Search PubMed⌕ Search

Biomedical subjects

J F Levine

Publications and source records attributed to J F Levine.

At least 19 recordsLinked to original sources

Bunyavirus infections in North Carolina white-tailed deer (Odocoileus virginianus).

We analyzed serum from white-tailed deer (Odocoileus virginianus) collected in southeastern North Carolina in 1991 for neutralizing antibodies to six mosquito-borne bunyaviruses (Lacrosse, Jamestown Canyon, Keystone,Cache Valley, Potosi, and Tensaw), including several of public health importance. Evidence was found for all six to be locally transmitted, although greatest seroprevalence was found for Potosi, Jamestown Canyon, and Cache Valley viruses.

Animals↗

An experimental chain of infection reveals that distinct Borrelia burgdorferi populations are selected in arthropod and mammalian hosts.

The prokaryotic, spirochaetal microorganism Borrelia burgdorferi is the causative agent of Lyme disease, an arthropod-borne disease of a variety of vertebrates and the most prevalent arthropod-borne disease of humans in the United States. In order to understand better the normal life cycle of B. burgdorferi, an experimental chain of infection was devised that involved multiple sequential arthropod and mammalian passages. By examining populations of B. burgdorferi emerging from different points in this infectious chain, we demonstrate that selection of B. burgdorferi populations peculiar to arthropod or vertebrate hosts is a property of at least one of the two ecologically distinct strains we examined. Distinct B. burgdorferi populations were identified using an antigenic profile, defined by a set of monoclonal antibodies to eight B. burgdorferi antigens, and a plasmid profile, defined by the naturally occurring plasmids in the starting clonal populations. These two profiles constituted the phenotypical signature of the population. In the strain exhibiting selection in the different hosts, transition from one host to another produced a striking series of alternating phenotypical signatures down the chain of infection. At the molecular level, the alternating signatures were manifested as a reciprocal relationship between the expression of certain antigenic forms of outer surface protein (Osp) B and OspC. In the case of OspC, the antigenic changes could be correlated to the presence of one of two distinctly different alleles of the ospC gene in a full-length and presumably transcriptionally active state. In the case of OspB, two alleles were again identified. However, their differences were minor and their relationship to OspB antigenic variation more complicated. In addition to the reciprocating changes in the antigenic profile, a reciprocating change in the size (probably the multimeric state) of a 9.0 kbp supercoiled plasmid was also noted. Selection of distinct populations in the tick may be responsible for the microorganism's ability to infect a wide range of vertebrate hosts efficiently, in that the tick might provide selective pressure for the elimination of the population selected in the previous host.

Amino Acid Sequence↗

Seroprevalence of Toxoplasma gondii and Trichinella spiralis in North Carolina black bears (Ursus americanus).

Serum samples from 143 hunter-killed black bears were collected during the 1996 and 1997 black bear hunting seasons in eastern North Carolina. All samples were tested for antibodies to Toxoplasma gondii by the modified agglutination test. Antibodies to T. gondii were present in 120 of 143 (84%) bears. Females had significantly higher titers than males (Wilcoxon rank sums test, P = 0.045), and titers increased with age (Jonckheere test, P = 0.01). Samples collected during 1996 (n = 79) were tested for antibodies to Trichinella spiralis by enzyme-linked immunosorbent assay. No samples were positive for antibodies to T. spiralis.

Age Distribution↗

Lizards as hosts for immature Ixodes scapularis (Acari: Ixodidae) in North Carolina.

Previously archived museum specimens of lizards collected throughout North Carolina were examined for Ixodes scapularis (Say). Lizards (n = 1,349) collected in 80 of North Carolina's 100 counties were examined. Lizards with ticks were collected in 23 (29%) of the 80 counties from which lizards were examined. I. scapularis was detected on 8.7% (n = 117) of the lizards and was the sole species of tick obtained from lizards. Immature ticks were most frequently found on the southeastern five-lined skink, Eumeces inexpectatus, and the eastern glass lizard, Ophisaurus ventralis. Larvae were most frequently found on the six-lined racerunner, Cnemidophorus sexlineatus. One C. sexlineatus harbored 177 larvae and 2 nymphs. Nymphs were most frequently observed on E. inexpectatus. The majority of counties (chi 2, P < 0.01) where ticks were found on lizards were in the Coastal Plain.

Animals↗

Tick-raccoon associations and the potential for Lyme disease spirochete transmission in the coastal plain of North Carolina.

Raccoons (Procyon lotor) were live-trapped and examined for ticks from July 1990 to July 1993 in the coastal plain of North Carolina on Marine Corps Base, Camp Lejeune, North Carolina (USA). Five species of ixodid ticks were found on 351 (78%) of 449 raccoons. Amblyomma americanum was the most abundant tick found on raccoons. Dermacentor variabilis, Ixodes texanus, and Ixodes scapularis were frequently collected, while Ixodes cookei were rarely collected from raccoons. Tick burdens were not affected by the age, sex, or trap location of captured raccoons. Ticks parasitizing raccoons had varying seasonal patterns of abundance. Amblyomma americanum were generally collected from raccoons year around, but infestation intensities were greatest in summer from June to September. Dermacentor variabilis adults were most abundant in mid-summer while peak numbers of larvae were collected in the fall. Infestation intensities of Ixodes texanus larvae were greatest in fall and winter months while nymphs were most abundant in winter and spring. No males were collected from raccoons, but females were most frequently collected in the spring and declined in abundance in the summer with no specimens collected in the fall or winter. Numbers of 1. scapularis adults appeared to reach peak numbers in the fall while larvae and nymphs were most abundant on raccoons in winter. Spirochetes, Borrelia burgdorferi, were identified in a small percentage (0.2%) of host-seeking A. americanum nymphs and adults, and I. scapularis adults by immunofluorescent antibody assays. Similarly, a small percentage (1.9%) of host-associated A. americanum, D. variabilis, I. texanus and I. cookei contained B. burgdorferi. Borrelia burgdorferi spirochetes were cultured from the blood of 23 (26%) of 87 raccoons.

Animals↗

The impact of water temperature on core body temperature of North American river otters (Lutra canadensis) during simulated oil spill recovery washing protocols.

Ten North American river otters (Lutra canadensis) were anesthetized with Telazol and instrumented with ingestable radiotelemetry temperature sensors for measuring core body temperature. The otters were then subjected to a washing protocol to simulate rehabilitation following an oil spill contamination. This protocol consisted of a 30-min wash in a 1:16 dilution of dishwashing liquid using either cold (24 degrees C) water or water near baseline core body temperature (38.4 degrees C), followed by a 30-min rinse with water of the same temperature, followed by 10 min of forced hot air drying. Core body temperatures of the otters washed in cold water fell at a median rate of 0.1 degrees C/min, whereas otters washed in warm water maintained stable core temperatures until the completion of the protocol, at which time their core temperatures began to drop at a similar rate. Core temperatures restabilized in both groups, and no statistical difference in core temperature between groups remained 180 min after initiation of the protocol. Efforts to examine the efficacy of supplemental squalene administration to speed the recovery of fur condition and waterproofing were unsuccessful because the washing protocol did not cause loss of coat waterproofing in 8 of the 10 subjects.

Aerosols↗

Reservoir competence of the southeastern five-lined skink (Eumeces inexpectatus) and the green anole (Anolis carolinensis) for Borrelia burgdorferi.

The reservoir competence of two lizard species, the southeastern five-lined skink (Eumeces inexpectatus) and the green anole (Anolis carolinesis), for Borrelia burgdorferi was evaluated. Skinks and anoles were exposed by needle inoculation or tick bite to B. burgdorferi. Xenodiagnosis with larval Ixodes scapularis and culture of tissues were used to asses infection and the ability of infected lizards to infect attached ticks. Both lizard species were susceptible to B. burgdorferi by both routes of exposure. Xenodiagnostic ticks acquired spirochetes while feeding on both species. One tick that dropped from a skink on the ninth day after exposure was infected. The remainder of xenodiagnostic ticks that acquired spirochetes fed three weeks after exposure of the lizards to the spirochete. Lizards remained infectious to attached ticks for at least five weeks. Overall, more than 20% of xenodiagnostic larvae fed on southeastern five-lined skinks acquired spirochetes. Individual skinks infected up to 34% of attached ticks. A smaller proportion of ticks feeding on green anoles became infected. Borrelia burgdorferi recovered from infected lizards retained their infectivity for mammalian hosts. The ability of the lizards to sustain a Borrelia infection and infect attached ticks suggests that they may play a role in the maintenance of spirochete transmission.

Animals↗

Experimental infection of the raccoon (Procyon lotor) with Borrelia burgdorferi.

The reservoir competence of the raccoon (Procyon lotor) for the Lyme disease spirochete (Borrelia burgdorferi) was evaluated in the laboratory during September 1991 to April 1993. Five raccoons were exposed to spirochete-infected (JD1 and Wisconsin 210 Wise strains) Ixodes scapularis nymphs (20/raccoon). A second feeding of spirochete-infected (Wisconsin 210 Wise strain) nymphs (20/raccoon) was performed with four of the original raccoons. Xenodiagnosis with cohorts of I. scapularis larvae (300/cohort) or nymphs (150/cohort) that were periodically placed on each animal was used to detect infection. We examined 1943 engorged ticks by a indirect immunofluorescence monoclonal antibody assay, but no spirochetes were detected. After exposure to spirochete-infected ticks, blood samples were collected at approximately weekly intervals and ear-skin biopsy samples were taken from each animal every third week. These tissues were placed in Barbour-Stoenner-Kelly media. Spirochetes were isolated in cultures of skin (wk 3, 5, 9, 81, and 83) and blood (wk 5, 8, 9, 11, and 12) of one raccoon and the skin (wk 28 and 31) of another raccoon. Antibody response of each animal was monitored through enzyme-linked immunosorbent assays and immunoblotting of blood serum against B. burgdorferi proteins. Except for one animal, raccoons did not have an antibody response until they were fed upon by a second cohort of infected I. scapularis nymphs. Based on Western blot analyses, raccoons exposed to B. burgdorferi via tick bite responded to the 31- (OspA) and 34-KDa (OspB) antigens. Response to other antigens varied among raccoons. Based on our results raccoons may be inefficient reservoirs for B. burgdorferi. Although some raccoons can become infected with B. burgdorferi, they may not transfer the infection to attached ticks.

Animals↗

Myocarditis in mice and guinea pigs experimentally infected with a canine-origin Borrelia isolate from Florida.

OBJECTIVE: To characterize the pathogenic potential of a unique Borrelia isolate obtained from a dog from Florida (FCB isolate). DESIGN: Prospective experimental infection. ANIMALS: 32 preweanling Swiss Webster mice and 12 adult male Hartley guinea pigs were injected intraperitoneally with 10(5) spirochetes. PROCEDURE: Mice were used as controls and blood recipients, and at 3- to 4-day intervals, 1 control mouse and 2 infected mice were necropsied, tissues were cultured, and a recipient mouse was inoculated with blood. Guinea pigs were randomized to 4 groups and inoculated intradermally with 10(0), 10(2), 10(3), or 10(4) spirochetes. For 48 days, clinical, hematologic, serologic, and microbiologic tests were performed on them, after which they were necropsied. RESULTS: In mice, spirochetemia was detectable between postinoculation days (PID) 3 and 13, and seroreactivity to homologous antigen was detectable during PID 10 through 31. Compared with control mice, infected mouse spleens were 2 to 3 times larger. Histologic lesions included lymphoid hyperplasia, neutrophilic panniculitis, epicarditis, and myocarditis, with intralesional spirochetes detected from PID 3 through 6. During PID 10 through 31, nonsuppurative epicarditis developed. Signs of illness and hematologic abnormalities were not observed in guinea pigs, despite isolating spirochetes from blood during PID 7 to 27. When necropsied on PID 48, histologic lesions included lymphoid hyperplasia and lymphocytic plasmacytic epicarditis. CONCLUSIONS: The FCB isolate causes spirochetemia, lymphoid hyperplasia, dermatitis, and myocardial injury in Swiss Webster mice and can be transmitted by blood inoculation. In Hartley guinea pigs, the isolate causes spirochetemia, lymphoid hyperplasia, and epicarditis. Documentation of disease in mice, guinea pigs, and, presumably, dogs raises the level of concern that the FCB isolate might be pathogenic for man and other animal species.

Animals↗

Polymerase chain reaction evidence of Ehrlichia chaffeensis, an etiologic agent of human ehrlichiosis, in dogs from southeast Virginia.

OBJECTIVE: To ascertain whether dogs are naturally infected with Ehrlichia chaffeensis. ANIMALS: 74 dogs from 5 animal shelters and 1 kennel in 3 cities and 3 counties in southeastern Virginia were tested during June 1991. PROCEDURE: Blood was drawn from 74 dogs; 73 were tested serologically for antibodies reactive to E chaffeensis and E canis, and 38 were tested for the presence of E chaffeensis, E canis, and E ewingii by polymerase chain reaction (PCR). Serologic testing by indirect fluorescent antibody assay. Nested PCR used Ehrlichia wide outside primers to detect initial products, followed by use of species-specific primers for identification. RESULTS: 28 (38.4%) dogs had a positive test result (minimum titer, > or = 1:64) for antibodies reactive to E chaffeensis, and 28 (38.4%) had a positive reaction to E canis. PCR analysis indicated that 8 (42.1%) dogs were positive for E chaffeensis and 6 dogs (31.6%) were positive for E ewingii. All dogs had negative results of the PCR test for E canis. CONCLUSION: Dogs are potential reservoirs of E chaffeensis. CLINICAL RELEVANCE: Canine E chaffeensis infection may be more prevalent than E canis or E ewingii infection in this region of the United States.

Animals↗

Reservoir competence of the rice rat (Rodentia: Cricetidae) for Borrelia burgdorferi.

The reservoir competence of the rice rat, Oryzomys palustris, for Borrelia burgdorferi is described. Infected Ixodes scapularis Say (I. dammini, Spielman, Clifford, Piesman & Corwin) nymphs were used to infect animals. Borrelia infection was diagnosed by xenodiagnostic feeding of noninfected I. scapularis larvae and by reisolation of the spirochetes from blood and other tissues. Rice rats acquired B. burgdorferi and maintained spirochete infection for 5-9 wk. B. burgdorferi were cultured from samples of skin and urinary bladders from all animals killed on day 21 (three rats), 35 (three rats), or 56 (three rats) after infection. The spirochetes were also detected in blood samples obtained 1 and 2 wk after exposure. Spirochetes that persisted for 5 wk in rice rats did not lose their infectivity for golden Syrian hamsters. The prepatent period for infecting xenodiagnostic ticks was 1 wk. Overall, 75.6% of I. scapularis larvae (n = 694) that fed on infected rice rats acquired B. burgdorferi. Prevalence of infection reached 83% in ticks that fed on tick-exposed animals during the 2nd-4th wk, 68% during the 5th wk, and 17.4% during the 9th wk. The duration of rice rat infectivity for ticks exceeded 2 mo. I. scapularis nymphs infected as larvae on rice rats transmitted B. burgdorferi. Taken together, these studies confirm the reservoir competence of the rice rat for B. burgdorferi.

Animals↗

Evaluation of factors associated with postoperative ileus in horses: 31 cases (1990-1992)

Medical records of horses that underwent surgical treatment for colic between 1990 and 1992 were reviewed. Horses with a pulse rate of > or = 60 beats/min or signs of abdominal pain, which were also accompanied by a volume of > 2 L of material that refluxed from the stomach during the postoperative period (excluding horses with anterior enteritis), comprised the postoperative ileus (POI) group. Horses that had < 2 L of material reflux during the postoperative period and survived > 3 days after surgery comprised the reference population. The association of preoperative and intraoperative clinical variables with development of POI was evaluated by use of logistic regression analysis. Of 148 horses, 117 were assigned to the reference population, and 31 (21%) developed POI. Multiple logistic regression analysis was used to determine that PCV, pulse rate, type and location of lesion detected during surgery, and serum glucose concentration were the most important variables associated with development of POI. Time of recovery from anesthesia to development of POI was 0.5 to 120 hours (median, 13 hours). Duration of POI was 1 to 7 days (median, 1 day). Four of 31 (13%) horses with POI died. Of 148 horses, only 10 (7%) died; however, 4 of the 10 (40%) deaths in the short-term postoperative period were attributable to POI.

Animals↗

Expression cloning of a human IL-12 receptor component. A new member of the cytokine receptor superfamily with strong homology to gp130.

A cDNA encoding a human IL-12R subunit was isolated by expression cloning. This subunit is a 662 amino acid type I transmembrane protein with an extracellular domain of 516 amino acids and a cytoplasmic domain of 91 amino acids. It is a member of the hemopoietin receptor superfamily and is most closely related over its entire length to gp130 and the receptors for granulocyte-CSF (G-CSF) and leukemia-inhibitory factor. When expressed in COS cells, this IL-12R subunit binds both human and murine IL-12 with an apparent affinity of 2 to 5 nM. The transfected COS cells express both monomers and disulfide-linked dimers or oligomers of the IL-12R subunit on their surface. However, unlike the IL-6-induced dimerization of gp130, the oligomerization of the IL-12R subunit is not dependent on binding of IL-12. Only the IL-12R subunit dimers/oligomers but not the monomers bind IL-12 with an affinity of 2 to 5 nM. A polyclonal antiserum raised against this receptor subunit specifically inhibits IL-12-induced proliferation of PHA-activated PBMC. The data are consistent with the hypotheses that 1) a dimer/oligomer of the cloned IL-12R subunit (IL-12R-beta) represents the low affinity IL-12 binding site identified on human lymphoblasts, 2) the cloned receptor subunit is involved in IL-12 signal transduction, and 3) an additional, as of yet unidentified subunit is required to generate a high affinity IL-12R complex.

Amino Acid Sequence↗

Natural infections with Borrelia spirochetes in two dogs from Florida.

Spirochetemia is a rarely reported observation in dogs. We describe the clinical, hematologic, and immunodiagnostic features of two spirochetemic dogs from northern Florida and the subsequent isolation and preliminary characterization of a Borrelia species from one dog in which culture of a sample for spirochetes was attempted. Results of polyacrylamide gel electrophoresis, monoclonal antibody testing, and PCR analysis indicate that the Florida isolate is not Borrelia burgdorferi, the only other member of the genus that has been isolated in Florida. Our findings also indicate that a member of the genus Borrelia potentially causes disease in dogs in Florida and that serologic cross-reactivity of the Florida canine Borrelia isolate with B. burgdorferi probably contributes to the inaccurate diagnosis of canine Lyme disease in the region.

Animals↗

Risk factors associated with acute pancreatitis in dogs: 101 cases (1985-1990).

The medical records of 101 dogs with acute pancreatitis, diagnosed on the basis of medical histories of acute vomiting, with serum lipase or amylase activity greater than the reference range, or with gross signs of pancreatitis at surgery or histopathologic evidence at necropsy, were evaluated to identify potential risk factors for the development of acute pancreatitis. Age, sex, and breed of dogs with acute pancreatitis were compared with those from a reference population of 100 dogs admitted for other medical emergencies during the same period. Analysis of multiple regression models indicated that dogs > 7 years old were at increased risk for acute pancreatitis. Spayed dogs and castrated male dogs had an increased risk, compared with that of sexually intact males. Similarly, terrier and nonsporting breeds appeared to be at higher risk of developing acute pancreatitis than were other breed types. Most dogs in this study (63/101) had intercurrent diseases, including diabetes mellitus (n = 14), hyperadrenocorticism (n = 12), chronic renal failure (n = 8), neoplasia (n = 17), congestive heart failure (n = 6), and autoimmune disorders (n = 5). Fourteen dogs had undergone anesthesia or surgery in the week before admission; only 3 had undergone abdominal procedures. Recent medication use was listed in 52 of 101 cases. Antibiotics (n = 18) and corticosteroids (n = 18) were most frequently described. Anticancer chemotherapeutic agents (n = 5) and organophosphate insecticides (n = 5) also were listed.(ABSTRACT TRUNCATED AT 250 WORDS)

Acute Disease↗

Vibrio damsela. A cause of fulminant septicemia.

A previously healthy 70-year-old man presented with a rapidly progressive and fulminant infection due to Vibrio damsela after suffering a knife cut while filleting bluefish at the New Jersey Shore. Despite appropriate antibiotic therapy and localized wound exploration, the patient died. To our knowledge, this is the first reported case of V damsela sepsis with simultaneous isolation of the organism from both blood and wound. We are reporting this case to heighten physicians' awareness of this infection and the importance of early management with antibiotics and surgical consultation.

Aged↗