Contribution of peripheral N-methyl-D-aspartate receptors to c-fos expression in the trigeminal spinal nucleus following acute masseteric inflammation

In this study, we examined the contribution of N-methyl-D-aspartate (NMDA) receptors on c-fos expression in the trigeminal brainstem nuclei following acute muscle inflammation. Mustard oil (MO; 20%, 30 microL) injected into the masseter muscle induced extensive peripheral edema and Fos-like immunoreactivity (Fos-LI) in several trigeminal brainstem areas including the subnucleus caudalis of the trigeminal spinal nucleus (Vc), the ventral and dorsal regions of the Vc/subnucleus interpolaris transition zone, and the paratrigeminal nucleus. In order to assess the effect of antagonizing NMDA receptors on MO-induced Fos-LI, rats were pre-treated with two different doses of i.v. MK-801 (0.3 mg/kg, 3 mg/kg), a non-competitive NMDA receptor antagonist, 30 min prior to MO injection. Additional groups of rats received MK-801 (0.3 mg/kg) directly in the masseter muscle or in the biceps muscle 5 min prior to MO injection. A higher dose of i.v. MK-801 (3 mg/kg) and MK-801 given locally into the masseter muscle (0.3 mg/kg) produced a significant reduction in total number of MO-induced Fos-LI. Further analyses revealed that pre-treatment with MK-801 (3 mg/kg i.v.) significantly reduced the Fos-LI all throughout the Vc. Only at the caudal Vc, there was a dose-dependent reduction of MO induced Fos-LI. Pre-treatment with masseteric MK-801 also significantly reduced the Fos-LI in the caudal Vc, with the effect greater than that produced by the same dose of MK-801 given intravenously. These results suggest that peripheral NMDA receptors contribute to nociceptive processing from craniofacial muscles.     

Consanguinity-associated kidney diseases in Lebanon: an epidemiological study

Consanguineous marriages are common in many countries of the Middle East including Lebanon. Their impact on the repartition of kidney diseases and on the risk for familial nephritis is not known. We surveyed all of the dialysis centers in Lebanon. Nine hundred and twenty-five (925) patients and their private physicians were asked to answer a questionnaire. More than half of the hemodialysis (HD) patients had an unknown etiology of their kidney disease. Diabetes, polycystic kidney disease (PKD), chronic pyelonephritis and nephrosclerosis (NS) were the most commonly documented diagnoses. Consanguinity was present in 26% of the total HD population. More consanguineous patients with unknown renal etiology were diagnosed with their kidney diseases and initiated on dialysis before the age of 30 when compared with their non-consanguineous counter-parts (45% versus 33%, P<0.02 and 42% versus 27%, P<0.01), respectively. Similarly, consanguineous polycystic patients were diagnosed and started earlier on dialysis when compared with the non-consanguineous population (34% versus 12%, P<0.05 and 28% versus 8%, P<0.05), respectively suggesting a different disease pattern. Furthermore, the risk for family history of kidney disease was noticeable in the non-consanguineous population and significantly higher among the consanguineous patients (12% versus 18%, P<0.04). Consanguinity-associated kidney diseases affected all religious communities, in particular the Muslim and the Druze (36 and 39%), respectively versus 17% of the Christian community. Certain geographical areas were more involved than others such as the North, South and the Bekaa with the highest percentage (40%) in the latter. Socio-economical level was not a contributing factor. We conclude that the documentation of the underlying etiology in end-stage renal diseases (ESRD) seems to be deficient. Furthermore, consanguinity is prevalent in the Lebanese dialysis patients population, in particular the Muslim and the Druze communities. Consanguinity-associated kidney diseases pattern seems to differ from that of the general HD population by disease diagnosis and initiation at a younger age and a significantly higher risk for familial renal disease. It is a cultural phenomenon prevalent predominantly in the rural areas. We recommend a multi-approach including educational, informative and probably legislative strategy in order to limit and hopefully discourage consanguineous marriages.     

Malignant clinical behavior of cardiac myxomas and "myxoid imitators"

The clinical experience with cardiac myxomas and "myxoid imitators" at the Humana Heart Institute International is reviewed and contrasted with a comprehensive review of the world literature. Twenty-two patients with primary cardiac tumors have been treated at our institution. Three (13.6%) of them had myxoid imitators, and 19 had classic myxomas. One of the 19 patients with a classic myxoma had recurrence on two occasions (recurrence rate, 5.3%). The cases of 57 patients from the world literature are reviewed. Recurrence and/or metastases (including formation of mycotic aneurysm) occurred in approximately 50% of these patients. The overall mortality in these patients was 47%. This review provides documentation of the malignant clinical behavior of cardiac myxomas and myxoid imitators. Neither local recurrence nor regrowth of the tumor in a new location, whether intracardiac or extracardiac, can be predicted from the microscopic appearance of the primary tumor. Resection of the myxoma with a wide margin is the recommended surgical procedure but does not ensure a cure. Therefore, long-term follow-up is mandatory.     

Temporary antibiotic loaded acrylic hip replacement: a novel method for management of the infected THA

Postoperative infection after hip joint replacement is an uncommon but potentially devastating complication in contemporary orthopaedics. Management in two stages is the more favored approach in North America. This introduces difficulty with patient management in the interval between stages, delays rehabilitation, and introduces technical difficulty during the second stage. A method has been developed whereby a temporary antibiotic-loaded facsimile of the hip is introduced at the first stage, designed to maintain stability of the joint, length of the limb, and mobility of the patient. It has been used in a total of 86 cases to date. The results in 46 cases with a minimum follow-up of 2 years are reviewed in this article. The infection was controlled in 93.5% of cases.     

The treatment of periprosthetic fractures of the femur using cortical onlay allograft struts

Periprosthetic fractures of the femur are a complex problem to treat. Careful planning is essential before embarking on such a technically demanding procedure. There are many factors to be considered, including the premorbid condition of the patient and previous experience and training of the surgeon. Important factors relating directly to the fracture include the site, stability of the implant, and the state of the surrounding bone stock.     

The prevention of periprosthetic fractures in total hip and knee arthroplasty

Periprosthetic fractures in total hip and total knee arthroplasty lead to considerable morbidity in terms of component fixation, bone loss, and subsequent function. The management of these fractures is technically demanding and may result in suboptimal fixation owing to poor bone stock. The prevention, early recognition, and appropriate management of such fractures are therefore critical. The pathogenesis of periprosthetic factors is multifactorial. There are a number of intrinsic patient influences such as bone stock, biomechanics, and compliance. There are also a host of extrinsic factors over which the surgeon has more control. The prevention of periprosthetic fractures requires careful preoperative planning and templating, the availability of the necessary expertise and equipment, and knowledge of the potential pitfalls so that these can be avoided both intraoperatively and in follow-up.     

The reliability and validity of the Vancouver classification of femoral fractures after hip replacement

This study assessed the reliability and validity of a new classification system for fractures of the femur after hip arthroplasty. Forty radiographs were evaluated by 6 observers, 3 experts and 3 nonexperts. Each observer read the radiographs on 2 separate occasions and classified each case as to its type (A, B, C) and subtype (B1, B2, B3). Reliability was assessed by looking at the intraobserver and interobserver agreement using the kappa statistic. Validity was assessed within the B group by looking at the agreement between the radiographic classification and the intraoperative findings. Our findings suggest that this classification system is reliable and valid. Intraobserver agreement was consistent across observers, ranging from 0.73 to 0.83. There was a negligible difference between experts and nonexperts. Interobserver agreement was 0.61 for the first reading and 0.64 for the second reading by kappa analysis, indicating substantial agreement between observers. Validity analysis revealed an observed agreement kappa value of 0.78, indicating substantial agreement. This study has shown that this classification is reliable and valid.