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Biomedical subjects

M C Long

Publications and source records attributed to M C Long.

At least 19 recordsLinked to original sources
PubMed2001

Pharmacokinetics study of a novel chimeric single-chain variable fragment antibody against western equine encephalitis virus.

A novel recombinant single-chain fragment variable (scFv) antibody against western equine encephalitis (WEE) virus has been previously constructed and partially characterized. The RS10B5huFc antibody was made by fusing an anti-WEE scFv to a human heavy-chain IgG1 constant region. The RS10B5huFc antibody was functional in binding to WEE virus in enzyme-linked immunosorbent assays (ELISAs), and the Fc domain of the antibody was capable of effector functions, such as binding to protein G and human complement. In this study, the RS10B5huFc antibody was further characterized by BIAcore analyses and was found to possess a binding affinity to a WEE virus epitope (K[D] = 9.14 x 10(-6) M), 4.5-fold lower than its parental mouse monoclonal antibody (MAb) 10B5 E7E2 (K[D] = 2 x 10(-6) M). No cross-reactivity was found between the RS10B5huFc antibody and three other alphaviruses (Sindbis virus [SIN], Venezuelan equine encephalitis [VEE] virus, and eastern equine encephalitis [EEE] virus). Pharmacokinetics studies showed that the RS10B5huFc antibody (free and encapsulated) was found to be retained in the lungs of mice for greater than 48 h when administered intranasally. In contrast, when administered intramuscularly to mice, the RS10B5huFc antibody was not detected in the lungs and only found in the liver and kidneys.

Administration, Intranasal↗
PubMed2000

Construction and characterization of a novel recombinant single-chain variable fragment antibody against Western equine encephalitis virus.

A novel recombinant single-chain fragment variable (scFv) antibody against Western equine encephalitis virus (WEE) was constructed and characterized. Using antibody phage display technology, a scFv was generated from the WEE specific hybridoma, 10B5 E7E2. The scFv was fused to a human heavy chain IgG1 constant region (CH1-CH3) and contained an intact 6 His tag and enterokinase recognition site (RS10B5huFc). The RS10B5huFc antibody was expressed in E. coli and purified by affinity chromatography as a 70-kDa protein. The RS10B5huFc antibody was functional in binding to WEE antigen in indirect enzyme-linked immunosorbent assays (ELISAs). Furthermore, the RS10B5huFc antibody was purified in proper conformation and formed multimers. The addition of the human heavy chain to the scFv replaced effector functions of the mouse antibody. The Fc domain was capable of binding to protein G and human complement. The above properties of the RS10B5huFc antibody make it an excellent candidate for immunodetection and immunotherapy studies.

Amino Acid Sequence↗
PubMed2000

Construction and characterization of monoclonal antibodies against western equine encephalitis virus.

A repertoire of mouse monoclonal antibodies (MAbs) against western equine encephalitis virus (WEE) was constructed and characterized. Anti-WEE antibodies were expressed from hybridomas and purified by protein G chromatography. Each of the antibodies was functionally assessed by indirect enzyme-linked immunosorbent assays (ELISAs), Western blotting, and immunoprecipitations. All antibodies bound to WEE antigen in ELISAs, whereas only a subgroup of antibodies was found to be active in Western blotting and immunoprecipitations. A subset of antibodies was found to cross-react with other alphaviruses, such as Sindbis virus (SIN), Venezuelan equine encephalitis (VEE), and eastern equine encephalitis (EEE). Because many of the antibodies were highly reactive to WEE antigen in one or more of the assays, these antibodies are excellent candidates for immunodetection and immunotherapy studies.

Animals↗
PubMed2000

Cost and quality under managed care: irreconcilable differences?

Managed care companies contend there is still waste in the healthcare system that should be eliminated. Healthcare providers argue that further cuts will reduce quality. Which side is right? In order to answer this question it is necessary to determine the threshold implicit in the corollary question: How far can we go in reducing healthcare expense without diminishing quality? A new variability based methodology is proposed that has the potential to determine the threshold at which cost reduction will negatively impact quality. Illustrations of its specific application are provided.

Cost Control↗
PubMed1999

ICP22 and the UL13 protein kinase are both required for herpes simplex virus-induced modification of the large subunit of RNA polymerase II.

Herpes simplex virus type 1 (HSV-1) infection alters the phosphorylation of the large subunit of RNA polymerase II (RNAP II), resulting in the depletion of the hypophosphorylated and hyperphosphorylated forms of this polypeptide (known as IIa and IIo, respectively) and induction of a novel, alternatively phosphorylated form (designated IIi). We previously showed that the HSV-1 immediate-early protein ICP22 is involved in this phenomenon, since induction of IIi and depletion of IIa are deficient in cells infected with 22/n199, an HSV-1 ICP22 nonsense mutant (S. A. Rice, M. C. Long, V. Lam, P. A. Schaffer, and C. A. Spencer, J. Virol. 69:5550-5559, 1995). However, depletion of IIo still occurs in 22/n199-infected cells. This suggests either that another viral gene product affects the RNAP II large subunit or that the truncated ICP22 polypeptide encoded by 22/n199 retains residual activity which leads to IIo depletion. To distinguish between these possibilities, we engineered an HSV-1 ICP22 null mutant, d22-lacZ, and compared it to 22/n199. The two mutants are indistinguishable in their effects on the RNAP II large subunit, suggesting that an additional viral gene product is involved in altering RNAP II. Two candidates are UL13, a protein kinase which has been implicated in ICP22 phosphorylation, and the virion host shutoff (Vhs) factor, the expression of which is positively regulated by ICP22 and UL13. To test whether UL13 is involved, a UL13-deficient viral mutant, d13-lacZ, was engineered. This mutant was defective in IIi induction and IIa depletion, displaying a phenotype very similar to that of d22-lacZ. In contrast, a Vhs mutant had effects that were indistinguishable from wild-type HSV-1. Therefore, UL13 but not the Vhs function plays a role in modifying the RNAP II large subunit. To study the potential role of UL13 in viral transcription, we carried out nuclear run-on transcription analyses in infected human embryonic lung cells. Infections with either UL13 or ICP22 mutants led to significantly reduced amounts of viral genome transcription at late times after infection. Together, our results suggest that ICP22 and UL13 are involved in a common pathway that alters RNAP II phosphorylation and that in some cell lines this change promotes viral late transcription.

Animals↗
PubMed1996

Attenuation of DNA-dependent protein kinase activity and its catalytic subunit by the herpes simplex virus type 1 transactivator ICP0.

The DNA-dependent protein kinase (DNA-PK) is involved in several fundamental nuclear processes, including DNA double-strand break repair, V(D)J recombination, and transcription by RNA polymerases I and II. In this study, we show that infection of mammalian cells with herpes simplex virus type 1 attenuates DNA-PK activity by specifically depleting the p350/DNA-PKcs catalytic subunit. The half-life of the p350/DNA-PKcs protein decreases from greater than 24 h to less than 4 h following infection. The depletion of DNA-PK activity and p350/DNA-PKcs abundance is dependent on expression of the viral immediate-early protein ICP0. As ICP0 acts as a promoter-independent transactivator of gene expression, these data suggest that ICP0 may function by directly or indirectly targeting the p350/DNA-PKcs subunit of DNA-PK, thereby altering the inhibitory effects of DNA-PK on RNA polymerase II transcription.

Amino Acid Sequence↗
PubMed1996

Death and dying and recognizing approaching death.

Although death is a natural part of life, most people attempt to escape death by ignoring it. It is vital, however, for all health care personnel to understand the stages of the dying process and signs and symptoms of approaching death in order to provide support for patients and families.

Attitude to Death↗
PubMed1995

Implementing a baccalaureate perioperative nursing elective.

To increase perioperative experience and knowledge, operating room staff members of a southeastern US veterans affairs hospital and the faculty of a nearby college of nursing baccalaureate program developed a perioperative nursing elective. The course included both classroom and clinical experiences. Benefits to students include the ability to transfer knowledge and skills to other clinical settings, increased understanding of the trauma of the surgical experience for the patient, and increased interest in a career in perioperative nursing.

Curriculum↗
PubMed1995

Herpes simplex virus immediate-early protein ICP22 is required for viral modification of host RNA polymerase II and establishment of the normal viral transcription program.

Infection of cells with herpes simplex virus type 1 (HSV-1) results in a rapid alteration of phosphorylation on the large subunit of cellular RNA polymerase II (RNAP II), most likely on its C-terminal domain (S. A. Rice, M. C. Long, V. Lam, C. A. Spencer, J. Virol. 68:988-1001, 1994). This phosphorylation modification generates a novel form of the large subunit which we have designed IIi. In this study, we examine roles that HSV-1 gene products play in this process. An HSV-1 mutant defective in the immediate-early transcriptional activator protein ICP4 is able to efficiently induce IIi. Viruses having mutations in the genes for the ICP0, ICP6, or ICP27 proteins are also competent for IIi formation. In contrast, 22/n199, an HSV-1 mutant which contains a nonsense mutation in the gene encoding the immediate-early protein ICP22, is significantly deficient in IIi induction. This effect is seen in Vero cells, where 22/n199 grows relatively efficiently, and in human embryonic lung (HEL) cells, where 22/n199 growth in more restricted. RNAP II is recruited into viral replication compartments in 22/n199-infected cells, indicating that altered phosphorylation of RNAP II is not a prerequisite for nuclear relocalization of RNAP II. In addition, we show by nuclear run-on transcription analysis that viral gene transcription is deficient in HEL cells infected with 22/n199. Viral late gene transcription does not occur efficiently, and antisense transcription throughout the genome is diminished compared with that of the wild-type HSV-1 infection. These transcriptional effects cannot be explained by differences in viral DNA replication, since 22/n199 replicates its DNA efficiently in HEL cells. Our results demonstrated that ICP22 is necessary for virus-induced aberrant phosphorylation of RNAP II and for normal patterns of viral gene transcription in certain cell lines.

Animals↗
PubMed1994

RNA polymerase II is aberrantly phosphorylated and localized to viral replication compartments following herpes simplex virus infection.

During lytic infection, herpes simplex virus subverts the host cell RNA polymerase II transcription machinery to efficiently express its own genome while repressing the expression of most cellular genes. The mechanism by which RNA polymerase II is directed to the viral delayed-early and late genes is still unresolved. We report here that RNA polymerase II is preferentially localized to viral replication compartments early after infection with herpes simplex virus type 1. Concurrent with recruitment of RNA polymerase II into viral compartments is a rapid and aberrant phosphorylation of the large subunit carboxy-terminal domain (CTD). Aberrant phosphorylation of the CTD requires early viral gene expression but is not dependent on viral DNA replication or on the formation of viral replication compartments. Localization of RNA polymerase II and modifications to the CTD may be instrumental in favoring transcription of viral genes and repressing specific transcription of cellular genes.

Animals↗
PubMed1993

Overview of substance abuse: implications for the primary care nurse practitioner.

NPs in primary care can expect a significant percent of their patient population to have a substance abuse disorder. This article provides the practitioner with foundational information on the epidemiology and neurophysiology of substance abuse, models and theories of addiction, and the physical and psychological effects of commonly abused substances. The commonly abused legal substances, nicotine and alcohol, are highlighted.

Humans↗
PubMed1992

Comparative study of nursing protocols for venous access ports.

The purpose of this study was to compare the incidence of infection in patients having venous access ports (VAP) accessed using commercially prepared kits with patients having VAPs accessed using a nursing protocol developed by RNs in the outpatient chemotherapy unit. The RN-developed protocol allowed venous access devices to be approached without sterile gloves and with minimal equipment, a technique which is more time efficient and cost effective. A convenience sample of 26 outpatients was randomly assigned to two groups. Patients in Group I, accessed using the commercially prepared kits, were accessed a total of 69 times. Patients in Group II, accessed using the nursing protocol, were accessed a total of 102 times. The two groups were compared for occurrence of infection as identified by elevated white blood count (WBC); febrile episode (greater than 100.4 degrees F); or drainage, pain, redness, swelling, or warmth at the port site. Data collected over a period of 6 months indicated no documented infection in either group. Results from this study will be used to support changes in nursing practice.

Adult↗
PubMed1989

Cardiovascular, pulmonary, and renal effects of massively increased intra-abdominal pressure in critically ill patients.

Massive elevation of intra-abdominal pressure (IAP) causes cardiovascular, respiratory, and renal dysfunction. We managed eight patients with high IAP (mean 51 +/- 7 cm H2O), six of whom had hemodynamic measurements; a clinical syndrome, characterized by hemodynamic, respiratory, and renal dysfunction, then became apparent. We report a) a baseline cardiopulmonary profile and response to an acute vascular volume challenge in six patients and b) surgical decompression of the abdomen in four patients. The clinical impression of hypovolemia was confused by small to normal left ventricular end-diastolic volume (64 +/- 14 ml) and normal ejection fraction (55 +/- 6%) despite very high right and left atrial filling pressures. Complete ventilatory support was necessary to maintain oxygenation and ventilation; oliguria (urine output less than 10 ml/h) was present. Pericardial effusion was absent. After fluid challenge (10 ml/kg of colloid or crystalloid infused iv over 10 min), filling pressures, cardiac output, and stroke volume all increased significantly (p less than .025) while heart rate decreased. Surgical decompression of the abdomen improved oxygenation, ventilation, cardiac output, atrial filling pressures, and urine output within 15 min. The cardiovascular effects of massively elevated IAP compounded by the requisite supportive care may require surgical relief.

Abdomen↗