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Biomedical subjects

D J Anderson

Publications and source records attributed to D J Anderson.

At least 505 records · Page 28Linked to original sources
PubMedDate not supplied

Predictors of serious suicide attempts among patients with panic disorder.

Of 74 panic disorder subjects followed up after 7 years, five reported serious suicide attempts and three had completed suicide. Compared with subjects who had not made serious attempts, the serious suicide attempters (including the three suicides) were younger, and fewer of them were married. Also, the serious attempt group had an earlier, more gradual onset of illness. More of the serious attempters had personality disorders and coexisting major depression. At the time of original assessment, the serious attempters had more severe symptoms. These data suggest that among patients with panic disorder, serious suicidal behavior is associated with more severe psychopathology.

Adult↗
PubMedDate not supplied

A computer program for linear nonparametric and parametric identification of biological data.

A computer program package for parametric ad nonparametric linear system identification of both static and dynamic biological data, written for an LSI-11 minicomputer with 28 K of memory, is described. The program has 11 possible commands including an instructional help command. A user can perform nonparametric spectral analysis and estimation of autocorrelation and partial autocorrelation functions of univariate data and estimate nonparametrically the transfer function and possibly an associated noise series of bivariate data. In addition, the commands provide the user the means to derive a parametric autoregressive moving average model for univariate data, to derive a parametric transfer function and noise model for bivariate data, and to perform several model evaluation tests such as pole-zero cancellation, examination of residual whiteness and uncorrelatedness with the input. The program, consisting of a main program and driver subroutine as well as six overlay segments, may be run interactively or automatically.

Computers↗
PubMedDate not supplied

Functional characterization of the novel neuronal nicotinic acetylcholine receptor ligand GTS-21 in vitro and in vivo.

(2.4)-Dimethoxybenzylidene anabaseine dihydrochloride (GTS-21), a compound that interacts with rat neuronal nicotinic acetylcholine receptors (nAChRs), was evaluated using human recombinant nAChRs in vitro and various pharmacokinetic and behavioral models in rodents, dogs and monkeys. GTS-21 bound to human alpha 4 beta 2 nAChR (K1-20 nM) 100-fold more potently than to human alpha 7 nAChR, and was 18- and 2-fold less potent than (-)-nicotine at human alpha 4 beta 2 and alpha 7 nAChR, respectively. Functionally. GTS-21 stimulated [5H]dopamine release from rat striatal slices with an EC50 of 10 +/- 2 microM (250-fold less potent and 70% as efficacious as (-)-nicotine), an effect blocked by the nAChR antagonist dihydro-beta-erythroidine. However, GTS-21 did not stimulate human alpha 4 beta 2 nor human ganglionic nAChRs significantly. In vivo, GTS-21 had no adverse effect on dog blood pressure (< or = 2.5 micromol/kg i.v. bolus infusion), in marked contrast with (-)-nicotine, GTS-21 (-62 micromol/kg.s.e.) also did not cross-discriminate significantly with (-)-nicotine in rats and did not reduce temperature or locomotion in mice. Neither was it active in the elevated plus maze anxiety model (0.19-6.2 micromol/kg.IP) in normal mice. However, GTS-21 did improve learning performance of monkeys in the delayed matching-to-sample task (32-130 nmol/kg.i.m.).

Animals↗
PubMedDate not supplied

Computer-assisted assessment of lateral column movement following plantar fascial release: a cadaveric study.

In patients who fail conservative treatment, releasing the plantar fascia relieves heel pain but destabilizes the lateral column of the foot. After surgery, pain can present in the area of the sinus tarsi, extensor digitorum brevis muscle, between the fourth and fifth metatarsals, and at the calcaneocuboid joint. The precise mechanism and involved structures for this painful compensation remains unclear. The authors hypothesized that the lateral plantar fascial band, bifurcate and cervical ligaments, lateral talocalcaneal ligament, and interosseous talocalcaneal ligament become excessively strained after this surgery. Using eight cadaver lower extremity limbs amputated 7 cm above the ankle joint, structural changes in the foot in response to staged release of the plantar fascia were measured. All ligament, tendon, and osseous structures were exposed along the plantar, medial, and lateral aspects of the foot and ankle. Using a servohydraulic system, compressive loads in increasing increments (50 lbs) were applied along the tibial axis. Tissue and bony structure displacement in the foot was measured using images electronically captured from two fixed cameras and a digital camera following each load change. All measurements were made in pixels and converted to millimeters in a spreadsheet program. Except for plantar fascial measurements, data were expressed as percentage of initial baseline. As expected, increasing compressive loads changed all measurements [repeated measures ANOVA, p<.04]. When releasing the plantar fascia, the inferior sinus tarsi space widened (intact, 85.4+/-10.8%; 1/4 release, 87.7+/-13.0; 1/2 release, 88.3+/-9.2; 3/4 release, 91.2+/-8.8; p<.04). Lateral length increased and medial height decreased, while medial length and lateral height were unchanged as the fascia was sequentially released. Significant movement of the inferior sinus tarsi strained the bifurcate and cervical ligaments, the lateral talocalcaneal ligament, and interosseous talocaneal ligament, which may account for pain following surgery. The initial 1/4 cut of the plantar fascia exerted the greatest mechanical alteration of the foot, suggesting that a partial release may relieve heel pain while optimizing the patient's chances of maintaining structural integrity with 75% of the plantar fascia intact.

Aged↗
PubMedDate not supplied

Complex regional pain syndrome of the lower extremity: a retrospective study of 33 patients.

Even when diagnosed early and treated appropriately, patients with complex regional pain syndrome (CRPS), a condition that can lead to severe painful dysfunction of the limb, may continue to have long-term pain. A retrospective study was conducted of 33 patients with a positive history of CRPS I, CRPS II, or sympathetically maintained pain (SMP) of the lower limb who were treated in either a clinical setting or a pain management center. The average age of individuals diagnosed with CRPS was 43.5 +/- 12.6 (mean +/-SD) years with 60% being female. The most common diagnosis was CRPS I (75.8%) followed by SMP (21.2%), and finally CRPS II (3.0%). The dominant etiology was confirmed as trauma (73%), with the remaining nine cases resulting from elective foot surgery. Fractures were the most common type of injury (45%) and excision of neuroma was the most frequent elective surgical procedure (30%). Time from injury to diagnosis in patients with foot and ankle trauma was 3.9 +/- 3.0 months and from elective surgery to diagnosis was 9.1 +/- 4.0 months (t test, p < .001). Thirteen patients were contacted for long-term follow-up with an average of 3.5 years after initial diagnosis. There was no difference when the pain rating at long-term follow-up was compared to the initial rating (6.2 +/- 1.2 vs. 7.3 +/- 0.6; p = .287), and 11 continue to have more than moderate pain. Thus, many patients with CRPS who seem to be successfully treated, and are discharged from care, still have severe pain years later.

Adolescent↗
PubMedDate not supplied

Using spinal cord stimulation to manage angina pain.

An implanted electrode that delivers low-voltage electrical current to the spinal cord appears to be effective in reducing angina symptoms and improving quality of life in patients who are not candidates for bypass surgery. This article describes the technology and which patients can benefit from it.

Angina Pectoris↗
PubMedDate not supplied

Generation of reactive oxygen species by leukocytes and sperm following exposure to urogenital tract infection.

The association between male urogenital tract infection (UTI) and infertility is still controversial. Oxidative stress caused by reactive oxygen species (ROS) in semen has been suggested to be an important factor in the etiology of poor sperm function through peroxidative damage to the cell membrane. This study explored the potential association between the ROS generation and UTIs by examining ROS production by sperm and seminal leukocytes in response to various infectious and cytokine stimulating factors. Semen and blood samples were obtained from 17 normal donors. Highly motile pure sperm, poorly motile sperm, and polymorphonuclear leukocytes (PMN) were isolated and exposed to various infectious and stimulating factors, including lipopolysaccharide (LPS), gamma interferon (gamma-IFN), tumor necrosis factor-alpha (TNF-alpha), granulocyte, macrophage-colony stimulating factor (GM-CSF), and phorbol myristate acetate (PMA). ROS generation was determined by measuring luminescence in a luminometer. In this study, purified PMNs produced high levels of ROS, and this production was markedly enhanced in the presence of cytokines, LPS, as well as PMA. Pure motile sperm produced low levels of ROS, and ROS production was not enhanced by addition of bacterial products or cytokines. In conclusion, PMNs in semen are the major source of ROS, and ROS production by these cells is enhanced by bacterial products and cytokines. Detection of activation markers and/or soluble factors produced by activated leukocytes in the urogenital tract or semen could enhance the diagnosis and lead to improved therapy of male infertility due to subclinical genital tract infections.

Adult↗
PubMedDate not supplied

Procedural cost accounting: a survival tactic.

With the recent introduction of PPS and DRGs, nonprofit institutions in our industry have had to make major modifications in their methodology for fiscal soundness. One area that must be addressed is cost accounting and, more specifically, procedure cost accounting. Many hospital department managers have no formal training or education in cost accounting. Likewise, very few physicians receive cost-accounting training in their residency programs. Therefore, in the past, there has been little emphasis on this fiscal procedure. Cost accounting is the recording and classifying of the price paid for anything. The costs associated with a specific procedure are assembled into categories and compiled into a base figure with any additional indirect components or overhead costs taken into account. The resulting figure is then corrected for the institution's collection rate to assure complete recovery of all costs. This method is by no means the answer to every organization's needs; however, it is a starting place for managers. Radiology managers can improve upon this worksheet as their knowledge and understanding of the fiscal side of the hospital continues to grow. With more accurate methods for determining costs, managers can incorporate these into the process. The result will contribute to the final goal, a more efficient and cost effective operation.

Accounting↗
PubMedDate not supplied

Treatment of femoral fractures in children by pediatric orthopedists: results of a 1998 survey.

SUMMARY: This study aimed to determine treatment preference of various femoral fracture patterns in children by pediatric orthopedists and whether it is practice dependent. In September 1998, members of the Pediatric Orthopedic Society of North America were surveyed to determine their current preferences in treating each of four middle one-third femoral fracture patterns in four age groups. Forty-four percent (286/656) of those surveyed responded. For each fracture pattern, operative treatment was increasingly preferred over nonoperative as patient age increased, and the preferred treatments within the operative and nonoperative categories changed significantly as patient age increased. Fourteen specific cases of femoral head avascular necrosis were noted after rigid reamed and unreamed rodding. There is a statistically significant trend by pediatric orthopedists to treat older children's femur fractures operatively and younger children's nonoperatively. The consensus treatment is age dependent. The numerous cases of avascular necrosis after rigid rodding are a concern.

Adolescent↗
PubMedDate not supplied

Metabolism and disposition of clarithromycin in man.

The metabolic fate and pharmacokinetics of clarithromycin following a single 250- or 1200-mg oral dose of 14C-clarithromycin were studied in six healthy adult males. Peak plasma levels of clarithromycin averaged 0.6 microgram/ml after the low dose and 2.7 micrograms/ml after the high dose. The AUC of clarithromycin increased 13-fold, with the 4.8-fold increase in dose, while the plasma half-life increased from 4.4 hr to 11.3 hr. The major metabolite in plasma and urine was the microbiologically active 14-hydroxylated-R epimer of clarithromycin. After 5 days, a mean of 38% of the low dose (18% as clarithromycin) and 46% of the high dose (29% as clarithromycin) was recovered in the urine, with approximately one-third eliminated during the first 24 hr. The nature of the urinary and fecal metabolites revealed the involvement of three metabolic pathways, viz. 1) hydroxylation at the 14-position to form the R and S epimers, 2) N-demethylation, and 3) hydrolysis of the cladinose sugar. Secondary metabolism via these pathways was also evident. The overall recovery of metabolites, but not total radioactivity, decreased 42% after the high dose. The nonlinear pharmacokinetic behavior of clarithromycin and the decrease in metabolite production suggest that clarithromycin metabolism can be saturated at high doses.

Adult↗
PubMedDate not supplied

Male genital tract inflammation associated with increased numbers of potential human immunodeficiency virus host cells in semen.

In this study we investigated whether elevated levels of the inflammatory mediator granulocyte elastase in seminal plasma were associated with increased numbers of CD4+ T helper/inducer lymphocytes and monocytes/macrophages in semen, the principal host cells of the human immunodeficiency virus (HIV). Semen samples were obtained from 105 men attending an infertility clinic. CD4+ lymphocytes, monocytes/macrophages and cells expressing the common leukocyte antigen (CD45) were identified by monoclonal antibodies (MAb's) in a biotinstreptavidin immunoperoxidase technique. Granulocyte elastase levels in seminal plasma were determined by an enzyme-linked immunosorbent assay. In 17 men, granulocyte elastase levels were higher than 1000 ng/ml seminal plasma, indicating male genital tract inflammation. Compared to men with low/normal granulocyte elastase levels in semen (less than 250 ng/ml), these men showed significantly higher mean numbers of total leukocytes, CD4+ lymphocytes and monocytes/macrophages in semen (P less than 0.001); median cell numbers for the group with high/inflammatory granulocyte elastase levels were increased 38-fold for total leukocytes (19,800,000 versus 520,625 per ejaculate), 19-fold for monocytes/macrophages (2,594,000 versus 134,565), and 6-fold for CD4+ lymphocytes (82,900 versus 14,100). Because of the increased numbers of potential HIV-host cells in inflammatory semen, male genital tract inflammation may be an important cofactor in the sexual transmission of the human immunodeficiency virus.

Adult↗