Hypothermic circulatory arrest does not increase the risk of ascending thoracic aortic aneurysm resection

OBJECTIVE: The purpose of this study was to investigate the safety and efficacy of a period of deep hypothermic circulatory arrest (DHCA) during elective replacement of the ascending thoracic aorta. SUMMARY BACKGROUND DATA: DHCA has been implemented in ascending thoracic aortic aneurysm resection whenever the anatomy or pathology of the aorta or arch vessels prevents safe or adequate cross-clamping. Profound hypothermia and retrograde cerebral perfusion have been shown to be neurologically protective during ascending aortic replacement under circulatory arrest. METHODS: The authors conducted a retrospective analysis of 91 consecutive patients who underwent repair of chronic ascending thoracic aortic aneurysms from 1986 to present. The authors hypothesized that patients undergoing DHCA with or without retrograde cerebral perfusion during aneurysm repair were at no greater operative risk than patients who received aneurysm resection while on standard cardiopulmonary bypass. RESULTS: There were no significant differences in hospital mortality, stroke rate, or operative morbidity between patients repaired on DHCA when compared to those repaired on cardiopulmonary bypass. CONCLUSIONS: DHCA with or without retrograde cerebral perfusion does not result in increased morbidity or mortality during the resection of ascending thoracic aortic aneurysms. In fact, this technique may prevent damage to the arch vessels in select cases and avoid the possible complications associated with cross-clamping a friable or atherosclerotic aorta.     

Sonographic borderlands in the fetal abdomen

Ultrasonographic examination of the fetal abdomen is an integral part in all routine fetal sonograms and can provide significant information about the status and prognosis of the fetus. Although many types of fetal anomalies can be identified (i.e., gastroschisis, omphalocele, or congenital diaphragmatic hernia), there are several sonographic findings that are not clearly anomalous, but may be associated with poor fetal outcome. Echogenic fetal bowel, small or absent fetal stomach and fetal intra-abdominal calcifications all fall into this category. This article reviews the recent literature as it relates to these topics, including suggestions regarding the need for further action, and the types of further actions that are available to help identify abnormal fetuses and prevent unnecessary and/or invasive testing of normal ones.     

The G3 domain of versican inhibits mesenchymal chondrogenesis via the epidermal growth factor-like motifs

Versican is a highly expressed proteoglycan in zones of developing tissues. To investigate whether versican plays a role in cell differentiation, we studied its role in mesenchymal condensation and chondrogenesis. Here we report that a mini-versican gene product inhibits mesenchymal chondrogenesis but not condensation. The mini-versican-treated mesenchymal cultures form fewer, smaller cartilaginous nodules and produced lower levels of link protein and type II collagen. The versican G3 domain alone, but not G1, was sufficient to inhibit mesenchymal chondrogenesis. Deletion of two epidermal growth factor (EGF)-like motifs in the G3 domain abolished the effect of versican. The G3 domain of aggrecan, which does not contain an EGF-like motif, did not inhibit mesenchymal chondrogenesis. We also generated a chimera construct containing the two EGF-like motifs of versican and the G3 domain of aggrecan, and we observed that this chimera construct inhibited chondrogenesis to a lesser extent than did the full-length versican G3 construct. Direct transfection of mesenchymal cells with different constructs produced similar results. Furthermore, treatment with versican antisense oligonucleotides and transfection with a versican antisense construct promoted chondrogenesis. Taken together, our results strongly suggest that versican inhibits mesenchymal chondrogenesis via its EGF-like motifs.     

Estimates of the prevalence of arthritis and selected musculoskeletal disorders in the United States

OBJECTIVE: To provide a single source for the best available estimates of the national prevalence of arthritis in general and of selected musculoskeletal disorders (osteoarthritis, rheumatoid arthritis, juvenile rheumatoid arthritis, the spondylarthropathies, systemic lupus erythematosus, scleroderma, polymyalgia rheumatica/giant cell arteritis, gout, fibromyalgia, and low back pain). METHODS: The National Arthritis Data Workgroup reviewed data from available surveys, such as the National Health and Nutrition Examination Survey series. For overall national estimates, we used surveys based on representative samples. Because data based on national population samples are unavailable for most specific musculoskeletal conditions, we derived data from various smaller survey samples from defined populations. Prevalence estimates from these surveys were linked to 1990 US Bureau of the Census population data to calculate national estimates. We also estimated the expected frequency of arthritis in the year 2020. RESULTS: Current national estimates are provided, with important caveats regarding their interpretation, for self-reported arthritis and selected conditions. An estimated 15% (40 million) of Americans had some form of arthritis in 1995. By the year 2020, an estimated 18.2% (59.4 million) will be affected. CONCLUSION: Given the limitations of the data on which they are based, this report provides the best available prevalence estimates for arthritis and other rheumatic conditions overall, and for selected musculoskeletal disorders, in the US population.     

Failure prediction of composite T-beams subjected to lateral load on the web

A study of the design and mechanical behaviour of co-cured T-beams subjected to lateral loading on the web is presented. The T-beams were manufactured by press moulding from pre-pregs of uni-directional and fabric glass reinforced high performance epoxy matrix. A special fixture was designed in order to carry out tests where the T-beams were laterally loaded on the web and clamped on the flange. Analytical and numerical studies were performed to predict the failure load to compare with the experimental results. The multilayer anisotropic continuum theory for delamination analysis of curved beams subjected to end moments and forces was used to compute the delamination stresses in the quarter cylindrical beam of the junction between the flange and the web. Finite element analyses of the T-beams were performed using plate/shell elements and two models were used for the joining between web and flange, to compute the planar stresses in the beam. The scatter obtained in the experimental results can be explained by the presence of two failure modes: one due to delamination associated with the through the thickness stresses developed in the curved part of the beam, the other related with failure occurring due to tangential stresses in the most highly stressed plies.     

In vitro amphotericin B effects on growth, viability and dimorphism of Paracoccidioides brasiliensis: reversal of the treatment

The reversed dermal graft has been employed in reconstructive plastic surgery for almost 80 years. It is recommended that the dermatologic surgeon use this graft technique whenever a case calls for the combined advantages of the split-thickness skin graft for poorly vascularized areas and the axial pedicle flap appropriate to areas subject to marked mechanical strain. We present cases in which defects on the scalp, sole, palm, and great toe have been covered by reversed dermal graft and split-thickness skin graft in a single operation with excellent results. Our modification of the technique has proved that simultaneous grafting with reversed dermis and split-thickness skin graft produces satisfactory results, reduces postoperative care by 2 weeks, and obviates repeated anesthesia.     

Pregnancy outcomes following false-positive multiple marker screening tests

Pregnancy outcomes in women with a false-positive midtrimester multiple marker screening test (MMST) were reviewed. A genetic database was used to identify all women > or = age 30 who had a MMST at 15-20 weeks of gestation, a targeted ultrasound, and amniocentesis, and complete pregnancy outcome data. All patients with an abnormal fetal ultrasound (US) or karyotype were excluded. The incidence of adverse outcomes (defined as fetal death, preterm delivery, or a birth weight less than the 10th percentile for gestational age), in those women with a positive MMST (risk of Down's syndrome > or = 1:190) was compared to the incidence of adverse outcomes in control women with negative MMST. Chi-square analysis and Fisher's exact tests were used for comparisons as appropriate. Complete data was available from 1135 women. Seventy-seven percent were over age 35. Two hundred and forty-six women (22%) had a positive multiple marker test. No significant differences in outcomes were discovered after comparisons to controls: fetal death 1 of 246 (0.4%) versus 12 of 889 (1.3%), p = 0.32; preterm delivery 32 of 246 (13.0%) versus 147 of 889 (16.5%), p = 0.17; birth weight less than the 10th percentile, 9 of 246 (3.7%) versus 30 of 889 (3.4%), p = 0.83. Our data suggest that women > or = age 30 with a false-positive MMST and a normal midtrimester obstetrical sonogram are not at an increased risk for adverse pregnancy outcomes in later gestation.     

Anxiolytic activity of glycine-B antagonists and partial agonists--no relation to intrinsic activity in the patch clamp

On the basis of animal models, anxiety was one of the first suggested clinical applications of partial agonists of the glycineB site coupled to the NMDA receptor. It is not certain, however, whether these findings can be extended to full glycineB antagonists and what is the relation between intrinsic activity (degree of NMDA receptor antagonism) and anxiolytic effect. In the present study several NMDA receptor antagonists, including several glycineB antagonists/partial agonists, were tested for anxiolytic activity in the Vogel conflict test and the elevated plus-maze. Additionally, the intrinsic activities of the glycineB partial agonists used [ACPC, (R,+)-HA-966 and D-cycloserine] were compared in patch-clamp experiments in cultured neurones. In the plus-maze the most striking increase in the time spent in open arms (index of anxiolytic effect) was seen after diazepam and D-cycloserine (at doses that did not change locomotion). Also reliable (dose-dependent), although weaker, anxiolytic activity was produced by the uncompetitive NMDA receptor antagonist (+)MK-801 and the competitive antagonist CGP 39551. Modest anxiolytic-like effect in the plus-maze was also observed after the glycineB antagonist L-701,324 and the partial agonist (+,R)-HA-966. Uncompetitive antagonists memantine and amantadine, the glycineB partial agonist ACPC (up to 600 mg/kg) or the full antagonists MRZ 2/570, MRZ 2/571 and MRZ 2/576 had no effect. In the Vogel conflict test neither memantine, nor any of the full glycineB antagonists tested (L-701,324 and MRZ 2/576), showed anxiolytic activity. Patch-clamp studies revealed that the intrinsic activity of (+,R)-HA-966, D-cycloserine and ACPC was 13, 57 and 92%, respectively, as compared to that of glycine itself (100%). In conclusion, for the agents tested there is no clear relation between the levels of intrinsic activity, i.e. degree of NMDA receptor inhibition, and anxiolytic activity. Moreover, L-701,324 and MRZ-type glycineB full antagonists do not exchibit anxiolytic activity in the elevated plus-maze and Vogel conflict test.