Maintenance of Weight Loss: A Needs Assessment

This study identified facilitators and obstacles to maintenance of weight loss following a very-low-calorie-diet and behavior modification program. A survey was mailed to a random sample of 178 program completers and received a 61% response rate; the most frequent follow-up period was more than 2 years. Twenty-nine percent reported weighing the same (within 10 lbs) or less than the end of their participation in the treatment program (maintainers), while 71% reported their present weight was a mean of 65% higher than their initial weight loss (regainers). Maintainers were significantly more likely to report engaging in regular aerobic exercise, attending a maintenance support group, and confidence in their ability to manage their weight in the future, while regainers were more likely to report stress and motivation as frequent weight management obstacles. Respondents consistently identified the need for low/no cost ongoing support. Maintainers and relapsers reported similar challenges in managing their weight, yet with different results, suggesting the need to identify subgroups for which different post-treatment support options could be applied.     

Growth response of marigold (Tagetes erecta L.) to inoculation withGlomus mosseae,Trichoderma aureoviride andPythium ultimum in a peat-perlite mixture

The interactions between the mycorrhizal fungusGlomus mosseae, the plant pathogenPythium ultimum, and a pathogen-antagonistTrichoderma aureoviride in the rhizosphere ofTagetes erecta (marigold) were studied for their effects on plant growth in a peat-perlite substrate. Mycorrhizal fungus inoculation protected the plant againstP. ultimum, since both phytomass production and foliar development were higher in mycorrhizal plants.T. aureoviride had no effect on nonmycorrhizal plants in the presence or absence ofP. ultimum. However, more biomass was produced by mycorrhizal plants whenT. aureoviride was present, whether or not soil was infested withP. ultimum. ei]R Rodriguez-Kabana     

Dialysable leukocyte extracts modify the course of experimental paracoccidioidomycosis in the Syrian hamster

The effect of dialysable leukocyte extracts (DLE) obtained from hamsters immunized withParacoccidioides brasiliensis (immune DLE) and from non-immunized hamsters (non-immune DLE) was studied in hamsters inoculated withP. brasiliensis by the intratesticular route. Treatment with immune or non-immune DLE was started during the third week of infection and was repeated at 7, 11, 15 and 19 weeks. A group of untreated infected animals was used as control. Animals were submitted to the delayed hypersensitivity skin test toP. brasiliensis antigen (PbAg) in vivo and assayed in vitro by the macrophage migration inhibition test in the presence of Phytohemagglutinin (PHA) and PbAg and by immunodiffusion for specific antibody. The animals were sacrificed at 4, 8, 12, 16 and 20 weeks. The morphology and extension of the lesions were studied at the inoculation site, and in lymph nodes, lungs, liver, spleen and kidneys. In contrast to the controls, animals treated with both DLEs maintained a positive cell-mediated immune response throughout the experiment and developed less extensive infection with a significantly lower number of fungi in the lesions. The results suggest that immune and non-immune DLE preparations modified the evolution of experimental paracoccidioidomycosis with equal efficiency. This similarity may be explained by the immunoregulatory activities of both extracts.     

Variation in heat shock proteins within tropical and desert species of poeciliid fishes

The 70-kilodalton heat shock protein (hsp70) family of molecular chaperones, which contains both stress-inducible and normally abundant constitutive members, is highly conserved across distantly related taxa. Analysis of this protein family in individuals from an outbred population of tropical topminnows, Poeciliopsis gracilis, showed that while constitutive hsp70 family members showed no variation in protein isoforms, inducibly synthesized hsp70 was polymorphic. Several species of Poeciliopsis adapted to desert environments exhibited lower levels of inducible hsp70 polymorphism than the tropical species, but constitutive forms were identical to those in P. gracilis, as they were in the confamilial species Gambusia affinis. These differences suggest that inducible and constitutive members of this family are under different evolutionary constraints and may indicate differences in their function within the cell. Also, northern desert species of Poeciliopsis synthesize a subset of the inducible hsp70 isoforms seen in tropical species. This distribution supports the theory that ancestral tropical fish migrated northward and colonized desert streams; the subsequent decrease in variation of inducible hsp70 may have been due to genetic drift or a consequence of adaptation to the desert environment. Higher levels of variability were found when the 30- kilodalton heat shock protein (hsp30) family was analyzed within different strains of two desert species of Poeciliopsis and also in wild-caught individuals of Gambusia affinis. In both cases the distribution of hsp30 isoform diversity was similar to that seen previously with allozyme polymorphisms.      

The ultrastructure of the paratympanic organ (Vitali) in Gallus domesticus: preliminary studies

The sensory epithelium of the paratypanic organ (Vitali) was studied by means of the electron microscope. Two kinds of cells are present. One type extends from the basement membrane to the surface of the epithelium; their nuclei are arranged close to the connective tissue and are surrounded by a pale cytoplasm. The distal part of these cells, which are denser and richer in organelles, possess microvilli. The cells of the second type are located above the basement membrane and are found between the upper parts of the cells of the first type. Their cytoplasm is rich in small round vesicles, free ribosomes and cisternae of rough endoplasmic reticulum are present especially in the infranuclear zone. The apical part contains a Golgi apparatus lysosomes and multive sicular bodies. At the apex each cell possesses a cuticular plate numerous stereocilia and one kinocilium. The stereocilia become increasingly longer from one side of the cell surface to the other and the kinocilium is situated on the side where the stereocilia are longest. Nervous fibers are present in the epithelium and are in close contact with the cells of the second type. The cells we have described are remarkably similar to the supporting and hair cells of the vestibular sensory epithelium.     

Methods for determining the proliferation kinetics of cells by means of 5-bromodeoxyuridine.

After treatment of cells with 5-bromodeoxyuridine (BUdR), the percentage of completely BUdR-labelled interphase nuclei is greater the longer the BUdR treatment. The labelling effect is visible after staining with the fluorochrome 33258 Hoechst and with Giemsa. Various formulae and a nomogram are presented by means of which the percentage of cells in S period, duration of the S period and the whole cell cycle can be determined by examination of a single preparation or by comparison of several preparations. The methods are tested using cell cultures of Microtus agrestis and compared with autoradiographic methods after labeling with 3H-thymidine.     

Experimental paracoccidioidomycosis in the Syrian hamster

Male hamsters (105) received intratesticular injection of suspension of a live yeast phase culture ofParacoccidioides brasiliensis and were sacrificed weekly during 20 weeks. Humoral immunity was studied by the agar-gel immunodiffusion (ID) and indirect immunofluorescence (IF) tests. Cell-mediated immunity was determined by the macrophage migration inhibition test in the presence of phytohemagglutinin (PHA) andParacoccidioides brasiliensis soluble antigen (PbAg). The morphology of the lesions was studied in the inoculation site, lymph nodes, lung, liver, spleen and kidneys.Disseminated paracoccidioidomycosis was observed in 100% of the animals after the first week. The lesions were initially made up of fungi surrounded by polymorphonuclear neutrophils and macrophages. Up to the 10th week the majority of the lesions appeared as compact confluent ephitelioid granulomas containing rare large fungi, some showing signs of degeneration. At this time, the specific antibody titers and the cellular immune response to PHA and PbAg were highest.From the 11th week on the granulomas became less compact, edematous with the epithelioid cells loosely arranged. This change was accompanied by an increase in the number of fungi showing reproductive activity and was associated with renal amyloidosis and progressive decline of cellular immune response both to PHA and PbAg. Contrariwise the titers of circulating antibodies were maintained.In the present model, disseminated paracoccidioidomycosis of the hamster was associated with depression of cellular immunity, change in the pattern of the granuloma, intense fungi proliferation and amyloidosis.     

Control of cell volume in the J774 macrophage by microtubule disassembly and cyclic AMP

We have explored the possibilities that cell volume is regulated by the status of microtubule assembly and cyclic AMP metabolism and may be coordinated with shape change. Treatment of J774.2 mouse macrophages with colchicine caused rapid microtubule disassembly and was associated with a striking increase (from 15-20 to more than 90 percent) in the proportion of cells with a large protuberance at one pole. This provided a simple experimental system in which shape changes occurred in virtually an entire cell population in suspension. Parallel changes in cell volume could then be quantified by isotope dilution techniques. We found that the shape change caused by colchicine was accompanied by a decrease in cell volume of approximately 20 percent. Nocodozole, but not lumicolchicine, caused identical changes in both cell shape and cell volume. The volume loss was not due to cell lysis nor to inhibition of pinocytosis. The mechanism of volume loss was also examined. Colchicine induced a small but reproducible increase in activity of the ouabain-sensitive Na(+), K(+)-dependent ATPase. However, inhibition of this enzyme/transport system by ouabain did not change cell volume nor did it block the colchicines-induced decrease in volume. One the other hand, SITS (4’acetamido, 4-isothiocyano 2,2’ disulfonic acid stilbene), an inhibitor of anion transport, inhibited the effects of colchicines, thus suggesting a role for an anion transport system in cell volume regulation. Because colchicine is known to activate adenylate cyclase in several systems and because cell shape changes are often induced by hormones that elevate cyclic AMP, we also examined the effects of cyclic AMP on cell volume. Agents that act to increase syclic AMP (cholera toxin, which activates adenylate cyclase; IBMX, and inhibitor of phosphodiesterase; and dibutyryl cyclic AMP) all caused a volume decrease comparable to that of colchicine. To define the effective metabolic pathway, we studied two mutants of J774.2, one deficient in adenylate cyclase and the other exhibiting markedly reduced activity of cyclic AMP-dependent protein kinase. Cholera toxin did not produce a volume change in either mutant. Cyclic AMP produced a decrease in the cyclase-deficient line comparable to that in wild type, but did not cause a volume change in the kinase- deficient line. This analysis established separate roles for cyclic AMP and colchicine. The volume decrease induced by cyclic AMP requires the action of a cyclic AMP-dependent protein kinase. Colchicine, on the other hand, induced a comparable volume change in both mutants and wild type, and thus does not require the kinase.     

Late DNA replicaion of X chromosomes in female and pseudofemale cells of Microtus agrestis.

The late replication pattern of the short arms of the X chromosomes of Microtus agrestis was studied in female cells and in cells with 2 X chromosomes of male origin by means of the BUdR-Giemsa technique and of 3H-thymidine labelling. The light absorption of Giemsa stained chromosome sections which were unifilarly substituted with BUdR (labelled), was found to be 59.2% of that of unlabelled chromosomes. In female cells, asynchrony of DNA replication of both X chromosomes indicated the presence of facultative heterochromatin in the X2 and euchromatin in the X1. In the male cells only euchromatic X chromosomes were observed in diploid XX and XO cells as well as in triploid XXY, XX and XO cells. The results show that inactivation of an X chromosone in vitro, in cells with more than one originally active X chromosome does not occur even after a culture duration of several years.