Clinical Research Abstracts of the British Equine Veterinary Association Congress 2015.

REASONS FOR PERFORMING STUDY: A quantifiable measure of muscle activity related to the cervical spine may provide further understanding and evidence based support for chiropractic techniques. Surface electromyography (sEMG) is a noninvasive method of measuring muscle activity of the splenius muscle when the horse is at rest. OBJECTIVES: To determine if there is a relationship between objective measurable muscle parameters and misalignments and muscle tension in the equine cervical spine. STUDY DESIGN: Controlled paired randomised study. METHODS: Privately owned horses (n = 14), of mixed sex, age and mean height 157.8 cm were selected and assigned a group by matching work, management regime, age, sex and breed. The treatment group (n = 7) underwent manual chiropractic treatment following palpation. The control group underwent palpation only. A Delsys 4 sensor system was used for data collection. Probes were positioned on the muscle halfway between C1/C2 joint and the crest on the left and right sides, between the tendon insertion and the motor point to maximise signals. sEMG readings were taken at immediately before (0) and after palpation (PP) and 30 min later (30). Data were tested for normality and variance by one-way ANOVA and paired t test. RESULTS: Post treatment, there was a significant decrease (P<0.01) in sEMG activity for treatment group at 0 to 30 and PP to 30. There was a significant decrease (P<0.05) in sEMG for right side for treatment group at 0 to 30 and PP to 30. There were no such significant effects for the control group. The majority (83%) of horses had atlas rotation and tilt to the right. CONCLUSIONS: This preliminary study supports use of sEMG as a means of assessing muscle activity of equines and suggests a statistically significant reduction in splenius muscle activity is observed following manual chiropractic treatment although the benefit to the horse is unknown. Ethical animal research: The study protocol was reviewed by the College Research Ethics Committee before commencement of the study. Owners gave informed consent for their horses' inclusion in the study. SOURCE OF FUNDING: McTimoney College of Chiropractic assisted with the hiring of the equipment. Competing interests: None declared.

Prolactin-cell adenoma with signet-ring cells: a case report.

OBJECTIVE: Signet-ring cell changes in the pituitary adenomas are extremely rare. To date, there have been only two reports documenting signet-ring cells in pituitary adenomas, one in a growth-hormone cell adenoma and the other in a nullcell adenoma. This report describes, for the first time, signet-ring cells in a prolactincell adenoma. CASE HISTORY: The patient is a 46-year-old male who presented with severe headache and acute on chronic visual loss. Radiographic studies demonstrated a large cystic pituitary lesion with evidence of pituitary apoplexy. Laboratory values were consistent with a prolactin-cell adenoma. The patient underwent transsphenoidal resection of the prolactin-cell adenoma with significant post-operative improvement. RESULTS: The tumor was composed of sheets of monomorphic round cells with conspicuous nuclei and granular cytoplasm, consistent with pituitary adenoma. Many cells had eccentric, often crescentic-shaped nuclei, imparting a signet-ring appearance and immunostaining was positive for prolactin, denoting an atypical prolactin-cell adenoma. The MIB-1 labeling index was slightly elevated. Electron microscopy demonstrated the presence of vacuolated areas in the cytoplasm that were not membrane bound and did not have specific inclusions. DISCUSSION: This case augments the literature on pituitary adenomas with signet-ring cells. The clinical significance of signet-ring cells in pituitary adenomas is unknown. Accumulation of clinical cases, together with the advances in molecular techniques and experimental models, may yield further insight.

Fine-needle aspiration biopsy of postradiation epithelioid angiosarcoma of breast.

Angiosarcoma of breast skin and parenchyma is a rarely reported complication of irradiation for breast carcinoma. We report a case of a subareolar epithelioid angiosarcoma arising 8 years subsequent to lumpectomy and irradiation of the ipsilateral breast for infiltrating carcinoma. The epithelioid appearance of the neoplastic cells on fine-needle aspiration biopsy (FNA) biopsy suggested a recurrence of the primary carcinoma. Careful attention to certain cytomorphologic features and cell block immunohistochemistry were useful in the distinction from recurrent carcinoma. Cytologic features that identified this neoplasm as an angiosarcoma included marked cell discohesiveness, elongate cytoplasmic processes or "pseudopodia," heterogeneous cell size, large nucleoli or macronucleoli, and cytoplasmic lumina. Immunohistochemical markers, including Factor VIII antigen, CD31, and CD34, were positive, confirming the vascular nature of the neoplasm. Other markers ruled out morphologically similar neoplasms such as recurrent carcinoma and melanoma. Epithelioid angiosarcoma should be included in the differential diagnosis of a suspected recurrence of breast carcinoma several years postirradiation therapy. Diagn. Cytopathol. 2000;22:172-175.

Mixed genogroup SRSV infections among a party of canoeists exposed to contaminated recreational water.

Samples of faeces collected from a party of canoeists involved in a gastroenteritis outbreak were examined by electron microscopy and RT-PCR for evidence of infection with SRSVs. A broadly reactive primer pair was used to detect SRSVs followed by application of genogroup-specific primers to SRSV-positive specimens. Exposure data were collected by means of a questionnaire. SRSVs were detected in 1/4 specimens examined by EM and 3/4 by RT-PCR. Genogrouping, and sequencing of PCR products revealed two distinct strains: a genogroup I strain, related to the Desert Shield virus, and a genogroup II strain, related to the Lordsdale virus to be associated with the outbreak. Exposure data indicated that capsising and eating food before getting changed were associated with an increased risk of gastroenteritis and was consistent with infection following the consumption of contaminated water. This study confirms the greater sensitivity of RT-PCR for the diagnosis of SRSV infections and its utility, when incorporating genogroup-specific primers, in establishing more complex epidemiological data.

Detection of immunoglobulin M (IgM), IgA, and IgG Norwalk virus-specific antibodies by indirect enzyme-linked immunosorbent assay with baculovirus-expressed Norwalk virus capsid antigen in adult volunteers challenged with Norwalk virus.

Pre- and postexposure sera collected from 17 adult volunteers challenged with Norwalk virus as described previously (D. Y. Graham, X. Jiang, T. Tanaka, A. Opekun, P. Madore, and M. K. Estes, J. Infect. Dis. 170:34-43, 1994) were examined for Norwalk virus-specific immunoglobulin M (IgM), IgA, and IgG by indirect enzyme-linked immunosorbent assays with recombinant Norwalk virus antigen bound to the solid phase. Sixteen of the 17 volunteers had evidence of past infection, all presenting with preexisting IgG antibody of high avidity; only one volunteer had no evidence of previous infection. Virus infection was detected in 14 of the 16 volunteers with evidence of past infection, and 9 of the infected volunteers had symptomatic illness. A significant rise in both virus-specific IgA and IgG titers was detected after challenge in all of the volunteers who became ill. Five of the asymptomatic volunteers who were infected had rising titers of virus-specific IgG, but only two of the five had a concomitant rise in their virus-specific IgA antibody titers. Antibody rises were detectable in eight of nine ill volunteers 8 to 11 days after challenge but in the asymptomatic volunteers only after more than 15 days had elapsed. Virus-specific IgM was detected after challenge in all 14 infected volunteers. Between symptomatic and asymptomatic volunteers there were no significant differences in titers of virus-specific IgG and IgA in serum before challenge; however, there were significantly higher titers in symptomatic volunteers between 8 and > 90 days after challenge for virus-specific IgG and 8 and 24 days after challenge for virus-specific IgA.

Novel inhibitors of prolyl 4-hydroxylase. 3. Inhibition by the substrate analogue N-oxaloglycine and its derivatives.

N-Oxaloglycine (3) is an alpha-ketoglutarate (1) analogue that is a competitive inhibitor of prolyl 4-hydroxylase (EC 1.14.11.2). A study of the structure-activity relationships of some other oxalo derivatives shows that substitution on the glycine moiety modulates activity stereoselectively and that if the omega-carboxylate is homologated or replaced by either acylsulfonamides or anilide, then activity is sharply reduced. This sensitivity to these changes is contrasted with the relative insensitivity of another putative alpha-ketoglutarate analogue, pyridine-2,5-dicarboxylic acid (2), and the implication is discussed that compounds of both series are unlikely to bind to prolyl hydroxylase in the same way even though both inhibit the enzyme competitively.

Assay of prolyl 4-hydroxylase by the chromatographic determination of [14C]succinic acid on ion-exchange minicolumns.

An assay for prolyl 4-hydroxylase (EC 1.14.11.2) is described which measures succinic acid produced during the decarboxylation of 2-oxoglutaric acid in the presence of poly(L-Pro-Gly-L-Pro). [1-14C]Succinic acid was separated from its precursor 2-oxo[5-14C]glutaric acid by using ion-exchange minicolumns. The contamination of succinic acid by 2-oxoglutaric acid was approx. 1%, and the recovery of succinic acid was 100%. Kinetic parameters of prolyl 4-hydroxylase measured by the assay showed good agreement with published values. Our experience indicates that the measurement of prolyl 4-hydroxylase by the production of succinic acid is especially suited to investigations involving large numbers of assays.

Inhibition of prolyl 4-hydroxylase by hydroxyanthraquinones.

Prolyl 4-hydroxylase (EC 1.14.11.2) is an essential enzyme in the post-translational modification of collagen. Inhibitors of this enzyme are of potential interest for the treatment of diseases involving excessive deposition of collagen. We have found that anthraquinones with at least two hydroxy groups ortho to each other are potent inhibitors of this enzyme. Kinetic studies revealed that 2,7,8-trihydroxyanthraquinone (THA) competitively inhibited the co-substrate, 2-oxoglutarate, but was non-competitive with regard to ascorbate and was tentatively considered to be uncompetitive with regard to protocollagen. The inhibition by THA was greatly enhanced in the absence of added Fe2+ and was partially reversed by the addition of concentrations of Fe2+ in excess of the optimum for the enzymic reaction. Binding studies indicated that THA is an effective chelating agent for Fe2+. Several non-quinoidal compounds bearing the catechol moiety also inhibited the enzyme. The results suggest that THA inhibited prolyl 4-hydroxylase by binding to the enzyme at the site for 2-oxoglutarate possibly involving the Fe2+ atom, rather than by complexing with Fe2+ in free solution. The inhibition of prolyl 4-hydroxylase by THA exhibited strong positive co-operativity and may involve three distinct but non-independent binding sites.

Anti-proliferative properties of Clozic, a disease-modifying anti-arthritic agent.

Cytostatic drugs have been used in the treatment of rheumatoid arthritis but are of limited clinical application due to their severe toxic side-effects. We have discovered that 'Clozic' (ICI 55897), an agent with disease-modifying properties in rheumatoid arthritis patients, inhibits the growth of a variety of mammalian cell types including a matrix-secreting cell culture derived from neonatal rat hearts. The inhibition of growth was reversible and no loss of cell viability occurred when measured by lactate dehydrogenase released into the medium or by vital staining, suggesting a cytostatic rather than a cytotoxic mechanism. Cytostatic activity was observed at ICI 55897 concentrations within the reported therapeutic plasma concentration range and was related to the concentration of unbound compound, since the effect could be reduced by increasing the albumin concentration in the medium. Other oxyalkanoic acids inhibited cell growth. Their inhibitory potency correlated with lipophilicity. The anti-proliferative potencies of R and S enantiomers of two oxyalkanoic acids containing asymmetric centres were similar. These observations suggest that the anti-proliferative effect of the oxyalkanoic acids is due to their interaction with lipophilic cell target sites.