Search PubMed⌕ Search

Biomedical subjects

M Berry

Publications and source records attributed to M Berry.

At least 19 recordsLinked to original sources
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

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↗
PubMed1998

Arterial haemorrhage following instillation of silver nitrate in chyluria: treatment by coil embolization.

Chyluria is a urological manifestation of lymphatic system disease. Sclerotherapy of the renal pelvis (RPIS) using 1% silver nitrate, along with diethyl carbamazine, is the treatment most frequently used. Massive haematuria due to intrarenal aneurysm following RPIS has not been reported. A case is described here of arterial haemorrhage following instillation of silver nitrate which was treated by coil embolization. The haematuria was immediately stopped and the renal function returned to normal gradually.

Adult↗
PubMed1998

Chest wall tuberculosis simulating breast carcinoma: imaging appearance.

Tuberculosis of the breast is a rare disease. Tubercular abscesses predominantly affecting the soft tissues are also very infrequent. A case of chest wall tuberculosis secondarily involving the breast presenting as a hard, fixed lump simulating mammary carcinoma is presented here. There was no evidence of pleural or pulmonary tuberculosis.

Breast Diseases↗
PubMed1998

Klippel-Trenaunay syndrome: unusual magnetic resonance features.

Klippel-Trenaunay syndrome (KTS) is a congenital vascular abnormality consisting of a cutaneous naevus, varicose veins and bone and soft-tissue hypertrophy affecting one or more limbs. A case is presented here with some unusual associated findings seen on MR that, to the best of the authors' knowledge, has not been reported in the literature. Although colour Doppler in addition to venography is frequently used in demonstration of the KT vein, MRI may well have an important role in complete assessment.

Adolescent↗
PubMed1997

Platelet-derived growth factor delays oligodendrocyte differentiation and axonal myelination in vivo in the anterior medullary velum of the developing rat.

The AA dimeric form of platelet-derived growth factor (PDGF-AA) is implicated in the differentiation of cells of the oligodendrocyte lineage, which express PDGF receptors of the alpha subunit type (PDGF-alphaR). In the present study, we show that a single injection of PDGF-AA into the cerebrospinal fluid of neonatal rats delays oligodendrocyte differentiation and interrupts the progress of myelination in the anterior medullary velum (AMV), a white matter tract roofing the IVth ventricle of the brain. PDGF-AA or saline was injected intrathecally in postnatal day (P) 7 rats, and the AMV was subsequently removed and immunolabelled with the oligodendrocyte-specific antibody Rip, at P9, P12, and P21, corresponding to postinjection days (PID) 2, 5, and 14. At P9 (PID2), myelination was retarded in PDGF-AA-treated rats as opposed to saline-treated controls but progressed rapidly after P12 (PID5). Quantification supported the qualitative observations that PDGF-AA mediated an acute decrease in the number of Rip+ oligodendrocytes at P9-12, which largely recovered by P21, suggesting that PDGF-AA may have delayed recruitment of myelinating oligodendrocytes. However, the definitive number of Rip+ oligodendrocytes in the AMV was not increased, suggesting that its action as a promoter of early oligodendrocyte survival may not ultimately affect the definitive number of myelinating oliogdendrocytes in vivo. We discuss the possibilities that excess PDGF-AA may have acted on early oligodendrocytes (precursors or preoligodendrocytes) to either (1) delay their differentiation by maintaining them in the cell cycle or (2) accelerate their differentiation, which may result in premature cell death in the absence of synchronised survival signals. This study supports a role for PDGF-AA in the timing of oligodendrocyte differentiation in vivo, as has been shown in vitro.

Animals↗
PubMed1997

Mesothelioma incidence and community asbestos exposure.

This study evaluates the environmental, nonoccupational component of mesothelioma incidence among persons living in Manville, Somerset County, New Jersey, the location of the largest asbestos manufacturing plant in North America. Prior to removal of occupational cases, residents of Manville had an average annual (1979-1990) mesothelioma rate of 636 male cases and 96 female cases per million population, about 25 times higher than average state rates. Somerset County had 143 diagnosed mesothelioma cases reported to the population-based. New Jersey State Cancer Registry from 1979 through 1990. Cases were removed from the analysis when their "usual employment" was reported as being at the asbestos plant, as evidenced through union lists or occupational information from either the Cancer Registry or mortality records. Standardized incidence ratios (SIRs) were computed for residents of Manville and Somerset County (less the Manville population) by sex. New Jersey mesothelioma rates less the Somerset County contribution, 1979-1990, were used to generate the expected number of cases. The SIRs for Manville males and females were respectively 10.1 [95% confidence interval (CI): 5.8-16.4] and 22.4 (95% CI: 9.7-44.2). Male and female Somerset County mesothelioma incidence rates were 1.9 (95% CI: 1.4-2.5) and 2.0 (95% CI: 1.0-3.6). This record-based approach demonstrates a strong relationship between past asbestos exposure from living in Manville and eventual development of mesothelioma. The use of methods in this study may be helpful in evaluating hazards of other known occupational carcinogens found in community settings.

Asbestos↗
PubMed1997

PDGF-alpha receptor and myelin basic protein mRNAs are not coexpressed by oligodendrocytes in vivo: a double in situ hybridization study in the anterior medullary velum of the neonatal rat.

Platelet-derived growth factor (PDGF) is a growth-regulatory dimer with A and B subunits. PDGF-AA, acting via PDGF receptors of the alpha-unit subtype (PDGF-alphaR), is implicated in the differentiation of oligodendrocyte precursors and in the survival of newly formed oligodendrocytes, which gradually lose expression of PDGF-alphaR. However, it is unclear whether terminally differentiated oligodendrocytes express PDGF-alphaR in vivo. To address this question, and to help clarify the role of PDGF-AA in late oligodendrocyte differentiation, we have used double in situ hybridization with digoxigenin- and fluorescein-labeled riboprobes to relate PDGF-alphaR mRNA and myelin basic protein (MBP) mRNA expression in the isolated intact anterior medullary velum (AMV) of rats ages Postnatal Day (P) 10-12 and P30-32. In parallel experiments, AMV were immunolabeled with the oligodendrocyte-specific monoclonal antibody Rip to provide information on oligodendrocyte development and the extent of myelination. At P10, the AMV contained tracts in which axons ranged from unmyelinated to fully myelinated, whereas myelination was complete in P30-32 AMV. The first oligodendrocytes to express MBP mRNA or Rip were promyelinating oligodendrocytes, which had a "star-burst" morphology and had not yet begun to form myelin sheaths. As myelination proceeded, MBP mRNA became dispersed throughout oligodendrocyte units, comprising cell somata, processes, and internodal myelin sheaths. By P30-32, MBP mRNA had been redistributed to the myelin sheaths only, reflecting a change in the site of protein synthesis in mature myelinated axon tracts. At no stage of oligodendrocyte differentiation did we observe cellular coexpression of mRNA for PDGFalphaR and MBP. Our results indicated that oligodendrocytes lost the expression of PDGFalphaR prior to gaining that of myelin gene products, and preclude an action of PDGF-AA on Rip+/MBP+ star-burst promyelinating oligodendrocytes. The spatial and temporal expression of PDGF-alphaR mRNA in the AMV was inversely related to the pattern of maturation of both myelin and oligodendrocytes, and is consistent with PDGF-alphaR being expressed by pro-oligodendrocytes. A notable finding was the high level of expression of PDGF-alphaR mRNA in the AMV of juvenile rats, localized to cell bodies within the myelinated axon tracts, strongly suggesting that oligodendrocyte precursors persisted in the mature velum.

Animals↗
PubMed1997

The unusual imaging appearance of primary retroperitoneal teratoma: report of a case.

Primary retroperitoneal (RP) teratoma is a rare entity which has a distinctive imaging appearance. We describe herein the case of a 25-year-old man in whom a RP teratoma was found to have an extremely unusual imaging morphology by ultrasound and computed tomography (CT). The tumor was resected and histopathological examination confirmed the diagnosis of primary benign RP teratoma.

Adult↗
PubMed1997

Hyperopia correction by noncontact holmium: YAG laser thermal keratoplasty: five-pulse treatments with 1-year follow-up.

BACKGROUND: Previous noncontact holmium (Ho): YAG laser thermal keratoplasty (LTK) studies on correction of low to moderate hyperopia have used treatment algorithms based on ten-pulse, variable-pulse-energy treatment parameters. The purpose of this study was to evaluate the safety, effectiveness, and stability of new five-pulse, constant-pulse-energy treatment parameters for noncontact Ho:YAG LTK. METHODS: Thirty-nine hyperopic patient eyes [up to +4.75 diopters (D) refractive error] were treated using simultaneous noncontact delivery of Ho:YAG laser energy (Sunrise) with two symmetrical octagonal rings of eight spots per ring and radial spot patterns on centerline diameters of 5 and 6 mm (group A), 6 and 7 mm (group B), or 6.5 and 7.5 mm (group C). Each ring of spots received five pulses of laser light at 5 Hz pulse repetition frequency and a fixed pulse energy of 240 mJ. Thirty of the 39 patient eyes (77%) had 1-year follow-up exams. RESULTS: At 1 year, the mean Snellen uncorrected distance visual acuity lines gained was 3.7 +/- 0.5/6.8 +/- 2.7/5.3 +/- 3.3 for groups A, B, and C. The mean changes in subjective manifest refraction (spherical equivalent) were -2.08 +/- 1.13 D, -1.83 +/- 0.88 D, -1.22 +/- 0.88 D for groups A, B, and C respectively. None of the eyes lost two or more lines of spectacle-corrected distance visual acuity. There were no clinically significant complications in any patient. CONCLUSION: This clinical study indicates that five-pulse noncontact LTK treatments of low hyperopia are safe and effective. The stability has to be confirmed with longer follow-up.

Adult↗
PubMed1997

Hyperopia correction by noncontact holmium:YAG laser thermal keratoplasty: U.S. phase IIA clinical study with 2-year follow-up.

PURPOSE: This study was performed to determine the long-term efficacy, safety, and stability of noncontact holmium:yttrium aluminum garnet (Ho:YAG) laser thermal keratoplasty (LTK) for correction of low-to-moderate hyperopia. METHODS: The authors treated 1 eye each of 28 patients for correction of low-to-moderate hyperopia (up to +3.88 diopters [D] refractive error) using the Sun 1000 Corneal Shaping System (Sunrise Technologies, Inc., Fremont, CA). Treatments were performed with one or two rings of eight spots per ring with centerline diameters of 6 mm (one ring) or 6 and 7 mm (two rings), ten pulses of laser light at 5-Hz pulse repetition frequency, and pulse energies ranging from 208 to 242 mJ. Follow-up was 2 years. RESULTS: At 2 years after surgery, uncorrected distance visual acuity was improved by 1 or more lines of Snellen visual acuity in 19 (73%) of 26 of the treated eyes. The mean lines gained was 2.5 +/- 2.2/3.3 +/- 2.7 for one- and two-ring treatment groups, respectively. The mean change in spherical equivalent of the subjective manifest refraction was -0.53 +/- 0.33 D/-1.48 +/- 0.58 D for one- and two-ring treatment groups. Regression between 1 and 2 years was 0.01 D and 0.16 D, respectively. In the one-ring treatment group (18 eyes), 13 eyes (72%) had refractive corrections (range, -0.38 to -1.13 D), and 5 eyes (29%) were unchanged (within +0.25 D) relative to their preoperative measurements. In the two-ring treatment group, all eight eyes (100%) had reductions in their hyperopia (range of corrections, -0.38 to -2.25 D). None of the eyes lost two or more lines of spectacle-corrected distance visual acuity. There were no sight-threatening complications. CONCLUSIONS: This initial U.S. clinical study indicates that noncontact laser thermal keratoplasty treatment of low hyperopia is safe and produces modest but persistent corrections with 2-year follow-up. Expanded studies of this treatment method are warranted.

Adult↗
PubMed1997

The relationship between developing oligodendrocyte units and maturing axons during myelinogenesis in the anterior medullary velum of neonatal rats.

Myelinogenesis was investigated in whole-mounted anterior medullary vela from rats aged postnatal day (P) 10-12, using double immunofluorescence labelling with Rip and anti-neurofilament 200 (NF200) antibodies, to identify oligodendrocytes and axons, respectively. A number of discrete phases of maturation of oligodendrocyte units were recognised. (1) Promyelinating oligodendrocytes co-expressed Rip and Myelin basic Protein and formed axonal associations, prior to ensheathment. (2) Transitional oligodendrocytes contained both ensheathing and non-ensheating processes. (3) Myelinating oligodendrocytes were established after a period of remodelling (in which non-ensheathing processes were lost), appearing as oligodendrocyte unit morphological phenotypes with a definitive number of incipient myelin sheaths. (4) Maturation of myelinating oligodendrocytes was defined as the establishment of internodal sheath lengths and the redistrubution of myelin basic protein from the cell somata and radial processes into the myelin sheaths only. Myelination was probably related to the maturational state of the axons, since it was initiated when the latter had attained a critical diameter of between approximately 0.2 and 0.4 micron, coincident with the expression of NF200. Oligodendrocyte differentiation and myelination of the AMV were asynchronous and multifocal, and at P10: (1) axons which were destined to be of the largest calibre in the adult AMV were already myelinated by early developing oligodendrocytes, whilst those which were destined to be the smallest calibre in the adult were unmyelinated, but ultimately became ensheathed by late developing oligoendrocytes; (2) axons were sequentially ensheathed by early developing myelinating oligodendrocytes and late developing promyelinating oligodendrocytes; (3) all axons were small calibre; (4) oligodendrocyte units exhibited polymorphism. Thus, the development of oligodendrocyte morphological phenotypes was not related solely to either the physical dimension of axon calibre at the time of ensheathment, nor oligodendrocyte birth dates.

Animals↗