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Biomedical subjects

J Price

Publications and source records attributed to J Price.

At least 199 records · Page 11Linked to original sources
PubMed1991

Antithrombin Cambridge II, 384 Ala to Ser. Further evidence of the role of the reactive centre loop in the inhibitory function of the serpins.

Four unrelated individuals have been identified with an identical antithrombin variant, associated in one of them with episodes of recurrent venous thromboses. In each case, the plasma antithrombin concentration was normal and the only function abnormality was a minor but consistent decrease in the heparin-induced thrombin inhibition suggesting a mutation at or near the reactive centre of the molecule. Amplification and direct sequencing of exon 6 showed a G----T mutation at nucleotide 1246, which corresponds to a substitution of a serine for an alanine at residue 384. This is one of a series of conserved alanines that form the stalk to the reactive centre loop. The observed changes in this variant are compatible with recent structural studies that infer that mobility of this stalk with partial re-entry into the A-sheet of the molecule is necessary for optimal inhibitory activity.

Aged↗
PubMed1991

Virus infection triggers insulin-dependent diabetes mellitus in a transgenic model: role of anti-self (virus) immune response.

We investigated the potential association between viruses and insulin-dependent (type 1) diabetes (IDDM) by developing a transgenic mouse model. By inserting into these mice a unique viral protein that was then expressed as a self-antigen in the pancreatic islets of Langerhans, we could study the effect on that expressed antigen alone, or in concert with an induced antiviral (i.e., autoimmune) response manifested later in life in causing IDDM. Our results indicate that a viral gene introduced as early as an animal's egg stage, incorporated into the germline, and expressed in islet cells does not produce tolerance when the host is exposed to the same virus later in life. We observed that the induced anti-self (viral) CTL response leads to selective and progressive damage of beta cells, resulting in IDDM.

Animals↗
PubMed1991

Clustering of dendrites in the cerebral cortex begins in the embryonic cortical plate.

In this study, we have asked what organizational features can be detected in the embryonic rat cerebral cortex. We have found evidence using light microscopy, and scanning and transmission electron microscopy, that soon after the first cortical neurons join the cortical plate, their apical dendrites form clusters. These clusters are characterized by the close apposition of dendritic membranes, and by intermediate-type junctions. Clustering occurs within 24 h of cortical plate formation, at a time when the cortical plate is about six cell diameters thick, and before the cortex has any afferent input or the cortical plate any synapses. Thus the clustering of apical dendrites in the cortical plate appears to be a very early organizational feature in the development of the cerebral cortex.

Animals↗
PubMed1991

Drug abuse screening of childbearing-age women in Alabama public health clinics.

During August 1989, the urine of 5010 women of childbearing-age in Alabama was screened for marijuana, cocaine, opiates, amphetamines, and barbiturates. The data base consisted of 2970 pregnant women, 374 of whom were at high risk, and 2019 nonpregnant women. Our findings included the following information: (1) The statewide prevalence of positive screens for any drugs tested was 12.9% for all women (11.0% for those who were pregnant and 15.6% for those who were not pregnant). (2) There was no difference between urban and rural groups for any drugs tested. (3) Positive marijuana screens were increased among white and nonpregnant women (p less than 0.01). (4) Positive cocaine screens were increased among black and single women (p less than 0.01). (5) More screens were positive in women older than age 20 (p less than 0.01). (6) There was no difference between pregnant and nonpregnant women for positive cocaine screens. (7) No difference existed among the trimesters of pregnancy for positive cocaine screens. (8) Positive screens for marijuana were more frequent in the first trimester of pregnancy than in the second trimester (p = 0.02) or the third trimester (p = 0.001). (9) There was no difference between high-risk and low-risk maternity patients for any drugs tested.

Adult↗
PubMed1991

The generation of neurons and oligodendrocytes from a common precursor cell.

We have used a recombinant retrovirus carrying the lacZ gene to study the developmental potential of precursor cells from the embryonic rat cerebral cortex in dissociated cell culture. Virus was used to label a small number of cultured cells genetically so that their fate could be determined. Infected clones were detected with an anti-beta-galactosidase serum, and the labeled cells were identified using monoclonal antibodies. The results revealed that most precursor cells generated a single cell type, the majority being either neurons or oligodendrocytes. However, a proportion of the neuronal clones also included oligodendrocytes. This proportion increased until embryonic day 16 when 18% of the neuronal clones were of this type. This suggests that during neurogenesis in the cerebral cortex there exists a cell with the potential to generate these two quite different neural cell types.

Animals↗
PubMed1991

Asteroid hyalosis and axial length measurement using automated biometry.

Accurate axial length measurements are needed before intraocular lens implantation in patients with asteroid hyalosis requiring cataract extraction. We suspected that falsely short axial length measurements may be obtained using automated A-scan biometry when we found an automated measurement of 15.90 mm in a patient with severe unilateral asteroid hyalosis. A manual biometry measurement of 21.90 mm was obtained for comparison; this was within 0.2 mm of the manual reading in the opposite uninvolved eye. A case-control study was performed on 20 unilateral asteroid hyalosis subjects using the uninvolved eye as the control, comparing automated biometry and manual A-scan biometry to assess the effect of asteroid hyalosis on automated biometry measurements. Five subjects (25%) with asteroid hyalosis had falsely short axial length measurements of more than 1.00 mm using automated biometry. This would result in more than 2.50 diopters of error in the implanted lens power. This case-control study demonstrates that falsely short axial length measurements may be obtained using automated biometry in patients with asteroid hyalosis, leading to significant error in intraocular lens power calculations.

Aged↗
PubMed1991

Ultrastructure of nasal mast cells in normal subjects and patients with perennial allergic rhinitis.

The ultrastructure of mast cells from the nine normal inferior turbinates were compared with those found in eight patients with perennial allergic rhinitis due to house dust mite allergy. Forty-six mast cells from normal patients were found in forty blocks and eighty cells were found in thirty-three blocks in patients with perennial allergy suggesting an increase of mast cell numbers in perennial allergy. There were no basophils outside the blood vessels and whole mast cells were found only in the submucosa. There was no difference in the morphology of cells of different sizes. Mast cells were more degranulated in the allergic mucosa. Degranulation, irrespective of cell size was found at all depths of the mucosa. A review of the literature covered the in vivo and in vitro descriptions of the ultrastructural morphology of human mast cells in the respiratory tract.

Cell Count↗
PubMed1991

Alcoholic beverage consumption prior to the onset of Wernicke's encephalopathy.

Alcoholic beverage consumption prior to the onset of Wernicke's encephalopathy is shown to be, primarily, full strength beer, although not always in large quantity, by 91% of 80 patients. Secondly, in order of frequency of consumption, was white wine sold in casks and consumed by 30% of patients. These findings have implications when decisions have to be made regarding which alcoholic beverages could be fortified with thiamine as a measure designed to prevent the development of the Wernicke-Korsakoff syndrome.

Journal Article↗
PubMed1991

Neurological complications of alcohol usage.

The relationships between alcohol usage and a number of neurological syndromes are reviewed. These are often complex and incompletely understood. Multiple rather than single factors are the rule rather than the exception. The correct diagnosis may be missed particularly where the aetiological role of alcohol is overlooked. Multiple diagnoses are not uncommon. Issues of differential diagnosis and diagnostic procedures are discussed. Management, including a number of its pitfalls, is outlined.

Journal Article↗
PubMed1991

Asthma: a diagnostic and therapeutic challenge.

Asthma is a disease needing urgent action. Morbidity and mortality are rising, despite advances in our understanding of asthma and in its treatment. The lifetime prevalence of asthma in children varies from 5 to 31%, depending on the defining criteria, and even when recent prevalence (occurring in the past two years) is examined, rates from 5 to 18% have been found. There is growing evidence which shows that signs of reversible airways disease occur in the elderly with even greater frequency and it is likely that at least 10% of the population will need asthma treatment at some stage of their lives; this means that well over five million people in the UK or 250 patients in each 'average' general practice list of 2500 merit the diagnosis of asthma at some stage of their lives. The fact that an average practice is likely to have diagnosed less than half that number clearly implies that asthma is first and foremost an under-diagnosed disease.

Asthma↗
PubMed1991

Fetal cells in the maternal circulation: isolation by multiparameter flow cytometry and confirmation by polymerase chain reaction.

During pregnancy, nucleated fetal erythrocytes enter the maternal circulation and can be isolated efficiently from the maternal cells by multiparameter flow cytometry. Male DNA, implying presence of a male fetus, can be identified in flow-sorted maternal blood by polymerase chain reaction with oligonucleotide primers flanking single-copy Y-specific DNA sequences. Among flow-sorted samples, we correctly identified fetal sex in 17/18 (94%) pregnancies of 10-21 weeks gestation. Maternal blood thus provides a potential opportunity for prenatal diagnosis that could preclude the need for invasive procedures in current use.

Base Sequence↗
PubMed1991

Caecal volvulus in a child: an unusual postoperative complication.

A 2.5 year old dysmorphic child with severe gastro-oesophageal reflux was admitted for elective fundoplication. Three days postoperatively, she developed progressive signs of intestinal obstruction. The diagnosis of caecal volvulus was suggested on the plain radiographic appearance, confirmed at laparotomy and treated by right hemicolectomy. The predisposing factors, diagnosis and approach to surgical management are discussed.

Cecal Diseases↗
PubMed1991

Psychiatric out-patients' reactions to summary letters of their consultations.

The research reported here was an initial attempt to assess the feasibility and utility of providing new referrals to a psychiatric out-patient clinic with written summaries of their consultations. After routine consultations patients were randomly assigned to the experimental group (those sent a summary letter, N = 23) or control group (letter to GP only, N = 29). Subsequent assessment interviews revealed that the summary letters were very well received and patients in the experimental group were significantly more satisfied with their consultations than their control group counterparts. Study findings suggest that such letters offer a practicable option which may provide considerable benefits to patients, their families and referring GPs.

Adolescent↗
PubMed1991

Screening for heparin binding variants of antithrombin.

A chromogenic assay for use as a screening test for the identification of antithrombin deficiency is described. The heparin concentration and the incubation time in the assay were optimised specifically to permit the detection of heparin binding defects of antithrombin. The sensitivity of antithrombin assays for the detection of this type of variant was significantly impaired when an incubation time of more than 30 seconds was used. Several commercially available assays recommend a longer incubation time than 30 seconds and therefore some patients with heparin binding defects of antithrombin may not be identified. The assay described here allows heparin binding variants of antithrombin to be identified and distinguished from other types of antithrombin deficiency in a simple two stage procedure.

Antithrombins↗