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Biomedical subjects

D Wheeler

Publications and source records attributed to D Wheeler.

At least 91 records · Page 5Linked to original sources
PubMed1987

A comparison of volumetric and circumferential measures of penile erection.

Objective measurements of sexual arousal in men most commonly involve monitoring changes in penile size. Although changes in circumference are most often used, volumetric changes have been reported to be more sensitive and thus more effective. Six men volunteered to observe an erotic videotape while circumferential and volumetric changes of their penises were recorded. The two measures were significantly correlated (r = .68) but the volumetric device was more difficult to use, displayed considerably more artifacts, and was not more sensitive than a mercury-in-rubber strain gauge.

Adult↗
PubMed1987

Eye movement as a cue to figure motion in anorthoscopic perception.

When a figure moves behind a narrow aperture in an opaque surface, if it is perceived as a figure, its shape will often appear distorted. Under such anorthoscopic conditions, the speed or direction of the object's motion is ambiguous. However, when the observer simultaneously tracks a moving target, a figure is always perceived, and its precise shape is a function of the speed or direction of tracking. The figure is seen as moving with the speed or in the direction of the target. Thus, it is argued that eye movement serves as a cue to the figure's motion, which, in turn, determines its perceived length or orientation.

Cues↗
PubMed1986

High plasma urea concentrations in collodion babies.

We describe two infants born with a collodion membrane; both were treated with a product containing 10% urea and 5% lactic acid and as a consequence were found to have a raised plasma urea concentration.

Betaine↗
PubMed1985

Persistence and progression of immunologic abnormalities in haemophilia.

Immunologic parameters in 51 patients with haemophilia treated with cryoprecipitate from volunteer donors or with commercial lyophilized concentrate were studied on 2-7 occasions. Concentrate users had significantly decreased mean T4 (helper)/T8 (suppressor) lymphocyte ratios when the initial (1.5 +/- .43) and most recent (1.25 +/- .60) values were compared (p less than .001), whereas in cryoprecipitate users mean values remained normal. Of the 22 concentrate users with initially normal T4/T8 ratios, 10 became abnormal during the study, an incidence of 45%. Fifteen of 28 (54%) patients with abnormal T4/T8 ratios had elevated circulating immune complexes (CIC), whereas all 16 patients with normal T4/T8 ratios had normal levels of CIC. Six patients have persistent lymphadenopathy.

Antigens, Surface↗
PubMed1985

Traumatic neuroma of the intestine.

A traumatic neuroma of the intestine arising at the site of a previous ileocolic anastomosis is reported. Barium enema examination showed an extramucosal mass in a patient who presented with abdominal pain, rectal bleeding, and anemia. Although rare, traumatic neuroma should be included in the differential diagnosis of an intestinal mass occurring after intestinal surgery.

Adult↗
PubMed1984

Hypoglycemic coma induced by inadvertent administration of glyburide.

A 79-year-old nondiabetic woman was inadvertently given a 5-mg tablet of glyburide. Blood glucose concentration was 2.6 mmol/L three hours after ingestion. The patient was discharged 9 hours after ingestion and readmitted 10 1/2 hours after ingestion, in a hypoglycemic coma (blood glucose, 0.65 mmol/L). She was treated with two bolus doses of dextrose and intravenous dextrose. Her blood glucose was abnormal until hospital day 3. On hospital day 4, she was discharged with no apparent sequelae. This patient's severe reaction may have been due to mild renal insufficiency or concurrent use of timolol. Should inadvertent administration of glyburide occur in a patient with impaired renal function, the patient should be monitored for at least 24 hours.

Aged↗
PubMed1983

Generalized lymphadenopathy and T cell abnormalities in hemophilia A.

Two patients with hemophilia A had generalized lymphadenopathy, lymphopenia, elevated IgG values, depressed T4 (helper) lymphocytes, elevated T8 (suppressor) lymphocytes, and abnormally low T4/T8 ratios. One of the patients, who also had hepatosplenomegaly, underwent cervical lymph node biopsy; the node contained 43% T8-lymphocytes, a marked elevation over the small fraction of T8 cells usually found in lymph nodes. These patients may have a form of the acquired immune deficiency syndrome described in male homosexuals, Haitians, intravenous drug abusers, and recently, in patients with hemophilia. We studied T cell phenotypes in 43 patients with hemophilia. Fourteen of 28 patients given commercial factor VIII concentrates had abnormal T4/T8 ratios; none of nine patients who used cryoprecipitate had abnormal values. T4 helper cells were significantly lower, T8 suppressor cells significantly elevated, and T4/T8 ratios significantly lower in the lyophilized concentrate users and in patients with hemophilia as a total group. The type of therapeutic factor VIII replacement may alter the risk of developing T4/T8 abnormalities or AIDS.

Acquired Immunodeficiency Syndrome↗
PubMed1982

The construction of a plane from pictorial information.

Experiments are described which support the theory that the perception of a plane receding in depth is based on a process of construction. Displays were created which eliminated direct or higher-order stimulus information concerning the orientation of a plane, such as texture gradients or perspective. Instead, objects and the shadows they cast sufficed to suggest and support a depth interpretation. The perceived location of objects on this constructed plane affects size perception thereby providing evidence for a computational rather than a direct theory of constancy.

Cues↗
PubMed1980

Induced movement based on subtraction of motion from the inducing object.

Induced movement occurs not only when an object surrounding a stationary one moves below threshold but when it moves above threshold. The above-threshold effect is particularly puzzling and seemingly irrational because the relative displacement should be fully accounted for by perceiving the moving object in motion. The accepted theory has been that such excess motion can be explained in terms of a separation of systems: The enclosed object is governed by the relationship to its immediately surrounding frame of reference, and the latter is governed either by the relationship to its surrounding frame of reference or to the observer. An alternative explanation is that when induced motion occurs, the moving object is perceived to be either stationary or moving less than is warranted by its actual motion. Evidence is presented supporting this hypothesis according to which the relative displacement is apportioned phenomenally to either the induced object, the inducing object, or both. The objective motion of the inducing object is thus in whole or part transferred to the induced object. Thus, excess phenomenal motion does not occur, and induced movement can be regarded as the rational solution to a problem.

Form Perception↗
PubMed1979

Treatment of mild hypertension in elderly males.

1. Males, born between 1900 and 1925, with mild hypertension have been treated for periods varying from 300 to 2000 days. 2. The life and death status of all patients (except two) was known on 1st November 1978. 3. A group of patients with mild hypertension receiving treatment based on a thiazide diuretic had a greater mortality than the other drug-treated group. 4. The increased mortality was caused by an increased number of myocardial infarcts. 5. Elderly male patients with mild hypertension probably have preexisting vascular disease and therapy should not automatically be started. If therapy is started, beta-adrenoreceptor-blocking drugs may be a preferred therapy.

Adrenergic beta-Antagonists↗
PubMed1976

Hypertension detection and control in a rural white Kentucky community.

This report presents data on the prevalence of elevated blood pressure and the status of hypertension control in a rural Kentucky community. Medical care is provided to the population under study by a long established organization of nurse practitioners. With the exception of young males, detection of hypertension has been relatively successful. However, fewer than 50 per cent of persons with blood pressure greater than 160/100 mmHg are receiving antihypertensive therapy, and greater than 60 per cent of individuals on therapy have blood pressure greater than 160/100 mmHg. Despite detection of hypertension control has not been achieved in this rural white community.

Adolescent↗
PubMed1975

Test-induced anxiety with children.

Thirty-five elementary school children received the WISC, Rorschach, CAT, and Sentence Completion Test in counterbalanced order with a test-test interval of approximately 24 hours. State and trait anxiety measures were assessed immediately prior to and immediately following each test administration. Results indicated that state anxiety measures increased significantly following administration of the more ambigious and school related assessment tests, namely the Rorschach and WISC. In contrast, the more structured, less amorphous CAT and Sentence Completion Test, did not induce any significant changes in state anxiety. In all cases, trait anxiety measures remained relatively stable. Implications for assessment techniques with children were discussed.

Anxiety↗
PubMedDate not supplied

Information on DNA conformation derived from transverse pore gradient gel electrophoresis in conjunction with an advanced data analysis applied to capillary electrophoresis in polymer media.

Abnormally slow migration of DNA is conventionally viewed as being due to an abnormal conformation relative to "linear" standards. The evidence for this rests on a few instances where nonlinear DNA structures have been established by independent methods and yield low mobilities relative to standards. Transverse pore gradient gel electrophoresis of authentically bent kinetoplast DNA and of an upstream activator sequence (UAS) of an E. coli operon promoter shows in addition that curves of migration distance vs. gel concentration ("Ferguson curves") of such abnormally conformed DNA differ from those of "linear" standards. Since Ferguson curves are interpretable with regard to molecular size in concordance with a mathematical model (Ogston model), transverse pore gradient gel electrophoresis provides a simple means of correlating abnormally slow migration of DNA with molecular size. In addition, transverse pore gradient gel electrophoresis is able to distinguish between DNA banding which exhibits a steeper dependence on gel concentration than "linear" standards from one which shows the same dependence. The former appears characteristic of circularly bent DNA and gives rise to a substantial retardation, the latter of bending across a knot or kink in the DNA chain associated with a relatively minor retardation relative to standards. Circularly bent restriction fragments formed from kinetoplast DNA retain the characteristic intersecting Ferguson curves on the transverse pore gradient gel. Another authentically "abnormal" DNA structure recognizable on transverse pore gradient gels is supercoiled DNA derived from the reaction of topoisomerase with a plasmid. Different lengths of supercoiled sequences give rise to parallel Ferguson curves clearly intersecting with those of linear standards.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMedDate not supplied

Molecular sieving of lambda phage DNA in polyacrylamide solutions as a function of the molecular weight of the polymer.

Electrophoresis of lambda phage DNA was carried out in solutions at various concentrations of uncrosslinked polyacrylamide of 0.6, 1, 5 and 9 x 10(6) molecular weight (Mw) with narrow Mw distribution. By inspection of mobilities in the various concentration ranges, it appears that mobilities decrease, and retardation increases, with increasing Mw. The relation between electrophoretic retardation and the Mw of the polymer was also interpreted (i) in the manner previously applied to nonlinear Ferguson plots and compatible with the Ogston model; and (ii) empirically, on the basis of the first derivatives of the functions describing the Ferguson plots at the polymer concentrations used. Interpretation (i) shows that the retardation increases linearly in the order of 0.6, 1, 5 and 9 x 10(6) Mw of polyacrylamide. Interpretation (ii) shows a nonlinear increase of retardation in the Mw range 5 to 9 x 10(6), and a decrease in retardation as Mw is raised from 0.6 to 5.0 x 10(6). Hypothetically, interpretation (ii) can be explained mechanistically by a progressive change, as the polymer size is increased, from a collision with the surface of the polymer fiber to one occurring after permeation in the interior of a random-coiled fiber. Interpretation (i) may fail to detect that change due to the large difference between DNA mobility in solutions of the smallest polymer and the free mobility. DNA peak detection in all of the four size classes of polyacrylamide in solution is limited to relatively narrow ranges of polymer concentration.(ABSTRACT TRUNCATED AT 250 WORDS)

Acrylic Resins↗
PubMedDate not supplied

Biomechanical analysis of the effect of varying suture pitch in tendon graft fixation.

The purpose of this study was to biomechanically assess the effect of varying suture pitch on the holding power of the Krackow suture technique for tendon graft fixation. Seven pairs of rabbit Achilles tendons were sutured with single No. 5 Ti-Cron suture using the Krackow technique. One tendon from each pair was sutured using a 0.5-cm suture pitch (half-pitch group) while the contralateral tendon from each pair was sutured with a 1.0-cm suture pitch (one-pitch group). The tendons were loaded to failure using a servohydraulic materials test system at a loading rate of 0.5 mm/sec. There were no statistically significant differences noted in suture slippage at failure (1.58 cm for half pitch versus 1.45 cm for one pitch) or maximal force to failure (158.5 N for half pitch versus 168.2 N one pitch) between the two treatment groups. However, the construct with the 1-cm suture pitch was significantly stiffer than the construct with the 0.5-cm suture pitch, with stiffness values of 106.2 N/cm and 91.4 N/cm, respectively. The most common mechanism of failure was slippage of the suture at the first suture throw and tearing of the first knot through the most distal portion of the tendon. Four constructs failed by suture rupture, two from each experimental group.

Achilles Tendon↗