HIGH-FREQUENCY CHEST WALL COMPRESSION (HFCWC)

ABSTRACT: In healthy individuals, clearance of secretions from the respiratory tract is accomplished primarily through ciliary action. In young children the number of alveoli within the respiratory tract is also lesser and shorter and organisms may move quickly down the respiratory tract triggering more extensive involvement. Postural drainage and percussion are usually taught to family members so that the therapy may be continued at home when needed in cases of chronic disease. Since this highly labour-intensive activity requires the daily intervention of a trained caregiver, it may lead to poor compliance with the recommended treatment plan. The air-pulse generator rapidly inflates and deflates the vest, compressing and releasing the chest wall up to 20 times per second. The vibratory forces of these devices are thought to lower mucus viscosity. High-frequency airway clearance (HFCWC) assist devices generate either positive or negative trans-respiratory pressure excursions. The typical treatment lasts 20-30 minutes, and consists of short periods of compression at different frequencies, separated by coughing. The use of HFCWO compared to CPT also produced a significant improvement in blood inflammation parameter. Key Words: respiratory tract, High-frequency airway clearance (HFCWC), short periods of compression.

CHEMICAL ECOLOGY OF SHALLOW WATER OCTOCORALS. OCCURRENCE OF CEMBRANOLIDES IN PSEUDOPLEXAURA AND EUNICEA

Gorgonians of the genus Pseudoplexaura, from a variety of geographical locations, yield crassin acetate as the major cembranolide. The cembranolides found in Eunicea collected at different locations vary. Eunicin is found in Eunicea mammosa from Bimini, and from a number of other locations. Its position isomer Jeunicin, has been found in the Eunicea from Jamaica. Eunicea from Curacao yields an epimer ot eunicin, Cueunicin, while that from Puerto Rico yields Eupalmerin acetate, and Peunicin occurs in Eunicea collected off Panama. The cembranolides are toxic to various aquatic organisms. They inhibit ciliary action in the ciliate Tetrahymena pyriformis, and in the larvae of the nudibranch Phestilla sibogae.

Functional morphology of the esophagus of the tropical house gecko Hemidactylus mabouia (Squamata: Gekkonidae)

In order to understand the biology of species that easily establish themselves in new environments, morphological studies are essential. This study aimed to describe the esophageal functional morphology ofHemidactylus mabouia, indicating adaptations to food habits. Seventeen adult specimens were used for anatomical, topological, histological, and histochemical analyses. Histological sections were stained with toluidine blue or submitted to techniques for identification of argyrophil and argentaffin endocrine cells, proteins, and glycoconjugates. The esophagus ofH. mabouiais a tubular straight-lined organ, and its anterior portion is dilated, facilitating the swallowing of whole prey. The esophageal epithelium is pseudostratified, containing cells secreting neutral and acid mucins. At the esophagogastric transition, we found a mixture of this epithelium with a simple prismatic epithelium secreting neutral mucins. The esophagus lamina propria is thin and non-glandular. At the esophagogastric transition it becomes thick and filled by branched simple acinous glands, with cells secreting neutral mucins, zymogenic cells, and argentaffin endocrine cells, with no argyrophil cells. The mucins protect the esophageal mucosa and lubricate the channel to facilitate the passage of food, while pepsinogen in the stomach increases the levels of pepsin for proteolytic digestion. The muscular tunica is made up of smooth muscle cells. Ciliary action, in addition to muscle contractions, facilitates the swallowing of small prey.

Fertilization, Implantation, and Endocrinology of Pregnancy

The complex and coordinated set of events leading to sperm and egg maturation and transport in the female genital tract that culminates in fertilization is one of the most remarkable phenomena in nature. This set of events is followed by the equally important unique processes of implantation, fetal maturation, and parturition. The hormonal changes that regulate these events are dependent on the close interaction of the fetal-placental-maternal unit. Just before ovulation, the egg, which has been arrested in the diplotene stage, completes the first meiotic division and forms the first polar body. The second meiotic division starts at the time of ovulation but ends only after fertilization by a sperm. The process of egg maturation is regulated through a closely interrelated set of hormonal events, most notably involving follicle-stimulating hormone (FSH), luteinizing hormone (LH), and estrogen. At the time of ovulation the fimbria of the oviduct are closely applied to the surface of the ovary. The extruded oocyte and adherent granulosa cells, known as the cumulus oophorus, is collected by the ciliated fimbrial end of the fallopian tube. The transport of the egg into the end of the fallopian tube occurs within minutes and is regulated primarily by ciliary action. The cumulus cells are able to communicate with one another via a network of intercellular bridges through the zona pellucida to the perivitelline space. The cumulus cells have also been reported to play a role in nutrition and maintenance of the ovum. There are three different stages of passage of the ovum through the fallopian tube. The first stage includes the transfer of the ovum from the fimbriated end of the fallopian tube until the egg reaches and is retained at the ampullary-isthmic junction. The ampullary-isthmic junction is a functional block but is not a clearly defined anatomical structure. The ovum remains at this junction for 1–2 days, during which time fertilization occurs.

Feeding behavior of Frontonia leucas (Ehrenberg) (Protozoa, Ciliophora, Hymenostomatida) under different environmental conditions in a lotic system

The objective of this study was to record and describe the morphological changes and the ingestion mechanisms of Frontonia leucas (Ehrenberg, 1833) according to the food type and to relate the food ingested with the different environmental conditions in a lotic system, namely São Pedro stream, located in the municipality of Juiz de Fora, Minas Gerais, Brazil. We sampled three points on a monthly basis from August 2002 to June 2003, each of which receiving different levels of untreated sewage. We prepared culture media for the ciliate specimens containing filtered water from each point and the types of food observed inside F. leucas (cyanobacteria, diatoms, desmids and testate amoebas). We observed the ingestion mechanisms of F. leucas in vivo, under a phase contrast optical microscope, using instantaneous sampling and sequence sampling as behavior observation methods, noting the following parameters: dissolved oxygen concentration, pH, conductivity and water temperature. We noted the F. leucas ciliates ingesting diatoms and desmids at collection point 1 and filamentous cyanobacteria, testate amoebas (Arcella and Centropyxis) and rotifers at points 2 and 3. The present work records for the first time the ingestion of testate amoebas of the genus Centropyxis by F. leucas. We noted five ingestion mechanisms by F. leucas while feeding on cyanobacteria and testate amoebas of the genus Centropyxis, three of these related to the ciliary action and two involving physical changes in the cytoplasm. For ingestion of diatoms, desmid (Closterium) and Arcella, the mechanisms involving ciliary action alone were sufficient for ingestion, since these preys are smaller than the ciliate under study. The autecological data registered for F. leucas were 1.98-8.01 mg l-1 O2, pH 6.9-8.73, 58-390 µS/cm and 19.5-26.2ºC, confirming its ample ecological valence.

A hydrozoan, Zanclella bryozoophila n.gen., n.sp. (Zancleidae), symbiotic with a bryozoan, with a discussion of the Zancleoidea

A new genus and species of hydroid, Zanclella bryozoophila, symbiotic with bryozoans is described. The colony is polymorphic and highly integrated with its bryozoan host. The gastrozooids have one or, rarely, two tentacles; dactylozooids are without tentacles. The medusa stage is reduced to liberable eumedusoids produced on the hydrorhiza, and has exumbrellar nematocyst chambers. The cnidome of both stages consists of stenoteles and macrobasic euryteles. General morphology and cnidome structure place this newly described form in the Zancleidae. A new genus is recognized on the basis of polymorphism of the hydroid and reduction of the medusa stage. The association with the bryozoan is described as commensal. Hydranths appear to feed on particles gathered by ciliary action of the bryozoan lophophore, and the hydrorhiza is surrounded by the bryozoan skeleton. The advantage of this relationship to the bryozoan is believed to be protection, effected by the nematocysts of the hydroid.

The feeding mechanism of Yoldia ( ═ Aequiyoldia ) eightsi (Courthouy)

The protobranch bivalve mollusc Yoldia eightsi Courthouy is both a deposit feeder (on mud) and a suspension feeder (on diatoms in the ventilatory streams, which are trapped on the ctenidia). The species has a similar anatomy to other Yoldia species, but is a more shallow burrower which adopts a more horizontal shell orientation than the vertically burrowing Yoldia limatula and Yoldia ensifera . Although capable of feeding on the surface layers of mud by extending its palp proboscides outside the partly buried shell, Yoldia eightsi spends most of its time feeding while totally buried. To do this, sediment is taken into the mantle cavity by opening the shell valves, or by foot movements. The sediment is moved by ciliary action to the posterior part of the mantle cavity where it forms a compact, mucus-coated sediment slug. The slug is repeatedly sorted largely by the palp proboscides, fine material being transferred to the mouth via the palps. Sorting appears to be done on a simple size–density basis, with large, dense particles being rejected. After sorting, the inorganic fraction of the slug is expelled through the inhalant siphon (‘pseudofaecal plume’). Expulsions occur every 6–35 min. True faeces (‘faecal plume’) are expelled much more frequently in the expiratory bursts of water from the exhalant siphon. Pseudofaecal output is about 170 times the faecal output (on a dry mass basis), suggesting that Yoldia eightsi ingests 0.6% of processed material.