Survey of distribution of substance P, vasoactive intestinal polypeptide, cholecystokinin, neurotensin, Met-enkephalin, bombesin and PHI in the spinal cord of cat, dog, sloth and monkey

Levels of substance P (sP), peptide-histidine-isoleucine (PHI), vasoactive intestinal polypeptide (VIP), cholecystokinin (CCK), neurotensin (NT), bombesin (BOM) and methionine-enkephalin (Met-Enk) like immunoreactivity were measured in cat, dog, primate and sloth cervical, thoracic, lumbar and sacral dorsal and ventral horns and dorsal root ganglia. The levels of peptides in the cat sacral cord and the principal peaks of immunoreactivity on a 10-60% acetonitrile gradient on a C18 reverse phase high performance liquid chromatography (HPLC) were sP (sP1-11: 369 ng/g), PHI (PHI: 271 ng/g), VIP (VIP1-28: 210 ng/g), Met-Enk (Met1-5 and extended forms: 257 ng/g), BOM (BOM1-10 and GRP1-27: 20 ng/g), CCK (CCK-8: 15 ng/g) and NT (NT1-13: 10 ng/g). Consideration of the rostrocaudal levels revealed an approximately even distribution with the exception of VIP and PHI which showed sacral/cervical ratios of 79 and 63. For sP, Met-Enk and BOM dorsal/ventral ratios were greater than 1 at all spinal levels. For VIP, PHI and CCK these ratios were greater than 1 only in the sacral cord. Dorsal root ganglion (DRG) levels of sP, VIP, PHI were readily measurable in single ganglia and covaried with the respective levels in the dorsal cord. Pooled samples of spinal ganglia and the trigeminal ganglia revealed that the relative levels of peptide immunoreactivity were: sP (25 ng/g); VIP (26 ng/g); PHI (28 ng/g); Met-Enk (6 ng/g); CCK (2 ng/g); NT (1 ng/g); and BOM (1 ng/g).

Dimensional analysis and dynamic response characterization of mammalian peripheral vestibular structures

Extensive morphometric measurements were made on the vestibular system of the rabbit ( Oryctulagus cuniculus), the gerbil (Meriones unguiculatus), the chinchilla (Chinchilla laniger ), and the squirrel monkey (Saimiri sciureus) from serial sections of temporal bones. Additionally, a more limited set of measurements were also completed on the owl monkey (Aotus trivirgatus), the Capuchin monkey (Cebus sp.), the harp seal ( Pagophilus groenlandicus Erxleben , 1777), and the two-toed sloth ( Choloepus sp.). The following measurements were made: 1) radius of curvature (R) of each membranous semicircular canal (herein called semicircular duct-see nomenclature in Nomina Anatomica (1968) ), 2) cross-sectional diameter of the ducts and the osseous semicircular canals, and 3) some pertinent morphometrics of the cristae ampullares and the utricle. In all species studied 1) the radii of curvature of the three semicircular ducts are dissimilar, with that of the lateral duct being as small as, or smaller than, those of the anterior and posterior ducts; 2) R for the anterior duct is largest in the harp seal and the rabbit; 3) the canal and duct dimensions are largest in the Capuchin and squirrel monkeys, the two-toed sloth, and the harp seal, and smallest in the gerbil; 4) the proportion of otic fluid "space" that is occupied by endolymph shows a ranking of gerbil greater than rabbit greater than two-toed sloth greater than chinchilla = owl monkey greater than squirrel monkey greater than Capuchin monkey greater than harp seal; and 5) the gross ampullary and utricular dimensions are largest in the harp seal and smallest in the gerbil. These measurements were used for determining the time constants describing semicircular-canal dynamics in the Steinhausen (1931, 1933) and Oman -Marcus (1980) equations.

Epidemiological patterns of cutaneous leishmaniasis in Panama. I. Epidemics among small groups of settlers

Epidemic of cutaneous leishmanniasis among a small group of people established in a Panamanian forested area was studied. The first settlers arrived in June 1971, and by June 1973 there were 37 persons, 33 of whom had no previous history of the disease. Epidemiological surveys were made in June 1973 and March 1974. The disease developed in 14 (42.4%) of the 33 susceptible persons by June 1973, with an exposure time ranging from one to 14 months. The last case occurred in April 1973, and no new cases were observed during the ensuing 11 months. Two (15.4%) of 13 dogs examined were found with cutaneous leishmaniasis, but none of 41 feral mammals studied, mainly terrestrial rodents, was infected. Four leishmanial strains characterized, three from patients and one from a dog, were identified as Leishmania braziliensis. Phlebotomine sandfly population composition was studied and the probable vectors involved in the transmission to man were determined.

Epidemiological patterns of cutaneous leishmaniasis in Panama. III. Endemic persistence of the disease

Endemic persistence of cutaneous leishmaniasis is described in El Aguacate, a community established in the forest of central Panama about 75 years ago. Physiographic pecularities partially isolate El Aguacate from other villages in the region. Some of the original forest environment has been preserved and man-biting species of phlebotomine sandflies were abundant as was the two-toed sloth, Choloepus hoffmanni, the principal reservoir host of Leishmania braziliensis in Panama. The inhabitants, as well as their dogs, were examined for natural leishmaniasis in 1969 and 1973. Mammals and phlebotomine sandflies were collected from 1968 to 1973 in a search for reservoir hosts and potential vectors of the disease. Similar studies were undertaken in two nearby villages during 1968 and 1969. L. braziliensis has persisted for many years in El Aguacate, and infection is acquired during childhood. Dogs also were found naturally infected, and the two-toed sloth showed yearly infection rates up to 47.8%. Parasites were demonstrated from a night monkey, Aotus trivirgatus.

Infrequency of gross skin lesions among Panamanian forest mammals with cutaneous leishmaniasis

Natural leishmanial infections among feral mammals in the Republic of Panama were studied in relation to gross skin alterations. Three dermatotropic species of Leishmania, L. braziliensis, L. mexicana and L. hertigi, isolated from 230 sylvatic animals of 5 mammalian orders were involved. In 205 (89%) of the cases there were no gross skin alterations. Cryptic infections of all three leishmanial species among wild animals were confirmed by culture and hamster inoculation. This type of infection was always present in the sloths, Choloepus hoffmanni and Bradypus infusatcus, infected with L. braziliensis and in the porcupine, Coendou rothschildi, infected with L. hertigi. Suggestive skin alterations were encountered in 10 (4%) of infected animals. Only 15 (7%) of infected animals exhibited typical leishmanial lesions. It was possible to correlate skin depigmentation with the course of leishmanial infection in one animal, a young kinkajou, Potos flavus.

Potencial evocado auditivo no córtex do bicho preguiça

Foram estudadas as respostas evocadas no córtex do bicho preguiça (Bradypus tridactylus) mediante estimulação auditiva, o que permitiu delimitar, abaixo do sulco supra-silviano, duas áreas auditivas (A-I e A-II), com latência para o início da fase positiva de 20 ms (19-25 ms) e 30 ms (27-35 ms), respectivamente. Com anestesia barbitúrica profunda, foram obtidas respostas de longa latência (65-110 ms para o início da fase positiva), distribuídas difusamente no córtex, com predominância no pólo anterior do cérebro. Foi estudada a interação de um som contínuo sôbre a resposta evocada em AI, assim como a resistência da resposta evocada em A-I à asfixia. Alguns animais apresentaram resposta evocada em A-I, mesmo após 25 minutos de asfixia.

Spinal Reflexes and Seizure Patterns in the Two-Toed Sloth

In striking contrast to the seizure patterns of other animals, the electroshock seizure of the sloth consists of weak extension followed by tonic flexion and terminal clonus. A similar pattern is seen with direct spinal cord stimulation. Strychnine produces a pure flexor convulsion. In the spinal sloth, painful stimulation of one foot causes extension at some joints of that limb and strong flexion at all joints of the contralateral limb.