Therapeutic effect of posture in sleep apnea

Four patients with mild to moderate obstructive sleep apnea were monitored first in the supine posture to establish a diagnosis of obstructive sleep apnea (apnea indices 33, 12, 22, 36). A second polysomnogram, obtained while the patients slept in the lateral posture, showed a dramatic decrease in apnea (apnea indices 5, 0, 0.2, and 0) and snoring. Each patient had an enlarged uvula, which moved to the side in the lateral posture. We conclude that sleeping in the lateral posture may be therapeutic in some patients with obstructive sleep apneas.     

Renal disease in type I glycogen storage disease

Although kidney enlargement occurs in Type I glycogen storage disease, renal disease has not been considered a major problem. Death from renal failure in three patients known to us prompted a study of renal function in this disorder. Of the 38 patients with Type I glycogen storage disease under our care, the 18 children under 10 years old had normal renal function. Fourteen of the 20 older patients (13 to 47 years) had disturbed renal function, manifested by persistent proteinuria; many also had hypertension, hematuria, or altered creatinine clearance. Progressive renal insufficiency developed in 6 of these 14 patients, leading to three deaths from renal failure. At the onset of proteinuria, creatinine clearance was increased in seven patients (3.05 +/- 0.68 ml per second per 1.73 m2 of body-surface area; range, 2.47 to 4.13 [normal range, 1.33 to 2.33 ml per second per 1.73 m2]). Renal biopsies were performed in three patients after an average of 10 years of proteinuria. All three biopsies demonstrated focal segmental glomerulosclerosis in various stages of progression. Our data suggest that chronic renal disease is a frequent and potentially serious complication of Type I glycogen storage disease. In addition to treating hypoglycemia vigorously, physicians should monitor renal function carefully in patients with this disorder.     

Opposing roles of membrane and soluble forms of the receptor for advanced glycation end products in primary respiratory syncytial virus infection

Respiratory syncytial virus (RSV), a common respiratory pathogen in infants and the older population, causes pulmonary inflammation and airway occlusion that leads to impairment of lung function. Here, we have established a role for receptor for advanced glycation end products (RAGE) in RSV infection. RAGE-deficient (ager(-/-)) mice were protected from RSV-induced weight loss and inflammation. This protection correlated with an early increase in type I interferons, later decreases in proinflammatory cytokines, and a reduction in viral load. To assess the contribution of soluble RAGE (sRAGE) to RSV-induced disease, wild-type and ager(-/-) mice were given doses of sRAGE following RSV infection. Of interest, sRAGE treatment prevented RSV-induced weight loss and neutrophilic inflammation to a degree similar to that observed in ager(-/-) mice. Our work further elucidates the roles of RAGE in the pathogenesis of respiratory infections and highlights the opposing roles of membrane and sRAGE in modulating the host response to RSV infection.     

Bond of acrylic teeth to different denture base resins after various surface-conditioning methods

The study examined the bond between different denture base resins and highly cross-linked acrylic denture teeth with different base surface-conditioning methods. One hundred fifty highly cross-linked resin denture teeth (SR-Antaris, No. 11, Ivoclar-Vivadent, FL) were divided into five groups with different surface-conditioning methods of the base surfaces of the teeth (C = control, no surface conditioning, MM = application of methyl methacrylate monomer, SB = sand blasting, SBB = sand blasting + bonding agent, TSS = tribochemical silica coating + silanization). Teeth were bonded to either a cold-cured denture base resin (ProBase Cold, Ivoclar-Vivadent, FL) or heat-cured denture base resins (SR Ivocap Plus, Ivoclar-Vivadent, FL and Lucitone 199, Dentsply, USA). After 24 h of storage in distilled water, compressive load was applied at 90° on the palatal surface of each tooth until fracture. Median failure load ranged between 103 and 257 N for Probase Cold groups, 91 to 261 N for Lucitone 199, and 149 to 320 N for SR Ivocap Plus. For Probase Cold, significant highest failure loads resulted when teeth were treated with SB, SBB, or TSS. For Lucitone 199, significant highest failure loads has been found with MM and TSS treatment. For SR Ivocap Plus, highest failure loads resulted using SBB and TSS. Conditioning of the base surfaces of the teeth prior to denture base processing is highly recommended. Tooth bond is significantly affected by the surface-conditioning method and applied denture base resin. Tribochemical silica coating + silanization method can be recommended for pre-treatment of teeth applying either heat-cured or cold-cured denture base resin.     

Toward acellular xenogeneic heart valve prostheses: Histological and biomechanical characterization of decellularized and enzymatically deglycosylated porcine pulmonary heart valve matrices

The use of decellularized xenogeneic heart valves might offer a solution to overcome the issue of human valve shortage. The aim of this study was to revise decellularization protocols in combination with enzymatic deglycosylation, in order to reduce the immunogenicity of porcine pulmonary heart valves, in means of cells, carbohydrates, and, primarily, Galα1-3Gal (α-Gal) epitope removal. In particular, the valves were decellularized with sodium dodecylsulfate/sodium deoxycholate (SDS/SD), Triton X-100 + SDS (Tx + SDS), or Trypsin + Triton X-100 (Tryp + Tx) followed by enzymatic digestion with PNGaseF, Endoglycosidase H, or O-glycosidase combined with Neuraminidase. Results showed that decellularization alone reduced carbohydrate structures only to a limited extent, and it did not result in an α-Gal free scaffold. Nevertheless, decellularization with Tryp + Tx represented the most effective decellularization protocol in means of carbohydrates reduction. Overall, carbohydrates and α-Gal removal could strongly be improved by applying PNGaseF, in particular in combination with Tryp + Tx treatment, contrary to Endoglycosidase H and O-glycosidase treatments. Furthermore, decellularization with PNGaseF did not affect biomechanical stability, in comparison with decellularization alone, as shown by burst pressure and uniaxial tensile tests. In conclusion, valves decellularized with Tryp + Tx and PNGaseF resulted in prostheses with potentially reduced immunogenicity and maintained mechanical stability.     

Delivering the diagnosis of MS--results of a survey among patients and neurologists

OBJECTIVES: The need for an early disclosure of the diagnosis of multiple sclerosis (MS) has become more pressing with the publication of two recent randomized trials which have indicated that very early treatment may favourably alter the disease course. We assessed the current status of diagnostic and therapeutic information on MS from the point of view of patients and neurologists. METHODS: A standardized questionnaire was sent out through the patients' self-help organization in Hamburg, Germany and to all neurologists. RESULTS: A total of 434 of 1300 patients and 80 of 250 neurologists replied. Neurologists gave 90% of the diagnoses but only 50% of patients reported them as the major aid helping to understand the disease. Fifty per cent of patients were not informed about any form of therapy at the time of diagnosis regardless of whether their MS diagnosis was disclosed within the last 5 years or earlier. In contrast to physicians, patients voted for information about a possible MS even if the diagnosis may not yet be clear. CONCLUSION: From the patients' perspective, information about the diagnosis of MS should be more straightforward, and more information about therapies should be provided.     

Ultrasound can predict regenerate stiffness in distraction osteogenesis

Assessing the regenerate strength in distraction osteogenesis is crucial for clinical treatment. Several methods have been used to achieve this, including plain radiography, digital radiography, quantitative computed tomography, dual energy xray absorptiometry, and ultrasound. The aim of the current study was to investigate the use of ultrasound in monitoring regenerate formation and to correlate this to biomechanical testing results. An osteotomy was done on the tibia of 30 Yucatan micropigs and an Ilizarov-type half-ring external fixator was mounted. After a 5-day latency period, the tibias were distracted for 10 days and then left to consolidate for 10 days. Seven ultrasound examinations were done during Day 15 through Day 25. After sacrifice, the bone mineral density was measured using quantitative computed tomography. Maximum load and torsional stiffness were measured and correlated with ultrasound measurements and bone mineral density. The ultrasound penetration depth and the bone mineral density correlated closely with torsional stiffness. Ultrasound can be a noninvasive predictor of bone regenerate strength in the early phase of distraction osteogenesis, which may reduce the need for radiographs.     

Sonochemically produced fluorocarbon microspheres: A new class of magnetic resonance imaging agent

With the intent of increasing the signal-to-noise ratio (SNR) of fluorine magnetic resonance imaging and enabling new applications, we have developed a novel class of agents based on protein encapsulation of fluorocarbons. Microspheres formed by high-intensity ultrasound have a gaussian size distribution with an average diameter of 2.5 μm. As with conventional emulsions, these microspheres target the reticuloendothelial system. However, our sonochemically produced microspheres, because of a high encapsulation efficiency, show increases in the SNR of up to 300% compared to commercially available emulsions. We also demonstrate an increase in the circulation life-time of the microspheres within the bloodstream by more than 30-fold with a chemical modification of the outer surface of the microsphere. Finally, by encapsulating mixtures of fluorocarbons that undergo solid/liquid phase transitions, we can map temperature in the reticuloendothelial system, with signal changes of approximately 20-fold over a 5°C range.     

Homologous growth hormone accelerates healing of segmental bone defects

The effect of homologous recombinant porcine growth hormone (r-pGH) on secondary fracture healing was investigated in a diaphyseal defect of the tibia in Yucatan micropigs. A 1 cm defect of the tibia was created surgically and stabilized with an AO 3.5 mm DCP plate. The treatment group (12 animals) received 100 microg of r-pGH per kilogram of body weight subcutaneously once per day, whereas the control pigs (12 animals) received 1 mL of sodium chloride as placebo. For evaluation of the GH-axis, serum levels of insulin-like growth factor-I (IGF-I) were sampled every fourth day. The animals were killed 6 weeks after surgery. Quantitative computed tomography (qCT) was performed to determine bone mineral density (BMD) and bone mineral content (BMC) of the defect zone. The torsional stiffness and the torsional failure load were measured by destructive torsional testing of the defect and contralateral tibiae. qCT measurements revealed a significant increase in the BMC of the defect zone in the treatment group compared with controls (GH BMC = 2833 +/- 679 mg, placebo BMC = 2215 +/- 636 mg; p < 0.05), whereas the BMD values were similar in both groups (GH BMD = 668 +/- 60 mg/mm(2), placebo BMD = 629 +/- 52 mg/mm(2), p = 0.12). Torsional failure load was 70% higher and torsional stiffness 83% higher in the treatment group than in the control group (p < 0.05). The mean serum level of IGF-I in the treatment group increased to 382% of the preoperative basal level and decreased to 69% in the control group, and this difference was highly significant (p < 0.001). Our data indicate that daily administration of recombinant GH leads to an increase of serum IGF-I levels and stimulates secondary fracture healing, resulting in increased mechanical strength and stiffness of the callus.