Biomedical subjects

B C Williams

Publications and source records attributed to B C Williams.

149 records · Page 9Linked to original sources

PubMedDate not supplied

Report of illnesses caused by aldicarb-contaminated cucumbers.

During May and June of 1985 the Health Protection Branch and several other agencies were involved in the investigation of over 300 reports of illness reported in the Vancouver area of British Columbia, Canada. Symptoms reported included nausea, vomiting, dizziness, muscle fasciculation and blurred vision. A review of the onset of symptoms and food consumed suggested that at least 140 people had become ill from eating cucumbers adulterated with a carbamate pesticide. The presence of residues of aldicarb in cucumbers from one particular producer was confirmed by laboratory analysis.

Adolescent↗

PubMedDate not supplied

Use of administrative records to describe longitudinal patterns of health services use among veterans.

Administrative records of the Department of Veterans Affairs (DVA) and the National Death Index were linked to create a four-year longitudinal database that describes the clinical status, hospital and nursing home use, and mortality for a nationwide cohort of persons admitted to DVA nursing homes (n = 23,039). Using Social Security Numbers as identifiers, the records of only 6% of these persons had logically inconsistent or implausible patterns. Nineteen percent of the remaining records had correctable logical errors. Information on the creation, consistency, and potential uses of this database may prove useful to health services researchers interested in describing longitudinal patterns of health care use across multiple settings within and outside the DVA.

Bias↗

PubMedDate not supplied

Acetylcholine induces oscillations in intracellular calcium in isolated bovine adrenal zona fasciculata/reticularis cells.

The effects of acetylcholine (ACh) on intracellular free calcium were studied in primary cultures of purified bovine adrenal zona fasciculata/reticularis (ZFR) cells. In fura-2 loaded single cells, concentrations of ACh which stimulated cortisol secretion and phosphoinositol production were found to promote an increase in free cytosolic calcium ([Ca2+]i). This response was heterogeneous, showing either (i) an initial increase in [Ca2+]i followed by a fall to a level above that in unstimulated cells, or (ii) an initial increase followed by oscillations about the original resting level or a higher resting level. The frequencies of [Ca2+]i oscillations to ACh showed a dose-dependent trend. The sustained [Ca2+]i oscillations were abolished by the muscarinic antagonist atropine, or by removal of extracellular Ca2+. These data demonstrate for the first time in adrenocortical cells that: (i) ACh can induce [Ca2+]i oscillations in single ZFR cells; (ii) these oscillations occur in a dose-dependent manner; (iii) the sustained oscillatory phase is dependent on influx of extracellular Ca2+. Thus, like cells of the zona glomerulosa, bovine ZFR cells are also capable of sustained dose-dependent oscillatory responses to agonists which activate phosphoinositidase C.

Acetylcholine↗

PubMedDate not supplied

StAR protein is expressed in both medulla and cortex of the bovine and rat adrenal gland.

We have employed polyclonal antibodies to a peptide sequence of bovine steroidogenic acute regulatory (StAR) protein and human placental 3beta-hydroxysteroid dehydrogenase (3beta-HSD) to determine the localisation and distribution of these proteins in rat and bovine adrenal glands. Immunohistochemical staining demonstrated the presence of StAR protein in the zona glomerulosa (ZG), zona fasciculata (ZF), zona reticularis (ZR) and in the medulla of both species. For 3beta-HSD, immunostaining was observed in the ZG, ZF and ZR of the rat adrenal and was absent in the medulla. Immunoblotting experiments showed intense bands for StAR protein (30 kDa, 37 kDa) in the mitochondria of bovine ZG, ZF and medulla and a less intense band (30 kDa) in the microsomes. In rat ZG and ZF/R mitochondria only the 30 kDa protein was present. For 3beta-HSD, an intense band (42 kDa) was found in microsomes and mitochondria of rat and bovine ZG and ZFR. A very faint signal for 3beta-HSD was seen in adrenal medulla. In conclusion, StAR (or a closely related) protein is present throughout the adrenal gland in rat and bovine species in contrast to 3beta-HSD which is confined to the steroidogenic zones. The possible function of StAR protein in the adrenal medulla merits investigation.

3-Hydroxysteroid Dehydrogenases↗

PubMedDate not supplied

Dopaminergic stimulation of cortisol secretion from bovine zfr cells occurs through nonspecific stimulation of adrenergic beta-receptors.

Previous reports have suggested a possible dopaminergic inhibition of the actions of AII on aldosterone secretion via adenylate-cyclase inhibitory 'D2' receptors. Others suggest a possible stimulation of aldosterone secretion via a stimulatory 'D1' receptor/cAMP pathway. We have examined the actions of dopamine on basal and AII-stimulated cortisol secretion by cultured bovine zfr cells. Dopamine alone caused a dose-dependent increase in cortisol secretion at doses >10(-5) M, and also enhanced steroidogenic output in response to submaximal (10(-10) M) but not maximal (10(-8) M) stimulatory doses of AII. The stimulatory action of dopamine alone on cortisol secretion was not, however, reproduced by the 'D1' agonist fenoldopam, and was fully blocked by propranolol. Dopamine had neither a stimulatory effect on basal phosphoinositol production nor an inhibitory effect on AII-stimulated phosphoinositol production. Our findings are therefore inconsistent with the activation of a 'D1' or 'D2' class receptor, and suggest the stimulation of cortisol secretion occurred nonspecifically through a beta-adrenergic receptor.

Angiotensin II↗