Utility of screening for silent myocardial ischaemia in diabetes with an annual electrocardiogram

BACKGROUND AND METHODS

Asymptomatic coronary artery disease (CAD) is common in people with diabetes mellitus, but there is a lack of consensus regarding appropriate screening for the condition. We performed a 12-lead electrocardiogram (ECG) on 312 consecutive participants with diabetes mellitus attending for routine annual outpatient review in order to determine the effectiveness of a yearly ECG in screening people with diabetes for asymptomatic CAD.

RESULTS

Three of 312 participants (0.96%, 95% CI 0.2%-2.78%) had a newly identified ECG abnormality. One person had newly discovered atrial fibrillation. Two people had abnormalities which prompted further investigation for asymptomatic CAD. One of these participants underwent percutaneous coronary intervention. Seventeen further participants had abnormalities on ECG which had been previously documented, the majority having been present since their diagnosis of diabetes.

CONCLUSION

A low positive yield of routine annual ECG in our study does not support its use as a screening tool for asymptomatic CAD in diabetes. Our findings support advice to perform an ECG at diagnosis of diabetes and to repeat only if a person develops relevant symptoms.

Neoadjuvant Radiotherapy Dose Escalation in Locally Advanced Rectal Cancer: a Systematic Review and Meta-analysis of Modern Treatment Approaches and Outcomes

AIMS

Improving pathological complete response (pCR) rates after neoadjuvant chemoradiotherapy for locally advanced rectal cancer may facilitate surgery-sparing treatment paradigms. Radiotherapy boost has been linked to higher rates of pCR; however, outcomes in moderately escalated inverse-planning studies have not been systematically evaluated. We therefore carried out a systematic review and meta-analysis of radiation dose-escalation studies in the context of neoadjuvant therapy for locally advanced rectal cancer.

MATERIALS AND METHODS

A systematic search of Pubmed, EMBASE and Cochrane databases for synonyms of 'rectal cancer', 'radiotherapy' and 'boost' was carried out. Studies were screened for radiotherapy prescription >54 Gy. Prespecified quality assessment was carried out for meta-analysis inclusion suitability. Pooled estimates of pCR, acute toxicity (grade ≥3) and R0 resection rates were determined with random-effects restricted maximum-likelihood estimation. Heterogeneity was assessed with Higgins I² and Cochran Q statistic. Subset analysis examined outcomes in modern inverse-planning studies. Meta-regression with permutation correction was carried out for each outcome against radiation dose, radiotherapy technique, boost technique, chemotherapy intensification and other patient- and treatment-related cofactors.

RESULTS

Forty-nine primary and three follow-up publications were included in the systematic review. Pooled estimates of pCR, toxicity and R0 resection across 37 eligible publications (n = 1817 patients) were 24.1% (95% confidence interval 21.2-27.4%), 11.2% (95% confidence interval 7.2-17.0%) and 90.7% (95% confidence interval 87.9-93.8%). Within inverse-planning studies (17 publications, n = 959 patients), these rates were 25.7% (95% confidence interval 21.0-31.1%), 9.8% (95% confidence interval 4.6-19.7%) and 95.3% (95% confidence interval 91.6-97.4%). Regression analysis did not identify any significant predictor of pCR (P > 0.05).

CONCLUSIONS

Radiotherapy dose escalation above 54 Gy is associated with high rates of pCR and does not seem to increase the risk of acute grade ≥3 toxicity events. pCR rates approaching 25% may be achievable utilising moderate escalation (54-60 Gy) with modern inverse-planning techniques; however, a clear dose-response relationship was not identified in regression analysis and additional evidence is awaited given the prevalence of heterogenous single-arm studies to date.

A Review of Modern Radiation Therapy Dose Escalation in Locally Advanced Head and Neck Cancer

The management of head and neck cancer is complex and often involves multimodality treatment. Certain groups of patients, such as those with inoperable or advanced disease, are at higher risk of treatment failure and may therefore benefit from radiation therapy dose escalation. This can be difficult to achieve without increasing toxicity. However, the combination of modern treatment techniques and increased research into the use of functional imaging modalities that assist with target delineation allows researchers to push this boundary further. This review aims to summarise modern dose escalation trials to identify the impact on disease outcomes and explore the growing role of functional imaging modalities. Studies experimenting with dose escalation above standard fractionated regimens as outlined in National Comprehensive Cancer Network guidelines using photon therapy were chosen for review. Seventeen papers were considered suitable for inclusion in the review. Eight studies investigated nasopharyngeal cancer, with the remainder treating a range of subsites. Six studies utilised functional imaging modalities for target delineation. Doses as high as 85.9 Gy in 2.6 Gy fractions (EQD2 90.2 Gy₁₀) were reportedly delivered with the aid of functional imaging modalities. Dose escalation in nasopharyngeal cancer resulted in 3-year locoregional control rates of 86.6-100% and overall survival of 82-95.2%. For other mucosal primary tumour sites, 3-year locoregional control reached 68.2-85.9% and 48.4-54% for overall survival. There were no clear trends in acute or late toxicity across studies, regardless of dose or addition of chemotherapy. However, small cohort sizes and short follow-up times may have resulted in under-reporting. This review highlights the future possibilities of radiation therapy dose escalation in head and neck cancer and the potential for improved target delineation with careful patient selection and the assistance of functional imaging modalities.

Perspective: partnering for medical education in Sub-Saharan Africa: seeking the evidence for effective collaborations

One of the major needs for medical schools and health systems in less affluent countries is system strengthening through the training and development of faculty, doctors, nurses, and other skilled health care workers. Partnering with medical schools in more affluent countries such as the United States is one potential approach for medical schools in underresourced areas, such as Sub-Saharan Africa. Most commonly, these partnerships have focused on research agendas or limited educational exchanges. In this perspective, the authors present an approach to strengthening collaborative relationships between three medical schools in the United States and four in Sub-Saharan Africa. The approach is explicitly focused on achieving partnerships that enable institutions to improve care. It developed from an initiative to fund partnerships or "collaboratives" that address 10 key learning questions determined to be central to focusing efforts on strengthening education systems and, in turn, improving health in Sub-Saharan Africa. The leaders of the schools involved in these partnerships met multiple times across three years to discuss how their collaboratives could address the ten learning questions including what is the best approach and what are the key ingredients for creating effective, multidimensional collaborations between academic institutions in the North and institutions in Sub-Saharan Africa. Collaboratively, they defined a framework of evidence that can be used for evaluating their current initiatives and, potentially, for structuring future partnerships.

Simple model of the transduction of cell-penetrating peptides

Cell-penetrating peptides (CPPs) such as HIV's trans-activating transcriptional activator (TAT) and polyarginine rapidly pass through the plasma membranes of mammalian cells by an unknown mechanism called transduction. They may be medically useful when fused to well-chosen chains of fewer than about 35 amino acids. The author offers a simple model of transduction in which phosphatidylserines and CPPs effectively form two plates of a capacitor with a voltage sufficient to cause the formation of transient pores (electroporation). The model is consistent with experimental data on the transduction of oligoarginine into mouse C(2)C(12) myoblasts and makes three testable predictions. [Includes supplementary material].

Mass media interventions for smoking cessation in adults

BACKGROUND

Mass media tobacco control campaigns can reach large numbers of people. Much of the literature is focused on the effects of tobacco control advertising on young people, but there are also a number of evaluations of campaigns targeting adult smokers, which show mixed results. Campaigns may be local, regional or national, and may be combined with other components of a comprehensive tobacco control policy.

OBJECTIVES

To assess the effectiveness of mass media interventions in reducing smoking among adults.

SEARCH STRATEGY

The Cochrane Tobacco Addiction Group search strategy was combined with additional searches for any studies that referred to tobacco/smoking cessation, mass media and adults. We also searched the Cochrane Register of Controlled Trials (CENTRAL) and a number of electronic databases. The last search was carried out in March 2007.

SELECTION CRITERIA

Controlled trials allocating communities, regions or states to intervention or control conditions; interrupted time series.Adults, 25 years or older, who regularly smoke cigarettes. Studies which cover all adults as defined in studies were included. Mass media are defined here as channels of communication such as television, radio, newspapers, billboards, posters, leaflets or booklets intended to reach large numbers of people, and which are not dependent on person-to-person contact. The purpose of the mass media campaign must be primarily to encourage smokers to quit. They could be carried out alone or in conjunction with tobacco control programmes.The primary outcome was change in smoking behaviour. This could be reported as changes in prevalence, changes in cigarette consumption, quit rates, odds of being a smoker.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed all studies for inclusion criteria and for study quality. One author (MB) extracted data, and a second author (LS) checked them.Results were not pooled due to heterogeneity of included studies and are presented narratively and in table form.

MAIN RESULTS

Eleven campaigns met the inclusion criteria for this review. Studies differed in design, settings, duration, content and intensity of intervention, length of follow up, methods of evaluation and also in definitions and measures of smoking behaviour used. Among nine campaigns reporting smoking prevalence, significant decreases were observed in the California and Massachusetts statewide tobacco control campaigns compared with the rest of the USA. Some positive effects on prevalence in the whole population or in the subgroups were observed in three of the remaining seven studies. Three large-scale campaigns of the seven presenting results for tobacco consumption found statistically significant decreases. Among the seven studies presenting abstinence or quit rates, four showed some positive effect, although in one of them the effect was measured for quitting and cutting down combined. Among the three that did not show significant decreases, one demonstrated a significant intervention effect on smokers and ex-smokers combined.

AUTHORS' CONCLUSIONS

There is evidence that comprehensive tobacco control programmes which include mass media campaigns can be effective in changing smoking behaviour in adults, but the evidence comes from a heterogeneous group of studies of variable methodological quality. One state-wide tobacco control programme (Massachusetts) showed positive results up to eight years after the campaign, while another (California) showed positive results only during the period of adequate funding and implementation. Six of nine studies carried out in communities or regions showed some positive effects on smoking behaviour and at least one significant change in smoking prevalence (Sydney). The intensity and duration of mass media campaigns may influence effectiveness, but length of follow up and concurrent secular trends and events can make this difficult to quantify. No consistent relationship was observed between campaign effectiveness and age, education, ethnicity or gender.

Cannabinoid type 1 receptor antagonists (rimonabant) for smoking cessation

BACKGROUND

Rimonabant is a selective type 1 cannabinoid (CB1) receptor antagonist. It may assist with smoking cessation by restoring the balance of the endocannabinoid system, which can be disrupted by prolonged use of nicotine. Rimonabant also seeks to address many smokers' reluctance to persist with a quit attempt because of concerns about weight gain.

OBJECTIVES

To determine whether selective CB1 receptor antagonists increase the numbers of people stopping smoking. To assess their effects on weight change in successful quitters and in those who try to quit but fail.

SEARCH STRATEGY

We searched the Cochrane Tobacco Addiction Review Group specialized register for trials, using the terms 'rimonabant' and 'smoking' in the title or abstract, or as keywords. We also searched MEDLINE, EMBASE, CINAHL and PsycINFO, using major MESH terms. We acquired electronic or paper copies of posters of preliminary trial results presented at the American Thoracic Society Meeting in 2005, and at the Society for Research on Nicotine and Tobacco European Meeting 2006. We also attempted to contact the authors of ongoing studies of rimonabant, and Sanofi Aventis (manufacturers of rimonabant).

SELECTION CRITERIA

Types of studies: Randomized controlled trials.

TYPES OF PARTICIPANTS

Adult smokers. Types of interventions: Selective CB1 receptor antagonists, such as rimonabant. Types of outcome measures: The primary outcome is smoking status at a minimum of six months after the start of treatment. We preferred sustained cessation rates to point prevalence, and biochemically verified cessation to self-reported quitting. We regarded smokers who drop out or are lost to follow up as continuing smokers. We have noted any adverse effects of treatment.A secondary outcome is weight change associated with the cessation attempt.

DATA COLLECTION AND ANALYSIS

Two authors checked the abstracts for relevance, and attempted to acquire full trial reports. One author extracted the data, and a second author checked them.

MAIN RESULTS

We found three trials which met our inclusion criteria, covering 1567 smokers (cessation: STRATUS-EU and STRATUS-US), and 1661 quitters (relapse prevention: STRATUS-WW). At one year, the pooled odds ratio (OR) for quitting with rimonabant 20 mg was 1.61 (95% confidence interval (CI) 1.12 to 2.30). No significant benefit was demonstrated for rimonabant at 5 mg dosage. Adverse events included nausea and upper respiratory tract infections. In the relapse prevention trial, smokers who had quit on the 20 mg regimen were 1(1/2) times more likely to remain abstinent on either active regimen than on placebo; the OR for the 20 mg maintenance group was 1.49 (95% CI 1.09 to 2.04, and for the 5 mg maintenance group 1.51 (95% CI 1.11 to 2.07). There appeared to be no significant benefit of maintenance treatment for the 5 mg quitters. Weight gain was reported to be significantly lower among the 20 mg quitters than in the 5 mg or placebo quitters. During treatment, overweight or obese smokers tended to lose weight, while normal weight smokers did not.

AUTHORS' CONCLUSIONS

From the preliminary trial reports available, rimonabant 20 mg may increase the odds of quitting approximately 1(1/2)-fold. Adverse events include nausea and upper respiratory tract infections; the risk of serious adverse events is reported to be low. However, there is current concern (August 2007) over rates of depression and suicidal thoughts in people taking rimonabant for weight control. The evidence for rimonabant in maintaining abstinence is inconclusive. Rimonabant 20 mg may moderate weight gain in the long term.

Cannabinoid type 1 receptor antagonists (rimonabant) for smoking cessation

BACKGROUND

Rimonabant is a selective type 1 cannabinoid (CB1) receptor antagonist. It may assist with smoking cessation by restoring the balance of the endocannabinoid system, which can be disrupted by prolonged use of nicotine. Rimonabant also seeks to address many smokers' reluctance to persist with a quit attempt because of concerns about weight gain.

OBJECTIVES

To determine whether selective CB1 receptor antagonists increase the numbers of people stopping smoking. To assess their effects on weight change in successful quitters and in those who try to quit but fail.

SEARCH STRATEGY

We searched the Cochrane Tobacco Addiction Review Group specialized register for trials, using the terms 'rimonabant' and 'smoking' in the title or abstract, or as keywords. We also searched MEDLINE, EMBASE, CINAHL and PsycINFO, using major MESH terms. We acquired electronic or paper copies of posters of preliminary trial results presented at the American Thoracic Society Meeting in 2005, and at the Society for Research on Nicotine and Tobacco European Meeting 2006. We also attempted to contact the authors of ongoing studies of rimonabant, and Sanofi Aventis (manufacturers of rimonabant).

SELECTION CRITERIA

Types of studies: Randomized controlled trials.

TYPES OF PARTICIPANTS

Adult smokers. Types of interventions: Selective CB1 receptor antagonists, such as rimonabant. Types of outcome measures: The primary outcome is smoking status at a minimum of six months after the start of treatment. We preferred sustained cessation rates to point prevalence, and biochemically verified cessation to self-reported quitting. We regarded smokers who drop out or are lost to follow up as continuing smokers. We have noted any adverse effects of treatment. A secondary outcome is weight change associated with the cessation attempt.

DATA COLLECTION AND ANALYSIS

Two authors checked the abstracts for relevance, and attempted to acquire full trial reports. One author extracted the data, and a second author checked them.

MAIN RESULTS

We found three trials which met our inclusion criteria, covering 1567 smokers (cessation: STRATUS-EU and STRATUS-US), and 1661 quitters (relapse prevention: STRATUS-WW). At one year, the pooled odds ratio (OR) for quitting with rimonabant 20 mg was 1.61 (95% confidence interval (CI) 1.12 to 2.30). No significant benefit was demonstrated for rimonabant at 5 mg dosage. Adverse events included nausea and upper respiratory tract infections. In the relapse prevention trial, smokers who had quit on the 20 mg regimen were 1(1/2) times more likely to remain abstinent on either active regimen than on placebo; the OR for the 20 mg maintenance group was 1.49 (95% CI 1.09 to 2.04, and for the 5 mg maintenance group 1.51 (95% CI 1.11 to 2.07). There appeared to be no significant benefit of maintenance treatment for the 5 mg quitters.Weight gain was reported to be significantly lower among the 20 mg quitters than in the 5 mg or placebo quitters. During treatment, overweight or obese smokers tended to lose weight, while normal weight smokers did not.

AUTHORS' CONCLUSIONS

From the preliminary trial reports available, rimonabant 20 mg may increase the odds of quitting approximately 1 and one-half-fold. Adverse events include nausea and upper respiratory tract infections; the risk of serious adverse events is reported to be low. The evidence for rimonabant in maintaining abstinence is inconclusive. Rimonabant 20 mg may moderate weight gain in the long term.

Nicotine receptor partial agonists for smoking cessation

BACKGROUND

Nicotine receptor partial agonists may help smokers to quit by a combination of maintaining moderate levels of dopamine to counteract withdrawal symptoms (acting as an agonist) and reducing smoking satisfaction (acting as an antagonist). Varenicline was developed as a nicotine receptor partial agonist from cytisine, a drug widely used in central and eastern Europe for smoking cessation. The first trial reports of varenicline were released in 2006, and further trials are underway.

OBJECTIVES

The primary objective of this review is to assess the efficacy and tolerability of nicotine receptor partial agonists, including varenicline and cytisine, for smoking cessation.

SEARCH STRATEGY

We searched the Cochrane Tobacco Addiction Group's specialised register for trials, using the terms ('varenicline' or 'cytisine' or 'Tabex' or 'nicotine receptor partial agonist') and 'smoking' in the title or abstract, or as keywords. We also searched MEDLINE, EMBASE, PsycINFO and CINAHL using MeSH terms and free text, and we contacted authors of trial reports for additional information where necessary. The last search was in October 2006.

SELECTION CRITERIA

We included randomized controlled trials which compared the treatment drug with placebo. We also included comparisons with bupropion where available. We excluded trials which did not report a minimum follow-up period of six months from start of treatment.

DATA COLLECTION AND ANALYSIS

We extracted data in duplicate on the type of participants, the dose and duration of treatment, the outcome measures, the randomization procedure, concealment of allocation, and completeness of follow up. The main outcome measured was abstinence from smoking after at least six months from the beginning of treatment. We used the most rigorous definition of abstinence, and preferred biochemically validated rates where they were reported. Where appropriate we performed meta-analysis using the Mantel-Haenszel fixed-effect model.

MAIN RESULTS

We found five trials of varenicline compared with placebo for smoking cessation; three of these also included a bupropion experimental arm. We also found one relapse prevention trial, comparing varenicline with placebo. The six trials covered 4924 participants, 2451 of whom used varenicline. We identified one trial of cytisine (Tabex) for inclusion. The pooled odds ratio (OR) for continuous abstinence at 12 months for varenicline versus placebo was 3.22 (95% confidence interval [CI] 2.43 to 4.27). The pooled OR for varenicline versus bupropion was 1.66 (95% CI 1.28 to 2.16). The main adverse effect of varenicline was nausea, which was mostly at mild to moderate levels and usually subsided over time. The two trials which tested the use of varenicline beyond the 12-week standard regimen found the drug to be well-tolerated and effective during long-term use. The one cytisine trial included in this review found that more participants taking cytisine stopped smoking compared with placebo at two-year follow up, with an OR of 1.77 (95% CI 1.30 to 2.40).

AUTHORS' CONCLUSIONS

Varenicline increased the odds of successful long-term smoking cessation approximately threefold compared with pharmacologically unassisted quit attempts. In trials reported so far, more participants quit successfully with varenicline than with bupropion. The effectiveness of varenicline as an aid to relapse prevention has not been clearly established. The main adverse effect of varenciline is nausea, but this is mostly at mild to moderate levels and tends to reduce with habituation. There is a need for independent trials of varenicline versus placebo, to test the early findings. There is also a need for direct comparisons with nicotine replacement therapy, and for further trials with bupropion, to establish the relative efficacy of the treatments.Cytisine may also increase the chances of quitting, but the evidence at present is inconclusive.

"Is this a dagger I see before me?"--an audit of stabbings and gunshot wounds in Limerick

BACKGROUND

According to a recent study in Cardiff, the incidence of stab wounds is 14 per 100,000 population per annum. No such figures are available for Ireland.

AIM

To evaluate the incidence, type of injury, medical consequences and outcome of patients with stab or gunshot wounds presenting to the Mid-Western Regional Hospital, Limerick, over a 12 month period.

METHOD

A retrospective case study of all stab and gunshot wounds presenting over a 12 month period.

RESULTS

Out of 62,000 new presentations to the Accident and Emergency (A&E) department, 101 (0.16%) were stabbings, giving an incidence of 33 per 100,000 population. Twenty-six patients required surgical intervention. There were three deaths. There were 10 gunshot wounds, of which 40% required surgical intervention, with no mortalities.

CONCLUSION

The incidence of stab wounds presenting to our institution is high. Although constituting a small percentage of presentations to the A&E department they result in considerable morbidity and surgical activity.

Comparison of the effectiveness of two pressure-relieving surfaces: low-air-loss versus static fluid

Limited research has been done to determine the effectiveness of the multitude of pressure reduction devices currently available for patient care. The purpose of this investigation was to examine the relative effectiveness of a dynamic low-air-loss (LAL) mattress and a static fluid mattress in reducing the risk of pressure ulcer development. The investigation consisted of two components: a comparative laboratory study and a retrospective clinical study. In the laboratory study, tissue interface pressures were measured on the two surfaces at three interface sites in a sample of six healthy adult volunteers. In the clinical study, a retrospective chart review was conducted to compare the actual incidence of pressure ulcer formation in a sample of 73 postoperative transplant patients who were placed on either the static fluid or LAL product. The instruments used were the Xsensor Pressure Mapping System (laboratory) and chart review tool (clinical). The main outcome measures included tissue interface pressures and incidence of pressure ulcer formation. The results were as follows: the laboratory study revealed significantly lower sacral pressures (t = -5.30, P = .003) on the low-air-loss mattress than on the static fluid mattress. Pressures did not differ significantly at the heel or trochanter sites. In the clinical study, the overall incidence of skin breakdown was 8.2%, with 5 occurrences (13.8%) in the LAL group and 1 occurrence (2.7%) in the static fluid group. However, this difference was not significant (Fisher's exact test = 0.107, P = .09). When considered jointly, the results of the two studies suggest that the static fluid and LAL products may be comparable in efficacy. Although the relatively small sample sizes used in the investigation limit generalizability, the results provide some initial direction for further clinical research in this area.

Transforming growth factor-beta levels in human allograft chronic fibrosis correlate with rate of decline in renal function

BACKGROUND

Long-term renal transplant function is limited primarily by a progressive scarring process loosely termed "chronic rejection, chronic allograft nephropathy, or allograft fibrosis." Although the etiology of transplant fibrosis is uncertain, several possible factors including chronic cyclosporin A (CsA) exposure may contribute to its pathogenesis. CsA stimulates renal fibrosis perhaps through the induction of the potent pro-sclerotic growth factor, transforming growth factor beta (TGFbeta). Previously, we demonstrated that, in human transplant biopsies, acute CsA toxicity but not acute tubular necrosis is associated with elevated levels of renal TGFbeta protein. We now examine whether long-term CsA treatment (>1 year) is associated with elevated levels of intra-allograft TGFbeta and whether heightened expression of TGFbeta is clinically significant.

METHODS

Using immunohistochemical techniques, we determined the relative level of expression of intrarenal TGFbeta protein in transplant biopsies. We studied biopsies obtained from 40 CsA-treated patients that were diagnosed as having chronic allograft fibrosis. Biopsies were scored as having minimal or high levels of TGFbeta.

RESULTS

Seventy-two percent of patients expressed high levels of intra-allograft TGFbeta. This group of patients lost renal function at an average rate of -19.5+/-17.3 ml/min/year. In contrast, patients with minimal or no TGFbeta expression experienced a decline of only -6.2+/-4.1 ml/min/year (P=0.01).

CONCLUSIONS

These results suggest that the majority of CsA-treated patients with biopsy proven chronic fibrosis have elevated levels of intra-graft TGFbeta that correlates with an increased rate of decline in renal function.

Differences between descriptive and multivariate estimates of the impact of Chevron Corporation's Health Quest Program on medical expenditures

This investigation focused on alternative methods for evaluating the impact of Chevron Corporation's Health Quest Fitness Center program on medical expenditures, comparing descriptive and multivariate research designs. Many uncontrolled studies of corporate health management programs base estimates of program effectiveness on descriptive analyses such as Student's tests. Unlike more sophisticated multivariate analyses, descriptive analyses often produce biased estimates of program cost savings. To test alternative research design methods, the investigators compared inpatient and pharmacy expenditures for program participants and non-participants over a 2.5-year period, using descriptive and multivariate regression analyses. Results showed that compared with non-participants, expenditures for participants were significantly lower for subjects who used a Health Quest fitness center at least twice weekly. Previous descriptive studies suggested a much broader impact. The results underscore the need to use multivariate analyses when evaluating the financial impact of corporate health management programs, especially when randomization cannot be used to assign participation status.

HIV antibody testing and posttest counseling in the United States: data from the 1989 National Health Interview Survey

To see how successful human immunodeficiency virus (HIV) counseling and testing efforts have been in testing the United States population, particularly among those at increased risk for HIV infection, we analyzed data from the 1989 National Health Interview Survey. Twenty percent of the NHIS sample (or, in terms of the general US population, an estimated 36 million persons) reported having been tested for HIV antibodies, mostly through blood donations. Although persons with increased risk of HIV infection had been tested and counseled at a much higher rate than the general population, the majority of this group had not yet been tested.

Differential effects of a murine and chimeric mouse/human anti-interleukin-2 receptor antibody on human T-cell proliferation

The preference for interleukin-2 receptor (IL-2R) expression on activated, compared with resting T lymphocytes makes the IL-2R a promising target for selective immunosuppressive therapy. To increase the potential therapeutic effectiveness of anti-IL-2R monoclonals, a chimeric mouse/human variant was constructed from Ig genes isolated from a murine anti-human IL-2R hybridoma cell line, designated AHT54. AHT54 binds to the same or spatially related epitope as IL-2 on the p55 protein that constitutes the low- and high-affinity forms of IL-2R. Although the murine and chimeric AHT54 antibodies inhibited cell-surface binding of IL-2 to the same extent, the chimeric antibodies containing a human IgG1 constant region had substantially more anti-proliferative activity than their murine IgG1 counterparts. Our results indicated that the human constant region of the chimeric antibodies interacted more efficiently than the murine constant region with effector components present in peripheral blood mononuclear cells (PBMC).

A chimeric mouse/human anti-IL-2 receptor antibody with enhanced biological activities

A chimeric mouse/human MAb against the human p55 IL-2R was constructed from Ig genes isolated from a mouse hybridoma cell line, designated AHT107. AHT107 binds to a different epitope on p55 than IL-2, and similar to observations made for other rodent anti-IL-2R antibodies that do not recognize the same or spatially related epitope as IL-2, murine AHT107 did not efficiently inhibit proliferation of T-lymphocytes in mitogen and MLR PBMC stimulation assays. In contrast, the chimeric AHT107 antibodies containing a human IgG-1 constant region had substantially more anti-proliferative activity than their murine IgG-I counterparts. Our results indicated that the human constant region of the chimeric antibodies interacted more efficiently than the murine constant region with effector components present in the PBMC cultures. This conclusion was supported by our observation that F(ab')2 generated from the chimeric antibodies did not efficiently inhibit proliferation in the PBMC assays, and the chimeric antibodies did not inhibit proliferation of an antigen specific, IL-2 dependent human T-cell clone stimulated in the absence of PBMC.

Gene-sized macronuclear DNA molecules are clustered in micronuclear chromosomes of the ciliate Oxytricha nova

Following the sexual phase of its life cycle, the hypotrichous ciliate Oxytricha nova transforms a copy of its chromosomal micronucleus into a macronucleus containing short, linear DNA molecules with an average size of 2.2 kilobase pairs. In addition, more than 90% of the DNA sequences in the micronuclear genome are eliminated during this process. We have examined the organization of macronuclear DNA molecules in the micronuclear chromosomes. Macronuclear DNA molecules were found to be clustered and separated by less than 550 base pairs in two cloned segments of micronuclear DNA. Recombinant clones of two macronuclear DNA molecules that are adjacent in the micronucleus were also isolated and examined by DNA sequencing. The two macronuclear DNA molecules were found to be separated by only 90 base pairs in the micronuclear genome.

Yellow fever immunity surveys in northern Uganda and Kenya and eastern Somalia, 1966-67

Recent epidemics of yellow fever in eastern Africa have stimulated serological surveys in the Karamoja district of Uganda, the northern frontier district of Kenya and the Giohar district of Somalia. All sera collected in the surveys were screened for group B arbovirus antibody using the HI test. Yellow fever immunity was confirmed by the mouse-protection test.No yellow fever immunity was found in sera collected from a residential tribal group at Karamoja but a small number of samples from persons who had previously lived outside the district showed immunity. Immunity was detected in sera from areas of the Northern Frontier district of Kenya. It is thought that this immunity may, in some areas, have resulted from extensions of the Ethiopian epidemic of 1960-62 into the region, but in another area of the district the immunity seems to have arisen from continuing focal transmission within Kenya. Yellow fever immunity was also detected in Somalia.