Transition metal-substituted cobalt ferrite nanoparticles for biomedical applications

Transition metals of copper, zinc, chromium and nickel were substituted into cobalt ferrite nanoparticles via a sol–gel route using citric acid as a chelating agent. The microstructure and elemental composition were characterized using scanning electron microscopy combined with energy-dispersive X-ray spectroscopy. Phase analysis of transition metal-substituted cobalt ferrite nanoparticles was performed via X-ray diffraction. Surface wettability was measured using the water contact angle technique. The surface roughness of all nanoparticles was measured using profilometry. Moreover, thermogravimetric analysis and differential scanning calorimetry were performed to determine the temperature at which the decomposition and oxidation of the chelating agents took place. Results indicated that the substitution of transition metals influences strongly the microstructure, crystal structure and antibacterial property of the cobalt ferrite nanoparticles.     

The effect of intraosseous local anesthesia of 4% articaine with 1:100,000 epinephrine on pulpal blood flow and pulpal anesthesia of mandibular molars and canines

Objectives

The aim of this study was to determine the effect of intraosseous (IO) anesthesia with 4% articaine and 1:100,000 epinephrine on pulpal blood flow (PBF) and pulpal anesthesia of mandibular first molars and canines in human subjects.

Materials and methods

Ten healthy volunteers with intact mandibular first molar and canine were given an osteocentral technique of IO injection using the Quick Sleeper 5 system and 4% articaine with 1:100,000 epinephrine at distal site of mandibular first molar. The PBF was monitored by a laser Doppler flowmeter (LDF). Pulpal anesthesia was assessed with an electric pulp tester (EPT).

Results

IO injection caused a decrease in PBF in molars from 6.31 ± 3.85 perfusion units (P.U.) before injection to 2.51 ± 2.53 P.U. 1 min after injection (P < 0.001). The percentage reduction in PBF was 60% after 1 min and PBF returned back to the baseline after 45 min. No significant reduction in PBF was observed in the canines (P = 0.212). For pulpal anesthesia in the molars, the mean onset was 2.40 ± 0.84 min and the mean duration was 38 ± 16.19 min. In the canines, there was a decrease in the sensitivity to EPT but complete pulpal anesthesia was not achieved.

Conclusions

IO injection distal to mandibular first molar caused a decrease in PBF and successful pulpal anesthesia in first molar, but not in canine. Both PBF and EPT readings returned to normal, suggesting that pulpal ischemia may not occur.

Clinical relevance

IO anesthesia is safe to use as a primary technique in teeth with normal pulp.

     

Lipoid pneumonia associated with diabetes mellitus type II in a cat

Our purpose is to report a rare case of lipoid pneumonia found in a cat with diabetes mellitus (DM) type II. The cat is an aged, mixed-breed male with a 3-year history of having DM. During the last 16?weeks of its life, the cat presented signs of dyspnea and weakness and was continuously treated by nebulization. Thoracic radiography showed an increased radiopacity of the alveoli. The histopathological findings showed typical lipoid pneumonia, proliferative bronchitis, and diffuse suppurative pneumonia. Chronic pancreatitis with islet amyloidosis and arteriosclerosis was also detected. Immunohistochemistry with anti-Amylin antibody showed a strong positive result in the islet of Langerhans, confirming type II DM in this case. A diagnosis of death from respiratory failure associated with idiopathic lipoid pneumonia was achieved.     

Evidence for histamine in the urticating hairs of Hylesia moths

An urticarial dermatosis after contact with the urticating hairs of the adult female Hylesia moth may occur by several mechanisms including the intradermal injection of inflammatory mediators through the urticating hairs. Extracts were prepared from whole moths, urticating hairs, and other moth parts. Each of these extracts was subjected to a radioenzyme assay for histamine. Histamine was present in extracts made from whole moths and from urticating hairs. Extracts made from other moth parts contained no histamine. Cutaneous wheals occurred after intradermal injections of histamine and various concentrations of Hylesia extract (HE) into the backs of cynomolgus monkeys. This whealing response was suppressed by pretreatment of the animals with diphenhydramine hydrochloride, but not by pretreatment with indomethacin. Histologic examinations showed a perivascular lymphocytic infiltrate around dilated capillaries without evidence of mast cell degranulation in HE-injected sites but not in controls. These findings provide evidence that histamine may be the mediator responsible for the urticarial lesions seen after contact with Hylesia moths.     

Autoxidation of brain homogenates from various animals as measured by thiobarbituric acid assay

INTRODUCTION: The TBARS assay has been well recognized for determination of lipid peroxidation and oxidative injury in biological samples including brain homogenates. In general, the homogenates are freshly prepared using rat brains as the tissue sources. In this study, we compared the rates of spontaneous lipid peroxidation in brain homogenates obtained from bovine, canine, hen, rat, and swine. In addition, the influences of lyophilization process and storage time up to six months at -20 degrees C without the freeze-thaw cycle were also determined in the swine brain preparations. METHODS: The standard assay for thiobarbituric acid-reactive substances (TBARS) was performed at 37 degrees C, using spectrophotometry to quantify the malondialdehyde (MDA) content. RESULTS: Rat brain homogenate exhibited the highest autoxidation rate (0.128+/-0.002 microM/min) whereas the bovine brain exhibited the lowest rate (0.032+/-0.001 microM/min). Swine brain homogenate could be kept at -20 degrees C up to 3 months without a significant increase in rate of autoxidation. Lyophilization caused a significant increase in the autoxidation rate of brain homogenate. However, the autoxidation rates of the lyophilized preparation were quite comparable throughout the six-month freezing time. DISCUSSION: Swine brain was a good candidate for tissue source in the TBARS reaction. The homogenate could be kept in the lyophilized form under the storage condition at -20 degrees C without the freeze-thaw cycle in the dark for at least six months.     

South‐East Asia study alliance guidelines on the management of acne vulgaris in South‐East Asian patients

The management of acne in South‐East Asia is unique, as Asian skin and local variables require a clinical approach unlike that utilized in other parts of the world. There are different treatment guidelines per country in the region, and a group of leading dermatologists from these countries convened to review these guidelines, discuss current practices and recent advances, and formulate consensus guidelines to harmonize the management of acne vulgaris in the region. Emphasis has been placed on formulating recommendations to impede the development of antibiotic resistance in Propionibacterium acnes. The group adopted the Acne Consensus Conference system for grading acne severity. The group recommends that patients may be treated with topical medications including retinoids, benzoyl peroxide (BPO), salicylic acid, a combination of retinoid and BPO, or a combination of retinoids and BPO with or without antibiotics for mild acne; topical retinoid with topical BPO and a oral antibiotic for moderate acne; and oral isotretinoin if the patient fails first‐line treatment (a 6‐ or 8‐week trial of combined oral antibiotics and topical retinoids with BPO) for severe acne. Maintenance acne treatment using topical retinoids with or without BPO is recommended. To prevent the development of antibiotic resistance, topical antibiotics should not be used as monotherapy or used simultaneously with oral antibiotics. Skin care, comprised of cleansing, moisturizing and sun protection, is likewise recommended. Patient education and good communication is recommended to improve adherence, and advice should be given about the characteristics of the skin care products patients should use.     

Pulpal blood flow recorded from human premolar teeth with a laser Doppler flow meter using either red or infrared light

Objective

To compare red (635 nm) and infrared (780 nm) light for recording pulpal blood flow from human premolar teeth.

Design

Recordings were made from 11 healthy teeth in 9 subjects (aged 16–30 years) using a laser Doppler flow meter (Periflux 4001) equipped with both red and infrared lasers. Average blood flow signals were obtained with both light sources alternately from each tooth under five conditions: intact tooth without opaque rubber dam, intact tooth with dam, after injecting local anaesthetic (3% Mepivacaine) (LA) over the apex of the tooth and cavity preparation to almost expose the pulp, after removal and replacement of the pulp, and with the root canal empty.

Results

With infrared light, the dam significantly decreased the mean blood flow by 80%. Injecting LA and cavity preparation had no significant effect. Removal and replacement of the pulp reduced the mean blood flow by 58%. There was no further change when the pulp was removed. With red light, the dam reduced the signal from intact teeth by 60%. Injecting LA and cavity preparation had no significant effect. The signal fell by 67% after pulp removal and replacement and did not change significantly when the pulp was removed.

Conclusions

Opaque rubber dam minimises the contribution of non-pulpal tissues to the laser Doppler signal recorded from premolars. Using dam, the pulp contributed about 60% to the blood flow signal with both red and infrared light. The difference between them in this respect was not significant.     

A comparison of techniques for assessment of coronal dye leakage.

This study was designed to compare different techniques for coronal dye leakage testing. One hundred and fifty extracted human anterior teeth were fully instrumented and randomly divided into two experimental groups of 60 teeth each, plus two groups of 15 teeth each for positive and negative controls. One group was rinsed with 5.25% NaOCl (smear layer intact), whereas the other group was flushed with 17% EDTA and 5.25% NaOCl (smear layer removed). Roots were obturated with gutta-percha using lateral condensation and AH Plus as root canal sealer. Each experimental group was divided into three subgroups of 20 teeth each for three methods of testing coronal dye leakage: passive dye penetration, penetration with vacuum applied, and fluid filtration methods. The teeth were left in 100% humidity at 37 degrees C for 5 days before being immersed in Indian ink for 2 days and cleared. The linear extent of dye penetration was measured. Mean depth of leakage for the groups with the smear layer intact was 2.5 +/- 1.0 mm for passive dye penetration, 6.7 +/- 2.8 mm for vacuum dye penetration, and 3.0 +/- 1.1 mm for fluid filtration dye penetration. In the group in which the smear layer was removed, the mean depths of leakage were: 3.2 +/- 2.1 mm for passive dye penetration, 5.8 +/- 2.8 mm for vacuum dye penetration, and 3.4 +/- 2.1 mm for fluid filtration. The vacuum method resulted in significantly (p < 0.05) more dye penetration than fluid filtration and passive dye penetration. The presence or absence of smear layer had no statistically significant effect (p > 0.05) on any of the leakage testing techniques.