A Case Report of Aortic Dissection Involving the Aortic Root, Left Common Carotid Artery, and Iliac Arteries

Acute aortic dissection is a life-threatening event caused by separation of the aortic layers that requires prompt management and surgical consultation. We present the case of a 53-year-old male who developed acute, severe chest pain radiating to his back at a community hospital and was transferred to a tertiary center for definitive surgical management. The patient's aortic dissection was diagnosed via computed tomography angiography. He was started on rate-control and blood pressure medications, and was admitted emergently to the operating room. Emergency physicians should obtain immediate surgical consultation, promptly start medications for rate and blood pressure control, and administer analgesia in order to stabilize their patient and decrease the shear forces that would further propagate an aortic dissection.

Topics

Aortic dissection, cardiothoracic surgery, vascular surgery, hypertensive emergency, aorta.

Jefferson Fracture and the Classification System for Atlas Fractures, A Case Report

The Jefferson fracture classification system describes fractures of the atlas (first cervical vertebra or C1). Jefferson fractures with potential tears in the transverse ligament can cause cervical spine instability and can result in neurologic injury if not appropriately diagnosed and managed. We present the case of a 54-year-old man who fell head first with cervical spine tenderness and upper extremity paresthesias. The patient's Jefferson fracture was diagnosed via computed tomography. The patient was then treated non-operatively for his Jefferson fracture, and he had an unremarkable hospitalization. Emergency physicians should obtain surgical consultation and consider the possibility of ligamentous injury in patients suffering injury to the cervical spine.

Topics

Trauma, orthopedics, neurosurgery, cervical fracture, Jefferson fracture.

Supporting the Quadruple Aim Using Simulation and Human Factors During COVID-19 Care

The health care sector has made radical changes to hospital operations and care delivery in response to the coronavirus disease (COVID-19) pandemic. This article examines pragmatic applications of simulation and human factors to support the Quadruple Aim of health system performance during the COVID-19 era. First, patient safety is enhanced through development and testing of new technologies, equipment, and protocols using laboratory-based and in situ simulation. Second, population health is strengthened through virtual platforms that deliver telehealth and remote simulation that ensure readiness for personnel to deploy to new clinical units. Third, prevention of lost revenue occurs through usability testing of equipment and computer-based simulations to predict system performance and resilience. Finally, simulation supports health worker wellness and satisfaction by identifying optimal work conditions that maximize productivity while protecting staff through preparedness training. Leveraging simulation and human factors will support a resilient and sustainable response to the pandemic in a transformed health care landscape.

Telesimulation: An Innovative Tool for Health Professions Education

Telesimulation is a new and innovative concept and process that has been used to provide education, training, and assessment in health-related fields such as medicine. This new area of simulation, and its terminology, has its origins within the past decade. The face validity and ability to provide the benefits of simulation education to learners at off-site locations has allowed the wide and rapid adoption of telesimulation in the field of medical education. Telesimulation has been implemented in areas such as pediatric resuscitation, surgery, emergency medicine, ultrasound-guided regional anesthesia in anesthesiology, nursing, and neurosurgery. However, its rapid expansion and current use has outgrown its recent description less than a decade ago. To date, there is no unifying definition of telesimulation that encompasses all the areas where it has been used while simultaneously allowing for growth and expansion in this field of study. This article has two main objectives. The first objective is to provide a comprehensive and unifying definition of telesimulation that encompasses all the areas where it has been used while allowing for growth and expansion in the field of study. The secondary objective is to describe the utility of telesimulation for emergency medicine educators in the context of the current evidence to serve as a background and framework that educators may use when considering creating educational programs that incorporate telecommunication and simulation resources. This article is complementary to the large group presentation where this new comprehensive and unifying definition was introduced to the simulation community at the International Meeting on Simulation in Healthcare in January 2016.

Quantifying the Risk of Spinal Injury in Motor Vehicle Collisions According to Ambulatory Status: A Prospective Analytical Study

BACKGROUND

The association between ambulation at the scene of a motor vehicle collision (MVC) and spinal injury has never been quantified.

OBJECTIVE

To evaluate the association between ambulation and spinal injury in patients involved in a MVC.

METHODS

Prospective analytical-observational cohort study. Inclusion: patients sustaining traumatic injury in a MVC. Exclusion: < 18 years old, pregnancy.

PRIMARY OUTCOME

spinal injury defined as injury to the cervical, thoracic, or lumbar spinal cord, bones, or ligaments. Secondary outcome: Injury resulting in neurological deficit, need for surgery, or death. A generalized linear model was used to evaluate the association between outcome and predictor variables. Risk ratios [RR] were reported with a point estimate and 95% confidence interval (CI). A two-tailed alpha of < 0.05 was the threshold for statistical significance.

RESULTS

There were 704 patients analyzed. Nonambulatory patients were 2.29 times more likely to sustain a spinal injury, compared to ambulatory patients (RR 2.29, 95% CI 1.34-3.91). Patients ≥ 65 years of age were 3.27 times more likely to sustain a spinal injury (RR 3.27, 95% CI 1.66-6.45). Patients with a Glasgow Coma Scale score ≤ 8 were 4.93 times more likely to sustain a spinal injury (RR 4.93, 95% CI 1.86-13.10).

CONCLUSION

In this prospective analytical-observational study evaluating the association between ambulatory status and spinal injury in patients involved in MVCs, we observed that those patients who were nonambulatory were more than two times as likely to have a spinal injury compared to those patients who were ambulatory at the scene.

Race-related Healthcare Disparities Among California Workers: Public Health Considerations for Immigration Reform

BACKGROUND

Healthcare disparities are prevalent in medicine and identifying them will provide healthcare professionals, administrators, and policy makers needed information to address this public health concern.

OBJECTIVE

To evaluate racial and ethnic disparities in the rates of hospital admission and death among California workers.

METHODS

We performed an analysis of hospital and emergency department (ED) data from the Office of Statewide Health Planning and Development (OSHPD). Data was collected from California licensed acute care hospitals from 2008-2010.

INCLUSION CRITERIA

patients >15 years of age whose expected source of payment was worker's compensation.

EXCLUSION CRITERIA

patients <15 years; had missing data for age, sex, race, or injury; or were injured by a suicide attempt, poisoning, or complication of medical procedure. Multivariate logistic regression was used to evaluate the relationship of race/ethnicity and admission/death rates.

RESULTS

There were 393,298 patients discharged from the ED and 23,343 patients admitted from ED had workers compensation as their expected sources of payment and 150,277 met our inclusion criteria. The annual rate of ED treated injuries was 209/100,000 for Caucasians 343/100,000 for Hispanics, 258/100,000 for blacks and 97/100,000 for Asians. Compared to Caucasians, admission odds ratios (OR) were 1.15 (95% CI 1.07-1.25) for Hispanics, 1.08 (95% CI 0.87-1.33) for blacks, and 0.78 (95% CI 0.63-0.97) for Asians.

CONCLUSION

We observed race and ethnicity related healthcare disparities among the occupationally injured in California, with Hispanics having the highest odds of admission and annual incidence of ED treated injuries. No difference in mortality rates was observed.

A retrospective analysis of ethnic and gender differences in alcohol consumption among emergency department patients: a cross-sectional study

Background

Previous studies of alcohol use have recognized several trends in consumption patterns among gender and age yet few have examined ethnic differences. This study examines the intra- and inter-ethnic differences in alcohol consumption among a population of patients seen in the emergency department.

Methods

This is a cross-sectional study conducted in the emergency department in a large urban setting. Information on drinking behavior and ethnicity was collected using the Computerized Alcohol Screening and Brief Intervention (CASI) tool. We explored differences in drinking patterns using a multivariate multinomial logistic regression model.

Results

We analyzed the drinking habits of 2,444 patients surveyed between November 2012 and May 2014. The results indicate that when compared to non-Hispanic whites, Asians have the lowest odds of drinking within normal limits or excessively, followed by other Latinos, and Mexicans. Age and gender consistently showed statistically significant associations with alcohol-use. The odds of drinking within normal limits or excessively are inversely associated with age and were lower among females. The predicted probabilities show a marked gender-specific difference in alcohol use both between and within ethnic/racial groups. They also highlight an age-related convergence in alcohol use between men and women within ethnic groups.

Discussion

The results of this study show intra-racial/ethnic variability associated with sex and education. The highlighted differences within and between ethnic groups reinforce the need to use refined categories when examining alcohol use among minorities.

Conclusion

The results of this study confirm some alcohol consumption trends among ethnic minorities observed in literature. It provides empirical evidence of the marked gender differences and highlights an age-related convergence for gender-specific alcohol use. Health-care personnel should be aware of these differences when screening and counseling.

Simulation in medical school education: review for emergency medicine

Medical education is rapidly evolving. With the paradigm shift to small-group didactic sessions and focus on clinically oriented case-based scenarios, simulation training has provided educators a novel way to deliver medical education in the 21st century. The field continues to expand in scope and practice and is being incorporated into medical school clerkship education, and specifically in emergency medicine (EM). The use of medical simulation in graduate medical education is well documented. Our aim in this article is to perform a retrospective review of the current literature, studying simulation use in EM medical student clerkships. Studies have demonstrated the effectiveness of simulation in teaching basic science, clinical knowledge, procedural skills, teamwork, and communication skills. As simulation becomes increasingly prevalent in medical school curricula, more studies are needed to assess whether simulation training improves patient-related outcomes.

Pneumococcal vaccine administration associated with splenectomy: missed opportunities

BACKGROUND

The spleen defends against infection from encapsulated organisms. Patients who have had splenectomies are at risk for the development of overwhelming pneumococcal infections. Guidelines recommend that pneumococcal vaccine be given to all patients who have splenectomies.

METHODS

This retrospective study was performed to evaluate compliance with the guidelines in patients from a large multispecialty group practice who had splenectomies between 1988 and 1991. Ninety-five patients were identified, and their clinic and hospital records were reviewed.

RESULTS

Overall, 73.7% of patients who had splenectomies received the pneumococcal vaccine. No significant differences were found in the vaccination rates over time or among the surgeons.

CONCLUSIONS

Improvement is needed in ensuring that patients who have splenectomies receive pneumococcal vaccine.

Work-related low back injuries caused by unusual circumstances

Expanding the knowledge of issues that surround work-related injuries allows for the development of more successful work accident prevention policies, treatment and rehabilitation protocols, and education programs. Specifically, clinical observation indicated that many patients did not perceive or report the circumstances of the injury as being part of their regular duties. The objective of this study was to investigate whether unusual activities or circumstances at work played any significant role in the rehabilitation of patients with disabling low back pain. Four hundred thirty-seven patients with severe disabling pain due to work-related injuries and surgery as an option for treatment were studied. The circumstances at the time of the accident were investigated, including demographic data, type of job held at the time of injury, rapport with supervisor, recent cutbacks in job force, and number of highly related injuries. Thirty-three percent of workers were injured while performing their ordinary job duties, with lifting implicated as the most common cause of injury (66%) followed by pushing/pulling (13%). In most patients (67%), the injury occurred under unusual circumstances or activities not normally described in the worker's job routine. This finding has not been previously addressed and implies that physical therapists can improve patient confidence about rehabilitation and returning to work by educating the patients about these circumstances.

Comparing claims data and self-reported data with the medical record for Pap smear rates

The objective of this study was to assess and compare the relative accuracy of claims data and patient self-reported information with medical records for Pap smear rates. A retrospective analysis of information obtained from administrative claims files, patient medical records, and a telephone survey was performed of 400 women age 19 through 75 years who were randomly selected for participation in the study. The data were obtained from a large multispecialty group practice in Minneapolis, Minnesota for the study years 1991 through 1993. Information from administrative claims regarding Pap smear status corresponded highly with information in the medical record (sensitivity 95% or higher; specificity 95% or higher; kappa 0.896 or better). Self-reported information from the telephone survey did not correspond well with medical record information nor with results in administrative claims.

A neutrophilic drug reaction to Clomid

A 33-year-old woman treated for infertility with multiple courses of clomiphene citrate (Clomid) presented with the complaint of a rash with every course of the medication. Examination revealed petechiae and palpable purpura on her lower extremities which, histologically, were found to be consistent with a neutrophilic drug reaction. The clinical course of this unusual presentation, as well as a brief review of the neutrophilic dermatoses, are provided.

Evaluation of a nurse-based hypertension management program: screening, management, and outcomes

This article reports the experience of patients with elevated blood pressure scheduled to be seen in a nurse-based hypertension management program in a large multispecialty group practice. The hypertension management program is a screening and follow-up program designed to improve the measurement and management of patients' blood pressure with standardized protocols. The cohort for this study of the effectiveness of the hypertension management program consisted of 200 patients with elevated blood pressure (140 referred directly for management and counseling, 60 entered through screening). At entry, only 17% of the patients had blood pressure within controlled limits (< 140/90 mm Hg). One year after entry in the management phase of the program, systolic pressure had decreased an average of 6.20 mm Hg (P < 0.01), and 44% of patients had blood pressure within controlled limits (P < 0.001). These results suggest that the use of standardized screening techniques using multiple measurements helps to ensure that patients will not be unnecessarily treated. Furthermore, patients who entered the program successfully lowered their blood pressure and maintained the reduction over time.

Hypertension in the elderly

Hypertension and its cardiovascular consequences are growing medical problems in the elderly. Hypertension in older patients is characterized not only by an increase in peripheral vascular resistance, but also by a reduction in arterial compliance. These abnormalities result in marked rises in systolic pressures and variable diastolic pressures that range from markedly elevated to low-normal. Several large placebo-controlled trials have recently demonstrated that treating hypertension in elderly patients reduces cardiovascular disease. This is true in patients with systolic and diastolic hypertension as well as patients with isolated systolic hypertension. Although reduction of cardiovascular end points has only been demonstrated for thiazide diuretics and beta-blockers, it may be reasonable to include other classes of medications in the initial treatment of some elderly hypertension patients.

Detection of beta-blocker use in people with asthma

Although there have been numerous reports of adverse outcomes for people with asthma who are placed on beta-blockers, there has been no description of how often people with asthma receive prescriptions for beta-blockers. Despite the fact that pharmacy claims are available and can be used for clinical evaluation, there has been no description of a practical surveillance or warning system to recognize and reduce the rate of beta-blocker use in people with asthma. This study used administrative claims data to estimate the prevalence of patients with asthma who also had prescriptions for beta-blockers. Chart audit was used to supplement our understanding of the causes of the problem and its consequences. In the calendar year 1989, in a large midwestern group practice that contracts with a single health maintenance organization (HMO), 3,170 HMO patients presumed to have asthma were identified. Of those 3,170 patients, 44 or 1.4% also had filled prescriptions for beta-blockers. The occurrence of beta-blocker use varied by age group: from less than 1% in patients below 30 years of age, rising to 8.9% in patients aged 60 to 69. Two of the patients with asthma who had prescriptions for beta-blockers were hospitalized for asthma in the study period. In 61% of the cases, different physicians managed the asthma care from those who prescribed the beta-blockers. In the remaining 39%, one physician was responsible for both the asthma care and beta-blocker prescription. We conclude prescribing beta-blockers for individuals with asthma is not uncommon. Current systems of administrative claims data permit the development of warning systems to help avert adverse outcomes.

Patients avoiding surgery. Pathology and one-year life status follow-up

Patients were selected for a research study to determine the outcome of patients who had demonstrated enough pathology to have been viewed as surgical candidates and had chosen to avoid surgery. The purpose of the study was to identify the diagnostic categories and to obtain follow-up data on these patients. The patient population consisted of 66 patients with the following pathologies: disc disruption (one and two levels), disc disruption (three levels), stenosis, spondylolisthesis, instability, and herniated nucleus pulposus. The patients were followed for a period of 1 1/2 years and rated on the following lifestyle status categories: Returned to Work, Retired, Retraining, Able to Increase Activity Level, or No Change from Initial Status. Of the nonoperative patients, 18% returned to work. Twelve patients (18%) were retired. Eleven patients (16%) were placed in retraining programs. Twenty patients (29%) were able to increase activity level. Eleven patients (16%) fell under the category of no change.

Cerebral blood flow during the acute therapy of severe hypertension with oral clonidine

A major risk associated with the acute treatment of severe hypertension is a reduction in cerebral blood flow (CBF) with ischemic injury to the central nervous system. The authors studied CBF before and after the acute treatment of severe hypertension (diastolic blood pressure greater than 115 mm Hg) with clonidine in 13 patients. One patient did not reach goal blood pressure (diastolic blood pressure 105 mm Hg or a decrease by 30 mm Hg) after clonidine alone. In the remaining 12 patients, oral clonidine reduced supine blood pressure from 201.7 +/- 5.0/126.3 +/- 2.1 mm Hg to 149.4 +/- 5.3/96.8 +/- 1.7 mm Hg over an average time period of 85 +/- 7 minutes. Although mean CBF for the group did not change (72.6 +/- 4.2 v 73.7 +/- 3.5 mL/100 mg/min), a significant (greater than 10%) change occurred in 9 of the 12 patients (5 increases and 4 reductions). The magnitude and direction of the change were dependent upon initial CBF (r = -0.65, P less than .05); patients with low pretreatment CBF experienced an increase, whereas those with high initial flow exhibited a decrease. No significant adverse effects were observed. These data confirm previous reports that clonidine is effective in the acute treatment of severe hypertension and demonstrate that its effects on CBF are determined by the pretreatment levels of flow.

Variations in demethylation of N-methylnaltrexone in mice, rats, dogs, and humans

1. Rats and mice have a greater capacity than dogs or humans to N-demethylate the quaternary ammonium compound, N-methylnaltrexone. 2. In dogs, following the i.v. administration of N-[14C-methyl]methylnaltrexone, 50% of the radioactivity was excreted in the urine and an additional 30% in the faeces within 120 h. 3. In humans following the i.v. administration of 14C-N-methylnaltrexone, 40-60% of the radioactivity was excreted in the urine within the first 24 h. The plasma radioactivity-time curves indicated a biphasic decay and a short distribution phase between 6 and 9 min. with a longer elimination phase between 238 and 1320 min.

The development of the Dallas Pain Questionnaire. An assessment of the impact of spinal pain on behavior

The Dallas Pain Questionnaire (DPQ) was developed to assess the amount of chronic spinal pain that affects four aspects (daily and work-leisure activities, anxiety-depression, and social interest) of the patients' lives. Results of the DPQ's statistical properties suggest that the DPQ is an externally reliable instrument as well as internally consistent. Two factors emerged from factor structure analysis. Factor 1 represents functional activities and Factor 2 represents emotional capacities. A correlation analysis suggests the concurrent validity of the psychological functional factors of the DPQ. A t test demonstrated that chronic pain patients have significantly higher DPQ scores than normals. Because these findings support its statistical properties, the DPQ appears to have utility for clinical and research purposes. The findings, limitations, and implications of this study are detailed, as are suggestions for future research.

Regulation of intracellular calcium by cell pH in vascular smooth muscle cells

Intracellular calcium (Cai2+) and intracellular pH (pHi) are important regulators of a variety of intracellular processes. Cai2+ is a regulator of muscle contraction, but the role of pHi is unclear. The purpose of this study was to determine the effect of alterations of pHi on Cai2+. A7r5 vascular smooth muscle cells (VSMC) were grown to confluence on glass cover slips. Cai2+ was determined with the fluorescent probe fura-2 and pHi with 2,7-bis-carboxyethyl-5(6)-carboxy-fluorescein (BCECF). Alkalinization of the VSMC by exposure to 20 mM NH4Cl (delta pHi 0.41 +/- 0.07) resulted in a rise in Cai2+ from 99 +/- 8 to 146 +/- 13 nM (n = 5) in the presence of extracellular Ca2+ (Cao2+). In the absence of Cao2+, NH4Cl-induced alkalinization also resulted in a Cai2+ rise (delta Cai2+ = 26 +/- 4 nM, n = 5). Similar changes in Cai2+ were observed when cells were alkalinized by exposure to nigericin in a KCl buffer (pH 7.7). Neither 100 microM verapamil or 100 microM 8,8-(N,N-diethylamino)octyl-3,4,5-trimethoxybenzoate HCl (TMB-8) altered the alkaline-induced changes. After cellular Ca2+ stores were partially depleted by exposure to AVP in a Ca2+-free solution, subsequent cell alkalinization induced no changes in Cai2+. These results demonstrate that alkalinization of VSMCs leads to a rise in cytosolic Ca2+ via release of intracellular Ca2+ stores. The intracellular Ca2+ storage sites appear to be the same as those sites sensitive to AVP. Thus pHi may regulate Cai2+ and thereby play a role in the regulation of vascular smooth muscle tone.

Adenosine triphosphate depletion induces a rise in cytosolic free calcium in canine renal epithelial cells

An elevation in cytosolic free calcium (Cai) produced by cellular ATP depletion may contribute to the initiation of cytotoxic events in renal ischemia. To evaluate whether ATP depletion results in a rise in Cai we examined the effect of cyanide and 2-deoxy-D-glucose on the Cai of Madin-Darby canine kidney cells. Exposure to the metabolic inhibitors resulted in a rise in Cai from 112 +/- 11 to 649 +/- 99 nM in 15 min. This combination of metabolic inhibitors also resulted in a decrement of cell ATP to 11 +/- 2% of control by 15 min. Experiments that were performed with other metabolic inhibitors confirm that the increment in Cai is due to inhibition of ATP synthesis. With the removal of cyanide and 2-deoxy-D-glucose, Cai recovered to 101 +/- 16 nM. In the absence of extracellular calcium activity (Ca0), Cai declined from 127 +/- 7 to 38 +/- 6 nM, whereas with cyanide plus 2-deoxy-D-glucose in the absence of Ca0 the Cai rose from 108 +/- 21 to 151 +/- 28 nM. Because the rise in Cai produced by ATP depletion in the absence of Ca0 is significantly less than that which occurs in the presence of Ca0, influx of Ca0 is necessary for the maximal rise of Cai. The rise in Cai that occurred in the absence of Ca0 suggests that the release of calcium from intracellular stores contributes to the increment in Cai seen with ATP depletion. TMB-8, an inhibitor of calcium release from intracellular stores, blunted the rise in Cai by nearly 50%. Neither verapamil nor nifedipine inhibited the rise in Cai. This study demonstrates that ATP depletion induced by the metabolic inhibitors cyanide and 2-deoxy-D-glucose is associated with a rapid and reversible increase in Cai. Both Ca0 influx and Cai redistribution contribute to this rise.

Pharmacokinetic and pharmacodynamic properties of intravenous fenoldopam, a dopamine1-receptor agonist, in hypertensive patients

1 The pharmacokinetic properties of intravenous fenoldopam, a selective dopamine1-receptor agonist, were studied in 10 patients with essential hypertension. 2 Reduction in blood pressure was linearly related to the log fenoldopam plasma concentration (r = 0.69) and the log fenoldopam infusion rate (r = 0.71). 3 The mean elimination half-life (+/- s. e. mean) was 9.8 +/- 1.0 min. The total body clearance was 30.3 +/- 2.3 ml kg-1 min-1 and the volume of distribution was 582 +/- 62 ml kg-1. 4 The rapid onset of action, short elimination half-life, linear dose-response relationship, and ease of administration suggest that fenoldopam may have a role where parenteral treatment of hypertension is required.

Augmentation of renal blood flow and sodium excretion in hypertensive patients during blood pressure reduction by intravenous administration of the dopamine1 agonist fenoldopam

Activation of dopamine1 (DA1) receptors relaxes vascular smooth muscle, especially in the renal vascular bed. Fenoldopam, the first selective DA1-receptor agonist that can be administered to man, was infused intravenously in 17 patients with essential hypertension (mean blood pressure 152/101 mm Hg). It reduced blood pressure in a dose-dependent fashion at doses between 0.025 and 0.5 microgram/kg/min and the antihypertensive effect was sustained during 2 hr infusions. In 10 patients studied during free-water diuresis, fenoldopam increased renal plasma flow by 42%, glomerular filtration rate by 6%, and sodium excretion by 202%, while lowering mean arterial pressure by 12% (all p less than .05). Similar promotion of sodium excretion was observed during blood pressure reduction in six additional patients studied without water loading. Pronounced enhancement of renal function in spite of blood pressure reduction suggests that fenoldopam might have a special role in the treatment of patients with hypertension and renal impairment.

Contrast ultrasonography of the kidney: a new method for evaluation of renal perfusion in vivo

Assessment of the effects of pharmacologic agents on renal blood flow (RBF) is clinically important in many disease states, including hypertension and congestive heart failure. However, because of the complexities of RBF, quantitation in vivo has been technically difficult. This study demonstrates the utility of ultrasound imaging of the kidney combined with injection of a sonicated radiocontrast solution (Renografin-76) for the assessment of regional renal blood flow. The technique uses a suspension of uniform microbubbles (diameter 4.4 +/- 2.8 micron), which when injected directly into the descending aorta are distinctly visualized by renal ultrasound. Five dogs were studied. Catheters were placed in the descending aorta for injection of sonicated Renografin and in the renal artery for drug infusions. Data were collected before and during intrarenal artery infusions of bradykinin and norepinephrine. Total RBF was measured by electromagnetic flowmeter. Video density time curves were generated for comparable segments of the outer renal cortex and fit to a monoexponential decay curve. This allowed calculation of the mean exponential decay index (t1/2). An increase in t1/2 paralleled decreased renal perfusion (i.e., longer washout of contrast material). The opposite was true for a decrease in t1/2. Bradykinin increased RBF from 134 +/- 26 to 249 +/- 19 ml/min (p less than .01 vs control), and norepinephrine decreased RBF from 130 +/- 25 to 51 +/- 17 ml/min (p less than .01 vs control).(ABSTRACT TRUNCATED AT 250 WORDS)

Selective antagonism of the hypotensive effects of dopamine agonists in spontaneously hypertensive rats

Agonists of dopamine receptors can lower blood pressure by vasodilation through action on dopamine1 receptors, inhibition of sympathetic nerve activity by action on dopamine2 receptors, or actions in the central nervous system. Fenoldopam, a selective dopamine1 agonist, piribedil, a selective dopamine2 agonist, and dipropyl dopamine, a mixed dopamine1 and dopamine2 agonist, were injected intravenously in pentobarbital-anesthetized, spontaneously hypertensive rats (SHR). The mechanism for the antihypertensive effect was evaluated by administration of the selective dopamine1 antagonist SCH 23390 and the selective dopamine2 antagonist domperidone. While SCH 23390 only antagonized the hypotensive effects of fenoldopam, domperidone abolished the fall in blood pressure produced by dipropyl dopamine and piribedil but not by fenoldopam. Increments in heart rate and plasma norepinephrine levels accompanied the hypotensive effects of fenoldopam. The increase in heart rate was abolished by a dose of SCH 23390 sufficient to completely block the hypotensive effects and was significantly attenuated by the ganglionic blocking agent hexamethonium, which suggests that the increase in heart rate was due to a baroreceptor reflex. Fenoldopam does not cross the blood-brain barrier, which suggests that its hypotensive effect was mediated by peripheral dopamine1 receptors. Since domperidone does not cross the blood-brain barrier and significantly antagonized the hypotensive and bradycardic effects of dipropyl dopamine and piribedil, these effects were mediated primarily by peripheral dopamine2 receptors. These results indicate that SCH 23390 and domperidone are useful agents to identify the receptor subtype mediating the action of dopamine agonists in SHR.

Reduction of postoperative pain parameters by presurgical relaxation instructions for spinal pain patients

This study investigated the effects of a relaxation instruction session conducted presurgically with postsurgical pain parameters for patients undergoing spinal surgery. Results indicated that the relaxation group (n = 50) as compared with an equivalent group (n = 50) matched to type of surgery and sex type, workers compensation status had significant reduction of days of hospitalization, complaints noted by nurses, and medications (primarily demerol and phenaphen). Sex type, age, and workers compensation status were not significant factors regarding these outcome measures. The results were considered in light of the anxiety/pain explanation of pain sensitivities with implications for health care with spinal pain surgical candidates.

Human ciliary body epithelium in culture

Human ciliary body epithelial cells have been maintained in vitro and have been partially characterized by the determination of growth rate, morphology, and ultrastructural parameters. The dissection technique employed allows the separation of pure ciliary body epithelium with a predominance of cells being from the nonpigmented layer. Growth curves indicate this cell population follows a prolonged rate of growth compared to other primary cell cultures. Loss of pigment granules noted by light microscopy were documented by morphometric analysis of electron micrographs. Thirty-two percent of the cultures attempted were successful. Maintenance of these cells in vitro may provide a means for studying their enzyme systems, growth factors, reactions to various stimuli, and the effects of this cell population on other intraocular tissues.

The relationship of Minnesota Multiphasic Personality Inventory (MMPI) profile clusters to pain behaviors

Previous research involving cluster analysis of Minnesota Multiphasic Personality Inventory (MMPI) profiles among persons with chronic low back pain has suggested the existence of four distinct profile clusters. The present study had two goals: (1) to replicate the previous finding independently and (2) to investigate the relationship of the profiles to the subjects' self-reported pain history and response to treatment. Subjects were 92 patients in a multimodal inpatient low back-pain treatment program. A cluster analysis of the MMPI profiles was performed and the resultant clusters were compared in terms of histories and treatment outcome. The four clusters were successfully replicated for the total sample and for males and females separately. The profiles were significantly related to subjects' pain histories, but only one outcome difference was found. It was inferred that the MMPI is of value in understanding patients' pain coping behaviors but that further research is needed to explore the utility of the MMPI in understanding their response to treatment.

A motivational scoring system for outcome prediction with spinal pain rehabilitation patients

The aim of this study is to demonstrate an effective method of testing using the Sixteen Personality Factor Questionnaire (16 PF) along with the Minnesota Multiphasic Personality Inventory (MMPI) to predict outcome criteria in a spinal pain clinic. Using an objective system of criteria for patient achievement, including goals attained, pain estimates, psychological adjustment, medication reduction, and physical function, a quantitative method of scoring was employed to find success and failure. Using appropriately constructed testing methods, a very high level of predictability of outcome is now available. The combined use of the 16 PF and the MMPI can be relied upon to predict effective results in a spinal pain program with considerable confidence.

Classification of human colorectal adenocarcinoma cell lines

Eleven human colorectal adenocarcinoma cell lines established in this laboratory were classified into three groups based on morphological features (light and electron microscopy), modal chromosome number, and ability to synthesize carcinoembryonic antigen (CEA). Group 1 cell lines contained both dedifferentiated and differentiating cells growing in tight clusters or islands of epithelium-like cells; their modal chromosome number was about 47, and they synthesized small to moderate amounts of CEA. Group 2 cell lines were more dedifferentiated, were hyperdiploid, and synthesized small amounts of CEA. Group 3 cell lines were morphologically similar to those of Group 1 by light microscopy. They differed ultrastructurally by containing microvesicular bodies; the modal chromosome number varied from hyperdiploid to hypertriploid or they had bimodal populations of hypodiploid and hypertriploid cells, and they synthesized relatively large amounts of CEA. No correlation could be found between Broder's grade or Duke's classification of the original tumor and modal chromosome number or ability to synthesize CEA. These findings support Nowell's hypothesis that the stem line is different for each solid tumor, which makes it difficult to relate chromosomal changes to the initiation of the neoplastic state.

Morphologic and immunologic studies of a human colon tumor cell line (SW-48)

A permanent human tissue culture cell line (SW-48) has been established from an adenocarcinoma of the transverse colon. Cells in the center of early colonies were cuboidal and loosely bound; cells on the periphery of the same colonies were more columnar, the nuclei were displaced toward the basal region, and the free surface formed stunted microvilli. These columnar cells ofter aligned themselves to resemble normal absorptive tissue. Carcinoembryonic antigen (CEA) was identified by immunofluorescent microscopy on the surface membrane of the tumor cells. Significantly more CEA could be isolated from the culture medium than from the whole cells. On agar gel diffusion analysis with a monospecific anti-CEA serum (G.P. 32), SW-48 CEA and CEA preparations from solid tumors demonstrated complete identity.