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Biomedical subjects

D Fraser

Publications and source records attributed to D Fraser.

At least 91 records · Page 5Linked to original sources
PubMed1997

Stereotactic biopsy of nonpolar tumors in the dominant hemisphere: a prospective study of effects on language functions.

A prospective study of patients undergoing computerized tomography (CT)-guided stereotactic biopsy of nonpolar tumors in the dominant hemisphere was undertaken to determine if stereotactic biopsy caused a deterioration of language functions. Language was assessed using the Western Aphasia Battery (WAB) and the Boston Naming Test (BNT) before and after a biopsy sample was obtained. Of 16 patients studied, five (31%) were dysphasic preoperatively. After the biopsy the Aphasia Quotient (AQ), derived from the WAB, had significantly deteriorated in four (80%) of these patients, whereas in the fifth it remained relatively unchanged. One of these patients with an extensive infiltrating hemispheric oligoastrocytoma subsequently recovered normal language function after radiotherapy. In 10 of the 11 patients who had normal language function preoperatively there were no deleterious changes after biopsy in either the WAB subtest or BNT scores. In the other patient whose WAB score was normal preoperatively, there was a significant deterioration in postoperative AQ. This patient, who declined steroid therapy before and after biopsy, had a glioblastoma multiforme in Wernicke's area. A postoperative CT scan revealed no changes from what was shown on preoperative scan. This clinical study shows that CT-guided stereotactic biopsy of nonpolar tumors in the dominant hemisphere using the Brown-Roberts-Wells system and the Sedan-Nashold biopsy cannula carries a 9% risk (95% confidence intervals 0-26%) of impairing language functions if the patient is not dysphasic preoperatively. If the patient is dysphasic preoperatively, there is a very high risk of aggravating the dysphasia with stereotactic biopsy.

Adult↗
PubMed1997

Natural history of Giardia lamblia and Cryptosporidium infections in a cohort of Israeli Bedouin infants: a study of a population in transition.

The natural history of Giardia lamblia and Cryptosporidium infections were determined in a cohort of 164 Bedouin children, from a population not previously studied, which is in transition from nomadism to a settled life style. Stools were sampled monthly from birth to two years of age and at all diarrhea episodes. The risk of infection with G. lamblia and Cryptosporidium infection by age two was 91.5% and 48.8%, respectively. Cryptosporidium prevalence was 3-4% at all ages, whereas G. lamblia prevalence was > 30% after age one. Giardia lamblia and Cryptosporidium asymptomatic detection rates were high, 28.5% and 1.6%, respectively. Detection of G. lamblia was higher in diarrhea episode samples obtained before six months of age, but after that age and overall, the detection was lower than in nondiarrhea samples (odds ratio [OR] = 0.8, 95% confidence interval [CI] = 0.7-0.9, P < 0.05). Detection rates of C. parvum were higher in episode-related samples in all age groups (OR = 2.8, 95% CI = 1.9-4.2, P < 0.05) and infections in boys were more frequently symptomatic than in girls. While G. lamblia does not appear to be a consistent pathogen in this population where it is hyperendemic, Cryptosporidium has been shown to be an important cause of diarrhea in young children in the community.

Adolescent↗
PubMed1997

The utility of the Right Hemisphere Language Battery in patients with brain tumours.

The Right Hemisphere Language Battery (RHLB) (Bryan, 1989) was devised to assess the presence of language disorders in patients with damage to the right cerebral hemisphere and to permit an evaluation of the efficacy of therapeutic techniques. To evaluate the utility and sensitivity of the RHLB in patients with solitary right hemispheric brain tumours 20 patients were assessed before and after neurosurgery. Twenty control subjects with no signs or symptoms of brain disease who were undergoing lumbar spinal surgery were also assessed. On six of the seven RHLB subtests there was no significant difference between the scores obtained preoperatively by patients with right hemispheric brain tumours and the control subjects. There was also no significant change in the scores of the patients with tumours before and after resection of the lesion. The RHLB is therefore not recommended for either evaluating communication deficits or for measuring the efficacy of therapeutic techniques in patients with right hemisphere brain tumours. This study does, however, show that there are statistically significant differences between the control and brain tumour groups on the discourse analysis subtest preoperatively. The implications of the study are discussed together with possible reasons for the findings.

Adult↗
PubMed1996

Normal parathyroid hormone responsiveness of bone-derived cells from a patient with pseudohypoparathyroidism.

Pseudohypoparathyroidism (PHP) is characterized by a lack of response to parathyroid hormone (PTH); however, normal skeletal responsiveness to PTH in some patients with PHP type Ia was previously suggested on the basis of clinical observations. To test this hypothesis, we measured cyclic adenosine monophosphate (cAMP) production in response to various agonists in bone-derived osteoblast-like (OBL) cells from trabecular explants obtained from an iliac crest biopsy of a 25-year-old woman with PHP. The patient was proved to have PHP type Ia on the basis of Albright's hereditary osteodystrophy and decreased activity of stimulatory guanine nucleotide-binding protein (Gs) in erythrocytes. Responsiveness of the patient's OBL cells was compared with OBL cells from eight subjects aged 18-39 years who had no evidence of metabolic bone disease. OBL cells from the patient responded to the following agonists (expressed in multiples of elevation of cAMP, stimulated/basal, mean +/- SE, n = 3): PTH, 3.8 +/- 0.3; forskolin, 8.2 +/- 0.2; and cholera toxin, 56.8 +/- 10.0. These responses were not significantly different from those of control OBL cells: PTH, 4.5 +/- 1.1 (range 2.4-7.5); forskolin, 7.7 +/- 1.4; and cholera toxin, 57.9 +/- 16.2. The normal cholera toxin response indicated the presence of functional Gs. Bone cells from patients with PHP type Ia may exhibit a normal PTH receptor-coupled adenylyl cyclase system in vitro despite clinical evidence of impaired hormone-responsive adenylyl cyclase in other tissues, including the kidney. Skeletal responsiveness to PTH may explain the long periods of spontaneous normocalcemia observed in this patient.

Adenylyl Cyclases↗
PubMed1995

Breech presentation and cesarean section in term nulliparous women.

OBJECTIVE: To examine pregnancy outcome in nulliparous women with single term breech presentation. METHODS: Two departments of Obstetrics and Gynecology at the same hospital used different approaches to deliver nulliparous women with singleton breech presentation at term. One department (A) delivered by trial of labor and the other (B) delivered by elective cesarean section. Prospectively and blinded to obstetric condition, parturients were assigned to either department in a systematic alternate fashion. The study period covered 8 years (1985-1992). The pregnancy outcome parameters examined were: Apgar score, intra- and post-partum death and maternal and neonatal morbidity. Neonatal morbidity was classified in three major categories: non-neurological trauma, neurological signs and respiratory problems. RESULTS: The study included 264 women of whom 135 delivered in department A and 129 in department B. Department A had 35 vaginal and 100 cesarean births and department B 10 vaginal and 119 cesarean births. There was no intra-partum death and the only post-partum death occurred among vaginal deliveries. The Apgar score was significantly worse at 1 and 5 min in vaginally delivered babies of department B. Neonatal morbidity was significantly more frequent after vaginal births (P < 0.01). Maternal morbidity was significantly higher following cesarean sections (P < 0.01). Babies of vaginal deliveries had significantly higher non-neurological trauma (P < 0.01) and pathological neurological signs (P < 0.01) than those delivered by the abdominal route. CONCLUSION: The level of risk for mother and child in the nulliparous with term singleton breech, suggests cesarean section as the preferred route of delivery.

Adult↗
PubMed1995

One or multiple previous cesarean sections are associated with similar increased frequency of placenta previa.

OBJECTIVE: The purpose of this study was to determine whether multiple previous cesarean sections would be associated with a higher frequency of placenta previa in subsequent deliveries than in women with only one previous cesarean section. STUDY DESIGN: Data of all pregnant women and deliveries were obtained from the computerized records of our department for the period 1985-1992. The study group included symptomatic placenta previa diagnosed by real time ultrasound or during labor. The data included maternal age, gravidity, parity and previous cesarean sections. Nulliparous women were excluded from the study. RESULTS: There were 58,633 deliveries during the study period, including 284 patients with placenta previa (0.48%). Increasing maternal age was associated with a higher frequency of placenta previa. Similar results were found with increasing parity. A more significant trend was found with increasing number of previous abortions. Among placenta previa deliveries 21.1% of patients had previous cesarean section, and among normal deliveries only 10.9% had previous cesarean section (P < 0.0001). The frequency of placenta previa in women with previous normal deliveries was 0.79/1000; in women with one previous cesarean section 15.39/1000; with two previous cesarean section 13.91/1000; with three previous cesarean sections 10.37/1000. While the difference between none and one previous cesarean sections was highly significant (P < 0.0001), the difference between one and more cesarean sections was not significant. CONCLUSION: Although the rate of placenta previa was significantly lower among deliveries without previous cesarean section in comparison with deliveries with one previous cesarean section, this difference was not enhanced with the increasing number of previous cesarean sections.

Adult↗
PubMed1995

Hypertensive disorders in twin pregnancies.

This study investigates the influence of hypertensive disorders on twin pregnancies for an unselected, population-based series. Between 1986 and 1991, out of a total of 56,381, 766 (1.3%) were twin deliveries at our institution, the only tertiary care hospital serving a population of about 400,000 inhabitants. The incidence of hypertensive disorders was significantly higher in twin gestations than in singleton pregnancies, at 3437/55,615 (6.2%) vs 85/766 (11.1%) (p < 0.001, OR = 1.8, 95% CI = 1.4-2.3). Hypertensive disorders were significantly higher in twin as compared to singleton pregnancies, regardless of parity, and even after adjusting for maternal age. More instrumental or surgical deliveries were needed when pregnancies were complicated by hypertension, in twin as well as singleton gestations. Despite the association between prematurity and hypertensive disorders, and prematurity and perinatal mortality, no significant difference was found in perinatal mortality between hypertensive and normotensive twin pregnancies. The neonatal death-rate in normotensive and hypertensive twin pregnancies (3.7% and 3.5% respectively) was higher than that of stillbirths (respectively 2.3% and 0%).

Delivery, Obstetric↗
PubMed1995

Generating a culture focused on continuous improvement.

Describes the principles and values on which the North Ayrshire & Arran NHS Trust was established. Presents the reasons for choosing a culture focused on quality together with the clinical and service development generated by continuous improvement.

Communication↗
PubMed1995

Cerebral venous sinus thrombosis and antiphospholipid antibodies.

We report two cases of cerebral venous sinus thrombosis associated with an antibody to phospholipids, namely the lupus anticoagulant. Both patients later developed further immunologically mediated conditions. The importance of screening for the lupus anticoagulant in addition to anticardiolipin antibodies in this condition and the need for follow-up of such patients is discussed.

Adult↗
PubMed1995

Evaluation of an enzyme immunoassay for the detection of Cryptosporidium spp. in stool specimens from infants and young children in field studies.

Diagnosis of Cryptosporidium is made by the identification of oocysts in stool specimens. Screening in field studies relies mainly on acid-fast staining followed by microscopic examination. The more sensitive immunofluorescent antibody (IFA) staining method is time-consuming, may involve technical difficulties, and is extremely costly as a screening procedure in field studies. We evaluated the diagnostic utility of a commercially available enzyme immunoassay (EIA), which detects Cryptosporidium-specific antigen, in 204 unprocessed stool specimens obtained from patients less than three years of age from a field study in southern Israel. When compared with the routine screening procedure applied in this field study (screening by acid-fast staining and microscopy after concentration, and confirmation of positive results by IFA), both the sensitivity and specificity were 98%. Of 139 specimens negative by microscopy, 13 (9.3%) were positive by the EIA. Eleven of these were confirmed by inhibition with antibody to Cryptosporidia-specific antigen. The EIA is an important tool for identifying Cryptosporidium in fecal specimens in field studies since it is sensitive, specific, simple to use, and unaffected by the presence of a preservative.

Animals↗
PubMed1995

Biosensor markets: opportunities and obstacles.

Currently, glucose sensing for the control of diabetes is the only high-volume market for biosensors. Yet, a variety of lower-volume niches are available for exploitation in medical diagnostics and the pharmaceutical and other industries. There are problems waiting for biosensor solutions, but the balance between market opportunities and technical and/or financial obstacles will control the future expansion of biosensor technology.

Biosensing Techniques↗
PubMed1995

Biosensors in critical care.

Electrochemical bio/chemosensors are ideally suited to critical care situations. Factors such as fast response, portability, minimal sample preparation, and lack of need for highly trained staff reduce the time between testing and therapeutic decision. In addition, the accuracy of these devices approaches that of more traditional laboratory-based clinical analysers.

Biosensing Techniques↗
PubMed1995

Optical biosensors. A bright future.

Progress in fibre-optic technology, laser miniaturization, and the reproducible manufacture of prisms and wave guides has made the commercial exploitation of optical biosensors possible. Some optical biosensors are miniaturized versions of traditional spectrophotometers, others are based on new integrated-optic methods. This article reviews the achievements already made in this area and the opportunities for the future.

Biosensing Techniques↗
PubMed1994

Identification and chromosomal localization of a DNA fragment implicated in the partial correction of the Fanconi anemia group D cellular defect.

Fanconi anemia (FA) cells, complementation group D, which had been transfected with mouse genomic DNA were partially corrected for their mitomycin C (MMC) hypersensitivity. A genomic DNA fragment which complements the resistance of FA(D) cells to MMC close to normal level has been cloned; it has no correcting activity in FA group A cells. It contains two highly conserved regions between the mouse and human genome, which flank mouse repeated DNA. This DNA fragment detects a 3.6-4-kb mRNA transcript in human cells. Moreover this fragment maps to chromosome 11q23, a region of particular interest since several genes involved in the control of major cellular functions are located in this area. This DNA fragment may belong to a gene directly or indirectly involved in FA(D) function.

Animals↗
PubMed1994

Gestational diabetes among Bedouins in southern Israel: comparison of prevalence and neonatal outcomes with the Jewish population.

Differences in the prevalence of gestational diabetes mellitus (GDM) have recently been reported between various ethnic populations. In the Negev region of Israel, a universal free screening programme for GDM was implemented in 1985. Between 1 March 1987 and 31 July 1988 11,003 deliveries occurred at the Soroka Medical Center, which provides free delivery and postnatal care to the whole Jewish and Bedouin population of the region. GDM was found in 5.7% of Jewish and in 2.4% of Bedouin women (odds ratio, 2.3, 95% confidence interval (CI) 1.8-2.9; P < 0.0001). Ethnicity was unrelated to maternal outcome, perinatal mortality or to any of the examined morbidity conditions of the newborn. The incidence of major congenital malformations was significantly higher in Jewish than in Bedouin infants of GDM women (Fisher's Exact Test, P < 0.03). Conversely, Jewish infants had fewer minor congenital anomalies (odds ratio 0.26, 95% CI 0.09-0.73). In a multivariate logistic regression model, gestational age, mode of delivery and insulin requirement during pregnancy were the only factors independently associated with neonatal morbidity. The results of this study suggest that in our health care system, among women with GDM ethnicity is not associated with an excess of unfavourable maternal or infant outcomes.

Adult↗