Biomedical subjects

L Singer

Publications and source records attributed to L Singer.

At least 19 recordsLinked to original sources

PubMed2006

Quality of life improvement after hospital- based rehabilitation or home-based physical training in intermittent claudication.

BACKGROUND: The magnitude of potential changes in Quality-of-Life (QoL) after structured institution-based or home-based peripheral arterial disease (PAD) rehabilitation programs are largely unknown at present. This pilot study provides first QoL data after PAD rehabilitation or a home-based PAD training. PATIENTS AND METHODS: In a non-randomized, open-label pilot study three groups of out-patients were compared: group 1 (n = 18) PAD rehabilitation; group 2 (n = 17) PAD rehabilitation + clopidogrel 75 mg once daily; group 3 (n = 20) home-based training. The training period was 3 months, which was followed by a 3-month observation phase (without prescribed training). The institution-based rehabilitation program consisted of 3 training hours per week whereas patients training at home were instructed to walk for 1 hour per day on an outdoor track. QoL assessment was performed using MOS SF-36, PAVK-86 and PAD-WIQ questionnaires. RESULTS: At baseline background variables, demographics and claudication distances were comparable between groups. After three months of training the percentage changes for the initial and the absolute claudication distance (ICD, ACD) for groups 1, 2, and 3 amounted to 164%, 201%, 44% (ICD) and 83%, 131%, 5% (ACD), respectively. Statistically significant QoL improvements were recorded for physical functions, pain and disease related anxiety in all three study groups; statistically significant inter-group differences were not found. CONCLUSIONS: In sharp contrast to the development of the claudication distances the improvement in QoL, found after 3 months of training, was comparable and not consistently different between the groups.

Aged↗

PubMed2001

Heart rate variability in cocaine-exposed newborn infants.

BACKGROUND: Infants born to cocaine-using mothers have a 3- to 8-fold increase in sudden infant death syndrome. Its underlying cause, in part, may be attributed to abnormal autonomic function. We proposed to study heart rate variability, reflecting autonomic control of the heart, in cocaine-exposed infants. METHODS: From 1997 to 2000, we studied 217 asymptomatic, term infants, of whom 68 had intrauterine cocaine exposure (group I). Their data were compared with infants exposed to drugs other than cocaine (group II, n = 77) and no drugs (group III, n = 72). Twenty-four-hour heart rate variability was measured within 72 hours of birth. RESULTS: Cocaine-exposed infants, as compared with the 2 control groups, had an overall significant decrease (P <.05) in global heart rate variability and a lower standard deviation of all valid N-N intervals in the recording (41.9 +/- 1.4 ms vs 47.6 +/- 1.3 ms and 46.9 +/- 1.3 ms, respectively). Vagal parameters such as high-frequency power and the square root of the mean of the squared differences between adjacent N-N intervals were also lower in newborns with heavy in utero cocaine exposure. CONCLUSIONS: Decreased heart rate variability was seen in cocaine-exposed infants. Whether low heart rate variability is a marker for increased risk of sudden death in infants (as it is in adults with structural heart disease) is unknown and requires further investigation.

Cocaine↗

PubMed2001

Growth and development in preterm infants fed long-chain polyunsaturated fatty acids: a prospective, randomized controlled trial.

OBJECTIVES: A randomized, masked, controlled trial was conducted to assess effects of supplementing premature infant formulas with oils containing the long-chain polyunsaturated fatty acids, arachidonic acid (AA; 20:4 n6), and docosahexaenoic acid (DHA; 22:6 n3) on growth, visual acuity, and multiple indices of development. METHODS: Infants (N = 470) with birth weights 750 to 1800 g were assigned within 72 hours of the first enteral feeding to 1 of 3 formula groups with or without long-chain polyunsaturated fatty acids: 1) control (N = 144), 2) AA+DHA from fish/fungal oil (N = 140), and 3) AA+DHA from egg-derived triglyceride (egg-TG)/fish oil (N = 143). Infants were fed human milk and/or Similac Special Care with or without 0.42% AA and 0.26% DHA to term corrected age (CA), then fed human milk or NeoSure with or without 0.42% AA and 0.16% DHA to 12 months' CA. Infants fed exclusively human milk to term CA (EHM-T; N = 43) served as a reference. RESULTS: Visual acuity measured by acuity cards at 2, 4, and 6 months' CA was not different among groups. Visual acuity measured by swept-parameter visual-evoked potentials in a subgroup from 3 sites (45 control, 50 AA+DHA [fish/fungal]; 39 AA+DHA [egg-TG/fish]; and 23 EHM-T) was better in both the AA+DHA (fish/fungal; least square [LS] means [cycle/degree] +/- standard error [SE; octaves] 11.4 +/- 0.1) and AA+DHA (egg-TG/fish; 12.5 +/- 0.1) than control (8.4 +/- 0.1) and closer to that of the EHM-T group (16.0 +/- 0.2) at 6 months' CA. Visual acuity improved from 4 to 6 months' CA in all but the control group. Scores on the Fagan test of novelty preference were greater in AA+DHA (egg-TG/fish; LS means +/- SE, 59.4 +/- 7.7) than AA+DHA (fish/fungal; 57.0 +/- 7.5) and control (57.5 +/- 7.4) at 6 months' CA, but not at 9 months' CA. There were no differences in the Bayley Mental Development Index at 12 months' CA. However, the Bayley motor development index was higher for AA+DHA (fish/fungal; LS means +/- SE, 90.6 +/- 4.4) than control (81.8 +/- 4.3) for infants </=1250 g. When Spanish-speaking infants and twins were excluded from the analyses, the MacArthur Communicative Development Inventory revealed that control infants (LS means +/- SE, 94.1 +/- 2.9) had lower vocabulary comprehension at 14 months' CA than AA+DHA (fish/fungal) infants (100.6 +/- 2.9) or AA+DHA (egg-TG/fish) infants (102.2 +/- 2.8). There were no consistent differences in weight, length, head circumference, or anthropometric gains. CONCLUSION: These results showed a benefit of supplementing formulas for premature infants with AA and DHA from either a fish/fungal or an egg-TG/fish source from the time of first enteral feeding to 12 months' CA.

Apgar Score↗

PubMed2001

Effect of pneumoperitoneal pressure on tumor dissemination and tumor recurrence at port-site and midline incisions.

Over the past several years numerous cases of port site tumor recurrence after laparoscopic resection of a cancerous tissue have been reported. Possible mechanisms for tumor seeding include tumor removal, contaminated instruments, pneumoperitoneum, and aerosolization of tumor cells. This experiment examined the relationship among trocar contamination, aerosolization, and tumor recurrence with increasing pneumoperitoneal pressure using a hamster model. Increased pneumoperitoneal pressure significantly increased both instrument contamination and tumor recurrence at midline and port site incisions. Interestingly, increasing pneumoperitoneal pressure had no significant effect on the number of aerosolized tumor cells. The results reaffirm that the use of a reduced pneumoperitoneum or gasless laparoscopy may significantly lower port site tumor recurrence.

Animals↗

PubMed2000

Effect of topiramate on body weight and body composition of osborne-mendel rats fed a high-fat diet: alterations in hormones, neuropeptide, and uncoupling-protein mRNAs.

The effects of topiramate on food intake and body composition were investigated in rats fed a high-fat diet and compared with rats that were pair fed or treated with D-fenfluramine. Topiramate (40 mg. kg. d for 80 d) reduced body-weight gain in a manner similar to that of pair-fed rats and D-fenfluramine-treated rats. The reduction in body fat accounted for all the weight reduction after topiramate treatment but not after pair feeding or D-fenfluramine treatment. Topiramate reduced food intake acutely and increased metabolic rate. There were also significant reductions in leptin, insulin, and corticosterone. In the hypothalamus, topiramate increased mRNA for neuropeptide Y, reduced mRNA for neuropeptide-Y Y1 and Y5 receptors, corticotropin-releasing hormone (CRH), and type II glucocorticoid receptors but had no effect on mRNA levels for the short or long form of the leptin receptor. In peripheral tissues, topiramate reduced leptin mRNA in adipose tissue, had no effect on uncoupling protein 1 mRNA in brown adipose tissue but had tissue-selective effects on uncoupling proteins 2 and 3 mRNA levels in white and brown adipose tissues and muscle. In conclusion, topiramate is an effective inhibitor of weight gain in rats on a high-fat diet, but the mechanism through which the change in energy balance is achieved is unclear.

Animals↗

PubMed2000

Effectiveness and cost-benefit of enhancements to a syphilis screening and treatment program at a county jail.

BACKGROUND: High rates of syphilis are found in inmates of county jails. Treatment of this infected transient population necessitated the development of a rapid protocol. GOAL: To evaluate a rapid screening and treatment protocol for syphilis in a county jail. STUDY DESIGN: Over a 2-year period 18,442 inmates were screened for syphilis with a nontreponemal test and record search for treatment history. Confirmatory test results were reviewed following treatment. Cost was defined as deflated marginal outlays. Benefit was calculated as the discounted expected cost of treatment of congenital, late, and neurosyphilis. RESULTS: The sensitivity, specificity, and positive predictive value of the protocol were 99.6%, 80.8%, and 79.3%, respectively. Of 257 confirmed cases, 183 were offered treatment in jail. The percentage of short-term inmates treated increased following implementation. The cost-benefit ratio was 9.14:1. CONCLUSIONS: The protocol was highly effective in patient identification and treatment delivery, and cost-effective as well.

Cost-Benefit Analysis↗

PubMed2000

Dendritic cells and macrophages in lung allografts: A role in chronic rejection?

Antigen presentation by lung macrophages/dendritic cells (DC) is thought to be important in obliterative bronchiolitis/bronchiolitis obliterans syndrome (OB/BOS), which severely limits survival post-lung transplantation. However, a recent study found minimal numbers of DC in lung allografts. We looked at numbers and phenotype of macrophages/DC in lung allografts using endobronchial biopsy (EBB) and transbronchial biopsy (TBB) from 22 lung transplant patients. Biopsies were stained with monoclonal markers of DC (CD1a, RFD1, and major histocompatibility complex [MHC] Class II), and "suppressor macrophages" (RFD1 and RFD7). Dendritic cells were also stained for the costimulatory molecules CD80 and CD86. Significantly greater numbers of DC/high-power field (HPF) were seen in biopsies when we defined DC using dendritic morphology and Class II MHC expression instead of CD1a expression. Dendritic cell numbers were significantly higher in eight patients with OB/BOS compared with 14 stable patients. Fifty percent of DC expressed CD86 and 20% expressed CD80. There was no difference in CD80 or CD86 expression between OB/BOS patients and stable patients. There was no correlation between DC numbers and presence or absence of acute rejection (AR), and/or cytomegalovirus (CMV) pneumonitis on current or prior biopsies. There were significantly more MHC Class II DC in EBB compared with TBB. We found minimal staining for lung macrophages capable of suppressing T-cell inflammation. We conclude that studies of lung allografts may underestimate DC numbers if relying on CD1a as the sole marker of DC. DC are increased in patients with OB/BOS compared with stable patients. EBB may be more important than TBB in looking for inflammatory changes of OB. DC expressing costimulatory molecules are present in lung allografts, and costimulatory pathway blockade may be useful in human lung allografts. Also, the absence of "suppressor" macrophages may increase susceptibility of human lung allografts to the rejection process.

Adult↗

PubMed1999

Motor development of cocaine-exposed children at age two years.

OBJECTIVE: This article was designed to investigate effects of prenatal cocaine exposure on motor development of young children from a predominately underprivileged, urban population. METHODOLOGY: A total of 260 infants and young children were initially recruited from either the newborn nursery or the at-risk pediatric clinic of an urban teaching hospital. Prenatal history and birth outcomes were collected from medical records. Demographic characteristics and additional drug histories were obtained from the mothers. The 199 subjects (98 cocaine-exposed and 101 unexposed) who returned at age 2 years were assessed by examiners blinded to drug exposure status using the Peabody Developmental Motor Scales. RESULTS: Compared with control subjects, the cocaine-exposed group performed significantly less well on both the fine and the gross motor development indices. Mean scores for both groups were within the average range on the gross motor index, but greater than 1 standard deviation below average on the fine motor index. Differences were significant on the balance and the receipt and propulsion subscales of the gross motor scale, and on the hand use and the eye-hand coordination subscales of the fine motor scale. Cocaine status independently predicted poorer hand use and eye-hand coordination scores. There also was an effect of alcohol exposure on the receipt and propulsion subscale. CONCLUSIONS: Findings indicate that deficiencies in motor development remain detectable at 2 years of age in children exposed to drugs prenatally. Although other environmental variables may influence motor development, children exposed to cocaine and to alcohol in utero may encounter developmental challenges that impede later achievement.

Case-Control Studies↗

PubMed1998

Prevalence and correlates of obesity in preschool children.

Obesity, a common nutritional disorder in childhood, is a complex problem that is poorly understood. The purpose of this study was to identify the prevalence of obesity in preschool children, and to examine the relationships between obesity and gender, race, socioeconomic status, and health problems. Data were collected from 309 charts of children enrolled in a Head Start program. Ninety-nine (32%) of the children were obese. Obese children had significantly higher blood pressure readings than those who were not obese. This study represents a beginning effort to learn more about the prevalence of, and factors associated with, obesity in preschoolers.

Age Distribution↗

PubMed1997

Relationship of prenatal cocaine exposure and maternal postpartum psychological distress to child developmental outcome.

Maternal cocaine use during pregnancy can affect the infant directly through toxic effects or indirectly through cocaine's influence on maternal psychological status. We followed 160 cocaine exposed and 56 nonexposed infants and their mothers identified at birth through interview and/or urine screen. Although cocaine exposure defined the groups, infant exposure to alcohol, marijuana, and tobacco was allowed to vary. Infants were 99% African American and poor. All mothers completed the Brief Symptom Inventory (BSI) and infants were given the Bayley Scales of Mental (MDI) and Motor (PDI) Development at a mean corrected age of 17 +/- 8 months. Both MDIs (94 +/- 17 vs. 103 +/- 16) and PDIs (101 +/- 16 vs. 108 +/- 12) were lower for cocaine exposed infants. Psychological distress was greater in cocaine using mothers. Hierarchical multiple regression was used to assess the relative effects of gestational age, maternal psychological distress, and cocaine and polydrug exposure on infant outcomes. Both psychological distress and cocaine and alcohol exposure predicted lower MDIs after controlling for prematurity. Neither psychological distress nor alcohol exposure predicted motor outcome, while cocaine had a significant effect. Tobacco and marijuana exposure were unrelated to outcome. These findings provide further support for direct effects of cocaine and alcohol on infant development as well as highlight the need for studies to document maternal psychological factors, which may increase child risk for poorer outcomes.

Adult↗

PubMed1997

Potential problems associated with use of speech recognition products.

Commercial speech recognition products are being used increasingly as alternate input devices for computers, particularly by persons with physical disabilities. These discrete speech dictation systems require the user to insert brief but distinct pauses after each spoken word. Anecdotal evidence suggests that some persons using these products experience moderate to severe problems with their voices, such as hoarseness, sore throats, and even complete loss of voice. This preliminary study, which includes data gathered from survey dissemination and clinical studies, indicates that persons with cumulative trauma disorder may be the most susceptible to these voice problems. Also, we hypothesized that in using these discrete speech recognition systems, there may be a tendency to maintain constant pitch, volume, and inflection, keeping the vocal tract musculature in a fixed position. Maintaining this fixed position for extended periods may result in muscle fatigue and, eventually, injury to the laryngeal musculature. Further studies are needed, however, to investigate the effects suggested here. In the meantime, we recommend that users become informed about the unnatural speech patterns used with discrete speech recognition systems; learn to use good vocal hygiene, such as performing warm-up and cool-down voice exercises; and use alternate methods of input along with the speech recognition product.

Aphonia↗

PubMed1997

Lead poisoning and associated risk factors among preschoolers enrolled in a Head Start program.

Despite the fact that lead poisoning is one of the most common pediatric health problems in the United States today, little is known about the prevalence and correlates of this disease among nonurban preschool children living in the southern United States. The purpose of this study was to measure the prevalence of abnormal lead levels and to explore the relationships between lead levels and gender, weight, hemoglobin, and ethnicity. Using a chart review protocol, data were collected from 81 charts of children enrolled in a Head Start program in Florida. The prevalence rate of elevated lead levels was 18.5%, a rate higher than that found in most previous research. No relationship was found between lead levels and gender, weight, hemoglobin, and ethnicity. The results highlight the importance of local screening efforts. Controversies in screening are discussed in this article in some detail with the aim of assisting health care providers make decisions about whether universal screening for lead levels in children is appropriate and whether use of the Centers for Disease Control questionnaire has sufficient value. Further study is needed regarding prevalence rates in different geographic areas in the United States, and factors associated with elevated lead levels.

Child Health Services↗

PubMed1997

A longitudinal study of developmental outcome of infants with bronchopulmonary dysplasia and very low birth weight.

OBJECTIVE: Bronchopulmonary dysplasia (BPD) is now the leading cause of lung disease in US infants. In a large regional cohort, we tested the hypothesis that despite innovations in neonatal care, very low birth weight (VLBW) infants (<1500 g) with BPD had poorer developmental outcomes than nonaffected infants during the first 3 years of life, and that BPD predicted poorer outcome beyond the effects of other risk factors. METHODS: Three groups of infants (122 with BPD, 84 VLBW without BPD, and 123 full-term) were followed longitudinally to 3 years of age with the Bayley Scales of Mental and Motor Development. Comparison groups of VLBW infants without BPD and full-term infants did not differ in sex, race, or socioeconomic status. Statistical analyses included hierarchical and stepwise multiple regression. RESULTS: Infants with BPD performed more poorly at all ages. By 3 years, cognitive and/or motor development was in the range of retardation (<70 standard score) for 21% to 22% of infants with BPD. In multiple regression analyses controlling for socioeconomic and neonatal risk conditions, BPD had an independent negative effect on motor outcome at 3 years. Neurologic risk, a summary measure of neurologic problems other than intraventricular hemorrhage, and the presence of BPD independently predicted motor delay. By 3 years, social class, race, and neurologic risk predicted mental outcome, suggesting that the specific effects of BPD are primarily on the motor domain. CONCLUSIONS: In VLBW infants, BPD predicts poorer motor outcome at 3 years, after control for other risks. Cohorts of infants with BPD also had higher rates of mental retardation, associated with greater neurologic and social risk. These findings underscore the need for intensive prevention and habilitation efforts for this growing group of VLBW survivors, as well as investigation into the potential role of BPD in the higher rates of learning disabilities in VLBW cohorts at school age.

Bronchopulmonary Dysplasia↗

PubMed1997

[Mechanisms of drug interactions with renal elimination of lithium].

Using indomethacin (2.5 mg/kg/day, i.m.) in rats, we confirmed the well-known interaction of NSAID's and the urinary elimination of lithium. This is due to an increase in the tubular reabsorption of lithium, probably associated with an increase in the reabsorption of sodium in the ascending limb of the loop of Henle, following inhibition of the synthesis of prostaglandins. With ramipril (1 mg/kg/day, p.o.), we confirmed an interaction with lithium pharmacokinetics in rats, also associated with an increase in the tubular reabsorption of sodium. In contrast, the angiotensin receptor antagonist losartan (10 mg/kg/day, p.o.) had no effect in this paradigm. Since the effects of ramipril were partially inhibited by an i.v. infusion of an antagonist of the bradykinin B2 receptor icatibant (0.1 mg/kg/day), we suggest that bradykinin contributes to the interaction between angiotensin converting enzyme inhibitors and renal excretion of lithium.

Animals↗

PubMed1996

Inherited complement C3 deficiency: reduced C3 mRNA and protein levels in a Laotian kindred.

To determine the molecular basis of complement C3 deficiency in a Laotian kindred, the homozygous C3-deficient male propositus was studied. By ELISA, this individual's serum was determined to contain approximately 4 microg/ml C3 (0.3% of normal). In accord with this result, anti-C3 immunoprecipitation of [35S]-methionine-labeled fibroblasts from this C3D individual revealed pro-C3 of normal size (180,000 Mr), but in significantly reduced amounts (approximately 1% of normal fibroblasts), that was processed and secreted with normal-size alpha- and beta-chains. In addition, C3-specific mRNA of normal size (5.2 kb) but in reduced quantity (approximately 1% of normal) was detected in this individual's fibroblasts by Northern analysis. The nucleotide sequence of the transcriptional initiation site, the promoter, and the IL-1beta/IL-6 cis-regulatory elements of the C3-deficient gene are normal in this C3-deficient individual, indicating that the low C3 mRNA and protein levels are not caused by reduced C3 transcription that is the result of a cis-mutation. Moreover, cDNA sequencing studies revealed no defect in the C3-deficient mRNA, including the areas mutated in four previously characterized C3-deficient patients. These data indicate that (1) C3 protein deficiency in this Laotian patient results from reduced levels of C3-specific mRNA, (2) the small amount of expressed C3 protein is processed and secreted normally from the deficient cells, and (3) the molecular genetic defect(s), although not yet delineated, is different from those described in other C3-deficient individuals, thereby providing additional evidence for numerous mutations that cause inherited C3 deficiency in humans.

Cells, Cultured↗

PubMed1996

Is cognitive psychopathology plausible? Illustrations from memory research.

OBJECTIVE: To examine the strengths and weaknesses of cognitive psychopathology through the specific examples of the memory impairments associated with the administration of benzodiazepines, with schizophrenia, and with depression. METHOD: These examples are analyzed with reference to a model of memory based on the principle of division between specialized and central processing structures. A basic contention is that it is useful to consider 2 broad classes of processes-automatic, associative, or sensory/perceptual processes on the one hand and intentional, strategic, or reflective processes on the other hand-as being separate. RESULTS: The functional mechanisms of the memory impairments associated with these conditions are beginning to be identified, and there is preliminary evidence that a deficit in an elementary computation may have dramatic consequences on highest cognitive functions. There is also evidence that certain memory impairments are linked to specific dysfunctional outcomes in everyday life. By showing that specific rate-limiting factors of cognitive performance can be identified and are amenable to cognitive interventions, existing data open the door for theoretically and empirically based cognitive remediation of mental disorders. CONCLUSION: The bulk of available evidence (albeit limited) makes the enterprise of cognitive psychopathology quite plausible and convincing.

Activities of Daily Living↗

PubMed1995

Increased psychological distress in post-partum, cocaine-using mothers.

This study investigated psychological symptoms, self-reported postpartum by poor, primarily African American women who used cocaine during pregnancy. Ninety-nine cocaine-using mothers (COC+) were compared to 44 noncocaine-using mothers (COC-) on standardized measures of psychological distress and verbal comprehension. Mothers were interviewed to determined extent of drug involvement. COC+ mothers reported using alcohol, marijuana, and tobacco at two to three times the rate of comparison mothers during pregnancy and reported earlier initiation of marijuana use. COC+ women were more likely to admit to interpersonal difficulties and to report phobic anxiety and paranoid ideational symptoms. The COC+ group was also more likely to have clinically elevated scores on subscales indicating feelings of personal inadequacy, phobic anxiety, and paranoia. The use of cocaine, in combination with either alcohol or marijuana, was the best predictor of psychoticism, hostility, and total number of distress symptoms.

Adult↗

PubMed1995

Mothers touching newborns: a comparison of rooming-in versus minimal contact.

We compared the maternal behaviors of women who had extended and early contact (rooming-in) with their infants with those who had contact only during feedings. Thirty-one young, unmarried, predominantly black, lower-socioeconomic mothers and their infants were observed in the mother's hospital room for 15 minutes after a morning feeding approximately 18 hours after delivery. A time sample unit checklist was used to record each mother's behavior, looking, talking, and touching directed toward their infants and others, as well as watching television and talking on the telephone. Analyses of variance revealed that the rooming-in mothers looked at, talked to, and touched their infants more, watched less television, and talked less on the telephone than mothers with minimal contact with their infants. These findings suggest that increased postpartum contact with infants leads not only to more interaction, but also to more touching as well as touching in more intimate places (face and head), thus highlighting the value of rooming-in arrangements for mothers and infants.

Adolescent↗