Biomedical subjects

R B Evans

Publications and source records attributed to R B Evans.

At least 37 records · Page 2Linked to original sources

PubMed1995

Joseph Delboeuf on visual illusions: a historical sketch.

The Delboeuf illusion consists in a change in the perceived (judged) size of one circle in the presence of another concentric circle. This illusion was presented and analyzed for the first time in 1865 and not, as stated by numerous investigators, in 1892 or 1893. This misconception reflects profound misreadings of Delboeuf's works. The present study examines the three Delboeuf articles on visual illusions (1865a, 1865b, 1892) and analyzes the author's data in the light of results obtained to date on concentric circle illusions.

France↗

PubMed1994

Early active short arc motion for the repaired central slip.

This study compared the functional results in patients with open and repaired central slip injuries treated by two different postoperative management methods. The groups were similar in number of patients and amount of complex injuries. The comparisons made were proximal interphalangeal joint extensor lag, flexion at distal interphalangeal and proximal interphalangeal joints, total active motion, and length of treatment required. Patients in group 1 were treated with 3-6 weeks of continuous immobilization followed by a vigorous standard rehabilitation program. Patients in group 2 were treated by early active short arc motion initiated between the second day and the eleventh day after repair. By all criteria evaluated, patients in group 2 demonstrated better results at discharge compared to patients in group 1.

Adult↗

PubMed1994

Bcl-2 inhibits glucocorticoid-induced apoptosis but only partially blocks calcium ionophore or cycloheximide-regulated apoptosis in S49 cells.

Many non-Hodgkins B-cell lymphomas possess a deregulated bcl-2 gene resulting in a phenotype that is apparently resistant to programmed cell death (apoptosis). We have used a mouse lymphoma cell line (S49.1) that undergoes apoptosis in response to a variety of stimuli to determine the effect of bcl-2 expression on induction of apoptosis. S49 cells were stably transfected with recombinant amphotrophic retroviruses carrying either a G418 antibiotic resistance gene alone (S49-NEO) or this gene in combination with a bcl-2 complementary DNA (S49-Bcl-2). Three different agents previously shown to activate apoptosis by different pathways in S49 cells (dexamethasone, the calcium ionophore A23187, and cycloheximide) were used to examine the effect of bcl-2 expression on cell growth and apoptosis caused by multiple signal transduction pathways. Dexamethasone (DEX) treatment inhibited cell growth and stimulated cell death in S49-NEO cells. Although S49-Bcl-2 cells exhibited a similar antiproliferative response, they failed to die in response to steroid treatment. Western blot analysis revealed no difference in the levels of glucocorticoid receptor protein in the two cell lines, and both responded to glucocorticoid with a profound inhibition of protein synthesis. Cycloheximide (CX) and A23187 also had antiproliferative and cell killing effects in both cell types, although higher concentrations of each agent were needed to kill S49-Bcl-2 cells. To determine whether the loss of viability in response to these drugs was due to apoptosis, cells were examined morphologically and DNA integrity was examined by gel electrophoresis.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1994

Sensory discrimination and intelligence: postmortem or resurrection?

This historical review addresses the following problem: If researchers at the start of the twentieth century failed to find associations between intelligence and the senses, why do present-day researchers report significant associations between sensory discrimination and IQ-type test scores? The studies most between sensory discrimination and IQ-type test scores? The studies most often referred to as having failed to link intelligence differences to differences in sensory discrimination were conducted by Galton (1883), Sharp (1898-1899), and Wissler (1901). It is shown that these studies are often reported inaccurately and that they have deficiencies that make them almost worthless for empirical evaluation. Other, less frequently cited studies conducted about the same time consistently reported modest and significant associations between sensory discrimination and estimates of mental ability which concur with more recent research. The widely held current view about the failure of historical attempts to relate intelligence to the senses is incorrect because it is based upon inaccurate reports of a few poorly conducted negative studies and the omission of positive findings from other research.

Discrimination, Psychological↗

PubMed1993

Diagnostic testing for prostate cancer detection: less is best.

The incidence of clinically organ-confined prostate cancer has markedly improved in programs designed to detect this disease by utilizing a combination of diagnostic modalities including digital rectal examination (DRE), transrectal ultrasonography (TRUS), and prostate-specific antigen (PSA). Biopsies were performed on 436 men who had abnormal findings on DRE, TRUS, or PSA. Overall, 39 percent of these men had histologic confirmation of prostate cancer. TRUS diagnosed more cancer (94%) than either DRE (80%) or PSA (89%), while the combination of TRUS and PSA diagnosed a similar number of cancers as the combination of DRE and PSA (100% vs 98%). The positive predictive value (PPV) of DRE and PSA combination was significantly better than that of TRUS and PSA (p = 0.01), but was not different from that of a combination of all three tests. DRE and PSA would have missed 4 cancers, but would have cost approximately 140 percent less than any program employing TRUS. Consequently, we recommend that the combination of DRE and PSA be used in primary early detection for prostate cancer and that TRUS be performed only when either or both DRE and PSA results are abnormal.

Costs and Cost Analysis↗

PubMed1993

Identification of a rel-related protein in the nucleus during the S phase of the cell cycle.

The c-rel proto-oncogene encodes a 75-kDa protein (p75c-rel) which is present in the cytosol of chick embryo fibroblasts (CEF) associated with a distinct set of cellular proteins with molecular masses of 40, 115, and 124 kDa. CEF cultures arrested in S phase of the cell cycle, or enriched for G2 or mitotic cells, were examined to determine whether the expression of c-rel was altered during the cell cycle. Levels of p75c-rel remained constant in all portions of the cell cycle examined; however, a Rel-related protein with an apparent molecular mass of 64 kDa was detected in nuclei of S-phase cells. As cells enter G2, the level of this protein in the nucleus decreases. This protein reacts with antiserum generated against the carboxy terminus of p75c-rel in radioimmunoprecipitations and Western immunoblot experiments and was also detected in a Western immunoblot with antiserum generated against the first 161 amino acids of pp59v-rel. Thus, unlike other Rel/NF-kappa B family members, p64 has carboxy-terminal homology with c-Rel. The majority of peptides generated by partial proteolytic cleavage of p64 are shared with peptides generated by digestion of p75c-rel and/or pp59v-rel. We suggest that this protein represents a new member of the Rel family of transcription factors and is located in the nucleus of avian fibroblasts during S phase of the cell cycle.

Amino Acid Sequence↗

PubMed1992

The distribution of prostate specific antigen in men without clinical or pathological evidence of prostate cancer: relationship to gland volume and age.

We estimated the in vivo prostate gland volume in 408 men (320 without clinical evidence of prostate cancer, and 88 with an abnormal digital rectal examination and/or transrectal prostate ultrasound and negative biopsies) using sequential step-section ultrasound analysis and correlated it to the serum prostate specific antigen (PSA) value. Of the men 331 (81.1%) had a PSA value of 4 ng./ml. or less. The PSA value was greater than 4 but less than or equal to 10 in 64 men (15.7%) and greater than 10 in 13 (3.2%). The men were subclassified by prostate gland volume at arbitrary break points. A total of 139 men (34.1%) had a gland of 25 cm.3 or less, 2.2% of whom had a PSA value of greater than 4. Further analysis revealed that the incidence of a PSA value greater than 4 increased as the prostate volume increased (18.4% for greater than 25 but less than or equal to 50, and 65.4% for greater than 50) and as age increased. We found a statistically significant association between prostate gland volume and patient age (p less than 0.00005) to the serum PSA concentration. The finding of a PSA value of greater than 10 was uncommon regardless of the prostate gland volume. Clinical implications of these results are discussed, and a statistical model to estimate the serum PSA by gland volume and patient age was constructed.

Adult↗

PubMed1991

Early detection program for prostate cancer: results and identification of high-risk patient population.

Three hundred sixty-two men underwent transrectal ultrasound of the prostate (TRUS), digital rectal examination (DRE), and serum prostate-specific antigen (PSA) determination as part of an early detection program for prostate cancer. Thirty-seven (10%) cancers were detected. DRE had the highest sensitivity and specificity, 89 percent and 84 percent, respectively. TRUS and PSA had comparable sensitivities (84% and 81%) and specificities (82% and 82%). The positive predictive values of DRE, TRUS, and PSA determination were 39 percent, 35 percent, and 33 percent, respectively. We found a cancer detection rate of 16 percent among patients with symptoms of bladder outlet obstruction and 5 percent in patients without these symptoms. The detection rate was 36 percent for physician-referred patients and 3 percent for self-referred patients. This suggests to us that at the present time the best utilization of medical resources to increase prostate cancer detection is to educate men to have annual medical evaluations by primary-care physicians who are encouraged to incorporate risk assessment and screening DRE as part of their routine practice. Any man with either abnormal findings on examination or increased risk should be referred to a urologist for further evaluation.

Antigens, Neoplasm↗

PubMed1991

Thallium-201 scintigraphy after intravenous infusion of adenosine compared with exercise thallium testing in the diagnosis of coronary artery disease.

Adenosine is an endogenously produced compound that has significant effects as a coronary and systemic vasodilator. Previous studies suggest that intravenous infusion of adenosine, coupled with thallium-201 scintigraphy, may have specific value as a noninvasive means of evaluating coronary artery disease. The purpose of this study was to compare the diagnostic value of adenosine thallium testing with that of standard exercise thallium testing. One hundred subjects were studied with exercise thallium imaging and thallium imaging after adenosine infusion, including 47 with angiographically proved coronary artery disease and 53 control subjects. The overall sensitivity of the thallium procedures was 81% for the exercise study and 83% for the adenosine study (p = NS); the specificity was 74% for the exercise study and 75% for the adenosine study (p = NS). The diagnostic accuracy of the exercise study was 77% and that of the adenosine study was 79%. Ninety-four percent of subjects had an adverse effect due to the adenosine infusion; however, most of these effects were mild and well tolerated. All adverse effects abated within 30 to 45 s of the termination of the study, consistent with the very brief half-life of the agent. Thus, thallium-201 scintigraphy after intravenous infusion of adenosine has a diagnostic value similar to that of exercise thallium testing for evaluation of coronary artery disease. Adenosine thallium testing may be particularly useful in evaluating patients unable to perform treadmill exercise testing.

Adenosine↗

PubMed1991

An update on wound management.

This article provides an update on wound management with wound diagnosis and treatment discussed in terms of the normal cellular events of the wound healing process. The role of growth factors as cell regulators, the importance of wound fluids to wound metabolism, and the deleterious effects of some wound cleansers, disinfectants, and modalities are reviewed. Treatment guidelines are suggested based on negative or positive cellular response to individual management techniques. Wound evaluation, diagnosis, and treatment are considered in terms of a new color concept that simplifies clinical decision making. An explanation of the relatively new microenvironmental dressings designed to maintain wound humidity and speed wound healing is provided. A more physiologic approach to managing the simple and complex wound may prove to speed the process of epithelialization, contraction, and collagen deposition while diminishing the problems associated with delayed or inadequate healing. The wound healing process is subject to manipulation and facilitation by the clinician, a concept that is certain to receive much attention in the next decade. The importance of a scientific approach to this aspect of our discipline cannot be overemphasized.

Hand Injuries↗

PubMed1990

Prostate-specific antigen and prostate gland volume: correlation and clinical application.

We studied 103 patients seen in our Prostate Cancer Detection Clinic to determine whether a correlation exists between serum prostate-specific antigen (PSA) values and ultrasound-calculated prostate gland volume. Seventy men (68%) had a PSA value less than or equal to 4 ng/ml (our upper limit of normal). The men were subclassified by prostate gland volume at arbitrary break points. Twenty-five men (24%) had a prostate gland volume less than or equal to 25 cm3; in 96%, the PSA value was less than or equal to 4 mg/ml. Further analysis revealed that the percentage of men with a normal serum PSA value decreased as the prostate gland volume increased; 65.6% of the group with a gland volume between 25 and 50 cm3 (40 of 61) and 35.5% of the group whose prostate volume exceeded 50 cm3 (6 of 17) had PSA values less than or equal to 4 ng/ml. Four men had PSA values greater than 20 ng/ml; all had prostate cancer. Cancer was diagnosed in four additional patients, three with PSA values between 5 and 10 ng/ml and one with a PSA value less than 4 ng/ml. There appears to be a direct relationship between prostate gland volume and PSA value, as well as a cancer value threshold. The clinical implications of these findings are discussed.

Adult↗

PubMed1990

Evaluation of ocular hypersensitivity to dipivalyl epinephrine by component eye-drop testing.

Dipivalyl epinephrine (dipivefrin) is a prodrug of epinephrine used for topical glaucoma therapy. Local side effects have been noted in approximately 20% of patients treated and include conjunctival hyperemia, foreign body sensation, and follicular conjunctivitis. We studied five patients with adverse local reactions to dipivefrin (Propine) eye drops. Propine contains the following: dipivefrin, 0.1%; mannitol, 1.89%; sodium metabisulfite, 0.075%; disodium edetate, 0.0127%; and benzalkonium chloride, 0.004%. Since the reactions could conceivably have been caused by an ingredient other than dipivefrin, we first patch tested the patients with the maximum recommended concentration of each ingredient. All patch tests were negative. Sterile ophthalmic solutions of each individual component at the concentrations used in the commercial product were then prepared. In a double-blinded study, the patients applied two drops of each preparation, twice daily for 1 week, with a 1-week, drug-free period between trials. Dipivefrin alone reproduced each patient's initial Propine-induced conjunctivitis; symptoms occurred unilaterally in one patient and bilaterally in the other four patients. This study indicates that testing with single component eye drops can identify the provocative component in ocular drug hypersensitivity and that these reactions can be unilateral.

Adult↗

PubMed1990

Peripheral anterior synechia overlying the haptics of posterior chamber lenses. Occurrence and natural history.

Sixty consecutive eyes that met the standard criteria for cataract surgery underwent phacoemulsification with insertion of a posterior chamber lens implant. The filtration angle of each eye was examined with routine postoperative gonioscopy in a prospective manner. Peripheral anterior synechia (PAS) overlying the position of the lens haptic (lens haptic PAS) were observed in up to 80% of eyes implanted with haptics vaulted anteriorly by 10 degrees. The rate of occurrence of lens haptic PAS was reduced by a statistically significant level in a group of eyes implanted with nonvaulted haptics. Most of the lens haptic PAS were observed early in the postoperative period and remained stable in size. Progression in size was noted quantitatively in three eyes and documented with goniophotography in two eyes. A delay in the presentation of lens haptic PAS was observed in seven eyes. A postoperative increase in intraocular pressure (IOP) associated with enlargement of lens haptic PAS developed in one patient with preoperative chronic open-angle glaucoma. These observations support others that progressive PAS overlying posterior chamber lens haptics can be a form of progressive angle-closure glaucoma in pseudophakia. This mechanism may be more likely to occur in eyes implanted with anterior vaulted haptics.

Aged↗

PubMed1989

Clinical application of controlled stress to the healing extensor tendon: a review of 112 cases.

The purposes of this article are to describe an early passive motion program for the healing extensor tendon and to report the results and trends noted in a review of 112 complex extensor tendon injuries treated with this therapeutic technique. The rationale for this technique is based on a review of the physiologic response of healing tendon to controlled stress. Clinical application is dependent on a biomechanical study of extensor tendon excursion, which allows the therapist to apply controlled stress to the healing tendon with precision. The early passive motion technique is considered in terms of physiology, biomechanics, clinical application, and results. The author concludes that early controlled passive motion for the complex extensor tendon injury in zones V, VI, VII, T IV, and TV is a safe and effective rehabilitation technique that reduces complications associated with extensor tendon injury and repair.

Biomechanical Phenomena↗

PubMed1987

Sexual rehabilitation in a cancer center: diagnosis and outcome in 384 consultations.

A program of sexual rehabilitation in a cancer center evaluated 308 men and 76 women, using a structured interview. The site of the malignancy was pelvic or genital in 79% of men and 58% of women. Most patients (73%) had one or two sessions of sexual counseling, but therapy was more intensive for about a quarter of patients. Partners were included in counseling by 28% of women and 56% of men. Although cancer patients and spouses of patients reported similar rates of sexual dysfunction before cancer diagnosis, after cancer treatment husbands and wives of patients maintained stable sexual function, while dysfunctions increased dramatically in all categories except premature ejaculation for patients. Patients who were older or had pelvic/genital tumors were more likely to develop arousal-phase sexual dysfunctions. Psychological distress was correlated with rates of low sexual desire and dyspareunia in both men and women. The success of treatment in reversing sexual dysfunction was rated by the therapist in 118 cases. Patients who were younger, who were not clinically depressed, and who had less conflicted marriages had more positive outcomes. Good outcome was also associated with a longer duration of treatment.

Adult↗

PubMed1987

Gold lung: recent developments in pathogenesis, diagnosis, and therapy.

Gold lung is a hypersensitivity pneumonitis to gold-containing compounds. It can be distinguished from rheumatoid lung by its subacute or acute onset, diffuse interstitial and/or alveolar filling pattern on chest roentgenogram, presence of lymphocytes on BAL with an inverse helper/suppressor ratio, and response to withdrawal of gold and/or corticosteroid therapy. Other in vitro assays of gold hypersensitivity using peripheral blood lymphocytes are only sporadically positive and, therefore, of limited value in making the diagnosis. Physicians prescribing organic gold compounds should elicit pulmonary complaints throughout the duration of therapy. When patients receiving gold therapy present with signs and symptoms consistent with an acute or subacute hypersensitivity pneumonitis, the gold therapy should be withheld and a diagnostic workup initiated.

Aged↗

PubMed1986

A study of the dynamic anatomy of extensor tendons and implications for treatment.

This study correlates the excursion of the extrinsic finger extensors in zones V, VI, and VII and the extensor pollicis longus tendon in zones T IV and T V ("T" is used to designate thumb zones) with joint motion. Excursion was estimated by review of the literature, biomechanic calculations, and intraoperative observations. A simple equation determines extrinsic extensor tendon excursion in zone V, VI, and VII. This equation is substantiated by Brand's work on radians and by intraoperative studies. Guidelines are suggested for controlled motion for extrinsic finger extensors and the extensor pollicis longus tendon on the basis of our 6 years experience of treating extensor tendon injury with early passive motion.

Biomechanical Phenomena↗

PubMed1986

Therapeutic management of extensor tendon injuries.

Experience will show that proper management during the first 3 postoperative weeks will be the major determinant for the final result in extensor tendon injuries. In the simple injury, meticulous care in properly immobilizing each joint, combined with edema control, allows the patient to begin the mobilization phase with few problems, and a simple course of therapy can be anticipated. In the complex injury, early passive motion techniques will reduce the devastating complications of an increased fibroblastic response common to crushing injuries or combined lesions of the extensor tendons.

Finger Injuries↗