Intracerebroventricular LHRH relieves behavioral deficits due to vomeronasal organ removal

Contact between the sexes in many species is known to produce hormonal changes in the male [increases in serum luteinizing hormone (LH) and/or testosterone] that can be interpreted as due to an intracerebral release of LH-releasing hormone (LHRH). In some circumstances, these hormonal changes appear to depend on an intact vomeronasal sensory system. Exogenous LHRH is also known to facilitate mating behavior in several species. We show here that LHRH delivered into the cerebral ventricles can restore some mating behavior lost when the vomeronasal organs are removed from sexually inexperienced male hamsters. The results are consistent with our working hypothesis that intracerebral LHRH release is an intermediate in the facilitation of mating behavior by vomeronasal sensory input.     

Sampling Patients Within and Across Health Care Providers: Multi-Stage Non-Nested Samples in Health Services Research

In order to better inform study design decisions when sampling patients within and across health care providers we develop a simulation-based approach for designing complex multi-stage samples. The approach explores the tradeoff between competing design goals such as precision of estimates, coverage of the target population and cost.We elicit a number of sensible candidate designs, evaluate these designs with respect to multiple sampling goals, investigate their tradeoffs, and identify the design that is the best compromise among all goals. This approach recognizes that, in the practice of sampling, precision of the estimates is not the only important goal, and that there are tradeoffs with coverage and cost that should be explicitly considered. One can easily add other goals. We construct a sample frame with all phase III clinical cancer treatment trials that are conducted by cooperative oncology groups of the National Cancer Institute from October 1, 1998 through December 31, 1999. Simulation results for our study suggest sampling a different number of trials and institutions than initially considered.Simulations of different study designs can uncover efficiency gains both in terms of improved precision of the estimates and in terms of improved coverage of the target population. Simulations enable us to explore the tradeoffs between competing sampling goals and to quantify these efficiency gains. This is true even for complex designs where the stages are not strictly nested in one another.     

Dose fractionation of radiolabeled antibodies in patients with metastatic colon cancer.

Twelve patients with metastatic colon cancer were treated with 131I-chimeric B72.3 (IgG-4) at total doses of 28 or 36 mCi/m2 in two or three weekly fractions. Bone marrow suppression was the only significant side effect. The degree of bone marrow suppression adjusted for whole-body dose was modestly but statistically significantly (p = 0.04) less than that seen with identical doses given as a single infusion for the total dose of 36 mCi/m2. Nine of twelve patients developed an antibody response to ch B72.3, which altered the kinetics of radiolabeled antibody in four patients given a second course of therapy. One patient had a minor response that lasted 4 mo. Fractionation of this particular radiolabeled antibody at the dose schedule used produced a modest increase in the therapeutic window in regard to administered dose.     

Muscle glycogen and glucose uptake during exercise in humans.

Six men were studied during 40 min of cycling exercise to examine the relationship between leg glucose uptake and muscle glycogen concentration. Exercise resulted in significant increases in leg glucose uptake, while muscle glycogen and arterial blood glucose concentrations declined. Arterial plasma insulin levels did not change significantly. There was a significant inverse relationship between muscle glycogen concentration and glucose uptake during exercise which suggests a possible regulatory influence of muscle glycogen on glucose uptake in the early stages of exercise in humans.     

Family dynamics and emotional expression among patients with chronic pain and depression

Exploration of the relative roles of family dynamics and release of constrained, negative emotion in changing pain and depressive symptoms. Eighteen patients presenting mild to moderate depression and diagnoses of psychogenic pain disorder were randomly assigned to 1 of 2 treatment groups. One group was designed to facilitate the release of constrained and overcontrolled negative affect while the other was designed to provide information about pain and depression. Findings suggest that initial incongruity between patient's and significant other's ratings of family relationships retard changes in pain status and depressive symptoms. No significant differences were noted between patients who were taught to express negative feelings and those who were taught simply to understand those feelings. Results are discussed in terms of theories about family dynamics in the initiation and maintenance of pain conditions and in terms of the role of constrained affect as a precursor to both psychogenic pain and depression.     

Down-Regulation of Estrogen Receptor Immunoreactivity by 17β-estradiol in the Guinea Pig Forebrain

Low amplitude pulses of estradiol-17β (E₂-17β) are more effective than large single bolus injections or constant exposure to E₂-17β in inducing progesterone-facilitated sex behavior in female rats and guinea pigs. The present study examined whether the increased responsiveness to E₂-17β is due to an increase in the number of estrogen receptors in the estrogen receptor rich areas of the hypothalamus and amygdala. Initial studies examined the rapid effects (20 min) of a high dose of E₂-17β (50 μg) on estrogen receptor immunostaining using either the H222 antibody or the ER 21 antiserum. ER 21 immunostaining was not affected by the E₂-17β treatment suggesting that it binds to both occupied and unoccupied estrogen receptors. Therefore the ER 21 antiserum was used to characterize the regulation of estrogen receptor immunoreactivity (ER-IR) by E₂-17β. ER-IR was examined for 48 h and serum E₂-17β for 24 h following a 2 μg s.c. injection of E₂-17β (a dose similar to that used in multiple pulse paradigms). Serum E₂-17β peaked 15 to 30 min following the injection and returned to baseline values by 1 h. In all but one area maximal suppression of ER-IR occurred at 12 h. In summary, 1) decreases in estrogen receptor immunoreactivity following E₂-17β are consistent with studies in which estrogen receptors were assayed by binding assays and estrogen receptor mRNA was determined by in situ hybridization; 2) the ER 21 antiserum is able to detect both occupied and unoccupied estrogen receptors and 3) H222 immunoreactivity is influenced by the presence of E₂-17β, so that the level of H222-IR is a reflection of ligand/receptor binding dynamics. The data suggest that up-regulation of estrogen receptors does not account for the increase in behavioral sensitivity which is observed following multiple pulses of E₂-17β.     

Greenfield filter prophylaxis of pulmonary embolism in patients undergoing surgery for acetabular fracture.

Pulmonary embolism is a potentially lethal complication among patients with acetabular fractures requiring surgery. The reliability, safety, and extent of efficacy of pharmacologic as well as existing nonpharmacologic anticoagulation prophylaxis in this patient group has not been determined. A careful analysis of the myriad factors acting on these patients who have had major trauma and have undergone a major surgical procedure about the hip prompted a change in our approach to prophylaxis in this patient group. In the period from March 1984 through October 1987, 51 patients having 52 acetabular fractures underwent osteosynthesis at the Wake Forest University Medical Center. Twenty-four patients had two or more identifiable risk factors and underwent insertion of a Greenfield filter for prevention of pulmonary emboli. Filters were inserted at the time of acetabular surgery with C-arm guidance via the internal jugular vein approach. The average time for insertion was 57 min. Placements were verified by plain roentgenograms. There were no complications during filter insertion. Four patients with filters (17%) developed leg edema; in three the edema was minor, and in one the filter trapped what could have been a fatal embolus but caused lower extremity venous stasis severe enough to result in peripheral lower extremity tissue loss. There were no pulmonary emboli (by clinical criteria). The remaining 27 patients had routine medical prophylaxis and no filters. In this group, two patients had a clinically evident pulmonary embolus (7%), and one of these patients died. Two other patients (7%) had minor chronic leg edema. In one of them, a proximal deep venous thrombosis in the lower extremity was documented with venography, requiring rehospitalization and anticoagulant therapy.(ABSTRACT TRUNCATED AT 250 WORDS)     

Determinants of enrollment among applicants to PACE.

During the 1970s and 1980s, a new approach to the integration of acute and long-term care (LTC) services was conceived and refined at On Lok, an organization in the Chinese community of San Francisco. Since then, On Lok and 10 Federal demonstration sites have tested this model which is today called the Program of All-Inclusive Care for the Elderly (PACE). This program has gained considerable political support and as a result, the 1997 Balanced Budget Agreement establishes PACE as a permanent provider under Medicare. The Federal demonstration of PACE was designed as a voluntary program. By exploiting its voluntary enrollment design, this study analyzes the determinants of program participation within a group of screened applicants. Findings of this study support the theory that the capitated payment structure of PACE creates incentives for program staff to avoid costly individuals. However, home ownership and provider attachment also act as important and significant barriers to enrollment.