Search PubMed⌕ Search

Biomedical subjects

J E Anderson

Publications and source records attributed to J E Anderson.

At least 73 records · Page 4Linked to original sources
PubMed1999

Autoerythrocyte sensitization (psychogenic purpura): a case report and review of the literature.

Autoerythrocyte sensitization (psychogenic purpura) is an unusual diagnosis, but one that has a characteristic dermatologic manifestation of painful bruising. A typical case is presented, as well as a review of the literature. Treatment consists of psychiatric therapy, which is most effective when initiated early in the disease, so early diagnosis will not only minimize the cost of the medical evaluation but will also benefit the patient.

Adolescent↗
PubMed1999

Myoid cell density in the thymus is reduced during mdx dystrophy and after muscle crush.

Thymic myoid cells share structural and behavioural features with cells of the skeletal muscle lineage: they express regulatory genes and contractile proteins, and they can form myofibers in culture. Historically, those features suggested that myoid cells could be precursors for muscle repair in addition to the satellite cells in muscle that are typically designated as the only muscle precursors. Muscles of the mutant mdx dystrophic mouse strain have a large demand for precursors, which is greatest at a young age. In the present study, immunostaining for troponin T was used to localize myoid cells. We tested the hypothesis that the myoid cell population changes when there is a demand for muscle precursors and that these changes would be anticipated if myoid cells have a role as myogenic precursors or stem cells in muscle. Chronic demands for muscle precursors in mdx dystrophic mice were accompanied by lower myoid cell density in comparison with density in two normal strains (C57BL10/ScSn and Swiss Webster). Acute demand for precursors was accompanied by a sharp decline in thymic myoid cell density within 2 days after a crush injury to one tibialis anterior muscle in normal but not dystrophic animals. To standardize the developmental age of the thymus, density was determined in all animals at 28 days of age. Given the current interest in nonmuscle sources of myogenic stem cells, these data suggest that changes in the density of thymic myoid cells may accompany acute and chronic demands for muscle precursors. Further experiments are required to determine whether thymic myoid cells are participants in distant muscle cell proliferation, new fiber formation, or the establishment of new stem cells in regenerated muscle.

Animals↗
PubMed1999

Prevalence of gastroesophageal reflux disease in peritoneal dialysis and hemodialysis patients.

The prevalence of gastrointestinal reflux disease (GERD) in hemodialysis (HD) and peritoneal dialysis (PD) patients was assessed at a single center with a self-administered questionnaire previously used in a general population. It defines (GERD as the presence of heartburn or acid regurgitation, or both. Risk factors for GERD and GERD-associated symptoms were also evaluated. In the studied population, 29.7% of patients had frequent GERD (heartburn, acid regurgitation, or both symptoms weekly). Frequent GERD was reported by 44.7% of PD patients versus the 18.9% reported by HD patients and the 19.8% reported by the general population. PD and HD patients had similar GERD severity scores [2.3 +/- 0.7 vs 1.9 +/- 0.8, mean +/- standard deviation (SD)]. PD and HD patients reported atypical GERD symptoms at rates similar to those reported by the general population, but having GERD made some atypical GERD symptoms more likely (p < 0.05, Fisher's exact test). In a logistic model, age < 60 [odds ratio (OR) 5.6, confidence interval (CI) 1.5-21.3], smoking (OR 4.7, CI 1.3-16.9), and body mass index > or = 27 (OR 3.9, CI 1.2-13.0) predicted GERD. Sex, race, diabetes, PD, non steroidal anti-inflammatory drugs (NSAIDs), calcium channel blockers, and coffee and alcohol use did not. GERD is more common in PD patients than in HD patients or in the general population. It is not clear whether PD per se is a risk factor for GERD.

Age Factors↗
PubMed1998

Unrelated and HLA-nonidentical related donor marrow transplantation for thalassemia and leukemia. A combined report from the Seattle Marrow Transplant Team and the International Bone Marrow Transplant Registry.

Allogeneic marrow transplantation is curative therapy for thalassemia, but fewer than 30% of patients have an HLA-identical sibling marrow donor. Selection of alternative donors of hematopoietic stem cells (unrelated individuals or HLA-nonidentical family members) has been aided by establishment of world-wide donor registries now exceeding 3.6 million volunteers and by DNA-based HLA typing to more closely match potential donors. Coupled with improved methods to control graft-versus-host disease and prevent fungal and cytomegalovirus infection, remarkable progress has been made in alternative donor transplantation. For patients 50 years of age or younger, with recently diagnosed chronic myelogenous leukemia (CML) in chronic phase, 1- and 5-year survivals after HLA-A, B, DRB1 identical unrelated marrow transplantation in Seattle are 82% and 74%, respectively. These results are essentially identical to outcome in similar patients given HLA-matched sibling allografts. However, the world-wide number of alternative donor transplants for thalassemia remains limited to date: 4 unrelated and 60 HLA-nonidentical related transplants have been reported to the IBMTR since 1969 with actuarial overall survival of 75%. Using the paradigm of CML, it is likely that access to curative therapy of thalassemia will improve with optimal HLA typing and donor selection early in the course of disease.

Bone Marrow Transplantation↗
PubMed1998

HGF/SF is present in normal adult skeletal muscle and is capable of activating satellite cells.

We have shown that hepatocyte growth factor/scatter factor can stimulate activation and early division of adult satellite cells in culture, and that the action of hepatocyte growth factor/scatter factor is similar to the action of the unidentified satellite cell activator found in extracts of crushed muscle. We now provide new evidence that hepatocyte growth factor/scatter factor is present in uninjured adult rat skeletal muscle and that the activating factor in crushed muscle extract is hepatocyte growth factor/scatter factor. Immunoblots of crushed muscle extract demonstrate the presence of hepatocyte growth factor/scatter factor. Furthermore, crushed muscle extract stimulates the scattering of cultured MDCK cells. Immunolocalization studies with adult rat skeletal muscle show the presence of hepatocyte growth factor/scatter factor in the extracellular matrix surrounding muscle fibers; in addition, the receptor for hepatocyte growth factor/scatter factor, c-met, is localized to putative satellite cells. In muscle from mdx mice, hepatocyte growth factor/scatter factor and c-met are colocalized in activated satellite cells in regions of muscle repair. Moreover, the satellite cell-activating activity of crushed muscle extract is abolished by preincubation with anti-hepatocyte growth factor antibodies. Finally, direct injection of hepatocyte growth factor/scatter factor into uninjured tibialis anterior muscle of 12-month-old rats stimulated satellite cell activation. These experiments demonstrate that hepatocyte growth factor/scatter factor is present in muscle, can be released upon injury, and has the ability to activate quiescent satellite cells in vivo.

Animals↗
PubMed1998

Regeneration and myogenic cell proliferation correlate with taurine levels in dystrophin- and MyoD-deficient muscles.

This study coupled proton magnetic resonance spectroscopy (1H-NMR) and in situ hybridization plus autoradiography in a novel examination of different phenotypes of adult myogenesis that arise from genetic disruptions in mice. Study of muscle extracts from normal and dystrophin-deficient mdx limb and diaphragm muscles confirmed our previous findings linking taurine and muscle regeneration at the peak of damage and repair. 1H-NMR distinguished biochemical differences in regenerating muscles that were consistent with the extent of repair in three strains: mdx dystrophic mice; MyoD(-/-) mice that lack expression of the early myogenic regulatory gene MyoD; and a double-mutant mdx:MyoD(-/-) strain lacking expression of both MyoD and dystrophin. We tested the hypothesis that differences in spectra according to genotype and the regeneration phenotype are related specifically to proliferation by committed myogenic precursor cells. 1H-NMR distinguished the three mutant strains: Taurine was highest in mdx muscles, with the phenotype of most effective regeneration; lowest in MyoD(-/-) muscles, with the least effective formation of new muscle in repair, as reported previously; and intermediate in double-mutant muscles, now reported to show an intermediate repair phenotype. The early and late muscle precursors (mpcs) expressing myf5 and myogenin were examined for proliferation. Eighteen percent of mdx myf5-positive mpcs were proliferative, whereas myf5-positive mpcs did not proliferate in regenerating muscles that lacked MyoD expression. By contrast, whereas 30% of myogenin-positive mpcs were proliferative in mdx muscles, almost none were proliferative in MyoD(-/-) muscles, and 12% were proliferative in double-mutant muscles. Therefore, the extent of accumulated structural regeneration, taurine levels, and proliferation of late mpc (expressing myogenin) were congruent across genotypes. Proliferation by early mpc (expressing myf5) was inhibited by the lack of MyoD expression during muscle regeneration. These studies indicate the potential for 1H-NMR monitoring of muscle status in disease, regeneration, and treatment.

Animals↗
PubMed1998

Dystrophy and myogenesis in mdx diaphragm muscle.

In order to determine why the diaphragm is more severely affected by progressive dystrophy than limb muscles in the mdx mouse, we examined how regional variations in diaphragm dystrophy, the measures of disease and repair, proliferation by committed myogenic cells, and the expression of mitogenic basic fibroblast growth factor (bFGF) could contribute to muscle-specific disease phenotypes. There were regional variations in new myotube formation in the diaphragm, with disease more severe in crural than costal leaflets. New repair increased in hyperthyroidism without changes in accumulated repair, probably due to fiber loss. General proliferation was nearly twofold higher in limb than diaphragm mononuclear cells. Since only 2.5-8.4% of committed muscle precursors were proliferating, the higher proliferation by myf5+ myogenic cells in diaphragm did not account for muscle-specific differences. Proliferation by bFGF+ mononuclear cells and an immunogold labeling index for bFGF protein in diaphragm myoblasts were lower in diaphragm than limb muscle. In culture, mixed limb myoblast and fibroblasts contained more S phase cells than diaphragm cells, although myoblasts cycled similarly between muscles. Therefore while muscle architecture and the formation and number of new myotubes certainly affect disease phenotype, the differential outcome of regeneration in mdx diaphragm and limb muscle appears to be contributed by both nonmyogenic and myogenic cells.

Animals↗
PubMed1998

Nuclear magnetic resonance spectroscopy study of muscle growth, mdx dystrophy and glucocorticoid treatments: correlation with repair.

Proton nuclear magnetic resonance spectroscopy (1H NMR) can be used to study skeletal muscle metabolism. The mdx mouse is a unique animal for studies of muscle regeneration, and models the disease of Duchenne muscular dystrophy (DMD). The goals of this study were to determine the potential of 1H NMR spectroscopy as an alternative to conventional histology in monitoring: (1) normal growth in control muscle and the progression of dystrophy in mdx muscle, and (2) beneficial treatments (glucocorticoids) on mdx dystrophy. Ex vivo 1H NMR spectra of limb and diaphragm muscles were obtained from different ages of control and mdx mice, and from mice which were treated with prednisone or deflazacort. Peaks with contributions from creatine, taurine and lipids were examined. Lower levels of taurine and creatine characterized predystrophy and active dystrophy intervals in mdx muscle compared to control. Levels of taurine increased with stabilization of the disease by repair. A measure of accumulated muscle repair, fiber centronucleation and many spectral peaks were highly and significantly correlated. Greater amounts of lipids were found in the diaphragm compared to limb spectra. Treatment of dystrophy, which improved muscle phenotype, resulted in greater levels of taurine and creatine, especially in the limb muscle. Therefore, 1H NMR differentially discriminates: (1) control and mdx muscle; (2) the progression of mdx dystrophy and developmental stages in normal growth; (3) mild and severe dystrophic phenotypes (diaphragm vs limb); and (4) changes associated with improved muscle phenotype and regeneration (due to treatment or injury). The results focus on monitoring muscle repair, not degeneration. We conclude that 1H NMR is a reliable tool in the objective investigation of muscle repair status during muscular dystrophy.

Animals↗
PubMed1998

Anomalous origin of the right coronary artery from the main pulmonary artery: diagnosis and management.

Anomalous origin of the right coronary artery (ARCA) from the main pulmonary artery (MPA) is a rare congenital anomaly, with only 18 reported cases in the pediatric age group. More than half of these had associated cardiac anomalies that masked the presence of ARCA. Conversely, in many patients with ARCA as an isolated anomaly, the diagnosis has been missed during lifetime. The only patient with an isolated ARCA who was diagnosed in infancy presented with congestive heart failure. Asymptomatic infants with ARCA from the MPA have not been previously reported. Three additional cases, two infants and a child with ARCA from the MPA, are reported in this paper. The diagnostic dilemmas and the prognosis are discussed and management is recommended.

Child, Preschool↗
PubMed1998

The effect of age and testosterone on the expression of glial fibrillary acidic protein in the rat cerebellum.

Testosterone reversed the age-related increase in glial fibrillary acidic protein (GFAP) in the male rat cerebellum, a brain region not generally associated with gonadal steroid hormone sensitivity. This supports the hypothesis that a decrease in circulating testosterone contributes to age-related increase in GFAP. These data also suggest that reductions in circulating gonadal steroids during aging could render the brain more susceptible to neurodegeneration and that hormone replacement therapy might have value in neurodegenerative disease intervention.

Aging↗
PubMed1998

A role for tumour necrosis factor-alpha, Fas and Fas-Ligand in marrow failure associated with myelodysplastic syndrome.

Apoptosis of haemopoietic cells in the marrow of patients with myelodysplastic syndrome (MDS) has been suggested as a mechanism for peripheral cytopenias. We determined the expression of Fas (CD95), Fas-Ligand (Fas-L) and TNF-alpha factors known to be involved in apoptosis, in the marrow of 44 patients with MDS and characterized their functional relevance in in vitro assays of haemopoiesis. Multidimensional flow cytometry revealed phenotypically aberrant blasts as defined by orthogonal light scatter and CD45 expression in the marrow of 24/44 patients. Among those blasts Fas expression was increased on CD34-positive cells and on cells co-expressing HLA-DR. In addition, Fas-L was expressed on some CD34+ cells of MDS patients but was never detected on CD34+ cells in normal marrow. Fas and Fas-L mRNAs as well as mRNA for TNF-alpha, known to increase Fas expression in normal marrow, were up-regulated in patients with MDS. TNF-alpha protein and sTNF-R1 levels in marrow plasma were higher in MDS patients than in controls (P<0.002 and <0.003, respectively). However, results were dependent upon disease category: TNF-alpha levels were significantly higher in patients with refractory anaemia (RA) than in patients with RA with excess blasts (RAEB) or RAEB in transformation (RAEB-T) (P=0.043). Conversely, the proportion of Fas-L-positive cells was lowest in patients with RA (P=0.037). In marrow cultures, Fas-Ig, rhuTNFR:Fc or anti-TNF-alpha antibody, by blocking Fas or TNF mediated signals, respectively, significantly increased the numbers of haemopoietic colonies compared to untreated cells (P<0.001, P<0.003, P<0.001, respectively). These results show significant dysregulation in the expression of TNF-alpha, Fas and Fas-L in the marrow from MDS patients. Altered expression of these molecules appears to be of functional relevance in the dysregulation of haemopoiesis in MDS and may be amenable to therapeutic interventions.

Adolescent↗
PubMed1998

The transferrin receptor expressed by gonococcal strain FA1090 is required for the experimental infection of human male volunteers.

Iron, an essential nutrient for most microorganisms, is sequestered by the host to decrease the concentration of iron available to bacterial pathogens. Neisseria gonorrhoeae, the causative agent of gonorrhoea, can acquire iron by direct interaction with human iron-binding proteins, including the serum glycoprotein, transferrin. Iron internalization from host transferrin requires the expression of a bacterial receptor, which specifically recognizes the human form of transferrin. Two gonococcal transferrin-binding proteins have been implicated in transferrin receptor function, TbpA and TbpB. We constructed a gonococcal transferrin receptor mutant without the introduction of additional antibiotic resistance markers and tested its ability to cause experimental urethritis in human male volunteers. The transferrin receptor mutant was incapable of initiating urethritis, although the same inoculum size of the wild-type parent strain, FA1090, causes urethritis in >90% of inoculated volunteers. To our knowledge, this is the first experimental demonstration that a bacterial iron acquisition system is an essential virulence factor for human infection.

Genes, Bacterial↗
PubMed1998

Medical-resource use for suspected tuberculosis in a New York City hospital.

OBJECTIVE: To compare resource use by diagnostic outcome among hospital admissions during which tuberculosis (TB) was suspected. DESIGN: Retrospective study based on chart review and microbiology laboratory data. SETTING: The department of medicine in a municipal hospital serving central Brooklyn, New York. PARTICIPANTS: We identified all adult admissions in 1993 during which TB was suspected. We assigned each admission to one of four mutually exclusive groups defined by the results of microbiological tests (acid-fast bacilli [AFB] smear and culture): culture-positive and smear-positive (C+S+); culture-positive and smear-negative (C+S-); culture-negative and smear-positive (C-S+); or culture-negative and smear-negative (C-S-). Each admission was divided into two separate periods to which the utilization of medical resources was assigned: the diagnostic and the postdiagnostic periods, which were separated by the date of receipt of the first definitive culture report. RESULTS: Data on 519 admissions (93 C+S+; 57 C+S-; 30 C-S+; and 339 C-S-) were analyzed. Although C+S+ were more likely than other groups to have an admitting diagnosis of TB, approximately one quarter of the admissions without TB (C-S+, C-S-) were admitted with the principal diagnosis of TB. For the four groups, C+S+, C+S-, C-S+, and C-S-, the respective rates of TB isolation and anti-TB treatment, and median lengths of isolation were 98%, 87%, and 34 days; 74%, 74%, and 7 days; 83%, 83%, and 15 days; and 44%, 29%, and 0 days. During the diagnostic period, the rate and length of isolation were similar in the AFB-smear-positive groups (C+S+ and C-S+). We estimated that admissions without culture-proven TB (C-S+ and C-S-) accounted for 3,174 (36%) of the 8,712 days of TB isolation expended and for 65% of the 16,671 days of anti-TB treatment. The vast majority of this resource consumption (2,737 [86%] of 3,174 days of isolation) occurred during the diagnostic period before a definitive culture result was known. CONCLUSIONS: Our results suggest that prolonged diagnostic uncertainty and misclassification of cases due to false-positive and false-negative smears are associated with substantial medical-resource consumption. New diagnostic modalities that reduce the period of diagnostic uncertainty could reduce the utilization of resources later found to be unnecessary.

Adult↗
PubMed1998

New needle and syringe use, and use of needle exchange programmes by street recruited injection drug users in 1993.

BACKGROUND: Needle exchange programmes (NEP) provide injection drug users (IDU) with sterile injection equipment and receive used needles in exchange. In this paper we describe the use of new syringes and NEP by IDU and characteristics associated with using NEP in 1993. METHODS: Street-recruited IDU were interviewed in five US locations: Atlanta, Philadelphia, Chicago, New York City, and Los Angeles (LA) county. RESULTS: Most (75-95%) reported it was easy to get a new syringe and for their last injection, 45-77% used a new syringe and 2-18% used a syringe previously used by another IDU. Use of NEP ranged from 8% to 16% in Chicago, Philadelphia, and LA County. In LA County not having injected 'speedball' in the last 30 days, last injection with a new syringe, and reporting it was very easy to get a new syringe were associated with NEP use. In Philadelphia, NEP use was associated with 'speedball' injection in the last 30 days, and in Chicago, not injecting with 'speedball' and injecting with cocaine were associated with NEP use. CONCLUSIONS: In 1993, most street-recruited IDU in Chicago, Philadelphia, and LA County had not used NEP. Factors associated with NEP use were not consistent across sites. Dispersion of NEP and removal of legal barriers restricting access to sterile syringes may be more important in increasing the use of sterile syringes and NEP than client characteristics.

Adult↗
PubMed1998

Visual hemifield mapping using transcranial magnetic stimulation coregistered with cortical surfaces derived from magnetic resonance images.

The perception of a visual stimulus can be inhibited by occipital transcranial magnetic stimulation. This visual suppression effect has been attributed to disruption in the cortical gray matter of primary visual cortex or in the fiber tracts leading to V1 from the thalamus. However, others have suggested that the visual suppression effect is caused by disruption in secondary visual cortex. Here the authors used a figure-eight coil, which produces a focal magnetic field, and a Quadropulse stimulator to produce visual suppression contralateral to the stimulated hemisphere in five normal volunteer subjects. The authors coregistered the stimulation sites with magnetic resonance images in these same subjects using optical digitization. The stimulation sites were mapped onto the surface of the occipital lobes in three-dimensional reconstructions of the cortical surface to show the distribution of the visual suppression effect. The results were consistent with disruption of secondary visual cortical areas.

Adult↗
PubMed1998

Abuse against women in rural Minnesota.

The purpose of this study was to examine the prevalence of physical, emotional, and sexual abuse in women seeking care in rural medical clinics and WIC supplemental food program sites, as well as to examine demographic and health characteristics related to abuse. This was a descriptive, cross-sectional study using a self-administered, anonymous survey. Data were collected in 8 medical clinics and 17 WIC supplemental food program sites in 9 counties of west-central Minnesota during January and February, 1997. The survey instrument asked brief screening questions on physical, emotional, and sexual abuse as well as demographic and health related questions designed to reflect the rural population and characteristics. The survey results showed that in the prior 12 months, 109 (6.6%) of the respondents reported physical abuse, 347 (21.1%) reported emotional/verbal abuse, and 35 (2.1%) reported sexual abuse. Proportional increases in risk of current abuse relative to married women were 2.1 for single, 2.5 for divorced, and 6.5 for separated women, after adjusting for other important variables. Single women with a recent status change had significantly higher risk of current abuse than women with a recent status change at all other marital status levels in adjusted analyses. Women who reported some form of abuse before age 18, and women reporting abuse as an adult prior to the last 12 months, were significantly more likely to report current abuse in all analyses. Prior abuse as an adult was the single best predictor of current abuse in a final logistic regression model.

Adult↗
PubMed1998

Magnetic resonance imaging of regenerating and dystrophic mouse muscle.

Magnetic resonance imaging allows serial visualization of living muscle. Clinically magnetic resonance imaging would be the first step in selecting a region of interest for assessment of muscle disease state and treatment effects by magnetic resonance spectroscopy. In this study, magnetic resonance imaging was used to follow dystrophy and regeneration in the mdx mouse, a genetic homologue to human Duchenne muscular dystrophy. It was hypothesized that images would distinguish normal control from mdx muscle and that regenerating areas (spontaneous and after an imposed injury) would be evident and evolve over time. T2-weighted images of hind-limb muscles were obtained on anaesthetized mice in a horizontal bore 7.1-T experimental magnet. Magnetic resonance images of mdx muscle appeared heterogeneous in comparison to homogeneous images of control muscle. Foci of high intensity in mdx images corresponded to dystrophic lesions observed in the histologic sections of the same muscles. In addition, it was possible to follow chronologically the extent of injury and repair after an imposed crush injury to mdx muscle. These results should make it possible to obtain meaningful magnetic resonance spectra from particular regions of interest in muscle as viewed in magnetic resonance images (i.e., regenerating, degenerating, normal muscle) acquired during neuromuscular diseases and treatment regimens.

Animals↗