Trends in office-based practice under managed care.
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Drug Prescriptions↗
Biomedical subjects
J Kahan
Publications and source records attributed to J Kahan.
Cumulative industrial trauma as an etiology of seven common disorders in the foot and ankle: what is the evidence?
The concept of cumulative industrial trauma as an etiology of orthopaedic disease has recently generated considerable attention in both the medical and legal communities. To clarify the current state of knowledge about the issue as applied to the foot and ankle, we critically reviewed the literature on the etiology of seven foot and ankle disorders commonly involved in compensation litigation in the practice of the senior author: hallux valgus, interdigital neuroma, tarsal tunnel syndrome, lesser toe deformity, heel pain, adult acquired flatfoot, and foot and ankle osteoarthritis. Koch's postulates were appropriately modified and used as a logistic framework to analyze the potential for cumulative industrial trauma to cause foot pathology. In none of the disorders analyzed could cumulative industrial trauma reasonably satisfy even one of Koch's three postulates. We conclude there is currently no unequivocal literature support upon which to invoke cumulative industrial trauma as a clear etiology of these disorders of the adult foot and ankle. The superb evolutionary adaptation of the human foot to prolonged ambulation and the absence of industrial demands that significantly differ from this task likely account for this dramatically reduced vulnerability of the foot to industrial repetitive motion disorders compared to the upper extremity.
Ankle Injuries↗
Effects of job characteristics, team climate, and attitudes towards clinical guidelines.
The aim of this study was to form and test a model of the antecedents and possible moderators of the use of clinical guidelines among healthcare professionals. A postal questionnaire survey of all workers in six health centres around Finland. was carried out in April 1996. The health centres were selected to represent all different areas of Finland. A total of 748 (65.5%) of the healthcare workers completed and returned the questionnaire. Of the respondents 95% were women, 16% physicians or dentists, 31% registered nurses, and 27% practical nurses. It was hypothesized that besides positive attitudes towards guidelines, job characteristics and team climate affect the use of guidelines. Three alternative models of possible main and moderating effects of attitudes, job characteristics, and team climate were formed and tested. These models were tested using hierarchical regression analysis and structural equation modelling (LISREL8). All of the hypothesized main effects and the moderating effect of job characteristics between attitudes towards and the use of guidelines were supported. According to our results important factors behind the general positive or negative attitudes towards guidelines are the usefulness, reliability, practicality, and availability of the guidelines. Also, the overall individual, team, and organizational competence to follow the procedures recommended, seemed to be vital. Moreover, those whose job motivation potential was high were more ready to use clinical guidelines even when their attitudes towards guidelines were the same.
Attitude of Health Personnel↗
Molecular analysis of the cyclin-dependent kinase inhibitor genes, p15, p16, p18 and p19 in the myelodysplastic syndromes.
The myelodysplastic syndromes (MDS) are a heterogeneous group of clonal blood disorders characterized by dyshematopoiesis with a frequent evolution to acute leukemia. Chromosomal deletions rather than translocations are the predominant karyotypic abnormalities in MDS, suggesting a recessive mechanism in the pathogenesis of MDS, such as inactivation of tumor suppressor genes. A group of cyclin-dependent kinase inhibitors, p15 (INK4B), p16 (INK4A), p18 (INK4C) and p19 (INK4D), are candidate tumor suppressor genes. To determine whether genetic alterations of these genes play an important role in the development and/or progression of MDS, we examined 46 samples from MDS patients by Southern blotting, single-strand-conformation polymorphism (SSCP) using polymerase chain reaction (PCR) and sequencing of DNA. These samples included 13 refractory anemias (RA), four refractory anemias with ringed sideroblasts (RARS), 16 refractory anemias with an excess of blasts (RAEB), eight refractory anemias with an excess of blasts in transformation (RAEB-T) and five chronic myelomonocytic leukemia (CMMoL) samples. Except for allelic polymorphisms or silent point mutations, no alterations of coding regions of these four CDKI genes were identified. In summary, genetic abnormalities of the p15, p16, p18 and p19 genes are rare events in the development and/or progression of MDS.
Blotting, Southern↗
N-ras mutations are associated with poor prognosis and increased risk of leukemia in myelodysplastic syndrome.
To evaluate the clinical significance of N-ras mutations in the myelodysplastic syndrome (MDS) archival bone marrow samples from 252 patients were studied for the presence of N-ras exon I mutations using polymerase chain reaction amplification and differential oligonucleotide hybridization. Subsequently, clinical information about these patients was obtained and analyzed. Of 220 evaluable patients, 20 (9%) had point mutation of N-ras involving codon 12. Individuals with N-ras mutation had a significantly shorter survival period than those who were N-ras negative (P = .02). An increased risk of acute myelogenous leukemia (AML) was also found in patients with N-ras mutations (P = .005). N-ras mutations were not associated with any French-American-British (FAB) subtype, with the presence of increased myeloblasts, or with chromosomal aberrations in the bone marrow. However, the presence of increased bone marrow blasts was strongly associated with poor survival rate and risk of AML (P < .001 for each). After stratifying for the percentage of blasts, N-ras mutations remained significantly associated with shorter survival period (P = .04) and increased risk of AML (P = .02). Bone marrow cytogenetic abnormalities, particularly when multiple abnormalities were present, were significantly associated with a poor prognosis (P < .001). In conclusion, N-ras mutation, although relatively infrequent in MDS, is associated with short survival period and increased probability of developing AML.
Bone Marrow↗
N-ras gene point mutations in childhood acute lymphocytic leukemia correlate with a poor prognosis.
Ras genes can be altered by point mutations at critical portions of their coding regions to acquire transforming ability in vitro. These point mutations have been detected in a variety of human malignancies. However, their relevance for the clinical and biologic behavior of the subgroups of patients exhibiting these mutations in unclear. We analyzed 100 patients with childhood acute lymphocytic leukemias (ALLs) for point mutations of exons 1 and 2 of all three ras genes (H-ras, K-ras, and N-ras) by polymerase chain reaction and a combination of oligonucleotide hybridization and direct DNA sequencing. A 6% incidence of N-ras gene mutations was detected, all of which occurred at different nucleotides of codons 12 or 13 of N-ras. When correlating presence of ras mutations with the clinical and biologic features and the clinical outcome of these cases, a significantly higher risk for hematologic relapse (P = .01) and a trend toward a lower rate of complete remission (P = .07) was noted. The two groups did not differ in any of the known high-risk factors of ALL. These results suggest that presence of an N-ras mutation in children with ALL may be an independent predictor for worse clinical outcome and therefore may have therapeutic implications; further studies to confirm these findings are required because of the small number of patients with N-ras mutations.
Antigens, CD↗
Expression, methylation and chromatin structure of the p53 gene in untransformed and human T-cell leukemia virus type I-transformed human T-lymphocytes.
p53 is a nuclear protein associated with cellular transformation and normal cellular proliferation. Some transformed cells have been found to have one or several quantitative or qualitative abnormalities of p53. We studied expression, kinetics, phosphorylation, DNA methylation and chromatin structure of p53 in resting and proliferating untransformed T-lymphocytes and in human T-cell leukemia virus type I transformed T-lymphocytes from the same individuals. p53 expression is indistinguishable in transformed compared to untransformed proliferating T-lymphocytes by: (1) p53 mRNA levels, (2) rate of synthesis and stability of p53 protein, (3) change in protein stability after exposure to an inhibitor of protein synthesis, (4) presence of phosphorylation of the p53 protein. Resting T-lymphocytes from these same individuals did not express p53. No difference in DNA methylation and chromatin structure of the p53 gene was observed in either resting or proliferating untransformed, or virally transformed T-lymphocytes. The gene was fully methylated and resistant to DNAase I over its entire coding region but was demethylated and contained DNAase I hypersensitive sites in a distinct region 5' of the site of initiation of transcription.
Cell Line↗
Measurement of alkaline phosphatase activity by kodak Ektachem 700 XR analyzer compared with other routine analytical methods.
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Alkaline Phosphatase↗
Prognosis of herpes zoster in healthy children.
Previous investigators have suggested that herpes zoster may be the presenting sign of a malignancy. However, no data have been available concerning the prognosis of herpes zoster in normal children. To assess outcome and prognosis for healthy children with a diagnosis of herpes zoster, we collected and reviewed 22 cases of herpes zoster from 90 pediatric practices in our community. In all cases, the illness was of short duration and resolved completely. Patients were followed up by their pediatricians for a mean of 4.2 years, and in no case did malignancy manifest subsequent to the zoster infection. We conclude that herpes zoster is a relatively benign infection in children and, given the period of follow-up, the onset of zoster does not appear to herald the occurrence of malignancy in this population.
Adolescent↗
Personality and multiple divorce. A prospective study.
A review of cross-sectional and prospective research in both normal and clinical samples suggests that increased risk of divorce is associated with socially nonconforming, impulsive, and stimulus-seeking personality traits. This exploratory study addresses the question of whether individuals who divorce more than once are especially likely to exhibit such general personality dispositions. Subjects were male physicians (N = 431) who had completed the MMPI before entering medical school and who were followed up more than two decades later by a mail questionnaire that inquired about their health status, health practices, subjective well-being, and marital history. As indicated by higher scores on the MMPI Psychopathic Deviate (Pd) scale and greater likelihood of concurrently reporting several negative health practices (e.g., cigarette smoking), multiply divorced physicians did tend to exhibit greater nonconforming, impulsive, and risk-taking tendencies than both never-divorced and once-divorced physicians. Possible social-psychological processes linking such personality dispositions to the risk of multiple divorce are discussed, along with suggestions for further research.
Adult↗
Decreasing the burden in families caring for a relative with a dementing illness. A controlled study.
The purpose of this study was to investigate the efficacy of a specifically designed group support program for relatives of patients with Alzheimer's disease and related disorders. The group program included educational/supportive activities and used basic principles of the cognitive-behavioral approach. Twenty-two subjects participated in an eight-session program. Eighteen control subjects received no treatment. Measures of family burden, levels of depression, and knowledge of dementia were obtained. Experimental subjects showed a significant decrease in total family burden, whereas control subjects actually showed a significant increase, experimental subjects also showed reduction in their levels of depression. Experimental subjects showed a significantly greater improvement than did control subjects on knowledge of dementia. The acquisition of new knowledge was an important ingredient in reducing perception of burden and levels of depression, but other facets of the intervention also accounted for the improvement. Results indicated that a relatively short but intensive support experience can have a positive effect in reducing some of the burden and depression associated with the care of a demented relative.
Adolescent↗
Proposal for a distinctive diagnosis: the deliberate self-harm syndrome (DSH).
Self-destructive behavior is a major clinical problem in psychiatry. A review of the literature reveals the existence of enough clinical data to identify a diagnostic entity, "The Deliberate Self-Harm Syndrome" (DSH). The authors present a diagnostic formulation of the DSH syndrome (in the DSM-III format) which consists of four essential clinical features, a group of associated features, clinical features, a group of associated features, a clinical course of typical onset in late adolescence, with multiple recurrent episodes, with multiple methods of low lethality physical self-injury, extending over many years. On the basis of relatively exclusive association of clinical signs and symptoms a heuristic clinical entity is proposed.
Adolescent↗
The deliberate self-harm syndrome.
Recent research has differentiated several distinct classes of self-destructive behavior. This paper describes the clinical characteristics of one class, the deliberate self-harm syndrome. Analysis of 56 published case reports of self-harm revealed a typical pattern of onset in late adolescence, multiple recurrent episodes, low lethality, harm deliberately inflicted upon the body, and extension of the behavior over many years. Since the clinical characteristics of the deliberate self-harm syndrome differ substantially from those of other classes of self-destructive behavior, the authors propose that DSM-IV classify deliberate self-harm as a separate diagnostic syndrome.
Adolescent↗
Use of a lyophilized reference plasma to compare coagulation test procedures: Normotest, Simplastin-A and Thrombotest.
In 4 collaborative trials, involving a varying number of hospital laboratories in the Stockholm area, the coagulation activity of different test materials was estimated with the one-stage prothrombin tests routinely used in the laboratories, viz. Normotest, Simplastin-A and Thrombotest. The test materials included different batches of a lyophilized reference plasma, deep-frozen specimens of diluted and undiluted normal plasmas, and fresh and deep-frozen specimens from patients on long-term oral anticoagulant therapy. Although a close relationship was found between different methods, Simplastin-A gave consistently lower values than Normotest, the difference being proportional to the estimated activity. The discrepancy was of about the same magnitude on all the test materials, and was probably due to a divergence between the manufacturers' procedures used to set "normal percentage activity", as well as to a varying ratio of measured activity to plasma concentration. The extent of discrepancy may vary with the batch-to-batch variation of thromboplastin reagents. The close agreement between results obtained on different test materials suggests that the investigated reference plasma could be used to calibrate the examined thromboplastin reagents, and to compare the degree of hypocoagulability estimated by the examined PIVKA-insensitive thromboplastin reagents. The assigned coagulation activity of batches of the reference plasma agreed closely with experimentally obtained values. The stability of supplied batches was satisfactory as judged from the reproducibility of repeated measurements. The variability of test procedures was approximately the same on different test materials.
Anticoagulants↗
Assessment of different mathematical models for calculating and expressing the results of coagulation test procedures.
Coagulation activity, expressed as percentage of normal and as clotting time ratio, was estimated in 220 specimens from patients on long-term anticoagulant treatment by 3 different coagulation test procedures, i.e. Thrombotest, Simplastin-A and Normotest. The estimates were calculated from the same determinations. The distribution of percentage values showed a fairly pronounced deviation from normality. After logarithmic transformation, the distribution was normalized, the regression lines between Thrombotest and other tests became parallel, and that between PIVKA-insensitive systems was shifted to a 45 degree line. Logarithmic transformation also stabilized the residual variance. These features make percentage values accessible for treatment according to the standard methods of bioassay statistics. Attempts to normalize the distribution of ratio values by various transformations were unsuccessful. Formal analysis of data revealed a variation in the proportionality of ratio values with the level of estimated coagulation defect. This may restrict the usefulness of the ratio approach. Logarithmic transformation partly reduced the discrepancy.
Analysis of Variance↗
Inter- and intra-laboratory variation of haemoglobin measurement.
The preparation of a stable and inexpensive equine haemoglobin solution for quality control of haemoglobin measurement is described. Twenty-one different batches of the preparation were analysed by 19 hospital laboratories during a 19-month period, and the results of 4457 determinations are evaluated. Systematic divergences between laboratories were found to contribute to the variability of haemoglobin measurement more than random variation. Interlaboratory variation was mainly due to different types of automated techniques, the frequency of the calibration of photometers, the use of different reagent solutions, and the qualification of laboratory staff. Intralaboratory variation was related to the frequency of the calibration of photometers and the qualification of the laboratory staff. The data reported in this study indicate the usefulness of the test preparation for the quality control of haemoglobin measurements.
Animals↗
Regional quality control of coagulation assay procedures (normotest, simplastin-a and thrombotest).
The report is based on the first 8 months' operation of an extended regional quality control program involving 20 hospital laboratories in the Stockholm area. The test material was commercially available lyophilized human reference plasma containing uniformly reduced levels of factors II, VII and X, and optimal concentrations of fibrinogen and factor V. Each participant received 2 batches of the test material with different activity at each 4-week period. Participants were requested to analyze the specimens, independently and in duplicates, along with ordinary patient samples three times weekly during each period. The levels of the factors in the batches were changed in each period. The total number of reported results was 3113. The statistical analysis of values included the calculation of means and variances within and between different thromboplastins (Normotest, Simplastin-A, Thrombotest), different techniques (venous and capillary blood, automatic and manual end-point determination), and laboratories classified according to the category and number of personnel and of performed coagulation tests. Systematic differences between thromboplastins, techniques and laboratories, even using the same type of thromboplastin, contributed a significantly greater amount than within-laboratory random variation to the total variation of determinations. The obtained results indicate the urgency of the quality control of coagulation activity tests.
Analysis of Variance↗
Automated fluorometric assay of vitamin A in pharmaceutical preparations.
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Autoanalysis↗