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Biomedical subjects

M Byrne

Publications and source records attributed to M Byrne.

At least 55 records · Page 3Linked to original sources
PubMed2001

The preparation of additional smears from a cervical scrape: impact on the rate of detection of cervical neoplasia.

The preparation of additional smears from a cervical scrape: impact on the rate of detection of cervical neoplasia It has been known for some time that only a proportion of the cells on the smear-taking device is transferred to the slide. This can give rise to errors in reporting although the smear may have been taken correctly. This study was undertaken to identify a quick and simple method of improving the accuracy of the Papanicolaou test. A conventional smear and five additional smears were obtained from 62 women attending a Genito-Urinary Medicine clinic. The cell content of the conventional smears and the additional smears was compared. Dyskaryotic cells were detected both in the conventional smear and in the first and second additional smears from 22 women. Dyskaryotic cells were detected in the first and second additional smears only in five women. Thus, the conventional smear failed to detect biopsy-confirmed cervical abnormality in these women. A cell count of the first additional smear in the five cases where the conventional smear was negative showed that they contained, on average, 310 dyskaryotic cells. The preparation of one additional cervical smear per cervical scrape could significantly increase the accuracy of the cervical smear test by 11% (P=0.025, McNemar's test).

Adult↗
PubMed2001

Genetic differentiation between mallee and tree forms in the Eucalyptus loxophleba complex.

The Eucalyptus loxophleba complex comprises two tree taxa (E. loxophleba ssp. loxophleba and ssp. supralaevis), two mallee taxa (E. loxophleba ssp. lissophloia and ssp. gratiae), and three rare mallee species, of which one, E. blaxellii, is included in this study. The genetic diversity and phylogenetic relationships between the taxa, particularly in relation to habit, were assessed using anonymous nuclear RFLP loci. The level of diversity in the taxa was high and similar to that detected in other eucalypt species. The populations showed low differentiation at both the subspecies and the species levels. Phylogenetic relationships showed some genetic separation between the tree and mallee habit but no separation of the two taxa within the tree habit or within the mallee habit. The genetic analysis does not support the recognition of E. gratiae as a separate species. The geographically restricted E. blaxellii showed similar levels of diversity to populations of the other widespread taxa of E. loxophleba.

Eucalyptus↗
PubMed2001

Evolution of larval form in the sea star genus Patiriella: conservation and change in the larval nervous system.

The organization of the peptidergic system in the larvae of Patiriella species with divergent ontogenies was compared to determine which aspects of neurogenesis are conserved and which are altered in the evolution of development in these sea stars. P. regularis has ancestral-type feeding bipinnaria and brachiolaria larvae and the organization of the nervous system, in association with feeding structures, paralleled the bilateral larval body plan. P. calcar and P. exigua have non-feeding planktonic and benthic brachiolariae, respectively, and there was no trace of the neuronal architecture involved with feeding. The nervous system in the attachment stage brachiolaria was similar in all three species and neuronal organization reflected larval symmetry. Delayed expression of peptidergic lineages to the brachiolaria stage in the lecithotrophs indicates heterochronic change in the timing of neurogenesis or deletion of the ancestral early neurogenic program. The bipinnarial program is suggested to be a developmental module autonomous from the brachiolar one. With a divergence time of less than 10 Ma, the evolution of development in Patiriella has resulted in extensive reduction in the complexity of the larval nervous system in parallel with simplification in larval form. There is, however, strong conservation in the morphology and neuronal architecture of structures involved with settlement.

Animals↗
PubMed2001

Basis of the superiority of cefoperazone amphotericin teicoplanin for isolating Campylobacter upsaliensis from stools.

The optimum method for isolating Campylobacter upsaliensis from stools has not been clearly defined. In a preliminary study, cefoperazone amphotericin teicoplanin (CAT) selective medium isolated six C. upsaliensis strains which were not detected using modified cefoperazone charcoal deoxycholate (mCCDA). In order to identify the factors that underlie the superiority of CAT over mCCDA for isolating C. upsaliensis, we examined the effect of incubation time and antibiotic content of culture media on the growth of C. upsaliensis isolates using semiquantitative methods. The recovery of a subgroup of C. upsaliensis isolates from seeded stool specimens was also evaluated. Differences in growth of C. upsaliensis on CAT and mCCDA were modest and were not explained by the antibiotic profiles of the two media. Recovery of C. upsaliensis from spiked human feces on CAT was superior to that on mCCDA at lower concentrations of organisms (10(3) CFU/ml). We conclude that although CAT is more suitable than mCCDA for the isolation of C. upsaliensis from stools, the superiority of CAT for detecting this organism is not accounted for by the antibiotic composition of the medium.

Amphotericin B↗
PubMed2001

Recent advances in the design and performance of research assistants.

Every laboratory needs personnel who work 24 hours a day 7 days a week, are efficient, obedient, capable of showing initiative, insightful and affable. Our experience of laboratory workers tells us that there is an immense way to go to achieve these goals. Having tired of the normal, Darwinian approach, a project has been initiated to achieve these ends through genetic technologies.

Humans↗
PubMed2001

Neurodevelopmental indices and the development of psychotic symptoms in subjects at high risk of schizophrenia.

BACKGROUND: Neurological 'soft signs' and minor physical anomalies (MPAs) are reported to be more frequent in patients with schizophrenia than in controls. AIMS: To determine whether these disturbances are genetically mediated, and whether they are central to the genesis of symptoms or epiphenomena. METHOD: We obtained ratings in 152 individuals who were antipsychotic drug-free and at high risk, some of whom had experienced psychotic symptoms, as well as 30 first-episode patients and 35 healthy subjects. RESULTS: MPAs and Neurological Evaluation Scale (NES) 'sensory integration abnormalities' were more frequent in high-risk subjects than in healthy controls, but there were no reliable differences between high-risk subjects with and without psychotic symptoms. MPAs were most frequent in high-risk subjects with least genetic liability and NES scores showed no genetic associations. CONCLUSIONS: The lack of associations with psychotic symptoms and genetic liability to schizophrenia suggests that soft signs and physical anomalies are nonspecific markers of developmental deviance that are not mediated by the gene(s) for schizophrenia.

Abnormalities, Multiple↗
PubMed2001

The morphology of autotomy structures in the sea cucumber Eupentacta quinquesemita before and during evisceration.

Evisceration in the dendrochirotid sea cucumber Eupentacta quinquesemita is a whole-body response involving a predictable series of events including muscle contraction and failure of three autotomy structures: (i) the introvert, the dexterous anterior extensible portion of the body wall, (ii) the tendon linking the pharyngeal retractor muscle to the longitudinal body wall muscle and (iii) the intestine-cloacal junction. The autotomy structures are histologically complex, consisting of muscle, nervous and connective tissue. Autotomy resulted from complete loss in the tensility of the connective tissue ground substance. Separation of the autotomy structures was facilitated by muscle contraction. The cell and tissue changes involved with autotomy were documented by microscopic examination of autotomising tissue. Change in the autotomy structures appears to initiate from the peritoneal side with delamination of the peritoneum followed by a wave of disruption as the connective tissue is infiltrated by coelomic fluid. Evisceration and autotomy in E. quinquesemita are neurally controlled, so particular attention was paid to the fate of neuronal elements. Neurosecretory-like processes containing large dense vesicles and axons were present in the connective tissue layers of the autotomy structures in association with extracellular matrix, muscles and neurons. These neuronal elements remained largely intact during autotomy and did not appear to be a source of factors that effect connective tissue change. They may, however, be involved in muscle activity. Holothuroid autotomy structures are completely or partially bathed in coelomic fluid, so there is potential for hormonal or neurosecretory activity using the coelomic fluid as a conduit. Connective tissue change during evisceration appears to be effected or mediated by an evisceration factor present in coelomic fluid that has a direct transmitter-like or neurosecretory-like mode of operation. The final outcome, expulsion of the viscera, is likely to result from a suite of factors that interact in a manner yet to be determined.

Animals↗
PubMed2001

A review of physical and psychological factors in vulvar vestibulitis syndrome.

This review is based on a MEDLINE search of all papers on vulvar vestibulitis syndrome (VVS) published 1995-2000. The causation, natural history and prevalence of VVS are unknown. There is no convincing evidence that VVS is the result of an infection or of an allergy. It has been proposed that it is an atypical pain syndrome but there is currently no clear evidence that this is so. The usual diagnostic criteria used in VVS are of doubtful discriminative value. Findings from biopsies of women with VVS are inconsistent. While there is some evidence to suggest that women with VVS attending clinics differ psychologically from normal controls, it is not clear whether these differences reflect the effects of VVS, are the result of patient selection or influence the development of the disease. Several treatments, including biofeedback, psychosexual treatment and surgery have been reported to be successful in some patients but there is a lack of proper placebo-controlled trials on which to base estimates of efficacy. There is a vital need for further, high-quality, research in this area.

Humans↗
PubMed2000

Edinburgh high risk study--findings after four years: demographic, attainment and psychopathological issues.

This study reports findings of the Edinburgh High Risk Study four years after it began. This study is designed to explore the pathogenesis of schizophrenia by examining a large sample of young adults aged 16-25 years who are at enhanced risk of developing schizophrenia by having two close relatives with the disorder, and comparing them with matched controls. This paper presents comparisons of the high risk subjects, well controls and subjects with first-episode schizophrenia in terms of demographic, childhood, psychopathological, educational and employment, forensic and social work variables. High risk subjects have more psychological difficulties, poorer educational and employment attainment, and more social work contact than controls. The enhanced social work involvement related to the presence of a schizophrenic parent (especially a mother) but the other difficulties could not be attributed to that situation. Neurotic, partially held psychotic and fully held psychotic symptoms all occurred in both subjects and controls, but all were significantly more common in high risk subjects. Clinical schizophrenia has so far developed in 10 high risk subjects and in no controls. Possible confounding effects of drug or alcohol misuse were considered but were found unlikely to be important.

Adolescent↗
PubMed2000

Predictive model for survival at the conclusion of a damage control laparotomy.

BACKGROUND: We employed modern statistical and data mining methods to model survival based on preoperative and intraoperative parameters for patients undergoing damage control surgery. METHODS: One hundred seventy-four parameters were collected from 68 damage control patients in prehospital, emergency center, operating room, and intensive care unit (ICU) settings. Data were analyzed with logistic regression and data mining. Outcomes were survival and death after the initial operation. RESULTS: Overall mortality was 66.2%. Logistic regression identified pH at initial ICU admission (odds ratio: 4.4) and worst partial thromboplastin time from hospital admission to ICU admission (odds ratio: 9.4) as significant. Data mining selected the same factors, and generated a simple algorithm for patient classification. Model accuracy was 83%. CONCLUSION: Inability to correct pH at the conclusion of initial damage-control laparotomy and the worst PTT can be predictive of death. These factors may be useful to identify patients with a high risk of mortality.

Critical Illness↗
PubMed2000

Neuropsychological change in young people at high risk for schizophrenia: results from the first two neuropsychological assessments of the Edinburgh High Risk Study.

BACKGROUND: Studies of groups of individuals who have a genetically high risk of developing schizophrenia, have found neuropsychological impairments that highlight likely trait markers of the schizophrenic genotype. This paper describes the change in neuropsychological function and associations with psychiatric state of high risk participants during the first two assessments of the Edinburgh High Risk Study. METHODS: Seventy-eight high risk participants and 22 normal controls, age and sex matched completed two neuropsychological assessments 18 months to 2 years apart. The areas of function assessed include intellectual function, executive function, learning and memory, and verbal ability and language. RESULTS: The high risk participants performed significantly worse on particular tests of verbal memory and executive function over the two assessments than matched controls. Those high risk participants who experienced psychotic symptoms were found to exhibit a decline in IQ and perform worse on tests of verbal memory and executive function than those without symptoms. An increase in psychotic symptoms between the two assessments in the high risk group was found to be associated with an apparent decline in IQ and memory. CONCLUSIONS: The results suggest that the development of psychotic symptoms is preceded by a decline in IQ and memory. This may reflect a general and a more specific disease process respectively.

Adolescent↗
PubMed2000

Randomized comparison of unfractionated heparin with corticosteroids in severe active inflammatory bowel disease.

BACKGROUND: Heparin therapy may be effective in steroid resistant inflammatory bowel disease. AIM: A randomized pilot study, to compare unfractionated heparin as a first-line therapy with corticosteroids in colonic inflammatory bowel disease. METHODS: Twenty patients with severe inflammatory bowel disease (ulcerative colitis, n=17; Crohn's colitis, n=3) were randomized to either intravenous heparin for 5 days, followed by subcutaneous heparin for 5 weeks (n=8), or high-dose intravenous hydrocortisone for 5 days followed by oral prednisolone 40 mg daily, reducing by 5 mg per day each week (n=12). After 5 days, non-responders in each treatment group were commenced on combination therapy. Response to therapy was monitored by: clinical disease activity (ulcerative colitis: Truelove and Witt Index; Crohn's colitis: Harvey and Bradshaw Index), stool frequency, serum C-reactive protein and alpha1 acid glycoprotein, endoscopic and histopathological grading. RESULTS: The response rates were similar in both treatment groups: clinical activity index (heparin vs. steroid; 75% vs. 67%; P=0.23), stool frequency (75% vs. 67%; P=0.61), endoscopic (75% vs. 67%; P=0.4) and histopathological grading (63% vs. 50%; P=0.67). Both treatments were well-tolerated with no serious adverse events. CONCLUSION: Heparin as a first line therapy is as effective as corticosteroids in the treatment of colonic inflammatory bowel disease. Large multicentre randomized comparative studies are required to determine the role of heparin in the management of inflammatory bowel disease.

Administration, Oral↗
PubMed2000

High responding factor VIII inhibitors in mild haemophilia - is there a link with recent changes in clinical practice?

The development of high responding inhibitors is an increasingly recognized complication of mild Haemophilia. Inhibitors tend to develop in adolescence and adulthood and this is frequently preceded by high-intensity factor replacement therapy. We report two patients with mild Haemophilia who developed high responding inhibitors after continuous infusion with recombinant factor VIII (Kogenate) as prophylaxis for surgery. We discuss whether recent changes in clinical practice could be responsible for the apparent increase in high responding inhibitors in mild Haemophilia.

Adult↗
PubMed2000

Lipid dynamics in the embryos of Patiriella species (Asteroidea) with divergent modes of development.

Evolution of lecithotrophic development in sea stars involved a modification in maternal provisioning from the production of yolk-dominated to lipid-dominated eggs. The dynamics of lipid reserves in the embryos of four Patiriella species differing in their lipid provisions were examined. Patiriella regularis had small yolk protein-dominated eggs (150 microm in diameter) and an ancestral mode of development through planktotrophic larvae. Patiriella calcar, Patiriella exigua and Patiriella pseudoexigua had large eggs (390-440 microm in diameter) and lecithotrophic planktonic, benthic and intragonadal larvae, respectively. Patiriella exigua deposited negatively buoyant eggs containing substantial yolk protein and lipid reserves onto the substratum. In contrast, the planktonic eggs of P. calcar and the intragonadal eggs of P. pseudoexigua were dominated by lipid and were neutrally and positively buoyant, respectively. By the blastula stage there was little trace of lipid in P. regularis embryos. Blastulae of the lecithotrophic developers, by contrast, had conspicuous lipid droplets distributed through their cells. In parallel with the change from cuboidal to columnar epithelium during the blastula to gastrula transition, lipid reserves became redistributed into the basal cytoplasm. The extent of lipid transport reflected the amount of lipid reserves. In P. pseudoexigua embryos with the greatest lipid load, basal shunting was followed by secretion of lipid into the blastocoele where it was stored for the perimetamorphic period. Evolution of lecithotrophy in Patiriella appears to reflect selection to provide metamorphic stages with nutrients normally accrued by feeding larvae with the consequence that early development is burdened by voluminous, potentially inert nutritive stores. Lipid redistribution coincident with a major developmental stage transition may be required to facilitate unimpeded morphogenesis. This phenomenon may be characteristic of lecithotrophic development in echinoderms and appears pre-adaptive for extrusion of lipid in species like P. pseudoexigua with particularly extensive lipid reserves.

Animals↗
PubMed2000

Labour and delivery complications at birth and later mania. An Irish case register study.

BACKGROUND: Several reports postulate that manic depression and schizophrenia share environmental risk factors. Although obstetric adversity has been suggested as a risk factor for schizophrenia, few studies have examined its relationship to bipolar affective disorder. AIMS: To assess the rate of obstetric complications incurred by patients with mania compared with controls. METHOD: From the Dublin Psychiatric Case Register we identified individuals with a discharge diagnosis of mania and traced their birth records. Each case was matched with a control of the same gender, born in the same hospital, in the same year, matched for maternal age, parity and social class. Two obstetric complications scales were used to make blind evaluations of labour and delivery data. RESULTS: Patients with mania did not experience a greater frequency or severity of labour and delivery complications than their matched controls. Rates of obstetric adversity were unrelated to the presence or absence of family history of psychiatric disorder. Obstetric adversity was unrelated to the age at first diagnosis. CONCLUSIONS: These findings suggest that obstetric adversity is not a risk factor for later mania.

Bipolar Disorder↗
PubMed2000

Labour and delivery complications and schizophrenia. Case-control study using contemporaneous labour ward records.

BACKGROUND: Controversy continues regarding an association between obstetric complications and risk of schizophrenia in early adult life. AIMS: To compare the rate of labour and delivery complications among persons who developed schizophrenia with controls; to establish whether any complication is associated with later schizophrenia. METHOD: We located the labour ward records of 431 individuals with schizophrenia and of same-gender controls from the same hospital birth series. Mothers were matched by age, socio-economic group and parity. Individual complications were evaluated blindly using two obstetric complication scales. RESULTS: Overall, the rate of labour and delivery complications for those who developed schizophrenia did not differ from that of controls. Males who had presented to psychiatric services before the age of 30 had a greater frequency of and more severe labour/delivery complications than their matched controls. CONCLUSIONS: Other than among young-onset males we found no increase in labour and delivery complications among cases.

Case-Control Studies↗
PubMed2000

Vestigial ophiopluteal structures in the lecithotrophic larvae of Ophionereis schayeri (Ophiuroidea).

Evolution of echinoderm development from a feeding to a non-feeding mode can be examined by studying non-feeding larvae with structures that appear to be vestiges derived from a feeding ancestral state. The lecithotrophic larvae of the Australian brittle star Ophionereis schayeri possess such features, and the early development of this species was documented by light and scanning electron microscopy. The embryos undergo irregular cleavage, resulting in the formation of different sized blastomeres, with subsequent development through a wrinkled blastula stage. The lecithotrophic larva of O. schayeri possesses several vestigial ophiopluteal structures, including a continuous ciliated band, a larval gut, and a larval skeleton. The ciliated band is a reduced expression of the continuous ciliated band typical of ophioplutei. The larval gut is a transiently complete system, but an esophageal plug and rapid closure of the blastopore renders it nonfunctional. The larval skeleton, though reduced, consists of four rods corresponding to the body, posterolateral, anterolateral, and postoral rods characteristic of an ophiopluteus. Due to a heterochrony in larval skeletogenesis, the postoral rods develop early and simultaneously with the other rods. Compared with the larvae of other lecithotrophic ophiuroids, the larva of O. schayeri is one of the most reduced ophiopluteal forms reported to date.

Animals↗