Effect of concurrent zidovudine use on the resistance pathway selected by abacavir-containing regimens

OBJECTIVES

Abacavir (ABC) selects for four mutations (K65R, L74V, Y115F and M184V) in HIV-1 reverse transcriptase (RT), both in vitro and during monotherapy in vivo. The aim of this analysis was to compare the selection of these and other nucleoside reverse transcriptase inhibitor (NRTI)-associated mutations by ABC-containing therapies in the presence and absence of concurrent lamivudine (3TC) and/or zidovudine (ZDV) and to assess the effect of these mutations on phenotypic susceptibility to the NRTIs.

DESIGN

This study was a retrospective analysis of the patterns of NRTI-associated mutations selected following virological failure in six multicentre trials conducted during the development of ABC.

METHODS

Virological failure was defined as confirmed vRNA above 400 HIV-1 RNA copies/mL. RT genotype and phenotype were determined using standard methods.

RESULTS

K65R was selected infrequently by ABC-containing regimens in the absence of ZDV (13 of 127 patients), while L74V/I was selected more frequently (51 of 127 patients). Selection of both K65R and L74V/I was significantly reduced by co-administration of ZDV with ABC (one of 86 and two of 86 patients, respectively). Y115F was uncommon in the absence (seven of 127 patients) or presence (four of 86 patients) of ZDV. M184V was the most frequently selected mutation by ABC alone (24 of 70 patients) and by ABC plus 3TC (48 of 70 patients). Thymidine analogue mutations were associated with ZDV use. The K65R mutation conferred the broadest phenotypic cross-resistance of the mutations studied.

CONCLUSIONS

The resistance pathway selected upon virological failure of ABC-containing regimens is significantly altered by concurrent ZDV use, but not by concurrent 3TC use. These data may have important implications for the efficacy of subsequent lines of NRTI therapies.

Simplest tasks have greatest dual task interference with balance in brain injured adults

Attention difficulties and poor balance are both common sequel following a brain injury. This study aimed to determine whether brain injured adults had greater difficulty than controls in performing a basic balance task while concurrently completing several different cognitive tasks varying in visuo-spatial attentional load and complexity. Twenty brain injured adults and 20 age-, sex- and education level-matched controls performed a balance-only task (step stance held for 30 s), five cognitive-only tasks (simple and complex non-spatial, visuo-spatial, and a control articulation task), and both together (dual tasks). Brain injured adults showed a greater centre of pressure (COP) excursion and velocity in all conditions than controls. Brain injured adults also demonstrated greater interference with balance when concurrently performing two cognitive tasks than control subjects. These were the control articulation and the simple non-spatial task. It is likely that distractibility during these simple tasks contributed to an increase in COP motion and interference with postural stability in stance. Performing visuo-spatial tasks concurrently with the balance task did not result in any change in COP motion. Dual task interference in this group is thus unlikely to be due to structural interference. Similarly, as the more complex tasks did not uniformly result in increased interference, a reduction in attentional capacity in the brain injured population is unlikely to be the primary cause of dual task interference in this group.

Screening for lung cancer

BACKGROUND

While population based screening for lung cancer has not been adopted by most countries, it is not clear whether sputum examinations, chest radiography or newer methods such as computed tomography are effective in reducing mortality from lung cancer.

OBJECTIVES

To determine whether screening for lung cancer using regular sputum examinations or chest radiography or CT chest reduces lung cancer mortality.

SEARCH STRATEGY

Electronic databases (the Cochrane Central Register of Controlled Trials, MEDLINE, PREMEDLINE and EMBASE; 1966 to July 2000) ), bibliographies, hand searching of a journal and discussion with experts were used to identify published and unpublished trials.

SELECTION CRITERIA

Controlled trials of screening for lung cancer using sputum examinations, chest radiography or CT chest.

DATA COLLECTION AND ANALYSIS

Intention to screen analysis was performed. Where there was significant statistical heterogeneity relative risks were reported using the random effects model, but for other outcomes the fixed effect model was used.

MAIN RESULTS

Seven trials were included (6 randomised controlled studies and 1 non-randomised controlled trial) with a total of 245,610 subjects. There were no studies with an unscreened control group. Frequent screening with chest x-rays was associated with an 11% relative increase in mortality from lung cancer compared with less frequent screening (RR 1.11, CI: 1.00-1.23). A non statistically significant trend was observed to reduced mortality from lung cancer when screening with chest x-ray and sputum cytology was compared with chest x-ray alone (RR 0.88, CI:0.74-1.03). Several of the included studies had potential methodological weaknesses. There were no controlled studies of spiral CT.

REVIEWER'S CONCLUSIONS

The current evidence does not support screening for lung cancer with chest radiography or sputum cytology. Frequent chest x-ray screening might be harmful. Further, methodologically rigorous trials are required.

Assessment of Dothistroma Needle Blight of Pinus radiata Using Airborne Hyperspectral Imagery

ABSTRACT Dothistroma needle blight is a serious foliar disease in Australian Pinus radiata plantations causing defoliation, decreased productivity and, in extreme cases, tree death. Conventional methods of monitoring forest health such as aerial survey and ground assessments are labor intensive, time consuming, and subjective. Remote sensing provides a synoptic view of the canopy and can indicate areas affected by damaging agents such as pests and pathogens. Hyperspectral airborne remote sensing imagery (CASI-2) was acquired over pine stands in southern New South Wales, Australia which had been ground assessed and ranked on an individual tree basis, according to the extent of Dothistroma needle blight. A series of spectral indices were tested using two different approaches for extracting crown-scale reflectance measurements and relating these to ground-based estimates of severity. Dothistroma needle blight is most severe in the lower crown and statistically significant relationships were found between crown reflectance values and ground estimates using a 'halo' approach (which ignored each tree crown's brightest central pixels). Independent accuracy assessment of the method indicated that the technique could successfully detect three levels of Dothistroma needle blight infection with an accuracy of over 70%.

Simplification with abacavir-based triple nucleoside therapy versus continued protease inhibitor-based highly active antiretroviral therapy in HIV-1-infected patients with undetectable plasma HIV-1 RNA

OBJECTIVE

To assess the antiviral efficacy, safety and adherence in patients switched to an abacavir-containing nucleoside reverse transcriptase inhibitor (NRTI) regimen after long-term HIV-1 RNA suppression with a dual NRTI/protease inhibitor (PI) combination.

METHODS

In an open-label, multicentre study, patients receiving 2NRTI plus PI for at least 6 months, with a history of undetectable plasma HIV-1 RNA since the initiation of therapy and plasma HIV-1 RNA < 50 copies/ml at screening, were randomly assigned to replace the PI with abacavir (n = 105) or continue the same treatment (n = 106). Clinical assessments included plasma HIV-1 RNA, chemistry, haematology, lymphocyte counts, and adverse event reports. Adherence to treatment was assessed by patient self-report.

RESULTS

A significantly longer time to treatment failure was demonstrated in the abacavir arm compared with the PI arm (P = 0.03) while treatment failure was experienced by significantly more patients in the PI arm: 24 (23%) versus 12 (12%) (P = 0.03). Therapy-limiting toxicity led to treatment failure in eight versus 14 cases in the abacavir and PI arms, respectively, whereas virological rebound was the cause in four versus two cases. Significant reductions in cholesterol and non-fasting triglyceride plasma levels at 48 weeks were observed in the abacavir arm (P < 0.001 andP = 0.035, respectively). The number of patients reporting no difficulty in taking their therapy showed a marked increase from baseline in the abacavir arm.

CONCLUSION

The replacement of PI by abacavir in a triple combination regimen following prolonged suppression of plasma HIV-1 RNA provides continued virological suppression, significant improvements in lipid abnormalities and enhanced ease of dosing.

Process evaluation of a clinical preventive nutrition intervention

BACKGROUND

We report process data on the feasibility of delivering a clinical preventive nutrition intervention that was effective in increasing participants' consumption of fruits and vegetables. We also examine relationships between process variables and study outcomes.

METHODS

We randomly assigned six practice sites in a managed care organization to a dietary intervention or control condition. We invited adults 18 years of age or older scheduled for routine health visits within the subsequent 2 months to participate. Of the 566 patients we contacted from the intervention sites, 230 (41%) enrolled. From the control sites, we contacted 617, and 274 (44%) enrolled. Intervention participants received a tailored letter providing feedback on their consumption of target foods together with recommendations for improvement, stage-matched nutrition education booklets, a diet-health endorsement from their primary care providers (PCPs), and two motivational counseling telephone calls. Of enrollees, 195 (85%) in the intervention group and 252 (92%) in the control group returned the final survey 3 months later.

RESULTS

Seventy-one percent of both participants and PCPs reported that the PCPs had discussed the relationship between diet and health at their visit. Fifty-seven percent of participants and 62% of PCPs reported that they discussed the complete diet-health endorsement, which included: (1) acknowledgment of the relationship between diet and health and (2) tailored study recommendations. The inclusion of both parts of the diet-health endorsement, but not the length of time spent, appeared to correlate with healthful outcomes.

CONCLUSIONS

These process data suggest that the brief PCP diet-health endorsement contributed to the intervention effect on fruits and vegetables.

Pain management techniques used by patients with multiple sclerosis

This study investigated the pain management techniques used by patients with multiple sclerosis. Participants from a state branch of the National Multiple Sclerosis Society completed surveys asking for their "most" and "least" effective pain management techniques. Participants then rated these techniques as to their effectiveness. Ninety percent of participants reported pain, with usual pain being in the moderate range. Typical respondents reported several effective and ineffective pain management strategies including medication, physical manipulation, exercise, psychosocial or alternative techniques, and rest/sleep. The health care and quality of life of patients with multiple sclerosis might be significantly improved if these pain experiences and strategies were to receive more clinical and research attention.

A randomized, controlled trial of remacemide for motor fluctuations in Parkinson's disease

BACKGROUND

Preclinical studies suggest that glutamate antagonists help ameliorate motor fluctuations in patients with PD treated with levodopa.

METHODS

In a multicenter, randomized, double-blind, placebo-controlled, parallel-group, dose-ranging study, the authors assessed the safety, tolerability, and efficacy of the glutamate receptor blocker remacemide hydrochloride in 279 patients with motor fluctuations treated with levodopa. The primary objective was to assess the short-term tolerability and safety of four dosage levels of remacemide during 7 weeks of treatment. Patients were also monitored with home diaries and the Unified PD Rating Scale (UPDRS) to collect preliminary data on treatment efficacy.

RESULTS

Remacemide was well tolerated up to a dosage of 300 mg/d on a twice daily schedule and 600 mg/d on a four times daily schedule. The most common dosage-related adverse events were dizziness and nausea, as observed in previous studies of remacemide. The percent "on" time and motor UPDRS scores showed trends toward improvement in the patients treated with 150 and 300 mg/d remacemide compared with placebo-treated patients, although these improvements were not significant.

CONCLUSION

Remacemide is a safe and tolerable adjunct to dopaminergic therapy for patients with PD and motor fluctuations. Although this study had limited power to detect therapeutic effects, the observed improvement is consistent with studies of non-human primates with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine-induced parkinsonian signs and symptoms. Additional studies are warranted to confirm these results over an extended period of observation, and to explore the potential neuroprotective effects of remacemide in slowing the progression of PD.

Screening for lung cancer

BACKGROUND

The effectiveness of screening for lung cancer with chest radiography, sputum cytology or spiral CT has not been established.

OBJECTIVES

To determine whether screening for lung cancer using regular sputum examinations or chest radiography or CT chest reduces lung cancer mortality.

SEARCH STRATEGY

Electronic databases, bibliographies, hand searching of a journal and discussion with experts were used to identify published and unpublished trials.

SELECTION CRITERIA

Controlled trials of screening for lung cancer using sputum examinations, chest radiography or CT chest.

DATA COLLECTION AND ANALYSIS

Intention to screen analysis was performed. Where there was significant statistical heterogeneity relative risks were reported using the random effect model, but for other outcomes the fixed effect model was used.

MAIN RESULTS

Seven trials were included (6 randomised controlled studies and 1 non-randomised controlled trial) with a total of 245,610 subjects. There were no studies with an unscreened control group. Frequent screening with chest x-rays was associated with an 11% relative increase in mortality from lung cancer compared with less frequent screening (RR 1.11, CI: 1.00-1.23). A non statistically significant trend was observed to reduced mortality from lung cancer when screening with chest x-ray and sputum cytology was compared with chest x-ray alone (RR 0.88, CI:0.74-1.03). Several of the included studies had potential methodological weaknesses. There were no controlled studies of spiral CT.

REVIEWER'S CONCLUSIONS

The current evidence does not support screening for lung cancer with chest radiography or sputum cytology. Frequent chest x-ray screening might be harmful. Further, methodologically rigorous trials are required.

Intensification of stable background therapy with abacavir in antiretroviral therapy experienced patients: 48-week data from a randomized, double-blind trial

OBJECTIVES

To evaluate antiretroviral efficacy of abacavir (ABC) in antiretroviral-experienced patients, by intensifying current antiretroviral therapy (CART) in patients with stable, detectable plasma HIV-1 RNA.

METHODS

Thirty-two European centres recruited HIV-1 positive patients with < or = 36 months of CART experience. Patients were randomized to receive either ABC (300 mg twice daily) plus CART (ABC + CART) or ABC placebo plus CART (CART). We assessed efficacy as measured by plasma HIV-1 RNA and CD4+ cell counts and safety at baseline, weeks 2, 4 and every 4 weeks thereafter until week 48. Protocol-defined criteria enabled patients to switch to open-label ABC from week 8 onwards.

RESULTS

Ninety-two patients with a median plasma of 3.66 log10 HIV-1 RNA copies/mL and a median CD4+ cell count of 408 cells/microL were randomized to ABC + CART and 93 patients with a median plasma of 3.52 log10 HIV-1 RNA copies/mL and a median CD4+ cell count of 411 cells/microL were randomized to CART. From weeks 8-48, 11 (12%) patients in the ABC + CART group and 34 (37%) patients in the CART group switched to open-label ABC. At week 48, significantly more patients on ABC + CART (23/92, 25%) than on CART (5/93, 5%) had plasma < or =400 HIV-1 RNA copies/mL (P < 0.001, intent-to-treat switch = failure population). Neither duration of previous nucleoside reverse transcriptase inhibitor treatment (up to 18 months) nor prior lamivudine therapy affected ABC efficacy. In the ABC + CART group, 16/25 (64%) patients with the M184V mutation at baseline had < or = 400 copies/mL or a decrease > or = 1 log10 copies/mL at week 16. More patients (19/46, 41%) with baseline viral load < or = 5000 copies/mL had plasma < 400 HIV-1 RNA copies/mL at 48 weeks than those > 5000 copies/mL (4/44, 9%). CD4+ cell counts increased by 102 cells/microL and 57 cells/microL at week 48 for the ABC + CART and CART groups, respectively (intent-to-treat, switch included). ABC addition had minimal impact on the CART safety profile.

CONCLUSIONS

ABC intensification, in CART-experienced patients with low viral loads and limited reverse transcriptase mutations, most of whom had previously been on double-therapy, resulted in a significant and durable plasma HIV-1 reduction and concomitant increase in CD4+ cell count. The presence of M184V at baseline had minimal impact on the efficacy of ABC.

Vaginal births after Caesarean (VBAC): a population study

This paper describes delivery outcomes for women from Victoria, Australia, who gave birth in 1995 and whose immediately previous (penultimate) delivery, within a 5-year search period, was a Caesarean section. Because of the large numbers of records involved, dedicated computer software for record linkage was used to identify the previous delivery and link it with the woman's current birth in 1995. Overall, 79% of the records from multiparous women were linked successfully. Approximately 15% were not linked because the previous birth was before the search period or was an abortion that would not have been reported to the Perinatal Data Collection Unit. Reasons for not being able to link the last 6% of the records include the previous pregnancy being overseas or interstate. Women who had a vaginal birth as the penultimate birth or a multiple birth at either event were excluded, resulting in a study population of 4663 linked records. More women (68%) had a repeat Caesarean than went into labour and, of the remaining women who laboured, 56% delivered vaginally. Overall, 18% of the women delivered vaginally. For the women who went into labour, the reported number experiencing a uterine rupture was two per 1000 births. Uterine rupture was not reported in the two-thirds who did not labour but had a repeat Caesarean. A review of the perinatal deaths identified only two deaths, one baby being born by elective Caesarean and one by a vaginal birth after a previous Caesarean (VBAC) where the choice of delivery methods may have contributed to the death. This large study is one of the few in the literature to provide population-based information on vaginal births after a previous Caesarean and related outcomes.

Tonic pupil associated with congenital neuroblastoma, Hirschsprung disease, and central hypoventilation syndrome

PURPOSE

To report the association of tonic pupil, congenital neuroblastoma, Hirschsprung disease, and central hypoventilation syndrome.

METHODS

Case reports.

RESULTS

Two infants with central hypoventilation syndrome and Hirschsprung disease were evaluated for dilated, nonreactive pupils present since birth. In both cases, pharmacologic testing with dilute pilocarpine confirmed denervation supersensitivity consistent with tonic pupil. The diagnosis of congenital neuroblastoma was subsequently established in both infants.

CONCLUSIONS

The close association of these conditions in these two young children supports the concept of a common neural crest abnormality being present. A careful systemic evaluation to rule out congenital neuroblastoma should be performed in any young child who presents with tonic pupil in the setting of central hypoventilation syndrome and Hirschsprung disease.

Power toothbrushes, gender, and dentin hypersensitivity

Power toothbrushes require less force for plaque removal than manual brushes. In addition, in vitro studies have indicated that brushing with low force could occlude patent dentin tubules by formation of a smear layer. Hence, lessening the force necessary to remove plaque may reduce dentin hypersensitivity. However, it was recently suggested that the use of an oscillating/rotating power toothbrush could decrease tooth sensitivity as compared to a sonic power toothbrush. Therefore, the objective of the present research was to compare the effect on dentin hypersensitivity of two different types of power brushes, the Optiva Sonicare and the Braun Oral B Ultra Plaque Remover. The null hypothesis was tested in an 8-week, randomized, parallel group, examiner-blind clinical trial. Fifty-nine subjects with a history of dentin hypersensitivity participated. Dentin hypersensitivity-associated pain was elicited using tactile and evaporative stimuli and assessed using a visual analog scale (VAS) instrument. Clinical examinations were carried out at screening and baseline and repeated after 8 weeks of twice daily use of the power brushes. Data analysis was performed on VAS scores obtained at the final visit following adjustment for group differences at baseline. A 35% to 40% reduction in pain as compared to baseline was observed in both treatment groups. Treatment-related differences were not statistically significant. A gender-related effect on dentin hypersensitivity was observed using the tactile stimulus and may merit further investigation.

The role of abacavir (ABC, 1592) in antiretroviral therapy-experienced patients: results from a randomized, double-blind, trial. CNA3002 European Study Team

OBJECTIVE

To compare the antiviral activity of abacavir (ABC) with stable background therapy (SBG) and SBG alone in antiretroviral therapy-experienced subjects as demonstrated by the proportion of subjects with plasma HIV-1 RNA < or = 400 copies/ml, plasma HIV-1 RNA and CD4 cell count profiles, and safety and tolerance of the two regimens over 16 weeks.

DESIGN

One-hundred and eighty-five HIV-1 infected adults, with CD4 cell counts > or = 100 x 10(6)/l and plasma HIV-1 RNA of 400-50,000 copies/ml and who had received SBG therapy for at least 12 weeks, were randomized to receive ABC (300 mg twice daily) or placebo in a double blind, multi-centre study.

METHODS

Antiretroviral activity was assessed by measuring changes in plasma HIV-1 RNA levels and CD4 cell counts. Genotypic and phenotypic resistance was determined at baseline and week 16. Evaluation of safety and tolerance was based on clinical adverse events and laboratory analyses.

RESULTS

At week 16 significantly more subjects receiving ABC + SBG had plasma HIV-1 RNA < or = 400 copies/ml (36/92, 39%) than subjects receiving SBG alone (7/93, 8%; P < 0.001). A similar response was observed in both the lamivudine naive and lamivudine-experienced subjects. The presence of the M184V mutation did not preclude an antiviral response to ABC; 73% of subjects with the M184V mutation alone experienced a > or = 1.0 log10 copies/ml reduction in plasma HIV-1 RNA or had a value of < or = 400 copies/ml by week 16.

CONCLUSIONS

ABC was generally well tolerated and exerted significant antiviral effect when added to combination antiretroviral therapy over 16 weeks.

The effects of sustained release doxycycline on the anaerobic flora and antibiotic-resistant patterns in subgingival plaque and saliva

BACKGROUND

The purpose of this study was to determine the effects of periodontal treatment with a sustained-release, biodegradable gel containing 8.5% doxycycline on the anaerobic flora and on antibiotic susceptibility patterns associated with subgingival plaque and saliva.

METHODS

Forty-five subjects with adult periodontitis were entered into a parallel design, single-blind study of 6 months' duration. The subjects were randomized to receive either doxycycline treatment (n = 23) or oral hygiene instruction/reinforcement (n = 22). Saliva and subgingival plaque samples were collected prior to and at 7, 21, 91, and 182 days after initiation of treatment. The proportion of the cultivable flora resistant to 10 microg doxycycline/ml was determined relative to total anaerobic counts, and the 3 most predominant colony types resistant to doxycycline were individually enumerated. A representative of each was subcultured, identified to genus and species level, and tested for its susceptibilities to 6 antibiotics.

RESULTS

A significant decrease (P <0.01) in total anaerobic counts following doxycycline treatment caused a transient increase in the proportion, but not in the actual counts, of doxycycline-resistant bacteria recovered from both plaque and saliva at 7 and 21 days but not at 91 or 182 days. The same doxycycline-resistant taxa were recovered at all sample periods including baseline. Regardless of treatment, the isolates were similarly distributed and belonged to the same bacterial groups.

CONCLUSIONS

Doxycycline treatment significantly reduced the anaerobic population in plaque but did not result in a change in either the number of resistant bacteria present or the acquisition of antibiotic resistance.

Resistance profile of the human immunodeficiency virus type 1 reverse transcriptase inhibitor abacavir (1592U89) after monotherapy and combination therapy. CNA2001 Investigative Group

Abacavir (1592U89) is a nucleoside inhibitor of human immunodeficiency virus (HIV) type 1 reverse transcriptase (RT). Resistance to abacavir was studied with abacavir alone and with abacavir in combination with other nucleoside analogues in cell culture, in virus isolates from zidovudine/lamivudine clinical trials, and in the first dose-escalating 12-week clinical trial (CNA2001) to evaluate abacavir clinical potency. Abacavir alone in vitro selected for mutations at HIV RT codons K65R, L74V, Y115F, and M184V. However, abacavir combined with zidovudine selected against virus with the M184V mutation. Abacavir therapy in vivo resulted in large decreases in HIV load (>1 log), even in 1 subject who had the M184V mutation at baseline. A total of 51% of subjects showed new mutations at any of codons K65R, L74V, and M184V after abacavir monotherapy, compared with 11% who received zidovudine/abacavir. Small changes (2- to 4-fold) in abacavir susceptibility were detected. On stopping therapy, reselection of the pretherapy sequence occurred within 4 weeks.

HIV-1 reverse transcriptase (RT) genotype and susceptibility to RT inhibitors during abacavir monotherapy and combination therapy

OBJECTIVE

To examine changes in HIV-1 susceptibility (genotype and phenotype) during an initial abacavir monotherapy phase followed by the addition of zidovudine and lamivudine.

DESIGN

Sixty HIV-1 infected, antiretroviral therapy-naive subjects were randomized to receive 100, 300 or 600 mg abacavir twice daily. Subjects completing 24 weeks of randomized therapy or meeting a protocol defined switch criterion could switch to open label abacavir/zidovudine/lamivudine.

METHODS

Plasma HIV-1 reverse transcriptase was genotyped at baseline, week 12, and at the last time point on ABC monotherapy. Drug susceptibility was analysed at baseline and on subsequent samples with sufficient HIV-1 RNA levels using the recombinant virus assay. Virological responses (week 24) were correlated to week 24 genotypes.

RESULTS

Mutant viruses were not detected before week 12 with the exception of one subject. At the latest time point on abacavir monotherapy (range, weeks 6-48), 21 out of 43 subjects harboured virus with resistance conferring mutations including single, double and triple combinations of K65R, L74V, Y115F and M184V. The most common mutational pattern was L74V + M184V (11/21 cases). Twenty of the 21 subjects with isolates containing abacavir-associated mutations reached week 48, and upon addition of lamivudine/zidovudiine, 16 out of 20 (80%) had week 48 plasma HIV-1 -RNA below 400 copies/ml. At week 48, 16 out of 46 genotypes were obtained; one of these was wild-type; 15 contained M184V either alone, in combination with K65R and/or L74V and/or Y115F or with thymidine analogue-associated mutations. Week 48 viral load levels for these 15 subjects was low (median 3.43 log10 copies/ml or -1.99 log10 copies reduction from baseline). Genotype correlated well with phenotypic resistance to ABC; four samples with three abacavir-associated mutations had high level abacavir resistance (> 8-fold) and six samples with two or three mutations showed intermediate (4-8-fold) resistance. All samples with single mutations retained full ABC susceptibility.

CONCLUSIONS

Resistance conferring mutations to abacavir were relatively slow to develop during the monotherapy phase, and did not preclude durable efficacy of abacavir/lamivudine/zidovudine up to 48 weeks.

Negative life experiences, depression, and immune function in abused and nonabused women

Abuse of women by their intimate partner is a staggering national problem. Abused women have a higher number of medically unexplained somatic symptoms, more functional disability, a lower self-rating of general health, and higher health care utilization when compared to nonabused women. The authors' purpose in this study was to examine differences in occurrences of negative life experiences, level of depression, and T-cell function between abused and nonabused women. The sample consisted of abused women (n = 12) and nonabused women (n = 12). Hypotheses tested were (1) abused women will have more negative life experiences than nonabused women, (2) abused women will have higher levels of depression than nonabused women, and (3) abused women will have reduced T-cell function compared to nonabused women. A cross-sectional cohort design was used to compare differences in negative life experiences, levels of depression, and T-cell function. Independent sample t-tests were performed comparing the abused versus nonabused women on the dependent measures. Significant differences were found between the groups for negative life experiences (LES; t = 2.29, p < 0.05), level of depression (BDI; t = 3.48, p < 0.01), and T-cell function (TMR; t = -5.62, p < 0.01). These findings are descriptive and do not establish causal links. However, this is an inquiry into the psychological and biobehavioral responses of women experiencing abuse and their potential health problems. The study shows that abused women reported more negative life experiences, experienced higher levels of depression, and experienced lower T-cell function when compared with nonabused women.

Ambulatory patient classifications and the regressive nature of Medicare reform: is the reduction in outpatient health care reimbursement worth the price?

PURPOSE

To evaluate the impact of the proposed Ambulatory Patient Classification (APC) system on reimbursement for hospital outpatient Medicare procedures at the Massachusetts General Hospital (MGH) Department of Radiation Oncology.

METHODS AND MATERIALS

Treatment and cost data for the MGH Department of Radiation Oncology for the fiscal year 1997 were analyzed. This represented 66,981 technical procedures and 41 CPT-4 codes. The cost of each procedure was calculated by allocating departmental costs to the relative value units (RVUs) for each procedure according to accepted accounting principles. Net reimbursement for each CPT-4 procedure was then calculated by subtracting its cost from the allowed 1998 Boston area Medicare reimbursement or from the proposed Boston area APC reimbursement. The impact of the proposed APC reimbursement system on changes in reimbursement per procedure and on volume-adjusted changes in overall net reimbursements per procedure was determined.

RESULTS

Although the overall effect of APCs on volume-adjusted net reimbursements for Medicare patients was projected to be budget-neutral, treatment planning revenues would have decreased by 514% and treatment delivery revenues would have increased by 151%. Net reimbursements for less complicated courses of treatment would have increased while those for treatment courses requiring more complicated or more frequent treatment planning would have decreased. Net reimbursements for a typical prostate interstitial implant and a three-treatment high-dose-rate intracavitary application would have decreased by 481% and 632%, respectively.

CONCLUSION

The financial incentives designed into the proposed APC reimbursement structure could lead to compromises in currently accepted standards of care, and may make it increasingly difficult for academic institutions to continue to fulfill their missions of research and service to their communities. The ability of many smaller, low patient volume, high Medicare mix hospital-based radiation oncology departments to continue to deliver their current level of care could be compromised. APC reform may carry monetary and opportunity costs which far outweigh its apparent savings. As payment systems continue to place pressure on operating margins, it becomes even more critical that both academic and community radiation oncology practices know the cost of providing services.

Factors relating to pregnant adolescents' decisions to complete a smoking cessation intervention

Adolescence is a time when young people are confronted with critical health-related decision-making responsibilities. Choices associated with smoking behavior and cessation represent one specific family of relevant adolescent decision tasks. This study examined differences between pregnant girls who decided to complete a smoking cessation intervention and those who decided not to complete the program. The comparison was made across variables representing intrapersonal, familial, and peer domains. The sample consisted of 53 pregnant teenagers. Measures included a demographic questionnaire, the Spielberger State-Trait Anxiety Inventory (STAI), and selected items from a smoking history questionnaire and the Health Behavior Questionnaire: High School Form. Significant group differences were found for age (P = .01), race (P = .05), duration of smoking (P = .02), type of smoker (P = .01), and parents' approval of teenage smoking (P = .01). A trend in differences between the two groups was evident for religious attitudes (P = .09).

An assessment of nicotine dependence among pregnant adolescents

Studies have reported that between 28 and 62% of pregnant teenagers smoke (Cornelius, Taylor, Geva, & Day, 1995; Trollestrup, Frost, & Starzyk, 1992). Because smoking is prevalent among pregnant teenagers, the purpose of this research is to assess nicotine dependence in this high-risk group. This study analyzed baseline data from a sample of pregnant teen smokers who had volunteered to participate in a smoking cessation study (N = 94). Nicotine dependence was measured by adapting the Fagerstrom Tolerance Questionnaire (FTQ; Prokhorov, Pallonen, Fava, Ding, & Niaura, 1996), and by a 6-item withdrawal symptom scale. The overall FTQ score found among pregnant adolescents was 3.10 (SD = 2.3) compared to the mean overall FTQ score among vocational-technical students of 4.27 (SD = 2.2) (Prokhorov et al., 1996). Duration of smoking in years was significantly correlated with the overall FTQ score (r = 0.43, p < .01). Quantity of smoking, as measured by average number of cigarettes smoked, significantly correlated with overall FTQ scores (r = 0.67, p < .01). Lighter smokers were more likely to have previously attempted to quit, however, among the quit attempters, those who smoked 10+ cigarettes per day reported greater severity of withdrawal symptoms than those who smoked less per day. Prenatal education and smoking cessation programs for pregnant teenagers, and pregnant women in general, need to consider that nicotine dependence is an important issue. Early pregnancy may be an opportune time to intervene among pregnant smokers; incentives may be necessary to attract those women who are the heaviest smokers, and possibly the most dependent on nicotine.