Activation of androgen receptor-expressing neurons in the posterior medial amygdala is associated with stress resistance in dominant male hamsters.

Social stress is a negative emotional experience that can increase fear and anxiety. Dominance status can alter the way individuals react to and cope with stressful events. The underlying neurobiology of how social dominance produces stress resistance remains elusive, although experience-dependent changes in androgen receptor (AR) expression is thought to play an essential role. Using a Syrian hamster (Mesocricetus auratus) model, we investigated whether dominant individuals activate more AR-expressing neurons in the posterior dorsal and posterior ventral regions of the medial amygdala (MePD, MePV), and display less social anxiety-like behavior following social defeat stress compared to subordinate counterparts. We allowed male hamsters to form and maintain a dyadic dominance relationship for 12 days, exposed them to social defeat stress, and then tested their approach-avoidance behavior using a social avoidance test. During social defeat stress, dominant subjects showed a longer latency to submit and greater c-Fos expression in AR+ cells in the MePD/MePV compared to subordinates. We found that social defeat exposure reduced the amount of time animals spent interacting with a novel conspecific 24 h later, although there was no effect of dominance status. The amount of social vigilance shown by dominants during social avoidance testing was positively correlated with c-Fos expression in AR+ cells in the MePV. These findings indicate that dominant hamsters show greater neural activity in AR+ cells in the MePV during social defeat compared to their subordinate counterparts, and this pattern of neural activity correlates with their proactive coping response. Consistent with the central role of androgens in experience-dependent changes in aggression, activation of AR+ cells in the MePD/MePV contributes to experience-dependent changes in stress-related behavior.

Nitrogen balance and calorie efficiency in small-for-date dwarfism.

Accelerated weight gain was induced in eight infants, including two patients with dwarfing syndromes, who were small for their dates of birth and continued to be small after birth. The calorie cost of weight gain was higher than in control infants with linear growth failure due to undernutrition, but the degree of inefficiency did not seem to be of practical significance. Nitrogen retentions were appropriate for weight gain or better. Nitrogen retentions in excess of those expected on the basis of weight gain were seen in infants with small-for-date dwarfism and in controls when calorie intakes were low. The ability to induce good nitrogen retentions is thus no reflection of linear growth potential.

Vegetarian food guide pyramid: a conceptual framework.

The purpose of this article and the accompanying vegetarian food guide pyramid graphic is to provide the conceptual framework for the development of a new and unique food guide. Food guides for vegetarians have tended to be adaptations of guides developed for the general nonvegetarian population instead of being designed to emphasize the healthy components of vegetarian dietary patterns. A subcommittee of the organizers of the Third International Congress on Vegetarian Nutrition began a process that led to the development of a pyramid-shaped graphic illustration and a supporting document, both of which were introduced at the congress. The 5 major plant-based food groups (whole grains, legumes, vegetables, fruit, nuts, and seeds) form the trapezoid-shaped lower portion of the pyramid. Optional food groups, which may be avoided by some vegetarians (vegetable oils, dairy, eggs, and sweets), form the smaller, separate, triangle-shaped top portion of the pyramid. The supporting document discusses the concepts that affect vegetarian food guidance and the rationale for selecting the food groups. It is hoped that this framework will provide the impetus for further research and discussion and will lead to the development of a guide that is nutritionally adequate, is conducive to good health, and can be adopted by vegetarians of diverse eating practices.

The relationship between fetal hemoglobin and disease severity in children with sickle cell anemia.

A study was conducted in a sample of 140 children with sickle cell anemia to evaluate the relationship between hematological variables (%HbF, %HbA2, %Hb, and mean cell volume) and disease severity. A patient's severity status was determined by whether he/she was hospitalized, had a transfusion, and/or had a pain crisis at 2 evaluation periods; the first was based on a patient's history taken at the initial assessment visit to the Wayne State Comprehensive Sickle Cell Center, and the second was based on a 1-3 year follow-up at the center. Fetal hemoglobin was a strong predictor of a patient's hospitalization and transfusion status. A decrease in %HbF of 4.76% (one SD of %HbF) was associated with a 3.58 fold (95% confidence interval, 1.18-7.28) greater odds of being hospitalized both prior to initial assessment and on follow-up, compared to not being hospitalized at either evaluation. Similarly, a decrease in %HbF of 4.76% was associated with a 5.56 fold (95% confidence interval, 1.67-18.96) greater odds of having a transfusion both prior to initial assessment and on follow-up compared to not having a transfusion at either evaluation. Patients who were both hospitalized and transfused at initial assessment and on follow-up (n = 12) had a mean %HbF of 7.59%, while patients who were not hospitalized or transfused at either evaluation (n = 19) had a mean %HbF of 13.61%. Fetal hemoglobin was not a significant predictor of pain crises in this sample of patients. None of the other hematological variables were significant predictors of disease severity in this study. The strong relationship between %HbF and disease severity identified in this study suggests that a single %HbF measurement may be useful in predicting important aspects of the clinical course of children with sickle cell anemia.

Stability over time of hematological variables in 197 children with sickle cell anemia.

One hundred ninety-seven children with sickle cell anemia were followed for 4 years at the Wayne State Comprehensive Sickle Cell Center to evaluate the stability of the hematological variables (Hb, Hct, RBC count, MCV, %HbF and %HBA2) over time. The mean values of the hematological measurements taken during three separate 16-month intervals were used to represent an individual's values. The correlations of the hematological variables between intervals ranged from a low of 0.46 for %HBA2 to a high of 0.91 for %HbF. Correlations that spanned two intervals (an average of 32 months) were of the same magnitude as those that spanned only one interval (an average of 16 months), suggesting that there was no decrease in the degree of stability of these variables as the time between measurements increased. The stability of the correlations between variables within intervals, and the stability of the coefficients of the first two principal components of the six hematological variables over time suggested that the relationships among variables were also stable. In a recent report [Odenheimer et al, 1983], we used the values of the six hematological variables collected at an individual's first visit to the sickle cell center to identify four hematologically distinct subgroups of children. In the current report, we found that as many as 83% of the individuals remained in the same subgroup in at least two of the three follow-up intervals, suggesting that the factors that contributed to this classification were the result of stable, rather than transient phenomena.

Abdominal wall mass in a pregnant woman.

Abdominal fibromatosis should be considered in female patients of childbearing age who present with a mass arising from the abdominal musculature, particularly if the mass becomes evident during or immediately after gestation. Magnetic resonance imaging, with its multiplanar imaging capabilities, is useful in characterizing soft tissue tumors and in defining the extent of tumor involvement of adjacent structures.

Curriculum for musculoskeletal radiology.

Although general suggestions have been made regarding a radiology residency curriculum, no specific list of entities has been offered. Over the past ten years, we have developed a resident-run morning conference in musculoskeletal radiology that is supervised by faculty and covers a specific curriculum. We offer our curriculum as an example that may assist other departments in developing their own curricula.

Pump prime only aprotinin inhibits cardiopulmonary bypass-induced neutrophil CD11b up-regulation.

BACKGROUND: The expression of neutrophil integrin CD11b is up-regulated after cardiopulmonary bypass (CPB) and is the neutrophil adhesive molecule of most importance in neutrophil- endothelial adherence. This neutrophil-endothelial adherence is responsible for post-CPB neutrophil-induced reperfusion injury. Low-dose aprotinin protocols inhibit the CPB-induced neutrophil CD11b up-regulation. This investigation was undertaken to evaluate the effects of pump prime only aprotinin (280 mg) on the CPB-induced up-regulation of this neutrophil integrin. METHODS: Twenty-two patients scheduled for elective myocardial revascularization were randomized into two groups: (1) control (n = 12), or (2) pump prime only aprotinin (280 mg) (n = 10). Neutrophils were isolated at baseline, 50 minutes of CPB, and 30 minutes after CPB and neutrophil CD11b expression was measured. RESULTS: The control group demonstrated a significant (p < 0.05) increase in neutrophil CD11b immunofluorescent staining at 50 minutes of CPB and at 30 minutes after CPB when compared to same group baseline and to the pump prime only aprotinin group at similar time intervals. CONCLUSIONS: These results indicate that pump prime only aprotinin modulates the CPB-induced up-regulation of neutrophil CD11b integrin, an important indicator of the systemic inflammatory response to CPB. In addition to blunting of the CPB-induced up-regulation of this neutrophil integrin expression, this pump prime only dose of aprotinin is also reported to be effective at reducing post-CPB bleeding and transfusion requirements. This salutary effect of pump prime only aprotinin suggests that such low-dose regimens can be both therapeutically effective and cost effective.

Aprotinin for primary coronary artery bypass grafting: a multicenter trial of three dose regimens.

BACKGROUND: High-dose aprotinin reduces transfusion requirements in patients undergoing coronary artery bypass grafting, but the safety and effectiveness of smaller doses is unclear. Furthermore, patient selection criteria for optimal use of the drug are not well defined. METHODS: Seven hundred and four first-time coronary artery bypass grafting patients were randomized to receive one of three doses of aprotinin (high, low, and pump-prime-only) or placebo. The patients were stratified as to risk of excessive bleeding. RESULTS: All three aprotinin doses were highly effective in reducing bleeding and transfusion requirements. Consistent efficacy was not, however, demonstrated in the subgroup of patients at low risk for bleeding. There were no differences in mortality or the incidences of renal failure, strokes, or definite myocardial infarctions between the groups, although the pump-prime-only dose was associated with a small increase in definite, probable, or possible myocardial infarctions (p = 0.045). CONCLUSIONS: Low-dose and pump-prime-only aprotinin regimens provide reductions in bleeding and transfusion requirements that are similar to those of high-dose regimens. Although safe, aprotinin is not routinely indicated for the first-time coronary artery bypass grafting patient who is at low risk for postoperative bleeding. The pump-prime-only dose is not currently recommended because of a possible association with more frequent myocardial infarctions.

Postbaccalaureate program at Wayne State University School of Medicine: a 30-year report.

In 1969, Wayne State University School of Medicine established the first postbaccalaureate program for medical students, with the focus on African American students whose applications to medical school had been rejected. The ten-month program was designed to improve students' scientific knowledge, academic skills, and personal adjustment and thereby ultimately to increase the number of African Americans enrolled in the school. The criteria included the quality of the student's high school, employment workload, parents' ability to assist financially, and several other factors. The school covered expenses, provided a living stipend, and guaranteed admission for students who attained a B average in the program. Consistent with the Bakke court decision, in 1979 the program eligibility was shifted to disadvantaged students irrespective of race or ethnicity; all other criteria remained unchanged. Until 1990 Wayne State University's program was the only one of its type. From 1969 to 1992, 214 African American students who could have graduated by 1997 had been admitted to the program: 192 (90%) of them attained a B average in the program and matriculated in the medical school, and 160 (83%) graduated. From 1978 (when the program was opened to all racial and ethnic groups) to 1992, 58 non-African American students who could have graduated by 1997 were been admitted to the program: 54 (93%) attained a B average and matriculated in the medical school, and 51 (94%) graduated. The program's success suggests that similar programs at more medical schools could have an immediate and substantial impact on the number of underrepresented-minority students who enter medical education and succeed.

Breeding structure of screwworm fly populations (Diptera: Calliphoridae) in Colima, Mexico.

Starch gel electrophoresis was used to resolve gene frequencies among populations of screwworm, Cochliomyia hominivorax (Coquerel). The loci examined coded for alpha-glycerophosphate dehydrogenase, octanol dehydrogenase, and phosphoglucomutase. Flies were sampled by traps widely distributed in Colima Province, southwestern Mexico. Gene frequencies at Odh differed significantly among the 11 populations. Alleles segregating at Pgm and alpha-Gpdh were homogeneous among populations. There were significant departures from random mating within populations, but no genetic differentiation among populations was detected. The data suggest unrestricted gene flow among populations. Departures from random mating within populations were explained by the pooling of samples from separate breeding units.

Fluid therapy and the resuscitation of traumatic shock.

Fluid management of the traumatized patient begins with assessment of volume status via palpation of pulses; evaluation of mental status; and measurement of urine output, arterial blood pressure, and central pressures. Intravascular line placement and choice of initial resuscitation fluids should be individualized to the clinical situation, although in most situations a crystalloid solution continues to be the initial fluid of choice. Following initial stabilization, the intravenous fluid administered can be tailored to a given situation, chosen only after the deranged fluid balance is sequentially classified according to alterations of volume, concentration, and composition. Parenteral fluids may be divided into two groups: crystalloids and colloids. The indications, complications, and controversies surrounding various resuscitation modalities have been reviewed.

Sickle cell.

The initiation of newborn screening and its virtually universal implementation will eventually yield a population in which sickle cell disease has been identified and comprehensive care is provided for children. The situation with SCT is different; there will continue to be the identification of parents who have the potential for having a child with a sickle cell disease but because they will not be tested or counseled, there will continue to be a population of children with a sickle cell disease whose parents have not been enabled to make informed decisions that they believe are in their best interest relative to family planning. Also, we will continue to have a population of pregnant women with a fetus with sickle cell disease who will not be given an opportunity to decide whether they wish to continue or terminate the pregnancy. They all will give birth to a child with a lifetime of chronic illness with its associated psychological, social, and financial burdens for the individual and his or her parents. The failure to implement prenatal diagnosis is an abridgment of two fundamental rights: the right to know and the right to decide. In this case it is the right to know about the potential health status of their children if that is possible, and the right to decide about the actual health care status of their children if options are available.

Liver uptake of Tc-99m PYP.

A 23-year-old man with extensive liver uptake of Tc-99m PYP secondary to cocaine-induced hepatotoxicity is presented. This is the first case reported in the radiology literature.

Administration of high-dose aprotinin during nonprimary cardiovascular surgery: case reports and review of the literature.

The perioperative management of two patients undergoing complex "redo" cardiac surgical procedures are presented. The management of both patients included the prophylactic administration of aprotinin via a "compassionate use" protocol. Aprotinin, a serine protease inhibitor, has been shown to limit the exposure to blood and blood products in patients undergoing high-risk cardiac surgical procedures. In late December 1993, the Food and Drug Administration approved aprotinin for administration to cardiac surgical patients considered at high risk for post-cardiopulmonary bypass coagulopathies. Indications for the administration of aprotinin, as well as a brief review of the literature relating to the perioperative administration of aprotinin, are included.

Management of a postpartum coagulopathy using thrombelastography.

Thrombelastography (TEG), which evaluates the elastic properties of whole blood and provides a global assessment of hemostatic function, is useful in managing peripartum coagulopathy. A case of severe bleeding after vaginal delivery, in which TEG was used successfully to manage hemostatic defects, is presented.

Effects of pretreatment with cisatracurium, rocuronium, and d-tubocurarine on succinylcholine-induced fasciculations and myalgia: a comparison with placebo.

STUDY OBJECTIVE: To evaluate the efficacy of cisatracurium, rocuronium, and d-tubocurarine in preventing succinylcholine-induced fasciculations and postoperative myalgia in patients undergoing ambulatory surgery. DESIGN: Randomized, prospective, placebo-controlled trial SETTING: Teaching hospital. SUBJECTS: 80 ASA physical status I and II patients scheduled for elective ambulatory surgery with general anesthesia. INTERVENTION: A standardized balanced anesthetic technique was used for all patients. MEASUREMENTS AND MAIN RESULTS: Patients were randomized to receive cisatracurium 0.01 mg/kg, rocuronium 0.06 mg/kg, d-tubocurarine 0.05 mg/kg, or saline, 3 minutes prior to intravenous (i.v.) succinylcholine 1.5 mg/kg. The intensity of fasciculations and intubating conditions were assessed using a four-point rating scale. In addition, the severity of myalgia was assessed using a four-point rating scale in the postanesthesia care unit and at 24 hours postoperatively. No patient complained of any side effects after the administration of the study drug. Fasciculations were observed less frequently (p < 0.05) in the d-tubocurarine and rocuronium groups compared with the placebo and cisatracurium groups. However, there was no difference between the d-tubocurarine group and the rocuronium group (21% vs. 10%, respectively). Although fasciculations occurred less frequently in the cisatracurium group than in the placebo group (59% vs. 85%, respectively), this difference did not reach statistical significance. There was no difference among the four groups in the intubating conditions or the incidence of postoperative myalgia. CONCLUSION: Pretreatment with rocuronium and d-tubocurarine was superior to cisatracurium in preventing succinylcholine-induced fasciculations. However, pretreatment did not have any effect on the incidence of myalgia after ambulatory surgery.

Influence of ketorolac tromethamine on clot elastic strength in humans as assessed by thromboelastography.

STUDY OBJECTIVE: To evaluate the effect of ketorolac tromethamine on coagulation using thromboelastography (TEG). DESIGN: TEGs were performed in each patient before and after ketorolac administration. Each patient's predrug results were used as control measurements for comparison with the postdrug results. SETTING: Medical center surgical unit. PATIENTS: Twenty ASA physical status I and II patients undergoing minor elective surgery; 12 healthy volunteers. INTERVENTIONS: TEGs were performed in all subjects before and 60 minutes after the intramuscular (IM) administration of ketorolac tromethamine 60 mg. Ten surgical patients were studied in the intraoperative period, and 10 surgical patients were studied in the postoperative period. The 12 healthy volunteers did not undergo a surgical procedure. MEASUREMENTS AND MAIN RESULTS: Specific parameters assessed from the TEGs were reaction time (R time), coagulation time (RK time), clot formation rate (angle of deflection), and maximum clot strength (maximum amplitude of deflection). Ketorolac administration did not cause statistically significant changes in these parameters in any of the three groups studied. CONCLUSIONS: IM administration of ketorolac tromethamine 60 mg did not significantly alter the speed of formation or viscoelastic strength of clots as measured by TEG. These results provide additional support for prior clinical studies confirming the safety of ketorolac administration in the perioperative period.

Effects of three anesthetic induction techniques on heart rate variability.

STUDY OBJECTIVE: To investigate the effects of different clinical induction techniques on heart rate variability (HRV). DESIGN: Two studies are reported. Study 1 prospectively compared the effects of two induction techniques (etomidate vs. thiopental sodium) known to have widely disparate effects on cardiovascular reflexes. Study 2 specifically investigated whether the vagotonic effects of sufentanil cause an increase in vagally mediated HRV. SETTING: Elective surgery in a university-affiliated hospital. PATIENTS: Study 1: 18 ASA physical status I patients having minor surgery; Study 2: 10 ASA physical status III and IV patients having cardiac surgery. INTERVENTIONS: In Study 1, anesthesia was induced with either etomidate 0.3 mg/kg or thiopental sodium 4 mg/kg with 60% nitrous oxide in oxygen. In Study 2, anesthesia was induced with a sufentanil infusion (total dose 2.9 +/- 0.2 micrograms/kg). MEASUREMENTS AND MAIN RESULTS: The electrocardiogram-derived heart rate signal was subjected to power spectral analysis (similar to electroencephalographic analysis) to obtain measurements of (1) absolute HRV power [units of (beats per minute)2] within defined frequency ranges (HRVLO = power between 0 and 0.125 Hz; HRVHI = power between 0.126 and 0.5 Hz; HRVTOT = HRVLO + HRVHI) and (2) normalized HRV power (the percentage of total power) within these same frequency ranges [e.g., %HRVHI = (HRVHI/HRVTOT) x 100%]. In Study 1, both techniques caused large reductions in HRVTOT. The reduction caused by the thiopental sodium technique (-89% +/- 2%) significantly exceeded that caused by the etomidate technique (-58% +/- 13%, p less than 0.02). In Study 2, sufentanil decreased absolute power measurements of vagally mediated HRV (-69 +/- 12 change in HRVHI) but increased corresponding normalized measurements of vagally mediated HRV (90% +/- 30% increase in %HRVHI). CONCLUSIONS: In Study 1, the greater reduction in HRV with the thiopental sodium technique provides evidence that the depressant effects of anesthetics on HRV are related in part to their effects on cardiovascular reflexes. However, the significant depression in HRV caused by the etomidate technique suggests that mechanisms other than baroreflex depression (e.g., impaired consciousness) also are important in these depressant effects. In Study 2, the decrease in HRVHI caused by sufentanil documents that absolute power measurements of vagally mediated HRV are not correlated with changes in parasympathetic tone during a potent opioid induction. This lack of a correlation may result from the decrease in total HRV observed with loss of consciousness. The increase in %HRVHI suggests that normalized measurements of HRV may still provide an index of changes in sympathetic-parasympathetic balance, even when total HRV is decreased following anesthetic administration.