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Biomedical subjects

W M Murphy

Publications and source records attributed to W M Murphy.

At least 19 recordsLinked to original sources
PubMed1995

Clinical and experimental bone changes after intraosseous implantation.

Long-term prosthodontic rehabilitation has been extensively documented with the use of osseointegrated biocompatible materials in the mandible and maxilla with resultant improvements in quality of life for patients. In addition, clinical evidence is accumulating to show that mandibular atrophy may slow and even be reversed after implantation. Increased bone height and density have been reported: a finding not unexpected in the light of Wolff's law, which is a universal response of bone to increased functional loads.

Animals↗
PubMed1994

Carcinoma in situ of the urinary bladder. Clues to host involvement in human carcinogenesis.

BACKGROUND: Carcinoma in situ (CIS) of the urinary bladder is a neoplasm of uncertain biologic behavior. It rarely occurs as the primary disease and exists most often in association with high grade, invasive tumors. The unfavorable prognosis ascribed to CIS may not be due to tumor-related factors but to low host resistance or to host-tumor relationships established for previous or co-incident invasive cancers. The scant available evidence indicates that a large proportion of patients with primary CIS have a low frequency of muscle invasion and death from disease. METHODS: Of 2000 patients with bladder neoplasms in our pathology files and tumor registry, 102 had CIS confirmed on histologic review. There were 29 cases of primary CIS and 73 cases of secondary CIS. These cases were compared, with an emphasis on patient outcome. RESULTS: The data indicate that primary and secondary CIS are histologically identical lesions whose effect on patients is related mainly to the presence of multifocal disease, often associated with previous or coincident invasive cancers. Progression or death from disease is unusual among patients presenting with primary CIS but common among individuals with CIS associated with other bladder cancers. CONCLUSION: The authors suggest that the appearance of urothelial CIS identifies patients with at least localized resistance to the development of invasive bladder cancer. The degree of patient resistance to carcinogenic events leading to bladder carcinoma is manifested by the type, grade, and stage of their initial neoplasms.

Adult↗
PubMed1994

Androgen deprivation prior to radical prostatectomy for T2b and T3 prostate cancer.

OBJECTIVE: In an effort to improve on the results of radical prostatectomy for clinical stages T2b and T3 prostate cancer, a selected group of patients received androgen deprivation for three to sixteen months prior to surgery. METHODS: Fifteen men with clinical T2b and 22 with small T3 tumors received a luteinizing hormone-releasing hormone analog (n = 34) or a bilateral orchiectomy (n = 3) three to sixteen months prior to radical retropubic prostatectomy. The prostate was evaluated with particular attention to tumor grade, presence of extracapsular extension, tumor at the inked margin, seminal vesicle invasion, and tumor in the lymph nodes. RESULTS: No patient had clinical or chemical (prostate-specific antigen [PSA]) progression during androgen deprivation. The PSA level declined a mean 90 percent and remained above 4 ng/mL in only two patients. The prostate volume decreased an estimated 30-50 percent. Prostate cancer at the inked margin was found in 15 (41%) and seminal vesicle involvement in 11 (30%) patients. Five (14%) had tumor in regional lymph nodes. There was no difference in regard to positive margins or lymph node metastases between those clinically staged as T2b and those preoperatively staged as T3. Fourteen patients have received adjuvant therapy (13 androgen deprivation, one radiation therapy). None has progressed (mean follow-up, 38.4 months). Of 23 who did not receive immediate additional therapy, six (26%) had progression, as was evident from an increase in PSA and have since been treated. Only one continued to progress. Thirty-five of the 37 patients are alive. Seventeen (46%) are tumor free (PSA < 0.4 ng/mL) without further androgen deprivation. CONCLUSIONS: Only a prospective randomized trial can determine whether androgen deprivation prior to radical prostatectomy has a role. The results from this trial are encouraging for several reasons. The prostate is much smaller as a result of androgen deprivation and this may facilitate surgery. Although the great majority of these patients were expected to be margin positive, 60 percent had negative margins and only 14 percent had positive lymph nodes.

Combined Modality Therapy↗
PubMed1994

ASCP survey on anatomic pathology examination of the urinary bladder.

The American Society of Clinical Pathology Quality Management Practice Review Committee is sponsoring publication of a series of articles commenting on procedures used by pathologists during the examination of various surgical specimens. Committee-sponsored survey results serve as the basis for discussion and commentary by an expert in the field. Although this information may prove useful in forming a practice parameter, it is not the intention of the author or the committee to identify this information as a practice parameter. The publication of this article does not necessarily represent the opinions or endorsement by the ASCP Board of Directors.

Biopsy↗
PubMed1992

Bond strength and rupture properties of some soft denture liners.

The bond strength and rupture properties of three soft acrylic liners (Coe-Soft, Coe Super-Soft and Vertex Soft) and two silicone liners (Molloplast-B and Flexibase) were tested immediately after processing and following immersion in water at 37 degrees C for 7 and 90 days. The bond test gave variable results, as some materials partly peeled and then stretched until rupture occurred. After saturation the acrylic liners exhibited an increase in tear resistance, whilst silicone materials deteriorated, in the case of Flexibase to approximately 25% of its original value. Vertex Soft was the exception, as tear resistance decreased as water sorption increased. Scanning electron microscopy revealed indefinite demarcation between soft acrylic resins and hard denture base, which was not altered after saturation in water. On the other hand, the interface between denture base and silicone liners was clearly visible before and after saturation. The results indicated that denture soft liners had variable water sorption values depending on their basic structure, and some properties changed after immersion in water, a finding that is of relevance to prosthodontic practice.

Acrylic Resins↗
PubMed1992

Experience with the Astra dental implant system.

The Astra Dental Implant System appears to be a relatively successful and economical method of osseointegration. This article lists its clinical components, explains how the system is fitted and discusses the preliminary results.

Aged↗
PubMed1992

Urothelial neoplasia.

Urothelial neoplasia is a complex subject that can be only partially understood by careful study of the light microscopic features of individual lesions. Despite decades of study, our knowledge concerning the interaction of neoplastic events and host responses remains rudimentary. Most information has been collected by observing cases (usually in retrospect) that have been grouped according to relatively arbitrary criteria based on the phenotypic appearances of lesions as they are viewed through the light microscope. When evaluating human disease, we are always forced to reason backwards to determine the most likely histogenesis and to project forward to assess the most likely prognosis. Both types of reasoning must be filled with conjecture since direct observations from the initial events to the end results are not possible. Under these constricting circumstances, a conceptual framework into which our often anecdotal observations can be placed is more important than we would like to admit. With this in mind, I have taken advantage of the monograph format to risk a speculative approach to the subject, at least as it applies to the significance of the pathological features. In the past, we have accepted the view that all human hosts are essentially the same and that variations in cancer type and behavior are related almost entirely to the genetic ingenuity of the cancer cells themselves. Perhaps we should now entertain the opposite view, that carcinogenic events are ubiquitous and that cancer in any individual patient represents only what that patient will allow to grow in his or her body. We have devoted almost all of our collective research energy to examining the tumor. I believe that the pace of future progress can be significantly increased if we can think of more ways to examine the patient.

Adenocarcinoma↗
PubMed1992

The nested variant of transitional cell carcinoma: a neoplasm resembling proliferation of Brunn's nests.

This report describes four cases in which a malignant transitional cell neoplasm initially manifested as small nests and abortive tubules infiltrating the lamina propria. Many of the tumor cells were only slightly atypical but careful examination revealed at least some significantly anaplastic cells in every case, the degree of cellular atypia tending to parallel the depth of invasion. Despite the initial impression of a benign lesion resembling a proliferation of Brunn's nests, these carcinomas tended to be persistent and aggressive.

Aged↗
PubMed1991

Pathologic changes associated with androgen deprivation therapy for prostate cancer.

Prostate glands exposed to androgen deprivation with leuprolide +/- flutamide were evaluated for pathologic changes which might be related to therapy. Comparing pretreatment and posttreatment tissue by visual discrimination using light microscopic study revealed treatment-related alterations in the size and distribution of neoplastic glands in 60% of cases. Quantitative measurements documented glandular changes in an even greater percentage of cases. Although distinctive, the histologic pattern was not specific for leuprolide/flutamide. The absence of appreciable degeneration and necrosis in tumor cells suggests that this type of androgen deprivation may act through suppression rather than ablation of prostatic cancers. The relationship between treatment-related histologic effects and initial tumor grade and clinical stage as well as expression of prostate-specific antigen was studied. Accurate histologic assessment of leuprolide/flutamide-treated prostate glands should not be a problem so long as specimens are thoroughly examined and drug-related variations in tumor morphologic features are appreciated.

Aged↗
PubMed1990

Complete denture construction in general dental practice: an update of the 1970 survey.

A survey was carried out on materials and techniques used for complete denture construction in general dental practice, by means of a postal questionnaire sent to a random sample of 1000 dentists whose names were taken from the BDA membership. There was a 71.5% response. The results obtained are compared with a similar survey undertaken in 1970. The majority of practitioners still provided dentures totally or mainly within the NHS. Whilst the demand for complete dentures was reported as having remained stable, there has been considerable reduction in the numbers of dental technicians employed by general dental practitioners. Alginate remains the impression material of choice and the majority of impressions were sent to a commercial laboratory for pouring. Although still the most popular, the use of the plane-line hinge articulator has reduced and there has also been a continued reduction in the use of porcelain teeth. The importance of a cross-infection policy is highlighted. There were conflicting opinions expressed on the role of implants in general dental practice. Many respondents took the opportunity to comment on the status of dental prosthetics under the NHS and most criticised the fee structure.

Acquired Immunodeficiency Syndrome↗
PubMed1990

A clinical study of the Brånemark dental implant system.

A clinical study using the Brånemark dental implant system was carried out on 13 patients aged 41 to 68 years. Clinical and psychological effects of treatment were assessed at 6-monthly intervals over a period of 3 years by means of a clinical examination, a personality assessment using Cattell's 16 PF Questionnaire and a general subjective questionnaire. Six per cent of implants failed to osseointegrate. Fifty per cent of bridges became loose, but remained stable after retightening. A similar percentage of fractures occurred, mainly teeth separating from acrylic gumwork. There was some soreness of peri-implant mucosa, particularly on cleaning. Despite these problems, there was considerable evidence of improved well-being of patients, who felt more secure following treatment and, as a result, their personal and social relationships improved.

Adult↗
PubMed1990

Current status of urinary cytology in the evaluation of bladder neoplasms.

Pathologic examination of urinary specimens is increasingly recognized as an essential component of detection and monitoring for patients with bladder neoplasms. Among the available techniques, urinary cytology is the most useful. The current status of urinary cytology can be summarized as follows: 1. The demand for urinary cytology is steadily increasing as clinicians have realized the limitations of cystoscopy and even biopsy for monitoring bladder cancer patients, especially those having carcinoma in situ or receiving topical therapy. 2. Urinary cytology is currently an essential procedure for monitoring all patients with urothelial neoplasms and, if consistently used, can actually decrease the frequency with which patients need to be subjected to cystoscopy. 3. Even in moderately experienced hands, urinary cytology can detect almost all high-grade urothelial neoplasms. 4. The cytologic interpretation of low-grade transitional cell neoplasia requires expertise. These cells lack many of the features of malignancy, a source of confusion for the diagnostician but a positive factor for the patient since neoplasms composed of these cells are almost never aggressive. 5. The most useful type of urinary specimen for routine diagnostic interpretation is freshly voided, randomly collected urine. Catheterized specimens and bladder washings may yield more and better preserved cells, but no patient should be catheterized solely to obtain diagnostic material. 6. Preservation of urinary specimens in alcohols is not necessary unless prolonged storage is contemplated. Refrigeration to prevent bacterial growth and inhibit further cellular degeneration is required, however. 7. Cytologic details are best displayed with membrane filtration but other types of processing are adequate. The computer-programmed cytocentrifuge is currently most popular. 8. Optimal recognition of cytologic details requires some form of Papanicolaou staining; Romanovsky dyes are less desirable. 9. Urothelial cells with nuclear:cytoplasmic ratios of 1:2 or less should not be interpreted as malignant regardless of the degree of anaplasia of their nuclei. 10. Papillary aggregation is not a reliable feature of low-grade neoplasia in urinary samples. 11. Using appropriate criteria, the differential diagnosis of urothelial neoplasia versus the reactive/regenerative/reparative changes secondary to urinary stones can almost always be accomplished. 12. Alkylating agents such as Cytoxan, thio-TEPA, and mitomycin C produce characteristic but nonspecific changes in urothelial cells. These changes rarely mimic those of carcinoma. The diagnosis of urothelial neoplasia need not be confounded by previous treatment. 13. Flow cytometry and digitized image analysis are currently used for diagnostic interpretations of urinary specimens in selected centers. Their routine use must await further refinements in instrumentation and the formulation of more searching questions.

Cytodiagnosis↗
PubMed1990

Finite element analysis of fixed prostheses attached to osseointegrated implants.

The effect of defined stresses on cantilevered prostheses attached to osseointegrated implants was assessed by finite element analysis. The effect of stress on a cantilever, consisting of a ductile alloy in contact with a brittle polymer, was demonstrated to be complex. The distribution of applied stresses also influenced the results. Possible fracture and distortion of both materials were demonstrated. Finite element analysis is a particularly useful system for predicting stress behavior and can be employed to produce an optimal prosthetic design that reduces the potential for clinical failure.

Acrylic Resins↗
PubMed1989

Effect of water and artificial saliva on mechanical properties of some denture-base materials.

Two artificial saliva samples selected on the basis of being chemically and physically similar to natural saliva were used as saturation media so that we could investigate their effects on mechanical properties of four denture-base materials, and the results were compared with the effect of water on the same materials. Diffusion coefficients in the more viscous saliva were different from those in water but, in general, mechanical properties were similarly affected in all liquids, indicating that the aqueous phase of the artificial medium was a major factor influencing the results.

Acrylic Resins↗