Extensor Tendon Repair: Avoidance and Management of Complications.

Extensor tendon repair can be technically challenging and can lead to suboptimal outcomes and complications even if managed perfectly. This article describes the pertinent clinical anatomy of the extensor mechanism, reviews outcomes and complications following extensor tendon repair, and provides guidance on how to avoid and manage complications when they occur.

Evaluation and Treatment of Primary Spinal Epidural Lymphoma Presenting as Acute Myelopathy in a Young Adult: A Case Report.

CASE: Primary spinal epidural lymphoma (PSEL) presenting as myelopathy is extremely rare, particularly within young, healthy adults. This case report describes a 26-year-old man presenting with progressive thoracic myelopathy. Magnetic resonance imaging revealed spinal epidural masses spanning T5-T10 and T12-L2 with multilevel cord compression and edema. After evaluation, the patient underwent emergent posterior decompression to prevent progressive neurological decline. Histology was consistent with diffuse large B-cell lymphoma, germinal center type. At 3 months postoperatively, the patient regained full neurologic function. CONCLUSION: Although rare, PSELs should be considered in patients presenting with myelopathy to facilitate timely diagnosis and treatment.

High-resolution x-ray scattering from epitaxial thin films of Y/Nb on Al2O3.

During the 1990s, Roger Cowley had a strong interest in the crystal and magnetic structures of rare-earth superlattices as a means to understand the rich and exotic magnetic properties of the rare-earth metals. High-quality samples can be grown by molecular beam epitaxy on sapphire substrates by first depositing a thin epitaxial layer of niobium, then a layer of yttrium or lutetium as a seed. High-resolution x-ray scattering is an excellent probe to characterise the crystal quality and was used to study the structure of the niobium layer. However, relatively little attention was paid to the seed layer. This article summarises some of the x-ray experiments performed by the Cowley group to study the structure of epitaxial [Formula: see text] niobium on [Formula: see text] sapphire, and extends the work to report some results on the structure of thin [Formula: see text] yttrium seed layers. The structure of the yttrium films is shown to have a strong dependence on the thickness of the niobium buffer, with the buffer needing to be thicker than a critical value of ∼80 [Formula: see text] for the formation of misfit dislocations at the Nb/Al2O3 interface before highly coherent Y films can be grown. Yttrium films grown on Nb buffers thinner than ∼500 [Formula: see text] show a similar two-peak line shape in [Formula: see text] scans through their specular Bragg peaks to that seen in the specular Nb Bragg peaks, with a resolution-limited feature on a broader diffuse peak. The resolution-limited feature depends on the thickness of the yttrium film, becoming weaker and having a stronger decay with increasing [Formula: see text] as the film thickness increases, while the width of the yttrium broad peak evolves as the square root of the width of the niobium Bragg peak. The data are discussed within the context of theories describing the scattering from films with misfit dislocations.

Generator voltage stabilisation for series-hybrid electric vehicles.

This paper presents a controller for use in speed control of an internal combustion engine for series-hybrid electric vehicle applications. Particular reference is made to the stability of the rectified DC link voltage under load disturbance. In the system under consideration, the primary power source is a four-cylinder normally aspirated gasoline internal combustion engine, which is mechanically coupled to a three-phase permanent magnet AC generator. The generated AC voltage is subsequently rectified to supply a lead-acid battery, and permanent magnet traction motors via three-phase full bridge power electronic inverters. Two complementary performance objectives exist. Firstly to maintain the internal combustion engine at its optimal operating point, and secondly to supply a stable 42 V supply to the traction drive inverters. Achievement of these goals minimises the transient energy storage requirements at the DC link, with a consequent reduction in both weight and cost. These objectives imply constant velocity operation of the internal combustion engine under external load disturbances and changes in both operating conditions and vehicle speed set-points. An electronically operated throttle allows closed loop engine velocity control. System time delays and nonlinearities render closed loop control design extremely problematic. A model-based controller is designed and shown to be effective in controlling the DC link voltage, resulting in the well-conditioned operation of the hybrid vehicle.

Stepping back to move forward: a current review of iPSCs in the fight against Alzheimer's disease.

The successful generation of the first iPSCs about ten years ago has provided deeper insight into previously unknown disease mechanisms and therapeutic opportunities for many diseases. In particular, iPSCs are becoming an important tool in advancing modeling and therapeutic intervention for Alzheimer's disease. In this manuscript, we assess the research climate surrounding the application of iPSCs to familial and sporadic Alzheimer's disease, including the generation and isolation of individualized neural stem cells, the introduction of neural stem cell transplants using iPSCs, and an estimation of the potential use of iPSCs as research models for Alzheimer's treatments and therapies. The clinical application of stem cells in the treatment of Alzheimer's disease appears promising, but much of the recent experimentation has been conducted using animal models or embryonic stem cells. As induced pluripotent stem cell research advances, iPSCs will likely provide investigators with a more applicable tool to progress advances in research and treatment for Alzheimer's and other neurodegenerative diseases.

Phase transition of chemically doped uniaxial relaxor ferroelectric.

We report a neutron scattering study of the ferroelectric phase transition in Sr0.585Ce0.025Ba0.39Nb2O6 (SBN-61:Ce). We find no evidence for a soft transverse optic phonon. We do, however, observe anisotropic diffuse scattering. This scattering has inelastic and elastic contributions. In the paraelectric phase the susceptibility associated with the elastic diffuse scattering from SBN-61:Ce increases on approaching the transition temperature. In the ferroelectric phase the lineshape of the elastic scattering is consistent with the form expected for the ferroelectric domain walls. In contrast to the macroscopic observations, the scattering properties of Ce-doped crystal do not exhibit important changes with respect to those of pure Sr0.61Ba0.39Nb2O6.

Overview: psychiatric sequelae to multiple trauma.

The authors discuss the setting, patients, and staff, and the role of psychiatric consultants in intensive care units and trauma centers. They point out the similarities and differences between patients with multiple trauma and those who have had open-heart surgery and head or spinal cord injuries. They also deal with the question of an element of self-destructive behavior in accidents and offer suggestions for the psychiatric management of severely traumatized patients. The authors conclude that the role and obligation of the psychiatrist of the the future will lie in crisis intervention within the medical-biological model.

The application of electron microscopy and cellular biochemistry to the autopsy. Observations on cellular changes in human shock.

A method based on the utilization of electron microscopy, morphometric analysis, tissue culture, and biochemical analysis in the study of human autopsies is described. In this method rapid sampling immediately following somatic death is conducted in order to make meaningful the application of such techniques. In addition to describing the procedure, we present some new findings relating to cellular changes associated with shock. As in cellular pathobiology, it is of utmost importance that ultrastructural changes be correlated with alterations in chemistry and function.

Rupture of thoracic aorta caused by blunt trauma. A fifteen-year experience.

During the 15 years from 1971 through 1985, 114 patients with rupture of the thoracic aorta caused by blunt trauma were admitted to the Shock Trauma Center of the Maryland Institute for Emergency Medical Services Systems. Mean age was 31.3 years (range, 15 to 80). Ninety were male and 24 were female, a 3.75:1 ratio. Of the 114, 89 (78.1%) survived initial resuscitation in the admitting area. Twenty five of the 89 initial survivors (28.1%) died during or after surgical repair. Paraplegia occurred in 11 of the 78 operating room survivors (14.1%). Further analysis was done of the 83 patients admitted in the 10-year period from 1976 through 1985. Mean Injury Severity Score, excluding aortic injury, was 18.2. Twenty-five of the 83 (30.1%) died during resuscitation in the admitting area or operating room. Seven others died during surgical repair and 12 died postoperatively, leaving 39 survivors (39/83 [47%] of total admissions and 39/58 [67.2%] of survivors of resuscitation). Paraplegia/paresis developed postoperatively in six of 34 (17.6%) cases involving shunt and four of 17 (23.5%) without shunt. Other major complications occurred in 21 of the operating room survivors. Statistically significant risk of death or major complication was associated with female sex, higher Injury Severity Score, lower admission blood pressure, larger hemothorax on admission, less qualified surgeon, major operation before aortic repair, use of shunt, and transfer directly from scene of injury. There was no advantage in this series to using or not using a shunt in preventing paraplegia. Mortality rates are realistic for a highly developed trauma system. Better techniques are needed to manage exsanguination and prevent paraplegia.

Traumatic rupture of the aorta. A five-year experience.

In the five-year period ending in October, 1975, 31 consecutive patients with traumatic rupture of the thoracic aorta underwent surgery at the University of Maryland Hospital or the Maryland Institute for Emergency Medicine. All cases were confirmed by preoperative aortogram. Rupture was confined to one or more sites in the descending thoracic aorta at or distal to the origin of the left subclavian artery. The age was a mean of 26 years. Operation was done within an average of 18 hours after injury. Significant nonthoracic injuries were present in every case. Six patients with positive findings on peritoneal lavage underwent exploratory laparotomy prior to thoracotomy because of shock. Surgical repair was done by use of left heart bypass in 2 cases (one death), a passive aorta-aorta shunt in 23 cases (5 deaths), and without shunt or bypass in 6 cases (no deaths). An end-to-end tubular Dacron graft was used to reconstruct the aorta in all but one patient. Over-all survival rate was 25 of 31 patients (81 per cent). Paraplegia developed in one patient and renal failure in 3 patients (2 deaths) in the aorta-aorta shunt group. Hypertension was present in 18 (72 per cent) of the survivors. Palsy of the left recurrent laryngeal nerve persisted in 8 (32 per cent) of the survivors. Two of the deaths were related to technical problems of the shunting procedure and 2 to intrapleural exsanguination before proximal aortic control could be achieved. Complications and blood loss were reduced in the group with no shunt. The series lends support to the rigorous aortographic search for ruptured thoracic aortas in trauma patients with widened mediastinum. Once experience has been gained with shunting techniques, tears of the descending thoracic aorta may be safely repaired without shunt if done expeditiously.

The use and application of autopsy in research.

The only limit to the use and application of the autopsy in research is the imagination of the investigator. As pathologists, it would appear that we have really neglected this powerful tool in recent decades and have undersold the potentiality of this method. As we hope to have made evident by the foregoing discussion, the field of research utilizing autopsy tissues is truly as broad as medicine itself, and if developed properly, becomes an indispensable part of the fabric of on-going research in areas of carcinogenesis, environmental disease, atherosclerosis, and aging.

Thyroid hormone responses in hemorrhagic shock: study in dogs and preliminary findings in humans.

One hour of hemorrhagic shock in the dog produces alterations in thyroid hormone metabolism far exceeding those seen after elective surgery or thermal injury. The changes in plasma thyroid hormone levels cannot be fully explained by carrier protein loss. Plasma concentrations of total thyroxine (T4) and triiodothyronine (T3) were significantly decreased after only 20 minutes of shock, continued to decrease throughout shock and resuscitation, and remained depressed for several days thereafter. Both hormones reached nadirs during volume replacement of 42% and 17% of baseline, respectively. The total T4 level normalized by the fifth postshock day, but the T3 concentration was still depressed on the ninth day. Plasma albumin, the principal canine thyroid hormone carrier, was significantly reduced 20 minutes after hemorrhage and remained low throughout convalescence. Concentrations of free T4 and T3 decreased during shock, but not as much as the total T4 and T3 concentrations. Reverse T3 levels, corrected for albumin loss, and T3 uptake values were increased during shock and resuscitation. Similar alterations in circulating thyroid hormone concentrations were seen in three patients with major traumatic injury and/or shock. The thyroid hormone changes in shock may represent another example of the "euthyroid sick syndrome."

Orogenital sex as a cause of nonfatal air embolism in pregnancy.

A case of nonfatal air embolism from orogenital sex in the 30th week of pregnancy is described. Because of a delay in the diagnosis, the patient did not receive hyperbaric oxygen therapy until 39 hours after the incident. Severe neurologic dysfunction persisted despite hyperbaric therapy. The world literature on orogenital sex in pregnancy with resultant air embolism is reviewed. The pathophysiology of air embolism and the rationale for hyperbaric oxygen treatment are presented. It is strongly recommended that survivors of this form of air embolism be transferred to hyperbaric facilities as soon as possible to reduce the long-term neurologic sequelae.

A national alcohol and trauma center survey. Missed opportunities, failures of responsibility.

The results of a national survey of trauma centers concerning their assessment and response to the problem of alcohol and trauma are reported. Surveys were returned from 154 trauma centers located in 43 states and the District of Columbia. The profile of the 125,000 patients treated at the centers is a 30-year-old man sustaining blunt trauma, usually in a vehicular crash. Two-thirds of centers estimated that the majority of their patients had abused alcohol. While acknowledging alcohol as a significant cause of trauma, only 55.2% of centers routinely obtain admitting blood alcohol levels. Less than a third of the centers employ alcoholism counselors. Most trauma centers are not providing services that allow them to fulfill their responsibility to detect and initiate treatment of alcohol abuse, a major cause of traumatic injury.

Marijuana and alcohol use among 1023 trauma patients. A prospective study.

Marijuana use prior to injury was determined prospectively in 1023 patients injured as the result of vehicular (67.6%) and nonvehicular (32.4%) trauma. Most were men (72.8%); most were 30 years of age or younger (58.4%). All were admitted directly from the scene of injury. Serum delta-9-tetrahydrocannabinol activity was ascertained using a radioimmunoassay. Activity of 2 ng/mL or more was detected in 34.7% of subjects. Blood alcohol determinations were made in 1006 patients; 33.5% were positive. Marijuana use among vehicular and nonvehicular trauma victims was not significantly different. Marijuana use was higher among those 30 years of age or younger and among men. Vehicular crash victims consumed alcohol more frequently. Use of marijuana and alcohol in combination (16.5%) was highly significant compared with marijuana alone (18.3%), alcohol alone (16.1%), or neither drug (49.1%).

Right ventricular outflow obstruction secondary to right-sided tamponade following myocardial trauma.

A case of isolated tamponade of the right side of the heart, seen as an abrupt change in the cardiac silhouette and as right ventricular outflow obstruction following myocardial trauma, is presented, along with a review of the English-language literature on delayed postoperative tamponade and loculated pericardial effusion. The importance of a low, fixed cardiac output and nonspecific physical findings in suggesting the clinical diagnosis is emphasized. The absence of many of the classic signs and symptoms of pericardial tamponade is noted, as is the possibility of unusual changes in the appearance or function of the heart in the presence of a loculated effusion. Finally, the differential diagnosis and the results of a variety of diagnostic techniques are discussed.

Lactosuria - a new metabolic feature of severe cerebrocranial trauma.

Under controlled dietary conditions the urinary excretion of lactose was studied in 15 healthy persons, 15 patients with cerebrocranial trauma and 15 patients with extracranial trauma. Urinary lactose levels were found to be markedly increased in patients with head injury and ranged from 10.3 to 147.7 mg/24 h with a mean 63.4 mg/24 h in contrast to patients with other injuries (3.1 to 17.0 mg/24 h, mean 9.4 mg/24 h; P less than 0.001), and healthy individuals (3.3 to 17.93 mg/24 h, mean 7.6 mg/24h; P less than 0.001). In the head injury group the lowest values were found in drowsy or disoriented patients with cerebral concussion and the highest in comatose subjects. The level of lactosuria decreases after approximately 12 to 16 days to normal levels even when the patient remains unconscious. An earlier return to normal excretion parallels or preceeds the reappearance of consciousness. Unlike alimentary lactosuria, caused by ingestion of milk or other dairy products in large quantities, the elevated lactose levels in head injury patients were not usually accompanied by a comparable rise in galactose excretion, mean 11.45 mg/24 h versus 9.17 mg/24 h in controls; P less than 0.2. The mechanism of enhanced lactose excretion in severe cerebrocranial trauma remains unknown. It is suggested that it may be associated with either an increased catabolism of brain gangliosides or a stimulated lactose synthesis in peripheral tissues probably due to the participation of the lactogenic hormone prolactin.

The effect of severe trauma on urinary cyclic AMP in children of different ages.

Under routine clinical conditions the urinary excretion of cyclic AMP was studied in 97 healthy children (3 months to 16 years old) and 65 child victims of various forms of trauma and proved to be age-dependent. The mean admission cAMP urinry levels for children of all ages were increased by 44.8% and were time dependent. In 26 injured children (3 months to 9.5 years old) the excretion increased to 12.10 +/-1.29 mumol cAMP/g creatinine as compared to 8.06 +/- 2.25 mumol cAMP/g crEAtinine (50.0%; P less than 0.01) and in 38 children (9.5-16 years) it rose to 6.43 +/- 4.12 from 4.72 mumol +/- 1.10 (36.2%; P less than 0.001). In 23 victims admitted within the first two hours after trauma the cAMP levels were elevated by 31.25% in contrast to 49.2% elevation in those admitted from 2 to 24 h after trauma. In a five-day follow-up of a group of 15 surviving patients the highest excretion of cAMP was found on the first day. It was followed by a steep decline until the values plateaued on the third day at values slightly elevated above control. Compared with the fifth day, the first day excretion expressed as mumol cAMP/24 h was enhanced by 92.3% (P less than 0.01) and as a ratio to creatinine (muol/g creatine) by 52.24% (P less than 0.05. In comparison with injured adults studied previously under analogical conditions, the cAMP excretory response to trauma in children differs in higher intensity (P less than 0.01) and in the nature of the daily pattern starting with the third day. It is pointed out that the intensity of the cAMP response to pathological stimuli may be age-dependent also in other clinical conditions.

Urinary cyclic AMP and post-traumatic acute renal failure.

Consecutive daily urinary excretion of cyclic AMP has been investigated in 16 patients with severe trauma or illness, five of whom developed acute renal failure (ARF). Fluctuations in the nucleotide excretion exceeded the range found in 20 healthy volunteers (1.26-14.74, mean 7.13+/-1.18 vs. 2.04-10.10, mean 5.07+/-2.21 micronmol/24 h). This resulted in a 41% increase of cAMP excretion in the group with normal renal function (P less than 0.003) with the highest individual increase of 87%. The excretion usually reached its peak by 24 h after trauma and its lowest value by the third day, (first day vs. third day; 7.82+/-4.23 vs. 3.96+/-2.58 micronmol/24 h, P less than 0.05 for a group of 11 patients), while creatinine clearance remained normal. In four patients with severe ARF, the mean urine volume was above control value but the cAMP excretion was reduced to 3.9 to 14.4% and in one patient with a mild ARF to 60.6%. Creatinine excretion of the group was less reduced than that of cAMP (41.2% vs. 19.6%, resp.). cAMP excretion declined proportionally with diminishing creatinine clearance. In the category of 33-65 ml/min it decreased by 33.4% to 3.39 micronmol+/-1.16 micronmol/24 h. cAMP/creatinine ratio proved to be a less sensitive indicator than cAMP/24 h. Daily output of cAMP and creatinine correlated highly with diuresis in ARF patients, controls (always P less than 0.001) and less in patients with normal renal function (P less than 0.02). Urinary cAMP appears to be a very sensitive and early indicator of the onset of ARF and subsequent recovery. This warrants its further study.

Superiority of the femoral artery of monitoring. A prospective study.

Continuous hemodynamic monitoring and ease of blood sampling are advantages of indwelling arterial catheters. The use and associated morbidity of arterial monitoring catheters were studied prospectively. Ninety-five percent of patients catheterized had multiple injuries, and almost 75 percent were 40 years of age or younger. Major and minor complication rates were similar with radial and femoral catheters, while the longevity of femoral catheters was almost twice that of radial catheters. Radial catheter-related sepsis did not occur when the duration of catheterization was less than 4 days. Tissue loss secondary to radical catheters can be minimized by immediate catheters can be minimized by immediate catheter removal upon appearance of ischemic changes. Our data support the preferential use of the femoral artery for long-term monitoring catheters in a younger patient population.