Postprandial arterial vasodilation in the equine distal thoracic limb

The effects of feeding on blood flow to the equine foot are poorly understood. In a temperature-controlled room, duplex Doppler ultrasonographic observations were made pre- and postprandially of the lateral proper palmar digital artery of 5 horses, randomly assigned to twice and 4 times daily feeding in an unbalanced 2 period crossover design. Arterial diameter and blood velocity were measured over 4 h and additional observations made of heart rate, blood pressure, total plasma protein, packed cell volume, plasma glucose and insulin. There was no effect of the feeding regimen on any variable. Postprandially, there were significant increases in arterial diameter, blood velocity, total plasma protein, plasma glucose and insulin; the other variables were unchanged. It appeared that the normal postprandial response was an increase in blood flow to the foot. The value of ultrasonography for noninvasive investigation of the peripheral vasculature of the conscious horse was established; and in the future it may have a role in the diagnosis of vascular diseases of the foot.     

Sonographic observations of the peripheral vasculature of the equine thoracic limb

Investigations of the equine peripheral vascular system have been constrained by the lack of a non-invasive method of examining the arteries and veins of the limbs of the conscious horse. Precise correlations were established between the gross anatomical features of the peripheral vessels and their B-mode sonographic appearance in each thoracic limb of 35 horses. A sonographic imaging protocol was established. Additional Doppler sonographic recordings defined the arterial waveforms and demonstrated that blood flow to the foot could be evaluated in the lateral proper digital artery, distal to the level of the coronary band. Valves (with 2-4 cusps) were identified in the lumina of the medial and lateral palmar common digital veins and those of the medial and lateral palmar proper digital veins. Spontaneous echo contrast, a smoke-like haze of echoic blood, was seen in the lateral and medial palmar common digital veins, the distal deep palmar venous arch and communicating branches, and the palmar proper digital veins, and occasionally seen in the distal deep palmar arterial arch and distal proper palmar digital arteries. The value of duplex sonography (B-mode and Doppler) for anatomical and physiological studies of the peripheral vasculature of the horse was clearly established. Such data could be applied to the investigation of diseases affecting the peripheral circulation.     

Versuche mit einem Prostaglandinanalog zur Zyklussynchronisation beim Rind unter hormonanalytischer und klinischer Kontrolle

1. Durch intramuskulare Injektion von 0,5 mg des Prostaglandinanalogs ICI 80 996 beim Rind während der Gelbkörperphase des Zyklus kann nach 15–24 Stunden ein Abfall der Progesteronwerte unter 1 ng/ml Blutplasma und damit eine nachhaltige Luteolyse erreicht werden. Die sich anschließende Brunst ist ovulatorisch und feral. Das Präparat wird ohne Nebenwirkungen vertragen. 2. Durch zweimalige Injektion (d. h. je 1 mal 0,5 mg i. m.) im Abstand von 11 Tagen kann dieser Luteolyseeffekt zu Brunstsynchronisationen herangezogen werden; dabei ist eine Zykluskontrolle oder Brunstbeobachtung nicht erforderlich. 3. in 8 Feldversuchen konnte bei 213 Tieren ein Synchronisationserfolg von 90,6 % und, nach KB in der 1. induzierten Brunst, ein Konzeptionsergebnis von 54,7 % (bzw. von 60,1 %, wenn man die Auswertung auf die erfolgreich synchronisierten Tiere beschränkt) erzielt werden. Die KB bei 119 nicht behandelten Kontrolltieren, die in 5 dieser 8 Versuche zur Verfugung standen, war zu 60,3 % erfolgreich. 4. In einem Problembestand konnte die Fertilitätslage durch das biotechnische Vorgehen der Prostaglandinanwendung unmittelbar nicht verbessert werden 5. Die palpatorischen Ovarbefunde zum Zeitpunkt der KB ergaben, daß Tiere mit aprungbereiten Follikeln'zu 65 %, mit kleinen, nicht reifen Follikeln zu 50,8 % und mit bereitsgesprungenen Follikeln zu 15,8 % konzipierten. 6. Die bei einem Teil der Versuche eingesetzte zusdtzliche Behandlung mit 1,0 bzw. 1,5 mg des Gonadotropin-Releasinghormons (LRH-Hoechst 471) i. m. zum Zeitpunkt der Besamung zeigte bezüglich des Konzeptionsergebnisses eine positive Tendenz.     

The relationship of plasmids from environmental Yersinia isolates and the virulence plasmid of enteropathogenic Yersinia strains

The human pathogenic strains of Yersinia harbour a conserved plasmid carrying the Yop virulon. The virulence plasmid of Yersinia enterocolitica strains belonging to the serogroups O:3 and O:9 were used as probes to detect homologous sequences in plasmids of "avirulent" Yersinia strains. "Avirulent" Yersinia strains (Y. enterocolitica biogroup 1A, Y. intermedia, Y. kristensenii and Y. frederiksenii) lack the virulence plasmid. They are widely distributed in the environment and can frequently be isolated from clinical samples. Hybridisation experiments revealed a number of common genetic elements of the virulence plasmid and the plasmids of "avirulent" Yersinia strains. These elements were identified as genes involved in plasmid replication, as an endonuclease gene and as mobile genetic elements. However, none of the plasmid encoded virulence genes was present in the plasmids of "avirulent" Yersinia strains. The frequent occurrence and the possible etiological relevance of "avirulent" isolates will be discussed.     

The bovine placenta; a source and target of steroid hormones: observations during the second half of gestation

Apart from estrone-3-sulfate (E1S) the bovine placenta produces progesterone (P4), though the corpus luteum is the major source of P4 responsible for maintaining pregnancy. So far the biological function of placental steroids in cattle is largely unknown. However, since the local availability of free estrone (E1) in the placenta seems to be controlled by sulfatase and sulfotranferase, the hypothesis was developed that placental estrogens and P4 might act as local regulatory factors. To test for such a function placentomes from 150, 220, 240, 270 days (D) pregnant and parturient cows were screened immunohistochemically for progesterone and estrogen receptors (PR, ER). PR were found at all stages in the caruncle in stromal cells and capillary pericytes but only at parturition in arterial walls. Percentage of PR-positive caruncular stromal cells (CSC) increased (P<0.05) from 51.8+/-2.6% at D150 to 58.9+/-1.8% at parturition. ER were detected in CSC, caruncular epithelial (CE) cells and in caruncular capillary pericytes. Mean percentage of ER-positive CSC decreased from 39.0+/-5.9% in pregnant cows to 17.5+/-8.3% at parturition (P<0.05). In CE all cells exhibited positive signals with the exception of those immediately surrounding large primary chorionic villi. Proliferation was assessed immunohistochemically by determining the percentage of Ki67-antigen positive cells. Highest values (P<0.001) were obtained for CE (58.0-68.3%), followed by the trophoblast (23.3-25.4%), CSC (10.6-45.3%) and the stroma of the chorionic villi (2.9-10.5%). A transient depression of proliferation in CSC between D150-270 (P<0.05) paralleled local estrogen tissue concentrations. The results suggest that placental estrogens and P4 are important factors controlling caruncular growth, differentiation and function.     

Prognostic significance of serum alkaline phosphatase activity in canine appendicular osteosarcoma

Sixty-one dogs with appendicular osteosarcoma were treated with amputation and chemotherapy of cisplatin and doxorubicin. Serum samples were obtained before and after treatment for determination of total alkaline phosphatase (TALP) activity as well as the activities of the constituent bone (BALP), liver (LALP), and corticosteroid-induced (CALP) isoenzymes. The relationship between alkaline phosphatase activities and survival was examined by Cox proportional hazards regression analysis and Kaplan-Meier log rank analysis. Mean activity of TALP, BALP, and LALP decreased significantly after treatment (P < .001). TALP and LALP activities before treatment were significantly correlated with survival (P = .006 and .001, respectively). The correlation between BALP activity before treatment and survival approached significance (P = .054). CALP activity and TALP, BALP, and LALP activities after treatment were not significantly correlated with survival. Dogs with normal pretreatment TALP and BALP activities survived significantly longer than dogs with increased pretreatment activities (P = .001 and .003, respectively). Median survival times for dogs with normal or increased TALP activities before treatment were 12.5 and 5.5 months, respectively; and median survival times for dogs with normal or increased BALP activities before treatment were 16.6 and 9.5 months, respectively. In the design of future clinical trials involving dogs with osteosarcoma, consideration should be given to stratifying the randomization according to alkaline phosphatase activity. In addition, alkaline phosphatase activity should be a factor considered by clinicians attempting to tailor the aggressiveness of adjuvant chemotherapy to the needs of individual patients or owners.