Rats were trained to press two levers in alternation on discrete trials spaced 10 sec apart. During the final sessions of alternation training, error responses per opportunity on the trials that followed reinforced trials (initial trials) did not differ from error responses per opportunity on repetitive (correction) trials (Experiment 1). Scopolamine did not increase the rats' tendency to perseverate: drug treatment did not cause the error responses per opportunity to increase over runs of consecutive error responses (Experiment 2). Scopolamine did not impair performance when alternation was controlled by visual stimuli present in the external environment at the time of the response (Experiment 3). The disruption in delayed alternation performance produced by scopolamine was attributed to effects on stimulus discrimination, resulting in impairment of control of responding by stimuli not present in the environment at the time of the response.

Animals↗

PubMedDate not supplied

Latent transition analysis to the stages of change for smoking cessation.

A key construct of the Transtheoretical Model of Behavior Change is the stage of change (Precontemplation, Contemplation, Preparation, Action, and Maintenance) (Prochaska & DiClemente, 1983, 1986). This study applies Latent Transition Analysis (LTA; Collins & Wugalter, 1992; Collins, Wugalter, & Rousculp, 1991) to movement through the stages of change for smoking cessation. LTA is an alternative method of assessing categorical outcome that is sensitive to change, diagnostic, and allows for the comparison of alternative models of change. The sample consisted of 545 reactively recruited smokers and former smokers who were assessed five times over a two year period. LTA was used to compare three specified models. The model that fit the data best indicates that in a six month time frame both progression and regression among the stages takes place as well as two stage progression. Examination of the probability of movement among the stages revealed three findings consistent with the Transtheoretical Model. First, movement through the stages is not always linear. Second, the probability of forward movement was greater than backward movement. Third, the probability of moving to adjacent stages was greater than the probability of two stage progression.

Adult↗

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Objectives to direct the training of emergency medicine residents on off-service rotations: neurology.

This is the twenty-first article in a continuing series of objectives to direct resident training in emergency medicine. Presented is a set of objectives with references for curriculum goals in neurology. Knowledge of neurology and clinical skills in diagnosing neurological illness is important in the practice of emergency medicine. Not all emergency residents have adequate exposure to the subspecialty of neurology. Many residents who have exposure to a neurology elective often spend only two weeks on the service. Therefore, a clear set of goals and objectives is essential for the resident to obtain a comprehensive knowledge of this complex specialty.

Curriculum↗

PubMedDate not supplied

Ovarian hyperstimulation syndrome in the emergency department: a case report.

The Ovarian Hyperstimulation Syndrome (OHSS) is a complication of ovulation enhancing technologies that is becoming more prevalent with increasing use of these techniques in infertile women. In this report, we describe a 36-year-old woman who presented to the Emergency Department with hemodynamic compromise secondary to OHSS. The OHSS is characterized by ovarian enlargement, ascites, electrolyte disturbances, hypotension, and thromboembolic events. This case illustrates a serious complication of techniques used to enhance fertility.

Adult↗

PubMedDate not supplied

Use of o-phthaldehyde derivatives and high-pressure liquid chromatography in determining the free amino acids in cocoa beans.

Explore the source record for details and available documents.

Aldehydes↗

PubMedDate not supplied

Effects of epidural anesthesia on microcirculatory blood flow in free medial saphenous fasciocutaneous flaps in dogs.

OBJECTIVE: To assess the effects of epidural anesthesia using lidocaine on microcirculatory blood flow, volume, and velocity in free fasciocutaneous flaps in dogs. Study Design-In vivo experimental investigation. Animal Population-Ten adult dogs weighing 20 to 25 kg. METHODS: A medial saphenous fasciocutaneous free flap was removed and an orthotopic transfer was performed by anastomosing the primary flap vessels back to the medial saphenous vessels. Blood flow (mL(LD)/min/100 g), volume (%volume or tissue hematocrit) and velocity (mm/s) in the flap were recorded throughout the procedure. After epidural anesthesia, blood flow, volume, and velocity values were again recorded. RESULTS: Microcirculatory blood flow, volume, and velocity, as measured by a laser-Doppler flowmeter, failed to reveal any significant changes over time. Immediately after epidural anesthesia, mean arterial pressure was significantly reduced and remained depressed throughout the experimental procedure. CONCLUSIONS: Epidural anesthesia combined with general anesthesia does not improve microcirculatory flow in free flaps in the pelvic limbs of dogs. No significant change in blood flow to the medial saphenous fasciocutaneous free flap occurred after division and anastomosis of the vascular pedicle. CLINICAL RELEVANCE: We recommend that epidural anesthesia with 2% lidocaine be used with caution in dogs undergoing microvascular free-flap transfer.

Anesthesia, Epidural↗

PubMedDate not supplied

Transdiaphragmatic approach to thoracic duct ligation in the cat.

An approach combining ventral midline celiotomy with transdiaphragmatic thoracotomy was evaluated in eight healthy cats for ligation of the thoracic duct system. Evans Blue solution was injected into the right colic lymph node to outline the intestinal lymphatic trunk and the thoracic duct system. Three cats (group 1) had mesenteric lymphangiograms and three (group 2) had only lymph node dye injection before thoracic duct ligation. The thoracic duct system was ligated with hemostatic clips just cranial to the aortic hiatus of the diaphragm, through a left transdiaphragmatic thoracotomy. Two cats (group 3) had prethoracotomy mesenteric lymphangiograms and thoracic duct isolation without ligation. Mesenteric lymphangiography was performed immediately after the surgery. In all of the cats, an absence of contrast medium in the thoracic duct system cranial to the surgical site was interpreted as complete obstruction. Four weeks after ligation, there was complete obstruction of the thoracic duct system with alternate lymphaticovenous communications in four of the six cats with ligated thoracic duct systems. Partial obstruction of the thoracic duct system with alternate lymphaticovenous communications was present in the other two cats. Both cats without thoracic duct ligation had patent thoracic duct systems. At necropsy of the six cats with ligated thoracic ducts, there was mild focal lymphadenitis of injected lymph nodes in three cats. The wall of the aorta adjacent to the hemostatic clips was normal in all six cats. The surgical technique was simple and provided excellent exposure. Vital staining with Evans Blue helped visualize the thoracic duct system, but mesenteric lymphangiography did not. Postligation lymphangiography was not of value in identifying incomplete ligation.

Animals↗

PubMedDate not supplied

Healing characteristics of free and pedicle fat grafts after dorsal laminectomy and durotomy in dogs.

Dorsal laminectomy and durotomy were performed at thoracic vertebrae 12 and 13 (T12-T13) and lumbar vertebrae 1 and 2 (L1-L2) in 12 normal dogs. A free fat graft harvested from subcutaneous tissue adjacent to the incision was placed over the T12-T13 laminectomy site. A 75 X 25 X 5 mm pedicle fat graft harvested from a similar location was placed over the L1-L2 laminectomy site. Three dogs each were euthanatized at weeks 2, 4, 8, and 16. With both types of fat grafts, an initial inflammatory stage reduced the size of the graft approximately 50%. Axonal degeneration and demyelination of the spinal cord resolved by week 16. At week 16, the durotomy sites had healed, but the dura mater was adhered to the spinal cord. No difference between the grafts could be demonstrated by antemortem myelography and cerebrospinal fluid analysis. There was no demonstrable advantage to the use of pedicle fat grafts.

Adipose Tissue↗

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Transsplenic portal catheterization. Surgical technique and use in two dogs with portosystemic shunts.

The portal vasculature can be accessed by using a through-the-needle catheter system to pass a catheter through the splenic parenchyma and into a major splenic vein at the hilus. The authors have termed this technique transsplenic portal catheterization (TPC). Transsplenic portal catheterization is indicated for portal angiography, portal pressure measurement, and chronic portal blood sampling. Clinical applications of this technique include use in diagnosis and surgical management of portosystemic shunts and differentiation of prehepatic, hepatic, and posthepatic hypertension. This report describes the technique of transsplenic portal catheterization. Clinical use of this technique in two cases of portosystemic shunts are included.

Animals↗

PubMedDate not supplied

Controlled cross circulation in dogs: effects on donor hemodynamics.

Controlled cross circulation (CCC) was performed in six pairs of dogs for 45 minutes with aortic cross clamping and cardioplegia. Data were collected in donor dogs at 10 minute intervals three times before, three times during, and three times after CCC and included arterial blood pressure, pulmonary capillary wedge pressure (PCWP), central venous pressure (CVP), cardiac index (CI), heart rate (HR), blood gas analysis, temperature, maximum rate of rise of left ventricular pressure dP/dt max/End diastolic volume (EDV), blood volume (BV), complete blood count (CBC) and activated clotting times (ACT). Pulse pressure (PP), systemic vascular resistance (SVR), oxygen delivery (DO2), and left ventricular cardiac work (LVCW) were calculated. Arterial blood pressure, CVP, blood gas analysis, temperature, BV, CBC, and ACT were measured in recipient dogs. During CCC, donor hemodynamic changes resembled those observed in models of acute onset arteriovenous fistulas. Insidious BV shifts can occur despite the use of occlusive roller pumps. After CCC, donor hemodynamics resembled acute blood loss, characterized by decreases in mean arterial pressure (MAP), CVP, PCWP, and CI, and increases in SVR and dP/dt max/EDV. These changes were probably caused by pump imbalance and BV shift to the recipient dog.

Animals↗