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Biomedical subjects

J E Conway

Publications and source records attributed to J E Conway.

7 recordsLinked to original sources

High-titer recombinant adeno-associated virus production utilizing a recombinant herpes simplex virus type I vector expressing AAV-2 Rep and Cap.

Recombinant adeno-associated virus type 2 (rAAV) vectors have recently been used to achieve long-term, high level transduction in vivo. Further development of rAAV vectors for clinical use requires significant technological improvements in large-scale vector production. In order to facilitate the production of rAAV vectors, a recombinant herpes simplex virus type I vector (rHSV-1) which does not produce ICP27, has been engineered to express the AAV-2 rep and cap genes. The optimal dose of this vector, d27.1-rc, for AAV production has been determined and results in a yield of 380 expression units (EU) of AAV-GFP produced from 293 cells following transfection with AAV-GFP plasmid DNA. In addition, d27.1-rc was also efficient at producing rAAV from cell lines that have an integrated AAV-GFP provirus. Up to 480 EU/cell of AAV-GFP could be produced from the cell line GFP-92, a proviral, 293 derived cell line. Effective amplification of rAAV vectors introduced into 293 cells by infection was also demonstrated. Passage of rAAV with d27. 1-rc results in up to 200-fold amplification of AAV-GFP with each passage after coinfection of the vectors. Efficient, large-scale production (>109 cells) of AAV-GFP from a proviral cell line was also achieved and these stocks were free of replication-competent AAV. The described rHSV-1 vector provides a novel, simple and flexible way to introduce the AAV-2 rep and cap genes and helper virus functions required to produce high-titer rAAV preparations from any rAAV proviral construct. The efficiency and potential for scalable delivery of d27.1-rc to producer cell cultures should facilitate the production of sufficient quantities of rAAV vectors for clinical application.

Blotting, Western

Marfan syndrome is not associated with intracranial aneurysms.

BACKGROUND AND PURPOSE: It has been proposed that patients with Marfan syndrome have an increased prevalence of intracranial aneurysms. This proposition is based on 10 clinical reports, 1 pathology case, and an autopsy series of 7 patients. By contrast, 5 clinical series of Marfan patients have failed to document any such relationship. We present our institution's autopsy and clinical experience with Marfan syndrome and analyze in our patient population the purported association between this condition and intracranial aneurysms. METHODS: The results of an autopsy series at the Johns Hopkins Hospital of 25 confirmed Marfan syndrome patients from 1939 to the present were reviewed retrospectively. The prevalence of intracranial aneurysms in this Marfan syndrome autopsy series was compared with that in the autopsy population at this institution and with that in the general autopsy population as reported in the literature. In addition, the prevalence of Marfan syndrome in a recent neurosurgical series of 710 consecutive aneurysm cases (1990-1998) was determined. RESULTS: Of the 25 autopsy cases, only 1 had evidence on autopsy of an unruptured, 2-mm aneurysmal dilatation at the anterior communicating artery complex. Three autopsy patients suffered intracranial hemorrhages but had negative angiography and postmortem examinations for intracranial aneurysms. The remaining 21 patients had negative autopsies for intracranial hemorrhages or intracranial aneurysms. The neurosurgical series of 710 patients treated for intracranial aneurysms did not include any patient with Marfan syndrome. CONCLUSIONS: The prevalence of 1 patient of 25 with an intracranial aneurysm is not statistically different from the 1.3% prevalence of intracranial aneurysms in the autopsy population at this institution (P=0.24) or from the 2.0% prevalence of intracranial aneurysms in the general autopsy population (P=0.31). We therefore conclude that there exists no evidence that Marfan syndrome is associated with an increased prevalence of intracranial aneurysms.

Adolescent

Evolution of the species 'expert nurse'. An examination of the practical knowledge held by expert nurses.

The aim of this study was to examine the knowledge that expert nurses use in practice and the factors that influence knowledge use and development. A combined ethnographic and phenomenological methodology was used. Data were collected by questionnaires, interviews, workshops, observation visits and critical incident technique. Knowledge and expertise were found to have developed in response to the 'world view' held by expert nurses. Four distinct types of experts holding different knowledge bases emerged from the data.

Attitude of Health Personnel

Recombinant adeno-associated virus type 2 replication and packaging is entirely supported by a herpes simplex virus type 1 amplicon expressing Rep and Cap.

Recombinant adeno-associated virus (AAV) type 2 (rAAV) vectors have recently been shown to have great utility as gene transfer agents both in vitro and in vivo. One of the problems associated with the use of rAAV vectors has been the difficulty of large-scale vector production. Low-efficiency plasmid transfection of the rAAV vector and complementing AAV type 2 (AAV-2) functions (rep and cap) followed by superinfection with adenovirus has been the standard approach to rAAV production. The objectives of this study were to demonstrate the ability of a recombinant herpes simplex virus type 1 (HSV-1) amplicon expressing AAV-2 Rep and Cap to support replication and packaging of rAAV vectors. HSV-1 amplicon vectors were constructed which contain the AAV-2 rep and cap genes under control of their native promoters (p5, p19, and p40). An HSV-1 amplicon vector, HSV-RC/KOS or HSV-RC/d27, was generated by supplying helper functions with either wild-type HSV-1 (KOS strain) or the ICP27-deleted mutant of HSV-1, d27-1, respectively. Replication of the amplicon stocks is not inhibited by the presence of AAV-2 Rep proteins, which highlights important differences between HSV-1 and adenovirus replication and the mechanism of providing helper function for productive AAV infection. Coinfection of rAAV and HSV-RC/KOS resulted in the replication and amplification of rAAV genomes. Similarly, rescue and replication of rAAV genomes occurred when rAAV vector plasmids were transfected into cells followed by HSV-RC/KOS infection and when two rAAV proviral cell lines were infected with HSV-RC/KOS or HSV-RC/d27. Production of infectious rAAV by rescue from two rAAV proviral cell lines has also been achieved with HSV-RC/KOS and HSV-RC/d27. The particle titer of rAAV produced with HSV-RC/d27 is equal to that achieved by supplying rep and cap by transfection followed by adenovirus superinfection. Importantly, no detectable wild-type AAV-2 is generated with this approach. These results demonstrate that an HSV-1 amplicon expressing the AAV-2 genes rep and cap along with HSV-1 helper functions supports the replication and packaging of rAAV vectors in a scaleable process.

Cloning, Molecular

A monkey could do your job!

The present ethos in the health service of cost effectiveness and quality assurance requires nurses to identify the value of nursing practice in a way previously unheard of. Questions arise from this in relation to nursing and the nature of nursing. Some managers I have discussed these issues with believe that nurses are not required in theatre. It is not really surprising that such beliefs abound. Nurses have traditionally been more preoccupied with getting the work done than analysing the value of the nursing role. Much of this role is practical and there has, in the past, been little written about the nature of practical nursing let alone specifically about the practice of theatre nurses. Benner's work, with its emphasis on practice and recognition of nursing expertise, has brought about a reconceptualisation of the value of practice and of the knowledge found in that practice. In addition, the whole area of practical knowledge and expertise is now benefiting from further exploration.

Clinical Competence

Medial instability of the elbow in throwing athletes. Treatment by repair or reconstruction of the ulnar collateral ligament.

From September 1974 to December 1987, seventy-one patients were operated on for valgus instability of the elbow. The average length of follow-up of sixty-eight patients (seventy operations) was 6.3 years (range, two to fifteen years). At the operation, a torn or incompetent ulnar collateral ligament was found. Fourteen patients had a direct repair of the ligament, and fifty-six had a reconstruction of the ligament using a free tendon graft. The result was excellent or good in ten patients in the repair group and in forty-five (80 per cent) in the reconstruction group. Seven of the fourteen patients who had a direct repair returned to the previous level of participation in their sport. Of the fifty-six who had a reconstruction, thirty-eight (68 per cent) returned to the previous level of participation. Twelve of the sixteen major-league baseball players who had a reconstruction as the primary operation (no previous operation on the elbow) were able to return to playing major-league baseball, and two of the seven major-league players who had a direct repair returned to playing major-league baseball. Previous operations on the elbow decreased the chance of returning to the previous level of sports participation (p = 0.04). Fifteen patients had postoperative ulnar neuropathy. This was transient in six patients, only one of whom was unable to return to the previous level of sport. The other nine patients had an additional operation for the neuropathy; four were able to return to the previous level of sport.

Adult