Prevalence of immune disease in patients with wounds presenting to a tertiary wound healing centre

Chronic leg ulcers are a significant cause of morbidity and mortality and account for considerable healthcare and socioeconomic costs. Leg ulcers are a recognised complication of immune disease, and the purpose of this study was to establish the prevalence of immune disease in a cohort of patients with chronic wounds, and to compare wound outcomes in the subjects with and without immune disease. Retrospective chart review was completed on consecutive patients scheduled with the plastic surgeon in the Georgetown University Center for Wound Healing between 1 January 2009 and 31 March 2009. Of the 520 patients scheduled for appointments, 340 were eligible for inclusion. The prevalence of immune disease was higher than expected with 78 of 340 patients (23%) having associated immune disease. At presentation, wounds in patients with immune disease had a significantly larger mean surface area [33·4 cm(2) (69·05) compared to 22·5 cm(2) (63·65), P = 0·02]. Split thickness skin graft (STSG) and bioengineered alternative tissue (BAT) graft data was available on 177 grafts from 55 subjects. There was a significantly lower response rate to STSG in subjects with immune disease (50% compared to 97%, P = 0·0002), but response rates to BAT were not different. The association between immune diseases and chronic wounds may provide unique insights into pathways of wound healing, and warrants further study.

[Demographic population forecasts: theoretical framework, assumptions, and prediction uncertainty]

Population forecasts are not only highly demanded by scientists, politicians, and economists, but also by the general public. Thereby the wish of the users for only one forecast runs contrary to the uncertainty of the future developments of the population. In the past, but also today, population forecasts were and are predominantly accomplished by applying a deterministic approach: the Cohort Component Method. To counteract the uncertainty of future trends in the demographic processes in fertility, mortality, and migration, different scenarios are applied. Many studies have analyzed ex post the accuracy of past population projections. They show that, in addition to other factors, the time horizon and the level of regional aggregation influence the accuracy of the forecast outcomes. In particular, errors in the assumptions about future trends in fertility, mortality, and migration determine the accuracy of the forecasts. In many cases, these assumptions under- or overestimated the real trends. Progress in the question on uncertainty was made in recent years using a new approach: probabilistic forecasts which include probabilities of future trends in demographic processes.

[Neuroendocrine tumors of the small bowels are on the rise: early tumors and their management]

Neuroendocrine tumors (NETs) of the small bowels are on the rise: in the US they have increased by 300-500% in the last 35 years. At the same time their prognosis has been much improved. Most NETs of the duodenum are nowadays detected "incidentally" and therefore recognized at an early stage. Duodenal NETs that are well differentiated, not larger than 10 mm in greatest dimension and limited to the mucosa/submucosa can be endoscopically resected. In NETs with a size between 10 mm and 20 mm the therapeutic strategy has to be individually discussed. Endoscopic ultrasound is the method of choice to determine tumor size and depth of infiltration. Surgery is indicated for well differentiated duodenal NETs greater than 20 mm, for localized sporadic gastrinomas and for localized poorly differentiated NE cancers. Surgery is also indicated for localized/regional ileal NETs. Advanced ileal NETs with a carcinoid syndrome are treated with stable somatostatin analogs. This treatment also significantly improves the (progression-free) survival in patients with metastatic NETs of the ileum. For optimal NET management tumor biology, type, localization and stage of the neoplasm as well as the individual situation of the patient have to be taken into account.

[Neuroendocrine tumors of the stomach (gastric carcinoids) are on the rise: good prognosis with early detection]

Neuroendocrine tumors (NET) of the stomach are on the rise. In the United States they have increased about tenfold in the last 35 years. Prognosis has been much improved over the last three to four decades. Nowadays most of such NETs are diagnosed at an early stage. Quite often gastric NETs are found incidentally during a gastroscopy, performed for other reasons. Most of the asymptomatic, well differentiated gastric NETs are less than 2 cm in diameter. Conservative management and endoscopic surveillance is adequate for well differentiated, multifocal type 1 or type 2 gastric NETs (gastric carcinoids) of 10-20 mm , unless they are angio-invasive, have infiltrated into the muscularis propria or have metastasized. Endoscopic ultrasound is the method of choice to determine tumor size and depth of infiltration. Surgery is, however, indicated for all NETs larger than 20 mm. For optimal management tumor biology, type and stage of the neoplasm as well as the individual situation of the patient have to be taken into account. Most of the patients can be treated conservatively and be followed up with endoscopic surveillance.

A phase II study of ABT-869 in hepatocellular carcinoma (HCC): Interim analysis

4581

Background: ABT-869 is a novel orally active, potent and selective inhibitor of the vascular endothelial growth factor and platelet derived growth factor families of receptor tyrosine kinases. Results of an interim analysis of a phase 2 trial of ABT-869 in HCC are presented. Methods: An open-label, multicenter phase II trial (M06–879) of oral ABT-869 at 0.25 mg/kg daily in Child-Pugh A (C-PA) or QOD in Child-Pugh B (C-PB) patients (pts) until progressive disease (PD) or intolerable toxicity, is ongoing. Key eligibility criteria included unresectable or metastatic HCC; up to one prior line of systemic treatment; and at least one measurable lesion by computed tomography (CT) scan. The primary endpoint was the progression free (PF) rate at 16 weeks. Secondary endpoints included objective response rate (ORR), time to progression (TTP), progression free survival (PFS) and overall survival (OS). CT scans were assessed centrally and by the investigators; presented results are from central assessment. Results: 44 pts were enrolled from 09/07 to 08/08 at 6 centers internationally, with interim data available for 34 pts. There were 28 C-PA pts (median age, 63.5 y [range, 20- 81]) and 6 C-PB pts (median age, 64.5 y [range, 36–69]) and 73.5% received no prior systemic therapy. For the 19 evaluable C-PA pts included in the per-protocol interim analysis, 8 (42.1%) were progression free at 16 weeks [95% CI 20.3, 66.5]. The estimated ORR was 8.7% [95% CI, 1.1, 28] for the 23 C-PA pts and 0% for the 2 C-PB pts who had at least one post-baseline CT scan reviewed by central imaging. For all 34 pts, median TTP was 112 d [95% CI, 110, -], median PFS was 112 d [95% CI, 61, 168] and median OS was 295 d [95% CI, 182, 333]. The most common adverse events (AEs) for all pts were hypertension (41%), fatigue (47%), diarrhea (38%), rash (35%), proteinuria (24%), vomiting (24%), cough (24%) and oedema peripheral (24%). The most common grade 3/4 AEs for all pts were hypertension (20.6%) and fatigue (11.8%). Most AEs were mild/moderate and reversible with interruption/dose reductions/or discontinuation of ABT-869. Conclusions: ABT-869 appears to benefit HCC patients, with an estimated TTP of 112 days and an acceptable safety profile. Updated results from this ongoing study will be presented.

[Table: see text]

Population pharmacokinetic (PK) analysis of ABT-869 in solid tumors and acute myelogenous leukemia (AML) patients

3567

Background: ABT-869 is an orally bioavailable, potent and specific inhibitor of all vascular endothelial growth factor and platelet derived growth factor family receptor tyrosine kinases. The objectives of this analysis were to understand the population pharmacokinetics of ABT-869 and explore the effect of several demographic/disease state covariates influencing ABT-869 disposition. Methods: A population PK analysis of 181 patients (pts) enrolled in two phase 1 (multiple types of solid tumors and AML) and three phase 2 monotherapy studies (non-small cell lung cancer, hepatocellular carcinoma [HCC] and renal cell carcinoma) was conducted. Approximately 90% of pts received ABT-869 based on body-weight dosing while the remaining pts had flat dosing. Available plasma concentrations obtained after intensive and sparse pre-dose PK sampling were analyzed by population PK using the non linear mixed effects modeling (NONMEM) approach. Potential covariates including body weight, body surface area (BSA), age, sex, creatinine clearance (CrCL) and disease state (HCC vs. non-HCC pts) were tested. Results: The mean body weight of enrolled pts was 71 kg and 57% were Asian, 36% Caucasian and 7% other races. The ABT-869 plasma concentration time profile was well described by a one-compartment model with first order absorption and elimination process. Oral clearance (CL/F) was not affected by body weight (range 35–177 kg); however, apparent volume of distribution (V/F) increased by 6L per 0.1 mg/m2 increase in BSA. CrCL (39.9–290.3 ml/min) was not a significant covariate on V/F and CL/F suggesting renally impaired pts do not require a different dose/dosing regimen. HCC pts had ∼40% lower CL/F values than pts with other malignancies suggesting a lower dose would be appropriate for HCC (Child Pugh A and B) pts. Conclusions: Population PK analysis showed that ABT-869 PK can be well described by a one-compartment model with first order absorption and elimination. Race and impaired renal function does not appear to alter PK. HCC pts had lower CL/F value therefore a lower dose may be recommended in these patients. Implications of increased V/F with increasing body size and appropriate dosing strategy are undergoing further analysis.

[Table: see text]

ABT-869 in non-small cell lung cancer (NSCLC): Interim results

8074

Background: ABT-869 is a novel orally active, potent and specific inhibitor of vascular endothelial growth factor and platelet derived growth factor receptor tyrosine kinases. Methods: This ongoing, open-label, randomized, multicenter phase 2 trial of ABT-869 at 0.10 mg/kg daily (Arm A) and 0.25 mg/kg daily (Arm B) until progressive disease (PD) or intolerable toxicity, was initiated to assess antitumor activity and toxicity of ABT-869 in patients (pts) with NSCLC. Eligibility criteria included locally advanced or metastatic NSCLC; ≥ 1 prior systemic treatment, and ≥1 measurable lesion by RECIST criteria. The primary endpoint was the progression free (PF) rate at 16 wks. Secondary endpoints were objective response rate (ORR), time to progression (TTP), progression free survival (PFS) and overall survival (OS). CT scans were assessed by the investigator and centrally; central assessment results are provided. Results: 138 patients (pts) were enrolled from 08/07–10/08 from 27 centers with interim data available for 94 pts (Arm A, n=43; Arm B; n=51). Median age was 64 years and 62 years in Arm A and B respectively. For the interim analysis population (Arm A, n=24; Arm B, n=24), 16 (33.3%) pts were PF at 16 wks: 7 (29.2%) in Arm A and 9 (37.5%) in Arm B. The ORR in Arm A (n=30) was 0% and 7.3% in Arm B (n=41). The median TTP and median PFS were 110 and 109 days, and 112 days and 108 days in Arm A and B, respectively. The most common adverse events (AEs) in Arm A were fatigue (35%), nausea (21%), and anorexia (21%), and in Arm B were hypertension (51%), fatigue (51%), diarrhea (43%), anorexia (41%), nausea (31%), proteinuria (31%) and vomiting (26%). The most common grade 3/4 toxicities in the Arm A were fatigue (7%), ascites (5%), dehydration (5%), pleural effusion (5%), and in the Arm B were hypertension (23%), fatigue (8%), PPE syndrome (8%), dyspnoea (6%) and stomatitis (6%). Most AE's were mild/moderate and reversible with interruptions/dose reduction/or discontinuation of ABT-869. Conclusions: ABT-869 demonstrates an acceptable safety profile and appears to be active in NSCLC patients.

[Table: see text]

How to make a hospital-based wound center financially viable: the Georgetown University Hospital model

As the medical need and expenditure for chronic wound care have increased markedly over the past decade, wound centers have grown exponentially throughout the country. They can be community-based or hospital-based, and in either case, can be run by the facility or by a national chain. The wound center's viability is dependent on generated revenue, and its clinical effectiveness is based on a multidisciplinary approach to wound care. By incorporating the wound center into an existing hospital system, one can take advantage of the hospital's resources to effectively treat the more complex patients. Additionally, by focusing on limb salvage, the hospital attracts the critical limb ischemia and other complex patients that often require inpatient admission. We examined the Georgetown University Hospital Center for Wound Healing performance over the first 6 years of operation. Since opening the wound center in 1999, the number of outpatient visits has doubled, the wound care inpatient census has doubled, and the operative cases have increased 3-fold. Because the outpatient segment of the wound center can at best cover its direct cost, it cannot financially justify its existence. Hyperbaric oxygen (HBO) can increase the revenue to the point where the indirect costs are covered as well and the wound center can be revenue neutral. Due to the medical complexity of limb salvage patients, the inpatient collections are much higher than those of the outpatient wound center and therefore can serve as justification for the latter's financial viability. More importantly, with the wound center in place, the hospital can provide the local/regional community with a comprehensive service that can effectively treat the most challenging wounds. The success is built on a multidisciplinary team approach, use of evidence-based treatment protocols, efficient clinical structure, and a supportive hospital system. The beneficiaries include the patient with a healed wound, the physician with a gratifying practice, the health care system with lower costs, and the hospital with a steady influx of complex patients.

Early results of balloon dilatation of the stenotic bovine jugular vein graft in the right ventricular outflow tract in children

The aim of this study was to evaluate the early results of interventional balloon dilatation of stenotic bovine jugular vein (BJV) grafts implanted for reconstruction of the right ventricular outflow tract (RVOT) in children.

METHODS

From May 2001 to December 2005, 153 BJV grafts were implanted in children in our institution. An average of 16.9 (7.6-41.1) months after implantation, 17 balloon dilatations in a significant stenosis proximal (n = 1), distal anastomosis (n = 8), BJV valve (n = 3), or at multiple sites (n = 5) were performed in 15 children (male:female = 9:6) with a mean age of 3.9 (0.8-13.0) years. Balloon diameter was 75-133.3% (mean 100.3) of the original BJV size. Mean follow-up was 8.8 (2 days to 22.8 months) months.

RESULTS

In 10 interventions (58.8%) the instantaneous peak gradient was reduced below 50 mmHg. A balloon diameter > or =100% of the original BJV size correlated significantly with a successful intervention. No major complications, two minor (nonobstructive floating membranes at the dilatation site and one septicemia) occurred afterward. Freedom from reintervention after 6 months was 58.2% for all, 77.8% for dilatations of the proximal anastomosis and mixed stenotic lesions, and 33.3% for the distal anastomosis.

CONCLUSION

Balloon dilatation of stenotic BJV grafts is safe and can significantly reduce the pressure gradient in two-thirds of interventions. Balloon diameters above the original graft size should be aimed for. The most frequent stenosis of the distal anastomosis tends to renarrow early after dilatation. Nevertheless, balloon dilatation should be considered in nearly every stenotic graft to gain time until a surgical or interventional graft exchange.

[Coincidental squamous cell cancers of the esophagus and head and neck: risk and surveillance]

Patients suffering from head and neck cancer (HNC) have or will develop a second esophageal squamous cell cancer (ESCC) in 5 - 14 %. When a second esophageal neoplasm occurs in a HNC patient, the prognosis is generally determined by the ESCC, and unfortunately it is poor. Prospective clinical studies in Japan, Brazil, Taiwan, France and Germany have shown that screening or surveillance using Lugol chromoesophagoscopy enables early detection of second esophageal neoplasias. Such a surveillance results in a survival benefit for HNC patients. Vice versa, ESCC patients also have a risk of 9.3 - 11.4 % for a head and neck cancer. Periodic otolaryngeal examination and pharyngoscopy is recommended for curatively treated ESCC patients. Patients with a so-called field cancerisation of the airways and upper digestive tract thus require an interdisciplinary management and monitoring.

Results of a phase III randomized controlled trial of the safety and efficacy of atrasentan in men with nonmetastatic hormone-refractory prostate cancer (HRPC)

5018

Introduction: Atrasentan is a potent oral, selective endothelin A receptor antagonist with biological activity in patients with HRPC. This randomized phase III trial of atrasentan vs placebo was conducted in 941 men with nonmetastatic HRPC whose prostate-specific antigen (PSA) was rising despite adequate androgen suppression. Methods: 467 patients were randomized to receive atrasentan 10 mg and 474 patients were randomized to receive placebo daily. Primary efficacy endpoints were time to disease progression (TTP) and progression-free survival, with progression defined as the onset of metastases. Secondary endpoints were overall survival, time to PSA progression, change from baseline in bone alkaline phosphatase (BAP), and PSA doubling time (PSADT). Results: In the intent-to-treat population, median TTP was 764 days with atrasentan and 671 days with placebo (hazard ratio [HR], 0.915; G1,1 P=0.288). More placebo- treated patients (267, 56.3%) than atrasentan-treated patients (227, 48.6%) experienced disease progression. Overall, 278 patients (29.5%) discontinued before reaching a protocol-defined endpoint (155, 40.8% US vs 123, 21.6% non-US). More placebo-treated patients (210, 44.3%) than atrasentan-treated patients (169, 36.2%) experienced new skeletal lesions. Median survival was 1,477 days for the atrasentan group and 1,403 days for the placebo group (HR, 0.909; G1,1 P=0.176). Mean change from baseline to final BAP was -1.51 IU/L with atrasentan compared with +2.20 IU/L with placebo (P<0.001). PSADT was lengthened with atrasentan relative to placebo (P<0.031). The incidence of peripheral edema, nasal congestion, headache, dyspnea, anemia, and heart failure was significantly greater in the atrasentan group (P<0.05). Most of these events were mild and nonserious and did not result in study discontinuation. Conclusions: Data from this study did not show a statistically significant difference in time to progression between atrasentan and placebo. However, the high discontinuation rate, especially among US patients, may have compromised the ability of the study to accurately determine the treatment effect of atrasentan in this population.

No significant financial relationships to disclose.

[Increased incidence of hepatocellular and intrahepatic cholangiocellular carcinoma in northeast Germany]

BACKGROUND AND OBJECTIVE

Hepatocellular cancer (HCC) is one of the five most common cancers worldwide. In Western countries the incidence of both HCC and intrahepatic cholangiocellular cancer (iCCC) has increased quite dramatically in the last 20 years. It was the aim of this study to assess the epidemiological changes of both cancers in the Northeast of Germany.

METHODS

Using the data base of the Joint German Cancer Registry of the New Federal States and of Berlin, the age- and world-population-adjusted incidence of HCC and iCCC and their 5-year survival were calculated. The states of Brandenburg, Mecklenburg-Vorpommern and Saxony were chosen for this study because of the high quality of their registration base.

RESULTS

In men the age-adjusted incidence of HCC increased from 3.6 in 1976 to 5.7 in 2002, the absolute number of newly diagnosed HCCs rising from 192 to 383 males within this period. In women the incidence was much lower. While only 30 males and 36 females were diagnosed with iCCC in 1976, in 2002 there were 64 men and 75 women with iCCC. In 1976, the corresponding age-adjusted incidence was 0.5 in men and 0.4 in women. Up to 2002 the incidence of iCCC rose to 0.8 and 0.6, respectively. The cumulative 5-year survival of HCC and iCCC was less than 10% for each. Comparison of the early period (1978-1979) with the later one (1998-1999) demonstrated a statistically significant improvement in survival for HCC. This was most likely due to earlier diagnosis and treatment of HCC.

CONCLUSION

In the Northeast of Germany the incidence of both HCC and iCCC have increased markedly in the last 20 years. The recently improved survival of HCC patients most likely reflects earlier diagnosis and treatment.

Pharmacokinetics (PK), safety and tolerability of atrasentan (ABT-627, ATN) in combination with docetaxel (DOC) in men with hormone refractory prostate cancer (HRPC)

14512

Background: ATN (Xinlay) is an oral selective endothelin A receptor antagonist in Phase III clinical development for the treatment of HRPC. ATN is extensively metabolized by oxidation and glucuronidation. In vitro, CYP3A is the predominant isozyme involved in oxidative metabolism of ATN and DOC; ATN inhibits CYP3A with an IC50 of ∼3 μM (15-fold the mean plasma Cmax for 10 mg/d ATN). Methods: 11 men with HRPC received DOC 75 mg/m2 by 1-h IV infusion on day (D) 1 of each 21-D cycle (C), and ATN 10 mg po qd starting D8C1 and prednisone(Pred) 5 mg orally twice daily.Three oral doses of dexamethasone 8 mg were administered starting 12 hours before DOC. On coadministration days, ATN was taken at the start of the DOC infusion. PK were to be determined over 24 h following DOC alone (D1C1) and in combination with ATN (D1C2), and following ATN alone (D20C1) and in combination with DOC (D1C2). Plasma concentrations of ATN and DOC were determined using a validated LC/MS/MS method. Results: Preliminary PK results are summarized (N = 10, mean ± SD) in the table below. Some patients (pts) had D1C2 PK performed D1C4 (N = 4), D1C5 (N = 3) or not at all (N = 1). No unexpected adverse events (AE) were observed. One subject experienced neutropenic fever related to DOC. This resolved with treatment and ATN/DOC was resumed. Efficacy: 3/5 DOC naive and 2/6 DOC resistant pts had a >50% post treatment PSA decline. One DOC resistant pt demontrated post treatment calcicfication of liver metastases accompanied by a >45% PSA decline. Conclusions: No PK interaction was observed between ATN and DOC when coadministered at full standard single agent dosages implying 10 mg QD ATN did not alter CYP3A4 activity in gut or liver. Treatment with ATN/DOC was well tolerated and demonstrated activity in DOC resistant pts, further justifying a planned Southwest Oncology Group phase III study comparing ATN/DOC/Pred to DOC/Pred. [Table: see text]

[Table: see text]

[Pseudoaneurysm of the left hepatic artery as a complication of ERCP with sphincterotomy]

A pseudoaneurysm of the hepatic artery is a rare complication of interventional endoscopy or transhepatic puncture. The present case report describes a symptomatic pseudoaneurysm of the left hepatic artery following endoscopic retrograde cholangio-pancreatography (ERCP). The indication was a biliary pancreatitis, and it was treated by guide-wire-sphincterotomy and extraction of sludge with a Dormia basket. A superselective angiographic embolization was not necessary because of a spontaneous thrombotic obstruction of the pseudoaneurysm.

Clinical Approach to Wounds: D??bridement and Wound Bed Preparation Including the Use of Dressings and Wound-Healing Adjuvants

This is a clinical review of current techniques in wound bed preparation found to be effective in assisting the wound-healing process. The process begins with the identification of a correct diagnosis of the wound's etiology and continues with optimizing the patient's medical condition, including blood flow to the wound site. Débridement as the basis of most wound-healing strategies is then emphasized. Various débridement techniques, including surgery, topical agents, and biosurgery, are thoroughly discussed and illustrated. Wound dressings, including the use of negative pressure wound therapy, are then reviewed. To properly determine the timing of advance therapeutic intervention, the wound-healing progress needs to be monitored carefully with weekly measurements. A reduction in wound area of 10 to 15 percent per week represents normal healing and does not mandate a change in the current wound-healing strategy. However, if this level of wound area reduction is not met consistently on a weekly basis, then alternative healing interventions should be considered. There is a growing body of evidence that can provide guidance on the appropriate use of such adjuvants in the problem wound. Several adjuvants are discussed, including growth factor, bioengineered tissues, and hyperbaric medicine.

Best-practice algorithms for the use of a bilayered living cell therapy (ApligrafR) in the treatment of lower-extremity ulcers

Tissue-engineered skin substitutes such as Apligraf have emerged over the past 20 years as among the most carefully studied and efficacious of the advanced wound modalities. These products have been proven as effective enhancements to general wound care, promoting wound closure particularly in instances where conventional wound care fails. Marketed for hard-to-heal wounds since 1998, Apligraf has become part of standard wound care in many wound centers across the United States. Despite this situation, few general wound care guidelines incorporate advanced and active wound-healing technologies, such as tissue-engineered skin products. Because of this deficiency, appropriate patient selection and proper use of these product remain largely unaddressed within the general wound care community. Here, we describe the development of guidelines surrounding optimal use of the bilayered living cell therapy, Apligraf, in the treatment of the two types of lower extremity ulcers for which the product is FDA approved: venous leg ulcer and diabetic foot ulcer. The guidelines detailed in this article focus on the identification and selection of patients who are at risk for failure of standard wound care therapy and thus appropriate for Apligraf treatment. The intended audience for these guidelines is the general wound care practitioner, for whom the developed treatment algorithms and accompanying figure legends should provide practical, user-friendly direction simplifying both patient selection and appropriate use of Apligraf within the context of good wound-healing practice.

AIDS prevention is thicker than blood. Zimbabwe

Usually, giving blood is generous. Sometimes, however, it is lethal. In countries such as the US, India and Brazil, where blood donors can get paid by the pint, drug addicts, street dwellers and others who have little to sell except their bodies flock to for-profit blood centers. Many of these people carry the AIDS virus. A survey in the Indian state of Maharashtra revealed that 27% of blood donors tested positive for AIDS antibodies--a slightly higher rate than the same survey found among prostitutes. If 1 private blood bank tests for AIDS antibodies and turns HIV-positive volunteers away--forget about treating them--those poor and desperate enough can often find another, less scrupulous clinic. Or a clinic that doesn't do the testing properly. Although the 1988 Brazilian constitution banned the sale of blood, private clinics continue to flourish and nobody knows whose veins the blood is flowing from. The inevitable result is a frightening rate of contamination. An estimated 85% of Brazilian hemophiliacs have become infected with the HIV virus by contaminated blood or blood products. Even in countries that eschew blood sales and rely on donated supplies, the danger of HIV contamination is still present. HIV infection often does not generate antibodies for weeks; sometimes months or even years. In many 3rd World communities without adequate equipment, blood storage is impossible. The cost of testing emergency donations is so high that the choice may be narrowed--either go without testing or do without blood. Despite all these obstacles, Zimbabwe has shown that a 3rd World country where public health care takes precedence over private profit can make the blood supply network a force for reducing the spread of AIDS rather than increasing it. All blood donations in Zimbabwe were voluntary even before AIDS became an issue. When AIDS was accorded recognition as a serious issue, the country had no clinic for HIV testing. Concerned with the rapid spread of AIDS among the general population, the National Blood Transfusion Service (NBTS) began testing in 1985. Zimbabwe was the 3rd country in the world to begin routine testing. The NBTS is a nonprofit organization headed by representatives from the ministry of health, the Red Cross, and private donors. Because the NBTS was the only group in the country testing blood, many people who suspected they might be infected volunteered to donate blood just so they could have the test. Unfortunately, their suspicions were often justified. The service has found that regular donors now have a far lower incidence of HIV-positive since 1989, when alternative testing services were opened. Analysts believe much of the credit goes to the AIDS counseling given before each blood donation. Each individual is interviewed by a nurse who takes a comprehensive medical history. The education session also includes how AIDS might be contracted. The NBTS quickly discovered that the incidence of HIV antibodies was far lower among students aged 17-19. Since then, the service has thrown much of its resources into school blood campaigns. The service has also opened 5 new collection branches, 1 in each province. Samples from each donation are sent to 1 of the 2 national centers for testing. AIDS is still spreading in Zimbabwe, but thanks to the efforts of NBTS, hospital patients can feel secure.

Evidence of increased matrix metalloproteinase-9 concentration in patients following cardiopulmonary bypass

Cardiopulmonary bypass (CPB) is associated with a systemic inflammatory response, which can result in acute lung injury known as "postperfusion syndrome." Neutrophil activation with concomitant serine protease release has been implicated in the pathogenesis of "postperfusion syndrome." Increased plasma levels of neutrophil elastase (NE) have been demonstrated in patients undergoing CPB, and it is well documented that both NE and matrix metalloproteinase-9 (MMP-9) have a synergistic role in pulmonary injury. We, therefore, hypothesized that plasma levels of MMP-9 would be elevated in patients after CPB. Human plasma was obtained after informed consent from eight patients undergoing CPB. Plasma was collected at the start of CPB, 5 minutes after the initiation of CPB, and at the termination of CPB (156 +/- 17 min). All samples were analyzed by both standard enzyme-linked immunosorbent assay (ELISA) and gelatin zymography for MMP-9 (free and total enzyme) concentration. Data were expressed as means +/-SE and assessed by analysis of variance (ANOVA). Plasma MMP-9 concentration was significantly increased at the end of CPB (191 +/- 30.4 ng/mL; p <.05) as compared to both the start of CPB (28.3 +/- 13.2 ng/mL) and 5 minutes after the initiation of CPB (44.3 +/- 15.4 ng/mL). Patients undergoing CPB show an increase in serum MMP-9 levels. Prior studies utilizing an animal model of "postperfusion syndrome" have shown that inhibition of MMP-9 and NE prevented pulmonary injury following CPB. The results of the current study suggest that such an approach may also have merit in the clinical setting of cardiopulmonary bypass.

Depression, cognitive impairment and function in Alzheimer's disease

Depression is very common in patients with dementia but the relationship is very complex. Depression is regarded as a cause of excess disability in persons with dementia and contributes to their functional decline. The assessment of depression in dementia patients, however, has been difficult in that the validity of self-reported depression in patients with dementia has been questioned. This study was done to investigate whether self-reported depression by persons with dementia (using the GDS) is related to their functional abilities as rated by a family caregiver (using the IADL scale) above and beyond demographic variables. This study was conducted at the Detroit Satellite of the Michigan Alzheimer's Disease Research Center. There were 141 participants, 67% were African American and 33% were European American. Statistical analyses included a correlational and multiple regression approach to determine the predictive relationships of cognitive and depressive symptoms above and beyond the influence of demographic variables and cognition. The results of the study further support the notion that depression in dementia is significantly related to functional decline but, more importantly, that self-reported depression in patients with dementia can be valuable information in understanding patients' functioning.

Detection of isolated hook fractures 36 months after implantation of the Ancure endograft: a cautionary note

Two cases of delayed (36-month) Ancure hook fracture are reported in patients who experienced a decrease in aneurysm size and no evidence of endoleak. Both devices used redesigned hooks and are otherwise identical to those devices currently used in clinical practice. Notably, hook fractures were not visualized on all abdominal radiographic views, nor were they noted on the final "institutional" report by the reviewing radiologist. Careful clinical follow-up with multiple-view abdominal radiographs remains essential for all patients treated with an endovascular graft, with particular attention directed to the integrity of the metal components. The broader clinical significance of this observation with respect to the Ancure endograft remains to be defined.

Metalloproteinase inhibition prevents acute respiratory distress syndrome

BACKGROUND

The acute respiratory distress syndrome (ARDS) occurs in patients with clearly identifiable risk factors, and its treatment remains merely supportive. We postulated that patients at risk for ARDS can be protected against lung injury by a prophylactic treatment strategy that targets neutrophil-derived proteases. We hypothesized that a chemically modified tetracycline 3 (COL-3), a potent inhibitor of neutrophil matrix metalloproteinases (MMPs) and neutrophil elastase (NE) with minimal toxicity, would prevent ARDS in our porcine endotoxin-induced ARDS model.

METHODS

Yorkshire pigs were anesthetized, intubated, surgically instrumented for hemodynamic monitoring, and randomized into three groups: (1) control (n = 4), surgical instrumentation only; (2) lipopolysaccharide (LPS) (n = 4), infusion of Escherichia coli lipopolysaccharide at 100 microg/kg; and (3) COL-3 + LPS (n = 5), ingestion of COL-3 (100 mg/kg) 12 h before LPS infusion. All animals were monitored for 6 h following LPS or sham LPS infusion. Serial bronchoalveolar lavage (BAL) samples were analyzed for MMP concentration by gelatin zymography. Lung tissue was fixed for morphometric assessment at necropsy.

RESULTS

LPS infusion was marked by significant (P < 0.05) physiological deterioration as compared with the control group, including increased plateau airway pressure (P(plat)) (control = 15.7 +/- 0.4 mm Hg, LPS = 23.0 +/- 1.5 mm Hg) and a decrement in arterial oxygen partial pressure (P(a)O(2)) (LPS = 66 +/- 15 mm Hg, Control = 263 +/- 25 mm Hg) 6 h following LPS or sham LPS infusion, respectively. Pretreatment with COL-3 reduced the above pathophysiological changes 6 h following LPS infusion (P(plat) = 18.5 +/- 1.7 mm Hg, P(a)O(2) = 199 +/- 35 mm Hg; P = NS vs control). MMP-9 and MMP-2 concentration in BAL fluid was significantly increased between 2 and 4 h post-LPS infusion; COL-3 reduced the increase in MMP-9 and MMP-2 concentration at all time periods. Morphometrically LPS caused a significant sequestration of neutrophils and monocytes into pulmonary tissue. Pretreatment with COL-3 ameliorated this response. The wet/dry lung weight ratio was significantly greater (P < 0.05) in the LPS group (10.1 +/- 1.0 ratio) than in either the control (6.4 +/- 0.5 ratio) or LPS+COL-3 (7.4 +/- 0.6 ratio) group.

CONCLUSIONS

A single prophylactic treatment with COL-3 prevented lung injury in our model of endotoxin-induced ARDS. The proposed mechanism of COL-3 is a synergistic inhibition of the terminal neutrophil effectors MMPs and NE. Similar to the universal practice of prophylaxis against gastric stress ulceration and deep venous thromboses in trauma patients, chemically modified tetracyclines may likewise be administered to prevent acute lung injury in critically injured patients at risk of developing ARDS.

Operation Everest III (Comex'97): the effect of simulated sever hypobaric hypoxia on lipid peroxidation and antioxidant defence systems in human blood at rest and after maximal exercise

Eight subjects were placed in a decompression chamber for 31 days at pressures from sea level (SL) to 8848 m altitude equivalent. Whole blood lipid peroxidation (LP) was increased at 6000 m by a mean of 23% (P<0.05), at 8000 m by 79% (P<0.01) and at 8848 m by 94% (P<0.01). (All figures are means.) Two days after return to sea level (RSL), it remained high, by 81% (P<0.01), while corresponding erythrocyte GSH/GSSG ratios decreased by 31, 46, 49, 48%, respectively (each P<0.01). Erythrocyte SOD and plasma ascorbate did not change significantly. At sea level, maximal exercise induced a 49% increase in LP (P<0.01), and a 27% decrease in erythrocyte GSH/GSSG ratio relative to resting values (P<0.05). At 6000 m, the LP was enhanced further from 23 (P<0.05) to 66% (P<0.01), and after RSL from 81 (P<0.01) to 232% (P<0.01), while pre-exercise GSH/GSSG ratios did not change significantly. Exercise did not change plasma ascorbate relative to sea level or to 6000 m, but decreased after RSL by 32% (P<0.01). These findings suggest that oxidative stress is induced by prolonged hypobaric hypoxia, and is maintained by rapid return to sea level, similar to the post-hypoxic re-oxygenation process. It is increased by physical exercise.

Effective screening for Alzheimer's disease among older African Americans

Relatively little data exist concerning the utility of brief cognitive measures to detect dementia among African Americans. The current study evaluated the clinical utility of the Mini-Mental Status Exam (MMSE) and the Fuld Object Memory Evaluation (FOME) in detecting Alzheimer's disease (AD) among both African American and European American older adults. One hundred and forty geriatric patients from a large urban academic medical center were examined. Overall, the FOME appeared to be more effective in detecting AD than was the MMSE (93% sensitivity vs. 75% sensitivity, respectively), although both measures suffered from relatively low specificity (63.5) in the full sample. The FOME demonstrated exceptional clinical utility among African American patients (sensitivity 98.3%; specificity = 64.5; positive predictive power 83.8%; negative predictive power 95.2%). The results of this study support the use of the FOME among older African Americans to detect dementia.

Use of a cross-mounting buccal index to help transfer the spatial relationships of an interim prosthesis to the definitive implant-supported prosthesis

This article describes a new method for the fabrication of an index for definitive implant abutment selection, framework design, and fabrication. After the interim removable restoration is esthetically and functionally accepted by the patient and dentist, it can be used as a surgical guide during implant placement as well as a guide for abutment selection, framework design, and fabrication. The concepts used in the fabrication of the cross-mounting buccal index include having a reference point, maintaining the vertical dimension of occlusion, and supplying the ability for cross mounting. This procedure allows the clinician to use a duplicate of the interim restoration to select the abutments and fabricate the framework without a new denture setup. It also accelerates both patient chairtime and laboratory time, and it enhances the prosthodontic outcome.

Satisfaction with Services in Innovative Managed Care Programs for Groups of Traditionally Underserved Individuals with HIV/AIDS: Empirical Models

As the number of people with HIV/AIDS receiving services in managed care models increases, concerns over quality of care and satisfaction with services have grown. This article examined data from three national demonstration projects that were funded to enroll traditionally underserved individuals and provide innovative medical services in programs developing models appropriate for managed care funding. Assessments of patient satisfaction were related to indicators of traditionally underserved status including demographic characteristics, behaviors, and other risk factors using the data modeling method of Exhaustive CHAID (Chi-squared Automatic Interaction Detector). Overall patient satisfaction levels with these programs were very high. Through the modeling methods, the groups most likely to experience the greatest program satisfaction are identified. In general, all groups were highly satisfied with the programs.

Finding the Underserved: Directions for HIV Care in the Future

The demographic, behavior, and background characteristics of 4,804 participants in 17 national demonstration projects for HIV medical and/or psychosocial support services were coded for an index of "service need" or possible under-representation in the traditional healthcare system. Fifteen items were coded including status as a person of color, lack of private insurance, unemployment/disability, problem drinking, crack cocaine use, heroin use, other illicit drug use, less than 12 years of education, criminal justice system involvement, children requiring care while the patient receives services, sex work, being the sex partner of an injection drug user, unstable housing, primary language not English, and age less than 21 or over 55 years. Most (87.7%) of the program participants had four or more of these factors present. Through CHAID modeling, those groups with the highest levels of service need and vulnerability were identified. These data suggest that these projects, designed to attract and serve individuals potentially underrepresented in the health services system, had in fact achieved that goal. Implications of the changing demographics of the HIV epidemic for the health service delivery system are discussed.

An investigation of why eligible patients do not receive HAART

Treatment with highly active antiretroviral therapy (HAART) decreases morbidity and mortality for persons with human immunodeficiency virus/acquired immunodeficiency syndrome (HIV/AIDS) and reduces costs of care. Yet many patients for whom HAART is indicated do not receive it. This study investigated the reasons why certain patients of a community health center with HIV/AIDS did not receive HAART between 1997 and 1998. Medical record reviews were performed to determine which patients for whom HAART was indicated (according to United States Public Health Service guidelines) were not prescribed HAART. Chart reviews and patient interviews were conducted to determine why they did not receive HAART. Of the 88 patients eligible for HAART, 60 (69%) had it prescribed in 1997-1998. Of the remaining 28 patients, 3 did not receive HAART because their provider never discussed it with them. For 6 patients (21%), the provider discussed HAART but did not recommend it; 16 patients (57%) declined HAART although their provider recommended it, and 3 (11%) accepted their provider's recommendation but never started HAART. Patients' most common reasons for refusing HAART were not being ready for strict adherence to a complex regimen (7/16) and fear of side effects (6/16). Other reasons included active drug use, religious beliefs, homelessness, confidentiality concerns, depression, and feeling well without HAART. Providers did not recommend HAART because of active drug use (4/6), lack of engagement with care (2/6) as well as homelessness, depression, and the perception that the patient was doing well without HAART. Providers should be trained to offer all patients the opportunity to develop a plan to address barriers to adherence and the support needed to implement it. Resources should also target the treatment of substance abuse and mental illness to improve the usage of HAART.

Typology of quality of life experiences among persons living with HIV

This article develops a typology of 2,038 participants in 13 innovative HIV/AIDS treatment model service demonstration projects targeted to traditionally underserved populations. The typology is based on self-reported health-related quality of life levels. Eight clusters were identified that classify HIV/AIDS patients based on their reported health-related quality of life. Participants were clustered based on their overall levels of quality of life, as well as by deficits in specific areas of functioning such as energy level, physical impairment, and role impairment. However, factor analysis suggests that health-related quality of life as perceived by the HIV-positive participants is best represented as a single underlying dimension and an ordering of the types shows that they are consistently related, in the same order, to several criterion measures of impairment. The results suggest that a general categorization of patients with HIV in terms of quality of life is more meaningful than an assessment of the relative areas of impairment. Since the impairment ratings were also self-reported, analyses relating quality of life clusters to actual symptom levels and healthcare utilization are needed. Implications for the assessment of health-related quality of life and the evaluation of service delivery programs for persons living with HIV are discussed.

Service needs and factors related to quality of life at time of service enrollment among persons living with HIV

This article explores the relationships of HIV risk factors, service needs, and vulnerabilities to health-related quality of life in a sample of 1,371 participants newly enrolled into 13 innovative HIV/AIDS treatment model service demonstration projects. These projects targeted services to traditionally underserved populations. Eight distinct quality of life clusters of HIV patients were used in this analysis along with patient self-identified risk factors. The quality of life clusters were based on patient self-reported quality of life dimensions. The eight clusters were differentiated based on relative strengths and weaknesses in physical functioning, energy levels, and social functioning. Data on patient need-vulnerability factors and demographic characteristics were related to these eight clusters using the data modeling method of Exhaustive CHAID (Chi-squared Automatic Interaction Detector). Through this method, the characteristics most likely to be associated with higher and lower levels of quality of life at the time of enrollment into services were identified. The results provide further support that quality of life assessment is a useful clinical tool for monitoring patient progress.

Differences in the two-dimensionally measured laser Doppler flow at different skin localisations

The cutaneous microcirculation shows a significant heterogeneity. With high-resolution two-dimensional laser Doppler perfusion imaging (LDPI), spatial and temporal reproducible perfusion measurements can be reached. The objective of this study was the quantification of skin perfusion in 20 defined skin areas with LDPI, in 60 healthy young and old volunteers. The perfusion of the face was significantly higher than that of the trunk and extremities. The highest perfusion values were seen at the lips, 1.47 arbitrary units (AU), followed by the chin (0.99 AU), the nose (0.95 AU), the forehead (0.73 AU) and the cheek (0.72 AU). Mean perfusion, between 0.40 and 0.49 AU, was seen at the extremities and at the trunk. The lowest perfusion was found at the bottom (0.37 AU), on the back of the foot (0.36 AU) and on the soles (0.31 AU). There was a tendency to show higher perfusion values in men than in women (0.60 +/- 0.31 vs. 0.53 +/- 0.26 AU). Age-related differences in perfusion could not be demonstrated. In the evaluation of the perfusion of pathological skin, regional perfusion differences must be considered, whereas moderate age or gender differences between different investigation groups can be tolerated.

The effects of ionotropic agonists of excitatory amino acids on the release of arginine vasopressin in rat hypothalamic slices

The effects of ionotropic excitatory amino acids agonists on the release of vasopressin from rat hypothalamic slices were studied. Incubation with increasing doses of NMDA, kainate or AMPA decreased the release of vasopressin in a dose-dependent manner. The values of the IC50 were 1.0, 9.6, or 3.7 x 10-8 M, respectively. The inhibitory effect of the various excitatory amino acids tested was blocked by coincubation with their respective antagonists. Vasopressin secretion was stimulated to 140.3 +/- 7.6% of controls when the slices were obtained from chronically (7 days) salt-loaded rats. Addition of 1 x 10-7 M NMDA or 1 x 10-6 M kainate to the incubation medium antagonized the salt loading-induced increase in vasopressin release. Incubation with 1 x 10-4 M tetrodotoxin did not change basal vasopressin release, but it blocked the decrease in vasopressin secretion induced by 1 x 10-7 M NMDA or 1 x 10-6 M kainate or 1 x 10-6 M AMPA. Incubation with 1 x 10-5 M phaclophen (a GABAB antagonist) and 1 x 10-5 M bicuculline (a GABAA antagonist) was without effect on basal vasopressin secretion while it reversed the inhibition of vasopressin release induced by 1 x 10-7 M NMDA. Incubation with 1 x 10-6 M GABA alone decreased vasopressin secretion to 64.6 +/- 6.9% of control values. The inhibitory effect of GABA did not change when 1 x 10-7 M NMDA was added to the incubation medium. These findings demonstrate that ionotropic excitatory amino acids agonists inhibit vasopressin secretion from hypothalamic slices. They strongly suggest that this inhibitory effect is mediated through local GABAergic interneurones.

Regional brain bioamine levels under hyperbaric oxygen in two unequally susceptible strains of mice

BACKGROUND

Hyperbaric oxygen (HBO) increases monoamine deamination with related toxic products which aggravates hyperbaric oxygen (HBO) neurotoxicity. However, the possibility of some protective action of monoamines balanced by the toxicity of their metabolites have received little attention.

HYPOTHESIS

To try to unmask this protective action, we compared brain monoamine levels in two strains of mice differing in HBO-sensitivity and their sensitivity to HBO after norepinephrine (NE) depletion by N-(2-chloroethyl)-N-ethyl-2-bromo benzylamine (DSP4).

METHODS

Mice were exposed to 6 ATA O2 for 90 min (C57 strain) and 24 min (HBO-sensitive CD1 strain) so that 50% of mice of each strain had preconvulsive symptoms when decompressed and 50%), had one generalized convulsion. After microwave sacrifice, monoamines in the cerebral cortex, the striatum and the brainstem were analyzed. Another series studied the effect of DSP4 on the delay to symptoms of these HBO)-exposed mice.

RESULTS

NE normoxic levels in the striatum were greater in the HBO-sensitive CD1 than in the C57 strain. Under HBO, NE levels in the striatum and the cortex of CD1 fell without any concomitant increase in its metabolite whereas in the C57 strain, NE decreased less and its metabolite increased. There was no strain difference and little change in the NE levels in the brainstem. The increase in toxicity induced by DSP4 was highly significant in both strains; moreover C57 strain was more affected than CD1.

CONCLUSION

Monoamine depletion before HBO aggravates HBO neurotoxicity. As monoamine deamination is known to be toxic, this demonstrates that monoaminergic activation is protective. The greater toxicity of DSP4 in the C57 strain suggests the involvement of monoamines in the strain-differential susceptibility to HBO. The lower sensitivity of CD1 mice to DSP4 may be related to a combination of less NE activation under HBO that in C57 and greater activation of peroxidation and amino acids in CD1 sensitive strain.

Review of methods to predict and detect atrial fibrillation in post-cardiac surgery patients

Atrial fibrillation (AF) is the most common sustained arrhythmia after cardiac surgery. Postoperative AF is known to substantially lengthen hospital stay and affect patient recovery. Identification of those at risk of developing AF after surgery and early detection of AF during recovery would be extremely helpful in effective management of these patients, including targeting prophylactic therapy to prevent AF in high-risk patients. In this communication, diagnostic methods to identify those at risk of developing AF after surgery and early identification of AF before, during, and after surgery have been reviewed. Signal-averaged P wave analysis, done before surgery, identifies patients who are likely to develop AF during recovery. When combined with low ejection fraction, signal-averaged P wave can discriminate those who develop AF from those who do not. During recovery, AF can be detected early either from a detailed analysis of atrial activity in a 10-second electrocardiogram or an analysis of R-to-R intervals from an extended rhythm strip (1 minute or longer). Analysis of the 10-second electrocardiogram includes median QRST subtraction from rhythm data and detection and analysis of atrial signals in the resulting residual. AF is detected from extended rhythm strips by using a statistical model to identify the presence of characteristic irregular patterns of R-to-R intervals.

Implementing a clinical pathway for congestive heart failure: experiences at a teaching hospital

Clinical pathways are processes of care that use a multidisciplinary team effort to move patients toward a designed outcome. This article details the challenges of a Quality Enhancement and Clinical Resource Management Team in designing and implementing a successful congestive heart failure pathway at a teaching hospital. Academic institutions have the resources as part of their research mission, to enhance the development of clinical pathways and assess their outcomes.

Cytotoxic sensitivity to tumor necrosis factor-alpha in PC3 and LNCaP prostatic cancer cells is regulated by extracellular levels of SGP-2 (clusterin)

BACKGROUND

SGP-2 is a ubiquitous secreted glycoprotein that prevents cellular apoptosis. This study was carried out to determine the extracellular action of SGP-2 in a model of tumor necrosis factor-alpha (TNF)-induced cytotoxicity using two human prostatic cancer lines, LNCaP and PC3. These two lines were selected because LNCaP cells are highly sensitive to the cytotoxic effect of TNF, while PC3 cells are resistant to TNF at 24 hr.

METHODS

Cells were cultured in the presence or absence of TNF (10 ng/ml). LNCaP cells were treated with varying concentrations of exogenous SGP-2, while PC3 cells were treated with antisera to SGP-2 with and without exogenous SGP-2. Following a 24-hr treatment, cultures were assessed by counting of cell number and by the trypan blue exclusion assay.

RESULTS

Western blot analysis of conditioned media revealed that PC3 secreted more SGP-2 than did LNCaP. The sensitivity to TNF in LNCaP cells was reduced by the addition of exogenous SGP-2. PC3 cells became sensitive to TNF when SGP-2 antibody was added to the culture. The effect of SGP-2 antibody on PC3 cells was reversed by the addition of exogenous SGP-2 to the culture.

CONCLUSIONS

These results suggest that SGP-2 can act as an extracellular mediator of anti-TNF-induced cytotoxicity.

Intraventricular perineurioma: case report

OBJECTIVE AND IMPORTANCE

Perineurioma, a rare benign nerve sheath neoplasm occurring in either an intraneural or soft tissue form, has never been reported to arise in the central nervous system.

CLINICAL PRESENTATION

We describe the clinical, radiological, and pathological features of a perineurioma arising in the choroid plexus of the third ventricle in a 65-year-old woman and causing obstructive hydrocephalus.

INTERVENTION

The lesion, apparently unassociated with a nerve, was gross totally resected by frontal craniotomy using a left-sided transcallosal approach. Short-term follow-up showed no evidence of recurrence.

CONCLUSION

Perineurioma of the variety found in soft tissue may occur in the central nervous system, wherein it shows the typical light microscopic, immunohistochemical (epithelial membrane antigen- and Collagen IV-positive, S-100 protein-negative), and ultrastructural (pinocytotic vesicles, discontinuous basement membrane) features.