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Biomedical subjects

Y Kameda

Publications and source records attributed to Y Kameda.

At least 109 records · Page 6Linked to original sources
PubMed1994

Long-term outcome of myocardial revascularization in patients with Kawasaki coronary artery disease. A multicenter cooperative study.

The long-term outcome of myocardial revascularization by coronary artery bypass grafting in patients with severe coronary obstruction caused by Kawasaki disease is largely unknown. A multicenter follow-up study was performed in 1991. A total of 168 patients with Kawasaki disease (127 male [75.6%] and 41 female patients [24.4%]) who had undergone coronary bypass grafting were enrolled. Obstructive coronary artery disease affected the left main trunk in 11.8%, the right coronary artery in 77.6%, the left anterior descending in 87.6%, and the left circumflex in 25.9%. Old myocardial infarction was noted in 46.0% of the patients. Fifty-four patients (32%, 12.4 +/- 9.8 years) underwent bypass grafting with saphenous vein grafts alone. The remaining 114 patients (68%, 9.8 +/- 7.1 years) received at least one internal thoracic artery graft to the left anterior descending coronary artery. Gastroepiploic artery grafts were used in 12 patients. There were no significant differences between the saphenous vein and internal thoracic artery groups in the mean age at operation (12.4 versus 9.8 years), female ratio (22% versus 25%), the number of patients over 20 years of age (9.3% versus 9.6%), previous history of infarction (51.9% versus 41.2%), impaired left ventricular function (ejection fraction < 0.5) (13.0 versus 11.4%), left main trunk disease (11.1% versus 10.5%), the number of vessels involved (2.2 +/- 0.8 versus 2.0 +/- 0.6 per patient), or the mean number of grafts used (1.7 +/- 0.7 versus 1.7 +/- 0.7 per patient). The operative death rate was also the same in the two groups (1.9% versus 0%), but the late cardiac death rate was significantly higher in the saphenous vein graft group (13.0%) than in the internal thoracic artery group (0.9%) (p < 0.003). Actuarial analysis showed a significantly higher survival in the internal thoracic artery group (98.7% +/- 1.2% versus 81.6% +/- 7.0%, p < 0.05) at 90 months after the operation. Late death was strongly related to the absence of an internal thoracic artery graft (p < 0.003) and to the age at the time of operation (p < 0.05). The actuarial patency rate was significantly higher for arterial grafts (77.1% +/- 1.1%, n = 151) than for vein grafts (46.2% +/- 6.3%, n = 126) 85 months after the operation (p < 0.003). Arterial grafts were used for the non-left anterior descending coronary arteries in only 41 of 155 grafts (26.5%); in contrast, vein grafts were used in 85 of 133 grafts (63.9%) (p < 0.005 to 0.001).(ABSTRACT TRUNCATED AT 400 WORDS)

Actuarial Analysis↗
PubMed1993

Immunohistochemical localization of a neuron-specific beta-tubulin isotype in the developing chicken ultimobranchial glands.

The localization of a neuron-specific beta-tubulin isotype in the ultimobranchial glands from chickens at various stages of development was studied by means of light- and electron microscopic immunohistochemistry with a monoclonal antibody (TuJ1) against the beta-tubulin isotype, c beta 4. At 8 days of incubation, many C cells in the ultimobranchial glands showed immunoreactivity for TuJ1 invariable degrees, weak to intense. At 12 days of incubation, a vast majority of C cells were intensely immunoreactive for TuJ1, and further TuJ1-immunoreactive nerve fibers were distributed in the ultimobranchial glands. At 14 and 16 days of incubation, intense immunoreactivity for TuJ1 was sustained in the C cells. Electron microscopic analyses revealed that TuJ1 immunoreactivity was diffusely distributed throughout the cytoplasm and also localized on the secretory granules of C cells at these stages. TuJ1 immunoreactivity in the C cells started to decrease at late stages of embryonic development. At the hatching period, dense distributions of TuJ1-immunoreactive nerve fibers were observed in the ultimobranchial glands, whereas TuJ1 immunoreactivity of the C cells became very weak. In 10-day-old chickens, TuJ1 immunoreactivity was restricted to the nerve fibers.

Animals↗
PubMed1993

Electron microscopic study on the development of the chicken ultimobranchial glands, with special reference to innervation of C cells.

The development of chicken ultimobranchial glands was studied by electron microscopy. As early as at 8 days of incubation, some cells contained a few secretory granules, although most of the ultimobranchial cells were undifferentiated. Single axons or small bundles of axons were occasionally detected in close contact with the ultimobranchial cells. Subsequently, immature C cells gradually increased in number with age. At 12 days of incubation, the developing C cells, which contained some secretory granules from 60 to 200 nm in diameter, occupied the greater part of the gland. The cells were oval, elongated or irregular in shape and frequently gave rise to long cytoplasmic processes that touched other C cells. Numerous axons enveloped with Schwann cell processes occurred in close vicinity to C cells. At 14 days of incubation, the cytoplasmic processes of C cells reached their maximum number and size. Desmosome-like membrane specialization was observed at the contact between the processes and cell bodies of other C cells, while numerous microtubules were arranged in parallel to the long axes of the processes, and secretory granules were distributed along them. Thus, the C cells at these stages seem to regulate other homologous cells by direct contact. Axon terminals, which contained small, clear and large, dense-cored vesicles, were first found in direct contact with the surface of C cells in 14-day-old embryos. Subsequently, the cytoplasmic processes of C cells progressively decreased, while nerve fibers continued to increase in the ultimobranchial glands. At the late stages of embryonic development, many C cells displayed an oval outline and increased number and size of secretory granules. At hatching, many C cells were filled with large secretory granules ranging from 200 to 700 nm in diameter (average 300 nm). Some cells were still elongated or irregular in shape and contained small secretory granules, 60-200 nm in diameter.

Animals↗
PubMed1993

Staining of pancreatic centroacinar cells, liver bile canaliculi and testicular Leydig cells with a monoclonal antibody against adrenocortical cells.

The immunoreactivity of a monoclonal antibody against cell suspensions from guinea pig adrenal glands was examined at light- and electron-microscopic levels. In addition to the cell surface membrane of adrenocortical cells, the antibody labeled specific sites in the pancreas, liver and testis, but did not label any of the other tissues examined. In the pancreas, microvilli-like processes and the cell surface membrane of centroacinar cells were immunoreactive to the antibody. The microvilli of interlobular duct cells and pancreatic duct cells were also immunoreactive. In the liver, bile canalicular microvilli of hepatocytes were exclusively labeled. Membrane structures of cell organelles, mainly mitochondria, in testicular Leydig cells were also labeled. Immunoblot analysis showed that the monoclonal antibody bound to two common bands at molecular weights of approximately 62 kDa and 110 kDa in the pancreas, liver, testis, and adrenal gland. The two bands reacted with the digoxigenin-conjugated lectin, Sambucus nigra agglutinin (SNA), which recognizes sialic acid linked alpha (2-6) to galactose. Reaction patterns of SNA in the pancreas, liver and testis were similar to those of the monoclonal antibody; pancreatic centroacinar cells and interlobular duct cells, hepatocyte bile canaliculi and testicular Leydig cells were densely stained with SNA. Thus, the monoclonal antibody recognizes two common membrane glycoproteins containing sialic acids in the pancreas, liver, testis and adrenal cortex.

Adrenal Cortex↗
PubMed1993

Immuno-electron-microscopic localization of enkephalin in the secretory granules of C cells in the chicken ultimobranchial glands.

In the chicken, enkephalin-immunoreactive cells and nerve fibers are distributed in the ultimobranchial glands, which consist of C-cell groups and cyst structures. Ultrastructural features of the enkephalin cells and nerve fibers were examined by immuno-electron microscopy using both the streptavidin-biotin-peroxidase method and the protein A-colloidal gold method. Immunoreactivity for enkephalin was located on the secretory granules of C cells. In 1-day-old chickens, three types of C cells were distinguished on the basis of their granule size. Type-I cells were filled with large secretory granules (200-600 nm in diameter). These elements represented a majority of the C-cell population. Type-II cells contained medium-sized granules (100-280 nm in diameter). Type-III cells displayed small secretory granules (60-200 nm in diameter). The latter cells were elongate or irregular in shape and frequently extended cytoplasmic processes into the connective tissue stroma or contacted other C cells. Enkephalin-immunoactivity was revealed by dense deposits of immunogold particles on the secretory granules of type-II and type-III cells. There were only a few type-I cells showing immunoreactivity for enkephalin. A double immunogold labeling procedure demonstrated that calcitonin and enkephalin were colocalized in the same secretory granules of type-I and type-II cells. Type-III cells were devoid of immunoreactivity for calcitonin. Enkephalin-immunoreactive nerve fibers were characterized by the presence of granular vesicles, 60-160 nm in diameter, and frequently established direct contact with the surface of C cells.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1993

A comparative study of vascular proliferation in brain metastasis of lung carcinomas.

Because of the marked vascular proliferation seen in brain metastases of small cell carcinoma of the lung (SCCL), we studied the morphometric and immunohistochemical characteristics of proliferating vessels in metastases from 20 autopsy cases of SCCL with brain metastasis. These were compared with those in surgically resected brain metastases of lung carcinomas, including 6 cases of SCCL, 19 cases of adenocarcinoma and 5 cases of squamous cell carcinoma. Angiogenesis in the tumours was scored by the microscopic angiogenesis grading system (MAGS). The MAGS score for autopsy and surgical metastatic lesions was highest in SCCL. Histologically, many vascular glomeruloid structures were formed in the brain metastases of SCCL, and immunohistochemistry revealed that these lesions were composed of proliferating endothelial cells and pericyte/smooth muscle cells. Immunostaining for basic fibroblast growth factor, a potent angiogenic factor, showed immunoreactivity in the tumour cells, regardless of histological type, and in the surrounding glial cells. Complex autocrine and paracrine phenomena participate in the development of metastatic cerebral lesions with vascular proliferation.

Adenocarcinoma↗
PubMed1993

Exercise coronary flow reserve of bilateral internal thoracic artery bypass grafts.

We attempted to quantify the exercise coronary flow reserve in 20 patients with bilateral internal thoracic artery grafts to the left coronary arteries (group I) who had complete revascularization. The coronary sinus blood flow was measured by the continuous thermodilution method both at rest and during exercise (50 W for 8 to 9 minutes) approximately 1 month after the operation. These results were compared with 30 patients treated with an internal thoracic artery and saphenous vein grafts to the left coronary arteries (group II) and 9 patients with saphenous vein grafts alone to the left coronary arteries (group III). There were no differences among the three groups in age, sex, number of vessels involved, heart rate, double products, left ventricular (LV) end-diastolic pressure, LV ejection fraction, LV end-diastolic volume, or LV mass at the time of study. None of the 59 patients in the study had abnormally enlarged LV end-diastolic volume or increased LV mass. The postoperative coronary sinus blood flow per 100 grams of LV mass at rest was similar among the three groups (73.0 +/- 28.4 mL/min per 100 g LV mass in group I, 73.4 +/- 31.1 mL/min per 100 g LV mass in group II, and 75.9 +/- 28.5 mL/min per 100 g LV mass in group III [not significant]) and significantly (p < 0.01) increased by exercise, although the differences between groups during exercise were not significant (158.9 +/- 45.9, 153.5 +/- 72.1, and 148.3 +/- 60.0 mL/min per 100 g LV mass, respectively [not significant]).(ABSTRACT TRUNCATED AT 250 WORDS)

Blood Pressure↗
PubMed1993

Production of a monoclonal antibody against cell-surface glycoprotein of guinea pig adrenocortical cells.

A monoclonal antibody (MAb) that reacted with the cell-surface antigens of adrenocortical cells was generated against cell suspensions from guinea pig adrenal glands. Cell-surface membranes of the adrenocortical cells in all zones, i.e., zona glomerulosa, zona fasciculata, and zona reticularis, were labeled with the antibody. Adrenal medulla remained unlabeled. Immunoelectron microscopy showed that entire plasma membranes, i.e., plasma membranes between adjacent cells and free cell-surface membranes, including sinusoidal microvilli, were immunoreactive to the antibody. Immunoblot analysis demonstrated that the antibody bound to two prominent bands at molecular weights of approximately 62,000 and 110,000. Two bands were stained with lectin-digoxigenin conjugates. The 110 KD band reacted with Datura stramonium (DSA) and Maackia amurensis (MAA) agglutinins, indicating the presence of N-acetyl-glucosamine and sialic acid-linked alpha (2-3) to galactose; the 62 KD band reacted with SNA, indicating the presence of sialic acid-linked alpha (2-6) to galactose. In adrenocortical cells, the reaction pattern of Sambucus nigra (SNA) agglutinin was similar to that of the (MAb), whereas reaction patterns of DSA and MAA were different. Both neuraminidase digestion and prior absorption of the antibody with N-acetyl-neuraminic acid completely prevented the immunolabeling of adrenocortical cells. These results indicate that the MAb mainly recognizes the 2-6 sialylated cell-surface antigen of adrenocortical cells.

Adrenal Cortex↗
PubMed1993

[Cardiac function following left ventricular aneurysm repair--comparison between patch reconstruction and direct closure methods].

Left ventricular function was compared between two groups of patients who underwent patch reconstruction or direct closure of the ventricular wall following resection of a post-infarction left ventricular aneurysm (LVA). There were 15 and 9 patients in the respective groups. Coronary artery bypass grafting was additionally performed in 8 patients (53%) in the patch reconstruction group and 5 patients (56%) in the direct closure group. The size of the patch used for patch reconstruction (including the suture line) was 57 +/- 19% of the resected area. Before and 1-2 months after surgery, equilibrium RI angiography and cardiac catheterization were performed to assess the following hemodynamic parameters: ejection fraction (EF) at rest and during exercise, left ventricular end-diastolic pressure (LVEDP), left ventricular end-diastolic volume index (LVEDVI), cardiac index (CI) and mean pulmonary artery pressure (m-PAP). Preoperatively, there were no differences in each parameter between the two groups. Postoperatively, there were significant improvements in the EF at rest and during exercise (p < 0.01), LVEDVI (p < 0.01) and the LVEDP (p < 0.05). However there no significant changes in CI or m-PAP following the operation. There were also no significant differences observed in the postoperative values between the two groups. However, based upon postoperative left ventriculograms, patch reconstruction was significantly superior to direct closure for reconstruction of a septal aneurysm.

Aged↗
PubMed1993

[A case report of an advanced esophageal carcinoma treated by neoadjuvant chemotherapy (CDDP + 5-FU) and evaluation of effect on metastatic lymph nodes].

A 69-year-old woman was diagnosed to have type 2 advanced esophageal carcinoma measuring Im 9 cm by X-ray and endoscopic examination. CT scan revealed much swelling of No. 106 and 9 lymph nodes. As the patient had dry cough and these lymph nodes, we tried neoadjuvant chemotherapy for reduction of metastatic lymph nodes. The regimen consisted of CDDP 80 mg/m2 (day 1), 5-FU 800 mg/m2 (day 1-4, continuous). After 2 courses, an operation was performed. Histopathological examination of the section of the primary tumor revealed that only a few cancer cells nests (sq. c.c., mod.) remained in the muscle layer. In 41 dissected lymph nodes, 12 lymph nodes had metastatic cancer cell nests before neoadjuvant chemotherapy and only 4 lymph nodes had a few remaining cancer cells nests. The effect of CDDP + 5-FU therapy is the same for primary tumor and lymph nodes.

Aged↗
PubMed1993

[Late results of aortic valve plasty (aortic leaflet slicing) simultaneously performed with mitral valve surgery].

We followed the course of 20 patients who underwent aortic valve plasty (AVP) combined with mitral valve surgery for rheumatic mild aortic valve disease in association with severe mitral valve disease. At operation, all patients underwent aortic leaflet slicing with a knife, and aortic commissurotomy were performed additionally in 10 patients. After surgery, the degree of aortic valve regurgitation and the amplitude of aortic leaflet motion were assessed chronologically, using ultrasound cardiography. One month after surgery, all but one patients showed a reduction in regurgitation to degree I or less. From the third post-operative year, however aortic valve regurgitation tended to increase again. However, the post-operative degree of regurgitation was observed not to be severer than the pre-operative degree of regurgitation, and no patients showed aggravation of aortic valve regurgitation attributable to exacerbation of mitral valve disease. We divided the patients into two groups according to improvement of aortic valve regurgitation. In the group where the degree of regurgitation returned to the pre-operative one, the degree of amplitude of leaflet motion began to reduce from the third post-operative year and was nearly equal to the pre-operative one at the fifth post-operative year. The results of this study can be summarized as follows: 1. From the third post-operative year, aortic regurgitation was aggravated and aortic valve motion amplitude decreased. 2. The number of sliced valve leaflets and incised commissures did not correlate well with the post-operative reduction in regurgitation.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

Production of monoclonal antibodies against a novel glycoprotein synthesized and secreted by dog thyroid C-cells.

A monoclonal antibody (MAb) that reacted only with thyroid C-cells was raised against cell suspensions from dog thyroid glands, to examine a glycoprotein secreted by C-cells. After chronically-induced hypercalcemia and administration of an anti-thyroid drug, reaction products for the antibody markedly decreased in C-cells, coinciding with alterations in calcitonin immunoreactivity. The antigen recognized by the MAb appears to be a secretory protein. The MAb reacted with C-cells from a wide variety of mammalian species, including rats, mice, hamsters, cattle, cats, rabbits, and monkeys. Furthermore, tumor cells of human medullary thyroid carcinoma, which is derived from C-cells, were immunoreactive to the MAb. Exceptionally, C-cells from guinea pigs and pigs were not stained with the MAb. No crossreactivity was observed in any of the dog tissues examined. Immunoblot analysis demonstrated that the MAb recognized a single prominent band at a molecular weight of approximately 79,000. The 79 KD band reacted with various digoxigenin-labeled lectins, including GNA, DSA, SNA, and MAA; it is a glycoprotein containing mannose, N-acetylglucosamine, and sialic acid. Dog thyroid C-cells were also densely stained with these lectins. The results indicate that thyroid C-cells synthesize and secrete a specific glycoprotein in addition to peptide hormones.

Acetylglucosamine↗
PubMed1992

Enzymatic synthesis of glucoside derivatives of validamine and valienamine.

alpha- And beta-glucoside derivatives of validamine and valienamine were prepared by enzymatic transglucosidation using alpha- and beta-glucosidase of Rhodotorula lactosa. The structures of these derivatives have been elucidated by 13C- and 1H-nuclear magnetic resonance spectral analysis. Thus, 7-alpha-glucoside, 7-alpha-isomaltoside, and 4-alpha-glucoside of validamine and 7-alpha-glucoside, 7-alpha-isomaltoside, 4-alpha-glucoside, and 4-alpha-isomaltoside of valienamine were obtained from maltose and validamine or valienamine using alpha-glucosidase. 7-beta-glucoside, 2-beta-glucoside, and 4-beta-glucoside of validamine or valienamine were obtained from cellobiose and validamine or valienamine using beta-glucosidase. These derivatives were tested for alpha-glucosidase inhibitory activity on rat small intestinal glycosidases.

Animals↗
PubMed1992

A quantitative study of postoperative luminal narrowing of the internal thoracic artery graft in coronary artery bypass surgery.

We used quantitative angiography to determine the postoperative diameter of the internal thoracic artery graft at the point close to the anastomosed site in 147 patients who received the graft for the left anterior descending coronary artery. We performed generalized multiple linear regression analysis (Type I quantification method) to assess the effects of the following factors on the internal thoracic artery graft diameter: age, gender, time of angiography, laterality of the internal thoracic artery used, presence of an undivided major side branch of the internal thoracic artery, presence of a saphenous vein graft having blood flow competition with an internal thoracic artery graft, presence of distal stenosis of the recipient left anterior descending coronary artery, severity of postoperative left anterior descending coronary artery stenosis, and presence of coronary risk factors. The standardized category scores for 25% left anterior descending coronary artery stenosis, 50% left anterior descending coronary artery stenosis, and presence of a saphenous vein graft having blood flow competition with an internal thoracic artery graft were -1.418, -0.767 and -0.622, respectively. Thus, the internal thoracic artery diameter was smaller in patients with well-preserved flow of the recipient coronary artery. The internal thoracic artery diameter had a particularly strong correlation with the degree of left anterior descending coronary artery stenosis (partial correlation coefficient: 0.670). The other factors seemed to have little or no correlation with the postoperative internal thoracic artery diameter. With the criterion that the internal thoracic artery diameter below 1.0 mm represents the "string sign" of internal thoracic artery graft, this phenomenon was observed in nine patients (6.1%). In all of these patients, left anterior descending coronary artery flow was well-preserved, and no ischemia was disclosed in the left anterior descending coronary artery-perfused area. These results indicate that internal thoracic artery grafts have flow adaptability responding to the flow demand of the recipient coronary artery and that the string sign of internal thoracic artery grafts is mainly an outcome of its physiologic characteristics.

Adult↗
PubMed1992

[A case of mediastinal seminoma which penetrated pericardium and invaded left upper lobe].

A 35-year-old man admitted at our hospital, with a complaint of anterior chest pain. Chest x-ray film and CT showed an anterior mediastinal tumor. An invasive thymoma was suspected by the biopsy specimen, invading left upper lobe of the lung. Resections of the tumor, thymus, invasion to the part of the left upper lobe and the pericardium were performed. The pathology showed pure seminoma penetrating the pericardium. As testis and the retroperitoneum were normal, the tumor was diagnosed as mediastinal origin. Adjuvant chemotherapy (CDDP, BLM and etoposide) and irradiation were performed. The patient is alive and well for 7 months postoperatively.

Adult↗
PubMed1992

[Aortic valve replacement with fresh or cryopreserved aortic allograft--initial experience in Japan].

Aortic allograft valves were harvested from non-infected (bacterial or viral) cadavers within 24 hours of death with a family consent, and were sterilized by 4 degrees C antibiotic solution for 48 hours. Then, the allograft was preserved in the 4 degrees C nutrient medium (fresh; TC-199, calf serum and HEPES buffer) or in liquid nitrogen (-196 degrees C) after freezing to -80 degrees C by a programmed freezer. 10% dimethylsulfoxide (DMSO) was used for cryopreservation. Following germ-free confirmation, aortic allograft valves were implanted in 5 patients having aortic regurgitation with good results. Three fresh and two cryopreserved allograft valves were used. Although the follow-up term is very short (maximum 1 year) at the present time, the valve function is quite satisfactory, confirmed by cardiac catheterization and echocardiography. This is the first report in Japan with regard to cryopreservation of allograft valves and clinical use of fresh or cryopreserved valves. We believe that realization and progress of allograft preservation by cryo-technique and establishment of the tissue bank are important for the development of cardiovascular surgery in Japan.

Adult↗
PubMed1991

Immunocytochemical localization and development of multiple kinds of neuropeptides and neuroendocrine proteins in the chick ultimobranchial gland.

The ultimobranchial gland is an endocrine organ consisting of C cell groups. In chickens, the glands are richly supplied by nerve fibers immunoreactive for neurofilaments. It was found by immunocytochemical staining that C cells of chick ultimobranchial glands showed immunoreactivities for multiple kinds of neuropeptides and neuroendocrine proteins in addition to calcitonin, i.e., calcitonin gene-related peptide (CGRP), somatostatin, neurotensin, chromogranin A, and tyrosine hydroxylase. Furthermore, enkephalin-immunoreactive cells that showed long cytoplasmic processes and large cell bodies, being distinct from the C cell feature, were detected. The densities of these cells per unit area of ultimobranchial gland were assessed using computer-assisted image analysis system; calcitonin cells were 42.9 +/- 10.0%; CGRP cells 26.9 +/- 5.6%; neurotensin cells 8.6 +/- 6.9%; somatostatin cells 3.1 +/- 1.4%; chromogranin A cells 11.8 +/- 1.8%; tyrosine hydroxylase cells 10.0 +/- 5.2%; enkephalin cells 2.9 +/- 1.3%. Dense distributions of peptidergic nerve fibers were also detected in chick ultimobranchial glands. Numerous varicose fibers immunoreactive for substance P were distributed in the close vicinity to C cell clusters and blood vessels. Enkephalin-immunoreactive fibers were also prominent around C cell clusters. Galanin-, vasoactive intestinal peptide (VIP)-, and tyrosine hydroxylase-immunoreactive fibers were distributed around blood vessels only. Subsequently, the ontogeny of these neuropeptides, neuroendocrine proteins, and peptidergic innervations was examined in chickens at various developmental stages. In 10-day-old embryos, weak to moderately intense immunoreactivity for calcitonin was already present in almost all C cells. Immunoreactivities for somatostatin, CGRP, and tyrosine hydroxylase began to appear at this age. At 12 days of incubation, substance P-immunoreactive fibers were first detected in the parenchyma of ultimobranchial glands. Considerable numbers of enkephalin-immunoreactive fibers and cells were also observed. At 14 days of incubation, the largest populations of somatostatin- and enkephalin-immunoreactive cells were attained; the densities of somatostatin- and enkephalin-immunoreactive cells per unit area were 21.2 +/- 3.2% and 12.9 +/- 3.1%, respectively. Substance P-immunoreactive fibers became numerous throughout the gland at this age. Thereafter, calcitonin-, CGRP-, tyrosine hydroxylase-immunoreactive cells progressively increased in number with embryonic age, whereas somatostatin- and enkephalin-immunoreactive cells started to decrease. Chromogranin A- and neurotensin-immunoreactive cells began to appear at 16 days and 18 days of incubation, respectively. Galanin-, VIP-, and tyrosine hydroxylase-immunoreactive fibers were inconspicuous during embryonic life.

Animals↗