Peritrophic envelopes of Lutzomyia spinicrassa (Diptera: Psychodidae).

The secretion, morphology, and chemical composition of the peritrophic envelope were studied in the phlebotomine sand fly, Lutzomyia spinicrassa Morales, OsornoMesa, Osorno & Hoyos, a suspected vector of Leishmania braziliensis in Colombia and Venezuela. Viewed under light microscopy, the envelope matured rapidly and could be dissected from the blood bolus as early as 12 h and until 36 h after feeding; subsequently it began to degrade. The envelope was initially a closed sac around the blood meal, but opened posteriorly in most flies by 6 h.

Autoradiographic localization of opioid receptors in vocal control regions of a male passerine bird (Junco hyemalis).

Previous studies have found opioid peptide-like immunoreactivity in avian vocal control regions, but whether these regions contain receptors for opioid peptides has not been examined. To address this question, we used quantitative in vitro autoradiography to determine the anatomical distribution and to measure the densities of mu, delta, and kappa opioid receptors in vocal control regions (area X, higher vocal center, and nucleus intercollicularis) of adult male dark-eyed juncos (Junco hyemalis). To evaluate whether opioid receptor densities in these regions depend on the activity of the reproductive system, we also measured these densities in birds collected during the spring, summer, and fall.

Oxyfuel in Alaska: use of interleukins to monitor effects on the immune system.

During a 4-week period in late November and early December 1992, blood samples from individuals exposed to auto emissions derived from oxyfuel were analyzed. Effects on the immune system were measured by monitoring plasma interleukin 6 (IL-6) levels in a total of 22 subjects at the beginning and the end of the workday. After approximately 8 h of workplace exposure, mean levels of IL-6 of 2.

Evidence for recovery of body mass and haptoglobin values of river otters following the Exxon Valdez oil spill.

Levels of blood haptoglobin (Hp) and interleukin-6 immunoreactive protein (IL-6 ir) were significantly elevated in river otters (Lutra canadensis) inhabiting oiled areas of Prince William Sound, Alaska (USA) following the Exxon Valdez oil spill in 1989. By May and June 1992, however, such differences were not apparent. Mean body mass of otters, adjusted for sex, age-class, and total length with analysis of covariance, differed between oiled and non-oiled areas from 1990 to 1992, but were nearly identical by May and June 1992.

Life cycle of Leishmania major (Kinetoplastida: Trypanosomatidae) in the neotropical sand fly Lutzomyia longipalpis (Diptera: Psychodidae).

The development of Leishmania major Yakimoff & Schokhor in the New World sand fly Lutzomyia longipalpis (Lutz & Neiva) was examined by light and electron microscopy. In this unnatural host, parasites differentiated into 10 typical morphological forms, multiplied at three sites, migrated anteriorly and established in the foregut, and attached to gut surfaces. In the blood meal, amastigotes divided and transformed into two successive dividing, stumpy promastigote stages.

Leishmania differentiation in natural and unnatural sand fly hosts.

Leishmania differentiation in the gut of phlebotomine sand flies was evaluated based on five light and electron microscopic studies of natural (Leishmania panamensis/Lutzomyia gomezi, Leishmania chagasi/Lutzomyia longipalpis) and unnatural (Leishmania mexicana/Lutzomyia abonnenci, Leishmania panamensis/Phlebotomus papatasi, Leishmania major/Lutzomyia longipalpis) life cycles. In the bloodmeal, transformation of amastigotes into stumpy promastigotes occurred before or during division. Further division in pairs or rosettes resulted in the development of spatulate and/or elongate nectomonad (free-swimming) promastigotes.

Identification of a haptoglobin-hemoglobin complex in the Alaskan Least Cisco (Coregonus sardinella).

The hemoglobin and a hemoglobin binding protein have been characterized in the Arctic fish (Coregonus sardinella). The evolutionary significance of the hemoglobin and plasma protein differences between fish and mammals is still unresolved. Blood samples from the Alaskan Least Cisco were separated into plasma and hemoglobin fractions and the proteins in these fractions were analyzed both by alkaline agarose gel electrophoresis, by isolelectric focusing, and by capillary electrophoresis.

Oral rabies vaccination of arctic foxes (Alopex lagopus) with an attenuated vaccine.

Arctic foxes were immunized with the SAG1 oral rabies vaccine. The effectiveness was determined by the serological response and by the survival to a challenge dose of rabies virus from an Alaskan fox. Vaccine virus was isolated from saliva 1 h after the liquid vaccine was placed directly into the mouth but not subsequently (tested up to 1 week postvaccination).

Interactions between marine bacteria and dissolved-phase and beached hydrocarbons after the Exxon Valdez oil spill.

Turnover times for toluene in Resurrection Bay after the Exxon Valdez grounding were determined to be decades, longer than expected considering that dissolved hydrocarbons were anticipated to drift with the current and stimulate development of additional hydrocarbon-utilizing capacity among the microflora in that downcurrent location. These turnover times were based on the recovery of 14CO2 from added [14C]toluene that was oxidized. The concentrations of toluene there, 0.

Thermoregulation, growth, and reproduction in Alaskan collared lemmings: role of short day and cold.

To assess factors controlling seasonal thermoregulatory and reproductive changes, collared lemmings (Dicrostonyx groenlandicus) were exposed for 16 wk to long day (LD, 22 h light: 2 h dark) and warm (15 +/- 3 degrees C), LD and cold (1 +/- 0.5 degrees C), short day (SD, 4 h light: 20 h dark) and warm, SD and cold or acclimatized to outdoor winter conditions (OUT). Hair length and color, body mass, and food intake were monitored weekly.

A heparin-binding protein from neuroblastoma cells: immunological comparison to beta-amyloid precursor protein.

1. beta-Amyloid precursor protein cross-reactive polypeptides were detected in the membrane extracts of a mouse neuroblastoma cell line, NB41A3. Four immunoreactive polypeptide bands were observed on western blots of a cell membrane extract.

A review of echinoderm oogenesis.

This review of the anatomical, histological, biochemical, and molecular biological literature on echinoderm oogenesis includes the entire developmental history of oocytes; from their inception to the time they become ova. This is done from a comparative perspective, with reference to members of the five extant echinoderm classes; crinoids, holothurians, asteroids, ophiuroids, and echinoids. I describe the anatomy and fine structure of the echinoderm ovary, with emphasis on both the cellular relationships of the germ line cells to the somatic cells of the inner epithelium, and on the neuromuscular systems.

Neuroendocrine, behavioral, and morphological changes associated with the termination of the reproductive period in a natural population of male rough-skinned newts (Taricha granulosa).

Male rough-skinned newts (Taricha granulosa) were collected from the same natural population every second week from early April to mid-June. They were either field-tested for their sexual responsiveness or used to measure the plasma concentrations of androgens and corticosterone, the brain concentrations of immunoreactive (ir) gonadotropin-releasing hormone (GnRH) and arginine vasotocin (AVT), and morphological parameters. During the experimental period, the percentage of sexually responsive males gradually declined from 100 to 4%, concurrent with a decrease of plasma concentrations of androgens, but not corticosterone.

Pseudomonas cepacia 2,2-dialkylglycine decarboxylase. Sequence and expression in Escherichia coli of structural and repressor genes.

A 3969-base pair PstI-PstI fragment of Pseudomonas cepacia DNA containing the gene for the pyridoxal 5'-phosphate dependent 2,2-dialkylglycine decarboxylase (pyruvate) (EC 4.1.1.

Prosimian hemoglobins--V. The primary structures of the alpha-I, alpha-II and beta-hemoglobin chains of Hapalemur griseus, with a note on the classification of Microcebus.

1. The duplicated adult hemoglobins were isolated from a mature Hapalemur griseus and the constituent chains prepared. Sequence analysis of the isolated alpha-globins showed that the alpha-I and alpha-II chains differed by a glycine for lysine substitution at position 15.

Effects of sodium and temperature on naloxone binding in brain tissues of a urodele amphibian.

1. Partially purified brain membranes obtained from male rough-skinned newts (Taricha granulosa) were used to determine the effects of NaCl and temperature on the specific binding of the opioid receptor antagonist [3H]naloxone. 2.

Retinopetal cells exist in the optic tectum of steelhead trout.

The existence of retinopetal cells in the tectum of various teleost fishes as been claimed by several authors. Others, however, have been unable to verify such observations and attribute the findings of retrogradely labelled tectal cells to methodological problems. In this study cobalt-lysine and HRP have been used as neuronal tracers.

Immunization of arctic foxes (Alopex lagopus) with oral rabies vaccine.

Arctic foxes (Alopex lagopus) were successfully immunized against rabies using an orally-administered, liquid SAD-BHK21 live virus vaccine in a sausage bait. Immunization was determined by serologic response and by resistance to challenge with an arctic rabies virus strain. Virus was not shed in saliva following oral vaccination, indicating that arctic foxes would not infect other foxes after ingesting this vaccine.

Glucose turnover and defense of blood glucose levels in Arctic fox (Alopex lagopus).

1. Glucose utilization was assessed in fed and fasted arctic fox, maintained on a diet similar in composition to food available in the wild. 2.