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Biomedical subjects

Kimberly A Moran

Publications and source records attributed to Kimberly A Moran.

8 recordsLinked to original sources

In harm's way: infections in deployed American military forces.

Hundreds of thousands of American service members have been deployed to Afghanistan and Iraq since 2001. With emphasis on the common infections and the chronic infections that may present or persist on their return to the United States, we review the data on deployment-associated infections. These infections include gastroenteritis; respiratory infection; war wound infection with antibiotic-resistant, gram-negative bacteria; Q fever; brucellosis; and parasitic infections, such as malaria and leishmaniasis.

Brucellosis↗

Limited regulation of somatodendritic dopamine release by voltage-sensitive Ca channels contrasted with strong regulation of axonal dopamine release.

The mechanism underlying somatodendritic release of dopamine (DA) appears to differ from that of axon-terminal release. Specifically, somatodendritic DA release in the substantia nigra pars compacta (SNc) persists in low extracellular Ca2+ concentrations that are insufficient to support axonal release in striatum, suggesting that limited Ca2+ entry is necessary to trigger somatodendritic release. Here, we compared the role of voltage-dependent Ca2+ channels in mediating DA release in striatum versus SNc using specific blockers of N-, P/Q-, T-, R- and L-type Ca2+ channels individually and in combination. Release of DA evoked by a single stimulus pulse in the dorsal striatum and SNc of guinea-pig brain slices was monitored in real time using carbon-fiber microelectrodes with fast-scan cyclic voltammetry. Single-pulse evoked DA release was shown to be independent of regulation by concurrently released glutamate or GABA acting at ionotropic receptors in both regions. Under these conditions, striatal DA release was completely prevented by an N-type channel blocker, omega-conotoxin GVIA (100 nm), and was decreased by 75% by the P/Q-type channel blocker omega-agatoxin IVA (200 nm). Blockade of T-type channels with Ni2+ (100 microm) or R-type channels with SNX-482 (100 nm) decreased axonal release in striatum by 25%, whereas inhibition of L-type channels with nifedipine (20 microm) had no effect. By contrast, none of these Ca2+-channel blockers altered the amplitude of somatodendritic DA release in the SNc. Even a cocktail of all blockers tested did not alter release-signal amplitude in the SNc, although the duration of the release response was curtailed. The limited involvement of voltage-dependent Ca2+ channels in somatodendritic DA release provides further evidence that minimal Ca2+ entry is required to trigger the release process, compared with that required for axon-terminal release.

Animals↗

Infectious diseases during wartime.

PURPOSE OF REVIEW: The infectious disease challenges of war include pathogens endemic to the geographic area of operations as well as wound infections with common environmental microorganisms. This review summarizes papers, unpublished data and personal communications from 2004-2005 pertaining to infectious diseases during war with a focus on the current operations in Iraq and Afghanistan. RECENT FINDINGS: To date, there have been several hundred cases of cutaneous leishmaniasis and five cases of visceral leishmaniasis among US military personnel serving in southwest Asia. There have been reports of malaria in soldiers serving in Afghanistan and an outbreak of acute eosinophilic pneumonia among soldiers serving in or near Iraq. Diarrheal illness is a well-known threat to military operations and remains problematic for combatants throughout the theater of operations. Infectious complications caused by multiply drug-resistant Acinetobacter baumannii have been particularly challenging for healthcare providers managing the wounded evacuated from Iraq. We are now facing outbreaks of nosocomial infection with this pathogen in military treatment facilities in Europe and the USA. SUMMARY: Historically, infectious diseases have had significant impact on the conduct of military operations, and the conflict in southwest Asia is no exception. Physicians caring for returning military personnel should be aware of the diseases prevalent in this campaign, particularly cutaneous leishmaniasis and infections with multiply drug-resistant A. baumannii.

Afghanistan↗

Multidrug-resistant Acinetobacter extremity infections in soldiers.

War wound infection and osteomyelitis caused by multidrug-resistant (MDR) Acinetobacter species have been prevalent during the 2003-2005 military operations in Iraq. Twenty-three soldiers wounded in Iraq and subsequently admitted to our facility from March 2003 to May 2004 had wound cultures positive for Acinetobacter calcoaceticus-baumannii complex. Eighteen had osteomyelitis, 2 burn infection, and 3 deep wound infection. Primary therapy for these infections was directed antimicrobial agents for an average of 6 weeks. All soldiers initially improved, regardless of the specific type of therapy. Patients were followed up to 23 months after completing therapy, and none had recurrent infection with Acinetobacter species. Despite the drug resistance that infecting organisms demonstrated in this series, a regimen of carefully selected extended antimicrobial-drug therapy appears effective for osteomyelitis caused by MDR Acinetobacter spp.

Acinetobacter↗

Vesicular reuptake inhibition by a synaptotagmin I C2B domain antibody at the squid giant synapse.

Synaptotagmin (Syt) I, a ubiquitous synaptic vesicle protein, comprises a transmembrane region and two C2 domains. The C2 domains, which have been shown to be essential for both synaptic vesicle exocytosis and endocytosis, are also seen as the Ca(2+) sensors in synaptic vesicular release. In a previous study, we reported that a polyclonal antibody raised against the squid (Loligo pealei) Syt I C2B domain, while inhibiting vesicular endocytosis, was synaptic release neutral at the squid giant synapse. Recent reports concerning the C2B requirements for synaptic release prompted us to readdress the role of C2B in squid giant synapse function. Presynaptic injection of another anti-Syt I-C2B antibody (using recombinant whole C2B domain expressed in mammalian cell culture as an antigen) into the presynaptic terminal reproduced our previous results, i.e., reduction of vesicular endocytosis without affecting synaptic release. This set of results addresses the issue of the geometrical arrangement of the Ca(2+) sensor, allowing the C2B domain antibody to restrict Ca(2+)-dependent C2B self-oligomerization without modifying the Ca(2+)-dependent release process.

Animals↗

Devices for rapid diagnosis of Malaria: evaluation of prototype assays that detect Plasmodium falciparum histidine-rich protein 2 and a Plasmodium vivax-specific antigen.

The ParaSight F test was developed as a pioneer industry effort in the large-scale, process-controlled production of a device for the rapid diagnosis of malaria. This device performed well in field settings but was limited to the detection of a single malaria species, Plasmodium falciparum. The ParaSight F+V assay advanced upon the ParaSight F test format by incorporating a monoclonal antibody directed against a proprietary Plasmodium vivax-specific antigen, in addition to the antibody directed against P. falciparum histidine-rich protein 2, which was used in the ParaSight F assay. The modified assay was developed to add the capability to detect P. falciparum and P. vivax in a single-test-strip format. The present study evaluated three distinct ParaSight F+V prototypes with samples from symptomatic patients in regions of Thailand and Peru where malaria is endemic. Over a 2-year enrollment period (1998 and 1999), a total of 4,894 patients consented to participation in the study. Compared with the results for duplicate microscopic examinations of Giemsa-stained blood smears as the reference diagnostic standard, each successive prototype showed substantial improvement in performance. The final ParaSight F+V prototype, evaluated in 1999, had an overall sensitivity for detection of asexual P. falciparum parasites of 98%. The sensitivity of the device was 100% for P. falciparum densities of >500 parasites/ micro l, with a sensitivity of 83% for parasite densities of </=500/ micro l. The specificity for the exclusion of P. falciparum was 93%. For P. vivax, the overall sensitivity was 87% for the final 1999 prototype. The sensitivities calculated for different levels of P. vivax parasitemia were 99% for parasite densities of >5,000/ micro l, 92% for parasite densities of 1,001 to 5,000/ micro l, 94% for parasite densities of 501 to 1,000/ micro l, and 55% for parasite densities of 1 to 500/ micro l. The specificity for the exclusion of P. vivax was 87%. The areas under the receiver operating characteristic curves for the diagnostic performance of the assay for the detection of P. falciparum and P. vivax were 0.8907 and 0.8522, respectively. These findings indicate that assays for rapid diagnosis have the potential to enhance diagnostic capabilities in those instances in which skilled microscopy is not readily available.

Animals↗