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Biomedical subjects

M Berry

Publications and source records attributed to M Berry.

At least 91 records · Page 5Linked to original sources
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↗
PubMed1998

Axon-glial relations during regeneration of axons in the adult rat anterior medullary velum.

The anterior medullary velum (AMV) of adult Wistar rats was lesioned in the midsagittal plane, transecting all decussating axons including those of the central projection of the IVth nerve. At selected times up to 200 days after transection, the degenerative and regenerative responses of axons and glia were analyzed using transmission and scanning electron microscopy and immunohistochemistry. In particular, both the capacity of oligodendrocytes to remyelinate regenerated fibers and the stability of the CNS/PNS junctional zone of the IVth nerve rootlet were documented. Transected central AMV axons exhibited four patterns of fiber regeneration in which fibers grew: rostrocaudally in the reactive paralesion neuropil (Group 1); randomly within the AMV (Group 2); into the ipsilateral IVth nerve rootlet, after turning at the lesion edge and growing recurrently through the old degenerated contralateral central trochlear nerve trajectory (Group 3); and ectopically through paralesion tears in the ependyma onto the surface of the IVth ventricle (Group 4). Group 1-3 axons regenerated unperturbed through degenerating central myelin, reactive astrocytes, oligodendrocytes, microglia, and large accumulations of hematogenous macrophages. Only Group 3 axons survived long term in significant numbers, and all became myelinated by oligodendrocytes, ultimately establishing thin sheaths with relatively normal nodal gaps and intersegmental myelin sheath lengths. Schwann cells at the CNS/PNS junction of the IVth nerve rootlet did not invade the CNS, but astrocyte processes grew across the junction into the PNS portion of the IVth nerve. The basal lamina of the junctional glia limitans remained stable throughout the experimental period.

Animals↗
PubMed1998

Differential expression of the L- and S-isoforms of myelin associated glycoprotein (MAG) in oligodendrocyte unit phenotypes in the adult rat anterior medullary velum.

We have previously demonstrated differences in the expression of carbonic anhydrase II (CAII) in oligodendrocyte units myelinating small and large diameter fibres in the anterior medullary velum (AMV) of the adult rat (each unit comprises the cell body, processes and myelin sheaths). Others have indicated that myelin composition may also vary with respect to myelin basic protein (MBP) and proteolipid protein (PLP), and the small (S)- and large (L)-isoforms of myelin associated glycoprotein (MAG). In this study, we have determined the expression of myelin proteins in oligodendrocyte unit phenotypes I-IV, which myelinate fibres ranging in diameter from 0.3-12 microns diameter in the AMV, by using double immunolabelling for Rip, which labels entire units, and MBP, PLP, myelin oligodendrocyte glycoprotein (MOG), L-MAG and S-MAG. We show differences in the expression of L- and S-MAG in units which myelinate different diameter fibres: (1) type I/II units myelinating small diameter fibres had a L-MAG+/S-MAG-/CAII+ phenotype; (2) type II/III units myelinating different diameter fibres had a L-MAG+/S-MAG+/CAII+ phenotype; (3) type III/IV units myelinated large diameter fibres had a L-MAG+/S-MAG+/CAII- phenotype. All units, irrespective of fibre diameter, expressed Rip, MBP, PLP and MOG. The results indicate that type I-IV units may be variants of a single oligodendrocyte population and that phenotypic differences are determined by the diameter of fibres within the unit. The possible significance of metabolic and biochemical differences between oligodendrocytes myelinating small and large diameter axons are discussed with reference to the pathology of demyelination.

Age Factors↗
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↗
PubMed1998

Axon-myelin sheath relations of oligodendrocyte unit phenotypes in the adult rat anterior medullary velum.

Axon-oligodendrocyte relations of Rip-immunolabelled and dye-injected oligodendrocyte units are characterised in the adult rat anterior medullary velum (AMV). Each oligodendrocyte unit comprised the oligodendrocyte cell body, processes and the internodal myelin segments they support. Oligodendrocyte units corresponded to classically described type I/II or type III/IV unit phenotypes which respectively myelinated discrete populations of small and large diameter axons, delineated by a myelinated fire diameter of 2-4 microns (diameter of the axon plus its myelin sheath). Within units, mean fibre diameter was directly related to mean internodal length and inversely related to the number of myelin sheaths in the unit. The relationship between fibre diameter and internodal length was retained in units which myelinated axons of different diameters, indicating that axon diameter was an important determinant of the longitudinal dimensions of myelin sheaths. We also show that type III/IV units maintained a far greater volume of myelin than type I/II units. It was concluded that type I/II and III/IV oligodendrocytes represent two functionally and morphologically distinct phenotypes whose distribution densities were determined by the diameter and spatial dispersion of axons.

Age Factors↗
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↗