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PubMed1980

Fibrous waveforms or crimp in surface and subsurface layers of hyaline cartilage maintained in its wet functional condition.

The structural features of hyaline cartilage maintained in its wet functional condition have been examined using the technique of Nomarski interference microscopy. The collagenous arrays and associated chondrocytes in both the extreme superficial layers and in the deeper subsurface zones were satisfactorily imaged with this technique. Most significantly the collagen fibers were observed to possess a geometric waveform or "crimp" of varying acuteness and the role of this crimp is discussed in relation to the mechanical and biological function of the tissue. It is clear from these wet tissue studies that the fibrous layout in hyaline cartilage is considerably more "disciplined" than has been previously recognized from morphological data obtained using more indirect experimental techniques involving prepared histological sections or scanning and transmission electron microscopy.

Animals↗
PubMed1991

The density of the cell sap and endoplasm of Nitellopsis and Chara.

We measured the densities of the cell sap, endoplasm and cell wall of Nitellopsis obtusa and Chara corallina using interference microscopy, refractometry, immersion refractometry, equilibrium sedimentation and chemical microanalysis techniques. These values are important for the determination of many rheological properties of the cytoplasm as well as for understanding buoyancy regulation, dispersal mechanisms and how cells respond to gravity. The average densities of the cell sap, endoplasm and cell wall are 1,006.9, 1,016.7 and 1,371 kg m-3 for Nitellopsis and 1,005.0, 1,013.9, and 1,355.3 kg m-3 for Chara.

Cell Wall↗
PubMed1992

A new morphological classification of urinary erythrocytes for differential diagnosis of glomerular hematuria.

A new morphological classification of urinary erythrocytes was instituted in order to differentiate glomerular from urological hematuria. One hundred and thirteen hematuric patients including 73 glomerular and 40 urological disease patients were examined. The former group consisted of IgA nephropathy (n = 45), lupus nephritis (6), membrano-proliferative glomerulonephritis (5), non-IgA mesangial proliferative glomerulonephritis (4), Henoch-Schoenlein purpura nephritis (4), membranous nephropathy (4), endocapillary proliferative glomerulonephritis (3), and minimal change nephrotic syndrome (2). The latter group included bladder cancer (n = 15), renal calculi (15), prostate cancer (3), urethral cancer (1) and post-transurethral resection (6). In each urine sample, 100 urinary erythrocytes were observed under differential interference microscopy and classified into 10 concretely defined shapes (5 "glomerular" and 5 "urological" shapes) and unclassified shapes. Using percentage of "glomerular" shape erythrocytes and setting the cut-off at 15%, 90.4% of sensitivity and 97.5% of specificity for the diagnosis of glomerular disease were obtained. When percentage of one specific shape (G1), [i.e. doughnut-like cell with one or more blebs] was used at a cut-off of 1%, sensitivity and specificity were 89.0% and 95.0% respectively. These results were satisfactory as compared with most previous reports. Moreover, our classification is so concrete that it is more objective, accurate, and easily understandable, even for beginners. Distinct shape "G1" is particularly important for morphological investigation of hematuria.

Diagnosis, Differential↗
PubMed1975

Encephalitis in suckling rats induced with rat cytomegalovirus.

Encephalitis has been induced in suckling rats by intracerebral inoculation of rat cytomegalovirus. This agent has been carried through five animal passages without changes in virulence. Principal sites of viral attack were the meninges and ependyma with limited parenchymal invasion from these sites. Characteristic features of cytomegalovirus disease observed included cytomegaly, formation of nuclear and cytoplasmic inclusions, and polykaryocytosis. Fundamental tinctorial and optical differences were noted between nuclear and cytoplasmic inclusions, the latter being characterized by their phloxinophilia which contrasts with the hematoxylinophilia of nuclear inclusions. Differential interference microscopy improved visualization and photography of cytoplasmic inclusions. Hydrocephalus developed in a few of the animals and was studied in late phases of the disease.

Animals↗
PubMed1989

Cytophotometric and interference microscopic investigations in carcinomas of the oral cavity.

The DNA content and the nuclear dry mass of 18 keratinized squamous cell carcinomas and their metastases, of one adamantinoma recurrence and two adenoid cystic carcinomas of the oral cavity were determined in comparison to the normal buccal mucosa using Feulgen scanning cytophotometry and interference microscopy. The squamous cell carcinomas could be classified into five groups based on their DNA distribution pattern. The nuclear dry mass and its variation were found to be different from the normal mucosal epithelial cells in all cases. No differences could be found between diploid cells and cells of a higher degree of ploidy. Therefore the relation of nuclear dry mass and DNA content appeared to be lower in cells of higher DNA ploidy. This fact is discussed in relation to the underlying molecular biological processes. This leads to the conclusion that the increase of the nuclear dry mass (mainly protein) precedes the increase of the DNA content. The combined measurement of DNA content and nuclear dry mass allows a better characterization of malignancy than each of the nuclear components measured alone. The difference of nuclear dry mass between malignant cells and normal mucosal epithelial cells is more sensitive than the deviation of the DNA content owing to the fact that malignant tumours with normal DNA content exist.

Carcinoma, Squamous Cell↗
PubMed1984

Microfilament distribution and adhesion patterns in cultured cells after glutaraldehyde-formaldehyde fixation.

To study the relationship between microfilament distribution and adhesion patterns in the same cultured cell, we have employed a simple glutaraldehyde-formaldehyde fixation technique followed by permeabilization of the cells in buffered Triton X-100. This method gives an excellent preservation of cellular morphology in general and of adhesion patterns in particular for examination with surface reflection interference microscopy. It also permits the concomitant use of the actin-specific fluorescent probe NBD-phallacidin to visualize the distribution of microfilaments.

Cell Adhesion↗
PubMedDate not supplied

[Changes in the dry weight of retinal pigment epithelium cells in the postnatal ontogeny of rats].

The dry weight of cytoplasm of individual cells of the retinal pigment epithelium was determined by interference microscopy in the rats (both in mononuclear and binuclear cells). During postnatal development the dry weight of cell cytoplasm is subject to fluctuations: it increases from the 1st till the 5th day, decreases between the 5th and 15th days and increases again between the 15th and 18th days. It is suggested that the decrease in dry weight of cytoplasm of the retinal pigment epithelium cells precedes the onset of phagocytizing by these cells of shed discs of the external rod segments.

Animals↗
PubMed1982

[Action of hypothyroidism on the metabolic maturation of the pyramidal neurons of the rat hippocampus].

Interference microscopy was used to measure dry mass of pyramidal neurones of hippocampal CA1 and CA3 areas in control and hypothyroid rats aged 14 and 21 days and 2 months. Hypothyrosis was induced in the newborn by intraperitoneal injection of methylthiouracil to the lactating female during the lactation period (for 1 month). Hypothyrosis caused a considerable retardation of the animals' growth. A significant decrease in he concentration of dry substances was detected only in the cytoplasm of Ca1 area neurones in the group of 2-month-old hypothyroid animals. The measurements have demonstrated that hypothyrosis gives rise to pronounced retardation of the neuronal build-up and accumulation of protein products in the cytoplasma of hippocampal pyramidal cells in all the animal groups examined. The size and dry weight of neuronal nuclei of both the hyppocampal areas substantially diminish in the group of 2-month-old hypothyroid animals.

Aging↗
PubMed1994

An indirect comparison of third-body wear in retrieved hydroxyapatite-coated, porous, and cemented femoral components.

The osteoconductive properties of hydroxyapatite (HA)-coated titanium implants are well documented, but eventual coating degradation may result in HA particles adjacent to the substrate, and if the particles were to migrate into the joint space then accelerated polyethylene wear might be expected. As an indirect indication of third-body wear, the authors used laser interference microscopy to measure and compare surface roughness on modular heads from 15 clinically retrieved HA-coated femoral components, with heads from 15 retrieved uncemented (porous) and 15 cemented implants. The results showed increased median surface roughness over initial manufacturer specifications in all groups, but the cobalt-chrome heads from the HA-coated group showed significantly less surface roughness and less deep scratches than the heads from either the porous or uncemented group. Three-body wear appears to be a common problem, but evidence available suggests that it is no more of a problem with HA-coated devices than porous or cemented.

Cementation↗
PubMed1995

Histologic observations of bone remodeling adjacent to endosteal dental implants.

To examine bone morphology associated with endosteal dental implants at various time intervals, we inserted 20 one-stage and 20 two-stage titanium blade implants and 20 one-stage and 20 two-stage titanium root-form implants into 30 dog mandibles. Sixteen implants in 6 control (c) dogs (in situ five months) did not receive bridgework. Sixty-four implants in 24 dogs supported bridges for six, 12, 18, or 24 months. The entire area of the mandible containing the implants was examined by routine light and Nomarski differential interference microscopy (NM) for bone morphology (including osteon orientation) at the implant surface and at regions away from the implant. Control root-form implants were apposed by woven bone, with homogenous compact bone in the cortical plate distant to the implant. After 6 mo of load, immature bone was predominant apposing the implant, but initial osteonal maturation was apparent. NM clearly demonstrated the interstitial and concentric lamellae of the bone. Surprisingly, compact bone formed internal to the cortical plate, an area where trabecular bone is expected. At later periods of load, more mature osteons were seen apposing the implants; however remodeling events were still apparent. These remodeling events extend further away from the implant than was expected if the events resulted only from surgical repair. Also, when the implant inclined so that half was totally in the cortical plate and half in the marrow (in trabecular patterns), osteonal bone appeared to remodel in both areas. Control blade implants and blades loaded for six months were apposed by immature osteons when the implant was placed into the cortical plate. A trabecular meshwork was inferior to the osteonal bone. At 12 mo of load, the bone internal to the cortical plate appeared similar to the lamina dura supporting teeth; however, no PDL existed; the lamina-dura-like pattern directly apposed the implant. Even after 24 mo of load, extensive bone remodeling was apparent adjacent to the implant, markedly different from the bone making up the existing cortical plate. From these data, remodeling activities to blade implants may involve the development of a lamina-dura-like bone morphology after longer periods of load. Osteonal bone was apparent, but only at regions where the implant was inserted into the cortical plate. Further, bone remodeling was apparent even after long periods of load.

Alveolar Process↗
PubMed1988

Growth cone configuration and advance: a time-lapse study using video-enhanced differential interference contrast microscopy.

We have analyzed the dynamics of growth cone configuration using video-enhanced contrast differential interference contrast microscopy. Regenerating neurites from NGF-treated PC12 cells and sympathetic neurons were observed in real time during their elongation and reviewed by time-lapse video recordings. This technique provided a high-resolution view of motile growth cone elements including filopodia, microspikes, lamellipodia and ruffles. On the basis of our observations, a multistage model for growth cone advance is proposed. Elongation commences with lamellipodial spreading. If the newly extended lamellipodium does not retract or lift off the substrate in the form of a ruffle, a second phase--consolidation--occurs, in which the lamellipodium thickens as it fills with cytoplasm and organelles. The consolidated area then undergoes further transformation into an area of neuritic shaft as new lamellipodia form at the leading and peripheral zones of the distal process. We never observed filopodia or microspikes contracting to propel the growth cone forward. We also noted that elongating tips generally had large varicosities within 20 micron of their leading edges. These may play a role in neurite outgrowth and in the formation of smaller, synaptic vesicle-containing varicosities. The dynamic behavior of the growth cone was under the control of NGF. Withdrawal of NGF resulted in the disappearance of motile structures and cessation of growth, while readdition of NGF triggered the rapid reappearance of these structures and the resumption of growth. The high-resolution video microscopy of living growth cones provides necessary baseline information, as well as a bioassay paradigm, for future studies on the molecular mechanisms of nerve growth.

Adrenal Gland Neoplasms↗
PubMedDate not supplied

Wavelength-dependent roughness: a quantitative approach to characterizing the topography of rough titanium surfaces.

Topographies of grit-blasted, etched, grit-blasted and etched, and microfabricated and etched surfaces of commercially pure titanium have been investigated. Such surface topographies vary across the scale range of interest for dental implants, extending from nanometers to millimeters. The complete characterization of topography requires the use of complementary methods. This study compared the topographic characterization methods of non-contact laser profilometry, interference microscopy, stereo-scanning electron microscopy (stereo-SEM), and atomic force microscopy. Non-contact laser profilometry was shown to be a useful method to characterize topographic features in the micron to millimeter range, whereas interference microscopy and stereo-SEM can be employed down to the submicron range. Stereo-SEM is particularly useful for quantifying topographies with complex, strongly corrugated ("sharp"), and high-aspect-ratio features and was shown to be complementary to non-contact laser profilometry and interference microscopy. Because of tip-related envelope problems, atomic force microscopy was not found to be suitable for the type of surfaces investigated in this study. Independent of the method used, the commonly used "integral" amplitude roughness parameters, such as Ra, Rq, or Rt, were often of limited value in the description of actual implant surfaces. The application of the wavelength-dependent roughness approach was shown to be an effective method for the description of surface topographies in the complete range of characteristic roughness and is also a useful means of examining the effects of surface treatment processes.

Analysis of Variance↗
PubMed1976

[Early stages of myocardial infarct studied by opitcal methods].

The hearts of 45 dogs were investigated at times from 10 minutes to 24 hours following ligation of the anterior interventricular branch of the left coronary artery. The material was fixed in formalin and embedded in parafin. It was established that at early stages of experimental myocardial infarction in the zone of eschemia there took place eschemic zone various foms of contactural damages, lumpy decmposition, relaxation and sarcoplasmic matrix. By the polarizing microscope method in the peripheral area of the eshemic zone various forms of contractural damages, lumpy decomposition, relaxation and desaggregation of myofibrills, were noted. Phaso-contrast and interference microscopy investigations revealed in the damaged cells an induration of the sarcoplasmic matrix due to an increase in the dry matter concentration. The studies conducted with the help of polarizing, phaso-contrast, and interference microscopy methods showed that by using these methods it is possible at early periods to reveal the zone of myocardial infarction on stained and unstained preparations prepared by conventional methods.

Animals↗
PubMed2002

Application of Nomarski interference contrast microscopy as a thickness monitor in the preparation of transparent, SiC-based, cross-sectional TEM samples.

Reflected light optical microscopy using a Nomarski prism and a differential interference contrast filter have been employed in concert to achieve a technique that provides an accurate color reference for thickness during the dimpling and ion milling of transparent transmission electron microscopy samples of 6H-SiC(000 1) wafers. The samples had thin films of AIN, GaN, and Au deposited on the SiC substrate. A sequence of variously colored primary and secondary interference bands was observed when the SiC was thinner than 20 microm using an optical microscope. The color bands were correlated with the TEM sample thickness as measured via scanning electron microscopy. The interference contrast was used to provide an indication of the dimpling rate, the ion milling rate, and also the most probable location of perforation, which are useful to reduce sample breakage. The application of pressure during the initial cross-sectional preparation reduced the separation of the two halves of the sample sandwich and resulted in increased shielding of the film surface from ion milling damage.

Journal Article↗