Clinical features and preliminary studies of virological correlates of neurocognitive impairment among HIV-infected individuals in Nigeria.

In Nigeria, the incidence and prevalence of human immunodeficiency virus (HIV)-related neurocognitive impairment (NCI) are unknown and there currently exists little information related to the viral correlates rates of NCI. Therefore, studies were performed to examine the potential utility of applying an established neuropsychological (NP) screening battery and detailed NP testing to detect NCI and correlations with functional impairment and the presence of specific viral signatures among infected subjects. A total of 60 HIV-1 seropositive antiretroviral-naive individuals and 56 seronegative control subjects were administered the International HIV Dementia Scale (IHDS) and assessed for functional impairment using the Karnofsky performance status scale. Fifteen HIV-infected patients and 11 controls were also administered a detailed NP battery. Blood samples from eight infected subjects, three with evidence of NCI, were obtained for molecular analysis of HIV-1 strain. Unadjusted scores on the IHDS showed that, using a recommended total score cutoff of 10, 28.8% of the HIV-1 seropositive and 16.0% of seropositive individuals scored abnormally. Results from testing using the full NP battery showed that, overall, the HIV seropositive group performed worse than the seronegative group, with effect sizes spanning from small (0.25 on the trail making test A) to large (0.82 on action fluency), and an average effect size across the battery of 0.45, which approaches that which has been recorded in other international settings. Sequencing of partial pol amplicons from viral isolates revealed that two of three patients with NCI were infected with subtype G virus and 1 with the circulating recombinant form (CRF)02_AG; all four individuals without NCI were infected with CRF_02AG. These studies demonstrate the utility of the IHDS in identifying cognitive impairment among HIV infected individuals in Nigeria. Future studies aimed at examining the burden of NCI among the population of individuals with HIV-1 infection in Nigeria and which assess the virologic correlates will contribute to the evolving understanding of the pathogenetic factors that underlie this disorder.

Solvent effect in sonochemical synthesis of metal-alloy nanoparticles for use as electrocatalysts.

Nanomaterials are now widely used in the fabrication of electrodes and electrocatalysts. Herein, we report a sonochemical study of the synthesis of molybdenum and palladium alloy nanomaterials supported on functionalized carbon material in various solvents: hexadecane, ethanol, ethylene glycol, polyethylene glycol (PEG 400) and Ionic liquids (ILs). The objective was to identify simple and more environmentally friendly design and fabrication methods for nanomaterial synthesis that are suitable as electrocatalysts in electrochemical applications. The particles size and distribution of nanomaterials were compared on two different carbons as supports: activated carbon and multiwall carbon nanotubes (MWCNTs). The results show that carbon materials functionalized with ILs in ethanol/deionized water mixture solvent produced smaller particles sizes (3.00 ±â€¯0.05 nm) with uniform distribution while in PEG 400, functionalized materials produced 4.00 ±â€¯1 nm sized particles with uneven distribution (range). In hexadecane solvents with Polyvinylpyrrolidone (PVP) as capping ligands, large particle sizes (14.00 ±â€¯1 nm) were produced with wide particle size distribution. The metal alloy nanoparticles produced in ILs without any external reducing agent have potential to exhibit a higher catalytic activity due to smaller particle size and uniform distribution.

Aprotinin decreases exposure to allogeneic blood during primary unilateral total hip replacement.

BACKGROUND: Aprotinin, a hemostatic agent, regulates fibrinolysis, modulates the intrinsic coagulation pathway, stabilizes platelet function, and exhibits anti-inflammatory properties through inhibition of serine proteases, such as trypsin, plasmin, and kallikrein. Aprotinin has been used successfully for many years in cardiac operations, and there have been preliminary investigations of its use in hip replacement operations. The objectives of this multicenter, randomized, placebo-controlled, double-blind trial were to evaluate the efficacy and safety of aprotinin as a blood-sparing agent in patients undergoing an elective primary unilateral total hip replacement and to examine its effect on the prevalence of deep-vein thrombosis in this population. METHODS: Seventy-three patients received a placebo; seventy-six patients, a low dose of aprotinin (a load of 500,000 kallikrein inhibitor units [KIU]); seventy-five, a medium dose of aprotinin (a load of 1,000,000 KIU, with infusion of 250,000 KIU per hour); and seventy-seven patients, a high dose of aprotinin (a load of 2,000,000 KIU, with infusion of 500,000 KIU per hour). The end points for the determination of efficacy were transfusion requirements and blood loss. Patients received standard prophylaxis against deep-vein thrombosis and underwent compression ultrasonography with color Doppler imaging of the proximal and distal venous systems of both legs to evaluate for the presence of deep-vein thrombosis. RESULTS: Aprotinin reduced the percentages of patients who required any form of blood transfusion (47 percent of the patients managed with a placebo needed a transfusion compared with 28 percent of those managed with low-dose aprotinin [p = 0.02],27 percent of those managed with high-dose aprotinin [p = 0.008], and 40 percent of those managed with medium-dose aprotinin [p = 0.5]). Only 6 percent (twelve) of the 212 patients treated with aprotinin required allogeneic blood compared with 15 percent (ten) of the sixty-eight patients treated with the placebo (p = 0.03). Aprotinin decreased the estimated intraoperative blood loss (p = 0.02 for the low-dose group, p = 0.04 for the medium-dose group, and p = 0.1 for the high-dose group), the measured postoperative drainage volume (p = 0.4 for the low-dose group, p = 0.006 for the medium-dose group, and p = 0.000 for the high-dose group), and the mean reduction in the hemoglobin level on the second postoperative day (thirty-four grams per liter for the placebo group, twenty-eight grams per liter for the low-dose group [p = 0.000], twenty-six grams per liter for the medium-dose group [p = 0.000], and twenty-three grams per liter for the high-dose group [p = 0.0001). The rate of deep-vein thrombosis was similar for all groups. CONCLUSIONS: We concluded that aprotinin is safe and effective for use as a hemostatic agent in primary unilateral total hip replacements. In patients who are at high risk of receiving allogeneic blood, use of aprotinin may be of particular clinical and economic benefit.

Comparison of enoxaparin and warfarin for the prevention of venous thromboembolic disease after total hip arthroplasty. Evaluation during hospitalization and three months after discharge.

BACKGROUND: Venous thromboembolic disease in the form of deep venous thrombosis and pulmonary embolism is a major risk after a total hip arthroplasty. Enoxaparin, a low-molecular-weight heparin, has been shown to reduce the prevalence of deep venous thrombosis after total hip arthroplasty. Warfarin, an orally administered anticoagulant, has been used historically to reduce the risk of deep venous thrombosis after total hip arthroplasty. METHODS: We compared enoxaparin and adjusted-dose warfarin with respect to their safety and their efficacy in the prevention of clinically important venous thromboembolic disease, defined as distal or proximal deep venous thrombosis or pulmonary embolism, or both, during hospitalization after total hip arthroplasty. We also evaluated the prevalence of complications and mortality from venous thromboembolic disease within three months after discharge. RESULTS: Three thousand and eleven patients at 156 centers were randomly assigned to prophylactic treatment with injection of enoxaparin or oral administration of adjusted-dose warfarin during hospitalization. During the study, fifty-five (3.6 percent) of the 1516 patients who were managed with enoxaparin and fifty-six (3.7 percent) of the 1495 patients who were managed with warfarin had venous thromboembolic disease. Twenty-one patients (0.7 percent), which included four (0.3 percent) of those managed with enoxaparin and seventeen (1.1 percent) of those managed with warfarin (p = 0.0083), had venous thromboembolic disease during hospitalization. After discharge from the hospital, venous thromboembolic disease developed in ninety patients (3.0 percent): fifty-one (3.4 percent) of those managed with enoxaparin and thirty-nine (2.6 percent) of those managed with warfarin. One patient who had been managed with enoxaparin died because of a pulmonary embolism, which was confirmed at autopsy. Three additional patients (one who had been managed with enoxaparin and two who had been managed with warfarin) died, and the deaths were attributed to venous thromboembolic disease; however, no autopsies were performed. Twenty-six patients (0.9 percent) (eighteen managed with enoxaparin and eight managed with warfarin) had clinically important bleeding. CONCLUSIONS: Inpatient programs providing treatment with either enoxaparin (thirty milligrams every twelve hours) or adjusted-dose warfarin for a mean of 7.3 days afforded protection against venous thromboembolic disease, with overall rates of morbidity and mortality of 3.7 and 0.6 percent, respectively, and a very low rate of major bleeding complications (0.9 percent) for three months after total hip arthroplasty. During hospitalization, the patients managed with enoxaparin had a lower rate of venous thromboembolic disease than those managed with adjusted-dose warfarin (p = 0.0083). This benefit was lost after the medication was discontinued, with no difference in the prevalences of venous thromboembolic disease between the two groups at three months after discharge from the hospital.

Intraoperative custom press-fit and standard press-fit femoral components in total hip arthroplasty. A comparison of surgery, charges, and early complications.

A consecutive group of 60 patients who had intraoperative custom press-fit total hip arthroplasties (67 hips; Identifit, Thackray, London, United Kingdom) was compared with a similar group of 60 patients who had standard press-fit arthroplasties (66 hips; McCutchen, Wright Medical Technologies, Arlington, Tennessee) to determine if there were differences in operative time and charges, as well as early complications and early radiographic results. The unilateral intraoperative custom group had an average anesthesia time of 3 hours, 39 minutes, an operating time of 2 hours and 26 minutes, and a blood loss of 725 mL. The averages for the standard group included an anesthesia time of 2 hours, 19 minutes, a surgical time of 1 hour, 25 minutes, and a blood loss of 480 mL. By 6 months after surgery, 49 (73%) in the custom group had subsidence of 2 mm or more, compared with 10 hips (15%) in the standard group. The custom group had 17 early postoperative complications versus 3 in the standard group. The charge for the hospital stay averaged $19,950 for the custom group and $14,322 for the standard group. At the present time, the high incidence of complications and the increased charges make the intraoperative custom hip replacement an unlikely first choice of recommendation.

A safety and efficacy comparison study of two dosing regimens of epoetin alfa in patients undergoing major orthopedic surgery.

Previous studies have demonstrated the efficacy of perioperative Epoetin alfa in decreasing allogeneic transfusion exposure in patients undergoing orthopedic surgery. A randomized, multicenter trial was conducted comparing the safety and efficacy of a weekly Epoetin alfa dosing regimen in patients with hemoglobin levels > or = 10 to < or = 13 g/dL scheduled to undergo major elective orthopedic arthroplasty, with a daily regimen previously shown to be effective. patients on the weekly regimen showed a greater baseline-to-presurgery hemoglobin increase versus the daily regimen group (1.44 +/- 1.029 g/dL versus 0.73 +/- 0.867 g/dL). Moreover, the weekly 600 IU/kg regimen was similar to the daily 300 IU/kg regimen with respect to safety and the avoidance of allogeneic transfusion. These data showed the weekly Epoetin alfa regimen to be at least as efficacious as the daily regimen and more convenient.

A comparison of danaparoid and warfarin for prophylaxis against deep vein thrombosis after total hip replacement: The Danaparoid Hip Arthroplasty Investigators Group.

Orgaran (danaparoid sodium injection) is a novel antithrombotic agent. Early studies suggest that this compound may be beneficial in preventing deep vein thrombosis in predisposed patients. This multicenter, randomized, assessor blinded, clinical trial compared subcutaneous danaparoid with warfarin for the prevention of deep vein thrombosis in patients undergoing hip replacement surgery. Bilateral venography was used to detect thrombi. Patients also underwent follow-up examinations 1, 2, and 3 months after discontinuation of the study to determine the after effects of treatment. Nearly 27% of patients who received warfarin and 14.6% of patients who received danaparoid developed deep vein thrombosis, a risk reduction of 46%. The absolute difference in the incidence of deep vein thrombosis was 12.3% in favor of danaparoid. The incidence of venographically documented proximal deep vein thrombosis was 1.5% for danaparoid and 4.1% for warfarin. These results demonstrate that danaparoid is more effective than warfarin in preventing deep vein thrombosis following hip replacement surgery. The preoperative administration of danaparoid does not increase surgical blood loss compared with warfarin.

Comparison of fixation in the treatment of femoral neck fractures.

Two hundred ninety patients with femoral neck fractures of the Garden Type III or IV were treated during the years 1965 through 1978 using one of four types of internal fixation devices. The results divided the devices into two distinct groups. Those allowing highly stable fixation (Calandruccio compression and Deyerle devices) had a higher rate of union and a higher rate of early complications. Those less stable devices (Smith-Peterson nail with Knowles pins and Knowles pins alone) had lower rates of union and early complication. Although avascular necrosis is recorded, no significant comparison could be made because of the lack of a two-year follow-up study in a significant number of cases.

A ten-year follow-up study of 170 Charnley total hip arthroplasties.

Between 1971 and 1974, 352 low-friction hip arthroplasties were performed on 296 patients using the precise Charnley technique. One hundred seventy hips in 145 patients were followed either for ten years or to the point at which revision of the total hip arthroplasty was made necessary by infection, aseptic loosening, chronic dislocation, or similar complications. The results of this evaluation revealed an overall revision rate to the ten-year level of 8.8% in 171 hips and an infection rate of 1.4% for all 352 cases. Both clinical and radiologic assessments encourage further use of this technique.

Osseointegration of titanium implants in total hip arthroplasty.

Osseointegration is defined as direct contact on the light microscopic level between living bone tissue and the implant. Using titanium screw dental implants in the jaw, a lasting interface under loaded conditions extending over a 20-year follow-up period has been demonstrated. This demonstration brings up the question whether a similar interface can be achieved in total hip arthroplasty (THA) between living bone and a titanium alloy implant under necessitated conditions of immediate loading. Two series of cases are reported. The first series used a femoral, press-fit, titanium alloy component and the second used a press-fit titanium acetabular component and redesigned femoral, press-fit, titanium alloy component. Both demonstrated a high percentage of good to excellent results. Roentgenograms showed that the geometrical changes in the redesigned femoral component gave early indications of a better fixation with loading in valgus, less subsidence, and less evidence of distal stress transfer. A two-and-one-half-year postoperative anatomic specimen study confirmed osseointegration to the press-fit titanium alloy femoral component. Multiple areas of contact between bone and metal without fibrous interposition were seen. Examination by electron microscopy supported the light microscopic findings. These findings support further use of smooth, press-fit titanium components in THAs without the need for porous coating, mesh, or other surface modifications.

Sympathetic nervous withdrawal in the vasodepressor (vasovagal) reaction.

When 40 subjects had 134 ml of blood drawn, 8 of them developed hypotension. These 8 subjects were younger, and when they stood they decreased their systemic arterial pressure, pulse rate and plasma norepinephrine. In contrast, normal subjects increased all these parameters after standing. The fall in plasma norepinephrine suggests a generalized withdrawal of sympathetic nervous tone during vasodepressor reactions. Three subjects maintained a heart rate above 60, but still developed hypotension. Withdrawal of sympathetic tone to the vasculature appears more important than increased vagal tone to the heart in causing hypotension in this reaction.