Biomedical subjects
Publications and source records attributed to H A Thompson.
Charities or business associations frequently ask physicians--due to their status in the community--to serve as directors or officers. Just as frequently, physicians agree to serve in those positions without fully understanding the responsibilities and possible liabilities they are assuming. This article describes the duties of directors and officers and the liabilities associated with the job.
Sales of medical practices and physician employment contracts may contain covenants not to compete, also known as restrictive covenants. These covenants prohibit sellers from competing with buyers and employees from competing with former employers for a specified period of time. As a result of a call for legislative action to dispel confusion created by case law regarding these covenants, there now exists a statute dealing with restrictive covenants. This new law abolishes the "common calling" test, a standard for determining the enforceability of covenants not to compete in employment agreements, which the Texas Supreme Court adopted in 1987. Among other remedies, the new law provides procedures for reforming a broad restrictive covenant to one that is reasonable. This article discusses the 1987 Texas Supreme Court case and reviews the new statute.
This article traces the development of the informed consent concept, focusing on Texas case law and statutory provisions. We describe the proper use of the Texas Medical Disclosure Panel forms in establishing informed consent and illustrate common problems in proving that informed consent has been obtained. The need for effective physician-patient dialogue and communication is discussed.
All physicians regardless of their practice size will find themselves one day in the uncomfortable situation of dismissing an employee who may threaten legal action because of termination. Knowledge of and adherence to the basics of employment law as outlined in this article may not stop an angry dismissed employee from pursuing legal action. However, it should allow the physician to feel somewhat secure that such action likely will not be successful.
Medicare is a Federal Health Insurance Program administered by the Health Care Financing Administration for the elderly and certain disabled persons. The Texas Medicare carrier disseminates information and develops educational programs for improved understanding. "Concurrent care" exists when services are performed by more than one physician during a period of time for the same patient. Since Medicare does not have specialty designations for endocrinology, oncology, rheumatology, hematology, and infectious disease physicians, an X6 modifier is used for recognition. Services by two physicians of the same specialty or subspecialty rarely warrant coverage, but services by one physician and later care by another physician for an acute episode do warrant coverage. Emergency department codes should be used when care is given in that department and appropriate modifiers should be used by second- and third-opinion consultants in order to avoid the appearance of concurrent care. Diagnosis related to specialty and documentation of acute situations help avoid denial for "not reasonable or necessary" services. Physicians should use the "Waiver of Liability" when concurrent care seems necessary but is not likely to be covered by Medicare.
Jehovah's Witnesses believe that a human must not sustain his life with another creature's blood, and they recognize no distinction "between taking blood into the mouth and taking it into the blood vessels." It is their deep-seated religious conviction that Jehovah will turn his back on anyone who receives blood transfusions (1). Thus, Jehovah's Witnesses regularly refuse transfusions for themselves and their children because they believe the procedure creates a risk of losing eternal salvation. Legally, such refusals are based on the constitutional grounds that the transfusion is an invasion of the right of privacy and a violation of the individual's freedom of religious practice. When courts review these refusals they focus on state interests that outweigh the individual's rights. With an eye toward providing guidance to Texas physicians in dealing with such refusals, this article reviews case law on the subject of blood transfusions and Jehovah's Witnesses.
The American Academy of Family Physicians, the American Academy of Pediatrics, the American College of Obstetricians and Gynecologists, the Nurses Association of the American College of Obstetricians and Gynecologists, and the National Medical Association recently released guidelines aimed at protecting the privacy of adolescent patients. The organizations stated that, in many cases, young people will not confide in health professionals if the young people feel that these discussions will be reported to their parents. Ultimately, the organizations said, health risks to adolescents are so impelling that legal barriers and deference to parental involvement should not stand in the way of needed health care. In Texas there is a statute regarding consent for medical treatment of minors, which responds to the above organizations' concerns about confidentially treating children for substance abuse, sexually transmitted diseases, and suicide prevention. However, the statute is silent in regard to medical treatment involving prescription contraceptives. By negative inference, the statute would preclude a minor on her own from making a decision about abortion. This article examines Texas statutes dealing with consent for medical treatment for minors and discusses US Supreme Court decisions on a minor's rights to abortions and contraceptives.
The rate and extent of coliphage Q beta RNA translation by cell-free extracts prepared from Coxiella burnetii were studied. When translations were conducted at temperatures elevated above 37 degrees C, both polypeptide elongation and frequency of initiation were by comparison increased. The ratios of products synthesized from the polycistronic phage mRNA also changed upon increases in translation temperature, especially at 45 degrees C. Although the organism is a moderate acidophile, initiation of protein synthesis in extracts did not occur below pH 6.2, and was superior when the pH was 6.8-7.2. The results are discussed in context with the known physiological characteristics of this obligate intracellular bacterium.
We studied the effects of various mouse interferon preparations on the growth of Coxiella burnetii in mouse fibroblasts. The addition of both recombinant interferon-gamma and a crude lymphokine preparation that contained interferon-gamma to infected L929 cells inhibited the growth of C. burnetii, whereas the addition of a crude preparation of type I interferons did not. Cycloheximide suppressed the inhibitory effects of recombinant interferon-gamma and crude lymphokines.
The proteoglycans and glycosaminoglycans synthesized by embryonic mouse salivary glands during normal morphogenesis and in the presence of beta-xyloside, an inhibitor of branching morphogenesis, have been partially characterized. Control and rho-nitrophenyl-beta-D-xyloside-treated salivary rudiments synthesize proteoglycans that are qualitatively similar, based on mobility on Sepharose CL-4B under dissociative conditions and glycosaminoglycan composition. However, beta-xyloside inhibits total proteoglycan-associated glycosaminoglycan synthesis by 50%, and also stimulates synthesis of large amounts of free chondroitin (dermatan) sulfate. This free glycosaminoglycan accounts for the threefold stimulation of total glycosaminoglycan synthesis in beta-xyloside-treated cultures. Several observations suggest that the disruption of proteoglycan synthesis rather than the presence of large amounts of free glycosaminoglycan is responsible for the inhibition of branching morphogenesis. (a) We have been unable to inhibit branching activity by adding large amounts of chondroitin (dermatan) sulfate, extracted from beta-xyloside-treated cultures, to the medium of salivary rudiments undergoing morphogenesis. (b) In the range of 0.1-0.4 mM beta-xyloside, the dose-dependent inhibition of branching morphogenesis is directly correlated with the inhibition of proteoglycan synthesis. The stimulation of free glycosaminoglycan synthesis is independent of dose in this range, since stimulation is maximal even at the lowest concentration used, 0.1 mM. The data strongly suggest that the inhibition of branching morphogenesis is caused by the disruption of proteoglycan synthesis in beta-xyloside-treated salivary glands.
Coxiella burnetii was isolated from persistently infected fibroblast host cells by a rapid mechanical lysis technique. Macromolecular synthesis was initiated in these otherwise dormant cells by incubation at pH 4.5. The synthesis of protein proceeded for as long as 24 h. Initiation of protein synthesis in C. burnetii was dependent upon RNA synthesis. Approximately 24 species of polypeptides were synthesized, and some of these appeared to be major synthetic products. Increases in protein biomass of 15 to 30% were calculated to occur during incubation. Inhibition of DNA synthesis affected protein synthesis after 12 h of incubation. The results suggest that although these parasitic bacteria did not grow in the axenic media devised, significant biosynthetic processes occurred.
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Pichinde virus preparations were investigated for ribosomal components and associated activities. After detergent treatment and fractionation, viral components were assayed for polypeptide synthesis, elongation of nascent polypeptide chains, and mRNA activity. It was demonstrated that these subviral particles could synthesize polypeptides when exogenous mRNA template, aminoacyl--tRNAs, translation factors, GTP and appropriate cations were added. Undisrupted, whole virions could not synthesize polypeptide; disruption and subsequent centrifugation of subviral ribosomes was a prerequisite for the biosynthetic activity described.
The addition of coliphage Q beta ribonucleic acid to a cell-free translation system obtained from Coxiella burnetii cells caused the formation of monosomes and disomes from ribosomal subunits and resulted in synthesis of viral coat protein. Rickettsial ribosomes and associated translation factors functioned together, with fidelity, efficiency, and a specificity similar to those of free-living gram-negative bacteria.
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Some aspects of protein biosynthesis were investigated in extracts of the obligate intracellular bacterium Coxiella burnetti. Sucrose gradient analysis revealed small quantities of 30S and 50S ribosomal subunits, few 70S ribosomes and no polysomes. Functional endogenous mRNA was not detected. In translation of exogenously added poly(U), extracts required Mg2+ (17 mM) and NH4+ (60 mM) for optimal polyphenylalanine synthesis; the optimum MG2+ requirement differed from that of Escherichia coli. The translation of coliphage Q beta RNA by C. burnetti extracts required Mg2+ (13 mM), NH4+ (60 mM) and an energy source for polypeptide synthesis, and was sensitive to chloramphenicol but not to cycloheximide. Under optimal conditions, the translation of Q beta RNA proceeded at a rate and to an extent equal to that obtained in a conventional E. coli system. Electrophoretic analysis of translation products made during incubation of C. burnetti extracts with polycistronic Q beta RNA revealed a major product with a molecular weight of about 14 000; this product co-electrophoresed with the coat protein extracted from Q beta phage propagated in E. coli. The results suggested that the extracellular form of the rickettsia-like organism, C. burnetti, possessed the full array of components necessary for the initiation, elongation and termination of polypeptides.
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A population of free, native ribosomal 40S subunits, that do not react with 60S subunits to form 80S ribosomes, has been identified in the postmicrosomal fraction of rat liver homogenates. A protein (IF-3) has been purified from high salt (0.88 M KCI) extracts of native 40S subunits by gradient centrifugation and by ammonium sulfate fractionation; it prevents the reassociation of subunits and to a limited extent dissociates ribosomes to subunits. The activity is measured by ultracentrifugation of the reaction products on linear sucrose gradients, or with an assay developed in this laboratory that couples dissociation with the 60S-specific peptidyltransferase reaction; the latter procedure measures the amount of 60S subunits released from ribosomes or remaining in incubations in the presence of IF-3. Dissociation factor activity is recovered from most of the particles that are resolved by zonal centrifugation of the total "native subunits" obtained from the postmicrosomal fraction; the highest concentration of IF-3, however, appears to be associated with native 40S subunits. The purified dissociation factor IF-3 is composed of about ten polypeptides and the molecular weight is estimated to be between 500 000 and 700 000, on the basis of glycerol and cesium chloride gradient centrifugation. When purified 40S subunits react with IF-3 or when 80S ribosomes are dissociated by IF-3, a product is formed which is dependent on the concentration of the protein factor and has the characteristics of a 40SIF-3 complex; centrifugation of the complex on sucrose and cesium chloride gradients suggests that the complex consists of 1 equiv of each of the two components. Although dissociation factor IF-3 appears to react in a specific manner with free or ribosome-associated 40S subunits, the reaction with subunits differs in several respects from that with ribosomes. The dissociation factor also appears to interact with 60S subunits but multiple complexes are formed, some with more than 1 IF-3 equiv per 60S particle. The IF-3 converts 40S dimers (55S particles) to the 40S-IF-3 complex and dissociates free, native 80S particles present in the postmicrosomal fraction, but it does not affect polysome-associated ribosomes engaged in protein synthesis.