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Biomedical subjects

G E Brown

Publications and source records attributed to G E Brown.

At least 37 records · Page 2Linked to original sources
PubMed1999

Forced exercise blocks learned helplessness in the cockroach (Periplaneta americana).

For three consecutive days, two groups of adult female cockroaches (Periplaneta americana) (ns = 10) received inescapable shock. 24 hr. later one group was exposed to 10 min. of forced exercise on a treadmill while the other group received no exercise. Both groups were then run in a shuttlebox escape task. The cockroaches exposed to forced exercise did not become helpless in the shuttlebox escape task.

Animals↗
PubMed1999

Priming of the neutrophil respiratory burst is species-dependent and involves MAP kinase activation.

BACKGROUND: Priming of the neutrophil respiratory burst has been implicated in the pathogenesis of multi-system organ failure (MSOF) after sepsis and trauma. The intracellular signal transduction pathways that mediate priming are unclear. METHODS: Human, porcine, rabbit, rat, and mouse neutrophils were assayed by luminol-dependent chemiluminescence in whole blood and purified neutrophil preparations. Multiple priming agents and agonists were studied, as was inhibition of priming by the p38 mitogen-activated protein kinase (MAPK) inhibitor SB203580 and the Mek 1/2 inhibitor PD98059. RESULTS: Priming by tumor necrosis factor alpha (TNF-alpha), interleukin-8 (IL-8), and granulocyte-macrophage colony-stimulating factor (GM-CSF) was significantly inhibited by SB203580, whereas platelet-activating factor (PAF) priming was unaffected. Neither TNF-alpha nor PAF primed polymorphonuclear neutrophils (PMNs) within whole blood for N-formyl-methionyl-leucyl-phenylalanine (f-MLP) activation, in contrast to activation by complement-opsonized zymosan (OPZ) or low-dose phorbolmyristate acetate (PMA). Both TNF-alpha and PAF, however, primed purified neutrophils for f-MLP activation. In contrast to human and porcine PMNs, rabbit, rat, and mouse PMNs could not be primed by TNF-alpha or PAF, regardless of the final agonist. CONCLUSIONS: Priming of the PMN respiratory burst proceeds through multiple signaling pathways, depending on the particular priming agent and agonist pair. Differences in priming between PMNs in whole blood and purified preparations may be physiologically significant. There is a pronounced species dependency in the ability to prime the neutrophil respiratory burst.

Animals↗
PubMed1998

Redesign for effective quality assurance: pilot program in an urban community hospital.

An urban community hospital redesigned the quality assurance (QA) procedures of its medical staff to increase the effectiveness of QA. The best features of the plans of several leading hospitals were presented to departments and committees. These redesigned their QA efforts into a hospital-wide plan. Leadership commitment to redesign, increased process objectivity, and more horizontal structure resulted in the identification of adverse events and the assignment of numerical assessments to them. The rate of adverse event detection was equal to the rate achieved by the literature's benchmark study.

Hospitals, Community↗
PubMed1998

Reduction of microorganisms on citrus fruit surfaces during packinghouse processing.

Citrus fruit surface microbial populations were evaluated following various packingline processes of seven Florida commercial packinghouses. At each packinghouse, six fruits (oranges or tangerines) were collected at each of four sampling points. The sampling was conducted in duplicate; thus, 336 fruit were evaluated during this survey. Average aerobic plate counts and yeast and mold counts on fruit surfaces before washing were about 4.0 log CFU/cm2 and 3.3 log CFU/cm2, respectively, and were reduced to 2.1 log CFU/cm2 and 1.3 log CFU/cm2, respectively, by packinghouse processing. Waxing alone reduced the average fruit surface aerobic plate counts and coliform counts from 3.7 log CFU/cm2 and 35.2 most probable number (MPN)/cm2, respectively, to 2.6 log CFU/cm2 and 1.4 MPN/cm2. No Escherichia coli was recovered from fruit at the end of packinghouse processing, and no salmonellae were found on fruit during the entire processing. In an inoculation study to test the effect of packinghouse processes, test organism E. coli was applied to fruit to achieve a high level (4.8 log CFU/cm2) of contamination. The average E. coli count was reduced about 2.4 log cycles by washing and rinsing with potable water (40 psi, 25 degrees C) for about 30 s. The combination of washing and waxing significantly reduced the inoculated level of E. coli from 4.8 to 1.4 log CFU/cm2.

Bacteria↗
PubMed1997

Maintenance and down-regulation of primed neutrophil chemiluminescence activity in human whole blood.

Priming of polymorphonuclear neutrophils (PMN) in whole blood (by tumor necrosis factor alpha and interleukin-8 for enhancement of luminol-dependent chemiluminescence induced by human complement-opsonized zymosan) was stable for 120 min. In contrast, priming of isolated PMN in plasma-free suspension for responses to opsonized zymosan, formyl-methionyl-leucyl-phenylalanine, and phorbol myristate acetate was markedly less stable. Decay of priming was not due to irreversible inactivation of the terminal CL production machinery because PMN could be reprimed by platelet-activating factor or leukotriene B4. The tumor necrosis factor-alpha-primed state of isolated PMN was stabilized by host plasma in a concentration-dependent fashion. We conclude that PMN priming results in a dynamic state that is reversible. Our findings suggest the existence of blood-borne components that may act to stabilize or modify PMN priming.

Down-Regulation↗
PubMed1997

Protective effects of prostaglandin E1 on acute lung injury of caerulein-induced acute pancreatitis in rats.

Infusion of a supramaximally stimulating dose of the pancreatic secretagogue caerulein (10 micrograms.kg-1.h-1) for 4 h induces interstitial edematous acute pancreatitis in rats. This model of acute pancreatitis is associated with evidence of acute lung injury, including sequestered neutrophils within the pulmonary microvasculature, increased microvascular permeability, and interstitial pulmonary edema. Infusion of prostaglandin E1 (PGE1; 50 ng.kg-1.min-1) along with caerulein does not alter the severity of secretagogue-induced pancreatitis, but it does reduce the severity of pancreatitis-associated acute lung injury. The rise in lung weight, lung water content, and pulmonary microvascular permeability and the sequestration of neutrophils within the pulmonary microvasculature that accompany secretagogue-induced pancreatitis are all reduced by infusion of PGE1. Infusion of PGE1 does not interfere with polymorphonuclear neutrophil sequestration in the pancreas or reduce the enhanced expression of CD11b/c receptors on circulating neutrophils. Our observations indicate that PGE1 reduces the severity of pancreatitis-associated acute lung injury by preventing neutrophil sequestration within the lung. We speculate that PGE1 interferes with neutrophil sequestration by dilating pulmonary vasculature, increasing pulmonary flow rate, and reducing neutrophil-endothelial cell interaction and attachment.

Acute Disease↗
PubMed1996

Calcaneal fillet flap: a new osteocutaneous free tissue transfer for emergency salvage of traumatic below-knee amputation stumps.

Traumatic below-knee amputations do not always leave enough soft tissue of bone with which to fashion a stump of sufficient length and durability to support a prosthesis. Composite free flaps can often be harvested from the amputated limb to provide immediate one-stage stump salvage and to preserve knee function. We report a new technique to increase stump length by incorporating the calcaneus into a foot fillet flap as a vascularized bone transfer. The calcaneal fillet flap is a useful addition to the inventory of available composite flaps. It is recommended for knee joint salvage when there is less than 11 cm of tibial remnant length.

Adult↗
PubMed1995

Cold-induced amnesia blocks escape deficits in the cockroach (Periplaneta americana).

For three consecutive days, four groups of adult cockroaches (Periplaneta americana) were yoked to cockroaches receiving escapable shock. The four groups of subjects received either inescapable shock followed by exposure to 12 minutes of cold (2 degrees C), inescapable shock followed by no exposure to cold, no-shock followed by exposure to cold, or no-shock followed by no exposure to cold. 24 hr. later all five groups were run on a different escape task. The cockroaches exposed to inescapable shock followed by no exposure to cold showed the usual escape deficit. The cockroaches exposed to inescapable shock followed by exposure to cold did not alter from the escapable shock cockroaches or the controls.

Animals↗
PubMed1994

Prevalence of lactose maldigestion. Influence and interaction of age, race, and sex.

Ninety-eight adults ranging from 20 to 89 years in age (52 blacks, 46 whites, 48 males, 50 females) were tested for lactose maldigestion by breath hydrogen analysis after consuming milk containing 16.5 g lactose (360 ml milk). Older adults (> or = 50 years) displayed a significantly higher incidence (46%) of lactose maldigestion than younger adults (< 50 years, 26%). In younger adults there were 2.4 times more maldigesters in blacks than in whites, while in older groups this ratio was 3.6. Level of breath hydrogen significantly increased with age up to the age group of 60-69 years. The interaction between age groups and race was highly significant. Of the maldigesters, 63% reported symptoms and 3% of the total sample reported severe symptoms. Results of this study indicate that the prevalance of lactose maldigestion significantly increases with age in blacks compared to whites and that the magnitude of the problem may be greater in black maldigesters than in white maldigesters.

Adult↗
PubMed1994

The freedom and the responsibility of investigator-initiated research.

Since World War II, scientific inquiry and research have been based on the premise that the more investigator-initiated research is conducted, the more automatic benefits for society are created. It is finally becoming clear to many that this belief is neither rational, true, nor healthy; in short, we as a society have been indiscriminately embracing whatever we are able to do instead of doing those things that will take society where it needs to go. Trickle-down science and technology do not work any better than the famous trickle-down economics worked. The author praises the accomplishments of scientific research but gives several examples, including those involving health care, of the widening gap that unguided science and technology have helped to foster between the advantaged and disadvantaged populations in most of the world, including the United States. He proposes that while investigator-initiated research is crucial, it must be done in the context of strategic paths and a set of values that direct it toward achieving the goals for the nation and the world that must be reached if the planet and its increasing population are to survive. He emphasizes that such strategic paths provide the compass; they do not control the journey. For example, he is not saying that biomedical researchers should be directed to specific experiments, but rather that as researchers they must realize the moving from remediation to prevention is a primary national and international goal for human health.(ABSTRACT TRUNCATED AT 250 WORDS)

Freedom↗
PubMed1994

Shock-induced Analgesia in the cockroach (Periplaneta americana).

For 3 consecutive days cockroaches (Periplaneta americana) received escapable, inescapable, or no shock in an escape task. 24 hr. later minimum shock which initiated movement was identified. Reliably higher shocks were needed to initiate movement in the inescapably shocked roaches. In a second experiment the analgesia induced by inescapable shock was blocked by the opiate antagonist naloxone. The results are discussed in relation to the escape deficit and analgesia commonly seen following exposure to inescapable shock in a variety of species.

Animals↗
PubMed1994

Escape deficits induced by a biologically relevant stressor in the slug (Limax maximus).

For 7 consecutive days slugs (Limax maximus) were exposed to escapable, inescapable, or no light-heat stress in an escape task. On Days 8 and 9 they were tested in a different escape task. The slugs in the inescapable light-heat group had reliably longer escape latencies and more failures to escape than the slugs in the escapable light-heat group or the no light-heat control group.

Animals↗
PubMed1994

Publication productivity in academic family medicine departments.

BACKGROUND AND OBJECTIVES: The purpose of this study was to quantify research publication productivity of family medicine departments in selected family medicine and interdisciplinary journals. METHODS: A 5-year journal search was conducted to identify original research articles published by family medicine department faculty. Publication productivity of all departments was ranked, and regression analysis was used to identify predictors of publication productivity. RESULTS: The departments leading in publication productivity published more than 25 articles over the 5-year period. The number of faculty and mean dollar value of family medicine department establishment grants were the strongest predictors of publication productivity. When adjusted for departmental size, some departments were found to have high publication productivity per faculty member, even though total numbers of departmental publications were low in comparison to other departments. CONCLUSIONS: This study identified one way of comparing departments in terms of publication productivity. Large departments, and those with more developmental grant support, have the highest publication productivity.

Faculty, Medical↗