Distribution of vaccine/antivirals and the 'least spread line' in a stratified population

We describe a prioritization scheme for an allocation of a sizeable quantity of vaccine or antivirals in a stratified population. The scheme builds on an optimal strategy for reducing the epidemic's initial growth rate in a stratified mass-action model. The strategy is tested on the EpiSims network describing interactions and influenza dynamics in the population of Utah, where the stratification we have chosen is by age (0-6, 7-13, 14-18, adults). No prior immunity information is available, thus everyone is assumed to be susceptible-this may be relevant, possibly with the exception of persons over 50, to the 2009 H1N1 influenza outbreak. We have found that the top priority in an allocation of a sizeable quantity of seasonal influenza vaccinations goes to young children (0-6), followed by teens (14-18), then children (7-13), with the adult share being quite low. These results, which rely on the structure of the EpiSims network, are compared with the current influenza vaccination coverage levels in the US population.

Pharmacokinetic and pharmacodynamic modelling of the novel human granulocyte colony-stimulating factor derivative Maxy-G34 and pegfilgrastim in rats

OBJECTIVES

This study aims to compare pharmacokinetics and pharmacodynamics of pegfilgrastim, a pharmaceutical recombinant human granulocyte colony-stimulating factor (rhG-CSF), with that of a newly developed reagent, Maxy-G34. This comparison was performed using rat experiments and biomathematical modelling of granulopoiesis.

METHODS

Healthy rats and those with cyclophosphamide-induced neutropenia were treated with either pegfilgrastim or Maxy-G34 under various schedules. Time courses of absolute neutrophil count (ANC) and G-CSF serum level were measured and we constructed a combined pharmacokinetic/pharmacodynamic model of both drugs. Neutropenic episodes were assessed by experimental data and model simulations.

RESULTS

Both Pegfilgrastim and Maxy-G34 showed strong dose-dependent efficacy in reducing neutropenic episodes. However, time courses of ANC and G-CSF serum levels were markedly different. The biomathematical model showed good agreement with these data. We estimated that differences between the two drugs could be explained by lower bioavailability and reduced elimination of Maxy-G34. Based on the data and model interpolations, we estimated that Maxy-G34 is superior in reducing neutropenic episodes. Also, we predicted that G-CSF administration 48 h after cyclophosphamide would be superior to its administration after 2 or 24 h, for both derivatives.

CONCLUSION

Maxy-G34 is a highly potent drug for stimulation of neutrophil production in rats. By our modelling approach, we quantified differences between Maxy-G34 and pegfilgrastim, related to pharmacokinetic parameters. Model simulations can be used to estimate optimal dosing and timing options in the present preclinical rat model.

An open-label, dose-escalating study of Maxy-G34, a novel potent, long-acting Pegylated G-CSF, compared with pegfilgrastim (PF) for the treatment of chemotherapy induced neutropenia (CIN)

e14500

Background: rhG-CSF reduces the incidence and duration of CIN in patients (pts) receiving myelosuppressive chemotherapy. Maxy-G34 is a recombinant, modified human G-CSF, containing three 5 kD PEG groups. These modifications alter both renal and receptor mediated clearance, leading to a longer half-life and the potential for enhanced activity. Phase I studies demonstrated safety of Maxy-G34 in normal volunteers with a dose dependent rapidly reversible increase in the absolute neutrophil count (ANC). The effect of Maxy-G34 on CIN was evaluated in an open-label, active-comparator controlled, dose-ranging study. Methods: The primary efficacy endpoint was duration of severe, Grade 4 neutropenia (G4N) in treatment cycle 1. Adults with high-risk Stage I-IIIa breast cancer eligible for TAC chemotherapy received Maxy-G34 at 10, 30, 45, 60 or 100 μg/kg or the active control PF 6 mg, given sub- cutaneously 24-hours after each dose of TAC for 6 cycles. Blood samples were collected daily and analyzed at a central laboratory throughout each of the 21-day chemotherapy cycles to determine ANC and evaluate PK profile of Maxy-G34. Results: All dose groups of Maxy-G34 enrolled 6 pts each, except the 100 μg/kg group (3 pts), and the PF group (8 pts). The mean durations of G4N in cycle 1 were 2.2 days for 10 μg/kg, 1.8 days for 30 μg/kg, 0.8 days for 45 μg/kg, 2.2 days for 60 μg/kg, and 1.7 days for 100 μg/kg Maxy-G34 groups vs. 2.0 days for PF. The rate of FN was 2.6% across all Maxy-G34 doses vs. 4.2% for PF. CD34+ cell counts increased across Maxy-G34 groups following recovery from nadir with maximum concentration in treatment cycle 1 ranging from 25.8 to 133.3 cells/mL versus 49.6 cells/mL for PF. The average half-life and Cmax obtained after Maxy-G34 were approximately 2-fold higher than PF. Adverse events were consistent with those reported for G-CSF and TAC with no serious unexpected adverse events. Grade 3/4 AEs for Maxy-G34 was 9.5% vs. 8.5% for PF. No neutralizing antibodies related to Maxy-G34 were observed. Conclusion: Once-per-cycle Maxy-G34 appears to be effective in reducing CIN with no new safety signals. Further Phase II studies are planned.

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Genetic variation in the CHRNA5 gene affects mRNA levels and is associated with risk for alcohol dependence

Alcohol dependence frequently co-occurs with cigarette smoking, another common addictive behavior. Evidence from genetic studies demonstrates that alcohol dependence and smoking cluster in families and have shared genetic vulnerability. Recently a candidate gene study in nicotine dependent cases and nondependent smoking controls reported strong associations between a missense mutation (rs16969968) in exon 5 of the CHRNA5 gene and a variant in the 3'-UTR of the CHRNA3 gene and nicotine dependence. In this study we performed a comprehensive association analysis of the CHRNA5-CHRNA3-CHRNB4 gene cluster in the Collaborative Study on the Genetics of Alcoholism (COGA) families to investigate the role of genetic variants in risk for alcohol dependence. Using the family-based association test, we observed that a different group of polymorphisms, spanning CHRNA5-CHRNA3, demonstrate association with alcohol dependence defined by Diagnostic and Statistical Manual of Mental Disorders, 4th edn (DSM-IV) criteria. Using logistic regression we replicated this finding in an independent case-control series from the family study of cocaine dependence. These variants show low linkage disequilibrium with the SNPs previously reported to be associated with nicotine dependence and therefore represent an independent observation. Functional studies in human brain reveal that the variants associated with alcohol dependence are also associated with altered steady-state levels of CHRNA5 mRNA.

Poor facial affect recognition among boys with duchenne muscular dystrophy

Children with Duchenne or Becker muscular dystrophy (MD) have delayed language and poor social skills and some meet criteria for Pervasive Developmental Disorder, yet they are identified by molecular, rather than behavioral, characteristics. To determine whether comprehension of facial affect is compromised in boys with MD, children were given a matching-to-sample test with four types of visual recognition (Object, Face, Affect, and Situation matching) developed by Lucci and Fein. Within-group analyses on 50 boys with MD found decreased Affect matching relative to the other matching conditions. Between-group comparisons on 20 sibling pairs found the boys with Duchenne performed more poorly only on the Affect-matching condition. Thus, mildly impaired facial affect recognition may be part of the phenotype associated with Duchenne or Becker MD.

The experience of long-term diagnosis with human immunodeficiency virus: a stimulus to clinical eupraxia and person-centred medicine

The biopsychosocial challenges of living with human immunodeficiency virus (HIV) have changed over time and they dictate the need for relevant medical services. The meaning of an HIV diagnosis has moved from a terminal to a manageable condition with the development of antiretrovirals, bringing profound changes to the experience of living with HIV and the meaning and use of diagnostic labels. Six biological stage-related categories in the literature of psychological medicine of HIV are critiqued. Long-term HIV highlights the inadequacy of physician-centred, acute-care medicine in chronic illness and its exclusion of preventive, psychological and rehabilitative modalities. 'Eupraxia' is presented as a conceptual framework for chronic care medicine, referring to best practice, wellbeing, best interests, and (public) welfare, through facilitated but collaborative approaches. A public-centred service model is proposed, using idiographic assessment and treatment by clinicians as patient delegates (proxies), monitoring joined-up care, providing group-based biopsychosocial treatment, facilitating autonomous and self-managing behaviour by the public, removing professional and practice hierarchies, and implementing real-time clinical and managerial accountability with public ownership and involvement. This model is superior in its health-and cost-effectiveness but can only work within a nationalized system that focuses equally on standardized outcomes and evidential and personalized health outcomes.

Investigation of Poor Academic Achievement in Children with Duchenne Muscular Dystrophy

Duchenne Muscular Dystrophy (DMD) is a neurogenetic developmental disorder that presents with progressive muscular weakness. It is caused by a mutation in a gene that results in the absence of specific products that normally localize to muscle cells and the central nervous system (CNS). The majority of affected individuals have IQs within the normal range, generally with lower verbal than performance IQ scores. Prior work has demonstrated selective deficits on tests of verbal span and immediate memory. For the current study, 26 boys with DMD (and normal intellectual function) and their unaffected siblings were evaluated. Paired comparisons demonstrated that the children with DMD had significantly poorer academic achievement scores than their siblings, even though their vocabulary levels and home and educational environments were comparable. Children with DMD also had more behavioral concerns, physical disabilities, and poorer verbal memory spans. Linear regression indicated that behavioral concerns, executive function, and physical disability did not contribute substantially to academic performance, whereas performance on verbal span did. DMD presents with a selective developmental aberration in verbal span that has wide-ranging consequences on learning skills.

A cornucopia of cycloadducts: theoretical predictions of the mechanisms and products of the reactions of cyclopentadiene with cycloheptatriene

The potential cycloaddition reactions between cyclopentadiene and cycloheptatriene have been explored theoretically. B3LYP/6-31G was used to locate the transition states, intermediates, and products for concerted pathways and stepwise pathways passing through diradical intermediates. Interconversions of various cycloadducts through sigmatropic shifts were also explored. CASPT2/6-31G single point calculations were employed to obtain independent activation energy estimates. MM3 was also used to compute reaction energetics. Several bispericyclic cycloadditions in which two cycloadducts are linked by a sigmatropic shift have been identified. B3LYP predicts, in line with frontier molecular orbital predictions, that the [6+4] cycloaddition is the favored concerted pathway, but an alternative [4+2] pathway is very close in energy. By contrast, CASPT2 predicts that a [4+2] cycloaddition is the preferred pathway. B3LYP predicts that the lowest energy path to many of the cycloadducts will involve diradical intermediates, whereas CASPT2 predicts that each of the products of orbital symmetry allowed reactions will be reached most readily by closed shell processes-concerted cycloadditions and sigmatropic shift rearrangements of cycloadducts.

Application of comparative genomic hybridization in search for genetic aberrations in fibroadenomas of the breast

We applied a comparative genomic hybridization (CGH) technique to paraffin-embedded tissue samples taken from fibroadenomas, benign breast tumors, to detect possible numerical and unbalanced genetic changes. We compared the results to those from previous cytogenetic studies of fibroadenomas. In concurrence with previous cytogenetic studies of fibroadenomas, we detected genetic aberrations in chromosomes 4-6, 8-13, 16, 18, 19, 20, and 22. In addition, with the CGH technique we were able to find two new aberrations, 15q+ and 16p-. Because these aberrations have also been reported to be present in breast cancer, the importance of this finding is yet to be determined.

In vitro activities of newer quinolones against bacteroides group organisms

The activities of BMS-284576, clinafloxacin, moxifloxacin, sitafloxacin, trovafloxacin, imipenem, cefoxitin, and clindamycin against 589 Bacteroides fragilis group isolates were determined. The activity of BMS-284576 was comparable to that of trovafloxacin. Sitafloxacin and clinafloxacin were the most active quinolones, and moxifloxacin was the least active. B. fragilis was the most susceptible of the species, and Bacteroides vulgatus was the most resistant. Association of specific antibiotic resistance with Bacteroides species was noted for all quinolones.

Reporting of CAHPS quality information to medicare beneficiaries

OBJECTIVES

To assess which Consumer Assessment of Health Plans (CAHPS) survey measures Medicare beneficiaries find the most meaningful, how beneficiaries and information intermediaries interpret different formats for presenting CAHPS information, and how beneficiaries have reacted to the CAHPS information included in the annual mailing to beneficiaries called Medicare & You 2000.

DATA SOURCES

Fourteen focus groups of beneficiaries and State Health Insurance Assistance Program counselors, more than 200 cognitive interviews, and 122 mall-intercept interviews with beneficiaries were conducted from spring 1998 through winter 2000.

STUDY DESIGN

In 1998 focus groups and cognitive interviews were conducted with Medicare beneficiaries and State Health Insurance Assistance Program counselors to determine which CAHPS measures to report to Medicare beneficiaries and how to report this information. In 1999 additional focus groups and mall-intercept interviews were conducted to determine which measures to include in Medicare & You 2000. To obtain feedback on the CAHPS information in Medicare & You 2000 additional focus groups were conducted in winter 2000.

PRINCIPAL FINDINGS

Focus group participants indicated that getting the care they need quickly, having access to specialists, and communicating well with doctors were more important to them than nonmedical characteristics of plans. Most beneficiaries had problems interpreting quality information. Many misinterpreted star charts, and while bar charts appear easier to read, many beneficiaries still had trouble interpreting the information on these charts. Most beneficiaries did not consider quality information important to them and most were unaware of the availability of CAHPS information.

CONCLUSIONS

Many challenges lie ahead in making quality information meaningful to Medicare beneficiaries. These challenges include increasing awareness of the existence of this information, educating beneficiaries about how this information can help in choosing a health plan, continuing to simplify reporting formats, assuring beneficiaries that this information comes from a credible source, and providing guidance to beneficiaries about how quality information can help with health care decisions.

Use of Medicaid 1915(c) home- and community-based care waivers to reconfigure state long-term care systems

Since Congressional authorization in 1981, Medicaid 1915(c) home- and community-based care waivers have influenced states' efforts to transform their long-term care systems. In 1997, every state participated in the 1915(c) waiver program, while waiver expenditures, at $8.1 billion, represented 59.6 percent of all Medicaid community-based care expenditures. To explore state-level factors that appear related to these expenditures, the authors turn to a body of work on Medicaid resource allocation. They compare the influence of five factors--sociodemographic, supply, economic, programmatic, and political environment--on states' allocations to long-term care expenditures and 1915(c) waiver expenditures. The state economic environment was an important influence on total, as well as waiver expenditures. State regulation of long-term care supply demonstrated the most substantive relationship, increasing the share of dollars supporting 1915(c) waivers from 11.6 to 20.0 over the study period, all else equal.

Screening and surveillance colonoscopy in chronic Crohn's colitis

BACKGROUND & AIMS

Unlike ulcerative colitis, there are few reports on the efficacy of surveillance colonoscopy in patients with chronic Crohn's colitis and therefore little agreement as to whether routine surveillance is indicated. We report on 259 patients with chronic Crohn's colitis who underwent screening and subsequent surveillance colonoscopy and biopsy since 1980.

METHODS

Biopsies were performed at 10-cm intervals and from strictures and polypoid masses. Pathology was classified as normal, dysplasia (indefinite, low-grade, high-grade), or carcinoma.

RESULTS

A total of 663 examinations were performed on 259 patients. The median interval between examinations was 24 months; examinations were performed more frequently (1-6 months) in patients with dysplasia on biopsy. A thinner-caliber colonoscope was required to complete 12% of screening examinations and 23% of surveillance examinations. The pediatric colonoscope helped increase our yield of neoplasia by 19%. The screening and surveillance program detected dysplasia or cancer in 16% (10 indefinite, 23 low-grade, and 4 high-grade dysplasias and 5 cancers). A finding of definite dysplasia or cancer was associated with age >45 years and increased symptoms. By life table analysis, the probability of detecting dysplasia or cancer after a negative screening colonoscopy was 22% by the fourth surveillance examination.

CONCLUSIONS

Colonoscopic surveillance should be strongly considered in chronic extensive Crohn's colitis.

Lessons learned from the National Medicare & You Education Program

In fall 1998 CMS implemented the National Medicare Education Program (NMEP) to educate beneficiaries about their Medicare program benefits; health plan choices; supplemental health insurance; beneficiary rights, responsibilities, and protections; and health behaviors. CMS has been monitoring the implementation of the NMEP in six case study sites as well as monitoring each of the information channels for communicating with beneficiaries. This article describes select findings from the case studies, and highlights from assessment activities related to the Medicare & You handbook, the toll-free 1-800-MEDICARE Helpline, Internet, and Regional Education About Choices in Health (REACH).

Selective deficits in verbal working memory associated with a known genetic etiology: the neuropsychological profile of duchenne muscular dystrophy

Forty-one boys diagnosed with Duchenne muscular dystrophy (DMD) were each compared to an unaffected sibling on a battery of neuropsychological tests. Verbal. visuospatial, attention/memory, abstract thinking, and academic achievement skills were tested. Results indicated the boys with DMD performed similarly to their siblings on the majority of measures, indicating intact verbal, visuospatial, long-term memory, and abstract skills. However, the DMD group did significantly more poorly than their siblings on specific measures of story recall, digit span, and auditory comprehension, as well as in all areas of academic achievement (reading, writing, and math). This profile indicates that verbal working memory skills are selectively impaired in DMD, and that that likely contributes to limited academic achievement. The association between the known impact of the genetic mutation on the development of the central nervous system and boys' cognitive profile is discussed.

Poor verbal working memory across intellectual level in boys with Duchenne dystrophy

OBJECTIVE

To determine whether all boys with Duchenne muscular dystrophy (DMD) have a similar verbal and memory profile of skills, or whether only a subset is affected, and to determine whether the weak areas in their profile are substantially different from a control group.

METHODS

Performance of patients with DMD on neuropsychological tests of verbal and memory skills was examined in two ways. Standardized test scores for 80 boys with DMD (estimated IQ range, 70 to 160) were ranked individually from worst to best, and the individual rankings were compared across the group using Friedman rank analysis. Additionally, performance of 41 boys with DMD was compared with that of their sibling control subjects of similar age and estimated IQ using multivariate analysis of variance.

RESULTS

Individual cognitive profiles were significantly similar among the subjects with DMD, such that for most subjects digit span, story recall, and comprehension were the tests on which each performed most poorly. This finding remained true regardless of whether they were of high or low intellectual function. In contrast, no significant cognitive profile was found among their sibling control subjects, and when compared with their siblings, the DMD group scored significantly more poorly on digit span, comprehension, and story recall, but not on other verbal and memory measures.

CONCLUSIONS

Boys with DMD have a specific cognitive profile, regardless of their general level of cognitive function. Specifically, boys with DMD performed more poorly on tests requiring attention to complex verbal information than they did on other verbal or memory measures. The possibility that the missing dystrophin brain products may contribute to selective cognitive processing is considered.

Minimal heparinization in coronary angioplasty--how much heparin is really warranted?

The purpose of the study was to assess the results of percutaneous transluminal coronary angioplasty (PTCA), performed with a single intravenous bolus of 2,500 U of heparin, in a nonemergency PTCA cohort. Three hundred of 341 consecutive patients (87.9%) undergoing PTCA were prospectively enrolled in the study. They received heparin, 2,500-U intravenous bolus, before PTCA, with intention of no additional heparin administration. Patient and lesion characteristics as well as PTCA results were evaluated independently by 2 physicians. Patients were followed up by structured telephone questionnaires at 1 and 6 months after PTCA. Mean activated clotting time obtained 5 minutes after heparin administration was 185+/-19 seconds (range 157 to 238). There were 3 (1%) in-hospital major adverse cardiovascular events: 2 deaths (0.66%), 1 (0.33%) Q-wave myocardial infarction. Emergency coronary surgery and stroke were not reported. Six patients (2%) experienced abrupt coronary occlusion within 14 days after PTCA, warranting repeat target vessel revascularization. Angiographic and clinical success were achieved in 96% and 93.3%, respectively. No bleeding or vascular complications were recorded. Six-month follow-up (184 patients) revealed 3 cardiac deaths (1 arrhythmic, 2 after cardiac surgery), 1 Q-wave myocardial infarction, and 9.7% repeat target vessel revascularization. This study suggests that very low doses of heparin and reduced activated clotting time target values are safe in non-emergency PTCA, and can reduce bleeding complications, hospital stay, and costs. Larger, randomized, double-blind heparin dose optimization studies need to confirm this notion.

Colonoscopic polypectomy in chronic colitis: conservative management after endoscopic resection of dysplastic polyps

BACKGROUND & AIMS

Adenomatous polyps are by definition dysplastic and pathologically indistinguishable from the dysplasia-associated lesion or mass (DALM) described in 1981. Yet, adenomatous polyps in noncolitic colons are usually removed definitively endoscopically, whereas DALMs are regarded as harbingers of colon cancer, mandating colectomy.

METHODS

Since 1988, all of our patients with chronic ulcerative or Crohn's colitis and dysplastic polyps and no coexistent dysplasia in flat mucosa underwent colonoscopic polypectomy. Biopsy specimens were obtained also adjacent to polypectomy sites, from strictures, and throughout the colon at 10-cm intervals. Follow-up colonoscopies and biopsies were performed within 6 months after polypectomy and yearly thereafter.

RESULTS

Colonoscopy in 48 patients with chronic colitis (mean duration, 25.4 years) resected 70 polyps (60 in colitic and 10 in noncolitic mucosa). Polyps were detected on screening colonoscopies (29%) and on surveillance (71%). Pathology was tubular adenoma in all polyps from noncolitic mucosa and low-grade dysplasia (57), high-grade dysplasia (2), or carcinoma (1) in polyps from colitic mucosa. Subsequent colonoscopies (mean follow-up, 4.1 years) revealed additional polyps in 48% but no carcinomas. Surgical resection (6 patients) for recurrent polyps confirmed colonoscopic findings. No dysplasia or cancers in flat mucosa were found at surgery or on follow-up colonoscopies.

CONCLUSIONS

In patients with chronic colitis who have no dysplasia in flat mucosa, colonoscopic resection of dysplastic polyps can be performed effectively, just as in noncolitic colons.

Comparison of human sera reactivities in immunoblots with recombinant human herpesvirus (HHV)-8 proteins associated with the latent (ORF73) and lytic (ORFs 65, K8.1A, and K8.1B) replicative cycles and in immunofluorescence assays with HHV-8-infected BCBL-1 cells

The development of reliable, sensitive, and specific serological methods for the detection of human herpesvirus-8 (HHV-8) antibodies is critical for a thorough understanding of HHV-8 prevalence and pathogenesis. To evaluate the potential usefulness of HHV-8 proteins in measuring the responses against both latent and lytic antigens, we selected 1 latent [open reading frame (ORF) 73] antigen and 3 HHV-8 lytic antigens (ORFs 65, K8.1A, and K8.1B) previously identified as immunogenic [Virology (1998) 243, 208-217]. Full-length genomic ORF 73 and full-length ORFs 65, K8.1A, and K8.1B from the cDNA clones were cloned, expressed in bacterial and baculovirus-insect cell expression systems, and purified as GST fusion proteins. These recombinant proteins were used in Western blot reactions to test sera from 104 human immunodeficiency virus (HIV)+/Kaposi's sarcoma (KS)+ homosexual men, 77 HIV+/KS- homosexual men, and 84 age-matched HIV-/KS- men. These sera were also tested in immunofluorescence assays (IFAs) with uninduced and 12-O-tetradecanoylphorbol-13-acetate-induced B cell lymphoma-1 cells to detect antibodies against latency-associated nuclear antigens (LANA) and antibodies against lytic antigens (cytoplasmic fluorescence). These sera exhibited differential reactivities reflecting different titers of antibodies against HHV-8 proteins, and variable reactivities were seen more commonly with the sera from HIV-/KS- adult men. In the Western blot assay, 89% (93 of 104) of HIV+/KS + sera, 60% (46 of 77) of HIV+/KS- sera, and 7% (6 of 84) HIV+/KS- sera were reactive with both latent and lytic recombinant antigens. Western blot reactions with ORF 73 protein were more sensitive than LANA-IFA results. The lytic IFA and lytic Western blot (ORFs 65 and K8.1A) assays were more sensitive than the ORF 73 Western blots and LANA-IFA. With an exception of 2 sera from the HIV-/KS- group, all sera positive for lytic IFA antibodies and ORF 65 and K8.1A antibodies were also positive for latent antibodies. With few exceptions, sera positive for ORF 65 antibodies were also positive for K8.1A antibodies, and sera recognized the K8.1A protein more often than the K8.1B protein. There is a high degree of concordance between IFA and Western blot reactions, suggesting that this panel of HHV-8 recombinant proteins could detect a majority of the HHV-8-seropositive individuals. These results suggest that IFA followed by confirmation with the Western blot reactions with a panel of latent and lytic immunogenic antigens would provide a reliable, sensitive, and specific method for the detection of HHV-8 antibodies.