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D J Bird

Publications and source records attributed to D J Bird.

34 records · Page 2Linked to original sources
PubMed1988

Localisation and identification of melanocyte-stimulating hormones in the fish brain.

The existence of melanocyte-stimulating hormone (MSH) in fish brains was investigated by a range of techniques: radioimmunoassay, HPLC, bioassay, and immunocytochemistry. Immunoreactive alpha MSH (ir alpha MSH) was detected by radioimmunoassay in all regions of carp and trout brains, with the highest concentration in the basal hypothalamus. In trout, ir alpha MSH cell bodies were located by immunocytochemistry only periventricularly, in the medial basal hypothalamus near the third ventricle, whereas in the carp ir alpha MSH staining was seen both in periventricular cells and also in some of the magnocellular neurones in the lateral hypothalamus. When white-adapted fish were transferred to a black tank for 6 days, the melanin-concentrating hormone (MCH) content of the basal hypothalamus of both carp and trout increased 2- and 4.6-fold, respectively, but the alpha MSH content did not change in either species. Analysis by HPLC of pituitary gland, hypothalamic, and optic tectal extracts revealed that the pituitary contains desacetyl, monoacetyl, and diacetyl alpha MSH, although the ratio of these forms differed in the two species. The hypothalamus and optic tectum, however, contained predominantly the desacetyl form of alpha MSH. Bioassays for MSH in the HPLC fractions revealed the existence of presumptive beta MSH in both the pituitary and hypothalamus. An argument is advanced that the periventricular ir alpha MSH neurones are homologous with the proopiomelanocortin cells of the arcuate nucleus in mammals, and that the immunocytochemical alpha MSH-like activity in the MCH neurones may not be authentic alpha MSH.

Animals↗
PubMed1987

Hypothalamo-pituitary-interrenal responses to opioid substances in the trout. I. Effects of morphine on the release in vitro of corticotrophin-releasing activity from the hypothalamus and corticotrophin from the pituitary gland.

The effects of morphine and naloxone on the secretion in vitro of corticotrophin (ACTH) and and corticotrophin-releasing factor (CRF) by the pars distalis and hypothalamus, respectively, have been studied in the trout. The spontaneous in vitro secretion of corticotrophin by the pars distalis is depressed significantly by the addition of high concentrations of morphine (10(-6)-10(-7) mol/litre) to the incubation medium. The effect is naloxone reversible. Morphine does not influence the response of the pituitary tissue to exogenous CRF41, suggesting that the inhibitory influence of the opiate is exerted primarily on the CRF nerve terminals within the pars distalis and not on the corticotrophs. At considerably lower concentrations (10(-10)-10(-8) mol/litre) morphine stimulates the release of CRF from the isolated trout hypothalamus in vitro. Its effects are dose-dependent and antagonized by naloxone. The results suggest that two anatomically and pharmacologically distinct populations of opioid receptors mediate opposing actions of morphine on the hypothalamo-pituitary-corticotrophic system in the trout.

Adrenocorticotropic Hormone↗
PubMed1987

Hypothalamo-pituitary-interrenal responses to opioid substances in the trout. II. Effects of morphine and D-Ala2, Met5-enkephalinamide on plasma cortisol titres in vivo.

The influence of morphine, D-Ala2, Met5-enkephalinamide (DALA), and naloxone on plasma cortisol titres has been studied in vivo in fingerling and adult trout. The responses were complex and variable. A single ip injection of morphine or DALA into fingerlings usually resulted in a rise in plasma cortisol after 0.5 hr followed by a fall below control values within 2 hr. In similar experiments with adult trout, only an inhibitory effect was observed. Naloxone reduced the rise in plasma cortisol following saline injection, but only when the hypothalamo-pituitary-interrenal response was intense. The antagonist also blocked the morphine-induced rise in cortisol secretion. Prolonged morphine treatment diminished both the postinjection and stress-induced secretion of cortisol in adult fish. Morphine had no effect on the spontaneous or ACTH-induced secretion of cortisol by interrenal tissue incubated in vitro. The results support the concept of inhibitory and stimulatory sites of action by opiates and opioid substances on the hypothalamo-pituitary-interrenal axis. These findings are discussed with reference to the action of morphine on hypothalamic and pituitary tissue of the trout in vitro and with the opioid control of hypothalamo-pituitary-adrenal function in mammals.

Adrenocorticotropic Hormone↗
PubMed1986

Effects of chronic administration of melanin-concentrating hormone on corticotrophin, melanotrophin, and pigmentation in the trout.

This paper reports the effects of salmonid melanin-concentrating hormone (MCH), administered via an Alzet minipump, on pigmentation and secretion of pituitary melanotrophin (MSH) and corticotrophin (ACTH) by black-adapted, adult rainbow trout. The drug induced melanin concentration in the skin melanophores and prevented melanogenesis. Both the cytological appearance of the pituitary pars intermedia and determinations of plasma alpha-MSH suggest that MCH prevented the increase in secretory activity of the melanotrophic cells seen normally in black-adapted trout. Resting plasma cortisol titres were similar in all groups of fish but anterior pituitary glands taken from stressed, MCH-treated fish released less ACTH in vitro than those from corresponding saline-treated fish.

Adrenocorticotropic Hormone↗
PubMed1986

Annulate lamellae and single-pore complexes in human spermatogonia.

Electron microscopic examination of non-neoplastic human testes revealed cytoplasmic annulate lamellae (AL) in all cell types within the seminiferous epithelium. Short lamellar profiles with low numbers of pores were found in spermatogonia and spermatocytes, while larger stacks of AL were seen in spermatids and Sertoli cells. Stacks of lamellae were closely associated with redundant nuclear envelope during late spermiogenesis. Residual bodies shed by the developing spermatozoa contained large number of lamellar-pore complexes. One cryptorchid testis was also examined. In this case the seminiferous epithelium consisted only of Sertoli cells with rare spermatogonia. AL were found in both cell types, with a similar morphology to those of the non-neoplastic testes. This study demonstrates that AL are expressed in all stages of spermatogenesis.

Adult↗
PubMed1985

Salmonid melanin-concentrating hormone inhibits corticotrophin release.

Melanin-concentrating hormone (MCH) is a neural peptide associated with colour change in fishes. We show here that it also inhibits corticotrophin (ACTH) secretion. Synthetic salmonid MCH at a concentration of 100pmol/l reduced the in-vitro release of ACTH by pars distales (pDs) taken from stressed trout. At lower concentrations (10pmol/l) the peptide inhibited CRF-41-induced secretion of ACTH by pDs removed from unstressed trout, while at higher concentrations (10nmol/l) it reduced the corticotrophic response of rat pituitary tissue to CRF-41.

Adrenocorticotropic Hormone↗
PubMed1983

Changes in the water/lipid relationship during the spawning-run of lampreys.

The relationships between the percentage water and lipid contents of the liver, muscle and gonad have been investigated in adult lampreys. While the relationship between water and lipid in any organ or tissue could generally be expressed by regression lines with a common slope, the intercepts showed a marked tendency to differ sequentially in groups examined throughout the spawning-run period. At any one time, marked differences were found between the slopes relating water and lipid in different tissues or organs.

Animals↗
PubMed1983

Allergy to laboratory animals: a retrospective and a prospective study.

Twenty four volunteers who had been allergic to laboratory animals for some years were examined by means of a questionnaire paying particular attention to symptoms associated with rats and by serological and skin tests with extracts of rat urine (retrospective study). Nasal and eye symptoms were reported by 21 and 16 individuals respectively: 13 had asthma. Positive skin tests and high levels of specific IgE antibody to rat urine extract were found in 17 of the more severely affected individuals and this group included 12 of those with asthma. Latent periods of work with animals before symptoms appeared varied from 0.5 to 12 years. Also 148 individuals were studied during their first year of work with animals (prospective study). Symptoms developing during the year were reported by 15%, asthma by 2%. IgE antibody levels to rat urine were raised in 40% of affected and 6% of the unaffected individuals but there was no significant correlation between symptoms and either antibody levels or positive skin tests. Allergic symptoms developing during the first year of postemployment were, on the whole, much milder than those seen in the retrospective study. A tentative conclusion is that most individuals who become allergic to laboratory animals develop the condition in a mild form during their first year of employment but it appears probable that atopic individuals, although having an equal chance of developing allergy as compared with non-atopic individuals, may eventually progress to a more severe form of the disease.

Allergens↗
PubMed1976

Oxygen dissociation curves of the blood of larval and adult lampreys (Lampetra fluviatilis).

1. An electrolytic method was used to plot the oxygen dissociation curves of whole blood from both the larva and adult of the lamprey Lampetra fluviatilis at a temperature of 10 degrees C and over a pH range of 6-5-8-1. 2. Larval blood has a far higher affinity for oxygen than that of adults, the respective calculated P50's at a pH of 7-75 being 1-9 and 10-7 mmHg. 3. The high affinity of larval blood is of use to a relatively sedentary animal living in burrows, and the increased oxygen delivery pressure brought about by the shift of the curve to the right in the adult is of advantage to an animal exhibiting greater activity. 4. The n value obtained from the Hill plots increased with increasing saturation and were lower in larvae than adults at the same level of blood saturation. 5. The Bohr effect in larvae at 10 degrees C over the pH range 6-5-8-1 was --0-25, a value which did not differ significantly from the -0-22 found in adults.

Aging↗
PubMedDate not supplied

Correlative changes in metabolism and DNA damage in turbot (Scophthalmus maximus) exposed to benzo[a]pyrene.

Juvenile turbot (Scophthalmus maximus) were injected intraperitoneally with either corn oil or 5 mg/kg benzo[a]pyrene (BaP) dissolved in corn oil and sampled I and 3 days after injection. After 1 day, no elevation of 7-ethoxyresorufin O-deethylase (EROD) activity was observed, however bile metabolites (BaP-7,8 dihydrodiol representing 70% of the total metabolites) and a single hepatic DNA adduct spot (0.47 adducts/10(8) nucleotides) identified by 32P-postlabelling were formed. No BaP metabolites or DNA adducts were observed in either control or carrier control fish. Fish sampled after 3 days reported 5-fold higher (P < 0.05) levels of EROD activity, a shift in the bile metabolite profile towards BaP phenol formation (1OH and 30H BaP comprising up to 60% of total metabolites detected) and the formation of two adduct spots (0.86 and 0.71 adducts/10(8) nucleotides). These results show that BaP can be metabolised and form hydrophobic DNA adducts in turbot without EROD elevation. Following EROD elevation, a shift in the profile of both BaP metabolites and BaP metabolite-DNA interactions occurs indicative of other oxidative processes.

Animals↗
PubMedDate not supplied

Sarcomatoid renal cell carcinoma metastatic to the heart: report of a case.

An unusual case of metastatic sarcomatoid renal cell carcinoma is presented. Fifteen months after nephrectomy for a typical clear cell carcinoma, a 63-year-old man presented with bilateral pleural effusions, cardiomegaly, and tamponade. A pericardial biopsy showed an anaplastic spindle cell tumor that was strongly keratin positive and showed desmosomes ultrastructurally. The patient died shortly thereafter, and the autopsy revealed massive tumor infiltration of the heart, pulmonary and adrenal metastases, and tumor nodules at the incision site of his nephrectomy. The differential diagnosis of sarcomatoid renal cell carcinoma is discussed.

Carcinoma, Renal Cell↗
PubMedDate not supplied

Aorticopulmonary paraganglioma (aortic body tumor): report of a case.

A case of aorticopulmonary paraganglioma in a 57-year-old man is described. The tumor comprised nests of uniform cells in a fibrovascular stroma. Electron microscopy revealed abundant neurosecretory granules, and S-100 protein staining demonstrated scattered sustentacular cells at the periphery of typical zellballen. The findings in this case correlated with those of studies on the prognosis for extraadrenal paragangliomas.

Aorta↗
PubMedDate not supplied

Malignant myoepithelioma of the larynx with massive metastatic spread to the liver: an ultrastructural and immunocytochemical study.

A malignant myoepithelioma arising in the submucosal glands of the larynx of a 71-year-old man is reported. The patient presented with a neck mass and massive metastatic involvement of the liver. Light microscopy of a liver biopsy specimen and fine-needle aspiration sample of the neck mass revealed a poorly differentiated carcinoma. Electron microscopic study of a second liver biopsy specimen demonstrated unequivocal features of myoepithelial differentiation; this was further confirmed by the strong cytokeratin and S-100 protein positivity and carcinoembryonic antigen negativity of the tumor cells. Myoepitheliomas are rare tumors, and most reported cases have been benign or of low-grade malignancy. The present case is unique because of its mode of presentation and fulminant course. It also underscores the usefulness of electron microscopy as a diagnostic modality in the work-up of metastatic lesions.

Aged↗
PubMedDate not supplied

Carcinoid tumor of the kidney with morphologic and immunohistochemical profile of a hindgut endocrine tumor: report of a case.

A 54-year-old man underwent a radical nephrectomy for a presumed renal cell carcinoma. The tumor was large, showed areas of cystic degeneration and calcification, and had completely obliterated the normal renal parenchyma. The light microscopic appearance was atypical for renal cell carcinoma, and when electron microscopy revealed innumerable neurosecretory granules a diagnosis of carcinoid tumor was made. The tumor cells were argentaffin- and argyrophil-negative but were chromogranin-, neuron-specific enolase-, and leu-7-positive. When tested with a battery of antibodies against specific polypeptide hormones, the tumor exhibited diffuse pancreatic polypeptide and focal somatostatin immunoreactivity. Our case represents only the 16th case of carcinoid tumor of the kidney to be reported and the first with demonstrated pancreatic polypeptide immunoreactivity. The predominantly trabecular histology, nonreactivity with silver stains, and immunohistochemical profile of this case are common characteristics of hindgut carcinoids, suggesting that, like rectal carcinoids, renal carcinoids are tumors of hindgut endocrine cells.

Antigens, Differentiation↗