Adhesion of nonmetastatic and highly metastatic breast cancer cells to endothelial cells exposed to shear stress

The mechanical stimulus of shear stress has to date been neglected when studying the adhesion of cancer cells to the endothelium. Confluent monolayers of endothelial cells were subjected to either 4 or 15 hours of arterial shear stress. Adhesion of nonmetastatic (MCF-7) and highly metastatic (MDA-MB-435) human breast cancer cells was then quantified using a detachment assay carried out inside the parallel plate flow chamber. Four hours of shear stress exposure had no effect on adhesion. However, 15 hours of shear stress exposure led to marked changes in the ability of the endothelial monolayer to bind human breast cancer cells. An increase in adhesive strength was observed for nonmetastatic MCF-7 cells, while a decrease in adhesive strength was observed for highly metastatic MDA-MB-435 cells. Hence, endothelial shear stress stimulation does influence the adhesion of cancer cells to the endothelium and can have different effects on the adhesion of cancer cells with different metastatic potentials. Furthermore, adhesion of nonmetastatic and highly metastatic human breast cancer cells may be controlled by two different endothelial cell adhesion molecules that are differentially regulated by shear stress. Immunohistochemistry confirmed that shear stress did in fact differentially regulate endothelial cell adhesion molecule expression.

Children-in-law in caregiving families

Data were collected from 252 coresident caregiving daughters and daughters-in-law and their husbands. We hypothesized that biological children would give more care than children-in-law and that children-in-law would have very different caregiving experiences and resultant appraisals than biological children. Contrary to our hypotheses, we found that the experiences are very similar for biological children and children-in-law in caregiving families. We suggested that the important factor is not the relationship to the elder that has the impact--it is the quality of the relationship with the elder that is consistently significant.

FastTag Nucleic Acid Labeling System: a versatile method for incorporating haptens, fluorochromes and affinity ligands into DNA, RNA and oligonucleotides

The FastTag Nucleic Acid Labeling System couples haptens, fluorochromes or affinity ligands to any nucleic acid by attaching a universal, photo-or heat-activatable moiety to which any sulfhydryl-reactive compound can be linked. To demonstrate the versatility of the FastTag system, we have labeled DNA, RNA and oligonucleotide probes with a variety of maleimide-coupled moieties and have used these probes in several applications. In Southern hybridization analyses, RNA probes labeled using FastTag FL (fluorescein) detected 0.04 pg of target DNA. Human satellite DNA clones labeled using FastTag FL or FastTag Biotin detected the corresponding sequences in human chromosome spreads and interphase nuclei by fluorescence in situ hybridization. An antisense oligonucleotide probe cocktail complementary to human proinsulin transcripts labeled using FastTag DNP (dinitrophenyl) detected, in situ, the appropriate transcripts in pancreatic tissue sections. Oligonucleotide primers labeled with FastTag FL were used to PCR-amplify a genomic DNA fragment, which was then detected immunologically. Finally, we discuss how DNA labeled with FastTag Fucose can be bound to a fucose-binding affinity matrix and eluted under mild conditions.

Ectasia of the vertebral artery as a cause of isolated pyramidal tract signs: case report and a review of the literature

A rare presentation of vertebral artery ectasia is reported with magnetic resonance imaging and angiographic correlation. The unusually low level of the abnormality had previously resulted in an incorrect diagnosis of primary pyramidal degeneration. One similar case has been reported in the world literature.

Middle-Aged Son's Reactions to Father's Death

This article concerns the domain of men's grief and bereavement. It reports on findings from a research project in which we qualitatively interviewed, in a 2 × 2 design, middle-aged sons and daughters concerning the meaning of the death of their widowed elderly mother or father. We interviewed forty-three sons who recently experienced the death of their widowed father. We suggest that the normative model of bereavement is feminized and does not adequately account for men's experiences. In the domain of bereavement, men are often “the other.” We outline and discuss four themes in men's bereavement: control, action, cognition, and privacy.

Impact of elderly mother's death on middle age daughters

Daughters' responses to an elderly mother's death are found to be multidimensional. In the first six months of bereavement many daughters experience themes of both holding on and letting go. Measured were depression, grief, somatic reactions, as well as impact on the sense of self, degree of acceptance of the death, and ways in which the tie with the mother endures. Though many of these reactions are intercorrelated, they are differentially associated with characteristics of the daughter, mother, and the quality of their relationship. Relatively sudden deaths were associated with more intense grief, less acceptance, and more thoughts of reunion than deaths that occurred in a nursing home.

Time use of caregivers of impaired elders before and after institutionalization

Time use was examined by means of time budgets obtained from 165 caregivers of older persons recruited from nursing home waiting lists and state nursing home assessment programs. "Yesterday interviews" were done at baseline (T1) and, again, an average of 5 months later when the elder had either entered a nursing home (n = 77) or was still awaiting entry (n = 88). Caregivers who provided more help (particularly instrumental assistance) to their elder were more likely to see that person placed in a nursing home at follow-up. More caregiving time was reported by those living with the elderly person and by nonworking and lower income caregivers; the elders being cared for by these groups were also more impaired. Less caregiving time (a total gain of 1 hour 47 minutes) was reported by caregivers following admission of the older person to the nursing home. The gained time was allocated to a significant degree to family interaction, recreation, and time outside the home.

The role of pain in the last year of life of older persons

A random sample of 200 decreased older community residents was studied with a focus on the role of pain in the last year of life. Interviews with a surviving close person elicited retrospective reports. Pain increased over the final year; one month before death 66% felt pain frequently or all of the time, substantially higher than a matched comparison group of living persons (24%). For both groups across the year, pain was associated with most measures of behavioral competence, perceived quality of life, and psychological well-being. Hierarchical multiple regressions indicated that background and health variables explained 28% to 32% of the variance of pain over the year. Controlling for background variables and health, pain contributed significantly to lowered happiness and to depression, but had no independent impact on hope and interest in the world. After controlling for physical health, the older old were judged to have less pain than the younger old.

The excretion of theobromine in Thoroughbred racehorses after feeding compounded cubes containing cocoa husk--establishment of a threshold value in horse urine

Thoroughbred geldings were fed racehorse cubes containing a predetermined concentration of theobromine in the form of cocoa husk. They were offered 7 kg of cubes per day, divided between morning and evening feed, and food consumption was monitored. Urinary concentrations of theobromine were determined following the consumption of cubes containing 11.5, 6.6, 2.0 and 1.2 mg per kg of theobromine, to verify whether or not such concentrations would produce positive urine tests. Pre-dose urine samples were collected to verify the absence of theobromine before each experiment. It became apparent from the results of the first three administrations that the limit of detection of theobromine, using such procedures, would be reached at a feed level of about 1 mg per kg theobromine. Therefore the final administration, using cubes containing 1.2 mg per kg theobromine, was singled out for additional analytical work and quantitative procedures were developed to measure urinary concentrations of theobromine. It was anticipated that the results would form a basis for discussions relating to the establishment of a threshold value for theobromine in horse urine. The Stewards of the Jockey Club subsequently gave notice that they had established a threshold level for theobromine in urine of 2 micrograms/ml.

Reactivity of monoclonal antibody 17.13. with human squamous cell carcinoma and its application to tumor diagnosis

Monoclonal antibody 17.13., derived from a fusion of splenocytes of a BALB/c mouse immunized with a surgically resected poorly differentiated human laryngeal recurrent squamous cell carcinoma (SCC) with mouse Sp2/0 cells, is an IgM-K which recognizes a cytoplasmic component of basal cells. Tissue sections of malignant and normal squamous epithelium, tumors of nonsquamous origin, and normal and malignant cytological specimens were tested with an immunoperoxidase assay. Seventy-nine of 81 (98%) SCC of the head and neck, 26 of 26 (100%) SCC of the cervical and female gynecological tract, 29 of 30 (97%) SCC of the lung, 19 of 19 (100%) SCC of the oral cavity, and 17 of 17 (100%) SCC-involved neck lymph nodes reacted strongly. Various carcinomas from breast, colon, ovary, and others were unreactive. In normal squamous epithelial tissues, monoclonal antibody 17.13. reacts only with basal cells but not the cells above the basal layers. Normal tissues from heart, liver, spleen, kidney, bladder, colon, ovary, stomach, pancreas, breast, lung, prostate, thyroid, and lymph nodes were unreactive with the exception of myoepithelial cells. Monoclonal antibody 17.13. may be useful in the diagnosis and management of SCC.

The bioavailability of phenylbutazone in the horse

[phenyl-14C]-Phenylbutazone was administered to 2 horses p.o. and i.v. on separate occasions. Plasma levels and urinary and faecal elimination of 14C were monitored for up to 7 days after dosing. Phenylbutazone was rapidly and extensively absorbed after oral administration, and its bioavailability was 91% assessed by comparison of plasma AUCs of unchanged drug after p.o. and i.v. administration. The plasma elimination half-life of phenylbutazone was 9.7 h and this was independent of the route of administration. The pattern of elimination of phenylbutazone was independent of the route of administration, with 55% of the dose being found in the urine in 3 days and a further 39% in the faeces in 7 days. These data, which are the first reports of the absolute bioavailability and excretion pathways of phenylbutazone in the horse, are discussed in terms of their significance for the gastrointestinal toxicity of this drug.

The lack of effect of inoculation with equine influenza vaccine on theophylline pharmacokinetics in the horse

Several studies conducted during the past few years have shown that the pharmacokinetics of a variety of drugs may be altered following viral infection or vaccination. The elimination of drugs which are extensively metabolized, such as theophylline, may be prolonged, especially following exposure to RNA viruses such as Type A influenza or similar orthomyxoviruses. The purpose of this study was to determine whether vaccination of horses with equine influenza virus affected pharmacokinetic parameters describing the distribution and elimination of intravenously administered theophylline. Three thoroughbred horses and three ponies were vaccinated with a trivalent vaccine containing inactivated strains of A/Equi 1 (Prague), A/Equi 2 (Miami) and A/Equi 2 (Kentucky 81). Antibody titre, serum interferon concentrations, and the pharmacokinetic parameters t1/2 beta, Vc, Vd(ss), Vd(area) and ClB were measured at various intervals after vaccination. Antibody titre increased substantially in only two animals, while plasma interferon was detectable in low concentrations in four subjects. There was no significant change in any parameter describing the pharmacokinetics of theophylline when measured 2, 6, or 12 days after vaccination. It is suggested that the failure of vaccination to substantially increase plasma interferon concentrations, and thereby alter theophylline elimination, was related to the use of an inactivated viral vaccine, the only type available for vaccination of horses against infection with equine influenza. Regular use of such vaccines, as is required by most Racing Authorities, is therefore unlikely to affect drug withdrawal times.

Development of a gas chromatographic-mass spectrometric method using multiple analytes for the confirmatory analysis of anabolic steroid residues in horse urine. II. Detection of administration of 19-nortestosterone phenylpropionate to equine male castrates and fillies

Esters of 19-nortestosterone form an important group of anabolic preparations used in veterinary practice. Based upon results from detailed metabolic studies for 19-nortestosterone in the horse, a method to confirm the administration of anabolic preparations of this steroid to castrated male horses and fillies is described; the method is based upon the use of multiple analytes. Following administration of the anabolic preparations, solid-phase extraction of urinary conjugates and the separation of the conjugate groups prior to hydrolysis allow for the determination of specific metabolites conjugated with either glucuronic acid or sulphate. Following hydrolysis of the conjugates, purification of the free neutral steroids on thin-layer chromatography, derivatisation and gas chromatographic-mass spectrometric analysis, the presence of the major metabolites, estrane-3,17 alpha-diol in the glucuronic acid fraction and 19-nortestosterone and two isomers of estrane-3,17-diol in the sulphate fraction, could be confirmed for 17-18 days after administration of Nandrolin (19-nortestosterone phenylpropionate).

The biotransformation and urinary excretion of dexamethasone in equine male castrates

The pro-drugs of dexamethasone, a potent glucocorticoid, are frequently used as anti-inflammatory steroids in equine veterinary practice. In the present study the biotransformation and urinary excretion of tritium labelled dexamethasone were investigated in cross-bred castrated male horses after therapeutic doses. Between 40-50% of the administered radioactivity was excreted in the urine within 24 h; a further 10% being excreted over the next 3 days. The urinary radioactivity was largely excreted in the unconjugated steroid fraction. In the first 24 h urine sample, 26-36% of the total dose was recovered in the unconjugated fraction, 8-13% in the conjugated fraction and about 5% was unextractable from the urine. The metabolites identified by microchemical transformations and thin-layer chromatography were unchanged dexamethasone, 17-oxodexamethasone, 11-dehydrodexamethasone, 20-dihydrodexamethasone, 6-hydroxydexamethasone and 6-hydroxy-17-oxodexamethasone together accounting for approx 60% of the urinary activity. About 25% of the urinary radioactivity associated with polar metabolites still remains unidentified.

Predictors of falls among institutionalized women with Alzheimer's disease

Falls among elderly residents are a major concern of facilities caring for the aged. A group of institutionalized women with senile dementia of the Alzheimer type (N = 60; mean age 83) were studied longitudinally and evaluated annually on 21 variables of physical, social, emotional, self-care, and cognitive functioning. A substudy of falls they experienced used data from two such annual evaluations. Clinical ratings by the interdisciplinary team estimated 1) the women's changes in function during the preceding year and 2) the current levels of the women's functioning. Separate regressions for each of the two years returned identical significant patterns indicating that ratings of physical vigor were significantly related to number of falls. Those women who had been among the most vigorous in the group but who had shown significant declines in the preceding year were the most vulnerable to falls; women who had been rated as the least vigorous but whose levels of vigor had been stable during the year tended to have fewer falls. Falling therefore appears to be related to the process of decline in vigor among those in the group whose levels of vigor were higher initially. There were corresponding significant declines in emotional and cognitive scales.

The identification of C-18 neutral steroids in normal stallion urine

As part of a continuing research program associated with the detection of anabolic steroid residues in horse urine, normal samples from entire male horses have now been investigated. Isomers of three C-18 neutral steroids; 4-estren-17-ol-3-one (1), estrane-3,17-diol (2) and an unsaturated estranediol having a possible structure (3), have been identified in urine samples from two male horses aged 8 and 14 years. Of these three steroids, compound (2) was not detected in the urine of a 2.5 yr old entire male nor in the majority of post-race urine samples from entire male horses average age 3.8 yrs (n = 34). Ten of these samples showed tentative indications of this compound. Although the isolation of isomers of estrane-3,17-diol from human non-pregnancy urine has been reported previously, analysis of non-pregnancy urine samples in the present study did not reveal the presence of these compounds.

The fine structure of the caudal periaqueductal gray of the cat: morphology and synaptic organization of normal and immunoreactive enkephalin-labeled profiles

Although the midbrain periaqueductal gray (PAG) is thought to have a major role in an endorphin-mediated analgesia system, little is known about its neuroanatomical organization. To determine the microcircuitry within the PAG through which exogenous and endogenous opiates may act, we analyzed the synaptic organization of normal and immunoreactive enkephalin (ENK)-labeled profiles in the caudal PAG, a region of particular interest because of its effectiveness in generating analgesia. Examination of the normal fine structure of this region demonstrated that there is no characteristic synaptic morphology that distinguishes individual regions of the caudal PAG (ventromedial, ventrolateral and dorsolateral) from one another. In all 3 regions of the caudal PAG, axodendritic synapses are the predominant form of synaptic interaction making up 93-97% of all synapses counted. Axosomatic synapses are much less common, as are presumed axoaxonic and dendrodendritic synapses. In the caudal ventral PAG, the largest population of ENK-labeled axonal boutons are found presynaptic to unlabeled, centrally placed dendrites. Much less frequently, immunoreactive ENK-containing boutons are found presynaptic to neuronal perikarya or vesicle-containing profiles. Thus, these results suggest that the dendrites of neurons intrinsic to the PAG are the most probable site of opiate action in the caudal ventral PAG.

The peptidergic organization of the cat periaqueductal gray. II. The distribution of immunoreactive substance P and vasoactive intestinal polypeptide

Despite the important contribution of the midbrain periaqueductal gray (PAG) to endogenous pain suppression systems, little is known about the neuroanatomical basis of its functional organization. In a previous study of the distribution of the endogenous opiate leucine-enkephalin (ENK) in the PAG (Moss, M. S., E. J. Glazer, and A. I. Basbaum (1983) J. Neurosci. 3: 603-616), we found that immunoreactive ENK-containing neurons and terminals are clustered in discrete populations. In this study we have extended our analysis of the neurochemical organization of the PAG by using immunocytochemistry to map the distribution of two non-opiate peptides that produce potent analgesia when administered at central gray levels: substance P (Sub P) and vasoactive intestinal polypeptide (VIP). Immunoreactive Sub P neurons and terminal fields are clustered in discrete populations throughout the PAG. The distribution pattern of these populations changes at different rostral-caudal levels of the PAG. For example, there is a ventral-to-dorsal shift in the location of Sub P-like immunoreactivity from the caudal to the rostral PAG. Few immunoreactive Sub P neurons are found in the nucleus raphe dorsalis although moderately dense terminal field staining is present. The staining pattern of immunoreactive VIP is totally different from that of Sub P. Regardless of the rostral-caudal level examined, VIP-containing neurons are found tightly clustered in the subependymal neuropil of the ventromedial PAG. Only a few immunoreactive VIP-containing neurons are found in the ventral PAG or nucleus raphe dorsalis. The striking differences between the distribution of Sub P- and VIP-like immunoreactivity in the PAG indicates that the neural circuitry underlying pain suppression by Sub P and VIP may also differ.

The metabolism of fenclofenac in the horse

14C-Fenclofenac (2-(2'-4'-dichlorophenoxy)-phenylacetic acid) was administered orally to horses, and urinary metabolites investigated by chromatography. Fenclofenac was rapidly absorbed and eliminated, with a plasma half-life (t1/2) of 2.3 h, with 83.2 and 85.8% of the dose being recovered in the urine in 0-24 h. The major urinary metabolite was the ester glucuronide (58.8, 70.0% dose), and evidence is presented that this metabolite undergoes a structural rearrangement to give beta-glucuronidase-resistant isomers. The other 14C-labelled components in horse urine were unchanged fenclofenac (13.1, 11.5% dose), and two minor metabolites, one of which was identified as a monohydroxy fenclofenac. This study is the first to show an ester glucuronide to be the major metabolite of a non-steroidal anti-inflammatory drug in the horse.

The peptidergic organization of the cat periaqueductal gray. I. The distribution of immunoreactive enkephalin-containing neurons and terminals

Despite the significant contribution of the periaqueductal gray (PAG) to an endogenous pain suppression system, little is known about its neurochemical organization. Previous pharmacological and physiological studies have indicated regional variations in the effectiveness with which the midbrain PAG can generate potent analgesia in response to either opiate microinjection or electrical stimulation. There is, however, no anatomical correlate of this regional variation. As a first step toward elucidating the neural circuitry underlying the PAG's contribution to endogenous pain suppression systems, we have mapped the distribution of leucine enkephalin (ENK)-like immunoreactivity in the cat PAG. Throughout the rostral-caudal extent of the PAG, ENK-containing neurons are clustered in discrete populations. ENK terminal field staining is somewhat more diffuse; however, there are several regions where terminal staining is consistently more intense. The distribution of ENK perikarya and terminals undergoes a ventral to dorsal shift from caudal to rostral PAG. Conceivably, the clustered distribution of ENK cells and terminals contributes to the differential effectiveness of various PAG regions in generating analgesia. The ventral-dorsal shift of ENK immunoreactivity may (1) correspond to a somatotopic organization within the PAG or (2) mirror the topographic relationship of the PAG's interactions with other components of the endogenous analgesia system. In addition, the changing pattern of ENK immunoreactivity may also reflect the involvement of the PAG and of endogenous opiates in systems other than those of pain control.

3-Hydroxy- and 3-keto-3-phenylpropionic acids: novel metabolites of benzoic acid in horse urine

The metabolism of benzoic acid has been examined in the horse, using 14C- and deuterium-labelled compounds. Chromatographic analysis of the urine showed the presence of hippuric acid, benzoyl glucuronide and benzoic acid and a discrete band which accounted for 2% of the dose administered. This material was isolated by solvent extraction and HPLC and, following treatment with diazomethane, examined by GC/MS. The major component of this fraction was 3-hydroxy-3-phenylpropionic acid methyl ester, which was accompanied by very much smaller amounts of cinnamic acid methyl ester and acetophenone. The two latter minor components have been shown to be artefacts produced during workup and analysis. Cinnamic acid methyl ester arises by the thermal decomposition of 3-hydroxy-3-phenylpropionic acid methyl ester on the GC column. It is proposed that acetophenone has formed, during workup, by decarboxylation of 3-keto-3-phenylpropionic acid. It is suggested that 3-hydroxy and 3-keto-3-phenylpropionic acids, which are also endogenous in horse urine, have arisen by an addition of a 2 carbon fragment to benzoyl CoA, in a sequence analogous to the reactions of fatty acid biosynthesis. Some implications of the metabolic interrelationships between xenobiotic acids and fatty acids are discussed.

Plasma concentrations and urinary excretion of nandrolone and/or its metabolites after intramuscular injection of nandrolone phenylpropionate to horses

A radioimmunological method was used as a screening procedure to determine the period of detection or "clearance time", for the horse, of therapeutic doses of the synthetic anabolic steroid nandrolone phenylpropionate. Seven horses, either at rest or being exercised, were given a course of weekly intramuscular injections of the steroid. On the separate occasion, some of the horses were given a single intramuscular injection of the same compound. The weekly injections maintained a high plasma concentration of nandrolone and/or metabolites. The mean (+/- sd) period of detection in plasma of these compounds was 23 (+/- 2) days (range 21 to 25) in resting horses and 20 (+/- 6) days (range 14 to 27) in exercised animals. The mean period of detection in urine was 25 (+/- 7) days (range 16 to 32) and 25 (+/- 12) days (range 9 to 38) for resting and exercised horses, respectively. After a single intramuscular injection to resting horses, the mean periods of detection were 12(+/- 2) days (range 9 to 15) and 13 (+/- 2) days (range 11 to 16) in plasma and urine, respectively. In all experiments there was considerable individual variation in the time taken for the plasma and urine concentrations to return to pre-dose values. This variation was particularly marked in the urine of exercised horses given a course of injections. With horses in training, this period may be over 5 weeks, a period approaching the minimum of 42 days advocated by the Royal College of Veterinary Surgeons that the therapeutic use of anabolic steroids should be discontinued before racing.

Time budgets of older people:" a window on four lifestyles

The purposes of this research were first to describe how a group of urban elderly spend their days and, second, to examine the responsiveness of the behavioral day to rather marked environmental and personal differences. Detailed time budgets for one full day (including the content, duration, social and environmental context, and the amount of liking for each activity) were obtained from 535 persons, from four groups: independent community residents, public housing tenants, recipients of intensive in-home services, and an institutional waiting list group. Consistent patterns appeared across groups, particularly in the amount of time spent in the various social contexts and in most discretionary activities. However, the independent groups spent more time than the service groups away from home and in obligatory tasks such as housework, cooking, and shopping. Independent groups tended to express greater liking for many activities but not for more novel activities which the service groups liked equally as well.

Metabolic conjugation of some carboxylic acids in the horse

1. 14C-Labelled benzoic acid, salicylic acid and 2-naphthylacetic acid were administered orally to horses, and urinary metabolites investigated by chromatographic and mass spectral techniques. 2. [14C]Benzoic acid (5 mg/kg) was eliminated rapidly in the urine, and quantitatively recovered in 24 h. The major urinary metabolite was hippuric acid (95% of dose) with much smaller amounts of benzoic acid, benzoyl glucuronide and 3-hydroxy-3-phenylpropionic acid. Administration of [ring-D5]benzoic acid together with [14C]benzoic acid to a pony permitted the mass spectral determination of metabolites of the exogenous benzoic acid metabolites in the presence of the same endogenous compounds. 3. [14C]Salicylic acid (35 mg/kg) was eliminated rapidly in the urine, 98% of the 14C dose being excreted in 24 h. The major excretion product was unchanged salicylate (94% of dose). Gentisic acid, salicyluric acid and the ester and ether glucuronides of salicylic acid were very minor metabolites. 4. 2-Naphthyl[14C]acetic acid (2 mg/kg) was excreted very slowly in the urine, with 53 and 77% of the 14C dose being recovered in six days. 2-Naphthylacetylglycine was the major metabolite (26 and 38% dose) and in addition, the glucuronic acid and taurine conjugates were excreted together with unchanged 2-naphthylacetic acid. 5. The study has shown that the horse can utilize glycine, taurine and glucuronic acid for conjugation of xenobiotic carboxylic acids, and that the relative extents of these pathways are governed by the structure of the carboxylic acid.

Enkephalin-immunoreactive perikarya in the cat raphe dorsalis

The serotonin-containing nucleus raphe dorsalis (RD) of the cat contains numerous leucine-enkephalin immunoreactive cells, throughout its rostral-caudal extent. The distribution of the enkephalin neurons closely parallels the cytoarchitectural boundaries of the RD, as described in previous Nissl preparations. Enkephalin perikarya are most numerous along the midline of the RD, but also extend ventrally, into the dorsal portion of the nucleus centralis superior, and laterally, into the 'wings' of the rostral RD, at the level of the IV nucleus. The possible contribution of these enkephalin cells to endogenous pain control systems is discussed.

The disposition and metabolism of the synthetic prostaglandin fluprostenol (ICI 81,008) in the horse

1. Following single intramuscular doses of [14C]fluprostenol (0.5--2.4 micrograms/kg) to three female horses and to three gelded male horses, radioactivity was present in the plasma within 5 min; peak concn. (0.32--1.30 ng/ml fluprostenol equiv.) occurred 5 to 90 min after injection. Radioactivity was still present in the plasma of the females after three days. About 88% of fluprostenol is bound to plasma proteins. 2. Radioactivity was present in the parotid saliva of the gelded male horses within 10 min. Peak concn. (45--91 pg/ml fluprostenol equiv.) occurred from 5 min to 1 h after injection. Saliva : plasma concn. ratios varied inversely with saliva flow rate and limiting ratios were 0.33 and 0.41 for the combined results of two experiments on each of two male horses; the calculated value is 0.46 Chromatography indicated that the majority of plasma and saliva radioactivity was [14C]fluprostenol. 3. Excretion of radioactivity in the urine was rapid and virtually complete 12 h after dosing. The total radioactivity excreted in urine by the female horses was 45% of the dose (96 h) and by the gelded male horses 53% (30 h). About 30% of the radioactivity present in the urines was unchanged fluprostenol. 4. Faecal excretion, which was substantially complete after 2 days, accounted for 32% of the radioactivity administered to the female horses. 5. Tissue conc. of radioactivity in the female horses at four days were below the limits of detection (90 pg/g), but 0.2--0.9% of the dose was detected at the site of injection.

A gas chromatographic screening procedure for the detection of non-steroidal anti-inflammatory drugs in horse urine

A gas chromatographic screening procedure for the non-steroidal anti-inflammatory group of drugs is described. The method invovles on-column methylation of the carboxylic acid group using trimethylanilinium hydroxide as the methylating reagent. Fifteen such drugs were studied. Eight of these were detected in urine collected from horses that had received these compounds orally and for these drugs, rates of urinary excretion are recorded. Seven other members of this group of drugs were shown to be detectable by this procedure but in these cases the drug was added to urine and not administered to the horse.

Radioimmunoassay technique for detecting urinary excretion products after administration of synthetic anabolic steroids to the horse

1. Cross-bred and thoroughbred geldings were injected with veterinary doses of various synthetic anabolic steroids. Urines collected sequentially from treated animals were analysed, following solvent extraction, by radioimmunoassay using 19-[3H]nortestosterone and an antibody raised against a 19-nortestosterone immunogen. 2. Urinary excretion of 19-nortestosterone and/or its cross-reacting metabolites was detectable for various times after administration of different nortestosterone esters, as follows: phenylpropionate (400 mg), greater than 14 days; cyclohexylpropionate (100 mg), greather than 10 days; laurate (200 mg) greater than 50 days. After administration of the parent steroid (150 mg) cross-reacting compounds were detectable in urine for ca. 3 days. 3. Urinary excretion of esters of other anabolic steroids cross-reacting with the 19-nortestosterone antibody (e.g. 1-dehydrotestosterone and trienbolone) could also be followed by analysing solvent extracts of urines by the radioimmunoassay. Cross-reacting compounds in urine after administration of 1-dehydrotestosterone undecylenate (250 mg) and trienbolone acetate (75 mg) could be detected for greater than 35 days and greather than 5 days, respectively.

Studies related to the metabolism of anabolic steroids in the horse: a gas chromatographic mass spectrometric method to confirm the administration of 19-nortestosterone or its esters to horses

A method is described to confirm the presence of 19-nortestosterone metabolites in urine after the administration of veterinary preparations of this anabolic steroid to horses. The method is based upon the detection, by gas chromatography mass spectrometry or selected ion monitoring, of an isomer of estrane-3,17-diol in the urine.

A review of drug "clearance times" in racehorses

A review is presented of published and some unpublished work dealing with aspects of drug clearance from horses. This work includes plasma half-lives and urinary clearance times for specified drugs, as well as a consideration of more general factors likely to influence these values. The review is presented primarily as a guide to the veterinary surgeon in practice, to assist in the drug therapy of horses without contravening the Rules of Racing relating to doping.

Veterinary aspects of doping

Doping can improve or impair performance and can be done either deliberately or accidentally. Accidental doping to win is the offence which most concerns the veterinary surgeon. The distinction between legitimate therapy and assisting an unfit horse to win a race by giving it a drug is a fine one. General guidelines are presented for the veterinary surgeon in practice.