Cellular Diameter Research Articles

Ultrastructural features of functionally identified primary afferent neurons with C (unmyelinated) fibers of the guinea pig: classification of dorsal root ganglion cell type with reference to sensory modality.

Intracellular labeling of neurons permitted a direct correlation of neuronal profiles with sensory modality of cutaneous receptors. In the guinea pig, 47 neurons in the dorsal root ganglion (displaying C-fiber conduction velocities) were labeled with horseradish peroxidase (HRP) by iontophoresis after determining the sensory modality. Receptive field were explored with systematic "natural" stimuli. Cell areas of all C-fiber units were measured by tracing the cellular contour in light microscopy. The mean cellular diameter calculated from cell areas was 21.8 microns in the second cervical ganglion of the guinea pig. Mean cell diameter for high-threshold mechanoreceptors was 20.9 microns, 24.6 microns for polymodal nociceptors, and 25.7 microns for mechanical-cold nociceptors. Electron microscopic observations showed that all labeled neurons of C-fiber units had profiles of small, dark type-B neurons. Neurons representative of each sensory modality exhibited different cell features, each belonging to a distinct subtype of small B neurons. High-threshold mechanoreceptor and mechanical-cold nociceptor displayed a peripheral lamellar arrangement of cisternae of endoplasmic reticulum (ER), corresponding to the B1 subtype. Polymodal nociceptor units were characteristically of the B2 subtype, in which stacks of long and short cisternae of ER were distributed randomly throughout the cytoplasm, and the arrangement of Golgi bodies varied among these cells. Cooling receptors displayed poorly developed, flattened cisternae of ER and numerous vesicles, typical of the B3 subtype. These results imply that all C-fiber cells belong to the small B-type cell category and that the ultrastructural features of the neuron in the dorsal root ganglion may reflect the sensory modality of the receptive field.

Left ventricular failure induced by myocardial infarction. I. Myocyte hypertrophy.

To determine whether left ventricular failure after acute myocardial infarction is associated with a growth response of the myocytes that tends to compensate for the loss of muscle mass and function, the left coronary artery in rats was ligated near its origin, and the animals were killed 3 days later. Elevated left ventricular end-diastolic pressure and decreased first derivative of left ventricular pressure and systolic arterial pressure indicated significant impairment of ventricular function. Absolute infarct size, determined morphometrically by measurement of the fraction of myocyte nuclei lost, averaged 57%. Hypertrophy of surviving left ventricular myocytes was 28%, involving a 14% increase in cell length and a 6% increase in diameter. Right ventricular myocyte volume per nucleus increased 21% by a 10% enlargement of cellular diameter with no change in length. These results show on a cellular basis that myocardial hypertrophy in the left ventricle is accomplished by cellular shape changes characteristic of a combination of pressure and volume overload hypertrophy, whereas cellular growth in the right ventricle is consistent with pressure overload hypertrophy.

Morphology and Histochemistry of the Mucosa Surrounding Small Oligotubular Adenomas of the Large Bowel

The transitional mucosa surrounding adenomas and carcinomas of the large bowel is characterized by a reversion of mucus secretion from sulphomucin to sialomucin and a hyperplasia of crypts and epithelial cells. The specificity of this phenomenon is still a controversial issue. Therefore we studied 72 oligotubular adenomas of the large bowel and the adjacent mucosa by means of histochemistry and morphometry. The peak of sialomucin production is found within the crypts immediately adjacent to the adenoma, whereas the more distant crypts secrete less. The cellular diameter and the depth of the crypts behave in a similar manner, they decrease with increasing distance from the adenoma, still being much higher than in the normal mucosa. The crypt depth correlates well to sialomucin production. The existence of the transitional mucosa around small oligotubular adenomas may indicate, that this mucosal change is not merely secondary to the presence of carcinoma but may be of importance as a precursor lesion of neoplastic changes of the colon and rectum.

Distribution Pattern of Muscle Fiber Type in Musculus Biceps Brachii of White-Handed Gibbon

Histochemical examinations of muscle fiber types by Sudan black B staining were made on m. biceps brachii of male and female white-handed gibbon (Hylobates lar). Three types of muscle fibers could be discriminated in terms of the reaction to the pigment and the cellular diameter: red muscle fiber (type I) with a positive reaction and a small diameter; white muscle fiber (type II) with a weak reaction and a large diameter; intermediate muscle fiber (type III) with an intermediate reaction and diameter. Of 4648 muscle fiber cells, in average of male and female, scanned in the cross-section, red muscle fibers accounted for 44.1%, white muscle fibers 28.3%, and intermediate muscle fibers 27.6%, respectively. White muscle fibers were clearly localized in the external layers of both heads of m. biceps brachii. In contrast, red muscle fibers were more evenly distributed throughout the muscle though moderately localized in the regions adjacent to the sulcus bicipitalis medialis. Intermediate muscle fibers showed no specific localization at all. These results suggest that m. biceps brachii of the gibbon, an acrobatic armswinger, is inclined to be a red muscle that is fatigue-resisting rather than power-generating.

Immunocytochemical study of crustacean hyperglycemic hormone in the eyestalks of the prawn Palaemon serratus (Pennant) and some other Palaemonidae, in relation to variations in the blood glucose level.

With the use of rabbit antisera against crustacean hyperglycemic hormone (CHH), it is possible to describe a distinct immunopositive reaction in a group of neurosecretory cells in the medulla terminalis ganglionic X-organ2 (MTGX2 ), in the MTGX-sinus gland tract, and in a considerable part of the sinus gland from several species of prawns belonging to the Palaemonidae. By introductory studies on the CHH system in Palaemon serratus, we can postulate a sequence in the activity cycle of the CHH-producing cells on the basis of differences in staining intensity of the immunoreaction and such morphometric parameters as cellular and nuclear diameter. By studying the CHH-producing system in combination with variations in the glucose level of the blood, an "inverse relationship" is observed between the number of immunoreactive cells and the blood glucose level during different periods of the year as well as during different stages of the molting cycle. A "shift in phase" of this correlation during the diurnal cycle suggests that several rhythmical phenomena may play a role in the regulation of glycemia in Crustacea.

Coalignment of the muscle cell and nucleus, cell geometry and Vv in the tunica media of monkey cerebral arteries, by electron microscopy.

We undertook to ascertain how well aligned is the rod-shaped nucleus within the spindle-shaped cell of vascular muscle in order that we might use the darkly staining nucleus in histological sections to indicate precisely the directional alignment of the cell. We fixed cerebral arteries from five monkeys under physiological pressure and embedded portions of the tissue so that mid-plane longitudinal sections of the arteries were obtained; the circumferentially arranged muscle cells were cut in cross-section. From the electron micrographs we obtained the cross-sectional profile of the cell and its nucleus, determining that the centre of the nucleus was on average 9.5 +/- 5.8% (SD) away from the centre of the cell (expressed as a ratio of the cellular diameter). We calculated the alignment between the cell and nucleus to be from 0 to 3 degrees, and obtained a volume fraction of 59% for muscle tissue in the tunica media of these arteries.

Experimental ancylostomiasis in Swiss albino mice: adrenal and thyroid histopathology.

Remarkable hypertrophic changes were observed in the adrenal and thyroid glands of male mice after 7 to 16 days of infection with the filariform larvae of Ancylostoma caninum, but not in females. The adrenal gland revealed enormous enlargement of cells in the zonae glomerulosa, fasciculata and medulla, and also the formation of big vacuoles in the glomerular zone, whereas the thyroid gland showed distinctly hypertrophied follicular epithelium with marked acolloidal condition and follicular mass formation. These changes in the cellular diameter were highly significant (P greater than 0.001 to less than 0.005). The possible reasons for hyperactivity of these glands are discussed.

Nuclear size of G1/S transition cells measured by flow cytometry

Cellular DNA content and nuclear diameter data were measured for exponential and plateau phase Chinese hamster lung cells (line V279-171b) by flow cytometric analysis using mithramycin supravitally-stained cells. The nuclear diameter distributions were heterogeneous for both exponential and plateau phase cells. For exponential cells, a given nuclear diameter was not unique for any phase of the cell cycle. Based on dual-parameter contour and skewness analysis, it was concluded that the G1 transition to S phase occurs independent of G1 nuclear size.

The use of a simple method to avoid cell shrinkage during SEM preparation

In the course of preparing specimens for scanning electron microscopy, both glutaraldehyde and OsO4-fixed cells exhibit a considerable shrinkage with a reduction of the mean cellular diameter of about 45% after critical point drying. However, if cells are successively treated with glutaraldehyde, OsO4, tannic acid and uranyl acetate solutions, cellular shrinkage of only 5% is observed.

Preselection of alarms in a hybrid system for screening of cervical cancer.

In this report, a preselection of alarms in a system for automated screening of cervical cancer based on depositing the cell sample linearly as a "cell trace" on a tape and analyzing it at different decision levels with increasing complexity, and preliminary results on analyzing cervical material with this system are discussed. The "cell trace" is analyzed with the slit-scan technique. Six parameters are computed: 1) cellular diameter; 2) nuclear diameter; 3) nuclear fluorescence (acriflavin-Feulgen) as nuclear DNA; 4) cellular fluorescence; 5) nuclear to cytoplasm ratio (N/C ratio); and 6) nuclear density. At present, only nuclear fluorescence is used to define a decision boundary between normal and potentially atypical cells. Under this criteria the slit-scan analysis leaves 5% of the events in a sample that must be rechecked at a second decision level in normal cell samples. A further reduction is expected when several slit-scan parameters are used at the first decision step. All events declared suspicious will be investigated in more detail by a two dimensional image analyzing system where the fluorescence image is generated by a laser scanning system. Results obtained in preliminary experiments are discussed in this paper.

Zinc effects of Fathead minnow cell cultures

1. 1. The effects of zinc on cell cultures of the Fathead minnow ( Pimephales promelas) were studied. With the addition of higher concentrations of zinc (up to 50 mg Zn/l) to the growth medium, the cultures exhibited decreases in cell population. 2. 2. Cellular diameter and cell volume increased in cells grown in medium containing higher zinc concentrations. 3. 3. Soluble, insoluble and total protein contents of the cells also increased with increasingly higher zinc concentration. 4. 4. Atomic absorption data indicated increased zinc content in cells grown in higher concentrations of the metal. The accumulation of zinc was also evident in cells grown in zinc for a long-term period. 5. 5. O 2 consumption studies revealed a decrease in oxygen consumption per mg total protein in cells grown in increasingly higher zinc concentrations.

Left ventricular hypertrophy: A cytometric study on 42 human hearts

A histocytometric study of 42 left ventricles was carried out. The cases consisted of normal hearts as well as a number of hypertrophic hearts which were progressively heavier in weight. The results of this study were analyzed by computer. We found an increase in myocardial cell size correlated with an increase in the ventricular free wall weight, up to a critical weight of 250 g. Beyond that critical weight, cellular hyperplasia was evident, followed by the further development of hypertrophy, in relation to the increase of ventricular weight. At the “critical weight” the progressive increase of cellular diameter, which is less than the theoretical value, abruptly ends and then decreases considerably. In contrast, this same phenomena is not seen for the cell length. The myocardial cell length shows a constant gradual increase always greater than the theoretical value regardless of ventricular weight. For this reason the cellular hyperplasia specifically presents an increase in cellular length beyond the increase in cellular diameter, which is reduced. A multiplication of myocardial nuclei beyond the critical weight was also observed. The results obtained are of physiopathological significance owing to modifications of the capillary network and the interstitial tissues. A histocytometric study of 42 left ventricles was carried out. The cases consisted of normal hearts as well as a number of hypertrophic hearts which were progressively heavier in weight. The results of this study were analyzed by computer. We found an increase in myocardial cell size correlated with an increase in the ventricular free wall weight, up to a critical weight of 250 g. Beyond that critical weight, cellular hyperplasia was evident, followed by the further development of hypertrophy, in relation to the increase of ventricular weight. At the “critical weight” the progressive increase of cellular diameter, which is less than the theoretical value, abruptly ends and then decreases considerably. In contrast, this same phenomena is not seen for the cell length. The myocardial cell length shows a constant gradual increase always greater than the theoretical value regardless of ventricular weight. For this reason the cellular hyperplasia specifically presents an increase in cellular length beyond the increase in cellular diameter, which is reduced. A multiplication of myocardial nuclei beyond the critical weight was also observed. The results obtained are of physiopathological significance owing to modifications of the capillary network and the interstitial tissues.

The effects of preparative procedures for scanning electron microscopy on the size of isolated lymphocytes.

The diameter of lymphocytes, isolated from a sample of peripheral blood by Ficoll-Hypaque sedimentation, was determined after eight different steps in the preparative procedure for scanning electron microscopy (SEM). There was a 43% total reduction in mean cellular diameter of the lymphocytes studied, the diameter dropping from 8.4 mum prior to fixation, to a final diameter of 4.8 mum in the cells examined under the scanning electron microscope. The bulk of this shrinkage occurred during critical-point drying. In view of this finding, caution should be exercised in describing detailed cell surface morphology by SEM when similar preparative procedures are employed.

Hydrodynamic aspects of protoplasmic streaming inChara braunii

Protoplasmic streaming was investigated in several types of cells fromChara braunii, and the data were subjected to extensive theoretical analysis. The following results were obtained: 1. Streaming velocity is relatively insensitive to cell length if the length/diameter ratio of the cell exceeds five. 2. Most of the viscous loss engendered in the bulk endoplasm and sap is localized near the indifferent lines. 3. The streaming velocity of the bulk endoplasm is directly proportional to the square root of the cellular diameter, and the power input per unit area to the bulk endoplasm is—over a wide range of velocities—independent of velocity. 4. The streaming velocity varies linearly with the temperature, and it is in principle possible to use this variation to determine the temperature variations of both the power input to the bulk endoplasm and an effective viscosity for this endoplasm. Finally, the function of the streaming is considered and several possibilities are discussed.