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PubMed1988

Longitudinal changes in auditory discrimination in normal children and children with language-learning problems.

Two groups of children--one progressing normally in school and the other exhibiting language-learning problems--were tested in each of 3 years on a set of fine-grained auditory discrimination tasks that required listening for small acoustic differences. Children's ages ranged from 6 to 9 years; there were 21 children per group. The children with language-learning problems, despite having normal intelligence and normal pure-tone sensitivity, showed poorer auditory discrimination than normal children for temporally based acoustic differences. This effect continued across the 3 years. Children with language-learning problems also exhibited poorer receptive vocabulary and language performance as well as more deviations from standard Midwest articulation than children making normal progress in school. All children had hearing within the normal range, but at some frequencies there was a significant association of pure-tone sensitivity with performance on the auditory discrimination, receptive language, and speech production tasks.

Auditory Perception↗
PubMed1988

Cross-sectional and longitudinal changes in pulmonary function associated with automobile pollution among bridge and tunnel officers.

This study investigated the effects of emissions from the internal combustion engine on pulmonary function and respiratory symptoms in men collecting tolls and directing traffic in areas with high levels of air pollution. Bridge and tunnel officers (BTOs) were administered pulmonary function tests and respiratory questionnaires for up to 11 consecutive years (n = 944). Carboxyhemoglobin levels were also measured. Regression coefficients on year tested were calculated on 466 individuals (49% of all BTOs) tested at least 3 years. The tunnel workers had significantly lower FEV1S (forced expiratory volume at one second) and FVCs (forced vital capacity), respiratory symptoms, and higher carboxyhemoglobin levels than the bridge workers. BTOs working over 20 years had the lowest mean pulmonary function values, the steepest slopes, and the most respiratory symptoms. We believe that the data show an association between working as a bridge and tunnel officer and decreased pulmonary function and increased respiratory symptoms, but it was not readily evident whether the effects were of clinical importance.

Adult↗
PubMed1982

Longitudinal changes in the maxilla and the maxillary-mandibular relationship between 8 and 17 years of age.

The purpose of this study was to examine the changes in the maxilla and the maxillary-mandibular relationship as they relate to standing height, which is one indicator of skeletal maturation. The subjects for this study consisted of twenty males and fifteen females for whom cephalograms were taken annually between the ages of 8 and 17 years. Descriptive statistics summarized the changes in standing height and the facial parameters from 8 to 17 years of age. Analysis of variance was used to describe the linear and angular changes and also to compare the mean growth profiles of each of the facial parameters to the growth profile for standing height. Autocorrelation analysis was used to assess the predictability of the growth profiles of the facial parameters from the profile of standing height for the same person. Three periods of growth were also compared: premaximum, maximum, and postmaximum. The findings in the present investigation indicated that (1) the growth profile of the absolute and incremental changes in standing height and the various facial parameters were in general significantly different between males and females; (2) the growth profile of standing height was significantly different from the parameters describing maxillary length and relationship as well as maxillary-mandibular relationship; (3) the changes in maxillary length (A-Ptm) were significantly larger in the maximum period of growth than the other two periods of growth for both males and females; (4) the changes in maxillary relationship were significantly different in the maximum period of growth than in the other two periods of growth in males only; (5) the change in maxillary-mandibular relationship was not significantly different in the three periods of growth; (6) autocorrelation analysis revealed that the growth profile of the facial parameters could not be predicted from the growth profile of standing height of the same individual; that is, the growth profile of height was found to have little predictive value in determining the growth profile of any of the other parameters. The present findings as well as those of a previous investigation indicate that treatment of anteroposterior discrepancies should be initiated as soon as the orthodontist believes that treatment is indicated, rather than waiting for the pubertal "spurt," since the presence, magnitude, and timing of such events in any one patient are highly unpredictable, at least to the degree that renders them clinically useful to the orthodontist.

Adolescent↗
PubMed1998

Longitudinal changes in TCRB variable gene expression and markers of gingival inflammation in experimental gingivitis.

The aim of this study was to gain information of the cellular and molecular events which occur during the development of experimental gingivitis and to determine whether such changes occur in the presence or absence of alveolar bone resorption. Clinical, radiographic, biochemical and immunological variables were monitored in a 3-week, single-centre, experimental gingivitis study of 10 healthy volunteers. Following screening and professional prophylaxis to achieve visibly healthy gingival status, subjects abstained from all oral hygiene practises in one maxillary (test) quadrant for a period of 21 days. At days 0 and 21, in test and (contralateral) control quadrants, % bleeding on controlled pressure probing (% BOP) was calculated, and radiographic alveolar bone status was assessed using bilateral standardised vertical bite-wing radiographs and digital subtraction radiography (DSR) analysis. In test quadrants, gingival crevicular fluid (GCF) was sampled from 4 sites per subject with Periopaper strips, and prostaglandin E2 (PGE2) levels measured using an enzyme immunoassay (EIA) kit. At days 0, 7 and 21, one interdental papilla was surgically excised from the test quadrant, and the expression of T cell receptor B variable (TCRBV) genes was investigated using a reverse transcription-polymerase chain reaction (RT-PCR) procedure. At days 0, 7 and 21, peripheral blood lymphocytes (PBL) were isolated and additionally investigated for TCRBV gene expression. Following 21 days of plaque accumulation in test quadrants, a statistically significant increase in % BOP scores confirmed the presence of gingival inflammation (p<0.001). DSR analysis revealed that there were no significant alveolar bone changes in either the test or control quadrants between days 0 and 21 (p>0.05). EIA analysis of GCF samples identified a significant decrease in mean GCF PGE2 concentrations from day 0 to day 21 (p<0.05). RT-PCR analysis indicated that genes from all 3 TCRBV families studied (TCRBV-2, -6, -8) were expressed in the PBL samples at all time points and in healthy gingival tissues at day 0. A restriction in the expression pattern of TCRBV genes similar to those which have previously been reported in chronic periodontitis was noted at gingivitis sites. It is possible that such an event may identify susceptibility to periodontal disease independently of other positive predictive markers such as GCF-PGE2.

Adolescent↗
PubMed1994

Longitudinal changes in serum zinc concentration and distribution after acute myocardial infarction.

The authors studied the changes in serum zinc concentration and distribution during the 15 days following acute myocardial infarction in 21 patients. The method is based on ultrafiltration and electrothermal atomic absorption spectrometry. It is rapid and needs only 2.5 ml of serum. Serum and erythrocyte copper and zinc, serum zinc-binding ligands and serum enzyme activities were also determined. Serum zinc (P < 0.00001) and exchangeable zinc (mainly albumin-bound zinc, P = 0.01) declined within the first 3 days and then returned gradually to reference ranges. Exchangeable zinc was correlated with transthyretin (P = 0.00001) and total serum zinc (P < 0.00001). Exchangeable zinc accounted for virtually all of the differences in total serum zinc concentration after myocardial infarction. This result could be related to an increase of zinc uptake by tissues. Therefore, studies are needed to evaluate whether zinc supplementation in the early stages of acute myocardial infarction might improve prognosis.

Adult↗
PubMed1990

Longitudinal changes in the bone mineral content of term and premature infants.

With the use of photon absorptiometry, bone mineralization was measured at birth and 8 and 16 weeks after delivery in 12 very-low-birth-weight premature (mean +/- SD gestational age, 31 +/- 1.5 weeks) infants who required minimal medical support. Simultaneously, 19 healthy term infants were studied. Throughout the study, each neonate received modified 84-kJ/30 mL formula containing no added calciferol. The recommended daily allowance (400 IU) of calciferol was given to each infant as an oral supplement. Serum 25-hydroxyvitamin D, calcium, phosphorus, and parathyroid hormone concentrations were monitored biweekly and were normal. Bone mineral content and bone width significantly differed at birth between the term and premature infants. However, by 16 weeks after delivery, the premature infants had exceeded the bone mineral status of the term infants at birth, and their bone mineral content was not significantly lower than that of the term infants. These data indicate improved bone mineralization as compared with previously reported data from very-low-birth-weight neonates.

Absorptiometry, Photon↗
PubMed1992

Short-term longitudinal change in cognitive performance in later life.

Changes in mean performance on memory, information processing, and intellectual ability tasks over a 3-year period were examined. The sample consisted of 328 community-dwelling men and women (from an original sample of 484 individuals) aged 55-86 years. Ss completed tasks yielding measures of verbal processing time, working memory, implicit memory, vocabulary, verbal fluency, world knowledge, reading comprehension, word recall, and text recall. The results showed significant average decline on working memory, verbal fluency, and world knowledge. There were also interactions for 2 processing time measures and working memory, showing greater decline in the earlier-born cohort group than in the later-born cohort group. A step-down analysis revealed that covarying declines in other variables, including processing time, did not eliminate significant declines in working memory, verbal fluency, and world knowledge.

Adult↗
PubMed1997

Relationship between inpatient alcoholism treatment and longitudinal changes in health care utilization.

OBJECTIVE: The purpose of the study was to evaluate changes in health care utilization associated with inpatient alcoholism treatment in alcoholics of low socioeconomic status with different histories of treatment relapse. METHOD: The sample consisted of more than 85,000 male alcoholics using inpatient care in Department of Veterans Affairs medical centers in fiscal year 1987. Five treatment groups were identified to represent a continuum of length and intensity of alcoholism treatment, including formal inpatient alcoholism treatment, short detoxification and hospitalizations for primary diagnoses other than alcoholism. All inpatient and outpatient health services for 3 years before and 3 years after the index hospitalization were examined for differential changes in utilization associated with the five treatment groups after controlling for patient predisposing, enabling and need characteristics. RESULTS: Both total inpatient days and outpatient visits increased significantly for all treatment groups, with the greatest increases occurring in the group completing inpatient alcoholism treatment (both p < .0001). However, use of inpatient medical care decreased and substance abuse inpatient care increased significantly for most groups, with the largest increases in substance abuse care found for the completed treatment group. CONCLUSIONS: In a hospital system that does not deny care on the basis of ability to pay, certain groups of chronic alcoholics who cannot sustain prolonged remission will continue to be heavy utilizers of services. Alcoholism treatment may be associated with higher short-term costs but it remains to be seen whether provision of more focused treatment services is able to achieve longer term better outcomes and, ultimately, lower costs.

Adult↗
PubMed1994

Longitudinal changes in injection behaviors in a cohort of injection drug users.

To determine how the injecting behaviors of injection drug users (IDUs) change over time in the context of the epidemic of acquired immunodeficiency syndrome (AIDS) and what factors may be associated with such changes, a cohort of IDUs (n = 313) initially in treatment provided structured interviews regarding drug injecting behaviors. Repeat interviews in 18 months assessed behavior change in subjects who could be contacted for follow-up (n = 220, 70.3%). The study occurred in a state where sterile syringes can be purchased without prescription in drug stores. Injection drug use occurred for 180 (81.8%) of the 220 subjects in the 12 months prior to the initial interview but in only 121 (55.0%) in the 10 months prior to the follow-up interview (p < 0.0001). Similarly, sharing of equipment decreased from 63.1% to 31.8% (p < 0.0001). Sharing with multiple partners declined from 41.9% to 10.6% (p < 0.0001). Factors associated with ongoing risk included use of injected and non-injected psychoactive substances, less time in drug dependence treatment during follow-up interval, having a sexual partner who was an IDU and not using a drug store as the primary source of syringes. Factors associated with multiple-partner sharing included use of psychoactive substances, younger age and nonwhite race.

Cohort Studies↗
PubMed2005

Evaluation of a high-sensitivity turbidimetric immunoassay for serum C-reactive protein: application to the study of longitudinal changes throughout normal pregnancy.

C-Reactive protein has been associated with several complications of pregnancy. The aims of the present study were: (1) to evaluate a turbidimetric immunoassay for the measurement of C-reactive protein; and (2) to investigate the chronological changes of the levels of this protein from preconception throughout normal pregnancy and its relationship with variables associated with preconception and pregnancy outcome. Inter-assay imprecision was <5% for C-reactive protein >1 mg/L and 18% at a mean value of 0.33 mg/L. The limit of detection was 0.10 mg/L. The method was linear between 0.10 and 30 mg/L. There were no observed interferences from jaundice, hemolysis, lipemia or paraproteinemia at the levels studied. There was good agreement with the nephelometric method. A total of 39 women were studied at preconception, at 8, 20 and 32 weeks of pregnancy, and in labor. Preconception C-reactive protein concentration was 1.17+/-0.18 mg/L and increased (p<0.001) throughout pregnancy up to 5.69+/-0.82 mg/L. Body mass index at preconception and weight gain during pregnancy were the main factors associated with this increase in C-reactive protein.

Adolescent↗
PubMed1986

Cigarette smoking initiation and longitudinal changes in serum lipids and lipoproteins in early adulthood: the Bogalusa Heart Study.

To examine the influence of cigarette smoking initiation on serum lipid and lipoprotein changes in early life, 747 nonsmoking 9- to 17-year-olds from the biracial community of Bogalusa, Louisiana were reexamined five to six years following an initial screening. Upon reexamination in 1981-1983, 147 reported smoking cigarettes (mean duration, 3.5 years; median number of weekly cigarettes, 20). Compared with nonsmokers, persons who began smoking had more unfavorable changes in serum triglycerides and lipoprotein cholesterol levels during follow-up, independently of age, sexual maturation, obesity, alcohol consumption, and oral contraceptive use in females. Smoking initiation was not associated with increases in serum total cholesterol levels, but compared with nonsmokers, white males and white females smoking three or more packs weekly showed additional mean increases of 13.2 and 11.6 mg/dl in low density lipoprotein cholesterol, additional 5.9 and 2.4 mg/dl increases in very low density lipoprotein cholesterol (VLDL-C), and additional decreases of 15.6 and 9.2 mg/dl in high density lipoprotein cholesterol levels, respectively. Black smokers showed larger increases in serum triglycerides and VLDL-C levels than did black nonsmokers. These findings indicate that the start of even modest cigarette smoking may have potentially long-term atherogenic effects. Prevention of smoking in early life should therefore be an important aspect of cardiovascular disease intervention.

Adolescent↗
PubMed1996

Longitudinal changes in alcohol and drug use among men seen at a gay-specific substance abuse treatment agency.

OBJECTIVE: This study describes changes over a 12-month period in prevalence and frequency of alcohol and other drug use and correlates of change at 12 months in a sample of gay/bisexual men entering gay-identified outpatient substance abuse treatment. METHOD: A sequential sample of gay/bisexual men (n = 455) were recruited for a study in which substance use, sexual risk and psychological factors were assessed every 3 months. Changes in substance use were evaluated in 321 men who used in the 90 days before entering treatment and who completed at least one follow-up interview, whether or not they continued in treatment. RESULTS: At baseline, 95% of the sample reported alcohol use in the prior 90 days; 64%, marijuana/hashish use; 46%, amphetamine use; 33%, inhalant nitrites use; and 31%, cocaine use. Most men were polydrug users: 10% reported using only one drug (including alcohol); 39% used > or = 4 drugs. A marked reduction occurred in prevalence of use over time; declines on the order of 50% occurred in the first 90 days; prevalence then stabilized in remaining assessments. Frequency of usage by those reporting use of any given class of drugs also declined. No consistent predictors of reduction or cessation of use across different drug categories were found at 1 year. CONCLUSIONS: Substance use declined considerably in this sample. Given the scope of substance abuse problems among gay/bisexual men, and linkages to the HIV epidemic, considerable resources need to be focused on treatment and prevention for gay/bisexual men.

Adult↗
PubMed1991

Longitudinal changes in forearm bone mineral content in primary hyperparathyroidism.

Forearm bone mineral content was measured in 28 patients with primary hyperparathyroidism before and 1 year after successful parathyroidectomy. The forearm bone mineral content rose from a mean value of 1.068 to 1.092 g/cm (P less than 0.05, paired t-test). Those patients with the lower initial values had the largest rise. In an additional study, the forearm bone mineral content was measured in 10 women over the age of 40 years (mean age 58.6 +/- 7.9SD years) with hyperparathyroidism before and for 2 years after successful parathyroidectomy and compared with the forearm bone mineral content measured over 2 years in 12 women (mean age 56.3 +/- 5.5SD years) with continuing hyperparathyroidism and with the forearm bone mineral content of 12 eucalcemic control women (mean age 58.8 +/- 8.2SD years), also measured over 2 years. The parathyroidectomized group gained bone, whereas the ongoing hyperparathyroid group and the eucalcemic control group lost bone. The difference between the parathyroidectomized group and the ongoing hyperparathyroid group was significant after 2 years (P less than 0.05). The percentage loss of forearm bone mineral in the eucalcemic control subjects was not significantly different from the percentage loss of forearm bone mineral in the ongoing hyperparathyroid group, although the initial mean bone mineral content in the eucalcemic group was significantly higher than in the ongoing hyperparathyroid group, suggesting that a possible determinant of bone mineral loss in women in this age group is the initial bone mineral content.

Adult↗
PubMed2000

Intra-individual variability and longitudinal changes in glycaemic control in patients with Type 1 diabetes mellitus.

AIMS: Patients with Type 1 diabetes mellitus (DM) appear to have remarkably stable HbA1c levels, regardless of the need for improvement. The purpose of the present study was therefore to study predictors of intra-individual variability of the HbA1c level together with changes in HbA1c over time. METHODS: Hospital records of patients with Type 1 DM seen at our diabetes clinic from February 1992 to May 1997 were reviewed for HbA1c measurements and clinical data. In the main study, 214 patients who had been on insulin for more than 1 year, and in a sub-study, 14 patients newly started on insulin, were included. RESULTS: The coefficient of variation (CV) of the intra-individual HbA1c measurements, after at least 1 year of insulin, was 8.8 +/- 3.7% (mean +/- SD). There was a positive association between the CV and the HbA1c measurement at inclusion in the study (P < 0.05), and also a negative association between the CV and age (P < 0.05). Fifty per cent of the patients had a difference between first and last HbA1c below 1%, and 83.6% had a difference below 2%. In the sub-study, there was a positive association between the mean HbA1c value the first year on insulin (excluding the first 3 months) and the last HbA1c measurement (P < 0.01). CONCLUSIONS: The HbA1c levels in individual patients remain remarkably stable over time. Furthermore, the HbA1c level shortly after starting insulin is a predictor of future glycaemic control.

Adult↗
PubMed1990

Longitudinal changes in atopy during a 4-year period: relation to bronchial hyperresponsiveness and respiratory symptoms in a population sample of Australian schoolchildren.

A total of 380 schoolchildren living in Belmont, New South Wales, a coastal town where the predominant aeroallergens are house dust mites, were studied on three occasions at 2-year intervals. At each study, atopy was measured by skin prick tests to 13 allergens, bronchial responsiveness was measured by histamine inhalation test, and respiratory illness history was assessed by a self-administered questionnaire to parents. The age of the group was 8 to 10 years at enrollment. We found that skin wheals less than 4 mm were not associated with respiratory or allergic illness, and therefore, we defined atopy as the presence of a skin wheal of greater than or equal to 4 mm. In the sample, 24% of the children were atopic at 8 to 10 years (early-onset atopy), and an additional 15% became atopic during the study (late-onset atopy). Both early- and late-onset atopy had a close association with hay fever. Late-onset atopy was strongly associated with inconsistent reporting of symptoms. Early-onset atopy was an important risk factor for bronchial hyperresponsiveness (BHR), diagnosed asthma, and continuing symptoms of wheeze, and was a particularly important risk factor for BHR with current wheeze in late childhood years. We conclude that atopy acquired at an early age is an important predictive factor for respiratory symptoms occurring with BHR and continuing into late childhood.

Bronchi↗
PubMed1993

Normal values for handgrip strength in 920 men and women aged over 65 years, and longitudinal changes over 4 years in 620 survivors.

1. The maximal grip strength of the hand has been measured in a random sample of 359 men and 561 women aged over 65 years living in their own homes. The response rate was 80% from a representative demographic area of the U.K. Measurements were made of body mass, skeletal size (demispan) and grip strength. Grip strength was measured using a custom-built strain-gauged dynamometer. The best of three attempts was taken as definitive. A structured questionnaire was used to obtain information about customary activity, use of handgrip muscles, health and psychological well-being. This was repeated with 620 survivors 4 years later. 2. The results for strength were normally distributed. The right hand was 10% stronger than the left and men had twice the strength of women. Strength was significantly related to skeletal size and in men to body mass. The gender difference was only partly accounted for by skeletal size and women were substantially disadvantaged in terms of their strength/body mass ratio. 3. There was a significant decline in strength with age of 2%/year for men and women. Strength was also significantly related to customary activity, reported use of the hands and psychological and physical health. 4. After 4 years 620 survivors were re-measured. Grip strength had declined by 12% in men and 19% in women and these losses were significantly related to age. A significant decline was also found in reported use, customary activity and health scores, and in women in body mass and psychological health.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed2002

Longitudinal changes in articulation rate and phonetic phrase length in children with speech delay.

This study examined long-term changes in articulation rate (the pace at which speech segments are produced) and phonetic phrase length in the conversational speech of two groups of children with speech delay (SD) of unknown origin. Initial testing for both groups occurred at preschool age, with follow-up testing conducted for the Early Follow-Up Group (n = 17) at age 9 years and for the Late Follow-Up Group (n = 36) at age 12-16 years. At follow-up testing both groups produced significantly faster articulation rates (measured in both syllables per second and phones per second) and significantly longer phonetic phrases (measured in both syllables and phones) than at initial testing. Articulation rates at both test times were also judged to be similar to published values from typically developing children of similar ages when measured in syllables per second. However, findings for rate in phones per second suggested that at least at initial testing the children were articulating speech at a slower rate than their typically developing peers. This latter finding, however, may have been an artifact of the high frequency of errors--such as cluster reduction and final consonant deletion--observed in the initial samples. It would appear, therefore, that children with SD of unknown origin may start out with slower than normal articulation rates but eventually catch up to their typically developing peers.

Adolescent↗
PubMed1999

Longitudinal changes in sexual risk behavior among HIV+ and HIV- male injecting drug users.

UNLABELLED: Injecting drug users (IDUs) play a prominent role in the transmission of human immunodeficiency virus (HIV), particularly in urban areas such as New York City, where they comprise nearly half of all adult acquired immunodeficiency syndrome (AIDS) cases. Intervention studies have demonstrated that IDUs are responsive to safer sex messages, but sexual behavior appears to be more resistant to change than drug use behavior. This multidisciplinary study (without an intervention component) assesses changes in sexual risk behavior as a function of time, HIV status, and disease progression in a cohort of HIV+ and HIV- male IDUs (N = 144) for 4 years. RESULTS: For HIV+ and HIV- men, there were increases in abstinence and monogamy, with decreases in the frequency of unprotected vaginal/anal sex and sexual risk index scores. With the exception of monogamy, HIV+ men reported lower levels of risk. Although there was also a decline in substance use, this accounted for only some of the decline in sexual risk behavior. Among the HIV+ men, a CD4 level below 200 was associated with more abstinence and monogamy. HIV-related medical symptoms were associated with increased abstinence, less unprotected sex, and lower sexual risk index scores. Lower neuropsychological memory test scores were associated with increased abstinence and lower sexual risk index scores. Neurological impairment and depression were not associated with sexual risk behavior. CONCLUSION: IDU men in New York City have modified their sexual behavior toward safer practices. Lower levels of risk are found among HIV+ men, particularly those with more progressed HIV illness. Nevertheless, a substantial amount of sexual risk behavior remained in this cohort, indicating the continued need for education and intervention.

Adult↗