A custom splint for zygomatic fractures

In the past, various materials have been applied to the zygomatic region to serve as a protective splint during the healing phase. Traditionally, these have been bulky, cumbersome, and non-conforming. This technique involves the application of a precut thermoplastic splint that is site-specific, lightweight, adjustable, low profile and universal and adapts to the anatomy of each patient.     

Resorbable internal splint: an adjunct to primary correction of unilateral cleft lip-nasal deformity

There is usually some relapse in position of the alar cartilage after primary repair of unilateral cleft lip. Therefore, preoperative or postoperative external splinting has been recommended to supplement either closed or open suspension of the alar cartilage. The authors present a method using a resorbable internal nostril splint to shield the positioned alar cartilage from deformational forces caused by scar, and thus avoiding the problems associated with external splinting. An internal nasal splint was placed in 15 infants during repair of unilateral complete cleft lip and nasal deformity. The nasal morphology was compared with that of 15 control patients who had the same nasolabial procedure without internal splinting. Average follow-up time was 20.4 months (range, 4 to 30 months). Photogrammetric analysis showed that asymmetry of the alar contours averaged 8.6 percent in the splinted patients, as compared with 23 percent for controls (p <0.01). Thus, alar asymmetry was decreased two-thirds in the splinted group. An internal resorbable nasal splint is an adjunct to open alar suspension in primary repair of the unilateral cleft lip nasal deformity. An internal nasal splint protects the corrected alar cartilage longer than an external splint and eliminates drawbacks, such as necrosis, cutaneous depression of the nostril sill, and patient noncompliance. This strategy of temporary internal support of healing cartilage has other applications.     

Time window analysis and sorting.

Flow cytometric hardware and procedures were developed to continuously analyse and to sort a particular time window in a kinetic response. The technique uses balanced air pressure to drive a stimulus-bead mixture from a vial to a t-junction where it mixes passively with cells. The t-junction is distanced from the flow cell and air pressure regulated so that the stimulation occurs at a fixed and adjustable time before the cells are interrogated by the laser beam. Practical applications of the device demonstrate utility with cells whose responses are seen in seconds or minutes. The device is easily implemented on any sorting flow cytometer.     

An apparatus for altering the mechanical load of the respiratory system

We describe an apparatus for altering the mechanical load against which the respiratory muscles operate in humans. A closed system incorporates a rolling seal spirometer. The spirometer piston shaft is coupled to a fast-responding linear actuator that develops force in proportion to desired command signals. The command signal may be flow (resistive loading or unloading), volume (elastic loading or unloading), constant voltage (continuous positive or negative pressure), or any external function. Combinations of loads can be applied. Logic circuits permit application of the load at specific times during the respiratory cycle, and the magnitude of the loads is continuously adjustable. Maximum pressure output is +/- 20 cmH2O. The apparatus permits loading or unloading over a range of ventilation extending from resting levels to those observed during high levels of exercise (over 100 l/min). In response to a square-wave input, pressure rises exponentially with a time constant of 20 ms.     

Eighty-four consecutive breast reconstructions using a textured silicone tissue expander.

Breast reconstruction utilizing smooth-surface silicone tissue expanders is associated with certain problems. Significant capsular contracture may develop around the expander with subsequent expander displacement necessitating repositioning or capsulectomy at the time of expander removal. Infection, pain on expansion, chest-wall compression, and complications related to the remote fill valve also have been reported. A textured-surface silicone expander with an integrated fill valve was developed to address these issues. Eighty-four consecutive breast reconstructions were performed by a single surgeon using textured expanders in 55 patients. Intraexpander pressures were measured during expansion for a group of these patients, and both initial and postinflation pressure readings were quite low (average initial pressure 2.88 mmHg; average postinflation pressure 12.87 mmHg). Eighty-one of the reconstructions have been completed without any expander losses and with minimal complications. Tissue expander volume averaged 580 cc, and the expansion duration averaged 5.6 months. Various types and configurations of permanent implants were used to complete the reconstructions. Eighty-four percent of our patients' completed reconstructions (including nippleareola reconstruction and opposite breast alteration, when necessary) were accomplished with just two procedures. Seventeen long-term adjustable textured-surface expander/implants with anatomic breast shape are still in place, all after only one operation. The inframmary fold has generally been established passively by the expansion process alone. Textured-surface silicone expanders have stayed where positioned, have expanded easily with minimal patient pain, and have created a noncontractile soft-tissue cover for the final implant. The textured expander with an integrated fill valve has simplified breast reconstruction by helping to limit the problems encountered with smooth silicone expanders. The resulting reconstructions have remained soft with a very acceptable aesthetic appearance. The patient office and hospital charts and photographs of this consecutive series were notarized and submitted to the Editor of this Journal, whose biostatistician randomly selected the cases illustrated.     

Effects of intraoral splint wear on proteoglycans in the temporomandibular joint disc

Intraoral splints are a common dental treatment for dysfunctions of the temporomandibular joint (TMJ), but their effects on the structures of the joint, specifically the disc, have not been well investigated. This study examined proteoglycans (PGs) of the TMJ disc of the miniature pig and tested for alterations resulting from intraoral splint wear. Sixteen female pigs were divided into three groups: control (C), control splint (CS), and protrusive splint (PS). Splinted groups received chrome-cobalt ramp splints which were worn continuously for 2 months. PG content within various disc locations was determined by colorimeteric assay. PG synthesis and type were examined by labeling with (35)S-sulfate and SDS-PAGE analysis. Average water content of the disc was 77.1%, which places it at the high end of the normal range for collagenous biomaterials (60-80%). PGs migrating to the positions typical of aggrecan, biglycan, and decorin on SDS-PAGE were present in all locations of all groups. The highest content and synthesis of PGs were always found in the intermediate band of the disc regardless of group (P < 0.05), supporting the notion that this band encounters heavy compressive loading during function. The joints of animals from both splinted groups showed a high frequency of gross pathology. Biglycan synthesis was increased in both splinted groups (P < 0.05). Newly synthesized biglycan had a shorter migration distance in the intermediate bands of the CS group, suggesting increased hydrodynamic size. These findings suggest that intraoral splint wear may cause disc damage or remodeling.     

The programmable implantable medication system (PIMS): design features and pre-clinical trials

This report describes the clinically significant design features of a variable rate implantable insulin infusion pump, the Programmable Implantable Medication System (PIMS), and its function in pre-clinical trials. PIMS has a number of unique features, including a solenoid, pulsatile pump design requiring minimal power (less than 15 microwatts) and a less-than-atmospheric pressure reservoir. Two-way communication is accomplished by radiotelemetry. The implanted device stores programs, and records its own hourly history of insulin delivery. Limits are set on total insulin delivery over time. Basal rates are adjustable, and patterned prandial insulin delivery curves can be programmed. Initial trials (3.1 dog-years) identified four problems which were corrected prior to final pre-clinical trials: microcracks in the diaphragm, a valve-seating leak, electronic failure of prototype microchips, and insulin aggregation. Sixteen dog-years of final pre-clinical trials with a single system design demonstrated that 5 pumps were still working continuously after up to 3.75 years (mean 3.3 years) without mechanical or electronic pump failure. The longest interval between reservoir refills was 5 months. Remaining potential causes of flow stoppage, however, include blockage of the peritoneal catheter by omentum (which occurred once), and air lock (which occurred two times).     

SOMPNN: an efficient non-parametric model for predicting transmembrane helices

Accurately predicting the transmembrane helices (TMH) in a helical membrane protein is an important but challenging task. Recent researches have demonstrated that statistics-based methods are promising routes to improve the TMH prediction accuracy. However, most of existing TMH predictors are parametric models and they have to make assumptions of several or even hundreds of adjustable parameters based on the underlying probability distribution, which is difficult when no a priori knowledge is available. Besides the performances of these parametric predictors significantly depend on the estimated parameters, some of them need to exploit the entire training dataset in the prediction stage, which will lead to low prediction efficiency and this problem will become even worse when dealing with large-scale dataset. In this paper, we propose a novel SOMPNN model for prediction of TMH that features by minimal parameter assumptions requirement and high computational efficiency. In the SOMPNN model, a self-organizing map (SOM) is used to adaptively learn the helices distribution knowledge hidden in the training data, and then a probabilistic neural network (PNN) is adopted to predict TMH segments based on the knowledge learned by SOM. Experimental results on two benchmark datasets show that the proposed SOMPNN outperforms most existing popular TMH predictors and is promising to be extended to deal with other complicated biological problems. The datasets and the source codes of SOMPNN are available at http://www.csbio.sjtu.edu.cn/bioinf/SOMPNN/.     

不同颌间牵引结合可吸收内固定材料在下颌骨骨折的重建研究

目的:下颌骨骨折患者采用可吸收内固定材料进行固定,同时结合牙弓夹板或自攻钛钉进行术后颌间牵引固定,探讨两种牵引方式对患者口腔情况和术后咬合关系恢复的促进作用。方法:对65例下颌骨骨折病例在完成骨折坚固内固定的基础上分别应用牙弓夹板和自攻钛钉进行颌间牵引,14 d后拆除颌间牵引,术后3-6月进行复查,对患者术后及复查期间口腔情况和咬合关系进行评估,采用两组间t检验进行统计学分析。结果:所有35例患者伤口均一期愈合。两种技术相结合,即使全面部骨折和陈旧性骨折都获得了良好的疗效,不同颌间牵引结果显示采用自攻钛钉治疗更加简便,口腔卫生情况明显好于采用牙弓夹板的患者;复查显示两组患者咬合关系恢复理想,两者骨折愈合、张口度及咬合关系无明显差异。结论:采用可吸收材料进行颌骨固位是一种较先进的坚固内固定方法,颌间自攻钛钉是恢复及维持咬合关系较为理想的治疗方法,两者结合可以获得满意的效果,值得临床推广。     

The vacuum splint: an aid in emergency splinting of fractures

The vacuum splint has been shown to be a simple, safe and effective method of emergency splinting of fractured extremities. The splint is simply constructed from clear vinyl sheeting and contains 2-mm. expanded polystyrene balls. Evacuation of air causes the splint to become rigid, thereby providing stability and immobilization of the limb. The splint is radiolucent, containing no obstructive metal components that would interfere with the radiographic appearance of the injured limb. The ease of application of this splint makes it especially effective for the emergency splinting of fractures in children.     

THE PREOPERATIVE AND POSTOPERATIVE CARE OF ACUTE ARTERIAL OBSTRUCTION

Acute arterial obstruction may result not only from arterial injuries but also from thrombosis or embolism. The fate of the extremity is generally decided in the first few hours following the obstruction of the major artery. It is therefore essential that physicians should be able to recognize acute ischemia of the extremities and institute treatment which will prevent permanent damage and facilitate the reestablishment of normal circulation.Direct application of heat should be scrupulously avoided since the reduced blood flow is unable to supply increased metabolic demand. The extremity should be placed at or just below heart level so as to avoid both the ischemia of elevation and the edema of dependency. Pressure in the form of either encircling plaster or even compression bandages should be avoided and the extremity simply immobilized by a posterior splint. General supportive treatment is essential to maintain adequate pressure and composition of the arterial blood. In selected cases, agents to overcome vascular spasm or to prevent extension of intravascular thrombosis are indicated.     

Pressure-induced perturbation of ANS-apomyoglobin complex: frequency domain fluorescence studies on native and acidic compact states.

The pressure dependence of the flexibility of the 8-anilino-1-naphthalene sulfonate (ANS)-apomyoglobin complex was investigated in the range between atmospheric pressure and 2.4 kbar by frequency domain fluorometry. We examined two structural states: native and acidic compact. The conformational dynamics of the ANS-apomyoglobin complex were deduced by studying the emission decay of ANS, which can form a noncovalent complex with the apoprotein in both the native and the acidic compact forms. Because the free fluorophore has a very short lifetime (less than 75 ps), its contribution can be separated from the long-lived emission. The latter arises from ANS molecules bound to the protein and provides information on the structural and dynamic characteristics of the macromolecule. The fluorescence emission decay of the ANS-apomyoglobin complex at neutral pH has a broad fluorescence lifetime distribution (width at half-maximum = 4.1 ns). The small changes in the fluorescence distribution parameters that occur with changes in pressure indicate that the ANS-apomyoglobin complex at neutral pH holds its compactness even at 2.4 kbar. A small contraction of molecular volume has been detected at low pressure, followed by a slight swelling with an increase in flexibility at higher pressures. The heterogeneity of ANS fluorescence in the acidic compact state of apomyoglobin is even greater than that in the native form (distribution width = 10 ns); moreover, the acidic compact state appears more expanded and accessible to solvent molecules than the native state, as suggested by the distribution center, which is 11 ns for the former and 19 ns for the latter. The lifetime distribution center remains constant with increasing pressure, which suggests that no other binding site is formed at high pressure.     

Feasibility of outpatient management after intra-articular yttrium-90: comparison of two regimens.

In a study comparing two regimens of treatment after intra-articular irradiation of the knee with yttrium-90 one group of patients was allocated to bed rest for 48 hours in hospital and the other to mobilisation at home. Initially a Robert-Jones orthopaedic bandage was applied to the knee in all patients, serving as a semi-rigid splint, but as loss of isotope from the knee was appreciable in the mobilised patients, subsequent patients were sent home with the knee in a plaster-of-Paris cylinder. No difference in extra-articular spread or chromosomal damage was found between the patients sent home with their knee in a rigid splint and those treated by bed rest. Clinical outcome at three months was satisfactory in all three groups. These results show that rigid splinting is essential in reducing extra-articular spread of the isotope but that bed rest is not necessary. Increases in intra-articular pressure associated with quadriceps muscle activity combined with flexion of the knee may be the most important factor affecting extra-articular spread of isotope.     

A prospective study to assess the outcome of steroid injections and wrist splinting for the treatment of carpal tunnel syndrome

Surgery is the definitive treatment for carpal tunnel syndrome. Conservative treatments, such as wrist splinting and steroid injections, are also effective for the relief of carpal tunnel symptoms, but their use remains controversial because they only offer long-term relief in a minority of patients. A prospective study was performed to assess the role of steroid injections combined with wrist splinting for the management of carpal tunnel syndrome. A total of 73 patients with 99 affected hands were studied. Patients presenting with known medical causes or muscle wasting were excluded. Diagnosis was made clinically and electrodiagnostic studies were performed only when equivocal clinical signs were present. Each patient received up to three betamethasone injections into the carpal tunnel and wore a neutral-position wrist splint continuously for 9 weeks. After that period, symptomatic patients received an open carpal tunnel release, and those who remained asymptomatic were followed up regularly for at least 1 year. Patients who relapsed were scheduled for surgery. At a minimum follow-up of 1 year, seven patients (9.6 percent) with 10 affected hands (10.1 percent) remained asymptomatic. This group had a significantly shorter duration of symptoms (2.9 months versus 8.35 months; p = 0.039, Mann-Whitney test) and significantly less sensory change (40 percent versus 72 percent; p = 0.048, Fisher's exact test) at presentation when compared with the group who had surgery. It is concluded that steroid injections and wrist splinting are effective for relief of carpal tunnel syndrome symptoms but have a long-term effect in only 10 percent of patients. Symptom duration of less than 3 months and absence of sensory impairment at presentation were predictive of a lasting response to conservative treatment. It is suggested that selected patients (i.e., with no thenar wasting or obvious underlying cause) presenting with mild to moderate carpal tunnel syndrome receive either a single steroid injection or wear a wrist splint for 3 weeks. This will allow identification of the 10 percent of patients who respond well to conservative therapy and do not need surgery.     

The dynamics of Deschampsia cespitosa in response to grazing

The response of Deschampsia cespitosa to four different grazing regimes (continuously and rotationally grazed by sheep and continuously and rotationally grazed by cattle) was investigated in two regions in Norway. Grazing both by cattle and sheep reduces, to a certain extent, the cover of D. cespitosa , while trampling seems to benefit D. cespitosa , both in terms of distribution and cover, probably due to improved conditions for germination. These two effects are important to consider when restoring abandoned grasslands with D. cespitosa as a dominating species. If the target is to control the species, successful management will depend on an adequate grazing pressure on D. cespitosa at the start of the restoration. At the same time it is important to avoid exposed ground due to damage by trampling.     

COSMETIC RHINOPLASTY

Rhinoplasty is safe, relatively painless and, if patients are carefully selected, quite successful. Psychological and personal benefits amply justify the procedure.Frequent indications are feelings of social rejection or ridicule and racial discrimination. Psychoneurotic patients with severe complexes, however, are poor subjects for rhinoplasty and should not be operated upon. It is doubtful that rhinoplasty grossly changes the physiologic integrity of the nose.Psychological trauma to the patient during hospitalization is to be avoided, sedation properly gauged for each patient, and complete block anesthesia used to preserve the cough reflex. The operation is brief and a small splint is worn for a few days. Complications are rare.     

Cosmetic rhinoplasty

Rhinoplasty is safe, relatively painless and, if patients are carefully selected, quite successful. Psychological and personal benefits amply justify the procedure. Frequent indications are feelings of social rejection or ridicule and racial discrimination. Psychoneurotic patients with severe complexes, however, are poor subjects for rhinoplasty and should not be operated upon. It is doubtful that rhinoplasty grossly changes the physiologic integrity of the nose. Psychological trauma to the patient during hospitalization is to be avoided, sedation properly gauged for each patient, and complete block anesthesia used to preserve the cough reflex. The operation is brief and a small splint is worn for a few days. Complications are rare.     

Fixation of a human rib by an intramedullary telescoping splint anchored by bone cement

A novel concept for rib fixation is presented that involves the use of a bioresorbable polymer intramedullary telescoping splint. Bone cement is used to anchor each end of the splint inside the medullary canal on each side of the fracture site. In this manner, rib fixation is achieved without fixation device protrusion from the rib, making the splint completely intramedullary. Finite element analysis is used to demonstrate that such a splint/cement composite can preserve rib fixation subjected to cough-intensity force loadings. Computational fluid dynamics and porcine rib experiments were used to study the anchor formation process required to complete the fixation.     

A new dynamic lumbrical simulating splint for claw hand deformity

The claw hand deformity, resulting from low ulnar or combined low ulnar and median nerve palsy, is an incapacitating situation. The splint described herein reverses the clawing by substituting for the lumbricals and interossei. If started early, it not only prevents the permanent stiffness of fingers in the claw position, but also effectively restores function without hampering day to day work because it is a surface splint.     

New Turbidimetric Device for Measuring Cell Concentrations in Thick Microbial Suspensions

A photoelectric turbidimeter is described for use in measuring cell concentrations in thick suspensions. Its sample cuvette provides a path length continuously adjustable between 0.01 and 20.00 mm. By reducing the path length, it is possible to measure the optical density in thick cell suspensions without dilution. Moreover, the method described is rapid and simple, and only small amounts (less than 1 ml) of cell suspensions are required. The method is applicable to cell concentrations ranging up to 10⁹/ml for yeast.