Niacin as a component of combination therapy for dyslipidemia

Dyslipidemia is one of the most important modifiable risk factors for coronary disease. Despite the availability of highly effective lipid-modifying agents, many patients still do not reach lipid targets established by national guidelines. Niacin has been known to be an effective treatment of dyslipidemia for almost half a century. Niacin substantially increases high-density lipoprotein cholesterol (HDL-C) levels while lowering levels of low-density lipoprotein cholesterol (LDL-C), triglycerides, and lipoprotein(a). In addition, niacin converts small LDL particles into more buoyant, less atherogenic LDL particles. Combined with other agents, niacin offers an important treatment option for patients with dyslipidemia. In particular, niacin complements LDL-C-lowering drugs; it is the most effective agent available for increasing HDL-C levels while lowering levels of LDL-C and triglycerides and improving other lipid risk factors such as lipoprotein(a). Combining niacin with statins or bile acid sequestrant therapy is safe and effective for improving lipid levels and decreasing coronary risk. Differences in niacin formulations dictate tolerability profiles and should be considered when selecting niacin as part of lipid therapy. Furthermore, adverse effects on glucose and insulin sensitivity should be considered when selecting candidates for niacin therapy. Adding niacin to lipid-lowering regimens is a valuable option for physicians treating patients with dyslipidemia and should be considered in appropriate patients.

Raising an isolated low HDL-C level: why, how, and when?

Treating patients with isolated low high-density lipoprotein cholesterol (HDL-C) remains daunting. The decision to treat depends on the individual patient's overall risk for coronary heart disease (CHD). Strategies for raising HDL-C levels can include various lifestyle and drug therapies, which should be tailored to individual patients. While no current therapy is optimal, many can yield modest increases that translate into reduced risk for CHD events.

Long-term user perceptions of an implanted neuroprosthesis for exercise, standing, and transfers after spinal cord injury

This study was completed to understand the usage patterns, system performance, degree of satisfaction, complications, and health benefits as perceived by recipients of a surgically implanted neuroprosthesis for exercise, standing, and transfers in individuals with low-cervical or thoracic spinal cord injury (SCI). A standardized telephone survey was administered to 11 recipients of the Case Western Reserve University/Veterans Affairs (CWRU/VA) implanted standing neuroprosthesis with more than 12 months of experience with the functional electrical stimulation (FES) system. Nine implant recipients were using the neuroprosthesis regularly for standing and/or exercising at the time of the survey. All 11 implant recipients noted improved health and a reduced incidence of pressure sores, leg spasms, and urinary tract infections (UTIs). No incidents of deep-vein thrombosis, infection, cellulitis, or electrical burns because of the neuroprosthesis were noted. System recipients uniformly felt that the neuroprosthesis resulted in better overall health and general well-being. Subjects were moderately to very satisfied with the performance of the neuroprosthesis and unanimously expressed a willingness to repeat the surgery and rehabilitation to obtain the same clinical outcome. All implant recipients reported the system to be safe, reliable, and easy to use. The implanted standing neuroprosthesis appears to be a clinically acceptable and effective means of providing the ability to exercise, stand, and transfer to selected individuals with paraplegia or low tetraplegia.

Intraocular concentration and pharmacokinetics of triamcinolone acetonide after a single intravitreal injection

PURPOSE

To describe the pharmacokinetics occurring after the direct injection of triamcinolone acetonide into the vitreous humor of humans.

DESIGN

Interventional case series.

PARTICIPANTS

Five patients who received a single 4-mg intravitreal injection of triamcinolone acetonide.

METHODS

An aqueous humor sample was obtained from 5 eyes via an anterior chamber paracentesis at days 1, 3, 10, 17, and 31 after injection. At each visit, visual acuity and intraocular pressure were measured and indirect ophthalmoscopy was performed. A fluorescein angiogram was carried out at day 10. Concentrations were determined using high performance liquid chromatography; pharmacokinetic analysis was carried out using PK Analyst, an iterative, nonlinear, weighted, least-squares regression program.

MAIN OUTCOME MEASURES

Intraocular concentrations of triamcinolone were measured and population pharmacokinetic parameters were calculated.

RESULTS

Pharmacokinetic data followed a two-compartment model. Peak aqueous humor concentrations ranged from 2151 to 7202 ng/ml, half-lives from 76 to 635 hours, and the integral of the area under the concentration-time curve (AUC(0-t)) from 231 to 1911 ng/h per milliliter. After a single intravitreal injection of triamcinolone, the mean elimination half-life was 18.6 days in nonvitrectomized patients. The half-life in a patient who had undergone a vitrectomy was shorter at 3.2 days.

CONCLUSIONS

There was considerable intrasubject variation among peak concentration, AUC(0-t) values, and elimination half-lives. After intravitreal injection, measurable concentrations of triamcinolone would be expected to last for approximately 3 months (93 +/- 28 days) in the absence of a vitrectomy. Because triamcinolone pharmacokinetics were characterized only in elderly patients with macular edema, the results cannot be extrapolated to other patient populations.

HIV-1 vaccine development: constrained peptide immunogens show improved binding to the anti-HIV-1 gp41 MAb

The human immunodeficiency virus type I (HIV-1) transmembrane glycoprotein gp41 mediates viral entry through fusion of the target cellular and viral membranes. A segment of gp41 containing the sequence Glu-Leu-Asp-Lys-Trp-Ala has previously been identified as the epitope of the HIV-1 neutralizing human monoclonal antibody 2F5 (MAb 2F5). The 2F5 epitope is highly conserved among HIV-1 envelope glycoproteins. Antibodies directed at the 2F5 epitope have neutralizing effects on a broad range of laboratory-adapted HIV-1 variants and primary isolates. Recently, a crystal structure of the epitope bound to the Fab fragment of MAb 2F5 has shown that the 2F5 peptide adopts a beta-turn conformation [Pai, E. F., Klein, M. H., Chong, P., and Pedyczak, A. (2000) World Intellectual Property Organization Patent WO-00/61618]. We have designed cyclic peptides to adopt beta-turn conformations by the incorporation of a side-chain to side-chain lactam bridge between the i and i + 4 residues containing the Asp-Lys-Trp segment. Synthesis of extended, nonconstrained peptides encompassing the 2F5 epitope revealed that the 13 amino acid sequence, Glu-Leu-Leu-Glu-Leu-Asp-Lys-Trp-Ala-Ser-Leu-Trp-Asn, maximized MAb 2F5 binding. Constrained analogues of this sequence were explored to optimize 2F5 binding affinity. The solution conformations of the constrained peptides have been characterized by NMR spectroscopy and molecular modeling techniques. The results presented here demonstrate that both inclusion of the lactam constraint and extension of the 2F5 segment are necessary to elicit optimal antibody binding activity. The ability of these peptide immunogens to stimulate a high titer, peptide-specific immune response incapable of viral neutralization is discussed in regard to developing an HIV-1 vaccine designed to elicit a 2F5-like immune response.

1,3,4-Trisubstituted pyrrolidine CCR5 receptor antagonists. Part 3: polar functionality and its effect on anti-HIV-1 activity

Incorporation of acidic functional groups into a lead CCR5 antagonist identified from a targeted combinatorial library resulted in compounds with enhanced anti-HIV-1 activity and attenuated L-type calcium channel affinity.

A chloroplast transgenic approach to hyper-express and purify Human Serum Albumin, a protein highly susceptible to proteolytic degradation

Human Serum Albumin (HSA) accounts for 60% of the total protein in blood serum and it is the most widely used intravenous protein in a number of human therapies. HSA, however, is currently extracted only from blood because of a lack of commercially feasible recombinant expression systems. HSA is highly susceptible to proteolytic degradation in recombinant systems and is expensive to purify. Expression of HSA in transgenic chloroplasts using Shine-Dalgarno sequence (SD), which usually facilitates hyper-expression of transgenes, resulted only in 0.02% HSA in total protein (tp). Modification of HSA regulatory sequences using chloroplast untranslated regions (UTRs) resulted in hyper-expression of HSA (up to 11.1% tp), compensating for excessive proteolytic degradation. This is the highest expression of a pharmaceutical protein in transgenic plants and 500-fold greater than previous reports on HSA expression in transgenic leaves. Electron micrographs of immunogold labelled transgenic chloroplasts revealed HSA inclusion bodies, which provided a simple method for purification from other cellular proteins. HSA inclusion bodies could be readily solubilized to obtain a monomeric form using appropriate reagents. The regulatory elements used in this study should serve as a model system for enhancing expression of foreign proteins that are highly susceptible to proteolytic degradation and provide advantages in purification, when inclusion bodies are formed.

1,3,4 Trisubstituted pyrrolidine CCR5 receptor antagonists bearing 4-aminoheterocycle substituted piperidine side chains

A new class of 4-(aminoheterocycle)piperidine derived 1,3,4 trisubstituted pyrrolidine CCR5 antagonists is reported. Compound 4a is shown to have good binding affinity (1.8 nM) and antiviral activity in PBMC's (IC(95)=50 nM). Compound 4a also has improved PK properties relative to 1.

Effect of desirable fasting triglycerides on the postprandial response to dietary fat

BACKGROUND

The National Cholesterol Education Program (NCEP) recently revised the "desirable" fasting triglyceride (TG) to < 150 mg/dL, and levels exceeding 200 mg/dL are defined as "high."

METHODS

To evaluate the postprandial response to dietary fat, 50 studies were conducted in nonobese, normocholesterolemic subjects. Following an overnight fast, subjects consumed an oral fat load (70 g/m2), and postprandial triglyceride (ppTG) measurements were assessed at 2, 4, 6, and 8 hours. Subjects were divided by fasting TG cutpoints of 100 and 150 mg/dL.

RESULTS

The prevalence of ppTG samples exceeding 200 mg/dL was significantly lower with fasting TG < 100 mg/dL (n = 116) compared with TG 100 to 150 mg/dL (n = 56) (8% versus 25%; p = .004, chi-square analysis). In addition, fasting TG < 100 mg/dL (n = 29) was associated with a reduced mean 4-hour peak ppTG level compared with fasting TG > 100 mg/dL (n = 21) (125 mg/dL versus 249.8 mg/dL; p < .0001). Multiple linear regression analysis identified fasting TG as the most important determinant of the postprandial response after adjustment for other covariates (p = .0005).

CONCLUSIONS

Because ppTG-rich lipoproteins contribute to coronary heart disease risk, fasting TG < 100 mg/dL may be a more desirable cutpoint than fasting TG < 150 mg/dL in coronary heart disease risk factor assessment.

1,3,4-Trisubstituted pyrrolidine CCR5 receptor antagonists: modifications of the arylpropylpiperidine side chains

The 4-(3-phenylprop-1-yl)piperidine moiety of the 1,3,4-trisubstituted pyrrolidine CCR5 antagonist 1 was modified with electron deficient aromatics as well as replacement of the benzylic methylene with sulfones, gem-difluoromethylenes and alcohols in an effort to balance the antiviral potency with reasonable pharmacokinetics.

Oncology health care professionals' attitudes to cancer: a professional concern

BACKGROUND

Despite the known benefits of screening, early detection and advances in treatment modalities, negative attitudes to cancer persist among health care professionals, and cancer remains the most feared disease in modern society. Attitudes to cancer may create a barrier to communication between patients and health care professionals, hinder early detection, treatment and rehabilitation, and may influence decision making about referral to specialist services and the selection of appropriate treatments.

DESIGN

A descriptive survey was conducted, within a Regional Cancer Centre, to evaluate oncology health care professionals' attitudes towards cancer. Attitudes were measured using the Burns' Cancer Belief Scales.

RESULTS

Regardless of gender, profession and clinical experience, all health care professionals displayed persistently negative attitudes towards cancer. No statistically significant difference was detected between gender, profession, clinical experience or specialist education, and although small in number, no major differences were found between group means.

CONCLUSIONS

Oncology health care professionals hold negative attitudes towards cancer and changing these attitudes presents a significant challenge. Educational programmes and supportive strategies may alleviate fears and promote a more positive image of cancer. However, such strategies must be based on an understanding of current attitudes towards this phenomenon.

Dirigo Health--a universal health care coverage plan in Maine: implications for Massachusetts

On June 18th, Maine governor John Baldacci signed into law a comprehensive health care initiative know as Dirigo Health. Dirigo is Latin for "I lead", the state motto. Dirigo is often referred to as Maine's new universal coverage law. The law seeks to achieve universal access to coverage by integrating access, cost, and quality initiatives. While Dirigo responds to and takes advantage of particular circumstances in Maine, it has naturally drawn a great deal of interest from other states seeking to deal with similar problems. This issue brief provides an overview of Dirigo Health and outlines areas that might inform the health policy debate in Massachusetts (and perhaps other states as well).

Effects of superimposed electrical stimulation on perceived discomfort and torque increment size and variability

Superimposed electrical stimulation techniques can be used to detect central activation failure (CAF), that is, incomplete central nervous system recruitment or suboptimal activation of motor units. The purpose of this study was to evaluate the effects of two stimulation parameters on perceived discomfort and torque increment size and variability. Discomfort was evaluated using a visual analog scale (0-100 mm) for pain. The rectus femoris muscle of the dominant leg of 24 young healthy men was stimulated during submaximal (80% maximal) voluntary contractions. The size and variability of torque increments and perceived discomfort were assessed following stimulation with: (1) pulse trains (100 HZ, 150 V, 0.2-ms pulse duration) of different lengths (50 ms and 100 ms); and (2) pulse trains (100 HZ, 100 ms, 150 V) with different pulse durations (0.2 ms and 0.1 ms). Pulse trains of 100 ms generated larger torque increments and produced less variability, but caused more discomfort than pulse trains of 50 ms. Average discomfort ratings for pulse trains of 100 ms were 43.1 mm, and of 50 ms were 53.2 mm. There was no difference in torque increment size or in variability between pulse trains with pulse durations of 0.1 ms and 0.2 ms, whereas discomfort was less for the shorter pulse durations; average discomfort ratings were 53.1 mm and 58.1 mm for pulse durations of 0.1 ms and 0.2 ms, respectively. Thus, the appropriate selection of stimulation parameters can reduce discomfort but maintain the ability to detect CAF.

Observations on intraoperative somatosensory evoked potential (SEP) monitoring in the semi-sitting position

BACKGROUND

Former case reports suggest that monitoring of median nerve somatosensory evoked potentials (M-SEP) is unreliable in patients operated in the semi-sitting position due to the occurrence of evoked potential changes unrelated to neurological damage. This study was designed to analyze these changes in greater detail and confirm that these changes are not caused by neurological damage.

METHODS

M-SEP monitoring findings of 50 patients with surgery in the semi-sitting position were analyzed and compared with a group of 50 patients who underwent surgery in the supine position. M-SEP amplitudes and latencies at distinct steps of the monitoring procedure were used for further analysis. In 10 of the 50 semi-sitting patients, M-SEP were recorded additionally after surgery with the anesthetized patient in the supine position.

RESULTS

Significant M-SEP changes occurred in the semi-sitting patients only. An amplitude loss of greater than 50% on at least one side was observed in 24 patients. The magnitude and the time course of the amplitude loss was considerably variable. A complete loss of the evoked potential was not observed in any case. In all 10 patients, M-SEP recovered completely when recorded in the supine position.

CONCLUSIONS

In about half of the patients with M-SEP monitoring in the semi-sitting position, a significant amplitude loss occurs which is unrelated to neurological damage and presumably caused by subdural gas collections. There is no characteristic pattern of M-SEP changes which enables a differentiation of these 'artificial' alterations from true events. The only appropriate criterion to indicate an impending neurological damage in these patients seems to be a complete loss of the M-SEP potential.

Correlates of pre-treatment drop-out among persons with marijuana dependence

AIMS

Our objective was to identify client characteristics and other factors associated with pre-treatment drop-out by people with marijuana dependence.

DESIGN AND PARTICIPANTS

Data from the Marijuana Treatment Project's screening assessment were used to examine correlates of pre-treatment drop-out. Information from all eligible study participants (n = 813) (i.e. those who were interested in receiving treatment for their marijuana dependence and were determined to be eligible for the randomized treatment efficacy trial) was used to examine differences between the 450 participants who initiated treatment (by enrolling in the trial) and the 363 individuals who declined enrollment.

SETTING

The study was conducted at three community-based outpatient treatment facilities in Farmington, CT, Seattle, WA and Miami, FL.

MEASUREMENTS

The information gathered in the screening interview included demographic characteristics, residential stability variables, employment and education history and referral source. Substance use variables included the number of days and the number of times per day marijuana was used, self-perceived dependence on marijuana, alcohol or other drugs, other drug use history and current treatment (i.e. substance abuse, medical, psychiatric) situation.

FINDINGS

Stepwise logistic regression was conducted to confirm variables associated with treatment initiation in bivariate analyses. Pre-treatment drop-out was associated with being younger, unmarried, unemployed, less educated and Asian American or Native American. It was also associated with self-perceived dependence on marijuana and use of other drugs.

CONCLUSIONS

By recognizing demographic and substance use factors that may serve as barriers for individuals accessing treatment for marijuana dependence, clinicians may target clients with these characteristics proactively to encourage treatment initiation and subsequent attendance.

Association of rates of household handgun ownership, lifetime major depression, and serious suicidal thoughts with rates of suicide across US census regions

OBJECTIVE

Cross sectional studies in the United States often find a significant positive association between levels of household firearm ownership and suicide rates. This study investigates whether the association can be explained by differences in levels of mental health.

METHODS

The relationship between household handgun ownership and overall suicide rates across United States regions after accounting for two mental health variables-lifetime prevalence of major depression and serious suicidal thoughts-were examined. Analyses also add another control variable (urbanization, education, unemployment, or alcohol consumption). Data on mental health variables come from the National Comorbidity Study, conducted in the early 1990s. Data on household handgun ownership come from the General Social Surveys.

RESULTS

Across the nine regions for the early 1990s (n = 9), household handgun ownership rates are positively correlated with the suicide rate (r = 0.59) and are not correlated with either the lifetime prevalence of major depression or suicidal thoughts. After controlling for major depression and suicidal thoughts (and any of the four additional control variables), handgun ownership rates remain significantly associated with the overall suicide rate.

CONCLUSIONS

In United States regions with higher levels of household handgun ownership, there are higher suicide rates. This relationship cannot be explained by differences in the prevalence of two mental health indicators-lifetime rates of either major depression or suicidal thoughts.

The Marijuana Treatment Project: rationale, design and participant characteristics

AIMS

Recent findings regarding the prevalence of marijuana dependence and associated consequences indicate the need for empirically validated treatments for this population. The Marijuana Treatment Project (MTP) was a multi-site study of two treatments for adults with marijuana dependence.

DESIGN

Participants (N= 450) were randomly assigned to one of three conditions at each of three sites: 1) a 9-session cognitive behavioral treatment (CBT) with motivational enhancement therapy (MET) and case management (CM) components; 2) a 2-session MET intervention; or 3) a delayed treatment control (DTC).

SETTING

The study was conducted in outpatient drug treatment clinics in three U.S. cities.

PARTICIPANTS

Participants were individuals aged 18 or over who met diagnostic criteria for cannabis dependence and who voluntarily presented for treatment.

MEASUREMENT

Study variables included DSM-IV dependence criteria, timeline follow-back assessment of drug use, Addiction Severity Index composite scores, and problems related to marijuana use.

FINDINGS

Participants were daily users, who smoked marijuana multiple times per day, and had been doing so for more than 15 years. They reported multiple dependence symptoms and negative consequences related to marijuana use. Approximately 32% of the sample was female, and 30% of the sample was either Hispanic (17%), African American (12%), or of mixed racial backgrounds (1%).

CONCLUSIONS

The multi-site nature of the MTP allowed for the recruitment of a more ethnically and gender diverse sample than had been studied previously but there were few differences in the clinical characteristics of participants at the geographically and sociodemographically diverse study sites.

The effect of implant constraint on results of conversion of unicompartmental knee arthroplasty to total knee arthroplasty

A series of unicompartmental knee arthroplasty (UKA) revision to total knee arthroplasty (TKA) was compared to a group of primary TKAs performed at the same institution. The UKA revision group had a higher incidence of local wound complications and inferior clinical results as measured by Knee Society scores. When the revisions were stratified by the degree of interface constraint, knees revised with posterior cruciate ligament (PCL) substituting designs had superior knee scores that were comparable to the primary group. The use of a PCL-substituting knee design is recommended when converting a UKA to TKA.

Tailoring cannabis dependence treatment for a diverse population

Accumulating evidence suggests that psychosocial treatment for cannabis dependence is effective. Earlier investigations were well designed and sought to evaluate efficacy of manual-guided therapies with particular attention to protecting the independent variable. The Marijuana Treatment Project (MTP) represents an effort to build upon previous knowledge about cannabis dependence treatment through an evaluation of an integrative therapy, which was meant to allow for greater therapist latitude in its delivery, and to be more responsive to a potentially more diverse population of clients. The treatment intervention developed for delivery in the Marijuana Treatment Project (MTP) reflects an effort to find a true compromise between the needs of the scientific community to have clearly specified and measurable treatments, and the realities of the treatment community, which demand flexibility, appreciation of the multi-determined nature of most problems, and individualized approaches. This paper will describe the clinical interventions used with the MTP participants, the theoretical rationale guiding their design and practical aspects related to implementation and treatment response.

Passive resistive torque of the plantar flexors following eccentric loading as assessed by isokinetic dynamometry

Isokinetic dynamometers may provide a useful means of measuring muscle stiffness resulting from eccentric exercise because they can measure torque from computer-controlled passive movements of joints (passive resistive torque; PRT). In this study, a Biodex measured increased ankle PRT (52%; p <.001) following heel drop exercise in nine young women. Therefore, isokinetic dynamometers can provide a means to study group changes as a result of eccentric exercise. Future studies are required to determine the reliability of this protocol before it can be advocated in studying single cases.

Sex partner support, drug use and sex risk among HIV-negative non-injecting heroin users

HIV prevention efforts among drug users have incorporated social support to reinforce risk reduction. We examine the extent to which sex partner characteristics, including partner support, influence HIV sex risk practices among a little studied population of non-injecting heroin users, 257 of whom were recruited in New York City between 1996 and 2001. The sample was racially/ethnically diverse (26% African American, 43% Latino, 31% white or other ethnicity) and 65% male. Three-quarters reported having unprotected intercourse within 30 days; 27% had sex with partners at known risk of being HIV infected. There were no gender differences in terms of sex or drug use practices; however, gender differences in sex partner characteristics were apparent. Men were significantly less likely than women to have partners who used drugs (OR = 0.5, 95% CI = 0.3, 0.9), receive support from their partners (OR = 0.5, 95% CI = 0.3, 0.8), use heroin with their partners (OR = 0.5, 95% CI = 0.3, 0.8) and have partners at known risk of being HIV infected (OR = 0.4, 95% CI = 0.2, 0.7). For men, increased sex risk was independently associated with sex partner support, and for women, increased sex risk was independently associated with having used heroin with sex partners. Social support may have detrimental, as well as beneficial, consequences on HIV risk.