American Journal of Anatomy最新文献

The paracervical ganglia of the female rat were studied to elucidate the variety of neural elements in the ganglia. Light and electron microscopy, histochemistry, and immunohistochemistry were employed to reveal subtypes of neurons; small, intensely fluorescent (SIF) cells; and nerve terminals and to examine the relationships between these elements. On the basis of their histochemical markers, four subtypes of principal neurons were identified: acetylcholinesterase (ACHE)-positive, noradrenergic, neuropeptide tyrosine-immunoreactive (NPY-I), and vasoactive intestinal polypeptide-immunoreactive (VIP-I). The NPY-I neurons appeared to be the most numerous and the noradrenergic the least common type of neuron. Four subtypes of chemically coded SIF cells were revealed: catecholamine-containing, NPY-I, and those immunoreactive for calcitonin-gene-related peptide (CGRP-I) and cholecystokinin-octapeptide (CCK-8-I). The SIF cells were present as single cells among and adjacent to principal neurons and as large clusters near the edges of the ganglia or in nearby nerve trunks. Synaptic contacts on SIF cells, or between SIF-cell processes and neurons, were not observed. Seven subtypes of nerve terminals were stained: ACHE-positive, CGRP-I, CCK-8-I, VIP-I, substance P-I, enkephalin-I, and atrial natriuretic factor-I. Nerve terminals enwrapped the neurons as perineuronal plexuses in synaptic-like relationships. These results demonstrate that the paracervical ganglia of the female rat are a complex system of neural elements. For example, several classes of chemically coded neurons, SIF cells, and terminals exist in the ganglia. Each of these components contains a number of substances, some of which are putative neurotransmitters, which could influence activity in the ganglia or in the effector organs innervated by the ganglia.

The anatomy and histology of the adrenal gland in the adult opossum were found to be typical for mammals. The development of the adrenal medulla was also found to follow the typical mammalian pattern. Primitive sympathetic cells were found in both intra- and extra-adrenal locations in the newborn at a time when chromaffin precursor cells were migrating to the adrenal anlage. Pheochromoblasts first appeared within the forming medulla where at a later stage chromaffin cells could be observed forming columns of cells between adjacent sinusoids. Unlike in other mammals, much of this development takes place postnatally when the neonate is in the mother's marsupium. The value of the developing opossum adrenal medulla as an experimental model is stressed, since a significant amount of development takes place in an environment that is accessible to experimental manipulation.

The myocardium of the Bio 14.6 cardiomyopathic hamster was examined with the electron microscope to identify cellular and organelle changes during the acute lesioning stage, a period typified by concomitant cardiocyte destruction and calcium elevation. Most cardiocytes retained their normal histologic and ultrastructural features, but scattered foci of altered and necrotic cells were observed in association with degenerative calcifying lesions. Prenecrotic alterations of myocytes included cellular edema; varying degrees of distension of sarcoplasmic reticulum and T-tubules; contraction bands and other myofibrillar abnormalities; mitochondrial clustering and hyperplasia; a wide spectrum of mitochondrial changes such as altered sizes, shapes, and cristal patterns, and increases in the number and size of osmiophilic matrix inclusions. Morphologic features consistent with substantial calcium excess were not observed in most altered but prenecrotic cells. Instead, calcium deposition within extruded mitochondria and upon degenerating organelle debris was observed only after cardiocyte disruption. Some calcifying cell remnants were phagocytized by macrophages, whereas large calcified plaques and other deposits remained in the interstitium. Mitochondrial calcification in vascular smooth muscle cells and fibroblasts was evident in highly calcified lesions. These observations suggest that most of the morphologically identifiable calcium deposition present in this cardiomyopathy results from secondary calcification subsequent to sarcolemmal disruption.

This study describes the projection of cervical spinal afferent nerve fibers to the medulla in the brush-tailed possum, a marsupial mammal. After single dorsal roots (between C2 and T1) were cut in a series of animals, the Fink-Heimer method was used to demonstrate the projection fields of fibers entering the CNS via specific dorsal roots. In the high cervical spinal cord, afferent fibers from each dorsal root form a discrete layer in the dorsal funiculus. The flattened laminae from upper cervical levels are lateral and those from lower cervical levels are medial within the dorsal columns. All afferent fibers at this level are separated from gray matter by the corticospinal fibers in the dorsal funiculus. All cervical roots project throughout most of the length of the well-developed main cuneate nucleus in a loosely segmentotopic fashion. Fibers from rostral roots enter more lateral parts of the nucleus, and fibers from lower levels pass to more medial areas; but terminal projection fields are typically large and overlap extensively. At more rostral medullary levels, fibers from all cervical dorsal roots also reach the external cuneate nucleus. The spatial arrangement here is more complex and more extensively overlapped than in the cuneate nucleus. Rostral cervical root fibers reach ventral and ventrolateral areas of the external cuneate nucleus and continue to its rostral pole; more caudal root fibers project to more dorsal and medial regions within the nucleus. These results demonstrate that projection patterns of spinal afferents in this marsupial are similar to those seen in the few placental species for which detailed data concerning this system are available.

Afferent perikarya in dorsal root ganglia (DRG) at the T13 and L1 segmental levels projecting to the rat ovary were identified by utilizing the fluorescent retrograde tracer true blue (TB). Subsequently, TB-labeled ovarian afferent perikarya in DRG were examined for vasoactive intestinal polypeptide (VIP), substance P (SP), cholecystokinin-8 (CCK-8), neuropeptide Y (NPY), and somatostatin (SOM) immunoreactivity and for the presence of fluoride-resistant acid phosphatase (FRAP) enzyme activity. Of the ovarian afferent perikarya at the T13 and L1 segmental levels, 20.5% displayed VIP immunoreactivity, 23.8% displayed SP immunoreactivity, and 43.1% were immunoreactive for CCK-8. No ovarian afferent perikarya contained SOM or NYP immunoreactivity or FRAP activity. It is suggested that different neuropeptides may participate in modulation of specific ovarian functions.

Ultrastructural, histochemical, and freeze-fracture studies of material recovered by bronchoalveolar lavage from patients with pulmonary alveolar proteinosis revealed four types (A, B, C, and D) of multilamellated structures (MS). Type A, the major component, consisted of concentric, trilaminar structures which were composed of two electron-dense layers and a central lucent layer (5.7-7.5 nm in overall width) alternating with wider (25-30 nm) electron-lucent intervening layers. Type B MS were formed by concentric lamellae with a 5-5.3-nm periodicity. Type C MS were composed of wavy, electron-dense lamellae with a 4-4.5-nm periodicity. Type D MS were conglomerated masses of intricately arranged double or triple electron-dense layers (7.5-13.5 nm wide) alternating with wider (30-40-nm) electron-lucent layers. The electron-dense lamellae of type A, type C, and type D MS were stained with ruthenium red, the Thiéry method, and concanavalin A, indicating the presence of carbohydrate components. Freeze-fracture studies revealed smooth inner and outer surfaces in type A MS, with the fracture planes passing through the central parts of the trilaminar structures; the intervening layers contained 10-nm particles, which probably are proteins. Type B MS had smooth surfaces, and type C MS had slightly particulate surfaces; while type D MS showed tubular or polygonal structures, 350 nm wide, with rows of particles 7-8 nm in diameter. It is concluded that type A and type D MS contain proteins and carbohydrates, probably in the form of glycoproteins, as well as phospholipids, and are related to tubular myelin. Type B and type C MS are considered to contain mainly phospholipids; type C MS are also considered to contain carbohydrates and to be related to lamellar bodies of type II alveolar epithelial cells.

Morphometric analysis of human ovarian decidual cells was performed with a Videoplan computer, and mean values were established for the area and perimeter of cellular processes and organelles. Two-hundred forty electron micrographs representing 160 cells were analyzed. The mean decidual cell area was 218.7 microns2, of which 34.5 microns2 was occupied by the nucleus (15.8% of the cytoplasmic area); the nucleus contained 1.74 micron2 of nucleolar material (0.8%). The endoplasmic reticulum occupied 13.63 microns2 (6.2%). Mitochondria occupied 7.3 microns2 (3.3%) and the Golgi network 5.49 microns2 (2.5%). Decidual secretory bodies occupied 0.91 micron2 (0.42%) and cytoplasmic processes 1.89 micron2 (0.94%). The remainder of the cytoplasm, containing inclusions and cytoskeleton, represented 71% of the cell area. Perimeter measurements indicated an average decidual cell was surrounded by 87.8 microns of plasma membrane. The mean nuclear membrane measured 28.3 microns (representing 32.3% of the plasma membrane, pm, or 4.1% of total cellular membranes, cm). Outer mitochondrial membranes measured 156.6 microns (178% pm, 23.5% cm); endoplasmic reticulum membranes measured 350.3 microns (400% pm, 52.6% cm); Golgi membrane measured 30.77 microns (35% pm; 4.5% cm) and membrane surrounding secretory bodies measured 9.8 microns (11.2% pm; 1.4% cm). A mean of 280 secretory bodies per ovarian decidual cell was calculated. The plasma membranes of evaginated cytoplasmic processes represented 22.3% of the total pm (19.6 microns or 2.9% cm). A mean of seven such processes was observed per 87.8 microns of plasma membrane (160/cell). These morphometric data provide a baseline for comparisons of human ovarian decidual cells with uterine decidua, in vivo and in vitro, as well as with decidual cells of other species.

The objective of this experiment was to attempt to induce, with hydroxyurea (HU), significant quantitative differences in the level of DNA-synthetic activity (DNA-SA) between a neoplastic cell population (the Ehrlich ascites carcinoma or EAC) and bone marrow in the same animal. Mice bearing a 5-day-old EAC were standardized to and kept on an LD 12:12 cycle (light 0600-1800 hr). They were treated with 500 mg/kg HU at 0500 hr (23 hr after lights on, or HALO) or at 1700 hr (11 HALO). DNA-SA was determined by liquid scintillation counting of 3H-thymidine incorporation into chemically isolated DNA. DNA-SA in bone marrow and EAC cells was monitored over the next 60 hr with subgroups of ten mice each killed every 3 hr beginning 3 hr after treatment with HU. The circadian system of the host influenced the response of the bone marrow to HU; i.e., the response to HU administered at 0500 hr was different both qualitatively and quantitatively from that for HU given at 1700 hr. Comparisons of DNA-SA in bone marrow and EAC from the same animal revealed time points after treatment with HU when DNA-SA in the EAC was high, but DNA-SA in bone marrow was low. These differences in the level of DNA-SA between a tumor cell population and bone marrow should be of therapeutic value; i.e., executor doses of anti-DNA-SA drugs such as cytosine arabinoside could be given at that point in time after treatment with HU when DNA-SA in the tumor was high, but DNA-SA in the bone marrow was low.

The left atrium of young rats has previously been demonstrated to respond with DNA synthesis and binucleation 11 days after left ventricular infarction. This investigation was designed to examine the hypertrophic response of the left atrial myocyte of the rat at 20 and 60 days after ventricular infarction. Male Sprague-Dawley rats were subjected to left coronary artery ligation (CAL) or sham operation. Following enzymatic separation, left atrial myocytes were examined at 20 and 60 days postoperation for number of nuclei and cellular dimensions (cell length, width and area, and nuclear area). Results demonstrated that the level of binucleation at 20 days (77.3%) and 60 days (71.3%) was nearly twice that observed in sham-operated animals, which were 33.1% binucleated at 20 days and 43.5% binucleated at 60 days. In both mononucleated and binucleated myocytes, the mean lengths, widths, and cell areas from CAL hearts were significantly greater than those of corresponding sham-operated animals. In all cases, these values were larger in binucleated myocytes than in mononucleated cells. The mean area of CAL cells was approximately twice that of sham-operated myocytes. With regard to mean lengths and widths, although both were greater in the CAL animals, there was a decrease in length and increase in width between 20 and 60 days in the CAL group. Mean nuclear areas were significantly greater in CAL myocytes than in those from the sham-operated group. These increases in nuclear number and cellular dimensions of the atrial myocyte are prominent features of the response to the stress imposed by left ventricular infarction.