Nanocarriers for optimizing the balance between interfollicular permeation and follicular uptake of topically applied clobetasol to minimize adverse effects.

The treatment of various hair disorders has become a central focus of good dermatologic patient care as it affects men and women all over the world. For many inflammatory-based scalp diseases, glucocorticoids are an essential part of treatment, even though they are known to cause systemic as well as local adverse effects when applied topically. Therefore, efficient targeting and avoidance of these side effects are of utmost importance. Optimizing the balance between drug release, interfollicular permeation, and follicular uptake may allow minimizing these adverse events and simultaneously improve drug delivery, given that one succeeds in targeting a sustained release formulation to the hair follicle. To test this hypothesis, three types of polymeric nanocarriers (nanospheres, nanocapsules, lipid-core nanocapsules) for the potent glucocorticoid clobetasol propionate (CP) were prepared. They all exhibited a sustained release of drug, as was desired. The particles were formulated as a dispersion and hydrogel and (partially) labeled with Rhodamin B for quantification purposes. Follicular uptake was investigated using the Differential Stripping method and was found highest for nanocapsules in dispersion after application of massage. Moreover, the active ingredient (CP) as well as the nanocarrier (Rhodamin B labeled polymer) recovered in the hair follicle were measured simultaneously, revealing an equivalent uptake of both. In contrast, only negligible amounts of CP could be detected in the hair follicle when applied as free drug in solution or hydrogel, regardless of any massage. Skin permeation experiments using heat-separated human epidermis mounted in Franz Diffusion cells revealed equivalent reduced transdermal permeability for all nanocarriers in comparison to application of the free drug. Combining these results, nanocapsules formulated as an aqueous dispersion and applied by massage appeare to be a good candidate to maximize follicular targeting and minimize drug penetration into the interfollicular epidermis. We conclude that such nanotechnology-based formulations provide a viable strategy for more efficient drug delivery to the hair follicle. Moreover, they present a way to minimize adverse effects of potent glucocorticoids by releasing the drug in a controlled manner and simultaneously decreasing interfollicular permeation, offering an advantage over conventional formulations for inflammatory-based skin/scalp diseases.

Improved tretinoin photostability in a topical nanomedicine replacing original liquid suspension with spray-dried powder with no loss of effectiveness.

OBJECTIVE: The use of spray-dried powders containing tretinoin-loaded nanocapsules instead of the original liquid suspension, aimed at the preparation of dermatological nanomedicines with improved photostability, was investigated. METHODS: Powders were prepared using lactose as a drying adjuvant. Hydrogels were prepared using two approaches: dispersing Carbopol Ultrez 10 in an aqueous redispersion of the powder or incorporating the powder in previously formed hydrogels. RESULTS AND DISCUSSION: The photodegradation of tretinoin in hydrogels prepared with the powders showed similar half-life times (around 19.5 h) compared to preparations with the original liquid nanocapsules (20.7 ± 1.4 h), regardless of the preparation approach. In addition, the topical nanomedicines prepared with the spray-dried powders presented a significant improvement in tretinoin photostability compared to the formulation containing the non-encapsulated drug. CONCLUSION: This study verified that the addition of the spray-dried powders containing tretinoin-loaded lipid-core nanocapsules to hydrogels did not influence the photoprotection of the drug compared with the preparation procedure using the original liquid suspension.

Overdentures on implants placed in bone augmented with fresh frozen bone.

AIM: In the last decade several studies have been performed to evaluate the clinical outcome of one or two stage loaded implants supporting overdentures. Since fresh frozen bone (FFB) has an ever-increasing number of clinical applications and few reports are available on implants inserted into FFB, we performed a retrospective study on fixtures inserted in FFB and bearing overdentures. METHODS: In the period between December 2003 and December 2006, 17 patients (14 females and 3 males with a median age of about 56 years) were grafted and 60 implants inserted thereafter. A total of 17 overdentures were delivered: 8 in the mandible and 9 in the maxilla. Multiple implant systems were used: 22 Double etched, 7 SLA, 9 Anodic oxidized, and 22 CaPo4 ceramic-blasted. Implant diameter ranged from 3.25 to 4.3 mm and length from 11.5 to 16.0 mm. Implants were inserted to replace 23 incisors, 9 cuspids, 20 premolars and 8 molars. RESULTS: No implants were lost (i.e., survival rate=100%) and no differences were detected among the studied variables. Kaplan Meier algorithm and Cox regression did not reveal any statistical differences among the studied variables also as regards the success rate. CONCLUSION: Implants inserted FFB and bearing overdentures have a high survival rate and success rates, which are comparable to those of implants inserted in non-grafted bone. FFB bone is a reliable material for alveolar ridge augmentation. No difference was detected among removable prostheses supported by two or more implants.

Naringenin regulates expression of genes involved in cell wall synthesis in Herbaspirillum seropedicae.

Five thousand mutants of Herbaspirillum seropedicae SmR1 carrying random insertions of transposon pTnMod-OGmKmlacZ were screened for differential expression of LacZ in the presence of naringenin. Among the 16 mutants whose expression was regulated by naringenin were genes predicted to be involved in the synthesis of exopolysaccharides, lipopolysaccharides, and auxin. These loci are probably involved in establishing interactions with host plants.

Hydrogel containing dexamethasone-loaded nanocapsules for cutaneous administration: preparation, characterization, and in vitro drug release study.

CONTEXT: Our group previously reported the development of dexamethasone-loaded polymeric nanocapsules as an alternative for topical dermatological treatments. OBJECTIVE: Our study aimed to prepare and characterize a hydrogel containing this system to improve the effectiveness of the glucocorticoid for cutaneous disorders. METHODS: For the antiproliferative activity assay, a dexamethasone solution and D-NC were tested on Allium cepa root meristem model. D-NC were prepared by the interfacial deposition of preformed polymer. Hydrogels were prepared using Carbopol Ultrez 10 NF, as polymer, and characterized according to the following characteristics: pH, drug content, spreadability, viscosity, and in vitro drug release. RESULTS AND DISCUSSION: Nanocapsules showed mean particle size and zeta potential of 201 +/- 6 and -5.73 +/- 0.42 nm, respectively. They demonstrated a lower mitotic index (4.62%) compared to free dexamethasone (8.60%). Semisolid formulations presented acidic pH values and adequate drug content (between 5.4% and 6.1% and 100% and 105%, respectively). The presence of nanocapsules in hydrogels led to a decrease in their spreadability factor. Intact nanoparticles were demonstrated by TEM as well as by dynamic light scattering (mean particle size < 300 nm). In vitro studies showed a controlled dexamethasone release from hydrogels containing the drug associated to the nanocapsules following the Higuchi's squared root model (k = 20.21 +/- 2.96 mg/cm(2)/h(1/2)) compared to the hydrogels containing the free drug (k = 26.65 +/- 2.09 mg/cm(2)/h(1/2)). CONCLUSION: Taking all these results together, the hydrogel containing D-NC represent a promising approach to treat antiproliferative-related dermatological disorders.

Influence of soil characteristics on the diversity of bacteria in the Southern Brazilian Atlantic Forest.

The Brazilian Atlantic Forest is one of the 25 biodiversity hot spots in the world. Although the diversity of its fauna and flora has been studied fairly well, little is known of its microbial communities. In this work, we analyzed the Atlantic Forest ecosystem to determine its bacterial biodiversity, using 16S rRNA gene sequencing, and correlated changes in deduced taxonomic profiles with the physicochemical characteristics of the soil. DNAs were purified from soil samples, and the 16S rRNA gene was amplified to construct libraries. Comparison of 754 independent 16S rRNA gene sequences from 10 soil samples collected along a transect in an altitude gradient showed the prevalence of Acidobacteria (63%), followed by Proteobacteria (25.2%), Gemmatimonadetes (1.6%), Actinobacteria (1.2%), Bacteroidetes (1%), Chloroflexi (0.66%), Nitrospira (0.4%), Planctomycetes (0.4%), Firmicutes (0.26%), and OP10 (0.13%). Forty-eight sequences (6.5%) represented unidentified bacteria. The Shannon diversity indices of the samples varied from 4.12 to 3.57, indicating that the soils have a high level of diversity. Statistical analysis showed that the bacterial diversity is influenced by factors such as altitude, Ca(2+)/Mg(2+) ratio, and Al(3+) and phosphorus content, which also affected the diversity within the same lineage. In the samples analyzed, pH had no significant impact on diversity.

Solitary neurofibroma of the palate. A case report.

The neurofibroma is a benign tumor of neuronal origin not frequently located in the oral cavity. The possible association of this neoplasia with systemic pathologies, such as Von Recklinghausen's disease and multiple endocrine neoplasia, makes its diagnosis fundamental. The diagnosis is, in most cases, quite complex, because of the neurofibroma's strong similarities with a great number of benign neoformations of the connective tissue, of the epithelium, and of the bone. The histology represents, therefore, the fundamental diagnostic criterion, in particular, through the use of appropriate immunohistochemical analysis. This articles presents the case of a solitary neurofibroma, subtype I (common Schwann cell type), detected on the left-hand side of the posterior region of the palate in a 56-year-old woman, which presented itself as an otherwise non-symptomatic ulcerated mass. After a careful anamnesis, an incisional biopsy was performed in order to establish the histological nature of the neoformation. The immunohistochemical test, which resulted positive for S-100 and negative for the epithelial membrane antigen and keratin, allowed the diagnosis of a presumably benign lesion deriving from a neural differentiation. The surgical excision of the entire mass was accompanied by the extraction of the upper left-hand second molar, which was attached to the mass through its palatal root.

Severe spontaneous arterial thrombotic manifestations in patients with inherited hypo- and afibrinogenemia.

We report two novel cases of severe arterial thrombotic episodes occurring in two women with severe hypofibrinogenemia, not linked to the administration of replacement therapy. The first patient had sudden acute occlusion of the anterior branch of left renal artery with infarction of the antero-lateral region of the upper part of the left kidney during treatment with combined oestrogen-progestogen started 16 years before for recurrent haemoperitoneum caused by bleeding at ovulation. The second patient showed recurrent arterial thrombosis of lower limbs over 2 years, which eventually led to amputation of affected limbs. Thrombotic events in patients with inherited severe hypofibrinogenemia are rather frequent, may be severe and not associated with the use of replacement therapy.

A prospective study on Shiga toxin-producing Escherichia coli in children with diarrhea in Paraná State, Brazil.

AIMS: To examine stool specimens from children with diarrhea from Paraná State, southern Brazil, for presence of STEC. METHODS AND RESULTS: A PCR screening assay for stx genes was used to examine a loopful of confluent colonies of 306 stool samples cultures. In six (1.96%) of them, DNA fragments of the expected size were observed, and the presence of stx was confirmed by DNA sequencing. Then up to 100 single colonies from each of the six stool cultures were analyzed using the same PCR protocol. However, stx-positive colonies were found only in two of the cultures. The E. coli strains belonged to serotypes O69:H11 and O178:H19, and presented genotypes stx(1)eae ehxA and stx(1) respectively. Shiga toxin production was confirmed using the VTEC Screen Seiken. Except ampicillin, they were susceptible to all the antimicrobials tested. CONCLUSIONS: These results show that STEC may be an important cause of diarrhea in children of Paraná State, and that they are present in low numbers in stools. The strains belonged to serotypes not commonly found associated with STEC and probably present low virulence. SIGNIFICANCE AND IMPACT OF STUDY: These results indicate that molecular methods are required to diagnosis of STEC infections.

Phenotypic and genotypic traits of Shiga toxin-producing Escherichia coli strains isolated from beef cattle from Paraná State, southern Brazil.

AIMS: To investigate the prevalence and characteristics of Shiga toxin-producing Escherichia coli (STEC) in cattle from Paraná State, southern Brazil. METHODS AND RESULTS: One hundred and seven faeces cattle samples were cultured on Sorbitol-MacConkey agar. Escherichia coli colonies were tested for production of Shiga toxin using Vero-cell assay. A high prevalence (57%) of STEC was found. Sixty-four STEC were serotyped and examined for the presence of stx(1), stx(2), eae, ehxA and saa genes and stx(2) variants. The isolates belonged to 31 different serotypes, of which three (O152:H8, O175:H21 and O176:H18) had not previously been associated with STEC. A high prevalence of stx(2)-type genes was found (62 strains, 97%). Variant forms found were stx(2), stx(2c), stx(2vhb), stx(2vO111v/OX393) and a form nonclassifiable by PCR-RFLP. The commonest genotypes were stx(2)ehxA saa and stx(1)stx(2)ehxA saa. CONCLUSIONS: A high frequency of STEC was observed. Several strains belong to serotypes previously associated with human disease and carry stx(2) and other virulence factors, thus potentially representing a risk to human health. SIGNIFICANCE AND IMPACT OF THE STUDY: This is the first study of STEC in Paraná State, and its findings emphasize the need for proper cattle handling to prevent human contamination.

Electronic dental anaesthesia for third inferior molar surgery.

AIM: The aim of this study was to evaluate the efficacy of Electronic Dental Anaesthesia (EDA) for third molar surgery. METHODS: Third molar extraction under regional anaesthesia (inferior alveolar and buccal nerve blocks) was performed in 2 groups of 30 patients each: group 1 = controls, group 2 = EDA treatment. Anxiety and pain level were reported by means of Visual Analogue Scale, postoperative pain description with the McGill Pain Questionnaire. A postoperative phone interview to all patients was made. Computerized randomization was performed; values expressed as mean+/-SD, data comparison evaluated by means of ANOVA and chi squared, statistical significance indicated by P values <0.05. RESULTS: Features of the patients and surgical interventions were similar. EDA has determined lower pain level; moreover, the control patients has shown higher values of blood pressure and heart frequency. Phone interview has reported no amnesia about the perioperative events. A smaller number of EDA treated patients has reported pain during needle prick and/or intraoperatively; 80% of the EDA treated patients has reported a good opinion about the treatment, 93% of the patients would repeat the treatment, if needed. CONCLUSION: EDA is a complementary analgesic technique for dental surgery. Cardiovascular changes, frequently observed during third molar extraction, were not present in the EDA treated patients. These data confirm that EDA is able to modify the physiologic responses to stressful events, blunting the adrenergic upset, maybe by means of an analgesic action on A, fiber and an increase of endorphins' central level. These results underline that the complementary use of EDA in the third molar extraction may be better than regional anaesthesia alone.

Control of nitrogenase reactivation by the GlnZ protein in Azospirillum brasilense.

The glnZ mutant of Azospirillum brasilense (strain 7611) showed only partial recovery (20 to 40%) after 80 min of ammonia-induced nitrogenase switch-off, whereas the wild type recovered totally within 10 min. In contrast, the two strains showed identical anoxic-induced switch-on/switch-off, indicating no cross talk between the two reactivation mechanisms.

Recent developments in the structural organization and regulation of nitrogen fixation genes in Herbaspirillum seropedicae.

Herbaspirillum seropedicae is a nitrogen-fixing bacterium found in association with economically important gramineae. Regulation of nitrogen fixation involves the transcriptional activator NifA protein. The regulation of NifA protein and its truncated mutant proteins is described and compared with that of other nitrogen fixation bacteria. Nitrogen fixation control in H. seropedicae, of the beta-subgroup of Proteobacteria, has regulatory features in common with Klebsiella pneumoniae, of the gamma-subgroup, at the level of nifA expression and with rhizobia and Azospirillum brasilense, of the alpha-subgroup, at the level of control of NifA by oxygen.

The transcriptional activator NtrC controls the expression and activity of glutamine synthetase in Herbaspirillum seropedicae.

The role of the Ntr system in Herbaspirillum seropedicae was determined via ntrB and ntrC mutants. Three phenotypes were identified in these mutants: Nif(-), deficiency in growth using nitrate, and low glutamine synthetase (GS) activity. All phenotypes were restored by the plasmid pKRT1 containing the intact glnA, ntrB and ntrC genes of H. seropedicae. The promoter region of glnA was subcloned into a beta-galactosidase fusion vector and the results suggested that NtrC positively regulates the glnA promoter in response to low nitrogen. The H. seropedicae ntrC and ntrB mutant strains showed a deficiency of adenylylation/deadenylylation of GS, indicating that NtrC and NtrB are involved in both transcription and activity control of GS in this organism.

Expression of the nifA gene of Herbaspirillum seropedicae: role of the NtrC and NifA binding sites and of the -24/-12 promoter element.

The nifA promoter of Herbaspirillum seropedicae contains potential NtrC, NifA and IHF binding sites together with a -12/-24 sigma(N)-dependent promoter. This region has now been investigated by deletion mutagenesis for the effect of NtrC and NifA on the expression of a nifA::lacZ fusion. A 5' end to the RNA was identified at position 641, 12 bp downstream from the -12/-24 promoter. Footprinting experiments showed that the G residues at positions -26 and -9 are hypermethylated, and that the region from -10 to +10 is partially melted under nitrogen-fixing conditions, confirming that this is the active nifA promoter. In H. seropedicae nifA expression from the sigma(N)-dependent promoter is repressed by fixed nitrogen but not by oxygen and is probably activated by the NtrC protein. NifA protein is apparently not essential for nifA expression but it can still bind the NifA upstream activating sequence.

Genome structure of the genus Azospirillum.

Azospirillum species are plant-associated diazotrophs of the alpha subclass of Proteobacteria. The genomes of five of the six Azospirillum species were analyzed by pulsed-field gel electrophoresis. All strains possessed several megareplicons, some probably linear, and 16S ribosomal DNA hybridization indicated multiple chromosomes in genomes ranging in size from 4.8 to 9.7 Mbp. The nifHDK operon was identified in the largest replicon.

Sequencing and functional analysis of the nifENXorf1orf2 gene cluster of Herbaspirillum seropedicae.

A 5.1-kb DNA fragment from the nifHDK region of H. seropedicae was isolated and sequenced. Sequence analysis showed the presence of nifENXorf1orf2 but nifTY were not present. No nif or consensus promoter was identified. Furthermore, orf1 expression occurred only under nitrogen-fixing conditions and no promoter activity was detected between nifK and nifE, suggesting that these genes are expressed from the upstream nifH promoter and are parts of a unique nif operon. Mutagenesis studies indicate that nifN was essential for nitrogenase activity whereas nifXorf1orf2 were not. High homology between the C-terminal region of the NifX and NifB proteins from H. seropedicae was observed. Since the NifX and NifY proteins are important for FeMo cofactor (FeMoco) synthesis, we propose that alternative proteins with similar activities exist in H. seropedicae.

Regulation of Azospirillum brasilense nifA gene expression by ammonium and oxygen.

The structure and activity of the nifA promoter of Azospirillum brasilense was studied using deletion analysis. An essential region for nifA promoter activity was identified between nucleotides -67 and -47 from the identified transcription start site. A sequence resembling a sigma(70) recognition site occurs in this region and may constitute the nifA gene promoter. The regulation of the nifA gene was studied in plasmid and chromosomal nifA::lacZ fusions. Full expression was obtained under low oxygen levels and in the absence of ammonium ions. Repression of nifA expression involves a synergistic effect between oxygen and ammonium.

Alcohol and smoking as risk factors in chronic pancreatitis and pancreatic cancer.

The aim of this study was to compare alcohol and smoking as risk factors in the development of chronic pancreatitis and pancreatic cancer. We considered only male subjects: (1) 630 patients with chronic pancreatitis who developed 12 pancreatic and 47 extrapancreatic cancers; (2) 69 patients with histologically well documented pancreatic cancer and no clinical history of chronic pancreatitis; and (3) 700 random controls taken from the Verona polling list and submitted to a complete medical check-up. Chronic pancreatitis subjects drink more than control subjects and more than subjects with pancreatic cancer without chronic pancreatitis (P<0.001). The percentage of smokers in the group with chronic pancreatitis is significantly higher than that in the control group [odds ratio (OR) 17.3; 95% CI 12.6-23.8; P<0.001] and in the group with pancreatic carcinomas but with no history of chronic pancreatitis (OR 5.3; 95% CI 3.0-9.4; P<0.001). In conclusion, our study shows that: (1) the risk of chronic pancreatitis correlates both with alcohol intake and with cigarette smoking with a trend indicating that the risk increases with increased alcohol intake and cigarette consumption; (2) alcohol and smoking are statistically independent risk factors for chronic pancreatitis; and (3) the risk of pancreatic cancer correlates positively with cigarette smoking but not with drinking.