Biomedical subjects

R Brown

Publications and source records attributed to R Brown.

At least 91 records · Page 5Linked to original sources

PubMed2001

In vivo measurement of lung volumes in mice.

We describe longitudinal measurements of functional residual capacity (FRC) in breathing mice using a clinical computed tomography (CT) scanner. Lungs of anesthetized mice from the A/J and C3H/HeJ strains were scanned over a 10-s period. Using a fixed threshold for CT density, we could accurately and reproducibly obtain the amount of air in the lungs at FRC, with a 10% coefficient of variation. Total lung volume, and the fractions in left and right lungs, were measured in the two strains from 4 to 12 wk of age. Results show that in both strains the FRC increases only up to 6 wk of age and then remains stable despite a steady increase in body weight. Over this time period, FRC was consistently about 50% greater in the C3H/HeJ strain compared with the A/J strain. The C3H/HeJ strain also has a significantly smaller fraction of the total lung volume in the left lung. We conclude that accurate measurements of FRC in breathing mice can be made using a standard clinical CT scanner. This method may be useful for repeated noninvasive assessment of both structural and functional changes in the lungs of experimental and genetically manipulated mice.

Animals↗

PubMed2001

Aromatherapy and behaviour disturbances in dementia: a randomized controlled trial.

A random controlled trial of the relaxing effects of an aromatherapy massage on disordered behaviour in dementia was conducted. Twenty-one patients were randomly allocated into one of three conditions, aromatherapy and massage (AM), conversation and aromatherapy (CA) and massage only (M). AM showed the greatest reduction in the frequency of excessive motor behaviour of all three conditions. This reached statistical significance between the hours of three and four pm (p < 0.05). Post hoc analysis suggested that at this time of day the AM consistently reduced motor behaviour when compared with CA (p = 0.05). This provides preliminary evidence of a measurable sedative effect of aromatherapy massage on dementia within a robust scientific paradigm. Further research is recommended with an expanded sample size.

Aged↗

PubMed2001

Mothers' evaluation of their caregiving for premature and full-term infants through the first year: contributing factors.

We explored change in mothers' evaluations of their caregiving through the first postterm year for full-term infants and for prematurely born, very low birth-weight infants with a history of lung disease, and we examined the contribution to this evaluation of infant, family, and mother conditions. Fifty-four mothers of premature infants and 49 mothers of full-term infants evaluated their caregiving relationship, performance, and satisfaction at 1, 4, 8, and 12 months infant postterm age. In addition, at the same intervals-1, 4, 8, and 12 months-mothers rated their symptoms of depression, infant responsiveness, and satisfaction with help from husband or partner. Positive and negative feeding behaviors of mother and of infant were rated from videotapes. Regression analysis, which included all rated variables, infant birth maturity/lung health status, and number of children in the mother's care, showed that the 1-month assessment differed significantly from the assessments at 4, 8, and 12 months. All conditions, except for infant birth maturity/lung health status and mother's positive feeding behavior, were significantly associated with caregiving evaluation. Findings support inclusion of infant, family, and mother conditions in a caregiving evaluation model. Infant responsiveness may be particularly salient to a mother's caregiving evaluation.

Adult↗

PubMed2001

Effects of biologic and experiential conditions on the pattern of growth in weight of premature and full-term infants.

In this exploratory study we examined the contribution of biologic and experiential conditions to the pattern of growth in weight for premature and full-term infants. The three components of the pattern were: (a) the infant's weight level; (b) the linear growth rate; and (c) the quadratic growth rate. Biologic conditions were maturity at birth and gender. Experiential conditions included variables in the mother's caregiving and the infant's feeding behavior, nutrient intake, and acuity of illness. At 1, 4, 8, and 12 months, premature infants (n = 61) weighed significantly less than full-term infants (n = 53), but neither linear nor quadratic rates of weight gain were significantly different from the rates for the full-term infants. Multilevel analytic models showed that female gender significantly affected weight level and linear and quadratic growth rates. Negative affect and behavior in both the mother and the infant significantly increased the linear rate of weight gain. The interaction of several experiential conditions with the two biologic conditions, birth maturity and gender, affected growth outcomes. Further exploration of the model with a larger sample is indicated to enable simultaneous testing of biologic and experiential conditions.

Adolescent↗

PubMed2001

What the general psychiatrist should know about herbal medicine.

The use of complementary and alternative medicine (CAM) has increased tremendously over the past 10 years. As a result of the increase physicians must understand both the factual information about CAM practices and the psychologic reasons patients seek out such treatments. A particular concern is the use of CAM by patients without the knowledge of their physicians, which may lead to complications resulting from interactions, or adverse effects from treatments of which the physician is unaware. This paper reviews research concerning the use of CAM by patients, explores some of the psychodynamic factors in CAM use, and suggests means of integrating that use into the patient's therapy. Specific information about herbal and other alternative products is provided.

Humans↗

PubMed2001

Primary ovarian carcinomas display multiple methylator phenotypes involving known tumor suppressor genes.

Mounting evidence suggests that aberrant methylation of CpG islands is a major pathway leading to the inactivation of tumor suppressor genes and the development of cancer. Recent studies on colorectal and gastric cancer have defined a CpG island methylator phenotype (CIMP), which involves the targeting of multiple genes by promoter hypermethylation. To determine the role of methylation in ovarian cancer, we have investigated the methylation status of 93 primary ovarian tumors at ten loci using methylation-specific polymerase chain reaction (MSP). Seven of the loci (BRCA1, HIC1, MINT25, MINT31, MLH1, p73 and hTR) were found to be methylated in a significant proportion of the ovarian tumors, and methylation of at least one of these was found in the majority (71%) of samples. Although concurrent methylation of multiple genes was commonly seen, this did not seem to be due to a single CIMP phenotype. Instead the results suggest the presence of at least three groups of tumors, two CIMP-positive groups, each susceptible to methylation of a different subset of genes, and a further group of tumors not susceptible to CpG island methylation, at least at the loci studied.

Adaptor Proteins, Signal Transducing↗

PubMed2001

Intranasal mupirocin reduces sternal wound infection after open heart surgery in diabetics and nondiabetics.

BACKGROUND: This study was designed to determine whether decreasing nasal bacterial colonization by applying Mupirocin (MPN) intranasally decreases sternal wound infections. METHODS: We prospectively followed 992 consecutive open heart surgery (OHS) patients who did not receive MPN prophylaxis (group I) from January 1, 1995 to October 31, 1996. Group II consisted of 854 consecutive patients followed prospectively from December 1, 1997 to March 31, 1999 treated with intranasal MPN given on the evening before, the morning of OHS, and twice daily for 5 days postoperatively. RESULTS: There was a significant difference in the rate of overall sternal wound infections between the untreated (group I) and the treated group (group II): 2.7% (27 of 992) versus 0.9% (8 of 854) (p = 0.005). The difference was also significant in the diabetic subgroup: 5.1% (14 of 277) (group I) versus 1.9% (5 of 266) (group II) (p = 0.04) and the nondiabetic group: 1.8% (13 of 715) (group I) versus 0.5% (3 of 588) (group II) (p = 0.03). The cost of MPN treatment was $12.47 per patient compared with $81,018 +/- $41,567 for a deep wound infection with no antibiotic-related complications recorded. CONCLUSIONS: Prophylactic intranasal MPN is safe, inexpensive, and very effective in reducing the overall sternal wound infections by 66.6%.

Administration, Intranasal↗

PubMed2001

Immunoregulatory role of secreted glycoprotein G from respiratory syncytial virus.

The secretory glycoprotein (Gs) of respiratory syncytial virus (RSV) was enriched and investigated for its effects on T cells specific for RSV and unrelated antigens. Gs exhibited a dose dependent suppression of lymphoproliferative responses in peripheral blood mononuclear cells (PBMCs), specific for mycobacterial lysates or tetanus toxoid. However, Gs did not inhibit live RSV specific T cell responses. These results suggest that Gs may suppress immune response to unrelated antigens, but should not interfere with the overall development of RSV specific immunity.

Adult↗

PubMed2001

Safety and predictability of laser in situ keratomileusis enhancement by flap reelevation in high myopia.

PURPOSE: To evaluate the safety and predictability of laser in situ keratomileusis (LASIK) retreatment following primary procedures for high myopia and astigmatism. SETTING: Corneal Diseases and Excimer Laser Research Unit, Department of Ophthalmology, University of Dundee, Dundee, United Kingdom. METHODS: This prospective observational study of retreatment comprised a cohort of 109 eyes having primary LASIK for high myopia and astigmatism with a spherical equivalent (SE) of -9.70 diopters (D) +/- 4.06 (SD). Twenty-four eyes (22%) with an initial myopic SE of -9.83 +/- 3.50 D, a comparable subset of the entire group (P < .05), had retreatment for residual myopia (-3.02 +/- 2.17 D) to improve uncorrected visual acuity (UCVA) by reelevating the corneal flap and ablating the stromal bed. RESULTS: The mean follow-up after retreatment was 12.8 +/- 5.1 months (range 1.5 to 24 months; 19 eyes >/=6 months, 13 eyes > or = 12 months). The mean myopic SE was reduced to +0.53 +/- 0.62 D at 1 week, +0.05 +/- 0.50 D at 1 month, +0.30 +/- 0.50 D at 6 months, and +0.18 +/- 0.42 D at the latest follow-up, 12.8 months. At the latest review, 62% of eyes were within +/-0.50 D of emmetropia and 100% were within +/-1.00 D. The mean refraction did not alter statistically between 1 week and subsequent times. The mean UCVA improved from 6/30 prior to retreatment to 6/9 at the latest follow-up. Uncorrected visual acuity of 6/6 or better, 6/9 or better, and 6/12 or better was achieved by 33.0%, 75.0%, and 95.8% of eyes, respectively. No significant complications that led to a loss of best corrected visual acuity were encountered, although retreatment procedures were more uncomfortable than primary procedures and self-limiting; epithelial ingrowth that did not threaten vision was common, and 2 patients complained of nighttime visual symptoms. CONCLUSIONS: Retreatment of residual myopia by reelevating the flap was relatively safe and predictable, with a low risk of sight-threatening complications. However, longer term studies may be required to detect late complications.

Adult↗

PubMed2001

Low incidence of transplantation-related acute complications in patients with chronic myeloid leukemia undergoing allogeneic stem cell transplantation with a low-dose (550 cGy) total body irradiation conditioning regimen.

Although allogeneic transplantation is a curative therapy for chronic myeloid leukemia (CML), treatment-related mortality is still a major cause of posttransplantation mortality, especially for patients older than 40 years. We investigated, in a phase II trial, the role of a low-dose (550 cGy) high-dose rate (35 cGy/min) single-exposure total body irradiation (TBI) conditioning regimen for allogeneic peripheral blood stem cell (PBSC) transplantation in patients with CML. Between June 1997 and August 2000, 30 adult patients with CML underwent cytokine-mobilized allogeneic PBSC transplantation from HLA-matched siblings following administration of cyclophosphamide (60 mg/kg per day intravenously on days -2 and -1) and single-dose TBI (550 cGy delivered at 30 cGy/min on day 0). Cyclosporine A alone was administered for prophylaxis against graft-versus-host disease (GVHD). Median patient age was 47 years (range, 21-63 years), with 23 patients (77%) older than 40 years. The preparative regimen was well tolerated. Grade 4 toxicities and oral mucositis were not observed. Graft failure did not occur. Severe acute GVHD was observed in 5 patients (17%). The median follow-up was 23 months (range, 6-39 months). Cytogenetic or hematologic relapse was detected in 3 patients (10%), 2 of whom subsequently entered remission following a taper of immunosuppression. Nonrelapse mortality occurred in 5 patients (17%), and the Kaplan-Meier estimate of survival at 2 years was 83% (95% confidence interval, 70%-97%). In summary, this low-dose TBI-based preparative regimen resulted in uniform donor engraftment, with markedly reduced organ toxicity and nonrelapse mortality, in this relatively older cohort of patients with CML.

Acute Disease↗

PubMed2001

Brief report: Lack of correlation between age of symptom onset and contemporaneous presentation.

The parents/guardians of 50 individuals were surveyed using a semistructured interview to determine the feasibility of this method and to establish ages of symptom onset. Thirty-eight informants were able to recall sufficient detail to allow categorization of the age of symptom onset. Chi-square analysis confirmed a significant association between investigators' categorization and informants' categorization. Contemporaneous presentation was indexed using Childhood Autism Rating Scale, the Autism Behavior Checklist, the Conners Hyperactivity Index, and the Ritvo-Freeman Real Life Rating Scale for Autism. No significant correlations were determined between any of these indices of symptom severity and age of symptom onset.

Adolescent↗

PubMed2001

Symptoms of depression and survival experience among three samples of smokers trying to quit.

Symptoms of depression have been associated with increased smoking prevalence and failure to quit smoking in several cross-sectional and population-based studies. Few studies, however, have prospectively examined the ability of current symptoms of depression to predict failure to quit smoking in treatment-motivated smokers. Pretreatment depressed mood was assessed by 3 different methods in 3 separate samples, 2 of which comprised smokers receiving combined pharmacological and behavioral treatments and a 3rd in which smokers received self-help materials only. In all studies, time in days from quit day until the 1st cigarette was ascertained to document survival. Survival analyses showed that in all 3 studies survival time was significantly and negatively related to measures of even very low levels of pretreatment depressed mood. Results were replicated across 3 independent samples and were robust and uniformly clear, indicating that low levels of depressive symptoms assessed at baseline predict time to 1st cigarette smoked after attempted quitting.

Adult↗

PubMed2001

A conserved sorting-associated protein is mutant in chorea-acanthocytosis.

Chorea-acanthocytosis (CHAC, MIM 200150) is an autosomal recessive neurodegenerative disorder characterized by the gradual onset of hyperkinetic movements and abnormal erythrocyte morphology (acanthocytosis). Neurological findings closely resemble those observed in Huntington disease. We identified a gene in the CHAC critical region and found 16 different mutations in individuals with chorea-acanthocytosis. CHAC encodes an evolutionarily conserved protein that is probably involved in protein sorting.

Alternative Splicing↗

PubMed2001

Replication and cytolysis of an E1B-attenuated adenovirus in drug-resistant ovarian tumour cells is associated with reduced apoptosis.

Therapeutic approaches which are effective in tumour cells resistant to conventional chemotherapy would be of value. An E1B 55 kDa-deleted adenovirus (ONYX-015) induces lysis in cells with mutant p53, although the specificity of these observations for different cell types is unclear. We have used a matched set of drug-resistant human ovarian tumour cell lines to examine the potential of ONYX-015 for preferential replication and lysis of drug-resistant ovarian tumour cells with documented alterations in p53 function. Marked preferential replication of ONYX-015 is observed after infection of mutant p53 transfectant and cisplatin-resistant derivatives, compared to the wild-type p53 expressing parental A2780 line. Infection causes increased cytopathic effects in vitro and inhibition of tumour growth in vivo of the drug-resistant derivatives, but not the parental line. In apparent contrast, increased apoptosis and reduced clonogenic survival is induced by ONYX-015 infection of the chemosensitive parental cell line. ONYX-015 induces increased pro-apoptotic BAX and reduced anti-apoptotic BCLX(L) in parental cells, but not in the resistant derivative A2780/cp70. We propose that induction of apoptosis is one factor which prevents ONYX-015 spread and cytolysis after infection of chemosensitive cells, while it is the failure to engage apoptosis in drug-resistant cells that allows preferential viral replication, spread and cytolysis.

Adenoviridae↗

PubMed2001

The relationship of a mother's working model of feeding to her feeding behaviour.

AIMS OF THE STUDY: This study aimed to examine the difference the attunement of a mother's working model of feeding to her infant makes for her positive feeding affect and behaviour, accounting for infant and mother conditions. BACKGROUND/RATIONALE: The concept of a mother's working model of feeding is derived from attachment theory. Caregiving, including feeding, is a component of this theory. The conditions that may influence the attunement of a mother's working model of feeding to her infant include infant birth maturity status (premature, full-term), age at assessment, and robustness, indexed by weight-for-age z score (WAZ). Mother conditions include symptoms of depression and feeding practice (breast feeding or exclusive bottle feeding). DESIGN/METHODS: Participants in this longitudinal study were 99 mothers and their infants (47 full-term, 52 premature, very low birth weight). After written informed consent was given, home assessments were made when infants were approximately 1, 4, 8 and 12 months old (adjusted age for premature infants). Working model attunement was assessed with a video-assisted interview. A mother's positive affect and behaviour, including sensitivity and responsiveness, were rated from videotaped feeding interaction. RESULTS/FINDINGS: Repeated measures analysis with a general linear mixed model showed a significant positive relationship with positive affect and behaviour for both working model attunement and the WAZ score and a significant negative relationship for symptoms of depression. Neither birth maturity status, infant age, nor feeding practice had a significant effect on mother's positive affect and behaviour during feeding. CONCLUSIONS: Nurses' efforts to enhance the attunement of a mother's working model of feeding may help mothers feed with greater positive affect and behaviour. Further study of how the attunement of a mother's feeding expectations and intentions are related to her symptoms of depression and with what she makes of the infant's growth and well-being is needed. The theoretical model needs testing with infants from the entire premature population.

Adult↗

PubMed2001

Australian Indigenous mental health.

Understanding the complexity of another culture's health concerns is fraught with difficulty, yet 'ways forward' abound. Many researchers, including Indigenous people, have recorded cultural understandings of health, and made recommendations that have influenced the planning of Indigenous peoples' mental health care. Indeed, there is anticipation with vision for the future. Australian Indigenous people have suffered many losses, which have resulted in much social unrest, and mental and spiritual sorrow. The difficulty of belonging and adjusting to two different cultural contexts has led to particular physical health and mental health concerns for some. Health for Indigenous people is viewed within a holistic and community lifestyle framework, which is related to both past and present issues, and it is not necessarily individualized or compartmentalized. A closer liaison between the health traditions of both cultures, working together with education, good will and understanding of each other's health business, and working together within mainstream health services may assist with healing, reconciliation and improved Aboriginal holistic health.

Acculturation↗

PubMed2001

Maternal transmission of nicotine dependence: psychiatric, neurocognitive and prenatal factors.

This paper reviews the literature on maternal influences on smoking behaviors of offspring from the perspective of neuropsychiatric deficits that may be transmitted from mother to child. In particular, we review what is known regarding associations between: (1) in-utero exposure to smoking, (2) adolescent neurocognitive functioning and psychiatric comorbidity, and (3) the patterns of smoking and progression of nicotine dependence. Furthering our knowledge of these differences in susceptibility to nicotine dependence among youth will provide additional avenues for prevention and intervention efforts targeted toward those at high risk for dependence.

Adolescent↗

PubMed2001

Predictors of loud snoring in persons with spinal cord injury.

BACKGROUND: Predictors of loud snoring were examined in a cohort of 197 persons with chronic spinal cord injury (SCI) recruited by advertisement and from a Veterans Affairs Medical Center SCI Service. METHODS: Data were collected on age, marital status, antispasticity medications, duration of injury, level and completeness of injury, stature, and weight. Body mass index (BMI) was calculated for all participants. A health questionnaire was used to collect data on snoring and respiratory history. Habitual snorers were defined as those who reported loud snoring more than 1 night per week. RESULTS: The mean age (+/- SD) was 51.2 +/- 14.8 years, and 84 of 197 (42.6%) were habitual snorers. The most obese research subjects, regardless of antispasticity medication use, were more likely to report snoring, but the risk of snoring was greatest among subjects who were obese and used antispasticity medication. Subjects who used antispasticity medication and had a BMI above the median (> or = 25.3 kg/m2) had a 7-fold risk of reporting snoring compared with subjects below the median who did not use antispasticity medication (P = .001). The greatest risk occurred in those who used diazepam alone or baclofen and diazepam together and had a BMI at or above the median. Subjects who used these medications and had a BMI below the median did not have a significantly increased risk. Neurological motor completeness, level of injury, age, and years since injury were not significant predictors of snoring. CONCLUSION: Because snoring is a marker for obstructive sleep apnea (OSA), the data suggest that in obese individuals with SCI, the use of antispasticity medications may be a risk factor for OSA.

Adult↗