Biomedical subjects

V E Centonze

Publications and source records attributed to V E Centonze.

21 records · Page 2Linked to original sources

PubMedDate not supplied

Immunogold-labeled microtubule crossbridges in platinum-carbon replicas of the marginal band of erythrocyte cytoskeletons.

Cytoskeletons of erythrocytes from the toad Bufo marinus are composed of a surface-associated cytoskeleton that encapsulates the annular bundle of microtubules known as the marginal band (MB) and the centrally located nucleus. As seen by phase-contrast microscopy, the microtubules (MTs) of the MB remain tightly bundled after cell lysis without the need for added stabilizing factors. The integrity of this structure suggested that in addition to MTs other components were present in the MB and were responsible for its stability. Thin (less than 18 nm) platinum-carbon (Pt-C) replicas of freeze-dried cytoskeletons prepared by using a modified Balzers 300 system provided a novel method of sample preparation for a high-resolution study of the ultrastructure of the MB. Electron micrographs of replicas revealed that, the MTs of the MB displayed numerous filamentous projections which, when viewed in stereo, appear as side-arm connections between adjacent MTs. Immunofluorescence data show that monospecific antibodies to tubulin and to MT-associated protein 2 (MAP2) from brain each detect cross-reactive material in the MB. The combination of immunogold cytochemistry with Pt-C replication provided the increased resolution required to identify the individual structures recognized by antibodies to tubulin and MAP2. As expected, antitubulin labeled the MTs of the MB. However, anti-MAP2 antibodies were localized specifically to the cross-bridging filaments between adjacent MTs. Thus, a MAP2-like protein was identified in situ as the crossbridging filament that bundles MTs to form a stable MB.

Animals↗

PubMedDate not supplied

Visualization of individual reovirus particles by low-temperature, high-resolution scanning electron microscopy.

We used low-temperature, high-resolution scanning electron microscopy (cryo-HRSEM) to visualize surface structures on individual reovirus particles. Both intact virions and two forms of subvirion particles--infectious subvirion particles and cores--were examined, and despite some distortion of particles during specimen preparation and viewing in the microscope, the images obtained by cryo-HRSEM exhibited a level of interpretable detail not routinely achieved by other methods without image averaging. Cryo-HRSEM images of discrete reovirus particles were used to characterize and confirm features of the outer protein capsid of this virus by comparison with image reconstructions previously derived from cryotransmission electron microscopy. Distinct surface features attributable to each of the four outer-capsid proteins were identified. In addition, cryo-HRSEM images confirmed that significant changes occur on the surfaces of individual reovirus particles during disassembly and entry of cells and that the reovirus outer capsid is organized as a left-handed T = 13 icosahedron. Several unique capabilities and potential uses suggest that cryo-HRSEM has a place alongside other, more established methods for molecular characterizations of virus particles.

Capsid↗

PubMedDate not supplied

Composition of the extracellular matrix of the peritoneum.

OBJECTIVE: To localize the extracellular matrix proteins collagen I, collagen IV, fibronectin, and laminin in the peritoneal membrane. STUDY DESIGN: Peritoneal biopsies (n = 13) from the anterior abdominal wall and the uterine serosa (n = 3) were incubated with antibodies to collagen IV, laminin, collagen I, and fibronectin. Specimens were examined using light and confocal laser scanning microscopy. RESULTS: All of the extracellular matrix (ECM) proteins were present immediately under the mesothelium. Collagen (Col) IV and laminin (LM) were seen in the smooth muscle of microvascular structures, in the subendothelial basement membrane, and were present in a fascicular pattern in the peritoneal stroma. Collagen I was distributed diffusely in the peritoneal stroma. Fibronectin was also present in the subendothelial basement membrane. CONCLUSIONS: The resolution of the confocal microscope allowed for localization of extracellular matrix proteins in relation to the mesothelium. The presence of collagen IV, laminin, collagen I, and fibronectin under the mesothelium suggests that cells invading the peritoneum must have the ability to degrade and remodel this matrix.

Adult↗