The amputee mobility predictor: an instrument to assess determinants of the lower-limb amputee's ability to ambulate

OBJECTIVES: To describe the development of the Amputee Mobility Predictor (AMP) instrument designed to measure ambulatory potential of lower-limb amputees with (AMPPRO) and without (AMPnoPRO) the use of a prosthesis, and to test its reliability and validity. DESIGN: Measurement study using known groups method and concurrence with existing measures. SETTING: Academic medical center. PARTICIPANTS: A convenience sample of 191 lower-limb amputee subjects who had completed prosthetic training, 24 in the reliability study (mean age +/- standard deviation, 68.3+/-17.9y, range, 28-99y) and 167 in the validity study (mean age, 54.8+/-18.6y; range, 18-100y). INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Intra- and interrater reliability; construct validity by known groups method; concurrent validity by comparisons with 6-minute walk test, Comorbidity Index, age, and time since amputation; predictive validity by comparison with 6-minute walk test after controlling for other factors. RESULTS: Interrater reliability was.99 for subjects tested with and without their prosthesis; intrarater reliability was.96 and.97. Both the AMPnoPRO (P<.0001) and the AMPPRO scores (P<.0001) distinguished among the 4 Medicare functional classification levels. The AMP correlated strongly with 6-minute walk scores (AMPnoPRO r=.69, P<.0001; AMPPRO r=.82, P<.0001) and the amputee activity survey (AMPnoPRO r=.67, P<.0001; AMPPRO r=.77, P<.0001), and negatively correlated with age (AMPnoPRO r=-.69, P<.0001; AMPPRO r=.56, P<.0001) and comorbidity (AMPnoPRO r=-.43, P<.0001; AMPPRO r=.38, P<.0001). CONCLUSION: The AMP with and without a prosthesis are reliable and valid measures for the assessment of functional ambulation in lower-limb amputee subjects.     

Incidental intracranial hemorrhage after uncomplicated birth: MRI before and after neonatal heart surgery

We investigated the prevalence of intracranial hemorrhage (ICH) before and after neonatal heart surgery. We carried out pre- and postoperative MRI looking for brain lesions in 24 full-term newborns with known congenital heart disease. They underwent heart surgery with cardiopulmonary bypass (CPB), usually with deep hypothermic circulatory arrest (DHCA). The first MRI was 1-22 days after birth. There were 21 children born after uncomplicated vaginal delivery and three delivered by cesarean section (CS). ICH was seen in 13 (62%) of the vaginal delivery group but in none of the CS group. We saw subdural bleeding along the inferior surface of the tentorium in 11 (52%) and supratentorially in six (29%) of the 21 children with ICH. Small hemorrhages were present in the choroid plexus in seven (33%), in the parenchyma in one (5%) and in the occipital horn in one (5%). There were 26 foci of bleeding in these 21 patients (1.2 per patient). None was judged by formal neurologic examination to be symptomatic from the hemorrhage. Follow-up MRI after cardiac surgery was obtained in 23 children, showing 37 foci of ICH (1.6 per patient), but all appeared asymptomatic. Postoperatively, ICH had increased in 10 children (43%), was unchanged in seven (30%) and was less extensive in six (26%).     

Cytotoxic effect of conjugates of doxorubicin and human chorionic gonadotropin (hCG) in breast cancer cells

Cytotoxic activity of drug conjugates of human chorionic gonadotropin (hCG) and doxorubicin alone was investigated compared to doxorubicin in breast cancer cells with and without expression of hCG receptors. Expression of hCG receptor was determined in MCF-7 and MB231 breast cancer cell line using a multiplex nested rt-PCR approach. The entire sequence of mRNA encoding for hCG receptor was detected in MCF-7 but not in MB231 breast cancer cell line. Cytostatic effect of doxorubicin–hCG conjugates was investigated in these cell lines in comparison to unconjugated doxorubicin. The number of viable cells was determined after 24, 48, 72, 96, and 120 h. To exclude non-specific uptake of the carrier hCG from the culture media, a similar experiment was performed with albumin–doxorubicin conjugates. The number of viable cells decreased in a concentration depending manner after doxorubicin and hCG–doxorubicin conjugate treatment. However, the cytotoxic effect of hCG–doxorubicin conjugate was 10-fold increased compared to unconjugated doxorubin in hCG-receptor positive MCF-7 but not in hCG-receptor negative MB231 cells. Albumin–doxorubicin conjugates showed no increased toxicity compared to doxorubicin. We conclude that the cytotoxic effect of hCG–doxorubicin conjugates is mediated specifically via the hCG receptor. By using hCG conjugates, the development of more selective cytostatics can be achieved.     

Standardized extracts of flavonoids increase the viability of PC12 cells treated with hydrogen peroxide: effects on oxidative injury

Oxidative stress plays an important role in cell death associated with many diseases. In the present study, concentration-dependence of hydrogen peroxide on rat pheochromocytoma (PC12) cell viability was studied. Preventive effects of antioxidants on the viability of these cells treated with 2 mM hydrogen peroxide were compared. Trolox and Stobadine, as chain-breaking antioxidants were studied in comparison with standardized extracts of flavonoids of Ginkgo biloba and Pycnogenol, known as agents effective in several diseases. All antioxidants increased the viability of hydrogen peroxide-treated PC12 cells. Flavonoid extracts were more effective than Trolox and Stobadine. Antioxidants were most effective if present after the oxidative treatment. As expected, the preloading with antioxidants was without effect on cell viability. Correlations between viability increase induced by antioxidants, and content of oxidation products of proteins and lipids were studied at concentrations of antioxidants mostly effective in preventing cell death: Trolox (10 microM), Stobadine (30 microM), Ginkgo biloba (160 microg/ml), Pycnogenol (100 microg/ml). In these concentrations, antioxidants did not statistically significantly decrease the content of protein carbonyls, with exception of Stobadine, which had no effect. Ginkgo biloba, Trolox and Stobadine intensively decreased the content of malondialdehyde, a product of lipid peroxidation. Pycnogenol was without any preventive effect. Concentrations of antioxidants with a large effect on viability of PC12 cells were not effective in preventing oxygen radical-induced injury of proteins. Antioxidants prevented the oxidative injury of lipids more effectively than that of proteins.     

Experimental intrahepatic portacaval anastomosis: use of expandable Gianturco stents

Original Gianturco expandable stents and their modifications were used to create an experimental intrahepatic portacaval anastomosis (EIPCA) in 30 young domestic swine without portal hypertension. The study focused on the design of a suitable stent, the technique of its application, and the evaluation of short-term patency of the EIPCA. A stent with a 2.5-cm-long body and wire skirts on both ends was most suitable for EIPCA creation. Well-positioned stents shunted most of the portal blood in the inferior vena cava circulation and remained patent for 4-6 weeks. Ingrowth of liver parenchyma and abundant proliferation of the intima and connective tissue inside the stent lumen in these rapidly growing animals gradually decreased EIPCA patency, and thrombus formation with diminished blood flow closed them completely.