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The authors describe on the basis of their experience several methods of the removal of temporal bone for research, teaching and autoeducative purposes. Bilateral removal from the same subject is described in detail. A simple, effective and easy preparation of dry anatomical models by means of cadaverous beetles Dermestes vulpinus is reported.
The vomeronasal organ consists of receptor cells of microvillous type, supporting and basal cells. According to their ultrastructural organization the microvillar cells are analogous to those in the main olfactory organ in the pig and have all signs of the receptor cell: microvilli at the top and centrioles in cytoplasm, as well as the central process getting off the cell body. Both in the pig and in the sheep the supporting cells contain in their apical region a number of basal bodies with cilia, getting them off. In the receptor zones of epithelium albuminous glands predominate, in the respiratory zones--mucous ones. A great amount of liquid mucus, excreted on the surface of the epithelium by numerous glands and supporting cells, apparently, facilitates adsorption and desorption of odorous molecules from the receptor cells after their stimulation. The cilia of the supporting cells probably from the stream of the vomeronasal mucus. The cartilagenous torus epithelium of the vomeronasal organ of the pig and sheep has in general a similar structural organization. This demonstrates general for Vertebrata receptor mechanisms of odorous substances, evidently connected with perception of feramones or contact olfaction.
By means of 3H-leucine radioautography, ultrastructural and morphometrical analysis, it has been demonstrated that in the cells of the acinar (Ac) and granular (Gr) parts of the submandibular gland (SMG) in mice with a synchronized for 3 h nutrition cycle there are endogenic fluctuations (for about 1 h) of the secretory process. They are demonstrated as alterations in intensity of protein synthesis in the cells, their areas and ultrastructure. In the Ac cells at the moment of feeding and in 50, 110, 150 min after feeding maximal leucine incorporation is observed. The changes in the cell area during the first hour occurs with 10 minutes' overtake of the incorporation intensity, and during the following 2 h an equilibrium is reached between these two parameters, when the maximal contents of the label corresponds to the minimal area of the cells. In the Gr cells one maximum of 3H-leucine incorporation occurs in 60-80 min after feeding. The minimal content of the label takes place in 10 and 120 min after feeding. During the time mentioned inverse ratio between the intensity incorporation of the labelled isotope and the change of the cell volume is observed. This is connected with autoregulatory processes in the cells. It is possible that in the Ac cells together with removal of the secretory granules by means of exocytosis (in 10-20 min after feeding) the secretory material is removed before it is formed as granules by parvivesicular extrusion. In the Gr cells apocrinic and endocrinic secretion takes place. Presence of certain specific formations (secretory lysosomes) explains peculiarities of the secretory process in the SMG.
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3D Reconstructions from tomographic images are used in the planning of radiation therapy to study important anatomical structures such as the body surface, target volumes, and organs at risk. The reconstructed anatomical models are used to define the geometry of the radiation beams. In addition, 3D voxel models are used for the calculation of the 3D dose distributions with an accuracy, previously impossible to achieve. Further uses of 3D reconstructions are in the display and evaluation of 3D therapy plans, and in the transfer of treatment planning parameters to the irradiation situation with the help of digitally reconstructed radiographs. 3D tomographic imaging with subsequent 3D reconstruction must be regarded as a completely new basis for the planning of radiation therapy, enabling tumor-tailored radiation therapy of localized target volumes with increased radiation doses and improved sparing of organs at risk. 3D treatment planning is currently being evaluated in clinical trials in connection with the new treatment techniques of conformation radiotherapy. Early experience with 3D treatment planning shows that its clinical importance in radiotherapy is growing, but will only become a standard radiotherapy tool when volumetric CT scanning, reliable and user-friendly treatment planning software, and faster and cheaper PACS-integrated medical work stations are accessible to radiotherapists.
In the experiment with 22 dogs the authors have studied the effect of the spine shortening on the undamaged and damaged spinal cord. Observation period ranged from 1 week to 6 months. Partial resection of the vertebral body without spine shortening, practically, have not affected the spinal cord of an animal. Spine shortening without the spine cord transection is accompanied by the spinal cord crumpling and partial damaging. Combination of this operation with submembrane transection of the spinal cord permits to avoid an obvious scar formation but results in considerable cyst-formation that prevents regenerative process in the spinal cord. Further studies should be conducted in terms of the cyst-formation process prevention.
This paper proposes a double porosity model to deal with the mass transfer between capillaries and tissues in the lung microcirculation on the basis of. Utilizing the analytic method of small parameter expansion and the numerical method, the nonlinear governing equations are solved. Comparison shows that the small parameter solution is accurate enough to illustrate the mass exchange between the lung capillary and tissues. Finally the results are used to discuss the mechanism of formation of lung edema.
Problems on correlation of processes of normal histogenesis and those of physiological and reparative regeneration are discussed. A special attention is paid to the cellular-differon organization of tissue and its significance for understanding cellular mechanisms and ultrastructural bases in tissue regeneration after lesions and use of biostimulators of various origin. Certain peculiarities have been revealed in changes of intra- and interdifferon interrelations of cells in various tissues at regenerative histogenesis. The biostimulators applied differently change duration and manifestation of its stages, that is they influence the internal structure of the process and the cellular-tissue composition of the regenerate.
The possibility of using cross-sectional area as a measure of nasal resistance was investigated with an equation based on hydraulic principles that link the area of a constriction in an airway to the pressure gradient and flow rate of air passing through it. Experiments with anatomical models of the nasal cavity confirmed the area of the nasal valve could be measured from simple pressure and flow data with a mean error of 3.5 mm2 (SD = 2.2). The software of a clinical rhinomanometer was then modified to incorporate this equation. Initial tests with a series of substitute airway constrictions of known area indicated the rhinomanometer could then use pressure and flow data to derive the area of each constriction with a mean error of 1.4 mm2 (SD = 0.9). Using this modification during rhinomanometry on 18 adults with subjectively clear nasal airways, a mean value for the narrowest area of the combined nasal cavities was found to be 48 mm2 (SD = 13.7) and results from 17 subjects complaining of nasal obstruction produced a mean narrowest area of 27 mm2 (SD = 11.8). Thus, this system can accurately derive area from data normally gathered from rhinomanometry and the value is constant over a range of pressure gradients and flow rates. The advantages of considering nasal obstruction in terms of area are discussed.
Concern about the amount of radiation received during scoliosis evaluation and treatment led us to measure radiation exposure in an anthropomorphic phantom to determine the increased risk of breast cancer in young women with scoliosis. Assuming that 22 radiographic examinations were performed over the course of scoliosis treatment, the increased relative risk of breast cancer was determined to be 0.22% in these patients.
Dosimetry in photodynamic therapy as currently practiced is empirical in that it does not account for optical properties of the target lesion. However, since light attenuation in tissue is unpredictable, measurements of optical properties are needed to ensure optimal light dose delivery. Further improvements in the uniformity of light dose distribution in tumors can be afforded by implanting multiple light sources. A technique is described in which the use of multiple cylindrical sources was combined with measurements of light energy fluence rate in the tumor. Six sources were placed within translucent plastic needles, which were inserted into tumors in a parallel array. Tumor attenuation characteristics were measured by placing a miniature light detector in one needle, while illuminating a cylindrical source in another, nearby, needle. This process was repeated for different needle pairs. In one postmortem and two in vivo tumors the absorption coefficient, transport scattering coefficient and penetration depth ranged from 0.56-0.81 cm-1, 9.4-15.2 cm-1 and 1.7-2.3 mm, respectively. Apparent penetration depths for in vivo tumors changed with time, during experiments. Predictions of dosimetry were generally consistent with direct measurements of light in tumors. Somewhat better agreement was observed in an optical phantom.
Lung fibrosis is a process in which collagen is laid down and the delicate capillary-alveolar relationship is disturbed. The architectural changes which occur in the capillaries, a main element of the oxygen transferring unit, are difficult to illustrate without a three-dimensional tool, such as scanning electron microscopy. Therefore, a scanning electron microscopic study was undertaken to show the capillary changes of lung fibrosis. Fibrosis was induced in rats by intratracheal instillation of bleomycin. After 30 days the rats were sacrificed, and the vascular tree of the lung was cast with methacrylate. The fibrosis was patchy. The intercapillary space became wider; and some capillaries had large, irregular dilatations. Occasionally giant capillaries (up to 19 mu in diameter) were noted. The pleural and alveolar capillary diameters increased (P less than 0.01), and the branching frequency decreased (P = 0.02). The center of the capillary rings, which has been suggested to be the site of contractile interstitial cells, increased in size (P = 0.03). The appearance of irregularly shaped capillaries and an increase in diameter without a change in density of alveolar capillaries, resulting in a loss of surface area and a decrease in branching, are the main scanning electron microscopic findings of the remodeling which occurs in pulmonary capillaries in lung fibrosis. These changes may partially explain the functional derangement of this disease.
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This investigation studied the influence of changes in velopharyngeal orifice size on vowel intensity in normal speakers when subglottal air pressure was controlled. Controlled variations in velopharyngeal orifice area were achieved by two different methods. The effective velopharyngeal orifice areas introduced into the subjects were verified aerodynamically. A reduction in vowel intensity (SPL) was recorded during the large experimental velopharyngela orifice condition (50 mm2) when compared to a control condition. The clinical implications of these findings are discussed.
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This review traces the efforts of different fields of thermoregulatory modeling. The aims of the three diverging branches can be characterized by (i) insight into functional physiological mechanisms and prediction of physiological phenomena, (ii) prediction of human performance for the protection of industrial workers or military personnel, and (iii) prediction of the impact of accidents, diseases, and clinical treatments. Common current and future efforts may be recognized which improve the physiological quality of the models for purposes either of physiological research itself or of promotion of the field of application, namely, (i) to approach the models to real geometry and anatomy of the human body, (ii) to simulate more adequately heat transport processes induced by the circulating blood, (iii) to implement more sophisticated regulatory concepts, (iv) to take into account interaction with other regulatory systems. "Environmental Ergonomics" should be an adequate forum for linking these diversified fields together.
The deposition efficiency of therapeutic aerosol particles in the human maxillary sinus is evaluated both in the human body and in a model cast of the upper airway. In the experiments, three sample materials, such as mono-dispersed polystyrene latex particles, aqueous glucose solution and pure water, in the range of particle diameter of from 0.5 to 15.8 microns, are employed in the model cast. The radioactive labelled aerosol particle is also used in the human body. From the results of the experiment, it is confirmed that even though the maxillary sinus is a closed hollow organ, aerosol flow is able to be induced only when the pressure gradient is applied between the nasal cavity and the maxillary sinus. In this case, the particle deposition is is explained in relationship to the inertia impaction of the aerosol particles on the inside wall of the maxillary sinus. The total deposition efficiencies and the deposited particle sizes in the sinus area for both experiments, with the model and in the human body, are almost the same at 3%, and 3-10 microns in diameter, respectively. A physical model for this particle deposition suggests that these experimental values change not only with the size distributions of therapeutic particles and the pressure gradient, but also with the diameter of the sinus ostium. Moreover, since the therapeutic particle might not enter the maxillary sinus when the diameter of the sinus ostium canal is less than 1 mm, some pretreatment to open the sinus ostium canal would be necessary before applying such aerosol therapy in practice.