The detection of recombinant hepatitis B surface antigen from "vaccine escape mutants" in two HBsAg immunoassays.
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Hepatitis B Antigens↗
Biomedical subjects
B Peterson
Publications and source records attributed to B Peterson.
Accounts receivable systems: the key to financial health.
Just as medical technology has made quantum leaps during the past few decades, the business side of running and maintaining a medical practice has changed dramatically as well. Gone are the days when physicians could submit bills to insurance companies and expect to receive timely payment. Even longer gone are the days when patients walked into a doctor's office actually prepared to write a check or leave cash for services. Today, the task of billing and collecting is more complex, more time consuming, and more deserving of the attention of a skilled office worker.
Accounts Payable and Receivable↗
Studying interactions of four proteins in the yeast two-hybrid system: structural resemblance of the pVHL/elongin BC/hCUL-2 complex with the ubiquitin ligase complex SKP1/cullin/F-box protein.
The yeast two-hybrid system is a powerful technique that detects interactions between two proteins and has been useful in identifying new binding partners. However, the system fails to detect protein-protein interactions that require the presence of additional components of a multisubunit complex. Here we demonstrate that the vector YIpDCE1 can be used to express elongins B and C in yeast, and that these proteins form a stable complex that interacts with the von Hippel-Lindau tumor-suppressor gene product (pVHL). Only when pVHL and elongins B and C (VBC) are present does an interaction with the cullin family member, hCUL-2, occur, forming the heterotetrameric pVHL/elongin BC/hCUL-2 complex. This system was then used to map the binding region of hCUL-2 for the VBC complex. The first amino-terminal 108 aa of hCUL-2 are necessary for interaction with the VBC complex. The elongin BC dimer acts as a bridge between pVHL and hCUL-2 because pVHL and hCUL-2 can form distinct complexes with elongins B and C. These results reveal a striking structural resemblance of pVHL/elongin BC/hCUL-2 complex with the E3-like ubiquitin ligase complex SKP1/Cullin/F-box protein with respect to protein composition and sites of interactions. Thus, it seems possible that pVHL/elongin BC/hCUL-2 complex will possess ubiquitin ligase activity targeting specific proteins for degradation by the proteasome.
Binding Sites↗
Comparison of Lewy body variant of Alzheimer's disease with pure Alzheimer's disease: Consortium to Establish a Registry for Alzheimer's Disease, Part XIX.
OBJECTIVE: To compare the clinical, neuropsychological, and neuropathologic findings in patients with AD alone with those in patients with the Lewy body variant of AD (LBV). BACKGROUND: Prior studies indicate that patients with LBV not only have distinct clinical and neuropsychological differences from those with AD alone, but have a poorer prognosis with shorter survival time. METHODS: The authors evaluated 74 patients with autopsy-confirmed AD alone and 27 patients with LBV, and compared demographic characteristics and clinical, neuropsychological, and neuropathologic findings. RESULTS: The two groups of patients were equivalent with respect to age at time of entry into the study, years of education, and sex. Two or more extrapyramidal clinical manifestations were found in 44% of patients with LBV, compared with 16% of patients with AD alone (p = 0.02). Duration of survival after entry into the study was similar in both groups, with a mean survival of 3.6 (+/-2.1) years for AD alone versus 3.8 (+/-1.9) years for LBV. Of the various neuropsychological tests administered at the last Consortium to Establish a Registry for Alzheimer's Disease evaluation, only delayed recall of a learned word list was significantly different in the two groups, with 32% of patients with LBV versus 15% of patients with AD alone recalling any items (p = 0.04). Neuropathologic findings confirmed those of previous studies and showed that neurofibrillary tangles were significantly less frequent in the neocortex of patients with LBV than in those with AD alone. CONCLUSION: Compared with patients with AD alone, those with LBV had a greater frequency of extrapyramidal manifestations, somewhat better recall on a selected memory task at their final evaluation, and a significantly lower frequency of neocortical neurofibrillary tangles at autopsy. There were no differences between the two groups, however, in survival time from entry into the study.
Aged↗
Total shoulder and relative muscle strength in the scapular plane.
Strength profiles of the shoulder joint are measured experimentally for two arm positions in "the scapular plane" in order to present quantitative data on the shoulder strength. Apart from yielding the actual force a subject can exert in various directions, these measurements also exhibit e.g. the strongest and weakest directions, in fact the relative strength in all directions. The inter-individual variation of the direction of maximal force was at most 14 degrees (sd). The experimental profiles are compared with the corresponding theoretical profiles, obtained by using a shoulder model. The calculations were made both with default muscle parameters and individually adapted parameters. The results show that the employed shoulder model, which is based on data from an elderly population, may be adapted to other populations and that the necessary changes in relative muscle strength are those expected on biomechanical grounds. Without model changes the difference between measured (in the mean) and predicted maximal force directions was at most 50 degrees. Muscle parameter adjustment reduced this difference to 23 degrees. The strength profiles clearly indicate in what direction a person can produce larger forces and which muscles that contribute.
Adult↗
Management of pediatric liver injuries: a 13-year experience at a pediatric trauma center.
PURPOSE: This study of traumatic liver injuries (LI) in children reviews the authors' management and identifies the indications for surgical intervention. METHODS: A total of 11,761 admissions over 13 years to a regional pediatric trauma center were surveyed. RESULTS: LI were identified in 328 children. Mechanisms included 39% pedestrians struck by a vehicle, 34% motor vehicle occupants, 13% falls or discrete blows to the abdomen, 5% bicycle injuries, 5% child abuse, and 4% penetrating injuries. Eighty-seven of patients with LI were treated nonoperatively with a mortality rate of 17%. Six percent of deaths were attributed to the LI and massive hemorrhage, all of which presented with cardiopulmonary resuscitation (CPR) in progress, with the remainder of deaths attributed to massive head, neck, or chest injuries (HNCI, 90%) and sepsis (4%). Surgery was performed in 13% of all LI and included major hepatic vascular injury (MHVI) repairs (34%), hepatorrhaphies (34%), lobectomies (27%), and biliary repairs (4%). Excluding the nonoperative group deaths, the need for blood transfusion of more than 25 mL/kg in the first 2 hours as an indicator of surgical necessity or a MHVI had, respectively, a sensitivity of 34% and 67%, specificity of 98% and 97%, positive predictive value of 79% and 53%, negative predictive value of 89% and 98%, and prediction accuracy of 88% and 95%. In the surgical management group, the mortality rate was 23% with 40% of deaths attributed to MHVI, 30% a combination of MHVI and HNCI, 20% massive HNCI, and 10% sepsis. CONCLUSIONS: The majority of pediatric LI are not associated with hemodynamic instability and can be successfully managed nonoperatively (72%). Hemodynamic instability, as defined by the need for blood transfusion in excess of 25 mL/kg within the first 2 hours, was a strong indicator of a MHVI, which was often a lethal injury (70%).
Adolescent↗
Clostridium difficile colitis associated with infant botulism: near-fatal case analogous to Hirschsprung's enterocolitis.
We present the first five reported cases of Clostridium difficile-associated diarrhea (CDAD) in children with infant botulism caused by Clostridium botulinum. We compare two fulminant cases of colitis in children with colonic stasis, the first caused by infant botulism and the second caused by Hirschsprung's disease. In both children, colitis was accompanied by hypovolemia, hypotension, profuse ascites, pulmonary effusion, restrictive pulmonary disease, and femoral-caval thrombosis. Laboratory findings included pronounced leukocytosis, hypoalbuminemia, hyponatremia, coagulopathy, and, when examined in the child with infant botulism, detection of C. difficile toxin in ascites. CDAD recurred in both children, even though difficile cytotoxin was undetectable in stool after prolonged initial therapy. Four children who had both infant botulism and milder CDAD also are described. Colonic stasis, whether acquired, as in infant botulism, or congenital, as in Hirschsprung's disease, may contribute to the susceptibility to and the severity of CDAD.
Botulism↗
Pain in nursing home residents: an exploration of prevalence, staff perspectives, and practical aspects of measurement.
OBJECTIVE: To help rectify the underdiagnosis of chronic pain in frail nursing home residents by developing a new feasible pain self-report instrument, the structured pain interview; to use this new tool to estimate pain prevalence and staff's knowledge of residents' pain in two nursing homes; and to compare the performance differences of the structured pain interview and the commonly used 0-10 scale. DESIGN: Cross-sectional survey. SETTING: One 120-bed VA-affiliated and one 125-bed university-affiliated, community-based nursing home in Durham, North Carolina. PATIENTS: One hundred fifty-eight chronic care nursing home residents without aphasia, acute illness, persistent vegetative status, or severe hearing impairment and 3 1 nursing home nurses. OUTCOME MEASURES: Pain prevalence according to resident self-report and nurse report; stability of response to the structured pain interview and 0-10 scale over 1 month; agreement between residents and nurses on the structured pain interview and 0-10 scale. RESULTS: Fifty-eight percent of the VA and 45% of the community nursing home residents reported pain. Forty-two percent at the VA and 20% at the community home were unable to respond to the 0-10 scale, compared with 7.5% and 14% using the structured pain interview. Stability of response to the structured pain interview at 1 month was 0.56 at the VA (nurse-resident agreement 0.38) and 0.72 in the community (nurse-resident agreement 0.07), which was very comparable to the 0-10 scale. CONCLUSIONS: We have developed a highly feasible tool for examining pain prevalence in nursing homes. This tool uncovered considerable miscommunication regarding pain between residents and staff. Improvement in pain communication between nursing home residents and staff is needed, so that more effective pain treatment programs can be developed for this vulnerable population.
Attitude of Health Personnel↗
Complications of axillary lymph node dissection for carcinoma of the breast: a report based on a patient survey.
BACKGROUND: Axillary lymph node dissection is commonly performed as part of the primary management of breast carcinoma. Its value in patient management, however, has recently been questioned. Few studies exist that document long term complications. METHODS: Four hundred thirty-two patients with Stage I or II breast carcinoma who were free of recurrence 2-5 years after surgery were identified. A cross-sectional survey was conducted to determine the prevalence of long term symptoms and complications as perceived by the patient, and patient and treatment factors that may have predicted complications were determined. Three hundred thirty of the 432 (76%) completed a mailed, self-administered questionnaire. In addition, the medical records of the 330 patients were reviewed. Patient and treatment factors were analyzed with logistic regression. RESULTS: Numbness was reported by 35% of patients at the time of the survey. Pain was noted in 30%, arm swelling in 15%, and limitation of arm movement in 8%. Eight percent reported episodes of infection or inflammation at some point since the diagnosis of breast carcinoma. The majority of symptoms were mild and interfered minimally with daily activities. Younger age (P=0.001) was associated with more frequent reporting of pain. Numbness was more common in younger patients (P=0.004) as well as in those with a history of smoking (P=0.012). There was a positive association of limitation of arm motion with adjuvant tamoxifen therapy (P=0.016). Arm swelling was associated with both younger age (P=0.004) and greater body surface area (P=0.008). Radiation therapy was associated with a higher frequency of infection or inflammation in the arm and/or breast (P=0.001). CONCLUSIONS: Mild symptoms, especially pain and numbness, are common 2-5 years after axillary lymph node dissection. The frequency of inflammation or infection in patients treated with radiation to the breast or chest wall after an axillary lymph node dissection may be greater than previously appreciated. Severe complications or symptoms that have a major impact on daily activities are uncommon. These findings should help health care providers and their patients with breast carcinoma weigh the pros and cons of axillary lymph node dissection.
Activities of Daily Living↗
Augmented therapy of extensive Hodgkin's disease: radiation to known disease or prolongation of induction chemotherapy did not improve survival--results of a Cancer and Leukemia Group B study.
PURPOSE: This prospective randomized trial in extensive untreated Hodgkin's disease was undertaken to assess the potential benefit of augmented therapy (12 months chemotherapy or radiation to known disease) compared to standard 6 months chemotherapy. PATIENT AND METHODS: A total of 258 patients, mostly Stage IV, were randomized to four treatment regimens consisting of six cycles of CCNU, vinblastine, procarbazine, and prednisone (CVPP); 12 cycles of CVPP; six cycles of CVPP followed by 25 Gy radiotherapy; or three cycles CVPP, 25 Gy radiotherapy, and three cycles CVPP. RESULTS: Complete remissions were achieved in 65% of all patients. A 58% overall 5-year survival rate was obtained. Relapses in irradiated areas of known disease occurred in only 6% of responding patients. There was, however, no statistical difference in response frequency, disease-free survival, or overall survival among the four regimens. Elderly patients responded less frequently. CONCLUSION: While radiotherapy provided control of local (known) disease, no impact on overall survival was apparent. Likewise, doubling the duration of chemotherapy did not improve response or survival. Augmentation of therapy with either radiotherapy or more chemotherapy in this study was of no benefit compared to the standard 6 months of treatment.
Adult↗
Prevalence of renal stones in a population-based study with dietary calcium, oxalate, and medication exposures.
Little is known about the epidemiology of renal stones, in spite of the relative frequency of this painful condition. This population-based study examined reported renal stone diagnosis in 1,309 women aged 20-92 years to determine whether renal stones are associated with 1) food or water exposures or 2) lower bone mineral density and an increased likelihood of fractures. Results indicated a renal stone prevalence of 3.4%. The average age at diagnosis was 42 years. Renal stone formation was not associated with community of residence, hypertension, bone mineral density, fractures, high-oxalate food consumption, or ascorbic acid from food supplements. Women with renal stones consumed almost 250 mg/day less dietary calcium (p < 0.01) than did women without stones and had a lower energy intake (p < 0.04). The authors' findings do not support the hypothesis that increased dietary calcium is associated with a greater prevalence of renal stones, nor do they identify renal stones as a risk factor for low bone mineral density. Furthermore, lack of other identifiable environmental correlates and the relatively young age at initial diagnosis suggest that genetic components of renal stone formation need further study.
Adult↗
Evaluating persistent pain in long term care residents: what role for pain maps?
The purpose of this study was to examine the utility of the pain map as a pain assessment tool in frail nursing home residents. The study was conducted in two phases. In Phase 1, nursing home staff's knowledge of the locations of resident pain complaints was examined. We found significant deficiencies in this knowledge. In Phase 2, we examined the following test characteristics of pain extensity (number of painful body areas annotated on pain map): (1) test-retest reliability, (2) convergent validity as compared with pain intensity measured by a pain thermometer (modified vertical verbal descriptor scale) and an 11 point numerical graphic rating scale (NGRS), and (3) predictive validity with depression, functional impairment and self-rated health. Pain map scoring was performed by counting the number of involved body areas (i.e., numbered segments) using an established scoring template. Test-retest reliability by body area was excellent. Pain extensity was modestly associated with pain thermometer-scored pain intensity but not with NGRS-scored pain intensity. Pain extensity also demonstrated modest predictive validity with self-rated health, but not with depression or functional impairment. The advantage of knowing where residents hurt is that this allows staff to target their assessment and thus determine the functional implications of residents' pain. It appears that pain maps add a useful dimension to pain assessment in residents of long term care facilities.
Adult↗
Double esterase staining and other neutrophilic granule abnormalities in 237 patients with the myelodysplastic syndrome studied by the cancer and leukemia group B.
We investigated double (specific and nonspecific) esterase (DE) staining in marrow cells of 237 patients with the myelodysplastic syndromes (MDS). Additional abnormalities of neutrophilic granules were examined cytochemically and immunocytochemically for myeloperoxidase activity and antigen elastase, lactoferrin and CD15 granule-membrane glycoproteins. Abnormal DE staining (>/=3% of all nucleated marrow cells) was present in 27% of patients with no difference among different MDS subtypes. However, the prevalence of high abnormal DE staining (>/=10%) was significantly lower in refractory anemia with excess blasts in transformation (1%) compared to other MDS subtypes (12-15%; p = 0.004). The prevalence of other granule abnormalities was not statistically different in the DE normal and DE abnormal groups. Abnormal DE staining is relatively common among all MDS subtypes. High DE staining may identify a subgroup of patients with a lower grade MDS.
Bone Marrow Cells↗
Progression of Alzheimer's disease in black and white patients: the CERAD experience, part XVI. Consortium to Establish a Registry for Alzheimer's Disease.
We compared the progression of Alzheimer's disease (AD) in CERAD-enrolled black and white patients, as indicated by changes in selected clinical and neuropsychology measures, over a 1-year time interval. Of 225 black and 935 white AD patients who were enrolled, 148 (66%) black and 770 (82%) white patients remained in the study. Of these, 82 black and 532 white patients provided complete in-person information on first annual re-evaluation. Overall, with age, education, initial level of performance on each measure, and stage of disease at entry controlled, race had a very mild effect on change in disease (8 df multivariate analysis of variance [MANOVA], p < 0.047). Black patients showed less decline than white patients, most notably for the CERAD Boston Naming test (p < 0.02) and the third and final trial of the 10-item Word List Learning task (p < 0.003). Although unadjusted data indicate that black and white patients appear to differ notably at entry, our findings indicated that differences in progression of the dementing process are minor, suggesting that course of AD is comparable in these racial groups. Examination over a longer period is difficult because of the high attrition rate of black patients.
Aged↗
Association of chromosome 11 locus D11S12 with histology, stage, and metastases in lung cancer.
We have reported frequent allele loss for the marker D11S12 on chromosome band 11p15.5 in human lung cancer. The smallest common region of allele loss has been refined to approximately 500 kb and is confined between D11S1758 and D11S860. Here, we investigated the association of D11S12 allele loss with epidemiologic, pathologic, and clinical parameters. Analysis of allele loss was performed by Southern blotting on a cohort of 156 patients with lung cancer, and data were interpreted with the use of a phosphorimager. Results were statistically compared with retrospectively collected variables. D11S12 allele loss was found in 88% of small cell carcinomas, 57% of squamous cell carcinomas, and 40% of adenocarcinomas. Allele loss was associated with tumor stage (p = 0.04) and was more frequent in tumors that had already metastasized. These results suggest that a gene in the D11S12 region may be responsible for the metastatic potential of lung cancer. The functional status of this gene may thus be of future value in guiding clinicians on decisions regarding adjuvant and neoadjuvant therapies for patients with lung cancer.
Aged↗
A compilation of the thoughts of George W. Northup, DO, on the philosophy of osteopathic medicine.
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History, 20th Century↗
Preferential exclusion of sucrose from recombinant interleukin-1 receptor antagonist: role in restricted conformational mobility and compaction of native state.
Understanding the mechanism for sucrose-induced protein stabilization is important in many diverse fields, ranging from biochemistry and environmental physiology to pharmaceutical science. Timasheff and Lee [Lee, J. C. & Timasheff, S. N. (1981) J. Biol. Chem. 256, 7193-7201] have established that thermodynamic stabilization of proteins by sucrose is due to preferential exclusion of the sugar from the protein's surface, which increases protein chemical potential. The current study measures the preferential exclusion of 1 M sucrose from a protein drug, recombinant interleukin 1 receptor antagonist (rhIL-1ra). It is proposed that the degree of preferential exclusion and increase in chemical potential are directly proportional to the protein surface area and that, hence, the system will favor the protein state with the smallest surface area. This mechanism explains the observed sucrose-induced restriction of rhIL-1ra conformational fluctuations, which were studied by hydrogen-deuterium exchange and cysteine reactivity measurements. Furthermore, infrared spectroscopy of rhlL-1ra suggested that a more ordered native conformation is induced by sucrose. Electron paramagnetic resonance spectroscopy demonstrated that in the presence of sucrose, spin-labeled cysteine 116 becomes more buried in the protein's interior and that the hydrodynamic diameter of the protein is reduced. The preferential exclusion of sucrose from the protein and the resulting shift in the equilibrium between protein states toward the most compact conformation account for sucrose-induced effects on rhIL-1ra.
Chemical Phenomena↗
Determination of anti-HBsAg IgM monoclonal antibodies in cell culture media by perfusion immunoassay.
A rapid, specific, perfusion immunoassay for active anti-HBsAg monoclonal IgM is described. The immunoassay requires less than 3.5 min per sample. The precision was found to be 3.6% at an IgM concentration of 17 microg/ml. A detection limit of 1 microg/ml IgM in culture media was determined. Assay results were found to correlate very well with standard size exclusion chromatography and radial immunodiffusion techniques. This perfusion immunoassay was demonstrated to be useful for determining anti-HBsAg IgM in complex matrices such as cell culture media. The utility of the immunoassay for monitoring production of anti-HBsAg IgM in a perfusion bioreactor is demonstrated.
Animals↗