PubMed Health⌕ Search

Biomedical subjects

D A Goodman

Publications and source records attributed to D A Goodman.

At least 19 recordsLinked to original sources
PubMed2007

What does the brain do when you fake it? An FMRI study of pantomimed and real grasping.

Given that studying neural bases of actions is very challenging with fMRI, numerous experiments have used pantomimed actions as a proxy to studying neural circuits of real actions. However, the underlying assumption that the same neural mechanisms mediate real and pantomimed actions has never been directly tested. Moreover, the assumption is called into question by neuropsychological evidence suggesting that real actions depend on the dorsal stream of visual processing whereas pretend actions also recruit the ventral stream. Here, we directly tested these ideas in neurologically intact subjects. Ten right-handed participants performed four tasks: 1) grasping real three-dimensional objects, 2) reaching toward the objects and touching them with the knuckle without hand preshaping, 3) pantomimed grasping in an adjacent location where no object was present, and 4) pantomimed reaching toward an adjacent location. As expected, in the anterior intraparietal area, there was significantly higher activation during real grasping than that during real reaching. However, the activation difference between pantomimed grasping and pantomimed reaching did not reach statistical significance. There was also no effect of pantomimed grasping within the ventral stream, including an object-selective area in the lateral occipital cortex. Instead, we found that pantomimed grasping was mediated by right-hemisphere activation, particularly the right parietal cortex. These results suggest that areas typically invoked by real actions may not necessarily be driven by "fake" actions. Moreover, pantomimed grasping may not tap object-related areas within the ventral stream, but rather may rely on mechanisms within the right hemisphere that are recruited by artificial and less practiced actions.

Adult↗
PubMed1998

A pilot survey of radiation doses received in the United Kingdom Breast Screening Programme.

A survey of radiation dose and compressed breast thickness was conducted in samples of women undergoing mammography in the United Kingdom National Health Service breast screening programme. The aims were to determine the average value and distribution of dose and thickness, and to identify technical difficulties in carrying out such a survey. Values of breast thickness and mean glandular dose, calculated from exposure factors and measured X-ray beam parameters, were collected for 4633 women in 92 screening units in 1994 and 1995. The median (lower quartile, upper quartile) dose per film was 1.7 (1.2, 2.4) mGy for the mediolateral oblique view (mean thickness 57 mm) and 1.4 (1.1, 2.0) mGy for the craniocaudal view (mean thickness 52 mm). The median dose per woman was 1.8 (1.3, 2.5) mGy for a one-view examination and 3.3 (2.3, 4.6) mGy for a two-view examination. The dose per film showed an exponential relationship to breast thickness, but no relationship was found between median dose and median breast thickness in the different screening units, possibly because of errors in breast thickness measurement. The values of breast thickness and dose were generally consistent with those in other published surveys, allowing for differences in radiographic technique. No relationship between breast dose and standard optical density was demonstrated. Some recommendations for the conduct of future surveys of breast dose in the UK are proposed.

Breast↗
PubMed1997

Subclinical slipped capital femoral epiphysis. Relationship to osteoarthrosis of the hip.

We examined the femora of 2665 adult human skeletons from an osteological collection to determine the prevalence of post-slip morphology termed femoral head-tilt deformity by Murray and pistol-grip deformity by Stulberg et al. The hypothesis was that primary osteoarthrosis of the hip is a secondary manifestation of a subclinical developmental disorder of the hip. The prevalence of post-slip morphology was 8 per cent (215 of 2665 skeletons). Severe osteoarthrosis was more prevalent in association with post-slip morphology (116 [38 per cent] of 306 hips) than in the matched controls (seventy-nine [26 per cent] of 306 hips) (p < 0.005). In the skeletons that had unilateral post-slip morphology, severe osteoarthrosis was more prevalent in the involved hips (thirty-one [37 per cent] of eighty-three) than in the contralateral, normal hips (eighteen [22 per cent] of eighty-three) (p < 0.05). Post-slip morphology, which was unrelated to age, was found to be a major risk factor for the development of high-grade osteoarthrosis. We noted evidence of high-grade osteoarthrosis in sixty-three (68 percent) of the ninety-three hips with minimum post-slip morphology in skeletons from individuals who had been fifty-six years old or more at the time of death compared with forty-five (48 percent) of the ninety-three control hips. This difference was significant (p < 0.025) [corrected]. The osteoarthrosis in the hips with post-slip morphology was distinctly characterized by anterior flattening of the acetabulum, cystic degeneration in the anterior metaphyseal-epiphyseal region, and progression to global osteoarthrosis of the hip.

Acetabulum↗
PubMed1996

20-year chronobiologic study of a middle-aged cyclothymic male subject.

1. Cyclothymia is characterized by pronounced but not debilitating shifts of moods often lasting approximately two to nine weeks. 2. It can be classified as a psychopathologic mood disorder on a continuum to Bipolar II, or as a chronobiologic rhythm similar to the circadian except on an infradian time scale. 3. A male subject diagnosed cyclothymic agreed to daily chart moods and emotions, record dreams and monitor physical states. He kept track of hypomania-depression, high-low energy, high-low tension, dream affect and sleep parameters. 4. In the 1,006 affective cycles recorded between 1977 and 1996, four affective phases appeared sequentially: being comparable to early hypomania (I, PA), late hypomania (II, PD), early depression (III, ND) and late depression (IV, NA). 5. During the experiment lasting 20 years, the frequency of the four-phase affective cycle increased intermittently from 30.3 days (1977) to 28.0 days (1980), 24.7 days (1983), 19.0 days (1986), 17.8 days (1989), 12.1 days (1992), and 1.3 days (1995). 6. These findings of a four-phase variable infradian rhythm may have utility in determining fine structure and time course of rhythms in cyclothymics, both medicated and non-medicated, studied outside the clinical laboratory.

Adult↗
PubMed1996

Short communication: kilovoltage measurement with rhodium target and filters on mammography X-ray machines.

X-ray machines used for mammography have, until recently, almost exclusively employed molybdenum (Mo) as anode material and filtration. In the UK, the RMI model 232 kVp meter is used extensively for the measurement of kilovoltage on such equipment. This unit is provided with switchable internal calibration only for molybdenum and molybdenum, or tungsten and aluminium, as anode and filtration, respectively. However, rhodium (Rh) has recently been introduced for filtration with either a molybdenum or rhodium anode in mammography equipment but, as yet, calibration facilities are not available for rhodium spectra. In this work, appropriate corrections for readings obtained with the RMI 232 kVp meter are derived for use with rhodium as filtration material with either molybdenum or rhodium anode material. An intercomparison between measurements made with four RMI model 232 kVp meters and nine IGE DMR X-ray sets was undertaken. The reproducibility of the instruments was confirmed and measurements of tube potential made on each of the X-ray sets pooled. Measurements were made from a nominal 25-35 kVp using Mo/Mo, Mo/Rh and Rh/Rh target/filter combinations. Corrections for readings obtained with Mo/Rh and Rh/Rh were produced by comparison with readings obtained with Mo/Mo, assuming stability of tube potential between anodes. The results are compared with data recently produced by the manufacturer of the meter.

Calibration↗
PubMed1995

3D CT reconstruction in the surgical management of hepatic injuries.

We employed 3D reconstruction of CT images for evaluation of hepatic injuries in a series of eight trauma patients. One had additional reconstruction of a renal injury. 3D imaging provided precise anatomical delineation of damaged areas, particularly in relation to major vessels. Moreover, the imaging agreed with operative findings in every case. The 3D reconstruction facilitated decisions regarding intraoperative, reoperative and non-operative management. The improved imaging provided by 3D reconstruction may allow hepatic CT scans to be interpreted with greater ease and accuracy than conventional CT. We believe this is the first report of its use in liver trauma. Current indications may include postoperative confirmation of the extent of hepatic injuries, assessment before reoperation, and contribution to decisions regarding non-operative management. A limitation at present is the time taken for image production, but we suggest that in the future 3D imaging might contribute to evaluation before emergency surgery in patients with abdominal injuries.

Accidents, Traffic↗
PubMed1995

Use of the neutrophil:lymphocyte ratio in the diagnosis of appendicitis.

In patients with right lower quadrant pain, the total white cell count is an unreliable predictor of appendicitis. It has been reported that the lymphocyte count can fall in acute appendicitis. This study was undertaken to investigate whether the neutrophil:lymphocyte ratio is a more sensitive indicator than the total leucocyte count. A retrospective study was performed of patients undergoing appendectomy for suspected appendicitis over a 2-year period. A total of 402 patients were identified; histopathology confirmed appendicitis in 367 (91%). Other significant pathology was found in 13 (3.2%). Twenty-two (5.5%) had a histologically normal appendix and recovered uneventfully with no other diagnosis being made. A total of 298 (79%) patients with appendicitis had an elevated preoperative total white cell count. The neutrophil:lymphocyte ratio was calculated for each patient. Using an upper limit of 3.5:1, it was found that 324 (88%) of patients with appendicitis had a ratio equal to or greater than this value. This was significantly different from the proportion with a raised total leucocyte count (P = 0.001). We suggest that the simple calculation of the neutrophil:lymphocyte ratio may provide a parameter that is more sensitive than the total leucocyte count in the prediction of appendicitis.

Acute Disease↗
PubMed1991

Intensive care after abdominal aortic surgery.

This study examined the necessity for an intensive care environment after abdominal aortic surgery. The detailed records of 45 consecutive patients were reviewed for the first 48 h after operation, recording the occurrence and numbers of episodes of defined medical events or prescription of non-routine drugs. Medical events were hypertension (greater than 200 mmHg), hypotension (less than 100 mmHg), obliguria (less than 20 ml/h) and pulmonary problems. Thirty-six patients (80%) had medical events (hypertension 20, hypotension 17, oliguria 31, hypoxia 10, chest complications 12), and 38 (84%) had medical interventions. Only two had no events or interventions. Twenty-seven (59%) had more than one episode of a medical event which would not have been predicated from their preoperative state. There were three deaths (mortality 6.7%). These results support the case for intensive monitoring and immediate access to experienced medical advice for these patients. In hospitals where the intensive care unit is the best place to provide these facilities, elective operation may need to be deferred if an intensive care bed is not available.

Aged↗
PubMed1990

Lack of diurnal variation in the onset of non-Q wave infarction.

Data concerning the time of onset of myocardial infarction were obtained for 540 of the 544 patients with creatinine kinase (CK)-MB-confirmed non-Q wave myocardial infarction enrolled in the multicenter Diltiazem Reinfarction Study. Data were also collected for 627 patients who were screened but excluded. Among the 1,167 patients, no diurnal pattern of onset could be found at either 2- or 6-hour intervals. Among the 540 patients enrolled in the trial, no pattern could be found at these intervals either, although at 8-hour intervals, 27% of infarctions occurred between midnight and 8:00 AM, compared with 37% between 8:00 AM and 4:00 PM and 36% between 4:00 PM and 12:00 AM (p = 0.02). In contrast to the patterns previously noted for Q wave myocardial infarction, there was no preponderance of non-Q wave infarction in the late morning. Circadian rhythm was also absent among patients not treated with beta-blockers as well as among patients presenting with ST segment elevation on their enrollment electrocardiograms. Diabetics, women, and patients with first infarction were more likely to present during the afternoon hours. We conclude that the late morning preponderance seen for Q-wave myocardial infarction is not discernable in patients with non-Q wave myocardial infarction. This observation suggests that the pathogenesis of these two infarct subtypes is different or that the process of thrombotic coronary occlusion in Q wave infarction (sustained) differs from that in non-Q wave infarction (nonsustained).

Adrenergic beta-Antagonists↗
PubMed1982

Intracellular and extracellular responses in the organ of Corti of the gerbil.

Techniques have been developed for recording from and staining cells in the organ of Corti of the Mongolian gerbil. Using physiological criteria as in the guinea pig, the cells were classified as either supporting cells or inner hair cells (IHCs). In addition, several IHCs were stained using HRP and identified in surface preparations. Extracellular responses in the vicinity of IHCs were tuned as sharply as auditory-nerve fibers. Intracellular tuning curves of IHCs were equally sharp near their tips. However, the tip-to-tail distances and sensitivities appeared to be somewhat reduced, presumably due to trauma caused by the recording electrode. Intensity functions, relating receptor depolarization to stimulus intensity level, were obtained for the IHCs. The functions have a consistent quantitative form for frequencies equal to or less than the characteristic frequency of a cell. At low stimulus levels the response increases in proportion to energy, i.e. the square of the sound pressure level. At high levels the response increases more slowly, but shows a greater operating range, and smaller effects of saturation, than do the steady-state responses of single auditory-nerve fibers.

Animals↗
PubMed1980

Effects of x-radiation on fibreoptic endoscopes.

Fibreoptic endoscopes exposed to x-radiation showed increased optical density of the fibre bundles with a reduction in light transmission. The length irradiated was important as well as the total dose, and there was a linear relationship between the dose/length product (Rm) and the loss of light transmission. The minimum light transmission acceptable for performing ERCP was found to be 57% of that through an unused fibre bundle, and this degree of damage occurred after a total dose of 33.9 Rm. The radiation dose to the duodenoscope during ERCP examinations was measured. The endoscope sheath was shown to have screening properties, with a transmission factor of about 30% for the Olympus JFB-1 and about 11% for the JFB-2 and JFB-3 instruments. The actual dose received by the fibre bundle of an Olympus JFB-2 duodenoscope was 0.084 R per ERCP and the mean dose-length product to the fibre bundle was calculated as 0.028 Rm per ERCP. Some degree of recovery of light transmission occurred while a duodenoscope was 'resting'. The expected life of a duodenoscope was estimated to be about 1200 examinations, but might be much less than this in units where greater radiation doses and longer exposures were used, and the endoscope was in constant use. Ways of minimising the radiation exposure during ERCP and prolonging the useful life of the duodenoscope are outlined.

Cholangiopancreatography, Endoscopic Retrograde↗