Effect of clot removal on cerebrovascular contraction after subarachnoid hemorrhage in the monkey: Pharmacological study

Summary Clot removal at early surgery has been reported to be clinically effective for the prevention of cerebral vasospasm following subarachnoid hemorrhage (SAH) due to rupture of an intracranial aneurysm. We examined the most efficacious timing of mechanical clot removal on pharmacological responses in a monkey SAH model. Cynomolgus monkeys (Macaca fascicularis) were randomized into five groups: sham-operated, clot removal in which the clot was removed 48, 72, or 96h after SAH, and clot groups. An autologous blood clot was placed around the bilateral major cerebral arteries after craniectomy to mimic the hemorrhage. Seven days after the SAH, proximal and successively distal parts of the middle cerebral arteries were cut into rings for isometric tension measurement. The contractile responses to potassium chloride, 5-hydroxytryptamine, norepinephrine, adenosine triphosphate, prostaglandin F₂, and hemoglobin were greater in the proximal parts than in the distal parts in each group. Compared with the sham-operated group, the responses of the clot-removal and clot groups to the drugs were progressively attenuated. The maximum responses to 5-hydroxytryptamine in the proximal parts and to adenosine triphosphate in the distal parts started to decrease, significantly, in the clot-removal group 48h after SAH, while most of the responses to the other agonists began to decrease in the clot-removal groups later than 72h after SAH. These results suggest that the attenuation of cerebrovascular contractile responses 7 days after SAH is pharmacologically inevitable, even if the clot is removed as early as 48h after the SAH. Clot removal may thus be recommended within 48h after SAH to ameliorate the severity of cerebral vasospasm following SAH.     

Endovascular Treatment for Lower Extremity Deep Vein Thrombosis: An Overview

Lower extremity deep vein thrombosis (DVT) is a serious medical condition that can result in local pain and gait disturbance. DVT progression can also lead to death or major disability as a result of pulmonary embolism, postthrombotic syndrome, or limb amputation. However, early thrombus removal can rapidly relieve symptoms and prevent disease progression. Various endovascular procedures have been developed in the recent years to treat DVT, and endovascular treatment has been established as one of the major therapeutic methods to treat lower extremity DVT. However, the treatment of lower extremity DVT varies according to the disease duration, location of affected vessels, and the presence of symptoms. This article reviews and discusses effective endovascular treatment methods for lower extremity DVT.     

Substantial regional differences in the biomechanical behavior of molar treated with selective caries tissue removal technique: a finite element study

ObjectivesSelective caries removal (SCR) is recommended over non-selective removal for managing deep carious lesions to avoid pulp exposure and maintain pulp vitality. During SCR, residual carious dentin is left behind and sealed beneath the restoration. The biomechanical effects of such residual lesions on the restored tooth remain unclear and were assessed using finite element modeling (FEM).MethodsBased on μ-CT images of a healthy permanent human third molar, we developed five finite element models. Generic class I and II cavity restorations were modeled where residual lesions of variable sizes were either left or fully removed on occlusal and proximal surfaces. The cavities were restored with adhesive composite. All 3D-FE models were compared with a model of a healthy, non-treated molar. A vertical load of 100 N was applied onto the occlusal surface.ResultsRegardless of the lesion size, in molars with occlusal lesions higher mean stresses were predicted along the filling-lesion interface than in all other models. The smallest occlusal lesion (Ø₁ = 1 mm) resulted in the highest maximum stresses at the filling-lesion interface with large stress concentrations at the filling walls indicating failure risk. In conclusion, lesion site and extent are influencing parameters affecting the filling-lesion interactions and thus the biomechanical behavior of the tooth after SCR.SignificanceRetaining carious lesions around the pulpal floor affects the deformation and stress states in tooth-filling complexes. The higher stresses observed in molars with occlusal lesions may affect restoration stability and longevity. Suprisingly, more extended occlusal lesions may provide a more favorable tooth performance than less extended ones. In contrast, in molars with proximal lesions the residual lesion had only limited effect on the tooth’s biomechanical condition.     

Cell surface engineering of microorganisms towards adsorption of heavy metals

Abstract

Heavy metal contamination has become a worldwide environmental concern due to its toxicity, non-degradability and food-chain bioaccumulation. Conventional physical and chemical treatment methods for heavy metal removal have disadvantages such as cost-intensiveness, incomplete removal, secondary pollution and the lack of metal specificity. Microbial biomass-based biosorption is one of the approaches gaining increasing attention because it is effective, cheap, and environmental friendly and can work well at low concentrations. To enhance the adsorption properties of microbial cells to heavy metal ions, the cell surface display of various metal-binding proteins/peptides have been performed using a cell surface engineering approach. The surface engineering of Gram-negative bacteria, Gram-positive bacteria and yeast towards the adsorption of heavy metals are reviewed in this article. The problems and future perspectives of this technology are discussed.     

Minimally invasive removal of a deep-positioned cannulated screw from the femoral neck: A case report

BACKGROUNDClinical femoral neck fracture is common. Based on patient age and fracture type, different surgical methods can be selected, including cannulated screw fixation of the femoral neck and artificial total hip joint or semi-hip joint replacement. When patients with femoral neck fracture are treated with cannulated screw fixation, a cannulated screw may be positioned too deep. The excessively deep-placed screw is difficult to remove and causes major trauma to the patient.CASE SUMMARYA patient with poliomyelitis and femoral neck fracture was treated with a cannulated screw that was placed too deep. A self-made auxiliary tool (made of a steel sternal wire) was used to remove the cannulated screw near the pelvic cavity.CONCLUSIONThe depth of the cannulated screw can be estimated before screw placement using an improved hollow screwdriver with a scale mark, thus improving the safety of screw placement and facilitating clinical use.     

Optimisation of a guided endodontics protocol for removal of fibre‐reinforced posts

This paper demonstrates the usefulness of endodontic guides for the removal of fibre posts. A 36‐year‐old man consulted for retreatment of a maxillary first molar presenting a periapical pathology. This tooth revealed a composite reconstruction together with a glass‐fibre post in the palatal root canal. To assist removal, use of an endodontic 3D‐printed guide was indicated. A cone beam computed tomography examination and an optical impression were made to produce a tooth‐supported guide by means of implant planning software (Blue Sky Plan, Blue Sky Bio^®). The software enabled definition of a drilling pathway, which was transferred clinically using a resin template together with a sleeve and a 0.75‐mm drill. The drill was guided as far as the gutta‐percha situated in the apical third, limiting any risk of impairment or perforation.     

PDR患者二期行硅油取出联合白内障手术的临床观察

目的探讨增殖性糖尿病视网膜病变(PDR)二期患者硅油填充术后行硅油取出联合白内障手术的临床疗效。方法回顾性分析2008—2012年于我院行硅油取出联合白内障超声乳化、人工晶体植入术的PDR患者55例(61眼),术后视力恢复情况。结果术后1个月最佳矫正视力好于术前最佳矫正视力的40眼(74.07%),与术前相同的10眼(18.52%),低于术前最佳矫正视力的4眼(7.41%)。所有患者均无角膜内皮失代偿、人工晶体移位、复发性视网膜脱离等并发症发生。结论 PDR行玻璃体切除术后合并白内障的患者,取出硅油时联合白内障超声乳化、人工晶体植入术是经济、安全、有效的治疗方法。     

Rapid,high‐fluence multi‐pass q‐switched laser treatment of tattoos with a transparent perfluorodecalin‐infused patch: A pilot study

Background and Objectives

Perfluorodecalin (PFD) has previously been shown to rapidly dissipate the opaque, white micro‐bubble layer formed after exposure of tattoos to Q‐switched lasers [1]. The current pilot study was conducted to qualitatively determine if the use of a transparent PFD‐infused silicone patch would result in more rapid clearance of tattoos than conventional through‐air techniques.

Materials and Methods

Black or dark blue tattoos were divided into two halves in a single‐site IRB‐approved study with 17 subjects with Fitzpatrick skin types I–III. One half of each tattoo served as its own control and was treated with one pass of a standard Q‐switched Alexandrite laser (755 nm). The other half of the tattoo was treated directly through a transparent perfluorodecalin (PFD) infused patch (ON Light Sciences, Dublin, CA). The rapid whitening reduction effect of the Patch routinely allowed three to four laser passes in a total of approximately 5 minutes. Both sides were treated at highest tolerated fluence, but the optical clearing, index‐matching, and epidermal protection properties of the PFD Patch allowed significantly higher fluence compared to the control side. Standard photographs were taken at baseline, immediately prior to treatment with the PFD Patch in place, and finally before and after each treatment session. Treatments were administered at 4‐ to 6‐week intervals.

Results

In a majority of subjects (11 of 17), tattoos treated through a transparent PFD‐infused patch showed more rapid tattoo clearance with higher patient and clinician satisfaction than conventional treatment. In no case did the control side fade faster than the PFD Patch side. No unanticipated adverse events were observed.

Conclusions

Rapid multi‐pass treatment of tattoos with highest tolerated fluence facilitated by a transparent PFD‐infused patch clears tattoos more rapidly than conventional methods. Lasers Surg. Med. 47:613–618, 2015. © 2015 The Authors. Lasers in Surgery and Medicine published by Wiley Periodicals, Inc.