PubMed Health⌕ Search

Biomedical subjects

I Wallace

Publications and source records attributed to I Wallace.

15 recordsLinked to original sources
PubMed2005

Are atrial fibrillation guidelines altering management? A community based study.

BACKGROUND AND AIMS: We wanted to determine the prevalence of atrial fibrillation (AF) in a community based cross sectional study in greater Glasgow and how current anti-thrombotic management compares to published guidelines. METHODS: 1466 patients with AF were identified in General Practices in our community and 1008 consented to take part. Their demographic details and medical history were recorded. RESULTS: 1466 patients (mean age 73.4; 55% female) with AF were identified, in our community, giving a prevalence of 1%. 53% of patients were on warfarin therapy. Of those not receiving warfarin, only one third had a putative contra-indication. The proportion ofAF patients on warfarin increased with increasing stroke risk, and over the period of the study. CONCLUSIONS: Prevalence of AF was in keeping with previous estimates. The proportion of patients with AF receiving warfarin therapy appears to be increasing. In the moderate risk group, there was a tendency to use more warfarin in the younger age groups compared to the elderly. It was in the moderate and low risk groups that there was still evidence of deviation from published guidelines.

Aged↗
PubMed2004

No evidence of sleep apnea in children with attention deficit hyperactivity disorder.

Children with attention deficit hyperactivity disorder (ADHD) may have a component of sleep apnea causing arousal and contributing to ADHD behavior during the day. Twenty non-ADHD children between 4 and 16 years of age were compared with 18 children with ADHD with use of nocturnal polysomnography (PSG) and psychometric tests. The psychometric testing confirmed that the control group were normal and that the ADHD children fulfilled the diagnostic criteria for ADHD. The PSG showed normal arousal indexes for the ADHD group (9.8 +/- 3.9/hr) and controls (10.2 +/- 3.1/hr), and normal apnea/hypnea indexes for the ADHD group (1.0 +/- 2.4/hr) and controls (0.6 +/- 0.9/hr). The sleep architecture was not significantly different between groups. There were no sleep abnormalities in the ADHD children that could be responsible for, or contributing to, the disorder.

Adolescent↗
PubMed2003

Superficial siderosis of the central nervous system many years after neurosurgical procedures.

Recurrent haemorrhage into the subarachnoid space causes superficial siderosis, which clinically manifests as cerebellar ataxia, sensorineural hearing loss, and myelopathy. Two patients developed clinical, radiological, and biochemical evidence of superficial siderosis many years after surgery. One had two posterior fossa operations, a left temporal craniectomy, and radiotherapy for a presumed brain tumour before developing clinical evidence of superficial sidersosis 37 years later. The other had small bilateral subdural collections from recurrent shunt revisions following posterior fossa surgery for a Chiari malformation, and then developed deafness and ataxia. The first patient currently has the longest recorded delay between presumed subarachnoid bleeding and clinical manifestations of superficial siderosis. Both patients provide further evidence that superficial siderosis of the central nervous system, a progressive neurodegenerative vascular condition, may be a delayed complication of neurosurgical procedures.

Adult↗
PubMed1997

Patterns of cognitive development in very low birth weight children during the first six years of life.

BACKGROUND: Cognitive development in very low birth weight (VLBW, < or = 1500 g) infants typically has been reported based on mean endpoints in cross-sectional studies. These overall group means mask individual patterns of cognitive development. Given the heterogeneity of VLBW infants, it is important to identify individual patterns of development and the factors associated with the different patterns. OBJECTIVE: We sought to determine individual patterns of cognitive development over the first 6 years in VLBW children and to examine the relative influence of selected biomedical and sociodemographic factors on these patterns. METHOD: VLBW infants (N = 203) were followed from birth to six years. Cognitive scores were obtained at four yearly intervals, and biomedical and social data were obtained beginning with the neonatal period. Cluster analysis was used to identify individual patterns of cognitive development. RESULTS: Five developmental patterns were identified: average-stable (13% of the sample); average-declined to low average (24% of the sample); average-declined to below average (43% of the sample); very low-increased to low average (8% of the sample); and very low-stable (12% of the sample). The patterns could be differentiated by several biomedical factors, including birth weight, gestational age, neonatal health, and 1-year assessments of neurological status and head circumference, as well as by level of maternal education. In particular, abnormal neurological status at 1 year was associated with a pattern of very low stable scores, and a suspicious status was associated with a pattern of improving cognitive development. Maternal education was influential among children born at the upper end of the VLBW range, who had a more favorable set of biomedical factors. CONCLUSIONS: Biomedical factors are of major importance for the cognitive development of VLBW infants, and their influence increases as birth weight declines. Differences in neurological integrity at 1 year were an important indicator of different patterns of cognitive development, especially for infants at the lower end of the VLBW range.

Child Development↗
PubMed1991

A clinical research form for use in the documentation of middle ear effusion.

A form for use in both the clinical and research setting for documenting the presence and course of otitis media with effusion by pneumatic otoscopy has been developed. The form is based on the data obtained in a large Finnish study on pneumatic otoscopy signs and findings at myringotomy (Karma P, Penttilä M, Sipilä M, & Kataja M, Int J Pediatr Otorhinlaryngol 1989). The rationale for development and the clinical and research applications of the form are discussed.

Air↗
PubMed1989

Inverse relationship between HIV-1 p24 antigenemia, anti-p24 antibody and neutralizing antibody response in all stages of HIV-1 infection.

A double blind cohort study was conducted on 149 homosexual males and 36 patients with AIDS to investigate the relationship between HIV-1 antigenemia, the presence of neutralizing antibody (NA) activity and specific anti-viral core protein (p24) antibody (Ab) in the sera of HIV infected individuals during their progression to AIDS. All AIDS patients and 68% (101/149) of the homosexual males were HIV seropositive upon entering the study. Of those 48 (32%) homosexuals who were HIV negative at the onset, three seroconverted during the two year observation period. Retrospective studies of the HIV(-) subjects' sequentially stored serum samples demonstrated an early transient appearance of gag encoded p24 antigen (Ag) which preceded their production of NA and specific anti-p24 Ab. Following their seroconversion, no more circulating p24 Ag could be detected. Among the 101 HIV positive homosexuals, 16% rapidly progressed to AIDS and seven of these 16 (44%) subjects eventually died during the two year observation period. In this group of individuals with poor prognosis, presence of NA and anti-p24 Ab commenced at the onset reaching peak levels just prior to developing AIDS and began to decline as the clinical course worsened. Their circulating level of p24 Ag remained undetectable as long as there was quantifiable NA and anti-p24 Ab in their sera. Reappearance of circulatory p24 Ag, on the other hand, was associated with high risk for progression to AIDS.2+hus, while only 11

Acquired Immunodeficiency Syndrome↗
PubMed1989

The ocular hypotensive effects of demeclocycline, tetracycline and other tetracycline derivatives.

Demeclocycline, tetracycline and other tetracycline derivatives lowered intraocular pressure (IOP) in rabbits following intravitreal injection, but the onset of this effect was not evident until 1 or more days after drug administration. Of the drugs tested, demeclocycline was the most active ocular hypotensive agent. Demeclocycline caused a dose-dependent decrease in IOP. The maximum IOP decrease of approximately 12 mm Hg occurred 5 days after intravitreal administration of 0.5 mg, with the effect persisting for over a week. Demeclocycline did not alter tonographically measured aqueous humor outflow facility or episcleral venous pressure. Based on calculated aqueous humor flow rates following 0.2 mg demeclocycline, a 62% decrease in aqueous humor formation occurred 7 days after intravitreal injection. The flow-to-diffusion ratio for ascorbate was reduced 54% 6 days after the intravitreal administration of demeclocycline, a change also consistent with suppression of aqueous humor formation. Anterior chamber aqueous humor protein concentration was increased 6 days after demeclocycline administration. No histologic changes were present in the treated eyes by light microscopy. Intravitreal demeclocycline similarly lowered IOP in cats, with the duration of effect lasting up to 20 days.

Animals↗
PubMed1988

Effects of systemic desmopressin on aqueous humor dynamics in rabbits.

Intravenous desmopressin, a synthetic antidiuretic hormone, resulted in a dose-dependent increase in intraocular pressure (IOP) in rabbits. IOP was increased 3.6 +/- 0.8 mm Hg 6 hr following injection of desmopressin 200 mUnits/kg with the increase lasting over 10 hr. IOP returned to baseline 24 hr after the injection. Systemic blood pressure, plasma osmolarity and arterial blood gases were not altered by desmopressin. The increased IOP was not associated with alterations in measured outflow facility or episcleral venous pressure. Five hours after desmopressin injection, calculated aqueous humor flow was increased approximately 57%. Aqueous humor ascorbate measurements for calculation of flow to diffusion ratios and anterior chamber fluorophotometry also were consistent with an increased rate of aqueous humor formation as the mechanism for the IOP elevation. Desmopressin administration did not increase aqueous humor protein or aqueous humor cyclic AMP concentration. Systemic pretreatment with indomethacin only partially blocked the IOP increase. Systemic pretreatment with demeclocycline completely blocked the desmopressin-induced increase in IOP.

Animals↗
PubMed1983

The establishment and characterization of a cell line and mouse xenografts from a human malignant melanoma.

A permanent cell line has been established from a human intracranial secondary melanoma. During 3 years of continuous growth in vitro the cells have maintained their characteristic phenotypic properties including melanin production. The cultured cells are highly tumorigenic in the athymic mouse and the tumours produced are histologically identical to the human tumour of origin.

Animals↗
PubMed1981

An investigation in vitro of the exocytosis of lysosomal enzymes from C6 glioma cells.

The rates of exocytosis on the lysosomal hydrolase n-acetyl-beta D-glucosaminidase and beta-glucuronidase were measured in monolayer cultures of the C-6 glioma cell line. A comparison of the kinetics of release of the enzymes and the effects of cytochalasin B suggest that either intralysosomal localisation or the mechanism of release may be different for each enzyme. Evidence was obtained that exocytosis is accompanied by receptor-mediated endocytosis of hydrolases and the importance of the microtubular system in the maintenance of the exocytosis equilibrium was indicated by the effect of colchicine on the rate of extracellular accumulation of the enzymes.

Acetylglucosaminidase↗
PubMed1981

Growth of Peptococcus and Peptostreptococcus: effect of variations of culture media on efficiency of recovery.

Reference strains and clinical isolates of Peptococcus and Peptostreptococcus spp. were evaluated for their growth response in supplemented thioglycolate-yeast extract media. Supplements used included various combinations of hemin, menadione, sodium bicarbonate, and Tween 80. Parallel studies were done to compare the efficiency of recovery of viable cells grown in thioglycolate-based media and Wilkins-Chalgren broth and agar. In addition, the effects of age of the medium and medium storage on viable cell yields for reference strains were determined. Reference strains grown in freshly prepared thioglycolate-yeast extract medium supplemented with sodium bicarbonate produced a 10-fold greater increase in the number of viable cells recovered after 24 h of incubation than did the same organisms cultivated in Wilkins-Chalgren medium. The efficiency of recovery of organisms when either mid-logarithmic- or mid-stationary-phase cells were used to prepare standardized inocula was similar. The results suggest that thioglycolate-yeast extract medium supplemented with sodium bicarbonate is more productive than Wilkins-Chalgren medium for the cultivation of anaerobic gram-positive cocci and may represent a suitable alternative for antimicrobial susceptibility testing of these organisms.

Bicarbonates↗
PubMed1977

Self-control techniques of famous novelists.

A statement by a famous contemporary novelist is presented that indicates how he and others, independently of formal behaviorism, used behavioristic methods-specifically, self-recording charts and regularly scheduled daily work hours-to accelerate and maintain their writing outputs. On the basis of his statement and an analysis of his self-recorded data, it is argued that a meaningful and useful analogy can be drawn between writing a novel and emitting a simple operant response on a fixed-ratio schedule.

Journal Article↗