The effect of bioactive glass ceramics on the expression of bone-related genes and proteins in vitro

Using biodegradable bone substitutes in alveolar ridge augmentation avoids second-site surgery for autograft harvesting. Considerable efforts have been undertaken to develop rapidly resorbable bone substitute materials with a higher degree of biodegradability than tricalcium phosphate (TCP). This study examines the effect of novel biodegradable glass ceramics on the expression of bone-related genes and proteins by human bone-derived cells (HBDC) and compares this behavior with that of TCP. Test materials used were alpha-TCP, a surface-treated glass ceramic GB9N with crystalline phase Ca(2)KNa(PO(4))(2) and a small amount of amorphous silica phosphate; AP40 - a glass ceramic based on crystalline phases of apatite and wollastonite; and a glass ceramic Mg5 composed of 20.6% CaO, 58.5% P(2)O(5), 14.4% Na(2)O, 4.1% MgO and 2.4% CaF(2) (wt%). HBDC were grown on the substrata for 3, 5, 7, 14 and 21 days, counted and probed for various bone-related mRNAs and proteins (type I collagen (Col I), osteocalcin (OC), osteopontin (OP), osteonectin (ON), alkaline phosphatase (ALP) and bone sialoprotein (BSP)). The substrata supported continuous cellular growth for 21 days. By day 21, GB9N had the highest number of HBDC. GB9N induced significantly enhanced expression of Col I, ALP, OP, OC and ON mRNA at 3 days; of OP, OC and ON mRNA and protein at 7 and 14 days; and of ALP, OP and OC mRNA and Col I, ALP, BSP, ON and OP protein at 21 days. Since all novel glass ceramics supported cellular proliferation together with expression of bone-related genes and proteins at least as much as TCP, these ceramics can be regarded as potential bone substitutes. GB9N had the most effect on osteoblastic differentiation, thus suggesting that this material may possess a higher potency to enhance osteogenesis than TCP.     

Expert consensus and recommendations on safety criteria for active mobilization of mechanically ventilated critically ill adults

Introduction

The aim of this study was to develop consensus recommendations on safety parameters for mobilizing adult, mechanically ventilated, intensive care unit (ICU) patients.

Methods

A systematic literature review was followed by a meeting of 23 multidisciplinary ICU experts to seek consensus regarding the safe mobilization of mechanically ventilated patients.

Results

Safety considerations were summarized in four categories: respiratory, cardiovascular, neurological and other. Consensus was achieved on all criteria for safe mobilization, with the exception being levels of vasoactive agents. Intubation via an endotracheal tube was not a contraindication to early mobilization and a fraction of inspired oxygen less than 0.6 with a percutaneous oxygen saturation more than 90% and a respiratory rate less than 30 breaths/minute were considered safe criteria for in- and out-of-bed mobilization if there were no other contraindications. At an international meeting, 94 multidisciplinary ICU clinicians concurred with the proposed recommendations.

Conclusion

Consensus recommendations regarding safety criteria for mobilization of adult, mechanically ventilated patients in the ICU have the potential to guide ICU rehabilitation whilst minimizing the risk of adverse events.     

Isotopic evidence for omnivory among European cave bears: Late Pleistocene Ursus spelaeus from the Peştera cu Oase, Romania

Previous bone collagen carbon and nitrogen isotopic studies of Late Pleistocene European cave bears (Ursus spelaeus) have shown that these bears frequently had low nitrogen isotope values, similar to those of herbivores and indicating either unusual physiology related to hibernation or a herbivorous diet. Isotopic analysis of animal bone from the Peştera cu Oase (Cave with Bones), Romania, shows that most of its cave bears had higher nitrogen isotope values than the associated herbivores and were, therefore, omnivorous. The Oase bears are securely identified as cave bears by both their morphology and DNA sequences. Although many cave bear populations may have behaved like herbivores, the Oase isotopic data demonstrate that cave bears were capable of altering their diets to become omnivores or even carnivores. These data therefore broaden the dietary profile of U. spelaeus and raise questions about the nature of the carnivore guild in Pleistocene Europe.     

Correction of congenital heart defects in Jehovah's Witness children

Between August 1989 and July 2003 14 Jehovah's Witness children with congenital heart defects (CHD) aged under 14 years (median 2.9 years) and with a median weight of 14 kg underwent 16 operations with cardiopulmonary bypass (CPB). Five children had been operated on previously between one to three times. Preoperatively, 7 children were prepared with oral iron supplementation and 10 received erythropoietin. Mean hemoglobin (Hb) at admission was 14.4 g/dl (range 10.9 - 19.2). The cardiopulmonary bypass (CPB) circuit was modified to reduce total priming volume. High doses of aprotinin were administered. The modified ultrafiltration (MUF) circuit, used in 7 patients, was parallel to the ECC circuit with continuous circulation of the blood through a small shunt between the arterial and venous lines. Operations performed consisted of VSD closure (3 pts.), ASD closure (3 pts.), Fontan operation (2 pts.), and complete AV canal correction, aortic commissurotomy, Ross operation, Glenn shunt, cor triatriatum correction, MV reconstruction combined with left outflow tract stenosis resection, correction of absent pulmonary valve syndrome, and correction of tetralogy of Fallot in one patient each. There were no deaths. Mean duration of CPB was 192 min and mean aortic cross-clamp time 40 min. The Hb value at the end of the operation was 4.9 - 14.5 g/dl (mean 9.6) and at discharge it was 7.1 - 14.5 g/dl (mean 15.5). No blood or blood products were used in any patient. CONCLUSION: Bloodless cardiac surgery with and without CPB can be safely performed in Jehovah's Witness infants and children.     

The sensitivity of three commonly used outcome measures to detect change amongst patients receiving inpatient rehabilitation following stroke

OBJECTIVE: To investigate the sensitivity of three commonly used functional outcome measures to detect change over time in subjects receiving inpatient rehabilitation post stroke. DESIGN: Subjects were assessed within one week of admission and one week of discharge from an inpatient rehabilitation facility. Several parameters of sensitivity were calculated, including floor and ceiling effects, the percentage of subjects showing no change and the effect size of the change between admission and discharge. SETTING: The medical rehabilitation ward of an inpatient rehabilitation facility. SUBJECTS: Seventy-eight subjects receiving inpatient rehabilitation following a first or recurrent stroke. MEASURES: Five-metre walk, comfortable pace (gait speed), the Berg Balance Scale and the Motor Assessment Scale. RESULTS: Sixty-one subjects had complete admission and discharge data. Gait speed and the Berg Balance Scale were both sensitive to change and demonstrated large effect sizes. The Motor Assessment Scale item five also showed a large effect size and was able to detect change amongst lower functioning subjects. The other items of the Motor Assessment Scale were less useful, in particular, the effect sizes for upper extremity change scores were small (d=0.36-0.5) and the majority of subjects (44.3-63.9%) showed no change over time on these measures. CONCLUSION: Gait speed, the Berg Balance Scale and the Motor Assessment Scale item five were sensitive to change over time in this sample.     

123I-antileukoproteinase scintigraphy reveals microscopic cartilage alterations in the contralateral knee joint of rats with "monarticular" antigen-induced arthritis

OBJECTIVE: To assess the involvement of the contralateral knee joint in monarticular antigen-induced arthritis (AIA) by scintigraphy with the cationic (pI >10), 123I-labeled, serine proteinase inhibitor antileukoproteinase (123I-ALP) and to compare the scintigraphic findings with those of radiography and high-resolution ex vivo magnetic resonance imaging (MRI). METHODS: Lewis rats with chronic AIA were examined 2.5 months following arthritis induction (injection of 500 microg of methylated bovine serum albumin/saline into the ipsilateral [arthritic] knee joint and injection of phosphate buffered saline into the contralateral knee joint following systemic immunization). 123I-ALP was injected intravenously into normal rats (n = 4) or rats with AIA (n = 6). The ipsilateral and contralateral knee joints and both ankles were examined by scintigraphy and radiography. Joint cartilage was examined by high-resolution ex vivo MRI, histopathology, and measurement of tissue radioactivity. RESULTS: ALP accumulation (typically observed in normal articular cartilage) was lost in both the ipsilateral and the contralateral knee joints, but not in the clinically unaffected ankles of rats with AIA. In both knee joints, 123I-ALP target:background ratios and cartilage radioactivity correlated negatively with the loss of toluidine blue staining in cartilage, which documents the depletion of charged matrix molecules. Findings of histopathology confirmed mild alterations in the ipsilateral knee joint and even milder alterations in the contralateral knee joint, while the ankles were normal. Radiography and high-resolution ex vivo MRI failed to detect abnormalities in the contralateral knee joint. CONCLUSION: Loss of ALP accumulation appears to document proteoglycan depletion, even in the microscopically altered cartilage of the contralateral knee joint in AIA. These findings underscore the high sensitivity of 123I-ALP for in vivo detection of biochemical cartilage alterations in arthritis, and furthermore, question the use of the contralateral knee joint as a normal control in AIA.     

Circuit class therapy versus individual physiotherapy sessions during inpatient stroke rehabilitation: a controlled trial

OBJECTIVE: To compare the effectiveness of circuit class therapy and individual physiotherapy (PT) sessions in improving walking ability and functional balance for people recovering from stroke. DESIGN: Nonrandomized, single-blind controlled trial. SETTING: Medical rehabilitation ward of a rehabilitation hospital. PARTICIPANTS: Sixty-eight persons receiving inpatient rehabilitation after a stroke. INTERVENTIONS: Subjects received group circuit class therapy or individual treatment sessions as the sole method of PT service delivery for the duration of their inpatient stay. MAIN OUTCOME MEASURES: Five-meter walk test (5MWT), two-minute walk test (2MWT), and the Berg Balance Scale (BBS) measured 4 weeks after admission. Secondary outcome measures included the Iowa Level of Assistance Scale, Motor Assessment Scale upper-limb items, and patient satisfaction. Measures were taken on admission and 4 weeks later. RESULTS: Subjects in both groups showed significant improvements between admission and week 4 in all primary outcome measures. There were no significant between group differences in the primary outcome measures at week 4 (5MWT mean difference, .07m/s; 2MWT mean difference, 1.8m; BBS mean difference, 3.9 points). A significantly higher proportion of subjects in the circuit class therapy group were able to walk independently at discharge (P=.01) and were satisfied with the amount of therapy received (P=.007). CONCLUSIONS: Circuit class therapy appeared as effective as individual PT sessions for this sample of subjects receiving inpatient rehabilitation poststroke. Favorable results for circuit classes in terms of increased walking independence and patient satisfaction suggest this model of service delivery warrants further investigation.