Search PubMed⌕ Search

Biomedical subjects

P Fox

Publications and source records attributed to P Fox.

At least 91 records · Page 5Linked to original sources

The contribution of a non-invasive test to clinical care. The impact of echocardiography on diagnosis, management and patient anxiety.

We prospectively studied the impact of echocardiography on a cardiologist's diagnosis and management plan and on patient anxiety for 300 consecutive referrals. There was an impact on diagnosis in 90% of patients. Most common was confirmation of diagnosis usually with the addition of information pertinent to management (81%); change of disease category or resolution of diagnostic doubt was uncommon (9%). The consultant cardiologist believed the heart to be normal in 48 patients who did not have any associated disease; none had any echocardiographic abnormality. The cardiologist reported increased diagnostic confidence in 74% of all patients but management changed in only 9%. One-third of all patients reported reduced anxiety when this was an important clinical issue but in less than half of them did the cardiologist consider that echocardiographic information was essential for reassurance. Anxiety was increased in 6%, and in 12% the anxiety response was inconsistent with the test result. The clinical contribution of the test report was most obvious for those patients (30%) in whom this data was required for (a) a decision concerning specific diagnostic or technical intervention (b) a change of management plan which implied obvious or likely health benefit (c) reassurance which was a clinically important issue. The magnitude of this contribution was related to the study indication. The value of echocardiography is obvious when assessing patients for invasive intervention or when proper treatment or adequate reassurance are impeded by diagnostic doubt. However, for many current indications, we need better definition of factors which predict a clinically useful result. In particular, when the aim is to rule-out disease, our results suggest that an expert cardiological opinion would often be more appropriate than an echocardiogram.

Adult↗

Prospective payment for psychiatry--feasibility and impact.

Although 15 diagnosis-related groups (DRGs) have been proposed for psychiatric hospital patients, psychiatric hospitals are currently exempt from the DRG prospective payment system. We investigated the ability of the psychiatric DRGs to predict the hospital length of stay and costs by retrospectively analyzing the charts of 8816 randomly selected patients from 32 psychiatric hospitals throughout the United States. In addition, we developed other grouping systems to see whether they would have been better predictors of length of stay. We found that grouping the patients in the 15 psychiatric DRGs reduced the total variance in length of stay by only 3.9 percent. Furthermore, our best alternative grouping--based on major diagnostic categories, whether the patient was transferred from another facility, age, and psychiatric complications and comorbidities--reduced the variance by only 7.8 percent. We conclude that DRGs do not adequately predict length of stay or costs in psychiatric hospitals. We identified factors other than diagnosis that predicted the length of stay better, but all the models we tested would create large financial "winners" and "losers" and thus introduce inappropriate incentives into the care of patients in psychiatric hospitals.

Costs and Cost Analysis↗

Gd-DTPA contrast enhancement and tissue differentiation in MR imaging of experimental breast carcinoma.

Gadolinium-DTPA (Gd-DTPA) enhancement of magnetic resonance (MR) imaging was tested for diagnostic utility in evaluating carcinoma. Human breast carcinoma implanted in ten nude mice was studied before and after injection of Gd-DTPA at two different doses (0.2 and 0.5 mmol/kg body weight). Before injection, all tumors appeared homogeneous in intensity on spin-echo images; after injection, it was possible to distinguish areas of strong enhancement from areas of weak enhancement. Histologic correlations showed that the strongly enhanced areas corresponded to richly vascularized connective tissue and apparently viable tumoral tissues, while the weakly enhanced areas corresponded to nonvascularized necrotic tissue. The results indicate that intravenously administered paramagnetic agents such as Gd-DTPA may improve the specificity and diagnostic accuracy of MR imaging by permitting better differentiation of tumor elements.

Adult↗

The application of positron emission tomography to the study of panic disorder.

Positron emission tomography was used to study eight patients with panic disorder who were vulnerable to lactate-induced panic, eight patients with panic disorder who were not vulnerable to lactate-induced panic, and 25 normal control subjects. Patients who were vulnerable to lactate-induced panic had several abnormalities in the resting, nonpanic state: an abnormal hemispheric asymmetry of parahippocampal blood flow, blood volume, and oxygen metabolism; abnormally high whole brain metabolism; and abnormal susceptibility to episodic hyperventilation. A hypothetical model for the neurobiology of panic disorder, involving the abnormal parahippocampal region and its afferent and efferent connections, is proposed.

Adult↗

The effect of SMS 201-995, a long-acting somatostatin analogue, on anterior pituitary function in healthy male volunteers.

The endocrine effect of SMS 201-995, an octapeptide analogue of somatostatin, was assessed during a combined anterior pituitary function test. There was no effect on the extent of hypoglycaemia after intravenous insulin infusion or on the subsequent rate of recovery of plasma glucose. SMS 201-995 administration, however, resulted in a profound and selective suppression of the GH response to hypoglycaemia without affecting the ACTH or cortisol responses. There was also a marked reduction of TSH release in response to intravenous TRH; the prolactin response was unimpaired. The LH response to LHRH was blunted and the FSH response unaffected. SMS 201-995 does not significantly impair the counterregulatory mechanisms in response to hypoglycaemia, and, in particular, the hypothalamic-pituitary-adrenal axis remains intact.

Adrenocorticotropic Hormone↗

Managed care: the answer to quality and cost concerns.

More and more providers and third-party payers are developing or at least participating in 'managed care systems,' which attempt to coordinate the activities of different health care providers in a variety of settings. The authors discuss the reasons behind the push toward managed care, and the ways in which hospitals can respond.

Comprehensive Health Care↗

Effects of ultraviolet radiation on human epidermal cell alloantigen presentation: initial depression of Langerhans cell-dependent function is followed by the appearance of T6- Dr+ cells that enhance epidermal alloantigen presentation.

The effects of ultraviolet radiation (UV) on the immune parameters of human epidermis were studied. We determined the effects of both in vitro and in vivo UV on human epidermal cell surface markers and on epidermal immune function in the allogeneic epidermal cell-lymphocyte reaction (ELR). Epidermal cells obtained immediately after in vitro and in vivo UV exposure exhibited a dose-dependent decrease in alloantigen-presenting function in the ELR. This was not the result of a decrease in the number of T6+ Dr+ Langerhans cells but was due to their being less efficient at alloantigen presentation than equivalent numbers of Langerhans cells from unirradiated skin. The reduced stimulation in the ELR immediately after UV was not reversible by the addition of exogenous IL 1 or indomethacin and thus appeared to be due to a direct effect of UV on the alloantigen-presenting function of Langerhans cells. In contrast to this suppression of the epidermal immune function when epidermal cells were obtained immediately after UV, epidermal cells harvested 24 hr or later after in vivo UV exhibited a dose-dependent enhancement of allostimulatory capacity in the ELR that peaked 3 days after UV. The time course of the enhancement of allostimulation in the ELR after in vivo UV coincided with a decrease in the percentage of Langerhans cells and the appearance within the epidermis of T6- Dr+ cells, which are derived from the bone marrow, as evidenced by their expression of the bone marrow derivation markers HLe 1 and T200. Removal of Dr+ cells but not of T6+ cells from epidermal cell suspensions harvested 3 days after in vivo UV abrogated allostimulation in the ELR, demonstrating that the T6- Dr+ cells were responsible for the observed UV-induced enhancement of alloantigen presentation. Taken together, the results indicate that the timing and dosage of UV exposure are critical factors determining whether suppression or enhancement of epidermal immune function follows UV.

Amputation, Surgical↗

Improvement in injury induced hypocalcia by high-dose naloxone intervention.

Naloxone hydrochloride was used to re-establish normal calcium activities in the extracellular space of the injured spinal cord. The micromolar levels of calcium which occur immediately after injury were improved above control values by 1 h 30 min post-injury; normal activities occurred at 2 h 45 min. Such a restitution of ionic levels after injury may contribute to the beneficial effects of naloxone in traumatic injury.

Animals↗

Control of burn wound infections by pefloxacin and its silver derivative.

As might be anticipated, strains of Pseudomonas aeruginosa resistant to silver sulfadiazine have appeared. We have found an analogue of nalidixic acid (pefloxacin) which, along with its silver derivative, is highly effective against these resistant strains. In vitro the minimal inhibitory concentrations are 10 to 20 times lower than that of silver sulfadiazine against bacteria. In burned mice and rats infected with silver sulfadiazine resistant pseudomonas strains, mortality in groups receiving topical therapy with pefloxacin and silver pefloxacin is about 10 per cent compared to 80 per cent with silver sulfadiazine (100 per cent in untreated controls). There is little systemic absorption of pefloxacin and no absorption of silver from topical treatment. In addition, silver pefloxacin exhibits higher antifungal activity in vitro.

Administration, Topical↗

Extracellular calcium activity in the injured spinal cord.

The extracellular concentration of calcium ion was measured in canine spinal cord subsequent to spinal injury. In the control animal, we found that calcium activities changed little independent of electrode placement in the spinal cord, were stable during the 3 h necessary to make injury measurements, and were comparable to other estimates of calcium in the interstitial space. After injury, calcium activities decreased to micromolar levels that were incompatible with neural function. An incomplete recovery of extracellular calcium occurred during the next 3 h to about one-third (0.44 +/- 0.01 mM) of the normal value (1.1 +/- 0.08 mM). Such a pattern of changes in extracellular calcium was specific for the injury site itself and did not occur at nearby anatomic loci. These results are interpreted as having both short- and long-term effects on neuronal function and subsequent reorganization of spinal pathways.

Animals↗

Progression of the milking effect of the coronary artery.

Myocardial bridging and systolic milking may be involved in myocardial ischemia, myocardial infarction, and sudden death. We describe a patient whose milking effect progressed significantly over a two-year period. We conclude that bridging and milking effect can progress over a relatively short period. In those patients with prior reports of insignificant bridging and milking on coronary arteriograms and continued angina-like chest pain, a repeated catheterization may be warranted.

Angina Pectoris↗

X-linked mental retardation: a study of 7 families.

Seven families with X-linked mental retardation (MR) have been studied clinically and cytogenetically. All affected males in six of the families were found to have a fragile site on Xq in a number of their peripheral lymphocytes. The fragile site was not seen in any of the affected males in the seventh family. The affected males in the six families with the fragile X had a syndrome characterized by a variable degree of MR, macro-orchidism, a characteristic repetitive, jocular speech, normal body proportions, and large jaws and ears. The fragile X chromosome could only be detected in a proportion of female carriers and its frequency in females was found to be correlated with their mental status to be inversely correlated with their age.

Adolescent↗

X-linked mental retardation: Renpenning revisited.

Nine men with X-linked mental retardation (MR) belonging to the family originally described by Renpenning and his colleagues have been reexamined and restudied. None of these men have the fragile X chromosome, and none have macro-orchidism; their testes range in size from small to average. All but one are severely retarded; one has an IQ of 70, the mean IQ of the remainder is 30 with a range of 18 to 45. They are short in stature, have small or normal-size ears and lower jaws, and a moderate degree of microcephaly, the mean skull circumference being just below two standard deviations from the normal.

Female↗