Search PubMed⌕ Search

Biomedical subjects

A Spielman

Publications and source records attributed to A Spielman.

At least 55 records · Page 3Linked to original sources
PubMed1997

Competence of urban rats as reservoir hosts for Lyme disease spirochetes.

To determine whether urban rats serve efficiently as reservoir hosts for the agent of Lyme disease, we recorded the frequency of infection in nymphal Ixodes ricinus (L.) ticks that had fed as larvae on experimentally infected Norway rats, Rattus norvegicus (Berkenhout), or on black rats, R. rattus (L.), and evaluated the nidicolous venue of transmission. Subadult vector ticks attached readily to Norway rats as well as black rats and virtually all became infected in the course of feeding. Larval ticks detached when these nocturnally active hosts were at rest. Rats appeared to be competent reservoir hosts of Lyme disease spirochetes in a transmission cycle in urban sites.

Animals↗
PubMed1997

Heterogeneity of the internal transcribed spacer (ITS-2) region within individual deer ticks.

To determine whether nuclear rDNA sequences provide a useful means for assessing the structure of populations of Ixodes ticks, we compared variability among copies of an internal transcribed spacer (ITS-2) sequence within individual ticks to the variability between ticks. At least 4% of the nucleotides comprising this sequence vary among the copies present within individual ticks. ITS-2 diversity in each of two ticks is nearly half as great as that reported between ticks from geographically disparate populations. Because individual ticks retain ancestral polymorphism, ITS-2 variation does not accurately reflect descent relationships among these ticks. Sequencing single copies of PCR-amplified ITS-2 therefore does not permit assessment of the phylogenetic relationships among the I. ricinus-like ticks in eastern North America. We recommend caution in future analyses, and emphasize the importance of procedures designed to ensure that the many paralogous copies of the rDNA cistron have been sufficiently homogenized by concerted evolutionary processes. Such precautionary measures will make certain that phylogenetic trees based on these gene sequences reflect the phyletic relatedness of the biological species.

Animals↗
PubMed1997

The actigraph data analysis software: I. A novel approach to scoring and interpreting sleep-wake activity.

Decades of empirical observations have established the validity of actigraphy primarily in individuals without sleep disorders. Methodological problems encountered thus far coupled with the widespread use of actigraphy signal the need for concentrated efforts to establish a consensus regarding scoring procedures. Currently available scoring methods show less reliability in clinical populations. To address these issues two validation studies were conducted: one for individuals without sleep disorders and the other for patients diagnosed with insomnia. The results of these two studies using the Actigraph Data Analysis Software as the scoring method have shown that the described system is fairly precise. It can be used for actigraphs with different features and mode of operation and is applicable to individuals with insomnia. These findings corroborate previous research showing that actigraphy is a valid instrument for assessment of sleep and wakefulness.

Calibration↗
PubMed1997

The actigraph data analysis software: II. A novel approach to scoring and interpreting sleep-wake activity.

The widespread use of actigraphy has led to the recognition that a number of methodological issues have to be addressed to facilitate an increased acceptability of this relatively new method. These methodological issues include actigraph placement, reliability, and sensitivity, and the phenomenon known as the "first night effect." Our findings have demonstrated that actigraphy is a reliable instrument for assessment of sleep and wakefulness. In addition, actigraph placement and reliability do not constitute a significant methodological problem as no differences were found in all of these studies. We have also observed no first-night effects associated with sleep-wake monitoring with actigraphy.

Circadian Rhythm↗
PubMed1996

Concurrent Lyme disease and babesiosis. Evidence for increased severity and duration of illness.

OBJECTIVE: To determine whether patients coinfected with Lyme disease and babesiosis in sites where both diseases are zoonotic experience a greater number of symptoms for a longer period of time than those with either infection alone. DESIGN: Community-based, yearly serosurvey and clinic-based cohort study. SETTING: Island community in Rhode Island and 2 Connecticut medical clinics from 1990 to 1994. STUDY PARTICIPANTS: Long-term residents of the island community and patients seeking treatment at the clinics. MAIN OUTCOME MEASURES: Seroreactivity to the agents of Lyme disease and babesiosis and number and duration of symptoms. RESULTS: Of 1156 serosurvey subjects, 97 (8.4%) were seroreactive against Lyme disease spirochete antigen, of whom 14 (14%) also were seroreactive against babesial antigen. Of 240 patients diagnosed with Lyme disease, 26 (11%) were coinfected with babesiosis. Coinfected patients experienced fatigue (P = .002), headache (P < .001), sweats (P < .001), chills (P = .03), anorexia (P = .04), emotional lability (P = .02), nausea (P = .004), conjunctivitis (P = .04), and splenomegaly (P = .01) more frequently than those with Lyme disease alone. Thirteen (50%) of 26 coinfected patients were symptomatic for 3 months or longer compared with 7 (4%) of the 184 patients with Lyme disease alone from whom follow-up data were available (P < .001). Patients coinfected with Lyme disease experienced more symptoms and a more persistent episode of illness than did those (n = 10) experiencing babesial infection alone. Circulating spirochetal DNA was detected more than 3 times as often in coinfected patients as in those with Lyme disease alone (P = .06). CONCLUSIONS: Approximately 10% of patients with Lyme disease in southern New England are coinfected with babesiosis in sites where both diseases are zoonotic. The number of symptoms and duration of illness in patients with concurrent Lyme disease and babesiosis are greater than in patients with either infection alone. In areas where both Lyme disease and babesiosis have been reported, the possibility of concomitant babesial infection should be considered when moderate to severe Lyme disease has been diagnosed.

Adolescent↗
PubMed1996

Mefloquine insusceptibility of malaria in Thailand not promoted by nonregulated drug-use.

To determine whether the nonregulated use of antimalaria drugs on the Thai-Cambodian border promoted the recent loss of mefloquine sensitivity by Plasmodium falciparum parasites, we identified the drugs consumed there by gem miners. Of those drug concoctions that were self-administered, five contained chloroquine, one contained primaquine and bactrim and two merely contained analgesics. Local nonregulated healers prescribed orally administered concoctions containing chloroquine, quinine, tetracycline or primaquine for patients suffering mild illness. They administered parenteral chloroquine for severely ill patients and quinine when malaria was life-threatening. Certain of these healers prescribed fansimef, but only infrequently and after 1990. Because gem miners appear not to have had informed access to mefloquine before 1990, we conclude that the loss of antimalaria efficacy of this drug on the Thai-Cambodian border during the late 1980s was independent of its nonregulated use.

Adult↗
PubMed1996

Etiology of the acrodermatitis chronica atrophicans lesion in Lyme disease.

Spirochete diversity in acrodermatitis chronica atrophicans lesions in a closely defined central European site was compared to that in the local vector population, in human erythema migrans lesions, and in cerebrospinal fluid by amplifying and sequencing a segment of the gene of outer surface protein A directly from sampled tissues. Borrelia garinii, Borrelia afzelii, and Borrelia burgdorferi acutely infect human skin and invade internal tissues. Only B. afzelii, however, is associated with acrodermatitis chronica atrophicans lesions, persisting chronically where the skin has atrophied.

Acrodermatitis↗
PubMed1996

Characteristics of Lyme disease spirochetes in archived European ticks.

To determine whether the characteristics of the Lyme disease spirochete (Borrelia burgdorferi) in Europe may have changed during the past century, DNA was amplified from archived Ixodes ricinus ticks. Tick DNA could be amplified, even when ticks had been stored under museum conditions for nearly a century. Spirochetal DNA was detected by polymerase chain reaction in 6 ticks preserved for as long as a century; the oldest was collected in 1884. Borrelia garinii, which predominates in modern ticks in the region, infected 3 of these older ticks, and the presently infrequent B. burgdorferi sensu stricto infected 2. These data indicate that residents of Europe have been exposed to diverse Lyme disease spirochetes at least since 1884, concurrent with the oldest record of apparent human infection.

Animals↗
PubMed1996

Risk of urban Lyme disease enhanced by the presence of rats.

To determine whether Norway rats contribute to the risk of human Lyme disease in a central European city park, densities of endemic rodents were compared as were feeding densities of vector ticks and prevalence of infection by the Lyme disease spirochete. Only Norway rats and yellow-necked mice were abundant, and three times as many mice as rats were present. More larval ticks fed on rats than on mice, and far more nymphs engorged on the rats. All rats but only about half of the mice infected ticks. Each rat was more infectious than each infectious mouse. Infected rats were distributed throughout the city. Spirochetes infected about a quarter of the questing nymphal ticks. The capacity of rats to serve as reservoir hosts for the Lyme disease spirochete, therefore, increases risk of infection among visitors to this and other urban parks.

Animals↗
PubMed1996

Comparison of PCR with blood smear and inoculation of small animals for diagnosis of Babesia microti parasitemia.

The specific diagnosis of babesiosis, which is caused by the piroplasm Babesia microti, is made by microscopic identification of the organism in Giemsa-stained thin blood smears, detection of babesial antibody in acute-and convalescent-phase sera, or identification of the organism following the injection of patient blood into laboratory animals. Although rapid diagnosis can be made with thin blood smears, parasites are often not visualized early in the course of infection. PCR is a new, rapid diagnostic technique for the detection of Babesia spp. that has not yet been systematically evaluated. We conducted a blinded study of the sensitivity, specificity, and reproducibility of the PCR-based test with patients with babesiosis and a group of asymptomatic subjects residing in a region in southern New England where babesiosis is enzootic. Among 19 patients with recent babesial illness, we found that PCR was as sensitive and specific as the use of Giemsa-stained blood smears and inoculation of hamsters. Among asymptomatic subjects, the PCR result was positive for 3 persons with recent babesial infection and was negative for 41 persons without previous babesial infection. We conclude that the B. microti PCR procedure is sufficiently sensitive, specific, and reproducible for use in the diagnosis of acute babesiosis.

Animals↗
PubMed1996

Efficacy of immunoglobulin M serodiagnostic test for rapid diagnosis of acute babesiosis.

To evaluate the efficacy of an immunoglobulin M indirect immunofluorescent-antibody procedure for diagnosing acute babesiosis, we tested patients with acute babesiosis from a site in New England where the disease is enzootic. The sensitivity of the test was 91%, the specificity was 99%, the positive predictive value was 86%, and the negative predictive value was 99%. This B. microti immunoglobulin M indirect immunofluorescent-antibody procedure is sufficiently sensitive, specific, and reproducible for use in the routine clinical diagnosis of acute babesiosis.

Acute Disease↗
PubMed1996

Minority Oral Health Research Center. Improving oral health and expanding opportunities.

To address the glaring problems of disparity in oral health and representation in the manpower pool of oral health researchers, the National Institute for Dental Research (NIDR) of the National Institutes of Health established Regional Research Centers for Minority Oral Health. The Minority Oral Health Research Center at New York University College of Dentistry, a collaboration between the college and the Fosyth Dental Center, is one of four centers established by the NIDR in the United States to improve oral health for all Americans and to enhance accessibility of research careers for minority individuals. This article describes the center's progress to date, expected outcomes and its call for partners to improve minority oral health.

Child↗
PubMed1996

Determination of sleep and wakefulness with the actigraph data analysis software (ADAS).

Current evidence has shown that, overall, actigraphy is an excellent tool for unobtrusive documentation of sleep/wake activity in normal individuals. However, a number of methodological issues remain to be resolved to warrant its use in clinical research. In this paper, we report the results of a study aimed at the development of a new scoring software that can accurately identify sleep and wakefulness. Using total sleep time as an index of comparison, the software was optimized on a calibration sample and prospectively tested on a validation sample. A strong correlation coefficient (r = 0.93, p < 0.008), with an average discrepancy value of 10 minutes, was observed for the calibration sample. The application of the optimal software to the validation sample revealed an even higher correlation coefficient (r = 0.97, p < 0.0001), with an average discrepancy value of 12 minutes.

Adult↗
PubMed1995

Distribution of the Ixodes ricinus-like ticks of eastern North America.

We analyzed the geographic distribution of the Ixodes ricinus-like ticks in eastern North America by comparing the mitochondrial 16S rDNA sequences of specimens sampled directly from the field during the 1990s. Two distinct lineages are evident. The southern clade includes ticks from the southeastern and middle-eastern regions of the United States. The range of the northern clade, which appears to have been restricted to the northeastern region until the mid-1900s, now extends throughout the northeastern and middle-eastern regions. These phyletic units correspond to northern and southern taxa that have previously been assigned specific status as Ixodes dammini and Ixodes scapularis, respectively. The expanding range of I. dammini appears to drive the present outbreaks of zoonotic disease in eastern North America that include Lyme disease and human babesiosis.

Animals↗
PubMed1995

Vaccination against Lyme disease caused by diverse Borrelia burgdorferi.

Diversity and mutations in the genes for outer surface proteins (Osps) A and B of Borrelia burgdorferi sensu lato (B. burgdorferi), the spirochetal agent of Lyme disease, suggests that a monovalent OspA or OspB vaccine may not provide protection against antigenically variable naturally occurring B. burgdorferi. We now show that OspA or OspB immunizations protect mice from tick-borne infection with heterogeneous B. burgdorferi from different geographic regions. This result is in distinct contrast to in vitro killing analyses and in vivo protection studies using syringe injections of B. burgdorferi as the challenge inoculum. Evaluations of vaccine efficacy against Lyme disease and other vector-borne infections should use the natural mode of transmission and not be predicated on classification systems or assays that do not rely upon the vector to transmit infection.

Animals↗