Colour stability of resin infiltrated white spot lesion after exposure to stain-causing drinks

BackgroundThe resin-based materials are used extensively in esthetic restorations but are.prone to color changes over time.AimsTo assess the discoloration effect of red tea, Arabic coffee, and black coffee on the resin infiltrated white spot lesions (WSL). Moreover, to investigate the impact of time (1d, 3d, and 7d) on the discoloration of the resin infiltrated WSLs.Materials and methodsThirty-three extracted human premolar teeth were used to create WSLs, and ICON resin infiltration treatment was performed to obliterate the enamel pores. Teeth with resin infiltrated WSLs were sectioned into two halves by cutting mesio-distally and cross-sectionally at 1 mm below the CEJ. The resin infiltrated specimens was exposed to control (artificial saliva) and staining subgroups. Colour stability was assessed using the CIE L*a*b* system.ResultsAnalysis of variance (p < 0.05) and Tukey’s multiple comparison tests revealed an insignificant color change in the control group. The immersion of resin infiltrated specimens at time intervals of 1 d (p < 0.001), 3 d (p < 0.001), and 7 d (p < 0.001) showed significant differences in color change.ConclusionResin infiltrated WSLs showed marked color changes after exposure to red tea, black coffee, and Arabic coffee over time. Severe discoloration of the infiltrant was evident with the use of red tea compared to black coffee and Arabic coffee. This suggests that ICON resin-based composite material might not be a suitable material for WSL infiltration.     

Effect of Silver Diamine Fluoride on Reducing Candida albicans Adhesion on Dentine

Background

Candida albicans is the most frequent pathogenic fungus in oral cavities. It adheres to dental tissues as part of dental plaques and contributes to caries formation.

Objectives

To evaluate the effect of silver diamine fluoride (SDF) on reducing C. albicans adhesion on dentine surfaces.

Methods

Flat dentine surfaces were prepared from bovine dental disks, and samples were divided into three groups. The first and second groups were pretreated for 3 min with 299 mM or 2.99 M SDF, respectively, and the third group (control) did not undergo any SDF pretreatment. All samples were washed, inoculated with C. albicans suspension onto their dentine surface, incubated at 30 °C for 6 h, and washed again to remove any nonadherent cells. The abundance of adherent cells was investigated using colorimetric and real-time polymerase chain reaction approaches. Subsequently, the morphological changes in C. albicans by pretreatment with SDF were observed under a scanning electron microscope (SEM).

Results

SDF inhibited candidal growth at concentrations as low as 2.99 µM. Dentine disks pretreated with 299 mM or 2.99 M SDF displayed significantly fewer adhered cells as compared with the control group. Upon pretreatment with SDF, SEM images showed severe morphological changes in the cellular walls, in a dose-dependent manner, suggesting a fungicidal effect of SDF against the yeast.

Conclusion

SDF should be considered for clinical applications aimed at inhibiting dental plaque caused by C. albicans, particularly in children and elderly individuals.

     

Tooth implantation and replacement in Sauropterygia

Tooth replacement and implantation of Sauropterygia is described with special reference to the generaPlacodus andNothosaurus. Tooth replacement is horizontal, with the exception of the enlarged crushing tooth plates on the maxilla, palatine, and dentary ofPlacodus (placodonts), which are replaced vertically. Tooth implantation is thecodont, with variable ankylosis of the base of the root. Sauropterygia is unique compared to other reptiles in that replacement teeth are “alveolarized.” The alveolarization of replacement teeth adds to the evidence supporting of a monophyletic Sauropterygia (Placodontia plus Eosauropterygia).      

Gibberellins and <Emphasis Type="Italic">N</Emphasis>-(2-chloro-4-pyridyl)-<Emphasis Type="Italic">N′</Emphasis>-phenylurea improve retention force and reduce water core in pre-mature fruit of Japanese pear cv. Housui

A study of the effect of a gibberellin A₃ + A₄ mixture (GAs) on pre-harvest fruit drop of Japanese pear cv. Housui is reported. The GAs was applied alone or in combination with N-(2-Chloro-4-pyridyl)-N′-phenylurea (CPPU) in a lanolin paste to the abscission zone at the spur-end of the pedicel. The results showed that the GAs and CPPU combination treatment increased the pedicel–spur retention force relative to that of the untreated controls. Histological studies showed an accelerated rate of cambium division and the development of secondary xylem in the abscission zone near the spur-end of pedicels treated with the GAs plus CPPU paste, which delayed the formation of the abscission zone. Fruit quality (sugar, acid, firmness, color) was not adversely affected by the application of GAs plus CPPU, although the application of GAs alone promoted ripening. In contrast, the addition of CPPU to the two GAs delayed fruit ripening, which was measured as ethylene efflux. All treatments were without adverse effects on return bloom, measured as bud size. The CPPU plus GAs treatment also suppressed the incidence of water core, whereas the application of the GAs alone accelerated water core in this water core susceptible pear variety.     

氧化锆全瓷修复与金属烤瓷修复在前牙牙冠延长术后冠修复中的应用效果比较

目的:比较氧化锆全瓷修复与金属烤瓷修复在前牙牙冠延长术后冠修复中的应用效果及安全性。方法:选取2016年7月~2018年7月我院收治的择期行前牙牙冠延长术后冠修复的患者80例(共97颗上颌牙),采用随机数字表法将患者分为两组,对照组40例(48颗患牙)采用金属烤瓷修复,观察组40例(49颗患牙)采用氧化锆全瓷修复。比较两组患者的牙体修复效果和牙周修复效果,治疗前后龈沟出血指数(sulcus bleeding index,SBI)、松动度(movable degree,MD)和菌斑指数(plaque index,PI)的变化以及不良反应的发生情况。结果:治疗后,观察组临床治疗总有效率显著高于对照组(87.76%vs.70.83%,P<0.05);观察组患者的边缘密合度、牙体折损、牙体颜色和牙龈健康状况均显著优于对照组(P<0.05);两组患者治疗后的SBI、MD和PI均较治疗前显著下降,且观察组以上指标显著低于对照组(P<0.05)。观察组患者不良反应发生率显著低于对照组(P<0.05)。结论:氧化锆全瓷修复用于前牙牙冠延长术后冠修复的临床效果显著优于金属烤瓷修复,且安全性更高。     

纤维桩、纳米复合树脂结合氧化锆烤瓷冠对根管治疗后后牙楔状缺损患者美学效果及牙周组织的影响

摘要 目的：探讨纤维桩、纳米复合树脂结合氧化锆烤瓷冠对根管治疗后后牙楔状缺损患者美学效果及牙周组织的影响。方法：选取2018年1月至2019年3月期间我院收治的103例患者作为研究对象,按修复材料的不同分为对照组（n=52,患牙62颗）和研究组（n=51,患牙63颗）。对照组给予金属桩核、金属烤瓷冠修复,研究组给予纤维桩、纳米复合树脂结合氧化锆烤瓷冠修复。修复1年后,评价两组的修复成功率和修复效果。比较两组修复前及修复后1年的牙龈指数、菌斑指数、牙周探诊深度、龈沟液量及龈沟液中碱性磷酸酶（ALP）、天门冬氨酸转氨酶（AST）水平。结果：研究组的修复成功率比对照组高（P<0.05）。研究组修复体的表面光滑率、边缘密合性、固定良好率及颜色匹配率均明显高于对照组（P<0.05）。两组治疗后牙龈指数、菌斑指数及牙周探诊深度均明显低于治疗前（P<0.05）,龈沟液量及龈沟液中ALP、AST水平均明显低于治疗前（P<0.05）,同时研究组治疗后牙龈指数、菌斑指数及牙周探诊深度均低于对照组（P<0.05）,但两组治疗后龈沟液量及龈沟液中ALP、AST水平比较无差异（P>0.05）。结论：纤维桩、纳米复合树脂结合氧化锆烤瓷冠对根管治疗后后牙楔状缺损的修复成功率高,修复后美学效果佳,对牙周组织影响小。     

双线排龈法在烤瓷冠修复牙体缺损中的临床应用

目的:探讨双线排龈法在烤瓷冠修复牙体缺损中的临床应用效果,为临床提供参考。方法:选择2014年3月至2016年3月来我院拟行烤瓷冠修复的96例患者,按照患者入院顺序交替分为观察组和对照组,每组48例。观察组48例(56颗牙)采用双线排龈法,对照组48例(52颗牙)采用单线排龈法,观察和比较两组的排龈效果及随访24周的基牙与游离龈是否完全排开,龈沟宽度是否合适,牙体预备后肩台的边缘是否清晰、连续,印模肩台是否清晰、连续,有无气泡,模型是否清晰、光滑,牙龈有无渗血等。结果:观察组基牙与游离龈排开不全、印模肩台不清晰不连续或有气泡、模型不清晰不光滑、牙龈渗血的发生率均显著低于对照组(P0.05)。修复后24周,两组的修复体边缘隐蔽性比较差异无统计学意义(P0.05),观察组0级牙数为52颗(92.9%),对照组0级牙数为41(80.8%),观察组的牙周组织情况明显优于对照组(P0.05)。结论:在前牙烤瓷冠修复中应用双线排龈法的排龈效果较单线排龈法更好。     

A Single-Center Open-Label Study To Investigate The Efficacy And Safety Of Repeated Subcutaneous Injections Of Lanreotide Autogel In Patients With Acromegaly Previously Treated With Octreotide

ObjectiveTo evaluate the efficacy of lanreotide Autogel, a depot preparation of a long-acting somatostatin analogue, in patients with acromegaly who were previously treated with octreotide.MethodsIn a prospective single-center, open-label, comparative study, 13 patients were switched from octreotide treatment (baseline) to lanreotide Autogel therapy at a fixed dosage of 90 mg/4 wk. After 6 injections, the dosage was titrated to 60, 90, or 120 mg/4 wk, on the basis of growth hormone (GH) levels, for a further 6 injections. Mean GH and insulinlike growth factor-I (IGF-I) levels were determined at baseline, during treatment (to 48 weeks), and up to 8 weeks after the last injection.ResultsThere was no significant change in the proportion of patients with GH and IGF-I control from baseline to week 48 (GH, 85% to 89%; IGF-I, 46% to 62%). Mean GH levels changed little from baseline, but mean IGF-I levels were significantly lower after 32 weeks (P < .05) and 48 weeks (P < .02). Data collected at 6 and 8 weeks after the last injection suggested that the efficacy of lanreotide Autogel can persist for longer than 4 weeks.ConclusionThis small study suggests that lanreotide Autogel is at least as effective as octreotide in the control of acromegaly and may last for longer than the recommended 4 weeks. It appears to be a useful alternative to long-acting octreotide in the treatment of acromegaly. (Endocr Pract. 2010;16:191-197)     

Photolytic discoloration of azo dye incorporated organoiron polymer

Organoiron polymers with azo dyes pendant to the backbone incurred loss of color upon irradiation with UV light (λ = 300 nm) in acetonitrile solution. The loss of color is attributed to the interaction of the cleaved iron moiety with the azo chromophore. Similarly, addition of small amounts (⩽1 mM) of both Fe(II) and Fe(III) to the organic polymer analogue yielded comparable discoloration rates upon irradiation. The iron cation forms a complex with the azo chromophore group in the polymer, and subsequently leads to the photodegradation of the azo dye. At higher initial polymer concentrations, minimal discoloration was observed due to the light attenuation effect of the deeply colored solutions. In the presence of small amounts of water, the iron cation is inhibited from partaking in complex formation and no polymer discoloration was observed. For the organic polymer analogue, the presence of water did not show significant change over its absence upon irradiation. The discoloration of the polymer relies solely on its interaction with the iron cation present in solution, and does not require addition of any catalyst or reagent. This process might be developed into a pragmatic and viable method for the treatment of specifically designed colored materials using only UV light.     

Analgesic effect of total flavonoids from Sanguis draxonis on spared nerve injury rat model of neuropathic pain

BackgroundSanguis draxonis (SD) is a kind of red resin obtained from the wood of Dracaena cochinchinensis (Lour.) S. C. Chen (D. cochinchinensis). The active components of total flavonoids from SD (SDF) have analgesic effect.AimThe aim of this study is to evaluate the analgesic effects and potential mechanism of SDF on mechanical hypersensitivity induced by spared nerve injury (SNI) model of neuropathic pain in the rat.MethodsSNI model in rats was established and then the rats were treated with SDF intragastric administration for 14 days. Paw withdrawal mechanical threshold (PMWT) in response to mechanical stimulation was measured by von Frey filaments on day 1 before operation and days 1, 3, 5, 7, 9, 11, 14 after operation, respectively. After 14 days, we measured the levels of nitric oxide (NO), nitric oxide synthase (NOS), tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β) and interleukin-10 (IL-10) in the spinal dorsal horn. In addition, the expression of fibroblast growth factor receptor 3 (FGFR3), phosphorylated cyclic AMP response element-binding protein (p-CREB) and glial fibrillary acidic protein (GFAP) of the spinal dorsal horn was evaluated by western blotting and an immunofluorescence histochemical method, respectively.ResultsIntragastric administration of SDF (100, 200, 400 mg/kg) alleviated significantly SNI-induced mechanical hypersensitivity, as PMWT increased in a dose-dependent manner. Moreover, SDF not only reduced the level of NO, NOS, TNF-α and IL-1β, but also upregulated the level of IL-10 in the spinal dorsal horn of SNI rats. At the same time, SDF (100, 200, 400 mg/kg) could inhibit the expression of FGFR3, GFAP and p-CREB in the spinal dorsal horn.ConclusionSDF has potentially reduced mechanical hypersensitivity induced by SNI model of neuropathic pain which may be attributed to inhibition of astrocytic function (like release pro-inflammatory cytokines) and NO release as well as p-CREB activation in the spinal dorsal horn.     

Frequent Monitoring of Blood Glucose Levels via a Remote Patient Monitoring System Helps Improve Glycemic Control

ObjectiveThis study aimed to evaluate the effectiveness of the Vivovitals diabetes platform in improving glycemic control and reducing hemoglobin A1c (HbA1c) levels in patients with uncontrolled type 2 diabetes mellitus by providing more accessible and direct patient care under the monitoring and oversight of their physician.MethodsThis 12-week, prospective, pragmatic, single-center, double-arm study assessed the impact of the Vivovitals diabetes platform on glycemic control in 78 adults aged ≥18 years with HbA1c levels of ≥7.5% (58 mmol/mol) at baseline. The participants were randomized into 2 groups. The control group received usual clinical care, whereas the intervention group was provided with a smartphone-linked telehealth application, a preconfigured glucometer, and access to a glycemic reading diary. The blood glucose levels of the intervention group were transmitted to the providers daily. Patients whose blood glucose level was <70 mg/dL or >180mg/dL were contacted, and modifications were made to their diet and medication. The 2 groups were compared at the baseline and at 12 weeks using nonparametric tests, with P <.05 considered statistically significant.ResultsOver 12 weeks, the average HbA1c level in the control group reduced by 0.474% (P = .533; 95% CI, −0.425 to −0.523), whereas the average HbA1c level in the intervention group reduced by 1.70% (P = .002; 95% CI, −1.02 to −2.39). The estimated treatment difference was expressed using Cohen d, which yielded 0.62. After 12 weeks, the HbA1c values between the control and intervention groups were statistically significant (P = .001).ConclusionThe use of the Vivovitals platform may help to improve glycemic control among individuals with type 2 diabetes mellitus.     

Effect of Bromocriptine-Qr On Glycemic Control in Subjects with Uncontrolled Hyperglycemia On One or Two Oral Anti-Diabetes Agents

ObjectiveTo investigate the effect of Bromocriptine QR on glycemic control in patients with type 2 diabetes whose glycemia is poorly controlled on one or two oral anti-diabetes agents.MethodsFive hundred fifteen Type 2 Diabetes Mellitus (T2DM) subjects (ages 18 to 80 and average body mass index [BMI] of 32.7) with baseline HbA1c ≥ 7.5 and on one or two oral anti-diabetes (OAD) medications (metformin, sulfonylurea, and/or thiazolidinediones) were randomized 2:1 to bromocriptine-QR (1.6 to 4.8 mg/day) or placebo for a 24 week treatment period. Study investigators were allowed to adjust, if necessary, subject anti diabetes medications during the study to attempt to achieve glycemic control in case of glycemic deterioration. The impact of bromocriptine-QR treatment intervention on glycemic control was assessed in subjects on any one or two OADs (ALL treatment category) (N = 515), or on metformin with or without another OAD (Met/OAD treatment category) (N = 356), or on metformin plus a sulfonylurea (Met/SU treatment category) (N = 245) 1) by examining the between group difference in change from baseline a) concomitant OAD medication changes during the study, and b) HbA1c and 2) by determining the odds of reaching HbA1c of ≤ 7.0% on bromocriptine-QR versus placebo.ResultsSignificantly more patients (approximately 1.5 to 2-fold more; P < .05) intensified concomitant anti diabetes medication therapy during the study in the placebo versus the bromocriptine-QR arm. In subjects that did not change the intensity of the baseline diabetes therapy (72%), and that were on any one or two OADs (ALL), or on metformin with or without another OAD (Met/OAD), or on metformin plus sulfonylurea (Met/SU), the HbA1c change for bromocriptine-QR versus placebo was − 0.47 versus + 0.22 (between group delta of − 0.69, P < .0001), − 0.55 versus + 0.26 (between group delta of − 0.81, P < .0001) and − 0.63 versus + 0.20 (between group delta of − 0.83, P < .0001) respectively, after 24 weeks on therapy. The odds ratio of reaching HbA1c of ≤ 7.0% was 6.50, 12.03 and 11.45 (P < .0002) for these three groups, respectively.ConclusionIn T2DM subjects whose hyperglycemia is poorly controlled on one or two oral agents, bromocrip tine-QR therapy for 24 weeks can provide significant added improvement in glycemic control relative to adding placebo. (Endocr Pract. 2012;18:931-943)     

Human tooth development,tooth length and eruption; a study of British archaeological dentitions

Abstract

Human teeth erupt during root growth but few studies report the relationship between fractions of root development and eruption levels. The aim of this study was to assess root stages of deciduous and early erupting permanent teeth (maxillary and mandibular central incisors and first molars) at eruption levels and relate this to root fraction and tooth length. The sample consisted of 620 modern human skeletal remains with developing teeth. Tooth stage (based on Moorrees crown and root stages) and eruption levels of all developing teeth were assessed where possible. Tooth length of isolated teeth was measured. The distribution of root stage at eruption levels was calculated. Results showed that root stage at alveolar eruption was less variable than at partial eruption. Most teeth (72% of 138) at alveolar eruption were at root a quarter (R¼) whereas teeth at partial eruption were at R¼ or root half (R½) (38 and 50% of 128 respectively). These findings suggest that the active phase of eruption is probably a rapid process and occurs during the first half of root growth.     

Initial Combination Therapy with Metformin and Colesevelam for Achievement of Glycemic and Lipid Goals Min Early Type 2 Diabetes

ObjectiveTo evaluate the efficacy and safety of initial combination therapy with metformin plus colesevelam in patients with early type 2 diabetes.MethodsIn this 16-week, randomized, double-blind, placebo-controlled study, adults with type 2 diabetes (hemoglobin A1c [A1C] values of 6.5% to 10.0%) and hypercholesterolemia (low-density lipoprotein cholesterol [LDL-C] levels ≥ 100 mg/dL) were randomly assigned (1:1) to colesevelam (3.75 g/d) or placebo in combination with open-label metformin (850 mg/d; uptitrated at week 2 to 1, 700 mg/d). The primary efficacy evaluation was change in A1C from baseline to study end (week 16 with last observation carried forward).ResultsIn total, 286 patients were randomized: metformin/colesevelam (n = 145) or metformin/placebo (n = 141). Mean A1C was reduced by 1.1% with metformin/ colesevelam (from 7.8% at baseline to 6.6% at study end) and by 0.8% with metformin/placebo (from 7.5% to 6.7%), resulting in a treatment difference of -0.3% at study end (P = .0035). In addition, metformin/colesevelam significantly reduced LDL-C (-16.3%), total cholesterol (-6.1%), non-high-density lipoprotein cholesterol (-8.3%), apolipoprotein B (-8.0%), and high-sensitivity C-reactive protein (-17%) and increased apolipoprotein A-I (+ 4.4%) and triglycerides (+ 18.6%) versus metformin/placebo (P < .01 for all). The proportions of patients who achieved recommended goals with metformin/colesevelam versus metformin/placebo, respectively, were as follows: A1C < 7.0% (67% versus 56% [P = .0092]), LDL-C < 100 mg/dL (48% versus 18% [P < .0001]), and composite A1C < 7.0% + LDL-C < 100 mg/dL (40% versus 12% [P < .0001]). Safety and tolerability were similar between the treatment groups.ConclusionMetformin plus colesevelam may be a valid option for initial therapy to achieve glycemic and lipid goals safely in early type 2 diabetes. (Endocr Pract. 2010;16:629-640)     

Sex-sorted bovine spermatozoa and DNA damage: I. Static features

This study examined the static response of Spermatozoa DNA Fragmentation (SDF) after sex selection in bulls using a MoFlo^® SX (Beckman Coulter, Miami FL) spermatozoa sorter to produce three different subpopulations: 1) Spermatozoa bearing X- chromosomes with a purity of 95%, 2) Spermatozoa bearing Y-chromosomes with a purity of 95%, and 3) non-viable spermatozoa. The static response of SDF refers to the baseline values observed for DNA damage when analyzed pre- and post sex-sorting. Results showed that while the baseline level SDF in pre-sorted bull spermatozoa samples ranged from 5.3% to 11% with an average of 7.9% ± 2.1%, the level of SDF obtained in X- and Y-chromosome sorted samples was much lower (3.1% ± 1.9%) and statistical differences were obtained after comparing both groups (P < 0.01). Spermatozoa containing a fragmented DNA molecule tend to be accumulated in the non-viable subpopulation. The baseline SDF level in X- and Y-chromosome sorted subpopulations is reduced, by 63% on average when compared to the values obtained in the neat semen sample. Different bulls exhibit unique SDF reduction efficiencies via the X- and Y-chromosome sex selection process.     

Distinguishing the effects of vegetation restoration on runoff and sediment generation on simulated rainfall on the hillslopes of the loess plateau of China

Aims

Since the 1970s, extensive croplands were converted to forest and pasture lands to control severe soil erosion on the Loess Plateau of China. We quantify the direct and indirect effects of vegetation restoration on runoff and sediment yield on hillslopes in the field to improve environmental governance.

Methods

An artificial rainfall experiment at a rainfall intensity of 120 mm h⁻¹ and a slope gradient of 22° were used to distinguish the effects of vegetation restoration on runoff and sediment yield.

Results

Compared to the farmland slopes, vegetation restoration directly prolonged the time-to-runoff by 140%, reduced the runoff rate by 20%, and increased the soil infiltration capacity by 15%. Vegetation restoration indirectly delayed the time-to-runoff by 120%, reduced the runoff rate and sediment yield rate by 50% and 94%, respectively, and increased the soil infiltration capacity by 58% on the hillslopes with vegetation restoration.

Conclusions

The direct effects of vegetation restoration on runoff and sediment yield were lower than its indirect impacts. Vegetation cover, decreases in soil bulk density, and increases in belowground root biomasses and > 0.25 mm aggregate stability were the primary causes of runoff and sediment yield reduction on the slopes with vegetation restoration.

     

Supervised exercise with or without laser-guided feedback for people with non-specific chronic low back pain. A randomized controlled clinical trial

BackgroundAmong the most effective therapeutic interventions in non-specific chronic low back pain (NSCLBP), clinical practice guidelines highlight exercise therapy and patient education; However, regarding the combined intervention of exercise and Pain Neuroscience Education (PNE), there is no consensus on the most effective form of exercise.ObjetiveTo find out what changes occurred after the application of two exercise modalities [Supervised Exercise (SE) and Laser-Guided Exercise (LGE)] and PNE on pain, pain pressure thresholds, disability, catastrophizing, kinesiophobia and lumbar proprioception in subjects with NSCLBP.MethodsSingle-blind randomized clinical controlled trial. 60 subjects with NSCLBP. Both groups performed a a total of 16 therapeutic exercise sessions and 8 Pain Neuroscience Education sessions. With the Laser-Guided Exercise Therapy group performing laser-guided exercises.ResultsA significant decrease was observed for pain intensity for both groups between baseline and post-intervention and the 3 month follow-up (p < 0.001). There was a significant between-group difference between baseline and post-intervention scores in terms of pain intensity and kinesiophobia in favour of the LGE group.ConclusionSupervised exercise with or without laser feedback, when combined with PNE, reduces pain intensity, disability, pain catastrophizing, kinesiophobia and improves proprioception and PPTs in patients with NSCLBP. At a 3-month follow-up, the combination of LGE plus PNE is most effective for reducing pain intensity.     

Radiosterilization of Fluoroquinolones and Cephalosporins: Assessment of Radiation Damage on Antibiotics by Changes in Optical Property and Colorimetric Parameters

A most common problem encountered in radiosterilization of solid drugs is discoloration or yellowing. By pharmacopoeia method, discoloration can be assessed by measuring absorbance of solutions of irradiated solid samples at 450 nm. We propose to evaluate discoloration of solid samples directly by recording their diffuse reflectance spectra. Further, the reflectance spectrum is used to compute various color parameters: CIE XYZ tristimulus value, CIE Lab, (color difference), yellowness index (YI), dominant wavelength, and excitation purity by CIE method. The investigation of difference reflectance spectra and color parameters revealed that for fluoroquinolones, e-beam was more damaging than gamma radiation, whereas for cephalosporins, trend was reversed. The quantum of discoloration with gamma radiation and e-beam is found to be nearly equal when assessed by pharmacopeia method, and it is therefore inadequate to assess small color differences. The color parameters and ΔYI are found to be reliable indicators of discoloration. The tolerance limits proposed in terms of and ΔYI are ±2 and ±10 U, respectively. The dominant wavelength for all compounds has shifted to higher values indicating change in hue but defining color tolerance limit with this parameter requires adjunct excitation purity value.     

Extension of the breeding season and its effects on fertilization and development in two species of lugworm (Arenicola marina and A. defodiens)

In the autumn/winter breeding polychaetes, Arenicola marina and A. defodiens, spawning can be advanced or delayed by a number of months through temperature manipulation of the adults. However, this manipulation may have significant consequences for fertilization rates and embryo developmental success and so in vitro fertilizations were performed to assess the impact of manipulation. Firstly, we used oocytes and sperm obtained from advanced or delayed individuals. For both species, using gametes from 4 weeks advanced individuals did not result in a significant reduction in development, however, gametes from individuals advanced (A. marina only) or delayed by 8 weeks resulted in significantly fewer embryos developing normally. Reciprocal crosses of temperature-manipulated A. marina gametes (from 4 weeks advanced and 4 weeks delayed individuals) with those at the natural spawning time confirmed that the reduction in developmental success in both was attributable to the oocytes. After 5 h post-fertilization, the majority of oocytes from advanced individuals had fertilized, but by 24 h most were abnormal. For fertilizations with gametes from delayed individuals, nearly 100% of the embryos were developing normally after 24 h, but after 144 h significantly more were abnormal in crosses involving oocytes from delayed females. Although both species have reproductive plasticity to extend their breeding season, the significant reduction in the numbers of competent larvae produced as the spawning is delayed or advanced further may be a significant bottleneck in aquaculture and it may also have considerable implications for the long-term reproductive success of a population in response to environmental change.Sympatric populations of the species exist in many locations and the inherent variability in the breeding seasons could allow spawning times to overlap. Artificially delaying A. marina individuals enabled fertilizations to be performed with A. defodiens at the natural spawning time in the laboratory. Both conspecific fertilizations produced 100% trochophore larvae after 120 h, but A. defodiens oocytes failed to fertilize after incubation with A. marina sperm, in comparison to the A. marina oocytes incubated with A. defodiens sperm where 40% developed to the trochophore stage. This asymmetric gamete incompatibility may be one of a suite of mechanisms to minimise hybridisation.