Effects of d-amphetamine on grooming and proximity in stumptail macaques: differential effects on social bonds

An experiment was conducted to determine the effects of d-amphetamine on the expression of certain social behaviors, i.e., grooming and proximity, initiated by adult male stumptail macaques living in a large group comprised of both sexes and all ages. Traditionally, grooming behavior and proximity behavior have been considered indicators of social affinity. Under the non-drug conditions of the present study, the two types of behaviors were initiated in greatly different proportions toward individual members of the group. The acute administration of d-amphetamine (0.01-0.3 mg/kg IM) resulted in marked increases in the rate of self-grooming, i.e., the number of self-grooming bouts initiated per hour, for all subjects and in decreases in the rate at which subjects groomed other monkeys, but the drug appeared to have no effect on the rate at which a subject positioned itself near another monkey (proximity). Consequently, the drug had different effects on the two relationships represented by grooming behavior and proximity behavior. Drug administration also produced changes in the distribution of grooming and proximity initiated by the subjects toward various classes of interactants in the group. Furthermore, the changes were not of the same magnitude for the two behaviors. These data provide additional evidence that different group members receive differential behavioral interactions from drugged subjects.     

Two novel loci,COBL and SLC10A2, for Alzheimer's disease in African Americans

Introduction

African Americans' (AAs) late-onset Alzheimer's disease (LOAD) genetic risk profile is incompletely understood. Including clinical covariates in genetic analyses using informed conditioning might improve study power.

Magnetic resonance imaging in pulmonary arterial hypertension

Magnetic resonance imaging (MRI) was used to examine the right ventricle and pulmonary arteries in 17 patients with pulmonary artery (PA) hypertension documented by cardiac catheterization. The study population consisted of 7 patients with primary pulmonary hypertension, 7 with Eisenmenger's syndrome and 3 with pulmonary hypertension secondary to lung disease. The MRI studies of patients were compared with those of 10 normal volunteers. Multislice gated transaxial images encompassed the right ventricle and central pulmonary arteries, showing the severity of right ventricular (RV) hypertrophy in proportion to the elevation of PA pressure and reversal of septal curvature when PA pressure approximated systemic pressure. End-diastolic RV wall thickness and mean pulmonary pressure correlated well (r = 0.79). MRI showed enlargement of PAs in all patients with PA hypertension. A magnetic resonance signal was present in the PAs throughout the cardiac cycle in patients with severe PA hypertension (more than 90 mm Hg) and was absent during systole in normal subjects. A signal within the PAs in systole is consistent with decreased flow velocity in patients with severe PA hypertension. MRI was useful in detecting each of the congenital anatomic defects in patients with Eisenmenger's syndrome. This study indicates the potential of MRI for evaluating the severity of PA hypertension by providing direct measurements of RV wall thickness and PA diameter and by detecting abnormal intraluminal signal intensity during the cardiac cycle.     

Intraoperative detection of myocardial ischemia in high-risk patients: electrocardiography versus two-dimensional transesophageal echocardiography

Because acute segmental wall motion abnormalities (SWMAs) of the left ventricle are highly sensitive and specific indicators of myocardial ischemia, this study compared the incidence and significance of ischemia, as detected by two-dimensional transesophageal echocardiography and surface electrocardiography, during anesthesia and surgery in patients at high risk of myocardial ischemia. During surgery, 24 of the 50 patients studied had new SWMAs, whereas only six had ST segment changes. All patients with ST segment changes also had new SWMAs: in three instances, SWMAs occurred before the ST segment change, and in three instances, they occurred simultaneously. All three patients who had intraoperative myocardial infarctions also had persistent intraoperative SWMAs, whereas only one patient had ST segment changes. Ten healthy patients requiring noncardiovascular surgery were monitored similarly; none of these had SWMAs, ST segment changes, or myocardial infarction. This study demonstrates the superiority of two-dimensional transesophageal echocardiography over electrocardiography for the intraoperative detection of myocardial ischemia. Furthermore, when new SWMAs persist to the conclusion of surgery, myocardial infarction is likely to have occurred.     

Internal Mammary Nodal Chain Drainage Is a Prognostic Indicator in Axillary Node-Positive Breast Cancer

Background Internal mammary (IM) nodes are a potential site of breast lymphatic drainage. We examined the relationship between lymphoscintigraphic evidence of IM drainage and survival in early-stage breast cancer patients (pts). Methods From a prospective database of 855 consecutive sentinel node mapping procedures using peritumoral radiocolloid injection from 1996–2004, we analyzed the 604 cases with stage I–III breast cancer. Overall survival and recurrence-free survival (OS, RFS) rates were compared in pts with (IM+) and without (IM-) IM drainage on lymphoscintigraphy using Kaplan-Meier plots and Cox proportional hazards models. Results: 100 of 604 pts (17%) showed IM drainage. Five-year OS and RFS were 92% vs 88% and 88% vs 85% in IM- vs IM+ pts. In the 186 pts with axillary metastases (node+), 5-year OS and RFS were 91% vs 71% and 84% vs 69% in IM- vs IM+ pts. Univariate analysis of node+ pts estimated increased mortality risk for IM+ (hazard ratio, HR 2.9, P = .04), ≥4 positive nodes (HR 3.2, P = .02), tumors that were ER-negative (HR 3.4, P = .02), or had high Ki-67 (HR 6.8, P = .01). Multivariate analysis estimated similar increased risks [≥4 nodes (HR 4.0, P = .02), IM+ (HR 3.3, P = .06), and ER negativity (HR 2.6, P = .09)]. Conclusions IM nodal drainage predicted a nearly 3-fold increased mortality risk in node+ pts. Peritumoral radiocolloid injection provides a clinically relevant assessment of IM drainage and should be prospectively tested for its value in tailoring treatment strategies for axillary node-positive pts. Presented at the 29th Annual San Antonio Breast Cancer Symposium, December 14–17, 2006.     

Predictors and prevalence of patients undergoing additional kyphoplasty procedures after an initial kyphoplasty procedure

Background context

Vertebral cement augmentation, including kyphoplasty, has been shown to be a successful treatment for pain relief for vertebral compression fracture (VCF). Patients can sustain additional symptomatic VCFs that may require additional surgical intervention.

Purpose

To examine the prevalence and predictors of patients who sustain additional symptomatic VCFs that were treated with kyphoplasty.

Study design

A retrospective review of patients who previously underwent kyphoplasty for VCFs and had additional VCFs that were treated with kyphoplasty.

Patient sample

A total of 256 patients underwent kyphoplasty for VCFs from 2000 to 2007 at a single medical center.

Outcome measures

The outcome measure of interest was the need for an additional kyphoplasty procedure for a symptomatic VCF.

Methods

Risk factors such as age, sex, smoking status, and steroid use were assessed, as well as bisphosphonate use. Sagittal spinal alignment via Cobb angles for thoracic, thoracolumbar, and lumbar regions was assessed.

Results

About 22.2% of the patients had an additional symptomatic VCF that was treated with a kyphoplasty procedure. Steroid use was the only significant risk factor for predicting patients with additional symptomatic VCFs who underwent additional kyphoplasty. The average time to the second VCF was 33 days. Adjacent-level VCFs were most common in the thoracic and thoracolumbar spine. Bisphosphonate use was not shown to be protective of preventing additional VCFs during this follow-up period.

Conclusion

This is the first single-center review of a large cohort of patients who underwent additional-level kyphoplasty for symptomatic VCFs after an index kyphoplasty procedure. Our results suggest that patients with a VCF who use chronic oral steroids should be carefully monitored for the presence of additional symptomatic VCFs that may need surgical intervention. Patients with prior thoracic VCFs who have additional back pain should be reevaluated for a possible adjacent-level fracture.     

Current theories on the etiology of idiopathic scoliosis

Review of the literature shows that the cause of idiopathic scoliosis remains unknown, although research has possibly eliminated some hypothetical causes. Abnormalities of disc, bone, muscle, and collagen do not appear to be etiological factors but, rather, reflect the effects of scoliosis on normal tissues. Although most patients with idiopathic scoliosis are thought of as tall and slender, it has not yet been proven that growth in this condition differs from normal. It is possible that idiopathic scoliosis is caused by multiple factors rather than a single factor. Perhaps there are different factors for curve initiation and curve progression. It appears that a brain stem or equilibrium abnormality does exist in patients with idiopathic scoliosis, although more research is needed to confirm and define the problem. There also may be a genetic basis for idiopathic scoliosis, as it does seem to occur within patients' families more frequently than in the general population. Whether these two factors form the basis for a multifactorial etiology of idiopathic scoliosis remains to be proven.     

A recalcitrant, erythematous, desquamating disorder associated with toxin-producing staphylococci in patients with AIDS.

Although staphylococcal infections are common in patients with AIDS, staphylococcal toxin-related disorders have rarely been described. Five cases of a staphylococcal toxin-associated syndrome characterized by prolonged erythema, extensive cutaneous desquamation, hypotension, tachycardia, and multiple organ involvement are described in patients with AIDS. These illnesses were recurrent and recalcitrant with a mean duration of 50 days. Toxic shock syndrome toxin-1-producing staphylococci were isolated from three and staphylococcal enterotoxins B and A from one patient each. Sources of organisms were blood, one patient, and soft tissues and nasal accessory sinuses, two patients each. Three of the five patients died of renal failure and central nervous system abnormalities. One survivor required intubation for respiratory failure. All individuals manifested a marked diminution of CD4+ cells. Other laboratory abnormalities included azotemia and prolongation of partial thromboplastin time. Oliguria occurred in three patients. Thus, this recalcitrant erythematous desquamative disorder appears to be a variant of staphylococcal toxic shock syndrome in certain subsets of immunocompromised individuals.