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Biomedical subjects

J Stone

Publications and source records attributed to J Stone.

At least 37 records · Page 2Linked to original sources
PubMed2003

The outcome of depressive disorders in neurology patients: a prospective cohort study.

BACKGROUND: In a previous prospective study of 300 consecutive new attenders at neurology outpatient clinics, depressive disorders were diagnosed in 119 patients (40%) and major depressive disorder in 77 (26%). OBJECTIVE: To describe the eight month outcome of depression in this cohort. METHODS: Patients were reinterviewed eight months after their baseline assessment. Mental state was examined using the primary care evaluation of mental disorders (PRIME-MD) interview and the hospital anxiety and depression (HAD) self rating scale. Health status was measured using the medical outcome study 36 item short form scale (SF-36). RESULTS: Of the original cohort of 300, 226 (75%) participated in the follow up. Among them, 88 had a depressive disorder at baseline and 69 (78%) of those were still depressed at follow up; 54 had major depression at baseline and 46 (85%) of those still had a major depressive disorder at follow up. Among the 138 patients who had no depression at baseline, 20 new major depressive disorders had developed by the time of follow up. Resolution of major depressive disorders was associated with an improvement in health status. CONCLUSIONS: Most depressive disorders detected in neurology outpatients persist at an eight month follow up, and a substantial number of new cases arise. Resolution of depressive disorders, particularly major depressive disorder, is associated with an improvement in health status.

Adult↗
PubMed2003

The outcome of neurology outpatients with medically unexplained symptoms: a prospective cohort study.

BACKGROUND: In a previous cross sectional study of 300 consecutive new attenders at neurology outpatient clinics, 90 were detected with symptoms that were rated as "not at all" or only "somewhat" explained by organic disease. OBJECTIVE: To report a follow up study of this cohort. METHODS: Patients were reinterviewed by telephone eight months after their initial assessment. They were asked to rate their overall improvement on a clinical global improvement scale, and their health status on the medical outcome short form 36 item scale (SF-36). The PRIME MD interview was administered to determine psychiatric diagnoses. Neurological and primary care records were reviewed for any changes in diagnostic opinion during the follow up period. RESULTS: Of the 90 eligible patients, 66 (73%) participated in follow up. Among these, five (8%) rated themselves as "much worse," four (6%) as "somewhat worse," 27 (40%) as "just the same," 15 (23%) as "somewhat better," and 15 (23%) as "much better." There were no cases in which an organic cause for the presenting complaint was uncovered during the follow up period. Poorer physical function at baseline was the only predictor of poorer outcome at follow up. CONCLUSIONS: Over half the patients who presented to neurologists with symptoms that were rated as largely or completely medically unexplained had not improved eight months later. In no case was a disease explanation for the original presenting symptoms subsequently identified.

Adult↗
PubMed2003

Distinct genetic and epigenetic changes in medullary breast cancer.

Genetic instability resulting in chromosome aneuploidy or mismatch repair deficiency characterizes cancer. Medullary carcinoma (MC) of the breast is a specific form of breast cancer with unique clinical, epidemiologic, and prognostic features, suggesting distinctive tumorigenic pathways. To investigate the nature of the genetic changes associated with MC we analyzed a series of 22 tumors. Chromosomal imbalances were assessed by comparative genomic hybridization (CGH) and mismatch repair (MMR) deficiency tested for through assessment of microsatellite instability (MSI) and expression of MLH1 and MSH2 genes. MMR deficiency was detected in only a small proportion of cases. The chromosomal copy number changes showed some similarities to BRCA1-associated tumors. A high level of BRCA1 promoter hypermethylation was detected, suggesting a possible role of this gene in MC development.

Adaptor Proteins, Signal Transducing↗
PubMed2003

The detection of change in mammographic density.

Mammographic density is associated with risk of breast cancer, and factors that change density may also change risk. There has, however, been little research into how change in serial mammograms is best detected. The purpose of the work described here was to examine the effects of different reading conditions on the detection of change in mammographic features. Mammograms were selected from women who had participated in a randomized controlled trial of screening for breast cancer. We selected two age-matched groups of subjects, one had undergone menopause after entry (n = 202) and another who had not (n = 202). Serial mammograms from these subjects were then measured four times using a computer-assisted method under different conditions: (a) films were randomized; (b) subjects were randomized (i.e., pairs of films from individuals were read one after the other), but the order of films was random and unknown to the reader; (c) subjects were randomized, and the order of films was sequential and known to the reader; and (d) subjects were randomized, and the order of films was random and unknown to the reader, but both films in each pair were read simultaneously on separate computer screens. The mean effect of the menopause on change in the mammographic measures of total, dense and nondense areas, percent density, and the associated variances were then compared. With one exception, all of the randomization and viewing methods confirmed a change in all mammographic measures at menopause and produced very similar overall results, suggesting that mammographic density is a robust measure. Compared with randomization of all films, the method in which subjects were randomized and paired films read one after the other in random and unknown order was associated with a slightly smaller mean difference and achieved a substantial reduction in variability, suggesting that it is the most sensitive method of randomization and viewing for the detection of change.

Breast↗
PubMed2002

The association of breast mitogens with mammographic densities.

Radiologically dense breast tissue (mammographic density) is strongly associated with risk of breast cancer, but the biological basis for this association is unknown. In this study we have examined the association of circulating levels of hormones and growth factors with mammographic density. A total of 382 subjects, 193 premenopausal and 189 postmenopausal, without previous breast cancer or current hormone use, were selected in each of five categories of breast density from mammography units. Risk factor information, anthropometric measures, and blood samples were obtained, and oestradiol, progesterone, sex hormone binding globulin, growth hormone, insulin-like growth factor-I and its principal binding protein, and prolactin measured. Mammograms were digitised and measured using a computer-assisted method. After adjustment for other risk factors, we found in premenopausal women that serum insulin-like growth factor-I levels, and in postmenopausal women, serum levels of prolactin, were both significantly and positively associated with per cent density. Total oestradiol and progesterone levels were unrelated to per cent density in both groups. In postmenopausal women, free oestradiol (negatively), and sex hormone binding globulin (positively), were significantly related to per cent density. These data show an association between blood levels of breast mitogens and mammographic density, and suggest a biological basis for the associated risk of breast cancer.

Adult↗
PubMed2002

Delayed prezygotic isolating mechanisms: evolution with a twist.

Assortative mating characterizes the situation wherein reproducing individuals pair according to similarity. Usually, the impetus for this bias is attributed to some type of mate choice conferring benefits (e.g., increased fitness or genetic compatibility) and, thereby, promoting speciation and phenotypic evolution. We investigate, by computer simulation of an evolving deme-structured snail population, the ramifications ensuing from passive assortative mating wherein couples exhibiting opposite shell coil direction phenotypes experience a physical constraint on mating success: putative mating partners inhabiting stout dextral and sinistral shells are unable to exchange sperm. Because shell coil chirality genotype is encoded at a single locus by shell coil alleles that are inherited maternally, snails containing sinistral alleles can present the typical dextral phenotype. Consequently, the incidence of a sinistral allele in as few as one snail can be manifested as prezygotic reproductive isolation within a deme in a subsequent generation. However, because the efficacy of achieving this type of prezygotic reproductive isolation is affected by shell form, the likelihood and product of single-gene speciation should be determined by deme interaction (migration) and composition (morphological distribution). We test this hypothesis and show how stochastic migration interacts with passive assortative mating yielding morphologically induced prezygotic reproductive isolation to produce new species phenotypes. The results show that demes can achieve rapid macroscopic phenotypic transformation and indicate that sympatric speciation might be more plausible than naturalists recognize conventionally.

Alleles↗
PubMed2002

Cleanup of gloves contaminated with granular terbufos and tefluthrin.

Chemical-resistant gloves are used for protection from pesticides in farming operations. Cleanup of gloves after pesticide contamination was the focus of this research. Nitrile, neoprene, and barrier laminate glove specimens were exposed to 300 mg terbufos or tefluthrin granules for 3 or 30 min in petri dishes in a laboratory. Specimens were cleaned by flush with running water or LaunderOmeter washing with detergent. Following the cleanup treatments, specimens were dried and placed in test tubes with solvents to extract pesticide residue. Levels of contamination remaining were determined by gas chromatography. The residue remaining varied with exposure time, material type, cleanup method, and pesticide. Flush was more effective with the shorter exposure time. Tefluthrin was more effectively removed than terbufos. Barrier laminate was confirmed as a single-use material. Cleanup procedures reduced contamination in nitrile and neoprene, but findings show that these materials retained residue after cleanup.

Agriculture↗
PubMed2002

Functional weakness and sensory disturbance.

In the diagnosis of functional weakness and sensory disturbance, positive physical signs are as important as absence of signs of disease. Motor signs, particularly Hoover's sign, are more reliable than sensory signs, but none should be used in isolation and must be interpreted in the overall context of the presentation. It should be borne in mind that a patient may have both a functional and an organic disorder.

Conversion Disorder↗
PubMed2002

Are functional motor and sensory symptoms really more frequent on the left? A systematic review.

OBJECTIVES: To test the hypothesis that unilateral motor and sensory symptoms unexplained by identifiable disease are more common on the left side of the body than the right. METHODS: Systematic review of the literature published since 1965. RESULTS: 121 eligible studies, involving 1139 patients, were analysed. The pooled proportion of functional left sided weakness and sensory symptoms in adults was 58% (95% confidence interval (CI) 55 to 61%). A much higher proportion of left sided symptoms (66%, 95% CI 61 to 71%) was found in studies where laterality featured in the title of the paper. However, when laterality was not mentioned in the title, no significant difference between left and right was observed (53% on the left, 95% CI 48 to 57%). This difference could not be explained on the basis of sex differences between the groups or the date of the study. Functional or "psychogenic" movement disorder was right sided in 68% (95% CI 61 to 75%). Handedness did not influence symptom lateralisation. CONCLUSIONS: The findings of this systematic review question whether functional weakness and sensory symptoms do in fact occur more commonly on the left side of the body. A type of outcome variable reporting bias in combination with non-blinding of investigators may be responsible for this long held but erroneous belief.

Aged↗
PubMed2001

Single vs weekly courses of antenatal corticosteroids for women at risk of preterm delivery: A randomized controlled trial.

CONTEXT: The practice of administering weekly courses of antenatal corticosteroids to pregnant women at risk of preterm delivery is widespread, but no randomized trial has established the efficacy or safety of this practice. OBJECTIVES: To evaluate the efficacy of weekly administration of antenatal corticosteroids compared with a single course in reducing the incidence of neonatal morbidity and to evaluate potential complications of weekly treatment. DESIGN AND SETTING: Randomized, double-blind, placebo-controlled intention-to-treat trial conducted in 13 academic centers in the United States from February 1996 through April 2000. PARTICIPANTS: A total of 502 pregnant women between 24 and 32 completed weeks' gestation who were at high risk of preterm delivery. INTERVENTION: All patients received a complete single course of antenatal corticosteroids (either betamethasone, 12 mg intramuscularly repeated once in 24 hours for 2 doses, or dexamethasone, 6 mg intramuscularly repeated every 12 hours for 4 doses). Participants who had not delivered 1 week after receipt of the single course were randomly assigned to receive either betamethasone, 12 mg intramuscularly repeated once in 24 hours for 2 doses every week until 34 weeks' gestation or delivery, whichever came first (n = 256), or a similarly administered placebo (n = 246). MAIN OUTCOME MEASURE: Composite neonatal morbidity (including severe respiratory distress syndrome, bronchopulmonary dysplasia, severe intraventricular hemorrhage, periventricular leukomalacia, proven sepsis, necrotizing enterocolitis, or perinatal death). RESULTS: Composite morbidity occurred in 22.5% of the weekly-course group vs 28.0% of the single-course group (unadjusted relative risk, 0.80; 95% confidence interval, 0.59-1.10). Neither group assignment nor the number of treatment courses was associated with a reduction in composite morbidity. CONCLUSIONS: Weekly courses of antenatal corticosteroids did not reduce composite neonatal morbidity compared with a single course of treatment. Weekly courses of antenatal corticosteroids should not be routinely prescribed for women at risk of preterm delivery.

Betamethasone↗
PubMed2001

Impaired fatty acid oxidation in propofol infusion syndrome.

Propofol infusion syndrome is a rare but frequently fatal complication in critically ill children given long-term propofol infusions. We describe a child who developed all the clinical features of propofol infusion syndrome and was treated successfully with haemofiltration. Biochemical analysis before haemofiltration showed a large rise in plasma concentrations of malonylcarnitine (3.3 micromol/L) and C5-acylcarnitine (8.4 micromol/L), which returned to normal after recovery. Abnormalities are consistent with specific disruption of fatty-acid oxidation caused by impaired entry of long-chain acylcarnitine esters into the mitochondria and failure of the mitochondrial respiratory chain at complex 11.

Acidosis↗
PubMed2001

Cellular and subcellular patterns of expression of bFGF and CNTF in the normal and light stressed adult rat retina.

This study compared the distributions in the normal and light stressed rat retina of the neuroprotective factors bFGF (basic fibroblast growth factor) and CNTF (ciliary neurotrophic factor). Albino Sprague-Dawley rats were raised in cyclic light and some were exposed to bright continuous light for 48 hr, to induce light damage of photoreceptors. Their retinas were prepared as cryosections, immunolabelled with antibodies to bFGF and CNTF and analysed by confocal microscopy. Both factors were prominent in macroglial cells (astrocytes, Müller cells) and the retinal pigment epithelium (RPE). In the somas of these cells the distributions of the two factors were complementary, with bFGF concentrated in the nuclei and CNTF in the cytoplasm. Both factors were distributed along the processes of macroglial cells, in granular form. CNTF was not detected in neurones, but bFGF was consistently present in the cytoplasm of ganglion cell somas and, in regions of retina subject to stress, in the cytoplasm of photoreceptors. bFGF was not detected in the nuclei or processes of neurones. In retina stressed by light exposure or proximity to the anterior edge of the retina, the levels of bFGF and CNTF were up-regulated, without major changes in localization. Macroglial cells (Müller cells, astrocytes) play a major role in distributing bFGF and CNTF throughout the retina. The different localizations of the two factors within the somas of macroglial, RPE and photoreceptor cells, suggest that their protective actions are exerted by distinctive mechanisms.

Animals↗