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PubMed1999

A 1H MRS study of probable Alzheimer's disease and normal aging: implications for longitudinal monitoring of dementia progression.

In order to evaluate the capability of 1H MRS to monitor longitudinal changes in subjects with probable Alzheimer's disease (AD), the temporal stability of the metabolite measures N-acetylaspartate and N-acetylaspartylglutamate (NA), total Creatine (Cr), myo-Inositol (mI), total Choline (Chol), NA/Cr, mI/Cr, Chol/Cr and NA/mI were investigated in a cohort of normal older adults. Only the metabolite measures NA, mI, Cr, NA/Cr, mI/Cr, and NA/mI were found to be stable after a mean interval of 260 days. Relative and absolute metabolite measures from a cohort of patients with probable AD were subsequently compared with data from a sample of normal older adult control subjects, and correlated with mental status and the degree of atrophy in the localized voxel. Concentrations of NA, NA/Cr, and NA/mI were significantly reduced in the AD group with concomitant significant increases in mI and mI/Cr. There were no differences between the two groups in measures of Cr, Chol, or Chol/Cr. Significant correlations between mental status as measured by the Mini-Mental State Examination and NA/mI, mI/Cr and NA were found. These metabolite measures were also significantly correlated with the extent of atrophy (as measured by CSF and GM composition) in the spectroscopy voxel.

Aged↗

PubMed1998

A strategy for identifying biomarkers of aging: further evaluation of hematology and blood chemistry data from a calorie restriction study in rhesus monkeys.

We examined a dataset derived from a battery of hematology and blood chemistry tests to identify candidate biomarkers of aging in a sample of 33 male rhesus monkeys (Macaca mulatta) ranging in age from 4-27 years. About half this sample comprised an experimental group subjected to 30% calorie restriction for six to seven years compared to the control group fed the same nutritionally fortified diet to approximate ad lib levels. Variables that met the following criteria were selected: (1) longitudinal change within the cohorts of control monkeys; (2) cross-sectional correlation with age across the adult lifespan in the control group; (3) stability of individual differences within all groups; and (4) no obvious redundancy with other selected variables. Five variables emerged from this step-wise selection, including the percentage lymphocytes, and serum levels of alkaline phosphatase, albumin, creatinine, and calcium. These variables were then submitted to a principal component analysis, which yielded a single component accounting for about 58% of the total variance. Based on this marked degree of covariance, these candidate biomarkers of aging could be combined into a biological age score (BAS) for the control and experimental groups. When chronological age was regressed onto BAS, the slopes of the control and experimental groups could be compared. Although a trend toward a slower aging rate in calorie-restricted monkeys was apparent, this analysis did not detect a statistically significant difference in the rate of aging between these groups estimated by this index. Despite this result, a logical strategy was confirmed for expanding the search for candidate biomarkers of aging to apply to this and to other studies assessing interventions that purport to affect the rate of aging in long-lived species.

Aging↗

PubMed2000

Design strategies for longitudinal spirometry studies: study duration and measurement frequency.

Measuring the longitudinal change in FEV(1) is useful for assessing the adverse effects of respiratory exposures and pulmonary diseases. Investigators seek to estimate the "true" mean FEV(1) slope (mu(beta)) of an infinite population. The difference between the estimated mean FEV(1) slope (mu(beta)) and the true mean slope, resulting from biological variation and measurement errors, can be minimized by increasing the number of subjects (N), years of follow-up (D), or the frequency of measurements (P). We defined maximum error e(max) such that P[|mu(beta) - mu(beta)| < or = e(max)] = 0.95, and thus e(max) is one-half the width of the 95% confidence interval for mu(beta). We computed the values of e(max) on the basis of actual data obtained from 160 coal miners and working nonminers who had completed 11 spirometry measurements, using recommended equipment and procedures, at 6-mo intervals over 5 yr. Individual 5-yr FEV(1) slopes (Delta FEV(1)) were calculated by linear regression. For a range of values of N, D, and P, tables are provided for e(max), the magnitude of detectable differences in Delta FEV(1) between two groups, and the recommended number of subjects needed in each of two groups to reliably detect the anticipated differences in Delta FEV(1). The tables provide unique guidance for investigators in selecting among various study design options.

Adult↗

PubMed2005

Zinc absorption and kinetics during pregnancy and lactation in Brazilian women.

BACKGROUND: Adjustments in zinc absorption and endogenous excretion maintain zinc homeostasis in nonpregnant adults fed low-zinc diets. The effects on zinc homeostasis of a low zinc intake during pregnancy and lactation have not been described in a longitudinal study. OBJECTIVE: We examined longitudinal changes in fractional zinc absorption (FZA) and zinc kinetics in 10 healthy Brazilian women who habitually consumed a marginal zinc diet ( approximately 9 mg Zn/d). DESIGN: Zinc status was measured at 10-12 (early pregnancy; EP) and 34-36 (late pregnancy; LP) wk of pregnancy and at 7-8 wk after delivery (early lactation; EL). Zinc kinetics and FZA were studied by using stable isotopic tracers. RESULTS: Zinc intake averaged 9 +/- 3 mg/d throughout the study. FZA increased from 29 +/- 6% at EP to 43 +/- 10% at LP and to 39 +/- 13% at EL (P < 0.05). FZA was inversely related to plasma zinc at EL (r = -0.73, P = 0.02) and LP (r = -0.72, P = 0.07). Plasma zinc mass was 23% greater at LP than at EP or EL (P < 0.05). The amount of zinc (mg/d) that fluxed between plasma and the most-rapidly-turning-over extravascular pool was 53% greater at LP than at EP or EL (P < 0.05). The zinc flux between plasma and the less-rapidly-turning-over zinc pool at EL was 27% greater than that at EP or LP, but this difference was not significant. CONCLUSIONS: FZA increased significantly in women with marginal zinc intakes during pregnancy and lactation; the increase was higher in women with low plasma zinc. Plasma zinc was distributed into a different exchangeable pool at LP than at EL.

Adult↗

PubMed2026

Prognostic Value of Blood-Based P-Tau217 Levels for Progression to Cognitive Impairment.

IMPORTANCE: Blood-based biomarkers for Alzheimer disease, particularly plasma phosphorylated tau 217 (p-tau217), accurately reflect early Alzheimer disease brain pathology in cognitively unimpaired individuals, but estimates of absolute risk of progression to cognitive impairment across multiple cohorts are needed. OBJECTIVE: To estimate absolute risk of progression to cognitive impairment and rates of cognitive decline based on plasma p-tau217 across cognitively unimpaired older adults. DESIGN, SETTING, AND PARTICIPANTS: Longitudinal cohort study using harmonized data from 2684 cognitively unimpaired older adults (defined within cohort) across 6 observational and clinical trial cohorts based in North America, Japan, and Australia. The earliest enrollment was in 2004, with most recent follow-up in 2025. EXPOSURE: Baseline plasma p-tau217. MAIN OUTCOMES AND MEASURES: The primary outcome was time to progression to cognitive impairment (mild cognitive impairment, dementia, or 2 consecutive global Clinical Dementia Rating scores ≥0.5). The secondary outcome was longitudinal change on the latent Preclinical Alzheimer Cognitive Composite (PACC; higher values indicate better performance). RESULTS: Among the 2684 participants (median [IQR] age, 69.6 [66.2-74.2] years; 1697 [63%] female), there were 478 events of progression to cognitive impairment over a median follow-up of 5.4 years (maximum follow-up of 13.5 years). Each 1-SD increase in baseline p-tau217 level was associated with an increased risk of progression to cognitive impairment (hazard ratio, 1.38 [95% CI, 1.30-1.46]), and the association remained significant after adjustment, including β-amyloid positron emission tomography scan Centiloids (hazard ratio, 1.32 [95% CI, 1.24-1.41]). Participants with high (1.1-2.4 SD) and very high (>2.5 SD) baseline p-tau217 had 24% (95% CI, 20%-28%) and 38% (95% CI, 33%-43%) absolute risk of progression over 5 years, respectively, and risk was markedly higher over 10 years, although longer-term estimates were constrained by limited data. Elevated p-tau217 was also associated with faster cognitive decline based on change in latent PACC score. Among the overall sample, baseline latent PACC scores ranged from -0.8 to 2.7. The 5-year annualized decline for the very high p-tau217 group was -0.07 latent PACC units/y (95% CI, -0.10 to -0.05), relative to 0.03 units/y (95% CI, 0.02-0.04) in the low p-tau217 group. CONCLUSIONS AND RELEVANCE: In a pooled sample of multiple selected cohorts of cognitively unimpaired older adults, higher plasma p-tau217 levels were consistently associated with increased risk of clinical progression and accelerated cognitive decline. By providing time-specific absolute risk estimates, these findings support the potential of p-tau217 for prognostic model development, with direct implications for future trial design. Further validation in unselected populations is needed to inform individual prognosis and clinical decision-making in cognitively unimpaired individuals.

Aged↗

PubMed2005

Hormone replacement therapy and arterial blood pressure in postmenopausal women with hypertension.

BACKGROUND: Data on the effect of hormone replacement therapy (HRT) on blood pressure (BP) in hypertensive menopausal women are limited. OBJECTIVE: To investigate the association between HRT and longitudinal change in BP in hypertensive menopausal women. PATIENTS AND METHODS: We recruited a total of 161 hypertensive menopausal women (mean age = 52.2 +/- 6.6 years) attending the hypertension clinic in our hospital that requires HRT to attenuate the effect of menopause symptoms. These women were followed for up tp 36 months, being evaluated every 6 months with measurements of their BP, weight and the number of drugs needed to control their BP. We also measured serum cholesterol levels before and after the initiation of HRT. RESULTS: The systolic BP remained unaffected throughout the whole follow-up period, whereas the diastolic BP was slightly reduced at 6, 24 and 36 months. This decrease was accompanied by an increased need for antihypertensive medication throughout the entire follow-up period, while the body weight also increased at 18, 24, and 36 months. No particular differences were noted with respect to ethnicity, history of pre-eclampsia or surgical menopause, before and after the initiation of HRT. Serum cholesterol levels remained unchanged during the evaluation period. Oestrogen-progestogen combination therapy use was associated with a lower diastolic BP and a smaller number of antihypertensive drugs compared to other forms of HRT. CONCLUSION: HRT use does not have an adverse gross effect on BP in hypertensive menopausal women who need it, although there may be an increased need for antihypertensive therapy during the 36-moth follow-up period of our study.

Antihypertensive Agents↗

PubMed2006

Longitudinal associations between dietary protein intake and survival in hemodialysis patients.

BACKGROUND: Decreased dietary protein intake may be associated with increased mortality risk in individuals with kidney failure undergoing maintenance hemodialysis (MHD). We hypothesized that longitudinal changes in dietary protein intake have independent associations with survival in MHD patients. METHODS: The relation between urea kinetic-based normalized protein nitrogen appearance (nPNA) and all-cause and cardiovascular mortality was examined in a 2-year (July 2001 to June 2003) cohort of 53,933 MHD patients from virtually all DaVita dialysis clinics in the United States, using both conventional and time-dependent (repeated-measure) Cox models to estimate death hazard ratios for quarterly averaged nPNA categories controlled for case-mix, comorbidity, dialysis dose (Kt/V), and available markers of malnutrition-inflammation complex syndrome (MICS). RESULTS: The best survival was associated with nPNA between 1.0 and 1.4 g/kg/d, whereas nPNA less than 0.8 or greater than 1.4 g/kg/d was associated with greater mortality in almost all models. Adjustment for MICS mitigated the associations substantially. A decrease in protein intake during the first 6 months in patients with an nPNA in the 0.8- to 1.2-g/kg/d range was associated incrementally with greater death risks in the subsequent 18 months, whereas an increase in nPNA tended to correlate with reduced death risk. CONCLUSION: Low daily protein intake or decrease in its magnitude over time is associated with increased risk for death in MHD patients. Whether the association between time-varying protein intake and survival is causal or a consequence of anorexia secondary to MICS or other factors needs to be explored further in interventional trials.

Aged↗

PubMed2006

A longitudinal study of serum cobalamins and its binding proteins in lactating women.

OBJECTIVE: To examine longitudinal changes in serum cobalamins, transcobalamin (TC) and haptocorrin (HC) during lactation and to investigate the influence of vitamin B12 supplementation on these parameters. DESIGN: A 9-month follow-up study. SUBJECTS AND METHODS: Lactating mothers (N=89) including 23 supplemented with vitamin B12 (1-18 microg/daily), 41 partly supplemented and 25 not supplemented. Blood samples collected 3 weeks (baseline) and 4 and 9 months post-partum were analysed for cobalamins, TC and HC. Both the total concentration and the cobalamin-saturated form (holo) of TC and HC were analysed. RESULTS: No significant differences were observed in serum cobalamins or its binding proteins related to supplementation with vitamin B12 or the duration of lactation. Serum cobalamins remained unchanged from 3 weeks to 9 months post-partum. Total TC (holoTC) (median+/-s.e. pmol/l) decreased between 3 weeks (710+/-23 (85+/-12)) and 9 months (602+/-21 (76+/-11)) (P<0.0001 (P=0.0002)), whereas total HC (holoHC) increased from (422+/-11 (300+/-9)) at 4 months to (455+/-13 (317+/-10)) to 9 months post-partum (P<0.0001 (P<0.0001)). CONCLUSION: We report a decrease in TC and an increase in HC during a 9-month period post-partum. No differences were observed between the vitamin B12-supplemented and the unsupplemented groups. Thus, supplementation with vitamin B12 has no impact on the circulating level of serum cobalamins or its binding proteins in a Danish population of lactating mothers.

Adult↗

PubMed2003

Apolipoprotein E genotype and early Alzheimer's disease: a longitudinal SPECT study.

BACKGROUND AND PURPOSE: To determine the association of the apolipoprotein E (APOE) genotype and longitudinal changes of regional cerebral blood flow (rCBF) in Alzheimer's disease (AD). Previous reports have yielded conflicting results concerning this association. METHODS: A retrospective cohort study was performed. rCBF was noninvasively measured using 99mTc-ethyl cysteinate dimer single-photon emission computed tomography in 23 patients with probable AD at the very early stage and at a mean interval of 24 months, as well as in 55 age-matched healthy volunteers. Patients were classified into 2 groups according to the presence of the epsilon 4 allele: 11 epsilon 4 carriers and 12 noncarriers. Correction for partial volume effects (PVEs) was performed in all patients using gray matter volume measured by magnetic resonance imaging. Statistical parametric mapping was used for the analysis of absolute rCBF data and the adjusted rCBF images of relative flow distribution. RESULTS: In the baseline study, both carriers and noncarriers showed significant decreases of absolute and adjusted rCBF in the psoterior cingulate gyri and precunei. After PVE correction, carriers showed a greater spread of areas with significant rCBF reduction from the parietotemporal to the frontal area than noncarriers during the follow-up period compared to healthy volunteers. Moreover, carriers showed a significant decline of absolute rCBF in the frontal cortex from the baseline to the follow-up study. CONCLUSIONS: The authors' study suggests that the APOE epsilon 4 allele is associated with the faster progression of AD, and PVE correction may be necessary for accurate assessments of SPECT studies of AD.

Aged↗

PubMed2006

[Longitudinal analysis of age at onset and initial symptoms in patients with amyotrophic lateral sclerosis].

To investigate the longitudinal changes in age at onset and the initial symptom of patients with sporadic amyotrophic lateral sclerosis (ALS), we performed a single hospital-based retrospective study over the past 38 years. A total of 280 sporadic ALS patients (169 men and 111 women) hospitalized in our department between 1965 and 2003 were investigated in this study. The clinical features including age at onset and the initial symptom of these patients were obtained from medical records. All the patients underwent an intensive diagnostic evaluation including electrophysiological examination, laboratory examinations of blood and cerebrospinal fluid, and neuroimagings of the brain and spinal cord to exclude other conditions similar to ALS. The mean age at onset was 58.3 +/- 11.3 years and age at onset significantly increased at the rate of 0.459 years per year (r = 0.406, p< 0.001). The percentage of patients whose age at onset was > or = 70 years has increased from 3.0% (1980-1984) to 31.1% (2000-2003). To investigate the initial symptom of senile-onset ALS, patients whose age at onset was > or = 70 years were analyzed. The percentages of bulbar palsy-onset patients with onset in terms of age were 62.5% (30/48 patients; > or = 70 years) and 23.3% (54/232 patients; <70 years). The odd ratio for bulbar palsy was 5.40 (95% confidence interval, 2.79-10.44). Taken together, our study demonstrates that the ratio of senile-onset ALS has significantly increased, and that there were more bulbar palsy-onset patients among the patients.

Adult↗

PubMed1999

Temporal association between obesity and hyperinsulinemia in children, adolescents, and young adults: the Bogalusa Heart Study.

Obesity is generally associated with hyperinsulinemia. However, whether obesity precedes or follows hyperinsulinemia is not clear. The present study examined the temporal nature of the association between obesity and hyperinsulinemia in a biracial (black-white) community-based population enrolled in the Bogalusa Heart Study. Three longitudinal cohorts of children (n = 427; baseline age, 5 to 7 years), adolescents (n = 674; baseline age, 12 to 14 years), and young adults (n = 396; baseline age, 20 to 24 years) were selected retrospectively, with a follow-up period of approximately 3 years. In general, longitudinal changes in the mean body mass index (kilograms per meter squared), an indicator of adiposity, and fasting insulin level did not parallel each other. In a bivariate analysis, baseline insulin levels correlated significantly with the follow-up body mass index in adolescents and adults, but not in children. On the other hand, the baseline body mass index correlated significantly with follow-up insulin levels in all cases. Logistic regression analysis showed that the proportion of subjects who developed obesity (body mass index > 75th percentile, specific for age, race, gender, and survey year) at follow-up study increased significantly across baseline quintiles (specific for age, race, gender, and survey year) of insulin only among adolescents, irrespective of race and gender. This relationship disappeared after adjusting for the baseline body mass index. By contrast, a significant positive trend between baseline quintiles of the body mass index and incidence of hyperinsulinemia (> 75th percentile) at follow-up study was noted among all age groups independent of race, gender, and baseline insulin levels. Further, in a multiple stepwise regression model, the best predictor of the follow-up insulin level was the baseline body mass index in children and adults and the baseline insulin in adolescents. The baseline body mass index was the best predictor of the follow-up body mass index in all three age groups. These results, by showing the temporal nature of the relation between obesity and hyperinsulinemia beginning in childhood, support the role of obesity in the development of hyperinsulinemia.

Adolescent↗

PubMed2005

Bone mineral density and calcium metabolism of Hong Kong Chinese postpartum women--a 1-y longitudinal study.

OBJECTIVE: This paper reports longitudinal changes in bone mineral density (BMD), calcium homeostasis and dietary calcium intake in a group of Hong Kong breastfeeding women during the first year postpartum. DESIGN AND SUBJECTS: Nine mothers who breastfed exclusively or almost exclusively for at least 3 months and 14 formula feeding mothers aged 20-40 y were interviewed after delivery, 2 and 6 weeks, 3, 6 and 12 months postpartum. BMD at L2-L4 lumbar spine (LS), trochanter (Tro) and femoral neck (FN), serum intact parathyroid hormone (iPTH), serum bone-specific alkaline phosphatase (b-ALP), urinary deoxypyridinoline (Dpd), serum and urinary calcium (Ca) and phosphorus (P) and dietary intake of macronutrients were assessed. RESULTS: Compared to the formula feeding group, BMD assessed at LS, Tro and FN decreased significantly in the breastfeeding group over the first 6 months, with rebound to approximate baseline values at 12 months for the latter two sites. Serum iPTH increased in both groups, whereas serum b-ALP was consistently higher in the breastfeeders. Urinary Ca and P excretion decreased early postpartum in both groups, but the breastfeeders had higher excretion at 3 and 6 months. Breastfeeding mothers consumed significantly more Ca than the formula feeding mothers in the early postpartum. CONCLUSIONS: Increased calcium requirement during early lactation is affected through mobilisation of bone and renal calcium conservation. Bone mineral loss during lactation is temporary. Further studies are warranted to investigate the effects of diet and other hormonal factors on the calcium homeostasis during lactation.

Adult↗

PubMed2002

A longitudinal study of visual acuity and visual rehabilitation needs in an urban Swedish population followed from the ages of 70 to 97 years of age.

PURPOSE: To investigate the longitudinal change in visual acuity (VA) in the oldest members of the elderly population, to estimate future numbers of people with visual impairments, and to estimate needs for and the effects of visual rehabilitation. METHODS: In the Gerontological and Geriatric Population Studies in Gothenburg, Sweden (H 70), subjects underwent repeated eye examinations at the ages of 70, 82, 88, 95 and 97 years. Logistic regression analysis was used to estimate the probability of independent living as a function of distance VA at different ages. RESULTS: Rates of normal VA (>or= 0.8) declined from 86% of the study group at age 70 to 7% of the study group at age 95 (0% at age 97). The incidence of VA <or= 0.1 increased from 1.4% at age 70 to 27% (all women) at age 97. The deterioration was faster at higher ages. No statistically significant difference in best-corrected distance VA between genders was found. A substantial improvement was achieved by correcting refractive errors. There was a statistically significant correlation between distance VA and the probability of independent living at all ages except age 97. At ages 95 and 97, about 50% of the study group were able to read newspaper print with best-corrected glasses. CONCLUSIONS: The number of old people with impaired vision will increase. People aged 80 years and older should have regular eye-screening in order to preserve vision and present conditions of living. Cataract surgery and low vision rehabilitation should be offered when the subject can still benefit from it, preferably during their 80s at the latest.

Activities of Daily Living↗

PubMed1998

Longitudinal lipid profiles on CAPD: their relationship to weight gain, comorbidity, and dialysis factors.

The dyslipidemia of chronic renal failure may worsen after the commencement of continuous ambulatory peritoneal dialysis (CAPD). The purpose of this study was to relate baseline and longitudinal changes in the lipid profile to anthropometrics (weight, mid-arm circumference), aspects of treatment (albumin, total protein losses, peritoneal solute transport [dialysate:plasma ratio of creatinine], dialysate caloric load), total calorie intake (cal/kg), preexisting cardiovascular comorbidity, and survival. Lipid profiles (triglycerides [TG], total cholesterol [TC], and HDL) were measured, along with the above factors, every 6 mo in an unselected prospective cohort of 124 patients who were not treated with lipid-lowering drugs, commencing CAPD between 1990 and 1993, until 1995. On univariate analysis, age, plasma albumin, cardiovascular disease, baseline TG, and TC:HDL ratio predicted survival. Simultaneous multiple Cox regression including all of the significant predictors demonstrated that either high TG or TC: HDL still predicted death, both in patients with and without clinically overt cardiovascular disease. Between 6 and 36 mo of treatment, TC, TG, and TC:HDL were elevated when compared with the baseline, more so in patients with preexisting cardiovascular disease (P < 0.05). Throughout this period, weight and mid-arm circumference correlated positively with TG and negatively with HDL. There were positive correlations between TC and albumin levels for 12 mo after commencement of treatment, but otherwise there were no significant or consistent relationships between lipid profiles and total protein losses, dialysate calorie load, or total cal/kg or solute transport. The worsening dyslipidemia associated with CAPD was not associated with aspects of treatment such as glucose load or protein losses. The strongest predictors of worsening lipid profiles were weight gain and preexisting cardiovascular comorbidity.

Adult↗

PubMed1999

[Longitudinal evaluation of early dementia of Alzheimer type using brain perfusion SPECT].

Regional cerebral blood flow (rCBF) measurements using a Patlak plot method of 99mTc-ECD were performed in early dementia of Alzheimer type (DAT) with both HDS-R and MMSE of over 20 to investigate initial abnormality and longitudinal changes of rCBF. A fusion technique of MRI and SPECT images was developed for MRI-guided analysis of regions of interest in hippocampal areas and statistical parametric mapping (SPM) was used for automated and objective approach to analysis of SPECT image data. Seventeen patients with clinically diagnosed early DAT and age-matched 32 normal control subjects were studied. At the first SPECT studies, the mean cerebral blood flow (mCBF) of 38.6 +/- 4.7 ml/100 g/min (mean +/- SD) for early DAT did not show significant reduction as compared with the normal control value of 42.0 +/- 3.8, whereas the rCBF values in the bilateral hippocampi (right; 26.8 +/- 4.7, left; 26.7 +/- 5.2) showed significant reduction (p < 0.05) as compared with the normal control values (right; 38.3 +/- 4.2, left; 38.4 +/- 3.8). The SPM analysis (voxel height; p < 0.001, Bonferroni correction; p < 0.05) of the first SPECT images revealed significant selective decrease of relative rCBF in the bilateral posterior cingulate gyri. At the second SPECT studies after 1.4 year on the average from the first studies, mCBF for early DAT showed a slight decrease by 1.7 +/- 3.8 ml/100 g/min/year. Bilateral hippocampi showed a greater decrease with slight left-side dominance by 3.8 +/- 3.3 on the right and 4.4 +/- 3.2 on the left side. The SPM analysis demonstrated significant decrease of relative rCBF in the basal fore-brain area, the left hippocampus, the left amygdala, and the left parahippocampal area. These results suggest that the MRI-guided ROI analysis of rCBF values in the hippocampus and the SPM analysis of SPECT images are quite useful for early diagnosis and follow-up of DAT.

Aged↗

PubMed1999

Time trends in systemic adjuvant treatment for node-negative breast cancer.

PURPOSE: We conducted a population-based study in Quebec, Canada, to assess longitudinal changes in systemic adjuvant therapy for node-negative breast cancer. MATERIALS AND METHODS: A stratified random sample was selected among women with newly diagnosed node-negative breast cancer in 1988, 1991, and 1993. Information on the patient, her tumor, source of care, and treatment was abstracted from medical charts. Patients were classified as being at minimal, moderate, or high risk of recurrence on the basis of criteria proposed at the 4th International Conference on Adjuvant Therapy of Primary Breast Cancer (St. Gallen, Switzerland, 1992), and systemic adjuvant treatment received was dichotomized as being consistent or not consistent with consensus recommendations. RESULTS: Overall, 1,578 cases of invasive breast carcinoma were reviewed. The proportion of patients who were given hormonal or cytotoxic treatment increased from 51.7% to 73.1% from 1988 to 1993. Virtually all women at minimal risk were treated in 1991 and 1993 according to the consensus statement. The proportions of women so treated were 75.0% and 65.4% in the moderate- and high-risk categories, respectively, in 1991. In 1993, these proportions were 71.4% and 67.0%, respectively. Omission of chemotherapy, especially in high-risk women with estrogen receptor-negative tumors who were 50 to 69 years of age, was the most frequent inconsistency with guidelines. CONCLUSION: Systemic adjuvant therapy for node-negative breast cancer has gained acceptance. Better understanding of the decision-making process, of the perception of the risks and benefits involved, and of the impact of alternative strategies for the dissemination of consensus recommendations are needed to promote the use of chemotherapy in specific categories of women who are at high risk of recurrence.

Aged↗

PubMed1996

Longitudinal serum HIV RNA quantification: correlation to viral phenotype at seroconversion and clinical outcome.

OBJECTIVE: To investigate the longitudinal changes in serum HIV RNA, and to clarify whether the viral load early in infection has a predictive value for the clinical outcome; also, to correlate viral phenotype at seroconversion and changes in CD4 cell counts with viral burden. DESIGN: Twenty seroconverters with HIV isolates available at seroconversion had HIV RNA quantified by polymerase chain reaction (PCR) at seroconversion and thereafter every 6 months. Mean follow-up time was 65 months. Patients were classified according to viral phenotype at seroconversion, time to AIDS progression, serum viral load within the first year (less or more than 1.5 x 10(4) copies/ml). RESULTS: High viral load at seroconversion was followed by a significant decline within the first months (P < 0.0005). Decline to < 1.5 x 10(4) copies/ml was correlated with slower progression to AIDS (P < 0.05). A correlation between the rate of CD4 decline and the median viral load during the ensuing viral load plateau phase was also shown (P < 0.05). Subsequent to this phase the viral burden increased. Rapid progressors had higher viral load than slow- or non-progressors; this was particularly pronounced late in infection. Harbouring syncytium-inducing (SI) virus at seroconversion was associated with faster progression to AIDS than non-SI (NSI; P < 0.005). The increased in vitro replication rate of SI over NSI was not translated into significantly higher serum HIV RNA. CONCLUSION: Serum HIV RNA is high around the time of seroconversion. A significant decline within the first months hereafter is followed by a plateau phase, which in turn is followed by an increase in HIV RNA. HIV RNA early in infection has a predictive value for the clinical outcome. The increased virulence of SI over NSI virus did not translate into significantly higher HIV RNA values.

Acquired Immunodeficiency Syndrome↗

PubMed2001

A longitudinal study of quantitative uterine blood flow with the use of color power angiography in appropriate for gestational age pregnancies.

OBJECTIVE: The purpose of this study was to examine longitudinally changes in quantified blood volume flow in the uterine arteries during pregnancy with the use of color power angiography. STUDY DESIGN: Color power angiography was used to quantify volume flow in the uterine arteries of 57 women with singleton uncomplicated pregnancies between 20 and 38 weeks' gestation. Comparisons were made between blood flow in the 2 arteries in relation to the location of the placenta. Linear regression models were used to estimate gestational age derived volumetric changes in these vessels. RESULTS: The diameter of the uterine arteries increased from 2.6 mm (SD, 0.2 mm) at 20 weeks to 4.8 mm (SD, 0.7 mm) at 38 weeks of gestation. The total uterine artery blood volume flow increased from 513 mL/min (SD, 127 mL/min) at 20 weeks to 970 mL/min (SD, 193 mL/min) at 38 weeks. The rate of increase was maximum between 20 and 24 weeks (39 mL/min per week). The laterality of the placenta significantly affected the diameter and blood volume flow in each uterine artery. The diameters on the ipsilateral side were significantly greater (by 10.8% +/- 2.4%) than the diameters on the contralateral side at all gestations (P < .05). Similarly, blood volume flow was significantly greater (by 17.8% +/- 2.2%) on the ipsilateral side at all gestations (P < .05). There were, however, no statistically significant differences between the vessel diameters and blood volume flow in those cases in which the placenta was central. Total uterine artery volume flow per kilogram of estimated fetal weight decreased from 1544 mL/kg per minute at 20 weeks to 296 mL/kg per minute at 38 weeks of gestation. CONCLUSION: Total quantified uterine artery blood volume flow increases while blood flow per kilogram of fetal weight decreases with gestation. Blood volume flow in the ipsilateral artery to the placenta was significantly higher than that in the contralateral artery. Calculating total uterine artery volume flow by doubling the blood flow from 1 artery (as was previously done) may therefore either result in an over or underestimation, depending on the relationship between the vessel and the laterality of the placenta. Color power angiography is a simple noninvasive tool for determining uterine artery blood volume flow.

Angiography↗