The most common symptoms in patients with breast cancer metastases are identified and an overview of their management is provided.

Approximately 40,000 women die as a result of breast cancer each year and many more live with advanced disease. When breast cancer recurs, the goals of treatment often shift from one of cure to controlling the disease for as long as possible while palliating symptoms interfering with the patient's functional status and quality of life. This requires ongoing discussions with the patient and family about the goals of care. Many symptoms depend on the site of metastasis, with bone being the most frequent, and commonly occur with fatigue, depression, insomnia, and pain. The purpose of this paper is to identify and provide an overview of the management of the most common symptoms in patients with breast cancer metastases.

Objective:

Since Alzheimer disease (AD) neuropathology is thought to develop years before dementia, it may be possible to detect subtle AD-related atrophy in preclinical AD. Here we hypothesized that the “disease signature” of AD-related cortical thinning, previously identified in patients with mild AD dementia, would be useful as a biomarker to detect anatomic abnormalities consistent with AD in cognitively normal (CN) adults who develop AD dementia after longitudinal follow-up.

Methods:

We studied 2 independent samples of adults who were CN when scanned. In sample 1, 8 individuals developing AD dementia (CN-AD converters) after an average of 11.1 years were compared to 25 individuals who remained CN (CN-stable). In sample 2, 7 CN-AD converters (average follow-up 7.1 years) were compared to 25 CN-stable individuals.

Results:

AD-signature cortical thinning in CN-AD converters in both samples was remarkably similar, about 0.2 mm (p < 0.05). Despite this small absolute difference, Cohen d effect sizes for these differences were very large (>1). Of the 11 CN individuals with baseline low AD-signature thickness (≥1 SD below cohort mean), 55% developed AD dementia over nearly the next decade, while none of the 9 high AD-signature thickness individuals (≥1 SD above mean) developed dementia. This marker predicted time to diagnosis of dementia (hazard ratio = 3.4, p < 0.0005); 1 SD of thinning increased dementia risk by 3.4.

Conclusions:

By focusing on cortical regions known to be affected in AD dementia, subtle but reliable atrophy is identifiable in asymptomatic individuals nearly a decade before dementia, making this measure a potentially important imaging biomarker of early neurodegeneration.

Purpose

Factors captured in a geriatric assessment can predict morbidity and mortality in older adults, but are not routinely measured in cancer clinical trials. This study evaluated the implementation of a geriatric assessment tool in the cooperative group setting.

Patients and Methods

Patients age ≥ 65 with cancer, who enrolled on cooperative group cancer trials, were eligible to enroll on Cancer and Leukemia Group B (CALGB) 360401. They completed a geriatric assessment tool before initiation of protocol therapy, consisting of valid and reliable geriatric assessment measures which are primarily self-administered and require minimal resources and time by healthcare providers. The assessment measures functional status, comorbidity, cognitive function, psychological state, social support, and nutritional status. The protocol specified criteria for incorporation of the tool in future cooperative group trials was based on the time to completion and percent of patients who could complete their portion without assistance. Patient satisfaction with the tool was captured.

Results

Of the 93 patients who enrolled in this study, five (5%) met criteria for cognitive impairment and three did not complete the cognitive screen, leaving 85 assessable patients (median age, 72 years). The median time to complete the geriatric assessment tool was 22 minutes, 87% of patients (n = 74) completed their portion without assistance, 92% (n = 78) were satisfied with the questionnaire length, 95% (n = 81) reported no difficult questions, and 96% (n = 82) reported no upsetting questions. One hundred percent of health care professionals completed their portion.

Conclusion

This brief, primarily self-administered geriatric assessment tool met the protocol specified criteria for inclusion in future cooperative group clinical trials.

Purpose

A phase III trial (Cancer and Leukemia Group B CALGB-49907) was conducted to test whether older patients with early-stage breast cancer would have equivalent relapse-free and overall survival with capecitabine compared with standard chemotherapy. The quality of life (QoL) substudy tested whether capecitabine treatment would be associated with a better QoL than standard chemotherapy.

Patients and Methods

QoL was assessed in 350 patients randomly assigned to either standard chemotherapy (cyclophosphamide, methotrexate, and fluorouracil [CMF] or doxorubicin and cyclophosphamide [AC]; n = 182) or capecitabine (n = 168). Patients were interviewed by telephone before treatment (baseline), midtreatment, within 1 month post-treatment, and at 12, 18, and 24 months postbaseline by using questionnaires from the European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire C30 (EORTC QLQ-C30), a breast systemic adverse effects scale (EORTC BR23), and the Hospital Anxiety and Depression Scale (HADS).

Results

Compared with patients who were treated with standard chemotherapy, patients who were treated with capecitabine had significantly better QoL, role function, and social function, fewer systemic adverse effects, less psychological distress, and less fatigue during and at the completion of treatment (P ≤ .005). Capecitabine treatment was associated with less nausea, vomiting, and constipation and with better appetite than standard treatment (P ≤ .004), but worse hand-foot syndrome and diarrhea (P < .005). These differences all resolved by 12 months.

Conclusion

Standard chemotherapy was superior to capecitabine in improving relapse-free and overall survival for older women with early-stage breast cancer. Although capecitabine was associated with better QoL during treatment, QoL was similar for both groups at 1 year. The brief period of poorer QoL with standard treatment is a modest price to pay for a chance at improved survival.

Background

Tamoxifen is standard adjuvant treatment for postmenopausal women with hormone receptor-positive breast cancer. The benefit of adding chemotherapy and optimal timing of tamoxifen with chemotherapy are unknown.

Methods

We conducted a parallel randomized phase III trial in postmenopausal women with hormone receptor-positive, node-positive breast cancer to test whether disease-free survival (DFS) with cyclophosphamide, doxorubicin (AdriamycinR), and 5-fluorouracil (CAF) plus 5 years of tamoxifen was longer than with tamoxifen alone; and whether DFS with CAF followed by tamoxifen (CAF-T) was better than CAF plus concurrent tamoxifen (CAFT). Overall survival and toxicity were predefined, important secondary outcomes. Randomization was a 2:3:3 (T:CAF-T:CAFT) unblinded allocation and analysis was by intention to treat. This trial is registered with ClinicalTrials.gov, number NCT00929591.

Findings

Of 1558 women randomized, 1477 (95%) were eligible (tamoxifen, 361; CAF-T, 566; CAFT, 550). The combined CAF groups were superior to tamoxifen for the primary outcome of DFS (P=0.002), with adjusted Cox regression hazard ratio (HR) =0.76 (95% CI 0.64,0.91). CAF-T was marginally better than CAFT for DFS (P=0.055) with adjusted HR 0.84 (0.70,1.01). Ten-year DFS for CAF-T, CAFT, and T were 60%, 53%, and 48%, respectively. The planned secondary outcome, overall survival, showed a similar pattern of results, with combined CAF groups seem superior to tamoxifen [p=0.043, adjusted HR 0.83 (0.68,1.01)]. Neutropenia, stomatitis, thromboembolism, congestive heart failure and leukemia were more frequent with CAF than tamoxifen alone.

Interpretation

Chemotherapy with CAF plus tamoxifen resulted in longer survival over tamoxifen in endocrine-responsive, node-positive breast cancer, with greater benefit when tamoxifen followed CAF.

Funding

National Cancer Institute (NIH-USA).

BACKGROUND

Older women with breast cancer are underrepresented in clinical trials, and data on the effects of adjuvant chemotherapy in such patients are scant. We tested for the noninferiority of capecitabine as compared with standard chemotherapy in women with breast cancer who were 65 years of age or older.

METHODS

We randomly assigned patients with stage I, II, IIIA, or IIIB breast cancer to standard chemotherapy (either cyclophosphamide, methotrexate, and fluorouracil or cyclophosphamide plus doxorubicin) or capecitabine. Endocrine therapy was recommended after chemotherapy in patients with hormone-receptor–positive tumors. A Bayesian statistical design was used with a range in sample size from 600 to 1800 patients. The primary end point was relapse-free survival.

RESULTS

When the 600th patient was enrolled, the probability that, with longer follow-up, capecitabine therapy was highly likely to be inferior to standard chemotherapy met a prescribed level, and enrollment was discontinued. After an additional year of follow-up, the hazard ratio for disease recurrence or death in the capecitabine group was 2.09 (95% confidence interval, 1.38 to 3.17; P<0.001). Patients who were randomly assigned to capecitabine were twice as likely to have a relapse and almost twice as likely to die as patients who were randomly assigned to standard chemotherapy (P = 0.02). At 3 years, the rate of relapse-free survival was 68% in the capecitabine group versus 85% in the standard-chemotherapy group, and the overall survival rate was 86% versus 91%. Two patients in the capecitabine group died of treatment-related complications; as compared with patients receiving capecitabine, twice as many patients receiving standard chemotherapy had moderate-to-severe toxic effects (64% vs. 33%).

CONCLUSIONS

Standard adjuvant chemotherapy is superior to capecitabine in patients with early-stage breast cancer who are 65 years of age or older. (ClinicalTrials.gov number, NCT00024102.)

Background:

Amyloid-beta protein (Aβ) plays a key role in Alzheimer disease (AD) and is also implicated in cerebral small vessel disease. Serum total homocysteine (tHcy) is a risk factor for small vessel disease and cognitive impairment and correlates with plasma Aβ levels. To determine whether this association results from a common pathophysiologic mechanism, we investigated whether vitamin supplementation–induced reduction of tHcy influences plasma Aβ levels in the Vitamin Intervention in Stroke Prevention (VISP) study.

Methods:

Two groups of 150 patients treated with either the high-dose or low-dose formulation of pyridoxine, cobalamin, and folic acid in a randomized, double-blind fashion were selected among the participants in the VISP study without recurrent stroke during follow-up and in the highest 10% of the distribution for baseline tHcy levels. Concentrations of plasma Aβ with 40 (Aβ40) and 42 (Aβ42) amino acids were measured at baseline and at the 2-year visit.

Results:

tHcy levels significantly decreased with vitamin supplementation in both groups. tHcy were strongly correlated with Aβ40 but not Aβ42 concentrations. There was no difference in the change in Aβ40, Aβ42 (p = 0.40, p = 0.35), or the Aβ42/Aβ40 ratio over time (p = 0.86) between treatment groups. Aβ measures were not associated with cognitive change.

Conclusions:

This double-blind randomized controlled trial of vitamin therapy demonstrates a strong correlation between serum tHcy and plasma Aβ40 concentrations in subjects with ischemic stroke. Treatment with high dose vitamins does not, however, influence plasma levels of Aβ, despite their effect on lowering tHcy. Our results suggest that although tHcy is associated with plasma Aβ40, they may be regulated by independent mechanisms.

GLOSSARY

= amyloid-beta;

= Alzheimer disease;

= body mass index;

= diastolic blood pressure;

= Mini-Mental State Examination;

= modified Rankin Scale;

= NIH Stroke Scale;

= systolic blood pressure;

= total homocysteine;

= Vitamin Intervention in Stroke Prevention study.

Background:

Multiple lines of research suggest that increased cystatin C activity in the brain protects against the development of Alzheimer disease (AD).

Methods:

Serum cystatin C levels were analyzed at two examinations of the Uppsala Longitudinal Study of Adult Men, a longitudinal, community-based study of elderly men (age 70 years, n = 1,153 and age 77 years, n = 761, a subset of the age 70 examination). Cox regressions were used to examine associations between serum cystatin C and incident AD. AD cases were identified by cognitive screening and comprehensive medical chart review in all subjects.

Results:

On follow-up (median 11.3 years), 82 subjects developed AD. At age 70 years, lower cystatin C was associated with higher risk of AD independently of age, APOE4 genotype, glomerular filtration rate, diabetes, hypertension, stroke, cholesterol, body mass index, smoking, education level, and plasma amyloid-β protein 40 and 42 levels (hazard ratio [HR] for lowest [<1.12 μmol/L] vs highest [>1.30 μmol/L] tertile = 2.67, 95% CI 1.22–5.83, p < 0.02). The results were similar at age 77 years (43 participants developed AD during follow-up). Furthermore, a 0.1-μmol/L decrease of cystatin C between ages 70 and 77 years was associated with a 29% higher risk of incident AD (HR 1.29, 95% CI 1.03–1.63, p < 0.03).

Conclusions:

Low levels of serum cystatin C precede clinically manifest Alzheimer disease (AD) in elderly men free of dementia at baseline and may be a marker of future risk of AD. These findings strengthen the evidence for a role for cystatin C in the development of clinical AD.

GLOSSARY

= amyloid-β protein 40;

= amyloid-β protein 42;

= Alzheimer disease;

= body mass index;

= glomerular filtration rate;

= hazard ratio;

= International Classification of Diseases;

= Uppsala Longitudinal Study of Adult Men.

Background

Older women with early-stage breast cancer experience higher rates of non—breast cancer-related death. We examined factors associated with cause-specific death in a large cohort of breast cancer patients treated with extended adjuvant endocrine therapy.

Methods

In the MA.17 trial, conducted by the National Cancer Institute of Canada Clinical Trials Group, 5170 breast cancer patients (median age = 62 years; range = 32–94 years) who were disease free after approximately 5 years of adjuvant tamoxifen treatment were randomly assigned to treatment with letrozole (2583 women) or placebo (2587 women). The median follow-up was 3.9 years (range = 0–7 years). We investigated the association of 11 baseline factors with the competing risks of death from breast cancer, other malignancies, and other causes. All statistical tests were two-sided likelihood ratio criterion tests.

Results

During follow-up, 256 deaths were reported (102 from breast cancer, 50 from other malignancies, 100 from other causes, and four from an unknown cause). Non—breast cancer deaths accounted for 60% of the 252 known deaths (72% for those ≥70 years and 48% for those <70 years). Two baseline factors were differentially associated with type of death: cardiovascular disease was associated with a statistically significant increased risk of death from other causes (P = .002), and osteoporosis was associated with a statistically significant increased risk of death from other malignancies (P = .05). An increased risk of breast cancer—specific death was associated with lymph node involvement (P < .001). Increased risk of death from all three causes was associated with older age (P < .001).

Conclusions

Non—breast cancer-related deaths were more common than breast cancer—specific deaths in this cohort of 5-year breast cancer survivors, especially among older women.

Background:

Extrapyramidal motor symptoms precede dementia in Parkinson disease (PDD) by many years, whereas dementia occurs early in dementia with Lewy bodies (DLB). Despite this clinical distinction, the neuropsychological and neuropathologic features of these conditions overlap. In addition to widespread distribution of Lewy bodies, both diseases have variable burdens of neuritic plaques and neurofibrillary tangles characteristic of Alzheimer disease (AD).

Objectives:

To determine whether amyloid deposition, as assessed by PET imaging with the β-amyloid–binding compound Pittsburgh Compound B (PiB), can distinguish DLB from PDD, and to assess whether regional patterns of amyloid deposition correlate with specific motor or cognitive features.

Methods:

Eight DLB, 7 PDD, 11 Parkinson disease (PD), 15 AD, and 37 normal control (NC) subjects underwent PiB-PET imaging and neuropsychological assessment. Amyloid burden was quantified using the PiB distribution volume ratio.

Results:

Cortical amyloid burden was higher in the DLB group than in the PDD group, comparable to the AD group. Amyloid deposition in the PDD group was low, comparable to the PD and NC groups. Relative to global cortical retention, occipital PiB retention was lower in the AD group than in the other groups. For the DLB, PDD, and PD groups, amyloid deposition in the parietal (lateral and precuneus)/posterior cingulate region was related to visuospatial impairment. Striatal PiB retention in the DLB and PDD groups was associated with less impaired motor function.

Conclusions:

Global cortical amyloid burden is high in dementia with Lewy bodies (DLB) but low in Parkinson disease dementia. These data suggest that β-amyloid may contribute selectively to the cognitive impairment of DLB and may contribute to the timing of dementia relative to the motor signs of parkinsonism.

GLOSSARY

= Automated Anatomic Labeling;

= Alzheimer disease;

= Alzheimer’s Disease Research Center;

= American version of the National Adult Reading Test;

= analysis of covariance;

= Blessed Dementia Scale;

= cerebral amyloid angiopathy;

= Clinical Dementia Rating;

= Clinical Dementia Rating Sum of Boxes;

= dementia with Lewy bodies;

= distribution volume ratio;

= Cued Selective Reminding Test;

= Free Selective Reminding Test;

= Hoehn and Yahr;

= Massachusetts General Hospital;

= Mini-Mental State Examination;

= normal control;

= neurofibrillary tangle;

= Neuropsychiatric Inventory Questionnaire;

= not significant;

= Parkinson disease;

= Parkinson disease dementia;

= Pittsburgh Compound B;

= region of interest;

= Statistical Parametric Mapping;

= UK Parkinson’s Disease Society Brain Bank Research Center;

= United Parkinson’s Disease Rating Scale;

= Wechsler Adult Intelligence Scale–Revised.

Background:

MRI studies have demonstrated differential rates of atrophy in the entorhinal cortex and hippocampus during the prodromal phase of Alzheimer disease (AD). The current study was designed to determine whether a broader set of temporoparietal regions show differential rates of atrophy during the evolution of AD.

Methods:

Sixteen regions of interest (ROIs) were analyzed on MRI scans obtained at baseline and follow-up in 66 subjects comprising three groups: controls = individuals who were cognitively normal at both baseline and follow-up; nonconverters = subjects with mild cognitive impairment (MCI) at both baseline and follow-up; converters had MCI at baseline but had progressed to AD at follow-up.

Results:

Annualized percent change was analyzed with multivariate analysis of variance (MANOVA), covaried for age. The MANOVA demonstrated an effect of group (p = 0.004). Post hoc comparisons demonstrated greater rates of atrophy for converters vs nonconverters for six ROIs: hippocampus, entorhinal cortex, temporal pole, middle temporal gyrus, fusiform gyrus, and inferior temporal gyrus. Converters showed differentially greater rates of atrophy than controls in five of the same ROIs (and inferior parietal lobule). Rates of change in clinical status were correlated with the atrophy rates in these regions. Comparisons between controls and nonconverters demonstrated no differences.

Conclusion:

These results demonstrate that temporoparietal regions show differential rates of atrophy on MRI during prodromal Alzheimer disease (AD). MRI data correlate with measures of clinical severity and cognitive decline, suggesting the potential of these regions of interest as antemortem markers of prodromal AD.

GLOSSARY

= Alzheimer disease;

= annualized percent change;

= Clinical Dementia Rating Sum of Boxes;

= California Verbal Learning Test;

= multivariate analysis of variance;

= mild cognitive impairment;

= region of interest;

= Selective Reminding Test.

Background

Extrapyramidal motor symptoms precede dementia in Parkinson disease (PDD) by many years, whereas dementia occurs early in dementia with Lewy bodies (DLB). Despite this clinical distinction, the neuropsychological and neuropathologic features of these conditions overlap. In addition to widespread distribution of Lewy bodies, both diseases have variable burdens of neuritic plaques and neurofibrillary tangles characteristic of Alzheimer disease (AD).

Objectives

To determine whether amyloid deposition, as assessed by PET imaging with the β-amyloid–binding compound Pittsburgh Compound B (PiB), can distinguish DLB from PDD, and to assess whether regional patterns of amyloid deposition correlate with specific motor or cognitive features.

Methods

Eight DLB, 7 PDD, 11 Parkinson disease (PD), 15 AD, and 37 normal control (NC) subjects underwent PiB-PET imaging and neuropsychological assessment. Amyloid burden was quantified using the PiB distribution volume ratio.

Results

Cortical amyloid burden was higher in the DLB group than in the PDD group, comparable to the AD group. Amyloid deposition in the PDD group was low, comparable to the PD and NC groups. Relative to global cortical retention, occipital PiB retention was lower in the AD group than in the other groups. For the DLB, PDD, and PD groups, amyloid deposition in the parietal (lateral and precuneus)/posterior cingulate region was related to visuospatial impairment. Striatal PiB retention in the DLB and PDD groups was associated with less impaired motor function.

Conclusions

Global cortical amyloid burden is high in dementia with Lewy bodies (DLB) but low in Parkinson disease dementia. These data suggest that β-amyloid may contribute selectively to the cognitive impairment of DLB and may contribute to the timing of dementia relative to the motor signs of parkinsonism.

Background

MRI studies have demonstrated differential rates of atrophy in the entorhinal cortex and hippocampus during the prodromal phase of Alzheimer disease (AD). The current study was designed to determine whether a broader set of temporoparietal regions show differential rates of atrophy during the evolution of AD.

Methods

Sixteen regions of interest (ROIs) were analyzed on MRI scans obtained at baseline and follow-up in 66 subjects comprising three groups: controls = individuals who were cognitively normal at both baseline and follow-up; nonconverters = subjects with mild cognitive impairment (MCI) at both baseline and follow-up; converters had MCI at baseline but had progressed to AD at follow-up.

Results

Annualized percent change was analyzed with multivariate analysis of variance (MANOVA), covaried for age. The MANOVA demonstrated an effect of group (p = 0.004). Post hoc comparisons demonstrated greater rates of atrophy for converters vs nonconverters for six ROIs: hippocampus, entorhinal cortex, temporal pole, middle temporal gyrus, fusiform gyrus, and inferior temporal gyrus. Converters showed differentially greater rates of atrophy than controls in five of the same ROIs (and inferior parietal lobule). Rates of change in clinical status were correlated with the atrophy rates in these regions. Comparisons between controls and nonconverters demonstrated no differences.

Conclusion

These results demonstrate that temporoparietal regions show differential rates of atrophy on MRI during prodromal Alzheimer disease (AD). MRI data correlate with measures of clinical severity and cognitive decline, suggesting the potential of these regions of interest as antemortem markers of prodromal AD.

Neurofibrillary tangles (NFTs) are the most common intraneuronal inclusion in the brains of patients with neurodegenerative diseases and have been implicated in mediating neuronal death and cognitive deficits. Here, we found that mice expressing a repressible human tau variant developed progressive age-related NFTs, neuronal loss, and behavioral impairments. After the suppression of transgenic tau, memory function recovered, and neuron numbers stabilized, but to our surprise, NFTs continued to accumulate. Thus, NFTs are not sufficient to cause cognitive decline or neuronal death in this model of tauopathy.

Context

Breast cancer estrogen-receptor status is useful in predicting benefit from endocrine therapy. It may also help predict which patients benefit from advances in adjuvant chemotherapy.

Objective

Compare differences in benefits from adjuvant chemotherapy achieved by patients with ER-negative versus ER-positive tumors.

Design

Trial data from the Cancer and Leukemia Group B and U.S. Breast Cancer Intergroup analyzed; patient outcomes by ER status compared using hazards over time and multivariate models.

Setting

Randomized trials comparing (1): three regimens of cyclophosphamide, doxorubicin, and fluorouracil; (2) three doses of doxorubicin concurrent with cyclophosphamide, with/without subsequent paclitaxel; (3) sequential doxorubicin, paclitaxel, and cyclophosphamide with concurrent doxorubicin and cyclophosphamide followed by paclitaxel, and also three-week versus two-week cycles.

Patients

Total of 6644 node-positive breast cancer patients receiving adjuvant treatment.

Main Outcome Measures

Disease-free and overall survival.

Results

For ER-negative tumors, chemotherapy improvements reduced the relative risk of recurrence by 21, 25 and 23 percent in the three studies, respectively, and 55 percent comparing the lowest dose in the first study with biweekly cycles in the third study. Corresponding relative risk reductions for ER-positive tumors treated with tamoxifen were 9, 12, and 8 percent in the three studies, and 26 percent overall. The overall mortality rate reductions associated with chemotherapy improvements were 55 and 23 percent among ER-negative and ER-positive patients, respectively. All individual ER-negative comparisons and no ER-positive comparisons were statistically significant. Absolute benefits due to chemotherapy were greater for patients with ER-negative compared with ER-positive tumors: 22.8 percent more ER-negative patients survived to 5 years disease-free if receiving chemotherapy versus 7.0 percent for ER-positive patients; corresponding improvements for overall survival were 16.7 versus 4.0 percent.

Conclusions

Among patients with node-positive, ER-negative breast cancer, biweekly doxorubicin/cyclophosphamide plus paclitaxel lowers the rate of recurrence and death by more than 50 percent in comparison with low dose CAF as used in the first study.

Evolutionary relationships based on nucleotide variation within the D3 26S rDNA region were examined among acollection of seven Meloidogyne hapla isolates and seven isolates of M. arenaria, M. incognita, and M. javanica. Using D3A and D3B primers, a 350-bp region was PCR amplified from genomic DNA and double-stranded nucleotide sequence obtained. Phylogenetic analyses using three independent clustering methods all provided support for a division between the automictic M. hapla and the apomictic M. arenaria, M. incognita, and M. javanica. A nucleotide sequence character distinguishing M. hapla from the three apomictic species was a 3-bp insertion within the interior of the D3 region. The three apomictic species shared a common D3 haplotype, suggesting a recent branching. Single M. hapla individuals contained two different haplotypes, differentiated by a Sau3AI restriction site polymorphism. Isolates of M. javanica appeared to have only one haplotype, while M. incognita and M. arenaria maintained more than one haplotype in an isolate.

Biochemical and molecular analyses of genetic variation were evaluated to address the taxonomic status of Nacobbus aberrans. Isolates from Mexico, Peru, and Argentina, cultured on tomato in the greenhouse, were analyzed with respect to isozyme and DNA marker variation. Although acid phosphatase and malate dehydrogenase revealed distinct profiles for each isolate, non-specific esterases revealed possible affinities between the Peruvian isolates and between the isolates from Mexico and Peru. Two of l 0 RAPD primers revealed affinities suggested by esterase profiles. RFLP analysis of the rDNA repeating unit with six restriction enzymes revealed identical cleavage patterns between the Peru isolates and a distinct profile shared by isolates from Mexico and Argentina. Nucleotide sequence analysis of the 5.8S rRNA coding region revealed differences among the four isolates at eight of 157 positions; sequences of the Peruvian isolates differed from each other at only one position, whereas the Mexican and Argentine isolates were identical and could be distinguished from the Peruvian isolates. A distance matrix from unweighted pairwise comparisons of the 5.8S rDNA revealed apparent elevated intraspecific divergence in N. aberrans comparable to intergeneric divergence between Heterodera and Globodera. Analysis of additional N. aberrans isolates from throughout the distribution range should help determine the full extent of intraspecific genetic variation that underlies the phenotypic and morphologic diversity of the genus.

Recent advances in molecular biology have enabled the genotyping of individual nematodes, facilitating the analysis of genetic variability within and among plant-pathogenic nematode isolates. This review first describes representative examples of how RFLP, RAPD, AFLP, and DNA sequence analysis have been employed to describe populations of several phytonematodes, including the pinewood, burrowing, root-knot, and cyst nematodes. The second portion of this paper evaluates the utility of a size-variable mitochondrial DNA locus to examine the genetic structure of Meloidogyne isolates using two alternate methodologies, variable number tandem repeat (VNTR) and repeat associated poiymorphism (RAP) analysis. VNTR analysis has revealed genetic variation among individual nematodes, whereas RAP may provide useful markers for species and population differentiation.

Mitochondrial DNA sequences were obtained from the NADH dehydrogenase subunit 3 (ND3), large rRNA, and cytochrome b genes from Meloidogyne incognita and Romanomermis culicivorax. Both species show considerable genetic distance within these same genes when compared with Caenorhabditis elegans or Ascaris suum, two species previously analyzed. Caenorhabditis, Ascaris, and Meloidogyne were selected as representatives of three subclasses in the nematode class Secernentea: Rhabditia, Spiruria, and Diplogasteria, respectively. Romanomermis served as a representative out-group of the class Adenophorea. The divergence between the phytoparasitic lineage (represented by Meloidogyne) and the three other species is so great that virtually every variable position in these genes appears to have accumulated multiple mutations, obscuring the phylogenetic information obtainable from these comparisons. The 39 and 42% amino acid similarity between the M. incognita and C. elegans ND3 and cytochrome b coding sequences, respectively, are approximately the same as those of C. elegans-mouse comparisons for the same genes (26 and 44%). This discovery calls into question the feasibility of employing cloned C. elegans probes as reagents to isolate phytoparasitic nematode genes. The genetic distance between the phytoparasitic nematode lineage and C. elegans markedly contrasts with the 79% amino acid similarity between C. elegans and A. suum for the same sequences. The molecular data suggest that Caenorhabditis and Ascaris belong to the same subclass.

Some reports have suggested that naloxone, a short-acting opiate receptor blocker given intravenously, has a beneficial effect on the symptoms of senile dementia of the Alzheimer type. We have performed a double-blind, crossover trial of naltrexone, an orally active, long acting opiate antagonist, in 17 Alzheimer-type dementia patients. None showed any improvement in assessments of day-to-day living skills or on a battery of neuropsychological tests. No side effects were noted. In the dosage used, naltrexone appears not to be useful in Alzheimer-type dementia.