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Fluorescence Probes For The Study Of Acetylcholine Receptor Function, M. Martinez-Carrion, J.M. Gonzalez-Ros, J.R. Mattingly, J.A. Ferragut, M.C. Farach, D. Donnelly

Biochemistry and Molecular Biology Publications

Our group initiated the use of pyrene derivatives for functional and structural studies of the membrane-bound Acetylcholine Receptor (AcChR) system. Our studies have taken two approaches. We have recently used a hydrophobic derivative (pyrene-l-sulfonyl azide) that is able to bind covalently to regions of the AcChR molecule accessible from the membrane lipid (1) to monitor ligandinduced effects at those hydrophobic regions of the AcChR protein exposed to the membrane matrix (2). The structural effects induced by ligand binding are interpreted in relation to the AcChR "desensitization" process. We have also used a hydrophilic pyrene derivative (1,3,6,8-pyrene tetra sulfonate [PTSA]) to …

Potential And K+ Activity In Skinned Muscle Fibers. Evidence Against A Simple Donnan Equilibrium, R.E. Godt, C.M. Baumgarten

Physiology and Biophysics Publications

ABSTRACT

It has been suggested that potentials measured with conventional microelectrodes in chemically or mechanically skinned muscle fibers arise from a Donnan equilibrium due to myofilament fixed charges. This hypothesis was tested in mechanically skinned frog (Rana pipiens) semitendinosus fibers by measuring the distribution potential (Ed) between fiber and bath with 3 M KCI-filled microelectrodes and the K+ activity gradient (a'K/a) with K+ ion-selective microelectrodes (KISE). If skinned fibers are a Donnan system, Ed should become more positive as pH is decreased, altering the fixed charge on the myofilaments. Consistent with this expectation, Ed was -4.4, -0.6, and +4.8 mV …

Inability To Predict Relapse In Acute Asthma, Robert M. Centor , M.D., Barry Yarbrough , M.D., Judy P. Wood , P.A.

Internal Medicine Publications

No abstract provided.

Cellular Dna Content As A Predictor Of Response To Chemotherapy In Infants With Unresectable Neuroblastoma, A. Thomas Look, F. Ann Hayes, Ruprecht Nitschke, Nancy B. Mcwilliams, Alexander A. Green

VCU Health Publications

We studied the relation between the DNA content of neuroblastoma cells and the response to therapy in 35 infants under one year of age with a diagnosis of neuroblastoma. Using flow cytometric techniques, we found that in 27 cases the primary malignant stem line consisted of neuroblasts with hyperdiploid DNA content, ranging from 1.07 to 2.42 times the finding in normal diploid cells. All remaining cases had diploid stem lines. Diploidy was more common in infants with clinical Stage D neuroblastoma (metastases beyond regional lymph nodes) than in those with other, less advanced stages: 6 of 10 as compared with …

Ventriculostomy-Related Infections, C. Glen Mayhall, Nancy H. Archer, V. Archer Lamb, Alice C. Spadora, Jane W. Baggett, John D. Ward, Raj K. Narayan

VCU Health Publications

We conducted a prospective epidemiologic study of ventriculostomy-related infections (ventriculitis or meningitis) in 172 consecutive neurosurgical patients over a two-year period to determine the incidence, risk factors, and clinical characteristics of the infections. Ventriculitis or meningitis developed in 19 of 172 patients (11 per cent) undergoing a total of 213 ventriculostomies. When data from all these cases plus five cases of nonventriculostomy-related infection were combined, cerebrospinal-fluid pleocytosis was more significantly associated with the diagnosis of ventriculitis or meningitis (P<0.0001) than were fever and leukocytosis (P = 0.07). Risk factors for ventriculostomy-related infections included intracerebral hemorrhage with intraventricular hemorrhage (P = 0.027), neurosurgical operations (P = 0.016), intracranial pressure of 20 mm Hg or more (P = 0.019), ventricular catheterization for more than five days (P = 0.017), and irrigation of the system (P = 0.021). Previous ventriculostomy did not increase the risk of infection with subsequent procedures. We conclude that ventriculostomy-related infections may be prevented by maintenance of a closed drainage system and by early removal of the ventricular catheter. If monitoring is required for more than five days, the catheter should be removed and inserted at a different site. (N Engl J Med 1984; 310:553–9.)

Unidirectional Calcium And Nucleotide Fluxes In Sarcoplasmic Reticulum. I. Interpretation Of Flux Ratios For Different Reaction Schemes, J. J. Feher

Physiology and Biophysics Publications

The relation between unidirectional calcium and nucleotide fluxes was examined for different ATPase reaction schemes of the sarcoplasmic reticulum. The schemes considered differed in the order of sorption and desorption of calcium, ATP, and ADP. The results suggest that the theoretical relation between calcium and nucleotide fluxes depends on the reaction scheme and that experimental measurements can distinguish among them. The results obtained are generally valid and do not depend on assumptions of equilibrium or pseudoequilibrium between intermediate states of the pump.

Undirectional Calcium And Nucleotide Fluxes In Cardiac Sarcoplasmic Reticulum. Ii. Experimental Results, J. J. Feher, F. N. Briggs

Physiology and Biophysics Publications

Unidirectional calcium influx and efflux were evaluated in cardiac sarcoplasmic reticulum (SR) by 45Ca-"0Ca exchange at steady state calcium uptake in the absence of calcium precipitating anions. Calcium efflux was partitioned into a pump-mediated efflux and a parallel passive efflux by separately measuring passive efflux referable to the steady state. Unidirectional and net ATP-ADP fluxes were measured using [3H]-ATP -- ADP and [3H]- ADP -- ATP exchanges. Methods are presented that take into account changing specific activities and sizes of the nucleotide pools during the measurement of nucleotide fluxes. The contribution of competent and incompetent vesicles to the unidirectional and …

Virginia Dental Journal (Vol. 61, No. 6, 1984)

Virginia Dental Journal

No abstract provided.

Virginia Dental Journal (Vol. 61, No. 3, 1984)

Virginia Dental Journal

No abstract provided.

Virginia Dental Journal (Vol. 61, No. 1, 1984)

Virginia Dental Journal

No abstract provided.

Virginia Dental Journal (Vol. 61, No. 2, 1984)

Virginia Dental Journal

No abstract provided.

Virginia Dental Journal (Vol. 61, No. 4, 1984)

Virginia Dental Journal

No abstract provided.

Firo-B Profiles Of Physical Therapy Students And Their Performances In Clinical Education, Nora Donohue

Theses and Dissertations

The purpose of this research was to determine if there was a relationship between physical therapy students' personalities and their preferences in clinical education. Associated problems addressed by the research were to determine if there were differences in personality measures between the physical therapy students as well as differences from one another in how they rank ordered a list of clinical education methods and behaviors.

Thirty-four senior physical therapy students who had completed the academic and clinical requirements of the curriculum rank ordered a list of twenty clinical education methods and behaviors which was compiled from factors cited in the …

Virginia Dental Journal (Vol. 61, No. 5, 1984)

Virginia Dental Journal

No abstract provided.

The Relationship Between Oral Contraceptives And Intraepithelial Neoplasia Of The Uterine Cervix, Barbara Jeannette Fox

Theses and Dissertations

The purpose of this study was to determine the relationship between specific oral contraceptive use and cervical intraepithelial neoplasia (CIN), and to determine if duration of use and content of oral contraceptives were related to CIN. The hypotheses tested in this study were: (1) norgestrel-containing oral contraceptives are associated with more severe levels of CIN, and (2) longer duration of oral contraceptive use is associated with more severe CIN.

Data was collected from 52 clinical records of clients who attended a colposcopy clinic during a four month period. Clients included in the study were utilizing one of five specific oral …

The Effect Of Social Support On The Blood Pressure Of Mild And Moderate Hypertensives, Edith Price Vaughan

Theses and Dissertations

The study was conducted to determine the relationship between social support and the blood pressure of mild and moderate hypertensives. Motivation for the study was derived from the growing realization that the social support of an individual has a far-reaching effect on illness and health and that little research has been done concerning the specific effect that social support has on blood pressure.

The Norbeck Social Support Questionnaire (NSSQ) was administered to a convenience sample of 30 subjects selected from among the hypertensive clients of the Family Practice Clinic and General Medical Clinic located in the Peninsula Health Center. The …