ISSN:0003-276X    

DOI:10.1002/ar.1092010102

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1981

数据来源: WILEY

摘要:

AbstractPrevious studies have indicated that total nucleolar area and volume remain constant regardless of the number of nucleoli. The question remains whether this relationship is valid for mass. To answer this, total nucleolar mass values were obtained from nuclei of living mesothelial cells in culture possessing one to four nucleoli. The nucleolar mass was calculated using interferometry. The mean total nucleolar dry mass for cells with one, two, three, and four nucleoli was 40 × 10−12gm, 38.4 × 10−12gm, 39.1 × 10−12gm, and 41.4 × 10−12gm, respectively. These data suggest that on the average, each cell had approximately the same total nucleolar dry mass regardless of the number of nucleoli.In an additional study, interferometry was employed to reveal changes in nucleolar mass and concentration during a seven‐hour period. It was concluded that the nucleolus is a dynamic organelle, with its total mass varying in time from an average 40 × 10−12gm with a mean concentration

ISSN:0003-276X    

DOI:10.1002/ar.1092010103

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1981

数据来源: WILEY

摘要:

AbstractThe cell bodies of neurons innervating a rat mandibular molar tooth were examined with respect to their location in the trigeminal ganglion. The study sought to determine if these cell bodies were restricted to a specific somatotopic location within the mandibular territory of the ganglion or if they were distributed throughout the entire mandibular territory. Horseradish peroxidase (HRP) pellets were placed in the cavity preparation of right first mandibular molar teeth for a 24‐hour period. The animals were then perfusion fixed, and the right trigeminal ganglion was removed, sectioned and processed by the tetramethyl benzidine neurohistochemical technic.The four trigeminal ganglia constituting this experimental series demonstrated 129, 185, 236, 318 HRP‐positive cell bodies. These cell bodies were dispersed throughout the extent of the mandibular territory. It was concluded from these observations that the distribution of cell bodies innervating a rat mandibular molar tooth is not restricted to a specific region of the mandibular territory of the trigeminal ganglion, but rather the distribution of these cell bodies is throughout all parts of the mandibular territ

ISSN:0003-276X    

DOI:10.1002/ar.1092010104

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1981

数据来源: WILEY

摘要:

AbstractCells located in the interatrial septum of the ferret heart were examined and mean cell volume, surface area, length, width, as well as cell length/width and surface area/volume ratios were obtained. The muscle cells were from two different regions. One region was the area of the middle internodal tract while the other was from the area where the anterior and middle internodal tracts intermingled. Based on the data obtained, at least two different subpopulations of interatrial muscle cells could be defined. The larger cells had a mean cell length of 109.7 μm, a mean cell width of 13.1 μm, a length/width ratio of 8.61, a mean cell surface area of 5,057.6 μm2, a mean cell volume of 5960.8 μm3, and a surface area/volume ratio of 0.87. The smaller cells had a mean cell length of 58.0 μm, a mean cell width of 12.2 μm, a length/width ratio of 4.85, a mean cell surface area of 2494.1 μm2, a mean cell volume of 2553.6 μm3, and a surface area/volume ratio of 1.00. The large cell population had cells that were myofibril rich and also others that were myofibril poor. These quantitative data indicate that the regions of internodal pathways are not composed of a single specialized cell type, but rather are composed of at least two, if not more, cell types that intermingle with eac

ISSN:0003-276X    

DOI:10.1002/ar.1092010105

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1981

数据来源: WILEY

摘要:

AbstractThere have been advances in electrophysiology which have necessitated a more thorough semi‐quantitative analysis of the entire conduction system to yield data useful for correlation purposes. Thus an attempt is made to modify and expand our previous method of studying the conduction system pathologically. This method thus includes the study of the sinoatrial (SA) node and its approaches, the atrial preferential pathways, the approaches to the atrioventricular (AV) node, the AV node, the penetrating and branching portions of the AV bundle, the bundle branches, the peripheral Purkinje nets, and the remainder of the atrial and ventricular myocardium.The SA node and its approaches are studied in a longitudinal manner. This gives a better insight into the pathologic changes than does a study in the transverse direction. The approaches to the AV node, bundle and bundle branches are studied in an oblique manner, rather than horizontally apicalward, or from the posterior to the anterior septal region. The horizontal manner does not give sufficient sampling of the AV node and bundle unlesscompleteserial sections are made. Sectioning from the posterior to the anterior septal wall makes difficult an evaluation of the right bundle branch.In conduction system correlation with Wolff‐Parkinson‐White and Lown‐Ganong‐Levine syndromes complete serial sectioning of both AV rims is advisable. Where complete serial sectioning is impossible in large adult hearts, retaining every fifth section may be permissable. In the study of congenitally abnormal hearts, it is advisable to embed the entire heart as a unit. If that is impossible because of the size of the heart, then very careful judicious planning of the fashioning of the blocks is necessary, so that displaced SA nodes, and anterior AV nodes and bundles are not o

ISSN:0003-276X    

DOI:10.1002/ar.1092010106

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1981

数据来源: WILEY

摘要:

AbstractHistochemical reactions which demonstrate cholinesterase reactions in tissues were used for slides of serial frozen sections of hearts of pigs, dogs, and rats to determine whether there are special types of modified muscle cells in continuous pathways from the SA (sinoartial) to the AV (atrioventricular) node. There were positive reactions for acetylcholinesterase with less reaction for butyrl cholinesterase in ganglion cells and nerve fibers. No continuous pathways of cholinesterase‐reacting cardiac muscle fibers from the SA to the AV node were identified although the muscle fibers were in intimate relation with the nerve fibers. No cells of Purkinje type were demonstrated in the atri

ISSN:0003-276X    

DOI:10.1002/ar.1092010107

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1981

数据来源: WILEY

摘要:

AbstractA canine model of chronic myocardial infarction has been studied in which animals are susceptible to the initiation of sustained ventricular tachyarrhythmias using routine methods of programmed stimulation. The pacinginduced arrhythmias in this model are similar to those observed in man in their mode of initiation and termination, as well as in their response to both pacing and pharmacologic interventions. Indirect evidence has suggested a localized protected reentrant mechanism for these arrhythmias. The susceptibility to arrhythmia initiation in this model has been related to both electrophysiologic and histopathologic findings. Consistently, animals have demonstrated a marked heterogeneity of local properties of excitability and refractoriness at sites within areas of infarction. Correspondingly, animals have shown a marked inhomogeneity of histopathologic findings within areas of infarction, with close interspersing of normal and abnormal myocardium. Remarkably, even animals with small mottled infarctions, often less than 1 cm × 2 cm and electrocardiographically silent, were highly susceptible to the initiation of ventricular tachyarrhythmias, and especially fibrillation. Thus, initial provocative studies in this model have suggested its potential importance both in studying arrhythmia mechanisms and in evaluating the efficiency of potential antiarryhthmic interventions. In addition, this should be an ideal model in which to correlate pathophysiologic and morphologic alterations in the setting of chronic myocardial infarction

ISSN:0003-276X    

DOI:10.1002/ar.1092010108

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1981

数据来源: WILEY

摘要:

AbstractSome effects of undernutrition were noted in the brains of 21‐day‐old rat pups undernourished from birth by being reared by nursing dams fed on a low protein diet. As compared to the normally fed control pups, the body weight, brain weight, and thickness of the parietal neocortex and paravermal cerebellar cortex were significantly lower in the undernourished pups (p<0.001), while the thickness of the cortices of the dentate gyrus and hippocampus CA3 only reached significance at the 5% level. Again, as compared to the control pups, the number of spines per unit length on the distal dendritic segments of the pyramidal cells of lamina III of the parietal neocortex and of the hippocampus CA3 reached significance at the 5% level whereas that of the granule cells of dentate gyrus and Purkinje cells of the paravermis did not reach significance at the 5% level. The myelination of the pyramidal tract and spinal trigeminal tract in the lower medulla was less advanced in the undernourished pups.To date, the demonstration of precise functional correlates for the observed changes of morphological and physiological parameters in animals subjected to undernutrition has been elusive. An approach that may lead to unraveling this problem is suggested in a discussion of relating sources of input to the specific dendritic segments where the spine counts were m

ISSN:0003-276X    

DOI:10.1002/ar.1092010109

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1981

数据来源: WILEY

摘要:

AbstractThe anatomical substrates of internodal conduction have long been a contentious topic. Debated first by the German Pathological Society in 1910, the consensus of established opinion for over half a century was that conduction between sinus and atrioventricular nodes occurred through plain myocardium. This was a conclusion supported by Truex in 1961. Despite his restatement of this fact in 1976, it has become fashionable to describe internodal conduction as being mediated by specialized internodal pathways. To reinvestigate this problem we studied 22 human fetal and 32 human infant hearts. In each case it was possible to cut the atrial tissues as a single block of tissue and to examine serial sections through the internodal myocardium. The sinus node, atrioventricular node, and segments of atrioventricular ring specialized tissue were recognized as specialized tissue using the light microscope in each heart. In contrast, there was nothing “special” about the myocardium between the nodes, nor was it possible to recognize tracts on the basis of either histological appearance or cellular architecture. It is concluded that, from the standpoint of light microscopy, there is no evidence whatsoever to support the purported concept of specialized anatomical substrates for internodal conduct

ISSN:0003-276X    

DOI:10.1002/ar.1092010110

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1981

数据来源: WILEY

摘要:

AbstractThis 4‐year‐old male child was diagnosed at birth as having several minor congenital anamolies. X‐rays taken during the first year of his life showed a single, massively dilated loop of bowel in the upper abdomen, not appreciated at the time.In 1980 he was admitted to Jackson Memorial Hospital with the diagnosis of small bowel obstruction. An upper gastrointestinal series showed one tremendously dilated loop of distal ileum. At laparotomy, the patient was found to have extreme segmental dilatation of one loop of distal ileum which ended abruptly; there was no evident external cause for obstruction.The resected loop contained in excess of 200 cc of watery brown liquid. The mucosal folds and underlying smooth muscle bundles, in the dilated portion only, were not arranged circumferentially but rather in a distinctive finger‐print‐like pattern with trifurcations, whorls, and intricate interdigitations which had probably produced contractions of a circus type rather than normal peristalic waves.We have been able to find only three reports in the literature in which, as was the case here, the so‐called “giant Meckel's diverticulum” presented as a single tremendously dilated segment of ileum, sharply demarcated at its distal end. In none of them is there any description of the orientation of muscle bundles. We believe that the abnormal arrangement of smooth muscle in the muscular coat in this specimen, and perhaps in the others, probably represents the underlying cause for the extreme local

ISSN:0003-276X    

DOI:10.1002/ar.1092010111

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1981

数据来源: WILEY