll a. The bio-performances of these hybrid materials such as: high antioxidant activity (96.63%), strong biocidal properties against Escherichia coli ATCC 8738 (exhibiting an inhibition zone diameter of 32mm), hemocompatibility, in vitro cytotoxicity against HT-29 cancer cells and no toxicity to normal cells (in the biohybrid concentration range of 5.7-17%), make them promising candidates in bio-applications (antimicrobial and antioxidant coating, cancer treatment).

The human follitropin alpha-subunit C terminus collaborates with a beta-subunit cystine noose and an alpha-subunit loop to assemble a receptor-binding domain competent for signal transduction.

FSH is a member of the pituitary/placental glycoprotein hormone family including luteinizing hormone, thyroid-stimulating hormone, and chorionic gonadotropin. These heterodimeric hormones share a common alpha-subunit and a highly homologous but distinct beta-subunit. The determinant loop of the FSH beta-subunit acts both as a specificity discriminator and as an essential receptor-binding site. The three-dimensional structure of hCG illustrates the proximity of the determinant loop to the carboxyl-terminal residues of the common alpha-subunit. Thus, site-directed mutagenesis was used to mak high-resolution substitutions at this carboxyl-terminal locus. The effects of those substitutions were studied. Twelve single mutations and one composite mutation were made of the region of hFSH alpha 74-92, each residue substituted by alanine. Side chain replacement in this region of FSH proved to be detrimental to binding. hFSH with mutations of either alpha S85A, alpha T86A, alpha K91A, or alpha S92A only retained 10% or less of the hFSH receptor-binding activity, while compared to these, mutants alpha H79A, alpha Y88A, and alpha Y89A retained slightly more binding activity. The single mutant alpha F74A and composite mutant alpha V76A/E77A binding activity was reduced to half of that of wild-type (WT) hFSH. In contrast, mutations of either alpha K75A, alpha T80A, alpha H83A, or alpha H90A did not adversely affect receptor binding, demonstrating the specificity of observed effects. The hFSH and mutant hormones were tested in an in vitro bioassay for stimulation of progesterone production. Those mutations that did not affect receptor binding (alpha K75A, alpha T80A, alpha H83A, and alpha H90A) did not affect signal transduction, measured by progesterone responses. After comparison of wild-type and mutant hFSH activities determined in radioreceptor assays (ID50) and in vitro bioassays (ED50), it became evident that signal transduction correlated with receptor binding.

Diabetic gangrene: medical and surgical causes and consequences.

Diabetic gangrene is the chronic complication which involves many medical, economic and social problems. In this study we have analyzed the medical and surgical causes and consequences of diabetic gangrene on three groups of patients: 120 patients (96 males and 24 females; aged (X +/- SD) 57 +/- 14 years hospitalised in the Clinic of Diabetes, Nutrition and Metabolic Diseases of the "N. Paulescu" Institute, 72 patients (59 males and 13 females; mean age 60 +/- 10 years) hospitalised in the Surgical Clinic of Cantacuzino Hospital; 29 patients (23 males and 6 females; mean age 58 +/- 11 years) hospitalised in the Cardiovascular Department of Fundeni Hospital. The analyses of data obtained showed: in 77% of cases the initial lesions might have been avoided by an appropriate education programme of the patients; in 66% of cases the progression of lesion from medical to surgical stage was caused by tardily coming of patient to physician; average duration of hospitalization was 27 days in the Clinic of Diabetes, Nutrition and Metabolic Diseases, 33 days in the Clinic of Surgery of "Cantacuzino" Hospital and 25 days in Cardiovascular Department of Fundeni Hospital; the surgical mortality was 8%; 47% operated patients were cured and 53% were incompletely cured and required more out patient care; 35% were thigh amputations, that shows the high invalidity potential of diabetic gangrene; the cost of medical and/or surgical care of diabetic gangrene is higher than the cost of hospitalisation for other patients; the diabetic gangrene predominantly neuropathic was better cured and the arteriopathic component breaks the medical curing and impose high amputations; diabetic gangrene is more frequent with older people, but with young people it is a cause of early retiring and psycho-social concern.

[Sensitivity in vitro of some bacterial strains to procaine]. / Sensibilitatea in vitro a unor tulpini bacteriene fata de procaina.

The action range of procaine, this multipotent substance, may also be extended to the domain of bacteriology due to its bacteriostatic, bactericide, fungistatic and fungicide properties. The antibacterial activity of Höechst procaine hydrochlorate powder was determined on 15 bacterial strains and 2 Candida strains isolated from various human infections. The in vitro antibacterial effect of the powder was demonstrated by the diffusimetric and the dilution methods, determining the minimal inhibitory concentration and minimal bactericide concentration. Procaine had a high antibacterial activity against Streptococcus B hemolyticus gr. A and viridans, and against certain enterobacteria (E. coli Proteus). THe results show the possibility of using procaine also in the local treatment of infections caused by these agents.

[Karyotype of Nicotiana tabacum L. artificial haploids]. / Contribution à l'étude caryologique d'haploïdes artificiels du Nicotiana tabacum L

Twenty-five platelets obtained by culturing anthers of Nicotiana tabacum L. var. "Wisconsin 38" are haploids (22) or mixoploids (3). Numerous aneuhaploid cells were observed in 15 haploid plants (n = 18, 20, 22, 23, 25, 26, 28). Such a chromosomic variability careful caryological studies of haploid plants before these are used in genetic work.