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Biomedical subjects

J Williams

Publications and source records attributed to J Williams.

At least 649 records · Page 36Linked to original sources
PubMed1992

Apparent non-mosaic trisomy 16 in chorionic villi: diagnostic dilemma or clinically significant finding?

A case is presented in which apparent non-mosaic trisomy 16 was found in chorionic villi (direct and culture) obtained from a patient undergoing first-trimester prenatal diagnosis. The fetal karyotype subsequently was determined to be 46,XX by follow-up amniocentesis. Serial ultrasonographic examinations revealed placental sonolucencies and intrauterine growth retardation. At 37 weeks, a small-for-gestational-age female was delivered by Caesarean section for fetal distress. Postnatal cytogenetic studies revealed a normal female karyotype in cord blood and mosaic trisomy 16 in placental tissues. These findings suggest that in cases where aneuploidy is confined to placental tissues, it may have biological significance, as evidenced by the apparent placental dysfunction and poor fetal growth in this case.

Adult↗
PubMed1992

Oxygen consumption and mixed venous oxygen saturation monitoring during orthotopic liver transplantation.

Mixed venous oxygen saturation (SvO2) monitoring has been advocated for some critically ill patients. Patients with end-stage hepatic failure have oxygen consumption rates that are lower than normal. Using the Fick equation, oxygen consumption may be calculated if mixed venous and arterial oxygen tensions (and saturations), hemoglobin, and cardiac output are determined simultaneously. This report describes a unique pattern of changes in SvO2 and oxygen consumption in 7 patients undergoing liver transplantation. A previous study correlated plasma carbohydrate (glucose) levels with early hepatic graft survival. After induction, the 7 patients reported here had low oxygen consumption and high SvO2 values. The oxygen consumption rates decreased to the lowest point during the anhepatic phase and rose above baseline by the end of the case. The SvO2 and oxygen consumption data reported here follow the presence of presumed hepatic metabolic activity (increased CO2 and ionized calcium). Further research must be completed to determine whether these measurements indicate early hepatic nonfunction.

Adult↗
PubMed1992

Seroreactivity to HPV-16 proteins in women with early cervical neoplasia.

Although serological reactivity to human papillomavirus type 16 (HPV-16) proteins has been demonstrated in patients with invasive cervical carcinoma, the degree of seroreactivity to these proteins in women with preinvasive disease and its relationship to the HPV type associated with the disease are unclear. We obtained sera from 27 women undergoing cone biopsy for cervical precursor lesions and 22 controls and analyzed seroreactivity by Western blot to fusion proteins containing portions of the HPV-16 E4, L1 and L2 open-reading frames (ORFs). Positives were analyzed by scanning densitometry and intensity values for each case plotted relative to controls. Cervical biopsy specimens from patients were analyzed for HPV-16 nucleic acids by DNA.DNA in situ hybridization. Mean intensity values for seroreactivity to the pATH-E4 protein approached significance (P = 0.058) and a significantly higher proportion of cases vs controls registered values over 4.0 for pATH-E4 (26% vs 4.5%; P = 0.04) and pATH-L2 (48% vs 18%; P = 0.03) proteins. A significantly higher mean intensity value for E4 was observed for cases containing HPV-16 DNA vs HPV-16 negative cases or controls. Thus, seroreactivity to HPV-16-derived proteins may be more common in women with preinvasive cervical disease, and for some protein targets (E4) may indicate a relatively type-specific response.

Antigens, Viral↗
PubMed1992

Tumor necrosis factor in preterm and term labor.

OBJECTIVE: Our objective was to determine if labor (term and preterm) and microbial invasion of the amniotic cavity were associated with changes in amniotic fluid concentrations of tumor necrosis factor. STUDY DESIGN: Amniotic fluid was retrieved by transabdominal amniocentesis from 269 women in the following groups: midtrimester (n = 38), preterm labor with intact membranes (n = 52), preterm premature rupture of membranes (n = 74), term in active labor (n = 84), and term not in labor (n = 21). Fluid was cultured for aerobic and anaerobic bacteria and for Mycoplasma species. Tumor necrosis factor was measured with a commercially available enzyme-linked immunosorbent assay validated for amniotic fluid (sensitivity 60 pg/ml). RESULTS: Amniotic fluid from pregnant women in the second and third trimesters who were not in labor did not contain tumor necrosis factor. Among women in preterm labor, 92.3% (12/13) of patients with a positive amniotic fluid culture had detectable tumor necrosis factor in the amniotic fluid (median 820 pg/ml, range less than 60 to 2340 pg/ml). In contrast, only 10.2% (4/39) of women with a negative amniotic fluid culture had detectable tumor necrosis factor. Histopathologic chorioamnionitis was found in all patients who had a positive amniotic fluid culture, and tumor necrosis factor was detectable in the amniotic fluid of all but one of these patients. Among women in active labor at term, 25% (21/84) had detectable tumor necrosis factor in the amniotic fluid. Tumor necrosis factor was detected more frequently in the amniotic fluid of patients with a positive amniotic fluid culture than in patients with a negative culture (46.6% [7/15] vs 20.2% [14/69], p = 0.047). Amniotic fluid concentrations of tumor necrosis factor were significantly higher in patients with preterm premature rupture of membranes, labor, and a positive amniotic fluid culture than in the other subgroups of patients with preterm premature rupture of membranes. CONCLUSION: Parturition in the setting of microbial invasion of the amniotic cavity is associated with activation of the cytokine network as demonstrated by the detection of tumor necrosis factor in human amniotic fluid.

Adult↗
PubMed1992

12q13 abnormality in rhabdomyosarcoma. A nonrandom occurrence?

We describe two cases of rhabdomyosarcoma with a translocation involving 12q13 as the primary cytogenetic abnormality. Literature review of 35 cases has identified 3 other cases with this abnormality, and we speculate that this may be another nonrandom rearrangement in rhabdomyosarcoma.

Adolescent↗
PubMed1992

Appearance of Ph negative recipient clones in chronic myeloid leukemia patients following bone marrow transplantation.

Seven patients were studied following bone marrow transplantation for chronic myeloid leukemia. Cytogenetic heteromorphisms were used to determine the origin of cells present post-BMT. Differences were found between results from blood and bone marrow samples, and between karyotype and interphase Y-body studies on the same samples. Philadelphia negative (Ph-) hematopoietic chimerism was found in 6 of 7 patients, all of whom had been Ph+ before BMT. One patient also demonstrated hematopoietic chimerism with Ph+ recipient cells following clinical evidence of relapse. In two patients who had received T-cell depleted grafts, cytogenetically rearranged Ph- clones of recipient cells were prominent in PHA-stimulated blood. In one case two clones had appeared only 1 month post BMT. The appearance of these clones so soon after transplant suggests very rapid clonal expansion, or that they were already present pre-BMT but at levels too low to have been detected. In the second patient, clones were not observed until more than 12 months post-BMT, after which four were found. These collectively expanded to occupy an increasing proportion of the total cells. These two patients with clones both remain in good health 44 and 51 months post-BMT. Further studies are needed to determine the true frequency and the significance of such findings.

Adult↗
PubMed1992

Extracellular development, in vitro, of the erythrocytic cycle of Plasmodium falciparum.

One way to explore the nature of the dependence o f intracellular parasites on their host cell is to replace the living host cell with a non-living environment that supports development o f the parasite. Bill Trager, Jonathan Williams and Gokal Gill describe their methods for obtaining extracellulor development of erythrocytic stages of Plasmodium falciparum.

Journal Article↗
PubMed1992

Head, facial, and clavicular trauma as a predictor of cervical-spine injury.

STUDY HYPOTHESIS: The American College of Surgeons teaches that "trauma occurring above the clavicle should raise a high suspicion for a potential cervical spine injury." In this study, we investigated the association of head, facial, and clavicular trauma with cervical-spine and cord injury. METHODS: The records of 5,021 consecutive trauma patients admitted to a level I regional trauma center during a three and one-half year period were reviewed retrospectively. The incidence rates of head, facial, clavicle, cervical spine, and cervical cord injuries were recorded. Glasgow Coma Scores (GCS) were obtained on all patients. Statistical analysis using multiple logistic regression and chi 2 analysis were performed to determine the relationship between traumatic injury above the clavicle and cervical spine and cord injury. RESULTS: Head-injured patients had no greater incidence of cervical-spine injury than did non-head-injured patients (4.76% vs 4.37%, P = .52) but were found to have significantly fewer spinal cord injuries (1.5% vs 2.3%, P = .048). There was no difference in incidence of cervical-spine injuries between patients with and those without facial injuries (4.2% vs 4.6%, P = .61). However, there were significantly fewer cord injuries among patients with facial injuries (0.75% vs 2.2%, P = .01). The presence or absence of clavicular fracture was not associated with a significant increase in cervical spine (6.9% vs 4.4%, P = 11) or cervical cord injuries (1.6% vs 2.0%, P = .68). A GCS of less than 14 was associated with a higher incidence of cervical-spine injury than was a GCS of 14 or more in both head-injured (6.7% vs 3.9%, P = .007) and non-head-injured patients (12.2% vs 5.9%, P = .002). There was a greater incidence of cervical cord injury among patients with a GCS of less than 14 than in those with a GCS of 14 or more in both the head-injured (2.2% vs 1.2%, P = .09) and non-head-injured (8.8% vs 2.7%, P less than .0001) groups. CONCLUSION: Trauma to the head, face, and clavicle is not associated with a higher incidence of cervical-spine or cord injury. Physiologic parameters such as the GCS appear to be more accurate predictors of cervical spine or cord injury than mere evidence of trauma occurring above the clavicle.

Cervical Vertebrae↗
PubMed1992

A high incidence of asthma and respiratory symptoms in 4-11 year old children.

A study assessing the prevalence of respiratory symptoms in two primary schools in Birmingham, U.K. was performed. A questionnaire was delivered to pupils in both schools after which three open days were conducted in one of the schools, where probable asthmatics were identified and referred to their General Practitioner, Chest Clinic or a school asthma clinic. In this school 49% of responders and 52.9% in the control school were symptomless on questionnaire: 31% and 20.8%, respectively, had probable asthma, falling to 20% and 15.5% if a positive response to the question on recent recurrent wheeze was disregarded as indicating asthma. Using the total population as a denominator, the overall asthma prevalence was 20% which is significantly higher compared to previous English rates. Forty-two were seen at the Chest Clinic, 14 being followed for more than two visits. None were on regular anti-asthma treatment initially; 12/14 were taking prophylactic treatment on follow-up. In the two schools, 10.0% and 14.2% of responders were 'chesty' with 'colds' having no other typical asthmatic symptoms: these children should be studied further. This high incidence of respiratory symptoms in primary school children could represent a national trend or just a local increase.

Ambulatory Care Facilities↗
PubMed1992

Concrete operational thought in children with learning disabilities and children with normal achievement.

This study compared Piagetian cognitive development in normal achieving children and two groups of children with learning disabilities designated as either auditory-linguistic or visual-spatial on the basis of Verbal-Performance IQ differences on the Wechsler Intelligence Scale for Children-Revised (WISC-R; 1974). The two groups with learning disabilities were matched with normal achieving controls on intelligence, socioeconomic status, sex, race, and age. Piagetian tasks measuring conservation, seriation, and classification were administered to each child to determine level of operative thought. The auditory-linguistic group scored significantly below normal controls in operativity, and significantly fewer were at a concrete operational level on a conservation of length task than were normal achieving children. The visual-spatial group did not differ significantly from normal controls. These results suggest that auditory-linguistic disabilities may be more detrimental than visual-spatial disabilities to development of operativity.

Achievement↗
PubMed1992

Performance of techniques for measurement of therapeutic drugs in serum. A comparison based on external quality assessment data.

Ten assay techniques were compared using measurements of a range of 15 drugs spiked in freeze-dried samples of serum reported to the Heathcontrol External Quality Assessment Scheme between November 1988 and January 1991. Three measures of performance were studied: frequency of outliers greater than 3 standard deviations from the sample mean, the coefficient of variation (CV) of sample measurements, and the difference of the sample mean from the spike value. The most consistently precise technique was polarisation fluoroimmunoassay (PFIA). It was in the group of techniques producing significantly fewer outliers and lower CVs than other techniques for all its target analytes. However, a specific interaction with the animal serum used as sample matrix resulted in significant negative bias in PFIA measurements of carbamazepine. Other immunoassay techniques and high-performance liquid chromatography also performed well for a range of analytes, in most cases giving less than 6% of outliers with CVs of less than 13% and less than 5% bias. The least satisfactory techniques were nephelometry and gas-liquid chromatography with derivatisation, which for several analytes gave significantly more outliers and higher CV values than other techniques. In samples containing carbamazepine-10, 11-epoxide, immunoassay measurements of carbamazepine showed cross-reactivity with the epoxide metabolite of between 7 and 15%.

Carbamazepine↗
PubMed1992

Anti-inflammatory effects of nedocromil sodium: inhibition of alveolar macrophage function.

The IgE-dependent activation of mononuclear phagocytic cells through their capacity to express low affinity IgE receptors (Fc epsilon RII) has been proposed as a mechanism for the development of airways inflammation in allergic asthma. This Fc epsilon RII expression leads to the IgE-dependent production of the potent pro-inflammatory cytokines IL-1 beta and TNF-alpha. Expression by monocytes of Fc epsilon RII is regulated by several cytokines including interleukin-4, gamma- and alpha-interferons, and granulocyte-macrophage and macrophage colony stimulating factors. An anti-inflammatory effect of nedocromil on monocytes has been proposed as a possible mechanism for its anti-asthma activity. We therefore investigated the capacity of nedocromil to modulate mononuclear phagocyte Fc epsilon RII expression and cytokine production. We used an anti-Fc epsilon RII antibody and flow cytometric analysis to assess the capacity of nedocromil to modulate cytokine-induced Fc epsilon RII expression in normals and asthmatics. Monocytes, THP-1 monocyte leukaemia cells, and alveolar macrophages were exposed to varying concentrations of these cytokines for 48 hr at 37 degrees C with or without the additional presence of nedocromil (1-10 microM) and the per cent of monocytes expressing Fc epsilon RII was determined. No changes in Fc epsilon RII expression were observed. Subsequently, we investigated the capacity of nedocromil to affect the capacity of IgE plus anti-IgE complexes, allergen, and LPS (16 hr/37 degrees C) to stimulate IL-1 beta and IL-6 production. No changes were observed when nedocromil was applied concomitant with the stimulus.(ABSTRACT TRUNCATED AT 250 WORDS)

Anti-Inflammatory Agents, Non-Steroidal↗
PubMed1992

Effects of mood manipulation and anxiety on performance of an emotional Stroop task.

In Study 1 subjects high and low in trait anxiety were asked to identify the colour of anxiety-related, anxiety-matched neutral, happiness-related and happiness-matched neutral words. There were two types of stimulus presentation: blocked trials, where stimuli were blocked with respect to their valence, and mixed trials, where stimuli were mixed with respect to their valence. Subjects high in trait anxiety took longer to identify the colour of anxiety-related compared to matched neutral words for blocked-trial presentation only. In Study 2 subjects were exposed to either a positive or a negative mood-manipulation followed by a mixed-trial Stroop task. The mood manipulation procedure was successful in producing predicted changes in self-reported state anxiety. Analyses showed that high-trait-anxiety subjects exhibited interference effects consistent with the induced mood. No such effects were observed for the low-trait-anxiety subjects.

Adult↗
PubMed1992

Transfer of a dense granule protein of Plasmodium falciparum to the membrane of ring stages and isolation of dense granules.

A 14-kDa protein was localized to the dense granules of Plasmodium falciparum by immunoelectron microscopy with monoclonal antibody 1H1. The protein was present in dense granules in late-stage schizonts and free merozoites. After invasion, the protein was localized exclusively on the membrane of the newly invaded ring. The protein is referred to as RIMA, for ring membrane antigen. The 14-kDa protein was synthesized late in schizogony as determined by immunofluorescence microscopy and immunoblotting. At the late schizont stage it was distributed diffusely throughout the intracellular schizont. Only at the segmenter stage was the protein localized in defined spots that correspond to dense granules. Dense granules were isolated from schizont-infected erythrocytes by subcellular fractionation on a sucrose gradient. Fractions containing the 14-kDa protein were detected by immunoblotting with monoclonal antibody 1H1. The 14-kDa protein was first detected in vesicles at the late (8-nucleus) schizont stage. Mature dense granules sedimented with a peak density of 1.17 g/ml, which is similar to the density of rhoptries isolated by the same procedure.

Animals↗
PubMed1992

Salivary IgA antigliadin antibody as a marker for coeliac disease.

In recent years, serum antibodies to gliadin (AGA) have been reported to be useful markers of coeliac disease. IgA AGA have also been found in intestinal secretions and saliva in coeliac disease and may offer a convenient, non-invasive screening test. In order to test this hypothesis, salivary and serum AGA were measured in children with coeliac disease proved by biopsy and compared with several control groups. Measurement of salivary IgA AGA provided excellent discrimination between those children with coeliac disease and the control groups, and our study suggests that it may provide a rapid, non-invasive method of screening for this disease before intestinal biopsy.

Adolescent↗