Cone-beam computed tomography evaluation of impacted and transmigrated mandibular canines: a retrospective study

Oral Radiology - The purpose of this study is to evaluate CBCT images of impacted mandibular canines in detail and to discuss implications for diagnosis and treatment. CBCT images of dental...     

Aumento da Rigidez Arterial Pulmonar e Comprometimento do Acoplamento Ventrículo Direito-Artéria Pulmonar na SOP

Background:Polycystic ovary syndrome (PCOS) is the most common endocrine-metabolic disease in women in reproductive age, and occurs in one of 10 women. The disease includes menstrual irregularity and excess of male hormones and is the most common cause of female infertility. Dyspnea is a frequent symptom and is often thought to be due to obesity, and whether it is due to cardiac dysfunction is unknown.Objective:To evaluate right ventricle-pulmonary artery (RV-PA) coupling and pulmonary arterial stiffness in patients with PCOS.Methods:44 PCOS patients and 60 controls were included; venous blood samples were taken for laboratory tests and 2-D, m-mode and tissue doppler transthoracic echocardiography were performed for all the participants. P<0,05 was considered as statistically significant.Results:When compared to the control group, PCOS patients had higher pulmonary artery stiffness values (p=0,001), which were positively correlated with HOMA-IR (r=0,545 and p<0,001). RV-PA coupling was also impaired in 34% of the study patients.Conclusion:Pulmonary artery stiffness is increased and RV-PA coupling is impaired in patients with PCOS. (Arq Bras Cardiol. 2021; 116(4):806-811)Palavras-chave: Diseases of the Endocrine System, Arterial Stiffness, Female infertility, Obesity, Dyspnea, Pulmonary hypertension     

Pulmonary arteriovenous malformation in children

Although pulmonary arteriovenous malformations (PAVM) are relatively rare in children, they are important in the differential diagnosis of common pulmonary problems, such as hypoxemia, hemoptysis and dyspnea on exertion. We report the cases of two PAVM patients with different presentations and describe the treatment strategies.     

Increased oxidative stress in children exposed to passive smoking

BACKGROUND: Atherogenic process is accelerated with cigarette smoke that contains many oxidants and prooxidants, capable of producing free radical and enhancing the oxidative stress. We investigated oxidative and antioxidative status of children who had been exposed to passive smoking and compared with those of not exposed group. METHODS: One hundred forty-three school children aged 9-13 years, 61 of whom had never been exposed to passive smoking, and 82 of whom had been exposed to passive smoking at least 10 cigarette per day for at least last 1 year in their house, were enrolled in this study. Total antioxidative response (TAR) was measured to determine antioxidative status of plasma, and total peroxide concentration was measured to determine oxidative status of plasma. The ratio of TAR to total peroxide was accepted as an indicator of oxidative stress. RESULTS: TAR of plasma was significantly lower in children exposed to passive smoking than in those of not exposed group (p=0.018). Mean (S.D.) values were 1.49 (0.07) and 1.52 (0.08) mmol Trolox Equiv./l, respectively. In contrary, the mean (S.D.) total peroxide level of plasma was significantly higher in children exposed to passive smoking [13.06 (2.34) micromol H2O2/l] than in not exposed group [12.24 (1.74) micromol H2O2/l] (p=0.015). The mean (S.D.) oxidative stress index (OSI) value was significantly higher in the children exposed to passive smoking [0.87 (0.15)] than in not exposed group [0.80 (0.10)] (p=0.001). CONCLUSION: Children who are exposed to passive smoking are exposed to oxidative stress, which has been implicated in the etiopathogenesis of over 100 disorders including atherosclerosis.     

INAUGURAL ARTICLE by a Recently Elected Academy Member:Nonsteroidal anti-inflammatory drug sensitizes Mycobacterium tuberculosis to endogenous and exogenous antimicrobials

Existing drugs are slow to eradicate Mycobacterium tuberculosis (Mtb) in patients and have failed to control tuberculosis globally. One reason may be that host conditions impair Mtb’s replication, reducing its sensitivity to most antiinfectives. We devised a high-throughput screen for compounds that kill Mtb when its replication has been halted by reactive nitrogen intermediates (RNIs), acid, hypoxia, and a fatty acid carbon source. At concentrations routinely achieved in human blood, oxyphenbutazone (OPB), an inexpensive anti-inflammatory drug, was selectively mycobactericidal to nonreplicating (NR) Mtb. Its cidal activity depended on mild acid and was augmented by RNIs and fatty acid. Acid and RNIs fostered OPB’s 4-hydroxylation. The resultant 4-butyl-4-hydroxy-1-(4-hydroxyphenyl)-2-phenylpyrazolidine-3,5-dione (4-OH-OPB) killed both replicating and NR Mtb, including Mtb resistant to standard drugs. 4-OH-OPB depleted flavins and formed covalent adducts with N-acetyl-cysteine and mycothiol. 4-OH-OPB killed Mtb synergistically with oxidants and several antituberculosis drugs. Thus, conditions that block Mtb’s replication modify OPB and enhance its cidal action. Modified OPB kills both replicating and NR Mtb and sensitizes both to host-derived and medicinal antimycobacterial agents.Some bacterial infections can be cured with a single dose of an antibiotic, and most others can be cured with administration of one drug over several days or weeks. In contrast, routine treatment of drug-sensitive tuberculosis (TB) takes 2 mo of therapy with four drugs and an additional 4 mo with two drugs to reduce the 2-y relapse rate below 5%. The difficulty of completing prolonged treatment is a major reason for emergence of drug resistance. When the infecting strain is resistant to isoniazid and rifampin, the two drugs recommended for all 6 mo of treatment, cure often requires 2 y of daily administration of toxic, expensive, second-line agents that are often unavailable at the point of care. When the causative strain is additionally resistant to a quinolone and an aminoglycoside, the resultant “extensively drug-resistant” TB was fatal to 80% of patients in a leading center (1), although complex multidrug regimens have achieved higher cure rates in populations not previously exposed to the additional drugs (2). In addition to sharing air with someone with TB, leading risk factors for contracting the disease are malnutrition, HIV infection, diabetes, and exposure to smoke from cigarettes or cooking fires (3). These epidemiological challenges exacerbate problems of inadequate diagnostic technology and limited access to drug susceptibility testing and to drugs. Control of the pandemic is not in sight (3).It is widely hypothesized that treatment of TB is protracted because nonreplicating (NR) subpopulations of bacilli are phenotypically tolerant to drugs that were selected for activity against replicating (R) Mycobacterium tuberculosis (Mtb) (4). Mtb can occupy diverse microenvironments in the host. Evidence from auxotrophs, analyses of gene expression, and direct and indirect biochemical measurements in vivo or ex vivo in experimental animals and people suggest that such environments expose Mtb to acid, hypoxia, reactive nitrogen intermediates (RNIs), oxidative stress, carbohydrate deficiency, and metal starvation or intoxication, and require Mtb to metabolize fatty acids or cholesterol (5–17). In vitro, many of the same conditions can make Mtb relatively refractory to killing by the standard agents, except for pyrazinamide, which is only effective at a low pH.Thus, there is a need for a high-throughput screen (HTS) for compounds that kill Mtb when the Mtb has been rendered NR by a combination of physiologically relevant host-imposed conditions. We were encouraged to devise such a screen by recent discoveries of a class of compounds that kill Mtb only when it is NR (18), an antibiotic in clinical use for other infections that kills NR Mtb better than R Mtb (19), and a compound that kills NR and R Mtb equally well (20). Unfortunately, only one of those compounds is an approved drug, and even if it were of proven utility in TB, its price would preclude its use by most of those who need it. We decided to screen other existing drugs that are not regarded as antiinfectives for those that kill NR Mtb. Here, we report finding such a drug in an HTS that combined four host-imposed conditions, some of which converted the drug into a form active on both R and NR Mtb.     

Risk factors for avascular bone necrosis in patients with systemic lupus erythematosus

The objective was to investigate the predictive factors for avascular necrosis (AVN) of bone in patients with systemic lupus erythematosus (SLE). The records of 868 patients with SLE from four centers were reviewed retrospectively. Forty-nine patients with AVN were identified. A total of 154 patients with SLE who did not have clinically apparent AVN during the follow-up were evaluated as a control group. The demographic, clinical, laboratory and management characteristics of these two groups of patients were recorded according to predefined protocol and compared. The prevalence of AVN was detected 6% in our SLE population. The highest dose corticosteroid administered within 4?months and total cumulative prednisolone dose were significantly higher in the SLE patients with AVN. The use of cytotoxic agent significantly higher proportion of patients with AVN. AVN tends to develop more frequently in male gender and younger patients. Oral ulcer, pleuritis, Raynaud??s phenomenon, cutaneous vasculitis, lymphadenopathy, autoimmune thyroiditis, peripheral neuropathy and Sj?gren??s syndrome were higher incidence in SLE patients with AVN. The bilateral femoral heads were the commonest site of involvement of AVN in our patients with SLE.     

Arg-Phe-amide-related peptides influence gonadotropin-releasing hormone neurons

The hypothalamic Arg-Phe-amide-related peptides, gonadotropin-inhibitory hormone and orthologous mammalian peptides of Arg-Phe-amide, may be important regulators of the hypothalamus-pituitary-gonadal reproductive axis. These peptides may modulate the effects of kisspeptins because they are presently recognized as the most potent activators of the hypothalamus-pituitary-gonadal axis. However, their effects on gonadotropin-releasing hormone neurons have not been investigated. In the current study, the GT1-7 cell line-expressing gonadotropin-releasing hormone was used as a model to explore the effects of Arg-Phe- amide-related peptides on kisspeptin activation. Intracellular calcium concentration was quantified using the calcium-sensitive dye, fura-2 acetoxymethyl ester. Gonadotropin-releasing hormone released into the medium was detected via enzyme-linked immunosorbent assay. Results showed that 100 nmol/L kisspeptin-10 significantly increased gonadotropin-releasing hormone levels (at 120 minutes of exposure) and intracellular calcium concentrations. Co-treatment of kisspeptin with 1 μmol/L gonadotropin-inhibitory hormone or 1 μmol/L Arg-Phe-amide-related peptide-1 significantly attenuated levels of kisspeptin-induced gonadotropin-releasing hormone but did not affect kisspeptin-induced elevations of intracellular calcium concentration. Overall, the results suggest that gonadotropin-inhibitory hormone and Arg-Phe-amide-related peptide-1 may have inhibitory effects on kisspeptin-activated gonadotropin-releasing hormone neurons independent of the calcium signaling pathway.     

Effect of thiophene linker addition to fluorene-benzotriazole polymers with the purpose of achieving white emission in OLEDs

With the purpose of obtaining white emission from single layer organic light emitting diodes (OLEDs), fluorene benzotriazole based polymers with double bond subunits (namely TP2 and SP3 with and without thiophene linker, respectively) were synthesized by a Suzuki cross-coupling polymerization reaction. SP3 and TP2 were used as an emissive layer of the OLED devices due to their outstanding solubility in organic solvents, photoluminescence intensity and morphological suitability for fine thin film-forming capability. The optical, electrochemical, light emission and electroluminescence characteristics, Density Functional Theory (DFT) calculations and admittance spectroscopic analysis of OLEDs based on SP3 and TP2 were realized in detail to understand the effects of thiophene linker addition as a donor unit to the main chain of fluorene benzotriazole based polymers. As a result, TP2 emitted a bright yellow emission with a maximum brightness of 243 cd m⁻² at 40 mA cm⁻², and a maximum current efficiency of 1.38 cd A⁻¹ with more broad electroluminescence characteristics than SP3 polymer without the thiophene linker. SP3 emitted a greenish yellow emission with a maximum brightness of 1001 cd m⁻² at 845 mA cm⁻², and a maximum current efficiency of 0.33 cd A⁻¹. Carrier transport properties, charge carrier transit time and the equivalent circuit modelling studies were obtained through admittance spectroscopy. An equivalent circuit model with a combination of two resistors and one capacitor explained the charge conduction mechanism of SP3 and TP2 based OLEDs. SP3 and TP2 OLED devices represented typical p-type transporting characteristics with mobilities of 0.073 and 0.017 cm² V⁻¹ s⁻¹, respectively with simplified device configuration. All the results indicate that thiophene addition to the main chain of fluorene benzotriazole based polymers with double bond subunits lead to a promising candidate for white emissive materials used in single layer white OLEDs.

Fluorene-benzotriazole based polymers with double bound subunits were prepared for white light electroluminescence applications.