Biomedical subjects

K R Gray

Publications and source records attributed to K R Gray.

4 recordsLinked to original sources

PubMed2005

Effect of a CIDR insert and flunixin meglumine, administered at the time of embryo transfer, on pregnancy rate and resynchronization of estrus in beef cattle.

The objectives of this study were to evaluate the effects of flunixin meglumine (FM), an inhibitor of PGF(2alpha) synthesis, and insertion of an intravaginal progesterone-releasing device (CIDR), on pregnancy rates in beef cattle embryo transfer (ET) recipients, and to examine the effect of a CIDR after embryo transfer on the synchrony of the return to estrus in non-pregnant recipients. Cows (n=622) and heifers (n=90) at three locations were assigned randomly to one of four groups in a 2x2 factorial arrangement of treatments with FM administration (500 mg i.m.) 2-12 min prior to ET, and insertion of a CIDR (1.38 g progesterone) immediately following ET as main effects. Fresh or frozen embryos (Stage=4 or 5; Grade=1 or 2) were transferred on Days 6-9 of the estrous cycle and CIDR devices were removed 13 days after ET. Recipients at Location 2 only were observed for signs of return to estrus. Recipients that returned to estrus at Location 2 were either bred by AI or received an embryo 7 days after estrus. Following the initial ET, there was an FMxlocation interaction on pregnancy rate (P<0.01; Location 1, 89% versus 57%; Location 2, 69% versus 64%; Location 3, 64% versus 67% for FM versus no FM, respectively). Pregnancy rates of embryo recipients were not affected by CIDR administration (P>0.05; 65% with CIDR, 70% without CIDR), however, the timing of the return to estrus was more synchronous (P<0.01) for recipients given a CIDR. Pregnancy rate of recipients bred following a return to estrus did not differ between cows receiving or not receiving a CIDR for resynchronization (P>0.13). Effects of FM on pregnancy rate were location dependent and CIDR insertion at ET improved synchrony of the return to estrus.

Administration, Intravaginal↗

PubMed2001

Reed bed dewatering of agricultural sludges and slurries.

In trials at Rugeley, UK, reed beds were used for dewatering agricultural sludges and slurries. Three beds, each of 3.5 m2, were employed, two planted with Phragmites australis, the third left unplanted as control. The sludge contained partly oxidised solids from a Biological Aerated Filter (BAF) treating weak pig slurry. It was supplemented with untreated settled pig slurry. Following reed establishment planted Bed A was fed at a constant similar rate to the unplanted Control Bed C. The second planted Bed B was fed at higher rates alternating with rest periods. On this bed the aeration pipes were blocked off. The trials were run for 16 months, which included two summer periods. The results showed that the planted Bed A had definitely better dewatering ability than the unplanted one fed at a similar rate. During the summer months Bed B could be fed at over twice the rate used for the constant input beds. The percolate from the control bed was more highly oxidised than from the planted beds, probably due to a longer holdup time in the absence of reeds. On Bed B the reed quality deteriorated during the second year, after use of untreated slurry as feed.

Agriculture↗

PubMed1994

Latex induced anaphylaxis: a case report.

The case of a 42-year-old latex-sensitive female who experienced urticaria, pruritus, soft tissue swelling, and significant hypotension during an outpatient barium enema is described. These signs and symptoms of anaphylaxis occurred immediately after enema tip insertion and before infusion of contrast material. The patient responded well to appropriate emergency therapy and her symptoms resolved in a 24-hour period. Subsequent radioallergosorbent test showed an elevated immunoglobulin E (IgE) level to latex, and the skin prick test produced significant induration and erythema in response to latex. This patient experienced an IgE-mediated anaphylactic reaction to the latex enema tip. Emergency physicians need to be aware of the spectrum of latex-induced allergic reactions.

Adult↗

PubMed1988

Hemodynamic recovery during simulated ventricular tachycardia: role of adrenergic receptor activation.

Ventricular tachycardia (VT) produces a wide variety of hemodynamic outcomes. Variations in autonomic nervous system response were studied in an animal model of VT. In 18 dogs anesthetized with chloralose VT was simulated by ventricular pacing (rate 240 bpm). Dynamic changes in left ventricular (LV) function were assessed during sinus rhythm and after VT was initiated, under variable autonomic conditions: ganglionic blockade with hexamethonium (n = 5), alpha-adrenergic blockade with terazosin (n = 7; 0.3 mg/kg), and beta-adrenergic blockade with propranolol (n = 6; 2 mg/kg). Micromanometers were used to measure LV pressure, and endocardial piezo crystals assessed changes in cavity size. Sinus interval, an index of autonomic tone, was determined immediately after tachycardia was terminated. Under control conditions the onset of simulated VT was accompanied by severe hypotension, with a decline in LV systolic pressure from 113 +/- 5 to 67 +/- 4 mm Hg within 10 seconds (p less than 0.05). Subsequently, during persistent tachycardia peak LV pressure recovered to sinus values, and maximum +dP/dt exceeded sinus values by 20 seconds (2604 +/- 413 vs 2112 +/- 184 mm Hg/sec; 20 seconds for VT vs sinus rhythm). Diastolic pressures were unchanged, and sinus rate accelerated. Ganglionic blockade with hexamethonium resulted in persistent hypotension, blunted +dP/dt, no change in diastolic pressures, and failure of the sinus rate to accelerate after the tachycardia. After beta blockade there was sustained hypotension (LV systolic pressure 78 +/- 4 vs 120 +/- 5 mm Hg; 20 seconds for VT vs sinus rhythm), maximum +dP/dt was blunted, and minimum diastolic ventricular pressure rose. This was due to an upward shift in the diastolic pressure-dimension relationship associated with prolongation of the time constant of LV relaxation. The sinus interval did not change. In contrast, tachycardia during alpha blockade produced a sustained fall in peak LV pressure; however, maximum +dP/dt recovered (2194 +/- 328 vs 2154 +/- 153 mm Hg/sec; 20 seconds for VT vs sinus rhythm), minimum diastolic LV pressure remained low, and sinus rate accelerated after ventricular tachycardia. Hemodynamic recovery during ventricular tachycardia is mediated by the response of the autonomic nervous system and requires both alpha-adrenergic vasoconstriction and beta-adrenergic augmentation of contraction and relaxation.

Adrenergic alpha-Antagonists↗