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Biomedical subjects

B Parker

Publications and source records attributed to B Parker.

At least 73 records · Page 4Linked to original sources
PubMed1987

Rapid alkaline blot-transfer of viral dsRNAs.

The double-stranded genomic RNAs of reovirus and bluetongue virus can be transferred very efficiently from either sodium dodecyl sulfate-polyacrylamide gels or NuSieve agarose gels onto several nylon membranes. After a brief acid depurination treatment, viral dsRNAs from the gels are transferred at room temperature using 0.2 N NaOH as the transfer medium. Four blots can be obtained within 1 h and each blot contains 15-20% of the input RNA sample. These blots can be used immediately without baking in vacuo. Less than 5% of the "fixed" dsRNAs are removed after repeated washings of the membrane blots. As little as 10 pg of the genomic dsRNA segment can be detected in this alkaline Northern blot. A 20- to 50-fold increase in resolution and sensitivity over traditional Northern blots is routinely achieved. These alkaline blots can be reused 6-10 times after appropriate strip washing and proper handling.

Bluetongue virus↗
PubMed1987

Parental history of hypertension and screening attendance: effects of wellness appeal versus threat appeal.

This study examined whether the orientation of a health appeal differentially influences health beliefs and early-detection practices among young individuals who are potentially at risk. Undergraduates with and without a hypertensive parent were given printed material about hypertension and the importance of early detection framed in either a wellness or illness-threat format. The major dependent measure was attendance at a blood pressure screening during the week following the experimental session. Results showed that parental history (PH) participants were more than twice as likely to attend the screening when given a wellness message in comparison to threat. In the threat condition, PH participants also reported that hypertension was less preventable in comparison to participants without a hypertensive parent. Reported likelihood of developing hypertension was inversely related to subsequent screening attendance among PH participants only. Factors accounting for the efficacy of wellness-oriented appeals among individuals who report a family history are discussed.

Adult↗
PubMed1987

Operative management of intra-articular fractures of the distal humerus.

Over a 5-year period (1979-1984), 33 patients with intra-articular fractures of the distal humerus underwent open reduction and internal fixation of their fractures. Twenty-two (67%) of the patients had multiple injuries. Fourteen (42%) of the fractures were open (1 was Grade I, 8 were Grade II and 5 were Grade III). The mean age was 32 years (range: 15-61 years), which is significantly younger than in other series. A subgroup of 25 of the patients was evaluated clinically at a mean of 18.3 months postoperatively. "Excellent" and "good" functional results occurred in 23 patients (92%). "Poor" results were seen in the remaining two patients (8%). Complications occurred in 15 patients (45%). Nine of these complications related to fixation of the transolecranon osteotomy, which was used in 29 patients. The method by which reduction and stabilization was achieved was not as important as obtaining sufficient rigidity, which permitted early motion.

Adolescent↗
PubMed1987

Severity of Illness Index and the Adverse Patient Occurrence Index. A reliability study and policy implications.

Seven hundred fifty-two randomly selected charts from seven teaching hospitals were rated by pairs of medical record analysts. The Severity of Illness Index was unreliable with an interrater-agreement rate of 73% (kappa statistic = 0.41), and demonstrated a significant (P less than 0.0001) association with the Adverse Patient Occurrence (APO) Index. This suggests that the Severity of Illness Index is not differentiating severity of illness from quality of care. The fair to poor field reliability stems from underlying instrument subjectivity, lack of clear referent groups, and time pressure. The APO Index was also found to be unreliable (r = 0.33 and range = -0.05-0.58). Greater attention should be directed to improving objective discharge abstract, billing, and laboratory data for measuring patient severity and adverse patient occurrences.

Abstracting and Indexing↗
PubMed1986

Prospective payment for psychiatry--feasibility and impact.

Although 15 diagnosis-related groups (DRGs) have been proposed for psychiatric hospital patients, psychiatric hospitals are currently exempt from the DRG prospective payment system. We investigated the ability of the psychiatric DRGs to predict the hospital length of stay and costs by retrospectively analyzing the charts of 8816 randomly selected patients from 32 psychiatric hospitals throughout the United States. In addition, we developed other grouping systems to see whether they would have been better predictors of length of stay. We found that grouping the patients in the 15 psychiatric DRGs reduced the total variance in length of stay by only 3.9 percent. Furthermore, our best alternative grouping--based on major diagnostic categories, whether the patient was transferred from another facility, age, and psychiatric complications and comorbidities--reduced the variance by only 7.8 percent. We conclude that DRGs do not adequately predict length of stay or costs in psychiatric hospitals. We identified factors other than diagnosis that predicted the length of stay better, but all the models we tested would create large financial "winners" and "losers" and thus introduce inappropriate incentives into the care of patients in psychiatric hospitals.

Costs and Cost Analysis↗
PubMed1986

A new Golgi method for adult human brains.

A new fast and reliable Golgi method to impregnate neurons in adult human brains which have been routinely fixed in neutral buffered formalin is described. In addition to potassium dichromate and sucrose, this technique uses microwave energy and hydrogen peroxide. Dendrites and perikarya of cortical pyramidal neurons and large subcortical multipolar neurons are the neuronal structures most commonly impregnated by this method.

Animals↗
PubMed1985

The effects of dichloromethylene biphosphonate on osteoporotic femora of adult castrate male rats.

In a previous study we reported that castration of adult male rats resulted in femoral osteoporosis 4 months later. The present study tested the effects of dichloromethylene biphosphonate (Cl2MBP, formerly Cl2MDP), a bone resorption inhibitor, on the development of osteoporosis in femora of adult castrated male rats. One-year-old male Holtzman rats were assigned to three groups: sham-operated controls; castrated-no treatment; castrated + Cl2MBP injections 3 times/week. The animals were sacrificed 4 months later. Femora from untreated castrated rats were osteoporotic, confirming our earlier study. Femora from Cl2MBP-treated castrates did not differ from those of controls and were significantly denser and more robust than those of untreated castrated rats. The results indicated that Cl2MBP treatment started immediately after castration prevented the development of femoral osteoporosis in adult castrated male rats.

Animals↗
PubMed1984

Comminuted femoral-shaft fractures: treatment by roller traction, cerclage wires and an intramedullary nail, or an interlocking intramedullary nail.

In a retrospective study, we attempted to assess progress in the treatment of comminuted fractures of the femoral shaft at Parkland Memorial Hospital from 1978 to 1983. Seventy-nine comminuted femoral-shaft fractures were available for follow-up: thirty-two treated by roller traction, twenty-three treated by cerclage wires and an intramedullary nail, and twenty-four treated by an interlocking intramedullary nail. Using the classification of Winquist and Hansen, Grade-III and IV comminuted fractures accounted for 69 per cent of those treated by roller traction, 68 per cent of those treated by nailing and cerclage wires, and 96 per cent of those treated by an interlocking nail. The frequency of multiple injuries was 38 per cent in the patients treated by roller traction, 39 per cent in those treated by nailing and cerclage wires, and 58 per cent in those treated by an interlocking nail. The average hospitalization times were thirty-one days for roller traction, sixteen days for cerclage wires and an intramedullary nail, and 19.5 days for an interlocking nail. The average length of follow-up was 132 weeks after roller traction, 115 weeks after cerclage wiring and an intramedullary nail, and sixty weeks after insertion of an interlocking nail. All fractures were followed until after union; the average times to union were 18.4 weeks after roller traction, thirty-four weeks after open reduction and intramedullary nailing with cerclage wires, and 13.8 weeks after insertion of an interlocking nail. For the purposes of this study, treatment was assumed to have failed if a change in treatment was necessary, an unplanned reoperation was performed, femoral shortening exceeded 2.5 centimeters, angulation was more than 15 degrees, non-union or a deep infection developed, motion of the knee was less than 70 degrees of flexion, or a refracture occurred. By these criteria, the frequency of failure after roller traction was 66 per cent (secondary to malalignment and shortening); after insertion of an intramedullary nail with cerclage wires, 39 per cent (secondary to unplanned surgery, non-union, shortening, and infection); and after use of an interlocking nail, 4 per cent (secondary to shortening). Currently, at our institution, an interlocking intramedullary nail is the treatment of choice for comminuted femoral-shaft fractures because it encourages early union with maintenance of length and alignment and the results are predictable.

Adolescent↗
PubMed1983

Persistent infection of some standard cell lines by lymphocytic choriomeningitis virus: transmission of infection by an intracellular agent.

Cell-free cytoplasmic extracts of the Syrian hamster cell lines C13/SV28 and BHK-21F were immunogenic in Syrian hamsters. The resulting antisera cross-reacted completely with antisera against lymphocytic choriomeningitis virus (LCMV) in an immunoradiometric assay employing BHK-21F antigen. Several other Syrian hamster cell lines not previously known to be infected with LCMV were also strongly positive when assayed for viral antigens. Also, several mouse sera and antisera raised in Syrian hamsters against cells transformed by papovaviruses had high titers of anti-LCMV activity. No cytopathic effect was evident in any of the persistently infected cell lines. Culture media from these cells were not infectious and showed no evidence of defective interfering particles. However, cell-free extracts of all the persistently infected cells contained material capable of transmitting the persistent infection to uninfected cells of Syrian hamsters, rats, mice, green monkeys, and humans. The onset of infection is much slower than when LCMV virions are used. When 2 X 10(6) uninfected BHK cells were treated with an extract from 100 persistently infected cells, the new infection was apparent within about 12 days. When an extract from 10(6) cells was used, the new infection was apparent within about 5 days, but not sooner. The intracellular infectious material was sensitive to treatment with deoxycholate, Nonidet P-40, or ether but resistant to treatment with RNase or trypsin. It was also large (5,000S) and heterodisperse on sucrose gradients. The infectious material was probably contained in large lipid vesicles and their integrity was probably essential for infection. When a few persistently infected cells were cocultivated with many uninfected cells, a few discrete colonies positive for LCMV antigens were observed after about 5 days. Since the culture media were not infectious, the infection probably spread by cell-cell contact. Several different experiments indicated that interferon did not play a major role in mediating persistence in this case. Persistent infections by LCMV can be maintained without expression of extracellular virus particles and without appearance of large amounts of viral antigens on the cell surface. Cell-cell contact could still allow transmission of intracellular infectious material. In an animal, these properties could circumvent immune surveillance.

Animals↗
PubMed1982

[True orientation of the acetabulum as determined by CAT scan. Preliminary results (author's transl)].

Valid clinical correlations with biomechanical data require three-dimensional visualization of a joint, in order to determine the true spatial configuration of the various segments of the part studied. The CAT scan has opened a new pathway in this direction, as it supplies precise mathematical information on the segments explored. An original analytical programme was employed in humans to establish the true spatial orientation of the acetabular cavity. The validity of the method was confirmed by comparing results in 31 subjects with the rare cases where such measurements were made, reported in the published literature. The method could be extended to other body regions.

Acetabulum↗