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Biomedical subjects

P A Mackowiak

Publications and source records attributed to P A Mackowiak.

At least 19 recordsLinked to original sources
PubMed1998

Effects of IFN-beta on human cerebral blood flow distribution.

The effect of interferon-beta1b (IFN-beta) on human cerebral blood flow distribution was examined in five multiple sclerosis patients using functional brain single-photon emission tomography (SPECT). Of nine regions of interest studied, only the basal ganglia exhibited a significant change (increase) in relative photon emission intensity (i.e., relative blood flow) when comparing SPECT scans obtained 6 h after s.c. IFN-beta injection with scans obtained at the same time of day (noon) 30 h after IFN-beta injection (IFN-beta-free day). The increase in relative blood flow to the basal ganglia following IFN-beta injection correlated positively with changes in mean arterial pressure (MAP). Additional studies will be required to determine the relevance of these observations for IFN-beta-induced central nervous system side effects.

Adult↗
PubMed1997

Concepts of fever: recent advances and lingering dogma.

Fever has been a preoccupation of clinicians since medicine's beginning. One might therefore expect that basic concepts relating to this physiological response would be well delineated and that such concepts would be widely known. In fact, only in the past several decades has the febrile response been subjected to scientific scrutiny. As a result of recent scientific investigation, modern concepts have evolved from a perception of fever as nothing more than a rise in core temperature to one in which fever is recognized as a complex physiological response characterized by a cytokine-mediated rise in temperature, as well as by generation of acute-phase reactants and activation of a panoply of physiological, endocrinologic, and immunologic systems. The average clinician appears to have little more than a regrettably rudimentary knowledge of these modern concepts of fever. This symposium summary considers many such concepts that have immediate relevance to the practice of medicine.

Acute-Phase Proteins↗
PubMed1997

The salary responsibility program for full-time faculty members in an academic clinical department.

The authors report a system developed in the Department of Medicine of the University of Maryland School of Medicine to encourage members of the full-time faculty to assume greater responsibility for their compensation. A member of the department's administrative staff individually interviews each faculty member and fills out, with the member, a "scorecard" that contains the number of hours per month and per year that the member reports were spent on his or her duties--such as teaching, attending, and consulting--that are assigned by the department or its divisions. This report also contains the record of unassigned time devoted to research (for investigators) or to personal practice (for clinicians). Assigned duties includes the time spent by clinicians performing procedures such as bronchoscopy cardiac catheterization, and endoscopy. The department pays for the otherwise unsupported costs of salary and benefits associated with assigned duties, and the faculty member is responsible for part of his or her compensation for time spent in research or practice. The program was developed and the data collected during the summer and fall of 1995. The salary reductions were applied on July 1, 1996. During the 1996-97 academic year the department projects a savings of $110,362 from compensation withheld from faculty members unable to fulfill their salary responsibilities and not paid to members who left the department, in part because of expected reductions in their incomes. The program has stimulated other faculty members to develop salary support with even greater vigor than that might otherwise have shown.

Clinical Medicine↗
PubMed1996

Effects of anatomic site, oral stimulation, and body position on estimates of body temperature.

BACKGROUND: A prior investigation characterized the range of body temperature in healthy young adults and established the importance of diurnal variations in defining the febrile state. METHODS: Sequential rectal, oral, and tympanic membrane temperature measurements were performed on 22 healthy subjects to determine the quantitative effects of anatomic site, oral stimulation, and body position on estimates of body temperature. RESULTS: Mean rectal temperatures exceeded concurrent oral readings by 0.4 degrees C +/- 0.4 degrees C (0.8 degrees F +/- 0.7 degrees F), which, in turn, exceeded concurrent tympanic membrane readings (obtained with a digital thermometer [IVAC Corp, San Diego, Calif]) by 0.4 degrees C +/- 1.1 degrees C (0.7 degrees F +/- 2.0 degrees F). Tympanic membrane readings were significantly more variable (both intrasubject and intersubject) than rectal or oral readings, especially when cerumen was present in the external ear canal being examined (P<.05). Mastication and smoking both caused significant increases in oral temperature that persisted for greater than 20 minutes. Drinking ice water caused a significant but more transient decrease in oral temperature. Of these activities, only mastication appeared to influence tympanic membrane readings. Body position exerted a modest effect on rectal temperature readings, but did not significantly affect oral or tympanic membrane readings. CONCLUSIONS: These findings indicate that, in addition to diurnal fluctuations in body temperature, the effects of anatomic site, oral stimulation, and body position should be considered in establishing criteria for the febrile state.

Adult↗
PubMed1996

The pharmacologic consequences of fever.

Despite its potential importance to the management of patients with febrile illnesses, the effect of fever on pharmacokinetics and pharmacodynamics has received little attention in the clinical literature. This article considers literature published in this potentially important area.

Animals↗
PubMed1996

Fever's glass ceiling.

The importance of an upper limit of the febrile response has been recognized since the time of Hippocrates. Although the precise temperature defining this limit varies according to the site at which body temperature is measured, human core temperature is almost never permitted to rise above 41 degrees C-42 degrees C during fever. There are compelling physiological reasons for such an upper limit of regulated body temperature. The mechanisms by which the limit is maintained are most likely complex and involve special properties of thermoregulatory neurons themselves, circulating endogenous antipyretics (such as arginine vasopressin and alpha-melanocyte-stimulating hormone), and soluble receptors for the (pyrogenic) cytokine mediators of the febrile response.

Animals↗
PubMed1995

Physicians' perceptions regarding body temperature in health and disease.

Although body temperature has been monitored for more than a century as a means of distinguishing health from disease, physicians' perceptions of concepts of clinical thermometry are largely unknown. To characterize such perceptions, we did a descriptive analysis of responses to a survey questionnaire dealing with body temperature. Seventy-five percent of the 268 physicians and physicians-in-training surveyed offered 37 degrees C (98.6 degrees F) as their definition of "normal body temperature." Only 10 (4%) specified a particular body site (eg, oral or rectal) of temperature measurements in their definition. Although 98% believed that body temperature normally varies during the day, there was not a consensus as to the magnitude of such variability. There was also considerable disagreement as to the specific temperatures defining the lower and upper limits of the febrile range. Subjects exhibited a clear preference for the Fahrenheit scale in their responses. Medical students differed significantly from graduate physicians in several of the areas examined.

Body Temperature↗
PubMed1994

Fever: blessing or curse? A unifying hypothesis.

Considerable data indicate that fever and its mediators have the capacity both to potentiate and to inhibit resistance to infection. It is difficult to reconcile these apparently contradictory observations if they are viewed solely from the standpoint of the individual. However, when viewed from the perspective of the species, both fever's salutary effects on mild to moderately severe infections and its pernicious influence on fulminating infections become teleologically plausible. If one accepts preservation of the species, rather than survival of the individual, as the essence of evolution, fever and its mediators might have evolved as mechanisms both for accelerating recovery of individuals from localized or mild to moderately severe systemic infections in the interest of continued propagation of the species and for hastening the elimination of fulminantly infected individuals who pose a threat of epidemic disease to the species.

Animals↗
PubMed1994

Quantitative relationship between oral temperature and severity of illness following inoculation with candidate attenuated dengue virus vaccines.

The relationship between oral temperature and other parameters of illness was examined in 51 adult volunteers who were inoculated experimentally with partially attenuated candidate dengue virus vaccines. In subjects who developed clinical illness, the peak illness temperature, mean illness temperature, and peak 6:00 A.M. illness temperature all correlated positively with the total number of signs and symptoms other than fever and with a fall in the white blood cell count (the latter was the only laboratory abnormality significantly associated with clinical illness [P = .02]). Of these factors, the peak 6:00 A.M. oral temperature exhibited the strongest correlations with the two parameters used to estimate severity of illness (rxy = .58 and P < .01 for signs and symptoms; rxy = .37 and P = .01 for fall in white blood cell count).

Adolescent↗
PubMed1993

Relationship between humoral immune responses and oral temperature during human shigellosis.

The relationship between oral temperature and serum IgA and IgG antibody responses to Shigella sonnei infection was examined in 65 experimentally infected adult volunteers. Although the IgA antibody response appeared to correlate directly with the rise in oral temperature following infection, stepwise regression analysis revealed other associated signs and symptoms as the critical elements underlying this apparent correlation. There was no evidence of a positive correlation between the IgG antibody response and the peak increment in oral temperature after infection. Although published data obtained in vitro suggest that fever might have a potentiating effect on antibody production, no such effect was seen in human volunteers with acute shigellosis.

Adult↗
PubMed1992

An analysis of the quantitative relationship between oral temperature and severity of illness in experimental shigellosis.

The relationship between oral temperature and other parameters of illness was examined in 139 adult volunteers infected experimentally with Shigella sonnei. In subjects developing clinical disease, peak temperature correlated positively with total number of signs and symptoms other than fever (rxy = .71, P < .001), stool volume (rxy = .41, P < .001) and number of stools produced during the illness (rxy = .46, P < .001). Peak temperature correlated negatively with incubation period (rxy = -.34, P = .007) but exhibited no apparent correlation with duration of illness. The average oral temperature during illness correlated positively with number of other signs and symptoms of infection but not with stool volume or stool number. These results suggest that in clinical investigations involving S. sonnei, and perhaps with other pathogenic microorganisms, oral temperature is a useful quantitative marker for estimating disease severity.

Adult↗
PubMed1991

Relationship between cytomegalovirus and colonization of the oropharynx by gram-negative bacilli following renal transplantation.

Numerous investigators have reported an increased incidence of pneumonia caused by Gram-negative bacilli and other secondary pathogens in transplant recipients infected by cytomegalovirus (CMV). To determine if CMV infections are related to colonization of the upper respiratory tract by Gram-negative bacilli, we examined prospectively 22 renal transplant recipients with sequential bacteriological, virological and biochemical examinations performed just prior to and at various times after transplantation. Only 11% of subjects had Gram-negative bacilli isolated from gargle specimens prior to transplantation, as compared to 54% after transplantation. More importantly, after transplantation, subjects with active CMV infections were more likely to have prolonged oropharyngeal carriage of Gram-negative bacilli than subjects without CMV infections (36% v. 25%). During active CMV infections, the rate at which Gram-negative bacilli were isolated from gargle specimens rose from 28 to 47%. During culture-positive CMV infections, the isolation rate reached 57% and was significantly different from that of CMV-negative samples (P less than 0.01). The increased rate of Gram-negative bacillary isolation from gargle specimens during CMV infections was not a function of type of immunosuppressive agents used, rejection episodes, antibiotic administration, concomitant hepatitis B, Epstein-Barr (EBV) virus, or herpes simplex virus infections, or alterations in salivary fibronectin concentrations.

Adult↗