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Biomedical subjects

M Berry

Publications and source records attributed to M Berry.

At least 37 records · Page 2Linked to original sources
PubMed1999

[Retrospective study of exchange transfusion for newborn infants with reconstituted blood. Review of 60 exchanges].

PURPOSE: The necessity of saving blood products has established the practice of exchange transfusion (ET) with reconstituted blood in newborns. The aim of this retrospective study was to evaluate the indications and the practice of this technique at the Perinatal Hemobiology Centre (Paris, France). METHODS: The records of intervention allowed us to review the etiologic categories for neonates having undergone exchange transfusion with reconstituted blood, the dosages used (bilirubin, hemoglobin), and the other main parameters of ET. RESULTS: Sixty ETs were performed in 48 newborns between the 1st July 1996 and the 1st July 1998. Twenty-seven with Rh hemolytic disease had 39 ETs (19 for hyperbilirubinemia, 12 for anemia, and eight for both), whereas ten out of 12 repeated ETs were indicated for hyperbilirubinemia (six of these cases were in newborns weighing > or = 2500 g and after a volume exchange < or = 1 blood mass [range 0.72-1.0] at the last ET). Twenty-one cases showed other diseases: six of them had anemia, nine had hyperbilirubinemia, and seven showed disseminated coagulopathy. The tolerance of ET was poor in 24% infants in this group. CONCLUSIONS: The volume of 1.3 blood mass for ET is sufficient for the majority of cases with hyperbilirubinemia, allowing transfusional savings in comparison with the previous recommendation of two blood volumes. Exact labeling of the content of units of packed red cells and plasma is essential to fulfill the volume and hematocrit requirements in every case.

Anemia↗
PubMed1999

Optic nerve regeneration after intravitreal peripheral nerve implants: trajectories of axons regrowing through the optic chiasm into the optic tracts.

We have studied axon regeneration through the optic chiasm of adult rats 30 days after prechiasmatic intracranial optic nerve crush and serial intravitreal sciatic nerve grafting on day 0 and 14 post-lesion. The experiments comprised three groups of treated rats and three groups of controls. All treated animals received intravitreal grafts either into the left eye after both left sided (unilateral) and bilateral optic nerve transection, or into both eyes after bilateral optic nerve transection. Control eyes were all sham grafted on day 0 and 14 post-lesion, and the optic nerves either unlesioned, or crushed unilaterally or bilaterally. No regeneration through the chiasm was seen in any of the lesioned control optic nerves. In all experimental groups, large numbers of axons regenerated across the optic nerve lesions ipsilateral to the grafted eyes, traversed the short distal segment of the optic nerve and invaded the chiasm without deflection. Regeneration was correlated with the absence of the mesodermal components in the scar. In all cases, axon regrowth through the chiasm appeared to establish a major crossed and a minor uncrossed projection into both optic tracts, with some aberrant growth into the contralateral optic nerve. Axons preferentially regenerated within the degenerating trajectories from their own eye, through fragmented myelin and axonal debris, and reactive astrocytes, oligodendrocytes, microglia and macrophages. In bilaterally lesioned animals, no regeneration was detected in the optic nerve of the unimplanted eye. Although astrocytes became reactive and their processes proliferated, the architecture of their intrafascicular processes was little perturbed after optic nerve transection within either the distal optic nerve segment or the chiasm. The re-establishment of a comparatively normal pattern of passage through the chiasm by regenerating axons in the adult might therefore be organised by this relatively immutable scaffold of astrocyte processes. Binocular interactions between regenerating axons from both nerves (after bilateral optic nerve transection and intravitreal grafting), and between regenerating axons and the intact transchiasmatic projections from the unlesioned eye (after unilateral optic nerve lesions and after ipsilateral grafting) may not be important in establishing the divergent trajectories, since regenerating axons behave similarly in the presence and absence of an intact projection from the other eye.

Age Factors↗
PubMed1999

Pelvi-calyceal cast formation following silver nitrate treatment for chyluria.

A case of chyluria is reported in which anuria followed instillation of 3% silver nitrate into the collecting system of both kidneys, with unusual radiographic features. Plain radiographic, ultrasound and computed tomographic findings are discussed. To the best of the authors' knowledge this has not been previously described in the literature.

Adult↗
PubMed1999

Faculty of Radiation Oncology survey of work practices.

The aim of the present paper was to determine the current working conditions of practising radiation oncologists (RO) in Australasia and their attitudes towards their work and work environment. The authors were requested by the Faculty of Radiation Oncology to conduct a survey of Fellows' work conditions and attitudes. The need for such a survey arose from a workshop of the Faculty held in Sydney in 1995, to determine future directions of the Faculty. Issues of potential interest were identified at the workshop and supplemented by the authors into a survey consisting of both directed and open questions. Respondents were free to remain anonymous. An address list of RO was supplied by the Royal Australian and New Zealand College of Radiologists (RANZCR). Two mailouts were performed to increase the response rate. The survey was completed during the second half of 1996 and analysed in 1997. The response rate was 79% (63-100% according to state/country). The age range was 30-69 years (median: 43 years; mean: 44 years), and 78% of the respondents were male. A public centre was identified as the sole or main place of work for 84% of respondents. The number of RO per practice varied from one to 25 (median: 5). The estimated hours worked per week ranged from 20 to 79 (mean: 52 h; median: 50 h). There were significant differences in allocation of hours between public and private (more clinical hours for private (P = 0.008), more teaching hours for public (P = 0.007)) but no difference in total hours. The responses for clinical work profile were: 'general' 39%, 'largely subspecialty' 37% and both 2% (23% did not respond). The proportion whose practice was 'largely subspecialty' differed between public and private (53% vs 13%, respectively; P = 0.06), and varied according to the number of RO in the practice (62% for > five RO vs 35% for < or = five RO, P = 0.03). The need for subspecialization for the treatment of common tumours (breast, gynaecological etc.) was held by 78% of respondents and was related to the number of RO in the practice (100% for > five RO vs 81% for < or = five RO, P = 0.002). The number of new patients seen per RO in 1995 ranged from 0 to 700 (mean: 342; median: 350), with a significant difference between the mean numbers seen in public versus private settings (331 vs 409, respectively; P = 0.008). Administration of cytotoxics was supervised by 36% of RO across Australasia but was dependent strongly on the state/country of practice (P = 0.0002). The current and preferred roles in clinical management were scored as means of 7.9 and 8.7, respectively, on a linear scale from 1 (mainly technical role) to 10 (significant role in overall management). A total of 40% of RO were content with their current time allocation; the remainder generally wished to reduce clinical time and increase self-education and/or clinical research. Most indicated that they wanted some 'protected time'. Most were content to be called a 'radiation oncologist' and wished to retain this title; the most common alternative was 'clinical oncologist'. Much of the general comment related to perceived loss of control of clinical and academic aspects of oncology to other specialties. The present survey is the first to define current work practices and to explore attitudes to work. It is clear that many RO consider clinical workloads to be excessive, to the exclusion of other work-related activities. There was a strong feeling that significant changes will be required if RO are to maintain the role in cancer management for which they are trained.

Adult↗
PubMed1999

Magnetic resonance evaluation of idiopathic scoliosis: a prospective study.

The objective of the present study was to determine the incidence of unsuspected intraspinal pathology and to assess the value of atypical clinical features as predictors of these intraspinal pathologies, in patients with idiopathic scoliosis. Twenty-five consecutive patients (13 boys, 12 girls) with idiopathic scoliosis were prospectively evaluated with MRI. Magnetic resonance imaging detected intraspinal pathology in seven patients (28%), which included syringohydromyelia with Chiari I malformation (n = 5), and syringomyelia and dumb-bell neurofibromas in one patient each, respectively. Dural ectasia was also present in five patients. Atypical features, described in the literature as pointers to intraspinal pathologies such as the age < 11 years at presentation, presence of pain, hyperkyphosis, severe curves and the presence of the left thoracic or thoracolumbar curves, were seen to be equally distributed between the two groups (those with and without intraspinal pathologies), thus raising doubts about the importance of these features.

Adolescent↗
PubMed1999

Lung cancer in patients aged 50 years and younger: clinical characteristics, treatment details and outcome.

Younger patients (< or = 50 years of age) develop lung cancer. Many series report 5-10% of all cases occurring in younger patients. Outcome, inspite of treatment, is universally poor. Females and adenocarcinomas are over-represented and the aetiology for such an early-age presentation is unclear. The aims of this retrospective study were to review the clinical characteristics, treatment details and outcome of patients aged 50 years or younger diagnosed with lung cancer (small cell and non-small cell). Over a period of 34 months, 497 lung cancer patients were treated at the Liverpool Hospital Cancer Therapy Centre. Thirty-seven (7.4%) patients aged less than or equal to 50 years were identified. The median age at diagnosis was 44 years (range 32-49 years) in 20 females and 17 males. Adenocarcinoma was the predominant histological subtype (32%). No referred patient had stage I/II disease. Almost 90% of patients were smokers. Median survival following diagnosis was 12 months (range, 9 days-68 months) with 70% having died by the close of study. The clinical characteristics and outcome of young patients in our study were comparable to other similar series.

Adult↗
PubMed1999

Inhibition of glial scarring in the injured rat brain by a recombinant human monoclonal antibody to transforming growth factor-beta2.

The transforming growth factor-betas (TGF-betas) are potent fibrogenic factors implicated in numerous central nervous system (CNS) pathologies in which fibrosis and neural dysfunction are causally associated. In this study, we aim to limit the fibrogenic process in a model of CNS scarring using a recombinant human monoclonal antibody, derived from phage display libraries and specific to the active form of the TGF-beta2 isoform. The implicit inference of the work was that, as such antibodies are potential pharmacological agents for the treatment of human CNS fibrotic diseases, validation of efficacy in a mammalian animal model is a first step towards this end. Treatment of cerebral wounds with the anti-TGF-beta2 antibody led to a marked attenuation of all aspects of CNS scarring, including matrix deposition, formation of an accessory glial-limiting membrane, inflammation and angiogenesis. For example, in the wound, levels of: (i) the connective tissue components fibronectin, laminin and chondroitin sulphate proteoglycan; and (ii) wound-responsive cells including astrocytes and macrophages/microglia, were markedly reduced. Our findings suggest that such synthetic anti-fibrotic TGF-beta antibodies are potentially applicable to a number of human CNS fibrotic diseases to arrest the deposition of excessive extracellular matrix components, and maintain and/or restore functional integrity.

Animals↗
PubMed1999

Cutting film violence: effects on perceptions, enjoyment, and arousal.

The authors investigated the effects of cutting specific graphic scenes of film violence on self-reports of arousal, enjoyability, and perceptions of violence among a sample of U.S. students. In 3 studies, they varied film exposure from 1 1/2 min in the 1st study to a complete motion picture (American vs. British version of same film) in the 3rd. In all 3 studies, the participants rated the cut versions as less violent than the uncut versions. The participants distinguished quite subtle differences in levels of violence, even when the cuts were minor and contextualized within an entire movie. Cutting the movie significantly increased its enjoyability for the women; for the men, there was no significant difference. Cutting violent films made no difference in arousal for the men but substantially lowered self-report levels of arousal for the women.

Adolescent↗
PubMed1999

Secreted human conjunctival mucus contains MUC5AC glycoforms.

This study addresses the extent of variation in secreted end-product mucins in human conjunctival mucus. The aim was to determine whether the variety of mucin species found was encompassed by the mucin genes which have been cloned to date. Extraction into guanidine hydrochloride and separation of mucin constituents, by a combination of cesium chloride density gradient centrifugation, size separation on Sepharose CL-2B, MonoQ ion exchange chromatography and agarose gel electrophoresis, demonstrates a complex mixture of mucins. Sample size limitations precluded compositional amino acid analysis. MUC 5AC and MUC1, 2, and 4 are all detected in the buoyant density range 1.3-1.5 g/ml by antibody binding. The mucins vary in size from >40 x 10(6)to <97 x 10(3)Da. A wide range of molecular size was confirmed using rate zonal centrifugation. The presence of smaller species contrasts with other mucous secretions similarly studied. In each size range are low, medium, and high charge mucins. Sialylation predominates in the medium charge and sulfate in the high charge. Only MUC5AC cross-reactivity is maintained throughout the analysis. It is detected in large and medium sized mucins but accounts for only the least mobile mucins within copurified species of similar density, size, and charge resolved using agarose electrophoresis. MUC5AC cross-reactivity is also detected in both medium and high charge species, indicating the presence of glycoforms.

Adolescent↗
PubMed1999

Distinct sites of insulin-like growth factor (IGF)-II expression and localization in lesioned rat brain: possible roles of IGF binding proteins (IGFBPs) in the mediation of IGF-II activity.

Although expression of the IGF-II has been demonstrated within the central nervous system (CNS), past studies have failed to reveal its precise roles or responses subsequent to a traumatic injury. To demonstrate that IGF-II, IGFBP, and IGF receptor (-R) expression alters in response to a penetrating CNS injury, we used the techniques of ribonuclease protection assay, in situ hybridization, immunohistochemistry, Western blotting, and RIA. Under normal physiology, IGF-II expression is restricted to the mesenchymal support structures of the brain, including the choroid plexus, where its expression is coincident with that of IGFBP-2. Between 1-7 days post lesion (dpl), in the acute phase following a penetrant wound to the CNS, IGF-II and IGF-IIR protein, but not messenger RNA, were colocalized, with IGF-I, IGF-IR, and IGFBP-1, -2, -3, and -6, to neurons, macrophages, astrocytes, and microglia within the damaged tissue. Within the cerebrospinal fluid (CSF), levels of IGF-II peptide increased to peak at 7 dpl. IGFBP-2, -3, and -6 were also observed within the CSF, with IGFBP-2 predominating and exhibiting an increase in binding efficiency from 7-10 dpl. In the chronic phase of injury (7-14 dpl), an increase in both IGF-II, IGF-IIR and IGFBP-5 messenger RNA and protein was observed specifically and focally in the marginal astrocytes forming the limiting glial membrane of the wound. Thus, our evidence suggests that there are two mechanisms of action for IGF-II within the injured rat brain. During the acute phase, the secretion of IGF-II from the choroid plexus into the CSF is up-regulated, resulting in increased transport of the peptide to the wound. In the CSF, transported IGF-II is complexed to IGFBP-2 and essentially demonstrates an endocrine mode of action with a balance of locally produced IGFBPs modulating its bioactivity in the wound. Later in the wounding response, levels of IGF-II decline in the CSF and the wound neuropil, possibly with the aid of increased IGFBP-5 levels that may help to locally sequester and down-regulate IGF-II activity. Hence, in the chronic phase of the injury response, IGF-II reasserts itself to a predominantly autocrine/paracrine role restricted to the mesenchymal support structures, including the glia limitans, which may help reestablish and maintain tissue homeostasis.

Animals↗
PubMed1999

The relationships among pulmonary function, aerobic fitness, and cognitive functioning in older COPD patients.

STUDY OBJECTIVES: To study the predictive relationships among age, pulmonary function, aerobic fitness, and cognition in people with COPD. DESIGN: Observational study conducted during baseline testing with COPD patients who volunteered to participate in an exercise intervention. PARTICIPANTS: Older adults (age, 56 to 80 years) with COPD. MEASUREMENTS AND RESULTS: Age, depression, education level, aerobic fitness, blood oxygen saturation levels, and pulmonary function were assessed. Participants were randomly assigned to take cognitive tests of (1) fluid intelligence, (2) processing speed and working memory span, or (3) processing speed and inhibition. After controlling for education and depression (F(2,57) = 7.43; r(2) = 0. 21), performance on the 6-min walk (F(1,56) = 15.27; r(2) = 0.17) and age (F(1,55) = 7.52; r(2) = 0.08) were significant predictors of fluid intelligence. On the speed-of-processing task, performance on the 6-min walk (F(1,30) = 8.17; r(2) = 0.20), maximum voluntary ventilation (F(1,29) = 5.81; r(2) = 0.16), and age (F(1,28) = 5.26; r(2) = 0.10) were significant predictors. FVC was a significant predictor (F(1,25) = 6.37; r(2) = 0.18) of working memory span. The ability to inhibit a response was not significantly predicted by any of the variables assessed. CONCLUSIONS: In an older COPD sample, age, aerobic fitness, and pulmonary function are predictive of cognitive performance on various tasks. In particular, age and aerobic fitness are predictive of speed of processing, which is a cognitive variable that may itself underlie performance on a majority of cognitive tasks.

Adult↗
PubMed1999

Hyperglycemia attenuates the gastrokinetic effect of erythromycin and affects the perception of postprandial hunger in normal subjects.

OBJECTIVE: The major aims of this study were to determine in normal subjects whether the effects of erythromycin on gastric emptying, postprandial hunger, and fullness are modified by the blood glucose concentration. RESEARCH DESIGN AND METHODS: A total of 10 normal subjects (aged 20-39 years) underwent concurrent measurements of gastric emptying, blood glucose, hunger, and fullness on four separate occasions: twice during euglycemia (approximately 4 mmol/l) and twice during hyperglycemia (approximately 15 mmol/l). Either erythromycin (3 mg/kg) or saline (0.9%) was administered intravenously immediately before ingestion of a radioisotopically labeled solid meal. RESULTS: Gastric emptying was slower (P < 0.0001) during hyperglycemia when compared with euglycemia after both erythromycin and saline administration. During hyperglycemia, erythromycin reduced the lag phase (77.8 +/- 12.6 vs. 20.3 +/- 7.3 min; P < 0.05) but had no effect on the postlag emptying rate (0.32 +/- 0.077% per min vs. 0.24% per min). Hunger decreased (P < 0.001) and fullness increased (P < 0.001) after the meal. Postprandial hunger was less during hyperglycemia after saline infusion (P < 0.05) but not after erythromycin. Hunger was greater after erythromycin during both hyperglycemia and euglycemia (P < 0.05). CONCLUSIONS: At a blood glucose concentration of approximately 15 mmol/l, 1) gastric emptying of a solid meal is slower, when compared with euglycemia, even after administration of erythromycin; 2) the effect of erythromycin on gastric emptying of a solid meal is attenuated; and 3) the perception of postprandial hunger is reduced.

Adult↗
PubMed1999

Cells expressing the NG2 antigen contact nodes of Ranvier in adult CNS white matter.

The NG2 antibody, which recognises an integral membrane chondroitin sulphate, labels a significant population of cells in adult CNS white matter tracts of the rat optic nerve and anterior medullary velum (AMV). Adult NG2+ cells are highly complex with multiple branching processes and we show by EM immunocytochemistry that they extend perinodal processes, which contact nodes of Ranvier. NG2+ cells do not react to conventional immunohistochemical markers for adult glia and so we reservedly term them NG2P cells. In vitro, NG2 labels oligodendrocyte-type-2 astrocyte (O-2A) progenitors that can give rise to oligodendrocytes or type-2 astrocytes, depending on the culture medium. Thus, it is possible that NG2P cells may be derived from the same stem cells as oligodendrocytes. Interestingly, NG2+ cells identified previously in adult CNS displayed phenotypic characteristics of O-2Aadult progenitors and it is possible that, like them, NG2P cells might retain the capacity of generating oligodendrocytes in the adult CNS. This may be an important role of NG2P cells in demyelinating diseases such as multiple sclerosis. It is significant therefore that the perinodal processes of NG2P cells contact the only sites of exposed axolemma in myelinated axons, so that NG2P cells are ideally situated to detect and respond to changes in axonal function during demyelination. A further implication of our finding is that NG2P cells may perform functions at nodes of Ranvier previously attributed to perinodal astrocytes, including the clustering and maintenance of sodium channels in the axon membrane at nodes, during development and following demyelination.

Animals↗
PubMed1999

Visual clues in minimally invasive surgery: use of 2-D versus 6-D enhanced performance of complex minimally invasive complex skills.

UNLABELLED: In the recent past, we used two 2-D videoscopes to obtain both a close detailed view and simultaneously a panoramic view to improve the efficient and safe access for instruments into the microscopic working field by way of the benefits of the panoramic view. This bi-modal visual set of clues allows for (1) insertion of suture, (2) cutting of suture with scissors (3) retraction of tissue, and (4) removal of suture and needle. During these experiences, we observed the benefits accrued to the surgeon by allowing the focusing of his/her attention on the work (technical skills) without diffusing energy to other activities. Similarly, when training surgeons to perform micro-anastomoses, and while working to improve performance in micro-anastomoses, we hypothesize that two or more videoscopic views of the 3-dimensional working space would provided added visual information to the surgeon during the microscopic work. To examine this hypothesis, we have used a non-animate model, in the performance of complex skills in videoscopic surgery. METHODS: Inanimate videoscopic models for suturing and tying (24 studies) were used in this study. The technical skill studied was the sophisticated skill of suturing. The speed and accuracy of Free-Handed suturing and tying was determined in these studies. They were compared using a single 2-D system verses three videoscopic views reconstructing a 3-D effect. RESULTS: In each of these models, the delineation of multiple views allowed greater detailed 3-dimensional information for the surgeon. The sutures were placed faster, more accurately, and with fewer false motions. These data allow us to conclude the use of multiple high-resolution 2-D views will improve accuracy and efficiency in the performance of delicate and precise skills in videoscopic surgery.

Clinical Competence↗