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J Adams

Publications and source records attributed to J Adams.

At least 37 records · Page 2Linked to original sources
PubMed1998

Repeated evolution of an acetate-crossfeeding polymorphism in long-term populations of Escherichia coli.

Six out of 12 independent replicate populations of Escherichia coli maintained in long-term glucose-limited continuous culture for up to approximately 1,750 generations evolve polymorphisms maintained by acetate crossfeeding. In all cases, the acetate-crossfeeding phenotype is associated with semiconstitutive overexpression of acetyl CoA synthetase, which allows for the enhanced uptake of low levels of exogenous acetate. Mutations in the 5' regulatory region of the acetyl CoA synthetase locus are responsible for all the acetate crossfeeding phenotypes found. These changes were either transposable-element insertions or a single T-->A nucleotide substitution at position -93 relative to the acs gene translation start site.

Acetate-CoA Ligase↗
PubMed1998

Emerging and reemerging infectious diseases: a multidisciplinary perspective.

Predictions that infectious diseases would be eliminated as a major threat to human health have been shattered by emerging and reemerging infections, among them acquired immunodeficiency syndrome (AIDS), hemorrhagic fevers, marked increases in infections caused by antimicrobial-resistant bacteria, and the resurgence of tuberculosis and malaria. Understanding the dynamics of emerging and reemerging infections is critical to efforts to reduce the morbidity and mortality of such infections, to establish policy related to preparedness for infectious threats, and for decisions on where to use limited resources in the fight against infections. In order to offer a multidisciplinary perspective, 23 infectious disease specialists, epidemiologists, geneticists, microbiologists, and population biologists participated in an open forum at Emory University on emerging and reemerging infectious diseases. As summarized below, the group addressed questions about the definition, the identification, the factors responsible for, and multidisciplinary approaches to emerging and reemerging infections.

Acquired Immunodeficiency Syndrome↗
PubMed1998

Early postoperative calcium levels as predictors of hypocalcemia.

OBJECTIVE: Early, safe postoperative hospital discharge has become a priority in the current environment of cost containment and managed care. One determinant for this following operations of the thyroid or parathyroid glands is a stable postoperative calcium level. This study sought to determine whether early postoperative calcium levels could safely predict hypocalcemia following operations of the thyroid or parathyroid glands. STUDY DESIGN: A retrospective chart review of 197 patients undergoing such operations was undertaken. METHODS: The study population was divided into patients undergoing parathyroid exploration with removal of one or more glands for parathyroid disease ("parathyroid" group) and patients undergoing bilateral thyroid operations ("nonparathyroid" group). Postoperative calcium levels were plotted as a function of time, and the slope between the first two postoperative calcium levels examined. RESULTS: A positive slope predicted normocalcemia in 100% of "nonparathyroid" and 90% of "parathyroid" surgeries. A negative slope was predictive in its magnitude. The nonparathyroid patients who developed postoperative hypocalcemia had an average slope significantly more negative (-0.84% change/h) than patients remaining normocalcemic (-0.49% change/h) (P = .03). Similarly, the parathyroid patients who became hypocalcemic had an average initial slope nearly twice as negative (-1.4% change/h) as patients remaining normocalcemic (-0.78% change/h) (P = .005). CONCLUSIONS: These results indicate that an initial upsloping postoperative calcium curve based on two early postoperative calcium measurements is strongly predictive of a stable postoperative calcium level, and a steeply downsloping initial calcium curve is worrisome for eventual hypocalcemia.

Calcium↗
PubMed1998

Entomoplasma freundtii sp. nov., a new species from a green tiger beetle (Coleoptera: Cicindelidae).

A mollicute (strain BARC 318T) isolated from gut tissue of a green tiger beetle (Coleoptera: Cicindelidae) was found by dark-field microscopy to consist of non-helical, non-motile, pleomorphic coccoid forms of various sizes. In ultrastructural studies, individual cells varied in diameter from 300 to 1200 nm, were surrounded by a cytoplasmic membrane and showed no evidence of cell wall. The organisms were readily filterable through membrane filters with mean pore diameters of 450 and 300 nm, with unusually large numbers of organisms filterable through 200 nm pore membrane filters. Growth occurred over a temperature range of 15-32 degrees C with optimum growth at 30 degrees C. The organism fermented glucose and hydrolysed arginine but did not hydrolyse urea. Strain BARC 318T was insensitive to 500 U penicillin ml-1 and required serum or cholesterol for growth. It was serologically distinct from all currently described sterol-requiring, fermentative Mycoplasma species and from 12 non-sterol-requiring Mesoplasma species, 13 non-sterol-requiring Acholeplasma species and 5 previously described sterol-requiring Entomoplasma species. Strain BARC 318T was shown to have a G + C content of 34 mol% and a genome size of 870 kbp. The 16S rDNA sequence of strain BARC 318T was compared to 16S rDNA sequences of several other Entomoplasma species and to other representative species of the genera Spiroplasma and Mycoplasma, and to other members of the class Mollicutes. These comparisons indicated that strain BARC 318T had close phylogenetic relationships to other Entomoplasma species. On the basis of these findings and other similarities in morphology, growth and temperature requirements and genomic features, the organism was assigned to the genus Entomoplasma. Strain BARC 318T (ATCC 51999T) is designated the type strain of Entomoplasma freundtii sp. nov.

Animals↗
PubMed1998

Professionalism in emergency medicine. SAEM Ethics Committee. Society for Academic Emergency Medicine.

The Society for Academic Emergency Medicine (SAEM), with the support and participation of the American Board of Emergency Medicine (ABEM), the Council of Residency Directors (CORD), the American College of Emergency Physicians (ACEP), the Emergency Medicine Residents Association (EMRA), the American Academy of Emergency Medicine (AAEM), and the Association of Academic Chairs of Emergency Medicine (AACEM), initiated a project entitled Professionalism in Emergency Medicine. Its concepts were developed by the SAEM Ethics Committee, and are intended to describe proper behaviors and attitudes of the successful practitioner of emergency medicine. The behaviors described are not primarily scientific or technical, since those are defined by the core curriculum for residency training and are tested through certification examinations. This document identifies attitudes and behaviors that enhance trust by placing the patient's interest above other interests. This concept serves as the operative definition of professionalism. The purpose of this article is to clarify the professional attitudes and knowledge that are important to the emergency physician (EP). While no physician is likely to meet idealized standards, all EPs must meet basic standards while striving for the ideal. Awareness of these standards must begin early in the socialization process of emergency medical professionals. The standards must be integrated into residency training as well as the clinical practice of all EPs.

Attitude↗
PubMed1998

Association between amputation, arthritis and osteopenia in British male war veterans with major lower limb amputations.

OBJECTIVES: To investigate the association between amputation, osteoarthritis and osteopenia in male war veterans with major lower limb amputations. Specific questions were to determine whether lower limb amputees following trauma are at subsequent risk of developing osteoarthritis (OA) and osteoporosis of the hip on both the amputated and nonamputated sides. DESIGN: Retrospective cohort study in British Male Second World War veterans with major unilateral lower limb amputations. SUBJECTS: Seventy-five male Second World War veterans with major lower limb amputations known to be alive were invited to participate from a subregional rehabilitation centre. After exclusions, 44 agreed to attend for examination and radiological screening. METHODS: The presence of hip OA was determined from a single anterior posterior pelvic X-ray using two approaches: minimum joint space and the Kellgren and Lawrence (K&L) scoring system. Bone mineral density (BMD) was measured by a dual energy X-ray absorptiometry (DXA) scan and prosthetic rehabilitation outcome measures were recorded. RESULTS: Twenty-seven (61%) hips on the amputated side and 10 (23%) on the nonamputated side were positive for OA (based on Kellgren and Lawrence grade of >2). Using a minimum joint space threshold of below 2.5 mm, 24 (55%) hips on the amputation side and 8 (18%) on the nonamputated side were also positive for OA. There was a threefold increased risk of OA for those with above-knee compared to a below-knee amputation. By contrast, from published general population surveys only 4 (11%) cases of hip OA would have been expected on both the amputated and nonamputated hips. There was a significant decrease in femoral neck BMD in the amputated side (p <0.0001) and significantly lower BMD in above-knee amputees than in below-knee amputees (p = 0.0027) as compared to normal age- and sex-matched population. CONCLUSION: Male war veterans with unilateral major lower limb amputations develop significantly more osteoarthritis of the hip than expected on both ipsi- and contralateral sides. Amputation was also associated with loss of bone density. Above-knee amputees develop significantly more hip osteoarthritis and osteopenia of greater severity in the amputated side than below-knee amputees.

Aged↗
PubMed1998

Sexual behavior associated with low Verbal IQ in youth who have severe mental illness.

A retrospective chart review was used to examine sexual behavior (hypersexual, exposing, and victimizing) and cognitive impairment in 200 youth who had serious mental illness. Lower IQ was associated with increased sexual acting-out. For more serious victimizing sexual behaviors, only Verbal IQ differences reached statistical significance. Overall, sexual behavior was strongly associated with a history of sexual abuse. Sexual abuse history was significantly associated only with lower Performance IQ. Therefore, the association between low Verbal IQ and sexual victimizing behavior is distinct from the effects of sexual abuse. Results underscore the importance of verbal cognitive abilities, regardless of overall cognitive level, in the etiology and treatment of sexual behaviors, especially among individuals without a history of sexual abuse.

Adolescent↗
PubMed1998

The N-terminal portion of parathyroid hormone-related protein mediates the inhibition of apical Na+/H+ exchange in opossum kidney cells.

Parathyroid hormone (PTH) and PTH-related protein (PTHrP) can activate a common receptor in several different cell types. Both PTH and N-terminal PTHrP peptides have been shown to acutely inhibit the apical Na+/H+ exchanger in the renal proximal tubule. In this study, the ability of various PTHrP fragments to inhibit apical Na+/H+ exchange was investigated. In addition, the signal transduction events associated with PTHrP inhibition of apical Na+/H+ exchange in polarized OK-P cells were characterized. Both PTHrP-(1-34)NH2 and recombinant full-length PTHrP-(1-141) inhibited apical Na+/H+ exchange activity by approximately 50%. These changes occurred in close temporal association with significant (threefold) increases in cellular cAMP accumulation. PTHrP-(1-34)NH2 had no effect on intracellular Ca2+, inositol phosphate production, or protein kinase C activity. PTHrP peptides, including PTHrP-(38-64)NH2, PTHrP-(67-86)NH2, PTHrP-(102-107)NH2, and PTHrP-(107-139)NH2, which lack the PTH-like N terminus, had no effect on the antiporter activity or cAMP accumulation. The results demonstrate that the N-terminal portion of the PTHrP molecule is responsible for inhibition of the apical Na+/H+ antiporter in OK-P cells.

Animals↗
PubMed1998

Pharmacological effects of SB 220025, a selective inhibitor of P38 mitogen-activated protein kinase, in angiogenesis and chronic inflammatory disease models.

Chronic inflammatory diseases often are accompanied by intense angiogenesis, supporting the destructive proliferation of inflammatory tissues. A model of inflammatory angiogenesis is the murine air pouch granuloma, which has a hyperangiogenic component. In this model, we explored the regulation of inflammatory angiogenesis using SB 220025, a specific inhibitor of human p38 mitogen-activated protein (MAP) kinase, with an IC50 value of 60 nM and 50- to 1000-fold selectivity vs. other kinases tested. In vivo, this compound reduced the lipopolysaccharide-induced production of tumor necrosis factor at an ED50 value of 7.5 mg/kg. In the inflammatory angiogenesis model, over the course of granuloma development, we observed elevated levels of interleukin-1beta and tumor necrosis factor-alpha during the chronic inflammatory phase when intense angiogenesis occurs. SB 220025 at 30 mg/kg b.i.d. p.o. was able to greatly reduce the expression of these cytokines and inhibit angiogenesis by approximately 40%. To further study the effects of p38/CSBP MAP kinase inhibition in angiogenesis-dependent chronic inflammatory disease, SB 220025 was tested in murine collagen-induced arthritis. In this model, SB 220025 was able to prevent the progression of established arthritis. Thus, this p38/CSBP MAP kinase inhibitor, which can reduce inflammatory cytokine production and inhibit angiogenesis, is an effective treatment for chronic proliferative inflammatory disease.

Animals↗
PubMed1998

Pitfalls in industrial drug screening.

Physicians need to establish a protocol for drug testing. Drug testing is, by its nature, often adversarial. Despite the confusing lack of standardized methods for handling positive and negative industrial drug tests, both pre-employment and random, physicians must be methodical in adhering to basic principles of privacy and careful in the interpretation of positive results. Errors in handling drug testing have and will continue to lead to avoidable lawsuits.

Employment↗
PubMed1998

Signals that regulate the host response to Mycobacterium tuberculosis.

An appropriate T helper (Th) 1 immune response is required for the elimination of Mycobacterium tuberculosis. The factors regulating the polarization of mouse or human T cells to produce Th1 or Th2 cytokines are briefly reviewed. These factors include host genetics, cytokines present at the site of T cell activation, the type, dose and localization of antigen, the type of antigen-presenting cells, the engagement of different costimulatory molecules, steroid hormones and age. T cells of children produce low levels of gamma-interferon and we hypothesize that this may partly explain the differences in the clinical manifestations of tuberculosis in children and adults. Given that Th2 cytokines inhibit Th1 responses, the question arises of whether individuals mounting prominent Th2 responses, manifested by high serum IgE levels, are more susceptible to M. tuberculosis. In a community with a high incidence of tuberculosis, serum IgF levels, a marker of prominent Th2 responses, correlate with disease incidence and with socioeconomic deprivation. We propose that Th2 immune dominance, probably induced by intestinal parasites, enhances susceptibility to tuberculosis. Furthermore, our finding that serum IgE declines in patients following active tuberculosis argues that tuberculosis down-regulates Th2 responses.

Age Factors↗
PubMed1997

Neuropsychological function in adults after high dose fractionated radiation therapy of skull base tumors.

PURPOSE: To evaluate the long term effects of high dose fractionated radiation therapy on brain functioning prospectively in adults without primary brain tumors. METHODS AND MATERIALS: Seventeen patients with histologically confirmed chordomas and low grade chondrosarcomas of the skull base were evaluated with neuropsychological measures of intelligence, language, memory, attention, motor function and mood following surgical resection/biopsy of the tumor prior to irradiation, and then at about 6 months, 2 years and 4 years following completion of treatment. None received chemotherapy. RESULTS: In the patients without tumor recurrence or radiation necrosis, there were no indications of adverse effects on cognitive functioning in the post-acute through the late stages after brain irradiation. Even in patients who received doses of radiation up to 66 Cobalt Gy equivalent through nondiseased (temporal lobe) brain tissue, memory and cognitive functioning remained stable for up to 5 years after treatment. A mild decline in psychomotor speed was seen in more than half of the patients, and motor slowing was related to higher radiation doses in midline and temporal lobe brain structures. CONCLUSION: Results suggest that in adults, tolerance for focused radiation is relatively high in cortical brain structures.

Adult↗
PubMed1997

The learning curve for laparoscopic colorectal surgery. Preliminary results from a prospective analysis of 1194 laparoscopic-assisted colectomies.

BACKGROUND: Laparoscopic-assisted colectomy is an emerging technology for patients with cancer, polyps, inflammation, and other types of pathologic conditions. While previous studies have shown better outcomes for laparoscopic cholecystectomies when surgeons perform more procedures, there is no information on the relationship between surgeon volume and outcomes for laparoscopic-assisted colectomy. OBJECTIVE: To evaluate whether better clinical outcomes are found for surgeons who perform higher numbers of laparoscopic-assisted colectomies and whether such a relationship, if it exists, applies to both intraoperative and postoperative outcomes. DESIGN: Analysis of a data set of 1194 patients, operated on by 114 surgeons, from a prospective registry sponsored by the American Society of Colon and Rectal Surgeons, from May 1991 to October 1994. MAIN OUTCOME MEASURES: Completion rate, intraoperative and postoperative complications, and length of hospital stay. RESULTS: In 75% of cases, surgery was completed laparoscopically, with no difference between high-volume surgeons (> or = 40 cases) and low-volume surgeons. Length of stay (average, 6 days) did not vary according to surgeon volume. Postoperative complications occurred in 15% of cases, with a significantly lower rate for high-volume surgeons (10% vs 19%; P < .001). Intraoperative complications occurred in 5% of cases, with a nonsignificant trend toward a lower rate for high-volume surgeons (3.7% vs 6.3%). A multivariate regression analysis, adjusting for type of disease (cancer vs inflammation vs polyps) and for level of difficulty of the procedure (high vs low) showed that for high-volume surgeons there is a lower probability of both intraoperative complications (adjusted odds ratio, 0.56; 95% confidence interval, 0.32-0.97; P = .04) and postoperative complications (adjusted odds ratio, 0.48; 95% confidence interval, 0.34-0.68; P < .001). CONCLUSIONS: There is a learning curve for laparoscopic-assisted colectomy with respect to intraoperative and postoperative outcomes. As with other laparoscopic procedures, surgeons who perform higher volumes of laparoscopic-assisted colectomy have lower rates of intraoperative and postoperative complications.

Colectomy↗
PubMed1997

Population-based geographic variations in DXA bone density in Europe: the EVOS Study. European Vertebral Osteoporosis.

The purpose of this study was to investigate variations in bone density between 16 European populations, 13 of which were participants in the European Vertebral Osteoporosis Study (EVOS). Men and women aged 50-80 years were recruited randomly from local population registers, stratified in 5-year age bands. The other three centres recruited similarly. Random samples of 20-100% of EVOS subjects were invited for dual-energy X-ray absorptiometry (DXA) densitometry of the lumbar spine and/or proximal femur using Hologic, Lunar or Norland pencil beam machines or, in one centre, a Sopha fan-beam machine. Cross-calibration of the different machines was undertaken using the European Spine Phantom prototype (ESPp). Highly significant differences in mean bone density were demonstrated between centres, giving rise to between centre SDs in bone density that were about a quarter of a population SD. These differences persisted when centres using Hologic machines and centres using Lunar machines were considered separately. The centres were ranked differently according to whether male or female subjects were being considered and according to site of measurement (L2-4, femoral neck or femoral trochanter). As expected, bone mineral density (BMD) had a curvilinear relationship with age, and apparent rates of decrease slowed as age advanced past 50 years in both sexes. In the spine, not only did male BMD usually appear to increase with age, but there was a highly significant difference between centres in the age effect in both sexes, suggesting a variability in the impact of osteoarthritis between centres. Weight was consistently positively associated with BMD, but the effects of height and armspan were less consistent. Logarithmic transformation was needed to normalize the regressions of BMD on the independent variates, and after transformation, all sites except the femoral neck in females showed significant increases in SD with age. Interestingly, the effect of increasing weight was to decrease dispersion in proximal femur measurements in both sexes, further accentuating the tendency in women for low body mass index to be associated with osteoporosis as defined by densitometry. It is concluded that there are major differences between BMD values in European population samples which, with variations in anthropometric variables, have the potential to contribute substantially to variations in rates of osteoporotic fracture risk in Europe.

Absorptiometry, Photon↗
PubMed1997

A randomized trial of office-based screening for common problems in older persons.

PURPOSE: To test the effectiveness of a 10-minute office-staff administered screen to evaluate malnutrition/weight loss, visual impairment, hearing loss, cognitive impairment, urinary incontinence, depression, physical limitations, and reduced leg mobility among older persons seen in office practice. This screen was coupled with clinical summaries to assist the physician in further evaluating and managing the screen-included problems. PATIENTS AND METHODS: Twenty-six community-based office practices of internists and family physicians in Los Angeles were randomized to intervention or control groups. Two hundred and sixty-one patients aged > or = 70 years and seeing these physicians for a new visit or a physical examination participated in the study. At the enrollment visit intervention group patients were administered the screening measure and their physicians were given the pertinent clinical summaries. Outcome measures were detection of, and intervention for conditions screened, and health status 6 months after the intervention. RESULTS: Hearing loss was both more commonly detected (40% intervention versus 28% control) and further evaluated (29% versus 16%) by physicians in the intervention group (P < 0.05). No other differences in the frequency of problem detection or intervention were noted between groups. Six months after the intervention no differences were noted in health status between groups. CONCLUSIONS: A brief measure to screen for common conditions in older persons was associated with more frequent detection and follow-up assessment of hearing loss. Although the measure was well accepted by physicians and their staffs, it did not appear to affect detection and intervention in regard to the other screen-included conditions, or health status at 6 months.

Activities of Daily Living↗
PubMed1997

A validational study of the Structured Interview of Symptoms Associated with Sexual Abuse (SASA) using three samples of sexually abused, allegedly abused, and nonabused boys.

OBJECTIVE: With the rapid rise of sexual abuse allegations, there is a growing need to develop instruments to help clinicians determine the likelihood that sexual abuse has occurred. METHOD: This study evaluated the discriminant validity of a structured parent interview regarding emotional, behavioral, and physical symptoms by comparing results among three subsamples of age matched boys: 22 sexually abused boys whose perpetrator confessed, 47 boys evaluated in a sexual abuse clinic but without a history of perpetrator confession and 52 nonabused boys selected after rigorous screening. RESULTS: In comparison with the nonabused (NA) boys, the sexually abused boys were significantly more likely to demonstrate sudden emotional and behavioral changes, frequent stomach aches, more knowledge about sex and sexual activities than expected for age, unusual aggressiveness toward playmate or toy's private parts, crying easily, difficulty getting to sleep, and a change to poor school performance. The internal reliability of the SASA was determined to be .83 and scoring of an abbreviated 12-item scale demonstrated a sensitivity of 90.9% and a specificity of 88.5%. CONCLUSIONS: The findings suggest that Structured Interview of Symptoms Associated with Sexual Abuse (SASA) is an effective tool which may help in the comprehensive assessment of boys who may have been sexually abused.

Adolescent↗