Cell cycle perturbating agents in a line of human thyroid transformed cells in culture (HuT)

Culture and differentiation parameters of a human thyroid transformed cell line (HuT) were analyzed. Treatment with high concentrations of chemical agents namely dimethyl sulphoxide and retinoic acid, exerted a dramatic cytotoxic effect. The exposure of these cells to the lowest doses of retinoic acid as well as to 8 mM–16 mM 3-aminobenzamide a potent inhibitor of poly(ADPribose)polymerase, resulted in a delay of cell proliferation. Poly(ADPribose)polymerase activity was differently affected by retinoic acid (stimulation) and 3-aminobenzamide (inhibition).     

Host genetic background effect on the frequency of mouse mammary tumor virus-induced rearrangements of the int-1 and int-2 loci in mouse mammary tumors.

The frequency with which int-1 and int-2 are rearranged in mouse mammary tumors by mouse mammary tumor virus (MMTV)-induced insertional mutagenesis is a consequence of the host genetic background. In 75% of C3H mammary tumors, int-1 is rearranged by MMTV insertion, whereas only 30% of BALB/cfC3H tumors contain a virus-induced rearrangement of int-1. This difference is significant (P less than 0.005) and could not be accounted for by the potentially additive effect of the genetically transmitted Mtv-1-encoded virus in C3H mice. Similarly, MMTV-induced rearrangement of the int-2 gene in mammary tumors of the R111 mouse strain (59%) occurred at a significantly (P less than 0.025) higher frequency than in BALB/cfR111 (25%) mammary tumors. Moreover, in BALB/cfR111 mammary tumors, there is evidence that rearrangement of int-1 and int-2 does not occur independently (P less than 0.025). These results suggest that the long history of inbreeding for high tumor incidence of C3H and R111 mouse strains has selected for the fixation of host mutations which either complement the action of the particular int gene or affect the sensitivity of specific subpopulations of mammary epithelium to infection by particular strains of MMTV.     

Antifungal activity of ovotransferrin towards genus Candida

The inhibiting activity of ovotransferrin was tested towards different species belonging to genus Candida.Of one hundred strains tested, only C. krusei showed a noticeable resistance, while the other species appeared to be more sensitive than bacteria to the action of ovotransferrin. The influence of anions, such as bicarbonate and citrate, on the inhibiting activity of ovotransferrin was also investigated. Moreover it was observed that iron saturated ovotransferrin retained its activity, thus suggesting an interaction between the protein and Candida cells.     

Investigations on the turnover of adrenocortical mitochondria

Summary The effects of a chronic treatment with angiotensin II (up to 15 consecutive days) on the mitochondria of the rat zona glomerulosa cells were investigated by electron microscopic and stereological methods. Angiotensin induced a significant increase in the volume of the mitochondrial compartment. Up to the 3rd day of treatment this was due only to the hypertrophy of the organelles, and from the 3rd to the 15th day exclusively to mitochondrial proliferation. The hypothesis that angiotensin controls the growth and proliferation of rat zona glomerulosa mitochondria is discussed.     

Effects of norflurazon, an inhibitor of carotenogenesis, on abscisic acid and xanthoxin in the caps of gravistimulated maize roots

Maize seeds were germinated in the dark in the presence of the carotenoid synthesis inhibitor norflurazon and the teveis of abscisic acid, xanthoxin and total carotenoids were measured in the root cap and in the adjacent 1.5 mm segment. In norflurazon-treated roots abscisic acid levels were markedly reduced, but an increase occurred in the levels of xanthoxin, a compound structurally and physiologically similar to abscisic acid. In the cultivar of maize ( Zea mays L. cv. Merit) used for this work, brief illumination of the root is required for gravitropic curving. Following illumination both control and norflurazon-treated roots showed normal gravitropic curvature, however, the rate of curvature was delayed in norflurazon-treated roots. Our data from norflurazon-treated roots are consistent with a role for xanthoxin in maize root gravitropism. The increase in xanthoxin in the presence of an inhibitor of carotenoid synthesis suggests that xanthoxin and abscisic acid originate, at least in part, via different metabolic pathways.     

The ferroportin-ceruloplasmin system and the mammalian iron homeostasis machine: regulatory pathways and the role of lactoferrin

In the last 20 years, several new genes and proteins involved in iron metabolism in eukaryotes, particularly related to pathological states both in animal models and in humans have been identified, and we are now starting to unveil at the molecular level the mechanisms of iron absorption, the regulation of iron transport and the homeostatic balancing processes. In this review, we will briefly outline the general scheme of iron metabolism in humans and then focus our attention on the cellular iron export system formed by the permease ferroportin and the ferroxidase ceruloplasmin. We will finally summarize data on the role of the iron binding protein lactoferrin on the regulation of the ferroportin/ceruloplasmin couple and of other proteins involved in iron homeostasis in inflamed human macrophages.     

Efficacy of bovine lactoferrin in the post-surgical treatment of patients suffering from bisphosphonate-related osteonecrosis of the jaws: an open-label study

Osteonecrosis of the jaws is an emerging pathological condition characterized by un-exposure or exposure of the necrotic bone, independently from the etiology. This term is usually referred to medication-related osteonecrosis of the jaws due to severe adverse reaction to certain medicines, as bisphosphonates, used for the treatment of cancer and osteoporosis. The management of patients with Bisphosphonate-Related Osteonecrosis of the Jaws (BRONJ) remains challenging because surgical and medical interventions may not eradicate this pathology. The goal of treatment of patients at risk of developing BRONJ or of those who have active disease is the preservation of quality of life by controlling pain, managing infection, and preventing the development of new areas of necrosis. The treatment of osteonecrosis consists in the surgical removal of necrotic bone followed by antibiotic therapy and application of sterile greasy gauze until the wound closure. The classical medical treatment has been compared with the innovative one consisting in the application of sterile greasy gauze soaked with bovine lactoferrin (bLf) after surgery. Here, for the first time, bLf efficacy on wound repair in subjects suffering from BRONJ with the progressive destruction of bone in the mandible or maxilla has been demonstrated. The positive results consist in a significant shorter time of wound closure (1 or 2 weeks) compared to that observed with classical surgical treatment (2–3 months). These promising results are an interesting tool for the innovative treatment of this pathology and for increasing the quality of life of these patients.     

In vitro inhibition of HeLa cell nuclear ribonucleases by ADP-ribosylation

Regeneration of cilia in Tetrahymena cells treated with 1 µg/ml of 4,6-diamidino-2-phenylindole (DAPI) takes place about 30 min later then in untreated controls. Analysis of RNA isolated at 50-th min of reciliation, that is when the control cells – but not DAPI-treated ones — have just restored their motility, revealed that; –1. Two peaks of polyadenylated RNA were present in DAPI-treated cells as well as in the control ones; –2. The mobility of the polyadenylated RNA was the same in the two compared cell samples; –3. In wheat germ cell-free translational system these poly (A⁺)-RNA probably directed the synthesis of -and -tubulin; –4. The amount of polyadenylated RNA in compared cell samples was different, in DAPI-treated Tetrahymena its amount was estimated at 1.43% vs. 1.89% in control ones.     

New Nanometric Solid Dispersions of Glibenclamide in Neusilin<Superscript>®</Superscript> UFL2

To improve the poor water solubility and dissolution rate of the oral hypoglycemic drug glibenclamide, it was molecularly dispersed in Neusilin^® UFL2, an amorphous synthetic form of magnesium aluminometasilicate, at different proportions; the physicochemical and biopharmaceutical properties, as well as the stability of the four different batches recovered were characterised, and it was determined that complete dispersion of glibenclamide in the amorphous polymer was obtained at the drug to Neusilin ratio of 1 to 2.5. Completely amorphous dispersion was proven by Thermal Analysis and X-Ray Powder Diffractometry. Very small particles were obtained, ranging from approximately 200 to 400 nm. The amorphous batches were physically and chemically stable for the entire duration of experiments. The physicochemical properties of the four batches were compared to those of the starting materials and physical mixtures of Neusilin^® UFL2 and glibenclamide, the latter showing the typical behaviour of simple mixes, i.e., the additivity of properties of single components. The dissolution studies of the four solid dispersions revealed a very high dissolution rate of the completely amorphous batches (Batches 3 and 4), behaviour that was ascribed to their high Intrinsic dissolution rate due to the amorphous characteristics of the solid dispersions, to their very small particle size, and to the presence of polysorbate 80 that improved solid wettability. The technique under investigation thus proved effective for recovering stable amorphous dispersions of very small particle sizes.     

Dihydrofolate-Reductase Mutations in Plasmodium knowlesi Appear Unrelated to Selective Drug Pressure from Putative Human-To-Human Transmission in Sabah,Malaysia

Background

Malaria caused by zoonotic Plasmodium knowlesi is an emerging threat in Eastern Malaysia. Despite demonstrated vector competency, it is unknown whether human-to-human (H-H) transmission is occurring naturally. We sought evidence of drug selection pressure from the antimalarial sulfadoxine-pyrimethamine (SP) as a potential marker of H-H transmission.

Methods

The P. knowlesi dihdyrofolate-reductase (pkdhfr) gene was sequenced from 449 P. knowlesi malaria cases from Sabah (Malaysian Borneo) and genotypes evaluated for association with clinical and epidemiological factors. Homology modelling using the pvdhfr template was used to assess the effect of pkdhfr mutations on the pyrimethamine binding pocket.

Results

Fourteen non-synonymous mutations were detected, with the most common being at codon T91P (10.2%) and R34L (10.0%), resulting in 21 different genotypes, including the wild-type, 14 single mutants, and six double mutants. One third of the P. knowlesi infections were with pkdhfr mutants; 145 (32%) patients had single mutants and 14 (3%) had double-mutants. In contrast, among the 47 P. falciparum isolates sequenced, three pfdhfr genotypes were found, with the double mutant 108N+59R being fixed and the triple mutants 108N+59R+51I and 108N+59R+164L occurring with frequencies of 4% and 8%, respectively. Two non-random spatio-temporal clusters were identified with pkdhfr genotypes. There was no association between pkdhfr mutations and hyperparasitaemia or malaria severity, both hypothesized to be indicators of H-H transmission. The orthologous loci associated with resistance in P. falciparum were not mutated in pkdhfr. Subsequent homology modelling of pkdhfr revealed gene loci 13, 53, 120, and 173 as being critical for pyrimethamine binding, however, there were no mutations at these sites among the 449 P. knowlesi isolates.

Conclusion

Although moderate diversity was observed in pkdhfr in Sabah, there was no evidence this reflected selective antifolate drug pressure in humans.