The Simons Observatory: Cryogenic half wave plate rotation mechanism for the small aperture telescopes

We present the requirements, design, and evaluation of the cryogenic continuously rotating half-wave plate (CHWP) for the Simons Observatory (SO). SO is a cosmic microwave background polarization experiment at Parque Astronómico de Atacama in northern Chile that covers a wide range of angular scales using both small (⌀0.42 m) and large (⌀6 m) aperture telescopes. In particular, the small aperture telescopes (SATs) focus on large angular scales for primordial B-mode polarization. To this end, the SATs employ a CHWP to modulate the polarization of the incident light at 8 Hz, suppressing atmospheric 1/f noise and mitigating systematic uncertainties that would otherwise arise due to the differential response of detectors sensitive to orthogonal polarizations. The CHWP consists of a 505 mm diameter achromatic sapphire HWP and a cryogenic rotation mechanism, both of which are cooled down to ∼50 K to reduce detector thermal loading. Under normal operation, the HWP is suspended by a superconducting magnetic bearing and rotates with a constant 2 Hz frequency, controlled by an electromagnetic synchronous motor. We find that the number of superconductors and the number of magnets that make up the superconducting magnetic bearing are important design parameters, especially for the rotation mechanism's vibration performance. The rotation angle is detected through an angular encoder with a noise level of 0.07 μrad s. During a cooldown process, the rotor is held in place by a grip-and-release mechanism that serves as both an alignment device and a thermal path. In this paper, we provide an overview of the SO SAT CHWP: its requirements, hardware design, and laboratory performance.

Composite reflective/absorptive IR-blocking filters embedded in metamaterial antireflection-coated silicon

Infrared (IR)-blocking filters are crucial for controlling the radiative loading on cryogenic systems and for optimizing the sensitivity of bolometric detectors in the far-IR. We present a new IR filter approach based on a combination of patterned frequency-selective structures on silicon and a thin (25-75 μm thick) absorptive composite based on powdered reststrahlen absorbing materials. For a 300 K blackbody, this combination reflects ∼50% of the incoming light and blocks >99.8% of the total power with negligible thermal gradients and excellent low-frequency transmission. This allows a reduction in the IR thermal loading to negligible levels in a single cold filter. These composite filters are fabricated on silicon substrates, which provide excellent thermal transport laterally through the filter and ensure that the entire area of the absorptive filter stays near the bath temperature. A metamaterial antireflection coating cut into these substrates reduces in-band reflections to below 1%, and the in-band absorption of the powder mix is below 1% for signal bands below 750 GHz. This type of filter can be directly incorporated into silicon refractive optical elements.

Systematic effects from an ambient-temperature, continuously rotating half-wave plate

We present an evaluation of systematic effects associated with a continuously rotating, ambient-temperature half-wave plate (HWP) based on two seasons of data from the Atacama B-Mode Search (ABS) experiment located in the Atacama Desert of Chile. The ABS experiment is a microwave telescope sensitive at 145 GHz. Here we present our in-field evaluation of celestial (Cosmic Microwave Background (CMB) plus galactic foreground) temperature-to-polarization leakage. We decompose the leakage into scalar, dipole, and quadrupole leakage terms. We report a scalar leakage of ∼0.01%, consistent with model expectations and an order of magnitude smaller than other CMB experiments have been reported. No significant dipole or quadrupole terms are detected; we constrain each to be <0.07% (95% confidence), limited by statistical uncertainty in our measurement. Dipole and quadrupole leakage at this level lead to systematic error on r ≲ 0.01 before any mitigation due to scan cross-linking or boresight rotation. The measured scalar leakage and the theoretical level of dipole and quadrupole leakage produce systematic error of r < 0.001 for the ABS survey and focal-plane layout before any data correction such as so-called deprojection. This demonstrates that ABS achieves significant beam systematic error mitigation from its HWP and shows the promise of continuously rotating HWPs for future experiments.

Modulation of cosmic microwave background polarization with a warm rapidly rotating half-wave plate on the Atacama B-Mode Search instrument

We evaluate the modulation of cosmic microwave background polarization using a rapidly rotating, half-wave plate (HWP) on the Atacama B-Mode Search. After demodulating the time-ordered-data (TOD), we find a significant reduction of atmospheric fluctuations. The demodulated TOD is stable on time scales of 500-1000 s, corresponding to frequencies of 1-2 mHz. This facilitates recovery of cosmological information at large angular scales, which are typically available only from balloon-borne or satellite experiments. This technique also achieves a sensitive measurement of celestial polarization without differencing the TOD of paired detectors sensitive to two orthogonal linear polarizations. This is the first demonstration of the ability to remove atmospheric contamination at these levels from a ground-based platform using a rapidly rotating HWP.

Generation and ex vivo expansion of HTLV-1 specific CD8+ cytotoxic T-lymphocytes for adoptive immunotherapy

CD8(+) cytotoxic T-lymphocytes (CTLs) have been proven, in multiple animal models, to be the most powerful antiviral and antitumor components of the immune system. We have developed a protocol to activate and expand tumor and virus peptide-specific CD8(+) T-lymphocytes from the peripheral blood of healthy, human trophic leukemia virus-1 (HTLV-1) seronegative human leucocyte antigen (HLA)-A*0201 individuals. A combination of density-based separation and culture conditions was employed to isolate dendritic cells (DCs), which are the most potent antigen-presenting cells (APCs), and T-lymphocytes. The DCs were pulsed with HLA-A*0201 binding peptides and cultured with autologous T-lymphocytes to generate peptide-specific CTLs. The CTLs were generated against a nine-amino-acid peptide from the Tax protein of HTLV-1. The CTLs were expanded according to a restimulation schedule employing peptide-pulsed autologous monocytes and low-dose interleukin-2 (IL-2) to numbers in excess of 100 x 10(6) cells following 5 weeks of culture. Expanded cells contained primarily CD3(+) T-cells, of which CD8(+) T-lymphocytes constituted greater than two-thirds of the cell population. Obtained CTLs exhibited potent antigen-specific lysis of peptide-pulsed target cells in a dose-dependent fashion in in vitro (51)Cr release cytotoxicity assay. This antigen-specific killing was shown to be HLA class I restricted and mediated by CD8(+) T-lymphocytes. Since the T-lymphocytes were obtained from HTLV-1 seronegative donors, the generation of peptide-specific CTLs represents reliable and reproducible elicitation of a primary immune response in vitro against naive antigens and subsequent expansion of generated CTLs for adoptive immunotherapy. (c) 1996 John Wiley & Sons, Inc.

The impact of climate change on mental health (but will mental health be discussed at Copenhagen?)

Climate change will shortly be assuming centre stage when Copenhagen hosts the United Nations Climate Change Conference in early December 2009. In Copenhagen, delegates will discuss the international response to climate change (i.e. the ongoing increase in the Earth's average surface temperature) and the meeting is widely viewed as the most important of its kind ever held (http://en.cop15.dk/). International agreement will be sought on a treaty to replace the 1997 Kyoto Protocol. At the time of writing it is not known whether agreement will be reached on the main issues of reducing greenhouse gas emissions and financing the impacts of climate change, and it appears that the impact of climate change on mental health is unlikely to be on the agenda. We discuss here how climate change could have consequences for global mental health and consider the implications for future research and policy.

Psychotherapies for hypochondriasis

BACKGROUND

Hypochondriasis is associated with significant medical morbidity and high health resource use. Recent studies have examined the treatment of hypochondriasis using various forms of psychotherapy.

OBJECTIVES

To examine the effectiveness and comparative effectiveness of any form of psychotherapy for the treatment of hypochondriasis.

SEARCH STRATEGY

1. CCDANCTR-Studies and CCDANCTR-References were searched on 7/8/2007, CENTRAL, Medline, PsycINFO, EMBASE, Cinahl, ISI Web of Knowledge, AMED and WorldCat Dissertations; Current Controlled Trials meta-register (mRCT), CenterWatch, NHS National Research Register and clinicaltrials.gov; 2. Communication with authors of relevant studies and other clinicians in the field; 3. Handsearching reference lists of included studies and relevant review articles, and electronic citation search in ISI Web of Knowledge for all included studies.

SELECTION CRITERIA

All randomised controlled studies, both published and unpublished, in any language, in which adults with hypochondriasis were treated with a psychological intervention.

DATA COLLECTION AND ANALYSIS

Data were extracted independently by two authors using a standardised extraction sheet. Study quality was assessed independently by the two authors qualitatively and using a standardised scale. Meta-analyses were performed using RevMan software. Standardised or weighted mean differences were used to pool data for continuous outcomes and odds ratios were used to pool data for dichotomous outcomes, together with 95% confidence intervals.

MAIN RESULTS

Six studies were included, with a total of 440 participants. The interventions examined were cognitive therapy (CT), behavioural therapy (BT), cognitive behavioural therapy (CBT), behavioural stress management (BSM) and psychoeducation. All forms of psychotherapy except psychoeducation showed a significant improvement in hypochondriacal symptoms compared to waiting list control (SMD (random) [95% CI] = -0.86 [-1.25 to -0.46]). For some therapies, significant improvements were found in the secondary outcomes of general functioning (CBT), resource use (psychoeducation), anxiety (CT, BSM), depression (CT, BSM) and physical symptoms (CBT). These secondary outcome findings were based on smaller numbers of participants and there was significant heterogeneity between studies.

AUTHORS' CONCLUSIONS

Cognitive therapy, behavioural therapy, cognitive behavioural therapy and behavioural stress management are effective in reducing symptoms of hypochondriasis. However, studies included in the review used small numbers of participants and do not allow estimation of effect size, comparison between different types of psychotherapy or whether people are "cured". Most long-term outcome data were uncontrolled. Further studies should make use of validated rating scales, assess treatment acceptability and effect on resource use, and determine the active ingredients and nonspecific factors that are important in psychotherapy for hypochondriasis.

Psychiatric morbidity and cognitive representations of illness in chronic daily headache

OBJECTIVES

We studied patients with chronic daily headache (CDH) attending a headache clinic. Our hypothesis was that patients with anxiety or depression would have poorer functional status and differing cognitive representations of illness than would those without psychiatric morbidity.

METHODS

The sample consisted of 144 consecutive new patients. Patients underwent a semistructured interview and completed a prospective headache diary, the Hospital Anxiety and Depression Scale (HADS) and other health-related questionnaires.

RESULTS

Sixty patients (42%) were probable cases of anxiety or depression on the basis of their HADS score. These HADS-positive cases had longer, more severe headaches, were more worried about them, were more functionally impaired and believed that their illness would last longer. Principal components analysis revealed that the HADS-positive cases believed that psychological factors play a role in their headaches.

CONCLUSIONS

Psychological morbidity is high amongst CDH patients who attend specialist clinics. In addition to identifying those with high levels of psychological distress, the HADS can be used to predict those likely to have worse headaches and poorer functional ability.

Effects of inactivity on glycolytic capacity of single skeletal muscle fibers in adult and aged rats

The purpose of this study was to determine the effects of inactivity on lactate dehydrogenase (LDH) enzyme activity (expressed in nmol/g dry weight x hour) in single skeletal musclefibers from the soleus muscle in adult and aged rats. Fourteen 12-month-old andfifteen 30-month-old Fisher 344 Brown Norway F1 Hybrid rats were randomly assigned to control, 1 week of hindlimb unweighting (HU1), or 2 weeks of hindlimb unweighting (HU2). With age, a significant decrease in LDH enzyme activity occurred in type I skeletal muscle fibers (29.5%, P < 0.05). Following HU2, individual type I skeletal muscle fibers from the 12-month-old animals showed a 33.3% increase in LDH activity. In contrast, individual type I fibers from the aged animals showed a 50.0% increase after HU1. In conclusion, the baseline levels of LDH activity were significantly less in aged versus adult rats. The timing of the skeletal muscle adaptation to inactivity was different between young and old animals, such that the older animals responded to inactivity before the younger animals. These biochemical changes may have an impact on the fatigability of the muscle following inactivity. Thefindings indicate that treatment during bed rest for the older adult may be different than that for the younger adult.

An anti-cytokine bioactivity assay for interferons-alpha, -beta and -omega

Interferons-alpha and -beta (IFN-alpha and -beta) are cytokines that are widely known to induce potent anti-viral activity. However, it has become increasingly apparent that IFN-alpha and -beta exert a variety of other biological effects, including anti-tumour and immunomodulatory activities and are increasingly used clinically to treat a range of malignancies, myelodysplasias and autoimmune diseases, e.g., IFN-beta for multiple sclerosis. The most widely used bioassays for the IFNs are based on their anti-viral activity, but these do not predict the biological activity of the IFNs in anti-tumour and immunomodulatory therapies. Thus, we have developed anti-cytokine-based bioassays that may be more reflective of such activity and which have several advantages over existing anti-viral bioassays. The anti-cytokine bioassay is based on the ability of IFN-alpha, -beta and -omega to inhibit granulocyte-macrophage-colony-stimulating factor (GM-CSF) induced proliferation of the erythroleukaemic cell line TF-1. This assay can take only 24 h, is sensitive to 200 fg (0.04 IU) IFN-alpha or -beta and 100 fg (0.02 IU) IFN-omega and is able to detect down to these levels in serum or plasma samples. The usefulness of anti-cytokine bioassays for IFN-alpha, -beta and -omega is not restricted to the GM-CSF/TF-1 cell format and other alternatives are available, such as erythropoietin (EPO)/TF-1 cells and EPO/UT-7-EPO cells. These assays can be made specific for each of the IFNs by including neutralising antibodies in the bioassay.

An antiproliferative bioassay for interleukin-4

Interleukin-4 (IL-4) is currently being used for therapeutic intervention in a wide range of malignant diseases as an antitumour agent. Although bioassays have been developed that measure the proliferative capacity of IL-4, none measure the antiproliferative activity of this molecule. We have developed a simple, sensitive bioassay for human IL-4 based on the ability of this cytokine to inhibit the proliferation of the human lung carcinoma line, CCL-185, an easy to maintain, cytokine independent, cell line. It is rapid, reproducible and sensitive, able to detect 2 pg/ml IL-4. The assay is completely unresponsive to all other interleukins from IL-2 to IL-12, to the colony stimulating factors and transforming growth factor beta and is 100-fold less sensitive to interferon-alpha, tumour necrosis factor-alpha, IL-1 beta and IL-13. The assay can be made completely specific for IL-4 by including specific neutralizing antibodies for IL-4 and is suitable for the estimation of IL-4 in both plasma and serum samples.

A sensitive human cell line based bioassay for megakaryocyte growth and development factor or thrombopoietin

We have developed a simple, rapid, sensitive bioassay for megakaryocyte growth and development factor (MGDF) or thrombopoietin (TPO) based on its ability to stimulate the proliferation of the human megakaryoblastic cell line MO7e. The bioassay takes only 24 h, is reproducible and sensitive to less than 10 pg/ml of MGDF. It can be made specific for MGDF by including neutralizing antibodies specific for MGDF, and is suitable for detection of MGDF in both plasma and serum samples.

Evidence for a signaling role for the alpha chains of granulocyte-macrophage colony-stimulating factor (GM-CSF), interleukin-3 (IL-3), and IL-5 receptors: divergent signaling pathways between GM-CSF/IL-3 and IL-5

In the present study, we have used a human erythroleukemia cell line, TF-1, that proliferates in response to granulocyte macrophage colony stimulating factor (GM-CSF), interleukin-3 (IL-3), and interleukin-5 (IL-5) to investigate the role of receptors for these cytokines in signal transduction mechanisms involved in proliferative responses. The receptors for GM-CSF, IL-3, and IL-5 each possess a cytokine specific alpha subunit, but all three share a common beta chain. Using an immunoblotting system designed to detect phosphotyrosine containing proteins and a permeabilized cell system to detect rapid changes in phosphate turnover on proteins, we show that while GM-CSF and IL-3 use tyrosine phosphorylation to mediate mitogenic signal transduction, IL-5 uses tyrosine dephosphorylation in its signaling pathway. The use of different signaling pathways by these cytokines can be confirmed in a biologic system whereby the proliferation induced in culture by GM-CSF and IL-3 is inhibited by tyrosine kinase inhibitors, but that induced by IL-5 is enhanced. Conversely, GM-CSF- and IL-3-induced proliferation is stimulated by a tyrosine phosphatase inhibitor, yet IL-5-induced proliferation is inhibited. Inhibitors of protein kinase C inhibit IL-3- and GM-CSF-, but not IL-5-induced proliferation. We suggest that, because all these cytokines share the identical beta chain of their receptors, the cytokine specific alpha chain mediates the linkage of each receptor to the individual biochemical signal transduction pathways responsible for the different biologic activities of these cytokines.

Activated phenotype in neutrophils and monocytes from patients with primary proliferative polycythaemia

AIM

To investigate whether monocytes and neutrophils from patients with primary proliferative polycythaemia (PPP) exhibit increased expression of markers of cell activation and, if so, whether they are associated with the phagocytic activity of these cells and concentrations of circulating cytokines.

METHODS

Expression of CD11b, CD14, CD18, and CD64 on monocytes and neutrophils was assessed by flow cytometry. Phagocytosis was analysed using immunoglobulin opsonised Escherichia coli. Serum concentrations of granulocyte colony stimulating factor (G-CSF), granulocyte-macrophage CSF (GM-CSF) and macrophage CSF (M-CSF) were determined by bioassays, and interferon-gamma (IFN-gamma) by enzyme linked immunosorbent assay (ELISA).

RESULTS

Patients with PPP (n = 18), when compared with normal subjects (n = 10), had increased percentages of CD64+ monocytes (52% v 36%) and neutrophils (42% v 11%) and of CD14+ neutrophils (36% v 18%). Monocytes from patients with PPP exhibited increased expression of CD64 (47 v 26) and of CD11b (65 v 36). These abnormalities were not found in patients with secondary (n = 8) or apparent (n = 13) polycythaemia. The percentage of neutrophils undergoing phagocytosis was higher in patients with PPP (mean 64%; n = 6) than in normal subjects (mean 42%; n = 5). G-CSF, GM-CSF and IFN-gamma concentrations in patients' serum samples were comparable with normal; M-CSF was not detected in any of the samples. There was no correlation between cytokine concentrations and the expression of CD11b, CD14, CD18, and CD64 on patients' phagocytes.

CONCLUSIONS

Increased expression of CD11b and CD64 by monocytes, increased percentages of CD14+ and CD64+ neutrophils and the high phagocytic activity of neutrophils suggests that these cells are activated in vivo in patients with PPP. The phenotypic changes of PPP phagocytes were not associated with increased concentrations of circulating cytokines and probably reflect intrinsic abnormalities within the neoplastic PPP clone.

Millimeter-submillimeter wavelength filter system

We describe the design, fabrication, measurement, and performance of a set of cryogenic millimetersubmillimeter wavelength filters used in a balloonborne bolometric radiometer. The set contains single resonant mesh grids used as dichroic beam splitters, resonant meshes in a double quarter-wave configuration, a commercial inductive grid filter, and high-frequency blocking filters. The resultant system has passbands at λ = 1.73, 1.05, 0.61, 0.44 mm with δλ/λ = 0.23, 0.23, 0.12, 0.06. Limits on high-frequency leakage are deduced from laboratory measurements and from the analysis of flight data. The filter set response to three different sources of radiation is presented to show the method and limitations of our characterization. The key element of the filter system is a resonant periodic array of cross-shaped holes etched in thin aluminum. We give an empirical scaling law for the resonant wavelength as a function of structure parameters for aluminum on 25-µm-thick Mylar. Plots of the transmittance for normally incident radiation and the transmittance and reflectance for a 45° incident radiation are presented.

Final heights in 45,X Turner's syndrome with spontaneous sexual development. Review of European and American reports

STUDY OBJECTIVE

To assess the effect of endogenous estrogen secretion on the final heights of patients with 45,X Turner's syndrome.

DESIGN

European and American reports of patients with 45,X Turner's syndrome and spontaneous sexual maturation in which final heights were available were analyzed and compared with existing norms for untreated patients with Turner's syndrome. Subgroups of patients were compared as a means of distinguishing low from normal endogenous estrogen exposure, and the effect of the age of menarche was assessed.

PATIENTS

Twenty-three cases were collected, including eight who became pregnant. One had full somatic maturation but did not menstruate. RESULTS OF ANALYSES: Mean height of all 23 patients was 140.8 cm +/- 8.07 (s.d.) vs 143.1 cm +/- 6.0 (p = 0.035) for literature norms for Turner's syndrome. Mean height of those who achieved pregnancy was 138.6 cm +/- 8.21 (p = 0.035 vs literature norm); of those with normal gonadotropins 137.5 cm +/- 6.03; and of those with high gonadotropins 139.2 cm +/- 1.44 (p = 0.374). Age of menarche was available in 21 and showed no correlation with final height.

CONCLUSIONS

Physiological and subphysiological endogenous secretion of estrogen in Turner's syndrome does not increase final height, suggesting that even low-dose exogenous estrogen would not increase ultimate stature in these patients.

Resonant cryogenic chopper

We describe the design, construction, and performance of a resonant cryogenic chopper that operates at 4.2 K. The chopper is mechanically and thermally robust; it can occult a 2.54-cm aperture at 4.5 Hz while dissipating ~1 mW. Both the stator and rotor magnetic fields are controllable to allow for performance optimization and to help in measuring any possible interference effects. Data on long-term amplitude stability are presented.

Hypothalamic-pituitary-ovarian function in menstruating women with Turner syndrome (45,X)

The hypothalamic-pituitary-ovarian hormone secretion patterns were evaluated in two women with 45,X Turner syndrome, spontaneous sexual development, and monthly menstrual periods. Each women had serum gonadotropin and sex steroid determinations during two or more menstrual cycles. During the follicular phase of a menstrual cycle, both women received 100 micrograms gonadotropin-releasing hormone (GnRH) s.c., and serum LH and FSH responses were determined. In addition, one woman collected daily overnight urine specimens for 40 consecutive days, spanning two menstrual periods, for the measurement of LH, FSH, estriol, and free progesterone. The randomly measured hormone results showed low serum progesterone concentrations during luteal phases, consistent with the interpretation of anovulation or inadequate corpus luteum function. At the time of the GnRH stimulation tests, baseline serum FSH concentrations and FSH responses to GnRH were within normal limits, whereas baseline LH levels and LH responses to GnRH were low. The pituitary gonadotropin secretion patterns were more consistent with patterns seen during early puberty than in the perimenopausal state. This interpretation was further confirmed by the urinary excretion patterns of gonadotropins, which were not significantly elevated. Furthermore, the urinary hormone profiles revealed that, although the intermenstrual period was of normal length, the follicular phase was prolonged, with normal levels of LH, FSH, and estriol excreted. The menstrual cycle studied was ovulatory but had a short luteal phase. The hormone results indicated that the dysgenetic ovary of women with 45,X Turner syndrome is capable of producing sufficient quantities of sex steroids and other regulatory factors to maintain gonadotropin secretion patterns that are reminiscent of early puberty.(ABSTRACT TRUNCATED AT 250 WORDS)

Inheritance of uncomplicated hypospadias

Isolated first-degree hypospadias in three generations of one family and in two generations of two families is reported and the literature reviewed. Pedigree information suggests autosomal-dominant, sex-limited inheritance in these cases although other inheritance patterns are possible. Mendelian transmission of hypospadias may be more frequent than commonly believed and implies that the abnormality is potentially definable in molecular terms.

Direct immunofluorescence tests with counterstains for detection of Chlamydia psittaci in infected avian tissues

Different methods of preparation and serological evaluation of rabbit globulins for use in fluorescent antibody conjugate and different methods of counterstaining with fluorescent antibody tests were evaluated for detection of Chlamydia psittaci in infected turkey tissues. The agar gel precipitin reaction was that chosen for testing and selecting antiserums to be used for fluorescein isothiocyanate conjugation. The fluorescent antibody staining was most pronounced with conjugate made from globulins precipitated with ammonium sulfate. A direct fluorescent antibody method with Evans blue counterstain correctly identified "coded" specimens of C. psittaci-infected and noninfected turkey air sacs. However, naphthalene black was superior to Evans blue as a counterstain when infected pericardial sacs were tested.

Legionnaires' disease: antigenic peculiarities, strain differences, and antibiotic sensitivities of the agent

Paired sera from victims of Legionnaires' disease showed, in many cases, significant rises in immunoglobulin G antibodies to both the causative agent (LA) of Legionnaires' disease and Chlamydia psittaci, but concurrent rises in immunoglobulin M antibodies only against LA. Guinea pigs experimentally infected with LA likewise responded with antibodies to both C. psittaci and LA. Guinea pigs infected with LA also reflected significant differences in antigenic makeup and in pathogenicity among four strains of LA examined. In antibiotic studies, rifampin was 200 times more effective than erythromycin and 17,000 times more effective than tetracycline in plaque reduction tests of LA in monolayer cultures of primary chick embryo cells. An isolate of LA recovered from a healthy person was compared with three isolates from persons with fatal infections.

Comparison of direct and modified direct complement-fixation and agar-gel precipitin methods in detecting chlamydial antibody in wild birds

Detection of chlamydial antibody in serums of wild birds was compared for the following methods: direct complement-fixation (DCF), modified DCF (MDCF), and agar-gel precipitin (AGP). The birds species used were great-tailed grackles (Cassidix mexicanus), common grackles (Quiscalus quiscula), brown-headed cowbirds (Molothrus ater), bronzed cowbirds (Tangavius aeneus), and mourning doves (Zenaida macroura). The birds were either inoculated with an isolate of Chlamydia psittaci obtained originally from turkeys or kept as uninoculated cagemates. DCF detected antibody in most inoculated common grackles, mourning doves, and brown-headed cowbirds. It was unreliable, however, for great-tailed grackles and bronzed cowbirds inoculated intramuscularly. MDCF method detected antibody in all inoculated birds except 1 mourning dove, and gave higher titers than did DCF. AGP detected antibody in all inoculated brown-headed cowbirds and all mourning doves, 1 inoculated and 1 exposed great-tailed grackle, and none of the other 2 species. Chlamydiae were apparently transmitted to the uninoculated great-tailed and common grackles and mourning doves, for antibody was detected by all 3 methods in these species kept as uninoculated cagemates.

Optimal macroculture method for studying mitogenic stimulation of turkey lymphocytes

This report describes a method for culturing turkey lymphocytes in disposable, unwashed glass test tubes with Morton closures and for recovering lymphocytes on fiber glass filters with a cell harvester made of common laboratory equipment for assay of mitogenic stimulation. Optimal conditions for culture were established.

Observations on the involvement of wildlife in an epornitic of chlamydiosis in domestic turkeys

In an investigation of potential wildlife reservoirs of Chlamydia psittaci at the site of an acute, highly fatal epornitic of chlamydiosis in domestic turkeys in Texas, various species of wild birds and rodents were captured and tested for chlamydial serum antibodies and chlamydiae in their tissues. Thirteen (65%) of 20 blackbirds (Agelaius sp), 4 (44%) of 9 killdeer (Oxyechus vociferus), 3 (27%) of 11 sparrows (Passer sp) and 1 of 4 mourning doves (Zenaidura macroura) were seropositive, but chlamydiae were not isolated from their tissues. Two of 3 rats (2 cotton rats, Sigmodon hispidus, and 1 roof cat, Rattus rattus) were seropositive, but 7 gophers (Citellus sp), 1 ground squirrel (Tamias sp), an opossum (Didelphis virginiana), and a domestic cat (Felis domesticus) were seronegative; however, chlamydiae were recovered from the livers and spleens of the opossum and domestic cat, both of which had been observed scavenging carcasses of turkeys dead of chlamydiosis. Cultures of these isolants were inoculated experimentally into turkeys and produced lesions of chlamydiosis that were indistinguishable from those caused by the strain originally recovered from diseases turkeys on the premises. Nine of 50 domestic goats quartered near the diseased turkeys were tested, and all were seropositive.

Naturally occurring and experimentally induced mycoplasmal arthritis of cattle

Mycoplasma agalactiae subsp. bovis strain Iowa 1136 was isolated from synovial fluids of a clinical case of arthritis in cattle on pasture in Iowa. When given to calves and cows by intra-articular or intravenous injection, it caused severe and persistent joint infections with fever, lameness, and swelling of the affected joints, plus synovitis, tendonitis, and fibrinous-purulent synovial fluids of high protein content. Intramammary administration of the organism caused severe mastitis. Calves nursing the cows developed severe mycoplasmal arthritis.

An epornitic of fatal chlamydiosis (ornithosis) in South Carolina turkeys

An unusual epornitic of fatal chlamydiosis occurred in a flock of 10,283 domestic turkeys in South Carolina. Total mortality over a 2-week period was 483 birds (4.7% of the flock). The principal gross lesion was severe pericarditis, but there was little or no airsacculitis, an observation at variance with many previous reports of chlamydiosis. Furthermore, an unusually heavy infestation of the turkeys with sanguivorous black flies (Simulium slossonae and S congareenarum) was observed at the time of the epornitic, an occurrence that may have permitted rapid transmission of chlamydiae between turkeys in the affected flock. The strains of Chlamydia psittaci isolated from naturally infected turkeys caused pericarditis and heptopathy as well as occasional airsacculitis, with a 41% mortality in intravenously (IV) inoculated turkeys. Turkeys inoculated intramuscularly (IM) or intraperitoneally (IP) did not die; however, airsacculitis was observed in more than 85% of turkeys inoculated intraperitoneally or exposed to infection by pen contact with inoculated turkeys. The strain was highly infectious but not lethal by the latter method of transmission. The strain was similar to other virulent chlamydiae isolated from turkeys, in that small numbers of the organism caused fatal infection in guinea pigs when inoculated IP.

Detection of chlamydial antibodies in animal sera by double diffusion in gel

Postinoculation sera collected from pigeons, turkeys, guinea pigs, sheep, a calf, a rabbit, and a horse experimentally infected with various strains of Chlamydia psittaci yielded a high incidence of positive reactions when tested by double diffusion in gel. Antigen was a deoxycholate extract of SA-2 strain of C. trachomatis. Good correlation was obtained with results of complement fixation tests, whereas double diffusion in gel was less sensitive. Immunoelectrophoresis of the antigen revealed presence of two antigens in the extract.